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. This
205 -- prevents suppressing of overflow checks by default, in code down
208 if Suppress_Options.Overflow_Mode_General = Not_Set then
209 Suppress_Options.Overflow_Mode_General := Strict;
210 Suppress_Options.Overflow_Mode_Assertions := Strict;
213 -- CodePeer handles division and overflow checks directly, based on
214 -- the marks set by the frontend, hence no special expansion should
215 -- be performed in the frontend for division and overflow checks.
217 Backend_Divide_Checks_On_Target := True;
218 Backend_Overflow_Checks_On_Target := True;
220 -- Kill debug of generated code, since it messes up sloc values
222 Debug_Generated_Code := False;
224 -- Turn cross-referencing on in case it was disabled (e.g. by -gnatD)
225 -- Do we really need to spend time generating xref in CodePeer
226 -- mode??? Consider setting Xref_Active to False.
230 -- Polling mode forced off, since it generates confusing junk
232 Polling_Required := False;
234 -- Set operating mode to Generate_Code to benefit from full front-end
235 -- expansion (e.g. generics).
237 Operating_Mode := Generate_Code;
239 -- We need SCIL generation of course
241 Generate_SCIL := True;
243 -- Enable assertions and debug pragmas, since they give CodePeer
244 -- valuable extra information.
246 Assertions_Enabled := True;
247 Debug_Pragmas_Enabled := True;
249 -- Disable all simple value propagation. This is an optimization
250 -- which is valuable for code optimization, and also for generation
251 -- of compiler warnings, but these are being turned off by default,
252 -- and CodePeer generates better messages (referencing original
253 -- variables) this way.
255 Debug_Flag_MM := True;
257 -- Set normal RM validity checking, and checking of IN OUT parameters
258 -- (this might give CodePeer more useful checks to analyze, to be
259 -- confirmed???). All other validity checking is turned off, since
260 -- this can generate very complex trees that only confuse CodePeer
261 -- and do not bring enough useful info.
263 Reset_Validity_Check_Options;
264 Validity_Check_Default := True;
265 Validity_Check_In_Out_Params := True;
266 Validity_Check_In_Params := True;
268 -- Turn off style check options since we are not interested in any
269 -- front-end warnings when we are getting CodePeer output.
271 Reset_Style_Check_Options;
273 -- Always perform semantics and generate ali files in CodePeer mode,
274 -- so that a gnatmake -c -k will proceed further when possible.
276 Force_ALI_Tree_File := True;
277 Try_Semantics := True;
280 -- Set switches for formal verification mode
282 if Debug_Flag_Dot_VV then
283 Formal_Extensions := True;
286 if Debug_Flag_Dot_FF then
289 -- Set strict standard interpretation of compiler permissions
291 if Debug_Flag_Dot_DD then
292 Strict_Alfa_Mode := True;
295 -- Turn off inlining, which would confuse formal verification output
298 Front_End_Inlining := False;
299 Inline_Active := False;
301 -- Disable front-end optimizations, to keep the tree as close to the
302 -- source code as possible, and also to avoid inconsistencies between
303 -- trees when using different optimization switches.
305 Optimization_Level := 0;
307 -- Enable some restrictions systematically to simplify the generated
308 -- code (and ease analysis). Note that restriction checks are also
309 -- disabled in Alfa mode, see Restrict.Check_Restriction, and user
310 -- specified Restrictions pragmas are ignored, see
311 -- Sem_Prag.Process_Restrictions_Or_Restriction_Warnings.
313 Restrict.Restrictions.Set (No_Initialize_Scalars) := True;
315 -- Note: at this point we used to suppress various checks, but that
316 -- is not what we want. We need the semantic processing for these
317 -- checks (which will set flags like Do_Overflow_Check, showing the
318 -- points at which potential checks are required semantically). We
319 -- don't want the expansion associated with these checks, but that
320 -- happens anyway because this expansion is simply not done in the
321 -- Alfa version of the expander.
323 -- Turn off dynamic elaboration checks: generates inconsistencies in
324 -- trees between specs compiled as part of a main unit or as part of
327 Dynamic_Elaboration_Checks := False;
329 -- Set STRICT mode for overflow checks if not set explicitly. This
330 -- prevents suppressing of overflow checks by default, in code down
333 if Suppress_Options.Overflow_Mode_General = Not_Set then
334 Suppress_Options.Overflow_Mode_General := Strict;
335 Suppress_Options.Overflow_Mode_Assertions := Strict;
338 -- Kill debug of generated code, since it messes up sloc values
340 Debug_Generated_Code := False;
342 -- Turn cross-referencing on in case it was disabled (e.g. by -gnatD)
343 -- as it is needed for computing effects of subprograms in the formal
344 -- verification backend.
348 -- Polling mode forced off, since it generates confusing junk
350 Polling_Required := False;
352 -- Set operating mode to Generate_Code, but full front-end expansion
353 -- is not desirable in Alfa mode, so a light expansion is performed
356 Operating_Mode := Generate_Code;
360 Debug_Flag_HH := True;
362 -- Disable Expressions_With_Actions nodes
364 -- The gnat2why backend does not deal with Expressions_With_Actions
365 -- in all places (in particular assertions). It is difficult to
366 -- determine in the frontend which cases are allowed, so we disable
367 -- Expressions_With_Actions entirely. Even in the cases where
368 -- gnat2why deals with Expressions_With_Actions, it is easier to
369 -- deal with the original constructs (quantified, conditional and
370 -- case expressions) instead of the rewritten ones.
372 Use_Expression_With_Actions := False;
374 -- Enable assertions and debug pragmas, since they give valuable
375 -- extra information for formal verification.
377 Assertions_Enabled := True;
378 Debug_Pragmas_Enabled := True;
380 -- Turn off style check options since we are not interested in any
381 -- front-end warnings when we are getting Alfa output.
383 Reset_Style_Check_Options;
385 -- Suppress compiler warnings, since what we are interested in here
386 -- is what formal verification can find out.
388 Warning_Mode := Suppress;
390 -- Suppress the generation of name tables for enumerations, which are
391 -- not needed for formal verification, and fall outside the Alfa
392 -- subset (use of pointers).
394 Global_Discard_Names := True;
396 -- Suppress the expansion of tagged types and dispatching calls,
397 -- which lead to the generation of non-Alfa code (use of pointers),
398 -- which is more complex to formally verify than the original source.
400 Tagged_Type_Expansion := False;
403 -- Set Configurable_Run_Time mode if system.ads flag set
405 if Targparm.Configurable_Run_Time_On_Target or Debug_Flag_YY then
406 Configurable_Run_Time_Mode := True;
409 -- Set -gnatR3m mode if debug flag A set
411 if Debug_Flag_AA then
412 Back_Annotate_Rep_Info := True;
413 List_Representation_Info := 1;
414 List_Representation_Info_Mechanisms := True;
417 -- Force Target_Strict_Alignment true if debug flag -gnatd.a is set
419 if Debug_Flag_Dot_A then
420 Ttypes.Target_Strict_Alignment := True;
423 -- Increase size of allocated entities if debug flag -gnatd.N is set
425 if Debug_Flag_Dot_NN then
426 Atree.Num_Extension_Nodes := Atree.Num_Extension_Nodes + 1;
429 -- Disable static allocation of dispatch tables if -gnatd.t or if layout
430 -- is enabled. The front end's layout phase currently treats types that
431 -- have discriminant-dependent arrays as not being static even when a
432 -- discriminant constraint on the type is static, and this leads to
433 -- problems with subtypes of type Ada.Tags.Dispatch_Table_Wrapper. ???
435 if Debug_Flag_Dot_T or else Frontend_Layout_On_Target then
436 Static_Dispatch_Tables := False;
439 -- Flip endian mode if -gnatd8 set
442 Ttypes.Bytes_Big_Endian := not Ttypes.Bytes_Big_Endian;
445 -- Deal with forcing OpenVMS switches True if debug flag M is set, but
446 -- record the setting of Targparm.Open_VMS_On_Target in True_VMS_Target
447 -- before doing this, so we know if we are in real OpenVMS or not!
449 Opt.True_VMS_Target := Targparm.OpenVMS_On_Target;
452 Targparm.OpenVMS_On_Target := True;
453 Hostparm.OpenVMS := True;
456 -- Activate front end layout if debug flag -gnatdF is set
458 if Debug_Flag_FF then
459 Targparm.Frontend_Layout_On_Target := True;
462 -- Set and check exception mechanism
464 if Targparm.ZCX_By_Default_On_Target then
465 Exception_Mechanism := Back_End_Exceptions;
468 -- Set proper status for overflow check mechanism
470 -- If already set (by -gnato or above in Alfa or CodePeer mode) then we
471 -- have nothing to do.
473 if Opt.Suppress_Options.Overflow_Mode_General /= Not_Set then
476 -- Otherwise set overflow mode defaults
479 -- Otherwise set overflow checks off by default
481 Suppress_Options.Suppress (Overflow_Check) := True;
483 -- Set appropriate default overflow handling mode. Note: at present
484 -- we set STRICT in all three of the following cases. They are
485 -- separated because in the future we may make different choices.
487 -- By default set STRICT mode if -gnatg in effect
490 Suppress_Options.Overflow_Mode_General := Strict;
491 Suppress_Options.Overflow_Mode_Assertions := Strict;
493 -- If we have backend divide and overflow checks, then by default
494 -- overflow checks are STRICT. Historically this code used to also
495 -- activate overflow checks, although no target currently has these
496 -- flags set, so this was dead code anyway.
498 elsif Targparm.Backend_Divide_Checks_On_Target
500 Targparm.Backend_Overflow_Checks_On_Target
502 Suppress_Options.Overflow_Mode_General := Strict;
503 Suppress_Options.Overflow_Mode_Assertions := Strict;
505 -- Otherwise for now, default is STRICT mode. This may change in the
506 -- future, but for now this is the compatible behavior with previous
510 Suppress_Options.Overflow_Mode_General := Strict;
511 Suppress_Options.Overflow_Mode_Assertions := Strict;
515 -- Set default for atomic synchronization. As this synchronization
516 -- between atomic accesses can be expensive, and not typically needed
517 -- on some targets, an optional target parameter can turn the option
518 -- off. Note Atomic Synchronization is implemented as check.
520 Suppress_Options.Suppress (Atomic_Synchronization) :=
521 not Atomic_Sync_Default_On_Target;
523 -- Set switch indicating if we can use N_Expression_With_Actions
525 -- Debug flag -gnatd.X decisively sets usage on
527 if Debug_Flag_Dot_XX then
528 Use_Expression_With_Actions := True;
530 -- Debug flag -gnatd.Y decisively sets usage off
532 elsif Debug_Flag_Dot_YY then
533 Use_Expression_With_Actions := False;
535 -- Otherwise this feature is implemented, so we allow its use
538 Use_Expression_With_Actions := True;
541 -- Set switch indicating if back end can handle limited types, and
542 -- guarantee that no incorrect copies are made (e.g. in the context
543 -- of an if or case expression).
545 -- Debug flag -gnatd.L decisively sets usage on
547 if Debug_Flag_Dot_LL then
548 Back_End_Handles_Limited_Types := True;
550 -- If no debug flag, usage off for AAMP, VM, SCIL cases
553 or else VM_Target /= No_VM
554 or else Generate_SCIL
556 Back_End_Handles_Limited_Types := False;
558 -- Otherwise normal gcc back end, for now still turn flag off by
559 -- default, since there are unresolved problems in the front end.
562 Back_End_Handles_Limited_Types := False;
565 -- If the inlining level has not been set by the user, compute it from
566 -- the optimization level: 1 at -O1/-O2 (and -Os), 2 at -O3 and above.
568 if Inline_Level = 0 then
569 if Optimization_Level < 3 then
576 -- Finally capture adjusted value of Suppress_Options as the initial
577 -- value for Scope_Suppress, which will be modified as we move from
578 -- scope to scope (by Suppress/Unsuppress/Overflow_Checks pragmas).
580 Sem.Scope_Suppress := Opt.Suppress_Options;
581 end Adjust_Global_Switches;
587 procedure Check_Bad_Body is
588 Sname : Unit_Name_Type;
589 Src_Ind : Source_File_Index;
590 Fname : File_Name_Type;
592 procedure Bad_Body_Error (Msg : String);
593 -- Issue message for bad body found
599 procedure Bad_Body_Error (Msg : String) is
601 Error_Msg_N (Msg, Main_Unit_Node);
602 Error_Msg_File_1 := Fname;
603 Error_Msg_N ("remove incorrect body in file{!", Main_Unit_Node);
606 -- Start of processing for Check_Bad_Body
609 -- Nothing to do if we are only checking syntax, because we don't know
610 -- enough to know if we require or forbid a body in this case.
612 if Operating_Mode = Check_Syntax then
616 -- Check for body not allowed
618 if (Main_Kind = N_Package_Declaration
619 and then not Body_Required (Main_Unit_Node))
620 or else (Main_Kind = N_Generic_Package_Declaration
621 and then not Body_Required (Main_Unit_Node))
622 or else Main_Kind = N_Package_Renaming_Declaration
623 or else Main_Kind = N_Subprogram_Renaming_Declaration
624 or else Nkind (Original_Node (Unit (Main_Unit_Node)))
625 in N_Generic_Instantiation
627 Sname := Unit_Name (Main_Unit);
629 -- If we do not already have a body name, then get the body name
630 -- (but how can we have a body name here???)
632 if not Is_Body_Name (Sname) then
633 Sname := Get_Body_Name (Sname);
636 Fname := Get_File_Name (Sname, Subunit => False);
637 Src_Ind := Load_Source_File (Fname);
639 -- Case where body is present and it is not a subunit. Exclude the
640 -- subunit case, because it has nothing to do with the package we are
641 -- compiling. It is illegal for a child unit and a subunit with the
642 -- same expanded name (RM 10.2(9)) to appear together in a partition,
643 -- but there is nothing to stop a compilation environment from having
644 -- both, and the test here simply allows that. If there is an attempt
645 -- to include both in a partition, this is diagnosed at bind time. In
646 -- Ada 83 mode this is not a warning case.
648 -- Note: if weird file names are being used, we can have a situation
649 -- where the file name that supposedly contains body in fact contains
650 -- a spec, or we can't tell what it contains. Skip the error message
653 -- Also ignore body that is nothing but pragma No_Body; (that's the
654 -- whole point of this pragma, to be used this way and to cause the
655 -- body file to be ignored in this context).
657 if Src_Ind /= No_Source_File
658 and then Get_Expected_Unit_Type (Fname) = Expect_Body
659 and then not Source_File_Is_Subunit (Src_Ind)
660 and then not Source_File_Is_No_Body (Src_Ind)
662 Errout.Finalize (Last_Call => False);
664 Error_Msg_Unit_1 := Sname;
666 -- Ada 83 case of a package body being ignored. This is not an
667 -- error as far as the Ada 83 RM is concerned, but it is almost
668 -- certainly not what is wanted so output a warning. Give this
669 -- message only if there were no errors, since otherwise it may
670 -- be incorrect (we may have misinterpreted a junk spec as not
671 -- needing a body when it really does).
673 if Main_Kind = N_Package_Declaration
674 and then Ada_Version = Ada_83
675 and then Operating_Mode = Generate_Code
676 and then Distribution_Stub_Mode /= Generate_Caller_Stub_Body
677 and then not Compilation_Errors
680 ("package $$ does not require a body??", Main_Unit_Node);
681 Error_Msg_File_1 := Fname;
682 Error_Msg_N ("body in file{ will be ignored??", Main_Unit_Node);
684 -- Ada 95 cases of a body file present when no body is
685 -- permitted. This we consider to be an error.
688 -- For generic instantiations, we never allow a body
690 if Nkind (Original_Node (Unit (Main_Unit_Node)))
691 in N_Generic_Instantiation
694 ("generic instantiation for $$ does not allow a body");
696 -- A library unit that is a renaming never allows a body
698 elsif Main_Kind in N_Renaming_Declaration then
700 ("renaming declaration for $$ does not allow a body!");
702 -- Remaining cases are packages and generic packages. Here
703 -- we only do the test if there are no previous errors,
704 -- because if there are errors, they may lead us to
705 -- incorrectly believe that a package does not allow a body
706 -- when in fact it does.
708 elsif not Compilation_Errors then
709 if Main_Kind = N_Package_Declaration then
711 ("package $$ does not allow a body!");
713 elsif Main_Kind = N_Generic_Package_Declaration then
715 ("generic package $$ does not allow a body!");
728 procedure Check_Rep_Info is
730 if List_Representation_Info /= 0
731 or else List_Representation_Info_Mechanisms
736 ("cannot generate representation information, no code generated");
743 -- Start of processing for Gnat1drv
746 -- This inner block is set up to catch assertion errors and constraint
747 -- errors. Since the code for handling these errors can cause another
748 -- exception to be raised (namely Unrecoverable_Error), we need two
749 -- nested blocks, so that the outer one handles unrecoverable error.
752 -- Initialize all packages. For the most part, these initialization
753 -- calls can be made in any order. Exceptions are as follows:
755 -- Lib.Initialize need to be called before Scan_Compiler_Arguments,
756 -- because it initializes a table filled by Scan_Compiler_Arguments.
762 Scan_Compiler_Arguments;
763 Osint.Add_Default_Search_Dirs;
783 Sem_Type.Init_Interp_Tables;
785 -- Acquire target parameters from system.ads (source of package System)
790 S : Source_File_Index;
794 Name_Buffer (1 .. 10) := "system.ads";
797 S := Load_Source_File (N);
799 if S = No_Source_File then
801 ("fatal error, run-time library not installed correctly");
802 Write_Line ("cannot locate file system.ads");
803 raise Unrecoverable_Error;
805 -- Remember source index of system.ads (which was read successfully)
808 System_Source_File_Index := S;
811 Targparm.Get_Target_Parameters
812 (System_Text => Source_Text (S),
813 Source_First => Source_First (S),
814 Source_Last => Source_Last (S));
816 -- Acquire configuration pragma information from Targparm
818 Restrict.Restrictions := Targparm.Restrictions_On_Target;
821 Adjust_Global_Switches;
823 -- Output copyright notice if full list mode unless we have a list
824 -- file, in which case we defer this so that it is output in the file
826 if (Verbose_Mode or else (Full_List and then Full_List_File_Name = null))
827 and then not Debug_Flag_7
831 Write_Str (Gnat_Version_String);
833 Write_Str ("Copyright 1992-" & Current_Year
834 & ", Free Software Foundation, Inc.");
838 -- Check we do not have more than one source file, this happens only in
839 -- the case where the driver is called directly, it cannot happen when
840 -- gnat1 is invoked from gcc in the normal case.
842 if Osint.Number_Of_Files /= 1 then
845 Osint.Fail ("you must provide one source file");
847 elsif Usage_Requested then
851 Original_Operating_Mode := Operating_Mode;
854 -- Exit with errors if the main source could not be parsed. Also, when
855 -- -gnatd.H is present, the source file is not set.
857 if Sinput.Main_Source_File = No_Source_File then
859 -- Handle -gnatd.H debug mode
861 if Debug_Flag_Dot_HH then
863 -- For -gnatd.H, lock all the tables to keep the convention that
864 -- the backend needs to unlock the tables it wants to touch.
877 -- And all we need to do is to call the back end
879 Back_End.Call_Back_End (Back_End.Generate_Object);
882 Errout.Finalize (Last_Call => True);
883 Errout.Output_Messages;
884 Exit_Program (E_Errors);
887 Main_Unit_Node := Cunit (Main_Unit);
888 Main_Kind := Nkind (Unit (Main_Unit_Node));
891 -- In CodePeer mode we always delete old SCIL files before regenerating
892 -- new ones, in case of e.g. errors, and also to remove obsolete scilx
893 -- files generated by CodePeer itself.
895 if CodePeer_Mode then
896 Comperr.Delete_SCIL_Files;
899 -- Exit if compilation errors detected
901 Errout.Finalize (Last_Call => False);
903 if Compilation_Errors then
905 Sem_Ch13.Validate_Unchecked_Conversions;
906 Sem_Ch13.Validate_Address_Clauses;
907 Sem_Ch13.Validate_Independence;
908 Errout.Output_Messages;
911 -- Generate ALI file if specially requested
913 if Opt.Force_ALI_Tree_File then
914 Write_ALI (Object => False);
918 Errout.Finalize (Last_Call => True);
919 Exit_Program (E_Errors);
922 -- Set Generate_Code on main unit and its spec. We do this even if are
923 -- not generating code, since Lib-Writ uses this to determine which
924 -- units get written in the ali file.
926 Set_Generate_Code (Main_Unit);
928 -- If we have a corresponding spec, and it comes from source or it is
929 -- not a generated spec for a child subprogram body, then we need object
930 -- code for the spec unit as well.
932 if Nkind (Unit (Main_Unit_Node)) in N_Unit_Body
933 and then not Acts_As_Spec (Main_Unit_Node)
935 if Nkind (Unit (Main_Unit_Node)) = N_Subprogram_Body
936 and then not Comes_From_Source (Library_Unit (Main_Unit_Node))
941 (Get_Cunit_Unit_Number (Library_Unit (Main_Unit_Node)));
945 -- Case of no code required to be generated, exit indicating no error
947 if Original_Operating_Mode = Check_Syntax then
949 Errout.Finalize (Last_Call => True);
950 Errout.Output_Messages;
955 -- Use a goto instead of calling Exit_Program so that finalization
960 elsif Original_Operating_Mode = Check_Semantics then
961 Back_End_Mode := Declarations_Only;
963 -- All remaining cases are cases in which the user requested that code
964 -- be generated (i.e. no -gnatc or -gnats switch was used). Check if we
965 -- can in fact satisfy this request.
967 -- Cannot generate code if someone has turned off code generation for
968 -- any reason at all. We will try to figure out a reason below.
970 elsif Operating_Mode /= Generate_Code then
971 Back_End_Mode := Skip;
973 -- We can generate code for a subprogram body unless there were missing
974 -- subunits. Note that we always generate code for all generic units (a
975 -- change from some previous versions of GNAT).
977 elsif Main_Kind = N_Subprogram_Body and then not Subunits_Missing then
978 Back_End_Mode := Generate_Object;
980 -- We can generate code for a package body unless there are subunits
981 -- missing (note that we always generate code for generic units, which
982 -- is a change from some earlier versions of GNAT).
984 elsif Main_Kind = N_Package_Body and then not Subunits_Missing then
985 Back_End_Mode := Generate_Object;
987 -- We can generate code for a package declaration or a subprogram
988 -- declaration only if it does not required a body.
990 elsif Nkind_In (Main_Kind,
991 N_Package_Declaration,
992 N_Subprogram_Declaration)
994 (not Body_Required (Main_Unit_Node)
996 Distribution_Stub_Mode = Generate_Caller_Stub_Body)
998 Back_End_Mode := Generate_Object;
1000 -- We can generate code for a generic package declaration of a generic
1001 -- subprogram declaration only if does not require a body.
1003 elsif Nkind_In (Main_Kind, N_Generic_Package_Declaration,
1004 N_Generic_Subprogram_Declaration)
1005 and then not Body_Required (Main_Unit_Node)
1007 Back_End_Mode := Generate_Object;
1009 -- Compilation units that are renamings do not require bodies, so we can
1010 -- generate code for them.
1012 elsif Nkind_In (Main_Kind, N_Package_Renaming_Declaration,
1013 N_Subprogram_Renaming_Declaration)
1015 Back_End_Mode := Generate_Object;
1017 -- Compilation units that are generic renamings do not require bodies
1018 -- so we can generate code for them.
1020 elsif Main_Kind in N_Generic_Renaming_Declaration then
1021 Back_End_Mode := Generate_Object;
1023 -- It's not an error to generate SCIL for e.g. a spec which has a body
1025 elsif CodePeer_Mode then
1026 Back_End_Mode := Generate_Object;
1028 -- In all other cases (specs which have bodies, generics, and bodies
1029 -- where subunits are missing), we cannot generate code and we generate
1030 -- a warning message. Note that generic instantiations are gone at this
1031 -- stage since they have been replaced by their instances.
1034 Back_End_Mode := Skip;
1037 -- At this stage Back_End_Mode is set to indicate if the backend should
1038 -- be called to generate code. If it is Skip, then code generation has
1039 -- been turned off, even though code was requested by the original
1040 -- command. This is not an error from the user point of view, but it is
1041 -- an error from the point of view of the gcc driver, so we must exit
1042 -- with an error status.
1044 -- We generate an informative message (from the gcc point of view, it
1045 -- is an error message, but from the users point of view this is not an
1046 -- error, just a consequence of compiling something that cannot
1049 if Back_End_Mode = Skip then
1051 Write_Str ("cannot generate code for ");
1052 Write_Str ("file ");
1053 Write_Name (Unit_File_Name (Main_Unit));
1055 if Subunits_Missing then
1056 Write_Str (" (missing subunits)");
1059 -- Force generation of ALI file, for backward compatibility
1061 Opt.Force_ALI_Tree_File := True;
1063 elsif Main_Kind = N_Subunit then
1064 Write_Str (" (subunit)");
1067 -- Force generation of ALI file, for backward compatibility
1069 Opt.Force_ALI_Tree_File := True;
1071 elsif Main_Kind = N_Subprogram_Declaration then
1072 Write_Str (" (subprogram spec)");
1075 -- Generic package body in GNAT implementation mode
1077 elsif Main_Kind = N_Package_Body and then GNAT_Mode then
1078 Write_Str (" (predefined generic)");
1081 -- Force generation of ALI file, for backward compatibility
1083 Opt.Force_ALI_Tree_File := True;
1085 -- Only other case is a package spec
1088 Write_Str (" (package spec)");
1092 Set_Standard_Output;
1094 Sem_Ch13.Validate_Unchecked_Conversions;
1095 Sem_Ch13.Validate_Address_Clauses;
1096 Sem_Ch13.Validate_Independence;
1097 Errout.Finalize (Last_Call => True);
1098 Errout.Output_Messages;
1102 -- Generate ALI file if specially requested, or for missing subunits,
1103 -- subunits or predefined generic.
1105 if Opt.Force_ALI_Tree_File then
1106 Write_ALI (Object => False);
1112 -- Exit program with error indication, to kill object file
1114 Exit_Program (E_No_Code);
1117 -- In -gnatc mode, we only do annotation if -gnatt or -gnatR is also set
1118 -- as indicated by Back_Annotate_Rep_Info being set to True.
1120 -- We don't call for annotations on a subunit, because to process those
1121 -- the back-end requires that the parent(s) be properly compiled.
1123 -- Annotation is suppressed for targets where front-end layout is
1124 -- enabled, because the front end determines representations.
1126 -- Annotation is also suppressed in the case of compiling for a VM,
1127 -- since representations are largely symbolic there.
1129 if Back_End_Mode = Declarations_Only
1130 and then (not (Back_Annotate_Rep_Info or Generate_SCIL)
1131 or else Main_Kind = N_Subunit
1132 or else Targparm.Frontend_Layout_On_Target
1133 or else Targparm.VM_Target /= No_VM)
1135 Sem_Ch13.Validate_Unchecked_Conversions;
1136 Sem_Ch13.Validate_Address_Clauses;
1137 Sem_Ch13.Validate_Independence;
1138 Errout.Finalize (Last_Call => True);
1139 Errout.Output_Messages;
1140 Write_ALI (Object => False);
1148 -- Ensure that we properly register a dependency on system.ads, since
1149 -- even if we do not semantically depend on this, Targparm has read
1150 -- system parameters from the system.ads file.
1152 Lib.Writ.Ensure_System_Dependency;
1154 -- Add dependencies, if any, on preprocessing data file and on
1155 -- preprocessing definition file(s).
1157 Prepcomp.Add_Dependencies;
1159 -- Back end needs to explicitly unlock tables it needs to touch
1172 -- Here we call the back end to generate the output code
1174 Generating_Code := True;
1175 Back_End.Call_Back_End (Back_End_Mode);
1177 -- Once the backend is complete, we unlock the names table. This call
1178 -- allows a few extra entries, needed for example for the file name for
1179 -- the library file output.
1183 -- Generate the call-graph output of dispatching calls
1185 Exp_CG.Generate_CG_Output;
1187 -- Validate unchecked conversions (using the values for size and
1188 -- alignment annotated by the backend where possible).
1190 Sem_Ch13.Validate_Unchecked_Conversions;
1192 -- Validate address clauses (again using alignment values annotated
1193 -- by the backend where possible).
1195 Sem_Ch13.Validate_Address_Clauses;
1197 -- Validate independence pragmas (again using values annotated by
1198 -- the back end for component layout etc.)
1200 Sem_Ch13.Validate_Independence;
1202 -- Now we complete output of errors, rep info and the tree info. These
1203 -- are delayed till now, since it is perfectly possible for gigi to
1204 -- generate errors, modify the tree (in particular by setting flags
1205 -- indicating that elaboration is required, and also to back annotate
1206 -- representation information for List_Rep_Info.
1208 Errout.Finalize (Last_Call => True);
1209 Errout.Output_Messages;
1213 -- Only write the library if the backend did not generate any error
1214 -- messages. Otherwise signal errors to the driver program so that
1215 -- there will be no attempt to generate an object file.
1217 if Compilation_Errors then
1219 Exit_Program (E_Errors);
1222 Write_ALI (Object => (Back_End_Mode = Generate_Object));
1224 if not Compilation_Errors then
1226 -- In case of ada backends, we need to make sure that the generated
1227 -- object file has a timestamp greater than the ALI file. We do this
1228 -- to make gnatmake happy when checking the ALI and obj timestamps,
1229 -- where it expects the object file being written after the ali file.
1231 -- Gnatmake's assumption is true for gcc platforms where the gcc
1232 -- wrapper needs to call the assembler after calling gnat1, but is
1233 -- not true for ada backends, where the object files are created
1234 -- directly by gnat1 (so are created before the ali file).
1236 Back_End.Gen_Or_Update_Object_File;
1239 -- Generate ASIS tree after writing the ALI file, since in ASIS mode,
1240 -- Write_ALI may in fact result in further tree decoration from the
1241 -- original tree file. Note that we dump the tree just before generating
1242 -- it, so that the dump will exactly reflect what is written out.
1247 -- Finalize name table and we are all done
1252 -- Handle fatal internal compiler errors
1254 when Rtsfind.RE_Not_Available =>
1255 Comperr.Compiler_Abort ("RE_Not_Available");
1257 when System.Assertions.Assert_Failure =>
1258 Comperr.Compiler_Abort ("Assert_Failure");
1260 when Constraint_Error =>
1261 Comperr.Compiler_Abort ("Constraint_Error");
1263 when Program_Error =>
1264 Comperr.Compiler_Abort ("Program_Error");
1266 when Storage_Error =>
1268 -- Assume this is a bug. If it is real, the message will in any case
1269 -- say Storage_Error, giving a strong hint!
1271 Comperr.Compiler_Abort ("Storage_Error");
1277 -- The outer exception handles an unrecoverable error
1280 when Unrecoverable_Error =>
1281 Errout.Finalize (Last_Call => True);
1282 Errout.Output_Messages;
1285 Write_Str ("compilation abandoned");
1288 Set_Standard_Output;
1291 Exit_Program (E_Errors);