re PR c++/48450 ([C++0x][SFINAE] Hard errors with static_cast expressions)
[gcc.git] / gcc / cp / typeck.c
1 /* Build expressions with type checking for C++ compiler.
2 Copyright (C) 1987, 1988, 1989, 1992, 1993, 1994, 1995, 1996, 1997, 1998,
3 1999, 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2010, 2011
4 Free Software Foundation, Inc.
5 Hacked by Michael Tiemann (tiemann@cygnus.com)
6
7 This file is part of GCC.
8
9 GCC is free software; you can redistribute it and/or modify
10 it under the terms of the GNU General Public License as published by
11 the Free Software Foundation; either version 3, or (at your option)
12 any later version.
13
14 GCC is distributed in the hope that it will be useful,
15 but WITHOUT ANY WARRANTY; without even the implied warranty of
16 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
17 GNU General Public License for more details.
18
19 You should have received a copy of the GNU General Public License
20 along with GCC; see the file COPYING3. If not see
21 <http://www.gnu.org/licenses/>. */
22
23
24 /* This file is part of the C++ front end.
25 It contains routines to build C++ expressions given their operands,
26 including computing the types of the result, C and C++ specific error
27 checks, and some optimization. */
28
29 #include "config.h"
30 #include "system.h"
31 #include "coretypes.h"
32 #include "tm.h"
33 #include "tree.h"
34 #include "cp-tree.h"
35 #include "flags.h"
36 #include "output.h"
37 #include "diagnostic.h"
38 #include "intl.h"
39 #include "target.h"
40 #include "convert.h"
41 #include "c-family/c-common.h"
42 #include "c-family/c-objc.h"
43 #include "params.h"
44
45 static tree pfn_from_ptrmemfunc (tree);
46 static tree delta_from_ptrmemfunc (tree);
47 static tree convert_for_assignment (tree, tree, impl_conv_rhs, tree, int,
48 tsubst_flags_t, int);
49 static tree cp_pointer_int_sum (enum tree_code, tree, tree);
50 static tree rationalize_conditional_expr (enum tree_code, tree,
51 tsubst_flags_t);
52 static int comp_ptr_ttypes_real (tree, tree, int);
53 static bool comp_except_types (tree, tree, bool);
54 static bool comp_array_types (const_tree, const_tree, bool);
55 static tree pointer_diff (tree, tree, tree);
56 static tree get_delta_difference (tree, tree, bool, bool, tsubst_flags_t);
57 static void casts_away_constness_r (tree *, tree *);
58 static bool casts_away_constness (tree, tree);
59 static void maybe_warn_about_returning_address_of_local (tree);
60 static tree lookup_destructor (tree, tree, tree);
61 static void warn_args_num (location_t, tree, bool);
62 static int convert_arguments (tree, VEC(tree,gc) **, tree, int,
63 tsubst_flags_t);
64
65 /* Do `exp = require_complete_type (exp);' to make sure exp
66 does not have an incomplete type. (That includes void types.)
67 Returns error_mark_node if the VALUE does not have
68 complete type when this function returns. */
69
70 tree
71 require_complete_type_sfinae (tree value, tsubst_flags_t complain)
72 {
73 tree type;
74
75 if (processing_template_decl || value == error_mark_node)
76 return value;
77
78 if (TREE_CODE (value) == OVERLOAD)
79 type = unknown_type_node;
80 else
81 type = TREE_TYPE (value);
82
83 if (type == error_mark_node)
84 return error_mark_node;
85
86 /* First, detect a valid value with a complete type. */
87 if (COMPLETE_TYPE_P (type))
88 return value;
89
90 if (complete_type_or_maybe_complain (type, value, complain))
91 return value;
92 else
93 return error_mark_node;
94 }
95
96 tree
97 require_complete_type (tree value)
98 {
99 return require_complete_type_sfinae (value, tf_warning_or_error);
100 }
101
102 /* Try to complete TYPE, if it is incomplete. For example, if TYPE is
103 a template instantiation, do the instantiation. Returns TYPE,
104 whether or not it could be completed, unless something goes
105 horribly wrong, in which case the error_mark_node is returned. */
106
107 tree
108 complete_type (tree type)
109 {
110 if (type == NULL_TREE)
111 /* Rather than crash, we return something sure to cause an error
112 at some point. */
113 return error_mark_node;
114
115 if (type == error_mark_node || COMPLETE_TYPE_P (type))
116 ;
117 else if (TREE_CODE (type) == ARRAY_TYPE && TYPE_DOMAIN (type))
118 {
119 tree t = complete_type (TREE_TYPE (type));
120 unsigned int needs_constructing, has_nontrivial_dtor;
121 if (COMPLETE_TYPE_P (t) && !dependent_type_p (type))
122 layout_type (type);
123 needs_constructing
124 = TYPE_NEEDS_CONSTRUCTING (TYPE_MAIN_VARIANT (t));
125 has_nontrivial_dtor
126 = TYPE_HAS_NONTRIVIAL_DESTRUCTOR (TYPE_MAIN_VARIANT (t));
127 for (t = TYPE_MAIN_VARIANT (type); t; t = TYPE_NEXT_VARIANT (t))
128 {
129 TYPE_NEEDS_CONSTRUCTING (t) = needs_constructing;
130 TYPE_HAS_NONTRIVIAL_DESTRUCTOR (t) = has_nontrivial_dtor;
131 }
132 }
133 else if (CLASS_TYPE_P (type) && CLASSTYPE_TEMPLATE_INSTANTIATION (type))
134 instantiate_class_template (TYPE_MAIN_VARIANT (type));
135
136 return type;
137 }
138
139 /* Like complete_type, but issue an error if the TYPE cannot be completed.
140 VALUE is used for informative diagnostics.
141 Returns NULL_TREE if the type cannot be made complete. */
142
143 tree
144 complete_type_or_maybe_complain (tree type, tree value, tsubst_flags_t complain)
145 {
146 type = complete_type (type);
147 if (type == error_mark_node)
148 /* We already issued an error. */
149 return NULL_TREE;
150 else if (!COMPLETE_TYPE_P (type))
151 {
152 if (complain & tf_error)
153 cxx_incomplete_type_diagnostic (value, type, DK_ERROR);
154 return NULL_TREE;
155 }
156 else
157 return type;
158 }
159
160 tree
161 complete_type_or_else (tree type, tree value)
162 {
163 return complete_type_or_maybe_complain (type, value, tf_warning_or_error);
164 }
165
166 /* Return truthvalue of whether type of EXP is instantiated. */
167
168 int
169 type_unknown_p (const_tree exp)
170 {
171 return (TREE_CODE (exp) == TREE_LIST
172 || TREE_TYPE (exp) == unknown_type_node);
173 }
174
175 \f
176 /* Return the common type of two parameter lists.
177 We assume that comptypes has already been done and returned 1;
178 if that isn't so, this may crash.
179
180 As an optimization, free the space we allocate if the parameter
181 lists are already common. */
182
183 static tree
184 commonparms (tree p1, tree p2)
185 {
186 tree oldargs = p1, newargs, n;
187 int i, len;
188 int any_change = 0;
189
190 len = list_length (p1);
191 newargs = tree_last (p1);
192
193 if (newargs == void_list_node)
194 i = 1;
195 else
196 {
197 i = 0;
198 newargs = 0;
199 }
200
201 for (; i < len; i++)
202 newargs = tree_cons (NULL_TREE, NULL_TREE, newargs);
203
204 n = newargs;
205
206 for (i = 0; p1;
207 p1 = TREE_CHAIN (p1), p2 = TREE_CHAIN (p2), n = TREE_CHAIN (n), i++)
208 {
209 if (TREE_PURPOSE (p1) && !TREE_PURPOSE (p2))
210 {
211 TREE_PURPOSE (n) = TREE_PURPOSE (p1);
212 any_change = 1;
213 }
214 else if (! TREE_PURPOSE (p1))
215 {
216 if (TREE_PURPOSE (p2))
217 {
218 TREE_PURPOSE (n) = TREE_PURPOSE (p2);
219 any_change = 1;
220 }
221 }
222 else
223 {
224 if (1 != simple_cst_equal (TREE_PURPOSE (p1), TREE_PURPOSE (p2)))
225 any_change = 1;
226 TREE_PURPOSE (n) = TREE_PURPOSE (p2);
227 }
228 if (TREE_VALUE (p1) != TREE_VALUE (p2))
229 {
230 any_change = 1;
231 TREE_VALUE (n) = merge_types (TREE_VALUE (p1), TREE_VALUE (p2));
232 }
233 else
234 TREE_VALUE (n) = TREE_VALUE (p1);
235 }
236 if (! any_change)
237 return oldargs;
238
239 return newargs;
240 }
241
242 /* Given a type, perhaps copied for a typedef,
243 find the "original" version of it. */
244 static tree
245 original_type (tree t)
246 {
247 int quals = cp_type_quals (t);
248 while (t != error_mark_node
249 && TYPE_NAME (t) != NULL_TREE)
250 {
251 tree x = TYPE_NAME (t);
252 if (TREE_CODE (x) != TYPE_DECL)
253 break;
254 x = DECL_ORIGINAL_TYPE (x);
255 if (x == NULL_TREE)
256 break;
257 t = x;
258 }
259 return cp_build_qualified_type (t, quals);
260 }
261
262 /* Return the common type for two arithmetic types T1 and T2 under the
263 usual arithmetic conversions. The default conversions have already
264 been applied, and enumerated types converted to their compatible
265 integer types. */
266
267 static tree
268 cp_common_type (tree t1, tree t2)
269 {
270 enum tree_code code1 = TREE_CODE (t1);
271 enum tree_code code2 = TREE_CODE (t2);
272 tree attributes;
273
274
275 /* In what follows, we slightly generalize the rules given in [expr] so
276 as to deal with `long long' and `complex'. First, merge the
277 attributes. */
278 attributes = (*targetm.merge_type_attributes) (t1, t2);
279
280 if (SCOPED_ENUM_P (t1) || SCOPED_ENUM_P (t2))
281 {
282 if (TYPE_MAIN_VARIANT (t1) == TYPE_MAIN_VARIANT (t2))
283 return build_type_attribute_variant (t1, attributes);
284 else
285 return NULL_TREE;
286 }
287
288 /* FIXME: Attributes. */
289 gcc_assert (ARITHMETIC_TYPE_P (t1)
290 || TREE_CODE (t1) == VECTOR_TYPE
291 || UNSCOPED_ENUM_P (t1));
292 gcc_assert (ARITHMETIC_TYPE_P (t2)
293 || TREE_CODE (t2) == VECTOR_TYPE
294 || UNSCOPED_ENUM_P (t2));
295
296 /* If one type is complex, form the common type of the non-complex
297 components, then make that complex. Use T1 or T2 if it is the
298 required type. */
299 if (code1 == COMPLEX_TYPE || code2 == COMPLEX_TYPE)
300 {
301 tree subtype1 = code1 == COMPLEX_TYPE ? TREE_TYPE (t1) : t1;
302 tree subtype2 = code2 == COMPLEX_TYPE ? TREE_TYPE (t2) : t2;
303 tree subtype
304 = type_after_usual_arithmetic_conversions (subtype1, subtype2);
305
306 if (code1 == COMPLEX_TYPE && TREE_TYPE (t1) == subtype)
307 return build_type_attribute_variant (t1, attributes);
308 else if (code2 == COMPLEX_TYPE && TREE_TYPE (t2) == subtype)
309 return build_type_attribute_variant (t2, attributes);
310 else
311 return build_type_attribute_variant (build_complex_type (subtype),
312 attributes);
313 }
314
315 if (code1 == VECTOR_TYPE)
316 {
317 /* When we get here we should have two vectors of the same size.
318 Just prefer the unsigned one if present. */
319 if (TYPE_UNSIGNED (t1))
320 return build_type_attribute_variant (t1, attributes);
321 else
322 return build_type_attribute_variant (t2, attributes);
323 }
324
325 /* If only one is real, use it as the result. */
326 if (code1 == REAL_TYPE && code2 != REAL_TYPE)
327 return build_type_attribute_variant (t1, attributes);
328 if (code2 == REAL_TYPE && code1 != REAL_TYPE)
329 return build_type_attribute_variant (t2, attributes);
330
331 /* Both real or both integers; use the one with greater precision. */
332 if (TYPE_PRECISION (t1) > TYPE_PRECISION (t2))
333 return build_type_attribute_variant (t1, attributes);
334 else if (TYPE_PRECISION (t2) > TYPE_PRECISION (t1))
335 return build_type_attribute_variant (t2, attributes);
336
337 /* The types are the same; no need to do anything fancy. */
338 if (TYPE_MAIN_VARIANT (t1) == TYPE_MAIN_VARIANT (t2))
339 return build_type_attribute_variant (t1, attributes);
340
341 if (code1 != REAL_TYPE)
342 {
343 /* If one is unsigned long long, then convert the other to unsigned
344 long long. */
345 if (same_type_p (TYPE_MAIN_VARIANT (t1), long_long_unsigned_type_node)
346 || same_type_p (TYPE_MAIN_VARIANT (t2), long_long_unsigned_type_node))
347 return build_type_attribute_variant (long_long_unsigned_type_node,
348 attributes);
349 /* If one is a long long, and the other is an unsigned long, and
350 long long can represent all the values of an unsigned long, then
351 convert to a long long. Otherwise, convert to an unsigned long
352 long. Otherwise, if either operand is long long, convert the
353 other to long long.
354
355 Since we're here, we know the TYPE_PRECISION is the same;
356 therefore converting to long long cannot represent all the values
357 of an unsigned long, so we choose unsigned long long in that
358 case. */
359 if (same_type_p (TYPE_MAIN_VARIANT (t1), long_long_integer_type_node)
360 || same_type_p (TYPE_MAIN_VARIANT (t2), long_long_integer_type_node))
361 {
362 tree t = ((TYPE_UNSIGNED (t1) || TYPE_UNSIGNED (t2))
363 ? long_long_unsigned_type_node
364 : long_long_integer_type_node);
365 return build_type_attribute_variant (t, attributes);
366 }
367 if (int128_integer_type_node != NULL_TREE
368 && (same_type_p (TYPE_MAIN_VARIANT (t1),
369 int128_integer_type_node)
370 || same_type_p (TYPE_MAIN_VARIANT (t2),
371 int128_integer_type_node)))
372 {
373 tree t = ((TYPE_UNSIGNED (t1) || TYPE_UNSIGNED (t2))
374 ? int128_unsigned_type_node
375 : int128_integer_type_node);
376 return build_type_attribute_variant (t, attributes);
377 }
378
379 /* Go through the same procedure, but for longs. */
380 if (same_type_p (TYPE_MAIN_VARIANT (t1), long_unsigned_type_node)
381 || same_type_p (TYPE_MAIN_VARIANT (t2), long_unsigned_type_node))
382 return build_type_attribute_variant (long_unsigned_type_node,
383 attributes);
384 if (same_type_p (TYPE_MAIN_VARIANT (t1), long_integer_type_node)
385 || same_type_p (TYPE_MAIN_VARIANT (t2), long_integer_type_node))
386 {
387 tree t = ((TYPE_UNSIGNED (t1) || TYPE_UNSIGNED (t2))
388 ? long_unsigned_type_node : long_integer_type_node);
389 return build_type_attribute_variant (t, attributes);
390 }
391 /* Otherwise prefer the unsigned one. */
392 if (TYPE_UNSIGNED (t1))
393 return build_type_attribute_variant (t1, attributes);
394 else
395 return build_type_attribute_variant (t2, attributes);
396 }
397 else
398 {
399 if (same_type_p (TYPE_MAIN_VARIANT (t1), long_double_type_node)
400 || same_type_p (TYPE_MAIN_VARIANT (t2), long_double_type_node))
401 return build_type_attribute_variant (long_double_type_node,
402 attributes);
403 if (same_type_p (TYPE_MAIN_VARIANT (t1), double_type_node)
404 || same_type_p (TYPE_MAIN_VARIANT (t2), double_type_node))
405 return build_type_attribute_variant (double_type_node,
406 attributes);
407 if (same_type_p (TYPE_MAIN_VARIANT (t1), float_type_node)
408 || same_type_p (TYPE_MAIN_VARIANT (t2), float_type_node))
409 return build_type_attribute_variant (float_type_node,
410 attributes);
411
412 /* Two floating-point types whose TYPE_MAIN_VARIANTs are none of
413 the standard C++ floating-point types. Logic earlier in this
414 function has already eliminated the possibility that
415 TYPE_PRECISION (t2) != TYPE_PRECISION (t1), so there's no
416 compelling reason to choose one or the other. */
417 return build_type_attribute_variant (t1, attributes);
418 }
419 }
420
421 /* T1 and T2 are arithmetic or enumeration types. Return the type
422 that will result from the "usual arithmetic conversions" on T1 and
423 T2 as described in [expr]. */
424
425 tree
426 type_after_usual_arithmetic_conversions (tree t1, tree t2)
427 {
428 gcc_assert (ARITHMETIC_TYPE_P (t1)
429 || TREE_CODE (t1) == VECTOR_TYPE
430 || UNSCOPED_ENUM_P (t1));
431 gcc_assert (ARITHMETIC_TYPE_P (t2)
432 || TREE_CODE (t2) == VECTOR_TYPE
433 || UNSCOPED_ENUM_P (t2));
434
435 /* Perform the integral promotions. We do not promote real types here. */
436 if (INTEGRAL_OR_ENUMERATION_TYPE_P (t1)
437 && INTEGRAL_OR_ENUMERATION_TYPE_P (t2))
438 {
439 t1 = type_promotes_to (t1);
440 t2 = type_promotes_to (t2);
441 }
442
443 return cp_common_type (t1, t2);
444 }
445
446 static void
447 composite_pointer_error (diagnostic_t kind, tree t1, tree t2,
448 composite_pointer_operation operation)
449 {
450 switch (operation)
451 {
452 case CPO_COMPARISON:
453 emit_diagnostic (kind, input_location, 0,
454 "comparison between "
455 "distinct pointer types %qT and %qT lacks a cast",
456 t1, t2);
457 break;
458 case CPO_CONVERSION:
459 emit_diagnostic (kind, input_location, 0,
460 "conversion between "
461 "distinct pointer types %qT and %qT lacks a cast",
462 t1, t2);
463 break;
464 case CPO_CONDITIONAL_EXPR:
465 emit_diagnostic (kind, input_location, 0,
466 "conditional expression between "
467 "distinct pointer types %qT and %qT lacks a cast",
468 t1, t2);
469 break;
470 default:
471 gcc_unreachable ();
472 }
473 }
474
475 /* Subroutine of composite_pointer_type to implement the recursive
476 case. See that function for documentation of the parameters. */
477
478 static tree
479 composite_pointer_type_r (tree t1, tree t2,
480 composite_pointer_operation operation,
481 tsubst_flags_t complain)
482 {
483 tree pointee1;
484 tree pointee2;
485 tree result_type;
486 tree attributes;
487
488 /* Determine the types pointed to by T1 and T2. */
489 if (TREE_CODE (t1) == POINTER_TYPE)
490 {
491 pointee1 = TREE_TYPE (t1);
492 pointee2 = TREE_TYPE (t2);
493 }
494 else
495 {
496 pointee1 = TYPE_PTRMEM_POINTED_TO_TYPE (t1);
497 pointee2 = TYPE_PTRMEM_POINTED_TO_TYPE (t2);
498 }
499
500 /* [expr.rel]
501
502 Otherwise, the composite pointer type is a pointer type
503 similar (_conv.qual_) to the type of one of the operands,
504 with a cv-qualification signature (_conv.qual_) that is the
505 union of the cv-qualification signatures of the operand
506 types. */
507 if (same_type_ignoring_top_level_qualifiers_p (pointee1, pointee2))
508 result_type = pointee1;
509 else if ((TREE_CODE (pointee1) == POINTER_TYPE
510 && TREE_CODE (pointee2) == POINTER_TYPE)
511 || (TYPE_PTR_TO_MEMBER_P (pointee1)
512 && TYPE_PTR_TO_MEMBER_P (pointee2)))
513 result_type = composite_pointer_type_r (pointee1, pointee2, operation,
514 complain);
515 else
516 {
517 if (complain & tf_error)
518 composite_pointer_error (DK_PERMERROR, t1, t2, operation);
519
520 result_type = void_type_node;
521 }
522 result_type = cp_build_qualified_type (result_type,
523 (cp_type_quals (pointee1)
524 | cp_type_quals (pointee2)));
525 /* If the original types were pointers to members, so is the
526 result. */
527 if (TYPE_PTR_TO_MEMBER_P (t1))
528 {
529 if (!same_type_p (TYPE_PTRMEM_CLASS_TYPE (t1),
530 TYPE_PTRMEM_CLASS_TYPE (t2))
531 && (complain & tf_error))
532 composite_pointer_error (DK_PERMERROR, t1, t2, operation);
533 result_type = build_ptrmem_type (TYPE_PTRMEM_CLASS_TYPE (t1),
534 result_type);
535 }
536 else
537 result_type = build_pointer_type (result_type);
538
539 /* Merge the attributes. */
540 attributes = (*targetm.merge_type_attributes) (t1, t2);
541 return build_type_attribute_variant (result_type, attributes);
542 }
543
544 /* Return the composite pointer type (see [expr.rel]) for T1 and T2.
545 ARG1 and ARG2 are the values with those types. The OPERATION is to
546 describe the operation between the pointer types,
547 in case an error occurs.
548
549 This routine also implements the computation of a common type for
550 pointers-to-members as per [expr.eq]. */
551
552 tree
553 composite_pointer_type (tree t1, tree t2, tree arg1, tree arg2,
554 composite_pointer_operation operation,
555 tsubst_flags_t complain)
556 {
557 tree class1;
558 tree class2;
559
560 /* [expr.rel]
561
562 If one operand is a null pointer constant, the composite pointer
563 type is the type of the other operand. */
564 if (null_ptr_cst_p (arg1))
565 return t2;
566 if (null_ptr_cst_p (arg2))
567 return t1;
568
569 /* We have:
570
571 [expr.rel]
572
573 If one of the operands has type "pointer to cv1 void*", then
574 the other has type "pointer to cv2T", and the composite pointer
575 type is "pointer to cv12 void", where cv12 is the union of cv1
576 and cv2.
577
578 If either type is a pointer to void, make sure it is T1. */
579 if (TREE_CODE (t2) == POINTER_TYPE && VOID_TYPE_P (TREE_TYPE (t2)))
580 {
581 tree t;
582 t = t1;
583 t1 = t2;
584 t2 = t;
585 }
586
587 /* Now, if T1 is a pointer to void, merge the qualifiers. */
588 if (TREE_CODE (t1) == POINTER_TYPE && VOID_TYPE_P (TREE_TYPE (t1)))
589 {
590 tree attributes;
591 tree result_type;
592
593 if (TYPE_PTRFN_P (t2) && (complain & tf_error))
594 {
595 switch (operation)
596 {
597 case CPO_COMPARISON:
598 pedwarn (input_location, OPT_pedantic,
599 "ISO C++ forbids comparison between "
600 "pointer of type %<void *%> and pointer-to-function");
601 break;
602 case CPO_CONVERSION:
603 pedwarn (input_location, OPT_pedantic,
604 "ISO C++ forbids conversion between "
605 "pointer of type %<void *%> and pointer-to-function");
606 break;
607 case CPO_CONDITIONAL_EXPR:
608 pedwarn (input_location, OPT_pedantic,
609 "ISO C++ forbids conditional expression between "
610 "pointer of type %<void *%> and pointer-to-function");
611 break;
612 default:
613 gcc_unreachable ();
614 }
615 }
616 result_type
617 = cp_build_qualified_type (void_type_node,
618 (cp_type_quals (TREE_TYPE (t1))
619 | cp_type_quals (TREE_TYPE (t2))));
620 result_type = build_pointer_type (result_type);
621 /* Merge the attributes. */
622 attributes = (*targetm.merge_type_attributes) (t1, t2);
623 return build_type_attribute_variant (result_type, attributes);
624 }
625
626 if (c_dialect_objc () && TREE_CODE (t1) == POINTER_TYPE
627 && TREE_CODE (t2) == POINTER_TYPE)
628 {
629 if (objc_have_common_type (t1, t2, -3, NULL_TREE))
630 return objc_common_type (t1, t2);
631 }
632
633 /* [expr.eq] permits the application of a pointer conversion to
634 bring the pointers to a common type. */
635 if (TREE_CODE (t1) == POINTER_TYPE && TREE_CODE (t2) == POINTER_TYPE
636 && CLASS_TYPE_P (TREE_TYPE (t1))
637 && CLASS_TYPE_P (TREE_TYPE (t2))
638 && !same_type_ignoring_top_level_qualifiers_p (TREE_TYPE (t1),
639 TREE_TYPE (t2)))
640 {
641 class1 = TREE_TYPE (t1);
642 class2 = TREE_TYPE (t2);
643
644 if (DERIVED_FROM_P (class1, class2))
645 t2 = (build_pointer_type
646 (cp_build_qualified_type (class1, cp_type_quals (class2))));
647 else if (DERIVED_FROM_P (class2, class1))
648 t1 = (build_pointer_type
649 (cp_build_qualified_type (class2, cp_type_quals (class1))));
650 else
651 {
652 if (complain & tf_error)
653 composite_pointer_error (DK_ERROR, t1, t2, operation);
654 return error_mark_node;
655 }
656 }
657 /* [expr.eq] permits the application of a pointer-to-member
658 conversion to change the class type of one of the types. */
659 else if (TYPE_PTR_TO_MEMBER_P (t1)
660 && !same_type_p (TYPE_PTRMEM_CLASS_TYPE (t1),
661 TYPE_PTRMEM_CLASS_TYPE (t2)))
662 {
663 class1 = TYPE_PTRMEM_CLASS_TYPE (t1);
664 class2 = TYPE_PTRMEM_CLASS_TYPE (t2);
665
666 if (DERIVED_FROM_P (class1, class2))
667 t1 = build_ptrmem_type (class2, TYPE_PTRMEM_POINTED_TO_TYPE (t1));
668 else if (DERIVED_FROM_P (class2, class1))
669 t2 = build_ptrmem_type (class1, TYPE_PTRMEM_POINTED_TO_TYPE (t2));
670 else
671 {
672 if (complain & tf_error)
673 switch (operation)
674 {
675 case CPO_COMPARISON:
676 error ("comparison between distinct "
677 "pointer-to-member types %qT and %qT lacks a cast",
678 t1, t2);
679 break;
680 case CPO_CONVERSION:
681 error ("conversion between distinct "
682 "pointer-to-member types %qT and %qT lacks a cast",
683 t1, t2);
684 break;
685 case CPO_CONDITIONAL_EXPR:
686 error ("conditional expression between distinct "
687 "pointer-to-member types %qT and %qT lacks a cast",
688 t1, t2);
689 break;
690 default:
691 gcc_unreachable ();
692 }
693 return error_mark_node;
694 }
695 }
696
697 return composite_pointer_type_r (t1, t2, operation, complain);
698 }
699
700 /* Return the merged type of two types.
701 We assume that comptypes has already been done and returned 1;
702 if that isn't so, this may crash.
703
704 This just combines attributes and default arguments; any other
705 differences would cause the two types to compare unalike. */
706
707 tree
708 merge_types (tree t1, tree t2)
709 {
710 enum tree_code code1;
711 enum tree_code code2;
712 tree attributes;
713
714 /* Save time if the two types are the same. */
715 if (t1 == t2)
716 return t1;
717 if (original_type (t1) == original_type (t2))
718 return t1;
719
720 /* If one type is nonsense, use the other. */
721 if (t1 == error_mark_node)
722 return t2;
723 if (t2 == error_mark_node)
724 return t1;
725
726 /* Merge the attributes. */
727 attributes = (*targetm.merge_type_attributes) (t1, t2);
728
729 if (TYPE_PTRMEMFUNC_P (t1))
730 t1 = TYPE_PTRMEMFUNC_FN_TYPE (t1);
731 if (TYPE_PTRMEMFUNC_P (t2))
732 t2 = TYPE_PTRMEMFUNC_FN_TYPE (t2);
733
734 code1 = TREE_CODE (t1);
735 code2 = TREE_CODE (t2);
736 if (code1 != code2)
737 {
738 gcc_assert (code1 == TYPENAME_TYPE || code2 == TYPENAME_TYPE);
739 if (code1 == TYPENAME_TYPE)
740 {
741 t1 = resolve_typename_type (t1, /*only_current_p=*/true);
742 code1 = TREE_CODE (t1);
743 }
744 else
745 {
746 t2 = resolve_typename_type (t2, /*only_current_p=*/true);
747 code2 = TREE_CODE (t2);
748 }
749 }
750
751 switch (code1)
752 {
753 case POINTER_TYPE:
754 case REFERENCE_TYPE:
755 /* For two pointers, do this recursively on the target type. */
756 {
757 tree target = merge_types (TREE_TYPE (t1), TREE_TYPE (t2));
758 int quals = cp_type_quals (t1);
759
760 if (code1 == POINTER_TYPE)
761 t1 = build_pointer_type (target);
762 else
763 t1 = cp_build_reference_type (target, TYPE_REF_IS_RVALUE (t1));
764 t1 = build_type_attribute_variant (t1, attributes);
765 t1 = cp_build_qualified_type (t1, quals);
766
767 if (TREE_CODE (target) == METHOD_TYPE)
768 t1 = build_ptrmemfunc_type (t1);
769
770 return t1;
771 }
772
773 case OFFSET_TYPE:
774 {
775 int quals;
776 tree pointee;
777 quals = cp_type_quals (t1);
778 pointee = merge_types (TYPE_PTRMEM_POINTED_TO_TYPE (t1),
779 TYPE_PTRMEM_POINTED_TO_TYPE (t2));
780 t1 = build_ptrmem_type (TYPE_PTRMEM_CLASS_TYPE (t1),
781 pointee);
782 t1 = cp_build_qualified_type (t1, quals);
783 break;
784 }
785
786 case ARRAY_TYPE:
787 {
788 tree elt = merge_types (TREE_TYPE (t1), TREE_TYPE (t2));
789 /* Save space: see if the result is identical to one of the args. */
790 if (elt == TREE_TYPE (t1) && TYPE_DOMAIN (t1))
791 return build_type_attribute_variant (t1, attributes);
792 if (elt == TREE_TYPE (t2) && TYPE_DOMAIN (t2))
793 return build_type_attribute_variant (t2, attributes);
794 /* Merge the element types, and have a size if either arg has one. */
795 t1 = build_cplus_array_type
796 (elt, TYPE_DOMAIN (TYPE_DOMAIN (t1) ? t1 : t2));
797 break;
798 }
799
800 case FUNCTION_TYPE:
801 /* Function types: prefer the one that specified arg types.
802 If both do, merge the arg types. Also merge the return types. */
803 {
804 tree valtype = merge_types (TREE_TYPE (t1), TREE_TYPE (t2));
805 tree p1 = TYPE_ARG_TYPES (t1);
806 tree p2 = TYPE_ARG_TYPES (t2);
807 tree parms;
808 tree rval, raises;
809
810 /* Save space: see if the result is identical to one of the args. */
811 if (valtype == TREE_TYPE (t1) && ! p2)
812 return cp_build_type_attribute_variant (t1, attributes);
813 if (valtype == TREE_TYPE (t2) && ! p1)
814 return cp_build_type_attribute_variant (t2, attributes);
815
816 /* Simple way if one arg fails to specify argument types. */
817 if (p1 == NULL_TREE || TREE_VALUE (p1) == void_type_node)
818 parms = p2;
819 else if (p2 == NULL_TREE || TREE_VALUE (p2) == void_type_node)
820 parms = p1;
821 else
822 parms = commonparms (p1, p2);
823
824 rval = build_function_type (valtype, parms);
825 gcc_assert (type_memfn_quals (t1) == type_memfn_quals (t2));
826 rval = apply_memfn_quals (rval, type_memfn_quals (t1));
827 raises = merge_exception_specifiers (TYPE_RAISES_EXCEPTIONS (t1),
828 TYPE_RAISES_EXCEPTIONS (t2));
829 t1 = build_exception_variant (rval, raises);
830 break;
831 }
832
833 case METHOD_TYPE:
834 {
835 /* Get this value the long way, since TYPE_METHOD_BASETYPE
836 is just the main variant of this. */
837 tree basetype = TREE_TYPE (TREE_VALUE (TYPE_ARG_TYPES (t2)));
838 tree raises = merge_exception_specifiers (TYPE_RAISES_EXCEPTIONS (t1),
839 TYPE_RAISES_EXCEPTIONS (t2));
840 tree t3;
841
842 /* If this was a member function type, get back to the
843 original type of type member function (i.e., without
844 the class instance variable up front. */
845 t1 = build_function_type (TREE_TYPE (t1),
846 TREE_CHAIN (TYPE_ARG_TYPES (t1)));
847 t2 = build_function_type (TREE_TYPE (t2),
848 TREE_CHAIN (TYPE_ARG_TYPES (t2)));
849 t3 = merge_types (t1, t2);
850 t3 = build_method_type_directly (basetype, TREE_TYPE (t3),
851 TYPE_ARG_TYPES (t3));
852 t1 = build_exception_variant (t3, raises);
853 break;
854 }
855
856 case TYPENAME_TYPE:
857 /* There is no need to merge attributes into a TYPENAME_TYPE.
858 When the type is instantiated it will have whatever
859 attributes result from the instantiation. */
860 return t1;
861
862 default:;
863 }
864
865 if (attribute_list_equal (TYPE_ATTRIBUTES (t1), attributes))
866 return t1;
867 else if (attribute_list_equal (TYPE_ATTRIBUTES (t2), attributes))
868 return t2;
869 else
870 return cp_build_type_attribute_variant (t1, attributes);
871 }
872
873 /* Return the ARRAY_TYPE type without its domain. */
874
875 tree
876 strip_array_domain (tree type)
877 {
878 tree t2;
879 gcc_assert (TREE_CODE (type) == ARRAY_TYPE);
880 if (TYPE_DOMAIN (type) == NULL_TREE)
881 return type;
882 t2 = build_cplus_array_type (TREE_TYPE (type), NULL_TREE);
883 return cp_build_type_attribute_variant (t2, TYPE_ATTRIBUTES (type));
884 }
885
886 /* Wrapper around cp_common_type that is used by c-common.c and other
887 front end optimizations that remove promotions.
888
889 Return the common type for two arithmetic types T1 and T2 under the
890 usual arithmetic conversions. The default conversions have already
891 been applied, and enumerated types converted to their compatible
892 integer types. */
893
894 tree
895 common_type (tree t1, tree t2)
896 {
897 /* If one type is nonsense, use the other */
898 if (t1 == error_mark_node)
899 return t2;
900 if (t2 == error_mark_node)
901 return t1;
902
903 return cp_common_type (t1, t2);
904 }
905
906 /* Return the common type of two pointer types T1 and T2. This is the
907 type for the result of most arithmetic operations if the operands
908 have the given two types.
909
910 We assume that comp_target_types has already been done and returned
911 nonzero; if that isn't so, this may crash. */
912
913 tree
914 common_pointer_type (tree t1, tree t2)
915 {
916 gcc_assert ((TYPE_PTR_P (t1) && TYPE_PTR_P (t2))
917 || (TYPE_PTRMEM_P (t1) && TYPE_PTRMEM_P (t2))
918 || (TYPE_PTRMEMFUNC_P (t1) && TYPE_PTRMEMFUNC_P (t2)));
919
920 return composite_pointer_type (t1, t2, error_mark_node, error_mark_node,
921 CPO_CONVERSION, tf_warning_or_error);
922 }
923 \f
924 /* Compare two exception specifier types for exactness or subsetness, if
925 allowed. Returns false for mismatch, true for match (same, or
926 derived and !exact).
927
928 [except.spec] "If a class X ... objects of class X or any class publicly
929 and unambiguously derived from X. Similarly, if a pointer type Y * ...
930 exceptions of type Y * or that are pointers to any type publicly and
931 unambiguously derived from Y. Otherwise a function only allows exceptions
932 that have the same type ..."
933 This does not mention cv qualifiers and is different to what throw
934 [except.throw] and catch [except.catch] will do. They will ignore the
935 top level cv qualifiers, and allow qualifiers in the pointer to class
936 example.
937
938 We implement the letter of the standard. */
939
940 static bool
941 comp_except_types (tree a, tree b, bool exact)
942 {
943 if (same_type_p (a, b))
944 return true;
945 else if (!exact)
946 {
947 if (cp_type_quals (a) || cp_type_quals (b))
948 return false;
949
950 if (TREE_CODE (a) == POINTER_TYPE
951 && TREE_CODE (b) == POINTER_TYPE)
952 {
953 a = TREE_TYPE (a);
954 b = TREE_TYPE (b);
955 if (cp_type_quals (a) || cp_type_quals (b))
956 return false;
957 }
958
959 if (TREE_CODE (a) != RECORD_TYPE
960 || TREE_CODE (b) != RECORD_TYPE)
961 return false;
962
963 if (PUBLICLY_UNIQUELY_DERIVED_P (a, b))
964 return true;
965 }
966 return false;
967 }
968
969 /* Return true if TYPE1 and TYPE2 are equivalent exception specifiers.
970 If EXACT is ce_derived, T2 can be stricter than T1 (according to 15.4/5).
971 If EXACT is ce_normal, the compatibility rules in 15.4/3 apply.
972 If EXACT is ce_exact, the specs must be exactly the same. Exception lists
973 are unordered, but we've already filtered out duplicates. Most lists will
974 be in order, we should try to make use of that. */
975
976 bool
977 comp_except_specs (const_tree t1, const_tree t2, int exact)
978 {
979 const_tree probe;
980 const_tree base;
981 int length = 0;
982
983 if (t1 == t2)
984 return true;
985
986 /* First handle noexcept. */
987 if (exact < ce_exact)
988 {
989 /* noexcept(false) is compatible with any throwing dynamic-exc-spec
990 and stricter than any spec. */
991 if (t1 == noexcept_false_spec)
992 return !nothrow_spec_p (t2) || exact == ce_derived;
993 /* Even a derived noexcept(false) is compatible with a throwing
994 dynamic spec. */
995 if (t2 == noexcept_false_spec)
996 return !nothrow_spec_p (t1);
997
998 /* Otherwise, if we aren't looking for an exact match, noexcept is
999 equivalent to throw(). */
1000 if (t1 == noexcept_true_spec)
1001 t1 = empty_except_spec;
1002 if (t2 == noexcept_true_spec)
1003 t2 = empty_except_spec;
1004 }
1005
1006 /* If any noexcept is left, it is only comparable to itself;
1007 either we're looking for an exact match or we're redeclaring a
1008 template with dependent noexcept. */
1009 if ((t1 && TREE_PURPOSE (t1))
1010 || (t2 && TREE_PURPOSE (t2)))
1011 return (t1 && t2
1012 && cp_tree_equal (TREE_PURPOSE (t1), TREE_PURPOSE (t2)));
1013
1014 if (t1 == NULL_TREE) /* T1 is ... */
1015 return t2 == NULL_TREE || exact == ce_derived;
1016 if (!TREE_VALUE (t1)) /* t1 is EMPTY */
1017 return t2 != NULL_TREE && !TREE_VALUE (t2);
1018 if (t2 == NULL_TREE) /* T2 is ... */
1019 return false;
1020 if (TREE_VALUE (t1) && !TREE_VALUE (t2)) /* T2 is EMPTY, T1 is not */
1021 return exact == ce_derived;
1022
1023 /* Neither set is ... or EMPTY, make sure each part of T2 is in T1.
1024 Count how many we find, to determine exactness. For exact matching and
1025 ordered T1, T2, this is an O(n) operation, otherwise its worst case is
1026 O(nm). */
1027 for (base = t1; t2 != NULL_TREE; t2 = TREE_CHAIN (t2))
1028 {
1029 for (probe = base; probe != NULL_TREE; probe = TREE_CHAIN (probe))
1030 {
1031 tree a = TREE_VALUE (probe);
1032 tree b = TREE_VALUE (t2);
1033
1034 if (comp_except_types (a, b, exact))
1035 {
1036 if (probe == base && exact > ce_derived)
1037 base = TREE_CHAIN (probe);
1038 length++;
1039 break;
1040 }
1041 }
1042 if (probe == NULL_TREE)
1043 return false;
1044 }
1045 return exact == ce_derived || base == NULL_TREE || length == list_length (t1);
1046 }
1047
1048 /* Compare the array types T1 and T2. ALLOW_REDECLARATION is true if
1049 [] can match [size]. */
1050
1051 static bool
1052 comp_array_types (const_tree t1, const_tree t2, bool allow_redeclaration)
1053 {
1054 tree d1;
1055 tree d2;
1056 tree max1, max2;
1057
1058 if (t1 == t2)
1059 return true;
1060
1061 /* The type of the array elements must be the same. */
1062 if (!same_type_p (TREE_TYPE (t1), TREE_TYPE (t2)))
1063 return false;
1064
1065 d1 = TYPE_DOMAIN (t1);
1066 d2 = TYPE_DOMAIN (t2);
1067
1068 if (d1 == d2)
1069 return true;
1070
1071 /* If one of the arrays is dimensionless, and the other has a
1072 dimension, they are of different types. However, it is valid to
1073 write:
1074
1075 extern int a[];
1076 int a[3];
1077
1078 by [basic.link]:
1079
1080 declarations for an array object can specify
1081 array types that differ by the presence or absence of a major
1082 array bound (_dcl.array_). */
1083 if (!d1 || !d2)
1084 return allow_redeclaration;
1085
1086 /* Check that the dimensions are the same. */
1087
1088 if (!cp_tree_equal (TYPE_MIN_VALUE (d1), TYPE_MIN_VALUE (d2)))
1089 return false;
1090 max1 = TYPE_MAX_VALUE (d1);
1091 max2 = TYPE_MAX_VALUE (d2);
1092 if (processing_template_decl && !abi_version_at_least (2)
1093 && !value_dependent_expression_p (max1)
1094 && !value_dependent_expression_p (max2))
1095 {
1096 /* With abi-1 we do not fold non-dependent array bounds, (and
1097 consequently mangle them incorrectly). We must therefore
1098 fold them here, to verify the domains have the same
1099 value. */
1100 max1 = fold (max1);
1101 max2 = fold (max2);
1102 }
1103
1104 if (!cp_tree_equal (max1, max2))
1105 return false;
1106
1107 return true;
1108 }
1109
1110 /* Compare the relative position of T1 and T2 into their respective
1111 template parameter list.
1112 T1 and T2 must be template parameter types.
1113 Return TRUE if T1 and T2 have the same position, FALSE otherwise. */
1114
1115 static bool
1116 comp_template_parms_position (tree t1, tree t2)
1117 {
1118 tree index1, index2;
1119 gcc_assert (t1 && t2
1120 && TREE_CODE (t1) == TREE_CODE (t2)
1121 && (TREE_CODE (t1) == BOUND_TEMPLATE_TEMPLATE_PARM
1122 || TREE_CODE (t1) == TEMPLATE_TEMPLATE_PARM
1123 || TREE_CODE (t1) == TEMPLATE_TYPE_PARM));
1124
1125 index1 = TEMPLATE_TYPE_PARM_INDEX (TYPE_MAIN_VARIANT (t1));
1126 index2 = TEMPLATE_TYPE_PARM_INDEX (TYPE_MAIN_VARIANT (t2));
1127
1128 /* If T1 and T2 belong to template parm lists of different size,
1129 let's assume they are different. */
1130 if (TEMPLATE_PARM_NUM_SIBLINGS (index1)
1131 != TEMPLATE_PARM_NUM_SIBLINGS (index2))
1132 return false;
1133
1134 /* Then compare their relative position. */
1135 if (TEMPLATE_PARM_IDX (index1) != TEMPLATE_PARM_IDX (index2)
1136 || TEMPLATE_PARM_LEVEL (index1) != TEMPLATE_PARM_LEVEL (index2)
1137 || (TEMPLATE_PARM_PARAMETER_PACK (index1)
1138 != TEMPLATE_PARM_PARAMETER_PACK (index2)))
1139 return false;
1140
1141 return true;
1142 }
1143
1144 /* Subroutine in comptypes. */
1145
1146 static bool
1147 structural_comptypes (tree t1, tree t2, int strict)
1148 {
1149 if (t1 == t2)
1150 return true;
1151
1152 /* Suppress errors caused by previously reported errors. */
1153 if (t1 == error_mark_node || t2 == error_mark_node)
1154 return false;
1155
1156 gcc_assert (TYPE_P (t1) && TYPE_P (t2));
1157
1158 /* TYPENAME_TYPEs should be resolved if the qualifying scope is the
1159 current instantiation. */
1160 if (TREE_CODE (t1) == TYPENAME_TYPE)
1161 t1 = resolve_typename_type (t1, /*only_current_p=*/true);
1162
1163 if (TREE_CODE (t2) == TYPENAME_TYPE)
1164 t2 = resolve_typename_type (t2, /*only_current_p=*/true);
1165
1166 if (TYPE_PTRMEMFUNC_P (t1))
1167 t1 = TYPE_PTRMEMFUNC_FN_TYPE (t1);
1168 if (TYPE_PTRMEMFUNC_P (t2))
1169 t2 = TYPE_PTRMEMFUNC_FN_TYPE (t2);
1170
1171 /* Different classes of types can't be compatible. */
1172 if (TREE_CODE (t1) != TREE_CODE (t2))
1173 return false;
1174
1175 /* Qualifiers must match. For array types, we will check when we
1176 recur on the array element types. */
1177 if (TREE_CODE (t1) != ARRAY_TYPE
1178 && cp_type_quals (t1) != cp_type_quals (t2))
1179 return false;
1180 if (TREE_CODE (t1) == FUNCTION_TYPE
1181 && type_memfn_quals (t1) != type_memfn_quals (t2))
1182 return false;
1183 if (TYPE_FOR_JAVA (t1) != TYPE_FOR_JAVA (t2))
1184 return false;
1185
1186 /* Allow for two different type nodes which have essentially the same
1187 definition. Note that we already checked for equality of the type
1188 qualifiers (just above). */
1189
1190 if (TREE_CODE (t1) != ARRAY_TYPE
1191 && TYPE_MAIN_VARIANT (t1) == TYPE_MAIN_VARIANT (t2))
1192 return true;
1193
1194
1195 /* Compare the types. Break out if they could be the same. */
1196 switch (TREE_CODE (t1))
1197 {
1198 case VOID_TYPE:
1199 case BOOLEAN_TYPE:
1200 /* All void and bool types are the same. */
1201 break;
1202
1203 case INTEGER_TYPE:
1204 case FIXED_POINT_TYPE:
1205 case REAL_TYPE:
1206 /* With these nodes, we can't determine type equivalence by
1207 looking at what is stored in the nodes themselves, because
1208 two nodes might have different TYPE_MAIN_VARIANTs but still
1209 represent the same type. For example, wchar_t and int could
1210 have the same properties (TYPE_PRECISION, TYPE_MIN_VALUE,
1211 TYPE_MAX_VALUE, etc.), but have different TYPE_MAIN_VARIANTs
1212 and are distinct types. On the other hand, int and the
1213 following typedef
1214
1215 typedef int INT __attribute((may_alias));
1216
1217 have identical properties, different TYPE_MAIN_VARIANTs, but
1218 represent the same type. The canonical type system keeps
1219 track of equivalence in this case, so we fall back on it. */
1220 return TYPE_CANONICAL (t1) == TYPE_CANONICAL (t2);
1221
1222 case TEMPLATE_TEMPLATE_PARM:
1223 case BOUND_TEMPLATE_TEMPLATE_PARM:
1224 if (!comp_template_parms_position (t1, t2))
1225 return false;
1226 if (!comp_template_parms
1227 (DECL_TEMPLATE_PARMS (TEMPLATE_TEMPLATE_PARM_TEMPLATE_DECL (t1)),
1228 DECL_TEMPLATE_PARMS (TEMPLATE_TEMPLATE_PARM_TEMPLATE_DECL (t2))))
1229 return false;
1230 if (TREE_CODE (t1) == TEMPLATE_TEMPLATE_PARM)
1231 break;
1232 /* Don't check inheritance. */
1233 strict = COMPARE_STRICT;
1234 /* Fall through. */
1235
1236 case RECORD_TYPE:
1237 case UNION_TYPE:
1238 if (TYPE_TEMPLATE_INFO (t1) && TYPE_TEMPLATE_INFO (t2)
1239 && (TYPE_TI_TEMPLATE (t1) == TYPE_TI_TEMPLATE (t2)
1240 || TREE_CODE (t1) == BOUND_TEMPLATE_TEMPLATE_PARM)
1241 && comp_template_args (TYPE_TI_ARGS (t1), TYPE_TI_ARGS (t2)))
1242 break;
1243
1244 if ((strict & COMPARE_BASE) && DERIVED_FROM_P (t1, t2))
1245 break;
1246 else if ((strict & COMPARE_DERIVED) && DERIVED_FROM_P (t2, t1))
1247 break;
1248
1249 return false;
1250
1251 case OFFSET_TYPE:
1252 if (!comptypes (TYPE_OFFSET_BASETYPE (t1), TYPE_OFFSET_BASETYPE (t2),
1253 strict & ~COMPARE_REDECLARATION))
1254 return false;
1255 if (!same_type_p (TREE_TYPE (t1), TREE_TYPE (t2)))
1256 return false;
1257 break;
1258
1259 case REFERENCE_TYPE:
1260 if (TYPE_REF_IS_RVALUE (t1) != TYPE_REF_IS_RVALUE (t2))
1261 return false;
1262 /* fall through to checks for pointer types */
1263
1264 case POINTER_TYPE:
1265 if (TYPE_MODE (t1) != TYPE_MODE (t2)
1266 || TYPE_REF_CAN_ALIAS_ALL (t1) != TYPE_REF_CAN_ALIAS_ALL (t2)
1267 || !same_type_p (TREE_TYPE (t1), TREE_TYPE (t2)))
1268 return false;
1269 break;
1270
1271 case METHOD_TYPE:
1272 case FUNCTION_TYPE:
1273 if (!same_type_p (TREE_TYPE (t1), TREE_TYPE (t2)))
1274 return false;
1275 if (!compparms (TYPE_ARG_TYPES (t1), TYPE_ARG_TYPES (t2)))
1276 return false;
1277 break;
1278
1279 case ARRAY_TYPE:
1280 /* Target types must match incl. qualifiers. */
1281 if (!comp_array_types (t1, t2, !!(strict & COMPARE_REDECLARATION)))
1282 return false;
1283 break;
1284
1285 case TEMPLATE_TYPE_PARM:
1286 /* If T1 and T2 don't have the same relative position in their
1287 template parameters set, they can't be equal. */
1288 if (!comp_template_parms_position (t1, t2))
1289 return false;
1290 break;
1291
1292 case TYPENAME_TYPE:
1293 if (!cp_tree_equal (TYPENAME_TYPE_FULLNAME (t1),
1294 TYPENAME_TYPE_FULLNAME (t2)))
1295 return false;
1296 if (!same_type_p (TYPE_CONTEXT (t1), TYPE_CONTEXT (t2)))
1297 return false;
1298 break;
1299
1300 case UNBOUND_CLASS_TEMPLATE:
1301 if (!cp_tree_equal (TYPE_IDENTIFIER (t1), TYPE_IDENTIFIER (t2)))
1302 return false;
1303 if (!same_type_p (TYPE_CONTEXT (t1), TYPE_CONTEXT (t2)))
1304 return false;
1305 break;
1306
1307 case COMPLEX_TYPE:
1308 if (!same_type_p (TREE_TYPE (t1), TREE_TYPE (t2)))
1309 return false;
1310 break;
1311
1312 case VECTOR_TYPE:
1313 if (TYPE_VECTOR_SUBPARTS (t1) != TYPE_VECTOR_SUBPARTS (t2)
1314 || !same_type_p (TREE_TYPE (t1), TREE_TYPE (t2)))
1315 return false;
1316 break;
1317
1318 case TYPE_PACK_EXPANSION:
1319 return same_type_p (PACK_EXPANSION_PATTERN (t1),
1320 PACK_EXPANSION_PATTERN (t2));
1321
1322 case DECLTYPE_TYPE:
1323 if (DECLTYPE_TYPE_ID_EXPR_OR_MEMBER_ACCESS_P (t1)
1324 != DECLTYPE_TYPE_ID_EXPR_OR_MEMBER_ACCESS_P (t2)
1325 || (DECLTYPE_FOR_LAMBDA_CAPTURE (t1)
1326 != DECLTYPE_FOR_LAMBDA_CAPTURE (t2))
1327 || (DECLTYPE_FOR_LAMBDA_RETURN (t1)
1328 != DECLTYPE_FOR_LAMBDA_RETURN (t2))
1329 || !cp_tree_equal (DECLTYPE_TYPE_EXPR (t1),
1330 DECLTYPE_TYPE_EXPR (t2)))
1331 return false;
1332 break;
1333
1334 default:
1335 return false;
1336 }
1337
1338 /* If we get here, we know that from a target independent POV the
1339 types are the same. Make sure the target attributes are also
1340 the same. */
1341 return comp_type_attributes (t1, t2);
1342 }
1343
1344 /* Return true if T1 and T2 are related as allowed by STRICT. STRICT
1345 is a bitwise-or of the COMPARE_* flags. */
1346
1347 bool
1348 comptypes (tree t1, tree t2, int strict)
1349 {
1350 if (strict == COMPARE_STRICT)
1351 {
1352 if (t1 == t2)
1353 return true;
1354
1355 if (t1 == error_mark_node || t2 == error_mark_node)
1356 return false;
1357
1358 if (TYPE_STRUCTURAL_EQUALITY_P (t1) || TYPE_STRUCTURAL_EQUALITY_P (t2))
1359 /* At least one of the types requires structural equality, so
1360 perform a deep check. */
1361 return structural_comptypes (t1, t2, strict);
1362
1363 #ifdef ENABLE_CHECKING
1364 if (USE_CANONICAL_TYPES)
1365 {
1366 bool result = structural_comptypes (t1, t2, strict);
1367
1368 if (result && TYPE_CANONICAL (t1) != TYPE_CANONICAL (t2))
1369 /* The two types are structurally equivalent, but their
1370 canonical types were different. This is a failure of the
1371 canonical type propagation code.*/
1372 internal_error
1373 ("canonical types differ for identical types %T and %T",
1374 t1, t2);
1375 else if (!result && TYPE_CANONICAL (t1) == TYPE_CANONICAL (t2))
1376 /* Two types are structurally different, but the canonical
1377 types are the same. This means we were over-eager in
1378 assigning canonical types. */
1379 internal_error
1380 ("same canonical type node for different types %T and %T",
1381 t1, t2);
1382
1383 return result;
1384 }
1385 #else
1386 if (USE_CANONICAL_TYPES)
1387 return TYPE_CANONICAL (t1) == TYPE_CANONICAL (t2);
1388 #endif
1389 else
1390 return structural_comptypes (t1, t2, strict);
1391 }
1392 else if (strict == COMPARE_STRUCTURAL)
1393 return structural_comptypes (t1, t2, COMPARE_STRICT);
1394 else
1395 return structural_comptypes (t1, t2, strict);
1396 }
1397
1398 /* Returns nonzero iff TYPE1 and TYPE2 are the same type, ignoring
1399 top-level qualifiers. */
1400
1401 bool
1402 same_type_ignoring_top_level_qualifiers_p (tree type1, tree type2)
1403 {
1404 if (type1 == error_mark_node || type2 == error_mark_node)
1405 return false;
1406
1407 return same_type_p (TYPE_MAIN_VARIANT (type1), TYPE_MAIN_VARIANT (type2));
1408 }
1409
1410 /* Returns 1 if TYPE1 is at least as qualified as TYPE2. */
1411
1412 bool
1413 at_least_as_qualified_p (const_tree type1, const_tree type2)
1414 {
1415 int q1 = cp_type_quals (type1);
1416 int q2 = cp_type_quals (type2);
1417
1418 /* All qualifiers for TYPE2 must also appear in TYPE1. */
1419 return (q1 & q2) == q2;
1420 }
1421
1422 /* Returns 1 if TYPE1 is more cv-qualified than TYPE2, -1 if TYPE2 is
1423 more cv-qualified that TYPE1, and 0 otherwise. */
1424
1425 int
1426 comp_cv_qualification (const_tree type1, const_tree type2)
1427 {
1428 int q1 = cp_type_quals (type1);
1429 int q2 = cp_type_quals (type2);
1430
1431 if (q1 == q2)
1432 return 0;
1433
1434 if ((q1 & q2) == q2)
1435 return 1;
1436 else if ((q1 & q2) == q1)
1437 return -1;
1438
1439 return 0;
1440 }
1441
1442 /* Returns 1 if the cv-qualification signature of TYPE1 is a proper
1443 subset of the cv-qualification signature of TYPE2, and the types
1444 are similar. Returns -1 if the other way 'round, and 0 otherwise. */
1445
1446 int
1447 comp_cv_qual_signature (tree type1, tree type2)
1448 {
1449 if (comp_ptr_ttypes_real (type2, type1, -1))
1450 return 1;
1451 else if (comp_ptr_ttypes_real (type1, type2, -1))
1452 return -1;
1453 else
1454 return 0;
1455 }
1456 \f
1457 /* Subroutines of `comptypes'. */
1458
1459 /* Return true if two parameter type lists PARMS1 and PARMS2 are
1460 equivalent in the sense that functions with those parameter types
1461 can have equivalent types. The two lists must be equivalent,
1462 element by element. */
1463
1464 bool
1465 compparms (const_tree parms1, const_tree parms2)
1466 {
1467 const_tree t1, t2;
1468
1469 /* An unspecified parmlist matches any specified parmlist
1470 whose argument types don't need default promotions. */
1471
1472 for (t1 = parms1, t2 = parms2;
1473 t1 || t2;
1474 t1 = TREE_CHAIN (t1), t2 = TREE_CHAIN (t2))
1475 {
1476 /* If one parmlist is shorter than the other,
1477 they fail to match. */
1478 if (!t1 || !t2)
1479 return false;
1480 if (!same_type_p (TREE_VALUE (t1), TREE_VALUE (t2)))
1481 return false;
1482 }
1483 return true;
1484 }
1485
1486 \f
1487 /* Process a sizeof or alignof expression where the operand is a
1488 type. */
1489
1490 tree
1491 cxx_sizeof_or_alignof_type (tree type, enum tree_code op, bool complain)
1492 {
1493 tree value;
1494 bool dependent_p;
1495
1496 gcc_assert (op == SIZEOF_EXPR || op == ALIGNOF_EXPR);
1497 if (type == error_mark_node)
1498 return error_mark_node;
1499
1500 type = non_reference (type);
1501 if (TREE_CODE (type) == METHOD_TYPE)
1502 {
1503 if (complain)
1504 pedwarn (input_location, pedantic ? OPT_pedantic : OPT_Wpointer_arith,
1505 "invalid application of %qs to a member function",
1506 operator_name_info[(int) op].name);
1507 value = size_one_node;
1508 }
1509
1510 dependent_p = dependent_type_p (type);
1511 if (!dependent_p)
1512 complete_type (type);
1513 if (dependent_p
1514 /* VLA types will have a non-constant size. In the body of an
1515 uninstantiated template, we don't need to try to compute the
1516 value, because the sizeof expression is not an integral
1517 constant expression in that case. And, if we do try to
1518 compute the value, we'll likely end up with SAVE_EXPRs, which
1519 the template substitution machinery does not expect to see. */
1520 || (processing_template_decl
1521 && COMPLETE_TYPE_P (type)
1522 && TREE_CODE (TYPE_SIZE (type)) != INTEGER_CST))
1523 {
1524 value = build_min (op, size_type_node, type);
1525 TREE_READONLY (value) = 1;
1526 return value;
1527 }
1528
1529 return c_sizeof_or_alignof_type (input_location, complete_type (type),
1530 op == SIZEOF_EXPR,
1531 complain);
1532 }
1533
1534 /* Return the size of the type, without producing any warnings for
1535 types whose size cannot be taken. This routine should be used only
1536 in some other routine that has already produced a diagnostic about
1537 using the size of such a type. */
1538 tree
1539 cxx_sizeof_nowarn (tree type)
1540 {
1541 if (TREE_CODE (type) == FUNCTION_TYPE
1542 || TREE_CODE (type) == VOID_TYPE
1543 || TREE_CODE (type) == ERROR_MARK)
1544 return size_one_node;
1545 else if (!COMPLETE_TYPE_P (type))
1546 return size_zero_node;
1547 else
1548 return cxx_sizeof_or_alignof_type (type, SIZEOF_EXPR, false);
1549 }
1550
1551 /* Process a sizeof expression where the operand is an expression. */
1552
1553 static tree
1554 cxx_sizeof_expr (tree e, tsubst_flags_t complain)
1555 {
1556 if (e == error_mark_node)
1557 return error_mark_node;
1558
1559 if (processing_template_decl)
1560 {
1561 e = build_min (SIZEOF_EXPR, size_type_node, e);
1562 TREE_SIDE_EFFECTS (e) = 0;
1563 TREE_READONLY (e) = 1;
1564
1565 return e;
1566 }
1567
1568 /* To get the size of a static data member declared as an array of
1569 unknown bound, we need to instantiate it. */
1570 if (TREE_CODE (e) == VAR_DECL
1571 && VAR_HAD_UNKNOWN_BOUND (e)
1572 && DECL_TEMPLATE_INSTANTIATION (e))
1573 instantiate_decl (e, /*defer_ok*/true, /*expl_inst_mem*/false);
1574
1575 e = mark_type_use (e);
1576
1577 if (TREE_CODE (e) == COMPONENT_REF
1578 && TREE_CODE (TREE_OPERAND (e, 1)) == FIELD_DECL
1579 && DECL_C_BIT_FIELD (TREE_OPERAND (e, 1)))
1580 {
1581 if (complain & tf_error)
1582 error ("invalid application of %<sizeof%> to a bit-field");
1583 else
1584 return error_mark_node;
1585 e = char_type_node;
1586 }
1587 else if (is_overloaded_fn (e))
1588 {
1589 if (complain & tf_error)
1590 permerror (input_location, "ISO C++ forbids applying %<sizeof%> to an expression of "
1591 "function type");
1592 else
1593 return error_mark_node;
1594 e = char_type_node;
1595 }
1596 else if (type_unknown_p (e))
1597 {
1598 if (complain & tf_error)
1599 cxx_incomplete_type_error (e, TREE_TYPE (e));
1600 else
1601 return error_mark_node;
1602 e = char_type_node;
1603 }
1604 else
1605 e = TREE_TYPE (e);
1606
1607 return cxx_sizeof_or_alignof_type (e, SIZEOF_EXPR, complain & tf_error);
1608 }
1609
1610 /* Implement the __alignof keyword: Return the minimum required
1611 alignment of E, measured in bytes. For VAR_DECL's and
1612 FIELD_DECL's return DECL_ALIGN (which can be set from an
1613 "aligned" __attribute__ specification). */
1614
1615 static tree
1616 cxx_alignof_expr (tree e, tsubst_flags_t complain)
1617 {
1618 tree t;
1619
1620 if (e == error_mark_node)
1621 return error_mark_node;
1622
1623 if (processing_template_decl)
1624 {
1625 e = build_min (ALIGNOF_EXPR, size_type_node, e);
1626 TREE_SIDE_EFFECTS (e) = 0;
1627 TREE_READONLY (e) = 1;
1628
1629 return e;
1630 }
1631
1632 e = mark_type_use (e);
1633
1634 if (TREE_CODE (e) == VAR_DECL)
1635 t = size_int (DECL_ALIGN_UNIT (e));
1636 else if (TREE_CODE (e) == COMPONENT_REF
1637 && TREE_CODE (TREE_OPERAND (e, 1)) == FIELD_DECL
1638 && DECL_C_BIT_FIELD (TREE_OPERAND (e, 1)))
1639 {
1640 if (complain & tf_error)
1641 error ("invalid application of %<__alignof%> to a bit-field");
1642 else
1643 return error_mark_node;
1644 t = size_one_node;
1645 }
1646 else if (TREE_CODE (e) == COMPONENT_REF
1647 && TREE_CODE (TREE_OPERAND (e, 1)) == FIELD_DECL)
1648 t = size_int (DECL_ALIGN_UNIT (TREE_OPERAND (e, 1)));
1649 else if (is_overloaded_fn (e))
1650 {
1651 if (complain & tf_error)
1652 permerror (input_location, "ISO C++ forbids applying %<__alignof%> to an expression of "
1653 "function type");
1654 else
1655 return error_mark_node;
1656 if (TREE_CODE (e) == FUNCTION_DECL)
1657 t = size_int (DECL_ALIGN_UNIT (e));
1658 else
1659 t = size_one_node;
1660 }
1661 else if (type_unknown_p (e))
1662 {
1663 if (complain & tf_error)
1664 cxx_incomplete_type_error (e, TREE_TYPE (e));
1665 else
1666 return error_mark_node;
1667 t = size_one_node;
1668 }
1669 else
1670 return cxx_sizeof_or_alignof_type (TREE_TYPE (e), ALIGNOF_EXPR,
1671 complain & tf_error);
1672
1673 return fold_convert (size_type_node, t);
1674 }
1675
1676 /* Process a sizeof or alignof expression E with code OP where the operand
1677 is an expression. */
1678
1679 tree
1680 cxx_sizeof_or_alignof_expr (tree e, enum tree_code op, bool complain)
1681 {
1682 if (op == SIZEOF_EXPR)
1683 return cxx_sizeof_expr (e, complain? tf_warning_or_error : tf_none);
1684 else
1685 return cxx_alignof_expr (e, complain? tf_warning_or_error : tf_none);
1686 }
1687 \f
1688 /* EXPR is being used in a context that is not a function call.
1689 Enforce:
1690
1691 [expr.ref]
1692
1693 The expression can be used only as the left-hand operand of a
1694 member function call.
1695
1696 [expr.mptr.operator]
1697
1698 If the result of .* or ->* is a function, then that result can be
1699 used only as the operand for the function call operator ().
1700
1701 by issuing an error message if appropriate. Returns true iff EXPR
1702 violates these rules. */
1703
1704 bool
1705 invalid_nonstatic_memfn_p (const_tree expr, tsubst_flags_t complain)
1706 {
1707 if (expr && DECL_NONSTATIC_MEMBER_FUNCTION_P (expr))
1708 {
1709 if (complain & tf_error)
1710 error ("invalid use of non-static member function");
1711 return true;
1712 }
1713 return false;
1714 }
1715
1716 /* If EXP is a reference to a bitfield, and the type of EXP does not
1717 match the declared type of the bitfield, return the declared type
1718 of the bitfield. Otherwise, return NULL_TREE. */
1719
1720 tree
1721 is_bitfield_expr_with_lowered_type (const_tree exp)
1722 {
1723 switch (TREE_CODE (exp))
1724 {
1725 case COND_EXPR:
1726 if (!is_bitfield_expr_with_lowered_type (TREE_OPERAND (exp, 1)
1727 ? TREE_OPERAND (exp, 1)
1728 : TREE_OPERAND (exp, 0)))
1729 return NULL_TREE;
1730 return is_bitfield_expr_with_lowered_type (TREE_OPERAND (exp, 2));
1731
1732 case COMPOUND_EXPR:
1733 return is_bitfield_expr_with_lowered_type (TREE_OPERAND (exp, 1));
1734
1735 case MODIFY_EXPR:
1736 case SAVE_EXPR:
1737 return is_bitfield_expr_with_lowered_type (TREE_OPERAND (exp, 0));
1738
1739 case COMPONENT_REF:
1740 {
1741 tree field;
1742
1743 field = TREE_OPERAND (exp, 1);
1744 if (TREE_CODE (field) != FIELD_DECL || !DECL_BIT_FIELD_TYPE (field))
1745 return NULL_TREE;
1746 if (same_type_ignoring_top_level_qualifiers_p
1747 (TREE_TYPE (exp), DECL_BIT_FIELD_TYPE (field)))
1748 return NULL_TREE;
1749 return DECL_BIT_FIELD_TYPE (field);
1750 }
1751
1752 CASE_CONVERT:
1753 if (TYPE_MAIN_VARIANT (TREE_TYPE (TREE_OPERAND (exp, 0)))
1754 == TYPE_MAIN_VARIANT (TREE_TYPE (exp)))
1755 return is_bitfield_expr_with_lowered_type (TREE_OPERAND (exp, 0));
1756 /* Fallthrough. */
1757
1758 default:
1759 return NULL_TREE;
1760 }
1761 }
1762
1763 /* Like is_bitfield_with_lowered_type, except that if EXP is not a
1764 bitfield with a lowered type, the type of EXP is returned, rather
1765 than NULL_TREE. */
1766
1767 tree
1768 unlowered_expr_type (const_tree exp)
1769 {
1770 tree type;
1771 tree etype = TREE_TYPE (exp);
1772
1773 type = is_bitfield_expr_with_lowered_type (exp);
1774 if (type)
1775 type = cp_build_qualified_type (type, cp_type_quals (etype));
1776 else
1777 type = etype;
1778
1779 return type;
1780 }
1781
1782 /* Perform the conversions in [expr] that apply when an lvalue appears
1783 in an rvalue context: the lvalue-to-rvalue, array-to-pointer, and
1784 function-to-pointer conversions. In addition, manifest constants
1785 are replaced by their values, and bitfield references are converted
1786 to their declared types. Note that this function does not perform the
1787 lvalue-to-rvalue conversion for class types. If you need that conversion
1788 to for class types, then you probably need to use force_rvalue.
1789
1790 Although the returned value is being used as an rvalue, this
1791 function does not wrap the returned expression in a
1792 NON_LVALUE_EXPR; the caller is expected to be mindful of the fact
1793 that the return value is no longer an lvalue. */
1794
1795 tree
1796 decay_conversion (tree exp)
1797 {
1798 tree type;
1799 enum tree_code code;
1800
1801 type = TREE_TYPE (exp);
1802 if (type == error_mark_node)
1803 return error_mark_node;
1804
1805 exp = mark_rvalue_use (exp);
1806
1807 exp = resolve_nondeduced_context (exp);
1808 if (type_unknown_p (exp))
1809 {
1810 cxx_incomplete_type_error (exp, TREE_TYPE (exp));
1811 return error_mark_node;
1812 }
1813
1814 /* FIXME remove? at least need to remember that this isn't really a
1815 constant expression if EXP isn't decl_constant_var_p, like with
1816 C_MAYBE_CONST_EXPR. */
1817 exp = decl_constant_value (exp);
1818 if (error_operand_p (exp))
1819 return error_mark_node;
1820
1821 if (NULLPTR_TYPE_P (type))
1822 return nullptr_node;
1823
1824 /* build_c_cast puts on a NOP_EXPR to make the result not an lvalue.
1825 Leave such NOP_EXPRs, since RHS is being used in non-lvalue context. */
1826 code = TREE_CODE (type);
1827 if (code == VOID_TYPE)
1828 {
1829 error ("void value not ignored as it ought to be");
1830 return error_mark_node;
1831 }
1832 if (invalid_nonstatic_memfn_p (exp, tf_warning_or_error))
1833 return error_mark_node;
1834 if (code == FUNCTION_TYPE || is_overloaded_fn (exp))
1835 return cp_build_addr_expr (exp, tf_warning_or_error);
1836 if (code == ARRAY_TYPE)
1837 {
1838 tree adr;
1839 tree ptrtype;
1840
1841 if (TREE_CODE (exp) == INDIRECT_REF)
1842 return build_nop (build_pointer_type (TREE_TYPE (type)),
1843 TREE_OPERAND (exp, 0));
1844
1845 if (TREE_CODE (exp) == COMPOUND_EXPR)
1846 {
1847 tree op1 = decay_conversion (TREE_OPERAND (exp, 1));
1848 return build2 (COMPOUND_EXPR, TREE_TYPE (op1),
1849 TREE_OPERAND (exp, 0), op1);
1850 }
1851
1852 if (!lvalue_p (exp)
1853 && ! (TREE_CODE (exp) == CONSTRUCTOR && TREE_STATIC (exp)))
1854 {
1855 error ("invalid use of non-lvalue array");
1856 return error_mark_node;
1857 }
1858
1859 ptrtype = build_pointer_type (TREE_TYPE (type));
1860
1861 if (TREE_CODE (exp) == VAR_DECL)
1862 {
1863 if (!cxx_mark_addressable (exp))
1864 return error_mark_node;
1865 adr = build_nop (ptrtype, build_address (exp));
1866 return adr;
1867 }
1868 /* This way is better for a COMPONENT_REF since it can
1869 simplify the offset for a component. */
1870 adr = cp_build_addr_expr (exp, tf_warning_or_error);
1871 return cp_convert (ptrtype, adr);
1872 }
1873
1874 /* If a bitfield is used in a context where integral promotion
1875 applies, then the caller is expected to have used
1876 default_conversion. That function promotes bitfields correctly
1877 before calling this function. At this point, if we have a
1878 bitfield referenced, we may assume that is not subject to
1879 promotion, and that, therefore, the type of the resulting rvalue
1880 is the declared type of the bitfield. */
1881 exp = convert_bitfield_to_declared_type (exp);
1882
1883 /* We do not call rvalue() here because we do not want to wrap EXP
1884 in a NON_LVALUE_EXPR. */
1885
1886 /* [basic.lval]
1887
1888 Non-class rvalues always have cv-unqualified types. */
1889 type = TREE_TYPE (exp);
1890 if (!CLASS_TYPE_P (type) && cv_qualified_p (type))
1891 exp = build_nop (cv_unqualified (type), exp);
1892
1893 return exp;
1894 }
1895
1896 /* Perform preparatory conversions, as part of the "usual arithmetic
1897 conversions". In particular, as per [expr]:
1898
1899 Whenever an lvalue expression appears as an operand of an
1900 operator that expects the rvalue for that operand, the
1901 lvalue-to-rvalue, array-to-pointer, or function-to-pointer
1902 standard conversions are applied to convert the expression to an
1903 rvalue.
1904
1905 In addition, we perform integral promotions here, as those are
1906 applied to both operands to a binary operator before determining
1907 what additional conversions should apply. */
1908
1909 tree
1910 default_conversion (tree exp)
1911 {
1912 /* Check for target-specific promotions. */
1913 tree promoted_type = targetm.promoted_type (TREE_TYPE (exp));
1914 if (promoted_type)
1915 exp = cp_convert (promoted_type, exp);
1916 /* Perform the integral promotions first so that bitfield
1917 expressions (which may promote to "int", even if the bitfield is
1918 declared "unsigned") are promoted correctly. */
1919 else if (INTEGRAL_OR_UNSCOPED_ENUMERATION_TYPE_P (TREE_TYPE (exp)))
1920 exp = perform_integral_promotions (exp);
1921 /* Perform the other conversions. */
1922 exp = decay_conversion (exp);
1923
1924 return exp;
1925 }
1926
1927 /* EXPR is an expression with an integral or enumeration type.
1928 Perform the integral promotions in [conv.prom], and return the
1929 converted value. */
1930
1931 tree
1932 perform_integral_promotions (tree expr)
1933 {
1934 tree type;
1935 tree promoted_type;
1936
1937 expr = mark_rvalue_use (expr);
1938
1939 /* [conv.prom]
1940
1941 If the bitfield has an enumerated type, it is treated as any
1942 other value of that type for promotion purposes. */
1943 type = is_bitfield_expr_with_lowered_type (expr);
1944 if (!type || TREE_CODE (type) != ENUMERAL_TYPE)
1945 type = TREE_TYPE (expr);
1946 gcc_assert (INTEGRAL_OR_ENUMERATION_TYPE_P (type));
1947 promoted_type = type_promotes_to (type);
1948 if (type != promoted_type)
1949 expr = cp_convert (promoted_type, expr);
1950 return expr;
1951 }
1952
1953 /* Returns nonzero iff exp is a STRING_CST or the result of applying
1954 decay_conversion to one. */
1955
1956 int
1957 string_conv_p (const_tree totype, const_tree exp, int warn)
1958 {
1959 tree t;
1960
1961 if (TREE_CODE (totype) != POINTER_TYPE)
1962 return 0;
1963
1964 t = TREE_TYPE (totype);
1965 if (!same_type_p (t, char_type_node)
1966 && !same_type_p (t, char16_type_node)
1967 && !same_type_p (t, char32_type_node)
1968 && !same_type_p (t, wchar_type_node))
1969 return 0;
1970
1971 if (TREE_CODE (exp) == STRING_CST)
1972 {
1973 /* Make sure that we don't try to convert between char and wide chars. */
1974 if (!same_type_p (TYPE_MAIN_VARIANT (TREE_TYPE (TREE_TYPE (exp))), t))
1975 return 0;
1976 }
1977 else
1978 {
1979 /* Is this a string constant which has decayed to 'const char *'? */
1980 t = build_pointer_type (cp_build_qualified_type (t, TYPE_QUAL_CONST));
1981 if (!same_type_p (TREE_TYPE (exp), t))
1982 return 0;
1983 STRIP_NOPS (exp);
1984 if (TREE_CODE (exp) != ADDR_EXPR
1985 || TREE_CODE (TREE_OPERAND (exp, 0)) != STRING_CST)
1986 return 0;
1987 }
1988
1989 /* This warning is not very useful, as it complains about printf. */
1990 if (warn)
1991 warning (OPT_Wwrite_strings,
1992 "deprecated conversion from string constant to %qT",
1993 totype);
1994
1995 return 1;
1996 }
1997
1998 /* Given a COND_EXPR, MIN_EXPR, or MAX_EXPR in T, return it in a form that we
1999 can, for example, use as an lvalue. This code used to be in
2000 unary_complex_lvalue, but we needed it to deal with `a = (d == c) ? b : c'
2001 expressions, where we're dealing with aggregates. But now it's again only
2002 called from unary_complex_lvalue. The case (in particular) that led to
2003 this was with CODE == ADDR_EXPR, since it's not an lvalue when we'd
2004 get it there. */
2005
2006 static tree
2007 rationalize_conditional_expr (enum tree_code code, tree t,
2008 tsubst_flags_t complain)
2009 {
2010 /* For MIN_EXPR or MAX_EXPR, fold-const.c has arranged things so that
2011 the first operand is always the one to be used if both operands
2012 are equal, so we know what conditional expression this used to be. */
2013 if (TREE_CODE (t) == MIN_EXPR || TREE_CODE (t) == MAX_EXPR)
2014 {
2015 tree op0 = TREE_OPERAND (t, 0);
2016 tree op1 = TREE_OPERAND (t, 1);
2017
2018 /* The following code is incorrect if either operand side-effects. */
2019 gcc_assert (!TREE_SIDE_EFFECTS (op0)
2020 && !TREE_SIDE_EFFECTS (op1));
2021 return
2022 build_conditional_expr (build_x_binary_op ((TREE_CODE (t) == MIN_EXPR
2023 ? LE_EXPR : GE_EXPR),
2024 op0, TREE_CODE (op0),
2025 op1, TREE_CODE (op1),
2026 /*overloaded_p=*/NULL,
2027 complain),
2028 cp_build_unary_op (code, op0, 0, complain),
2029 cp_build_unary_op (code, op1, 0, complain),
2030 complain);
2031 }
2032
2033 return
2034 build_conditional_expr (TREE_OPERAND (t, 0),
2035 cp_build_unary_op (code, TREE_OPERAND (t, 1), 0,
2036 complain),
2037 cp_build_unary_op (code, TREE_OPERAND (t, 2), 0,
2038 complain),
2039 complain);
2040 }
2041
2042 /* Given the TYPE of an anonymous union field inside T, return the
2043 FIELD_DECL for the field. If not found return NULL_TREE. Because
2044 anonymous unions can nest, we must also search all anonymous unions
2045 that are directly reachable. */
2046
2047 tree
2048 lookup_anon_field (tree t, tree type)
2049 {
2050 tree field;
2051
2052 for (field = TYPE_FIELDS (t); field; field = DECL_CHAIN (field))
2053 {
2054 if (TREE_STATIC (field))
2055 continue;
2056 if (TREE_CODE (field) != FIELD_DECL || DECL_ARTIFICIAL (field))
2057 continue;
2058
2059 /* If we find it directly, return the field. */
2060 if (DECL_NAME (field) == NULL_TREE
2061 && type == TYPE_MAIN_VARIANT (TREE_TYPE (field)))
2062 {
2063 return field;
2064 }
2065
2066 /* Otherwise, it could be nested, search harder. */
2067 if (DECL_NAME (field) == NULL_TREE
2068 && ANON_AGGR_TYPE_P (TREE_TYPE (field)))
2069 {
2070 tree subfield = lookup_anon_field (TREE_TYPE (field), type);
2071 if (subfield)
2072 return subfield;
2073 }
2074 }
2075 return NULL_TREE;
2076 }
2077
2078 /* Build an expression representing OBJECT.MEMBER. OBJECT is an
2079 expression; MEMBER is a DECL or baselink. If ACCESS_PATH is
2080 non-NULL, it indicates the path to the base used to name MEMBER.
2081 If PRESERVE_REFERENCE is true, the expression returned will have
2082 REFERENCE_TYPE if the MEMBER does. Otherwise, the expression
2083 returned will have the type referred to by the reference.
2084
2085 This function does not perform access control; that is either done
2086 earlier by the parser when the name of MEMBER is resolved to MEMBER
2087 itself, or later when overload resolution selects one of the
2088 functions indicated by MEMBER. */
2089
2090 tree
2091 build_class_member_access_expr (tree object, tree member,
2092 tree access_path, bool preserve_reference,
2093 tsubst_flags_t complain)
2094 {
2095 tree object_type;
2096 tree member_scope;
2097 tree result = NULL_TREE;
2098
2099 if (error_operand_p (object) || error_operand_p (member))
2100 return error_mark_node;
2101
2102 gcc_assert (DECL_P (member) || BASELINK_P (member));
2103
2104 /* [expr.ref]
2105
2106 The type of the first expression shall be "class object" (of a
2107 complete type). */
2108 object_type = TREE_TYPE (object);
2109 if (!currently_open_class (object_type)
2110 && !complete_type_or_maybe_complain (object_type, object, complain))
2111 return error_mark_node;
2112 if (!CLASS_TYPE_P (object_type))
2113 {
2114 if (complain & tf_error)
2115 error ("request for member %qD in %qE, which is of non-class type %qT",
2116 member, object, object_type);
2117 return error_mark_node;
2118 }
2119
2120 /* The standard does not seem to actually say that MEMBER must be a
2121 member of OBJECT_TYPE. However, that is clearly what is
2122 intended. */
2123 if (DECL_P (member))
2124 {
2125 member_scope = DECL_CLASS_CONTEXT (member);
2126 mark_used (member);
2127 if (TREE_DEPRECATED (member))
2128 warn_deprecated_use (member, NULL_TREE);
2129 }
2130 else
2131 member_scope = BINFO_TYPE (BASELINK_ACCESS_BINFO (member));
2132 /* If MEMBER is from an anonymous aggregate, MEMBER_SCOPE will
2133 presently be the anonymous union. Go outwards until we find a
2134 type related to OBJECT_TYPE. */
2135 while (ANON_AGGR_TYPE_P (member_scope)
2136 && !same_type_ignoring_top_level_qualifiers_p (member_scope,
2137 object_type))
2138 member_scope = TYPE_CONTEXT (member_scope);
2139 if (!member_scope || !DERIVED_FROM_P (member_scope, object_type))
2140 {
2141 if (complain & tf_error)
2142 {
2143 if (TREE_CODE (member) == FIELD_DECL)
2144 error ("invalid use of nonstatic data member %qE", member);
2145 else
2146 error ("%qD is not a member of %qT", member, object_type);
2147 }
2148 return error_mark_node;
2149 }
2150
2151 /* Transform `(a, b).x' into `(*(a, &b)).x', `(a ? b : c).x' into
2152 `(*(a ? &b : &c)).x', and so on. A COND_EXPR is only an lvalue
2153 in the front end; only _DECLs and _REFs are lvalues in the back end. */
2154 {
2155 tree temp = unary_complex_lvalue (ADDR_EXPR, object);
2156 if (temp)
2157 object = cp_build_indirect_ref (temp, RO_NULL, complain);
2158 }
2159
2160 /* In [expr.ref], there is an explicit list of the valid choices for
2161 MEMBER. We check for each of those cases here. */
2162 if (TREE_CODE (member) == VAR_DECL)
2163 {
2164 /* A static data member. */
2165 result = member;
2166 mark_exp_read (object);
2167 /* If OBJECT has side-effects, they are supposed to occur. */
2168 if (TREE_SIDE_EFFECTS (object))
2169 result = build2 (COMPOUND_EXPR, TREE_TYPE (result), object, result);
2170 }
2171 else if (TREE_CODE (member) == FIELD_DECL)
2172 {
2173 /* A non-static data member. */
2174 bool null_object_p;
2175 int type_quals;
2176 tree member_type;
2177
2178 null_object_p = (TREE_CODE (object) == INDIRECT_REF
2179 && integer_zerop (TREE_OPERAND (object, 0)));
2180
2181 /* Convert OBJECT to the type of MEMBER. */
2182 if (!same_type_p (TYPE_MAIN_VARIANT (object_type),
2183 TYPE_MAIN_VARIANT (member_scope)))
2184 {
2185 tree binfo;
2186 base_kind kind;
2187
2188 binfo = lookup_base (access_path ? access_path : object_type,
2189 member_scope, ba_unique, &kind);
2190 if (binfo == error_mark_node)
2191 return error_mark_node;
2192
2193 /* It is invalid to try to get to a virtual base of a
2194 NULL object. The most common cause is invalid use of
2195 offsetof macro. */
2196 if (null_object_p && kind == bk_via_virtual)
2197 {
2198 if (complain & tf_error)
2199 {
2200 error ("invalid access to non-static data member %qD of "
2201 "NULL object",
2202 member);
2203 error ("(perhaps the %<offsetof%> macro was used incorrectly)");
2204 }
2205 return error_mark_node;
2206 }
2207
2208 /* Convert to the base. */
2209 object = build_base_path (PLUS_EXPR, object, binfo,
2210 /*nonnull=*/1);
2211 /* If we found the base successfully then we should be able
2212 to convert to it successfully. */
2213 gcc_assert (object != error_mark_node);
2214 }
2215
2216 /* Complain about other invalid uses of offsetof, even though they will
2217 give the right answer. Note that we complain whether or not they
2218 actually used the offsetof macro, since there's no way to know at this
2219 point. So we just give a warning, instead of a pedwarn. */
2220 /* Do not produce this warning for base class field references, because
2221 we know for a fact that didn't come from offsetof. This does occur
2222 in various testsuite cases where a null object is passed where a
2223 vtable access is required. */
2224 if (null_object_p && warn_invalid_offsetof
2225 && CLASSTYPE_NON_STD_LAYOUT (object_type)
2226 && !DECL_FIELD_IS_BASE (member)
2227 && cp_unevaluated_operand == 0
2228 && (complain & tf_warning))
2229 {
2230 warning (OPT_Winvalid_offsetof,
2231 "invalid access to non-static data member %qD "
2232 " of NULL object", member);
2233 warning (OPT_Winvalid_offsetof,
2234 "(perhaps the %<offsetof%> macro was used incorrectly)");
2235 }
2236
2237 /* If MEMBER is from an anonymous aggregate, we have converted
2238 OBJECT so that it refers to the class containing the
2239 anonymous union. Generate a reference to the anonymous union
2240 itself, and recur to find MEMBER. */
2241 if (ANON_AGGR_TYPE_P (DECL_CONTEXT (member))
2242 /* When this code is called from build_field_call, the
2243 object already has the type of the anonymous union.
2244 That is because the COMPONENT_REF was already
2245 constructed, and was then disassembled before calling
2246 build_field_call. After the function-call code is
2247 cleaned up, this waste can be eliminated. */
2248 && (!same_type_ignoring_top_level_qualifiers_p
2249 (TREE_TYPE (object), DECL_CONTEXT (member))))
2250 {
2251 tree anonymous_union;
2252
2253 anonymous_union = lookup_anon_field (TREE_TYPE (object),
2254 DECL_CONTEXT (member));
2255 object = build_class_member_access_expr (object,
2256 anonymous_union,
2257 /*access_path=*/NULL_TREE,
2258 preserve_reference,
2259 complain);
2260 }
2261
2262 /* Compute the type of the field, as described in [expr.ref]. */
2263 type_quals = TYPE_UNQUALIFIED;
2264 member_type = TREE_TYPE (member);
2265 if (TREE_CODE (member_type) != REFERENCE_TYPE)
2266 {
2267 type_quals = (cp_type_quals (member_type)
2268 | cp_type_quals (object_type));
2269
2270 /* A field is const (volatile) if the enclosing object, or the
2271 field itself, is const (volatile). But, a mutable field is
2272 not const, even within a const object. */
2273 if (DECL_MUTABLE_P (member))
2274 type_quals &= ~TYPE_QUAL_CONST;
2275 member_type = cp_build_qualified_type (member_type, type_quals);
2276 }
2277
2278 result = build3 (COMPONENT_REF, member_type, object, member,
2279 NULL_TREE);
2280 result = fold_if_not_in_template (result);
2281
2282 /* Mark the expression const or volatile, as appropriate. Even
2283 though we've dealt with the type above, we still have to mark the
2284 expression itself. */
2285 if (type_quals & TYPE_QUAL_CONST)
2286 TREE_READONLY (result) = 1;
2287 if (type_quals & TYPE_QUAL_VOLATILE)
2288 TREE_THIS_VOLATILE (result) = 1;
2289 }
2290 else if (BASELINK_P (member))
2291 {
2292 /* The member is a (possibly overloaded) member function. */
2293 tree functions;
2294 tree type;
2295
2296 /* If the MEMBER is exactly one static member function, then we
2297 know the type of the expression. Otherwise, we must wait
2298 until overload resolution has been performed. */
2299 functions = BASELINK_FUNCTIONS (member);
2300 if (TREE_CODE (functions) == FUNCTION_DECL
2301 && DECL_STATIC_FUNCTION_P (functions))
2302 type = TREE_TYPE (functions);
2303 else
2304 type = unknown_type_node;
2305 /* Note that we do not convert OBJECT to the BASELINK_BINFO
2306 base. That will happen when the function is called. */
2307 result = build3 (COMPONENT_REF, type, object, member, NULL_TREE);
2308 }
2309 else if (TREE_CODE (member) == CONST_DECL)
2310 {
2311 /* The member is an enumerator. */
2312 result = member;
2313 /* If OBJECT has side-effects, they are supposed to occur. */
2314 if (TREE_SIDE_EFFECTS (object))
2315 result = build2 (COMPOUND_EXPR, TREE_TYPE (result),
2316 object, result);
2317 }
2318 else
2319 {
2320 if (complain & tf_error)
2321 error ("invalid use of %qD", member);
2322 return error_mark_node;
2323 }
2324
2325 if (!preserve_reference)
2326 /* [expr.ref]
2327
2328 If E2 is declared to have type "reference to T", then ... the
2329 type of E1.E2 is T. */
2330 result = convert_from_reference (result);
2331
2332 return result;
2333 }
2334
2335 /* Return the destructor denoted by OBJECT.SCOPE::DTOR_NAME, or, if
2336 SCOPE is NULL, by OBJECT.DTOR_NAME, where DTOR_NAME is ~type. */
2337
2338 static tree
2339 lookup_destructor (tree object, tree scope, tree dtor_name)
2340 {
2341 tree object_type = TREE_TYPE (object);
2342 tree dtor_type = TREE_OPERAND (dtor_name, 0);
2343 tree expr;
2344
2345 if (scope && !check_dtor_name (scope, dtor_type))
2346 {
2347 error ("qualified type %qT does not match destructor name ~%qT",
2348 scope, dtor_type);
2349 return error_mark_node;
2350 }
2351 if (TREE_CODE (dtor_type) == IDENTIFIER_NODE)
2352 {
2353 /* In a template, names we can't find a match for are still accepted
2354 destructor names, and we check them here. */
2355 if (check_dtor_name (object_type, dtor_type))
2356 dtor_type = object_type;
2357 else
2358 {
2359 error ("object type %qT does not match destructor name ~%qT",
2360 object_type, dtor_type);
2361 return error_mark_node;
2362 }
2363
2364 }
2365 else if (!DERIVED_FROM_P (dtor_type, TYPE_MAIN_VARIANT (object_type)))
2366 {
2367 error ("the type being destroyed is %qT, but the destructor refers to %qT",
2368 TYPE_MAIN_VARIANT (object_type), dtor_type);
2369 return error_mark_node;
2370 }
2371 expr = lookup_member (dtor_type, complete_dtor_identifier,
2372 /*protect=*/1, /*want_type=*/false);
2373 expr = (adjust_result_of_qualified_name_lookup
2374 (expr, dtor_type, object_type));
2375 return expr;
2376 }
2377
2378 /* An expression of the form "A::template B" has been resolved to
2379 DECL. Issue a diagnostic if B is not a template or template
2380 specialization. */
2381
2382 void
2383 check_template_keyword (tree decl)
2384 {
2385 /* The standard says:
2386
2387 [temp.names]
2388
2389 If a name prefixed by the keyword template is not a member
2390 template, the program is ill-formed.
2391
2392 DR 228 removed the restriction that the template be a member
2393 template.
2394
2395 DR 96, if accepted would add the further restriction that explicit
2396 template arguments must be provided if the template keyword is
2397 used, but, as of 2005-10-16, that DR is still in "drafting". If
2398 this DR is accepted, then the semantic checks here can be
2399 simplified, as the entity named must in fact be a template
2400 specialization, rather than, as at present, a set of overloaded
2401 functions containing at least one template function. */
2402 if (TREE_CODE (decl) != TEMPLATE_DECL
2403 && TREE_CODE (decl) != TEMPLATE_ID_EXPR)
2404 {
2405 if (!is_overloaded_fn (decl))
2406 permerror (input_location, "%qD is not a template", decl);
2407 else
2408 {
2409 tree fns;
2410 fns = decl;
2411 if (BASELINK_P (fns))
2412 fns = BASELINK_FUNCTIONS (fns);
2413 while (fns)
2414 {
2415 tree fn = OVL_CURRENT (fns);
2416 if (TREE_CODE (fn) == TEMPLATE_DECL
2417 || TREE_CODE (fn) == TEMPLATE_ID_EXPR)
2418 break;
2419 if (TREE_CODE (fn) == FUNCTION_DECL
2420 && DECL_USE_TEMPLATE (fn)
2421 && PRIMARY_TEMPLATE_P (DECL_TI_TEMPLATE (fn)))
2422 break;
2423 fns = OVL_NEXT (fns);
2424 }
2425 if (!fns)
2426 permerror (input_location, "%qD is not a template", decl);
2427 }
2428 }
2429 }
2430
2431 /* This function is called by the parser to process a class member
2432 access expression of the form OBJECT.NAME. NAME is a node used by
2433 the parser to represent a name; it is not yet a DECL. It may,
2434 however, be a BASELINK where the BASELINK_FUNCTIONS is a
2435 TEMPLATE_ID_EXPR. Templates must be looked up by the parser, and
2436 there is no reason to do the lookup twice, so the parser keeps the
2437 BASELINK. TEMPLATE_P is true iff NAME was explicitly declared to
2438 be a template via the use of the "A::template B" syntax. */
2439
2440 tree
2441 finish_class_member_access_expr (tree object, tree name, bool template_p,
2442 tsubst_flags_t complain)
2443 {
2444 tree expr;
2445 tree object_type;
2446 tree member;
2447 tree access_path = NULL_TREE;
2448 tree orig_object = object;
2449 tree orig_name = name;
2450
2451 if (object == error_mark_node || name == error_mark_node)
2452 return error_mark_node;
2453
2454 /* If OBJECT is an ObjC class instance, we must obey ObjC access rules. */
2455 if (!objc_is_public (object, name))
2456 return error_mark_node;
2457
2458 object_type = TREE_TYPE (object);
2459
2460 if (processing_template_decl)
2461 {
2462 if (/* If OBJECT_TYPE is dependent, so is OBJECT.NAME. */
2463 dependent_type_p (object_type)
2464 /* If NAME is just an IDENTIFIER_NODE, then the expression
2465 is dependent. */
2466 || TREE_CODE (object) == IDENTIFIER_NODE
2467 /* If NAME is "f<args>", where either 'f' or 'args' is
2468 dependent, then the expression is dependent. */
2469 || (TREE_CODE (name) == TEMPLATE_ID_EXPR
2470 && dependent_template_id_p (TREE_OPERAND (name, 0),
2471 TREE_OPERAND (name, 1)))
2472 /* If NAME is "T::X" where "T" is dependent, then the
2473 expression is dependent. */
2474 || (TREE_CODE (name) == SCOPE_REF
2475 && TYPE_P (TREE_OPERAND (name, 0))
2476 && dependent_type_p (TREE_OPERAND (name, 0))))
2477 return build_min_nt (COMPONENT_REF, object, name, NULL_TREE);
2478 object = build_non_dependent_expr (object);
2479 }
2480 else if (c_dialect_objc ()
2481 && TREE_CODE (name) == IDENTIFIER_NODE
2482 && (expr = objc_maybe_build_component_ref (object, name)))
2483 return expr;
2484
2485 /* [expr.ref]
2486
2487 The type of the first expression shall be "class object" (of a
2488 complete type). */
2489 if (!currently_open_class (object_type)
2490 && !complete_type_or_maybe_complain (object_type, object, complain))
2491 return error_mark_node;
2492 if (!CLASS_TYPE_P (object_type))
2493 {
2494 if (complain & tf_error)
2495 error ("request for member %qD in %qE, which is of non-class type %qT",
2496 name, object, object_type);
2497 return error_mark_node;
2498 }
2499
2500 if (BASELINK_P (name))
2501 /* A member function that has already been looked up. */
2502 member = name;
2503 else
2504 {
2505 bool is_template_id = false;
2506 tree template_args = NULL_TREE;
2507 tree scope;
2508
2509 if (TREE_CODE (name) == TEMPLATE_ID_EXPR)
2510 {
2511 is_template_id = true;
2512 template_args = TREE_OPERAND (name, 1);
2513 name = TREE_OPERAND (name, 0);
2514
2515 if (TREE_CODE (name) == OVERLOAD)
2516 name = DECL_NAME (get_first_fn (name));
2517 else if (DECL_P (name))
2518 name = DECL_NAME (name);
2519 }
2520
2521 if (TREE_CODE (name) == SCOPE_REF)
2522 {
2523 /* A qualified name. The qualifying class or namespace `S'
2524 has already been looked up; it is either a TYPE or a
2525 NAMESPACE_DECL. */
2526 scope = TREE_OPERAND (name, 0);
2527 name = TREE_OPERAND (name, 1);
2528
2529 /* If SCOPE is a namespace, then the qualified name does not
2530 name a member of OBJECT_TYPE. */
2531 if (TREE_CODE (scope) == NAMESPACE_DECL)
2532 {
2533 if (complain & tf_error)
2534 error ("%<%D::%D%> is not a member of %qT",
2535 scope, name, object_type);
2536 return error_mark_node;
2537 }
2538
2539 gcc_assert (CLASS_TYPE_P (scope));
2540 gcc_assert (TREE_CODE (name) == IDENTIFIER_NODE
2541 || TREE_CODE (name) == BIT_NOT_EXPR);
2542
2543 if (constructor_name_p (name, scope))
2544 {
2545 if (complain & tf_error)
2546 error ("cannot call constructor %<%T::%D%> directly",
2547 scope, name);
2548 return error_mark_node;
2549 }
2550
2551 /* Find the base of OBJECT_TYPE corresponding to SCOPE. */
2552 access_path = lookup_base (object_type, scope, ba_check, NULL);
2553 if (access_path == error_mark_node)
2554 return error_mark_node;
2555 if (!access_path)
2556 {
2557 if (complain & tf_error)
2558 error ("%qT is not a base of %qT", scope, object_type);
2559 return error_mark_node;
2560 }
2561 }
2562 else
2563 {
2564 scope = NULL_TREE;
2565 access_path = object_type;
2566 }
2567
2568 if (TREE_CODE (name) == BIT_NOT_EXPR)
2569 member = lookup_destructor (object, scope, name);
2570 else
2571 {
2572 /* Look up the member. */
2573 member = lookup_member (access_path, name, /*protect=*/1,
2574 /*want_type=*/false);
2575 if (member == NULL_TREE)
2576 {
2577 if (complain & tf_error)
2578 error ("%qD has no member named %qE", object_type, name);
2579 return error_mark_node;
2580 }
2581 if (member == error_mark_node)
2582 return error_mark_node;
2583 }
2584
2585 if (is_template_id)
2586 {
2587 tree templ = member;
2588
2589 if (BASELINK_P (templ))
2590 templ = lookup_template_function (templ, template_args);
2591 else
2592 {
2593 if (complain & tf_error)
2594 error ("%qD is not a member template function", name);
2595 return error_mark_node;
2596 }
2597 }
2598 }
2599
2600 if (TREE_DEPRECATED (member))
2601 warn_deprecated_use (member, NULL_TREE);
2602
2603 if (template_p)
2604 check_template_keyword (member);
2605
2606 expr = build_class_member_access_expr (object, member, access_path,
2607 /*preserve_reference=*/false,
2608 complain);
2609 if (processing_template_decl && expr != error_mark_node)
2610 {
2611 if (BASELINK_P (member))
2612 {
2613 if (TREE_CODE (orig_name) == SCOPE_REF)
2614 BASELINK_QUALIFIED_P (member) = 1;
2615 orig_name = member;
2616 }
2617 return build_min_non_dep (COMPONENT_REF, expr,
2618 orig_object, orig_name,
2619 NULL_TREE);
2620 }
2621
2622 return expr;
2623 }
2624
2625 /* Return an expression for the MEMBER_NAME field in the internal
2626 representation of PTRMEM, a pointer-to-member function. (Each
2627 pointer-to-member function type gets its own RECORD_TYPE so it is
2628 more convenient to access the fields by name than by FIELD_DECL.)
2629 This routine converts the NAME to a FIELD_DECL and then creates the
2630 node for the complete expression. */
2631
2632 tree
2633 build_ptrmemfunc_access_expr (tree ptrmem, tree member_name)
2634 {
2635 tree ptrmem_type;
2636 tree member;
2637 tree member_type;
2638
2639 /* This code is a stripped down version of
2640 build_class_member_access_expr. It does not work to use that
2641 routine directly because it expects the object to be of class
2642 type. */
2643 ptrmem_type = TREE_TYPE (ptrmem);
2644 gcc_assert (TYPE_PTRMEMFUNC_P (ptrmem_type));
2645 member = lookup_member (ptrmem_type, member_name, /*protect=*/0,
2646 /*want_type=*/false);
2647 member_type = cp_build_qualified_type (TREE_TYPE (member),
2648 cp_type_quals (ptrmem_type));
2649 return fold_build3_loc (input_location,
2650 COMPONENT_REF, member_type,
2651 ptrmem, member, NULL_TREE);
2652 }
2653
2654 /* Given an expression PTR for a pointer, return an expression
2655 for the value pointed to.
2656 ERRORSTRING is the name of the operator to appear in error messages.
2657
2658 This function may need to overload OPERATOR_FNNAME.
2659 Must also handle REFERENCE_TYPEs for C++. */
2660
2661 tree
2662 build_x_indirect_ref (tree expr, ref_operator errorstring,
2663 tsubst_flags_t complain)
2664 {
2665 tree orig_expr = expr;
2666 tree rval;
2667
2668 if (processing_template_decl)
2669 {
2670 /* Retain the type if we know the operand is a pointer so that
2671 describable_type doesn't make auto deduction break. */
2672 if (TREE_TYPE (expr) && POINTER_TYPE_P (TREE_TYPE (expr)))
2673 return build_min (INDIRECT_REF, TREE_TYPE (TREE_TYPE (expr)), expr);
2674 if (type_dependent_expression_p (expr))
2675 return build_min_nt (INDIRECT_REF, expr);
2676 expr = build_non_dependent_expr (expr);
2677 }
2678
2679 rval = build_new_op (INDIRECT_REF, LOOKUP_NORMAL, expr, NULL_TREE,
2680 NULL_TREE, /*overloaded_p=*/NULL, complain);
2681 if (!rval)
2682 rval = cp_build_indirect_ref (expr, errorstring, complain);
2683
2684 if (processing_template_decl && rval != error_mark_node)
2685 return build_min_non_dep (INDIRECT_REF, rval, orig_expr);
2686 else
2687 return rval;
2688 }
2689
2690 /* Helper function called from c-common. */
2691 tree
2692 build_indirect_ref (location_t loc __attribute__ ((__unused__)),
2693 tree ptr, ref_operator errorstring)
2694 {
2695 return cp_build_indirect_ref (ptr, errorstring, tf_warning_or_error);
2696 }
2697
2698 tree
2699 cp_build_indirect_ref (tree ptr, ref_operator errorstring,
2700 tsubst_flags_t complain)
2701 {
2702 tree pointer, type;
2703
2704 if (ptr == error_mark_node)
2705 return error_mark_node;
2706
2707 if (ptr == current_class_ptr)
2708 return current_class_ref;
2709
2710 pointer = (TREE_CODE (TREE_TYPE (ptr)) == REFERENCE_TYPE
2711 ? ptr : decay_conversion (ptr));
2712 type = TREE_TYPE (pointer);
2713
2714 if (POINTER_TYPE_P (type))
2715 {
2716 /* [expr.unary.op]
2717
2718 If the type of the expression is "pointer to T," the type
2719 of the result is "T." */
2720 tree t = TREE_TYPE (type);
2721
2722 if (CONVERT_EXPR_P (ptr)
2723 || TREE_CODE (ptr) == VIEW_CONVERT_EXPR)
2724 {
2725 /* If a warning is issued, mark it to avoid duplicates from
2726 the backend. This only needs to be done at
2727 warn_strict_aliasing > 2. */
2728 if (warn_strict_aliasing > 2)
2729 if (strict_aliasing_warning (TREE_TYPE (TREE_OPERAND (ptr, 0)),
2730 type, TREE_OPERAND (ptr, 0)))
2731 TREE_NO_WARNING (ptr) = 1;
2732 }
2733
2734 if (VOID_TYPE_P (t))
2735 {
2736 /* A pointer to incomplete type (other than cv void) can be
2737 dereferenced [expr.unary.op]/1 */
2738 if (complain & tf_error)
2739 error ("%qT is not a pointer-to-object type", type);
2740 return error_mark_node;
2741 }
2742 else if (TREE_CODE (pointer) == ADDR_EXPR
2743 && same_type_p (t, TREE_TYPE (TREE_OPERAND (pointer, 0))))
2744 /* The POINTER was something like `&x'. We simplify `*&x' to
2745 `x'. */
2746 return TREE_OPERAND (pointer, 0);
2747 else
2748 {
2749 tree ref = build1 (INDIRECT_REF, t, pointer);
2750
2751 /* We *must* set TREE_READONLY when dereferencing a pointer to const,
2752 so that we get the proper error message if the result is used
2753 to assign to. Also, &* is supposed to be a no-op. */
2754 TREE_READONLY (ref) = CP_TYPE_CONST_P (t);
2755 TREE_THIS_VOLATILE (ref) = CP_TYPE_VOLATILE_P (t);
2756 TREE_SIDE_EFFECTS (ref)
2757 = (TREE_THIS_VOLATILE (ref) || TREE_SIDE_EFFECTS (pointer));
2758 return ref;
2759 }
2760 }
2761 else if (!(complain & tf_error))
2762 /* Don't emit any errors; we'll just return ERROR_MARK_NODE later. */
2763 ;
2764 /* `pointer' won't be an error_mark_node if we were given a
2765 pointer to member, so it's cool to check for this here. */
2766 else if (TYPE_PTR_TO_MEMBER_P (type))
2767 switch (errorstring)
2768 {
2769 case RO_ARRAY_INDEXING:
2770 error ("invalid use of array indexing on pointer to member");
2771 break;
2772 case RO_UNARY_STAR:
2773 error ("invalid use of unary %<*%> on pointer to member");
2774 break;
2775 case RO_IMPLICIT_CONVERSION:
2776 error ("invalid use of implicit conversion on pointer to member");
2777 break;
2778 default:
2779 gcc_unreachable ();
2780 }
2781 else if (pointer != error_mark_node)
2782 invalid_indirection_error (input_location, type, errorstring);
2783
2784 return error_mark_node;
2785 }
2786
2787 /* This handles expressions of the form "a[i]", which denotes
2788 an array reference.
2789
2790 This is logically equivalent in C to *(a+i), but we may do it differently.
2791 If A is a variable or a member, we generate a primitive ARRAY_REF.
2792 This avoids forcing the array out of registers, and can work on
2793 arrays that are not lvalues (for example, members of structures returned
2794 by functions).
2795
2796 If INDEX is of some user-defined type, it must be converted to
2797 integer type. Otherwise, to make a compatible PLUS_EXPR, it
2798 will inherit the type of the array, which will be some pointer type.
2799
2800 LOC is the location to use in building the array reference. */
2801
2802 tree
2803 cp_build_array_ref (location_t loc, tree array, tree idx,
2804 tsubst_flags_t complain)
2805 {
2806 tree ret;
2807
2808 if (idx == 0)
2809 {
2810 if (complain & tf_error)
2811 error_at (loc, "subscript missing in array reference");
2812 return error_mark_node;
2813 }
2814
2815 if (TREE_TYPE (array) == error_mark_node
2816 || TREE_TYPE (idx) == error_mark_node)
2817 return error_mark_node;
2818
2819 /* If ARRAY is a COMPOUND_EXPR or COND_EXPR, move our reference
2820 inside it. */
2821 switch (TREE_CODE (array))
2822 {
2823 case COMPOUND_EXPR:
2824 {
2825 tree value = cp_build_array_ref (loc, TREE_OPERAND (array, 1), idx,
2826 complain);
2827 ret = build2 (COMPOUND_EXPR, TREE_TYPE (value),
2828 TREE_OPERAND (array, 0), value);
2829 SET_EXPR_LOCATION (ret, loc);
2830 return ret;
2831 }
2832
2833 case COND_EXPR:
2834 ret = build_conditional_expr
2835 (TREE_OPERAND (array, 0),
2836 cp_build_array_ref (loc, TREE_OPERAND (array, 1), idx,
2837 complain),
2838 cp_build_array_ref (loc, TREE_OPERAND (array, 2), idx,
2839 complain),
2840 tf_warning_or_error);
2841 protected_set_expr_location (ret, loc);
2842 return ret;
2843
2844 default:
2845 break;
2846 }
2847
2848 if (TREE_CODE (TREE_TYPE (array)) == ARRAY_TYPE)
2849 {
2850 tree rval, type;
2851
2852 warn_array_subscript_with_type_char (idx);
2853
2854 if (!INTEGRAL_OR_UNSCOPED_ENUMERATION_TYPE_P (TREE_TYPE (idx)))
2855 {
2856 if (complain & tf_error)
2857 error_at (loc, "array subscript is not an integer");
2858 return error_mark_node;
2859 }
2860
2861 /* Apply integral promotions *after* noticing character types.
2862 (It is unclear why we do these promotions -- the standard
2863 does not say that we should. In fact, the natural thing would
2864 seem to be to convert IDX to ptrdiff_t; we're performing
2865 pointer arithmetic.) */
2866 idx = perform_integral_promotions (idx);
2867
2868 /* An array that is indexed by a non-constant
2869 cannot be stored in a register; we must be able to do
2870 address arithmetic on its address.
2871 Likewise an array of elements of variable size. */
2872 if (TREE_CODE (idx) != INTEGER_CST
2873 || (COMPLETE_TYPE_P (TREE_TYPE (TREE_TYPE (array)))
2874 && (TREE_CODE (TYPE_SIZE (TREE_TYPE (TREE_TYPE (array))))
2875 != INTEGER_CST)))
2876 {
2877 if (!cxx_mark_addressable (array))
2878 return error_mark_node;
2879 }
2880
2881 /* An array that is indexed by a constant value which is not within
2882 the array bounds cannot be stored in a register either; because we
2883 would get a crash in store_bit_field/extract_bit_field when trying
2884 to access a non-existent part of the register. */
2885 if (TREE_CODE (idx) == INTEGER_CST
2886 && TYPE_DOMAIN (TREE_TYPE (array))
2887 && ! int_fits_type_p (idx, TYPE_DOMAIN (TREE_TYPE (array))))
2888 {
2889 if (!cxx_mark_addressable (array))
2890 return error_mark_node;
2891 }
2892
2893 if (!lvalue_p (array) && (complain & tf_error))
2894 pedwarn (loc, OPT_pedantic,
2895 "ISO C++ forbids subscripting non-lvalue array");
2896
2897 /* Note in C++ it is valid to subscript a `register' array, since
2898 it is valid to take the address of something with that
2899 storage specification. */
2900 if (extra_warnings)
2901 {
2902 tree foo = array;
2903 while (TREE_CODE (foo) == COMPONENT_REF)
2904 foo = TREE_OPERAND (foo, 0);
2905 if (TREE_CODE (foo) == VAR_DECL && DECL_REGISTER (foo)
2906 && (complain & tf_warning))
2907 warning_at (loc, OPT_Wextra,
2908 "subscripting array declared %<register%>");
2909 }
2910
2911 type = TREE_TYPE (TREE_TYPE (array));
2912 rval = build4 (ARRAY_REF, type, array, idx, NULL_TREE, NULL_TREE);
2913 /* Array ref is const/volatile if the array elements are
2914 or if the array is.. */
2915 TREE_READONLY (rval)
2916 |= (CP_TYPE_CONST_P (type) | TREE_READONLY (array));
2917 TREE_SIDE_EFFECTS (rval)
2918 |= (CP_TYPE_VOLATILE_P (type) | TREE_SIDE_EFFECTS (array));
2919 TREE_THIS_VOLATILE (rval)
2920 |= (CP_TYPE_VOLATILE_P (type) | TREE_THIS_VOLATILE (array));
2921 ret = require_complete_type_sfinae (fold_if_not_in_template (rval),
2922 complain);
2923 protected_set_expr_location (ret, loc);
2924 return ret;
2925 }
2926
2927 {
2928 tree ar = default_conversion (array);
2929 tree ind = default_conversion (idx);
2930
2931 /* Put the integer in IND to simplify error checking. */
2932 if (TREE_CODE (TREE_TYPE (ar)) == INTEGER_TYPE)
2933 {
2934 tree temp = ar;
2935 ar = ind;
2936 ind = temp;
2937 }
2938
2939 if (ar == error_mark_node)
2940 return ar;
2941
2942 if (TREE_CODE (TREE_TYPE (ar)) != POINTER_TYPE)
2943 {
2944 if (complain & tf_error)
2945 error_at (loc, "subscripted value is neither array nor pointer");
2946 return error_mark_node;
2947 }
2948 if (TREE_CODE (TREE_TYPE (ind)) != INTEGER_TYPE)
2949 {
2950 if (complain & tf_error)
2951 error_at (loc, "array subscript is not an integer");
2952 return error_mark_node;
2953 }
2954
2955 warn_array_subscript_with_type_char (idx);
2956
2957 ret = cp_build_indirect_ref (cp_build_binary_op (input_location,
2958 PLUS_EXPR, ar, ind,
2959 complain),
2960 RO_ARRAY_INDEXING,
2961 complain);
2962 protected_set_expr_location (ret, loc);
2963 return ret;
2964 }
2965 }
2966
2967 /* Entry point for Obj-C++. */
2968
2969 tree
2970 build_array_ref (location_t loc, tree array, tree idx)
2971 {
2972 return cp_build_array_ref (loc, array, idx, tf_warning_or_error);
2973 }
2974 \f
2975 /* Resolve a pointer to member function. INSTANCE is the object
2976 instance to use, if the member points to a virtual member.
2977
2978 This used to avoid checking for virtual functions if basetype
2979 has no virtual functions, according to an earlier ANSI draft.
2980 With the final ISO C++ rules, such an optimization is
2981 incorrect: A pointer to a derived member can be static_cast
2982 to pointer-to-base-member, as long as the dynamic object
2983 later has the right member. */
2984
2985 tree
2986 get_member_function_from_ptrfunc (tree *instance_ptrptr, tree function)
2987 {
2988 if (TREE_CODE (function) == OFFSET_REF)
2989 function = TREE_OPERAND (function, 1);
2990
2991 if (TYPE_PTRMEMFUNC_P (TREE_TYPE (function)))
2992 {
2993 tree idx, delta, e1, e2, e3, vtbl, basetype;
2994 tree fntype = TYPE_PTRMEMFUNC_FN_TYPE (TREE_TYPE (function));
2995
2996 tree instance_ptr = *instance_ptrptr;
2997 tree instance_save_expr = 0;
2998 if (instance_ptr == error_mark_node)
2999 {
3000 if (TREE_CODE (function) == PTRMEM_CST)
3001 {
3002 /* Extracting the function address from a pmf is only
3003 allowed with -Wno-pmf-conversions. It only works for
3004 pmf constants. */
3005 e1 = build_addr_func (PTRMEM_CST_MEMBER (function));
3006 e1 = convert (fntype, e1);
3007 return e1;
3008 }
3009 else
3010 {
3011 error ("object missing in use of %qE", function);
3012 return error_mark_node;
3013 }
3014 }
3015
3016 if (TREE_SIDE_EFFECTS (instance_ptr))
3017 instance_ptr = instance_save_expr = save_expr (instance_ptr);
3018
3019 if (TREE_SIDE_EFFECTS (function))
3020 function = save_expr (function);
3021
3022 /* Start by extracting all the information from the PMF itself. */
3023 e3 = pfn_from_ptrmemfunc (function);
3024 delta = delta_from_ptrmemfunc (function);
3025 idx = build1 (NOP_EXPR, vtable_index_type, e3);
3026 switch (TARGET_PTRMEMFUNC_VBIT_LOCATION)
3027 {
3028 case ptrmemfunc_vbit_in_pfn:
3029 e1 = cp_build_binary_op (input_location,
3030 BIT_AND_EXPR, idx, integer_one_node,
3031 tf_warning_or_error);
3032 idx = cp_build_binary_op (input_location,
3033 MINUS_EXPR, idx, integer_one_node,
3034 tf_warning_or_error);
3035 break;
3036
3037 case ptrmemfunc_vbit_in_delta:
3038 e1 = cp_build_binary_op (input_location,
3039 BIT_AND_EXPR, delta, integer_one_node,
3040 tf_warning_or_error);
3041 delta = cp_build_binary_op (input_location,
3042 RSHIFT_EXPR, delta, integer_one_node,
3043 tf_warning_or_error);
3044 break;
3045
3046 default:
3047 gcc_unreachable ();
3048 }
3049
3050 /* Convert down to the right base before using the instance. A
3051 special case is that in a pointer to member of class C, C may
3052 be incomplete. In that case, the function will of course be
3053 a member of C, and no conversion is required. In fact,
3054 lookup_base will fail in that case, because incomplete
3055 classes do not have BINFOs. */
3056 basetype = TYPE_METHOD_BASETYPE (TREE_TYPE (fntype));
3057 if (!same_type_ignoring_top_level_qualifiers_p
3058 (basetype, TREE_TYPE (TREE_TYPE (instance_ptr))))
3059 {
3060 basetype = lookup_base (TREE_TYPE (TREE_TYPE (instance_ptr)),
3061 basetype, ba_check, NULL);
3062 instance_ptr = build_base_path (PLUS_EXPR, instance_ptr, basetype,
3063 1);
3064 if (instance_ptr == error_mark_node)
3065 return error_mark_node;
3066 }
3067 /* ...and then the delta in the PMF. */
3068 instance_ptr = build2 (POINTER_PLUS_EXPR, TREE_TYPE (instance_ptr),
3069 instance_ptr, fold_convert (sizetype, delta));
3070
3071 /* Hand back the adjusted 'this' argument to our caller. */
3072 *instance_ptrptr = instance_ptr;
3073
3074 /* Next extract the vtable pointer from the object. */
3075 vtbl = build1 (NOP_EXPR, build_pointer_type (vtbl_ptr_type_node),
3076 instance_ptr);
3077 vtbl = cp_build_indirect_ref (vtbl, RO_NULL, tf_warning_or_error);
3078 /* If the object is not dynamic the access invokes undefined
3079 behavior. As it is not executed in this case silence the
3080 spurious warnings it may provoke. */
3081 TREE_NO_WARNING (vtbl) = 1;
3082
3083 /* Finally, extract the function pointer from the vtable. */
3084 e2 = fold_build2_loc (input_location,
3085 POINTER_PLUS_EXPR, TREE_TYPE (vtbl), vtbl,
3086 fold_convert (sizetype, idx));
3087 e2 = cp_build_indirect_ref (e2, RO_NULL, tf_warning_or_error);
3088 TREE_CONSTANT (e2) = 1;
3089
3090 /* When using function descriptors, the address of the
3091 vtable entry is treated as a function pointer. */
3092 if (TARGET_VTABLE_USES_DESCRIPTORS)
3093 e2 = build1 (NOP_EXPR, TREE_TYPE (e2),
3094 cp_build_addr_expr (e2, tf_warning_or_error));
3095
3096 e2 = fold_convert (TREE_TYPE (e3), e2);
3097 e1 = build_conditional_expr (e1, e2, e3, tf_warning_or_error);
3098
3099 /* Make sure this doesn't get evaluated first inside one of the
3100 branches of the COND_EXPR. */
3101 if (instance_save_expr)
3102 e1 = build2 (COMPOUND_EXPR, TREE_TYPE (e1),
3103 instance_save_expr, e1);
3104
3105 function = e1;
3106 }
3107 return function;
3108 }
3109
3110 /* Used by the C-common bits. */
3111 tree
3112 build_function_call (location_t loc ATTRIBUTE_UNUSED,
3113 tree function, tree params)
3114 {
3115 return cp_build_function_call (function, params, tf_warning_or_error);
3116 }
3117
3118 /* Used by the C-common bits. */
3119 tree
3120 build_function_call_vec (location_t loc ATTRIBUTE_UNUSED,
3121 tree function, VEC(tree,gc) *params,
3122 VEC(tree,gc) *origtypes ATTRIBUTE_UNUSED)
3123 {
3124 VEC(tree,gc) *orig_params = params;
3125 tree ret = cp_build_function_call_vec (function, &params,
3126 tf_warning_or_error);
3127
3128 /* cp_build_function_call_vec can reallocate PARAMS by adding
3129 default arguments. That should never happen here. Verify
3130 that. */
3131 gcc_assert (params == orig_params);
3132
3133 return ret;
3134 }
3135
3136 /* Build a function call using a tree list of arguments. */
3137
3138 tree
3139 cp_build_function_call (tree function, tree params, tsubst_flags_t complain)
3140 {
3141 VEC(tree,gc) *vec;
3142 tree ret;
3143
3144 vec = make_tree_vector ();
3145 for (; params != NULL_TREE; params = TREE_CHAIN (params))
3146 VEC_safe_push (tree, gc, vec, TREE_VALUE (params));
3147 ret = cp_build_function_call_vec (function, &vec, complain);
3148 release_tree_vector (vec);
3149 return ret;
3150 }
3151
3152 /* Build a function call using varargs. */
3153
3154 tree
3155 cp_build_function_call_nary (tree function, tsubst_flags_t complain, ...)
3156 {
3157 VEC(tree,gc) *vec;
3158 va_list args;
3159 tree ret, t;
3160
3161 vec = make_tree_vector ();
3162 va_start (args, complain);
3163 for (t = va_arg (args, tree); t != NULL_TREE; t = va_arg (args, tree))
3164 VEC_safe_push (tree, gc, vec, t);
3165 va_end (args);
3166 ret = cp_build_function_call_vec (function, &vec, complain);
3167 release_tree_vector (vec);
3168 return ret;
3169 }
3170
3171 /* Build a function call using a vector of arguments. PARAMS may be
3172 NULL if there are no parameters. This changes the contents of
3173 PARAMS. */
3174
3175 tree
3176 cp_build_function_call_vec (tree function, VEC(tree,gc) **params,
3177 tsubst_flags_t complain)
3178 {
3179 tree fntype, fndecl;
3180 int is_method;
3181 tree original = function;
3182 int nargs;
3183 tree *argarray;
3184 tree parm_types;
3185 VEC(tree,gc) *allocated = NULL;
3186 tree ret;
3187
3188 /* For Objective-C, convert any calls via a cast to OBJC_TYPE_REF
3189 expressions, like those used for ObjC messenger dispatches. */
3190 if (params != NULL && !VEC_empty (tree, *params))
3191 function = objc_rewrite_function_call (function,
3192 VEC_index (tree, *params, 0));
3193
3194 /* build_c_cast puts on a NOP_EXPR to make the result not an lvalue.
3195 Strip such NOP_EXPRs, since FUNCTION is used in non-lvalue context. */
3196 if (TREE_CODE (function) == NOP_EXPR
3197 && TREE_TYPE (function) == TREE_TYPE (TREE_OPERAND (function, 0)))
3198 function = TREE_OPERAND (function, 0);
3199
3200 if (TREE_CODE (function) == FUNCTION_DECL)
3201 {
3202 mark_used (function);
3203 fndecl = function;
3204
3205 /* Convert anything with function type to a pointer-to-function. */
3206 if (DECL_MAIN_P (function) && (complain & tf_error))
3207 pedwarn (input_location, OPT_pedantic,
3208 "ISO C++ forbids calling %<::main%> from within program");
3209
3210 function = build_addr_func (function);
3211 }
3212 else
3213 {
3214 fndecl = NULL_TREE;
3215
3216 function = build_addr_func (function);
3217 }
3218
3219 if (function == error_mark_node)
3220 return error_mark_node;
3221
3222 fntype = TREE_TYPE (function);
3223
3224 if (TYPE_PTRMEMFUNC_P (fntype))
3225 {
3226 if (complain & tf_error)
3227 error ("must use %<.*%> or %<->*%> to call pointer-to-member "
3228 "function in %<%E (...)%>, e.g. %<(... ->* %E) (...)%>",
3229 original, original);
3230 return error_mark_node;
3231 }
3232
3233 is_method = (TREE_CODE (fntype) == POINTER_TYPE
3234 && TREE_CODE (TREE_TYPE (fntype)) == METHOD_TYPE);
3235
3236 if (!((TREE_CODE (fntype) == POINTER_TYPE
3237 && TREE_CODE (TREE_TYPE (fntype)) == FUNCTION_TYPE)
3238 || is_method
3239 || TREE_CODE (function) == TEMPLATE_ID_EXPR))
3240 {
3241 if (complain & tf_error)
3242 error ("%qE cannot be used as a function", original);
3243 return error_mark_node;
3244 }
3245
3246 /* fntype now gets the type of function pointed to. */
3247 fntype = TREE_TYPE (fntype);
3248 parm_types = TYPE_ARG_TYPES (fntype);
3249
3250 if (params == NULL)
3251 {
3252 allocated = make_tree_vector ();
3253 params = &allocated;
3254 }
3255
3256 nargs = convert_arguments (parm_types, params, fndecl, LOOKUP_NORMAL,
3257 complain);
3258 if (nargs < 0)
3259 return error_mark_node;
3260
3261 argarray = VEC_address (tree, *params);
3262
3263 /* Check for errors in format strings and inappropriately
3264 null parameters. */
3265 check_function_arguments (TYPE_ATTRIBUTES (fntype), nargs, argarray,
3266 parm_types);
3267
3268 ret = build_cxx_call (function, nargs, argarray);
3269
3270 if (allocated != NULL)
3271 release_tree_vector (allocated);
3272
3273 return ret;
3274 }
3275 \f
3276 /* Subroutine of convert_arguments.
3277 Warn about wrong number of args are genereted. */
3278
3279 static void
3280 warn_args_num (location_t loc, tree fndecl, bool too_many_p)
3281 {
3282 if (fndecl)
3283 {
3284 if (TREE_CODE (TREE_TYPE (fndecl)) == METHOD_TYPE)
3285 {
3286 if (DECL_NAME (fndecl) == NULL_TREE
3287 || IDENTIFIER_HAS_TYPE_VALUE (DECL_NAME (fndecl)))
3288 error_at (loc,
3289 too_many_p
3290 ? G_("too many arguments to constructor %q#D")
3291 : G_("too few arguments to constructor %q#D"),
3292 fndecl);
3293 else
3294 error_at (loc,
3295 too_many_p
3296 ? G_("too many arguments to member function %q#D")
3297 : G_("too few arguments to member function %q#D"),
3298 fndecl);
3299 }
3300 else
3301 error_at (loc,
3302 too_many_p
3303 ? G_("too many arguments to function %q#D")
3304 : G_("too few arguments to function %q#D"),
3305 fndecl);
3306 inform (DECL_SOURCE_LOCATION (fndecl),
3307 "declared here");
3308 }
3309 else
3310 {
3311 if (c_dialect_objc () && objc_message_selector ())
3312 error_at (loc,
3313 too_many_p
3314 ? G_("too many arguments to method %q#D")
3315 : G_("too few arguments to method %q#D"),
3316 objc_message_selector ());
3317 else
3318 error_at (loc, too_many_p ? G_("too many arguments to function")
3319 : G_("too few arguments to function"));
3320 }
3321 }
3322
3323 /* Convert the actual parameter expressions in the list VALUES to the
3324 types in the list TYPELIST. The converted expressions are stored
3325 back in the VALUES vector.
3326 If parmdecls is exhausted, or when an element has NULL as its type,
3327 perform the default conversions.
3328
3329 NAME is an IDENTIFIER_NODE or 0. It is used only for error messages.
3330
3331 This is also where warnings about wrong number of args are generated.
3332
3333 Returns the actual number of arguments processed (which might be less
3334 than the length of the vector), or -1 on error.
3335
3336 In C++, unspecified trailing parameters can be filled in with their
3337 default arguments, if such were specified. Do so here. */
3338
3339 static int
3340 convert_arguments (tree typelist, VEC(tree,gc) **values, tree fndecl,
3341 int flags, tsubst_flags_t complain)
3342 {
3343 tree typetail;
3344 unsigned int i;
3345
3346 /* Argument passing is always copy-initialization. */
3347 flags |= LOOKUP_ONLYCONVERTING;
3348
3349 for (i = 0, typetail = typelist;
3350 i < VEC_length (tree, *values);
3351 i++)
3352 {
3353 tree type = typetail ? TREE_VALUE (typetail) : 0;
3354 tree val = VEC_index (tree, *values, i);
3355
3356 if (val == error_mark_node || type == error_mark_node)
3357 return -1;
3358
3359 if (type == void_type_node)
3360 {
3361 if (complain & tf_error)
3362 {
3363 warn_args_num (input_location, fndecl, /*too_many_p=*/true);
3364 return i;
3365 }
3366 else
3367 return -1;
3368 }
3369
3370 /* build_c_cast puts on a NOP_EXPR to make the result not an lvalue.
3371 Strip such NOP_EXPRs, since VAL is used in non-lvalue context. */
3372 if (TREE_CODE (val) == NOP_EXPR
3373 && TREE_TYPE (val) == TREE_TYPE (TREE_OPERAND (val, 0))
3374 && (type == 0 || TREE_CODE (type) != REFERENCE_TYPE))
3375 val = TREE_OPERAND (val, 0);
3376
3377 if (type == 0 || TREE_CODE (type) != REFERENCE_TYPE)
3378 {
3379 if (TREE_CODE (TREE_TYPE (val)) == ARRAY_TYPE
3380 || TREE_CODE (TREE_TYPE (val)) == FUNCTION_TYPE
3381 || TREE_CODE (TREE_TYPE (val)) == METHOD_TYPE)
3382 val = decay_conversion (val);
3383 }
3384
3385 if (val == error_mark_node)
3386 return -1;
3387
3388 if (type != 0)
3389 {
3390 /* Formal parm type is specified by a function prototype. */
3391 tree parmval;
3392
3393 if (!COMPLETE_TYPE_P (complete_type (type)))
3394 {
3395 if (complain & tf_error)
3396 {
3397 if (fndecl)
3398 error ("parameter %P of %qD has incomplete type %qT",
3399 i, fndecl, type);
3400 else
3401 error ("parameter %P has incomplete type %qT", i, type);
3402 }
3403 parmval = error_mark_node;
3404 }
3405 else
3406 {
3407 parmval = convert_for_initialization
3408 (NULL_TREE, type, val, flags,
3409 ICR_ARGPASS, fndecl, i, complain);
3410 parmval = convert_for_arg_passing (type, parmval);
3411 }
3412
3413 if (parmval == error_mark_node)
3414 return -1;
3415
3416 VEC_replace (tree, *values, i, parmval);
3417 }
3418 else
3419 {
3420 if (fndecl && DECL_BUILT_IN (fndecl)
3421 && DECL_FUNCTION_CODE (fndecl) == BUILT_IN_CONSTANT_P)
3422 /* Don't do ellipsis conversion for __built_in_constant_p
3423 as this will result in spurious errors for non-trivial
3424 types. */
3425 val = require_complete_type_sfinae (val, complain);
3426 else
3427 val = convert_arg_to_ellipsis (val);
3428
3429 VEC_replace (tree, *values, i, val);
3430 }
3431
3432 if (typetail)
3433 typetail = TREE_CHAIN (typetail);
3434 }
3435
3436 if (typetail != 0 && typetail != void_list_node)
3437 {
3438 /* See if there are default arguments that can be used. Because
3439 we hold default arguments in the FUNCTION_TYPE (which is so
3440 wrong), we can see default parameters here from deduced
3441 contexts (and via typeof) for indirect function calls.
3442 Fortunately we know whether we have a function decl to
3443 provide default arguments in a language conformant
3444 manner. */
3445 if (fndecl && TREE_PURPOSE (typetail)
3446 && TREE_CODE (TREE_PURPOSE (typetail)) != DEFAULT_ARG)
3447 {
3448 for (; typetail != void_list_node; ++i)
3449 {
3450 tree parmval
3451 = convert_default_arg (TREE_VALUE (typetail),
3452 TREE_PURPOSE (typetail),
3453 fndecl, i);
3454
3455 if (parmval == error_mark_node)
3456 return -1;
3457
3458 VEC_safe_push (tree, gc, *values, parmval);
3459 typetail = TREE_CHAIN (typetail);
3460 /* ends with `...'. */
3461 if (typetail == NULL_TREE)
3462 break;
3463 }
3464 }
3465 else
3466 {
3467 if (complain & tf_error)
3468 warn_args_num (input_location, fndecl, /*too_many_p=*/false);
3469 return -1;
3470 }
3471 }
3472
3473 return (int) i;
3474 }
3475 \f
3476 /* Build a binary-operation expression, after performing default
3477 conversions on the operands. CODE is the kind of expression to
3478 build. ARG1 and ARG2 are the arguments. ARG1_CODE and ARG2_CODE
3479 are the tree codes which correspond to ARG1 and ARG2 when issuing
3480 warnings about possibly misplaced parentheses. They may differ
3481 from the TREE_CODE of ARG1 and ARG2 if the parser has done constant
3482 folding (e.g., if the parser sees "a | 1 + 1", it may call this
3483 routine with ARG2 being an INTEGER_CST and ARG2_CODE == PLUS_EXPR).
3484 To avoid issuing any parentheses warnings, pass ARG1_CODE and/or
3485 ARG2_CODE as ERROR_MARK. */
3486
3487 tree
3488 build_x_binary_op (enum tree_code code, tree arg1, enum tree_code arg1_code,
3489 tree arg2, enum tree_code arg2_code, bool *overloaded_p,
3490 tsubst_flags_t complain)
3491 {
3492 tree orig_arg1;
3493 tree orig_arg2;
3494 tree expr;
3495
3496 orig_arg1 = arg1;
3497 orig_arg2 = arg2;
3498
3499 if (processing_template_decl)
3500 {
3501 if (type_dependent_expression_p (arg1)
3502 || type_dependent_expression_p (arg2))
3503 return build_min_nt (code, arg1, arg2);
3504 arg1 = build_non_dependent_expr (arg1);
3505 arg2 = build_non_dependent_expr (arg2);
3506 }
3507
3508 if (code == DOTSTAR_EXPR)
3509 expr = build_m_component_ref (arg1, arg2);
3510 else
3511 expr = build_new_op (code, LOOKUP_NORMAL, arg1, arg2, NULL_TREE,
3512 overloaded_p, complain);
3513
3514 /* Check for cases such as x+y<<z which users are likely to
3515 misinterpret. But don't warn about obj << x + y, since that is a
3516 common idiom for I/O. */
3517 if (warn_parentheses
3518 && (complain & tf_warning)
3519 && !processing_template_decl
3520 && !error_operand_p (arg1)
3521 && !error_operand_p (arg2)
3522 && (code != LSHIFT_EXPR
3523 || !CLASS_TYPE_P (TREE_TYPE (arg1))))
3524 warn_about_parentheses (code, arg1_code, orig_arg1, arg2_code, orig_arg2);
3525
3526 if (processing_template_decl && expr != error_mark_node)
3527 return build_min_non_dep (code, expr, orig_arg1, orig_arg2);
3528
3529 return expr;
3530 }
3531
3532 /* Build and return an ARRAY_REF expression. */
3533
3534 tree
3535 build_x_array_ref (tree arg1, tree arg2, tsubst_flags_t complain)
3536 {
3537 tree orig_arg1 = arg1;
3538 tree orig_arg2 = arg2;
3539 tree expr;
3540
3541 if (processing_template_decl)
3542 {
3543 if (type_dependent_expression_p (arg1)
3544 || type_dependent_expression_p (arg2))
3545 return build_min_nt (ARRAY_REF, arg1, arg2,
3546 NULL_TREE, NULL_TREE);
3547 arg1 = build_non_dependent_expr (arg1);
3548 arg2 = build_non_dependent_expr (arg2);
3549 }
3550
3551 expr = build_new_op (ARRAY_REF, LOOKUP_NORMAL, arg1, arg2, NULL_TREE,
3552 /*overloaded_p=*/NULL, complain);
3553
3554 if (processing_template_decl && expr != error_mark_node)
3555 return build_min_non_dep (ARRAY_REF, expr, orig_arg1, orig_arg2,
3556 NULL_TREE, NULL_TREE);
3557 return expr;
3558 }
3559
3560 /* For the c-common bits. */
3561 tree
3562 build_binary_op (location_t location, enum tree_code code, tree op0, tree op1,
3563 int convert_p ATTRIBUTE_UNUSED)
3564 {
3565 return cp_build_binary_op (location, code, op0, op1, tf_warning_or_error);
3566 }
3567
3568
3569 /* Build a binary-operation expression without default conversions.
3570 CODE is the kind of expression to build.
3571 LOCATION is the location_t of the operator in the source code.
3572 This function differs from `build' in several ways:
3573 the data type of the result is computed and recorded in it,
3574 warnings are generated if arg data types are invalid,
3575 special handling for addition and subtraction of pointers is known,
3576 and some optimization is done (operations on narrow ints
3577 are done in the narrower type when that gives the same result).
3578 Constant folding is also done before the result is returned.
3579
3580 Note that the operands will never have enumeral types
3581 because either they have just had the default conversions performed
3582 or they have both just been converted to some other type in which
3583 the arithmetic is to be done.
3584
3585 C++: must do special pointer arithmetic when implementing
3586 multiple inheritance, and deal with pointer to member functions. */
3587
3588 tree
3589 cp_build_binary_op (location_t location,
3590 enum tree_code code, tree orig_op0, tree orig_op1,
3591 tsubst_flags_t complain)
3592 {
3593 tree op0, op1;
3594 enum tree_code code0, code1;
3595 tree type0, type1;
3596 const char *invalid_op_diag;
3597
3598 /* Expression code to give to the expression when it is built.
3599 Normally this is CODE, which is what the caller asked for,
3600 but in some special cases we change it. */
3601 enum tree_code resultcode = code;
3602
3603 /* Data type in which the computation is to be performed.
3604 In the simplest cases this is the common type of the arguments. */
3605 tree result_type = NULL;
3606
3607 /* Nonzero means operands have already been type-converted
3608 in whatever way is necessary.
3609 Zero means they need to be converted to RESULT_TYPE. */
3610 int converted = 0;
3611
3612 /* Nonzero means create the expression with this type, rather than
3613 RESULT_TYPE. */
3614 tree build_type = 0;
3615
3616 /* Nonzero means after finally constructing the expression
3617 convert it to this type. */
3618 tree final_type = 0;
3619
3620 tree result;
3621
3622 /* Nonzero if this is an operation like MIN or MAX which can
3623 safely be computed in short if both args are promoted shorts.
3624 Also implies COMMON.
3625 -1 indicates a bitwise operation; this makes a difference
3626 in the exact conditions for when it is safe to do the operation
3627 in a narrower mode. */
3628 int shorten = 0;
3629
3630 /* Nonzero if this is a comparison operation;
3631 if both args are promoted shorts, compare the original shorts.
3632 Also implies COMMON. */
3633 int short_compare = 0;
3634
3635 /* Nonzero means set RESULT_TYPE to the common type of the args. */
3636 int common = 0;
3637
3638 /* True if both operands have arithmetic type. */
3639 bool arithmetic_types_p;
3640
3641 /* Apply default conversions. */
3642 op0 = orig_op0;
3643 op1 = orig_op1;
3644
3645 if (code == TRUTH_AND_EXPR || code == TRUTH_ANDIF_EXPR
3646 || code == TRUTH_OR_EXPR || code == TRUTH_ORIF_EXPR
3647 || code == TRUTH_XOR_EXPR)
3648 {
3649 if (!really_overloaded_fn (op0))
3650 op0 = decay_conversion (op0);
3651 if (!really_overloaded_fn (op1))
3652 op1 = decay_conversion (op1);
3653 }
3654 else
3655 {
3656 if (!really_overloaded_fn (op0))
3657 op0 = default_conversion (op0);
3658 if (!really_overloaded_fn (op1))
3659 op1 = default_conversion (op1);
3660 }
3661
3662 /* Strip NON_LVALUE_EXPRs, etc., since we aren't using as an lvalue. */
3663 STRIP_TYPE_NOPS (op0);
3664 STRIP_TYPE_NOPS (op1);
3665
3666 /* DTRT if one side is an overloaded function, but complain about it. */
3667 if (type_unknown_p (op0))
3668 {
3669 tree t = instantiate_type (TREE_TYPE (op1), op0, tf_none);
3670 if (t != error_mark_node)
3671 {
3672 if (complain & tf_error)
3673 permerror (input_location, "assuming cast to type %qT from overloaded function",
3674 TREE_TYPE (t));
3675 op0 = t;
3676 }
3677 }
3678 if (type_unknown_p (op1))
3679 {
3680 tree t = instantiate_type (TREE_TYPE (op0), op1, tf_none);
3681 if (t != error_mark_node)
3682 {
3683 if (complain & tf_error)
3684 permerror (input_location, "assuming cast to type %qT from overloaded function",
3685 TREE_TYPE (t));
3686 op1 = t;
3687 }
3688 }
3689
3690 type0 = TREE_TYPE (op0);
3691 type1 = TREE_TYPE (op1);
3692
3693 /* The expression codes of the data types of the arguments tell us
3694 whether the arguments are integers, floating, pointers, etc. */
3695 code0 = TREE_CODE (type0);
3696 code1 = TREE_CODE (type1);
3697
3698 /* If an error was already reported for one of the arguments,
3699 avoid reporting another error. */
3700 if (code0 == ERROR_MARK || code1 == ERROR_MARK)
3701 return error_mark_node;
3702
3703 if ((invalid_op_diag
3704 = targetm.invalid_binary_op (code, type0, type1)))
3705 {
3706 error (invalid_op_diag);
3707 return error_mark_node;
3708 }
3709
3710 /* Issue warnings about peculiar, but valid, uses of NULL. */
3711 if ((orig_op0 == null_node || orig_op1 == null_node)
3712 /* It's reasonable to use pointer values as operands of &&
3713 and ||, so NULL is no exception. */
3714 && code != TRUTH_ANDIF_EXPR && code != TRUTH_ORIF_EXPR
3715 && ( /* Both are NULL (or 0) and the operation was not a
3716 comparison or a pointer subtraction. */
3717 (null_ptr_cst_p (orig_op0) && null_ptr_cst_p (orig_op1)
3718 && code != EQ_EXPR && code != NE_EXPR && code != MINUS_EXPR)
3719 /* Or if one of OP0 or OP1 is neither a pointer nor NULL. */
3720 || (!null_ptr_cst_p (orig_op0)
3721 && !TYPE_PTR_P (type0) && !TYPE_PTR_TO_MEMBER_P (type0))
3722 || (!null_ptr_cst_p (orig_op1)
3723 && !TYPE_PTR_P (type1) && !TYPE_PTR_TO_MEMBER_P (type1)))
3724 && (complain & tf_warning))
3725 /* Some sort of arithmetic operation involving NULL was
3726 performed. */
3727 warning (OPT_Wpointer_arith, "NULL used in arithmetic");
3728
3729 switch (code)
3730 {
3731 case MINUS_EXPR:
3732 /* Subtraction of two similar pointers.
3733 We must subtract them as integers, then divide by object size. */
3734 if (code0 == POINTER_TYPE && code1 == POINTER_TYPE
3735 && same_type_ignoring_top_level_qualifiers_p (TREE_TYPE (type0),
3736 TREE_TYPE (type1)))
3737 return pointer_diff (op0, op1, common_pointer_type (type0, type1));
3738 /* In all other cases except pointer - int, the usual arithmetic
3739 rules apply. */
3740 else if (!(code0 == POINTER_TYPE && code1 == INTEGER_TYPE))
3741 {
3742 common = 1;
3743 break;
3744 }
3745 /* The pointer - int case is just like pointer + int; fall
3746 through. */
3747 case PLUS_EXPR:
3748 if ((code0 == POINTER_TYPE || code1 == POINTER_TYPE)
3749 && (code0 == INTEGER_TYPE || code1 == INTEGER_TYPE))
3750 {
3751 tree ptr_operand;
3752 tree int_operand;
3753 ptr_operand = ((code0 == POINTER_TYPE) ? op0 : op1);
3754 int_operand = ((code0 == INTEGER_TYPE) ? op0 : op1);
3755 if (processing_template_decl)
3756 {
3757 result_type = TREE_TYPE (ptr_operand);
3758 break;
3759 }
3760 return cp_pointer_int_sum (code,
3761 ptr_operand,
3762 int_operand);
3763 }
3764 common = 1;
3765 break;
3766
3767 case MULT_EXPR:
3768 common = 1;
3769 break;
3770
3771 case TRUNC_DIV_EXPR:
3772 case CEIL_DIV_EXPR:
3773 case FLOOR_DIV_EXPR:
3774 case ROUND_DIV_EXPR:
3775 case EXACT_DIV_EXPR:
3776 if ((code0 == INTEGER_TYPE || code0 == REAL_TYPE
3777 || code0 == COMPLEX_TYPE || code0 == VECTOR_TYPE)
3778 && (code1 == INTEGER_TYPE || code1 == REAL_TYPE
3779 || code1 == COMPLEX_TYPE || code1 == VECTOR_TYPE))
3780 {
3781 enum tree_code tcode0 = code0, tcode1 = code1;
3782
3783 warn_for_div_by_zero (location, op1);
3784
3785 if (tcode0 == COMPLEX_TYPE || tcode0 == VECTOR_TYPE)
3786 tcode0 = TREE_CODE (TREE_TYPE (TREE_TYPE (op0)));
3787 if (tcode1 == COMPLEX_TYPE || tcode1 == VECTOR_TYPE)
3788 tcode1 = TREE_CODE (TREE_TYPE (TREE_TYPE (op1)));
3789
3790 if (!(tcode0 == INTEGER_TYPE && tcode1 == INTEGER_TYPE))
3791 resultcode = RDIV_EXPR;
3792 else
3793 /* When dividing two signed integers, we have to promote to int.
3794 unless we divide by a constant != -1. Note that default
3795 conversion will have been performed on the operands at this
3796 point, so we have to dig out the original type to find out if
3797 it was unsigned. */
3798 shorten = ((TREE_CODE (op0) == NOP_EXPR
3799 && TYPE_UNSIGNED (TREE_TYPE (TREE_OPERAND (op0, 0))))
3800 || (TREE_CODE (op1) == INTEGER_CST
3801 && ! integer_all_onesp (op1)));
3802
3803 common = 1;
3804 }
3805 break;
3806
3807 case BIT_AND_EXPR:
3808 case BIT_IOR_EXPR:
3809 case BIT_XOR_EXPR:
3810 if ((code0 == INTEGER_TYPE && code1 == INTEGER_TYPE)
3811 || (code0 == VECTOR_TYPE && code1 == VECTOR_TYPE
3812 && !VECTOR_FLOAT_TYPE_P (type0)
3813 && !VECTOR_FLOAT_TYPE_P (type1)))
3814 shorten = -1;
3815 break;
3816
3817 case TRUNC_MOD_EXPR:
3818 case FLOOR_MOD_EXPR:
3819 warn_for_div_by_zero (location, op1);
3820
3821 if (code0 == VECTOR_TYPE && code1 == VECTOR_TYPE
3822 && TREE_CODE (TREE_TYPE (type0)) == INTEGER_TYPE
3823 && TREE_CODE (TREE_TYPE (type1)) == INTEGER_TYPE)
3824 common = 1;
3825 else if (code0 == INTEGER_TYPE && code1 == INTEGER_TYPE)
3826 {
3827 /* Although it would be tempting to shorten always here, that loses
3828 on some targets, since the modulo instruction is undefined if the
3829 quotient can't be represented in the computation mode. We shorten
3830 only if unsigned or if dividing by something we know != -1. */
3831 shorten = ((TREE_CODE (op0) == NOP_EXPR
3832 && TYPE_UNSIGNED (TREE_TYPE (TREE_OPERAND (op0, 0))))
3833 || (TREE_CODE (op1) == INTEGER_CST
3834 && ! integer_all_onesp (op1)));
3835 common = 1;
3836 }
3837 break;
3838
3839 case TRUTH_ANDIF_EXPR:
3840 case TRUTH_ORIF_EXPR:
3841 case TRUTH_AND_EXPR:
3842 case TRUTH_OR_EXPR:
3843 result_type = boolean_type_node;
3844 break;
3845
3846 /* Shift operations: result has same type as first operand;
3847 always convert second operand to int.
3848 Also set SHORT_SHIFT if shifting rightward. */
3849
3850 case RSHIFT_EXPR:
3851 if (code0 == INTEGER_TYPE && code1 == INTEGER_TYPE)
3852 {
3853 result_type = type0;
3854 if (TREE_CODE (op1) == INTEGER_CST)
3855 {
3856 if (tree_int_cst_lt (op1, integer_zero_node))
3857 {
3858 if ((complain & tf_warning)
3859 && c_inhibit_evaluation_warnings == 0)
3860 warning (0, "right shift count is negative");
3861 }
3862 else
3863 {
3864 if (compare_tree_int (op1, TYPE_PRECISION (type0)) >= 0
3865 && (complain & tf_warning)
3866 && c_inhibit_evaluation_warnings == 0)
3867 warning (0, "right shift count >= width of type");
3868 }
3869 }
3870 /* Convert the shift-count to an integer, regardless of
3871 size of value being shifted. */
3872 if (TYPE_MAIN_VARIANT (TREE_TYPE (op1)) != integer_type_node)
3873 op1 = cp_convert (integer_type_node, op1);
3874 /* Avoid converting op1 to result_type later. */
3875 converted = 1;
3876 }
3877 break;
3878
3879 case LSHIFT_EXPR:
3880 if (code0 == INTEGER_TYPE && code1 == INTEGER_TYPE)
3881 {
3882 result_type = type0;
3883 if (TREE_CODE (op1) == INTEGER_CST)
3884 {
3885 if (tree_int_cst_lt (op1, integer_zero_node))
3886 {
3887 if ((complain & tf_warning)
3888 && c_inhibit_evaluation_warnings == 0)
3889 warning (0, "left shift count is negative");
3890 }
3891 else if (compare_tree_int (op1, TYPE_PRECISION (type0)) >= 0)
3892 {
3893 if ((complain & tf_warning)
3894 && c_inhibit_evaluation_warnings == 0)
3895 warning (0, "left shift count >= width of type");
3896 }
3897 }
3898 /* Convert the shift-count to an integer, regardless of
3899 size of value being shifted. */
3900 if (TYPE_MAIN_VARIANT (TREE_TYPE (op1)) != integer_type_node)
3901 op1 = cp_convert (integer_type_node, op1);
3902 /* Avoid converting op1 to result_type later. */
3903 converted = 1;
3904 }
3905 break;
3906
3907 case RROTATE_EXPR:
3908 case LROTATE_EXPR:
3909 if (code0 == INTEGER_TYPE && code1 == INTEGER_TYPE)
3910 {
3911 result_type = type0;
3912 if (TREE_CODE (op1) == INTEGER_CST)
3913 {
3914 if (tree_int_cst_lt (op1, integer_zero_node))
3915 {
3916 if (complain & tf_warning)
3917 warning (0, (code == LROTATE_EXPR)
3918 ? G_("left rotate count is negative")
3919 : G_("right rotate count is negative"));
3920 }
3921 else if (compare_tree_int (op1, TYPE_PRECISION (type0)) >= 0)
3922 {
3923 if (complain & tf_warning)
3924 warning (0, (code == LROTATE_EXPR)
3925 ? G_("left rotate count >= width of type")
3926 : G_("right rotate count >= width of type"));
3927 }
3928 }
3929 /* Convert the shift-count to an integer, regardless of
3930 size of value being shifted. */
3931 if (TYPE_MAIN_VARIANT (TREE_TYPE (op1)) != integer_type_node)
3932 op1 = cp_convert (integer_type_node, op1);
3933 }
3934 break;
3935
3936 case EQ_EXPR:
3937 case NE_EXPR:
3938 if ((complain & tf_warning)
3939 && (FLOAT_TYPE_P (type0) || FLOAT_TYPE_P (type1)))
3940 warning (OPT_Wfloat_equal,
3941 "comparing floating point with == or != is unsafe");
3942 if ((complain & tf_warning)
3943 && ((TREE_CODE (orig_op0) == STRING_CST && !integer_zerop (op1))
3944 || (TREE_CODE (orig_op1) == STRING_CST && !integer_zerop (op0))))
3945 warning (OPT_Waddress, "comparison with string literal results in unspecified behaviour");
3946
3947 build_type = boolean_type_node;
3948 if ((code0 == INTEGER_TYPE || code0 == REAL_TYPE
3949 || code0 == COMPLEX_TYPE || code0 == ENUMERAL_TYPE)
3950 && (code1 == INTEGER_TYPE || code1 == REAL_TYPE
3951 || code1 == COMPLEX_TYPE || code1 == ENUMERAL_TYPE))
3952 short_compare = 1;
3953 else if ((code0 == POINTER_TYPE && code1 == POINTER_TYPE)
3954 || (TYPE_PTRMEM_P (type0) && TYPE_PTRMEM_P (type1)))
3955 result_type = composite_pointer_type (type0, type1, op0, op1,
3956 CPO_COMPARISON, complain);
3957 else if ((code0 == POINTER_TYPE || TYPE_PTRMEM_P (type0))
3958 && null_ptr_cst_p (op1))
3959 {
3960 if (TREE_CODE (op0) == ADDR_EXPR
3961 && decl_with_nonnull_addr_p (TREE_OPERAND (op0, 0)))
3962 {
3963 if (complain & tf_warning)
3964 warning (OPT_Waddress, "the address of %qD will never be NULL",
3965 TREE_OPERAND (op0, 0));
3966 }
3967 result_type = type0;
3968 }
3969 else if ((code1 == POINTER_TYPE || TYPE_PTRMEM_P (type1))
3970 && null_ptr_cst_p (op0))
3971 {
3972 if (TREE_CODE (op1) == ADDR_EXPR
3973 && decl_with_nonnull_addr_p (TREE_OPERAND (op1, 0)))
3974 {
3975 if (complain & tf_warning)
3976 warning (OPT_Waddress, "the address of %qD will never be NULL",
3977 TREE_OPERAND (op1, 0));
3978 }
3979 result_type = type1;
3980 }
3981 else if (null_ptr_cst_p (op0) && null_ptr_cst_p (op1))
3982 /* One of the operands must be of nullptr_t type. */
3983 result_type = TREE_TYPE (nullptr_node);
3984 else if (code0 == POINTER_TYPE && code1 == INTEGER_TYPE)
3985 {
3986 result_type = type0;
3987 if (complain & tf_error)
3988 permerror (input_location, "ISO C++ forbids comparison between pointer and integer");
3989 else
3990 return error_mark_node;
3991 }
3992 else if (code0 == INTEGER_TYPE && code1 == POINTER_TYPE)
3993 {
3994 result_type = type1;
3995 if (complain & tf_error)
3996 permerror (input_location, "ISO C++ forbids comparison between pointer and integer");
3997 else
3998 return error_mark_node;
3999 }
4000 else if (TYPE_PTRMEMFUNC_P (type0) && null_ptr_cst_p (op1))
4001 {
4002 if (TARGET_PTRMEMFUNC_VBIT_LOCATION
4003 == ptrmemfunc_vbit_in_delta)
4004 {
4005 tree pfn0 = pfn_from_ptrmemfunc (op0);
4006 tree delta0 = delta_from_ptrmemfunc (op0);
4007 tree e1 = cp_build_binary_op (location,
4008 EQ_EXPR,
4009 pfn0,
4010 build_zero_cst (TREE_TYPE (pfn0)),
4011 complain);
4012 tree e2 = cp_build_binary_op (location,
4013 BIT_AND_EXPR,
4014 delta0,
4015 integer_one_node,
4016 complain);
4017 e2 = cp_build_binary_op (location,
4018 EQ_EXPR, e2, integer_zero_node,
4019 complain);
4020 op0 = cp_build_binary_op (location,
4021 TRUTH_ANDIF_EXPR, e1, e2,
4022 complain);
4023 op1 = cp_convert (TREE_TYPE (op0), integer_one_node);
4024 }
4025 else
4026 {
4027 op0 = build_ptrmemfunc_access_expr (op0, pfn_identifier);
4028 op1 = cp_convert (TREE_TYPE (op0), integer_zero_node);
4029 }
4030 result_type = TREE_TYPE (op0);
4031 }
4032 else if (TYPE_PTRMEMFUNC_P (type1) && null_ptr_cst_p (op0))
4033 return cp_build_binary_op (location, code, op1, op0, complain);
4034 else if (TYPE_PTRMEMFUNC_P (type0) && TYPE_PTRMEMFUNC_P (type1))
4035 {
4036 tree type;
4037 /* E will be the final comparison. */
4038 tree e;
4039 /* E1 and E2 are for scratch. */
4040 tree e1;
4041 tree e2;
4042 tree pfn0;
4043 tree pfn1;
4044 tree delta0;
4045 tree delta1;
4046
4047 type = composite_pointer_type (type0, type1, op0, op1,
4048 CPO_COMPARISON, complain);
4049
4050 if (!same_type_p (TREE_TYPE (op0), type))
4051 op0 = cp_convert_and_check (type, op0);
4052 if (!same_type_p (TREE_TYPE (op1), type))
4053 op1 = cp_convert_and_check (type, op1);
4054
4055 if (op0 == error_mark_node || op1 == error_mark_node)
4056 return error_mark_node;
4057
4058 if (TREE_SIDE_EFFECTS (op0))
4059 op0 = save_expr (op0);
4060 if (TREE_SIDE_EFFECTS (op1))
4061 op1 = save_expr (op1);
4062
4063 pfn0 = pfn_from_ptrmemfunc (op0);
4064 pfn1 = pfn_from_ptrmemfunc (op1);
4065 delta0 = delta_from_ptrmemfunc (op0);
4066 delta1 = delta_from_ptrmemfunc (op1);
4067 if (TARGET_PTRMEMFUNC_VBIT_LOCATION
4068 == ptrmemfunc_vbit_in_delta)
4069 {
4070 /* We generate:
4071
4072 (op0.pfn == op1.pfn
4073 && ((op0.delta == op1.delta)
4074 || (!op0.pfn && op0.delta & 1 == 0
4075 && op1.delta & 1 == 0))
4076
4077 The reason for the `!op0.pfn' bit is that a NULL
4078 pointer-to-member is any member with a zero PFN and
4079 LSB of the DELTA field is 0. */
4080
4081 e1 = cp_build_binary_op (location, BIT_AND_EXPR,
4082 delta0,
4083 integer_one_node,
4084 complain);
4085 e1 = cp_build_binary_op (location,
4086 EQ_EXPR, e1, integer_zero_node,
4087 complain);
4088 e2 = cp_build_binary_op (location, BIT_AND_EXPR,
4089 delta1,
4090 integer_one_node,
4091 complain);
4092 e2 = cp_build_binary_op (location,
4093 EQ_EXPR, e2, integer_zero_node,
4094 complain);
4095 e1 = cp_build_binary_op (location,
4096 TRUTH_ANDIF_EXPR, e2, e1,
4097 complain);
4098 e2 = cp_build_binary_op (location, EQ_EXPR,
4099 pfn0,
4100 build_zero_cst (TREE_TYPE (pfn0)),
4101 complain);
4102 e2 = cp_build_binary_op (location,
4103 TRUTH_ANDIF_EXPR, e2, e1, complain);
4104 e1 = cp_build_binary_op (location,
4105 EQ_EXPR, delta0, delta1, complain);
4106 e1 = cp_build_binary_op (location,
4107 TRUTH_ORIF_EXPR, e1, e2, complain);
4108 }
4109 else
4110 {
4111 /* We generate:
4112
4113 (op0.pfn == op1.pfn
4114 && (!op0.pfn || op0.delta == op1.delta))
4115
4116 The reason for the `!op0.pfn' bit is that a NULL
4117 pointer-to-member is any member with a zero PFN; the
4118 DELTA field is unspecified. */
4119
4120 e1 = cp_build_binary_op (location,
4121 EQ_EXPR, delta0, delta1, complain);
4122 e2 = cp_build_binary_op (location,
4123 EQ_EXPR,
4124 pfn0,
4125 build_zero_cst (TREE_TYPE (pfn0)),
4126 complain);
4127 e1 = cp_build_binary_op (location,
4128 TRUTH_ORIF_EXPR, e1, e2, complain);
4129 }
4130 e2 = build2 (EQ_EXPR, boolean_type_node, pfn0, pfn1);
4131 e = cp_build_binary_op (location,
4132 TRUTH_ANDIF_EXPR, e2, e1, complain);
4133 if (code == EQ_EXPR)
4134 return e;
4135 return cp_build_binary_op (location,
4136 EQ_EXPR, e, integer_zero_node, complain);
4137 }
4138 else
4139 {
4140 gcc_assert (!TYPE_PTRMEMFUNC_P (type0)
4141 || !same_type_p (TYPE_PTRMEMFUNC_FN_TYPE (type0),
4142 type1));
4143 gcc_assert (!TYPE_PTRMEMFUNC_P (type1)
4144 || !same_type_p (TYPE_PTRMEMFUNC_FN_TYPE (type1),
4145 type0));
4146 }
4147
4148 break;
4149
4150 case MAX_EXPR:
4151 case MIN_EXPR:
4152 if ((code0 == INTEGER_TYPE || code0 == REAL_TYPE)
4153 && (code1 == INTEGER_TYPE || code1 == REAL_TYPE))
4154 shorten = 1;
4155 else if (code0 == POINTER_TYPE && code1 == POINTER_TYPE)
4156 result_type = composite_pointer_type (type0, type1, op0, op1,
4157 CPO_COMPARISON, complain);
4158 break;
4159
4160 case LE_EXPR:
4161 case GE_EXPR:
4162 case LT_EXPR:
4163 case GT_EXPR:
4164 if (TREE_CODE (orig_op0) == STRING_CST
4165 || TREE_CODE (orig_op1) == STRING_CST)
4166 {
4167 if (complain & tf_warning)
4168 warning (OPT_Waddress, "comparison with string literal results in unspecified behaviour");
4169 }
4170
4171 build_type = boolean_type_node;
4172 if ((code0 == INTEGER_TYPE || code0 == REAL_TYPE
4173 || code0 == ENUMERAL_TYPE)
4174 && (code1 == INTEGER_TYPE || code1 == REAL_TYPE
4175 || code1 == ENUMERAL_TYPE))
4176 short_compare = 1;
4177 else if (code0 == POINTER_TYPE && code1 == POINTER_TYPE)
4178 result_type = composite_pointer_type (type0, type1, op0, op1,
4179 CPO_COMPARISON, complain);
4180 else if (code0 == POINTER_TYPE && null_ptr_cst_p (op1))
4181 result_type = type0;
4182 else if (code1 == POINTER_TYPE && null_ptr_cst_p (op0))
4183 result_type = type1;
4184 else if (null_ptr_cst_p (op0) && null_ptr_cst_p (op1))
4185 /* One of the operands must be of nullptr_t type. */
4186 result_type = TREE_TYPE (nullptr_node);
4187 else if (code0 == POINTER_TYPE && code1 == INTEGER_TYPE)
4188 {
4189 result_type = type0;
4190 if (complain & tf_error)
4191 permerror (input_location, "ISO C++ forbids comparison between pointer and integer");
4192 else
4193 return error_mark_node;
4194 }
4195 else if (code0 == INTEGER_TYPE && code1 == POINTER_TYPE)
4196 {
4197 result_type = type1;
4198 if (complain & tf_error)
4199 permerror (input_location, "ISO C++ forbids comparison between pointer and integer");
4200 else
4201 return error_mark_node;
4202 }
4203 break;
4204
4205 case UNORDERED_EXPR:
4206 case ORDERED_EXPR:
4207 case UNLT_EXPR:
4208 case UNLE_EXPR:
4209 case UNGT_EXPR:
4210 case UNGE_EXPR:
4211 case UNEQ_EXPR:
4212 build_type = integer_type_node;
4213 if (code0 != REAL_TYPE || code1 != REAL_TYPE)
4214 {
4215 if (complain & tf_error)
4216 error ("unordered comparison on non-floating point argument");
4217 return error_mark_node;
4218 }
4219 common = 1;
4220 break;
4221
4222 default:
4223 break;
4224 }
4225
4226 if (((code0 == INTEGER_TYPE || code0 == REAL_TYPE || code0 == COMPLEX_TYPE
4227 || code0 == ENUMERAL_TYPE)
4228 && (code1 == INTEGER_TYPE || code1 == REAL_TYPE
4229 || code1 == COMPLEX_TYPE || code1 == ENUMERAL_TYPE)))
4230 arithmetic_types_p = 1;
4231 else
4232 {
4233 arithmetic_types_p = 0;
4234 /* Vector arithmetic is only allowed when both sides are vectors. */
4235 if (code0 == VECTOR_TYPE && code1 == VECTOR_TYPE)
4236 {
4237 if (!tree_int_cst_equal (TYPE_SIZE (type0), TYPE_SIZE (type1))
4238 || !same_scalar_type_ignoring_signedness (TREE_TYPE (type0),
4239 TREE_TYPE (type1)))
4240 {
4241 binary_op_error (location, code, type0, type1);
4242 return error_mark_node;
4243 }
4244 arithmetic_types_p = 1;
4245 }
4246 }
4247 /* Determine the RESULT_TYPE, if it is not already known. */
4248 if (!result_type
4249 && arithmetic_types_p
4250 && (shorten || common || short_compare))
4251 {
4252 result_type = cp_common_type (type0, type1);
4253 do_warn_double_promotion (result_type, type0, type1,
4254 "implicit conversion from %qT to %qT "
4255 "to match other operand of binary "
4256 "expression",
4257 location);
4258 }
4259
4260 if (!result_type)
4261 {
4262 if (complain & tf_error)
4263 error ("invalid operands of types %qT and %qT to binary %qO",
4264 TREE_TYPE (orig_op0), TREE_TYPE (orig_op1), code);
4265 return error_mark_node;
4266 }
4267
4268 /* If we're in a template, the only thing we need to know is the
4269 RESULT_TYPE. */
4270 if (processing_template_decl)
4271 {
4272 /* Since the middle-end checks the type when doing a build2, we
4273 need to build the tree in pieces. This built tree will never
4274 get out of the front-end as we replace it when instantiating
4275 the template. */
4276 tree tmp = build2 (resultcode,
4277 build_type ? build_type : result_type,
4278 NULL_TREE, op1);
4279 TREE_OPERAND (tmp, 0) = op0;
4280 return tmp;
4281 }
4282
4283 if (arithmetic_types_p)
4284 {
4285 bool first_complex = (code0 == COMPLEX_TYPE);
4286 bool second_complex = (code1 == COMPLEX_TYPE);
4287 int none_complex = (!first_complex && !second_complex);
4288
4289 /* Adapted from patch for c/24581. */
4290 if (first_complex != second_complex
4291 && (code == PLUS_EXPR
4292 || code == MINUS_EXPR
4293 || code == MULT_EXPR
4294 || (code == TRUNC_DIV_EXPR && first_complex))
4295 && TREE_CODE (TREE_TYPE (result_type)) == REAL_TYPE
4296 && flag_signed_zeros)
4297 {
4298 /* An operation on mixed real/complex operands must be
4299 handled specially, but the language-independent code can
4300 more easily optimize the plain complex arithmetic if
4301 -fno-signed-zeros. */
4302 tree real_type = TREE_TYPE (result_type);
4303 tree real, imag;
4304 if (first_complex)
4305 {
4306 if (TREE_TYPE (op0) != result_type)
4307 op0 = cp_convert_and_check (result_type, op0);
4308 if (TREE_TYPE (op1) != real_type)
4309 op1 = cp_convert_and_check (real_type, op1);
4310 }
4311 else
4312 {
4313 if (TREE_TYPE (op0) != real_type)
4314 op0 = cp_convert_and_check (real_type, op0);
4315 if (TREE_TYPE (op1) != result_type)
4316 op1 = cp_convert_and_check (result_type, op1);
4317 }
4318 if (TREE_CODE (op0) == ERROR_MARK || TREE_CODE (op1) == ERROR_MARK)
4319 return error_mark_node;
4320 if (first_complex)
4321 {
4322 op0 = save_expr (op0);
4323 real = cp_build_unary_op (REALPART_EXPR, op0, 1, complain);
4324 imag = cp_build_unary_op (IMAGPART_EXPR, op0, 1, complain);
4325 switch (code)
4326 {
4327 case MULT_EXPR:
4328 case TRUNC_DIV_EXPR:
4329 imag = build2 (resultcode, real_type, imag, op1);
4330 /* Fall through. */
4331 case PLUS_EXPR:
4332 case MINUS_EXPR:
4333 real = build2 (resultcode, real_type, real, op1);
4334 break;
4335 default:
4336 gcc_unreachable();
4337 }
4338 }
4339 else
4340 {
4341 op1 = save_expr (op1);
4342 real = cp_build_unary_op (REALPART_EXPR, op1, 1, complain);
4343 imag = cp_build_unary_op (IMAGPART_EXPR, op1, 1, complain);
4344 switch (code)
4345 {
4346 case MULT_EXPR:
4347 imag = build2 (resultcode, real_type, op0, imag);
4348 /* Fall through. */
4349 case PLUS_EXPR:
4350 real = build2 (resultcode, real_type, op0, real);
4351 break;
4352 case MINUS_EXPR:
4353 real = build2 (resultcode, real_type, op0, real);
4354 imag = build1 (NEGATE_EXPR, real_type, imag);
4355 break;
4356 default:
4357 gcc_unreachable();
4358 }
4359 }
4360 return build2 (COMPLEX_EXPR, result_type, real, imag);
4361 }
4362
4363 /* For certain operations (which identify themselves by shorten != 0)
4364 if both args were extended from the same smaller type,
4365 do the arithmetic in that type and then extend.
4366
4367 shorten !=0 and !=1 indicates a bitwise operation.
4368 For them, this optimization is safe only if
4369 both args are zero-extended or both are sign-extended.
4370 Otherwise, we might change the result.
4371 E.g., (short)-1 | (unsigned short)-1 is (int)-1
4372 but calculated in (unsigned short) it would be (unsigned short)-1. */
4373
4374 if (shorten && none_complex)
4375 {
4376 final_type = result_type;
4377 result_type = shorten_binary_op (result_type, op0, op1,
4378 shorten == -1);
4379 }
4380
4381 /* Comparison operations are shortened too but differently.
4382 They identify themselves by setting short_compare = 1. */
4383
4384 if (short_compare)
4385 {
4386 /* Don't write &op0, etc., because that would prevent op0
4387 from being kept in a register.
4388 Instead, make copies of the our local variables and
4389 pass the copies by reference, then copy them back afterward. */
4390 tree xop0 = op0, xop1 = op1, xresult_type = result_type;
4391 enum tree_code xresultcode = resultcode;
4392 tree val
4393 = shorten_compare (&xop0, &xop1, &xresult_type, &xresultcode);
4394 if (val != 0)
4395 return cp_convert (boolean_type_node, val);
4396 op0 = xop0, op1 = xop1;
4397 converted = 1;
4398 resultcode = xresultcode;
4399 }
4400
4401 if ((short_compare || code == MIN_EXPR || code == MAX_EXPR)
4402 && warn_sign_compare
4403 && !TREE_NO_WARNING (orig_op0)
4404 && !TREE_NO_WARNING (orig_op1)
4405 /* Do not warn until the template is instantiated; we cannot
4406 bound the ranges of the arguments until that point. */
4407 && !processing_template_decl
4408 && (complain & tf_warning)
4409 && c_inhibit_evaluation_warnings == 0)
4410 {
4411 warn_for_sign_compare (location, orig_op0, orig_op1, op0, op1,
4412 result_type, resultcode);
4413 }
4414 }
4415
4416 /* If CONVERTED is zero, both args will be converted to type RESULT_TYPE.
4417 Then the expression will be built.
4418 It will be given type FINAL_TYPE if that is nonzero;
4419 otherwise, it will be given type RESULT_TYPE. */
4420 if (! converted)
4421 {
4422 if (TREE_TYPE (op0) != result_type)
4423 op0 = cp_convert_and_check (result_type, op0);
4424 if (TREE_TYPE (op1) != result_type)
4425 op1 = cp_convert_and_check (result_type, op1);
4426
4427 if (op0 == error_mark_node || op1 == error_mark_node)
4428 return error_mark_node;
4429 }
4430
4431 if (build_type == NULL_TREE)
4432 build_type = result_type;
4433
4434 result = build2 (resultcode, build_type, op0, op1);
4435 result = fold_if_not_in_template (result);
4436 if (final_type != 0)
4437 result = cp_convert (final_type, result);
4438
4439 if (TREE_OVERFLOW_P (result)
4440 && !TREE_OVERFLOW_P (op0)
4441 && !TREE_OVERFLOW_P (op1))
4442 overflow_warning (location, result);
4443
4444 return result;
4445 }
4446 \f
4447 /* Return a tree for the sum or difference (RESULTCODE says which)
4448 of pointer PTROP and integer INTOP. */
4449
4450 static tree
4451 cp_pointer_int_sum (enum tree_code resultcode, tree ptrop, tree intop)
4452 {
4453 tree res_type = TREE_TYPE (ptrop);
4454
4455 /* pointer_int_sum() uses size_in_bytes() on the TREE_TYPE(res_type)
4456 in certain circumstance (when it's valid to do so). So we need
4457 to make sure it's complete. We don't need to check here, if we
4458 can actually complete it at all, as those checks will be done in
4459 pointer_int_sum() anyway. */
4460 complete_type (TREE_TYPE (res_type));
4461
4462 return pointer_int_sum (input_location, resultcode, ptrop,
4463 fold_if_not_in_template (intop));
4464 }
4465
4466 /* Return a tree for the difference of pointers OP0 and OP1.
4467 The resulting tree has type int. */
4468
4469 static tree
4470 pointer_diff (tree op0, tree op1, tree ptrtype)
4471 {
4472 tree result;
4473 tree restype = ptrdiff_type_node;
4474 tree target_type = TREE_TYPE (ptrtype);
4475
4476 if (!complete_type_or_else (target_type, NULL_TREE))
4477 return error_mark_node;
4478
4479 if (TREE_CODE (target_type) == VOID_TYPE)
4480 permerror (input_location, "ISO C++ forbids using pointer of type %<void *%> in subtraction");
4481 if (TREE_CODE (target_type) == FUNCTION_TYPE)
4482 permerror (input_location, "ISO C++ forbids using pointer to a function in subtraction");
4483 if (TREE_CODE (target_type) == METHOD_TYPE)
4484 permerror (input_location, "ISO C++ forbids using pointer to a method in subtraction");
4485
4486 /* First do the subtraction as integers;
4487 then drop through to build the divide operator. */
4488
4489 op0 = cp_build_binary_op (input_location,
4490 MINUS_EXPR,
4491 cp_convert (restype, op0),
4492 cp_convert (restype, op1),
4493 tf_warning_or_error);
4494
4495 /* This generates an error if op1 is a pointer to an incomplete type. */
4496 if (!COMPLETE_TYPE_P (TREE_TYPE (TREE_TYPE (op1))))
4497 error ("invalid use of a pointer to an incomplete type in pointer arithmetic");
4498
4499 op1 = (TYPE_PTROB_P (ptrtype)
4500 ? size_in_bytes (target_type)
4501 : integer_one_node);
4502
4503 /* Do the division. */
4504
4505 result = build2 (EXACT_DIV_EXPR, restype, op0, cp_convert (restype, op1));
4506 return fold_if_not_in_template (result);
4507 }
4508 \f
4509 /* Construct and perhaps optimize a tree representation
4510 for a unary operation. CODE, a tree_code, specifies the operation
4511 and XARG is the operand. */
4512
4513 tree
4514 build_x_unary_op (enum tree_code code, tree xarg, tsubst_flags_t complain)
4515 {
4516 tree orig_expr = xarg;
4517 tree exp;
4518 int ptrmem = 0;
4519
4520 if (processing_template_decl)
4521 {
4522 if (type_dependent_expression_p (xarg))
4523 return build_min_nt (code, xarg, NULL_TREE);
4524
4525 xarg = build_non_dependent_expr (xarg);
4526 }
4527
4528 exp = NULL_TREE;
4529
4530 /* [expr.unary.op] says:
4531
4532 The address of an object of incomplete type can be taken.
4533
4534 (And is just the ordinary address operator, not an overloaded
4535 "operator &".) However, if the type is a template
4536 specialization, we must complete the type at this point so that
4537 an overloaded "operator &" will be available if required. */
4538 if (code == ADDR_EXPR
4539 && TREE_CODE (xarg) != TEMPLATE_ID_EXPR
4540 && ((CLASS_TYPE_P (TREE_TYPE (xarg))
4541 && !COMPLETE_TYPE_P (complete_type (TREE_TYPE (xarg))))
4542 || (TREE_CODE (xarg) == OFFSET_REF)))
4543 /* Don't look for a function. */;
4544 else
4545 exp = build_new_op (code, LOOKUP_NORMAL, xarg, NULL_TREE, NULL_TREE,
4546 /*overloaded_p=*/NULL, complain);
4547 if (!exp && code == ADDR_EXPR)
4548 {
4549 if (is_overloaded_fn (xarg))
4550 {
4551 tree fn = get_first_fn (xarg);
4552 if (DECL_CONSTRUCTOR_P (fn) || DECL_DESTRUCTOR_P (fn))
4553 {
4554 error (DECL_CONSTRUCTOR_P (fn)
4555 ? G_("taking address of constructor %qE")
4556 : G_("taking address of destructor %qE"),
4557 xarg);
4558 return error_mark_node;
4559 }
4560 }
4561
4562 /* A pointer to member-function can be formed only by saying
4563 &X::mf. */
4564 if (!flag_ms_extensions && TREE_CODE (TREE_TYPE (xarg)) == METHOD_TYPE
4565 && (TREE_CODE (xarg) != OFFSET_REF || !PTRMEM_OK_P (xarg)))
4566 {
4567 if (TREE_CODE (xarg) != OFFSET_REF
4568 || !TYPE_P (TREE_OPERAND (xarg, 0)))
4569 {
4570 error ("invalid use of %qE to form a pointer-to-member-function",
4571 xarg);
4572 if (TREE_CODE (xarg) != OFFSET_REF)
4573 inform (input_location, " a qualified-id is required");
4574 return error_mark_node;
4575 }
4576 else
4577 {
4578 error ("parentheses around %qE cannot be used to form a"
4579 " pointer-to-member-function",
4580 xarg);
4581 PTRMEM_OK_P (xarg) = 1;
4582 }
4583 }
4584
4585 if (TREE_CODE (xarg) == OFFSET_REF)
4586 {
4587 ptrmem = PTRMEM_OK_P (xarg);
4588
4589 if (!ptrmem && !flag_ms_extensions
4590 && TREE_CODE (TREE_TYPE (TREE_OPERAND (xarg, 1))) == METHOD_TYPE)
4591 {
4592 /* A single non-static member, make sure we don't allow a
4593 pointer-to-member. */
4594 xarg = build2 (OFFSET_REF, TREE_TYPE (xarg),
4595 TREE_OPERAND (xarg, 0),
4596 ovl_cons (TREE_OPERAND (xarg, 1), NULL_TREE));
4597 PTRMEM_OK_P (xarg) = ptrmem;
4598 }
4599 }
4600
4601 exp = cp_build_addr_expr_strict (xarg, complain);
4602 }
4603
4604 if (processing_template_decl && exp != error_mark_node)
4605 exp = build_min_non_dep (code, exp, orig_expr,
4606 /*For {PRE,POST}{INC,DEC}REMENT_EXPR*/NULL_TREE);
4607 if (TREE_CODE (exp) == ADDR_EXPR)
4608 PTRMEM_OK_P (exp) = ptrmem;
4609 return exp;
4610 }
4611
4612 /* Like c_common_truthvalue_conversion, but handle pointer-to-member
4613 constants, where a null value is represented by an INTEGER_CST of
4614 -1. */
4615
4616 tree
4617 cp_truthvalue_conversion (tree expr)
4618 {
4619 tree type = TREE_TYPE (expr);
4620 if (TYPE_PTRMEM_P (type))
4621 return build_binary_op (EXPR_LOCATION (expr),
4622 NE_EXPR, expr, integer_zero_node, 1);
4623 else
4624 return c_common_truthvalue_conversion (input_location, expr);
4625 }
4626
4627 /* Just like cp_truthvalue_conversion, but we want a CLEANUP_POINT_EXPR. */
4628
4629 tree
4630 condition_conversion (tree expr)
4631 {
4632 tree t;
4633 if (processing_template_decl)
4634 return expr;
4635 t = perform_implicit_conversion_flags (boolean_type_node, expr,
4636 tf_warning_or_error, LOOKUP_NORMAL);
4637 t = fold_build_cleanup_point_expr (boolean_type_node, t);
4638 return t;
4639 }
4640
4641 /* Returns the address of T. This function will fold away
4642 ADDR_EXPR of INDIRECT_REF. */
4643
4644 tree
4645 build_address (tree t)
4646 {
4647 if (error_operand_p (t) || !cxx_mark_addressable (t))
4648 return error_mark_node;
4649 t = build_fold_addr_expr (t);
4650 if (TREE_CODE (t) != ADDR_EXPR)
4651 t = rvalue (t);
4652 return t;
4653 }
4654
4655 /* Returns the address of T with type TYPE. */
4656
4657 tree
4658 build_typed_address (tree t, tree type)
4659 {
4660 if (error_operand_p (t) || !cxx_mark_addressable (t))
4661 return error_mark_node;
4662 t = build_fold_addr_expr_with_type (t, type);
4663 if (TREE_CODE (t) != ADDR_EXPR)
4664 t = rvalue (t);
4665 return t;
4666 }
4667
4668 /* Return a NOP_EXPR converting EXPR to TYPE. */
4669
4670 tree
4671 build_nop (tree type, tree expr)
4672 {
4673 if (type == error_mark_node || error_operand_p (expr))
4674 return expr;
4675 return build1 (NOP_EXPR, type, expr);
4676 }
4677
4678 /* Take the address of ARG, whatever that means under C++ semantics.
4679 If STRICT_LVALUE is true, require an lvalue; otherwise, allow xvalues
4680 and class rvalues as well.
4681
4682 Nothing should call this function directly; instead, callers should use
4683 cp_build_addr_expr or cp_build_addr_expr_strict. */
4684
4685 static tree
4686 cp_build_addr_expr_1 (tree arg, bool strict_lvalue, tsubst_flags_t complain)
4687 {
4688 tree argtype;
4689 tree val;
4690
4691 if (!arg || error_operand_p (arg))
4692 return error_mark_node;
4693
4694 arg = mark_lvalue_use (arg);
4695 argtype = lvalue_type (arg);
4696
4697 gcc_assert (TREE_CODE (arg) != IDENTIFIER_NODE
4698 || !IDENTIFIER_OPNAME_P (arg));
4699
4700 if (TREE_CODE (arg) == COMPONENT_REF && type_unknown_p (arg)
4701 && !really_overloaded_fn (TREE_OPERAND (arg, 1)))
4702 {
4703 /* They're trying to take the address of a unique non-static
4704 member function. This is ill-formed (except in MS-land),
4705 but let's try to DTRT.
4706 Note: We only handle unique functions here because we don't
4707 want to complain if there's a static overload; non-unique
4708 cases will be handled by instantiate_type. But we need to
4709 handle this case here to allow casts on the resulting PMF.
4710 We could defer this in non-MS mode, but it's easier to give
4711 a useful error here. */
4712
4713 /* Inside constant member functions, the `this' pointer
4714 contains an extra const qualifier. TYPE_MAIN_VARIANT
4715 is used here to remove this const from the diagnostics
4716 and the created OFFSET_REF. */
4717 tree base = TYPE_MAIN_VARIANT (TREE_TYPE (TREE_OPERAND (arg, 0)));
4718 tree fn = get_first_fn (TREE_OPERAND (arg, 1));
4719 mark_used (fn);
4720
4721 if (! flag_ms_extensions)
4722 {
4723 tree name = DECL_NAME (fn);
4724 if (!(complain & tf_error))
4725 return error_mark_node;
4726 else if (current_class_type
4727 && TREE_OPERAND (arg, 0) == current_class_ref)
4728 /* An expression like &memfn. */
4729 permerror (input_location, "ISO C++ forbids taking the address of an unqualified"
4730 " or parenthesized non-static member function to form"
4731 " a pointer to member function. Say %<&%T::%D%>",
4732 base, name);
4733 else
4734 permerror (input_location, "ISO C++ forbids taking the address of a bound member"
4735 " function to form a pointer to member function."
4736 " Say %<&%T::%D%>",
4737 base, name);
4738 }
4739 arg = build_offset_ref (base, fn, /*address_p=*/true);
4740 }
4741
4742 /* Uninstantiated types are all functions. Taking the
4743 address of a function is a no-op, so just return the
4744 argument. */
4745 if (type_unknown_p (arg))
4746 return build1 (ADDR_EXPR, unknown_type_node, arg);
4747
4748 if (TREE_CODE (arg) == OFFSET_REF)
4749 /* We want a pointer to member; bypass all the code for actually taking
4750 the address of something. */
4751 goto offset_ref;
4752
4753 /* Anything not already handled and not a true memory reference
4754 is an error. */
4755 if (TREE_CODE (argtype) != FUNCTION_TYPE
4756 && TREE_CODE (argtype) != METHOD_TYPE)
4757 {
4758 cp_lvalue_kind kind = lvalue_kind (arg);
4759 if (kind == clk_none)
4760 {
4761 if (complain & tf_error)
4762 lvalue_error (input_location, lv_addressof);
4763 return error_mark_node;
4764 }
4765 if (strict_lvalue && (kind & (clk_rvalueref|clk_class)))
4766 {
4767 if (!(complain & tf_error))
4768 return error_mark_node;
4769 if (kind & clk_class)
4770 /* Make this a permerror because we used to accept it. */
4771 permerror (input_location, "taking address of temporary");
4772 else
4773 error ("taking address of xvalue (rvalue reference)");
4774 }
4775 }
4776
4777 if (TREE_CODE (argtype) == REFERENCE_TYPE)
4778 {
4779 tree type = build_pointer_type (TREE_TYPE (argtype));
4780 arg = build1 (CONVERT_EXPR, type, arg);
4781 return arg;
4782 }
4783 else if (pedantic && DECL_MAIN_P (arg))
4784 {
4785 /* ARM $3.4 */
4786 /* Apparently a lot of autoconf scripts for C++ packages do this,
4787 so only complain if -pedantic. */
4788 if (complain & (flag_pedantic_errors ? tf_error : tf_warning))
4789 pedwarn (input_location, OPT_pedantic,
4790 "ISO C++ forbids taking address of function %<::main%>");
4791 else if (flag_pedantic_errors)
4792 return error_mark_node;
4793 }
4794
4795 /* Let &* cancel out to simplify resulting code. */
4796 if (TREE_CODE (arg) == INDIRECT_REF)
4797 {
4798 /* We don't need to have `current_class_ptr' wrapped in a
4799 NON_LVALUE_EXPR node. */
4800 if (arg == current_class_ref)
4801 return current_class_ptr;
4802
4803 arg = TREE_OPERAND (arg, 0);
4804 if (TREE_CODE (TREE_TYPE (arg)) == REFERENCE_TYPE)
4805 {
4806 tree type = build_pointer_type (TREE_TYPE (TREE_TYPE (arg)));
4807 arg = build1 (CONVERT_EXPR, type, arg);
4808 }
4809 else
4810 /* Don't let this be an lvalue. */
4811 arg = rvalue (arg);
4812 return arg;
4813 }
4814
4815 /* ??? Cope with user tricks that amount to offsetof. */
4816 if (TREE_CODE (argtype) != FUNCTION_TYPE
4817 && TREE_CODE (argtype) != METHOD_TYPE
4818 && argtype != unknown_type_node
4819 && (val = get_base_address (arg))
4820 && COMPLETE_TYPE_P (TREE_TYPE (val))
4821 && TREE_CODE (val) == INDIRECT_REF
4822 && TREE_CONSTANT (TREE_OPERAND (val, 0)))
4823 {
4824 tree type = build_pointer_type (argtype);
4825 tree op0 = fold_convert (type, TREE_OPERAND (val, 0));
4826 tree op1 = fold_convert (sizetype, fold_offsetof (arg, val));
4827 return fold_build2 (POINTER_PLUS_EXPR, type, op0, op1);
4828 }
4829
4830 /* Handle complex lvalues (when permitted)
4831 by reduction to simpler cases. */
4832 val = unary_complex_lvalue (ADDR_EXPR, arg);
4833 if (val != 0)
4834 return val;
4835
4836 switch (TREE_CODE (arg))
4837 {
4838 CASE_CONVERT:
4839 case FLOAT_EXPR:
4840 case FIX_TRUNC_EXPR:
4841 /* Even if we're not being pedantic, we cannot allow this
4842 extension when we're instantiating in a SFINAE
4843 context. */
4844 if (! lvalue_p (arg) && complain == tf_none)
4845 {
4846 if (complain & tf_error)
4847 permerror (input_location, "ISO C++ forbids taking the address of a cast to a non-lvalue expression");
4848 else
4849 return error_mark_node;
4850 }
4851 break;
4852
4853 case BASELINK:
4854 arg = BASELINK_FUNCTIONS (arg);
4855 /* Fall through. */
4856
4857 case OVERLOAD:
4858 arg = OVL_CURRENT (arg);
4859 break;
4860
4861 case OFFSET_REF:
4862 offset_ref:
4863 /* Turn a reference to a non-static data member into a
4864 pointer-to-member. */
4865 {
4866 tree type;
4867 tree t;
4868
4869 gcc_assert (PTRMEM_OK_P (arg));
4870
4871 t = TREE_OPERAND (arg, 1);
4872 if (TREE_CODE (TREE_TYPE (t)) == REFERENCE_TYPE)
4873 {
4874 if (complain & tf_error)
4875 error ("cannot create pointer to reference member %qD", t);
4876 return error_mark_node;
4877 }
4878
4879 type = build_ptrmem_type (context_for_name_lookup (t),
4880 TREE_TYPE (t));
4881 t = make_ptrmem_cst (type, TREE_OPERAND (arg, 1));
4882 return t;
4883 }
4884
4885 default:
4886 break;
4887 }
4888
4889 if (argtype != error_mark_node)
4890 argtype = build_pointer_type (argtype);
4891
4892 /* In a template, we are processing a non-dependent expression
4893 so we can just form an ADDR_EXPR with the correct type. */
4894 if (processing_template_decl || TREE_CODE (arg) != COMPONENT_REF)
4895 {
4896 val = build_address (arg);
4897 if (TREE_CODE (arg) == OFFSET_REF)
4898 PTRMEM_OK_P (val) = PTRMEM_OK_P (arg);
4899 }
4900 else if (TREE_CODE (TREE_OPERAND (arg, 1)) == BASELINK)
4901 {
4902 tree fn = BASELINK_FUNCTIONS (TREE_OPERAND (arg, 1));
4903
4904 /* We can only get here with a single static member
4905 function. */
4906 gcc_assert (TREE_CODE (fn) == FUNCTION_DECL
4907 && DECL_STATIC_FUNCTION_P (fn));
4908 mark_used (fn);
4909 val = build_address (fn);
4910 if (TREE_SIDE_EFFECTS (TREE_OPERAND (arg, 0)))
4911 /* Do not lose object's side effects. */
4912 val = build2 (COMPOUND_EXPR, TREE_TYPE (val),
4913 TREE_OPERAND (arg, 0), val);
4914 }
4915 else if (DECL_C_BIT_FIELD (TREE_OPERAND (arg, 1)))
4916 {
4917 if (complain & tf_error)
4918 error ("attempt to take address of bit-field structure member %qD",
4919 TREE_OPERAND (arg, 1));
4920 return error_mark_node;
4921 }
4922 else
4923 {
4924 tree object = TREE_OPERAND (arg, 0);
4925 tree field = TREE_OPERAND (arg, 1);
4926 gcc_assert (same_type_ignoring_top_level_qualifiers_p
4927 (TREE_TYPE (object), decl_type_context (field)));
4928 val = build_address (arg);
4929 }
4930
4931 if (TREE_CODE (argtype) == POINTER_TYPE
4932 && TREE_CODE (TREE_TYPE (argtype)) == METHOD_TYPE)
4933 {
4934 build_ptrmemfunc_type (argtype);
4935 val = build_ptrmemfunc (argtype, val, 0,
4936 /*c_cast_p=*/false,
4937 tf_warning_or_error);
4938 }
4939
4940 return val;
4941 }
4942
4943 /* Take the address of ARG if it has one, even if it's an rvalue. */
4944
4945 tree
4946 cp_build_addr_expr (tree arg, tsubst_flags_t complain)
4947 {
4948 return cp_build_addr_expr_1 (arg, 0, complain);
4949 }
4950
4951 /* Take the address of ARG, but only if it's an lvalue. */
4952
4953 tree
4954 cp_build_addr_expr_strict (tree arg, tsubst_flags_t complain)
4955 {
4956 return cp_build_addr_expr_1 (arg, 1, complain);
4957 }
4958
4959 /* C++: Must handle pointers to members.
4960
4961 Perhaps type instantiation should be extended to handle conversion
4962 from aggregates to types we don't yet know we want? (Or are those
4963 cases typically errors which should be reported?)
4964
4965 NOCONVERT nonzero suppresses the default promotions
4966 (such as from short to int). */
4967
4968 tree
4969 cp_build_unary_op (enum tree_code code, tree xarg, int noconvert,
4970 tsubst_flags_t complain)
4971 {
4972 /* No default_conversion here. It causes trouble for ADDR_EXPR. */
4973 tree arg = xarg;
4974 tree argtype = 0;
4975 const char *errstring = NULL;
4976 tree val;
4977 const char *invalid_op_diag;
4978
4979 if (!arg || error_operand_p (arg))
4980 return error_mark_node;
4981
4982 if ((invalid_op_diag
4983 = targetm.invalid_unary_op ((code == UNARY_PLUS_EXPR
4984 ? CONVERT_EXPR
4985 : code),
4986 TREE_TYPE (xarg))))
4987 {
4988 error (invalid_op_diag);
4989 return error_mark_node;
4990 }
4991
4992 switch (code)
4993 {
4994 case UNARY_PLUS_EXPR:
4995 case NEGATE_EXPR:
4996 {
4997 int flags = WANT_ARITH | WANT_ENUM;
4998 /* Unary plus (but not unary minus) is allowed on pointers. */
4999 if (code == UNARY_PLUS_EXPR)
5000 flags |= WANT_POINTER;
5001 arg = build_expr_type_conversion (flags, arg, true);
5002 if (!arg)
5003 errstring = (code == NEGATE_EXPR
5004 ? _("wrong type argument to unary minus")
5005 : _("wrong type argument to unary plus"));
5006 else
5007 {
5008 if (!noconvert && CP_INTEGRAL_TYPE_P (TREE_TYPE (arg)))
5009 arg = perform_integral_promotions (arg);
5010
5011 /* Make sure the result is not an lvalue: a unary plus or minus
5012 expression is always a rvalue. */
5013 arg = rvalue (arg);
5014 }
5015 }
5016 break;
5017
5018 case BIT_NOT_EXPR:
5019 if (TREE_CODE (TREE_TYPE (arg)) == COMPLEX_TYPE)
5020 {
5021 code = CONJ_EXPR;
5022 if (!noconvert)
5023 arg = default_conversion (arg);
5024 }
5025 else if (!(arg = build_expr_type_conversion (WANT_INT | WANT_ENUM
5026 | WANT_VECTOR_OR_COMPLEX,
5027 arg, true)))
5028 errstring = _("wrong type argument to bit-complement");
5029 else if (!noconvert && CP_INTEGRAL_TYPE_P (TREE_TYPE (arg)))
5030 arg = perform_integral_promotions (arg);
5031 break;
5032
5033 case ABS_EXPR:
5034 if (!(arg = build_expr_type_conversion (WANT_ARITH | WANT_ENUM, arg, true)))
5035 errstring = _("wrong type argument to abs");
5036 else if (!noconvert)
5037 arg = default_conversion (arg);
5038 break;
5039
5040 case CONJ_EXPR:
5041 /* Conjugating a real value is a no-op, but allow it anyway. */
5042 if (!(arg = build_expr_type_conversion (WANT_ARITH | WANT_ENUM, arg, true)))
5043 errstring = _("wrong type argument to conjugation");
5044 else if (!noconvert)
5045 arg = default_conversion (arg);
5046 break;
5047
5048 case TRUTH_NOT_EXPR:
5049 arg = perform_implicit_conversion (boolean_type_node, arg,
5050 complain);
5051 val = invert_truthvalue_loc (input_location, arg);
5052 if (arg != error_mark_node)
5053 return val;
5054 errstring = _("in argument to unary !");
5055 break;
5056
5057 case NOP_EXPR:
5058 break;
5059
5060 case REALPART_EXPR:
5061 case IMAGPART_EXPR:
5062 arg = build_real_imag_expr (input_location, code, arg);
5063 if (arg == error_mark_node)
5064 return arg;
5065 else
5066 return fold_if_not_in_template (arg);
5067
5068 case PREINCREMENT_EXPR:
5069 case POSTINCREMENT_EXPR:
5070 case PREDECREMENT_EXPR:
5071 case POSTDECREMENT_EXPR:
5072 /* Handle complex lvalues (when permitted)
5073 by reduction to simpler cases. */
5074
5075 val = unary_complex_lvalue (code, arg);
5076 if (val != 0)
5077 return val;
5078
5079 arg = mark_lvalue_use (arg);
5080
5081 /* Increment or decrement the real part of the value,
5082 and don't change the imaginary part. */
5083 if (TREE_CODE (TREE_TYPE (arg)) == COMPLEX_TYPE)
5084 {
5085 tree real, imag;
5086
5087 arg = stabilize_reference (arg);
5088 real = cp_build_unary_op (REALPART_EXPR, arg, 1, complain);
5089 imag = cp_build_unary_op (IMAGPART_EXPR, arg, 1, complain);
5090 real = cp_build_unary_op (code, real, 1, complain);
5091 if (real == error_mark_node || imag == error_mark_node)
5092 return error_mark_node;
5093 return build2 (COMPLEX_EXPR, TREE_TYPE (arg),
5094 real, imag);
5095 }
5096
5097 /* Report invalid types. */
5098
5099 if (!(arg = build_expr_type_conversion (WANT_ARITH | WANT_POINTER,
5100 arg, true)))
5101 {
5102 if (code == PREINCREMENT_EXPR)
5103 errstring = _("no pre-increment operator for type");
5104 else if (code == POSTINCREMENT_EXPR)
5105 errstring = _("no post-increment operator for type");
5106 else if (code == PREDECREMENT_EXPR)
5107 errstring = _("no pre-decrement operator for type");
5108 else
5109 errstring = _("no post-decrement operator for type");
5110 break;
5111 }
5112 else if (arg == error_mark_node)
5113 return error_mark_node;
5114
5115 /* Report something read-only. */
5116
5117 if (CP_TYPE_CONST_P (TREE_TYPE (arg))
5118 || TREE_READONLY (arg))
5119 {
5120 if (complain & tf_error)
5121 cxx_readonly_error (arg, ((code == PREINCREMENT_EXPR
5122 || code == POSTINCREMENT_EXPR)
5123 ? lv_increment : lv_decrement));
5124 else
5125 return error_mark_node;
5126 }
5127
5128 {
5129 tree inc;
5130 tree declared_type = unlowered_expr_type (arg);
5131
5132 argtype = TREE_TYPE (arg);
5133
5134 /* ARM $5.2.5 last annotation says this should be forbidden. */
5135 if (TREE_CODE (argtype) == ENUMERAL_TYPE)
5136 {
5137 if (complain & tf_error)
5138 permerror (input_location, (code == PREINCREMENT_EXPR || code == POSTINCREMENT_EXPR)
5139 ? G_("ISO C++ forbids incrementing an enum")
5140 : G_("ISO C++ forbids decrementing an enum"));
5141 else
5142 return error_mark_node;
5143 }
5144
5145 /* Compute the increment. */
5146
5147 if (TREE_CODE (argtype) == POINTER_TYPE)
5148 {
5149 tree type = complete_type (TREE_TYPE (argtype));
5150
5151 if (!COMPLETE_OR_VOID_TYPE_P (type))
5152 {
5153 if (complain & tf_error)
5154 error (((code == PREINCREMENT_EXPR
5155 || code == POSTINCREMENT_EXPR))
5156 ? G_("cannot increment a pointer to incomplete type %qT")
5157 : G_("cannot decrement a pointer to incomplete type %qT"),
5158 TREE_TYPE (argtype));
5159 else
5160 return error_mark_node;
5161 }
5162 else if ((pedantic || warn_pointer_arith)
5163 && !TYPE_PTROB_P (argtype))
5164 {
5165 if (complain & tf_error)
5166 permerror (input_location, (code == PREINCREMENT_EXPR
5167 || code == POSTINCREMENT_EXPR)
5168 ? G_("ISO C++ forbids incrementing a pointer of type %qT")
5169 : G_("ISO C++ forbids decrementing a pointer of type %qT"),
5170 argtype);
5171 else
5172 return error_mark_node;
5173 }
5174
5175 inc = cxx_sizeof_nowarn (TREE_TYPE (argtype));
5176 }
5177 else
5178 inc = integer_one_node;
5179
5180 inc = cp_convert (argtype, inc);
5181
5182 /* If 'arg' is an Objective-C PROPERTY_REF expression, then we
5183 need to ask Objective-C to build the increment or decrement
5184 expression for it. */
5185 if (objc_is_property_ref (arg))
5186 return objc_build_incr_expr_for_property_ref (input_location, code,
5187 arg, inc);
5188
5189 /* Complain about anything else that is not a true lvalue. */
5190 if (!lvalue_or_else (arg, ((code == PREINCREMENT_EXPR
5191 || code == POSTINCREMENT_EXPR)
5192 ? lv_increment : lv_decrement),
5193 complain))
5194 return error_mark_node;
5195
5196 /* Forbid using -- on `bool'. */
5197 if (TREE_CODE (declared_type) == BOOLEAN_TYPE)
5198 {
5199 if (code == POSTDECREMENT_EXPR || code == PREDECREMENT_EXPR)
5200 {
5201 if (complain & tf_error)
5202 error ("invalid use of Boolean expression as operand "
5203 "to %<operator--%>");
5204 return error_mark_node;
5205 }
5206 val = boolean_increment (code, arg);
5207 }
5208 else
5209 val = build2 (code, TREE_TYPE (arg), arg, inc);
5210
5211 TREE_SIDE_EFFECTS (val) = 1;
5212 return val;
5213 }
5214
5215 case ADDR_EXPR:
5216 /* Note that this operation never does default_conversion
5217 regardless of NOCONVERT. */
5218 return cp_build_addr_expr (arg, complain);
5219
5220 default:
5221 break;
5222 }
5223
5224 if (!errstring)
5225 {
5226 if (argtype == 0)
5227 argtype = TREE_TYPE (arg);
5228 return fold_if_not_in_template (build1 (code, argtype, arg));
5229 }
5230
5231 if (complain & tf_error)
5232 error ("%s", errstring);
5233 return error_mark_node;
5234 }
5235
5236 /* Hook for the c-common bits that build a unary op. */
5237 tree
5238 build_unary_op (location_t location ATTRIBUTE_UNUSED,
5239 enum tree_code code, tree xarg, int noconvert)
5240 {
5241 return cp_build_unary_op (code, xarg, noconvert, tf_warning_or_error);
5242 }
5243
5244 /* Apply unary lvalue-demanding operator CODE to the expression ARG
5245 for certain kinds of expressions which are not really lvalues
5246 but which we can accept as lvalues.
5247
5248 If ARG is not a kind of expression we can handle, return
5249 NULL_TREE. */
5250
5251 tree
5252 unary_complex_lvalue (enum tree_code code, tree arg)
5253 {
5254 /* Inside a template, making these kinds of adjustments is
5255 pointless; we are only concerned with the type of the
5256 expression. */
5257 if (processing_template_decl)
5258 return NULL_TREE;
5259
5260 /* Handle (a, b) used as an "lvalue". */
5261 if (TREE_CODE (arg) == COMPOUND_EXPR)
5262 {
5263 tree real_result = cp_build_unary_op (code, TREE_OPERAND (arg, 1), 0,
5264 tf_warning_or_error);
5265 return build2 (COMPOUND_EXPR, TREE_TYPE (real_result),
5266 TREE_OPERAND (arg, 0), real_result);
5267 }
5268
5269 /* Handle (a ? b : c) used as an "lvalue". */
5270 if (TREE_CODE (arg) == COND_EXPR
5271 || TREE_CODE (arg) == MIN_EXPR || TREE_CODE (arg) == MAX_EXPR)
5272 return rationalize_conditional_expr (code, arg, tf_warning_or_error);
5273
5274 /* Handle (a = b), (++a), and (--a) used as an "lvalue". */
5275 if (TREE_CODE (arg) == MODIFY_EXPR
5276 || TREE_CODE (arg) == PREINCREMENT_EXPR
5277 || TREE_CODE (arg) == PREDECREMENT_EXPR)
5278 {
5279 tree lvalue = TREE_OPERAND (arg, 0);
5280 if (TREE_SIDE_EFFECTS (lvalue))
5281 {
5282 lvalue = stabilize_reference (lvalue);
5283 arg = build2 (TREE_CODE (arg), TREE_TYPE (arg),
5284 lvalue, TREE_OPERAND (arg, 1));
5285 }
5286 return unary_complex_lvalue
5287 (code, build2 (COMPOUND_EXPR, TREE_TYPE (lvalue), arg, lvalue));
5288 }
5289
5290 if (code != ADDR_EXPR)
5291 return NULL_TREE;
5292
5293 /* Handle (a = b) used as an "lvalue" for `&'. */
5294 if (TREE_CODE (arg) == MODIFY_EXPR
5295 || TREE_CODE (arg) == INIT_EXPR)
5296 {
5297 tree real_result = cp_build_unary_op (code, TREE_OPERAND (arg, 0), 0,
5298 tf_warning_or_error);
5299 arg = build2 (COMPOUND_EXPR, TREE_TYPE (real_result),
5300 arg, real_result);
5301 TREE_NO_WARNING (arg) = 1;
5302 return arg;
5303 }
5304
5305 if (TREE_CODE (TREE_TYPE (arg)) == FUNCTION_TYPE
5306 || TREE_CODE (TREE_TYPE (arg)) == METHOD_TYPE
5307 || TREE_CODE (arg) == OFFSET_REF)
5308 return NULL_TREE;
5309
5310 /* We permit compiler to make function calls returning
5311 objects of aggregate type look like lvalues. */
5312 {
5313 tree targ = arg;
5314
5315 if (TREE_CODE (targ) == SAVE_EXPR)
5316 targ = TREE_OPERAND (targ, 0);
5317
5318 if (TREE_CODE (targ) == CALL_EXPR && MAYBE_CLASS_TYPE_P (TREE_TYPE (targ)))
5319 {
5320 if (TREE_CODE (arg) == SAVE_EXPR)
5321 targ = arg;
5322 else
5323 targ = build_cplus_new (TREE_TYPE (arg), arg, tf_warning_or_error);
5324 return build1 (ADDR_EXPR, build_pointer_type (TREE_TYPE (arg)), targ);
5325 }
5326
5327 if (TREE_CODE (arg) == SAVE_EXPR && TREE_CODE (targ) == INDIRECT_REF)
5328 return build3 (SAVE_EXPR, build_pointer_type (TREE_TYPE (arg)),
5329 TREE_OPERAND (targ, 0), current_function_decl, NULL);
5330 }
5331
5332 /* Don't let anything else be handled specially. */
5333 return NULL_TREE;
5334 }
5335 \f
5336 /* Mark EXP saying that we need to be able to take the
5337 address of it; it should not be allocated in a register.
5338 Value is true if successful.
5339
5340 C++: we do not allow `current_class_ptr' to be addressable. */
5341
5342 bool
5343 cxx_mark_addressable (tree exp)
5344 {
5345 tree x = exp;
5346
5347 while (1)
5348 switch (TREE_CODE (x))
5349 {
5350 case ADDR_EXPR:
5351 case COMPONENT_REF:
5352 case ARRAY_REF:
5353 case REALPART_EXPR:
5354 case IMAGPART_EXPR:
5355 x = TREE_OPERAND (x, 0);
5356 break;
5357
5358 case PARM_DECL:
5359 if (x == current_class_ptr)
5360 {
5361 error ("cannot take the address of %<this%>, which is an rvalue expression");
5362 TREE_ADDRESSABLE (x) = 1; /* so compiler doesn't die later. */
5363 return true;
5364 }
5365 /* Fall through. */
5366
5367 case VAR_DECL:
5368 /* Caller should not be trying to mark initialized
5369 constant fields addressable. */
5370 gcc_assert (DECL_LANG_SPECIFIC (x) == 0
5371 || DECL_IN_AGGR_P (x) == 0
5372 || TREE_STATIC (x)
5373 || DECL_EXTERNAL (x));
5374 /* Fall through. */
5375
5376 case CONST_DECL:
5377 case RESULT_DECL:
5378 if (DECL_REGISTER (x) && !TREE_ADDRESSABLE (x)
5379 && !DECL_ARTIFICIAL (x))
5380 {
5381 if (TREE_CODE (x) == VAR_DECL && DECL_HARD_REGISTER (x))
5382 {
5383 error
5384 ("address of explicit register variable %qD requested", x);
5385 return false;
5386 }
5387 else if (extra_warnings)
5388 warning
5389 (OPT_Wextra, "address requested for %qD, which is declared %<register%>", x);
5390 }
5391 TREE_ADDRESSABLE (x) = 1;
5392 return true;
5393
5394 case FUNCTION_DECL:
5395 TREE_ADDRESSABLE (x) = 1;
5396 return true;
5397
5398 case CONSTRUCTOR:
5399 TREE_ADDRESSABLE (x) = 1;
5400 return true;
5401
5402 case TARGET_EXPR:
5403 TREE_ADDRESSABLE (x) = 1;
5404 cxx_mark_addressable (TREE_OPERAND (x, 0));
5405 return true;
5406
5407 default:
5408 return true;
5409 }
5410 }
5411 \f
5412 /* Build and return a conditional expression IFEXP ? OP1 : OP2. */
5413
5414 tree
5415 build_x_conditional_expr (tree ifexp, tree op1, tree op2,
5416 tsubst_flags_t complain)
5417 {
5418 tree orig_ifexp = ifexp;
5419 tree orig_op1 = op1;
5420 tree orig_op2 = op2;
5421 tree expr;
5422
5423 if (processing_template_decl)
5424 {
5425 /* The standard says that the expression is type-dependent if
5426 IFEXP is type-dependent, even though the eventual type of the
5427 expression doesn't dependent on IFEXP. */
5428 if (type_dependent_expression_p (ifexp)
5429 /* As a GNU extension, the middle operand may be omitted. */
5430 || (op1 && type_dependent_expression_p (op1))
5431 || type_dependent_expression_p (op2))
5432 return build_min_nt (COND_EXPR, ifexp, op1, op2);
5433 ifexp = build_non_dependent_expr (ifexp);
5434 if (op1)
5435 op1 = build_non_dependent_expr (op1);
5436 op2 = build_non_dependent_expr (op2);
5437 }
5438
5439 expr = build_conditional_expr (ifexp, op1, op2, complain);
5440 if (processing_template_decl && expr != error_mark_node)
5441 return build_min_non_dep (COND_EXPR, expr,
5442 orig_ifexp, orig_op1, orig_op2);
5443 return expr;
5444 }
5445 \f
5446 /* Given a list of expressions, return a compound expression
5447 that performs them all and returns the value of the last of them. */
5448
5449 tree
5450 build_x_compound_expr_from_list (tree list, expr_list_kind exp,
5451 tsubst_flags_t complain)
5452 {
5453 tree expr = TREE_VALUE (list);
5454
5455 if (TREE_CHAIN (list))
5456 {
5457 if (complain & tf_error)
5458 switch (exp)
5459 {
5460 case ELK_INIT:
5461 permerror (input_location, "expression list treated as compound "
5462 "expression in initializer");
5463 break;
5464 case ELK_MEM_INIT:
5465 permerror (input_location, "expression list treated as compound "
5466 "expression in mem-initializer");
5467 break;
5468 case ELK_FUNC_CAST:
5469 permerror (input_location, "expression list treated as compound "
5470 "expression in functional cast");
5471 break;
5472 default:
5473 gcc_unreachable ();
5474 }
5475
5476 for (list = TREE_CHAIN (list); list; list = TREE_CHAIN (list))
5477 expr = build_x_compound_expr (expr, TREE_VALUE (list),
5478 complain);
5479 }
5480
5481 return expr;
5482 }
5483
5484 /* Like build_x_compound_expr_from_list, but using a VEC. */
5485
5486 tree
5487 build_x_compound_expr_from_vec (VEC(tree,gc) *vec, const char *msg)
5488 {
5489 if (VEC_empty (tree, vec))
5490 return NULL_TREE;
5491 else if (VEC_length (tree, vec) == 1)
5492 return VEC_index (tree, vec, 0);
5493 else
5494 {
5495 tree expr;
5496 unsigned int ix;
5497 tree t;
5498
5499 if (msg != NULL)
5500 permerror (input_location,
5501 "%s expression list treated as compound expression",
5502 msg);
5503
5504 expr = VEC_index (tree, vec, 0);
5505 for (ix = 1; VEC_iterate (tree, vec, ix, t); ++ix)
5506 expr = build_x_compound_expr (expr, t, tf_warning_or_error);
5507
5508 return expr;
5509 }
5510 }
5511
5512 /* Handle overloading of the ',' operator when needed. */
5513
5514 tree
5515 build_x_compound_expr (tree op1, tree op2, tsubst_flags_t complain)
5516 {
5517 tree result;
5518 tree orig_op1 = op1;
5519 tree orig_op2 = op2;
5520
5521 if (processing_template_decl)
5522 {
5523 if (type_dependent_expression_p (op1)
5524 || type_dependent_expression_p (op2))
5525 return build_min_nt (COMPOUND_EXPR, op1, op2);
5526 op1 = build_non_dependent_expr (op1);
5527 op2 = build_non_dependent_expr (op2);
5528 }
5529
5530 result = build_new_op (COMPOUND_EXPR, LOOKUP_NORMAL, op1, op2, NULL_TREE,
5531 /*overloaded_p=*/NULL, complain);
5532 if (!result)
5533 result = cp_build_compound_expr (op1, op2, complain);
5534
5535 if (processing_template_decl && result != error_mark_node)
5536 return build_min_non_dep (COMPOUND_EXPR, result, orig_op1, orig_op2);
5537
5538 return result;
5539 }
5540
5541 /* Like cp_build_compound_expr, but for the c-common bits. */
5542
5543 tree
5544 build_compound_expr (location_t loc ATTRIBUTE_UNUSED, tree lhs, tree rhs)
5545 {
5546 return cp_build_compound_expr (lhs, rhs, tf_warning_or_error);
5547 }
5548
5549 /* Build a compound expression. */
5550
5551 tree
5552 cp_build_compound_expr (tree lhs, tree rhs, tsubst_flags_t complain)
5553 {
5554 lhs = convert_to_void (lhs, ICV_LEFT_OF_COMMA, complain);
5555
5556 if (lhs == error_mark_node || rhs == error_mark_node)
5557 return error_mark_node;
5558
5559 if (TREE_CODE (rhs) == TARGET_EXPR)
5560 {
5561 /* If the rhs is a TARGET_EXPR, then build the compound
5562 expression inside the target_expr's initializer. This
5563 helps the compiler to eliminate unnecessary temporaries. */
5564 tree init = TREE_OPERAND (rhs, 1);
5565
5566 init = build2 (COMPOUND_EXPR, TREE_TYPE (init), lhs, init);
5567 TREE_OPERAND (rhs, 1) = init;
5568
5569 return rhs;
5570 }
5571
5572 if (type_unknown_p (rhs))
5573 {
5574 error ("no context to resolve type of %qE", rhs);
5575 return error_mark_node;
5576 }
5577
5578 return build2 (COMPOUND_EXPR, TREE_TYPE (rhs), lhs, rhs);
5579 }
5580
5581 /* Issue a diagnostic message if casting from SRC_TYPE to DEST_TYPE
5582 casts away constness. CAST gives the type of cast.
5583
5584 ??? This function warns for casting away any qualifier not just
5585 const. We would like to specify exactly what qualifiers are casted
5586 away.
5587 */
5588
5589 static void
5590 check_for_casting_away_constness (tree src_type, tree dest_type,
5591 enum tree_code cast)
5592 {
5593 /* C-style casts are allowed to cast away constness. With
5594 WARN_CAST_QUAL, we still want to issue a warning. */
5595 if (cast == CAST_EXPR && !warn_cast_qual)
5596 return;
5597
5598 if (!casts_away_constness (src_type, dest_type))
5599 return;
5600
5601 switch (cast)
5602 {
5603 case CAST_EXPR:
5604 warning (OPT_Wcast_qual,
5605 "cast from type %qT to type %qT casts away qualifiers",
5606 src_type, dest_type);
5607 return;
5608
5609 case STATIC_CAST_EXPR:
5610 error ("static_cast from type %qT to type %qT casts away qualifiers",
5611 src_type, dest_type);
5612 return;
5613
5614 case REINTERPRET_CAST_EXPR:
5615 error ("reinterpret_cast from type %qT to type %qT casts away qualifiers",
5616 src_type, dest_type);
5617 return;
5618 default:
5619 gcc_unreachable();
5620 }
5621 }
5622
5623 /* Convert EXPR (an expression with pointer-to-member type) to TYPE
5624 (another pointer-to-member type in the same hierarchy) and return
5625 the converted expression. If ALLOW_INVERSE_P is permitted, a
5626 pointer-to-derived may be converted to pointer-to-base; otherwise,
5627 only the other direction is permitted. If C_CAST_P is true, this
5628 conversion is taking place as part of a C-style cast. */
5629
5630 tree
5631 convert_ptrmem (tree type, tree expr, bool allow_inverse_p,
5632 bool c_cast_p, tsubst_flags_t complain)
5633 {
5634 if (TYPE_PTRMEM_P (type))
5635 {
5636 tree delta;
5637
5638 if (TREE_CODE (expr) == PTRMEM_CST)
5639 expr = cplus_expand_constant (expr);
5640 delta = get_delta_difference (TYPE_PTRMEM_CLASS_TYPE (TREE_TYPE (expr)),
5641 TYPE_PTRMEM_CLASS_TYPE (type),
5642 allow_inverse_p,
5643 c_cast_p, complain);
5644 if (delta == error_mark_node)
5645 return error_mark_node;
5646
5647 if (!integer_zerop (delta))
5648 {
5649 tree cond, op1, op2;
5650
5651 cond = cp_build_binary_op (input_location,
5652 EQ_EXPR,
5653 expr,
5654 build_int_cst (TREE_TYPE (expr), -1),
5655 tf_warning_or_error);
5656 op1 = build_nop (ptrdiff_type_node, expr);
5657 op2 = cp_build_binary_op (input_location,
5658 PLUS_EXPR, op1, delta,
5659 tf_warning_or_error);
5660
5661 expr = fold_build3_loc (input_location,
5662 COND_EXPR, ptrdiff_type_node, cond, op1, op2);
5663
5664 }
5665
5666 return build_nop (type, expr);
5667 }
5668 else
5669 return build_ptrmemfunc (TYPE_PTRMEMFUNC_FN_TYPE (type), expr,
5670 allow_inverse_p, c_cast_p, complain);
5671 }
5672
5673 /* Perform a static_cast from EXPR to TYPE. When C_CAST_P is true,
5674 this static_cast is being attempted as one of the possible casts
5675 allowed by a C-style cast. (In that case, accessibility of base
5676 classes is not considered, and it is OK to cast away
5677 constness.) Return the result of the cast. *VALID_P is set to
5678 indicate whether or not the cast was valid. */
5679
5680 static tree
5681 build_static_cast_1 (tree type, tree expr, bool c_cast_p,
5682 bool *valid_p, tsubst_flags_t complain)
5683 {
5684 tree intype;
5685 tree result;
5686
5687 /* Assume the cast is valid. */
5688 *valid_p = true;
5689
5690 intype = TREE_TYPE (expr);
5691
5692 /* Save casted types in the function's used types hash table. */
5693 used_types_insert (type);
5694
5695 /* [expr.static.cast]
5696
5697 An lvalue of type "cv1 B", where B is a class type, can be cast
5698 to type "reference to cv2 D", where D is a class derived (clause
5699 _class.derived_) from B, if a valid standard conversion from
5700 "pointer to D" to "pointer to B" exists (_conv.ptr_), cv2 is the
5701 same cv-qualification as, or greater cv-qualification than, cv1,
5702 and B is not a virtual base class of D. */
5703 /* We check this case before checking the validity of "TYPE t =
5704 EXPR;" below because for this case:
5705
5706 struct B {};
5707 struct D : public B { D(const B&); };
5708 extern B& b;
5709 void f() { static_cast<const D&>(b); }
5710
5711 we want to avoid constructing a new D. The standard is not
5712 completely clear about this issue, but our interpretation is
5713 consistent with other compilers. */
5714 if (TREE_CODE (type) == REFERENCE_TYPE
5715 && CLASS_TYPE_P (TREE_TYPE (type))
5716 && CLASS_TYPE_P (intype)
5717 && (TYPE_REF_IS_RVALUE (type) || real_lvalue_p (expr))
5718 && DERIVED_FROM_P (intype, TREE_TYPE (type))
5719 && can_convert (build_pointer_type (TYPE_MAIN_VARIANT (intype)),
5720 build_pointer_type (TYPE_MAIN_VARIANT
5721 (TREE_TYPE (type))))
5722 && (c_cast_p
5723 || at_least_as_qualified_p (TREE_TYPE (type), intype)))
5724 {
5725 tree base;
5726
5727 /* There is a standard conversion from "D*" to "B*" even if "B"
5728 is ambiguous or inaccessible. If this is really a
5729 static_cast, then we check both for inaccessibility and
5730 ambiguity. However, if this is a static_cast being performed
5731 because the user wrote a C-style cast, then accessibility is
5732 not considered. */
5733 base = lookup_base (TREE_TYPE (type), intype,
5734 c_cast_p ? ba_unique : ba_check,
5735 NULL);
5736
5737 /* Convert from "B*" to "D*". This function will check that "B"
5738 is not a virtual base of "D". */
5739 expr = build_base_path (MINUS_EXPR, build_address (expr),
5740 base, /*nonnull=*/false);
5741 /* Convert the pointer to a reference -- but then remember that
5742 there are no expressions with reference type in C++.
5743
5744 We call rvalue so that there's an actual tree code
5745 (NON_LVALUE_EXPR) for the static_cast; otherwise, if the operand
5746 is a variable with the same type, the conversion would get folded
5747 away, leaving just the variable and causing lvalue_kind to give
5748 the wrong answer. */
5749 return convert_from_reference (rvalue (cp_fold_convert (type, expr)));
5750 }
5751
5752 /* "An lvalue of type cv1 T1 can be cast to type rvalue reference to
5753 cv2 T2 if cv2 T2 is reference-compatible with cv1 T1 (8.5.3)." */
5754 if (TREE_CODE (type) == REFERENCE_TYPE
5755 && TYPE_REF_IS_RVALUE (type)
5756 && real_lvalue_p (expr)
5757 && reference_related_p (TREE_TYPE (type), intype)
5758 && (c_cast_p || at_least_as_qualified_p (TREE_TYPE (type), intype)))
5759 {
5760 expr = build_typed_address (expr, type);
5761 return convert_from_reference (expr);
5762 }
5763
5764 /* Resolve overloaded address here rather than once in
5765 implicit_conversion and again in the inverse code below. */
5766 if (TYPE_PTRMEMFUNC_P (type) && type_unknown_p (expr))
5767 {
5768 expr = instantiate_type (type, expr, complain);
5769 intype = TREE_TYPE (expr);
5770 }
5771
5772 /* [expr.static.cast]
5773
5774 An expression e can be explicitly converted to a type T using a
5775 static_cast of the form static_cast<T>(e) if the declaration T
5776 t(e);" is well-formed, for some invented temporary variable
5777 t. */
5778 result = perform_direct_initialization_if_possible (type, expr,
5779 c_cast_p, complain);
5780 if (result)
5781 {
5782 result = convert_from_reference (result);
5783
5784 /* [expr.static.cast]
5785
5786 If T is a reference type, the result is an lvalue; otherwise,
5787 the result is an rvalue. */
5788 if (TREE_CODE (type) != REFERENCE_TYPE)
5789 result = rvalue (result);
5790 return result;
5791 }
5792
5793 /* [expr.static.cast]
5794
5795 Any expression can be explicitly converted to type cv void. */
5796 if (TREE_CODE (type) == VOID_TYPE)
5797 return convert_to_void (expr, ICV_CAST, complain);
5798
5799 /* [expr.static.cast]
5800
5801 The inverse of any standard conversion sequence (clause _conv_),
5802 other than the lvalue-to-rvalue (_conv.lval_), array-to-pointer
5803 (_conv.array_), function-to-pointer (_conv.func_), and boolean
5804 (_conv.bool_) conversions, can be performed explicitly using
5805 static_cast subject to the restriction that the explicit
5806 conversion does not cast away constness (_expr.const.cast_), and
5807 the following additional rules for specific cases: */
5808 /* For reference, the conversions not excluded are: integral
5809 promotions, floating point promotion, integral conversions,
5810 floating point conversions, floating-integral conversions,
5811 pointer conversions, and pointer to member conversions. */
5812 /* DR 128
5813
5814 A value of integral _or enumeration_ type can be explicitly
5815 converted to an enumeration type. */
5816 /* The effect of all that is that any conversion between any two
5817 types which are integral, floating, or enumeration types can be
5818 performed. */
5819 if ((INTEGRAL_OR_ENUMERATION_TYPE_P (type)
5820 || SCALAR_FLOAT_TYPE_P (type))
5821 && (INTEGRAL_OR_ENUMERATION_TYPE_P (intype)
5822 || SCALAR_FLOAT_TYPE_P (intype)))
5823 return ocp_convert (type, expr, CONV_C_CAST, LOOKUP_NORMAL);
5824
5825 if (TYPE_PTR_P (type) && TYPE_PTR_P (intype)
5826 && CLASS_TYPE_P (TREE_TYPE (type))
5827 && CLASS_TYPE_P (TREE_TYPE (intype))
5828 && can_convert (build_pointer_type (TYPE_MAIN_VARIANT
5829 (TREE_TYPE (intype))),
5830 build_pointer_type (TYPE_MAIN_VARIANT
5831 (TREE_TYPE (type)))))
5832 {
5833 tree base;
5834
5835 if (!c_cast_p)
5836 check_for_casting_away_constness (intype, type, STATIC_CAST_EXPR);
5837 base = lookup_base (TREE_TYPE (type), TREE_TYPE (intype),
5838 c_cast_p ? ba_unique : ba_check,
5839 NULL);
5840 expr = build_base_path (MINUS_EXPR, expr, base, /*nonnull=*/false);
5841 return cp_fold_convert(type, expr);
5842 }
5843
5844 if ((TYPE_PTRMEM_P (type) && TYPE_PTRMEM_P (intype))
5845 || (TYPE_PTRMEMFUNC_P (type) && TYPE_PTRMEMFUNC_P (intype)))
5846 {
5847 tree c1;
5848 tree c2;
5849 tree t1;
5850 tree t2;
5851
5852 c1 = TYPE_PTRMEM_CLASS_TYPE (intype);
5853 c2 = TYPE_PTRMEM_CLASS_TYPE (type);
5854
5855 if (TYPE_PTRMEM_P (type))
5856 {
5857 t1 = (build_ptrmem_type
5858 (c1,
5859 TYPE_MAIN_VARIANT (TYPE_PTRMEM_POINTED_TO_TYPE (intype))));
5860 t2 = (build_ptrmem_type
5861 (c2,
5862 TYPE_MAIN_VARIANT (TYPE_PTRMEM_POINTED_TO_TYPE (type))));
5863 }
5864 else
5865 {
5866 t1 = intype;
5867 t2 = type;
5868 }
5869 if (can_convert (t1, t2) || can_convert (t2, t1))
5870 {
5871 if (!c_cast_p)
5872 check_for_casting_away_constness (intype, type, STATIC_CAST_EXPR);
5873 return convert_ptrmem (type, expr, /*allow_inverse_p=*/1,
5874 c_cast_p, tf_warning_or_error);
5875 }
5876 }
5877
5878 /* [expr.static.cast]
5879
5880 An rvalue of type "pointer to cv void" can be explicitly
5881 converted to a pointer to object type. A value of type pointer
5882 to object converted to "pointer to cv void" and back to the
5883 original pointer type will have its original value. */
5884 if (TREE_CODE (intype) == POINTER_TYPE
5885 && VOID_TYPE_P (TREE_TYPE (intype))
5886 && TYPE_PTROB_P (type))
5887 {
5888 if (!c_cast_p)
5889 check_for_casting_away_constness (intype, type, STATIC_CAST_EXPR);
5890 return build_nop (type, expr);
5891 }
5892
5893 *valid_p = false;
5894 return error_mark_node;
5895 }
5896
5897 /* Return an expression representing static_cast<TYPE>(EXPR). */
5898
5899 tree
5900 build_static_cast (tree type, tree expr, tsubst_flags_t complain)
5901 {
5902 tree result;
5903 bool valid_p;
5904
5905 if (type == error_mark_node || expr == error_mark_node)
5906 return error_mark_node;
5907
5908 if (processing_template_decl)
5909 {
5910 expr = build_min (STATIC_CAST_EXPR, type, expr);
5911 /* We don't know if it will or will not have side effects. */
5912 TREE_SIDE_EFFECTS (expr) = 1;
5913 return convert_from_reference (expr);
5914 }
5915
5916 /* build_c_cast puts on a NOP_EXPR to make the result not an lvalue.
5917 Strip such NOP_EXPRs if VALUE is being used in non-lvalue context. */
5918 if (TREE_CODE (type) != REFERENCE_TYPE
5919 && TREE_CODE (expr) == NOP_EXPR
5920 && TREE_TYPE (expr) == TREE_TYPE (TREE_OPERAND (expr, 0)))
5921 expr = TREE_OPERAND (expr, 0);
5922
5923 result = build_static_cast_1 (type, expr, /*c_cast_p=*/false, &valid_p,
5924 complain);
5925 if (valid_p)
5926 return result;
5927
5928 if (complain & tf_error)
5929 error ("invalid static_cast from type %qT to type %qT",
5930 TREE_TYPE (expr), type);
5931 return error_mark_node;
5932 }
5933
5934 /* EXPR is an expression with member function or pointer-to-member
5935 function type. TYPE is a pointer type. Converting EXPR to TYPE is
5936 not permitted by ISO C++, but we accept it in some modes. If we
5937 are not in one of those modes, issue a diagnostic. Return the
5938 converted expression. */
5939
5940 tree
5941 convert_member_func_to_ptr (tree type, tree expr)
5942 {
5943 tree intype;
5944 tree decl;
5945
5946 intype = TREE_TYPE (expr);
5947 gcc_assert (TYPE_PTRMEMFUNC_P (intype)
5948 || TREE_CODE (intype) == METHOD_TYPE);
5949
5950 if (pedantic || warn_pmf2ptr)
5951 pedwarn (input_location, pedantic ? OPT_pedantic : OPT_Wpmf_conversions,
5952 "converting from %qT to %qT", intype, type);
5953
5954 if (TREE_CODE (intype) == METHOD_TYPE)
5955 expr = build_addr_func (expr);
5956 else if (TREE_CODE (expr) == PTRMEM_CST)
5957 expr = build_address (PTRMEM_CST_MEMBER (expr));
5958 else
5959 {
5960 decl = maybe_dummy_object (TYPE_PTRMEM_CLASS_TYPE (intype), 0);
5961 decl = build_address (decl);
5962 expr = get_member_function_from_ptrfunc (&decl, expr);
5963 }
5964
5965 return build_nop (type, expr);
5966 }
5967
5968 /* Return a representation for a reinterpret_cast from EXPR to TYPE.
5969 If C_CAST_P is true, this reinterpret cast is being done as part of
5970 a C-style cast. If VALID_P is non-NULL, *VALID_P is set to
5971 indicate whether or not reinterpret_cast was valid. */
5972
5973 static tree
5974 build_reinterpret_cast_1 (tree type, tree expr, bool c_cast_p,
5975 bool *valid_p, tsubst_flags_t complain)
5976 {
5977 tree intype;
5978
5979 /* Assume the cast is invalid. */
5980 if (valid_p)
5981 *valid_p = true;
5982
5983 if (type == error_mark_node || error_operand_p (expr))
5984 return error_mark_node;
5985
5986 intype = TREE_TYPE (expr);
5987
5988 /* Save casted types in the function's used types hash table. */
5989 used_types_insert (type);
5990
5991 /* [expr.reinterpret.cast]
5992 An lvalue expression of type T1 can be cast to the type
5993 "reference to T2" if an expression of type "pointer to T1" can be
5994 explicitly converted to the type "pointer to T2" using a
5995 reinterpret_cast. */
5996 if (TREE_CODE (type) == REFERENCE_TYPE)
5997 {
5998 if (! real_lvalue_p (expr))
5999 {
6000 if (complain & tf_error)
6001 error ("invalid cast of an rvalue expression of type "
6002 "%qT to type %qT",
6003 intype, type);
6004 return error_mark_node;
6005 }
6006
6007 /* Warn about a reinterpret_cast from "A*" to "B&" if "A" and
6008 "B" are related class types; the reinterpret_cast does not
6009 adjust the pointer. */
6010 if (TYPE_PTR_P (intype)
6011 && (complain & tf_warning)
6012 && (comptypes (TREE_TYPE (intype), TREE_TYPE (type),
6013 COMPARE_BASE | COMPARE_DERIVED)))
6014 warning (0, "casting %qT to %qT does not dereference pointer",
6015 intype, type);
6016
6017 expr = cp_build_addr_expr (expr, complain);
6018
6019 if (warn_strict_aliasing > 2)
6020 strict_aliasing_warning (TREE_TYPE (expr), type, expr);
6021
6022 if (expr != error_mark_node)
6023 expr = build_reinterpret_cast_1
6024 (build_pointer_type (TREE_TYPE (type)), expr, c_cast_p,
6025 valid_p, complain);
6026 if (expr != error_mark_node)
6027 /* cp_build_indirect_ref isn't right for rvalue refs. */
6028 expr = convert_from_reference (fold_convert (type, expr));
6029 return expr;
6030 }
6031
6032 /* As a G++ extension, we consider conversions from member
6033 functions, and pointers to member functions to
6034 pointer-to-function and pointer-to-void types. If
6035 -Wno-pmf-conversions has not been specified,
6036 convert_member_func_to_ptr will issue an error message. */
6037 if ((TYPE_PTRMEMFUNC_P (intype)
6038 || TREE_CODE (intype) == METHOD_TYPE)
6039 && TYPE_PTR_P (type)
6040 && (TREE_CODE (TREE_TYPE (type)) == FUNCTION_TYPE
6041 || VOID_TYPE_P (TREE_TYPE (type))))
6042 return convert_member_func_to_ptr (type, expr);
6043
6044 /* If the cast is not to a reference type, the lvalue-to-rvalue,
6045 array-to-pointer, and function-to-pointer conversions are
6046 performed. */
6047 expr = decay_conversion (expr);
6048
6049 /* build_c_cast puts on a NOP_EXPR to make the result not an lvalue.
6050 Strip such NOP_EXPRs if VALUE is being used in non-lvalue context. */
6051 if (TREE_CODE (expr) == NOP_EXPR
6052 && TREE_TYPE (expr) == TREE_TYPE (TREE_OPERAND (expr, 0)))
6053 expr = TREE_OPERAND (expr, 0);
6054
6055 if (error_operand_p (expr))
6056 return error_mark_node;
6057
6058 intype = TREE_TYPE (expr);
6059
6060 /* [expr.reinterpret.cast]
6061 A pointer can be converted to any integral type large enough to
6062 hold it. ... A value of type std::nullptr_t can be converted to
6063 an integral type; the conversion has the same meaning and
6064 validity as a conversion of (void*)0 to the integral type. */
6065 if (CP_INTEGRAL_TYPE_P (type)
6066 && (TYPE_PTR_P (intype) || NULLPTR_TYPE_P (intype)))
6067 {
6068 if (TYPE_PRECISION (type) < TYPE_PRECISION (intype))
6069 {
6070 if (complain & tf_error)
6071 permerror (input_location, "cast from %qT to %qT loses precision",
6072 intype, type);
6073 else
6074 return error_mark_node;
6075 }
6076 if (NULLPTR_TYPE_P (intype))
6077 return build_int_cst (type, 0);
6078 }
6079 /* [expr.reinterpret.cast]
6080 A value of integral or enumeration type can be explicitly
6081 converted to a pointer. */
6082 else if (TYPE_PTR_P (type) && INTEGRAL_OR_ENUMERATION_TYPE_P (intype))
6083 /* OK */
6084 ;
6085 else if ((TYPE_PTRFN_P (type) && TYPE_PTRFN_P (intype))
6086 || (TYPE_PTRMEMFUNC_P (type) && TYPE_PTRMEMFUNC_P (intype)))
6087 return fold_if_not_in_template (build_nop (type, expr));
6088 else if ((TYPE_PTRMEM_P (type) && TYPE_PTRMEM_P (intype))
6089 || (TYPE_PTROBV_P (type) && TYPE_PTROBV_P (intype)))
6090 {
6091 tree sexpr = expr;
6092
6093 if (!c_cast_p)
6094 check_for_casting_away_constness (intype, type, REINTERPRET_CAST_EXPR);
6095 /* Warn about possible alignment problems. */
6096 if (STRICT_ALIGNMENT && warn_cast_align
6097 && (complain & tf_warning)
6098 && !VOID_TYPE_P (type)
6099 && TREE_CODE (TREE_TYPE (intype)) != FUNCTION_TYPE
6100 && COMPLETE_TYPE_P (TREE_TYPE (type))
6101 && COMPLETE_TYPE_P (TREE_TYPE (intype))
6102 && TYPE_ALIGN (TREE_TYPE (type)) > TYPE_ALIGN (TREE_TYPE (intype)))
6103 warning (OPT_Wcast_align, "cast from %qT to %qT "
6104 "increases required alignment of target type", intype, type);
6105
6106 /* We need to strip nops here, because the front end likes to
6107 create (int *)&a for array-to-pointer decay, instead of &a[0]. */
6108 STRIP_NOPS (sexpr);
6109 if (warn_strict_aliasing <= 2)
6110 strict_aliasing_warning (intype, type, sexpr);
6111
6112 return fold_if_not_in_template (build_nop (type, expr));
6113 }
6114 else if ((TYPE_PTRFN_P (type) && TYPE_PTROBV_P (intype))
6115 || (TYPE_PTRFN_P (intype) && TYPE_PTROBV_P (type)))
6116 {
6117 if (pedantic && (complain & tf_warning))
6118 /* Only issue a warning, as we have always supported this
6119 where possible, and it is necessary in some cases. DR 195
6120 addresses this issue, but as of 2004/10/26 is still in
6121 drafting. */
6122 warning (0, "ISO C++ forbids casting between pointer-to-function and pointer-to-object");
6123 return fold_if_not_in_template (build_nop (type, expr));
6124 }
6125 else if (TREE_CODE (type) == VECTOR_TYPE)
6126 return fold_if_not_in_template (convert_to_vector (type, expr));
6127 else if (TREE_CODE (intype) == VECTOR_TYPE
6128 && INTEGRAL_OR_ENUMERATION_TYPE_P (type))
6129 return fold_if_not_in_template (convert_to_integer (type, expr));
6130 else
6131 {
6132 if (valid_p)
6133 *valid_p = false;
6134 if (complain & tf_error)
6135 error ("invalid cast from type %qT to type %qT", intype, type);
6136 return error_mark_node;
6137 }
6138
6139 return cp_convert (type, expr);
6140 }
6141
6142 tree
6143 build_reinterpret_cast (tree type, tree expr, tsubst_flags_t complain)
6144 {
6145 if (type == error_mark_node || expr == error_mark_node)
6146 return error_mark_node;
6147
6148 if (processing_template_decl)
6149 {
6150 tree t = build_min (REINTERPRET_CAST_EXPR, type, expr);
6151
6152 if (!TREE_SIDE_EFFECTS (t)
6153 && type_dependent_expression_p (expr))
6154 /* There might turn out to be side effects inside expr. */
6155 TREE_SIDE_EFFECTS (t) = 1;
6156 return convert_from_reference (t);
6157 }
6158
6159 return build_reinterpret_cast_1 (type, expr, /*c_cast_p=*/false,
6160 /*valid_p=*/NULL, complain);
6161 }
6162
6163 /* Perform a const_cast from EXPR to TYPE. If the cast is valid,
6164 return an appropriate expression. Otherwise, return
6165 error_mark_node. If the cast is not valid, and COMPLAIN is true,
6166 then a diagnostic will be issued. If VALID_P is non-NULL, we are
6167 performing a C-style cast, its value upon return will indicate
6168 whether or not the conversion succeeded. */
6169
6170 static tree
6171 build_const_cast_1 (tree dst_type, tree expr, bool complain,
6172 bool *valid_p)
6173 {
6174 tree src_type;
6175 tree reference_type;
6176
6177 /* Callers are responsible for handling error_mark_node as a
6178 destination type. */
6179 gcc_assert (dst_type != error_mark_node);
6180 /* In a template, callers should be building syntactic
6181 representations of casts, not using this machinery. */
6182 gcc_assert (!processing_template_decl);
6183
6184 /* Assume the conversion is invalid. */
6185 if (valid_p)
6186 *valid_p = false;
6187
6188 if (!POINTER_TYPE_P (dst_type) && !TYPE_PTRMEM_P (dst_type))
6189 {
6190 if (complain)
6191 error ("invalid use of const_cast with type %qT, "
6192 "which is not a pointer, "
6193 "reference, nor a pointer-to-data-member type", dst_type);
6194 return error_mark_node;
6195 }
6196
6197 if (TREE_CODE (TREE_TYPE (dst_type)) == FUNCTION_TYPE)
6198 {
6199 if (complain)
6200 error ("invalid use of const_cast with type %qT, which is a pointer "
6201 "or reference to a function type", dst_type);
6202 return error_mark_node;
6203 }
6204
6205 /* Save casted types in the function's used types hash table. */
6206 used_types_insert (dst_type);
6207
6208 src_type = TREE_TYPE (expr);
6209 /* Expressions do not really have reference types. */
6210 if (TREE_CODE (src_type) == REFERENCE_TYPE)
6211 src_type = TREE_TYPE (src_type);
6212
6213 /* [expr.const.cast]
6214
6215 An lvalue of type T1 can be explicitly converted to an lvalue of
6216 type T2 using the cast const_cast<T2&> (where T1 and T2 are object
6217 types) if a pointer to T1 can be explicitly converted to the type
6218 pointer to T2 using a const_cast. */
6219 if (TREE_CODE (dst_type) == REFERENCE_TYPE)
6220 {
6221 reference_type = dst_type;
6222 if (! real_lvalue_p (expr))
6223 {
6224 if (complain)
6225 error ("invalid const_cast of an rvalue of type %qT to type %qT",
6226 src_type, dst_type);
6227 return error_mark_node;
6228 }
6229 dst_type = build_pointer_type (TREE_TYPE (dst_type));
6230 src_type = build_pointer_type (src_type);
6231 }
6232 else
6233 {
6234 reference_type = NULL_TREE;
6235 /* If the destination type is not a reference type, the
6236 lvalue-to-rvalue, array-to-pointer, and function-to-pointer
6237 conversions are performed. */
6238 src_type = type_decays_to (src_type);
6239 if (src_type == error_mark_node)
6240 return error_mark_node;
6241 }
6242
6243 if ((TYPE_PTR_P (src_type) || TYPE_PTRMEM_P (src_type))
6244 && comp_ptr_ttypes_const (dst_type, src_type))
6245 {
6246 if (valid_p)
6247 {
6248 *valid_p = true;
6249 /* This cast is actually a C-style cast. Issue a warning if
6250 the user is making a potentially unsafe cast. */
6251 check_for_casting_away_constness (src_type, dst_type, CAST_EXPR);
6252 }
6253 if (reference_type)
6254 {
6255 expr = cp_build_addr_expr (expr,
6256 complain ? tf_warning_or_error : tf_none);
6257 expr = build_nop (reference_type, expr);
6258 return convert_from_reference (expr);
6259 }
6260 else
6261 {
6262 expr = decay_conversion (expr);
6263 /* build_c_cast puts on a NOP_EXPR to make the result not an
6264 lvalue. Strip such NOP_EXPRs if VALUE is being used in
6265 non-lvalue context. */
6266 if (TREE_CODE (expr) == NOP_EXPR
6267 && TREE_TYPE (expr) == TREE_TYPE (TREE_OPERAND (expr, 0)))
6268 expr = TREE_OPERAND (expr, 0);
6269 return build_nop (dst_type, expr);
6270 }
6271 }
6272
6273 if (complain)
6274 error ("invalid const_cast from type %qT to type %qT",
6275 src_type, dst_type);
6276 return error_mark_node;
6277 }
6278
6279 tree
6280 build_const_cast (tree type, tree expr, tsubst_flags_t complain)
6281 {
6282 if (type == error_mark_node || error_operand_p (expr))
6283 return error_mark_node;
6284
6285 if (processing_template_decl)
6286 {
6287 tree t = build_min (CONST_CAST_EXPR, type, expr);
6288
6289 if (!TREE_SIDE_EFFECTS (t)
6290 && type_dependent_expression_p (expr))
6291 /* There might turn out to be side effects inside expr. */
6292 TREE_SIDE_EFFECTS (t) = 1;
6293 return convert_from_reference (t);
6294 }
6295
6296 return build_const_cast_1 (type, expr, complain & tf_error,
6297 /*valid_p=*/NULL);
6298 }
6299
6300 /* Like cp_build_c_cast, but for the c-common bits. */
6301
6302 tree
6303 build_c_cast (location_t loc ATTRIBUTE_UNUSED, tree type, tree expr)
6304 {
6305 return cp_build_c_cast (type, expr, tf_warning_or_error);
6306 }
6307
6308 /* Build an expression representing an explicit C-style cast to type
6309 TYPE of expression EXPR. */
6310
6311 tree
6312 cp_build_c_cast (tree type, tree expr, tsubst_flags_t complain)
6313 {
6314 tree value = expr;
6315 tree result;
6316 bool valid_p;
6317
6318 if (type == error_mark_node || error_operand_p (expr))
6319 return error_mark_node;
6320
6321 if (processing_template_decl)
6322 {
6323 tree t = build_min (CAST_EXPR, type,
6324 tree_cons (NULL_TREE, value, NULL_TREE));
6325 /* We don't know if it will or will not have side effects. */
6326 TREE_SIDE_EFFECTS (t) = 1;
6327 return convert_from_reference (t);
6328 }
6329
6330 /* Casts to a (pointer to a) specific ObjC class (or 'id' or
6331 'Class') should always be retained, because this information aids
6332 in method lookup. */
6333 if (objc_is_object_ptr (type)
6334 && objc_is_object_ptr (TREE_TYPE (expr)))
6335 return build_nop (type, expr);
6336
6337 /* build_c_cast puts on a NOP_EXPR to make the result not an lvalue.
6338 Strip such NOP_EXPRs if VALUE is being used in non-lvalue context. */
6339 if (TREE_CODE (type) != REFERENCE_TYPE
6340 && TREE_CODE (value) == NOP_EXPR
6341 && TREE_TYPE (value) == TREE_TYPE (TREE_OPERAND (value, 0)))
6342 value = TREE_OPERAND (value, 0);
6343
6344 if (TREE_CODE (type) == ARRAY_TYPE)
6345 {
6346 /* Allow casting from T1* to T2[] because Cfront allows it.
6347 NIHCL uses it. It is not valid ISO C++ however. */
6348 if (TREE_CODE (TREE_TYPE (expr)) == POINTER_TYPE)
6349 {
6350 if (complain & tf_error)
6351 permerror (input_location, "ISO C++ forbids casting to an array type %qT", type);
6352 else
6353 return error_mark_node;
6354 type = build_pointer_type (TREE_TYPE (type));
6355 }
6356 else
6357 {
6358 if (complain & tf_error)
6359 error ("ISO C++ forbids casting to an array type %qT", type);
6360 return error_mark_node;
6361 }
6362 }
6363
6364 if (TREE_CODE (type) == FUNCTION_TYPE
6365 || TREE_CODE (type) == METHOD_TYPE)
6366 {
6367 if (complain & tf_error)
6368 error ("invalid cast to function type %qT", type);
6369 return error_mark_node;
6370 }
6371
6372 if (TREE_CODE (type) == POINTER_TYPE
6373 && TREE_CODE (TREE_TYPE (value)) == INTEGER_TYPE
6374 /* Casting to an integer of smaller size is an error detected elsewhere. */
6375 && TYPE_PRECISION (type) > TYPE_PRECISION (TREE_TYPE (value))
6376 /* Don't warn about converting any constant. */
6377 && !TREE_CONSTANT (value))
6378 warning_at (input_location, OPT_Wint_to_pointer_cast,
6379 "cast to pointer from integer of different size");
6380
6381 /* A C-style cast can be a const_cast. */
6382 result = build_const_cast_1 (type, value, /*complain=*/false,
6383 &valid_p);
6384 if (valid_p)
6385 return result;
6386
6387 /* Or a static cast. */
6388 result = build_static_cast_1 (type, value, /*c_cast_p=*/true,
6389 &valid_p, complain);
6390 /* Or a reinterpret_cast. */
6391 if (!valid_p)
6392 result = build_reinterpret_cast_1 (type, value, /*c_cast_p=*/true,
6393 &valid_p, complain);
6394 /* The static_cast or reinterpret_cast may be followed by a
6395 const_cast. */
6396 if (valid_p
6397 /* A valid cast may result in errors if, for example, a
6398 conversion to am ambiguous base class is required. */
6399 && !error_operand_p (result))
6400 {
6401 tree result_type;
6402
6403 /* Non-class rvalues always have cv-unqualified type. */
6404 if (!CLASS_TYPE_P (type))
6405 type = TYPE_MAIN_VARIANT (type);
6406 result_type = TREE_TYPE (result);
6407 if (!CLASS_TYPE_P (result_type))
6408 result_type = TYPE_MAIN_VARIANT (result_type);
6409 /* If the type of RESULT does not match TYPE, perform a
6410 const_cast to make it match. If the static_cast or
6411 reinterpret_cast succeeded, we will differ by at most
6412 cv-qualification, so the follow-on const_cast is guaranteed
6413 to succeed. */
6414 if (!same_type_p (non_reference (type), non_reference (result_type)))
6415 {
6416 result = build_const_cast_1 (type, result, false, &valid_p);
6417 gcc_assert (valid_p);
6418 }
6419 return result;
6420 }
6421
6422 return error_mark_node;
6423 }
6424 \f
6425 /* For use from the C common bits. */
6426 tree
6427 build_modify_expr (location_t location ATTRIBUTE_UNUSED,
6428 tree lhs, tree lhs_origtype ATTRIBUTE_UNUSED,
6429 enum tree_code modifycode,
6430 location_t rhs_location ATTRIBUTE_UNUSED, tree rhs,
6431 tree rhs_origtype ATTRIBUTE_UNUSED)
6432 {
6433 return cp_build_modify_expr (lhs, modifycode, rhs, tf_warning_or_error);
6434 }
6435
6436 /* Build an assignment expression of lvalue LHS from value RHS.
6437 MODIFYCODE is the code for a binary operator that we use
6438 to combine the old value of LHS with RHS to get the new value.
6439 Or else MODIFYCODE is NOP_EXPR meaning do a simple assignment.
6440
6441 C++: If MODIFYCODE is INIT_EXPR, then leave references unbashed. */
6442
6443 tree
6444 cp_build_modify_expr (tree lhs, enum tree_code modifycode, tree rhs,
6445 tsubst_flags_t complain)
6446 {
6447 tree result;
6448 tree newrhs = rhs;
6449 tree lhstype = TREE_TYPE (lhs);
6450 tree olhstype = lhstype;
6451 bool plain_assign = (modifycode == NOP_EXPR);
6452
6453 /* Avoid duplicate error messages from operands that had errors. */
6454 if (error_operand_p (lhs) || error_operand_p (rhs))
6455 return error_mark_node;
6456
6457 /* Handle control structure constructs used as "lvalues". */
6458 switch (TREE_CODE (lhs))
6459 {
6460 /* Handle --foo = 5; as these are valid constructs in C++. */
6461 case PREDECREMENT_EXPR:
6462 case PREINCREMENT_EXPR:
6463 if (TREE_SIDE_EFFECTS (TREE_OPERAND (lhs, 0)))
6464 lhs = build2 (TREE_CODE (lhs), TREE_TYPE (lhs),
6465 stabilize_reference (TREE_OPERAND (lhs, 0)),
6466 TREE_OPERAND (lhs, 1));
6467 newrhs = cp_build_modify_expr (TREE_OPERAND (lhs, 0),
6468 modifycode, rhs, complain);
6469 if (newrhs == error_mark_node)
6470 return error_mark_node;
6471 return build2 (COMPOUND_EXPR, lhstype, lhs, newrhs);
6472
6473 /* Handle (a, b) used as an "lvalue". */
6474 case COMPOUND_EXPR:
6475 newrhs = cp_build_modify_expr (TREE_OPERAND (lhs, 1),
6476 modifycode, rhs, complain);
6477 if (newrhs == error_mark_node)
6478 return error_mark_node;
6479 return build2 (COMPOUND_EXPR, lhstype,
6480 TREE_OPERAND (lhs, 0), newrhs);
6481
6482 case MODIFY_EXPR:
6483 if (TREE_SIDE_EFFECTS (TREE_OPERAND (lhs, 0)))
6484 lhs = build2 (TREE_CODE (lhs), TREE_TYPE (lhs),
6485 stabilize_reference (TREE_OPERAND (lhs, 0)),
6486 TREE_OPERAND (lhs, 1));
6487 newrhs = cp_build_modify_expr (TREE_OPERAND (lhs, 0), modifycode, rhs,
6488 complain);
6489 if (newrhs == error_mark_node)
6490 return error_mark_node;
6491 return build2 (COMPOUND_EXPR, lhstype, lhs, newrhs);
6492
6493 case MIN_EXPR:
6494 case MAX_EXPR:
6495 /* MIN_EXPR and MAX_EXPR are currently only permitted as lvalues,
6496 when neither operand has side-effects. */
6497 if (!lvalue_or_else (lhs, lv_assign, complain))
6498 return error_mark_node;
6499
6500 gcc_assert (!TREE_SIDE_EFFECTS (TREE_OPERAND (lhs, 0))
6501 && !TREE_SIDE_EFFECTS (TREE_OPERAND (lhs, 1)));
6502
6503 lhs = build3 (COND_EXPR, TREE_TYPE (lhs),
6504 build2 (TREE_CODE (lhs) == MIN_EXPR ? LE_EXPR : GE_EXPR,
6505 boolean_type_node,
6506 TREE_OPERAND (lhs, 0),
6507 TREE_OPERAND (lhs, 1)),
6508 TREE_OPERAND (lhs, 0),
6509 TREE_OPERAND (lhs, 1));
6510 /* Fall through. */
6511
6512 /* Handle (a ? b : c) used as an "lvalue". */
6513 case COND_EXPR:
6514 {
6515 /* Produce (a ? (b = rhs) : (c = rhs))
6516 except that the RHS goes through a save-expr
6517 so the code to compute it is only emitted once. */
6518 tree cond;
6519 tree preeval = NULL_TREE;
6520
6521 if (VOID_TYPE_P (TREE_TYPE (rhs)))
6522 {
6523 if (complain & tf_error)
6524 error ("void value not ignored as it ought to be");
6525 return error_mark_node;
6526 }
6527
6528 rhs = stabilize_expr (rhs, &preeval);
6529
6530 /* Check this here to avoid odd errors when trying to convert
6531 a throw to the type of the COND_EXPR. */
6532 if (!lvalue_or_else (lhs, lv_assign, complain))
6533 return error_mark_node;
6534
6535 cond = build_conditional_expr
6536 (TREE_OPERAND (lhs, 0),
6537 cp_build_modify_expr (TREE_OPERAND (lhs, 1),
6538 modifycode, rhs, complain),
6539 cp_build_modify_expr (TREE_OPERAND (lhs, 2),
6540 modifycode, rhs, complain),
6541 complain);
6542
6543 if (cond == error_mark_node)
6544 return cond;
6545 /* Make sure the code to compute the rhs comes out
6546 before the split. */
6547 if (preeval)
6548 cond = build2 (COMPOUND_EXPR, TREE_TYPE (lhs), preeval, cond);
6549 return cond;
6550 }
6551
6552 default:
6553 break;
6554 }
6555
6556 if (modifycode == INIT_EXPR)
6557 {
6558 if (BRACE_ENCLOSED_INITIALIZER_P (rhs))
6559 /* Do the default thing. */;
6560 else if (TREE_CODE (rhs) == CONSTRUCTOR)
6561 {
6562 /* Compound literal. */
6563 if (! same_type_p (TREE_TYPE (rhs), lhstype))
6564 /* Call convert to generate an error; see PR 11063. */
6565 rhs = convert (lhstype, rhs);
6566 result = build2 (INIT_EXPR, lhstype, lhs, rhs);
6567 TREE_SIDE_EFFECTS (result) = 1;
6568 return result;
6569 }
6570 else if (! MAYBE_CLASS_TYPE_P (lhstype))
6571 /* Do the default thing. */;
6572 else
6573 {
6574 VEC(tree,gc) *rhs_vec = make_tree_vector_single (rhs);
6575 result = build_special_member_call (lhs, complete_ctor_identifier,
6576 &rhs_vec, lhstype, LOOKUP_NORMAL,
6577 complain);
6578 release_tree_vector (rhs_vec);
6579 if (result == NULL_TREE)
6580 return error_mark_node;
6581 return result;
6582 }
6583 }
6584 else
6585 {
6586 lhs = require_complete_type_sfinae (lhs, complain);
6587 if (lhs == error_mark_node)
6588 return error_mark_node;
6589
6590 if (modifycode == NOP_EXPR)
6591 {
6592 if (c_dialect_objc ())
6593 {
6594 result = objc_maybe_build_modify_expr (lhs, rhs);
6595 if (result)
6596 return result;
6597 }
6598
6599 /* `operator=' is not an inheritable operator. */
6600 if (! MAYBE_CLASS_TYPE_P (lhstype))
6601 /* Do the default thing. */;
6602 else
6603 {
6604 result = build_new_op (MODIFY_EXPR, LOOKUP_NORMAL,
6605 lhs, rhs, make_node (NOP_EXPR),
6606 /*overloaded_p=*/NULL,
6607 complain);
6608 if (result == NULL_TREE)
6609 return error_mark_node;
6610 return result;
6611 }
6612 lhstype = olhstype;
6613 }
6614 else
6615 {
6616 /* A binary op has been requested. Combine the old LHS
6617 value with the RHS producing the value we should actually
6618 store into the LHS. */
6619 gcc_assert (!((TREE_CODE (lhstype) == REFERENCE_TYPE
6620 && MAYBE_CLASS_TYPE_P (TREE_TYPE (lhstype)))
6621 || MAYBE_CLASS_TYPE_P (lhstype)));
6622
6623 lhs = stabilize_reference (lhs);
6624 newrhs = cp_build_binary_op (input_location,
6625 modifycode, lhs, rhs,
6626 complain);
6627 if (newrhs == error_mark_node)
6628 {
6629 if (complain & tf_error)
6630 error (" in evaluation of %<%Q(%#T, %#T)%>", modifycode,
6631 TREE_TYPE (lhs), TREE_TYPE (rhs));
6632 return error_mark_node;
6633 }
6634
6635 /* Now it looks like a plain assignment. */
6636 modifycode = NOP_EXPR;
6637 if (c_dialect_objc ())
6638 {
6639 result = objc_maybe_build_modify_expr (lhs, newrhs);
6640 if (result)
6641 return result;
6642 }
6643 }
6644 gcc_assert (TREE_CODE (lhstype) != REFERENCE_TYPE);
6645 gcc_assert (TREE_CODE (TREE_TYPE (newrhs)) != REFERENCE_TYPE);
6646 }
6647
6648 /* The left-hand side must be an lvalue. */
6649 if (!lvalue_or_else (lhs, lv_assign, complain))
6650 return error_mark_node;
6651
6652 /* Warn about modifying something that is `const'. Don't warn if
6653 this is initialization. */
6654 if (modifycode != INIT_EXPR
6655 && (TREE_READONLY (lhs) || CP_TYPE_CONST_P (lhstype)
6656 /* Functions are not modifiable, even though they are
6657 lvalues. */
6658 || TREE_CODE (TREE_TYPE (lhs)) == FUNCTION_TYPE
6659 || TREE_CODE (TREE_TYPE (lhs)) == METHOD_TYPE
6660 /* If it's an aggregate and any field is const, then it is
6661 effectively const. */
6662 || (CLASS_TYPE_P (lhstype)
6663 && C_TYPE_FIELDS_READONLY (lhstype))))
6664 {
6665 if (complain & tf_error)
6666 cxx_readonly_error (lhs, lv_assign);
6667 else
6668 return error_mark_node;
6669 }
6670
6671 /* If storing into a structure or union member, it may have been given a
6672 lowered bitfield type. We need to convert to the declared type first,
6673 so retrieve it now. */
6674
6675 olhstype = unlowered_expr_type (lhs);
6676
6677 /* Convert new value to destination type. */
6678
6679 if (TREE_CODE (lhstype) == ARRAY_TYPE)
6680 {
6681 int from_array;
6682
6683 if (BRACE_ENCLOSED_INITIALIZER_P (newrhs))
6684 {
6685 if (modifycode != INIT_EXPR)
6686 {
6687 if (complain & tf_error)
6688 error ("assigning to an array from an initializer list");
6689 return error_mark_node;
6690 }
6691 if (check_array_initializer (lhs, lhstype, newrhs))
6692 return error_mark_node;
6693 newrhs = digest_init (lhstype, newrhs);
6694 }
6695
6696 else if (!same_or_base_type_p (TYPE_MAIN_VARIANT (lhstype),
6697 TYPE_MAIN_VARIANT (TREE_TYPE (newrhs))))
6698 {
6699 if (complain & tf_error)
6700 error ("incompatible types in assignment of %qT to %qT",
6701 TREE_TYPE (rhs), lhstype);
6702 return error_mark_node;
6703 }
6704
6705 /* Allow array assignment in compiler-generated code. */
6706 else if (!current_function_decl
6707 || !DECL_ARTIFICIAL (current_function_decl))
6708 {
6709 /* This routine is used for both initialization and assignment.
6710 Make sure the diagnostic message differentiates the context. */
6711 if (complain & tf_error)
6712 {
6713 if (modifycode == INIT_EXPR)
6714 error ("array used as initializer");
6715 else
6716 error ("invalid array assignment");
6717 }
6718 return error_mark_node;
6719 }
6720
6721 from_array = TREE_CODE (TREE_TYPE (newrhs)) == ARRAY_TYPE
6722 ? 1 + (modifycode != INIT_EXPR): 0;
6723 return build_vec_init (lhs, NULL_TREE, newrhs,
6724 /*explicit_value_init_p=*/false,
6725 from_array, complain);
6726 }
6727
6728 if (modifycode == INIT_EXPR)
6729 /* Calls with INIT_EXPR are all direct-initialization, so don't set
6730 LOOKUP_ONLYCONVERTING. */
6731 newrhs = convert_for_initialization (lhs, olhstype, newrhs, LOOKUP_NORMAL,
6732 ICR_INIT, NULL_TREE, 0,
6733 complain);
6734 else
6735 newrhs = convert_for_assignment (olhstype, newrhs, ICR_ASSIGN,
6736 NULL_TREE, 0, complain, LOOKUP_IMPLICIT);
6737
6738 if (!same_type_p (lhstype, olhstype))
6739 newrhs = cp_convert_and_check (lhstype, newrhs);
6740
6741 if (modifycode != INIT_EXPR)
6742 {
6743 if (TREE_CODE (newrhs) == CALL_EXPR
6744 && TYPE_NEEDS_CONSTRUCTING (lhstype))
6745 newrhs = build_cplus_new (lhstype, newrhs, complain);
6746
6747 /* Can't initialize directly from a TARGET_EXPR, since that would
6748 cause the lhs to be constructed twice, and possibly result in
6749 accidental self-initialization. So we force the TARGET_EXPR to be
6750 expanded without a target. */
6751 if (TREE_CODE (newrhs) == TARGET_EXPR)
6752 newrhs = build2 (COMPOUND_EXPR, TREE_TYPE (newrhs), newrhs,
6753 TREE_OPERAND (newrhs, 0));
6754 }
6755
6756 if (newrhs == error_mark_node)
6757 return error_mark_node;
6758
6759 if (c_dialect_objc () && flag_objc_gc)
6760 {
6761 result = objc_generate_write_barrier (lhs, modifycode, newrhs);
6762
6763 if (result)
6764 return result;
6765 }
6766
6767 result = build2 (modifycode == NOP_EXPR ? MODIFY_EXPR : INIT_EXPR,
6768 lhstype, lhs, newrhs);
6769
6770 TREE_SIDE_EFFECTS (result) = 1;
6771 if (!plain_assign)
6772 TREE_NO_WARNING (result) = 1;
6773
6774 return result;
6775 }
6776
6777 tree
6778 build_x_modify_expr (tree lhs, enum tree_code modifycode, tree rhs,
6779 tsubst_flags_t complain)
6780 {
6781 if (processing_template_decl)
6782 return build_min_nt (MODOP_EXPR, lhs,
6783 build_min_nt (modifycode, NULL_TREE, NULL_TREE), rhs);
6784
6785 if (modifycode != NOP_EXPR)
6786 {
6787 tree rval = build_new_op (MODIFY_EXPR, LOOKUP_NORMAL, lhs, rhs,
6788 make_node (modifycode),
6789 /*overloaded_p=*/NULL,
6790 complain);
6791 if (rval)
6792 {
6793 TREE_NO_WARNING (rval) = 1;
6794 return rval;
6795 }
6796 }
6797 return cp_build_modify_expr (lhs, modifycode, rhs, complain);
6798 }
6799
6800 /* Helper function for get_delta_difference which assumes FROM is a base
6801 class of TO. Returns a delta for the conversion of pointer-to-member
6802 of FROM to pointer-to-member of TO. If the conversion is invalid and
6803 tf_error is not set in COMPLAIN returns error_mark_node, otherwise
6804 returns zero. If FROM is not a base class of TO, returns NULL_TREE.
6805 If C_CAST_P is true, this conversion is taking place as part of a
6806 C-style cast. */
6807
6808 static tree
6809 get_delta_difference_1 (tree from, tree to, bool c_cast_p,
6810 tsubst_flags_t complain)
6811 {
6812 tree binfo;
6813 base_kind kind;
6814 base_access access = c_cast_p ? ba_unique : ba_check;
6815
6816 /* Note: ba_quiet does not distinguish between access control and
6817 ambiguity. */
6818 if (!(complain & tf_error))
6819 access |= ba_quiet;
6820
6821 binfo = lookup_base (to, from, access, &kind);
6822
6823 if (kind == bk_inaccessible || kind == bk_ambig)
6824 {
6825 if (!(complain & tf_error))
6826 return error_mark_node;
6827
6828 error (" in pointer to member function conversion");
6829 return size_zero_node;
6830 }
6831 else if (binfo)
6832 {
6833 if (kind != bk_via_virtual)
6834 return BINFO_OFFSET (binfo);
6835 else
6836 /* FROM is a virtual base class of TO. Issue an error or warning
6837 depending on whether or not this is a reinterpret cast. */
6838 {
6839 if (!(complain & tf_error))
6840 return error_mark_node;
6841
6842 error ("pointer to member conversion via virtual base %qT",
6843 BINFO_TYPE (binfo_from_vbase (binfo)));
6844
6845 return size_zero_node;
6846 }
6847 }
6848 else
6849 return NULL_TREE;
6850 }
6851
6852 /* Get difference in deltas for different pointer to member function
6853 types. If the conversion is invalid and tf_error is not set in
6854 COMPLAIN, returns error_mark_node, otherwise returns an integer
6855 constant of type PTRDIFF_TYPE_NODE and its value is zero if the
6856 conversion is invalid. If ALLOW_INVERSE_P is true, then allow reverse
6857 conversions as well. If C_CAST_P is true this conversion is taking
6858 place as part of a C-style cast.
6859
6860 Note that the naming of FROM and TO is kind of backwards; the return
6861 value is what we add to a TO in order to get a FROM. They are named
6862 this way because we call this function to find out how to convert from
6863 a pointer to member of FROM to a pointer to member of TO. */
6864
6865 static tree
6866 get_delta_difference (tree from, tree to,
6867 bool allow_inverse_p,
6868 bool c_cast_p, tsubst_flags_t complain)
6869 {
6870 tree result;
6871
6872 if (same_type_ignoring_top_level_qualifiers_p (from, to))
6873 /* Pointer to member of incomplete class is permitted*/
6874 result = size_zero_node;
6875 else
6876 result = get_delta_difference_1 (from, to, c_cast_p, complain);
6877
6878 if (result == error_mark_node)
6879 return error_mark_node;
6880
6881 if (!result)
6882 {
6883 if (!allow_inverse_p)
6884 {
6885 if (!(complain & tf_error))
6886 return error_mark_node;
6887
6888 error_not_base_type (from, to);
6889 error (" in pointer to member conversion");
6890 result = size_zero_node;
6891 }
6892 else
6893 {
6894 result = get_delta_difference_1 (to, from, c_cast_p, complain);
6895
6896 if (result == error_mark_node)
6897 return error_mark_node;
6898
6899 if (result)
6900 result = size_diffop_loc (input_location,
6901 size_zero_node, result);
6902 else
6903 {
6904 if (!(complain & tf_error))
6905 return error_mark_node;
6906
6907 error_not_base_type (from, to);
6908 error (" in pointer to member conversion");
6909 result = size_zero_node;
6910 }
6911 }
6912 }
6913
6914 return fold_if_not_in_template (convert_to_integer (ptrdiff_type_node,
6915 result));
6916 }
6917
6918 /* Return a constructor for the pointer-to-member-function TYPE using
6919 the other components as specified. */
6920
6921 tree
6922 build_ptrmemfunc1 (tree type, tree delta, tree pfn)
6923 {
6924 tree u = NULL_TREE;
6925 tree delta_field;
6926 tree pfn_field;
6927 VEC(constructor_elt, gc) *v;
6928
6929 /* Pull the FIELD_DECLs out of the type. */
6930 pfn_field = TYPE_FIELDS (type);
6931 delta_field = DECL_CHAIN (pfn_field);
6932
6933 /* Make sure DELTA has the type we want. */
6934 delta = convert_and_check (delta_type_node, delta);
6935
6936 /* Convert to the correct target type if necessary. */
6937 pfn = fold_convert (TREE_TYPE (pfn_field), pfn);
6938
6939 /* Finish creating the initializer. */
6940 v = VEC_alloc(constructor_elt, gc, 2);
6941 CONSTRUCTOR_APPEND_ELT(v, pfn_field, pfn);
6942 CONSTRUCTOR_APPEND_ELT(v, delta_field, delta);
6943 u = build_constructor (type, v);
6944 TREE_CONSTANT (u) = TREE_CONSTANT (pfn) & TREE_CONSTANT (delta);
6945 TREE_STATIC (u) = (TREE_CONSTANT (u)
6946 && (initializer_constant_valid_p (pfn, TREE_TYPE (pfn))
6947 != NULL_TREE)
6948 && (initializer_constant_valid_p (delta, TREE_TYPE (delta))
6949 != NULL_TREE));
6950 return u;
6951 }
6952
6953 /* Build a constructor for a pointer to member function. It can be
6954 used to initialize global variables, local variable, or used
6955 as a value in expressions. TYPE is the POINTER to METHOD_TYPE we
6956 want to be.
6957
6958 If FORCE is nonzero, then force this conversion, even if
6959 we would rather not do it. Usually set when using an explicit
6960 cast. A C-style cast is being processed iff C_CAST_P is true.
6961
6962 Return error_mark_node, if something goes wrong. */
6963
6964 tree
6965 build_ptrmemfunc (tree type, tree pfn, int force, bool c_cast_p,
6966 tsubst_flags_t complain)
6967 {
6968 tree fn;
6969 tree pfn_type;
6970 tree to_type;
6971
6972 if (error_operand_p (pfn))
6973 return error_mark_node;
6974
6975 pfn_type = TREE_TYPE (pfn);
6976 to_type = build_ptrmemfunc_type (type);
6977
6978 /* Handle multiple conversions of pointer to member functions. */
6979 if (TYPE_PTRMEMFUNC_P (pfn_type))
6980 {
6981 tree delta = NULL_TREE;
6982 tree npfn = NULL_TREE;
6983 tree n;
6984
6985 if (!force
6986 && !can_convert_arg (to_type, TREE_TYPE (pfn), pfn, LOOKUP_NORMAL))
6987 error ("invalid conversion to type %qT from type %qT",
6988 to_type, pfn_type);
6989
6990 n = get_delta_difference (TYPE_PTRMEMFUNC_OBJECT_TYPE (pfn_type),
6991 TYPE_PTRMEMFUNC_OBJECT_TYPE (to_type),
6992 force,
6993 c_cast_p, complain);
6994 if (n == error_mark_node)
6995 return error_mark_node;
6996
6997 /* We don't have to do any conversion to convert a
6998 pointer-to-member to its own type. But, we don't want to
6999 just return a PTRMEM_CST if there's an explicit cast; that
7000 cast should make the expression an invalid template argument. */
7001 if (TREE_CODE (pfn) != PTRMEM_CST)
7002 {
7003 if (same_type_p (to_type, pfn_type))
7004 return pfn;
7005 else if (integer_zerop (n))
7006 return build_reinterpret_cast (to_type, pfn,
7007 tf_warning_or_error);
7008 }
7009
7010 if (TREE_SIDE_EFFECTS (pfn))
7011 pfn = save_expr (pfn);
7012
7013 /* Obtain the function pointer and the current DELTA. */
7014 if (TREE_CODE (pfn) == PTRMEM_CST)
7015 expand_ptrmemfunc_cst (pfn, &delta, &npfn);
7016 else
7017 {
7018 npfn = build_ptrmemfunc_access_expr (pfn, pfn_identifier);
7019 delta = build_ptrmemfunc_access_expr (pfn, delta_identifier);
7020 }
7021
7022 /* Just adjust the DELTA field. */
7023 gcc_assert (same_type_ignoring_top_level_qualifiers_p
7024 (TREE_TYPE (delta), ptrdiff_type_node));
7025 if (TARGET_PTRMEMFUNC_VBIT_LOCATION == ptrmemfunc_vbit_in_delta)
7026 n = cp_build_binary_op (input_location,
7027 LSHIFT_EXPR, n, integer_one_node,
7028 tf_warning_or_error);
7029 delta = cp_build_binary_op (input_location,
7030 PLUS_EXPR, delta, n, tf_warning_or_error);
7031 return build_ptrmemfunc1 (to_type, delta, npfn);
7032 }
7033
7034 /* Handle null pointer to member function conversions. */
7035 if (null_ptr_cst_p (pfn))
7036 {
7037 pfn = build_c_cast (input_location, type, integer_zero_node);
7038 return build_ptrmemfunc1 (to_type,
7039 integer_zero_node,
7040 pfn);
7041 }
7042
7043 if (type_unknown_p (pfn))
7044 return instantiate_type (type, pfn, tf_warning_or_error);
7045
7046 fn = TREE_OPERAND (pfn, 0);
7047 gcc_assert (TREE_CODE (fn) == FUNCTION_DECL
7048 /* In a template, we will have preserved the
7049 OFFSET_REF. */
7050 || (processing_template_decl && TREE_CODE (fn) == OFFSET_REF));
7051 return make_ptrmem_cst (to_type, fn);
7052 }
7053
7054 /* Return the DELTA, IDX, PFN, and DELTA2 values for the PTRMEM_CST
7055 given by CST.
7056
7057 ??? There is no consistency as to the types returned for the above
7058 values. Some code acts as if it were a sizetype and some as if it were
7059 integer_type_node. */
7060
7061 void
7062 expand_ptrmemfunc_cst (tree cst, tree *delta, tree *pfn)
7063 {
7064 tree type = TREE_TYPE (cst);
7065 tree fn = PTRMEM_CST_MEMBER (cst);
7066 tree ptr_class, fn_class;
7067
7068 gcc_assert (TREE_CODE (fn) == FUNCTION_DECL);
7069
7070 /* The class that the function belongs to. */
7071 fn_class = DECL_CONTEXT (fn);
7072
7073 /* The class that we're creating a pointer to member of. */
7074 ptr_class = TYPE_PTRMEMFUNC_OBJECT_TYPE (type);
7075
7076 /* First, calculate the adjustment to the function's class. */
7077 *delta = get_delta_difference (fn_class, ptr_class, /*force=*/0,
7078 /*c_cast_p=*/0, tf_warning_or_error);
7079
7080 if (!DECL_VIRTUAL_P (fn))
7081 *pfn = convert (TYPE_PTRMEMFUNC_FN_TYPE (type), build_addr_func (fn));
7082 else
7083 {
7084 /* If we're dealing with a virtual function, we have to adjust 'this'
7085 again, to point to the base which provides the vtable entry for
7086 fn; the call will do the opposite adjustment. */
7087 tree orig_class = DECL_CONTEXT (fn);
7088 tree binfo = binfo_or_else (orig_class, fn_class);
7089 *delta = build2 (PLUS_EXPR, TREE_TYPE (*delta),
7090 *delta, BINFO_OFFSET (binfo));
7091 *delta = fold_if_not_in_template (*delta);
7092
7093 /* We set PFN to the vtable offset at which the function can be
7094 found, plus one (unless ptrmemfunc_vbit_in_delta, in which
7095 case delta is shifted left, and then incremented). */
7096 *pfn = DECL_VINDEX (fn);
7097 *pfn = build2 (MULT_EXPR, integer_type_node, *pfn,
7098 TYPE_SIZE_UNIT (vtable_entry_type));
7099 *pfn = fold_if_not_in_template (*pfn);
7100
7101 switch (TARGET_PTRMEMFUNC_VBIT_LOCATION)
7102 {
7103 case ptrmemfunc_vbit_in_pfn:
7104 *pfn = build2 (PLUS_EXPR, integer_type_node, *pfn,
7105 integer_one_node);
7106 *pfn = fold_if_not_in_template (*pfn);
7107 break;
7108
7109 case ptrmemfunc_vbit_in_delta:
7110 *delta = build2 (LSHIFT_EXPR, TREE_TYPE (*delta),
7111 *delta, integer_one_node);
7112 *delta = fold_if_not_in_template (*delta);
7113 *delta = build2 (PLUS_EXPR, TREE_TYPE (*delta),
7114 *delta, integer_one_node);
7115 *delta = fold_if_not_in_template (*delta);
7116 break;
7117
7118 default:
7119 gcc_unreachable ();
7120 }
7121
7122 *pfn = build_nop (TYPE_PTRMEMFUNC_FN_TYPE (type), *pfn);
7123 *pfn = fold_if_not_in_template (*pfn);
7124 }
7125 }
7126
7127 /* Return an expression for PFN from the pointer-to-member function
7128 given by T. */
7129
7130 static tree
7131 pfn_from_ptrmemfunc (tree t)
7132 {
7133 if (TREE_CODE (t) == PTRMEM_CST)
7134 {
7135 tree delta;
7136 tree pfn;
7137
7138 expand_ptrmemfunc_cst (t, &delta, &pfn);
7139 if (pfn)
7140 return pfn;
7141 }
7142
7143 return build_ptrmemfunc_access_expr (t, pfn_identifier);
7144 }
7145
7146 /* Return an expression for DELTA from the pointer-to-member function
7147 given by T. */
7148
7149 static tree
7150 delta_from_ptrmemfunc (tree t)
7151 {
7152 if (TREE_CODE (t) == PTRMEM_CST)
7153 {
7154 tree delta;
7155 tree pfn;
7156
7157 expand_ptrmemfunc_cst (t, &delta, &pfn);
7158 if (delta)
7159 return delta;
7160 }
7161
7162 return build_ptrmemfunc_access_expr (t, delta_identifier);
7163 }
7164
7165 /* Convert value RHS to type TYPE as preparation for an assignment to
7166 an lvalue of type TYPE. ERRTYPE indicates what kind of error the
7167 implicit conversion is. If FNDECL is non-NULL, we are doing the
7168 conversion in order to pass the PARMNUMth argument of FNDECL.
7169 If FNDECL is NULL, we are doing the conversion in function pointer
7170 argument passing, conversion in initialization, etc. */
7171
7172 static tree
7173 convert_for_assignment (tree type, tree rhs,
7174 impl_conv_rhs errtype, tree fndecl, int parmnum,
7175 tsubst_flags_t complain, int flags)
7176 {
7177 tree rhstype;
7178 enum tree_code coder;
7179
7180 /* Strip NON_LVALUE_EXPRs since we aren't using as an lvalue. */
7181 if (TREE_CODE (rhs) == NON_LVALUE_EXPR)
7182 rhs = TREE_OPERAND (rhs, 0);
7183
7184 rhstype = TREE_TYPE (rhs);
7185 coder = TREE_CODE (rhstype);
7186
7187 if (TREE_CODE (type) == VECTOR_TYPE && coder == VECTOR_TYPE
7188 && vector_types_convertible_p (type, rhstype, true))
7189 {
7190 rhs = mark_rvalue_use (rhs);
7191 return convert (type, rhs);
7192 }
7193
7194 if (rhs == error_mark_node || rhstype == error_mark_node)
7195 return error_mark_node;
7196 if (TREE_CODE (rhs) == TREE_LIST && TREE_VALUE (rhs) == error_mark_node)
7197 return error_mark_node;
7198
7199 /* The RHS of an assignment cannot have void type. */
7200 if (coder == VOID_TYPE)
7201 {
7202 if (complain & tf_error)
7203 error ("void value not ignored as it ought to be");
7204 return error_mark_node;
7205 }
7206
7207 /* Simplify the RHS if possible. */
7208 if (TREE_CODE (rhs) == CONST_DECL)
7209 rhs = DECL_INITIAL (rhs);
7210
7211 if (c_dialect_objc ())
7212 {
7213 int parmno;
7214 tree selector;
7215 tree rname = fndecl;
7216
7217 switch (errtype)
7218 {
7219 case ICR_ASSIGN:
7220 parmno = -1;
7221 break;
7222 case ICR_INIT:
7223 parmno = -2;
7224 break;
7225 default:
7226 selector = objc_message_selector ();
7227 parmno = parmnum;
7228 if (selector && parmno > 1)
7229 {
7230 rname = selector;
7231 parmno -= 1;
7232 }
7233 }
7234
7235 if (objc_compare_types (type, rhstype, parmno, rname))
7236 {
7237 rhs = mark_rvalue_use (rhs);
7238 return convert (type, rhs);
7239 }
7240 }
7241
7242 /* [expr.ass]
7243
7244 The expression is implicitly converted (clause _conv_) to the
7245 cv-unqualified type of the left operand.
7246
7247 We allow bad conversions here because by the time we get to this point
7248 we are committed to doing the conversion. If we end up doing a bad
7249 conversion, convert_like will complain. */
7250 if (!can_convert_arg_bad (type, rhstype, rhs, flags))
7251 {
7252 /* When -Wno-pmf-conversions is use, we just silently allow
7253 conversions from pointers-to-members to plain pointers. If
7254 the conversion doesn't work, cp_convert will complain. */
7255 if (!warn_pmf2ptr
7256 && TYPE_PTR_P (type)
7257 && TYPE_PTRMEMFUNC_P (rhstype))
7258 rhs = cp_convert (strip_top_quals (type), rhs);
7259 else
7260 {
7261 if (complain & tf_error)
7262 {
7263 /* If the right-hand side has unknown type, then it is an
7264 overloaded function. Call instantiate_type to get error
7265 messages. */
7266 if (rhstype == unknown_type_node)
7267 instantiate_type (type, rhs, tf_warning_or_error);
7268 else if (fndecl)
7269 error ("cannot convert %qT to %qT for argument %qP to %qD",
7270 rhstype, type, parmnum, fndecl);
7271 else
7272 switch (errtype)
7273 {
7274 case ICR_DEFAULT_ARGUMENT:
7275 error ("cannot convert %qT to %qT in default argument",
7276 rhstype, type);
7277 break;
7278 case ICR_ARGPASS:
7279 error ("cannot convert %qT to %qT in argument passing",
7280 rhstype, type);
7281 break;
7282 case ICR_CONVERTING:
7283 error ("cannot convert %qT to %qT",
7284 rhstype, type);
7285 break;
7286 case ICR_INIT:
7287 error ("cannot convert %qT to %qT in initialization",
7288 rhstype, type);
7289 break;
7290 case ICR_RETURN:
7291 error ("cannot convert %qT to %qT in return",
7292 rhstype, type);
7293 break;
7294 case ICR_ASSIGN:
7295 error ("cannot convert %qT to %qT in assignment",
7296 rhstype, type);
7297 break;
7298 default:
7299 gcc_unreachable();
7300 }
7301 }
7302 return error_mark_node;
7303 }
7304 }
7305 if (warn_missing_format_attribute)
7306 {
7307 const enum tree_code codel = TREE_CODE (type);
7308 if ((codel == POINTER_TYPE || codel == REFERENCE_TYPE)
7309 && coder == codel
7310 && check_missing_format_attribute (type, rhstype)
7311 && (complain & tf_warning))
7312 switch (errtype)
7313 {
7314 case ICR_ARGPASS:
7315 case ICR_DEFAULT_ARGUMENT:
7316 if (fndecl)
7317 warning (OPT_Wmissing_format_attribute,
7318 "parameter %qP of %qD might be a candidate "
7319 "for a format attribute", parmnum, fndecl);
7320 else
7321 warning (OPT_Wmissing_format_attribute,
7322 "parameter might be a candidate "
7323 "for a format attribute");
7324 break;
7325 case ICR_CONVERTING:
7326 warning (OPT_Wmissing_format_attribute,
7327 "target of conversion might be a candidate "
7328 "for a format attribute");
7329 break;
7330 case ICR_INIT:
7331 warning (OPT_Wmissing_format_attribute,
7332 "target of initialization might be a candidate "
7333 "for a format attribute");
7334 break;
7335 case ICR_RETURN:
7336 warning (OPT_Wmissing_format_attribute,
7337 "return type might be a candidate "
7338 "for a format attribute");
7339 break;
7340 case ICR_ASSIGN:
7341 warning (OPT_Wmissing_format_attribute,
7342 "left-hand side of assignment might be a candidate "
7343 "for a format attribute");
7344 break;
7345 default:
7346 gcc_unreachable();
7347 }
7348 }
7349
7350 /* If -Wparentheses, warn about a = b = c when a has type bool and b
7351 does not. */
7352 if (warn_parentheses
7353 && TREE_CODE (type) == BOOLEAN_TYPE
7354 && TREE_CODE (rhs) == MODIFY_EXPR
7355 && !TREE_NO_WARNING (rhs)
7356 && TREE_CODE (TREE_TYPE (rhs)) != BOOLEAN_TYPE
7357 && (complain & tf_warning))
7358 {
7359 location_t loc = EXPR_LOC_OR_HERE (rhs);
7360
7361 warning_at (loc, OPT_Wparentheses,
7362 "suggest parentheses around assignment used as truth value");
7363 TREE_NO_WARNING (rhs) = 1;
7364 }
7365
7366 return perform_implicit_conversion_flags (strip_top_quals (type), rhs,
7367 complain, flags);
7368 }
7369
7370 /* Convert RHS to be of type TYPE.
7371 If EXP is nonzero, it is the target of the initialization.
7372 ERRTYPE indicates what kind of error the implicit conversion is.
7373
7374 Two major differences between the behavior of
7375 `convert_for_assignment' and `convert_for_initialization'
7376 are that references are bashed in the former, while
7377 copied in the latter, and aggregates are assigned in
7378 the former (operator=) while initialized in the
7379 latter (X(X&)).
7380
7381 If using constructor make sure no conversion operator exists, if one does
7382 exist, an ambiguity exists.
7383
7384 If flags doesn't include LOOKUP_COMPLAIN, don't complain about anything. */
7385
7386 tree
7387 convert_for_initialization (tree exp, tree type, tree rhs, int flags,
7388 impl_conv_rhs errtype, tree fndecl, int parmnum,
7389 tsubst_flags_t complain)
7390 {
7391 enum tree_code codel = TREE_CODE (type);
7392 tree rhstype;
7393 enum tree_code coder;
7394
7395 /* build_c_cast puts on a NOP_EXPR to make the result not an lvalue.
7396 Strip such NOP_EXPRs, since RHS is used in non-lvalue context. */
7397 if (TREE_CODE (rhs) == NOP_EXPR
7398 && TREE_TYPE (rhs) == TREE_TYPE (TREE_OPERAND (rhs, 0))
7399 && codel != REFERENCE_TYPE)
7400 rhs = TREE_OPERAND (rhs, 0);
7401
7402 if (type == error_mark_node
7403 || rhs == error_mark_node
7404 || (TREE_CODE (rhs) == TREE_LIST && TREE_VALUE (rhs) == error_mark_node))
7405 return error_mark_node;
7406
7407 if ((TREE_CODE (TREE_TYPE (rhs)) == ARRAY_TYPE
7408 && TREE_CODE (type) != ARRAY_TYPE
7409 && (TREE_CODE (type) != REFERENCE_TYPE
7410 || TREE_CODE (TREE_TYPE (type)) != ARRAY_TYPE))
7411 || (TREE_CODE (TREE_TYPE (rhs)) == FUNCTION_TYPE
7412 && (TREE_CODE (type) != REFERENCE_TYPE
7413 || TREE_CODE (TREE_TYPE (type)) != FUNCTION_TYPE))
7414 || TREE_CODE (TREE_TYPE (rhs)) == METHOD_TYPE)
7415 rhs = decay_conversion (rhs);
7416
7417 rhstype = TREE_TYPE (rhs);
7418 coder = TREE_CODE (rhstype);
7419
7420 if (coder == ERROR_MARK)
7421 return error_mark_node;
7422
7423 /* We accept references to incomplete types, so we can
7424 return here before checking if RHS is of complete type. */
7425
7426 if (codel == REFERENCE_TYPE)
7427 {
7428 /* This should eventually happen in convert_arguments. */
7429 int savew = 0, savee = 0;
7430
7431 if (fndecl)
7432 savew = warningcount, savee = errorcount;
7433 rhs = initialize_reference (type, rhs, /*decl=*/NULL_TREE,
7434 /*cleanup=*/NULL, complain);
7435 if (fndecl)
7436 {
7437 if (warningcount > savew)
7438 warning (0, "in passing argument %P of %q+D", parmnum, fndecl);
7439 else if (errorcount > savee)
7440 error ("in passing argument %P of %q+D", parmnum, fndecl);
7441 }
7442 return rhs;
7443 }
7444
7445 if (exp != 0)
7446 exp = require_complete_type_sfinae (exp, complain);
7447 if (exp == error_mark_node)
7448 return error_mark_node;
7449
7450 rhstype = non_reference (rhstype);
7451
7452 type = complete_type (type);
7453
7454 if (DIRECT_INIT_EXPR_P (type, rhs))
7455 /* Don't try to do copy-initialization if we already have
7456 direct-initialization. */
7457 return rhs;
7458
7459 if (MAYBE_CLASS_TYPE_P (type))
7460 return perform_implicit_conversion_flags (type, rhs, complain, flags);
7461
7462 return convert_for_assignment (type, rhs, errtype, fndecl, parmnum,
7463 complain, flags);
7464 }
7465 \f
7466 /* If RETVAL is the address of, or a reference to, a local variable or
7467 temporary give an appropriate warning. */
7468
7469 static void
7470 maybe_warn_about_returning_address_of_local (tree retval)
7471 {
7472 tree valtype = TREE_TYPE (DECL_RESULT (current_function_decl));
7473 tree whats_returned = retval;
7474
7475 for (;;)
7476 {
7477 if (TREE_CODE (whats_returned) == COMPOUND_EXPR)
7478 whats_returned = TREE_OPERAND (whats_returned, 1);
7479 else if (CONVERT_EXPR_P (whats_returned)
7480 || TREE_CODE (whats_returned) == NON_LVALUE_EXPR)
7481 whats_returned = TREE_OPERAND (whats_returned, 0);
7482 else
7483 break;
7484 }
7485
7486 if (TREE_CODE (whats_returned) != ADDR_EXPR)
7487 return;
7488 whats_returned = TREE_OPERAND (whats_returned, 0);
7489
7490 if (TREE_CODE (valtype) == REFERENCE_TYPE)
7491 {
7492 if (TREE_CODE (whats_returned) == AGGR_INIT_EXPR
7493 || TREE_CODE (whats_returned) == TARGET_EXPR)
7494 {
7495 warning (0, "returning reference to temporary");
7496 return;
7497 }
7498 if (TREE_CODE (whats_returned) == VAR_DECL
7499 && DECL_NAME (whats_returned)
7500 && TEMP_NAME_P (DECL_NAME (whats_returned)))
7501 {
7502 warning (0, "reference to non-lvalue returned");
7503 return;
7504 }
7505 }
7506
7507 while (TREE_CODE (whats_returned) == COMPONENT_REF
7508 || TREE_CODE (whats_returned) == ARRAY_REF)
7509 whats_returned = TREE_OPERAND (whats_returned, 0);
7510
7511 if (DECL_P (whats_returned)
7512 && DECL_NAME (whats_returned)
7513 && DECL_FUNCTION_SCOPE_P (whats_returned)
7514 && !(TREE_STATIC (whats_returned)
7515 || TREE_PUBLIC (whats_returned)))
7516 {
7517 if (TREE_CODE (valtype) == REFERENCE_TYPE)
7518 warning (0, "reference to local variable %q+D returned",
7519 whats_returned);
7520 else
7521 warning (0, "address of local variable %q+D returned",
7522 whats_returned);
7523 return;
7524 }
7525 }
7526
7527 /* Check that returning RETVAL from the current function is valid.
7528 Return an expression explicitly showing all conversions required to
7529 change RETVAL into the function return type, and to assign it to
7530 the DECL_RESULT for the function. Set *NO_WARNING to true if
7531 code reaches end of non-void function warning shouldn't be issued
7532 on this RETURN_EXPR. */
7533
7534 tree
7535 check_return_expr (tree retval, bool *no_warning)
7536 {
7537 tree result;
7538 /* The type actually returned by the function, after any
7539 promotions. */
7540 tree valtype;
7541 int fn_returns_value_p;
7542 bool named_return_value_okay_p;
7543
7544 *no_warning = false;
7545
7546 /* A `volatile' function is one that isn't supposed to return, ever.
7547 (This is a G++ extension, used to get better code for functions
7548 that call the `volatile' function.) */
7549 if (TREE_THIS_VOLATILE (current_function_decl))
7550 warning (0, "function declared %<noreturn%> has a %<return%> statement");
7551
7552 /* Check for various simple errors. */
7553 if (DECL_DESTRUCTOR_P (current_function_decl))
7554 {
7555 if (retval)
7556 error ("returning a value from a destructor");
7557 return NULL_TREE;
7558 }
7559 else if (DECL_CONSTRUCTOR_P (current_function_decl))
7560 {
7561 if (in_function_try_handler)
7562 /* If a return statement appears in a handler of the
7563 function-try-block of a constructor, the program is ill-formed. */
7564 error ("cannot return from a handler of a function-try-block of a constructor");
7565 else if (retval)
7566 /* You can't return a value from a constructor. */
7567 error ("returning a value from a constructor");
7568 return NULL_TREE;
7569 }
7570
7571 /* As an extension, deduce lambda return type from a return statement
7572 anywhere in the body. */
7573 if (retval && LAMBDA_FUNCTION_P (current_function_decl))
7574 {
7575 tree lambda = CLASSTYPE_LAMBDA_EXPR (current_class_type);
7576 if (LAMBDA_EXPR_DEDUCE_RETURN_TYPE_P (lambda))
7577 {
7578 tree type = lambda_return_type (retval);
7579 tree oldtype = LAMBDA_EXPR_RETURN_TYPE (lambda);
7580
7581 if (VOID_TYPE_P (type))
7582 { /* Nothing. */ }
7583 else if (oldtype == NULL_TREE)
7584 {
7585 pedwarn (input_location, OPT_pedantic, "lambda return type "
7586 "can only be deduced when the return statement is "
7587 "the only statement in the function body");
7588 apply_lambda_return_type (lambda, type);
7589 }
7590 else if (!same_type_p (type, oldtype))
7591 error ("inconsistent types %qT and %qT deduced for "
7592 "lambda return type", type, oldtype);
7593 }
7594 }
7595
7596 if (processing_template_decl)
7597 {
7598 current_function_returns_value = 1;
7599 if (check_for_bare_parameter_packs (retval))
7600 retval = error_mark_node;
7601 return retval;
7602 }
7603
7604 /* When no explicit return-value is given in a function with a named
7605 return value, the named return value is used. */
7606 result = DECL_RESULT (current_function_decl);
7607 valtype = TREE_TYPE (result);
7608 gcc_assert (valtype != NULL_TREE);
7609 fn_returns_value_p = !VOID_TYPE_P (valtype);
7610 if (!retval && DECL_NAME (result) && fn_returns_value_p)
7611 retval = result;
7612
7613 /* Check for a return statement with no return value in a function
7614 that's supposed to return a value. */
7615 if (!retval && fn_returns_value_p)
7616 {
7617 permerror (input_location, "return-statement with no value, in function returning %qT",
7618 valtype);
7619 /* Clear this, so finish_function won't say that we reach the
7620 end of a non-void function (which we don't, we gave a
7621 return!). */
7622 current_function_returns_null = 0;
7623 /* And signal caller that TREE_NO_WARNING should be set on the
7624 RETURN_EXPR to avoid control reaches end of non-void function
7625 warnings in tree-cfg.c. */
7626 *no_warning = true;
7627 }
7628 /* Check for a return statement with a value in a function that
7629 isn't supposed to return a value. */
7630 else if (retval && !fn_returns_value_p)
7631 {
7632 if (VOID_TYPE_P (TREE_TYPE (retval)))
7633 /* You can return a `void' value from a function of `void'
7634 type. In that case, we have to evaluate the expression for
7635 its side-effects. */
7636 finish_expr_stmt (retval);
7637 else
7638 permerror (input_location, "return-statement with a value, in function "
7639 "returning 'void'");
7640 current_function_returns_null = 1;
7641
7642 /* There's really no value to return, after all. */
7643 return NULL_TREE;
7644 }
7645 else if (!retval)
7646 /* Remember that this function can sometimes return without a
7647 value. */
7648 current_function_returns_null = 1;
7649 else
7650 /* Remember that this function did return a value. */
7651 current_function_returns_value = 1;
7652
7653 /* Check for erroneous operands -- but after giving ourselves a
7654 chance to provide an error about returning a value from a void
7655 function. */
7656 if (error_operand_p (retval))
7657 {
7658 current_function_return_value = error_mark_node;
7659 return error_mark_node;
7660 }
7661
7662 /* Only operator new(...) throw(), can return NULL [expr.new/13]. */
7663 if ((DECL_OVERLOADED_OPERATOR_P (current_function_decl) == NEW_EXPR
7664 || DECL_OVERLOADED_OPERATOR_P (current_function_decl) == VEC_NEW_EXPR)
7665 && !TYPE_NOTHROW_P (TREE_TYPE (current_function_decl))
7666 && ! flag_check_new
7667 && retval && null_ptr_cst_p (retval))
7668 warning (0, "%<operator new%> must not return NULL unless it is "
7669 "declared %<throw()%> (or -fcheck-new is in effect)");
7670
7671 /* Effective C++ rule 15. See also start_function. */
7672 if (warn_ecpp
7673 && DECL_NAME (current_function_decl) == ansi_assopname(NOP_EXPR))
7674 {
7675 bool warn = true;
7676
7677 /* The function return type must be a reference to the current
7678 class. */
7679 if (TREE_CODE (valtype) == REFERENCE_TYPE
7680 && same_type_ignoring_top_level_qualifiers_p
7681 (TREE_TYPE (valtype), TREE_TYPE (current_class_ref)))
7682 {
7683 /* Returning '*this' is obviously OK. */
7684 if (retval == current_class_ref)
7685 warn = false;
7686 /* If we are calling a function whose return type is the same of
7687 the current class reference, it is ok. */
7688 else if (TREE_CODE (retval) == INDIRECT_REF
7689 && TREE_CODE (TREE_OPERAND (retval, 0)) == CALL_EXPR)
7690 warn = false;
7691 }
7692
7693 if (warn)
7694 warning (OPT_Weffc__, "%<operator=%> should return a reference to %<*this%>");
7695 }
7696
7697 /* The fabled Named Return Value optimization, as per [class.copy]/15:
7698
7699 [...] For a function with a class return type, if the expression
7700 in the return statement is the name of a local object, and the cv-
7701 unqualified type of the local object is the same as the function
7702 return type, an implementation is permitted to omit creating the tem-
7703 porary object to hold the function return value [...]
7704
7705 So, if this is a value-returning function that always returns the same
7706 local variable, remember it.
7707
7708 It might be nice to be more flexible, and choose the first suitable
7709 variable even if the function sometimes returns something else, but
7710 then we run the risk of clobbering the variable we chose if the other
7711 returned expression uses the chosen variable somehow. And people expect
7712 this restriction, anyway. (jason 2000-11-19)
7713
7714 See finish_function and finalize_nrv for the rest of this optimization. */
7715
7716 named_return_value_okay_p =
7717 (retval != NULL_TREE
7718 /* Must be a local, automatic variable. */
7719 && TREE_CODE (retval) == VAR_DECL
7720 && DECL_CONTEXT (retval) == current_function_decl
7721 && ! TREE_STATIC (retval)
7722 && ! DECL_ANON_UNION_VAR_P (retval)
7723 && (DECL_ALIGN (retval)
7724 >= DECL_ALIGN (DECL_RESULT (current_function_decl)))
7725 /* The cv-unqualified type of the returned value must be the
7726 same as the cv-unqualified return type of the
7727 function. */
7728 && same_type_p ((TYPE_MAIN_VARIANT (TREE_TYPE (retval))),
7729 (TYPE_MAIN_VARIANT
7730 (TREE_TYPE (TREE_TYPE (current_function_decl)))))
7731 /* And the returned value must be non-volatile. */
7732 && ! TYPE_VOLATILE (TREE_TYPE (retval)));
7733
7734 if (fn_returns_value_p && flag_elide_constructors)
7735 {
7736 if (named_return_value_okay_p
7737 && (current_function_return_value == NULL_TREE
7738 || current_function_return_value == retval))
7739 current_function_return_value = retval;
7740 else
7741 current_function_return_value = error_mark_node;
7742 }
7743
7744 /* We don't need to do any conversions when there's nothing being
7745 returned. */
7746 if (!retval)
7747 return NULL_TREE;
7748
7749 /* Do any required conversions. */
7750 if (retval == result || DECL_CONSTRUCTOR_P (current_function_decl))
7751 /* No conversions are required. */
7752 ;
7753 else
7754 {
7755 /* The type the function is declared to return. */
7756 tree functype = TREE_TYPE (TREE_TYPE (current_function_decl));
7757 int flags = LOOKUP_NORMAL | LOOKUP_ONLYCONVERTING;
7758
7759 /* The functype's return type will have been set to void, if it
7760 was an incomplete type. Just treat this as 'return;' */
7761 if (VOID_TYPE_P (functype))
7762 return error_mark_node;
7763
7764 /* Under C++0x [12.8/16 class.copy], a returned lvalue is sometimes
7765 treated as an rvalue for the purposes of overload resolution to
7766 favor move constructors over copy constructors.
7767
7768 Note that these conditions are similar to, but not as strict as,
7769 the conditions for the named return value optimization. */
7770 if ((cxx_dialect != cxx98)
7771 && (TREE_CODE (retval) == VAR_DECL
7772 || TREE_CODE (retval) == PARM_DECL)
7773 && DECL_CONTEXT (retval) == current_function_decl
7774 && !TREE_STATIC (retval)
7775 && same_type_p ((TYPE_MAIN_VARIANT (TREE_TYPE (retval))),
7776 (TYPE_MAIN_VARIANT
7777 (TREE_TYPE (TREE_TYPE (current_function_decl)))))
7778 /* This is only interesting for class type. */
7779 && CLASS_TYPE_P (TREE_TYPE (TREE_TYPE (current_function_decl))))
7780 flags = flags | LOOKUP_PREFER_RVALUE;
7781
7782 /* First convert the value to the function's return type, then
7783 to the type of return value's location to handle the
7784 case that functype is smaller than the valtype. */
7785 retval = convert_for_initialization
7786 (NULL_TREE, functype, retval, flags, ICR_RETURN, NULL_TREE, 0,
7787 tf_warning_or_error);
7788 retval = convert (valtype, retval);
7789
7790 /* If the conversion failed, treat this just like `return;'. */
7791 if (retval == error_mark_node)
7792 return retval;
7793 /* We can't initialize a register from a AGGR_INIT_EXPR. */
7794 else if (! cfun->returns_struct
7795 && TREE_CODE (retval) == TARGET_EXPR
7796 && TREE_CODE (TREE_OPERAND (retval, 1)) == AGGR_INIT_EXPR)
7797 retval = build2 (COMPOUND_EXPR, TREE_TYPE (retval), retval,
7798 TREE_OPERAND (retval, 0));
7799 else
7800 maybe_warn_about_returning_address_of_local (retval);
7801 }
7802
7803 /* Actually copy the value returned into the appropriate location. */
7804 if (retval && retval != result)
7805 retval = build2 (INIT_EXPR, TREE_TYPE (result), result, retval);
7806
7807 return retval;
7808 }
7809
7810 \f
7811 /* Returns nonzero if the pointer-type FROM can be converted to the
7812 pointer-type TO via a qualification conversion. If CONSTP is -1,
7813 then we return nonzero if the pointers are similar, and the
7814 cv-qualification signature of FROM is a proper subset of that of TO.
7815
7816 If CONSTP is positive, then all outer pointers have been
7817 const-qualified. */
7818
7819 static int
7820 comp_ptr_ttypes_real (tree to, tree from, int constp)
7821 {
7822 bool to_more_cv_qualified = false;
7823 bool is_opaque_pointer = false;
7824
7825 for (; ; to = TREE_TYPE (to), from = TREE_TYPE (from))
7826 {
7827 if (TREE_CODE (to) != TREE_CODE (from))
7828 return 0;
7829
7830 if (TREE_CODE (from) == OFFSET_TYPE
7831 && !same_type_p (TYPE_OFFSET_BASETYPE (from),
7832 TYPE_OFFSET_BASETYPE (to)))
7833 return 0;
7834
7835 /* Const and volatile mean something different for function types,
7836 so the usual checks are not appropriate. */
7837 if (TREE_CODE (to) != FUNCTION_TYPE && TREE_CODE (to) != METHOD_TYPE)
7838 {
7839 if (!at_least_as_qualified_p (to, from))
7840 return 0;
7841
7842 if (!at_least_as_qualified_p (from, to))
7843 {
7844 if (constp == 0)
7845 return 0;
7846 to_more_cv_qualified = true;
7847 }
7848
7849 if (constp > 0)
7850 constp &= TYPE_READONLY (to);
7851 }
7852
7853 if (TREE_CODE (to) == VECTOR_TYPE)
7854 is_opaque_pointer = vector_targets_convertible_p (to, from);
7855
7856 if (TREE_CODE (to) != POINTER_TYPE && !TYPE_PTRMEM_P (to))
7857 return ((constp >= 0 || to_more_cv_qualified)
7858 && (is_opaque_pointer
7859 || same_type_ignoring_top_level_qualifiers_p (to, from)));
7860 }
7861 }
7862
7863 /* When comparing, say, char ** to char const **, this function takes
7864 the 'char *' and 'char const *'. Do not pass non-pointer/reference
7865 types to this function. */
7866
7867 int
7868 comp_ptr_ttypes (tree to, tree from)
7869 {
7870 return comp_ptr_ttypes_real (to, from, 1);
7871 }
7872
7873 /* Returns true iff FNTYPE is a non-class type that involves
7874 error_mark_node. We can get FUNCTION_TYPE with buried error_mark_node
7875 if a parameter type is ill-formed. */
7876
7877 bool
7878 error_type_p (const_tree type)
7879 {
7880 tree t;
7881
7882 switch (TREE_CODE (type))
7883 {
7884 case ERROR_MARK:
7885 return true;
7886
7887 case POINTER_TYPE:
7888 case REFERENCE_TYPE:
7889 case OFFSET_TYPE:
7890 return error_type_p (TREE_TYPE (type));
7891
7892 case FUNCTION_TYPE:
7893 case METHOD_TYPE:
7894 if (error_type_p (TREE_TYPE (type)))
7895 return true;
7896 for (t = TYPE_ARG_TYPES (type); t; t = TREE_CHAIN (t))
7897 if (error_type_p (TREE_VALUE (t)))
7898 return true;
7899 return false;
7900
7901 case RECORD_TYPE:
7902 if (TYPE_PTRMEMFUNC_P (type))
7903 return error_type_p (TYPE_PTRMEMFUNC_FN_TYPE (type));
7904 return false;
7905
7906 default:
7907 return false;
7908 }
7909 }
7910
7911 /* Returns 1 if to and from are (possibly multi-level) pointers to the same
7912 type or inheritance-related types, regardless of cv-quals. */
7913
7914 int
7915 ptr_reasonably_similar (const_tree to, const_tree from)
7916 {
7917 for (; ; to = TREE_TYPE (to), from = TREE_TYPE (from))
7918 {
7919 /* Any target type is similar enough to void. */
7920 if (TREE_CODE (to) == VOID_TYPE)
7921 return !error_type_p (from);
7922 if (TREE_CODE (from) == VOID_TYPE)
7923 return !error_type_p (to);
7924
7925 if (TREE_CODE (to) != TREE_CODE (from))
7926 return 0;
7927
7928 if (TREE_CODE (from) == OFFSET_TYPE
7929 && comptypes (TYPE_OFFSET_BASETYPE (to),
7930 TYPE_OFFSET_BASETYPE (from),
7931 COMPARE_BASE | COMPARE_DERIVED))
7932 continue;
7933
7934 if (TREE_CODE (to) == VECTOR_TYPE
7935 && vector_types_convertible_p (to, from, false))
7936 return 1;
7937
7938 if (TREE_CODE (to) == INTEGER_TYPE
7939 && TYPE_PRECISION (to) == TYPE_PRECISION (from))
7940 return 1;
7941
7942 if (TREE_CODE (to) == FUNCTION_TYPE)
7943 return !error_type_p (to) && !error_type_p (from);
7944
7945 if (TREE_CODE (to) != POINTER_TYPE)
7946 return comptypes
7947 (TYPE_MAIN_VARIANT (to), TYPE_MAIN_VARIANT (from),
7948 COMPARE_BASE | COMPARE_DERIVED);
7949 }
7950 }
7951
7952 /* Return true if TO and FROM (both of which are POINTER_TYPEs or
7953 pointer-to-member types) are the same, ignoring cv-qualification at
7954 all levels. */
7955
7956 bool
7957 comp_ptr_ttypes_const (tree to, tree from)
7958 {
7959 bool is_opaque_pointer = false;
7960
7961 for (; ; to = TREE_TYPE (to), from = TREE_TYPE (from))
7962 {
7963 if (TREE_CODE (to) != TREE_CODE (from))
7964 return false;
7965
7966 if (TREE_CODE (from) == OFFSET_TYPE
7967 && same_type_p (TYPE_OFFSET_BASETYPE (from),
7968 TYPE_OFFSET_BASETYPE (to)))
7969 continue;
7970
7971 if (TREE_CODE (to) == VECTOR_TYPE)
7972 is_opaque_pointer = vector_targets_convertible_p (to, from);
7973
7974 if (TREE_CODE (to) != POINTER_TYPE)
7975 return (is_opaque_pointer
7976 || same_type_ignoring_top_level_qualifiers_p (to, from));
7977 }
7978 }
7979
7980 /* Returns the type qualifiers for this type, including the qualifiers on the
7981 elements for an array type. */
7982
7983 int
7984 cp_type_quals (const_tree type)
7985 {
7986 int quals;
7987 /* This CONST_CAST is okay because strip_array_types returns its
7988 argument unmodified and we assign it to a const_tree. */
7989 type = strip_array_types (CONST_CAST_TREE (type));
7990 if (type == error_mark_node
7991 /* Quals on a FUNCTION_TYPE are memfn quals. */
7992 || TREE_CODE (type) == FUNCTION_TYPE)
7993 return TYPE_UNQUALIFIED;
7994 quals = TYPE_QUALS (type);
7995 /* METHOD and REFERENCE_TYPEs should never have quals. */
7996 gcc_assert ((TREE_CODE (type) != METHOD_TYPE
7997 && TREE_CODE (type) != REFERENCE_TYPE)
7998 || ((quals & (TYPE_QUAL_CONST|TYPE_QUAL_VOLATILE))
7999 == TYPE_UNQUALIFIED));
8000 return quals;
8001 }
8002
8003 /* Returns the function-cv-quals for TYPE, which must be a FUNCTION_TYPE or
8004 METHOD_TYPE. */
8005
8006 int
8007 type_memfn_quals (const_tree type)
8008 {
8009 if (TREE_CODE (type) == FUNCTION_TYPE)
8010 return TYPE_QUALS (type);
8011 else if (TREE_CODE (type) == METHOD_TYPE)
8012 return cp_type_quals (TREE_TYPE (TREE_VALUE (TYPE_ARG_TYPES (type))));
8013 else
8014 gcc_unreachable ();
8015 }
8016
8017 /* Returns the FUNCTION_TYPE TYPE with its function-cv-quals changed to
8018 MEMFN_QUALS. */
8019
8020 tree
8021 apply_memfn_quals (tree type, cp_cv_quals memfn_quals)
8022 {
8023 /* Could handle METHOD_TYPE here if necessary. */
8024 gcc_assert (TREE_CODE (type) == FUNCTION_TYPE);
8025 if (TYPE_QUALS (type) == memfn_quals)
8026 return type;
8027 /* This should really have a different TYPE_MAIN_VARIANT, but that gets
8028 complex. */
8029 return build_qualified_type (type, memfn_quals);
8030 }
8031
8032 /* Returns nonzero if TYPE is const or volatile. */
8033
8034 bool
8035 cv_qualified_p (const_tree type)
8036 {
8037 int quals = cp_type_quals (type);
8038 return (quals & (TYPE_QUAL_CONST|TYPE_QUAL_VOLATILE)) != 0;
8039 }
8040
8041 /* Returns nonzero if the TYPE contains a mutable member. */
8042
8043 bool
8044 cp_has_mutable_p (const_tree type)
8045 {
8046 /* This CONST_CAST is okay because strip_array_types returns its
8047 argument unmodified and we assign it to a const_tree. */
8048 type = strip_array_types (CONST_CAST_TREE(type));
8049
8050 return CLASS_TYPE_P (type) && CLASSTYPE_HAS_MUTABLE (type);
8051 }
8052
8053 /* Set TREE_READONLY and TREE_VOLATILE on DECL as indicated by the
8054 TYPE_QUALS. For a VAR_DECL, this may be an optimistic
8055 approximation. In particular, consider:
8056
8057 int f();
8058 struct S { int i; };
8059 const S s = { f(); }
8060
8061 Here, we will make "s" as TREE_READONLY (because it is declared
8062 "const") -- only to reverse ourselves upon seeing that the
8063 initializer is non-constant. */
8064
8065 void
8066 cp_apply_type_quals_to_decl (int type_quals, tree decl)
8067 {
8068 tree type = TREE_TYPE (decl);
8069
8070 if (type == error_mark_node)
8071 return;
8072
8073 if (TREE_CODE (decl) == TYPE_DECL)
8074 return;
8075
8076 gcc_assert (!(TREE_CODE (type) == FUNCTION_TYPE
8077 && type_quals != TYPE_UNQUALIFIED));
8078
8079 /* Avoid setting TREE_READONLY incorrectly. */
8080 if (/* If the object has a constructor, the constructor may modify
8081 the object. */
8082 TYPE_NEEDS_CONSTRUCTING (type)
8083 /* If the type isn't complete, we don't know yet if it will need
8084 constructing. */
8085 || !COMPLETE_TYPE_P (type)
8086 /* If the type has a mutable component, that component might be
8087 modified. */
8088 || TYPE_HAS_MUTABLE_P (type))
8089 type_quals &= ~TYPE_QUAL_CONST;
8090
8091 c_apply_type_quals_to_decl (type_quals, decl);
8092 }
8093
8094 /* Subroutine of casts_away_constness. Make T1 and T2 point at
8095 exemplar types such that casting T1 to T2 is casting away constness
8096 if and only if there is no implicit conversion from T1 to T2. */
8097
8098 static void
8099 casts_away_constness_r (tree *t1, tree *t2)
8100 {
8101 int quals1;
8102 int quals2;
8103
8104 /* [expr.const.cast]
8105
8106 For multi-level pointer to members and multi-level mixed pointers
8107 and pointers to members (conv.qual), the "member" aspect of a
8108 pointer to member level is ignored when determining if a const
8109 cv-qualifier has been cast away. */
8110 /* [expr.const.cast]
8111
8112 For two pointer types:
8113
8114 X1 is T1cv1,1 * ... cv1,N * where T1 is not a pointer type
8115 X2 is T2cv2,1 * ... cv2,M * where T2 is not a pointer type
8116 K is min(N,M)
8117
8118 casting from X1 to X2 casts away constness if, for a non-pointer
8119 type T there does not exist an implicit conversion (clause
8120 _conv_) from:
8121
8122 Tcv1,(N-K+1) * cv1,(N-K+2) * ... cv1,N *
8123
8124 to
8125
8126 Tcv2,(M-K+1) * cv2,(M-K+2) * ... cv2,M *. */
8127 if ((!TYPE_PTR_P (*t1) && !TYPE_PTRMEM_P (*t1))
8128 || (!TYPE_PTR_P (*t2) && !TYPE_PTRMEM_P (*t2)))
8129 {
8130 *t1 = cp_build_qualified_type (void_type_node,
8131 cp_type_quals (*t1));
8132 *t2 = cp_build_qualified_type (void_type_node,
8133 cp_type_quals (*t2));
8134 return;
8135 }
8136
8137 quals1 = cp_type_quals (*t1);
8138 quals2 = cp_type_quals (*t2);
8139
8140 if (TYPE_PTRMEM_P (*t1))
8141 *t1 = TYPE_PTRMEM_POINTED_TO_TYPE (*t1);
8142 else
8143 *t1 = TREE_TYPE (*t1);
8144 if (TYPE_PTRMEM_P (*t2))
8145 *t2 = TYPE_PTRMEM_POINTED_TO_TYPE (*t2);
8146 else
8147 *t2 = TREE_TYPE (*t2);
8148
8149 casts_away_constness_r (t1, t2);
8150 *t1 = build_pointer_type (*t1);
8151 *t2 = build_pointer_type (*t2);
8152 *t1 = cp_build_qualified_type (*t1, quals1);
8153 *t2 = cp_build_qualified_type (*t2, quals2);
8154 }
8155
8156 /* Returns nonzero if casting from TYPE1 to TYPE2 casts away
8157 constness.
8158
8159 ??? This function returns non-zero if casting away qualifiers not
8160 just const. We would like to return to the caller exactly which
8161 qualifiers are casted away to give more accurate diagnostics.
8162 */
8163
8164 static bool
8165 casts_away_constness (tree t1, tree t2)
8166 {
8167 if (TREE_CODE (t2) == REFERENCE_TYPE)
8168 {
8169 /* [expr.const.cast]
8170
8171 Casting from an lvalue of type T1 to an lvalue of type T2
8172 using a reference cast casts away constness if a cast from an
8173 rvalue of type "pointer to T1" to the type "pointer to T2"
8174 casts away constness. */
8175 t1 = (TREE_CODE (t1) == REFERENCE_TYPE ? TREE_TYPE (t1) : t1);
8176 return casts_away_constness (build_pointer_type (t1),
8177 build_pointer_type (TREE_TYPE (t2)));
8178 }
8179
8180 if (TYPE_PTRMEM_P (t1) && TYPE_PTRMEM_P (t2))
8181 /* [expr.const.cast]
8182
8183 Casting from an rvalue of type "pointer to data member of X
8184 of type T1" to the type "pointer to data member of Y of type
8185 T2" casts away constness if a cast from an rvalue of type
8186 "pointer to T1" to the type "pointer to T2" casts away
8187 constness. */
8188 return casts_away_constness
8189 (build_pointer_type (TYPE_PTRMEM_POINTED_TO_TYPE (t1)),
8190 build_pointer_type (TYPE_PTRMEM_POINTED_TO_TYPE (t2)));
8191
8192 /* Casting away constness is only something that makes sense for
8193 pointer or reference types. */
8194 if (TREE_CODE (t1) != POINTER_TYPE
8195 || TREE_CODE (t2) != POINTER_TYPE)
8196 return false;
8197
8198 /* Top-level qualifiers don't matter. */
8199 t1 = TYPE_MAIN_VARIANT (t1);
8200 t2 = TYPE_MAIN_VARIANT (t2);
8201 casts_away_constness_r (&t1, &t2);
8202 if (!can_convert (t2, t1))
8203 return true;
8204
8205 return false;
8206 }
8207
8208 /* If T is a REFERENCE_TYPE return the type to which T refers.
8209 Otherwise, return T itself. */
8210
8211 tree
8212 non_reference (tree t)
8213 {
8214 if (TREE_CODE (t) == REFERENCE_TYPE)
8215 t = TREE_TYPE (t);
8216 return t;
8217 }
8218
8219
8220 /* Return nonzero if REF is an lvalue valid for this language;
8221 otherwise, print an error message and return zero. USE says
8222 how the lvalue is being used and so selects the error message. */
8223
8224 int
8225 lvalue_or_else (tree ref, enum lvalue_use use, tsubst_flags_t complain)
8226 {
8227 cp_lvalue_kind kind = lvalue_kind (ref);
8228
8229 if (kind == clk_none)
8230 {
8231 if (complain & tf_error)
8232 lvalue_error (input_location, use);
8233 return 0;
8234 }
8235 else if (kind & (clk_rvalueref|clk_class))
8236 {
8237 if (!(complain & tf_error))
8238 return 0;
8239 if (kind & clk_class)
8240 /* Make this a permerror because we used to accept it. */
8241 permerror (input_location, "using temporary as lvalue");
8242 else
8243 error ("using xvalue (rvalue reference) as lvalue");
8244 }
8245 return 1;
8246 }
8247