1 ------------------------------------------------------------------------------
3 -- GNAT COMPILER COMPONENTS --
9 -- Copyright (C) 1992-2013, Free Software Foundation, Inc. --
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. See the GNU General Public License --
17 -- for more details. You should have received a copy of the GNU General --
18 -- Public License distributed with GNAT; see file COPYING3. If not, go to --
19 -- http://www.gnu.org/licenses for a complete copy of the license. --
21 -- GNAT was originally developed by the GNAT team at New York University. --
22 -- Extensive contributions were provided by Ada Core Technologies Inc. --
24 ------------------------------------------------------------------------------
26 with Atree; use Atree;
27 with Back_End; use Back_End;
29 with Csets; use Csets;
30 with Debug; use Debug;
32 with Errout; use Errout;
34 with Exp_Ch6; use Exp_Ch6;
36 with Fname; use Fname;
37 with Fname.UF; use Fname.UF;
39 with Gnatvsn; use Gnatvsn;
43 with Lib.Writ; use Lib.Writ;
45 with Namet; use Namet;
48 with Osint; use Osint;
49 with Output; use Output;
52 with Repinfo; use Repinfo;
54 with Rident; use Rident;
64 with Sinfo; use Sinfo;
65 with Sinput.L; use Sinput.L;
67 with Sprint; use Sprint;
69 with Stylesw; use Stylesw;
70 with Targparm; use Targparm;
72 with Treepr; use Treepr;
74 with Types; use Types;
75 with Uintp; use Uintp;
76 with Uname; use Uname;
79 with Validsw; use Validsw;
81 with System.Assertions;
84 Main_Unit_Node : Node_Id;
85 -- Compilation unit node for main unit
87 Main_Kind : Node_Kind;
88 -- Kind of main compilation unit node
90 Back_End_Mode : Back_End.Back_End_Mode_Type;
91 -- Record back end mode
93 procedure Adjust_Global_Switches;
94 -- There are various interactions between front end switch settings,
95 -- including debug switch settings and target dependent parameters.
96 -- This procedure takes care of properly handling these interactions.
97 -- We do it after scanning out all the switches, so that we are not
98 -- depending on the order in which switches appear.
100 procedure Check_Bad_Body;
101 -- Called to check if the unit we are compiling has a bad body
103 procedure Check_Rep_Info;
104 -- Called when we are not generating code, to check if -gnatR was requested
105 -- and if so, explain that we will not be honoring the request.
107 ----------------------------
108 -- Adjust_Global_Switches --
109 ----------------------------
111 procedure Adjust_Global_Switches is
113 -- -gnatd.M enables Relaxed_RM_Semantics
115 if Debug_Flag_Dot_MM then
116 Relaxed_RM_Semantics := True;
119 -- Disable CodePeer_Mode in Check_Syntax, since we need front-end
122 if Operating_Mode = Check_Syntax then
123 CodePeer_Mode := False;
126 -- Set ASIS mode if -gnatt and -gnatc are set
128 if Operating_Mode = Check_Semantics and then Tree_Output then
131 -- Turn off inlining in ASIS mode, since ASIS cannot handle the extra
132 -- information in the trees caused by inlining being active.
134 -- More specifically, the tree seems to be malformed from the ASIS
135 -- point of view if -gnatc and -gnatn appear together???
137 Inline_Active := False;
139 -- Turn off SCIL generation and CodePeer mode in semantics mode,
140 -- since SCIL requires front-end expansion.
142 Generate_SCIL := False;
143 CodePeer_Mode := False;
146 -- SCIL mode needs to disable front-end inlining since the generated
147 -- trees (in particular order and consistency between specs compiled
148 -- as part of a main unit or as part of a with-clause) are causing
151 if Generate_SCIL then
152 Front_End_Inlining := False;
155 -- Tune settings for optimal SCIL generation in CodePeer mode
157 if CodePeer_Mode then
159 -- Turn off inlining, confuses CodePeer output and gains nothing
161 Front_End_Inlining := False;
162 Inline_Active := False;
164 -- Disable front-end optimizations, to keep the tree as close to the
165 -- source code as possible, and also to avoid inconsistencies between
166 -- trees when using different optimization switches.
168 Optimization_Level := 0;
170 -- Enable some restrictions systematically to simplify the generated
171 -- code (and ease analysis). Note that restriction checks are also
172 -- disabled in CodePeer mode, see Restrict.Check_Restriction, and
173 -- user specified Restrictions pragmas are ignored, see
174 -- Sem_Prag.Process_Restrictions_Or_Restriction_Warnings.
176 Restrict.Restrictions.Set (No_Initialize_Scalars) := True;
177 Restrict.Restrictions.Set (No_Task_Hierarchy) := True;
178 Restrict.Restrictions.Set (No_Abort_Statements) := True;
179 Restrict.Restrictions.Set (Max_Asynchronous_Select_Nesting) := True;
180 Restrict.Restrictions.Value (Max_Asynchronous_Select_Nesting) := 0;
182 -- Suppress division by zero and access checks since they are handled
183 -- implicitly by CodePeer.
185 -- Turn off dynamic elaboration checks: generates inconsistencies in
186 -- trees between specs compiled as part of a main unit or as part of
189 -- Turn off alignment checks: these cannot be proved statically by
190 -- CodePeer and generate false positives.
192 -- Enable all other language checks
194 Suppress_Options.Suppress :=
195 (Access_Check => True,
196 Alignment_Check => True,
197 Division_Check => True,
198 Elaboration_Check => True,
201 Dynamic_Elaboration_Checks := False;
203 -- Set STRICT mode for overflow checks if not set explicitly. This
204 -- prevents suppressing of overflow checks by default, in code down
207 if Suppress_Options.Overflow_Mode_General = Not_Set then
208 Suppress_Options.Overflow_Mode_General := Strict;
209 Suppress_Options.Overflow_Mode_Assertions := Strict;
212 -- CodePeer handles division and overflow checks directly, based on
213 -- the marks set by the frontend, hence no special expansion should
214 -- be performed in the frontend for division and overflow checks.
216 Backend_Divide_Checks_On_Target := True;
217 Backend_Overflow_Checks_On_Target := True;
219 -- Kill debug of generated code, since it messes up sloc values
221 Debug_Generated_Code := False;
223 -- Turn cross-referencing on in case it was disabled (e.g. by -gnatD)
224 -- Do we really need to spend time generating xref in CodePeer
225 -- mode??? Consider setting Xref_Active to False.
229 -- Polling mode forced off, since it generates confusing junk
231 Polling_Required := False;
233 -- Set operating mode to Generate_Code to benefit from full front-end
234 -- expansion (e.g. generics).
236 Operating_Mode := Generate_Code;
238 -- We need SCIL generation of course
240 Generate_SCIL := True;
242 -- Enable assertions and debug pragmas, since they give CodePeer
243 -- valuable extra information.
245 Assertions_Enabled := True;
246 Debug_Pragmas_Enabled := True;
248 -- Disable all simple value propagation. This is an optimization
249 -- which is valuable for code optimization, and also for generation
250 -- of compiler warnings, but these are being turned off by default,
251 -- and CodePeer generates better messages (referencing original
252 -- variables) this way.
254 Debug_Flag_MM := True;
256 -- Set normal RM validity checking, and checking of IN OUT parameters
257 -- (this might give CodePeer more useful checks to analyze, to be
258 -- confirmed???). All other validity checking is turned off, since
259 -- this can generate very complex trees that only confuse CodePeer
260 -- and do not bring enough useful info.
262 Reset_Validity_Check_Options;
263 Validity_Check_Default := True;
264 Validity_Check_In_Out_Params := True;
265 Validity_Check_In_Params := True;
267 -- Turn off style check options since we are not interested in any
268 -- front-end warnings when we are getting CodePeer output.
270 Reset_Style_Check_Options;
272 -- Always perform semantics and generate ali files in CodePeer mode,
273 -- so that a gnatmake -c -k will proceed further when possible.
275 Force_ALI_Tree_File := True;
276 Try_Semantics := True;
278 -- Make the Ada front-end more liberal so that the compiler will
279 -- allow illegal code that is allowed by other compilers. CodePeer
280 -- is in the business of finding problems, not enforcing rules!
281 -- This is useful when using CodePeer mode with other compilers.
283 Relaxed_RM_Semantics := True;
286 if Relaxed_RM_Semantics then
287 Overriding_Renamings := True;
290 -- Set switches for formal verification mode
292 if Debug_Flag_Dot_VV then
293 Formal_Extensions := True;
296 -- Enable Alfa_Mode when using -gnatd.F switch
298 if Debug_Flag_Dot_FF then
302 -- Alfa_Mode is also activated by default in the gnat2why executable
306 -- Set strict standard interpretation of compiler permissions
308 if Debug_Flag_Dot_DD then
309 Strict_Alfa_Mode := True;
312 -- Distinguish between the two modes of gnat2why: frame condition
313 -- generation (generation of ALI files) and translation of Why (no
314 -- ALI files generated). This is done with the switch -gnatd.G,
315 -- which activates frame condition mode. The other changes in
316 -- behavior depending on this switch are done in gnat2why directly.
318 if Debug_Flag_Dot_GG then
319 Frame_Condition_Mode := True;
321 Opt.Disable_ALI_File := True;
324 -- Turn off inlining, which would confuse formal verification output
327 Front_End_Inlining := False;
328 Inline_Active := False;
330 -- Disable front-end optimizations, to keep the tree as close to the
331 -- source code as possible, and also to avoid inconsistencies between
332 -- trees when using different optimization switches.
334 Optimization_Level := 0;
336 -- Enable some restrictions systematically to simplify the generated
337 -- code (and ease analysis). Note that restriction checks are also
338 -- disabled in Alfa mode, see Restrict.Check_Restriction, and user
339 -- specified Restrictions pragmas are ignored, see
340 -- Sem_Prag.Process_Restrictions_Or_Restriction_Warnings.
342 Restrict.Restrictions.Set (No_Initialize_Scalars) := True;
344 -- Note: at this point we used to suppress various checks, but that
345 -- is not what we want. We need the semantic processing for these
346 -- checks (which will set flags like Do_Overflow_Check, showing the
347 -- points at which potential checks are required semantically). We
348 -- don't want the expansion associated with these checks, but that
349 -- happens anyway because this expansion is simply not done in the
350 -- Alfa version of the expander.
352 -- Turn off dynamic elaboration checks: generates inconsistencies in
353 -- trees between specs compiled as part of a main unit or as part of
356 Dynamic_Elaboration_Checks := False;
358 -- Set STRICT mode for overflow checks if not set explicitly. This
359 -- prevents suppressing of overflow checks by default, in code down
362 if Suppress_Options.Overflow_Mode_General = Not_Set then
363 Suppress_Options.Overflow_Mode_General := Strict;
364 Suppress_Options.Overflow_Mode_Assertions := Strict;
367 -- Kill debug of generated code, since it messes up sloc values
369 Debug_Generated_Code := False;
371 -- Turn cross-referencing on in case it was disabled (e.g. by -gnatD)
372 -- as it is needed for computing effects of subprograms in the formal
373 -- verification backend.
377 -- Polling mode forced off, since it generates confusing junk
379 Polling_Required := False;
381 -- Set operating mode to Generate_Code, but full front-end expansion
382 -- is not desirable in Alfa mode, so a light expansion is performed
385 Operating_Mode := Generate_Code;
389 Debug_Flag_HH := True;
391 -- Disable Expressions_With_Actions nodes
393 -- The gnat2why backend does not deal with Expressions_With_Actions
394 -- in all places (in particular assertions). It is difficult to
395 -- determine in the frontend which cases are allowed, so we disable
396 -- Expressions_With_Actions entirely. Even in the cases where
397 -- gnat2why deals with Expressions_With_Actions, it is easier to
398 -- deal with the original constructs (quantified, conditional and
399 -- case expressions) instead of the rewritten ones.
401 Use_Expression_With_Actions := False;
403 -- Enable assertions and debug pragmas, since they give valuable
404 -- extra information for formal verification.
406 Assertions_Enabled := True;
407 Debug_Pragmas_Enabled := True;
409 -- Turn off style check options since we are not interested in any
410 -- front-end warnings when we are getting Alfa output.
412 Reset_Style_Check_Options;
414 -- Suppress compiler warnings, since what we are interested in here
415 -- is what formal verification can find out.
417 Warning_Mode := Suppress;
419 -- Suppress the generation of name tables for enumerations, which are
420 -- not needed for formal verification, and fall outside the Alfa
421 -- subset (use of pointers).
423 Global_Discard_Names := True;
425 -- Suppress the expansion of tagged types and dispatching calls,
426 -- which lead to the generation of non-Alfa code (use of pointers),
427 -- which is more complex to formally verify than the original source.
429 Tagged_Type_Expansion := False;
433 -- Set Configurable_Run_Time mode if system.ads flag set
435 if Targparm.Configurable_Run_Time_On_Target or Debug_Flag_YY then
436 Configurable_Run_Time_Mode := True;
439 -- Set -gnatR3m mode if debug flag A set
441 if Debug_Flag_AA then
442 Back_Annotate_Rep_Info := True;
443 List_Representation_Info := 1;
444 List_Representation_Info_Mechanisms := True;
447 -- Force Target_Strict_Alignment true if debug flag -gnatd.a is set
449 if Debug_Flag_Dot_A then
450 Ttypes.Target_Strict_Alignment := True;
453 -- Increase size of allocated entities if debug flag -gnatd.N is set
455 if Debug_Flag_Dot_NN then
456 Atree.Num_Extension_Nodes := Atree.Num_Extension_Nodes + 1;
459 -- Disable static allocation of dispatch tables if -gnatd.t or if layout
460 -- is enabled. The front end's layout phase currently treats types that
461 -- have discriminant-dependent arrays as not being static even when a
462 -- discriminant constraint on the type is static, and this leads to
463 -- problems with subtypes of type Ada.Tags.Dispatch_Table_Wrapper. ???
465 if Debug_Flag_Dot_T or else Frontend_Layout_On_Target then
466 Static_Dispatch_Tables := False;
469 -- Flip endian mode if -gnatd8 set
472 Ttypes.Bytes_Big_Endian := not Ttypes.Bytes_Big_Endian;
475 -- Deal with forcing OpenVMS switches True if debug flag M is set, but
476 -- record the setting of Targparm.Open_VMS_On_Target in True_VMS_Target
477 -- before doing this, so we know if we are in real OpenVMS or not!
479 Opt.True_VMS_Target := Targparm.OpenVMS_On_Target;
482 Targparm.OpenVMS_On_Target := True;
483 Hostparm.OpenVMS := True;
486 -- Activate front end layout if debug flag -gnatdF is set
488 if Debug_Flag_FF then
489 Targparm.Frontend_Layout_On_Target := True;
492 -- Set and check exception mechanism
494 if Targparm.ZCX_By_Default_On_Target then
495 Exception_Mechanism := Back_End_Exceptions;
498 -- Set proper status for overflow check mechanism
500 -- If already set (by -gnato or above in Alfa or CodePeer mode) then we
501 -- have nothing to do.
503 if Opt.Suppress_Options.Overflow_Mode_General /= Not_Set then
506 -- Otherwise set overflow mode defaults
509 -- Otherwise set overflow checks off by default
511 Suppress_Options.Suppress (Overflow_Check) := True;
513 -- Set appropriate default overflow handling mode. Note: at present
514 -- we set STRICT in all three of the following cases. They are
515 -- separated because in the future we may make different choices.
517 -- By default set STRICT mode if -gnatg in effect
520 Suppress_Options.Overflow_Mode_General := Strict;
521 Suppress_Options.Overflow_Mode_Assertions := Strict;
523 -- If we have backend divide and overflow checks, then by default
524 -- overflow checks are STRICT. Historically this code used to also
525 -- activate overflow checks, although no target currently has these
526 -- flags set, so this was dead code anyway.
528 elsif Targparm.Backend_Divide_Checks_On_Target
530 Targparm.Backend_Overflow_Checks_On_Target
532 Suppress_Options.Overflow_Mode_General := Strict;
533 Suppress_Options.Overflow_Mode_Assertions := Strict;
535 -- Otherwise for now, default is STRICT mode. This may change in the
536 -- future, but for now this is the compatible behavior with previous
540 Suppress_Options.Overflow_Mode_General := Strict;
541 Suppress_Options.Overflow_Mode_Assertions := Strict;
545 -- Set default for atomic synchronization. As this synchronization
546 -- between atomic accesses can be expensive, and not typically needed
547 -- on some targets, an optional target parameter can turn the option
548 -- off. Note Atomic Synchronization is implemented as check.
550 Suppress_Options.Suppress (Atomic_Synchronization) :=
551 not Atomic_Sync_Default_On_Target;
553 -- Set switch indicating if we can use N_Expression_With_Actions
555 -- Debug flag -gnatd.X decisively sets usage on
557 if Debug_Flag_Dot_XX then
558 Use_Expression_With_Actions := True;
560 -- Debug flag -gnatd.Y decisively sets usage off
562 elsif Debug_Flag_Dot_YY then
563 Use_Expression_With_Actions := False;
565 -- Otherwise this feature is implemented, so we allow its use
568 Use_Expression_With_Actions := True;
571 -- Set switch indicating if back end can handle limited types, and
572 -- guarantee that no incorrect copies are made (e.g. in the context
573 -- of an if or case expression).
575 -- Debug flag -gnatd.L decisively sets usage on
577 if Debug_Flag_Dot_LL then
578 Back_End_Handles_Limited_Types := True;
580 -- If no debug flag, usage off for AAMP, VM, SCIL cases
583 or else VM_Target /= No_VM
584 or else Generate_SCIL
586 Back_End_Handles_Limited_Types := False;
588 -- Otherwise normal gcc back end, for now still turn flag off by
589 -- default, since there are unresolved problems in the front end.
592 Back_End_Handles_Limited_Types := False;
595 -- If the inlining level has not been set by the user, compute it from
596 -- the optimization level: 1 at -O1/-O2 (and -Os), 2 at -O3 and above.
598 if Inline_Level = 0 then
599 if Optimization_Level < 3 then
606 -- Finally capture adjusted value of Suppress_Options as the initial
607 -- value for Scope_Suppress, which will be modified as we move from
608 -- scope to scope (by Suppress/Unsuppress/Overflow_Checks pragmas).
610 Sem.Scope_Suppress := Opt.Suppress_Options;
611 end Adjust_Global_Switches;
617 procedure Check_Bad_Body is
618 Sname : Unit_Name_Type;
619 Src_Ind : Source_File_Index;
620 Fname : File_Name_Type;
622 procedure Bad_Body_Error (Msg : String);
623 -- Issue message for bad body found
629 procedure Bad_Body_Error (Msg : String) is
631 Error_Msg_N (Msg, Main_Unit_Node);
632 Error_Msg_File_1 := Fname;
633 Error_Msg_N ("remove incorrect body in file{!", Main_Unit_Node);
636 -- Start of processing for Check_Bad_Body
639 -- Nothing to do if we are only checking syntax, because we don't know
640 -- enough to know if we require or forbid a body in this case.
642 if Operating_Mode = Check_Syntax then
646 -- Check for body not allowed
648 if (Main_Kind = N_Package_Declaration
649 and then not Body_Required (Main_Unit_Node))
650 or else (Main_Kind = N_Generic_Package_Declaration
651 and then not Body_Required (Main_Unit_Node))
652 or else Main_Kind = N_Package_Renaming_Declaration
653 or else Main_Kind = N_Subprogram_Renaming_Declaration
654 or else Nkind (Original_Node (Unit (Main_Unit_Node)))
655 in N_Generic_Instantiation
657 Sname := Unit_Name (Main_Unit);
659 -- If we do not already have a body name, then get the body name
660 -- (but how can we have a body name here???)
662 if not Is_Body_Name (Sname) then
663 Sname := Get_Body_Name (Sname);
666 Fname := Get_File_Name (Sname, Subunit => False);
667 Src_Ind := Load_Source_File (Fname);
669 -- Case where body is present and it is not a subunit. Exclude the
670 -- subunit case, because it has nothing to do with the package we are
671 -- compiling. It is illegal for a child unit and a subunit with the
672 -- same expanded name (RM 10.2(9)) to appear together in a partition,
673 -- but there is nothing to stop a compilation environment from having
674 -- both, and the test here simply allows that. If there is an attempt
675 -- to include both in a partition, this is diagnosed at bind time. In
676 -- Ada 83 mode this is not a warning case.
678 -- Note: if weird file names are being used, we can have a situation
679 -- where the file name that supposedly contains body in fact contains
680 -- a spec, or we can't tell what it contains. Skip the error message
683 -- Also ignore body that is nothing but pragma No_Body; (that's the
684 -- whole point of this pragma, to be used this way and to cause the
685 -- body file to be ignored in this context).
687 if Src_Ind /= No_Source_File
688 and then Get_Expected_Unit_Type (Fname) = Expect_Body
689 and then not Source_File_Is_Subunit (Src_Ind)
690 and then not Source_File_Is_No_Body (Src_Ind)
692 Errout.Finalize (Last_Call => False);
694 Error_Msg_Unit_1 := Sname;
696 -- Ada 83 case of a package body being ignored. This is not an
697 -- error as far as the Ada 83 RM is concerned, but it is almost
698 -- certainly not what is wanted so output a warning. Give this
699 -- message only if there were no errors, since otherwise it may
700 -- be incorrect (we may have misinterpreted a junk spec as not
701 -- needing a body when it really does).
703 if Main_Kind = N_Package_Declaration
704 and then Ada_Version = Ada_83
705 and then Operating_Mode = Generate_Code
706 and then Distribution_Stub_Mode /= Generate_Caller_Stub_Body
707 and then not Compilation_Errors
710 ("package $$ does not require a body??", Main_Unit_Node);
711 Error_Msg_File_1 := Fname;
712 Error_Msg_N ("body in file{ will be ignored??", Main_Unit_Node);
714 -- Ada 95 cases of a body file present when no body is
715 -- permitted. This we consider to be an error.
718 -- For generic instantiations, we never allow a body
720 if Nkind (Original_Node (Unit (Main_Unit_Node)))
721 in N_Generic_Instantiation
724 ("generic instantiation for $$ does not allow a body");
726 -- A library unit that is a renaming never allows a body
728 elsif Main_Kind in N_Renaming_Declaration then
730 ("renaming declaration for $$ does not allow a body!");
732 -- Remaining cases are packages and generic packages. Here
733 -- we only do the test if there are no previous errors,
734 -- because if there are errors, they may lead us to
735 -- incorrectly believe that a package does not allow a body
736 -- when in fact it does.
738 elsif not Compilation_Errors then
739 if Main_Kind = N_Package_Declaration then
741 ("package $$ does not allow a body!");
743 elsif Main_Kind = N_Generic_Package_Declaration then
745 ("generic package $$ does not allow a body!");
758 procedure Check_Rep_Info is
760 if List_Representation_Info /= 0
761 or else List_Representation_Info_Mechanisms
766 ("cannot generate representation information, no code generated");
773 -- Start of processing for Gnat1drv
776 -- This inner block is set up to catch assertion errors and constraint
777 -- errors. Since the code for handling these errors can cause another
778 -- exception to be raised (namely Unrecoverable_Error), we need two
779 -- nested blocks, so that the outer one handles unrecoverable error.
782 -- Initialize all packages. For the most part, these initialization
783 -- calls can be made in any order. Exceptions are as follows:
785 -- Lib.Initialize need to be called before Scan_Compiler_Arguments,
786 -- because it initializes a table filled by Scan_Compiler_Arguments.
792 Scan_Compiler_Arguments;
793 Osint.Add_Default_Search_Dirs;
813 Sem_Type.Init_Interp_Tables;
815 -- Acquire target parameters from system.ads (source of package System)
820 S : Source_File_Index;
824 Name_Buffer (1 .. 10) := "system.ads";
827 S := Load_Source_File (N);
829 if S = No_Source_File then
831 ("fatal error, run-time library not installed correctly");
832 Write_Line ("cannot locate file system.ads");
833 raise Unrecoverable_Error;
835 -- Remember source index of system.ads (which was read successfully)
838 System_Source_File_Index := S;
841 Targparm.Get_Target_Parameters
842 (System_Text => Source_Text (S),
843 Source_First => Source_First (S),
844 Source_Last => Source_Last (S));
846 -- Acquire configuration pragma information from Targparm
848 Restrict.Restrictions := Targparm.Restrictions_On_Target;
851 Adjust_Global_Switches;
853 -- Output copyright notice if full list mode unless we have a list
854 -- file, in which case we defer this so that it is output in the file
856 if (Verbose_Mode or else (Full_List and then Full_List_File_Name = null))
857 and then not Debug_Flag_7
861 Write_Str (Gnat_Version_String);
863 Write_Str ("Copyright 1992-" & Current_Year
864 & ", Free Software Foundation, Inc.");
868 -- Check we do not have more than one source file, this happens only in
869 -- the case where the driver is called directly, it cannot happen when
870 -- gnat1 is invoked from gcc in the normal case.
872 if Osint.Number_Of_Files /= 1 then
875 Osint.Fail ("you must provide one source file");
877 elsif Usage_Requested then
881 Original_Operating_Mode := Operating_Mode;
884 -- Exit with errors if the main source could not be parsed. Also, when
885 -- -gnatd.H is present, the source file is not set.
887 if Sinput.Main_Source_File = No_Source_File then
889 -- Handle -gnatd.H debug mode
891 if Debug_Flag_Dot_HH then
893 -- For -gnatd.H, lock all the tables to keep the convention that
894 -- the backend needs to unlock the tables it wants to touch.
907 -- And all we need to do is to call the back end
909 Back_End.Call_Back_End (Back_End.Generate_Object);
912 Errout.Finalize (Last_Call => True);
913 Errout.Output_Messages;
914 Exit_Program (E_Errors);
917 Main_Unit_Node := Cunit (Main_Unit);
918 Main_Kind := Nkind (Unit (Main_Unit_Node));
921 -- In CodePeer mode we always delete old SCIL files before regenerating
922 -- new ones, in case of e.g. errors, and also to remove obsolete scilx
923 -- files generated by CodePeer itself.
925 if CodePeer_Mode then
926 Comperr.Delete_SCIL_Files;
929 -- Exit if compilation errors detected
931 Errout.Finalize (Last_Call => False);
933 if Compilation_Errors then
935 Sem_Ch13.Validate_Unchecked_Conversions;
936 Sem_Ch13.Validate_Address_Clauses;
937 Sem_Ch13.Validate_Independence;
938 Errout.Output_Messages;
941 -- Generate ALI file if specially requested
943 if Opt.Force_ALI_Tree_File then
944 Write_ALI (Object => False);
948 Errout.Finalize (Last_Call => True);
949 Exit_Program (E_Errors);
952 -- Set Generate_Code on main unit and its spec. We do this even if are
953 -- not generating code, since Lib-Writ uses this to determine which
954 -- units get written in the ali file.
956 Set_Generate_Code (Main_Unit);
958 -- If we have a corresponding spec, and it comes from source or it is
959 -- not a generated spec for a child subprogram body, then we need object
960 -- code for the spec unit as well.
962 if Nkind (Unit (Main_Unit_Node)) in N_Unit_Body
963 and then not Acts_As_Spec (Main_Unit_Node)
965 if Nkind (Unit (Main_Unit_Node)) = N_Subprogram_Body
966 and then not Comes_From_Source (Library_Unit (Main_Unit_Node))
971 (Get_Cunit_Unit_Number (Library_Unit (Main_Unit_Node)));
975 -- Case of no code required to be generated, exit indicating no error
977 if Original_Operating_Mode = Check_Syntax then
979 Errout.Finalize (Last_Call => True);
980 Errout.Output_Messages;
985 -- Use a goto instead of calling Exit_Program so that finalization
990 elsif Original_Operating_Mode = Check_Semantics then
991 Back_End_Mode := Declarations_Only;
993 -- All remaining cases are cases in which the user requested that code
994 -- be generated (i.e. no -gnatc or -gnats switch was used). Check if we
995 -- can in fact satisfy this request.
997 -- Cannot generate code if someone has turned off code generation for
998 -- any reason at all. We will try to figure out a reason below.
1000 elsif Operating_Mode /= Generate_Code then
1001 Back_End_Mode := Skip;
1003 -- We can generate code for a subprogram body unless there were missing
1004 -- subunits. Note that we always generate code for all generic units (a
1005 -- change from some previous versions of GNAT).
1007 elsif Main_Kind = N_Subprogram_Body and then not Subunits_Missing then
1008 Back_End_Mode := Generate_Object;
1010 -- We can generate code for a package body unless there are subunits
1011 -- missing (note that we always generate code for generic units, which
1012 -- is a change from some earlier versions of GNAT).
1014 elsif Main_Kind = N_Package_Body and then not Subunits_Missing then
1015 Back_End_Mode := Generate_Object;
1017 -- We can generate code for a package declaration or a subprogram
1018 -- declaration only if it does not required a body.
1020 elsif Nkind_In (Main_Kind,
1021 N_Package_Declaration,
1022 N_Subprogram_Declaration)
1024 (not Body_Required (Main_Unit_Node)
1026 Distribution_Stub_Mode = Generate_Caller_Stub_Body)
1028 Back_End_Mode := Generate_Object;
1030 -- We can generate code for a generic package declaration of a generic
1031 -- subprogram declaration only if does not require a body.
1033 elsif Nkind_In (Main_Kind, N_Generic_Package_Declaration,
1034 N_Generic_Subprogram_Declaration)
1035 and then not Body_Required (Main_Unit_Node)
1037 Back_End_Mode := Generate_Object;
1039 -- Compilation units that are renamings do not require bodies, so we can
1040 -- generate code for them.
1042 elsif Nkind_In (Main_Kind, N_Package_Renaming_Declaration,
1043 N_Subprogram_Renaming_Declaration)
1045 Back_End_Mode := Generate_Object;
1047 -- Compilation units that are generic renamings do not require bodies
1048 -- so we can generate code for them.
1050 elsif Main_Kind in N_Generic_Renaming_Declaration then
1051 Back_End_Mode := Generate_Object;
1053 -- It is not an error to analyze in CodePeer mode a spec which requires
1054 -- a body, in order to generate SCIL for this spec.
1056 elsif CodePeer_Mode then
1057 Back_End_Mode := Generate_Object;
1059 -- It is not an error to analyze in Alfa mode a spec which requires a
1060 -- body, when the body is not available. During frame condition
1061 -- generation, the corresponding ALI file is generated. During
1062 -- translation to Why, Why code is generated for the spec.
1064 elsif Alfa_Mode then
1065 if Frame_Condition_Mode then
1066 Back_End_Mode := Declarations_Only;
1068 Back_End_Mode := Generate_Object;
1071 -- In all other cases (specs which have bodies, generics, and bodies
1072 -- where subunits are missing), we cannot generate code and we generate
1073 -- a warning message. Note that generic instantiations are gone at this
1074 -- stage since they have been replaced by their instances.
1077 Back_End_Mode := Skip;
1080 -- At this stage Back_End_Mode is set to indicate if the backend should
1081 -- be called to generate code. If it is Skip, then code generation has
1082 -- been turned off, even though code was requested by the original
1083 -- command. This is not an error from the user point of view, but it is
1084 -- an error from the point of view of the gcc driver, so we must exit
1085 -- with an error status.
1087 -- We generate an informative message (from the gcc point of view, it
1088 -- is an error message, but from the users point of view this is not an
1089 -- error, just a consequence of compiling something that cannot
1092 if Back_End_Mode = Skip then
1094 Write_Str ("cannot generate code for ");
1095 Write_Str ("file ");
1096 Write_Name (Unit_File_Name (Main_Unit));
1098 if Subunits_Missing then
1099 Write_Str (" (missing subunits)");
1102 -- Force generation of ALI file, for backward compatibility
1104 Opt.Force_ALI_Tree_File := True;
1106 elsif Main_Kind = N_Subunit then
1107 Write_Str (" (subunit)");
1110 -- Force generation of ALI file, for backward compatibility
1112 Opt.Force_ALI_Tree_File := True;
1114 elsif Main_Kind = N_Subprogram_Declaration then
1115 Write_Str (" (subprogram spec)");
1118 -- Generic package body in GNAT implementation mode
1120 elsif Main_Kind = N_Package_Body and then GNAT_Mode then
1121 Write_Str (" (predefined generic)");
1124 -- Force generation of ALI file, for backward compatibility
1126 Opt.Force_ALI_Tree_File := True;
1128 -- Only other case is a package spec
1131 Write_Str (" (package spec)");
1135 Set_Standard_Output;
1137 Sem_Ch13.Validate_Unchecked_Conversions;
1138 Sem_Ch13.Validate_Address_Clauses;
1139 Sem_Ch13.Validate_Independence;
1140 Errout.Finalize (Last_Call => True);
1141 Errout.Output_Messages;
1145 -- Generate ALI file if specially requested, or for missing subunits,
1146 -- subunits or predefined generic.
1148 if Opt.Force_ALI_Tree_File then
1149 Write_ALI (Object => False);
1155 -- Exit program with error indication, to kill object file
1157 Exit_Program (E_No_Code);
1160 -- In -gnatc mode, we only do annotation if -gnatt or -gnatR is also set
1161 -- as indicated by Back_Annotate_Rep_Info being set to True.
1163 -- We don't call for annotations on a subunit, because to process those
1164 -- the back-end requires that the parent(s) be properly compiled.
1166 -- Annotation is suppressed for targets where front-end layout is
1167 -- enabled, because the front end determines representations.
1169 -- Annotation is also suppressed in the case of compiling for a VM,
1170 -- since representations are largely symbolic there.
1172 if Back_End_Mode = Declarations_Only
1173 and then (not (Back_Annotate_Rep_Info or Generate_SCIL)
1174 or else Main_Kind = N_Subunit
1175 or else Targparm.Frontend_Layout_On_Target
1176 or else Targparm.VM_Target /= No_VM)
1178 Sem_Ch13.Validate_Unchecked_Conversions;
1179 Sem_Ch13.Validate_Address_Clauses;
1180 Sem_Ch13.Validate_Independence;
1181 Errout.Finalize (Last_Call => True);
1182 Errout.Output_Messages;
1183 Write_ALI (Object => False);
1191 -- Ensure that we properly register a dependency on system.ads, since
1192 -- even if we do not semantically depend on this, Targparm has read
1193 -- system parameters from the system.ads file.
1195 Lib.Writ.Ensure_System_Dependency;
1197 -- Add dependencies, if any, on preprocessing data file and on
1198 -- preprocessing definition file(s).
1200 Prepcomp.Add_Dependencies;
1202 -- Back end needs to explicitly unlock tables it needs to touch
1215 -- Here we call the back end to generate the output code
1217 Generating_Code := True;
1218 Back_End.Call_Back_End (Back_End_Mode);
1220 -- Once the backend is complete, we unlock the names table. This call
1221 -- allows a few extra entries, needed for example for the file name for
1222 -- the library file output.
1226 -- Generate the call-graph output of dispatching calls
1228 Exp_CG.Generate_CG_Output;
1230 -- Validate unchecked conversions (using the values for size and
1231 -- alignment annotated by the backend where possible).
1233 Sem_Ch13.Validate_Unchecked_Conversions;
1235 -- Validate address clauses (again using alignment values annotated
1236 -- by the backend where possible).
1238 Sem_Ch13.Validate_Address_Clauses;
1240 -- Validate independence pragmas (again using values annotated by
1241 -- the back end for component layout etc.)
1243 Sem_Ch13.Validate_Independence;
1245 -- Now we complete output of errors, rep info and the tree info. These
1246 -- are delayed till now, since it is perfectly possible for gigi to
1247 -- generate errors, modify the tree (in particular by setting flags
1248 -- indicating that elaboration is required, and also to back annotate
1249 -- representation information for List_Rep_Info.
1251 Errout.Finalize (Last_Call => True);
1252 Errout.Output_Messages;
1256 -- Only write the library if the backend did not generate any error
1257 -- messages. Otherwise signal errors to the driver program so that
1258 -- there will be no attempt to generate an object file.
1260 if Compilation_Errors then
1262 Exit_Program (E_Errors);
1265 Write_ALI (Object => (Back_End_Mode = Generate_Object));
1267 if not Compilation_Errors then
1269 -- In case of ada backends, we need to make sure that the generated
1270 -- object file has a timestamp greater than the ALI file. We do this
1271 -- to make gnatmake happy when checking the ALI and obj timestamps,
1272 -- where it expects the object file being written after the ali file.
1274 -- Gnatmake's assumption is true for gcc platforms where the gcc
1275 -- wrapper needs to call the assembler after calling gnat1, but is
1276 -- not true for ada backends, where the object files are created
1277 -- directly by gnat1 (so are created before the ali file).
1279 Back_End.Gen_Or_Update_Object_File;
1282 -- Generate ASIS tree after writing the ALI file, since in ASIS mode,
1283 -- Write_ALI may in fact result in further tree decoration from the
1284 -- original tree file. Note that we dump the tree just before generating
1285 -- it, so that the dump will exactly reflect what is written out.
1290 -- Finalize name table and we are all done
1295 -- Handle fatal internal compiler errors
1297 when Rtsfind.RE_Not_Available =>
1298 Comperr.Compiler_Abort ("RE_Not_Available");
1300 when System.Assertions.Assert_Failure =>
1301 Comperr.Compiler_Abort ("Assert_Failure");
1303 when Constraint_Error =>
1304 Comperr.Compiler_Abort ("Constraint_Error");
1306 when Program_Error =>
1307 Comperr.Compiler_Abort ("Program_Error");
1309 when Storage_Error =>
1311 -- Assume this is a bug. If it is real, the message will in any case
1312 -- say Storage_Error, giving a strong hint!
1314 Comperr.Compiler_Abort ("Storage_Error");
1320 -- The outer exception handles an unrecoverable error
1323 when Unrecoverable_Error =>
1324 Errout.Finalize (Last_Call => True);
1325 Errout.Output_Messages;
1328 Write_Str ("compilation abandoned");
1331 Set_Standard_Output;
1334 Exit_Program (E_Errors);