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