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 Exception_Mechanism := Back_End_Exceptions;
330 -- Set proper status for overflow checks. We turn on overflow checks if
331 -- -gnatp was not specified, and either -gnato is set or the back-end
332 -- takes care of overflow checks. Otherwise we suppress overflow checks
333 -- by default (since front end checks are expensive).
335 if not Opt.Suppress_Checks
336 and then (Opt.Enable_Overflow_Checks
338 (Targparm.Backend_Divide_Checks_On_Target
340 Targparm.Backend_Overflow_Checks_On_Target))
342 Suppress_Options (Overflow_Check) := False;
344 Suppress_Options (Overflow_Check) := True;
347 -- Set switch indicating if we can use N_Expression_With_Actions
349 -- Debug flag -gnatd.X decisively sets usage on
351 if Debug_Flag_Dot_XX then
352 Use_Expression_With_Actions := True;
354 -- Debug flag -gnatd.Y decisively sets usage off
356 elsif Debug_Flag_Dot_YY then
357 Use_Expression_With_Actions := False;
359 -- Otherwise this feature is implemented, so we allow its use
362 Use_Expression_With_Actions := True;
365 -- Set switch indicating if back end can handle limited types, and
366 -- guarantee that no incorrect copies are made (e.g. in the context
367 -- of a conditional expression).
369 -- Debug flag -gnatd.L decisively sets usage on
371 if Debug_Flag_Dot_LL then
372 Back_End_Handles_Limited_Types := True;
374 -- If no debug flag, usage off for AAMP, VM, SCIL cases
377 or else VM_Target /= No_VM
378 or else Generate_SCIL
380 Back_End_Handles_Limited_Types := False;
382 -- Otherwise normal gcc back end, for now still turn flag off by
383 -- default, since there are unresolved problems in the front end.
386 Back_End_Handles_Limited_Types := False;
389 -- Set switches for formal verification mode
391 if Debug_Flag_Dot_FF then
395 -- Turn off inlining, which would confuse formal verification output
398 Front_End_Inlining := False;
399 Inline_Active := False;
401 -- Disable front-end optimizations, to keep the tree as close to the
402 -- source code as possible, and also to avoid inconsistencies between
403 -- trees when using different optimization switches.
405 Optimization_Level := 0;
407 -- Enable some restrictions systematically to simplify the generated
408 -- code (and ease analysis). Note that restriction checks are also
409 -- disabled in Alfa mode, see Restrict.Check_Restriction, and user
410 -- specified Restrictions pragmas are ignored, see
411 -- Sem_Prag.Process_Restrictions_Or_Restriction_Warnings.
413 Restrict.Restrictions.Set (No_Initialize_Scalars) := True;
415 -- Suppress all language checks since they are handled implicitly by
416 -- the formal verification backend.
417 -- Turn off dynamic elaboration checks.
418 -- Turn off alignment checks.
419 -- Turn off validity checking.
421 Suppress_Options := (others => True);
422 Enable_Overflow_Checks := False;
423 Dynamic_Elaboration_Checks := False;
424 Reset_Validity_Check_Options;
426 -- Kill debug of generated code, since it messes up sloc values
428 Debug_Generated_Code := False;
430 -- Turn cross-referencing on in case it was disabled (e.g. by -gnatD)
434 -- Polling mode forced off, since it generates confusing junk
436 Polling_Required := False;
438 -- Set operating mode to Generate_Code, but full front-end expansion
439 -- is not desirable in Alfa mode, so a light expansion is performed
442 Operating_Mode := Generate_Code;
446 Debug_Flag_HH := True;
448 -- Disable Expressions_With_Actions nodes
450 -- The gnat2why backend does not deal with Expressions_With_Actions
451 -- in all places (in particular assertions). It is difficult to
452 -- determine in the frontend which cases are allowed, so we disable
453 -- Expressions_With_Actions entirely. Even in the cases where
454 -- gnat2why deals with Expressions_With_Actions, it is easier to
455 -- deal with the original constructs (quantified, conditional and
456 -- case expressions) instead of the rewritten ones.
458 Use_Expression_With_Actions := False;
460 -- Enable assertions and debug pragmas, since they give valuable
461 -- extra information for formal verification.
463 Assertions_Enabled := True;
464 Debug_Pragmas_Enabled := True;
466 -- Turn off style check options since we are not interested in any
467 -- front-end warnings when we are getting Alfa output.
469 Reset_Style_Check_Options;
471 -- Suppress compiler warnings, since what we are interested in here
472 -- is what formal verification can find out.
474 Warning_Mode := Suppress;
476 -- Suppress the generation of name tables for enumerations
478 Global_Discard_Names := True;
480 -- We would prefer to suppress the expansion of tagged types and
481 -- dispatching calls, so that one day GNATprove can handle them
482 -- directly. Unfortunately, this is causing problems in some cases,
483 -- so keep this expansion for the time being. To be investigated ???
485 Tagged_Type_Expansion := True;
487 end Adjust_Global_Switches;
493 procedure Check_Bad_Body is
494 Sname : Unit_Name_Type;
495 Src_Ind : Source_File_Index;
496 Fname : File_Name_Type;
498 procedure Bad_Body_Error (Msg : String);
499 -- Issue message for bad body found
505 procedure Bad_Body_Error (Msg : String) is
507 Error_Msg_N (Msg, Main_Unit_Node);
508 Error_Msg_File_1 := Fname;
509 Error_Msg_N ("remove incorrect body in file{!", Main_Unit_Node);
512 -- Start of processing for Check_Bad_Body
515 -- Nothing to do if we are only checking syntax, because we don't know
516 -- enough to know if we require or forbid a body in this case.
518 if Operating_Mode = Check_Syntax then
522 -- Check for body not allowed
524 if (Main_Kind = N_Package_Declaration
525 and then not Body_Required (Main_Unit_Node))
526 or else (Main_Kind = N_Generic_Package_Declaration
527 and then not Body_Required (Main_Unit_Node))
528 or else Main_Kind = N_Package_Renaming_Declaration
529 or else Main_Kind = N_Subprogram_Renaming_Declaration
530 or else Nkind (Original_Node (Unit (Main_Unit_Node)))
531 in N_Generic_Instantiation
533 Sname := Unit_Name (Main_Unit);
535 -- If we do not already have a body name, then get the body name
536 -- (but how can we have a body name here???)
538 if not Is_Body_Name (Sname) then
539 Sname := Get_Body_Name (Sname);
542 Fname := Get_File_Name (Sname, Subunit => False);
543 Src_Ind := Load_Source_File (Fname);
545 -- Case where body is present and it is not a subunit. Exclude the
546 -- subunit case, because it has nothing to do with the package we are
547 -- compiling. It is illegal for a child unit and a subunit with the
548 -- same expanded name (RM 10.2(9)) to appear together in a partition,
549 -- but there is nothing to stop a compilation environment from having
550 -- both, and the test here simply allows that. If there is an attempt
551 -- to include both in a partition, this is diagnosed at bind time. In
552 -- Ada 83 mode this is not a warning case.
554 -- Note: if weird file names are being used, we can have a situation
555 -- where the file name that supposedly contains body in fact contains
556 -- a spec, or we can't tell what it contains. Skip the error message
559 -- Also ignore body that is nothing but pragma No_Body; (that's the
560 -- whole point of this pragma, to be used this way and to cause the
561 -- body file to be ignored in this context).
563 if Src_Ind /= No_Source_File
564 and then Get_Expected_Unit_Type (Fname) = Expect_Body
565 and then not Source_File_Is_Subunit (Src_Ind)
566 and then not Source_File_Is_No_Body (Src_Ind)
568 Errout.Finalize (Last_Call => False);
570 Error_Msg_Unit_1 := Sname;
572 -- Ada 83 case of a package body being ignored. This is not an
573 -- error as far as the Ada 83 RM is concerned, but it is almost
574 -- certainly not what is wanted so output a warning. Give this
575 -- message only if there were no errors, since otherwise it may
576 -- be incorrect (we may have misinterpreted a junk spec as not
577 -- needing a body when it really does).
579 if Main_Kind = N_Package_Declaration
580 and then Ada_Version = Ada_83
581 and then Operating_Mode = Generate_Code
582 and then Distribution_Stub_Mode /= Generate_Caller_Stub_Body
583 and then not Compilation_Errors
586 ("package $$ does not require a body?", Main_Unit_Node);
587 Error_Msg_File_1 := Fname;
588 Error_Msg_N ("body in file{? will be ignored", Main_Unit_Node);
590 -- Ada 95 cases of a body file present when no body is
591 -- permitted. This we consider to be an error.
594 -- For generic instantiations, we never allow a body
596 if Nkind (Original_Node (Unit (Main_Unit_Node)))
597 in N_Generic_Instantiation
600 ("generic instantiation for $$ does not allow a body");
602 -- A library unit that is a renaming never allows a body
604 elsif Main_Kind in N_Renaming_Declaration then
606 ("renaming declaration for $$ does not allow a body!");
608 -- Remaining cases are packages and generic packages. Here
609 -- we only do the test if there are no previous errors,
610 -- because if there are errors, they may lead us to
611 -- incorrectly believe that a package does not allow a body
612 -- when in fact it does.
614 elsif not Compilation_Errors then
615 if Main_Kind = N_Package_Declaration then
617 ("package $$ does not allow a body!");
619 elsif Main_Kind = N_Generic_Package_Declaration then
621 ("generic package $$ does not allow a body!");
630 -------------------------
631 -- Check_Library_Items --
632 -------------------------
634 -- Walk_Library_Items has plenty of assertions, so all we need to do is
635 -- call it, just for these assertions, not actually doing anything else.
637 procedure Check_Library_Items is
639 procedure Action (Item : Node_Id);
640 -- Action passed to Walk_Library_Items to do nothing
646 procedure Action (Item : Node_Id) is
651 procedure Walk is new Sem.Walk_Library_Items (Action);
653 -- Start of processing for Check_Library_Items
657 end Check_Library_Items;
663 procedure Check_Rep_Info is
665 if List_Representation_Info /= 0
666 or else List_Representation_Info_Mechanisms
671 ("cannot generate representation information, no code generated");
678 -- Start of processing for Gnat1drv
681 -- This inner block is set up to catch assertion errors and constraint
682 -- errors. Since the code for handling these errors can cause another
683 -- exception to be raised (namely Unrecoverable_Error), we need two
684 -- nested blocks, so that the outer one handles unrecoverable error.
687 -- Initialize all packages. For the most part, these initialization
688 -- calls can be made in any order. Exceptions are as follows:
690 -- Lib.Initialize need to be called before Scan_Compiler_Arguments,
691 -- because it initializes a table filled by Scan_Compiler_Arguments.
697 Scan_Compiler_Arguments;
698 Osint.Add_Default_Search_Dirs;
718 Sem_Type.Init_Interp_Tables;
720 -- Acquire target parameters from system.ads (source of package System)
725 S : Source_File_Index;
729 Name_Buffer (1 .. 10) := "system.ads";
732 S := Load_Source_File (N);
734 if S = No_Source_File then
736 ("fatal error, run-time library not installed correctly");
737 Write_Line ("cannot locate file system.ads");
738 raise Unrecoverable_Error;
740 -- Remember source index of system.ads (which was read successfully)
743 System_Source_File_Index := S;
746 Targparm.Get_Target_Parameters
747 (System_Text => Source_Text (S),
748 Source_First => Source_First (S),
749 Source_Last => Source_Last (S));
751 -- Acquire configuration pragma information from Targparm
753 Restrict.Restrictions := Targparm.Restrictions_On_Target;
756 Adjust_Global_Switches;
758 -- Output copyright notice if full list mode unless we have a list
759 -- file, in which case we defer this so that it is output in the file
761 if (Verbose_Mode or else (Full_List and then Full_List_File_Name = null))
762 and then not Debug_Flag_7
766 Write_Str (Gnat_Version_String);
768 Write_Str ("Copyright 1992-" & Current_Year
769 & ", Free Software Foundation, Inc.");
773 -- Check we do not have more than one source file, this happens only in
774 -- the case where the driver is called directly, it cannot happen when
775 -- gnat1 is invoked from gcc in the normal case.
777 if Osint.Number_Of_Files /= 1 then
780 Osint.Fail ("you must provide one source file");
782 elsif Usage_Requested then
786 Original_Operating_Mode := Operating_Mode;
789 -- Exit with errors if the main source could not be parsed. Also, when
790 -- -gnatd.H is present, the source file is not set.
792 if Sinput.Main_Source_File = No_Source_File then
794 -- Handle -gnatd.H debug mode
796 if Debug_Flag_Dot_HH then
798 -- For -gnatd.H, lock all the tables to keep the convention that
799 -- the backend needs to unlock the tables it wants to touch.
812 -- And all we need to do is to call the back end
814 Back_End.Call_Back_End (Back_End.Generate_Object);
817 Errout.Finalize (Last_Call => True);
818 Errout.Output_Messages;
819 Exit_Program (E_Errors);
822 Main_Unit_Node := Cunit (Main_Unit);
823 Main_Kind := Nkind (Unit (Main_Unit_Node));
826 -- Exit if compilation errors detected
828 Errout.Finalize (Last_Call => False);
830 if Compilation_Errors then
832 Sem_Ch13.Validate_Unchecked_Conversions;
833 Sem_Ch13.Validate_Address_Clauses;
834 Sem_Ch13.Validate_Independence;
835 Errout.Output_Messages;
838 -- Generate ALI file if specially requested
840 if Opt.Force_ALI_Tree_File then
841 Write_ALI (Object => False);
845 if CodePeer_Mode then
846 Comperr.Delete_SCIL_Files;
849 Errout.Finalize (Last_Call => True);
850 Exit_Program (E_Errors);
853 -- Set Generate_Code on main unit and its spec. We do this even if are
854 -- not generating code, since Lib-Writ uses this to determine which
855 -- units get written in the ali file.
857 Set_Generate_Code (Main_Unit);
859 -- If we have a corresponding spec, and it comes from source or it is
860 -- not a generated spec for a child subprogram body, then we need object
861 -- code for the spec unit as well.
863 if Nkind (Unit (Main_Unit_Node)) in N_Unit_Body
864 and then not Acts_As_Spec (Main_Unit_Node)
866 if Nkind (Unit (Main_Unit_Node)) = N_Subprogram_Body
867 and then not Comes_From_Source (Library_Unit (Main_Unit_Node))
872 (Get_Cunit_Unit_Number (Library_Unit (Main_Unit_Node)));
876 -- Case of no code required to be generated, exit indicating no error
878 if Original_Operating_Mode = Check_Syntax then
880 Errout.Finalize (Last_Call => True);
881 Errout.Output_Messages;
886 -- Use a goto instead of calling Exit_Program so that finalization
891 elsif Original_Operating_Mode = Check_Semantics then
892 Back_End_Mode := Declarations_Only;
894 -- All remaining cases are cases in which the user requested that code
895 -- be generated (i.e. no -gnatc or -gnats switch was used). Check if we
896 -- can in fact satisfy this request.
898 -- Cannot generate code if someone has turned off code generation for
899 -- any reason at all. We will try to figure out a reason below.
901 elsif Operating_Mode /= Generate_Code then
902 Back_End_Mode := Skip;
904 -- We can generate code for a subprogram body unless there were missing
905 -- subunits. Note that we always generate code for all generic units (a
906 -- change from some previous versions of GNAT).
908 elsif Main_Kind = N_Subprogram_Body and then not Subunits_Missing then
909 Back_End_Mode := Generate_Object;
911 -- We can generate code for a package body unless there are subunits
912 -- missing (note that we always generate code for generic units, which
913 -- is a change from some earlier versions of GNAT).
915 elsif Main_Kind = N_Package_Body and then not Subunits_Missing then
916 Back_End_Mode := Generate_Object;
918 -- We can generate code for a package declaration or a subprogram
919 -- declaration only if it does not required a body.
921 elsif Nkind_In (Main_Kind,
922 N_Package_Declaration,
923 N_Subprogram_Declaration)
925 (not Body_Required (Main_Unit_Node)
927 Distribution_Stub_Mode = Generate_Caller_Stub_Body)
929 Back_End_Mode := Generate_Object;
931 -- We can generate code for a generic package declaration of a generic
932 -- subprogram declaration only if does not require a body.
934 elsif Nkind_In (Main_Kind, N_Generic_Package_Declaration,
935 N_Generic_Subprogram_Declaration)
936 and then not Body_Required (Main_Unit_Node)
938 Back_End_Mode := Generate_Object;
940 -- Compilation units that are renamings do not require bodies, so we can
941 -- generate code for them.
943 elsif Nkind_In (Main_Kind, N_Package_Renaming_Declaration,
944 N_Subprogram_Renaming_Declaration)
946 Back_End_Mode := Generate_Object;
948 -- Compilation units that are generic renamings do not require bodies
949 -- so we can generate code for them.
951 elsif Main_Kind in N_Generic_Renaming_Declaration then
952 Back_End_Mode := Generate_Object;
954 -- It's not an error to generate SCIL for e.g. a spec which has a body
956 elsif CodePeer_Mode then
957 Back_End_Mode := Generate_Object;
959 -- In all other cases (specs which have bodies, generics, and bodies
960 -- where subunits are missing), we cannot generate code and we generate
961 -- a warning message. Note that generic instantiations are gone at this
962 -- stage since they have been replaced by their instances.
965 Back_End_Mode := Skip;
968 -- At this stage Back_End_Mode is set to indicate if the backend should
969 -- be called to generate code. If it is Skip, then code generation has
970 -- been turned off, even though code was requested by the original
971 -- command. This is not an error from the user point of view, but it is
972 -- an error from the point of view of the gcc driver, so we must exit
973 -- with an error status.
975 -- We generate an informative message (from the gcc point of view, it
976 -- is an error message, but from the users point of view this is not an
977 -- error, just a consequence of compiling something that cannot
980 if Back_End_Mode = Skip then
982 Write_Str ("cannot generate code for ");
984 Write_Name (Unit_File_Name (Main_Unit));
986 if Subunits_Missing then
987 Write_Str (" (missing subunits)");
990 -- Force generation of ALI file, for backward compatibility
992 Opt.Force_ALI_Tree_File := True;
994 elsif Main_Kind = N_Subunit then
995 Write_Str (" (subunit)");
998 -- Force generation of ALI file, for backward compatibility
1000 Opt.Force_ALI_Tree_File := True;
1002 elsif Main_Kind = N_Subprogram_Declaration then
1003 Write_Str (" (subprogram spec)");
1006 -- Generic package body in GNAT implementation mode
1008 elsif Main_Kind = N_Package_Body and then GNAT_Mode then
1009 Write_Str (" (predefined generic)");
1012 -- Force generation of ALI file, for backward compatibility
1014 Opt.Force_ALI_Tree_File := True;
1016 -- Only other case is a package spec
1019 Write_Str (" (package spec)");
1023 Set_Standard_Output;
1025 Sem_Ch13.Validate_Unchecked_Conversions;
1026 Sem_Ch13.Validate_Address_Clauses;
1027 Sem_Ch13.Validate_Independence;
1028 Errout.Finalize (Last_Call => True);
1029 Errout.Output_Messages;
1033 -- Generate ALI file if specially requested, or for missing subunits,
1034 -- subunits or predefined generic.
1036 if Opt.Force_ALI_Tree_File then
1037 Write_ALI (Object => False);
1043 -- Exit program with error indication, to kill object file
1045 Exit_Program (E_No_Code);
1048 -- In -gnatc mode, we only do annotation if -gnatt or -gnatR is also set
1049 -- as indicated by Back_Annotate_Rep_Info being set to True.
1051 -- We don't call for annotations on a subunit, because to process those
1052 -- the back-end requires that the parent(s) be properly compiled.
1054 -- Annotation is suppressed for targets where front-end layout is
1055 -- enabled, because the front end determines representations.
1057 -- Annotation is also suppressed in the case of compiling for a VM,
1058 -- since representations are largely symbolic there.
1060 if Back_End_Mode = Declarations_Only
1061 and then (not (Back_Annotate_Rep_Info or Generate_SCIL)
1062 or else Main_Kind = N_Subunit
1063 or else Targparm.Frontend_Layout_On_Target
1064 or else Targparm.VM_Target /= No_VM)
1066 Sem_Ch13.Validate_Unchecked_Conversions;
1067 Sem_Ch13.Validate_Address_Clauses;
1068 Sem_Ch13.Validate_Independence;
1069 Errout.Finalize (Last_Call => True);
1070 Errout.Output_Messages;
1071 Write_ALI (Object => False);
1079 -- Ensure that we properly register a dependency on system.ads, since
1080 -- even if we do not semantically depend on this, Targparm has read
1081 -- system parameters from the system.ads file.
1083 Lib.Writ.Ensure_System_Dependency;
1085 -- Add dependencies, if any, on preprocessing data file and on
1086 -- preprocessing definition file(s).
1088 Prepcomp.Add_Dependencies;
1090 -- Back end needs to explicitly unlock tables it needs to touch
1103 -- ???Check_Library_Items under control of a debug flag, because it
1104 -- currently does not work if the -gnatn switch (back end inlining) is
1107 if Debug_Flag_Dot_WW then
1108 Check_Library_Items;
1111 -- Here we call the back end to generate the output code
1113 Generating_Code := True;
1114 Back_End.Call_Back_End (Back_End_Mode);
1116 -- Once the backend is complete, we unlock the names table. This call
1117 -- allows a few extra entries, needed for example for the file name for
1118 -- the library file output.
1122 -- Generate the call-graph output of dispatching calls
1124 Exp_CG.Generate_CG_Output;
1126 -- Validate unchecked conversions (using the values for size and
1127 -- alignment annotated by the backend where possible).
1129 Sem_Ch13.Validate_Unchecked_Conversions;
1131 -- Validate address clauses (again using alignment values annotated
1132 -- by the backend where possible).
1134 Sem_Ch13.Validate_Address_Clauses;
1136 -- Validate independence pragmas (again using values annotated by
1137 -- the back end for component layout etc.)
1139 Sem_Ch13.Validate_Independence;
1141 -- Now we complete output of errors, rep info and the tree info. These
1142 -- are delayed till now, since it is perfectly possible for gigi to
1143 -- generate errors, modify the tree (in particular by setting flags
1144 -- indicating that elaboration is required, and also to back annotate
1145 -- representation information for List_Rep_Info.
1147 Errout.Finalize (Last_Call => True);
1148 Errout.Output_Messages;
1151 -- Only write the library if the backend did not generate any error
1152 -- messages. Otherwise signal errors to the driver program so that
1153 -- there will be no attempt to generate an object file.
1155 if Compilation_Errors then
1157 Exit_Program (E_Errors);
1160 Write_ALI (Object => (Back_End_Mode = Generate_Object));
1162 if not Compilation_Errors then
1164 -- In case of ada backends, we need to make sure that the generated
1165 -- object file has a timestamp greater than the ALI file. We do this
1166 -- to make gnatmake happy when checking the ALI and obj timestamps,
1167 -- where it expects the object file being written after the ali file.
1169 -- Gnatmake's assumption is true for gcc platforms where the gcc
1170 -- wrapper needs to call the assembler after calling gnat1, but is
1171 -- not true for ada backends, where the object files are created
1172 -- directly by gnat1 (so are created before the ali file).
1174 Back_End.Gen_Or_Update_Object_File;
1177 -- Generate ASIS tree after writing the ALI file, since in ASIS mode,
1178 -- Write_ALI may in fact result in further tree decoration from the
1179 -- original tree file. Note that we dump the tree just before generating
1180 -- it, so that the dump will exactly reflect what is written out.
1185 -- Finalize name table and we are all done
1190 -- Handle fatal internal compiler errors
1192 when Rtsfind.RE_Not_Available =>
1193 Comperr.Compiler_Abort ("RE_Not_Available");
1195 when System.Assertions.Assert_Failure =>
1196 Comperr.Compiler_Abort ("Assert_Failure");
1198 when Constraint_Error =>
1199 Comperr.Compiler_Abort ("Constraint_Error");
1201 when Program_Error =>
1202 Comperr.Compiler_Abort ("Program_Error");
1204 when Storage_Error =>
1206 -- Assume this is a bug. If it is real, the message will in any case
1207 -- say Storage_Error, giving a strong hint!
1209 Comperr.Compiler_Abort ("Storage_Error");
1215 -- The outer exception handles an unrecoverable error
1218 when Unrecoverable_Error =>
1219 Errout.Finalize (Last_Call => True);
1220 Errout.Output_Messages;
1223 Write_Str ("compilation abandoned");
1226 Set_Standard_Output;
1229 Exit_Program (E_Errors);