1 ------------------------------------------------------------------------------
3 -- GNAT COMPILER COMPONENTS --
9 -- Copyright (C) 1992-2005, Free Software Foundation, Inc. --
11 -- GNAT is free software; you can redistribute it and/or modify it under --
12 -- terms of the GNU General Public License as published by the Free Soft- --
13 -- ware Foundation; either version 2, or (at your option) any later ver- --
14 -- sion. GNAT is distributed in the hope that it will be useful, but WITH- --
15 -- OUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY --
16 -- or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License --
17 -- for more details. You should have received a copy of the GNU General --
18 -- Public License distributed with GNAT; see file COPYING. If not, write --
19 -- to the Free Software Foundation, 59 Temple Place - Suite 330, Boston, --
20 -- MA 02111-1307, USA. --
22 -- GNAT was originally developed by the GNAT team at New York University. --
23 -- Extensive contributions were provided by Ada Core Technologies Inc. --
25 ------------------------------------------------------------------------------
27 with Atree; use Atree;
28 with Einfo; use Einfo;
29 with Exp_Tss; use Exp_Tss;
30 with Namet; use Namet;
31 with Nlists; use Nlists;
32 with Nmake; use Nmake;
33 with Rtsfind; use Rtsfind;
34 with Sem_Util; use Sem_Util;
35 with Sinfo; use Sinfo;
36 with Snames; use Snames;
37 with Stand; use Stand;
38 with Tbuild; use Tbuild;
39 with Ttypes; use Ttypes;
40 with Uintp; use Uintp;
42 package body Exp_Strm is
44 -----------------------
45 -- Local Subprograms --
46 -----------------------
48 procedure Build_Array_Read_Write_Procedure
54 -- Common routine shared to build either an array Read procedure or an
55 -- array Write procedure, Nam is Name_Read or Name_Write to select which.
56 -- Pnam is the defining identifier for the constructed procedure. The
57 -- other parameters are as for Build_Array_Read_Procedure except that
58 -- the first parameter Nod supplies the Sloc to be used to generate code.
60 procedure Build_Record_Read_Write_Procedure
66 -- Common routine shared to build a record Read Write procedure, Nam
67 -- is Name_Read or Name_Write to select which. Pnam is the defining
68 -- identifier for the constructed procedure. The other parameters are
69 -- as for Build_Record_Read_Procedure.
71 procedure Build_Stream_Function
78 -- Called to build an array or record stream function. The first three
79 -- arguments are the same as Build_Record_Or_Elementary_Input_Function.
80 -- Decls and Stms are the declarations and statements for the body and
81 -- The parameter Fnam is the name of the constructed function.
83 function Has_Stream_Standard_Rep (U_Type : Entity_Id) return Boolean;
84 -- This function is used to test U_Type, which is a type
85 -- Returns True if U_Type has a standard representation for stream
86 -- purposes, i.e. there is no non-standard enumeration representation
87 -- clause, and the size of the first subtype is the same as the size
90 function Make_Stream_Subprogram_Name
93 Nam : TSS_Name_Type) return Entity_Id;
94 -- Return the entity that identifies the stream subprogram for type Typ
95 -- that is identified by the given Nam. This procedure deals with the
96 -- difference between tagged types (where a single subprogram associated
97 -- with the type is generated) and all other cases (where a subprogram
98 -- is generated at the point of the stream attribute reference). The
99 -- Loc parameter is used as the Sloc of the created entity.
101 function Stream_Base_Type (E : Entity_Id) return Entity_Id;
102 -- Stream attributes work on the basis of the base type except for the
103 -- array case. For the array case, we do not go to the base type, but
104 -- to the first subtype if it is constrained. This avoids problems with
105 -- incorrect conversions in the packed array case. Stream_Base_Type is
106 -- exactly this function (returns the base type, unless we have an array
107 -- type whose first subtype is constrained, in which case it returns the
110 --------------------------------
111 -- Build_Array_Input_Function --
112 --------------------------------
114 -- The function we build looks like
116 -- function typSI[_nnn] (S : access RST) return Typ is
117 -- L1 : constant Index_Type_1 := Index_Type_1'Input (S);
118 -- H1 : constant Index_Type_1 := Index_Type_1'Input (S);
119 -- L2 : constant Index_Type_2 := Index_Type_2'Input (S);
120 -- H2 : constant Index_Type_2 := Index_Type_2'Input (S);
122 -- Ln : constant Index_Type_n := Index_Type_n'Input (S);
123 -- Hn : constant Index_Type_n := Index_Type_n'Input (S);
125 -- V : Typ'Base (L1 .. H1, L2 .. H2, ... Ln .. Hn)
132 -- Note: the suffix [_nnn] is present for non-tagged types, where we
133 -- generate a local subprogram at the point of the occurrence of the
134 -- attribute reference, so the name must be unique.
136 procedure Build_Array_Input_Function
140 Fnam : out Entity_Id)
142 Dim : constant Pos := Number_Dimensions (Typ);
153 Indx := First_Index (Typ);
155 for J in 1 .. Dim loop
156 Lnam := New_External_Name ('L', J);
157 Hnam := New_External_Name ('H', J);
160 Make_Object_Declaration (Loc,
161 Defining_Identifier => Make_Defining_Identifier (Loc, Lnam),
162 Constant_Present => True,
163 Object_Definition => New_Occurrence_Of (Etype (Indx), Loc),
165 Make_Attribute_Reference (Loc,
167 New_Occurrence_Of (Stream_Base_Type (Etype (Indx)), Loc),
168 Attribute_Name => Name_Input,
169 Expressions => New_List (Make_Identifier (Loc, Name_S)))));
172 Make_Object_Declaration (Loc,
173 Defining_Identifier => Make_Defining_Identifier (Loc, Hnam),
174 Constant_Present => True,
176 New_Occurrence_Of (Stream_Base_Type (Etype (Indx)), Loc),
178 Make_Attribute_Reference (Loc,
180 New_Occurrence_Of (Stream_Base_Type (Etype (Indx)), Loc),
181 Attribute_Name => Name_Input,
182 Expressions => New_List (Make_Identifier (Loc, Name_S)))));
186 Low_Bound => Make_Identifier (Loc, Lnam),
187 High_Bound => Make_Identifier (Loc, Hnam)));
192 -- If the first subtype is constrained, use it directly. Otherwise
193 -- build a subtype indication with the proper bounds.
195 if Is_Constrained (Stream_Base_Type (Typ)) then
197 Make_Object_Declaration (Loc,
198 Defining_Identifier => Make_Defining_Identifier (Loc, Name_V),
200 New_Occurrence_Of (Stream_Base_Type (Typ), Loc)));
203 Make_Object_Declaration (Loc,
204 Defining_Identifier => Make_Defining_Identifier (Loc, Name_V),
206 Make_Subtype_Indication (Loc,
208 New_Occurrence_Of (Stream_Base_Type (Typ), Loc),
210 Make_Index_Or_Discriminant_Constraint (Loc,
211 Constraints => Ranges))));
215 Make_Attribute_Reference (Loc,
216 Prefix => New_Occurrence_Of (Typ, Loc),
217 Attribute_Name => Name_Read,
218 Expressions => New_List (
219 Make_Identifier (Loc, Name_S),
220 Make_Identifier (Loc, Name_V))),
222 Make_Return_Statement (Loc,
223 Expression => Make_Identifier (Loc, Name_V)));
226 Make_Defining_Identifier (Loc,
227 Chars => Make_TSS_Name_Local (Typ, TSS_Stream_Input));
229 Build_Stream_Function (Loc, Typ, Decl, Fnam, Decls, Stms);
230 end Build_Array_Input_Function;
232 ----------------------------------
233 -- Build_Array_Output_Procedure --
234 ----------------------------------
236 procedure Build_Array_Output_Procedure
240 Pnam : out Entity_Id)
246 -- Build series of statements to output bounds
248 Indx := First_Index (Typ);
251 for J in 1 .. Number_Dimensions (Typ) loop
253 Make_Attribute_Reference (Loc,
255 New_Occurrence_Of (Stream_Base_Type (Etype (Indx)), Loc),
256 Attribute_Name => Name_Write,
257 Expressions => New_List (
258 Make_Identifier (Loc, Name_S),
259 Make_Attribute_Reference (Loc,
260 Prefix => Make_Identifier (Loc, Name_V),
261 Attribute_Name => Name_First,
262 Expressions => New_List (
263 Make_Integer_Literal (Loc, J))))));
266 Make_Attribute_Reference (Loc,
268 New_Occurrence_Of (Stream_Base_Type (Etype (Indx)), Loc),
269 Attribute_Name => Name_Write,
270 Expressions => New_List (
271 Make_Identifier (Loc, Name_S),
272 Make_Attribute_Reference (Loc,
273 Prefix => Make_Identifier (Loc, Name_V),
274 Attribute_Name => Name_Last,
275 Expressions => New_List (
276 Make_Integer_Literal (Loc, J))))));
281 -- Append Write attribute to write array elements
284 Make_Attribute_Reference (Loc,
285 Prefix => New_Occurrence_Of (Typ, Loc),
286 Attribute_Name => Name_Write,
287 Expressions => New_List (
288 Make_Identifier (Loc, Name_S),
289 Make_Identifier (Loc, Name_V))));
292 Make_Defining_Identifier (Loc,
293 Chars => Make_TSS_Name_Local (Typ, TSS_Stream_Output));
295 Build_Stream_Procedure (Loc, Typ, Decl, Pnam, Stms, False);
296 end Build_Array_Output_Procedure;
298 --------------------------------
299 -- Build_Array_Read_Procedure --
300 --------------------------------
302 procedure Build_Array_Read_Procedure
306 Pnam : out Entity_Id)
308 Loc : constant Source_Ptr := Sloc (Nod);
312 Make_Defining_Identifier (Loc,
313 Chars => Make_TSS_Name_Local (Typ, TSS_Stream_Read));
314 Build_Array_Read_Write_Procedure (Nod, Typ, Decl, Pnam, Name_Read);
315 end Build_Array_Read_Procedure;
317 --------------------------------------
318 -- Build_Array_Read_Write_Procedure --
319 --------------------------------------
321 -- The form of the array read/write procedure is as follows:
323 -- procedure pnam (S : access RST, V : [out] Typ) is
325 -- for L1 in V'Range (1) loop
326 -- for L2 in V'Range (2) loop
328 -- for Ln in V'Range (n) loop
329 -- Component_Type'Read/Write (S, V (L1, L2, .. Ln));
336 -- The out keyword for V is supplied in the Read case
338 procedure Build_Array_Read_Write_Procedure
345 Loc : constant Source_Ptr := Sloc (Nod);
346 Ndim : constant Pos := Number_Dimensions (Typ);
347 Ctyp : constant Entity_Id := Component_Type (Typ);
354 -- First build the inner attribute call
358 for J in 1 .. Ndim loop
359 Append_To (Exl, Make_Identifier (Loc, New_External_Name ('L', J)));
363 Make_Attribute_Reference (Loc,
364 Prefix => New_Occurrence_Of (Stream_Base_Type (Ctyp), Loc),
365 Attribute_Name => Nam,
366 Expressions => New_List (
367 Make_Identifier (Loc, Name_S),
368 Make_Indexed_Component (Loc,
369 Prefix => Make_Identifier (Loc, Name_V),
370 Expressions => Exl)));
372 -- The corresponding stream attribute for the component type of the
373 -- array may be user-defined, and be frozen after the type for which
374 -- we are generating the stream subprogram. In that case, freeze the
375 -- stream attribute of the component type, whose declaration could not
376 -- generate any additional freezing actions in any case. See 5509-003.
378 if Nam = Name_Read then
379 RW := TSS (Base_Type (Ctyp), TSS_Stream_Read);
381 RW := TSS (Base_Type (Ctyp), TSS_Stream_Write);
385 and then not Is_Frozen (RW)
390 -- Now this is the big loop to wrap that statement up in a sequence
391 -- of loops. The first time around, Stm is the attribute call. The
392 -- second and subsequent times, Stm is an inner loop.
394 for J in 1 .. Ndim loop
396 Make_Implicit_Loop_Statement (Nod,
398 Make_Iteration_Scheme (Loc,
399 Loop_Parameter_Specification =>
400 Make_Loop_Parameter_Specification (Loc,
401 Defining_Identifier =>
402 Make_Defining_Identifier (Loc,
403 Chars => New_External_Name ('L', Ndim - J + 1)),
405 Discrete_Subtype_Definition =>
406 Make_Attribute_Reference (Loc,
407 Prefix => Make_Identifier (Loc, Name_V),
408 Attribute_Name => Name_Range,
410 Expressions => New_List (
411 Make_Integer_Literal (Loc, Ndim - J + 1))))),
413 Statements => New_List (Stm));
417 Build_Stream_Procedure
418 (Loc, Typ, Decl, Pnam, New_List (Stm), Nam = Name_Read);
419 end Build_Array_Read_Write_Procedure;
421 ---------------------------------
422 -- Build_Array_Write_Procedure --
423 ---------------------------------
425 procedure Build_Array_Write_Procedure
429 Pnam : out Entity_Id)
431 Loc : constant Source_Ptr := Sloc (Nod);
435 Make_Defining_Identifier (Loc,
436 Chars => Make_TSS_Name_Local (Typ, TSS_Stream_Write));
437 Build_Array_Read_Write_Procedure (Nod, Typ, Decl, Pnam, Name_Write);
438 end Build_Array_Write_Procedure;
440 ---------------------------------
441 -- Build_Elementary_Input_Call --
442 ---------------------------------
444 function Build_Elementary_Input_Call (N : Node_Id) return Node_Id is
445 Loc : constant Source_Ptr := Sloc (N);
446 P_Type : constant Entity_Id := Entity (Prefix (N));
447 U_Type : constant Entity_Id := Underlying_Type (P_Type);
448 Rt_Type : constant Entity_Id := Root_Type (U_Type);
449 FST : constant Entity_Id := First_Subtype (U_Type);
450 Strm : constant Node_Id := First (Expressions (N));
451 Targ : constant Node_Id := Next (Strm);
457 -- Compute the size of the stream element. This is either the size of
458 -- the first subtype or if given the size of the Stream_Size attribute.
460 if Is_Elementary_Type (FST) and then Has_Stream_Size_Clause (FST) then
461 P_Size := Static_Integer (Expression (Stream_Size_Clause (FST)));
463 P_Size := Esize (FST);
466 -- Check first for Boolean and Character. These are enumeration types,
467 -- but we treat them specially, since they may require special handling
468 -- in the transfer protocol. However, this special handling only applies
469 -- if they have standard representation, otherwise they are treated like
470 -- any other enumeration type.
472 if Rt_Type = Standard_Boolean
473 and then Has_Stream_Standard_Rep (U_Type)
477 elsif Rt_Type = Standard_Character
478 and then Has_Stream_Standard_Rep (U_Type)
482 elsif Rt_Type = Standard_Wide_Character
483 and then Has_Stream_Standard_Rep (U_Type)
487 elsif Rt_Type = Standard_Wide_Wide_Character
488 and then Has_Stream_Standard_Rep (U_Type)
492 -- Floating point types
494 elsif Is_Floating_Point_Type (U_Type) then
495 if P_Size <= Standard_Short_Float_Size then
498 elsif P_Size <= Standard_Float_Size then
501 elsif P_Size <= Standard_Long_Float_Size then
508 -- Signed integer types. Also includes signed fixed-point types and
509 -- enumeration types with a signed representation.
511 -- Note on signed integer types. We do not consider types as signed for
512 -- this purpose if they have no negative numbers, or if they have biased
513 -- representation. The reason is that the value in either case basically
514 -- represents an unsigned value.
516 -- For example, consider:
518 -- type W is range 0 .. 2**32 - 1;
519 -- for W'Size use 32;
521 -- This is a signed type, but the representation is unsigned, and may
522 -- be outside the range of a 32-bit signed integer, so this must be
523 -- treated as 32-bit unsigned.
525 -- Similarly, if we have
527 -- type W is range -1 .. +254;
530 -- then the representation is unsigned
532 elsif not Is_Unsigned_Type (FST)
534 (Is_Fixed_Point_Type (U_Type)
536 Is_Enumeration_Type (U_Type)
538 (Is_Signed_Integer_Type (U_Type)
539 and then not Has_Biased_Representation (FST)))
541 if P_Size <= Standard_Short_Short_Integer_Size then
544 elsif P_Size <= Standard_Short_Integer_Size then
547 elsif P_Size <= Standard_Integer_Size then
550 elsif P_Size <= Standard_Long_Integer_Size then
557 -- Unsigned integer types, also includes unsigned fixed-point types
558 -- and enumeration types with an unsigned representation (note that
559 -- we know they are unsigned because we already tested for signed).
561 -- Also includes signed integer types that are unsigned in the sense
562 -- that they do not include negative numbers. See above for details.
564 elsif Is_Modular_Integer_Type (U_Type)
565 or else Is_Fixed_Point_Type (U_Type)
566 or else Is_Enumeration_Type (U_Type)
567 or else Is_Signed_Integer_Type (U_Type)
569 if P_Size <= Standard_Short_Short_Integer_Size then
572 elsif P_Size <= Standard_Short_Integer_Size then
575 elsif P_Size <= Standard_Integer_Size then
578 elsif P_Size <= Standard_Long_Integer_Size then
585 else pragma Assert (Is_Access_Type (U_Type));
586 if P_Size > System_Address_Size then
593 -- Call the function, and do an unchecked conversion of the result
594 -- to the actual type of the prefix. If the target is a discriminant,
595 -- and we are in the body of the default implementation of a 'Read
596 -- attribute, set target type to force a constraint check (13.13.2(35)).
598 if Nkind (Targ) = N_Identifier
599 and then Is_Internal_Name (Chars (Targ))
600 and then Is_TSS (Scope (Entity (Targ)), TSS_Stream_Read)
603 Unchecked_Convert_To (Base_Type (P_Type),
604 Make_Function_Call (Loc,
605 Name => New_Occurrence_Of (RTE (Lib_RE), Loc),
606 Parameter_Associations => New_List (
607 Relocate_Node (Strm))));
609 Set_Do_Range_Check (Res);
614 Unchecked_Convert_To (P_Type,
615 Make_Function_Call (Loc,
616 Name => New_Occurrence_Of (RTE (Lib_RE), Loc),
617 Parameter_Associations => New_List (
618 Relocate_Node (Strm))));
620 end Build_Elementary_Input_Call;
622 ---------------------------------
623 -- Build_Elementary_Write_Call --
624 ---------------------------------
626 function Build_Elementary_Write_Call (N : Node_Id) return Node_Id is
627 Loc : constant Source_Ptr := Sloc (N);
628 P_Type : constant Entity_Id := Entity (Prefix (N));
629 U_Type : constant Entity_Id := Underlying_Type (P_Type);
630 Rt_Type : constant Entity_Id := Root_Type (U_Type);
631 FST : constant Entity_Id := First_Subtype (U_Type);
632 Strm : constant Node_Id := First (Expressions (N));
633 Item : constant Node_Id := Next (Strm);
639 -- Compute the size of the stream element. This is either the size of
640 -- the first subtype or if given the size of the Stream_Size attribute.
642 if Is_Elementary_Type (FST) and then Has_Stream_Size_Clause (FST) then
643 P_Size := Static_Integer (Expression (Stream_Size_Clause (FST)));
645 P_Size := Esize (FST);
648 -- Find the routine to be called
650 -- Check for First Boolean and Character. These are enumeration types,
651 -- but we treat them specially, since they may require special handling
652 -- in the transfer protocol. However, this special handling only applies
653 -- if they have standard representation, otherwise they are treated like
654 -- any other enumeration type.
656 if Rt_Type = Standard_Boolean
657 and then Has_Stream_Standard_Rep (U_Type)
661 elsif Rt_Type = Standard_Character
662 and then Has_Stream_Standard_Rep (U_Type)
666 elsif Rt_Type = Standard_Wide_Character
667 and then Has_Stream_Standard_Rep (U_Type)
671 elsif Rt_Type = Standard_Wide_Wide_Character
672 and then Has_Stream_Standard_Rep (U_Type)
676 -- Floating point types
678 elsif Is_Floating_Point_Type (U_Type) then
679 if P_Size <= Standard_Short_Float_Size then
681 elsif P_Size <= Standard_Float_Size then
683 elsif P_Size <= Standard_Long_Float_Size then
689 -- Signed integer types. Also includes signed fixed-point types and
690 -- signed enumeration types share this circuitry.
692 -- Note on signed integer types. We do not consider types as signed for
693 -- this purpose if they have no negative numbers, or if they have biased
694 -- representation. The reason is that the value in either case basically
695 -- represents an unsigned value.
697 -- For example, consider:
699 -- type W is range 0 .. 2**32 - 1;
700 -- for W'Size use 32;
702 -- This is a signed type, but the representation is unsigned, and may
703 -- be outside the range of a 32-bit signed integer, so this must be
704 -- treated as 32-bit unsigned.
706 -- Similarly, the representation is also unsigned if we have:
708 -- type W is range -1 .. +254;
711 elsif not Is_Unsigned_Type (FST)
713 (Is_Fixed_Point_Type (U_Type)
715 Is_Enumeration_Type (U_Type)
717 (Is_Signed_Integer_Type (U_Type)
718 and then not Has_Biased_Representation (FST)))
720 if P_Size <= Standard_Short_Short_Integer_Size then
722 elsif P_Size <= Standard_Short_Integer_Size then
724 elsif P_Size <= Standard_Integer_Size then
726 elsif P_Size <= Standard_Long_Integer_Size then
732 -- Unsigned integer types, also includes unsigned fixed-point types
733 -- and unsigned enumeration types (note we know they are unsigned
734 -- because we already tested for signed above).
736 -- Also includes signed integer types that are unsigned in the sense
737 -- that they do not include negative numbers. See above for details.
739 elsif Is_Modular_Integer_Type (U_Type)
740 or else Is_Fixed_Point_Type (U_Type)
741 or else Is_Enumeration_Type (U_Type)
742 or else Is_Signed_Integer_Type (U_Type)
744 if P_Size <= Standard_Short_Short_Integer_Size then
746 elsif P_Size <= Standard_Short_Integer_Size then
748 elsif P_Size <= Standard_Integer_Size then
750 elsif P_Size <= Standard_Long_Integer_Size then
756 else pragma Assert (Is_Access_Type (U_Type));
758 if P_Size > System_Address_Size then
765 -- Unchecked-convert parameter to the required type (i.e. the type of
766 -- the corresponding parameter, and call the appropriate routine.
768 Libent := RTE (Lib_RE);
771 Make_Procedure_Call_Statement (Loc,
772 Name => New_Occurrence_Of (Libent, Loc),
773 Parameter_Associations => New_List (
774 Relocate_Node (Strm),
775 Unchecked_Convert_To (Etype (Next_Formal (First_Formal (Libent))),
776 Relocate_Node (Item))));
777 end Build_Elementary_Write_Call;
779 -----------------------------------------
780 -- Build_Mutable_Record_Read_Procedure --
781 -----------------------------------------
783 procedure Build_Mutable_Record_Read_Procedure
787 Pnam : out Entity_Id)
789 Out_Formal : Node_Id;
790 -- Expression denoting the out formal parameter
792 Dcls : constant List_Id := New_List;
793 -- Declarations for the 'Read body
795 Stms : List_Id := New_List;
796 -- Statements for the 'Read body
799 -- Entity of the discriminant being processed
801 Tmp_For_Disc : Entity_Id;
802 -- Temporary object used to read the value of Disc
804 Tmps_For_Discs : constant List_Id := New_List;
805 -- List of object declarations for temporaries holding the read values
806 -- for the discriminants.
808 Cstr : constant List_Id := New_List;
809 -- List of constraints to be applied on temporary record
811 Discriminant_Checks : constant List_Id := New_List;
812 -- List of discriminant checks to be performed if the actual object
815 Tmp : constant Entity_Id := Make_Defining_Identifier (Loc, Name_V);
816 -- Temporary record must hide formal (assignments to components of the
817 -- record are always generated with V as the identifier for the record).
819 Constrained_Stms : List_Id := New_List;
820 -- Statements within the block where we have the constrained temporary
824 Disc := First_Discriminant (Typ);
826 -- A mutable type cannot be a tagged type, so we generate a new name
827 -- for the stream procedure.
830 Make_Defining_Identifier (Loc,
831 Chars => Make_TSS_Name_Local (Typ, TSS_Stream_Read));
834 Make_Selected_Component (Loc,
835 Prefix => New_Occurrence_Of (Pnam, Loc),
836 Selector_Name => Make_Identifier (Loc, Name_V));
838 -- Generate Reads for the discriminants of the type. The discriminants
839 -- need to be read before the rest of the components, so that
840 -- variants are initialized correctly. The discriminants must be read
841 -- into temporary variables so an incomplete Read (interrupted by an
842 -- exception, for example) does not alter the passed object.
844 while Present (Disc) loop
845 Tmp_For_Disc := Make_Defining_Identifier (Loc,
846 New_External_Name (Chars (Disc), "D"));
848 Append_To (Tmps_For_Discs,
849 Make_Object_Declaration (Loc,
850 Defining_Identifier => Tmp_For_Disc,
851 Object_Definition => New_Occurrence_Of (Etype (Disc), Loc)));
852 Set_No_Initialization (Last (Tmps_For_Discs));
855 Make_Attribute_Reference (Loc,
856 Prefix => New_Occurrence_Of (Etype (Disc), Loc),
857 Attribute_Name => Name_Read,
858 Expressions => New_List (
859 Make_Identifier (Loc, Name_S),
860 New_Occurrence_Of (Tmp_For_Disc, Loc))));
863 Make_Discriminant_Association (Loc,
864 Selector_Names => New_List (New_Occurrence_Of (Disc, Loc)),
865 Expression => New_Occurrence_Of (Tmp_For_Disc, Loc)));
867 Append_To (Discriminant_Checks,
868 Make_Raise_Constraint_Error (Loc,
871 Left_Opnd => New_Occurrence_Of (Tmp_For_Disc, Loc),
873 Make_Selected_Component (Loc,
874 Prefix => New_Copy_Tree (Out_Formal),
875 Selector_Name => New_Occurrence_Of (Disc, Loc))),
876 Reason => CE_Discriminant_Check_Failed));
877 Next_Discriminant (Disc);
880 -- Generate reads for the components of the record (including
881 -- those that depend on discriminants).
883 Build_Record_Read_Write_Procedure (Loc, Typ, Decl, Pnam, Name_Read);
885 -- If Typ has controlled components (i.e. if it is classwide
886 -- or Has_Controlled), or components constrained using the discriminants
887 -- of Typ, then we need to ensure that all component assignments
888 -- are performed on an object that has been appropriately constrained
889 -- prior to being initialized. To this effect, we wrap the component
890 -- assignments in a block where V is a constrained temporary.
893 Make_Object_Declaration (Loc,
894 Defining_Identifier => Tmp,
896 Make_Subtype_Indication (Loc,
897 Subtype_Mark => New_Occurrence_Of (Typ, Loc),
899 Make_Index_Or_Discriminant_Constraint (Loc,
900 Constraints => Cstr))));
902 Constrained_Stms := Statements (Handled_Statement_Sequence (Decl));
904 Make_Block_Statement (Loc,
905 Declarations => Dcls,
906 Handled_Statement_Sequence => Parent (Constrained_Stms)));
908 Append_To (Constrained_Stms,
909 Make_Implicit_If_Statement (Pnam,
911 Make_Attribute_Reference (Loc,
912 Prefix => New_Copy_Tree (Out_Formal),
913 Attribute_Name => Name_Constrained),
914 Then_Statements => Discriminant_Checks));
916 Append_To (Constrained_Stms,
917 Make_Assignment_Statement (Loc,
919 Expression => Make_Identifier (Loc, Name_V)));
921 if Is_Unchecked_Union (Typ) then
923 -- If this is an unchecked union, the stream procedure is erroneous,
924 -- because there are no discriminants to read.
926 -- This should generate a warning ???
930 Make_Raise_Program_Error (Loc,
931 Reason => PE_Unchecked_Union_Restriction));
934 Set_Declarations (Decl, Tmps_For_Discs);
935 Set_Handled_Statement_Sequence (Decl,
936 Make_Handled_Sequence_Of_Statements (Loc,
937 Statements => Stms));
938 end Build_Mutable_Record_Read_Procedure;
940 ------------------------------------------
941 -- Build_Mutable_Record_Write_Procedure --
942 ------------------------------------------
944 procedure Build_Mutable_Record_Write_Procedure
948 Pnam : out Entity_Id)
955 Disc := First_Discriminant (Typ);
957 -- Generate Writes for the discriminants of the type
959 while Present (Disc) loop
962 Make_Attribute_Reference (Loc,
963 Prefix => New_Occurrence_Of (Etype (Disc), Loc),
964 Attribute_Name => Name_Write,
965 Expressions => New_List (
966 Make_Identifier (Loc, Name_S),
967 Make_Selected_Component (Loc,
968 Prefix => Make_Identifier (Loc, Name_V),
969 Selector_Name => New_Occurrence_Of (Disc, Loc)))));
971 Next_Discriminant (Disc);
974 -- A mutable type cannot be a tagged type, so we generate a new name
975 -- for the stream procedure.
978 Make_Defining_Identifier (Loc,
979 Chars => Make_TSS_Name_Local (Typ, TSS_Stream_Write));
980 Build_Record_Read_Write_Procedure (Loc, Typ, Decl, Pnam, Name_Write);
982 -- Write the discriminants before the rest of the components, so
983 -- that discriminant values are properly set of variants, etc.
984 -- If this is an unchecked union, the stream procedure is erroneous
985 -- because there are no discriminants to write.
987 if Is_Unchecked_Union (Typ) then
990 Make_Raise_Program_Error (Loc,
991 Reason => PE_Unchecked_Union_Restriction));
994 if Is_Non_Empty_List (
995 Statements (Handled_Statement_Sequence (Decl)))
998 (First (Statements (Handled_Statement_Sequence (Decl))), Stms);
1000 Set_Statements (Handled_Statement_Sequence (Decl), Stms);
1002 end Build_Mutable_Record_Write_Procedure;
1004 -----------------------------------------------
1005 -- Build_Record_Or_Elementary_Input_Function --
1006 -----------------------------------------------
1008 -- The function we build looks like
1010 -- function InputN (S : access RST) return Typ is
1011 -- C1 : constant Disc_Type_1;
1012 -- Discr_Type_1'Read (S, C1);
1013 -- C2 : constant Disc_Type_2;
1014 -- Discr_Type_2'Read (S, C2);
1016 -- Cn : constant Disc_Type_n;
1017 -- Discr_Type_n'Read (S, Cn);
1018 -- V : Typ (C1, C2, .. Cn)
1025 -- The discriminants are of course only present in the case of a record
1026 -- with discriminants. In the case of a record with no discriminants, or
1027 -- an elementary type, then no Cn constants are defined.
1029 procedure Build_Record_Or_Elementary_Input_Function
1033 Fnam : out Entity_Id)
1049 if Has_Discriminants (Typ) then
1050 Discr := First_Discriminant (Typ);
1052 while Present (Discr) loop
1053 Cn := New_External_Name ('C', J);
1056 Make_Object_Declaration (Loc,
1057 Defining_Identifier => Make_Defining_Identifier (Loc, Cn),
1058 Object_Definition =>
1059 New_Occurrence_Of (Etype (Discr), Loc)));
1062 Make_Attribute_Reference (Loc,
1063 Prefix => New_Occurrence_Of (Etype (Discr), Loc),
1064 Attribute_Name => Name_Read,
1065 Expressions => New_List (
1066 Make_Identifier (Loc, Name_S),
1067 Make_Identifier (Loc, Cn))));
1069 Append_To (Constr, Make_Identifier (Loc, Cn));
1071 Next_Discriminant (Discr);
1076 Make_Subtype_Indication (Loc,
1077 Subtype_Mark => New_Occurrence_Of (Typ, Loc),
1079 Make_Index_Or_Discriminant_Constraint (Loc,
1080 Constraints => Constr));
1082 -- If no discriminants, then just use the type with no constraint
1085 Odef := New_Occurrence_Of (Typ, Loc);
1089 Make_Object_Declaration (Loc,
1090 Defining_Identifier => Make_Defining_Identifier (Loc, Name_V),
1091 Object_Definition => Odef));
1094 Make_Attribute_Reference (Loc,
1095 Prefix => New_Occurrence_Of (Typ, Loc),
1096 Attribute_Name => Name_Read,
1097 Expressions => New_List (
1098 Make_Identifier (Loc, Name_S),
1099 Make_Identifier (Loc, Name_V))),
1101 Make_Return_Statement (Loc,
1102 Expression => Make_Identifier (Loc, Name_V)));
1104 Fnam := Make_Stream_Subprogram_Name (Loc, Typ, TSS_Stream_Input);
1106 Build_Stream_Function (Loc, Typ, Decl, Fnam, Decls, Stms);
1107 end Build_Record_Or_Elementary_Input_Function;
1109 -------------------------------------------------
1110 -- Build_Record_Or_Elementary_Output_Procedure --
1111 -------------------------------------------------
1113 procedure Build_Record_Or_Elementary_Output_Procedure
1117 Pnam : out Entity_Id)
1125 -- Note that of course there will be no discriminants for the
1126 -- elementary type case, so Has_Discriminants will be False.
1128 if Has_Discriminants (Typ) then
1129 Disc := First_Discriminant (Typ);
1131 while Present (Disc) loop
1133 Make_Attribute_Reference (Loc,
1135 New_Occurrence_Of (Stream_Base_Type (Etype (Disc)), Loc),
1136 Attribute_Name => Name_Write,
1137 Expressions => New_List (
1138 Make_Identifier (Loc, Name_S),
1139 Make_Selected_Component (Loc,
1140 Prefix => Make_Identifier (Loc, Name_V),
1141 Selector_Name => New_Occurrence_Of (Disc, Loc)))));
1143 Next_Discriminant (Disc);
1148 Make_Attribute_Reference (Loc,
1149 Prefix => New_Occurrence_Of (Typ, Loc),
1150 Attribute_Name => Name_Write,
1151 Expressions => New_List (
1152 Make_Identifier (Loc, Name_S),
1153 Make_Identifier (Loc, Name_V))));
1155 Pnam := Make_Stream_Subprogram_Name (Loc, Typ, TSS_Stream_Output);
1157 Build_Stream_Procedure (Loc, Typ, Decl, Pnam, Stms, False);
1158 end Build_Record_Or_Elementary_Output_Procedure;
1160 ---------------------------------
1161 -- Build_Record_Read_Procedure --
1162 ---------------------------------
1164 procedure Build_Record_Read_Procedure
1168 Pnam : out Entity_Id)
1171 Pnam := Make_Stream_Subprogram_Name (Loc, Typ, TSS_Stream_Read);
1172 Build_Record_Read_Write_Procedure (Loc, Typ, Decl, Pnam, Name_Read);
1173 end Build_Record_Read_Procedure;
1175 ---------------------------------------
1176 -- Build_Record_Read_Write_Procedure --
1177 ---------------------------------------
1179 -- The form of the record read/write procedure is as shown by the
1180 -- following example for a case with one discriminant case variant:
1182 -- procedure pnam (S : access RST, V : [out] Typ) is
1184 -- Component_Type'Read/Write (S, V.component);
1185 -- Component_Type'Read/Write (S, V.component);
1187 -- Component_Type'Read/Write (S, V.component);
1189 -- case V.discriminant is
1191 -- Component_Type'Read/Write (S, V.component);
1192 -- Component_Type'Read/Write (S, V.component);
1194 -- Component_Type'Read/Write (S, V.component);
1197 -- Component_Type'Read/Write (S, V.component);
1198 -- Component_Type'Read/Write (S, V.component);
1200 -- Component_Type'Read/Write (S, V.component);
1205 -- The out keyword for V is supplied in the Read case
1207 procedure Build_Record_Read_Write_Procedure
1218 In_Limited_Extension : Boolean := False;
1219 -- Set to True while processing the record extension definition
1220 -- for an extension of a limited type (for which an ancestor type
1221 -- has an explicit Nam attribute definition).
1223 function Make_Component_List_Attributes (CL : Node_Id) return List_Id;
1224 -- Returns a sequence of attributes to process the components that
1225 -- are referenced in the given component list.
1227 function Make_Field_Attribute (C : Entity_Id) return Node_Id;
1228 -- Given C, the entity for a discriminant or component, build
1229 -- an attribute for the corresponding field values.
1231 function Make_Field_Attributes (Clist : List_Id) return List_Id;
1232 -- Given Clist, a component items list, construct series of attributes
1233 -- for fieldwise processing of the corresponding components.
1235 ------------------------------------
1236 -- Make_Component_List_Attributes --
1237 ------------------------------------
1239 function Make_Component_List_Attributes (CL : Node_Id) return List_Id is
1240 CI : constant List_Id := Component_Items (CL);
1241 VP : constant Node_Id := Variant_Part (CL);
1250 Result := Make_Field_Attributes (CI);
1252 -- If a component is an unchecked union, there is no discriminant
1253 -- and we cannot generate a read/write procedure for it.
1255 if Present (VP) then
1256 if Is_Unchecked_Union (Scope (Entity (Name (VP)))) then
1258 Make_Raise_Program_Error (Sloc (VP),
1259 Reason => PE_Unchecked_Union_Restriction));
1262 V := First_Non_Pragma (Variants (VP));
1264 while Present (V) loop
1267 DC := First (Discrete_Choices (V));
1268 while Present (DC) loop
1269 Append_To (DCH, New_Copy_Tree (DC));
1274 Make_Case_Statement_Alternative (Loc,
1275 Discrete_Choices => DCH,
1277 Make_Component_List_Attributes (Component_List (V))));
1278 Next_Non_Pragma (V);
1281 -- Note: in the following, we make sure that we use new occurrence
1282 -- of for the selector, since there are cases in which we make a
1283 -- reference to a hidden discriminant that is not visible.
1286 Make_Case_Statement (Loc,
1288 Make_Selected_Component (Loc,
1289 Prefix => Make_Identifier (Loc, Name_V),
1291 New_Occurrence_Of (Entity (Name (VP)), Loc)),
1292 Alternatives => Alts));
1297 end Make_Component_List_Attributes;
1299 --------------------------
1300 -- Make_Field_Attribute --
1301 --------------------------
1303 function Make_Field_Attribute (C : Entity_Id) return Node_Id is
1304 Field_Typ : constant Entity_Id := Stream_Base_Type (Etype (C));
1306 TSS_Names : constant array (Name_Input .. Name_Write) of
1308 (Name_Read => TSS_Stream_Read,
1309 Name_Write => TSS_Stream_Write,
1310 Name_Input => TSS_Stream_Input,
1311 Name_Output => TSS_Stream_Output,
1312 others => TSS_Null);
1313 pragma Assert (TSS_Names (Nam) /= TSS_Null);
1316 if In_Limited_Extension
1317 and then Is_Limited_Type (Field_Typ)
1318 and then No (Find_Inherited_TSS (Field_Typ, TSS_Names (Nam)))
1320 -- The declaration is illegal per 13.13.2(9/1), and this is
1321 -- enforced in Exp_Ch3.Check_Stream_Attributes. Keep the
1322 -- caller happy by returning a null statement.
1324 return Make_Null_Statement (Loc);
1328 Make_Attribute_Reference (Loc,
1330 New_Occurrence_Of (Stream_Base_Type (Etype (C)), Loc),
1331 Attribute_Name => Nam,
1332 Expressions => New_List (
1333 Make_Identifier (Loc, Name_S),
1334 Make_Selected_Component (Loc,
1335 Prefix => Make_Identifier (Loc, Name_V),
1336 Selector_Name => New_Occurrence_Of (C, Loc))));
1337 end Make_Field_Attribute;
1339 ---------------------------
1340 -- Make_Field_Attributes --
1341 ---------------------------
1343 function Make_Field_Attributes (Clist : List_Id) return List_Id is
1350 if Present (Clist) then
1351 Item := First (Clist);
1353 -- Loop through components, skipping all internal components,
1354 -- which are not part of the value (e.g. _Tag), except that we
1355 -- don't skip the _Parent, since we do want to process that
1358 while Present (Item) loop
1359 if Nkind (Item) = N_Component_Declaration
1361 (Chars (Defining_Identifier (Item)) = Name_uParent
1363 not Is_Internal_Name (Chars (Defining_Identifier (Item))))
1367 Make_Field_Attribute (Defining_Identifier (Item)));
1375 end Make_Field_Attributes;
1377 -- Start of processing for Build_Record_Read_Write_Procedure
1380 -- For the protected type case, use corresponding record
1382 if Is_Protected_Type (Typ) then
1383 Typt := Corresponding_Record_Type (Typ);
1388 -- Note that we do nothing with the discriminants, since Read and
1389 -- Write do not read or write the discriminant values. All handling
1390 -- of discriminants occurs in the Input and Output subprograms.
1392 Rdef := Type_Definition
1393 (Declaration_Node (Base_Type (Underlying_Type (Typt))));
1396 -- In record extension case, the fields we want, including the _Parent
1397 -- field representing the parent type, are to be found in the extension.
1398 -- Note that we will naturally process the _Parent field using the type
1399 -- of the parent, and hence its stream attributes, which is appropriate.
1401 if Nkind (Rdef) = N_Derived_Type_Definition then
1402 Rdef := Record_Extension_Part (Rdef);
1404 if Is_Limited_Type (Typt) then
1405 In_Limited_Extension := True;
1409 if Present (Component_List (Rdef)) then
1410 Append_List_To (Stms,
1411 Make_Component_List_Attributes (Component_List (Rdef)));
1414 Build_Stream_Procedure
1415 (Loc, Typ, Decl, Pnam, Stms, Nam = Name_Read);
1416 end Build_Record_Read_Write_Procedure;
1418 ----------------------------------
1419 -- Build_Record_Write_Procedure --
1420 ----------------------------------
1422 procedure Build_Record_Write_Procedure
1426 Pnam : out Entity_Id)
1429 Pnam := Make_Stream_Subprogram_Name (Loc, Typ, TSS_Stream_Write);
1430 Build_Record_Read_Write_Procedure (Loc, Typ, Decl, Pnam, Name_Write);
1431 end Build_Record_Write_Procedure;
1433 -------------------------------
1434 -- Build_Stream_Attr_Profile --
1435 -------------------------------
1437 function Build_Stream_Attr_Profile
1440 Nam : TSS_Name_Type) return List_Id
1445 Profile := New_List (
1446 Make_Parameter_Specification (Loc,
1447 Defining_Identifier => Make_Defining_Identifier (Loc, Name_S),
1449 Make_Access_Definition (Loc,
1450 Subtype_Mark => New_Reference_To (
1451 Class_Wide_Type (RTE (RE_Root_Stream_Type)), Loc))));
1453 if Nam /= TSS_Stream_Input then
1455 Make_Parameter_Specification (Loc,
1456 Defining_Identifier => Make_Defining_Identifier (Loc, Name_V),
1457 Out_Present => (Nam = TSS_Stream_Read),
1458 Parameter_Type => New_Reference_To (Typ, Loc)));
1462 end Build_Stream_Attr_Profile;
1464 ---------------------------
1465 -- Build_Stream_Function --
1466 ---------------------------
1468 procedure Build_Stream_Function
1479 -- Construct function specification
1482 Make_Function_Specification (Loc,
1483 Defining_Unit_Name => Fnam,
1485 Parameter_Specifications => New_List (
1486 Make_Parameter_Specification (Loc,
1487 Defining_Identifier => Make_Defining_Identifier (Loc, Name_S),
1489 Make_Access_Definition (Loc,
1490 Subtype_Mark => New_Reference_To (
1491 Class_Wide_Type (RTE (RE_Root_Stream_Type)), Loc)))),
1493 Subtype_Mark => New_Occurrence_Of (Typ, Loc));
1496 Make_Subprogram_Body (Loc,
1497 Specification => Spec,
1498 Declarations => Decls,
1499 Handled_Statement_Sequence =>
1500 Make_Handled_Sequence_Of_Statements (Loc,
1501 Statements => Stms));
1502 end Build_Stream_Function;
1504 ----------------------------
1505 -- Build_Stream_Procedure --
1506 ----------------------------
1508 procedure Build_Stream_Procedure
1519 -- Construct procedure specification
1522 Make_Procedure_Specification (Loc,
1523 Defining_Unit_Name => Pnam,
1525 Parameter_Specifications => New_List (
1526 Make_Parameter_Specification (Loc,
1527 Defining_Identifier => Make_Defining_Identifier (Loc, Name_S),
1529 Make_Access_Definition (Loc,
1530 Subtype_Mark => New_Reference_To (
1531 Class_Wide_Type (RTE (RE_Root_Stream_Type)), Loc))),
1533 Make_Parameter_Specification (Loc,
1534 Defining_Identifier => Make_Defining_Identifier (Loc, Name_V),
1535 Out_Present => Outp,
1536 Parameter_Type => New_Occurrence_Of (Typ, Loc))));
1539 Make_Subprogram_Body (Loc,
1540 Specification => Spec,
1541 Declarations => Empty_List,
1542 Handled_Statement_Sequence =>
1543 Make_Handled_Sequence_Of_Statements (Loc,
1544 Statements => Stms));
1545 end Build_Stream_Procedure;
1547 -----------------------------
1548 -- Has_Stream_Standard_Rep --
1549 -----------------------------
1551 function Has_Stream_Standard_Rep (U_Type : Entity_Id) return Boolean is
1553 if Has_Non_Standard_Rep (U_Type) then
1557 Esize (First_Subtype (U_Type)) = Esize (Root_Type (U_Type));
1559 end Has_Stream_Standard_Rep;
1561 ---------------------------------
1562 -- Make_Stream_Subprogram_Name --
1563 ---------------------------------
1565 function Make_Stream_Subprogram_Name
1568 Nam : TSS_Name_Type) return Entity_Id
1573 -- For tagged types, we are dealing with a TSS associated with the
1574 -- declaration, so we use the standard primitive function name. For
1575 -- other types, generate a local TSS name since we are generating
1576 -- the subprogram at the point of use.
1578 if Is_Tagged_Type (Typ) then
1579 Sname := Make_TSS_Name (Typ, Nam);
1581 Sname := Make_TSS_Name_Local (Typ, Nam);
1584 return Make_Defining_Identifier (Loc, Sname);
1585 end Make_Stream_Subprogram_Name;
1587 ----------------------
1588 -- Stream_Base_Type --
1589 ----------------------
1591 function Stream_Base_Type (E : Entity_Id) return Entity_Id is
1593 if Is_Array_Type (E)
1594 and then Is_First_Subtype (E)
1598 return Base_Type (E);
1600 end Stream_Base_Type;