]> gcc.gnu.org Git - gcc.git/blob - gcc/cp/typeck2.c
re PR c++/42058 (Trouble with invalid array initialization)
[gcc.git] / gcc / cp / typeck2.c
1 /* Report error messages, build initializers, and perform
2 some front-end optimizations for C++ compiler.
3 Copyright (C) 1987, 1988, 1989, 1992, 1993, 1994, 1995, 1996, 1997, 1998,
4 1999, 2000, 2001, 2002, 2004, 2005, 2006, 2007, 2008, 2009
5 Free Software Foundation, Inc.
6 Hacked by Michael Tiemann (tiemann@cygnus.com)
7
8 This file is part of GCC.
9
10 GCC is free software; you can redistribute it and/or modify
11 it under the terms of the GNU General Public License as published by
12 the Free Software Foundation; either version 3, or (at your option)
13 any later version.
14
15 GCC is distributed in the hope that it will be useful,
16 but WITHOUT ANY WARRANTY; without even the implied warranty of
17 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
18 GNU General Public License for more details.
19
20 You should have received a copy of the GNU General Public License
21 along with GCC; see the file COPYING3. If not see
22 <http://www.gnu.org/licenses/>. */
23
24
25 /* This file is part of the C++ front end.
26 It contains routines to build C++ expressions given their operands,
27 including computing the types of the result, C and C++ specific error
28 checks, and some optimization. */
29
30 #include "config.h"
31 #include "system.h"
32 #include "coretypes.h"
33 #include "tm.h"
34 #include "tree.h"
35 #include "cp-tree.h"
36 #include "flags.h"
37 #include "toplev.h"
38 #include "output.h"
39 #include "diagnostic.h"
40 #include "real.h"
41
42 static tree
43 process_init_constructor (tree type, tree init);
44
45
46 /* Print an error message stemming from an attempt to use
47 BASETYPE as a base class for TYPE. */
48
49 tree
50 error_not_base_type (tree basetype, tree type)
51 {
52 if (TREE_CODE (basetype) == FUNCTION_DECL)
53 basetype = DECL_CONTEXT (basetype);
54 error ("type %qT is not a base type for type %qT", basetype, type);
55 return error_mark_node;
56 }
57
58 tree
59 binfo_or_else (tree base, tree type)
60 {
61 tree binfo = lookup_base (type, base, ba_unique, NULL);
62
63 if (binfo == error_mark_node)
64 return NULL_TREE;
65 else if (!binfo)
66 error_not_base_type (base, type);
67 return binfo;
68 }
69
70 /* According to ARM $7.1.6, "A `const' object may be initialized, but its
71 value may not be changed thereafter. */
72
73 void
74 readonly_error (tree arg, const char* string)
75 {
76 const char *fmt;
77
78 if (TREE_CODE (arg) == COMPONENT_REF)
79 {
80 if (TYPE_READONLY (TREE_TYPE (TREE_OPERAND (arg, 0))))
81 fmt = "%s of data-member %qD in read-only structure";
82 else
83 fmt = "%s of read-only data-member %qD";
84 error (fmt, string, TREE_OPERAND (arg, 1));
85 }
86 else if (TREE_CODE (arg) == VAR_DECL)
87 {
88 if (DECL_LANG_SPECIFIC (arg)
89 && DECL_IN_AGGR_P (arg)
90 && !TREE_STATIC (arg))
91 fmt = "%s of constant field %qD";
92 else
93 fmt = "%s of read-only variable %qD";
94 error (fmt, string, arg);
95 }
96 else if (TREE_CODE (arg) == PARM_DECL)
97 error ("%s of read-only parameter %qD", string, arg);
98 else if (TREE_CODE (arg) == INDIRECT_REF
99 && TREE_CODE (TREE_TYPE (TREE_OPERAND (arg, 0))) == REFERENCE_TYPE
100 && (TREE_CODE (TREE_OPERAND (arg, 0)) == VAR_DECL
101 || TREE_CODE (TREE_OPERAND (arg, 0)) == PARM_DECL))
102 error ("%s of read-only reference %qD", string, TREE_OPERAND (arg, 0));
103 else if (TREE_CODE (arg) == RESULT_DECL)
104 error ("%s of read-only named return value %qD", string, arg);
105 else if (TREE_CODE (arg) == FUNCTION_DECL)
106 error ("%s of function %qD", string, arg);
107 else
108 error ("%s of read-only location %qE", string, arg);
109 }
110
111 \f
112 /* Structure that holds information about declarations whose type was
113 incomplete and we could not check whether it was abstract or not. */
114
115 struct GTY((chain_next ("%h.next"))) pending_abstract_type {
116 /* Declaration which we are checking for abstractness. It is either
117 a DECL node, or an IDENTIFIER_NODE if we do not have a full
118 declaration available. */
119 tree decl;
120
121 /* Type which will be checked for abstractness. */
122 tree type;
123
124 /* Position of the declaration. This is only needed for IDENTIFIER_NODEs,
125 because DECLs already carry locus information. */
126 location_t locus;
127
128 /* Link to the next element in list. */
129 struct pending_abstract_type* next;
130 };
131
132
133 /* Compute the hash value of the node VAL. This function is used by the
134 hash table abstract_pending_vars. */
135
136 static hashval_t
137 pat_calc_hash (const void* val)
138 {
139 const struct pending_abstract_type *pat =
140 (const struct pending_abstract_type *) val;
141 return (hashval_t) TYPE_UID (pat->type);
142 }
143
144
145 /* Compare node VAL1 with the type VAL2. This function is used by the
146 hash table abstract_pending_vars. */
147
148 static int
149 pat_compare (const void* val1, const void* val2)
150 {
151 const struct pending_abstract_type *const pat1 =
152 (const struct pending_abstract_type *) val1;
153 const_tree const type2 = (const_tree)val2;
154
155 return (pat1->type == type2);
156 }
157
158 /* Hash table that maintains pending_abstract_type nodes, for which we still
159 need to check for type abstractness. The key of the table is the type
160 of the declaration. */
161 static GTY ((param_is (struct pending_abstract_type)))
162 htab_t abstract_pending_vars = NULL;
163
164
165 /* This function is called after TYPE is completed, and will check if there
166 are pending declarations for which we still need to verify the abstractness
167 of TYPE, and emit a diagnostic (through abstract_virtuals_error) if TYPE
168 turned out to be incomplete. */
169
170 void
171 complete_type_check_abstract (tree type)
172 {
173 void **slot;
174 struct pending_abstract_type *pat;
175 location_t cur_loc = input_location;
176
177 gcc_assert (COMPLETE_TYPE_P (type));
178
179 if (!abstract_pending_vars)
180 return;
181
182 /* Retrieve the list of pending declarations for this type. */
183 slot = htab_find_slot_with_hash (abstract_pending_vars, type,
184 (hashval_t)TYPE_UID (type), NO_INSERT);
185 if (!slot)
186 return;
187 pat = (struct pending_abstract_type*)*slot;
188 gcc_assert (pat);
189
190 /* If the type is not abstract, do not do anything. */
191 if (CLASSTYPE_PURE_VIRTUALS (type))
192 {
193 struct pending_abstract_type *prev = 0, *next;
194
195 /* Reverse the list to emit the errors in top-down order. */
196 for (; pat; pat = next)
197 {
198 next = pat->next;
199 pat->next = prev;
200 prev = pat;
201 }
202 pat = prev;
203
204 /* Go through the list, and call abstract_virtuals_error for each
205 element: it will issue a diagnostic if the type is abstract. */
206 while (pat)
207 {
208 gcc_assert (type == pat->type);
209
210 /* Tweak input_location so that the diagnostic appears at the correct
211 location. Notice that this is only needed if the decl is an
212 IDENTIFIER_NODE. */
213 input_location = pat->locus;
214 abstract_virtuals_error (pat->decl, pat->type);
215 pat = pat->next;
216 }
217 }
218
219 htab_clear_slot (abstract_pending_vars, slot);
220
221 input_location = cur_loc;
222 }
223
224
225 /* If TYPE has abstract virtual functions, issue an error about trying
226 to create an object of that type. DECL is the object declared, or
227 NULL_TREE if the declaration is unavailable. Returns 1 if an error
228 occurred; zero if all was well. */
229
230 int
231 abstract_virtuals_error (tree decl, tree type)
232 {
233 VEC(tree,gc) *pure;
234
235 /* This function applies only to classes. Any other entity can never
236 be abstract. */
237 if (!CLASS_TYPE_P (type))
238 return 0;
239
240 /* If the type is incomplete, we register it within a hash table,
241 so that we can check again once it is completed. This makes sense
242 only for objects for which we have a declaration or at least a
243 name. */
244 if (!COMPLETE_TYPE_P (type))
245 {
246 void **slot;
247 struct pending_abstract_type *pat;
248
249 gcc_assert (!decl || DECL_P (decl)
250 || TREE_CODE (decl) == IDENTIFIER_NODE);
251
252 if (!abstract_pending_vars)
253 abstract_pending_vars = htab_create_ggc (31, &pat_calc_hash,
254 &pat_compare, NULL);
255
256 slot = htab_find_slot_with_hash (abstract_pending_vars, type,
257 (hashval_t)TYPE_UID (type), INSERT);
258
259 pat = GGC_NEW (struct pending_abstract_type);
260 pat->type = type;
261 pat->decl = decl;
262 pat->locus = ((decl && DECL_P (decl))
263 ? DECL_SOURCE_LOCATION (decl)
264 : input_location);
265
266 pat->next = (struct pending_abstract_type *) *slot;
267 *slot = pat;
268
269 return 0;
270 }
271
272 if (!TYPE_SIZE (type))
273 /* TYPE is being defined, and during that time
274 CLASSTYPE_PURE_VIRTUALS holds the inline friends. */
275 return 0;
276
277 pure = CLASSTYPE_PURE_VIRTUALS (type);
278 if (!pure)
279 return 0;
280
281 if (decl)
282 {
283 if (TREE_CODE (decl) == RESULT_DECL)
284 return 0;
285
286 if (TREE_CODE (decl) == VAR_DECL)
287 error ("cannot declare variable %q+D to be of abstract "
288 "type %qT", decl, type);
289 else if (TREE_CODE (decl) == PARM_DECL)
290 error ("cannot declare parameter %q+D to be of abstract type %qT",
291 decl, type);
292 else if (TREE_CODE (decl) == FIELD_DECL)
293 error ("cannot declare field %q+D to be of abstract type %qT",
294 decl, type);
295 else if (TREE_CODE (decl) == FUNCTION_DECL
296 && TREE_CODE (TREE_TYPE (decl)) == METHOD_TYPE)
297 error ("invalid abstract return type for member function %q+#D", decl);
298 else if (TREE_CODE (decl) == FUNCTION_DECL)
299 error ("invalid abstract return type for function %q+#D", decl);
300 else if (TREE_CODE (decl) == IDENTIFIER_NODE)
301 /* Here we do not have location information. */
302 error ("invalid abstract type %qT for %qE", type, decl);
303 else
304 error ("invalid abstract type for %q+D", decl);
305 }
306 else
307 error ("cannot allocate an object of abstract type %qT", type);
308
309 /* Only go through this once. */
310 if (VEC_length (tree, pure))
311 {
312 unsigned ix;
313 tree fn;
314
315 inform (DECL_SOURCE_LOCATION (TYPE_MAIN_DECL (type)),
316 " because the following virtual functions are pure within %qT:",
317 type);
318
319 for (ix = 0; VEC_iterate (tree, pure, ix, fn); ix++)
320 inform (input_location, "\t%+#D", fn);
321 /* Now truncate the vector. This leaves it non-null, so we know
322 there are pure virtuals, but empty so we don't list them out
323 again. */
324 VEC_truncate (tree, pure, 0);
325 }
326 else
327 inform (DECL_SOURCE_LOCATION (TYPE_MAIN_DECL (type)),
328 " since type %qT has pure virtual functions",
329 type);
330
331 return 1;
332 }
333
334 /* Print an error message for invalid use of an incomplete type.
335 VALUE is the expression that was used (or 0 if that isn't known)
336 and TYPE is the type that was invalid. DIAG_KIND indicates the
337 type of diagnostic (see diagnostic.def). */
338
339 void
340 cxx_incomplete_type_diagnostic (const_tree value, const_tree type,
341 diagnostic_t diag_kind)
342 {
343 int decl = 0;
344
345 gcc_assert (diag_kind == DK_WARNING
346 || diag_kind == DK_PEDWARN
347 || diag_kind == DK_ERROR);
348
349 /* Avoid duplicate error message. */
350 if (TREE_CODE (type) == ERROR_MARK)
351 return;
352
353 if (value != 0 && (TREE_CODE (value) == VAR_DECL
354 || TREE_CODE (value) == PARM_DECL
355 || TREE_CODE (value) == FIELD_DECL))
356 {
357 emit_diagnostic (diag_kind, input_location, 0,
358 "%q+D has incomplete type", value);
359 decl = 1;
360 }
361 retry:
362 /* We must print an error message. Be clever about what it says. */
363
364 switch (TREE_CODE (type))
365 {
366 case RECORD_TYPE:
367 case UNION_TYPE:
368 case ENUMERAL_TYPE:
369 if (!decl)
370 emit_diagnostic (diag_kind, input_location, 0,
371 "invalid use of incomplete type %q#T", type);
372 if (!TYPE_TEMPLATE_INFO (type))
373 emit_diagnostic (diag_kind, input_location, 0,
374 "forward declaration of %q+#T", type);
375 else
376 emit_diagnostic (diag_kind, input_location, 0,
377 "declaration of %q+#T", type);
378 break;
379
380 case VOID_TYPE:
381 emit_diagnostic (diag_kind, input_location, 0,
382 "invalid use of %qT", type);
383 break;
384
385 case ARRAY_TYPE:
386 if (TYPE_DOMAIN (type))
387 {
388 type = TREE_TYPE (type);
389 goto retry;
390 }
391 emit_diagnostic (diag_kind, input_location, 0,
392 "invalid use of array with unspecified bounds");
393 break;
394
395 case OFFSET_TYPE:
396 bad_member:
397 emit_diagnostic (diag_kind, input_location, 0,
398 "invalid use of member (did you forget the %<&%> ?)");
399 break;
400
401 case TEMPLATE_TYPE_PARM:
402 if (is_auto (type))
403 emit_diagnostic (diag_kind, input_location, 0,
404 "invalid use of %<auto%>");
405 else
406 emit_diagnostic (diag_kind, input_location, 0,
407 "invalid use of template type parameter %qT", type);
408 break;
409
410 case BOUND_TEMPLATE_TEMPLATE_PARM:
411 emit_diagnostic (diag_kind, input_location, 0,
412 "invalid use of template template parameter %qT",
413 TYPE_NAME (type));
414 break;
415
416 case TYPENAME_TYPE:
417 emit_diagnostic (diag_kind, input_location, 0,
418 "invalid use of dependent type %qT", type);
419 break;
420
421 case UNKNOWN_TYPE:
422 if (value && TREE_CODE (value) == COMPONENT_REF)
423 goto bad_member;
424 else if (value && TREE_CODE (value) == ADDR_EXPR)
425 emit_diagnostic (diag_kind, input_location, 0,
426 "address of overloaded function with no contextual "
427 "type information");
428 else if (value && TREE_CODE (value) == OVERLOAD)
429 emit_diagnostic (diag_kind, input_location, 0,
430 "overloaded function with no contextual type information");
431 else
432 emit_diagnostic (diag_kind, input_location, 0,
433 "insufficient contextual information to determine type");
434 break;
435
436 default:
437 gcc_unreachable ();
438 }
439 }
440
441 /* Backward-compatibility interface to incomplete_type_diagnostic;
442 required by ../tree.c. */
443 #undef cxx_incomplete_type_error
444 void
445 cxx_incomplete_type_error (const_tree value, const_tree type)
446 {
447 cxx_incomplete_type_diagnostic (value, type, DK_ERROR);
448 }
449
450 \f
451 /* The recursive part of split_nonconstant_init. DEST is an lvalue
452 expression to which INIT should be assigned. INIT is a CONSTRUCTOR. */
453
454 static void
455 split_nonconstant_init_1 (tree dest, tree init)
456 {
457 unsigned HOST_WIDE_INT idx;
458 tree field_index, value;
459 tree type = TREE_TYPE (dest);
460 tree inner_type = NULL;
461 bool array_type_p = false;
462
463 switch (TREE_CODE (type))
464 {
465 case ARRAY_TYPE:
466 inner_type = TREE_TYPE (type);
467 array_type_p = true;
468 /* FALLTHRU */
469
470 case RECORD_TYPE:
471 case UNION_TYPE:
472 case QUAL_UNION_TYPE:
473 FOR_EACH_CONSTRUCTOR_ELT (CONSTRUCTOR_ELTS (init), idx,
474 field_index, value)
475 {
476 /* The current implementation of this algorithm assumes that
477 the field was set for all the elements. This is usually done
478 by process_init_constructor. */
479 gcc_assert (field_index);
480
481 if (!array_type_p)
482 inner_type = TREE_TYPE (field_index);
483
484 if (TREE_CODE (value) == CONSTRUCTOR)
485 {
486 tree sub;
487
488 if (array_type_p)
489 sub = build4 (ARRAY_REF, inner_type, dest, field_index,
490 NULL_TREE, NULL_TREE);
491 else
492 sub = build3 (COMPONENT_REF, inner_type, dest, field_index,
493 NULL_TREE);
494
495 split_nonconstant_init_1 (sub, value);
496 }
497 else if (!initializer_constant_valid_p (value, inner_type))
498 {
499 tree code;
500 tree sub;
501
502 /* FIXME: Ordered removal is O(1) so the whole function is
503 worst-case quadratic. This could be fixed using an aside
504 bitmap to record which elements must be removed and remove
505 them all at the same time. Or by merging
506 split_non_constant_init into process_init_constructor_array,
507 that is separating constants from non-constants while building
508 the vector. */
509 VEC_ordered_remove (constructor_elt, CONSTRUCTOR_ELTS (init),
510 idx);
511 --idx;
512
513 if (array_type_p)
514 sub = build4 (ARRAY_REF, inner_type, dest, field_index,
515 NULL_TREE, NULL_TREE);
516 else
517 sub = build3 (COMPONENT_REF, inner_type, dest, field_index,
518 NULL_TREE);
519
520 code = build2 (INIT_EXPR, inner_type, sub, value);
521 code = build_stmt (input_location, EXPR_STMT, code);
522 add_stmt (code);
523 continue;
524 }
525 }
526 break;
527
528 case VECTOR_TYPE:
529 if (!initializer_constant_valid_p (init, type))
530 {
531 tree code;
532 tree cons = copy_node (init);
533 CONSTRUCTOR_ELTS (init) = NULL;
534 code = build2 (MODIFY_EXPR, type, dest, cons);
535 code = build_stmt (input_location, EXPR_STMT, code);
536 add_stmt (code);
537 }
538 break;
539
540 default:
541 gcc_unreachable ();
542 }
543
544 /* The rest of the initializer is now a constant. */
545 TREE_CONSTANT (init) = 1;
546 }
547
548 /* A subroutine of store_init_value. Splits non-constant static
549 initializer INIT into a constant part and generates code to
550 perform the non-constant part of the initialization to DEST.
551 Returns the code for the runtime init. */
552
553 static tree
554 split_nonconstant_init (tree dest, tree init)
555 {
556 tree code;
557
558 if (TREE_CODE (init) == CONSTRUCTOR)
559 {
560 code = push_stmt_list ();
561 split_nonconstant_init_1 (dest, init);
562 code = pop_stmt_list (code);
563 DECL_INITIAL (dest) = init;
564 TREE_READONLY (dest) = 0;
565 }
566 else
567 code = build2 (INIT_EXPR, TREE_TYPE (dest), dest, init);
568
569 return code;
570 }
571
572 /* Perform appropriate conversions on the initial value of a variable,
573 store it in the declaration DECL,
574 and print any error messages that are appropriate.
575 If the init is invalid, store an ERROR_MARK.
576
577 C++: Note that INIT might be a TREE_LIST, which would mean that it is
578 a base class initializer for some aggregate type, hopefully compatible
579 with DECL. If INIT is a single element, and DECL is an aggregate
580 type, we silently convert INIT into a TREE_LIST, allowing a constructor
581 to be called.
582
583 If INIT is a TREE_LIST and there is no constructor, turn INIT
584 into a CONSTRUCTOR and use standard initialization techniques.
585 Perhaps a warning should be generated?
586
587 Returns code to be executed if initialization could not be performed
588 for static variable. In that case, caller must emit the code. */
589
590 tree
591 store_init_value (tree decl, tree init, int flags)
592 {
593 tree value, type;
594
595 /* If variable's type was invalidly declared, just ignore it. */
596
597 type = TREE_TYPE (decl);
598 if (TREE_CODE (type) == ERROR_MARK)
599 return NULL_TREE;
600
601 if (MAYBE_CLASS_TYPE_P (type))
602 {
603 gcc_assert (TYPE_HAS_TRIVIAL_INIT_REF (type)
604 || TREE_CODE (init) == CONSTRUCTOR);
605
606 if (TREE_CODE (init) == TREE_LIST)
607 {
608 error ("constructor syntax used, but no constructor declared "
609 "for type %qT", type);
610 init = build_constructor_from_list (init_list_type_node, nreverse (init));
611 }
612 }
613 else if (TREE_CODE (init) == TREE_LIST
614 && TREE_TYPE (init) != unknown_type_node)
615 {
616 if (TREE_CODE (decl) == RESULT_DECL)
617 init = build_x_compound_expr_from_list (init,
618 "return value initializer");
619 else if (TREE_CODE (init) == TREE_LIST
620 && TREE_CODE (TREE_TYPE (decl)) == ARRAY_TYPE)
621 {
622 error ("cannot initialize arrays using this syntax");
623 return NULL_TREE;
624 }
625 else
626 /* We get here with code like `int a (2);' */
627 init = build_x_compound_expr_from_list (init, "initializer");
628 }
629
630 /* End of special C++ code. */
631
632 /* Digest the specified initializer into an expression. */
633 value = digest_init_flags (type, init, flags);
634 /* If the initializer is not a constant, fill in DECL_INITIAL with
635 the bits that are constant, and then return an expression that
636 will perform the dynamic initialization. */
637 if (value != error_mark_node
638 && (TREE_SIDE_EFFECTS (value)
639 || ! initializer_constant_valid_p (value, TREE_TYPE (value))))
640 return split_nonconstant_init (decl, value);
641 /* If the value is a constant, just put it in DECL_INITIAL. If DECL
642 is an automatic variable, the middle end will turn this into a
643 dynamic initialization later. */
644 DECL_INITIAL (decl) = value;
645 return NULL_TREE;
646 }
647
648 \f
649 /* Give errors about narrowing conversions within { }. */
650
651 void
652 check_narrowing (tree type, tree init)
653 {
654 tree ftype = unlowered_expr_type (init);
655 bool ok = true;
656 REAL_VALUE_TYPE d;
657 bool was_decl = false;
658
659 if (DECL_P (init))
660 {
661 was_decl = true;
662 init = decl_constant_value (init);
663 }
664
665 if (TREE_CODE (type) == INTEGER_TYPE
666 && TREE_CODE (ftype) == REAL_TYPE)
667 ok = false;
668 else if (INTEGRAL_OR_ENUMERATION_TYPE_P (ftype)
669 && CP_INTEGRAL_TYPE_P (type))
670 {
671 if (TYPE_PRECISION (type) < TYPE_PRECISION (ftype)
672 && (TREE_CODE (init) != INTEGER_CST
673 || !int_fits_type_p (init, type)))
674 ok = false;
675 }
676 else if (TREE_CODE (ftype) == REAL_TYPE
677 && TREE_CODE (type) == REAL_TYPE)
678 {
679 if (TYPE_PRECISION (type) < TYPE_PRECISION (ftype))
680 {
681 if (TREE_CODE (init) == REAL_CST)
682 {
683 /* Issue 703: Loss of precision is OK as long as the value is
684 within the representable range of the new type. */
685 REAL_VALUE_TYPE r;
686 d = TREE_REAL_CST (init);
687 real_convert (&r, TYPE_MODE (type), &d);
688 if (real_isinf (&r))
689 ok = false;
690 }
691 else
692 ok = false;
693 }
694 }
695 else if (INTEGRAL_OR_ENUMERATION_TYPE_P (ftype)
696 && TREE_CODE (type) == REAL_TYPE)
697 {
698 ok = false;
699 if (TREE_CODE (init) == INTEGER_CST)
700 {
701 d = real_value_from_int_cst (0, init);
702 if (exact_real_truncate (TYPE_MODE (type), &d))
703 ok = true;
704 }
705 }
706
707 if (!ok)
708 permerror (input_location, "narrowing conversion of %qE from %qT to %qT inside { }",
709 init, ftype, type);
710 }
711
712 /* Process the initializer INIT for a variable of type TYPE, emitting
713 diagnostics for invalid initializers and converting the initializer as
714 appropriate.
715
716 For aggregate types, it assumes that reshape_init has already run, thus the
717 initializer will have the right shape (brace elision has been undone).
718
719 NESTED is true iff we are being called for an element of a CONSTRUCTOR. */
720
721 static tree
722 digest_init_r (tree type, tree init, bool nested, int flags)
723 {
724 enum tree_code code = TREE_CODE (type);
725
726 if (error_operand_p (init))
727 return error_mark_node;
728
729 gcc_assert (init);
730
731 /* We must strip the outermost array type when completing the type,
732 because the its bounds might be incomplete at the moment. */
733 if (!complete_type_or_else (TREE_CODE (type) == ARRAY_TYPE
734 ? TREE_TYPE (type) : type, NULL_TREE))
735 return error_mark_node;
736
737 /* Strip NON_LVALUE_EXPRs since we aren't using as an lvalue
738 (g++.old-deja/g++.law/casts2.C). */
739 if (TREE_CODE (init) == NON_LVALUE_EXPR)
740 init = TREE_OPERAND (init, 0);
741
742 /* Initialization of an array of chars from a string constant. The initializer
743 can be optionally enclosed in braces, but reshape_init has already removed
744 them if they were present. */
745 if (code == ARRAY_TYPE)
746 {
747 tree typ1 = TYPE_MAIN_VARIANT (TREE_TYPE (type));
748 if (char_type_p (typ1)
749 /*&& init */
750 && TREE_CODE (init) == STRING_CST)
751 {
752 tree char_type = TYPE_MAIN_VARIANT (TREE_TYPE (TREE_TYPE (init)));
753
754 if (TYPE_PRECISION (typ1) == BITS_PER_UNIT)
755 {
756 if (char_type != char_type_node)
757 {
758 error ("char-array initialized from wide string");
759 return error_mark_node;
760 }
761 }
762 else
763 {
764 if (char_type == char_type_node)
765 {
766 error ("int-array initialized from non-wide string");
767 return error_mark_node;
768 }
769 else if (char_type != typ1)
770 {
771 error ("int-array initialized from incompatible wide string");
772 return error_mark_node;
773 }
774 }
775
776 TREE_TYPE (init) = type;
777 if (TYPE_DOMAIN (type) != 0 && TREE_CONSTANT (TYPE_SIZE (type)))
778 {
779 int size = TREE_INT_CST_LOW (TYPE_SIZE (type));
780 size = (size + BITS_PER_UNIT - 1) / BITS_PER_UNIT;
781 /* In C it is ok to subtract 1 from the length of the string
782 because it's ok to ignore the terminating null char that is
783 counted in the length of the constant, but in C++ this would
784 be invalid. */
785 if (size < TREE_STRING_LENGTH (init))
786 permerror (input_location, "initializer-string for array of chars is too long");
787 }
788 return init;
789 }
790 }
791
792 /* Handle scalar types (including conversions) and references. */
793 if ((TREE_CODE (type) != COMPLEX_TYPE
794 || BRACE_ENCLOSED_INITIALIZER_P (init))
795 && (SCALAR_TYPE_P (type) || code == REFERENCE_TYPE))
796 {
797 tree *exp;
798
799 if (cxx_dialect != cxx98 && nested)
800 check_narrowing (type, init);
801 init = convert_for_initialization (0, type, init, flags,
802 "initialization", NULL_TREE, 0,
803 tf_warning_or_error);
804 exp = &init;
805
806 /* Skip any conversions since we'll be outputting the underlying
807 constant. */
808 while (CONVERT_EXPR_P (*exp)
809 || TREE_CODE (*exp) == NON_LVALUE_EXPR)
810 exp = &TREE_OPERAND (*exp, 0);
811
812 *exp = cplus_expand_constant (*exp);
813
814 return init;
815 }
816
817 /* Come here only for aggregates: records, arrays, unions, complex numbers
818 and vectors. */
819 gcc_assert (TREE_CODE (type) == ARRAY_TYPE
820 || TREE_CODE (type) == VECTOR_TYPE
821 || TREE_CODE (type) == RECORD_TYPE
822 || TREE_CODE (type) == UNION_TYPE
823 || TREE_CODE (type) == COMPLEX_TYPE);
824
825 if (BRACE_ENCLOSED_INITIALIZER_P (init)
826 && !TYPE_NON_AGGREGATE_CLASS (type))
827 return process_init_constructor (type, init);
828 else
829 {
830 if (COMPOUND_LITERAL_P (init) && TREE_CODE (type) == ARRAY_TYPE)
831 {
832 error ("cannot initialize aggregate of type %qT with "
833 "a compound literal", type);
834
835 return error_mark_node;
836 }
837
838 if (TREE_CODE (type) == ARRAY_TYPE
839 && TREE_CODE (init) != CONSTRUCTOR)
840 {
841 /* Allow the result of build_array_copy. */
842 if (TREE_CODE (init) == TARGET_EXPR
843 && (same_type_ignoring_top_level_qualifiers_p
844 (type, TREE_TYPE (init))))
845 return init;
846
847 error ("array must be initialized with a brace-enclosed"
848 " initializer");
849 return error_mark_node;
850 }
851
852 return convert_for_initialization (NULL_TREE, type, init,
853 flags,
854 "initialization", NULL_TREE, 0,
855 tf_warning_or_error);
856 }
857 }
858
859 tree
860 digest_init (tree type, tree init)
861 {
862 return digest_init_r (type, init, false, LOOKUP_IMPLICIT);
863 }
864
865 tree
866 digest_init_flags (tree type, tree init, int flags)
867 {
868 return digest_init_r (type, init, false, flags);
869 }
870 \f
871 /* Set of flags used within process_init_constructor to describe the
872 initializers. */
873 #define PICFLAG_ERRONEOUS 1
874 #define PICFLAG_NOT_ALL_CONSTANT 2
875 #define PICFLAG_NOT_ALL_SIMPLE 4
876
877 /* Given an initializer INIT, return the flag (PICFLAG_*) which better
878 describe it. */
879
880 static int
881 picflag_from_initializer (tree init)
882 {
883 if (init == error_mark_node)
884 return PICFLAG_ERRONEOUS;
885 else if (!TREE_CONSTANT (init))
886 return PICFLAG_NOT_ALL_CONSTANT;
887 else if (!initializer_constant_valid_p (init, TREE_TYPE (init)))
888 return PICFLAG_NOT_ALL_SIMPLE;
889 return 0;
890 }
891
892 /* Subroutine of process_init_constructor, which will process an initializer
893 INIT for an array or vector of type TYPE. Returns the flags (PICFLAG_*)
894 which describe the initializers. */
895
896 static int
897 process_init_constructor_array (tree type, tree init)
898 {
899 unsigned HOST_WIDE_INT i, len = 0;
900 int flags = 0;
901 bool unbounded = false;
902 constructor_elt *ce;
903 VEC(constructor_elt,gc) *v = CONSTRUCTOR_ELTS (init);
904
905 gcc_assert (TREE_CODE (type) == ARRAY_TYPE
906 || TREE_CODE (type) == VECTOR_TYPE);
907
908 if (TREE_CODE (type) == ARRAY_TYPE)
909 {
910 tree domain = TYPE_DOMAIN (type);
911 if (domain)
912 len = (TREE_INT_CST_LOW (TYPE_MAX_VALUE (domain))
913 - TREE_INT_CST_LOW (TYPE_MIN_VALUE (domain))
914 + 1);
915 else
916 unbounded = true; /* Take as many as there are. */
917 }
918 else
919 /* Vectors are like simple fixed-size arrays. */
920 len = TYPE_VECTOR_SUBPARTS (type);
921
922 /* There must not be more initializers than needed. */
923 if (!unbounded && VEC_length (constructor_elt, v) > len)
924 error ("too many initializers for %qT", type);
925
926 for (i = 0; VEC_iterate (constructor_elt, v, i, ce); ++i)
927 {
928 if (ce->index)
929 {
930 gcc_assert (TREE_CODE (ce->index) == INTEGER_CST);
931 if (compare_tree_int (ce->index, i) != 0)
932 {
933 ce->value = error_mark_node;
934 sorry ("non-trivial designated initializers not supported");
935 }
936 }
937 else
938 ce->index = size_int (i);
939 gcc_assert (ce->value);
940 ce->value = digest_init_r (TREE_TYPE (type), ce->value, true, LOOKUP_IMPLICIT);
941
942 if (ce->value != error_mark_node)
943 gcc_assert (same_type_ignoring_top_level_qualifiers_p
944 (TREE_TYPE (type), TREE_TYPE (ce->value)));
945
946 flags |= picflag_from_initializer (ce->value);
947 }
948
949 /* No more initializers. If the array is unbounded, we are done. Otherwise,
950 we must add initializers ourselves. */
951 if (!unbounded)
952 for (; i < len; ++i)
953 {
954 tree next;
955
956 if (TYPE_NEEDS_CONSTRUCTING (TREE_TYPE (type)))
957 {
958 /* If this type needs constructors run for default-initialization,
959 we can't rely on the back end to do it for us, so build up
960 TARGET_EXPRs. If the type in question is a class, just build
961 one up; if it's an array, recurse. */
962 if (MAYBE_CLASS_TYPE_P (TREE_TYPE (type)))
963 next = build_functional_cast (TREE_TYPE (type), NULL_TREE,
964 tf_warning_or_error);
965 else
966 next = build_constructor (init_list_type_node, NULL);
967 next = digest_init (TREE_TYPE (type), next);
968 }
969 else if (!zero_init_p (TREE_TYPE (type)))
970 next = build_zero_init (TREE_TYPE (type),
971 /*nelts=*/NULL_TREE,
972 /*static_storage_p=*/false);
973 else
974 /* The default zero-initialization is fine for us; don't
975 add anything to the CONSTRUCTOR. */
976 break;
977
978 flags |= picflag_from_initializer (next);
979 CONSTRUCTOR_APPEND_ELT (v, size_int (i), next);
980 }
981
982 CONSTRUCTOR_ELTS (init) = v;
983 return flags;
984 }
985
986 /* Subroutine of process_init_constructor, which will process an initializer
987 INIT for a class of type TYPE. Returns the flags (PICFLAG_*) which describe
988 the initializers. */
989
990 static int
991 process_init_constructor_record (tree type, tree init)
992 {
993 VEC(constructor_elt,gc) *v = NULL;
994 int flags = 0;
995 tree field;
996 unsigned HOST_WIDE_INT idx = 0;
997
998 gcc_assert (TREE_CODE (type) == RECORD_TYPE);
999 gcc_assert (!CLASSTYPE_VBASECLASSES (type));
1000 gcc_assert (!TYPE_BINFO (type)
1001 || !BINFO_N_BASE_BINFOS (TYPE_BINFO (type)));
1002 gcc_assert (!TYPE_POLYMORPHIC_P (type));
1003
1004 /* Generally, we will always have an index for each initializer (which is
1005 a FIELD_DECL, put by reshape_init), but compound literals don't go trough
1006 reshape_init. So we need to handle both cases. */
1007 for (field = TYPE_FIELDS (type); field; field = TREE_CHAIN (field))
1008 {
1009 tree next;
1010 tree type;
1011
1012 if (!DECL_NAME (field) && DECL_C_BIT_FIELD (field))
1013 {
1014 flags |= picflag_from_initializer (integer_zero_node);
1015 CONSTRUCTOR_APPEND_ELT (v, field, integer_zero_node);
1016 continue;
1017 }
1018
1019 if (TREE_CODE (field) != FIELD_DECL || DECL_ARTIFICIAL (field))
1020 continue;
1021
1022 /* If this is a bitfield, first convert to the declared type. */
1023 type = TREE_TYPE (field);
1024 if (DECL_BIT_FIELD_TYPE (field))
1025 type = DECL_BIT_FIELD_TYPE (field);
1026
1027 if (idx < VEC_length (constructor_elt, CONSTRUCTOR_ELTS (init)))
1028 {
1029 constructor_elt *ce = VEC_index (constructor_elt,
1030 CONSTRUCTOR_ELTS (init), idx);
1031 if (ce->index)
1032 {
1033 /* We can have either a FIELD_DECL or an IDENTIFIER_NODE. The
1034 latter case can happen in templates where lookup has to be
1035 deferred. */
1036 gcc_assert (TREE_CODE (ce->index) == FIELD_DECL
1037 || TREE_CODE (ce->index) == IDENTIFIER_NODE);
1038 if (ce->index != field
1039 && ce->index != DECL_NAME (field))
1040 {
1041 ce->value = error_mark_node;
1042 sorry ("non-trivial designated initializers not supported");
1043 }
1044 }
1045
1046 gcc_assert (ce->value);
1047 next = digest_init_r (type, ce->value, true, LOOKUP_IMPLICIT);
1048 ++idx;
1049 }
1050 else if (TYPE_NEEDS_CONSTRUCTING (TREE_TYPE (field)))
1051 {
1052 /* If this type needs constructors run for
1053 default-initialization, we can't rely on the back end to do it
1054 for us, so build up TARGET_EXPRs. If the type in question is
1055 a class, just build one up; if it's an array, recurse. */
1056 if (MAYBE_CLASS_TYPE_P (TREE_TYPE (field)))
1057 next = build_functional_cast (TREE_TYPE (field), NULL_TREE,
1058 tf_warning_or_error);
1059 else
1060 next = build_constructor (init_list_type_node, NULL);
1061
1062 next = digest_init_r (TREE_TYPE (field), next, true, LOOKUP_IMPLICIT);
1063
1064 /* Warn when some struct elements are implicitly initialized. */
1065 warning (OPT_Wmissing_field_initializers,
1066 "missing initializer for member %qD", field);
1067 }
1068 else
1069 {
1070 if (TREE_READONLY (field))
1071 error ("uninitialized const member %qD", field);
1072 else if (CLASSTYPE_READONLY_FIELDS_NEED_INIT (TREE_TYPE (field)))
1073 error ("member %qD with uninitialized const fields", field);
1074 else if (TREE_CODE (TREE_TYPE (field)) == REFERENCE_TYPE)
1075 error ("member %qD is uninitialized reference", field);
1076
1077 /* Warn when some struct elements are implicitly initialized
1078 to zero. */
1079 warning (OPT_Wmissing_field_initializers,
1080 "missing initializer for member %qD", field);
1081
1082 if (!zero_init_p (TREE_TYPE (field)))
1083 next = build_zero_init (TREE_TYPE (field), /*nelts=*/NULL_TREE,
1084 /*static_storage_p=*/false);
1085 else
1086 /* The default zero-initialization is fine for us; don't
1087 add anything to the CONSTRUCTOR. */
1088 continue;
1089 }
1090
1091 /* If this is a bitfield, now convert to the lowered type. */
1092 if (type != TREE_TYPE (field))
1093 next = cp_convert_and_check (TREE_TYPE (field), next);
1094 flags |= picflag_from_initializer (next);
1095 CONSTRUCTOR_APPEND_ELT (v, field, next);
1096 }
1097
1098 if (idx < VEC_length (constructor_elt, CONSTRUCTOR_ELTS (init)))
1099 error ("too many initializers for %qT", type);
1100
1101 CONSTRUCTOR_ELTS (init) = v;
1102 return flags;
1103 }
1104
1105 /* Subroutine of process_init_constructor, which will process a single
1106 initializer INIT for a union of type TYPE. Returns the flags (PICFLAG_*)
1107 which describe the initializer. */
1108
1109 static int
1110 process_init_constructor_union (tree type, tree init)
1111 {
1112 constructor_elt *ce;
1113 int len;
1114
1115 /* If the initializer was empty, use default zero initialization. */
1116 if (VEC_empty (constructor_elt, CONSTRUCTOR_ELTS (init)))
1117 return 0;
1118
1119 len = VEC_length (constructor_elt, CONSTRUCTOR_ELTS (init));
1120 if (len > 1)
1121 {
1122 error ("too many initializers for %qT", type);
1123 VEC_block_remove (constructor_elt, CONSTRUCTOR_ELTS (init), 1, len-1);
1124 }
1125
1126 ce = VEC_index (constructor_elt, CONSTRUCTOR_ELTS (init), 0);
1127
1128 /* If this element specifies a field, initialize via that field. */
1129 if (ce->index)
1130 {
1131 if (TREE_CODE (ce->index) == FIELD_DECL)
1132 ;
1133 else if (TREE_CODE (ce->index) == IDENTIFIER_NODE)
1134 {
1135 /* This can happen within a cast, see g++.dg/opt/cse2.C. */
1136 tree name = ce->index;
1137 tree field;
1138 for (field = TYPE_FIELDS (type); field; field = TREE_CHAIN (field))
1139 if (DECL_NAME (field) == name)
1140 break;
1141 if (!field)
1142 {
1143 error ("no field %qD found in union being initialized", field);
1144 ce->value = error_mark_node;
1145 }
1146 ce->index = field;
1147 }
1148 else
1149 {
1150 gcc_assert (TREE_CODE (ce->index) == INTEGER_CST
1151 || TREE_CODE (ce->index) == RANGE_EXPR);
1152 error ("index value instead of field name in union initializer");
1153 ce->value = error_mark_node;
1154 }
1155 }
1156 else
1157 {
1158 /* Find the first named field. ANSI decided in September 1990
1159 that only named fields count here. */
1160 tree field = TYPE_FIELDS (type);
1161 while (field && (!DECL_NAME (field) || TREE_CODE (field) != FIELD_DECL))
1162 field = TREE_CHAIN (field);
1163 if (field == NULL_TREE)
1164 {
1165 error ("too many initializers for %qT", type);
1166 ce->value = error_mark_node;
1167 }
1168 ce->index = field;
1169 }
1170
1171 if (ce->value && ce->value != error_mark_node)
1172 ce->value = digest_init_r (TREE_TYPE (ce->index), ce->value, true, LOOKUP_IMPLICIT);
1173
1174 return picflag_from_initializer (ce->value);
1175 }
1176
1177 /* Process INIT, a constructor for a variable of aggregate type TYPE. The
1178 constructor is a brace-enclosed initializer, and will be modified in-place.
1179
1180 Each element is converted to the right type through digest_init, and
1181 missing initializers are added following the language rules (zero-padding,
1182 etc.).
1183
1184 After the execution, the initializer will have TREE_CONSTANT if all elts are
1185 constant, and TREE_STATIC set if, in addition, all elts are simple enough
1186 constants that the assembler and linker can compute them.
1187
1188 The function returns the initializer itself, or error_mark_node in case
1189 of error. */
1190
1191 static tree
1192 process_init_constructor (tree type, tree init)
1193 {
1194 int flags;
1195
1196 gcc_assert (BRACE_ENCLOSED_INITIALIZER_P (init));
1197
1198 if (TREE_CODE (type) == ARRAY_TYPE || TREE_CODE (type) == VECTOR_TYPE)
1199 flags = process_init_constructor_array (type, init);
1200 else if (TREE_CODE (type) == RECORD_TYPE)
1201 flags = process_init_constructor_record (type, init);
1202 else if (TREE_CODE (type) == UNION_TYPE)
1203 flags = process_init_constructor_union (type, init);
1204 else
1205 gcc_unreachable ();
1206
1207 if (flags & PICFLAG_ERRONEOUS)
1208 return error_mark_node;
1209
1210 TREE_TYPE (init) = type;
1211 if (TREE_CODE (type) == ARRAY_TYPE && TYPE_DOMAIN (type) == NULL_TREE)
1212 cp_complete_array_type (&TREE_TYPE (init), init, /*do_default=*/0);
1213 if (!(flags & PICFLAG_NOT_ALL_CONSTANT))
1214 {
1215 TREE_CONSTANT (init) = 1;
1216 if (!(flags & PICFLAG_NOT_ALL_SIMPLE))
1217 TREE_STATIC (init) = 1;
1218 }
1219 return init;
1220 }
1221 \f
1222 /* Given a structure or union value DATUM, construct and return
1223 the structure or union component which results from narrowing
1224 that value to the base specified in BASETYPE. For example, given the
1225 hierarchy
1226
1227 class L { int ii; };
1228 class A : L { ... };
1229 class B : L { ... };
1230 class C : A, B { ... };
1231
1232 and the declaration
1233
1234 C x;
1235
1236 then the expression
1237
1238 x.A::ii refers to the ii member of the L part of
1239 the A part of the C object named by X. In this case,
1240 DATUM would be x, and BASETYPE would be A.
1241
1242 I used to think that this was nonconformant, that the standard specified
1243 that first we look up ii in A, then convert x to an L& and pull out the
1244 ii part. But in fact, it does say that we convert x to an A&; A here
1245 is known as the "naming class". (jason 2000-12-19)
1246
1247 BINFO_P points to a variable initialized either to NULL_TREE or to the
1248 binfo for the specific base subobject we want to convert to. */
1249
1250 tree
1251 build_scoped_ref (tree datum, tree basetype, tree* binfo_p)
1252 {
1253 tree binfo;
1254
1255 if (datum == error_mark_node)
1256 return error_mark_node;
1257 if (*binfo_p)
1258 binfo = *binfo_p;
1259 else
1260 binfo = lookup_base (TREE_TYPE (datum), basetype, ba_check, NULL);
1261
1262 if (!binfo || binfo == error_mark_node)
1263 {
1264 *binfo_p = NULL_TREE;
1265 if (!binfo)
1266 error_not_base_type (basetype, TREE_TYPE (datum));
1267 return error_mark_node;
1268 }
1269
1270 *binfo_p = binfo;
1271 return build_base_path (PLUS_EXPR, datum, binfo, 1);
1272 }
1273
1274 /* Build a reference to an object specified by the C++ `->' operator.
1275 Usually this just involves dereferencing the object, but if the
1276 `->' operator is overloaded, then such overloads must be
1277 performed until an object which does not have the `->' operator
1278 overloaded is found. An error is reported when circular pointer
1279 delegation is detected. */
1280
1281 tree
1282 build_x_arrow (tree expr)
1283 {
1284 tree orig_expr = expr;
1285 tree types_memoized = NULL_TREE;
1286 tree type = TREE_TYPE (expr);
1287 tree last_rval = NULL_TREE;
1288
1289 if (type == error_mark_node)
1290 return error_mark_node;
1291
1292 if (processing_template_decl)
1293 {
1294 if (type_dependent_expression_p (expr))
1295 return build_min_nt (ARROW_EXPR, expr);
1296 expr = build_non_dependent_expr (expr);
1297 }
1298
1299 if (MAYBE_CLASS_TYPE_P (type))
1300 {
1301 while ((expr = build_new_op (COMPONENT_REF, LOOKUP_NORMAL, expr,
1302 NULL_TREE, NULL_TREE,
1303 /*overloaded_p=*/NULL,
1304 tf_warning_or_error)))
1305 {
1306 if (expr == error_mark_node)
1307 return error_mark_node;
1308
1309 if (value_member (TREE_TYPE (expr), types_memoized))
1310 {
1311 error ("circular pointer delegation detected");
1312 return error_mark_node;
1313 }
1314 else
1315 {
1316 types_memoized = tree_cons (NULL_TREE, TREE_TYPE (expr),
1317 types_memoized);
1318 }
1319 last_rval = expr;
1320 }
1321
1322 if (last_rval == NULL_TREE)
1323 {
1324 error ("base operand of %<->%> has non-pointer type %qT", type);
1325 return error_mark_node;
1326 }
1327
1328 if (TREE_CODE (TREE_TYPE (last_rval)) == REFERENCE_TYPE)
1329 last_rval = convert_from_reference (last_rval);
1330 }
1331 else
1332 last_rval = decay_conversion (expr);
1333
1334 if (TREE_CODE (TREE_TYPE (last_rval)) == POINTER_TYPE)
1335 {
1336 if (processing_template_decl)
1337 {
1338 expr = build_min_non_dep (ARROW_EXPR, last_rval, orig_expr);
1339 /* It will be dereferenced. */
1340 TREE_TYPE (expr) = TREE_TYPE (TREE_TYPE (last_rval));
1341 return expr;
1342 }
1343
1344 return cp_build_indirect_ref (last_rval, NULL, tf_warning_or_error);
1345 }
1346
1347 if (types_memoized)
1348 error ("result of %<operator->()%> yields non-pointer result");
1349 else
1350 error ("base operand of %<->%> is not a pointer");
1351 return error_mark_node;
1352 }
1353
1354 /* Return an expression for "DATUM .* COMPONENT". DATUM has not
1355 already been checked out to be of aggregate type. */
1356
1357 tree
1358 build_m_component_ref (tree datum, tree component)
1359 {
1360 tree ptrmem_type;
1361 tree objtype;
1362 tree type;
1363 tree binfo;
1364 tree ctype;
1365
1366 if (error_operand_p (datum) || error_operand_p (component))
1367 return error_mark_node;
1368
1369 ptrmem_type = TREE_TYPE (component);
1370 if (!TYPE_PTR_TO_MEMBER_P (ptrmem_type))
1371 {
1372 error ("%qE cannot be used as a member pointer, since it is of "
1373 "type %qT",
1374 component, ptrmem_type);
1375 return error_mark_node;
1376 }
1377
1378 objtype = TYPE_MAIN_VARIANT (TREE_TYPE (datum));
1379 if (! MAYBE_CLASS_TYPE_P (objtype))
1380 {
1381 error ("cannot apply member pointer %qE to %qE, which is of "
1382 "non-class type %qT",
1383 component, datum, objtype);
1384 return error_mark_node;
1385 }
1386
1387 type = TYPE_PTRMEM_POINTED_TO_TYPE (ptrmem_type);
1388 ctype = complete_type (TYPE_PTRMEM_CLASS_TYPE (ptrmem_type));
1389
1390 if (!COMPLETE_TYPE_P (ctype))
1391 {
1392 if (!same_type_p (ctype, objtype))
1393 goto mismatch;
1394 binfo = NULL;
1395 }
1396 else
1397 {
1398 binfo = lookup_base (objtype, ctype, ba_check, NULL);
1399
1400 if (!binfo)
1401 {
1402 mismatch:
1403 error ("pointer to member type %qT incompatible with object "
1404 "type %qT",
1405 type, objtype);
1406 return error_mark_node;
1407 }
1408 else if (binfo == error_mark_node)
1409 return error_mark_node;
1410 }
1411
1412 if (TYPE_PTRMEM_P (ptrmem_type))
1413 {
1414 tree ptype;
1415
1416 /* Compute the type of the field, as described in [expr.ref].
1417 There's no such thing as a mutable pointer-to-member, so
1418 things are not as complex as they are for references to
1419 non-static data members. */
1420 type = cp_build_qualified_type (type,
1421 (cp_type_quals (type)
1422 | cp_type_quals (TREE_TYPE (datum))));
1423
1424 datum = build_address (datum);
1425
1426 /* Convert object to the correct base. */
1427 if (binfo)
1428 datum = build_base_path (PLUS_EXPR, datum, binfo, 1);
1429
1430 /* Build an expression for "object + offset" where offset is the
1431 value stored in the pointer-to-data-member. */
1432 ptype = build_pointer_type (type);
1433 datum = build2 (POINTER_PLUS_EXPR, ptype,
1434 fold_convert (ptype, datum),
1435 build_nop (sizetype, component));
1436 return cp_build_indirect_ref (datum, 0, tf_warning_or_error);
1437 }
1438 else
1439 return build2 (OFFSET_REF, type, datum, component);
1440 }
1441
1442 /* Return a tree node for the expression TYPENAME '(' PARMS ')'. */
1443
1444 tree
1445 build_functional_cast (tree exp, tree parms, tsubst_flags_t complain)
1446 {
1447 /* This is either a call to a constructor,
1448 or a C cast in C++'s `functional' notation. */
1449
1450 /* The type to which we are casting. */
1451 tree type;
1452 VEC(tree,gc) *parmvec;
1453
1454 if (exp == error_mark_node || parms == error_mark_node)
1455 return error_mark_node;
1456
1457 if (TREE_CODE (exp) == TYPE_DECL)
1458 type = TREE_TYPE (exp);
1459 else
1460 type = exp;
1461
1462 if (TREE_CODE (type) == REFERENCE_TYPE && !parms)
1463 {
1464 error ("invalid value-initialization of reference types");
1465 return error_mark_node;
1466 }
1467
1468 if (processing_template_decl)
1469 {
1470 tree t = build_min (CAST_EXPR, type, parms);
1471 /* We don't know if it will or will not have side effects. */
1472 TREE_SIDE_EFFECTS (t) = 1;
1473 return t;
1474 }
1475
1476 if (! MAYBE_CLASS_TYPE_P (type))
1477 {
1478 if (parms == NULL_TREE)
1479 return cp_convert (type, integer_zero_node);
1480
1481 /* This must build a C cast. */
1482 parms = build_x_compound_expr_from_list (parms, "functional cast");
1483 return cp_build_c_cast (type, parms, complain);
1484 }
1485
1486 /* Prepare to evaluate as a call to a constructor. If this expression
1487 is actually used, for example,
1488
1489 return X (arg1, arg2, ...);
1490
1491 then the slot being initialized will be filled in. */
1492
1493 if (!complete_type_or_else (type, NULL_TREE))
1494 return error_mark_node;
1495 if (abstract_virtuals_error (NULL_TREE, type))
1496 return error_mark_node;
1497
1498 /* [expr.type.conv]
1499
1500 If the expression list is a single-expression, the type
1501 conversion is equivalent (in definedness, and if defined in
1502 meaning) to the corresponding cast expression. */
1503 if (parms && TREE_CHAIN (parms) == NULL_TREE)
1504 return cp_build_c_cast (type, TREE_VALUE (parms), complain);
1505
1506 /* [expr.type.conv]
1507
1508 The expression T(), where T is a simple-type-specifier for a
1509 non-array complete object type or the (possibly cv-qualified)
1510 void type, creates an rvalue of the specified type, which is
1511 value-initialized. */
1512
1513 if (parms == NULL_TREE
1514 /* If there's a user-defined constructor, value-initialization is
1515 just calling the constructor, so fall through. */
1516 && !TYPE_HAS_USER_CONSTRUCTOR (type))
1517 {
1518 exp = build_value_init (type);
1519 return get_target_expr (exp);
1520 }
1521
1522 /* Call the constructor. */
1523 parmvec = make_tree_vector ();
1524 for (; parms != NULL_TREE; parms = TREE_CHAIN (parms))
1525 VEC_safe_push (tree, gc, parmvec, TREE_VALUE (parms));
1526 exp = build_special_member_call (NULL_TREE, complete_ctor_identifier,
1527 &parmvec, type, LOOKUP_NORMAL, complain);
1528 release_tree_vector (parmvec);
1529
1530 if (exp == error_mark_node)
1531 return error_mark_node;
1532
1533 return build_cplus_new (type, exp);
1534 }
1535 \f
1536
1537 /* Add new exception specifier SPEC, to the LIST we currently have.
1538 If it's already in LIST then do nothing.
1539 Moan if it's bad and we're allowed to. COMPLAIN < 0 means we
1540 know what we're doing. */
1541
1542 tree
1543 add_exception_specifier (tree list, tree spec, int complain)
1544 {
1545 bool ok;
1546 tree core = spec;
1547 bool is_ptr;
1548 diagnostic_t diag_type = DK_UNSPECIFIED; /* none */
1549
1550 if (spec == error_mark_node)
1551 return list;
1552
1553 gcc_assert (spec && (!list || TREE_VALUE (list)));
1554
1555 /* [except.spec] 1, type in an exception specifier shall not be
1556 incomplete, or pointer or ref to incomplete other than pointer
1557 to cv void. */
1558 is_ptr = TREE_CODE (core) == POINTER_TYPE;
1559 if (is_ptr || TREE_CODE (core) == REFERENCE_TYPE)
1560 core = TREE_TYPE (core);
1561 if (complain < 0)
1562 ok = true;
1563 else if (VOID_TYPE_P (core))
1564 ok = is_ptr;
1565 else if (TREE_CODE (core) == TEMPLATE_TYPE_PARM)
1566 ok = true;
1567 else if (processing_template_decl)
1568 ok = true;
1569 else
1570 {
1571 ok = true;
1572 /* 15.4/1 says that types in an exception specifier must be complete,
1573 but it seems more reasonable to only require this on definitions
1574 and calls. So just give a pedwarn at this point; we will give an
1575 error later if we hit one of those two cases. */
1576 if (!COMPLETE_TYPE_P (complete_type (core)))
1577 diag_type = DK_PEDWARN; /* pedwarn */
1578 }
1579
1580 if (ok)
1581 {
1582 tree probe;
1583
1584 for (probe = list; probe; probe = TREE_CHAIN (probe))
1585 if (same_type_p (TREE_VALUE (probe), spec))
1586 break;
1587 if (!probe)
1588 list = tree_cons (NULL_TREE, spec, list);
1589 }
1590 else
1591 diag_type = DK_ERROR; /* error */
1592
1593 if (diag_type != DK_UNSPECIFIED && complain)
1594 cxx_incomplete_type_diagnostic (NULL_TREE, core, diag_type);
1595
1596 return list;
1597 }
1598
1599 /* Combine the two exceptions specifier lists LIST and ADD, and return
1600 their union. */
1601
1602 tree
1603 merge_exception_specifiers (tree list, tree add)
1604 {
1605 if (!list || !add)
1606 return NULL_TREE;
1607 else if (!TREE_VALUE (list))
1608 return add;
1609 else if (!TREE_VALUE (add))
1610 return list;
1611 else
1612 {
1613 tree orig_list = list;
1614
1615 for (; add; add = TREE_CHAIN (add))
1616 {
1617 tree spec = TREE_VALUE (add);
1618 tree probe;
1619
1620 for (probe = orig_list; probe; probe = TREE_CHAIN (probe))
1621 if (same_type_p (TREE_VALUE (probe), spec))
1622 break;
1623 if (!probe)
1624 {
1625 spec = build_tree_list (NULL_TREE, spec);
1626 TREE_CHAIN (spec) = list;
1627 list = spec;
1628 }
1629 }
1630 }
1631 return list;
1632 }
1633
1634 /* Subroutine of build_call. Ensure that each of the types in the
1635 exception specification is complete. Technically, 15.4/1 says that
1636 they need to be complete when we see a declaration of the function,
1637 but we should be able to get away with only requiring this when the
1638 function is defined or called. See also add_exception_specifier. */
1639
1640 void
1641 require_complete_eh_spec_types (tree fntype, tree decl)
1642 {
1643 tree raises;
1644 /* Don't complain about calls to op new. */
1645 if (decl && DECL_ARTIFICIAL (decl))
1646 return;
1647 for (raises = TYPE_RAISES_EXCEPTIONS (fntype); raises;
1648 raises = TREE_CHAIN (raises))
1649 {
1650 tree type = TREE_VALUE (raises);
1651 if (type && !COMPLETE_TYPE_P (type))
1652 {
1653 if (decl)
1654 error
1655 ("call to function %qD which throws incomplete type %q#T",
1656 decl, type);
1657 else
1658 error ("call to function which throws incomplete type %q#T",
1659 decl);
1660 }
1661 }
1662 }
1663
1664 \f
1665 #include "gt-cp-typeck2.h"
This page took 0.110859 seconds and 6 git commands to generate.