gcc/ada/opt.ads

   1 ------------------------------------------------------------------------------
   2 --                                                                          --
   3 --                         GNAT COMPILER COMPONENTS                         --
   4 --                                                                          --
   5 --                                  O P T                                   --
   6 --                                                                          --
   7 --                                 S p e c                                  --
   8 --                                                                          --
   9 --          Copyright (C) 1992-2007, Free Software Foundation, Inc.         --
  10 --                                                                          --
  11 -- GNAT is free software;  you can  redistribute it  and/or modify it under --
  12 -- terms of the  GNU General Public License as published  by the Free Soft- --
  13 -- ware  Foundation;  either version 2,  or (at your option) any later ver- --
  14 -- sion.  GNAT is distributed in the hope that it will be useful, but WITH- --
  15 -- OUT ANY WARRANTY;  without even the  implied warranty of MERCHANTABILITY --
  16 -- or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License --
  17 -- for  more details.  You should have  received  a copy of the GNU General --
  18 -- Public License  distributed with GNAT;  see file COPYING.  If not, write --
  19 -- to  the  Free Software Foundation,  51  Franklin  Street,  Fifth  Floor, --
  20 -- Boston, MA 02110-1301, USA.                                              --
  21 --                                                                          --
  22 -- As a special exception,  if other files  instantiate  generics from this --
  23 -- unit, or you link  this unit with other files  to produce an executable, --
  24 -- this  unit  does not  by itself cause  the resulting  executable  to  be --
  25 -- covered  by the  GNU  General  Public  License.  This exception does not --
  26 -- however invalidate  any other reasons why  the executable file  might be --
  27 -- covered by the  GNU Public License.                                      --
  28 --                                                                          --
  29 -- GNAT was originally developed  by the GNAT team at  New York University. --
  30 -- Extensive contributions were provided by Ada Core Technologies Inc.      --
  31 --                                                                          --
  32 ------------------------------------------------------------------------------
  33
  34 --  This package contains global flags set by the initialization routine from
  35 --  the command line and referenced throughout the compiler, the binder, or
  36 --  other GNAT tools. The comments indicate which options are used by which
  37 --  programs (GNAT, GNATBIND, GNATLINK, GNATMAKE, GPRMAKE, etc).
  38
  39 with Hostparm; use Hostparm;
  40 with Types;    use Types;
  41
  42 with System.Strings; use System.Strings;
  43 with System.WCh_Con; use System.WCh_Con;
  44
  45 package Opt is
  46
  47    ----------------------------------------------
  48    -- Settings of Modes for Current Processing --
  49    ----------------------------------------------
  50
  51    --  The following mode values represent the current state of processing.
  52    --  The values set here are the default values. Unless otherwise noted,
  53    --  the value may be reset in Switch-? with an appropropiate switch. In
  54    --  some cases, the values can also be modified by pragmas, and in the
  55    --  case of some binder variables, Gnatbind.Scan_Bind_Arg may modify
  56    --  the default values.
  57
  58    Ada_Bind_File : Boolean := True;
  59    --  GNATBIND, GNATLINK
  60    --  Set True if binder file to be generated in Ada rather than C
  61
  62    type Ada_Version_Type is (Ada_83, Ada_95, Ada_05);
  63    pragma Warnings (Off, Ada_Version_Type);
  64    --  Versions of Ada for Ada_Version below. Note that these are ordered,
  65    --  so that tests like Ada_Version >= Ada_95 are legitimate and useful.
  66    --  The Warnings_Off pragma stops warnings for Ada_Version >= Ada_05,
  67    --  which we want to allow, so that things work OK when Ada_15 is added!
  68    --  This warning is now removed, so this pragma can be removed some time???
  69
  70    Ada_Version_Default : Ada_Version_Type := Ada_05;
  71    --  GNAT
  72    --  Default Ada version if no switch given
  73
  74    Ada_Version : Ada_Version_Type := Ada_Version_Default;
  75    --  GNAT
  76    --  Current Ada version for compiler, as set by configuration pragmas,
  77    --  compiler switches, or implicitly (to Ada_Version_Runtime) when a
  78    --  predefined or internal file is compiled.
  79
  80    Ada_Version_Explicit : Ada_Version_Type := Ada_Version_Default;
  81    --  GNAT
  82    --  Like Ada_Version, but does not get set implicitly for predefined
  83    --  or internal units, so it reflects the Ada version explicitly set
  84    --  using configuration pragmas or compiler switches (or if neither
  85    --  appears, it remains set to Ada_Version_Default). This is used in
  86    --  the rare cases (notably for pragmas Preelaborate_05 and Pure_05)
  87    --  where in the run-time we want the explicit version set.
  88
  89    Ada_Version_Runtime : Ada_Version_Type := Ada_05;
  90    --  GNAT
  91    --  Ada version used to compile the runtime. Used to set Ada_Version (but
  92    --  not Ada_Version_Explicit) when compiling predefined or internal units.
  93
  94    Ada_Final_Suffix : constant String := "final";
  95    Ada_Final_Name   : String_Ptr := new String'("ada" & Ada_Final_Suffix);
  96    --  GNATBIND
  97    --  The name of the procedure that performs the finalization at the end of
  98    --  execution. This variable may be modified by Gnatbind.Scan_Bind_Arg.
  99
 100    Ada_Init_Suffix : constant String := "init";
 101    Ada_Init_Name   : String_Ptr := new String'("ada" & Ada_Init_Suffix);
 102    --  GNATBIND
 103    --  The name of the procedure that performs initialization at the start
 104    --  of execution. This variable may be modified by Gnatbind.Scan_Bind_Arg.
 105
 106    Ada_Main_Name_Suffix : constant String := "main";
 107    --  GNATBIND
 108    --  The suffix for Ada_Main_Name. Defined as a constant here so that it
 109    --  can be referenced in a uniform manner to create either the default
 110    --  value of Ada_Main_Name (declared below), or the non-default name
 111    --  set by Gnatbind.Scan_Bind_Arg.
 112
 113    Ada_Main_Name : String_Ptr := new String'("ada_" & Ada_Main_Name_Suffix);
 114    --  GNATBIND
 115    --  The name of the Ada package generated by the binder (when in Ada mode).
 116    --  This variable may be modified by Gnatbind.Scan_Bind_Arg.
 117
 118    Address_Clause_Overlay_Warnings : Boolean := True;
 119    --  GNAT
 120    --  Set False to disable address clause warnings
 121
 122    Address_Is_Private : Boolean := False;
 123    --  GNAT, GNATBIND
 124    --  Set True if package System has the line "type Address is private;"
 125
 126    All_Errors_Mode : Boolean := False;
 127    --  GNAT
 128    --  Flag set to force display of multiple errors on a single line and
 129    --  also repeated error messages for references to undefined identifiers
 130    --  and certain other repeated error messages. Set by use of -gnatf.
 131
 132    All_Sources : Boolean := False;
 133    --  GNATBIND
 134    --  Set to True to require all source files to be present. This flag is
 135    --  directly modified by gnatmake to affect the shared binder routines.
 136
 137    Alternate_Main_Name : String_Ptr := null;
 138    --  GNATBIND
 139    --  Set to non null when Bind_Alternate_Main_Name is True. This value
 140    --  is modified as needed by Gnatbind.Scan_Bind_Arg.
 141
 142    Assertions_Enabled : Boolean := False;
 143    --  GNAT
 144    --  Enable assertions made using pragma Assert
 145
 146    ASIS_Mode : Boolean := False;
 147    --  GNAT
 148    --  Enable semantic checks and tree transformations that are important
 149    --  for ASIS but that are usually skipped if Operating_Mode is set to
 150    --  Check_Semantics. This flag does not have the corresponding option to set
 151    --  it ON. It is set ON when Tree_Output is set ON, it can also be set ON
 152    --  from the code of GNSA-based tool (a client may need to set ON the
 153    --  Back_Annotate_Rep_Info flag in this case. At the moment this does not
 154    --  make very much sense, because GNSA cannot do back annotation).
 155
 156    Back_Annotate_Rep_Info : Boolean := False;
 157    --  GNAT
 158    --  If set True, enables back annotation of representation information
 159    --  by gigi, even in -gnatc mode. This is set True by the use of -gnatR
 160    --  (list representation information) or -gnatt (generate tree). It is
 161    --  also set true if certain Unchecked_Conversion instantiations require
 162    --  checking based on annotated values.
 163
 164    Bind_Alternate_Main_Name : Boolean := False;
 165    --  GNATBIND
 166    --  True if main should be called Alternate_Main_Name.all.
 167    --  This variable may be set to True by Gnatbind.Scan_Bind_Arg.
 168
 169    Bind_Main_Program : Boolean := True;
 170    --  GNATBIND
 171    --  Set to False if not binding main Ada program
 172
 173    Bind_For_Library : Boolean := False;
 174    --  GNATBIND
 175    --  Set to True if the binder needs to generate a file designed for
 176    --  building a library. May be set to True by Gnatbind.Scan_Bind_Arg.
 177
 178    Bind_Only : Boolean := False;
 179    --  GNATMAKE, GPRMAKE
 180    --  Set to True to skip compile and link steps
 181    --  (except when Compile_Only and/or Link_Only are True).
 182
 183    Blank_Deleted_Lines : Boolean := False;
 184    --  GNAT, GNATPREP
 185    --  Output empty lines for each line of preprocessed input that is deleted
 186    --  in the output, including preprocessor lines starting with a '#'.
 187
 188    Brief_Output : Boolean := False;
 189    --  GNAT, GNATBIND
 190    --  Force brief error messages to standard error, even if verbose mode is
 191    --  set (so that main error messages go to standard output).
 192
 193    Build_Bind_And_Link_Full_Project : Boolean := False;
 194    --  GNATMAKE
 195    --  Set to True to build, bind and link all the sources of a project file
 196    --  (switch -B)
 197
 198    Check_Object_Consistency : Boolean := False;
 199    --  GNATBIND, GNATMAKE
 200    --  Set to True to check whether every object file is consistent with
 201    --  its corresponding ada library information (ALI) file. An object
 202    --  file is inconsistent with the corresponding ALI file if the object
 203    --  file does not exist or if it has an older time stamp than the ALI file.
 204    --  Default above is for GNATBIND. GNATMAKE overrides this default to
 205    --  True (see Make.Initialize) since we normally do need to check source
 206    --  consistencies in gnatmake.
 207
 208    Check_Only : Boolean := False;
 209    --  GNATBIND
 210    --  Set to True to do checks only, no output of binder file
 211
 212    Check_Readonly_Files : Boolean := False;
 213    --  GNATMAKE
 214    --  Set to True to check readonly files during the make process
 215
 216    Check_Source_Files : Boolean := True;
 217    --  GNATBIND, GNATMAKE
 218    --  Set to True to enable consistency checking for any source files that
 219    --  are present (i.e. date must match the date in the library info file).
 220    --  Set to False for object file consistency check only. This flag is
 221    --  directly modified by gnatmake, to affect the shared binder routines.
 222
 223    Check_Switches : Boolean := False;
 224    --  GNATMAKE, GPRMAKE
 225    --  Set to True to check compiler options during the make process
 226
 227    Check_Unreferenced : Boolean := False;
 228    --  GNAT
 229    --  Set to True to enable checking for unreferenced entities other
 230    --  than formal parameters (for which see Check_Unreferenced_Formals)
 231
 232    Check_Unreferenced_Formals : Boolean := False;
 233    --  GNAT
 234    --  Set True to check for unreferenced formals. This is turned on by
 235    --  -gnatwa/wf/wu and turned off by -gnatwA/wF/wU.
 236
 237    Check_Withs : Boolean := False;
 238    --  GNAT
 239    --  Set to True to enable checking for unused withs, and also the case
 240    --  of withing a package and using none of the entities in the package.
 241
 242    Commands_To_Stdout : Boolean := False;
 243    --  GNATMAKE
 244    --  True if echoed commands to be written to stdout instead of stderr
 245
 246    Comment_Deleted_Lines : Boolean := False;
 247    --  GNATPREP
 248    --  True if source lines removed by the preprocessor should be commented
 249    --  in the output file.
 250
 251    Compile_Only : Boolean := False;
 252    --  GNATMAKE, GNATCLEAN, GPRMAKE
 253    --  GNATMAKE, GPRMAKE: set to True to skip bind and link steps (except when
 254    --                     Bind_Only is True).
 255    --  GNATCLEAN: set to True to only the files produced by the compiler are to
 256    --             be deleted, but not the library files or executable files.
 257
 258    Config_File : Boolean := True;
 259    --  GNAT
 260    --  Set to False to inhibit reading and processing of gnat.adc file
 261
 262    Config_File_Names : String_List_Access := null;
 263    --  GNAT
 264    --  Names of configuration pragmas files (given by switches -gnatec)
 265
 266    Configurable_Run_Time_Mode : Boolean := False;
 267    --  GNAT, GNATBIND
 268    --  Set True if the compiler is operating in configurable run-time mode.
 269    --  This happens if the flag Targparm.Configurable_Run_TimeMode_On_Target
 270    --  is set True, or if pragma No_Run_Time is used. See the spec of Rtsfind
 271    --  for details on the handling of the latter pragma.
 272
 273    Constant_Condition_Warnings : Boolean := False;
 274    --  GNAT
 275    --  Set to True to activate warnings on constant conditions
 276
 277    Create_Mapping_File : Boolean := False;
 278    --  GNATMAKE, GPRMAKE
 279    --  Set to True (-C switch) to indicate that the compiler will be invoked
 280    --  with a mapping file (-gnatem compiler switch).
 281
 282    Debug_Pragmas_Enabled : Boolean := False;
 283    --  GNAT
 284    --  Enable debug statements from pragma Debug
 285
 286    subtype Debug_Level_Value is Nat range 0 .. 3;
 287    Debugger_Level : Debug_Level_Value := 0;
 288    --  GNATBIND
 289    --  The value given to the -g parameter. The default value for -g with
 290    --  no value is 2. This is usually ignored by GNATBIND, except in the
 291    --  VMS version where it is passed as an argument to __gnat_initialize
 292    --  to trigger the activation of the remote debugging interface.
 293    --  Is this still true ???
 294
 295    Debug_Generated_Code : Boolean := False;
 296    --  GNAT
 297    --  Set True (-gnatD switch) to debug generated expanded code instead
 298    --  of the original source code. Causes debugging information to be
 299    --  written with respect to the generated code file that is written.
 300
 301    Default_Exit_Status : Int := 0;
 302    --  GNATBIND
 303    --  Set the default exit status value. Set by the -Xnnn switch for the
 304    --  binder.
 305
 306    Default_Stack_Size : Int := -1;
 307    --  GNATBIND
 308    --  Set to default primary stack size in units of bytes. Set by
 309    --  the -dnnn switch for the binder. A value of -1 indicates that no
 310    --  default was set by the binder.
 311
 312    Default_Sec_Stack_Size : Int := -1;
 313    --  GNATBIND
 314    --  Set to default secondary stack size in units of bytes. Set by
 315    --  the -Dnnn switch for the binder. A value of -1 indicates that no
 316    --  default was set by the binder, and that the default should be the
 317    --  initial value of System.Secondary_Stack.Default_Secondary_Stack_Size.
 318
 319    Detect_Blocking : Boolean := False;
 320    --  GNAT
 321    --  Set True to force the run time to raise Program_Error if calls to
 322    --  potentially blocking operations are detected from protected actions.
 323
 324    Display_Compilation_Progress : Boolean := False;
 325    --  GNATMAKE, GPRMAKE
 326    --  Set True (-d switch) to display information on progress while compiling
 327    --  files. Internal flag to be used in conjunction with an IDE (e.g GPS).
 328
 329    type Distribution_Stub_Mode_Type is
 330    --  GNAT
 331      (No_Stubs,
 332       --  Normal mode, no generation/compilation of distribution stubs
 333
 334       Generate_Receiver_Stub_Body,
 335       --  The unit being compiled is the RCI body, and the compiler will
 336       --  generate the body for the receiver stubs and compile it.
 337
 338       Generate_Caller_Stub_Body);
 339       --  The unit being compiled is the RCI spec, and the compiler will
 340       --  generate the body for the caller stubs and compile it.
 341
 342    Distribution_Stub_Mode : Distribution_Stub_Mode_Type := No_Stubs;
 343    --  GNAT
 344    --  This enumeration variable indicates the five states of distribution
 345    --  annex stub generation/compilation.
 346
 347    Do_Not_Execute : Boolean := False;
 348    --  GNATMAKE
 349    --  Set to True if no actual compilations should be undertaken.
 350
 351    Dump_Source_Text : Boolean := False;
 352    --  GNAT
 353    --  Set to True (by -gnatL) to dump source text intermingled with generated
 354    --  code. Effective only if either of Debug/Print_Generated_Code is true.
 355
 356    Dynamic_Elaboration_Checks : Boolean := False;
 357    --  GNAT
 358    --  Set True for dynamic elaboration checking mode, as set by the -gnatE
 359    --  switch or by the use of pragma Elaboration_Checks (Dynamic).
 360
 361    Dynamic_Stack_Measurement : Boolean := False;
 362    --  GNATBIND
 363    --  Set True to enable dynamic stack measurement (-u flag for gnatbind)
 364
 365    Dynamic_Stack_Measurement_Array_Size : Nat := 100;
 366    --  GNATBIND
 367    --  Number of measurements we want to store during dynamic stack analysis.
 368    --  When the buffer is full, non-storable results will be output on the fly.
 369    --  The value is relevant only if Dynamic_Stack_Measurement is set. Set
 370    --  by processing of -u flag for gnatbind.
 371
 372    Elab_Dependency_Output : Boolean := False;
 373    --  GNATBIND
 374    --  Set to True to output complete list of elaboration constraints
 375
 376    Elab_Order_Output : Boolean := False;
 377    --  GNATBIND
 378    --  Set to True to output chosen elaboration order
 379
 380    Elab_Warnings : Boolean := False;
 381    --  GNAT
 382    --  Set to True to generate full elaboration warnings (-gnatwl)
 383
 384    Enable_Overflow_Checks : Boolean := False;
 385    --  GNAT
 386    --  Set to True if -gnato (enable overflow checks) switch is set,
 387    --  but not -gnatp.
 388
 389    Error_Msg_Line_Length : Nat := 0;
 390    --  GNAT
 391    --  Records the error message line length limit. If this is set to zero,
 392    --  then we get the old style behavior, in which each call to the error
 393    --  message routines generates one line of output as a separate message.
 394    --  If it is set to a non-zero value, then continuation lines are folded
 395    --  to make a single long message, and then this message is split up into
 396    --  multiple lines not exceeding the specified length. Set by -gnatLnnn.
 397
 398    Exception_Locations_Suppressed : Boolean := False;
 399    --  GNAT
 400    --  This flag is set True if a Suppress_Exception_Locations configuration
 401    --  pragma is currently active.
 402
 403    type Exception_Mechanism_Type is
 404    --  Determines the handling of exceptions. See Exp_Ch11 for details
 405    --
 406      (Front_End_Setjmp_Longjmp_Exceptions,
 407       --  Exceptions use setjmp/longjmp generated explicitly by the
 408       --  front end (this includes gigi or other equivalent parts of
 409       --  the code generator). AT END handlers are converted into
 410       --  exception handlers by the front end in this mode.
 411
 412       Back_End_Exceptions);
 413       --  Exceptions are handled by the back end. The front end simply
 414       --  generates the handlers as they appear in the source, and AT
 415       --  END handlers are left untouched (they are not converted into
 416       --  exception handlers when operating in this mode.
 417    pragma Convention (C, Exception_Mechanism_Type);
 418
 419    Exception_Mechanism : Exception_Mechanism_Type :=
 420                            Front_End_Setjmp_Longjmp_Exceptions;
 421    --  GNAT
 422    --  Set to the appropriate value depending on the default as given in
 423    --  system.ads (ZCX_By_Default, GCC_ZCX_Support).
 424    --  The C convention is there to make this variable accessible to gigi.
 425
 426    Exception_Tracebacks : Boolean := False;
 427    --  GNATBIND
 428    --  Set to True to store tracebacks in exception occurrences (-E)
 429
 430    Extensions_Allowed : Boolean := False;
 431    --  GNAT
 432    --  Set to True by switch -gnatX if GNAT specific language extensions
 433    --  are allowed. For example, the use of 'Constrained with objects of
 434    --  generic types is a GNAT extension.
 435
 436    type External_Casing_Type is (
 437      As_Is,       -- External names cased as they appear in the Ada source
 438      Uppercase,   -- External names forced to all uppercase letters
 439      Lowercase);  -- External names forced to all lowercase letters
 440
 441    External_Name_Imp_Casing : External_Casing_Type := Lowercase;
 442    --  GNAT
 443    --  The setting of this flag determines the casing of external names
 444    --  when the name is implicitly derived from an entity name (i.e. either
 445    --  no explicit External_Name or Link_Name argument is used, or, in the
 446    --  case of extended DEC pragmas, the external name is given using an
 447    --  identifier. The As_Is setting is not permitted here (since this would
 448    --  create Ada source programs that were case sensitive).
 449
 450    External_Name_Exp_Casing : External_Casing_Type := As_Is;
 451    --  GNAT
 452    --  The setting of this flag determines the casing of an external name
 453    --  specified explicitly with a string literal. As_Is means the string
 454    --  literal is used as given with no modification to the casing. If
 455    --  Lowercase or Uppercase is set, then the string is forced to all
 456    --  lowercase or all uppercase letters as appropriate. Note that this
 457    --  setting has no effect if the external name is given using an identifier
 458    --  in the case of extended DEC import/export pragmas (in this case the
 459    --  casing is controlled by External_Name_Imp_Casing), and also has no
 460    --  effect if an explicit Link_Name is supplied (a link name is always
 461    --  used exactly as given).
 462
 463    External_Unit_Compilation_Allowed : Boolean := False;
 464    --  GNATMAKE
 465    --  When True (set by gnatmake switch -x), allow compilation of sources
 466    --  that are not part of any project file.
 467
 468    Float_Format : Character := ' ';
 469    --  GNAT
 470    --  A non-blank value indicates that a Float_Format pragma has been
 471    --  processed, in which case this variable is set to 'I' for IEEE or
 472    --  to 'V' for VAX. The setting of 'V' is only possible on OpenVMS
 473    --  versions of GNAT.
 474
 475    Float_Format_Long : Character := ' ';
 476    --  GNAT
 477    --  A non-blank value indicates that a Long_Float pragma has been
 478    --  processed (this pragma is recognized only in OpenVMS versions
 479    --  of GNAT), in which case this variable is set to D or G for
 480    --  D_Float or G_Float.
 481
 482    Force_ALI_Tree_File : Boolean := False;
 483    --  GNAT
 484    --  Force generation of ALI file even if errors are encountered.
 485    --  Also forces generation of tree file if -gnatt is also set.
 486
 487    Force_Checking_Of_Elaboration_Flags : Boolean := False;
 488    --  GNATBIND
 489    --  True if binding with forced checking of the elaboration flags
 490    --  (-F switch set).
 491
 492    Force_Compilations : Boolean := False;
 493    --  GNATMAKE, GPRMAKE
 494    --  Set to force recompilations even when the objects are up-to-date.
 495
 496    Full_Path_Name_For_Brief_Errors : Boolean := False;
 497    --  GNAT, GNATMAKE, GNATCLEAN, GPRMAKE
 498    --  When True, in Brief_Output mode, each error message line
 499    --  will start with the full path name of the source.
 500    --  When False, only the file name without directory information
 501    --  is used.
 502
 503    Full_List : Boolean := False;
 504    --  GNAT
 505    --  Set True to generate full source listing with embedded errors
 506
 507    Full_List_File_Name : String_Ptr := null;
 508    --  GNAT
 509    --  Set to file name to generate full source listing to named file (or if
 510    --  the name is of the form .xxx, then to name.xxx where name is the source
 511    --  file name with extension stripped.
 512
 513    Generating_Code : Boolean := False;
 514    --  GNAT
 515    --  True if the frontend finished its work and has called the backend to
 516    --  processs the tree and generate the object file.
 517
 518    Global_Discard_Names : Boolean := False;
 519    --  GNAT, GNATBIND
 520    --  True if a pragma Discard_Names appeared as a configuration pragma for
 521    --  the current compilation unit.
 522
 523    GNAT_Mode : Boolean := False;
 524    --  GNAT
 525    --  True if compiling in GNAT system mode (-gnatg switch)
 526
 527    HLO_Active : Boolean := False;
 528    --  GNAT
 529    --  True if High Level Optimizer is activated (-gnatH switch)
 530
 531    Identifier_Character_Set : Character;
 532    --  GNAT
 533    --  This variable indicates the character set to be used for identifiers.
 534    --  The possible settings are:
 535    --    '1'  Latin-5 (ISO-8859-1)
 536    --    '2'  Latin-5 (ISO-8859-2)
 537    --    '3'  Latin-5 (ISO-8859-3)
 538    --    '4'  Latin-5 (ISO-8859-4)
 539    --    '5'  Latin-5 (ISO-8859-5, Cyrillic)
 540    --    '9'  Latin-5 (ISO-8859-9)
 541    --    'p'  PC (US, IBM page 437)
 542    --    '8'  PC (European, IBM page 850)
 543    --    'f'  Full upper set (all distinct)
 544    --    'n'  No upper characters (Ada 83 rules)
 545    --    'w'  Latin-1 plus wide characters allowed in identifiers
 546    --
 547    --  The setting affects the set of letters allowed in identifiers and the
 548    --  upper/lower case equivalences. It does not affect the interpretation of
 549    --  character and string literals, which are always stored using the actual
 550    --  coding in the source program. This variable is initialized to the
 551    --  default value appropriate to the system (in Osint.Initialize), and then
 552    --  reset if a command line switch is used to change the setting.
 553
 554    Ignore_Rep_Clauses : Boolean := False;
 555    --  GNAT
 556    --  Set True to ignore all representation clauses. Useful when compiling
 557    --  code from foreign compilers for checking or ASIS purposes. Can be
 558    --  set True by use of -gnatI.
 559
 560    Implementation_Unit_Warnings : Boolean := True;
 561    --  GNAT
 562    --  Set True to active warnings for use of implementation internal units.
 563    --  Can be controlled by use of -gnatwi/-gnatwI.
 564
 565    Implicit_Packing : Boolean := False;
 566    --  GNAT
 567    --  If set True, then a Size attribute clause on an array is allowed to
 568    --  cause implicit packing instead of generating an error message. Set by
 569    --  use of pragma Implicit_Packing.
 570
 571    Ineffective_Inline_Warnings : Boolean := False;
 572    --  GNAT
 573    --  Set True to activate warnings if front-end inlining (-gnatN) is not
 574    --  able to actually inline a particular call (or all calls). Can be
 575    --  controlled by use of -gnatwp/-gnatwP.
 576
 577    Init_Or_Norm_Scalars : Boolean := False;
 578    --  GNAT, GANTBIND
 579    --  Set True if a pragma Initialize_Scalars applies to the current unit.
 580    --  Also set True if a pragma Normalize_Scalars applies.
 581
 582    Initialize_Scalars : Boolean := False;
 583    --  GNAT
 584    --  Set True if a pragma Initialize_Scalars applies to the current unit.
 585    --  Note that Init_Or_Norm_Scalars is also set to True if this is True.
 586
 587    Initialize_Scalars_Mode1 : Character := 'I';
 588    Initialize_Scalars_Mode2 : Character := 'N';
 589    --  GNATBIND
 590    --  Set to two characters from -S switch (IN/LO/HI/EV/xx). The default
 591    --  is IN (invalid values), used if no -S switch is used.
 592
 593    Inline_Active : Boolean := False;
 594    --  GNAT
 595    --  Set True to activate pragma Inline processing across modules. Default
 596    --  for now is not to inline across module boundaries.
 597
 598    Interface_Library_Unit : Boolean := False;
 599    --  GNATBIND
 600    --  Set to True to indicate that at least one ALI file is an interface ALI:
 601    --  then elaboration flag checks are to be generated in the binder
 602    --  generated file.
 603
 604    Follow_Links : Boolean := False;
 605    --  GNATMAKE
 606    --  Set to True (-eL) to process the project files in trusted mode
 607
 608    Front_End_Inlining : Boolean := False;
 609    --  GNAT
 610    --  Set True to activate inlining by front-end expansion
 611
 612    Inline_Processing_Required : Boolean := False;
 613    --  GNAT
 614    --  Set True if inline processing is required. Inline processing is
 615    --  required if an active Inline pragma is processed. The flag is set
 616    --  for a pragma Inline or Inline_Always that is actually active.
 617
 618    In_Place_Mode : Boolean := False;
 619    --  GNATMAKE
 620    --  Set True to store ALI and object files in place ie in the object
 621    --  directory if these files already exist or in the source directory
 622    --  if not.
 623
 624    Keep_Going : Boolean := False;
 625    --  GNATMAKE, GPRMAKE
 626    --  When True signals to ignore compilation errors and keep
 627    --  processing sources until there is no more work.
 628
 629    Keep_Temporary_Files : Boolean := False;
 630    --  GNATCMD
 631    --  When True the temporary files created by the GNAT driver are not
 632    --  deleted. Set by switch -dn or qualifier /KEEP_TEMPORARY_FILES.
 633
 634    Leap_Seconds_Support : Boolean := False;
 635    --  GNATBIND
 636    --  Set to True to enable leap seconds support in Ada.Calendar and its
 637    --  children.
 638
 639    Link_Only : Boolean := False;
 640    --  GNATMAKE, GPRMAKE
 641    --  Set to True to skip compile and bind steps
 642    --  (except when Bind_Only is set to True).
 643
 644    List_Restrictions : Boolean := False;
 645    --  GNATBIND
 646    --  Set to True to list restrictions pragmas that could apply to partition
 647
 648    List_Units : Boolean := False;
 649    --  GNAT
 650    --  List units in the active library for a compilation (-gnatu switch)
 651
 652    List_Closure : Boolean := False;
 653    --  GNATBIND
 654    --  List all sources in the closure of a main (-R gnatbind switch)
 655
 656    List_Dependencies : Boolean := False;
 657    --  GNATMAKE
 658    --  When True gnatmake verifies that the objects are up to date and
 659    --  outputs the list of object dependencies (-M switch).
 660    --  Output depends if -a switch is used or not.
 661    --  This list can be used directly in a Makefile.
 662
 663    List_Representation_Info : Int range 0 .. 3 := 0;
 664    --  GNAT
 665    --  Set non-zero by -gnatR switch to list representation information.
 666    --  The settings are as follows:
 667    --
 668    --    0 = no listing of representation information (default as above)
 669    --    1 = list rep info for user defined record and array types
 670    --    2 = list rep info for all user defined types and objects
 671    --    3 = like 2, but variable fields are decoded symbolically
 672
 673    List_Representation_Info_To_File : Boolean := False;
 674    --  GNAT
 675    --  Set true by -gnatRs switch. Causes information from -gnatR/1/2/3
 676    --  to be written to file.rep (where file is the name of the source
 677    --  file) instead of stdout. For example, if file x.adb is compiled
 678    --  using -gnatR2s then representation info is written to x.adb.ref.
 679
 680    List_Representation_Info_Mechanisms : Boolean := False;
 681    --  GNAT
 682    --  Set true by -gnatRm switch. Causes information on mechanisms to
 683    --  be included in the representation output information.
 684
 685    List_Preprocessing_Symbols : Boolean := False;
 686    --  GNAT, GNATPREP
 687    --  Set to True if symbols for preprocessing a source are to be listed
 688    --  before preprocessing occurs. Set to True by switch -s of gnatprep
 689    --  or -s in preprocessing data file for the compiler.
 690
 691    type Create_Repinfo_File_Proc is access procedure (Src  : String);
 692    type Write_Repinfo_Line_Proc  is access procedure (Info : String);
 693    type Close_Repinfo_File_Proc  is access procedure;
 694    --  Types used for procedure addresses below
 695
 696    Create_Repinfo_File_Access : Create_Repinfo_File_Proc := null;
 697    Write_Repinfo_Line_Access  : Write_Repinfo_Line_Proc  := null;
 698    Close_Repinfo_File_Access  : Close_Repinfo_File_Proc  := null;
 699    --  GNAT
 700    --  These three locations are left null when operating in non-compiler
 701    --  (e.g. ASIS mode), but when operating in compiler mode, they are
 702    --  set to point to the three corresponding procedures in Osint-C. The
 703    --  reason for this slightly strange interface is to prevent Repinfo
 704    --  from dragging in Osint in ASIS mode, which would include a lot of
 705    --  unwanted units in the ASIS build.
 706
 707    type Create_List_File_Proc is access procedure (S : String);
 708    type Write_List_Info_Proc  is access procedure (S : String);
 709    type Close_List_File_Proc  is access procedure;
 710    --  Types used for procedure addresses below
 711
 712    Create_List_File_Access : Create_List_File_Proc := null;
 713    Write_List_Info_Access  : Write_List_Info_Proc  := null;
 714    Close_List_File_Access  : Close_List_File_Proc  := null;
 715    --  GNAT
 716    --  These three locations are left null when operating in non-compiler
 717    --  (e.g. from the binder), but when operating in compiler mode, they are
 718    --  set to point to the three corresponding procedures in Osint-C. The
 719    --  reason for this slightly strange interface is to prevent Repinfo
 720    --  from dragging in Osint-C in the binder, which would include unwanted
 721    --  units in the  binder.
 722
 723    Locking_Policy : Character := ' ';
 724    --  GNAT, GNATBIND
 725    --  Set to ' ' for the default case (no locking policy specified).
 726    --  Reset to first character (uppercase) of locking policy name if a
 727    --  valid pragma Locking_Policy is encountered.
 728
 729    Locking_Policy_Sloc : Source_Ptr := No_Location;
 730    --  GNAT, GNATBIND
 731    --  Remember location of previous Locking_Policy pragma. This is used
 732    --  for inconsistency error messages. A value of System_Location is
 733    --  used if the policy is set in package System.
 734
 735    Look_In_Primary_Dir : Boolean := True;
 736    --  GNAT, GNATBIND, GNATMAKE, GNATCLEAN
 737    --  Set to False if a -I- was present on the command line.
 738    --  When True we are allowed to look in the primary directory to locate
 739    --  other source or library files.
 740
 741    Make_Steps : Boolean := False;
 742    --  GNATMAKE
 743    --  Set to True when either Compile_Only, Bind_Only or Link_Only is
 744    --  set to True.
 745
 746    Main_Index : Int := 0;
 747    --  GNATMAKE
 748    --  This is set to non-zero by gnatmake switch -eInnn to indicate that
 749    --  the main program is the nnn unit in a multi-unit source file.
 750
 751    Mapping_File_Name : String_Ptr := null;
 752    --  GNAT
 753    --  File name of mapping between unit names, file names and path names.
 754    --  (given by switch -gnatem)
 755
 756    Maximum_Errors : Int := 9999;
 757    --  GNAT, GNATBIND
 758    --  Maximum default number of errors before compilation is terminated.
 759    --  Can be overridden using -gnatm (GNAT) or -m (GNATBIND) switch.
 760
 761    Maximum_File_Name_Length : Int;
 762    --  GNAT, GNATBIND
 763    --  Maximum number of characters allowed in a file name, not counting the
 764    --  extension, as set by the appropriate switch. If no switch is given,
 765    --  then this value is initialized by Osint to the appropriate value.
 766
 767    Maximum_Processes : Positive := 1;
 768    --  GNATMAKE, GPRMAKE
 769    --  Maximum number of processes that should be spawned to carry out
 770    --  compilations.
 771
 772    Minimal_Recompilation : Boolean := False;
 773    --  GNATMAKE
 774    --  Set to True if minimal recompilation mode requested
 775
 776    Special_Exception_Package_Used : Boolean := False;
 777    --  GNAT
 778    --  Set to True if either of the unit GNAT.Most_Recent_Exception or
 779    --  GNAT.Exception_Traces is with'ed. Used to inhibit transformation of
 780    --  local raise statements into gotos in the presence of either package.
 781
 782    Multiple_Unit_Index : Int;
 783    --  GNAT
 784    --  This is set non-zero if the current unit is being compiled in multiple
 785    --  unit per file mode, meaning that the current unit is selected from the
 786    --  sequence of units in the current source file, using the value stored
 787    --  in this variable (e.g. 2 = select second unit in file). A value of
 788    --  zero indicates that we are in normal (one unit per file) mode.
 789
 790    No_Main_Subprogram : Boolean := False;
 791    --  GNATMAKE, GNATBIND
 792    --  Set to True if compilation/binding of a program without main
 793    --  subprogram requested.
 794
 795    No_Run_Time_Mode : Boolean := False;
 796    --  GNAT, GNATBIND
 797    --  This flag is set True if a No_Run_Time pragma is encountered. See
 798    --  spec of Rtsfind for a full description of handling of this pragma.
 799
 800    No_Stdinc : Boolean := False;
 801    --  GNAT, GNATBIND, GNATMAKE, GNATFIND, GNATXREF
 802    --  Set to True if no default source search dirs added to search list
 803
 804    No_Stdlib : Boolean := False;
 805    --  GNATMAKE, GNATBIND, GNATFIND, GNATXREF
 806    --  Set to True if no default library search dirs added to search list
 807
 808    No_Strict_Aliasing : Boolean := False;
 809    --  GNAT
 810    --  Set True if pragma No_Strict_Aliasing with no parameters encountered
 811
 812    Normalize_Scalars : Boolean := False;
 813    --  GNAT, GNATBIND
 814    --  Set True if a pragma Normalize_Scalars applies to the current unit.
 815    --  Note that Init_Or_Norm_Scalars is also set to True if this is True.
 816
 817    Object_Directory_Present : Boolean := False;
 818    --  GNATMAKE
 819    --  Set to True when an object directory is specified with option -D
 820
 821    type Operating_Mode_Type is (Check_Syntax, Check_Semantics, Generate_Code);
 822    Operating_Mode : Operating_Mode_Type := Generate_Code;
 823    --  GNAT
 824    --  Indicates the operating mode of the compiler. The default is generate
 825    --  code, which runs the parser, semantics and backend. Switches can be
 826    --  used to set syntax checking only mode, or syntax and semantics checking
 827    --  only mode. Operating_Mode can also be modified as a result of detecting
 828    --  errors during the compilation process. In particular if any serious
 829    --  error is detected then this flag is reset from Generate_Code to
 830    --  Check_Semantics after generating an error message.
 831
 832    Original_Operating_Mode : Operating_Mode_Type := Generate_Code;
 833    --  GNAT
 834    --  Indicates the original operating mode of the compiler as set by
 835    --  compiler options. This is identical to Operating_Mode except that
 836    --  this is not affected by errors.
 837
 838    Optimization_Level : Int;
 839    pragma Import (C, Optimization_Level, "optimize");
 840    --  This constant reflects the optimization level (0,1,2 for -O0,-O1,-O2)
 841
 842    Output_File_Name_Present : Boolean := False;
 843    --  GNATBIND, GNAT, GNATMAKE, GPRMAKE
 844    --  Set to True when the output C file name is given with option -o
 845    --  for GNATBIND, when the object file name is given with option
 846    --  -gnatO for GNAT or when the executable is given with option -o
 847    --  for GNATMAKE or GPRMAKE.
 848
 849    Output_Linker_Option_List : Boolean := False;
 850    --  GNATBIND
 851    --  True if output of list of linker options is requested (-K switch set)
 852
 853    Output_Object_List : Boolean := False;
 854    --  GNATBIND
 855    --  True if output of list of objects is requested (-O switch set)
 856
 857    Overflow_Checks_Unsuppressed : Boolean := False;
 858    --  GNAT
 859    --  Set to True if at least one pragma Unsuppress
 860    --  (All_Checks|Overflow_Checks) has been processed.
 861
 862    Persistent_BSS_Mode : Boolean := False;
 863    --  GNAT
 864    --  True if a Persistent_BSS configuration pragma is in effect, causing
 865    --  potentially persistent data to be placed in the persistent_bss section.
 866
 867    Pessimistic_Elab_Order : Boolean := False;
 868    --  GNATBIND
 869    --  True if pessimistic elaboration order is to be chosen (-p switch set)
 870
 871    Polling_Required : Boolean := False;
 872    --  GNAT
 873    --  Set to True if polling for asynchronous abort is enabled by using
 874    --  the -gnatP option for GNAT.
 875
 876    Preprocessing_Data_File : String_Ptr := null;
 877    --  GNAT
 878    --  Set by switch -gnatep=. The file name of the prepocessing data file.
 879
 880    Print_Generated_Code : Boolean := False;
 881    --  GNAT
 882    --  Set to True to enable output of generated code in source form. This
 883    --  flag is set by the -gnatG switch.
 884
 885    Print_Standard : Boolean := False;
 886    --  GNAT
 887    --  Set to true to enable printing of package standard in source form.
 888    --  This flag is set by the -gnatS switch
 889
 890    Propagate_Exceptions : Boolean := False;
 891    --  GNAT
 892    --  Indicates if subprogram descriptor exception tables should be
 893    --  built for imported subprograms. Set True if a Propagate_Exceptions
 894    --  pragma applies to the extended main unit.
 895
 896    type Usage is (Unknown, Not_In_Use, In_Use);
 897    Project_File_In_Use : Usage := Unknown;
 898    --  GNAT
 899    --  Indicates if a project file is used or not.
 900    --  Set to In_Use by the first SFNP pragma.
 901
 902    Queuing_Policy : Character := ' ';
 903    --  GNAT, GNATBIND
 904    --  Set to ' ' for the default case (no queuing policy specified).
 905    --  Reset to first character (uppercase) of locking policy name if a valid
 906    --  Queuing_Policy pragma is encountered.
 907
 908    Queuing_Policy_Sloc : Source_Ptr := No_Location;
 909    --  GNAT, GNATBIND
 910    --  Remember location of previous Queuing_Policy pragma. This is used
 911    --  for inconsistency error messages. A value of System_Location is
 912    --  used if the policy is set in package System.
 913
 914    Quiet_Output : Boolean := False;
 915    --  GNATMAKE, GNATCLEAN, GPRMAKE
 916    --  Set to True if the tool should not have any output if there are no
 917    --  errors or warnings.
 918
 919    Replace_In_Comments : Boolean := False;
 920    --  GNATPREP
 921    --  Set to True if -C switch used
 922
 923    RTS_Lib_Path_Name : String_Ptr := null;
 924    RTS_Src_Path_Name : String_Ptr := null;
 925    --  GNAT
 926    --  Set to the "adalib" and "adainclude" directories of the run time
 927    --  specified by --RTS=.
 928
 929    RTS_Switch : Boolean := False;
 930    --  GNAT, GNATMAKE, GNATBIND, GNATLS, GNATFIND, GNATXREF
 931    --  Set to True when the --RTS switch is set
 932
 933    Run_Path_Option : Boolean := True;
 934    --  GNATMAKE, GNATLINK
 935    --  Set to False when no run_path_option should be issued to the linker
 936
 937    Search_Directory_Present : Boolean := False;
 938    --  GNAT
 939    --  Set to True when argument is -I. Reset to False when next argument,
 940    --  a search directory path is taken into account. Note that this is
 941    --  quite different from other switches in this section in that it is
 942    --  only set in a transitory manner as a result of scanning a -I switch
 943    --  with no file name, and if set, is an indication that the next argument
 944    --  is to be treated as a file name.
 945
 946    Sec_Stack_Used : Boolean := False;
 947    --  GNAT, GBATBIND
 948    --  Set True if generated code uses the System.Secondary_Stack package.
 949    --  For the binder, set if any unit uses the secondary stack package.
 950
 951    Setup_Projects : Boolean := False;
 952    --  GNAT DRIVER
 953    --  Set to True for GNAT SETUP: the Project Manager creates non existing
 954    --  object, library and exec directories.
 955
 956    Shared_Libgnat : Boolean;
 957    --  GNATBIND
 958    --  Set to True if a shared libgnat is requested by using the -shared
 959    --  option for GNATBIND and to False when using the -static option. The
 960    --  value of this flag is set by Gnatbind.Scan_Bind_Arg.
 961
 962    Stack_Checking_Enabled : Boolean;
 963    --  GNAT
 964    --  Set to indicate if -fstack-check switch is set for the compilation. True
 965    --  means that the switch is set, so that stack checking is enabled. False
 966    --  means that the switch is not set (no stack checking). This value is
 967    --  obtained from the external imported value flag_stack_check in the gcc
 968    --  backend (see Frontend) and may be referenced throughout the compilation
 969    --  phases.
 970
 971    Style_Check : Boolean := False;
 972    --  GNAT
 973    --  Set True to perform style checks. Activates checks carried out
 974    --  in package Style (see body of this package for details of checks)
 975    --  This flag is set True by either the -gnatg or -gnaty switches.
 976
 977    System_Extend_Pragma_Arg : Node_Id := Empty;
 978    --  GNAT
 979    --  Set non-empty if and only if a correct Extend_System pragma was present
 980    --  in which case it points to the argument of the pragma, and the name can
 981    --  be located as Chars (Expression (System_Extend_Pragma_Arg)).
 982
 983    System_Extend_Unit : Node_Id := Empty;
 984    --  GNAT
 985    --  This is set to Empty if GNAT_Mode is set, since pragma Extend_System
 986    --  is never appropriate in GNAT_Mode (and causes troubles, including
 987    --  bogus circularities, if we try to compile the run-time library with
 988    --  a System extension). If GNAT_Mode is not set, then System_Extend_Unit
 989    --  is a copy of the value set in System_Extend_Pragma_Arg.
 990
 991    Subunits_Missing : Boolean := False;
 992    --  GNAT
 993    --  This flag is set true if missing subunits are detected with code
 994    --  generation active. This causes code generation to be skipped.
 995
 996    Suppress_Checks : Boolean := False;
 997    --  GNAT
 998    --  Set to True if -gnatp (suppress all checks) switch present.
 999
1000    Suppress_Options : Suppress_Array;
1001    --  GNAT
1002    --  Flags set True to suppress corresponding check, i.e. add an implicit
1003    --  pragma Suppress at the outer level of each unit compiled. Note that
1004    --  these suppress actions can be overridden by the use of the Unsuppress
1005    --  pragma. This variable is initialized by Osint.Initialize.
1006
1007    Suppress_Back_Annotation : Boolean := False;
1008    --  GNAT
1009    --  This flag is set True if back annotation of representation information
1010    --  is to be suppressed. This is set if neither -gnatt or -gnatR0-3 is set.
1011    --  This avoids unnecessary time being spent on back annotation.
1012
1013    Table_Factor : Int := 1;
1014    --  GNAT
1015    --  Factor by which all initial table sizes set in Alloc are multiplied.
1016    --  Used in Table to calculate initial table sizes (the initial table size
1017    --  is the value in Alloc, used as the Table_Initial parameter value,
1018    --  multiplied by the factor given here. The default value is used if no
1019    --  -gnatT switch appears.
1020
1021    Task_Dispatching_Policy : Character := ' ';
1022    --  GNAT, GNATBIND
1023    --  Set to ' ' for the default case (no task dispatching policy specified).
1024    --  Reset to first character (uppercase) of task dispatching policy name
1025    --  if a valid Task_Dispatching_Policy pragma is encountered.
1026
1027    Task_Dispatching_Policy_Sloc : Source_Ptr := No_Location;
1028    --  GNAT, GNATBIND
1029    --  Remember location of previous Task_Dispatching_Policy pragma. This is
1030    --  used for inconsistency error messages. A value of System_Location is
1031    --  used if the policy is set in package System.
1032
1033    Tasking_Used : Boolean := False;
1034    --  Set True if any tasking construct is encountered. Used to activate the
1035    --  output of the Q, L and T lines in ALI files.
1036
1037    Time_Slice_Set : Boolean := False;
1038    --  GNATBIND
1039    --  Set True if a pragma Time_Slice is processed in the main unit, or
1040    --  if the -gnatTnn switch is present to set a time slice value.
1041
1042    Time_Slice_Value : Nat;
1043    --  GNATBIND
1044    --  Time slice value. Valid only if Time_Slice_Set is True, i.e. if
1045    --  Time_Slice pragma has been processed. Set to the time slice value in
1046    --  microseconds. Negative values are stored as zero, and the value is not
1047    --  larger than 1_000_000_000 (1000 seconds). Values larger than this are
1048    --  reset to this maximum. This can also be set with the -gnatTnn switch.
1049
1050    Tolerate_Consistency_Errors : Boolean := False;
1051    --  GNATBIND
1052    --  Tolerate time stamp and other consistency errors. If this flag is set to
1053    --  True (-t), then inconsistencies result in warnings rather than errors.
1054
1055    Tree_Output : Boolean := False;
1056    --  GNAT
1057    --  Set to True (-gnatt) to generate output tree file
1058
1059    Try_Semantics : Boolean := False;
1060    --  GNAT
1061    --  Flag set to force attempt at semantic analysis, even if parser errors
1062    --  occur. This will probably cause blowups at this stage in the game. On
1063    --  the other hand, most such blowups will be caught cleanly and simply
1064    --  say compilation abandoned. This flag is set to True by -gnatq or -gnatQ.
1065
1066    Undefined_Symbols_Are_False : Boolean := False;
1067    --  GNAT, GNATPREP
1068    --  Set to True by switch -u of gnatprep or -u in the preprocessing data
1069    --  file for the compiler. Indicates that while preprocessing sources,
1070    --  symbols that are not defined have the value FALSE.
1071
1072    Unique_Error_Tag : Boolean := Tag_Errors;
1073    --  GNAT
1074    --  Indicates if error messages are to be prefixed by the string error:
1075    --  Initialized from Tag_Errors, can be forced on with the -gnatU switch.
1076
1077    Universal_Addressing_On_AAMP : Boolean := False;
1078    --  GNAAMP
1079    --  Indicates if library-level objects should be accessed and updated using
1080    --  universal addressing instructions on the AAMP architecture. This flag is
1081    --  set to True when pragma Universal_Data is given as a configuration
1082    --  pragma.
1083
1084    Unreserve_All_Interrupts : Boolean := False;
1085    --  GNAT, GNATBIND
1086    --  Normally set False, set True if a valid Unreserve_All_Interrupts pragma
1087    --  appears anywhere in the main unit for GNAT, or if any ALI file has the
1088    --  corresponding attribute set in GNATBIND.
1089
1090    Upper_Half_Encoding : Boolean := False;
1091    --  GNAT
1092    --  Normally set False, indicating that upper half ASCII characters are
1093    --  used in the normal way to represent themselves. If the wide character
1094    --  encoding method uses the upper bit for this encoding, then this flag is
1095    --  set True, and upper half characters in the source indicate the start of
1096    --  a wide character sequence.
1097
1098    Usage_Requested : Boolean := False;
1099    --  GNAT, GNATBIND, GNATMAKE
1100    --  Set to True if -h (-gnath for the compiler) switch encountered
1101    --  requesting usage information
1102
1103    Use_Pragma_Linker_Constructor : Boolean := False;
1104    --  GNATBIND
1105    --  True if pragma Linker_Constructor applies to adainit
1106
1107    Use_VADS_Size : Boolean := False;
1108    --  GNAT
1109    --  Set to True if a valid pragma Use_VADS_Size is processed
1110
1111    Validity_Checks_On  : Boolean := True;
1112    --  GNAT
1113    --  This flag determines if validity checking is on or off. The initial
1114    --  state is on, and the required default validity checks are active. The
1115    --  actual set of checks that is performed if Validity_Checks_On is set is
1116    --  defined by the switches in package Validsw. The Validity_Checks_On flag
1117    --  is controlled by pragma Validity_Checks (On | Off), and also some
1118    --  generated compiler code (typically code that has to do with validity
1119    --  check generation) is compiled with this flag set to False. This flag is
1120    --  set to False by the -gnatp switch.
1121
1122    Verbose_Mode : Boolean := False;
1123    --  GNAT, GNATBIND, GNATMAKE, GNATLINK, GNATLS, GNATNAME, GNATCLEAN,
1124    --  GPRMAKE
1125    --  Set to True to get verbose mode (full error message text and location
1126    --  information sent to standard output, also header, copyright and summary)
1127
1128    type Verbosity_Level_Type is (None, Low, Medium, High);
1129    Verbosity_Level : Verbosity_Level_Type := High;
1130    --  GNATMAKE, GPRMAKE
1131    --  Modified by gnatmake or gprmake switches -v, -vl, -vm, -vh. Indicates
1132    --  the level of verbosity of informational messages:
1133    --
1134    --  In Low Verbosity, the reasons why a source is recompiled, the name
1135    --  of the executable and the reason it must be rebuilt is output.
1136    --
1137    --  In Medium Verbosity, additional lines are output for each ALI file
1138    --  that is checked.
1139    --
1140    --  In High Verbosity, additional lines are output when the ALI file
1141    --  is part of an Ada library, is read-only or is part of the runtime.
1142
1143    Warn_On_Ada_2005_Compatibility : Boolean := True;
1144    --  GNAT
1145    --  Set to True to generate all warnings on Ada 2005 compatibility issues,
1146    --  including warnings on Ada 2005 obsolescent features used in Ada 2005
1147    --  mode. Set False by -gnatwY.
1148
1149    Warn_On_Assumed_Low_Bound : Boolean := True;
1150    --  GNAT
1151    --  Set to True to activate warnings for string parameters that are indexed
1152    --  with literals or S'Length, presumably assuming a lower bound of one. Set
1153    --  False by -gnatwW.
1154
1155    Warn_On_Bad_Fixed_Value : Boolean := False;
1156    --  GNAT
1157    --  Set to True to generate warnings for static fixed-point expression
1158    --  values that are not an exact multiple of the small value of the type.
1159
1160    Warn_On_Constant : Boolean := False;
1161    --  GNAT
1162    --  Set to True to generate warnings for variables that could be declared
1163    --  as constants. Modified by use of -gnatwk/K.
1164
1165    Warn_On_Deleted_Code : Boolean := False;
1166    --  GNAT
1167    --  Set to True to generate warnings for code deleted by the front end
1168    --  for conditional statements whose outcome is known at compile time.
1169    --  Modified by use of -gnatwt/T.
1170
1171    Warn_On_Dereference : Boolean := False;
1172    --  GNAT
1173    --  Set to True to generate warnings for implicit dereferences for array
1174    --  indexing and record component access. Modified by use of -gnatwd/D.
1175
1176    Warn_On_Export_Import : Boolean := True;
1177    --  GNAT
1178    --  Set to True to generate warnings for suspicious use of export or
1179    --  import pragmas. Modified by use of -gnatwx/X.
1180
1181    Warn_On_Hiding : Boolean := False;
1182    --  GNAT
1183    --  Set to True to generate warnings if a declared entity hides another
1184    --  entity. The default is that this warning is suppressed.
1185
1186    Warn_On_Modified_Unread : Boolean := False;
1187    --  GNAT
1188    --  Set to True to generate warnings if a variable is assigned but is never
1189    --  read. The default is that this warning is suppressed. Also controls
1190    --  warnings about assignments whose value is never read.
1191
1192    Warn_On_No_Value_Assigned : Boolean := True;
1193    --  GNAT
1194    --  Set to True to generate warnings if no value is ever assigned to a
1195    --  variable that is at least partially uninitialized. Set to false to
1196    --  suppress such warnings. The default is that such warnings are enabled.
1197
1198    Warn_On_Non_Local_Exception : Boolean := False;
1199    --  GNAT
1200    --  Set to True to generate warnings for non-local exception raises and also
1201    --  handlers that can never handle a local raise. This warning is only ever
1202    --  generated if pragma Restrictions (No_Exception_Propagation) is set. The
1203    --  default is not to generate the warnings even if the restriction is set.
1204
1205    Warn_On_Obsolescent_Feature : Boolean := False;
1206    --  GNAT
1207    --  Set to True to generate warnings on use of any feature in Annex or if a
1208    --  subprogram is called for which a pragma Obsolescent applies.
1209
1210    Warn_On_Questionable_Missing_Parens : Boolean := True;
1211    --  GNAT
1212    --  Set to True to generate warnings for cases where parenthese are missing
1213    --  and the usage is questionable, because the intent is unclear.
1214
1215    Warn_On_Redundant_Constructs : Boolean := False;
1216    --  GNAT
1217    --  Set to True to generate warnings for redundant constructs (e.g. useless
1218    --  assignments/conversions). The default is that this warning is disabled.
1219
1220    Warn_On_Object_Renames_Function : Boolean := False;
1221    --  GNAT
1222    --  Set to True to generate warnings when a function result is renamed as
1223    --  an object. The default is that this warning is disabled.
1224
1225    Warn_On_Reverse_Bit_Order : Boolean := True;
1226    --  GNAT
1227    --  Set to True to generate warning (informational) messages for component
1228    --  clauses that are affected by non-standard bit-order. The default is
1229    --  that this warning is enabled.
1230
1231    Warn_On_Unchecked_Conversion : Boolean := True;
1232    --  GNAT
1233    --  Set to True to generate warnings for unchecked conversions that may have
1234    --  non-portable semantics (e.g. because sizes of types differ). The default
1235    --  is that this warning is enabled.
1236
1237    Warn_On_Unrecognized_Pragma : Boolean := True;
1238    --  GNAT
1239    --  Set to True to generate warnings for unrecognized pragmas. The default
1240    --  is that this warning is enabled.
1241
1242    Warn_On_Unrepped_Components : Boolean := False;
1243    --  GNAT
1244    --  Set to True to generate warnings for the case of components of record
1245    --  which have a record representation clause but this component does not
1246    --  have a component clause. The default is that this warning is disabled.
1247
1248    type Warning_Mode_Type is (Suppress, Normal, Treat_As_Error);
1249    Warning_Mode : Warning_Mode_Type := Normal;
1250    --  GNAT, GNATBIND
1251    --  Controls treatment of warning messages. If set to Suppress, warning
1252    --  messages are not generated at all. In Normal mode, they are generated
1253    --  but do not count as errors. In Treat_As_Error mode, warning messages
1254    --  are generated and are treated as errors.
1255
1256    Wide_Character_Encoding_Method : WC_Encoding_Method := WCEM_Brackets;
1257    --  GNAT
1258    --  Method used for encoding wide characters in the source program. See
1259    --  description of type in unit System.WCh_Con for a list of the methods
1260    --  that are currently supported. Note that brackets notation is always
1261    --  recognized in source programs regardless of the setting of this
1262    --  variable. The default setting causes only the brackets notation to be
1263    --  recognized. If this is the main unit, this setting also controls the
1264    --  output of the W=? parameter in the ALI file, which is used to provide
1265    --  the default for Wide_Text_IO files.
1266
1267    Xref_Active : Boolean := True;
1268    --  GNAT
1269    --  Set if cross-referencing is enabled (i.e. xref info in ALI files)
1270
1271    Zero_Formatting : Boolean := False;
1272    --  GNATBIND
1273    --  Do no formatting (no title, no leading spaces, no empty lines) in
1274    --  auxiliary outputs (-e, -K, -l, -R).
1275
1276    ----------------------------
1277    -- Configuration Settings --
1278    ----------------------------
1279
1280    --  These are settings that are used to establish the mode at the start of
1281    --  each unit. The values defined below can be affected either by command
1282    --  line switches, or by the use of appropriate configuration pragmas in the
1283    --  gnat.adc file.
1284
1285    Ada_Version_Config : Ada_Version_Type;
1286    --  GNAT
1287    --  This is the value of the configuration switch for the Ada 83 mode, as
1288    --  set by the command line switches -gnat83/95/05, and possibly modified by
1289    --  the use of configuration pragmas Ada_83/Ada95/Ada05. This switch is used
1290    --  to set the initial value for Ada_Version mode at the start of analysis
1291    --  of a unit. Note however, that the setting of this flag is ignored for
1292    --  internal and predefined units (which are always compiled in the most up
1293    --  to date version of Ada).
1294
1295    Ada_Version_Explicit_Config : Ada_Version_Type;
1296    --  GNAT
1297    --  This is set in the same manner as Ada_Version_Config. The difference is
1298    --  that the setting of this flag is not ignored for internal and predefined
1299    --  units, which for some purposes do indeed access this value, regardless
1300    --  of the fact that they are compiled the the most up to date ada version).
1301
1302    Assertions_Enabled_Config : Boolean;
1303    --  GNAT
1304    --  This is the value of the configuration switch for assertions enabled
1305    --  mode, as possibly set by the command line switch -gnata, and possibly
1306    --  modified by the use of the configuration pragma Assertion_Policy.
1307
1308    Debug_Pragmas_Enabled_Config : Boolean;
1309    --  GNAT
1310    --  This is the value of the configuration switch for debug pragmas enabled
1311    --  mode, as possibly set by the command line switch -gnata and possibly
1312    --  modified by the use of the configuration pragma Debug_Policy.
1313
1314    Dynamic_Elaboration_Checks_Config : Boolean := False;
1315    --  GNAT
1316    --  Set True for dynamic elaboration checking mode, as set by the -gnatE
1317    --  switch or by the use of pragma Elaboration_Checking (Dynamic).
1318
1319    Exception_Locations_Suppressed_Config : Boolean := False;
1320    --  GNAT
1321    --  Set True by use of the configuration pragma Suppress_Exception_Messages
1322
1323    Extensions_Allowed_Config : Boolean;
1324    --  GNAT
1325    --  This is the flag that indicates whether extensions are allowed. It can
1326    --  be set True either by use of the -gnatX switch, or by use of the
1327    --  configuration pragma Extensions_Allowed (On). It is always set to True
1328    --  for internal GNAT units, since extensions are always permitted in such
1329    --  units.
1330
1331    External_Name_Exp_Casing_Config : External_Casing_Type;
1332    --  GNAT
1333    --  This is the value of the configuration switch that controls casing of
1334    --  external symbols for which an explicit external name is given. It can be
1335    --  set to Uppercase by the command line switch -gnatF, and further modified
1336    --  by the use of the configuration pragma External_Name_Casing in the
1337    --  gnat.adc file. This flag is used to set the initial value for
1338    --  External_Name_Exp_Casing at the start of analyzing each unit. Note
1339    --  however that the setting of this flag is ignored for internal and
1340    --  predefined units (which are always compiled with As_Is mode).
1341
1342    External_Name_Imp_Casing_Config : External_Casing_Type;
1343    --  GNAT
1344    --  This is the value of the configuration switch that controls casing of
1345    --  external symbols where the external name is implicitly given. It can be
1346    --  set to Uppercase by the command line switch -gnatF, and further modified
1347    --  by the use of the configuration pragma External_Name_Casing in the
1348    --  gnat.adc file. This flag is used to set the initial value for
1349    --  External_Name_Imp_Casing at the start of analyzing each unit. Note
1350    --  however that the setting of this flag is ignored for internal and
1351    --  predefined units (which are always compiled with Lowercase mode).
1352
1353    Persistent_BSS_Mode_Config : Boolean;
1354    --  GNAT
1355    --  This is the value of the configuration switch that controls whether
1356    --  potentially persistent data is to be placed in the persistent_bss
1357    --  section. It can be set True by use of the pragma Persistent_BSS.
1358    --  This flag is used to set the initial value of Persistent_BSS_Mode
1359    --  at the start of each compilation unit, except that it is always
1360    --  set False for predefined units.
1361
1362    Polling_Required_Config : Boolean;
1363    --  GNAT
1364    --  This is the value of the configuration switch that controls polling
1365    --  mode. It can be set True by the command line switch -gnatP, and then
1366    --  further modified by the use of pragma Polling in the gnat.adc file. This
1367    --  flag is used to set the initial value for Polling_Required at the start
1368    --  of analyzing each unit.
1369
1370    Use_VADS_Size_Config : Boolean;
1371    --  GNAT
1372    --  This is the value of the configuration switch that controls the use of
1373    --  VADS_Size instead of Size whereever the attribute Size is used. It can
1374    --  be set True by the use of the pragma Use_VADS_Size in the gnat.adc file.
1375    --  This flag is used to set the initial value for Use_VADS_Size at the
1376    --  start of analyzing each unit. Note however that the setting of this flag
1377    --  is ignored for internal and predefined units (which are always compiled
1378    --  with the standard Size semantics).
1379
1380    type Config_Switches_Type is private;
1381    --  Type used to save values of the switches set from Config values
1382
1383    procedure Save_Opt_Config_Switches (Save : out Config_Switches_Type);
1384    --  This procedure saves the current values of the switches which are
1385    --  initialized from the above Config values, and then resets these switches
1386    --  according to the Config value settings.
1387
1388    procedure Set_Opt_Config_Switches
1389      (Internal_Unit : Boolean;
1390       Main_Unit     : Boolean);
1391    --  This procedure sets the switches to the appropriate initial values. The
1392    --  parameter Internal_Unit is True for an internal or predefined unit, and
1393    --  affects the way the switches are set (see above). Main_Unit is true if
1394    --  switches are being set for the main unit (this affects setting of the
1395    --  assert/debug pragma switches, which are normally set false by default
1396    --  for an internal unit, except when the internal unit is the main unit,
1397    --  in which case we use the command line settings).
1398
1399    procedure Restore_Opt_Config_Switches (Save : Config_Switches_Type);
1400    --  This procedure restores a set of switch values previously saved by a
1401    --  call to Save_Opt_Switches.
1402
1403    procedure Register_Opt_Config_Switches;
1404    --  This procedure is called after processing the gnat.adc file to record
1405    --  the values of the Config switches, as possibly modified by the use of
1406    --  command line switches and configuration pragmas.
1407
1408    ------------------------
1409    -- Other Global Flags --
1410    ------------------------
1411
1412    Expander_Active : Boolean := False;
1413    --  A flag that indicates if expansion is active (True) or deactivated
1414    --  (False). When expansion is deactivated all calls to expander routines
1415    --  have no effect. Note that the initial setting of False is merely to
1416    --  prevent saving of an undefined value for an initial call to the
1417    --  Expander_Mode_Save_And_Set procedure. For more information on the use of
1418    --  this flag, see package Expander. Indeed this flag might more logically
1419    --  be in the spec of Expander, but it is referenced by Errout, and it
1420    --  really seems wrong for Errout to depend on Expander.
1421
1422    Static_Dispatch_Tables : Boolean := True;
1423    --  This flag indicates if the backend supports generation of statically
1424    --  allocated dispatch tables. If it is True, then the front end will
1425    --  generate static aggregates for dispatch tables that contain forward
1426    --  references to addresses of subprograms not seen yet, and the back end
1427    --  must be prepared to handle this case. If it is False, then the front
1428    --  end generates assignments to initialize the dispatch table, and there
1429    --  are no such forward references. By default we build statically allocated
1430    --  dispatch tables for all library level tagged types in all platforms.This
1431    --  behavior can be disabled using switch -gnatd.t which will set this flag
1432    --  to False and revert to the previous dynamic behavior.
1433
1434    -----------------------
1435    -- Tree I/O Routines --
1436    -----------------------
1437
1438    procedure Tree_Read;
1439    --  Reads switch settings from current tree file using Tree_Read
1440
1441    procedure Tree_Write;
1442    --  Writes out switch settings to current tree file using Tree_Write
1443
1444    --------------------------
1445    -- ASIS Version Control --
1446    --------------------------
1447
1448    --  These two variables (Tree_Version_String and Tree_ASIS_Version_Number)
1449    --  are supposed to be used in the GNAT/ASIS version check performed in
1450    --  the ASIS code (this package is also a part of the ASIS implementation).
1451    --  They are set by Tree_Read procedure, so they represent the version
1452    --  number (and the version string) of the compiler which has created the
1453    --  tree, and they are supposed to be compared with the corresponding values
1454    --  from the Tree_IO and Gnatvsn packages which also are a part of ASIS
1455    --  implementation.
1456
1457    Tree_Version_String : String_Access;
1458    --  Used to store the compiler version string read from a tree file to check
1459    --  if it is from the same date as stored in the version string in Gnatvsn.
1460    --  We require that ASIS Pro can be used only with GNAT Pro, but we allow
1461    --  non-Pro ASIS and ASIS-based tools to be used with any version of the
1462    --  GNAT compiler. Therefore, we need the possibility to compare the dates
1463    --  of the corresponding source sets, using version strings that may be
1464    --  of different lengths.
1465
1466    Tree_ASIS_Version_Number : Int;
1467    --  Used to store the ASIS version number read from a tree file to check if
1468    --  it is the same as stored in the ASIS version number in Tree_IO.
1469
1470 private
1471
1472    --  The following type is used to save and restore settings of switches in
1473    --  Opt that represent the configuration (i.e. result of config pragmas).
1474
1475    --  Note that Ada_Version_Explicit is not included, since this is a sticky
1476    --  flag that once set does not get reset, since the whole idea of this flag
1477    --  is to record the setting for the main unit.
1478
1479    type Config_Switches_Type is record
1480       Ada_Version                    : Ada_Version_Type;
1481       Ada_Version_Explicit           : Ada_Version_Type;
1482       Assertions_Enabled             : Boolean;
1483       Debug_Pragmas_Enabled          : Boolean;
1484       Dynamic_Elaboration_Checks     : Boolean;
1485       Exception_Locations_Suppressed : Boolean;
1486       Extensions_Allowed             : Boolean;
1487       External_Name_Exp_Casing       : External_Casing_Type;
1488       External_Name_Imp_Casing       : External_Casing_Type;
1489       Persistent_BSS_Mode            : Boolean;
1490       Polling_Required               : Boolean;
1491       Use_VADS_Size                  : Boolean;
1492    end record;
1493
1494    --  The following declarations are for GCC version dependent flags. We do
1495    --  not let client code in the compiler test GCC_Version directly, but
1496    --  instead use deferred constants for relevant feature tags.
1497
1498    --  Note: there currently are no such constants defined in this section,
1499    --  since the compiler front end is currently entirely independent of the
1500    --  GCC version, which is a desirable state of affairs.
1501
1502    function get_gcc_version return Int;
1503    pragma Import (C, get_gcc_version, "get_gcc_version");
1504
1505    GCC_Version : constant Nat := get_gcc_version;
1506    --  GNATMAKE
1507    --  Indicates which version of gcc is in use (3 = 3.x, 4 = 4.x). Note that
1508    --  gcc 2.8.1 (which used to be a value of 2) is no longer supported.
1509
1510 end Opt;