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 if Debug_Flag_Dot_FF then
299 -- Set strict standard interpretation of compiler permissions
301 if Debug_Flag_Dot_DD then
302 Strict_Alfa_Mode := True;
305 -- Turn off inlining, which would confuse formal verification output
308 Front_End_Inlining := False;
309 Inline_Active := False;
311 -- Disable front-end optimizations, to keep the tree as close to the
312 -- source code as possible, and also to avoid inconsistencies between
313 -- trees when using different optimization switches.
315 Optimization_Level := 0;
317 -- Enable some restrictions systematically to simplify the generated
318 -- code (and ease analysis). Note that restriction checks are also
319 -- disabled in Alfa mode, see Restrict.Check_Restriction, and user
320 -- specified Restrictions pragmas are ignored, see
321 -- Sem_Prag.Process_Restrictions_Or_Restriction_Warnings.
323 Restrict.Restrictions.Set (No_Initialize_Scalars) := True;
325 -- Note: at this point we used to suppress various checks, but that
326 -- is not what we want. We need the semantic processing for these
327 -- checks (which will set flags like Do_Overflow_Check, showing the
328 -- points at which potential checks are required semantically). We
329 -- don't want the expansion associated with these checks, but that
330 -- happens anyway because this expansion is simply not done in the
331 -- Alfa version of the expander.
333 -- Turn off dynamic elaboration checks: generates inconsistencies in
334 -- trees between specs compiled as part of a main unit or as part of
337 Dynamic_Elaboration_Checks := False;
339 -- Set STRICT mode for overflow checks if not set explicitly. This
340 -- prevents suppressing of overflow checks by default, in code down
343 if Suppress_Options.Overflow_Mode_General = Not_Set then
344 Suppress_Options.Overflow_Mode_General := Strict;
345 Suppress_Options.Overflow_Mode_Assertions := Strict;
348 -- Kill debug of generated code, since it messes up sloc values
350 Debug_Generated_Code := False;
352 -- Turn cross-referencing on in case it was disabled (e.g. by -gnatD)
353 -- as it is needed for computing effects of subprograms in the formal
354 -- verification backend.
358 -- Polling mode forced off, since it generates confusing junk
360 Polling_Required := False;
362 -- Set operating mode to Generate_Code, but full front-end expansion
363 -- is not desirable in Alfa mode, so a light expansion is performed
366 Operating_Mode := Generate_Code;
370 Debug_Flag_HH := True;
372 -- Disable Expressions_With_Actions nodes
374 -- The gnat2why backend does not deal with Expressions_With_Actions
375 -- in all places (in particular assertions). It is difficult to
376 -- determine in the frontend which cases are allowed, so we disable
377 -- Expressions_With_Actions entirely. Even in the cases where
378 -- gnat2why deals with Expressions_With_Actions, it is easier to
379 -- deal with the original constructs (quantified, conditional and
380 -- case expressions) instead of the rewritten ones.
382 Use_Expression_With_Actions := False;
384 -- Enable assertions and debug pragmas, since they give valuable
385 -- extra information for formal verification.
387 Assertions_Enabled := True;
388 Debug_Pragmas_Enabled := True;
390 -- Turn off style check options since we are not interested in any
391 -- front-end warnings when we are getting Alfa output.
393 Reset_Style_Check_Options;
395 -- Suppress compiler warnings, since what we are interested in here
396 -- is what formal verification can find out.
398 Warning_Mode := Suppress;
400 -- Suppress the generation of name tables for enumerations, which are
401 -- not needed for formal verification, and fall outside the Alfa
402 -- subset (use of pointers).
404 Global_Discard_Names := True;
406 -- Suppress the expansion of tagged types and dispatching calls,
407 -- which lead to the generation of non-Alfa code (use of pointers),
408 -- which is more complex to formally verify than the original source.
410 Tagged_Type_Expansion := False;
413 -- Set Configurable_Run_Time mode if system.ads flag set
415 if Targparm.Configurable_Run_Time_On_Target or Debug_Flag_YY then
416 Configurable_Run_Time_Mode := True;
419 -- Set -gnatR3m mode if debug flag A set
421 if Debug_Flag_AA then
422 Back_Annotate_Rep_Info := True;
423 List_Representation_Info := 1;
424 List_Representation_Info_Mechanisms := True;
427 -- Force Target_Strict_Alignment true if debug flag -gnatd.a is set
429 if Debug_Flag_Dot_A then
430 Ttypes.Target_Strict_Alignment := True;
433 -- Increase size of allocated entities if debug flag -gnatd.N is set
435 if Debug_Flag_Dot_NN then
436 Atree.Num_Extension_Nodes := Atree.Num_Extension_Nodes + 1;
439 -- Disable static allocation of dispatch tables if -gnatd.t or if layout
440 -- is enabled. The front end's layout phase currently treats types that
441 -- have discriminant-dependent arrays as not being static even when a
442 -- discriminant constraint on the type is static, and this leads to
443 -- problems with subtypes of type Ada.Tags.Dispatch_Table_Wrapper. ???
445 if Debug_Flag_Dot_T or else Frontend_Layout_On_Target then
446 Static_Dispatch_Tables := False;
449 -- Flip endian mode if -gnatd8 set
452 Ttypes.Bytes_Big_Endian := not Ttypes.Bytes_Big_Endian;
455 -- Deal with forcing OpenVMS switches True if debug flag M is set, but
456 -- record the setting of Targparm.Open_VMS_On_Target in True_VMS_Target
457 -- before doing this, so we know if we are in real OpenVMS or not!
459 Opt.True_VMS_Target := Targparm.OpenVMS_On_Target;
462 Targparm.OpenVMS_On_Target := True;
463 Hostparm.OpenVMS := True;
466 -- Activate front end layout if debug flag -gnatdF is set
468 if Debug_Flag_FF then
469 Targparm.Frontend_Layout_On_Target := True;
472 -- Set and check exception mechanism
474 if Targparm.ZCX_By_Default_On_Target then
475 Exception_Mechanism := Back_End_Exceptions;
478 -- Set proper status for overflow check mechanism
480 -- If already set (by -gnato or above in Alfa or CodePeer mode) then we
481 -- have nothing to do.
483 if Opt.Suppress_Options.Overflow_Mode_General /= Not_Set then
486 -- Otherwise set overflow mode defaults
489 -- Otherwise set overflow checks off by default
491 Suppress_Options.Suppress (Overflow_Check) := True;
493 -- Set appropriate default overflow handling mode. Note: at present
494 -- we set STRICT in all three of the following cases. They are
495 -- separated because in the future we may make different choices.
497 -- By default set STRICT mode if -gnatg in effect
500 Suppress_Options.Overflow_Mode_General := Strict;
501 Suppress_Options.Overflow_Mode_Assertions := Strict;
503 -- If we have backend divide and overflow checks, then by default
504 -- overflow checks are STRICT. Historically this code used to also
505 -- activate overflow checks, although no target currently has these
506 -- flags set, so this was dead code anyway.
508 elsif Targparm.Backend_Divide_Checks_On_Target
510 Targparm.Backend_Overflow_Checks_On_Target
512 Suppress_Options.Overflow_Mode_General := Strict;
513 Suppress_Options.Overflow_Mode_Assertions := Strict;
515 -- Otherwise for now, default is STRICT mode. This may change in the
516 -- future, but for now this is the compatible behavior with previous
520 Suppress_Options.Overflow_Mode_General := Strict;
521 Suppress_Options.Overflow_Mode_Assertions := Strict;
525 -- Set default for atomic synchronization. As this synchronization
526 -- between atomic accesses can be expensive, and not typically needed
527 -- on some targets, an optional target parameter can turn the option
528 -- off. Note Atomic Synchronization is implemented as check.
530 Suppress_Options.Suppress (Atomic_Synchronization) :=
531 not Atomic_Sync_Default_On_Target;
533 -- Set switch indicating if we can use N_Expression_With_Actions
535 -- Debug flag -gnatd.X decisively sets usage on
537 if Debug_Flag_Dot_XX then
538 Use_Expression_With_Actions := True;
540 -- Debug flag -gnatd.Y decisively sets usage off
542 elsif Debug_Flag_Dot_YY then
543 Use_Expression_With_Actions := False;
545 -- Otherwise this feature is implemented, so we allow its use
548 Use_Expression_With_Actions := True;
551 -- Set switch indicating if back end can handle limited types, and
552 -- guarantee that no incorrect copies are made (e.g. in the context
553 -- of an if or case expression).
555 -- Debug flag -gnatd.L decisively sets usage on
557 if Debug_Flag_Dot_LL then
558 Back_End_Handles_Limited_Types := True;
560 -- If no debug flag, usage off for AAMP, VM, SCIL cases
563 or else VM_Target /= No_VM
564 or else Generate_SCIL
566 Back_End_Handles_Limited_Types := False;
568 -- Otherwise normal gcc back end, for now still turn flag off by
569 -- default, since there are unresolved problems in the front end.
572 Back_End_Handles_Limited_Types := False;
575 -- If the inlining level has not been set by the user, compute it from
576 -- the optimization level: 1 at -O1/-O2 (and -Os), 2 at -O3 and above.
578 if Inline_Level = 0 then
579 if Optimization_Level < 3 then
586 -- Finally capture adjusted value of Suppress_Options as the initial
587 -- value for Scope_Suppress, which will be modified as we move from
588 -- scope to scope (by Suppress/Unsuppress/Overflow_Checks pragmas).
590 Sem.Scope_Suppress := Opt.Suppress_Options;
591 end Adjust_Global_Switches;
597 procedure Check_Bad_Body is
598 Sname : Unit_Name_Type;
599 Src_Ind : Source_File_Index;
600 Fname : File_Name_Type;
602 procedure Bad_Body_Error (Msg : String);
603 -- Issue message for bad body found
609 procedure Bad_Body_Error (Msg : String) is
611 Error_Msg_N (Msg, Main_Unit_Node);
612 Error_Msg_File_1 := Fname;
613 Error_Msg_N ("remove incorrect body in file{!", Main_Unit_Node);
616 -- Start of processing for Check_Bad_Body
619 -- Nothing to do if we are only checking syntax, because we don't know
620 -- enough to know if we require or forbid a body in this case.
622 if Operating_Mode = Check_Syntax then
626 -- Check for body not allowed
628 if (Main_Kind = N_Package_Declaration
629 and then not Body_Required (Main_Unit_Node))
630 or else (Main_Kind = N_Generic_Package_Declaration
631 and then not Body_Required (Main_Unit_Node))
632 or else Main_Kind = N_Package_Renaming_Declaration
633 or else Main_Kind = N_Subprogram_Renaming_Declaration
634 or else Nkind (Original_Node (Unit (Main_Unit_Node)))
635 in N_Generic_Instantiation
637 Sname := Unit_Name (Main_Unit);
639 -- If we do not already have a body name, then get the body name
640 -- (but how can we have a body name here???)
642 if not Is_Body_Name (Sname) then
643 Sname := Get_Body_Name (Sname);
646 Fname := Get_File_Name (Sname, Subunit => False);
647 Src_Ind := Load_Source_File (Fname);
649 -- Case where body is present and it is not a subunit. Exclude the
650 -- subunit case, because it has nothing to do with the package we are
651 -- compiling. It is illegal for a child unit and a subunit with the
652 -- same expanded name (RM 10.2(9)) to appear together in a partition,
653 -- but there is nothing to stop a compilation environment from having
654 -- both, and the test here simply allows that. If there is an attempt
655 -- to include both in a partition, this is diagnosed at bind time. In
656 -- Ada 83 mode this is not a warning case.
658 -- Note: if weird file names are being used, we can have a situation
659 -- where the file name that supposedly contains body in fact contains
660 -- a spec, or we can't tell what it contains. Skip the error message
663 -- Also ignore body that is nothing but pragma No_Body; (that's the
664 -- whole point of this pragma, to be used this way and to cause the
665 -- body file to be ignored in this context).
667 if Src_Ind /= No_Source_File
668 and then Get_Expected_Unit_Type (Fname) = Expect_Body
669 and then not Source_File_Is_Subunit (Src_Ind)
670 and then not Source_File_Is_No_Body (Src_Ind)
672 Errout.Finalize (Last_Call => False);
674 Error_Msg_Unit_1 := Sname;
676 -- Ada 83 case of a package body being ignored. This is not an
677 -- error as far as the Ada 83 RM is concerned, but it is almost
678 -- certainly not what is wanted so output a warning. Give this
679 -- message only if there were no errors, since otherwise it may
680 -- be incorrect (we may have misinterpreted a junk spec as not
681 -- needing a body when it really does).
683 if Main_Kind = N_Package_Declaration
684 and then Ada_Version = Ada_83
685 and then Operating_Mode = Generate_Code
686 and then Distribution_Stub_Mode /= Generate_Caller_Stub_Body
687 and then not Compilation_Errors
690 ("package $$ does not require a body??", Main_Unit_Node);
691 Error_Msg_File_1 := Fname;
692 Error_Msg_N ("body in file{ will be ignored??", Main_Unit_Node);
694 -- Ada 95 cases of a body file present when no body is
695 -- permitted. This we consider to be an error.
698 -- For generic instantiations, we never allow a body
700 if Nkind (Original_Node (Unit (Main_Unit_Node)))
701 in N_Generic_Instantiation
704 ("generic instantiation for $$ does not allow a body");
706 -- A library unit that is a renaming never allows a body
708 elsif Main_Kind in N_Renaming_Declaration then
710 ("renaming declaration for $$ does not allow a body!");
712 -- Remaining cases are packages and generic packages. Here
713 -- we only do the test if there are no previous errors,
714 -- because if there are errors, they may lead us to
715 -- incorrectly believe that a package does not allow a body
716 -- when in fact it does.
718 elsif not Compilation_Errors then
719 if Main_Kind = N_Package_Declaration then
721 ("package $$ does not allow a body!");
723 elsif Main_Kind = N_Generic_Package_Declaration then
725 ("generic package $$ does not allow a body!");
738 procedure Check_Rep_Info is
740 if List_Representation_Info /= 0
741 or else List_Representation_Info_Mechanisms
746 ("cannot generate representation information, no code generated");
753 -- Start of processing for Gnat1drv
756 -- This inner block is set up to catch assertion errors and constraint
757 -- errors. Since the code for handling these errors can cause another
758 -- exception to be raised (namely Unrecoverable_Error), we need two
759 -- nested blocks, so that the outer one handles unrecoverable error.
762 -- Initialize all packages. For the most part, these initialization
763 -- calls can be made in any order. Exceptions are as follows:
765 -- Lib.Initialize need to be called before Scan_Compiler_Arguments,
766 -- because it initializes a table filled by Scan_Compiler_Arguments.
772 Scan_Compiler_Arguments;
773 Osint.Add_Default_Search_Dirs;
793 Sem_Type.Init_Interp_Tables;
795 -- Acquire target parameters from system.ads (source of package System)
800 S : Source_File_Index;
804 Name_Buffer (1 .. 10) := "system.ads";
807 S := Load_Source_File (N);
809 if S = No_Source_File then
811 ("fatal error, run-time library not installed correctly");
812 Write_Line ("cannot locate file system.ads");
813 raise Unrecoverable_Error;
815 -- Remember source index of system.ads (which was read successfully)
818 System_Source_File_Index := S;
821 Targparm.Get_Target_Parameters
822 (System_Text => Source_Text (S),
823 Source_First => Source_First (S),
824 Source_Last => Source_Last (S));
826 -- Acquire configuration pragma information from Targparm
828 Restrict.Restrictions := Targparm.Restrictions_On_Target;
831 Adjust_Global_Switches;
833 -- Output copyright notice if full list mode unless we have a list
834 -- file, in which case we defer this so that it is output in the file
836 if (Verbose_Mode or else (Full_List and then Full_List_File_Name = null))
837 and then not Debug_Flag_7
841 Write_Str (Gnat_Version_String);
843 Write_Str ("Copyright 1992-" & Current_Year
844 & ", Free Software Foundation, Inc.");
848 -- Check we do not have more than one source file, this happens only in
849 -- the case where the driver is called directly, it cannot happen when
850 -- gnat1 is invoked from gcc in the normal case.
852 if Osint.Number_Of_Files /= 1 then
855 Osint.Fail ("you must provide one source file");
857 elsif Usage_Requested then
861 Original_Operating_Mode := Operating_Mode;
864 -- Exit with errors if the main source could not be parsed. Also, when
865 -- -gnatd.H is present, the source file is not set.
867 if Sinput.Main_Source_File = No_Source_File then
869 -- Handle -gnatd.H debug mode
871 if Debug_Flag_Dot_HH then
873 -- For -gnatd.H, lock all the tables to keep the convention that
874 -- the backend needs to unlock the tables it wants to touch.
887 -- And all we need to do is to call the back end
889 Back_End.Call_Back_End (Back_End.Generate_Object);
892 Errout.Finalize (Last_Call => True);
893 Errout.Output_Messages;
894 Exit_Program (E_Errors);
897 Main_Unit_Node := Cunit (Main_Unit);
898 Main_Kind := Nkind (Unit (Main_Unit_Node));
901 -- In CodePeer mode we always delete old SCIL files before regenerating
902 -- new ones, in case of e.g. errors, and also to remove obsolete scilx
903 -- files generated by CodePeer itself.
905 if CodePeer_Mode then
906 Comperr.Delete_SCIL_Files;
909 -- Exit if compilation errors detected
911 Errout.Finalize (Last_Call => False);
913 if Compilation_Errors then
915 Sem_Ch13.Validate_Unchecked_Conversions;
916 Sem_Ch13.Validate_Address_Clauses;
917 Sem_Ch13.Validate_Independence;
918 Errout.Output_Messages;
921 -- Generate ALI file if specially requested
923 if Opt.Force_ALI_Tree_File then
924 Write_ALI (Object => False);
928 Errout.Finalize (Last_Call => True);
929 Exit_Program (E_Errors);
932 -- Set Generate_Code on main unit and its spec. We do this even if are
933 -- not generating code, since Lib-Writ uses this to determine which
934 -- units get written in the ali file.
936 Set_Generate_Code (Main_Unit);
938 -- If we have a corresponding spec, and it comes from source or it is
939 -- not a generated spec for a child subprogram body, then we need object
940 -- code for the spec unit as well.
942 if Nkind (Unit (Main_Unit_Node)) in N_Unit_Body
943 and then not Acts_As_Spec (Main_Unit_Node)
945 if Nkind (Unit (Main_Unit_Node)) = N_Subprogram_Body
946 and then not Comes_From_Source (Library_Unit (Main_Unit_Node))
951 (Get_Cunit_Unit_Number (Library_Unit (Main_Unit_Node)));
955 -- Case of no code required to be generated, exit indicating no error
957 if Original_Operating_Mode = Check_Syntax then
959 Errout.Finalize (Last_Call => True);
960 Errout.Output_Messages;
965 -- Use a goto instead of calling Exit_Program so that finalization
970 elsif Original_Operating_Mode = Check_Semantics then
971 Back_End_Mode := Declarations_Only;
973 -- All remaining cases are cases in which the user requested that code
974 -- be generated (i.e. no -gnatc or -gnats switch was used). Check if we
975 -- can in fact satisfy this request.
977 -- Cannot generate code if someone has turned off code generation for
978 -- any reason at all. We will try to figure out a reason below.
980 elsif Operating_Mode /= Generate_Code then
981 Back_End_Mode := Skip;
983 -- We can generate code for a subprogram body unless there were missing
984 -- subunits. Note that we always generate code for all generic units (a
985 -- change from some previous versions of GNAT).
987 elsif Main_Kind = N_Subprogram_Body and then not Subunits_Missing then
988 Back_End_Mode := Generate_Object;
990 -- We can generate code for a package body unless there are subunits
991 -- missing (note that we always generate code for generic units, which
992 -- is a change from some earlier versions of GNAT).
994 elsif Main_Kind = N_Package_Body and then not Subunits_Missing then
995 Back_End_Mode := Generate_Object;
997 -- We can generate code for a package declaration or a subprogram
998 -- declaration only if it does not required a body.
1000 elsif Nkind_In (Main_Kind,
1001 N_Package_Declaration,
1002 N_Subprogram_Declaration)
1004 (not Body_Required (Main_Unit_Node)
1006 Distribution_Stub_Mode = Generate_Caller_Stub_Body)
1008 Back_End_Mode := Generate_Object;
1010 -- We can generate code for a generic package declaration of a generic
1011 -- subprogram declaration only if does not require a body.
1013 elsif Nkind_In (Main_Kind, N_Generic_Package_Declaration,
1014 N_Generic_Subprogram_Declaration)
1015 and then not Body_Required (Main_Unit_Node)
1017 Back_End_Mode := Generate_Object;
1019 -- Compilation units that are renamings do not require bodies, so we can
1020 -- generate code for them.
1022 elsif Nkind_In (Main_Kind, N_Package_Renaming_Declaration,
1023 N_Subprogram_Renaming_Declaration)
1025 Back_End_Mode := Generate_Object;
1027 -- Compilation units that are generic renamings do not require bodies
1028 -- so we can generate code for them.
1030 elsif Main_Kind in N_Generic_Renaming_Declaration then
1031 Back_End_Mode := Generate_Object;
1033 -- It's not an error to generate SCIL for e.g. a spec which has a body
1035 elsif CodePeer_Mode then
1036 Back_End_Mode := Generate_Object;
1038 -- In all other cases (specs which have bodies, generics, and bodies
1039 -- where subunits are missing), we cannot generate code and we generate
1040 -- a warning message. Note that generic instantiations are gone at this
1041 -- stage since they have been replaced by their instances.
1044 Back_End_Mode := Skip;
1047 -- At this stage Back_End_Mode is set to indicate if the backend should
1048 -- be called to generate code. If it is Skip, then code generation has
1049 -- been turned off, even though code was requested by the original
1050 -- command. This is not an error from the user point of view, but it is
1051 -- an error from the point of view of the gcc driver, so we must exit
1052 -- with an error status.
1054 -- We generate an informative message (from the gcc point of view, it
1055 -- is an error message, but from the users point of view this is not an
1056 -- error, just a consequence of compiling something that cannot
1059 if Back_End_Mode = Skip then
1061 Write_Str ("cannot generate code for ");
1062 Write_Str ("file ");
1063 Write_Name (Unit_File_Name (Main_Unit));
1065 if Subunits_Missing then
1066 Write_Str (" (missing subunits)");
1069 -- Force generation of ALI file, for backward compatibility
1071 Opt.Force_ALI_Tree_File := True;
1073 elsif Main_Kind = N_Subunit then
1074 Write_Str (" (subunit)");
1077 -- Force generation of ALI file, for backward compatibility
1079 Opt.Force_ALI_Tree_File := True;
1081 elsif Main_Kind = N_Subprogram_Declaration then
1082 Write_Str (" (subprogram spec)");
1085 -- Generic package body in GNAT implementation mode
1087 elsif Main_Kind = N_Package_Body and then GNAT_Mode then
1088 Write_Str (" (predefined generic)");
1091 -- Force generation of ALI file, for backward compatibility
1093 Opt.Force_ALI_Tree_File := True;
1095 -- Only other case is a package spec
1098 Write_Str (" (package spec)");
1102 Set_Standard_Output;
1104 Sem_Ch13.Validate_Unchecked_Conversions;
1105 Sem_Ch13.Validate_Address_Clauses;
1106 Sem_Ch13.Validate_Independence;
1107 Errout.Finalize (Last_Call => True);
1108 Errout.Output_Messages;
1112 -- Generate ALI file if specially requested, or for missing subunits,
1113 -- subunits or predefined generic.
1115 if Opt.Force_ALI_Tree_File then
1116 Write_ALI (Object => False);
1122 -- Exit program with error indication, to kill object file
1124 Exit_Program (E_No_Code);
1127 -- In -gnatc mode, we only do annotation if -gnatt or -gnatR is also set
1128 -- as indicated by Back_Annotate_Rep_Info being set to True.
1130 -- We don't call for annotations on a subunit, because to process those
1131 -- the back-end requires that the parent(s) be properly compiled.
1133 -- Annotation is suppressed for targets where front-end layout is
1134 -- enabled, because the front end determines representations.
1136 -- Annotation is also suppressed in the case of compiling for a VM,
1137 -- since representations are largely symbolic there.
1139 if Back_End_Mode = Declarations_Only
1140 and then (not (Back_Annotate_Rep_Info or Generate_SCIL)
1141 or else Main_Kind = N_Subunit
1142 or else Targparm.Frontend_Layout_On_Target
1143 or else Targparm.VM_Target /= No_VM)
1145 Sem_Ch13.Validate_Unchecked_Conversions;
1146 Sem_Ch13.Validate_Address_Clauses;
1147 Sem_Ch13.Validate_Independence;
1148 Errout.Finalize (Last_Call => True);
1149 Errout.Output_Messages;
1150 Write_ALI (Object => False);
1158 -- Ensure that we properly register a dependency on system.ads, since
1159 -- even if we do not semantically depend on this, Targparm has read
1160 -- system parameters from the system.ads file.
1162 Lib.Writ.Ensure_System_Dependency;
1164 -- Add dependencies, if any, on preprocessing data file and on
1165 -- preprocessing definition file(s).
1167 Prepcomp.Add_Dependencies;
1169 -- Back end needs to explicitly unlock tables it needs to touch
1182 -- Here we call the back end to generate the output code
1184 Generating_Code := True;
1185 Back_End.Call_Back_End (Back_End_Mode);
1187 -- Once the backend is complete, we unlock the names table. This call
1188 -- allows a few extra entries, needed for example for the file name for
1189 -- the library file output.
1193 -- Generate the call-graph output of dispatching calls
1195 Exp_CG.Generate_CG_Output;
1197 -- Validate unchecked conversions (using the values for size and
1198 -- alignment annotated by the backend where possible).
1200 Sem_Ch13.Validate_Unchecked_Conversions;
1202 -- Validate address clauses (again using alignment values annotated
1203 -- by the backend where possible).
1205 Sem_Ch13.Validate_Address_Clauses;
1207 -- Validate independence pragmas (again using values annotated by
1208 -- the back end for component layout etc.)
1210 Sem_Ch13.Validate_Independence;
1212 -- Now we complete output of errors, rep info and the tree info. These
1213 -- are delayed till now, since it is perfectly possible for gigi to
1214 -- generate errors, modify the tree (in particular by setting flags
1215 -- indicating that elaboration is required, and also to back annotate
1216 -- representation information for List_Rep_Info.
1218 Errout.Finalize (Last_Call => True);
1219 Errout.Output_Messages;
1223 -- Only write the library if the backend did not generate any error
1224 -- messages. Otherwise signal errors to the driver program so that
1225 -- there will be no attempt to generate an object file.
1227 if Compilation_Errors then
1229 Exit_Program (E_Errors);
1232 Write_ALI (Object => (Back_End_Mode = Generate_Object));
1234 if not Compilation_Errors then
1236 -- In case of ada backends, we need to make sure that the generated
1237 -- object file has a timestamp greater than the ALI file. We do this
1238 -- to make gnatmake happy when checking the ALI and obj timestamps,
1239 -- where it expects the object file being written after the ali file.
1241 -- Gnatmake's assumption is true for gcc platforms where the gcc
1242 -- wrapper needs to call the assembler after calling gnat1, but is
1243 -- not true for ada backends, where the object files are created
1244 -- directly by gnat1 (so are created before the ali file).
1246 Back_End.Gen_Or_Update_Object_File;
1249 -- Generate ASIS tree after writing the ALI file, since in ASIS mode,
1250 -- Write_ALI may in fact result in further tree decoration from the
1251 -- original tree file. Note that we dump the tree just before generating
1252 -- it, so that the dump will exactly reflect what is written out.
1257 -- Finalize name table and we are all done
1262 -- Handle fatal internal compiler errors
1264 when Rtsfind.RE_Not_Available =>
1265 Comperr.Compiler_Abort ("RE_Not_Available");
1267 when System.Assertions.Assert_Failure =>
1268 Comperr.Compiler_Abort ("Assert_Failure");
1270 when Constraint_Error =>
1271 Comperr.Compiler_Abort ("Constraint_Error");
1273 when Program_Error =>
1274 Comperr.Compiler_Abort ("Program_Error");
1276 when Storage_Error =>
1278 -- Assume this is a bug. If it is real, the message will in any case
1279 -- say Storage_Error, giving a strong hint!
1281 Comperr.Compiler_Abort ("Storage_Error");
1287 -- The outer exception handles an unrecoverable error
1290 when Unrecoverable_Error =>
1291 Errout.Finalize (Last_Call => True);
1292 Errout.Output_Messages;
1295 Write_Str ("compilation abandoned");
1298 Set_Standard_Output;
1301 Exit_Program (E_Errors);