1 ------------------------------------------------------------------------------
3 -- GNAT COMPILER COMPONENTS --
9 -- Copyright (C) 1997-2005 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 2, 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 COPYING. If not, write --
19 -- to the Free Software Foundation, 51 Franklin Street, Fifth Floor, --
20 -- Boston, MA 02110-1301, USA. --
22 -- GNAT was originally developed by the GNAT team at New York University. --
23 -- Extensive contributions were provided by Ada Core Technologies Inc. --
25 ------------------------------------------------------------------------------
27 with Atree; use Atree;
28 with Checks; use Checks;
29 with Debug; use Debug;
30 with Einfo; use Einfo;
31 with Elists; use Elists;
32 with Errout; use Errout;
33 with Exp_Tss; use Exp_Tss;
34 with Exp_Util; use Exp_Util;
35 with Expander; use Expander;
36 with Fname; use Fname;
38 with Lib.Load; use Lib.Load;
39 with Namet; use Namet;
40 with Nlists; use Nlists;
41 with Nmake; use Nmake;
43 with Output; use Output;
44 with Restrict; use Restrict;
45 with Rident; use Rident;
47 with Sem_Cat; use Sem_Cat;
48 with Sem_Ch7; use Sem_Ch7;
49 with Sem_Ch8; use Sem_Ch8;
50 with Sem_Res; use Sem_Res;
51 with Sem_Util; use Sem_Util;
52 with Sinfo; use Sinfo;
53 with Sinput; use Sinput;
54 with Snames; use Snames;
55 with Stand; use Stand;
57 with Tbuild; use Tbuild;
58 with Uname; use Uname;
60 package body Sem_Elab is
62 -- The following table records the recursive call chain for output
63 -- in the Output routine. Each entry records the call node and the
64 -- entity of the called routine. The number of entries in the table
65 -- (i.e. the value of Elab_Call.Last) indicates the current depth
66 -- of recursion and is used to identify the outer level.
68 type Elab_Call_Entry is record
73 package Elab_Call is new Table.Table (
74 Table_Component_Type => Elab_Call_Entry,
75 Table_Index_Type => Int,
78 Table_Increment => 100,
79 Table_Name => "Elab_Call");
81 -- This table is initialized at the start of each outer level call.
82 -- It holds the entities for all subprograms that have been examined
83 -- for this particular outer level call, and is used to prevent both
84 -- infinite recursion, and useless reanalysis of bodies already seen
86 package Elab_Visited is new Table.Table (
87 Table_Component_Type => Entity_Id,
88 Table_Index_Type => Int,
91 Table_Increment => 100,
92 Table_Name => "Elab_Visited");
94 -- This table stores calls to Check_Internal_Call that are delayed
95 -- until all generics are instantiated, and in particular that all
96 -- generic bodies have been inserted. We need to delay, because we
97 -- need to be able to look through the inserted bodies.
99 type Delay_Element is record
101 -- The parameter N from the call to Check_Internal_Call. Note that
102 -- this node may get rewritten over the delay period by expansion
103 -- in the call case (but not in the instantiation case).
106 -- The parameter E from the call to Check_Internal_Call
108 Orig_Ent : Entity_Id;
109 -- The parameter Orig_Ent from the call to Check_Internal_Call
112 -- The current scope of the call. This is restored when we complete
113 -- the delayed call, so that we do this in the right scope.
115 From_Elab_Code : Boolean;
116 -- Save indication of whether this call is from elaboration code
118 Outer_Scope : Entity_Id;
119 -- Save scope of outer level call
123 package Delay_Check is new Table.Table (
124 Table_Component_Type => Delay_Element,
125 Table_Index_Type => Int,
126 Table_Low_Bound => 1,
127 Table_Initial => 1000,
128 Table_Increment => 100,
129 Table_Name => "Delay_Check");
132 -- Top level scope of current scope. We need to compute this only
133 -- once at the outer level, i.e. for a call to Check_Elab_Call from
134 -- outside this unit.
136 Outer_Level_Sloc : Source_Ptr;
137 -- Save Sloc value for outer level call node for comparisons of source
138 -- locations. A body is too late if it appears after the *outer* level
139 -- call, not the particular call that is being analyzed.
141 From_Elab_Code : Boolean;
142 -- This flag shows whether the outer level call currently being examined
143 -- is or is not in elaboration code. We are only interested in calls to
144 -- routines in other units if this flag is True.
146 In_Task_Activation : Boolean := False;
147 -- This flag indicates whether we are performing elaboration checks on
148 -- task procedures, at the point of activation. If true, we do not trace
149 -- internal calls in these procedures, because all local bodies are known
152 Delaying_Elab_Checks : Boolean := True;
153 -- This is set True till the compilation is complete, including the
154 -- insertion of all instance bodies. Then when Check_Elab_Calls is
155 -- called, the delay table is used to make the delayed calls and
156 -- this flag is reset to False, so that the calls are processed
158 -----------------------
159 -- Local Subprograms --
160 -----------------------
162 -- Note: Outer_Scope in all following specs represents the scope of
163 -- interest of the outer level call. If it is set to Standard_Standard,
164 -- then it means the outer level call was at elaboration level, and that
165 -- thus all calls are of interest. If it was set to some other scope,
166 -- then the original call was an inner call, and we are not interested
167 -- in calls that go outside this scope.
169 procedure Check_A_Call
172 Outer_Scope : Entity_Id;
173 Inter_Unit_Only : Boolean;
174 Generate_Warnings : Boolean := True);
175 -- This is the internal recursive routine that is called to check for
176 -- a possible elaboration error. The argument N is a subprogram call
177 -- or generic instantiation to be checked, and E is the entity of
178 -- the called subprogram, or instantiated generic unit. The flag
179 -- Outer_Scope is the outer level scope for the original call.
180 -- Inter_Unit_Only is set if the call is only to be checked in the
181 -- case where it is to another unit (and skipped if within a unit).
182 -- Generate_Warnings is set to False to suppress warning messages
183 -- about missing pragma Elaborate_All's. These messages are not
184 -- wanted for inner calls in the dynamic model.
186 procedure Check_Bad_Instantiation (N : Node_Id);
187 -- N is a node for an instantiation (if called with any other node kind,
188 -- Check_Bad_Instantiation ignores the call). This subprogram checks for
189 -- the special case of a generic instantiation of a generic spec in the
190 -- same declarative part as the instantiation where a body is present and
191 -- has not yet been seen. This is an obvious error, but needs to be checked
192 -- specially at the time of the instantiation, since it is a case where we
193 -- cannot insert the body anywhere. If this case is detected, warnings are
194 -- generated, and a raise of Program_Error is inserted. In addition any
195 -- subprograms in the generic spec are stubbed, and the Bad_Instantiation
196 -- flag is set on the instantiation node. The caller in Sem_Ch12 uses this
197 -- flag as an indication that no attempt should be made to insert an
200 procedure Check_Internal_Call
203 Outer_Scope : Entity_Id;
204 Orig_Ent : Entity_Id);
205 -- N is a function call or procedure statement call node and E is
206 -- the entity of the called function, which is within the current
207 -- compilation unit (where subunits count as part of the parent).
208 -- This call checks if this call, or any call within any accessed
209 -- body could cause an ABE, and if so, outputs a warning. Orig_Ent
210 -- differs from E only in the case of renamings, and points to the
211 -- original name of the entity. This is used for error messages.
212 -- Outer_Scope is the outer level scope for the original call.
214 procedure Check_Internal_Call_Continue
217 Outer_Scope : Entity_Id;
218 Orig_Ent : Entity_Id);
219 -- The processing for Check_Internal_Call is divided up into two phases,
220 -- and this represents the second phase. The second phase is delayed if
221 -- Delaying_Elab_Calls is set to True. In this delayed case, the first
222 -- phase makes an entry in the Delay_Check table, which is processed
223 -- when Check_Elab_Calls is called. N, E and Orig_Ent are as for the call
224 -- to Check_Internal_Call. Outer_Scope is the outer level scope for
225 -- the original call.
227 procedure Set_Elaboration_Constraint
231 -- The current unit U may depend semantically on some unit P which is not
232 -- in the current context. If there is an elaboration call that reaches P,
233 -- we need to indicate that P requires an Elaborate_All, but this is not
234 -- effective in U's ali file, if there is no with_clause for P. In this
235 -- case we add the Elaborate_All on the unit Q that directly or indirectly
236 -- makes P available. This can happen in two cases:
238 -- a) Q declares a subtype of a type declared in P, and the call is an
239 -- initialization call for an object of that subtype.
241 -- b) Q declares an object of some tagged type whose root type is
242 -- declared in P, and the initialization call uses object notation on
243 -- that object to reach a primitive operation or a classwide operation
246 -- If P appears in the context of U, the current processing is correct.
247 -- Otherwise we must identify these two cases to retrieve Q and place the
248 -- Elaborate_All_Desirable on it.
250 function Has_Generic_Body (N : Node_Id) return Boolean;
251 -- N is a generic package instantiation node, and this routine determines
252 -- if this package spec does in fact have a generic body. If so, then
253 -- True is returned, otherwise False. Note that this is not at all the
254 -- same as checking if the unit requires a body, since it deals with
255 -- the case of optional bodies accurately (i.e. if a body is optional,
256 -- then it looks to see if a body is actually present). Note: this
257 -- function can only do a fully correct job if in generating code mode
258 -- where all bodies have to be present. If we are operating in semantics
259 -- check only mode, then in some cases of optional bodies, a result of
260 -- False may incorrectly be given. In practice this simply means that
261 -- some cases of warnings for incorrect order of elaboration will only
262 -- be given when generating code, which is not a big problem (and is
263 -- inevitable, given the optional body semantics of Ada).
265 procedure Insert_Elab_Check (N : Node_Id; C : Node_Id := Empty);
266 -- Given code for an elaboration check (or unconditional raise if
267 -- the check is not needed), inserts the code in the appropriate
268 -- place. N is the call or instantiation node for which the check
269 -- code is required. C is the test whose failure triggers the raise.
271 procedure Output_Calls (N : Node_Id);
272 -- Outputs chain of calls stored in the Elab_Call table. The caller
273 -- has already generated the main warning message, so the warnings
274 -- generated are all continuation messages. The argument is the
275 -- call node at which the messages are to be placed.
277 function Same_Elaboration_Scope (Scop1, Scop2 : Entity_Id) return Boolean;
278 -- Given two scopes, determine whether they are the same scope from an
279 -- elaboration point of view, i.e. packages and blocks are ignored.
281 procedure Set_C_Scope;
282 -- On entry C_Scope is set to some scope. On return, C_Scope is reset
283 -- to be the enclosing compilation unit of this scope.
285 function Spec_Entity (E : Entity_Id) return Entity_Id;
286 -- Given a compilation unit entity, if it is a spec entity, it is
287 -- returned unchanged. If it is a body entity, then the spec for
288 -- the corresponding spec is returned
290 procedure Supply_Bodies (N : Node_Id);
291 -- Given a node, N, that is either a subprogram declaration or a package
292 -- declaration, this procedure supplies dummy bodies for the subprogram
293 -- or for all subprograms in the package. If the given node is not one
294 -- of these two possibilities, then Supply_Bodies does nothing. The
295 -- dummy body is supplied by setting the subprogram to be Imported with
296 -- convention Stubbed.
298 procedure Supply_Bodies (L : List_Id);
299 -- Calls Supply_Bodies for all elements of the given list L.
301 function Within (E1, E2 : Entity_Id) return Boolean;
302 -- Given two scopes E1 and E2, returns True if E1 is equal to E2, or
303 -- is one of its contained scopes, False otherwise.
305 function Within_Elaborate_All (E : Entity_Id) return Boolean;
306 -- Before emitting a warning on a scope E for a missing elaborate_all,
307 -- check whether E may be in the context of a directly visible unit
308 -- U to which the pragma applies. This prevents spurious warnings when
309 -- the called entity is renamed within U.
315 procedure Check_A_Call
318 Outer_Scope : Entity_Id;
319 Inter_Unit_Only : Boolean;
320 Generate_Warnings : Boolean := True)
322 Loc : constant Source_Ptr := Sloc (N);
327 -- Top level scope of entity for called subprogram. This
328 -- value includes following renamings and derivations, so
329 -- this scope can be in a non-visible unit. This is the
330 -- scope that is to be investigated to see whether an
331 -- elaboration check is required.
334 -- Top level scope of directly called entity for subprogram. This
335 -- differs from E_Scope in the case where renamings or derivations
336 -- are involved, since it does not follow these links. W_Scope is
337 -- generally in a visible unit, and it is this scope that may require
338 -- an Elaborate_All. However, there are some cases (initialization
339 -- calls and calls involving object notation) where W_Scope might not
340 -- be in the context of the current unit, and there is an intermediate
341 -- package that is, in which case the Elaborate_All has to be placed
342 -- on this intedermediate package. These special cases are handled in
343 -- Set_Elaboration_Constraint.
345 Body_Acts_As_Spec : Boolean;
346 -- Set to true if call is to body acting as spec (no separate spec)
348 Inst_Case : constant Boolean := Nkind (N) in N_Generic_Instantiation;
349 -- Indicates if we have instantiation case
351 Caller_Unit_Internal : Boolean;
352 Callee_Unit_Internal : Boolean;
354 Inst_Caller : Source_Ptr;
355 Inst_Callee : Source_Ptr;
357 Unit_Caller : Unit_Number_Type;
358 Unit_Callee : Unit_Number_Type;
360 Cunit_SC : Boolean := False;
361 -- Set to suppress dynamic elaboration checks where one of the
362 -- enclosing scopes has Elaboration_Checks_Suppressed set, or else
363 -- if a pragma Elaborate (_All) applies to that scope, in which case
364 -- warnings on the scope are also suppressed. For the internal case,
365 -- we ignore this flag.
368 -- If the call is known to be within a local Suppress Elaboration
369 -- pragma, nothing to check. This can happen in task bodies.
371 if (Nkind (N) = N_Function_Call
372 or else Nkind (N) = N_Procedure_Call_Statement)
373 and then No_Elaboration_Check (N)
378 -- Go to parent for derived subprogram, or to original subprogram
379 -- in the case of a renaming (Alias covers both these cases)
383 if (Suppress_Elaboration_Warnings (Ent)
384 or else Elaboration_Checks_Suppressed (Ent))
385 and then (Inst_Case or else No (Alias (Ent)))
390 -- Nothing to do for imported entities
392 if Is_Imported (Ent) then
396 exit when Inst_Case or else No (Alias (Ent));
400 Decl := Unit_Declaration_Node (Ent);
402 if Nkind (Decl) = N_Subprogram_Body then
403 Body_Acts_As_Spec := True;
405 elsif Nkind (Decl) = N_Subprogram_Declaration
406 or else Nkind (Decl) = N_Subprogram_Body_Stub
409 Body_Acts_As_Spec := False;
411 -- If we have none of an instantiation, subprogram body or
412 -- subprogram declaration, then it is not a case that we want
413 -- to check. (One case is a call to a generic formal subprogram,
414 -- where we do not want the check in the template).
422 if Elaboration_Checks_Suppressed (E_Scope)
423 or else Suppress_Elaboration_Warnings (E_Scope)
428 -- Exit when we get to compilation unit, not counting subunits
430 exit when Is_Compilation_Unit (E_Scope)
431 and then (Is_Child_Unit (E_Scope)
432 or else Scope (E_Scope) = Standard_Standard);
434 -- If we did not find a compilation unit, other than standard,
435 -- then nothing to check (happens in some instantiation cases)
437 if E_Scope = Standard_Standard then
440 -- Otherwise move up a scope looking for compilation unit
443 E_Scope := Scope (E_Scope);
447 -- No checks needed for pure or preelaborated compilation units
450 or else Is_Preelaborated (E_Scope)
455 -- If the generic entity is within a deeper instance than we are, then
456 -- either the instantiation to which we refer itself caused an ABE, in
457 -- which case that will be handled separately, or else we know that the
458 -- body we need appears as needed at the point of the instantiation.
459 -- However, this assumption is only valid if we are in static mode.
461 if not Dynamic_Elaboration_Checks
462 and then Instantiation_Depth (Sloc (Ent)) >
463 Instantiation_Depth (Sloc (N))
468 -- Do not give a warning for a package with no body
470 if Ekind (Ent) = E_Generic_Package
471 and then not Has_Generic_Body (N)
476 -- Case of entity is not in current unit (i.e. with'ed unit case)
478 if E_Scope /= C_Scope then
480 -- We are only interested in such calls if the outer call was from
481 -- elaboration code, or if we are in Dynamic_Elaboration_Checks mode.
483 if not From_Elab_Code and then not Dynamic_Elaboration_Checks then
487 -- Nothing to do if some scope said that no checks were required
493 -- Nothing to do for a generic instance, because in this case
494 -- the checking was at the point of instantiation of the generic
495 -- However, this shortcut is only applicable in static mode.
497 if Is_Generic_Instance (Ent) and not Dynamic_Elaboration_Checks then
501 -- Nothing to do if subprogram with no separate spec. However,
502 -- a call to Deep_Initialize may result in a call to a user-defined
503 -- Initialize procedure, which imposes a body dependency. This
504 -- happens only if the type is controlled and the Initialize
505 -- procedure is not inherited.
507 if Body_Acts_As_Spec then
508 if Is_TSS (Ent, TSS_Deep_Initialize) then
513 Typ := Etype (Next_Formal (First_Formal (Ent)));
515 if not Is_Controlled (Typ) then
518 Init := Find_Prim_Op (Typ, Name_Initialize);
520 if Comes_From_Source (Init) then
533 -- Check cases of internal units
535 Callee_Unit_Internal :=
536 Is_Internal_File_Name
537 (Unit_File_Name (Get_Source_Unit (E_Scope)));
539 -- Do not give a warning if the with'ed unit is internal
540 -- and this is the generic instantiation case (this saves a
541 -- lot of hassle dealing with the Text_IO special child units)
543 if Callee_Unit_Internal and Inst_Case then
547 if C_Scope = Standard_Standard then
548 Caller_Unit_Internal := False;
550 Caller_Unit_Internal :=
551 Is_Internal_File_Name
552 (Unit_File_Name (Get_Source_Unit (C_Scope)));
555 -- Do not give a warning if the with'ed unit is internal
556 -- and the caller is not internal (since the binder always
557 -- elaborates internal units first).
559 if Callee_Unit_Internal and (not Caller_Unit_Internal) then
563 -- For now, if debug flag -gnatdE is not set, do no checking for
564 -- one internal unit withing another. This fixes the problem with
565 -- the sgi build and storage errors. To be resolved later ???
567 if (Callee_Unit_Internal and Caller_Unit_Internal)
568 and then not Debug_Flag_EE
573 if Is_TSS (E, TSS_Deep_Initialize) then
577 -- If the call is in an instance, and the called entity is not
578 -- defined in the same instance, then the elaboration issue
579 -- focuses around the unit containing the template, it is
580 -- this unit which requires an Elaborate_All.
582 -- However, if we are doing dynamic elaboration, we need to
583 -- chase the call in the usual manner.
585 -- We do not handle the case of calling a generic formal correctly
586 -- in the static case. See test 4703-004 to explore this gap ???
588 Inst_Caller := Instantiation (Get_Source_File_Index (Sloc (N)));
589 Inst_Callee := Instantiation (Get_Source_File_Index (Sloc (Ent)));
591 if Inst_Caller = No_Location then
592 Unit_Caller := No_Unit;
594 Unit_Caller := Get_Source_Unit (N);
597 if Inst_Callee = No_Location then
598 Unit_Callee := No_Unit;
600 Unit_Callee := Get_Source_Unit (Ent);
603 if Unit_Caller /= No_Unit
604 and then Unit_Callee /= Unit_Caller
605 and then not Dynamic_Elaboration_Checks
607 E_Scope := Spec_Entity (Cunit_Entity (Unit_Caller));
609 -- If we don't get a spec entity, just ignore call. Not
610 -- quite clear why this check is necessary.
616 -- Otherwise step to enclosing compilation unit
618 while not Is_Compilation_Unit (E_Scope) loop
619 E_Scope := Scope (E_Scope);
622 -- For the case N is not an instance, or a call within instance
623 -- We recompute E_Scope for the error message, since we
624 -- do NOT want to go to the unit which has the ultimate
625 -- declaration in the case of renaming and derivation and
626 -- we also want to go to the generic unit in the case of
627 -- an instance, and no further.
630 -- Loop to carefully follow renamings and derivations
631 -- one step outside the current unit, but not further.
634 and then Present (Alias (Ent))
636 E_Scope := Alias (Ent);
642 while not Is_Compilation_Unit (E_Scope) loop
643 E_Scope := Scope (E_Scope);
646 -- If E_Scope is the same as C_Scope, it means that there
647 -- definitely was a local renaming or derivation, and we
648 -- are not yet out of the current unit.
650 exit when E_Scope /= C_Scope;
654 -- If no alias, there is a previous error
662 if Within_Elaborate_All (E_Scope) then
666 -- Find top level scope for called entity (not following renamings
667 -- or derivations). This is where the Elaborate_All will go if it
668 -- is needed. We start with the called entity, except in the case
669 -- of an initialization procedure outside the current package, where
670 -- the init proc is in the root package, and we start from the entity
671 -- of the name in the call.
673 if Is_Entity_Name (Name (N))
674 and then Is_Init_Proc (Entity (Name (N)))
675 and then not In_Same_Extended_Unit (N, Entity (Name (N)))
677 W_Scope := Scope (Entity (Name (N)));
682 while not Is_Compilation_Unit (W_Scope) loop
683 W_Scope := Scope (W_Scope);
686 -- Now check if an elaborate_all (or dynamic check) is needed
688 if not Suppress_Elaboration_Warnings (Ent)
689 and then not Elaboration_Checks_Suppressed (Ent)
690 and then not Suppress_Elaboration_Warnings (E_Scope)
691 and then not Elaboration_Checks_Suppressed (E_Scope)
692 and then Elab_Warnings
693 and then Generate_Warnings
697 ("instantiation of& may raise Program_Error?", N, Ent);
700 if Is_Init_Proc (Entity (Name (N)))
701 and then Comes_From_Source (Ent)
704 ("implicit call to & may raise Program_Error?", N, Ent);
708 ("call to & may raise Program_Error?", N, Ent);
712 Error_Msg_Qual_Level := Nat'Last;
714 ("\missing pragma Elaborate_All for&?", N, W_Scope);
715 Error_Msg_Qual_Level := 0;
718 -- Set flag to prevent further warnings for same unit
719 -- unless in All_Errors_Mode.
721 if not All_Errors_Mode and not Dynamic_Elaboration_Checks then
722 Set_Suppress_Elaboration_Warnings (W_Scope, True);
726 -- Check for runtime elaboration check required
728 if Dynamic_Elaboration_Checks then
729 if not Elaboration_Checks_Suppressed (Ent)
730 and then not Elaboration_Checks_Suppressed (W_Scope)
731 and then not Elaboration_Checks_Suppressed (E_Scope)
732 and then not Cunit_SC
734 -- Runtime elaboration check required. Generate check of the
735 -- elaboration Boolean for the unit containing the entity.
737 -- Note that for this case, we do check the real unit (the
738 -- one from following renamings, since that is the issue!)
740 -- Could this possibly miss a useless but required PE???
742 Insert_Elab_Check (N,
743 Make_Attribute_Reference (Loc,
744 Attribute_Name => Name_Elaborated,
747 (Spec_Entity (E_Scope), Loc)));
750 -- Case of static elaboration model
753 -- Do not do anything if elaboration checks suppressed. Note
754 -- that we check Ent here, not E, since we want the real entity
755 -- for the body to see if checks are suppressed for it, not the
756 -- dummy entry for renamings or derivations.
758 if Elaboration_Checks_Suppressed (Ent)
759 or else Elaboration_Checks_Suppressed (E_Scope)
760 or else Elaboration_Checks_Suppressed (W_Scope)
764 -- Here we need to generate an implicit elaborate all
767 -- Generate elaborate_all warning unless suppressed
769 if (Elab_Warnings and Generate_Warnings and not Inst_Case)
770 and then not Suppress_Elaboration_Warnings (Ent)
771 and then not Suppress_Elaboration_Warnings (E_Scope)
772 and then not Suppress_Elaboration_Warnings (W_Scope)
774 Error_Msg_Node_2 := W_Scope;
776 ("call to& in elaboration code " &
777 "requires pragma Elaborate_All on&?", N, E);
780 -- Set indication for binder to generate Elaborate_All
782 Set_Elaboration_Constraint (N, E, W_Scope);
786 -- Case of entity is in same unit as call or instantiation
788 elsif not Inter_Unit_Only then
789 Check_Internal_Call (N, Ent, Outer_Scope, E);
793 -----------------------------
794 -- Check_Bad_Instantiation --
795 -----------------------------
797 procedure Check_Bad_Instantiation (N : Node_Id) is
801 -- Nothing to do if we do not have an instantiation (happens in some
802 -- error cases, and also in the formal package declaration case)
804 if Nkind (N) not in N_Generic_Instantiation then
807 -- Nothing to do if serious errors detected (avoid cascaded errors)
809 elsif Serious_Errors_Detected /= 0 then
812 -- Nothing to do if not in full analysis mode
814 elsif not Full_Analysis then
817 -- Nothing to do if inside a generic template
819 elsif Inside_A_Generic then
822 -- Nothing to do if a library level instantiation
824 elsif Nkind (Parent (N)) = N_Compilation_Unit then
827 -- Nothing to do if we are compiling a proper body for semantic
828 -- purposes only. The generic body may be in another proper body.
831 Nkind (Parent (Unit_Declaration_Node (Main_Unit_Entity))) = N_Subunit
836 Ent := Get_Generic_Entity (N);
838 -- The case we are interested in is when the generic spec is in the
839 -- current declarative part
841 if not Same_Elaboration_Scope (Current_Scope, Scope (Ent))
842 or else not In_Same_Extended_Unit (N, Ent)
847 -- If the generic entity is within a deeper instance than we are, then
848 -- either the instantiation to which we refer itself caused an ABE, in
849 -- which case that will be handled separately. Otherwise, we know that
850 -- the body we need appears as needed at the point of the instantiation.
851 -- If they are both at the same level but not within the same instance
852 -- then the body of the generic will be in the earlier instance.
855 D1 : constant Int := Instantiation_Depth (Sloc (Ent));
856 D2 : constant Int := Instantiation_Depth (Sloc (N));
863 and then Is_Generic_Instance (Scope (Ent))
864 and then not In_Open_Scopes (Scope (Ent))
870 -- Now we can proceed, if the entity being called has a completion,
871 -- then we are definitely OK, since we have already seen the body.
873 if Has_Completion (Ent) then
877 -- If there is no body, then nothing to do
879 if not Has_Generic_Body (N) then
883 -- Here we definitely have a bad instantiation
886 ("?cannot instantiate& before body seen", N, Ent);
888 if Present (Instance_Spec (N)) then
889 Supply_Bodies (Instance_Spec (N));
893 ("\?Program_Error will be raised at run time", N);
894 Insert_Elab_Check (N);
895 Set_ABE_Is_Certain (N);
897 end Check_Bad_Instantiation;
899 ---------------------
900 -- Check_Elab_Call --
901 ---------------------
903 procedure Check_Elab_Call
905 Outer_Scope : Entity_Id := Empty)
910 function Get_Called_Ent return Entity_Id;
911 -- Retrieve called entity. If this is a call to a protected subprogram,
912 -- entity is a selected component. The callable entity may be absent,
913 -- in which case there is no check to perform. This happens with
914 -- non-analyzed calls in nested generics.
920 function Get_Called_Ent return Entity_Id is
929 elsif Nkind (Nam) = N_Selected_Component then
930 return Entity (Selector_Name (Nam));
932 elsif not Is_Entity_Name (Nam) then
940 -- Start of processing for Check_Elab_Call
943 -- If the call does not come from the main unit, there is nothing to
944 -- check. Elaboration call from units in the context of the main unit
945 -- will lead to semantic dependencies when those units are compiled.
947 if not In_Extended_Main_Code_Unit (N) then
951 -- For an entry call, check relevant restriction
953 if Nkind (N) = N_Entry_Call_Statement
954 and then not In_Subprogram_Or_Concurrent_Unit
956 Check_Restriction (No_Entry_Calls_In_Elaboration_Code, N);
958 -- Nothing to do if this is not a call (happens in some error
959 -- conditions, and in some cases where rewriting occurs).
961 elsif Nkind (N) /= N_Function_Call
962 and then Nkind (N) /= N_Procedure_Call_Statement
966 -- Nothing to do if this is a call already rewritten for elab checking.
968 elsif Nkind (Parent (N)) = N_Conditional_Expression then
971 -- Nothing to do if inside a generic template
973 elsif Inside_A_Generic
974 and then not Present (Enclosing_Generic_Body (N))
979 -- Here we have a call at elaboration time which must be checked
981 if Debug_Flag_LL then
982 Write_Str (" Check_Elab_Call: ");
985 or else not Is_Entity_Name (Name (N))
987 Write_Str ("<<not entity name>> ");
989 Write_Name (Chars (Entity (Name (N))));
992 Write_Str (" call at ");
993 Write_Location (Sloc (N));
997 -- Climb up the tree to make sure we are not inside a
998 -- default expression of a parameter specification or
999 -- a record component, since in both these cases, we
1000 -- will be doing the actual call later, not now, and it
1001 -- is at the time of the actual call (statically speaking)
1002 -- that we must do our static check, not at the time of
1003 -- its initial analysis). However, we have to check calls
1004 -- within component definitions (e.g., a function call
1005 -- that determines an array component bound), so we
1006 -- terminate the loop in that case.
1009 while Present (P) loop
1010 if Nkind (P) = N_Parameter_Specification
1012 Nkind (P) = N_Component_Declaration
1016 -- The call occurs within the constraint of a component,
1017 -- so it must be checked.
1019 elsif Nkind (P) = N_Component_Definition then
1027 -- Stuff that happens only at the outer level
1029 if No (Outer_Scope) then
1030 Elab_Visited.Set_Last (0);
1032 -- Nothing to do if current scope is Standard (this is a bit
1033 -- odd, but it happens in the case of generic instantiations).
1035 C_Scope := Current_Scope;
1037 if C_Scope = Standard_Standard then
1041 -- First case, we are in elaboration code
1043 From_Elab_Code := not In_Subprogram_Or_Concurrent_Unit;
1044 if From_Elab_Code then
1046 -- Complain if call that comes from source in preelaborated
1047 -- unit and we are not inside a subprogram (i.e. we are in
1050 if Comes_From_Source (N)
1051 and then In_Preelaborated_Unit
1052 and then not In_Inlined_Body
1054 -- This is a warning in -gnatg mode allowing such calls to
1055 -- be used in the predefined library with appropriate care.
1059 ("?non-static call not allowed in preelaborated unit", N);
1062 ("non-static call not allowed in preelaborated unit", N);
1068 -- Second case, we are inside a subprogram or concurrent unit
1069 -- i.e, we are not in elaboration code.
1072 -- In this case, the issue is whether we are inside the
1073 -- declarative part of the unit in which we live, or inside
1074 -- its statements. In the latter case, there is no issue of
1075 -- ABE calls at this level (a call from outside to the unit
1076 -- in which we live might cause an ABE, but that will be
1077 -- detected when we analyze that outer level call, as it
1078 -- recurses into the called unit).
1080 -- Climb up the tree, doing this test, and also testing
1081 -- for being inside a default expression, which, as
1082 -- discussed above, is not checked at this stage.
1091 -- If we find a parentless subtree, it seems safe to
1092 -- assume that we are not in a declarative part and
1093 -- that no checking is required.
1099 if Is_List_Member (P) then
1100 L := List_Containing (P);
1107 exit when Nkind (P) = N_Subunit;
1109 -- Filter out case of default expressions, where
1110 -- we do not do the check at this stage.
1112 if Nkind (P) = N_Parameter_Specification
1114 Nkind (P) = N_Component_Declaration
1119 if Nkind (P) = N_Subprogram_Body
1121 Nkind (P) = N_Protected_Body
1123 Nkind (P) = N_Task_Body
1125 Nkind (P) = N_Block_Statement
1127 if L = Declarations (P) then
1130 -- We are not in elaboration code, but we are doing
1131 -- dynamic elaboration checks, in this case, we still
1132 -- need to do the call, since the subprogram we are in
1133 -- could be called from another unit, also in dynamic
1134 -- elaboration check mode, at elaboration time.
1136 elsif Dynamic_Elaboration_Checks then
1138 -- This is a rather new check, going into version
1139 -- 3.14a1 for the first time (V1.80 of this unit),
1140 -- so we provide a debug flag to enable it. That
1141 -- way we have an easy work around for regressions
1142 -- that are caused by this new check. This debug
1143 -- flag can be removed later.
1145 if Debug_Flag_DD then
1149 -- Do the check in this case
1153 elsif Nkind (P) = N_Task_Body then
1155 -- The check is deferred until Check_Task_Activation
1156 -- but we need to capture local suppress pragmas
1157 -- that may inhibit checks on this call.
1159 Ent := Get_Called_Ent;
1164 elsif Elaboration_Checks_Suppressed (Current_Scope)
1165 or else Elaboration_Checks_Suppressed (Ent)
1166 or else Elaboration_Checks_Suppressed (Scope (Ent))
1168 Set_No_Elaboration_Check (N);
1173 -- Static model, call is not in elaboration code, we
1174 -- never need to worry, because in the static model
1175 -- the top level caller always takes care of things.
1186 Ent := Get_Called_Ent;
1192 -- Nothing to do if this is a recursive call (i.e. a call to
1193 -- an entity that is already in the Elab_Call stack)
1195 for J in 1 .. Elab_Visited.Last loop
1196 if Ent = Elab_Visited.Table (J) then
1201 -- See if we need to analyze this call. We analyze it if either of
1202 -- the following conditions is met:
1204 -- It is an inner level call (since in this case it was triggered
1205 -- by an outer level call from elaboration code), but only if the
1206 -- call is within the scope of the original outer level call.
1208 -- It is an outer level call from elaboration code, or the called
1209 -- entity is in the same elaboration scope.
1211 -- And in these cases, we will check both inter-unit calls and
1212 -- intra-unit (within a single unit) calls.
1214 C_Scope := Current_Scope;
1216 -- If not outer level call, then we follow it if it is within
1217 -- the original scope of the outer call.
1219 if Present (Outer_Scope)
1220 and then Within (Scope (Ent), Outer_Scope)
1223 Check_A_Call (N, Ent, Outer_Scope, Inter_Unit_Only => False);
1225 elsif Elaboration_Checks_Suppressed (Current_Scope) then
1228 elsif From_Elab_Code then
1230 Check_A_Call (N, Ent, Standard_Standard, Inter_Unit_Only => False);
1232 elsif Same_Elaboration_Scope (C_Scope, Scope (Ent)) then
1234 Check_A_Call (N, Ent, Scope (Ent), Inter_Unit_Only => False);
1236 -- If none of those cases holds, but Dynamic_Elaboration_Checks mode
1237 -- is set, then we will do the check, but only in the inter-unit case
1238 -- (this is to accommodate unguarded elaboration calls from other units
1239 -- in which this same mode is set). We don't want warnings in this case,
1240 -- it would generate warnings having nothing to do with elaboration.
1242 elsif Dynamic_Elaboration_Checks then
1248 Inter_Unit_Only => True,
1249 Generate_Warnings => False);
1251 -- Otherwise nothing to do
1257 -- A call to an Init_Proc in elaboration code may bring additional
1258 -- dependencies, if some of the record components thereof have
1259 -- initializations that are function calls that come from source.
1260 -- We treat the current node as a call to each of these functions,
1261 -- to check their elaboration impact.
1263 if Is_Init_Proc (Ent)
1264 and then From_Elab_Code
1266 Process_Init_Proc : declare
1267 Unit_Decl : constant Node_Id := Unit_Declaration_Node (Ent);
1269 function Process (Nod : Node_Id) return Traverse_Result;
1270 -- Find subprogram calls within body of init_proc for
1271 -- Traverse instantiation below.
1273 function Process (Nod : Node_Id) return Traverse_Result is
1277 if (Nkind (Nod) = N_Function_Call
1278 or else Nkind (Nod) = N_Procedure_Call_Statement)
1279 and then Is_Entity_Name (Name (Nod))
1281 Func := Entity (Name (Nod));
1283 if Comes_From_Source (Func) then
1285 (N, Func, Standard_Standard, Inter_Unit_Only => True);
1295 procedure Traverse_Body is new Traverse_Proc (Process);
1297 -- Start of processing for Process_Init_Proc
1300 if Nkind (Unit_Decl) = N_Subprogram_Body then
1301 Traverse_Body (Handled_Statement_Sequence (Unit_Decl));
1303 end Process_Init_Proc;
1305 end Check_Elab_Call;
1307 ----------------------
1308 -- Check_Elab_Calls --
1309 ----------------------
1311 procedure Check_Elab_Calls is
1313 -- If expansion is disabled, do not generate any checks. Also
1314 -- skip checks if any subunits are missing because in either
1315 -- case we lack the full information that we need, and no object
1316 -- file will be created in any case.
1318 if not Expander_Active
1319 or else Is_Generic_Unit (Cunit_Entity (Main_Unit))
1320 or else Subunits_Missing
1325 -- Skip delayed calls if we had any errors
1327 if Serious_Errors_Detected = 0 then
1328 Delaying_Elab_Checks := False;
1329 Expander_Mode_Save_And_Set (True);
1331 for J in Delay_Check.First .. Delay_Check.Last loop
1332 New_Scope (Delay_Check.Table (J).Curscop);
1333 From_Elab_Code := Delay_Check.Table (J).From_Elab_Code;
1335 Check_Internal_Call_Continue (
1336 N => Delay_Check.Table (J).N,
1337 E => Delay_Check.Table (J).E,
1338 Outer_Scope => Delay_Check.Table (J).Outer_Scope,
1339 Orig_Ent => Delay_Check.Table (J).Orig_Ent);
1344 -- Set Delaying_Elab_Checks back on for next main compilation
1346 Expander_Mode_Restore;
1347 Delaying_Elab_Checks := True;
1349 end Check_Elab_Calls;
1351 ------------------------------
1352 -- Check_Elab_Instantiation --
1353 ------------------------------
1355 procedure Check_Elab_Instantiation
1357 Outer_Scope : Entity_Id := Empty)
1362 -- Check for and deal with bad instantiation case. There is some
1363 -- duplicated code here, but we will worry about this later ???
1365 Check_Bad_Instantiation (N);
1367 if ABE_Is_Certain (N) then
1371 -- Nothing to do if we do not have an instantiation (happens in some
1372 -- error cases, and also in the formal package declaration case)
1374 if Nkind (N) not in N_Generic_Instantiation then
1378 -- Nothing to do if inside a generic template
1380 if Inside_A_Generic then
1384 -- Nothing to do if the instantiation is not in the main unit.
1386 if not In_Extended_Main_Code_Unit (N) then
1390 Ent := Get_Generic_Entity (N);
1391 From_Elab_Code := not In_Subprogram_Or_Concurrent_Unit;
1393 -- See if we need to analyze this instantiation. We analyze it if
1394 -- either of the following conditions is met:
1396 -- It is an inner level instantiation (since in this case it was
1397 -- triggered by an outer level call from elaboration code), but
1398 -- only if the instantiation is within the scope of the original
1399 -- outer level call.
1401 -- It is an outer level instantiation from elaboration code, or the
1402 -- instantiated entity is in the same elaboratoin scope.
1404 -- And in these cases, we will check both the inter-unit case and
1405 -- the intra-unit (within a single unit) case.
1407 C_Scope := Current_Scope;
1409 if Present (Outer_Scope)
1410 and then Within (Scope (Ent), Outer_Scope)
1413 Check_A_Call (N, Ent, Outer_Scope, Inter_Unit_Only => False);
1415 elsif From_Elab_Code then
1417 Check_A_Call (N, Ent, Standard_Standard, Inter_Unit_Only => False);
1419 elsif Same_Elaboration_Scope (C_Scope, Scope (Ent)) then
1421 Check_A_Call (N, Ent, Scope (Ent), Inter_Unit_Only => False);
1423 -- If none of those cases holds, but Dynamic_Elaboration_Checks mode
1424 -- is set, then we will do the check, but only in the inter-unit case
1425 -- (this is to accommodate unguarded elaboration calls from other units
1426 -- in which this same mode is set). We inhibit warnings in this case,
1427 -- since this instantiation is not occurring in elaboration code.
1429 elsif Dynamic_Elaboration_Checks then
1435 Inter_Unit_Only => True,
1436 Generate_Warnings => False);
1441 end Check_Elab_Instantiation;
1443 -------------------------
1444 -- Check_Internal_Call --
1445 -------------------------
1447 procedure Check_Internal_Call
1450 Outer_Scope : Entity_Id;
1451 Orig_Ent : Entity_Id)
1453 Inst_Case : constant Boolean := Nkind (N) in N_Generic_Instantiation;
1456 -- If not function or procedure call or instantiation, then ignore
1457 -- call (this happens in some error case and rewriting cases)
1459 if Nkind (N) /= N_Function_Call
1461 Nkind (N) /= N_Procedure_Call_Statement
1467 -- Nothing to do if this is a call or instantiation that has
1468 -- already been found to be a sure ABE
1470 elsif ABE_Is_Certain (N) then
1473 -- Nothing to do if errors already detected (avoid cascaded errors)
1475 elsif Serious_Errors_Detected /= 0 then
1478 -- Nothing to do if not in full analysis mode
1480 elsif not Full_Analysis then
1483 -- Nothing to do if within a default expression, since the call
1484 -- is not actualy being made at this time.
1486 elsif In_Default_Expression then
1489 -- Nothing to do for call to intrinsic subprogram
1491 elsif Is_Intrinsic_Subprogram (E) then
1494 -- No need to trace local calls if checking task activation, because
1495 -- other local bodies are elaborated already.
1497 elsif In_Task_Activation then
1501 -- Delay this call if we are still delaying calls
1503 if Delaying_Elab_Checks then
1504 Delay_Check.Increment_Last;
1505 Delay_Check.Table (Delay_Check.Last) :=
1508 Orig_Ent => Orig_Ent,
1509 Curscop => Current_Scope,
1510 Outer_Scope => Outer_Scope,
1511 From_Elab_Code => From_Elab_Code);
1514 -- Otherwise, call phase 2 continuation right now
1517 Check_Internal_Call_Continue (N, E, Outer_Scope, Orig_Ent);
1520 end Check_Internal_Call;
1522 ----------------------------------
1523 -- Check_Internal_Call_Continue --
1524 ----------------------------------
1526 procedure Check_Internal_Call_Continue
1529 Outer_Scope : Entity_Id;
1530 Orig_Ent : Entity_Id)
1532 Loc : constant Source_Ptr := Sloc (N);
1533 Inst_Case : constant Boolean := Is_Generic_Unit (E);
1538 function Process (N : Node_Id) return Traverse_Result;
1539 -- Function applied to each node as we traverse the body.
1540 -- Checks for call that needs checking, and if so checks
1541 -- it. Always returns OK, so entire tree is traversed.
1547 function Process (N : Node_Id) return Traverse_Result is
1549 -- If user has specified that there are no entry calls in elaboration
1550 -- code, do not trace past an accept statement, because the rendez-
1551 -- vous will happen after elaboration.
1553 if (Nkind (Original_Node (N)) = N_Accept_Statement
1554 or else Nkind (Original_Node (N)) = N_Selective_Accept)
1555 and then Restriction_Active (No_Entry_Calls_In_Elaboration_Code)
1559 -- If we have a subprogram call, check it
1561 elsif Nkind (N) = N_Function_Call
1562 or else Nkind (N) = N_Procedure_Call_Statement
1564 Check_Elab_Call (N, Outer_Scope);
1567 -- If we have a generic instantiation, check it
1569 elsif Nkind (N) in N_Generic_Instantiation then
1570 Check_Elab_Instantiation (N, Outer_Scope);
1573 -- Skip subprogram bodies that come from source (wait for
1574 -- call to analyze these). The reason for the come from
1575 -- source test is to avoid catching task bodies.
1577 -- For task bodies, we should really avoid these too, waiting
1578 -- for the task activation, but that's too much trouble to
1579 -- catch for now, so we go in unconditionally. This is not
1580 -- so terrible, it means the error backtrace is not quite
1581 -- complete, and we are too eager to scan bodies of tasks
1582 -- that are unused, but this is hardly very significant!
1584 elsif Nkind (N) = N_Subprogram_Body
1585 and then Comes_From_Source (N)
1594 procedure Traverse is new Atree.Traverse_Proc;
1595 -- Traverse procedure using above Process function
1597 -- Start of processing for Check_Internal_Call_Continue
1600 -- Save outer level call if at outer level
1602 if Elab_Call.Last = 0 then
1603 Outer_Level_Sloc := Loc;
1606 Elab_Visited.Increment_Last;
1607 Elab_Visited.Table (Elab_Visited.Last) := E;
1609 -- If the call is to a function that renames a literal, no check
1612 if Ekind (E) = E_Enumeration_Literal then
1616 Sbody := Unit_Declaration_Node (E);
1618 if Nkind (Sbody) /= N_Subprogram_Body
1620 Nkind (Sbody) /= N_Package_Body
1622 Ebody := Corresponding_Body (Sbody);
1627 Sbody := Unit_Declaration_Node (Ebody);
1631 -- If the body appears after the outer level call or
1632 -- instantiation then we have an error case handled below.
1634 if Earlier_In_Extended_Unit (Outer_Level_Sloc, Sloc (Sbody))
1635 and then not In_Task_Activation
1639 -- If we have the instantiation case we are done, since we now
1640 -- know that the body of the generic appeared earlier.
1642 elsif Inst_Case then
1645 -- Otherwise we have a call, so we trace through the called
1646 -- body to see if it has any problems ..
1649 pragma Assert (Nkind (Sbody) = N_Subprogram_Body);
1651 Elab_Call.Increment_Last;
1652 Elab_Call.Table (Elab_Call.Last).Cloc := Loc;
1653 Elab_Call.Table (Elab_Call.Last).Ent := E;
1655 if Debug_Flag_LL then
1656 Write_Str ("Elab_Call.Last = ");
1657 Write_Int (Int (Elab_Call.Last));
1658 Write_Str (" Ent = ");
1659 Write_Name (Chars (E));
1661 Write_Location (Sloc (N));
1665 -- Now traverse declarations and statements of subprogram body.
1666 -- Note that we cannot simply Traverse (Sbody), since traverse
1667 -- does not normally visit subprogram bodies.
1670 Decl : Node_Id := First (Declarations (Sbody));
1673 while Present (Decl) loop
1679 Traverse (Handled_Statement_Sequence (Sbody));
1681 Elab_Call.Decrement_Last;
1685 -- Here is the case of calling a subprogram where the body has
1686 -- not yet been encountered, a warning message is needed.
1688 -- If we have nothing in the call stack, then this is at the
1689 -- outer level, and the ABE is bound to occur.
1691 if Elab_Call.Last = 0 then
1694 ("?cannot instantiate& before body seen", N, Orig_Ent);
1697 ("?cannot call& before body seen", N, Orig_Ent);
1701 ("\?Program_Error will be raised at run time", N);
1702 Insert_Elab_Check (N);
1704 -- Call is not at outer level
1707 -- Deal with dynamic elaboration check
1709 if not Elaboration_Checks_Suppressed (E) then
1710 Set_Elaboration_Entity_Required (E);
1712 -- Case of no elaboration entity allocated yet
1714 if No (Elaboration_Entity (E)) then
1716 -- Create object declaration for elaboration entity, and put it
1717 -- just in front of the spec of the subprogram or generic unit,
1718 -- in the same scope as this unit.
1721 Loce : constant Source_Ptr := Sloc (E);
1722 Ent : constant Entity_Id :=
1723 Make_Defining_Identifier (Loc,
1724 Chars => New_External_Name (Chars (E), 'E'));
1727 Set_Elaboration_Entity (E, Ent);
1728 New_Scope (Scope (E));
1730 Insert_Action (Declaration_Node (E),
1731 Make_Object_Declaration (Loce,
1732 Defining_Identifier => Ent,
1733 Object_Definition =>
1734 New_Occurrence_Of (Standard_Boolean, Loce),
1735 Expression => New_Occurrence_Of (Standard_False, Loce)));
1737 -- Set elaboration flag at the point of the body
1739 Set_Elaboration_Flag (Sbody, E);
1741 -- Kill current value indication. This is necessary
1742 -- because the tests of this flag are inserted out of
1743 -- sequence and must not pick up bogus indications of
1744 -- the wrong constant value. Also, this is never a true
1745 -- constant, since one way or another, it gets reset.
1747 Set_Current_Value (Ent, Empty);
1748 Set_Is_True_Constant (Ent, False);
1753 -- Generate check of the elaboration Boolean
1755 Insert_Elab_Check (N,
1756 New_Occurrence_Of (Elaboration_Entity (E), Loc));
1759 -- Generate the warning
1761 if not Suppress_Elaboration_Warnings (E)
1762 and then not Elaboration_Checks_Suppressed (E)
1766 ("instantiation of& may occur before body is seen?",
1770 ("call to& may occur before body is seen?", N, Orig_Ent);
1774 ("\Program_Error may be raised at run time?", N);
1780 -- Set flag to suppress further warnings on same subprogram
1781 -- unless in all errors mode
1783 if not All_Errors_Mode then
1784 Set_Suppress_Elaboration_Warnings (E);
1786 end Check_Internal_Call_Continue;
1788 ---------------------------
1789 -- Check_Task_Activation --
1790 ---------------------------
1792 procedure Check_Task_Activation (N : Node_Id) is
1793 Loc : constant Source_Ptr := Sloc (N);
1794 Inter_Procs : constant Elist_Id := New_Elmt_List;
1795 Intra_Procs : constant Elist_Id := New_Elmt_List;
1798 Task_Scope : Entity_Id;
1799 Cunit_SC : Boolean := False;
1802 Enclosing : Entity_Id;
1804 procedure Add_Task_Proc (Typ : Entity_Id);
1805 -- Add to Task_Procs the task body procedure(s) of task types in Typ.
1806 -- For record types, this procedure recurses over component types.
1808 procedure Collect_Tasks (Decls : List_Id);
1809 -- Collect the types of the tasks that are to be activated in the given
1810 -- list of declarations, in order to perform elaboration checks on the
1811 -- corresponding task procedures which are called implicitly here.
1813 function Outer_Unit (E : Entity_Id) return Entity_Id;
1814 -- find enclosing compilation unit of Entity, ignoring subunits, or
1815 -- else enclosing subprogram. If E is not a package, there is no need
1816 -- for inter-unit elaboration checks.
1822 procedure Add_Task_Proc (Typ : Entity_Id) is
1824 Proc : Entity_Id := Empty;
1827 if Is_Task_Type (Typ) then
1828 Proc := Get_Task_Body_Procedure (Typ);
1830 elsif Is_Array_Type (Typ)
1831 and then Has_Task (Base_Type (Typ))
1833 Add_Task_Proc (Component_Type (Typ));
1835 elsif Is_Record_Type (Typ)
1836 and then Has_Task (Base_Type (Typ))
1838 Comp := First_Component (Typ);
1840 while Present (Comp) loop
1841 Add_Task_Proc (Etype (Comp));
1842 Comp := Next_Component (Comp);
1846 -- If the task type is another unit, we will perform the usual
1847 -- elaboration check on its enclosing unit. If the type is in the
1848 -- same unit, we can trace the task body as for an internal call,
1849 -- but we only need to examine other external calls, because at
1850 -- the point the task is activated, internal subprogram bodies
1851 -- will have been elaborated already. We keep separate lists for
1852 -- each kind of task.
1854 -- Skip this test if errors have occurred, since in this case
1855 -- we can get false indications.
1857 if Serious_Errors_Detected /= 0 then
1861 if Present (Proc) then
1862 if Outer_Unit (Scope (Proc)) = Enclosing then
1864 if No (Corresponding_Body (Unit_Declaration_Node (Proc)))
1866 (not Is_Generic_Instance (Scope (Proc))
1868 Scope (Proc) = Scope (Defining_Identifier (Decl)))
1871 ("task will be activated before elaboration of its body?",
1874 ("Program_Error will be raised at run-time?", Decl);
1877 Present (Corresponding_Body (Unit_Declaration_Node (Proc)))
1879 Append_Elmt (Proc, Intra_Procs);
1883 Elmt := First_Elmt (Inter_Procs);
1885 -- No need for multiple entries of the same type.
1887 while Present (Elmt) loop
1888 if Node (Elmt) = Proc then
1895 Append_Elmt (Proc, Inter_Procs);
1904 procedure Collect_Tasks (Decls : List_Id) is
1906 if Present (Decls) then
1907 Decl := First (Decls);
1909 while Present (Decl) loop
1911 if Nkind (Decl) = N_Object_Declaration
1912 and then Has_Task (Etype (Defining_Identifier (Decl)))
1914 Add_Task_Proc (Etype (Defining_Identifier (Decl)));
1926 function Outer_Unit (E : Entity_Id) return Entity_Id is
1927 Outer : Entity_Id := E;
1930 while Present (Outer) loop
1931 if Elaboration_Checks_Suppressed (Outer) then
1935 exit when Is_Child_Unit (Outer)
1936 or else Scope (Outer) = Standard_Standard
1937 or else Ekind (Outer) /= E_Package;
1938 Outer := Scope (Outer);
1944 -- Start of processing for Check_Task_Activation
1947 Enclosing := Outer_Unit (Current_Scope);
1949 -- Find all tasks declared in the current unit.
1951 if Nkind (N) = N_Package_Body then
1952 P := Unit_Declaration_Node (Corresponding_Spec (N));
1954 Collect_Tasks (Declarations (N));
1955 Collect_Tasks (Visible_Declarations (Specification (P)));
1956 Collect_Tasks (Private_Declarations (Specification (P)));
1958 elsif Nkind (N) = N_Package_Declaration then
1959 Collect_Tasks (Visible_Declarations (Specification (N)));
1960 Collect_Tasks (Private_Declarations (Specification (N)));
1963 Collect_Tasks (Declarations (N));
1966 -- We only perform detailed checks in all tasks are library level
1967 -- entities. If the master is a subprogram or task, activation will
1968 -- depend on the activation of the master itself.
1969 -- Should dynamic checks be added in the more general case???
1971 if Ekind (Enclosing) /= E_Package then
1975 -- For task types defined in other units, we want the unit containing
1976 -- the task body to be elaborated before the current one.
1978 Elmt := First_Elmt (Inter_Procs);
1980 while Present (Elmt) loop
1982 Task_Scope := Outer_Unit (Scope (Ent));
1984 if not Is_Compilation_Unit (Task_Scope) then
1987 elsif Suppress_Elaboration_Warnings (Task_Scope)
1988 or else Elaboration_Checks_Suppressed (Task_Scope)
1992 elsif Dynamic_Elaboration_Checks then
1993 if not Elaboration_Checks_Suppressed (Ent)
1994 and then not Cunit_SC
1996 not Restriction_Active (No_Entry_Calls_In_Elaboration_Code)
1998 -- Runtime elaboration check required. generate check of the
1999 -- elaboration Boolean for the unit containing the entity.
2001 Insert_Elab_Check (N,
2002 Make_Attribute_Reference (Loc,
2003 Attribute_Name => Name_Elaborated,
2006 (Spec_Entity (Task_Scope), Loc)));
2010 -- Force the binder to elaborate other unit first
2012 if not Suppress_Elaboration_Warnings (Ent)
2013 and then not Elaboration_Checks_Suppressed (Ent)
2014 and then Elab_Warnings
2015 and then not Suppress_Elaboration_Warnings (Task_Scope)
2016 and then not Elaboration_Checks_Suppressed (Task_Scope)
2018 Error_Msg_Node_2 := Task_Scope;
2019 Error_Msg_NE ("activation of an instance of task type&" &
2020 " requires pragma Elaborate_All on &?", N, Ent);
2023 Set_Elaborate_All_Desirable (Task_Scope);
2024 Set_Suppress_Elaboration_Warnings (Task_Scope);
2030 -- For tasks declared in the current unit, trace other calls within
2031 -- the task procedure bodies, which are available.
2033 In_Task_Activation := True;
2034 Elmt := First_Elmt (Intra_Procs);
2036 while Present (Elmt) loop
2038 Check_Internal_Call_Continue (N, Ent, Enclosing, Ent);
2042 In_Task_Activation := False;
2043 end Check_Task_Activation;
2045 --------------------------------
2046 -- Set_Elaboration_Constraint --
2047 --------------------------------
2049 procedure Set_Elaboration_Constraint
2054 Elab_Unit : Entity_Id;
2055 Init_Call : constant Boolean :=
2056 Chars (Subp) = Name_Initialize
2057 and then Comes_From_Source (Subp)
2058 and then Present (Parameter_Associations (Call))
2059 and then Is_Controlled
2060 (Etype (First (Parameter_Associations (Call))));
2062 -- If the unit is mentioned in a with_clause of the current
2063 -- unit, it is visible, and we can set the elaboration flag.
2065 if Is_Immediately_Visible (Scop)
2067 (Is_Child_Unit (Scop) and then Is_Visible_Child_Unit (Scop))
2069 Set_Elaborate_All_Desirable (Scop);
2070 Set_Suppress_Elaboration_Warnings (Scop, True);
2074 -- If this is not an initialization call or a call using object notation
2075 -- we know that the unit of the called entity is in the context, and
2076 -- we can set the flag as well. The unit need not be visible if the call
2077 -- occurs within an instantiation.
2079 if Is_Init_Proc (Subp)
2081 or else Nkind (Original_Node (Call)) = N_Selected_Component
2083 null; -- detailed processing follows.
2086 Set_Elaborate_All_Desirable (Scop);
2087 Set_Suppress_Elaboration_Warnings (Scop, True);
2091 -- If the unit is not in the context, there must be an intermediate
2092 -- unit that is, on which we need to place to elaboration flag.
2094 if Is_Init_Proc (Subp)
2097 -- The initialization call is on an object whose type is not
2098 -- declared in the same scope as the subprogram. The type of
2099 -- the object must be a subtype of the type of operation. This
2100 -- object is the first actual in the call.
2103 Typ : constant Entity_Id :=
2104 Etype (First (Parameter_Associations (Call)));
2106 Elab_Unit := Scope (Typ);
2108 while (Present (Elab_Unit))
2109 and then not Is_Compilation_Unit (Elab_Unit)
2111 Elab_Unit := Scope (Elab_Unit);
2114 elsif Nkind (Original_Node (Call)) = N_Selected_Component then
2116 -- If original node uses selected component notation, the
2117 -- prefix is visible and determines the scope that must be
2118 -- elaborated. After rewriting, the prefix is the first actual
2121 Elab_Unit := Scope (Etype (First (Parameter_Associations (Call))));
2124 -- Using previously computed scope. If the elaboration check is
2125 -- done after analysis, the scope is not visible any longer, but
2126 -- must still be in the context.
2131 Set_Elaborate_All_Desirable (Elab_Unit);
2132 Set_Suppress_Elaboration_Warnings (Elab_Unit, True);
2133 end Set_Elaboration_Constraint;
2135 ----------------------
2136 -- Has_Generic_Body --
2137 ----------------------
2139 function Has_Generic_Body (N : Node_Id) return Boolean is
2140 Ent : constant Entity_Id := Get_Generic_Entity (N);
2141 Decl : constant Node_Id := Unit_Declaration_Node (Ent);
2144 function Find_Body_In (E : Entity_Id; N : Node_Id) return Node_Id;
2145 -- Determine if the list of nodes headed by N and linked by Next
2146 -- contains a package body for the package spec entity E, and if
2147 -- so return the package body. If not, then returns Empty.
2149 function Load_Package_Body (Nam : Unit_Name_Type) return Node_Id;
2150 -- This procedure is called load the unit whose name is given by Nam.
2151 -- This unit is being loaded to see whether it contains an optional
2152 -- generic body. The returned value is the loaded unit, which is
2153 -- always a package body (only package bodies can contain other
2154 -- entities in the sense in which Has_Generic_Body is interested).
2155 -- We only attempt to load bodies if we are generating code. If we
2156 -- are in semantics check only mode, then it would be wrong to load
2157 -- bodies that are not required from a semantic point of view, so
2158 -- in this case we return Empty. The result is that the caller may
2159 -- incorrectly decide that a generic spec does not have a body when
2160 -- in fact it does, but the only harm in this is that some warnings
2161 -- on elaboration problems may be lost in semantic checks only mode,
2162 -- which is not big loss. We also return Empty if we go for a body
2163 -- and it is not there.
2165 function Locate_Corresponding_Body (PE : Entity_Id) return Node_Id;
2166 -- PE is the entity for a package spec. This function locates the
2167 -- corresponding package body, returning Empty if none is found.
2168 -- The package body returned is fully parsed but may not yet be
2169 -- analyzed, so only syntactic fields should be referenced.
2175 function Find_Body_In (E : Entity_Id; N : Node_Id) return Node_Id is
2180 while Present (Nod) loop
2182 -- If we found the package body we are looking for, return it
2184 if Nkind (Nod) = N_Package_Body
2185 and then Chars (Defining_Unit_Name (Nod)) = Chars (E)
2189 -- If we found the stub for the body, go after the subunit,
2190 -- loading it if necessary.
2192 elsif Nkind (Nod) = N_Package_Body_Stub
2193 and then Chars (Defining_Identifier (Nod)) = Chars (E)
2195 if Present (Library_Unit (Nod)) then
2196 return Unit (Library_Unit (Nod));
2199 return Load_Package_Body (Get_Unit_Name (Nod));
2202 -- If neither package body nor stub, keep looking on chain
2212 -----------------------
2213 -- Load_Package_Body --
2214 -----------------------
2216 function Load_Package_Body (Nam : Unit_Name_Type) return Node_Id is
2217 U : Unit_Number_Type;
2220 if Operating_Mode /= Generate_Code then
2233 return Unit (Cunit (U));
2236 end Load_Package_Body;
2238 -------------------------------
2239 -- Locate_Corresponding_Body --
2240 -------------------------------
2242 function Locate_Corresponding_Body (PE : Entity_Id) return Node_Id is
2243 Spec : constant Node_Id := Declaration_Node (PE);
2244 Decl : constant Node_Id := Parent (Spec);
2245 Scop : constant Entity_Id := Scope (PE);
2249 if Is_Library_Level_Entity (PE) then
2251 -- If package is a library unit that requires a body, we have
2252 -- no choice but to go after that body because it might contain
2253 -- an optional body for the original generic package.
2255 if Unit_Requires_Body (PE) then
2257 -- Load the body. Note that we are a little careful here to
2258 -- use Spec to get the unit number, rather than PE or Decl,
2259 -- since in the case where the package is itself a library
2260 -- level instantiation, Spec will properly reference the
2261 -- generic template, which is what we really want.
2265 (Get_Body_Name (Unit_Name (Get_Source_Unit (Spec))));
2267 -- But if the package is a library unit that does NOT require
2268 -- a body, then no body is permitted, so we are sure that there
2269 -- is no body for the original generic package.
2275 -- Otherwise look and see if we are embedded in a further package
2277 elsif Is_Package (Scop) then
2279 -- If so, get the body of the enclosing package, and look in
2280 -- its package body for the package body we are looking for.
2282 PBody := Locate_Corresponding_Body (Scop);
2287 return Find_Body_In (PE, First (Declarations (PBody)));
2290 -- If we are not embedded in a further package, then the body
2291 -- must be in the same declarative part as we are.
2294 return Find_Body_In (PE, Next (Decl));
2296 end Locate_Corresponding_Body;
2298 -- Start of processing for Has_Generic_Body
2301 if Present (Corresponding_Body (Decl)) then
2304 elsif Unit_Requires_Body (Ent) then
2307 -- Compilation units cannot have optional bodies
2309 elsif Is_Compilation_Unit (Ent) then
2312 -- Otherwise look at what scope we are in
2315 Scop := Scope (Ent);
2317 -- Case of entity is in other than a package spec, in this case
2318 -- the body, if present, must be in the same declarative part.
2320 if not Is_Package (Scop) then
2325 P := Declaration_Node (Ent);
2327 -- Declaration node may get us a spec, so if so, go to
2328 -- the parent declaration.
2330 while not Is_List_Member (P) loop
2334 return Present (Find_Body_In (Ent, Next (P)));
2337 -- If the entity is in a package spec, then we have to locate
2338 -- the corresponding package body, and look there.
2342 PBody : constant Node_Id := Locate_Corresponding_Body (Scop);
2350 (Find_Body_In (Ent, (First (Declarations (PBody)))));
2355 end Has_Generic_Body;
2357 -----------------------
2358 -- Insert_Elab_Check --
2359 -----------------------
2361 procedure Insert_Elab_Check (N : Node_Id; C : Node_Id := Empty) is
2363 Loc : constant Source_Ptr := Sloc (N);
2366 -- If expansion is disabled, do not generate any checks. Also
2367 -- skip checks if any subunits are missing because in either
2368 -- case we lack the full information that we need, and no object
2369 -- file will be created in any case.
2371 if not Expander_Active or else Subunits_Missing then
2375 -- If we have a generic instantiation, where Instance_Spec is set,
2376 -- then this field points to a generic instance spec that has
2377 -- been inserted before the instantiation node itself, so that
2378 -- is where we want to insert a check.
2380 if Nkind (N) in N_Generic_Instantiation
2381 and then Present (Instance_Spec (N))
2383 Nod := Instance_Spec (N);
2388 -- If we are inserting at the top level, insert in Aux_Decls
2390 if Nkind (Parent (Nod)) = N_Compilation_Unit then
2392 ADN : constant Node_Id := Aux_Decls_Node (Parent (Nod));
2398 Make_Raise_Program_Error (Loc,
2399 Reason => PE_Access_Before_Elaboration);
2402 Make_Raise_Program_Error (Loc,
2403 Condition => Make_Op_Not (Loc, C),
2404 Reason => PE_Access_Before_Elaboration);
2407 if No (Declarations (ADN)) then
2408 Set_Declarations (ADN, New_List (R));
2410 Append_To (Declarations (ADN), R);
2416 -- Otherwise just insert before the node in question. However, if
2417 -- the context of the call has already been analyzed, an insertion
2418 -- will not work if it depends on subsequent expansion (e.g. a call in
2419 -- a branch of a short-circuit). In that case we replace the call with
2420 -- a conditional expression, or with a Raise if it is unconditional.
2421 -- Unfortunately this does not work if the call has a dynamic size,
2422 -- because gigi regards it as a dynamic-sized temporary. If such a call
2423 -- appears in a short-circuit expression, the elaboration check will be
2424 -- missed (rare enough ???). Otherwise, the code below inserts the check
2425 -- at the appropriate place before the call. Same applies in the even
2426 -- rarer case the return type has a known size but is unconstrained.
2429 if Nkind (N) = N_Function_Call
2430 and then Analyzed (Parent (N))
2431 and then Size_Known_At_Compile_Time (Etype (N))
2433 (not Has_Discriminants (Etype (N))
2434 or else Is_Constrained (Etype (N)))
2438 Typ : constant Entity_Id := Etype (N);
2439 Chk : constant Boolean := Do_Range_Check (N);
2441 R : constant Node_Id :=
2442 Make_Raise_Program_Error (Loc,
2443 Reason => PE_Access_Before_Elaboration);
2453 Make_Conditional_Expression (Loc,
2454 Expressions => New_List (C, Relocate_Node (N), R)));
2457 Analyze_And_Resolve (N, Typ);
2459 -- If the original call requires a range check, so does the
2460 -- conditional expression.
2463 Enable_Range_Check (N);
2465 Set_Do_Range_Check (N, False);
2472 Make_Raise_Program_Error (Loc,
2473 Reason => PE_Access_Before_Elaboration));
2476 Make_Raise_Program_Error (Loc,
2480 Reason => PE_Access_Before_Elaboration));
2484 end Insert_Elab_Check;
2490 procedure Output_Calls (N : Node_Id) is
2493 function Is_Printable_Error_Name (Nm : Name_Id) return Boolean;
2494 -- An internal function, used to determine if a name, Nm, is either
2495 -- a non-internal name, or is an internal name that is printable
2496 -- by the error message circuits (i.e. it has a single upper
2497 -- case letter at the end).
2499 function Is_Printable_Error_Name (Nm : Name_Id) return Boolean is
2501 if not Is_Internal_Name (Nm) then
2504 elsif Name_Len = 1 then
2508 Name_Len := Name_Len - 1;
2509 return not Is_Internal_Name;
2511 end Is_Printable_Error_Name;
2513 -- Start of processing for Output_Calls
2516 for J in reverse 1 .. Elab_Call.Last loop
2517 Error_Msg_Sloc := Elab_Call.Table (J).Cloc;
2519 Ent := Elab_Call.Table (J).Ent;
2521 if Is_Generic_Unit (Ent) then
2522 Error_Msg_NE ("\?& instantiated #", N, Ent);
2524 elsif Is_Init_Proc (Ent) then
2525 Error_Msg_N ("\?initialization procedure called #", N);
2527 elsif Is_Printable_Error_Name (Chars (Ent)) then
2528 Error_Msg_NE ("\?& called #", N, Ent);
2531 Error_Msg_N ("\? called #", N);
2536 ----------------------------
2537 -- Same_Elaboration_Scope --
2538 ----------------------------
2540 function Same_Elaboration_Scope (Scop1, Scop2 : Entity_Id) return Boolean is
2541 S1 : Entity_Id := Scop1;
2542 S2 : Entity_Id := Scop2;
2545 while S1 /= Standard_Standard
2546 and then (Ekind (S1) = E_Package
2548 Ekind (S1) = E_Block)
2553 while S2 /= Standard_Standard
2554 and then (Ekind (S2) = E_Package
2556 Ekind (S2) = E_Protected_Type
2558 Ekind (S2) = E_Block)
2564 end Same_Elaboration_Scope;
2570 procedure Set_C_Scope is
2572 while not Is_Compilation_Unit (C_Scope) loop
2573 C_Scope := Scope (C_Scope);
2581 function Spec_Entity (E : Entity_Id) return Entity_Id is
2585 -- Check for case of body entity
2586 -- Why is the check for E_Void needed???
2588 if Ekind (E) = E_Void
2589 or else Ekind (E) = E_Subprogram_Body
2590 or else Ekind (E) = E_Package_Body
2595 Decl := Parent (Decl);
2596 exit when Nkind (Decl) in N_Proper_Body;
2599 return Corresponding_Spec (Decl);
2610 procedure Supply_Bodies (N : Node_Id) is
2612 if Nkind (N) = N_Subprogram_Declaration then
2614 Ent : constant Entity_Id := Defining_Unit_Name (Specification (N));
2617 Set_Is_Imported (Ent);
2618 Set_Convention (Ent, Convention_Stubbed);
2621 elsif Nkind (N) = N_Package_Declaration then
2623 Spec : constant Node_Id := Specification (N);
2626 New_Scope (Defining_Unit_Name (Spec));
2627 Supply_Bodies (Visible_Declarations (Spec));
2628 Supply_Bodies (Private_Declarations (Spec));
2634 procedure Supply_Bodies (L : List_Id) is
2640 while Present (Elmt) loop
2641 Supply_Bodies (Elmt);
2651 function Within (E1, E2 : Entity_Id) return Boolean is
2661 elsif Scop = Standard_Standard then
2665 Scop := Scope (Scop);
2669 raise Program_Error;
2672 --------------------------
2673 -- Within_Elaborate_All --
2674 --------------------------
2676 function Within_Elaborate_All (E : Entity_Id) return Boolean is
2679 Elab_Id : Entity_Id;
2683 Item := First (Context_Items (Cunit (Current_Sem_Unit)));
2685 while Present (Item) loop
2686 if Nkind (Item) = N_Pragma
2687 and then Get_Pragma_Id (Chars (Item)) = Pragma_Elaborate_All
2689 if Error_Posted (Item) then
2691 -- Some previous error on the pragma itself
2698 Expression (First (Pragma_Argument_Associations (Item))));
2700 Par := Parent (Unit_Declaration_Node (Elab_Id));
2701 Item2 := First (Context_Items (Par));
2703 while Present (Item2) loop
2704 if Nkind (Item2) = N_With_Clause
2705 and then Entity (Name (Item2)) = E
2718 end Within_Elaborate_All;