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;
270 -- Set Configurable_Run_Time mode if system.ads flag set
272 if Targparm.Configurable_Run_Time_On_Target or Debug_Flag_YY then
273 Configurable_Run_Time_Mode := True;
276 -- Set -gnatR3m mode if debug flag A set
278 if Debug_Flag_AA then
279 Back_Annotate_Rep_Info := True;
280 List_Representation_Info := 1;
281 List_Representation_Info_Mechanisms := True;
284 -- Force Target_Strict_Alignment true if debug flag -gnatd.a is set
286 if Debug_Flag_Dot_A then
287 Ttypes.Target_Strict_Alignment := True;
290 -- Increase size of allocated entities if debug flag -gnatd.N is set
292 if Debug_Flag_Dot_NN then
293 Atree.Num_Extension_Nodes := Atree.Num_Extension_Nodes + 1;
296 -- Disable static allocation of dispatch tables if -gnatd.t or if layout
297 -- is enabled. The front end's layout phase currently treats types that
298 -- have discriminant-dependent arrays as not being static even when a
299 -- discriminant constraint on the type is static, and this leads to
300 -- problems with subtypes of type Ada.Tags.Dispatch_Table_Wrapper. ???
302 if Debug_Flag_Dot_T or else Frontend_Layout_On_Target then
303 Static_Dispatch_Tables := False;
306 -- Flip endian mode if -gnatd8 set
309 Ttypes.Bytes_Big_Endian := not Ttypes.Bytes_Big_Endian;
312 -- Deal with forcing OpenVMS switches True if debug flag M is set, but
313 -- record the setting of Targparm.Open_VMS_On_Target in True_VMS_Target
314 -- before doing this, so we know if we are in real OpenVMS or not!
316 Opt.True_VMS_Target := Targparm.OpenVMS_On_Target;
319 Targparm.OpenVMS_On_Target := True;
320 Hostparm.OpenVMS := True;
323 -- Activate front end layout if debug flag -gnatdF is set
325 if Debug_Flag_FF then
326 Targparm.Frontend_Layout_On_Target := True;
329 -- Set and check exception mechanism
331 if Targparm.ZCX_By_Default_On_Target then
332 Exception_Mechanism := Back_End_Exceptions;
335 -- Set proper status for overflow checks. We turn on overflow checks if
336 -- -gnatp was not specified, and either -gnato is set or the back-end
337 -- takes care of overflow checks. Otherwise we suppress overflow checks
338 -- by default (since front end checks are expensive).
340 if not Opt.Suppress_Checks
341 and then (Opt.Enable_Overflow_Checks
343 (Targparm.Backend_Divide_Checks_On_Target
345 Targparm.Backend_Overflow_Checks_On_Target))
347 Suppress_Options (Overflow_Check) := False;
349 Suppress_Options (Overflow_Check) := True;
352 -- Set default for atomic synchronization. As this synchronization
353 -- between atomic accesses can be expensive, and not typically needed
354 -- on some targets, an optional target parameter can turn the option
355 -- off. Note Atomic Synchronization is implemented as check.
357 Suppress_Options (Atomic_Synchronization) := not Atomic_Sync_Default;
359 -- Set switch indicating if we can use N_Expression_With_Actions
361 -- Debug flag -gnatd.X decisively sets usage on
363 if Debug_Flag_Dot_XX then
364 Use_Expression_With_Actions := True;
366 -- Debug flag -gnatd.Y decisively sets usage off
368 elsif Debug_Flag_Dot_YY then
369 Use_Expression_With_Actions := False;
371 -- Otherwise this feature is implemented, so we allow its use
374 Use_Expression_With_Actions := True;
377 -- Set switch indicating if back end can handle limited types, and
378 -- guarantee that no incorrect copies are made (e.g. in the context
379 -- of a conditional expression).
381 -- Debug flag -gnatd.L decisively sets usage on
383 if Debug_Flag_Dot_LL then
384 Back_End_Handles_Limited_Types := True;
386 -- If no debug flag, usage off for AAMP, VM, SCIL cases
389 or else VM_Target /= No_VM
390 or else Generate_SCIL
392 Back_End_Handles_Limited_Types := False;
394 -- Otherwise normal gcc back end, for now still turn flag off by
395 -- default, since there are unresolved problems in the front end.
398 Back_End_Handles_Limited_Types := False;
401 -- Set switches for formal verification mode
403 if Debug_Flag_Dot_FF then
407 -- Set strict standard interpretation of compiler permissions
409 if Debug_Flag_Dot_DD then
410 Strict_Alfa_Mode := True;
413 -- Turn off inlining, which would confuse formal verification output
416 Front_End_Inlining := False;
417 Inline_Active := False;
419 -- Disable front-end optimizations, to keep the tree as close to the
420 -- source code as possible, and also to avoid inconsistencies between
421 -- trees when using different optimization switches.
423 Optimization_Level := 0;
425 -- Enable some restrictions systematically to simplify the generated
426 -- code (and ease analysis). Note that restriction checks are also
427 -- disabled in Alfa mode, see Restrict.Check_Restriction, and user
428 -- specified Restrictions pragmas are ignored, see
429 -- Sem_Prag.Process_Restrictions_Or_Restriction_Warnings.
431 Restrict.Restrictions.Set (No_Initialize_Scalars) := True;
433 -- Suppress all language checks since they are handled implicitly by
434 -- the formal verification backend.
435 -- Turn off dynamic elaboration checks.
436 -- Turn off alignment checks.
437 -- Turn off validity checking.
439 Suppress_Options := (others => True);
440 Enable_Overflow_Checks := False;
441 Dynamic_Elaboration_Checks := False;
442 Reset_Validity_Check_Options;
444 -- Kill debug of generated code, since it messes up sloc values
446 Debug_Generated_Code := False;
448 -- Turn cross-referencing on in case it was disabled (e.g. by -gnatD)
449 -- as it is needed for computing effects of subprograms in the formal
450 -- verification backend.
454 -- Polling mode forced off, since it generates confusing junk
456 Polling_Required := False;
458 -- Set operating mode to Generate_Code, but full front-end expansion
459 -- is not desirable in Alfa mode, so a light expansion is performed
462 Operating_Mode := Generate_Code;
466 Debug_Flag_HH := True;
468 -- Disable Expressions_With_Actions nodes
470 -- The gnat2why backend does not deal with Expressions_With_Actions
471 -- in all places (in particular assertions). It is difficult to
472 -- determine in the frontend which cases are allowed, so we disable
473 -- Expressions_With_Actions entirely. Even in the cases where
474 -- gnat2why deals with Expressions_With_Actions, it is easier to
475 -- deal with the original constructs (quantified, conditional and
476 -- case expressions) instead of the rewritten ones.
478 Use_Expression_With_Actions := False;
480 -- Enable assertions and debug pragmas, since they give valuable
481 -- extra information for formal verification.
483 Assertions_Enabled := True;
484 Debug_Pragmas_Enabled := True;
486 -- Turn off style check options since we are not interested in any
487 -- front-end warnings when we are getting Alfa output.
489 Reset_Style_Check_Options;
491 -- Suppress compiler warnings, since what we are interested in here
492 -- is what formal verification can find out.
494 Warning_Mode := Suppress;
496 -- Suppress the generation of name tables for enumerations, which are
497 -- not needed for formal verification, and fall outside the Alfa
498 -- subset (use of pointers).
500 Global_Discard_Names := True;
502 -- Suppress the expansion of tagged types and dispatching calls,
503 -- which lead to the generation of non-Alfa code (use of pointers),
504 -- which is more complex to formally verify than the original source.
506 Tagged_Type_Expansion := False;
508 end Adjust_Global_Switches;
514 procedure Check_Bad_Body is
515 Sname : Unit_Name_Type;
516 Src_Ind : Source_File_Index;
517 Fname : File_Name_Type;
519 procedure Bad_Body_Error (Msg : String);
520 -- Issue message for bad body found
526 procedure Bad_Body_Error (Msg : String) is
528 Error_Msg_N (Msg, Main_Unit_Node);
529 Error_Msg_File_1 := Fname;
530 Error_Msg_N ("remove incorrect body in file{!", Main_Unit_Node);
533 -- Start of processing for Check_Bad_Body
536 -- Nothing to do if we are only checking syntax, because we don't know
537 -- enough to know if we require or forbid a body in this case.
539 if Operating_Mode = Check_Syntax then
543 -- Check for body not allowed
545 if (Main_Kind = N_Package_Declaration
546 and then not Body_Required (Main_Unit_Node))
547 or else (Main_Kind = N_Generic_Package_Declaration
548 and then not Body_Required (Main_Unit_Node))
549 or else Main_Kind = N_Package_Renaming_Declaration
550 or else Main_Kind = N_Subprogram_Renaming_Declaration
551 or else Nkind (Original_Node (Unit (Main_Unit_Node)))
552 in N_Generic_Instantiation
554 Sname := Unit_Name (Main_Unit);
556 -- If we do not already have a body name, then get the body name
557 -- (but how can we have a body name here???)
559 if not Is_Body_Name (Sname) then
560 Sname := Get_Body_Name (Sname);
563 Fname := Get_File_Name (Sname, Subunit => False);
564 Src_Ind := Load_Source_File (Fname);
566 -- Case where body is present and it is not a subunit. Exclude the
567 -- subunit case, because it has nothing to do with the package we are
568 -- compiling. It is illegal for a child unit and a subunit with the
569 -- same expanded name (RM 10.2(9)) to appear together in a partition,
570 -- but there is nothing to stop a compilation environment from having
571 -- both, and the test here simply allows that. If there is an attempt
572 -- to include both in a partition, this is diagnosed at bind time. In
573 -- Ada 83 mode this is not a warning case.
575 -- Note: if weird file names are being used, we can have a situation
576 -- where the file name that supposedly contains body in fact contains
577 -- a spec, or we can't tell what it contains. Skip the error message
580 -- Also ignore body that is nothing but pragma No_Body; (that's the
581 -- whole point of this pragma, to be used this way and to cause the
582 -- body file to be ignored in this context).
584 if Src_Ind /= No_Source_File
585 and then Get_Expected_Unit_Type (Fname) = Expect_Body
586 and then not Source_File_Is_Subunit (Src_Ind)
587 and then not Source_File_Is_No_Body (Src_Ind)
589 Errout.Finalize (Last_Call => False);
591 Error_Msg_Unit_1 := Sname;
593 -- Ada 83 case of a package body being ignored. This is not an
594 -- error as far as the Ada 83 RM is concerned, but it is almost
595 -- certainly not what is wanted so output a warning. Give this
596 -- message only if there were no errors, since otherwise it may
597 -- be incorrect (we may have misinterpreted a junk spec as not
598 -- needing a body when it really does).
600 if Main_Kind = N_Package_Declaration
601 and then Ada_Version = Ada_83
602 and then Operating_Mode = Generate_Code
603 and then Distribution_Stub_Mode /= Generate_Caller_Stub_Body
604 and then not Compilation_Errors
607 ("package $$ does not require a body?", Main_Unit_Node);
608 Error_Msg_File_1 := Fname;
609 Error_Msg_N ("body in file{? will be ignored", Main_Unit_Node);
611 -- Ada 95 cases of a body file present when no body is
612 -- permitted. This we consider to be an error.
615 -- For generic instantiations, we never allow a body
617 if Nkind (Original_Node (Unit (Main_Unit_Node)))
618 in N_Generic_Instantiation
621 ("generic instantiation for $$ does not allow a body");
623 -- A library unit that is a renaming never allows a body
625 elsif Main_Kind in N_Renaming_Declaration then
627 ("renaming declaration for $$ does not allow a body!");
629 -- Remaining cases are packages and generic packages. Here
630 -- we only do the test if there are no previous errors,
631 -- because if there are errors, they may lead us to
632 -- incorrectly believe that a package does not allow a body
633 -- when in fact it does.
635 elsif not Compilation_Errors then
636 if Main_Kind = N_Package_Declaration then
638 ("package $$ does not allow a body!");
640 elsif Main_Kind = N_Generic_Package_Declaration then
642 ("generic package $$ does not allow a body!");
651 -------------------------
652 -- Check_Library_Items --
653 -------------------------
655 -- Walk_Library_Items has plenty of assertions, so all we need to do is
656 -- call it, just for these assertions, not actually doing anything else.
658 procedure Check_Library_Items is
660 procedure Action (Item : Node_Id);
661 -- Action passed to Walk_Library_Items to do nothing
667 procedure Action (Item : Node_Id) is
672 procedure Walk is new Sem.Walk_Library_Items (Action);
674 -- Start of processing for Check_Library_Items
678 end Check_Library_Items;
684 procedure Check_Rep_Info is
686 if List_Representation_Info /= 0
687 or else List_Representation_Info_Mechanisms
692 ("cannot generate representation information, no code generated");
699 -- Start of processing for Gnat1drv
702 -- This inner block is set up to catch assertion errors and constraint
703 -- errors. Since the code for handling these errors can cause another
704 -- exception to be raised (namely Unrecoverable_Error), we need two
705 -- nested blocks, so that the outer one handles unrecoverable error.
708 -- Initialize all packages. For the most part, these initialization
709 -- calls can be made in any order. Exceptions are as follows:
711 -- Lib.Initialize need to be called before Scan_Compiler_Arguments,
712 -- because it initializes a table filled by Scan_Compiler_Arguments.
718 Scan_Compiler_Arguments;
719 Osint.Add_Default_Search_Dirs;
739 Sem_Type.Init_Interp_Tables;
741 -- Acquire target parameters from system.ads (source of package System)
746 S : Source_File_Index;
750 Name_Buffer (1 .. 10) := "system.ads";
753 S := Load_Source_File (N);
755 if S = No_Source_File then
757 ("fatal error, run-time library not installed correctly");
758 Write_Line ("cannot locate file system.ads");
759 raise Unrecoverable_Error;
761 -- Remember source index of system.ads (which was read successfully)
764 System_Source_File_Index := S;
767 Targparm.Get_Target_Parameters
768 (System_Text => Source_Text (S),
769 Source_First => Source_First (S),
770 Source_Last => Source_Last (S));
772 -- Acquire configuration pragma information from Targparm
774 Restrict.Restrictions := Targparm.Restrictions_On_Target;
777 Adjust_Global_Switches;
779 -- Output copyright notice if full list mode unless we have a list
780 -- file, in which case we defer this so that it is output in the file
782 if (Verbose_Mode or else (Full_List and then Full_List_File_Name = null))
783 and then not Debug_Flag_7
787 Write_Str (Gnat_Version_String);
789 Write_Str ("Copyright 1992-" & Current_Year
790 & ", Free Software Foundation, Inc.");
794 -- Check we do not have more than one source file, this happens only in
795 -- the case where the driver is called directly, it cannot happen when
796 -- gnat1 is invoked from gcc in the normal case.
798 if Osint.Number_Of_Files /= 1 then
801 Osint.Fail ("you must provide one source file");
803 elsif Usage_Requested then
807 Original_Operating_Mode := Operating_Mode;
810 -- Exit with errors if the main source could not be parsed. Also, when
811 -- -gnatd.H is present, the source file is not set.
813 if Sinput.Main_Source_File = No_Source_File then
815 -- Handle -gnatd.H debug mode
817 if Debug_Flag_Dot_HH then
819 -- For -gnatd.H, lock all the tables to keep the convention that
820 -- the backend needs to unlock the tables it wants to touch.
833 -- And all we need to do is to call the back end
835 Back_End.Call_Back_End (Back_End.Generate_Object);
838 Errout.Finalize (Last_Call => True);
839 Errout.Output_Messages;
840 Exit_Program (E_Errors);
843 Main_Unit_Node := Cunit (Main_Unit);
844 Main_Kind := Nkind (Unit (Main_Unit_Node));
847 -- In CodePeer mode we always delete old SCIL files before regenerating
848 -- new ones, in case of e.g. errors, and also to remove obsolete scilx
849 -- files generated by CodePeer itself.
851 if CodePeer_Mode then
852 Comperr.Delete_SCIL_Files;
855 -- Exit if compilation errors detected
857 Errout.Finalize (Last_Call => False);
859 if Compilation_Errors then
861 Sem_Ch13.Validate_Unchecked_Conversions;
862 Sem_Ch13.Validate_Address_Clauses;
863 Sem_Ch13.Validate_Independence;
864 Errout.Output_Messages;
867 -- Generate ALI file if specially requested
869 if Opt.Force_ALI_Tree_File then
870 Write_ALI (Object => False);
874 Errout.Finalize (Last_Call => True);
875 Exit_Program (E_Errors);
878 -- Set Generate_Code on main unit and its spec. We do this even if are
879 -- not generating code, since Lib-Writ uses this to determine which
880 -- units get written in the ali file.
882 Set_Generate_Code (Main_Unit);
884 -- If we have a corresponding spec, and it comes from source or it is
885 -- not a generated spec for a child subprogram body, then we need object
886 -- code for the spec unit as well.
888 if Nkind (Unit (Main_Unit_Node)) in N_Unit_Body
889 and then not Acts_As_Spec (Main_Unit_Node)
891 if Nkind (Unit (Main_Unit_Node)) = N_Subprogram_Body
892 and then not Comes_From_Source (Library_Unit (Main_Unit_Node))
897 (Get_Cunit_Unit_Number (Library_Unit (Main_Unit_Node)));
901 -- Case of no code required to be generated, exit indicating no error
903 if Original_Operating_Mode = Check_Syntax then
905 Errout.Finalize (Last_Call => True);
906 Errout.Output_Messages;
911 -- Use a goto instead of calling Exit_Program so that finalization
916 elsif Original_Operating_Mode = Check_Semantics then
917 Back_End_Mode := Declarations_Only;
919 -- All remaining cases are cases in which the user requested that code
920 -- be generated (i.e. no -gnatc or -gnats switch was used). Check if we
921 -- can in fact satisfy this request.
923 -- Cannot generate code if someone has turned off code generation for
924 -- any reason at all. We will try to figure out a reason below.
926 elsif Operating_Mode /= Generate_Code then
927 Back_End_Mode := Skip;
929 -- We can generate code for a subprogram body unless there were missing
930 -- subunits. Note that we always generate code for all generic units (a
931 -- change from some previous versions of GNAT).
933 elsif Main_Kind = N_Subprogram_Body and then not Subunits_Missing then
934 Back_End_Mode := Generate_Object;
936 -- We can generate code for a package body unless there are subunits
937 -- missing (note that we always generate code for generic units, which
938 -- is a change from some earlier versions of GNAT).
940 elsif Main_Kind = N_Package_Body and then not Subunits_Missing then
941 Back_End_Mode := Generate_Object;
943 -- We can generate code for a package declaration or a subprogram
944 -- declaration only if it does not required a body.
946 elsif Nkind_In (Main_Kind,
947 N_Package_Declaration,
948 N_Subprogram_Declaration)
950 (not Body_Required (Main_Unit_Node)
952 Distribution_Stub_Mode = Generate_Caller_Stub_Body)
954 Back_End_Mode := Generate_Object;
956 -- We can generate code for a generic package declaration of a generic
957 -- subprogram declaration only if does not require a body.
959 elsif Nkind_In (Main_Kind, N_Generic_Package_Declaration,
960 N_Generic_Subprogram_Declaration)
961 and then not Body_Required (Main_Unit_Node)
963 Back_End_Mode := Generate_Object;
965 -- Compilation units that are renamings do not require bodies, so we can
966 -- generate code for them.
968 elsif Nkind_In (Main_Kind, N_Package_Renaming_Declaration,
969 N_Subprogram_Renaming_Declaration)
971 Back_End_Mode := Generate_Object;
973 -- Compilation units that are generic renamings do not require bodies
974 -- so we can generate code for them.
976 elsif Main_Kind in N_Generic_Renaming_Declaration then
977 Back_End_Mode := Generate_Object;
979 -- It's not an error to generate SCIL for e.g. a spec which has a body
981 elsif CodePeer_Mode then
982 Back_End_Mode := Generate_Object;
984 -- In all other cases (specs which have bodies, generics, and bodies
985 -- where subunits are missing), we cannot generate code and we generate
986 -- a warning message. Note that generic instantiations are gone at this
987 -- stage since they have been replaced by their instances.
990 Back_End_Mode := Skip;
993 -- At this stage Back_End_Mode is set to indicate if the backend should
994 -- be called to generate code. If it is Skip, then code generation has
995 -- been turned off, even though code was requested by the original
996 -- command. This is not an error from the user point of view, but it is
997 -- an error from the point of view of the gcc driver, so we must exit
998 -- with an error status.
1000 -- We generate an informative message (from the gcc point of view, it
1001 -- is an error message, but from the users point of view this is not an
1002 -- error, just a consequence of compiling something that cannot
1005 if Back_End_Mode = Skip then
1007 Write_Str ("cannot generate code for ");
1008 Write_Str ("file ");
1009 Write_Name (Unit_File_Name (Main_Unit));
1011 if Subunits_Missing then
1012 Write_Str (" (missing subunits)");
1015 -- Force generation of ALI file, for backward compatibility
1017 Opt.Force_ALI_Tree_File := True;
1019 elsif Main_Kind = N_Subunit then
1020 Write_Str (" (subunit)");
1023 -- Force generation of ALI file, for backward compatibility
1025 Opt.Force_ALI_Tree_File := True;
1027 elsif Main_Kind = N_Subprogram_Declaration then
1028 Write_Str (" (subprogram spec)");
1031 -- Generic package body in GNAT implementation mode
1033 elsif Main_Kind = N_Package_Body and then GNAT_Mode then
1034 Write_Str (" (predefined generic)");
1037 -- Force generation of ALI file, for backward compatibility
1039 Opt.Force_ALI_Tree_File := True;
1041 -- Only other case is a package spec
1044 Write_Str (" (package spec)");
1048 Set_Standard_Output;
1050 Sem_Ch13.Validate_Unchecked_Conversions;
1051 Sem_Ch13.Validate_Address_Clauses;
1052 Sem_Ch13.Validate_Independence;
1053 Errout.Finalize (Last_Call => True);
1054 Errout.Output_Messages;
1058 -- Generate ALI file if specially requested, or for missing subunits,
1059 -- subunits or predefined generic.
1061 if Opt.Force_ALI_Tree_File then
1062 Write_ALI (Object => False);
1068 -- Exit program with error indication, to kill object file
1070 Exit_Program (E_No_Code);
1073 -- In -gnatc mode, we only do annotation if -gnatt or -gnatR is also set
1074 -- as indicated by Back_Annotate_Rep_Info being set to True.
1076 -- We don't call for annotations on a subunit, because to process those
1077 -- the back-end requires that the parent(s) be properly compiled.
1079 -- Annotation is suppressed for targets where front-end layout is
1080 -- enabled, because the front end determines representations.
1082 -- Annotation is also suppressed in the case of compiling for a VM,
1083 -- since representations are largely symbolic there.
1085 if Back_End_Mode = Declarations_Only
1086 and then (not (Back_Annotate_Rep_Info or Generate_SCIL)
1087 or else Main_Kind = N_Subunit
1088 or else Targparm.Frontend_Layout_On_Target
1089 or else Targparm.VM_Target /= No_VM)
1091 Sem_Ch13.Validate_Unchecked_Conversions;
1092 Sem_Ch13.Validate_Address_Clauses;
1093 Sem_Ch13.Validate_Independence;
1094 Errout.Finalize (Last_Call => True);
1095 Errout.Output_Messages;
1096 Write_ALI (Object => False);
1104 -- Ensure that we properly register a dependency on system.ads, since
1105 -- even if we do not semantically depend on this, Targparm has read
1106 -- system parameters from the system.ads file.
1108 Lib.Writ.Ensure_System_Dependency;
1110 -- Add dependencies, if any, on preprocessing data file and on
1111 -- preprocessing definition file(s).
1113 Prepcomp.Add_Dependencies;
1115 -- Back end needs to explicitly unlock tables it needs to touch
1128 -- ???Check_Library_Items under control of a debug flag, because it
1129 -- currently does not work if the -gnatn switch (back end inlining) is
1132 if Debug_Flag_Dot_WW then
1133 Check_Library_Items;
1136 -- Here we call the back end to generate the output code
1138 Generating_Code := True;
1139 Back_End.Call_Back_End (Back_End_Mode);
1141 -- Once the backend is complete, we unlock the names table. This call
1142 -- allows a few extra entries, needed for example for the file name for
1143 -- the library file output.
1147 -- Generate the call-graph output of dispatching calls
1149 Exp_CG.Generate_CG_Output;
1151 -- Validate unchecked conversions (using the values for size and
1152 -- alignment annotated by the backend where possible).
1154 Sem_Ch13.Validate_Unchecked_Conversions;
1156 -- Validate address clauses (again using alignment values annotated
1157 -- by the backend where possible).
1159 Sem_Ch13.Validate_Address_Clauses;
1161 -- Validate independence pragmas (again using values annotated by
1162 -- the back end for component layout etc.)
1164 Sem_Ch13.Validate_Independence;
1166 -- Now we complete output of errors, rep info and the tree info. These
1167 -- are delayed till now, since it is perfectly possible for gigi to
1168 -- generate errors, modify the tree (in particular by setting flags
1169 -- indicating that elaboration is required, and also to back annotate
1170 -- representation information for List_Rep_Info.
1172 Errout.Finalize (Last_Call => True);
1173 Errout.Output_Messages;
1177 -- Only write the library if the backend did not generate any error
1178 -- messages. Otherwise signal errors to the driver program so that
1179 -- there will be no attempt to generate an object file.
1181 if Compilation_Errors then
1183 Exit_Program (E_Errors);
1186 Write_ALI (Object => (Back_End_Mode = Generate_Object));
1188 if not Compilation_Errors then
1190 -- In case of ada backends, we need to make sure that the generated
1191 -- object file has a timestamp greater than the ALI file. We do this
1192 -- to make gnatmake happy when checking the ALI and obj timestamps,
1193 -- where it expects the object file being written after the ali file.
1195 -- Gnatmake's assumption is true for gcc platforms where the gcc
1196 -- wrapper needs to call the assembler after calling gnat1, but is
1197 -- not true for ada backends, where the object files are created
1198 -- directly by gnat1 (so are created before the ali file).
1200 Back_End.Gen_Or_Update_Object_File;
1203 -- Generate ASIS tree after writing the ALI file, since in ASIS mode,
1204 -- Write_ALI may in fact result in further tree decoration from the
1205 -- original tree file. Note that we dump the tree just before generating
1206 -- it, so that the dump will exactly reflect what is written out.
1211 -- Finalize name table and we are all done
1216 -- Handle fatal internal compiler errors
1218 when Rtsfind.RE_Not_Available =>
1219 Comperr.Compiler_Abort ("RE_Not_Available");
1221 when System.Assertions.Assert_Failure =>
1222 Comperr.Compiler_Abort ("Assert_Failure");
1224 when Constraint_Error =>
1225 Comperr.Compiler_Abort ("Constraint_Error");
1227 when Program_Error =>
1228 Comperr.Compiler_Abort ("Program_Error");
1230 when Storage_Error =>
1232 -- Assume this is a bug. If it is real, the message will in any case
1233 -- say Storage_Error, giving a strong hint!
1235 Comperr.Compiler_Abort ("Storage_Error");
1241 -- The outer exception handles an unrecoverable error
1244 when Unrecoverable_Error =>
1245 Errout.Finalize (Last_Call => True);
1246 Errout.Output_Messages;
1249 Write_Str ("compilation abandoned");
1252 Set_Standard_Output;
1255 Exit_Program (E_Errors);