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 procedure Check_Library_Items;
108 -- For debugging -- checks the behavior of Walk_Library_Items
109 pragma Warnings (Off, Check_Library_Items);
110 -- In case the call below is commented out
112 ----------------------------
113 -- Adjust_Global_Switches --
114 ----------------------------
116 procedure Adjust_Global_Switches is
118 -- Debug flag -gnatd.I is a synonym for Generate_SCIL and requires code
122 and then Operating_Mode = Generate_Code
124 Generate_SCIL := True;
127 -- Disable CodePeer_Mode in Check_Syntax, since we need front-end
130 if Operating_Mode = Check_Syntax then
131 CodePeer_Mode := False;
134 -- Set ASIS mode if -gnatt and -gnatc are set
136 if Operating_Mode = Check_Semantics and then Tree_Output then
139 -- Turn off inlining in ASIS mode, since ASIS cannot handle the extra
140 -- information in the trees caused by inlining being active.
142 -- More specifically, the tree seems to be malformed from the ASIS
143 -- point of view if -gnatc and -gnatn appear together???
145 Inline_Active := False;
147 -- Turn off SCIL generation and CodePeer mode in semantics mode,
148 -- since SCIL requires front-end expansion.
150 Generate_SCIL := False;
151 CodePeer_Mode := False;
154 -- SCIL mode needs to disable front-end inlining since the generated
155 -- trees (in particular order and consistency between specs compiled
156 -- as part of a main unit or as part of a with-clause) are causing
159 if Generate_SCIL then
160 Front_End_Inlining := False;
163 -- Tune settings for optimal SCIL generation in CodePeer mode
165 if CodePeer_Mode then
167 -- Turn off inlining, confuses CodePeer output and gains nothing
169 Front_End_Inlining := False;
170 Inline_Active := False;
172 -- Disable front-end optimizations, to keep the tree as close to the
173 -- source code as possible, and also to avoid inconsistencies between
174 -- trees when using different optimization switches.
176 Optimization_Level := 0;
178 -- Enable some restrictions systematically to simplify the generated
179 -- code (and ease analysis). Note that restriction checks are also
180 -- disabled in CodePeer mode, see Restrict.Check_Restriction, and
181 -- user specified Restrictions pragmas are ignored, see
182 -- Sem_Prag.Process_Restrictions_Or_Restriction_Warnings.
184 Restrict.Restrictions.Set (No_Initialize_Scalars) := True;
185 Restrict.Restrictions.Set (No_Task_Hierarchy) := True;
186 Restrict.Restrictions.Set (No_Abort_Statements) := True;
187 Restrict.Restrictions.Set (Max_Asynchronous_Select_Nesting) := True;
188 Restrict.Restrictions.Value (Max_Asynchronous_Select_Nesting) := 0;
190 -- Suppress overflow, division by zero and access checks since they
191 -- are handled implicitly by CodePeer.
193 -- Turn off dynamic elaboration checks: generates inconsistencies in
194 -- trees between specs compiled as part of a main unit or as part of
197 -- Turn off alignment checks: these cannot be proved statically by
198 -- CodePeer and generate false positives.
200 -- Enable all other language checks
203 (Access_Check => True,
204 Alignment_Check => True,
205 Division_Check => True,
206 Elaboration_Check => True,
207 Overflow_Check => True,
209 Enable_Overflow_Checks := False;
210 Dynamic_Elaboration_Checks := False;
212 -- Kill debug of generated code, since it messes up sloc values
214 Debug_Generated_Code := False;
216 -- Turn cross-referencing on in case it was disabled (e.g. by -gnatD)
217 -- Do we really need to spend time generating xref in CodePeer
218 -- mode??? Consider setting Xref_Active to False.
222 -- Polling mode forced off, since it generates confusing junk
224 Polling_Required := False;
226 -- Set operating mode to Generate_Code to benefit from full front-end
227 -- expansion (e.g. generics).
229 Operating_Mode := Generate_Code;
231 -- We need SCIL generation of course
233 Generate_SCIL := True;
235 -- Enable assertions and debug pragmas, since they give CodePeer
236 -- valuable extra information.
238 Assertions_Enabled := True;
239 Debug_Pragmas_Enabled := True;
241 -- Disable all simple value propagation. This is an optimization
242 -- which is valuable for code optimization, and also for generation
243 -- of compiler warnings, but these are being turned off by default,
244 -- and CodePeer generates better messages (referencing original
245 -- variables) this way.
247 Debug_Flag_MM := True;
249 -- Set normal RM validity checking, and checking of IN OUT parameters
250 -- (this might give CodePeer more useful checks to analyze, to be
251 -- confirmed???). All other validity checking is turned off, since
252 -- this can generate very complex trees that only confuse CodePeer
253 -- and do not bring enough useful info.
255 Reset_Validity_Check_Options;
256 Validity_Check_Default := True;
257 Validity_Check_In_Out_Params := True;
258 Validity_Check_In_Params := True;
260 -- Turn off style check options since we are not interested in any
261 -- front-end warnings when we are getting CodePeer output.
263 Reset_Style_Check_Options;
265 -- Always perform semantics and generate ali files in CodePeer mode,
266 -- so that a gnatmake -c -k will proceed further when possible.
268 Force_ALI_Tree_File := True;
269 Try_Semantics := True;
271 -- Enable Exception_Extra_Info for now, to avoid extra messages
272 -- on controlled operations.
273 -- ??? To be revised.
275 Exception_Extra_Info := True;
278 -- Set Configurable_Run_Time mode if system.ads flag set
280 if Targparm.Configurable_Run_Time_On_Target or Debug_Flag_YY then
281 Configurable_Run_Time_Mode := True;
284 -- Set -gnatR3m mode if debug flag A set
286 if Debug_Flag_AA then
287 Back_Annotate_Rep_Info := True;
288 List_Representation_Info := 1;
289 List_Representation_Info_Mechanisms := True;
292 -- Force Target_Strict_Alignment true if debug flag -gnatd.a is set
294 if Debug_Flag_Dot_A then
295 Ttypes.Target_Strict_Alignment := True;
298 -- Increase size of allocated entities if debug flag -gnatd.N is set
300 if Debug_Flag_Dot_NN then
301 Atree.Num_Extension_Nodes := Atree.Num_Extension_Nodes + 1;
304 -- Disable static allocation of dispatch tables if -gnatd.t or if layout
305 -- is enabled. The front end's layout phase currently treats types that
306 -- have discriminant-dependent arrays as not being static even when a
307 -- discriminant constraint on the type is static, and this leads to
308 -- problems with subtypes of type Ada.Tags.Dispatch_Table_Wrapper. ???
310 if Debug_Flag_Dot_T or else Frontend_Layout_On_Target then
311 Static_Dispatch_Tables := False;
314 -- Flip endian mode if -gnatd8 set
317 Ttypes.Bytes_Big_Endian := not Ttypes.Bytes_Big_Endian;
320 -- Deal with forcing OpenVMS switches True if debug flag M is set, but
321 -- record the setting of Targparm.Open_VMS_On_Target in True_VMS_Target
322 -- before doing this, so we know if we are in real OpenVMS or not!
324 Opt.True_VMS_Target := Targparm.OpenVMS_On_Target;
327 Targparm.OpenVMS_On_Target := True;
328 Hostparm.OpenVMS := True;
331 -- Activate front end layout if debug flag -gnatdF is set
333 if Debug_Flag_FF then
334 Targparm.Frontend_Layout_On_Target := True;
337 -- Set and check exception mechanism
339 if Targparm.ZCX_By_Default_On_Target then
340 Exception_Mechanism := Back_End_Exceptions;
343 -- Set proper status for overflow checks. We turn on overflow checks if
344 -- -gnatp was not specified, and either -gnato is set or the back-end
345 -- takes care of overflow checks. Otherwise we suppress overflow checks
346 -- by default (since front end checks are expensive).
348 if not Opt.Suppress_Checks
349 and then (Opt.Enable_Overflow_Checks
351 (Targparm.Backend_Divide_Checks_On_Target
353 Targparm.Backend_Overflow_Checks_On_Target))
355 Suppress_Options (Overflow_Check) := False;
357 Suppress_Options (Overflow_Check) := True;
360 -- Set default for atomic synchronization. As this synchronization
361 -- between atomic accesses can be expensive, and not typically needed
362 -- on some targets, an optional target parameter can turn the option
363 -- off. Note Atomic Synchronization is implemented as check.
365 Suppress_Options (Atomic_Synchronization) := not Atomic_Sync_Default;
367 -- Set switch indicating if we can use N_Expression_With_Actions
369 -- Debug flag -gnatd.X decisively sets usage on
371 if Debug_Flag_Dot_XX then
372 Use_Expression_With_Actions := True;
374 -- Debug flag -gnatd.Y decisively sets usage off
376 elsif Debug_Flag_Dot_YY then
377 Use_Expression_With_Actions := False;
379 -- Otherwise this feature is implemented, so we allow its use
382 Use_Expression_With_Actions := True;
385 -- Set switch indicating if back end can handle limited types, and
386 -- guarantee that no incorrect copies are made (e.g. in the context
387 -- of a conditional expression).
389 -- Debug flag -gnatd.L decisively sets usage on
391 if Debug_Flag_Dot_LL then
392 Back_End_Handles_Limited_Types := True;
394 -- If no debug flag, usage off for AAMP, VM, SCIL cases
397 or else VM_Target /= No_VM
398 or else Generate_SCIL
400 Back_End_Handles_Limited_Types := False;
402 -- Otherwise normal gcc back end, for now still turn flag off by
403 -- default, since there are unresolved problems in the front end.
406 Back_End_Handles_Limited_Types := False;
409 -- Set switches for formal verification mode
411 if Debug_Flag_Dot_FF then
415 -- Set strict standard interpretation of compiler permissions
417 if Debug_Flag_Dot_DD then
418 Strict_Alfa_Mode := True;
421 -- Turn off inlining, which would confuse formal verification output
424 Front_End_Inlining := False;
425 Inline_Active := False;
427 -- Disable front-end optimizations, to keep the tree as close to the
428 -- source code as possible, and also to avoid inconsistencies between
429 -- trees when using different optimization switches.
431 Optimization_Level := 0;
433 -- Enable some restrictions systematically to simplify the generated
434 -- code (and ease analysis). Note that restriction checks are also
435 -- disabled in Alfa mode, see Restrict.Check_Restriction, and user
436 -- specified Restrictions pragmas are ignored, see
437 -- Sem_Prag.Process_Restrictions_Or_Restriction_Warnings.
439 Restrict.Restrictions.Set (No_Initialize_Scalars) := True;
441 -- Suppress all language checks since they are handled implicitly by
442 -- the formal verification backend.
443 -- Turn off dynamic elaboration checks.
444 -- Turn off alignment checks.
445 -- Turn off validity checking.
447 Suppress_Options := (others => True);
448 Enable_Overflow_Checks := False;
449 Dynamic_Elaboration_Checks := False;
450 Reset_Validity_Check_Options;
452 -- Kill debug of generated code, since it messes up sloc values
454 Debug_Generated_Code := False;
456 -- Turn cross-referencing on in case it was disabled (e.g. by -gnatD)
457 -- as it is needed for computing effects of subprograms in the formal
458 -- verification backend.
462 -- Polling mode forced off, since it generates confusing junk
464 Polling_Required := False;
466 -- Set operating mode to Generate_Code, but full front-end expansion
467 -- is not desirable in Alfa mode, so a light expansion is performed
470 Operating_Mode := Generate_Code;
474 Debug_Flag_HH := True;
476 -- Disable Expressions_With_Actions nodes
478 -- The gnat2why backend does not deal with Expressions_With_Actions
479 -- in all places (in particular assertions). It is difficult to
480 -- determine in the frontend which cases are allowed, so we disable
481 -- Expressions_With_Actions entirely. Even in the cases where
482 -- gnat2why deals with Expressions_With_Actions, it is easier to
483 -- deal with the original constructs (quantified, conditional and
484 -- case expressions) instead of the rewritten ones.
486 Use_Expression_With_Actions := False;
488 -- Enable assertions and debug pragmas, since they give valuable
489 -- extra information for formal verification.
491 Assertions_Enabled := True;
492 Debug_Pragmas_Enabled := True;
494 -- Turn off style check options since we are not interested in any
495 -- front-end warnings when we are getting Alfa output.
497 Reset_Style_Check_Options;
499 -- Suppress compiler warnings, since what we are interested in here
500 -- is what formal verification can find out.
502 Warning_Mode := Suppress;
504 -- Suppress the generation of name tables for enumerations, which are
505 -- not needed for formal verification, and fall outside the Alfa
506 -- subset (use of pointers).
508 Global_Discard_Names := True;
510 -- Suppress the expansion of tagged types and dispatching calls,
511 -- which lead to the generation of non-Alfa code (use of pointers),
512 -- which is more complex to formally verify than the original source.
514 Tagged_Type_Expansion := False;
516 end Adjust_Global_Switches;
522 procedure Check_Bad_Body is
523 Sname : Unit_Name_Type;
524 Src_Ind : Source_File_Index;
525 Fname : File_Name_Type;
527 procedure Bad_Body_Error (Msg : String);
528 -- Issue message for bad body found
534 procedure Bad_Body_Error (Msg : String) is
536 Error_Msg_N (Msg, Main_Unit_Node);
537 Error_Msg_File_1 := Fname;
538 Error_Msg_N ("remove incorrect body in file{!", Main_Unit_Node);
541 -- Start of processing for Check_Bad_Body
544 -- Nothing to do if we are only checking syntax, because we don't know
545 -- enough to know if we require or forbid a body in this case.
547 if Operating_Mode = Check_Syntax then
551 -- Check for body not allowed
553 if (Main_Kind = N_Package_Declaration
554 and then not Body_Required (Main_Unit_Node))
555 or else (Main_Kind = N_Generic_Package_Declaration
556 and then not Body_Required (Main_Unit_Node))
557 or else Main_Kind = N_Package_Renaming_Declaration
558 or else Main_Kind = N_Subprogram_Renaming_Declaration
559 or else Nkind (Original_Node (Unit (Main_Unit_Node)))
560 in N_Generic_Instantiation
562 Sname := Unit_Name (Main_Unit);
564 -- If we do not already have a body name, then get the body name
565 -- (but how can we have a body name here???)
567 if not Is_Body_Name (Sname) then
568 Sname := Get_Body_Name (Sname);
571 Fname := Get_File_Name (Sname, Subunit => False);
572 Src_Ind := Load_Source_File (Fname);
574 -- Case where body is present and it is not a subunit. Exclude the
575 -- subunit case, because it has nothing to do with the package we are
576 -- compiling. It is illegal for a child unit and a subunit with the
577 -- same expanded name (RM 10.2(9)) to appear together in a partition,
578 -- but there is nothing to stop a compilation environment from having
579 -- both, and the test here simply allows that. If there is an attempt
580 -- to include both in a partition, this is diagnosed at bind time. In
581 -- Ada 83 mode this is not a warning case.
583 -- Note: if weird file names are being used, we can have a situation
584 -- where the file name that supposedly contains body in fact contains
585 -- a spec, or we can't tell what it contains. Skip the error message
588 -- Also ignore body that is nothing but pragma No_Body; (that's the
589 -- whole point of this pragma, to be used this way and to cause the
590 -- body file to be ignored in this context).
592 if Src_Ind /= No_Source_File
593 and then Get_Expected_Unit_Type (Fname) = Expect_Body
594 and then not Source_File_Is_Subunit (Src_Ind)
595 and then not Source_File_Is_No_Body (Src_Ind)
597 Errout.Finalize (Last_Call => False);
599 Error_Msg_Unit_1 := Sname;
601 -- Ada 83 case of a package body being ignored. This is not an
602 -- error as far as the Ada 83 RM is concerned, but it is almost
603 -- certainly not what is wanted so output a warning. Give this
604 -- message only if there were no errors, since otherwise it may
605 -- be incorrect (we may have misinterpreted a junk spec as not
606 -- needing a body when it really does).
608 if Main_Kind = N_Package_Declaration
609 and then Ada_Version = Ada_83
610 and then Operating_Mode = Generate_Code
611 and then Distribution_Stub_Mode /= Generate_Caller_Stub_Body
612 and then not Compilation_Errors
615 ("package $$ does not require a body?", Main_Unit_Node);
616 Error_Msg_File_1 := Fname;
617 Error_Msg_N ("body in file{? will be ignored", Main_Unit_Node);
619 -- Ada 95 cases of a body file present when no body is
620 -- permitted. This we consider to be an error.
623 -- For generic instantiations, we never allow a body
625 if Nkind (Original_Node (Unit (Main_Unit_Node)))
626 in N_Generic_Instantiation
629 ("generic instantiation for $$ does not allow a body");
631 -- A library unit that is a renaming never allows a body
633 elsif Main_Kind in N_Renaming_Declaration then
635 ("renaming declaration for $$ does not allow a body!");
637 -- Remaining cases are packages and generic packages. Here
638 -- we only do the test if there are no previous errors,
639 -- because if there are errors, they may lead us to
640 -- incorrectly believe that a package does not allow a body
641 -- when in fact it does.
643 elsif not Compilation_Errors then
644 if Main_Kind = N_Package_Declaration then
646 ("package $$ does not allow a body!");
648 elsif Main_Kind = N_Generic_Package_Declaration then
650 ("generic package $$ does not allow a body!");
659 -------------------------
660 -- Check_Library_Items --
661 -------------------------
663 -- Walk_Library_Items has plenty of assertions, so all we need to do is
664 -- call it, just for these assertions, not actually doing anything else.
666 procedure Check_Library_Items is
668 procedure Action (Item : Node_Id);
669 -- Action passed to Walk_Library_Items to do nothing
675 procedure Action (Item : Node_Id) is
680 procedure Walk is new Sem.Walk_Library_Items (Action);
682 -- Start of processing for Check_Library_Items
686 end Check_Library_Items;
692 procedure Check_Rep_Info is
694 if List_Representation_Info /= 0
695 or else List_Representation_Info_Mechanisms
700 ("cannot generate representation information, no code generated");
707 -- Start of processing for Gnat1drv
710 -- This inner block is set up to catch assertion errors and constraint
711 -- errors. Since the code for handling these errors can cause another
712 -- exception to be raised (namely Unrecoverable_Error), we need two
713 -- nested blocks, so that the outer one handles unrecoverable error.
716 -- Initialize all packages. For the most part, these initialization
717 -- calls can be made in any order. Exceptions are as follows:
719 -- Lib.Initialize need to be called before Scan_Compiler_Arguments,
720 -- because it initializes a table filled by Scan_Compiler_Arguments.
726 Scan_Compiler_Arguments;
727 Osint.Add_Default_Search_Dirs;
747 Sem_Type.Init_Interp_Tables;
749 -- Acquire target parameters from system.ads (source of package System)
754 S : Source_File_Index;
758 Name_Buffer (1 .. 10) := "system.ads";
761 S := Load_Source_File (N);
763 if S = No_Source_File then
765 ("fatal error, run-time library not installed correctly");
766 Write_Line ("cannot locate file system.ads");
767 raise Unrecoverable_Error;
769 -- Remember source index of system.ads (which was read successfully)
772 System_Source_File_Index := S;
775 Targparm.Get_Target_Parameters
776 (System_Text => Source_Text (S),
777 Source_First => Source_First (S),
778 Source_Last => Source_Last (S));
780 -- Acquire configuration pragma information from Targparm
782 Restrict.Restrictions := Targparm.Restrictions_On_Target;
785 Adjust_Global_Switches;
787 -- Output copyright notice if full list mode unless we have a list
788 -- file, in which case we defer this so that it is output in the file
790 if (Verbose_Mode or else (Full_List and then Full_List_File_Name = null))
791 and then not Debug_Flag_7
795 Write_Str (Gnat_Version_String);
797 Write_Str ("Copyright 1992-" & Current_Year
798 & ", Free Software Foundation, Inc.");
802 -- Check we do not have more than one source file, this happens only in
803 -- the case where the driver is called directly, it cannot happen when
804 -- gnat1 is invoked from gcc in the normal case.
806 if Osint.Number_Of_Files /= 1 then
809 Osint.Fail ("you must provide one source file");
811 elsif Usage_Requested then
815 Original_Operating_Mode := Operating_Mode;
818 -- Exit with errors if the main source could not be parsed. Also, when
819 -- -gnatd.H is present, the source file is not set.
821 if Sinput.Main_Source_File = No_Source_File then
823 -- Handle -gnatd.H debug mode
825 if Debug_Flag_Dot_HH then
827 -- For -gnatd.H, lock all the tables to keep the convention that
828 -- the backend needs to unlock the tables it wants to touch.
841 -- And all we need to do is to call the back end
843 Back_End.Call_Back_End (Back_End.Generate_Object);
846 Errout.Finalize (Last_Call => True);
847 Errout.Output_Messages;
848 Exit_Program (E_Errors);
851 Main_Unit_Node := Cunit (Main_Unit);
852 Main_Kind := Nkind (Unit (Main_Unit_Node));
855 -- In CodePeer mode we always delete old SCIL files before regenerating
856 -- new ones, in case of e.g. errors, and also to remove obsolete scilx
857 -- files generated by CodePeer itself.
859 if CodePeer_Mode then
860 Comperr.Delete_SCIL_Files;
863 -- Exit if compilation errors detected
865 Errout.Finalize (Last_Call => False);
867 if Compilation_Errors then
869 Sem_Ch13.Validate_Unchecked_Conversions;
870 Sem_Ch13.Validate_Address_Clauses;
871 Sem_Ch13.Validate_Independence;
872 Errout.Output_Messages;
875 -- Generate ALI file if specially requested
877 if Opt.Force_ALI_Tree_File then
878 Write_ALI (Object => False);
882 Errout.Finalize (Last_Call => True);
883 Exit_Program (E_Errors);
886 -- Set Generate_Code on main unit and its spec. We do this even if are
887 -- not generating code, since Lib-Writ uses this to determine which
888 -- units get written in the ali file.
890 Set_Generate_Code (Main_Unit);
892 -- If we have a corresponding spec, and it comes from source or it is
893 -- not a generated spec for a child subprogram body, then we need object
894 -- code for the spec unit as well.
896 if Nkind (Unit (Main_Unit_Node)) in N_Unit_Body
897 and then not Acts_As_Spec (Main_Unit_Node)
899 if Nkind (Unit (Main_Unit_Node)) = N_Subprogram_Body
900 and then not Comes_From_Source (Library_Unit (Main_Unit_Node))
905 (Get_Cunit_Unit_Number (Library_Unit (Main_Unit_Node)));
909 -- Case of no code required to be generated, exit indicating no error
911 if Original_Operating_Mode = Check_Syntax then
913 Errout.Finalize (Last_Call => True);
914 Errout.Output_Messages;
919 -- Use a goto instead of calling Exit_Program so that finalization
924 elsif Original_Operating_Mode = Check_Semantics then
925 Back_End_Mode := Declarations_Only;
927 -- All remaining cases are cases in which the user requested that code
928 -- be generated (i.e. no -gnatc or -gnats switch was used). Check if we
929 -- can in fact satisfy this request.
931 -- Cannot generate code if someone has turned off code generation for
932 -- any reason at all. We will try to figure out a reason below.
934 elsif Operating_Mode /= Generate_Code then
935 Back_End_Mode := Skip;
937 -- We can generate code for a subprogram body unless there were missing
938 -- subunits. Note that we always generate code for all generic units (a
939 -- change from some previous versions of GNAT).
941 elsif Main_Kind = N_Subprogram_Body and then not Subunits_Missing then
942 Back_End_Mode := Generate_Object;
944 -- We can generate code for a package body unless there are subunits
945 -- missing (note that we always generate code for generic units, which
946 -- is a change from some earlier versions of GNAT).
948 elsif Main_Kind = N_Package_Body and then not Subunits_Missing then
949 Back_End_Mode := Generate_Object;
951 -- We can generate code for a package declaration or a subprogram
952 -- declaration only if it does not required a body.
954 elsif Nkind_In (Main_Kind,
955 N_Package_Declaration,
956 N_Subprogram_Declaration)
958 (not Body_Required (Main_Unit_Node)
960 Distribution_Stub_Mode = Generate_Caller_Stub_Body)
962 Back_End_Mode := Generate_Object;
964 -- We can generate code for a generic package declaration of a generic
965 -- subprogram declaration only if does not require a body.
967 elsif Nkind_In (Main_Kind, N_Generic_Package_Declaration,
968 N_Generic_Subprogram_Declaration)
969 and then not Body_Required (Main_Unit_Node)
971 Back_End_Mode := Generate_Object;
973 -- Compilation units that are renamings do not require bodies, so we can
974 -- generate code for them.
976 elsif Nkind_In (Main_Kind, N_Package_Renaming_Declaration,
977 N_Subprogram_Renaming_Declaration)
979 Back_End_Mode := Generate_Object;
981 -- Compilation units that are generic renamings do not require bodies
982 -- so we can generate code for them.
984 elsif Main_Kind in N_Generic_Renaming_Declaration then
985 Back_End_Mode := Generate_Object;
987 -- It's not an error to generate SCIL for e.g. a spec which has a body
989 elsif CodePeer_Mode then
990 Back_End_Mode := Generate_Object;
992 -- In all other cases (specs which have bodies, generics, and bodies
993 -- where subunits are missing), we cannot generate code and we generate
994 -- a warning message. Note that generic instantiations are gone at this
995 -- stage since they have been replaced by their instances.
998 Back_End_Mode := Skip;
1001 -- At this stage Back_End_Mode is set to indicate if the backend should
1002 -- be called to generate code. If it is Skip, then code generation has
1003 -- been turned off, even though code was requested by the original
1004 -- command. This is not an error from the user point of view, but it is
1005 -- an error from the point of view of the gcc driver, so we must exit
1006 -- with an error status.
1008 -- We generate an informative message (from the gcc point of view, it
1009 -- is an error message, but from the users point of view this is not an
1010 -- error, just a consequence of compiling something that cannot
1013 if Back_End_Mode = Skip then
1015 Write_Str ("cannot generate code for ");
1016 Write_Str ("file ");
1017 Write_Name (Unit_File_Name (Main_Unit));
1019 if Subunits_Missing then
1020 Write_Str (" (missing subunits)");
1023 -- Force generation of ALI file, for backward compatibility
1025 Opt.Force_ALI_Tree_File := True;
1027 elsif Main_Kind = N_Subunit then
1028 Write_Str (" (subunit)");
1031 -- Force generation of ALI file, for backward compatibility
1033 Opt.Force_ALI_Tree_File := True;
1035 elsif Main_Kind = N_Subprogram_Declaration then
1036 Write_Str (" (subprogram spec)");
1039 -- Generic package body in GNAT implementation mode
1041 elsif Main_Kind = N_Package_Body and then GNAT_Mode then
1042 Write_Str (" (predefined generic)");
1045 -- Force generation of ALI file, for backward compatibility
1047 Opt.Force_ALI_Tree_File := True;
1049 -- Only other case is a package spec
1052 Write_Str (" (package spec)");
1056 Set_Standard_Output;
1058 Sem_Ch13.Validate_Unchecked_Conversions;
1059 Sem_Ch13.Validate_Address_Clauses;
1060 Sem_Ch13.Validate_Independence;
1061 Errout.Finalize (Last_Call => True);
1062 Errout.Output_Messages;
1066 -- Generate ALI file if specially requested, or for missing subunits,
1067 -- subunits or predefined generic.
1069 if Opt.Force_ALI_Tree_File then
1070 Write_ALI (Object => False);
1076 -- Exit program with error indication, to kill object file
1078 Exit_Program (E_No_Code);
1081 -- In -gnatc mode, we only do annotation if -gnatt or -gnatR is also set
1082 -- as indicated by Back_Annotate_Rep_Info being set to True.
1084 -- We don't call for annotations on a subunit, because to process those
1085 -- the back-end requires that the parent(s) be properly compiled.
1087 -- Annotation is suppressed for targets where front-end layout is
1088 -- enabled, because the front end determines representations.
1090 -- Annotation is also suppressed in the case of compiling for a VM,
1091 -- since representations are largely symbolic there.
1093 if Back_End_Mode = Declarations_Only
1094 and then (not (Back_Annotate_Rep_Info or Generate_SCIL)
1095 or else Main_Kind = N_Subunit
1096 or else Targparm.Frontend_Layout_On_Target
1097 or else Targparm.VM_Target /= No_VM)
1099 Sem_Ch13.Validate_Unchecked_Conversions;
1100 Sem_Ch13.Validate_Address_Clauses;
1101 Sem_Ch13.Validate_Independence;
1102 Errout.Finalize (Last_Call => True);
1103 Errout.Output_Messages;
1104 Write_ALI (Object => False);
1112 -- Ensure that we properly register a dependency on system.ads, since
1113 -- even if we do not semantically depend on this, Targparm has read
1114 -- system parameters from the system.ads file.
1116 Lib.Writ.Ensure_System_Dependency;
1118 -- Add dependencies, if any, on preprocessing data file and on
1119 -- preprocessing definition file(s).
1121 Prepcomp.Add_Dependencies;
1123 -- Back end needs to explicitly unlock tables it needs to touch
1136 -- ???Check_Library_Items under control of a debug flag, because it
1137 -- currently does not work if the -gnatn switch (back end inlining) is
1140 if Debug_Flag_Dot_WW then
1141 Check_Library_Items;
1144 -- Here we call the back end to generate the output code
1146 Generating_Code := True;
1147 Back_End.Call_Back_End (Back_End_Mode);
1149 -- Once the backend is complete, we unlock the names table. This call
1150 -- allows a few extra entries, needed for example for the file name for
1151 -- the library file output.
1155 -- Generate the call-graph output of dispatching calls
1157 Exp_CG.Generate_CG_Output;
1159 -- Validate unchecked conversions (using the values for size and
1160 -- alignment annotated by the backend where possible).
1162 Sem_Ch13.Validate_Unchecked_Conversions;
1164 -- Validate address clauses (again using alignment values annotated
1165 -- by the backend where possible).
1167 Sem_Ch13.Validate_Address_Clauses;
1169 -- Validate independence pragmas (again using values annotated by
1170 -- the back end for component layout etc.)
1172 Sem_Ch13.Validate_Independence;
1174 -- Now we complete output of errors, rep info and the tree info. These
1175 -- are delayed till now, since it is perfectly possible for gigi to
1176 -- generate errors, modify the tree (in particular by setting flags
1177 -- indicating that elaboration is required, and also to back annotate
1178 -- representation information for List_Rep_Info.
1180 Errout.Finalize (Last_Call => True);
1181 Errout.Output_Messages;
1185 -- Only write the library if the backend did not generate any error
1186 -- messages. Otherwise signal errors to the driver program so that
1187 -- there will be no attempt to generate an object file.
1189 if Compilation_Errors then
1191 Exit_Program (E_Errors);
1194 Write_ALI (Object => (Back_End_Mode = Generate_Object));
1196 if not Compilation_Errors then
1198 -- In case of ada backends, we need to make sure that the generated
1199 -- object file has a timestamp greater than the ALI file. We do this
1200 -- to make gnatmake happy when checking the ALI and obj timestamps,
1201 -- where it expects the object file being written after the ali file.
1203 -- Gnatmake's assumption is true for gcc platforms where the gcc
1204 -- wrapper needs to call the assembler after calling gnat1, but is
1205 -- not true for ada backends, where the object files are created
1206 -- directly by gnat1 (so are created before the ali file).
1208 Back_End.Gen_Or_Update_Object_File;
1211 -- Generate ASIS tree after writing the ALI file, since in ASIS mode,
1212 -- Write_ALI may in fact result in further tree decoration from the
1213 -- original tree file. Note that we dump the tree just before generating
1214 -- it, so that the dump will exactly reflect what is written out.
1219 -- Finalize name table and we are all done
1224 -- Handle fatal internal compiler errors
1226 when Rtsfind.RE_Not_Available =>
1227 Comperr.Compiler_Abort ("RE_Not_Available");
1229 when System.Assertions.Assert_Failure =>
1230 Comperr.Compiler_Abort ("Assert_Failure");
1232 when Constraint_Error =>
1233 Comperr.Compiler_Abort ("Constraint_Error");
1235 when Program_Error =>
1236 Comperr.Compiler_Abort ("Program_Error");
1238 when Storage_Error =>
1240 -- Assume this is a bug. If it is real, the message will in any case
1241 -- say Storage_Error, giving a strong hint!
1243 Comperr.Compiler_Abort ("Storage_Error");
1249 -- The outer exception handles an unrecoverable error
1252 when Unrecoverable_Error =>
1253 Errout.Finalize (Last_Call => True);
1254 Errout.Output_Messages;
1257 Write_Str ("compilation abandoned");
1260 Set_Standard_Output;
1263 Exit_Program (E_Errors);