1 ------------------------------------------------------------------------------
3 -- GNAT COMPILER COMPONENTS --
9 -- Copyright (C) 1992-2013, Free Software Foundation, Inc. --
11 -- GNAT is free software; you can redistribute it and/or modify it under --
12 -- terms of the GNU General Public License as published by the Free Soft- --
13 -- ware Foundation; either version 3, or (at your option) any later ver- --
14 -- sion. GNAT is distributed in the hope that it will be useful, but WITH- --
15 -- OUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY --
16 -- or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License --
17 -- for more details. You should have received a copy of the GNU General --
18 -- Public License distributed with GNAT; see file COPYING3. If not, go to --
19 -- http://www.gnu.org/licenses for a complete copy of the license. --
21 -- GNAT was originally developed by the GNAT team at New York University. --
22 -- Extensive contributions were provided by Ada Core Technologies Inc. --
24 ------------------------------------------------------------------------------
26 with Atree; use Atree;
27 with Back_End; use Back_End;
29 with Csets; use Csets;
30 with Debug; use Debug;
32 with Errout; use Errout;
34 with Exp_Ch6; use Exp_Ch6;
36 with Fname; use Fname;
37 with Fname.UF; use Fname.UF;
39 with Gnatvsn; use Gnatvsn;
43 with Lib.Writ; use Lib.Writ;
45 with Namet; use Namet;
48 with Osint; use Osint;
49 with Output; use Output;
52 with Repinfo; use Repinfo;
54 with Rident; use Rident;
64 with Sinfo; use Sinfo;
65 with Sinput.L; use Sinput.L;
67 with Sprint; use Sprint;
69 with Stylesw; use Stylesw;
70 with Targparm; use Targparm;
72 with Treepr; use Treepr;
74 with Types; use Types;
75 with Uintp; use Uintp;
76 with Uname; use Uname;
79 with Validsw; use Validsw;
81 with System.Assertions;
84 Main_Unit_Node : Node_Id;
85 -- Compilation unit node for main unit
87 Main_Kind : Node_Kind;
88 -- Kind of main compilation unit node
90 Back_End_Mode : Back_End.Back_End_Mode_Type;
91 -- Record back end mode
93 procedure Adjust_Global_Switches;
94 -- There are various interactions between front end switch settings,
95 -- including debug switch settings and target dependent parameters.
96 -- This procedure takes care of properly handling these interactions.
97 -- We do it after scanning out all the switches, so that we are not
98 -- depending on the order in which switches appear.
100 procedure Check_Bad_Body;
101 -- Called to check if the unit we are compiling has a bad body
103 procedure Check_Rep_Info;
104 -- Called when we are not generating code, to check if -gnatR was requested
105 -- and if so, explain that we will not be honoring the request.
107 ----------------------------
108 -- Adjust_Global_Switches --
109 ----------------------------
111 procedure Adjust_Global_Switches is
113 -- -gnatd.M enables Relaxed_RM_Semantics
115 if Debug_Flag_Dot_MM then
116 Relaxed_RM_Semantics := True;
119 -- Disable CodePeer_Mode in Check_Syntax, since we need front-end
122 if Operating_Mode = Check_Syntax then
123 CodePeer_Mode := False;
126 -- Set ASIS mode if -gnatt and -gnatc are set
128 if Operating_Mode = Check_Semantics and then Tree_Output then
131 -- Turn off inlining in ASIS mode, since ASIS cannot handle the extra
132 -- information in the trees caused by inlining being active.
134 -- More specifically, the tree seems to be malformed from the ASIS
135 -- point of view if -gnatc and -gnatn appear together???
137 Inline_Active := False;
139 -- Turn off SCIL generation and CodePeer mode in semantics mode,
140 -- since SCIL requires front-end expansion.
142 Generate_SCIL := False;
143 CodePeer_Mode := False;
146 -- SCIL mode needs to disable front-end inlining since the generated
147 -- trees (in particular order and consistency between specs compiled
148 -- as part of a main unit or as part of a with-clause) are causing
151 if Generate_SCIL then
152 Front_End_Inlining := False;
155 -- Tune settings for optimal SCIL generation in CodePeer mode
157 if CodePeer_Mode then
159 -- Turn off inlining, confuses CodePeer output and gains nothing
161 Front_End_Inlining := False;
162 Inline_Active := False;
164 -- Disable front-end optimizations, to keep the tree as close to the
165 -- source code as possible, and also to avoid inconsistencies between
166 -- trees when using different optimization switches.
168 Optimization_Level := 0;
170 -- Enable some restrictions systematically to simplify the generated
171 -- code (and ease analysis). Note that restriction checks are also
172 -- disabled in CodePeer mode, see Restrict.Check_Restriction, and
173 -- user specified Restrictions pragmas are ignored, see
174 -- Sem_Prag.Process_Restrictions_Or_Restriction_Warnings.
176 Restrict.Restrictions.Set (No_Initialize_Scalars) := True;
177 Restrict.Restrictions.Set (No_Task_Hierarchy) := True;
178 Restrict.Restrictions.Set (No_Abort_Statements) := True;
179 Restrict.Restrictions.Set (Max_Asynchronous_Select_Nesting) := True;
180 Restrict.Restrictions.Value (Max_Asynchronous_Select_Nesting) := 0;
182 -- Suppress division by zero and access checks since they are handled
183 -- implicitly by CodePeer.
185 -- Turn off dynamic elaboration checks: generates inconsistencies in
186 -- trees between specs compiled as part of a main unit or as part of
189 -- Turn off alignment checks: these cannot be proved statically by
190 -- CodePeer and generate false positives.
192 -- Enable all other language checks
194 Suppress_Options.Suppress :=
195 (Access_Check => True,
196 Alignment_Check => True,
197 Division_Check => True,
198 Elaboration_Check => True,
201 Dynamic_Elaboration_Checks := False;
203 -- Set STRICT mode for overflow checks if not set explicitly. This
204 -- prevents suppressing of overflow checks by default, in code down
207 if Suppress_Options.Overflow_Mode_General = Not_Set then
208 Suppress_Options.Overflow_Mode_General := Strict;
209 Suppress_Options.Overflow_Mode_Assertions := Strict;
212 -- CodePeer handles division and overflow checks directly, based on
213 -- the marks set by the frontend, hence no special expansion should
214 -- be performed in the frontend for division and overflow checks.
216 Backend_Divide_Checks_On_Target := True;
217 Backend_Overflow_Checks_On_Target := True;
219 -- Kill debug of generated code, since it messes up sloc values
221 Debug_Generated_Code := False;
223 -- Turn cross-referencing on in case it was disabled (e.g. by -gnatD)
224 -- Do we really need to spend time generating xref in CodePeer
225 -- mode??? Consider setting Xref_Active to False.
229 -- Polling mode forced off, since it generates confusing junk
231 Polling_Required := False;
233 -- Set operating mode to Generate_Code to benefit from full front-end
234 -- expansion (e.g. generics).
236 Operating_Mode := Generate_Code;
238 -- We need SCIL generation of course
240 Generate_SCIL := True;
242 -- Enable assertions and debug pragmas, since they give CodePeer
243 -- valuable extra information.
245 Assertions_Enabled := True;
246 Debug_Pragmas_Enabled := True;
248 -- Disable all simple value propagation. This is an optimization
249 -- which is valuable for code optimization, and also for generation
250 -- of compiler warnings, but these are being turned off by default,
251 -- and CodePeer generates better messages (referencing original
252 -- variables) this way.
254 Debug_Flag_MM := True;
256 -- Set normal RM validity checking, and checking of IN OUT parameters
257 -- (this might give CodePeer more useful checks to analyze, to be
258 -- confirmed???). All other validity checking is turned off, since
259 -- this can generate very complex trees that only confuse CodePeer
260 -- and do not bring enough useful info.
262 Reset_Validity_Check_Options;
263 Validity_Check_Default := True;
264 Validity_Check_In_Out_Params := True;
265 Validity_Check_In_Params := True;
267 -- Turn off style check options since we are not interested in any
268 -- front-end warnings when we are getting CodePeer output.
270 Reset_Style_Check_Options;
272 -- Always perform semantics and generate ali files in CodePeer mode,
273 -- so that a gnatmake -c -k will proceed further when possible.
275 Force_ALI_Tree_File := True;
276 Try_Semantics := True;
278 -- Make the Ada front-end more liberal so that the compiler will
279 -- allow illegal code that is allowed by other compilers. CodePeer
280 -- is in the business of finding problems, not enforcing rules!
281 -- This is useful when using CodePeer mode with other compilers.
283 Relaxed_RM_Semantics := True;
286 if Relaxed_RM_Semantics then
287 Overriding_Renamings := True;
290 -- Set switches for formal verification mode
292 if Debug_Flag_Dot_VV then
293 Formal_Extensions := True;
296 -- Alfa_Mode is activated by default in the gnat2why executable, but
297 -- can also be activated using the -gnatd.F switch.
299 if Debug_Flag_Dot_FF or else Alfa_Mode then
302 -- Set strict standard interpretation of compiler permissions
304 if Debug_Flag_Dot_DD then
305 Strict_Alfa_Mode := True;
308 -- Distinguish between the two modes of gnat2why: frame condition
309 -- generation (generation of ALI files) and translation of Why (no
310 -- ALI files generated). This is done with the switch -gnatd.G,
311 -- which activates frame condition mode. The other changes in
312 -- behavior depending on this switch are done in gnat2why directly.
314 if Debug_Flag_Dot_GG then
315 Frame_Condition_Mode := True;
317 Opt.Disable_ALI_File := True;
320 -- Turn off inlining, which would confuse formal verification output
323 Front_End_Inlining := False;
324 Inline_Active := False;
326 -- Disable front-end optimizations, to keep the tree as close to the
327 -- source code as possible, and also to avoid inconsistencies between
328 -- trees when using different optimization switches.
330 Optimization_Level := 0;
332 -- Enable some restrictions systematically to simplify the generated
333 -- code (and ease analysis). Note that restriction checks are also
334 -- disabled in Alfa mode, see Restrict.Check_Restriction, and user
335 -- specified Restrictions pragmas are ignored, see
336 -- Sem_Prag.Process_Restrictions_Or_Restriction_Warnings.
338 Restrict.Restrictions.Set (No_Initialize_Scalars) := True;
340 -- Note: at this point we used to suppress various checks, but that
341 -- is not what we want. We need the semantic processing for these
342 -- checks (which will set flags like Do_Overflow_Check, showing the
343 -- points at which potential checks are required semantically). We
344 -- don't want the expansion associated with these checks, but that
345 -- happens anyway because this expansion is simply not done in the
346 -- Alfa version of the expander.
348 -- Turn off dynamic elaboration checks: generates inconsistencies in
349 -- trees between specs compiled as part of a main unit or as part of
352 Dynamic_Elaboration_Checks := False;
354 -- Set STRICT mode for overflow checks if not set explicitly. This
355 -- prevents suppressing of overflow checks by default, in code down
358 if Suppress_Options.Overflow_Mode_General = Not_Set then
359 Suppress_Options.Overflow_Mode_General := Strict;
360 Suppress_Options.Overflow_Mode_Assertions := Strict;
363 -- Kill debug of generated code, since it messes up sloc values
365 Debug_Generated_Code := False;
367 -- Turn cross-referencing on in case it was disabled (e.g. by -gnatD)
368 -- as it is needed for computing effects of subprograms in the formal
369 -- verification backend.
373 -- Polling mode forced off, since it generates confusing junk
375 Polling_Required := False;
377 -- Set operating mode to Generate_Code, but full front-end expansion
378 -- is not desirable in Alfa mode, so a light expansion is performed
381 Operating_Mode := Generate_Code;
385 Debug_Flag_HH := True;
387 -- Disable Expressions_With_Actions nodes
389 -- The gnat2why backend does not deal with Expressions_With_Actions
390 -- in all places (in particular assertions). It is difficult to
391 -- determine in the frontend which cases are allowed, so we disable
392 -- Expressions_With_Actions entirely. Even in the cases where
393 -- gnat2why deals with Expressions_With_Actions, it is easier to
394 -- deal with the original constructs (quantified, conditional and
395 -- case expressions) instead of the rewritten ones.
397 Use_Expression_With_Actions := False;
399 -- Enable assertions and debug pragmas, since they give valuable
400 -- extra information for formal verification.
402 Assertions_Enabled := True;
403 Debug_Pragmas_Enabled := True;
405 -- Turn off style check options since we are not interested in any
406 -- front-end warnings when we are getting Alfa output.
408 Reset_Style_Check_Options;
410 -- Suppress compiler warnings, since what we are interested in here
411 -- is what formal verification can find out.
413 Warning_Mode := Suppress;
415 -- Suppress the generation of name tables for enumerations, which are
416 -- not needed for formal verification, and fall outside the Alfa
417 -- subset (use of pointers).
419 Global_Discard_Names := True;
421 -- Suppress the expansion of tagged types and dispatching calls,
422 -- which lead to the generation of non-Alfa code (use of pointers),
423 -- which is more complex to formally verify than the original source.
425 Tagged_Type_Expansion := False;
429 -- Set Configurable_Run_Time mode if system.ads flag set
431 if Targparm.Configurable_Run_Time_On_Target or Debug_Flag_YY then
432 Configurable_Run_Time_Mode := True;
435 -- Set -gnatR3m mode if debug flag A set
437 if Debug_Flag_AA then
438 Back_Annotate_Rep_Info := True;
439 List_Representation_Info := 1;
440 List_Representation_Info_Mechanisms := True;
443 -- Force Target_Strict_Alignment true if debug flag -gnatd.a is set
445 if Debug_Flag_Dot_A then
446 Ttypes.Target_Strict_Alignment := True;
449 -- Increase size of allocated entities if debug flag -gnatd.N is set
451 if Debug_Flag_Dot_NN then
452 Atree.Num_Extension_Nodes := Atree.Num_Extension_Nodes + 1;
455 -- Disable static allocation of dispatch tables if -gnatd.t or if layout
456 -- is enabled. The front end's layout phase currently treats types that
457 -- have discriminant-dependent arrays as not being static even when a
458 -- discriminant constraint on the type is static, and this leads to
459 -- problems with subtypes of type Ada.Tags.Dispatch_Table_Wrapper. ???
461 if Debug_Flag_Dot_T or else Frontend_Layout_On_Target then
462 Static_Dispatch_Tables := False;
465 -- Flip endian mode if -gnatd8 set
468 Ttypes.Bytes_Big_Endian := not Ttypes.Bytes_Big_Endian;
471 -- Deal with forcing OpenVMS switches True if debug flag M is set, but
472 -- record the setting of Targparm.Open_VMS_On_Target in True_VMS_Target
473 -- before doing this, so we know if we are in real OpenVMS or not!
475 Opt.True_VMS_Target := Targparm.OpenVMS_On_Target;
478 Targparm.OpenVMS_On_Target := True;
479 Hostparm.OpenVMS := True;
482 -- Activate front end layout if debug flag -gnatdF is set
484 if Debug_Flag_FF then
485 Targparm.Frontend_Layout_On_Target := True;
488 -- Set and check exception mechanism
490 if Targparm.ZCX_By_Default_On_Target then
491 Exception_Mechanism := Back_End_Exceptions;
494 -- Set proper status for overflow check mechanism
496 -- If already set (by -gnato or above in Alfa or CodePeer mode) then we
497 -- have nothing to do.
499 if Opt.Suppress_Options.Overflow_Mode_General /= Not_Set then
502 -- Otherwise set overflow mode defaults
505 -- Otherwise set overflow checks off by default
507 Suppress_Options.Suppress (Overflow_Check) := True;
509 -- Set appropriate default overflow handling mode. Note: at present
510 -- we set STRICT in all three of the following cases. They are
511 -- separated because in the future we may make different choices.
513 -- By default set STRICT mode if -gnatg in effect
516 Suppress_Options.Overflow_Mode_General := Strict;
517 Suppress_Options.Overflow_Mode_Assertions := Strict;
519 -- If we have backend divide and overflow checks, then by default
520 -- overflow checks are STRICT. Historically this code used to also
521 -- activate overflow checks, although no target currently has these
522 -- flags set, so this was dead code anyway.
524 elsif Targparm.Backend_Divide_Checks_On_Target
526 Targparm.Backend_Overflow_Checks_On_Target
528 Suppress_Options.Overflow_Mode_General := Strict;
529 Suppress_Options.Overflow_Mode_Assertions := Strict;
531 -- Otherwise for now, default is STRICT mode. This may change in the
532 -- future, but for now this is the compatible behavior with previous
536 Suppress_Options.Overflow_Mode_General := Strict;
537 Suppress_Options.Overflow_Mode_Assertions := Strict;
541 -- Set default for atomic synchronization. As this synchronization
542 -- between atomic accesses can be expensive, and not typically needed
543 -- on some targets, an optional target parameter can turn the option
544 -- off. Note Atomic Synchronization is implemented as check.
546 Suppress_Options.Suppress (Atomic_Synchronization) :=
547 not Atomic_Sync_Default_On_Target;
549 -- Set switch indicating if we can use N_Expression_With_Actions
551 -- Debug flag -gnatd.X decisively sets usage on
553 if Debug_Flag_Dot_XX then
554 Use_Expression_With_Actions := True;
556 -- Debug flag -gnatd.Y decisively sets usage off
558 elsif Debug_Flag_Dot_YY then
559 Use_Expression_With_Actions := False;
561 -- Otherwise this feature is implemented, so we allow its use
564 Use_Expression_With_Actions := True;
567 -- Set switch indicating if back end can handle limited types, and
568 -- guarantee that no incorrect copies are made (e.g. in the context
569 -- of an if or case expression).
571 -- Debug flag -gnatd.L decisively sets usage on
573 if Debug_Flag_Dot_LL then
574 Back_End_Handles_Limited_Types := True;
576 -- If no debug flag, usage off for AAMP, VM, SCIL cases
579 or else VM_Target /= No_VM
580 or else Generate_SCIL
582 Back_End_Handles_Limited_Types := False;
584 -- Otherwise normal gcc back end, for now still turn flag off by
585 -- default, since there are unresolved problems in the front end.
588 Back_End_Handles_Limited_Types := False;
591 -- If the inlining level has not been set by the user, compute it from
592 -- the optimization level: 1 at -O1/-O2 (and -Os), 2 at -O3 and above.
594 if Inline_Level = 0 then
595 if Optimization_Level < 3 then
602 -- Finally capture adjusted value of Suppress_Options as the initial
603 -- value for Scope_Suppress, which will be modified as we move from
604 -- scope to scope (by Suppress/Unsuppress/Overflow_Checks pragmas).
606 Sem.Scope_Suppress := Opt.Suppress_Options;
607 end Adjust_Global_Switches;
613 procedure Check_Bad_Body is
614 Sname : Unit_Name_Type;
615 Src_Ind : Source_File_Index;
616 Fname : File_Name_Type;
618 procedure Bad_Body_Error (Msg : String);
619 -- Issue message for bad body found
625 procedure Bad_Body_Error (Msg : String) is
627 Error_Msg_N (Msg, Main_Unit_Node);
628 Error_Msg_File_1 := Fname;
629 Error_Msg_N ("remove incorrect body in file{!", Main_Unit_Node);
632 -- Start of processing for Check_Bad_Body
635 -- Nothing to do if we are only checking syntax, because we don't know
636 -- enough to know if we require or forbid a body in this case.
638 if Operating_Mode = Check_Syntax then
642 -- Check for body not allowed
644 if (Main_Kind = N_Package_Declaration
645 and then not Body_Required (Main_Unit_Node))
646 or else (Main_Kind = N_Generic_Package_Declaration
647 and then not Body_Required (Main_Unit_Node))
648 or else Main_Kind = N_Package_Renaming_Declaration
649 or else Main_Kind = N_Subprogram_Renaming_Declaration
650 or else Nkind (Original_Node (Unit (Main_Unit_Node)))
651 in N_Generic_Instantiation
653 Sname := Unit_Name (Main_Unit);
655 -- If we do not already have a body name, then get the body name
656 -- (but how can we have a body name here???)
658 if not Is_Body_Name (Sname) then
659 Sname := Get_Body_Name (Sname);
662 Fname := Get_File_Name (Sname, Subunit => False);
663 Src_Ind := Load_Source_File (Fname);
665 -- Case where body is present and it is not a subunit. Exclude the
666 -- subunit case, because it has nothing to do with the package we are
667 -- compiling. It is illegal for a child unit and a subunit with the
668 -- same expanded name (RM 10.2(9)) to appear together in a partition,
669 -- but there is nothing to stop a compilation environment from having
670 -- both, and the test here simply allows that. If there is an attempt
671 -- to include both in a partition, this is diagnosed at bind time. In
672 -- Ada 83 mode this is not a warning case.
674 -- Note: if weird file names are being used, we can have a situation
675 -- where the file name that supposedly contains body in fact contains
676 -- a spec, or we can't tell what it contains. Skip the error message
679 -- Also ignore body that is nothing but pragma No_Body; (that's the
680 -- whole point of this pragma, to be used this way and to cause the
681 -- body file to be ignored in this context).
683 if Src_Ind /= No_Source_File
684 and then Get_Expected_Unit_Type (Fname) = Expect_Body
685 and then not Source_File_Is_Subunit (Src_Ind)
686 and then not Source_File_Is_No_Body (Src_Ind)
688 Errout.Finalize (Last_Call => False);
690 Error_Msg_Unit_1 := Sname;
692 -- Ada 83 case of a package body being ignored. This is not an
693 -- error as far as the Ada 83 RM is concerned, but it is almost
694 -- certainly not what is wanted so output a warning. Give this
695 -- message only if there were no errors, since otherwise it may
696 -- be incorrect (we may have misinterpreted a junk spec as not
697 -- needing a body when it really does).
699 if Main_Kind = N_Package_Declaration
700 and then Ada_Version = Ada_83
701 and then Operating_Mode = Generate_Code
702 and then Distribution_Stub_Mode /= Generate_Caller_Stub_Body
703 and then not Compilation_Errors
706 ("package $$ does not require a body??", Main_Unit_Node);
707 Error_Msg_File_1 := Fname;
708 Error_Msg_N ("body in file{ will be ignored??", Main_Unit_Node);
710 -- Ada 95 cases of a body file present when no body is
711 -- permitted. This we consider to be an error.
714 -- For generic instantiations, we never allow a body
716 if Nkind (Original_Node (Unit (Main_Unit_Node)))
717 in N_Generic_Instantiation
720 ("generic instantiation for $$ does not allow a body");
722 -- A library unit that is a renaming never allows a body
724 elsif Main_Kind in N_Renaming_Declaration then
726 ("renaming declaration for $$ does not allow a body!");
728 -- Remaining cases are packages and generic packages. Here
729 -- we only do the test if there are no previous errors,
730 -- because if there are errors, they may lead us to
731 -- incorrectly believe that a package does not allow a body
732 -- when in fact it does.
734 elsif not Compilation_Errors then
735 if Main_Kind = N_Package_Declaration then
737 ("package $$ does not allow a body!");
739 elsif Main_Kind = N_Generic_Package_Declaration then
741 ("generic package $$ does not allow a body!");
754 procedure Check_Rep_Info is
756 if List_Representation_Info /= 0
757 or else List_Representation_Info_Mechanisms
762 ("cannot generate representation information, no code generated");
769 -- Start of processing for Gnat1drv
772 -- This inner block is set up to catch assertion errors and constraint
773 -- errors. Since the code for handling these errors can cause another
774 -- exception to be raised (namely Unrecoverable_Error), we need two
775 -- nested blocks, so that the outer one handles unrecoverable error.
778 -- Initialize all packages. For the most part, these initialization
779 -- calls can be made in any order. Exceptions are as follows:
781 -- Lib.Initialize need to be called before Scan_Compiler_Arguments,
782 -- because it initializes a table filled by Scan_Compiler_Arguments.
788 Scan_Compiler_Arguments;
789 Osint.Add_Default_Search_Dirs;
809 Sem_Type.Init_Interp_Tables;
811 -- Acquire target parameters from system.ads (source of package System)
816 S : Source_File_Index;
820 Name_Buffer (1 .. 10) := "system.ads";
823 S := Load_Source_File (N);
825 if S = No_Source_File then
827 ("fatal error, run-time library not installed correctly");
828 Write_Line ("cannot locate file system.ads");
829 raise Unrecoverable_Error;
831 -- Remember source index of system.ads (which was read successfully)
834 System_Source_File_Index := S;
837 Targparm.Get_Target_Parameters
838 (System_Text => Source_Text (S),
839 Source_First => Source_First (S),
840 Source_Last => Source_Last (S));
842 -- Acquire configuration pragma information from Targparm
844 Restrict.Restrictions := Targparm.Restrictions_On_Target;
847 Adjust_Global_Switches;
849 -- Output copyright notice if full list mode unless we have a list
850 -- file, in which case we defer this so that it is output in the file
852 if (Verbose_Mode or else (Full_List and then Full_List_File_Name = null))
853 and then not Debug_Flag_7
857 Write_Str (Gnat_Version_String);
859 Write_Str ("Copyright 1992-" & Current_Year
860 & ", Free Software Foundation, Inc.");
864 -- Check we do not have more than one source file, this happens only in
865 -- the case where the driver is called directly, it cannot happen when
866 -- gnat1 is invoked from gcc in the normal case.
868 if Osint.Number_Of_Files /= 1 then
871 Osint.Fail ("you must provide one source file");
873 elsif Usage_Requested then
877 Original_Operating_Mode := Operating_Mode;
880 -- Exit with errors if the main source could not be parsed. Also, when
881 -- -gnatd.H is present, the source file is not set.
883 if Sinput.Main_Source_File = No_Source_File then
885 -- Handle -gnatd.H debug mode
887 if Debug_Flag_Dot_HH then
889 -- For -gnatd.H, lock all the tables to keep the convention that
890 -- the backend needs to unlock the tables it wants to touch.
903 -- And all we need to do is to call the back end
905 Back_End.Call_Back_End (Back_End.Generate_Object);
908 Errout.Finalize (Last_Call => True);
909 Errout.Output_Messages;
910 Exit_Program (E_Errors);
913 Main_Unit_Node := Cunit (Main_Unit);
914 Main_Kind := Nkind (Unit (Main_Unit_Node));
917 -- In CodePeer mode we always delete old SCIL files before regenerating
918 -- new ones, in case of e.g. errors, and also to remove obsolete scilx
919 -- files generated by CodePeer itself.
921 if CodePeer_Mode then
922 Comperr.Delete_SCIL_Files;
925 -- Exit if compilation errors detected
927 Errout.Finalize (Last_Call => False);
929 if Compilation_Errors then
931 Sem_Ch13.Validate_Unchecked_Conversions;
932 Sem_Ch13.Validate_Address_Clauses;
933 Sem_Ch13.Validate_Independence;
934 Errout.Output_Messages;
937 -- Generate ALI file if specially requested
939 if Opt.Force_ALI_Tree_File then
940 Write_ALI (Object => False);
944 Errout.Finalize (Last_Call => True);
945 Exit_Program (E_Errors);
948 -- Set Generate_Code on main unit and its spec. We do this even if are
949 -- not generating code, since Lib-Writ uses this to determine which
950 -- units get written in the ali file.
952 Set_Generate_Code (Main_Unit);
954 -- If we have a corresponding spec, and it comes from source or it is
955 -- not a generated spec for a child subprogram body, then we need object
956 -- code for the spec unit as well.
958 if Nkind (Unit (Main_Unit_Node)) in N_Unit_Body
959 and then not Acts_As_Spec (Main_Unit_Node)
961 if Nkind (Unit (Main_Unit_Node)) = N_Subprogram_Body
962 and then not Comes_From_Source (Library_Unit (Main_Unit_Node))
967 (Get_Cunit_Unit_Number (Library_Unit (Main_Unit_Node)));
971 -- Case of no code required to be generated, exit indicating no error
973 if Original_Operating_Mode = Check_Syntax then
975 Errout.Finalize (Last_Call => True);
976 Errout.Output_Messages;
981 -- Use a goto instead of calling Exit_Program so that finalization
986 elsif Original_Operating_Mode = Check_Semantics then
987 Back_End_Mode := Declarations_Only;
989 -- All remaining cases are cases in which the user requested that code
990 -- be generated (i.e. no -gnatc or -gnats switch was used). Check if we
991 -- can in fact satisfy this request.
993 -- Cannot generate code if someone has turned off code generation for
994 -- any reason at all. We will try to figure out a reason below.
996 elsif Operating_Mode /= Generate_Code then
997 Back_End_Mode := Skip;
999 -- We can generate code for a subprogram body unless there were missing
1000 -- subunits. Note that we always generate code for all generic units (a
1001 -- change from some previous versions of GNAT).
1003 elsif Main_Kind = N_Subprogram_Body and then not Subunits_Missing then
1004 Back_End_Mode := Generate_Object;
1006 -- We can generate code for a package body unless there are subunits
1007 -- missing (note that we always generate code for generic units, which
1008 -- is a change from some earlier versions of GNAT).
1010 elsif Main_Kind = N_Package_Body and then not Subunits_Missing then
1011 Back_End_Mode := Generate_Object;
1013 -- We can generate code for a package declaration or a subprogram
1014 -- declaration only if it does not required a body.
1016 elsif Nkind_In (Main_Kind,
1017 N_Package_Declaration,
1018 N_Subprogram_Declaration)
1020 (not Body_Required (Main_Unit_Node)
1022 Distribution_Stub_Mode = Generate_Caller_Stub_Body)
1024 Back_End_Mode := Generate_Object;
1026 -- We can generate code for a generic package declaration of a generic
1027 -- subprogram declaration only if does not require a body.
1029 elsif Nkind_In (Main_Kind, N_Generic_Package_Declaration,
1030 N_Generic_Subprogram_Declaration)
1031 and then not Body_Required (Main_Unit_Node)
1033 Back_End_Mode := Generate_Object;
1035 -- Compilation units that are renamings do not require bodies, so we can
1036 -- generate code for them.
1038 elsif Nkind_In (Main_Kind, N_Package_Renaming_Declaration,
1039 N_Subprogram_Renaming_Declaration)
1041 Back_End_Mode := Generate_Object;
1043 -- Compilation units that are generic renamings do not require bodies
1044 -- so we can generate code for them.
1046 elsif Main_Kind in N_Generic_Renaming_Declaration then
1047 Back_End_Mode := Generate_Object;
1049 -- It is not an error to analyze in CodePeer mode a spec which requires
1050 -- a body, in order to generate SCIL for this spec.
1052 elsif CodePeer_Mode then
1053 Back_End_Mode := Generate_Object;
1055 -- It is not an error to analyze in Alfa mode a spec which requires a
1056 -- body, when the body is not available. During frame condition
1057 -- generation, the corresponding ALI file is generated. During
1058 -- translation to Why, Why code is generated for the spec.
1060 elsif Alfa_Mode then
1061 if Frame_Condition_Mode then
1062 Back_End_Mode := Declarations_Only;
1064 Back_End_Mode := Generate_Object;
1067 -- In all other cases (specs which have bodies, generics, and bodies
1068 -- where subunits are missing), we cannot generate code and we generate
1069 -- a warning message. Note that generic instantiations are gone at this
1070 -- stage since they have been replaced by their instances.
1073 Back_End_Mode := Skip;
1076 -- At this stage Back_End_Mode is set to indicate if the backend should
1077 -- be called to generate code. If it is Skip, then code generation has
1078 -- been turned off, even though code was requested by the original
1079 -- command. This is not an error from the user point of view, but it is
1080 -- an error from the point of view of the gcc driver, so we must exit
1081 -- with an error status.
1083 -- We generate an informative message (from the gcc point of view, it
1084 -- is an error message, but from the users point of view this is not an
1085 -- error, just a consequence of compiling something that cannot
1088 if Back_End_Mode = Skip then
1090 Write_Str ("cannot generate code for ");
1091 Write_Str ("file ");
1092 Write_Name (Unit_File_Name (Main_Unit));
1094 if Subunits_Missing then
1095 Write_Str (" (missing subunits)");
1098 -- Force generation of ALI file, for backward compatibility
1100 Opt.Force_ALI_Tree_File := True;
1102 elsif Main_Kind = N_Subunit then
1103 Write_Str (" (subunit)");
1106 -- Force generation of ALI file, for backward compatibility
1108 Opt.Force_ALI_Tree_File := True;
1110 elsif Main_Kind = N_Subprogram_Declaration then
1111 Write_Str (" (subprogram spec)");
1114 -- Generic package body in GNAT implementation mode
1116 elsif Main_Kind = N_Package_Body and then GNAT_Mode then
1117 Write_Str (" (predefined generic)");
1120 -- Force generation of ALI file, for backward compatibility
1122 Opt.Force_ALI_Tree_File := True;
1124 -- Only other case is a package spec
1127 Write_Str (" (package spec)");
1131 Set_Standard_Output;
1133 Sem_Ch13.Validate_Unchecked_Conversions;
1134 Sem_Ch13.Validate_Address_Clauses;
1135 Sem_Ch13.Validate_Independence;
1136 Errout.Finalize (Last_Call => True);
1137 Errout.Output_Messages;
1141 -- Generate ALI file if specially requested, or for missing subunits,
1142 -- subunits or predefined generic.
1144 if Opt.Force_ALI_Tree_File then
1145 Write_ALI (Object => False);
1151 -- Exit program with error indication, to kill object file
1153 Exit_Program (E_No_Code);
1156 -- In -gnatc mode, we only do annotation if -gnatt or -gnatR is also set
1157 -- as indicated by Back_Annotate_Rep_Info being set to True.
1159 -- We don't call for annotations on a subunit, because to process those
1160 -- the back-end requires that the parent(s) be properly compiled.
1162 -- Annotation is suppressed for targets where front-end layout is
1163 -- enabled, because the front end determines representations.
1165 -- Annotation is also suppressed in the case of compiling for a VM,
1166 -- since representations are largely symbolic there.
1168 if Back_End_Mode = Declarations_Only
1169 and then (not (Back_Annotate_Rep_Info or Generate_SCIL)
1170 or else Main_Kind = N_Subunit
1171 or else Targparm.Frontend_Layout_On_Target
1172 or else Targparm.VM_Target /= No_VM)
1174 Sem_Ch13.Validate_Unchecked_Conversions;
1175 Sem_Ch13.Validate_Address_Clauses;
1176 Sem_Ch13.Validate_Independence;
1177 Errout.Finalize (Last_Call => True);
1178 Errout.Output_Messages;
1179 Write_ALI (Object => False);
1187 -- Ensure that we properly register a dependency on system.ads, since
1188 -- even if we do not semantically depend on this, Targparm has read
1189 -- system parameters from the system.ads file.
1191 Lib.Writ.Ensure_System_Dependency;
1193 -- Add dependencies, if any, on preprocessing data file and on
1194 -- preprocessing definition file(s).
1196 Prepcomp.Add_Dependencies;
1198 -- Back end needs to explicitly unlock tables it needs to touch
1211 -- Here we call the back end to generate the output code
1213 Generating_Code := True;
1214 Back_End.Call_Back_End (Back_End_Mode);
1216 -- Once the backend is complete, we unlock the names table. This call
1217 -- allows a few extra entries, needed for example for the file name for
1218 -- the library file output.
1222 -- Generate the call-graph output of dispatching calls
1224 Exp_CG.Generate_CG_Output;
1226 -- Validate unchecked conversions (using the values for size and
1227 -- alignment annotated by the backend where possible).
1229 Sem_Ch13.Validate_Unchecked_Conversions;
1231 -- Validate address clauses (again using alignment values annotated
1232 -- by the backend where possible).
1234 Sem_Ch13.Validate_Address_Clauses;
1236 -- Validate independence pragmas (again using values annotated by
1237 -- the back end for component layout etc.)
1239 Sem_Ch13.Validate_Independence;
1241 -- Now we complete output of errors, rep info and the tree info. These
1242 -- are delayed till now, since it is perfectly possible for gigi to
1243 -- generate errors, modify the tree (in particular by setting flags
1244 -- indicating that elaboration is required, and also to back annotate
1245 -- representation information for List_Rep_Info.
1247 Errout.Finalize (Last_Call => True);
1248 Errout.Output_Messages;
1252 -- Only write the library if the backend did not generate any error
1253 -- messages. Otherwise signal errors to the driver program so that
1254 -- there will be no attempt to generate an object file.
1256 if Compilation_Errors then
1258 Exit_Program (E_Errors);
1261 Write_ALI (Object => (Back_End_Mode = Generate_Object));
1263 if not Compilation_Errors then
1265 -- In case of ada backends, we need to make sure that the generated
1266 -- object file has a timestamp greater than the ALI file. We do this
1267 -- to make gnatmake happy when checking the ALI and obj timestamps,
1268 -- where it expects the object file being written after the ali file.
1270 -- Gnatmake's assumption is true for gcc platforms where the gcc
1271 -- wrapper needs to call the assembler after calling gnat1, but is
1272 -- not true for ada backends, where the object files are created
1273 -- directly by gnat1 (so are created before the ali file).
1275 Back_End.Gen_Or_Update_Object_File;
1278 -- Generate ASIS tree after writing the ALI file, since in ASIS mode,
1279 -- Write_ALI may in fact result in further tree decoration from the
1280 -- original tree file. Note that we dump the tree just before generating
1281 -- it, so that the dump will exactly reflect what is written out.
1286 -- Finalize name table and we are all done
1291 -- Handle fatal internal compiler errors
1293 when Rtsfind.RE_Not_Available =>
1294 Comperr.Compiler_Abort ("RE_Not_Available");
1296 when System.Assertions.Assert_Failure =>
1297 Comperr.Compiler_Abort ("Assert_Failure");
1299 when Constraint_Error =>
1300 Comperr.Compiler_Abort ("Constraint_Error");
1302 when Program_Error =>
1303 Comperr.Compiler_Abort ("Program_Error");
1305 when Storage_Error =>
1307 -- Assume this is a bug. If it is real, the message will in any case
1308 -- say Storage_Error, giving a strong hint!
1310 Comperr.Compiler_Abort ("Storage_Error");
1316 -- The outer exception handles an unrecoverable error
1319 when Unrecoverable_Error =>
1320 Errout.Finalize (Last_Call => True);
1321 Errout.Output_Messages;
1324 Write_Str ("compilation abandoned");
1327 Set_Standard_Output;
1330 Exit_Program (E_Errors);