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) 1992-2003, 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,  59 Temple Place - Suite 330,  Boston, --
  20 -- MA 02111-1307, 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
  35 --  routine from the command line and referenced throughout the compiler,
  36 --  the binder, gnatmake or other GNAT tools. The comments indicate which
  37 --  options are used by which programs (GNAT, GNATBIND, GNATMAKE, etc).
  38
  39 with Gnatvsn;  use Gnatvsn;
  40 with Hostparm; use Hostparm;
  41 with Types;    use Types;
  42
  43 with System.WCh_Con; use System.WCh_Con;
  44 with GNAT.Strings;   use GNAT.Strings;
  45
  46 package Opt is
  47
  48    ----------------------------------------------
  49    -- Settings of Modes for Current Processing --
  50    ----------------------------------------------
  51
  52    --  The following mode values represent the current state of processing.
  53    --  The values set here are the default values. Unless otherwise noted,
  54    --  the value may be reset in Switch with an appropropiate switch. In
  55    --  some cases, the values can also be modified by pragmas, and in the
  56    --  case of some binder variables, Gnatbind.Scan_Bind_Arg may modify
  57    --  the default values.
  58
  59    Ada_Bind_File : Boolean := True;
  60    --  GNATBIND, GNATLINK
  61    --  Set True if binder file to be generated in Ada rather than C
  62
  63    Ada_95 : Boolean := True;
  64    --  GNAT
  65    --  Set True if operating in Ada 95 mode
  66    --  Set False if operating in Ada 83 mode
  67
  68    Ada_83 : Boolean := False;
  69    --  GNAT
  70    --  Set True if operating in Ada 83 mode
  71    --  Set False if operating in Ada 95 mode
  72
  73    Ada_Final_Suffix : constant String := "final";
  74    Ada_Final_Name : String_Ptr := new String'("ada" & Ada_Final_Suffix);
  75    --  GNATBIND
  76    --  The name of the procedure that performs the finalization at the end of
  77    --  execution. This variable may be modified by Gnatbind.Scan_Bind_Arg.
  78
  79    Ada_Init_Suffix : constant String := "init";
  80    Ada_Init_Name : String_Ptr := new String'("ada" & Ada_Init_Suffix);
  81    --  GNATBIND
  82    --  The name of the procedure that performs initialization at the start
  83    --  of execution. This variable may be modified by Gnatbind.Scan_Bind_Arg.
  84
  85    Ada_Main_Name_Suffix : constant String := "main";
  86    --  GNATBIND
  87    --  The suffix for Ada_Main_Name. Defined as a constant here so that it
  88    --  can be referenced in a uniform manner to create either the default
  89    --  value of Ada_Main_Name (declared below), or the non-default name
  90    --  set by Gnatbind.Scan_Bind_Arg.
  91
  92    Ada_Main_Name : String_Ptr := new String'("ada_" & Ada_Main_Name_Suffix);
  93    --  GNATBIND
  94    --  The name of the Ada package generated by the binder (when in Ada mode).
  95    --  This variable may be modified by Gnatbind.Scan_Bind_Arg.
  96
  97    Address_Clause_Overlay_Warnings : Boolean := True;
  98    --  GNAT
  99    --  Set False to disable address clause warnings
 100
 101    All_Errors_Mode : Boolean := False;
 102    --  GNAT
 103    --  Flag set to force display of multiple errors on a single line and
 104    --  also repeated error messages for references to undefined identifiers
 105    --  and certain other repeated error messages.
 106
 107    All_Sources : Boolean := False;
 108    --  GNATBIND
 109    --  Set to True to require all source files to be present. This flag is
 110    --  directly modified by gnatmake to affect the shared binder routines.
 111
 112    Alternate_Main_Name : String_Ptr := null;
 113    --  GNATBIND
 114    --  Set to non null when Bind_Alternate_Main_Name is True. This value
 115    --  is modified as needed by Gnatbind.Scan_Bind_Arg.
 116
 117    Assertions_Enabled : Boolean := False;
 118    --  GNAT
 119    --  Enable assertions made using pragma Assert.
 120
 121    ASIS_Mode : Boolean := False;
 122    --  GNAT
 123    --  Enable semantic checks and tree transformations that are important
 124    --  for ASIS but that are usually skipped if Operating_Mode is set to
 125    --  Check_Semantics. This flag does not have the corresponding option to set
 126    --  it ON. It is set ON when Tree_Output is set ON, it can also be set ON
 127    --  from the code of GNSA-based tool (a client may need to set ON the
 128    --  Back_Annotate_Rep_Info flag in this case. At the moment this does not
 129    --  make very much sense, because GNSA can not do back annotation).
 130
 131    Back_Annotate_Rep_Info : Boolean := False;
 132    --  GNAT
 133    --  If set True, enables back annotation of representation information
 134    --  by gigi, even in -gnatc mode. This is set True by the use of -gnatR
 135    --  (list representation information) or -gnatt (generate tree). It is
 136    --  also set true if certain Unchecked_Conversion instantiations require
 137    --  checking based on annotated values.
 138
 139    Bind_Alternate_Main_Name : Boolean := False;
 140    --  GNATBIND
 141    --  True if main should be called Alternate_Main_Name.all.
 142    --  This variable may be set to True by Gnatbind.Scan_Bind_Arg.
 143
 144    Bind_Main_Program : Boolean := True;
 145    --  GNATBIND
 146    --  Set to False if not binding main Ada program.
 147
 148    Bind_For_Library : Boolean := False;
 149    --  GNATBIND
 150    --  Set to True if the binder needs to generate a file designed for
 151    --  building a library. May be set to True by Gnatbind.Scan_Bind_Arg.
 152
 153    Bind_Only : Boolean := False;
 154    --  GNATMAKE
 155    --  Set to True to skip compile and link steps
 156    --  (except when Compile_Only and/or Link_Only are True).
 157
 158    Blank_Deleted_Lines : Boolean := False;
 159    --  GNAT, GNATPREP
 160    --  Output empty lines for each line of preprocessed input that is deleted
 161    --  in the output, including preprocessor lines starting with a '#'.
 162
 163    Brief_Output : Boolean := False;
 164    --  GNAT, GNATBIND
 165    --  Force brief error messages to standard error, even if verbose mode is
 166    --  set (so that main error messages go to standard output).
 167
 168    Check_Object_Consistency : Boolean := False;
 169    --  GNATBIND, GNATMAKE
 170    --  Set to True to check whether every object file is consistent with
 171    --  its corresponding ada library information (ALI) file. An object
 172    --  file is inconsistent with the corresponding ALI file if the object
 173    --  file does not exist or if it has an older time stamp than the ALI file.
 174    --  Default above is for GNATBIND. GNATMAKE overrides this default to
 175    --  True (see Make.Initialize) since we normally do need to check source
 176    --  consistencies in gnatmake.
 177
 178    Check_Only : Boolean := False;
 179    --  GNATBIND
 180    --  Set to True to do checks only, no output of binder file.
 181
 182    Check_Readonly_Files : Boolean := False;
 183    --  GNATMAKE
 184    --  Set to True to check readonly files during the make process.
 185
 186    Check_Source_Files : Boolean := True;
 187    --  GNATBIND, GNATMAKE
 188    --  Set to True to enable consistency checking for any source files that
 189    --  are present (i.e. date must match the date in the library info file).
 190    --  Set to False for object file consistency check only. This flag is
 191    --  directly modified by gnatmake, to affect the shared binder routines.
 192
 193    Check_Switches : Boolean := False;
 194    --  GNATMAKE
 195    --  Set to True to check compiler options during the make process.
 196
 197    Check_Unreferenced : Boolean := False;
 198    --  GNAT
 199    --  Set to True to enable checking for unreferenced entities other
 200    --  than formal parameters (for which see Check_Unreferenced_Formals)
 201
 202    Check_Unreferenced_Formals : Boolean := False;
 203    --  GNAT
 204    --  Set True to check for unreferenced formals. This is turned
 205    --  on by -gnatwa/wf/wu and turned off by -gnatwA/wF/wU.
 206
 207    Check_Withs : Boolean := False;
 208    --  GNAT
 209    --  Set to True to enable checking for unused withs, and also the case
 210    --  of withing a package and using none of the entities in the package.
 211
 212    Comment_Deleted_Lines : Boolean := False;
 213    --  GNATPREP
 214    --  True if source lines removed by the preprocessor should be commented
 215    --  in the output file.
 216
 217    Compile_Only : Boolean := False;
 218    --  GNATMAKE, GNATCLEAN
 219    --  GNATMAKE: set to True to skip bind and link steps (except when
 220    --            Bind_Only is True).
 221    --  GNATCLEAN: set to True to only the files produced by the compiler are to
 222    --             be deleted, but not the library files or executable files.
 223
 224    Config_File : Boolean := True;
 225    --  GNAT
 226    --  Set to False to inhibit reading and processing of gnat.adc file
 227
 228    Config_File_Names : String_List_Access := null;
 229    --  GNAT
 230    --  Names of configuration pragmas files (given by switches -gnatec)
 231
 232    Configurable_Run_Time_Mode : Boolean := False;
 233    --  GNAT, GNATBIND
 234    --  Set True if the compiler is operating in configurable run-time mode.
 235    --  This happens if the flag Targparm.Configurable_Run_TimeMode_On_Target
 236    --  is set True, or if pragma No_Run_Time is used. See the spec of Rtsfind
 237    --  for details on the handling of the latter pragma.
 238
 239    Constant_Condition_Warnings : Boolean := False;
 240    --  GNAT
 241    --  Set to True to activate warnings on constant conditions
 242
 243    Create_Mapping_File : Boolean := False;
 244    --  GNATMAKE
 245    --  Set to True (-C switch) to indicate that gnatmake
 246    --  invokes the compiler with a mapping file (-gnatem compiler switch).
 247
 248    subtype Debug_Level_Value is Nat range 0 .. 3;
 249    Debugger_Level : Debug_Level_Value := 0;
 250    --  GNATBIND
 251    --  The value given to the -g parameter.
 252    --  The default value for -g with no value is 2
 253    --  This is usually ignored by GNATBIND, except in the VMS version
 254    --  where it is passed as an argument to __gnat_initialize to trigger
 255    --  the activation of the remote debugging interface (is this true???).
 256
 257    Debug_Generated_Code : Boolean := False;
 258    --  GNAT
 259    --  Set True (-gnatD switch) to debug generated expanded code instead
 260    --  of the original source code. Causes debugging information to be
 261    --  written with respect to the generated code file that is written.
 262
 263    Display_Compilation_Progress : Boolean := False;
 264    --  GNATMAKE
 265    --  Set True (-d switch) to display information on progress while compiling
 266    --  files. Internal flag to be used in conjunction with an IDE such as
 267    --  Glide.
 268
 269    type Distribution_Stub_Mode_Type is
 270    --  GNAT
 271      (No_Stubs,
 272       --  Normal mode, no generation/compilation of distribution stubs
 273
 274       Generate_Receiver_Stub_Body,
 275       --  The unit being compiled is the RCI body, and the compiler will
 276       --  generate the body for the receiver stubs and compile it.
 277
 278       Generate_Caller_Stub_Body);
 279       --  The unit being compiled is the RCI spec, and the compiler will
 280       --  generate the body for the caller stubs and compile it.
 281
 282    Distribution_Stub_Mode : Distribution_Stub_Mode_Type := No_Stubs;
 283    --  GNAT
 284    --  This enumeration variable indicates the five states of distribution
 285    --  annex stub generation/compilation.
 286
 287    Do_Not_Execute : Boolean := False;
 288    --  GNATMAKE
 289    --  Set to True if no actual compilations should be undertaken.
 290
 291    Dynamic_Elaboration_Checks : Boolean := False;
 292    --  GNAT
 293    --  Set True for dynamic elaboration checking mode, as set by the -gnatE
 294    --  switch or by the use of pragma Elaboration_Checks (Dynamic).
 295
 296    Elab_Dependency_Output : Boolean := False;
 297    --  GNATBIND
 298    --  Set to True to output complete list of elaboration constraints
 299
 300    Elab_Order_Output : Boolean := False;
 301    --  GNATBIND
 302    --  Set to True to output chosen elaboration order
 303
 304    Elab_Warnings : Boolean := False;
 305    --  GNAT
 306    --  Set to True to generate full elaboration warnings (-gnatwl)
 307
 308    Enable_Overflow_Checks : Boolean := False;
 309    --  GNAT
 310    --  Set to True if -gnato (enable overflow checks) switch is set,
 311    --  but not -gnatp.
 312
 313    Exception_Locations_Suppressed : Boolean := False;
 314    --  GNAT
 315    --  This flag is set True if a Suppress_Exception_Locations configuration
 316    --  pragma is currently active.
 317
 318    type Exception_Mechanism_Type is
 319    --  Determines the handling of exceptions. See Exp_Ch11 for details
 320    --
 321      (Front_End_Setjmp_Longjmp_Exceptions,
 322       --  Exceptions use setjmp/longjmp generated explicitly by the
 323       --  front end (this includes gigi or other equivalent parts of
 324       --  the code generator). AT END handlers are converted into
 325       --  exception handlers by the front end in this mode.
 326
 327       Front_End_ZCX_Exceptions,
 328       --  Exceptions use the zero cost table mechanism with explicit
 329       --  tables and exception regions generated by the front end.
 330       --  AT END handlers are converted into exception handlers by
 331       --  the front end in this mode.
 332
 333       Back_End_ZCX_Exceptions);
 334       --  Exceptions are handled by the back end. The front end simply
 335       --  generates the handlers as they appear in the source, and AT
 336       --  END handlers are left untouched (they are not converted into
 337       --  exception handlers when operating in this mode. Note that the
 338       --  name includes ZCX, since the expectation is that the back end
 339       --  mechanism will in fact be a ZCX approach, but nothing in the
 340       --  compiler depends on this, so for example if GNAT is run with
 341       --  a version of GCC configured for setjmp/longjmp exception handling,
 342       --  then everything will work fine.
 343    pragma Convention (C, Exception_Mechanism_Type);
 344
 345    Exception_Mechanism : Exception_Mechanism_Type :=
 346                            Front_End_Setjmp_Longjmp_Exceptions;
 347    --  GNAT
 348    --  Set to the appropriate value depending on the default as given in
 349    --  system.ads (ZCX_By_Default, GCC_ZCX_Support, Front_End_ZCX_Support)
 350    --  and the use of -gnatL -gnatZ (and -gnatdX). The C convention is
 351    --  there to make this variable accessible to gigi.
 352
 353    Exception_Tracebacks : Boolean := False;
 354    --  GNATBIND
 355    --  Set to True to store tracebacks in exception occurrences (-E)
 356
 357    Extensions_Allowed : Boolean := False;
 358    --  GNAT
 359    --  Set to True by switch -gnatX if GNAT specific language extensions
 360    --  are allowed. For example, "with type" is a GNAT extension.
 361
 362    type External_Casing_Type is (
 363      As_Is,       -- External names cased as they appear in the Ada source
 364      Uppercase,   -- External names forced to all uppercase letters
 365      Lowercase);  -- External names forced to all lowercase letters
 366
 367    External_Name_Imp_Casing : External_Casing_Type := Lowercase;
 368    --  GNAT
 369    --  The setting of this flag determines the casing of external names
 370    --  when the name is implicitly derived from an entity name (i.e. either
 371    --  no explicit External_Name or Link_Name argument is used, or, in the
 372    --  case of extended DEC pragmas, the external name is given using an
 373    --  identifier. The As_Is setting is not permitted here (since this would
 374    --  create Ada source programs that were case sensitive).
 375
 376    External_Name_Exp_Casing : External_Casing_Type := As_Is;
 377    --  GNAT
 378    --  The setting of this flag determines the casing of an external name
 379    --  specified explicitly with a string literal. As_Is means the string
 380    --  literal is used as given with no modification to the casing. If
 381    --  Lowercase or Uppercase is set, then the string is forced to all
 382    --  lowercase or all uppercase letters as appropriate. Note that this
 383    --  setting has no effect if the external name is given using an identifier
 384    --  in the case of extended DEC import/export pragmas (in this case the
 385    --  casing is controlled by External_Name_Imp_Casing), and also has no
 386    --  effect if an explicit Link_Name is supplied (a link name is always
 387    --  used exactly as given).
 388
 389    Float_Format : Character := ' ';
 390    --  GNAT
 391    --  A non-blank value indicates that a Float_Format pragma has been
 392    --  processed, in which case this variable is set to 'I' for IEEE or
 393    --  to 'V' for VAX. The setting of 'V' is only possible on OpenVMS
 394    --  versions of GNAT.
 395
 396    Float_Format_Long : Character := ' ';
 397    --  GNAT
 398    --  A non-blank value indicates that a Long_Float pragma has been
 399    --  processed (this pragma is recognized only in OpenVMS versions
 400    --  of GNAT), in which case this variable is set to D or G for
 401    --  D_Float or G_Float.
 402
 403    Force_ALI_Tree_File : Boolean := False;
 404    --  GNAT
 405    --  Force generation of ALI file even if errors are encountered.
 406    --  Also forces generation of tree file if -gnatt is also set.
 407
 408    Force_Checking_Of_Elaboration_Flags : Boolean := False;
 409    --  GNATBIND
 410    --  True if binding with forced checking of the elaboration flags
 411    --  (-F switch set).
 412
 413    Force_Compilations : Boolean := False;
 414    --  GNATMAKE
 415    --  Set to force recompilations even when the objects are up-to-date.
 416
 417    Force_RM_Elaboration_Order : Boolean := False;
 418    --  GNATBIND
 419    --  True if binding with forced RM elaboration order (-f switch set)
 420    --  Note: this is considered an obsolescent option, to be removed in
 421    --  some future release. It is no longer documented. The proper way
 422    --  to get this effect is to use -gnatE and suppress elab checks.
 423
 424    Full_Path_Name_For_Brief_Errors : Boolean := False;
 425    --  GNAT, GNATMAKE, GNATCLEAN
 426    --  When True, in Brief_Output mode, each error message line
 427    --  will start with the full path name of the source.
 428    --  When False, only the file name without directory information
 429    --  is used.
 430
 431    Full_List : Boolean := False;
 432    --  GNAT
 433    --  Set True to generate full source listing with embedded errors
 434
 435    Global_Discard_Names : Boolean := False;
 436    --  GNAT, GNATBIND
 437    --  Set true if a pragma Discard_Names applies to the current unit
 438
 439    GNAT_Mode : Boolean := False;
 440    --  GNAT
 441    --  True if compiling in GNAT system mode (-gnatg switch)
 442
 443    HLO_Active : Boolean := False;
 444    --  GNAT
 445    --  True if High Level Optimizer is activated (-gnatH switch)
 446
 447    Implementation_Unit_Warnings : Boolean := True;
 448    --  GNAT
 449    --  Set True to active warnings for use of implementation internal units.
 450    --  Can be controlled by use of -gnatwi/-gnatwI.
 451
 452    Identifier_Character_Set : Character;
 453    --  GNAT
 454    --  This variable indicates the character set to be used for identifiers.
 455    --  The possible settings are:
 456    --    '1'  Latin-5 (ISO-8859-1)
 457    --    '2'  Latin-5 (ISO-8859-2)
 458    --    '3'  Latin-5 (ISO-8859-3)
 459    --    '4'  Latin-5 (ISO-8859-4)
 460    --    '5'  Latin-5 (ISO-8859-5, Cyrillic)
 461    --    '9'  Latin-5 (ISO-8859-9)
 462    --    'p'  PC (US, IBM page 437)
 463    --    '8'  PC (European, IBM page 850)
 464    --    'f'  Full upper set (all distinct)
 465    --    'n'  No upper characters (Ada/83 rules)
 466    --    'w'  Latin-1 plus wide characters allowed in identifiers
 467    --
 468    --  The setting affects the set of letters allowed in identifiers and the
 469    --  upper/lower case equivalences. It does not affect the interpretation of
 470    --  character and string literals, which are always stored using the actual
 471    --  coding in the source program. This variable is initialized to the
 472    --  default value appropriate to the system (in Osint.Initialize), and then
 473    --  reset if a command line switch is used to change the setting.
 474
 475    Ineffective_Inline_Warnings : Boolean := False;
 476    --  GNAT
 477    --  Set True to activate warnings if front-end inlining (-gnatN) is not
 478    --  able to actually inline a particular call (or all calls). Can be
 479    --  controlled by use of -gnatwp/-gnatwP.
 480
 481    Init_Or_Norm_Scalars : Boolean := False;
 482    --  GNAT, GANTBIND
 483    --  Set True if a pragma Initialize_Scalars applies to the current unit.
 484    --  Also set True if a pragma Normalize_Scalars applies.
 485
 486    Initialize_Scalars : Boolean := False;
 487    --  GNAT
 488    --  Set True if a pragma Initialize_Scalars applies to the current unit.
 489    --  Note that Init_Or_Norm_Scalars is also set to True if this is True.
 490
 491    Initialize_Scalars_Mode1 : Character := 'I';
 492    Initialize_Scalars_Mode2 : Character := 'N';
 493    --  GNATBIND
 494    --  Set to two characters from -S switch (IN/LO/HI/EV/xx). The default
 495    --  is IN (invalid values), used if no -S switch is used.
 496
 497    Inline_Active : Boolean := False;
 498    --  GNAT
 499    --  Set True to activate pragma Inline processing across modules. Default
 500    --  for now is not to inline across module boundaries.
 501
 502    Interface_Library_Unit : Boolean := False;
 503    --  GNATBIND
 504    --  Set to True to indicate that at least one ALI file is an interface ALI:
 505    --  then elaboration flag checks are to be generated in the binder
 506    --  generated file.
 507
 508    Front_End_Inlining : Boolean := False;
 509    --  GNAT
 510    --  Set True to activate inlining by front-end expansion.
 511
 512    Inline_Processing_Required : Boolean := False;
 513    --  GNAT
 514    --  Set True if inline processing is required. Inline processing is
 515    --  required if an active Inline pragma is processed. The flag is set
 516    --  for a pragma Inline or Inline_Always that is actually active.
 517
 518    In_Place_Mode : Boolean := False;
 519    --  GNATMAKE
 520    --  Set True to store ALI and object files in place ie in the object
 521    --  directory if these files already exist or in the source directory
 522    --  if not.
 523
 524    Keep_Going : Boolean := False;
 525    --  GNATMAKE
 526    --  When True signals gnatmake to ignore compilation errors and keep
 527    --  processing sources until there is no more work.
 528
 529    Link_Only : Boolean := False;
 530    --  GNATMAKE
 531    --  Set to True to skip compile and bind steps
 532    --  (except when Bind_Only is set to True).
 533
 534    List_Restrictions : Boolean := False;
 535    --  GNATBIND
 536    --  Set to True to list restrictions pragmas that could apply to partition
 537
 538    List_Units : Boolean := False;
 539    --  GNAT
 540    --  List units in the active library for a compilation (-gnatu switch)
 541
 542    List_Dependencies : Boolean := False;
 543    --  GNATMAKE
 544    --  When True gnatmake verifies that the objects are up to date and
 545    --  outputs the list of object dependencies (-M switch).
 546    --  Output depends if -a switch is used or not.
 547    --  This list can be used directly in a Makefile.
 548
 549    List_Representation_Info : Int range 0 .. 3 := 0;
 550    --  GNAT
 551    --  Set non-zero by -gnatR switch to list representation information.
 552    --  The settings are as follows:
 553    --
 554    --    0 = no listing of representation information (default as above)
 555    --    1 = list rep info for user defined record and array types
 556    --    2 = list rep info for all user defined types and objects
 557    --    3 = like 2, but variable fields are decoded symbolically
 558
 559    List_Representation_Info_To_File : Boolean := False;
 560    --  GNAT
 561    --  Set true by -gnatRs switch. Causes information from -gnatR/1/2/3
 562    --  to be written to file.rep (where file is the name of the source
 563    --  file) instead of stdout. For example, if file x.adb is compiled
 564    --  using -gnatR2s then representation info is written to x.adb.ref.
 565
 566    List_Representation_Info_Mechanisms : Boolean := False;
 567    --  GNAT
 568    --  Set true by -gnatRm switch. Causes information on mechanisms to
 569    --  be included in the representation output information.
 570
 571    List_Preprocessing_Symbols : Boolean := False;
 572    --  GNAT, GNATPREP
 573    --  Set to True if symbols for preprocessing a source are to be listed
 574    --  before preprocessing occurs. Set to True by switch -s of gnatprep
 575    --  or -s in preprocessing data file for the compiler.
 576
 577    type Creat_Repinfo_File_Proc is access procedure (Src : File_Name_Type);
 578    type Write_Repinfo_Line_Proc is access procedure (Info : String);
 579    type Close_Repinfo_File_Proc is access procedure;
 580    --  Types used for procedure addresses below
 581
 582    Creat_Repinfo_File_Access : Creat_Repinfo_File_Proc := null;
 583    Write_Repinfo_Line_Access : Write_Repinfo_Line_Proc := null;
 584    Close_Repinfo_File_Access : Close_Repinfo_File_Proc := null;
 585    --  GNAT
 586    --  These three locations are left null when operating in non-compiler
 587    --  (e.g. ASIS mode), but when operating in compiler mode, they are
 588    --  set to point to the three corresponding procedures in Osint. The
 589    --  reason for this slightly strange interface is to prevent Repinfo
 590    --  from dragging in Osint in ASIS mode, which would include a lot of
 591    --  unwanted units in the ASIS build.
 592
 593    Locking_Policy : Character := ' ';
 594    --  GNAT, GNATBIND
 595    --  Set to ' ' for the default case (no locking policy specified).
 596    --  Reset to first character (uppercase) of locking policy name if a
 597    --  valid pragma Locking_Policy is encountered.
 598
 599    Locking_Policy_Sloc : Source_Ptr := No_Location;
 600    --  GNAT, GNATBIND
 601    --  Remember location of previous Locking_Policy pragma. This is used
 602    --  for inconsistency error messages. A value of System_Location is
 603    --  used if the policy is set in package System.
 604
 605    Look_In_Primary_Dir : Boolean := True;
 606    --  GNAT, GNATBIND, GNATMAKE, GNATCLEAN
 607    --  Set to False if a -I- was present on the command line.
 608    --  When True we are allowed to look in the primary directory to locate
 609    --  other source or library files.
 610
 611    Make_Steps : Boolean := False;
 612    --  GNATMAKE
 613    --  Set to True when either Compile_Only, Bind_Only or Link_Only is
 614    --  set to True.
 615
 616    Mapping_File_Name : String_Ptr := null;
 617    --  GNAT
 618    --  File name of mapping between unit names, file names and path names.
 619    --  (given by switch -gnatem)
 620
 621    Maximum_Errors : Int := 9999;
 622    --  GNAT, GNATBIND
 623    --  Maximum default number of errors before compilation is terminated.
 624    --  Can be overridden using -gnatm (GNAT) or -m (GNATBIND) switch.
 625
 626    Maximum_File_Name_Length : Int;
 627    --  GNAT, GNATBIND
 628    --  Maximum number of characters allowed in a file name, not counting the
 629    --  extension, as set by the appropriate switch. If no switch is given,
 630    --  then this value is initialized by Osint to the appropriate value.
 631
 632    Maximum_Processes : Positive := 1;
 633    --  GNATMAKE
 634    --  Maximum number of processes that should be spawned to carry out
 635    --  compilations.
 636
 637    Minimal_Recompilation : Boolean := False;
 638    --  GNATMAKE
 639    --  Set to True if minimal recompilation mode requested.
 640
 641    No_Stdlib : Boolean := False;
 642    --  GNATMAKE, GNATBIND, GNATFIND, GNATXREF
 643    --  Set to True if no default library search dirs added to search list.
 644
 645    No_Stdinc : Boolean := False;
 646    --  GNAT, GNATBIND, GNATMAKE, GNATFIND, GNATXREF
 647    --  Set to True if no default source search dirs added to search list.
 648
 649    No_Main_Subprogram : Boolean := False;
 650    --  GNATMAKE, GNATBIND
 651    --  Set to True if compilation/binding of a program without main
 652    --  subprogram requested.
 653
 654    No_Run_Time_Mode : Boolean := False;
 655    --  GNAT, GNATBIND
 656    --  This flag is set True if a No_Run_Time pragma is encountered. See
 657    --  spec of Rtsfind for a full description of handling of this pragma.
 658
 659    Normalize_Scalars : Boolean := False;
 660    --  GNAT, GNATBIND
 661    --  Set True if a pragma Normalize_Scalars applies to the current unit.
 662    --  Note that Init_Or_Norm_Scalars is also set to True if this is True.
 663
 664    Object_Directory_Present : Boolean := False;
 665    --  GNATMAKE
 666    --  Set to True when an object directory is specified with option -D
 667
 668    type Operating_Mode_Type is (Check_Syntax, Check_Semantics, Generate_Code);
 669    Operating_Mode : Operating_Mode_Type := Generate_Code;
 670    --  GNAT
 671    --  Indicates the operating mode of the compiler. The default is generate
 672    --  code, which runs the parser, semantics and backend. Switches can be
 673    --  used to set syntax checking only mode, or syntax and semantics checking
 674    --  only mode. Operating_Mode can also be modified as a result of detecting
 675    --  errors during the compilation process. In particular if any serious
 676    --  error is detected then this flag is reset from Generate_Code to
 677    --  Check_Semantics after generating an error message.
 678
 679    Original_Operating_Mode : Operating_Mode_Type := Generate_Code;
 680    --  GNAT
 681    --  Indicates the original operating mode of the compiler as set by
 682    --  compiler options. This is identical to Operating_Mode except that
 683    --  this is not affected by errors.
 684
 685    Optimization_Level : Int;
 686    pragma Import (C, Optimization_Level, "optimize");
 687    --  This constant reflects the optimization level (0,1,2 for -O0,-O1,-O2)
 688
 689    Output_File_Name_Present : Boolean := False;
 690    --  GNATBIND, GNAT, GNATMAKE
 691    --  Set to True when the output C file name is given with option -o
 692    --  for GNATBIND, when the object file name is given with option
 693    --  -gnatO for GNAT or when the executable is given with option -o
 694    --  for GNATMAKE.
 695
 696    Output_Linker_Option_List : Boolean := False;
 697    --  GNATBIND
 698    --  True if output of list of linker options is requested (-K switch set)
 699
 700    Output_Object_List : Boolean := False;
 701    --  GNATBIND
 702    --  True if output of list of objects is requested (-O switch set)
 703
 704    Pessimistic_Elab_Order : Boolean := False;
 705    --  GNATBIND
 706    --  True if pessimistic elaboration order is to be chosen (-p switch set)
 707
 708    Polling_Required : Boolean := False;
 709    --  GNAT
 710    --  Set to True if polling for asynchronous abort is enabled by using
 711    --  the -gnatP option for GNAT.
 712
 713    Preprocessing_Data_File : String_Ptr := null;
 714    --  GNAT
 715    --  Set by switch -gnatep=. The file name of the prepocessing data file.
 716
 717    Print_Generated_Code : Boolean := False;
 718    --  GNAT
 719    --  Set to True to enable output of generated code in source form. This
 720    --  flag is set by the -gnatG switch.
 721
 722    Print_Standard : Boolean := False;
 723    --  GNAT
 724    --  Set to true to enable printing of package standard in source form.
 725    --  This flag is set by the -gnatS switch
 726
 727    Propagate_Exceptions : Boolean := False;
 728    --  GNAT
 729    --  Indicates if subprogram descriptor exception tables should be
 730    --  built for imported subprograms. Set True if a Propagate_Exceptions
 731    --  pragma applies to the extended main unit.
 732
 733    type Usage is (Unknown, Not_In_Use, In_Use);
 734    Project_File_In_Use : Usage := Unknown;
 735    --  GNAT
 736    --  Indicates if a project file is used or not.
 737    --  Set to In_Use by the first SFNP pragma.
 738
 739    Queuing_Policy : Character := ' ';
 740    --  GNAT, GNATBIND
 741    --  Set to ' ' for the default case (no queuing policy specified).
 742    --  Reset to first character (uppercase) of locking policy name if a valid
 743    --  Queuing_Policy pragma is encountered.
 744
 745    Queuing_Policy_Sloc : Source_Ptr := No_Location;
 746    --  GNAT, GNATBIND
 747    --  Remember location of previous Queuing_Policy pragma. This is used
 748    --  for inconsistency error messages. A value of System_Location is
 749    --  used if the policy is set in package System.
 750
 751    Quiet_Output : Boolean := False;
 752    --  GNATMAKE, GNATCLEAN, GPR2MAKE
 753    --  Set to True if the tool should not have any output if there are no
 754    --  errors or warnings.
 755
 756    RTS_Lib_Path_Name : String_Ptr := null;
 757    RTS_Src_Path_Name : String_Ptr := null;
 758    --  GNAT
 759    --  Set to the "adalib" and "adainclude" directories of the run time
 760    --  specified by --RTS=.
 761
 762    RTS_Switch : Boolean := False;
 763    --  GNAT, GNATMAKE, GNATBIND, GNATLS, GNATFIND, GNATXREF
 764    --  Set to True when the --RTS switch is set
 765
 766    Run_Path_Option : Boolean := True;
 767    --  GNATMAKE, GNATLINK
 768    --  Set to False when no run_path_option should be issued to the linker
 769
 770    Shared_Libgnat : Boolean;
 771    --  GNATBIND
 772    --  Set to True if a shared libgnat is requested by using the -shared
 773    --  option for GNATBIND and to False when using the -static option. The
 774    --  value of this flag is set by Gnatbind.Scan_Bind_Arg.
 775
 776    Stack_Checking_Enabled : Boolean;
 777    --  GNAT
 778    --  Set to indicate if -fstack-check switch is set for the compilation.
 779    --  True means that the switch is set, so that stack checking is enabled.
 780    --  False means that the switch is not set (no stack checking). This
 781    --  value is obtained from the external imported value flag_stack_check
 782    --  in the gcc backend (see Frontend) and may be referenced throughout
 783    --  the compilation phases.
 784
 785    Style_Check : Boolean := False;
 786    --  GNAT
 787    --  Set True to perform style checks. Activates checks carried out
 788    --  in package Style (see body of this package for details of checks)
 789    --  This flag is set True by either the -gnatg or -gnaty switches.
 790
 791    System_Extend_Pragma_Arg : Node_Id := Empty;
 792    --  GNAT
 793    --  Set non-empty if and only if a correct Extend_System pragma was present
 794    --  in which case it points to the argument of the pragma, and the name can
 795    --  be located as Chars (Expression (System_Extend_Pragma_Arg)).
 796
 797    System_Extend_Unit : Node_Id := Empty;
 798    --  GNAT
 799    --  This is set to Empty if GNAT_Mode is set, since pragma Extend_System
 800    --  is never appropriate in GNAT_Mode (and causes troubles, including
 801    --  bogus circularities, if we try to compile the run-time library with
 802    --  a System extension). If GNAT_Mode is not set, then System_Extend_Unit
 803    --  is a copy of the value set in System_Extend_Pragma_Ary.
 804
 805    Subunits_Missing : Boolean := False;
 806    --  GNAT
 807    --  This flag is set true if missing subunits are detected with code
 808    --  generation active. This causes code generation to be skipped.
 809
 810    Suppress_Checks : Boolean := False;
 811    --  GNAT
 812    --  Set to True if -gnatp (suppress all checks) switch present.
 813
 814    Suppress_Options : Suppress_Array;
 815    --  GNAT
 816    --  Flags set True to suppress corresponding check, i.e. add an implicit
 817    --  pragma Suppress at the outer level of each unit compiled. Note that
 818    --  these suppress actions can be overridden by the use of the Unsuppress
 819    --  pragma. This variable is initialized by Osint.Initialize.
 820
 821    Suppress_Back_Annotation : Boolean := False;
 822    --  GNAT
 823    --  This flag is set True if back annotation of representation information
 824    --  is to be suppressed. This is set if neither -gnatt or -gnatR0-3 is set.
 825    --  This avoids unnecessary time being spent on back annotation.
 826
 827    Table_Factor : Int := 1;
 828    --  GNAT
 829    --  Factor by which all initial table sizes set in Alloc are multiplied.
 830    --  Used in Table to calculate initial table sizes (the initial table
 831    --  size is the value in Alloc, used as the Table_Initial parameter
 832    --  value, multiplied by the factor given here. The default value is
 833    --  used if no -gnatT switch appears.
 834
 835    Task_Dispatching_Policy : Character := ' ';
 836    --  GNAT, GNATBIND
 837    --  Set to ' ' for the default case (no task dispatching policy specified).
 838    --  Reset to first character (uppercase) of task dispatching policy name
 839    --  if a valid Task_Dispatching_Policy pragma is encountered.
 840
 841    Task_Dispatching_Policy_Sloc : Source_Ptr := No_Location;
 842    --  GNAT, GNATBIND
 843    --  Remember location of previous Task_Dispatching_Policy pragma. This is
 844    --  used for inconsistency error messages. A value of System_Location is
 845    --  used if the policy is set in package System.
 846
 847    Tasking_Used : Boolean := False;
 848    --  Set True if any tasking construct is encountered. Used to activate the
 849    --  output of the Q, L and T lines in ALI files.
 850
 851    Time_Slice_Set : Boolean := False;
 852    --  GNATBIND
 853    --  Set True if a pragma Time_Slice is processed in the main unit, or
 854    --  if the -gnatTnn switch is present to set a time slice value.
 855
 856    Time_Slice_Value : Nat;
 857    --  GNATBIND
 858    --  Time slice value. Valid only if Time_Slice_Set is True, i.e. if a
 859    --  Time_Slice pragma has been processed. Set to the time slice value
 860    --  in microseconds. Negative values are stored as zero, and the value
 861    --  is not larger than 1_000_000_000 (1000 seconds). Values larger than
 862    --  this are reset to this maximum. This can also be set with the -gnatTnn
 863    --  switch.
 864
 865    Tolerate_Consistency_Errors : Boolean := False;
 866    --  GNATBIND
 867    --  Tolerate time stamp and other consistency errors. If this flag is
 868    --  set to True (-t), then inconsistencies result in warnings rather than
 869    --  errors.
 870
 871    Tree_Output : Boolean := False;
 872    --  GNAT
 873    --  Set to True (-gnatt) to generate output tree file
 874
 875    Try_Semantics : Boolean := False;
 876    --  GNAT
 877    --  Flag set to force attempt at semantic analysis, even if parser errors
 878    --  occur. This will probably cause blowups at this stage in the game. On
 879    --  the other hand, most such blowups will be caught cleanly and simply
 880    --  say compilation abandoned. This flag is set to True by -gnatq or -gnatQ.
 881
 882    Undefined_Symbols_Are_False : Boolean := False;
 883    --  GNAT, GNATPREP
 884    --  Set to True by switch -u of gnatprep or -u in the preprocessing data
 885    --  file for the compiler. Indicates that while preprocessing sources,
 886    --  symbols that are not defined have the value FALSE.
 887
 888    Unique_Error_Tag : Boolean := Tag_Errors;
 889    --  GNAT
 890    --  Indicates if error messages are to be prefixed by the string error:
 891    --  Initialized from Tag_Errors, can be forced on with the -gnatU switch.
 892
 893    Universal_Addressing_On_AAMP : Boolean := False;
 894    --  GNAAMP
 895    --  Indicates if library-level objects should be accessed and updated
 896    --  using universal addressing instructions on the AAMP architecture.
 897    --  This flag is set to True when pragma Universal_Data is given as
 898    --  a configuration pragma.
 899
 900    Unreserve_All_Interrupts : Boolean := False;
 901    --  GNAT, GNATBIND
 902    --  Normally set False, set True if a valid Unreserve_All_Interrupts
 903    --  pragma appears anywhere in the main unit for GNAT, or if any ALI
 904    --  file has the corresponding attribute set in GNATBIND.
 905
 906    Upper_Half_Encoding : Boolean := False;
 907    --  GNAT
 908    --  Normally set False, indicating that upper half ASCII characters are
 909    --  used in the normal way to represent themselves. If the wide character
 910    --  encoding method uses the upper bit for this encoding, then this flag
 911    --  is set True, and upper half characters in the source indicate the
 912    --  start of a wide character sequence.
 913
 914    Usage_Requested : Boolean := False;
 915    --  GNAT, GNATBIND, GNATMAKE
 916    --  Set to True if -h (-gnath for the compiler) switch encountered
 917    --  requesting usage information
 918
 919    Use_VADS_Size : Boolean := False;
 920    --  GNAT
 921    --  Set to True if a valid pragma Use_VADS_Size is processed
 922
 923    Validity_Checks_On  : Boolean := True;
 924    --  GNAT
 925    --  This flag determines if validity checking is on or off. The initial
 926    --  state is on, and the required default validity checks are active. The
 927    --  actual set of checks that is performed if Validity_Checks_On is set
 928    --  is defined by the switches in package Sem_Val. The Validity_Checks_On
 929    --  flag is controlled by pragma Validity_Checks (On | Off), and also
 930    --  some generated compiler code (typically code that has to do with
 931    --  validity check generation) is compiled with this flag set to False.
 932    --  This flag is set to False by the -gnatp switch.
 933
 934    Verbose_Mode : Boolean := False;
 935    --  GNAT, GNATBIND, GNATMAKE, GNATLINK, GNATLS, GNATCHOP, GNATNAME,
 936    --  GNATCLEAN
 937    --  Set to True to get verbose mode (full error message text and location
 938    --  information sent to standard output, also header, copyright and summary)
 939
 940    Warn_On_Constant : Boolean := False;
 941    --  GNAT
 942    --  Set to True to generate warnings for variables that could be declared
 943    --  as constants. Modified by use of -gnatwk/K.
 944
 945    Warn_On_Dereference : Boolean := False;
 946    --  GNAT
 947    --  Set to True to generate warnings for implicit dereferences for array
 948    --  indexing and record component access. Modified by use of -gnatwd/D.
 949
 950    Warn_On_Export_Import : Boolean := True;
 951    --  GNAT
 952    --  Set to True to generate warnings for suspicious use of export or
 953    --  import pragmas. Modified by use of -gnatwx/X.
 954
 955    Warn_On_Hiding : Boolean := False;
 956    --  GNAT
 957    --  Set to True to generate warnings if a declared entity hides another
 958    --  entity. The default is that this warning is suppressed.
 959
 960    Warn_On_Modified_Unread : Boolean := False;
 961    --  GNAT
 962    --  Set to True to generate warnings if a variable is assigned but is
 963    --  never read. The default is that this warning is suppressed.
 964
 965    Warn_On_No_Value_Assigned : Boolean := True;
 966    --  GNAT
 967    --  Set to True to generate warnings if no value is ever assigned to a
 968    --  variable that is at least partially uninitialized. Set to false to
 969    --  suppress such warnings. The default is that such warnings are enabled.
 970
 971    Warn_On_Obsolescent_Feature : Boolean := False;
 972    --  GNAT
 973    --  Set to True to generate warnings on use of any feature in Annex J
 974    --  or if a subprogram is called for which a pragma Obsolescent applies.
 975
 976    Warn_On_Redundant_Constructs : Boolean := False;
 977    --  GNAT
 978    --  Set to True to generate warnings for redundant constructs (e.g. useless
 979    --  assignments/conversions). The default is that this warning is disabled.
 980
 981    Warn_On_Unchecked_Conversion : Boolean := True;
 982    --  GNAT
 983    --  Set to True to generate warnings for unchecked conversions that may have
 984    --  non-portable semantics (e.g. because sizes of types differ). The default
 985    --  is that this warning is enabled.
 986
 987    Warn_On_Unrecognized_Pragma : Boolean := True;
 988    --  GNAT
 989    --  Set to True to generate warnings for unrecognized pragmas. The default
 990    --  is that this warning is enabled.
 991
 992    type Warning_Mode_Type is (Suppress, Normal, Treat_As_Error);
 993    Warning_Mode : Warning_Mode_Type := Normal;
 994    --  GNAT, GNATBIND
 995    --  Controls treatment of warning messages. If set to Suppress, warning
 996    --  messages are not generated at all. In Normal mode, they are generated
 997    --  but do not count as errors. In Treat_As_Error mode, warning messages
 998    --  are generated and are treated as errors.
 999
1000    Wide_Character_Encoding_Method : WC_Encoding_Method := WCEM_Brackets;
1001    --  GNAT
1002    --  Method used for encoding wide characters in the source program. See
1003    --  description of type in unit System.WCh_Con for a list of the methods
1004    --  that are currently supported. Note that brackets notation is always
1005    --  recognized in source programs regardless of the setting of this
1006    --  variable. The default setting causes only the brackets notation
1007    --  to be recognized. If this is the main unit, this setting also
1008    --  controls the output of the W=? parameter in the ALI file, which
1009    --  is used to provide the default for Wide_Text_IO files.
1010
1011    Xref_Active : Boolean := True;
1012    --  GNAT
1013    --  Set if cross-referencing is enabled (i.e. xref info in ALI files)
1014
1015    Zero_Cost_Exceptions_Val : Boolean;
1016    Zero_Cost_Exceptions_Set : Boolean := False;
1017    --  GNAT
1018    --  These values are to record the setting of the zero cost exception
1019    --  handling mode set by argument switches (-gnatZ/-gnatL). If the
1020    --  value is set by one of these switches, then Zero_Cost_Exceptions_Set
1021    --  is set to True, and Zero_Cost_Exceptions_Val indicates the setting.
1022
1023    ----------------------------
1024    -- Configuration Settings --
1025    ----------------------------
1026
1027    --  These are settings that are used to establish the mode at the start
1028    --  of each unit. The values defined below can be affected either by
1029    --  command line switches, or by the use of appropriate configuration
1030    --  pragmas in the gnat.adc file.
1031
1032    Ada_83_Config : Boolean;
1033    --  GNAT
1034    --  This is the value of the configuration switch for Ada 83 mode, as set
1035    --  by the command line switch -gnat83, and possibly modified by the use
1036    --  of configuration pragmas Ada_95 and Ada_83 in the gnat.adc file. This
1037    --  switch is used to set the initial value for Ada_83 mode at the start
1038    --  of analysis of a unit. Note however, that the setting of this flag
1039    --  is ignored for internal and predefined units (which are always compiled
1040    --  in Ada 95 mode).
1041
1042    Dynamic_Elaboration_Checks_Config : Boolean := False;
1043    --  GNAT
1044    --  Set True for dynamic elaboration checking mode, as set by the -gnatE
1045    --  switch or by the use of pragma Elaboration_Checking (Dynamic).
1046
1047    Exception_Locations_Suppressed_Config : Boolean := False;
1048    --  GNAT
1049    --  Set True by use of the configuration pragma Suppress_Exception_Messages
1050
1051    Extensions_Allowed_Config : Boolean;
1052    --  GNAT
1053    --  This is the flag that indicates whether extensions are allowed.
1054    --  It can be set True either by use of the -gnatX switch, or by use
1055    --  of the configuration pragma Extensions_Allowed (On). It is always
1056    --  set to True for internal GNAT units, since extensions are always
1057    --  permitted in such units.
1058
1059    External_Name_Exp_Casing_Config : External_Casing_Type;
1060    --  GNAT
1061    --  This is the value of the configuration switch that controls casing
1062    --  of external symbols for which an explicit external name is given. It
1063    --  can be set to Uppercase by the command line switch -gnatF, and further
1064    --  modified by the use of the configuration pragma External_Name_Casing
1065    --  in the gnat.adc file. This flag is used to set the initial value
1066    --  for External_Name_Exp_Casing at the start of analyzing each unit.
1067    --  Note however that the setting of this flag is ignored for internal
1068    --  and predefined units (which are always compiled with As_Is mode).
1069
1070    External_Name_Imp_Casing_Config : External_Casing_Type;
1071    --  GNAT
1072    --  This is the value of the configuration switch that controls casing
1073    --  of external symbols where the external name is implicitly given. It
1074    --  can be set to Uppercase by the command line switch -gnatF, and further
1075    --  modified by the use of the configuration pragma External_Name_Casing
1076    --  in the gnat.adc file. This flag is used to set the initial value
1077    --  for External_Name_Imp_Casing at the start of analyzing each unit.
1078    --  Note however that the setting of this flag is ignored for internal
1079    --  and predefined units (which are always compiled with Lowercase mode).
1080
1081    Polling_Required_Config : Boolean;
1082    --  GNAT
1083    --  This is the value of the configuration switch that controls polling
1084    --  mode. It can be set True by the command line switch -gnatP, and then
1085    --  further modified by the use of pragma Polling in the gnat.adc file.
1086    --  This flag is used to set the initial value for Polling_Required
1087    --  at the start of analyzing each unit.
1088
1089    Use_VADS_Size_Config : Boolean;
1090    --  GNAT
1091    --  This is the value of the configuration switch that controls the use
1092    --  of VADS_Size instead of Size whereever the attribute Size is used.
1093    --  It can be set True by the use of the pragma Use_VADS_Size in the
1094    --  gnat.adc file. This flag is used to set the initial value for
1095    --  Use_VADS_Size at the start of analyzing each unit. Note however that
1096    --  the setting of this flag is ignored for internal and predefined
1097    --  units (which are always compiled with the standard Size semantics).
1098
1099    type Config_Switches_Type is private;
1100    --  Type used to save values of the switches set from Config values
1101
1102    procedure Save_Opt_Config_Switches (Save : out Config_Switches_Type);
1103    --  This procedure saves the current values of the switches which are
1104    --  initialized from the above Config values, and then resets these
1105    --  switches according to the Config value settings.
1106
1107    procedure Set_Opt_Config_Switches (Internal_Unit : Boolean);
1108    --  This procedure sets the switches to the appropriate initial values.
1109    --  The parameter Internal_Unit is True for an internal or predefined
1110    --  unit, and affects the way the switches are set (see above).
1111
1112    procedure Restore_Opt_Config_Switches (Save : Config_Switches_Type);
1113    --  This procedure restores a set of switch values previously saved
1114    --  by a call to Save_Opt_Switches.
1115
1116    procedure Register_Opt_Config_Switches;
1117    --  This procedure is called after processing the gnat.adc file to record
1118    --  the values of the Config switches, as possibly modified by the use
1119    --  of command line switches and configuration pragmas.
1120
1121    ------------------------
1122    -- Other Global Flags --
1123    ------------------------
1124
1125    Expander_Active : Boolean := False;
1126    --  A flag that indicates if expansion is active (True) or deactivated
1127    --  (False). When expansion is deactivated all calls to expander routines
1128    --  have no effect. Note that the initial setting of False is merely to
1129    --  prevent saving of an undefined value for an initial call to the
1130    --  Expander_Mode_Save_And_Set procedure. For more information on the
1131    --  use of this flag, see package Expander. Indeed this flag might more
1132    --  logically be in the spec of Expander, but it is referenced by Errout,
1133    --  and it really seems wrong for Errout to depend on Expander.
1134
1135    -----------------------
1136    -- Tree I/O Routines --
1137    -----------------------
1138
1139    procedure Tree_Read;
1140    --  Reads switch settings from current tree file using Tree_Read
1141
1142    procedure Tree_Write;
1143    --  Writes out switch settings to current tree file using Tree_Write
1144
1145    --------------------------
1146    -- ASIS Version Control --
1147    --------------------------
1148
1149    --  These two variables (Tree_Version_String and Tree_ASIS_Version_Number)
1150    --  are supposed to be used in the GNAT/ASIS version check performed in
1151    --  the ASIS code (this package is also a part of the ASIS implementation).
1152    --  They are set by Tree_Read procedure, so they represent the version
1153    --  number (and the version string) of the compiler which has created the
1154    --  tree, and they are supposed to be compared with the corresponding values
1155    --  from the Gnatvsn package which is a part of ASIS implementation.
1156
1157    Tree_Version_String : String (Gnat_Version_String'Range);
1158    --  Used to store the compiler version string read from a tree file to
1159    --  check if it is the same as stored in the version string in Gnatvsn.
1160    --  Therefore its length is taken directly from the version string in
1161    --  Gnatvsn. If the length of the version string stored in the tree is
1162    --  different, then versions are for sure different, and a string containing
1163    --  '?' characters is assigned to this variable as a result of tree read.
1164
1165    Tree_ASIS_Version_Number : Int;
1166    --  Used to store the ASIS version number read from a tree file to check if
1167    --  it is the same as stored in the ASIS version number in Gnatvsn.
1168
1169 private
1170
1171    type Config_Switches_Type is record
1172       Ada_83                         : Boolean;
1173       Dynamic_Elaboration_Checks     : Boolean;
1174       Exception_Locations_Suppressed : Boolean;
1175       Extensions_Allowed             : Boolean;
1176       External_Name_Exp_Casing       : External_Casing_Type;
1177       External_Name_Imp_Casing       : External_Casing_Type;
1178       Polling_Required               : Boolean;
1179       Use_VADS_Size                  : Boolean;
1180    end record;
1181
1182 end Opt;