1------------------------------------------------------------------------------
2--                                                                          --
3--                         GNAT COMPILER COMPONENTS                         --
4--                                                                          --
5--                                  O P T                                   --
6--                                                                          --
7--                                 S p e c                                  --
8--                                                                          --
9--          Copyright (C) 1992-2015, 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 3,  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.                                     --
17--                                                                          --
18-- As a special exception under Section 7 of GPL version 3, you are granted --
19-- additional permissions described in the GCC Runtime Library Exception,   --
20-- version 3.1, as published by the Free Software Foundation.               --
21--                                                                          --
22-- You should have received a copy of the GNU General Public License and    --
23-- a copy of the GCC Runtime Library Exception along with this program;     --
24-- see the files COPYING3 and COPYING.RUNTIME respectively.  If not, see    --
25-- <http://www.gnu.org/licenses/>.                                          --
26--                                                                          --
27-- GNAT was originally developed  by the GNAT team at  New York University. --
28-- Extensive contributions were provided by Ada Core Technologies Inc.      --
29--                                                                          --
30------------------------------------------------------------------------------
31
32--  This package contains global flags set by the initialization routine from
33--  the command line and referenced throughout the compiler, the binder, or
34--  other GNAT tools. The comments indicate which options are used by which
35--  programs (GNAT, GNATBIND, GNATLINK, GNATMAKE, etc).
36
37--  Some flags are labelled "PROJECT MANAGER". These are used by tools that
38--  use the Project Manager. These tools include gnatmake, gnatname, the gnat
39--  driver, gnatclean, gprbuild and gprclean.
40
41with Hostparm; use Hostparm;
42with Types;    use Types;
43
44pragma Warnings (Off);
45--  This package is used also by gnatcoll
46with System.Strings; use System.Strings;
47with System.WCh_Con; use System.WCh_Con;
48pragma Warnings (On);
49
50package Opt is
51
52   ----------------------
53   -- Checksum Control --
54   ----------------------
55
56   --  Checksums are computed for sources to check for sources being the same
57   --  from a compilation point of view (e.g. spelling of identifiers and
58   --  white space layout do not count in this computation).
59
60   --  The way the checksum is computed has evolved across the various versions
61   --  of GNAT. When gprbuild is called with -m, the checksums must be computed
62   --  the same way in gprbuild as it was in the GNAT version of the compiler.
63   --  The different ways are
64
65   --    Version 6.4 and later:
66
67   --      The Accumulate_Token_Checksum procedure is called after each numeric
68   --      literal and each identifier/keyword. For keywords, Tok_Identifier is
69   --      used in the call to Accumulate_Token_Checksum.
70
71   --    Versions 5.04 to 6.3:
72
73   --      For keywords, the token value were used in the call to procedure
74   --      Accumulate_Token_Checksum. Type Token_Type did not include Tok_Some.
75
76   --    Versions 5.03:
77
78   --      For keywords, the token value were used in the call to
79   --      Accumulate_Token_Checksum. Type Token_Type did not include
80   --      Tok_Interface, Tok_Overriding, Tok_Synchronized and Tok_Some.
81
82   --    Versions 5.02 and before:
83
84   --      No calls to procedure Accumulate_Token_Checksum (the checksum
85   --      mechanism was introduced in version 5.03).
86
87   --  To signal to the scanner whether Accumulate_Token_Checksum needs to be
88   --  called and what versions to call, the following Boolean flags are used:
89
90   Checksum_Accumulate_Token_Checksum : Boolean := True;
91   --  GPRBUILD
92   --  Set to False by gprbuild when the version of GNAT is 5.02 or before. If
93   --  this switch is False, then we do not call Accumulate_Token_Checksum, so
94   --  the setting of the following two flags is irrelevant.
95
96   Checksum_GNAT_6_3 : Boolean := False;
97   --  GPRBUILD
98   --  Set to True by gprbuild when the version of GNAT is 6.3 or before.
99
100   Checksum_GNAT_5_03 : Boolean := False;
101   --  GPRBUILD
102   --  Set to True by gprbuild when the version of GNAT is 5.03 or before.
103
104   ----------------------------------------------
105   -- Settings of Modes for Current Processing --
106   ----------------------------------------------
107
108   --  The following mode values represent the current state of processing.
109   --  The values set here are the default values. Unless otherwise noted,
110   --  the value may be reset in Switch-? with an appropriate switch. In
111   --  some cases, the values can also be modified by pragmas, and in the
112   --  case of some binder variables, Gnatbind.Scan_Bind_Arg may modify
113   --  the default values.
114
115   type Ada_Version_Type is (Ada_83, Ada_95, Ada_2005, Ada_2012);
116   pragma Ordered (Ada_Version_Type);
117   --  Versions of Ada for Ada_Version below. Note that these are ordered,
118   --  so that tests like Ada_Version >= Ada_95 are legitimate and useful.
119   --  Think twice before using "="; Ada_Version >= Ada_2012 is more likely
120   --  what you want, because it will apply to future versions of the language.
121
122   Ada_Version_Default : constant Ada_Version_Type := Ada_2012;
123   pragma Warnings (Off, Ada_Version_Default);
124   --  GNAT
125   --  Default Ada version if no switch given. The Warnings off is to kill
126   --  constant condition warnings.
127
128   Ada_Version : Ada_Version_Type := Ada_Version_Default;
129   --  GNAT
130   --  Current Ada version for compiler, as set by configuration pragmas,
131   --  compiler switches, or implicitly (to Ada_Version_Runtime) when a
132   --  predefined or internal file is compiled.
133
134   Ada_Version_Pragma : Node_Id := Empty;
135   --  Reflects the Ada_xxx pragma that resulted in setting Ada_Version. Used
136   --  to specialize error messages complaining about the Ada version in use.
137
138   Ada_Version_Explicit : Ada_Version_Type := Ada_Version_Default;
139   --  GNAT
140   --  Like Ada_Version, but does not get set implicitly for predefined or
141   --  internal units, so it reflects the Ada version explicitly set using
142   --  configuration pragmas or compiler switches (or if neither appears, it
143   --  remains set to Ada_Version_Default). This is used in the rare cases
144   --  (notably pragma Obsolescent) where we want the explicit version set.
145
146   Ada_Version_Runtime : Ada_Version_Type := Ada_2012;
147   --  GNAT
148   --  Ada version used to compile the runtime. Used to set Ada_Version (but
149   --  not Ada_Version_Explicit) when compiling predefined or internal units.
150
151   Ada_Final_Suffix : constant String := "final";
152   Ada_Final_Name   : String_Ptr := new String'("ada" & Ada_Final_Suffix);
153   --  GNATBIND
154   --  The name of the procedure that performs the finalization at the end of
155   --  execution. This variable may be modified by Gnatbind.Scan_Bind_Arg.
156
157   Ada_Init_Suffix : constant String := "init";
158   Ada_Init_Name   : String_Ptr := new String'("ada" & Ada_Init_Suffix);
159   --  GNATBIND
160   --  The name of the procedure that performs initialization at the start
161   --  of execution. This variable may be modified by Gnatbind.Scan_Bind_Arg.
162
163   Ada_Main_Name_Suffix : constant String := "main";
164   --  GNATBIND
165   --  The suffix for Ada_Main_Name. Defined as a constant here so that it
166   --  can be referenced in a uniform manner to create either the default
167   --  value of Ada_Main_Name (declared below), or the non-default name
168   --  set by Gnatbind.Scan_Bind_Arg.
169
170   Ada_Main_Name : String_Ptr := new String'("ada_" & Ada_Main_Name_Suffix);
171   --  GNATBIND
172   --  The name of the Ada package generated by the binder (when in Ada mode).
173   --  This variable may be modified by Gnatbind.Scan_Bind_Arg.
174
175   Address_Clause_Overlay_Warnings : Boolean := True;
176   --  GNAT
177   --  Set False to disable address clause warnings. Modified by use of
178   --  -gnatwo/O.
179
180   Address_Is_Private : Boolean := False;
181   --  GNAT, GNATBIND
182   --  Set True if package System has the line "type Address is private;"
183
184   All_Errors_Mode : Boolean := False;
185   --  GNAT
186   --  Flag set to force display of multiple errors on a single line and
187   --  also repeated error messages for references to undefined identifiers
188   --  and certain other repeated error messages. Set by use of -gnatf.
189
190   Allow_Integer_Address : Boolean := False;
191   --  GNAT
192   --  Allow use of integer expression in a context requiring System.Address.
193   --  Set by the use of configuration pragma Allow_Integer_Address Also set
194   --  in relaxed semantics mode for use by CodePeer or when -gnatd.M is used.
195
196   All_Sources : Boolean := False;
197   --  GNATBIND
198   --  Set to True to require all source files to be present. This flag is
199   --  directly modified by gnatmake to affect the shared binder routines.
200
201   Alternate_Main_Name : String_Ptr := null;
202   --  GNATBIND
203   --  Set to non-null when Bind_Alternate_Main_Name is True. This value
204   --  is modified as needed by Gnatbind.Scan_Bind_Arg.
205
206   ASIS_Mode : Boolean := False;
207   --  GNAT
208   --  Enable semantic checks and tree transformations that are important
209   --  for ASIS but that are usually skipped if Operating_Mode is set to
210   --  Check_Semantics. This flag does not have the corresponding option to set
211   --  it ON. It is set ON when Tree_Output is set ON, it can also be set ON
212   --  from the code of GNSA-based tool (a client may need to set ON the
213   --  Back_Annotate_Rep_Info flag in this case. At the moment this does not
214   --  make very much sense, because GNSA cannot do back annotation).
215
216   Assertions_Enabled : Boolean := False;
217   --  GNAT
218   --  Indicates default policy (True = Check, False = Ignore) to be applied
219   --  to all assertion aspects and pragmas, and to pragma Debug, if there is
220   --  no overriding Assertion_Policy, Check_Policy, or Debug_Policy pragma.
221   --  Set True by use of -gnata.
222
223   Assume_No_Invalid_Values : Boolean := False;
224   --  GNAT Normally, in accordance with (RM 13.9.1 (9-11)) the front end
225   --  assumes that values could have invalid representations, unless it can
226   --  clearly prove that the values are valid. If this switch is set (by
227   --  pragma Assume_No_Invalid_Values (On)), then the compiler assumes values
228   --  are valid and in range of their representations. This feature is now
229   --  fully enabled in the compiler.
230
231   Back_Annotate_Rep_Info : Boolean := False;
232   --  GNAT
233   --  If set True, enables back annotation of representation information
234   --  by gigi, even in -gnatc mode. This is set True by the use of -gnatR
235   --  (list representation information) or -gnatt (generate tree). It is
236   --  also set true if certain Unchecked_Conversion instantiations require
237   --  checking based on annotated values.
238
239   Back_End_Handles_Limited_Types : Boolean;
240   --  This flag is set true if the back end can properly handle limited or
241   --  other by reference types, and avoid copies. If this flag is False, then
242   --  the front end does special expansion for if/case expressions to make
243   --  sure that no copy occurs. If the flag is True, then the expansion for
244   --  if and case expressions relies on the back end properly handling things.
245   --  Currently the default is False for all cases (set in gnat1drv). The
246   --  default can be modified using -gnatd.L (sets the flag True). This is
247   --  used to test the possibility of having the backend handle this.
248
249   Back_End_Inlining : Boolean := False;
250   --  GNAT
251   --  Set True to activate inlining by back-end expansion. This is the normal
252   --  default mode for gcc targets, so it is True on such targets unless the
253   --  switches -gnatN or -gnatd.z are used. See circuitry in gnat1drv for the
254   --  exact conditions for setting this switch.
255
256   Bind_Alternate_Main_Name : Boolean := False;
257   --  GNATBIND
258   --  True if main should be called Alternate_Main_Name.all.
259   --  This variable may be set to True by Gnatbind.Scan_Bind_Arg.
260
261   Bind_Main_Program : Boolean := True;
262   --  GNATBIND
263   --  Set to False if not binding main Ada program
264
265   Bind_For_Library : Boolean := False;
266   --  GNATBIND
267   --  Set to True if the binder needs to generate a file designed for building
268   --  a library. May be set to True by Gnatbind.Scan_Bind_Arg.
269
270   Bind_Only : Boolean := False;
271   --  GNATMAKE, GPRBUILD
272   --  Set to True to skip compile and link steps
273   --  (except when Compile_Only and/or Link_Only are True).
274
275   Blank_Deleted_Lines : Boolean := False;
276   --  GNAT, GNATPREP
277   --  Output empty lines for each line of preprocessed input that is deleted
278   --  in the output, including preprocessor lines starting with a '#'.
279
280   Brief_Output : Boolean := False;
281   --  GNAT, GNATBIND
282   --  Force brief error messages to standard error, even if verbose mode is
283   --  set (so that main error messages go to standard output).
284
285   Build_Bind_And_Link_Full_Project : Boolean := False;
286   --  GNATMAKE
287   --  Set to True to build, bind and link all the sources of a project file
288   --  (switch -B)
289
290   Check_Aliasing_Of_Parameters : Boolean := False;
291   --  GNAT
292   --  Set to True to detect whether subprogram parameters and function results
293   --  alias the same object(s).
294
295   Check_Float_Overflow : Boolean := False;
296   --  GNAT
297   --  Set to True to check that operations on predefined unconstrained float
298   --  types (e.g. Float, Long_Float) do not overflow and generate infinities
299   --  or invalid values. Set by the Check_Float_Overflow pragma, or by use
300   --  of the -gnateF switch.
301
302   Check_Object_Consistency : Boolean := False;
303   --  GNATBIND, GNATMAKE
304   --  Set to True to check whether every object file is consistent with its
305   --  corresponding ada library information (ALI) file. An object file is
306   --  inconsistent with the corresponding ALI file if the object file does
307   --  not exist or if it has an older time stamp than the ALI file. Default
308   --  above is for GNATBIND. GNATMAKE overrides this default to True (see
309   --  Make.Initialize) since we normally do need to check source consistencies
310   --  in gnatmake.
311
312   Check_Only : Boolean := False;
313   --  GNATBIND
314   --  Set to True to do checks only, no output of binder file
315
316   Check_Policy_List : Node_Id := Empty;
317   --  GNAT
318   --  This points to the list of N_Pragma nodes for Check_Policy pragmas
319   --  that are linked through the Next_Pragma fields, with the list being
320   --  terminated by Empty. The order is most recently processed first. Note
321   --  that Push_Scope and Pop_Scope in Sem_Ch8 save and restore the value
322   --  of this variable, implementing the required scope control for pragmas
323   --  appearing in a declarative part.
324
325   Check_Readonly_Files : Boolean := False;
326   --  GNATMAKE
327   --  Set to True to check readonly files during the make process
328
329   Check_Source_Files : Boolean := True;
330   --  GNATBIND, GNATMAKE
331   --  Set to True to enable consistency checking for any source files that
332   --  are present (i.e. date must match the date in the library info file).
333   --  Set to False for object file consistency check only. This flag is
334   --  directly modified by gnatmake, to affect the shared binder routines.
335
336   Check_Switches : Boolean := False;
337   --  GNATMAKE, GPBUILD
338   --  Set to True to check compiler options during the make process
339
340   Check_Unreferenced : Boolean := False;
341   --  GNAT
342   --  Set to True to enable checking for unreferenced entities other
343   --  than formal parameters (for which see Check_Unreferenced_Formals)
344   --  Modified by use of -gnatwu/U.
345
346   Check_Unreferenced_Formals : Boolean := False;
347   --  GNAT
348   --  Set to True to check for unreferenced formals. This is turned on by
349   --  -gnatwa/wf/wu and turned off by -gnatwA/wF/wU.
350
351   Check_Validity_Of_Parameters : Boolean := False;
352   --  GNAT
353   --  Set to True to check for proper scalar initialization of subprogram
354   --  parameters on both entry and exit. Turned on by??? turned off by???
355
356   Check_Withs : Boolean := False;
357   --  GNAT
358   --  Set to True to enable checking for unused withs, and also the case
359   --  of withing a package and using none of the entities in the package.
360   --  Modified by use of -gnatwu/U.
361
362   CodePeer_Mode : Boolean := False;
363   --  GNAT, GNATBIND, GPRBUILD
364   --  Enable full CodePeer mode (SCIL generation, disable switches that
365   --  interact badly with it, etc...). This is turned on by -gnatC.
366
367   Commands_To_Stdout : Boolean := False;
368   --  GNATMAKE
369   --  True if echoed commands to be written to stdout instead of stderr
370
371   Comment_Deleted_Lines : Boolean := False;
372   --  GNATPREP
373   --  True if source lines removed by the preprocessor should be commented
374   --  in the output file.
375
376   Compilation_Time : String (1 .. 19);
377   --  GNAT
378   --  Compilation date and time in form YYYY-MM-DD HH:MM:SS
379
380   Compile_Only : Boolean := False;
381   --  GNATMAKE, GNATCLEAN, GPBUILD, GPRCLEAN
382   --  GNATMAKE, GPRBUILD:
383   --    set True to skip bind and link steps (except when Bind_Only is True)
384   --  GNATCLEAN, GPRCLEAN:
385   --    set True to delete only the files produced by the compiler but not the
386   --    library files or the executable files.
387
388   Compiler_Unit : Boolean := False;
389   --  GNAT1
390   --  Set True by an occurrence of pragma Compiler_Unit_Warning (or of the
391   --  obsolete pragma Compiler_Unit) in the main unit. Once set True, stays
392   --  True, since any units that are with'ed directly or indirectly by
393   --  a Compiler_Unit_Warning main unit are subject to the same restrictions.
394   --  Such units really should have their own pragmas, but we do not bother to
395   --  check for that, so this transitivity provides extra checking.
396
397   Config_File : Boolean := True;
398   --  GNAT
399   --  Set to False to inhibit reading and processing of gnat.adc file
400
401   Config_File_Names : String_List_Access := null;
402   --  GNAT
403   --  Names of configuration pragmas files (given by switches -gnatec)
404
405   Configurable_Run_Time_Mode : Boolean := False;
406   --  GNAT, GNATBIND
407   --  Set True if the compiler is operating in configurable run-time mode.
408   --  This happens if the flag Targparm.Configurable_Run_TimeMode_On_Target
409   --  is set True, or if pragma No_Run_Time is used. See the spec of Rtsfind
410   --  for details on the handling of the latter pragma.
411
412   Constant_Condition_Warnings : Boolean := False;
413   --  GNAT
414   --  Set to True to activate warnings on constant conditions. Modified by
415   --  use of -gnatwc/C.
416
417   Create_Mapping_File : Boolean := False;
418   --  GNATMAKE
419   --  Set to True (-C switch) to indicate that the compiler will be invoked
420   --  with a mapping file (-gnatem compiler switch).
421
422   subtype Debug_Level_Value is Nat range 0 .. 3;
423   Debugger_Level : Debug_Level_Value := 0;
424   --  GNAT, GNATBIND
425   --  The value given to the -g parameter. The default value for -g with
426   --  no value is 2. If no -g is specified, defaults to 0.
427   --  Note that the generated code should never depend on this variable,
428   --  since we want debug info to be nonintrusive on the generate code.
429
430   Default_Exit_Status : Int := 0;
431   --  GNATBIND
432   --  Set the default exit status value. Set by the -Xnnn switch for the
433   --  binder.
434
435   Debug_Generated_Code : Boolean := False;
436   --  GNAT
437   --  Set True (-gnatD switch) to debug generated expanded code instead
438   --  of the original source code. Causes debugging information to be
439   --  written with respect to the generated code file that is written.
440
441   Default_Pool : Node_Id := Empty;
442   --  GNAT
443   --  Used to record the storage pool name (or null literal) that is the
444   --  argument of an applicable pragma Default_Storage_Pool.
445   --    Empty:       No pragma Default_Storage_Pool applies.
446   --    N_Null node: "pragma Default_Storage_Pool (null);" applies.
447   --    otherwise:   "pragma Default_Storage_Pool (X);" applies, and
448   --                 this points to the name X.
449   --  Push_Scope and Pop_Scope in Sem_Ch8 save and restore this value.
450   Default_Stack_Size : Int := -1;
451   --  GNATBIND
452   --  Set to default primary stack size in units of bytes. Set by
453   --  the -dnnn switch for the binder. A value of -1 indicates that no
454   --  default was set by the binder.
455
456   Default_Sec_Stack_Size : Int := -1;
457   --  GNATBIND
458   --  Set to default secondary stack size in units of bytes. Set by
459   --  the -Dnnn switch for the binder. A value of -1 indicates that no
460   --  default was set by the binder, and that the default should be the
461   --  initial value of System.Secondary_Stack.Default_Secondary_Stack_Size.
462
463   Default_SSO : Character := ' ';
464   --  GNAT
465   --  Set if a pragma Default_Scalar_Storage_Order has been given. The value
466   --  of ' ' indicates that no default has been set, otherwise the value is
467   --  either 'H' for High_Order_First or 'L' for Lower_Order_First.
468
469   Detect_Blocking : Boolean := False;
470   --  GNAT
471   --  Set True to force the run time to raise Program_Error if calls to
472   --  potentially blocking operations are detected from protected actions.
473
474   Directories_Must_Exist_In_Projects : Boolean := True;
475   --  PROJECT MANAGER
476   --  Set to False with switch -f of gnatclean and gprclean
477
478   Display_Compilation_Progress : Boolean := False;
479   --  GNATMAKE, GPRBUILD
480   --  Set True (-d switch) to display information on progress while compiling
481   --  files. Internal flag to be used in conjunction with an IDE (e.g GPS).
482
483   type Distribution_Stub_Mode_Type is
484   --  GNAT
485     (No_Stubs,
486      --  Normal mode, no generation/compilation of distribution stubs
487
488      Generate_Receiver_Stub_Body,
489      --  The unit being compiled is the RCI body, and the compiler will
490      --  generate the body for the receiver stubs and compile it.
491
492      Generate_Caller_Stub_Body);
493      --  The unit being compiled is the RCI spec, and the compiler will
494      --  generate the body for the caller stubs and compile it.
495
496   Distribution_Stub_Mode : Distribution_Stub_Mode_Type := No_Stubs;
497   --  GNAT
498   --  This enumeration variable indicates the five states of distribution
499   --  annex stub generation/compilation.
500
501   Do_Not_Execute : Boolean := False;
502   --  GNATMAKE
503   --  Set to True if no actual compilations should be undertaken
504
505   Dump_Source_Text : Boolean := False;
506   --  GNAT
507   --  Set to True (by -gnatL) to dump source text intermingled with generated
508   --  code. Effective only if either of Debug/Print_Generated_Code is true.
509
510   Dynamic_Elaboration_Checks : Boolean := False;
511   --  GNAT
512   --  Set True for dynamic elaboration checking mode, as set by the -gnatE
513   --  switch or by the use of pragma Elaboration_Checks (Dynamic).
514
515   Dynamic_Stack_Measurement : Boolean := False;
516   --  GNATBIND
517   --  Set True to enable dynamic stack measurement (-u flag for gnatbind)
518
519   Dynamic_Stack_Measurement_Array_Size : Nat := 100;
520   --  GNATBIND
521   --  Number of measurements we want to store during dynamic stack analysis.
522   --  When the buffer is full, non-storable results will be output on the fly.
523   --  The value is relevant only if Dynamic_Stack_Measurement is set. Set
524   --  by processing of -u flag for gnatbind.
525
526   Elab_Dependency_Output : Boolean := False;
527   --  GNATBIND
528   --  Set to True to output complete list of elaboration constraints
529
530   Elab_Order_Output : Boolean := False;
531   --  GNATBIND
532   --  Set to True to output chosen elaboration order
533
534   Elab_Info_Messages : Boolean := False;
535   --  GNAT
536   --  Set to True to output info messages for static elabmodel (-gnatel)
537
538   Elab_Warnings : Boolean := False;
539   --  GNAT
540   --  Set to True to generate elaboration warnings (-gnatwl)
541
542   Error_Msg_Line_Length : Nat := 0;
543   --  GNAT
544   --  Records the error message line length limit. If this is set to zero,
545   --  then we get the old style behavior, in which each call to the error
546   --  message routines generates one line of output as a separate message.
547   --  If it is set to a non-zero value, then continuation lines are folded
548   --  to make a single long message, and then this message is split up into
549   --  multiple lines not exceeding the specified length. Set by -gnatj=nn.
550
551   Error_To_Warning : Boolean := False;
552   --  GNAT
553   --  If True, then certain error messages (e.g. parameter overlap messages
554   --  for procedure calls in Ada 2012 mode) are treated as warnings instead
555   --  of errors. Set by debug flag -gnatd.E. A search for Error_To_Warning
556   --  will identify affected messages.
557
558   Exception_Handler_Encountered : Boolean := False;
559   --  GNAT
560   --  This flag is set true if the parser encounters an exception handler.
561   --  It is used to set Warn_On_Exception_Propagation True if the restriction
562   --  No_Exception_Propagation is set.
563
564   Exception_Extra_Info : Boolean := False;
565   --  GNAT
566   --  True when switch -gnateE is used. When True, generate extra information
567   --  associated with exception messages (in particular range and index
568   --  checks).
569
570   Exception_Locations_Suppressed : Boolean := False;
571   --  GNAT
572   --  Set to True if a Suppress_Exception_Locations configuration pragma is
573   --  currently active.
574
575   type Exception_Mechanism_Type is
576   --  Determines the kind of mechanism used to handle exceptions
577   --
578     (Front_End_SJLJ,
579      --  Exceptions use setjmp/longjmp generated explicitly by the front end
580      --  (this includes gigi or other equivalent parts of the code generator).
581      --  AT END handlers are converted into exception handlers by the front
582      --  end in this mode.
583
584      Back_End_ZCX,
585      --  Exceptions are handled by the back end. The front end simply
586      --  generates the handlers as they appear in the source, and AT END
587      --  handlers are left untouched (they are not converted into exception
588      --  handlers when operating in this mode). Propagation is performed
589      --  using a frame unwinding scheme and requires no particular setup code
590      --  at handler sites on regular execution paths.
591
592      Back_End_SJLJ);
593      --  Similar to Back_End_ZCX with respect to the front-end processing
594      --  of regular and AT-END handlers. A setjmp/longjmp scheme is used to
595      --  propagate and setup handler contexts on regular execution paths.
596
597   pragma Convention (C, Exception_Mechanism_Type);
598
599   Exception_Mechanism : Exception_Mechanism_Type := Front_End_SJLJ;
600   --  GNAT
601   --  Set to the appropriate value depending on the flags in system.ads
602   --  (Frontend_Exceptions + ZCX_By_Default). The C convention is there to
603   --  allow access by gigi.
604
605   function Back_End_Exceptions return Boolean;
606   function Front_End_Exceptions return Boolean;
607   function ZCX_Exceptions return Boolean;
608   function SJLJ_Exceptions return Boolean;
609   --  GNAT
610   --  Various properties of the active Exception_Mechanism
611
612   Exception_Tracebacks : Boolean := False;
613   --  GNATBIND
614   --  Set to True to store tracebacks in exception occurrences (-Ea or -E)
615
616   Exception_Tracebacks_Symbolic : Boolean := False;
617   --  GNATBIND
618   --  Set to True to store tracebacks in exception occurrences and enable
619   --  symbolic tracebacks (-Es).
620
621   Extensions_Allowed : Boolean := False;
622   --  GNAT
623   --  Set to True by switch -gnatX if GNAT specific language extensions
624   --  are allowed. Currently there are no such defined extensions.
625
626   type External_Casing_Type is (
627     As_Is,       -- External names cased as they appear in the Ada source
628     Uppercase,   -- External names forced to all uppercase letters
629     Lowercase);  -- External names forced to all lowercase letters
630
631   External_Name_Imp_Casing : External_Casing_Type := Lowercase;
632   --  GNAT
633   --  The setting of this flag determines the casing of external names
634   --  when the name is implicitly derived from an entity name (i.e. either
635   --  no explicit External_Name or Link_Name argument is used, or, in the
636   --  case of extended DEC pragmas, the external name is given using an
637   --  identifier. The As_Is setting is not permitted here (since this would
638   --  create Ada source programs that were case sensitive).
639
640   External_Name_Exp_Casing : External_Casing_Type := As_Is;
641   --  GNAT
642   --  The setting of this flag determines the casing of an external name
643   --  specified explicitly with a string literal. As_Is means the string
644   --  literal is used as given with no modification to the casing. If
645   --  Lowercase or Uppercase is set, then the string is forced to all
646   --  lowercase or all uppercase letters as appropriate. Note that this
647   --  setting has no effect if the external name is given using an identifier
648   --  in the case of extended DEC import/export pragmas (in this case the
649   --  casing is controlled by External_Name_Imp_Casing), and also has no
650   --  effect if an explicit Link_Name is supplied (a link name is always
651   --  used exactly as given).
652
653   External_Unit_Compilation_Allowed : Boolean := False;
654   --  GNATMAKE
655   --  When True (set by gnatmake switch -x), allow compilation of sources
656   --  that are not part of any project file.
657
658   Fast_Math : Boolean := False;
659   --  GNAT
660   --  Indicates the current setting of Fast_Math mode, as set by the use
661   --  of a Fast_Math pragma (set True by Fast_Math (On)).
662
663   Force_ALI_Tree_File : Boolean := False;
664   --  GNAT
665   --  Force generation of ALI file even if errors are encountered. Also forces
666   --  generation of tree file if -gnatt is also set. Set on by use of -gnatQ.
667
668   Disable_ALI_File : Boolean := False;
669   --  GNAT
670   --  Disable generation of ALI file
671
672   Follow_Links_For_Files : Boolean := False;
673   --  PROJECT MANAGER
674   --  Set to True (-eL) to process the project files in trusted mode. If
675   --  Follow_Links is False, it is assumed that the project doesn't contain
676   --  any file duplicated through symbolic links (although the latter are
677   --  still valid if they point to a file which is outside of the project),
678   --  and that no directory has a name which is a valid source name.
679
680   Follow_Links_For_Dirs : Boolean := False;
681   --  PROJECT MANAGER
682   --  Set to True if directories can be links in this project, and therefore
683   --  additional system calls must be performed to ensure that we always see
684   --  the same full name for each directory.
685
686   Force_Checking_Of_Elaboration_Flags : Boolean := False;
687   --  GNATBIND
688   --  True if binding with forced checking of the elaboration flags
689   --  (-F switch set).
690
691   Force_Compilations : Boolean := False;
692   --  GNATMAKE, GPRBUILD
693   --  Set to force recompilations even when the objects are up-to-date.
694
695   Front_End_Inlining : Boolean := False;
696   --  GNAT
697   --  Set True to activate inlining by front-end expansion (even on GCC
698   --  targets, where inlining is normally handled by the back end). Set by
699   --  the flag -gnatN (which is now considered obsolescent, since the GCC
700   --  back end can do a better job of inlining than the front end these days.
701
702   Full_Path_Name_For_Brief_Errors : Boolean := False;
703   --  PROJECT MANAGER
704   --  When True, in Brief_Output mode, each error message line will start with
705   --  the full path name of the source. When False, only the file name without
706   --  directory information is used.
707
708   Full_List : Boolean := False;
709   --  GNAT
710   --  Set True to generate full source listing with embedded errors
711
712   Full_List_File_Name : String_Ptr := null;
713   --  GNAT
714   --  Set to file name to generate full source listing to named file (or if
715   --  the name is of the form .xxx, then to name.xxx where name is the source
716   --  file name with extension stripped.
717
718   Generate_C_Code : Boolean := False;
719   --  GNAT
720   --  If True, the Cprint circuitry to generate C code output is activated.
721   --  Set True by use of -gnateg or -gnatd.V.
722
723   Generate_CodePeer_Messages : Boolean := False;
724   --  GNAT
725   --  Generate CodePeer messages. Ignored if CodePeer_Mode is false. This is
726   --  turned on by -gnateC.
727
728   Generate_Processed_File : Boolean := False;
729   --  GNAT
730   --  True when switch -gnateG is used. When True, create in a file
731   --  <source>.prep, if the source is preprocessed.
732
733   Generate_SCIL : Boolean := False;
734   --  GNAT
735   --  Set True to activate SCIL code generation.
736
737   Generate_SCO : Boolean := False;
738   --  GNAT
739   --  True when switch -fdump-scos (or -gnateS) is used. When True, Source
740   --  Coverage Obligation (SCO) information is generated and output in the ALI
741   --  file. See unit Par_SCO for full details.
742
743   Generate_SCO_Instance_Table : Boolean := False;
744   --  GNAT
745   --  True when switch -fdump-scos is used. When True, a table of instances is
746   --  included in SCOs.
747
748   Generating_Code : Boolean := False;
749   --  GNAT
750   --  True if the frontend finished its work and has called the backend to
751   --  process the tree and generate the object file.
752
753   type Ghost_Mode_Type is (None, Check, Ignore);
754   --  Possible legal modes that can be set by aspect/pragma Ghost as well as
755   --  value None, which indicates that no such aspect/pragma applies.
756
757   Ghost_Mode : Ghost_Mode_Type := None;
758   --  GNAT
759   --  Current Ghost mode setting
760
761   Global_Discard_Names : Boolean := False;
762   --  GNAT, GNATBIND
763   --  True if a pragma Discard_Names appeared as a configuration pragma for
764   --  the current compilation unit.
765
766   GNAT_Encodings : Int;
767   pragma Import (C, GNAT_Encodings, "gnat_encodings");
768   --  Constant controlling the balance between GNAT encodings and standard
769   --  DWARF to emit in the debug information. See aamissing.c for definitions
770   --  for the GNAAMP back end. It accepts the following values.
771
772   DWARF_GNAT_Encodings_All     : constant Int := 0;
773   DWARF_GNAT_Encodings_GDB     : constant Int := 1;
774   DWARF_GNAT_Encodings_Minimal : constant Int := 2;
775
776   Identifier_Character_Set : Character;
777   --  GNAT
778   --  This variable indicates the character set to be used for identifiers.
779   --  The possible settings are:
780   --    '1'  Latin-1 (ISO-8859-1)
781   --    '2'  Latin-2 (ISO-8859-2)
782   --    '3'  Latin-3 (ISO-8859-3)
783   --    '4'  Latin-4 (ISO-8859-4)
784   --    '5'  Latin-Cyrillic (ISO-8859-5)
785   --    '9'  Latin-9 (ISO-8859-15)
786   --    'p'  PC (US, IBM page 437)
787   --    '8'  PC (European, IBM page 850)
788   --    'f'  Full upper set (all distinct)
789   --    'n'  No upper characters (Ada 83 rules)
790   --    'w'  Latin-1 plus wide characters allowed in identifiers
791   --
792   --  The setting affects the set of letters allowed in identifiers and the
793   --  upper/lower case equivalences. It does not affect the interpretation of
794   --  character and string literals, which are always stored using the actual
795   --  coding in the source program. This variable is initialized to the
796   --  default value appropriate to the system (in Osint.Initialize), and then
797   --  reset if a command line switch is used to change the setting.
798
799   Ignore_Pragma_SPARK_Mode : Boolean := False;
800   --  GNAT
801   --  Set True to ignore the semantics and effects of pragma SPARK_Mode when
802   --  the pragma appears inside an instance whose enclosing context is subject
803   --  to SPARK_Mode "off".
804
805   Ignore_Rep_Clauses : Boolean := False;
806   --  GNAT
807   --  Set True to ignore all representation clauses. Useful when compiling
808   --  code from foreign compilers for checking or ASIS purposes. Can be
809   --  set True by use of -gnatI.
810
811   Ignore_Style_Checks_Pragmas : Boolean := False;
812   --  GNAT
813   --  Set True to ignore all Style_Checks pragmas. Can be set True by use
814   --  of -gnateY.
815
816   Ignore_Unrecognized_VWY_Switches : Boolean := False;
817   --  GNAT
818   --  Set True to ignore unrecognized y, V, w switches. Can be set True
819   --  by use of -gnateu, causing subsequent unrecognized switches to result
820   --  in a warning rather than an error.
821
822   Implementation_Unit_Warnings : Boolean := True;
823   --  GNAT
824   --  Set True to active warnings for use of implementation internal units.
825   --  Modified by use of -gnatwi/-gnatwI.
826
827   Implicit_Packing : Boolean := False;
828   --  GNAT
829   --  If set True, then a Size attribute clause on an array is allowed to
830   --  cause implicit packing instead of generating an error message. Set by
831   --  use of pragma Implicit_Packing.
832
833   Ineffective_Inline_Warnings : Boolean := False;
834   --  GNAT
835   --  Set True to activate warnings if front-end inlining (-gnatN) is not able
836   --  to actually inline a particular call (or all calls). Can be controlled
837   --  by use of -gnatwp/-gnatwP. Also set True to activate warnings if
838   --  frontend inlining is not able to inline a subprogram expected to
839   --  be inlined in GNATprove mode.
840
841   Init_Or_Norm_Scalars : Boolean := False;
842   --  GNAT, GNATBIND
843   --  Set True if a pragma Initialize_Scalars applies to the current unit.
844   --  Also set True if a pragma Restriction (Normalize_Scalars) applies.
845
846   Initialize_Scalars : Boolean := False;
847   --  GNAT
848   --  Set True if a pragma Initialize_Scalars applies to the current unit.
849   --  Note that Init_Or_Norm_Scalars is also set to True if this is True.
850
851   Initialize_Scalars_Mode1 : Character := 'I';
852   Initialize_Scalars_Mode2 : Character := 'N';
853   --  GNATBIND
854   --  Set to two characters from -S switch (IN/LO/HI/EV/xx). The default
855   --  is IN (invalid values), used if no -S switch is used.
856
857   Inline_Active : Boolean := False;
858   --  GNAT
859   --  Set True to activate pragma Inline processing across modules. Default
860   --  for now is not to inline across module boundaries.
861
862   Inline_Level : Nat := 0;
863   --  GNAT
864   --  Set to indicate the inlining level: 0 means that an appropriate value is
865   --  to be computed by the compiler based on the optimization level (-gnatn),
866   --  1 is for moderate inlining across modules (-gnatn1) and 2 for full
867   --  inlining across modules (-gnatn2).
868
869   Interface_Library_Unit : Boolean := False;
870   --  GNATBIND
871   --  Set to True to indicate that at least one ALI file is an interface ALI:
872   --  then elaboration flag checks are to be generated in the binder
873   --  generated file.
874
875   Invalid_Value_Used : Boolean := False;
876   --  GNAT
877   --  Set True if a valid Invalid_Value attribute is encountered
878
879   Inline_Processing_Required : Boolean := False;
880   --  GNAT
881   --  Set True if inline processing is required. Inline processing is required
882   --  if an active Inline pragma is processed. The flag is set for a pragma
883   --  Inline or Inline_Always that is actually active.
884
885   In_Place_Mode : Boolean := False;
886   --  GNATMAKE
887   --  Set True to store ALI and object files in place i.e. in the object
888   --  directory if these files already exist or in the source directory
889   --  if not.
890
891   Keep_Going : Boolean := False;
892   --  GNATMAKE, GPRBUILD
893   --  When True signals to ignore compilation errors and keep processing
894   --  sources until there is no more work.
895
896   Keep_Temporary_Files : Boolean := False;
897   --  GNATCMD, GNATMAKE, GPRBUILD
898   --  When True the temporary files are not deleted. Set by switches -dn or
899   --  --keep-temp-files.
900
901   Leap_Seconds_Support : Boolean := False;
902   --  GNATBIND
903   --  Set to True to enable leap seconds support in Ada.Calendar and its
904   --  children.
905
906   Link_Only : Boolean := False;
907   --  GNATMAKE, GPRBUILD
908   --  Set to True to skip compile and bind steps (except when Bind_Only is
909   --  set to True).
910
911   List_Body_Required_Info : Boolean := False;
912   --  GNATMAKE
913   --  List info messages about why a package requires a body. Modified by use
914   --  of -gnatw.y/.Y.
915
916   List_Inherited_Aspects : Boolean := False;
917   --  GNAT
918   --  List inherited invariants, preconditions, and postconditions from
919   --  Invariant'Class, Pre'Class, and Post'Class aspects. Also list inherited
920   --  subtype predicates. Modified by use of -gnatw.l/.L.
921
922   List_Restrictions : Boolean := False;
923   --  GNATBIND
924   --  Set to True to list restrictions pragmas that could apply to partition
925
926   List_Units : Boolean := False;
927   --  GNAT
928   --  List units in the active library for a compilation (-gnatu switch)
929
930   List_Closure : Boolean := False;
931   --  GNATBIND
932   --  List all sources in the closure of a main (-R or -Ra gnatbind switch)
933
934   List_Closure_All : Boolean := False;
935   --  GNATBIND
936   --  List all sources in closure of main including run-time units (-Ra
937   --  gnatbind switch).
938
939   List_Dependencies : Boolean := False;
940   --  GNATMAKE
941   --  When True gnatmake verifies that the objects are up to date and outputs
942   --  the list of object dependencies (-M switch). Output depends if -a switch
943   --  is used or not. This list can be used directly in a Makefile.
944
945   List_Representation_Info : Int range 0 .. 3 := 0;
946   --  GNAT
947   --  Set non-zero by -gnatR switch to list representation information.
948   --  The settings are as follows:
949   --
950   --    0 = no listing of representation information (default as above)
951   --    1 = list rep info for user defined record and array types
952   --    2 = list rep info for all user defined types and objects
953   --    3 = like 2, but variable fields are decoded symbolically
954
955   List_Representation_Info_To_File : Boolean := False;
956   --  GNAT
957   --  Set true by -gnatRs switch. Causes information from -gnatR/1/2/3/m to be
958   --  written to file.rep (where file is the name of the source file) instead
959   --  of stdout. For example, if file x.adb is compiled using -gnatR2s then
960   --  representation info is written to x.adb.ref.
961
962   List_Representation_Info_Mechanisms : Boolean := False;
963   --  GNAT
964   --  Set true by -gnatRm switch. Causes information on mechanisms to be
965   --  included in the representation output information.
966
967   List_Preprocessing_Symbols : Boolean := False;
968   --  GNAT, GNATPREP
969   --  Set to True if symbols for preprocessing a source are to be listed
970   --  before preprocessing occurs. Set to True by switch -s of gnatprep or
971   --  -s in preprocessing data file for the compiler.
972
973   type Create_Repinfo_File_Proc is access procedure (Src  : String);
974   type Write_Repinfo_Line_Proc  is access procedure (Info : String);
975   type Close_Repinfo_File_Proc  is access procedure;
976   --  Types used for procedure addresses below
977
978   Create_Repinfo_File_Access : Create_Repinfo_File_Proc := null;
979   Write_Repinfo_Line_Access  : Write_Repinfo_Line_Proc  := null;
980   Close_Repinfo_File_Access  : Close_Repinfo_File_Proc  := null;
981   --  GNAT
982   --  These three locations are left null when operating in non-compiler (e.g.
983   --  ASIS mode), but when operating in compiler mode, they are set to point
984   --  to the three corresponding procedures in Osint-C. The reason for this
985   --  slightly strange interface is to stop Repinfo from dragging in Osint in
986   --  ASIS mode, which would include lots of unwanted units in the ASIS build.
987
988   type Create_List_File_Proc is access procedure (S : String);
989   type Write_List_Info_Proc  is access procedure (S : String);
990   type Close_List_File_Proc  is access procedure;
991   --  Types used for procedure addresses below
992
993   Create_List_File_Access : Create_List_File_Proc := null;
994   Write_List_Info_Access  : Write_List_Info_Proc  := null;
995   Close_List_File_Access  : Close_List_File_Proc  := null;
996   --  GNAT
997   --  These three locations are left null when operating in non-compiler
998   --  (e.g. from the binder), but when operating in compiler mode, they are
999   --  set to point to the three corresponding procedures in Osint-C. The
1000   --  reason for this slightly strange interface is to prevent Repinfo
1001   --  from dragging in Osint-C in the binder, which would include unwanted
1002   --  units in the binder.
1003
1004   Locking_Policy : Character := ' ';
1005   --  GNAT, GNATBIND
1006   --  Set to ' ' for the default case (no locking policy specified). Reset to
1007   --  first character (uppercase) of locking policy name if a valid pragma
1008   --  Locking_Policy is encountered.
1009
1010   Locking_Policy_Sloc : Source_Ptr := No_Location;
1011   --  GNAT, GNATBIND
1012   --  Remember location of previous Locking_Policy pragma. This is used for
1013   --  inconsistency error messages. A value of System_Location is used if the
1014   --  policy is set in package System.
1015
1016   Look_In_Primary_Dir : Boolean := True;
1017   --  GNAT, GNATBIND, GNATMAKE, GNATCLEAN
1018   --  Set to False if a -I- was present on the command line. When True we are
1019   --  allowed to look in the primary directory to locate other source or
1020   --  library files.
1021
1022   Make_Steps : Boolean := False;
1023   --  GNATMAKE
1024   --  Set to True when either Compile_Only, Bind_Only or Link_Only is
1025   --  set to True.
1026
1027   Main_Index : Int := 0;
1028   --  GNATMAKE
1029   --  This is set to non-zero by gnatmake switch -eInnn to indicate that
1030   --  the main program is the nnn unit in a multi-unit source file.
1031
1032   Mapping_File_Name : String_Ptr := null;
1033   --  GNAT
1034   --  File name of mapping between unit names, file names and path names.
1035   --  (given by switch -gnatem)
1036
1037   Maximum_Messages : Int := 9999;
1038   --  GNAT, GNATBIND
1039   --  Maximum default number of errors before compilation is terminated, or in
1040   --  the case of GNAT, maximum number of warnings before further warnings are
1041   --  suppressed. Can be overridden by -gnatm (GNAT) or -m (GNATBIND) switch.
1042
1043   Maximum_File_Name_Length : Int;
1044   --  GNAT, GNATBIND
1045   --  Maximum number of characters allowed in a file name, not counting the
1046   --  extension, as set by the appropriate switch. If no switch is given,
1047   --  then this value is initialized by Osint to the appropriate value.
1048
1049   Maximum_Instantiations : Int := 8000;
1050   --  GNAT
1051   --  Maximum number of instantiations permitted (to stop runaway cases
1052   --  of nested instantiations). These situations probably only occur in
1053   --  specially concocted test cases. Can be modified by -gnateinn switch.
1054
1055   Maximum_Processes : Positive := 1;
1056   --  GNATMAKE, GPRBUILD
1057   --  Maximum number of processes that should be spawned to carry out
1058   --  compilations.
1059
1060   Minimal_Recompilation : Boolean := False;
1061   --  GNATMAKE
1062   --  Set to True if minimal recompilation mode requested
1063
1064   Modify_Tree_For_C : Boolean := False;
1065   --  GNAT
1066   --  If this switch is set True (currently it is set only by -gnatd.V), then
1067   --  certain meaning-preserving transformations are applied to the tree to
1068   --  make it easier to interface with back ends that implement C semantics.
1069   --  There is a section in Sinfo which describes the transformations made.
1070
1071   Multiple_Unit_Index : Int := 0;
1072   --  GNAT
1073   --  This is set non-zero if the current unit is being compiled in multiple
1074   --  unit per file mode, meaning that the current unit is selected from the
1075   --  sequence of units in the current source file, using the value stored
1076   --  in this variable (e.g. 2 = select second unit in file). A value of
1077   --  zero indicates that we are in normal (one unit per file) mode.
1078
1079   No_Backup : Boolean := False;
1080   --  GNATNAME
1081   --  Do not create backup copies of project files. Set by switch --no-backup.
1082
1083   No_Deletion : Boolean := False;
1084   --  GNATPREP
1085   --  Set by preprocessor switch -a. Do not eliminate any source text. Implies
1086   --  Undefined_Symbols_Are_False. Useful to perform a syntax check on all
1087   --  branches of #if constructs.
1088
1089   No_Elab_Code_All_Pragma : Node_Id := Empty;
1090   --  Set to point to a No_Elaboration_Code_All pragma or aspect encountered
1091   --  in the spec of the extended main unit. Used to determine if we need to
1092   --  do special tests for violation of this aspect.
1093
1094   No_Main_Subprogram : Boolean := False;
1095   --  GNATMAKE, GNATBIND
1096   --  Set to True if compilation/binding of a program without main
1097   --  subprogram requested.
1098
1099   No_Run_Time_Mode : Boolean := False;
1100   --  GNAT, GNATBIND
1101   --  This flag is set True if a No_Run_Time pragma is encountered. See spec
1102   --  of Rtsfind for a full description of handling of this pragma.
1103
1104   No_Split_Units : Boolean := False;
1105   --  GPRBUILD
1106   --  Set to True with switch --no-split-units. When True, unit sources, spec,
1107   --  body and subunits, must all be in the same project. This is checked
1108   --  after each compilation.
1109
1110   No_Stdinc : Boolean := False;
1111   --  GNAT, GNATBIND, GNATMAKE, GNATFIND, GNATXREF
1112   --  Set to True if no default source search dirs added to search list.
1113
1114   No_Stdlib : Boolean := False;
1115   --  GNATMAKE, GNATBIND, GNATFIND, GNATXREF
1116   --  Set to True if no default library search dirs added to search list.
1117
1118   No_Strict_Aliasing : Boolean := False;
1119   --  GNAT
1120   --  Set True if pragma No_Strict_Aliasing with no parameters encountered.
1121
1122   No_Tagged_Streams : Node_Id := Empty;
1123   --  GNAT
1124   --  If a pragma No_Tagged_Streams is active for the current scope, this
1125   --  points to the corresponding pragma.
1126
1127   Normalize_Scalars : Boolean := False;
1128   --  GNAT, GNATBIND
1129   --  Set True if a pragma Normalize_Scalars applies to the current unit.
1130   --  Note that Init_Or_Norm_Scalars is also set to True if this is True.
1131
1132   Object_Directory_Present : Boolean := False;
1133   --  GNATMAKE
1134   --  Set to True when an object directory is specified with option -D
1135
1136   Object_Path_File_Name : String_Ptr := null;
1137   --  GNAT2WHY
1138   --  Path of the temporary file that contains a list of object directories
1139   --  passed by -gnateO=<obj_path_file>.
1140
1141   One_Compilation_Per_Obj_Dir : Boolean := False;
1142   --  GNATMAKE, GPRBUILD
1143   --  Set to True with switch --single-compile-per-obj-dir. When True, there
1144   --  cannot be simultaneous compilations with the object files in the same
1145   --  object directory, if project files are used.
1146
1147   type Operating_Mode_Type is (Check_Syntax, Check_Semantics, Generate_Code);
1148   pragma Ordered (Operating_Mode_Type);
1149   Operating_Mode : Operating_Mode_Type := Generate_Code;
1150   --  GNAT
1151   --  Indicates the operating mode of the compiler. The default is generate
1152   --  code, which runs the parser, semantics and backend. Switches can be
1153   --  used to set syntax checking only mode, or syntax and semantics checking
1154   --  only mode. Operating_Mode can also be modified as a result of detecting
1155   --  errors during the compilation process. In particular if any serious
1156   --  error is detected then this flag is reset from Generate_Code to
1157   --  Check_Semantics after generating an error message. This is an ordered
1158   --  type with the semantics that each value does more than the previous one.
1159
1160   Optimize_Alignment : Character := 'O';
1161   --  Setting of Optimize_Alignment, set to T/S/O for time/space/off. Can
1162   --  be modified by use of pragma Optimize_Alignment.
1163
1164   Optimize_Alignment_Local : Boolean := False;
1165   --  Set True if Optimize_Alignment mode is set by a local configuration
1166   --  pragma that overrides the gnat.adc (or other configuration file) default
1167   --  so that the unit is not dependent on the default setting. Also always
1168   --  set True for internal units, since these always have a default setting
1169   --  of Optimize_Alignment (Off) that is enforced (essentially equivalent to
1170   --  them all having such an explicit pragma in each unit).
1171
1172   Original_Operating_Mode : Operating_Mode_Type := Generate_Code;
1173   --  GNAT
1174   --  Indicates the original operating mode of the compiler as set by compiler
1175   --  options. This is identical to Operating_Mode except that this is not
1176   --  affected by errors.
1177
1178   Optimization_Level : Int;
1179   pragma Import (C, Optimization_Level, "optimize");
1180   --  Constant reflecting the optimization level (0,1,2,3 for -O0,-O1,-O2,-O3)
1181   --  See e.g. aamissing.c for definitions for the GNAAMP back end.
1182
1183   Optimize_Size : Int;
1184   pragma Import (C, Optimize_Size, "optimize_size");
1185   --  Constant reflecting setting of -Os (optimize for size). Set to nonzero
1186   --  in -Os mode and set to zero otherwise. See aamissing.c for definition
1187   --  of "optimize_size" for the GNAAMP backend.
1188
1189   Output_File_Name_Present : Boolean := False;
1190   --  GNATBIND, GNAT, GNATMAKE
1191   --  Set to True when the output C file name is given with option -o for
1192   --  GNATBIND, when the object file name is given with option -gnatO for GNAT
1193   --  or when the executable is given with option -o for GNATMAKE.
1194
1195   Output_Linker_Option_List : Boolean := False;
1196   --  GNATBIND
1197   --  True if output of list of linker options is requested (-K switch set)
1198
1199   Output_ALI_List   : Boolean := False;
1200   ALI_List_Filename : String_Ptr;
1201   --  GNATBIND
1202   --  True if output of list of ALIs is requested (-A switch set). List is
1203   --  output under the given filename, or standard output if not specified.
1204
1205   Output_Object_List   : Boolean := False;
1206   Object_List_Filename : String_Ptr;
1207   --  GNATBIND
1208   --  True if output of list of objects is requested (-O switch set). List is
1209   --  output under the given filename, or standard output if not specified.
1210
1211   Partition_Elaboration_Policy : Character := ' ';
1212   --  GNAT, GNATBIND
1213   --  Set to ' ' for the default case (no elaboration policy specified). Reset
1214   --  to first character (uppercase) of locking policy name if a valid pragma
1215   --  Partition_Elaboration_Policy is encountered.
1216
1217   Partition_Elaboration_Policy_Sloc : Source_Ptr := No_Location;
1218   --  GNAT, GNATBIND
1219   --  Remember location of previous Partition_Elaboration_Policy pragma. This
1220   --  is used for inconsistency error messages. A value of System_Location is
1221   --  used if the policy is set in package System.
1222
1223   Persistent_BSS_Mode : Boolean := False;
1224   --  GNAT
1225   --  True if a Persistent_BSS configuration pragma is in effect, causing
1226   --  potentially persistent data to be placed in the persistent_bss section.
1227
1228   Pessimistic_Elab_Order : Boolean := False;
1229   --  GNATBIND
1230   --  True if pessimistic elaboration order is to be chosen (-p switch set)
1231
1232   Polling_Required : Boolean := False;
1233   --  GNAT
1234   --  Set to True if polling for asynchronous abort is enabled by using
1235   --  the -gnatP option for GNAT.
1236
1237   Prefix_Exception_Messages : Boolean := False;
1238   --  GNAT
1239   --  Set True to prefix exception messages with entity-name:
1240
1241   Preprocessing_Data_File : String_Ptr := null;
1242   --  GNAT
1243   --  Set by switch -gnatep=. The file name of the preprocessing data file.
1244
1245   Preprocessing_Symbol_Defs : String_List_Access := new String_List (1 .. 4);
1246   --  An extensible array to temporarily stores symbol definitions specified
1247   --  on the command line with -gnateD switches. The value 4 is an arbitrary
1248   --  starting point, if more space is needed it is allocated as required.
1249
1250   Preprocessing_Symbol_Last : Natural := 0;
1251   --  Index of last symbol definition in array Symbol_Definitions
1252
1253   Print_Generated_Code : Boolean := False;
1254   --  GNAT
1255   --  Set to True to enable output of generated code in source form. This
1256   --  flag is set by the -gnatG switch.
1257
1258   Print_Standard : Boolean := False;
1259   --  GNAT
1260   --  Set to true to enable printing of package standard in source form.
1261   --  This flag is set by the -gnatS switch
1262
1263   type Usage is (Unknown, Not_In_Use, In_Use);
1264   Project_File_In_Use : Usage := Unknown;
1265   --  GNAT
1266   --  Indicates if a project file is used or not. Set to In_Use by the first
1267   --  SFNP pragma.
1268
1269   Queuing_Policy : Character := ' ';
1270   --  GNAT, GNATBIND
1271   --  Set to ' ' for the default case (no queuing policy specified). Reset to
1272   --  first character (uppercase) of locking policy name if a valid
1273   --  Queuing_Policy pragma is encountered.
1274
1275   Queuing_Policy_Sloc : Source_Ptr := No_Location;
1276   --  GNAT, GNATBIND
1277   --  Remember location of previous Queuing_Policy pragma. This is used for
1278   --  inconsistency error messages. A value of System_Location is used if the
1279   --  policy is set in package System.
1280
1281   Quiet_Output : Boolean := False;
1282   --  GNATMAKE, GNATCLEAN, GPRBUILD, GPRCLEAN
1283   --  Set to True if the tool should not have any output if there are no
1284   --  errors or warnings.
1285
1286   Overriding_Renamings : Boolean := False;
1287   --  GNAT
1288   --  Set to True to enable compatibility mode with Rational compiler, and
1289   --  to accept renamings of implicit operations in their own scope.
1290
1291   Relaxed_RM_Semantics : Boolean := False;
1292   --  GNAT
1293   --  Set to True to ignore some Ada semantic error to help parse legacy Ada
1294   --  code for use in e.g. static analysis (such as CodePeer). This deals
1295   --  with cases where other compilers allow illegal constructs. Tools such as
1296   --  CodePeer are interested in analyzing code rather than enforcing legality
1297   --  rules, so as long as these illegal constructs end up with code that can
1298   --  be handled by the tool in question, there is no reason to reject the
1299   --  code that is considered correct by the other compiler.
1300
1301   Replace_In_Comments : Boolean := False;
1302   --  GNATPREP
1303   --  Set to True if -C switch used.
1304
1305   RTS_Lib_Path_Name : String_Ptr := null;
1306   RTS_Src_Path_Name : String_Ptr := null;
1307   --  GNAT
1308   --  Set to the "adalib" and "adainclude" directories of the run time
1309   --  specified by --RTS=.
1310
1311   RTS_Switch : Boolean := False;
1312   --  GNAT, GNATMAKE, GNATBIND, GNATLS, GNATFIND, GNATXREF
1313   --  Set to True when the --RTS switch is set
1314
1315   Run_Path_Option : Boolean := True;
1316   --  GNATMAKE, GNATLINK
1317   --  Set to False when no run_path_option should be issued to the linker
1318
1319   Search_Directory_Present : Boolean := False;
1320   --  GNAT
1321   --  Set to True when argument is -I. Reset to False when next argument, a
1322   --  search directory path is taken into account. Note that this is quite
1323   --  different from other switches in this section in that it is only set in
1324   --  a transitory manner as a result of scanning a -I switch with no file
1325   --  name, and if set, is an indication that the next argument is to be
1326   --  treated as a file name.
1327
1328   Sec_Stack_Used : Boolean := False;
1329   --  GNAT, GBATBIND
1330   --  Set True if generated code uses the System.Secondary_Stack package. For
1331   --  the binder, set if any unit uses the secondary stack package.
1332
1333   Setup_Projects : Boolean := False;
1334   --  GNAT DRIVER
1335   --  Set to True for GNAT SETUP: the Project Manager creates nonexistent
1336   --  object, library, and exec directories.
1337
1338   Shared_Libgnat : Boolean;
1339   --  GNATBIND
1340   --  Set to True if a shared libgnat is requested by using the -shared option
1341   --  for GNATBIND and to False when using the -static option. The value of
1342   --  this flag is set by Gnatbind.Scan_Bind_Arg.
1343
1344   Short_Circuit_And_Or : Boolean := False;
1345   --  GNAT
1346   --  Set True if a pragma Short_Circuit_And_Or applies to the current unit.
1347
1348   type SPARK_Mode_Type is (None, Off, On);
1349   --  Possible legal modes that can be set by aspect/pragma SPARK_Mode, as
1350   --  well as the value None, which indicates no such pragma/aspect applies.
1351
1352   SPARK_Mode : SPARK_Mode_Type := None;
1353   --  GNAT
1354   --  Current SPARK mode setting.
1355
1356   SPARK_Mode_Pragma : Node_Id := Empty;
1357   --  GNAT
1358   --  If the current SPARK_Mode (above) was set by a pragma, this records
1359   --  the pragma that set this mode.
1360
1361   SPARK_Switches_File_Name : String_Ptr := null;
1362   --  GNAT
1363   --  Set to non-null file name by use of the -gnates switch to specify
1364   --  SPARK (gnat2why) specific switches in the given file name.
1365
1366   Special_Exception_Package_Used : Boolean := False;
1367   --  GNAT
1368   --  Set to True if either of the unit GNAT.Most_Recent_Exception or
1369   --  GNAT.Exception_Traces is with'ed. Used to inhibit transformation of
1370   --  local raise statements into gotos in the presence of either package.
1371
1372   Sprint_Line_Limit : Nat := 72;
1373   --  GNAT
1374   --  Limit values for chopping long lines in Cprint/Sprint output, can be
1375   --  reset by use of NNN parameter with -gnatG or -gnatD switches.
1376
1377   Stack_Checking_Enabled : Boolean := False;
1378   --  GNAT
1379   --  Set to indicate if stack checking is enabled for the compilation. This
1380   --  is set directly from the value in the gcc back end in the body of the
1381   --  gcc version of back_end.adb.
1382
1383   Style_Check : Boolean := False;
1384   --  GNAT
1385   --  Set True to perform style checks. Activates checks carried out in
1386   --  package Style (see body of this package for details of checks). This
1387   --  flag is set True by use of either the -gnatg or -gnaty switches, or
1388   --  by the Style_Check pragma.
1389
1390   Style_Check_Main : Boolean := False;
1391   --  GNAT
1392   --  Set True if Style_Check was set for the main unit. This is used to
1393   --  enable style checks for units in the main extended source that get
1394   --  with'ed indirectly. It is set True by use of either the -gnatg or
1395   --  -gnaty switches, but not by use of the Style_Checks pragma.
1396
1397   Disable_FE_Inline        : Boolean := False;
1398   Disable_FE_Inline_Always : Boolean := False;
1399   --  GNAT
1400   --  Request to disable front end inlining from pragma Inline or pragma
1401   --  Inline_Always out of the presence of the -fno-inline back end flag
1402   --  on the command line, regardless of any other switches that are set.
1403   --  It remains the back end's reponsibility to honor -fno-inline at the
1404   --  back end level.
1405
1406   Suppress_Control_Flow_Optimizations : Boolean := False;
1407   --  GNAT
1408   --  Set by -fpreserve-control-flow. Suppresses control flow optimizations
1409   --  that interfere with coverage analysis based on the object code.
1410
1411   System_Extend_Pragma_Arg : Node_Id := Empty;
1412   --  GNAT
1413   --  Set non-empty if and only if a correct Extend_System pragma was present
1414   --  in which case it points to the argument of the pragma, and the name can
1415   --  be located as Chars (Expression (System_Extend_Pragma_Arg)).
1416
1417   System_Extend_Unit : Node_Id := Empty;
1418   --  GNAT
1419   --  This is set to Empty if GNAT_Mode is set, since pragma Extend_System
1420   --  is never appropriate in GNAT_Mode (and causes troubles, including
1421   --  bogus circularities, if we try to compile the run-time library with
1422   --  a System extension). If GNAT_Mode is not set, then System_Extend_Unit
1423   --  is a copy of the value set in System_Extend_Pragma_Arg.
1424
1425   Subunits_Missing : Boolean := False;
1426   --  GNAT
1427   --  This flag is set true if missing subunits are detected with code
1428   --  generation active. This causes code generation to be skipped.
1429
1430   Suppress_Checks : Boolean := False;
1431   --  GNAT
1432   --  Set to True if -gnatp (suppress all checks) switch present.
1433
1434   Suppress_Options : Suppress_Record;
1435   --  GNAT
1436   --  Indicates outer level setting of check suppression. This initializes
1437   --  the settings of the outer scope level in any unit compiled. This is
1438   --  initialized by Osint.Initialize, and further initialized by the
1439   --  Adjust_Global_Switches flag in Gnat1drv.
1440
1441   Table_Factor : Int := 1;
1442   --  GNAT
1443   --  Factor by which all initial table sizes set in Alloc are multiplied.
1444   --  Used in Table to calculate initial table sizes (the initial table size
1445   --  is the value in Alloc, used as the Table_Initial parameter value,
1446   --  multiplied by the factor given here. The default value is used if no
1447   --  -gnatT switch appears.
1448
1449   Tagged_Type_Expansion : Boolean := True;
1450   --  GNAT
1451   --  Set True if tagged types and interfaces should be expanded by the
1452   --  front-end. If False, the original tree is left unexpanded for tagged
1453   --  types and dispatching calls, assuming the underlying target supports it.
1454
1455   Target_Dependent_Info_Read_Name : String_Ptr := null;
1456   --  GNAT
1457   --  Set non-null to override the normal processing in Get_Targ and set the
1458   --  necessary information by reading the target dependent information file
1459   --  whose name is given here (see packages Get_Targ and Set_Targ for full
1460   --  details). Set to non-null file name by use of the -gnateT switch.
1461
1462   Target_Dependent_Info_Write_Name : String_Ptr := null;
1463   --  GNAT
1464   --  Set non-null to enable a call to Set_Targ.Write_Target_Dependent_Info
1465   --  which writes a target independent information file (see packages
1466   --  Get_Targ and Set_Targ for full details) using the name given by
1467   --  this switch. Set to non-null file name by use of the -gnatet switch.
1468
1469   type Origin_Of_Target is (Unknown, Default, Specified);
1470
1471   Target_Origin : Origin_Of_Target := Unknown;
1472   --  GPRBUILD
1473   --  Indicates the origin of attribute Target in project files
1474
1475   Target_Value : String_Access := null;
1476   --  GPRBUILD
1477   --  Indicates the value of attribute Target in project files
1478
1479   Task_Dispatching_Policy : Character := ' ';
1480   --  GNAT, GNATBIND
1481   --  Set to ' ' for the default case (no task dispatching policy specified).
1482   --  Reset to first character (uppercase) of task dispatching policy name
1483   --  if a valid Task_Dispatching_Policy pragma is encountered.
1484
1485   Task_Dispatching_Policy_Sloc : Source_Ptr := No_Location;
1486   --  GNAT, GNATBIND
1487   --  Remember location of previous Task_Dispatching_Policy pragma. This is
1488   --  used for inconsistency error messages. A value of System_Location is
1489   --  used if the policy is set in package System.
1490
1491   Tasking_Used : Boolean := False;
1492   --  Set True if any tasking construct is encountered. Used to activate the
1493   --  output of the Q, L and T lines in ALI files.
1494
1495   Time_Slice_Set : Boolean := False;
1496   --  GNATBIND
1497   --  Set True if a pragma Time_Slice is processed in the main unit, or
1498   --  if the -gnatTnn switch is present to set a time slice value.
1499
1500   Time_Slice_Value : Nat;
1501   --  GNATBIND
1502   --  Time slice value. Valid only if Time_Slice_Set is True, i.e. if
1503   --  Time_Slice pragma has been processed. Set to the time slice value in
1504   --  microseconds. Negative values are stored as zero, and the value is not
1505   --  larger than 1_000_000_000 (1000 seconds). Values larger than this are
1506   --  reset to this maximum. This can also be set with the -gnatTnn switch.
1507
1508   Tolerate_Consistency_Errors : Boolean := False;
1509   --  GNATBIND
1510   --  Tolerate time stamp and other consistency errors. If this flag is set to
1511   --  True (-t), then inconsistencies result in warnings rather than errors.
1512
1513   Treat_Categorization_Errors_As_Warnings : Boolean := False;
1514   --  Normally categorization errors are true illegalities. If this switch
1515   --  is set, then such errors result in warning messages rather than error
1516   --  messages. Set True by -gnateP (P for Pure/Preelaborate). Also set in
1517   --  Relaxed_RM_Semantics mode since some old Ada 83 compilers treated
1518   --  pragma Preelaborate differently.
1519
1520   Treat_Restrictions_As_Warnings : Boolean := False;
1521   --  GNAT
1522   --  Set True to treat pragma Restrictions as Restriction_Warnings. Set by
1523   --  -gnatr switch.
1524
1525   Tree_Output : Boolean := False;
1526   --  GNAT
1527   --  Set to True (-gnatt) to generate output tree file
1528
1529   Try_Semantics : Boolean := False;
1530   --  GNAT
1531   --  Flag set to force attempt at semantic analysis, even if parser errors
1532   --  occur. This will probably cause blowups at this stage in the game. On
1533   --  the other hand, most such blowups will be caught cleanly and simply
1534   --  say compilation abandoned. This flag is set True by -gnatq or -gnatQ.
1535
1536   Unchecked_Shared_Lib_Imports : Boolean := False;
1537   --  GPRBUILD
1538   --  Set to True when shared library projects are allowed to import projects
1539   --  that are not shared library projects. Set on by use of the switch
1540   --  --unchecked-shared-lib-imports.
1541
1542   Undefined_Symbols_Are_False : Boolean := False;
1543   --  GNAT, GNATPREP
1544   --  Set to True by switch -u of gnatprep or -u in the preprocessing data
1545   --  file for the compiler. Indicates that while preprocessing sources,
1546   --  symbols that are not defined have the value FALSE.
1547
1548   Uneval_Old : Character := 'E';
1549   --  GNAT
1550   --  Set to 'E'/'W'/'A' for use of Error/Warn/Allow in a valid pragma
1551   --  Unevaluated_Use_Of_Old. Default in the absence of the pragma is 'E'
1552   --  for the RM default behavior of giving an error.
1553
1554   Unique_Error_Tag : Boolean := Tag_Errors;
1555   --  GNAT
1556   --  Indicates if error messages are to be prefixed by the string error:
1557   --  Initialized from Tag_Errors, can be forced on with the -gnatU switch.
1558
1559   Unnest_Subprogram_Mode : Boolean := False;
1560   --  If true, activates the circuitry for unnesting subprograms (see the spec
1561   --  of Exp_Unst for full details). Currently set only by use of -gnatd.1.
1562
1563   Universal_Addressing_On_AAMP : Boolean := False;
1564   --  GNAAMP
1565   --  Indicates if library-level objects should be accessed and updated using
1566   --  universal addressing instructions on the AAMP architecture. This flag is
1567   --  set to True when pragma Universal_Data is given as a configuration
1568   --  pragma.
1569
1570   Unreserve_All_Interrupts : Boolean := False;
1571   --  GNAT, GNATBIND
1572   --  Normally set False, set True if a valid Unreserve_All_Interrupts pragma
1573   --  appears anywhere in the main unit for GNAT, or if any ALI file has the
1574   --  corresponding attribute set in GNATBIND.
1575
1576   Upper_Half_Encoding : Boolean := False;
1577   --  GNAT, GNATBIND
1578   --  Normally set False, indicating that upper half ISO 8859-1 characters are
1579   --  used in the normal way to represent themselves. If the wide character
1580   --  encoding method uses the upper bit for this encoding, then this flag is
1581   --  set True, and upper half characters in the source indicate the start of
1582   --  a wide character sequence. Set by -gnatW or -W switches.
1583
1584   Use_Include_Path_File : Boolean := False;
1585   --  GNATMAKE, GPRBUILD
1586   --  When True, create a source search path file, even when a mapping file
1587   --  is used.
1588
1589   Usage_Requested : Boolean := False;
1590   --  GNAT, GNATBIND, GNATMAKE
1591   --  Set to True if -h (-gnath for the compiler) switch encountered
1592   --  requesting usage information
1593
1594   Use_Pragma_Linker_Constructor : Boolean := False;
1595   --  GNATBIND
1596   --  True if pragma Linker_Constructor applies to adainit
1597
1598   Use_VADS_Size : Boolean := False;
1599   --  GNAT
1600   --  Set to True if a valid pragma Use_VADS_Size is processed
1601
1602   Validity_Checks_On  : Boolean := True;
1603   --  GNAT
1604   --  This flag determines if validity checking is on or off. The initial
1605   --  state is on, and the required default validity checks are active. The
1606   --  actual set of checks that is performed if Validity_Checks_On is set is
1607   --  defined by the switches in package Validsw. The Validity_Checks_On flag
1608   --  is controlled by pragma Validity_Checks (On | Off), and also some
1609   --  generated compiler code (typically code that has to do with validity
1610   --  check generation) is compiled with this flag set to False. This flag is
1611   --  set to False by the -gnatp switch.
1612
1613   Verbose_Mode : Boolean := False;
1614   --  GNAT, GNATBIND, GNATMAKE, GNATLINK, GNATLS, GNATNAME, GNATCLEAN,
1615   --  GPRBUILD, GPRCLEAN
1616   --  Set to True to get verbose mode (full error message text and location
1617   --  information sent to standard output, also header, copyright and summary)
1618
1619   type Verbosity_Level_Type is (None, Low, Medium, High);
1620   pragma Ordered (Verbosity_Level_Type);
1621   Verbosity_Level : Verbosity_Level_Type := High;
1622   --  GNATMAKE
1623   --  Modified by gnatmake switches -v, -vl, -vm, -vh. Indicates
1624   --  the level of verbosity of informational messages:
1625   --
1626   --  In Low Verbosity, the reasons why a source is recompiled, the name
1627   --  of the executable and the reason it must be rebuilt is output.
1628   --
1629   --  In Medium Verbosity, additional lines are output for each ALI file
1630   --  that is checked.
1631   --
1632   --  In High Verbosity, additional lines are output when the ALI file
1633   --  is part of an Ada library, is read-only or is part of the runtime.
1634
1635   Warn_On_Ada_2005_Compatibility : Boolean := True;
1636   --  GNAT
1637   --  Set to True to generate all warnings on Ada 2005 compatibility issues,
1638   --  including warnings on Ada 2005 obsolescent features used in Ada 2005
1639   --  mode. Set by default, modified by use of -gnatwy/Y.
1640
1641   Warn_On_Ada_2012_Compatibility : Boolean := True;
1642   --  GNAT
1643   --  Set to True to generate all warnings on Ada 2012 compatibility issues,
1644   --  including warnings on Ada 2012 obsolescent features used in Ada 2012
1645   --  mode. Modified by use of -gnatwy/Y.
1646
1647   Warn_On_All_Unread_Out_Parameters : Boolean := False;
1648   --  GNAT
1649   --  Set to True to generate warnings in all cases where a variable is
1650   --  modified by being passed as to an OUT formal, but the resulting value is
1651   --  never read. The default is that this warning is suppressed. Modified
1652   --  by use of gnatw.o/.O.
1653
1654   Warn_On_Assertion_Failure : Boolean := True;
1655   --  GNAT
1656   --  Set to True to activate warnings on assertions that can be determined
1657   --  at compile time will always fail. Modified by use of -gnatw.a/.A.
1658
1659   Warn_On_Assumed_Low_Bound : Boolean := True;
1660   --  GNAT
1661   --  Set to True to activate warnings for string parameters that are indexed
1662   --  with literals or S'Length, presumably assuming a lower bound of one.
1663   --  Modified by use of -gnatww/W.
1664
1665   Warn_On_Atomic_Synchronization : Boolean := False;
1666   --  GNAT
1667   --  Set to True to generate information messages for atomic synchronization.
1668   --  Modified by use of -gnatw.n/.N.
1669
1670   Warn_On_Bad_Fixed_Value : Boolean := False;
1671   --  GNAT
1672   --  Set to True to generate warnings for static fixed-point expression
1673   --  values that are not an exact multiple of the small value of the type.
1674   --  Odd by default, modified by use of -gnatwb/B.
1675
1676   Warn_On_Biased_Representation : Boolean := True;
1677   --  GNAT
1678   --  Set to True to generate warnings for size clauses, component clauses
1679   --  and component_size clauses that force biased representation. Modified
1680   --  by use of -gnatw.b/.B.
1681
1682   Warn_On_Constant : Boolean := False;
1683   --  GNAT
1684   --  Set to True to generate warnings for variables that could be declared
1685   --  as constants. Modified by use of -gnatwk/K.
1686
1687   Warn_On_Deleted_Code : Boolean := False;
1688   --  GNAT
1689   --  Set to True to generate warnings for code deleted by the front end
1690   --  for conditional statements whose outcome is known at compile time.
1691   --  Modified by use of -gnatwt/T.
1692
1693   Warn_On_Dereference : Boolean := False;
1694   --  GNAT
1695   --  Set to True to generate warnings for implicit dereferences for array
1696   --  indexing and record component access. Modified by use of -gnatwd/D.
1697
1698   Warn_On_Export_Import : Boolean := True;
1699   --  GNAT
1700   --  Set to True to generate warnings for suspicious use of export or
1701   --  import pragmas. Modified by use of -gnatwx/X.
1702
1703   Warn_On_Elab_Access : Boolean := False;
1704   --  GNAT
1705   --  Set to True to generate warnings for P'Access in the case where
1706   --  subprogram P is in the same package as the P'Access, and the P'Access is
1707   --  evaluated at package elaboration time, and occurs before the body of P
1708   --  has been elaborated.
1709
1710   Warn_On_Hiding : Boolean := False;
1711   --  GNAT
1712   --  Set to True to generate warnings if a declared entity hides another
1713   --  entity. The default is that this warning is suppressed. Modified by
1714   --  use of -gnatwh/H.
1715
1716   Warn_On_Modified_Unread : Boolean := False;
1717   --  GNAT
1718   --  Set to True to generate warnings if a variable is assigned but is never
1719   --  read. Also controls warnings for similar cases involving out parameters,
1720   --  but only if there is only one out parameter for the procedure involved.
1721   --  The default is that this warning is suppressed, modified by use of
1722   --  -gnatwm/M.
1723
1724   Warn_On_No_Value_Assigned : Boolean := True;
1725   --  GNAT
1726   --  Set to True to generate warnings if no value is ever assigned to a
1727   --  variable that is at least partially uninitialized. Set to false to
1728   --  suppress such warnings. The default is that such warnings are enabled.
1729   --  Modified by use of -gnatwv/V.
1730
1731   Warn_On_Non_Local_Exception : Boolean := False;
1732   --  GNAT
1733   --  Set to True to generate warnings for non-local exception raises and also
1734   --  handlers that can never handle a local raise. This warning is only ever
1735   --  generated if pragma Restrictions (No_Exception_Propagation) is set. The
1736   --  default is not to generate the warnings except that if the source has
1737   --  at least one exception handler, and this restriction is set, and the
1738   --  warning was not explicitly turned off, then it is turned on by default.
1739   --  Modified by use of -gnatw.x/.X.
1740
1741   No_Warn_On_Non_Local_Exception : Boolean := False;
1742   --  GNAT
1743   --  This is set to True if the above warning is explicitly suppressed. We
1744   --  use this to avoid turning it on by default when No_Exception_Propagation
1745   --  restriction is set and an exception handler is present.
1746
1747   Warn_On_Object_Renames_Function : Boolean := False;
1748   --  GNAT
1749   --  Set to True to generate warnings when a function result is renamed as
1750   --  an object. The default is that this warning is disabled. Modified by
1751   --  use of -gnatw.r/.R.
1752
1753   Warn_On_Obsolescent_Feature : Boolean := False;
1754   --  GNAT
1755   --  Set to True to generate warnings on use of any feature in Annex or if a
1756   --  subprogram is called for which a pragma Obsolescent applies. Modified
1757   --  by use of -gnatwj/J.
1758
1759   Warn_On_Overlap : Boolean := False;
1760   --  GNAT
1761   --  Set to True to generate warnings when a writable actual overlaps with
1762   --  another actual in a subprogram call. This applies only in modes before
1763   --  Ada 2012. Starting with Ada 2012, such overlaps are illegal.
1764   --  Modified by use of -gnatw.i/.I.
1765
1766   Warn_On_Questionable_Missing_Parens : Boolean := True;
1767   --  GNAT
1768   --  Set to True to generate warnings for cases where parentheses are missing
1769   --  and the usage is questionable, because the intent is unclear. On by
1770   --  default, modified by use of -gnatwq/Q.
1771
1772   Warn_On_Parameter_Order : Boolean := False;
1773   --  GNAT
1774   --  Set to True to generate warnings for cases where the argument list for
1775   --  a call is a sequence of identifiers that match the formal identifiers,
1776   --  but are in the wrong order.
1777
1778   Warn_On_Redundant_Constructs : Boolean := False;
1779   --  GNAT
1780   --  Set to True to generate warnings for redundant constructs (e.g. useless
1781   --  assignments/conversions). The default is that this warning is disabled.
1782   --  Modified by use of -gnatwr/R.
1783
1784   Warn_On_Reverse_Bit_Order : Boolean := True;
1785   --  GNAT
1786   --  Set to True to generate warning (informational) messages for component
1787   --  clauses that are affected by non-standard bit-order. The default is
1788   --  that this warning is enabled. Modified by -gnatw.v/.V.
1789
1790   Warn_On_Suspicious_Contract : Boolean := True;
1791   --  GNAT
1792   --  Set to True to generate warnings for suspicious contracts expressed as
1793   --  pragmas or aspects precondition and postcondition, as well as other
1794   --  suspicious cases of expressions typically found in contracts like
1795   --  quantified expressions and uses of Update attribute. The default is that
1796   --  this warning is enabled. Modified by use of -gnatw.t/.T.
1797
1798   Warn_On_Suspicious_Modulus_Value : Boolean := True;
1799   --  GNAT
1800   --  Set to True to generate warnings for suspicious modulus values. The
1801   --  default is that this warning is enabled. Modified by -gnatw.m/.M.
1802
1803   Warn_On_Unchecked_Conversion : Boolean := True;
1804   --  GNAT
1805   --  Set to True to generate warnings for unchecked conversions that may have
1806   --  non-portable semantics (e.g. because sizes of types differ). Modified
1807   --  by use of -gnatwz/Z.
1808
1809   Warn_On_Unordered_Enumeration_Type : Boolean := False;
1810   --  GNAT
1811   --  Set to True to generate warnings for inappropriate uses (comparisons
1812   --  and explicit ranges) on unordered enumeration types (which includes
1813   --  all enumeration types for which pragma Ordered is not given). The
1814   --  default is that this warning is disabled. Modified by -gnat.u/.U.
1815
1816   Warn_On_Unrecognized_Pragma : Boolean := True;
1817   --  GNAT
1818   --  Set to True to generate warnings for unrecognized pragmas. The default
1819   --  is that this warning is enabled. Modified by use of -gnatwg/G.
1820
1821   Warn_On_Unrepped_Components : Boolean := False;
1822   --  GNAT
1823   --  Set to True to generate warnings for the case of components of record
1824   --  which have a record representation clause but this component does not
1825   --  have a component clause. Modified by use of -gnatw.c/.C.
1826
1827   Warn_On_Warnings_Off : Boolean := False;
1828   --  GNAT
1829   --  Set to True to generate warnings for use of Pragma Warnings (Off, ent),
1830   --  where either the pragma is never used, or it could be replaced by a
1831   --  pragma Unmodified or Unreferenced. Also generates warnings for pragma
1832   --  Warning (Off, string) which either has no matching pragma Warning On,
1833   --  or where no warning has been suppressed by the use of the pragma.
1834   --  Modified by use of -gnatw.w/.W.
1835
1836   type Warning_Mode_Type is (Suppress, Normal, Treat_As_Error);
1837   Warning_Mode : Warning_Mode_Type := Normal;
1838   --  GNAT, GNATBIND
1839   --  Controls treatment of warning messages. If set to Suppress, warning
1840   --  messages are not generated at all. In Normal mode, they are generated
1841   --  but do not count as errors. In Treat_As_Error mode, warning messages are
1842   --  generated and are treated as errors. Note that Warning_Mode = Suppress
1843   --  causes pragma Warnings to be ignored (except for legality checks),
1844   --  unless we are in GNATprove_Mode, which requires pragma Warnings to
1845   --  be stored for the formal verification backend.
1846
1847   Warnings_As_Errors_Count : Natural;
1848   --  GNAT
1849   --  Number of entries stored in Warnings_As_Errors table
1850
1851   Wide_Character_Encoding_Method : WC_Encoding_Method := WCEM_Brackets;
1852   --  GNAT, GNATBIND
1853   --  Method used for encoding wide characters in the source program. See
1854   --  description of type in unit System.WCh_Con for a list of the methods
1855   --  that are currently supported. Note that brackets notation is always
1856   --  recognized in source programs regardless of the setting of this
1857   --  variable. The default setting causes only the brackets notation to be
1858   --  recognized. If this is the main unit, this setting also controls the
1859   --  output of the W=? parameter in the ALI file, which is used to provide
1860   --  the default for encoding [Wide_[Wide_]]Text_IO files. For the binder,
1861   --  the value set here overrides this main unit default.
1862
1863   Wide_Character_Encoding_Method_Specified : Boolean := False;
1864   --  GNAT, GNATBIND
1865   --  Set True if the value in Wide_Character_Encoding_Method was set as
1866   --  a result of an explicit -gnatW? or -W? switch. False otherwise.
1867
1868   Xref_Active : Boolean := True;
1869   --  GNAT
1870   --  Set if cross-referencing is enabled (i.e. xref info in ALI files)
1871
1872   Zero_Formatting : Boolean := False;
1873   --  GNATBIND
1874   --  Do no formatting (no title, no leading spaces, no empty lines) in
1875   --  auxiliary outputs (-e, -K, -l, -R).
1876
1877   ----------------------------
1878   -- Configuration Settings --
1879   ----------------------------
1880
1881   --  These are settings that are used to establish the mode at the start of
1882   --  each unit. The values defined below can be affected either by command
1883   --  line switches, or by the use of appropriate configuration pragmas in a
1884   --  configuration pragma file (but NOT by a local use of a configuration
1885   --  pragma in a single file).
1886
1887   Ada_Version_Config : Ada_Version_Type;
1888   --  GNAT
1889   --  This is the value of the configuration switch for the Ada 83 mode, as
1890   --  set by the command line switches -gnat83/95/2005/2012, and possibly
1891   --  modified by the use of configuration pragmas Ada_*. This switch is used
1892   --  to set the initial value for Ada_Version mode at the start of analysis
1893   --  of a unit.  Note however that the setting of this flag is ignored for
1894   --  internal and predefined units (which are always compiled in the most up
1895   --  to date version of Ada).
1896
1897   Ada_Version_Pragma_Config : Node_Id;
1898   --  This will be set nonempty if it is set by a configuration pragma
1899
1900   Ada_Version_Explicit_Config : Ada_Version_Type;
1901   --  GNAT
1902   --  This is set in the same manner as Ada_Version_Config. The difference is
1903   --  that the setting of this flag is not ignored for internal and predefined
1904   --  units, which for some purposes do indeed access this value, regardless
1905   --  of the fact that they are compiled the most up to date ada version).
1906
1907   Assertions_Enabled_Config : Boolean;
1908   --  GNAT
1909   --  This is the value of the configuration switch for assertions enabled
1910   --  mode, as possibly set by the command line switch -gnata, and possibly
1911   --  modified by the use of the configuration pragma Assertion_Policy.
1912
1913   Assume_No_Invalid_Values_Config : Boolean;
1914   --  GNAT
1915   --  This is the value of the configuration switch for assuming "no invalid
1916   --  values enabled" mode, as possibly set by the command line switch
1917   --  -gnatB, and possibly modified by the use of the configuration pragma
1918   --  Assume_No_Invalid_Values.
1919
1920   Check_Float_Overflow_Config : Boolean;
1921   --  GNAT
1922   --  Set to True to check that operations on predefined unconstrained float
1923   --  types (e.g. Float, Long_Float) do not overflow and generate infinities
1924   --  or invalid values. Set by the Check_Float_Overflow pragma, or by use
1925   --  of the -gnateF switch.
1926
1927   Check_Policy_List_Config : Node_Id;
1928   --  GNAT
1929   --  This points to the list of N_Pragma nodes for Check_Policy pragmas
1930   --  that are linked through the Next_Pragma fields, with the list being
1931   --  terminated by Empty. The order is most recently processed first. This
1932   --  list includes only those pragmas in configuration pragma files.
1933
1934   Default_Pool_Config : Node_Id := Empty;
1935   --  GNAT
1936   --  Same as Default_Pool above, except this is only for Default_Storage_Pool
1937   --  pragmas that are configuration pragmas.
1938
1939   Default_SSO_Config : Character := ' ';
1940   --  GNAT
1941   --  Set if a pragma Default_Scalar_Storage_Order appears as a configuration
1942   --  pragma. A value of ' ' means that no pragma was given, otherwise the
1943   --  value is 'H' for High_Order_First or 'L' for Low_Order_First.
1944
1945   Dynamic_Elaboration_Checks_Config : Boolean := False;
1946   --  GNAT
1947   --  Set True for dynamic elaboration checking mode, as set by the -gnatE
1948   --  switch or by the use of pragma Elaboration_Checking (Dynamic).
1949
1950   Exception_Locations_Suppressed_Config : Boolean := False;
1951   --  GNAT
1952   --  Set True by use of the configuration pragma Suppress_Exception_Messages
1953
1954   Extensions_Allowed_Config : Boolean;
1955   --  GNAT
1956   --  This is the flag that indicates whether extensions are allowed. It can
1957   --  be set True either by use of the -gnatX switch, or by use of the
1958   --  configuration pragma Extensions_Allowed (On). It is always set to True
1959   --  for internal GNAT units, since extensions are always permitted in such
1960   --  units.
1961
1962   External_Name_Exp_Casing_Config : External_Casing_Type;
1963   --  GNAT
1964   --  This is the value of the configuration switch that controls casing of
1965   --  external symbols for which an explicit external name is given. It can be
1966   --  set to Uppercase by the command line switch -gnatF, and further modified
1967   --  by the use of the configuration pragma External_Name_Casing in the
1968   --  gnat.adc file. This flag is used to set the initial value for
1969   --  External_Name_Exp_Casing at the start of analyzing each unit. Note
1970   --  however that the setting of this flag is ignored for internal and
1971   --  predefined units (which are always compiled with As_Is mode).
1972
1973   External_Name_Imp_Casing_Config : External_Casing_Type;
1974   --  GNAT
1975   --  This is the value of the configuration switch that controls casing of
1976   --  external symbols where the external name is implicitly given. It can be
1977   --  set to Uppercase by the command line switch -gnatF, and further modified
1978   --  by the use of the configuration pragma External_Name_Casing in the
1979   --  gnat.adc file. This flag is used to set the initial value for
1980   --  External_Name_Imp_Casing at the start of analyzing each unit. Note
1981   --  however that the setting of this flag is ignored for internal and
1982   --  predefined units (which are always compiled with Lowercase mode).
1983
1984   Fast_Math_Config : Boolean;
1985   --  GNAT
1986   --  This is the value of the configuration switch that controls Fast_Math
1987   --  mode, as set by a Fast_Math pragma in configuration pragmas. It is
1988   --  used to set the initial value of Fast_Math at the start of each new
1989   --  compilation unit.
1990
1991   Initialize_Scalars_Config : Boolean;
1992   --  GNAT
1993   --  This is the value of the configuration switch that is set by the
1994   --  pragma Initialize_Scalars when it appears in the gnat.adc file.
1995   --  This switch is not set when the pragma appears ahead of a given
1996   --  unit, so it does not affect the compilation of other units.
1997
1998   No_Exit_Message : Boolean := False;
1999   --  GNATMAKE, GPRBUILD
2000   --  Set with switch --no-exit-message. When True, if there are compilation
2001   --  failures, the builder does not issue an exit error message.
2002
2003   Optimize_Alignment_Config : Character;
2004   --  GNAT
2005   --  This is the value of the configuration switch that controls the
2006   --  alignment optimization mode, as set by an Optimize_Alignment pragma.
2007   --  It is used to set the initial value of Optimize_Alignment at the start
2008   --  of each new compilation unit, except that it is always set to 'O' (off)
2009   --  for internal units.
2010
2011   Persistent_BSS_Mode_Config : Boolean;
2012   --  GNAT
2013   --  This is the value of the configuration switch that controls whether
2014   --  potentially persistent data is to be placed in the persistent_bss
2015   --  section. It can be set True by use of the pragma Persistent_BSS.
2016   --  This flag is used to set the initial value of Persistent_BSS_Mode
2017   --  at the start of each compilation unit, except that it is always
2018   --  set False for predefined units.
2019
2020   Polling_Required_Config : Boolean;
2021   --  GNAT
2022   --  This is the value of the configuration switch that controls polling
2023   --  mode. It can be set True by the command line switch -gnatP, and then
2024   --  further modified by the use of pragma Polling in the gnat.adc file. This
2025   --  flag is used to set the initial value for Polling_Required at the start
2026   --  of analyzing each unit.
2027
2028   Prefix_Exception_Messages_Config : Boolean;
2029   --  The setting of Prefix_Exception_Messages from configuration pragmas
2030
2031   SPARK_Mode_Config : SPARK_Mode_Type := None;
2032   --  GNAT
2033   --  The setting of SPARK_Mode from configuration pragmas
2034
2035   SPARK_Mode_Pragma_Config : Node_Id := Empty;
2036   --  If a SPARK_Mode pragma appeared in the configuration pragmas (setting
2037   --  SPARK_Mode_Config appropriately), then this points to the N_Pragma node.
2038
2039   Uneval_Old_Config : Character;
2040   --  GNAT
2041   --  The setting of Uneval_Old from configuration pragmas
2042
2043   Use_VADS_Size_Config : Boolean;
2044   --  GNAT
2045   --  This is the value of the configuration switch that controls the use of
2046   --  VADS_Size instead of Size wherever the attribute Size is used. It can
2047   --  be set True by the use of the pragma Use_VADS_Size in the gnat.adc file.
2048   --  This flag is used to set the initial value for Use_VADS_Size at the
2049   --  start of analyzing each unit. Note however that the setting of this flag
2050   --  is ignored for internal and predefined units (which are always compiled
2051   --  with the standard Size semantics).
2052
2053   Warnings_As_Errors_Count_Config : Natural;
2054   --  GNAT
2055   --  Count of pattern strings stored from Warning_As_Error pragmas
2056
2057   type Config_Switches_Type is private;
2058   --  Type used to save values of the switches set from Config values
2059
2060   procedure Save_Opt_Config_Switches (Save : out Config_Switches_Type);
2061   --  This procedure saves the current values of the switches which are
2062   --  initialized from the above Config values, and then resets these switches
2063   --  according to the Config value settings.
2064
2065   procedure Set_Opt_Config_Switches
2066     (Internal_Unit : Boolean;
2067      Main_Unit     : Boolean);
2068   --  This procedure sets the switches to the appropriate initial values. The
2069   --  parameter Internal_Unit is True for an internal or predefined unit, and
2070   --  affects the way the switches are set (see above). Main_Unit is true if
2071   --  switches are being set for the main unit or for the spec of the main
2072   --  unit. This affects setting of the assert/debug pragma switches, which
2073   --  are normally set false by default for an internal unit, except when the
2074   --  internal unit is the main unit, in which case we use the command line
2075   --  settings.
2076
2077   procedure Restore_Opt_Config_Switches (Save : Config_Switches_Type);
2078   --  This procedure restores a set of switch values previously saved by a
2079   --  call to Save_Opt_Config_Switches (Save).
2080
2081   procedure Register_Opt_Config_Switches;
2082   --  This procedure is called after processing the gnat.adc file and other
2083   --  configuration pragma files to record the values of the Config switches,
2084   --  as possibly modified by the use of command line switches and pragmas
2085   --  appearing in these files.
2086
2087   ------------------------
2088   -- Other Global Flags --
2089   ------------------------
2090
2091   Expander_Active : Boolean := False;
2092   --  A flag that indicates if expansion is active (True) or deactivated
2093   --  (False). When expansion is deactivated all calls to expander routines
2094   --  have no effect. Note that the initial setting of False is merely to
2095   --  prevent saving of an undefined value for an initial call to the
2096   --  Expander_Mode_Save_And_Set procedure. For more information on the use of
2097   --  this flag, see package Expander. Indeed this flag might more logically
2098   --  be in the spec of Expander, but it is referenced by Errout, and it
2099   --  really seems wrong for Errout to depend on Expander.
2100
2101   Static_Dispatch_Tables : Boolean := True;
2102   --  This flag indicates if the backend supports generation of statically
2103   --  allocated dispatch tables. If it is True, then the front end will
2104   --  generate static aggregates for dispatch tables that contain forward
2105   --  references to addresses of subprograms not seen yet, and the back end
2106   --  must be prepared to handle this case. If it is False, then the front
2107   --  end generates assignments to initialize the dispatch table, and there
2108   --  are no such forward references. By default we build statically allocated
2109   --  dispatch tables for all library level tagged types in all platforms.This
2110   --  behavior can be disabled using switch -gnatd.t which will set this flag
2111   --  to False and revert to the previous dynamic behavior.
2112
2113   -----------------------
2114   -- Tree I/O Routines --
2115   -----------------------
2116
2117   procedure Tree_Read;
2118   --  Reads switch settings from current tree file using Tree_Read
2119
2120   procedure Tree_Write;
2121   --  Writes out switch settings to current tree file using Tree_Write
2122
2123   --------------------------
2124   -- ASIS Version Control --
2125   --------------------------
2126
2127   --  These two variables (Tree_Version_String and Tree_ASIS_Version_Number)
2128   --  are supposed to be used in the GNAT/ASIS version check performed in
2129   --  the ASIS code (this package is also a part of the ASIS implementation).
2130   --  They are set by Tree_Read procedure, so they represent the version
2131   --  number (and the version string) of the compiler which has created the
2132   --  tree, and they are supposed to be compared with the corresponding values
2133   --  from the Tree_IO and Gnatvsn packages which also are a part of ASIS
2134   --  implementation.
2135
2136   Tree_Version_String : String_Access;
2137   --  Used to store the compiler version string read from a tree file to check
2138   --  if it is from the same date as stored in the version string in Gnatvsn.
2139   --  We require that ASIS Pro can be used only with GNAT Pro, but we allow
2140   --  non-Pro ASIS and ASIS-based tools to be used with any version of the
2141   --  GNAT compiler. Therefore, we need the possibility to compare the dates
2142   --  of the corresponding source sets, using version strings that may be
2143   --  of different lengths.
2144
2145   Tree_ASIS_Version_Number : Int;
2146   --  Used to store the ASIS version number read from a tree file to check if
2147   --  it is the same as stored in the ASIS version number in Tree_IO.
2148
2149   -----------------------------------
2150   -- Modes for Formal Verification --
2151   -----------------------------------
2152
2153   GNATprove_Mode : Boolean := False;
2154   --  Specific compiling mode targeting formal verification for those parts
2155   --  of the input code that belong to the SPARK 2014 subset of Ada. Set True
2156   --  by the gnat2why executable or by use of the -gnatd.F debug switch. Note
2157   --  that this is completely separate from the SPARK restriction defined in
2158   --  GNAT to detect violations of a subset of SPARK 2005 rules.
2159
2160   ---------------------------
2161   -- Error/Warning Control --
2162   ---------------------------
2163
2164   --  The following array would more reasonably be located in Err_Vars or
2165   --  Errour, but we put them here to deal with licensing issues (we need
2166   --  this to have the GPL exception licensing, since these variables and
2167   --  subprograms are accessed from units with this licensing).
2168
2169   Warnings_As_Errors : array (1 .. 10_000) of String_Ptr;
2170   --  Table for recording Warning_As_Error pragmas as they are processed.
2171   --  It would be nicer to use Table, but there are circular elaboration
2172   --  problems if we try to do this, and an attempt to find some other
2173   --  appropriately licensed unit to declare this as a Table failed with
2174   --  various elaboration circularities. Memory is getting cheap these days!
2175
2176   ---------------
2177   -- GNAT_Mode --
2178   ---------------
2179
2180   GNAT_Mode : Boolean := False;
2181   --  GNAT
2182   --  True if compiling in GNAT system mode (-gnatg switch)
2183
2184   GNAT_Mode_Config : Boolean := False;
2185   --  GNAT
2186   --  True if -gnatg switch is present. GNAT_Mode may be temporary set to
2187   --  True during the analysis of a system unit, but GNAT_Mode_Config must
2188   --  not change once scanned and set.
2189
2190   --  Setting GNAT mode has the following effects on the language that is
2191   --  accepted. Note that several of the following have the effect of changing
2192   --  an error to a warning. But warnings are usually treated as fatal errors
2193   --  in -gnatg mode, so to actually take advantage of such a change, it is
2194   --  necessary to add an explicit pragma Warnings (Off) in the source and
2195   --  this requires clear documentation of why this is necessary.
2196
2197   --    The identifier character set is set to 'n' (7-bit ASCII)
2198
2199   --    Pragma Extend_System is ignored
2200
2201   --    Warning_Mode is set to Treat_As_Error (-gnatwe)
2202
2203   --    Standard style checks are set (See Set_GNAT_Style_Check_Options)
2204
2205   --    Standard warnings are turned on (see Set_GNAT_Mode_Warnings)
2206
2207   --    The Ada version is set to Ada 2012
2208
2209   --    Task priorities are always allowed to be in the range Any_Priority
2210
2211   --    Overflow checks are suppressed, overflow checking set to strict mode
2212
2213   --    ALI files are always generated for predefined generic packages
2214
2215   --    Obsolescent feature warnings are suppressed
2216
2217   --    Recompilation of children of GNAT, System, Ada, Interfaces is allowed
2218
2219   --    The Scalar_Storage_Order attribute applies to generic types
2220
2221   --    Categorization errors are treated as warnings rather than errors
2222
2223   --    Statements in preelaborated units give warnings rather than errors
2224
2225   --    Private objects are allowed in preelaborated units
2226
2227   --    Non-static constants in preelaborated units give warnings not errors
2228
2229   --    The warning about component size being ignored is suppressed
2230
2231   --    The warning about size clauses being ignored is suppressed
2232
2233   --    Initializing limited types gives a warning rather than an error
2234
2235   --    Copying of limited objects is allowed
2236
2237   --    Returning objects of limited types is allowed
2238
2239   --    Non-static call in preelaborated unit give a warning, not an error
2240
2241   --    Warnings on possible elaboration errors are suppressed
2242
2243   --    Warnings about packing being ignored are suppressed
2244
2245   --    Warnings in internal units are not suppressed (they normally are)
2246
2247   --    The only special comment sequence allowed is --!
2248
2249   --------------------------
2250   -- Private Declarations --
2251   --------------------------
2252
2253private
2254
2255   --  The following type is used to save and restore settings of switches in
2256   --  Opt that represent the configuration (i.e. result of config pragmas).
2257
2258   --  Note that Ada_Version_Explicit is not included, since this is a sticky
2259   --  flag that once set does not get reset, since the whole idea of this flag
2260   --  is to record the setting for the main unit.
2261
2262   type Config_Switches_Type is record
2263      Ada_Version                    : Ada_Version_Type;
2264      Ada_Version_Explicit           : Ada_Version_Type;
2265      Ada_Version_Pragma             : Node_Id;
2266      Assertions_Enabled             : Boolean;
2267      Assume_No_Invalid_Values       : Boolean;
2268      Check_Float_Overflow           : Boolean;
2269      Check_Policy_List              : Node_Id;
2270      Default_Pool                   : Node_Id;
2271      Default_SSO                    : Character;
2272      Dynamic_Elaboration_Checks     : Boolean;
2273      Exception_Locations_Suppressed : Boolean;
2274      Extensions_Allowed             : Boolean;
2275      External_Name_Exp_Casing       : External_Casing_Type;
2276      External_Name_Imp_Casing       : External_Casing_Type;
2277      Fast_Math                      : Boolean;
2278      Initialize_Scalars             : Boolean;
2279      Normalize_Scalars              : Boolean;
2280      Optimize_Alignment             : Character;
2281      Optimize_Alignment_Local       : Boolean;
2282      Persistent_BSS_Mode            : Boolean;
2283      Polling_Required               : Boolean;
2284      Prefix_Exception_Messages      : Boolean;
2285      SPARK_Mode                     : SPARK_Mode_Type;
2286      SPARK_Mode_Pragma              : Node_Id;
2287      Uneval_Old                     : Character;
2288      Use_VADS_Size                  : Boolean;
2289      Warnings_As_Errors_Count       : Natural;
2290   end record;
2291
2292   --  The following declarations are for GCC version dependent flags. We do
2293   --  not let client code in the compiler test GCC_Version directly, but
2294   --  instead use deferred constants for relevant feature tags.
2295
2296   --  Note: there currently are no such constants defined in this section,
2297   --  since the compiler front end is currently entirely independent of the
2298   --  GCC version, which is a desirable state of affairs.
2299
2300   function get_gcc_version return Int;
2301   pragma Import (C, get_gcc_version, "get_gcc_version");
2302
2303   GCC_Version : constant Nat := get_gcc_version;
2304   --  GNATMAKE
2305   --  Indicates which version of gcc is in use (3 = 3.x, 4 = 4.x). Note that
2306   --  gcc 2.8.1 (which used to be a value of 2) is no longer supported.
2307
2308end Opt;
2309