1 ------------------------------------------------------------------------------
3 -- GNAT COMPILER COMPONENTS --
9 -- Copyright (C) 1992-2012, Free Software Foundation, Inc. --
11 -- GNAT is free software; you can redistribute it and/or modify it under --
12 -- terms of the GNU General Public License as published by the Free Soft- --
13 -- ware Foundation; either version 3, or (at your option) any later ver- --
14 -- sion. GNAT is distributed in the hope that it will be useful, but WITH- --
15 -- OUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY --
16 -- or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License --
17 -- for more details. You should have received a copy of the GNU General --
18 -- Public License distributed with GNAT; see file COPYING3. If not, go to --
19 -- http://www.gnu.org/licenses for a complete copy of the license. --
21 -- GNAT was originally developed by the GNAT team at New York University. --
22 -- Extensive contributions were provided by Ada Core Technologies Inc. --
24 ------------------------------------------------------------------------------
26 with Atree; use Atree;
27 with Back_End; use Back_End;
29 with Csets; use Csets;
30 with Debug; use Debug;
32 with Errout; use Errout;
34 with Exp_Ch6; use Exp_Ch6;
36 with Fname; use Fname;
37 with Fname.UF; use Fname.UF;
39 with Gnatvsn; use Gnatvsn;
43 with Lib.Writ; use Lib.Writ;
45 with Namet; use Namet;
48 with Osint; use Osint;
49 with Output; use Output;
52 with Repinfo; use Repinfo;
54 with Rident; use Rident;
64 with Sinfo; use Sinfo;
65 with Sinput.L; use Sinput.L;
67 with Sprint; use Sprint;
69 with Stylesw; use Stylesw;
70 with Targparm; use Targparm;
72 with Treepr; use Treepr;
74 with Types; use Types;
75 with Uintp; use Uintp;
76 with Uname; use Uname;
79 with Validsw; use Validsw;
81 with System.Assertions;
84 Main_Unit_Node : Node_Id;
85 -- Compilation unit node for main unit
87 Main_Kind : Node_Kind;
88 -- Kind of main compilation unit node
90 Back_End_Mode : Back_End.Back_End_Mode_Type;
91 -- Record back end mode
93 procedure Adjust_Global_Switches;
94 -- There are various interactions between front end switch settings,
95 -- including debug switch settings and target dependent parameters.
96 -- This procedure takes care of properly handling these interactions.
97 -- We do it after scanning out all the switches, so that we are not
98 -- depending on the order in which switches appear.
100 procedure Check_Bad_Body;
101 -- Called to check if the unit we are compiling has a bad body
103 procedure Check_Rep_Info;
104 -- Called when we are not generating code, to check if -gnatR was requested
105 -- and if so, explain that we will not be honoring the request.
107 ----------------------------
108 -- Adjust_Global_Switches --
109 ----------------------------
111 procedure Adjust_Global_Switches is
113 -- Debug flag -gnatd.I is a synonym for Generate_SCIL and requires code
116 if Debug_Flag_Dot_II and then Operating_Mode = Generate_Code then
117 Generate_SCIL := True;
120 -- Disable CodePeer_Mode in Check_Syntax, since we need front-end
123 if Operating_Mode = Check_Syntax then
124 CodePeer_Mode := False;
127 -- Set ASIS mode if -gnatt and -gnatc are set
129 if Operating_Mode = Check_Semantics and then Tree_Output then
132 -- Turn off inlining in ASIS mode, since ASIS cannot handle the extra
133 -- information in the trees caused by inlining being active.
135 -- More specifically, the tree seems to be malformed from the ASIS
136 -- point of view if -gnatc and -gnatn appear together???
138 Inline_Active := False;
140 -- Turn off SCIL generation and CodePeer mode in semantics mode,
141 -- since SCIL requires front-end expansion.
143 Generate_SCIL := False;
144 CodePeer_Mode := False;
147 -- SCIL mode needs to disable front-end inlining since the generated
148 -- trees (in particular order and consistency between specs compiled
149 -- as part of a main unit or as part of a with-clause) are causing
152 if Generate_SCIL then
153 Front_End_Inlining := False;
156 -- Tune settings for optimal SCIL generation in CodePeer mode
158 if CodePeer_Mode then
160 -- Turn off inlining, confuses CodePeer output and gains nothing
162 Front_End_Inlining := False;
163 Inline_Active := False;
165 -- Disable front-end optimizations, to keep the tree as close to the
166 -- source code as possible, and also to avoid inconsistencies between
167 -- trees when using different optimization switches.
169 Optimization_Level := 0;
171 -- Enable some restrictions systematically to simplify the generated
172 -- code (and ease analysis). Note that restriction checks are also
173 -- disabled in CodePeer mode, see Restrict.Check_Restriction, and
174 -- user specified Restrictions pragmas are ignored, see
175 -- Sem_Prag.Process_Restrictions_Or_Restriction_Warnings.
177 Restrict.Restrictions.Set (No_Initialize_Scalars) := True;
178 Restrict.Restrictions.Set (No_Task_Hierarchy) := True;
179 Restrict.Restrictions.Set (No_Abort_Statements) := True;
180 Restrict.Restrictions.Set (Max_Asynchronous_Select_Nesting) := True;
181 Restrict.Restrictions.Value (Max_Asynchronous_Select_Nesting) := 0;
183 -- Suppress overflow, division by zero and access checks since they
184 -- are handled implicitly by CodePeer.
186 -- Turn off dynamic elaboration checks: generates inconsistencies in
187 -- trees between specs compiled as part of a main unit or as part of
190 -- Turn off alignment checks: these cannot be proved statically by
191 -- CodePeer and generate false positives.
193 -- Enable all other language checks
195 Suppress_Options.Suppress :=
196 (Access_Check => True,
197 Alignment_Check => True,
198 Division_Check => True,
199 Elaboration_Check => True,
202 Dynamic_Elaboration_Checks := False;
204 -- Kill debug of generated code, since it messes up sloc values
206 Debug_Generated_Code := False;
208 -- Turn cross-referencing on in case it was disabled (e.g. by -gnatD)
209 -- Do we really need to spend time generating xref in CodePeer
210 -- mode??? Consider setting Xref_Active to False.
214 -- Polling mode forced off, since it generates confusing junk
216 Polling_Required := False;
218 -- Set operating mode to Generate_Code to benefit from full front-end
219 -- expansion (e.g. generics).
221 Operating_Mode := Generate_Code;
223 -- We need SCIL generation of course
225 Generate_SCIL := True;
227 -- Enable assertions and debug pragmas, since they give CodePeer
228 -- valuable extra information.
230 Assertions_Enabled := True;
231 Debug_Pragmas_Enabled := True;
233 -- Disable all simple value propagation. This is an optimization
234 -- which is valuable for code optimization, and also for generation
235 -- of compiler warnings, but these are being turned off by default,
236 -- and CodePeer generates better messages (referencing original
237 -- variables) this way.
239 Debug_Flag_MM := True;
241 -- Set normal RM validity checking, and checking of IN OUT parameters
242 -- (this might give CodePeer more useful checks to analyze, to be
243 -- confirmed???). All other validity checking is turned off, since
244 -- this can generate very complex trees that only confuse CodePeer
245 -- and do not bring enough useful info.
247 Reset_Validity_Check_Options;
248 Validity_Check_Default := True;
249 Validity_Check_In_Out_Params := True;
250 Validity_Check_In_Params := True;
252 -- Turn off style check options since we are not interested in any
253 -- front-end warnings when we are getting CodePeer output.
255 Reset_Style_Check_Options;
257 -- Always perform semantics and generate ali files in CodePeer mode,
258 -- so that a gnatmake -c -k will proceed further when possible.
260 Force_ALI_Tree_File := True;
261 Try_Semantics := True;
264 -- Set Configurable_Run_Time mode if system.ads flag set
266 if Targparm.Configurable_Run_Time_On_Target or Debug_Flag_YY then
267 Configurable_Run_Time_Mode := True;
270 -- Set -gnatR3m mode if debug flag A set
272 if Debug_Flag_AA then
273 Back_Annotate_Rep_Info := True;
274 List_Representation_Info := 1;
275 List_Representation_Info_Mechanisms := True;
278 -- Force Target_Strict_Alignment true if debug flag -gnatd.a is set
280 if Debug_Flag_Dot_A then
281 Ttypes.Target_Strict_Alignment := True;
284 -- Increase size of allocated entities if debug flag -gnatd.N is set
286 if Debug_Flag_Dot_NN then
287 Atree.Num_Extension_Nodes := Atree.Num_Extension_Nodes + 1;
290 -- Disable static allocation of dispatch tables if -gnatd.t or if layout
291 -- is enabled. The front end's layout phase currently treats types that
292 -- have discriminant-dependent arrays as not being static even when a
293 -- discriminant constraint on the type is static, and this leads to
294 -- problems with subtypes of type Ada.Tags.Dispatch_Table_Wrapper. ???
296 if Debug_Flag_Dot_T or else Frontend_Layout_On_Target then
297 Static_Dispatch_Tables := False;
300 -- Flip endian mode if -gnatd8 set
303 Ttypes.Bytes_Big_Endian := not Ttypes.Bytes_Big_Endian;
306 -- Deal with forcing OpenVMS switches True if debug flag M is set, but
307 -- record the setting of Targparm.Open_VMS_On_Target in True_VMS_Target
308 -- before doing this, so we know if we are in real OpenVMS or not!
310 Opt.True_VMS_Target := Targparm.OpenVMS_On_Target;
313 Targparm.OpenVMS_On_Target := True;
314 Hostparm.OpenVMS := True;
317 -- Activate front end layout if debug flag -gnatdF is set
319 if Debug_Flag_FF then
320 Targparm.Frontend_Layout_On_Target := True;
323 -- Set and check exception mechanism
325 if Targparm.ZCX_By_Default_On_Target then
326 Exception_Mechanism := Back_End_Exceptions;
329 -- Set proper status for overflow check mechanism
331 -- If already set (by -gnato) then we have nothing to do
333 if Opt.Suppress_Options.Overflow_Checks_General /= Not_Set then
336 -- Otherwise set overflow mode defaults
339 -- Otherwise set overflow checks off by default
341 Suppress_Options.Suppress (Overflow_Check) := True;
343 -- Set appropriate default overflow handling mode. Note: at present
344 -- we set STRICT in all three of the following cases. They are
345 -- separated because in the future we may make different choices.
347 -- By default set STRICT mode if -gnatg in effect
350 Suppress_Options.Overflow_Checks_General := Strict;
351 Suppress_Options.Overflow_Checks_Assertions := Strict;
353 -- If we have backend divide and overflow checks, then by default
354 -- overflow checks are STRICT. Historically this code used to also
355 -- activate overflow checks, although no target currently has these
356 -- flags set, so this was dead code anyway.
358 elsif Targparm.Backend_Divide_Checks_On_Target
360 Targparm.Backend_Overflow_Checks_On_Target
362 Suppress_Options.Overflow_Checks_General := Strict;
363 Suppress_Options.Overflow_Checks_Assertions := Strict;
365 -- Otherwise for now, default is STRICT mode. This may change in the
366 -- future, but for now this is the compatible behavior with previous
370 Suppress_Options.Overflow_Checks_General := Strict;
371 Suppress_Options.Overflow_Checks_Assertions := Strict;
375 -- Set default for atomic synchronization. As this synchronization
376 -- between atomic accesses can be expensive, and not typically needed
377 -- on some targets, an optional target parameter can turn the option
378 -- off. Note Atomic Synchronization is implemented as check.
380 Suppress_Options.Suppress (Atomic_Synchronization) :=
381 not Atomic_Sync_Default;
383 -- Set switch indicating if we can use N_Expression_With_Actions
385 -- Debug flag -gnatd.X decisively sets usage on
387 if Debug_Flag_Dot_XX then
388 Use_Expression_With_Actions := True;
390 -- Debug flag -gnatd.Y decisively sets usage off
392 elsif Debug_Flag_Dot_YY then
393 Use_Expression_With_Actions := False;
395 -- Otherwise this feature is implemented, so we allow its use
398 Use_Expression_With_Actions := True;
401 -- Set switch indicating if back end can handle limited types, and
402 -- guarantee that no incorrect copies are made (e.g. in the context
403 -- of an if or case expression).
405 -- Debug flag -gnatd.L decisively sets usage on
407 if Debug_Flag_Dot_LL then
408 Back_End_Handles_Limited_Types := True;
410 -- If no debug flag, usage off for AAMP, VM, SCIL cases
413 or else VM_Target /= No_VM
414 or else Generate_SCIL
416 Back_End_Handles_Limited_Types := False;
418 -- Otherwise normal gcc back end, for now still turn flag off by
419 -- default, since there are unresolved problems in the front end.
422 Back_End_Handles_Limited_Types := False;
425 -- Set switches for formal verification mode
427 if Debug_Flag_Dot_VV then
428 Formal_Extensions := True;
431 if Debug_Flag_Dot_FF then
434 -- Set strict standard interpretation of compiler permissions
436 if Debug_Flag_Dot_DD then
437 Strict_Alfa_Mode := True;
440 -- Turn off inlining, which would confuse formal verification output
443 Front_End_Inlining := False;
444 Inline_Active := False;
446 -- Disable front-end optimizations, to keep the tree as close to the
447 -- source code as possible, and also to avoid inconsistencies between
448 -- trees when using different optimization switches.
450 Optimization_Level := 0;
452 -- Enable some restrictions systematically to simplify the generated
453 -- code (and ease analysis). Note that restriction checks are also
454 -- disabled in Alfa mode, see Restrict.Check_Restriction, and user
455 -- specified Restrictions pragmas are ignored, see
456 -- Sem_Prag.Process_Restrictions_Or_Restriction_Warnings.
458 Restrict.Restrictions.Set (No_Initialize_Scalars) := True;
460 -- Note: at this point we used to suppress various checks, but that
461 -- is not what we want. We need the semantic processing for these
462 -- checks (which will set flags like Do_Overflow_Check, showing the
463 -- points at which potential checks are required semantically). We
464 -- don't want the expansion associated with these checks, but that
465 -- happens anyway because this expansion is simply not done in the
466 -- Alfa version of the expander.
468 -- Kill debug of generated code, since it messes up sloc values
470 Debug_Generated_Code := False;
472 -- Turn cross-referencing on in case it was disabled (e.g. by -gnatD)
473 -- as it is needed for computing effects of subprograms in the formal
474 -- verification backend.
478 -- Polling mode forced off, since it generates confusing junk
480 Polling_Required := False;
482 -- Set operating mode to Generate_Code, but full front-end expansion
483 -- is not desirable in Alfa mode, so a light expansion is performed
486 Operating_Mode := Generate_Code;
490 Debug_Flag_HH := True;
492 -- Disable Expressions_With_Actions nodes
494 -- The gnat2why backend does not deal with Expressions_With_Actions
495 -- in all places (in particular assertions). It is difficult to
496 -- determine in the frontend which cases are allowed, so we disable
497 -- Expressions_With_Actions entirely. Even in the cases where
498 -- gnat2why deals with Expressions_With_Actions, it is easier to
499 -- deal with the original constructs (quantified, conditional and
500 -- case expressions) instead of the rewritten ones.
502 Use_Expression_With_Actions := False;
504 -- Enable assertions and debug pragmas, since they give valuable
505 -- extra information for formal verification.
507 Assertions_Enabled := True;
508 Debug_Pragmas_Enabled := True;
510 -- Turn off style check options since we are not interested in any
511 -- front-end warnings when we are getting Alfa output.
513 Reset_Style_Check_Options;
515 -- Suppress compiler warnings, since what we are interested in here
516 -- is what formal verification can find out.
518 Warning_Mode := Suppress;
520 -- Suppress the generation of name tables for enumerations, which are
521 -- not needed for formal verification, and fall outside the Alfa
522 -- subset (use of pointers).
524 Global_Discard_Names := True;
526 -- Suppress the expansion of tagged types and dispatching calls,
527 -- which lead to the generation of non-Alfa code (use of pointers),
528 -- which is more complex to formally verify than the original source.
530 Tagged_Type_Expansion := False;
533 -- If the inlining level has not been set by the user, compute it from
534 -- the optimization level: 1 at -O1/-O2 (and -Os), 2 at -O3 and above.
536 if Inline_Level = 0 then
537 if Optimization_Level < 3 then
544 -- Finally capture adjusted value of Suppress_Options as the initial
545 -- value for Scope_Suppress, which will be modified as we move from
546 -- scope to scope (by Suppress/Unsuppress/Overflow_Checks pragmas).
548 Sem.Scope_Suppress := Opt.Suppress_Options;
549 end Adjust_Global_Switches;
555 procedure Check_Bad_Body is
556 Sname : Unit_Name_Type;
557 Src_Ind : Source_File_Index;
558 Fname : File_Name_Type;
560 procedure Bad_Body_Error (Msg : String);
561 -- Issue message for bad body found
567 procedure Bad_Body_Error (Msg : String) is
569 Error_Msg_N (Msg, Main_Unit_Node);
570 Error_Msg_File_1 := Fname;
571 Error_Msg_N ("remove incorrect body in file{!", Main_Unit_Node);
574 -- Start of processing for Check_Bad_Body
577 -- Nothing to do if we are only checking syntax, because we don't know
578 -- enough to know if we require or forbid a body in this case.
580 if Operating_Mode = Check_Syntax then
584 -- Check for body not allowed
586 if (Main_Kind = N_Package_Declaration
587 and then not Body_Required (Main_Unit_Node))
588 or else (Main_Kind = N_Generic_Package_Declaration
589 and then not Body_Required (Main_Unit_Node))
590 or else Main_Kind = N_Package_Renaming_Declaration
591 or else Main_Kind = N_Subprogram_Renaming_Declaration
592 or else Nkind (Original_Node (Unit (Main_Unit_Node)))
593 in N_Generic_Instantiation
595 Sname := Unit_Name (Main_Unit);
597 -- If we do not already have a body name, then get the body name
598 -- (but how can we have a body name here???)
600 if not Is_Body_Name (Sname) then
601 Sname := Get_Body_Name (Sname);
604 Fname := Get_File_Name (Sname, Subunit => False);
605 Src_Ind := Load_Source_File (Fname);
607 -- Case where body is present and it is not a subunit. Exclude the
608 -- subunit case, because it has nothing to do with the package we are
609 -- compiling. It is illegal for a child unit and a subunit with the
610 -- same expanded name (RM 10.2(9)) to appear together in a partition,
611 -- but there is nothing to stop a compilation environment from having
612 -- both, and the test here simply allows that. If there is an attempt
613 -- to include both in a partition, this is diagnosed at bind time. In
614 -- Ada 83 mode this is not a warning case.
616 -- Note: if weird file names are being used, we can have a situation
617 -- where the file name that supposedly contains body in fact contains
618 -- a spec, or we can't tell what it contains. Skip the error message
621 -- Also ignore body that is nothing but pragma No_Body; (that's the
622 -- whole point of this pragma, to be used this way and to cause the
623 -- body file to be ignored in this context).
625 if Src_Ind /= No_Source_File
626 and then Get_Expected_Unit_Type (Fname) = Expect_Body
627 and then not Source_File_Is_Subunit (Src_Ind)
628 and then not Source_File_Is_No_Body (Src_Ind)
630 Errout.Finalize (Last_Call => False);
632 Error_Msg_Unit_1 := Sname;
634 -- Ada 83 case of a package body being ignored. This is not an
635 -- error as far as the Ada 83 RM is concerned, but it is almost
636 -- certainly not what is wanted so output a warning. Give this
637 -- message only if there were no errors, since otherwise it may
638 -- be incorrect (we may have misinterpreted a junk spec as not
639 -- needing a body when it really does).
641 if Main_Kind = N_Package_Declaration
642 and then Ada_Version = Ada_83
643 and then Operating_Mode = Generate_Code
644 and then Distribution_Stub_Mode /= Generate_Caller_Stub_Body
645 and then not Compilation_Errors
648 ("package $$ does not require a body?", Main_Unit_Node);
649 Error_Msg_File_1 := Fname;
650 Error_Msg_N ("body in file{? will be ignored", Main_Unit_Node);
652 -- Ada 95 cases of a body file present when no body is
653 -- permitted. This we consider to be an error.
656 -- For generic instantiations, we never allow a body
658 if Nkind (Original_Node (Unit (Main_Unit_Node)))
659 in N_Generic_Instantiation
662 ("generic instantiation for $$ does not allow a body");
664 -- A library unit that is a renaming never allows a body
666 elsif Main_Kind in N_Renaming_Declaration then
668 ("renaming declaration for $$ does not allow a body!");
670 -- Remaining cases are packages and generic packages. Here
671 -- we only do the test if there are no previous errors,
672 -- because if there are errors, they may lead us to
673 -- incorrectly believe that a package does not allow a body
674 -- when in fact it does.
676 elsif not Compilation_Errors then
677 if Main_Kind = N_Package_Declaration then
679 ("package $$ does not allow a body!");
681 elsif Main_Kind = N_Generic_Package_Declaration then
683 ("generic package $$ does not allow a body!");
696 procedure Check_Rep_Info is
698 if List_Representation_Info /= 0
699 or else List_Representation_Info_Mechanisms
704 ("cannot generate representation information, no code generated");
711 -- Start of processing for Gnat1drv
714 -- This inner block is set up to catch assertion errors and constraint
715 -- errors. Since the code for handling these errors can cause another
716 -- exception to be raised (namely Unrecoverable_Error), we need two
717 -- nested blocks, so that the outer one handles unrecoverable error.
720 -- Initialize all packages. For the most part, these initialization
721 -- calls can be made in any order. Exceptions are as follows:
723 -- Lib.Initialize need to be called before Scan_Compiler_Arguments,
724 -- because it initializes a table filled by Scan_Compiler_Arguments.
730 Scan_Compiler_Arguments;
731 Osint.Add_Default_Search_Dirs;
751 Sem_Type.Init_Interp_Tables;
753 -- Acquire target parameters from system.ads (source of package System)
758 S : Source_File_Index;
762 Name_Buffer (1 .. 10) := "system.ads";
765 S := Load_Source_File (N);
767 if S = No_Source_File then
769 ("fatal error, run-time library not installed correctly");
770 Write_Line ("cannot locate file system.ads");
771 raise Unrecoverable_Error;
773 -- Remember source index of system.ads (which was read successfully)
776 System_Source_File_Index := S;
779 Targparm.Get_Target_Parameters
780 (System_Text => Source_Text (S),
781 Source_First => Source_First (S),
782 Source_Last => Source_Last (S));
784 -- Acquire configuration pragma information from Targparm
786 Restrict.Restrictions := Targparm.Restrictions_On_Target;
789 Adjust_Global_Switches;
791 -- Output copyright notice if full list mode unless we have a list
792 -- file, in which case we defer this so that it is output in the file
794 if (Verbose_Mode or else (Full_List and then Full_List_File_Name = null))
795 and then not Debug_Flag_7
799 Write_Str (Gnat_Version_String);
801 Write_Str ("Copyright 1992-" & Current_Year
802 & ", Free Software Foundation, Inc.");
806 -- Check we do not have more than one source file, this happens only in
807 -- the case where the driver is called directly, it cannot happen when
808 -- gnat1 is invoked from gcc in the normal case.
810 if Osint.Number_Of_Files /= 1 then
813 Osint.Fail ("you must provide one source file");
815 elsif Usage_Requested then
819 Original_Operating_Mode := Operating_Mode;
822 -- Exit with errors if the main source could not be parsed. Also, when
823 -- -gnatd.H is present, the source file is not set.
825 if Sinput.Main_Source_File = No_Source_File then
827 -- Handle -gnatd.H debug mode
829 if Debug_Flag_Dot_HH then
831 -- For -gnatd.H, lock all the tables to keep the convention that
832 -- the backend needs to unlock the tables it wants to touch.
845 -- And all we need to do is to call the back end
847 Back_End.Call_Back_End (Back_End.Generate_Object);
850 Errout.Finalize (Last_Call => True);
851 Errout.Output_Messages;
852 Exit_Program (E_Errors);
855 Main_Unit_Node := Cunit (Main_Unit);
856 Main_Kind := Nkind (Unit (Main_Unit_Node));
859 -- In CodePeer mode we always delete old SCIL files before regenerating
860 -- new ones, in case of e.g. errors, and also to remove obsolete scilx
861 -- files generated by CodePeer itself.
863 if CodePeer_Mode then
864 Comperr.Delete_SCIL_Files;
867 -- Exit if compilation errors detected
869 Errout.Finalize (Last_Call => False);
871 if Compilation_Errors then
873 Sem_Ch13.Validate_Unchecked_Conversions;
874 Sem_Ch13.Validate_Address_Clauses;
875 Sem_Ch13.Validate_Independence;
876 Errout.Output_Messages;
879 -- Generate ALI file if specially requested
881 if Opt.Force_ALI_Tree_File then
882 Write_ALI (Object => False);
886 Errout.Finalize (Last_Call => True);
887 Exit_Program (E_Errors);
890 -- Set Generate_Code on main unit and its spec. We do this even if are
891 -- not generating code, since Lib-Writ uses this to determine which
892 -- units get written in the ali file.
894 Set_Generate_Code (Main_Unit);
896 -- If we have a corresponding spec, and it comes from source or it is
897 -- not a generated spec for a child subprogram body, then we need object
898 -- code for the spec unit as well.
900 if Nkind (Unit (Main_Unit_Node)) in N_Unit_Body
901 and then not Acts_As_Spec (Main_Unit_Node)
903 if Nkind (Unit (Main_Unit_Node)) = N_Subprogram_Body
904 and then not Comes_From_Source (Library_Unit (Main_Unit_Node))
909 (Get_Cunit_Unit_Number (Library_Unit (Main_Unit_Node)));
913 -- Case of no code required to be generated, exit indicating no error
915 if Original_Operating_Mode = Check_Syntax then
917 Errout.Finalize (Last_Call => True);
918 Errout.Output_Messages;
923 -- Use a goto instead of calling Exit_Program so that finalization
928 elsif Original_Operating_Mode = Check_Semantics then
929 Back_End_Mode := Declarations_Only;
931 -- All remaining cases are cases in which the user requested that code
932 -- be generated (i.e. no -gnatc or -gnats switch was used). Check if we
933 -- can in fact satisfy this request.
935 -- Cannot generate code if someone has turned off code generation for
936 -- any reason at all. We will try to figure out a reason below.
938 elsif Operating_Mode /= Generate_Code then
939 Back_End_Mode := Skip;
941 -- We can generate code for a subprogram body unless there were missing
942 -- subunits. Note that we always generate code for all generic units (a
943 -- change from some previous versions of GNAT).
945 elsif Main_Kind = N_Subprogram_Body and then not Subunits_Missing then
946 Back_End_Mode := Generate_Object;
948 -- We can generate code for a package body unless there are subunits
949 -- missing (note that we always generate code for generic units, which
950 -- is a change from some earlier versions of GNAT).
952 elsif Main_Kind = N_Package_Body and then not Subunits_Missing then
953 Back_End_Mode := Generate_Object;
955 -- We can generate code for a package declaration or a subprogram
956 -- declaration only if it does not required a body.
958 elsif Nkind_In (Main_Kind,
959 N_Package_Declaration,
960 N_Subprogram_Declaration)
962 (not Body_Required (Main_Unit_Node)
964 Distribution_Stub_Mode = Generate_Caller_Stub_Body)
966 Back_End_Mode := Generate_Object;
968 -- We can generate code for a generic package declaration of a generic
969 -- subprogram declaration only if does not require a body.
971 elsif Nkind_In (Main_Kind, N_Generic_Package_Declaration,
972 N_Generic_Subprogram_Declaration)
973 and then not Body_Required (Main_Unit_Node)
975 Back_End_Mode := Generate_Object;
977 -- Compilation units that are renamings do not require bodies, so we can
978 -- generate code for them.
980 elsif Nkind_In (Main_Kind, N_Package_Renaming_Declaration,
981 N_Subprogram_Renaming_Declaration)
983 Back_End_Mode := Generate_Object;
985 -- Compilation units that are generic renamings do not require bodies
986 -- so we can generate code for them.
988 elsif Main_Kind in N_Generic_Renaming_Declaration then
989 Back_End_Mode := Generate_Object;
991 -- It's not an error to generate SCIL for e.g. a spec which has a body
993 elsif CodePeer_Mode then
994 Back_End_Mode := Generate_Object;
996 -- In all other cases (specs which have bodies, generics, and bodies
997 -- where subunits are missing), we cannot generate code and we generate
998 -- a warning message. Note that generic instantiations are gone at this
999 -- stage since they have been replaced by their instances.
1002 Back_End_Mode := Skip;
1005 -- At this stage Back_End_Mode is set to indicate if the backend should
1006 -- be called to generate code. If it is Skip, then code generation has
1007 -- been turned off, even though code was requested by the original
1008 -- command. This is not an error from the user point of view, but it is
1009 -- an error from the point of view of the gcc driver, so we must exit
1010 -- with an error status.
1012 -- We generate an informative message (from the gcc point of view, it
1013 -- is an error message, but from the users point of view this is not an
1014 -- error, just a consequence of compiling something that cannot
1017 if Back_End_Mode = Skip then
1019 Write_Str ("cannot generate code for ");
1020 Write_Str ("file ");
1021 Write_Name (Unit_File_Name (Main_Unit));
1023 if Subunits_Missing then
1024 Write_Str (" (missing subunits)");
1027 -- Force generation of ALI file, for backward compatibility
1029 Opt.Force_ALI_Tree_File := True;
1031 elsif Main_Kind = N_Subunit then
1032 Write_Str (" (subunit)");
1035 -- Force generation of ALI file, for backward compatibility
1037 Opt.Force_ALI_Tree_File := True;
1039 elsif Main_Kind = N_Subprogram_Declaration then
1040 Write_Str (" (subprogram spec)");
1043 -- Generic package body in GNAT implementation mode
1045 elsif Main_Kind = N_Package_Body and then GNAT_Mode then
1046 Write_Str (" (predefined generic)");
1049 -- Force generation of ALI file, for backward compatibility
1051 Opt.Force_ALI_Tree_File := True;
1053 -- Only other case is a package spec
1056 Write_Str (" (package spec)");
1060 Set_Standard_Output;
1062 Sem_Ch13.Validate_Unchecked_Conversions;
1063 Sem_Ch13.Validate_Address_Clauses;
1064 Sem_Ch13.Validate_Independence;
1065 Errout.Finalize (Last_Call => True);
1066 Errout.Output_Messages;
1070 -- Generate ALI file if specially requested, or for missing subunits,
1071 -- subunits or predefined generic.
1073 if Opt.Force_ALI_Tree_File then
1074 Write_ALI (Object => False);
1080 -- Exit program with error indication, to kill object file
1082 Exit_Program (E_No_Code);
1085 -- In -gnatc mode, we only do annotation if -gnatt or -gnatR is also set
1086 -- as indicated by Back_Annotate_Rep_Info being set to True.
1088 -- We don't call for annotations on a subunit, because to process those
1089 -- the back-end requires that the parent(s) be properly compiled.
1091 -- Annotation is suppressed for targets where front-end layout is
1092 -- enabled, because the front end determines representations.
1094 -- Annotation is also suppressed in the case of compiling for a VM,
1095 -- since representations are largely symbolic there.
1097 if Back_End_Mode = Declarations_Only
1098 and then (not (Back_Annotate_Rep_Info or Generate_SCIL)
1099 or else Main_Kind = N_Subunit
1100 or else Targparm.Frontend_Layout_On_Target
1101 or else Targparm.VM_Target /= No_VM)
1103 Sem_Ch13.Validate_Unchecked_Conversions;
1104 Sem_Ch13.Validate_Address_Clauses;
1105 Sem_Ch13.Validate_Independence;
1106 Errout.Finalize (Last_Call => True);
1107 Errout.Output_Messages;
1108 Write_ALI (Object => False);
1116 -- Ensure that we properly register a dependency on system.ads, since
1117 -- even if we do not semantically depend on this, Targparm has read
1118 -- system parameters from the system.ads file.
1120 Lib.Writ.Ensure_System_Dependency;
1122 -- Add dependencies, if any, on preprocessing data file and on
1123 -- preprocessing definition file(s).
1125 Prepcomp.Add_Dependencies;
1127 -- Back end needs to explicitly unlock tables it needs to touch
1140 -- Here we call the back end to generate the output code
1142 Generating_Code := True;
1143 Back_End.Call_Back_End (Back_End_Mode);
1145 -- Once the backend is complete, we unlock the names table. This call
1146 -- allows a few extra entries, needed for example for the file name for
1147 -- the library file output.
1151 -- Generate the call-graph output of dispatching calls
1153 Exp_CG.Generate_CG_Output;
1155 -- Validate unchecked conversions (using the values for size and
1156 -- alignment annotated by the backend where possible).
1158 Sem_Ch13.Validate_Unchecked_Conversions;
1160 -- Validate address clauses (again using alignment values annotated
1161 -- by the backend where possible).
1163 Sem_Ch13.Validate_Address_Clauses;
1165 -- Validate independence pragmas (again using values annotated by
1166 -- the back end for component layout etc.)
1168 Sem_Ch13.Validate_Independence;
1170 -- Now we complete output of errors, rep info and the tree info. These
1171 -- are delayed till now, since it is perfectly possible for gigi to
1172 -- generate errors, modify the tree (in particular by setting flags
1173 -- indicating that elaboration is required, and also to back annotate
1174 -- representation information for List_Rep_Info.
1176 Errout.Finalize (Last_Call => True);
1177 Errout.Output_Messages;
1181 -- Only write the library if the backend did not generate any error
1182 -- messages. Otherwise signal errors to the driver program so that
1183 -- there will be no attempt to generate an object file.
1185 if Compilation_Errors then
1187 Exit_Program (E_Errors);
1190 Write_ALI (Object => (Back_End_Mode = Generate_Object));
1192 if not Compilation_Errors then
1194 -- In case of ada backends, we need to make sure that the generated
1195 -- object file has a timestamp greater than the ALI file. We do this
1196 -- to make gnatmake happy when checking the ALI and obj timestamps,
1197 -- where it expects the object file being written after the ali file.
1199 -- Gnatmake's assumption is true for gcc platforms where the gcc
1200 -- wrapper needs to call the assembler after calling gnat1, but is
1201 -- not true for ada backends, where the object files are created
1202 -- directly by gnat1 (so are created before the ali file).
1204 Back_End.Gen_Or_Update_Object_File;
1207 -- Generate ASIS tree after writing the ALI file, since in ASIS mode,
1208 -- Write_ALI may in fact result in further tree decoration from the
1209 -- original tree file. Note that we dump the tree just before generating
1210 -- it, so that the dump will exactly reflect what is written out.
1215 -- Finalize name table and we are all done
1220 -- Handle fatal internal compiler errors
1222 when Rtsfind.RE_Not_Available =>
1223 Comperr.Compiler_Abort ("RE_Not_Available");
1225 when System.Assertions.Assert_Failure =>
1226 Comperr.Compiler_Abort ("Assert_Failure");
1228 when Constraint_Error =>
1229 Comperr.Compiler_Abort ("Constraint_Error");
1231 when Program_Error =>
1232 Comperr.Compiler_Abort ("Program_Error");
1234 when Storage_Error =>
1236 -- Assume this is a bug. If it is real, the message will in any case
1237 -- say Storage_Error, giving a strong hint!
1239 Comperr.Compiler_Abort ("Storage_Error");
1245 -- The outer exception handles an unrecoverable error
1248 when Unrecoverable_Error =>
1249 Errout.Finalize (Last_Call => True);
1250 Errout.Output_Messages;
1253 Write_Str ("compilation abandoned");
1256 Set_Standard_Output;
1259 Exit_Program (E_Errors);