AdaControl User Guide
*********************

Last edited: November 13, 2015

   This is the AdaControl User Guide.  It describes how to install and
use AdaControl.  Please refer to the AdaControl Programmer Manual to
learn how to add new kinds of rules to AdaControl.

   AdaControl is Copyright (C) 2005-2015 Eurocontrol/Adalog, except for
some specific modules that are (C) 2006 Belgocontrol/Adalog, (C) 2006
CSEE/Adalog, (C) 2006 SAGEM/Adalog, or (C) 2015 Alstom/Adalog.
AdaControl is free software; you can redistribute it and/or modify it
under terms of the GNU General Public License as published by the Free
Software Foundation; either version 2, or (at your option) any later
version.  This unit is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General
Public License for more details.  You should have received a copy of the
GNU General Public License distributed with this program; see file
COPYING. If not, write to the Free Software Foundation, 59 Temple Place
- Suite 330, Boston, MA 02111-1307, USA.

   As a special exception, if other files instantiate generics from this
program, or if you link units from this program with other files to
produce an executable, this does not by itself cause the resulting
executable to be covered by the GNU General Public License.  This
exception does not however invalidate any other reasons why the
executable file might be covered by the GNU Public License.

   This document is Copyright (C) 2005-2015 Eurocontrol/Adalog.  This
document may be copied, in whole or in part, in any form or by any
means, as is or with alterations, provided that (1) alterations are
clearly marked as alterations and (2) this copyright notice is included
unmodified in any copy.

1 Introduction
**************

AdaControl is an Ada rules controller.  It is used to control that Ada
software meets the requirements of a number of parameterizable rules.
It is not intended to supplement checks made by the compiler, but rather
to search for particular violations of good-practice rules, or to check
that some rules are obeyed project-wide.  AdaControl can also be handy
to make statistics about certain usages of language features, or simply
to search for the occurrences of particular constructs; its scope is
therefore not limited to enforcing programming rules, although it is of
course one of its main goals.

   AdaControl is a commercial product of Adalog
(http://www.adalog.fr/adalog2.htm) with professional grade support
available.  Getting support is highly recommended for industrial
projects.  Adacontrol can also be customized or extended to match your
special needs, please refer to *note Support:: or contact Adalog at
<info@adalog.fr>.

1.1 Features
============

AdaControl analyzes a set of Ada units, according to parameterizable
controls.  Controls can be given from the command line, from a file, or
interactively.  There is a wide range of controls available.  Some are
quite simple (although very useful):
   * Control physical layout of the program (Maximum line length, no use
     of tabulations...)
   * Control occurences of special strings in comments (like TBD for "To
     Be Defined"), with full wildcarding.
   * Use of features (goto statement, tasking, pointers, variables in
     package specifications...)
   * Use of any declared entity, with full overloading resolution
   Other rules are quite sophisticated:
   * Control series of "if"..."elsif" that could be replaced by "case"
     statements
   * Verify usage of declarations (variables that should be constant,
     variables read but not written...)
   * Control declarations that could be moved to a more reduced,
     internal scope
   * Limit the call depth of a program (and diagnose recursive
     subprograms)
   * Enforce a pattern that guarantees that exceptions are not handled
     silently
   * Enforce a pattern for paired calls (like semaphore's "P" and "V")
     that guarantees that the closing call is always executed, even in
     presence of exceptions.
   * Check that there is no aliasing between out parameters
   * Ensure that no protected operation calls a potentially blocking
     operation
   and much, much more...  See *note Rules reference:: for the complete
reference for all possible controls.

   AdaControl is very simple to use.  It takes, as parameters, a list of
units to process and a list of commands that define the controls to
apply.  The complete syntax of the commands is described in chapter
*note Command language reference::.

   AdaControl produces messages to the standard output, unless
redirected.  Several levels of messages are defined (i.e.  error or
found), depending on the kind of the control (i.e.  check or search).

   Rules can be locally disabled for a part of the source code, and
various options can be passed to the program.

   Ex:

   Given the following package:
     package Pack is
        pragma Pure (Pack);
        ...
     end Pack;
   The following command:
     adactl -l "search pragmas (pure)" pack
   produces the following result (displayed to standard output):
     pack.ads:2:4: Found: PRAGMAS: use of pragma Pure

   AdaControl integrates nicely in environments such as GPS (*note
Running AdaControl from GPS::), AdaGide (*note Running AdaControl from
AdaGide::), or emacs (*note Control kinds and report messages::).  In
those environments, you can run AdaControl from menus or by just
clicking on a button!

1.2 Support
===========

1.2.1 Commercial support
------------------------

Adalog provides commercial support for AdaControl.  Support includes the
following benefits:
   * Help with installation procedures.
   * Explanations regarding the use of the tool, and help for
     translating coding standards into AdaControl rules.
   * Dedicated account into our BT system for priority handling of
     problem reports.
   * Correction of problems encountered in the use of AdaControl.
     Pre-releases versions of AdaControl are provided for each corrected
     problem.
   * Access to beta-versions before they are released
   * Keeping in sync customer's own custom rules with the latest version
     of AdaControl.
   * Reduced rate for on-demand development of custom rules.
   * Priority consideration of enhancement requests.  Satisfying
     enhancement requests is not part of the support contract; however,
     Adalog is constantly improving AdaControl, and suggestions
     originating from supported customers are given a high priority in
     our todo list.

   Adalog cannot correct problems whose origin is due to compiler bugs
or defects in the implementation of ASIS (contact your compiler provider
for support on these problems).  However, Adalog will do its best effort
to find workarounds for such problems.

   In addition, Adalog can provide various services:
   * Custom improvements to AdaControl, including application-specific
     rules;
   * consulting services for defining coding standards;
   * consulting services in all areas related to Ada, real-time,
     compilation, etc.  See Adalog's site
     (http://www.adalog.fr/adalog2.htm) for details.

   For pricing information about support contract and other services,
please contact <info@adalog.fr>.

1.2.2 Other support
-------------------

There is a Wiki for questions about AdaControl at
<https://sourceforge.net/p/adacontrol/wiki/Home/>.  This is the place to
ask for information, make suggestions, or get help from the community.

   For problem reports, please create a ticket into our BT system at
<https://sourceforge.net/p/adacontrol/tickets/>.

1.2.3 Your support to us, too!
------------------------------

If you enjoy AdaControl, there are several things you can do to help us
continue and improve this nice project.
   * Rate it, or even better post a review, on the SourceForge review
     page (http://sourceforge.net/projects/adacontrol/reviews/)
   * Click "I use it" from AdaControl's home page
     (http://www.adalog.fr/adacontrol2.htm).
   * Rate it on AdaControl's Ohloh page
     (http://www.ohloh.net/p/11353?ref=sample)
   * Get a support contract, or encourage your company, your friends, or
     anybody else to get a support contract!
   * Provide good ideas, new rules, suggestions for improvements...
   And remember: developing AdaControl is an expensive effort (according
to Ohlo's COCOMO model, it is worth 15 man.year of development).  We
need support from our users to keep it running!

1.3 History
===========

The development of AdaControl was initially funded by Eurocontrol
(<http://www.eurocontrol.int>), which needed a tool to help in verifying
the million+ lines of code that does Air Traffic Flow Management over
Europe.  Because it was felt that such a tool would benefit the
community at-large, and that further improvements made by the community
would benefit Eurocontrol, it was decided to release AdaControl as free
software.  Later, Eurocontrol, Belgocontrol, Ansaldo (formerly
CSEE-Transport), and SAGEM-DS sponsored the development of more rules.

   The requirements for AdaControl were written by Philippe Waroquiers
(Eurocontrol-Brussels), who also conducted extensive testing of
AdaControl over the Eurocontrol software.  The software was developped
by Arnaud Lecanu and Jean-Pierre Rosen (Adalog).  Rules, improvements,
etc.  were contributed by Pierre-Louis Escouflaire (Adalog), Alain
Fontaine (ABF consulting), Richard Toy (Eurocontrol-Maastricht), and
Isidro Ilasa Veloso (GMV). AdaGide support and improvement of icons were
contributed by Gautier de Montmollin.  Emmanuel Masker (Alstom) and
Yannick Duchene contributed to GPS integration.

   See file 'HISTORY' for a description of the various versions of
AdaControl, including enhancements of the current version over the
previous ones.  Users of a previous version are warned that the rules
are not 100% upward-compatible: this is necessary to make the rules more
consistent and easier to use.  However, the incompatibilities are
straightforward to fix and should affect only a very limited number of
files.  See *note Non upward-compatible changes:: for details.

1.4 References
==============

  1. "On the benefits for industrials of sponsoring free software
     development", Ada User Journal, Volume 26, number 4, december 2005

     <http://www.adalog.fr/publicat/Free-software.pdf>
  2. "A Comparison of Industrial Coding Rules", Ada User Journal, Volume
     29, number 4, december 2008

     <http://www.adalog.fr/publicat/coding-rules.pdf>
  3. "A Methodology for Avoiding Known Compiler Problems Using Static
     Analysis", proceedings of the ACM SIGAda Annual International
     Conference (SIGAda 2010)

     <http://dl.acm.org/authorize?316395>

2 Installation
**************

Like any ASIS application, AdaControl can be run only if the compiler
available on the system has exactly the same version as the one used to
compile AdaControl itself.  The executable distribution of AdaControl
will work only with GNAT version GPL 2015, as distributed by AdaCore.
If you are using any other version, please use the source distribution
of AdaControl and compile it as indicated below.

   Another reason for using the source distribution of AdaControl is
that the user may not be interested in all provided rules.  It is very
easy to remove some rules from AdaControl to increase its speed.  *Note
Customizing AdaControl::.

2.1 Building AdaControl from source
===================================

This section is only for the source distribution of AdaControl.  If you
downloaded an executable distribution (and are using the latest version
of GNAT GPL), you may skip to the next section.

2.1.1 Getting the correct version of the sources for your Gnat version
----------------------------------------------------------------------

ASIS is continuously evolving to support Ada-2005/2012 features, and so
is AdaControl.  As a consequence, the full set of features of AdaControl
is supported only with recent versions of Gnat, namely with GnatPRO
7.2.0 and GnatGPL-2013 (and higher).  We refer to these versions as the
"new Gnat", and we encourage all users to use the latest versions.

   Some user may however need to use an older version of Gnat.  We
provide also a version of AdaControl that is compatible with versions
GnatPRO 7.0.x and GnatGPL-2011 and older (before some incompatible -but
necessary- changes in ASIS happened).  We refer to these versions as the
"old Gnat".

   The release whose distribution files start with "adactl" is for the
new Gnat, and the one whose distribution files start with "adactl-old"
is for the old-gnat.  Both versions provide the same features, except
that controls related to Ada-2012 (or that depend on new features of
ASIS) are not available in the old-gnat version.  Moreover, the old-gnat
version is now frozen, and will not receive any new features or
improvements in the future, unless requested by a supported customer
(such requests will be honoured as part of the support contract).  See
*note Support:: for information on becoming a supported user.

   Note that intermediate releases of Gnat (GnatPRO-7.1.x, GnatGPL-2012)
are not fully compatible with either of these distribution.  Depending
on exact version, problems may range from compilation errors to
incorrect results in some rare (Ada 2012) cases.  Compatible sources can
be obtained from the Git repository of AdaControl on SourceForge
(<http://adacontrol.sourceforge.net>).  We will be happy to help our
supported customers who must use one of these versions.

2.1.2 Prerequisites
-------------------

The following software must be installed in order to compile AdaControl
from source:
   * A GNAT compiler, any version (but please consider *note Getting the
     correct version of the sources for your Gnat version:: above).
     Note that the compiler must also be available on the machine in
     order to run AdaControl (all ASIS application need the compiler).
   * ASIS for GNAT

   Make sure to have the same version of GNAT and ASIS. The version used
for running AdaControl must be the same as the one used to compile
AdaControl itself.

2.1.3 Build with installer (Windows)
------------------------------------

Run the installer ('adactl_src-setup.exe').  This will automatically
build and install AdaControl, no other installation is necessary.

2.1.4 Build with project file
-----------------------------

Simply go to the 'src' directory and type:
     gnatmake -Pbuild.gpr
   You're done!

   Caveat (old gnat only): Due to a bug in some versions, if you are
using GNATPro 6.1.2 and above, you must set the variable GNAT_FIX to 1;
i.e.  invoke the command as:
     gnatmake -Pbuild.gpr -XGNAT_FIX=1

2.1.5 Build with Makefile
-------------------------

The previous method may fail if Asis is not installed in an usual place.
As an alternative method, it is possible to build AdaControl with a
regular Makefile.

   The file 'Makefile' (in directory 'src') should be modified to match
the commands and paths of the target system.  The following variables
are to be set:
   * ASIS_TOP
   * ASIS_INCLUDE
   * ASIS_OBJ
   * ASIS_LIB
   * RM
   * EXT
   How to set these variables properly is documented in 'Makefile'.  See
also the compilation options in this file; a change is needed if you are
using GNATPro 6.1.2 and above.

   Then, run the make command:
     $ cd src
     $ make build

   It is also possible to delete object files and do other actions with
this "Makefile", run the following command to get more information:
     $ make help

   NOTE: Building AdaControl needs the "make" command provide with GNAT;
it works both with WIN32 shell and UNIX shell.

2.1.6 Build with a compiler other than GNAT
-------------------------------------------

It should be possible to compile AdaControl with other compilers than
GNAT, although we didn't have an opportunity to try it.  If you have
another compiler that supports ASIS, note that it may require some easy
changes in the package 'Implementation_Options' to give proper
parameters to the 'Associate' procedure of ASIS. Rules that need string
pattern matchings need the package 'Gnat.Regpat'.  If you compile
AdaControl with another compiler, you can either port 'Gnat.Regpat' to
your system, or use a (limited) portable implementation of a simple
pattern matching (package 'String_Matching_Portable').  Edit the file
'string_matching.ads' and change it as indicated in the comments.  No
other change should be necessary.

   Alternatively, if you are using another compiler, you can try and
compile your program with GNAT just to be able to run AdaControl.
However, compilers often differ in their support of representation
clauses, which can cause your program to be rejected by GNAT. In that
case, we provide a sed script to comment-out all representation clauses;
this can be sufficient to allow you to use AdaControl.  *Note
unrepr.sed::.

2.1.7 Testing AdaControl
------------------------

Testing AdaControl needs a UNIX shell, so it works only with UNIX
systems.  However, it is possible to run the tests on a WIN32 system by
using an UNIX-like shell for WIN32, such as those provided by CYGWIN or
MSYS. To run the tests, enter the following commands:
     $ cd test
     $ ./run.sh

   All tests must report PASSED. If they don't, it may be due to one of
the following issues:
   * You are using an old version of GNAT. AdaControl runs without any
     known problem (and it has been checked against the whole ACATS)
     only with the latest GNATPro and GNATGPL versions; earlier versions
     are known to have bugs and unimplemented features that will not
     allow AdaControl to run correctly in some cases.  We strongly
     recommend to always use the most recent version of GNAT.
   * You run an old-gnat version of AdaControl with GNATPro (6.1.2 and
     above) and you forgot to specify the "-XGNAT_FIX=1" option.  *Note
     Build with project file::.
   * It may happen that the test 'tfw_help' reports "FAILED" because it
     includes a check on the version of AdaControl, and the version
     string refers to Gnat-GPL2015.  The only difference (you can see it
     by typing "d" when prompted for checking the differences) should be
     the name of the compiler.

2.1.8 Customizing AdaControl
----------------------------

If there are some rules that you are not interested in, it is very easy
to remove them from AdaControl:
  1. In the 'src' directory, edit the file 'framework-plugs.adb'.  There
     is a 'with' clause for each rule (children of package 'Rules').
     Comment out the ones you don't want.
  2. Recompile 'framework-plugs.adb'.  There will be error messages
     about unknown procedure calls.  Comment out the corresponding
     lines.
  3. Compile AdaControl normally.  That's all!

   It is also possible to add new rules to AdaControl.  If your favorite
rules are not currently supported, you have several options:
  1. If you have some funding available, please contact info@adalog.fr.
     We'll be happy to make an offer to customize AdaControl to your
     needs.
  2. If you don't have funding, but have some knowledge of ASIS
     programming, you can add the rule yourself.  We have made every
     effort to make this as simple as possible.  Please refer to the
     AdaControl programmer's manual for details.  If you do so, please
     send your rules to rosen@adalog.fr, and we'll be happy to integrate
     them in the general release of AdaControl to make them available to
     everybody.
  3. If you have good ideas, but don't feel like implementing them
     yourself (nor financing them), please send a note to
     rosen@adalog.fr.  We will eventually incorporate all good
     suggestions, but we can't of course commit to any dead-line in that
     case.

2.2 Installing AdaControl
=========================

All you need to run AdaControl is the executable named 'adactl' under
Linux or 'adactl.exe' under Windows.  In addition, 'pfni' (or 'pfni.exe'
under Windows) is a convenient utility, required by the GPS support.
*Note pfni::.

   If you downloaded the Windows installer executable version of
AdaControl, simply run 'adactl_exe-setup.exe'.  This will install all
the files in the recommended locations (as has been done with the
Windows installer source version), including GPS support if you have GPS
installed and/or AdaGide support if you have AdaGide installed.

   If you built AdaControl from source without an installer, the
executables are in the 'src' directory of the distribution.  If you
downloaded an executable distribution, they are in the root directory of
the distribution.  Copy the executables to any convenient directory on
your path; a good place, for example, is in the 'bin' directory of your
GNAT installation.

2.3 Installing support for GPS
==============================

Integration of AdaControl into GPS with all functionalities requires GPS
version 4.2 or above (delivered since GNAT/GPL2008).

   To add AdaControl support to GPS, copy the file 'GPS/adacontrol.xml'
into the '<GNAT_dir>/share/gprconfig' directory; copy all other files
from the 'GPS' directory into the '<GPS_dir>/share/gps/plug-ins'
directory.  Copy also HTML files from the 'doc' directory into the
'<GPS_dir>/share/doc/gps/html' to access AdaControl's guides from the
"Help" menu of GPS.

2.4 Installing support for AdaGide
==================================

To add AdaControl support to AdaGide, copy the file 'AdaControl.tdf'
from the 'AdaGide' directory into AdaGide's root directory.  Note that
AdaControl support requires AdaGide version 7.42 or above.

3 Program Usage
***************

AdaControl is a command-line program, i.e.  it is normally called
directly from the system shell.  Options are introduced by a "-"
followed by a letter and can be grouped as usual.  Some options take the
following word on the command line as a value; such options must appear
last in a group of options.  Parameters are words on the command line
that stand by themselves.  Options and parameters can be given in any
order.

   The syntax for invoking AdaControl in regular mode is:
     adactl [-deEirsTuvwx]
            [-p <project file>]     [-f <rules file>]    [-l <rules list>]
            [-o <output file>]      [-t <trace file>]    [-F <format>]
            [-S <statistics level>] [-m <warning limit>] [-M <message limit>]
            {<unit>[+|-<unit>]|[@]<file>} [-- <ASIS options>]

   AdaControl can process Ada-2012 as well as Ada-95 programs, even if
there are currently few Ada-2012 related controls - but we hope to
improve that situation in the near future.

   If you are using Ada-2005 (or Ada-2012) features, make sure that GNAT
is set up for Ada-2005/2012 (this is the default for GNAT-GPL). Due to
technical reasons, the -gnat05 option cannot be passed to the compiler
in "compile on the fly" mode, but you can do any of the following:
   * have a "gnat.adc" file in the current directory that contains a
     'pragma Ada_05;' (or 'pragma Ada_12;')
   * put a 'pragma Ada_05' (or 'pragma Ada_12;') on top of every
     compilation unit that uses Ada-2005/2012 features;
   * generate the tree files manually (*note Generating tree files
     manually::) with the "-gnat05" (or "-gnat12)") option.  Note that
     this allows you to pass any other GNAT option as well.

   Note that if your program is pure Ada-95 and you are using a version
of GNAT where Ada-2005 is the default (especially GNAT-GPL), and in the
rare cases where your program would not compile in Ada-2005 mode
(notably if you have a function that returns a task type), you can force
Ada-95 the same way by using 'pragma Ada_95' instead.

3.1 Command line parameters and options
=======================================

3.1.1 Input units
-----------------

Units to be processed are given as parameters on the command line.  Note
that they are Ada _compilation unit_ names, not _file names_: case is
not significant, and there should be no extension!  Child units are
allowed following normal Ada naming rules: 'Parent.Child', but be aware
that specifying a child unit will automatically include its parent unit
in the analysis.  Subunits are processed during the analysis of the
including unit; there is therefore no need to specify subunits
explicitely.  If you do specify a subunit explicitly, it will result in
the whole enclosing unit being analyzed.

   However, as a convenience to the user, units can be specified as file
names, provided they follow the default GNAT naming convention.  More
precisely, if a parameter ends in ".ads" or ".adb", the unit name is
extracted from it (and all "-" in the name are substituted with ".").
File names can include a path; in this case, the path is automatically
added to the list of directories searched ("-I" ASIS option).  The file
notation is convenient to process all units in a directory, as in the
following example:
     adactl -f my_rules.aru *.adb

   In the unlikely case where you have a child unit called 'Ads' or
'Adb', use the "-u" option to force interpretation of all parameters as
unit names.

   By default, both the specification and body of the unit are
processed; however, it is possible to specify processing of the
specification only by providing the "-s" option.  If only file names are
given, the "-s" option is assumed if all files are specifications
(".ads" files).  It is not possible to specify processing of bodies
only, since rules dealing with visibility would not work.

   The "-r" option tells AdaControl to process (recursively) all user
units that the specified units depend on (including parent units if the
unit is a child unit or a subunit).  Predefined Ada units and units
belonging to the compiler's run-time library are never processed.

   Ex:
     adactl -r -f my_rules.aru my_main
   will process 'my_main' and all units that 'my_main' depends on.  If
'my_main' is the main procedure, this means that the whole program will
be processed.

   It is possible to specify more than one unit (not file) to process in
a parameter by separating the names with "+".  Conversely, it is
possible to specify units that are not to be processed, separated by
"-".  When a unit is subtracted from the unit list, it is never
processed even if it is included via the recursive option, and all its
child and separate units are also excluded.  This is convenient to avoid
processing reusable components, that are not part of a project.  For
example, if you want to run AdaControl on itself, you should use the
following command:
     adactl -f my_rules_file.aru -r adactl-asis-a4g
   This applies the rules from the file 'my_rules_files.aru' to
AdaControl itself, but not to units that are part of ASIS (units 'Asis',
'A4G', and their children) that would be found by the "-r" (recursive)
option otherwise.

   Alternatively, it is possible to provide units indirectly with a
parameter consisting of an "@" followed by the name of a file.  This
file must contain a list of unit names (not files), one on each line.
Only the first "word" of the line is considered, i.e.  everything after
the first blank is ignored.  This can be useful to annotate unit names.
All units whose names are given in the file will be processed.  If a
name in the file starts with "@", it will also be treated as an indirect
file (i.e.  the same process will be invoked recursively).  If a line in
the file starts with "#" or "--", it is ignored.  This can be useful to
temporarily disable the processing of some files or to add comments.

   Ex:
     adactl -f my_rules.aru @unit_file.txt

3.1.2 Commands
--------------

Commands specify which processing AdaControl should apply to units.  See
*note Command language reference:: for a detailed description of all
commands.

   Commands can be given directly on the command line with the "-l"
option.  A commands list must be quoted with """.

   Ex:
     adactl pack.ads proc.adb -l "check instantiations (My_Generic);"
   It is possible to pass several commands separated by ";", but as a
convenience to the user, the last ";" may be omitted.

   Commands can also be read from a file, whose name is given after the
"-f" option (the "'.aru'" extension is taken by default).  As a special
case, if the file name is "-", commands are read from the standard
input.  This is intended to allow AdaControl to be pipelined behind
something that generates commands; if you want to type commands directly
to AdaControl, the interactive mode is more appropriate.  *Note
Interactive mode::.

   Ex:
     adactl -f my_rules.aru proc.adb

   Note that the "-l" and "-f" options are not exclusive: if both are
specified, the commands to be performed include those in the file
(first) and then those given on the command line.

3.1.3 Output file
-----------------

Messages produced by controls are output to the output file; by default,
it is the standard output, but it can be changed by specifying the "-o"
option.

   Ex:
     adactl -f my_rules.aru -o my_output.txt proc.adb
   If the output file exists, new messages are appended to it.  This
allows running AdaControl under several directories that make up the
project, and gathering the results in a single file.  However, if the
"-w" option is given, AdaControl overwrites the output file if it
exists.

   All other messages, including syntax error messages, units processed
(in verbose mode), and possible internal error mesages from AdaControl
itself are output to the standard error file.

3.1.4 Output format
-------------------

The "-F" option selects the output format.  It must be followed by
"Gnat", "Gnat_Short", "CSV", "CSV_Short", "Source", "Source_Short", or
"None" (case insensitive).  By default, the output is in "Gnat" format.
See *note Control kinds and report messages:: for details.

   The "-S" option selects which statistics are output after each run.
It must be followed by a value in the range 0..3.  See *note Control
kinds and report messages:: for details on the various statistics
levels.

   The "-T" option prints a summary of timing at the end of each run.
This indicates how long (in real-time seconds) was spent in processing
each rule.

   Ex:
     adactl -F CSV -S 2 -f my_rules.aru -o my_output.csv proc.adb

3.1.5 Output limits
-------------------

The "-m" and "-M" options are used to limit the output of AdaControl.
These options are followed by an integer value that specifies the
maximum number of error messages ("-m") or warning and error messages
("-M"). If the value is omitted, a previous limitation (comming for
example from a command file) is cancelled.

   If the indicated number of messages is exceeded during a run,
AdaControl stops immediately.

3.1.6 Project files
-------------------

An emacs project file (the file with a ".adp" extension used by the Ada
mode of Emacs) can be specified with the " -p" option.  AdaControl will
automatically consider all the directories mentioned in "src_dir" lines
from the project file.

   Ex:
     adactl -f my_rules.aru -p proj.adp proc.adb

   Note that AdaControl does not accept ".gpr" project files, because
ASIS does not currently accept the "-P" option like other GNAT commands
do.  However, when run from GPS, the interface will automatically use
the source directories from the current (root) project (unless you have
explicitely set a ".adp" file in the switches *note AdaControl
switches::).

   If you have a project that uses ".gpr" project files and you want to
run AdaControl from the command line (not from GPS), you can generate a
".adp" project file from a ".gpr" project file from within GPS, by using
the "Tools/AdaControl/Generate .adp project" menu.  *Note Running
AdaControl from GPS::.  Alternatively, it is also possible to use GPS
project files by generating the tree files manually.  *note Generating
tree files manually:: for details.

3.1.7 Local disabling control
-----------------------------

The "-i" option tells AdaControl to ignore disabling markers in Ada
source code (*note Disabling controls::); i.e.  all controls will be
performed, regardless of the presence of disabling markers.  This is
equivalent to the command "'set ignore ON;'".  Note that if you you have
many messages, setting this option can speed-up AdaControl considerably.
It is therefore advisable to always set this option when you know that
there is no disabling marker in your source code.

   The "-j" option tells AdaControl to invert the meaning of disabling
markers, i.e.  only messages marked as disabled will be printed.  This
is useful to check which messages have been disabled.  This is
equivalent to the command "'set ignore INVERTED;'".

3.1.8 Verbose and debug mode
----------------------------

In the default mode, AdaControl displays only messages from triggered
controls.  It is possible to get more information with the verbose
option ("-v").  In this mode, AdaControl displays a a progress indicator
and unit names as they are processed, and its global execution time when
it finishes.  Note that the progress indicator includes an indication of
the run number if there are more than one "go" command.

   The "-d" option enables debug mode.  This mode provides more
information in case of an internal program error, and is of little
interest for the casual user.  Note that if you hit Ctrl-C in debug
mode, AdaControl aborts with a message telling the currently active rule
and module.  This can be useful if you suspect AdaControl to be stuck in
an infinite loop.

   In debug mode, AdaControl may also, in rare occasions (and only with
some versions of GNAT), display ASIS "bug boxes"; this does not mean
that something went wrong with the program, but simply that an ASIS
failure was properly recovered by AdaControl.

   Output of the messages printed by the "-d" option can be directed to
a "trace" file (instead of being printed to the standard error file).
This is done by the "-t" option, which must be followed by the file
name.  If the trace file exists, new messages are appended to it.

3.1.9 Treatment of warnings
---------------------------

The "-e" option tells AdaControl to treat warnings as errors, i.e.  to
report a return code of 1 even if only "search" controls were triggered.
*Note Return codes::.  It does not change the messages however.

   Conversely, the "-E" option tells AdaControl to not report warnings
at all, i.e.  only errors are reported.  However, if you ask for
statistics, the number of warning messages is still counted.  *Note
Control kinds and report messages::.

3.1.10 Exit on error
--------------------

If an internal error is encountered during the processing of a unit,
AdaControl will continue to process other units.  However, if the "-x"
option is given, AdaControl will stop on the first error encountered.
This option is mainly useful if you want to debug AdaControl itself (or
your own rules).  *Note In case of trouble::.

   Ex:
     adactl -x -f my_rules.aru proc.adb

3.1.11 ASIS options
-------------------

Everything that appears on the command line after "--" will be treated
as an ASIS option, as described in the ASIS user manual.

   Casual users don't need to care about ASIS options, except in one
case: if you are running AdaControl from the command line (not from
GPS), and if the units that you are processing reference other units
whose source is not in the same directory, AdaControl needs to know how
to access these units (as GNAT would).  This can be done either by using
an Emacs project file with the "-p" option (see *note Project files::),
by putting the appropriate directories into the ADA_INCLUDE_PATH
environment variable, or by passing "-I" options to ASIS.

   It is possible to pass one or several "-I" options to ASIS, to
provide other directories where sources can be found.  The syntax is the
same as the "-I" option for GNAT.

   Other ASIS options, like the "-Cx" and/or "-Fx" options, can be
specified.  Most users can ignore this feature; however, specifying
these options can improve the processing time of big projects.  *Note
Optimizing Adacontrol::.

3.2 Return codes
================

In order to ease the automation of controlling programs with shell
scripts, AdaControl returns various error codes depending on how
successful it was.  Values returned are:
   * 0: At most "search" controls (i.e.  warnings) were triggered (no
     control at all with "-e" option)
   * 1: At least one "check" control (i.e.  error) was triggered (or at
     least one "search" or "check" control with "-e" option)
   * 2: AdaControl was not run due to a syntax error in the rules or in
     the specification of units.
   * 10: There was an internal failure of AdaControl.

3.3 Environment variable and default settings
=============================================

If the environment variable "ADACTLINI" is set, its content is taken as
a set of commands (separated by semi-colons) that are executed before
any other command.  Although any command can be specified, this is
intended to allow changing default settings with "set" commands.  *Note
Set command::.

   For example, you can set ADACTLINI to "set format Gnat_Short" if you
prefer having you messages in short format rather than the (default)
long format.

3.4 Interactive mode
====================

The "-I" option tells AdaControl to operate interactively.  In this
mode, commands specified with "-l" or "-f" options are first processed,
then AdaControl prompts for commands on the terminal.  Note that the
"quit" command (*note Quit command::) is used to terminate AdaControl.

   The syntax of commands run interactively is exactly the same as the
one used for files; especially, each command must be terminated with a
";".  Note that the prompt ("Command:") becomes ".......:" when
AdaControl requires more input because a command is not completely
given, and especially if you forget the final ";".

   As with files, it is possible to give several commands on a single
line in interactive mode.  If a command contains syntax errors, all "go"
commands (*note Go command::) on the same line are temporarily disabled.
Other commands that do not have errors are normally processed however.

   The interactive mode is useful when you want to do some analysis of
your code, but don't know beforehand what you want to control.  Since
the ASIS context is open only once when the program is loaded, queries
will be much faster than running AdaControl entirely with a new query
given in a "-l" option each time.  It is also useful to experiment with
AdaControl, and to check interactively commands before putting them into
a file.

3.5 Other execution modes
=========================

In addition to normal usage, AdaControl features special options to ease
its use; no Ada unit is analyzed when using these options.

3.5.1 Getting help
------------------

The "-h" option provides help about Adacontrol usage.  If the "-h"
option is given, no other option is analyzed and no further processing
happens.

   Syntax:
     adactl -h [<keyword> | <rule name> | variables ["<pattern>"] ...]
     <keyword> ::= all | commands | license | list | options | rules | version

   The "-h" option without parameter displays a help message about usage
of the AdaControl program, the various options, and the rule names.

   Otherwise, the "-h" must be followed by one or several keywords or
rule names (case irrelevant); its effect is:
   * <rule name>: if <rule name> is exactly the name of rule, display
     the help message for the indicated rule.  Otherwise, <rule name> is
     interpreted as a pattern, and help messages for all rules that
     match the pattern is displayed.  Patterns are given using the full
     Regexp syntax.  *note Syntax of regular expressions:: for details.
   * "variables" lists the values of all variables whose name matches
     <pattern>, or all variables if there is no <pattern>.  Patterns are
     given using the full Regexp syntax.  *note Syntax of regular
     expressions:: for details.
   * "all": display the help message for all rules.
   * "commands": display a summary of all commands
   * "license": display the license information
   * "list": display the names of all rules (note that "rules" also
     displays the list of rules, in a prettier format; the "list" option
     is mainly useful for the integration of AdaControl into GPS).
   * "options": display help about the command-line options
   * "rules": display the names of all rules.
   * "version": display AdaControl and ASIS implementation version
     numbers.

   Ex:
     adactl -h pragmas Unnecessary_Use_Clause
     adactl -h all
     adactl -h version license
     adactl -h stat
   Note in the last example that "stat" is not the name of a rule; it is
therefore interpreted as a pattern, and help will be displayed for all
rules that include the string "stat" in their name.  This can be very
convenient to retrieve the name of a rule if you don't remember exactly
how it is spelled.

3.5.2 Checking commands syntax
------------------------------

The "-C" option is used to check syntax of commands without executing
any control.

   Syntax:
     adactl -C [-dv] [-f <rules file>] [-l <rules list>]

   In this mode, AdaControl simply checks the syntax of the commands
provided with the "-l" option, or of the commands provided in the file
named by the "-f" option (at least one of these options must be
provided).  No other processing will happen.

   AdaControl will exit with a return code of 0 if the syntax is
correct, and 2 if any errors are found.  A confirming message that no
errors were found is output if the "-v" option is given.

   This option is especially useful when you have modified a rules file,
before trying it on many units.  The way AdaControl works, it must open
the ASIS context (a lengthy operation) before analyzing the rules.  This
option can therefore save a lot of time if the rules file contains
errors.

3.5.3 Generating a units list
-----------------------------

The "-D" options produces a list of units that can be reused as an
indirect file in later runs.  Syntax:
     adactl -D [-rsvw] [-o <output file>] [-p <project file>]
               {<unit>[+|-<unit>]|[@]<file>} [-- <ASIS options>]
   In this mode, AdaControl outputs the list of units that would be
processed.  It is especially useful when used with the "-r" option and
given the main unit name, since it will then generate the whole list of
dependent units (hence the name "D").

   This list can be directed to a file with the "-o" option (if the file
exists, it won't be overwritten unless the "-w" option is specified).
This file can then be used in an indirect list of units.  *Note Input
units::.  Note that it is more efficient to create the list of units
once and then use the indirect file than to specify all applicable units
or use the "-r" option each time AdaControl is run.

3.6 Running AdaControl from GPS
===============================

If you want to use AdaControl from GPS, make sure you have copied the
necessary files into the required places.  *Note Installing
AdaControl::.

   AdaControl integrates nicely into GPS, making it even easier to use.
It can be launched from menu commands, and parameters can be set like
any other GPS project parameters.  When run from within GPS, AdaControl
will automatically retrieve all needed directories from the current GPS
project.

   After running AdaControl, the "locations" panel will open, and you
can retrieve the locations of errors from there, just like with a
regular compilation.  Errors will be marked in red in the source,
warning will be marked orange, and you will have corresponding marks
showing the places of errors and warnings in the speedbar.  Note that
AdaControl errors appear under the "AdaControl" category, but if there
were compilation errors, they will appear under the "Compilation"
category.  Final counts from "count" control kinds will appear under the
"Counts summary" category, and statistics under the "Statistics"
category.

3.6.1 The AdaControl menu and buttons
-------------------------------------

GPS now features an "AdaControl" menu, with several submenus:
   * "Control Current File (rules file)" runs AdaControl on the
     currently edited file, with rules taken from the current rules
     file; this menu is greyed-out if no rules file is defined, if no
     file window is currently active, or if the associated language is
     not "Ada".  The name of the rules file can be set from the
     "Library" tab from the "Project/Edit Project Properties" menu.
   * "Control Root Project (rules file)" runs AdaControl on all units
     that are part of the root project, with rules taken from the
     current rules file; this menu is greyed-out if no rules file is
     defined.  The name of the rules file can be set from the "Library"
     tab from the "Project/Edit Project Properties" menu.
   * "Control Units from List (rules file)" runs AdaControls on units
     given in a indirect file, with rules taken from the current rules
     file.  This menu is greyed-out if no rules file is defined or if no
     indirect file is defined.  The name of the rules file and of the
     indirect file can be set from the "Library" tab from the
     "Project/Edit Project Properties" menu.
   * "Control Current File (interactive)" runs AdaControl on the
     currently edited file, with a rule asked interactively from a
     pop-up; this menu is greyed-out if no file window is currently
     active, or if the associated language is not "Ada".
   * "Control Root Project (interactive)" runs AdaControl on all units
     that are part of the root project, with a rule asked interactively
     from a pop-up.
   * "Control Units from List (interactive)" runs AdaControls on units
     given in a indirect file, with a rule asked interactively from a
     pop-up.  This menu is greyed-out if no indirect file is defined.
     The name of the indirect file can be set from the "Library" tab
     from the "Project/Edit Project Properties" menu.
   * "Check Rules File" checks the syntax of the current rules file.
     This menu is deactivated if the current window does not contain an
     AdaControl rules file.
   * "Open Rules File" opens the rules file.  This menu is deactivated
     if there is no current rules file defined.
   * "Open Units File" opens the units file.  This menu is deactivated
     if there is no current units file defined.
   * "Create units file" creates a text file containing all units (not
     files) names from the current root project.  This file is
     appropriate as an indirect file for the "...  from list" commands.
   * "Create .adp project" creates an Emacs-style project file from the
     current GPS project, which can be used with the "-p" option if you
     want to run AdaControl from the command line.  This file has the
     same name as the current GPS project, with a ".adp" extension.
     *Note Project files::.
   * "Delete Tree Files" removes existing tree files from the current
     directory.  This is convenient when AdaControl complains that the
     tree files are not up-to-date.  Note that you can set the
     preferences for automatic deletion of tree files after each run
     (see below).  Note that the name of this menu is changed to "Delete
     Tree and .ali Files" if you have chosen to delete .ali files in the
     preferences (see below).
   * "Load results file" loads in the location window the result file
     obtained from a previous run of AdaControl.  The file must have
     been produced with the "Gnat" or "Gnat_Short" format.  *Note
     Control kinds and report messages::.

   There are also two buttons representing Lady Ada in a magnifier glass
in the toolbar, one with a red question mark in the background.  These
buttons launch AdaControl, by default on the file currently being
edited; however, you can change this behaviour from the preferences to
control either files from a list, or all files from the project.  The
button without the question mark uses rules from the current rules file,
while the one with the question mark asks for the control to apply
interactively.

   Here are some tips about using the "interactive" menus (or the button
with the question mark):
   * When you use the "interactive" menus several times, the previously
     entered command(s) is used as a default.
   * You can enter any command from AdaControl's language in the dialog;
     you can even enter several commands separated by ";".
   * Especially, if you want to run AdaControl with a rules file that is
     not the one defined by the switches, you can use one of the
     "interactive" commands, and give "source <file name>" as the
     command.

3.6.2 Contextual menu
---------------------

AdaControl adds two entries to the contextual menus (right click) of Ada
files.  They call the 'pfni' utility on the current entity.  *Note
pfni::.  The entry "Print full name" displays the full name of the
entity in simple form, while the entry "Print full name (with
overloading)" ) prints it with overloading information.  If the name
refers to an entity which is initialized (or to a parameter with a
default value), the initial value is printed.  If the entity is a
discrete type, its range is printed.  If the entity is an array type,
the ranges of its indices are printed.

   This is convenient to find how to name entities in rule files.  *Note
Specifying an Ada entity name::.  It is also convenient to find where an
entity is declared, and which of several overloaded entities is being
referred to.

   This is also convenient to find the actual value of a constant from
anywhere in the program text, since the printed value is completely
evaluated if it is a (static) expression.

3.6.3 AdaControl switches
-------------------------

The tab "switches" from the "Project/Edit Project Properties" menu
includes a page for AdaControl, which allows you to set various
parameters.  Since the GPS interface analyzes the output of AdaControl,
you should not set options directly in the bottom window of this page
(the one that displays the actual options passed to AdaControl).

3.6.3.1 Files
.............

This section controls the definition of various files used by
AdaControl.
   * "Rules file".  This is the name of a file that contains the
     definition of the controls to be applied to your project.  This
     file is required for all "control (rules file)" commands.
   * "Units file".  This is the name of a file that contains the list of
     units to be controlled.  This file is required for all "control
     from list" commands.
   * ".adp project file".  This is the name of an emacs project file
     (.adp).  If this name is not empty, AdaControl will use it instead
     of providing all libraries as "-I" options on the command line.
     This may be necessary if you have many libraries and the command
     line that launches AdaControl becomes too long.  Note that this
     file can be created using the "AdaControl/Create .adp project"
     menu.

3.6.3.2 Processing
..................

This section offers options that control how units are processed.
   * "Recursive mode".  This sets the "-r" option.  *Note Input units::.
   * "Ignore local deactivation".  This sets the "-i" option.  *Note
     Local disabling control::.
   * "Process specs only".  This sets the "-s" option.  *Note Input
     units::.
   * "Compilation unit mode".  This sets the "-u" option.  *Note Input
     units::.

3.6.3.3 Debug
.............

This section controls the debugging options of AdaControl.
   * "Debug messages".  This sets the "-d" option.  *Note Verbose and
     debug mode::.
   * "Halt on error".  This sets the "-x" option.  *Note Exit on
     error::.

3.6.3.4 Output
..............

This section offers options that control where and how the output of
AdaControl is displayed.
   * "Display only errors".  This sets the "-E" option.  *Note Treatment
     of warnings::.
   * "Warnings as errors".  This sets the "-e" option.  *Note Treatment
     of warnings::.
   * "Statistics".  This sets the "-S" option from a pull-down menu.
     *Note Control kinds and report messages::.
   * "Send results to GPS". When checked (default), the output of
     AdaControl is sent to the "locations" window of GPS.
   * "Send results to File".  When checked, the output of AdaControl is
     sent to the file indicated in the box below.
   * "Send results to File and GPS". When checked, the output of
     AdaControl is sent to the file indicated in the box below, and the
     content of the file is then automatically reloaded in the
     "locations" window of GPS. If this option is set, the file format
     is always "Gnat" (the file format option is ignored).
   * "File name".  This is the name of the file that will contain the
     results when sent to "File" or "File and GPS". If the results are
     sent to "File" and the file exists, AdaControl will ask for the
     permission to overwrite it.  If the results are sent to "File and
     GPS", the result file is always overriden without asking.
   * "File format".  This is a pull-down menu that allows you to select
     the desired format when output is directed to a file ("-F" option).
     *Note Control kinds and report messages::.

3.6.3.5 ASIS
............

This section controls the ASIS parameters passed to AdaControl.  The
content of the input field "ASIS options" is used in place of the
standard ("-CA -FM") one.

   Casual users don't need to change the default ASIS options.  For more
details, *note ASIS options::.

3.6.4 AdaControl preferences
----------------------------

There is an entry for AdaControl in the "edit/preferences" menu:
   * "delete trees".  If this box is checked, tree files are
     automatically deleted after each run of AdaControl.  This avoids
     having problems with out-of-date tree files, at the expanse of
     slightly slowing down AdaControl if you run it several times in a
     row without changing the source files.
   * "Delete .ali files with tree files".  If this box is checked, the
     ".ali" files in the current directory will also be deleted together
     with the tree files (either automatically if the previous box is
     checked, or when the "AdaControl/Delete Tree Files" menu is
     selected).  This is normally what you want, unless the current
     directory is also used as the object directory for compilations; in
     the latter case, deleting ".ali" files would cause a full
     recompilation for the next build of the project.
   * "Help on rule".  This allows you to select how rule specific help
     (from the "Help/AdaControl/Help on rule" menu) is displayed.  If
     you select "Pop-up", a summary of the rule's purpose and syntax is
     displayed in a pop-up.  If you select "User Guide", the user guide
     opens in a browser at the page that explains the rule.  (Caveat:
     due to a problem in GPS under Windows, the "User Guide" option may
     not work at all, or the browser will not find the right anchor;
     hopefully, this will be fixed in an upcomming release of GPS. No
     such problem under Linux).
   * "Use separate categories".  If this box is checked, there will be
     one category (i.e.  tree in the locations window) for each rule
     type or label, otherwise all messages will be grouped under the
     single category "AdaControl".  In practice, this means that with
     the box checked, messages will be sorted by rules first, then by
     files, while otherwise, the messages will be sorted by files first,
     then by rules.  In any case, compilation errors appear under the
     "Compilation" category, final counts under the "Counts summary"
     category, and statistics under the "Statistics" category.
   * "Auto save files".  If this box is checked, all modified files are
     automatically saved without asking before running AdaControl.
     Otherwise, a dialog appears allowing the user to choose which files
     to save.
   * "Buttons operate on".  This defines the behaviour of the buttons.
     If "Current File" is selected, the buttons operate on the file
     being currently edited.  If "Root Project" is selected, the buttons
     operate on all files that are part of the current project.  If
     "Units from List" is selected, the buttons operate on all units
     from the units file.
   * "Display AdaControl run".  If this box is checked, the command line
     used to launch AdaControl and the output messages are displayed in
     the "Messages" window.
   * "Max allowed error messages".  If non zero, run will stop if the
     number of error messages exceeds this limit.  *Note Output
     limits::.
   * "Max allowed messages (all kinds)".  If non zero, run will stop if
     the number of error and warning messages exceeds this limit.  *Note
     Output limits::.

3.6.5 AdaControl language
-------------------------

If you check "AdaControl" in the "Languages" tab, GPS will recognize
files with extension '.aru' as AdaControl rules files, and provide
appropriate colorization.

3.6.6 AdaControl help
---------------------

The AdaControl User Manual (this manual) and the AdaControl Programmer
Manual are available from the "Help/AdaControl" menu of GPS.

   The "Help on rule" entry displays the list of all rules; if you click
on one of them, you get help for the particular rule.  Depending on the
setting of the "Help on rule" preference (see above), it opens a pop-up
that displays the rule(s) purpose and the syntax of its parameters, or
opens the user guide at the appropriate location.

   The "About" entry displays a popup with AdaControl's version number
and license condition.

3.6.7 Caveat
------------

GPS may crash when the output of a command is too big (i.e.  hundreds of
messages with AdaControl).  If this happens, use the "preferences" menu
to limit the number of messages.

3.7 Running AdaControl from AdaGide
===================================

If you want to use AdaControl from AdaGide, make sure you have copied
the necessary file into the required place.  *Note Installing
AdaControl::.  Note that AdaGide does not have all the parameterization
facilities of sophisticated environments like GPS, but all AdaControl
options, like the name of the rules file or the output format, can
easily be changed by editing the tool description file 'AdaControl.tdf'.

   AdaGide now features several AdaControl commands from the "tool"
menu:
   * "AdaControl" runs AdaControl on the currently edited file, with
     rules taken from the file named 'verif.aru'.
   * "AdaControl recursive" works like the previous command, with the
     addition of the "-r" (recursive) option.  When used on the main
     program, it will analyze the whole set of compilation units in the
     program.
   * "AdaControl interactive" runs AdaControl on the currently edited
     file, with a rule asked interactively from a pop-up.
   * "AdaControl: delete .adt" removes existing tree files from the
     current directory.  This is convenient when AdaControl complains
     that the tree files are not up-to-date.

3.8 Helpful utilities
=====================

This section describe utilities that are handy to use in conjunction
with AdaControl.

3.8.1 pfni
----------

The convention used to refer to entities (as described in *note
Specifying an Ada entity name::) is very powerful, but it may be
difficult to spell out correctly the name of some entities, especially
when using the overloaded syntax.

   'pfni' (which stands for Print Full Name Image) can be used to get
the correct spelling for any Ada entity.  The syntax of 'pfni' is:
     pfni [-sofdq] [-p <project-file>] <unit>[:<span>]
          [-- <ASIS options>]
     <span> ::=   <line_number>
                | [<first_line>]-[<last_line>]
                | <line_number>:<column_number>
   or
     pfni -h
   If called with the "-h" option, 'pfni' prints a help message and
exits.

   Otherwise, 'pfni' prints the full name image of all identifiers
declared in the indicated unit, unless there is a "-f" (full) option, in
which case it prints the full name image of all identifiers (i.e.
including those that are used, but not declared, in the unit).  The
image is printed without overloading information, unless the "-o" option
is given.

   In addition, 'pfni' prints the initial value of variables if there is
one, the range of discrete types, and the range of the indices of array
types.

   The <unit> is given either as an Ada unit, or as a file name,
provided the extension is ".ads" or ".adb" (as in AdaControl).  If a
span is given, only identifiers within the span are printed.  In the
first form, the span includes only the indicated line; in the second
form, the span includes all lines from <first_line> to <last_line> (if
omitted, they are taken as the first and last line of the file,
respectively).  In the third form, the span includes only the place at
the specified <line_number> and <column_number>.

   Normally, the source line corresponding to the names is printed above
the names.  The "-q" (quiet) option suppresses this.

   If the "-s" option is given (or the unit is a file name with a ".ads"
extension), the specification of the unit is processed, otherwise the
body is processed.  The "-p" option specifies the name of an Emacs
project file, and the "-d" option is the debug mode, as for AdaControl
itself.  ASIS options can be passed, like for AdaControl, after a "--"
(but -FS is the default).  *Note ASIS options::.

   As a side usage of 'pfni', if you are calling a subprogram that has
several overloadings and you are not sure which one is called, use
'pfni' with the "-o" option on that line: the program will tell you the
full name and profile of the called subprogram.

3.8.2 makepat.sed
-----------------

This file (provided in the "src" directory) is a sed script that
transforms a text file into a set of correponding regular expressions.
It is useful to generate model header files.  *Note Header_Comments::.

3.8.3 unrepr.sed
----------------

This file (provided in the "src" directory) is a sed script that
comments out all representation clauses.  It is typically useful if you
use a different compiler that accepts representation clauses not
supported by GNAT.

   Typically, you would copy all your sources in a different directory,
copy "unrepr.sed" in that directory, then run:
     sed -i -f unrepr.sed *.ads *.adb
   You can now run AdaControl on the patched files.  Of course, you
won't be able to check rules related to representation clauses any
more...

   Note that the script adds "--UNREPR " to all representation clauses.
Its effect can thus easily be undone with the following commad:
     sed -i -e "s/--UNREPR //" *.ads *.adb

3.9 Optimizing Adacontrol
=========================

There are many factors that may influence dramatically the speed of
AdaControl when processing many units.  For example, on our canonical
test (same controls, same units), the extreme points for execution time
were 111s.  vs 13s.!  Unfortunately, this seems to depend on a number of
parameters that are beyond AdaControl's control, like the relative speed
of the CPU to the speed of the hard-disk, or the caching strategy of the
file system.

   This section will give some hints that may help you increase the
speed of AdaControl, but it will not change the output of the program;
you don't really need to read it if you just use AdaControl
occasionnally.  This section is concerned only with the GNAT
implementation of ASIS; other implementations work differently.

   Bear in mind that the best strategy depends heavily on how your
program is organized, and on the particular OS and hardware you are
using.  Therefore, no general rule can be given, you'll have to
experiment yourself.  Hint: if you specify the "-v" option to
AdaControl, it will print in the end the elapsed time for running the
tests; this is very helpful to make timing comparisons.

   Note: all options described in this section are ASIS options, i.e.
they must appear last on the command line, after a "--".

3.9.1 Tree files and the ASIS context
-------------------------------------

Since AdaControl is an ASIS application, it is useful to explain here
how ASIS works.  ASIS (and therefore AdaControl) works on a set of units
constituting a "context".  Any reference to an Ada entity which is not
in the context (nor automatically added, see below) will be ignored;
especially, if you specify to AdaControl the name of a unit which is not
included in the current context, the unit will simply not be processed.

   ASIS works by exploring tree files (same name as the corresponding
Ada unit, with a ".adt" extension), which are "predigested" views of the
corresponding Ada units.  By default, the tree files are generated
automatically when needed, and kept after each run, so that subsequent
runs do not have to recreate them.

   A context in ASIS-for-Gnat is a set of tree files.  Which trees are
part of the context is defined by the "-C" option:
   * -C1 Only one tree makes up the context.  The name of the tree file
     must follow the option.
   * -CN Several explicit trees make up the context.  The name of the
     tree files must follow the option.
   * -CA All available trees make up the context.  These are the tree
     files found in the current directory, and in any directory given
     with a "-T" option (which works like the "-I" option, but for tree
     files instead of source files).

   The "-F" option specifies what to do if the program tries to access
an Ada unit which is not part of the context:
   * -FT Only consider tree files, do not attempt to compile units
     on-the-fly
   * -FS Always compile units on-the-fly, ignore existing tree files
   * -FM Compile on-the-fly units for which there is no already existing
     tree file
   Note that "-FT" is the only allowed mode, and must be specified, with
the "-C1" and "-CN" options.

   The default combination used by AdaControl is "-CA -FM".

3.9.2 Generating tree files manually
------------------------------------

It is also possible to generate the tree files manually before running
AdaControl.  Although this mode of operation is less practical, it is
recommended by AdaCore for any ASIS tool that deals with many
compilation units.  Some reasons why you might want to generate the tree
files manually are:
   * Your project uses GNAT project files, but you don't want to run
     AdaControl from GPS;
   * Your project has several source directories (ASIS had problems with
     ADA_INCLUDE_PATH, until releases dated later than Sept.  1st,
     2006).  Note that an alternative solution is to specify source
     directories with the -I option;
   * It is faster to generate tree files once than to use "compile on
     the fly" mode.

   To generate tree files manually, simply recompile your project with
the "-gnatct" option.  This option can be passed to 'gnatmake' normally.
Of course, you will need all other options needed by your project (like
the "-P" option if you are using GNAT project files).

   Tree files may be copied into a different directory if you don't want
your current directory to be cluttered by them.  In this case, use the
"-T" ASIS option to indicate the directory where the tree files are
located.

   If you chose to generate the tree files manually, you may want to
specify the "-FT" ASIS option (see above) to prevent from accidental
automatic recompilation.

3.9.3 Choosing an appropriate combination of options
----------------------------------------------------

In order to optimize the use of AdaControl, it is important to remember
that reading tree files is a time-consuming operation.  On the other
hand, a single tree file contains not only information for the
corresponding unit, but also for the specifications of all units that
the given unit depends on.  Moreover, our measures showed that reading
an existing tree file may be slower than compiling the corresponding
unit on-the-fly (but once again, YMMV).

   Here are some hints to help you find the most efficient combination
of options.
   * If you want to run AdaControl on all units of your program, use the
     "-D" option to create a file containing the list of all required
     units, then use this file as an indirect file.  Using the the "-r"
     option (recursive mode) of AdaControl implies an extra pass over
     the whole program tree to determine the necessary units.
   * If you have not disabled any rule (and have many messages),
     specifying the "-i" option (ignore disabling) saves AdaControl the
     burden of checking whether rules are disabled, which can result in
     a sensible speed-up.
   * Avoid having unnecessary tree files.  All tree files in the context
     are read by ASIS, even if they are not later used.  If you don't
     want to run AdaControl on the whole project, deleting tree files
     from a previous run can save a lot of time.
   * When using an indirect file, the order in which units are given may
     influence the speed of the program.  As a rule of thumb, units that
     are closely related should appear close to each other in the file.
     A good starting point is to sort the file in alphabetical order:
     this way, child units will appear immediately after their parent.
     You can then reorder units, and measure if it has a significant
     effect on speed.
   * If you want to check a unit individually, try using the "-C1"
     option (especially if the current directory contains many tree
     files from previous runs).  Remember that you must specify the unit
     to check to AdaControl, and the tree file to ASIS. I.e., if you
     want to check the unit "Example", the command line should look
     like:
          adactl -f rules_file.aru example -- -FT -C1 example.adt
     provided the tree file already exists.
   * For each strategy, first run AdaControl with the default options
     (which will create all necessary tree files).  Compare execution
     time with the one you get with "-FT" and "-FS". This will tell you
     if compiling on-the-fly is more efficient than loading tree files,
     or not.

3.10 In case of trouble
=======================

3.10.1 Known issues
-------------------

If you are using an old version of GNAT and your project includes source
files located in several directories, the ADA_INCLUDE_PATH environment
variable may not be considered by ASIS, resulting in error messages that
tell you that the bodies of some units have not been found (and hence
have not been processed).  This problem has been fixed in GNAT dated
later than Sept.  1st, 2006.  If this happens, either provide your
source directories as "-I" options (*note ASIS options::), or generate
the tree files manually (*note Generating tree files manually::).  Note
that this problem does not happen if you are using Emacs project files
(*note Project files::), nor if you are running AdaControl from GPS.

3.10.2 AdaControl or ASIS failure
---------------------------------

Like any sophisticated piece of software, AdaControl may fail when
encountering some special case of construct.  ASIS may also fail
occasionnally; actually, we discovered several ASIS bugs during the
development of AdaControl.  These were reported to ACT, and have been
corrected in the wavefront version of GNAT - but you may be using an
earlier version.  In this case, try to upgrade to a newer version of
ASIS. If an AdaControl or ASIS problem is not yet solved, AdaControl is
designed in such a way that an occasionnal bug won't prevent you from
using it.

   If AdaControl detects an unexpected exception during the processing
of a unit (an ASIS error or an internal error), it will abandon the
unit, clean up everything, and go on processing the remaining units.
This way, an error due to a special case in a unit will not affect the
processing of other units.  AdaControl will return a Status of 10 in
this case.

   However, if it is run with the "-x" option (eXit on error), it will
stop immediately, and no further processing will happen.

   If you don't want the garbage from a failing rule to pollute your
report, you may chose to disable the rule for the unit that has a
problem.  *Note Inhibit command::.

   If you encounter a problem while using AdaControl, you are very
welcome to report it through our Mantis bug tracking system
(https://sourceforge.net/apps/mantisbt/adacontrol/my_view_page.php)
(under Windows, you can click on "Report problem" in the AdaControl
Start menu).  Please include the exact control and the unit that caused
the problem, as well as the captured output of the program (with "-dx"
option).

4 Command language reference
****************************

AdaControl is about controlling rules.  Rules are built in AdaControl;
each rule has a name, and may require parameters.  For the complete
description of each rule, *note Rules reference::.

   To run AdaControl, you need to define which rules you want to apply
to your Ada units, what are the parameters, etc.  In addition, you may
want to define various things, like the file where the results should
go, the output format, etc.

   AdaControl defines a small command language which is used to describe
how you want to process your units.  Commands can be specified either on
the command line or in a file, that we call here a rules file.  Commands
can also be given interactively; *Note Interactive mode::.

4.1 General
===========

The command language is not case-sensitive, i.e.  the case of the
keywords, rule names, and parameters is not significant.  The layout of
commands is free (i.e.  a command can extend over several lines, and
spaces are freely allowed between syntactic elements).

   Comments are allowed in and between commands.  Comments begin with a
"#" or a "--", and extend to the end of the line.

   Since wide characters are allowed in Ada programs, AdaControl accepts
wide characters in commands as well.  With GNAT, the encoding scheme is
Hex ESC encoding (see the GNAT User-Guide/Reference-Manual).  This is
the prefered method, since few people require wide characters in
programs anyway, and that keeping the default bracket encoding would not
conveniently allow brackets for regular expressions, like those used by
some rules.  *Note Syntax of regular expressions::.

   If a syntax error is encountered in a command, an appropriate error
message is output, and analysis of the rules file continues in order to
output all errors, but no analysis of user code will be performed.

4.2 Controls
============

A control command is a command that declares one (or several) controls.
A control defines how a rule is applied to Ada units.  The syntax of a
control command is as follows:
     <control_command> ::= [<label> ":"] <control> {"," <control>} ";"
     <control>   ::= <ctrl_kind> <Rule_Name> [<parameters>]
     <parameters ::= "(" [<modifiers>] <value> {"," [<modifiers>] <value>} ")"
     <ctrl_kind> ::= "check"|"search"|"count"

   If present, the label gives a name to the control(s); it will be
printed whenever each control is activated, and can be used to disable
the control(s).  *Note Disabling controls::.  If no label is present,
the rule name is printed instead.  The label must have the syntax of an
Ada identifier, or else the label must be included within double quotes
('"'), in which case it can contain any character.

   Each control consists of a <ctrl_kind> followed by a rule name, and
(optionally) parameters.  Some parameters may be preceded by modifiers
(such as "not" or "case_sensitive").  The meaning of the rule parameters
and modifiers depends on the rule.

   Here are some examples of commands:
     check unnecessary_use_clause;
     All_Imports: search pragmas (Import);
     "Why do you need that?": check entities (Unchecked_Conversion,
                                              all 'Address);

   Specifying several controls with the same label is a shorthand which
is equivalent to specifying the same label for several controls.  It is
handy when the label is long, and/or to stress that several controls are
part of the same programming rule.  For example:
     "Check why this obsolete stuff is still used":
        check entities (obsolete_unit_1),     -- Note comma here!
        check instantiations (some_obsolete_generic);

4.2.1 Control kinds and report messages
---------------------------------------

There are three control kinds: "check", "search", and "count".

   "Check" is intended to search for rules that must be obeyed in your
programs.  Normally, if a "Check" control fails, you should fix the
program.  "Search" is intended to report some situations, but you should
consider what to do on a case-by-case basis.  Roughly, use "check" when
you consider that the failure of the control is an error, and "search"
when you consider it as a warning.  AdaControl will exit with a status
of 1 if any "Check" control is triggered, and a status of 0 if only
"Search" controls were triggered (or no control was triggered at all).

   "Count" works like "Search", but instead of printing a message for
each control which is triggered, it simply counts occurrences and prints
a summary at the end of the run.  There is a separate count for each
control label (or if no label is given, the rule name is taken instead);
if you give the same label to different controls, this allows you to
accumulate the counts.

   A report message (except for the final report of "count") comprises
the following elements:
   * the file name (where the control matches)
   * the line number (where the control matches)
   * the column number (where the control matches)
   * the label (if there is one) and/or the rule name (the rule that
     matches).
   * a message (why the control matches).  A control whose kind is
     "check" will produce an error report message (i.e.  containing the
     keyword "Error") and a control whose kind is "search" will produce
     a found report message (i.e.  containing the keyword "Found").

   The formatting of the report message depends on the format option,
which can be selected with the "-F" command-line option or the "set
format" command.

   If the format is "Gnat" (the default) or "Gnat_Short", items are
separated by ':'; this is the same format as the one used by GNAT error
messages.  Editors (like Emacs or GPS) that recognize this format allow
you to go directly to the place of the message by clicking on it.  In
order to avoid too long messages, only the label appears, unless there
is none, in which case it is replaced with the rule name.

   If the format is "CSV" or "CSV_Short", items are separated by ',' and
surrounded by double quotes.  This is the "Comma Separated Values"
format, which can be read by any known spreadsheet program, except
Excel(tm) by default, which uses the semicolon and not the comma to
separate fields.  Therefore, the formats "CSVX" and "CSVX_Short" do the
same thing, but using semi-colons (';') instead of commas.  Both the
label (replaced by an empty column if there is none) and the rule name
appear.  Note that when an output file is created in one of the "CSV"
formats, a title line is issued as the first line, following normal CSV
convention.

   If the format is "Source" or "Source_Short", the offending source
line is output, and the message is output behind it, with a "!"
pointing to the exact location of the problem.

   If the format is "None", no error message is output at all.  This is
useful when only the return code of running AdaControl is desired (just
to check if a program is OK or not).  Note that this does not prevent
the output of statistics, since these are under control of the "-S"
option or the "set statistics" command.  In this case, statistics are
output in CSVX format, since asking for statistics with a "none" format
is mainly useful for analysing the statistics with a spreadsheet
program.

   With recent versions of GNAT, the file name includes the full path of
the source file.  If the "_Short" form of the format option is used, the
file name is stripped from any path.  This can make it easier to compare
the results of controlling units from various directories.  Note that
with older versions of GNAT, the file name never includes the full path,
and the "_Short" form of the format option has no effect.

   After each run (*note Go command::), statistics may be output,
depending on the statistics level which is set with the "-S" option or
the "set statistics" command.  The meaning of the various levels is as
follows:
   * 0: No statistics are output (default)
   * 1: A count of error and warning messages is output
   * 2: The rule name and label (if any) of any control not triggered
     are output
   * 3: The rule name and label (if any) of every control is output,
     together with a count of each triggering kind ("check", "search",
     "count"), or "not triggered" if the control was not triggered.

4.2.2 Parameters
----------------

Most rules accept parameters.  Parameters can be:
   * a keyword for the rule
   * a numerical value
   * a character string (often a regular expression)
   * an Ada entity name

   A numerical value is given with the syntax of an Ada integer or real
literal (underscores and exponents are allowed as in Ada).  Based
literals are supported for integer values; if somebody can justify a
need for supporting them for reals, we'll be happy to add this feature
later...

   A character string is given within double quotes """.  As usual,
quotes appearing within the string are doubled.  The tilde character
("~") can be used as a replacement delimiter, but the same character
must be used at both ends of the string.  The latter has been chosen as
a character not used by the various shells, and can be useful to pass
quoted strings from parameters on the command line (unfortunately, we
could not use the percent ("%") sign, because it plays a special role in
DOS/Windows).

   An Ada entity name is the full name (prefixed with the names of all
units that include it) of something declared in a program.  It can be
followed by overloading information, in order to uniquely identify the
Ada entity.  If an Ada entity is overloaded and no overloading
information is provided, the rule is applied to all (overloaded) Ada
entities that match the name.  Alternatively, it can be "all" followed
by a simple name, in wich case it applies to all entities with that
name.  See *note Specifying an Ada entity name:: for the full
description of the syntax.  Here are some examples of entity names:
     Ada.Text_IO.Put                      -- All Put defined in Ada.Text_IO
     Ada.Text_IO.Put{Standard.Character}  -- The Put on Character
     all Put                              -- All Put
     Standard.Integer'Image               -- The 'Image function on Integer
     all 'Image                           -- All 'Image functions

4.2.3 Multiple controls
-----------------------

Most rules can be used in more than one control (with different
parameters).  There is no difference between a single or a multiple
configuration rule use: outputs, efficiency, etc.  are the same.

   The following rules files produce an identical configuration:
     Search Pragmas (Pure, Elaborate_All);
   and
     Search Pragmas (Pure);
     Search Pragmas (Elaborate_All);

   However, the second form can be used to give different labels.
Consider:
     Search Pragmas (Pure);
     No_Elaborate: Search Pragmas (Elaborate_All);

   The messages for pragma 'Pure' will contain "PRAGMAS", while those
for 'Elaborate_All' will contain "No_Elaborate".  If a disabling comment
mentions 'pragmas', it will disable both controls, but a disabling
comment that mentions 'No_Elaborate' will disable only the second one.

4.2.4 Disabling controls
------------------------

It is possible to disable controls on parts of the source code by
placing markers in the source code.  A marker is an Ada comment, where
the comment mark ('--') is immediately followed by the special tag
"'##'" (by default).

   There are two kinds of markers: block markers and line markers.  Both
kinds specify a list of controls to disable/re-enable.  A list of
controls is a list of rule names (to disable/re-enable all controls on
the indicated rule(s)) or control labels (to disable/re-enable all
controls with that label), separated by spaces.  Alternatively, the list
of controls can be the word "all" to disable/re-enable all controls.

   In a "'--##'" line, everything appearing after another "##" tag (by
default) is ignored.  This allows the insertion of a comment explaining
why the control is disabled at that point.

   Both tags can be changed with the "set" command.  *Note Set
command::.

4.2.4.1 Block disabling
.......................

A control is disabled from a "rule off" marker that applies to it until
a "rule on" marker that applies to it.  If there is no appropriate "rule
on" marker, the control is disabled up to the end of file.

   Syntax:
     --## rule off <control_list>
     Ada code block
     --## rule on <control_list>

   Ex:
     --## rule off rule1 rule2 ## Authorized by QA ref 1234
     I := I + 1;
     Proc (I);
     --## rule on rule2

4.2.4.2 Line disabling
......................

A control is disabled only for the line where a marker that applies to
it appears.

   Syntax:
     Ada code line --## rule line off <rule_list>
   Ex:
     I := I + 1; --## rule line off rule3 rule_label_1
   Conversely, it is possible to re-enable a control for just the
current line in a block where it is disabled:

   Syntax:
     Ada code line --## rule line on <rule_list>
   Ex:
     --## rule off rule1 rule2
     ...
     I := I + 1; --## rule line on rule2

4.2.5 Limitation
----------------

Since the disabling is based on special comments, there is a conflict
with the rule "header_comments" which is based on the content of
comments.  Line disabling is not possible with this rule, and block
disabling needs special care.  *Note Header_Comments::.

4.3 Other commands
==================

In addition to controls, AdaControl recognizes a number of commands.
Although these commands are especially useful when using the interactive
mode (*note Interactive mode::), they can be used in command files as
well.

4.3.1 Go command
----------------

This command starts processing of the controls that have been specified.

   Syntax:
     go;
   Controls are not reset after a "go" command; for example, the
following program:
     search entities (pack1);
     go;
     search entities (pack2);
     go;
   will first output all usages of 'Pack1', then all usages of both
'Pack1' and 'Pack2'.  See *note Clear command:: to reset controls.

   If not in interactive mode, a "go" command is automatically added at
the end, therefore it is not required in rules files.

4.3.2 Quit command
------------------

This command terminates AdaControl.

   Syntax:
     quit;
   If given in a file, all subsequent commands will be ignored.  This
command is really useful only in interactive mode.  *Note Interactive
mode::.

4.3.3 Message command
---------------------

This command prints a message on the output file.

   Syntax:
     message "<any string>" [pause];
   The length of the message is limited to 250 characters.  If the word
"pause" (case irrelevant) is specified after the message, AdaControl
will wait for the user to press the Return key before proceeding.

   Note that the message is syntactically a string, and must therefore
be quoted (double quotes).

4.3.4 Help command
------------------

This command prints various informations about the rules and AdaControl
itself.

   Syntax:
     Help [<help_item> {,<help_item>}]
     <Help_Item> ::=<keyword> | <rule name> | variables ["<pattern>"]
     <keyword>   ::= all | commands | license | list | options | rules | version
   Without any argument, this command prints a summary of all commands
and rule names.  If given one or more keywords or rule names, it prints
the corresponding help message.  See *note Getting help:: for the
details.

4.3.5 Clear command
-------------------

This command command clears (i.e.  removes) controls that have been
previously given.

   Syntax:
     Clear all | <rule name>{,<rule name>} ;
   The command clears all controls given for the indicated rules, of for
all rules if the 'all' keyword is given.  Rule variables (*note Set
command::) associated to cleared rules are returned to their default
values.  For example, the following program:
     search entities (pack1);
     go;
     clear all;
     search entities (pack2);
     go;
   will first output all usages of 'Pack1', then all usages of 'Pack2'.
Without the "clear all" command, the second "go" would output all usages
of 'Pack1' together with all usages of 'Pack2'.

4.3.6 Set command
-----------------

This command sets various parameters of AdaControl.

   Syntax:
     set Format Gnat|Gnat_Short|CSV|CSV_Short|Source|Source_short|None;
     set Check_Key|Search_Key "<value>"
     set Max_Errors [<value>];
     set Max_Messages [<value>];
     set Output|New_Output <output file>;
     set Statistics <level>;
     set Tag1|Tag2 "<value>";
     set Trace <trace file>;
     set Debug|Exit_On_Error|Verbose|Warning|Warning_As_Error
           On|Off;
     set Timing On|Off|Global
     set Ignore On|Off|Inverted;
     set <Rule_Name>.<Variable> <Value>
   The "set format" command selects the output format for the messages,
like the "-F" option; see *note Control kinds and report messages:: for
details.

   The "set check_key" command defines a string which is used in place
of "Error" in messages issued by a "check" control.  Similarly, the "set
search_key" command defines a string which is used in place of "Found"
in messages issued by a "search" control.  This can be useful when
AdaControl is used, for example, to detect places where manual
inspection is required; having the word "Error" in the message could be
misleading to the persons in charge of the review.  Note however that if
you set these keys, the GPS interface will not be able to recognize
properly the messages.

   The "set max_errors" and "set max_messages" limit the output of
AdaControl, like the "-m" and "-M" options; see *note Output limits::
for details.  If no <value> is given after the command name, the
corresponding limitation is removed.

   The "set output" and "set new_output" commands redirect the output of
subsequent controls to the indicated file.  If the string 'console'
(case irrelevant) is given as the <output file>, output is redirected to
the console.

   The "set new_output" always create a new file (or overwrites an
existing file with the same name).

   The "set output" command appends if the file exists, unless the "-w"
option is given, in which case it is overwritten.  However, the file is
overwritten only the first time it is mentionned in an "output" command.
This means that you can switch forth and back between two output files,
all results from the same run will be kept.  Note however that for this
to work, you need to specify the output file exactly the same way: if
you specify it once as "result.txt", and then as "./result.txt", the
second one will overwrite the first one.

   The "set statistics" command sets the statistics level, like the "-S"
option; see *note Control kinds and report messages:: for details.

   The "set Tag1|Tag2" command changes the tags used to disable (or
enable) rules.  "Tag1" is the string that appears immediately after the
comment indicator ('--'), and "tag2" is the tag that terminates the
special comment.  Note that these tags must be given as strings (in
quotes) and that case is relevant.  See *note Disabling controls:: for
details.

   The "set trace" command redirects the trace messages of the "-d"
option to the indicated file.  If the string 'console' (case irrelevant)
is given as the <trace file>, trace messages are redirected to the
console.  As with the "-t" option, if the file exists, output is
appended to it.

   The "set Debug|Exit_On_Error|Verbose|Warning|Warning_As_Error"
command activates ("on") or deactivates ("off") options.  "Debug"
corresponds to the "-d" option, "Exit_On_Error" to the "-x" option,
"Ignore" to the "-i" option, "Timing" to the "-T" option, "Verbose" to
the "-v" option, "Warning" to the "-E" option, and "Warning_As_Error" to
the "-e" option.  See *note Verbose and debug mode::, *note Exit on
error::, *note Treatment of warnings::, *note Output format::, and *note
Local disabling control:: for details.

   The "set Timing" command activates ("on") or deactivates ("off") the
printing of the time spent in each rule after each "go" command.  If set
to "global" instead of "on", the timings are accumulated over all "go"
commands, and output when the program terminates.

   The "set Ignore" command governs handling of disabled messages (*note
Disabling controls::).  In default mode ("set Ignore Off"), disabled
messages are not printed.  When set to "on" ("set Ignore On"), all
messages are printed, including those that are disabled.  Setting this
option can result in considerable speed-up of the printing of messages.
When set to "Inverted" ("set Ignore Inverted"), only disabled messages
are printed.  This is useful to check which messages have been disabled.

   Some rules may also have user-settable global variables that affect
their behaviour; the last form of the "set" command allows changing
their value.  The variable name is of the form of a qualified name (i.e.
"rule.var"), and the value depends on the variable.  The description of
the variables (if any) and appropriate values is given for each rule.

4.3.7 Source command
--------------------

This command inputs commands from another file.

   Syntax:
     Source <input file>;
   Commands are read and executed from the indicated file, then control
is returned to the place after the "source" command.  There is no
restriction on the content of the sourced file; especially, it may
itself include other "source" commands.

   If <input file> is a relative file path, it is taken relatively to
the file where the "source" command is given.  Especially, if no path is
specified, the sourced file will be taken from the same directory as the
sourcing file (irrespectively of where the command is being run from).
If the file is not found there, it is searched on the path given by the
environment variable 'ADACTL_PATH'.

   The default extension is '.aru', i.e.  if <input file> is not found
as given, AdaControl will retry the same name with '.aru' appended.  It
is a syntax error if the file is not found either.

   If the string 'console' (case irrelevant) is given as the <input
file>, commands are read from the console until a "quit" command is
given.  This command is of course useful only from files, and allows to
pass temporarily control to the user in interactive mode.

4.3.8 Inhibit command
---------------------

This command prevents execution of certain controls on particular units.

   Syntax:
     Inhibit <rule name>|all ([all] <unit> {,[all] <unit>});
   Controls refering to the given rule (or all rules if "all" is
specified in place of a rule name) for the indicated unit(s) are not
performed.  In addition, if "all" is specified in front of the unit
name, the unit will not be accessed at all, even from rules that follow
call graphs, and could thus access this unit while analyzing other
units.

   There are several reasons why you might want to inhibit a control of
a rule for certain units:
   * The unit is known not to obey the rule in many places, and you
     don't want the output to be cluttered with too many messages (of
     course, you'll fix the unit in the near future!);
   * The unit is known to obey the rule, execution of the rule is
     time-consuming, and you want to save some processing time;
   * The unit is known to raise an ASIS bug, and until you upgrade to
     the appropriate version of GNAT, you don't want to be bothered by
     the error messages.

   The "all" option for a unit is intended for the last case, to prevent
ASIS bugs from spoiling any unit that calls something from an offending
unit.

4.4 Example of commands
=======================

Below is an example of a file with multiple commands:
     message "Searching Unchecked_Conversion";
     search entitities (ada.unchecked_conversion);
     set output uc_usage.txt;
     go;
     clear all;
     message "Searching 'Address";
     search entities (all 'Address);
     set output address_usage.txt;
     go;
   This file will output all usages of 'Ada.Unchecked_Conversion' into
the file 'uc_usage.txt', then output all usages of the ''Address'
attribute into the file 'address_usage.txt'.  Messages are output to
tell the user about what's happenning.

5 Rules reference
*****************

This chapter describes each rule currently provided by AdaControl.  Note
that the 'rules' directory of the distribution contains a file named
'verif.aru' that contains an example of a set of rules appropriate to
check on almost any software.

   A general limitation applies to all rules.  AdaControl is a static
checking tool, and therefore cannot check usages that depend on run-time
values.  For example, it is not possible to check rules applying to an
entity when this entity is aliased and accessed through an access value,
or rules applying to subprogram calls when the call is a dispatching
call.

5.1 Abnormal_Function_Return
============================

This rule controls functions that may not terminate normally, i.e.
where 'Program_Error' could be raised due to reaching the end of the
function without encountering a 'return' statement.

5.1.1 Syntax
------------

     <control_kind> abnormal_function_return;

5.1.2 Action
------------

The rule controls that the sequence of statements of each function body,
as well as each of its exception handlers, ends with:
   * a 'return' statement (including extended return statements)
   * a 'raise' statement (or equivalently, a call to
     'Ada.Exceptions.Raise_Exception' or
     'Ada.Exceptions.Reraise_Occurrence');
   * a call to a procedure which is the target of a 'pragma No_Return';
   * a block statement, whose last statement of its sequence and any
     exception handler is one of these;
   * an 'if' statement that includes an 'else' path, and where the last
     statement of every path is one of these;
   * a 'case' statement where the last statement of every path is one of
     these.

   This is a sufficient (but of course not necessary) condition to
ensure that no function raises 'Program_Error' due to reaching the end
of its statements without encountering a 'return'.

   This rule can be specified only once.

   Ex:
     check abnormal_function_return;

5.1.3 Tips
----------

This rule checks that a function always returns correctly, but does not
prevent multiple 'return' statements in functions.  If you want to
ensure that there is exactly one 'return' statement in functions, and
that this statement is always the last one, use this rule together with
the rule 'statements(function_return)'.  *Note Statements::.

   It is possible to exit from an extended return statement with an
'exit' or 'goto' statement.  If this happens, the return statement is
not considered a proper return statement, and an appropriate message is
issued.

5.2 Allocators
==============

This rule controls the use of allocators (i.e.  dynamic memory
allocation).

5.2.1 Syntax
------------

     <control_kind> allocators [(<target> {, <target>})];
     <target>   ::= [anonymous | inconsistent | not] [<category>|<entity>]
     <category> ::= ()  | access    | array | delta  | digits |
                    mod | protected | range | record | tagged | task

5.2.2 Action
------------

If one or several <entity> or <category> are given, only allocators
whose allocated type matches the <entity>, or whose type belongs to the
indicated <category>, are controlled; otherwise all allocators are
controlled.  As usual, the whole syntax for entities is allowed for
<entity>.  *Note Specifying an Ada entity name::.  The meaning of
<category> is:
   * "()": The allocated value is of an enumerated type.
   * "access": The allocated value is of an access type.
   * "array": The allocated value is of an array type.
   * "delta": The allocated value is of a fixed point type (it is not
     currently possible to distinguish ordinary fixed point types from
     decimal fixed point types).
   * "digits": The allocated value is of a floating point type.
   * "mod": The allocated value is of a modular type.
   * "protected": The allocated value is of a protected type.
   * "range": The allocated value is of a signed integer type.
   * "record": The allocated value is of an (untagged) record type.
   * "tagged": The allocated value is of a tagged type (including type
     extensions).
   * "task": The allocated value is of a task type.

   This rule is especially useful for finding memory leaks, since it
tells all the places where dynamic allocation occurs.

   If a parameter is preceded by the word "not", allocators for the
corresponding type or category are not controlled (i.e.  they are always
allowed).  If a control includes only "not" parameters, an implicit
check for all allocators is assumed.

   If a parameter is preceded by the word "anonymous", only allocators
whose expected type is an anonymous access type are controlled.

   If a parameter is preceded by the word "inconsistent", only
allocators whose allocator subtype (the name after "'new'") is not the
same as the designated subtype (from the access type declaration) are
controlled.  However an allocator is not considered inconsistent when
the designated subtype imposes no special constraint:
   * when it is a class-wide type, since the allocator subtype will
     generally be of some descendant specific type;
   * when it is an unconstrained array type, since the allocated subtype
     is necessarily constrained;
   * when it is a base type (of the form 'T'Base').

   Note that if the access type includes a constraint like in the
following example:
        type Acc is access integer range 1..10;
   all allocators will necessarilly be inconsistent, since there is no
way to repeat the constraint at the place of the allocator.

   "Inconsistent" can be given alone, in which case all inconsistent
allocators are controlled.

   Ex:
     search allocators (standard.string);
     check allocators (T'Class);
     check allocators (array);
     check allocators (Inconsistent standard.Integer);
     check allocators (Inconsistent);

      -- all task allocators, except when the type is called "special":
     check allocators (task, not all Special);

5.2.3 Tips
----------

The type given as an <entity> in the rule must be a first named subtype,
and the rule will also find allocators that use a subtype of this type.
If the type is declared within a generic package, the rule will control
all corresponding types from instantiations.

   The type mentionned in the rule is the one following the 'new'
keyword, which is not necessarily the same as the expected type in
presence of implicit conversions like this:

        type T is tagged ...;
        type Class_Access is access T'Class;
        X : Class_Access;
     begin
        X := new T;

   This allocator will be found for type 'T', not for type 'T'Class'.

   For <categories>, note that the rule "sees through" derived and
private types (i.e.  it will trigger if the ultimate type belongs to the
indicated category).

   The reason for the "inconsistent" modifier is that inconsistent
allocators may cost a double check.  Given:
        type Acc is access Positive;
        V : Acc;
     begin
        V := new Natural'(...);
   The compiler will first check the constraint for Natural, then the
constraint for Positive.  To avoid confusion, it is better to always use
the same subtype for the allocator as used in the access type
declaration.

   The reason for the "anonymous" modifier is that allocators of an
anonymous type (especially access parameters) create a terrible mess in
accessibility rules, and are better avoided.

5.2.4 Limitations
-----------------

In some (rare) cases involving anonymous access types as array or record
components, ASIS provides no way to determine the target type of the
(anonymous) acccess type.  Inconsistent allocators will thus not be
controlled.  Such cases are detected by the rule "uncheckable".  *Note
Uncheckable::.

5.3 Array_Declarations
======================

This rule controls properties of arrays, by enforcing a consistent value
or range of values for the lower or upper bound, or by limiting the
possible size.  It can also control various aspects of the component
type of the array.

5.3.1 Syntax
------------

     <control_kind> array_declarations (first,      <value> | <bounds>);
     <control_kind> array_declarations (last,       <value> | <bounds>);
     <control_kind> array_declarations (dimensions, <value> | <bounds>);
     <control_kind> array_declarations (length,     <bounds>);
     <control_kind> array_declarations (component,  <type> {,<repr_cond>});
     <control_kind> array_declarations (index,      <type> | <> {,<type> | <>});
     <bounds>    ::= min|max <value> [, min|max <value> ]
     <type>      ::= <entity>|<category>
     <category > ::= () | access    | array | delta  | digits | mod | private
                        | protected | range | record | tagged | task
     <repr_cond> ::= [not] pack | size | component_size

5.3.2 Action
------------

The first parameter is a subrule keyword:
   * "First" and "Last" control the lower (respectively upper) bound of
     each dimension of arrays (even unconstrained array types).  If a
     single value is specified without the "min" or "max" modifiers, the
     subrule controls the bounds that are not exactly this value;
     otherwise, it controls the bounds that are smaller than the given
     "min" value or greater than the given "max" value.  It is possible,
     but not required to specify both "min" and "max".  If this subrule
     is given both for "search" and for "check", the value(s) for
     "search" is interpreted as the prefered one, and the value(s) for
     "check" is interpreted as an alternative acceptable one; i.e., it
     is a warning if the value is the one given for "check", and an
     error if it is neither.  In short:
          search array_declarations (first, 1);
          check array_declarations (first, min -1, max 1);
     will be silent if the lower bound of an array is 1, it will issue a
     warning if it is in the range -1 ..  1, and an error otherwise.
   * "Dimensions"controls the number of dimensions of arrays.  If a
     single value is specified without the "min" or "max" modifiers, the
     subrule controls arrays whose number of dimensions is not exactly
     this value; otherwise, it controls arrays whose number of
     dimensions are smaller than the given "min" value or greater than
     the given "max" value.  It is possible, but not required to specify
     both "min" and "max".  If this subrule is given both for "search"
     and for "check", the value(s) for "search" is interpreted as the
     prefered one, and the value(s) for "check" is interpreted as an
     alternative acceptable one; i.e., it is a warning if the value is
     the one given for "check", and an error if it is neither.  In
     short:
          search array_declarations (Dimensions, 1);
          check array_declarations (Dimensions, min 2, max 3);
     will be silent for one-dimensional arrays, it will issue a warning
     for 2- and 3-dimensional arrays, and an error otherwise.
   * "Length" controls arrays that have a dimension whose number of
     elements is smaller than the given "min" value or greater than the
     given "max" value (except for unconstrained array types).  At least
     one of "min" or "max" must be specified, but it is not required to
     specify both.
   * "Component" controls arrays whose component type is the indicated
     <entity>, or whose component type belongs to the indicated
     <category>.  If the <entity> is a subtype, only arrays whose
     components are of that subtype are controlled.  If the indicated
     <entity> is a type, all arrays whose components are of that type
     (including subtypes) are controlled.  The meaning of <category> is:
        * "()": The component is of an enumerated type.
        * "access": The component is of an access type.
        * "array": The component is of an array type.
        * "delta": The component is of a fixed point type (it is not
          currently possible to distinguish ordinary fixed point types
          from decimal fixed point types).
        * "digits": The component is of a floating point type.
        * "mod": The component is of a modular type.
        * "private": The component is of a private type (including
          private extensions).
        * "protected": The component is of a protected type.
        * "range": The component is of a signed integer type.
        * "record": The component is of an (untagged) record type.
        * "tagged": The component is of a tagged type (including type
          extensions).
        * "task": The component is of a task type.
     If <repr_cond> are specified, the rule controls only arrays to
     which all the corresponding representation items apply:
        * "pack": A pragma Pack applies to the array.
        * "not pack": No pragma Pack applies to the array.
        * "size": A size representation clause applies to the array.
        * "not size": No size representation clause applies to the
          array.
        * "component_size": A component_size representation clause
          applies to the array.
        * "not component_size": No component_size representation clause
          applies to the array.

   * "index" controls arrays whose index types are the indicated
     <entity>, or whose index types belong to the indicated <category>.
     If the <entity> is a subtype, only arrays whose indexes are of that
     subtype are controlled.  If the indicated <entity> is a type, all
     arrays whose indexes are of that type (including subtypes) are
     controlled.  The meaning of <category> is the same as for
     "component", but obviously only "()", "range", and "mod" are
     allowed.

     The number of <entity> given determines the dimensionality of the
     controlled arrays.  If a "<>" is given in place of an entity, it
     means that any type matches at that position.

   This rule can be specified several times for the "component" and
"index" subrules.  For other subrules, it can be specified at most once
for each subrule and for each of "check", "search" and "count".  It is
thus possible for each subrule to have a value considered a warning, and
a value considered an error.

   Ex:
     -- All arrays should start at 1:
     check array_declarations (first, 1);

     -- No arrray of more than 100 elements:
     check array_declarations (length, max 100);

     -- No empty array:
     check array_declarations (length, min 1);

     -- Arrays whose component type is private:
     check array_declarations (component, private);

     -- Packed arrays of Character
     check array_declarations (component, Standard.Character, pack);

     -- Packed arrays of record without size clause
     check array_declarations (component, record, packed, not size);

     -- One-dimensional arrays indexed by Integer
     check array_declarations (index, standard.integer);

     -- Three dimensional arrays whose second index is an enumeration
     check array_declarations (index, <>, (), <>);

5.3.3 Tips
----------

The subrule 'Max_Length' ignores index constraints that are not static.
Non static index constraints can be controlled with the rule 'Non_Static
(Index_Constraint)'.  *Note Non_Static::.

   Requiring the same upper bound for all arrays is not very useful,
but:
     check array_declarations (last, min 1);
   can be used to check that no array has a negative or zero upper
bound.

   The subrule "index" controls a precise pattern of types used as
indices.  To control the use of a type as an index at any position and
irrespectively of the number of indices of the array, use the rule
"type_usage".  *Note Type_Usage::.

5.4 Aspects
===========

This rule controls aspect specifications (new feature in Ada 2012),
either all of them or specific ones.

5.4.1 Syntax
------------

     <control_kind> aspects [(all | <aspect mark> {, <aspect mark>})];

5.4.2 Action
------------

Without parameters (or if "all" is given), controls all aspect
specifications.  Otherwise, controls only the aspect specifications
corresponding to the given aspect marks.

   Ex:
     search aspects;
     DBC: check aspects (Pre, Post, Pre'Class, Post'Class);

5.5 Assignments
===============

This rule controls various issues related to the assignment statement:
assignments that involve array sliding, redundant assignments to the
same variable, or groups of assignments that are replaceable by
aggregate assignment.

5.5.1 Syntax
------------

     <control_kind> assignments (sliding);
     <control_kind> assignments (repeated);
     <control_kind> assignments (groupable, <filter> {,<filter>});
     <filter> ::= given <min_val> | missing <max_val> | ratio <min_val> |
                  total <max_val>

5.5.2 Action
------------

The first form (keyword "sliding") controls array assignments where the
target variable has a different lower bound than the assigned
expression; this is allowed by the language only in so-called "sliding"
contexts.

   Other subrules control properties of groups of assignment statements.
A group is made of consecutive assignments, without any other
intervening kind of statements (except null statements).

   The second form (keyword "repeated") controls when a same variable
(or a same subcomponent of a structured variable) is assigned several
times in the same group of assignments.  This form of the rule can be
given only once.

   The third form (keyword "groupable") controls assignments to
different subcomponents of a same structured variable; such assignments
are often replaceable by a global assignment of an aggregate to the
variable.  One or several <filter> parameters indicate under which
conditions a group is reported:
   * "given": <min_val> (an integer value) indicates the minimum number
     of assigned subcomponents that will trigger the rule (i.e.  the
     rule is triggered if the number of assignments to subcomponents of
     a same variable is greater or equal to the indicated value).
   * "missing": <max_val> (an integer value) indicates the maximum
     number of subcomponents not assigned that will trigger the rule
     (i.e.  the rule is triggered if the number of subcomponents not
     assigned to is lesser or equal to the indicated value).
   * "ratio": <min_val> (an integer value) indicates the minimum
     percentage of assigned subcomponents that will trigger the rule
     (i.e.  the rule is triggered if the percentage of assigned
     subcomponents is greater or equal to the indicated value).
   * "total": <max_val> (an integer value) indicates the maximum number
     of subcomponents of the type that will trigger the rule (i.e.  the
     rule is triggered if the number of subcomponents of the record type
     is lesser or equal to the indicated value).

   If several filters are given, the rule is triggered if all conditions
are met ("and" logic).  Note however that this rule can be given several
times, thus achieving "or" logic.

   The rule is not triggered on an object if a subcomponent of that
object is of a limited type, since global assignment would not be
allowed in that case.

   For other structured objects, a subcomponent is counted as assigned
if it has been assigned in full, or if it should have been assigned in
full (in other words: if the rule is triggered on those subcomponents as
well) - recursively, of course.

   Ex:
     search Assignments (sliding);
     check  Assignments (repeated);

     -- Warn if a at least 3 fields are given and at most
     -- two fields are missing, or if 80% of the fields are given:
     search assignments (groupable, given 3, missing 2);
     search assignments (groupable, ratio 80);

5.5.3 Tip
---------

The "sliding" subrule is not intended to prevent all cases of slidings
(the dynamic ones are uncheckable), it is rather an indication of
"obvious" cases that could be avoided.

   Note that for the "groupable" subrule, it is possible to give 1 for
the "given" criterion; in this case, any assignment to parts of a
structured variable will be reported, only global assignment is allowed.

5.5.4 Limitations
-----------------

As usual, AdaControl can control only static aspects of assignments.
Therefore, it cannot control assignments whose target is not statically
known (like dynamic indexing of arrays).  Slices are always considered
dynamic (the cases where it would be useful did not seem worth the
additional complexity).

   For the "sliding" subrule, if the assigned expression is a
multidimensional aggregate, only the first dimension is checked for
sliding, other dimensions are ignored.  This is not considered an
important issue, since in any case the rule can detect only static
cases, and the handling of sliding in multi-dimensional array aggregates
is extremely touchy (see RM 4.3.3 for details).

   For the "groupable" subrule, if the number of subcomponents is not
statically determinable (dynamic arrays, discriminated records), only
the "given" criterion can be met.

5.6 Barrier_Expressions
=======================

Although the language allows any expression as the barrier of a
protected entry, it is generally better to use only "simple"
expressions.  This rule controls the kind of constructs allowed in
barrier expressions.

5.6.1 Syntax
------------

     <control_kind> Barrier_Expressions ([<allowable> {, <allowable>}]);
     <allowable>    ::= <entity> | <keyword>
     <keyword> ::= allocation          | any_component   | any_variable        |
                   arithmetic_operator | array_aggregate | comparison_operator |
                   conversion          | dereference     | indexing            |
                   function_attribute  | local_function  | logical_operator    |
                   record_aggregate    | value_attribute

5.6.2 Action
------------

Without parameters, the only elements allowed in barriers are references
to boolean components of the protected element and litterals (this
corresponds to what is allowed for the Ravenscar profile).  Parameters
specify other constructs that are allowed:
   * Any <entity> (like a global variable, a function...)  can be
     specified and is thus allowed.  As usual, the whole syntax for
     entities is allowed for <entity>.  *Note Specifying an Ada entity
     name::.
   * "allocation" allows use of allocators.
   * "any_component" allows use of protected components that are not of
     type 'Standard.Boolean'.
   * "any_variable" allows use of any variable (i.e.  variables external
     to the protected element).
   * "arithmetic_operator" allows use of predefined arithmetic operators
     ('"+"', '"**"', etc.).
   * "array_aggregate" allows use of array aggregates.
   * "comparison_operator" allows use of predefined comparison and
     membership operators ('"="', '">"', 'in', etc.).
   * "conversion" allows use of type conversions and type
     qualifications.
   * "dereference" allows use of dereferencing of access types (both
     implicit and explicit dereferences).
   * "indexing" allows use of array indexing and slices.
   * "function_attribute" allows use of attributes that are functions
     (like ''Pred', ''Image', etc.).
   * "local_function" allows use of (protected) functions declared in
     the same protected object.
   * "logical_operator" allows use of predefined logical operators and
     short-circuit forms ('and', 'or else', etc.).
   * "record_aggregate" allows use of record aggregates and extension
     aggregates.
   * "value_attribute" allows use of attributes that are simple values
     (like ''First', ''Terminated', etc.).

   This rule can be given only once for each of "check", "search" and
"count".

   Ex:
     search barrier_expressions;
     check  barrier_expressions (logical_operator, comparison_operator,
                                 any_component,
                                 Pack.Global_State);

5.6.3 Tips
----------

The goal of the "Simple_Barrier" restriction from the Ravenscar profile
is to ensure that evaluation of barriers never raise exceptions.  Even
simple things like a qualified expression can raise exceptions, but in
practice more than the restriction of the Ravenscar profile can be
"reasonably" allowed.

   Note that the various "operator" keywords allow only the use of
predefined operators.  If a user defined operator should be allowed,
provide it explicitely as an <entity>.  There is no way to allow any
function call, since this would boil down to allowing pretty much
anything, but you can of course specify explicitely functions that can
be called.

   You can provide this rule both for "check" and "search", but of
course it makes sense only if the set of allowed features for "search"
is a superset of those allowed for "check".  This way, the use of
certain features can be interpreted only as a warning.

5.7 Case_Statement
==================

This rule controls various metrics related to the 'case' statement.  It
is intended for cases where it is desired to limit the complexity of
'case' statements.

5.7.1 Syntax
------------

     <control_kind> Case_Statement (<subrule>, <bound> [, <bound>]);
     <subrule> ::= others_span | paths | range_span | values | values_if_others
     <bound>   ::= min | max <value>

5.7.2 Action
------------

The first parameter is a subrule keyword.  The second (and optionnally
third) parameter give the minimum and/or maximum allowed values (i.e.
the rule will control values outside the indicated interval).  If not
specified, the minimum value is defaulted to 0 and the maximum value to
infinity.  The parameters controlled by each subrule are:
   * "others_span" controls the number of values covered by 'when'
     'others' case alternatives.
   * "paths" controls the number of paths (i.e.  'when' branches).
   * "range_span" controls the number of values covered by ranges used
     as choices.
   * "values" controls the number of values covered by the subtype of
     the 'case' selector.
   * "values_if_others" is like "values", but is activated only for
     'case' statements with a 'when' 'others' alternative.

   This rule can be specified at most once for each subrule and for each
of "check", "search" and "count".  It is thus possible for each subrule
to have a value considered a warning, and a value considered an error.

   Ex:
     check  Case_Statement (others_span, min 1);
     search Case_Statement (others_span, min 5);

     check  Case_Statement (values, max 10);
     check  Case_Statement (paths, min 3, max 30);

5.7.3 Tips
----------

To control that no range is used as a choice in a 'case' statement:
     check case_statement (range_span, max 0);

   To control "'when' 'others'" that cover no value at all:
     check case_statement (others_span, min 1);

5.7.4 Limitations
-----------------

If some characteristic of the 'case' statement depend on a generic
formal type, it is not possible to control some of the features
statically.  Such cases are detected by the rule "uncheckable".  *Note
Uncheckable::.

5.8 Characters
==============

This rule makes sure that the program text does not use "undesirable"
characters.

5.8.1 Syntax
------------

     <control_kind> characters [(<subrule> {, <subrule>})];
     <subrule> ::= control | not_iso_646 | trailing_space | wide

5.8.2 Action
------------

The rule controls the occurrence in the source file of characters
belonging to the classe(s) defined by the subrules.  Without parameters,
all classes are controlled.  The classes are defined as follows:
   * "control": control characters that are allowed by the language
     (ASCII HT, ASCII VT and ASCII FF).
   * "not_iso_646": characters outside the ISO-646 set (aka ASCII).
   * "trailing_space": space characters appearing at the end of the
     source line.
   * "wide": wide characters that are not in 'Standard.Character'.

   This rule can be given only once for each class of characters.

   Ex:
     check characters (control, trailing_space);
     search characters (not_iso_646);

5.8.3 Limitations
-----------------

With the "wide" subrule, the error message may seem to not always appear
at the right place; this depends on the encoding scheme used.  For
example, if your source contains (using bracket encoding):
     S : Wide_String := "["1041"]["1042"]";
   it will appear to AdaControl as a string containing two characters,
and therefore the error message for the second wide character will point
at two characters after the opening quote of the string.

   This rule controls only the characters in the source file; other
means of having characters in the corresponding classes (like using the
''Val' attribute) are not controlled.

5.9 Comments
============

This rule controls comments that must, or must not, appear in certain
cases.

5.9.1 Syntax
------------

     <control_kind> comments (pattern, "<pattern>" {, "<pattern>"});
     <control_kind> comments (position, <value> | <bounds>);
     <control_kind> comments (terminating {, "<pattern>" | begin | end});
     <control_kind> comments (unnamed_begin, <kind> {, <kind>});
     <bounds>    ::= min|max <value> [, min|max <value> ]
     <kind>      ::= [<condition>] <unit_kind>
     <condition> ::= always | declaration | program_unit
     <unit_kind> ::= all | procedure | function | entry | package | task

5.9.2 Action
------------

The first parameter is a subrule name which detemines what is being
controlled.
   * "pattern" controls comments that match one of the given patterns
     (given as strings).  Only the "useful" part of the comment is
     matched against the patterns, i.e.  the part after the "'--'" and
     spaces following it.  Patterns are given using the full Regexp
     syntax.  *note Syntax of regular expressions:: for details.
     Pattern matching is always case insensitive.

     This subrule is especially useful to find lines with comments like
     "TBSL" (To Be Supplied Later) or "fixme", which are often used to
     mark places where something should be done before releasing the
     program.
   * "position" controls the starting position of comments.  If a single
     value is specified without the "min" or "max" modifiers, the
     subrule controls comments that do not start exactly at the
     indicated column position; otherwise, it controls comments whose
     starting column is smaller than the given "min" value or greater
     than the given "max" value.  It is possible, but not required to
     specify both "min" and "max".  If this subrule is given both for
     "search" and for "check", the value(s) for "search" is interpreted
     as the prefered one, and the value(s) for "check" is interpreted as
     an alternative acceptable one; i.e., it is a warning if the value
     is the one given for "check", and an error if it is neither.  In
     short:
          search comments (position, 1);
          check  comments (first, min 1, max 6);
     will be silent for comments that start in column 1, it will issue a
     warning for comments that start at columns 2 to 6, and an error
     otherwise.

   * "terminating" controls comments that are at the end of an otherwise
     non empty line (i.e.  that appear on the same line as a declaration
     or statement).  If "begin" is specified, comments appearing on a
     line that contains only a 'begin' are allowed (not reported);
     similarly, if "end" is specified, comments appearing on a line that
     contains only an 'end' are allowed.  Otherwise, the other
     parameters are patterns that specify forms of comments that are
     allowed.  Patterns are given using the full Regexp syntax.  *note
     Syntax of regular expressions:: for details.  Pattern matching is
     always case insensitive.
   * "unnamed_begin" controls 'begin' of various constructs that do not
     have a comment that repeats the name of the program unit associated
     to the 'begin'.  Except for spaces, the comment must not contain
     anything else than the unit name.

     The <condition> keyword determines circumstances where the comment
     is required:
        * "always" (default): the comment is always required.
        * "declaration": the comment is required only if the preceding
          declaration part is non-empty (not counting pragmas).
        * "program_unit": the comment is required only if the preceding
          declaration part contains the declarations of other program
          units (subprograms, packages, protected objects, or tasks).

     The <unit_kind> keyword detemines the kind of program unit to which
     the rule applies ("all" stands for all kinds).  The subrule can be
     given only once of each kind of program unit.

   Ex:
     check comments (pattern, "TBSL");

     -- Report places where rules are disabled:
     search comments (pattern, "##.* off");

     -- End of line comments are not allowed, except for the
     -- comment that repeats the name of a procedure on the "begin"
     -- line, and special AdaControl comments
     check comments (terminating, begin, "^ *##");

     -- Named begin required for packages unless they have no
     -- declaration, and subprograms if they have nested units
     check comments (unnamed_begin, declaration package);
     check comments (unnamed_begin, program_unit procedure);
     check comments (unnamed_begin, program_unit function);

5.9.3 Tips
----------

Remember that a Regexp matches if the pattern matches any part of the
identifier.  Use "^" and "$" to match the beginning (resp.  end) of the
comment, or both.

5.9.4 Limitations
-----------------

This rule does not support wide characters outside the basic Latin-1
set.

5.10 Declarations
=================

This rule controls usage of various kinds of declarations, possibly only
those occurring at specified locations.

5.10.1 Syntax
-------------

     <control_kind> declarations (<subrule> {, <subrule>});
     <subrule>     ::= {[not] <location_kw>} <declaration_kw>
     <location_kw> ::= all | block   | library | local      | nested |
                       own | private | public  | in_generic | task_body
     <declaration_kw> ::=
        any_declaration                   | abstract_function                 |
        abstract_operator                 | abstract_procedure                |
        abstract_type                     | access_all_type                   |
        access_constant_type              | access_constrained_array_type     |
        access_def_discriminated_type     | access_formal_Type                |
        access_language_type              | access_nondef_discriminated_type  |
        access_protected_type             | access_subprogram_type            |
        access_task_type                  | access_unconstrained_array_type   |
        access_unknown_discriminated_type | access_type                       |
        aliased_array_component           | aliased_constant                  |
        aliased_protected_component       | aliased_record_component          |
        aliased_variable                  | anonymous_access_component        |
        anonymous_access_constant         | anonymous_access_discriminant     |
        anonymous_access_parameter        | anonymous_access_variable         |
        anonymous_subtype_allocator       | anonymous_subtype_case            |
        anonymous_subtype_declaration     | anonymous_subtype_for             |
        anonymous_subtype_indexing        | array                             |
        array_type                        | binary_modular_type               |
        box_defaulted_formal_function     | box_defaulted_formal_procedure    |
        character_literal                 | child_unit                        |
        class_wide_constant               | class_wide_variable               |
        constant                          | constrained_array_constant        |
        constrained_array_type            | constrained_array_variable        |
        controlled_type                   | decimal_fixed_type                |
        defaulted_discriminant            | defaulted_generic_parameter       |
        defaulted_parameter               | deferred_constant                 |
        derived_type                      | discriminant                      |
        empty_private_part                | empty_visible_part                |
        enumeration_type                  | entry                             |
        equality_operator                 | exception                         |
        expression_function               | extension                         |
        fixed_type                        | float_type                        |
        formal_function                   | formal_package                    |
        formal_procedure                  | formal_type                       |
        function                          | function_call_renaming            |
        function_instantiation            | generic                           |
        generic_function                  | generic_package                   |
        generic_procedure                 | handlers                          |
        incomplete_type                   | in_out_generic_parameter          |
        in_out_parameter                  | initialized_protected_component   |
        initialized_record_component      | initialized_variable              |
        instantiation                     | integer_type                      |
        interface_type                    | library_unit_renaming             |
        limited_private_type              | modular_type                      |
        multiple_names                    | multiple_protected_entries        |
        name_defaulted_formal_function    | name_defaulted_formal_procedure   |
        named_number                      | non_binary_modular_type           |
        non_identical_operator_renaming   | non_identical_renaming            |
        non_joint_ce_ne_handler           | non_limited_private_type          |
        non_ravenscar_task                | not_operator_renaming             |
        null_defaulted_formal_procedure   | null_extension                    |
        null_ordinary_record_type         | null_procedure                    |
        null_procedure_body               | null_procedure_declaration        |
        null_tagged_type                  | operator                          |
        operator_renaming                 | ordinary_fixed_type               |
        ordinary_fixed_type_no_small      | ordinary_fixed_type_with_small    |
        ordinary_record_type              | ordinary_record_variable          |
        out_parameter                     | package                           |
        package_instantiation             | package_statements                |
        predefined_operator               | private_extension                 |
        procedure                         | procedure_instantiation           |
        protected                         | protected_discriminant            |
        protected_entry                   | protected_type                    |
        protected_variable                | record_type                       |
        renaming                          | renaming_as_body                  |
        renaming_as_declaration           | scalar_variable                   |
        self_calling_function             | self_calling_procedure            |
        separate                          | signed_type                       |
        single_array                      | single_protected                  |
        single_task                       | subtype                           |
        tagged_private_type               | tagged_type                       |
        tagged_variable                   | task                              |
        task_discriminant                 | task_entry                        |
        task_type                         | task_variable                     |
        type                              | unconstrained_array_constant      |
        unconstrained_array_type          | unconstrained_array_variable      |
        unconstrained_subtype             | uninitialized_protected_component |
        uninitialized_record_component    | uninitialized_variable            |
        unknown_discriminant              | variable                          |
        variant_part

5.10.2 Action
-------------

The <location_kw> restricts the places where the occurrence of the
declaration is controlled.  If it is preceded by "not", the declaration
is controlled except at this location.  Several <location_kw> can be
given, in which case the declaration is controlled at places where all
the keywords apply.  If there is no <location_kw>, it is assumed to be
"all".
   * 'all': puts no special restriction to the location.  This keyword
     can be specified for readability purposes, and if specified must
     appear alone (not with other <location_kw>), and "not" is not
     allowed.
   * 'block': only declarations appearing in block statements are
     controlled.
   * 'library': only library level declarations are controlled.
   * 'local': only local declarations are controlled (i.e.  only
     declarations appearing in (generic) packages, possibly nested, are
     allowed).
   * 'own': only declarations that are local to a (generic) package body
     are controlled.
   * 'public': only declarations appearing in the visible part of
     (generic) packages are controlled.
   * 'private': only declarations appearing directly in a private part
     are controlled.
   * 'in_generic': only declarations appearing directly or indirectly in
     a generic specification or body are controlled.
   * 'task_body': only declarations appearing directly in a task body
     are controlled.  Note that it would not make sense to have a
     <location_kw> for task specifications, since only entries can
     appear there, and they cannot appear anywhere else.

   The <declaration_kw> specifies what kind of declaration to control:
   * Declaration keywords that are Ada keywords match the corresponding
     Ada declarations.
   * 'any_declaration' controls all declarations.  This is of course not
     intended to forbid all declarations in a program (!), but
     _counting_ all declarations can be quite useful.
   * 'abstract_function', 'abstract_operator', and 'abstract_procedure'
     control the declarations of abstract functions, abstract operators,
     and abstract procedures, respectively.
   * 'abstract_type' controls the declaration of non-formal abstract
     types.
   * 'access_type' controls all access type declarations, while
     'access_subprogram_type', 'access_protected_type', and
     'access_task_type' control only access to procedures or functions,
     access to protected types, or access to task types, respectively.
     Similarly, 'access_constrained_array_type' and
     'access_unconstrained_array_type' control access to constrained or
     unconstrained array types, 'access_def_discriminated_type',
     'access_nondef_discriminated_type', and
     'access_unknown_discriminated_type' control access to types with
     discriminants with default values, without default values, and
     unknown discriminants, respectively.  'access_formal_type' controls
     access to (generic) formal types, 'access_all_type' control
     generalized access to variables types (aka "'access all T'", and
     'access_constant_type' control generalized access to constants
     types (aka "'access constant T'").  'access_language_type' controls
     access to language defined private types.
   * 'aliased_variable' and 'aliased_constant' control the declarations
     of aliased variables or constants, respectively.
   * 'aliased_array_component' controls the declaration of arrays (array
     types or single arrays) whose components are declared aliased.
   * 'aliased_record_component' and 'aliased_protected_component'
     control the declarations of aliased record (respectively protected)
     components.
   * 'anonymous_access_component' controls array and record components
     that are of an anonymous access type (but not discriminants, which
     are controlled by 'anonymous_access_discriminant').  Similarly,
     'anonymous_access_constant' and 'anonymous_access_variable' control
     constants and variables that are of an anonymous access type
     (including generic formal 'in' and 'in out' parameters,
     respectively).  'anonymous_access_parameter' controls subprogram
     parameters that are of an anonymous access type, the only ones that
     existed in Ada 95.  Note that to avoid unnecessary messages, if a
     subprogram has an explicit specification, the message for
     'anonymous_access_parameter' is given on the specification and not
     repeated on the body.
   * 'anonymous_subtype_declaration' controls the declarations of
     anonymous subtypes and ranges that are part of some other
     declaration.  Similarly, 'anonymous_subtype_allocator',
     'anonymous_subtype_case', 'anonymous_subtype_for', and
     'anonymous_subtype_indexing' control anonymous subtype declarations
     and ranges that are part of allocators, 'case' statements (ranges
     in the 'when' path), 'for' loop statements, and indexing of slices
     or array aggregates, respectively.
   * 'array' controls all array definitions (array types and single
     arrays), while 'array_type' controls only array types and
     'single_array' controls only single arrays (objects of an anonymous
     array type).  'constrained_array_type' controls only constrained
     array types, while 'unconstrained_array_type' controls only
     unconstrained array types.  'constrained_array_variable' controls
     variable declarations where the given (or anonymous) array type is
     constrained, while 'unconstrained_array variable' controls variable
     declarations where the given (or anonymous) array type is
     unconstrained (and the constraint is provided by the initial
     value).  'constrained_array_constant' and
     'unconstrained_array_constant' do the same with constants instead
     of variables.
   * 'character_literal' controls the declaration of new character
     literals, i.e.  character literals defined as part of the values of
     an enumeration type.
   * 'child_unit' controls the declaration of all child units.
   * 'constant' controls all constants, while 'class_wide_constant'
     control the declaration of constants of a class-wide type, and
     'deferred_constant' controls the declaration of deferred constants.
   * 'controlled_type' controls the declaration of controlled types,
     i.e.  descendants of 'Ada.Finalization.Controlled' or
     'Ada.Finalization.Limited_Controlled'.  Note that this includes
     also private types that are not visibly controlled.
   * 'defaulted_parameter' controls subprogram or entry (in) parameters
     that provide a default value, while 'defaulted_generic_parameter'
     controls generic formal objects that provide a default value.
   * 'derived_type' controls regular derived types, but not type
     extensions (derivations of tagged types).  These are controlled by
     'extension' and 'private_extension'.
   * 'discriminant' controls all declarations of types with
     discriminants, while 'protected_discriminant' and
     'task_discriminant' control only discriminants of protected types
     and task types, respectively.  'defaulted_discriminants' controls
     only discriminants where default values are provided.
     'unknown_discriminants' controls only unknown discriminants (AKA
     "'(<>)'" discriminants).
   * 'empty_private_part' controls package specification with an empty
     private part, i.e.  where the word 'private' appears, but the
     private part contains no declaration (even if it contains pragmas).
   * 'empty_visible_part' controls package specifications that contain
     no declaration in the visible part (before the word 'private' if
     any), even if it contains pragmas.
   * 'enumeration_type' controls the declaration of enumeration types.
   * 'exception' controls exception declarations.
   * 'expression_function' controls declaration of expression functions
   * 'fixed_type' controls all declarations of fixed point types while
     'ordinary_fixed_type' controls only ordinary (binary) fixed point
     types, 'ordinary_fixed_type_no_small' controls ordinary fixed point
     type without a representation clause for ''SMALL',
     'ordinary_fixed_type_with_small' controls ordinary fixed point type
     with an explicit representation clause for ''SMALL', and
     'decimal_fixed_type' controls only decimal fixed point types (those
     can never have a representation clause for ''SMALL').
   * 'float_type' controls declarations of floating point types.
   * 'formal_function', 'formal_package', 'formal_procedure', and
     'formal_type' control all generic formal functions, packages,
     procedures, and types, respectively.
     'box_defaulted_formal_function', 'box_defaulted_formal_procedure',
     'name_defaulted_formal_function',
     'name_defaulted_formal_procedure', and
     'null_defaulted_formal_procedure' control generic formal functions
     and procedures with a box default, a name default, and a null
     default, respectively.
   * 'generic_function', 'generic_package', 'generic_procedure' control
     generic function (respectively package, procedure) declarations.
   * 'handlers' controls the presence of exception handlers in any
     handled sequence of statements.
   * 'in_out_parameter' and 'out_parameter' control subprogram and entry
     parameters of modes 'in' 'out' and 'out' (respectively), while
     'in_out_generic_parameter' and 'out_generic_parameter' do the same
     for generic formal parameters.  Note that to avoid unnecessary
     messages, if a subprogram has an explicit specification, the
     message is given on the specification and not repeated on the body.
   * 'incomplete_type' controls incomplete type declaration.
   * 'initialized_variable' controls variable declarations that include
     an initialization expression, unless they are of a class-wide type
     since initialization is required in that case.
   * 'instantiation' controls all instantiations, while
     'function_instantiation', 'package_instantiation',
     'procedure_instantiation' control function (respectively package,
     procedure) instantiations.
   * 'integer_type' controls all declarations of integer types, while
     'signed_type' controls only signed integer types, and
     'modular_type' controls only modular types (both kinds);
     'binary_modular_type' controls only modular types whose modulus is
     a power of 2, and 'non_binary_modular_type' controls only modular
     types whose modulus is not a power of 2.
   * 'initialized_record_component' and
     'initialized_protected_component' control the declaration of record
     (respectively protected) component that include a default
     initialization, while 'uninitialized_record_component' and
     'uninitialized_protected_component' control the declaration of
     record (respectively protected) component that do not include a
     default initialization, unless they are of a limited type since
     initialization would not be allowed in that case.
   * 'limited_private_type' controls limited private type declarations,
     while 'non_limited_private_type' controls regular (non limited)
     private type declarations.  'tagged_private_type' controls tagged
     private type declarations.
   * 'multiple_names' controls declarations where more than one defining
     identifier is given in the same declaration.
   * 'multiple_protected_entries' controls protected definitions (from
     protected types or single protected objects) that have more than
     one entry declaration.  Note that a protected definition with a
     single entry family declaration is counted as a single entry
     declaration.
   * 'named_number' controls declarations of named numbers, i.e.
     untyped constants.
   * 'non_joint_CE_NE_handler' controls exception handlers whose choices
     include 'Constraint_Error' or 'Numeric_Error', but not both.  This
     is intended for legacy Ada 83 code that required to always handle
     these exceptions together; it makes little sense for Ada95 or
     Ada2005 code (and to be honnest, this subrule is provided because
     Gnatcheck has it).
   * 'null_extension' controls record extensions (derived tagged types)
     that contain no new elements.  Similarly,
     'null_ordinary_record_type' and 'null_tagged_type' control ordinary
     records and tagged types that contain no elements.  Note that the
     record definitions may be plain "'null' 'record'" definitions, or
     full record definitions that contain only null components.
     However, a definition is not considered null if it contains a
     variant part.
   * 'null_procedure_body' controls procedure declarations whose
     sequence of statements contain only 'null' statements (or blocks
     without declarations and containing only 'null' statements).
     'null_procedure_declaration' controls Ada2005 null procedure
     declarations (i.e., "procedure P is null;").  'null_procedure'
     controls both.
   * 'operator' controls the definition of operators (things like
     '"+"'); note that the message is given on the specification if
     there is an explicit specification, on the body otherwise.
     'equality_operator' controls only equality operators ('"="' and
     '"/="') and 'predefined_operator' controls only operator
     definitions that overload a predefined operator (like '"+"' on a
     numeric type, for example).
   * 'package_statements' controls the presence of elaboration
     statements in the bodies of packages (or generic packages).
   * 'private_extension' controls private extensions, i.e.  derivations
     from a tagged type with a 'with private' extension part.
   * 'record_type' controls all record type declarations (tagged or
     not), while 'ordinary_record_type' controls only non-tagged record
     types, and 'tagged_type' controls only tagged record types.
   * 'interface_type' controls interface type declarations.
   * 'renaming' controls all renaming declarations, while
     'renaming_as_body' controls only those that are renamings as bodies
     of subprograms, 'renaming_as_declaration' controls only those that
     are regular renamings of subprograms (i.e.  not as bodies),
     'operator_renaming' controls only those that are renamings of an
     operator, 'not_operator_renaming' controls only those that are
     _not_ renamings of an operator, 'function_call_renaming' controls
     renaming of the result of a function call, and
     'library_unit_renaming' controls renaming of library units.
     'non_identical_renaming' controls only renamings where the new name
     and the old name are not the same, and
     'non_identical_operator_renaming' does the same, but only for
     renamings of operators.
   * 'self_calling_function' controls functions whose body contains only
     a single (simple) 'return' statement, and the return expression is
     a (recursive) call to the same function.  Similarly,
     'self_calling_procedure' controls procedures whose body contains
     only a single statement which is a (recursive) call to the same
     procedure.  Note that this corresponds to bodies automatically
     generated by gnatstub.
   * 'subtype' controls all explicit subtype declarations (i.e.  not all
     anonymous subtypes that appear at various places in the language),
     while 'unconstrained_subtype' controls only the subtype
     declarations that do not include a constraint.
   * 'task' controls task type declarations as well as single tasks
     declarations while 'single_task' and 'task_type' control only
     single task declarations or task type declarations respectively
     (and similarly for 'protected').  'non_ravenscar_task' controls all
     task type and task object declarations from a unit to which no
     'pragma Profile (Ravenscar)' applies.
   * 'type' controls all type (but not subtype) declarations.
   * 'uninitialized_variable' controls variable declarations that do not
     include an initialization expression.  Depending on the value of
     the rule variable "limited_initialization" (see below), variables
     of a limited type, or only variables of a task or protected type,
     are not reported, since initialization would not be allowed in that
     case.
   * 'variable' controls all variable declarations.  'scalar_variable'
     controls the declarations of variables of a scalar type (integer,
     enumeration, float, fixed).  'ordinary_record_variable' controls
     declarations of variables of an untagged record type.
     'tagged_variable' controls declarations of variables of a tagged
     type (including class-wide ones), while 'class_wide_variable'
     controls only the declarations of variables of a class-wide type.
     'task_variable' and 'protected_variable' control task and protected
     objects (respectively), whether given with a named or anonymous
     type.
   * 'variant_part' controls variant parts in record defintions.

   Ex:
     -- No task, no exception:
     search declarations (task, exception);

     -- Don't declare subprograms or packages inside a block:
     check declarations (block procedure, block function, block package);

     -- No task in the public part of a package:
     check declarations (public task);

     -- Generics allowed only as top-level units
     check declarations (not library generic);

5.10.3 Variable
---------------

The rule provides a variable that allows to adjust the handling of
limited types for the subrule "uninitialized_variable".  Initialization
of variables of a limited time was not permitted until Ada 2005.

Variable           Values  Default Effect
Limited_Initializationoff/onoff    if "off", uninitialized variables of a
                                   limited type are never reported; if
                                   "on", they are reported like
                                   non-limited variables, unless they are
                                   of a task or protected type, since no
                                   initialization would be allowed in
                                   that case.

5.10.4 Tips
-----------

Certain keywords are not exclusive, and it may be the case that several
keywords apply to the same declaration; in this case, they are all
reported.  For example, if you specify:
     check declarations (record_type, tagged_type);
   tagged types will be reported both as "record_type" and
"tagged_type".

   There is no subrule for checking functions whose result type is from
an anonymous access type; these are controlled by the rule 'return_type
(anonymous_access)'.  *Note Return_Type::.

   Some of the keyword do not seem very useful; it would be strange to
have a programming rule that prevents all type declarations...  But bear
in mind that the <location_kw> can be used to restrict the check to
certain locations; moreover, AdaControl can be used not only for
checking, but also for searching; finding all type declarations in a set
of units can make sense.  As another example, "search declarations (own
variable);" will find all variables declared directly in package bodies.

   Some modifiers do not make sense with certain declarations; for
example, a "private out_parameter" is impossible (a parameter occurs in
a subprogram declaration, not directly in a private part).  This is not
a problem as far as the rule is concerned, but don't expect to find
any...

   Generally, discriminants are considered components of record types.
However, discriminants of an anonymous access type (so-called access
discriminants) play such a special role in the language that they
deserved their own control ('anonymous_access_discriminant').

   Private types are normally followed in determining the kind of access
type (i.e., an access to a private type will be controlled according to
the full declaration).  However, this is not done for an access type
that designates a private type defined in a language defined unit (since
the full type depends on the implementation); these are controlled as
"access_language_type" instead.  Of course, language defined visible
types are controlled normally.

5.10.5 Limitation
-----------------

In some rare cases, AdaControl may not be able to evaluate the modulus
of a modular type definition, thus preventing correct operation of
"binary_modular_type" and "non_binary_modular_type" subrules.  Such
cases are detected by the rule "uncheckable".  *Note Uncheckable::.

5.11 Default_Parameter
======================

This rule checks usage (or non-usage) of defaulted parameters.

5.11.1 Syntax
-------------

     <control_kind> default_parameter (<place>, <formal>, <usage>);
     <place>  ::= <entity> | calls | instantiations
     <formal> ::= <formal name> | all
     <usage>  ::= used | positional | not_used

5.11.2 Action
-------------

The rule controls subprogram calls or generic instantiations that use
the default value for the indicated parameter, or conversely don't use
it, either in positional notation or in any notation.  If a subprogram
is called, or a generic instantiated, whose name matches <entity>, and
it has a formal whose name is <formal name>, then:
   * If the string 'used' (case irrelevant) is given as the third
     parameter, the rule reports when there is no corresponding actual
     parameter (i.e.  the default value is used for the parameter).
   * If the string 'positional' (case irrelevant) is given as the third
     parameter, the rule reports when there is an explicit corresponding
     actual parameter (i.e.  the default is not used for the parameter),
     and the actual uses positional (not named) notation.
   * If the string 'not_used' (case irrelevant) is given as the third
     parameter, the rule reports when there is an explicit corresponding
     actual parameter (i.e.  the default is not used for the parameter),
     independently of whether it uses positional or named notation.

   As usual, the whole syntax for entities is allowed for <entity>.
*Note Specifying an Ada entity name::.  On the other hand, <formal> is
the simple name of the formal parameter.

   Alternatively, the <entity> can be specified as 'calls', to control
all calls or 'instantiations', to control all instantiations.  The
<formal name> can be replaced by 'all', in which case all formals are
controlled.

   Ex:
     check default_parameter (P, X, used);
     check default_parameter (P, Y, not used);
     search default_parameter (calls, all, positional);

5.11.3 Tip
----------

If the <entity> is a generic subprogram, it is also possible to give a
formal parameter (a parameter of the subprogram, not a generic
parameter) as the <formal name>; in this case, all instantiations of the
indicated generic subprogram will be controlled for the use of the
indicated parameter.

5.12 Dependencies
=================

This rule controls dependencies of units (i.e.  'with' clauses, parents,
child units...), either according to a set of allowed/forbidden units,
or by count.

5.12.1 Syntax
-------------

     <control_kind> dependencies (others, <unit> {,<unit>});
     <control_kind> dependencies (with, <unit> {,<unit>});
     <control_kind> dependencies (public_child | private_child);
     <control_kind> dependencies (<counter>, <bound> [, <bound>]);
     <counter> ::= raw | direct | parent
     <bound>   ::= min | max <value>

5.12.2 Action
-------------

The kind of action depends on the specified subrule.

   The "others" subrule controls semantic dependencies to units other
than those indicated.  This subrule can be specified only once, and at
least one unit must be given.

   The "with" subrule controls with clauses that reference the indicated
units.  At least one unit must be given.

   Note that for these two rules, renamings are followed: if you give
the basic name of a unit, it will be identified even if used with other
names.  Similarly, if you give the name of a generic, all of its
instantiations will also be controlled.

   "public_child" and "private_child" control units that depend on their
own public (respectively private) child units.  Since these subrules
have no parameters, they can be given only once.

   Other subrules control that the number of various dependencies is
whithin a specified range.  The second (and optionnally third) parameter
give the minimum and/or maximum allowed values (i.e.  the rule will
control values outside the indicated interval).  If not specified, the
minimum value is defaulted to 0 and the maximum value to infinity.
   * "raw" controls the number of units textually given in 'with'
     clauses.  Redundant 'with' clauses are counted, and a child unit
     counts for one.
   * "direct" controls the number of different units that this unit
     really depends on: if a unit is mentionned in several 'with'
     clauses, it is counted only once, but if a child unit is
     mentionned, all parents of this child unit are added to the count.
   * "parent" counts the number of parents of the current unit.  A root
     unit has no parent, a child of a root unit has one parent, etc.

   Ex:
     check dependencies (others, Ada.Text_IO);
     check dependencies (raw, max 15);

     -- child units should not be nested more than 5 levels:
     check dependencies (parent, max 5);

     -- units that depend on nothing:
     search dependencies (direct, min 1);

     -- units that depend on their public children:
     check dependencies (public_child);

5.12.3 Tips
-----------

If you give a name that's already a renaming to the "others" or "with"
subrules, the rule will only apply to this name, not to what has been
renamed.  Therefore:
      -- Allow only Ada.Text_IO:
     check dependencies (others, Ada.Text_IO);

     -- But not if the plain name Text_IO is used:
     check dependencies (with, Text_IO);

   The notion of public or private for the rules "public_child" or
"private_child" refer to the real unit, which is not necessarily the
name used in the with clause, if for example you have a private library
renaming of a public unit.

   There is a slight overlap between this rule and the rule "entities'.
But "entities" will find all uses of an entity (not necessarily a
compilation unit), while "dependencies" will control occurrences only of
compilation units, and only in 'with' clauses.  *Note Entities::.

   In certain contexts, only a set of the Ada predefined units is
allowed.  For example, it can be useful to forbid units defined in
special needs annexes.  The 'rules' directory of Adacontrol contains
files with "Dependencies" rules that forbid the use of various
predefined Ada units.  Comment out the lines for the units that you want
to allow.  You can then simply "source" these files from your own rule
file (or copy the content) if you want to disallow these units.  *Note
Rules files provided with AdaControl::.

5.13 Directly_Accessed_Globals
==============================

This rule checks that global variables in package bodies are accessed
only through dedicated subprograms.  Especially, it can be used to
prevent race conditions in multi-tasking programs.

5.13.1 Syntax
-------------

     <control_kind> directly_accessed_globals [(<kind> {,<kind>})];
     <kind> ::= plain | accept | protected

5.13.2 Action
-------------

The rule controls global variables declared directly in (generic)
package bodies that are accessed outside of dedicated callable entities
(i.e.  procedure or function, possibly protected, protected entries, and
'accept' statements).

   This rule can be specified only once.  The parameters indicate which
kinds of callable entity are allowed: "plain" for non-protected
subprograms, "protected" for protected subprograms, and "accept" for
'accept' statements).  Without parameters, all forms are allowed.

   More precisely, the rule ensures that the global variables are read
from a single callable entity, and written by a single callable entity.
Note that the same callable entity can read and write a variable, but in
this case no other callable entity is allowed to read or write the
variable.
   * Subprograms used to read/write the variables must be declared at
     the same level as the variable itself (i.e.  not nested), and must
     not be generic.
   * Protected subprograms used to read/write the variables must both be
     part of the same single protected object, which must be declared at
     the same level as the variable itself (i.e.  not nested); they are
     not allowed to be declared in a protected type, since if there are
     several protected objects of the same type, mutual exclusion would
     not be enforced.
   * 'accept' statements used to read/write the variables must both be
     part of the same single task object, which must be declared at the
     same level as the variable itself (i.e.  not nested); they are not
     allowed to be declared in a task type, since if there are several
     task objects of the same type, mutual exclusion would not be
     enforced.
   In short, this rule enforces that all global variables are accessed
by dedicated access subprograms, and that only those subprograms access
the variables directly.  If given with the keyword "protected" and/or
"accept", it enforces that global variables are accessed only by
dedicated protected subprograms or tasks, ensuring that no race
condition is possible.

   Ex:
     check directly_accessed_globals

5.13.3 Tips
-----------

Note that this rule controls global variables from package bodies, not
those from the specification.  This is intended, since it makes little
sense to declare a variable in a specification, and then require it not
to be accessed directly, but through provided subprograms.  Obviously,
in this case the variable should be moved to the body.

   Note that AdaControl can check that no variable is declared in a
package specification with the following rule:
     check usage (variable, from_spec);
   *note Usage:: for details.

5.13.4 Limitations
------------------

AdaControl cannot check entities accessed through dynamic names (dynamic
renaming, access on aliased variables).  Use of such constructs is
detected by the rule "uncheckable".  *Note Uncheckable::.

   Due to a weakness in the ASIS standard, it is not possible to know
the mode (in, out) of variables used as parameters of dispatching calls.
Such variables are considered to be read and written at the point of the
call, therefore possibly creating false positives (which is safer than
false negatives).  Use of such constructs is detected by the rule
"uncheckable".  *Note Uncheckable::.

5.14 Duplicate_Initialization_Calls
===================================

This rule checks that some procedures (notably initialization
procedures) are not called several times in identical conditions.

5.14.1 Syntax
-------------

     <control_kind> duplicate_initialization_calls (<entity> {, <entity>});

5.14.2 Action
-------------

This rule controls calls to initialization procedures that are
duplicated.  The <entity> parameters are the initialization procedures
to be controlled.  As usual, the whole syntax for entities is allowed
for <entity>.  *Note Specifying an Ada entity name::.

   More precisely, the initialization procedures must follow one of
these patterns:
   * The procedure only has 'in' parameters.  All actual parameters used
     in calls are static, and not two calls have the same values for all
     parameters.
   * The procedure has exactly one 'out' parameter (and no 'in out'
     parameter).  Not two calls refer the same actual variable for the
     'out' parameter.

   The rule controls any violation of these patterns.  If a procedure
passed as parameter does not have a profile that corresponds to one of
the above patterns, it is an error.

   Ex:
     check duplicate_initialization_calls (pack.init_proc);

5.14.3 Limitation
-----------------

If a variable passed as an 'out' parameter is not statically
determinable, it is not controlled by the rule.  Such a case is detected
by the rule "uncheckable".  *Note Uncheckable::.

5.15 Entities
=============

This rule is used to control usage of Ada entities, i.e.  any declared
element (type, variables, packages, etc).

5.15.1 Syntax
-------------

     <control_kind> entities ({[not] <location>} [instance] <entity>
                           {, {[not] <location>} [instance] <entity>});
     <location> ::= block   | library | local      | nested    | own |
                    private | public  | in_generic | task_body


5.15.2 Action
-------------

This rule controls all uses of the indicated entities,or only those that
appear within the specified locations.  As usual, the whole syntax for
entities is allowed for <entity>.  *Note Specifying an Ada entity
name::.

   When present, the <location_kw> restricts the places where the entity
is controlled.  If it is preceded by "not", the entity is controlled
except at this location.  Several <location_kw> can be given, in which
case the entity is controlled at places where all the keywords apply.
   * 'block': the entity appears in a block statement.
   * 'library': the entity appears at library level.
   * 'local': the entity appears in a local scope (i.e.  not in
     (generic) packages, possibly nested)
   * 'own': the entity appers in a (generic) package body.
   * 'public': the entity appears in the visible part of a (generic)
     package.
   * 'private': the entity appears directly in a private part.
   * 'in_generic': the entity appears directly or indirectly in a
     generic specification or body.
   * 'task_body': the entity appears directly in a task body.

   If the given entity is a generic unit or an entity declared inside a
generic unit, all corresponding uses in all instances will be reported.
Uses of the generic entity itself will also be reported normally, unless
the keyword 'instance' is given.

   Note that this rules reports on the use of the entity, not the name:
if an entity has been renamed, it will be found under its various names.

   Ex:
     search entities (Debug.Trace);
     check  entities (Ada.Text_IO.Float_IO.Put);
     check  entities (instance Ada.Unchecked_Conversion);
   The second line will report on any use of a 'Put' from any
instantiation of 'Float_IO'.  The third one will report only on uses of
instances of 'Ada.Unchecked_Conversion'.

5.15.3 Tips
-----------

This rule is not intended to replace cross-references, but can be quite
handy to check, for example, that a program does not contain any more
calls to debugging procedures before fielding it.

   This rule can also be used to check for all occurrences of certain
attributes with the "'all <Attribute>'" syntax.  For example, the
following will report on any usage of ''Unchecked_Access':
     check entities (all 'Unchecked_Access);

   If you want to make sure that certain compilation units are not used,
it is preferable to use the rule "Depencies (with,...)"  rather than
"Entities", because "Entities" will control all uses of the unit, while
"Dependencies" will control only those in 'with' clauses (which is of
course sufficient).

   In certain contexts, it can be useful to forbid certain entities,
like those from 'Standard', 'System', or entities defined in special
needs annexes packages.  The 'rules' directory of Adacontrol contains
files with "Dependencies" and "Entities" rules that forbid the use of
various predefined Ada elements.  Comment out the lines for the elements
that you want to allow.  You can then simply "source" these files from
your own rule file (or copy the content) if you want to disallow these
elements.  *Note Rules files provided with AdaControl::.

5.15.4 Limitation
-----------------

GNAT defines 'Unchecked_Conversion' and 'Unchecked_Deallocation' as
separate entities, rather than renamings of 'Ada.Unchecked_Conversion'
and 'Ada.Unchecked_Deallocation'.  As a consequence, it is necessary to
specify explicitely both forms if you want to make sure that the
corresponding generics are not used.

5.16 Entity_Inside_Exception
============================

This rule controls entities that appear within exception handlers.

5.16.1 Syntax
-------------

     <control_kind> entity_inside_exception (<spec> {, <spec>});
     <spec> ::= [not] <entity> | calls | entry_calls

5.16.2 Action
-------------

This rule controls exception handlers that contain references to one or
several Ada entities specified as parameters.  If the keyword "calls" is
given, it stands for all subprogram and entry calls.  If the keyword
"entry_calls" is given, it stands for all entry calls (task or
protected).  If an <entity> (or "calls" or "entry_calls") is preceded by
the keyword "not", it is not included in the list of controlled entities
(i.e.  the entity is allowed in the exception hhandler).  This allows to
make exceptions to a more general specification of an entity, or to
allow calls to well-defined procedures if the keyword "calls" is given.

   Ex:
     -- No Put_Line in exception handlers:
     check entity_inside_exception (ada.text_io.put_line);

     -- No entry calls in exception handlers:
     check entity_inside_exception (entry_calls);

     -- No calls allowed, except to the Report_Exception procedure:
     check entity_inside_exception (calls, not Reports.Report_Exception);

     -- No Put allowed, except the one on Strings:
     check entity_inside_exception (all Put,
                                    not Ada.Text_IO.Put{Standard.String});

5.17 Exception_Propagation
==========================

This rule controls that certain program units are guaranteed to never
propagate exceptions, or that local exceptions cannot propagate out of
their scope.

5.17.1 Syntax
-------------

     <control_kind> exception_propagation
        (local_exception);
     <control_kind> exception_propagation
        ([<level>,] interface, <convention> {, <convention> });
     <control_kind> exception_propagation
        ([<level>,] parameter, <entity> {, <entity>});
     <control_kind> exception_propagation
        ([<level>,] task);
     <control_kind> exception_propagation
        (<level>, declaration);

5.17.2 Action
-------------

The "local_exception" subrule controls a design pattern that ensures
that a local exception cannot propagate outside the scope where it is
declared.  If an exception is declared within a block, a subprogram
body, an entry body, or a task body, then this body must have either a
handler for this exception or for 'others'; this handler must not
reraise the exception; and no handler is allowed to raise explicitely
the exception.  The subrule controls explicit 'raise' statements and
calls to 'Raise_Exception' and 'Reraise_Occurrence', but it does not
control exceptions raised as a consequence of calling other subprograms.

   The other subrules control subprograms, tasks, or all declarations
that can propagate exceptions, while being used in contexts where it is
desirable to ensure that no exception can be propagated.

   A subprogram or task is considered as _not_ propagating if:
  1. it has an exception handler with a "'when others'" choice
  2. no exception handler contains a 'raise' statement, nor any call to
     'Ada.Exception.Raise_Exception' or
     'Ada.Exception.Reraise_Occurrence'.
  3. no declaration from its own declarative part propagates exceptions.

   A declaration is considered propagating if it includes elements that
could propagate exceptions.  This is impossible to assess fully using
only static analysis, therefore the <level> parameter determines how
pessimistic (or optimistic) AdaControl is in determining the possibility
of exceptions.  Possible values of the <level> parameter, and their
effect, are:
   * 0: expressions in declarative parts are not considered as
     propagating (anything allowed, this is the default value for
     "interface", "parameter" and "task".  Not allowed for
     "declaration").
   * 1: all function calls (including operators) in declarations are
     considered as potentially propagating exceptions, except those
     appearing in named number declarations or scalar types
     declarations, since those are required by the language to be
     static.
   * 2: same as 1, plus every use of variables in expressions is
     considered as potentially propagating.
   * 3: same as 2, plus any declaration of objects (constants or
     variables) is considered potentially propagating (not very useful
     for "declaration").

   These subrules serve several purposes:
   * The "interface" subrule analyzes all subprograms to which an
     'Interface' or 'Export' pragma applies (with the given
     convention(s)), and reports on those that can propagate exceptions.

     Since it is dangerous to call an Ada subprogram that can propagate
     exceptions from a language that has no exception (and especially
     C), any such subprogram should have a "catch-all" exception
     handler.
   * The "parameter" subrule accepts one or more fully qualified formal
     parameter names (i.e.  in the form of the parameter name prefixed
     by the full name of its subprogram, see *note Specifying an Ada
     entity name::).  The subrule reports any subprogram that can
     propagate exceptions and is used as the prefix of a ''Access' or
     ''Address' attribute that appears as part of an actual value for
     the indicated formal.  Similarly, the indicated formal can also be
     the name of a formal procedure or function of a generic.  In this
     case, the rule will report on any subprogram that can propagate
     exceptions and is used as an actual in an instantiation for the
     given formal.

     Many systems (typically windowing systems) use call-back
     subprograms.  Although the native interface is generally hidden
     behind an Ada binding, the call-back subprograms will eventually be
     called from another language, and like for the "interface" subrule,
     any such subprogram should have a "catch-all" exception handler.
   * The "task" subrule reports any task that can propagate exceptions.

     Since tasks die silently if an exception is propagated out of their
     body, it is generally desirable to ensure that every task has an
     exception handler that (at least) reports that the task is being
     completed due to an exception.
   * The "declaration" subrule reports any declaration that can
     propagate exceptions, irrespectively of where it appears.  In this
     case, the specification of <level> is required and cannot be 0.

     It is sometimes desirable to make sure that no declaration raises
     an exception, ever.

   Ex:
     -- Make sure that C-compatible subprograms don't propagate exceptions:
     check exception_propagation (interface, C);

     -- Parameter CB of of procedure Pack.Register is used as a call-back
     -- Make sure that not procedure passed to it can propagate exceptions.
     check exception_propagation (parameter, Pack.Register.CB);

     -- Make sure that tasks do not die silently due to unhandled exception:
     check exception_propagation (task);

     -- Make sure that no exception is raised by elaboration of declarations:
     check exception_propagation (2, declaration);

   The first example will report on any subprogram to which a 'pragma
Interface (C,...)' applies that can propagate exceptions.

   If 'Proc' is a procedure that can propagate exceptions, the second
example will report on every call like:
     Pack.Register (CB => Proc'Access);

   The third example will report on any task that can terminate silently
due to an unhandled exception.

   The fourth example will report on any declaration that makes use of
function calls or variables.

5.17.3 Tips
-----------

Note that the registration procedure for a call-back can be designated
by an access type, but in this case, use the name of the formal for the
access type.  For example, given:
     package Pack is
        type Acc_Proc is access procedure;
        type Acc_Reg is access procedure (CB : Acc_Proc);
        ...
        Ptr : Acc_Reg := ...;

   You can give a rule such as:
     check exception_propagation (parameter, Pack.Acc_Reg.CB);
   All procedures registered by a call to 'Pack.Ptr.all' will be
considered.

   The declaration of a for loop parameter is not checked by this rule.
In other words, the rule "check exception_propagation (2, declaration)"
will not issue a message for:
     for I in Positive range 1 .. X loop ...
   although formally the declaration of I could raise Constraint_Error
if X is negative.  We consider that for the casual user,
Constraint_Error appears to be raised by the for loop statement.

5.17.4 Limitations
------------------

An exception may be raised in a subprogram considered as not propagating
by this rule, if an exception handler calls a subprogram that propagates
an exception.

   The rule will not consider subprograms whose body is missing, or that
are not statically known (i.e.  if a subprogram is registered through a
dereference of a pointer to subprogram), like in the following example:
     Pack.Register (CB => Pointer.all'Access);

   Due to a weakness of the ASIS standard, references to subprograms
that appear in dispatching calls are not considered.  This limitation
will be removed as soon as we find a way to work around this problem,
but the issue is quite difficult!

   These last two cases are detected by the rule "uncheckable".  *Note
Uncheckable::.

5.18 Expressions
================

This rule controls usage of various kinds of expressions.

5.18.1 Syntax
-------------

     <control_kind> expressions (<subrule> {, <subrule>});
     <subrule> ::= {<category>} <expression_kw>
     <expression_kw> ::=
        and                              | and_array                  |
        and_binary                       | and_boolean                |
        and_then                         | array_aggregate            |
        array_named_others               | array_non_static_range     |
        array_others                     | array_partial_others       |
        array_positional_others          | array_range                |
        case                             | complex_parameter          |
        downward_conversion              | extendable_aggregate       |
        extension_aggregate              | explicit_dereference       |
        fixed_multiplying_op             | for_all                    |
        for_some                         | if                         |
        if_elsif                         | if_no_else                 |
        implicit_dereference             | in                         |
        inconsistent_attribute_dimension | inherited_function_call    |
        mixed_operators                  | not_in                     |
        or                               | or_array                   |
        or_binary                        | or_boolean                 |
        or_else                          | parameter_view_conversion  |
        prefixed_operator                | real_equality              |
        record_partial_others            | record_aggregate           |
        record_others                    | slice                      |
        static_membership                | type_conversion            |
        upward_conversion                | unconverted_multiplying_op |
        underived_conversion             | universal_range            |
        unqualified_aggregate            | xor                        |
        xor_array                        | xor_binary                 |
        xor_boolean
     <category> ::=
        <>     | ()     | range  | mod | delta   | digits | array    |
        record | tagged | access | new | private | task   | protected

5.18.2 Action
-------------

This rule controls usage of certain forms of expressions.  The rule can
be specified at most once for each subrule (i.e.  subrules that accept
categories can be specified once for each combination of categories and
expression keyword).

   Categories are used by certain subrules to further refine the
control.  They define categories of types to which they apply:
   * "<>": Any type
   * "()": Enumerated types
   * "range": Signed integer types
   * "mod": Modular types
   * "delta": Fixed point types (no possibility to differentiate
     ordinary and decimal fixed point types yet).
   * "digits": Floating point types
   * "array": Array types
   * "record": (untagged) record types
   * "tagged": Tagged types (including type extensions)
   * "access": Access types
   * "new": Derived types
   * "private": Private types
   * "task": Task types
   * "protected": Protected types

   The subrule define the kind of expression being controlled:
   * 'and', 'or', 'xor', 'and_then', 'or_else', 'in', and 'not_in'
     control usage of the corresponding logical operator (or short
     circuit form, or membership test).
   * 'and_array', 'or_array', and 'xor_array' do the same, but only for
     operators whose result type is an array type.
   * 'and_binary', 'or_binary', and 'xor_binary' do the same, but only
     for operators whose result type is a modular type.
   * 'and_boolean', 'or_boolean', and 'xor_boolean' do the same, but
     only for operators whose result type is 'Standard.Boolean'.
   * 'array_aggregate' and 'record_aggregate' control array and record
     aggregates, respectively, while 'unqualified_aggregate' controls
     aggregates (both arrays and records) that do not appear directly
     within a qualified expression.  'extension_aggregate' controls
     extension aggregates, while 'extendable_aggregate' controls
     aggregates that are not extension aggregates, but whose type is a
     non-root tagged type, or are extension aggregates whose ancestor
     part is not their immediate parent (such aggregates could be
     written as extension aggregates).
   * 'array_others' and 'record_others' control the occurrence of a
     'others =>' association in array and record aggregates,
     respectively.
   * 'array_partial_others' and 'record_partial_others' do the same, but
     only if there are other associations in addition to the 'others =>'
     in the aggregate.  'array_named_others' and
     'array_positional_others' do the same, but only for named
     (respectively positional) array aggregates.
   * 'array_range' controls array aggregates that include a range (i.e.
     an association like 'A .. B =>').  'array_non_static_range' does
     the same, but only if (at least) one of the bounds is not static.
   * 'case' controls case expressions (introduced in Ada 2012).
   * 'complex_parameter' controls complex expressions used as actual
     parameters in subprogram (or entry) calls.  A complex expression is
     any expression that includes a function call (including operators).
     This rule is not applied to the parameters of operators, since
     otherwise it would forbid any expression with more than a single
     operator.
   * 'explicit_dereference' controls explicit dereferences of access
     values (i.e.  with an explicit '.all').
   * 'fixed_multiplying_op' controls calls to predefined fixed-point
     multiplication and division (regular fixed-point or decimal-fixed
     point).  'unconverted_fixed_multiplying_op' does the same, but only
     when both operands are objects (not literals) of a fixed_point type
     (not Integer); this is when type conversion is required by Ada 83.
   * 'for_all' and 'for_some' control the two forms of quantifiers
     introduced by Ada 2012.
   * 'if' controls all if expressions (introduced in Ada 2012), while
     'if_elsif' only controls those that have an elsif part, and
     'if_no_else' only controls those that have no else part.
   * 'implicit_dereference' controls implicit dereferences of access
     values (i.e.  when the '.all' is omitted).
   * 'inconsistent_attribute_dimension' controls when no dimension is
     explicitely given for a ''First', ''Last', ''Range' or ''Length'
     attribute and the attribute applies to a multi-dimensional array,
     or conversely, when an explicit dimension is given, but the
     attribute applies to a one-dimensional array.
   * 'inherited_function_call' controls calls to functions that have
     been inherited by a derived type and not redefined.  If a category
     is specified, only calls whose result type belongs to the category
     are controlled.

     Derived types are followed, i.e.  the "real" category from the
     original type is used for the matching; as a consequence, the "new"
     category cannot be specified for this subrule.
   * 'mixed_operators' controls expressions that involve several
     different operators, without parentheses.  In a sense, it extends
     the language rule that forbids mixing 'and' and 'or' in logical
     expressions to all other operators.  Note that for the purpose of
     this subrule, membership tests ('in', 'not in') and short circuit
     forms ('and then', 'or else') are considered operators.
   * 'prefixed_operator' controls calls to operators that use prefixed
     notation (i.e.  '"+"(A, B)').  If a category is specified, only
     calls whose result type belongs to the category are controlled.

     Derived types are followed, i.e.  the "real" category from the
     original type is used for the matching; as a consequence, the "new"
     category cannot be specified for this subrule.
   * 'real_equality' controls usage of predefined exact equality or
     inequality ("=" or "/=") between real (floating point or fixed
     point) values.
   * 'slice' controls usage of array slices.
   * 'static_membership' controls membership tests ('in' and 'not in')
     where the expression on the left is statically known to belong to
     the range (or subtype) on the right, and is therefore always True
     (or false for 'not in').
   * 'type_conversion' controls all (sub)type conversions, while
     'underived_conversion' controls conversions between types that do
     not belong to the same derivation family.  'downward_conversion'
     and 'upward_conversion' control conversions between types that
     belong to the same family, converting away from the root or toward
     the root, respectively.  'parameter_view_conversion' controls
     conversions that appear as 'out' or 'in out' actual parameters.

     One or two categories can be specified; if only one category is
     specified, only conversions whose result type belong to that
     category are controlled.  If two categories are specified, only
     conversions whose souce type belongs to the first category and
     whose target type belong to the second category are controlled.

     Derived types are followed, i.e.  the "real" category from the
     original type is used for the matching; as a consequence, the "new"
     category cannot be specified for this subrule.
   * 'universal_range' controls discrete ranges that are a part of an
     index constraint, constrained array definition, or for-loop
     parameter specification (but not type or subtype defintions), and
     whose bounds are both of type universal_integer.

   Ex:
     search expressions (real_equality, slice);
     check  expressions (mixed_operators);

     -- Find logical operators that could be replaced by short-circuits forms:
     check expressions (and_boolean, or_boolean);

     -- Find all conversions between integer and floating point types
     search expression (range digits type_conversion);

     -- Find all conversions from a fixed point type:
     search expressions (delta <> type_conversion);

     -- Find all view conversions between array types:
     search expressions (array parameter_view_conversions);

     -- Find all "structural" conversions between arrays
     search expressions (array underived_conversion);

     -- Some think that downward conversions of tagged types are evil:
     check expressions (tagged downward_conversion);

5.18.3 Tips
-----------

The 'real_equality' subrule does not control calls to an equality
operator that has been defined by the user; actually, it would make
little sense to write a function and then forbid its use!  However, if
control of calls to such a function is desired, it can be easily
accomplished by using the 'entities' rule.  *Note Entities::.

   This rule does not check the use of allocators ('new'), use the rule
'Allocators' instead.  *Note Allocators::.

   "inherited_function_call" controls only function calls.  For
procedure calls, see rule *note Statements::.

   Specifying 'array_partial_others' is the same as specifying both
'array_named_others' and 'array_positional_others'.  It is retained for
compatibility, and also for symetry with 'record_partial_others'.

   Per language rules, underived conversions are allowed only between
numeric types, and between structurally equivalent array types.

   "static_membership" is handy for finding a common misuse of
membership tests, where the user assigns an external value (obtained
with Unchecked_Conversion for example) to a variable, then checks that
the variable belongs to its subtype to make sure the value is valid.
Such a check can be optimized away by the compiler; the 'Valid attribute
should be used instead.

5.18.4 Limitations
------------------

"static_membership" does not control the complex membership tests with
several choices that are possible with Ada 2012.

5.19 Generic_Aliasing
=====================

This rule controls instantiations where the same actual is given to more
than one formal.

5.19.1 Syntax
-------------

     <control_kind> generic_aliasing [(<subrule> {, <subrule>})];
     <subrule>   ::= [<condition>] <entity>
     <condition> ::= unlikely | possible | certain
     <entity>    ::= all | variable | type | subprogram | package

5.19.2 Action
-------------

This rule identifies instantiations where the same variable, type,
subprogram, or package is given several times (to different formal
parameters).  Such aliasing of variables is dangerous, since it can
induce subtile bugs.  Other elements are less dangerous, although often
questionable (depending on the generic).

   The <entity> parameter indicates for which elements aliasing is
controlled; "all" stands for all kinds of elements.

   There are many cases where aliasing cannot be determined statically.
The optional parameter specifies how aggressively the rule will check
for possible aliasings (see *note Parameter_Aliasing:: for a more
detailed description of these modifiers).  Possible values are (case
irrelevant):
   * Certain (default): Only cases where aliasing is statically certain
     are output.
   * Possible: In addition, cases where aliasing may occur depending on
     the value of an indexed component are output.  This can be
     specified only for variables.
   * Unlikely: In addition, cases where aliasing may occur due to access
     variables designating the same element are output.  This can be
     specified only for variables and subprograms.

   Without any parameter, the rule is the same as "certain all".  The
rule can be specified only once for each combination of <condition> and
<entity>.

   Ex:
     check  generic_aliasing (certain  variable);
     search generic_aliasing (possible variable, type, subprogram, package);

5.19.3 Limitations
------------------

Due to a limitation of ASIS for Gnat, AdaControl might not be able to
differentiate predefined operators of different types, and may thus give
false positives if a generic is instantiated with, for example, two
different functions that are actually '"+"' on Integer and '"+"' on
Float.  This possibility of false positives is detected by the rule
"uncheckable".  *Note Uncheckable::.

5.20 Global_References
======================

This rule controls accesses to global elements that may be subject to
race conditions, or otherwise shared.

5.20.1 Syntax
-------------

     <control_kind> global_references (<subrule> {, <root>});
     <subrule> ::= all | read | written | multiple | multiple_non_atomic
     <root>    ::=  <entity> | function | procedure | task | protected

5.20.2 Action
-------------

This rule controls access to global variables from several entities (the
roots).  The '<entity>' must be subprograms, task types, single task
objects, protected types, or single protected objects.  As usual, the
whole syntax for entities is allowed for <entity>.  *Note Specifying an
Ada entity name::.  The special keywords 'function', 'procedure',
'task', and 'protected' are used to refer to all functions, procedures,
tasks, and protected entities, respectively.

   The <subrule> determines the kind of references that are controlled.
If it is 'all', all references to global elements from the indicated
entities are reported.  If <subrule> is 'read' or 'written', only read
(respectively write) accesses are reported.  If <subrule> is 'multiple',
only global elements that are accessed by more than one of the indicated
entities (i.e.  shared elements) are reported.  Note however that if a
reference is found from a task type or protected type, it is always
reported, since there are potentially several objects of the same type.
If <subrule> is 'multiple_non_atomic', references reported are the same
as with 'multiple', except that global variables that are 'atomic' or
'atomic_components' and written from at most one of the indicated
entities are not reported.  Note that this latter case corresponds to a
safe reader/writer use of atomic variables.

   This rule follows the call graph, and therefore finds references from
subprogram and protected calls made (directly or indirectly) from the
indicated entities.  However, calls to subprograms from the Ada standard
library are not followed.

   Ex:
     -- Find global variables used by P1 or P2:
     search global_references (all, P1, P2);

     -- Find global variables modified by functions:
     check global_references (written, function);

     -- Find possible race conditions:
     check global_references (multiple, task, protected);

   This rule can be given several times, and conflicts (with 'multiple')
are reported on a per-rule basis, i.e.  given:
     check global_references (multiple, P1, P2);
     check global_references (multiple, P1, P3);

   the first rule will report on global variables shared between P1 and
P2, and the second rule will report on global variables shared between
P1 and P3.

5.20.3 Tips
-----------

The notion of "global" is relative, i.e.  it designates every variable
whose scope encloses (strictly) the indicated entities.  This means that
a same reference may or may not be global, depending on the indicated
entity.  Consider:

     procedure Outer is
        Inner_V : Integer;

        procedure Inner_P is
        begin
           Inner_V := 1;
        end Inner_P;
     begin
        Inner_P;
     end Outer;

   The rule
     check global_references (all, outer);
   will not report any global reference, while the rule
     check global_references (all, outer.inner_p);
   will report a reference to 'Inner_V'.  This is as it should be, since
there is no race condition if several tasks call 'Outer', while there is
a risk if several tasks (declared inside 'Outer') call 'Inner_P'.

   Specifying:
     check global_references (all, function);
   will report on any function that access variables outside of their
scope, i.e.  all functions that have potential side effects.  On the
other hand, this check must follow the whole call graph for any function
encountered, and can therefore be quite costly in execution time.

5.20.4 Limitations
------------------

Calls through pointers to subprograms and dispatching calls are unknown
statically; they are assumed to not access any global.  Such calls are
detected by the rule "uncheckable".  *Note Uncheckable::.

5.21 Header_Comments
====================

This rule controls that every compilation unit starts with a
standardized comment.

5.21.1 Syntax
-------------

     <control_kind> header_comments (minimum, <comment lines>);
     <control_kind> header_comments (model, "<file name>");

5.21.2 Action
-------------

If the keyword "minimum" is given as first parameter, this rule controls
that every compilation unit starts with at least the number of comment
lines indicated by the second parameter.  If several forms of headers
are possible, checking that the headers follow the project's standard
requires manual inspection, but this rule is useful to control that unit
headers have not been inadvertantly forgotten.

   If the keyword "model" is given as first parameter, the second
parameter is a string, interpreted as a file name.  If the file name is
not an absolute path, it is interpreted as relative to the directory of
the file that contains the rule, or to the current directory if the rule
is given on the command line.  Each line of the indicated file is a
regular expression, and the rule controls that the corresponding line of
the source file matches the expression.  *Note Syntax of regular
expressions::.  In addition, it is possible to specify a repetition for
a line.  If the first character of a line is a ''{'', the line must have
the following syntax:
     {<min>,[<max>]}
   where <min> and <max> specify the minimum and maximum number of
occurrences of the pattern in the line that follows this one.  <min>
must be at least 0, and <max> must be at least 1, and be equal or
greater than <min>.  If <max> is omitted, it means that the line may
occur any number of times.

   As a convenience, if the first character of a line is a ''*'' it
means that the next line is a pattern that can occur any number of times
(same as '{0,}').  If the first character is a ''+'', it means that the
next line is a pattern that must occur at least once (same as '{1,}').
If the first character is a ''?'', it means that the next line is an
optional pattern (same as '{0,1}').

   Note that the repetition lines all start with a special character
which is not allowed at the start of a regular expression; there is
therefore no ambiguity.  Everything after the special character (or the
closing ''}'') is ignored, and can be used to provide comments.

   This rule can be given at most once with "minimum" for each of
"check", "search", and "count".  The rule can be given only once with
"model" (but it can be given together with one or more "minimum" rules).

   Ex:
     check header_comments (minimum, 10);
     search header_comments (model, "header.pat");
     count header_comments (minimum, 20);
   This makes an error for every unit that starts with less than 10
comment lines, and a warning for units that do not follow the pattern
contained in the file 'header.pat'.  A count of units that start with
less than 20 comment lines is reported.

   Example of a pattern file:
     {1,3} 1 to 3 occurrences of next line
     ^--$
     ^-- Author: .+$
     ^-- Date: \d{2}/\d{2}/\\d{4}$

5.21.3 Tips
-----------

Remember that the lines of the file are regular expressions; every
character that is specially interpreted (like "+", "*", etc.)  must be
quoted with "\" if it must appear textually.  To ease the process of
generating the model file, the directory 'source' contains a script file
for sed named 'makepat.sed'; if you run this script on a file that
contains a standard header, it will produce a pattern file where each
line starts with "^", ends with "$", and every special character is
quoted with "\".

   When the model contains an indication of repeated lines ("*"), the
repetition is not "greedy", i.e.  matching will stop as soon as what
follows the repetition matches.  This is very useful to check header
comments that have sections, but where you don't want to impose a
precise content to each section.  Imagine for example that the structure
is:
   * A comment with "HISTORY"
   * Any number of comment lines
   * A comment with "AUTHORS"
   * Any number of comment lines
   the following pattern will work as expected:
     ^-- HISTORY$
     *
     ^--
     ^-- AUTHORS
     *
     ^--

5.21.4 Limitation
-----------------

Since the "model" subrule analyzes the content of comments, there is a
conflict with the disabling mechanism of AdaControl that uses special
comments.  *Note Disabling controls::.

   Specifically, line disabling is not possible at all.  Block disabling
is possible, provided the disabling line is allowed by the pattern.  In
short, if you want to be able to disable this rule, the first lines of
the model file should be:
     ?
     --##
   i.e.  allow an optional block disabling comment as the first line of
the file.  Note that there is no need to re-enable this rule, since it
is checked only at the start of a compilation unit.

5.22 Improper_Initialization
============================

This rule enforces a coding pattern that ensures that variables and
'out' parameters are properly initialized befor use.

5.22.1 Syntax
-------------

     <control_kind> improper_initialization [(<subrule> {,<subrule>})]
     <subrule> ::= {<extra>} <target>
     <extra>   ::= access | limited | package | return
     <target>  ::= out_parameter | variable | initialized_variable

5.22.2 Action
-------------

This rule controls variables and/or 'out' parameters that are not
"properly" initialized, i.e.  those that are not "safely" initialized,
those that have a useless initialization in their declaration, and those
where the value is known to be used before having been assigned.  The
notion of variable includes the return object of an extended return
statement (Ada 2005+).

   A variable (or 'out' parameter) is considered safely initialized if
there is an initialization expression in its declaration, or if it is
given a value in the first statements of the corresponding body, before
any "non-trivial" statement.  The goal is not to perform a complete
data-flow analysis, but rather to follow a design pattern where all
variables are initialized before entering the "active" part of the
algorithm.  This makes it easier to ensure that variables are properly
initialized.

   "Trivial" statements are:
   * 'null' statements;
   * assignment statements;
   * procedure calls;
   * return statements;
   * raise statements;
   * extended return statements, unless they contain a nested
     non-trivial statement.
   * 'if' and 'case' statements, unless they contain a nested
     non-trivial statement.
   The <target> parameters determines what is to be checked:
   * 'out_parameter' controls that 'out' parameters are safely
     initialized before the first non-trivial statement, and before
     every (trivial) 'return' statement.  Note that 'out' parameters are
     not checked before 'raise' statements, since the language does not
     guarantee that 'out' parameters are transmitted back in the case of
     exceptions.
   * 'variable' controls that local variables are safely initialized
     before the first non-trivial statement.  If the <extra> modifier
     'return' is specified, only return objects of extended return
     statements are controlled.
   * 'initialized_variable' controls variables that are safely
     initialized before the first non-trivial statement, but also have
     an explicit (and therefore useless) explicit initialization in
     their declaration.  If the modifier 'return' is specified, only
     return objects of extended return statements are controlled.
   In all cases, variables used in trivial statements before being
initialized are reported.

   A variable is considered initialized if it is the target of an
assignment statement, or if it is used as an actual for an 'out' (but
not 'in out') parameter of a procedure call.  Variables assigned in 'if'
or 'case' statements must receive a value in all paths to be considered
initialized after the statement.  Note that the variable must be
assigned to globally, i.e.  assigning to some elements of an array, or
some fields of a record, does not count as an initialization of the
variable.

   Some variables are not controlled, unless the corresponding <extra>
modifier is given:
   * Variables declared immediately within a (generic) package
     specification or body, since in general, package state variables
     are initialized through calls to dedicated procedures.  Use the
     "package" modifier to control also package variables.
   * Variables of an access types, or arrays whose components are of an
     access type, since these are always initialized by the compiler.
     Use the "access" modifier to control also variables of an access
     type.
   * Variables of a limited type, since global assignment is not
     available for them.  Use the "limited" modifier to control also
     variables of a limited type.

   This rule can be given only once for each value of <target>.  Without
parameters, it is equivalent to giving all, without any <extra>.

   Ex:
     check improper_initialization (out_parameter);
     check improper_initialization (access limited variable);
     search improper_initialization (initialized_variable);

5.22.3 Tips
-----------

'variable' and 'initialized_variable' control also return objects from
extended return statements, since it would be strange to guarantee safe
initialization of local variables and not return objects.  On the other
hand, the design pattern enforced by this rule may seem to limitative
for regular variables, but it might be desirable to enforce it for
return objects; hence the possibility to limit the rule to return
objects by specifying the 'return' modifier.

5.22.4 Limitations
------------------

Due to a weakness of the ASIS standard, dispatching calls and calls to
procedures that are attributes are not considered for the initialization
of variables.  Note that for attributes, only ''Read' and ''Input' have
an 'out' parameter.

   In the rare case where a variable is initialized by a dispatching
call or an attribute call, this limitation will result in a false
positive.  Such a case is detected by the rule "uncheckable".  *Note
Uncheckable::.  It is then easy to disable the rule for this variable.
*Note Disabling controls::.

   The rule analyzes only initializations and uses that are directly in
the unit, not those from nested units, since these are in the general
case not statically checkable.

   There are other cases where an object is automatically initialized by
the declaration, like controlled types that have redefined the
'Initialize' procedure, records where all components have a default
initialization, etc.  The rule does not consider these as automatically
initialized, as it does for access types.  Maybe later...

5.23 Instantiations
===================

This rule controls all instantiations of a generic, or only
instantiations that are made with specific values of the parameters.
Control can be restricted to instantiations in specified places.

5.23.1 Syntax
-------------

     <control_kind> instantiations (<generic_spec>);
     <generic_spec> ::= {[not] <location_kw>} <entity> {, <formal_spec>}
     <formal_spec>  ::= <entity> | <category> | <> | =
     <location_kw>  ::= all | block   | library | local      | nested |
                        own | private | public  | in_generic | task_body
     <category>     ::= ()      | access    | array | delta  | digits | mod  |
                        private | protected | range | record | tagged | task

5.23.2 Action
-------------

The rule controls instantiations of the specified <entity>.  As usual,
the whole syntax for entities is allowed for <entity>.  *Note Specifying
an Ada entity name::.

   The <location_kw> restricts the places where the occurrence of the
instantiation is controlled.  If it is preceded by "not", the
instantiation is controlled except at this location.  Several
<location_kw> can be given, in which case the instantiation is
controlled at places where all the keywords apply.  If there is no
<location_kw>, it is assumed to be "all".
   * 'all': puts no special restriction to the location.  This keyword
     can be specified for readability purposes, and if specified must
     appear alone (not with other <location_kw>), and "not" is not
     allowed.
   * 'block': only instantiations appearing in block statements are
     controlled.
   * 'library': only library level instantiations are controlled.
   * 'local': only local instantiations are controlled (i.e.  only
     instantiations appearing in (generic) packages, possibly nested,
     are allowed).
   * 'own': only instantiations that are local to a (generic) package
     body are controlled.
   * 'public': only declarations appearing in the visible part of
     (generic) packages are controlled.
   * 'private': only instantiations appearing directly in a private part
     are controlled.
   * 'in_generic': only instantiations appearing directly or indirectly
     in a generic specification or body are controlled.
   * 'task_body': only instantiations appearing directly in a task body
     are controlled.  Note that it would not make sense to have a
     <location_kw> for task specifications, since instantiations are not
     allowed there.

   An instantiation matches if it appears at a specified location (if
any) and either:
  1. No <formal_spec> is given in the rule
  2. The actual parameters of the instantiation match the corresponding
     <formal_spec>, in order (there can be more actual parameters in the
     instantiation than specified in the rule).  An actual parameter
     matches an <entity> at a given place if it is the same entity, or
     if the <entity> designates a (sub)type and the actual is a subtype
     of this type.  As usual, the whole syntax for entities is allowed
     for <entity>.  *Note Specifying an Ada entity name::.  In addition,
     it matches if the actual is a type name that belongs to the
     indicated category:
        * "()": The parameter is of an enumerated type.
        * "access": The parameter is of an access type.
        * "array": The parameter is of an array type.
        * "delta": The parameter is of a fixed point type (it is not
          currently possible to distinguish ordinary fixed point types
          from decimal fixed point types).
        * "digits": The parameter is of a floating point type.
        * "mod": The parameter is of a modular type.
        * "private": The parameter is of a private type (including
          private extensions).
        * "protected": The parameter is of a protected type.
        * "range": The parameter is of a signed integer type.
        * "record": The parameter is of an (untagged) record type.
        * "tagged": The parameter is of a tagged type (including type
          extensions).
        * "task": The parameter is of a task type.

     In addition, two special signs can be given instead of an <entity>
     (or <category>): a box ('<>') matches any actual parameter (i.e.
     it stands for any value), and an equal sign ('=') matches if there
     has been already an instantiation with the same value for this
     parameter (i.e.  it matches the second time it is encountered).

   Formal 'in' parameters cannot be matched, since the actual can be any
expression and it is not clear how to specify it in the rule; therefore,
the rule should normally specify a box ('<>') at the place of such
parameters.

   Ex:
     -- Check all instantiations of Unchecked_Deallocation:
     search instantiations (ada.unchecked_deallocation);

     -- Check all instantiations of Unchecked_Conversion from or to String:
     check instantiations (ada.unchecked_conversion, standard.string);
     check instantiations (ada.unchecked_conversion, <>, standard.string);

     -- Check all instantiations of Unchecked_Conversion from address
     -- to an integer type:
     check instantiations (ada.unchecked_conversion, system.address, range);

     -- Check that Unchecked_Conversion is instantiated only once
     -- for any pair of arguments:
     check instantiations (ada.unchecked_conversion, =, =);

5.23.3 Tips
-----------

The various forms of <formal_spec> make the rule quite powerful.  For
example:
     -- Not two instantiations of Gen with the same first parameter:
     check instantations (Gen, =);

     -- Not two instantiations of Gen with the same first and third parameter:
     check instantiations (Gen, =, <>, =);

     -- Not two instantiations of Gen with the same first parameter if the
     -- second parameter is Pack.Proc:
     check instantiations (Gen, =, Pack.Proc);

     -- Not two instantiations of Gen with the same first parameter if the
     -- second parameter is any procedure named Proc:
     check instantiations (Gen, =, all Proc);

   Note that a generic actual wich is a subtype matches all types (and
subtypes) above it.  Therefore,
     check instantiations (ada.unchecked_deallocation (standard.natural));
   will find only instantiations that use 'Natural', while:
     check instantiations (ada.unchecked_deallocation (standard.integer));
   will find instantiations that use either 'Integer', 'Positive', or
'Natural'.

   If an equal sign ('=') is provided for a formal 'in' parameter, it is
not part of the comparison of existing instantiations (it behaves like a
box ('<>')), i.e.  given:
     generic
        type T1 is private;
        Val : String := "";
     package Gen;

     package body Gen is ...  end Gen;

     package Inst1 is new Gen (Float, "Some Message");
     package Inst2 is new Gen (Float, "Some Other Message");
   and the rule:
     check instantiations (Gen, =, =);
   Adacontrol will issue a message for Inst2 that it has already been
instantiated with the same parameters, although the second ('in')
parameter is different.

5.23.4 Limitation
-----------------

GNAT defines 'Unchecked_Conversion' and 'Unchecked_Deallocation' as
separate entities, rather than renamings of 'Ada.Unchecked_Conversion'
and 'Ada.Unchecked_Deallocation'.  As a consequence, it is necessary to
specify explicitely both forms if you want to make sure that the
corresponding generics are not instantiated.

5.24 Insufficient_Parameters
============================

This rule controls calls to subprograms and entries where the values of
parameters does not provide sufficient information to the reader to
correctly identify the parameter's purpose.

5.24.1 Syntax
-------------

     <control_kind> insufficient_parameters (<max_allowed> {, <entity>});

5.24.2 Action
-------------

<max_allowed> is the maximum number of allowed "insufficient" parameters
(can be 0).  The <entity> parameters designate enumeration types whose
values should be included in the check.  As usual, the whole syntax for
entities is allowed for <entity>.  *Note Specifying an Ada entity
name::.

   An actual parameter is deemed "insufficient" if it is given in
positional (as opposed to named) notation, it is an expression whose
primaries are all numeric literals, or enumeration literals belonging to
one of the types passed as parameters to the rule ('Standard.Boolean'
for example).

   This rule can be given once for each of check, search, and count.
This way, it is possible to have a level considered a warning (search),
and one considered an error (check).

   Ex:
     search Insufficient_Parameters (1, Standard.Boolean);
     check  Insufficient_Parameters (2, Standard.Boolean);

5.24.3 Tips
-----------

This rule does not apply to operators that use infix notation, nor to
calls to subprograms that are attributes, since named notation is not
allowed for these.

   This rule controls the use of positional parameters according to
their values; it is also possible to control the use of positional
parameters according to the number of parameters with the rule
'positional_associations'.  *Note Positional_Associations::.

   Note also that this rules applies only to calls, while
'positional_associations' applies to all forms of associations.

5.25 Local_Access
=================

This rule controls the taking of access values (through the ''Access',
''Unchecked_Access', or the GNAT specific ''Unrestricted_Access'
attributes) of local (i.e.  non global) entities.

5.25.1 Syntax
-------------

     <control_kind> local_access [(<subrule> {,<subrule>})];
     <subrule>   ::= constant | variable | procedure | function |
                     protected_procedure | protected_function

5.25.2 Action
-------------

Without parameters, the rule controls all entities given as prefixes of
''Access', ''Unchecked_Access', or ''Unrestricted_Access' attributes and
reports on those that are not global, i.e.  not defined in (possibly
nested) library packages.

   If parameters are specified, only entities belonging to the
corresponding categories are controlled.

   Ex:
     Dangerous_Objects: check local_access (Constant, Variable);

5.25.3 Tips
-----------

In Ada 95, accessibility rules make sure that taking the ''Access' of an
entity cannot create dangling pointers, but this check can be
circumvented by using ''Unchecked_Access' (but not on subprograms), or
in GNAT, by using ''Unrestricted_Access'.  Moreover, Ada 2005
generalized anonymous access types create more cases where accessibility
levels are dynamically checked.

   Taking an access value on a global entity is never a risk, but every
use of access values designating local entities has a potential of a
failing dynamic accessibility check or even of a dangling pointer.  This
rule is helpful in finding the places that need careful inspection - of
for disallowing taking accesses on anything but global entities.

5.26 Local_Hiding
=================

This rule controls declarations that hide an outer declaration with the
same name.

5.26.1 Syntax
-------------

     <control_kind> local_hiding [(<subrule> {,"<allowed pattern>"})];
     <subrule>   ::= {<exception>}  strict | overloading
     <exception> ::= not_operator           | not_enumeration       |
                     not_identical_renaming | not_different_families

5.26.2 Action
-------------

If "strict" is given (or if there is no subrule), the rule controls
strict hiding (an inner subprogram that overloads an outer one is not
considered hiding).  If "overloading" is given, only subprograms that
overload another subprogram in the same scope or in an outer scope are
controlled.  Note that following the normal Ada model, the declarations
of enumeration literals are considered functions (and thus controlled).

   Modifiers are used to exclude some controls (i.e.  to allow the
corresponding hiding):
   * "not_operator": the subrule does not apply to the declarations of
     operators (i.e.  things like "'"+"'").
   * "not_enumeration": the subrule does not apply to the
     hiding/overloading of enumeration literals by other enumeration
     literals (the rule still applies to the hiding/overloading of
     functions by enumeration litterals, for example).
   * "not_identical_renaming" (only allowed with "strict"): the subrule
     does not apply to renamings where the renaming name is the same as
     the name of the renamed entity.  Such renamings are commonly used
     to provide visibility of identifiers in a controlled way.
   * "not_different_families" (only allowed with "strict"): the subrule
     does not apply if the hiding identifier and the hidden one do not
     belong to the same "family".  Families are either data (constant,
     variables, numbers, etc.), types, subprograms (including entries),
     packages, generics, exceptions, and labels (including block and
     loop names).
   If one or more <allowed pattern> are given, hiding (or overloading)
of identifiers that match one of the patterns are not reported.  The
whole syntax for regular expressions is allowed for the pattern, but the
matching is always case insensitive.  *Note Syntax of regular
expressions::.

   This rule can be given only once for "strict" and once for
"overloading".

   Ex:
     Hiding: check local_hiding (strict);
     Overloading: search local_hiding (not_operator overloading);

5.26.3 Variables
----------------

The rule provides a variable that allows to adjust the verbosity of
messages for the subrule "overloading".

Variable       Values         Default Effect
Overloading_Reportcompact/detaileddetailedif "detailed", when a construct
                                      that overloads several other
                                      constructs is encountered,
                                      "overloading" will issue a message
                                      for each overloaded construct; if
                                      "compact", it will issue a single
                                      message mentionning how many
                                      constructs are overloaded, and a
                                      pointer to the last one.

5.26.4 Tips
-----------

If you have a naming convention like having all tagged types named
"instance" (with a meaningful name for the enclosing package), and if in
addition your package structure follows the inheritance hierarchy (i.e.
a descendent class is in a child package), then all "instance" will hide
each other - but this is of course intended.  Specifying "'^instance$'"
as an allowed pattern will prevent error messages for these
declarations.

   Note that the name is given between "'^'" and "'$'".  Otherwise,
following normal regexp syntax, any identifier containing "instance"
would be allowed.

   A confusion between names belonging to different "families" (as
defined here) always leads to a compilation error; it may be acceptable
to allow local hiding of names belonging to different families, since
there is no risk involved.

5.27 Max_Blank_Lines
====================

This rule controls excessive spacing in the program text.

5.27.1 Syntax
-------------

     <control_kind> max_blank_lines (<max allowed blank lines>);

5.27.2 Action
-------------

This rule controls the occurrence of more than the indicated number of
consecutive blank lines (empty lines, or lines that contain only
spaces).  This rule can be given once for each of check, search, and
count.  This way, it is possible to have a number of blank lines
considered a warning (search), and one considered an error (check).  Of
course, this makes sense only if the number for search is less than the
one for check.

   Ex:
     search max_blank_lines (2);
     check max_blank_lines (5);

5.28 Max_Call_Depth
===================

This rule controls the maximum depth of subprograms (or entry) calls.

5.28.1 Syntax
-------------

     <control_kind> max_call_depth (<allowed depth> | finite {, <entity>});

5.28.2 Action
-------------

Roughly speaking, the call depth is the number of frames that are
stacked by a call: if you call a subprogram that calls another
subprogram that calls nothing, then the call depth is 2.  Note that a
call to a task (not protected) entry has always a depth of 1, since the
accept body that corresponds to the entry is executed on a different
stack.

   The value of the first parameter is the maximum allowed depth, i.e.
the rule will trigger if the call depth is strictly greater than the
indicated value.  A call to a (directly or indirectly) recursive
procedure is considered of infinite depth, and will be therefore
signaled (with an appropriate message) for any value of <allowed depth>.
Alternatively, the keyword "finite" can be given in place of the
<allowed depth>: in this case, only calls to recursive subprograms will
be signalled.

   If entity names are given after the first parameter, they are
interpreted as callable entities that are not to be analyzed, and
assumed of depth 0 (not calling anything else).  As usual, the whole
syntax for entities is allowed for <entity>.  *Note Specifying an Ada
entity name::.  This can be useful, for example, when a subprogram
appears to be recursive (but is not, due to the algorithm), to prevent
all those who call it to be flagged as having infinite call depth.

   This rule can be given once for each of check, search, and count.
This way, it is possible to have a call depth considered a warning
(search), and one considered an error (check).  Of course, this makes
sense only if the number for search is less than the one for check.

   Ex:
     search max_call_depth (9);
     check  max_call_depth (finite);

5.28.3 Variable
---------------

The rule provides a variable that allows to specify how to handle
expression functions (Ada 2012).

Variable           Values  Default Effect
Count_Expr_Fun_Callson/off on      if "on", calls to expression functions
                                   are counted like regular calls; if
                                   "off", such calls are assumed to be
                                   inlined and do not add an extra depth
                                   level.

5.28.4 Tip
----------

It is possible to give the value 0 for <allowed depth>.  Of course, it
would not make sense to forbid all subprogram calls in an Ada program,
but this can be useful for inspection purposes, since every call will be
reported, and the message indicates the depth of the call.

   If the message says that the call depth "is N", it is exactly N. If
the message says that the call depth is "at least N", it means that the
call chain includes a call to a subprogram whose depth is unknown (see
"Limitations" below); "N" is the call depth if this subprogram does not
call anything else.  Of course, the rule issues a message if this
minimal value is greater than the maximum allowed value.

   There is only one set of entities that are forced to depth 0;
therefore, if the control is given several times, each with various
<entity>, all controls will use the union of all entities given.

5.28.5 Limitations
------------------

Calls to subprograms that are attributes are assumed to have a depth of
1.  Calls to predefined operators are assumed to be in-lined (i.e.  a
depth of 0).

   Calls through pointers to subprograms and dispatching calls are
unknown statically; in addition, some subprograms may not have a body
available for analysis, like imported subprograms, or possibly
subprograms from the standard library; they are all assumed to have a
depth of 1.  Such calls are detected by the rule "uncheckable".  *Note
Uncheckable::.

5.29 Max_Line_Length
====================

This rule controls that no line exceeds a given length.

5.29.1 Syntax
-------------

     <control_kind> max_line_length (<max allowed length>);

5.29.2 Action
-------------

This rule controls the maximum length of source lines.  This rule can be
given once for each of check, search, and count.  This way, it is
possible to have a length considered a warning (search), and one
considered an error (check).  Of course, this makes sense only if the
length for search is less than the one for check.

   Ex:
     search max_line_length (80);
     check max_line_length (120);

5.30 Max_Nesting
================

This rule controls excessive nesting of declarations.

5.30.1 Syntax
-------------

     <control_kind> max_nesting ([<subrule>,] <max allowed depth>);
     <subrule> ::= all | generic | separate | task

5.30.2 Action
-------------

If "all" (or no subrule) is given as the first parameter, this rule
controls the nesting of declarative constructs (like subprograms,
packages, generics, block statements...) that exceed a given depth.
Nesting of statements ('loop', 'case') is not considered.

   If "generic" is given as the first parameter, this rule controls the
nesting of generics, ignoring all non-generic units.

   If "separate" is given as the first parameter, this rule controls the
nesting of separate bodies.

   If "task" is given as the first parameter, this rule controls the
nesting of tasks (task types and single task objects), ignoring all
non-task units.

   This rule can be given once for each subrule and each of check,
search, and count.  This way, it is possible to have a level considered
a warning (search), and one considered an error (check).  Of course,
this makes sense only if the level for search is less than the one for
check.

   Note that the value given is the maximum allowed nesting; f.e.  if
the value given for "generic" is 1, it means that a generic inside a
generic is allowed, but not more.

   Ex:
     search max_nesting (5);
     check max_nesting (all, 7);
     check max_nesting (generic, 1);
     check max_nesting (separate, 0); -- Do not allow separate in separate
     check max_nesting (task, 0);     -- Do not allow a task in another task

5.31 Max_Size
=============

This rule controls the maximum size, in source lines of code, of various
statements and declarations.

5.31.1 Syntax
-------------

     <control_kind> max_size (<subrule>, <max allowed lines>);
     <subrule> ::= accept        | block          | case  | case_branch   |
                   if            | if_branch      | loop  | simple_block  |
                   unnamed_block | unnamed_loop   |
                   package_spec  | package_body   | procedure_body |
                   function_body | protected_spec | protected_body |
                   entry_body    | task_spec      | task_body      |
                   unit

5.31.2 Action
-------------

The first parameter is a subrule keyword that determines which elements
are controlled:
   * "accept" controls accept statements.
   * "block" controls all block statements, while "simple_block"
     controls only blocks without a 'declare' part, and "unnamed_block"
     controls only blocks without a name.
   * "loop" controls all loop statement, while "unnamed_loop" controls
     only loops without a name.
   * "if_branch" and "case_branch" control the length of each
     alternative of an 'if' (respectively 'case') statement.
   * "package_spec", "package_body", "procedure_body", "function_body",
     "protected_spec", "protected_body", "entry_body", "task_spec", and
     "task_body" control the length of the declaration of the
     corresponding element.
   * "unit" controls the whole length of compilation units.

   For each kind of element, the indicated value is the maximum allowed
size of the full element; however, for branches ("if_branch" and
"case_branch") it is the maximum size of the sequence of statements in
the branch (i.e., the line that contains the 'elsif' is not counted as
part of an "if_branch").

   This rule can be given once for each of check, search, and count for
each kind of element.  This way, it is possible to have a level
considered a warning (search), and one considered an error (check).  Of
course, this makes sense only if the number of lines for search is less
than the one for check.

   Ex:
     check Max_Size (if_branch, 30);
     search Max_Size (if_branch, 50);
     check Max_Size (unnamed_loop, 20);

5.31.3 Tip
----------

Note that "procedure_body" and "function_body" apply to protected
subprograms as well as regular ones, and that there is no subrule for
the length of the declaration of subprograms.  Such fine specifications
didn't seem useful, but could be added if someone expresses a need for
it.

5.32 Max_Statement_Nesting
==========================

This rule controls the nesting of compound statements.

5.32.1 Syntax
-------------

     <control_kind> max_statement_nesting (<subrule>, <max allowed depth>);
     <subrule> ::= block | case | if | loop | all

5.32.2 Action
-------------

If one of "block", "case", "if", or "loop" is specified, it controls the
nesting of statements of the same kind, i.e.  an 'if' within a 'loop'
within an 'if' counts only 2 for the "if" keyword.  If "all" is
specified, all kinds of compound statements are counted together, i.e.
an 'if' within a 'loop' within an 'if' counts for 3.  This rule can be
given once for each of check, search, and count, and for each of the
subrules.  This way, it is possible to have a level considered a warning
(search), and one considered an error(check).  Of course, this makes
sense only if the level for search is less than the one for check.

   Ex:
     check max_statement_nesting (loop, 3);
     search max_statement_nesting (all, 5);

5.33 Movable_Accept_Statements
==============================

This rule controls statements that are inside accept statements and
could safely be moved outside.

5.33.1 Syntax
-------------

     <control_kind> movable_accept_statements (certain|possible {, <entity>})

5.33.2 Action
-------------

Since it is good practice to block a client for the shortest time
possible, any action that does not depend on the accept parameters
should not be part of an accept statement.

   Statements that involve synchronisation (delay statements, accept or
entry calls...)  are not movable.  Statements (including compound
statements) that reference the parameters of the enclosing accept are
not movable.  In addition, statements that use one of the <entity> given
as parameters are never considered movable.  As usual, the whole syntax
for entities is allowed for <entity>.  *Note Specifying an Ada entity
name::.  Note that if a generic entity, or an entity declared in a
generic package, is given, all statements that use the corresponding
instantiated entity are considered not movable.

   If the first parameter of the rule is 'certain', only statements
after the last non-movable statement are reported.  If the first
parameter is 'possible', a simple data flow analysis is performed, and
every statement that does not reference a variable that appears to
depend (directly or indirectly) on a parameter is also reported.

   Ex:
     check movable_accept_statements (possible, Log.Report_Rendezvous);

5.33.3 Tips
-----------

The list of <entity> given to the rule can be, for example, procedures
whose execution must be part of the accept statement for logical
reasons.  They can also be global variables, when the rendezvous is
intended to prevent concurrent access to these variables.

5.34 Naming_Convention
======================

This rule controls the form of identifiers to make sure that they follow
the project's naming conventions.  Different naming conventions can be
specified, depending on the kind of Ada entity that the name is refering
to.

5.34.1 Syntax
-------------

     <control_kind> naming_convention
        ([root] [others] {<location>} [<type_spec>] <filter_kind>,
         [case_sensitive|case_insensitive] [not] "<pattern>"
         {, ...});
     <location>  ::= global | local | unit
     <type_spec> ::= <entity> | {<category>}
     <category>  ::= ()      | access    | array | delta  | digits | mod |
                     private | protected | range | record | tagged | task
     <filter_kind> ::= All |
                         Type |
                            Discrete_Type |
                               Enumeration_Type |
                               Integer_Type |
                                  Signed_Integer_Type |
                                  Modular_Integer_Type |
                               Floating_Point_Type |
                               Fixed_Point_Type |
                                  Binary_Fixed_Point_Type |
                                  Decimal_Fixed_Point_Type |
                            Array_Type |
                            Record_Type |
                               Regular_Record_Type |
                               Tagged_Type |
                               Interface_Type |
                               Class_Type |
                            Access_Type |
                               Access_To_Regular_Type |
                               Access_To_Tagged_Type |
                               Access_To_Class_Type |
                               Access_To_SP_Type |
                               Access_To_Task_Type |
                               Access_To_Protected_Type |
                            Private_Type |
                               Private_Extension |
                            Generic_Formal_Type |
                         Variable |
                            Regular_Variable |
                            Field |
                               Discriminant |
                               Record_Field |
                               Protected_Field |
                            Procedure_Formal_Out |
                            Procedure_Formal_In_Out |
                            Generic_Formal_In_Out |
                         Constant |
                            Regular_Constant |
                               Regular_Static_Constant |
                               Regular_Nonstatic_Constant |
                            Named_Number |
                               Integer_Number |
                               Real_Number |
                            Enumeration |
                            Sp_Formal_In |
                            Generic_Formal_In |
                            Loop_Control |
                            Occurrence_Name |
                            Entry_Index |
                         Label |
                         Stmt_Name |
                            Loop_Name |
                            Block_Name |
                         Subprogram |
                            Procedure |
                               Regular_Procedure |
                               Protected_Procedure |
                               Generic_Formal_Procedure |
                            Function |
                               Regular_Function |
                               Protected_Function |
                               Generic_Formal_Function |
                            Entry |
                               Task_Entry |
                               Protected_Entry |
                         Package |
                            Regular_Package |
                            Generic_Formal_Package |
                         Task |
                            Task_Type |
                            Task_Object |
                         Protected |
                            Protected_Type |
                            Protected_Object |
                         Exception |
                         Generic |
                            Generic_Package |
                            Generic_Sp |
                               Generic_Procedure |
                               Generic_Function |
                         Renaming |
                            Object_Renaming |
                            Exception_Renaming |
                            Package_Renaming |
                            Subprogram_Renaming |
                               Procedure_Renaming |
                               Function_Renaming |
                            Generic_Renaming |
                               Generic_Package_Renaming |
                               Generic_Sp_Renaming |
                                  Generic_Procedure_Renaming |
                                  Generic_Function_Renaming

5.34.2 Action
-------------

The first parameter defines the kind of declaration to which the rule is
applicable, and other parameters are strings, interpreted as regular
expressions that define the patterns that must be matched (or not).
*Note Syntax of regular expressions::.

   If one or more <location> keyword is specified, the pattern applies
only to identifiers declared at the corresponding place.  Otherwise, the
pattern applies to all identifiers, irrespectively of where they are
declared.  The definition of locations is as follows:
   * "unit": The identifier is the defining name of a compilation unit.
   * "global": The identifier is declared in a package or a generic
     package, possibly nested in other packages or generic packages.
   * "local": All other cases.

   In the case of objects (corresponding to filters in the "variable"
and "constant" families) and functions (in the "function" family), it is
possible to be more specific, depending on the type of the object (or
the return type of the function), as specified by the <type_spec>
modifier.  The <type_spec> modifier is either a single <entity> giving
the type of the object or one or more <category> keywords.  As usual,
the whole syntax for entities is allowed for <entity>.  *Note Specifying
an Ada entity name::.  The meaning of <category> is:
   * "()": The object is of an enumerated type.
   * "access": The object is of an access type.
   * "array": The object is of an array type.
   * "delta": The object is of a fixed point type (it is not currently
     possible to distinguish ordinary fixed point types from decimal
     fixed point types).
   * "digits": The object is of a floating point type.
   * "mod": The object is of a modular type.
   * "private": The object is of a private type (including private
     extensions).
   * "protected": The object is of a protected type.
   * "range": The object is of a signed integer type.
   * "record": The object is of an (untagged) record type.
   * "tagged": The object is of a tagged type (including type
     extensions).
   * "task": The object is of a task type.

   For a given layer of the hierarchy (i.e.  "variable",
"regular_variable"), only the most specific filter is applicable, i.e.
"standard.boolean variable" will apply to all boolean variables, while
plain "variable" will apply to other variables.  See examples below.

   If "case_sensitive" is specified, pattern matching considers casing.
Otherwise ("case_insensitive"), casing is irrelevant.  The default is
"case_insensitive", and can be changed by setting the variable
"Default_Case_Sensitivity", see below.  Note that the rule checks the
name only at the place where it is declared; casing might be different
when the name is used later.

   If a pattern is preceded by "not", then the pattern must not be
matched (i.e.  the rule reports when there is a match).

   The rule will be activated if an identifier is declared that does not
match any of the "positive" patterns (the ones without "not"), or if it
matches any of the "negative" patterns (the ones with a "not").  If only
negative patterns are given, it is implicitely assumed that all other
identifiers are OK. In other words, accepted identifiers must have the
form of (at least) one of the "positive" patterns (if any), but not the
form of one of the "negative" patterns.

   The filter kinds are organized hierarchically, as reflected by
indentation in the syntax above.  To be valid, the name must match the
patterns specified for its own filter, and for all filters above it in
the hierarchy.  For example, a modular type declaration must follow the
rules (if specified) for "all", "type","discrete_type", "integer_type"
and "modular_integer_type".  However, if a filter kind is preceded by
"others", the rule will apply only if there is no applicable positive
pattern deeper in the hierarchy; similarly, if a filter kind is preceded
by "root", no rule above it in the hierarchy is considered (neither for
itself nor its children).  This is useful to make exceptions to a more
general rule.  For example:

     -- All identifiers must have at least 3 characters:
     check naming_convention (all, "...");
     -- And start with an upper-case letter
     -- (will not apply to types and access types, because of "others" and
     --  other rules given below)
     check naming_convention (others all, case_sensitive "^[A-Z]");

     -- Exception to the rule for "all":
     -- No minimum length for "for loop" identifiers, but must be
     -- all uppercase
     check naming_convention (root loop_control, case_sensitive "^[A-Z]+$");

     -- Types must start with "t", then an upper-case letter:
     -- (will not apply to access types, because of "others" and
     --  other rule given below)
     check naming_convention (others type, case_sensitive "^t[A-Z]");

     -- Access types must start with "ta", then an upper-case letter:
     check naming_convention (access_type, case_sensitive "^ta[A-Z]");

     -- Boolean variables, and only these, must start with "Is_" or
     -- "Has_":
     check naming_convention (variable, not "^Is_", not "^Has_");
     check naming_convention (standard.boolean variable, "^Is_", "^Has_");

     -- Functions returning Wide_String must start with "Wide_", and
     -- similarly for Wide_Wide_String, and no other:
     check naming_convention (standard.wide_string function,
        "^Wide_",
        not "^Wide_Wide_");
     check naming_convention (standard.wide_wide_string function,
        "^Wide_Wide_");
     check naming_convention (function, not "^Wide_");

   It is of course not necessary to specify all the filter kinds, nor to
specify filters down to the deepest level; if you specify a rule for
"type", it will be applied to all type declarations, whether there is a
more specific rule or not.

   Subtypes and derived types must follow the rule for their respective
original (full) type.  Incomplete type declarations are not checked,
since their corresponding full declaration is (normally) checked.
Private types (including of course the full declaration of a private
type) follow the rule for private types, not the rules for their full
type view (otherwise it would be privacy breaking).

   Renamings are treated specially: if there is no explicit rule for a
given renaming, the applicable rule is the one for the renamed entity.

   Ex:
     -- Predefined name is forbidden:
     check naming_convention (all, not "Integer");

     -- Types must either start or end with T
     check naming_convention (type, case_sensitive "^T_",
                                    case_sensitive "_T$");

     -- "Upper_Initials" naming convention:
     check naming_convention
        (all, case_sensitive "^[A-Z][a-z0-9]*(_[A-Z0-9][a-z0-9]*)*$");

     -- All global variables must start with "G_"
     check naming_convention (global variable, "G_");

5.34.3 Variables
----------------

The rule provides a variable that allows to specify the default casing.

Variable           Values  Default Effect
Default_Case_Sensitivityon/offoff  if "on", controls that do not
                                   explicitely specify case sensitivity
                                   are case sensitive.

5.34.4 Tips
-----------

The rule only checks the casing of identifiers at the place where they
are declared.  A useful companion rule is "style (casing_identifier,
original)", which ensures that every use of the identifier will use the
same casing as in the declaration.  *Note Style::.  Similarly, in the
case of a subprogram and its parameters, the check is not done on the
body if there is an explicit specification (since specification and body
have to match anyway).

   The rule does not check the names of operators, since it would make
little sense to have naming conventions for things whose name is
imposed.  If you want to prevent the definition of operators, refer to
the rule "declarations" and its subrules "operator",
"equality_operator", and"predefined_operator".  *Note Declarations::.

   Remember that a Regexp matches if the pattern matches any part of the
identifier.  Use "^" and "$" to match the beginning (resp.  end) of the
name, or both.

   A constant is considered static for the purpose of
"Regular_Static_Constant" and "Regular_Nonstatic_Constant" if it is of a
discrete type initialized by a static expression, or if it is an
aggregate whose components all have static values.  This is different
from the official definition of "static" in the language, but
corresponds to what most users would expect.

   "class_type" is applicable to subtypes that designate a class-wide
type.  Similarly, "access_to_class_type" is applicable to access types
whose designated type is class-wide.

   If you don't want any special rule for renamings (not even the one
that applies to the renamed entity), specify:
     check naming_convention (renaming, "");
   This imposes no constraint on renamings, but since it is specified
explicitely, the implicit rule for the renamed entity won't apply.

   The 'rules' directory of Adacontrol contains two files named
'no_standard_entity.aru' and 'no_system_entity.aru'.  These are files
that contain a naming_convention rule that forbids the declaration of
names declared in packages 'Standard' and 'System', respectively.  You
can simply "source" these files from your own rule file (or copy the
content) if you want to disallow these identifiers.

   Like usual, naming_convention rule can be given multiple times, and
can be disabled.  However, consider the following:
     Rule1 : check naming_convention (constant, "^c_");
     Rule2 : check naming_convention (constant, "^const_");
   The rule will trigger if a constant is declared that does not start
with either "c_" or "const_".  But here, we have two different rule
labels.  The message will refer to the first label encountered in the
rule file; this is the label that must be mentionned in a disabling
comment, unless you simply disable "naming_convention".

5.34.5 Limitations
------------------

This rule does not support wide characters outside the basic Latin-1
set.

5.35 No_Operator_Usage
======================

This rule controls integer types that do not use any arithmetic
operators, which indicates that they might be replaceable with other
kinds of types.

5.35.1 Syntax
-------------

     <control_kind> no_operator_usage [([<category>] <parameter> [,<parameter>])];
     <category>  ::= range | mod
     <parameter> ::= [<filter>] <observed>
     <filter>    ::= not | ignore | report
     <observed>  ::= relational | logical | indexing

5.35.2 Action
-------------

This rule controls integer types where no arithmetic operator of the
type is used in the program.  If the <category> is 'range', the control
applies only to signed integer types; if it is 'mod', it applies only to
modular integer types; otherwise, it applies to both.

   When such a type is found, it migh be interesting to find out other
usages to determine a possible better kind of type.  "relational" means
that relational operators ('<', '<=', '>', '>=', 'in', 'not in') are
used, "logical" means that logical operators ('and', 'or', 'xor') are
used, and "indexing" means that the type is used as an index in some
array type.

   If an <observed> property is given as parameter, only types that
feature the property are controlled, or those that do not feature the
property if the <observed> is preceded by "not".  If the <observed> is
preceded by "ignore" the type is controlled irrrespectively of the
property, and the message does not mention it at all, while if it is
preceded by "report", the message still mentions whether the <observed>
is used or not.

   Without parameters, the rule is equivalent to "ignore relational,
ignore logical, ignore indexing" (i.e.  it controls all types that do
not use any arithmetic operator).

   This rule can be given only once for each combination of values of
the parameters.

   Ex:
     -- Simply report types that don't use arithmetic operators:
     check no_operator_usage;

     -- Do the same, but mention if indexing/logical ops are used:
     check no_operator_usage (report indexing, report logical);

     -- Find modular integer types that use only logical operators:
     check no_operator_usage (mod logical);

     -- Find integer types that don't use artihmetic operators and are
     -- not used for indexing nor in relational operators:
     check no_operator_usage (not indexing, not relational);

5.35.3 Tips
-----------

An integer type that uses no operator at all is a good candidate to be
replaced by an enumerated type.  A modular type where only logical
operators are used is likely to be used as a bit field or a set, and is
a good canditate for being replaced by an array of booleans.

   The rule does not make a distinction between predefined and
user-defined operators.  On the other hand, only calls to operators are
considered, operators used for example as actual generic parameters in
instantiations are not considered.

   The rule applies also to private types whose full declaration is an
integer type.

5.36 Non_Static
===============

This rule controls that expressions used in certain contexts are static.

5.36.1 Syntax
-------------

     <control_kind> non_static [(<subrule> {, <subrule>})];
     <subrule> ::= constant_initialization | variable_initialization |
                   index_constraint        | discriminant_constraint |
                   instantiation           | index_check

5.36.2 Action
-------------

The <subrule> defines the elements that are required to be static:
   * "constant_initialization": expressions used as initial value in
     constant declarations.
   * "variable_initialization": expressions used as initial value in
     variable declarations.
   * "index_constraint": expressions used in index constraints (aka
     array sizes).
   * "discriminant_constraint": expressions used in discriminant
     constraints
   * "instantiation": expressions used as generic actual parameters in
     instantiations.
   * "index_check": expressions used as indices must satisfy statically
     the index check.  I.e., the expression needs not be static, but it
     should be statically provable that the index check cannot fail.

   If no keyword is given, all contexts are controlled.

   Ex:
     check non_static (index_constraint);

5.36.3 Limitations
------------------

Currently, "constant_initialization" and "variable_initialization" do
not control structured (record and array) variables.  For access
variables, the initial value is considered static only if it is a plain
'null'.  This may improve in future versions of AdaControl.

5.36.4 Tips
-----------

If all index and discriminant constraints are static, the space occupied
by data structures is computable from the program text.  This rule is
useful to enforce this in contexts where the memory space must be
statically determined.

5.37 Not_Elaboration_Calls
==========================

This rule controls that certain subprograms (or allocators) are called
only during program initialization.

5.37.1 Syntax
-------------

     <control_kind> not_elaboration_calls (<entity>|new {, <entity>|new});

5.37.2 Action
-------------

The <entity> parameters are callable entities (procedure, function or
entry calls).  As usual, the whole syntax for entities is allowed for
<entity>.  *Note Specifying an Ada entity name::.  This rule controls
calls to the indicated callable entities, or allocators if "new" is
given, that are performed at any time except during the elaboration of
library packages.

   Ex:
     search not_elaboration_calls (Data.Initialize, new);

5.37.3 Limitations
------------------

Due to an (allowed by ASIS standard) limitation of ASIS-for-Gnat, the
rule will not detect calls to subprograms that are implicitely defined,
like calling a '"+"' on 'Integer'.  Fortunately, it is very unlikely
that the user would want to forbid that kind of calls in non-elaboration
code.

   Note also that calls that cannot be statically determined, like calls
to dispatching operations or calls through pointers to subprograms
cannot be detected either.

5.38 Not_Selected_Name
======================

This rule controls that certain entities are always refered to using
selected notation, even in the presence of 'use' clauses.

5.38.1 Syntax
-------------

     <control_kind> not_selected_name
        (<exception places>, <entity> {, <entity>});
     <exception places> ::= none | unit | compilation | family

5.38.2 Action
-------------

A name is "selected" if it is prefixed by the name of the construct
where it is declared.  Only one level of prefix is required, unless the
prefix itself is the target of a not_selected_name rule.

   The first parameter specifies places where the rule is not enforced,
i.e.  where simple notation is allowed:
   * "none": selected notation is always required.
   * "unit": selected notation is not required within the program unit
     where the entity is declared.
   * "compilation": selected notation is not required within the
     compilation unit where the entity is declared.
   * "family": selected notation is not required within the compilation
     unit where the entity is declared, nor within its (direct or
     indirect) children.

   Other parameters indicate the <entity> to which the rule applies.  As
usual, the whole syntax for entities is allowed for <entity>.  *Note
Specifying an Ada entity name::.

   Ex:
     check not_selected_name (unit, all Instance);
     search not_selected_name (none, Pack.T);

5.38.3 Tip
----------

Note that, as usual, the entity can be given in the form "all name".
This is especially useful for types that must always be declared with a
special name (like 'Instance', 'Object', 'T') and are intended to be
always used with the name of the enclosing package.

5.39 Object_Declarations
========================

This rule controls various aspects of object (constants and variables)
declarations.

5.39.1 Syntax
-------------

     <control_kind> object_declarations (min_integer_span, <min_spec>
                                                        {, <min_spec>});
     <control_kind> object_declarations (type, <type_spec> {, <type_spec>});
     <control_kind> object_declarations (volatile_no_address);
     <control_kind> object_declarations (address_not_volatile);
     <min_spec>  ::= [constant | variable] <value>
     <type_spec> ::= [constant | variable] <entity>

5.39.2 Action
-------------

The action depends on the subrule.
   * "min_integer_span": controls that every object of an integer type
     has a subtype that covers at least the indicated number of values.
     Different values can be specified for variables and constants; if
     no modifier ("constant" or "variable") is supplied, the value
     applies to both.

     This subrule can be given only once for each combination of
     check/search/count and constant/variable.
   * "type": controls every object whose (sub)type matches <entity>.  As
     usual, the whole syntax for entities is allowed for <entity>.
     *Note Specifying an Ada entity name::.  If the <entity> is a
     subtype, only objects of that exact subtype are controlled; if the
     <entity> is a type, objects declared with the type or any subtype
     of it are controlled.  The control can be restricted to only
     variables or only constants; if no modifier ("constant" or
     "variable") is supplied, both are controlled.

     This subrule can be given only once for each combination of
     <entity> and constant/variable.
   * "volatile_no_address": controls variables that are the target of a
     pragma volatile, but have no address clause.  Constants are not
     controlled, since it would be very strange to have a volatile
     constant...

     Since this subrule has no parameters, it can be given only once.
   * "address_not_volatile": controls variables that have an address
     clause, but are not the target of a pragma volatile.  Constants are
     not controlled, since it would be very strange to have a volatile
     constant...

     Since this subrule has no parameters, it can be given only once.

   Ex:
     check object_declarations (min_integer_span, variable 5, constant 10);

     count object_declarations (min_integer_span, 8);
     -- Same value for variables and constants

     search object_declarations (volatile_no_address);
     search object_declarations (address_not_volatile);

5.39.3 Tip
----------

The "min_integer_span" rule can be useful for detecting variables that
should use an enumerated type rather than an integer type.

5.39.4 Limitation
-----------------

Due to a shortcomming of the ASIS interface, the subrules
"volatile_no_address" and "address_not_volatile" will not detect
variables of a class-wide type that are volatile due to a pragma
volatile applying to the class-wide type.  If the pragma applies to the
variable, the subrule will work correctly.  A pragma volatile applied to
a class-wide type is detected by the rule "uncheckable".  *Note
Uncheckable::.

   Declaring a class-wide _type_ as volatile seems very peculiar
anyway...

5.40 Parameter_Aliasing
=======================

This rule controls aliased use of variables in subprogram calls.

5.40.1 Syntax
-------------

     <control_kind> parameter_aliasing [([with_in] <level>)];
     <level> ::= Certain | Possible | Unlikely

5.40.2 Action
-------------

This rule identifies calls where the same variable is given as an actual
to more than one 'out' or 'in out' parameter, like in the following
example:
     procedure Proc (X, Y : out Integer);
        ...
     Proc (X => V, Y => V);

   If the modifier "'with_in'" is given, aliasing between 'out' or 'in
out' parameters and 'in' parameters is also considered (unless the 'in'
parameter is of a user-defined by-copy type).  Although aliasing of 'in'
parameters is generally considered less of an issue, it can lead to
unexpected results when the parameter is passed by reference.

   There are many cases where aliasing cannot be determined statically.
The optional parameter specifies how aggressively the rule will check
for possible aliasings.  Possible values are (case irrelevant):
   * Certain (default): Only cases where aliasing is statically certain
     are output.
   * Possible: In addition, cases where aliasing may occur depending on
     the value of an indexed component are output.  These may or may not
     be true aliasing, depending on the algorithm.  For example, given:
          Swap (Tab (I), Tab (J));
     there is no aliasing, unless 'I' equals 'J'.

     If all expressions used for indexing in both variables are static,
     the rule will be able to eliminate the diagnosis of aliasing (if
     the values are different).  This avoids unnecessary messages in
     cases like:
          Swap (Tab (1), Tab (2));

   * Unlikely: In addition, cases where aliasing may occur due to access
     variables pointing to the same variable are output.  These may or
     may not be true aliasing, depending on the algorithm, but should
     normally occur only as the result of very strange practices, like
     in the following example:
          type R is
             record
                X : aliased Integer;
             end record;
          X : R;
          Y : Access_All_Integer := R.X'access;
             ...
          P (X, Y.all);
   There will be no false positive with "Certain".  There will be no
false negative with "Unlikely" (but many false positives).  "Possible"
is somewhere in-between.

   The rule may be specified at most once for each value of the
parameter.  This allows for example to "check" for "Certain" and
"search" for "Possible".

   Ex:
     check parameter_aliasing (with_in certain);
     search parameter_aliasing (Possible);

   Note that the rule is quite clever: it will consider partial aliasing
(like a record variable as one parameter, and one of its components as
another parameter), and will not be fooled by renamings.

5.40.3 Limitation
-----------------

Due to a weakness of the ASIS standard, dispatching calls are not
analyzed.  Some calls cannot obviously have aliasing (if there is only
one parameter, or if there are no variables in the parameters f.e.);
other calls are detected by the rule "uncheckable".  *Note
Uncheckable::.

5.41 Parameter_Declarations
===========================

This rule controls various characteristics of the declaration of
parameters for all callable entities (i.e.  functions, procedures and
entries).

5.41.1 Syntax
-------------

     <control_kind> parameter_declarations (<subrule> [,<bounds>] {,<callable>});
     <subrule>  ::= all_parameters       | in_parameters         |
                    defaulted_parameters | out_parameters        |
                    in_out_parameters    | access_parameters     |
                    tagged_parameters    | class_wide_parameters |
                    single_out_parameter
     <bounds>    ::= min|max <value> [, min|max <value> ]
     <callable> ::= function             | procedure             |
                    dispatching_function | dispatching_procedure |
                    protected_function   | protected_procedure   |
                    protected_entry      | task_entry

5.41.2 Action
-------------

The first parameter is a subrule keyword.  "single_out_parameter" has no
parameter; all other subrules require one or two bounds.
   * "all_parameters": Controls callable entities whose number of
     parameters is less than the given "min" or greater than the given
     "max".  "min" defaults to 0 and "max" to infinity.
   * "in_parameters", "out_parameters", "in_out_parameters": Do the
     same, counting only parameters of modes 'in', 'out', or 'in out'
     respectively.
   * "defaulted_parameters": Does the same, counting only parameters
     declared with an explicit default expression.
   * "access_parameters": Does the same, counting only (anonymous)
     access parameters.
   * "tagged_parameters": Does the same, counting only parameters of a
     specific tagged type.
   * "class_wide_parameters": Does the same, counting only parameters of
     a class-wide type.
   * "single_out_parameter": Controls callable entities that have
     exactly one 'out' parameter.  Procedures with a single 'out'
     parameter might be candidates to becoming functions.

   If one or more <callable_kind> is specified after the <value>, the
rule applies only to the corresponding declaration(s), otherwise it
applies to all callable entities.  "dispatching_function" and
"dispatching_procedure" allow different counts for dispatching
subprograms (i.e.  primitive subprograms of a tagged type).  If
"dispatching_function" or "dispatching_procedure" is not explicitely
specified, "function" (conversely "procedure") applies also to
dispatching functions (conversely dispatching procedures).

   This rule can be given once for each of check, search, and count for
each subrule and each kind of entity.  This way, it is possible to have
a level considered a warning (search), and one considered an error
(check).

   Ex:
     -- Callable entities should preferably not have more than 5
     -- parameters, and in any case not have more that 10 parameters,
     check  parameter_declarations (all_parameters, max 10);
     search parameter_declarations (all_parameters, max 5);

     -- All functions must have parameters and no out or in out
     -- parameters (allowed in Ada 2012):
     check parameter_declarations (all_parameters,    min 1, function);
     check parameter_declarations (out_parameters,    max 0, function);
     check parameter_declarations (in_out_parameters, max 0, function);

     -- A regular (not protected) procedure with one out parameter
     -- should be replaced by a function
     check parameter_declarations (single_out_parameter, procedure);

     -- Find all callable entities with class-wide parameters:
     search parameter_declarations (class_wide_parameters, max 0);

     -- Dispatching operations may have only one parameter of a tagged type:
     check parameter_declarations (tagged_parameter,
                                   max 1,
                                   dispatching_function,
                                   dispatching_procedure);

5.41.3 Tips
-----------

This rule applies to generic subprograms as well as to regular ones.  On
the other hand, it does not apply to generic formal subprograms, since
instantiations would only be possible with subprograms which are
supposed to have been already controlled.

   Instantiations are also controlled; the number of parameters is taken
from the corresponding generic.

   Note that this rule controls only "regular" parameters, not generic
formal parameters.

   Note that dispatching operations have necessarily at least one tagged
parameter, although a "max 0" could be specified in the example above.
If you do this, all declarations of dispatching subprograms will be
controlled.  Maybe that's what you want...

5.42 Positional_Associations
============================

This rule controls the use of positional associations (as opposed to
named associations) in all kinds of associations.

5.42.1 Syntax
-------------

     <control_kind> positional_associations [(<subrule>, <max_allowed>
                                              [, <category> {, <entity>}])];
     <subrule>  ::= all | all_positional | same_type
     <category> ::=  [not_operator] call | pragma          | discriminant     |
                     instantiation       | array_aggregate | record_aggregate |
                     enumeration_representation

5.42.2 Action
-------------

The rule controls pragmas, discriminants, calls, aggregates, or
instantiations that use too many positional associations.  The
definition of "too many" depends on the subrule:
   * "all": when positional associations are given in a place where
     there is more than <max_allowed> associations (both positional and
     named).
   * "all_positional": when there is more than <max_allowed> positional
     associations.
   * "same_type": when more than <max_allowed> positional parameters are
     of the same type.

   In addition, a <category> can be specified to restrict the rule to
specific kinds of associations; if not specified, all associations are
controlled.  The categories carry their obvious meaning, with the
distinction that "array_aggregate" applies only to "true" array
aggregates, while "enumeration_representation" applies to the special
array aggregate used in enumeration representation clauses.  Note that
the "same_type" subrule is not allowed for the "pragma" category.  For
"pragma", "call", and "instantiation", entities can also be specified;
such entities are exempted from the rule (i.e.  the rule will not
control these entities).  See examples below.

   For calls, positional association is not reported for operators that
use infix notation (since named notation is not possible); in addition,
if the "not_operator" modifier is specified before the "call" keyword
(not allowed elsewhere), positional association is never reported for
operators, even if they are called with the syntax of a normal function
call (i.e.  'Pack."+" (A,B)').  Calls to subprograms that are attributes
are not reported either, since named notation is not allowed for them.

   This rule can be specified once for each combination of <subrule>,
<category>, and <control_kind>.  This way, it is possible to have a
number of positional associations considered a warning (search), and one
considered an error (check).  Of course, this makes sense only if
<max_allowed> for search is greater than the one for check.  It is also
possible to have different criteria for each category.

   If no parameter is given, it is equivalent to
"'positional_associations (all, 0)'", i.e.  all positional associations
are controlled.

   Ex:
      -- All positional associations:
     check positional_associations;

     -- All positional associations in aggregates:
     check positional_associations(all, 0, array_aggregate);
     check positional_associations(all, 0, record_aggregate);

      -- All positional associations with more than 3 elements:
     search positional_associations (all, 3);

     -- Positional associations in calls with more than 3 params of the same type
     search positional_associations (same_type, 3, call);

     -- Positional associations in calls with more than 2 elements (except
     -- calls to any subprogram called Put)
     search positional_associations(all, 2, call, all put);

5.42.3 Tips
-----------

There are two kinds of calls where the rule does not complain about
usage of positional association: infix operator calls (since requiring
named notation would not allow infix notation any more), and calls to
subprograms that are attributes (since named notation is not allowed for
these).

   For the purpose of the "same_type" subrule, integer literals are
considered of the same type as any parameter of an integer type, and
similarly for other universal values.  The reason is that this rule is
intended to avoid confusion between parameters, when strong typing would
not detect an inversion of parameters for example; such a case would
happen between parameters of a universal type.

   For calls, another rule controls positional associations according to
the value of parameters rather than their number: *Note
Insufficient_Parameters::.

5.43 Potentially_Blocking_Operations
====================================

This rule controls usage of potentially blocking operations (as defined
in LRM 9.5.1 (8..16)) from within protected operations.

5.43.1 Syntax
-------------

     <control_kind> potentially_blocking_operations;

5.43.2 Action
-------------

The rule follows the call graph, starting from every protected
operation, and identifies all (direct and indirect) potentially blocking
operations encountered.  All protected types in the program are
controlled.

   Of course, calls to standard subprograms (notably IOs) that are
defined to be potentially blocking are recognized.

   Ex:
     check potentially_blocking_operation;

5.43.3 Tips
-----------

This rule is very clever at finding potentially blocking operations
resulting from external calls (or requeues) to the current protected
object, even if this happens through a long chain of subprogram calls.
Typically, this happens when a protected operation calls a subprogram,
which in turn makes a call to an operation of the same protected object.
Such calls generally result in dead-locks.

   Therefore, it is advisable to run this rule on any program that
exhibits mysterious (and hard to find) deadlocks that seem to involve
protected objects.

   When a single protected object is being analyzed, the rule will
diagnose a circularity if there is a call to an operation of the same
object in the call chain; however, if a protected type is being
analyzed, the rule will diagnose a circularity if there is a call to any
object of the same type in the call chain.  Although it is possible to
construct examples of this latter case where there is no risk of
deadlock, it is so contrieved that it certainly deserves being looked
at.  But since the call is not 100% certain to be potentially blocking,
the message will tell "possible external call" instead of "external
call" in this case.

5.43.4 Limitation
-----------------

There is one case defined in LRM E.4(17) which is not recognized: remote
subprograms calls.

   Calls through pointers to subprograms, dispatching calls and calls to
generic formal subprograms are unknown statically; they are assumed to
be non potentially blocking.  Such calls are detected by the rule
"uncheckable".  *Note Uncheckable::.

5.44 Pragmas
============

This rule controls usage of one or several specific pragmas.

5.44.1 Syntax
-------------

     <control_kind> pragmas (<pragma spec> {, <pragma spec>});
     <pragma spec> ::= [multiple] all|nonstandard|<pragma name>

5.44.2 Action
-------------

If the special name "nonstandard" is given, then all
implementation-defined and unrecognized pragmas will be controlled.  If
the special name "all" is given, then all pragmas will be controlled.
Otherwise, the parameters are the names of pragmas to be controlled.
Note that <pragma name> must be the simple name of the pragma, since
pragma names are predefined and do not follow the rules for regular Ada
entities.

   If "multiple" is specified before the pragma spec (or the special
name), the corresponding pragma(s) are controlled only if they apply to
multiple entities, because one of the parameters is an overloaded name.

   Ex:
     check pragmas (elaborate_all, elaborate_body);

     -- Search pragma Convention that apply to several entities:
     search pragmas (multiple convention);

5.44.3 Tips
-----------

If "all" and/or "nonstandard" is given together with a specific pragma
name in a "search" or "check" rule, a message is issued only for the
most specific occurrence.  However, for "count", all appropriate
occurrences are counted, i.e.  given the following rules:
     C1 : count pragmas (annotate);
     C2 : count pragmas (nonstandard);
     C3 : count pragmas (all);
   Counter C1 will report the number of occurrences of 'pragma Annotate'
(a non-standard GNAT pragma), counter C2 will report the number of
non-standard pragmas (including occurrences of 'Annotate'), and counter
C3 will report the total number of pragmas (including occurrences of
'Annotate').

5.45 Record_Declarations
========================

This rule controls various aspects of the components of records.

5.45.1 Syntax
-------------

     <control_kind> record_declarations (component, <compo_kind> {,<repr_cond>});
     <compo_kind> ::= <entity>|<category>
     <category>   ::= () | access    | array | delta  | digits | mod | private |
                           protected | range | record | tagged | task
     <repr_cond>  ::= [not] in_variant | aligned | initialized | packed | sized

5.45.2 Action
-------------

The first parameter is a subrule keyword:
   * "Component" controls record components whose type is the indicated
     <entity>, or whose type belongs to the indicated <category>.  If
     the <entity> is a subtype, only record components that are of that
     subtype are controlled.  If the indicated <entity> is a type, all
     record components that are of that type (including subtypes) are
     controlled.  The meaning of <category> is:
        * "()": The component is of an enumerated type.
        * "access": The component is of an access type.
        * "array": The component is of an array type.
        * "delta": The component is of a fixed point type (it is not
          currently possible to distinguish ordinary fixed point types
          from decimal fixed point types).
        * "digits": The component is of a floating point type.
        * "mod": The component is of a modular type.
        * "private": The component is of a private type (including
          private extensions).
        * "protected": The component is of a protected type.
        * "range": The component is of a signed integer type.
        * "record": The component is of an (untagged) record type.
        * "tagged": The component is of a tagged type (including type
          extensions).
        * "task": The component is of a task type.
     If <repr_cond> are specified, the rule controls only record
     components to which all the corresponding representation items
     apply:
        * "in_variant": The component appears inside the variant part of
          the record.
        * "not in_variant": The component appears inside the fixed part
          of the record.
        * "aligned": Either no component clause applies to the
          component, or the corresponding first bit is a multiple of
          'Storage_Unit'.
        * "not aligned": A component clause applies to the component,
          and the corresponding first bit is not a multiple of
          'Storage_Unit'.
        * "initialized": The component has a default initialization
          expression.
        * "not initialized": The component has no default initialization
          expression.
        * "packed": A pragma Pack applies to the component type.
        * "not packed": No pragma Pack applies to the component type.
        * "sized": A component clause applies to the component
          (therefore imposing the size).
        * "not sized": No component clause applies to the component.

   This rule can be specified several times for the "component" subrule.

   Ex:
     -- All record components of a discrete type should be initialized:
     check record_declarations (component, (), not initialized);

     -- The size of all components of type Hardware_Types.Squeezed must
     -- have a component clause:
     check record_declarations (component, Hardware_Types.Squeezed, not sized);

     -- Find unaligned components of a packed array type:
     check record_declarations (component, array, packed, not aligned);

5.45.3 Tips
-----------

It may seem strange to have a rule with only one subrule, but we expect
to add more in the near future.  Stay tuned...

5.45.4 Limitations
------------------

If "[not] aligned" is specified, there are some rare cases where
AdaControl cannot evaluate whether a component is aligned or not; in
this case, it will "assume the worse" (i.e.  report as if the component
had the specified alignment), thus creating possible false positives.
Such cases are detected by the rule "uncheckable".  *Note Uncheckable::.

5.46 Reduceable_Scope
=====================

This rule controls declarations that could be moved to some inner scope.

5.46.1 Syntax
-------------

     <control_kind> reduceable_scope [(<subrule> {, <subrule>})];
     <subrule> ::= {<restriction>} all        | variable | constant |
                                   subprogram | type     | package  |
                                   exception  | generic  | use
     <restriction> ::= no_blocks | to_body

5.46.2 Action
-------------

The rule reports on any declaration that is referenced only from a
single, inner scope, or in the case of 'use' clauses, it will report on
packages named in a 'use' clause whose elements are used only in a
single, inner scope.  For entitities declared in package specifications,
the rule reports if they are used only from the corresponding package
body.

   The initialization of an object is considered a usage of the object
at the place where it is declared, thus preventing it from being moved.
Therefore, constants and initialized variables are never reported as
being movable to inner scopes; they are reported as being movable to
package bodies however.  Entities that are used as prefixes of a 'Access
or 'Address attribute are never reported, since moving them would change
their accessibility level.  Similarly, task objects are not reported
since moving them would change their master.  Finally, dispatching
operations (primitive operations of tagged types) are not reported
either, since they can be the target of an "invisible" (dispatching)
call.

   If no <subrule> is given, or the <subrule> is "all", all declarations
are controlled.  If 'no_blocks' is specified in front of a <subrule>,
the rule will not consider blocks as possible targets for a reduced
scope for the corresponding category.  If 'to_body' is specified in
front of a <subrule>, the rule will report only elements declared in a
package specification that could be moved into the body.  Specifying
"all" explicitely is only useful in the case where there is a
<restriction>.

   As a side effect, the rule will report about entities that are
declared but not used (i.e.  whose scope reduces to nothing).

   Ex:
     -- Types and variables shall be declared in the innermost scope
     -- where they are useful:
     check reduceable_scope (variable, type);

     -- Packages and subprograms shall be declared in the innermost
     -- scope where they are useful, but they are not allowed in blocks:
     check reduceable_scope (no_blocks subprogram, no_blocks package);

     -- Use clause should be as restricted as possible:
     search reduceable_scope (use);

5.46.3 Tips
-----------

If you think that 'use' clauses are acceptable, but should be limited to
the smallest possible scope, you would generally specify:
     check unnecessary_use_clause;
     check reduceable_scope (use);

5.46.4 Limitation
-----------------

Currently, the rule does not report 'use' clauses declared in a package
specification that could be moved to the body.  Such clauses appear as
"unused" (but of course, the compiler will complain on the body if the
clause is removed).

5.47 Representation_Clauses
===========================

This rule controls usage of representation clause.

5.47.1 Syntax
-------------

     <control_kind> representation_clauses [(<subrule> {, <subrule>})];
     <subrule> ::= {<category>} <repr_kw> | [global] [object] <attribute>
     <repr_kw> ::=
        at                    | at_mod                | enumeration         |
        fractional_size       | incomplete_layout     | layout              |
        non_aligned_component | non_contiguous_layout | no_bit_order_layout |
        overlay
     <category> ::=
        ()     | range     | mod    | delta | digits  | array | record   |
        tagged | extension | access | new   | private | task  | protected

5.47.2 Action
-------------

Without parameter, the rule controls all representation clauses,
otherwise it will control the representation clauses given as parameter.

   If a representation keyword or attribute is preceded by one or
several categories, the rule controls only the representation items that
apply to types belonging to the categories (the type of the component
for the 'non_aligned_component' subrule):
   * "()": Enumerated types
   * "range": Signed integer types
   * "mod": Modular types
   * "delta": Fixed point types (no possibility to differentiate
     ordinary and decimal fixed point types yet).
   * "digits": Floating point types
   * "array": Array types
   * "record": (untagged) record types
   * "tagged": Root tagged types
   * "extension": Type extensions (tagged derived types)
   * "access": Access types
   * "new": Derived types
   * "private": Private types
   * "task": Task types
   * "protected": Protected types

   The meaning of the representation keywords is:
   * "at" controls address clauses given in Ada 83 style ("for XXX use
     at").
   * "at_mod" controls alignment clauses given in Ada 83 style ("for T
     use record at mod XX;").
   * "enumeration" controls enumeration representation clauses.
   * "fractional_size" controls size clauses whose value is not an
     integral multiple of 'System.Storage_Unit'.
   * "incomplete_layout" controls record representation clauses that
     miss the specification of some components of the record's type.
   * "layout" controls all record representation clauses, while
     "no_bit_order_layout" controls record representation clauses whose
     type is not also the target of a bit_order attribute specification
     (such types have a non-portable representation).
   * "non_aligned_component" controls components that do not start on a
     storage unit boundary.  The message gives the offset (in bits)
     relative to the closest storage unit boundary.
   * "non_contiguous_layout" controls record representation clauses
     where there are unused bits between components (or before the first
     component).  A message is issued for each "gap" between components.
     In addition, if a size clause is given for the type, the rule will
     report if there are unused bits at the end of the component (i.e.
     the size clause is bigger than the end of the last component).  In
     the case of variant records, there can be overlapping fields; the
     rule will control only the bits that belong to no variant at all.
   * "overlay" controls address clauses (given in either style), where
     the value given is the ''Address' of some other element.

   In addition to these keyword, any specifiable attribute can be given
(including the initial "'''"); the rule will control specifications of
this attribute.  If the modifier "global" is given before the attribute,
only attribute specifications for global entities are controlled.  If
the modifier "object" is given before the attribute, only attribute
specifications for objects are controlled (as opposed to types for
example).  Note that double attributes (like "''CLASS'INPUT'") can be
given, and are considered different from the simple attribute
("''INPUT'").  It is of course possible to specify both.

   Ex:
     All_Addresses: check representation_clauses (at, 'address);
     All_Input: check representation_clauses ('input, 'class'input);
     Sized_Objects: check representation_clauses (object 'size);
     count representation_clauses ('SIZE);

     -- check layout clauses for derived types:
     check representation_clauses (new layout);

     -- check layout clauses for root tagged types and type extensions:
     check representation_clauses (tagged extension layout);

5.47.3 Limitation
-----------------

For the "fractional_size" and "non_contiguous_layout" subrules, there
are some rare cases where AdaControl cannot evaluate the given size or
elements of the record representation clause, and thus not detect the
corresponding situation.  Such cases are detected by the rule
"uncheckable".  *Note Uncheckable::.

5.47.4 Tips
-----------

The specifiable attributes (the ones that can be given as parameters to
this rule) are ''Address', ''Size', ''Component_Size', ''Alignment',
''External_Tag', ''Small', ''Bit_Order', ''Storage_Pool',
''Storage_Size', ''Write', ''Output', ''Read', ''Input', and
''Machine_Radix'.  See Ada Reference Manual 13.3(77).

   Ada allows partial record representation clauses, i.e.  it does not
require all fields to be specified.  This means that if you add a field
to a record and forget to update the associated representation clause,
there will be no compilation error.  The "incomplete_record" subrule is
handy for making sure that this does not happen.

   Derived types with a representation clause may suffer an efficiency
penalty, since calling an inherited subrograms requires a change of
representation.  Representation clauses for tagged types are dubious,
since these types have hidden fields added by the compiler.

5.48 Return_Type
================

This rule controls that certain form of types are not used for function
results.

5.48.1 Syntax
-------------

     <control_kind> return_type [(<subrule> {, <subrule>})];
     <subrule> ::= class_wide                  | limited_class_wide  |
                   constrained_array           | protected           |
                   task                        | unconstrained_array |
                   unconstrained_discriminated | anonymous_access

5.48.2 Action
-------------

This rule controls functions whose return type belongs to one of the
indicated type kinds:
   * 'class_wide' controls all class-wide types, while
     'limited_class_wide' controls only limited class-wide types.
   * 'constrained_array' controls constrained array types
   * 'unconstrained_discriminated' controls types with discriminants
     (but not constrained subtypes of such types)
   * 'unconstrained_array' controls unconstrained array types
   * 'task' controls task types, or composite types that include tasks
     as subcomponents.
   * 'protected' controls protected types, or composite types that
     include protected objects as subcomponents.
   * 'anonymous_access' controls anonymous access types.

   If no subrule is specified, all type kinds are controlled.  Note that
more than one kind may apply to a type: for example, a function can
return a class-wide type with discriminants that includes tasks and
protected objects as subcomponents.  In this case, several messages are
issued for the same type.

   Ex:
     check return_type (unconstrained_discriminated, unconstrained_array);

5.49 Side_Effect_Parameters
===========================

This rule controls calls that may depend on the order of evaluation of
parameters.

5.49.1 Syntax
-------------

     <control_kind> side_effect_parameters (<entity> {, <entity>});

5.49.2 Action
-------------

This rule controls subprogram calls or generic instantiations where
different actual parameters call functions known to have side effects.
This is dangerous practice, since correct behaviour may depend on a
certain evaluation order of parameters, which is not specified by the
language.

   All <entity> are functions that are assumed to interfere, i.e.  the
rule will signal if any of these functions is called more than once in
the parameters of a call.  As usual, the whole syntax for entities is
allowed for <entity>.  *Note Specifying an Ada entity name::.

   It is allowed to give the name of a generic function, or of a
function declared in a generic package; in this case, all functions
resulting from instantiations of these generics will be considered.

   In the case of renamings, you must give the name of the original
function; the rule will work correctly if the call is made through a
renaming of this function.

   Ex:
     check side_effect_parameters (F1);
     check side_effect_parameters (G1, G2);

   Here, F1 has a side effect, and the rule will signal if it is called
more than once.  G1 and G2 are assumed to interfere, and therefore the
rule will signal if either is called more than once, or if both are
called.  However, having a call that mentions F1 and G2 is OK.

5.49.3 Limitation
-----------------

Due to the size of internal structures, this rule may not be given more
than 100 times.

   Due to an unimplemented feature of ASIS-for-Gnat, this rule will not
process defaulted parameters, and hence not detect interferences due to
calling a side-effect function through the default value.

5.50 Silent_Exceptions
======================

This rule controls exception handlers that can cause exceptions to
silently disappear.

5.50.1 Syntax
-------------

     <control_kind> silent_exceptions (<element> {, <element>});
     element      ::= <control-item> | <report-item>
     control-item ::= not | with   <entity> | others
     report-item  ::= raise   | explicit_raise | reraise | return |
                      requeue | <entity>

5.50.2 Action
-------------

The rule controls handlers that do not call one of the given subprograms
(for example a reporting procedure) nor perform other required
operations, like returning, requeuing, or re-raising an exception.

   A parameter that starts with "not" or "with" is a <control-item> and
defines wich exceptions are controlled; the <entity> should be either an
exception, or the name of a library unit (in which case, it applies to
all exceptions declared in the library unit).  As usual, the whole
syntax for entities is allowed here.  *Note Specifying an Ada entity
name::.  If the <entity> is (part of) a generic, then it applies to all
exceptions from all corresponding instantiations.  If there is no
<control-item>, then all exceptions are controlled.

   If several <control-item> are given, the ones with "with" add
exceptions to the set of controlled exceptions, and the ones with "not"
remove exceptions, in order, starting from the empty set if the first
<control-item> is a "with", or starting from the set of all exceptions
if the first <control-item> is a "not".  See examples below.

   "'when others'" handlers are always controlled, unless there is an
explicit "not others" <control-item>.  A "with others" <control-item>
can be specified to check _only_ "'when others'" handlers.

   The other parameters are <report-item> and define the constructs
considered "reporting".  <entity> should correspond to an Ada callable
entity or generic package; as usual, the whole syntax for entities is
allowed here.  *Note Specifying an Ada entity name::.  If a generic
procedure or function is given, then all corresponding instances are
considered reporting subprograms.  If a generic package is given, any
instantiation (in an inner block of the handler) is considered
reporting.  In addition, the special names "explicit_raise", "reraise",
"return" and "requeue" mark raise statements with an explicit exception
name, raise statements without an exception name, return statements
(including extended return statements), and requeue statements
(respectively) as reporting.  "raise" is a shorthand for both
"explicit_raise" and "reraise".

   If "explicit_raise" is given as a parameter, the procedure
'Ada.Exceptions.Raise_Exception' is automatically added to the list of
procedures for both Check and Search, unless it is explicitely specified
as a parameter in a rule; and similarly
'Ada.Exceptions.Reraise_Occurrence' is added for "reraise".  This way,
it is possible to consider them as reporting procedures for Check (for
example) and not for Search.

   A handler where _all_ exceptions are uncontrolled is not controlled
at all (i.e.  it is allowed to be non reporting).  Otherwise, the rule
reports if the handler does not contain at least one of the
<report-item> in each possible path of the handler.  If the
<report-item> appear only in 'if' or 'case' statements, but not in all
possible paths, or if they appear only in the body of 'loop' statements,
the rule will issue a message asking for a manual verification, since it
cannot be statically determined whether the proper treatment happens in
every case.

   Note that the purpose of this rule is to require the reporting calls
to be "eye-visible", i.e.  textually written in the exception handler.
For example, the rule will accept a call to a procedure inside the
sequence of statements of a package body declared in some inner block;
however, it will not accept the same call if it is in the sequence of
statements of a package instantiation (unless the generic package is
itself mentionned as reporting), because the call is not "eye-visible".
For the same reason, a call to a reporting function which happens as the
default value of an omitted parameter in some other call will not be
accepted.

   This rule can be given once for each of check, search and count.
This way, it is possible to have a level considered a warning (search),
and one considered an error (check).

   Ex:
     -- Make an error if exception is not reraised and does not call
     -- Reports.Trace, but make it only a warning if the exception is an
     -- IO exception or Constraint_Error:
     check silent_exceptions (not ada.io_exceptions,
                              not standard.constraint_error,
                              raise,
                              reports.trace);
     search silent_exceptions (raise, reports.trace);

     -- check handlers that do not reraise the exception, except for
     -- IO exceptions:
     check silent_exceptions (not Ada.IO_Exceptions, reraise);

     -- Same for predefined exceptions, except Constraint_Error:
     check silent_exceptions (not Standard, with Standard.Constraint_Error,
                              reraise);

     -- Same for all exceptions named User_Error, wherever they are declared,
     -- and no others
     check silent_exceptions (with all User_Error, reraise);

     -- Same for "when others" handlers
     check silent_exceptions (with others, reraise);


5.50.3 Limitations
------------------

Currently, "return" includes all return statements.  It would be nice to
separate function returns from procedure or accept returns.  This is
expected to be done in some future version of AdaControl.

   There are two cases that are not statically checkable, and thus may
not be identified by this rule: if an exception is raised in an inner
block statement and handled locally, and if the exception handler aborts
the current task.

   If a reporting function is given, there are a few cases where the
calls will not be recognized:
   * inside a pragma
   * in a representation clause
   * in a code statement (i.e.  as a field of a machine code
     instruction)
   This limitation is intentional: these are such weird places to call a
reporting function that it seems better to draw attention to it...

5.51 Simplifiable_Expressions
=============================

This rule controls expressions that can be simplified in various ways.

5.51.1 Syntax
-------------

     <control_kind> simplifiable_expressions [(<subrule> {, <subrule>})];
     <subrule> ::= conversion   | logical     | logical_false | logical_not |
                   logical_true | parentheses | range

5.51.2 Action
-------------

Without parameters, all kinds of simplifiable expressions are
controlled; otherwise, the controlled expressions depend on the subrule:
   * "conversion" controls type conversions where the expression is of a
     universal type (a litteral or named number), or where the target
     subtype is either the same as the expression's subtype, or the
     first named subtype of the expression.
   * "logical_true" controls redundant boolean expressions of the form
     '<expr> = True' (or '/='), and "logical_false" does the same for
     comparisons with 'false'.
   * "logical_not" controls 'not' operators whose argument is a
     comparison (which could be inverted).
   * "logical" is the same as specifying "logical_true", "logical_false"
     and "logical_not".
   * "parentheses" controls unnecessary parentheses like those
     surrounding the expression of an assignment, an "if" or a "case"
     statement, or those that are not required by operators precedence
     rules.
   * "range" controls expressions of the form 'T'First .. T'Last' that
     should be 'T'range' (or even simply 'T').

   This rule can be given at most once for each subrule.

   Ex:
     search simplifiable_expressions (parentheses);
     check  simplifiable_expressions (range, logical);

5.51.3 Tips
-----------

There are cases where parentheses may seem unnecessary, but are
(purposedly) not reported by this rule.  Consider for example:
        X := A + (B + C);
   Removing the parentheses would change the expression to mean:
        X := (A + B) + C;
   If the '"+"' operator has be redefined and is no more associative,
this would actually change the meaning of the program.  In a less
contrieved example, note that:
       X mod (A*B)
   is not the same as:
       X mod A * B
   For these reasons, and to make the rule easier to understand for the
user, the rule does not report unnecessary parentheses between operators
of identical priority levels.

   Conversion of universal value is never necessary, however there are
cases where overloading resolution may require the conversion to be
replaced by a qualification, rather than being simply removed.

5.52 Simplifiable_Statements
============================

This rule controls statements that can be removed or simplified in
various ways without changing the meaning of the program.

5.52.1 Syntax
-------------

     <control_kind> simplifiable_statements [(<subrule> {, <subrule>})];
     <subrule> ::= block  | dead | handler        | if          | if_for_case |
                   if_not | loop | loop_for_while | nested_path | null

5.52.2 Action
-------------

Without parameter, all kinds of simplifiable statements are controlled;
otherwise, the controlled statements depend on the subrule:
   * 'block' controls block statements that have no labels, no
     declarations, and no exception handlers.
   * 'dead' controls dead code, i.e.  statements that are statically
     known to be never executed.  This includes statements that follow a
     'return', 'requeue', or 'goto' statement, or an 'exit' statement
     that is either unconditional or whose condition is statically known
     to be true.  It includes also 'while' statements and 'if'
     statements (including 'elsif' paths) whose condition is statically
     false, and 'for' loops whose range is statically empty.
   * 'handler' controls "trivial" exception handlers, i.e.  handlers
     whose sequence of statements includes only a single 'raise'
     statement without an exception name.  However, a handler is not
     reported if there is also a non trivial handler for 'others'.
     These examples show the situation:
          exception
             when Constraint_Error =>  -- Reported (no when others)
                raise;
          end;

          exception
             when Constraint_Error =>  -- Reported (trivial when others)
                raise;
             when others =>        -- Reported
                raise;
          end;

          exception
             when Constraint_Error =>  -- Not reported (non trivial when others)
                raise;
             when others =>
                Put_Line ("Error");
          end;
   * 'if' controls 'if' statements with an 'else' path that contains
     only 'null' statements (and can thus be removed).
   * 'if_for_case' controls usage of 'if' statements that could be
     replaced by 'case' statements.  An 'if' statement is assumed to be
     replaceable if it has at least one 'elsif' and all conditions are
     comparisons (or membership tests, possibly connected by logical
     operators) of the same discrete variable with static values.
     Typically, this subrule will spot constructs like:
             if X = 1 then
                ...
             elsif X = 2 or X = 3 or X = 4 then
                ...
             elsif X >= 5 and X <= 10 then
                ...
             elsif X in 11 .. 20 then
                ...
             else
                ...
             end if;
   * 'if_not' controls 'if' statements with an 'else' path and no
     'elsif' path, and where the condition is given in negative form
     (i.e.  it is a 'not', or a '"/="' comparison).  Such statements
     could be made positive (and thus less error-prone) by interverting
     the 'if' and 'else' paths.
   * 'nested_path' controls paths from 'if' statements that can be moved
     outside.  This happens if the 'if' has only 'then' and 'else'
     paths, and either of them ends with a "breaking" statement
     ('raise', 'return', 'exit' or 'goto'); in this case, the other path
     needs not be nested inside the 'if' statement.  However, if both
     paths end with the same "breaking" statement, no error is reported.
     In short, the rule signals the following examples:
          if Cond then
             return;
          else
             I := 1;
          end if;

          if Cond then
             I := 1;
          else
             return;
          end if;
     because they can be changed to:
          if Cond then
             return;
          end if;
          I := 1;

          if not Cond then
             return;
          end if;
          I := 1;
     The rule will not signal the following example, where both paths
     end with the same "breaking" statement ('return'), because it would
     break the symetry of the statement:
          if Cond then
             return 1;
          else
             return 2;
          end if;
   * 'null' controls 'null' statements that serve no purpose and can be
     removed.  Note that if a 'null' statement carries a label, it is
     not considered simplifiable.
   * 'loop' controls 'while' loop statements where the condition is a
     plain 'True', and can thus be changed to simple loops.
   * 'loop_for_while' controls simple loop statements whose first
     statement is an 'exit' (for the same loop), and which can therefore
     be turned into a 'while' loop.

   This rule can be given at most once for each subrule.

   Ex:
     check simplifiable_statements (block, null);
     search simplifiable_statements (if);

5.52.3 Tips
-----------

'loop' may seem a strange thing to check, since no Ada programmer is
supposed to write this.  However, experience shows that it is a good
indicator of code written by people who did not get proper Ada training.
Such code is certainly worth a peer review...

5.53 Statements
===============

This rule controls usage of certain Ada statements.

5.53.1 Syntax
-------------

     <control_kind> statements (<subrule> {, <subrule>};

     <subrule> ::=
        any_statement            | abort                  |
        accept                   | accept_return          |
        assignment               | asynchronous_select    |
        block                    | case                   |
        case_others              | case_others_null       |
        code                     | conditional_entry_call |
        declare_block            | delay                  |
        delay_until              | dispatching_call       |
        effective_declare_block  | entry_call             |
        entry_return             | exception_others       |
        exception_others_null    | exit                   |
        exit_expanded_name       | exit_for_loop          |
        exit_outer_loop          | exit_plain_loop        |
        exit_while_loop          | exited_extended_return |
        extended_return          | for_in_loop            |
        for_iterator_loop        | for_of_loop            |
        function_return          | goto                   |
        if                       | if_elsif               |
        inherited_procedure_call | labelled               |
        loop_return              | multiple_exits         |
        named_exit               | no_else                |
        null                     | procedure_return       |
        raise                    | raise_locally_handled  |
        raise_nonpublic          | raise_standard         |
        redispatching_call       | reraise                |
        requeue                  | selective_accept       |
        simple_block             | simple_loop            |
        terminate                | timed_entry_call       |
        unconditional_exit       | unnamed_block          |
        unnamed_exit             | unnamed_loop_exited    |
        unnamed_for_loop         | unnamed_multiple_loop  |
        unnamed_simple_block     | unnamed_simple_loop    |
        unnamed_while_loop       | untyped_for            |
        while_loop

5.53.2 Action
-------------

Subrules that are Ada keywords control the corresponding Ada statements.
The meaning of other subrules is as follows:
   * 'any_statement' controls all statements.  This is of course not
     intended to forbid all statements in a program (!), but _counting_
     all statements can be quite useful.
   * 'accept_return' controls return statements that return from an
     'accept' statement, 'entry_return' controls return statements that
     return from a (protected) entry body, and 'procedure_return'
     controls return statements that return from a procedure.
     'loop_return' controls return statements (including extended return
     statements) that appear inside a 'loop' statement.
   * 'assignment' controls all assignment statements.
   * 'asynchronous_select' controls the 'select' ...  'then abort'
     statement.  'conditional_entry_call' controls the 'select' ...
     'else' statement.  'timed_entry_call' controls the 'select' ...
     'or delay' statement.  'selective_accept' controls the regular
     'select' statement.
   * 'block' controls all block statements, while 'unnamed_block'
     controls blocks without a name, 'declare_block' controls blocks
     with an explicit 'declare' (even if the declarative part is empty),
     and 'effective_declare_block' controls blocks with a declarative
     part that includes anything else than 'use' clauses and pragmas.
     'simple_block' controls block statements that have no declarative
     part (or an empty declarative part) and no exception handlers, and
     'unnamed_simple_block' does the same, but only for blocks without a
     name.
   * 'case' controls all 'case' statements.
   * 'case_others' controls any 'when others' path in a 'case'
     statement, while 'case_others_null' controls only 'when others'
     paths in a 'case' statement that contain only 'null' statements.
   * 'code' controls code statements.
   * 'delay' controls only relative 'delay' statements, while
     'delay_until' controls absolute 'delay until' statements.
   * 'dispatching_call' controls all dispatching calls.  Note that this
     subrule controls dispatching procedure calls as well as dispatching
     function calls, although the latter is technically an expression
     and not a statement.  'redispatching_call' does the same, but only
     for dispatching calls that are (directly or indirectly) inside a
     primitive operation of a tagged type.
   * 'entry_call' controls all entry call statements, including those
     that are part of a conditional or timed entry call statement.
   * 'exit' controls all exit statements, while 'exit_for_loop',
     'exit_while_loop', and 'exit_plain_loop' control 'exit' statements
     that terminate 'for' loops, 'while' loops, and plain (neither 'for'
     nor 'while') loops, respectively.  'unconditional_exit' controls
     'exit' statements without a 'when' condition.  'multiple_exits'
     controls loop that have more than one 'exit' statement.
     'unnamed_loop_exited' controls exit statements that terminate an
     unnamed loop.  'exit_outer_loop' controls 'exit' statements that
     exit from an outer loop (i.e.  not the innermost one).
     'exit_expanded_name' controls named 'exit' statements where the
     name is given as an expanded name.
   * 'exception_others' controls any 'when others' exception handler,
     while 'exception_others_null' controls only 'when others' exception
     handlers that contain only 'null' statements.
   * 'extended_return' controls extended return statements (i.e.  the
     Ada 2005 construct "'return V : T do ... end return'").
     'exited_extended_return' controls extended return statements that
     can be left without actually returning due to an exit or goto
     statement within their sequence of statements.
   * 'for_loop' controls all 'for' loops, while 'for_in_loop' controls
     only the traditional form of 'for' loop ('for I in range loop'),
     'for_iterator_loop' controls the iterator form ('for I in Iterator
     loop'), and 'for_of_loop' controls the components form ('for V of
     ... loop') (the three latter forms are not available with the old
     gnat version of AdaControl).
   * 'function_return' controls return statements (including extended
     return statements) from functions.  Obviously, return statements
     cannot be forbidden in functions; this keyword controls that there
     is only one return statement in the body of functions, and at most
     one return statement in each exception handler of the exception
     part of functions.
   * 'if' controls all 'if' statements.
   * 'if_elsif' controls 'if' statements that have at least one 'elsif'.
   * 'inherited_procedure_call' controls calls to procedures that have
     been inherited by a derived type and not redefined.
   * 'labelled' controls statements with a label (true statement labels,
     not block and loop names).
   * 'named_exit' controls 'exit' statements with a loop name.
   * 'no_else' controls 'if' statements that have no 'else' path.
   * 'null' controls all 'null' statements.
   * 'raise' controls all 'raise' statements.
   * 'reraise' controls 'raise' statements in exception handlers that
     reraise the same exception, and calls to the
     'Ada.Exceptions.Reraise_Occurrence' procedure.
   * 'raise_standard' controls 'raise' statements that raise one of the
     predefined exceptions (those declared in package 'Standard').
     'raise_nonpublic' controls statements that raise exceptions that
     are neither predefined nor defined in the visible part of a package
     which is the enclosing library unit of the statement.
     'raise_locally_handled' controls statements that raise an exception
     which is handled by a handler in the same subprogram body as the
     statement.

     Note that for these subrules, the exception can be raised either by
     a 'raise' statement, or by a call to
     'Ada.Exceptions.Raise_Exception' where the raised exception is
     statically determinable.
   * 'simple_loop' controls simple loops, i.e.  those that are neither
     'while' nor 'for' loops.
   * 'unnamed_exit' controls 'exit' statements without a loop name that
     exits from a named loop.
   * 'unnamed_for_loop', 'unnamed_simple_loop', and 'unnamed_while_loop'
     control loops of the given kind that are not named.
   * 'unnamed_multiple_loop' controls nested loops that are not named
     (i.e.  under this rule, only loops that contain no inner loop, and
     are not nested in another loop, are allowed not to be named).  The
     kind of loop (plain, 'for', 'while') is not considered.
   * 'untyped_for' controls 'for' loops that use a range without an
     explicitely named type (i.e.  'for I in 1..10 loop').  Using a
     ''Range' attribute is OK.
   * 'while_loop' controls all 'while' loops.

   Ex:
     search statements (delay);
     check  statements (goto, abort);
     check  statements (case_others_null, exception_others_null);

5.53.3 Tips
-----------

It may seem strange to control things like 'if' or 'case' statements,
since no coding standard would prohibit their use.  However, this may be
useful, especially with "count", for statistical purposes, like
measuring the ratio of 'if' to 'case' statements.

   The plain "raise" subrule controls the 'raise' statement, and only
this one.  If you want to check all places where exceptions can be
raised, use also the "entities" rule like this:
     "all raise": check statements (raise),
                  check entities   (Ada.Exceptions.Raise_Exception,
                                    Ada.Exceptions.Reraise_Occurrence);

   Other subrules of the "raise" family are more about which kind of
exception is being raised, and therefore control also exceptions raised
by calling the procedures from 'Ada.Exceptions'.

   "inherited_procedure_call" controls only procedure calls.  For
function calls, see rule *note Expressions::.

5.54 Style
==========

This rules controls usage of various "general" Ada coding style.

5.54.1 Syntax
-------------

     <control_kind> style;
     <control_kind> style (casing_attribute,  <casing_kw> {,<casing_kw>});
     <control_kind> style (casing_identifier, <casing_kw> {,<casing_kw>});
     <control_kind> style (casing_keyword,    <casing_kw> {,<casing_kw>});
     <control_kind> style (casing_pragma,     <casing_kw> {,<casing_kw>});
     <control_kind> style (compound_statement);
     <control_kind> style (default_in);
     <control_kind> style (exposed_literal, <type_kw>, {, <value_place>});
     <control_kind> style (formal_parameter_order {, <mode list>});
     <control_kind> style (multiple_elements {,<element_kw>});
     <control_kind> style (negative_condition);
     <control_kind> style (no_closing_name [, <max_lines>]);
     <control_kind> style (numeric_literal, [not] <base> [, <block_size>]);
     <control_kind> style (parameter_order {, <mode list>});
     <control_kind> style (renamed_entity);

     <casing_kw>   ::= uppercase | lowercase | titlecase | original
     <element_kw>  ::= [flexible] clause | declaration | statement |
                       handler | begin | end  | then | when |
                       else    | is    | loop | do   | keywords
     <mode_list>   ::= <mode> {| <mode>}
     <mode>        ::= in   | defaulted_in | access   | in_out  | out |
                       type | procedure    | function | package
     <type_kw>     ::= integer | real | character | string
     <value_place> ::= <value> | <place>
     <value>       ::= [max] <integer number> | <real number> | "<pattern>"
     <place>       ::= constant    | exponent | index | number | pragma |
                       repr_clause | var_init | type

5.54.2 Action
-------------

The first parameter specifies which style aspect is to be checked:

   * "casing_attribute", "casing_keyword", "casing_identifier", and
     "casing_pragma" control that attributes (respectively keywords,
     identifiers, or pragmas) use the appropriate casing.  "original"
     (which is allowed only for identifiers) means that identifiers must
     use the same casing as in their declaration.

     If more than one <casing_kw> is given, it means that any of them is
     allowed.
   * "compound_statement" controls that compound statements span at
     least a minimum number of lines: 3 for 'if' statements, 'loop'
     statements, block statements, and 'accept' statements with a body;
     4 for 'case' statements, selective 'accept' statements, and timed
     entry call statements; and 5 for conditional entry call statements
     and asynchronous select statements.
   * "default_in" controls subprograms, entries and generics
     declarations that omit an explicit 'in' mode for a parameter.
     Access parameters are not reported, since an an explicit 'in' is
     not allowed in that case.
   * "exposed_literal" controls the usage of literals (aka "magic
     values"), that appear outside of allowed places.  The second
     parameter tells to which kind of literals the rule applies.  The
     (optional) indicated values that follow are allowed at any place;
     for integers, a single value can be preceded by "max", to indicate
     that all literals whose (absolute) value is less or equal are
     allowed; for strings, the values are regular expressions.  *Note
     Syntax of regular expressions::.  Commonly allowed values are 0 and
     1 for integer literals, 1.0 and 0.0 for real literals and "^$" (the
     empty string) for string literals.  At most 20 values of each kind
     may be specified.  In addition, one or several <place> keyword can
     be used to specify constructs where any literal is allowed:
     "declaration" stands for any declaration, "constant" for constant
     declarations, "exponent" for the right parameter of an
     exponentiation (i.e.  '"**"') function call, "index" for array
     indexing, "number" for named number declarations, "pragma" for
     pragma arguments, "repr_clause" for representation clauses, "type"
     for type (and subtype) declarations, and "var_init" for the
     initialization expression of variable declarations.  If no <place>
     is given, it is taken as 'number, constant', i.e.  any literal is
     allowed in named numbers and constant declarations.
   * "multiple_elements" controls clauses, declarations, statements, and
     handlers that do not start on a line of their own (i.e.  when there
     are more than one of these on the same line).  Similarly, 'begin',
     'end', 'then' and 'when' are required to be on a line of their own,
     together with the possible keyword or identifier attached to them
     and the semi-colon.  In addition, the 'is', 'loop' or 'do' that
     terminates the first part of some declarations or statements is
     required to be on the same line as the begining of the element, or
     on a line of its own.

     Extra parameters specify which kind of element to check; if not
     specified, all kind of elements are controlled.  "keywords" is a
     shorthand for specifying all keywords.  If "flexible" is specified
     in front of "clause" (not allowed otherwise), it allows a 'use'
     clause to be on the same line as a 'with' clause, provided all
     packages named in the 'use' clause are also named in the preceding
     'with' clause.
   * "negative_condition" controls "if" statements with an "else" part
     and no "elsif", where the condition starts with a 'not', and should
     therefore preferably be expressed positively.
   * "no_closing_name" controls declarations, like package or
     subprograms, that allow (but do not require) repeating the name at
     the end of the declaration, and where the closing name is omitted
     (which is considered bad style in general).  However, it can be
     acceptable to allow the omission of closing names for very short
     constructs; therefore this rule has an optional parameter
     specifying the maximum number of lines of a construct for which
     omitting the closing name is allowed.  This rule can be given only
     once for each of check, search and count.  This way, it is possible
     to have a length considered a warning (search), and one considered
     an error (check).  Of course, this makes sense only if the length
     for search is less than the one for check.  If no length is
     specified, all occurrences of missing closing names are signaled.
   * "numeric_literal" controls the presentation of numeric literals,
     depending on the base (wich, as required by Ada rules, must be in
     the range 2..16).  If "not <base>" is specified as the second
     parameter, the given base may not be used for based literals.
     Otherwise, there must be a third (integer) parameter to specify the
     size of blocks of digits for that base, i.e.  there must be an
     underscore character to separate digits every <block_size>
     position.  Typically, <block_size> is 3 for base 10, 4 for base 2,
     etc.
   * "parameter_order" and "formal_parameter_order" control the order of
     the declarations of parameters or generic formal parameters,
     respectively.  Each parameter of the rule consists in one or
     several of the "mode" keywords, and describes, in order, which kind
     of parameter is allowed.  All modes not specified explicitely are
     allowed after the ones that are specified.  See examples below.

     If no parameter is given, the order for regular parameters is "in"
     or "access" first, then "in_out", then "out", then "defaulted_in".
     The order for formal_parameters is "type" first, then "in"
     "defaulted_in" and "access", then "in_out", then "procedure" and
     "function", then "package".
   * "renamed_entity" controls occurrences of identifiers within the
     scope of a renaming declaration for them; i.e.  it enforces that
     when an entity has been renamed, the original name should not be
     used anymore.

   Ex:
     search style (no_closing_name);
     search style (no_closing_name, 5);
     check style (casing_identifier, original);
     check style (default_in);
     check style (numeric_literal, 10, 3);
     check style (exposed_literal, integer, 0, 1);
     check style (exposed_literal, real, 0.0, 1.0);

      -- in parameters (with or without default) and access
      -- parameters must be first, then in out parameters, then
      -- out parameters. In parameters are allowed last if they
      -- have defaults.
     check style (parameter_order,
                    in | defaulted_in | access,
                    in_out,
                    out
                    defaulted_in);

      -- For generics, formal objects must come first, then formal
      -- types, then formal subprograms, then formal package:
     check style (formal_parameter_order,
                    in | in_out,
                    type,
                    procedure | function,
                    package);


   Without parameter, the rule will control all style aspects with
parameter values that correspond to the most commonly used cases, i.e.
it is equivalent to the following:
     style (no_closing_name);
     style (casing_attribute, titlecase);
     style (casing_keyword, lowercase);
     style (casing_identifier, original);
     style (casing_pragma, titlecase);
     style (default_in);
     style (negative_condition)
     style (multiple_elements)
     style (literal, 10, 3);
     style (exposed_literal, integer, 0, 1)
     style (exposed_literal, real, 0.0, 1.0);

5.54.3 Tips
-----------

For the "Casing_Identifier" subrule, if the value is "original",
subprogram and parameter names from the body are checked against those
from the specification (if any).  This is what the user would expect,
although strictly speaking it is not a usage of the name.

   Note that operators always follow the casing rule for keywords, even
for calls that use the infix notation (i.e.  in '"and"(A, B)').

   Having more than one allowed casing is useful if for example you want
to require Titlecase, but accept that the original casing be used (maybe
because your editor or pretty-printer forces it).

   For the "Exposed_Literal" subrule, negative values can be specified
as being allowed; negative numbers are handled as if they were literals.
This is what the casual user would expect, but to the language lawyer,
"-1" is not a negative literal, it is a unary minus operator applied to
the positive value "1".

   "compound_statement" was a simplistic way of finding badly laid-out
statements, at a time when "multiple_elements" did not control the end
or intermediate parts of declarations and statements.  It is of little
use now that "multiple_elements" has been enhanced.

5.54.4 Limitations
------------------

If a predefined operator or an attribute is renamed, the
"renamed_entity" subrule cannot check that the original entity is not
used in the scope of the renaming.  Such cases are detected by the rule
"uncheckable".  *Note Uncheckable::.

5.55 Terminating_Tasks
======================

This rule controls tasks that can terminate.

5.55.1 Syntax
-------------

     <control_kind> terminating_tasks

5.55.2 Action
-------------

A task is considered a terminating task if its last statement is not an
unconditional loop, or this if this loop is exited.  It is also
considered terminating if it contains a selective accept with a
'terminate' alternative.

   Since this rule has no parameters, it can be given only once.

   Ex:
     check terminating_tasks;

5.55.3 Tips
-----------

There is still one case where a task terminates, which is not reported
by this rule: when a task is aborted.  This is intended, since there are
cases (like mode changes) where a logically non-terminating task is
aborted.

   If aborts are also to be reported, use the rule "statements (abort)".
*Note Statements::.

5.56 Type_Initial_Values
========================

This rule controls that a special constant is declared together with
each type, for example to serve as a default initial value.

5.56.1 Syntax
-------------

     <control_kind> type_initial_values [("<pattern>")];

5.56.2 Action
-------------

This rule controls types that do not feature an initialization constant
declared in the same declarative part as the type.  If no <pattern> is
given, any constant is considered an initialization constant for its
type; otherwise, only constants whose name matches the given pattern are
considered initialization constants.

   Ex:
     check type_initial_values ("^C_Init_");
   The above example will ensure that every declared type features a
constant of the type whose name starts with "C_Init_".

5.57 Type_Usage
===============

This rule controls usage of indicated types, either individually or by
category.

5.57.1 Syntax
-------------

     <control_kind> type_usage (<attribute>, <category> {, <aspect>}]);
     <control_kind> type_usage (index, <entity>|<category> {, <aspect>}]);
     <category> ::= ()  | access    | array | delta  | digits |
                    mod | protected | range | record | tagged | task
     <aspect>   ::= [not] representation | pack | size | component_size

5.57.2 Action
-------------

If the first parameter is an attribute (a name starting with a simple
quote), the rule controls all occurrences of the attribute where the
prefix designates a type belonging to the <category> given as second
parameter.

   If the first parameter is "index", the rule controls all array types
that have an index of the type given by <entity>, or belonging to the
<category> given as second parameter.  As usual, the whole syntax for
entities is allowed for <entity>.  *Note Specifying an Ada entity
name::.

   For both subrules, if one or several <aspect> are given, only types
featuring (or not featuring if "not" is given) the provided aspects are
controlled.

   The meaning of <category> is:
   * "()": The type is an enumerated type.
   * "access": The type is an access type.
   * "array": The type is an array type.
   * "delta": The type is a fixed point type (it is not currently
     possible to distinguish ordinary fixed point types from decimal
     fixed point types).
   * "digits": The type is a floating point type.
   * "mod": The type is a modular type.
   * "protected": The type is a protected type.
   * "range": The type is a signed integer type.
   * "record": The type is an (untagged) record type.
   * "tagged": The type is a tagged type (including type extensions).
   * "task": The type is a task type.

   The meaning of <aspect> is:
   * "representation": the type has an enumeration representation clause
     or a record representation clause.
   * "pack": the type is the target of a pack 'pragma'.
   * "size" and "component_size": the type has the corresponding
     attribute specified.

   Ex:
     -- Don't use the 'Pos attribute for enumerated types with a representation
     check type_usage ('Pos, (), representation);

     -- Don't use modular type for array indexes
     check type_usage (index, mod);

5.57.3 Tips
-----------

The subrule "index" controls the use of a type as an index at any
position and irrespectively of the number of indices of the array.  To
control a precise pattern of types used as indices, use the rule
"array_declarations".  *Note Array_Declarations::.

   The subrule that uses attribute names does not allow an <entity>.  To
control occurrences of an attribute on a precise type, use the rule
"entities".  *Note Entities::.

5.58 Uncheckable
================

This rules controls cases where it is not possible to guarantee the
accuracy of checks performed by AdaControl, and where manual inspection
may be required.

5.58.1 Syntax
-------------

     <control_kind> uncheckable [(<subrule> [,<subrule>])];
     <subrule> ::= false_positive | false_negative | missing_unit

5.58.2 Action
-------------

If the keyword "missing_unit" is given, this rule controls missing
units, i.e.  units given on the command line that are not found (and
therefore not controlled) will result in an usual error message.

   Otherwise, this rule controls constructs that are not static and
prevent other rules from being fully reliable.  This rule is special,
since it really affects the way other rules behave when they encounter a
statically uncheckable construct.  Therefore, if a label is given, the
message will include the label as usual, with an indication of the rule
that triggered the message; if no label is given, the message will
include the name of the rule that detected the uncheckable construct,
not "uncheckable" itself.

   If the keyword "false_negative" is given, the rule will control
constructs that could result in false negatives, i.e.  possible
violations that would go undected, while if the keyword "false_positive"
is given, it will control constructs that could result in false
positives, i.e.  error messages when the rule is not really violated.
If no keyword is given, both occurrences are controlled.

   As far as statistics are concerned (see *note Control kinds and
report messages::), "uncheckable" messages from rules are counted under
the corresponding rule's statistics (like other messages), but there
will be also a count of all "uncheckable" messages under the rule
"UNCHECKABLE", and also subtotals corresponding to the number of
"uncheckables" for each rule.

   This rule can be given only once for each of value of the parameters.

   Ex:
     check uncheckable (false_negative);
     search uncheckable (false_positive);
     check uncheckable (missing_unit);

5.58.3 Tips
-----------

This rule is especially important when AdaControl is used in safety
critical software, since it will detect constructs that could escape
verification.  Such constructs should be either disallowed, or require
manual inspection.  On the other hand, in casual software, it may lead
to many messages, since for example dispatching calls are uncheckable
with many rules.

5.58.4 Limitation
-----------------

With "missing_unit", the message does not include a reference to a
source location, since there is no place in the source which can be
considered as the origin of the error.  If you run AdaControl from GPS,
there will always be a separate category ("Uncheckable") in the
locations window, under which the message will appear, with a file name
of "none".  Don't try to click on the error message, since GPS will find
no file named "none"!

5.59 Unit_Pattern
=================

This rule controls various usage patterns of program units and elements
declared in them.

5.59.1 Syntax
-------------

     <control_kind> unit_pattern (Single_Tagged_Type);
     <control_kind> unit_pattern (Tagged_Type_Hierarchy);
     <control_kind> unit_pattern (Context_Clauses_Order {, <clause_list>});
     <control_kind> unit_pattern (Declarations_Order, <target>,
                                  {, <declaration_list>});

     <clause_list>      ::= <clause> {| <clause>}
     <clause>           ::= with | use | use_type | pragma
     <target>           ::= package_public | package_private | package_body |
                            subprogram
     <declaration_list> ::= <declaration> {| <declaration>}
     <declaration>      ::= use                   | use_type                 |
                            use_all_type          | number                   |
                            constant              | variable                 |
                            private_type          | full_type                |
                            subtype               | subprogram_spec          |
                            package_spec          | generic_subprogram_spec  |
                            generic_package_spec  | task_spec                |
                            protected_spec        | subprogram_body          |
                            package_body          | generic_subprogram_body  |
                            generic_package_body  | task_body                |
                            protected_body        | object_renaming          |
                            subprogram_renaming   | package_renaming         |
                            exception_renaming    | subprogram_instantiation |
                            package_instantiation | exception                |
                            others

5.59.2 Action
-------------

The checked pattern depends on the given subrule:
   * "single_tagged_type" controls that at most one tagged type is
     declared in any package.
   * "tagged_type_hierarchy" controls that tagged types follow packages
     hierarchy, i.e.  that the parent of a type extension (derivation of
     a tagged type) is declared in the parent unit of the one that
     declared the derivation.
   * "context_clauses_order" controls the order of context clauses (and
     pragmas) given on top of the unit.  Each parameter of the rule
     consists in one or several of the <clause> keywords, and describes,
     in order, which kind of clause is allowed.  Note that "use_type"
     covers only the regular 'use type' clause, specify also
     "use_all_type" to include the Ada 2012 'use all type' clause as
     well.  Note that all <clause>s not specified explicitely have no
     place, and thus are not allowed at all.
   * "declarations_order" controls the order of declarations (and use
     clauses) given in various parts, depending on the second parameter:
        * "package_public" controls elements in the visible part of a
          package specification;
        * "package_private" controls elements in the private part of a
          package specification;
        * "package_body" controls elements in the body of a package;
        * "subprogram" controls elements in the body of subprograms
          (procedures and functions) and entries.
     Each parameter of the rule consists in one or several of the
     <declaration> keywords, and describes, in order, which kind of
     declaration is allowed.  Note that all <declaration>s not specified
     explicitely have no place, and thus are not allowed at all, unless
     "others" is given as the last parameter, in which case it covers
     all elements not part of any of the preceding parameters.  See
     example below.
   Ex:
     check unit_pattern (single_tagged_type);
     check unit_pattern (tagged_type_hierarchy);

     -- All with clauses must come first, then use and use type clauses
     -- (freely mixed), then pragmas
     check unit_pattern (context_clauses_order,
                            with,
                            use | use_type | use_all_type,
                            pragma);

     -- In the public part of a package, declare constants and named numbers
     -- first,then private types, then any of regular types, constants, and
     -- variables, then subprograms specifications (including generics and
     -- instantiations), then anything else:
     check unit_pattern (declarations_order, package_public,
        number | constant,
        private_type,
        full_type | constant | variable,
        subprogram_spec | generic_subprogram_spec | subprogram_instantiation,
        others);

5.59.3 Tips
-----------

For "context_clauses_order" and "declarations_order", elements given as
part of the same parameter (i.e.  with a vertical bar between them) can
be freely mixed, then followed by any of the elements of the next
parameter, etc.  An element may appear several times in different
parameters.  If the last parameter is "others", any element not
mentionned at all is allowed after the ones for which you specify an
order; this way, it is possible to specify an order for just some
elements, and then don't care for the rest.

   Expression functions and null procedures are classified as
"subprogram_spec" unless they are the completion of an explicit
specification, in which case they are classified as "subprogram_body".

   If you don't want a declaration to appear at all, you can also use
the rule "declarations".  *Note Declarations::.

5.60 Units
==========

This rule controls that all necessary units, and only those, are
processed by AdaControl.

5.60.1 Syntax
-------------

     <control_kind> units [(<subrule> [,<subrule>])];
     <subrule> ::= unreferenced | unchecked

5.60.2 Action
-------------

If the keyword 'unreferenced' is given, the rule controls compilation
units that are part of the set of analyzed units, but withed by no other
unit.  If the keyword 'unchecked' is given, the rule controls
compilation units that are withed by other unit(s), but not part of the
set of controlled units (except standard units).

   This rule can only be given once for each of the subrules.

   Ex:
     check units (unchecked);
     search units (unreferenced);

5.60.3 Tip
----------

The main program will appear as unreferenced, since it is normally part
of the controlled units, and not withed by any other unit.  As usual,
the corresponding message can be disabled by putting the comment:
     --## rule line off units
   on the main program.

5.61 Unnecessary_Use_Clause
===========================

This rule controls 'use' clauses that do not serve any purpose.

5.61.1 Syntax
-------------

     <control_kind> unnecessary_use_clause [(<subrule> {,<subrule>})];
     <subrule> ::= unused | qualified | operator | nested | movable

5.61.2 Action
-------------

The rule controls 'use' clauses that can safely be removed, moved, or
changed to a 'use type' clause.  This happens in the following cases:
   * "unused": a 'use' clause is given, but no element from the
     corresponding package is mentionned in its scope.  The message
     starts with "unused:".

     In this case, the 'use' clause can safely be removed.
   * "qualified": a 'use' clause is given, but all elements from the
     corresponding package are refered to using a qualified name (i.e.
     prefixed by the name of the package).  The message starts with "all
     uses qualified:".

     In this case, the 'use' clause can safely be removed, but you may
     want to keep it for documentation purposes, since the package is
     actually used within this scope.
   * "operator": a 'use' clause is given, but the only elements that do
     not use a qualified name are operators.  The message starts with
     "only used for operators:".

     In this case, and except for some pathological cases (definition of
     operators that are not primitive operations of the corresponding
     type), the 'use' clause can be replaced by one or several 'use
     type' clause(s).
   * "nested": a 'use' clause is given within the scope of an enclosing
     'use' clause for the same package.  The message tells the location
     of the other 'use' clause.

     If you also have a message that the outer 'use' clause is
     unnecessary, this means that all references to the package appear
     inside the inner 'use' clauses, and that the outer one can be
     removed.  If not, you can either remove the inner 'use' clauses, or
     remove the outer one and add more local 'use' clauses where
     necessary.
   * "movable": a 'use' clause is given in a package specification, but
     all uses are from the corresponding body.  The message starts with
     "use clause can be moved to body:".

     In this case, the 'use' clause can safely be moved to the body,
     unless it appears in a library package, and there are unqualified
     references to its elements from child units.

   If no parameter is given, all cases are controlled, otherwise only
cases corresponding to the specified keyword(s) are controlled.  This
rule can be given only once for each value of the parameters.

   Ex:
     remove: search unnecessary_use_clause (unused);
     use_type: check unnecessary_use_clause (operator);

5.61.3 Tip
----------

This rule checks only usage of 'use' clauses.  The rule
"reduceable_scope" can be used to check that 'use' clauses do not span
unnecessarily to wide a scope.  *Note Reduceable_Scope::.

5.61.4 Limitations
------------------

There are some rare cases where the rule may signal that a 'use' clause
is not necessary, where it actually is.  There is no risk associated to
this since if you remove the 'use' clause, the program will not compile.

   The first one comes from a limitation of the ASIS standard: if the
only use of the 'use' clause is for making the "root" definition of a
dispatching call visible.

   The second one comes from a limitation in ASIS-for-Gnat.  This
happens when the only use of the 'use' clause is for making an
implicitely declared operation (an operation which is declared by the
compiler as part of a type derivation) visible, and when:
   * the operation is the target of a renaming declaration;
   * or the operation is passed as an actual to a generic instantiation;
   * or all operands of the operation are universal (i.e.  untyped).

   Since these problems come from intrinsic limitations of ASIS, there
is nothing we can do about it.  When this happens, you can disable the
unnecessary_use_clause rule using the line (or block) disabling feature.
*Note Disabling controls::.  Note that for the third alternative of the
second case, you can also qualify one of the parameters, so it is not
universal any more.

5.62 Unsafe_Elaboration
=======================

This rule controls (generic) packages that may be subject to elaboration
order dependencies.

5.62.1 Syntax
-------------

     <control_kind> unsafe_elaboration;

5.62.2 Action
-------------

The rule controls library packages (or generic packages) whose
elaboration calls or instantiates elements from other units (except
language defined units) that are not subject to a 'pragma' 'Elaborate'
or 'Elaborate_All'.  The elaboration of such packages may depend on
elaboration order.

   Since this rule has no parameters, it can be given only once.

   Ex:
     check unsafe_elaboration;

5.62.3 Tips
-----------

If the package contains tasks, they are considered as being part of the
elaboration code of the package, since tasks could be started by the
elaboration of the package.  This is somehow pessimistic in the unlikely
case where a package would contain a local task type (whose
specification is not part of the package specification) and no task
object of that type is declared.  Anyway, this could create only false
positives, therefore there is no risk associated to it.

5.63 Unsafe_Paired_Calls
========================

This rule controls usage of calls to operations that are normally paired
(like P/V operations) and do not follow a "safe" coding pattern.

5.63.1 Syntax
-------------

     <control_kind> unsafe_paired_calls
        (<opening procedure>, <closing procedure> [, <lock type>]);
     <opening procedure> ::= <entity>
     <closing procedure> ::= <entity>
     <lock type>         ::= <entity>

5.63.2 Action
-------------

The following explanations are given in terms of "locks" since this is
the primary use of this rule, however the rule can be used for any calls
that need to be properly paired.

   The rule can deal with three different kinds of locks:
   * abstract state machines: There is no "lock" object, locking is done
     directly inside the procedures.  The <lock type> parameter of the
     rule must not be provided in that case.
   * object abstract data types: The procedure operates on an object
     (generally of a private type) representing the "lock" object,
     passed as an "in out" parameter.  The third parameter must be the
     corresponding type, and the rule will control that all matching
     pairs of calls refer statically to the same variable.
   * reference abstract data types: The procedure operates on a
     reference that designates the "lock" object, passed as an
     "in"parameter.  The third parameter must be the corresponding type,
     which must be discrete or access, and the rule will control that
     all matching pairs of calls refer statically to the same value (for
     discrete types) or to the same constant (for access types).

   As usual, the whole syntax for entities is allowed for <entity>.
*Note Specifying an Ada entity name::.

   The "safe" coding pattern is defined as follows:
   * A call to the first procedure is the first statement of a handled
     sequence of statements;
   * A call to the second procedure is the last statement of the same
     handled sequence of statements;
   * Corresponding calls of a pair use the appropriate value for the
     "lock" parameter (if any), as explained above.
   * There is no other call to either operation in the statements of the
     handled sequence of statements, except in nested blocks or accept
     statements; calls in such inner statements shall not reference the
     same values or variables as outer ones.
   * There is an exception handler for "others" in the handled sequence
     of statements.
   * Every exception handler of the handled sequence of statements
     includes a single call to the second operation, using the
     appropriate value or variable for the lock parameter.

   Typically, the "safe" pattern corresponds to the following
structures:
     -- Abstract state machine
     begin
        P;
        -- Do something
        V;
     exception
        when others =>
           V;
           -- handle exception
     end;

     -- Object abstract data type
     declare
        My_Lock : Lock_Type;
     begin
        P (My_Lock);
        -- Do something
        V (My_Lock);
     exception
        when others =>
           V (My_Lock);
           -- handle exception
     end;

     -- Reference abstract data type
     declare
        Lock_Ptr : constant Lock_Access := Get_Lock;
     begin
        P (Lock_Ptr);
        -- Do something
        V (Lock_Ptr);
     exception
        when others =>
           V (Lock_Ptr);
           -- handle exception
     end;

   Ex:
     check unsafe_paired_calls (Semaphore.P, Semaphore.V, Semaphore.Lock_Access);

5.63.3 Tips
-----------

If the <Lock type> parameter is provided, both procedures must have a
single parameter of the given type, it must not correspond to an "out"
parameter, and if it corresponds to an "in" parameter, the type must be
discrete or access.

   This rule can be specified several times, and it is possible to have
the same procedure belonging to several rules.  For example, if you have
a 'Mask_Interrupt' procedure that should be matched by either
'Unmask_Interrupt' or 'General_Reset' (all declared in package
'IT_Driver'), you can specify:
     check unsafe_paired_calls (IT_Driver.Mask_Interrupt,
                                IT_Driver.Unmask_Interrupt);
     check unsafe_paired_calls (IT_Driver.Mask_Interrupt,
                                IT_Driver.General_Reset);

   Normally, the legality of a rule is checked when the rules file is
parsed, and execution does not start if there is any error.  However,
the legality of the provided type can be checked only during the
analysis.  If the type is incorrect for some reason, a proper error
message is issued and execution stops immediately.

5.63.4 Limitation
-----------------

Due to a weakness of the ASIS standard, dispatching calls are not
considered.  Especially, this means that the <Lock type> cannot be
class-wide.  Such calls are detected by the rule "uncheckable".  *Note
Uncheckable::.

   Due to a size limitation of internal data structures, this rule can
be specified at most 32 times.

5.64 Unsafe_Unchecked_Conversion
================================

This rule controls unchecked conversions between types which are not
statically known to have identical sizes.

5.64.1 Syntax
-------------

     <control_kind> unsafe_unchecked_conversion

5.64.2 Action
-------------

This rule controls instances of 'Unchecked_Conversion' between types
where the following conditions are not met:
   * A size clause has been specified for both types
   * Both sizes are equal

   Moreover, a special message is given if any of the types is a
class-wide type (certainly a very questionable construct!).

   Ex:
     check unsafe_unchecked_conversion

5.64.3 Limitation
-----------------

There are cases where a size clause is given for a type, but AdaControl
is unable to evaluate it.  This happens especially if the size clause
refers to a size attribute of a predefined type, like:
     for T'Size use Integer'size;

   This can lead to false positives (i.e.  detection of instantiations
of 'Unchecked_Conversion' that are actually OK). Such cases are detected
by the rule "uncheckable".  *Note Uncheckable::.

5.65 Usage
==========

This rule controls how certain entitities (variables, constants, types,
procedures, functions, exceptions, tasks, protected objects, and
generics) are used.

5.65.1 Syntax
-------------

     <control_kind> usage
        (variable|object {,[not] <location> | read | written | initialized});
     <control_kind> usage
        (constant {,[not]  <location> | read});
     <control_kind> usage
        (type {,[not]  <location> | used});
     <control_kind> usage
        (procedure {,[not]  <location> | called | accessed});
     <control_kind> usage
        (function {,[not]  <location> | called | accessed});
     <control_kind> usage
        (exception {,[not]  <location> | raised | handled});
     <control_kind> usage
        (task {,[not]  <location> | called | aborted});
     <control_kind> usage
        (protected {,[not]  <location> | called});
     <control_kind> usage
        (generic {,[not]  <location> | instantiated});
     <control_kind> usage
        (all {,[not]  <location>});

     <location> ::= from_visible | from_private | from_spec

5.65.2 Action
-------------

The first parameter defines the class of entities to be controlled.
"object" stands for both "constant" and "variable", "type" stands for
both types and subtypes, and "all" stands for all classes.

   If only one parameter is given, usage of all entities belonging to
the indicated class are reported .  Otherwise, other parameter(s) are
keyword that restrict the kind of usage being controlled.

   "[not] from_visible", "[not] from_private", and "[not] from_spec"
restrict entities being checked to those that appear (or not) in
(generic) package specifications, in the visible part, in the private
part, or in any part, respectively.  "accessed" (available for
subprograms only) restricts entities being checked to those that appear
as the prefix of a ''Access' or ''Address' attribute.  Other keywords
carry their obvious meaning, and are allowed only where appropriate.
The rule will output the information only for objects that match all the
conditions given.  A combination of parameters can be given only once
for each of "check", "search", and "count".

   The report includes the kind of unit that declares the entity (normal
unit, instantiation, or generic unit), the part where it is declared
(visible or private) if it is declared in a (generic) package, and
whether the entity is known to be initialized, read, written, raised,
handled, called, or aborted, depending on the entity's class.  Some
combinations give an extra useful message (for example, a variable which
is initialized and read but not written will produce a "could be
declared constant" message).

   Variables of an access type and variables of an array type whose
components are of an access type (or arrays of an access type, etc.)
are always considered initialized, since they are initialized to 'null'
by the compiler.

   Variables that cannot be assigned to (i.e.  variables of an array
type with some null dimension, or variables of a discrete type whose
range includes no values) are specially recognized as
"pseudo-constants": there is no message that they are not written to
(since it is not possible), but there is an indication that they are
pseudo-constants.

   The subrules "procedure" and "function" check only regular
subprograms, not protected ones.  On the other hand, the subrule
"protected" controls all calls to any protected subprogram or entry.

   Exceptions raised by calling 'Raise_Exception' and tasks aborted by
calling 'Abort_Task' are properly recognized as exceptions being raised
and tasks being aborted, respectively.

   In the case of entities declared in generic packages, the rule will
report on usage of the entities for each instantiation, as well as on
global usage for the generic itself.  Usage for an instantiation will
include usage in the generic itself (i.e.  if the generic writes to a
variable, the variable will be marked as "written" for each
instantiation).  Usage for the generic itself is the union of all usages
in all instantiations (i.e., if a variable from any instantiation is
written to, the variable from the generic will be marked as written).
Therefore, if the rule reports that a variable in a generic package can
be declared constant, it means that no instance of this variable from
any instantiation is being written to.  But bear in mind that this can
be trusted only if all units from the program are analyzed.  *Note
limitation::.

   Note that usage of entities whose declaration is not processed (like,
typically, elements declared in standard packages like 'Ada.Text_IO'),
is not reported.  For the same reason, it is not possible to control
usage of predefined operators (since they have no declaration).

   Ex:
     -- No variable in package spec; check usage otherwise
     Package_Variable: check usage  (variable, from_spec);
     Constantable    : search usage (variable, not from_spec, read,
                                               initialized, not written);
     Uninitialized   : check usage  (variable, not from_spec, read,
                                               not initialized, not written);
     Removable       : search usage (object,   not from_spec, not read);

     -- Check exceptions that are never raised
     -- generics that are never instantiated
     -- and protected objects that are never called
     check usage (exception, not raised);
     check usage (generic, not instantiated);
     check usage (protected, not called);

     -- Find how many tasks are declared, and report those
     -- that may be aborted
     count usage (task);
     check usage (task, aborted);

5.65.3 Tips
-----------

Constants that are never used, exceptions that are never raised or
handled, tasks that are never called, etc.  are suspicious.  Moreover,
some useful compiler warnings (like those about variables that should be
declared constants) are not output for variables declared in library
packages, and even in some other contexts (at least with GNAT). This
rule can check these kind of things, project wide.

   Some of these checks make sense only for entities declared in package
specifications; for example, variables are often discouraged in package
specifications, or need at least some extra control.  That's why it can
be useful to restrict some checks to package specifications.

   Note that an unspecified parameter in a rule stands for two rules
(positive and negative form of the missing parameter).  I.e.:
     search usage (variable, from_spec, read, written);
   is the same as:
     search usage (variable, from_spec, read, written, initialized);
     search usage (variable, from_spec, read, written, not initialized);
   Therefore, the following example will complain on the second line
that the rule has already been given for this combination of parameters:
     search usage (variable, from_spec, read, written);
     search usage (variable, from_spec, read, written, not initialized);

   Note that the notion of constants for this rule includes named
numbers.

5.65.4 Limitations
------------------

The report of this rule is output at the end of the run, and is
meaningful only for the units that have been processed; i.e., if it
reports "variable not read", it should be understood as "not read by the
units given".  In order to have meaningful results, it is therefore
advisable to use this rule on the complete closure of the program.

   An exception can be raised by passing its ''Identity' to a procedure
that will in turn call 'Raise_Exception' (and similarly for
'Abort_Task').  These cases are not statically determinable, and
therefore not recognized by AdaControl.  However, these cases can be
identified by searching the use of the ''Identity' attribute with the
following rule:
     check entity (all 'Identity);

   If an object is the prefix of a ''Access', ''Unchecked_Access', or
''Address' attribute, it can be used through the access (or address)
value in ways that are not statically analyzable.  The same happens if
objects are targets of dynamic renamings.  Such cases are detected by
the rule "uncheckable".  *Note Uncheckable::.

   Due to a weakness of the ASIS standard, it is not possible to know
the mode (in, out) of variables used as parameters of dispatching calls.
Such variables are considered to be read and written at the point of the
call, therefore possibly creating false positives (which is safer than
false negatives).  Use of such constructs is detected by the rule
"uncheckable".  *Note Uncheckable::.

5.66 Use_Clauses
================

This rule controls usage of 'use' clauses.

5.66.1 Syntax
-------------

     <control_kind> use_clauses
        [([<subrule>,] <package name> {, <package name>})];
     <subrule> ::= package | local | global | type | type_local | type_global

5.66.2 Action
-------------

The rule controls every 'use' or 'use type' clause, except those that
name one of the mentioned packages/types.  It is therefore possible to
allow 'use' or 'use type' clauses just for certain packages/types.

   If the keyword "package" is given (or no keyword at all), all package
'use' clauses are controlled.  If the keyword "global" is given, only
'use' clauses that appear in context clauses (i.e.  together with the
'with' clauses) are controlled; if the keyword "local" is given, only
'use' clauses that appear as declarations are controlled.

   If the keyword "type" is given, all 'use type' clauses are
controlled.  If the keyword "type_global" is given, only 'use type'
clauses that appear in context clauses (i.e.  together with the 'with'
clauses) are controlled; if the keyword "type_local" is given, only 'use
type' clauses that appear as declarations are controlled.

   This rule can be given at most once for each of check, search and
count.  This way, it is possible to have a level considered a warning
(search), and one considered an error (check).

   Ex:
     -- Global use clauses are disallowed, local ones only for IO:
     check use_clauses (global);
     check use_clauses (local, Ada.Text_IO, Ada.Wide_Text_IO);

     -- No use type in context clauses, count types that are "use type"'d
     check (type_global);
     count (type);

5.67 With_Clauses
=================

This rule controls 'with' clauses that should be removed or moved to a
better place.

5.67.1 Syntax
-------------

     <control_kind> with_clauses [(<subrule> [, <subrule>])];
     <subrule> ::= multiple_names | reduceable | inherited

5.67.2 Action
-------------

The parameters are subrule keywords that determine which kind of control
is performed:
   * 'multiple_names' controls any 'with' clause that mentions more than
     one unit name.
   * 'reduceable' reports:
        * Redundant 'with' clauses, i.e.  clauses given more than once
          for the same unit.  This includes the case where the same
          'with' clause is given in a specification and the
          corresponding body, and the case of renamings of a same unit
          (i.e.  'Text_IO' and 'Ada.Text_IO').  Note that giving a
          'with' clause in a unit, and repeating it in a child unit (or
          subunit) is not considered redundant.
        * Unused 'with' clauses, i.e.  when nothing from the withed unit
          is referenced in the corresponding unit.  The rule signals
          when a withed unit is not used in a unit, but used in one or
          more of its subunits.  If an unused 'with' clause is given on
          a package specification, the message reminds that it migh be
          useful for child units.
        * Moveable 'with' clauses, i.e.  when the withed unit is not
          used in the specification, but only in the body, and should be
          moved to the body, or when the withed unit is only used in the
          private part, and could be replaced by a 'private' 'with'.
   * 'inherited' controls child units and subunits that reference a unit
     which is not directly withed, i.e.  when withed only from a parent
     (or enclosing) unit.  Although Ada rules imply that a 'with' clause
     carries on to child units and subunits, it can be considered better
     practice to ensure that every compilation unit withes directly the
     units it needs.

   Each of the keywords can be given at most once.  If no keyword is
given, both 'reduceable' and 'inherited' are assumed.

   Ex:
     check with_clauses (multiple_names, reduceable);
     search with_clauses (inherited);

5.67.3 Variables
----------------

Variable       Values      Default Effect
Check_Private_Withoff/on   on      if you are working in pure Ada 95, you
                                   may not want messages that a 'with'
                                   can be replaced with a 'private'
                                   'with'.  Setting this variable to off
                                   disables these messages.
Ignore_Use_Clauseoff/on    on      Normally, package names appearing in
                                   use clauses are not considered.
                                   Setting this variable to off will
                                   result in them being treated like any
                                   other identifier (see tip below).

5.67.4 Tips
-----------

A 'with' clause can safely be removed if it is unused, and no child unit
(or subunit) reports that the unit is inherited.

   Normally, use of a package name in a 'use' clause is not considered a
usage of the package; clearly, the 'with' clause can (and should) be
removed (or moved) if the only use of the package is in 'use' clauses
(removing or moving the 'use' clauses by the same token).  However, some
programming rules may require placing 'use' clauses in certain places,
forcing the corresponding 'with' clause.  Set the variable
'Ignore_Use_Clause' to 'off' to make sure that a 'use' clause does mark
the 'with' clause as necessary.

6 Examples of using AdaControl for common programming rules
***********************************************************

In most projects, there are programming rules that define the way a
program should be written.  AdaControl performs controls, i.e.  it finds
occurrences of certain kinds of constructs.  In this chapter, we give
examples of commonly found programming rules, and how the corresponding
controls can be written.

6.1 Migrating from Gnatcheck
============================

The file 'gnatcheck.aru' in directory 'rules' gives the AdaControl
equivalents of rules checked by Gnatcheck.  This version of AdaControl
covers most of Gnatcheck rules.  For rules where Gnatcheck requires a
parameter, the AdaControl rule is given for the default value, or with
an example value.  Small differences in semantics are indicated by a
comment that starts with "Difference:".

   This file is not intended to be used directly, but as an example on
how to convert Gnatcheck rules into AdaControl rules.  Note that in many
cases, AdaControl is much more general than Gnatcheck.  The file follows
as strictly as possible the rules as defined by Gnatcheck, but if you
are migrating from Gnatcheck to AdaControl, you may want to use the more
powerful forms provided by AdaControl.

6.2 Rules files provided with AdaControl
========================================

The 'rules' directory provides also rules files that can be sourced to
enforce some commonly encountered general rules.


Identifiers from Standard shall not be redefined

   Use file 'no_standard_entity.aru'.


Identifiers from System shall not be redefined

   Use file 'no_system_entity.aru'.


Predefined IO packages shall not be used

   Use file 'no_io.aru'.


Standard package XXX shall not be used

   File 'no_standard_unit.aru' controls usage of all standard packages.
Comment out those that you do want to allow.


Obsolescent features shall not be used

   Use file 'no_obsolescent_features.aru'.  Not all obsolescent features
are controlled, but most of them (those that are most worth checking)
are.


Gnat specific attributes shall not be used

   Use file 'no_gnat_attribute.aru'


Features from annex X shall not be used

   Use file 'no_annex_X.aru'.


The Ravenscar profile shall be enforced

   Use file 'ravenscar.aru'.

   Note that not all of the restrictions of the Ravenscar profile are
currently controlled, but many are, and we expect later releases of
AdaControl to increase the number of controlled features.  In some cases
(like "Detect_Blocking"), AdaControl does a better job than the profile,
since it can detect statically situations that the profile only requires
to be detected at run-time.  The rule file is also slightly more
restrictive than the profile; for example, the restriction
"no_task_allocation" only disallows task allocators, while this rule
file controls the declaration of access types on tasks.


NASA coding guidelines shall be enforced

   Use file 'nasa.aru'.  This file is an example of how to convert
guidelines (available from
<http://fsw.gsfc.nasa.gov/gds/code_standards_ada.pdf>) into an
AdaControl rules file.


Ada 83 unit names shall not be used (i.e.  use 'Ada.Text_IO', not
'Text_IO')

   Use file 'no_83_unit_name.aru'.


New reserved words of Ada 2005/2012 shall not be used

   Use file 'reserved_2005.aru'.  (the file name mentions only 2005, but
it checks also for 2012 - after all, there is only one extra reserved
word).


Measurements for the SQALE method

   AdaControl can provide measurements required by the SQALE quality
measurement method.  The corresponding file is 'SQALE.aru'.

   For information about the SQALE method, please refer to J-P Rosen's
paper at <http://www.adalog.fr/publicat/sqale.pdf>

6.3 Automatically checkable rules
=================================

Below are examples of rules that can be directly checked by AdaControl.


Goto statement shall not be used
     check statements (goto);


Functions shall not have 'out' or 'in out' parameters (Ada 2012)
     check parameter_declarations (out_parameters,    max 0, function);
     check parameter_declarations (in_out_parameters, max 0, function);


Short circuit forms should be preferred over corresponding logical
operators
     Use_Short_Circuit: search expressions (and, or);


Aggregates should be used for full assignments to structured variables,
unless it is a record with a single component
     check multiple_assignments (groupable, given 2, ratio 100);


All loops that contain exit statements must be named, and the name must
be given in the exit statement
     check statements (unnamed_loop_exited);
     check statements (unnamed_exit);


All type names must start with "T_"
     check naming_convention (type, "^T_");


All program units must repeat their name after the "end"
     check style (no_closing_name);


Pragma Suppress is not allowed
     check pragmas (suppress);


Ada tasking must not be used
     check declarations (task);


"=" and "/=" shall not be used between real types
     check expressions (real_equality);


All tasks must provide an exception handler that calls "Failure" in the
case of an unhandled exception
     check exception_propagation (task);
     check silent_exceptions (failure);


Unchecked_Conversion shall not be used
     check entities (ada.unchecked_conversion);


No global variable shall be declared in the visible part of a package
specification
     check usage (variable, from_spec);


Predefined numeric types of the language shall not be used
     check entities (standard.Integer,
                     standard.short_integer,
                     standard.long_integer,
                     standard.Float,
                     standard.short_float,
                     standard.long_float);


Access to subprograms shall not be used
     check declarations (access_to_sp);


Abort statements shall not be used
     check statements (abort);


There shall be only one instantiation of
Ada.Numerics.Generic_Elementary_Functions for each floating point type
     -- Put a --##RULE LINE OFF GEF
     -- for the one which is allowed
     GEF: check Instantiations (Ada.Numerics.Generic_Elementary_Functions);


A local item shall not hide an outer one with the same name
     check Local_Hiding;


There shall be no IOs in exception handlers
     check entity_inside_exception (ada.Text_IO.put, ada.Text_IO.put_line,
                                    ada.Text_IO.get, ada.Text_IO.get_line);
   Note that this checks for all overloaded procedures, but only those
dealing with characters and strings (those defined directly within
Ada.Text_IO). If the names "get" and "put" are not used for anything
else than IOs, a more general form can be given as:
     check entity_inside_exception (all get,      all put,
                                    all get_line, all put_line);
   This will check that no entity with the corresponding names appear in
exception handlers.


Exceptions shall not be used
     No_Exception: check declarations (exception, handlers);
     No_Exception: check statements (raise);
     No_Exception: check entities (Ada.Exceptions);

   This will check that no exception is declared, no exception handler
is provided, and no exception is raised, not even through the services
of the package 'Ada.Exceptions'.


No procedure exported to C shall propagate exceptions
     check exception_propagation (interface, C);


There shall be no Unchecked_Conversion to or from Address
     check instantiations (ada.unchecked_conversion, system.address);
     check instantiations (ada.unchecked_conversion, <>, system.address);


There shall be no use clause except for Text_IO
     check use_clauses(ada.text_IO);


Use explicit list of values in case statements rather than "when
others"if the "when others" would cover less than 10 values
     check Case_Statement(min_others_span, 10);


If a block is more than 20 lines long, it must be named
     check Max_Size(unnamed_block, 20);


Exceptions shall not be handled except by main program
     check declaration (handlers)
   This check will be disabled for the exception handler of the main
program.


Each unit has a header starting with a fixed format, and must contain at
least 10 lines of comments
     check header_comments (model, "header.txt");
     check header_comments (minimum, 10);
   The file 'header.txt' contains the required header (as regexps),
like:
     ^--*{50}$
     ^-- This is a header$

6.4 Rules that need manual inspection
=====================================

Below are examples of rules that require manual inspection, but where
AdaControl can be used to identify suspicious areas.


All usages of the 'ADDRESS attribute shall be justified and documented
     search entities (all 'address);


Specifying an address for a variable shall be restricted to hardware
interfacing
     search representation_clauses(address);


There shall be no memory leakage
     search Allocators;
   This rule identifies all allocations, and thus can be used to check
that all allocated elements are properly deallocated.

Appendix A Specifying an Ada entity name
****************************************

A.1 General syntax
==================

Many rules can take Ada entities as parameters.  Each time a rule uses
the category <entity>, it refers to an Ada entity that can be specified
with the following syntax:
     <entity> ::= <full_name> | "all" <simple_name> | "all" <attribute>
   '<full_name>' is the full name of the Ada entity, using normal Ada
dot notation (with some extensions, see below).  Full name means that
you give the full expanded name, starting from a compilation unit.  This
name must be the actual full name, i.e.  it must not include any
renaming (otherwise the name will not be recognized).  For example, the
usual 'Put_Line' must be given as 'Ada.Text_IO.Put_Line', not as
'Text_IO.Put_Line'.  Predefined elements ('Integer', 'Constraint_Error')
must be given in the form 'Standard.Integer' or
'Standard.Constraint_Error', since they are logically declared in the
package 'Standard'.

   '<simple_name>' is a single identifier, possibly followed by
overloading information.  No qualification is allowed.

   '<Attribute>' is an attribute name, including the quote.  No
overloading information is allowed.

   '<full_name>' designates a single entity or several overloaded
entities declared in the same place (as identified by the prefix), while
'all <simple_name>' designates all identifiers with the given name in
the program, irrespectively of where they appear.  'all <Attribute>'
designates all occurrences of the given attribute, irrespectively of
what the attribute applies to.

   A utility is provided with AdaControl to help you find the full name
of an entity.  *Note pfni::.  If you are using GPS with AdaControl
plug-ins, it can be accessed directly from the contextual menu.  *Note
Contextual menu::.

A.2 Overloaded names
====================

In Ada, names can be overloaded.  This means that you can have several
procedures 'P' in package ' Pack', if they differ by the types of the
parameters.  If you just give the name 'Pack.P' as the <entity>, the
corresponding rule will be applied to all elements named 'P' from
package 'Pack'.  If you want to distinguish between overloaded names,
you can specify a profile after the element's name.  A profile has the
syntax:

     "{" [ ["access"] <type-name>
          { ";" ["access"] <type-name> } ]
          ["return" <type-name>] "}"

   You must specify the type name, even if the <entity> declaration uses
a subtype of the type; this is because Ada uses types for overloading
resolution, not subtypes.  Anonymous access parameters are specified by
putting 'access' in front of the type name.  An overloaded name for a
procedure without parameters uses just a pair of empty brackets.  If the
subprogram is a function, you must provide the 'return <type-name>' part
for the return type of the function.  The types must also be given as a
unique name, i.e.  including the full path: if the type is 'T' declared
in package 'Pack', you must specify it as 'Pack.T'.  As a convenience,
the 'Standard.' is optional for predefined types, so you can write
'Standard.Integer' as 'Integer'.  There is no ambiguity, since a type is
always declared within some construct.  Note that omitting 'Standard'
works only for types that are part of the profile used to distinguish
between overloaded Ada entities but that the Ada entity name must always
contain Standard if it is a predefined element.

   Overloaded names can be also be used with the 'all <simple_name>'
form of the <entity>.  In this case, the rule will be applied to all
names that are subprograms with the given identifier and matching the
given profile, irrespectively of where they appear.

   Note that if you use an overloaded name, all overloadable names that
are part of the <entity>, including those of the profile, must use the
overloaded syntax.  For example, given the following program
     procedure P is
        procedure Q (I : Integer) is
           ...
        end Q;
        procedure Q (F : Float) is
           ...
        end Q;
     begin
        ...
     end P;

   If you want to distinguish between the two procedures 'Q', you must
specify them as 'P{}.Q{Integer}' and 'P{}.Q{Float}' (note the 'P{}'
which specifies an overloaded name for a procedure 'P' without
parameters).

   The names of entities which can not be overloaded (like package,
exception, ...) must not be suffixed by braces (e.g.
'Ada.Text_IO.Put_Line{Standard.String}').

A.3 Enumeration literals
========================

Following normal Ada rules, an enumeration literal is considered a
parameterless function.  If you want to distinguish between overloaded
enumeration literals, you can use overloaded names for them.  For
example, given:
     package Pack is
        type T1 is (A, B);
        type T2 is (B, C);
     end Pack;

   Ada entities names are:
   * 'Pack.B{return Pack.T1}'
   * 'Pack.B{return Pack.T2}'

A.4 Operators
=============

AdaControl handles operators (i.e.  functions like '"+"') correctly.  Of
course, you must specify such operations using normal Ada syntax: if you
define the integer type 'T' in package 'Pack', an overloaded name for
the addition would be 'Pack."+"{Pack.T; Pack.T return Pack.T}'.

A.5 Attributes
==============

It is also possible to designate attributes of entities, using the
normal notation (i.e.  'Standard.Integer'First').  If the name of an
attribute which is a function appears in a name that uses the overloaded
syntax, it is not necessary (and actually not allowed) to provide its
profile, since there is no possible ambiguity in that case.  For
example, given:

     procedure P (I : Integer) is
        type T is range 1 .. 10;
     begin
        ...
     end P;

   You can designate the ''Image' attribute for type 'T' as
'P{Standard.Integer}.T'Image' (the profile of the ''Image' function is
not given, as would be necessary for a normal function).

   To designate all occurrences of an attribute, use 'all' in front of
the attribute.  To designate only occurrences of an attribute whose
prefix is a (sub) type (but any type or subtype), give it as 'type'Attr'
(i.e.  the keyword "type" is put in front of the quote).

   'all' may be used in place of an attribute name to mean "any
attribute".  See examples below.

     check entities (all 'Image);      -- Find all occurrences of 'Image
     check entities (all type'Length); -- Find all occurrences of 'Length
                                       -- applied to a type

     check entities (Standard.Integer'all); -- Find all attributes applied
                                            -- to type Integer
     Check entities (all type'all);         -- Find all attributes applied
                                            -- to a type
     check entities (all 'all);             -- Find all attributes

A.6 Anonymous constructs and extended return statements
=======================================================

There is a special case for elements that are defined (directly or
indirectly) within unnamed loops or block statements.  Everything
happens as if the unnamed construct was named '_anonymous_'.  Therefore
if you have the following program:
     procedure P is
     begin
        for I in 1..10 loop
           declare
              J : Integer;
           begin
              ...
           end;
        end loop;
     end P;
   You can refer to 'I' as 'P._anonymous_.I', and to 'J' as
'P._anonymous_._anonymous_.J'.

   Similarly, an extended return statement is considered "named"
'return'.  Therefore if you have the following program:
     function F return Integer is
        I : Integer;
     begin
        return I : Integer do
           ...
        end return;
     end F;
   You can refer to the 'I' declared in 'F' as 'F.I', and to the return
object 'I' as 'F.return.I'.

A.7 Record and protected types components
=========================================

You can designate the name of a record or protected type component (a
"field" name), but to identify it uniquely, you must precede its name by
the name of the type.  This is a small extension to Ada syntax, but it
is the simplest and most natural way to deal with this case.  For
example, given:
     procedure P is
        type T is
           record
              Name : Integer;
           end record;
        ...

   The Ada entity name is 'P.T.Name'.

A.8 Formals of access to subprogram types
=========================================

Similarly, you can designate the formal of an access to subprogram type
by prefixing it by the access type.  For example, given:
     procedure P is
        type T is access procedure (X : Integer);
        ...

   The Ada entity name of the formal is 'P.T.X'.

A.9 Limitation
==============

Due to a limitation of ASIS for GNAT, it is not possible to specify a
profile with predefined operators; predefined operators without a
profile work normally.
     -- This will not recognize "<" on Standard.Integer:
     check entities (Standard."<"{Standard.Integer,
                                  Standard.Integer
                                  return Standard.Boolean});

     -- This will correctly recognize all predefined "<":
     check entities (Standard."<");

Appendix B Syntax of regular expressions
****************************************

The following syntax gives the complete definition of regular
expressions, as used by several rules.  It is taken from the
specification of the package 'gnat.regpat', where additional information
is available.

     regexp ::= expr
            ::= ^ expr               -- anchor at the beginning of string
            ::= expr $               -- anchor at the end of string

     expr   ::= term
            ::= term | term          -- alternation (term or term ...)

     term   ::= item
            ::= item item ...        -- concatenation (item then item)

     item   ::= elmt                 -- match elmt
            ::= elmt *               -- zero or more elmt's
            ::= elmt +               -- one or more elmt's
            ::= elmt ?               -- matches elmt or nothing
            ::= elmt *?              -- zero or more times, minimum number
            ::= elmt +?              -- one or more times, minimum number
            ::= elmt ??              -- zero or one time, minimum number
            ::= elmt { num }         -- matches elmt exactly num times
            ::= elmt { num , }       -- matches elmt at least num times
            ::= elmt { num , num2 }  -- matches between num and num2 times
            ::= elmt { num }?        -- matches elmt exactly num times
            ::= elmt { num , }?      -- matches elmt at least num times
                                        non-greedy version
            ::= elmt { num , num2 }? -- matches between num and num2 times
                                        non-greedy version

     elmt   ::= nchr                 -- matches given character
            ::= [range range ...]    -- matches any character listed
            ::= [^ range range ...]  -- matches any character not listed
            ::= .                    -- matches any single character
                                     -- except newlines
            ::= ( expr )             -- parens used for grouping
            ::= \ num                -- reference to num-th parenthesis

     range  ::= char - char          -- matches chars in given range
            ::= nchr
            ::= [: posix :]          -- any character in the POSIX range
            ::= [:^ posix :]         -- not in the POSIX range

     posix  ::= alnum                -- alphanumeric characters
            ::= alpha                -- alphabetic characters
            ::= ascii                -- ascii characters (0 .. 127)
            ::= cntrl                -- control chars (0..31, 127..159)
            ::= digit                -- digits ('0' .. '9')
            ::= graph                -- graphic chars (32..126, 160..255)
            ::= lower                -- lower case characters
            ::= print                -- printable characters (32..127)
            ::= punct                -- printable, except alphanumeric
            ::= space                -- space characters
            ::= upper                -- upper case characters
            ::= word                 -- alphanumeric characters
            ::= xdigit               -- hexadecimal chars (0..9, a..f)

     char   ::= any character, including special characters
                ASCII.NUL is not supported.

     nchr   ::= any character except \()[].*+?^ or \char to match char
                \n means a newline (ASCII.LF)
                \t means a tab (ASCII.HT)
                \r means a return (ASCII.CR)
                \b matches the empty string at the beginning or end of a
                   word. A word is defined as a set of alphanumerical
                   characters (see \w below).
                \B matches the empty string only when *not* at the
                   beginning or end of a word.
                \d matches any digit character ([0-9])
                \D matches any non digit character ([^0-9])
                \s matches any white space character. This is equivalent
                   to [ \t\n\r\f\v]  (tab, form-feed, vertical-tab,...
                \S matches any non-white space character.
                \w matches any alphanumeric character or underscore.
                   This include accented letters, as defined in the
                   package Ada.Characters.Handling.
                \W matches any non-alphanumeric character.
                \A match the empty string only at the beginning of the
                   string, whatever flags are used for Compile (the
                   behavior of ^ can change, see Regexp_Flags below).
                \G match the empty string only at the end of the
                   string, whatever flags are used for Compile (the
                   behavior of $ can change, see Regexp_Flags below).
     ...    ::= is used to indication repetition (one or more terms)

   Embedded newlines are not matched by the ^ operator.  It is possible
to retrieve the substring matched a parenthesis expression.  Although
the depth of parenthesis is not limited in the regexp, only the first 9
substrings can be retrieved.

   The operators '*', '+', '?'  and '{}' always match the longest
possible substring.  They all have a non-greedy version (with an extra ?
after the operator), which matches the shortest possible substring.

   For instance:
      regexp="<.*>"   string="<h1>title</h1>"   matches="<h1>title</h1>"
      regexp="<.*?>"  string="<h1>title</h1>"   matches="<h1>"

   '{' and '}' are only considered as special characters if they appear
in a substring that looks exactly like '{n}', '{n,m}' or '{n,}', where n
and m are digits.  No space is allowed.  In other contexts, the curly
braces will simply be treated as normal characters.

   Note that if you compiled AdaControl with the
'String_Matching_Portable' package, only basic wildcards are available,
i.e.  only "*" and "?"  are supported, where "*" matches any string of
character and "?"  matches a single character.

Appendix C Non upward-compatible changes
****************************************

This chapter is intended to users of a previous version of AdaControl,
who want to migrate rule files to the latest version.  Although we
understand the burden of non upward-compatible changes, we consider that
making AdaControl more powerful and easier to use is sometimes more
important than strict compatibility.  Moreover, in most cases the
changes are very straightforward and can be done easily by hand, or with
scripts if many files are involved.

C.1 Migrating from 1.16r11
==========================

C.1.1 Declarations, Entities, Instantiations
--------------------------------------------

These rules use the concept of "location" to restrict the places where
some constructs are controlled.  It is now possible to specify "not" in
front of a location keyword.  As a consequence, the keyword "nested" has
been removed, as it was the same thing as "not library".  In short,
change:
     check declarations (nested procedure);
   to:
     check declarations (not library procedure);

C.2 Migrating from 1.15r5
=========================

C.2.1 Array_Declarations
------------------------

The extension of aspects to more rules required a slight change in the
syntax of the "component" subrule: the keywords "packed", "sized", and
"component_sized" have been changed to "pack", "size", and
"component_size", respectively.

C.2.2 Multiple_Assignments
--------------------------

Due to new functionalities, and expecting more in the future, the rule
has been renamed to "Assignments".

C.2.3 No_Operator_Usage
-----------------------

The syntax has been changed, due to the introduction of "indexing".
Moreover, the rule was not consistent, in that the result of "none" was
affected by the presence or absence of "logical" (without "logical",
"none" included all types, while with it, it counted only those not
counted with "logical").  If you want that exact same behaviour (which
might not be desirable), change:
     -- (1)
     check no_operator_usage (none);

     -- (2)
     check no_operator_usage (logical);

     -- (3)
     check no_operator_usage (none, logical)
                          -- or no parameters
   to:
     -- (1)
     check no_operator_usage(ignore indexing, ignore logical);
                          -- or no parameters

     -- (2)
     check no_operator_usage (logical);

     -- (3)
     check no_operator_usage (not logical),
     check no_operator_usage (logical);

C.2.4 Object_Declarations
-------------------------

Due to the necessity of avoiding a syntactic ambiguity in the new
subrule "type", the keyword "all" is no more allowed in the syntax for
the subrule "min_integer_span" (specifying neither "variable" or
"constant" still means the subrule applies to both, as before).  Change:
     count object_declarations (min_integer_span, all 8);
   to:
     count object_declarations (min_integer_span, 8);

C.2.5 Statements
----------------

The subrule "exit" was documented as controlling all exit statements,
but it did not report exits from 'for' and 'while' loops if
"exit_for_loop" (respectively "exit_while_loop") was also specified.  It
now behaves as documented, i.e.  it controls all 'exit' statements.

   Note that if you want separate messages for each kind of loop, the
new rule "exit_plain_loop" controls exit from plain loops.

C.2.6 Style
-----------

The subrule "positional_association" is now a rule of its own,
"positional_associations".  The order of parameters is different, due to
various subrules of the new rule.  Typically, change:
     check style (parameter_association, call, 1);
   to:
     check parameter_associations (all, 1, call);

   Note that the new rule distinguishes between regular array aggregates
and aggregates used for enumeration representation clauses.

   Modes of the subrules "parameter_order" and "formal_parameter_order"
are now separated by "|".  With the previous syntax, forgetting a comma
was changing the meaning of the rule without introducing a syntax error.
Typically, change:
     check style (parameter_order, in defaulted_in, out in_out);
   to:
     check style (parameter_order, in | defaulted_in, out | in_out);

C.3 Migrating from 1.14r9
=========================

C.3.1 Local_Hiding
------------------

Due to the introduction of extra parameters for allowed patterns, it is
no more possible to specify the rule several times in the same command.
Change:
     check local_hiding (strict, overloading);
   to:
     check local_hiding (strict);
     check local_hiding (overloading);
   The special subrule "overloading_short" has been replaced by a rule
variable to choose the report format.  Change:
     check local_hiding (overloading_short);
   to:
     set local_hiding.overloading_report compact;
     check local_hiding (overloading);

C.3.2 Max_Nesting
-----------------

The value given is now the nesting level (consistent with the rule
name), no more the maximum depth.  This is more natural (Max_Nesting(1)
means that the construct can be nested once), but it is one less than in
previous versions.  For example, change:
     check Max_Nesting (5);
   to:
     check Max_Nesting (4);

C.3.3 Parameter_Declarations
----------------------------

The subrules have been generalized, using the same syntax for bounds as
other rules.  Change:
     check parameter_declarations (min_parameters, 1);
     check parameter_declarations (max_parameters, 5);
     check parameter_declarations (max_defaulted_parameters, 3);
   to:
     check parameter_declarations (all_parameters, min 1, max 5);
     check parameter_declarations (defaulted_parameters, max 3);

C.4 Migrating from 1.11r4
=========================

C.4.1 Expressions
-----------------

The subrule 'Real_Equality' does not control user-defined equality
operators any more.  This is intended to be more of an improvement than
an incompatibily.

C.4.2 Special_Comments
----------------------

Since the number of subrules is growing, and do not only address
'special" comments, this rule has been renamed to "comments".

C.5 Migrating from 1.10r10
==========================

C.5.1 GPS integration
---------------------

Due to a bug/feature of the GPS interface, if a units file was
specified, it did not reappear later in the corresponding box of the
Switch/AdaControl dialog.  This has been fixed, but you must reenter the
units file name in the dialog.

C.5.2 Representation_Clauses
----------------------------

The introduction of categories made some subrules syntactically
ambiguous or redundant.  In consequence, the subrules "derived_record",
"extension_record", and "tagged_record" have been removed, and the
subrules "record", "incomplete_record", and "non_contiguous_record" have
been renamed as "layout", "incomplete_layout", and
"non_contiguous_layout" respectively.  Change:
     check representation_clause (derived_record);
     check representation_clause (extension_record);
     check representation_clause (tagged_record);
     check representation_clause (record);
     check representation_clause (incomplete_record);
     check representation_clause (non_contiguous_record);
   to:
     check representation_clause (new layout);
     check representation_clause (extension layout);
     check representation_clause (tagged layout);
     check representation_clause (layout);
     check representation_clause (incomplete_layout);
     check representation_clause (non_contiguous_layout);

C.6 Migrating from 1.9r4
========================

C.6.1 Array_Declarations
------------------------

The subrule "Max_Length" has been changed to "Length", with the
possibility to specify both min and max values.  Change:
     check array_declarations (max_length, 100);
   to:
     check array_declarations (length, max 100);

C.6.2 Declarations
------------------

The subrule names "initialized_record_field",
"uninitialized_record_field", "initialized_protected_field", and
"uninitialized_protected_field" have been changed to
"initialized_record_component", "uninitialized_record_component",
"initialized_protected_component", and
"uninitialized_protected_component", respectively, to be more consistent
with official Ada terminology.  Change:
     check declarations (initialized_record_field,
                         uninitialized_record_field,
                         initialized_protected_field,
                         uninitialized_protected_field);
   to:
     check declarations (initialized_record_component,
                         uninitialized_record_component,
                         initialized_protected_component,
                         uninitialized_protected_component);

   The subrule "aliased" has been split into "aliased_constant" and
"aliased_variable".  The old rule controlled both at the same time, but
did not control aliased components (there are now other subrules to that
effect).  Change:
     check declarations (aliased);
   to:
     check declarations (aliased_constant, aliased_variable);

C.6.3 Default_Parameter
-----------------------

The <place> is no more allowed to be "all", because it was ambiguous
with the "all <name>" syntax of <entity>.  If you used "all", duplicate
the control with "calls" and "instantiations".  Change:
     My_label : check default_parameter (all, ...);
   to:
     My_label : check default_parameter (calls, ...),
                check default_parameter (instantiations, ...);

C.6.4 Improper_Initialization
-----------------------------

By default, variables declared directly within (generic) package
specifications and bodies are no more checked.  To get the previous
behaviour, add the "package" modifier.  Change:
     check improper_initialization (variable);
   to:
     check improper_initialization (package variable);

C.7 Migrating from 1.8r8
========================

C.7.1 CSV(X) format
-------------------

If the output format is CSV or CSVX, the file name, line number and
column number are generated as three different spreadsheet columns,
instead of forming a single message.  This makes it easier to use a
spreadsheet program for per-file statistics.

C.7.2 Default_Parameter
-----------------------

Due to the introduction of the "positional" keyword, "not used" is now
spelled "not_used".  Change:
     check default_parameter (proc, param, not used);
   to:
     check default_parameter (proc, param, not_used);

C.7.3 Other_Dependencies
------------------------

This rule has been changed into a subrule of the (new) rule
"Dependencies".  Change:
     check Other_Dependencies (pack1, pack2);
   to:
     check Dependencies (others, pack1, pack2);

C.7.4 Special_Comments
----------------------

Due to the introduction of another subrule, add "pattern" as the first
parameter to the rule.  Change:
     check Special_Comments ("TBSL");
   to:
     check Special_Comments (pattern, "TBSL");

C.7.5 Statements
----------------

The "raise" subrule now reports all occurrences of the 'raise'
statement, even if another control is applicable to the same statement.

   The "reraise" subrule now reports calls to
'Ada.Exceptions.Reraise_Occurrence'.

   The "raise_standard" subrule now reports exceptions raised by calls
to 'Ada.Exceptions.Raise_Exception'.

C.8 Migrating from 1.7r9
========================

C.8.1 Case_Statement
--------------------

This rule now allows the specification of both min and max values for
each subrule.  Subrule names have been changed accordingly.  Change:
     check Case_Statement (max_range_span, 5);
     check Case_Statement (max_values, 10);
     check Case_Statement (min_others_span, 4);
     check Case_Statement (min_paths, 6);
   to:
     check Case_Statement (range_span, max 5);
     check Case_Statement (values, max 10);
     check Case_Statement (others_span, min 4);
     check Case_Statement (paths, min 6);

C.8.2 Max_Parameters
--------------------

This rule has been changed into a subrule of the (new) rule
"Parameter_Declarations".  Change:
     check Max_Parameters (10);
   to:
     check Parameter_Declarations (Max_Parameters, 10);

C.9 Migrating from 1.6r8
========================

C.9.1 "message" command
-----------------------

The message is now syntactically a string, and must always be enclosed
in double quotes (quotes were optional in previous versions).

C.9.2 "source" command
----------------------

If a "source" command is given in a rules file, and the sourced file is
given with a relative path, it is interpreted relatively to the sourcing
file (it was interpreted relatively to the current directory
previously).  This should make "chained" sourcing easier, since the
interpretation does not depend on where the sourcing file is being
called from.

C.9.3 Control_Characters
------------------------

This rule is now called "Characters" and can process other kinds of
characters in addition to control characters.  Control characters
correspond to the "control" parameter of the rule.  Change:
     check control_characters;
   to:
     check characters (control);

C.9.4 If_For_Case
-----------------

This rule has been changed into a subrule of the (new) rule
"simplifiable_statements".  Change:
     check if_for_case;
   to:
     check simplifiable_statements (if_for_case);

C.9.5 Instantiations
--------------------

The rule does not print the number of instantiations any more, since the
same effect can be achieved with the "count" control kind.

C.9.6 Local_Instantiation
-------------------------

This rule has been removed, since its effect can now be achieved with
other rules: the rule "declarations" to check for local instantiations
of any generic, and the rule "instantiations" to check for local
instantiations of specified generics.  Change:
     R1: check Local_Instantiation;
     R2: search Local_Instantiation (Ada.Unchecked_Conversion);
   to:
     R1: check  declarations   (local instantiation);
     R2: search Instantiations (local Ada.Unchecked_Conversion);

C.9.7 Naming_Convention
-----------------------

Quotes are no more optional around patterns.

   The <location> modifier is now before the <filter_kind> (it was
before the pattern previously).  This may require splitting the rule in
two in some cases.  For example, change:
     check naming_convention (object, local "^L_", global "^G_");
   to:
     check naming_convention (local object, "^L_");
     check naming_convention (global object, "^G_");

C.9.8 No_Safe_Initialization
----------------------------

The name of this rule has been changed to "improper_initialization",
since it now controls other cases of improper initialization.

C.9.9 Special_Comments
----------------------

Quotes are no more optional around patterns.

C.9.10 Statements
-----------------

Two subrules of this rule have migrated to the new rule
"simplifiable_statements" (with slightly different names).  Change:
     check statements (unnecessary_null);
     check statements (while_true);
   to:
     check simplifiable_statements (null);
     check simplifiable_statements (loop);

C.10 Migrating from 1.5r24
==========================

C.10.1 Declarations
-------------------

The subrule "Formal_In_Out" has been renamed as
"In_Out_Generic_Parameter", for consistency with the new
"In_Out_Parameter" subrule.

   The subrules "renames" and "not_operator_renames" have been renamed
to "renaming" and "not_operator_renaming".

   As a consequence of being able to specify the location of any
construct, the subrules "nested_function_instantiation",
"nested_generic_function", "nested_generic_package",
"nested_generic_procedure", "nested_package",
"nested_package_instantiation", and "nested_procedure_instantiation"
have been removed and replaced with the corresponding general construct
(without "nested_").  You can have the same effect by specifying the
"nested" modifier in front of them.  I.e., change:
     check declarations (nested_generic_function);
   to:
     check declarations (nested generic_function);

C.10.2 Naming_Convention
------------------------

The <location> keyword is placed before the <Filter_Kind> keyword
instead of before the <Pattern>, which looks more natural.  The "Any"
keyword has been removed, since omitting the <location> keyword has the
same effect.  Change:
     check naming_convention (variable, global "^G_");
     check naming_convention (package, any "^Pack_");
   to:
     check naming_convention (global variable, "^G_");
     check naming_convention (package, "^Pack_");

C.10.3 Non_Static_Constraint
----------------------------

This rule is now called Non_Static, since it is no more restricted to
constraints.  The parameters "index" and "discriminant" have been
changed to "index_constraint" and "discriminant_constraint",
respectively.  Change:
     check non_static_constraint (index, discriminant);
   to:
     check non_static (index_constraint, discriminant_constraint);

C.10.4 Positional_Parameters
----------------------------

This rule has been renamed to 'Insufficient_Parameters', since it does
no more handle the "maximum" subrule.  Controlling positional parameters
according to their number is now done by the rule 'style
(positional_association)'.  Change:
     check positional_parameters (maximum, 3);
     check positional_parameters (insufficient, 2, Boolean);
   to:
     check style (positional_association, call, 3);
     check insufficient_parameters (2, Boolean);

C.10.5 Real_Operator
--------------------

This rule is no more a rule of its own, it is a subrule of the (new)
rule Expressions, whose name is Real_Equality.  Change:
     check Real_Operators;
   to:
     check expressions (Real_Equality);

C.10.6 Style
------------

The name of the subrule "casing" has been changed to "casing_identifier"
since the casing of attributes and pragmas can now also be checked.  The
casing style is no more optional.

   The name of the subrule "literal" has been changed to
"numeric_literal" (since characters and strings are also literals, but
are not handled by this subrule).

   The subrule "exposed_literal" now requires an extra parameter to tell
whether it applies to integer literals, real literals, character
literals or string literals.  Allowed values are provided after this
parameter, and must of course be of the appropriate type.  In short, if
you had:
     check style (exposed_literal, 0, 1, 0.0, 1.0);
   you must change it to:
     check style (exposed_literal, integer, 0, 1)
     check style (exposed_literal, real, 0.0, 1.0);

   The "aggregate" parameter of the subrule "positional_association" has
been split into "array_aggregate" and "record_aggregate".  For example,
change:
     check style (positional_association, aggregate);
   into:
     check style (positional_association, record_aggregate, array_aggregate);

C.11 Migrating from 1.4r20
==========================

C.11.1 GPS integration
----------------------

The XML file used to describe AdaControl features to GPS used to be
called 'adactl.xml'.  It is now called 'zadactl.xml', since GPS
processes its initialization files in alphabetical order.  This avoids
shuffling the menus when AdaControl support is activated.

   Make sure to remove the old 'adactl.xml' file from the GPS plug-ins
directory before installing the new version.

C.11.2 Declarations
-------------------

The parameters "access" and "access_subprogram" have been changed to
"access_type" and "access_subprogram_type", for consistency with the new
parameters.

C.11.3 Header_Comments
----------------------

A keyword has been added to specify the required number of comment
lines.  Change:
     check Header_Comments (10);
   to:
     check Header_Comments (minimum, 10);

C.11.4 No_Closing_Name
----------------------

This rule is now part of the "style" rule.  Change:
     check|search|count No_Closing_Name;
   to:
     check|search|count Style (No_Closing_Name);

C.11.5 Specification_Objects
----------------------------

This rule is now part of the "usage" rule.  Change:
     check|search|count Specification_Objects (<parameters>);
   to:
     check|search|count Usage (Object, From_Spec, <parameters>);

C.11.6 Statement
----------------

Name changed from "statement" to "statements" (added an 's'), to be
consistent with other rules.

C.11.7 When_Others_Null
-----------------------

This rule is now part of the "statements" rule.  Change:
     check|search|count When_Others_Null (case);
     check|search|count When_Others_Null (exception);
   to:
     check|search|count Statements (case_others_null);
     check|search|count Statements (exception_others_null);
