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 if Debug_Flag_Dot_FF then
299 -- Set strict standard interpretation of compiler permissions
301 if Debug_Flag_Dot_DD then
302 Strict_Alfa_Mode := True;
305 -- Turn off inlining, which would confuse formal verification output
308 Front_End_Inlining := False;
309 Inline_Active := False;
311 -- Disable front-end optimizations, to keep the tree as close to the
312 -- source code as possible, and also to avoid inconsistencies between
313 -- trees when using different optimization switches.
315 Optimization_Level := 0;
317 -- Enable some restrictions systematically to simplify the generated
318 -- code (and ease analysis). Note that restriction checks are also
319 -- disabled in Alfa mode, see Restrict.Check_Restriction, and user
320 -- specified Restrictions pragmas are ignored, see
321 -- Sem_Prag.Process_Restrictions_Or_Restriction_Warnings.
323 Restrict.Restrictions.Set (No_Initialize_Scalars) := True;
325 -- Note: at this point we used to suppress various checks, but that
326 -- is not what we want. We need the semantic processing for these
327 -- checks (which will set flags like Do_Overflow_Check, showing the
328 -- points at which potential checks are required semantically). We
329 -- don't want the expansion associated with these checks, but that
330 -- happens anyway because this expansion is simply not done in the
331 -- Alfa version of the expander.
333 -- Turn off dynamic elaboration checks: generates inconsistencies in
334 -- trees between specs compiled as part of a main unit or as part of
337 Dynamic_Elaboration_Checks := False;
339 -- Set STRICT mode for overflow checks if not set explicitly. This
340 -- prevents suppressing of overflow checks by default, in code down
343 if Suppress_Options.Overflow_Mode_General = Not_Set then
344 Suppress_Options.Overflow_Mode_General := Strict;
345 Suppress_Options.Overflow_Mode_Assertions := Strict;
348 -- Kill debug of generated code, since it messes up sloc values
350 Debug_Generated_Code := False;
352 -- Turn cross-referencing on in case it was disabled (e.g. by -gnatD)
353 -- as it is needed for computing effects of subprograms in the formal
354 -- verification backend.
358 -- Polling mode forced off, since it generates confusing junk
360 Polling_Required := False;
362 -- Set operating mode to Generate_Code, but full front-end expansion
363 -- is not desirable in Alfa mode, so a light expansion is performed
366 Operating_Mode := Generate_Code;
370 Debug_Flag_HH := True;
372 -- Disable Expressions_With_Actions nodes
374 -- The gnat2why backend does not deal with Expressions_With_Actions
375 -- in all places (in particular assertions). It is difficult to
376 -- determine in the frontend which cases are allowed, so we disable
377 -- Expressions_With_Actions entirely. Even in the cases where
378 -- gnat2why deals with Expressions_With_Actions, it is easier to
379 -- deal with the original constructs (quantified, conditional and
380 -- case expressions) instead of the rewritten ones.
382 Use_Expression_With_Actions := False;
384 -- Enable assertions and debug pragmas, since they give valuable
385 -- extra information for formal verification.
387 Assertions_Enabled := True;
388 Debug_Pragmas_Enabled := True;
390 -- Turn off style check options since we are not interested in any
391 -- front-end warnings when we are getting Alfa output.
393 Reset_Style_Check_Options;
395 -- Suppress compiler warnings, since what we are interested in here
396 -- is what formal verification can find out.
398 Warning_Mode := Suppress;
400 -- Suppress the generation of name tables for enumerations, which are
401 -- not needed for formal verification, and fall outside the Alfa
402 -- subset (use of pointers).
404 Global_Discard_Names := True;
406 -- Suppress the expansion of tagged types and dispatching calls,
407 -- which lead to the generation of non-Alfa code (use of pointers),
408 -- which is more complex to formally verify than the original source.
410 Tagged_Type_Expansion := False;
412 -- Distinguish between the two modes of gnat2why: frame condition
413 -- generation (generation of ALI files) and translation of Why (no
414 -- ALI files generated). This is done with the switch -gnatd.G,
415 -- which activates frame condition mode. The other changes in
416 -- behavior depending on this switch are done in gnat2why directly.
418 if not Debug_Flag_Dot_GG then
419 Opt.Disable_ALI_File := True;
424 -- Set Configurable_Run_Time mode if system.ads flag set
426 if Targparm.Configurable_Run_Time_On_Target or Debug_Flag_YY then
427 Configurable_Run_Time_Mode := True;
430 -- Set -gnatR3m mode if debug flag A set
432 if Debug_Flag_AA then
433 Back_Annotate_Rep_Info := True;
434 List_Representation_Info := 1;
435 List_Representation_Info_Mechanisms := True;
438 -- Force Target_Strict_Alignment true if debug flag -gnatd.a is set
440 if Debug_Flag_Dot_A then
441 Ttypes.Target_Strict_Alignment := True;
444 -- Increase size of allocated entities if debug flag -gnatd.N is set
446 if Debug_Flag_Dot_NN then
447 Atree.Num_Extension_Nodes := Atree.Num_Extension_Nodes + 1;
450 -- Disable static allocation of dispatch tables if -gnatd.t or if layout
451 -- is enabled. The front end's layout phase currently treats types that
452 -- have discriminant-dependent arrays as not being static even when a
453 -- discriminant constraint on the type is static, and this leads to
454 -- problems with subtypes of type Ada.Tags.Dispatch_Table_Wrapper. ???
456 if Debug_Flag_Dot_T or else Frontend_Layout_On_Target then
457 Static_Dispatch_Tables := False;
460 -- Flip endian mode if -gnatd8 set
463 Ttypes.Bytes_Big_Endian := not Ttypes.Bytes_Big_Endian;
466 -- Deal with forcing OpenVMS switches True if debug flag M is set, but
467 -- record the setting of Targparm.Open_VMS_On_Target in True_VMS_Target
468 -- before doing this, so we know if we are in real OpenVMS or not!
470 Opt.True_VMS_Target := Targparm.OpenVMS_On_Target;
473 Targparm.OpenVMS_On_Target := True;
474 Hostparm.OpenVMS := True;
477 -- Activate front end layout if debug flag -gnatdF is set
479 if Debug_Flag_FF then
480 Targparm.Frontend_Layout_On_Target := True;
483 -- Set and check exception mechanism
485 if Targparm.ZCX_By_Default_On_Target then
486 Exception_Mechanism := Back_End_Exceptions;
489 -- Set proper status for overflow check mechanism
491 -- If already set (by -gnato or above in Alfa or CodePeer mode) then we
492 -- have nothing to do.
494 if Opt.Suppress_Options.Overflow_Mode_General /= Not_Set then
497 -- Otherwise set overflow mode defaults
500 -- Otherwise set overflow checks off by default
502 Suppress_Options.Suppress (Overflow_Check) := True;
504 -- Set appropriate default overflow handling mode. Note: at present
505 -- we set STRICT in all three of the following cases. They are
506 -- separated because in the future we may make different choices.
508 -- By default set STRICT mode if -gnatg in effect
511 Suppress_Options.Overflow_Mode_General := Strict;
512 Suppress_Options.Overflow_Mode_Assertions := Strict;
514 -- If we have backend divide and overflow checks, then by default
515 -- overflow checks are STRICT. Historically this code used to also
516 -- activate overflow checks, although no target currently has these
517 -- flags set, so this was dead code anyway.
519 elsif Targparm.Backend_Divide_Checks_On_Target
521 Targparm.Backend_Overflow_Checks_On_Target
523 Suppress_Options.Overflow_Mode_General := Strict;
524 Suppress_Options.Overflow_Mode_Assertions := Strict;
526 -- Otherwise for now, default is STRICT mode. This may change in the
527 -- future, but for now this is the compatible behavior with previous
531 Suppress_Options.Overflow_Mode_General := Strict;
532 Suppress_Options.Overflow_Mode_Assertions := Strict;
536 -- Set default for atomic synchronization. As this synchronization
537 -- between atomic accesses can be expensive, and not typically needed
538 -- on some targets, an optional target parameter can turn the option
539 -- off. Note Atomic Synchronization is implemented as check.
541 Suppress_Options.Suppress (Atomic_Synchronization) :=
542 not Atomic_Sync_Default_On_Target;
544 -- Set switch indicating if we can use N_Expression_With_Actions
546 -- Debug flag -gnatd.X decisively sets usage on
548 if Debug_Flag_Dot_XX then
549 Use_Expression_With_Actions := True;
551 -- Debug flag -gnatd.Y decisively sets usage off
553 elsif Debug_Flag_Dot_YY then
554 Use_Expression_With_Actions := False;
556 -- Otherwise this feature is implemented, so we allow its use
559 Use_Expression_With_Actions := True;
562 -- Set switch indicating if back end can handle limited types, and
563 -- guarantee that no incorrect copies are made (e.g. in the context
564 -- of an if or case expression).
566 -- Debug flag -gnatd.L decisively sets usage on
568 if Debug_Flag_Dot_LL then
569 Back_End_Handles_Limited_Types := True;
571 -- If no debug flag, usage off for AAMP, VM, SCIL cases
574 or else VM_Target /= No_VM
575 or else Generate_SCIL
577 Back_End_Handles_Limited_Types := False;
579 -- Otherwise normal gcc back end, for now still turn flag off by
580 -- default, since there are unresolved problems in the front end.
583 Back_End_Handles_Limited_Types := False;
586 -- If the inlining level has not been set by the user, compute it from
587 -- the optimization level: 1 at -O1/-O2 (and -Os), 2 at -O3 and above.
589 if Inline_Level = 0 then
590 if Optimization_Level < 3 then
597 -- Finally capture adjusted value of Suppress_Options as the initial
598 -- value for Scope_Suppress, which will be modified as we move from
599 -- scope to scope (by Suppress/Unsuppress/Overflow_Checks pragmas).
601 Sem.Scope_Suppress := Opt.Suppress_Options;
602 end Adjust_Global_Switches;
608 procedure Check_Bad_Body is
609 Sname : Unit_Name_Type;
610 Src_Ind : Source_File_Index;
611 Fname : File_Name_Type;
613 procedure Bad_Body_Error (Msg : String);
614 -- Issue message for bad body found
620 procedure Bad_Body_Error (Msg : String) is
622 Error_Msg_N (Msg, Main_Unit_Node);
623 Error_Msg_File_1 := Fname;
624 Error_Msg_N ("remove incorrect body in file{!", Main_Unit_Node);
627 -- Start of processing for Check_Bad_Body
630 -- Nothing to do if we are only checking syntax, because we don't know
631 -- enough to know if we require or forbid a body in this case.
633 if Operating_Mode = Check_Syntax then
637 -- Check for body not allowed
639 if (Main_Kind = N_Package_Declaration
640 and then not Body_Required (Main_Unit_Node))
641 or else (Main_Kind = N_Generic_Package_Declaration
642 and then not Body_Required (Main_Unit_Node))
643 or else Main_Kind = N_Package_Renaming_Declaration
644 or else Main_Kind = N_Subprogram_Renaming_Declaration
645 or else Nkind (Original_Node (Unit (Main_Unit_Node)))
646 in N_Generic_Instantiation
648 Sname := Unit_Name (Main_Unit);
650 -- If we do not already have a body name, then get the body name
651 -- (but how can we have a body name here???)
653 if not Is_Body_Name (Sname) then
654 Sname := Get_Body_Name (Sname);
657 Fname := Get_File_Name (Sname, Subunit => False);
658 Src_Ind := Load_Source_File (Fname);
660 -- Case where body is present and it is not a subunit. Exclude the
661 -- subunit case, because it has nothing to do with the package we are
662 -- compiling. It is illegal for a child unit and a subunit with the
663 -- same expanded name (RM 10.2(9)) to appear together in a partition,
664 -- but there is nothing to stop a compilation environment from having
665 -- both, and the test here simply allows that. If there is an attempt
666 -- to include both in a partition, this is diagnosed at bind time. In
667 -- Ada 83 mode this is not a warning case.
669 -- Note: if weird file names are being used, we can have a situation
670 -- where the file name that supposedly contains body in fact contains
671 -- a spec, or we can't tell what it contains. Skip the error message
674 -- Also ignore body that is nothing but pragma No_Body; (that's the
675 -- whole point of this pragma, to be used this way and to cause the
676 -- body file to be ignored in this context).
678 if Src_Ind /= No_Source_File
679 and then Get_Expected_Unit_Type (Fname) = Expect_Body
680 and then not Source_File_Is_Subunit (Src_Ind)
681 and then not Source_File_Is_No_Body (Src_Ind)
683 Errout.Finalize (Last_Call => False);
685 Error_Msg_Unit_1 := Sname;
687 -- Ada 83 case of a package body being ignored. This is not an
688 -- error as far as the Ada 83 RM is concerned, but it is almost
689 -- certainly not what is wanted so output a warning. Give this
690 -- message only if there were no errors, since otherwise it may
691 -- be incorrect (we may have misinterpreted a junk spec as not
692 -- needing a body when it really does).
694 if Main_Kind = N_Package_Declaration
695 and then Ada_Version = Ada_83
696 and then Operating_Mode = Generate_Code
697 and then Distribution_Stub_Mode /= Generate_Caller_Stub_Body
698 and then not Compilation_Errors
701 ("package $$ does not require a body??", Main_Unit_Node);
702 Error_Msg_File_1 := Fname;
703 Error_Msg_N ("body in file{ will be ignored??", Main_Unit_Node);
705 -- Ada 95 cases of a body file present when no body is
706 -- permitted. This we consider to be an error.
709 -- For generic instantiations, we never allow a body
711 if Nkind (Original_Node (Unit (Main_Unit_Node)))
712 in N_Generic_Instantiation
715 ("generic instantiation for $$ does not allow a body");
717 -- A library unit that is a renaming never allows a body
719 elsif Main_Kind in N_Renaming_Declaration then
721 ("renaming declaration for $$ does not allow a body!");
723 -- Remaining cases are packages and generic packages. Here
724 -- we only do the test if there are no previous errors,
725 -- because if there are errors, they may lead us to
726 -- incorrectly believe that a package does not allow a body
727 -- when in fact it does.
729 elsif not Compilation_Errors then
730 if Main_Kind = N_Package_Declaration then
732 ("package $$ does not allow a body!");
734 elsif Main_Kind = N_Generic_Package_Declaration then
736 ("generic package $$ does not allow a body!");
749 procedure Check_Rep_Info is
751 if List_Representation_Info /= 0
752 or else List_Representation_Info_Mechanisms
757 ("cannot generate representation information, no code generated");
764 -- Start of processing for Gnat1drv
767 -- This inner block is set up to catch assertion errors and constraint
768 -- errors. Since the code for handling these errors can cause another
769 -- exception to be raised (namely Unrecoverable_Error), we need two
770 -- nested blocks, so that the outer one handles unrecoverable error.
773 -- Initialize all packages. For the most part, these initialization
774 -- calls can be made in any order. Exceptions are as follows:
776 -- Lib.Initialize need to be called before Scan_Compiler_Arguments,
777 -- because it initializes a table filled by Scan_Compiler_Arguments.
783 Scan_Compiler_Arguments;
784 Osint.Add_Default_Search_Dirs;
804 Sem_Type.Init_Interp_Tables;
806 -- Acquire target parameters from system.ads (source of package System)
811 S : Source_File_Index;
815 Name_Buffer (1 .. 10) := "system.ads";
818 S := Load_Source_File (N);
820 if S = No_Source_File then
822 ("fatal error, run-time library not installed correctly");
823 Write_Line ("cannot locate file system.ads");
824 raise Unrecoverable_Error;
826 -- Remember source index of system.ads (which was read successfully)
829 System_Source_File_Index := S;
832 Targparm.Get_Target_Parameters
833 (System_Text => Source_Text (S),
834 Source_First => Source_First (S),
835 Source_Last => Source_Last (S));
837 -- Acquire configuration pragma information from Targparm
839 Restrict.Restrictions := Targparm.Restrictions_On_Target;
842 Adjust_Global_Switches;
844 -- Output copyright notice if full list mode unless we have a list
845 -- file, in which case we defer this so that it is output in the file
847 if (Verbose_Mode or else (Full_List and then Full_List_File_Name = null))
848 and then not Debug_Flag_7
852 Write_Str (Gnat_Version_String);
854 Write_Str ("Copyright 1992-" & Current_Year
855 & ", Free Software Foundation, Inc.");
859 -- Check we do not have more than one source file, this happens only in
860 -- the case where the driver is called directly, it cannot happen when
861 -- gnat1 is invoked from gcc in the normal case.
863 if Osint.Number_Of_Files /= 1 then
866 Osint.Fail ("you must provide one source file");
868 elsif Usage_Requested then
872 Original_Operating_Mode := Operating_Mode;
875 -- Exit with errors if the main source could not be parsed. Also, when
876 -- -gnatd.H is present, the source file is not set.
878 if Sinput.Main_Source_File = No_Source_File then
880 -- Handle -gnatd.H debug mode
882 if Debug_Flag_Dot_HH then
884 -- For -gnatd.H, lock all the tables to keep the convention that
885 -- the backend needs to unlock the tables it wants to touch.
898 -- And all we need to do is to call the back end
900 Back_End.Call_Back_End (Back_End.Generate_Object);
903 Errout.Finalize (Last_Call => True);
904 Errout.Output_Messages;
905 Exit_Program (E_Errors);
908 Main_Unit_Node := Cunit (Main_Unit);
909 Main_Kind := Nkind (Unit (Main_Unit_Node));
912 -- In CodePeer mode we always delete old SCIL files before regenerating
913 -- new ones, in case of e.g. errors, and also to remove obsolete scilx
914 -- files generated by CodePeer itself.
916 if CodePeer_Mode then
917 Comperr.Delete_SCIL_Files;
920 -- Exit if compilation errors detected
922 Errout.Finalize (Last_Call => False);
924 if Compilation_Errors then
926 Sem_Ch13.Validate_Unchecked_Conversions;
927 Sem_Ch13.Validate_Address_Clauses;
928 Sem_Ch13.Validate_Independence;
929 Errout.Output_Messages;
932 -- Generate ALI file if specially requested
934 if Opt.Force_ALI_Tree_File then
935 Write_ALI (Object => False);
939 Errout.Finalize (Last_Call => True);
940 Exit_Program (E_Errors);
943 -- Set Generate_Code on main unit and its spec. We do this even if are
944 -- not generating code, since Lib-Writ uses this to determine which
945 -- units get written in the ali file.
947 Set_Generate_Code (Main_Unit);
949 -- If we have a corresponding spec, and it comes from source or it is
950 -- not a generated spec for a child subprogram body, then we need object
951 -- code for the spec unit as well.
953 if Nkind (Unit (Main_Unit_Node)) in N_Unit_Body
954 and then not Acts_As_Spec (Main_Unit_Node)
956 if Nkind (Unit (Main_Unit_Node)) = N_Subprogram_Body
957 and then not Comes_From_Source (Library_Unit (Main_Unit_Node))
962 (Get_Cunit_Unit_Number (Library_Unit (Main_Unit_Node)));
966 -- Case of no code required to be generated, exit indicating no error
968 if Original_Operating_Mode = Check_Syntax then
970 Errout.Finalize (Last_Call => True);
971 Errout.Output_Messages;
976 -- Use a goto instead of calling Exit_Program so that finalization
981 elsif Original_Operating_Mode = Check_Semantics then
982 Back_End_Mode := Declarations_Only;
984 -- All remaining cases are cases in which the user requested that code
985 -- be generated (i.e. no -gnatc or -gnats switch was used). Check if we
986 -- can in fact satisfy this request.
988 -- Cannot generate code if someone has turned off code generation for
989 -- any reason at all. We will try to figure out a reason below.
991 elsif Operating_Mode /= Generate_Code then
992 Back_End_Mode := Skip;
994 -- We can generate code for a subprogram body unless there were missing
995 -- subunits. Note that we always generate code for all generic units (a
996 -- change from some previous versions of GNAT).
998 elsif Main_Kind = N_Subprogram_Body and then not Subunits_Missing then
999 Back_End_Mode := Generate_Object;
1001 -- We can generate code for a package body unless there are subunits
1002 -- missing (note that we always generate code for generic units, which
1003 -- is a change from some earlier versions of GNAT).
1005 elsif Main_Kind = N_Package_Body and then not Subunits_Missing then
1006 Back_End_Mode := Generate_Object;
1008 -- We can generate code for a package declaration or a subprogram
1009 -- declaration only if it does not required a body.
1011 elsif Nkind_In (Main_Kind,
1012 N_Package_Declaration,
1013 N_Subprogram_Declaration)
1015 (not Body_Required (Main_Unit_Node)
1017 Distribution_Stub_Mode = Generate_Caller_Stub_Body)
1019 Back_End_Mode := Generate_Object;
1021 -- We can generate code for a generic package declaration of a generic
1022 -- subprogram declaration only if does not require a body.
1024 elsif Nkind_In (Main_Kind, N_Generic_Package_Declaration,
1025 N_Generic_Subprogram_Declaration)
1026 and then not Body_Required (Main_Unit_Node)
1028 Back_End_Mode := Generate_Object;
1030 -- Compilation units that are renamings do not require bodies, so we can
1031 -- generate code for them.
1033 elsif Nkind_In (Main_Kind, N_Package_Renaming_Declaration,
1034 N_Subprogram_Renaming_Declaration)
1036 Back_End_Mode := Generate_Object;
1038 -- Compilation units that are generic renamings do not require bodies
1039 -- so we can generate code for them.
1041 elsif Main_Kind in N_Generic_Renaming_Declaration then
1042 Back_End_Mode := Generate_Object;
1044 -- It is not an error to analyze (in CodePeer or Alfa modes) a spec
1045 -- which requires a body, when the body is not available.
1047 elsif CodePeer_Mode or Alfa_Mode then
1048 Back_End_Mode := Generate_Object;
1050 -- In all other cases (specs which have bodies, generics, and bodies
1051 -- where subunits are missing), we cannot generate code and we generate
1052 -- a warning message. Note that generic instantiations are gone at this
1053 -- stage since they have been replaced by their instances.
1056 Back_End_Mode := Skip;
1059 -- At this stage Back_End_Mode is set to indicate if the backend should
1060 -- be called to generate code. If it is Skip, then code generation has
1061 -- been turned off, even though code was requested by the original
1062 -- command. This is not an error from the user point of view, but it is
1063 -- an error from the point of view of the gcc driver, so we must exit
1064 -- with an error status.
1066 -- We generate an informative message (from the gcc point of view, it
1067 -- is an error message, but from the users point of view this is not an
1068 -- error, just a consequence of compiling something that cannot
1071 if Back_End_Mode = Skip then
1073 Write_Str ("cannot generate code for ");
1074 Write_Str ("file ");
1075 Write_Name (Unit_File_Name (Main_Unit));
1077 if Subunits_Missing then
1078 Write_Str (" (missing subunits)");
1081 -- Force generation of ALI file, for backward compatibility
1083 Opt.Force_ALI_Tree_File := True;
1085 elsif Main_Kind = N_Subunit then
1086 Write_Str (" (subunit)");
1089 -- Force generation of ALI file, for backward compatibility
1091 Opt.Force_ALI_Tree_File := True;
1093 elsif Main_Kind = N_Subprogram_Declaration then
1094 Write_Str (" (subprogram spec)");
1097 -- Generic package body in GNAT implementation mode
1099 elsif Main_Kind = N_Package_Body and then GNAT_Mode then
1100 Write_Str (" (predefined generic)");
1103 -- Force generation of ALI file, for backward compatibility
1105 Opt.Force_ALI_Tree_File := True;
1107 -- Only other case is a package spec
1110 Write_Str (" (package spec)");
1114 Set_Standard_Output;
1116 Sem_Ch13.Validate_Unchecked_Conversions;
1117 Sem_Ch13.Validate_Address_Clauses;
1118 Sem_Ch13.Validate_Independence;
1119 Errout.Finalize (Last_Call => True);
1120 Errout.Output_Messages;
1124 -- Generate ALI file if specially requested, or for missing subunits,
1125 -- subunits or predefined generic.
1127 if Opt.Force_ALI_Tree_File then
1128 Write_ALI (Object => False);
1134 -- Exit program with error indication, to kill object file
1136 Exit_Program (E_No_Code);
1139 -- In -gnatc mode, we only do annotation if -gnatt or -gnatR is also set
1140 -- as indicated by Back_Annotate_Rep_Info being set to True.
1142 -- We don't call for annotations on a subunit, because to process those
1143 -- the back-end requires that the parent(s) be properly compiled.
1145 -- Annotation is suppressed for targets where front-end layout is
1146 -- enabled, because the front end determines representations.
1148 -- Annotation is also suppressed in the case of compiling for a VM,
1149 -- since representations are largely symbolic there.
1151 if Back_End_Mode = Declarations_Only
1152 and then (not (Back_Annotate_Rep_Info or Generate_SCIL)
1153 or else Main_Kind = N_Subunit
1154 or else Targparm.Frontend_Layout_On_Target
1155 or else Targparm.VM_Target /= No_VM)
1157 Sem_Ch13.Validate_Unchecked_Conversions;
1158 Sem_Ch13.Validate_Address_Clauses;
1159 Sem_Ch13.Validate_Independence;
1160 Errout.Finalize (Last_Call => True);
1161 Errout.Output_Messages;
1162 Write_ALI (Object => False);
1170 -- Ensure that we properly register a dependency on system.ads, since
1171 -- even if we do not semantically depend on this, Targparm has read
1172 -- system parameters from the system.ads file.
1174 Lib.Writ.Ensure_System_Dependency;
1176 -- Add dependencies, if any, on preprocessing data file and on
1177 -- preprocessing definition file(s).
1179 Prepcomp.Add_Dependencies;
1181 -- Back end needs to explicitly unlock tables it needs to touch
1194 -- Here we call the back end to generate the output code
1196 Generating_Code := True;
1197 Back_End.Call_Back_End (Back_End_Mode);
1199 -- Once the backend is complete, we unlock the names table. This call
1200 -- allows a few extra entries, needed for example for the file name for
1201 -- the library file output.
1205 -- Generate the call-graph output of dispatching calls
1207 Exp_CG.Generate_CG_Output;
1209 -- Validate unchecked conversions (using the values for size and
1210 -- alignment annotated by the backend where possible).
1212 Sem_Ch13.Validate_Unchecked_Conversions;
1214 -- Validate address clauses (again using alignment values annotated
1215 -- by the backend where possible).
1217 Sem_Ch13.Validate_Address_Clauses;
1219 -- Validate independence pragmas (again using values annotated by
1220 -- the back end for component layout etc.)
1222 Sem_Ch13.Validate_Independence;
1224 -- Now we complete output of errors, rep info and the tree info. These
1225 -- are delayed till now, since it is perfectly possible for gigi to
1226 -- generate errors, modify the tree (in particular by setting flags
1227 -- indicating that elaboration is required, and also to back annotate
1228 -- representation information for List_Rep_Info.
1230 Errout.Finalize (Last_Call => True);
1231 Errout.Output_Messages;
1235 -- Only write the library if the backend did not generate any error
1236 -- messages. Otherwise signal errors to the driver program so that
1237 -- there will be no attempt to generate an object file.
1239 if Compilation_Errors then
1241 Exit_Program (E_Errors);
1244 Write_ALI (Object => (Back_End_Mode = Generate_Object));
1246 if not Compilation_Errors then
1248 -- In case of ada backends, we need to make sure that the generated
1249 -- object file has a timestamp greater than the ALI file. We do this
1250 -- to make gnatmake happy when checking the ALI and obj timestamps,
1251 -- where it expects the object file being written after the ali file.
1253 -- Gnatmake's assumption is true for gcc platforms where the gcc
1254 -- wrapper needs to call the assembler after calling gnat1, but is
1255 -- not true for ada backends, where the object files are created
1256 -- directly by gnat1 (so are created before the ali file).
1258 Back_End.Gen_Or_Update_Object_File;
1261 -- Generate ASIS tree after writing the ALI file, since in ASIS mode,
1262 -- Write_ALI may in fact result in further tree decoration from the
1263 -- original tree file. Note that we dump the tree just before generating
1264 -- it, so that the dump will exactly reflect what is written out.
1269 -- Finalize name table and we are all done
1274 -- Handle fatal internal compiler errors
1276 when Rtsfind.RE_Not_Available =>
1277 Comperr.Compiler_Abort ("RE_Not_Available");
1279 when System.Assertions.Assert_Failure =>
1280 Comperr.Compiler_Abort ("Assert_Failure");
1282 when Constraint_Error =>
1283 Comperr.Compiler_Abort ("Constraint_Error");
1285 when Program_Error =>
1286 Comperr.Compiler_Abort ("Program_Error");
1288 when Storage_Error =>
1290 -- Assume this is a bug. If it is real, the message will in any case
1291 -- say Storage_Error, giving a strong hint!
1293 Comperr.Compiler_Abort ("Storage_Error");
1299 -- The outer exception handles an unrecoverable error
1302 when Unrecoverable_Error =>
1303 Errout.Finalize (Last_Call => True);
1304 Errout.Output_Messages;
1307 Write_Str ("compilation abandoned");
1310 Set_Standard_Output;
1313 Exit_Program (E_Errors);