1 -----------------------------------------------------------------------------
3 -- GNAT COMPILER COMPONENTS --
9 -- Copyright (C) 1992-2008, 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 Checks; use Checks;
28 with Debug; use Debug;
29 with Einfo; use Einfo;
30 with Errout; use Errout;
31 with Elists; use Elists;
32 with Exp_Atag; use Exp_Atag;
33 with Exp_Ch2; use Exp_Ch2;
34 with Exp_Ch3; use Exp_Ch3;
35 with Exp_Ch7; use Exp_Ch7;
36 with Exp_Ch9; use Exp_Ch9;
37 with Exp_Dbug; use Exp_Dbug;
38 with Exp_Disp; use Exp_Disp;
39 with Exp_Dist; use Exp_Dist;
40 with Exp_Intr; use Exp_Intr;
41 with Exp_Pakd; use Exp_Pakd;
42 with Exp_Tss; use Exp_Tss;
43 with Exp_Util; use Exp_Util;
44 with Exp_VFpt; use Exp_VFpt;
45 with Fname; use Fname;
46 with Freeze; use Freeze;
47 with Inline; use Inline;
49 with Namet; use Namet;
50 with Nlists; use Nlists;
51 with Nmake; use Nmake;
53 with Restrict; use Restrict;
54 with Rident; use Rident;
55 with Rtsfind; use Rtsfind;
57 with Sem_Ch6; use Sem_Ch6;
58 with Sem_Ch8; use Sem_Ch8;
59 with Sem_Ch12; use Sem_Ch12;
60 with Sem_Ch13; use Sem_Ch13;
61 with Sem_Eval; use Sem_Eval;
62 with Sem_Disp; use Sem_Disp;
63 with Sem_Dist; use Sem_Dist;
64 with Sem_Mech; use Sem_Mech;
65 with Sem_Res; use Sem_Res;
66 with Sem_Util; use Sem_Util;
67 with Sinfo; use Sinfo;
68 with Snames; use Snames;
69 with Stand; use Stand;
70 with Targparm; use Targparm;
71 with Tbuild; use Tbuild;
72 with Uintp; use Uintp;
73 with Validsw; use Validsw;
75 package body Exp_Ch6 is
77 -----------------------
78 -- Local Subprograms --
79 -----------------------
81 procedure Add_Access_Actual_To_Build_In_Place_Call
82 (Function_Call : Node_Id;
83 Function_Id : Entity_Id;
84 Return_Object : Node_Id;
85 Is_Access : Boolean := False);
86 -- Ada 2005 (AI-318-02): Apply the Unrestricted_Access attribute to the
87 -- object name given by Return_Object and add the attribute to the end of
88 -- the actual parameter list associated with the build-in-place function
89 -- call denoted by Function_Call. However, if Is_Access is True, then
90 -- Return_Object is already an access expression, in which case it's passed
91 -- along directly to the build-in-place function. Finally, if Return_Object
92 -- is empty, then pass a null literal as the actual.
94 procedure Add_Alloc_Form_Actual_To_Build_In_Place_Call
95 (Function_Call : Node_Id;
96 Function_Id : Entity_Id;
97 Alloc_Form : BIP_Allocation_Form := Unspecified;
98 Alloc_Form_Exp : Node_Id := Empty);
99 -- Ada 2005 (AI-318-02): Add an actual indicating the form of allocation,
100 -- if any, to be done by a build-in-place function. If Alloc_Form_Exp is
101 -- present, then use it, otherwise pass a literal corresponding to the
102 -- Alloc_Form parameter (which must not be Unspecified in that case).
104 procedure Add_Extra_Actual_To_Call
105 (Subprogram_Call : Node_Id;
106 Extra_Formal : Entity_Id;
107 Extra_Actual : Node_Id);
108 -- Adds Extra_Actual as a named parameter association for the formal
109 -- Extra_Formal in Subprogram_Call.
111 procedure Add_Final_List_Actual_To_Build_In_Place_Call
112 (Function_Call : Node_Id;
113 Function_Id : Entity_Id;
114 Acc_Type : Entity_Id;
115 Sel_Comp : Node_Id := Empty);
116 -- Ada 2005 (AI-318-02): For a build-in-place call, if the result type has
117 -- controlled parts, add an actual parameter that is a pointer to
118 -- appropriate finalization list. The finalization list is that of the
119 -- current scope, except for "new Acc'(F(...))" in which case it's the
120 -- finalization list of the access type returned by the allocator. Acc_Type
121 -- is that type in the allocator case; Empty otherwise. If Sel_Comp is
122 -- not Empty, then it denotes a selected component and the finalization
123 -- list is obtained from the _controller list of the prefix object.
125 procedure Add_Task_Actuals_To_Build_In_Place_Call
126 (Function_Call : Node_Id;
127 Function_Id : Entity_Id;
128 Master_Actual : Node_Id);
129 -- Ada 2005 (AI-318-02): For a build-in-place call, if the result type
130 -- contains tasks, add two actual parameters: the master, and a pointer to
131 -- the caller's activation chain. Master_Actual is the actual parameter
132 -- expression to pass for the master. In most cases, this is the current
133 -- master (_master). The two exceptions are: If the function call is the
134 -- initialization expression for an allocator, we pass the master of the
135 -- access type. If the function call is the initialization expression for
136 -- a return object, we pass along the master passed in by the caller. The
137 -- activation chain to pass is always the local one.
139 procedure Check_Overriding_Operation (Subp : Entity_Id);
140 -- Subp is a dispatching operation. Check whether it may override an
141 -- inherited private operation, in which case its DT entry is that of
142 -- the hidden operation, not the one it may have received earlier.
143 -- This must be done before emitting the code to set the corresponding
144 -- DT to the address of the subprogram. The actual placement of Subp in
145 -- the proper place in the list of primitive operations is done in
146 -- Declare_Inherited_Private_Subprograms, which also has to deal with
147 -- implicit operations. This duplication is unavoidable for now???
149 procedure Detect_Infinite_Recursion (N : Node_Id; Spec : Entity_Id);
150 -- This procedure is called only if the subprogram body N, whose spec
151 -- has the given entity Spec, contains a parameterless recursive call.
152 -- It attempts to generate runtime code to detect if this a case of
153 -- infinite recursion.
155 -- The body is scanned to determine dependencies. If the only external
156 -- dependencies are on a small set of scalar variables, then the values
157 -- of these variables are captured on entry to the subprogram, and if
158 -- the values are not changed for the call, we know immediately that
159 -- we have an infinite recursion.
161 procedure Expand_Actuals (N : Node_Id; Subp : Entity_Id);
162 -- For each actual of an in-out or out parameter which is a numeric
163 -- (view) conversion of the form T (A), where A denotes a variable,
164 -- we insert the declaration:
166 -- Temp : T[ := T (A)];
168 -- prior to the call. Then we replace the actual with a reference to Temp,
169 -- and append the assignment:
171 -- A := TypeA (Temp);
173 -- after the call. Here TypeA is the actual type of variable A.
174 -- For out parameters, the initial declaration has no expression.
175 -- If A is not an entity name, we generate instead:
177 -- Var : TypeA renames A;
178 -- Temp : T := Var; -- omitting expression for out parameter.
180 -- Var := TypeA (Temp);
182 -- For other in-out parameters, we emit the required constraint checks
183 -- before and/or after the call.
185 -- For all parameter modes, actuals that denote components and slices
186 -- of packed arrays are expanded into suitable temporaries.
188 -- For non-scalar objects that are possibly unaligned, add call by copy
189 -- code (copy in for IN and IN OUT, copy out for OUT and IN OUT).
191 procedure Expand_Inlined_Call
194 Orig_Subp : Entity_Id);
195 -- If called subprogram can be inlined by the front-end, retrieve the
196 -- analyzed body, replace formals with actuals and expand call in place.
197 -- Generate thunks for actuals that are expressions, and insert the
198 -- corresponding constant declarations before the call. If the original
199 -- call is to a derived operation, the return type is the one of the
200 -- derived operation, but the body is that of the original, so return
201 -- expressions in the body must be converted to the desired type (which
202 -- is simply not noted in the tree without inline expansion).
204 function Expand_Protected_Object_Reference
206 Scop : Entity_Id) return Node_Id;
208 procedure Expand_Protected_Subprogram_Call
212 -- A call to a protected subprogram within the protected object may appear
213 -- as a regular call. The list of actuals must be expanded to contain a
214 -- reference to the object itself, and the call becomes a call to the
215 -- corresponding protected subprogram.
217 ----------------------------------------------
218 -- Add_Access_Actual_To_Build_In_Place_Call --
219 ----------------------------------------------
221 procedure Add_Access_Actual_To_Build_In_Place_Call
222 (Function_Call : Node_Id;
223 Function_Id : Entity_Id;
224 Return_Object : Node_Id;
225 Is_Access : Boolean := False)
227 Loc : constant Source_Ptr := Sloc (Function_Call);
228 Obj_Address : Node_Id;
229 Obj_Acc_Formal : Entity_Id;
232 -- Locate the implicit access parameter in the called function
234 Obj_Acc_Formal := Build_In_Place_Formal (Function_Id, BIP_Object_Access);
236 -- If no return object is provided, then pass null
238 if not Present (Return_Object) then
239 Obj_Address := Make_Null (Loc);
240 Set_Parent (Obj_Address, Function_Call);
242 -- If Return_Object is already an expression of an access type, then use
243 -- it directly, since it must be an access value denoting the return
244 -- object, and couldn't possibly be the return object itself.
247 Obj_Address := Return_Object;
248 Set_Parent (Obj_Address, Function_Call);
250 -- Apply Unrestricted_Access to caller's return object
254 Make_Attribute_Reference (Loc,
255 Prefix => Return_Object,
256 Attribute_Name => Name_Unrestricted_Access);
258 Set_Parent (Return_Object, Obj_Address);
259 Set_Parent (Obj_Address, Function_Call);
262 Analyze_And_Resolve (Obj_Address, Etype (Obj_Acc_Formal));
264 -- Build the parameter association for the new actual and add it to the
265 -- end of the function's actuals.
267 Add_Extra_Actual_To_Call (Function_Call, Obj_Acc_Formal, Obj_Address);
268 end Add_Access_Actual_To_Build_In_Place_Call;
270 --------------------------------------------------
271 -- Add_Alloc_Form_Actual_To_Build_In_Place_Call --
272 --------------------------------------------------
274 procedure Add_Alloc_Form_Actual_To_Build_In_Place_Call
275 (Function_Call : Node_Id;
276 Function_Id : Entity_Id;
277 Alloc_Form : BIP_Allocation_Form := Unspecified;
278 Alloc_Form_Exp : Node_Id := Empty)
280 Loc : constant Source_Ptr := Sloc (Function_Call);
281 Alloc_Form_Actual : Node_Id;
282 Alloc_Form_Formal : Node_Id;
285 -- The allocation form generally doesn't need to be passed in the case
286 -- of a constrained result subtype, since normally the caller performs
287 -- the allocation in that case. However this formal is still needed in
288 -- the case where the function has a tagged result, because generally
289 -- such functions can be called in a dispatching context and such calls
290 -- must be handled like calls to class-wide functions.
292 if Is_Constrained (Underlying_Type (Etype (Function_Id)))
293 and then not Is_Tagged_Type (Underlying_Type (Etype (Function_Id)))
298 -- Locate the implicit allocation form parameter in the called function.
299 -- Maybe it would be better for each implicit formal of a build-in-place
300 -- function to have a flag or a Uint attribute to identify it. ???
302 Alloc_Form_Formal := Build_In_Place_Formal (Function_Id, BIP_Alloc_Form);
304 if Present (Alloc_Form_Exp) then
305 pragma Assert (Alloc_Form = Unspecified);
307 Alloc_Form_Actual := Alloc_Form_Exp;
310 pragma Assert (Alloc_Form /= Unspecified);
313 Make_Integer_Literal (Loc,
314 Intval => UI_From_Int (BIP_Allocation_Form'Pos (Alloc_Form)));
317 Analyze_And_Resolve (Alloc_Form_Actual, Etype (Alloc_Form_Formal));
319 -- Build the parameter association for the new actual and add it to the
320 -- end of the function's actuals.
322 Add_Extra_Actual_To_Call
323 (Function_Call, Alloc_Form_Formal, Alloc_Form_Actual);
324 end Add_Alloc_Form_Actual_To_Build_In_Place_Call;
326 ------------------------------
327 -- Add_Extra_Actual_To_Call --
328 ------------------------------
330 procedure Add_Extra_Actual_To_Call
331 (Subprogram_Call : Node_Id;
332 Extra_Formal : Entity_Id;
333 Extra_Actual : Node_Id)
335 Loc : constant Source_Ptr := Sloc (Subprogram_Call);
336 Param_Assoc : Node_Id;
340 Make_Parameter_Association (Loc,
341 Selector_Name => New_Occurrence_Of (Extra_Formal, Loc),
342 Explicit_Actual_Parameter => Extra_Actual);
344 Set_Parent (Param_Assoc, Subprogram_Call);
345 Set_Parent (Extra_Actual, Param_Assoc);
347 if Present (Parameter_Associations (Subprogram_Call)) then
348 if Nkind (Last (Parameter_Associations (Subprogram_Call))) =
349 N_Parameter_Association
352 -- Find last named actual, and append
357 L := First_Actual (Subprogram_Call);
358 while Present (L) loop
359 if No (Next_Actual (L)) then
360 Set_Next_Named_Actual (Parent (L), Extra_Actual);
368 Set_First_Named_Actual (Subprogram_Call, Extra_Actual);
371 Append (Param_Assoc, To => Parameter_Associations (Subprogram_Call));
374 Set_Parameter_Associations (Subprogram_Call, New_List (Param_Assoc));
375 Set_First_Named_Actual (Subprogram_Call, Extra_Actual);
377 end Add_Extra_Actual_To_Call;
379 --------------------------------------------------
380 -- Add_Final_List_Actual_To_Build_In_Place_Call --
381 --------------------------------------------------
383 procedure Add_Final_List_Actual_To_Build_In_Place_Call
384 (Function_Call : Node_Id;
385 Function_Id : Entity_Id;
386 Acc_Type : Entity_Id;
387 Sel_Comp : Node_Id := Empty)
389 Loc : constant Source_Ptr := Sloc (Function_Call);
390 Final_List : Node_Id;
391 Final_List_Actual : Node_Id;
392 Final_List_Formal : Node_Id;
393 Is_Ctrl_Result : constant Boolean :=
395 (Underlying_Type (Etype (Function_Id)));
398 -- No such extra parameter is needed if there are no controlled parts.
399 -- The test for Controlled_Type accounts for class-wide results (which
400 -- potentially have controlled parts, even if the root type doesn't),
401 -- and the test for a tagged result type is needed because calls to
402 -- such a function can in general occur in dispatching contexts, which
403 -- must be treated the same as a call to class-wide functions. Both of
404 -- these situations require that a finalization list be passed.
406 if not Is_Ctrl_Result
407 and then not Is_Tagged_Type (Underlying_Type (Etype (Function_Id)))
412 -- Locate implicit finalization list parameter in the called function
414 Final_List_Formal := Build_In_Place_Formal (Function_Id, BIP_Final_List);
416 -- Create the actual which is a pointer to the appropriate finalization
417 -- list. Acc_Type is present if and only if this call is the
418 -- initialization of an allocator. Use the Current_Scope or the Acc_Type
421 if Present (Acc_Type)
422 and then (Ekind (Acc_Type) = E_Anonymous_Access_Type
424 Present (Associated_Final_Chain (Base_Type (Acc_Type))))
426 Final_List := Find_Final_List (Acc_Type);
428 -- If Sel_Comp is present and the function result is controlled, then
429 -- the finalization list will be obtained from the _controller list of
430 -- the selected component's prefix object.
432 elsif Present (Sel_Comp) and then Is_Ctrl_Result then
433 Final_List := Find_Final_List (Current_Scope, Sel_Comp);
436 Final_List := Find_Final_List (Current_Scope);
440 Make_Attribute_Reference (Loc,
441 Prefix => Final_List,
442 Attribute_Name => Name_Unrestricted_Access);
444 Analyze_And_Resolve (Final_List_Actual, Etype (Final_List_Formal));
446 -- Build the parameter association for the new actual and add it to the
447 -- end of the function's actuals.
449 Add_Extra_Actual_To_Call
450 (Function_Call, Final_List_Formal, Final_List_Actual);
451 end Add_Final_List_Actual_To_Build_In_Place_Call;
453 ---------------------------------------------
454 -- Add_Task_Actuals_To_Build_In_Place_Call --
455 ---------------------------------------------
457 procedure Add_Task_Actuals_To_Build_In_Place_Call
458 (Function_Call : Node_Id;
459 Function_Id : Entity_Id;
460 Master_Actual : Node_Id)
461 -- Note: Master_Actual can be Empty, but only if there are no tasks
463 Loc : constant Source_Ptr := Sloc (Function_Call);
466 -- No such extra parameters are needed if there are no tasks
468 if not Has_Task (Etype (Function_Id)) then
475 Master_Formal : Node_Id;
477 -- Locate implicit master parameter in the called function
479 Master_Formal := Build_In_Place_Formal (Function_Id, BIP_Master);
481 Analyze_And_Resolve (Master_Actual, Etype (Master_Formal));
483 -- Build the parameter association for the new actual and add it to
484 -- the end of the function's actuals.
486 Add_Extra_Actual_To_Call
487 (Function_Call, Master_Formal, Master_Actual);
490 -- The activation chain
493 Activation_Chain_Actual : Node_Id;
494 Activation_Chain_Formal : Node_Id;
496 -- Locate implicit activation chain parameter in the called function
498 Activation_Chain_Formal := Build_In_Place_Formal
499 (Function_Id, BIP_Activation_Chain);
501 -- Create the actual which is a pointer to the current activation
504 Activation_Chain_Actual :=
505 Make_Attribute_Reference (Loc,
506 Prefix => Make_Identifier (Loc, Name_uChain),
507 Attribute_Name => Name_Unrestricted_Access);
510 (Activation_Chain_Actual, Etype (Activation_Chain_Formal));
512 -- Build the parameter association for the new actual and add it to
513 -- the end of the function's actuals.
515 Add_Extra_Actual_To_Call
516 (Function_Call, Activation_Chain_Formal, Activation_Chain_Actual);
518 end Add_Task_Actuals_To_Build_In_Place_Call;
520 -----------------------
521 -- BIP_Formal_Suffix --
522 -----------------------
524 function BIP_Formal_Suffix (Kind : BIP_Formal_Kind) return String is
527 when BIP_Alloc_Form =>
529 when BIP_Final_List =>
530 return "BIPfinallist";
533 when BIP_Activation_Chain =>
534 return "BIPactivationchain";
535 when BIP_Object_Access =>
538 end BIP_Formal_Suffix;
540 ---------------------------
541 -- Build_In_Place_Formal --
542 ---------------------------
544 function Build_In_Place_Formal
546 Kind : BIP_Formal_Kind) return Entity_Id
548 Extra_Formal : Entity_Id := Extra_Formals (Func);
551 -- Maybe it would be better for each implicit formal of a build-in-place
552 -- function to have a flag or a Uint attribute to identify it. ???
555 pragma Assert (Present (Extra_Formal));
557 Chars (Extra_Formal) =
558 New_External_Name (Chars (Func), BIP_Formal_Suffix (Kind));
559 Next_Formal_With_Extras (Extra_Formal);
563 end Build_In_Place_Formal;
565 --------------------------------
566 -- Check_Overriding_Operation --
567 --------------------------------
569 procedure Check_Overriding_Operation (Subp : Entity_Id) is
570 Typ : constant Entity_Id := Find_Dispatching_Type (Subp);
571 Op_List : constant Elist_Id := Primitive_Operations (Typ);
577 if Is_Derived_Type (Typ)
578 and then not Is_Private_Type (Typ)
579 and then In_Open_Scopes (Scope (Etype (Typ)))
580 and then Typ = Base_Type (Typ)
582 -- Subp overrides an inherited private operation if there is an
583 -- inherited operation with a different name than Subp (see
584 -- Derive_Subprogram) whose Alias is a hidden subprogram with the
585 -- same name as Subp.
587 Op_Elmt := First_Elmt (Op_List);
588 while Present (Op_Elmt) loop
589 Prim_Op := Node (Op_Elmt);
590 Par_Op := Alias (Prim_Op);
593 and then not Comes_From_Source (Prim_Op)
594 and then Chars (Prim_Op) /= Chars (Par_Op)
595 and then Chars (Par_Op) = Chars (Subp)
596 and then Is_Hidden (Par_Op)
597 and then Type_Conformant (Prim_Op, Subp)
599 Set_DT_Position (Subp, DT_Position (Prim_Op));
605 end Check_Overriding_Operation;
607 -------------------------------
608 -- Detect_Infinite_Recursion --
609 -------------------------------
611 procedure Detect_Infinite_Recursion (N : Node_Id; Spec : Entity_Id) is
612 Loc : constant Source_Ptr := Sloc (N);
614 Var_List : constant Elist_Id := New_Elmt_List;
615 -- List of globals referenced by body of procedure
617 Call_List : constant Elist_Id := New_Elmt_List;
618 -- List of recursive calls in body of procedure
620 Shad_List : constant Elist_Id := New_Elmt_List;
621 -- List of entity id's for entities created to capture the value of
622 -- referenced globals on entry to the procedure.
624 Scop : constant Uint := Scope_Depth (Spec);
625 -- This is used to record the scope depth of the current procedure, so
626 -- that we can identify global references.
628 Max_Vars : constant := 4;
629 -- Do not test more than four global variables
631 Count_Vars : Natural := 0;
632 -- Count variables found so far
644 function Process (Nod : Node_Id) return Traverse_Result;
645 -- Function to traverse the subprogram body (using Traverse_Func)
651 function Process (Nod : Node_Id) return Traverse_Result is
655 if Nkind (Nod) = N_Procedure_Call_Statement then
657 -- Case of one of the detected recursive calls
659 if Is_Entity_Name (Name (Nod))
660 and then Has_Recursive_Call (Entity (Name (Nod)))
661 and then Entity (Name (Nod)) = Spec
663 Append_Elmt (Nod, Call_List);
666 -- Any other procedure call may have side effects
672 -- A call to a pure function can always be ignored
674 elsif Nkind (Nod) = N_Function_Call
675 and then Is_Entity_Name (Name (Nod))
676 and then Is_Pure (Entity (Name (Nod)))
680 -- Case of an identifier reference
682 elsif Nkind (Nod) = N_Identifier then
685 -- If no entity, then ignore the reference
687 -- Not clear why this can happen. To investigate, remove this
688 -- test and look at the crash that occurs here in 3401-004 ???
693 -- Ignore entities with no Scope, again not clear how this
694 -- can happen, to investigate, look at 4108-008 ???
696 elsif No (Scope (Ent)) then
699 -- Ignore the reference if not to a more global object
701 elsif Scope_Depth (Scope (Ent)) >= Scop then
704 -- References to types, exceptions and constants are always OK
707 or else Ekind (Ent) = E_Exception
708 or else Ekind (Ent) = E_Constant
712 -- If other than a non-volatile scalar variable, we have some
713 -- kind of global reference (e.g. to a function) that we cannot
714 -- deal with so we forget the attempt.
716 elsif Ekind (Ent) /= E_Variable
717 or else not Is_Scalar_Type (Etype (Ent))
718 or else Treat_As_Volatile (Ent)
722 -- Otherwise we have a reference to a global scalar
725 -- Loop through global entities already detected
727 Elm := First_Elmt (Var_List);
729 -- If not detected before, record this new global reference
732 Count_Vars := Count_Vars + 1;
734 if Count_Vars <= Max_Vars then
735 Append_Elmt (Entity (Nod), Var_List);
742 -- If recorded before, ignore
744 elsif Node (Elm) = Entity (Nod) then
747 -- Otherwise keep looking
757 -- For all other node kinds, recursively visit syntactic children
764 function Traverse_Body is new Traverse_Func (Process);
766 -- Start of processing for Detect_Infinite_Recursion
769 -- Do not attempt detection in No_Implicit_Conditional mode, since we
770 -- won't be able to generate the code to handle the recursion in any
773 if Restriction_Active (No_Implicit_Conditionals) then
777 -- Otherwise do traversal and quit if we get abandon signal
779 if Traverse_Body (N) = Abandon then
782 -- We must have a call, since Has_Recursive_Call was set. If not just
783 -- ignore (this is only an error check, so if we have a funny situation,
784 -- due to bugs or errors, we do not want to bomb!)
786 elsif Is_Empty_Elmt_List (Call_List) then
790 -- Here is the case where we detect recursion at compile time
792 -- Push our current scope for analyzing the declarations and code that
793 -- we will insert for the checking.
797 -- This loop builds temporary variables for each of the referenced
798 -- globals, so that at the end of the loop the list Shad_List contains
799 -- these temporaries in one-to-one correspondence with the elements in
803 Elm := First_Elmt (Var_List);
804 while Present (Elm) loop
807 Make_Defining_Identifier (Loc,
808 Chars => New_Internal_Name ('S'));
809 Append_Elmt (Ent, Shad_List);
811 -- Insert a declaration for this temporary at the start of the
812 -- declarations for the procedure. The temporaries are declared as
813 -- constant objects initialized to the current values of the
814 -- corresponding temporaries.
817 Make_Object_Declaration (Loc,
818 Defining_Identifier => Ent,
819 Object_Definition => New_Occurrence_Of (Etype (Var), Loc),
820 Constant_Present => True,
821 Expression => New_Occurrence_Of (Var, Loc));
824 Prepend (Decl, Declarations (N));
826 Insert_After (Last, Decl);
834 -- Loop through calls
836 Call := First_Elmt (Call_List);
837 while Present (Call) loop
839 -- Build a predicate expression of the form
842 -- and then global1 = temp1
843 -- and then global2 = temp2
846 -- This predicate determines if any of the global values
847 -- referenced by the procedure have changed since the
848 -- current call, if not an infinite recursion is assured.
850 Test := New_Occurrence_Of (Standard_True, Loc);
852 Elm1 := First_Elmt (Var_List);
853 Elm2 := First_Elmt (Shad_List);
854 while Present (Elm1) loop
860 Left_Opnd => New_Occurrence_Of (Node (Elm1), Loc),
861 Right_Opnd => New_Occurrence_Of (Node (Elm2), Loc)));
867 -- Now we replace the call with the sequence
869 -- if no-changes (see above) then
870 -- raise Storage_Error;
875 Rewrite (Node (Call),
876 Make_If_Statement (Loc,
878 Then_Statements => New_List (
879 Make_Raise_Storage_Error (Loc,
880 Reason => SE_Infinite_Recursion)),
882 Else_Statements => New_List (
883 Relocate_Node (Node (Call)))));
885 Analyze (Node (Call));
890 -- Remove temporary scope stack entry used for analysis
893 end Detect_Infinite_Recursion;
899 procedure Expand_Actuals (N : Node_Id; Subp : Entity_Id) is
900 Loc : constant Source_Ptr := Sloc (N);
905 E_Formal : Entity_Id;
907 procedure Add_Call_By_Copy_Code;
908 -- For cases where the parameter must be passed by copy, this routine
909 -- generates a temporary variable into which the actual is copied and
910 -- then passes this as the parameter. For an OUT or IN OUT parameter,
911 -- an assignment is also generated to copy the result back. The call
912 -- also takes care of any constraint checks required for the type
913 -- conversion case (on both the way in and the way out).
915 procedure Add_Simple_Call_By_Copy_Code;
916 -- This is similar to the above, but is used in cases where we know
917 -- that all that is needed is to simply create a temporary and copy
918 -- the value in and out of the temporary.
920 procedure Check_Fortran_Logical;
921 -- A value of type Logical that is passed through a formal parameter
922 -- must be normalized because .TRUE. usually does not have the same
923 -- representation as True. We assume that .FALSE. = False = 0.
924 -- What about functions that return a logical type ???
926 function Is_Legal_Copy return Boolean;
927 -- Check that an actual can be copied before generating the temporary
928 -- to be used in the call. If the actual is of a by_reference type then
929 -- the program is illegal (this can only happen in the presence of
930 -- rep. clauses that force an incorrect alignment). If the formal is
931 -- a by_reference parameter imposed by a DEC pragma, emit a warning to
932 -- the effect that this might lead to unaligned arguments.
934 function Make_Var (Actual : Node_Id) return Entity_Id;
935 -- Returns an entity that refers to the given actual parameter,
936 -- Actual (not including any type conversion). If Actual is an
937 -- entity name, then this entity is returned unchanged, otherwise
938 -- a renaming is created to provide an entity for the actual.
940 procedure Reset_Packed_Prefix;
941 -- The expansion of a packed array component reference is delayed in
942 -- the context of a call. Now we need to complete the expansion, so we
943 -- unmark the analyzed bits in all prefixes.
945 ---------------------------
946 -- Add_Call_By_Copy_Code --
947 ---------------------------
949 procedure Add_Call_By_Copy_Code is
955 F_Typ : constant Entity_Id := Etype (Formal);
960 if not Is_Legal_Copy then
965 Make_Defining_Identifier (Loc,
966 Chars => New_Internal_Name ('T'));
968 -- Use formal type for temp, unless formal type is an unconstrained
969 -- array, in which case we don't have to worry about bounds checks,
970 -- and we use the actual type, since that has appropriate bounds.
972 if Is_Array_Type (F_Typ) and then not Is_Constrained (F_Typ) then
973 Indic := New_Occurrence_Of (Etype (Actual), Loc);
975 Indic := New_Occurrence_Of (Etype (Formal), Loc);
978 if Nkind (Actual) = N_Type_Conversion then
979 V_Typ := Etype (Expression (Actual));
981 -- If the formal is an (in-)out parameter, capture the name
982 -- of the variable in order to build the post-call assignment.
984 Var := Make_Var (Expression (Actual));
986 Crep := not Same_Representation
987 (F_Typ, Etype (Expression (Actual)));
990 V_Typ := Etype (Actual);
991 Var := Make_Var (Actual);
995 -- Setup initialization for case of in out parameter, or an out
996 -- parameter where the formal is an unconstrained array (in the
997 -- latter case, we have to pass in an object with bounds).
999 -- If this is an out parameter, the initial copy is wasteful, so as
1000 -- an optimization for the one-dimensional case we extract the
1001 -- bounds of the actual and build an uninitialized temporary of the
1004 if Ekind (Formal) = E_In_Out_Parameter
1005 or else (Is_Array_Type (F_Typ) and then not Is_Constrained (F_Typ))
1007 if Nkind (Actual) = N_Type_Conversion then
1008 if Conversion_OK (Actual) then
1009 Init := OK_Convert_To (F_Typ, New_Occurrence_Of (Var, Loc));
1011 Init := Convert_To (F_Typ, New_Occurrence_Of (Var, Loc));
1014 elsif Ekind (Formal) = E_Out_Parameter
1015 and then Is_Array_Type (F_Typ)
1016 and then Number_Dimensions (F_Typ) = 1
1017 and then not Has_Non_Null_Base_Init_Proc (F_Typ)
1019 -- Actual is a one-dimensional array or slice, and the type
1020 -- requires no initialization. Create a temporary of the
1021 -- right size, but do not copy actual into it (optimization).
1025 Make_Subtype_Indication (Loc,
1027 New_Occurrence_Of (F_Typ, Loc),
1029 Make_Index_Or_Discriminant_Constraint (Loc,
1030 Constraints => New_List (
1033 Make_Attribute_Reference (Loc,
1034 Prefix => New_Occurrence_Of (Var, Loc),
1035 Attribute_Name => Name_First),
1037 Make_Attribute_Reference (Loc,
1038 Prefix => New_Occurrence_Of (Var, Loc),
1039 Attribute_Name => Name_Last)))));
1042 Init := New_Occurrence_Of (Var, Loc);
1045 -- An initialization is created for packed conversions as
1046 -- actuals for out parameters to enable Make_Object_Declaration
1047 -- to determine the proper subtype for N_Node. Note that this
1048 -- is wasteful because the extra copying on the call side is
1049 -- not required for such out parameters. ???
1051 elsif Ekind (Formal) = E_Out_Parameter
1052 and then Nkind (Actual) = N_Type_Conversion
1053 and then (Is_Bit_Packed_Array (F_Typ)
1055 Is_Bit_Packed_Array (Etype (Expression (Actual))))
1057 if Conversion_OK (Actual) then
1058 Init := OK_Convert_To (F_Typ, New_Occurrence_Of (Var, Loc));
1060 Init := Convert_To (F_Typ, New_Occurrence_Of (Var, Loc));
1063 elsif Ekind (Formal) = E_In_Parameter then
1065 -- Handle the case in which the actual is a type conversion
1067 if Nkind (Actual) = N_Type_Conversion then
1068 if Conversion_OK (Actual) then
1069 Init := OK_Convert_To (F_Typ, New_Occurrence_Of (Var, Loc));
1071 Init := Convert_To (F_Typ, New_Occurrence_Of (Var, Loc));
1074 Init := New_Occurrence_Of (Var, Loc);
1082 Make_Object_Declaration (Loc,
1083 Defining_Identifier => Temp,
1084 Object_Definition => Indic,
1085 Expression => Init);
1086 Set_Assignment_OK (N_Node);
1087 Insert_Action (N, N_Node);
1089 -- Now, normally the deal here is that we use the defining
1090 -- identifier created by that object declaration. There is
1091 -- one exception to this. In the change of representation case
1092 -- the above declaration will end up looking like:
1094 -- temp : type := identifier;
1096 -- And in this case we might as well use the identifier directly
1097 -- and eliminate the temporary. Note that the analysis of the
1098 -- declaration was not a waste of time in that case, since it is
1099 -- what generated the necessary change of representation code. If
1100 -- the change of representation introduced additional code, as in
1101 -- a fixed-integer conversion, the expression is not an identifier
1102 -- and must be kept.
1105 and then Present (Expression (N_Node))
1106 and then Is_Entity_Name (Expression (N_Node))
1108 Temp := Entity (Expression (N_Node));
1109 Rewrite (N_Node, Make_Null_Statement (Loc));
1112 -- For IN parameter, all we do is to replace the actual
1114 if Ekind (Formal) = E_In_Parameter then
1115 Rewrite (Actual, New_Reference_To (Temp, Loc));
1118 -- Processing for OUT or IN OUT parameter
1121 -- Kill current value indications for the temporary variable we
1122 -- created, since we just passed it as an OUT parameter.
1124 Kill_Current_Values (Temp);
1126 -- If type conversion, use reverse conversion on exit
1128 if Nkind (Actual) = N_Type_Conversion then
1129 if Conversion_OK (Actual) then
1130 Expr := OK_Convert_To (V_Typ, New_Occurrence_Of (Temp, Loc));
1132 Expr := Convert_To (V_Typ, New_Occurrence_Of (Temp, Loc));
1135 Expr := New_Occurrence_Of (Temp, Loc);
1138 Rewrite (Actual, New_Reference_To (Temp, Loc));
1141 -- If the actual is a conversion of a packed reference, it may
1142 -- already have been expanded by Remove_Side_Effects, and the
1143 -- resulting variable is a temporary which does not designate
1144 -- the proper out-parameter, which may not be addressable. In
1145 -- that case, generate an assignment to the original expression
1146 -- (before expansion of the packed reference) so that the proper
1147 -- expansion of assignment to a packed component can take place.
1154 if Is_Renaming_Of_Object (Var)
1155 and then Nkind (Renamed_Object (Var)) = N_Selected_Component
1156 and then Is_Entity_Name (Prefix (Renamed_Object (Var)))
1157 and then Nkind (Original_Node (Prefix (Renamed_Object (Var))))
1158 = N_Indexed_Component
1160 Has_Non_Standard_Rep (Etype (Prefix (Renamed_Object (Var))))
1162 Obj := Renamed_Object (Var);
1164 Make_Selected_Component (Loc,
1166 New_Copy_Tree (Original_Node (Prefix (Obj))),
1167 Selector_Name => New_Copy (Selector_Name (Obj)));
1168 Reset_Analyzed_Flags (Lhs);
1171 Lhs := New_Occurrence_Of (Var, Loc);
1174 Set_Assignment_OK (Lhs);
1176 Append_To (Post_Call,
1177 Make_Assignment_Statement (Loc,
1179 Expression => Expr));
1183 end Add_Call_By_Copy_Code;
1185 ----------------------------------
1186 -- Add_Simple_Call_By_Copy_Code --
1187 ----------------------------------
1189 procedure Add_Simple_Call_By_Copy_Code is
1197 F_Typ : constant Entity_Id := Etype (Formal);
1200 if not Is_Legal_Copy then
1204 -- Use formal type for temp, unless formal type is an unconstrained
1205 -- array, in which case we don't have to worry about bounds checks,
1206 -- and we use the actual type, since that has appropriate bounds.
1208 if Is_Array_Type (F_Typ) and then not Is_Constrained (F_Typ) then
1209 Indic := New_Occurrence_Of (Etype (Actual), Loc);
1211 Indic := New_Occurrence_Of (Etype (Formal), Loc);
1214 -- Prepare to generate code
1216 Reset_Packed_Prefix;
1219 Make_Defining_Identifier (Loc,
1220 Chars => New_Internal_Name ('T'));
1221 Incod := Relocate_Node (Actual);
1222 Outcod := New_Copy_Tree (Incod);
1224 -- Generate declaration of temporary variable, initializing it
1225 -- with the input parameter unless we have an OUT formal or
1226 -- this is an initialization call.
1228 -- If the formal is an out parameter with discriminants, the
1229 -- discriminants must be captured even if the rest of the object
1230 -- is in principle uninitialized, because the discriminants may
1231 -- be read by the called subprogram.
1233 if Ekind (Formal) = E_Out_Parameter then
1236 if Has_Discriminants (Etype (Formal)) then
1237 Indic := New_Occurrence_Of (Etype (Actual), Loc);
1240 elsif Inside_Init_Proc then
1242 -- Could use a comment here to match comment below ???
1244 if Nkind (Actual) /= N_Selected_Component
1246 not Has_Discriminant_Dependent_Constraint
1247 (Entity (Selector_Name (Actual)))
1251 -- Otherwise, keep the component in order to generate the proper
1252 -- actual subtype, that depends on enclosing discriminants.
1260 Make_Object_Declaration (Loc,
1261 Defining_Identifier => Temp,
1262 Object_Definition => Indic,
1263 Expression => Incod);
1268 -- If the call is to initialize a component of a composite type,
1269 -- and the component does not depend on discriminants, use the
1270 -- actual type of the component. This is required in case the
1271 -- component is constrained, because in general the formal of the
1272 -- initialization procedure will be unconstrained. Note that if
1273 -- the component being initialized is constrained by an enclosing
1274 -- discriminant, the presence of the initialization in the
1275 -- declaration will generate an expression for the actual subtype.
1277 Set_No_Initialization (Decl);
1278 Set_Object_Definition (Decl,
1279 New_Occurrence_Of (Etype (Actual), Loc));
1282 Insert_Action (N, Decl);
1284 -- The actual is simply a reference to the temporary
1286 Rewrite (Actual, New_Occurrence_Of (Temp, Loc));
1288 -- Generate copy out if OUT or IN OUT parameter
1290 if Ekind (Formal) /= E_In_Parameter then
1292 Rhs := New_Occurrence_Of (Temp, Loc);
1294 -- Deal with conversion
1296 if Nkind (Lhs) = N_Type_Conversion then
1297 Lhs := Expression (Lhs);
1298 Rhs := Convert_To (Etype (Actual), Rhs);
1301 Append_To (Post_Call,
1302 Make_Assignment_Statement (Loc,
1304 Expression => Rhs));
1305 Set_Assignment_OK (Name (Last (Post_Call)));
1307 end Add_Simple_Call_By_Copy_Code;
1309 ---------------------------
1310 -- Check_Fortran_Logical --
1311 ---------------------------
1313 procedure Check_Fortran_Logical is
1314 Logical : constant Entity_Id := Etype (Formal);
1317 -- Note: this is very incomplete, e.g. it does not handle arrays
1318 -- of logical values. This is really not the right approach at all???)
1321 if Convention (Subp) = Convention_Fortran
1322 and then Root_Type (Etype (Formal)) = Standard_Boolean
1323 and then Ekind (Formal) /= E_In_Parameter
1325 Var := Make_Var (Actual);
1326 Append_To (Post_Call,
1327 Make_Assignment_Statement (Loc,
1328 Name => New_Occurrence_Of (Var, Loc),
1330 Unchecked_Convert_To (
1333 Left_Opnd => New_Occurrence_Of (Var, Loc),
1335 Unchecked_Convert_To (
1337 New_Occurrence_Of (Standard_False, Loc))))));
1339 end Check_Fortran_Logical;
1345 function Is_Legal_Copy return Boolean is
1347 -- An attempt to copy a value of such a type can only occur if
1348 -- representation clauses give the actual a misaligned address.
1350 if Is_By_Reference_Type (Etype (Formal)) then
1352 ("misaligned actual cannot be passed by reference", Actual);
1355 -- For users of Starlet, we assume that the specification of by-
1356 -- reference mechanism is mandatory. This may lead to unaligned
1357 -- objects but at least for DEC legacy code it is known to work.
1358 -- The warning will alert users of this code that a problem may
1361 elsif Mechanism (Formal) = By_Reference
1362 and then Is_Valued_Procedure (Scope (Formal))
1365 ("by_reference actual may be misaligned?", Actual);
1377 function Make_Var (Actual : Node_Id) return Entity_Id is
1381 if Is_Entity_Name (Actual) then
1382 return Entity (Actual);
1386 Make_Defining_Identifier (Loc,
1387 Chars => New_Internal_Name ('T'));
1390 Make_Object_Renaming_Declaration (Loc,
1391 Defining_Identifier => Var,
1393 New_Occurrence_Of (Etype (Actual), Loc),
1394 Name => Relocate_Node (Actual));
1396 Insert_Action (N, N_Node);
1401 -------------------------
1402 -- Reset_Packed_Prefix --
1403 -------------------------
1405 procedure Reset_Packed_Prefix is
1406 Pfx : Node_Id := Actual;
1409 Set_Analyzed (Pfx, False);
1411 not Nkind_In (Pfx, N_Selected_Component, N_Indexed_Component);
1412 Pfx := Prefix (Pfx);
1414 end Reset_Packed_Prefix;
1416 -- Start of processing for Expand_Actuals
1419 Post_Call := New_List;
1421 Formal := First_Formal (Subp);
1422 Actual := First_Actual (N);
1423 while Present (Formal) loop
1424 E_Formal := Etype (Formal);
1426 if Is_Scalar_Type (E_Formal)
1427 or else Nkind (Actual) = N_Slice
1429 Check_Fortran_Logical;
1433 elsif Ekind (Formal) /= E_Out_Parameter then
1435 -- The unusual case of the current instance of a protected type
1436 -- requires special handling. This can only occur in the context
1437 -- of a call within the body of a protected operation.
1439 if Is_Entity_Name (Actual)
1440 and then Ekind (Entity (Actual)) = E_Protected_Type
1441 and then In_Open_Scopes (Entity (Actual))
1443 if Scope (Subp) /= Entity (Actual) then
1444 Error_Msg_N ("operation outside protected type may not "
1445 & "call back its protected operations?", Actual);
1449 Expand_Protected_Object_Reference (N, Entity (Actual)));
1452 -- Ada 2005 (AI-318-02): If the actual parameter is a call to a
1453 -- build-in-place function, then a temporary return object needs
1454 -- to be created and access to it must be passed to the function.
1455 -- Currently we limit such functions to those with inherently
1456 -- limited result subtypes, but eventually we plan to expand the
1457 -- functions that are treated as build-in-place to include other
1458 -- composite result types.
1460 if Ada_Version >= Ada_05
1461 and then Is_Build_In_Place_Function_Call (Actual)
1463 Make_Build_In_Place_Call_In_Anonymous_Context (Actual);
1466 Apply_Constraint_Check (Actual, E_Formal);
1468 -- Out parameter case. No constraint checks on access type
1471 elsif Is_Access_Type (E_Formal) then
1476 elsif Has_Discriminants (Base_Type (E_Formal))
1477 or else Has_Non_Null_Base_Init_Proc (E_Formal)
1479 Apply_Constraint_Check (Actual, E_Formal);
1484 Apply_Constraint_Check (Actual, Base_Type (E_Formal));
1487 -- Processing for IN-OUT and OUT parameters
1489 if Ekind (Formal) /= E_In_Parameter then
1491 -- For type conversions of arrays, apply length/range checks
1493 if Is_Array_Type (E_Formal)
1494 and then Nkind (Actual) = N_Type_Conversion
1496 if Is_Constrained (E_Formal) then
1497 Apply_Length_Check (Expression (Actual), E_Formal);
1499 Apply_Range_Check (Expression (Actual), E_Formal);
1503 -- If argument is a type conversion for a type that is passed
1504 -- by copy, then we must pass the parameter by copy.
1506 if Nkind (Actual) = N_Type_Conversion
1508 (Is_Numeric_Type (E_Formal)
1509 or else Is_Access_Type (E_Formal)
1510 or else Is_Enumeration_Type (E_Formal)
1511 or else Is_Bit_Packed_Array (Etype (Formal))
1512 or else Is_Bit_Packed_Array (Etype (Expression (Actual)))
1514 -- Also pass by copy if change of representation
1516 or else not Same_Representation
1518 Etype (Expression (Actual))))
1520 Add_Call_By_Copy_Code;
1522 -- References to components of bit packed arrays are expanded
1523 -- at this point, rather than at the point of analysis of the
1524 -- actuals, to handle the expansion of the assignment to
1525 -- [in] out parameters.
1527 elsif Is_Ref_To_Bit_Packed_Array (Actual) then
1528 Add_Simple_Call_By_Copy_Code;
1530 -- If a non-scalar actual is possibly bit-aligned, we need a copy
1531 -- because the back-end cannot cope with such objects. In other
1532 -- cases where alignment forces a copy, the back-end generates
1533 -- it properly. It should not be generated unconditionally in the
1534 -- front-end because it does not know precisely the alignment
1535 -- requirements of the target, and makes too conservative an
1536 -- estimate, leading to superfluous copies or spurious errors
1537 -- on by-reference parameters.
1539 elsif Nkind (Actual) = N_Selected_Component
1541 Component_May_Be_Bit_Aligned (Entity (Selector_Name (Actual)))
1542 and then not Represented_As_Scalar (Etype (Formal))
1544 Add_Simple_Call_By_Copy_Code;
1546 -- References to slices of bit packed arrays are expanded
1548 elsif Is_Ref_To_Bit_Packed_Slice (Actual) then
1549 Add_Call_By_Copy_Code;
1551 -- References to possibly unaligned slices of arrays are expanded
1553 elsif Is_Possibly_Unaligned_Slice (Actual) then
1554 Add_Call_By_Copy_Code;
1556 -- Deal with access types where the actual subtype and the
1557 -- formal subtype are not the same, requiring a check.
1559 -- It is necessary to exclude tagged types because of "downward
1560 -- conversion" errors.
1562 elsif Is_Access_Type (E_Formal)
1563 and then not Same_Type (E_Formal, Etype (Actual))
1564 and then not Is_Tagged_Type (Designated_Type (E_Formal))
1566 Add_Call_By_Copy_Code;
1568 -- If the actual is not a scalar and is marked for volatile
1569 -- treatment, whereas the formal is not volatile, then pass
1570 -- by copy unless it is a by-reference type.
1572 elsif Is_Entity_Name (Actual)
1573 and then Treat_As_Volatile (Entity (Actual))
1574 and then not Is_By_Reference_Type (Etype (Actual))
1575 and then not Is_Scalar_Type (Etype (Entity (Actual)))
1576 and then not Treat_As_Volatile (E_Formal)
1578 Add_Call_By_Copy_Code;
1580 elsif Nkind (Actual) = N_Indexed_Component
1581 and then Is_Entity_Name (Prefix (Actual))
1582 and then Has_Volatile_Components (Entity (Prefix (Actual)))
1584 Add_Call_By_Copy_Code;
1587 -- Processing for IN parameters
1590 -- For IN parameters is in the packed array case, we expand an
1591 -- indexed component (the circuit in Exp_Ch4 deliberately left
1592 -- indexed components appearing as actuals untouched, so that
1593 -- the special processing above for the OUT and IN OUT cases
1594 -- could be performed. We could make the test in Exp_Ch4 more
1595 -- complex and have it detect the parameter mode, but it is
1596 -- easier simply to handle all cases here.)
1598 if Nkind (Actual) = N_Indexed_Component
1599 and then Is_Packed (Etype (Prefix (Actual)))
1601 Reset_Packed_Prefix;
1602 Expand_Packed_Element_Reference (Actual);
1604 -- If we have a reference to a bit packed array, we copy it,
1605 -- since the actual must be byte aligned.
1607 -- Is this really necessary in all cases???
1609 elsif Is_Ref_To_Bit_Packed_Array (Actual) then
1610 Add_Simple_Call_By_Copy_Code;
1612 -- If a non-scalar actual is possibly unaligned, we need a copy
1614 elsif Is_Possibly_Unaligned_Object (Actual)
1615 and then not Represented_As_Scalar (Etype (Formal))
1617 Add_Simple_Call_By_Copy_Code;
1619 -- Similarly, we have to expand slices of packed arrays here
1620 -- because the result must be byte aligned.
1622 elsif Is_Ref_To_Bit_Packed_Slice (Actual) then
1623 Add_Call_By_Copy_Code;
1625 -- Only processing remaining is to pass by copy if this is a
1626 -- reference to a possibly unaligned slice, since the caller
1627 -- expects an appropriately aligned argument.
1629 elsif Is_Possibly_Unaligned_Slice (Actual) then
1630 Add_Call_By_Copy_Code;
1634 Next_Formal (Formal);
1635 Next_Actual (Actual);
1638 -- Find right place to put post call stuff if it is present
1640 if not Is_Empty_List (Post_Call) then
1642 -- If call is not a list member, it must be the triggering statement
1643 -- of a triggering alternative or an entry call alternative, and we
1644 -- can add the post call stuff to the corresponding statement list.
1646 if not Is_List_Member (N) then
1648 P : constant Node_Id := Parent (N);
1651 pragma Assert (Nkind_In (P, N_Triggering_Alternative,
1652 N_Entry_Call_Alternative));
1654 if Is_Non_Empty_List (Statements (P)) then
1655 Insert_List_Before_And_Analyze
1656 (First (Statements (P)), Post_Call);
1658 Set_Statements (P, Post_Call);
1662 -- Otherwise, normal case where N is in a statement sequence,
1663 -- just put the post-call stuff after the call statement.
1666 Insert_Actions_After (N, Post_Call);
1670 -- The call node itself is re-analyzed in Expand_Call
1678 -- This procedure handles expansion of function calls and procedure call
1679 -- statements (i.e. it serves as the body for Expand_N_Function_Call and
1680 -- Expand_N_Procedure_Call_Statement). Processing for calls includes:
1682 -- Replace call to Raise_Exception by Raise_Exception_Always if possible
1683 -- Provide values of actuals for all formals in Extra_Formals list
1684 -- Replace "call" to enumeration literal function by literal itself
1685 -- Rewrite call to predefined operator as operator
1686 -- Replace actuals to in-out parameters that are numeric conversions,
1687 -- with explicit assignment to temporaries before and after the call.
1688 -- Remove optional actuals if First_Optional_Parameter specified.
1690 -- Note that the list of actuals has been filled with default expressions
1691 -- during semantic analysis of the call. Only the extra actuals required
1692 -- for the 'Constrained attribute and for accessibility checks are added
1695 procedure Expand_Call (N : Node_Id) is
1696 Loc : constant Source_Ptr := Sloc (N);
1697 Extra_Actuals : List_Id := No_List;
1698 Prev : Node_Id := Empty;
1700 procedure Add_Actual_Parameter (Insert_Param : Node_Id);
1701 -- Adds one entry to the end of the actual parameter list. Used for
1702 -- default parameters and for extra actuals (for Extra_Formals). The
1703 -- argument is an N_Parameter_Association node.
1705 procedure Add_Extra_Actual (Expr : Node_Id; EF : Entity_Id);
1706 -- Adds an extra actual to the list of extra actuals. Expr is the
1707 -- expression for the value of the actual, EF is the entity for the
1710 function Inherited_From_Formal (S : Entity_Id) return Entity_Id;
1711 -- Within an instance, a type derived from a non-tagged formal derived
1712 -- type inherits from the original parent, not from the actual. The
1713 -- current derivation mechanism has the derived type inherit from the
1714 -- actual, which is only correct outside of the instance. If the
1715 -- subprogram is inherited, we test for this particular case through a
1716 -- convoluted tree traversal before setting the proper subprogram to be
1719 --------------------------
1720 -- Add_Actual_Parameter --
1721 --------------------------
1723 procedure Add_Actual_Parameter (Insert_Param : Node_Id) is
1724 Actual_Expr : constant Node_Id :=
1725 Explicit_Actual_Parameter (Insert_Param);
1728 -- Case of insertion is first named actual
1730 if No (Prev) or else
1731 Nkind (Parent (Prev)) /= N_Parameter_Association
1733 Set_Next_Named_Actual (Insert_Param, First_Named_Actual (N));
1734 Set_First_Named_Actual (N, Actual_Expr);
1737 if No (Parameter_Associations (N)) then
1738 Set_Parameter_Associations (N, New_List);
1739 Append (Insert_Param, Parameter_Associations (N));
1742 Insert_After (Prev, Insert_Param);
1745 -- Case of insertion is not first named actual
1748 Set_Next_Named_Actual
1749 (Insert_Param, Next_Named_Actual (Parent (Prev)));
1750 Set_Next_Named_Actual (Parent (Prev), Actual_Expr);
1751 Append (Insert_Param, Parameter_Associations (N));
1754 Prev := Actual_Expr;
1755 end Add_Actual_Parameter;
1757 ----------------------
1758 -- Add_Extra_Actual --
1759 ----------------------
1761 procedure Add_Extra_Actual (Expr : Node_Id; EF : Entity_Id) is
1762 Loc : constant Source_Ptr := Sloc (Expr);
1765 if Extra_Actuals = No_List then
1766 Extra_Actuals := New_List;
1767 Set_Parent (Extra_Actuals, N);
1770 Append_To (Extra_Actuals,
1771 Make_Parameter_Association (Loc,
1772 Explicit_Actual_Parameter => Expr,
1774 Make_Identifier (Loc, Chars (EF))));
1776 Analyze_And_Resolve (Expr, Etype (EF));
1777 end Add_Extra_Actual;
1779 ---------------------------
1780 -- Inherited_From_Formal --
1781 ---------------------------
1783 function Inherited_From_Formal (S : Entity_Id) return Entity_Id is
1785 Gen_Par : Entity_Id;
1786 Gen_Prim : Elist_Id;
1791 -- If the operation is inherited, it is attached to the corresponding
1792 -- type derivation. If the parent in the derivation is a generic
1793 -- actual, it is a subtype of the actual, and we have to recover the
1794 -- original derived type declaration to find the proper parent.
1796 if Nkind (Parent (S)) /= N_Full_Type_Declaration
1797 or else not Is_Derived_Type (Defining_Identifier (Parent (S)))
1798 or else Nkind (Type_Definition (Original_Node (Parent (S)))) /=
1799 N_Derived_Type_Definition
1800 or else not In_Instance
1807 (Type_Definition (Original_Node (Parent (S)))));
1809 if Nkind (Indic) = N_Subtype_Indication then
1810 Par := Entity (Subtype_Mark (Indic));
1812 Par := Entity (Indic);
1816 if not Is_Generic_Actual_Type (Par)
1817 or else Is_Tagged_Type (Par)
1818 or else Nkind (Parent (Par)) /= N_Subtype_Declaration
1819 or else not In_Open_Scopes (Scope (Par))
1824 Gen_Par := Generic_Parent_Type (Parent (Par));
1827 -- If the actual has no generic parent type, the formal is not
1828 -- a formal derived type, so nothing to inherit.
1830 if No (Gen_Par) then
1834 -- If the generic parent type is still the generic type, this is a
1835 -- private formal, not a derived formal, and there are no operations
1836 -- inherited from the formal.
1838 if Nkind (Parent (Gen_Par)) = N_Formal_Type_Declaration then
1842 Gen_Prim := Collect_Primitive_Operations (Gen_Par);
1844 Elmt := First_Elmt (Gen_Prim);
1845 while Present (Elmt) loop
1846 if Chars (Node (Elmt)) = Chars (S) then
1852 F1 := First_Formal (S);
1853 F2 := First_Formal (Node (Elmt));
1855 and then Present (F2)
1857 if Etype (F1) = Etype (F2)
1858 or else Etype (F2) = Gen_Par
1864 exit; -- not the right subprogram
1876 raise Program_Error;
1877 end Inherited_From_Formal;
1881 Remote : constant Boolean := Is_Remote_Call (N);
1884 Orig_Subp : Entity_Id := Empty;
1885 Param_Count : Natural := 0;
1886 Parent_Formal : Entity_Id;
1887 Parent_Subp : Entity_Id;
1891 Prev_Orig : Node_Id;
1892 -- Original node for an actual, which may have been rewritten. If the
1893 -- actual is a function call that has been transformed from a selected
1894 -- component, the original node is unanalyzed. Otherwise, it carries
1895 -- semantic information used to generate additional actuals.
1897 CW_Interface_Formals_Present : Boolean := False;
1899 -- Start of processing for Expand_Call
1902 -- Ignore if previous error
1904 if Nkind (N) in N_Has_Etype and then Etype (N) = Any_Type then
1908 -- Call using access to subprogram with explicit dereference
1910 if Nkind (Name (N)) = N_Explicit_Dereference then
1911 Subp := Etype (Name (N));
1912 Parent_Subp := Empty;
1914 -- Case of call to simple entry, where the Name is a selected component
1915 -- whose prefix is the task, and whose selector name is the entry name
1917 elsif Nkind (Name (N)) = N_Selected_Component then
1918 Subp := Entity (Selector_Name (Name (N)));
1919 Parent_Subp := Empty;
1921 -- Case of call to member of entry family, where Name is an indexed
1922 -- component, with the prefix being a selected component giving the
1923 -- task and entry family name, and the index being the entry index.
1925 elsif Nkind (Name (N)) = N_Indexed_Component then
1926 Subp := Entity (Selector_Name (Prefix (Name (N))));
1927 Parent_Subp := Empty;
1932 Subp := Entity (Name (N));
1933 Parent_Subp := Alias (Subp);
1935 -- Replace call to Raise_Exception by call to Raise_Exception_Always
1936 -- if we can tell that the first parameter cannot possibly be null.
1937 -- This improves efficiency by avoiding a run-time test.
1939 -- We do not do this if Raise_Exception_Always does not exist, which
1940 -- can happen in configurable run time profiles which provide only a
1943 if Is_RTE (Subp, RE_Raise_Exception)
1944 and then RTE_Available (RE_Raise_Exception_Always)
1947 FA : constant Node_Id := Original_Node (First_Actual (N));
1950 -- The case we catch is where the first argument is obtained
1951 -- using the Identity attribute (which must always be
1954 if Nkind (FA) = N_Attribute_Reference
1955 and then Attribute_Name (FA) = Name_Identity
1957 Subp := RTE (RE_Raise_Exception_Always);
1958 Set_Name (N, New_Occurrence_Of (Subp, Loc));
1963 if Ekind (Subp) = E_Entry then
1964 Parent_Subp := Empty;
1968 -- Ada 2005 (AI-345): We have a procedure call as a triggering
1969 -- alternative in an asynchronous select or as an entry call in
1970 -- a conditional or timed select. Check whether the procedure call
1971 -- is a renaming of an entry and rewrite it as an entry call.
1973 if Ada_Version >= Ada_05
1974 and then Nkind (N) = N_Procedure_Call_Statement
1976 ((Nkind (Parent (N)) = N_Triggering_Alternative
1977 and then Triggering_Statement (Parent (N)) = N)
1979 (Nkind (Parent (N)) = N_Entry_Call_Alternative
1980 and then Entry_Call_Statement (Parent (N)) = N))
1984 Ren_Root : Entity_Id := Subp;
1987 -- This may be a chain of renamings, find the root
1989 if Present (Alias (Ren_Root)) then
1990 Ren_Root := Alias (Ren_Root);
1993 if Present (Original_Node (Parent (Parent (Ren_Root)))) then
1994 Ren_Decl := Original_Node (Parent (Parent (Ren_Root)));
1996 if Nkind (Ren_Decl) = N_Subprogram_Renaming_Declaration then
1998 Make_Entry_Call_Statement (Loc,
2000 New_Copy_Tree (Name (Ren_Decl)),
2001 Parameter_Associations =>
2002 New_Copy_List_Tree (Parameter_Associations (N))));
2010 -- First step, compute extra actuals, corresponding to any
2011 -- Extra_Formals present. Note that we do not access Extra_Formals
2012 -- directly, instead we simply note the presence of the extra
2013 -- formals as we process the regular formals and collect the
2014 -- corresponding actuals in Extra_Actuals.
2016 -- We also generate any required range checks for actuals as we go
2017 -- through the loop, since this is a convenient place to do this.
2019 Formal := First_Formal (Subp);
2020 Actual := First_Actual (N);
2022 while Present (Formal) loop
2024 -- Generate range check if required (not activated yet ???)
2026 -- if Do_Range_Check (Actual) then
2027 -- Set_Do_Range_Check (Actual, False);
2028 -- Generate_Range_Check
2029 -- (Actual, Etype (Formal), CE_Range_Check_Failed);
2032 -- Prepare to examine current entry
2035 Prev_Orig := Original_Node (Prev);
2037 -- The original actual may have been a call written in prefix
2038 -- form, and rewritten before analysis.
2040 if not Analyzed (Prev_Orig)
2041 and then Nkind_In (Actual, N_Function_Call, N_Identifier)
2046 -- Ada 2005 (AI-251): Check if any formal is a class-wide interface
2047 -- to expand it in a further round.
2049 CW_Interface_Formals_Present :=
2050 CW_Interface_Formals_Present
2052 (Ekind (Etype (Formal)) = E_Class_Wide_Type
2053 and then Is_Interface (Etype (Etype (Formal))))
2055 (Ekind (Etype (Formal)) = E_Anonymous_Access_Type
2056 and then Is_Interface (Directly_Designated_Type
2057 (Etype (Etype (Formal)))));
2059 -- Create possible extra actual for constrained case. Usually, the
2060 -- extra actual is of the form actual'constrained, but since this
2061 -- attribute is only available for unconstrained records, TRUE is
2062 -- expanded if the type of the formal happens to be constrained (for
2063 -- instance when this procedure is inherited from an unconstrained
2064 -- record to a constrained one) or if the actual has no discriminant
2065 -- (its type is constrained). An exception to this is the case of a
2066 -- private type without discriminants. In this case we pass FALSE
2067 -- because the object has underlying discriminants with defaults.
2069 if Present (Extra_Constrained (Formal)) then
2070 if Ekind (Etype (Prev)) in Private_Kind
2071 and then not Has_Discriminants (Base_Type (Etype (Prev)))
2074 New_Occurrence_Of (Standard_False, Loc),
2075 Extra_Constrained (Formal));
2077 elsif Is_Constrained (Etype (Formal))
2078 or else not Has_Discriminants (Etype (Prev))
2081 New_Occurrence_Of (Standard_True, Loc),
2082 Extra_Constrained (Formal));
2084 -- Do not produce extra actuals for Unchecked_Union parameters.
2085 -- Jump directly to the end of the loop.
2087 elsif Is_Unchecked_Union (Base_Type (Etype (Actual))) then
2088 goto Skip_Extra_Actual_Generation;
2091 -- If the actual is a type conversion, then the constrained
2092 -- test applies to the actual, not the target type.
2098 -- Test for unchecked conversions as well, which can occur
2099 -- as out parameter actuals on calls to stream procedures.
2102 while Nkind_In (Act_Prev, N_Type_Conversion,
2103 N_Unchecked_Type_Conversion)
2105 Act_Prev := Expression (Act_Prev);
2108 -- If the expression is a conversion of a dereference,
2109 -- this is internally generated code that manipulates
2110 -- addresses, e.g. when building interface tables. No
2111 -- check should occur in this case, and the discriminated
2112 -- object is not directly a hand.
2114 if not Comes_From_Source (Actual)
2115 and then Nkind (Actual) = N_Unchecked_Type_Conversion
2116 and then Nkind (Act_Prev) = N_Explicit_Dereference
2119 (New_Occurrence_Of (Standard_False, Loc),
2120 Extra_Constrained (Formal));
2124 (Make_Attribute_Reference (Sloc (Prev),
2126 Duplicate_Subexpr_No_Checks
2127 (Act_Prev, Name_Req => True),
2128 Attribute_Name => Name_Constrained),
2129 Extra_Constrained (Formal));
2135 -- Create possible extra actual for accessibility level
2137 if Present (Extra_Accessibility (Formal)) then
2139 -- Ada 2005 (AI-252): If the actual was rewritten as an Access
2140 -- attribute, then the original actual may be an aliased object
2141 -- occurring as the prefix in a call using "Object.Operation"
2142 -- notation. In that case we must pass the level of the object,
2143 -- so Prev_Orig is reset to Prev and the attribute will be
2144 -- processed by the code for Access attributes further below.
2146 if Prev_Orig /= Prev
2147 and then Nkind (Prev) = N_Attribute_Reference
2149 Get_Attribute_Id (Attribute_Name (Prev)) = Attribute_Access
2150 and then Is_Aliased_View (Prev_Orig)
2155 -- Ada 2005 (AI-251): Thunks must propagate the extra actuals
2156 -- of accessibility levels.
2158 if Ekind (Current_Scope) in Subprogram_Kind
2159 and then Is_Thunk (Current_Scope)
2162 Parm_Ent : Entity_Id;
2165 if Is_Controlling_Actual (Actual) then
2167 -- Find the corresponding actual of the thunk
2169 Parm_Ent := First_Entity (Current_Scope);
2170 for J in 2 .. Param_Count loop
2171 Next_Entity (Parm_Ent);
2174 else pragma Assert (Is_Entity_Name (Actual));
2175 Parm_Ent := Entity (Actual);
2179 (New_Occurrence_Of (Extra_Accessibility (Parm_Ent), Loc),
2180 Extra_Accessibility (Formal));
2183 elsif Is_Entity_Name (Prev_Orig) then
2185 -- When passing an access parameter, or a renaming of an access
2186 -- parameter, as the actual to another access parameter we need
2187 -- to pass along the actual's own access level parameter. This
2188 -- is done if we are within the scope of the formal access
2189 -- parameter (if this is an inlined body the extra formal is
2192 if (Is_Formal (Entity (Prev_Orig))
2194 (Present (Renamed_Object (Entity (Prev_Orig)))
2196 Is_Entity_Name (Renamed_Object (Entity (Prev_Orig)))
2199 (Entity (Renamed_Object (Entity (Prev_Orig))))))
2200 and then Ekind (Etype (Prev_Orig)) = E_Anonymous_Access_Type
2201 and then In_Open_Scopes (Scope (Entity (Prev_Orig)))
2204 Parm_Ent : constant Entity_Id := Param_Entity (Prev_Orig);
2207 pragma Assert (Present (Parm_Ent));
2209 if Present (Extra_Accessibility (Parm_Ent)) then
2212 (Extra_Accessibility (Parm_Ent), Loc),
2213 Extra_Accessibility (Formal));
2215 -- If the actual access parameter does not have an
2216 -- associated extra formal providing its scope level,
2217 -- then treat the actual as having library-level
2222 (Make_Integer_Literal (Loc,
2223 Intval => Scope_Depth (Standard_Standard)),
2224 Extra_Accessibility (Formal));
2228 -- The actual is a normal access value, so just pass the level
2229 -- of the actual's access type.
2233 (Make_Integer_Literal (Loc,
2234 Intval => Type_Access_Level (Etype (Prev_Orig))),
2235 Extra_Accessibility (Formal));
2238 -- All cases other than thunks
2241 case Nkind (Prev_Orig) is
2243 when N_Attribute_Reference =>
2244 case Get_Attribute_Id (Attribute_Name (Prev_Orig)) is
2246 -- For X'Access, pass on the level of the prefix X
2248 when Attribute_Access =>
2250 Make_Integer_Literal (Loc,
2252 Object_Access_Level (Prefix (Prev_Orig))),
2253 Extra_Accessibility (Formal));
2255 -- Treat the unchecked attributes as library-level
2257 when Attribute_Unchecked_Access |
2258 Attribute_Unrestricted_Access =>
2260 Make_Integer_Literal (Loc,
2261 Intval => Scope_Depth (Standard_Standard)),
2262 Extra_Accessibility (Formal));
2264 -- No other cases of attributes returning access
2265 -- values that can be passed to access parameters
2268 raise Program_Error;
2272 -- For allocators we pass the level of the execution of
2273 -- the called subprogram, which is one greater than the
2274 -- current scope level.
2278 Make_Integer_Literal (Loc,
2279 Scope_Depth (Current_Scope) + 1),
2280 Extra_Accessibility (Formal));
2282 -- For other cases we simply pass the level of the
2283 -- actual's access type.
2287 Make_Integer_Literal (Loc,
2288 Intval => Type_Access_Level (Etype (Prev_Orig))),
2289 Extra_Accessibility (Formal));
2295 -- Perform the check of 4.6(49) that prevents a null value from being
2296 -- passed as an actual to an access parameter. Note that the check is
2297 -- elided in the common cases of passing an access attribute or
2298 -- access parameter as an actual. Also, we currently don't enforce
2299 -- this check for expander-generated actuals and when -gnatdj is set.
2301 if Ada_Version >= Ada_05 then
2303 -- Ada 2005 (AI-231): Check null-excluding access types
2305 if Is_Access_Type (Etype (Formal))
2306 and then Can_Never_Be_Null (Etype (Formal))
2307 and then Nkind (Prev) /= N_Raise_Constraint_Error
2308 and then (Known_Null (Prev)
2309 or else not Can_Never_Be_Null (Etype (Prev)))
2311 Install_Null_Excluding_Check (Prev);
2314 -- Ada_Version < Ada_05
2317 if Ekind (Etype (Formal)) /= E_Anonymous_Access_Type
2318 or else Access_Checks_Suppressed (Subp)
2322 elsif Debug_Flag_J then
2325 elsif not Comes_From_Source (Prev) then
2328 elsif Is_Entity_Name (Prev)
2329 and then Ekind (Etype (Prev)) = E_Anonymous_Access_Type
2333 elsif Nkind_In (Prev, N_Allocator, N_Attribute_Reference) then
2336 -- Suppress null checks when passing to access parameters of Java
2337 -- and CIL subprograms. (Should this be done for other foreign
2338 -- conventions as well ???)
2340 elsif Convention (Subp) = Convention_Java
2341 or else Convention (Subp) = Convention_CIL
2346 Install_Null_Excluding_Check (Prev);
2350 -- Perform appropriate validity checks on parameters that
2353 if Validity_Checks_On then
2354 if (Ekind (Formal) = E_In_Parameter
2355 and then Validity_Check_In_Params)
2357 (Ekind (Formal) = E_In_Out_Parameter
2358 and then Validity_Check_In_Out_Params)
2360 -- If the actual is an indexed component of a packed type (or
2361 -- is an indexed or selected component whose prefix recursively
2362 -- meets this condition), it has not been expanded yet. It will
2363 -- be copied in the validity code that follows, and has to be
2364 -- expanded appropriately, so reanalyze it.
2366 -- What we do is just to unset analyzed bits on prefixes till
2367 -- we reach something that does not have a prefix.
2374 while Nkind_In (Nod, N_Indexed_Component,
2375 N_Selected_Component)
2377 Set_Analyzed (Nod, False);
2378 Nod := Prefix (Nod);
2382 Ensure_Valid (Actual);
2386 -- For IN OUT and OUT parameters, ensure that subscripts are valid
2387 -- since this is a left side reference. We only do this for calls
2388 -- from the source program since we assume that compiler generated
2389 -- calls explicitly generate any required checks. We also need it
2390 -- only if we are doing standard validity checks, since clearly it
2391 -- is not needed if validity checks are off, and in subscript
2392 -- validity checking mode, all indexed components are checked with
2393 -- a call directly from Expand_N_Indexed_Component.
2395 if Comes_From_Source (N)
2396 and then Ekind (Formal) /= E_In_Parameter
2397 and then Validity_Checks_On
2398 and then Validity_Check_Default
2399 and then not Validity_Check_Subscripts
2401 Check_Valid_Lvalue_Subscripts (Actual);
2404 -- Mark any scalar OUT parameter that is a simple variable as no
2405 -- longer known to be valid (unless the type is always valid). This
2406 -- reflects the fact that if an OUT parameter is never set in a
2407 -- procedure, then it can become invalid on the procedure return.
2409 if Ekind (Formal) = E_Out_Parameter
2410 and then Is_Entity_Name (Actual)
2411 and then Ekind (Entity (Actual)) = E_Variable
2412 and then not Is_Known_Valid (Etype (Actual))
2414 Set_Is_Known_Valid (Entity (Actual), False);
2417 -- For an OUT or IN OUT parameter, if the actual is an entity, then
2418 -- clear current values, since they can be clobbered. We are probably
2419 -- doing this in more places than we need to, but better safe than
2420 -- sorry when it comes to retaining bad current values!
2422 if Ekind (Formal) /= E_In_Parameter
2423 and then Is_Entity_Name (Actual)
2424 and then Present (Entity (Actual))
2427 Ent : constant Entity_Id := Entity (Actual);
2431 -- For an OUT or IN OUT parameter that is an assignable entity,
2432 -- we do not want to clobber the Last_Assignment field, since
2433 -- if it is set, it was precisely because it is indeed an OUT
2434 -- or IN OUT parameter!
2436 if (Ekind (Formal) = E_Out_Parameter
2438 Ekind (Formal) = E_In_Out_Parameter)
2439 and then Is_Assignable (Ent)
2441 Sav := Last_Assignment (Ent);
2442 Kill_Current_Values (Ent);
2443 Set_Last_Assignment (Ent, Sav);
2445 -- For all other cases, just kill the current values
2448 Kill_Current_Values (Ent);
2453 -- If the formal is class wide and the actual is an aggregate, force
2454 -- evaluation so that the back end who does not know about class-wide
2455 -- type, does not generate a temporary of the wrong size.
2457 if not Is_Class_Wide_Type (Etype (Formal)) then
2460 elsif Nkind (Actual) = N_Aggregate
2461 or else (Nkind (Actual) = N_Qualified_Expression
2462 and then Nkind (Expression (Actual)) = N_Aggregate)
2464 Force_Evaluation (Actual);
2467 -- In a remote call, if the formal is of a class-wide type, check
2468 -- that the actual meets the requirements described in E.4(18).
2470 if Remote and then Is_Class_Wide_Type (Etype (Formal)) then
2471 Insert_Action (Actual,
2472 Make_Transportable_Check (Loc,
2473 Duplicate_Subexpr_Move_Checks (Actual)));
2476 -- This label is required when skipping extra actual generation for
2477 -- Unchecked_Union parameters.
2479 <<Skip_Extra_Actual_Generation>>
2481 Param_Count := Param_Count + 1;
2482 Next_Actual (Actual);
2483 Next_Formal (Formal);
2486 -- If we are expanding a rhs of an assignment we need to check if tag
2487 -- propagation is needed. You might expect this processing to be in
2488 -- Analyze_Assignment but has to be done earlier (bottom-up) because the
2489 -- assignment might be transformed to a declaration for an unconstrained
2490 -- value if the expression is classwide.
2492 if Nkind (N) = N_Function_Call
2493 and then Is_Tag_Indeterminate (N)
2494 and then Is_Entity_Name (Name (N))
2497 Ass : Node_Id := Empty;
2500 if Nkind (Parent (N)) = N_Assignment_Statement then
2503 elsif Nkind (Parent (N)) = N_Qualified_Expression
2504 and then Nkind (Parent (Parent (N))) = N_Assignment_Statement
2506 Ass := Parent (Parent (N));
2508 elsif Nkind (Parent (N)) = N_Explicit_Dereference
2509 and then Nkind (Parent (Parent (N))) = N_Assignment_Statement
2511 Ass := Parent (Parent (N));
2515 and then Is_Class_Wide_Type (Etype (Name (Ass)))
2517 if Is_Access_Type (Etype (N)) then
2518 if Designated_Type (Etype (N)) /=
2519 Root_Type (Etype (Name (Ass)))
2522 ("tag-indeterminate expression "
2523 & " must have designated type& (RM 5.2 (6))",
2524 N, Root_Type (Etype (Name (Ass))));
2526 Propagate_Tag (Name (Ass), N);
2529 elsif Etype (N) /= Root_Type (Etype (Name (Ass))) then
2531 ("tag-indeterminate expression must have type&"
2532 & "(RM 5.2 (6))", N, Root_Type (Etype (Name (Ass))));
2535 Propagate_Tag (Name (Ass), N);
2538 -- The call will be rewritten as a dispatching call, and
2539 -- expanded as such.
2546 -- Ada 2005 (AI-251): If some formal is a class-wide interface, expand
2547 -- it to point to the correct secondary virtual table
2549 if Nkind_In (N, N_Function_Call, N_Procedure_Call_Statement)
2550 and then CW_Interface_Formals_Present
2552 Expand_Interface_Actuals (N);
2555 -- Deals with Dispatch_Call if we still have a call, before expanding
2556 -- extra actuals since this will be done on the re-analysis of the
2557 -- dispatching call. Note that we do not try to shorten the actual
2558 -- list for a dispatching call, it would not make sense to do so.
2559 -- Expansion of dispatching calls is suppressed when VM_Target, because
2560 -- the VM back-ends directly handle the generation of dispatching
2561 -- calls and would have to undo any expansion to an indirect call.
2563 if Nkind_In (N, N_Function_Call, N_Procedure_Call_Statement)
2564 and then Present (Controlling_Argument (N))
2566 if VM_Target = No_VM then
2567 Expand_Dispatching_Call (N);
2569 -- The following return is worrisome. Is it really OK to
2570 -- skip all remaining processing in this procedure ???
2574 -- Expansion of a dispatching call results in an indirect call, which
2575 -- in turn causes current values to be killed (see Resolve_Call), so
2576 -- on VM targets we do the call here to ensure consistent warnings
2577 -- between VM and non-VM targets.
2580 Kill_Current_Values;
2584 -- Similarly, expand calls to RCI subprograms on which pragma
2585 -- All_Calls_Remote applies. The rewriting will be reanalyzed
2586 -- later. Do this only when the call comes from source since we do
2587 -- not want such a rewriting to occur in expanded code.
2589 if Is_All_Remote_Call (N) then
2590 Expand_All_Calls_Remote_Subprogram_Call (N);
2592 -- Similarly, do not add extra actuals for an entry call whose entity
2593 -- is a protected procedure, or for an internal protected subprogram
2594 -- call, because it will be rewritten as a protected subprogram call
2595 -- and reanalyzed (see Expand_Protected_Subprogram_Call).
2597 elsif Is_Protected_Type (Scope (Subp))
2598 and then (Ekind (Subp) = E_Procedure
2599 or else Ekind (Subp) = E_Function)
2603 -- During that loop we gathered the extra actuals (the ones that
2604 -- correspond to Extra_Formals), so now they can be appended.
2607 while Is_Non_Empty_List (Extra_Actuals) loop
2608 Add_Actual_Parameter (Remove_Head (Extra_Actuals));
2612 -- At this point we have all the actuals, so this is the point at
2613 -- which the various expansion activities for actuals is carried out.
2615 Expand_Actuals (N, Subp);
2617 -- If the subprogram is a renaming, or if it is inherited, replace it
2618 -- in the call with the name of the actual subprogram being called.
2619 -- If this is a dispatching call, the run-time decides what to call.
2620 -- The Alias attribute does not apply to entries.
2622 if Nkind (N) /= N_Entry_Call_Statement
2623 and then No (Controlling_Argument (N))
2624 and then Present (Parent_Subp)
2626 if Present (Inherited_From_Formal (Subp)) then
2627 Parent_Subp := Inherited_From_Formal (Subp);
2629 while Present (Alias (Parent_Subp)) loop
2630 Parent_Subp := Alias (Parent_Subp);
2634 -- The below setting of Entity is suspect, see F109-018 discussion???
2636 Set_Entity (Name (N), Parent_Subp);
2638 if Is_Abstract_Subprogram (Parent_Subp)
2639 and then not In_Instance
2642 ("cannot call abstract subprogram &!", Name (N), Parent_Subp);
2645 -- Inspect all formals of derived subprogram Subp. Compare parameter
2646 -- types with the parent subprogram and check whether an actual may
2647 -- need a type conversion to the corresponding formal of the parent
2650 -- Not clear whether intrinsic subprograms need such conversions. ???
2652 if not Is_Intrinsic_Subprogram (Parent_Subp)
2653 or else Is_Generic_Instance (Parent_Subp)
2656 procedure Convert (Act : Node_Id; Typ : Entity_Id);
2657 -- Rewrite node Act as a type conversion of Act to Typ. Analyze
2658 -- and resolve the newly generated construct.
2664 procedure Convert (Act : Node_Id; Typ : Entity_Id) is
2666 Rewrite (Act, OK_Convert_To (Typ, Relocate_Node (Act)));
2673 Actual_Typ : Entity_Id;
2674 Formal_Typ : Entity_Id;
2675 Parent_Typ : Entity_Id;
2678 Actual := First_Actual (N);
2679 Formal := First_Formal (Subp);
2680 Parent_Formal := First_Formal (Parent_Subp);
2681 while Present (Formal) loop
2682 Actual_Typ := Etype (Actual);
2683 Formal_Typ := Etype (Formal);
2684 Parent_Typ := Etype (Parent_Formal);
2686 -- For an IN parameter of a scalar type, the parent formal
2687 -- type and derived formal type differ or the parent formal
2688 -- type and actual type do not match statically.
2690 if Is_Scalar_Type (Formal_Typ)
2691 and then Ekind (Formal) = E_In_Parameter
2692 and then Formal_Typ /= Parent_Typ
2694 not Subtypes_Statically_Match (Parent_Typ, Actual_Typ)
2695 and then not Raises_Constraint_Error (Actual)
2697 Convert (Actual, Parent_Typ);
2698 Enable_Range_Check (Actual);
2700 -- For access types, the parent formal type and actual type
2703 elsif Is_Access_Type (Formal_Typ)
2704 and then Base_Type (Parent_Typ) /= Base_Type (Actual_Typ)
2706 if Ekind (Formal) /= E_In_Parameter then
2707 Convert (Actual, Parent_Typ);
2709 elsif Ekind (Parent_Typ) = E_Anonymous_Access_Type
2710 and then Designated_Type (Parent_Typ) /=
2711 Designated_Type (Actual_Typ)
2712 and then not Is_Controlling_Formal (Formal)
2714 -- This unchecked conversion is not necessary unless
2715 -- inlining is enabled, because in that case the type
2716 -- mismatch may become visible in the body about to be
2720 Unchecked_Convert_To (Parent_Typ,
2721 Relocate_Node (Actual)));
2724 Resolve (Actual, Parent_Typ);
2727 -- For array and record types, the parent formal type and
2728 -- derived formal type have different sizes or pragma Pack
2731 elsif ((Is_Array_Type (Formal_Typ)
2732 and then Is_Array_Type (Parent_Typ))
2734 (Is_Record_Type (Formal_Typ)
2735 and then Is_Record_Type (Parent_Typ)))
2737 (Esize (Formal_Typ) /= Esize (Parent_Typ)
2738 or else Has_Pragma_Pack (Formal_Typ) /=
2739 Has_Pragma_Pack (Parent_Typ))
2741 Convert (Actual, Parent_Typ);
2744 Next_Actual (Actual);
2745 Next_Formal (Formal);
2746 Next_Formal (Parent_Formal);
2752 Subp := Parent_Subp;
2755 -- Check for violation of No_Abort_Statements
2757 if Is_RTE (Subp, RE_Abort_Task) then
2758 Check_Restriction (No_Abort_Statements, N);
2760 -- Check for violation of No_Dynamic_Attachment
2762 elsif RTU_Loaded (Ada_Interrupts)
2763 and then (Is_RTE (Subp, RE_Is_Reserved) or else
2764 Is_RTE (Subp, RE_Is_Attached) or else
2765 Is_RTE (Subp, RE_Current_Handler) or else
2766 Is_RTE (Subp, RE_Attach_Handler) or else
2767 Is_RTE (Subp, RE_Exchange_Handler) or else
2768 Is_RTE (Subp, RE_Detach_Handler) or else
2769 Is_RTE (Subp, RE_Reference))
2771 Check_Restriction (No_Dynamic_Attachment, N);
2774 -- Deal with case where call is an explicit dereference
2776 if Nkind (Name (N)) = N_Explicit_Dereference then
2778 -- Handle case of access to protected subprogram type
2780 if Is_Access_Protected_Subprogram_Type
2781 (Base_Type (Etype (Prefix (Name (N)))))
2783 -- If this is a call through an access to protected operation,
2784 -- the prefix has the form (object'address, operation'access).
2785 -- Rewrite as a for other protected calls: the object is the
2786 -- first parameter of the list of actuals.
2793 Ptr : constant Node_Id := Prefix (Name (N));
2795 T : constant Entity_Id :=
2796 Equivalent_Type (Base_Type (Etype (Ptr)));
2798 D_T : constant Entity_Id :=
2799 Designated_Type (Base_Type (Etype (Ptr)));
2803 Make_Selected_Component (Loc,
2804 Prefix => Unchecked_Convert_To (T, Ptr),
2806 New_Occurrence_Of (First_Entity (T), Loc));
2809 Make_Selected_Component (Loc,
2810 Prefix => Unchecked_Convert_To (T, Ptr),
2812 New_Occurrence_Of (Next_Entity (First_Entity (T)), Loc));
2815 Make_Explicit_Dereference (Loc,
2818 if Present (Parameter_Associations (N)) then
2819 Parm := Parameter_Associations (N);
2824 Prepend (Obj, Parm);
2826 if Etype (D_T) = Standard_Void_Type then
2828 Make_Procedure_Call_Statement (Loc,
2830 Parameter_Associations => Parm);
2833 Make_Function_Call (Loc,
2835 Parameter_Associations => Parm);
2838 Set_First_Named_Actual (Call, First_Named_Actual (N));
2839 Set_Etype (Call, Etype (D_T));
2841 -- We do not re-analyze the call to avoid infinite recursion.
2842 -- We analyze separately the prefix and the object, and set
2843 -- the checks on the prefix that would otherwise be emitted
2844 -- when resolving a call.
2848 Apply_Access_Check (Nam);
2855 -- If this is a call to an intrinsic subprogram, then perform the
2856 -- appropriate expansion to the corresponding tree node and we
2857 -- are all done (since after that the call is gone!)
2859 -- In the case where the intrinsic is to be processed by the back end,
2860 -- the call to Expand_Intrinsic_Call will do nothing, which is fine,
2861 -- since the idea in this case is to pass the call unchanged.
2862 -- If the intrinsic is an inherited unchecked conversion, and the
2863 -- derived type is the target type of the conversion, we must retain
2864 -- it as the return type of the expression. Otherwise the expansion
2865 -- below, which uses the parent operation, will yield the wrong type.
2867 if Is_Intrinsic_Subprogram (Subp) then
2868 Expand_Intrinsic_Call (N, Subp);
2870 if Nkind (N) = N_Unchecked_Type_Conversion
2871 and then Parent_Subp /= Orig_Subp
2872 and then Etype (Parent_Subp) /= Etype (Orig_Subp)
2874 Set_Etype (N, Etype (Orig_Subp));
2880 if Ekind (Subp) = E_Function
2881 or else Ekind (Subp) = E_Procedure
2883 if Is_Inlined (Subp) then
2885 Inlined_Subprogram : declare
2887 Must_Inline : Boolean := False;
2888 Spec : constant Node_Id := Unit_Declaration_Node (Subp);
2889 Scop : constant Entity_Id := Scope (Subp);
2891 function In_Unfrozen_Instance return Boolean;
2892 -- If the subprogram comes from an instance in the same
2893 -- unit, and the instance is not yet frozen, inlining might
2894 -- trigger order-of-elaboration problems in gigi.
2896 --------------------------
2897 -- In_Unfrozen_Instance --
2898 --------------------------
2900 function In_Unfrozen_Instance return Boolean is
2906 and then S /= Standard_Standard
2908 if Is_Generic_Instance (S)
2909 and then Present (Freeze_Node (S))
2910 and then not Analyzed (Freeze_Node (S))
2919 end In_Unfrozen_Instance;
2921 -- Start of processing for Inlined_Subprogram
2924 -- Verify that the body to inline has already been seen, and
2925 -- that if the body is in the current unit the inlining does
2926 -- not occur earlier. This avoids order-of-elaboration problems
2929 -- This should be documented in sinfo/einfo ???
2932 or else Nkind (Spec) /= N_Subprogram_Declaration
2933 or else No (Body_To_Inline (Spec))
2935 Must_Inline := False;
2937 -- If this an inherited function that returns a private
2938 -- type, do not inline if the full view is an unconstrained
2939 -- array, because such calls cannot be inlined.
2941 elsif Present (Orig_Subp)
2942 and then Is_Array_Type (Etype (Orig_Subp))
2943 and then not Is_Constrained (Etype (Orig_Subp))
2945 Must_Inline := False;
2947 elsif In_Unfrozen_Instance then
2948 Must_Inline := False;
2951 Bod := Body_To_Inline (Spec);
2953 if (In_Extended_Main_Code_Unit (N)
2954 or else In_Extended_Main_Code_Unit (Parent (N))
2955 or else Has_Pragma_Inline_Always (Subp))
2956 and then (not In_Same_Extended_Unit (Sloc (Bod), Loc)
2958 Earlier_In_Extended_Unit (Sloc (Bod), Loc))
2960 Must_Inline := True;
2962 -- If we are compiling a package body that is not the main
2963 -- unit, it must be for inlining/instantiation purposes,
2964 -- in which case we inline the call to insure that the same
2965 -- temporaries are generated when compiling the body by
2966 -- itself. Otherwise link errors can occur.
2968 -- If the function being called is itself in the main unit,
2969 -- we cannot inline, because there is a risk of double
2970 -- elaboration and/or circularity: the inlining can make
2971 -- visible a private entity in the body of the main unit,
2972 -- that gigi will see before its sees its proper definition.
2974 elsif not (In_Extended_Main_Code_Unit (N))
2975 and then In_Package_Body
2977 Must_Inline := not In_Extended_Main_Source_Unit (Subp);
2982 Expand_Inlined_Call (N, Subp, Orig_Subp);
2985 -- Let the back end handle it
2987 Add_Inlined_Body (Subp);
2989 if Front_End_Inlining
2990 and then Nkind (Spec) = N_Subprogram_Declaration
2991 and then (In_Extended_Main_Code_Unit (N))
2992 and then No (Body_To_Inline (Spec))
2993 and then not Has_Completion (Subp)
2994 and then In_Same_Extended_Unit (Sloc (Spec), Loc)
2997 ("cannot inline& (body not seen yet)?",
3001 end Inlined_Subprogram;
3005 -- Check for a protected subprogram. This is either an intra-object
3006 -- call, or a protected function call. Protected procedure calls are
3007 -- rewritten as entry calls and handled accordingly.
3009 -- In Ada 2005, this may be an indirect call to an access parameter
3010 -- that is an access_to_subprogram. In that case the anonymous type
3011 -- has a scope that is a protected operation, but the call is a
3014 Scop := Scope (Subp);
3016 if Nkind (N) /= N_Entry_Call_Statement
3017 and then Is_Protected_Type (Scop)
3018 and then Ekind (Subp) /= E_Subprogram_Type
3020 -- If the call is an internal one, it is rewritten as a call to
3021 -- to the corresponding unprotected subprogram.
3023 Expand_Protected_Subprogram_Call (N, Subp, Scop);
3026 -- Functions returning controlled objects need special attention
3027 -- If the return type is limited the context is an initialization
3028 -- and different processing applies.
3030 if Controlled_Type (Etype (Subp))
3031 and then not Is_Inherently_Limited_Type (Etype (Subp))
3032 and then not Is_Limited_Interface (Etype (Subp))
3034 Expand_Ctrl_Function_Call (N);
3037 -- Test for First_Optional_Parameter, and if so, truncate parameter
3038 -- list if there are optional parameters at the trailing end.
3039 -- Note we never delete procedures for call via a pointer.
3041 if (Ekind (Subp) = E_Procedure or else Ekind (Subp) = E_Function)
3042 and then Present (First_Optional_Parameter (Subp))
3045 Last_Keep_Arg : Node_Id;
3048 -- Last_Keep_Arg will hold the last actual that should be
3049 -- retained. If it remains empty at the end, it means that
3050 -- all parameters are optional.
3052 Last_Keep_Arg := Empty;
3054 -- Find first optional parameter, must be present since we
3055 -- checked the validity of the parameter before setting it.
3057 Formal := First_Formal (Subp);
3058 Actual := First_Actual (N);
3059 while Formal /= First_Optional_Parameter (Subp) loop
3060 Last_Keep_Arg := Actual;
3061 Next_Formal (Formal);
3062 Next_Actual (Actual);
3065 -- We have Formal and Actual pointing to the first potentially
3066 -- droppable argument. We can drop all the trailing arguments
3067 -- whose actual matches the default. Note that we know that all
3068 -- remaining formals have defaults, because we checked that this
3069 -- requirement was met before setting First_Optional_Parameter.
3071 -- We use Fully_Conformant_Expressions to check for identity
3072 -- between formals and actuals, which may miss some cases, but
3073 -- on the other hand, this is only an optimization (if we fail
3074 -- to truncate a parameter it does not affect functionality).
3075 -- So if the default is 3 and the actual is 1+2, we consider
3076 -- them unequal, which hardly seems worrisome.
3078 while Present (Formal) loop
3079 if not Fully_Conformant_Expressions
3080 (Actual, Default_Value (Formal))
3082 Last_Keep_Arg := Actual;
3085 Next_Formal (Formal);
3086 Next_Actual (Actual);
3089 -- If no arguments, delete entire list, this is the easy case
3091 if No (Last_Keep_Arg) then
3092 Set_Parameter_Associations (N, No_List);
3093 Set_First_Named_Actual (N, Empty);
3095 -- Case where at the last retained argument is positional. This
3096 -- is also an easy case, since the retained arguments are already
3097 -- in the right form, and we don't need to worry about the order
3098 -- of arguments that get eliminated.
3100 elsif Is_List_Member (Last_Keep_Arg) then
3101 while Present (Next (Last_Keep_Arg)) loop
3102 Discard_Node (Remove_Next (Last_Keep_Arg));
3105 Set_First_Named_Actual (N, Empty);
3107 -- This is the annoying case where the last retained argument
3108 -- is a named parameter. Since the original arguments are not
3109 -- in declaration order, we may have to delete some fairly
3110 -- random collection of arguments.
3118 -- First step, remove all the named parameters from the
3119 -- list (they are still chained using First_Named_Actual
3120 -- and Next_Named_Actual, so we have not lost them!)
3122 Temp := First (Parameter_Associations (N));
3124 -- Case of all parameters named, remove them all
3126 if Nkind (Temp) = N_Parameter_Association then
3127 while Is_Non_Empty_List (Parameter_Associations (N)) loop
3128 Temp := Remove_Head (Parameter_Associations (N));
3131 -- Case of mixed positional/named, remove named parameters
3134 while Nkind (Next (Temp)) /= N_Parameter_Association loop
3138 while Present (Next (Temp)) loop
3139 Remove (Next (Temp));
3143 -- Now we loop through the named parameters, till we get
3144 -- to the last one to be retained, adding them to the list.
3145 -- Note that the Next_Named_Actual list does not need to be
3146 -- touched since we are only reordering them on the actual
3147 -- parameter association list.
3149 Passoc := Parent (First_Named_Actual (N));
3151 Temp := Relocate_Node (Passoc);
3153 (Parameter_Associations (N), Temp);
3155 Last_Keep_Arg = Explicit_Actual_Parameter (Passoc);
3156 Passoc := Parent (Next_Named_Actual (Passoc));
3159 Set_Next_Named_Actual (Temp, Empty);
3162 Temp := Next_Named_Actual (Passoc);
3163 exit when No (Temp);
3164 Set_Next_Named_Actual
3165 (Passoc, Next_Named_Actual (Parent (Temp)));
3173 --------------------------
3174 -- Expand_Inlined_Call --
3175 --------------------------
3177 procedure Expand_Inlined_Call
3180 Orig_Subp : Entity_Id)
3182 Loc : constant Source_Ptr := Sloc (N);
3183 Is_Predef : constant Boolean :=
3184 Is_Predefined_File_Name
3185 (Unit_File_Name (Get_Source_Unit (Subp)));
3186 Orig_Bod : constant Node_Id :=
3187 Body_To_Inline (Unit_Declaration_Node (Subp));
3192 Decls : constant List_Id := New_List;
3193 Exit_Lab : Entity_Id := Empty;
3200 Ret_Type : Entity_Id;
3204 Temp_Typ : Entity_Id;
3206 Is_Unc : constant Boolean :=
3207 Is_Array_Type (Etype (Subp))
3208 and then not Is_Constrained (Etype (Subp));
3209 -- If the type returned by the function is unconstrained and the
3210 -- call can be inlined, special processing is required.
3212 function Is_Null_Procedure return Boolean;
3213 -- Predicate to recognize stubbed procedures and null procedures, for
3214 -- which there is no need for the full inlining mechanism.
3216 procedure Make_Exit_Label;
3217 -- Build declaration for exit label to be used in Return statements
3219 function Process_Formals (N : Node_Id) return Traverse_Result;
3220 -- Replace occurrence of a formal with the corresponding actual, or
3221 -- the thunk generated for it.
3223 function Process_Sloc (Nod : Node_Id) return Traverse_Result;
3224 -- If the call being expanded is that of an internal subprogram,
3225 -- set the sloc of the generated block to that of the call itself,
3226 -- so that the expansion is skipped by the -next- command in gdb.
3227 -- Same processing for a subprogram in a predefined file, e.g.
3228 -- Ada.Tags. If Debug_Generated_Code is true, suppress this change
3229 -- to simplify our own development.
3231 procedure Rewrite_Function_Call (N : Node_Id; Blk : Node_Id);
3232 -- If the function body is a single expression, replace call with
3233 -- expression, else insert block appropriately.
3235 procedure Rewrite_Procedure_Call (N : Node_Id; Blk : Node_Id);
3236 -- If procedure body has no local variables, inline body without
3237 -- creating block, otherwise rewrite call with block.
3239 function Formal_Is_Used_Once (Formal : Entity_Id) return Boolean;
3240 -- Determine whether a formal parameter is used only once in Orig_Bod
3242 -----------------------
3243 -- Is_Null_Procedure --
3244 -----------------------
3246 function Is_Null_Procedure return Boolean is
3247 Decl : constant Node_Id := Unit_Declaration_Node (Subp);
3250 if Ekind (Subp) /= E_Procedure then
3253 elsif Nkind (Orig_Bod) /= N_Subprogram_Body then
3256 -- Check if this is an Ada 2005 null procedure
3258 elsif Nkind (Decl) = N_Subprogram_Declaration
3259 and then Null_Present (Specification (Decl))
3263 -- Check if the body contains only a null statement, followed by the
3264 -- return statement added during expansion.
3268 Stat : constant Node_Id :=
3270 (Statements (Handled_Statement_Sequence (Orig_Bod)));
3272 Stat2 : constant Node_Id := Next (Stat);
3276 Nkind (Stat) = N_Null_Statement
3280 (Nkind (Stat2) = N_Simple_Return_Statement
3281 and then No (Next (Stat2))));
3284 end Is_Null_Procedure;
3286 ---------------------
3287 -- Make_Exit_Label --
3288 ---------------------
3290 procedure Make_Exit_Label is
3292 -- Create exit label for subprogram if one does not exist yet
3294 if No (Exit_Lab) then
3296 Make_Identifier (Loc,
3297 Chars => New_Internal_Name ('L'));
3299 Make_Defining_Identifier (Loc, Chars (Lab_Id)));
3300 Exit_Lab := Make_Label (Loc, Lab_Id);
3303 Make_Implicit_Label_Declaration (Loc,
3304 Defining_Identifier => Entity (Lab_Id),
3305 Label_Construct => Exit_Lab);
3307 end Make_Exit_Label;
3309 ---------------------
3310 -- Process_Formals --
3311 ---------------------
3313 function Process_Formals (N : Node_Id) return Traverse_Result is
3319 if Is_Entity_Name (N)
3320 and then Present (Entity (N))
3325 and then Scope (E) = Subp
3327 A := Renamed_Object (E);
3329 -- Rewrite the occurrence of the formal into an occurrence of
3330 -- the actual. Also establish visibility on the proper view of
3331 -- the actual's subtype for the body's context (if the actual's
3332 -- subtype is private at the call point but its full view is
3333 -- visible to the body, then the inlined tree here must be
3334 -- analyzed with the full view).
3336 if Is_Entity_Name (A) then
3337 Rewrite (N, New_Occurrence_Of (Entity (A), Loc));
3338 Check_Private_View (N);
3340 elsif Nkind (A) = N_Defining_Identifier then
3341 Rewrite (N, New_Occurrence_Of (A, Loc));
3342 Check_Private_View (N);
3347 Rewrite (N, New_Copy (A));
3353 elsif Nkind (N) = N_Simple_Return_Statement then
3354 if No (Expression (N)) then
3357 Make_Goto_Statement (Loc,
3358 Name => New_Copy (Lab_Id)));
3361 if Nkind (Parent (N)) = N_Handled_Sequence_Of_Statements
3362 and then Nkind (Parent (Parent (N))) = N_Subprogram_Body
3364 -- Function body is a single expression. No need for
3370 Num_Ret := Num_Ret + 1;
3374 -- Because of the presence of private types, the views of the
3375 -- expression and the context may be different, so place an
3376 -- unchecked conversion to the context type to avoid spurious
3377 -- errors, e.g. when the expression is a numeric literal and
3378 -- the context is private. If the expression is an aggregate,
3379 -- use a qualified expression, because an aggregate is not a
3380 -- legal argument of a conversion.
3382 if Nkind_In (Expression (N), N_Aggregate, N_Null) then
3384 Make_Qualified_Expression (Sloc (N),
3385 Subtype_Mark => New_Occurrence_Of (Ret_Type, Sloc (N)),
3386 Expression => Relocate_Node (Expression (N)));
3389 Unchecked_Convert_To
3390 (Ret_Type, Relocate_Node (Expression (N)));
3393 if Nkind (Targ) = N_Defining_Identifier then
3395 Make_Assignment_Statement (Loc,
3396 Name => New_Occurrence_Of (Targ, Loc),
3397 Expression => Ret));
3400 Make_Assignment_Statement (Loc,
3401 Name => New_Copy (Targ),
3402 Expression => Ret));
3405 Set_Assignment_OK (Name (N));
3407 if Present (Exit_Lab) then
3409 Make_Goto_Statement (Loc,
3410 Name => New_Copy (Lab_Id)));
3416 -- Remove pragma Unreferenced since it may refer to formals that
3417 -- are not visible in the inlined body, and in any case we will
3418 -- not be posting warnings on the inlined body so it is unneeded.
3420 elsif Nkind (N) = N_Pragma
3421 and then Pragma_Name (N) = Name_Unreferenced
3423 Rewrite (N, Make_Null_Statement (Sloc (N)));
3429 end Process_Formals;
3431 procedure Replace_Formals is new Traverse_Proc (Process_Formals);
3437 function Process_Sloc (Nod : Node_Id) return Traverse_Result is
3439 if not Debug_Generated_Code then
3440 Set_Sloc (Nod, Sloc (N));
3441 Set_Comes_From_Source (Nod, False);
3447 procedure Reset_Slocs is new Traverse_Proc (Process_Sloc);
3449 ---------------------------
3450 -- Rewrite_Function_Call --
3451 ---------------------------
3453 procedure Rewrite_Function_Call (N : Node_Id; Blk : Node_Id) is
3454 HSS : constant Node_Id := Handled_Statement_Sequence (Blk);
3455 Fst : constant Node_Id := First (Statements (HSS));
3458 -- Optimize simple case: function body is a single return statement,
3459 -- which has been expanded into an assignment.
3461 if Is_Empty_List (Declarations (Blk))
3462 and then Nkind (Fst) = N_Assignment_Statement
3463 and then No (Next (Fst))
3466 -- The function call may have been rewritten as the temporary
3467 -- that holds the result of the call, in which case remove the
3468 -- now useless declaration.
3470 if Nkind (N) = N_Identifier
3471 and then Nkind (Parent (Entity (N))) = N_Object_Declaration
3473 Rewrite (Parent (Entity (N)), Make_Null_Statement (Loc));
3476 Rewrite (N, Expression (Fst));
3478 elsif Nkind (N) = N_Identifier
3479 and then Nkind (Parent (Entity (N))) = N_Object_Declaration
3481 -- The block assigns the result of the call to the temporary
3483 Insert_After (Parent (Entity (N)), Blk);
3485 elsif Nkind (Parent (N)) = N_Assignment_Statement
3487 (Is_Entity_Name (Name (Parent (N)))
3489 (Nkind (Name (Parent (N))) = N_Explicit_Dereference
3490 and then Is_Entity_Name (Prefix (Name (Parent (N))))))
3492 -- Replace assignment with the block
3495 Original_Assignment : constant Node_Id := Parent (N);
3498 -- Preserve the original assignment node to keep the complete
3499 -- assignment subtree consistent enough for Analyze_Assignment
3500 -- to proceed (specifically, the original Lhs node must still
3501 -- have an assignment statement as its parent).
3503 -- We cannot rely on Original_Node to go back from the block
3504 -- node to the assignment node, because the assignment might
3505 -- already be a rewrite substitution.
3507 Discard_Node (Relocate_Node (Original_Assignment));
3508 Rewrite (Original_Assignment, Blk);
3511 elsif Nkind (Parent (N)) = N_Object_Declaration then
3512 Set_Expression (Parent (N), Empty);
3513 Insert_After (Parent (N), Blk);
3516 Insert_Before (Parent (N), Blk);
3518 end Rewrite_Function_Call;
3520 ----------------------------
3521 -- Rewrite_Procedure_Call --
3522 ----------------------------
3524 procedure Rewrite_Procedure_Call (N : Node_Id; Blk : Node_Id) is
3525 HSS : constant Node_Id := Handled_Statement_Sequence (Blk);
3527 -- If there is a transient scope for N, this will be the scope of the
3528 -- actions for N, and the statements in Blk need to be within this
3529 -- scope. For example, they need to have visibility on the constant
3530 -- declarations created for the formals.
3532 -- If N needs no transient scope, and if there are no declarations in
3533 -- the inlined body, we can do a little optimization and insert the
3534 -- statements for the body directly after N, and rewrite N to a
3535 -- null statement, instead of rewriting N into a full-blown block
3538 if not Scope_Is_Transient
3539 and then Is_Empty_List (Declarations (Blk))
3541 Insert_List_After (N, Statements (HSS));
3542 Rewrite (N, Make_Null_Statement (Loc));
3546 end Rewrite_Procedure_Call;
3548 -------------------------
3549 -- Formal_Is_Used_Once --
3550 -------------------------
3552 function Formal_Is_Used_Once (Formal : Entity_Id) return Boolean is
3553 Use_Counter : Int := 0;
3555 function Count_Uses (N : Node_Id) return Traverse_Result;
3556 -- Traverse the tree and count the uses of the formal parameter.
3557 -- In this case, for optimization purposes, we do not need to
3558 -- continue the traversal once more than one use is encountered.
3564 function Count_Uses (N : Node_Id) return Traverse_Result is
3566 -- The original node is an identifier
3568 if Nkind (N) = N_Identifier
3569 and then Present (Entity (N))
3571 -- Original node's entity points to the one in the copied body
3573 and then Nkind (Entity (N)) = N_Identifier
3574 and then Present (Entity (Entity (N)))
3576 -- The entity of the copied node is the formal parameter
3578 and then Entity (Entity (N)) = Formal
3580 Use_Counter := Use_Counter + 1;
3582 if Use_Counter > 1 then
3584 -- Denote more than one use and abandon the traversal
3595 procedure Count_Formal_Uses is new Traverse_Proc (Count_Uses);
3597 -- Start of processing for Formal_Is_Used_Once
3600 Count_Formal_Uses (Orig_Bod);
3601 return Use_Counter = 1;
3602 end Formal_Is_Used_Once;
3604 -- Start of processing for Expand_Inlined_Call
3607 -- Check for special case of To_Address call, and if so, just do an
3608 -- unchecked conversion instead of expanding the call. Not only is this
3609 -- more efficient, but it also avoids problem with order of elaboration
3610 -- when address clauses are inlined (address expression elaborated at
3613 if Subp = RTE (RE_To_Address) then
3615 Unchecked_Convert_To
3617 Relocate_Node (First_Actual (N))));
3620 elsif Is_Null_Procedure then
3621 Rewrite (N, Make_Null_Statement (Loc));
3625 -- Check for an illegal attempt to inline a recursive procedure. If the
3626 -- subprogram has parameters this is detected when trying to supply a
3627 -- binding for parameters that already have one. For parameterless
3628 -- subprograms this must be done explicitly.
3630 if In_Open_Scopes (Subp) then
3631 Error_Msg_N ("call to recursive subprogram cannot be inlined?", N);
3632 Set_Is_Inlined (Subp, False);
3636 if Nkind (Orig_Bod) = N_Defining_Identifier
3637 or else Nkind (Orig_Bod) = N_Defining_Operator_Symbol
3639 -- Subprogram is a renaming_as_body. Calls appearing after the
3640 -- renaming can be replaced with calls to the renamed entity
3641 -- directly, because the subprograms are subtype conformant. If
3642 -- the renamed subprogram is an inherited operation, we must redo
3643 -- the expansion because implicit conversions may be needed.
3645 Set_Name (N, New_Occurrence_Of (Orig_Bod, Loc));
3647 if Present (Alias (Orig_Bod)) then
3654 -- Use generic machinery to copy body of inlined subprogram, as if it
3655 -- were an instantiation, resetting source locations appropriately, so
3656 -- that nested inlined calls appear in the main unit.
3658 Save_Env (Subp, Empty);
3659 Set_Copied_Sloc_For_Inlined_Body (N, Defining_Entity (Orig_Bod));
3661 Bod := Copy_Generic_Node (Orig_Bod, Empty, Instantiating => True);
3663 Make_Block_Statement (Loc,
3664 Declarations => Declarations (Bod),
3665 Handled_Statement_Sequence => Handled_Statement_Sequence (Bod));
3667 if No (Declarations (Bod)) then
3668 Set_Declarations (Blk, New_List);
3671 -- For the unconstrained case, capture the name of the local
3672 -- variable that holds the result. This must be the first declaration
3673 -- in the block, because its bounds cannot depend on local variables.
3674 -- Otherwise there is no way to declare the result outside of the
3675 -- block. Needless to say, in general the bounds will depend on the
3676 -- actuals in the call.
3679 Targ1 := Defining_Identifier (First (Declarations (Blk)));
3682 -- If this is a derived function, establish the proper return type
3684 if Present (Orig_Subp)
3685 and then Orig_Subp /= Subp
3687 Ret_Type := Etype (Orig_Subp);
3689 Ret_Type := Etype (Subp);
3692 -- Create temporaries for the actuals that are expressions, or that
3693 -- are scalars and require copying to preserve semantics.
3695 F := First_Formal (Subp);
3696 A := First_Actual (N);
3697 while Present (F) loop
3698 if Present (Renamed_Object (F)) then
3699 Error_Msg_N ("cannot inline call to recursive subprogram", N);
3703 -- If the argument may be a controlling argument in a call within
3704 -- the inlined body, we must preserve its classwide nature to insure
3705 -- that dynamic dispatching take place subsequently. If the formal
3706 -- has a constraint it must be preserved to retain the semantics of
3709 if Is_Class_Wide_Type (Etype (F))
3710 or else (Is_Access_Type (Etype (F))
3712 Is_Class_Wide_Type (Designated_Type (Etype (F))))
3714 Temp_Typ := Etype (F);
3716 elsif Base_Type (Etype (F)) = Base_Type (Etype (A))
3717 and then Etype (F) /= Base_Type (Etype (F))
3719 Temp_Typ := Etype (F);
3722 Temp_Typ := Etype (A);
3725 -- If the actual is a simple name or a literal, no need to
3726 -- create a temporary, object can be used directly.
3728 -- If the actual is a literal and the formal has its address taken,
3729 -- we cannot pass the literal itself as an argument, so its value
3730 -- must be captured in a temporary.
3732 if (Is_Entity_Name (A)
3734 (not Is_Scalar_Type (Etype (A))
3735 or else Ekind (Entity (A)) = E_Enumeration_Literal))
3737 -- When the actual is an identifier and the corresponding formal
3738 -- is used only once in the original body, the formal can be
3739 -- substituted directly with the actual parameter.
3741 or else (Nkind (A) = N_Identifier
3742 and then Formal_Is_Used_Once (F))
3745 (Nkind_In (A, N_Real_Literal,
3747 N_Character_Literal)
3748 and then not Address_Taken (F))
3750 if Etype (F) /= Etype (A) then
3752 (F, Unchecked_Convert_To (Etype (F), Relocate_Node (A)));
3754 Set_Renamed_Object (F, A);
3759 Make_Defining_Identifier (Loc,
3760 Chars => New_Internal_Name ('C'));
3762 -- If the actual for an in/in-out parameter is a view conversion,
3763 -- make it into an unchecked conversion, given that an untagged
3764 -- type conversion is not a proper object for a renaming.
3766 -- In-out conversions that involve real conversions have already
3767 -- been transformed in Expand_Actuals.
3769 if Nkind (A) = N_Type_Conversion
3770 and then Ekind (F) /= E_In_Parameter
3773 Make_Unchecked_Type_Conversion (Loc,
3774 Subtype_Mark => New_Occurrence_Of (Etype (F), Loc),
3775 Expression => Relocate_Node (Expression (A)));
3777 elsif Etype (F) /= Etype (A) then
3778 New_A := Unchecked_Convert_To (Etype (F), Relocate_Node (A));
3779 Temp_Typ := Etype (F);
3782 New_A := Relocate_Node (A);
3785 Set_Sloc (New_A, Sloc (N));
3787 -- If the actual has a by-reference type, it cannot be copied, so
3788 -- its value is captured in a renaming declaration. Otherwise
3789 -- declare a local constant initialized with the actual.
3791 if Ekind (F) = E_In_Parameter
3792 and then not Is_Limited_Type (Etype (A))
3793 and then not Is_Tagged_Type (Etype (A))
3796 Make_Object_Declaration (Loc,
3797 Defining_Identifier => Temp,
3798 Constant_Present => True,
3799 Object_Definition => New_Occurrence_Of (Temp_Typ, Loc),
3800 Expression => New_A);
3803 Make_Object_Renaming_Declaration (Loc,
3804 Defining_Identifier => Temp,
3805 Subtype_Mark => New_Occurrence_Of (Temp_Typ, Loc),
3809 Append (Decl, Decls);
3810 Set_Renamed_Object (F, Temp);
3817 -- Establish target of function call. If context is not assignment or
3818 -- declaration, create a temporary as a target. The declaration for
3819 -- the temporary may be subsequently optimized away if the body is a
3820 -- single expression, or if the left-hand side of the assignment is
3821 -- simple enough, i.e. an entity or an explicit dereference of one.
3823 if Ekind (Subp) = E_Function then
3824 if Nkind (Parent (N)) = N_Assignment_Statement
3825 and then Is_Entity_Name (Name (Parent (N)))
3827 Targ := Name (Parent (N));
3829 elsif Nkind (Parent (N)) = N_Assignment_Statement
3830 and then Nkind (Name (Parent (N))) = N_Explicit_Dereference
3831 and then Is_Entity_Name (Prefix (Name (Parent (N))))
3833 Targ := Name (Parent (N));
3836 -- Replace call with temporary and create its declaration
3839 Make_Defining_Identifier (Loc, New_Internal_Name ('C'));
3840 Set_Is_Internal (Temp);
3842 -- For the unconstrained case. the generated temporary has the
3843 -- same constrained declaration as the result variable.
3844 -- It may eventually be possible to remove that temporary and
3845 -- use the result variable directly.
3849 Make_Object_Declaration (Loc,
3850 Defining_Identifier => Temp,
3851 Object_Definition =>
3852 New_Copy_Tree (Object_Definition (Parent (Targ1))));
3854 Replace_Formals (Decl);
3858 Make_Object_Declaration (Loc,
3859 Defining_Identifier => Temp,
3860 Object_Definition =>
3861 New_Occurrence_Of (Ret_Type, Loc));
3863 Set_Etype (Temp, Ret_Type);
3866 Set_No_Initialization (Decl);
3867 Append (Decl, Decls);
3868 Rewrite (N, New_Occurrence_Of (Temp, Loc));
3873 Insert_Actions (N, Decls);
3875 -- Traverse the tree and replace formals with actuals or their thunks.
3876 -- Attach block to tree before analysis and rewriting.
3878 Replace_Formals (Blk);
3879 Set_Parent (Blk, N);
3881 if not Comes_From_Source (Subp)
3887 if Present (Exit_Lab) then
3889 -- If the body was a single expression, the single return statement
3890 -- and the corresponding label are useless.
3894 Nkind (Last (Statements (Handled_Statement_Sequence (Blk)))) =
3897 Remove (Last (Statements (Handled_Statement_Sequence (Blk))));
3899 Append (Lab_Decl, (Declarations (Blk)));
3900 Append (Exit_Lab, Statements (Handled_Statement_Sequence (Blk)));
3904 -- Analyze Blk with In_Inlined_Body set, to avoid spurious errors on
3905 -- conflicting private views that Gigi would ignore. If this is
3906 -- predefined unit, analyze with checks off, as is done in the non-
3907 -- inlined run-time units.
3910 I_Flag : constant Boolean := In_Inlined_Body;
3913 In_Inlined_Body := True;
3917 Style : constant Boolean := Style_Check;
3919 Style_Check := False;
3920 Analyze (Blk, Suppress => All_Checks);
3921 Style_Check := Style;
3928 In_Inlined_Body := I_Flag;
3931 if Ekind (Subp) = E_Procedure then
3932 Rewrite_Procedure_Call (N, Blk);
3934 Rewrite_Function_Call (N, Blk);
3936 -- For the unconstrained case, the replacement of the call has been
3937 -- made prior to the complete analysis of the generated declarations.
3938 -- Propagate the proper type now.
3941 if Nkind (N) = N_Identifier then
3942 Set_Etype (N, Etype (Entity (N)));
3944 Set_Etype (N, Etype (Targ1));
3951 -- Cleanup mapping between formals and actuals for other expansions
3953 F := First_Formal (Subp);
3954 while Present (F) loop
3955 Set_Renamed_Object (F, Empty);
3958 end Expand_Inlined_Call;
3960 ----------------------------
3961 -- Expand_N_Function_Call --
3962 ----------------------------
3964 procedure Expand_N_Function_Call (N : Node_Id) is
3968 -- If the return value of a foreign compiled function is
3969 -- VAX Float then expand the return (adjusts the location
3970 -- of the return value on Alpha/VMS, noop everywere else).
3971 -- Comes_From_Source intercepts recursive expansion.
3973 if Vax_Float (Etype (N))
3974 and then Nkind (N) = N_Function_Call
3975 and then Present (Name (N))
3976 and then Present (Entity (Name (N)))
3977 and then Has_Foreign_Convention (Entity (Name (N)))
3978 and then Comes_From_Source (Parent (N))
3980 Expand_Vax_Foreign_Return (N);
3982 end Expand_N_Function_Call;
3984 ---------------------------------------
3985 -- Expand_N_Procedure_Call_Statement --
3986 ---------------------------------------
3988 procedure Expand_N_Procedure_Call_Statement (N : Node_Id) is
3991 end Expand_N_Procedure_Call_Statement;
3993 ------------------------------
3994 -- Expand_N_Subprogram_Body --
3995 ------------------------------
3997 -- Add poll call if ATC polling is enabled, unless the body will be
3998 -- inlined by the back-end.
4000 -- Add dummy push/pop label nodes at start and end to clear any local
4001 -- exception indications if local-exception-to-goto optimization active.
4003 -- Add return statement if last statement in body is not a return statement
4004 -- (this makes things easier on Gigi which does not want to have to handle
4005 -- a missing return).
4007 -- Add call to Activate_Tasks if body is a task activator
4009 -- Deal with possible detection of infinite recursion
4011 -- Eliminate body completely if convention stubbed
4013 -- Encode entity names within body, since we will not need to reference
4014 -- these entities any longer in the front end.
4016 -- Initialize scalar out parameters if Initialize/Normalize_Scalars
4018 -- Reset Pure indication if any parameter has root type System.Address
4022 procedure Expand_N_Subprogram_Body (N : Node_Id) is
4023 Loc : constant Source_Ptr := Sloc (N);
4024 H : constant Node_Id := Handled_Statement_Sequence (N);
4025 Body_Id : Entity_Id;
4028 Spec_Id : Entity_Id;
4030 procedure Add_Return (S : List_Id);
4031 -- Append a return statement to the statement sequence S if the last
4032 -- statement is not already a return or a goto statement. Note that
4033 -- the latter test is not critical, it does not matter if we add a
4034 -- few extra returns, since they get eliminated anyway later on.
4040 procedure Add_Return (S : List_Id) is
4045 -- Get last statement, ignoring any Pop_xxx_Label nodes, which are
4046 -- not relevant in this context since they are not executable.
4048 Last_Stm := Last (S);
4049 while Nkind (Last_Stm) in N_Pop_xxx_Label loop
4053 -- Now insert return unless last statement is a transfer
4055 if not Is_Transfer (Last_Stm) then
4057 -- The source location for the return is the end label of the
4058 -- procedure if present. Otherwise use the sloc of the last
4059 -- statement in the list. If the list comes from a generated
4060 -- exception handler and we are not debugging generated code,
4061 -- all the statements within the handler are made invisible
4064 if Nkind (Parent (S)) = N_Exception_Handler
4065 and then not Comes_From_Source (Parent (S))
4067 Loc := Sloc (Last_Stm);
4069 elsif Present (End_Label (H)) then
4070 Loc := Sloc (End_Label (H));
4073 Loc := Sloc (Last_Stm);
4076 Append_To (S, Make_Simple_Return_Statement (Loc));
4080 -- Start of processing for Expand_N_Subprogram_Body
4083 -- Set L to either the list of declarations if present, or
4084 -- to the list of statements if no declarations are present.
4085 -- This is used to insert new stuff at the start.
4087 if Is_Non_Empty_List (Declarations (N)) then
4088 L := Declarations (N);
4090 L := Statements (H);
4093 -- If local-exception-to-goto optimization active, insert dummy push
4094 -- statements at start, and dummy pop statements at end.
4096 if (Debug_Flag_Dot_G
4097 or else Restriction_Active (No_Exception_Propagation))
4098 and then Is_Non_Empty_List (L)
4101 FS : constant Node_Id := First (L);
4102 FL : constant Source_Ptr := Sloc (FS);
4107 -- LS points to either last statement, if statements are present
4108 -- or to the last declaration if there are no statements present.
4109 -- It is the node after which the pop's are generated.
4111 if Is_Non_Empty_List (Statements (H)) then
4112 LS := Last (Statements (H));
4119 Insert_List_Before_And_Analyze (FS, New_List (
4120 Make_Push_Constraint_Error_Label (FL),
4121 Make_Push_Program_Error_Label (FL),
4122 Make_Push_Storage_Error_Label (FL)));
4124 Insert_List_After_And_Analyze (LS, New_List (
4125 Make_Pop_Constraint_Error_Label (LL),
4126 Make_Pop_Program_Error_Label (LL),
4127 Make_Pop_Storage_Error_Label (LL)));
4131 -- Find entity for subprogram
4133 Body_Id := Defining_Entity (N);
4135 if Present (Corresponding_Spec (N)) then
4136 Spec_Id := Corresponding_Spec (N);
4141 -- Need poll on entry to subprogram if polling enabled. We only do this
4142 -- for non-empty subprograms, since it does not seem necessary to poll
4143 -- for a dummy null subprogram. Do not add polling point if calls to
4144 -- this subprogram will be inlined by the back-end, to avoid repeated
4145 -- polling points in nested inlinings.
4147 if Is_Non_Empty_List (L) then
4148 if Is_Inlined (Spec_Id)
4149 and then Front_End_Inlining
4150 and then Optimization_Level > 1
4154 Generate_Poll_Call (First (L));
4158 -- If this is a Pure function which has any parameters whose root
4159 -- type is System.Address, reset the Pure indication, since it will
4160 -- likely cause incorrect code to be generated as the parameter is
4161 -- probably a pointer, and the fact that the same pointer is passed
4162 -- does not mean that the same value is being referenced.
4164 -- Note that if the programmer gave an explicit Pure_Function pragma,
4165 -- then we believe the programmer, and leave the subprogram Pure.
4167 -- This code should probably be at the freeze point, so that it
4168 -- happens even on a -gnatc (or more importantly -gnatt) compile
4169 -- so that the semantic tree has Is_Pure set properly ???
4171 if Is_Pure (Spec_Id)
4172 and then Is_Subprogram (Spec_Id)
4173 and then not Has_Pragma_Pure_Function (Spec_Id)
4179 F := First_Formal (Spec_Id);
4180 while Present (F) loop
4181 if Is_Descendent_Of_Address (Etype (F)) then
4182 Set_Is_Pure (Spec_Id, False);
4184 if Spec_Id /= Body_Id then
4185 Set_Is_Pure (Body_Id, False);
4196 -- Initialize any scalar OUT args if Initialize/Normalize_Scalars
4198 if Init_Or_Norm_Scalars and then Is_Subprogram (Spec_Id) then
4203 -- Loop through formals
4205 F := First_Formal (Spec_Id);
4206 while Present (F) loop
4207 if Is_Scalar_Type (Etype (F))
4208 and then Ekind (F) = E_Out_Parameter
4210 Check_Restriction (No_Default_Initialization, F);
4212 -- Insert the initialization. We turn off validity checks
4213 -- for this assignment, since we do not want any check on
4214 -- the initial value itself (which may well be invalid).
4216 Insert_Before_And_Analyze (First (L),
4217 Make_Assignment_Statement (Loc,
4218 Name => New_Occurrence_Of (F, Loc),
4219 Expression => Get_Simple_Init_Val (Etype (F), N)),
4220 Suppress => Validity_Check);
4228 -- Clear out statement list for stubbed procedure
4230 if Present (Corresponding_Spec (N)) then
4231 Set_Elaboration_Flag (N, Spec_Id);
4233 if Convention (Spec_Id) = Convention_Stubbed
4234 or else Is_Eliminated (Spec_Id)
4236 Set_Declarations (N, Empty_List);
4237 Set_Handled_Statement_Sequence (N,
4238 Make_Handled_Sequence_Of_Statements (Loc,
4239 Statements => New_List (
4240 Make_Null_Statement (Loc))));
4245 -- Create a set of discriminals for the next protected subprogram body
4247 if Is_List_Member (N)
4248 and then Present (Parent (List_Containing (N)))
4249 and then Nkind (Parent (List_Containing (N))) = N_Protected_Body
4250 and then Present (Next_Protected_Operation (N))
4252 Set_Discriminals (Parent (Base_Type (Scope (Spec_Id))));
4255 -- Returns_By_Ref flag is normally set when the subprogram is frozen
4256 -- but subprograms with no specs are not frozen.
4259 Typ : constant Entity_Id := Etype (Spec_Id);
4260 Utyp : constant Entity_Id := Underlying_Type (Typ);
4263 if not Acts_As_Spec (N)
4264 and then Nkind (Parent (Parent (Spec_Id))) /=
4265 N_Subprogram_Body_Stub
4269 elsif Is_Inherently_Limited_Type (Typ) then
4270 Set_Returns_By_Ref (Spec_Id);
4272 elsif Present (Utyp) and then CW_Or_Controlled_Type (Utyp) then
4273 Set_Returns_By_Ref (Spec_Id);
4277 -- For a procedure, we add a return for all possible syntactic ends
4278 -- of the subprogram. Note that reanalysis is not necessary in this
4279 -- case since it would require a lot of work and accomplish nothing.
4281 if Ekind (Spec_Id) = E_Procedure
4282 or else Ekind (Spec_Id) = E_Generic_Procedure
4284 Add_Return (Statements (H));
4286 if Present (Exception_Handlers (H)) then
4287 Except_H := First_Non_Pragma (Exception_Handlers (H));
4288 while Present (Except_H) loop
4289 Add_Return (Statements (Except_H));
4290 Next_Non_Pragma (Except_H);
4294 -- For a function, we must deal with the case where there is at least
4295 -- one missing return. What we do is to wrap the entire body of the
4296 -- function in a block:
4309 -- raise Program_Error;
4312 -- This approach is necessary because the raise must be signalled
4313 -- to the caller, not handled by any local handler (RM 6.4(11)).
4315 -- Note: we do not need to analyze the constructed sequence here,
4316 -- since it has no handler, and an attempt to analyze the handled
4317 -- statement sequence twice is risky in various ways (e.g. the
4318 -- issue of expanding cleanup actions twice).
4320 elsif Has_Missing_Return (Spec_Id) then
4322 Hloc : constant Source_Ptr := Sloc (H);
4323 Blok : constant Node_Id :=
4324 Make_Block_Statement (Hloc,
4325 Handled_Statement_Sequence => H);
4326 Rais : constant Node_Id :=
4327 Make_Raise_Program_Error (Hloc,
4328 Reason => PE_Missing_Return);
4331 Set_Handled_Statement_Sequence (N,
4332 Make_Handled_Sequence_Of_Statements (Hloc,
4333 Statements => New_List (Blok, Rais)));
4335 Push_Scope (Spec_Id);
4342 -- If subprogram contains a parameterless recursive call, then we may
4343 -- have an infinite recursion, so see if we can generate code to check
4344 -- for this possibility if storage checks are not suppressed.
4346 if Ekind (Spec_Id) = E_Procedure
4347 and then Has_Recursive_Call (Spec_Id)
4348 and then not Storage_Checks_Suppressed (Spec_Id)
4350 Detect_Infinite_Recursion (N, Spec_Id);
4353 -- Set to encode entity names in package body before gigi is called
4355 Qualify_Entity_Names (N);
4356 end Expand_N_Subprogram_Body;
4358 -----------------------------------
4359 -- Expand_N_Subprogram_Body_Stub --
4360 -----------------------------------
4362 procedure Expand_N_Subprogram_Body_Stub (N : Node_Id) is
4364 if Present (Corresponding_Body (N)) then
4365 Expand_N_Subprogram_Body (
4366 Unit_Declaration_Node (Corresponding_Body (N)));
4368 end Expand_N_Subprogram_Body_Stub;
4370 -------------------------------------
4371 -- Expand_N_Subprogram_Declaration --
4372 -------------------------------------
4374 -- If the declaration appears within a protected body, it is a private
4375 -- operation of the protected type. We must create the corresponding
4376 -- protected subprogram an associated formals. For a normal protected
4377 -- operation, this is done when expanding the protected type declaration.
4379 -- If the declaration is for a null procedure, emit null body
4381 procedure Expand_N_Subprogram_Declaration (N : Node_Id) is
4382 Loc : constant Source_Ptr := Sloc (N);
4383 Subp : constant Entity_Id := Defining_Entity (N);
4384 Scop : constant Entity_Id := Scope (Subp);
4385 Prot_Decl : Node_Id;
4387 Prot_Id : Entity_Id;
4390 -- Deal with case of protected subprogram. Do not generate protected
4391 -- operation if operation is flagged as eliminated.
4393 if Is_List_Member (N)
4394 and then Present (Parent (List_Containing (N)))
4395 and then Nkind (Parent (List_Containing (N))) = N_Protected_Body
4396 and then Is_Protected_Type (Scop)
4398 if No (Protected_Body_Subprogram (Subp))
4399 and then not Is_Eliminated (Subp)
4402 Make_Subprogram_Declaration (Loc,
4404 Build_Protected_Sub_Specification
4405 (N, Scop, Unprotected_Mode));
4407 -- The protected subprogram is declared outside of the protected
4408 -- body. Given that the body has frozen all entities so far, we
4409 -- analyze the subprogram and perform freezing actions explicitly.
4410 -- including the generation of an explicit freeze node, to ensure
4411 -- that gigi has the proper order of elaboration.
4412 -- If the body is a subunit, the insertion point is before the
4413 -- stub in the parent.
4415 Prot_Bod := Parent (List_Containing (N));
4417 if Nkind (Parent (Prot_Bod)) = N_Subunit then
4418 Prot_Bod := Corresponding_Stub (Parent (Prot_Bod));
4421 Insert_Before (Prot_Bod, Prot_Decl);
4422 Prot_Id := Defining_Unit_Name (Specification (Prot_Decl));
4423 Set_Has_Delayed_Freeze (Prot_Id);
4425 Push_Scope (Scope (Scop));
4426 Analyze (Prot_Decl);
4427 Insert_Actions (N, Freeze_Entity (Prot_Id, Loc));
4428 Set_Protected_Body_Subprogram (Subp, Prot_Id);
4432 -- Ada 2005 (AI-348): Generation of the null body
4434 elsif Nkind (Specification (N)) = N_Procedure_Specification
4435 and then Null_Present (Specification (N))
4438 Bod : constant Node_Id :=
4439 Make_Subprogram_Body (Loc,
4441 New_Copy_Tree (Specification (N)),
4442 Declarations => New_List,
4443 Handled_Statement_Sequence =>
4444 Make_Handled_Sequence_Of_Statements (Loc,
4445 Statements => New_List (Make_Null_Statement (Loc))));
4447 Set_Body_To_Inline (N, Bod);
4448 Insert_After (N, Bod);
4451 -- Corresponding_Spec isn't being set by Analyze_Subprogram_Body,
4452 -- evidently because Set_Has_Completion is called earlier for null
4453 -- procedures in Analyze_Subprogram_Declaration, so we force its
4454 -- setting here. If the setting of Has_Completion is not set
4455 -- earlier, then it can result in missing body errors if other
4456 -- errors were already reported (since expansion is turned off).
4458 -- Should creation of the empty body be moved to the analyzer???
4460 Set_Corresponding_Spec (Bod, Defining_Entity (Specification (N)));
4463 end Expand_N_Subprogram_Declaration;
4465 ---------------------------------------
4466 -- Expand_Protected_Object_Reference --
4467 ---------------------------------------
4469 function Expand_Protected_Object_Reference
4471 Scop : Entity_Id) return Node_Id
4473 Loc : constant Source_Ptr := Sloc (N);
4481 Make_Identifier (Loc,
4482 Chars => Name_uObject);
4483 Set_Etype (Rec, Corresponding_Record_Type (Scop));
4485 -- Find enclosing protected operation, and retrieve its first parameter,
4486 -- which denotes the enclosing protected object. If the enclosing
4487 -- operation is an entry, we are immediately within the protected body,
4488 -- and we can retrieve the object from the service entries procedure. A
4489 -- barrier function has has the same signature as an entry. A barrier
4490 -- function is compiled within the protected object, but unlike
4491 -- protected operations its never needs locks, so that its protected
4492 -- body subprogram points to itself.
4494 Proc := Current_Scope;
4495 while Present (Proc)
4496 and then Scope (Proc) /= Scop
4498 Proc := Scope (Proc);
4501 Corr := Protected_Body_Subprogram (Proc);
4505 -- Previous error left expansion incomplete.
4506 -- Nothing to do on this call.
4513 (First (Parameter_Specifications (Parent (Corr))));
4515 if Is_Subprogram (Proc)
4516 and then Proc /= Corr
4518 -- Protected function or procedure
4520 Set_Entity (Rec, Param);
4522 -- Rec is a reference to an entity which will not be in scope when
4523 -- the call is reanalyzed, and needs no further analysis.
4528 -- Entry or barrier function for entry body. The first parameter of
4529 -- the entry body procedure is pointer to the object. We create a
4530 -- local variable of the proper type, duplicating what is done to
4531 -- define _object later on.
4535 Obj_Ptr : constant Entity_Id := Make_Defining_Identifier (Loc,
4537 New_Internal_Name ('T'));
4541 Make_Full_Type_Declaration (Loc,
4542 Defining_Identifier => Obj_Ptr,
4544 Make_Access_To_Object_Definition (Loc,
4545 Subtype_Indication =>
4547 (Corresponding_Record_Type (Scop), Loc))));
4549 Insert_Actions (N, Decls);
4550 Insert_Actions (N, Freeze_Entity (Obj_Ptr, Sloc (N)));
4553 Make_Explicit_Dereference (Loc,
4554 Unchecked_Convert_To (Obj_Ptr,
4555 New_Occurrence_Of (Param, Loc)));
4557 -- Analyze new actual. Other actuals in calls are already analyzed
4558 -- and the list of actuals is not reanalyzed after rewriting.
4560 Set_Parent (Rec, N);
4566 end Expand_Protected_Object_Reference;
4568 --------------------------------------
4569 -- Expand_Protected_Subprogram_Call --
4570 --------------------------------------
4572 procedure Expand_Protected_Subprogram_Call
4580 -- If the protected object is not an enclosing scope, this is
4581 -- an inter-object function call. Inter-object procedure
4582 -- calls are expanded by Exp_Ch9.Build_Simple_Entry_Call.
4583 -- The call is intra-object only if the subprogram being
4584 -- called is in the protected body being compiled, and if the
4585 -- protected object in the call is statically the enclosing type.
4586 -- The object may be an component of some other data structure,
4587 -- in which case this must be handled as an inter-object call.
4589 if not In_Open_Scopes (Scop)
4590 or else not Is_Entity_Name (Name (N))
4592 if Nkind (Name (N)) = N_Selected_Component then
4593 Rec := Prefix (Name (N));
4596 pragma Assert (Nkind (Name (N)) = N_Indexed_Component);
4597 Rec := Prefix (Prefix (Name (N)));
4600 Build_Protected_Subprogram_Call (N,
4601 Name => New_Occurrence_Of (Subp, Sloc (N)),
4602 Rec => Convert_Concurrent (Rec, Etype (Rec)),
4606 Rec := Expand_Protected_Object_Reference (N, Scop);
4612 Build_Protected_Subprogram_Call (N,
4621 -- If it is a function call it can appear in elaboration code and
4622 -- the called entity must be frozen here.
4624 if Ekind (Subp) = E_Function then
4625 Freeze_Expression (Name (N));
4627 end Expand_Protected_Subprogram_Call;
4629 --------------------------------
4630 -- Is_Build_In_Place_Function --
4631 --------------------------------
4633 function Is_Build_In_Place_Function (E : Entity_Id) return Boolean is
4635 -- For now we test whether E denotes a function or access-to-function
4636 -- type whose result subtype is inherently limited. Later this test may
4637 -- be revised to allow composite nonlimited types. Functions with a
4638 -- foreign convention or whose result type has a foreign convention
4641 if Ekind (E) = E_Function
4642 or else Ekind (E) = E_Generic_Function
4643 or else (Ekind (E) = E_Subprogram_Type
4644 and then Etype (E) /= Standard_Void_Type)
4646 -- Note: If you have Convention (C) on an inherently limited type,
4647 -- you're on your own. That is, the C code will have to be carefully
4648 -- written to know about the Ada conventions.
4650 if Has_Foreign_Convention (E)
4651 or else Has_Foreign_Convention (Etype (E))
4655 -- If the return type is a limited interface it has to be treated
4656 -- as a return in place, even if the actual object is some non-
4657 -- limited descendant.
4659 elsif Is_Limited_Interface (Etype (E)) then
4663 return Is_Inherently_Limited_Type (Etype (E))
4664 and then Ada_Version >= Ada_05
4665 and then not Debug_Flag_Dot_L;
4671 end Is_Build_In_Place_Function;
4673 -------------------------------------
4674 -- Is_Build_In_Place_Function_Call --
4675 -------------------------------------
4677 function Is_Build_In_Place_Function_Call (N : Node_Id) return Boolean is
4678 Exp_Node : Node_Id := N;
4679 Function_Id : Entity_Id;
4682 -- Step past qualification or unchecked conversion (the latter can occur
4683 -- in cases of calls to 'Input).
4686 (Exp_Node, N_Qualified_Expression, N_Unchecked_Type_Conversion)
4688 Exp_Node := Expression (N);
4691 if Nkind (Exp_Node) /= N_Function_Call then
4695 if Is_Entity_Name (Name (Exp_Node)) then
4696 Function_Id := Entity (Name (Exp_Node));
4698 elsif Nkind (Name (Exp_Node)) = N_Explicit_Dereference then
4699 Function_Id := Etype (Name (Exp_Node));
4702 return Is_Build_In_Place_Function (Function_Id);
4704 end Is_Build_In_Place_Function_Call;
4706 ---------------------------------------
4707 -- Is_Build_In_Place_Function_Return --
4708 ---------------------------------------
4710 function Is_Build_In_Place_Function_Return (N : Node_Id) return Boolean is
4712 if Nkind_In (N, N_Simple_Return_Statement,
4713 N_Extended_Return_Statement)
4715 return Is_Build_In_Place_Function
4716 (Return_Applies_To (Return_Statement_Entity (N)));
4720 end Is_Build_In_Place_Function_Return;
4722 -----------------------
4723 -- Freeze_Subprogram --
4724 -----------------------
4726 procedure Freeze_Subprogram (N : Node_Id) is
4727 Loc : constant Source_Ptr := Sloc (N);
4729 procedure Register_Predefined_DT_Entry (Prim : Entity_Id);
4730 -- (Ada 2005): Register a predefined primitive in all the secondary
4731 -- dispatch tables of its primitive type.
4733 ----------------------------------
4734 -- Register_Predefined_DT_Entry --
4735 ----------------------------------
4737 procedure Register_Predefined_DT_Entry (Prim : Entity_Id) is
4738 Iface_DT_Ptr : Elmt_Id;
4739 Tagged_Typ : Entity_Id;
4740 Thunk_Id : Entity_Id;
4741 Thunk_Code : Node_Id;
4744 Tagged_Typ := Find_Dispatching_Type (Prim);
4746 if No (Access_Disp_Table (Tagged_Typ))
4747 or else not Has_Interfaces (Tagged_Typ)
4748 or else not RTE_Available (RE_Interface_Tag)
4749 or else Restriction_Active (No_Dispatching_Calls)
4754 -- Skip the first two access-to-dispatch-table pointers since they
4755 -- leads to the primary dispatch table (predefined DT and user
4756 -- defined DT). We are only concerned with the secondary dispatch
4757 -- table pointers. Note that the access-to- dispatch-table pointer
4758 -- corresponds to the first implemented interface retrieved below.
4761 Next_Elmt (Next_Elmt (First_Elmt (Access_Disp_Table (Tagged_Typ))));
4763 while Present (Iface_DT_Ptr)
4764 and then Ekind (Node (Iface_DT_Ptr)) = E_Constant
4766 pragma Assert (Has_Thunks (Node (Iface_DT_Ptr)));
4767 Expand_Interface_Thunk (Prim, Thunk_Id, Thunk_Code);
4769 if Present (Thunk_Code) then
4770 Insert_Actions_After (N, New_List (
4773 Build_Set_Predefined_Prim_Op_Address (Loc,
4775 New_Reference_To (Node (Next_Elmt (Iface_DT_Ptr)), Loc),
4776 Position => DT_Position (Prim),
4778 Unchecked_Convert_To (RTE (RE_Prim_Ptr),
4779 Make_Attribute_Reference (Loc,
4780 Prefix => New_Reference_To (Thunk_Id, Loc),
4781 Attribute_Name => Name_Unrestricted_Access))),
4783 Build_Set_Predefined_Prim_Op_Address (Loc,
4786 (Node (Next_Elmt (Next_Elmt (Next_Elmt (Iface_DT_Ptr)))),
4788 Position => DT_Position (Prim),
4790 Unchecked_Convert_To (RTE (RE_Prim_Ptr),
4791 Make_Attribute_Reference (Loc,
4792 Prefix => New_Reference_To (Prim, Loc),
4793 Attribute_Name => Name_Unrestricted_Access)))));
4796 -- Skip the tag of the predefined primitives dispatch table
4798 Next_Elmt (Iface_DT_Ptr);
4799 pragma Assert (Has_Thunks (Node (Iface_DT_Ptr)));
4801 -- Skip the tag of the no-thunks dispatch table
4803 Next_Elmt (Iface_DT_Ptr);
4804 pragma Assert (not Has_Thunks (Node (Iface_DT_Ptr)));
4806 -- Skip the tag of the predefined primitives no-thunks dispatch
4809 Next_Elmt (Iface_DT_Ptr);
4810 pragma Assert (not Has_Thunks (Node (Iface_DT_Ptr)));
4812 Next_Elmt (Iface_DT_Ptr);
4814 end Register_Predefined_DT_Entry;
4818 Subp : constant Entity_Id := Entity (N);
4820 -- Start of processing for Freeze_Subprogram
4823 -- We suppress the initialization of the dispatch table entry when
4824 -- VM_Target because the dispatching mechanism is handled internally
4827 if Is_Dispatching_Operation (Subp)
4828 and then not Is_Abstract_Subprogram (Subp)
4829 and then Present (DTC_Entity (Subp))
4830 and then Present (Scope (DTC_Entity (Subp)))
4831 and then VM_Target = No_VM
4832 and then not Restriction_Active (No_Dispatching_Calls)
4833 and then RTE_Available (RE_Tag)
4836 Typ : constant Entity_Id := Scope (DTC_Entity (Subp));
4839 -- Handle private overridden primitives
4841 if not Is_CPP_Class (Typ) then
4842 Check_Overriding_Operation (Subp);
4845 -- We assume that imported CPP primitives correspond with objects
4846 -- whose constructor is in the CPP side; therefore we don't need
4847 -- to generate code to register them in the dispatch table.
4849 if Is_CPP_Class (Typ) then
4852 -- Handle CPP primitives found in derivations of CPP_Class types.
4853 -- These primitives must have been inherited from some parent, and
4854 -- there is no need to register them in the dispatch table because
4855 -- Build_Inherit_Prims takes care of the initialization of these
4858 elsif Is_Imported (Subp)
4859 and then (Convention (Subp) = Convention_CPP
4860 or else Convention (Subp) = Convention_C)
4864 -- Generate code to register the primitive in non statically
4865 -- allocated dispatch tables
4867 elsif not Static_Dispatch_Tables
4869 Is_Library_Level_Tagged_Type (Scope (DTC_Entity (Subp)))
4871 -- When a primitive is frozen, enter its name in its dispatch
4874 if not Is_Interface (Typ)
4875 or else Present (Interface_Alias (Subp))
4877 if Is_Predefined_Dispatching_Operation (Subp) then
4878 Register_Predefined_DT_Entry (Subp);
4881 Register_Primitive (Loc,
4889 -- Mark functions that return by reference. Note that it cannot be part
4890 -- of the normal semantic analysis of the spec since the underlying
4891 -- returned type may not be known yet (for private types).
4894 Typ : constant Entity_Id := Etype (Subp);
4895 Utyp : constant Entity_Id := Underlying_Type (Typ);
4897 if Is_Inherently_Limited_Type (Typ) then
4898 Set_Returns_By_Ref (Subp);
4899 elsif Present (Utyp) and then CW_Or_Controlled_Type (Utyp) then
4900 Set_Returns_By_Ref (Subp);
4903 end Freeze_Subprogram;
4905 -------------------------------------------
4906 -- Make_Build_In_Place_Call_In_Allocator --
4907 -------------------------------------------
4909 procedure Make_Build_In_Place_Call_In_Allocator
4910 (Allocator : Node_Id;
4911 Function_Call : Node_Id)
4914 Func_Call : Node_Id := Function_Call;
4915 Function_Id : Entity_Id;
4916 Result_Subt : Entity_Id;
4917 Acc_Type : constant Entity_Id := Etype (Allocator);
4918 New_Allocator : Node_Id;
4919 Return_Obj_Access : Entity_Id;
4922 -- Step past qualification or unchecked conversion (the latter can occur
4923 -- in cases of calls to 'Input).
4925 if Nkind_In (Func_Call,
4926 N_Qualified_Expression,
4927 N_Unchecked_Type_Conversion)
4929 Func_Call := Expression (Func_Call);
4932 -- If the call has already been processed to add build-in-place actuals
4933 -- then return. This should not normally occur in an allocator context,
4934 -- but we add the protection as a defensive measure.
4936 if Is_Expanded_Build_In_Place_Call (Func_Call) then
4940 -- Mark the call as processed as a build-in-place call
4942 Set_Is_Expanded_Build_In_Place_Call (Func_Call);
4944 Loc := Sloc (Function_Call);
4946 if Is_Entity_Name (Name (Func_Call)) then
4947 Function_Id := Entity (Name (Func_Call));
4949 elsif Nkind (Name (Func_Call)) = N_Explicit_Dereference then
4950 Function_Id := Etype (Name (Func_Call));
4953 raise Program_Error;
4956 Result_Subt := Etype (Function_Id);
4958 -- When the result subtype is constrained, the return object must be
4959 -- allocated on the caller side, and access to it is passed to the
4962 -- Here and in related routines, we must examine the full view of the
4963 -- type, because the view at the point of call may differ from that
4964 -- that in the function body, and the expansion mechanism depends on
4965 -- the characteristics of the full view.
4967 if Is_Constrained (Underlying_Type (Result_Subt)) then
4969 -- Replace the initialized allocator of form "new T'(Func (...))"
4970 -- with an uninitialized allocator of form "new T", where T is the
4971 -- result subtype of the called function. The call to the function
4972 -- is handled separately further below.
4975 Make_Allocator (Loc, New_Reference_To (Result_Subt, Loc));
4977 Set_Storage_Pool (New_Allocator, Storage_Pool (Allocator));
4978 Set_Procedure_To_Call (New_Allocator, Procedure_To_Call (Allocator));
4979 Set_No_Initialization (New_Allocator);
4981 Rewrite (Allocator, New_Allocator);
4983 -- Create a new access object and initialize it to the result of the
4984 -- new uninitialized allocator.
4986 Return_Obj_Access :=
4987 Make_Defining_Identifier (Loc, New_Internal_Name ('R'));
4988 Set_Etype (Return_Obj_Access, Acc_Type);
4990 Insert_Action (Allocator,
4991 Make_Object_Declaration (Loc,
4992 Defining_Identifier => Return_Obj_Access,
4993 Object_Definition => New_Reference_To (Acc_Type, Loc),
4994 Expression => Relocate_Node (Allocator)));
4996 -- When the function has a controlling result, an allocation-form
4997 -- parameter must be passed indicating that the caller is allocating
4998 -- the result object. This is needed because such a function can be
4999 -- called as a dispatching operation and must be treated similarly
5000 -- to functions with unconstrained result subtypes.
5002 Add_Alloc_Form_Actual_To_Build_In_Place_Call
5003 (Func_Call, Function_Id, Alloc_Form => Caller_Allocation);
5005 Add_Final_List_Actual_To_Build_In_Place_Call
5006 (Func_Call, Function_Id, Acc_Type);
5008 Add_Task_Actuals_To_Build_In_Place_Call
5009 (Func_Call, Function_Id, Master_Actual => Master_Id (Acc_Type));
5011 -- Add an implicit actual to the function call that provides access
5012 -- to the allocated object. An unchecked conversion to the (specific)
5013 -- result subtype of the function is inserted to handle cases where
5014 -- the access type of the allocator has a class-wide designated type.
5016 Add_Access_Actual_To_Build_In_Place_Call
5019 Make_Unchecked_Type_Conversion (Loc,
5020 Subtype_Mark => New_Reference_To (Result_Subt, Loc),
5022 Make_Explicit_Dereference (Loc,
5023 Prefix => New_Reference_To (Return_Obj_Access, Loc))));
5025 -- When the result subtype is unconstrained, the function itself must
5026 -- perform the allocation of the return object, so we pass parameters
5027 -- indicating that. We don't yet handle the case where the allocation
5028 -- must be done in a user-defined storage pool, which will require
5029 -- passing another actual or two to provide allocation/deallocation
5034 -- Pass an allocation parameter indicating that the function should
5035 -- allocate its result on the heap.
5037 Add_Alloc_Form_Actual_To_Build_In_Place_Call
5038 (Func_Call, Function_Id, Alloc_Form => Global_Heap);
5040 Add_Final_List_Actual_To_Build_In_Place_Call
5041 (Func_Call, Function_Id, Acc_Type);
5043 Add_Task_Actuals_To_Build_In_Place_Call
5044 (Func_Call, Function_Id, Master_Actual => Master_Id (Acc_Type));
5046 -- The caller does not provide the return object in this case, so we
5047 -- have to pass null for the object access actual.
5049 Add_Access_Actual_To_Build_In_Place_Call
5050 (Func_Call, Function_Id, Return_Object => Empty);
5053 -- Finally, replace the allocator node with a reference to the result
5054 -- of the function call itself (which will effectively be an access
5055 -- to the object created by the allocator).
5057 Rewrite (Allocator, Make_Reference (Loc, Relocate_Node (Function_Call)));
5058 Analyze_And_Resolve (Allocator, Acc_Type);
5059 end Make_Build_In_Place_Call_In_Allocator;
5061 ---------------------------------------------------
5062 -- Make_Build_In_Place_Call_In_Anonymous_Context --
5063 ---------------------------------------------------
5065 procedure Make_Build_In_Place_Call_In_Anonymous_Context
5066 (Function_Call : Node_Id)
5069 Func_Call : Node_Id := Function_Call;
5070 Function_Id : Entity_Id;
5071 Result_Subt : Entity_Id;
5072 Return_Obj_Id : Entity_Id;
5073 Return_Obj_Decl : Entity_Id;
5076 -- Step past qualification or unchecked conversion (the latter can occur
5077 -- in cases of calls to 'Input).
5079 if Nkind_In (Func_Call, N_Qualified_Expression,
5080 N_Unchecked_Type_Conversion)
5082 Func_Call := Expression (Func_Call);
5085 -- If the call has already been processed to add build-in-place actuals
5086 -- then return. One place this can occur is for calls to build-in-place
5087 -- functions that occur within a call to a protected operation, where
5088 -- due to rewriting and expansion of the protected call there can be
5089 -- more than one call to Expand_Actuals for the same set of actuals.
5091 if Is_Expanded_Build_In_Place_Call (Func_Call) then
5095 -- Mark the call as processed as a build-in-place call
5097 Set_Is_Expanded_Build_In_Place_Call (Func_Call);
5099 Loc := Sloc (Function_Call);
5101 if Is_Entity_Name (Name (Func_Call)) then
5102 Function_Id := Entity (Name (Func_Call));
5104 elsif Nkind (Name (Func_Call)) = N_Explicit_Dereference then
5105 Function_Id := Etype (Name (Func_Call));
5108 raise Program_Error;
5111 Result_Subt := Etype (Function_Id);
5113 -- When the result subtype is constrained, an object of the subtype is
5114 -- declared and an access value designating it is passed as an actual.
5116 if Is_Constrained (Underlying_Type (Result_Subt)) then
5118 -- Create a temporary object to hold the function result
5121 Make_Defining_Identifier (Loc,
5122 Chars => New_Internal_Name ('R'));
5123 Set_Etype (Return_Obj_Id, Result_Subt);
5126 Make_Object_Declaration (Loc,
5127 Defining_Identifier => Return_Obj_Id,
5128 Aliased_Present => True,
5129 Object_Definition => New_Reference_To (Result_Subt, Loc));
5131 Set_No_Initialization (Return_Obj_Decl);
5133 Insert_Action (Func_Call, Return_Obj_Decl);
5135 -- When the function has a controlling result, an allocation-form
5136 -- parameter must be passed indicating that the caller is allocating
5137 -- the result object. This is needed because such a function can be
5138 -- called as a dispatching operation and must be treated similarly
5139 -- to functions with unconstrained result subtypes.
5141 Add_Alloc_Form_Actual_To_Build_In_Place_Call
5142 (Func_Call, Function_Id, Alloc_Form => Caller_Allocation);
5144 Add_Final_List_Actual_To_Build_In_Place_Call
5145 (Func_Call, Function_Id, Acc_Type => Empty);
5147 Add_Task_Actuals_To_Build_In_Place_Call
5148 (Func_Call, Function_Id, Make_Identifier (Loc, Name_uMaster));
5150 -- Add an implicit actual to the function call that provides access
5151 -- to the caller's return object.
5153 Add_Access_Actual_To_Build_In_Place_Call
5154 (Func_Call, Function_Id, New_Reference_To (Return_Obj_Id, Loc));
5156 -- When the result subtype is unconstrained, the function must allocate
5157 -- the return object in the secondary stack, so appropriate implicit
5158 -- parameters are added to the call to indicate that. A transient
5159 -- scope is established to ensure eventual cleanup of the result.
5163 -- Pass an allocation parameter indicating that the function should
5164 -- allocate its result on the secondary stack.
5166 Add_Alloc_Form_Actual_To_Build_In_Place_Call
5167 (Func_Call, Function_Id, Alloc_Form => Secondary_Stack);
5169 Add_Final_List_Actual_To_Build_In_Place_Call
5170 (Func_Call, Function_Id, Acc_Type => Empty);
5172 Add_Task_Actuals_To_Build_In_Place_Call
5173 (Func_Call, Function_Id, Make_Identifier (Loc, Name_uMaster));
5175 -- Pass a null value to the function since no return object is
5176 -- available on the caller side.
5178 Add_Access_Actual_To_Build_In_Place_Call
5179 (Func_Call, Function_Id, Empty);
5181 Establish_Transient_Scope (Func_Call, Sec_Stack => True);
5183 end Make_Build_In_Place_Call_In_Anonymous_Context;
5185 ---------------------------------------------------
5186 -- Make_Build_In_Place_Call_In_Assignment --
5187 ---------------------------------------------------
5189 procedure Make_Build_In_Place_Call_In_Assignment
5191 Function_Call : Node_Id)
5193 Lhs : constant Node_Id := Name (Assign);
5195 Func_Call : Node_Id := Function_Call;
5196 Function_Id : Entity_Id;
5197 Result_Subt : Entity_Id;
5198 Ref_Type : Entity_Id;
5199 Ptr_Typ_Decl : Node_Id;
5204 -- Step past qualification or unchecked conversion (the latter can occur
5205 -- in cases of calls to 'Input).
5207 if Nkind_In (Func_Call, N_Qualified_Expression,
5208 N_Unchecked_Type_Conversion)
5210 Func_Call := Expression (Func_Call);
5213 -- If the call has already been processed to add build-in-place actuals
5214 -- then return. This should not normally occur in an assignment context,
5215 -- but we add the protection as a defensive measure.
5217 if Is_Expanded_Build_In_Place_Call (Func_Call) then
5221 -- Mark the call as processed as a build-in-place call
5223 Set_Is_Expanded_Build_In_Place_Call (Func_Call);
5225 Loc := Sloc (Function_Call);
5227 if Is_Entity_Name (Name (Func_Call)) then
5228 Function_Id := Entity (Name (Func_Call));
5230 elsif Nkind (Name (Func_Call)) = N_Explicit_Dereference then
5231 Function_Id := Etype (Name (Func_Call));
5234 raise Program_Error;
5237 Result_Subt := Etype (Function_Id);
5239 -- When the result subtype is unconstrained, an additional actual must
5240 -- be passed to indicate that the caller is providing the return object.
5241 -- This parameter must also be passed when the called function has a
5242 -- controlling result, because dispatching calls to the function needs
5243 -- to be treated effectively the same as calls to class-wide functions.
5245 Add_Alloc_Form_Actual_To_Build_In_Place_Call
5246 (Func_Call, Function_Id, Alloc_Form => Caller_Allocation);
5248 -- If Lhs is a selected component, then pass it along so that its prefix
5249 -- object will be used as the source of the finalization list.
5251 if Nkind (Lhs) = N_Selected_Component then
5252 Add_Final_List_Actual_To_Build_In_Place_Call
5253 (Func_Call, Function_Id, Acc_Type => Empty, Sel_Comp => Lhs);
5255 Add_Final_List_Actual_To_Build_In_Place_Call
5256 (Func_Call, Function_Id, Acc_Type => Empty);
5259 Add_Task_Actuals_To_Build_In_Place_Call
5260 (Func_Call, Function_Id, Make_Identifier (Loc, Name_uMaster));
5262 -- Add an implicit actual to the function call that provides access to
5263 -- the caller's return object.
5265 Add_Access_Actual_To_Build_In_Place_Call
5268 Make_Unchecked_Type_Conversion (Loc,
5269 Subtype_Mark => New_Reference_To (Result_Subt, Loc),
5270 Expression => Relocate_Node (Lhs)));
5272 -- Create an access type designating the function's result subtype
5275 Make_Defining_Identifier (Loc, New_Internal_Name ('A'));
5278 Make_Full_Type_Declaration (Loc,
5279 Defining_Identifier => Ref_Type,
5281 Make_Access_To_Object_Definition (Loc,
5282 All_Present => True,
5283 Subtype_Indication =>
5284 New_Reference_To (Result_Subt, Loc)));
5286 Insert_After_And_Analyze (Assign, Ptr_Typ_Decl);
5288 -- Finally, create an access object initialized to a reference to the
5292 Make_Defining_Identifier (Loc,
5293 Chars => New_Internal_Name ('R'));
5294 Set_Etype (Def_Id, Ref_Type);
5297 Make_Reference (Loc,
5298 Prefix => Relocate_Node (Func_Call));
5300 Insert_After_And_Analyze (Ptr_Typ_Decl,
5301 Make_Object_Declaration (Loc,
5302 Defining_Identifier => Def_Id,
5303 Object_Definition => New_Reference_To (Ref_Type, Loc),
5304 Expression => New_Expr));
5306 Rewrite (Assign, Make_Null_Statement (Loc));
5307 end Make_Build_In_Place_Call_In_Assignment;
5309 ----------------------------------------------------
5310 -- Make_Build_In_Place_Call_In_Object_Declaration --
5311 ----------------------------------------------------
5313 procedure Make_Build_In_Place_Call_In_Object_Declaration
5314 (Object_Decl : Node_Id;
5315 Function_Call : Node_Id)
5318 Obj_Def_Id : constant Entity_Id :=
5319 Defining_Identifier (Object_Decl);
5321 Func_Call : Node_Id := Function_Call;
5322 Function_Id : Entity_Id;
5323 Result_Subt : Entity_Id;
5324 Caller_Object : Node_Id;
5325 Call_Deref : Node_Id;
5326 Ref_Type : Entity_Id;
5327 Ptr_Typ_Decl : Node_Id;
5330 Enclosing_Func : Entity_Id;
5331 Pass_Caller_Acc : Boolean := False;
5334 -- Step past qualification or unchecked conversion (the latter can occur
5335 -- in cases of calls to 'Input).
5337 if Nkind_In (Func_Call, N_Qualified_Expression,
5338 N_Unchecked_Type_Conversion)
5340 Func_Call := Expression (Func_Call);
5343 -- If the call has already been processed to add build-in-place actuals
5344 -- then return. This should not normally occur in an object declaration,
5345 -- but we add the protection as a defensive measure.
5347 if Is_Expanded_Build_In_Place_Call (Func_Call) then
5351 -- Mark the call as processed as a build-in-place call
5353 Set_Is_Expanded_Build_In_Place_Call (Func_Call);
5355 Loc := Sloc (Function_Call);
5357 if Is_Entity_Name (Name (Func_Call)) then
5358 Function_Id := Entity (Name (Func_Call));
5360 elsif Nkind (Name (Func_Call)) = N_Explicit_Dereference then
5361 Function_Id := Etype (Name (Func_Call));
5364 raise Program_Error;
5367 Result_Subt := Etype (Function_Id);
5369 -- In the constrained case, add an implicit actual to the function call
5370 -- that provides access to the declared object. An unchecked conversion
5371 -- to the (specific) result type of the function is inserted to handle
5372 -- the case where the object is declared with a class-wide type.
5374 if Is_Constrained (Underlying_Type (Result_Subt)) then
5376 Make_Unchecked_Type_Conversion (Loc,
5377 Subtype_Mark => New_Reference_To (Result_Subt, Loc),
5378 Expression => New_Reference_To (Obj_Def_Id, Loc));
5380 -- When the function has a controlling result, an allocation-form
5381 -- parameter must be passed indicating that the caller is allocating
5382 -- the result object. This is needed because such a function can be
5383 -- called as a dispatching operation and must be treated similarly
5384 -- to functions with unconstrained result subtypes.
5386 Add_Alloc_Form_Actual_To_Build_In_Place_Call
5387 (Func_Call, Function_Id, Alloc_Form => Caller_Allocation);
5389 -- If the function's result subtype is unconstrained and the object is
5390 -- a return object of an enclosing build-in-place function, then the
5391 -- implicit build-in-place parameters of the enclosing function must be
5392 -- passed along to the called function.
5394 elsif Nkind (Parent (Object_Decl)) = N_Extended_Return_Statement then
5395 Pass_Caller_Acc := True;
5397 Enclosing_Func := Enclosing_Subprogram (Obj_Def_Id);
5399 -- If the enclosing function has a constrained result type, then
5400 -- caller allocation will be used.
5402 if Is_Constrained (Etype (Enclosing_Func)) then
5403 Add_Alloc_Form_Actual_To_Build_In_Place_Call
5404 (Func_Call, Function_Id, Alloc_Form => Caller_Allocation);
5406 -- Otherwise, when the enclosing function has an unconstrained result
5407 -- type, the BIP_Alloc_Form formal of the enclosing function must be
5408 -- passed along to the callee.
5411 Add_Alloc_Form_Actual_To_Build_In_Place_Call
5416 (Build_In_Place_Formal (Enclosing_Func, BIP_Alloc_Form),
5420 -- Retrieve the BIPacc formal from the enclosing function and convert
5421 -- it to the access type of the callee's BIP_Object_Access formal.
5424 Make_Unchecked_Type_Conversion (Loc,
5428 (Build_In_Place_Formal (Function_Id, BIP_Object_Access)),
5432 (Build_In_Place_Formal (Enclosing_Func, BIP_Object_Access),
5435 -- In other unconstrained cases, pass an indication to do the allocation
5436 -- on the secondary stack and set Caller_Object to Empty so that a null
5437 -- value will be passed for the caller's object address. A transient
5438 -- scope is established to ensure eventual cleanup of the result.
5441 Add_Alloc_Form_Actual_To_Build_In_Place_Call
5444 Alloc_Form => Secondary_Stack);
5445 Caller_Object := Empty;
5447 Establish_Transient_Scope (Object_Decl, Sec_Stack => True);
5450 Add_Final_List_Actual_To_Build_In_Place_Call
5451 (Func_Call, Function_Id, Acc_Type => Empty);
5453 if Nkind (Parent (Object_Decl)) = N_Extended_Return_Statement
5454 and then Has_Task (Result_Subt)
5456 Enclosing_Func := Enclosing_Subprogram (Obj_Def_Id);
5458 -- Here we're passing along the master that was passed in to this
5461 Add_Task_Actuals_To_Build_In_Place_Call
5462 (Func_Call, Function_Id,
5465 (Build_In_Place_Formal (Enclosing_Func, BIP_Master), Loc));
5468 Add_Task_Actuals_To_Build_In_Place_Call
5469 (Func_Call, Function_Id, Make_Identifier (Loc, Name_uMaster));
5472 Add_Access_Actual_To_Build_In_Place_Call
5473 (Func_Call, Function_Id, Caller_Object, Is_Access => Pass_Caller_Acc);
5475 -- Create an access type designating the function's result subtype
5478 Make_Defining_Identifier (Loc, New_Internal_Name ('A'));
5481 Make_Full_Type_Declaration (Loc,
5482 Defining_Identifier => Ref_Type,
5484 Make_Access_To_Object_Definition (Loc,
5485 All_Present => True,
5486 Subtype_Indication =>
5487 New_Reference_To (Result_Subt, Loc)));
5489 -- The access type and its accompanying object must be inserted after
5490 -- the object declaration in the constrained case, so that the function
5491 -- call can be passed access to the object. In the unconstrained case,
5492 -- the access type and object must be inserted before the object, since
5493 -- the object declaration is rewritten to be a renaming of a dereference
5494 -- of the access object.
5496 if Is_Constrained (Underlying_Type (Result_Subt)) then
5497 Insert_After_And_Analyze (Object_Decl, Ptr_Typ_Decl);
5499 Insert_Before_And_Analyze (Object_Decl, Ptr_Typ_Decl);
5502 -- Finally, create an access object initialized to a reference to the
5506 Make_Defining_Identifier (Loc,
5507 Chars => New_Internal_Name ('R'));
5508 Set_Etype (Def_Id, Ref_Type);
5511 Make_Reference (Loc,
5512 Prefix => Relocate_Node (Func_Call));
5514 Insert_After_And_Analyze (Ptr_Typ_Decl,
5515 Make_Object_Declaration (Loc,
5516 Defining_Identifier => Def_Id,
5517 Object_Definition => New_Reference_To (Ref_Type, Loc),
5518 Expression => New_Expr));
5520 if Is_Constrained (Underlying_Type (Result_Subt)) then
5521 Set_Expression (Object_Decl, Empty);
5522 Set_No_Initialization (Object_Decl);
5524 -- In case of an unconstrained result subtype, rewrite the object
5525 -- declaration as an object renaming where the renamed object is a
5526 -- dereference of <function_Call>'reference:
5528 -- Obj : Subt renames <function_call>'Ref.all;
5532 Make_Explicit_Dereference (Loc,
5533 Prefix => New_Reference_To (Def_Id, Loc));
5535 Rewrite (Object_Decl,
5536 Make_Object_Renaming_Declaration (Loc,
5537 Defining_Identifier => Make_Defining_Identifier (Loc,
5538 New_Internal_Name ('D')),
5539 Access_Definition => Empty,
5540 Subtype_Mark => New_Occurrence_Of (Result_Subt, Loc),
5541 Name => Call_Deref));
5543 Set_Renamed_Object (Defining_Identifier (Object_Decl), Call_Deref);
5545 Analyze (Object_Decl);
5547 -- Replace the internal identifier of the renaming declaration's
5548 -- entity with identifier of the original object entity. We also have
5549 -- to exchange the entities containing their defining identifiers to
5550 -- ensure the correct replacement of the object declaration by the
5551 -- object renaming declaration to avoid homograph conflicts (since
5552 -- the object declaration's defining identifier was already entered
5553 -- in current scope). The Next_Entity links of the two entities also
5554 -- have to be swapped since the entities are part of the return
5555 -- scope's entity list and the list structure would otherwise be
5559 Renaming_Def_Id : constant Entity_Id :=
5560 Defining_Identifier (Object_Decl);
5561 Next_Entity_Temp : constant Entity_Id :=
5562 Next_Entity (Renaming_Def_Id);
5564 Set_Chars (Renaming_Def_Id, Chars (Obj_Def_Id));
5566 -- Swap next entity links in preparation for exchanging entities
5568 Set_Next_Entity (Renaming_Def_Id, Next_Entity (Obj_Def_Id));
5569 Set_Next_Entity (Obj_Def_Id, Next_Entity_Temp);
5571 Exchange_Entities (Renaming_Def_Id, Obj_Def_Id);
5575 -- If the object entity has a class-wide Etype, then we need to change
5576 -- it to the result subtype of the function call, because otherwise the
5577 -- object will be class-wide without an explicit initialization and
5578 -- won't be allocated properly by the back end. It seems unclean to make
5579 -- such a revision to the type at this point, and we should try to
5580 -- improve this treatment when build-in-place functions with class-wide
5581 -- results are implemented. ???
5583 if Is_Class_Wide_Type (Etype (Defining_Identifier (Object_Decl))) then
5584 Set_Etype (Defining_Identifier (Object_Decl), Result_Subt);
5586 end Make_Build_In_Place_Call_In_Object_Declaration;