1 ------------------------------------------------------------------------------
3 -- GNAT COMPILER COMPONENTS --
9 -- Copyright (C) 1992-2011, 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;
35 with Fname; use Fname;
36 with Fname.UF; use Fname.UF;
38 with Gnatvsn; use Gnatvsn;
42 with Lib.Writ; use Lib.Writ;
44 with Namet; use Namet;
47 with Osint; use Osint;
48 with Output; use Output;
51 with Repinfo; use Repinfo;
53 with Rident; use Rident;
63 with Sinfo; use Sinfo;
64 with Sinput.L; use Sinput.L;
66 with Sprint; use Sprint;
68 with Stylesw; use Stylesw;
69 with Targparm; use Targparm;
71 with Treepr; use Treepr;
73 with Types; use Types;
74 with Uintp; use Uintp;
75 with Uname; use Uname;
78 with Validsw; use Validsw;
80 with System.Assertions;
83 Main_Unit_Node : Node_Id;
84 -- Compilation unit node for main unit
86 Main_Kind : Node_Kind;
87 -- Kind of main compilation unit node
89 Back_End_Mode : Back_End.Back_End_Mode_Type;
90 -- Record back end mode
92 procedure Adjust_Global_Switches;
93 -- There are various interactions between front end switch settings,
94 -- including debug switch settings and target dependent parameters.
95 -- This procedure takes care of properly handling these interactions.
96 -- We do it after scanning out all the switches, so that we are not
97 -- depending on the order in which switches appear.
99 procedure Check_Bad_Body;
100 -- Called to check if the unit we are compiling has a bad body
102 procedure Check_Rep_Info;
103 -- Called when we are not generating code, to check if -gnatR was requested
104 -- and if so, explain that we will not be honoring the request.
106 procedure Check_Library_Items;
107 -- For debugging -- checks the behavior of Walk_Library_Items
108 pragma Warnings (Off, Check_Library_Items);
109 -- In case the call below is commented out
111 ----------------------------
112 -- Adjust_Global_Switches --
113 ----------------------------
115 procedure Adjust_Global_Switches is
117 -- Debug flag -gnatd.I is a synonym for Generate_SCIL and requires code
121 and then Operating_Mode = Generate_Code
123 Generate_SCIL := True;
126 -- Disable CodePeer_Mode in Check_Syntax, since we need front-end
129 if Operating_Mode = Check_Syntax then
130 CodePeer_Mode := False;
133 -- Set ASIS mode if -gnatt and -gnatc are set
135 if Operating_Mode = Check_Semantics and then Tree_Output then
138 -- Turn off inlining in ASIS mode, since ASIS cannot handle the extra
139 -- information in the trees caused by inlining being active.
141 -- More specifically, the tree seems to be malformed from the ASIS
142 -- point of view if -gnatc and -gnatn appear together???
144 Inline_Active := False;
146 -- Turn off SCIL generation and CodePeer mode in semantics mode,
147 -- since SCIL requires front-end expansion.
149 Generate_SCIL := False;
150 CodePeer_Mode := False;
153 -- SCIL mode needs to disable front-end inlining since the generated
154 -- trees (in particular order and consistency between specs compiled
155 -- as part of a main unit or as part of a with-clause) are causing
158 if Generate_SCIL then
159 Front_End_Inlining := False;
162 -- Tune settings for optimal SCIL generation in CodePeer mode
164 if CodePeer_Mode then
166 -- Turn off inlining, confuses CodePeer output and gains nothing
168 Front_End_Inlining := False;
169 Inline_Active := False;
171 -- Disable front-end optimizations, to keep the tree as close to the
172 -- source code as possible, and also to avoid inconsistencies between
173 -- trees when using different optimization switches.
175 Optimization_Level := 0;
177 -- Enable some restrictions systematically to simplify the generated
178 -- code (and ease analysis). Note that restriction checks are also
179 -- disabled in CodePeer mode, see Restrict.Check_Restriction, and
180 -- user specified Restrictions pragmas are ignored, see
181 -- Sem_Prag.Process_Restrictions_Or_Restriction_Warnings.
183 Restrict.Restrictions.Set (No_Initialize_Scalars) := True;
184 Restrict.Restrictions.Set (No_Task_Hierarchy) := True;
185 Restrict.Restrictions.Set (No_Abort_Statements) := True;
186 Restrict.Restrictions.Set (Max_Asynchronous_Select_Nesting) := True;
187 Restrict.Restrictions.Value (Max_Asynchronous_Select_Nesting) := 0;
189 -- Suppress overflow, division by zero and access checks since they
190 -- are handled implicitly by CodePeer.
192 -- Turn off dynamic elaboration checks: generates inconsistencies in
193 -- trees between specs compiled as part of a main unit or as part of
196 -- Turn off alignment checks: these cannot be proved statically by
197 -- CodePeer and generate false positives.
199 -- Enable all other language checks
202 (Access_Check => True,
203 Alignment_Check => True,
204 Division_Check => True,
205 Elaboration_Check => True,
206 Overflow_Check => True,
208 Enable_Overflow_Checks := False;
209 Dynamic_Elaboration_Checks := False;
211 -- Kill debug of generated code, since it messes up sloc values
213 Debug_Generated_Code := False;
215 -- Turn cross-referencing on in case it was disabled (e.g. by -gnatD)
216 -- Do we really need to spend time generating xref in CodePeer
217 -- mode??? Consider setting Xref_Active to False.
221 -- Polling mode forced off, since it generates confusing junk
223 Polling_Required := False;
225 -- Set operating mode to Generate_Code to benefit from full front-end
226 -- expansion (e.g. generics).
228 Operating_Mode := Generate_Code;
230 -- We need SCIL generation of course
232 Generate_SCIL := True;
234 -- Enable assertions and debug pragmas, since they give CodePeer
235 -- valuable extra information.
237 Assertions_Enabled := True;
238 Debug_Pragmas_Enabled := True;
240 -- Disable all simple value propagation. This is an optimization
241 -- which is valuable for code optimization, and also for generation
242 -- of compiler warnings, but these are being turned off by default,
243 -- and CodePeer generates better messages (referencing original
244 -- variables) this way.
246 Debug_Flag_MM := True;
248 -- Set normal RM validity checking, and checking of IN OUT parameters
249 -- (this might give CodePeer more useful checks to analyze, to be
250 -- confirmed???). All other validity checking is turned off, since
251 -- this can generate very complex trees that only confuse CodePeer
252 -- and do not bring enough useful info.
254 Reset_Validity_Check_Options;
255 Validity_Check_Default := True;
256 Validity_Check_In_Out_Params := True;
257 Validity_Check_In_Params := True;
259 -- Turn off style check options since we are not interested in any
260 -- front-end warnings when we are getting CodePeer output.
262 Reset_Style_Check_Options;
264 -- Always perform semantics and generate ali files in CodePeer mode,
265 -- so that a gnatmake -c -k will proceed further when possible.
267 Force_ALI_Tree_File := True;
268 Try_Semantics := True;
271 -- Set Configurable_Run_Time mode if system.ads flag set
273 if Targparm.Configurable_Run_Time_On_Target or Debug_Flag_YY then
274 Configurable_Run_Time_Mode := True;
277 -- Set -gnatR3m mode if debug flag A set
279 if Debug_Flag_AA then
280 Back_Annotate_Rep_Info := True;
281 List_Representation_Info := 1;
282 List_Representation_Info_Mechanisms := True;
285 -- Force Target_Strict_Alignment true if debug flag -gnatd.a is set
287 if Debug_Flag_Dot_A then
288 Ttypes.Target_Strict_Alignment := True;
291 -- Disable static allocation of dispatch tables if -gnatd.t or if layout
292 -- is enabled. The front end's layout phase currently treats types that
293 -- have discriminant-dependent arrays as not being static even when a
294 -- discriminant constraint on the type is static, and this leads to
295 -- problems with subtypes of type Ada.Tags.Dispatch_Table_Wrapper. ???
297 if Debug_Flag_Dot_T or else Frontend_Layout_On_Target then
298 Static_Dispatch_Tables := False;
301 -- Flip endian mode if -gnatd8 set
304 Ttypes.Bytes_Big_Endian := not Ttypes.Bytes_Big_Endian;
307 -- Deal with forcing OpenVMS switches True if debug flag M is set, but
308 -- record the setting of Targparm.Open_VMS_On_Target in True_VMS_Target
309 -- before doing this, so we know if we are in real OpenVMS or not!
311 Opt.True_VMS_Target := Targparm.OpenVMS_On_Target;
314 Targparm.OpenVMS_On_Target := True;
315 Hostparm.OpenVMS := True;
318 -- Activate front end layout if debug flag -gnatdF is set
320 if Debug_Flag_FF then
321 Targparm.Frontend_Layout_On_Target := True;
324 -- Set and check exception mechanism
326 if Targparm.ZCX_By_Default_On_Target then
327 if Targparm.GCC_ZCX_Support_On_Target then
328 Exception_Mechanism := Back_End_Exceptions;
330 Osint.Fail ("Zero Cost Exceptions not supported on this target");
334 -- Set proper status for overflow checks. We turn on overflow checks if
335 -- -gnatp was not specified, and either -gnato is set or the back-end
336 -- takes care of overflow checks. Otherwise we suppress overflow checks
337 -- by default (since front end checks are expensive).
339 if not Opt.Suppress_Checks
340 and then (Opt.Enable_Overflow_Checks
342 (Targparm.Backend_Divide_Checks_On_Target
344 Targparm.Backend_Overflow_Checks_On_Target))
346 Suppress_Options (Overflow_Check) := False;
348 Suppress_Options (Overflow_Check) := True;
351 -- Set switch indicating if we can use N_Expression_With_Actions
353 -- Debug flag -gnatd.X decisively sets usage on
355 if Debug_Flag_Dot_XX then
356 Use_Expression_With_Actions := True;
358 -- Debug flag -gnatd.Y decisively sets usage off
360 elsif Debug_Flag_Dot_YY then
361 Use_Expression_With_Actions := False;
363 -- Otherwise this feature is implemented, so we allow its use
366 Use_Expression_With_Actions := True;
369 -- Set switch indicating if back end can handle limited types, and
370 -- guarantee that no incorrect copies are made (e.g. in the context
371 -- of a conditional expression).
373 -- Debug flag -gnatd.L decisively sets usage on
375 if Debug_Flag_Dot_LL then
376 Back_End_Handles_Limited_Types := True;
378 -- If no debug flag, usage off for AAMP, VM, SCIL cases
381 or else VM_Target /= No_VM
382 or else Generate_SCIL
384 Back_End_Handles_Limited_Types := False;
386 -- Otherwise normal gcc back end, for now still turn flag off by
387 -- default, since there are unresolved problems in the front end.
390 Back_End_Handles_Limited_Types := False;
393 -- Set switches for formal verification mode
395 if Debug_Flag_Dot_FF then
399 -- Turn off inlining, which would confuse formal verification output
402 Front_End_Inlining := False;
403 Inline_Active := False;
405 -- Disable front-end optimizations, to keep the tree as close to the
406 -- source code as possible, and also to avoid inconsistencies between
407 -- trees when using different optimization switches.
409 Optimization_Level := 0;
411 -- Enable some restrictions systematically to simplify the generated
412 -- code (and ease analysis). Note that restriction checks are also
413 -- disabled in ALFA mode, see Restrict.Check_Restriction, and user
414 -- specified Restrictions pragmas are ignored, see
415 -- Sem_Prag.Process_Restrictions_Or_Restriction_Warnings.
417 Restrict.Restrictions.Set (No_Initialize_Scalars) := True;
419 -- Suppress all language checks since they are handled implicitly by
420 -- the formal verification backend.
421 -- Turn off dynamic elaboration checks.
422 -- Turn off alignment checks.
423 -- Turn off validity checking.
425 Suppress_Options := (others => True);
426 Enable_Overflow_Checks := False;
427 Dynamic_Elaboration_Checks := False;
428 Reset_Validity_Check_Options;
430 -- Kill debug of generated code, since it messes up sloc values
432 Debug_Generated_Code := False;
434 -- Turn cross-referencing on in case it was disabled (e.g. by -gnatD)
438 -- Polling mode forced off, since it generates confusing junk
440 Polling_Required := False;
442 -- Set operating mode to Generate_Code to benefit from full front-end
443 -- expansion (e.g. default arguments).
445 Operating_Mode := Generate_Code;
449 Debug_Flag_HH := True;
451 -- Enable assertions and debug pragmas, since they give valuable
452 -- extra information for formal verification.
454 Assertions_Enabled := True;
455 Debug_Pragmas_Enabled := True;
457 -- Turn off style check options since we are not interested in any
458 -- front-end warnings when we are getting ALFA output.
460 Reset_Style_Check_Options;
462 -- Suppress compiler warnings, since what we are
463 -- interested in here is what formal verification can find out.
465 Warning_Mode := Suppress;
467 -- Always perform semantics and generate ALI files in ALFA mode,
468 -- so that a gnatmake -c -k will proceed further when possible.
470 Force_ALI_Tree_File := True;
471 Try_Semantics := True;
473 end Adjust_Global_Switches;
479 procedure Check_Bad_Body is
480 Sname : Unit_Name_Type;
481 Src_Ind : Source_File_Index;
482 Fname : File_Name_Type;
484 procedure Bad_Body_Error (Msg : String);
485 -- Issue message for bad body found
491 procedure Bad_Body_Error (Msg : String) is
493 Error_Msg_N (Msg, Main_Unit_Node);
494 Error_Msg_File_1 := Fname;
495 Error_Msg_N ("remove incorrect body in file{!", Main_Unit_Node);
498 -- Start of processing for Check_Bad_Body
501 -- Nothing to do if we are only checking syntax, because we don't know
502 -- enough to know if we require or forbid a body in this case.
504 if Operating_Mode = Check_Syntax then
508 -- Check for body not allowed
510 if (Main_Kind = N_Package_Declaration
511 and then not Body_Required (Main_Unit_Node))
512 or else (Main_Kind = N_Generic_Package_Declaration
513 and then not Body_Required (Main_Unit_Node))
514 or else Main_Kind = N_Package_Renaming_Declaration
515 or else Main_Kind = N_Subprogram_Renaming_Declaration
516 or else Nkind (Original_Node (Unit (Main_Unit_Node)))
517 in N_Generic_Instantiation
519 Sname := Unit_Name (Main_Unit);
521 -- If we do not already have a body name, then get the body name
522 -- (but how can we have a body name here???)
524 if not Is_Body_Name (Sname) then
525 Sname := Get_Body_Name (Sname);
528 Fname := Get_File_Name (Sname, Subunit => False);
529 Src_Ind := Load_Source_File (Fname);
531 -- Case where body is present and it is not a subunit. Exclude the
532 -- subunit case, because it has nothing to do with the package we are
533 -- compiling. It is illegal for a child unit and a subunit with the
534 -- same expanded name (RM 10.2(9)) to appear together in a partition,
535 -- but there is nothing to stop a compilation environment from having
536 -- both, and the test here simply allows that. If there is an attempt
537 -- to include both in a partition, this is diagnosed at bind time. In
538 -- Ada 83 mode this is not a warning case.
540 -- Note: if weird file names are being used, we can have a situation
541 -- where the file name that supposedly contains body in fact contains
542 -- a spec, or we can't tell what it contains. Skip the error message
545 -- Also ignore body that is nothing but pragma No_Body; (that's the
546 -- whole point of this pragma, to be used this way and to cause the
547 -- body file to be ignored in this context).
549 if Src_Ind /= No_Source_File
550 and then Get_Expected_Unit_Type (Fname) = Expect_Body
551 and then not Source_File_Is_Subunit (Src_Ind)
552 and then not Source_File_Is_No_Body (Src_Ind)
554 Errout.Finalize (Last_Call => False);
556 Error_Msg_Unit_1 := Sname;
558 -- Ada 83 case of a package body being ignored. This is not an
559 -- error as far as the Ada 83 RM is concerned, but it is almost
560 -- certainly not what is wanted so output a warning. Give this
561 -- message only if there were no errors, since otherwise it may
562 -- be incorrect (we may have misinterpreted a junk spec as not
563 -- needing a body when it really does).
565 if Main_Kind = N_Package_Declaration
566 and then Ada_Version = Ada_83
567 and then Operating_Mode = Generate_Code
568 and then Distribution_Stub_Mode /= Generate_Caller_Stub_Body
569 and then not Compilation_Errors
572 ("package $$ does not require a body?", Main_Unit_Node);
573 Error_Msg_File_1 := Fname;
574 Error_Msg_N ("body in file{? will be ignored", Main_Unit_Node);
576 -- Ada 95 cases of a body file present when no body is
577 -- permitted. This we consider to be an error.
580 -- For generic instantiations, we never allow a body
582 if Nkind (Original_Node (Unit (Main_Unit_Node)))
583 in N_Generic_Instantiation
586 ("generic instantiation for $$ does not allow a body");
588 -- A library unit that is a renaming never allows a body
590 elsif Main_Kind in N_Renaming_Declaration then
592 ("renaming declaration for $$ does not allow a body!");
594 -- Remaining cases are packages and generic packages. Here
595 -- we only do the test if there are no previous errors,
596 -- because if there are errors, they may lead us to
597 -- incorrectly believe that a package does not allow a body
598 -- when in fact it does.
600 elsif not Compilation_Errors then
601 if Main_Kind = N_Package_Declaration then
603 ("package $$ does not allow a body!");
605 elsif Main_Kind = N_Generic_Package_Declaration then
607 ("generic package $$ does not allow a body!");
616 -------------------------
617 -- Check_Library_Items --
618 -------------------------
620 -- Walk_Library_Items has plenty of assertions, so all we need to do is
621 -- call it, just for these assertions, not actually doing anything else.
623 procedure Check_Library_Items is
625 procedure Action (Item : Node_Id);
626 -- Action passed to Walk_Library_Items to do nothing
632 procedure Action (Item : Node_Id) is
637 procedure Walk is new Sem.Walk_Library_Items (Action);
639 -- Start of processing for Check_Library_Items
643 end Check_Library_Items;
649 procedure Check_Rep_Info is
651 if List_Representation_Info /= 0
652 or else List_Representation_Info_Mechanisms
657 ("cannot generate representation information, no code generated");
664 -- Start of processing for Gnat1drv
667 -- This inner block is set up to catch assertion errors and constraint
668 -- errors. Since the code for handling these errors can cause another
669 -- exception to be raised (namely Unrecoverable_Error), we need two
670 -- nested blocks, so that the outer one handles unrecoverable error.
673 -- Initialize all packages. For the most part, these initialization
674 -- calls can be made in any order. Exceptions are as follows:
676 -- Lib.Initialize need to be called before Scan_Compiler_Arguments,
677 -- because it initializes a table filled by Scan_Compiler_Arguments.
683 Scan_Compiler_Arguments;
684 Osint.Add_Default_Search_Dirs;
704 Sem_Type.Init_Interp_Tables;
706 -- Acquire target parameters from system.ads (source of package System)
711 S : Source_File_Index;
715 Name_Buffer (1 .. 10) := "system.ads";
718 S := Load_Source_File (N);
720 if S = No_Source_File then
722 ("fatal error, run-time library not installed correctly");
723 Write_Line ("cannot locate file system.ads");
724 raise Unrecoverable_Error;
726 -- Remember source index of system.ads (which was read successfully)
729 System_Source_File_Index := S;
732 Targparm.Get_Target_Parameters
733 (System_Text => Source_Text (S),
734 Source_First => Source_First (S),
735 Source_Last => Source_Last (S));
737 -- Acquire configuration pragma information from Targparm
739 Restrict.Restrictions := Targparm.Restrictions_On_Target;
742 Adjust_Global_Switches;
744 -- Output copyright notice if full list mode unless we have a list
745 -- file, in which case we defer this so that it is output in the file
747 if (Verbose_Mode or else (Full_List and then Full_List_File_Name = null))
748 and then not Debug_Flag_7
752 Write_Str (Gnat_Version_String);
754 Write_Str ("Copyright 1992-" & Current_Year
755 & ", Free Software Foundation, Inc.");
759 -- Check we do not have more than one source file, this happens only in
760 -- the case where the driver is called directly, it cannot happen when
761 -- gnat1 is invoked from gcc in the normal case.
763 if Osint.Number_Of_Files /= 1 then
766 Osint.Fail ("you must provide one source file");
768 elsif Usage_Requested then
772 Original_Operating_Mode := Operating_Mode;
775 -- Exit with errors if the main source could not be parsed
777 if Sinput.Main_Source_File = No_Source_File then
778 Errout.Finalize (Last_Call => True);
779 Errout.Output_Messages;
780 Exit_Program (E_Errors);
783 Main_Unit_Node := Cunit (Main_Unit);
784 Main_Kind := Nkind (Unit (Main_Unit_Node));
787 -- Exit if compilation errors detected
789 Errout.Finalize (Last_Call => False);
791 if Compilation_Errors then
793 Sem_Ch13.Validate_Unchecked_Conversions;
794 Sem_Ch13.Validate_Address_Clauses;
795 Sem_Ch13.Validate_Independence;
796 Errout.Output_Messages;
799 -- Generate ALI file if specially requested
801 if Opt.Force_ALI_Tree_File then
802 Write_ALI (Object => False);
806 Errout.Finalize (Last_Call => True);
807 Exit_Program (E_Errors);
810 -- Set Generate_Code on main unit and its spec. We do this even if are
811 -- not generating code, since Lib-Writ uses this to determine which
812 -- units get written in the ali file.
814 Set_Generate_Code (Main_Unit);
816 -- If we have a corresponding spec, and it comes from source or it is
817 -- not a generated spec for a child subprogram body, then we need object
818 -- code for the spec unit as well.
820 if Nkind (Unit (Main_Unit_Node)) in N_Unit_Body
821 and then not Acts_As_Spec (Main_Unit_Node)
823 if Nkind (Unit (Main_Unit_Node)) = N_Subprogram_Body
824 and then not Comes_From_Source (Library_Unit (Main_Unit_Node))
829 (Get_Cunit_Unit_Number (Library_Unit (Main_Unit_Node)));
833 -- Case of no code required to be generated, exit indicating no error
835 if Original_Operating_Mode = Check_Syntax then
837 Errout.Finalize (Last_Call => True);
838 Errout.Output_Messages;
843 -- Use a goto instead of calling Exit_Program so that finalization
848 elsif Original_Operating_Mode = Check_Semantics then
849 Back_End_Mode := Declarations_Only;
851 -- All remaining cases are cases in which the user requested that code
852 -- be generated (i.e. no -gnatc or -gnats switch was used). Check if we
853 -- can in fact satisfy this request.
855 -- Cannot generate code if someone has turned off code generation for
856 -- any reason at all. We will try to figure out a reason below.
858 elsif Operating_Mode /= Generate_Code then
859 Back_End_Mode := Skip;
861 -- We can generate code for a subprogram body unless there were missing
862 -- subunits. Note that we always generate code for all generic units (a
863 -- change from some previous versions of GNAT).
865 elsif Main_Kind = N_Subprogram_Body and then not Subunits_Missing then
866 Back_End_Mode := Generate_Object;
868 -- We can generate code for a package body unless there are subunits
869 -- missing (note that we always generate code for generic units, which
870 -- is a change from some earlier versions of GNAT).
872 elsif Main_Kind = N_Package_Body and then not Subunits_Missing then
873 Back_End_Mode := Generate_Object;
875 -- We can generate code for a package declaration or a subprogram
876 -- declaration only if it does not required a body.
878 elsif Nkind_In (Main_Kind,
879 N_Package_Declaration,
880 N_Subprogram_Declaration)
882 (not Body_Required (Main_Unit_Node)
884 Distribution_Stub_Mode = Generate_Caller_Stub_Body)
886 Back_End_Mode := Generate_Object;
888 -- We can generate code for a generic package declaration of a generic
889 -- subprogram declaration only if does not require a body.
891 elsif Nkind_In (Main_Kind, N_Generic_Package_Declaration,
892 N_Generic_Subprogram_Declaration)
893 and then not Body_Required (Main_Unit_Node)
895 Back_End_Mode := Generate_Object;
897 -- Compilation units that are renamings do not require bodies, so we can
898 -- generate code for them.
900 elsif Nkind_In (Main_Kind, N_Package_Renaming_Declaration,
901 N_Subprogram_Renaming_Declaration)
903 Back_End_Mode := Generate_Object;
905 -- Compilation units that are generic renamings do not require bodies
906 -- so we can generate code for them.
908 elsif Main_Kind in N_Generic_Renaming_Declaration then
909 Back_End_Mode := Generate_Object;
911 -- It's not an error to generate SCIL for e.g. a spec which has a body
913 elsif CodePeer_Mode then
914 Back_End_Mode := Generate_Object;
916 -- In all other cases (specs which have bodies, generics, and bodies
917 -- where subunits are missing), we cannot generate code and we generate
918 -- a warning message. Note that generic instantiations are gone at this
919 -- stage since they have been replaced by their instances.
922 Back_End_Mode := Skip;
925 -- At this stage Back_End_Mode is set to indicate if the backend should
926 -- be called to generate code. If it is Skip, then code generation has
927 -- been turned off, even though code was requested by the original
928 -- command. This is not an error from the user point of view, but it is
929 -- an error from the point of view of the gcc driver, so we must exit
930 -- with an error status.
932 -- We generate an informative message (from the gcc point of view, it
933 -- is an error message, but from the users point of view this is not an
934 -- error, just a consequence of compiling something that cannot
937 if Back_End_Mode = Skip then
939 Write_Str ("cannot generate code for ");
941 Write_Name (Unit_File_Name (Main_Unit));
943 if Subunits_Missing then
944 Write_Str (" (missing subunits)");
947 -- Force generation of ALI file, for backward compatibility
949 Opt.Force_ALI_Tree_File := True;
951 elsif Main_Kind = N_Subunit then
952 Write_Str (" (subunit)");
955 -- Force generation of ALI file, for backward compatibility
957 Opt.Force_ALI_Tree_File := True;
959 elsif Main_Kind = N_Subprogram_Declaration then
960 Write_Str (" (subprogram spec)");
963 -- Generic package body in GNAT implementation mode
965 elsif Main_Kind = N_Package_Body and then GNAT_Mode then
966 Write_Str (" (predefined generic)");
969 -- Force generation of ALI file, for backward compatibility
971 Opt.Force_ALI_Tree_File := True;
973 -- Only other case is a package spec
976 Write_Str (" (package spec)");
982 Sem_Ch13.Validate_Unchecked_Conversions;
983 Sem_Ch13.Validate_Address_Clauses;
984 Sem_Ch13.Validate_Independence;
985 Errout.Finalize (Last_Call => True);
986 Errout.Output_Messages;
990 -- Generate ALI file if specially requested, or for missing subunits,
991 -- subunits or predefined generic.
993 if Opt.Force_ALI_Tree_File then
994 Write_ALI (Object => False);
1000 -- Exit program with error indication, to kill object file
1002 Exit_Program (E_No_Code);
1005 -- In -gnatc mode, we only do annotation if -gnatt or -gnatR is also set
1006 -- as indicated by Back_Annotate_Rep_Info being set to True.
1008 -- We don't call for annotations on a subunit, because to process those
1009 -- the back-end requires that the parent(s) be properly compiled.
1011 -- Annotation is suppressed for targets where front-end layout is
1012 -- enabled, because the front end determines representations.
1014 -- Annotation is also suppressed in the case of compiling for a VM,
1015 -- since representations are largely symbolic there.
1017 if Back_End_Mode = Declarations_Only
1018 and then (not (Back_Annotate_Rep_Info or Generate_SCIL)
1019 or else Main_Kind = N_Subunit
1020 or else Targparm.Frontend_Layout_On_Target
1021 or else Targparm.VM_Target /= No_VM)
1023 Sem_Ch13.Validate_Unchecked_Conversions;
1024 Sem_Ch13.Validate_Address_Clauses;
1025 Sem_Ch13.Validate_Independence;
1026 Errout.Finalize (Last_Call => True);
1027 Errout.Output_Messages;
1028 Write_ALI (Object => False);
1036 -- Ensure that we properly register a dependency on system.ads, since
1037 -- even if we do not semantically depend on this, Targparm has read
1038 -- system parameters from the system.ads file.
1040 Lib.Writ.Ensure_System_Dependency;
1042 -- Add dependencies, if any, on preprocessing data file and on
1043 -- preprocessing definition file(s).
1045 Prepcomp.Add_Dependencies;
1047 -- Back end needs to explicitly unlock tables it needs to touch
1060 -- ???Check_Library_Items under control of a debug flag, because it
1061 -- currently does not work if the -gnatn switch (back end inlining) is
1064 if Debug_Flag_Dot_WW then
1065 Check_Library_Items;
1068 -- Here we call the back end to generate the output code
1070 Generating_Code := True;
1071 Back_End.Call_Back_End (Back_End_Mode);
1073 -- Once the backend is complete, we unlock the names table. This call
1074 -- allows a few extra entries, needed for example for the file name for
1075 -- the library file output.
1079 -- Generate the call-graph output of dispatching calls
1081 Exp_CG.Generate_CG_Output;
1083 -- Validate unchecked conversions (using the values for size and
1084 -- alignment annotated by the backend where possible).
1086 Sem_Ch13.Validate_Unchecked_Conversions;
1088 -- Validate address clauses (again using alignment values annotated
1089 -- by the backend where possible).
1091 Sem_Ch13.Validate_Address_Clauses;
1093 -- Validate independence pragmas (again using values annotated by
1094 -- the back end for component layout etc.)
1096 Sem_Ch13.Validate_Independence;
1098 -- Now we complete output of errors, rep info and the tree info. These
1099 -- are delayed till now, since it is perfectly possible for gigi to
1100 -- generate errors, modify the tree (in particular by setting flags
1101 -- indicating that elaboration is required, and also to back annotate
1102 -- representation information for List_Rep_Info.
1104 Errout.Finalize (Last_Call => True);
1105 Errout.Output_Messages;
1108 -- Only write the library if the backend did not generate any error
1109 -- messages. Otherwise signal errors to the driver program so that
1110 -- there will be no attempt to generate an object file.
1112 if Compilation_Errors then
1114 Exit_Program (E_Errors);
1117 Write_ALI (Object => (Back_End_Mode = Generate_Object));
1119 if not Compilation_Errors then
1121 -- In case of ada backends, we need to make sure that the generated
1122 -- object file has a timestamp greater than the ALI file. We do this
1123 -- to make gnatmake happy when checking the ALI and obj timestamps,
1124 -- where it expects the object file being written after the ali file.
1126 -- Gnatmake's assumption is true for gcc platforms where the gcc
1127 -- wrapper needs to call the assembler after calling gnat1, but is
1128 -- not true for ada backends, where the object files are created
1129 -- directly by gnat1 (so are created before the ali file).
1131 Back_End.Gen_Or_Update_Object_File;
1134 -- Generate ASIS tree after writing the ALI file, since in ASIS mode,
1135 -- Write_ALI may in fact result in further tree decoration from the
1136 -- original tree file. Note that we dump the tree just before generating
1137 -- it, so that the dump will exactly reflect what is written out.
1142 -- Finalize name table and we are all done
1147 -- Handle fatal internal compiler errors
1149 when Rtsfind.RE_Not_Available =>
1150 Comperr.Compiler_Abort ("RE_Not_Available");
1152 when System.Assertions.Assert_Failure =>
1153 Comperr.Compiler_Abort ("Assert_Failure");
1155 when Constraint_Error =>
1156 Comperr.Compiler_Abort ("Constraint_Error");
1158 when Program_Error =>
1159 Comperr.Compiler_Abort ("Program_Error");
1161 when Storage_Error =>
1163 -- Assume this is a bug. If it is real, the message will in any case
1164 -- say Storage_Error, giving a strong hint!
1166 Comperr.Compiler_Abort ("Storage_Error");
1172 -- The outer exception handles an unrecoverable error
1175 when Unrecoverable_Error =>
1176 Errout.Finalize (Last_Call => True);
1177 Errout.Output_Messages;
1180 Write_Str ("compilation abandoned");
1183 Set_Standard_Output;
1186 Exit_Program (E_Errors);