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 -- Set strict standard interpretation of compiler permissions
397 if Debug_Flag_Dot_DD then
398 Strict_Alfa_Mode := True;
401 -- Turn off inlining, which would confuse formal verification output
404 Front_End_Inlining := False;
405 Inline_Active := False;
407 -- Disable front-end optimizations, to keep the tree as close to the
408 -- source code as possible, and also to avoid inconsistencies between
409 -- trees when using different optimization switches.
411 Optimization_Level := 0;
413 -- Enable some restrictions systematically to simplify the generated
414 -- code (and ease analysis). Note that restriction checks are also
415 -- disabled in Alfa mode, see Restrict.Check_Restriction, and user
416 -- specified Restrictions pragmas are ignored, see
417 -- Sem_Prag.Process_Restrictions_Or_Restriction_Warnings.
419 Restrict.Restrictions.Set (No_Initialize_Scalars) := True;
421 -- Suppress all language checks since they are handled implicitly by
422 -- the formal verification backend.
423 -- Turn off dynamic elaboration checks.
424 -- Turn off alignment checks.
425 -- Turn off validity checking.
427 Suppress_Options := (others => True);
428 Enable_Overflow_Checks := False;
429 Dynamic_Elaboration_Checks := False;
430 Reset_Validity_Check_Options;
432 -- Kill debug of generated code, since it messes up sloc values
434 Debug_Generated_Code := False;
436 -- Turn cross-referencing on in case it was disabled (e.g. by -gnatD)
437 -- as it is needed for computing effects of subprograms in the formal
438 -- verification backend.
442 -- Polling mode forced off, since it generates confusing junk
444 Polling_Required := False;
446 -- Set operating mode to Generate_Code, but full front-end expansion
447 -- is not desirable in Alfa mode, so a light expansion is performed
450 Operating_Mode := Generate_Code;
454 Debug_Flag_HH := True;
456 -- Disable Expressions_With_Actions nodes
458 -- The gnat2why backend does not deal with Expressions_With_Actions
459 -- in all places (in particular assertions). It is difficult to
460 -- determine in the frontend which cases are allowed, so we disable
461 -- Expressions_With_Actions entirely. Even in the cases where
462 -- gnat2why deals with Expressions_With_Actions, it is easier to
463 -- deal with the original constructs (quantified, conditional and
464 -- case expressions) instead of the rewritten ones.
466 Use_Expression_With_Actions := False;
468 -- Enable assertions and debug pragmas, since they give valuable
469 -- extra information for formal verification.
471 Assertions_Enabled := True;
472 Debug_Pragmas_Enabled := True;
474 -- Turn off style check options since we are not interested in any
475 -- front-end warnings when we are getting Alfa output.
477 Reset_Style_Check_Options;
479 -- Suppress compiler warnings, since what we are interested in here
480 -- is what formal verification can find out.
482 Warning_Mode := Suppress;
484 -- Suppress the generation of name tables for enumerations, which are
485 -- not needed for formal verification, and fall outside the Alfa
486 -- subset (use of pointers).
488 Global_Discard_Names := True;
490 -- Suppress the expansion of tagged types and dispatching calls,
491 -- which lead to the generation of non-Alfa code (use of pointers),
492 -- which is more complex to formally verify than the original source.
494 Tagged_Type_Expansion := False;
496 end Adjust_Global_Switches;
502 procedure Check_Bad_Body is
503 Sname : Unit_Name_Type;
504 Src_Ind : Source_File_Index;
505 Fname : File_Name_Type;
507 procedure Bad_Body_Error (Msg : String);
508 -- Issue message for bad body found
514 procedure Bad_Body_Error (Msg : String) is
516 Error_Msg_N (Msg, Main_Unit_Node);
517 Error_Msg_File_1 := Fname;
518 Error_Msg_N ("remove incorrect body in file{!", Main_Unit_Node);
521 -- Start of processing for Check_Bad_Body
524 -- Nothing to do if we are only checking syntax, because we don't know
525 -- enough to know if we require or forbid a body in this case.
527 if Operating_Mode = Check_Syntax then
531 -- Check for body not allowed
533 if (Main_Kind = N_Package_Declaration
534 and then not Body_Required (Main_Unit_Node))
535 or else (Main_Kind = N_Generic_Package_Declaration
536 and then not Body_Required (Main_Unit_Node))
537 or else Main_Kind = N_Package_Renaming_Declaration
538 or else Main_Kind = N_Subprogram_Renaming_Declaration
539 or else Nkind (Original_Node (Unit (Main_Unit_Node)))
540 in N_Generic_Instantiation
542 Sname := Unit_Name (Main_Unit);
544 -- If we do not already have a body name, then get the body name
545 -- (but how can we have a body name here???)
547 if not Is_Body_Name (Sname) then
548 Sname := Get_Body_Name (Sname);
551 Fname := Get_File_Name (Sname, Subunit => False);
552 Src_Ind := Load_Source_File (Fname);
554 -- Case where body is present and it is not a subunit. Exclude the
555 -- subunit case, because it has nothing to do with the package we are
556 -- compiling. It is illegal for a child unit and a subunit with the
557 -- same expanded name (RM 10.2(9)) to appear together in a partition,
558 -- but there is nothing to stop a compilation environment from having
559 -- both, and the test here simply allows that. If there is an attempt
560 -- to include both in a partition, this is diagnosed at bind time. In
561 -- Ada 83 mode this is not a warning case.
563 -- Note: if weird file names are being used, we can have a situation
564 -- where the file name that supposedly contains body in fact contains
565 -- a spec, or we can't tell what it contains. Skip the error message
568 -- Also ignore body that is nothing but pragma No_Body; (that's the
569 -- whole point of this pragma, to be used this way and to cause the
570 -- body file to be ignored in this context).
572 if Src_Ind /= No_Source_File
573 and then Get_Expected_Unit_Type (Fname) = Expect_Body
574 and then not Source_File_Is_Subunit (Src_Ind)
575 and then not Source_File_Is_No_Body (Src_Ind)
577 Errout.Finalize (Last_Call => False);
579 Error_Msg_Unit_1 := Sname;
581 -- Ada 83 case of a package body being ignored. This is not an
582 -- error as far as the Ada 83 RM is concerned, but it is almost
583 -- certainly not what is wanted so output a warning. Give this
584 -- message only if there were no errors, since otherwise it may
585 -- be incorrect (we may have misinterpreted a junk spec as not
586 -- needing a body when it really does).
588 if Main_Kind = N_Package_Declaration
589 and then Ada_Version = Ada_83
590 and then Operating_Mode = Generate_Code
591 and then Distribution_Stub_Mode /= Generate_Caller_Stub_Body
592 and then not Compilation_Errors
595 ("package $$ does not require a body?", Main_Unit_Node);
596 Error_Msg_File_1 := Fname;
597 Error_Msg_N ("body in file{? will be ignored", Main_Unit_Node);
599 -- Ada 95 cases of a body file present when no body is
600 -- permitted. This we consider to be an error.
603 -- For generic instantiations, we never allow a body
605 if Nkind (Original_Node (Unit (Main_Unit_Node)))
606 in N_Generic_Instantiation
609 ("generic instantiation for $$ does not allow a body");
611 -- A library unit that is a renaming never allows a body
613 elsif Main_Kind in N_Renaming_Declaration then
615 ("renaming declaration for $$ does not allow a body!");
617 -- Remaining cases are packages and generic packages. Here
618 -- we only do the test if there are no previous errors,
619 -- because if there are errors, they may lead us to
620 -- incorrectly believe that a package does not allow a body
621 -- when in fact it does.
623 elsif not Compilation_Errors then
624 if Main_Kind = N_Package_Declaration then
626 ("package $$ does not allow a body!");
628 elsif Main_Kind = N_Generic_Package_Declaration then
630 ("generic package $$ does not allow a body!");
639 -------------------------
640 -- Check_Library_Items --
641 -------------------------
643 -- Walk_Library_Items has plenty of assertions, so all we need to do is
644 -- call it, just for these assertions, not actually doing anything else.
646 procedure Check_Library_Items is
648 procedure Action (Item : Node_Id);
649 -- Action passed to Walk_Library_Items to do nothing
655 procedure Action (Item : Node_Id) is
660 procedure Walk is new Sem.Walk_Library_Items (Action);
662 -- Start of processing for Check_Library_Items
666 end Check_Library_Items;
672 procedure Check_Rep_Info is
674 if List_Representation_Info /= 0
675 or else List_Representation_Info_Mechanisms
680 ("cannot generate representation information, no code generated");
687 -- Start of processing for Gnat1drv
690 -- This inner block is set up to catch assertion errors and constraint
691 -- errors. Since the code for handling these errors can cause another
692 -- exception to be raised (namely Unrecoverable_Error), we need two
693 -- nested blocks, so that the outer one handles unrecoverable error.
696 -- Initialize all packages. For the most part, these initialization
697 -- calls can be made in any order. Exceptions are as follows:
699 -- Lib.Initialize need to be called before Scan_Compiler_Arguments,
700 -- because it initializes a table filled by Scan_Compiler_Arguments.
706 Scan_Compiler_Arguments;
707 Osint.Add_Default_Search_Dirs;
727 Sem_Type.Init_Interp_Tables;
729 -- Acquire target parameters from system.ads (source of package System)
734 S : Source_File_Index;
738 Name_Buffer (1 .. 10) := "system.ads";
741 S := Load_Source_File (N);
743 if S = No_Source_File then
745 ("fatal error, run-time library not installed correctly");
746 Write_Line ("cannot locate file system.ads");
747 raise Unrecoverable_Error;
749 -- Remember source index of system.ads (which was read successfully)
752 System_Source_File_Index := S;
755 Targparm.Get_Target_Parameters
756 (System_Text => Source_Text (S),
757 Source_First => Source_First (S),
758 Source_Last => Source_Last (S));
760 -- Acquire configuration pragma information from Targparm
762 Restrict.Restrictions := Targparm.Restrictions_On_Target;
765 Adjust_Global_Switches;
767 -- Output copyright notice if full list mode unless we have a list
768 -- file, in which case we defer this so that it is output in the file
770 if (Verbose_Mode or else (Full_List and then Full_List_File_Name = null))
771 and then not Debug_Flag_7
775 Write_Str (Gnat_Version_String);
777 Write_Str ("Copyright 1992-" & Current_Year
778 & ", Free Software Foundation, Inc.");
782 -- Check we do not have more than one source file, this happens only in
783 -- the case where the driver is called directly, it cannot happen when
784 -- gnat1 is invoked from gcc in the normal case.
786 if Osint.Number_Of_Files /= 1 then
789 Osint.Fail ("you must provide one source file");
791 elsif Usage_Requested then
795 Original_Operating_Mode := Operating_Mode;
798 -- Exit with errors if the main source could not be parsed. Also, when
799 -- -gnatd.H is present, the source file is not set.
801 if Sinput.Main_Source_File = No_Source_File then
803 -- Handle -gnatd.H debug mode
805 if Debug_Flag_Dot_HH then
807 -- For -gnatd.H, lock all the tables to keep the convention that
808 -- the backend needs to unlock the tables it wants to touch.
821 -- And all we need to do is to call the back end
823 Back_End.Call_Back_End (Back_End.Generate_Object);
826 Errout.Finalize (Last_Call => True);
827 Errout.Output_Messages;
828 Exit_Program (E_Errors);
831 Main_Unit_Node := Cunit (Main_Unit);
832 Main_Kind := Nkind (Unit (Main_Unit_Node));
835 -- Exit if compilation errors detected
837 Errout.Finalize (Last_Call => False);
839 if Compilation_Errors then
841 Sem_Ch13.Validate_Unchecked_Conversions;
842 Sem_Ch13.Validate_Address_Clauses;
843 Sem_Ch13.Validate_Independence;
844 Errout.Output_Messages;
847 -- Generate ALI file if specially requested
849 if Opt.Force_ALI_Tree_File then
850 Write_ALI (Object => False);
854 -- In CodePeer mode we delete SCIL files if there is an error
856 if CodePeer_Mode then
857 Comperr.Delete_SCIL_Files;
860 Errout.Finalize (Last_Call => True);
861 Exit_Program (E_Errors);
864 -- Set Generate_Code on main unit and its spec. We do this even if are
865 -- not generating code, since Lib-Writ uses this to determine which
866 -- units get written in the ali file.
868 Set_Generate_Code (Main_Unit);
870 -- If we have a corresponding spec, and it comes from source or it is
871 -- not a generated spec for a child subprogram body, then we need object
872 -- code for the spec unit as well.
874 if Nkind (Unit (Main_Unit_Node)) in N_Unit_Body
875 and then not Acts_As_Spec (Main_Unit_Node)
877 if Nkind (Unit (Main_Unit_Node)) = N_Subprogram_Body
878 and then not Comes_From_Source (Library_Unit (Main_Unit_Node))
883 (Get_Cunit_Unit_Number (Library_Unit (Main_Unit_Node)));
887 -- Case of no code required to be generated, exit indicating no error
889 if Original_Operating_Mode = Check_Syntax then
891 Errout.Finalize (Last_Call => True);
892 Errout.Output_Messages;
897 -- Use a goto instead of calling Exit_Program so that finalization
902 elsif Original_Operating_Mode = Check_Semantics then
903 Back_End_Mode := Declarations_Only;
905 -- All remaining cases are cases in which the user requested that code
906 -- be generated (i.e. no -gnatc or -gnats switch was used). Check if we
907 -- can in fact satisfy this request.
909 -- Cannot generate code if someone has turned off code generation for
910 -- any reason at all. We will try to figure out a reason below.
912 elsif Operating_Mode /= Generate_Code then
913 Back_End_Mode := Skip;
915 -- We can generate code for a subprogram body unless there were missing
916 -- subunits. Note that we always generate code for all generic units (a
917 -- change from some previous versions of GNAT).
919 elsif Main_Kind = N_Subprogram_Body and then not Subunits_Missing then
920 Back_End_Mode := Generate_Object;
922 -- We can generate code for a package body unless there are subunits
923 -- missing (note that we always generate code for generic units, which
924 -- is a change from some earlier versions of GNAT).
926 elsif Main_Kind = N_Package_Body and then not Subunits_Missing then
927 Back_End_Mode := Generate_Object;
929 -- We can generate code for a package declaration or a subprogram
930 -- declaration only if it does not required a body.
932 elsif Nkind_In (Main_Kind,
933 N_Package_Declaration,
934 N_Subprogram_Declaration)
936 (not Body_Required (Main_Unit_Node)
938 Distribution_Stub_Mode = Generate_Caller_Stub_Body)
940 Back_End_Mode := Generate_Object;
942 -- We can generate code for a generic package declaration of a generic
943 -- subprogram declaration only if does not require a body.
945 elsif Nkind_In (Main_Kind, N_Generic_Package_Declaration,
946 N_Generic_Subprogram_Declaration)
947 and then not Body_Required (Main_Unit_Node)
949 Back_End_Mode := Generate_Object;
951 -- Compilation units that are renamings do not require bodies, so we can
952 -- generate code for them.
954 elsif Nkind_In (Main_Kind, N_Package_Renaming_Declaration,
955 N_Subprogram_Renaming_Declaration)
957 Back_End_Mode := Generate_Object;
959 -- Compilation units that are generic renamings do not require bodies
960 -- so we can generate code for them.
962 elsif Main_Kind in N_Generic_Renaming_Declaration then
963 Back_End_Mode := Generate_Object;
965 -- It's not an error to generate SCIL for e.g. a spec which has a body
967 elsif CodePeer_Mode then
968 Back_End_Mode := Generate_Object;
970 -- In all other cases (specs which have bodies, generics, and bodies
971 -- where subunits are missing), we cannot generate code and we generate
972 -- a warning message. Note that generic instantiations are gone at this
973 -- stage since they have been replaced by their instances.
976 Back_End_Mode := Skip;
979 -- At this stage Back_End_Mode is set to indicate if the backend should
980 -- be called to generate code. If it is Skip, then code generation has
981 -- been turned off, even though code was requested by the original
982 -- command. This is not an error from the user point of view, but it is
983 -- an error from the point of view of the gcc driver, so we must exit
984 -- with an error status.
986 -- We generate an informative message (from the gcc point of view, it
987 -- is an error message, but from the users point of view this is not an
988 -- error, just a consequence of compiling something that cannot
991 if Back_End_Mode = Skip then
993 Write_Str ("cannot generate code for ");
995 Write_Name (Unit_File_Name (Main_Unit));
997 if Subunits_Missing then
998 Write_Str (" (missing subunits)");
1001 -- Force generation of ALI file, for backward compatibility
1003 Opt.Force_ALI_Tree_File := True;
1005 elsif Main_Kind = N_Subunit then
1006 Write_Str (" (subunit)");
1009 -- Force generation of ALI file, for backward compatibility
1011 Opt.Force_ALI_Tree_File := True;
1013 elsif Main_Kind = N_Subprogram_Declaration then
1014 Write_Str (" (subprogram spec)");
1017 -- Generic package body in GNAT implementation mode
1019 elsif Main_Kind = N_Package_Body and then GNAT_Mode then
1020 Write_Str (" (predefined generic)");
1023 -- Force generation of ALI file, for backward compatibility
1025 Opt.Force_ALI_Tree_File := True;
1027 -- Only other case is a package spec
1030 Write_Str (" (package spec)");
1034 Set_Standard_Output;
1036 Sem_Ch13.Validate_Unchecked_Conversions;
1037 Sem_Ch13.Validate_Address_Clauses;
1038 Sem_Ch13.Validate_Independence;
1039 Errout.Finalize (Last_Call => True);
1040 Errout.Output_Messages;
1044 -- Generate ALI file if specially requested, or for missing subunits,
1045 -- subunits or predefined generic.
1047 if Opt.Force_ALI_Tree_File then
1048 Write_ALI (Object => False);
1054 -- Exit program with error indication, to kill object file
1056 Exit_Program (E_No_Code);
1059 -- In -gnatc mode, we only do annotation if -gnatt or -gnatR is also set
1060 -- as indicated by Back_Annotate_Rep_Info being set to True.
1062 -- We don't call for annotations on a subunit, because to process those
1063 -- the back-end requires that the parent(s) be properly compiled.
1065 -- Annotation is suppressed for targets where front-end layout is
1066 -- enabled, because the front end determines representations.
1068 -- Annotation is also suppressed in the case of compiling for a VM,
1069 -- since representations are largely symbolic there.
1071 if Back_End_Mode = Declarations_Only
1072 and then (not (Back_Annotate_Rep_Info or Generate_SCIL)
1073 or else Main_Kind = N_Subunit
1074 or else Targparm.Frontend_Layout_On_Target
1075 or else Targparm.VM_Target /= No_VM)
1077 Sem_Ch13.Validate_Unchecked_Conversions;
1078 Sem_Ch13.Validate_Address_Clauses;
1079 Sem_Ch13.Validate_Independence;
1080 Errout.Finalize (Last_Call => True);
1081 Errout.Output_Messages;
1082 Write_ALI (Object => False);
1090 -- Ensure that we properly register a dependency on system.ads, since
1091 -- even if we do not semantically depend on this, Targparm has read
1092 -- system parameters from the system.ads file.
1094 Lib.Writ.Ensure_System_Dependency;
1096 -- Add dependencies, if any, on preprocessing data file and on
1097 -- preprocessing definition file(s).
1099 Prepcomp.Add_Dependencies;
1101 -- Back end needs to explicitly unlock tables it needs to touch
1114 -- ???Check_Library_Items under control of a debug flag, because it
1115 -- currently does not work if the -gnatn switch (back end inlining) is
1118 if Debug_Flag_Dot_WW then
1119 Check_Library_Items;
1122 -- Here we call the back end to generate the output code
1124 Generating_Code := True;
1125 Back_End.Call_Back_End (Back_End_Mode);
1127 -- Once the backend is complete, we unlock the names table. This call
1128 -- allows a few extra entries, needed for example for the file name for
1129 -- the library file output.
1133 -- Generate the call-graph output of dispatching calls
1135 Exp_CG.Generate_CG_Output;
1137 -- Validate unchecked conversions (using the values for size and
1138 -- alignment annotated by the backend where possible).
1140 Sem_Ch13.Validate_Unchecked_Conversions;
1142 -- Validate address clauses (again using alignment values annotated
1143 -- by the backend where possible).
1145 Sem_Ch13.Validate_Address_Clauses;
1147 -- Validate independence pragmas (again using values annotated by
1148 -- the back end for component layout etc.)
1150 Sem_Ch13.Validate_Independence;
1152 -- Now we complete output of errors, rep info and the tree info. These
1153 -- are delayed till now, since it is perfectly possible for gigi to
1154 -- generate errors, modify the tree (in particular by setting flags
1155 -- indicating that elaboration is required, and also to back annotate
1156 -- representation information for List_Rep_Info.
1158 Errout.Finalize (Last_Call => True);
1159 Errout.Output_Messages;
1162 -- Only write the library if the backend did not generate any error
1163 -- messages. Otherwise signal errors to the driver program so that
1164 -- there will be no attempt to generate an object file.
1166 if Compilation_Errors then
1168 Exit_Program (E_Errors);
1171 Write_ALI (Object => (Back_End_Mode = Generate_Object));
1173 if not Compilation_Errors then
1175 -- In case of ada backends, we need to make sure that the generated
1176 -- object file has a timestamp greater than the ALI file. We do this
1177 -- to make gnatmake happy when checking the ALI and obj timestamps,
1178 -- where it expects the object file being written after the ali file.
1180 -- Gnatmake's assumption is true for gcc platforms where the gcc
1181 -- wrapper needs to call the assembler after calling gnat1, but is
1182 -- not true for ada backends, where the object files are created
1183 -- directly by gnat1 (so are created before the ali file).
1185 Back_End.Gen_Or_Update_Object_File;
1188 -- Generate ASIS tree after writing the ALI file, since in ASIS mode,
1189 -- Write_ALI may in fact result in further tree decoration from the
1190 -- original tree file. Note that we dump the tree just before generating
1191 -- it, so that the dump will exactly reflect what is written out.
1196 -- Finalize name table and we are all done
1201 -- Handle fatal internal compiler errors
1203 when Rtsfind.RE_Not_Available =>
1204 Comperr.Compiler_Abort ("RE_Not_Available");
1206 when System.Assertions.Assert_Failure =>
1207 Comperr.Compiler_Abort ("Assert_Failure");
1209 when Constraint_Error =>
1210 Comperr.Compiler_Abort ("Constraint_Error");
1212 when Program_Error =>
1213 Comperr.Compiler_Abort ("Program_Error");
1215 when Storage_Error =>
1217 -- Assume this is a bug. If it is real, the message will in any case
1218 -- say Storage_Error, giving a strong hint!
1220 Comperr.Compiler_Abort ("Storage_Error");
1226 -- The outer exception handles an unrecoverable error
1229 when Unrecoverable_Error =>
1230 Errout.Finalize (Last_Call => True);
1231 Errout.Output_Messages;
1234 Write_Str ("compilation abandoned");
1237 Set_Standard_Output;
1240 Exit_Program (E_Errors);