1------------------------------------------------------------------------------
2--                                                                          --
3--                         GNAT COMPILER COMPONENTS                         --
4--                                                                          --
5--                             E X P _ I N T R                              --
6--                                                                          --
7--                                 B o d y                                  --
8--                                                                          --
9--          Copyright (C) 1992-2013, Free Software Foundation, Inc.         --
10--                                                                          --
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.          --
20--                                                                          --
21-- GNAT was originally developed  by the GNAT team at  New York University. --
22-- Extensive contributions were provided by Ada Core Technologies Inc.      --
23--                                                                          --
24------------------------------------------------------------------------------
25
26with Atree;    use Atree;
27with Checks;   use Checks;
28with Einfo;    use Einfo;
29with Elists;   use Elists;
30with Errout;   use Errout;
31with Exp_Atag; use Exp_Atag;
32with Exp_Ch4;  use Exp_Ch4;
33with Exp_Ch7;  use Exp_Ch7;
34with Exp_Ch11; use Exp_Ch11;
35with Exp_Code; use Exp_Code;
36with Exp_Fixd; use Exp_Fixd;
37with Exp_Util; use Exp_Util;
38with Freeze;   use Freeze;
39with Namet;    use Namet;
40with Nmake;    use Nmake;
41with Nlists;   use Nlists;
42with Opt;      use Opt;
43with Restrict; use Restrict;
44with Rident;   use Rident;
45with Rtsfind;  use Rtsfind;
46with Sem;      use Sem;
47with Sem_Aux;  use Sem_Aux;
48with Sem_Eval; use Sem_Eval;
49with Sem_Res;  use Sem_Res;
50with Sem_Type; use Sem_Type;
51with Sem_Util; use Sem_Util;
52with Sinfo;    use Sinfo;
53with Sinput;   use Sinput;
54with Snames;   use Snames;
55with Stand;    use Stand;
56with Stringt;  use Stringt;
57with Targparm; use Targparm;
58with Tbuild;   use Tbuild;
59with Uintp;    use Uintp;
60with Urealp;   use Urealp;
61
62package body Exp_Intr is
63
64   -----------------------
65   -- Local Subprograms --
66   -----------------------
67
68   procedure Expand_Binary_Operator_Call (N : Node_Id);
69   --  Expand a call to an intrinsic arithmetic operator when the operand
70   --  types or sizes are not identical.
71
72   procedure Expand_Is_Negative (N : Node_Id);
73   --  Expand a call to the intrinsic Is_Negative function
74
75   procedure Expand_Dispatching_Constructor_Call (N : Node_Id);
76   --  Expand a call to an instantiation of Generic_Dispatching_Constructor
77   --  into a dispatching call to the actual subprogram associated with the
78   --  Constructor formal subprogram, passing it the Parameters actual of
79   --  the call to the instantiation and dispatching based on call's Tag
80   --  parameter.
81
82   procedure Expand_Exception_Call (N : Node_Id; Ent : RE_Id);
83   --  Expand a call to Exception_Information/Message/Name. The first
84   --  parameter, N, is the node for the function call, and Ent is the
85   --  entity for the corresponding routine in the Ada.Exceptions package.
86
87   procedure Expand_Import_Call (N : Node_Id);
88   --  Expand a call to Import_Address/Longest_Integer/Value. The parameter
89   --  N is the node for the function call.
90
91   procedure Expand_Shift (N : Node_Id; E : Entity_Id; K : Node_Kind);
92   --  Expand an intrinsic shift operation, N and E are from the call to
93   --  Expand_Intrinsic_Call (call node and subprogram spec entity) and
94   --  K is the kind for the shift node
95
96   procedure Expand_Unc_Conversion (N : Node_Id; E : Entity_Id);
97   --  Expand a call to an instantiation of Unchecked_Conversion into a node
98   --  N_Unchecked_Type_Conversion.
99
100   procedure Expand_Unc_Deallocation (N : Node_Id);
101   --  Expand a call to an instantiation of Unchecked_Deallocation into a node
102   --  N_Free_Statement and appropriate context.
103
104   procedure Expand_To_Address (N : Node_Id);
105   procedure Expand_To_Pointer (N : Node_Id);
106   --  Expand a call to corresponding function, declared in an instance of
107   --  System.Address_To_Access_Conversions.
108
109   procedure Expand_Source_Info (N : Node_Id; Nam : Name_Id);
110   --  Rewrite the node by the appropriate string or positive constant.
111   --  Nam can be one of the following:
112   --    Name_File             - expand string that is the name of source file
113   --    Name_Line             - expand integer line number
114   --    Name_Source_Location  - expand string of form file:line
115   --    Name_Enclosing_Entity - expand string  with name of enclosing entity
116
117   ---------------------------------
118   -- Expand_Binary_Operator_Call --
119   ---------------------------------
120
121   procedure Expand_Binary_Operator_Call (N : Node_Id) is
122      T1  : constant Entity_Id := Underlying_Type (Etype (Left_Opnd  (N)));
123      T2  : constant Entity_Id := Underlying_Type (Etype (Right_Opnd (N)));
124      TR  : constant Entity_Id := Etype (N);
125      T3  : Entity_Id;
126      Res : Node_Id;
127
128      Siz : constant Uint := UI_Max (RM_Size (T1), RM_Size (T2));
129      --  Maximum of operand sizes
130
131   begin
132      --  Nothing to do if the operands have the same modular type
133
134      if Base_Type (T1) = Base_Type (T2)
135        and then Is_Modular_Integer_Type (T1)
136      then
137         return;
138      end if;
139
140      --  Use Unsigned_32 for sizes of 32 or below, else Unsigned_64
141
142      if Siz > 32 then
143         T3 := RTE (RE_Unsigned_64);
144      else
145         T3 := RTE (RE_Unsigned_32);
146      end if;
147
148      --  Copy operator node, and reset type and entity fields, for
149      --  subsequent reanalysis.
150
151      Res := New_Copy (N);
152      Set_Etype (Res, T3);
153
154      case Nkind (N) is
155         when N_Op_And =>
156            Set_Entity (Res, Standard_Op_And);
157         when N_Op_Or =>
158            Set_Entity (Res, Standard_Op_Or);
159         when N_Op_Xor =>
160            Set_Entity (Res, Standard_Op_Xor);
161         when others =>
162            raise Program_Error;
163      end case;
164
165      --  Convert operands to large enough intermediate type
166
167      Set_Left_Opnd (Res,
168        Unchecked_Convert_To (T3, Relocate_Node (Left_Opnd (N))));
169      Set_Right_Opnd (Res,
170        Unchecked_Convert_To (T3, Relocate_Node (Right_Opnd (N))));
171
172      --  Analyze and resolve result formed by conversion to target type
173
174      Rewrite (N, Unchecked_Convert_To (TR, Res));
175      Analyze_And_Resolve (N, TR);
176   end Expand_Binary_Operator_Call;
177
178   -----------------------------------------
179   -- Expand_Dispatching_Constructor_Call --
180   -----------------------------------------
181
182   --  Transform a call to an instantiation of Generic_Dispatching_Constructor
183   --  of the form:
184
185   --     GDC_Instance (The_Tag, Parameters'Access)
186
187   --  to a class-wide conversion of a dispatching call to the actual
188   --  associated with the formal subprogram Construct, designating The_Tag
189   --  as the controlling tag of the call:
190
191   --     T'Class (Construct'Actual (Params)) -- Controlling tag is The_Tag
192
193   --  which will eventually be expanded to the following:
194
195   --     T'Class (The_Tag.all (Construct'Actual'Index).all (Params))
196
197   --  A class-wide membership test is also generated, preceding the call, to
198   --  ensure that the controlling tag denotes a type in T'Class.
199
200   procedure Expand_Dispatching_Constructor_Call (N : Node_Id) is
201      Loc        : constant Source_Ptr := Sloc (N);
202      Tag_Arg    : constant Node_Id    := First_Actual (N);
203      Param_Arg  : constant Node_Id    := Next_Actual (Tag_Arg);
204      Subp_Decl  : constant Node_Id    := Parent (Parent (Entity (Name (N))));
205      Inst_Pkg   : constant Node_Id    := Parent (Subp_Decl);
206      Act_Rename : Node_Id;
207      Act_Constr : Entity_Id;
208      Iface_Tag  : Node_Id := Empty;
209      Cnstr_Call : Node_Id;
210      Result_Typ : Entity_Id;
211
212   begin
213      --  Remove side effects from tag argument early, before rewriting
214      --  the dispatching constructor call, as Remove_Side_Effects relies
215      --  on Tag_Arg's Parent link properly attached to the tree (once the
216      --  call is rewritten, the Parent is inconsistent as it points to the
217      --  rewritten node, which is not the syntactic parent of the Tag_Arg
218      --  anymore).
219
220      Remove_Side_Effects (Tag_Arg);
221
222      --  The subprogram is the third actual in the instantiation, and is
223      --  retrieved from the corresponding renaming declaration. However,
224      --  freeze nodes may appear before, so we retrieve the declaration
225      --  with an explicit loop.
226
227      Act_Rename := First (Visible_Declarations (Inst_Pkg));
228      while Nkind (Act_Rename) /= N_Subprogram_Renaming_Declaration loop
229         Next (Act_Rename);
230      end loop;
231
232      Act_Constr := Entity (Name (Act_Rename));
233      Result_Typ := Class_Wide_Type (Etype (Act_Constr));
234
235      if Is_Interface (Etype (Act_Constr)) then
236
237         --  If the result type is not known to be a parent of Tag_Arg then we
238         --  need to locate the tag of the secondary dispatch table.
239
240         if not Is_Ancestor (Etype (Result_Typ), Etype (Tag_Arg),
241                             Use_Full_View => True)
242           and then Tagged_Type_Expansion
243         then
244            --  Obtain the reference to the Ada.Tags service before generating
245            --  the Object_Declaration node to ensure that if this service is
246            --  not available in the runtime then we generate a clear error.
247
248            declare
249               Fname : constant Node_Id :=
250                         New_Reference_To (RTE (RE_Secondary_Tag), Loc);
251
252            begin
253               pragma Assert (not Is_Interface (Etype (Tag_Arg)));
254
255               Iface_Tag :=
256                 Make_Object_Declaration (Loc,
257                   Defining_Identifier => Make_Temporary (Loc, 'V'),
258                   Object_Definition   =>
259                     New_Reference_To (RTE (RE_Tag), Loc),
260                   Expression          =>
261                     Make_Function_Call (Loc,
262                       Name                   => Fname,
263                       Parameter_Associations => New_List (
264                         Relocate_Node (Tag_Arg),
265                         New_Reference_To
266                           (Node (First_Elmt (Access_Disp_Table
267                                               (Etype (Etype (Act_Constr))))),
268                            Loc))));
269               Insert_Action (N, Iface_Tag);
270            end;
271         end if;
272      end if;
273
274      --  Create the call to the actual Constructor function
275
276      Cnstr_Call :=
277        Make_Function_Call (Loc,
278          Name                   => New_Occurrence_Of (Act_Constr, Loc),
279          Parameter_Associations => New_List (Relocate_Node (Param_Arg)));
280
281      --  Establish its controlling tag from the tag passed to the instance
282      --  The tag may be given by a function call, in which case a temporary
283      --  should be generated now, to prevent out-of-order insertions during
284      --  the expansion of that call when stack-checking is enabled.
285
286      if Present (Iface_Tag) then
287         Set_Controlling_Argument (Cnstr_Call,
288           New_Occurrence_Of (Defining_Identifier (Iface_Tag), Loc));
289      else
290         Set_Controlling_Argument (Cnstr_Call,
291           Relocate_Node (Tag_Arg));
292      end if;
293
294      --  Rewrite and analyze the call to the instance as a class-wide
295      --  conversion of the call to the actual constructor.
296
297      Rewrite (N, Convert_To (Result_Typ, Cnstr_Call));
298      Analyze_And_Resolve (N, Etype (Act_Constr));
299
300      --  Do not generate a run-time check on the built object if tag
301      --  checks are suppressed for the result type or VM_Target /= No_VM
302
303      if Tag_Checks_Suppressed (Etype (Result_Typ))
304        or else not Tagged_Type_Expansion
305      then
306         null;
307
308      --  Generate a class-wide membership test to ensure that the call's tag
309      --  argument denotes a type within the class. We must keep separate the
310      --  case in which the Result_Type of the constructor function is a tagged
311      --  type from the case in which it is an abstract interface because the
312      --  run-time subprogram required to check these cases differ (and have
313      --  one difference in their parameters profile).
314
315      --  Call CW_Membership if the Result_Type is a tagged type to look for
316      --  the tag in the table of ancestor tags.
317
318      elsif not Is_Interface (Result_Typ) then
319         declare
320            Obj_Tag_Node : Node_Id := New_Copy_Tree (Tag_Arg);
321            CW_Test_Node : Node_Id;
322
323         begin
324            Build_CW_Membership (Loc,
325              Obj_Tag_Node => Obj_Tag_Node,
326              Typ_Tag_Node =>
327                New_Reference_To (
328                   Node (First_Elmt (Access_Disp_Table (
329                                       Root_Type (Result_Typ)))), Loc),
330              Related_Nod => N,
331              New_Node    => CW_Test_Node);
332
333            Insert_Action (N,
334              Make_Implicit_If_Statement (N,
335                Condition =>
336                  Make_Op_Not (Loc, CW_Test_Node),
337                Then_Statements =>
338                  New_List (Make_Raise_Statement (Loc,
339                              New_Occurrence_Of (RTE (RE_Tag_Error), Loc)))));
340         end;
341
342      --  Call IW_Membership test if the Result_Type is an abstract interface
343      --  to look for the tag in the table of interface tags.
344
345      else
346         Insert_Action (N,
347           Make_Implicit_If_Statement (N,
348             Condition =>
349               Make_Op_Not (Loc,
350                 Make_Function_Call (Loc,
351                    Name => New_Occurrence_Of (RTE (RE_IW_Membership), Loc),
352                    Parameter_Associations => New_List (
353                      Make_Attribute_Reference (Loc,
354                        Prefix         => New_Copy_Tree (Tag_Arg),
355                        Attribute_Name => Name_Address),
356
357                      New_Reference_To (
358                        Node (First_Elmt (Access_Disp_Table (
359                                            Root_Type (Result_Typ)))), Loc)))),
360             Then_Statements =>
361               New_List (
362                 Make_Raise_Statement (Loc,
363                   Name => New_Occurrence_Of (RTE (RE_Tag_Error), Loc)))));
364      end if;
365   end Expand_Dispatching_Constructor_Call;
366
367   ---------------------------
368   -- Expand_Exception_Call --
369   ---------------------------
370
371   --  If the function call is not within an exception handler, then the call
372   --  is replaced by a null string. Otherwise the appropriate routine in
373   --  Ada.Exceptions is called passing the choice parameter specification
374   --  from the enclosing handler. If the enclosing handler lacks a choice
375   --  parameter, then one is supplied.
376
377   procedure Expand_Exception_Call (N : Node_Id; Ent : RE_Id) is
378      Loc : constant Source_Ptr := Sloc (N);
379      P   : Node_Id;
380      E   : Entity_Id;
381
382   begin
383      --  Climb up parents to see if we are in exception handler
384
385      P := Parent (N);
386      loop
387         --  Case of not in exception handler, replace by null string
388
389         if No (P) then
390            Rewrite (N,
391              Make_String_Literal (Loc,
392                Strval => ""));
393            exit;
394
395         --  Case of in exception handler
396
397         elsif Nkind (P) = N_Exception_Handler then
398
399            --  Handler cannot be used for a local raise, and furthermore, this
400            --  is a violation of the No_Exception_Propagation restriction.
401
402            Set_Local_Raise_Not_OK (P);
403            Check_Restriction (No_Exception_Propagation, N);
404
405            --  If no choice parameter present, then put one there. Note that
406            --  we do not need to put it on the entity chain, since no one will
407            --  be referencing it by normal visibility methods.
408
409            if No (Choice_Parameter (P)) then
410               E := Make_Temporary (Loc, 'E');
411               Set_Choice_Parameter (P, E);
412               Set_Ekind (E, E_Variable);
413               Set_Etype (E, RTE (RE_Exception_Occurrence));
414               Set_Scope (E, Current_Scope);
415            end if;
416
417            Rewrite (N,
418              Make_Function_Call (Loc,
419                Name => New_Occurrence_Of (RTE (Ent), Loc),
420                Parameter_Associations => New_List (
421                  New_Occurrence_Of (Choice_Parameter (P), Loc))));
422            exit;
423
424         --  Keep climbing!
425
426         else
427            P := Parent (P);
428         end if;
429      end loop;
430
431      Analyze_And_Resolve (N, Standard_String);
432   end Expand_Exception_Call;
433
434   ------------------------
435   -- Expand_Import_Call --
436   ------------------------
437
438   --  The function call must have a static string as its argument. We create
439   --  a dummy variable which uses this string as the external name in an
440   --  Import pragma. The result is then obtained as the address of this
441   --  dummy variable, converted to the appropriate target type.
442
443   procedure Expand_Import_Call (N : Node_Id) is
444      Loc : constant Source_Ptr := Sloc (N);
445      Ent : constant Entity_Id  := Entity (Name (N));
446      Str : constant Node_Id    := First_Actual (N);
447      Dum : constant Entity_Id  := Make_Temporary (Loc, 'D');
448
449   begin
450      Insert_Actions (N, New_List (
451        Make_Object_Declaration (Loc,
452          Defining_Identifier => Dum,
453          Object_Definition   =>
454            New_Occurrence_Of (Standard_Character, Loc)),
455
456        Make_Pragma (Loc,
457          Chars                        => Name_Import,
458          Pragma_Argument_Associations => New_List (
459            Make_Pragma_Argument_Association (Loc,
460              Expression => Make_Identifier (Loc, Name_Ada)),
461
462            Make_Pragma_Argument_Association (Loc,
463              Expression => Make_Identifier (Loc, Chars (Dum))),
464
465            Make_Pragma_Argument_Association (Loc,
466              Chars => Name_Link_Name,
467              Expression => Relocate_Node (Str))))));
468
469      Rewrite (N,
470        Unchecked_Convert_To (Etype (Ent),
471          Make_Attribute_Reference (Loc,
472            Prefix         => Make_Identifier (Loc, Chars (Dum)),
473            Attribute_Name => Name_Address)));
474
475      Analyze_And_Resolve (N, Etype (Ent));
476   end Expand_Import_Call;
477
478   ---------------------------
479   -- Expand_Intrinsic_Call --
480   ---------------------------
481
482   procedure Expand_Intrinsic_Call (N : Node_Id; E : Entity_Id) is
483      Nam : Name_Id;
484
485   begin
486      --  If an external name is specified for the intrinsic, it is handled
487      --  by the back-end: leave the call node unchanged for now.
488
489      if Present (Interface_Name (E)) then
490         return;
491      end if;
492
493      --  If the intrinsic subprogram is generic, gets its original name
494
495      if Present (Parent (E))
496        and then Present (Generic_Parent (Parent (E)))
497      then
498         Nam := Chars (Generic_Parent (Parent (E)));
499      else
500         Nam := Chars (E);
501      end if;
502
503      if Nam = Name_Asm then
504         Expand_Asm_Call (N);
505
506      elsif Nam = Name_Divide then
507         Expand_Decimal_Divide_Call (N);
508
509      elsif Nam = Name_Exception_Information then
510         Expand_Exception_Call (N, RE_Exception_Information);
511
512      elsif Nam = Name_Exception_Message then
513         Expand_Exception_Call (N, RE_Exception_Message);
514
515      elsif Nam = Name_Exception_Name then
516         Expand_Exception_Call (N, RE_Exception_Name_Simple);
517
518      elsif Nam = Name_Generic_Dispatching_Constructor then
519         Expand_Dispatching_Constructor_Call (N);
520
521      elsif Nam = Name_Import_Address
522              or else
523            Nam = Name_Import_Largest_Value
524              or else
525            Nam = Name_Import_Value
526      then
527         Expand_Import_Call (N);
528
529      elsif Nam = Name_Is_Negative then
530         Expand_Is_Negative (N);
531
532      elsif Nam = Name_Rotate_Left then
533         Expand_Shift (N, E, N_Op_Rotate_Left);
534
535      elsif Nam = Name_Rotate_Right then
536         Expand_Shift (N, E, N_Op_Rotate_Right);
537
538      elsif Nam = Name_Shift_Left then
539         Expand_Shift (N, E, N_Op_Shift_Left);
540
541      elsif Nam = Name_Shift_Right then
542         Expand_Shift (N, E, N_Op_Shift_Right);
543
544      elsif Nam = Name_Shift_Right_Arithmetic then
545         Expand_Shift (N, E, N_Op_Shift_Right_Arithmetic);
546
547      elsif Nam = Name_Unchecked_Conversion then
548         Expand_Unc_Conversion (N, E);
549
550      elsif Nam = Name_Unchecked_Deallocation then
551         Expand_Unc_Deallocation (N);
552
553      elsif Nam = Name_To_Address then
554         Expand_To_Address (N);
555
556      elsif Nam = Name_To_Pointer then
557         Expand_To_Pointer (N);
558
559      elsif Nam = Name_File
560        or else Nam = Name_Line
561        or else Nam = Name_Source_Location
562        or else Nam = Name_Enclosing_Entity
563      then
564         Expand_Source_Info (N, Nam);
565
566         --  If we have a renaming, expand the call to the original operation,
567         --  which must itself be intrinsic, since renaming requires matching
568         --  conventions and this has already been checked.
569
570      elsif Present (Alias (E)) then
571         Expand_Intrinsic_Call (N, Alias (E));
572
573      elsif Nkind (N) in N_Binary_Op then
574         Expand_Binary_Operator_Call (N);
575
576         --  The only other case is where an external name was specified, since
577         --  this is the only way that an otherwise unrecognized name could
578         --  escape the checking in Sem_Prag. Nothing needs to be done in such
579         --  a case, since we pass such a call to the back end unchanged.
580
581      else
582         null;
583      end if;
584   end Expand_Intrinsic_Call;
585
586   ------------------------
587   -- Expand_Is_Negative --
588   ------------------------
589
590   procedure Expand_Is_Negative (N : Node_Id) is
591      Loc   : constant Source_Ptr := Sloc (N);
592      Opnd  : constant Node_Id    := Relocate_Node (First_Actual (N));
593
594   begin
595
596      --  We replace the function call by the following expression
597
598      --    if Opnd < 0.0 then
599      --       True
600      --    else
601      --       if Opnd > 0.0 then
602      --          False;
603      --       else
604      --          Float_Unsigned!(Float (Opnd)) /= 0
605      --       end if;
606      --    end if;
607
608      Rewrite (N,
609        Make_If_Expression (Loc,
610          Expressions => New_List (
611            Make_Op_Lt (Loc,
612              Left_Opnd  => Duplicate_Subexpr (Opnd),
613              Right_Opnd => Make_Real_Literal (Loc, Ureal_0)),
614
615            New_Occurrence_Of (Standard_True, Loc),
616
617            Make_If_Expression (Loc,
618             Expressions => New_List (
619               Make_Op_Gt (Loc,
620                 Left_Opnd  => Duplicate_Subexpr_No_Checks (Opnd),
621                 Right_Opnd => Make_Real_Literal (Loc, Ureal_0)),
622
623               New_Occurrence_Of (Standard_False, Loc),
624
625                Make_Op_Ne (Loc,
626                  Left_Opnd =>
627                    Unchecked_Convert_To
628                      (RTE (RE_Float_Unsigned),
629                       Convert_To
630                         (Standard_Float,
631                          Duplicate_Subexpr_No_Checks (Opnd))),
632                  Right_Opnd =>
633                    Make_Integer_Literal (Loc, 0)))))));
634
635      Analyze_And_Resolve (N, Standard_Boolean);
636   end Expand_Is_Negative;
637
638   ------------------
639   -- Expand_Shift --
640   ------------------
641
642   --  This procedure is used to convert a call to a shift function to the
643   --  corresponding operator node. This conversion is not done by the usual
644   --  circuit for converting calls to operator functions (e.g. "+"(1,2)) to
645   --  operator nodes, because shifts are not predefined operators.
646
647   --  As a result, whenever a shift is used in the source program, it will
648   --  remain as a call until converted by this routine to the operator node
649   --  form which Gigi is expecting to see.
650
651   --  Note: it is possible for the expander to generate shift operator nodes
652   --  directly, which will be analyzed in the normal manner by calling Analyze
653   --  and Resolve. Such shift operator nodes will not be seen by Expand_Shift.
654
655   procedure Expand_Shift (N : Node_Id; E : Entity_Id; K : Node_Kind) is
656      Entyp : constant Entity_Id  := Etype (E);
657      Left  : constant Node_Id    := First_Actual (N);
658      Loc   : constant Source_Ptr := Sloc (N);
659      Right : constant Node_Id    := Next_Actual (Left);
660      Ltyp  : constant Node_Id    := Etype (Left);
661      Rtyp  : constant Node_Id    := Etype (Right);
662      Typ   : constant Entity_Id  := Etype (N);
663      Snode : Node_Id;
664
665   begin
666      Snode := New_Node (K, Loc);
667      Set_Right_Opnd (Snode, Relocate_Node (Right));
668      Set_Chars      (Snode, Chars (E));
669      Set_Etype      (Snode, Base_Type (Entyp));
670      Set_Entity     (Snode, E);
671
672      if Compile_Time_Known_Value (Type_High_Bound (Rtyp))
673        and then Expr_Value (Type_High_Bound (Rtyp)) < Esize (Ltyp)
674      then
675         Set_Shift_Count_OK (Snode, True);
676      end if;
677
678      if Typ = Entyp then
679
680         --  Note that we don't call Analyze and Resolve on this node, because
681         --  it already got analyzed and resolved when it was a function call.
682
683         Set_Left_Opnd (Snode, Relocate_Node (Left));
684         Rewrite (N, Snode);
685         Set_Analyzed (N);
686
687      else
688
689         --  If the context type is not the type of the operator, it is an
690         --  inherited operator for a derived type. Wrap the node in a
691         --  conversion so that it is type-consistent for possible further
692         --  expansion (e.g. within a lock-free protected type).
693
694         Set_Left_Opnd (Snode,
695           Unchecked_Convert_To (Base_Type (Entyp), Relocate_Node (Left)));
696         Rewrite (N, Unchecked_Convert_To (Typ, Snode));
697
698         --  Analyze and resolve result formed by conversion to target type
699
700         Analyze_And_Resolve (N, Typ);
701      end if;
702   end Expand_Shift;
703
704   ------------------------
705   -- Expand_Source_Info --
706   ------------------------
707
708   procedure Expand_Source_Info (N : Node_Id; Nam : Name_Id) is
709      Loc : constant Source_Ptr := Sloc (N);
710      Ent : Entity_Id;
711
712      procedure Write_Entity_Name (E : Entity_Id);
713      --  Recursive procedure to construct string for qualified name of
714      --  enclosing program unit. The qualification stops at an enclosing
715      --  scope has no source name (block or loop). If entity is a subprogram
716      --  instance, skip enclosing wrapper package.
717
718      -----------------------
719      -- Write_Entity_Name --
720      -----------------------
721
722      procedure Write_Entity_Name (E : Entity_Id) is
723         SDef : Source_Ptr;
724         TDef : constant Source_Buffer_Ptr :=
725                  Source_Text (Get_Source_File_Index (Sloc (E)));
726
727      begin
728         --  Nothing to do if at outer level
729
730         if Scope (E) = Standard_Standard then
731            null;
732
733         --  If scope comes from source, write its name
734
735         elsif Comes_From_Source (Scope (E)) then
736            Write_Entity_Name (Scope (E));
737            Add_Char_To_Name_Buffer ('.');
738
739         --  If in wrapper package skip past it
740
741         elsif Is_Wrapper_Package (Scope (E)) then
742            Write_Entity_Name (Scope (Scope (E)));
743            Add_Char_To_Name_Buffer ('.');
744
745         --  Otherwise nothing to output (happens in unnamed block statements)
746
747         else
748            null;
749         end if;
750
751         --  Loop to output the name
752
753         --  is this right wrt wide char encodings ??? (no!)
754
755         SDef := Sloc (E);
756         while TDef (SDef) in '0' .. '9'
757           or else TDef (SDef) >= 'A'
758           or else TDef (SDef) = ASCII.ESC
759         loop
760            Add_Char_To_Name_Buffer (TDef (SDef));
761            SDef := SDef + 1;
762         end loop;
763      end Write_Entity_Name;
764
765   --  Start of processing for Expand_Source_Info
766
767   begin
768      --  Integer cases
769
770      if Nam = Name_Line then
771         Rewrite (N,
772           Make_Integer_Literal (Loc,
773             Intval => UI_From_Int (Int (Get_Logical_Line_Number (Loc)))));
774         Analyze_And_Resolve (N, Standard_Positive);
775
776      --  String cases
777
778      else
779         Name_Len := 0;
780
781         case Nam is
782            when Name_File =>
783               Get_Decoded_Name_String
784                 (Reference_Name (Get_Source_File_Index (Loc)));
785
786            when Name_Source_Location =>
787               Build_Location_String (Loc);
788
789            when Name_Enclosing_Entity =>
790
791               --  Skip enclosing blocks to reach enclosing unit
792
793               Ent := Current_Scope;
794               while Present (Ent) loop
795                  exit when Ekind (Ent) /= E_Block
796                    and then Ekind (Ent) /= E_Loop;
797                  Ent := Scope (Ent);
798               end loop;
799
800               --  Ent now points to the relevant defining entity
801
802               Write_Entity_Name (Ent);
803
804            when others =>
805               raise Program_Error;
806         end case;
807
808         Rewrite (N,
809           Make_String_Literal (Loc,
810             Strval => String_From_Name_Buffer));
811         Analyze_And_Resolve (N, Standard_String);
812      end if;
813
814      Set_Is_Static_Expression (N);
815   end Expand_Source_Info;
816
817   ---------------------------
818   -- Expand_Unc_Conversion --
819   ---------------------------
820
821   procedure Expand_Unc_Conversion (N : Node_Id; E : Entity_Id) is
822      Func : constant Entity_Id  := Entity (Name (N));
823      Conv : Node_Id;
824      Ftyp : Entity_Id;
825      Ttyp : Entity_Id;
826
827   begin
828      --  Rewrite as unchecked conversion node. Note that we must convert
829      --  the operand to the formal type of the input parameter of the
830      --  function, so that the resulting N_Unchecked_Type_Conversion
831      --  call indicates the correct types for Gigi.
832
833      --  Right now, we only do this if a scalar type is involved. It is
834      --  not clear if it is needed in other cases. If we do attempt to
835      --  do the conversion unconditionally, it crashes 3411-018. To be
836      --  investigated further ???
837
838      Conv := Relocate_Node (First_Actual (N));
839      Ftyp := Etype (First_Formal (Func));
840
841      if Is_Scalar_Type (Ftyp) then
842         Conv := Convert_To (Ftyp, Conv);
843         Set_Parent (Conv, N);
844         Analyze_And_Resolve (Conv);
845      end if;
846
847      --  The instantiation of Unchecked_Conversion creates a wrapper package,
848      --  and the target type is declared as a subtype of the actual. Recover
849      --  the actual, which is the subtype indic. in the subtype declaration
850      --  for the target type. This is semantically correct, and avoids
851      --  anomalies with access subtypes. For entities, leave type as is.
852
853      --  We do the analysis here, because we do not want the compiler
854      --  to try to optimize or otherwise reorganize the unchecked
855      --  conversion node.
856
857      Ttyp := Etype (E);
858
859      if Is_Entity_Name (Conv) then
860         null;
861
862      elsif Nkind (Parent (Ttyp)) = N_Subtype_Declaration then
863         Ttyp := Entity (Subtype_Indication (Parent (Etype (E))));
864
865      elsif Is_Itype (Ttyp) then
866         Ttyp :=
867           Entity (Subtype_Indication (Associated_Node_For_Itype (Ttyp)));
868      else
869         raise Program_Error;
870      end if;
871
872      Rewrite (N, Unchecked_Convert_To (Ttyp, Conv));
873      Set_Etype (N, Ttyp);
874      Set_Analyzed (N);
875
876      if Nkind (N) = N_Unchecked_Type_Conversion then
877         Expand_N_Unchecked_Type_Conversion (N);
878      end if;
879   end Expand_Unc_Conversion;
880
881   -----------------------------
882   -- Expand_Unc_Deallocation --
883   -----------------------------
884
885   --  Generate the following Code :
886
887   --    if Arg /= null then
888   --     <Finalize_Call> (.., T'Class(Arg.all), ..);  -- for controlled types
889   --       Free (Arg);
890   --       Arg := Null;
891   --    end if;
892
893   --  For a task, we also generate a call to Free_Task to ensure that the
894   --  task itself is freed if it is terminated, ditto for a simple protected
895   --  object, with a call to Finalize_Protection. For composite types that
896   --  have tasks or simple protected objects as components, we traverse the
897   --  structures to find and terminate those components.
898
899   procedure Expand_Unc_Deallocation (N : Node_Id) is
900      Arg       : constant Node_Id    := First_Actual (N);
901      Loc       : constant Source_Ptr := Sloc (N);
902      Typ       : constant Entity_Id  := Etype (Arg);
903      Desig_T   : constant Entity_Id  := Designated_Type (Typ);
904      Rtyp      : constant Entity_Id  := Underlying_Type (Root_Type (Typ));
905      Pool      : constant Entity_Id  := Associated_Storage_Pool (Rtyp);
906      Stmts     : constant List_Id    := New_List;
907      Needs_Fin : constant Boolean    := Needs_Finalization (Desig_T);
908
909      Finalizer_Data  : Finalization_Exception_Data;
910
911      Blk        : Node_Id := Empty;
912      Deref      : Node_Id;
913      Final_Code : List_Id;
914      Free_Arg   : Node_Id;
915      Free_Node  : Node_Id;
916      Gen_Code   : Node_Id;
917
918      Arg_Known_Non_Null : constant Boolean := Known_Non_Null (N);
919      --  This captures whether we know the argument to be non-null so that
920      --  we can avoid the test. The reason that we need to capture this is
921      --  that we analyze some generated statements before properly attaching
922      --  them to the tree, and that can disturb current value settings.
923
924   begin
925      --  Nothing to do if we know the argument is null
926
927      if Known_Null (N) then
928         return;
929      end if;
930
931      --  Processing for pointer to controlled type
932
933      if Needs_Fin then
934         Deref :=
935           Make_Explicit_Dereference (Loc,
936             Prefix => Duplicate_Subexpr_No_Checks (Arg));
937
938         --  If the type is tagged, then we must force dispatching on the
939         --  finalization call because the designated type may not be the
940         --  actual type of the object.
941
942         if Is_Tagged_Type (Desig_T)
943           and then not Is_Class_Wide_Type (Desig_T)
944         then
945            Deref := Unchecked_Convert_To (Class_Wide_Type (Desig_T), Deref);
946
947         elsif not Is_Tagged_Type (Desig_T) then
948
949            --  Set type of result, to force a conversion when needed (see
950            --  exp_ch7, Convert_View), given that Deep_Finalize may be
951            --  inherited from the parent type, and we need the type of the
952            --  expression to see whether the conversion is in fact needed.
953
954            Set_Etype (Deref, Desig_T);
955         end if;
956
957         --  The finalization call is expanded wrapped in a block to catch any
958         --  possible exception. If an exception does occur, then Program_Error
959         --  must be raised following the freeing of the object and its removal
960         --  from the finalization collection's list. We set a flag to record
961         --  that an exception was raised, and save its occurrence for use in
962         --  the later raise.
963         --
964         --  Generate:
965         --    Abort  : constant Boolean :=
966         --               Exception_Occurrence (Get_Current_Excep.all.all) =
967         --                 Standard'Abort_Signal'Identity;
968         --      <or>
969         --    Abort  : constant Boolean := False;  --  no abort
970
971         --    E      : Exception_Occurrence;
972         --    Raised : Boolean := False;
973         --
974         --    begin
975         --       [Deep_]Finalize (Obj);
976         --    exception
977         --       when others =>
978         --          Raised := True;
979         --          Save_Occurrence (E, Get_Current_Excep.all.all);
980         --    end;
981
982         Build_Object_Declarations (Finalizer_Data, Stmts, Loc);
983
984         Final_Code := New_List (
985           Make_Block_Statement (Loc,
986             Handled_Statement_Sequence =>
987               Make_Handled_Sequence_Of_Statements (Loc,
988                 Statements         => New_List (
989                   Make_Final_Call (Obj_Ref => Deref, Typ => Desig_T)),
990                 Exception_Handlers => New_List (
991                   Build_Exception_Handler (Finalizer_Data)))));
992
993         --  For .NET/JVM, detach the object from the containing finalization
994         --  collection before finalizing it.
995
996         if VM_Target /= No_VM and then Is_Controlled (Desig_T) then
997            Prepend_To (Final_Code,
998              Make_Detach_Call (New_Copy_Tree (Arg)));
999         end if;
1000
1001         --  If aborts are allowed, then the finalization code must be
1002         --  protected by an abort defer/undefer pair.
1003
1004         if Abort_Allowed then
1005            Prepend_To (Final_Code,
1006              Build_Runtime_Call (Loc, RE_Abort_Defer));
1007
1008            Blk :=
1009              Make_Block_Statement (Loc, Handled_Statement_Sequence =>
1010                Make_Handled_Sequence_Of_Statements (Loc,
1011                  Statements  => Final_Code,
1012                  At_End_Proc =>
1013                    New_Occurrence_Of (RTE (RE_Abort_Undefer_Direct), Loc)));
1014
1015            Append (Blk, Stmts);
1016         else
1017            Append_List_To (Stmts, Final_Code);
1018         end if;
1019      end if;
1020
1021      --  For a task type, call Free_Task before freeing the ATCB
1022
1023      if Is_Task_Type (Desig_T) then
1024         declare
1025            Stat : Node_Id := Prev (N);
1026            Nam1 : Node_Id;
1027            Nam2 : Node_Id;
1028
1029         begin
1030            --  An Abort followed by a Free will not do what the user expects,
1031            --  because the abort is not immediate. This is worth a warning.
1032
1033            while Present (Stat)
1034              and then not Comes_From_Source (Original_Node (Stat))
1035            loop
1036               Prev (Stat);
1037            end loop;
1038
1039            if Present (Stat)
1040              and then Nkind (Original_Node (Stat)) = N_Abort_Statement
1041            then
1042               Stat := Original_Node (Stat);
1043               Nam1 := First (Names (Stat));
1044               Nam2 := Original_Node (First (Parameter_Associations (N)));
1045
1046               if Nkind (Nam1) = N_Explicit_Dereference
1047                 and then Is_Entity_Name (Prefix (Nam1))
1048                 and then Is_Entity_Name (Nam2)
1049                 and then Entity (Prefix (Nam1)) = Entity (Nam2)
1050               then
1051                  Error_Msg_N ("abort may take time to complete??", N);
1052                  Error_Msg_N ("\deallocation might have no effect??", N);
1053                  Error_Msg_N ("\safer to wait for termination??", N);
1054               end if;
1055            end if;
1056         end;
1057
1058         Append_To
1059           (Stmts, Cleanup_Task (N, Duplicate_Subexpr_No_Checks (Arg)));
1060
1061      --  For composite types that contain tasks, recurse over the structure
1062      --  to build the selectors for the task subcomponents.
1063
1064      elsif Has_Task (Desig_T) then
1065         if Is_Record_Type (Desig_T) then
1066            Append_List_To (Stmts, Cleanup_Record (N, Arg, Desig_T));
1067
1068         elsif Is_Array_Type (Desig_T) then
1069            Append_List_To (Stmts, Cleanup_Array (N, Arg, Desig_T));
1070         end if;
1071      end if;
1072
1073      --  Same for simple protected types. Eventually call Finalize_Protection
1074      --  before freeing the PO for each protected component.
1075
1076      if Is_Simple_Protected_Type (Desig_T) then
1077         Append_To (Stmts,
1078           Cleanup_Protected_Object (N, Duplicate_Subexpr_No_Checks (Arg)));
1079
1080      elsif Has_Simple_Protected_Object (Desig_T) then
1081         if Is_Record_Type (Desig_T) then
1082            Append_List_To (Stmts, Cleanup_Record (N, Arg, Desig_T));
1083         elsif Is_Array_Type (Desig_T) then
1084            Append_List_To (Stmts, Cleanup_Array (N, Arg, Desig_T));
1085         end if;
1086      end if;
1087
1088      --  Normal processing for non-controlled types
1089
1090      Free_Arg := Duplicate_Subexpr_No_Checks (Arg);
1091      Free_Node := Make_Free_Statement (Loc, Empty);
1092      Append_To (Stmts, Free_Node);
1093      Set_Storage_Pool (Free_Node, Pool);
1094
1095      --  Attach to tree before analysis of generated subtypes below
1096
1097      Set_Parent (Stmts, Parent (N));
1098
1099      --  Deal with storage pool
1100
1101      if Present (Pool) then
1102
1103         --  Freeing the secondary stack is meaningless
1104
1105         if Is_RTE (Pool, RE_SS_Pool) then
1106            null;
1107
1108         --  If the pool object is of a simple storage pool type, then attempt
1109         --  to locate the type's Deallocate procedure, if any, and set the
1110         --  free operation's procedure to call. If the type doesn't have a
1111         --  Deallocate (which is allowed), then the actual will simply be set
1112         --  to null.
1113
1114         elsif Present (Get_Rep_Pragma
1115                          (Etype (Pool), Name_Simple_Storage_Pool_Type))
1116         then
1117            declare
1118               Pool_Type  : constant Entity_Id := Base_Type (Etype (Pool));
1119               Dealloc_Op : Entity_Id;
1120            begin
1121               Dealloc_Op := Get_Name_Entity_Id (Name_Deallocate);
1122               while Present (Dealloc_Op) loop
1123                  if Scope (Dealloc_Op) = Scope (Pool_Type)
1124                    and then Present (First_Formal (Dealloc_Op))
1125                    and then Etype (First_Formal (Dealloc_Op)) = Pool_Type
1126                  then
1127                     Set_Procedure_To_Call (Free_Node, Dealloc_Op);
1128                     exit;
1129                  else
1130                     Dealloc_Op := Homonym (Dealloc_Op);
1131                  end if;
1132               end loop;
1133            end;
1134
1135         --  Case of a class-wide pool type: make a dispatching call to
1136         --  Deallocate through the class-wide Deallocate_Any.
1137
1138         elsif Is_Class_Wide_Type (Etype (Pool)) then
1139            Set_Procedure_To_Call (Free_Node, RTE (RE_Deallocate_Any));
1140
1141         --  Case of a specific pool type: make a statically bound call
1142
1143         else
1144            Set_Procedure_To_Call (Free_Node,
1145              Find_Prim_Op (Etype (Pool), Name_Deallocate));
1146         end if;
1147      end if;
1148
1149      if Present (Procedure_To_Call (Free_Node)) then
1150
1151         --  For all cases of a Deallocate call, the back-end needs to be able
1152         --  to compute the size of the object being freed. This may require
1153         --  some adjustments for objects of dynamic size.
1154         --
1155         --  If the type is class wide, we generate an implicit type with the
1156         --  right dynamic size, so that the deallocate call gets the right
1157         --  size parameter computed by GIGI. Same for an access to
1158         --  unconstrained packed array.
1159
1160         if Is_Class_Wide_Type (Desig_T)
1161           or else
1162            (Is_Array_Type (Desig_T)
1163              and then not Is_Constrained (Desig_T)
1164              and then Is_Packed (Desig_T))
1165         then
1166            declare
1167               Deref    : constant Node_Id :=
1168                            Make_Explicit_Dereference (Loc,
1169                              Duplicate_Subexpr_No_Checks (Arg));
1170               D_Subtyp : Node_Id;
1171               D_Type   : Entity_Id;
1172
1173            begin
1174               --  Perform minor decoration as it is needed by the side effect
1175               --  removal mechanism.
1176
1177               Set_Etype  (Deref, Desig_T);
1178               Set_Parent (Deref, Free_Node);
1179               D_Subtyp := Make_Subtype_From_Expr (Deref, Desig_T);
1180
1181               if Nkind (D_Subtyp) in N_Has_Entity then
1182                  D_Type := Entity (D_Subtyp);
1183
1184               else
1185                  D_Type := Make_Temporary (Loc, 'A');
1186                  Insert_Action (Deref,
1187                    Make_Subtype_Declaration (Loc,
1188                      Defining_Identifier => D_Type,
1189                      Subtype_Indication  => D_Subtyp));
1190               end if;
1191
1192               --  Force freezing at the point of the dereference. For the
1193               --  class wide case, this avoids having the subtype frozen
1194               --  before the equivalent type.
1195
1196               Freeze_Itype (D_Type, Deref);
1197
1198               Set_Actual_Designated_Subtype (Free_Node, D_Type);
1199            end;
1200
1201         end if;
1202      end if;
1203
1204      --  Ada 2005 (AI-251): In case of abstract interface type we must
1205      --  displace the pointer to reference the base of the object to
1206      --  deallocate its memory, unless we're targetting a VM, in which case
1207      --  no special processing is required.
1208
1209      --  Generate:
1210      --    free (Base_Address (Obj_Ptr))
1211
1212      if Is_Interface (Directly_Designated_Type (Typ))
1213        and then Tagged_Type_Expansion
1214      then
1215         Set_Expression (Free_Node,
1216           Unchecked_Convert_To (Typ,
1217             Make_Function_Call (Loc,
1218               Name => New_Reference_To (RTE (RE_Base_Address), Loc),
1219               Parameter_Associations => New_List (
1220                 Unchecked_Convert_To (RTE (RE_Address), Free_Arg)))));
1221
1222      --  Generate:
1223      --    free (Obj_Ptr)
1224
1225      else
1226         Set_Expression (Free_Node, Free_Arg);
1227      end if;
1228
1229      --  Only remaining step is to set result to null, or generate a raise of
1230      --  Constraint_Error if the target object is "not null".
1231
1232      if Can_Never_Be_Null (Etype (Arg)) then
1233         Append_To (Stmts,
1234           Make_Raise_Constraint_Error (Loc,
1235             Reason => CE_Access_Check_Failed));
1236
1237      else
1238         declare
1239            Lhs : constant Node_Id := Duplicate_Subexpr_No_Checks (Arg);
1240         begin
1241            Set_Assignment_OK (Lhs);
1242            Append_To (Stmts,
1243              Make_Assignment_Statement (Loc,
1244                Name       => Lhs,
1245                Expression => Make_Null (Loc)));
1246         end;
1247      end if;
1248
1249      --  Generate a test of whether any earlier finalization raised an
1250      --  exception, and in that case raise Program_Error with the previous
1251      --  exception occurrence.
1252
1253      --  Generate:
1254      --    if Raised and then not Abort then
1255      --       raise Program_Error;                  --  for .NET and
1256      --                                             --  restricted RTS
1257      --         <or>
1258      --       Raise_From_Controlled_Operation (E);  --  all other cases
1259      --    end if;
1260
1261      if Needs_Fin then
1262         Append_To (Stmts, Build_Raise_Statement (Finalizer_Data));
1263      end if;
1264
1265      --  If we know the argument is non-null, then make a block statement
1266      --  that contains the required statements, no need for a test.
1267
1268      if Arg_Known_Non_Null then
1269         Gen_Code :=
1270           Make_Block_Statement (Loc,
1271             Handled_Statement_Sequence =>
1272               Make_Handled_Sequence_Of_Statements (Loc,
1273             Statements => Stmts));
1274
1275      --  If the argument may be null, wrap the statements inside an IF that
1276      --  does an explicit test to exclude the null case.
1277
1278      else
1279         Gen_Code :=
1280           Make_Implicit_If_Statement (N,
1281             Condition =>
1282               Make_Op_Ne (Loc,
1283                 Left_Opnd  => Duplicate_Subexpr (Arg),
1284                 Right_Opnd => Make_Null (Loc)),
1285             Then_Statements => Stmts);
1286      end if;
1287
1288      --  Rewrite the call
1289
1290      Rewrite (N, Gen_Code);
1291      Analyze (N);
1292
1293      --  If we generated a block with an At_End_Proc, expand the exception
1294      --  handler. We need to wait until after everything else is analyzed.
1295
1296      if Present (Blk) then
1297         Expand_At_End_Handler
1298           (Handled_Statement_Sequence (Blk), Entity (Identifier (Blk)));
1299      end if;
1300   end Expand_Unc_Deallocation;
1301
1302   -----------------------
1303   -- Expand_To_Address --
1304   -----------------------
1305
1306   procedure Expand_To_Address (N : Node_Id) is
1307      Loc : constant Source_Ptr := Sloc (N);
1308      Arg : constant Node_Id := First_Actual (N);
1309      Obj : Node_Id;
1310
1311   begin
1312      Remove_Side_Effects (Arg);
1313
1314      Obj := Make_Explicit_Dereference (Loc, Relocate_Node (Arg));
1315
1316      Rewrite (N,
1317        Make_If_Expression (Loc,
1318          Expressions => New_List (
1319            Make_Op_Eq (Loc,
1320              Left_Opnd => New_Copy_Tree (Arg),
1321              Right_Opnd => Make_Null (Loc)),
1322            New_Occurrence_Of (RTE (RE_Null_Address), Loc),
1323            Make_Attribute_Reference (Loc,
1324              Prefix         => Obj,
1325              Attribute_Name => Name_Address))));
1326
1327      Analyze_And_Resolve (N, RTE (RE_Address));
1328   end Expand_To_Address;
1329
1330   -----------------------
1331   -- Expand_To_Pointer --
1332   -----------------------
1333
1334   procedure Expand_To_Pointer (N : Node_Id) is
1335      Arg : constant Node_Id := First_Actual (N);
1336
1337   begin
1338      Rewrite (N, Unchecked_Convert_To (Etype (N), Arg));
1339      Analyze (N);
1340   end Expand_To_Pointer;
1341
1342end Exp_Intr;
1343