1 ------------------------------------------------------------------------------
3 -- GNAT COMPILER COMPONENTS --
9 -- Copyright (C) 1992-2012, Free Software Foundation, Inc. --
11 -- GNAT is free software; you can redistribute it and/or modify it under --
12 -- terms of the GNU General Public License as published by the Free Soft- --
13 -- ware Foundation; either version 3, or (at your option) any later ver- --
14 -- sion. GNAT is distributed in the hope that it will be useful, but WITH- --
15 -- OUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY --
16 -- or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License --
17 -- for more details. You should have received a copy of the GNU General --
18 -- Public License distributed with GNAT; see file COPYING3. If not, go to --
19 -- http://www.gnu.org/licenses for a complete copy of the license. --
21 -- GNAT was originally developed by the GNAT team at New York University. --
22 -- Extensive contributions were provided by Ada Core Technologies Inc. --
24 ------------------------------------------------------------------------------
26 with Atree; use Atree;
27 with Back_End; use Back_End;
29 with Csets; use Csets;
30 with Debug; use Debug;
32 with Errout; use Errout;
34 with Exp_Ch6; use Exp_Ch6;
36 with Fname; use Fname;
37 with Fname.UF; use Fname.UF;
39 with Gnatvsn; use Gnatvsn;
43 with Lib.Writ; use Lib.Writ;
45 with Namet; use Namet;
48 with Osint; use Osint;
49 with Output; use Output;
52 with Repinfo; use Repinfo;
54 with Rident; use Rident;
64 with Sinfo; use Sinfo;
65 with Sinput.L; use Sinput.L;
67 with Sprint; use Sprint;
69 with Stylesw; use Stylesw;
70 with Targparm; use Targparm;
72 with Treepr; use Treepr;
74 with Types; use Types;
75 with Uintp; use Uintp;
76 with Uname; use Uname;
79 with Validsw; use Validsw;
81 with System.Assertions;
84 Main_Unit_Node : Node_Id;
85 -- Compilation unit node for main unit
87 Main_Kind : Node_Kind;
88 -- Kind of main compilation unit node
90 Back_End_Mode : Back_End.Back_End_Mode_Type;
91 -- Record back end mode
93 procedure Adjust_Global_Switches;
94 -- There are various interactions between front end switch settings,
95 -- including debug switch settings and target dependent parameters.
96 -- This procedure takes care of properly handling these interactions.
97 -- We do it after scanning out all the switches, so that we are not
98 -- depending on the order in which switches appear.
100 procedure Check_Bad_Body;
101 -- Called to check if the unit we are compiling has a bad body
103 procedure Check_Rep_Info;
104 -- Called when we are not generating code, to check if -gnatR was requested
105 -- and if so, explain that we will not be honoring the request.
107 ----------------------------
108 -- Adjust_Global_Switches --
109 ----------------------------
111 procedure Adjust_Global_Switches is
113 -- Debug flag -gnatd.I is a synonym for Generate_SCIL and requires code
116 if Debug_Flag_Dot_II and then Operating_Mode = Generate_Code then
117 Generate_SCIL := True;
120 -- Disable CodePeer_Mode in Check_Syntax, since we need front-end
123 if Operating_Mode = Check_Syntax then
124 CodePeer_Mode := False;
127 -- Set ASIS mode if -gnatt and -gnatc are set
129 if Operating_Mode = Check_Semantics and then Tree_Output then
132 -- Turn off inlining in ASIS mode, since ASIS cannot handle the extra
133 -- information in the trees caused by inlining being active.
135 -- More specifically, the tree seems to be malformed from the ASIS
136 -- point of view if -gnatc and -gnatn appear together???
138 Inline_Active := False;
140 -- Turn off SCIL generation and CodePeer mode in semantics mode,
141 -- since SCIL requires front-end expansion.
143 Generate_SCIL := False;
144 CodePeer_Mode := False;
147 -- SCIL mode needs to disable front-end inlining since the generated
148 -- trees (in particular order and consistency between specs compiled
149 -- as part of a main unit or as part of a with-clause) are causing
152 if Generate_SCIL then
153 Front_End_Inlining := False;
156 -- Tune settings for optimal SCIL generation in CodePeer mode
158 if CodePeer_Mode then
160 -- Turn off inlining, confuses CodePeer output and gains nothing
162 Front_End_Inlining := False;
163 Inline_Active := False;
165 -- Disable front-end optimizations, to keep the tree as close to the
166 -- source code as possible, and also to avoid inconsistencies between
167 -- trees when using different optimization switches.
169 Optimization_Level := 0;
171 -- Enable some restrictions systematically to simplify the generated
172 -- code (and ease analysis). Note that restriction checks are also
173 -- disabled in CodePeer mode, see Restrict.Check_Restriction, and
174 -- user specified Restrictions pragmas are ignored, see
175 -- Sem_Prag.Process_Restrictions_Or_Restriction_Warnings.
177 Restrict.Restrictions.Set (No_Initialize_Scalars) := True;
178 Restrict.Restrictions.Set (No_Task_Hierarchy) := True;
179 Restrict.Restrictions.Set (No_Abort_Statements) := True;
180 Restrict.Restrictions.Set (Max_Asynchronous_Select_Nesting) := True;
181 Restrict.Restrictions.Value (Max_Asynchronous_Select_Nesting) := 0;
183 -- Suppress division by zero and access checks since they are handled
184 -- implicitly by CodePeer.
186 -- Turn off dynamic elaboration checks: generates inconsistencies in
187 -- trees between specs compiled as part of a main unit or as part of
190 -- Turn off alignment checks: these cannot be proved statically by
191 -- CodePeer and generate false positives.
193 -- Enable all other language checks
195 Suppress_Options.Suppress :=
196 (Access_Check => True,
197 Alignment_Check => True,
198 Division_Check => True,
199 Elaboration_Check => True,
202 Dynamic_Elaboration_Checks := False;
204 -- Set STRICT mode for overflow checks if not set explicitly
206 if Suppress_Options.Overflow_Checks_General = Not_Set then
207 Suppress_Options.Overflow_Checks_General := Strict;
208 Suppress_Options.Overflow_Checks_Assertions := Strict;
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 -- Increase size of allocated entities if debug flag -gnatd.N is set
293 if Debug_Flag_Dot_NN then
294 Atree.Num_Extension_Nodes := Atree.Num_Extension_Nodes + 1;
297 -- Disable static allocation of dispatch tables if -gnatd.t or if layout
298 -- is enabled. The front end's layout phase currently treats types that
299 -- have discriminant-dependent arrays as not being static even when a
300 -- discriminant constraint on the type is static, and this leads to
301 -- problems with subtypes of type Ada.Tags.Dispatch_Table_Wrapper. ???
303 if Debug_Flag_Dot_T or else Frontend_Layout_On_Target then
304 Static_Dispatch_Tables := False;
307 -- Flip endian mode if -gnatd8 set
310 Ttypes.Bytes_Big_Endian := not Ttypes.Bytes_Big_Endian;
313 -- Deal with forcing OpenVMS switches True if debug flag M is set, but
314 -- record the setting of Targparm.Open_VMS_On_Target in True_VMS_Target
315 -- before doing this, so we know if we are in real OpenVMS or not!
317 Opt.True_VMS_Target := Targparm.OpenVMS_On_Target;
320 Targparm.OpenVMS_On_Target := True;
321 Hostparm.OpenVMS := True;
324 -- Activate front end layout if debug flag -gnatdF is set
326 if Debug_Flag_FF then
327 Targparm.Frontend_Layout_On_Target := True;
330 -- Set and check exception mechanism
332 if Targparm.ZCX_By_Default_On_Target then
333 Exception_Mechanism := Back_End_Exceptions;
336 -- Set proper status for overflow check mechanism
338 -- If already set (by -gnato or above in CodePeer mode) then we have
341 if Opt.Suppress_Options.Overflow_Checks_General /= Not_Set then
344 -- Otherwise set overflow mode defaults
347 -- Otherwise set overflow checks off by default
349 Suppress_Options.Suppress (Overflow_Check) := True;
351 -- Set appropriate default overflow handling mode. Note: at present
352 -- we set STRICT in all three of the following cases. They are
353 -- separated because in the future we may make different choices.
355 -- By default set STRICT mode if -gnatg in effect
358 Suppress_Options.Overflow_Checks_General := Strict;
359 Suppress_Options.Overflow_Checks_Assertions := Strict;
361 -- If we have backend divide and overflow checks, then by default
362 -- overflow checks are STRICT. Historically this code used to also
363 -- activate overflow checks, although no target currently has these
364 -- flags set, so this was dead code anyway.
366 elsif Targparm.Backend_Divide_Checks_On_Target
368 Targparm.Backend_Overflow_Checks_On_Target
370 Suppress_Options.Overflow_Checks_General := Strict;
371 Suppress_Options.Overflow_Checks_Assertions := Strict;
373 -- Otherwise for now, default is STRICT mode. This may change in the
374 -- future, but for now this is the compatible behavior with previous
378 Suppress_Options.Overflow_Checks_General := Strict;
379 Suppress_Options.Overflow_Checks_Assertions := Strict;
383 -- Set default for atomic synchronization. As this synchronization
384 -- between atomic accesses can be expensive, and not typically needed
385 -- on some targets, an optional target parameter can turn the option
386 -- off. Note Atomic Synchronization is implemented as check.
388 Suppress_Options.Suppress (Atomic_Synchronization) :=
389 not Atomic_Sync_Default;
391 -- Set switch indicating if we can use N_Expression_With_Actions
393 -- Debug flag -gnatd.X decisively sets usage on
395 if Debug_Flag_Dot_XX then
396 Use_Expression_With_Actions := True;
398 -- Debug flag -gnatd.Y decisively sets usage off
400 elsif Debug_Flag_Dot_YY then
401 Use_Expression_With_Actions := False;
403 -- Otherwise this feature is implemented, so we allow its use
406 Use_Expression_With_Actions := True;
409 -- Set switch indicating if back end can handle limited types, and
410 -- guarantee that no incorrect copies are made (e.g. in the context
411 -- of an if or case expression).
413 -- Debug flag -gnatd.L decisively sets usage on
415 if Debug_Flag_Dot_LL then
416 Back_End_Handles_Limited_Types := True;
418 -- If no debug flag, usage off for AAMP, VM, SCIL cases
421 or else VM_Target /= No_VM
422 or else Generate_SCIL
424 Back_End_Handles_Limited_Types := False;
426 -- Otherwise normal gcc back end, for now still turn flag off by
427 -- default, since there are unresolved problems in the front end.
430 Back_End_Handles_Limited_Types := False;
433 -- Set switches for formal verification mode
435 if Debug_Flag_Dot_VV then
436 Formal_Extensions := True;
439 if Debug_Flag_Dot_FF then
442 -- Set strict standard interpretation of compiler permissions
444 if Debug_Flag_Dot_DD then
445 Strict_Alfa_Mode := True;
448 -- Turn off inlining, which would confuse formal verification output
451 Front_End_Inlining := False;
452 Inline_Active := False;
454 -- Disable front-end optimizations, to keep the tree as close to the
455 -- source code as possible, and also to avoid inconsistencies between
456 -- trees when using different optimization switches.
458 Optimization_Level := 0;
460 -- Enable some restrictions systematically to simplify the generated
461 -- code (and ease analysis). Note that restriction checks are also
462 -- disabled in Alfa mode, see Restrict.Check_Restriction, and user
463 -- specified Restrictions pragmas are ignored, see
464 -- Sem_Prag.Process_Restrictions_Or_Restriction_Warnings.
466 Restrict.Restrictions.Set (No_Initialize_Scalars) := True;
468 -- Note: at this point we used to suppress various checks, but that
469 -- is not what we want. We need the semantic processing for these
470 -- checks (which will set flags like Do_Overflow_Check, showing the
471 -- points at which potential checks are required semantically). We
472 -- don't want the expansion associated with these checks, but that
473 -- happens anyway because this expansion is simply not done in the
474 -- Alfa version of the expander.
476 -- Kill debug of generated code, since it messes up sloc values
478 Debug_Generated_Code := False;
480 -- Turn cross-referencing on in case it was disabled (e.g. by -gnatD)
481 -- as it is needed for computing effects of subprograms in the formal
482 -- verification backend.
486 -- Polling mode forced off, since it generates confusing junk
488 Polling_Required := False;
490 -- Set operating mode to Generate_Code, but full front-end expansion
491 -- is not desirable in Alfa mode, so a light expansion is performed
494 Operating_Mode := Generate_Code;
498 Debug_Flag_HH := True;
500 -- Disable Expressions_With_Actions nodes
502 -- The gnat2why backend does not deal with Expressions_With_Actions
503 -- in all places (in particular assertions). It is difficult to
504 -- determine in the frontend which cases are allowed, so we disable
505 -- Expressions_With_Actions entirely. Even in the cases where
506 -- gnat2why deals with Expressions_With_Actions, it is easier to
507 -- deal with the original constructs (quantified, conditional and
508 -- case expressions) instead of the rewritten ones.
510 Use_Expression_With_Actions := False;
512 -- Enable assertions and debug pragmas, since they give valuable
513 -- extra information for formal verification.
515 Assertions_Enabled := True;
516 Debug_Pragmas_Enabled := True;
518 -- Turn off style check options since we are not interested in any
519 -- front-end warnings when we are getting Alfa output.
521 Reset_Style_Check_Options;
523 -- Suppress compiler warnings, since what we are interested in here
524 -- is what formal verification can find out.
526 Warning_Mode := Suppress;
528 -- Suppress the generation of name tables for enumerations, which are
529 -- not needed for formal verification, and fall outside the Alfa
530 -- subset (use of pointers).
532 Global_Discard_Names := True;
534 -- Suppress the expansion of tagged types and dispatching calls,
535 -- which lead to the generation of non-Alfa code (use of pointers),
536 -- which is more complex to formally verify than the original source.
538 Tagged_Type_Expansion := False;
541 -- If the inlining level has not been set by the user, compute it from
542 -- the optimization level: 1 at -O1/-O2 (and -Os), 2 at -O3 and above.
544 if Inline_Level = 0 then
545 if Optimization_Level < 3 then
552 -- Finally capture adjusted value of Suppress_Options as the initial
553 -- value for Scope_Suppress, which will be modified as we move from
554 -- scope to scope (by Suppress/Unsuppress/Overflow_Checks pragmas).
556 Sem.Scope_Suppress := Opt.Suppress_Options;
557 end Adjust_Global_Switches;
563 procedure Check_Bad_Body is
564 Sname : Unit_Name_Type;
565 Src_Ind : Source_File_Index;
566 Fname : File_Name_Type;
568 procedure Bad_Body_Error (Msg : String);
569 -- Issue message for bad body found
575 procedure Bad_Body_Error (Msg : String) is
577 Error_Msg_N (Msg, Main_Unit_Node);
578 Error_Msg_File_1 := Fname;
579 Error_Msg_N ("remove incorrect body in file{!", Main_Unit_Node);
582 -- Start of processing for Check_Bad_Body
585 -- Nothing to do if we are only checking syntax, because we don't know
586 -- enough to know if we require or forbid a body in this case.
588 if Operating_Mode = Check_Syntax then
592 -- Check for body not allowed
594 if (Main_Kind = N_Package_Declaration
595 and then not Body_Required (Main_Unit_Node))
596 or else (Main_Kind = N_Generic_Package_Declaration
597 and then not Body_Required (Main_Unit_Node))
598 or else Main_Kind = N_Package_Renaming_Declaration
599 or else Main_Kind = N_Subprogram_Renaming_Declaration
600 or else Nkind (Original_Node (Unit (Main_Unit_Node)))
601 in N_Generic_Instantiation
603 Sname := Unit_Name (Main_Unit);
605 -- If we do not already have a body name, then get the body name
606 -- (but how can we have a body name here???)
608 if not Is_Body_Name (Sname) then
609 Sname := Get_Body_Name (Sname);
612 Fname := Get_File_Name (Sname, Subunit => False);
613 Src_Ind := Load_Source_File (Fname);
615 -- Case where body is present and it is not a subunit. Exclude the
616 -- subunit case, because it has nothing to do with the package we are
617 -- compiling. It is illegal for a child unit and a subunit with the
618 -- same expanded name (RM 10.2(9)) to appear together in a partition,
619 -- but there is nothing to stop a compilation environment from having
620 -- both, and the test here simply allows that. If there is an attempt
621 -- to include both in a partition, this is diagnosed at bind time. In
622 -- Ada 83 mode this is not a warning case.
624 -- Note: if weird file names are being used, we can have a situation
625 -- where the file name that supposedly contains body in fact contains
626 -- a spec, or we can't tell what it contains. Skip the error message
629 -- Also ignore body that is nothing but pragma No_Body; (that's the
630 -- whole point of this pragma, to be used this way and to cause the
631 -- body file to be ignored in this context).
633 if Src_Ind /= No_Source_File
634 and then Get_Expected_Unit_Type (Fname) = Expect_Body
635 and then not Source_File_Is_Subunit (Src_Ind)
636 and then not Source_File_Is_No_Body (Src_Ind)
638 Errout.Finalize (Last_Call => False);
640 Error_Msg_Unit_1 := Sname;
642 -- Ada 83 case of a package body being ignored. This is not an
643 -- error as far as the Ada 83 RM is concerned, but it is almost
644 -- certainly not what is wanted so output a warning. Give this
645 -- message only if there were no errors, since otherwise it may
646 -- be incorrect (we may have misinterpreted a junk spec as not
647 -- needing a body when it really does).
649 if Main_Kind = N_Package_Declaration
650 and then Ada_Version = Ada_83
651 and then Operating_Mode = Generate_Code
652 and then Distribution_Stub_Mode /= Generate_Caller_Stub_Body
653 and then not Compilation_Errors
656 ("package $$ does not require a body?", Main_Unit_Node);
657 Error_Msg_File_1 := Fname;
658 Error_Msg_N ("body in file{? will be ignored", Main_Unit_Node);
660 -- Ada 95 cases of a body file present when no body is
661 -- permitted. This we consider to be an error.
664 -- For generic instantiations, we never allow a body
666 if Nkind (Original_Node (Unit (Main_Unit_Node)))
667 in N_Generic_Instantiation
670 ("generic instantiation for $$ does not allow a body");
672 -- A library unit that is a renaming never allows a body
674 elsif Main_Kind in N_Renaming_Declaration then
676 ("renaming declaration for $$ does not allow a body!");
678 -- Remaining cases are packages and generic packages. Here
679 -- we only do the test if there are no previous errors,
680 -- because if there are errors, they may lead us to
681 -- incorrectly believe that a package does not allow a body
682 -- when in fact it does.
684 elsif not Compilation_Errors then
685 if Main_Kind = N_Package_Declaration then
687 ("package $$ does not allow a body!");
689 elsif Main_Kind = N_Generic_Package_Declaration then
691 ("generic package $$ does not allow a body!");
704 procedure Check_Rep_Info is
706 if List_Representation_Info /= 0
707 or else List_Representation_Info_Mechanisms
712 ("cannot generate representation information, no code generated");
719 -- Start of processing for Gnat1drv
722 -- This inner block is set up to catch assertion errors and constraint
723 -- errors. Since the code for handling these errors can cause another
724 -- exception to be raised (namely Unrecoverable_Error), we need two
725 -- nested blocks, so that the outer one handles unrecoverable error.
728 -- Initialize all packages. For the most part, these initialization
729 -- calls can be made in any order. Exceptions are as follows:
731 -- Lib.Initialize need to be called before Scan_Compiler_Arguments,
732 -- because it initializes a table filled by Scan_Compiler_Arguments.
738 Scan_Compiler_Arguments;
739 Osint.Add_Default_Search_Dirs;
759 Sem_Type.Init_Interp_Tables;
761 -- Acquire target parameters from system.ads (source of package System)
766 S : Source_File_Index;
770 Name_Buffer (1 .. 10) := "system.ads";
773 S := Load_Source_File (N);
775 if S = No_Source_File then
777 ("fatal error, run-time library not installed correctly");
778 Write_Line ("cannot locate file system.ads");
779 raise Unrecoverable_Error;
781 -- Remember source index of system.ads (which was read successfully)
784 System_Source_File_Index := S;
787 Targparm.Get_Target_Parameters
788 (System_Text => Source_Text (S),
789 Source_First => Source_First (S),
790 Source_Last => Source_Last (S));
792 -- Acquire configuration pragma information from Targparm
794 Restrict.Restrictions := Targparm.Restrictions_On_Target;
797 Adjust_Global_Switches;
799 -- Output copyright notice if full list mode unless we have a list
800 -- file, in which case we defer this so that it is output in the file
802 if (Verbose_Mode or else (Full_List and then Full_List_File_Name = null))
803 and then not Debug_Flag_7
807 Write_Str (Gnat_Version_String);
809 Write_Str ("Copyright 1992-" & Current_Year
810 & ", Free Software Foundation, Inc.");
814 -- Check we do not have more than one source file, this happens only in
815 -- the case where the driver is called directly, it cannot happen when
816 -- gnat1 is invoked from gcc in the normal case.
818 if Osint.Number_Of_Files /= 1 then
821 Osint.Fail ("you must provide one source file");
823 elsif Usage_Requested then
827 Original_Operating_Mode := Operating_Mode;
830 -- Exit with errors if the main source could not be parsed. Also, when
831 -- -gnatd.H is present, the source file is not set.
833 if Sinput.Main_Source_File = No_Source_File then
835 -- Handle -gnatd.H debug mode
837 if Debug_Flag_Dot_HH then
839 -- For -gnatd.H, lock all the tables to keep the convention that
840 -- the backend needs to unlock the tables it wants to touch.
853 -- And all we need to do is to call the back end
855 Back_End.Call_Back_End (Back_End.Generate_Object);
858 Errout.Finalize (Last_Call => True);
859 Errout.Output_Messages;
860 Exit_Program (E_Errors);
863 Main_Unit_Node := Cunit (Main_Unit);
864 Main_Kind := Nkind (Unit (Main_Unit_Node));
867 -- In CodePeer mode we always delete old SCIL files before regenerating
868 -- new ones, in case of e.g. errors, and also to remove obsolete scilx
869 -- files generated by CodePeer itself.
871 if CodePeer_Mode then
872 Comperr.Delete_SCIL_Files;
875 -- Exit if compilation errors detected
877 Errout.Finalize (Last_Call => False);
879 if Compilation_Errors then
881 Sem_Ch13.Validate_Unchecked_Conversions;
882 Sem_Ch13.Validate_Address_Clauses;
883 Sem_Ch13.Validate_Independence;
884 Errout.Output_Messages;
887 -- Generate ALI file if specially requested
889 if Opt.Force_ALI_Tree_File then
890 Write_ALI (Object => False);
894 Errout.Finalize (Last_Call => True);
895 Exit_Program (E_Errors);
898 -- Set Generate_Code on main unit and its spec. We do this even if are
899 -- not generating code, since Lib-Writ uses this to determine which
900 -- units get written in the ali file.
902 Set_Generate_Code (Main_Unit);
904 -- If we have a corresponding spec, and it comes from source or it is
905 -- not a generated spec for a child subprogram body, then we need object
906 -- code for the spec unit as well.
908 if Nkind (Unit (Main_Unit_Node)) in N_Unit_Body
909 and then not Acts_As_Spec (Main_Unit_Node)
911 if Nkind (Unit (Main_Unit_Node)) = N_Subprogram_Body
912 and then not Comes_From_Source (Library_Unit (Main_Unit_Node))
917 (Get_Cunit_Unit_Number (Library_Unit (Main_Unit_Node)));
921 -- Case of no code required to be generated, exit indicating no error
923 if Original_Operating_Mode = Check_Syntax then
925 Errout.Finalize (Last_Call => True);
926 Errout.Output_Messages;
931 -- Use a goto instead of calling Exit_Program so that finalization
936 elsif Original_Operating_Mode = Check_Semantics then
937 Back_End_Mode := Declarations_Only;
939 -- All remaining cases are cases in which the user requested that code
940 -- be generated (i.e. no -gnatc or -gnats switch was used). Check if we
941 -- can in fact satisfy this request.
943 -- Cannot generate code if someone has turned off code generation for
944 -- any reason at all. We will try to figure out a reason below.
946 elsif Operating_Mode /= Generate_Code then
947 Back_End_Mode := Skip;
949 -- We can generate code for a subprogram body unless there were missing
950 -- subunits. Note that we always generate code for all generic units (a
951 -- change from some previous versions of GNAT).
953 elsif Main_Kind = N_Subprogram_Body and then not Subunits_Missing then
954 Back_End_Mode := Generate_Object;
956 -- We can generate code for a package body unless there are subunits
957 -- missing (note that we always generate code for generic units, which
958 -- is a change from some earlier versions of GNAT).
960 elsif Main_Kind = N_Package_Body and then not Subunits_Missing then
961 Back_End_Mode := Generate_Object;
963 -- We can generate code for a package declaration or a subprogram
964 -- declaration only if it does not required a body.
966 elsif Nkind_In (Main_Kind,
967 N_Package_Declaration,
968 N_Subprogram_Declaration)
970 (not Body_Required (Main_Unit_Node)
972 Distribution_Stub_Mode = Generate_Caller_Stub_Body)
974 Back_End_Mode := Generate_Object;
976 -- We can generate code for a generic package declaration of a generic
977 -- subprogram declaration only if does not require a body.
979 elsif Nkind_In (Main_Kind, N_Generic_Package_Declaration,
980 N_Generic_Subprogram_Declaration)
981 and then not Body_Required (Main_Unit_Node)
983 Back_End_Mode := Generate_Object;
985 -- Compilation units that are renamings do not require bodies, so we can
986 -- generate code for them.
988 elsif Nkind_In (Main_Kind, N_Package_Renaming_Declaration,
989 N_Subprogram_Renaming_Declaration)
991 Back_End_Mode := Generate_Object;
993 -- Compilation units that are generic renamings do not require bodies
994 -- so we can generate code for them.
996 elsif Main_Kind in N_Generic_Renaming_Declaration then
997 Back_End_Mode := Generate_Object;
999 -- It's not an error to generate SCIL for e.g. a spec which has a body
1001 elsif CodePeer_Mode then
1002 Back_End_Mode := Generate_Object;
1004 -- In all other cases (specs which have bodies, generics, and bodies
1005 -- where subunits are missing), we cannot generate code and we generate
1006 -- a warning message. Note that generic instantiations are gone at this
1007 -- stage since they have been replaced by their instances.
1010 Back_End_Mode := Skip;
1013 -- At this stage Back_End_Mode is set to indicate if the backend should
1014 -- be called to generate code. If it is Skip, then code generation has
1015 -- been turned off, even though code was requested by the original
1016 -- command. This is not an error from the user point of view, but it is
1017 -- an error from the point of view of the gcc driver, so we must exit
1018 -- with an error status.
1020 -- We generate an informative message (from the gcc point of view, it
1021 -- is an error message, but from the users point of view this is not an
1022 -- error, just a consequence of compiling something that cannot
1025 if Back_End_Mode = Skip then
1027 Write_Str ("cannot generate code for ");
1028 Write_Str ("file ");
1029 Write_Name (Unit_File_Name (Main_Unit));
1031 if Subunits_Missing then
1032 Write_Str (" (missing subunits)");
1035 -- Force generation of ALI file, for backward compatibility
1037 Opt.Force_ALI_Tree_File := True;
1039 elsif Main_Kind = N_Subunit then
1040 Write_Str (" (subunit)");
1043 -- Force generation of ALI file, for backward compatibility
1045 Opt.Force_ALI_Tree_File := True;
1047 elsif Main_Kind = N_Subprogram_Declaration then
1048 Write_Str (" (subprogram spec)");
1051 -- Generic package body in GNAT implementation mode
1053 elsif Main_Kind = N_Package_Body and then GNAT_Mode then
1054 Write_Str (" (predefined generic)");
1057 -- Force generation of ALI file, for backward compatibility
1059 Opt.Force_ALI_Tree_File := True;
1061 -- Only other case is a package spec
1064 Write_Str (" (package spec)");
1068 Set_Standard_Output;
1070 Sem_Ch13.Validate_Unchecked_Conversions;
1071 Sem_Ch13.Validate_Address_Clauses;
1072 Sem_Ch13.Validate_Independence;
1073 Errout.Finalize (Last_Call => True);
1074 Errout.Output_Messages;
1078 -- Generate ALI file if specially requested, or for missing subunits,
1079 -- subunits or predefined generic.
1081 if Opt.Force_ALI_Tree_File then
1082 Write_ALI (Object => False);
1088 -- Exit program with error indication, to kill object file
1090 Exit_Program (E_No_Code);
1093 -- In -gnatc mode, we only do annotation if -gnatt or -gnatR is also set
1094 -- as indicated by Back_Annotate_Rep_Info being set to True.
1096 -- We don't call for annotations on a subunit, because to process those
1097 -- the back-end requires that the parent(s) be properly compiled.
1099 -- Annotation is suppressed for targets where front-end layout is
1100 -- enabled, because the front end determines representations.
1102 -- Annotation is also suppressed in the case of compiling for a VM,
1103 -- since representations are largely symbolic there.
1105 if Back_End_Mode = Declarations_Only
1106 and then (not (Back_Annotate_Rep_Info or Generate_SCIL)
1107 or else Main_Kind = N_Subunit
1108 or else Targparm.Frontend_Layout_On_Target
1109 or else Targparm.VM_Target /= No_VM)
1111 Sem_Ch13.Validate_Unchecked_Conversions;
1112 Sem_Ch13.Validate_Address_Clauses;
1113 Sem_Ch13.Validate_Independence;
1114 Errout.Finalize (Last_Call => True);
1115 Errout.Output_Messages;
1116 Write_ALI (Object => False);
1124 -- Ensure that we properly register a dependency on system.ads, since
1125 -- even if we do not semantically depend on this, Targparm has read
1126 -- system parameters from the system.ads file.
1128 Lib.Writ.Ensure_System_Dependency;
1130 -- Add dependencies, if any, on preprocessing data file and on
1131 -- preprocessing definition file(s).
1133 Prepcomp.Add_Dependencies;
1135 -- Back end needs to explicitly unlock tables it needs to touch
1148 -- Here we call the back end to generate the output code
1150 Generating_Code := True;
1151 Back_End.Call_Back_End (Back_End_Mode);
1153 -- Once the backend is complete, we unlock the names table. This call
1154 -- allows a few extra entries, needed for example for the file name for
1155 -- the library file output.
1159 -- Generate the call-graph output of dispatching calls
1161 Exp_CG.Generate_CG_Output;
1163 -- Validate unchecked conversions (using the values for size and
1164 -- alignment annotated by the backend where possible).
1166 Sem_Ch13.Validate_Unchecked_Conversions;
1168 -- Validate address clauses (again using alignment values annotated
1169 -- by the backend where possible).
1171 Sem_Ch13.Validate_Address_Clauses;
1173 -- Validate independence pragmas (again using values annotated by
1174 -- the back end for component layout etc.)
1176 Sem_Ch13.Validate_Independence;
1178 -- Now we complete output of errors, rep info and the tree info. These
1179 -- are delayed till now, since it is perfectly possible for gigi to
1180 -- generate errors, modify the tree (in particular by setting flags
1181 -- indicating that elaboration is required, and also to back annotate
1182 -- representation information for List_Rep_Info.
1184 Errout.Finalize (Last_Call => True);
1185 Errout.Output_Messages;
1189 -- Only write the library if the backend did not generate any error
1190 -- messages. Otherwise signal errors to the driver program so that
1191 -- there will be no attempt to generate an object file.
1193 if Compilation_Errors then
1195 Exit_Program (E_Errors);
1198 Write_ALI (Object => (Back_End_Mode = Generate_Object));
1200 if not Compilation_Errors then
1202 -- In case of ada backends, we need to make sure that the generated
1203 -- object file has a timestamp greater than the ALI file. We do this
1204 -- to make gnatmake happy when checking the ALI and obj timestamps,
1205 -- where it expects the object file being written after the ali file.
1207 -- Gnatmake's assumption is true for gcc platforms where the gcc
1208 -- wrapper needs to call the assembler after calling gnat1, but is
1209 -- not true for ada backends, where the object files are created
1210 -- directly by gnat1 (so are created before the ali file).
1212 Back_End.Gen_Or_Update_Object_File;
1215 -- Generate ASIS tree after writing the ALI file, since in ASIS mode,
1216 -- Write_ALI may in fact result in further tree decoration from the
1217 -- original tree file. Note that we dump the tree just before generating
1218 -- it, so that the dump will exactly reflect what is written out.
1223 -- Finalize name table and we are all done
1228 -- Handle fatal internal compiler errors
1230 when Rtsfind.RE_Not_Available =>
1231 Comperr.Compiler_Abort ("RE_Not_Available");
1233 when System.Assertions.Assert_Failure =>
1234 Comperr.Compiler_Abort ("Assert_Failure");
1236 when Constraint_Error =>
1237 Comperr.Compiler_Abort ("Constraint_Error");
1239 when Program_Error =>
1240 Comperr.Compiler_Abort ("Program_Error");
1242 when Storage_Error =>
1244 -- Assume this is a bug. If it is real, the message will in any case
1245 -- say Storage_Error, giving a strong hint!
1247 Comperr.Compiler_Abort ("Storage_Error");
1253 -- The outer exception handles an unrecoverable error
1256 when Unrecoverable_Error =>
1257 Errout.Finalize (Last_Call => True);
1258 Errout.Output_Messages;
1261 Write_Str ("compilation abandoned");
1264 Set_Standard_Output;
1267 Exit_Program (E_Errors);