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PR c++/79377
[official-gcc.git] / gcc / ada / exp_strm.adb
blob20a7a7db5d9e8d9d726f82f66cdf02a27164ec40
1 ------------------------------------------------------------------------------
2 -- --
3 -- GNAT COMPILER COMPONENTS --
4 -- --
5 -- E X P _ S T R M --
6 -- --
7 -- B o d y --
8 -- --
9 -- Copyright (C) 1992-2016, 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
26 with Atree; use Atree;
27 with Einfo; use Einfo;
28 with Elists; use Elists;
29 with Exp_Util; use Exp_Util;
30 with Namet; use Namet;
31 with Nlists; use Nlists;
32 with Nmake; use Nmake;
33 with Rtsfind; use Rtsfind;
34 with Sem_Aux; use Sem_Aux;
35 with Sem_Util; use Sem_Util;
36 with Sinfo; use Sinfo;
37 with Snames; use Snames;
38 with Stand; use Stand;
39 with Tbuild; use Tbuild;
40 with Ttypes; use Ttypes;
41 with Uintp; use Uintp;
42
43 package body Exp_Strm is
44
45 -----------------------
46 -- Local Subprograms --
47 -----------------------
48
49 procedure Build_Array_Read_Write_Procedure
50 (Nod : Node_Id;
51 Typ : Entity_Id;
52 Decl : out Node_Id;
53 Pnam : Entity_Id;
54 Nam : Name_Id);
55 -- Common routine shared to build either an array Read procedure or an
56 -- array Write procedure, Nam is Name_Read or Name_Write to select which.
57 -- Pnam is the defining identifier for the constructed procedure. The
58 -- other parameters are as for Build_Array_Read_Procedure except that
59 -- the first parameter Nod supplies the Sloc to be used to generate code.
60
61 procedure Build_Record_Read_Write_Procedure
62 (Loc : Source_Ptr;
63 Typ : Entity_Id;
64 Decl : out Node_Id;
65 Pnam : Entity_Id;
66 Nam : Name_Id);
67 -- Common routine shared to build a record Read Write procedure, Nam
68 -- is Name_Read or Name_Write to select which. Pnam is the defining
69 -- identifier for the constructed procedure. The other parameters are
70 -- as for Build_Record_Read_Procedure.
71
72 procedure Build_Stream_Function
73 (Loc : Source_Ptr;
74 Typ : Entity_Id;
75 Decl : out Node_Id;
76 Fnam : Entity_Id;
77 Decls : List_Id;
78 Stms : List_Id);
79 -- Called to build an array or record stream function. The first three
80 -- arguments are the same as Build_Record_Or_Elementary_Input_Function.
81 -- Decls and Stms are the declarations and statements for the body and
82 -- The parameter Fnam is the name of the constructed function.
83
84 function Has_Stream_Standard_Rep (U_Type : Entity_Id) return Boolean;
85 -- This function is used to test the type U_Type, to determine if it has
86 -- a standard representation from a streaming point of view. Standard means
87 -- that it has a standard representation (e.g. no enumeration rep clause),
88 -- and the size of the root type is the same as the streaming size (which
89 -- is defined as value specified by a Stream_Size clause if present, or
90 -- the Esize of U_Type if not).
91
92 function Make_Stream_Subprogram_Name
93 (Loc : Source_Ptr;
94 Typ : Entity_Id;
95 Nam : TSS_Name_Type) return Entity_Id;
96 -- Return the entity that identifies the stream subprogram for type Typ
97 -- that is identified by the given Nam. This procedure deals with the
98 -- difference between tagged types (where a single subprogram associated
99 -- with the type is generated) and all other cases (where a subprogram
100 -- is generated at the point of the stream attribute reference). The
101 -- Loc parameter is used as the Sloc of the created entity.
102
103 function Stream_Base_Type (E : Entity_Id) return Entity_Id;
104 -- Stream attributes work on the basis of the base type except for the
105 -- array case. For the array case, we do not go to the base type, but
106 -- to the first subtype if it is constrained. This avoids problems with
107 -- incorrect conversions in the packed array case. Stream_Base_Type is
108 -- exactly this function (returns the base type, unless we have an array
109 -- type whose first subtype is constrained, in which case it returns the
110 -- first subtype).
111
112 --------------------------------
113 -- Build_Array_Input_Function --
114 --------------------------------
115
116 -- The function we build looks like
117
118 -- function typSI[_nnn] (S : access RST) return Typ is
119 -- L1 : constant Index_Type_1 := Index_Type_1'Input (S);
120 -- H1 : constant Index_Type_1 := Index_Type_1'Input (S);
121 -- L2 : constant Index_Type_2 := Index_Type_2'Input (S);
122 -- H2 : constant Index_Type_2 := Index_Type_2'Input (S);
123 -- ..
124 -- Ln : constant Index_Type_n := Index_Type_n'Input (S);
125 -- Hn : constant Index_Type_n := Index_Type_n'Input (S);
126 --
127 -- V : Typ'Base (L1 .. H1, L2 .. H2, ... Ln .. Hn)
128
129 -- begin
130 -- Typ'Read (S, V);
131 -- return V;
132 -- end typSI[_nnn]
133
134 -- Note: the suffix [_nnn] is present for untagged types, where we generate
135 -- a local subprogram at the point of the occurrence of the attribute
136 -- reference, so the name must be unique.
137
138 procedure Build_Array_Input_Function
139 (Loc : Source_Ptr;
140 Typ : Entity_Id;
141 Decl : out Node_Id;
142 Fnam : out Entity_Id)
143 is
144 Dim : constant Pos := Number_Dimensions (Typ);
145 Lnam : Name_Id;
146 Hnam : Name_Id;
147 Decls : List_Id;
148 Ranges : List_Id;
149 Stms : List_Id;
150 Rstmt : Node_Id;
151 Indx : Node_Id;
152 Odecl : Node_Id;
153
154 begin
155 Decls := New_List;
156 Ranges := New_List;
157 Indx := First_Index (Typ);
158 for J in 1 .. Dim loop
159 Lnam := New_External_Name ('L', J);
160 Hnam := New_External_Name ('H', J);
161
162 Append_To (Decls,
163 Make_Object_Declaration (Loc,
164 Defining_Identifier => Make_Defining_Identifier (Loc, Lnam),
165 Constant_Present => True,
166 Object_Definition => New_Occurrence_Of (Etype (Indx), Loc),
167 Expression =>
168 Make_Attribute_Reference (Loc,
169 Prefix =>
170 New_Occurrence_Of (Stream_Base_Type (Etype (Indx)), Loc),
171 Attribute_Name => Name_Input,
172 Expressions => New_List (Make_Identifier (Loc, Name_S)))));
173
174 Append_To (Decls,
175 Make_Object_Declaration (Loc,
176 Defining_Identifier => Make_Defining_Identifier (Loc, Hnam),
177 Constant_Present => True,
178 Object_Definition =>
179 New_Occurrence_Of (Stream_Base_Type (Etype (Indx)), Loc),
180 Expression =>
181 Make_Attribute_Reference (Loc,
182 Prefix =>
183 New_Occurrence_Of (Stream_Base_Type (Etype (Indx)), Loc),
184 Attribute_Name => Name_Input,
185 Expressions => New_List (Make_Identifier (Loc, Name_S)))));
186
187 Append_To (Ranges,
188 Make_Range (Loc,
189 Low_Bound => Make_Identifier (Loc, Lnam),
190 High_Bound => Make_Identifier (Loc, Hnam)));
191
192 Next_Index (Indx);
193 end loop;
194
195 -- If the type is constrained, use it directly. Otherwise build a
196 -- subtype indication with the proper bounds.
197
198 if Is_Constrained (Typ) then
199 Odecl :=
200 Make_Object_Declaration (Loc,
201 Defining_Identifier => Make_Defining_Identifier (Loc, Name_V),
202 Object_Definition => New_Occurrence_Of (Typ, Loc));
203
204 else
205 Odecl :=
206 Make_Object_Declaration (Loc,
207 Defining_Identifier => Make_Defining_Identifier (Loc, Name_V),
208 Object_Definition =>
209 Make_Subtype_Indication (Loc,
210 Subtype_Mark =>
211 New_Occurrence_Of (Stream_Base_Type (Typ), Loc),
212 Constraint =>
213 Make_Index_Or_Discriminant_Constraint (Loc, Ranges)));
214 end if;
215
216 Rstmt :=
217 Make_Attribute_Reference (Loc,
218 Prefix => New_Occurrence_Of (Typ, Loc),
219 Attribute_Name => Name_Read,
220 Expressions => New_List (
221 Make_Identifier (Loc, Name_S),
222 Make_Identifier (Loc, Name_V)));
223
224 Stms := New_List (
225 Make_Extended_Return_Statement (Loc,
226 Return_Object_Declarations => New_List (Odecl),
227 Handled_Statement_Sequence =>
228 Make_Handled_Sequence_Of_Statements (Loc, New_List (Rstmt))));
229
230 Fnam :=
231 Make_Defining_Identifier (Loc,
232 Chars => Make_TSS_Name_Local (Typ, TSS_Stream_Input));
233
234 Build_Stream_Function (Loc, Typ, Decl, Fnam, Decls, Stms);
235 end Build_Array_Input_Function;
236
237 ----------------------------------
238 -- Build_Array_Output_Procedure --
239 ----------------------------------
240
241 procedure Build_Array_Output_Procedure
242 (Loc : Source_Ptr;
243 Typ : Entity_Id;
244 Decl : out Node_Id;
245 Pnam : out Entity_Id)
246 is
247 Stms : List_Id;
248 Indx : Node_Id;
249
250 begin
251 -- Build series of statements to output bounds
252
253 Indx := First_Index (Typ);
254 Stms := New_List;
255
256 for J in 1 .. Number_Dimensions (Typ) loop
257 Append_To (Stms,
258 Make_Attribute_Reference (Loc,
259 Prefix =>
260 New_Occurrence_Of (Stream_Base_Type (Etype (Indx)), Loc),
261 Attribute_Name => Name_Write,
262 Expressions => New_List (
263 Make_Identifier (Loc, Name_S),
264 Make_Attribute_Reference (Loc,
265 Prefix => Make_Identifier (Loc, Name_V),
266 Attribute_Name => Name_First,
267 Expressions => New_List (
268 Make_Integer_Literal (Loc, J))))));
269
270 Append_To (Stms,
271 Make_Attribute_Reference (Loc,
272 Prefix =>
273 New_Occurrence_Of (Stream_Base_Type (Etype (Indx)), Loc),
274 Attribute_Name => Name_Write,
275 Expressions => New_List (
276 Make_Identifier (Loc, Name_S),
277 Make_Attribute_Reference (Loc,
278 Prefix => Make_Identifier (Loc, Name_V),
279 Attribute_Name => Name_Last,
280 Expressions => New_List (
281 Make_Integer_Literal (Loc, J))))));
282
283 Next_Index (Indx);
284 end loop;
285
286 -- Append Write attribute to write array elements
287
288 Append_To (Stms,
289 Make_Attribute_Reference (Loc,
290 Prefix => New_Occurrence_Of (Typ, Loc),
291 Attribute_Name => Name_Write,
292 Expressions => New_List (
293 Make_Identifier (Loc, Name_S),
294 Make_Identifier (Loc, Name_V))));
295
296 Pnam :=
297 Make_Defining_Identifier (Loc,
298 Chars => Make_TSS_Name_Local (Typ, TSS_Stream_Output));
299
300 Build_Stream_Procedure (Loc, Typ, Decl, Pnam, Stms, False);
301 end Build_Array_Output_Procedure;
302
303 --------------------------------
304 -- Build_Array_Read_Procedure --
305 --------------------------------
306
307 procedure Build_Array_Read_Procedure
308 (Nod : Node_Id;
309 Typ : Entity_Id;
310 Decl : out Node_Id;
311 Pnam : out Entity_Id)
312 is
313 Loc : constant Source_Ptr := Sloc (Nod);
314
315 begin
316 Pnam :=
317 Make_Defining_Identifier (Loc,
318 Chars => Make_TSS_Name_Local (Typ, TSS_Stream_Read));
319 Build_Array_Read_Write_Procedure (Nod, Typ, Decl, Pnam, Name_Read);
320 end Build_Array_Read_Procedure;
321
322 --------------------------------------
323 -- Build_Array_Read_Write_Procedure --
324 --------------------------------------
325
326 -- The form of the array read/write procedure is as follows:
327
328 -- procedure pnam (S : access RST, V : [out] Typ) is
329 -- begin
330 -- for L1 in V'Range (1) loop
331 -- for L2 in V'Range (2) loop
332 -- ...
333 -- for Ln in V'Range (n) loop
334 -- Component_Type'Read/Write (S, V (L1, L2, .. Ln));
335 -- end loop;
336 -- ..
337 -- end loop;
338 -- end loop
339 -- end pnam;
340
341 -- The out keyword for V is supplied in the Read case
342
343 procedure Build_Array_Read_Write_Procedure
344 (Nod : Node_Id;
345 Typ : Entity_Id;
346 Decl : out Node_Id;
347 Pnam : Entity_Id;
348 Nam : Name_Id)
349 is
350 Loc : constant Source_Ptr := Sloc (Nod);
351 Ndim : constant Pos := Number_Dimensions (Typ);
352 Ctyp : constant Entity_Id := Component_Type (Typ);
353
354 Stm : Node_Id;
355 Exl : List_Id;
356 RW : Entity_Id;
357
358 begin
359 -- First build the inner attribute call
360
361 Exl := New_List;
362
363 for J in 1 .. Ndim loop
364 Append_To (Exl, Make_Identifier (Loc, New_External_Name ('L', J)));
365 end loop;
366
367 Stm :=
368 Make_Attribute_Reference (Loc,
369 Prefix => New_Occurrence_Of (Stream_Base_Type (Ctyp), Loc),
370 Attribute_Name => Nam,
371 Expressions => New_List (
372 Make_Identifier (Loc, Name_S),
373 Make_Indexed_Component (Loc,
374 Prefix => Make_Identifier (Loc, Name_V),
375 Expressions => Exl)));
376
377 -- The corresponding stream attribute for the component type of the
378 -- array may be user-defined, and be frozen after the type for which
379 -- we are generating the stream subprogram. In that case, freeze the
380 -- stream attribute of the component type, whose declaration could not
381 -- generate any additional freezing actions in any case.
382
383 if Nam = Name_Read then
384 RW := TSS (Base_Type (Ctyp), TSS_Stream_Read);
385 else
386 RW := TSS (Base_Type (Ctyp), TSS_Stream_Write);
387 end if;
388
389 if Present (RW)
390 and then not Is_Frozen (RW)
391 then
392 Set_Is_Frozen (RW);
393 end if;
394
395 -- Now this is the big loop to wrap that statement up in a sequence
396 -- of loops. The first time around, Stm is the attribute call. The
397 -- second and subsequent times, Stm is an inner loop.
398
399 for J in 1 .. Ndim loop
400 Stm :=
401 Make_Implicit_Loop_Statement (Nod,
402 Iteration_Scheme =>
403 Make_Iteration_Scheme (Loc,
404 Loop_Parameter_Specification =>
405 Make_Loop_Parameter_Specification (Loc,
406 Defining_Identifier =>
407 Make_Defining_Identifier (Loc,
408 Chars => New_External_Name ('L', Ndim - J + 1)),
409
410 Discrete_Subtype_Definition =>
411 Make_Attribute_Reference (Loc,
412 Prefix => Make_Identifier (Loc, Name_V),
413 Attribute_Name => Name_Range,
414
415 Expressions => New_List (
416 Make_Integer_Literal (Loc, Ndim - J + 1))))),
417
418 Statements => New_List (Stm));
419
420 end loop;
421
422 Build_Stream_Procedure
423 (Loc, Typ, Decl, Pnam, New_List (Stm), Nam = Name_Read);
424 end Build_Array_Read_Write_Procedure;
425
426 ---------------------------------
427 -- Build_Array_Write_Procedure --
428 ---------------------------------
429
430 procedure Build_Array_Write_Procedure
431 (Nod : Node_Id;
432 Typ : Entity_Id;
433 Decl : out Node_Id;
434 Pnam : out Entity_Id)
435 is
436 Loc : constant Source_Ptr := Sloc (Nod);
437 begin
438 Pnam :=
439 Make_Defining_Identifier (Loc,
440 Chars => Make_TSS_Name_Local (Typ, TSS_Stream_Write));
441 Build_Array_Read_Write_Procedure (Nod, Typ, Decl, Pnam, Name_Write);
442 end Build_Array_Write_Procedure;
443
444 ---------------------------------
445 -- Build_Elementary_Input_Call --
446 ---------------------------------
447
448 function Build_Elementary_Input_Call (N : Node_Id) return Node_Id is
449 Loc : constant Source_Ptr := Sloc (N);
450 P_Type : constant Entity_Id := Entity (Prefix (N));
451 U_Type : constant Entity_Id := Underlying_Type (P_Type);
452 Rt_Type : constant Entity_Id := Root_Type (U_Type);
453 FST : constant Entity_Id := First_Subtype (U_Type);
454 Strm : constant Node_Id := First (Expressions (N));
455 Targ : constant Node_Id := Next (Strm);
456 P_Size : constant Uint := Get_Stream_Size (FST);
457 Res : Node_Id;
458 Lib_RE : RE_Id;
459
460 begin
461
462 -- Check first for Boolean and Character. These are enumeration types,
463 -- but we treat them specially, since they may require special handling
464 -- in the transfer protocol. However, this special handling only applies
465 -- if they have standard representation, otherwise they are treated like
466 -- any other enumeration type.
467
468 if Rt_Type = Standard_Boolean
469 and then Has_Stream_Standard_Rep (U_Type)
470 then
471 Lib_RE := RE_I_B;
472
473 elsif Rt_Type = Standard_Character
474 and then Has_Stream_Standard_Rep (U_Type)
475 then
476 Lib_RE := RE_I_C;
477
478 elsif Rt_Type = Standard_Wide_Character
479 and then Has_Stream_Standard_Rep (U_Type)
480 then
481 Lib_RE := RE_I_WC;
482
483 elsif Rt_Type = Standard_Wide_Wide_Character
484 and then Has_Stream_Standard_Rep (U_Type)
485 then
486 Lib_RE := RE_I_WWC;
487
488 -- Floating point types
489
490 elsif Is_Floating_Point_Type (U_Type) then
491
492 -- Question: should we use P_Size or Rt_Type to distinguish between
493 -- possible floating point types? If a non-standard size or a stream
494 -- size is specified, then we should certainly use the size. But if
495 -- we have two types the same (notably Short_Float_Size = Float_Size
496 -- which is close to universally true, and Long_Long_Float_Size =
497 -- Long_Float_Size, true on most targets except the x86), then we
498 -- would really rather use the root type, so that if people want to
499 -- fiddle with System.Stream_Attributes to get inter-target portable
500 -- streams, they get the size they expect. Consider in particular the
501 -- case of a stream written on an x86, with 96-bit Long_Long_Float
502 -- being read into a non-x86 target with 64 bit Long_Long_Float. A
503 -- special version of System.Stream_Attributes can deal with this
504 -- provided the proper type is always used.
505
506 -- To deal with these two requirements we add the special checks
507 -- on equal sizes and use the root type to distinguish.
508
509 if P_Size <= Standard_Short_Float_Size
510 and then (Standard_Short_Float_Size /= Standard_Float_Size
511 or else Rt_Type = Standard_Short_Float)
512 then
513 Lib_RE := RE_I_SF;
514
515 elsif P_Size <= Standard_Float_Size then
516 Lib_RE := RE_I_F;
517
518 elsif P_Size <= Standard_Long_Float_Size
519 and then (Standard_Long_Float_Size /= Standard_Long_Long_Float_Size
520 or else Rt_Type = Standard_Long_Float)
521 then
522 Lib_RE := RE_I_LF;
523
524 else
525 Lib_RE := RE_I_LLF;
526 end if;
527
528 -- Signed integer types. Also includes signed fixed-point types and
529 -- enumeration types with a signed representation.
530
531 -- Note on signed integer types. We do not consider types as signed for
532 -- this purpose if they have no negative numbers, or if they have biased
533 -- representation. The reason is that the value in either case basically
534 -- represents an unsigned value.
535
536 -- For example, consider:
537
538 -- type W is range 0 .. 2**32 - 1;
539 -- for W'Size use 32;
540
541 -- This is a signed type, but the representation is unsigned, and may
542 -- be outside the range of a 32-bit signed integer, so this must be
543 -- treated as 32-bit unsigned.
544
545 -- Similarly, if we have
546
547 -- type W is range -1 .. +254;
548 -- for W'Size use 8;
549
550 -- then the representation is unsigned
551
552 elsif not Is_Unsigned_Type (FST)
553
554 -- The following set of tests gets repeated many times, we should
555 -- have an abstraction defined ???
556
557 and then
558 (Is_Fixed_Point_Type (U_Type)
559 or else
560 Is_Enumeration_Type (U_Type)
561 or else
562 (Is_Signed_Integer_Type (U_Type)
563 and then not Has_Biased_Representation (FST)))
564
565 then
566 if P_Size <= Standard_Short_Short_Integer_Size then
567 Lib_RE := RE_I_SSI;
568
569 elsif P_Size <= Standard_Short_Integer_Size then
570 Lib_RE := RE_I_SI;
571
572 elsif P_Size <= Standard_Integer_Size then
573 Lib_RE := RE_I_I;
574
575 elsif P_Size <= Standard_Long_Integer_Size then
576 Lib_RE := RE_I_LI;
577
578 else
579 Lib_RE := RE_I_LLI;
580 end if;
581
582 -- Unsigned integer types, also includes unsigned fixed-point types
583 -- and enumeration types with an unsigned representation (note that
584 -- we know they are unsigned because we already tested for signed).
585
586 -- Also includes signed integer types that are unsigned in the sense
587 -- that they do not include negative numbers. See above for details.
588
589 elsif Is_Modular_Integer_Type (U_Type)
590 or else Is_Fixed_Point_Type (U_Type)
591 or else Is_Enumeration_Type (U_Type)
592 or else Is_Signed_Integer_Type (U_Type)
593 then
594 if P_Size <= Standard_Short_Short_Integer_Size then
595 Lib_RE := RE_I_SSU;
596
597 elsif P_Size <= Standard_Short_Integer_Size then
598 Lib_RE := RE_I_SU;
599
600 elsif P_Size <= Standard_Integer_Size then
601 Lib_RE := RE_I_U;
602
603 elsif P_Size <= Standard_Long_Integer_Size then
604 Lib_RE := RE_I_LU;
605
606 else
607 Lib_RE := RE_I_LLU;
608 end if;
609
610 else pragma Assert (Is_Access_Type (U_Type));
611 if P_Size > System_Address_Size then
612 Lib_RE := RE_I_AD;
613 else
614 Lib_RE := RE_I_AS;
615 end if;
616 end if;
617
618 -- Call the function, and do an unchecked conversion of the result
619 -- to the actual type of the prefix. If the target is a discriminant,
620 -- and we are in the body of the default implementation of a 'Read
621 -- attribute, set target type to force a constraint check (13.13.2(35)).
622 -- If the type of the discriminant is currently private, add another
623 -- unchecked conversion from the full view.
624
625 if Nkind (Targ) = N_Identifier
626 and then Is_Internal_Name (Chars (Targ))
627 and then Is_TSS (Scope (Entity (Targ)), TSS_Stream_Read)
628 then
629 Res :=
630 Unchecked_Convert_To (Base_Type (U_Type),
631 Make_Function_Call (Loc,
632 Name => New_Occurrence_Of (RTE (Lib_RE), Loc),
633 Parameter_Associations => New_List (
634 Relocate_Node (Strm))));
635
636 Set_Do_Range_Check (Res);
637
638 if Base_Type (P_Type) /= Base_Type (U_Type) then
639 Res := Unchecked_Convert_To (Base_Type (P_Type), Res);
640 end if;
641
642 return Res;
643
644 else
645 Res :=
646 Make_Function_Call (Loc,
647 Name => New_Occurrence_Of (RTE (Lib_RE), Loc),
648 Parameter_Associations => New_List (
649 Relocate_Node (Strm)));
650
651 -- Now convert to the base type if we do not have a biased type. Note
652 -- that we did not do this in some older versions, and the result was
653 -- losing a required range check in the case where 'Input is being
654 -- called from 'Read.
655
656 if not Has_Biased_Representation (P_Type) then
657 return Unchecked_Convert_To (Base_Type (P_Type), Res);
658
659 -- For the biased case, the conversion to the base type loses the
660 -- biasing, so just convert to Ptype. This is not quite right, and
661 -- for example may lose a corner case CE test, but it is such a
662 -- rare case that for now we ignore it ???
663
664 else
665 return Unchecked_Convert_To (P_Type, Res);
666 end if;
667 end if;
668 end Build_Elementary_Input_Call;
669
670 ---------------------------------
671 -- Build_Elementary_Write_Call --
672 ---------------------------------
673
674 function Build_Elementary_Write_Call (N : Node_Id) return Node_Id is
675 Loc : constant Source_Ptr := Sloc (N);
676 P_Type : constant Entity_Id := Entity (Prefix (N));
677 U_Type : constant Entity_Id := Underlying_Type (P_Type);
678 Rt_Type : constant Entity_Id := Root_Type (U_Type);
679 FST : constant Entity_Id := First_Subtype (U_Type);
680 Strm : constant Node_Id := First (Expressions (N));
681 Item : constant Node_Id := Next (Strm);
682 P_Size : Uint;
683 Lib_RE : RE_Id;
684 Libent : Entity_Id;
685
686 begin
687 -- Compute the size of the stream element. This is either the size of
688 -- the first subtype or if given the size of the Stream_Size attribute.
689
690 if Has_Stream_Size_Clause (FST) then
691 P_Size := Static_Integer (Expression (Stream_Size_Clause (FST)));
692 else
693 P_Size := Esize (FST);
694 end if;
695
696 -- Find the routine to be called
697
698 -- Check for First Boolean and Character. These are enumeration types,
699 -- but we treat them specially, since they may require special handling
700 -- in the transfer protocol. However, this special handling only applies
701 -- if they have standard representation, otherwise they are treated like
702 -- any other enumeration type.
703
704 if Rt_Type = Standard_Boolean
705 and then Has_Stream_Standard_Rep (U_Type)
706 then
707 Lib_RE := RE_W_B;
708
709 elsif Rt_Type = Standard_Character
710 and then Has_Stream_Standard_Rep (U_Type)
711 then
712 Lib_RE := RE_W_C;
713
714 elsif Rt_Type = Standard_Wide_Character
715 and then Has_Stream_Standard_Rep (U_Type)
716 then
717 Lib_RE := RE_W_WC;
718
719 elsif Rt_Type = Standard_Wide_Wide_Character
720 and then Has_Stream_Standard_Rep (U_Type)
721 then
722 Lib_RE := RE_W_WWC;
723
724 -- Floating point types
725
726 elsif Is_Floating_Point_Type (U_Type) then
727
728 -- Question: should we use P_Size or Rt_Type to distinguish between
729 -- possible floating point types? If a non-standard size or a stream
730 -- size is specified, then we should certainly use the size. But if
731 -- we have two types the same (notably Short_Float_Size = Float_Size
732 -- which is close to universally true, and Long_Long_Float_Size =
733 -- Long_Float_Size, true on most targets except the x86), then we
734 -- would really rather use the root type, so that if people want to
735 -- fiddle with System.Stream_Attributes to get inter-target portable
736 -- streams, they get the size they expect. Consider in particular the
737 -- case of a stream written on an x86, with 96-bit Long_Long_Float
738 -- being read into a non-x86 target with 64 bit Long_Long_Float. A
739 -- special version of System.Stream_Attributes can deal with this
740 -- provided the proper type is always used.
741
742 -- To deal with these two requirements we add the special checks
743 -- on equal sizes and use the root type to distinguish.
744
745 if P_Size <= Standard_Short_Float_Size
746 and then (Standard_Short_Float_Size /= Standard_Float_Size
747 or else Rt_Type = Standard_Short_Float)
748 then
749 Lib_RE := RE_W_SF;
750
751 elsif P_Size <= Standard_Float_Size then
752 Lib_RE := RE_W_F;
753
754 elsif P_Size <= Standard_Long_Float_Size
755 and then (Standard_Long_Float_Size /= Standard_Long_Long_Float_Size
756 or else Rt_Type = Standard_Long_Float)
757 then
758 Lib_RE := RE_W_LF;
759
760 else
761 Lib_RE := RE_W_LLF;
762 end if;
763
764 -- Signed integer types. Also includes signed fixed-point types and
765 -- signed enumeration types share this circuitry.
766
767 -- Note on signed integer types. We do not consider types as signed for
768 -- this purpose if they have no negative numbers, or if they have biased
769 -- representation. The reason is that the value in either case basically
770 -- represents an unsigned value.
771
772 -- For example, consider:
773
774 -- type W is range 0 .. 2**32 - 1;
775 -- for W'Size use 32;
776
777 -- This is a signed type, but the representation is unsigned, and may
778 -- be outside the range of a 32-bit signed integer, so this must be
779 -- treated as 32-bit unsigned.
780
781 -- Similarly, the representation is also unsigned if we have:
782
783 -- type W is range -1 .. +254;
784 -- for W'Size use 8;
785
786 -- forcing a biased and unsigned representation
787
788 elsif not Is_Unsigned_Type (FST)
789 and then
790 (Is_Fixed_Point_Type (U_Type)
791 or else
792 Is_Enumeration_Type (U_Type)
793 or else
794 (Is_Signed_Integer_Type (U_Type)
795 and then not Has_Biased_Representation (FST)))
796 then
797 if P_Size <= Standard_Short_Short_Integer_Size then
798 Lib_RE := RE_W_SSI;
799 elsif P_Size <= Standard_Short_Integer_Size then
800 Lib_RE := RE_W_SI;
801 elsif P_Size <= Standard_Integer_Size then
802 Lib_RE := RE_W_I;
803 elsif P_Size <= Standard_Long_Integer_Size then
804 Lib_RE := RE_W_LI;
805 else
806 Lib_RE := RE_W_LLI;
807 end if;
808
809 -- Unsigned integer types, also includes unsigned fixed-point types
810 -- and unsigned enumeration types (note we know they are unsigned
811 -- because we already tested for signed above).
812
813 -- Also includes signed integer types that are unsigned in the sense
814 -- that they do not include negative numbers. See above for details.
815
816 elsif Is_Modular_Integer_Type (U_Type)
817 or else Is_Fixed_Point_Type (U_Type)
818 or else Is_Enumeration_Type (U_Type)
819 or else Is_Signed_Integer_Type (U_Type)
820 then
821 if P_Size <= Standard_Short_Short_Integer_Size then
822 Lib_RE := RE_W_SSU;
823 elsif P_Size <= Standard_Short_Integer_Size then
824 Lib_RE := RE_W_SU;
825 elsif P_Size <= Standard_Integer_Size then
826 Lib_RE := RE_W_U;
827 elsif P_Size <= Standard_Long_Integer_Size then
828 Lib_RE := RE_W_LU;
829 else
830 Lib_RE := RE_W_LLU;
831 end if;
832
833 else pragma Assert (Is_Access_Type (U_Type));
834
835 if P_Size > System_Address_Size then
836 Lib_RE := RE_W_AD;
837 else
838 Lib_RE := RE_W_AS;
839 end if;
840 end if;
841
842 -- Unchecked-convert parameter to the required type (i.e. the type of
843 -- the corresponding parameter, and call the appropriate routine.
844
845 Libent := RTE (Lib_RE);
846
847 return
848 Make_Procedure_Call_Statement (Loc,
849 Name => New_Occurrence_Of (Libent, Loc),
850 Parameter_Associations => New_List (
851 Relocate_Node (Strm),
852 Unchecked_Convert_To (Etype (Next_Formal (First_Formal (Libent))),
853 Relocate_Node (Item))));
854 end Build_Elementary_Write_Call;
855
856 -----------------------------------------
857 -- Build_Mutable_Record_Read_Procedure --
858 -----------------------------------------
859
860 procedure Build_Mutable_Record_Read_Procedure
861 (Loc : Source_Ptr;
862 Typ : Entity_Id;
863 Decl : out Node_Id;
864 Pnam : out Entity_Id)
865 is
866 Out_Formal : Node_Id;
867 -- Expression denoting the out formal parameter
868
869 Dcls : constant List_Id := New_List;
870 -- Declarations for the 'Read body
871
872 Stms : constant List_Id := New_List;
873 -- Statements for the 'Read body
874
875 Disc : Entity_Id;
876 -- Entity of the discriminant being processed
877
878 Tmp_For_Disc : Entity_Id;
879 -- Temporary object used to read the value of Disc
880
881 Tmps_For_Discs : constant List_Id := New_List;
882 -- List of object declarations for temporaries holding the read values
883 -- for the discriminants.
884
885 Cstr : constant List_Id := New_List;
886 -- List of constraints to be applied on temporary record
887
888 Discriminant_Checks : constant List_Id := New_List;
889 -- List of discriminant checks to be performed if the actual object
890 -- is constrained.
891
892 Tmp : constant Entity_Id := Make_Defining_Identifier (Loc, Name_V);
893 -- Temporary record must hide formal (assignments to components of the
894 -- record are always generated with V as the identifier for the record).
895
896 Constrained_Stms : List_Id := New_List;
897 -- Statements within the block where we have the constrained temporary
898
899 begin
900 -- A mutable type cannot be a tagged type, so we generate a new name
901 -- for the stream procedure.
902
903 Pnam :=
904 Make_Defining_Identifier (Loc,
905 Chars => Make_TSS_Name_Local (Typ, TSS_Stream_Read));
906
907 if Is_Unchecked_Union (Typ) then
908
909 -- If this is an unchecked union, the stream procedure is erroneous,
910 -- because there are no discriminants to read.
911
912 -- This should generate a warning ???
913
914 Append_To (Stms,
915 Make_Raise_Program_Error (Loc,
916 Reason => PE_Unchecked_Union_Restriction));
917
918 Build_Stream_Procedure (Loc, Typ, Decl, Pnam, Stms, Outp => True);
919 return;
920 end if;
921
922 Disc := First_Discriminant (Typ);
923
924 Out_Formal :=
925 Make_Selected_Component (Loc,
926 Prefix => New_Occurrence_Of (Pnam, Loc),
927 Selector_Name => Make_Identifier (Loc, Name_V));
928
929 -- Generate Reads for the discriminants of the type. The discriminants
930 -- need to be read before the rest of the components, so that variants
931 -- are initialized correctly. The discriminants must be read into temp
932 -- variables so an incomplete Read (interrupted by an exception, for
933 -- example) does not alter the passed object.
934
935 while Present (Disc) loop
936 Tmp_For_Disc := Make_Defining_Identifier (Loc,
937 New_External_Name (Chars (Disc), "D"));
938
939 Append_To (Tmps_For_Discs,
940 Make_Object_Declaration (Loc,
941 Defining_Identifier => Tmp_For_Disc,
942 Object_Definition => New_Occurrence_Of (Etype (Disc), Loc)));
943 Set_No_Initialization (Last (Tmps_For_Discs));
944
945 Append_To (Stms,
946 Make_Attribute_Reference (Loc,
947 Prefix => New_Occurrence_Of (Etype (Disc), Loc),
948 Attribute_Name => Name_Read,
949 Expressions => New_List (
950 Make_Identifier (Loc, Name_S),
951 New_Occurrence_Of (Tmp_For_Disc, Loc))));
952
953 Append_To (Cstr,
954 Make_Discriminant_Association (Loc,
955 Selector_Names => New_List (New_Occurrence_Of (Disc, Loc)),
956 Expression => New_Occurrence_Of (Tmp_For_Disc, Loc)));
957
958 Append_To (Discriminant_Checks,
959 Make_Raise_Constraint_Error (Loc,
960 Condition =>
961 Make_Op_Ne (Loc,
962 Left_Opnd => New_Occurrence_Of (Tmp_For_Disc, Loc),
963 Right_Opnd =>
964 Make_Selected_Component (Loc,
965 Prefix => New_Copy_Tree (Out_Formal),
966 Selector_Name => New_Occurrence_Of (Disc, Loc))),
967 Reason => CE_Discriminant_Check_Failed));
968 Next_Discriminant (Disc);
969 end loop;
970
971 -- Generate reads for the components of the record (including those
972 -- that depend on discriminants).
973
974 Build_Record_Read_Write_Procedure (Loc, Typ, Decl, Pnam, Name_Read);
975
976 -- Save original statement sequence for component assignments, and
977 -- replace it with Stms.
978
979 Constrained_Stms := Statements (Handled_Statement_Sequence (Decl));
980 Set_Handled_Statement_Sequence (Decl,
981 Make_Handled_Sequence_Of_Statements (Loc,
982 Statements => Stms));
983
984 -- If Typ has controlled components (i.e. if it is classwide or
985 -- Has_Controlled), or components constrained using the discriminants
986 -- of Typ, then we need to ensure that all component assignments are
987 -- performed on an object that has been appropriately constrained
988 -- prior to being initialized. To this effect, we wrap the component
989 -- assignments in a block where V is a constrained temporary.
990
991 Append_To (Dcls,
992 Make_Object_Declaration (Loc,
993 Defining_Identifier => Tmp,
994 Object_Definition =>
995 Make_Subtype_Indication (Loc,
996 Subtype_Mark => New_Occurrence_Of (Base_Type (Typ), Loc),
997 Constraint =>
998 Make_Index_Or_Discriminant_Constraint (Loc,
999 Constraints => Cstr))));
1000
1001 -- AI05-023-1: Insert discriminant check prior to initialization of the
1002 -- constrained temporary.
1003
1004 Append_To (Stms,
1005 Make_Implicit_If_Statement (Pnam,
1006 Condition =>
1007 Make_Attribute_Reference (Loc,
1008 Prefix => New_Copy_Tree (Out_Formal),
1009 Attribute_Name => Name_Constrained),
1010 Then_Statements => Discriminant_Checks));
1011
1012 -- Now insert back original component assignments, wrapped in a block
1013 -- in which V is the constrained temporary.
1014
1015 Append_To (Stms,
1016 Make_Block_Statement (Loc,
1017 Declarations => Dcls,
1018 Handled_Statement_Sequence => Parent (Constrained_Stms)));
1019
1020 Append_To (Constrained_Stms,
1021 Make_Assignment_Statement (Loc,
1022 Name => Out_Formal,
1023 Expression => Make_Identifier (Loc, Name_V)));
1024
1025 Set_Declarations (Decl, Tmps_For_Discs);
1026 end Build_Mutable_Record_Read_Procedure;
1027
1028 ------------------------------------------
1029 -- Build_Mutable_Record_Write_Procedure --
1030 ------------------------------------------
1031
1032 procedure Build_Mutable_Record_Write_Procedure
1033 (Loc : Source_Ptr;
1034 Typ : Entity_Id;
1035 Decl : out Node_Id;
1036 Pnam : out Entity_Id)
1037 is
1038 Stms : List_Id;
1039 Disc : Entity_Id;
1040 D_Ref : Node_Id;
1041
1042 begin
1043 Stms := New_List;
1044 Disc := First_Discriminant (Typ);
1045
1046 -- Generate Writes for the discriminants of the type
1047 -- If the type is an unchecked union, use the default values of
1048 -- the discriminants, because they are not stored.
1049
1050 while Present (Disc) loop
1051 if Is_Unchecked_Union (Typ) then
1052 D_Ref :=
1053 New_Copy_Tree (Discriminant_Default_Value (Disc));
1054 else
1055 D_Ref :=
1056 Make_Selected_Component (Loc,
1057 Prefix => Make_Identifier (Loc, Name_V),
1058 Selector_Name => New_Occurrence_Of (Disc, Loc));
1059 end if;
1060
1061 Append_To (Stms,
1062 Make_Attribute_Reference (Loc,
1063 Prefix => New_Occurrence_Of (Etype (Disc), Loc),
1064 Attribute_Name => Name_Write,
1065 Expressions => New_List (
1066 Make_Identifier (Loc, Name_S),
1067 D_Ref)));
1068
1069 Next_Discriminant (Disc);
1070 end loop;
1071
1072 -- A mutable type cannot be a tagged type, so we generate a new name
1073 -- for the stream procedure.
1074
1075 Pnam :=
1076 Make_Defining_Identifier (Loc,
1077 Chars => Make_TSS_Name_Local (Typ, TSS_Stream_Write));
1078 Build_Record_Read_Write_Procedure (Loc, Typ, Decl, Pnam, Name_Write);
1079
1080 -- Write the discriminants before the rest of the components, so
1081 -- that discriminant values are properly set of variants, etc.
1082
1083 if Is_Non_Empty_List (
1084 Statements (Handled_Statement_Sequence (Decl)))
1085 then
1086 Insert_List_Before
1087 (First (Statements (Handled_Statement_Sequence (Decl))), Stms);
1088 else
1089 Set_Statements (Handled_Statement_Sequence (Decl), Stms);
1090 end if;
1091 end Build_Mutable_Record_Write_Procedure;
1092
1093 -----------------------------------------------
1094 -- Build_Record_Or_Elementary_Input_Function --
1095 -----------------------------------------------
1096
1097 -- The function we build looks like
1098
1099 -- function InputN (S : access RST) return Typ is
1100 -- C1 : constant Disc_Type_1;
1101 -- Discr_Type_1'Read (S, C1);
1102 -- C2 : constant Disc_Type_2;
1103 -- Discr_Type_2'Read (S, C2);
1104 -- ...
1105 -- Cn : constant Disc_Type_n;
1106 -- Discr_Type_n'Read (S, Cn);
1107 -- V : Typ (C1, C2, .. Cn)
1108
1109 -- begin
1110 -- Typ'Read (S, V);
1111 -- return V;
1112 -- end InputN
1113
1114 -- The discriminants are of course only present in the case of a record
1115 -- with discriminants. In the case of a record with no discriminants, or
1116 -- an elementary type, then no Cn constants are defined.
1117
1118 procedure Build_Record_Or_Elementary_Input_Function
1119 (Loc : Source_Ptr;
1120 Typ : Entity_Id;
1121 Decl : out Node_Id;
1122 Fnam : out Entity_Id;
1123 Use_Underlying : Boolean := True)
1124 is
1125 B_Typ : Entity_Id := Base_Type (Typ);
1126 Cn : Name_Id;
1127 Constr : List_Id;
1128 Decls : List_Id;
1129 Discr : Entity_Id;
1130 Discr_Elmt : Elmt_Id := No_Elmt;
1131 J : Pos;
1132 Obj_Decl : Node_Id;
1133 Odef : Node_Id;
1134 Stms : List_Id;
1135
1136 begin
1137 if Use_Underlying then
1138 B_Typ := Underlying_Type (B_Typ);
1139 end if;
1140
1141 Decls := New_List;
1142 Constr := New_List;
1143
1144 J := 1;
1145
1146 -- In the presence of multiple instantiations (as in uses of the Booch
1147 -- components) the base type may be private, and the underlying type
1148 -- already constrained, in which case there's no discriminant constraint
1149 -- to construct.
1150
1151 if Has_Discriminants (Typ)
1152 and then No (Discriminant_Default_Value (First_Discriminant (Typ)))
1153 and then not Is_Constrained (Underlying_Type (B_Typ))
1154 then
1155 Discr := First_Discriminant (B_Typ);
1156
1157 -- If the prefix subtype is constrained, then retrieve the first
1158 -- element of its constraint.
1159
1160 if Is_Constrained (Typ) then
1161 Discr_Elmt := First_Elmt (Discriminant_Constraint (Typ));
1162 end if;
1163
1164 while Present (Discr) loop
1165 Cn := New_External_Name ('C', J);
1166
1167 Decl :=
1168 Make_Object_Declaration (Loc,
1169 Defining_Identifier => Make_Defining_Identifier (Loc, Cn),
1170 Object_Definition =>
1171 New_Occurrence_Of (Etype (Discr), Loc));
1172
1173 -- If this is an access discriminant, do not perform default
1174 -- initialization. The discriminant is about to get its value
1175 -- from Read, and if the type is null excluding we do not want
1176 -- spurious warnings on an initial null value.
1177
1178 if Is_Access_Type (Etype (Discr)) then
1179 Set_No_Initialization (Decl);
1180 end if;
1181
1182 Append_To (Decls, Decl);
1183 Append_To (Decls,
1184 Make_Attribute_Reference (Loc,
1185 Prefix => New_Occurrence_Of (Etype (Discr), Loc),
1186 Attribute_Name => Name_Read,
1187 Expressions => New_List (
1188 Make_Identifier (Loc, Name_S),
1189 Make_Identifier (Loc, Cn))));
1190
1191 Append_To (Constr, Make_Identifier (Loc, Cn));
1192
1193 -- If the prefix subtype imposes a discriminant constraint, then
1194 -- check that each discriminant value equals the value read.
1195
1196 if Present (Discr_Elmt) then
1197 Append_To (Decls,
1198 Make_Raise_Constraint_Error (Loc,
1199 Condition => Make_Op_Ne (Loc,
1200 Left_Opnd =>
1201 New_Occurrence_Of
1202 (Defining_Identifier (Decl), Loc),
1203 Right_Opnd =>
1204 New_Copy_Tree (Node (Discr_Elmt))),
1205 Reason => CE_Discriminant_Check_Failed));
1206
1207 Next_Elmt (Discr_Elmt);
1208 end if;
1209
1210 Next_Discriminant (Discr);
1211 J := J + 1;
1212 end loop;
1213
1214 Odef :=
1215 Make_Subtype_Indication (Loc,
1216 Subtype_Mark => New_Occurrence_Of (B_Typ, Loc),
1217 Constraint =>
1218 Make_Index_Or_Discriminant_Constraint (Loc,
1219 Constraints => Constr));
1220
1221 -- If no discriminants, then just use the type with no constraint
1222
1223 else
1224 Odef := New_Occurrence_Of (B_Typ, Loc);
1225 end if;
1226
1227 -- Create an extended return statement encapsulating the result object
1228 -- and 'Read call, which is needed in general for proper handling of
1229 -- build-in-place results (such as when the result type is inherently
1230 -- limited).
1231
1232 Obj_Decl :=
1233 Make_Object_Declaration (Loc,
1234 Defining_Identifier => Make_Defining_Identifier (Loc, Name_V),
1235 Object_Definition => Odef);
1236
1237 -- If the type is an access type, do not perform default initialization.
1238 -- The object is about to get its value from Read, and if the type is
1239 -- null excluding we do not want spurious warnings on an initial null.
1240
1241 if Is_Access_Type (B_Typ) then
1242 Set_No_Initialization (Obj_Decl);
1243 end if;
1244
1245 Stms := New_List (
1246 Make_Extended_Return_Statement (Loc,
1247 Return_Object_Declarations => New_List (Obj_Decl),
1248 Handled_Statement_Sequence =>
1249 Make_Handled_Sequence_Of_Statements (Loc,
1250 Statements => New_List (
1251 Make_Attribute_Reference (Loc,
1252 Prefix => New_Occurrence_Of (B_Typ, Loc),
1253 Attribute_Name => Name_Read,
1254 Expressions => New_List (
1255 Make_Identifier (Loc, Name_S),
1256 Make_Identifier (Loc, Name_V)))))));
1257
1258 Fnam := Make_Stream_Subprogram_Name (Loc, B_Typ, TSS_Stream_Input);
1259
1260 Build_Stream_Function (Loc, B_Typ, Decl, Fnam, Decls, Stms);
1261 end Build_Record_Or_Elementary_Input_Function;
1262
1263 -------------------------------------------------
1264 -- Build_Record_Or_Elementary_Output_Procedure --
1265 -------------------------------------------------
1266
1267 procedure Build_Record_Or_Elementary_Output_Procedure
1268 (Loc : Source_Ptr;
1269 Typ : Entity_Id;
1270 Decl : out Node_Id;
1271 Pnam : out Entity_Id)
1272 is
1273 Stms : List_Id;
1274 Disc : Entity_Id;
1275 Disc_Ref : Node_Id;
1276
1277 begin
1278 Stms := New_List;
1279
1280 -- Note that of course there will be no discriminants for the elementary
1281 -- type case, so Has_Discriminants will be False. Note that the language
1282 -- rules do not allow writing the discriminants in the defaulted case,
1283 -- because those are written by 'Write.
1284
1285 if Has_Discriminants (Typ)
1286 and then No (Discriminant_Default_Value (First_Discriminant (Typ)))
1287 then
1288 Disc := First_Discriminant (Typ);
1289 while Present (Disc) loop
1290
1291 -- If the type is an unchecked union, it must have default
1292 -- discriminants (this is checked earlier), and those defaults
1293 -- are written out to the stream.
1294
1295 if Is_Unchecked_Union (Typ) then
1296 Disc_Ref := New_Copy_Tree (Discriminant_Default_Value (Disc));
1297
1298 else
1299 Disc_Ref :=
1300 Make_Selected_Component (Loc,
1301 Prefix => Make_Identifier (Loc, Name_V),
1302 Selector_Name => New_Occurrence_Of (Disc, Loc));
1303 end if;
1304
1305 Append_To (Stms,
1306 Make_Attribute_Reference (Loc,
1307 Prefix =>
1308 New_Occurrence_Of (Stream_Base_Type (Etype (Disc)), Loc),
1309 Attribute_Name => Name_Write,
1310 Expressions => New_List (
1311 Make_Identifier (Loc, Name_S),
1312 Disc_Ref)));
1313
1314 Next_Discriminant (Disc);
1315 end loop;
1316 end if;
1317
1318 Append_To (Stms,
1319 Make_Attribute_Reference (Loc,
1320 Prefix => New_Occurrence_Of (Typ, Loc),
1321 Attribute_Name => Name_Write,
1322 Expressions => New_List (
1323 Make_Identifier (Loc, Name_S),
1324 Make_Identifier (Loc, Name_V))));
1325
1326 Pnam := Make_Stream_Subprogram_Name (Loc, Typ, TSS_Stream_Output);
1327
1328 Build_Stream_Procedure (Loc, Typ, Decl, Pnam, Stms, False);
1329 end Build_Record_Or_Elementary_Output_Procedure;
1330
1331 ---------------------------------
1332 -- Build_Record_Read_Procedure --
1333 ---------------------------------
1334
1335 procedure Build_Record_Read_Procedure
1336 (Loc : Source_Ptr;
1337 Typ : Entity_Id;
1338 Decl : out Node_Id;
1339 Pnam : out Entity_Id)
1340 is
1341 begin
1342 Pnam := Make_Stream_Subprogram_Name (Loc, Typ, TSS_Stream_Read);
1343 Build_Record_Read_Write_Procedure (Loc, Typ, Decl, Pnam, Name_Read);
1344 end Build_Record_Read_Procedure;
1345
1346 ---------------------------------------
1347 -- Build_Record_Read_Write_Procedure --
1348 ---------------------------------------
1349
1350 -- The form of the record read/write procedure is as shown by the
1351 -- following example for a case with one discriminant case variant:
1352
1353 -- procedure pnam (S : access RST, V : [out] Typ) is
1354 -- begin
1355 -- Component_Type'Read/Write (S, V.component);
1356 -- Component_Type'Read/Write (S, V.component);
1357 -- ...
1358 -- Component_Type'Read/Write (S, V.component);
1359 --
1360 -- case V.discriminant is
1361 -- when choices =>
1362 -- Component_Type'Read/Write (S, V.component);
1363 -- Component_Type'Read/Write (S, V.component);
1364 -- ...
1365 -- Component_Type'Read/Write (S, V.component);
1366 --
1367 -- when choices =>
1368 -- Component_Type'Read/Write (S, V.component);
1369 -- Component_Type'Read/Write (S, V.component);
1370 -- ...
1371 -- Component_Type'Read/Write (S, V.component);
1372 -- ...
1373 -- end case;
1374 -- end pnam;
1375
1376 -- The out keyword for V is supplied in the Read case
1377
1378 procedure Build_Record_Read_Write_Procedure
1379 (Loc : Source_Ptr;
1380 Typ : Entity_Id;
1381 Decl : out Node_Id;
1382 Pnam : Entity_Id;
1383 Nam : Name_Id)
1384 is
1385 Rdef : Node_Id;
1386 Stms : List_Id;
1387 Typt : Entity_Id;
1388
1389 In_Limited_Extension : Boolean := False;
1390 -- Set to True while processing the record extension definition
1391 -- for an extension of a limited type (for which an ancestor type
1392 -- has an explicit Nam attribute definition).
1393
1394 function Make_Component_List_Attributes (CL : Node_Id) return List_Id;
1395 -- Returns a sequence of attributes to process the components that
1396 -- are referenced in the given component list.
1397
1398 function Make_Field_Attribute (C : Entity_Id) return Node_Id;
1399 -- Given C, the entity for a discriminant or component, build
1400 -- an attribute for the corresponding field values.
1401
1402 function Make_Field_Attributes (Clist : List_Id) return List_Id;
1403 -- Given Clist, a component items list, construct series of attributes
1404 -- for fieldwise processing of the corresponding components.
1405
1406 ------------------------------------
1407 -- Make_Component_List_Attributes --
1408 ------------------------------------
1409
1410 function Make_Component_List_Attributes (CL : Node_Id) return List_Id is
1411 CI : constant List_Id := Component_Items (CL);
1412 VP : constant Node_Id := Variant_Part (CL);
1413
1414 Result : List_Id;
1415 Alts : List_Id;
1416 V : Node_Id;
1417 DC : Node_Id;
1418 DCH : List_Id;
1419 D_Ref : Node_Id;
1420
1421 begin
1422 Result := Make_Field_Attributes (CI);
1423
1424 if Present (VP) then
1425 Alts := New_List;
1426
1427 V := First_Non_Pragma (Variants (VP));
1428 while Present (V) loop
1429 DCH := New_List;
1430
1431 DC := First (Discrete_Choices (V));
1432 while Present (DC) loop
1433 Append_To (DCH, New_Copy_Tree (DC));
1434 Next (DC);
1435 end loop;
1436
1437 Append_To (Alts,
1438 Make_Case_Statement_Alternative (Loc,
1439 Discrete_Choices => DCH,
1440 Statements =>
1441 Make_Component_List_Attributes (Component_List (V))));
1442 Next_Non_Pragma (V);
1443 end loop;
1444
1445 -- Note: in the following, we make sure that we use new occurrence
1446 -- of for the selector, since there are cases in which we make a
1447 -- reference to a hidden discriminant that is not visible.
1448
1449 -- If the enclosing record is an unchecked_union, we use the
1450 -- default expressions for the discriminant (it must exist)
1451 -- because we cannot generate a reference to it, given that
1452 -- it is not stored.
1453
1454 if Is_Unchecked_Union (Scope (Entity (Name (VP)))) then
1455 D_Ref :=
1456 New_Copy_Tree
1457 (Discriminant_Default_Value (Entity (Name (VP))));
1458 else
1459 D_Ref :=
1460 Make_Selected_Component (Loc,
1461 Prefix => Make_Identifier (Loc, Name_V),
1462 Selector_Name =>
1463 New_Occurrence_Of (Entity (Name (VP)), Loc));
1464 end if;
1465
1466 Append_To (Result,
1467 Make_Case_Statement (Loc,
1468 Expression => D_Ref,
1469 Alternatives => Alts));
1470 end if;
1471
1472 return Result;
1473 end Make_Component_List_Attributes;
1474
1475 --------------------------
1476 -- Make_Field_Attribute --
1477 --------------------------
1478
1479 function Make_Field_Attribute (C : Entity_Id) return Node_Id is
1480 Field_Typ : constant Entity_Id := Stream_Base_Type (Etype (C));
1481
1482 TSS_Names : constant array (Name_Input .. Name_Write) of
1483 TSS_Name_Type :=
1484 (Name_Read => TSS_Stream_Read,
1485 Name_Write => TSS_Stream_Write,
1486 Name_Input => TSS_Stream_Input,
1487 Name_Output => TSS_Stream_Output,
1488 others => TSS_Null);
1489 pragma Assert (TSS_Names (Nam) /= TSS_Null);
1490
1491 begin
1492 if In_Limited_Extension
1493 and then Is_Limited_Type (Field_Typ)
1494 and then No (Find_Inherited_TSS (Field_Typ, TSS_Names (Nam)))
1495 then
1496 -- The declaration is illegal per 13.13.2(9/1), and this is
1497 -- enforced in Exp_Ch3.Check_Stream_Attributes. Keep the caller
1498 -- happy by returning a null statement.
1499
1500 return Make_Null_Statement (Loc);
1501 end if;
1502
1503 return
1504 Make_Attribute_Reference (Loc,
1505 Prefix => New_Occurrence_Of (Field_Typ, Loc),
1506 Attribute_Name => Nam,
1507 Expressions => New_List (
1508 Make_Identifier (Loc, Name_S),
1509 Make_Selected_Component (Loc,
1510 Prefix => Make_Identifier (Loc, Name_V),
1511 Selector_Name => New_Occurrence_Of (C, Loc))));
1512 end Make_Field_Attribute;
1513
1514 ---------------------------
1515 -- Make_Field_Attributes --
1516 ---------------------------
1517
1518 function Make_Field_Attributes (Clist : List_Id) return List_Id is
1519 Item : Node_Id;
1520 Result : List_Id;
1521
1522 begin
1523 Result := New_List;
1524
1525 if Present (Clist) then
1526 Item := First (Clist);
1527
1528 -- Loop through components, skipping all internal components,
1529 -- which are not part of the value (e.g. _Tag), except that we
1530 -- don't skip the _Parent, since we do want to process that
1531 -- recursively. If _Parent is an interface type, being abstract
1532 -- with no components there is no need to handle it.
1533
1534 while Present (Item) loop
1535 if Nkind (Item) = N_Component_Declaration
1536 and then
1537 ((Chars (Defining_Identifier (Item)) = Name_uParent
1538 and then not Is_Interface
1539 (Etype (Defining_Identifier (Item))))
1540 or else
1541 not Is_Internal_Name (Chars (Defining_Identifier (Item))))
1542 then
1543 Append_To
1544 (Result,
1545 Make_Field_Attribute (Defining_Identifier (Item)));
1546 end if;
1547
1548 Next (Item);
1549 end loop;
1550 end if;
1551
1552 return Result;
1553 end Make_Field_Attributes;
1554
1555 -- Start of processing for Build_Record_Read_Write_Procedure
1556
1557 begin
1558 -- For the protected type case, use corresponding record
1559
1560 if Is_Protected_Type (Typ) then
1561 Typt := Corresponding_Record_Type (Typ);
1562 else
1563 Typt := Typ;
1564 end if;
1565
1566 -- Note that we do nothing with the discriminants, since Read and
1567 -- Write do not read or write the discriminant values. All handling
1568 -- of discriminants occurs in the Input and Output subprograms.
1569
1570 Rdef := Type_Definition
1571 (Declaration_Node (Base_Type (Underlying_Type (Typt))));
1572 Stms := Empty_List;
1573
1574 -- In record extension case, the fields we want, including the _Parent
1575 -- field representing the parent type, are to be found in the extension.
1576 -- Note that we will naturally process the _Parent field using the type
1577 -- of the parent, and hence its stream attributes, which is appropriate.
1578
1579 if Nkind (Rdef) = N_Derived_Type_Definition then
1580 Rdef := Record_Extension_Part (Rdef);
1581
1582 if Is_Limited_Type (Typt) then
1583 In_Limited_Extension := True;
1584 end if;
1585 end if;
1586
1587 if Present (Component_List (Rdef)) then
1588 Append_List_To (Stms,
1589 Make_Component_List_Attributes (Component_List (Rdef)));
1590 end if;
1591
1592 Build_Stream_Procedure
1593 (Loc, Typ, Decl, Pnam, Stms, Nam = Name_Read);
1594 end Build_Record_Read_Write_Procedure;
1595
1596 ----------------------------------
1597 -- Build_Record_Write_Procedure --
1598 ----------------------------------
1599
1600 procedure Build_Record_Write_Procedure
1601 (Loc : Source_Ptr;
1602 Typ : Entity_Id;
1603 Decl : out Node_Id;
1604 Pnam : out Entity_Id)
1605 is
1606 begin
1607 Pnam := Make_Stream_Subprogram_Name (Loc, Typ, TSS_Stream_Write);
1608 Build_Record_Read_Write_Procedure (Loc, Typ, Decl, Pnam, Name_Write);
1609 end Build_Record_Write_Procedure;
1610
1611 -------------------------------
1612 -- Build_Stream_Attr_Profile --
1613 -------------------------------
1614
1615 function Build_Stream_Attr_Profile
1616 (Loc : Source_Ptr;
1617 Typ : Entity_Id;
1618 Nam : TSS_Name_Type) return List_Id
1619 is
1620 Profile : List_Id;
1621
1622 begin
1623 -- (Ada 2005: AI-441): Set the null-excluding attribute because it has
1624 -- no semantic meaning in Ada 95 but it is a requirement in Ada 2005.
1625
1626 Profile := New_List (
1627 Make_Parameter_Specification (Loc,
1628 Defining_Identifier => Make_Defining_Identifier (Loc, Name_S),
1629 Parameter_Type =>
1630 Make_Access_Definition (Loc,
1631 Null_Exclusion_Present => True,
1632 Subtype_Mark => New_Occurrence_Of (
1633 Class_Wide_Type (RTE (RE_Root_Stream_Type)), Loc))));
1634
1635 if Nam /= TSS_Stream_Input then
1636 Append_To (Profile,
1637 Make_Parameter_Specification (Loc,
1638 Defining_Identifier => Make_Defining_Identifier (Loc, Name_V),
1639 Out_Present => (Nam = TSS_Stream_Read),
1640 Parameter_Type => New_Occurrence_Of (Typ, Loc)));
1641 end if;
1642
1643 return Profile;
1644 end Build_Stream_Attr_Profile;
1645
1646 ---------------------------
1647 -- Build_Stream_Function --
1648 ---------------------------
1649
1650 procedure Build_Stream_Function
1651 (Loc : Source_Ptr;
1652 Typ : Entity_Id;
1653 Decl : out Node_Id;
1654 Fnam : Entity_Id;
1655 Decls : List_Id;
1656 Stms : List_Id)
1657 is
1658 Spec : Node_Id;
1659
1660 begin
1661 -- Construct function specification
1662
1663 -- (Ada 2005: AI-441): Set the null-excluding attribute because it has
1664 -- no semantic meaning in Ada 95 but it is a requirement in Ada 2005.
1665
1666 Spec :=
1667 Make_Function_Specification (Loc,
1668 Defining_Unit_Name => Fnam,
1669
1670 Parameter_Specifications => New_List (
1671 Make_Parameter_Specification (Loc,
1672 Defining_Identifier => Make_Defining_Identifier (Loc, Name_S),
1673 Parameter_Type =>
1674 Make_Access_Definition (Loc,
1675 Null_Exclusion_Present => True,
1676 Subtype_Mark =>
1677 New_Occurrence_Of
1678 (Class_Wide_Type (RTE (RE_Root_Stream_Type)), Loc)))),
1679
1680 Result_Definition => New_Occurrence_Of (Typ, Loc));
1681
1682 Decl :=
1683 Make_Subprogram_Body (Loc,
1684 Specification => Spec,
1685 Declarations => Decls,
1686 Handled_Statement_Sequence =>
1687 Make_Handled_Sequence_Of_Statements (Loc,
1688 Statements => Stms));
1689 end Build_Stream_Function;
1690
1691 ----------------------------
1692 -- Build_Stream_Procedure --
1693 ----------------------------
1694
1695 procedure Build_Stream_Procedure
1696 (Loc : Source_Ptr;
1697 Typ : Entity_Id;
1698 Decl : out Node_Id;
1699 Pnam : Entity_Id;
1700 Stms : List_Id;
1701 Outp : Boolean)
1702 is
1703 Spec : Node_Id;
1704
1705 begin
1706 -- Construct procedure specification
1707
1708 -- (Ada 2005: AI-441): Set the null-excluding attribute because it has
1709 -- no semantic meaning in Ada 95 but it is a requirement in Ada 2005.
1710
1711 Spec :=
1712 Make_Procedure_Specification (Loc,
1713 Defining_Unit_Name => Pnam,
1714
1715 Parameter_Specifications => New_List (
1716 Make_Parameter_Specification (Loc,
1717 Defining_Identifier => Make_Defining_Identifier (Loc, Name_S),
1718 Parameter_Type =>
1719 Make_Access_Definition (Loc,
1720 Null_Exclusion_Present => True,
1721 Subtype_Mark =>
1722 New_Occurrence_Of
1723 (Class_Wide_Type (RTE (RE_Root_Stream_Type)), Loc))),
1724
1725 Make_Parameter_Specification (Loc,
1726 Defining_Identifier => Make_Defining_Identifier (Loc, Name_V),
1727 Out_Present => Outp,
1728 Parameter_Type => New_Occurrence_Of (Typ, Loc))));
1729
1730 Decl :=
1731 Make_Subprogram_Body (Loc,
1732 Specification => Spec,
1733 Declarations => Empty_List,
1734 Handled_Statement_Sequence =>
1735 Make_Handled_Sequence_Of_Statements (Loc,
1736 Statements => Stms));
1737 end Build_Stream_Procedure;
1738
1739 -----------------------------
1740 -- Has_Stream_Standard_Rep --
1741 -----------------------------
1742
1743 function Has_Stream_Standard_Rep (U_Type : Entity_Id) return Boolean is
1744 Siz : Uint;
1745
1746 begin
1747 if Has_Non_Standard_Rep (U_Type) then
1748 return False;
1749 end if;
1750
1751 if Has_Stream_Size_Clause (U_Type) then
1752 Siz := Static_Integer (Expression (Stream_Size_Clause (U_Type)));
1753 else
1754 Siz := Esize (First_Subtype (U_Type));
1755 end if;
1756
1757 return Siz = Esize (Root_Type (U_Type));
1758 end Has_Stream_Standard_Rep;
1759
1760 ---------------------------------
1761 -- Make_Stream_Subprogram_Name --
1762 ---------------------------------
1763
1764 function Make_Stream_Subprogram_Name
1765 (Loc : Source_Ptr;
1766 Typ : Entity_Id;
1767 Nam : TSS_Name_Type) return Entity_Id
1768 is
1769 Sname : Name_Id;
1770
1771 begin
1772 -- For tagged types, we are dealing with a TSS associated with the
1773 -- declaration, so we use the standard primitive function name. For
1774 -- other types, generate a local TSS name since we are generating
1775 -- the subprogram at the point of use.
1776
1777 if Is_Tagged_Type (Typ) then
1778 Sname := Make_TSS_Name (Typ, Nam);
1779 else
1780 Sname := Make_TSS_Name_Local (Typ, Nam);
1781 end if;
1782
1783 return Make_Defining_Identifier (Loc, Sname);
1784 end Make_Stream_Subprogram_Name;
1785
1786 ----------------------
1787 -- Stream_Base_Type --
1788 ----------------------
1789
1790 function Stream_Base_Type (E : Entity_Id) return Entity_Id is
1791 begin
1792 if Is_Array_Type (E)
1793 and then Is_First_Subtype (E)
1794 then
1795 return E;
1796 else
1797 return Base_Type (E);
1798 end if;
1799 end Stream_Base_Type;
1800
1801 end Exp_Strm;
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