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
121 if Debug_Flag_Dot_II and then Operating_Mode = Generate_Code then
122 Generate_SCIL := True;
125 -- Disable CodePeer_Mode in Check_Syntax, since we need front-end
128 if Operating_Mode = Check_Syntax then
129 CodePeer_Mode := False;
132 -- Set ASIS mode if -gnatt and -gnatc are set
134 if Operating_Mode = Check_Semantics and then Tree_Output then
137 -- Turn off inlining in ASIS mode, since ASIS cannot handle the extra
138 -- information in the trees caused by inlining being active.
140 -- More specifically, the tree seems to be malformed from the ASIS
141 -- point of view if -gnatc and -gnatn appear together???
143 Inline_Active := False;
145 -- Turn off SCIL generation and CodePeer mode in semantics mode,
146 -- since SCIL requires front-end expansion.
148 Generate_SCIL := False;
149 CodePeer_Mode := False;
152 -- SCIL mode needs to disable front-end inlining since the generated
153 -- trees (in particular order and consistency between specs compiled
154 -- as part of a main unit or as part of a with-clause) are causing
157 if Generate_SCIL then
158 Front_End_Inlining := False;
161 -- Tune settings for optimal SCIL generation in CodePeer mode
163 if CodePeer_Mode then
165 -- Turn off inlining, confuses CodePeer output and gains nothing
167 Front_End_Inlining := False;
168 Inline_Active := False;
170 -- Disable front-end optimizations, to keep the tree as close to the
171 -- source code as possible, and also to avoid inconsistencies between
172 -- trees when using different optimization switches.
174 Optimization_Level := 0;
176 -- Enable some restrictions systematically to simplify the generated
177 -- code (and ease analysis). Note that restriction checks are also
178 -- disabled in CodePeer mode, see Restrict.Check_Restriction, and
179 -- user specified Restrictions pragmas are ignored, see
180 -- Sem_Prag.Process_Restrictions_Or_Restriction_Warnings.
182 Restrict.Restrictions.Set (No_Initialize_Scalars) := True;
183 Restrict.Restrictions.Set (No_Task_Hierarchy) := True;
184 Restrict.Restrictions.Set (No_Abort_Statements) := True;
185 Restrict.Restrictions.Set (Max_Asynchronous_Select_Nesting) := True;
186 Restrict.Restrictions.Value (Max_Asynchronous_Select_Nesting) := 0;
188 -- Suppress overflow, division by zero and access checks since they
189 -- are handled implicitly by CodePeer.
191 -- Turn off dynamic elaboration checks: generates inconsistencies in
192 -- trees between specs compiled as part of a main unit or as part of
195 -- Turn off alignment checks: these cannot be proved statically by
196 -- CodePeer and generate false positives.
198 -- Enable all other language checks
201 (Access_Check => True,
202 Alignment_Check => True,
203 Division_Check => True,
204 Elaboration_Check => True,
205 Overflow_Check => True,
207 Enable_Overflow_Checks := False;
208 Dynamic_Elaboration_Checks := False;
210 -- Kill debug of generated code, since it messes up sloc values
212 Debug_Generated_Code := False;
214 -- Turn cross-referencing on in case it was disabled (e.g. by -gnatD)
215 -- Do we really need to spend time generating xref in CodePeer
216 -- mode??? Consider setting Xref_Active to False.
220 -- Polling mode forced off, since it generates confusing junk
222 Polling_Required := False;
224 -- Set operating mode to Generate_Code to benefit from full front-end
225 -- expansion (e.g. generics).
227 Operating_Mode := Generate_Code;
229 -- We need SCIL generation of course
231 Generate_SCIL := True;
233 -- Enable assertions and debug pragmas, since they give CodePeer
234 -- valuable extra information.
236 Assertions_Enabled := True;
237 Debug_Pragmas_Enabled := True;
239 -- Disable all simple value propagation. This is an optimization
240 -- which is valuable for code optimization, and also for generation
241 -- of compiler warnings, but these are being turned off by default,
242 -- and CodePeer generates better messages (referencing original
243 -- variables) this way.
245 Debug_Flag_MM := True;
247 -- Set normal RM validity checking, and checking of IN OUT parameters
248 -- (this might give CodePeer more useful checks to analyze, to be
249 -- confirmed???). All other validity checking is turned off, since
250 -- this can generate very complex trees that only confuse CodePeer
251 -- and do not bring enough useful info.
253 Reset_Validity_Check_Options;
254 Validity_Check_Default := True;
255 Validity_Check_In_Out_Params := True;
256 Validity_Check_In_Params := True;
258 -- Turn off style check options since we are not interested in any
259 -- front-end warnings when we are getting CodePeer output.
261 Reset_Style_Check_Options;
263 -- Always perform semantics and generate ali files in CodePeer mode,
264 -- so that a gnatmake -c -k will proceed further when possible.
266 Force_ALI_Tree_File := True;
267 Try_Semantics := True;
269 -- Enable Exception_Extra_Info for now, to avoid extra messages
270 -- on controlled operations.
271 -- ??? To be revised.
273 Exception_Extra_Info := True;
276 -- Set Configurable_Run_Time mode if system.ads flag set
278 if Targparm.Configurable_Run_Time_On_Target or Debug_Flag_YY then
279 Configurable_Run_Time_Mode := True;
282 -- Set -gnatR3m mode if debug flag A set
284 if Debug_Flag_AA then
285 Back_Annotate_Rep_Info := True;
286 List_Representation_Info := 1;
287 List_Representation_Info_Mechanisms := True;
290 -- Force Target_Strict_Alignment true if debug flag -gnatd.a is set
292 if Debug_Flag_Dot_A then
293 Ttypes.Target_Strict_Alignment := True;
296 -- Increase size of allocated entities if debug flag -gnatd.N is set
298 if Debug_Flag_Dot_NN then
299 Atree.Num_Extension_Nodes := Atree.Num_Extension_Nodes + 1;
302 -- Disable static allocation of dispatch tables if -gnatd.t or if layout
303 -- is enabled. The front end's layout phase currently treats types that
304 -- have discriminant-dependent arrays as not being static even when a
305 -- discriminant constraint on the type is static, and this leads to
306 -- problems with subtypes of type Ada.Tags.Dispatch_Table_Wrapper. ???
308 if Debug_Flag_Dot_T or else Frontend_Layout_On_Target then
309 Static_Dispatch_Tables := False;
312 -- Flip endian mode if -gnatd8 set
315 Ttypes.Bytes_Big_Endian := not Ttypes.Bytes_Big_Endian;
318 -- Deal with forcing OpenVMS switches True if debug flag M is set, but
319 -- record the setting of Targparm.Open_VMS_On_Target in True_VMS_Target
320 -- before doing this, so we know if we are in real OpenVMS or not!
322 Opt.True_VMS_Target := Targparm.OpenVMS_On_Target;
325 Targparm.OpenVMS_On_Target := True;
326 Hostparm.OpenVMS := True;
329 -- Activate front end layout if debug flag -gnatdF is set
331 if Debug_Flag_FF then
332 Targparm.Frontend_Layout_On_Target := True;
335 -- Set and check exception mechanism
337 if Targparm.ZCX_By_Default_On_Target then
338 Exception_Mechanism := Back_End_Exceptions;
341 -- Set proper status for overflow checks. We turn on overflow checks if
342 -- -gnatp was not specified, and either -gnato is set or the back-end
343 -- takes care of overflow checks. Otherwise we suppress overflow checks
344 -- by default (since front end checks are expensive).
346 if not Opt.Suppress_Checks
347 and then (Opt.Enable_Overflow_Checks
349 (Targparm.Backend_Divide_Checks_On_Target
351 Targparm.Backend_Overflow_Checks_On_Target))
353 Suppress_Options (Overflow_Check) := False;
355 Suppress_Options (Overflow_Check) := True;
358 -- Set default for atomic synchronization. As this synchronization
359 -- between atomic accesses can be expensive, and not typically needed
360 -- on some targets, an optional target parameter can turn the option
361 -- off. Note Atomic Synchronization is implemented as check.
363 Suppress_Options (Atomic_Synchronization) := not Atomic_Sync_Default;
365 -- Set switch indicating if we can use N_Expression_With_Actions
367 -- Debug flag -gnatd.X decisively sets usage on
369 if Debug_Flag_Dot_XX then
370 Use_Expression_With_Actions := True;
372 -- Debug flag -gnatd.Y decisively sets usage off
374 elsif Debug_Flag_Dot_YY then
375 Use_Expression_With_Actions := False;
377 -- Otherwise this feature is implemented, so we allow its use
380 Use_Expression_With_Actions := True;
383 -- Set switch indicating if back end can handle limited types, and
384 -- guarantee that no incorrect copies are made (e.g. in the context
385 -- of a conditional expression).
387 -- Debug flag -gnatd.L decisively sets usage on
389 if Debug_Flag_Dot_LL then
390 Back_End_Handles_Limited_Types := True;
392 -- If no debug flag, usage off for AAMP, VM, SCIL cases
395 or else VM_Target /= No_VM
396 or else Generate_SCIL
398 Back_End_Handles_Limited_Types := False;
400 -- Otherwise normal gcc back end, for now still turn flag off by
401 -- default, since there are unresolved problems in the front end.
404 Back_End_Handles_Limited_Types := False;
407 -- Set switches for formal verification mode
409 if Debug_Flag_Dot_FF then
413 -- Set strict standard interpretation of compiler permissions
415 if Debug_Flag_Dot_DD then
416 Strict_Alfa_Mode := True;
419 -- Turn off inlining, which would confuse formal verification output
422 Front_End_Inlining := False;
423 Inline_Active := False;
425 -- Disable front-end optimizations, to keep the tree as close to the
426 -- source code as possible, and also to avoid inconsistencies between
427 -- trees when using different optimization switches.
429 Optimization_Level := 0;
431 -- Enable some restrictions systematically to simplify the generated
432 -- code (and ease analysis). Note that restriction checks are also
433 -- disabled in Alfa mode, see Restrict.Check_Restriction, and user
434 -- specified Restrictions pragmas are ignored, see
435 -- Sem_Prag.Process_Restrictions_Or_Restriction_Warnings.
437 Restrict.Restrictions.Set (No_Initialize_Scalars) := True;
439 -- Suppress all language checks since they are handled implicitly by
440 -- the formal verification backend.
441 -- Turn off dynamic elaboration checks.
442 -- Turn off alignment checks.
443 -- Turn off validity checking.
445 Suppress_Options := (others => True);
446 Enable_Overflow_Checks := False;
447 Dynamic_Elaboration_Checks := False;
448 Reset_Validity_Check_Options;
450 -- Kill debug of generated code, since it messes up sloc values
452 Debug_Generated_Code := False;
454 -- Turn cross-referencing on in case it was disabled (e.g. by -gnatD)
455 -- as it is needed for computing effects of subprograms in the formal
456 -- verification backend.
460 -- Polling mode forced off, since it generates confusing junk
462 Polling_Required := False;
464 -- Set operating mode to Generate_Code, but full front-end expansion
465 -- is not desirable in Alfa mode, so a light expansion is performed
468 Operating_Mode := Generate_Code;
472 Debug_Flag_HH := True;
474 -- Disable Expressions_With_Actions nodes
476 -- The gnat2why backend does not deal with Expressions_With_Actions
477 -- in all places (in particular assertions). It is difficult to
478 -- determine in the frontend which cases are allowed, so we disable
479 -- Expressions_With_Actions entirely. Even in the cases where
480 -- gnat2why deals with Expressions_With_Actions, it is easier to
481 -- deal with the original constructs (quantified, conditional and
482 -- case expressions) instead of the rewritten ones.
484 Use_Expression_With_Actions := False;
486 -- Enable assertions and debug pragmas, since they give valuable
487 -- extra information for formal verification.
489 Assertions_Enabled := True;
490 Debug_Pragmas_Enabled := True;
492 -- Turn off style check options since we are not interested in any
493 -- front-end warnings when we are getting Alfa output.
495 Reset_Style_Check_Options;
497 -- Suppress compiler warnings, since what we are interested in here
498 -- is what formal verification can find out.
500 Warning_Mode := Suppress;
502 -- Suppress the generation of name tables for enumerations, which are
503 -- not needed for formal verification, and fall outside the Alfa
504 -- subset (use of pointers).
506 Global_Discard_Names := True;
508 -- Suppress the expansion of tagged types and dispatching calls,
509 -- which lead to the generation of non-Alfa code (use of pointers),
510 -- which is more complex to formally verify than the original source.
512 Tagged_Type_Expansion := False;
514 end Adjust_Global_Switches;
520 procedure Check_Bad_Body is
521 Sname : Unit_Name_Type;
522 Src_Ind : Source_File_Index;
523 Fname : File_Name_Type;
525 procedure Bad_Body_Error (Msg : String);
526 -- Issue message for bad body found
532 procedure Bad_Body_Error (Msg : String) is
534 Error_Msg_N (Msg, Main_Unit_Node);
535 Error_Msg_File_1 := Fname;
536 Error_Msg_N ("remove incorrect body in file{!", Main_Unit_Node);
539 -- Start of processing for Check_Bad_Body
542 -- Nothing to do if we are only checking syntax, because we don't know
543 -- enough to know if we require or forbid a body in this case.
545 if Operating_Mode = Check_Syntax then
549 -- Check for body not allowed
551 if (Main_Kind = N_Package_Declaration
552 and then not Body_Required (Main_Unit_Node))
553 or else (Main_Kind = N_Generic_Package_Declaration
554 and then not Body_Required (Main_Unit_Node))
555 or else Main_Kind = N_Package_Renaming_Declaration
556 or else Main_Kind = N_Subprogram_Renaming_Declaration
557 or else Nkind (Original_Node (Unit (Main_Unit_Node)))
558 in N_Generic_Instantiation
560 Sname := Unit_Name (Main_Unit);
562 -- If we do not already have a body name, then get the body name
563 -- (but how can we have a body name here???)
565 if not Is_Body_Name (Sname) then
566 Sname := Get_Body_Name (Sname);
569 Fname := Get_File_Name (Sname, Subunit => False);
570 Src_Ind := Load_Source_File (Fname);
572 -- Case where body is present and it is not a subunit. Exclude the
573 -- subunit case, because it has nothing to do with the package we are
574 -- compiling. It is illegal for a child unit and a subunit with the
575 -- same expanded name (RM 10.2(9)) to appear together in a partition,
576 -- but there is nothing to stop a compilation environment from having
577 -- both, and the test here simply allows that. If there is an attempt
578 -- to include both in a partition, this is diagnosed at bind time. In
579 -- Ada 83 mode this is not a warning case.
581 -- Note: if weird file names are being used, we can have a situation
582 -- where the file name that supposedly contains body in fact contains
583 -- a spec, or we can't tell what it contains. Skip the error message
586 -- Also ignore body that is nothing but pragma No_Body; (that's the
587 -- whole point of this pragma, to be used this way and to cause the
588 -- body file to be ignored in this context).
590 if Src_Ind /= No_Source_File
591 and then Get_Expected_Unit_Type (Fname) = Expect_Body
592 and then not Source_File_Is_Subunit (Src_Ind)
593 and then not Source_File_Is_No_Body (Src_Ind)
595 Errout.Finalize (Last_Call => False);
597 Error_Msg_Unit_1 := Sname;
599 -- Ada 83 case of a package body being ignored. This is not an
600 -- error as far as the Ada 83 RM is concerned, but it is almost
601 -- certainly not what is wanted so output a warning. Give this
602 -- message only if there were no errors, since otherwise it may
603 -- be incorrect (we may have misinterpreted a junk spec as not
604 -- needing a body when it really does).
606 if Main_Kind = N_Package_Declaration
607 and then Ada_Version = Ada_83
608 and then Operating_Mode = Generate_Code
609 and then Distribution_Stub_Mode /= Generate_Caller_Stub_Body
610 and then not Compilation_Errors
613 ("package $$ does not require a body?", Main_Unit_Node);
614 Error_Msg_File_1 := Fname;
615 Error_Msg_N ("body in file{? will be ignored", Main_Unit_Node);
617 -- Ada 95 cases of a body file present when no body is
618 -- permitted. This we consider to be an error.
621 -- For generic instantiations, we never allow a body
623 if Nkind (Original_Node (Unit (Main_Unit_Node)))
624 in N_Generic_Instantiation
627 ("generic instantiation for $$ does not allow a body");
629 -- A library unit that is a renaming never allows a body
631 elsif Main_Kind in N_Renaming_Declaration then
633 ("renaming declaration for $$ does not allow a body!");
635 -- Remaining cases are packages and generic packages. Here
636 -- we only do the test if there are no previous errors,
637 -- because if there are errors, they may lead us to
638 -- incorrectly believe that a package does not allow a body
639 -- when in fact it does.
641 elsif not Compilation_Errors then
642 if Main_Kind = N_Package_Declaration then
644 ("package $$ does not allow a body!");
646 elsif Main_Kind = N_Generic_Package_Declaration then
648 ("generic package $$ does not allow a body!");
657 -------------------------
658 -- Check_Library_Items --
659 -------------------------
661 -- Walk_Library_Items has plenty of assertions, so all we need to do is
662 -- call it, just for these assertions, not actually doing anything else.
664 procedure Check_Library_Items is
666 procedure Action (Item : Node_Id);
667 -- Action passed to Walk_Library_Items to do nothing
673 procedure Action (Item : Node_Id) is
678 procedure Walk is new Sem.Walk_Library_Items (Action);
680 -- Start of processing for Check_Library_Items
684 end Check_Library_Items;
690 procedure Check_Rep_Info is
692 if List_Representation_Info /= 0
693 or else List_Representation_Info_Mechanisms
698 ("cannot generate representation information, no code generated");
705 -- Start of processing for Gnat1drv
708 -- This inner block is set up to catch assertion errors and constraint
709 -- errors. Since the code for handling these errors can cause another
710 -- exception to be raised (namely Unrecoverable_Error), we need two
711 -- nested blocks, so that the outer one handles unrecoverable error.
714 -- Initialize all packages. For the most part, these initialization
715 -- calls can be made in any order. Exceptions are as follows:
717 -- Lib.Initialize need to be called before Scan_Compiler_Arguments,
718 -- because it initializes a table filled by Scan_Compiler_Arguments.
724 Scan_Compiler_Arguments;
725 Osint.Add_Default_Search_Dirs;
745 Sem_Type.Init_Interp_Tables;
747 -- Acquire target parameters from system.ads (source of package System)
752 S : Source_File_Index;
756 Name_Buffer (1 .. 10) := "system.ads";
759 S := Load_Source_File (N);
761 if S = No_Source_File then
763 ("fatal error, run-time library not installed correctly");
764 Write_Line ("cannot locate file system.ads");
765 raise Unrecoverable_Error;
767 -- Remember source index of system.ads (which was read successfully)
770 System_Source_File_Index := S;
773 Targparm.Get_Target_Parameters
774 (System_Text => Source_Text (S),
775 Source_First => Source_First (S),
776 Source_Last => Source_Last (S));
778 -- Acquire configuration pragma information from Targparm
780 Restrict.Restrictions := Targparm.Restrictions_On_Target;
783 Adjust_Global_Switches;
785 -- Output copyright notice if full list mode unless we have a list
786 -- file, in which case we defer this so that it is output in the file
788 if (Verbose_Mode or else (Full_List and then Full_List_File_Name = null))
789 and then not Debug_Flag_7
793 Write_Str (Gnat_Version_String);
795 Write_Str ("Copyright 1992-" & Current_Year
796 & ", Free Software Foundation, Inc.");
800 -- Check we do not have more than one source file, this happens only in
801 -- the case where the driver is called directly, it cannot happen when
802 -- gnat1 is invoked from gcc in the normal case.
804 if Osint.Number_Of_Files /= 1 then
807 Osint.Fail ("you must provide one source file");
809 elsif Usage_Requested then
813 Original_Operating_Mode := Operating_Mode;
816 -- Exit with errors if the main source could not be parsed. Also, when
817 -- -gnatd.H is present, the source file is not set.
819 if Sinput.Main_Source_File = No_Source_File then
821 -- Handle -gnatd.H debug mode
823 if Debug_Flag_Dot_HH then
825 -- For -gnatd.H, lock all the tables to keep the convention that
826 -- the backend needs to unlock the tables it wants to touch.
839 -- And all we need to do is to call the back end
841 Back_End.Call_Back_End (Back_End.Generate_Object);
844 Errout.Finalize (Last_Call => True);
845 Errout.Output_Messages;
846 Exit_Program (E_Errors);
849 Main_Unit_Node := Cunit (Main_Unit);
850 Main_Kind := Nkind (Unit (Main_Unit_Node));
853 -- In CodePeer mode we always delete old SCIL files before regenerating
854 -- new ones, in case of e.g. errors, and also to remove obsolete scilx
855 -- files generated by CodePeer itself.
857 if CodePeer_Mode then
858 Comperr.Delete_SCIL_Files;
861 -- Exit if compilation errors detected
863 Errout.Finalize (Last_Call => False);
865 if Compilation_Errors then
867 Sem_Ch13.Validate_Unchecked_Conversions;
868 Sem_Ch13.Validate_Address_Clauses;
869 Sem_Ch13.Validate_Independence;
870 Errout.Output_Messages;
873 -- Generate ALI file if specially requested
875 if Opt.Force_ALI_Tree_File then
876 Write_ALI (Object => False);
880 Errout.Finalize (Last_Call => True);
881 Exit_Program (E_Errors);
884 -- Set Generate_Code on main unit and its spec. We do this even if are
885 -- not generating code, since Lib-Writ uses this to determine which
886 -- units get written in the ali file.
888 Set_Generate_Code (Main_Unit);
890 -- If we have a corresponding spec, and it comes from source or it is
891 -- not a generated spec for a child subprogram body, then we need object
892 -- code for the spec unit as well.
894 if Nkind (Unit (Main_Unit_Node)) in N_Unit_Body
895 and then not Acts_As_Spec (Main_Unit_Node)
897 if Nkind (Unit (Main_Unit_Node)) = N_Subprogram_Body
898 and then not Comes_From_Source (Library_Unit (Main_Unit_Node))
903 (Get_Cunit_Unit_Number (Library_Unit (Main_Unit_Node)));
907 -- Case of no code required to be generated, exit indicating no error
909 if Original_Operating_Mode = Check_Syntax then
911 Errout.Finalize (Last_Call => True);
912 Errout.Output_Messages;
917 -- Use a goto instead of calling Exit_Program so that finalization
922 elsif Original_Operating_Mode = Check_Semantics then
923 Back_End_Mode := Declarations_Only;
925 -- All remaining cases are cases in which the user requested that code
926 -- be generated (i.e. no -gnatc or -gnats switch was used). Check if we
927 -- can in fact satisfy this request.
929 -- Cannot generate code if someone has turned off code generation for
930 -- any reason at all. We will try to figure out a reason below.
932 elsif Operating_Mode /= Generate_Code then
933 Back_End_Mode := Skip;
935 -- We can generate code for a subprogram body unless there were missing
936 -- subunits. Note that we always generate code for all generic units (a
937 -- change from some previous versions of GNAT).
939 elsif Main_Kind = N_Subprogram_Body and then not Subunits_Missing then
940 Back_End_Mode := Generate_Object;
942 -- We can generate code for a package body unless there are subunits
943 -- missing (note that we always generate code for generic units, which
944 -- is a change from some earlier versions of GNAT).
946 elsif Main_Kind = N_Package_Body and then not Subunits_Missing then
947 Back_End_Mode := Generate_Object;
949 -- We can generate code for a package declaration or a subprogram
950 -- declaration only if it does not required a body.
952 elsif Nkind_In (Main_Kind,
953 N_Package_Declaration,
954 N_Subprogram_Declaration)
956 (not Body_Required (Main_Unit_Node)
958 Distribution_Stub_Mode = Generate_Caller_Stub_Body)
960 Back_End_Mode := Generate_Object;
962 -- We can generate code for a generic package declaration of a generic
963 -- subprogram declaration only if does not require a body.
965 elsif Nkind_In (Main_Kind, N_Generic_Package_Declaration,
966 N_Generic_Subprogram_Declaration)
967 and then not Body_Required (Main_Unit_Node)
969 Back_End_Mode := Generate_Object;
971 -- Compilation units that are renamings do not require bodies, so we can
972 -- generate code for them.
974 elsif Nkind_In (Main_Kind, N_Package_Renaming_Declaration,
975 N_Subprogram_Renaming_Declaration)
977 Back_End_Mode := Generate_Object;
979 -- Compilation units that are generic renamings do not require bodies
980 -- so we can generate code for them.
982 elsif Main_Kind in N_Generic_Renaming_Declaration then
983 Back_End_Mode := Generate_Object;
985 -- It's not an error to generate SCIL for e.g. a spec which has a body
987 elsif CodePeer_Mode then
988 Back_End_Mode := Generate_Object;
990 -- In all other cases (specs which have bodies, generics, and bodies
991 -- where subunits are missing), we cannot generate code and we generate
992 -- a warning message. Note that generic instantiations are gone at this
993 -- stage since they have been replaced by their instances.
996 Back_End_Mode := Skip;
999 -- At this stage Back_End_Mode is set to indicate if the backend should
1000 -- be called to generate code. If it is Skip, then code generation has
1001 -- been turned off, even though code was requested by the original
1002 -- command. This is not an error from the user point of view, but it is
1003 -- an error from the point of view of the gcc driver, so we must exit
1004 -- with an error status.
1006 -- We generate an informative message (from the gcc point of view, it
1007 -- is an error message, but from the users point of view this is not an
1008 -- error, just a consequence of compiling something that cannot
1011 if Back_End_Mode = Skip then
1013 Write_Str ("cannot generate code for ");
1014 Write_Str ("file ");
1015 Write_Name (Unit_File_Name (Main_Unit));
1017 if Subunits_Missing then
1018 Write_Str (" (missing subunits)");
1021 -- Force generation of ALI file, for backward compatibility
1023 Opt.Force_ALI_Tree_File := True;
1025 elsif Main_Kind = N_Subunit then
1026 Write_Str (" (subunit)");
1029 -- Force generation of ALI file, for backward compatibility
1031 Opt.Force_ALI_Tree_File := True;
1033 elsif Main_Kind = N_Subprogram_Declaration then
1034 Write_Str (" (subprogram spec)");
1037 -- Generic package body in GNAT implementation mode
1039 elsif Main_Kind = N_Package_Body and then GNAT_Mode then
1040 Write_Str (" (predefined generic)");
1043 -- Force generation of ALI file, for backward compatibility
1045 Opt.Force_ALI_Tree_File := True;
1047 -- Only other case is a package spec
1050 Write_Str (" (package spec)");
1054 Set_Standard_Output;
1056 Sem_Ch13.Validate_Unchecked_Conversions;
1057 Sem_Ch13.Validate_Address_Clauses;
1058 Sem_Ch13.Validate_Independence;
1059 Errout.Finalize (Last_Call => True);
1060 Errout.Output_Messages;
1064 -- Generate ALI file if specially requested, or for missing subunits,
1065 -- subunits or predefined generic.
1067 if Opt.Force_ALI_Tree_File then
1068 Write_ALI (Object => False);
1074 -- Exit program with error indication, to kill object file
1076 Exit_Program (E_No_Code);
1079 -- In -gnatc mode, we only do annotation if -gnatt or -gnatR is also set
1080 -- as indicated by Back_Annotate_Rep_Info being set to True.
1082 -- We don't call for annotations on a subunit, because to process those
1083 -- the back-end requires that the parent(s) be properly compiled.
1085 -- Annotation is suppressed for targets where front-end layout is
1086 -- enabled, because the front end determines representations.
1088 -- Annotation is also suppressed in the case of compiling for a VM,
1089 -- since representations are largely symbolic there.
1091 if Back_End_Mode = Declarations_Only
1092 and then (not (Back_Annotate_Rep_Info or Generate_SCIL)
1093 or else Main_Kind = N_Subunit
1094 or else Targparm.Frontend_Layout_On_Target
1095 or else Targparm.VM_Target /= No_VM)
1097 Sem_Ch13.Validate_Unchecked_Conversions;
1098 Sem_Ch13.Validate_Address_Clauses;
1099 Sem_Ch13.Validate_Independence;
1100 Errout.Finalize (Last_Call => True);
1101 Errout.Output_Messages;
1102 Write_ALI (Object => False);
1110 -- Ensure that we properly register a dependency on system.ads, since
1111 -- even if we do not semantically depend on this, Targparm has read
1112 -- system parameters from the system.ads file.
1114 Lib.Writ.Ensure_System_Dependency;
1116 -- Add dependencies, if any, on preprocessing data file and on
1117 -- preprocessing definition file(s).
1119 Prepcomp.Add_Dependencies;
1121 -- Back end needs to explicitly unlock tables it needs to touch
1134 -- ???Check_Library_Items under control of a debug flag, because it
1135 -- currently does not work if the -gnatn switch (back end inlining) is
1138 if Debug_Flag_Dot_WW then
1139 Check_Library_Items;
1142 -- Here we call the back end to generate the output code
1144 Generating_Code := True;
1145 Back_End.Call_Back_End (Back_End_Mode);
1147 -- Once the backend is complete, we unlock the names table. This call
1148 -- allows a few extra entries, needed for example for the file name for
1149 -- the library file output.
1153 -- Generate the call-graph output of dispatching calls
1155 Exp_CG.Generate_CG_Output;
1157 -- Validate unchecked conversions (using the values for size and
1158 -- alignment annotated by the backend where possible).
1160 Sem_Ch13.Validate_Unchecked_Conversions;
1162 -- Validate address clauses (again using alignment values annotated
1163 -- by the backend where possible).
1165 Sem_Ch13.Validate_Address_Clauses;
1167 -- Validate independence pragmas (again using values annotated by
1168 -- the back end for component layout etc.)
1170 Sem_Ch13.Validate_Independence;
1172 -- Now we complete output of errors, rep info and the tree info. These
1173 -- are delayed till now, since it is perfectly possible for gigi to
1174 -- generate errors, modify the tree (in particular by setting flags
1175 -- indicating that elaboration is required, and also to back annotate
1176 -- representation information for List_Rep_Info.
1178 Errout.Finalize (Last_Call => True);
1179 Errout.Output_Messages;
1183 -- Only write the library if the backend did not generate any error
1184 -- messages. Otherwise signal errors to the driver program so that
1185 -- there will be no attempt to generate an object file.
1187 if Compilation_Errors then
1189 Exit_Program (E_Errors);
1192 Write_ALI (Object => (Back_End_Mode = Generate_Object));
1194 if not Compilation_Errors then
1196 -- In case of ada backends, we need to make sure that the generated
1197 -- object file has a timestamp greater than the ALI file. We do this
1198 -- to make gnatmake happy when checking the ALI and obj timestamps,
1199 -- where it expects the object file being written after the ali file.
1201 -- Gnatmake's assumption is true for gcc platforms where the gcc
1202 -- wrapper needs to call the assembler after calling gnat1, but is
1203 -- not true for ada backends, where the object files are created
1204 -- directly by gnat1 (so are created before the ali file).
1206 Back_End.Gen_Or_Update_Object_File;
1209 -- Generate ASIS tree after writing the ALI file, since in ASIS mode,
1210 -- Write_ALI may in fact result in further tree decoration from the
1211 -- original tree file. Note that we dump the tree just before generating
1212 -- it, so that the dump will exactly reflect what is written out.
1217 -- Finalize name table and we are all done
1222 -- Handle fatal internal compiler errors
1224 when Rtsfind.RE_Not_Available =>
1225 Comperr.Compiler_Abort ("RE_Not_Available");
1227 when System.Assertions.Assert_Failure =>
1228 Comperr.Compiler_Abort ("Assert_Failure");
1230 when Constraint_Error =>
1231 Comperr.Compiler_Abort ("Constraint_Error");
1233 when Program_Error =>
1234 Comperr.Compiler_Abort ("Program_Error");
1236 when Storage_Error =>
1238 -- Assume this is a bug. If it is real, the message will in any case
1239 -- say Storage_Error, giving a strong hint!
1241 Comperr.Compiler_Abort ("Storage_Error");
1247 -- The outer exception handles an unrecoverable error
1250 when Unrecoverable_Error =>
1251 Errout.Finalize (Last_Call => True);
1252 Errout.Output_Messages;
1255 Write_Str ("compilation abandoned");
1258 Set_Standard_Output;
1261 Exit_Program (E_Errors);