1 ------------------------------------------------------------------------------
3 -- GNAT COMPILER COMPONENTS --
9 -- Copyright (C) 1992-2007, 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 Debug; use Debug;
28 with Einfo; use Einfo;
29 with Errout; use Errout;
30 with Fname; use Fname;
31 with Fname.UF; use Fname.UF;
32 with Nlists; use Nlists;
33 with Nmake; use Nmake;
35 with Osint; use Osint;
36 with Osint.C; use Osint.C;
37 with Output; use Output;
39 with Restrict; use Restrict;
41 with Sinfo; use Sinfo;
42 with Sinput; use Sinput;
43 with Sinput.L; use Sinput.L;
44 with Stand; use Stand;
45 with Tbuild; use Tbuild;
46 with Uname; use Uname;
48 package body Lib.Load is
50 -----------------------
51 -- Local Subprograms --
52 -----------------------
54 function From_Limited_With_Chain return Boolean;
55 -- Check whether a possible circular dependence includes units that
56 -- have been loaded through limited_with clauses, in which case there
57 -- is no real circularity.
59 function Spec_Is_Irrelevant
60 (Spec_Unit : Unit_Number_Type;
61 Body_Unit : Unit_Number_Type) return Boolean;
62 -- The Spec_Unit and Body_Unit parameters are the unit numbers of the
63 -- spec file that corresponds to the main unit which is a body. This
64 -- function determines if the spec file is irrelevant and will be
65 -- overridden by the body as described in RM 10.1.4(4). See description
66 -- in "Special Handling of Subprogram Bodies" for further details.
68 procedure Write_Dependency_Chain;
69 -- This procedure is used to generate error message info lines that
70 -- trace the current dependency chain when a load error occurs.
72 ------------------------------
73 -- Change_Main_Unit_To_Spec --
74 ------------------------------
76 procedure Change_Main_Unit_To_Spec is
77 U : Unit_Record renames Units.Table (Main_Unit);
79 X : Source_File_Index;
82 -- Get name of unit body
84 Get_Name_String (U.Unit_File_Name);
86 -- Note: for the following we should really generalize and consult the
87 -- file name pattern data, but for now we just deal with the common
88 -- naming cases, which is probably good enough in practice ???
90 -- Change .adb to .ads
93 and then Name_Buffer (Name_Len - 3 .. Name_Len) = ".adb"
95 Name_Buffer (Name_Len) := 's';
97 -- Change .2.ada to .1.ada (Rational convention)
100 and then Name_Buffer (Name_Len - 5 .. Name_Len) = ".2.ada"
102 Name_Buffer (Name_Len - 4) := '1';
104 -- Change .ada to _.ada (DEC convention)
107 and then Name_Buffer (Name_Len - 3 .. Name_Len) = ".ada"
109 Name_Buffer (Name_Len - 3 .. Name_Len + 1) := "_.ada";
110 Name_Len := Name_Len + 1;
112 -- No match, don't make the change
118 -- Try loading the spec
121 X := Load_Source_File (N);
123 -- No change if we did not find the spec
125 if X = No_Source_File then
129 -- Otherwise modify Main_Unit entry to point to spec
131 U.Unit_File_Name := N;
133 end Change_Main_Unit_To_Spec;
135 -------------------------------
136 -- Create_Dummy_Package_Unit --
137 -------------------------------
139 function Create_Dummy_Package_Unit
140 (With_Node : Node_Id;
141 Spec_Name : Unit_Name_Type) return Unit_Number_Type
143 Unum : Unit_Number_Type;
144 Cunit_Entity : Entity_Id;
146 Du_Name : Node_Or_Entity_Id;
148 Save_CS : constant Boolean := Get_Comes_From_Source_Default;
151 -- The created dummy package unit does not come from source
153 Set_Comes_From_Source_Default (False);
157 if Nkind (Name (With_Node)) = N_Identifier then
159 Make_Defining_Identifier (No_Location,
160 Chars => Chars (Name (With_Node)));
161 Du_Name := Cunit_Entity;
162 End_Lab := New_Occurrence_Of (Cunit_Entity, No_Location);
168 Make_Defining_Identifier (No_Location,
169 Chars => Chars (Selector_Name (Name (With_Node))));
171 Make_Defining_Program_Unit_Name (No_Location,
172 Name => New_Copy_Tree (Prefix (Name (With_Node))),
173 Defining_Identifier => Cunit_Entity);
175 Set_Is_Child_Unit (Cunit_Entity);
178 Make_Designator (No_Location,
179 Name => New_Copy_Tree (Prefix (Name (With_Node))),
180 Identifier => New_Occurrence_Of (Cunit_Entity, No_Location));
183 Set_Scope (Cunit_Entity, Standard_Standard);
186 Make_Compilation_Unit (No_Location,
187 Context_Items => Empty_List,
189 Make_Package_Declaration (No_Location,
191 Make_Package_Specification (No_Location,
192 Defining_Unit_Name => Du_Name,
193 Visible_Declarations => Empty_List,
194 End_Label => End_Lab)),
196 Make_Compilation_Unit_Aux (No_Location));
198 -- Mark the dummy package as analyzed to prevent analysis of this
199 -- (non-existent) unit in -gnatQ mode because at the moment the
200 -- structure and attributes of this dummy package does not allow
201 -- a normal analysis of this unit
203 Set_Analyzed (Cunit);
205 Units.Increment_Last;
208 Units.Table (Unum) := (
210 Cunit_Entity => Cunit_Entity,
212 Dynamic_Elab => False,
213 Error_Location => Sloc (With_Node),
214 Expected_Unit => Spec_Name,
216 Generate_Code => False,
218 Ident_String => Empty,
220 Main_Priority => Default_Main_Priority,
223 Source_Index => No_Source_File,
224 Unit_File_Name => Get_File_Name (Spec_Name, Subunit => False),
225 Unit_Name => Spec_Name,
228 Set_Comes_From_Source_Default (Save_CS);
229 Set_Error_Posted (Cunit_Entity);
230 Set_Error_Posted (Cunit);
232 end Create_Dummy_Package_Unit;
234 -----------------------------
235 -- From_Limited_With_Chain --
236 -----------------------------
238 function From_Limited_With_Chain return Boolean is
239 Curr_Num : constant Unit_Number_Type :=
240 Load_Stack.Table (Load_Stack.Last).Unit_Number;
243 -- True if the current load operation is through a limited_with clause
244 -- and we are not within a loop of regular with_clauses.
246 for U in reverse Load_Stack.First .. Load_Stack.Last - 1 loop
247 if Load_Stack.Table (U).Unit_Number = Curr_Num then
250 elsif Present (Load_Stack.Table (U).With_Node)
251 and then Limited_Present (Load_Stack.Table (U).With_Node)
258 end From_Limited_With_Chain;
264 procedure Initialize is
270 ------------------------
271 -- Initialize_Version --
272 ------------------------
274 procedure Initialize_Version (U : Unit_Number_Type) is
276 Units.Table (U).Version := Source_Checksum (Source_Index (U));
277 end Initialize_Version;
279 ----------------------
280 -- Load_Main_Source --
281 ----------------------
283 procedure Load_Main_Source is
284 Fname : File_Name_Type;
288 Load_Stack.Increment_Last;
289 Load_Stack.Table (Load_Stack.Last) := (Main_Unit, Empty);
291 -- Initialize unit table entry for Main_Unit. Note that we don't know
292 -- the unit name yet, that gets filled in when the parser parses the
293 -- main unit, at which time a check is made that it matches the main
294 -- file name, and then the Unit_Name field is set. The Cunit and
295 -- Cunit_Entity fields also get filled in later by the parser.
297 Units.Increment_Last;
298 Fname := Next_Main_Source;
300 Units.Table (Main_Unit).Unit_File_Name := Fname;
302 if Fname /= No_File then
303 Main_Source_File := Load_Source_File (Fname);
304 Current_Error_Source_File := Main_Source_File;
306 if Main_Source_File /= No_Source_File then
307 Version := Source_Checksum (Main_Source_File);
310 Units.Table (Main_Unit) := (
312 Cunit_Entity => Empty,
314 Dynamic_Elab => False,
315 Error_Location => No_Location,
316 Expected_Unit => No_Unit_Name,
317 Fatal_Error => False,
318 Generate_Code => False,
320 Ident_String => Empty,
322 Main_Priority => Default_Main_Priority,
325 Source_Index => Main_Source_File,
326 Unit_File_Name => Fname,
327 Unit_Name => No_Unit_Name,
330 end Load_Main_Source;
337 (Load_Name : Unit_Name_Type;
339 Error_Node : Node_Id;
341 Corr_Body : Unit_Number_Type := No_Unit;
342 Renamings : Boolean := False;
343 With_Node : Node_Id := Empty) return Unit_Number_Type
345 Calling_Unit : Unit_Number_Type;
346 Uname_Actual : Unit_Name_Type;
347 Unum : Unit_Number_Type;
348 Unump : Unit_Number_Type;
349 Fname : File_Name_Type;
350 Src_Ind : Source_File_Index;
352 -- Start of processing for Load_Unit
355 -- If renamings are allowed and we have a child unit name, then we
356 -- must first load the parent to deal with finding the real name.
358 if Renamings and then Is_Child_Name (Load_Name) then
361 (Load_Name => Get_Parent_Spec_Name (Load_Name),
362 Required => Required,
365 Error_Node => Error_Node);
367 if Unump = No_Unit then
371 -- If parent is a renaming, then we use the renamed package as
372 -- the actual parent for the subsequent load operation.
374 if Nkind (Unit (Cunit (Unump))) = N_Package_Renaming_Declaration then
377 (Load_Name, Get_Unit_Name (Name (Unit (Cunit (Unump)))));
379 -- Save the renaming entity, to establish its visibility when
380 -- installing the context. The implicit with is on this entity,
381 -- not on the package it renames.
383 if Nkind (Error_Node) = N_With_Clause
384 and then Nkind (Name (Error_Node)) = N_Selected_Component
387 Par : Node_Id := Name (Error_Node);
390 while Nkind (Par) = N_Selected_Component
391 and then Chars (Selector_Name (Par)) /=
392 Chars (Cunit_Entity (Unump))
397 -- Case of some intermediate parent is a renaming
399 if Nkind (Par) = N_Selected_Component then
400 Set_Entity (Selector_Name (Par), Cunit_Entity (Unump));
402 -- Case where the ultimate parent is a renaming
405 Set_Entity (Par, Cunit_Entity (Unump));
410 -- If the parent is not a renaming, then get its name (this may
411 -- be different from the parent spec name obtained above because
412 -- of renamings higher up in the hierarchy).
415 Uname_Actual := New_Child (Load_Name, Unit_Name (Unump));
418 -- Here if unit to be loaded is not a child unit
421 Uname_Actual := Load_Name;
424 Fname := Get_File_Name (Uname_Actual, Subunit);
428 Write_Str ("*** Load request for unit: ");
429 Write_Unit_Name (Load_Name);
432 Write_Str (" (Required = True)");
434 Write_Str (" (Required = False)");
439 if Uname_Actual /= Load_Name then
440 Write_Str ("*** Actual unit loaded: ");
441 Write_Unit_Name (Uname_Actual);
445 -- Capture error location if it is for the main unit. The idea is to
446 -- post errors on the main unit location, not the most recent unit.
447 -- Note: Unit_Name (Main_Unit) is not set if we are parsing gnat.adc.
449 if Present (Error_Node)
450 and then Unit_Name (Main_Unit) /= No_Unit_Name
452 -- It seems like In_Extended_Main_Source_Unit (Error_Node) would
453 -- do the trick here, but that's wrong, it is much too early to
454 -- call this routine. We are still in the parser, and the required
455 -- semantic information is not established yet. So we base the
456 -- judgment on unit names.
458 Get_External_Unit_Name_String (Unit_Name (Main_Unit));
461 Main_Unit_Name : constant String := Name_Buffer (1 .. Name_Len);
464 Get_External_Unit_Name_String
465 (Unit_Name (Get_Source_Unit (Error_Node)));
467 -- If the two names are identical, then for sure we are part
468 -- of the extended main unit
470 if Main_Unit_Name = Name_Buffer (1 .. Name_Len) then
471 Load_Msg_Sloc := Sloc (Error_Node);
473 -- If the load is called from a with_type clause, the error
476 -- Otherwise, check for the subunit case, and if so, consider
477 -- we have a match if one name is a prefix of the other name.
480 if Nkind (Unit (Cunit (Main_Unit))) = N_Subunit
482 Nkind (Unit (Cunit (Get_Source_Unit (Error_Node)))) =
485 Name_Len := Integer'Min (Name_Len, Main_Unit_Name'Length);
487 if Name_Buffer (1 .. Name_Len)
489 Main_Unit_Name (1 .. Name_Len)
491 Load_Msg_Sloc := Sloc (Error_Node);
498 -- If we are generating error messages, then capture calling unit
500 if Present (Error_Node) then
501 Calling_Unit := Get_Source_Unit (Error_Node);
503 Calling_Unit := No_Unit;
506 -- See if we already have an entry for this unit
510 while Unum <= Units.Last loop
511 exit when Uname_Actual = Units.Table (Unum).Unit_Name;
515 -- Whether or not the entry was found, Unum is now the right value,
516 -- since it is one more than Units.Last (i.e. the index of the new
517 -- entry we will create) in the not found case.
519 -- A special check is necessary in the unit not found case. If the unit
520 -- is not found, but the file in which it lives has already been loaded,
521 -- then we have the problem that the file does not contain the unit that
522 -- is needed. We simply treat this as a file not found condition.
524 -- We skip this test in multiple unit per file mode since in this
525 -- case we can have multiple units from the same source file.
527 if Unum > Units.Last and then Get_Unit_Index (Uname_Actual) = 0 then
528 for J in Units.First .. Units.Last loop
529 if Fname = Units.Table (J).Unit_File_Name then
531 Write_Str (" file does not contain unit, Unit_Number = ");
532 Write_Int (Int (Unum));
537 if Present (Error_Node) then
538 if Is_Predefined_File_Name (Fname) then
539 Error_Msg_Unit_1 := Uname_Actual;
541 ("$$ is not a language defined unit", Load_Msg_Sloc);
543 Error_Msg_File_1 := Fname;
544 Error_Msg_Unit_1 := Uname_Actual;
545 Error_Msg ("File{ does not contain unit$", Load_Msg_Sloc);
548 Write_Dependency_Chain;
558 -- If we are proceeding with load, then make load stack entry,
559 -- and indicate the kind of with_clause responsible for the load.
561 Load_Stack.Increment_Last;
562 Load_Stack.Table (Load_Stack.Last) := (Unum, With_Node);
564 -- Case of entry already in table
566 if Unum <= Units.Last then
568 -- Here is where we check for a circular dependency, which is
569 -- an attempt to load a unit which is currently in the process
570 -- of being loaded. We do *not* care about a circular chain that
571 -- leads back to a body, because this kind of circular dependence
572 -- legitimately occurs (e.g. two package bodies that contain
573 -- inlined subprogram referenced by the other).
575 -- Ada 2005 (AI-50217): We also ignore limited_with clauses, because
576 -- their purpose is precisely to create legal circular structures.
579 and then (Is_Spec_Name (Units.Table (Unum).Unit_Name)
580 or else Acts_As_Spec (Units.Table (Unum).Cunit))
581 and then (Nkind (Error_Node) /= N_With_Clause
582 or else not Limited_Present (Error_Node))
583 and then not From_Limited_With_Chain
586 Write_Str (" circular dependency encountered");
590 if Present (Error_Node) then
591 Error_Msg ("circular unit dependency", Load_Msg_Sloc);
592 Write_Dependency_Chain;
594 Load_Stack.Decrement_Last;
601 Write_Str (" unit already in file table, Unit_Number = ");
602 Write_Int (Int (Unum));
606 Load_Stack.Decrement_Last;
609 -- Unit is not already in table, so try to open the file
613 Write_Str (" attempt unit load, Unit_Number = ");
614 Write_Int (Int (Unum));
618 Src_Ind := Load_Source_File (Fname);
620 -- Make a partial entry in the file table, used even in the file not
621 -- found case to print the dependency chain including the last entry
623 Units.Increment_Last;
624 Units.Table (Unum).Unit_Name := Uname_Actual;
628 if Src_Ind /= No_Source_File then
629 Units.Table (Unum) := (
631 Cunit_Entity => Empty,
633 Dynamic_Elab => False,
634 Error_Location => Sloc (Error_Node),
635 Expected_Unit => Uname_Actual,
636 Fatal_Error => False,
637 Generate_Code => False,
639 Ident_String => Empty,
641 Main_Priority => Default_Main_Priority,
644 Source_Index => Src_Ind,
645 Unit_File_Name => Fname,
646 Unit_Name => Uname_Actual,
647 Version => Source_Checksum (Src_Ind));
649 -- Parse the new unit
652 Save_Index : constant Nat := Multiple_Unit_Index;
654 Multiple_Unit_Index := Get_Unit_Index (Uname_Actual);
655 Units.Table (Unum).Munit_Index := Multiple_Unit_Index;
656 Initialize_Scanner (Unum, Source_Index (Unum));
657 Discard_List (Par (Configuration_Pragmas => False));
658 Multiple_Unit_Index := Save_Index;
659 Set_Loading (Unum, False);
662 -- If spec is irrelevant, then post errors and quit
664 if Corr_Body /= No_Unit
665 and then Spec_Is_Irrelevant (Unum, Corr_Body)
667 Error_Msg_File_1 := Unit_File_Name (Corr_Body);
669 ("cannot compile subprogram in file {!", Load_Msg_Sloc);
670 Error_Msg_File_1 := Unit_File_Name (Unum);
672 ("\incorrect spec in file { must be removed first!",
677 -- If loaded unit had a fatal error, then caller inherits it!
679 if Units.Table (Unum).Fatal_Error
680 and then Present (Error_Node)
682 Units.Table (Calling_Unit).Fatal_Error := True;
685 -- Remove load stack entry and return the entry in the file table
687 Load_Stack.Decrement_Last;
690 -- Case of file not found
694 Write_Str (" file was not found, load failed");
698 -- Generate message if unit required
700 if Required and then Present (Error_Node) then
701 if Is_Predefined_File_Name (Fname) then
703 -- This is a predefined library unit which is not present
704 -- in the run time. If a predefined unit is not available
705 -- it may very likely be the case that there is also pragma
706 -- Restriction forbidding its usage. This is typically the
707 -- case when building a configurable run time, where the
708 -- usage of certain run-time units units is restricted by
709 -- means of both the corresponding pragma Restriction (such
710 -- as No_Calendar), and by not including the unit. Hence,
711 -- we check whether this predefined unit is forbidden, so
712 -- that the message about the restriction violation is
713 -- generated, if needed.
715 Check_Restricted_Unit (Load_Name, Error_Node);
717 Error_Msg_Unit_1 := Uname_Actual;
719 ("$$ is not a predefined library unit", Load_Msg_Sloc);
722 Error_Msg_File_1 := Fname;
723 Error_Msg ("file{ not found", Load_Msg_Sloc);
726 Write_Dependency_Chain;
728 -- Remove unit from stack, to avoid cascaded errors on
729 -- subsequent missing files.
731 Load_Stack.Decrement_Last;
732 Units.Decrement_Last;
734 -- If unit not required, remove load stack entry and the junk
735 -- file table entry, and return No_Unit to indicate not found,
738 Load_Stack.Decrement_Last;
739 Units.Decrement_Last;
747 ------------------------
748 -- Make_Instance_Unit --
749 ------------------------
751 -- If the unit is an instance, it appears as a package declaration, but
752 -- contains both declaration and body of the instance. The body becomes
753 -- the main unit of the compilation, and the declaration is inserted
754 -- at the end of the unit table. The main unit now has the name of a
755 -- body, which is constructed from the name of the original spec,
756 -- and is attached to the compilation node of the original unit. The
757 -- declaration has been attached to a new compilation unit node, and
758 -- code will have to be generated for it.
760 procedure Make_Instance_Unit (N : Node_Id) is
761 Sind : constant Source_File_Index := Source_Index (Main_Unit);
763 Units.Increment_Last;
764 Units.Table (Units.Last) := Units.Table (Main_Unit);
765 Units.Table (Units.Last).Cunit := Library_Unit (N);
766 Units.Table (Units.Last).Generate_Code := True;
767 Units.Table (Main_Unit).Cunit := N;
768 Units.Table (Main_Unit).Unit_Name :=
769 Get_Body_Name (Unit_Name (Get_Cunit_Unit_Number (Library_Unit (N))));
770 Units.Table (Main_Unit).Version := Source_Checksum (Sind);
771 end Make_Instance_Unit;
773 ------------------------
774 -- Spec_Is_Irrelevant --
775 ------------------------
777 function Spec_Is_Irrelevant
778 (Spec_Unit : Unit_Number_Type;
779 Body_Unit : Unit_Number_Type) return Boolean
781 Sunit : constant Node_Id := Cunit (Spec_Unit);
782 Bunit : constant Node_Id := Cunit (Body_Unit);
785 -- The spec is irrelevant if the body is a subprogram body, and the
786 -- spec is other than a subprogram spec or generic subprogram spec.
787 -- Note that the names must be the same, we don't need to check that,
788 -- because we already know that from the fact that the file names are
792 Nkind (Unit (Bunit)) = N_Subprogram_Body
793 and then Nkind (Unit (Sunit)) /= N_Subprogram_Declaration
794 and then Nkind (Unit (Sunit)) /= N_Generic_Subprogram_Declaration;
795 end Spec_Is_Irrelevant;
801 procedure Version_Update (U : Node_Id; From : Node_Id) is
802 Unum : constant Unit_Number_Type := Get_Cunit_Unit_Number (U);
803 Fnum : constant Unit_Number_Type := Get_Cunit_Unit_Number (From);
805 if Source_Index (Fnum) /= No_Source_File then
806 Units.Table (Unum).Version :=
807 Units.Table (Unum).Version
809 Source_Checksum (Source_Index (Fnum));
813 ----------------------------
814 -- Write_Dependency_Chain --
815 ----------------------------
817 procedure Write_Dependency_Chain is
819 -- The dependency chain is only written if it is at least two entries
820 -- deep, otherwise it is trivial (the main unit depending on a unit
821 -- that it obviously directly depends on).
823 if Load_Stack.Last - 1 > Load_Stack.First then
824 for U in Load_Stack.First .. Load_Stack.Last - 1 loop
826 Unit_Name (Load_Stack.Table (U).Unit_Number);
828 Unit_Name (Load_Stack.Table (U + 1).Unit_Number);
829 Error_Msg ("$ depends on $!", Load_Msg_Sloc);
832 end Write_Dependency_Chain;