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 Free Software Foundation, Inc.
4 Hacked by Michael Tiemann (tiemann@cygnus.com)
6 This file is part of GCC.
8 GCC is free software; you can redistribute it and/or modify
9 it under the terms of the GNU General Public License as published by
10 the Free Software Foundation; either version 2, or (at your option)
13 GCC is distributed in the hope that it will be useful,
14 but WITHOUT ANY WARRANTY; without even the implied warranty of
15 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 GNU General Public License for more details.
18 You should have received a copy of the GNU General Public License
19 along with GCC; see the file COPYING. If not, write to
20 the Free Software Foundation, 51 Franklin Street, Fifth Floor,
21 Boston, MA 02110-1301, USA. */
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. */
31 #include "coretypes.h"
41 #include "diagnostic.h"
48 static tree pfn_from_ptrmemfunc (tree);
49 static tree convert_for_assignment (tree, tree, const char *, tree, int);
50 static tree cp_pointer_int_sum (enum tree_code, tree, tree);
51 static tree rationalize_conditional_expr (enum tree_code, tree);
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 (tree, tree, bool);
55 static tree common_base_type (tree, tree);
56 static tree pointer_diff (tree, tree, tree);
57 static tree get_delta_difference (tree, tree, bool, bool);
58 static void casts_away_constness_r (tree *, tree *);
59 static bool casts_away_constness (tree, tree);
60 static void maybe_warn_about_returning_address_of_local (tree);
61 static tree lookup_destructor (tree, tree, tree);
62 static tree convert_arguments (tree, tree, tree, int);
64 /* Do `exp = require_complete_type (exp);' to make sure exp
65 does not have an incomplete type. (That includes void types.)
66 Returns the error_mark_node if the VALUE does not have
67 complete type when this function returns. */
70 require_complete_type (tree value)
74 if (processing_template_decl || value == error_mark_node)
77 if (TREE_CODE (value) == OVERLOAD)
78 type = unknown_type_node;
80 type = TREE_TYPE (value);
82 if (type == error_mark_node)
83 return error_mark_node;
85 /* First, detect a valid value with a complete type. */
86 if (COMPLETE_TYPE_P (type))
89 if (complete_type_or_else (type, value))
92 return error_mark_node;
95 /* Try to complete TYPE, if it is incomplete. For example, if TYPE is
96 a template instantiation, do the instantiation. Returns TYPE,
97 whether or not it could be completed, unless something goes
98 horribly wrong, in which case the error_mark_node is returned. */
101 complete_type (tree type)
103 if (type == NULL_TREE)
104 /* Rather than crash, we return something sure to cause an error
106 return error_mark_node;
108 if (type == error_mark_node || COMPLETE_TYPE_P (type))
110 else if (TREE_CODE (type) == ARRAY_TYPE && TYPE_DOMAIN (type))
112 tree t = complete_type (TREE_TYPE (type));
113 unsigned int needs_constructing, has_nontrivial_dtor;
114 if (COMPLETE_TYPE_P (t) && !dependent_type_p (type))
117 = TYPE_NEEDS_CONSTRUCTING (TYPE_MAIN_VARIANT (t));
119 = TYPE_HAS_NONTRIVIAL_DESTRUCTOR (TYPE_MAIN_VARIANT (t));
120 for (t = TYPE_MAIN_VARIANT (type); t; t = TYPE_NEXT_VARIANT (t))
122 TYPE_NEEDS_CONSTRUCTING (t) = needs_constructing;
123 TYPE_HAS_NONTRIVIAL_DESTRUCTOR (t) = has_nontrivial_dtor;
126 else if (CLASS_TYPE_P (type) && CLASSTYPE_TEMPLATE_INSTANTIATION (type))
127 instantiate_class_template (TYPE_MAIN_VARIANT (type));
132 /* Like complete_type, but issue an error if the TYPE cannot be completed.
133 VALUE is used for informative diagnostics.
134 Returns NULL_TREE if the type cannot be made complete. */
137 complete_type_or_else (tree type, tree value)
139 type = complete_type (type);
140 if (type == error_mark_node)
141 /* We already issued an error. */
143 else if (!COMPLETE_TYPE_P (type))
145 cxx_incomplete_type_diagnostic (value, type, 0);
152 /* Return truthvalue of whether type of EXP is instantiated. */
155 type_unknown_p (tree exp)
157 return (TREE_CODE (exp) == TREE_LIST
158 || TREE_TYPE (exp) == unknown_type_node);
162 /* Return the common type of two parameter lists.
163 We assume that comptypes has already been done and returned 1;
164 if that isn't so, this may crash.
166 As an optimization, free the space we allocate if the parameter
167 lists are already common. */
170 commonparms (tree p1, tree p2)
172 tree oldargs = p1, newargs, n;
176 len = list_length (p1);
177 newargs = tree_last (p1);
179 if (newargs == void_list_node)
188 newargs = tree_cons (NULL_TREE, NULL_TREE, newargs);
193 p1 = TREE_CHAIN (p1), p2 = TREE_CHAIN (p2), n = TREE_CHAIN (n), i++)
195 if (TREE_PURPOSE (p1) && !TREE_PURPOSE (p2))
197 TREE_PURPOSE (n) = TREE_PURPOSE (p1);
200 else if (! TREE_PURPOSE (p1))
202 if (TREE_PURPOSE (p2))
204 TREE_PURPOSE (n) = TREE_PURPOSE (p2);
210 if (1 != simple_cst_equal (TREE_PURPOSE (p1), TREE_PURPOSE (p2)))
212 TREE_PURPOSE (n) = TREE_PURPOSE (p2);
214 if (TREE_VALUE (p1) != TREE_VALUE (p2))
217 TREE_VALUE (n) = merge_types (TREE_VALUE (p1), TREE_VALUE (p2));
220 TREE_VALUE (n) = TREE_VALUE (p1);
228 /* Given a type, perhaps copied for a typedef,
229 find the "original" version of it. */
231 original_type (tree t)
233 int quals = cp_type_quals (t);
234 while (t != error_mark_node
235 && TYPE_NAME (t) != NULL_TREE)
237 tree x = TYPE_NAME (t);
238 if (TREE_CODE (x) != TYPE_DECL)
240 x = DECL_ORIGINAL_TYPE (x);
245 return cp_build_qualified_type (t, quals);
248 /* T1 and T2 are arithmetic or enumeration types. Return the type
249 that will result from the "usual arithmetic conversions" on T1 and
250 T2 as described in [expr]. */
253 type_after_usual_arithmetic_conversions (tree t1, tree t2)
255 enum tree_code code1 = TREE_CODE (t1);
256 enum tree_code code2 = TREE_CODE (t2);
259 /* FIXME: Attributes. */
260 gcc_assert (ARITHMETIC_TYPE_P (t1)
261 || TREE_CODE (t1) == COMPLEX_TYPE
262 || TREE_CODE (t1) == VECTOR_TYPE
263 || TREE_CODE (t1) == ENUMERAL_TYPE);
264 gcc_assert (ARITHMETIC_TYPE_P (t2)
265 || TREE_CODE (t2) == COMPLEX_TYPE
266 || TREE_CODE (t2) == VECTOR_TYPE
267 || TREE_CODE (t2) == ENUMERAL_TYPE);
269 /* In what follows, we slightly generalize the rules given in [expr] so
270 as to deal with `long long' and `complex'. First, merge the
272 attributes = (*targetm.merge_type_attributes) (t1, t2);
274 /* If one type is complex, form the common type of the non-complex
275 components, then make that complex. Use T1 or T2 if it is the
277 if (code1 == COMPLEX_TYPE || code2 == COMPLEX_TYPE)
279 tree subtype1 = code1 == COMPLEX_TYPE ? TREE_TYPE (t1) : t1;
280 tree subtype2 = code2 == COMPLEX_TYPE ? TREE_TYPE (t2) : t2;
282 = type_after_usual_arithmetic_conversions (subtype1, subtype2);
284 if (code1 == COMPLEX_TYPE && TREE_TYPE (t1) == subtype)
285 return build_type_attribute_variant (t1, attributes);
286 else if (code2 == COMPLEX_TYPE && TREE_TYPE (t2) == subtype)
287 return build_type_attribute_variant (t2, attributes);
289 return build_type_attribute_variant (build_complex_type (subtype),
293 if (code1 == VECTOR_TYPE)
295 /* When we get here we should have two vectors of the same size.
296 Just prefer the unsigned one if present. */
297 if (TYPE_UNSIGNED (t1))
298 return build_type_attribute_variant (t1, attributes);
300 return build_type_attribute_variant (t2, attributes);
303 /* If only one is real, use it as the result. */
304 if (code1 == REAL_TYPE && code2 != REAL_TYPE)
305 return build_type_attribute_variant (t1, attributes);
306 if (code2 == REAL_TYPE && code1 != REAL_TYPE)
307 return build_type_attribute_variant (t2, attributes);
309 /* Perform the integral promotions. */
310 if (code1 != REAL_TYPE)
312 t1 = type_promotes_to (t1);
313 t2 = type_promotes_to (t2);
316 /* Both real or both integers; use the one with greater precision. */
317 if (TYPE_PRECISION (t1) > TYPE_PRECISION (t2))
318 return build_type_attribute_variant (t1, attributes);
319 else if (TYPE_PRECISION (t2) > TYPE_PRECISION (t1))
320 return build_type_attribute_variant (t2, attributes);
322 /* The types are the same; no need to do anything fancy. */
323 if (TYPE_MAIN_VARIANT (t1) == TYPE_MAIN_VARIANT (t2))
324 return build_type_attribute_variant (t1, attributes);
326 if (code1 != REAL_TYPE)
328 /* If one is unsigned long long, then convert the other to unsigned
330 if (same_type_p (TYPE_MAIN_VARIANT (t1), long_long_unsigned_type_node)
331 || same_type_p (TYPE_MAIN_VARIANT (t2), long_long_unsigned_type_node))
332 return build_type_attribute_variant (long_long_unsigned_type_node,
334 /* If one is a long long, and the other is an unsigned long, and
335 long long can represent all the values of an unsigned long, then
336 convert to a long long. Otherwise, convert to an unsigned long
337 long. Otherwise, if either operand is long long, convert the
340 Since we're here, we know the TYPE_PRECISION is the same;
341 therefore converting to long long cannot represent all the values
342 of an unsigned long, so we choose unsigned long long in that
344 if (same_type_p (TYPE_MAIN_VARIANT (t1), long_long_integer_type_node)
345 || same_type_p (TYPE_MAIN_VARIANT (t2), long_long_integer_type_node))
347 tree t = ((TYPE_UNSIGNED (t1) || TYPE_UNSIGNED (t2))
348 ? long_long_unsigned_type_node
349 : long_long_integer_type_node);
350 return build_type_attribute_variant (t, attributes);
353 /* Go through the same procedure, but for longs. */
354 if (same_type_p (TYPE_MAIN_VARIANT (t1), long_unsigned_type_node)
355 || same_type_p (TYPE_MAIN_VARIANT (t2), long_unsigned_type_node))
356 return build_type_attribute_variant (long_unsigned_type_node,
358 if (same_type_p (TYPE_MAIN_VARIANT (t1), long_integer_type_node)
359 || same_type_p (TYPE_MAIN_VARIANT (t2), long_integer_type_node))
361 tree t = ((TYPE_UNSIGNED (t1) || TYPE_UNSIGNED (t2))
362 ? long_unsigned_type_node : long_integer_type_node);
363 return build_type_attribute_variant (t, attributes);
365 /* Otherwise prefer the unsigned one. */
366 if (TYPE_UNSIGNED (t1))
367 return build_type_attribute_variant (t1, attributes);
369 return build_type_attribute_variant (t2, attributes);
373 if (same_type_p (TYPE_MAIN_VARIANT (t1), long_double_type_node)
374 || same_type_p (TYPE_MAIN_VARIANT (t2), long_double_type_node))
375 return build_type_attribute_variant (long_double_type_node,
377 if (same_type_p (TYPE_MAIN_VARIANT (t1), double_type_node)
378 || same_type_p (TYPE_MAIN_VARIANT (t2), double_type_node))
379 return build_type_attribute_variant (double_type_node,
381 if (same_type_p (TYPE_MAIN_VARIANT (t1), float_type_node)
382 || same_type_p (TYPE_MAIN_VARIANT (t2), float_type_node))
383 return build_type_attribute_variant (float_type_node,
386 /* Two floating-point types whose TYPE_MAIN_VARIANTs are none of
387 the standard C++ floating-point types. Logic earlier in this
388 function has already eliminated the possibility that
389 TYPE_PRECISION (t2) != TYPE_PRECISION (t1), so there's no
390 compelling reason to choose one or the other. */
391 return build_type_attribute_variant (t1, attributes);
395 /* Subroutine of composite_pointer_type to implement the recursive
396 case. See that function for documentation fo the parameters. */
399 composite_pointer_type_r (tree t1, tree t2, const char* location)
406 /* Determine the types pointed to by T1 and T2. */
407 if (TREE_CODE (t1) == POINTER_TYPE)
409 pointee1 = TREE_TYPE (t1);
410 pointee2 = TREE_TYPE (t2);
414 pointee1 = TYPE_PTRMEM_POINTED_TO_TYPE (t1);
415 pointee2 = TYPE_PTRMEM_POINTED_TO_TYPE (t2);
420 Otherwise, the composite pointer type is a pointer type
421 similar (_conv.qual_) to the type of one of the operands,
422 with a cv-qualification signature (_conv.qual_) that is the
423 union of the cv-qualification signatures of the operand
425 if (same_type_ignoring_top_level_qualifiers_p (pointee1, pointee2))
426 result_type = pointee1;
427 else if ((TREE_CODE (pointee1) == POINTER_TYPE
428 && TREE_CODE (pointee2) == POINTER_TYPE)
429 || (TYPE_PTR_TO_MEMBER_P (pointee1)
430 && TYPE_PTR_TO_MEMBER_P (pointee2)))
431 result_type = composite_pointer_type_r (pointee1, pointee2, location);
434 pedwarn ("%s between distinct pointer types %qT and %qT "
437 result_type = void_type_node;
439 result_type = cp_build_qualified_type (result_type,
440 (cp_type_quals (pointee1)
441 | cp_type_quals (pointee2)));
442 /* If the original types were pointers to members, so is the
444 if (TYPE_PTR_TO_MEMBER_P (t1))
446 if (!same_type_p (TYPE_PTRMEM_CLASS_TYPE (t1),
447 TYPE_PTRMEM_CLASS_TYPE (t2)))
448 pedwarn ("%s between distinct pointer types %qT and %qT "
451 result_type = build_ptrmem_type (TYPE_PTRMEM_CLASS_TYPE (t1),
455 result_type = build_pointer_type (result_type);
457 /* Merge the attributes. */
458 attributes = (*targetm.merge_type_attributes) (t1, t2);
459 return build_type_attribute_variant (result_type, attributes);
462 /* Return the composite pointer type (see [expr.rel]) for T1 and T2.
463 ARG1 and ARG2 are the values with those types. The LOCATION is a
464 string describing the current location, in case an error occurs.
466 This routine also implements the computation of a common type for
467 pointers-to-members as per [expr.eq]. */
470 composite_pointer_type (tree t1, tree t2, tree arg1, tree arg2,
471 const char* location)
478 If one operand is a null pointer constant, the composite pointer
479 type is the type of the other operand. */
480 if (null_ptr_cst_p (arg1))
482 if (null_ptr_cst_p (arg2))
489 If one of the operands has type "pointer to cv1 void*", then
490 the other has type "pointer to cv2T", and the composite pointer
491 type is "pointer to cv12 void", where cv12 is the union of cv1
494 If either type is a pointer to void, make sure it is T1. */
495 if (TREE_CODE (t2) == POINTER_TYPE && VOID_TYPE_P (TREE_TYPE (t2)))
503 /* Now, if T1 is a pointer to void, merge the qualifiers. */
504 if (TREE_CODE (t1) == POINTER_TYPE && VOID_TYPE_P (TREE_TYPE (t1)))
509 if (pedantic && TYPE_PTRFN_P (t2))
510 pedwarn ("ISO C++ forbids %s between pointer of type %<void *%> "
511 "and pointer-to-function", location);
513 = cp_build_qualified_type (void_type_node,
514 (cp_type_quals (TREE_TYPE (t1))
515 | cp_type_quals (TREE_TYPE (t2))));
516 result_type = build_pointer_type (result_type);
517 /* Merge the attributes. */
518 attributes = (*targetm.merge_type_attributes) (t1, t2);
519 return build_type_attribute_variant (result_type, attributes);
522 if (c_dialect_objc () && TREE_CODE (t1) == POINTER_TYPE
523 && TREE_CODE (t2) == POINTER_TYPE)
525 if (objc_compare_types (t1, t2, -3, NULL_TREE))
529 /* [expr.eq] permits the application of a pointer conversion to
530 bring the pointers to a common type. */
531 if (TREE_CODE (t1) == POINTER_TYPE && TREE_CODE (t2) == POINTER_TYPE
532 && CLASS_TYPE_P (TREE_TYPE (t1))
533 && CLASS_TYPE_P (TREE_TYPE (t2))
534 && !same_type_ignoring_top_level_qualifiers_p (TREE_TYPE (t1),
537 class1 = TREE_TYPE (t1);
538 class2 = TREE_TYPE (t2);
540 if (DERIVED_FROM_P (class1, class2))
541 t2 = (build_pointer_type
542 (cp_build_qualified_type (class1, TYPE_QUALS (class2))));
543 else if (DERIVED_FROM_P (class2, class1))
544 t1 = (build_pointer_type
545 (cp_build_qualified_type (class2, TYPE_QUALS (class1))));
548 error ("%s between distinct pointer types %qT and %qT "
549 "lacks a cast", location, t1, t2);
550 return error_mark_node;
553 /* [expr.eq] permits the application of a pointer-to-member
554 conversion to change the class type of one of the types. */
555 else if (TYPE_PTR_TO_MEMBER_P (t1)
556 && !same_type_p (TYPE_PTRMEM_CLASS_TYPE (t1),
557 TYPE_PTRMEM_CLASS_TYPE (t2)))
559 class1 = TYPE_PTRMEM_CLASS_TYPE (t1);
560 class2 = TYPE_PTRMEM_CLASS_TYPE (t2);
562 if (DERIVED_FROM_P (class1, class2))
563 t1 = build_ptrmem_type (class2, TYPE_PTRMEM_POINTED_TO_TYPE (t1));
564 else if (DERIVED_FROM_P (class2, class1))
565 t2 = build_ptrmem_type (class1, TYPE_PTRMEM_POINTED_TO_TYPE (t2));
568 error ("%s between distinct pointer-to-member types %qT and %qT "
569 "lacks a cast", location, t1, t2);
570 return error_mark_node;
574 return composite_pointer_type_r (t1, t2, location);
577 /* Return the merged type of two types.
578 We assume that comptypes has already been done and returned 1;
579 if that isn't so, this may crash.
581 This just combines attributes and default arguments; any other
582 differences would cause the two types to compare unalike. */
585 merge_types (tree t1, tree t2)
587 enum tree_code code1;
588 enum tree_code code2;
591 /* Save time if the two types are the same. */
594 if (original_type (t1) == original_type (t2))
597 /* If one type is nonsense, use the other. */
598 if (t1 == error_mark_node)
600 if (t2 == error_mark_node)
603 /* Merge the attributes. */
604 attributes = (*targetm.merge_type_attributes) (t1, t2);
606 if (TYPE_PTRMEMFUNC_P (t1))
607 t1 = TYPE_PTRMEMFUNC_FN_TYPE (t1);
608 if (TYPE_PTRMEMFUNC_P (t2))
609 t2 = TYPE_PTRMEMFUNC_FN_TYPE (t2);
611 code1 = TREE_CODE (t1);
612 code2 = TREE_CODE (t2);
618 /* For two pointers, do this recursively on the target type. */
620 tree target = merge_types (TREE_TYPE (t1), TREE_TYPE (t2));
621 int quals = cp_type_quals (t1);
623 if (code1 == POINTER_TYPE)
624 t1 = build_pointer_type (target);
626 t1 = build_reference_type (target);
627 t1 = build_type_attribute_variant (t1, attributes);
628 t1 = cp_build_qualified_type (t1, quals);
630 if (TREE_CODE (target) == METHOD_TYPE)
631 t1 = build_ptrmemfunc_type (t1);
640 quals = cp_type_quals (t1);
641 pointee = merge_types (TYPE_PTRMEM_POINTED_TO_TYPE (t1),
642 TYPE_PTRMEM_POINTED_TO_TYPE (t2));
643 t1 = build_ptrmem_type (TYPE_PTRMEM_CLASS_TYPE (t1),
645 t1 = cp_build_qualified_type (t1, quals);
651 tree elt = merge_types (TREE_TYPE (t1), TREE_TYPE (t2));
652 /* Save space: see if the result is identical to one of the args. */
653 if (elt == TREE_TYPE (t1) && TYPE_DOMAIN (t1))
654 return build_type_attribute_variant (t1, attributes);
655 if (elt == TREE_TYPE (t2) && TYPE_DOMAIN (t2))
656 return build_type_attribute_variant (t2, attributes);
657 /* Merge the element types, and have a size if either arg has one. */
658 t1 = build_cplus_array_type
659 (elt, TYPE_DOMAIN (TYPE_DOMAIN (t1) ? t1 : t2));
664 /* Function types: prefer the one that specified arg types.
665 If both do, merge the arg types. Also merge the return types. */
667 tree valtype = merge_types (TREE_TYPE (t1), TREE_TYPE (t2));
668 tree p1 = TYPE_ARG_TYPES (t1);
669 tree p2 = TYPE_ARG_TYPES (t2);
672 /* Save space: see if the result is identical to one of the args. */
673 if (valtype == TREE_TYPE (t1) && ! p2)
674 return cp_build_type_attribute_variant (t1, attributes);
675 if (valtype == TREE_TYPE (t2) && ! p1)
676 return cp_build_type_attribute_variant (t2, attributes);
678 /* Simple way if one arg fails to specify argument types. */
679 if (p1 == NULL_TREE || TREE_VALUE (p1) == void_type_node)
681 rval = build_function_type (valtype, p2);
682 if ((raises = TYPE_RAISES_EXCEPTIONS (t2)))
683 rval = build_exception_variant (rval, raises);
684 return cp_build_type_attribute_variant (rval, attributes);
686 raises = TYPE_RAISES_EXCEPTIONS (t1);
687 if (p2 == NULL_TREE || TREE_VALUE (p2) == void_type_node)
689 rval = build_function_type (valtype, p1);
691 rval = build_exception_variant (rval, raises);
692 return cp_build_type_attribute_variant (rval, attributes);
695 rval = build_function_type (valtype, commonparms (p1, p2));
696 t1 = build_exception_variant (rval, raises);
702 /* Get this value the long way, since TYPE_METHOD_BASETYPE
703 is just the main variant of this. */
704 tree basetype = TREE_TYPE (TREE_VALUE (TYPE_ARG_TYPES (t2)));
705 tree raises = TYPE_RAISES_EXCEPTIONS (t1);
708 /* If this was a member function type, get back to the
709 original type of type member function (i.e., without
710 the class instance variable up front. */
711 t1 = build_function_type (TREE_TYPE (t1),
712 TREE_CHAIN (TYPE_ARG_TYPES (t1)));
713 t2 = build_function_type (TREE_TYPE (t2),
714 TREE_CHAIN (TYPE_ARG_TYPES (t2)));
715 t3 = merge_types (t1, t2);
716 t3 = build_method_type_directly (basetype, TREE_TYPE (t3),
717 TYPE_ARG_TYPES (t3));
718 t1 = build_exception_variant (t3, raises);
723 /* There is no need to merge attributes into a TYPENAME_TYPE.
724 When the type is instantiated it will have whatever
725 attributes result from the instantiation. */
731 if (attribute_list_equal (TYPE_ATTRIBUTES (t1), attributes))
733 else if (attribute_list_equal (TYPE_ATTRIBUTES (t2), attributes))
736 return cp_build_type_attribute_variant (t1, attributes);
739 /* Return the common type of two types.
740 We assume that comptypes has already been done and returned 1;
741 if that isn't so, this may crash.
743 This is the type for the result of most arithmetic operations
744 if the operands have the given two types. */
747 common_type (tree t1, tree t2)
749 enum tree_code code1;
750 enum tree_code code2;
752 /* If one type is nonsense, bail. */
753 if (t1 == error_mark_node || t2 == error_mark_node)
754 return error_mark_node;
756 code1 = TREE_CODE (t1);
757 code2 = TREE_CODE (t2);
759 if ((ARITHMETIC_TYPE_P (t1) || code1 == ENUMERAL_TYPE
760 || code1 == COMPLEX_TYPE || code1 == VECTOR_TYPE)
761 && (ARITHMETIC_TYPE_P (t2) || code2 == ENUMERAL_TYPE
762 || code2 == COMPLEX_TYPE || code2 == VECTOR_TYPE))
763 return type_after_usual_arithmetic_conversions (t1, t2);
765 else if ((TYPE_PTR_P (t1) && TYPE_PTR_P (t2))
766 || (TYPE_PTRMEM_P (t1) && TYPE_PTRMEM_P (t2))
767 || (TYPE_PTRMEMFUNC_P (t1) && TYPE_PTRMEMFUNC_P (t2)))
768 return composite_pointer_type (t1, t2, error_mark_node, error_mark_node,
774 /* Compare two exception specifier types for exactness or subsetness, if
775 allowed. Returns false for mismatch, true for match (same, or
778 [except.spec] "If a class X ... objects of class X or any class publicly
779 and unambiguously derived from X. Similarly, if a pointer type Y * ...
780 exceptions of type Y * or that are pointers to any type publicly and
781 unambiguously derived from Y. Otherwise a function only allows exceptions
782 that have the same type ..."
783 This does not mention cv qualifiers and is different to what throw
784 [except.throw] and catch [except.catch] will do. They will ignore the
785 top level cv qualifiers, and allow qualifiers in the pointer to class
788 We implement the letter of the standard. */
791 comp_except_types (tree a, tree b, bool exact)
793 if (same_type_p (a, b))
797 if (cp_type_quals (a) || cp_type_quals (b))
800 if (TREE_CODE (a) == POINTER_TYPE
801 && TREE_CODE (b) == POINTER_TYPE)
805 if (cp_type_quals (a) || cp_type_quals (b))
809 if (TREE_CODE (a) != RECORD_TYPE
810 || TREE_CODE (b) != RECORD_TYPE)
813 if (PUBLICLY_UNIQUELY_DERIVED_P (a, b))
819 /* Return true if TYPE1 and TYPE2 are equivalent exception specifiers.
820 If EXACT is false, T2 can be stricter than T1 (according to 15.4/7),
821 otherwise it must be exact. Exception lists are unordered, but
822 we've already filtered out duplicates. Most lists will be in order,
823 we should try to make use of that. */
826 comp_except_specs (tree t1, tree t2, bool exact)
835 if (t1 == NULL_TREE) /* T1 is ... */
836 return t2 == NULL_TREE || !exact;
837 if (!TREE_VALUE (t1)) /* t1 is EMPTY */
838 return t2 != NULL_TREE && !TREE_VALUE (t2);
839 if (t2 == NULL_TREE) /* T2 is ... */
841 if (TREE_VALUE (t1) && !TREE_VALUE (t2)) /* T2 is EMPTY, T1 is not */
844 /* Neither set is ... or EMPTY, make sure each part of T2 is in T1.
845 Count how many we find, to determine exactness. For exact matching and
846 ordered T1, T2, this is an O(n) operation, otherwise its worst case is
848 for (base = t1; t2 != NULL_TREE; t2 = TREE_CHAIN (t2))
850 for (probe = base; probe != NULL_TREE; probe = TREE_CHAIN (probe))
852 tree a = TREE_VALUE (probe);
853 tree b = TREE_VALUE (t2);
855 if (comp_except_types (a, b, exact))
857 if (probe == base && exact)
858 base = TREE_CHAIN (probe);
863 if (probe == NULL_TREE)
866 return !exact || base == NULL_TREE || length == list_length (t1);
869 /* Compare the array types T1 and T2. ALLOW_REDECLARATION is true if
870 [] can match [size]. */
873 comp_array_types (tree t1, tree t2, bool allow_redeclaration)
882 /* The type of the array elements must be the same. */
883 if (!same_type_p (TREE_TYPE (t1), TREE_TYPE (t2)))
886 d1 = TYPE_DOMAIN (t1);
887 d2 = TYPE_DOMAIN (t2);
892 /* If one of the arrays is dimensionless, and the other has a
893 dimension, they are of different types. However, it is valid to
901 declarations for an array object can specify
902 array types that differ by the presence or absence of a major
903 array bound (_dcl.array_). */
905 return allow_redeclaration;
907 /* Check that the dimensions are the same. */
909 if (!cp_tree_equal (TYPE_MIN_VALUE (d1), TYPE_MIN_VALUE (d2)))
911 max1 = TYPE_MAX_VALUE (d1);
912 max2 = TYPE_MAX_VALUE (d2);
913 if (processing_template_decl && !abi_version_at_least (2)
914 && !value_dependent_expression_p (max1)
915 && !value_dependent_expression_p (max2))
917 /* With abi-1 we do not fold non-dependent array bounds, (and
918 consequently mangle them incorrectly). We must therefore
919 fold them here, to verify the domains have the same
925 if (!cp_tree_equal (max1, max2))
931 /* Subroutine in comptypes. */
934 structural_comptypes (tree t1, tree t2, int strict)
939 /* Suppress errors caused by previously reported errors. */
940 if (t1 == error_mark_node || t2 == error_mark_node)
943 gcc_assert (TYPE_P (t1) && TYPE_P (t2));
945 /* TYPENAME_TYPEs should be resolved if the qualifying scope is the
946 current instantiation. */
947 if (TREE_CODE (t1) == TYPENAME_TYPE)
949 tree resolved = resolve_typename_type (t1, /*only_current_p=*/true);
951 if (resolved != error_mark_node)
955 if (TREE_CODE (t2) == TYPENAME_TYPE)
957 tree resolved = resolve_typename_type (t2, /*only_current_p=*/true);
959 if (resolved != error_mark_node)
963 if (TYPE_PTRMEMFUNC_P (t1))
964 t1 = TYPE_PTRMEMFUNC_FN_TYPE (t1);
965 if (TYPE_PTRMEMFUNC_P (t2))
966 t2 = TYPE_PTRMEMFUNC_FN_TYPE (t2);
968 /* Different classes of types can't be compatible. */
969 if (TREE_CODE (t1) != TREE_CODE (t2))
972 /* Qualifiers must match. For array types, we will check when we
973 recur on the array element types. */
974 if (TREE_CODE (t1) != ARRAY_TYPE
975 && TYPE_QUALS (t1) != TYPE_QUALS (t2))
977 if (TYPE_FOR_JAVA (t1) != TYPE_FOR_JAVA (t2))
980 /* Allow for two different type nodes which have essentially the same
981 definition. Note that we already checked for equality of the type
982 qualifiers (just above). */
984 if (TREE_CODE (t1) != ARRAY_TYPE
985 && TYPE_MAIN_VARIANT (t1) == TYPE_MAIN_VARIANT (t2))
988 /* Compare the types. Break out if they could be the same. */
989 switch (TREE_CODE (t1))
991 case TEMPLATE_TEMPLATE_PARM:
992 case BOUND_TEMPLATE_TEMPLATE_PARM:
993 if (TEMPLATE_TYPE_IDX (t1) != TEMPLATE_TYPE_IDX (t2)
994 || TEMPLATE_TYPE_LEVEL (t1) != TEMPLATE_TYPE_LEVEL (t2))
996 if (!comp_template_parms
997 (DECL_TEMPLATE_PARMS (TEMPLATE_TEMPLATE_PARM_TEMPLATE_DECL (t1)),
998 DECL_TEMPLATE_PARMS (TEMPLATE_TEMPLATE_PARM_TEMPLATE_DECL (t2))))
1000 if (TREE_CODE (t1) == TEMPLATE_TEMPLATE_PARM)
1002 /* Don't check inheritance. */
1003 strict = COMPARE_STRICT;
1008 if (TYPE_TEMPLATE_INFO (t1) && TYPE_TEMPLATE_INFO (t2)
1009 && (TYPE_TI_TEMPLATE (t1) == TYPE_TI_TEMPLATE (t2)
1010 || TREE_CODE (t1) == BOUND_TEMPLATE_TEMPLATE_PARM)
1011 && comp_template_args (TYPE_TI_ARGS (t1), TYPE_TI_ARGS (t2)))
1014 if ((strict & COMPARE_BASE) && DERIVED_FROM_P (t1, t2))
1016 else if ((strict & COMPARE_DERIVED) && DERIVED_FROM_P (t2, t1))
1022 if (!comptypes (TYPE_OFFSET_BASETYPE (t1), TYPE_OFFSET_BASETYPE (t2),
1023 strict & ~COMPARE_REDECLARATION))
1025 if (!same_type_p (TREE_TYPE (t1), TREE_TYPE (t2)))
1030 case REFERENCE_TYPE:
1031 if (TYPE_MODE (t1) != TYPE_MODE (t2)
1032 || TYPE_REF_CAN_ALIAS_ALL (t1) != TYPE_REF_CAN_ALIAS_ALL (t2)
1033 || !same_type_p (TREE_TYPE (t1), TREE_TYPE (t2)))
1039 if (!same_type_p (TREE_TYPE (t1), TREE_TYPE (t2)))
1041 if (!compparms (TYPE_ARG_TYPES (t1), TYPE_ARG_TYPES (t2)))
1046 /* Target types must match incl. qualifiers. */
1047 if (!comp_array_types (t1, t2, !!(strict & COMPARE_REDECLARATION)))
1051 case TEMPLATE_TYPE_PARM:
1052 if (TEMPLATE_TYPE_IDX (t1) != TEMPLATE_TYPE_IDX (t2)
1053 || TEMPLATE_TYPE_LEVEL (t1) != TEMPLATE_TYPE_LEVEL (t2))
1058 if (!cp_tree_equal (TYPENAME_TYPE_FULLNAME (t1),
1059 TYPENAME_TYPE_FULLNAME (t2)))
1061 if (!same_type_p (TYPE_CONTEXT (t1), TYPE_CONTEXT (t2)))
1065 case UNBOUND_CLASS_TEMPLATE:
1066 if (!cp_tree_equal (TYPE_IDENTIFIER (t1), TYPE_IDENTIFIER (t2)))
1068 if (!same_type_p (TYPE_CONTEXT (t1), TYPE_CONTEXT (t2)))
1073 if (!same_type_p (TREE_TYPE (t1), TREE_TYPE (t2)))
1078 if (TYPE_VECTOR_SUBPARTS (t1) != TYPE_VECTOR_SUBPARTS (t2)
1079 || !same_type_p (TREE_TYPE (t1), TREE_TYPE (t2)))
1087 /* If we get here, we know that from a target independent POV the
1088 types are the same. Make sure the target attributes are also
1090 return targetm.comp_type_attributes (t1, t2);
1093 /* Return true if T1 and T2 are related as allowed by STRICT. STRICT
1094 is a bitwise-or of the COMPARE_* flags. */
1097 comptypes (tree t1, tree t2, int strict)
1099 if (strict == COMPARE_STRICT)
1106 if (t1 == error_mark_node || t2 == error_mark_node)
1109 if (TYPE_STRUCTURAL_EQUALITY_P (t1) || TYPE_STRUCTURAL_EQUALITY_P (t2))
1110 /* At least one of the types requires structural equality, so
1111 perform a deep check. */
1112 return structural_comptypes (t1, t2, strict);
1114 if (VERIFY_CANONICAL_TYPES)
1116 result = structural_comptypes (t1, t2, strict);
1118 if (result && TYPE_CANONICAL (t1) != TYPE_CANONICAL (t2))
1120 /* The two types are structurally equivalent, but their
1121 canonical types were different. This is a failure of the
1122 canonical type propagation code.*/
1124 "canonical types differ for identical types %T and %T",
1129 else if (!result && TYPE_CANONICAL (t1) == TYPE_CANONICAL (t2))
1131 /* Two types are structurally different, but the canonical
1132 types are the same. This means we were over-eager in
1133 assigning canonical types. */
1135 "same canonical type node for different types %T and %T",
1144 return TYPE_CANONICAL (t1) == TYPE_CANONICAL (t2);
1146 else if (strict == COMPARE_STRUCTURAL)
1147 return structural_comptypes (t1, t2, COMPARE_STRICT);
1149 return structural_comptypes (t1, t2, strict);
1152 /* Returns 1 if TYPE1 is at least as qualified as TYPE2. */
1155 at_least_as_qualified_p (tree type1, tree type2)
1157 int q1 = cp_type_quals (type1);
1158 int q2 = cp_type_quals (type2);
1160 /* All qualifiers for TYPE2 must also appear in TYPE1. */
1161 return (q1 & q2) == q2;
1164 /* Returns 1 if TYPE1 is more cv-qualified than TYPE2, -1 if TYPE2 is
1165 more cv-qualified that TYPE1, and 0 otherwise. */
1168 comp_cv_qualification (tree type1, tree type2)
1170 int q1 = cp_type_quals (type1);
1171 int q2 = cp_type_quals (type2);
1176 if ((q1 & q2) == q2)
1178 else if ((q1 & q2) == q1)
1184 /* Returns 1 if the cv-qualification signature of TYPE1 is a proper
1185 subset of the cv-qualification signature of TYPE2, and the types
1186 are similar. Returns -1 if the other way 'round, and 0 otherwise. */
1189 comp_cv_qual_signature (tree type1, tree type2)
1191 if (comp_ptr_ttypes_real (type2, type1, -1))
1193 else if (comp_ptr_ttypes_real (type1, type2, -1))
1199 /* If two types share a common base type, return that basetype.
1200 If there is not a unique most-derived base type, this function
1201 returns ERROR_MARK_NODE. */
1204 common_base_type (tree tt1, tree tt2)
1206 tree best = NULL_TREE;
1209 /* If one is a baseclass of another, that's good enough. */
1210 if (UNIQUELY_DERIVED_FROM_P (tt1, tt2))
1212 if (UNIQUELY_DERIVED_FROM_P (tt2, tt1))
1215 /* Otherwise, try to find a unique baseclass of TT1
1216 that is shared by TT2, and follow that down. */
1217 for (i = BINFO_N_BASE_BINFOS (TYPE_BINFO (tt1))-1; i >= 0; i--)
1219 tree basetype = BINFO_TYPE (BINFO_BASE_BINFO (TYPE_BINFO (tt1), i));
1220 tree trial = common_base_type (basetype, tt2);
1224 if (trial == error_mark_node)
1226 if (best == NULL_TREE)
1228 else if (best != trial)
1229 return error_mark_node;
1234 for (i = BINFO_N_BASE_BINFOS (TYPE_BINFO (tt2))-1; i >= 0; i--)
1236 tree basetype = BINFO_TYPE (BINFO_BASE_BINFO (TYPE_BINFO (tt2), i));
1237 tree trial = common_base_type (tt1, basetype);
1241 if (trial == error_mark_node)
1243 if (best == NULL_TREE)
1245 else if (best != trial)
1246 return error_mark_node;
1252 /* Subroutines of `comptypes'. */
1254 /* Return true if two parameter type lists PARMS1 and PARMS2 are
1255 equivalent in the sense that functions with those parameter types
1256 can have equivalent types. The two lists must be equivalent,
1257 element by element. */
1260 compparms (tree parms1, tree parms2)
1264 /* An unspecified parmlist matches any specified parmlist
1265 whose argument types don't need default promotions. */
1267 for (t1 = parms1, t2 = parms2;
1269 t1 = TREE_CHAIN (t1), t2 = TREE_CHAIN (t2))
1271 /* If one parmlist is shorter than the other,
1272 they fail to match. */
1275 if (!same_type_p (TREE_VALUE (t1), TREE_VALUE (t2)))
1282 /* Process a sizeof or alignof expression where the operand is a
1286 cxx_sizeof_or_alignof_type (tree type, enum tree_code op, bool complain)
1291 gcc_assert (op == SIZEOF_EXPR || op == ALIGNOF_EXPR);
1292 if (type == error_mark_node)
1293 return error_mark_node;
1295 type = non_reference (type);
1296 if (TREE_CODE (type) == METHOD_TYPE)
1298 if (complain && (pedantic || warn_pointer_arith))
1299 pedwarn ("invalid application of %qs to a member function",
1300 operator_name_info[(int) op].name);
1301 value = size_one_node;
1304 dependent_p = dependent_type_p (type);
1306 complete_type (type);
1308 /* VLA types will have a non-constant size. In the body of an
1309 uninstantiated template, we don't need to try to compute the
1310 value, because the sizeof expression is not an integral
1311 constant expression in that case. And, if we do try to
1312 compute the value, we'll likely end up with SAVE_EXPRs, which
1313 the template substitution machinery does not expect to see. */
1314 || (processing_template_decl
1315 && COMPLETE_TYPE_P (type)
1316 && TREE_CODE (TYPE_SIZE (type)) != INTEGER_CST))
1318 value = build_min (op, size_type_node, type);
1319 TREE_READONLY (value) = 1;
1323 return c_sizeof_or_alignof_type (complete_type (type),
1328 /* Process a sizeof expression where the operand is an expression. */
1331 cxx_sizeof_expr (tree e)
1333 if (e == error_mark_node)
1334 return error_mark_node;
1336 if (processing_template_decl)
1338 e = build_min (SIZEOF_EXPR, size_type_node, e);
1339 TREE_SIDE_EFFECTS (e) = 0;
1340 TREE_READONLY (e) = 1;
1345 if (TREE_CODE (e) == COMPONENT_REF
1346 && TREE_CODE (TREE_OPERAND (e, 1)) == FIELD_DECL
1347 && DECL_C_BIT_FIELD (TREE_OPERAND (e, 1)))
1349 error ("invalid application of %<sizeof%> to a bit-field");
1352 else if (is_overloaded_fn (e))
1354 pedwarn ("ISO C++ forbids applying %<sizeof%> to an expression of "
1358 else if (type_unknown_p (e))
1360 cxx_incomplete_type_error (e, TREE_TYPE (e));
1366 return cxx_sizeof_or_alignof_type (e, SIZEOF_EXPR, true);
1369 /* Implement the __alignof keyword: Return the minimum required
1370 alignment of E, measured in bytes. For VAR_DECL's and
1371 FIELD_DECL's return DECL_ALIGN (which can be set from an
1372 "aligned" __attribute__ specification). */
1375 cxx_alignof_expr (tree e)
1379 if (e == error_mark_node)
1380 return error_mark_node;
1382 if (processing_template_decl)
1384 e = build_min (ALIGNOF_EXPR, size_type_node, e);
1385 TREE_SIDE_EFFECTS (e) = 0;
1386 TREE_READONLY (e) = 1;
1391 if (TREE_CODE (e) == VAR_DECL)
1392 t = size_int (DECL_ALIGN_UNIT (e));
1393 else if (TREE_CODE (e) == COMPONENT_REF
1394 && TREE_CODE (TREE_OPERAND (e, 1)) == FIELD_DECL
1395 && DECL_C_BIT_FIELD (TREE_OPERAND (e, 1)))
1397 error ("invalid application of %<__alignof%> to a bit-field");
1400 else if (TREE_CODE (e) == COMPONENT_REF
1401 && TREE_CODE (TREE_OPERAND (e, 1)) == FIELD_DECL)
1402 t = size_int (DECL_ALIGN_UNIT (TREE_OPERAND (e, 1)));
1403 else if (is_overloaded_fn (e))
1405 pedwarn ("ISO C++ forbids applying %<__alignof%> to an expression of "
1409 else if (type_unknown_p (e))
1411 cxx_incomplete_type_error (e, TREE_TYPE (e));
1415 return cxx_sizeof_or_alignof_type (TREE_TYPE (e), ALIGNOF_EXPR, true);
1417 return fold_convert (size_type_node, t);
1420 /* Process a sizeof or alignof expression E with code OP where the operand
1421 is an expression. */
1424 cxx_sizeof_or_alignof_expr (tree e, enum tree_code op)
1426 if (op == SIZEOF_EXPR)
1427 return cxx_sizeof_expr (e);
1429 return cxx_alignof_expr (e);
1432 /* EXPR is being used in a context that is not a function call.
1437 The expression can be used only as the left-hand operand of a
1438 member function call.
1440 [expr.mptr.operator]
1442 If the result of .* or ->* is a function, then that result can be
1443 used only as the operand for the function call operator ().
1445 by issuing an error message if appropriate. Returns true iff EXPR
1446 violates these rules. */
1449 invalid_nonstatic_memfn_p (tree expr)
1451 if (TREE_CODE (TREE_TYPE (expr)) == METHOD_TYPE)
1453 error ("invalid use of non-static member function");
1459 /* If EXP is a reference to a bitfield, and the type of EXP does not
1460 match the declared type of the bitfield, return the declared type
1461 of the bitfield. Otherwise, return NULL_TREE. */
1464 is_bitfield_expr_with_lowered_type (tree exp)
1468 if (TREE_CODE (exp) == COND_EXPR)
1470 if (!is_bitfield_expr_with_lowered_type (TREE_OPERAND (exp, 1)))
1472 return is_bitfield_expr_with_lowered_type (TREE_OPERAND (exp, 2));
1474 if (TREE_CODE (exp) != COMPONENT_REF)
1476 field = TREE_OPERAND (exp, 1);
1477 if (TREE_CODE (field) != FIELD_DECL || !DECL_C_BIT_FIELD (field))
1479 if (same_type_ignoring_top_level_qualifiers_p
1480 (TREE_TYPE (exp), DECL_BIT_FIELD_TYPE (field)))
1482 return DECL_BIT_FIELD_TYPE (field);
1485 /* Perform the conversions in [expr] that apply when an lvalue appears
1486 in an rvalue context: the lvalue-to-rvalue, array-to-pointer, and
1487 function-to-pointer conversions. In addition, manifest constants
1488 are replaced by their values, and bitfield references are converted
1489 to their declared types.
1491 Although the returned value is being used as an rvalue, this
1492 function does not wrap the returned expression in a
1493 NON_LVALUE_EXPR; the caller is expected to be mindful of the fact
1494 that the return value is no longer an lvalue. */
1497 decay_conversion (tree exp)
1500 enum tree_code code;
1502 type = TREE_TYPE (exp);
1503 if (type == error_mark_node)
1504 return error_mark_node;
1506 if (type_unknown_p (exp))
1508 cxx_incomplete_type_error (exp, TREE_TYPE (exp));
1509 return error_mark_node;
1512 exp = decl_constant_value (exp);
1513 if (error_operand_p (exp))
1514 return error_mark_node;
1516 /* build_c_cast puts on a NOP_EXPR to make the result not an lvalue.
1517 Leave such NOP_EXPRs, since RHS is being used in non-lvalue context. */
1518 code = TREE_CODE (type);
1519 if (code == VOID_TYPE)
1521 error ("void value not ignored as it ought to be");
1522 return error_mark_node;
1524 if (invalid_nonstatic_memfn_p (exp))
1525 return error_mark_node;
1526 if (code == FUNCTION_TYPE || is_overloaded_fn (exp))
1527 return build_unary_op (ADDR_EXPR, exp, 0);
1528 if (code == ARRAY_TYPE)
1533 if (TREE_CODE (exp) == INDIRECT_REF)
1534 return build_nop (build_pointer_type (TREE_TYPE (type)),
1535 TREE_OPERAND (exp, 0));
1537 if (TREE_CODE (exp) == COMPOUND_EXPR)
1539 tree op1 = decay_conversion (TREE_OPERAND (exp, 1));
1540 return build2 (COMPOUND_EXPR, TREE_TYPE (op1),
1541 TREE_OPERAND (exp, 0), op1);
1545 && ! (TREE_CODE (exp) == CONSTRUCTOR && TREE_STATIC (exp)))
1547 error ("invalid use of non-lvalue array");
1548 return error_mark_node;
1551 ptrtype = build_pointer_type (TREE_TYPE (type));
1553 if (TREE_CODE (exp) == VAR_DECL)
1555 if (!cxx_mark_addressable (exp))
1556 return error_mark_node;
1557 adr = build_nop (ptrtype, build_address (exp));
1560 /* This way is better for a COMPONENT_REF since it can
1561 simplify the offset for a component. */
1562 adr = build_unary_op (ADDR_EXPR, exp, 1);
1563 return cp_convert (ptrtype, adr);
1566 /* If a bitfield is used in a context where integral promotion
1567 applies, then the caller is expected to have used
1568 default_conversion. That function promotes bitfields correctly
1569 before calling this function. At this point, if we have a
1570 bitfield referenced, we may assume that is not subject to
1571 promotion, and that, therefore, the type of the resulting rvalue
1572 is the declared type of the bitfield. */
1573 exp = convert_bitfield_to_declared_type (exp);
1575 /* We do not call rvalue() here because we do not want to wrap EXP
1576 in a NON_LVALUE_EXPR. */
1580 Non-class rvalues always have cv-unqualified types. */
1581 type = TREE_TYPE (exp);
1582 if (!CLASS_TYPE_P (type) && cp_type_quals (type))
1583 exp = build_nop (TYPE_MAIN_VARIANT (type), exp);
1588 /* Perform prepatory conversions, as part of the "usual arithmetic
1589 conversions". In particular, as per [expr]:
1591 Whenever an lvalue expression appears as an operand of an
1592 operator that expects the rvalue for that operand, the
1593 lvalue-to-rvalue, array-to-pointer, or function-to-pointer
1594 standard conversions are applied to convert the expression to an
1597 In addition, we perform integral promotions here, as those are
1598 applied to both operands to a binary operator before determining
1599 what additional conversions should apply. */
1602 default_conversion (tree exp)
1604 /* Perform the integral promotions first so that bitfield
1605 expressions (which may promote to "int", even if the bitfield is
1606 declared "unsigned") are promoted correctly. */
1607 if (INTEGRAL_OR_ENUMERATION_TYPE_P (TREE_TYPE (exp)))
1608 exp = perform_integral_promotions (exp);
1609 /* Perform the other conversions. */
1610 exp = decay_conversion (exp);
1615 /* EXPR is an expression with an integral or enumeration type.
1616 Perform the integral promotions in [conv.prom], and return the
1620 perform_integral_promotions (tree expr)
1627 If the bitfield has an enumerated type, it is treated as any
1628 other value of that type for promotion purposes. */
1629 type = is_bitfield_expr_with_lowered_type (expr);
1630 if (!type || TREE_CODE (type) != ENUMERAL_TYPE)
1631 type = TREE_TYPE (expr);
1632 gcc_assert (INTEGRAL_OR_ENUMERATION_TYPE_P (type));
1633 promoted_type = type_promotes_to (type);
1634 if (type != promoted_type)
1635 expr = cp_convert (promoted_type, expr);
1639 /* Take the address of an inline function without setting TREE_ADDRESSABLE
1643 inline_conversion (tree exp)
1645 if (TREE_CODE (exp) == FUNCTION_DECL)
1646 exp = build1 (ADDR_EXPR, build_pointer_type (TREE_TYPE (exp)), exp);
1651 /* Returns nonzero iff exp is a STRING_CST or the result of applying
1652 decay_conversion to one. */
1655 string_conv_p (tree totype, tree exp, int warn)
1659 if (TREE_CODE (totype) != POINTER_TYPE)
1662 t = TREE_TYPE (totype);
1663 if (!same_type_p (t, char_type_node)
1664 && !same_type_p (t, wchar_type_node))
1667 if (TREE_CODE (exp) == STRING_CST)
1669 /* Make sure that we don't try to convert between char and wchar_t. */
1670 if (!same_type_p (TYPE_MAIN_VARIANT (TREE_TYPE (TREE_TYPE (exp))), t))
1675 /* Is this a string constant which has decayed to 'const char *'? */
1676 t = build_pointer_type (build_qualified_type (t, TYPE_QUAL_CONST));
1677 if (!same_type_p (TREE_TYPE (exp), t))
1680 if (TREE_CODE (exp) != ADDR_EXPR
1681 || TREE_CODE (TREE_OPERAND (exp, 0)) != STRING_CST)
1685 /* This warning is not very useful, as it complains about printf. */
1687 warning (OPT_Wwrite_strings,
1688 "deprecated conversion from string constant to %qT",
1694 /* Given a COND_EXPR, MIN_EXPR, or MAX_EXPR in T, return it in a form that we
1695 can, for example, use as an lvalue. This code used to be in
1696 unary_complex_lvalue, but we needed it to deal with `a = (d == c) ? b : c'
1697 expressions, where we're dealing with aggregates. But now it's again only
1698 called from unary_complex_lvalue. The case (in particular) that led to
1699 this was with CODE == ADDR_EXPR, since it's not an lvalue when we'd
1703 rationalize_conditional_expr (enum tree_code code, tree t)
1705 /* For MIN_EXPR or MAX_EXPR, fold-const.c has arranged things so that
1706 the first operand is always the one to be used if both operands
1707 are equal, so we know what conditional expression this used to be. */
1708 if (TREE_CODE (t) == MIN_EXPR || TREE_CODE (t) == MAX_EXPR)
1710 tree op0 = TREE_OPERAND (t, 0);
1711 tree op1 = TREE_OPERAND (t, 1);
1713 /* The following code is incorrect if either operand side-effects. */
1714 gcc_assert (!TREE_SIDE_EFFECTS (op0)
1715 && !TREE_SIDE_EFFECTS (op1));
1717 build_conditional_expr (build_x_binary_op ((TREE_CODE (t) == MIN_EXPR
1718 ? LE_EXPR : GE_EXPR),
1719 op0, TREE_CODE (op0),
1720 op1, TREE_CODE (op1),
1721 /*overloaded_p=*/NULL),
1722 build_unary_op (code, op0, 0),
1723 build_unary_op (code, op1, 0));
1727 build_conditional_expr (TREE_OPERAND (t, 0),
1728 build_unary_op (code, TREE_OPERAND (t, 1), 0),
1729 build_unary_op (code, TREE_OPERAND (t, 2), 0));
1732 /* Given the TYPE of an anonymous union field inside T, return the
1733 FIELD_DECL for the field. If not found return NULL_TREE. Because
1734 anonymous unions can nest, we must also search all anonymous unions
1735 that are directly reachable. */
1738 lookup_anon_field (tree t, tree type)
1742 for (field = TYPE_FIELDS (t); field; field = TREE_CHAIN (field))
1744 if (TREE_STATIC (field))
1746 if (TREE_CODE (field) != FIELD_DECL || DECL_ARTIFICIAL (field))
1749 /* If we find it directly, return the field. */
1750 if (DECL_NAME (field) == NULL_TREE
1751 && type == TYPE_MAIN_VARIANT (TREE_TYPE (field)))
1756 /* Otherwise, it could be nested, search harder. */
1757 if (DECL_NAME (field) == NULL_TREE
1758 && ANON_AGGR_TYPE_P (TREE_TYPE (field)))
1760 tree subfield = lookup_anon_field (TREE_TYPE (field), type);
1768 /* Build an expression representing OBJECT.MEMBER. OBJECT is an
1769 expression; MEMBER is a DECL or baselink. If ACCESS_PATH is
1770 non-NULL, it indicates the path to the base used to name MEMBER.
1771 If PRESERVE_REFERENCE is true, the expression returned will have
1772 REFERENCE_TYPE if the MEMBER does. Otherwise, the expression
1773 returned will have the type referred to by the reference.
1775 This function does not perform access control; that is either done
1776 earlier by the parser when the name of MEMBER is resolved to MEMBER
1777 itself, or later when overload resolution selects one of the
1778 functions indicated by MEMBER. */
1781 build_class_member_access_expr (tree object, tree member,
1782 tree access_path, bool preserve_reference)
1786 tree result = NULL_TREE;
1788 if (error_operand_p (object) || error_operand_p (member))
1789 return error_mark_node;
1791 gcc_assert (DECL_P (member) || BASELINK_P (member));
1795 The type of the first expression shall be "class object" (of a
1797 object_type = TREE_TYPE (object);
1798 if (!currently_open_class (object_type)
1799 && !complete_type_or_else (object_type, object))
1800 return error_mark_node;
1801 if (!CLASS_TYPE_P (object_type))
1803 error ("request for member %qD in %qE, which is of non-class type %qT",
1804 member, object, object_type);
1805 return error_mark_node;
1808 /* The standard does not seem to actually say that MEMBER must be a
1809 member of OBJECT_TYPE. However, that is clearly what is
1811 if (DECL_P (member))
1813 member_scope = DECL_CLASS_CONTEXT (member);
1815 if (TREE_DEPRECATED (member))
1816 warn_deprecated_use (member);
1819 member_scope = BINFO_TYPE (BASELINK_BINFO (member));
1820 /* If MEMBER is from an anonymous aggregate, MEMBER_SCOPE will
1821 presently be the anonymous union. Go outwards until we find a
1822 type related to OBJECT_TYPE. */
1823 while (ANON_AGGR_TYPE_P (member_scope)
1824 && !same_type_ignoring_top_level_qualifiers_p (member_scope,
1826 member_scope = TYPE_CONTEXT (member_scope);
1827 if (!member_scope || !DERIVED_FROM_P (member_scope, object_type))
1829 if (TREE_CODE (member) == FIELD_DECL)
1830 error ("invalid use of nonstatic data member %qE", member);
1832 error ("%qD is not a member of %qT", member, object_type);
1833 return error_mark_node;
1836 /* Transform `(a, b).x' into `(*(a, &b)).x', `(a ? b : c).x' into
1837 `(*(a ? &b : &c)).x', and so on. A COND_EXPR is only an lvalue
1838 in the frontend; only _DECLs and _REFs are lvalues in the backend. */
1840 tree temp = unary_complex_lvalue (ADDR_EXPR, object);
1842 object = build_indirect_ref (temp, NULL);
1845 /* In [expr.ref], there is an explicit list of the valid choices for
1846 MEMBER. We check for each of those cases here. */
1847 if (TREE_CODE (member) == VAR_DECL)
1849 /* A static data member. */
1851 /* If OBJECT has side-effects, they are supposed to occur. */
1852 if (TREE_SIDE_EFFECTS (object))
1853 result = build2 (COMPOUND_EXPR, TREE_TYPE (result), object, result);
1855 else if (TREE_CODE (member) == FIELD_DECL)
1857 /* A non-static data member. */
1862 null_object_p = (TREE_CODE (object) == INDIRECT_REF
1863 && integer_zerop (TREE_OPERAND (object, 0)));
1865 /* Convert OBJECT to the type of MEMBER. */
1866 if (!same_type_p (TYPE_MAIN_VARIANT (object_type),
1867 TYPE_MAIN_VARIANT (member_scope)))
1872 binfo = lookup_base (access_path ? access_path : object_type,
1873 member_scope, ba_unique, &kind);
1874 if (binfo == error_mark_node)
1875 return error_mark_node;
1877 /* It is invalid to try to get to a virtual base of a
1878 NULL object. The most common cause is invalid use of
1880 if (null_object_p && kind == bk_via_virtual)
1882 error ("invalid access to non-static data member %qD of "
1885 error ("(perhaps the %<offsetof%> macro was used incorrectly)");
1886 return error_mark_node;
1889 /* Convert to the base. */
1890 object = build_base_path (PLUS_EXPR, object, binfo,
1892 /* If we found the base successfully then we should be able
1893 to convert to it successfully. */
1894 gcc_assert (object != error_mark_node);
1897 /* Complain about other invalid uses of offsetof, even though they will
1898 give the right answer. Note that we complain whether or not they
1899 actually used the offsetof macro, since there's no way to know at this
1900 point. So we just give a warning, instead of a pedwarn. */
1901 /* Do not produce this warning for base class field references, because
1902 we know for a fact that didn't come from offsetof. This does occur
1903 in various testsuite cases where a null object is passed where a
1904 vtable access is required. */
1905 if (null_object_p && warn_invalid_offsetof
1906 && CLASSTYPE_NON_POD_P (object_type)
1907 && !DECL_FIELD_IS_BASE (member)
1908 && !skip_evaluation)
1910 warning (0, "invalid access to non-static data member %qD of NULL object",
1912 warning (0, "(perhaps the %<offsetof%> macro was used incorrectly)");
1915 /* If MEMBER is from an anonymous aggregate, we have converted
1916 OBJECT so that it refers to the class containing the
1917 anonymous union. Generate a reference to the anonymous union
1918 itself, and recur to find MEMBER. */
1919 if (ANON_AGGR_TYPE_P (DECL_CONTEXT (member))
1920 /* When this code is called from build_field_call, the
1921 object already has the type of the anonymous union.
1922 That is because the COMPONENT_REF was already
1923 constructed, and was then disassembled before calling
1924 build_field_call. After the function-call code is
1925 cleaned up, this waste can be eliminated. */
1926 && (!same_type_ignoring_top_level_qualifiers_p
1927 (TREE_TYPE (object), DECL_CONTEXT (member))))
1929 tree anonymous_union;
1931 anonymous_union = lookup_anon_field (TREE_TYPE (object),
1932 DECL_CONTEXT (member));
1933 object = build_class_member_access_expr (object,
1935 /*access_path=*/NULL_TREE,
1936 preserve_reference);
1939 /* Compute the type of the field, as described in [expr.ref]. */
1940 type_quals = TYPE_UNQUALIFIED;
1941 member_type = TREE_TYPE (member);
1942 if (TREE_CODE (member_type) != REFERENCE_TYPE)
1944 type_quals = (cp_type_quals (member_type)
1945 | cp_type_quals (object_type));
1947 /* A field is const (volatile) if the enclosing object, or the
1948 field itself, is const (volatile). But, a mutable field is
1949 not const, even within a const object. */
1950 if (DECL_MUTABLE_P (member))
1951 type_quals &= ~TYPE_QUAL_CONST;
1952 member_type = cp_build_qualified_type (member_type, type_quals);
1955 result = build3 (COMPONENT_REF, member_type, object, member,
1957 result = fold_if_not_in_template (result);
1959 /* Mark the expression const or volatile, as appropriate. Even
1960 though we've dealt with the type above, we still have to mark the
1961 expression itself. */
1962 if (type_quals & TYPE_QUAL_CONST)
1963 TREE_READONLY (result) = 1;
1964 if (type_quals & TYPE_QUAL_VOLATILE)
1965 TREE_THIS_VOLATILE (result) = 1;
1967 else if (BASELINK_P (member))
1969 /* The member is a (possibly overloaded) member function. */
1973 /* If the MEMBER is exactly one static member function, then we
1974 know the type of the expression. Otherwise, we must wait
1975 until overload resolution has been performed. */
1976 functions = BASELINK_FUNCTIONS (member);
1977 if (TREE_CODE (functions) == FUNCTION_DECL
1978 && DECL_STATIC_FUNCTION_P (functions))
1979 type = TREE_TYPE (functions);
1981 type = unknown_type_node;
1982 /* Note that we do not convert OBJECT to the BASELINK_BINFO
1983 base. That will happen when the function is called. */
1984 result = build3 (COMPONENT_REF, type, object, member, NULL_TREE);
1986 else if (TREE_CODE (member) == CONST_DECL)
1988 /* The member is an enumerator. */
1990 /* If OBJECT has side-effects, they are supposed to occur. */
1991 if (TREE_SIDE_EFFECTS (object))
1992 result = build2 (COMPOUND_EXPR, TREE_TYPE (result),
1997 error ("invalid use of %qD", member);
1998 return error_mark_node;
2001 if (!preserve_reference)
2004 If E2 is declared to have type "reference to T", then ... the
2005 type of E1.E2 is T. */
2006 result = convert_from_reference (result);
2011 /* Return the destructor denoted by OBJECT.SCOPE::~DTOR_NAME, or, if
2012 SCOPE is NULL, by OBJECT.~DTOR_NAME. */
2015 lookup_destructor (tree object, tree scope, tree dtor_name)
2017 tree object_type = TREE_TYPE (object);
2018 tree dtor_type = TREE_OPERAND (dtor_name, 0);
2021 if (scope && !check_dtor_name (scope, dtor_type))
2023 error ("qualified type %qT does not match destructor name ~%qT",
2025 return error_mark_node;
2027 if (!DERIVED_FROM_P (dtor_type, TYPE_MAIN_VARIANT (object_type)))
2029 error ("the type being destroyed is %qT, but the destructor refers to %qT",
2030 TYPE_MAIN_VARIANT (object_type), dtor_type);
2031 return error_mark_node;
2033 expr = lookup_member (dtor_type, complete_dtor_identifier,
2034 /*protect=*/1, /*want_type=*/false);
2035 expr = (adjust_result_of_qualified_name_lookup
2036 (expr, dtor_type, object_type));
2040 /* An expression of the form "A::template B" has been resolved to
2041 DECL. Issue a diagnostic if B is not a template or template
2045 check_template_keyword (tree decl)
2047 /* The standard says:
2051 If a name prefixed by the keyword template is not a member
2052 template, the program is ill-formed.
2054 DR 228 removed the restriction that the template be a member
2057 DR 96, if accepted would add the further restriction that explicit
2058 template arguments must be provided if the template keyword is
2059 used, but, as of 2005-10-16, that DR is still in "drafting". If
2060 this DR is accepted, then the semantic checks here can be
2061 simplified, as the entity named must in fact be a template
2062 specialization, rather than, as at present, a set of overloaded
2063 functions containing at least one template function. */
2064 if (TREE_CODE (decl) != TEMPLATE_DECL
2065 && TREE_CODE (decl) != TEMPLATE_ID_EXPR)
2067 if (!is_overloaded_fn (decl))
2068 pedwarn ("%qD is not a template", decl);
2073 if (BASELINK_P (fns))
2074 fns = BASELINK_FUNCTIONS (fns);
2077 tree fn = OVL_CURRENT (fns);
2078 if (TREE_CODE (fn) == TEMPLATE_DECL
2079 || TREE_CODE (fn) == TEMPLATE_ID_EXPR)
2081 if (TREE_CODE (fn) == FUNCTION_DECL
2082 && DECL_USE_TEMPLATE (fn)
2083 && PRIMARY_TEMPLATE_P (DECL_TI_TEMPLATE (fn)))
2085 fns = OVL_NEXT (fns);
2088 pedwarn ("%qD is not a template", decl);
2093 /* This function is called by the parser to process a class member
2094 access expression of the form OBJECT.NAME. NAME is a node used by
2095 the parser to represent a name; it is not yet a DECL. It may,
2096 however, be a BASELINK where the BASELINK_FUNCTIONS is a
2097 TEMPLATE_ID_EXPR. Templates must be looked up by the parser, and
2098 there is no reason to do the lookup twice, so the parser keeps the
2099 BASELINK. TEMPLATE_P is true iff NAME was explicitly declared to
2100 be a template via the use of the "A::template B" syntax. */
2103 finish_class_member_access_expr (tree object, tree name, bool template_p)
2108 tree access_path = NULL_TREE;
2109 tree orig_object = object;
2110 tree orig_name = name;
2112 if (object == error_mark_node || name == error_mark_node)
2113 return error_mark_node;
2115 /* If OBJECT is an ObjC class instance, we must obey ObjC access rules. */
2116 if (!objc_is_public (object, name))
2117 return error_mark_node;
2119 object_type = TREE_TYPE (object);
2121 if (processing_template_decl)
2123 if (/* If OBJECT_TYPE is dependent, so is OBJECT.NAME. */
2124 dependent_type_p (object_type)
2125 /* If NAME is just an IDENTIFIER_NODE, then the expression
2127 || TREE_CODE (object) == IDENTIFIER_NODE
2128 /* If NAME is "f<args>", where either 'f' or 'args' is
2129 dependent, then the expression is dependent. */
2130 || (TREE_CODE (name) == TEMPLATE_ID_EXPR
2131 && dependent_template_id_p (TREE_OPERAND (name, 0),
2132 TREE_OPERAND (name, 1)))
2133 /* If NAME is "T::X" where "T" is dependent, then the
2134 expression is dependent. */
2135 || (TREE_CODE (name) == SCOPE_REF
2136 && TYPE_P (TREE_OPERAND (name, 0))
2137 && dependent_type_p (TREE_OPERAND (name, 0))))
2138 return build_min_nt (COMPONENT_REF, object, name, NULL_TREE);
2139 object = build_non_dependent_expr (object);
2144 The type of the first expression shall be "class object" (of a
2146 if (!currently_open_class (object_type)
2147 && !complete_type_or_else (object_type, object))
2148 return error_mark_node;
2149 if (!CLASS_TYPE_P (object_type))
2151 error ("request for member %qD in %qE, which is of non-class type %qT",
2152 name, object, object_type);
2153 return error_mark_node;
2156 if (BASELINK_P (name))
2157 /* A member function that has already been looked up. */
2161 bool is_template_id = false;
2162 tree template_args = NULL_TREE;
2165 if (TREE_CODE (name) == TEMPLATE_ID_EXPR)
2167 is_template_id = true;
2168 template_args = TREE_OPERAND (name, 1);
2169 name = TREE_OPERAND (name, 0);
2171 if (TREE_CODE (name) == OVERLOAD)
2172 name = DECL_NAME (get_first_fn (name));
2173 else if (DECL_P (name))
2174 name = DECL_NAME (name);
2177 if (TREE_CODE (name) == SCOPE_REF)
2179 /* A qualified name. The qualifying class or namespace `S'
2180 has already been looked up; it is either a TYPE or a
2182 scope = TREE_OPERAND (name, 0);
2183 name = TREE_OPERAND (name, 1);
2185 /* If SCOPE is a namespace, then the qualified name does not
2186 name a member of OBJECT_TYPE. */
2187 if (TREE_CODE (scope) == NAMESPACE_DECL)
2189 error ("%<%D::%D%> is not a member of %qT",
2190 scope, name, object_type);
2191 return error_mark_node;
2194 gcc_assert (CLASS_TYPE_P (scope));
2195 gcc_assert (TREE_CODE (name) == IDENTIFIER_NODE
2196 || TREE_CODE (name) == BIT_NOT_EXPR);
2198 /* Find the base of OBJECT_TYPE corresponding to SCOPE. */
2199 access_path = lookup_base (object_type, scope, ba_check, NULL);
2200 if (access_path == error_mark_node)
2201 return error_mark_node;
2204 error ("%qT is not a base of %qT", scope, object_type);
2205 return error_mark_node;
2211 access_path = object_type;
2214 if (TREE_CODE (name) == BIT_NOT_EXPR)
2215 member = lookup_destructor (object, scope, name);
2218 /* Look up the member. */
2219 member = lookup_member (access_path, name, /*protect=*/1,
2220 /*want_type=*/false);
2221 if (member == NULL_TREE)
2223 error ("%qD has no member named %qE", object_type, name);
2224 return error_mark_node;
2226 if (member == error_mark_node)
2227 return error_mark_node;
2232 tree template = member;
2234 if (BASELINK_P (template))
2235 template = lookup_template_function (template, template_args);
2238 error ("%qD is not a member template function", name);
2239 return error_mark_node;
2244 if (TREE_DEPRECATED (member))
2245 warn_deprecated_use (member);
2248 check_template_keyword (member);
2250 expr = build_class_member_access_expr (object, member, access_path,
2251 /*preserve_reference=*/false);
2252 if (processing_template_decl && expr != error_mark_node)
2254 if (BASELINK_P (member))
2256 if (TREE_CODE (orig_name) == SCOPE_REF)
2257 BASELINK_QUALIFIED_P (member) = 1;
2260 return build_min_non_dep (COMPONENT_REF, expr,
2261 orig_object, orig_name,
2268 /* Return an expression for the MEMBER_NAME field in the internal
2269 representation of PTRMEM, a pointer-to-member function. (Each
2270 pointer-to-member function type gets its own RECORD_TYPE so it is
2271 more convenient to access the fields by name than by FIELD_DECL.)
2272 This routine converts the NAME to a FIELD_DECL and then creates the
2273 node for the complete expression. */
2276 build_ptrmemfunc_access_expr (tree ptrmem, tree member_name)
2282 /* This code is a stripped down version of
2283 build_class_member_access_expr. It does not work to use that
2284 routine directly because it expects the object to be of class
2286 ptrmem_type = TREE_TYPE (ptrmem);
2287 gcc_assert (TYPE_PTRMEMFUNC_P (ptrmem_type));
2288 member = lookup_member (ptrmem_type, member_name, /*protect=*/0,
2289 /*want_type=*/false);
2290 member_type = cp_build_qualified_type (TREE_TYPE (member),
2291 cp_type_quals (ptrmem_type));
2292 return fold_build3 (COMPONENT_REF, member_type,
2293 ptrmem, member, NULL_TREE);
2296 /* Given an expression PTR for a pointer, return an expression
2297 for the value pointed to.
2298 ERRORSTRING is the name of the operator to appear in error messages.
2300 This function may need to overload OPERATOR_FNNAME.
2301 Must also handle REFERENCE_TYPEs for C++. */
2304 build_x_indirect_ref (tree expr, const char *errorstring)
2306 tree orig_expr = expr;
2309 if (processing_template_decl)
2311 if (type_dependent_expression_p (expr))
2312 return build_min_nt (INDIRECT_REF, expr);
2313 expr = build_non_dependent_expr (expr);
2316 rval = build_new_op (INDIRECT_REF, LOOKUP_NORMAL, expr, NULL_TREE,
2317 NULL_TREE, /*overloaded_p=*/NULL);
2319 rval = build_indirect_ref (expr, errorstring);
2321 if (processing_template_decl && rval != error_mark_node)
2322 return build_min_non_dep (INDIRECT_REF, rval, orig_expr);
2328 build_indirect_ref (tree ptr, const char *errorstring)
2332 if (ptr == error_mark_node)
2333 return error_mark_node;
2335 if (ptr == current_class_ptr)
2336 return current_class_ref;
2338 pointer = (TREE_CODE (TREE_TYPE (ptr)) == REFERENCE_TYPE
2339 ? ptr : decay_conversion (ptr));
2340 type = TREE_TYPE (pointer);
2342 if (POINTER_TYPE_P (type))
2346 If the type of the expression is "pointer to T," the type
2347 of the result is "T."
2349 We must use the canonical variant because certain parts of
2350 the back end, like fold, do pointer comparisons between
2352 tree t = canonical_type_variant (TREE_TYPE (type));
2354 if (VOID_TYPE_P (t))
2356 /* A pointer to incomplete type (other than cv void) can be
2357 dereferenced [expr.unary.op]/1 */
2358 error ("%qT is not a pointer-to-object type", type);
2359 return error_mark_node;
2361 else if (TREE_CODE (pointer) == ADDR_EXPR
2362 && same_type_p (t, TREE_TYPE (TREE_OPERAND (pointer, 0))))
2363 /* The POINTER was something like `&x'. We simplify `*&x' to
2365 return TREE_OPERAND (pointer, 0);
2368 tree ref = build1 (INDIRECT_REF, t, pointer);
2370 /* We *must* set TREE_READONLY when dereferencing a pointer to const,
2371 so that we get the proper error message if the result is used
2372 to assign to. Also, &* is supposed to be a no-op. */
2373 TREE_READONLY (ref) = CP_TYPE_CONST_P (t);
2374 TREE_THIS_VOLATILE (ref) = CP_TYPE_VOLATILE_P (t);
2375 TREE_SIDE_EFFECTS (ref)
2376 = (TREE_THIS_VOLATILE (ref) || TREE_SIDE_EFFECTS (pointer));
2380 /* `pointer' won't be an error_mark_node if we were given a
2381 pointer to member, so it's cool to check for this here. */
2382 else if (TYPE_PTR_TO_MEMBER_P (type))
2383 error ("invalid use of %qs on pointer to member", errorstring);
2384 else if (pointer != error_mark_node)
2387 error ("invalid type argument of %qs", errorstring);
2389 error ("invalid type argument");
2391 return error_mark_node;
2394 /* This handles expressions of the form "a[i]", which denotes
2397 This is logically equivalent in C to *(a+i), but we may do it differently.
2398 If A is a variable or a member, we generate a primitive ARRAY_REF.
2399 This avoids forcing the array out of registers, and can work on
2400 arrays that are not lvalues (for example, members of structures returned
2403 If INDEX is of some user-defined type, it must be converted to
2404 integer type. Otherwise, to make a compatible PLUS_EXPR, it
2405 will inherit the type of the array, which will be some pointer type. */
2408 build_array_ref (tree array, tree idx)
2412 error ("subscript missing in array reference");
2413 return error_mark_node;
2416 if (TREE_TYPE (array) == error_mark_node
2417 || TREE_TYPE (idx) == error_mark_node)
2418 return error_mark_node;
2420 /* If ARRAY is a COMPOUND_EXPR or COND_EXPR, move our reference
2422 switch (TREE_CODE (array))
2426 tree value = build_array_ref (TREE_OPERAND (array, 1), idx);
2427 return build2 (COMPOUND_EXPR, TREE_TYPE (value),
2428 TREE_OPERAND (array, 0), value);
2432 return build_conditional_expr
2433 (TREE_OPERAND (array, 0),
2434 build_array_ref (TREE_OPERAND (array, 1), idx),
2435 build_array_ref (TREE_OPERAND (array, 2), idx));
2441 if (TREE_CODE (TREE_TYPE (array)) == ARRAY_TYPE)
2445 warn_array_subscript_with_type_char (idx);
2447 if (!INTEGRAL_OR_ENUMERATION_TYPE_P (TREE_TYPE (idx)))
2449 error ("array subscript is not an integer");
2450 return error_mark_node;
2453 /* Apply integral promotions *after* noticing character types.
2454 (It is unclear why we do these promotions -- the standard
2455 does not say that we should. In fact, the natural thing would
2456 seem to be to convert IDX to ptrdiff_t; we're performing
2457 pointer arithmetic.) */
2458 idx = perform_integral_promotions (idx);
2460 /* An array that is indexed by a non-constant
2461 cannot be stored in a register; we must be able to do
2462 address arithmetic on its address.
2463 Likewise an array of elements of variable size. */
2464 if (TREE_CODE (idx) != INTEGER_CST
2465 || (COMPLETE_TYPE_P (TREE_TYPE (TREE_TYPE (array)))
2466 && (TREE_CODE (TYPE_SIZE (TREE_TYPE (TREE_TYPE (array))))
2469 if (!cxx_mark_addressable (array))
2470 return error_mark_node;
2473 /* An array that is indexed by a constant value which is not within
2474 the array bounds cannot be stored in a register either; because we
2475 would get a crash in store_bit_field/extract_bit_field when trying
2476 to access a non-existent part of the register. */
2477 if (TREE_CODE (idx) == INTEGER_CST
2478 && TYPE_DOMAIN (TREE_TYPE (array))
2479 && ! int_fits_type_p (idx, TYPE_DOMAIN (TREE_TYPE (array))))
2481 if (!cxx_mark_addressable (array))
2482 return error_mark_node;
2485 if (pedantic && !lvalue_p (array))
2486 pedwarn ("ISO C++ forbids subscripting non-lvalue array");
2488 /* Note in C++ it is valid to subscript a `register' array, since
2489 it is valid to take the address of something with that
2490 storage specification. */
2494 while (TREE_CODE (foo) == COMPONENT_REF)
2495 foo = TREE_OPERAND (foo, 0);
2496 if (TREE_CODE (foo) == VAR_DECL && DECL_REGISTER (foo))
2497 warning (OPT_Wextra, "subscripting array declared %<register%>");
2500 type = TREE_TYPE (TREE_TYPE (array));
2501 rval = build4 (ARRAY_REF, type, array, idx, NULL_TREE, NULL_TREE);
2502 /* Array ref is const/volatile if the array elements are
2503 or if the array is.. */
2504 TREE_READONLY (rval)
2505 |= (CP_TYPE_CONST_P (type) | TREE_READONLY (array));
2506 TREE_SIDE_EFFECTS (rval)
2507 |= (CP_TYPE_VOLATILE_P (type) | TREE_SIDE_EFFECTS (array));
2508 TREE_THIS_VOLATILE (rval)
2509 |= (CP_TYPE_VOLATILE_P (type) | TREE_THIS_VOLATILE (array));
2510 return require_complete_type (fold_if_not_in_template (rval));
2514 tree ar = default_conversion (array);
2515 tree ind = default_conversion (idx);
2517 /* Put the integer in IND to simplify error checking. */
2518 if (TREE_CODE (TREE_TYPE (ar)) == INTEGER_TYPE)
2525 if (ar == error_mark_node)
2528 if (TREE_CODE (TREE_TYPE (ar)) != POINTER_TYPE)
2530 error ("subscripted value is neither array nor pointer");
2531 return error_mark_node;
2533 if (TREE_CODE (TREE_TYPE (ind)) != INTEGER_TYPE)
2535 error ("array subscript is not an integer");
2536 return error_mark_node;
2539 warn_array_subscript_with_type_char (idx);
2541 return build_indirect_ref (cp_build_binary_op (PLUS_EXPR, ar, ind),
2546 /* Resolve a pointer to member function. INSTANCE is the object
2547 instance to use, if the member points to a virtual member.
2549 This used to avoid checking for virtual functions if basetype
2550 has no virtual functions, according to an earlier ANSI draft.
2551 With the final ISO C++ rules, such an optimization is
2552 incorrect: A pointer to a derived member can be static_cast
2553 to pointer-to-base-member, as long as the dynamic object
2554 later has the right member. */
2557 get_member_function_from_ptrfunc (tree *instance_ptrptr, tree function)
2559 if (TREE_CODE (function) == OFFSET_REF)
2560 function = TREE_OPERAND (function, 1);
2562 if (TYPE_PTRMEMFUNC_P (TREE_TYPE (function)))
2564 tree idx, delta, e1, e2, e3, vtbl, basetype;
2565 tree fntype = TYPE_PTRMEMFUNC_FN_TYPE (TREE_TYPE (function));
2567 tree instance_ptr = *instance_ptrptr;
2568 tree instance_save_expr = 0;
2569 if (instance_ptr == error_mark_node)
2571 if (TREE_CODE (function) == PTRMEM_CST)
2573 /* Extracting the function address from a pmf is only
2574 allowed with -Wno-pmf-conversions. It only works for
2576 e1 = build_addr_func (PTRMEM_CST_MEMBER (function));
2577 e1 = convert (fntype, e1);
2582 error ("object missing in use of %qE", function);
2583 return error_mark_node;
2587 if (TREE_SIDE_EFFECTS (instance_ptr))
2588 instance_ptr = instance_save_expr = save_expr (instance_ptr);
2590 if (TREE_SIDE_EFFECTS (function))
2591 function = save_expr (function);
2593 /* Start by extracting all the information from the PMF itself. */
2594 e3 = pfn_from_ptrmemfunc (function);
2595 delta = build_ptrmemfunc_access_expr (function, delta_identifier);
2596 idx = build1 (NOP_EXPR, vtable_index_type, e3);
2597 switch (TARGET_PTRMEMFUNC_VBIT_LOCATION)
2599 case ptrmemfunc_vbit_in_pfn:
2600 e1 = cp_build_binary_op (BIT_AND_EXPR, idx, integer_one_node);
2601 idx = cp_build_binary_op (MINUS_EXPR, idx, integer_one_node);
2604 case ptrmemfunc_vbit_in_delta:
2605 e1 = cp_build_binary_op (BIT_AND_EXPR, delta, integer_one_node);
2606 delta = cp_build_binary_op (RSHIFT_EXPR, delta, integer_one_node);
2613 /* Convert down to the right base before using the instance. A
2614 special case is that in a pointer to member of class C, C may
2615 be incomplete. In that case, the function will of course be
2616 a member of C, and no conversion is required. In fact,
2617 lookup_base will fail in that case, because incomplete
2618 classes do not have BINFOs. */
2619 basetype = TYPE_METHOD_BASETYPE (TREE_TYPE (fntype));
2620 if (!same_type_ignoring_top_level_qualifiers_p
2621 (basetype, TREE_TYPE (TREE_TYPE (instance_ptr))))
2623 basetype = lookup_base (TREE_TYPE (TREE_TYPE (instance_ptr)),
2624 basetype, ba_check, NULL);
2625 instance_ptr = build_base_path (PLUS_EXPR, instance_ptr, basetype,
2627 if (instance_ptr == error_mark_node)
2628 return error_mark_node;
2630 /* ...and then the delta in the PMF. */
2631 instance_ptr = build2 (PLUS_EXPR, TREE_TYPE (instance_ptr),
2632 instance_ptr, delta);
2634 /* Hand back the adjusted 'this' argument to our caller. */
2635 *instance_ptrptr = instance_ptr;
2637 /* Next extract the vtable pointer from the object. */
2638 vtbl = build1 (NOP_EXPR, build_pointer_type (vtbl_ptr_type_node),
2640 vtbl = build_indirect_ref (vtbl, NULL);
2642 /* Finally, extract the function pointer from the vtable. */
2643 e2 = fold_build2 (PLUS_EXPR, TREE_TYPE (vtbl), vtbl, idx);
2644 e2 = build_indirect_ref (e2, NULL);
2645 TREE_CONSTANT (e2) = 1;
2646 TREE_INVARIANT (e2) = 1;
2648 /* When using function descriptors, the address of the
2649 vtable entry is treated as a function pointer. */
2650 if (TARGET_VTABLE_USES_DESCRIPTORS)
2651 e2 = build1 (NOP_EXPR, TREE_TYPE (e2),
2652 build_unary_op (ADDR_EXPR, e2, /*noconvert=*/1));
2654 TREE_TYPE (e2) = TREE_TYPE (e3);
2655 e1 = build_conditional_expr (e1, e2, e3);
2657 /* Make sure this doesn't get evaluated first inside one of the
2658 branches of the COND_EXPR. */
2659 if (instance_save_expr)
2660 e1 = build2 (COMPOUND_EXPR, TREE_TYPE (e1),
2661 instance_save_expr, e1);
2669 build_function_call (tree function, tree params)
2671 tree fntype, fndecl;
2672 tree coerced_params;
2673 tree name = NULL_TREE;
2675 tree original = function;
2677 /* For Objective-C, convert any calls via a cast to OBJC_TYPE_REF
2678 expressions, like those used for ObjC messenger dispatches. */
2679 function = objc_rewrite_function_call (function, params);
2681 /* build_c_cast puts on a NOP_EXPR to make the result not an lvalue.
2682 Strip such NOP_EXPRs, since FUNCTION is used in non-lvalue context. */
2683 if (TREE_CODE (function) == NOP_EXPR
2684 && TREE_TYPE (function) == TREE_TYPE (TREE_OPERAND (function, 0)))
2685 function = TREE_OPERAND (function, 0);
2687 if (TREE_CODE (function) == FUNCTION_DECL)
2689 name = DECL_NAME (function);
2691 mark_used (function);
2694 /* Convert anything with function type to a pointer-to-function. */
2695 if (pedantic && DECL_MAIN_P (function))
2696 pedwarn ("ISO C++ forbids calling %<::main%> from within program");
2698 /* Differs from default_conversion by not setting TREE_ADDRESSABLE
2699 (because calling an inline function does not mean the function
2700 needs to be separately compiled). */
2702 if (DECL_INLINE (function))
2703 function = inline_conversion (function);
2705 function = build_addr_func (function);
2711 function = build_addr_func (function);
2714 if (function == error_mark_node)
2715 return error_mark_node;
2717 fntype = TREE_TYPE (function);
2719 if (TYPE_PTRMEMFUNC_P (fntype))
2721 error ("must use %<.*%> or %<->*%> to call pointer-to-member "
2722 "function in %<%E (...)%>",
2724 return error_mark_node;
2727 is_method = (TREE_CODE (fntype) == POINTER_TYPE
2728 && TREE_CODE (TREE_TYPE (fntype)) == METHOD_TYPE);
2730 if (!((TREE_CODE (fntype) == POINTER_TYPE
2731 && TREE_CODE (TREE_TYPE (fntype)) == FUNCTION_TYPE)
2733 || TREE_CODE (function) == TEMPLATE_ID_EXPR))
2735 error ("%qE cannot be used as a function", original);
2736 return error_mark_node;
2739 /* fntype now gets the type of function pointed to. */
2740 fntype = TREE_TYPE (fntype);
2742 /* Convert the parameters to the types declared in the
2743 function prototype, or apply default promotions. */
2745 coerced_params = convert_arguments (TYPE_ARG_TYPES (fntype),
2746 params, fndecl, LOOKUP_NORMAL);
2747 if (coerced_params == error_mark_node)
2748 return error_mark_node;
2750 /* Check for errors in format strings and inappropriately
2753 check_function_arguments (TYPE_ATTRIBUTES (fntype), coerced_params,
2754 TYPE_ARG_TYPES (fntype));
2756 return build_cxx_call (function, coerced_params);
2759 /* Convert the actual parameter expressions in the list VALUES
2760 to the types in the list TYPELIST.
2761 If parmdecls is exhausted, or when an element has NULL as its type,
2762 perform the default conversions.
2764 NAME is an IDENTIFIER_NODE or 0. It is used only for error messages.
2766 This is also where warnings about wrong number of args are generated.
2768 Return a list of expressions for the parameters as converted.
2770 Both VALUES and the returned value are chains of TREE_LIST nodes
2771 with the elements of the list in the TREE_VALUE slots of those nodes.
2773 In C++, unspecified trailing parameters can be filled in with their
2774 default arguments, if such were specified. Do so here. */
2777 convert_arguments (tree typelist, tree values, tree fndecl, int flags)
2779 tree typetail, valtail;
2780 tree result = NULL_TREE;
2781 const char *called_thing = 0;
2784 /* Argument passing is always copy-initialization. */
2785 flags |= LOOKUP_ONLYCONVERTING;
2789 if (TREE_CODE (TREE_TYPE (fndecl)) == METHOD_TYPE)
2791 if (DECL_NAME (fndecl) == NULL_TREE
2792 || IDENTIFIER_HAS_TYPE_VALUE (DECL_NAME (fndecl)))
2793 called_thing = "constructor";
2795 called_thing = "member function";
2798 called_thing = "function";
2801 for (valtail = values, typetail = typelist;
2803 valtail = TREE_CHAIN (valtail), i++)
2805 tree type = typetail ? TREE_VALUE (typetail) : 0;
2806 tree val = TREE_VALUE (valtail);
2808 if (val == error_mark_node || type == error_mark_node)
2809 return error_mark_node;
2811 if (type == void_type_node)
2815 error ("too many arguments to %s %q+#D", called_thing, fndecl);
2816 error ("at this point in file");
2819 error ("too many arguments to function");
2820 /* In case anybody wants to know if this argument
2823 TREE_TYPE (tree_last (result)) = error_mark_node;
2827 /* build_c_cast puts on a NOP_EXPR to make the result not an lvalue.
2828 Strip such NOP_EXPRs, since VAL is used in non-lvalue context. */
2829 if (TREE_CODE (val) == NOP_EXPR
2830 && TREE_TYPE (val) == TREE_TYPE (TREE_OPERAND (val, 0))
2831 && (type == 0 || TREE_CODE (type) != REFERENCE_TYPE))
2832 val = TREE_OPERAND (val, 0);
2834 if (type == 0 || TREE_CODE (type) != REFERENCE_TYPE)
2836 if (TREE_CODE (TREE_TYPE (val)) == ARRAY_TYPE
2837 || TREE_CODE (TREE_TYPE (val)) == FUNCTION_TYPE
2838 || TREE_CODE (TREE_TYPE (val)) == METHOD_TYPE)
2839 val = decay_conversion (val);
2842 if (val == error_mark_node)
2843 return error_mark_node;
2847 /* Formal parm type is specified by a function prototype. */
2850 if (!COMPLETE_TYPE_P (complete_type (type)))
2853 error ("parameter %P of %qD has incomplete type %qT",
2856 error ("parameter %P has incomplete type %qT", i, type);
2857 parmval = error_mark_node;
2861 parmval = convert_for_initialization
2862 (NULL_TREE, type, val, flags,
2863 "argument passing", fndecl, i);
2864 parmval = convert_for_arg_passing (type, parmval);
2867 if (parmval == error_mark_node)
2868 return error_mark_node;
2870 result = tree_cons (NULL_TREE, parmval, result);
2874 if (fndecl && DECL_BUILT_IN (fndecl)
2875 && DECL_FUNCTION_CODE (fndecl) == BUILT_IN_CONSTANT_P)
2876 /* Don't do ellipsis conversion for __built_in_constant_p
2877 as this will result in spurious warnings for non-POD
2879 val = require_complete_type (val);
2881 val = convert_arg_to_ellipsis (val);
2883 result = tree_cons (NULL_TREE, val, result);
2887 typetail = TREE_CHAIN (typetail);
2890 if (typetail != 0 && typetail != void_list_node)
2892 /* See if there are default arguments that can be used. */
2893 if (TREE_PURPOSE (typetail)
2894 && TREE_CODE (TREE_PURPOSE (typetail)) != DEFAULT_ARG)
2896 for (; typetail != void_list_node; ++i)
2899 = convert_default_arg (TREE_VALUE (typetail),
2900 TREE_PURPOSE (typetail),
2903 if (parmval == error_mark_node)
2904 return error_mark_node;
2906 result = tree_cons (0, parmval, result);
2907 typetail = TREE_CHAIN (typetail);
2908 /* ends with `...'. */
2909 if (typetail == NULL_TREE)
2917 error ("too few arguments to %s %q+#D", called_thing, fndecl);
2918 error ("at this point in file");
2921 error ("too few arguments to function");
2922 return error_mark_node;
2926 return nreverse (result);
2929 /* Build a binary-operation expression, after performing default
2930 conversions on the operands. CODE is the kind of expression to
2931 build. ARG1 and ARG2 are the arguments. ARG1_CODE and ARG2_CODE
2932 are the tree codes which correspond to ARG1 and ARG2 when issuing
2933 warnings about possibly misplaced parentheses. They may differ
2934 from the TREE_CODE of ARG1 and ARG2 if the parser has done constant
2935 folding (e.g., if the parser sees "a | 1 + 1", it may call this
2936 routine with ARG2 being an INTEGER_CST and ARG2_CODE == PLUS_EXPR).
2937 To avoid issuing any parentheses warnings, pass ARG1_CODE and/or
2938 ARG2_CODE as ERROR_MARK. */
2941 build_x_binary_op (enum tree_code code, tree arg1, enum tree_code arg1_code,
2942 tree arg2, enum tree_code arg2_code, bool *overloaded_p)
2951 if (processing_template_decl)
2953 if (type_dependent_expression_p (arg1)
2954 || type_dependent_expression_p (arg2))
2955 return build_min_nt (code, arg1, arg2);
2956 arg1 = build_non_dependent_expr (arg1);
2957 arg2 = build_non_dependent_expr (arg2);
2960 if (code == DOTSTAR_EXPR)
2961 expr = build_m_component_ref (arg1, arg2);
2963 expr = build_new_op (code, LOOKUP_NORMAL, arg1, arg2, NULL_TREE,
2966 /* Check for cases such as x+y<<z which users are likely to
2967 misinterpret. But don't warn about obj << x + y, since that is a
2968 common idiom for I/O. */
2969 if (warn_parentheses
2970 && !processing_template_decl
2971 && !error_operand_p (arg1)
2972 && !error_operand_p (arg2)
2973 && (code != LSHIFT_EXPR
2974 || !CLASS_TYPE_P (TREE_TYPE (arg1))))
2975 warn_about_parentheses (code, arg1_code, arg2_code);
2977 if (processing_template_decl && expr != error_mark_node)
2978 return build_min_non_dep (code, expr, orig_arg1, orig_arg2);
2983 /* Build a binary-operation expression without default conversions.
2984 CODE is the kind of expression to build.
2985 This function differs from `build' in several ways:
2986 the data type of the result is computed and recorded in it,
2987 warnings are generated if arg data types are invalid,
2988 special handling for addition and subtraction of pointers is known,
2989 and some optimization is done (operations on narrow ints
2990 are done in the narrower type when that gives the same result).
2991 Constant folding is also done before the result is returned.
2993 Note that the operands will never have enumeral types
2994 because either they have just had the default conversions performed
2995 or they have both just been converted to some other type in which
2996 the arithmetic is to be done.
2998 C++: must do special pointer arithmetic when implementing
2999 multiple inheritance, and deal with pointer to member functions. */
3002 build_binary_op (enum tree_code code, tree orig_op0, tree orig_op1,
3003 int convert_p ATTRIBUTE_UNUSED)
3006 enum tree_code code0, code1;
3008 const char *invalid_op_diag;
3010 /* Expression code to give to the expression when it is built.
3011 Normally this is CODE, which is what the caller asked for,
3012 but in some special cases we change it. */
3013 enum tree_code resultcode = code;
3015 /* Data type in which the computation is to be performed.
3016 In the simplest cases this is the common type of the arguments. */
3017 tree result_type = NULL;
3019 /* Nonzero means operands have already been type-converted
3020 in whatever way is necessary.
3021 Zero means they need to be converted to RESULT_TYPE. */
3024 /* Nonzero means create the expression with this type, rather than
3026 tree build_type = 0;
3028 /* Nonzero means after finally constructing the expression
3029 convert it to this type. */
3030 tree final_type = 0;
3034 /* Nonzero if this is an operation like MIN or MAX which can
3035 safely be computed in short if both args are promoted shorts.
3036 Also implies COMMON.
3037 -1 indicates a bitwise operation; this makes a difference
3038 in the exact conditions for when it is safe to do the operation
3039 in a narrower mode. */
3042 /* Nonzero if this is a comparison operation;
3043 if both args are promoted shorts, compare the original shorts.
3044 Also implies COMMON. */
3045 int short_compare = 0;
3047 /* Nonzero if this is a right-shift operation, which can be computed on the
3048 original short and then promoted if the operand is a promoted short. */
3049 int short_shift = 0;
3051 /* Nonzero means set RESULT_TYPE to the common type of the args. */
3054 /* True if both operands have arithmetic type. */
3055 bool arithmetic_types_p;
3057 /* Apply default conversions. */
3061 if (code == TRUTH_AND_EXPR || code == TRUTH_ANDIF_EXPR
3062 || code == TRUTH_OR_EXPR || code == TRUTH_ORIF_EXPR
3063 || code == TRUTH_XOR_EXPR)
3065 if (!really_overloaded_fn (op0))
3066 op0 = decay_conversion (op0);
3067 if (!really_overloaded_fn (op1))
3068 op1 = decay_conversion (op1);
3072 if (!really_overloaded_fn (op0))
3073 op0 = default_conversion (op0);
3074 if (!really_overloaded_fn (op1))
3075 op1 = default_conversion (op1);
3078 /* Strip NON_LVALUE_EXPRs, etc., since we aren't using as an lvalue. */
3079 STRIP_TYPE_NOPS (op0);
3080 STRIP_TYPE_NOPS (op1);
3082 /* DTRT if one side is an overloaded function, but complain about it. */
3083 if (type_unknown_p (op0))
3085 tree t = instantiate_type (TREE_TYPE (op1), op0, tf_none);
3086 if (t != error_mark_node)
3088 pedwarn ("assuming cast to type %qT from overloaded function",
3093 if (type_unknown_p (op1))
3095 tree t = instantiate_type (TREE_TYPE (op0), op1, tf_none);
3096 if (t != error_mark_node)
3098 pedwarn ("assuming cast to type %qT from overloaded function",
3104 type0 = TREE_TYPE (op0);
3105 type1 = TREE_TYPE (op1);
3107 /* The expression codes of the data types of the arguments tell us
3108 whether the arguments are integers, floating, pointers, etc. */
3109 code0 = TREE_CODE (type0);
3110 code1 = TREE_CODE (type1);
3112 /* If an error was already reported for one of the arguments,
3113 avoid reporting another error. */
3115 if (code0 == ERROR_MARK || code1 == ERROR_MARK)
3116 return error_mark_node;
3118 if ((invalid_op_diag
3119 = targetm.invalid_binary_op (code, type0, type1)))
3121 error (invalid_op_diag);
3122 return error_mark_node;
3128 /* Subtraction of two similar pointers.
3129 We must subtract them as integers, then divide by object size. */
3130 if (code0 == POINTER_TYPE && code1 == POINTER_TYPE
3131 && same_type_ignoring_top_level_qualifiers_p (TREE_TYPE (type0),
3133 return pointer_diff (op0, op1, common_type (type0, type1));
3134 /* In all other cases except pointer - int, the usual arithmetic
3136 else if (!(code0 == POINTER_TYPE && code1 == INTEGER_TYPE))
3141 /* The pointer - int case is just like pointer + int; fall
3144 if ((code0 == POINTER_TYPE || code1 == POINTER_TYPE)
3145 && (code0 == INTEGER_TYPE || code1 == INTEGER_TYPE))
3149 ptr_operand = ((code0 == POINTER_TYPE) ? op0 : op1);
3150 int_operand = ((code0 == INTEGER_TYPE) ? op0 : op1);
3151 if (processing_template_decl)
3153 result_type = TREE_TYPE (ptr_operand);
3156 return cp_pointer_int_sum (code,
3167 case TRUNC_DIV_EXPR:
3169 case FLOOR_DIV_EXPR:
3170 case ROUND_DIV_EXPR:
3171 case EXACT_DIV_EXPR:
3172 if ((code0 == INTEGER_TYPE || code0 == REAL_TYPE
3173 || code0 == COMPLEX_TYPE || code0 == VECTOR_TYPE)
3174 && (code1 == INTEGER_TYPE || code1 == REAL_TYPE
3175 || code1 == COMPLEX_TYPE || code1 == VECTOR_TYPE))
3177 enum tree_code tcode0 = code0, tcode1 = code1;
3179 if (TREE_CODE (op1) == INTEGER_CST && integer_zerop (op1))
3180 warning (OPT_Wdiv_by_zero, "division by zero in %<%E / 0%>", op0);
3181 else if (TREE_CODE (op1) == REAL_CST && real_zerop (op1))
3182 warning (OPT_Wdiv_by_zero, "division by zero in %<%E / 0.%>", op0);
3184 if (tcode0 == COMPLEX_TYPE || tcode0 == VECTOR_TYPE)
3185 tcode0 = TREE_CODE (TREE_TYPE (TREE_TYPE (op0)));
3186 if (tcode1 == COMPLEX_TYPE || tcode1 == VECTOR_TYPE)
3187 tcode1 = TREE_CODE (TREE_TYPE (TREE_TYPE (op1)));
3189 if (!(tcode0 == INTEGER_TYPE && tcode1 == INTEGER_TYPE))
3190 resultcode = RDIV_EXPR;
3192 /* When dividing two signed integers, we have to promote to int.
3193 unless we divide by a constant != -1. Note that default
3194 conversion will have been performed on the operands at this
3195 point, so we have to dig out the original type to find out if
3197 shorten = ((TREE_CODE (op0) == NOP_EXPR
3198 && TYPE_UNSIGNED (TREE_TYPE (TREE_OPERAND (op0, 0))))
3199 || (TREE_CODE (op1) == INTEGER_CST
3200 && ! integer_all_onesp (op1)));
3209 if ((code0 == INTEGER_TYPE && code1 == INTEGER_TYPE)
3210 || (code0 == VECTOR_TYPE && code1 == VECTOR_TYPE))
3214 case TRUNC_MOD_EXPR:
3215 case FLOOR_MOD_EXPR:
3216 if (code1 == INTEGER_TYPE && integer_zerop (op1))
3217 warning (OPT_Wdiv_by_zero, "division by zero in %<%E %% 0%>", op0);
3218 else if (code1 == REAL_TYPE && real_zerop (op1))
3219 warning (OPT_Wdiv_by_zero, "division by zero in %<%E %% 0.%>", op0);
3221 if (code0 == INTEGER_TYPE && code1 == INTEGER_TYPE)
3223 /* Although it would be tempting to shorten always here, that loses
3224 on some targets, since the modulo instruction is undefined if the
3225 quotient can't be represented in the computation mode. We shorten
3226 only if unsigned or if dividing by something we know != -1. */
3227 shorten = ((TREE_CODE (op0) == NOP_EXPR
3228 && TYPE_UNSIGNED (TREE_TYPE (TREE_OPERAND (op0, 0))))
3229 || (TREE_CODE (op1) == INTEGER_CST
3230 && ! integer_all_onesp (op1)));
3235 case TRUTH_ANDIF_EXPR:
3236 case TRUTH_ORIF_EXPR:
3237 case TRUTH_AND_EXPR:
3239 result_type = boolean_type_node;
3242 /* Shift operations: result has same type as first operand;
3243 always convert second operand to int.
3244 Also set SHORT_SHIFT if shifting rightward. */
3247 if (code0 == INTEGER_TYPE && code1 == INTEGER_TYPE)
3249 result_type = type0;
3250 if (TREE_CODE (op1) == INTEGER_CST)
3252 if (tree_int_cst_lt (op1, integer_zero_node))
3253 warning (0, "right shift count is negative");
3256 if (! integer_zerop (op1))
3258 if (compare_tree_int (op1, TYPE_PRECISION (type0)) >= 0)
3259 warning (0, "right shift count >= width of type");
3262 /* Convert the shift-count to an integer, regardless of
3263 size of value being shifted. */
3264 if (TYPE_MAIN_VARIANT (TREE_TYPE (op1)) != integer_type_node)
3265 op1 = cp_convert (integer_type_node, op1);
3266 /* Avoid converting op1 to result_type later. */
3272 if (code0 == INTEGER_TYPE && code1 == INTEGER_TYPE)
3274 result_type = type0;
3275 if (TREE_CODE (op1) == INTEGER_CST)
3277 if (tree_int_cst_lt (op1, integer_zero_node))
3278 warning (0, "left shift count is negative");
3279 else if (compare_tree_int (op1, TYPE_PRECISION (type0)) >= 0)
3280 warning (0, "left shift count >= width of type");
3282 /* Convert the shift-count to an integer, regardless of
3283 size of value being shifted. */
3284 if (TYPE_MAIN_VARIANT (TREE_TYPE (op1)) != integer_type_node)
3285 op1 = cp_convert (integer_type_node, op1);
3286 /* Avoid converting op1 to result_type later. */
3293 if (code0 == INTEGER_TYPE && code1 == INTEGER_TYPE)
3295 result_type = type0;
3296 if (TREE_CODE (op1) == INTEGER_CST)
3298 if (tree_int_cst_lt (op1, integer_zero_node))
3299 warning (0, (code == LROTATE_EXPR)
3300 ? G_("left rotate count is negative")
3301 : G_("right rotate count is negative"));
3302 else if (compare_tree_int (op1, TYPE_PRECISION (type0)) >= 0)
3303 warning (0, (code == LROTATE_EXPR)
3304 ? G_("left rotate count >= width of type")
3305 : G_("right rotate count >= width of type"));
3307 /* Convert the shift-count to an integer, regardless of
3308 size of value being shifted. */
3309 if (TYPE_MAIN_VARIANT (TREE_TYPE (op1)) != integer_type_node)
3310 op1 = cp_convert (integer_type_node, op1);
3316 if (code0 == REAL_TYPE || code1 == REAL_TYPE)
3317 warning (OPT_Wfloat_equal,
3318 "comparing floating point with == or != is unsafe");
3319 if ((TREE_CODE (orig_op0) == STRING_CST && !integer_zerop (op1))
3320 || (TREE_CODE (orig_op1) == STRING_CST && !integer_zerop (op0)))
3321 warning (OPT_Wstring_literal_comparison,
3322 "comparison with string literal");
3324 build_type = boolean_type_node;
3325 if ((code0 == INTEGER_TYPE || code0 == REAL_TYPE
3326 || code0 == COMPLEX_TYPE)
3327 && (code1 == INTEGER_TYPE || code1 == REAL_TYPE
3328 || code1 == COMPLEX_TYPE))
3330 else if ((code0 == POINTER_TYPE && code1 == POINTER_TYPE)
3331 || (TYPE_PTRMEM_P (type0) && TYPE_PTRMEM_P (type1)))
3332 result_type = composite_pointer_type (type0, type1, op0, op1,
3334 else if ((code0 == POINTER_TYPE || TYPE_PTRMEM_P (type0))
3335 && null_ptr_cst_p (op1))
3336 result_type = type0;
3337 else if ((code1 == POINTER_TYPE || TYPE_PTRMEM_P (type1))
3338 && null_ptr_cst_p (op0))
3339 result_type = type1;
3340 else if (code0 == POINTER_TYPE && code1 == INTEGER_TYPE)
3342 result_type = type0;
3343 error ("ISO C++ forbids comparison between pointer and integer");
3345 else if (code0 == INTEGER_TYPE && code1 == POINTER_TYPE)
3347 result_type = type1;
3348 error ("ISO C++ forbids comparison between pointer and integer");
3350 else if (TYPE_PTRMEMFUNC_P (type0) && null_ptr_cst_p (op1))
3352 if (TARGET_PTRMEMFUNC_VBIT_LOCATION
3353 == ptrmemfunc_vbit_in_delta)
3355 tree pfn0 = pfn_from_ptrmemfunc (op0);
3356 tree delta0 = build_ptrmemfunc_access_expr (op0,
3358 tree e1 = cp_build_binary_op (EQ_EXPR,
3360 fold_convert (TREE_TYPE (pfn0),
3361 integer_zero_node));
3362 tree e2 = cp_build_binary_op (BIT_AND_EXPR,
3365 e2 = cp_build_binary_op (EQ_EXPR, e2, integer_zero_node);
3366 op0 = cp_build_binary_op (TRUTH_ANDIF_EXPR, e1, e2);
3367 op1 = cp_convert (TREE_TYPE (op0), integer_one_node);
3371 op0 = build_ptrmemfunc_access_expr (op0, pfn_identifier);
3372 op1 = cp_convert (TREE_TYPE (op0), integer_zero_node);
3374 result_type = TREE_TYPE (op0);
3376 else if (TYPE_PTRMEMFUNC_P (type1) && null_ptr_cst_p (op0))
3377 return cp_build_binary_op (code, op1, op0);
3378 else if (TYPE_PTRMEMFUNC_P (type0) && TYPE_PTRMEMFUNC_P (type1)
3379 && same_type_p (type0, type1))
3381 /* E will be the final comparison. */
3383 /* E1 and E2 are for scratch. */
3391 if (TREE_SIDE_EFFECTS (op0))
3392 op0 = save_expr (op0);
3393 if (TREE_SIDE_EFFECTS (op1))
3394 op1 = save_expr (op1);
3396 pfn0 = pfn_from_ptrmemfunc (op0);
3397 pfn1 = pfn_from_ptrmemfunc (op1);
3398 delta0 = build_ptrmemfunc_access_expr (op0,
3400 delta1 = build_ptrmemfunc_access_expr (op1,
3402 if (TARGET_PTRMEMFUNC_VBIT_LOCATION
3403 == ptrmemfunc_vbit_in_delta)
3408 && ((op0.delta == op1.delta)
3409 || (!op0.pfn && op0.delta & 1 == 0
3410 && op1.delta & 1 == 0))
3412 The reason for the `!op0.pfn' bit is that a NULL
3413 pointer-to-member is any member with a zero PFN and
3414 LSB of the DELTA field is 0. */
3416 e1 = cp_build_binary_op (BIT_AND_EXPR,
3419 e1 = cp_build_binary_op (EQ_EXPR, e1, integer_zero_node);
3420 e2 = cp_build_binary_op (BIT_AND_EXPR,
3423 e2 = cp_build_binary_op (EQ_EXPR, e2, integer_zero_node);
3424 e1 = cp_build_binary_op (TRUTH_ANDIF_EXPR, e2, e1);
3425 e2 = cp_build_binary_op (EQ_EXPR,
3427 fold_convert (TREE_TYPE (pfn0),
3428 integer_zero_node));
3429 e2 = cp_build_binary_op (TRUTH_ANDIF_EXPR, e2, e1);
3430 e1 = cp_build_binary_op (EQ_EXPR, delta0, delta1);
3431 e1 = cp_build_binary_op (TRUTH_ORIF_EXPR, e1, e2);
3438 && (!op0.pfn || op0.delta == op1.delta))
3440 The reason for the `!op0.pfn' bit is that a NULL
3441 pointer-to-member is any member with a zero PFN; the
3442 DELTA field is unspecified. */
3444 e1 = cp_build_binary_op (EQ_EXPR, delta0, delta1);
3445 e2 = cp_build_binary_op (EQ_EXPR,
3447 fold_convert (TREE_TYPE (pfn0),
3448 integer_zero_node));
3449 e1 = cp_build_binary_op (TRUTH_ORIF_EXPR, e1, e2);
3451 e2 = build2 (EQ_EXPR, boolean_type_node, pfn0, pfn1);
3452 e = cp_build_binary_op (TRUTH_ANDIF_EXPR, e2, e1);
3453 if (code == EQ_EXPR)
3455 return cp_build_binary_op (EQ_EXPR, e, integer_zero_node);
3459 gcc_assert (!TYPE_PTRMEMFUNC_P (type0)
3460 || !same_type_p (TYPE_PTRMEMFUNC_FN_TYPE (type0),
3462 gcc_assert (!TYPE_PTRMEMFUNC_P (type1)
3463 || !same_type_p (TYPE_PTRMEMFUNC_FN_TYPE (type1),
3471 if ((code0 == INTEGER_TYPE || code0 == REAL_TYPE)
3472 && (code1 == INTEGER_TYPE || code1 == REAL_TYPE))
3474 else if (code0 == POINTER_TYPE && code1 == POINTER_TYPE)
3475 result_type = composite_pointer_type (type0, type1, op0, op1,
3483 if (TREE_CODE (orig_op0) == STRING_CST
3484 || TREE_CODE (orig_op1) == STRING_CST)
3485 warning (OPT_Wstring_literal_comparison,
3486 "comparison with string literal");
3488 build_type = boolean_type_node;
3489 if ((code0 == INTEGER_TYPE || code0 == REAL_TYPE)
3490 && (code1 == INTEGER_TYPE || code1 == REAL_TYPE))
3492 else if (code0 == POINTER_TYPE && code1 == POINTER_TYPE)
3493 result_type = composite_pointer_type (type0, type1, op0, op1,
3495 else if (code0 == POINTER_TYPE && TREE_CODE (op1) == INTEGER_CST
3496 && integer_zerop (op1))
3497 result_type = type0;
3498 else if (code1 == POINTER_TYPE && TREE_CODE (op0) == INTEGER_CST
3499 && integer_zerop (op0))
3500 result_type = type1;
3501 else if (code0 == POINTER_TYPE && code1 == INTEGER_TYPE)
3503 result_type = type0;
3504 pedwarn ("ISO C++ forbids comparison between pointer and integer");
3506 else if (code0 == INTEGER_TYPE && code1 == POINTER_TYPE)
3508 result_type = type1;
3509 pedwarn ("ISO C++ forbids comparison between pointer and integer");
3513 case UNORDERED_EXPR:
3520 build_type = integer_type_node;
3521 if (code0 != REAL_TYPE || code1 != REAL_TYPE)
3523 error ("unordered comparison on non-floating point argument");
3524 return error_mark_node;
3533 if (((code0 == INTEGER_TYPE || code0 == REAL_TYPE || code0 == COMPLEX_TYPE)
3534 && (code1 == INTEGER_TYPE || code1 == REAL_TYPE
3535 || code1 == COMPLEX_TYPE)))
3536 arithmetic_types_p = 1;
3539 arithmetic_types_p = 0;
3540 /* Vector arithmetic is only allowed when both sides are vectors. */
3541 if (code0 == VECTOR_TYPE && code1 == VECTOR_TYPE)
3543 if (!tree_int_cst_equal (TYPE_SIZE (type0), TYPE_SIZE (type1))
3544 || !same_scalar_type_ignoring_signedness (TREE_TYPE (type0),
3547 binary_op_error (code);
3548 return error_mark_node;
3550 arithmetic_types_p = 1;
3553 /* Determine the RESULT_TYPE, if it is not already known. */
3555 && arithmetic_types_p
3556 && (shorten || common || short_compare))
3557 result_type = common_type (type0, type1);
3561 error ("invalid operands of types %qT and %qT to binary %qO",
3562 TREE_TYPE (orig_op0), TREE_TYPE (orig_op1), code);
3563 return error_mark_node;
3566 /* If we're in a template, the only thing we need to know is the
3568 if (processing_template_decl)
3569 return build2 (resultcode,
3570 build_type ? build_type : result_type,
3573 if (arithmetic_types_p)
3575 int none_complex = (code0 != COMPLEX_TYPE && code1 != COMPLEX_TYPE);
3577 /* For certain operations (which identify themselves by shorten != 0)
3578 if both args were extended from the same smaller type,
3579 do the arithmetic in that type and then extend.
3581 shorten !=0 and !=1 indicates a bitwise operation.
3582 For them, this optimization is safe only if
3583 both args are zero-extended or both are sign-extended.
3584 Otherwise, we might change the result.
3585 Eg, (short)-1 | (unsigned short)-1 is (int)-1
3586 but calculated in (unsigned short) it would be (unsigned short)-1. */
3588 if (shorten && none_complex)
3590 int unsigned0, unsigned1;
3591 tree arg0 = get_narrower (op0, &unsigned0);
3592 tree arg1 = get_narrower (op1, &unsigned1);
3593 /* UNS is 1 if the operation to be done is an unsigned one. */
3594 int uns = TYPE_UNSIGNED (result_type);
3597 final_type = result_type;
3599 /* Handle the case that OP0 does not *contain* a conversion
3600 but it *requires* conversion to FINAL_TYPE. */
3602 if (op0 == arg0 && TREE_TYPE (op0) != final_type)
3603 unsigned0 = TYPE_UNSIGNED (TREE_TYPE (op0));
3604 if (op1 == arg1 && TREE_TYPE (op1) != final_type)
3605 unsigned1 = TYPE_UNSIGNED (TREE_TYPE (op1));
3607 /* Now UNSIGNED0 is 1 if ARG0 zero-extends to FINAL_TYPE. */
3609 /* For bitwise operations, signedness of nominal type
3610 does not matter. Consider only how operands were extended. */
3614 /* Note that in all three cases below we refrain from optimizing
3615 an unsigned operation on sign-extended args.
3616 That would not be valid. */
3618 /* Both args variable: if both extended in same way
3619 from same width, do it in that width.
3620 Do it unsigned if args were zero-extended. */
3621 if ((TYPE_PRECISION (TREE_TYPE (arg0))
3622 < TYPE_PRECISION (result_type))
3623 && (TYPE_PRECISION (TREE_TYPE (arg1))
3624 == TYPE_PRECISION (TREE_TYPE (arg0)))
3625 && unsigned0 == unsigned1
3626 && (unsigned0 || !uns))
3627 result_type = c_common_signed_or_unsigned_type
3628 (unsigned0, common_type (TREE_TYPE (arg0), TREE_TYPE (arg1)));
3629 else if (TREE_CODE (arg0) == INTEGER_CST
3630 && (unsigned1 || !uns)
3631 && (TYPE_PRECISION (TREE_TYPE (arg1))
3632 < TYPE_PRECISION (result_type))
3633 && (type = c_common_signed_or_unsigned_type
3634 (unsigned1, TREE_TYPE (arg1)),
3635 int_fits_type_p (arg0, type)))
3637 else if (TREE_CODE (arg1) == INTEGER_CST
3638 && (unsigned0 || !uns)
3639 && (TYPE_PRECISION (TREE_TYPE (arg0))
3640 < TYPE_PRECISION (result_type))
3641 && (type = c_common_signed_or_unsigned_type
3642 (unsigned0, TREE_TYPE (arg0)),
3643 int_fits_type_p (arg1, type)))
3647 /* Shifts can be shortened if shifting right. */
3652 tree arg0 = get_narrower (op0, &unsigned_arg);
3654 final_type = result_type;
3656 if (arg0 == op0 && final_type == TREE_TYPE (op0))
3657 unsigned_arg = TYPE_UNSIGNED (TREE_TYPE (op0));
3659 if (TYPE_PRECISION (TREE_TYPE (arg0)) < TYPE_PRECISION (result_type)
3660 /* We can shorten only if the shift count is less than the
3661 number of bits in the smaller type size. */
3662 && compare_tree_int (op1, TYPE_PRECISION (TREE_TYPE (arg0))) < 0
3663 /* If arg is sign-extended and then unsigned-shifted,
3664 we can simulate this with a signed shift in arg's type
3665 only if the extended result is at least twice as wide
3666 as the arg. Otherwise, the shift could use up all the
3667 ones made by sign-extension and bring in zeros.
3668 We can't optimize that case at all, but in most machines
3669 it never happens because available widths are 2**N. */
3670 && (!TYPE_UNSIGNED (final_type)
3672 || (((unsigned) 2 * TYPE_PRECISION (TREE_TYPE (arg0)))
3673 <= TYPE_PRECISION (result_type))))
3675 /* Do an unsigned shift if the operand was zero-extended. */
3677 = c_common_signed_or_unsigned_type (unsigned_arg,
3679 /* Convert value-to-be-shifted to that type. */
3680 if (TREE_TYPE (op0) != result_type)
3681 op0 = cp_convert (result_type, op0);
3686 /* Comparison operations are shortened too but differently.
3687 They identify themselves by setting short_compare = 1. */
3691 /* Don't write &op0, etc., because that would prevent op0
3692 from being kept in a register.
3693 Instead, make copies of the our local variables and
3694 pass the copies by reference, then copy them back afterward. */
3695 tree xop0 = op0, xop1 = op1, xresult_type = result_type;
3696 enum tree_code xresultcode = resultcode;
3698 = shorten_compare (&xop0, &xop1, &xresult_type, &xresultcode);
3700 return cp_convert (boolean_type_node, val);
3701 op0 = xop0, op1 = xop1;
3703 resultcode = xresultcode;
3706 if ((short_compare || code == MIN_EXPR || code == MAX_EXPR)
3707 && warn_sign_compare
3708 /* Do not warn until the template is instantiated; we cannot
3709 bound the ranges of the arguments until that point. */
3710 && !processing_template_decl)
3712 int op0_signed = !TYPE_UNSIGNED (TREE_TYPE (orig_op0));
3713 int op1_signed = !TYPE_UNSIGNED (TREE_TYPE (orig_op1));
3715 int unsignedp0, unsignedp1;
3716 tree primop0 = get_narrower (op0, &unsignedp0);
3717 tree primop1 = get_narrower (op1, &unsignedp1);
3719 /* Check for comparison of different enum types. */
3720 if (TREE_CODE (TREE_TYPE (orig_op0)) == ENUMERAL_TYPE
3721 && TREE_CODE (TREE_TYPE (orig_op1)) == ENUMERAL_TYPE
3722 && TYPE_MAIN_VARIANT (TREE_TYPE (orig_op0))
3723 != TYPE_MAIN_VARIANT (TREE_TYPE (orig_op1)))
3725 warning (0, "comparison between types %q#T and %q#T",
3726 TREE_TYPE (orig_op0), TREE_TYPE (orig_op1));
3729 /* Give warnings for comparisons between signed and unsigned
3730 quantities that may fail. */
3731 /* Do the checking based on the original operand trees, so that
3732 casts will be considered, but default promotions won't be. */
3734 /* Do not warn if the comparison is being done in a signed type,
3735 since the signed type will only be chosen if it can represent
3736 all the values of the unsigned type. */
3737 if (!TYPE_UNSIGNED (result_type))
3739 /* Do not warn if both operands are unsigned. */
3740 else if (op0_signed == op1_signed)
3742 /* Do not warn if the signed quantity is an unsuffixed
3743 integer literal (or some static constant expression
3744 involving such literals or a conditional expression
3745 involving such literals) and it is non-negative. */
3746 else if ((op0_signed && tree_expr_nonnegative_p (orig_op0))
3747 || (op1_signed && tree_expr_nonnegative_p (orig_op1)))
3749 /* Do not warn if the comparison is an equality operation,
3750 the unsigned quantity is an integral constant and it does
3751 not use the most significant bit of result_type. */
3752 else if ((resultcode == EQ_EXPR || resultcode == NE_EXPR)
3753 && ((op0_signed && TREE_CODE (orig_op1) == INTEGER_CST
3754 && int_fits_type_p (orig_op1, c_common_signed_type
3756 || (op1_signed && TREE_CODE (orig_op0) == INTEGER_CST
3757 && int_fits_type_p (orig_op0, c_common_signed_type
3761 warning (0, "comparison between signed and unsigned integer expressions");
3763 /* Warn if two unsigned values are being compared in a size
3764 larger than their original size, and one (and only one) is the
3765 result of a `~' operator. This comparison will always fail.
3767 Also warn if one operand is a constant, and the constant does not
3768 have all bits set that are set in the ~ operand when it is
3771 if ((TREE_CODE (primop0) == BIT_NOT_EXPR)
3772 ^ (TREE_CODE (primop1) == BIT_NOT_EXPR))
3774 if (TREE_CODE (primop0) == BIT_NOT_EXPR)
3775 primop0 = get_narrower (TREE_OPERAND (op0, 0), &unsignedp0);
3776 if (TREE_CODE (primop1) == BIT_NOT_EXPR)
3777 primop1 = get_narrower (TREE_OPERAND (op1, 0), &unsignedp1);
3779 if (host_integerp (primop0, 0) || host_integerp (primop1, 0))
3782 HOST_WIDE_INT constant, mask;
3786 if (host_integerp (primop0, 0))
3789 unsignedp = unsignedp1;
3790 constant = tree_low_cst (primop0, 0);
3795 unsignedp = unsignedp0;
3796 constant = tree_low_cst (primop1, 0);
3799 bits = TYPE_PRECISION (TREE_TYPE (primop));
3800 if (bits < TYPE_PRECISION (result_type)
3801 && bits < HOST_BITS_PER_LONG && unsignedp)
3803 mask = (~ (HOST_WIDE_INT) 0) << bits;
3804 if ((mask & constant) != mask)
3805 warning (0, "comparison of promoted ~unsigned with constant");
3808 else if (unsignedp0 && unsignedp1
3809 && (TYPE_PRECISION (TREE_TYPE (primop0))
3810 < TYPE_PRECISION (result_type))
3811 && (TYPE_PRECISION (TREE_TYPE (primop1))
3812 < TYPE_PRECISION (result_type)))
3813 warning (0, "comparison of promoted ~unsigned with unsigned");
3818 /* If CONVERTED is zero, both args will be converted to type RESULT_TYPE.
3819 Then the expression will be built.
3820 It will be given type FINAL_TYPE if that is nonzero;
3821 otherwise, it will be given type RESULT_TYPE. */
3823 /* Issue warnings about peculiar, but valid, uses of NULL. */
3824 if (/* It's reasonable to use pointer values as operands of &&
3825 and ||, so NULL is no exception. */
3826 !(code == TRUTH_ANDIF_EXPR || code == TRUTH_ORIF_EXPR)
3827 && (/* If OP0 is NULL and OP1 is not a pointer, or vice versa. */
3828 (orig_op0 == null_node
3829 && TREE_CODE (TREE_TYPE (op1)) != POINTER_TYPE)
3830 /* Or vice versa. */
3831 || (orig_op1 == null_node
3832 && TREE_CODE (TREE_TYPE (op0)) != POINTER_TYPE)
3833 /* Or, both are NULL and the operation was not a comparison. */
3834 || (orig_op0 == null_node && orig_op1 == null_node
3835 && code != EQ_EXPR && code != NE_EXPR)))
3836 /* Some sort of arithmetic operation involving NULL was
3837 performed. Note that pointer-difference and pointer-addition
3838 have already been handled above, and so we don't end up here in
3840 warning (0, "NULL used in arithmetic");
3844 if (TREE_TYPE (op0) != result_type)
3845 op0 = cp_convert (result_type, op0);
3846 if (TREE_TYPE (op1) != result_type)
3847 op1 = cp_convert (result_type, op1);
3849 if (op0 == error_mark_node || op1 == error_mark_node)
3850 return error_mark_node;
3853 if (build_type == NULL_TREE)
3854 build_type = result_type;
3856 result = build2 (resultcode, build_type, op0, op1);
3857 result = fold_if_not_in_template (result);
3858 if (final_type != 0)
3859 result = cp_convert (final_type, result);
3863 /* Return a tree for the sum or difference (RESULTCODE says which)
3864 of pointer PTROP and integer INTOP. */
3867 cp_pointer_int_sum (enum tree_code resultcode, tree ptrop, tree intop)
3869 tree res_type = TREE_TYPE (ptrop);
3871 /* pointer_int_sum() uses size_in_bytes() on the TREE_TYPE(res_type)
3872 in certain circumstance (when it's valid to do so). So we need
3873 to make sure it's complete. We don't need to check here, if we
3874 can actually complete it at all, as those checks will be done in
3875 pointer_int_sum() anyway. */
3876 complete_type (TREE_TYPE (res_type));
3878 return pointer_int_sum (resultcode, ptrop,
3879 fold_if_not_in_template (intop));
3882 /* Return a tree for the difference of pointers OP0 and OP1.
3883 The resulting tree has type int. */
3886 pointer_diff (tree op0, tree op1, tree ptrtype)
3889 tree restype = ptrdiff_type_node;
3890 tree target_type = TREE_TYPE (ptrtype);
3892 if (!complete_type_or_else (target_type, NULL_TREE))
3893 return error_mark_node;
3895 if (pedantic || warn_pointer_arith)
3897 if (TREE_CODE (target_type) == VOID_TYPE)
3898 pedwarn ("ISO C++ forbids using pointer of type %<void *%> in subtraction");
3899 if (TREE_CODE (target_type) == FUNCTION_TYPE)
3900 pedwarn ("ISO C++ forbids using pointer to a function in subtraction");
3901 if (TREE_CODE (target_type) == METHOD_TYPE)
3902 pedwarn ("ISO C++ forbids using pointer to a method in subtraction");
3905 /* First do the subtraction as integers;
3906 then drop through to build the divide operator. */
3908 op0 = cp_build_binary_op (MINUS_EXPR,
3909 cp_convert (restype, op0),
3910 cp_convert (restype, op1));
3912 /* This generates an error if op1 is a pointer to an incomplete type. */
3913 if (!COMPLETE_TYPE_P (TREE_TYPE (TREE_TYPE (op1))))
3914 error ("invalid use of a pointer to an incomplete type in pointer arithmetic");
3916 op1 = (TYPE_PTROB_P (ptrtype)
3917 ? size_in_bytes (target_type)
3918 : integer_one_node);
3920 /* Do the division. */
3922 result = build2 (EXACT_DIV_EXPR, restype, op0, cp_convert (restype, op1));
3923 return fold_if_not_in_template (result);
3926 /* Construct and perhaps optimize a tree representation
3927 for a unary operation. CODE, a tree_code, specifies the operation
3928 and XARG is the operand. */
3931 build_x_unary_op (enum tree_code code, tree xarg)
3933 tree orig_expr = xarg;
3937 if (processing_template_decl)
3939 if (type_dependent_expression_p (xarg))
3940 return build_min_nt (code, xarg, NULL_TREE);
3942 xarg = build_non_dependent_expr (xarg);
3947 /* [expr.unary.op] says:
3949 The address of an object of incomplete type can be taken.
3951 (And is just the ordinary address operator, not an overloaded
3952 "operator &".) However, if the type is a template
3953 specialization, we must complete the type at this point so that
3954 an overloaded "operator &" will be available if required. */
3955 if (code == ADDR_EXPR
3956 && TREE_CODE (xarg) != TEMPLATE_ID_EXPR
3957 && ((CLASS_TYPE_P (TREE_TYPE (xarg))
3958 && !COMPLETE_TYPE_P (complete_type (TREE_TYPE (xarg))))
3959 || (TREE_CODE (xarg) == OFFSET_REF)))
3960 /* Don't look for a function. */;
3962 exp = build_new_op (code, LOOKUP_NORMAL, xarg, NULL_TREE, NULL_TREE,
3963 /*overloaded_p=*/NULL);
3964 if (!exp && code == ADDR_EXPR)
3966 /* A pointer to member-function can be formed only by saying
3968 if (!flag_ms_extensions && TREE_CODE (TREE_TYPE (xarg)) == METHOD_TYPE
3969 && (TREE_CODE (xarg) != OFFSET_REF || !PTRMEM_OK_P (xarg)))
3971 if (TREE_CODE (xarg) != OFFSET_REF
3972 || !TYPE_P (TREE_OPERAND (xarg, 0)))
3974 error ("invalid use of %qE to form a pointer-to-member-function",
3976 if (TREE_CODE (xarg) != OFFSET_REF)
3977 inform (" a qualified-id is required");
3978 return error_mark_node;
3982 error ("parentheses around %qE cannot be used to form a"
3983 " pointer-to-member-function",
3985 PTRMEM_OK_P (xarg) = 1;
3989 if (TREE_CODE (xarg) == OFFSET_REF)
3991 ptrmem = PTRMEM_OK_P (xarg);
3993 if (!ptrmem && !flag_ms_extensions
3994 && TREE_CODE (TREE_TYPE (TREE_OPERAND (xarg, 1))) == METHOD_TYPE)
3996 /* A single non-static member, make sure we don't allow a
3997 pointer-to-member. */
3998 xarg = build2 (OFFSET_REF, TREE_TYPE (xarg),
3999 TREE_OPERAND (xarg, 0),
4000 ovl_cons (TREE_OPERAND (xarg, 1), NULL_TREE));
4001 PTRMEM_OK_P (xarg) = ptrmem;
4004 else if (TREE_CODE (xarg) == TARGET_EXPR)
4005 warning (0, "taking address of temporary");
4006 exp = build_unary_op (ADDR_EXPR, xarg, 0);
4009 if (processing_template_decl && exp != error_mark_node)
4010 exp = build_min_non_dep (code, exp, orig_expr,
4011 /*For {PRE,POST}{INC,DEC}REMENT_EXPR*/NULL_TREE);
4012 if (TREE_CODE (exp) == ADDR_EXPR)
4013 PTRMEM_OK_P (exp) = ptrmem;
4017 /* Like c_common_truthvalue_conversion, but handle pointer-to-member
4018 constants, where a null value is represented by an INTEGER_CST of
4022 cp_truthvalue_conversion (tree expr)
4024 tree type = TREE_TYPE (expr);
4025 if (TYPE_PTRMEM_P (type))
4026 return build_binary_op (NE_EXPR, expr, integer_zero_node, 1);
4028 return c_common_truthvalue_conversion (expr);
4031 /* Just like cp_truthvalue_conversion, but we want a CLEANUP_POINT_EXPR. */
4034 condition_conversion (tree expr)
4037 if (processing_template_decl)
4039 t = perform_implicit_conversion (boolean_type_node, expr);
4040 t = fold_build_cleanup_point_expr (boolean_type_node, t);
4044 /* Return an ADDR_EXPR giving the address of T. This function
4045 attempts no optimizations or simplifications; it is a low-level
4049 build_address (tree t)
4053 if (error_operand_p (t) || !cxx_mark_addressable (t))
4054 return error_mark_node;
4056 addr = build1 (ADDR_EXPR, build_pointer_type (TREE_TYPE (t)), t);
4061 /* Return a NOP_EXPR converting EXPR to TYPE. */
4064 build_nop (tree type, tree expr)
4066 if (type == error_mark_node || error_operand_p (expr))
4068 return build1 (NOP_EXPR, type, expr);
4071 /* C++: Must handle pointers to members.
4073 Perhaps type instantiation should be extended to handle conversion
4074 from aggregates to types we don't yet know we want? (Or are those
4075 cases typically errors which should be reported?)
4077 NOCONVERT nonzero suppresses the default promotions
4078 (such as from short to int). */
4081 build_unary_op (enum tree_code code, tree xarg, int noconvert)
4083 /* No default_conversion here. It causes trouble for ADDR_EXPR. */
4086 const char *errstring = NULL;
4088 const char *invalid_op_diag;
4090 if (arg == error_mark_node)
4091 return error_mark_node;
4093 if ((invalid_op_diag
4094 = targetm.invalid_unary_op ((code == UNARY_PLUS_EXPR
4099 error (invalid_op_diag);
4100 return error_mark_node;
4105 case UNARY_PLUS_EXPR:
4108 int flags = WANT_ARITH | WANT_ENUM;
4109 /* Unary plus (but not unary minus) is allowed on pointers. */
4110 if (code == UNARY_PLUS_EXPR)
4111 flags |= WANT_POINTER;
4112 arg = build_expr_type_conversion (flags, arg, true);
4114 errstring = (code == NEGATE_EXPR
4115 ? "wrong type argument to unary minus"
4116 : "wrong type argument to unary plus");
4119 if (!noconvert && CP_INTEGRAL_TYPE_P (TREE_TYPE (arg)))
4120 arg = perform_integral_promotions (arg);
4122 /* Make sure the result is not an lvalue: a unary plus or minus
4123 expression is always a rvalue. */
4130 if (TREE_CODE (TREE_TYPE (arg)) == COMPLEX_TYPE)
4134 arg = default_conversion (arg);
4136 else if (!(arg = build_expr_type_conversion (WANT_INT | WANT_ENUM
4139 errstring = "wrong type argument to bit-complement";
4140 else if (!noconvert && CP_INTEGRAL_TYPE_P (TREE_TYPE (arg)))
4141 arg = perform_integral_promotions (arg);
4145 if (!(arg = build_expr_type_conversion (WANT_ARITH | WANT_ENUM, arg, true)))
4146 errstring = "wrong type argument to abs";
4147 else if (!noconvert)
4148 arg = default_conversion (arg);
4152 /* Conjugating a real value is a no-op, but allow it anyway. */
4153 if (!(arg = build_expr_type_conversion (WANT_ARITH | WANT_ENUM, arg, true)))
4154 errstring = "wrong type argument to conjugation";
4155 else if (!noconvert)
4156 arg = default_conversion (arg);
4159 case TRUTH_NOT_EXPR:
4160 arg = perform_implicit_conversion (boolean_type_node, arg);
4161 val = invert_truthvalue (arg);
4162 if (arg != error_mark_node)
4164 errstring = "in argument to unary !";
4171 if (TREE_CODE (arg) == COMPLEX_CST)
4172 return TREE_REALPART (arg);
4173 else if (TREE_CODE (TREE_TYPE (arg)) == COMPLEX_TYPE)
4175 arg = build1 (REALPART_EXPR, TREE_TYPE (TREE_TYPE (arg)), arg);
4176 return fold_if_not_in_template (arg);
4182 if (TREE_CODE (arg) == COMPLEX_CST)
4183 return TREE_IMAGPART (arg);
4184 else if (TREE_CODE (TREE_TYPE (arg)) == COMPLEX_TYPE)
4186 arg = build1 (IMAGPART_EXPR, TREE_TYPE (TREE_TYPE (arg)), arg);
4187 return fold_if_not_in_template (arg);
4190 return cp_convert (TREE_TYPE (arg), integer_zero_node);
4192 case PREINCREMENT_EXPR:
4193 case POSTINCREMENT_EXPR:
4194 case PREDECREMENT_EXPR:
4195 case POSTDECREMENT_EXPR:
4196 /* Handle complex lvalues (when permitted)
4197 by reduction to simpler cases. */
4199 val = unary_complex_lvalue (code, arg);
4203 /* Increment or decrement the real part of the value,
4204 and don't change the imaginary part. */
4205 if (TREE_CODE (TREE_TYPE (arg)) == COMPLEX_TYPE)
4209 arg = stabilize_reference (arg);
4210 real = build_unary_op (REALPART_EXPR, arg, 1);
4211 imag = build_unary_op (IMAGPART_EXPR, arg, 1);
4212 return build2 (COMPLEX_EXPR, TREE_TYPE (arg),
4213 build_unary_op (code, real, 1), imag);
4216 /* Report invalid types. */
4218 if (!(arg = build_expr_type_conversion (WANT_ARITH | WANT_POINTER,
4221 if (code == PREINCREMENT_EXPR)
4222 errstring ="no pre-increment operator for type";
4223 else if (code == POSTINCREMENT_EXPR)
4224 errstring ="no post-increment operator for type";
4225 else if (code == PREDECREMENT_EXPR)
4226 errstring ="no pre-decrement operator for type";
4228 errstring ="no post-decrement operator for type";
4232 /* Report something read-only. */
4234 if (CP_TYPE_CONST_P (TREE_TYPE (arg))
4235 || TREE_READONLY (arg))
4236 readonly_error (arg, ((code == PREINCREMENT_EXPR
4237 || code == POSTINCREMENT_EXPR)
4238 ? "increment" : "decrement"),
4243 tree result_type = TREE_TYPE (arg);
4245 arg = get_unwidened (arg, 0);
4246 argtype = TREE_TYPE (arg);
4248 /* ARM $5.2.5 last annotation says this should be forbidden. */
4249 if (TREE_CODE (argtype) == ENUMERAL_TYPE)
4250 pedwarn ((code == PREINCREMENT_EXPR || code == POSTINCREMENT_EXPR)
4251 ? G_("ISO C++ forbids incrementing an enum")
4252 : G_("ISO C++ forbids decrementing an enum"));
4254 /* Compute the increment. */
4256 if (TREE_CODE (argtype) == POINTER_TYPE)
4258 tree type = complete_type (TREE_TYPE (argtype));
4260 if (!COMPLETE_OR_VOID_TYPE_P (type))
4261 error (((code == PREINCREMENT_EXPR
4262 || code == POSTINCREMENT_EXPR))
4263 ? G_("cannot increment a pointer to incomplete type %qT")
4264 : G_("cannot decrement a pointer to incomplete type %qT"),
4265 TREE_TYPE (argtype));
4266 else if ((pedantic || warn_pointer_arith)
4267 && !TYPE_PTROB_P (argtype))
4268 pedwarn ((code == PREINCREMENT_EXPR
4269 || code == POSTINCREMENT_EXPR)
4270 ? G_("ISO C++ forbids incrementing a pointer of type %qT")
4271 : G_("ISO C++ forbids decrementing a pointer of type %qT"),
4273 inc = cxx_sizeof_nowarn (TREE_TYPE (argtype));
4276 inc = integer_one_node;
4278 inc = cp_convert (argtype, inc);
4280 /* Handle incrementing a cast-expression. */
4282 switch (TREE_CODE (arg))
4287 case FIX_TRUNC_EXPR:
4289 tree incremented, modify, value, compound;
4290 if (! lvalue_p (arg) && pedantic)
4291 pedwarn ("cast to non-reference type used as lvalue");
4292 arg = stabilize_reference (arg);
4293 if (code == PREINCREMENT_EXPR || code == PREDECREMENT_EXPR)
4296 value = save_expr (arg);
4297 incremented = build2 (((code == PREINCREMENT_EXPR
4298 || code == POSTINCREMENT_EXPR)
4299 ? PLUS_EXPR : MINUS_EXPR),
4300 argtype, value, inc);
4302 modify = build_modify_expr (arg, NOP_EXPR, incremented);
4303 compound = build2 (COMPOUND_EXPR, TREE_TYPE (arg),
4306 /* Eliminate warning about unused result of + or -. */
4307 TREE_NO_WARNING (compound) = 1;
4315 /* Complain about anything else that is not a true lvalue. */
4316 if (!lvalue_or_else (arg, ((code == PREINCREMENT_EXPR
4317 || code == POSTINCREMENT_EXPR)
4318 ? lv_increment : lv_decrement)))
4319 return error_mark_node;
4321 /* Forbid using -- on `bool'. */
4322 if (same_type_p (TREE_TYPE (arg), boolean_type_node))
4324 if (code == POSTDECREMENT_EXPR || code == PREDECREMENT_EXPR)
4326 error ("invalid use of %<--%> on bool variable %qD", arg);
4327 return error_mark_node;
4329 val = boolean_increment (code, arg);
4332 val = build2 (code, TREE_TYPE (arg), arg, inc);
4334 TREE_SIDE_EFFECTS (val) = 1;
4335 return cp_convert (result_type, val);
4339 /* Note that this operation never does default_conversion
4340 regardless of NOCONVERT. */
4342 argtype = lvalue_type (arg);
4344 if (TREE_CODE (arg) == OFFSET_REF)
4347 if (TREE_CODE (argtype) == REFERENCE_TYPE)
4349 tree type = build_pointer_type (TREE_TYPE (argtype));
4350 arg = build1 (CONVERT_EXPR, type, arg);
4353 else if (pedantic && DECL_MAIN_P (arg))
4355 pedwarn ("ISO C++ forbids taking address of function %<::main%>");
4357 /* Let &* cancel out to simplify resulting code. */
4358 if (TREE_CODE (arg) == INDIRECT_REF)
4360 /* We don't need to have `current_class_ptr' wrapped in a
4361 NON_LVALUE_EXPR node. */
4362 if (arg == current_class_ref)
4363 return current_class_ptr;
4365 arg = TREE_OPERAND (arg, 0);
4366 if (TREE_CODE (TREE_TYPE (arg)) == REFERENCE_TYPE)
4368 tree type = build_pointer_type (TREE_TYPE (TREE_TYPE (arg)));
4369 arg = build1 (CONVERT_EXPR, type, arg);
4372 /* Don't let this be an lvalue. */
4377 /* Uninstantiated types are all functions. Taking the
4378 address of a function is a no-op, so just return the
4381 gcc_assert (TREE_CODE (arg) != IDENTIFIER_NODE
4382 || !IDENTIFIER_OPNAME_P (arg));
4384 if (TREE_CODE (arg) == COMPONENT_REF && type_unknown_p (arg)
4385 && !really_overloaded_fn (TREE_OPERAND (arg, 1)))
4387 /* They're trying to take the address of a unique non-static
4388 member function. This is ill-formed (except in MS-land),
4389 but let's try to DTRT.
4390 Note: We only handle unique functions here because we don't
4391 want to complain if there's a static overload; non-unique
4392 cases will be handled by instantiate_type. But we need to
4393 handle this case here to allow casts on the resulting PMF.
4394 We could defer this in non-MS mode, but it's easier to give
4395 a useful error here. */
4397 /* Inside constant member functions, the `this' pointer
4398 contains an extra const qualifier. TYPE_MAIN_VARIANT
4399 is used here to remove this const from the diagnostics
4400 and the created OFFSET_REF. */
4401 tree base = TYPE_MAIN_VARIANT (TREE_TYPE (TREE_OPERAND (arg, 0)));
4402 tree fn = get_first_fn (TREE_OPERAND (arg, 1));
4405 if (! flag_ms_extensions)
4407 tree name = DECL_NAME (fn);
4408 if (current_class_type
4409 && TREE_OPERAND (arg, 0) == current_class_ref)
4410 /* An expression like &memfn. */
4411 pedwarn ("ISO C++ forbids taking the address of an unqualified"
4412 " or parenthesized non-static member function to form"
4413 " a pointer to member function. Say %<&%T::%D%>",
4416 pedwarn ("ISO C++ forbids taking the address of a bound member"
4417 " function to form a pointer to member function."
4421 arg = build_offset_ref (base, fn, /*address_p=*/true);
4425 if (type_unknown_p (arg))
4426 return build1 (ADDR_EXPR, unknown_type_node, arg);
4428 /* Handle complex lvalues (when permitted)
4429 by reduction to simpler cases. */
4430 val = unary_complex_lvalue (code, arg);
4434 switch (TREE_CODE (arg))
4439 case FIX_TRUNC_EXPR:
4440 if (! lvalue_p (arg) && pedantic)
4441 pedwarn ("ISO C++ forbids taking the address of a cast to a non-lvalue expression");
4445 arg = BASELINK_FUNCTIONS (arg);
4449 arg = OVL_CURRENT (arg);
4453 /* Turn a reference to a non-static data member into a
4454 pointer-to-member. */
4459 if (!PTRMEM_OK_P (arg))
4460 return build_unary_op (code, arg, 0);
4462 t = TREE_OPERAND (arg, 1);
4463 if (TREE_CODE (TREE_TYPE (t)) == REFERENCE_TYPE)
4465 error ("cannot create pointer to reference member %qD", t);
4466 return error_mark_node;
4469 type = build_ptrmem_type (context_for_name_lookup (t),
4471 t = make_ptrmem_cst (type, TREE_OPERAND (arg, 1));
4479 /* Anything not already handled and not a true memory reference
4481 if (TREE_CODE (argtype) != FUNCTION_TYPE
4482 && TREE_CODE (argtype) != METHOD_TYPE
4483 && TREE_CODE (arg) != OFFSET_REF
4484 && !lvalue_or_else (arg, lv_addressof))
4485 return error_mark_node;
4487 if (argtype != error_mark_node)
4488 argtype = build_pointer_type (argtype);
4490 /* In a template, we are processing a non-dependent expression
4491 so we can just form an ADDR_EXPR with the correct type. */
4492 if (processing_template_decl)
4494 val = build_address (arg);
4495 if (TREE_CODE (arg) == OFFSET_REF)
4496 PTRMEM_OK_P (val) = PTRMEM_OK_P (arg);
4500 if (TREE_CODE (arg) != COMPONENT_REF)
4502 val = build_address (arg);
4503 if (TREE_CODE (arg) == OFFSET_REF)
4504 PTRMEM_OK_P (val) = PTRMEM_OK_P (arg);
4506 else if (TREE_CODE (TREE_OPERAND (arg, 1)) == BASELINK)
4508 tree fn = BASELINK_FUNCTIONS (TREE_OPERAND (arg, 1));
4510 /* We can only get here with a single static member
4512 gcc_assert (TREE_CODE (fn) == FUNCTION_DECL
4513 && DECL_STATIC_FUNCTION_P (fn));
4515 val = build_address (fn);
4516 if (TREE_SIDE_EFFECTS (TREE_OPERAND (arg, 0)))
4517 /* Do not lose object's side effects. */
4518 val = build2 (COMPOUND_EXPR, TREE_TYPE (val),
4519 TREE_OPERAND (arg, 0), val);
4521 else if (DECL_C_BIT_FIELD (TREE_OPERAND (arg, 1)))
4523 error ("attempt to take address of bit-field structure member %qD",
4524 TREE_OPERAND (arg, 1));
4525 return error_mark_node;
4529 tree object = TREE_OPERAND (arg, 0);
4530 tree field = TREE_OPERAND (arg, 1);
4531 gcc_assert (same_type_ignoring_top_level_qualifiers_p
4532 (TREE_TYPE (object), decl_type_context (field)));
4533 val = build_address (arg);
4536 if (TREE_CODE (argtype) == POINTER_TYPE
4537 && TREE_CODE (TREE_TYPE (argtype)) == METHOD_TYPE)
4539 build_ptrmemfunc_type (argtype);
4540 val = build_ptrmemfunc (argtype, val, 0,
4541 /*c_cast_p=*/false);
4553 argtype = TREE_TYPE (arg);
4554 return fold_if_not_in_template (build1 (code, argtype, arg));
4557 error ("%s", errstring);
4558 return error_mark_node;
4561 /* Apply unary lvalue-demanding operator CODE to the expression ARG
4562 for certain kinds of expressions which are not really lvalues
4563 but which we can accept as lvalues.
4565 If ARG is not a kind of expression we can handle, return
4569 unary_complex_lvalue (enum tree_code code, tree arg)
4571 /* Inside a template, making these kinds of adjustments is
4572 pointless; we are only concerned with the type of the
4574 if (processing_template_decl)
4577 /* Handle (a, b) used as an "lvalue". */
4578 if (TREE_CODE (arg) == COMPOUND_EXPR)
4580 tree real_result = build_unary_op (code, TREE_OPERAND (arg, 1), 0);
4581 return build2 (COMPOUND_EXPR, TREE_TYPE (real_result),
4582 TREE_OPERAND (arg, 0), real_result);
4585 /* Handle (a ? b : c) used as an "lvalue". */
4586 if (TREE_CODE (arg) == COND_EXPR
4587 || TREE_CODE (arg) == MIN_EXPR || TREE_CODE (arg) == MAX_EXPR)
4588 return rationalize_conditional_expr (code, arg);
4590 /* Handle (a = b), (++a), and (--a) used as an "lvalue". */
4591 if (TREE_CODE (arg) == MODIFY_EXPR
4592 || TREE_CODE (arg) == PREINCREMENT_EXPR
4593 || TREE_CODE (arg) == PREDECREMENT_EXPR)
4595 tree lvalue = TREE_OPERAND (arg, 0);
4596 if (TREE_SIDE_EFFECTS (lvalue))
4598 lvalue = stabilize_reference (lvalue);
4599 arg = build2 (TREE_CODE (arg), TREE_TYPE (arg),
4600 lvalue, TREE_OPERAND (arg, 1));
4602 return unary_complex_lvalue
4603 (code, build2 (COMPOUND_EXPR, TREE_TYPE (lvalue), arg, lvalue));
4606 if (code != ADDR_EXPR)
4609 /* Handle (a = b) used as an "lvalue" for `&'. */
4610 if (TREE_CODE (arg) == MODIFY_EXPR
4611 || TREE_CODE (arg) == INIT_EXPR)
4613 tree real_result = build_unary_op (code, TREE_OPERAND (arg, 0), 0);
4614 arg = build2 (COMPOUND_EXPR, TREE_TYPE (real_result),
4616 TREE_NO_WARNING (arg) = 1;
4620 if (TREE_CODE (TREE_TYPE (arg)) == FUNCTION_TYPE
4621 || TREE_CODE (TREE_TYPE (arg)) == METHOD_TYPE
4622 || TREE_CODE (arg) == OFFSET_REF)
4625 /* We permit compiler to make function calls returning
4626 objects of aggregate type look like lvalues. */
4630 if (TREE_CODE (targ) == SAVE_EXPR)
4631 targ = TREE_OPERAND (targ, 0);
4633 if (TREE_CODE (targ) == CALL_EXPR && IS_AGGR_TYPE (TREE_TYPE (targ)))
4635 if (TREE_CODE (arg) == SAVE_EXPR)
4638 targ = build_cplus_new (TREE_TYPE (arg), arg);
4639 return build1 (ADDR_EXPR, build_pointer_type (TREE_TYPE (arg)), targ);
4642 if (TREE_CODE (arg) == SAVE_EXPR && TREE_CODE (targ) == INDIRECT_REF)
4643 return build3 (SAVE_EXPR, build_pointer_type (TREE_TYPE (arg)),
4644 TREE_OPERAND (targ, 0), current_function_decl, NULL);
4647 /* Don't let anything else be handled specially. */
4651 /* Mark EXP saying that we need to be able to take the
4652 address of it; it should not be allocated in a register.
4653 Value is true if successful.
4655 C++: we do not allow `current_class_ptr' to be addressable. */
4658 cxx_mark_addressable (tree exp)
4663 switch (TREE_CODE (x))
4670 x = TREE_OPERAND (x, 0);
4674 if (x == current_class_ptr)
4676 error ("cannot take the address of %<this%>, which is an rvalue expression");
4677 TREE_ADDRESSABLE (x) = 1; /* so compiler doesn't die later. */
4683 /* Caller should not be trying to mark initialized
4684 constant fields addressable. */
4685 gcc_assert (DECL_LANG_SPECIFIC (x) == 0
4686 || DECL_IN_AGGR_P (x) == 0
4688 || DECL_EXTERNAL (x));
4693 if (DECL_REGISTER (x) && !TREE_ADDRESSABLE (x)
4694 && !DECL_ARTIFICIAL (x))
4696 if (TREE_CODE (x) == VAR_DECL && DECL_HARD_REGISTER (x))
4699 ("address of explicit register variable %qD requested", x);
4702 else if (extra_warnings)
4704 (OPT_Wextra, "address requested for %qD, which is declared %<register%>", x);
4706 TREE_ADDRESSABLE (x) = 1;
4710 TREE_ADDRESSABLE (x) = 1;
4714 TREE_ADDRESSABLE (x) = 1;
4718 TREE_ADDRESSABLE (x) = 1;
4719 cxx_mark_addressable (TREE_OPERAND (x, 0));
4727 /* Build and return a conditional expression IFEXP ? OP1 : OP2. */
4730 build_x_conditional_expr (tree ifexp, tree op1, tree op2)
4732 tree orig_ifexp = ifexp;
4733 tree orig_op1 = op1;
4734 tree orig_op2 = op2;
4737 if (processing_template_decl)
4739 /* The standard says that the expression is type-dependent if
4740 IFEXP is type-dependent, even though the eventual type of the
4741 expression doesn't dependent on IFEXP. */
4742 if (type_dependent_expression_p (ifexp)
4743 /* As a GNU extension, the middle operand may be omitted. */
4744 || (op1 && type_dependent_expression_p (op1))
4745 || type_dependent_expression_p (op2))
4746 return build_min_nt (COND_EXPR, ifexp, op1, op2);
4747 ifexp = build_non_dependent_expr (ifexp);
4749 op1 = build_non_dependent_expr (op1);
4750 op2 = build_non_dependent_expr (op2);
4753 expr = build_conditional_expr (ifexp, op1, op2);
4754 if (processing_template_decl && expr != error_mark_node)
4755 return build_min_non_dep (COND_EXPR, expr,
4756 orig_ifexp, orig_op1, orig_op2);
4760 /* Given a list of expressions, return a compound expression
4761 that performs them all and returns the value of the last of them. */
4763 tree build_x_compound_expr_from_list (tree list, const char *msg)
4765 tree expr = TREE_VALUE (list);
4767 if (TREE_CHAIN (list))
4770 pedwarn ("%s expression list treated as compound expression", msg);
4772 for (list = TREE_CHAIN (list); list; list = TREE_CHAIN (list))
4773 expr = build_x_compound_expr (expr, TREE_VALUE (list));
4779 /* Handle overloading of the ',' operator when needed. */
4782 build_x_compound_expr (tree op1, tree op2)
4785 tree orig_op1 = op1;
4786 tree orig_op2 = op2;
4788 if (processing_template_decl)
4790 if (type_dependent_expression_p (op1)
4791 || type_dependent_expression_p (op2))
4792 return build_min_nt (COMPOUND_EXPR, op1, op2);
4793 op1 = build_non_dependent_expr (op1);
4794 op2 = build_non_dependent_expr (op2);
4797 result = build_new_op (COMPOUND_EXPR, LOOKUP_NORMAL, op1, op2, NULL_TREE,
4798 /*overloaded_p=*/NULL);
4800 result = build_compound_expr (op1, op2);
4802 if (processing_template_decl && result != error_mark_node)
4803 return build_min_non_dep (COMPOUND_EXPR, result, orig_op1, orig_op2);
4808 /* Build a compound expression. */
4811 build_compound_expr (tree lhs, tree rhs)
4813 lhs = convert_to_void (lhs, "left-hand operand of comma");
4815 if (lhs == error_mark_node || rhs == error_mark_node)
4816 return error_mark_node;
4818 if (TREE_CODE (rhs) == TARGET_EXPR)
4820 /* If the rhs is a TARGET_EXPR, then build the compound
4821 expression inside the target_expr's initializer. This
4822 helps the compiler to eliminate unnecessary temporaries. */
4823 tree init = TREE_OPERAND (rhs, 1);
4825 init = build2 (COMPOUND_EXPR, TREE_TYPE (init), lhs, init);
4826 TREE_OPERAND (rhs, 1) = init;
4831 return build2 (COMPOUND_EXPR, TREE_TYPE (rhs), lhs, rhs);
4834 /* Issue a diagnostic message if casting from SRC_TYPE to DEST_TYPE
4835 casts away constness. DIAG_FN gives the function to call if we
4836 need to issue a diagnostic; if it is NULL, no diagnostic will be
4837 issued. DESCRIPTION explains what operation is taking place. */
4840 check_for_casting_away_constness (tree src_type, tree dest_type,
4841 void (*diag_fn)(const char *, ...) ATTRIBUTE_GCC_CXXDIAG(1,2),
4842 const char *description)
4844 if (diag_fn && casts_away_constness (src_type, dest_type))
4845 diag_fn ("%s from type %qT to type %qT casts away constness",
4846 description, src_type, dest_type);
4849 /* Convert EXPR (an expression with pointer-to-member type) to TYPE
4850 (another pointer-to-member type in the same hierarchy) and return
4851 the converted expression. If ALLOW_INVERSE_P is permitted, a
4852 pointer-to-derived may be converted to pointer-to-base; otherwise,
4853 only the other direction is permitted. If C_CAST_P is true, this
4854 conversion is taking place as part of a C-style cast. */
4857 convert_ptrmem (tree type, tree expr, bool allow_inverse_p,
4860 if (TYPE_PTRMEM_P (type))
4864 if (TREE_CODE (expr) == PTRMEM_CST)
4865 expr = cplus_expand_constant (expr);
4866 delta = get_delta_difference (TYPE_PTRMEM_CLASS_TYPE (TREE_TYPE (expr)),
4867 TYPE_PTRMEM_CLASS_TYPE (type),
4870 if (!integer_zerop (delta))
4871 expr = cp_build_binary_op (PLUS_EXPR,
4872 build_nop (ptrdiff_type_node, expr),
4874 return build_nop (type, expr);
4877 return build_ptrmemfunc (TYPE_PTRMEMFUNC_FN_TYPE (type), expr,
4878 allow_inverse_p, c_cast_p);
4881 /* If EXPR is an INTEGER_CST and ORIG is an arithmetic constant, return
4882 a version of EXPR that has TREE_OVERFLOW and/or TREE_CONSTANT_OVERFLOW
4883 set iff they are set in ORIG. Otherwise, return EXPR unchanged. */
4886 ignore_overflows (tree expr, tree orig)
4888 if (TREE_CODE (expr) == INTEGER_CST
4889 && CONSTANT_CLASS_P (orig)
4890 && TREE_CODE (orig) != STRING_CST
4891 && (TREE_OVERFLOW (expr) != TREE_OVERFLOW (orig)
4892 || TREE_CONSTANT_OVERFLOW (expr)
4893 != TREE_CONSTANT_OVERFLOW (orig)))
4895 if (!TREE_OVERFLOW (orig) && !TREE_CONSTANT_OVERFLOW (orig))
4896 /* Ensure constant sharing. */
4897 expr = build_int_cst_wide (TREE_TYPE (expr),
4898 TREE_INT_CST_LOW (expr),
4899 TREE_INT_CST_HIGH (expr));
4902 /* Avoid clobbering a shared constant. */
4903 expr = copy_node (expr);
4904 TREE_OVERFLOW (expr) = TREE_OVERFLOW (orig);
4905 TREE_CONSTANT_OVERFLOW (expr)
4906 = TREE_CONSTANT_OVERFLOW (orig);
4912 /* Perform a static_cast from EXPR to TYPE. When C_CAST_P is true,
4913 this static_cast is being attempted as one of the possible casts
4914 allowed by a C-style cast. (In that case, accessibility of base
4915 classes is not considered, and it is OK to cast away
4916 constness.) Return the result of the cast. *VALID_P is set to
4917 indicate whether or not the cast was valid. */
4920 build_static_cast_1 (tree type, tree expr, bool c_cast_p,
4926 void (*diag_fn)(const char*, ...) ATTRIBUTE_GCC_CXXDIAG(1,2);
4929 /* Assume the cast is valid. */
4932 intype = TREE_TYPE (expr);
4934 /* Save casted types in the function's used types hash table. */
4935 used_types_insert (type);
4937 /* Determine what to do when casting away constness. */
4940 /* C-style casts are allowed to cast away constness. With
4941 WARN_CAST_QUAL, we still want to issue a warning. */
4942 diag_fn = warn_cast_qual ? warning0 : NULL;
4947 /* A static_cast may not cast away constness. */
4949 desc = "static_cast";
4952 /* [expr.static.cast]
4954 An lvalue of type "cv1 B", where B is a class type, can be cast
4955 to type "reference to cv2 D", where D is a class derived (clause
4956 _class.derived_) from B, if a valid standard conversion from
4957 "pointer to D" to "pointer to B" exists (_conv.ptr_), cv2 is the
4958 same cv-qualification as, or greater cv-qualification than, cv1,
4959 and B is not a virtual base class of D. */
4960 /* We check this case before checking the validity of "TYPE t =
4961 EXPR;" below because for this case:
4964 struct D : public B { D(const B&); };
4966 void f() { static_cast<const D&>(b); }
4968 we want to avoid constructing a new D. The standard is not
4969 completely clear about this issue, but our interpretation is
4970 consistent with other compilers. */
4971 if (TREE_CODE (type) == REFERENCE_TYPE
4972 && CLASS_TYPE_P (TREE_TYPE (type))
4973 && CLASS_TYPE_P (intype)
4974 && real_lvalue_p (expr)
4975 && DERIVED_FROM_P (intype, TREE_TYPE (type))
4976 && can_convert (build_pointer_type (TYPE_MAIN_VARIANT (intype)),
4977 build_pointer_type (TYPE_MAIN_VARIANT
4978 (TREE_TYPE (type))))
4980 || at_least_as_qualified_p (TREE_TYPE (type), intype)))
4984 /* There is a standard conversion from "D*" to "B*" even if "B"
4985 is ambiguous or inaccessible. If this is really a
4986 static_cast, then we check both for inaccessibility and
4987 ambiguity. However, if this is a static_cast being performed
4988 because the user wrote a C-style cast, then accessibility is
4990 base = lookup_base (TREE_TYPE (type), intype,
4991 c_cast_p ? ba_unique : ba_check,
4994 /* Convert from "B*" to "D*". This function will check that "B"
4995 is not a virtual base of "D". */
4996 expr = build_base_path (MINUS_EXPR, build_address (expr),
4997 base, /*nonnull=*/false);
4998 /* Convert the pointer to a reference -- but then remember that
4999 there are no expressions with reference type in C++. */
5000 return convert_from_reference (build_nop (type, expr));
5005 /* [expr.static.cast]
5007 An expression e can be explicitly converted to a type T using a
5008 static_cast of the form static_cast<T>(e) if the declaration T
5009 t(e);" is well-formed, for some invented temporary variable
5011 result = perform_direct_initialization_if_possible (type, expr,
5015 result = convert_from_reference (result);
5017 /* Ignore any integer overflow caused by the cast. */
5018 result = ignore_overflows (result, orig);
5020 /* [expr.static.cast]
5022 If T is a reference type, the result is an lvalue; otherwise,
5023 the result is an rvalue. */
5024 if (TREE_CODE (type) != REFERENCE_TYPE)
5025 result = rvalue (result);
5029 /* [expr.static.cast]
5031 Any expression can be explicitly converted to type cv void. */
5032 if (TREE_CODE (type) == VOID_TYPE)
5033 return convert_to_void (expr, /*implicit=*/NULL);
5035 /* [expr.static.cast]
5037 The inverse of any standard conversion sequence (clause _conv_),
5038 other than the lvalue-to-rvalue (_conv.lval_), array-to-pointer
5039 (_conv.array_), function-to-pointer (_conv.func_), and boolean
5040 (_conv.bool_) conversions, can be performed explicitly using
5041 static_cast subject to the restriction that the explicit
5042 conversion does not cast away constness (_expr.const.cast_), and
5043 the following additional rules for specific cases: */
5044 /* For reference, the conversions not excluded are: integral
5045 promotions, floating point promotion, integral conversions,
5046 floating point conversions, floating-integral conversions,
5047 pointer conversions, and pointer to member conversions. */
5050 A value of integral _or enumeration_ type can be explicitly
5051 converted to an enumeration type. */
5052 /* The effect of all that is that any conversion between any two
5053 types which are integral, floating, or enumeration types can be
5055 if ((INTEGRAL_TYPE_P (type) || SCALAR_FLOAT_TYPE_P (type))
5056 && (INTEGRAL_TYPE_P (intype) || SCALAR_FLOAT_TYPE_P (intype)))
5058 expr = ocp_convert (type, expr, CONV_C_CAST, LOOKUP_NORMAL);
5060 /* Ignore any integer overflow caused by the cast. */
5061 expr = ignore_overflows (expr, orig);
5065 if (TYPE_PTR_P (type) && TYPE_PTR_P (intype)
5066 && CLASS_TYPE_P (TREE_TYPE (type))
5067 && CLASS_TYPE_P (TREE_TYPE (intype))
5068 && can_convert (build_pointer_type (TYPE_MAIN_VARIANT
5069 (TREE_TYPE (intype))),
5070 build_pointer_type (TYPE_MAIN_VARIANT
5071 (TREE_TYPE (type)))))
5076 check_for_casting_away_constness (intype, type, diag_fn, desc);
5077 base = lookup_base (TREE_TYPE (type), TREE_TYPE (intype),
5078 c_cast_p ? ba_unique : ba_check,
5080 return build_base_path (MINUS_EXPR, expr, base, /*nonnull=*/false);
5083 if ((TYPE_PTRMEM_P (type) && TYPE_PTRMEM_P (intype))
5084 || (TYPE_PTRMEMFUNC_P (type) && TYPE_PTRMEMFUNC_P (intype)))
5091 c1 = TYPE_PTRMEM_CLASS_TYPE (intype);
5092 c2 = TYPE_PTRMEM_CLASS_TYPE (type);
5094 if (TYPE_PTRMEM_P (type))
5096 t1 = (build_ptrmem_type
5098 TYPE_MAIN_VARIANT (TYPE_PTRMEM_POINTED_TO_TYPE (intype))));
5099 t2 = (build_ptrmem_type
5101 TYPE_MAIN_VARIANT (TYPE_PTRMEM_POINTED_TO_TYPE (type))));
5108 if (can_convert (t1, t2))
5111 check_for_casting_away_constness (intype, type, diag_fn,
5113 return convert_ptrmem (type, expr, /*allow_inverse_p=*/1,
5118 /* [expr.static.cast]
5120 An rvalue of type "pointer to cv void" can be explicitly
5121 converted to a pointer to object type. A value of type pointer
5122 to object converted to "pointer to cv void" and back to the
5123 original pointer type will have its original value. */
5124 if (TREE_CODE (intype) == POINTER_TYPE
5125 && VOID_TYPE_P (TREE_TYPE (intype))
5126 && TYPE_PTROB_P (type))
5129 check_for_casting_away_constness (intype, type, diag_fn, desc);
5130 return build_nop (type, expr);
5134 return error_mark_node;
5137 /* Return an expression representing static_cast<TYPE>(EXPR). */
5140 build_static_cast (tree type, tree expr)
5145 if (type == error_mark_node || expr == error_mark_node)
5146 return error_mark_node;
5148 if (processing_template_decl)
5150 expr = build_min (STATIC_CAST_EXPR, type, expr);
5151 /* We don't know if it will or will not have side effects. */
5152 TREE_SIDE_EFFECTS (expr) = 1;
5153 return convert_from_reference (expr);
5156 /* build_c_cast puts on a NOP_EXPR to make the result not an lvalue.
5157 Strip such NOP_EXPRs if VALUE is being used in non-lvalue context. */
5158 if (TREE_CODE (type) != REFERENCE_TYPE
5159 && TREE_CODE (expr) == NOP_EXPR
5160 && TREE_TYPE (expr) == TREE_TYPE (TREE_OPERAND (expr, 0)))
5161 expr = TREE_OPERAND (expr, 0);
5163 result = build_static_cast_1 (type, expr, /*c_cast_p=*/false, &valid_p);
5167 error ("invalid static_cast from type %qT to type %qT",
5168 TREE_TYPE (expr), type);
5169 return error_mark_node;
5172 /* EXPR is an expression with member function or pointer-to-member
5173 function type. TYPE is a pointer type. Converting EXPR to TYPE is
5174 not permitted by ISO C++, but we accept it in some modes. If we
5175 are not in one of those modes, issue a diagnostic. Return the
5176 converted expression. */
5179 convert_member_func_to_ptr (tree type, tree expr)
5184 intype = TREE_TYPE (expr);
5185 gcc_assert (TYPE_PTRMEMFUNC_P (intype)
5186 || TREE_CODE (intype) == METHOD_TYPE);
5188 if (pedantic || warn_pmf2ptr)
5189 pedwarn ("converting from %qT to %qT", intype, type);
5191 if (TREE_CODE (intype) == METHOD_TYPE)
5192 expr = build_addr_func (expr);
5193 else if (TREE_CODE (expr) == PTRMEM_CST)
5194 expr = build_address (PTRMEM_CST_MEMBER (expr));
5197 decl = maybe_dummy_object (TYPE_PTRMEM_CLASS_TYPE (intype), 0);
5198 decl = build_address (decl);
5199 expr = get_member_function_from_ptrfunc (&decl, expr);
5202 return build_nop (type, expr);
5205 /* Return a representation for a reinterpret_cast from EXPR to TYPE.
5206 If C_CAST_P is true, this reinterpret cast is being done as part of
5207 a C-style cast. If VALID_P is non-NULL, *VALID_P is set to
5208 indicate whether or not reinterpret_cast was valid. */
5211 build_reinterpret_cast_1 (tree type, tree expr, bool c_cast_p,
5216 /* Assume the cast is invalid. */
5220 if (type == error_mark_node || error_operand_p (expr))
5221 return error_mark_node;
5223 intype = TREE_TYPE (expr);
5225 /* Save casted types in the function's used types hash table. */
5226 used_types_insert (type);
5228 /* [expr.reinterpret.cast]
5229 An lvalue expression of type T1 can be cast to the type
5230 "reference to T2" if an expression of type "pointer to T1" can be
5231 explicitly converted to the type "pointer to T2" using a
5232 reinterpret_cast. */
5233 if (TREE_CODE (type) == REFERENCE_TYPE)
5235 if (! real_lvalue_p (expr))
5237 error ("invalid cast of an rvalue expression of type "
5240 return error_mark_node;
5243 /* Warn about a reinterpret_cast from "A*" to "B&" if "A" and
5244 "B" are related class types; the reinterpret_cast does not
5245 adjust the pointer. */
5246 if (TYPE_PTR_P (intype)
5247 && (comptypes (TREE_TYPE (intype), TREE_TYPE (type),
5248 COMPARE_BASE | COMPARE_DERIVED)))
5249 warning (0, "casting %qT to %qT does not dereference pointer",
5252 expr = build_unary_op (ADDR_EXPR, expr, 0);
5253 if (expr != error_mark_node)
5254 expr = build_reinterpret_cast_1
5255 (build_pointer_type (TREE_TYPE (type)), expr, c_cast_p,
5257 if (expr != error_mark_node)
5258 expr = build_indirect_ref (expr, 0);
5262 /* As a G++ extension, we consider conversions from member
5263 functions, and pointers to member functions to
5264 pointer-to-function and pointer-to-void types. If
5265 -Wno-pmf-conversions has not been specified,
5266 convert_member_func_to_ptr will issue an error message. */
5267 if ((TYPE_PTRMEMFUNC_P (intype)
5268 || TREE_CODE (intype) == METHOD_TYPE)
5269 && TYPE_PTR_P (type)
5270 && (TREE_CODE (TREE_TYPE (type)) == FUNCTION_TYPE
5271 || VOID_TYPE_P (TREE_TYPE (type))))
5272 return convert_member_func_to_ptr (type, expr);
5274 /* If the cast is not to a reference type, the lvalue-to-rvalue,
5275 array-to-pointer, and function-to-pointer conversions are
5277 expr = decay_conversion (expr);
5279 /* build_c_cast puts on a NOP_EXPR to make the result not an lvalue.
5280 Strip such NOP_EXPRs if VALUE is being used in non-lvalue context. */
5281 if (TREE_CODE (expr) == NOP_EXPR
5282 && TREE_TYPE (expr) == TREE_TYPE (TREE_OPERAND (expr, 0)))
5283 expr = TREE_OPERAND (expr, 0);
5285 if (error_operand_p (expr))
5286 return error_mark_node;
5288 intype = TREE_TYPE (expr);
5290 /* [expr.reinterpret.cast]
5291 A pointer can be converted to any integral type large enough to
5293 if (CP_INTEGRAL_TYPE_P (type) && TYPE_PTR_P (intype))
5295 if (TYPE_PRECISION (type) < TYPE_PRECISION (intype))
5296 pedwarn ("cast from %qT to %qT loses precision",
5299 /* [expr.reinterpret.cast]
5300 A value of integral or enumeration type can be explicitly
5301 converted to a pointer. */
5302 else if (TYPE_PTR_P (type) && INTEGRAL_OR_ENUMERATION_TYPE_P (intype))
5305 else if ((TYPE_PTRFN_P (type) && TYPE_PTRFN_P (intype))
5306 || (TYPE_PTRMEMFUNC_P (type) && TYPE_PTRMEMFUNC_P (intype)))
5307 return fold_if_not_in_template (build_nop (type, expr));
5308 else if ((TYPE_PTRMEM_P (type) && TYPE_PTRMEM_P (intype))
5309 || (TYPE_PTROBV_P (type) && TYPE_PTROBV_P (intype)))
5314 check_for_casting_away_constness (intype, type, error,
5315 "reinterpret_cast");
5316 /* Warn about possible alignment problems. */
5317 if (STRICT_ALIGNMENT && warn_cast_align
5318 && !VOID_TYPE_P (type)
5319 && TREE_CODE (TREE_TYPE (intype)) != FUNCTION_TYPE
5320 && COMPLETE_TYPE_P (TREE_TYPE (type))
5321 && COMPLETE_TYPE_P (TREE_TYPE (intype))
5322 && TYPE_ALIGN (TREE_TYPE (type)) > TYPE_ALIGN (TREE_TYPE (intype)))
5323 warning (0, "cast from %qT to %qT increases required alignment of "
5327 /* We need to strip nops here, because the frontend likes to
5328 create (int *)&a for array-to-pointer decay, instead of &a[0]. */
5330 strict_aliasing_warning (intype, type, sexpr);
5332 return fold_if_not_in_template (build_nop (type, expr));
5334 else if ((TYPE_PTRFN_P (type) && TYPE_PTROBV_P (intype))
5335 || (TYPE_PTRFN_P (intype) && TYPE_PTROBV_P (type)))
5338 /* Only issue a warning, as we have always supported this
5339 where possible, and it is necessary in some cases. DR 195
5340 addresses this issue, but as of 2004/10/26 is still in
5342 warning (0, "ISO C++ forbids casting between pointer-to-function and pointer-to-object");
5343 return fold_if_not_in_template (build_nop (type, expr));
5345 else if (TREE_CODE (type) == VECTOR_TYPE)
5346 return fold_if_not_in_template (convert_to_vector (type, expr));
5347 else if (TREE_CODE (intype) == VECTOR_TYPE)
5348 return fold_if_not_in_template (convert_to_integer (type, expr));
5353 error ("invalid cast from type %qT to type %qT", intype, type);
5354 return error_mark_node;
5357 return cp_convert (type, expr);
5361 build_reinterpret_cast (tree type, tree expr)
5363 if (type == error_mark_node || expr == error_mark_node)
5364 return error_mark_node;
5366 if (processing_template_decl)
5368 tree t = build_min (REINTERPRET_CAST_EXPR, type, expr);
5370 if (!TREE_SIDE_EFFECTS (t)
5371 && type_dependent_expression_p (expr))
5372 /* There might turn out to be side effects inside expr. */
5373 TREE_SIDE_EFFECTS (t) = 1;
5374 return convert_from_reference (t);
5377 return build_reinterpret_cast_1 (type, expr, /*c_cast_p=*/false,
5381 /* Perform a const_cast from EXPR to TYPE. If the cast is valid,
5382 return an appropriate expression. Otherwise, return
5383 error_mark_node. If the cast is not valid, and COMPLAIN is true,
5384 then a diagnostic will be issued. If VALID_P is non-NULL, we are
5385 performing a C-style cast, its value upon return will indicate
5386 whether or not the conversion succeeded. */
5389 build_const_cast_1 (tree dst_type, tree expr, bool complain,
5393 tree reference_type;
5395 /* Callers are responsible for handling error_mark_node as a
5396 destination type. */
5397 gcc_assert (dst_type != error_mark_node);
5398 /* In a template, callers should be building syntactic
5399 representations of casts, not using this machinery. */
5400 gcc_assert (!processing_template_decl);
5402 /* Assume the conversion is invalid. */
5406 if (!POINTER_TYPE_P (dst_type) && !TYPE_PTRMEM_P (dst_type))
5409 error ("invalid use of const_cast with type %qT, "
5410 "which is not a pointer, "
5411 "reference, nor a pointer-to-data-member type", dst_type);
5412 return error_mark_node;
5415 if (TREE_CODE (TREE_TYPE (dst_type)) == FUNCTION_TYPE)
5418 error ("invalid use of const_cast with type %qT, which is a pointer "
5419 "or reference to a function type", dst_type);
5420 return error_mark_node;
5423 /* Save casted types in the function's used types hash table. */
5424 used_types_insert (dst_type);
5426 src_type = TREE_TYPE (expr);
5427 /* Expressions do not really have reference types. */
5428 if (TREE_CODE (src_type) == REFERENCE_TYPE)
5429 src_type = TREE_TYPE (src_type);
5431 /* [expr.const.cast]
5433 An lvalue of type T1 can be explicitly converted to an lvalue of
5434 type T2 using the cast const_cast<T2&> (where T1 and T2 are object
5435 types) if a pointer to T1 can be explicitly converted to the type
5436 pointer to T2 using a const_cast. */
5437 if (TREE_CODE (dst_type) == REFERENCE_TYPE)
5439 reference_type = dst_type;
5440 if (! real_lvalue_p (expr))
5443 error ("invalid const_cast of an rvalue of type %qT to type %qT",
5444 src_type, dst_type);
5445 return error_mark_node;
5447 dst_type = build_pointer_type (TREE_TYPE (dst_type));
5448 src_type = build_pointer_type (src_type);
5452 reference_type = NULL_TREE;
5453 /* If the destination type is not a reference type, the
5454 lvalue-to-rvalue, array-to-pointer, and function-to-pointer
5455 conversions are performed. */
5456 src_type = type_decays_to (src_type);
5457 if (src_type == error_mark_node)
5458 return error_mark_node;
5461 if ((TYPE_PTR_P (src_type) || TYPE_PTRMEM_P (src_type))
5462 && comp_ptr_ttypes_const (dst_type, src_type))
5467 /* This cast is actually a C-style cast. Issue a warning if
5468 the user is making a potentially unsafe cast. */
5470 check_for_casting_away_constness (src_type, dst_type,
5476 expr = build_unary_op (ADDR_EXPR, expr, 0);
5477 expr = build_nop (reference_type, expr);
5478 return convert_from_reference (expr);
5482 expr = decay_conversion (expr);
5483 /* build_c_cast puts on a NOP_EXPR to make the result not an
5484 lvalue. Strip such NOP_EXPRs if VALUE is being used in
5485 non-lvalue context. */
5486 if (TREE_CODE (expr) == NOP_EXPR
5487 && TREE_TYPE (expr) == TREE_TYPE (TREE_OPERAND (expr, 0)))
5488 expr = TREE_OPERAND (expr, 0);
5489 return build_nop (dst_type, expr);
5494 error ("invalid const_cast from type %qT to type %qT",
5495 src_type, dst_type);
5496 return error_mark_node;
5500 build_const_cast (tree type, tree expr)
5502 if (type == error_mark_node || error_operand_p (expr))
5503 return error_mark_node;
5505 if (processing_template_decl)
5507 tree t = build_min (CONST_CAST_EXPR, type, expr);
5509 if (!TREE_SIDE_EFFECTS (t)
5510 && type_dependent_expression_p (expr))
5511 /* There might turn out to be side effects inside expr. */
5512 TREE_SIDE_EFFECTS (t) = 1;
5513 return convert_from_reference (t);
5516 return build_const_cast_1 (type, expr, /*complain=*/true,
5520 /* Build an expression representing an explicit C-style cast to type
5521 TYPE of expression EXPR. */
5524 build_c_cast (tree type, tree expr)
5530 if (type == error_mark_node || error_operand_p (expr))
5531 return error_mark_node;
5533 if (processing_template_decl)
5535 tree t = build_min (CAST_EXPR, type,
5536 tree_cons (NULL_TREE, value, NULL_TREE));
5537 /* We don't know if it will or will not have side effects. */
5538 TREE_SIDE_EFFECTS (t) = 1;
5539 return convert_from_reference (t);
5542 /* Casts to a (pointer to a) specific ObjC class (or 'id' or
5543 'Class') should always be retained, because this information aids
5544 in method lookup. */
5545 if (objc_is_object_ptr (type)
5546 && objc_is_object_ptr (TREE_TYPE (expr)))
5547 return build_nop (type, expr);
5549 /* build_c_cast puts on a NOP_EXPR to make the result not an lvalue.
5550 Strip such NOP_EXPRs if VALUE is being used in non-lvalue context. */
5551 if (TREE_CODE (type) != REFERENCE_TYPE
5552 && TREE_CODE (value) == NOP_EXPR
5553 && TREE_TYPE (value) == TREE_TYPE (TREE_OPERAND (value, 0)))
5554 value = TREE_OPERAND (value, 0);
5556 if (TREE_CODE (type) == ARRAY_TYPE)
5558 /* Allow casting from T1* to T2[] because Cfront allows it.
5559 NIHCL uses it. It is not valid ISO C++ however. */
5560 if (TREE_CODE (TREE_TYPE (expr)) == POINTER_TYPE)
5562 pedwarn ("ISO C++ forbids casting to an array type %qT", type);
5563 type = build_pointer_type (TREE_TYPE (type));
5567 error ("ISO C++ forbids casting to an array type %qT", type);
5568 return error_mark_node;
5572 if (TREE_CODE (type) == FUNCTION_TYPE
5573 || TREE_CODE (type) == METHOD_TYPE)
5575 error ("invalid cast to function type %qT", type);
5576 return error_mark_node;
5579 /* A C-style cast can be a const_cast. */
5580 result = build_const_cast_1 (type, value, /*complain=*/false,
5585 /* Or a static cast. */
5586 result = build_static_cast_1 (type, value, /*c_cast_p=*/true,
5588 /* Or a reinterpret_cast. */
5590 result = build_reinterpret_cast_1 (type, value, /*c_cast_p=*/true,
5592 /* The static_cast or reinterpret_cast may be followed by a
5595 /* A valid cast may result in errors if, for example, a
5596 conversion to am ambiguous base class is required. */
5597 && !error_operand_p (result))
5601 /* Non-class rvalues always have cv-unqualified type. */
5602 if (!CLASS_TYPE_P (type))
5603 type = TYPE_MAIN_VARIANT (type);
5604 result_type = TREE_TYPE (result);
5605 if (!CLASS_TYPE_P (result_type))
5606 result_type = TYPE_MAIN_VARIANT (result_type);
5607 /* If the type of RESULT does not match TYPE, perform a
5608 const_cast to make it match. If the static_cast or
5609 reinterpret_cast succeeded, we will differ by at most
5610 cv-qualification, so the follow-on const_cast is guaranteed
5612 if (!same_type_p (non_reference (type), non_reference (result_type)))
5614 result = build_const_cast_1 (type, result, false, &valid_p);
5615 gcc_assert (valid_p);
5620 return error_mark_node;
5623 /* Build an assignment expression of lvalue LHS from value RHS.
5624 MODIFYCODE is the code for a binary operator that we use
5625 to combine the old value of LHS with RHS to get the new value.
5626 Or else MODIFYCODE is NOP_EXPR meaning do a simple assignment.
5628 C++: If MODIFYCODE is INIT_EXPR, then leave references unbashed. */
5631 build_modify_expr (tree lhs, enum tree_code modifycode, tree rhs)
5635 tree lhstype = TREE_TYPE (lhs);
5636 tree olhstype = lhstype;
5637 tree olhs = NULL_TREE;
5638 bool plain_assign = (modifycode == NOP_EXPR);
5640 /* Avoid duplicate error messages from operands that had errors. */
5641 if (error_operand_p (lhs) || error_operand_p (rhs))
5642 return error_mark_node;
5644 /* Handle control structure constructs used as "lvalues". */
5645 switch (TREE_CODE (lhs))
5647 /* Handle --foo = 5; as these are valid constructs in C++. */
5648 case PREDECREMENT_EXPR:
5649 case PREINCREMENT_EXPR:
5650 if (TREE_SIDE_EFFECTS (TREE_OPERAND (lhs, 0)))
5651 lhs = build2 (TREE_CODE (lhs), TREE_TYPE (lhs),
5652 stabilize_reference (TREE_OPERAND (lhs, 0)),
5653 TREE_OPERAND (lhs, 1));
5654 return build2 (COMPOUND_EXPR, lhstype,
5656 build_modify_expr (TREE_OPERAND (lhs, 0),
5659 /* Handle (a, b) used as an "lvalue". */
5661 newrhs = build_modify_expr (TREE_OPERAND (lhs, 1),
5663 if (newrhs == error_mark_node)
5664 return error_mark_node;
5665 return build2 (COMPOUND_EXPR, lhstype,
5666 TREE_OPERAND (lhs, 0), newrhs);
5669 if (TREE_SIDE_EFFECTS (TREE_OPERAND (lhs, 0)))
5670 lhs = build2 (TREE_CODE (lhs), TREE_TYPE (lhs),
5671 stabilize_reference (TREE_OPERAND (lhs, 0)),
5672 TREE_OPERAND (lhs, 1));
5673 newrhs = build_modify_expr (TREE_OPERAND (lhs, 0), modifycode, rhs);
5674 if (newrhs == error_mark_node)
5675 return error_mark_node;
5676 return build2 (COMPOUND_EXPR, lhstype, lhs, newrhs);
5680 /* MIN_EXPR and MAX_EXPR are currently only permitted as lvalues,
5681 when neither operand has side-effects. */
5682 if (!lvalue_or_else (lhs, lv_assign))
5683 return error_mark_node;
5685 gcc_assert (!TREE_SIDE_EFFECTS (TREE_OPERAND (lhs, 0))
5686 && !TREE_SIDE_EFFECTS (TREE_OPERAND (lhs, 1)));
5688 lhs = build3 (COND_EXPR, TREE_TYPE (lhs),
5689 build2 (TREE_CODE (lhs) == MIN_EXPR ? LE_EXPR : GE_EXPR,
5691 TREE_OPERAND (lhs, 0),
5692 TREE_OPERAND (lhs, 1)),
5693 TREE_OPERAND (lhs, 0),
5694 TREE_OPERAND (lhs, 1));
5697 /* Handle (a ? b : c) used as an "lvalue". */
5700 /* Produce (a ? (b = rhs) : (c = rhs))
5701 except that the RHS goes through a save-expr
5702 so the code to compute it is only emitted once. */
5704 tree preeval = NULL_TREE;
5706 rhs = stabilize_expr (rhs, &preeval);
5708 /* Check this here to avoid odd errors when trying to convert
5709 a throw to the type of the COND_EXPR. */
5710 if (!lvalue_or_else (lhs, lv_assign))
5711 return error_mark_node;
5713 cond = build_conditional_expr
5714 (TREE_OPERAND (lhs, 0),
5715 build_modify_expr (TREE_OPERAND (lhs, 1),
5717 build_modify_expr (TREE_OPERAND (lhs, 2),
5720 if (cond == error_mark_node)
5722 /* Make sure the code to compute the rhs comes out
5723 before the split. */
5725 cond = build2 (COMPOUND_EXPR, TREE_TYPE (lhs), preeval, cond);
5733 if (modifycode == INIT_EXPR)
5735 if (TREE_CODE (rhs) == CONSTRUCTOR)
5737 if (! same_type_p (TREE_TYPE (rhs), lhstype))
5738 /* Call convert to generate an error; see PR 11063. */
5739 rhs = convert (lhstype, rhs);
5740 result = build2 (INIT_EXPR, lhstype, lhs, rhs);
5741 TREE_SIDE_EFFECTS (result) = 1;
5744 else if (! IS_AGGR_TYPE (lhstype))
5745 /* Do the default thing. */;
5748 result = build_special_member_call (lhs, complete_ctor_identifier,
5749 build_tree_list (NULL_TREE, rhs),
5750 lhstype, LOOKUP_NORMAL);
5751 if (result == NULL_TREE)
5752 return error_mark_node;
5758 lhs = require_complete_type (lhs);
5759 if (lhs == error_mark_node)
5760 return error_mark_node;
5762 if (modifycode == NOP_EXPR)
5764 /* `operator=' is not an inheritable operator. */
5765 if (! IS_AGGR_TYPE (lhstype))
5766 /* Do the default thing. */;
5769 result = build_new_op (MODIFY_EXPR, LOOKUP_NORMAL,
5770 lhs, rhs, make_node (NOP_EXPR),
5771 /*overloaded_p=*/NULL);
5772 if (result == NULL_TREE)
5773 return error_mark_node;
5780 /* A binary op has been requested. Combine the old LHS
5781 value with the RHS producing the value we should actually
5782 store into the LHS. */
5784 gcc_assert (!PROMOTES_TO_AGGR_TYPE (lhstype, REFERENCE_TYPE));
5785 lhs = stabilize_reference (lhs);
5786 newrhs = cp_build_binary_op (modifycode, lhs, rhs);
5787 if (newrhs == error_mark_node)
5789 error (" in evaluation of %<%Q(%#T, %#T)%>", modifycode,
5790 TREE_TYPE (lhs), TREE_TYPE (rhs));
5791 return error_mark_node;
5794 /* Now it looks like a plain assignment. */
5795 modifycode = NOP_EXPR;
5797 gcc_assert (TREE_CODE (lhstype) != REFERENCE_TYPE);
5798 gcc_assert (TREE_CODE (TREE_TYPE (newrhs)) != REFERENCE_TYPE);
5801 /* The left-hand side must be an lvalue. */
5802 if (!lvalue_or_else (lhs, lv_assign))
5803 return error_mark_node;
5805 /* Warn about modifying something that is `const'. Don't warn if
5806 this is initialization. */
5807 if (modifycode != INIT_EXPR
5808 && (TREE_READONLY (lhs) || CP_TYPE_CONST_P (lhstype)
5809 /* Functions are not modifiable, even though they are
5811 || TREE_CODE (TREE_TYPE (lhs)) == FUNCTION_TYPE
5812 || TREE_CODE (TREE_TYPE (lhs)) == METHOD_TYPE
5813 /* If it's an aggregate and any field is const, then it is
5814 effectively const. */
5815 || (CLASS_TYPE_P (lhstype)
5816 && C_TYPE_FIELDS_READONLY (lhstype))))
5817 readonly_error (lhs, "assignment", 0);
5819 /* If storing into a structure or union member, it has probably been
5820 given type `int'. Compute the type that would go with the actual
5821 amount of storage the member occupies. */
5823 if (TREE_CODE (lhs) == COMPONENT_REF
5824 && (TREE_CODE (lhstype) == INTEGER_TYPE
5825 || TREE_CODE (lhstype) == REAL_TYPE
5826 || TREE_CODE (lhstype) == ENUMERAL_TYPE))
5828 lhstype = TREE_TYPE (get_unwidened (lhs, 0));
5830 /* If storing in a field that is in actuality a short or narrower
5831 than one, we must store in the field in its actual type. */
5833 if (lhstype != TREE_TYPE (lhs))
5835 /* Avoid warnings converting integral types back into enums for
5837 if (TREE_CODE (lhstype) == INTEGER_TYPE
5838 && TREE_CODE (olhstype) == ENUMERAL_TYPE)
5840 if (TREE_SIDE_EFFECTS (lhs))
5841 lhs = stabilize_reference (lhs);
5844 lhs = copy_node (lhs);
5845 TREE_TYPE (lhs) = lhstype;
5849 /* Convert new value to destination type. */
5851 if (TREE_CODE (lhstype) == ARRAY_TYPE)
5855 if (!same_or_base_type_p (TYPE_MAIN_VARIANT (lhstype),
5856 TYPE_MAIN_VARIANT (TREE_TYPE (rhs))))
5858 error ("incompatible types in assignment of %qT to %qT",
5859 TREE_TYPE (rhs), lhstype);
5860 return error_mark_node;
5863 /* Allow array assignment in compiler-generated code. */
5864 if (! DECL_ARTIFICIAL (current_function_decl))
5866 /* This routine is used for both initialization and assignment.
5867 Make sure the diagnostic message differentiates the context. */
5868 if (modifycode == INIT_EXPR)
5869 error ("array used as initializer");
5871 error ("invalid array assignment");
5872 return error_mark_node;
5875 from_array = TREE_CODE (TREE_TYPE (newrhs)) == ARRAY_TYPE
5876 ? 1 + (modifycode != INIT_EXPR): 0;
5877 return build_vec_init (lhs, NULL_TREE, newrhs,
5878 /*explicit_default_init_p=*/false,
5882 if (modifycode == INIT_EXPR)
5883 newrhs = convert_for_initialization (lhs, lhstype, newrhs, LOOKUP_NORMAL,
5884 "initialization", NULL_TREE, 0);
5887 /* Avoid warnings on enum bit fields. */
5888 if (TREE_CODE (olhstype) == ENUMERAL_TYPE
5889 && TREE_CODE (lhstype) == INTEGER_TYPE)
5891 newrhs = convert_for_assignment (olhstype, newrhs, "assignment",
5893 newrhs = convert_force (lhstype, newrhs, 0);
5896 newrhs = convert_for_assignment (lhstype, newrhs, "assignment",
5898 if (TREE_CODE (newrhs) == CALL_EXPR
5899 && TYPE_NEEDS_CONSTRUCTING (lhstype))
5900 newrhs = build_cplus_new (lhstype, newrhs);
5902 /* Can't initialize directly from a TARGET_EXPR, since that would
5903 cause the lhs to be constructed twice, and possibly result in
5904 accidental self-initialization. So we force the TARGET_EXPR to be
5905 expanded without a target. */
5906 if (TREE_CODE (newrhs) == TARGET_EXPR)
5907 newrhs = build2 (COMPOUND_EXPR, TREE_TYPE (newrhs), newrhs,
5908 TREE_OPERAND (newrhs, 0));
5911 if (newrhs == error_mark_node)
5912 return error_mark_node;
5914 if (c_dialect_objc () && flag_objc_gc)
5916 result = objc_generate_write_barrier (lhs, modifycode, newrhs);
5922 result = build2 (modifycode == NOP_EXPR ? MODIFY_EXPR : INIT_EXPR,
5923 lhstype, lhs, newrhs);
5925 TREE_SIDE_EFFECTS (result) = 1;
5927 TREE_NO_WARNING (result) = 1;
5929 /* If we got the LHS in a different type for storing in,
5930 convert the result back to the nominal type of LHS
5931 so that the value we return always has the same type
5932 as the LHS argument. */
5934 if (olhstype == TREE_TYPE (result))
5938 result = build2 (COMPOUND_EXPR, olhstype, result, olhs);
5939 TREE_NO_WARNING (result) = 1;
5942 return convert_for_assignment (olhstype, result, "assignment",
5947 build_x_modify_expr (tree lhs, enum tree_code modifycode, tree rhs)
5949 if (processing_template_decl)
5950 return build_min_nt (MODOP_EXPR, lhs,
5951 build_min_nt (modifycode, NULL_TREE, NULL_TREE), rhs);
5953 if (modifycode != NOP_EXPR)
5955 tree rval = build_new_op (MODIFY_EXPR, LOOKUP_NORMAL, lhs, rhs,
5956 make_node (modifycode),
5957 /*overloaded_p=*/NULL);
5960 TREE_NO_WARNING (rval) = 1;
5964 return build_modify_expr (lhs, modifycode, rhs);
5968 /* Get difference in deltas for different pointer to member function
5969 types. Returns an integer constant of type PTRDIFF_TYPE_NODE. If
5970 the conversion is invalid, the constant is zero. If
5971 ALLOW_INVERSE_P is true, then allow reverse conversions as well.
5972 If C_CAST_P is true this conversion is taking place as part of a
5975 Note that the naming of FROM and TO is kind of backwards; the return
5976 value is what we add to a TO in order to get a FROM. They are named
5977 this way because we call this function to find out how to convert from
5978 a pointer to member of FROM to a pointer to member of TO. */
5981 get_delta_difference (tree from, tree to,
5982 bool allow_inverse_p,
5989 /* Assume no conversion is required. */
5990 result = integer_zero_node;
5991 binfo = lookup_base (to, from, c_cast_p ? ba_unique : ba_check, &kind);
5992 if (kind == bk_inaccessible || kind == bk_ambig)
5993 error (" in pointer to member function conversion");
5996 if (kind != bk_via_virtual)
5997 result = BINFO_OFFSET (binfo);
6000 tree virt_binfo = binfo_from_vbase (binfo);
6002 /* This is a reinterpret cast, we choose to do nothing. */
6003 if (allow_inverse_p)
6004 warning (0, "pointer to member cast via virtual base %qT",
6005 BINFO_TYPE (virt_binfo));
6007 error ("pointer to member conversion via virtual base %qT",
6008 BINFO_TYPE (virt_binfo));
6011 else if (same_type_ignoring_top_level_qualifiers_p (from, to))
6012 /* Pointer to member of incomplete class is permitted*/;
6013 else if (!allow_inverse_p)
6015 error_not_base_type (from, to);
6016 error (" in pointer to member conversion");
6020 binfo = lookup_base (from, to, c_cast_p ? ba_unique : ba_check, &kind);
6023 if (kind != bk_via_virtual)
6024 result = size_diffop (size_zero_node, BINFO_OFFSET (binfo));
6027 /* This is a reinterpret cast, we choose to do nothing. */
6028 tree virt_binfo = binfo_from_vbase (binfo);
6030 warning (0, "pointer to member cast via virtual base %qT",
6031 BINFO_TYPE (virt_binfo));
6036 return fold_if_not_in_template (convert_to_integer (ptrdiff_type_node,
6040 /* Return a constructor for the pointer-to-member-function TYPE using
6041 the other components as specified. */
6044 build_ptrmemfunc1 (tree type, tree delta, tree pfn)
6049 VEC(constructor_elt, gc) *v;
6051 /* Pull the FIELD_DECLs out of the type. */
6052 pfn_field = TYPE_FIELDS (type);
6053 delta_field = TREE_CHAIN (pfn_field);
6055 /* Make sure DELTA has the type we want. */
6056 delta = convert_and_check (delta_type_node, delta);
6058 /* Finish creating the initializer. */
6059 v = VEC_alloc(constructor_elt, gc, 2);
6060 CONSTRUCTOR_APPEND_ELT(v, pfn_field, pfn);
6061 CONSTRUCTOR_APPEND_ELT(v, delta_field, delta);
6062 u = build_constructor (type, v);
6063 TREE_CONSTANT (u) = TREE_CONSTANT (pfn) & TREE_CONSTANT (delta);
6064 TREE_INVARIANT (u) = TREE_INVARIANT (pfn) & TREE_INVARIANT (delta);
6065 TREE_STATIC (u) = (TREE_CONSTANT (u)
6066 && (initializer_constant_valid_p (pfn, TREE_TYPE (pfn))
6068 && (initializer_constant_valid_p (delta, TREE_TYPE (delta))
6073 /* Build a constructor for a pointer to member function. It can be
6074 used to initialize global variables, local variable, or used
6075 as a value in expressions. TYPE is the POINTER to METHOD_TYPE we
6078 If FORCE is nonzero, then force this conversion, even if
6079 we would rather not do it. Usually set when using an explicit
6080 cast. A C-style cast is being processed iff C_CAST_P is true.
6082 Return error_mark_node, if something goes wrong. */
6085 build_ptrmemfunc (tree type, tree pfn, int force, bool c_cast_p)
6091 if (error_operand_p (pfn))
6092 return error_mark_node;
6094 pfn_type = TREE_TYPE (pfn);
6095 to_type = build_ptrmemfunc_type (type);
6097 /* Handle multiple conversions of pointer to member functions. */
6098 if (TYPE_PTRMEMFUNC_P (pfn_type))
6100 tree delta = NULL_TREE;
6101 tree npfn = NULL_TREE;
6105 && !can_convert_arg (to_type, TREE_TYPE (pfn), pfn, LOOKUP_NORMAL))
6106 error ("invalid conversion to type %qT from type %qT",
6109 n = get_delta_difference (TYPE_PTRMEMFUNC_OBJECT_TYPE (pfn_type),
6110 TYPE_PTRMEMFUNC_OBJECT_TYPE (to_type),
6114 /* We don't have to do any conversion to convert a
6115 pointer-to-member to its own type. But, we don't want to
6116 just return a PTRMEM_CST if there's an explicit cast; that
6117 cast should make the expression an invalid template argument. */
6118 if (TREE_CODE (pfn) != PTRMEM_CST)
6120 if (same_type_p (to_type, pfn_type))
6122 else if (integer_zerop (n))
6123 return build_reinterpret_cast (to_type, pfn);
6126 if (TREE_SIDE_EFFECTS (pfn))
6127 pfn = save_expr (pfn);
6129 /* Obtain the function pointer and the current DELTA. */
6130 if (TREE_CODE (pfn) == PTRMEM_CST)
6131 expand_ptrmemfunc_cst (pfn, &delta, &npfn);
6134 npfn = build_ptrmemfunc_access_expr (pfn, pfn_identifier);
6135 delta = build_ptrmemfunc_access_expr (pfn, delta_identifier);
6138 /* Just adjust the DELTA field. */
6139 gcc_assert (same_type_ignoring_top_level_qualifiers_p
6140 (TREE_TYPE (delta), ptrdiff_type_node));
6141 if (TARGET_PTRMEMFUNC_VBIT_LOCATION == ptrmemfunc_vbit_in_delta)
6142 n = cp_build_binary_op (LSHIFT_EXPR, n, integer_one_node);
6143 delta = cp_build_binary_op (PLUS_EXPR, delta, n);
6144 return build_ptrmemfunc1 (to_type, delta, npfn);
6147 /* Handle null pointer to member function conversions. */
6148 if (integer_zerop (pfn))
6150 pfn = build_c_cast (type, integer_zero_node);
6151 return build_ptrmemfunc1 (to_type,
6156 if (type_unknown_p (pfn))
6157 return instantiate_type (type, pfn, tf_warning_or_error);
6159 fn = TREE_OPERAND (pfn, 0);
6160 gcc_assert (TREE_CODE (fn) == FUNCTION_DECL
6161 /* In a template, we will have preserved the
6163 || (processing_template_decl && TREE_CODE (fn) == OFFSET_REF));
6164 return make_ptrmem_cst (to_type, fn);
6167 /* Return the DELTA, IDX, PFN, and DELTA2 values for the PTRMEM_CST
6170 ??? There is no consistency as to the types returned for the above
6171 values. Some code acts as if it were a sizetype and some as if it were
6172 integer_type_node. */
6175 expand_ptrmemfunc_cst (tree cst, tree *delta, tree *pfn)
6177 tree type = TREE_TYPE (cst);
6178 tree fn = PTRMEM_CST_MEMBER (cst);
6179 tree ptr_class, fn_class;
6181 gcc_assert (TREE_CODE (fn) == FUNCTION_DECL);
6183 /* The class that the function belongs to. */
6184 fn_class = DECL_CONTEXT (fn);
6186 /* The class that we're creating a pointer to member of. */
6187 ptr_class = TYPE_PTRMEMFUNC_OBJECT_TYPE (type);
6189 /* First, calculate the adjustment to the function's class. */
6190 *delta = get_delta_difference (fn_class, ptr_class, /*force=*/0,
6193 if (!DECL_VIRTUAL_P (fn))
6194 *pfn = convert (TYPE_PTRMEMFUNC_FN_TYPE (type), build_addr_func (fn));
6197 /* If we're dealing with a virtual function, we have to adjust 'this'
6198 again, to point to the base which provides the vtable entry for
6199 fn; the call will do the opposite adjustment. */
6200 tree orig_class = DECL_CONTEXT (fn);
6201 tree binfo = binfo_or_else (orig_class, fn_class);
6202 *delta = build2 (PLUS_EXPR, TREE_TYPE (*delta),
6203 *delta, BINFO_OFFSET (binfo));
6204 *delta = fold_if_not_in_template (*delta);
6206 /* We set PFN to the vtable offset at which the function can be
6207 found, plus one (unless ptrmemfunc_vbit_in_delta, in which
6208 case delta is shifted left, and then incremented). */
6209 *pfn = DECL_VINDEX (fn);
6210 *pfn = build2 (MULT_EXPR, integer_type_node, *pfn,
6211 TYPE_SIZE_UNIT (vtable_entry_type));
6212 *pfn = fold_if_not_in_template (*pfn);
6214 switch (TARGET_PTRMEMFUNC_VBIT_LOCATION)
6216 case ptrmemfunc_vbit_in_pfn:
6217 *pfn = build2 (PLUS_EXPR, integer_type_node, *pfn,
6219 *pfn = fold_if_not_in_template (*pfn);
6222 case ptrmemfunc_vbit_in_delta:
6223 *delta = build2 (LSHIFT_EXPR, TREE_TYPE (*delta),
6224 *delta, integer_one_node);
6225 *delta = fold_if_not_in_template (*delta);
6226 *delta = build2 (PLUS_EXPR, TREE_TYPE (*delta),
6227 *delta, integer_one_node);
6228 *delta = fold_if_not_in_template (*delta);
6235 *pfn = build_nop (TYPE_PTRMEMFUNC_FN_TYPE (type), *pfn);
6236 *pfn = fold_if_not_in_template (*pfn);
6240 /* Return an expression for PFN from the pointer-to-member function
6244 pfn_from_ptrmemfunc (tree t)
6246 if (TREE_CODE (t) == PTRMEM_CST)
6251 expand_ptrmemfunc_cst (t, &delta, &pfn);
6256 return build_ptrmemfunc_access_expr (t, pfn_identifier);
6259 /* Convert value RHS to type TYPE as preparation for an assignment to
6260 an lvalue of type TYPE. ERRTYPE is a string to use in error
6261 messages: "assignment", "return", etc. If FNDECL is non-NULL, we
6262 are doing the conversion in order to pass the PARMNUMth argument of
6266 convert_for_assignment (tree type, tree rhs,
6267 const char *errtype, tree fndecl, int parmnum)
6270 enum tree_code coder;
6272 /* Strip NON_LVALUE_EXPRs since we aren't using as an lvalue. */
6273 if (TREE_CODE (rhs) == NON_LVALUE_EXPR)
6274 rhs = TREE_OPERAND (rhs, 0);
6276 rhstype = TREE_TYPE (rhs);
6277 coder = TREE_CODE (rhstype);
6279 if (TREE_CODE (type) == VECTOR_TYPE && coder == VECTOR_TYPE
6280 && vector_types_convertible_p (type, rhstype))
6281 return convert (type, rhs);
6283 if (rhs == error_mark_node || rhstype == error_mark_node)
6284 return error_mark_node;
6285 if (TREE_CODE (rhs) == TREE_LIST && TREE_VALUE (rhs) == error_mark_node)
6286 return error_mark_node;
6288 /* The RHS of an assignment cannot have void type. */
6289 if (coder == VOID_TYPE)
6291 error ("void value not ignored as it ought to be");
6292 return error_mark_node;
6295 /* Simplify the RHS if possible. */
6296 if (TREE_CODE (rhs) == CONST_DECL)
6297 rhs = DECL_INITIAL (rhs);
6299 if (c_dialect_objc ())
6302 tree rname = fndecl;
6304 if (!strcmp (errtype, "assignment"))
6306 else if (!strcmp (errtype, "initialization"))
6310 tree selector = objc_message_selector ();
6314 if (selector && parmno > 1)
6321 if (objc_compare_types (type, rhstype, parmno, rname))
6322 return convert (type, rhs);
6327 The expression is implicitly converted (clause _conv_) to the
6328 cv-unqualified type of the left operand.
6330 We allow bad conversions here because by the time we get to this point
6331 we are committed to doing the conversion. If we end up doing a bad
6332 conversion, convert_like will complain. */
6333 if (!can_convert_arg_bad (type, rhstype, rhs))
6335 /* When -Wno-pmf-conversions is use, we just silently allow
6336 conversions from pointers-to-members to plain pointers. If
6337 the conversion doesn't work, cp_convert will complain. */
6339 && TYPE_PTR_P (type)
6340 && TYPE_PTRMEMFUNC_P (rhstype))
6341 rhs = cp_convert (strip_top_quals (type), rhs);
6344 /* If the right-hand side has unknown type, then it is an
6345 overloaded function. Call instantiate_type to get error
6347 if (rhstype == unknown_type_node)
6348 instantiate_type (type, rhs, tf_warning_or_error);
6350 error ("cannot convert %qT to %qT for argument %qP to %qD",
6351 rhstype, type, parmnum, fndecl);
6353 error ("cannot convert %qT to %qT in %s", rhstype, type, errtype);
6354 return error_mark_node;
6357 if (warn_missing_format_attribute)
6359 const enum tree_code codel = TREE_CODE (type);
6360 if ((codel == POINTER_TYPE || codel == REFERENCE_TYPE)
6362 && check_missing_format_attribute (type, rhstype))
6363 warning (OPT_Wmissing_format_attribute,
6364 "%s might be a candidate for a format attribute",
6368 return perform_implicit_conversion (strip_top_quals (type), rhs);
6371 /* Convert RHS to be of type TYPE.
6372 If EXP is nonzero, it is the target of the initialization.
6373 ERRTYPE is a string to use in error messages.
6375 Two major differences between the behavior of
6376 `convert_for_assignment' and `convert_for_initialization'
6377 are that references are bashed in the former, while
6378 copied in the latter, and aggregates are assigned in
6379 the former (operator=) while initialized in the
6382 If using constructor make sure no conversion operator exists, if one does
6383 exist, an ambiguity exists.
6385 If flags doesn't include LOOKUP_COMPLAIN, don't complain about anything. */
6388 convert_for_initialization (tree exp, tree type, tree rhs, int flags,
6389 const char *errtype, tree fndecl, int parmnum)
6391 enum tree_code codel = TREE_CODE (type);
6393 enum tree_code coder;
6395 /* build_c_cast puts on a NOP_EXPR to make the result not an lvalue.
6396 Strip such NOP_EXPRs, since RHS is used in non-lvalue context. */
6397 if (TREE_CODE (rhs) == NOP_EXPR
6398 && TREE_TYPE (rhs) == TREE_TYPE (TREE_OPERAND (rhs, 0))
6399 && codel != REFERENCE_TYPE)
6400 rhs = TREE_OPERAND (rhs, 0);
6402 if (type == error_mark_node
6403 || rhs == error_mark_node
6404 || (TREE_CODE (rhs) == TREE_LIST && TREE_VALUE (rhs) == error_mark_node))
6405 return error_mark_node;
6407 if ((TREE_CODE (TREE_TYPE (rhs)) == ARRAY_TYPE
6408 && TREE_CODE (type) != ARRAY_TYPE
6409 && (TREE_CODE (type) != REFERENCE_TYPE
6410 || TREE_CODE (TREE_TYPE (type)) != ARRAY_TYPE))
6411 || (TREE_CODE (TREE_TYPE (rhs)) == FUNCTION_TYPE
6412 && (TREE_CODE (type) != REFERENCE_TYPE
6413 || TREE_CODE (TREE_TYPE (type)) != FUNCTION_TYPE))
6414 || TREE_CODE (TREE_TYPE (rhs)) == METHOD_TYPE)
6415 rhs = decay_conversion (rhs);
6417 rhstype = TREE_TYPE (rhs);
6418 coder = TREE_CODE (rhstype);
6420 if (coder == ERROR_MARK)
6421 return error_mark_node;
6423 /* We accept references to incomplete types, so we can
6424 return here before checking if RHS is of complete type. */
6426 if (codel == REFERENCE_TYPE)
6428 /* This should eventually happen in convert_arguments. */
6429 int savew = 0, savee = 0;
6432 savew = warningcount, savee = errorcount;
6433 rhs = initialize_reference (type, rhs, /*decl=*/NULL_TREE,
6437 if (warningcount > savew)
6438 warning (0, "in passing argument %P of %q+D", parmnum, fndecl);
6439 else if (errorcount > savee)
6440 error ("in passing argument %P of %q+D", parmnum, fndecl);
6446 exp = require_complete_type (exp);
6447 if (exp == error_mark_node)
6448 return error_mark_node;
6450 rhstype = non_reference (rhstype);
6452 type = complete_type (type);
6454 if (IS_AGGR_TYPE (type))
6455 return ocp_convert (type, rhs, CONV_IMPLICIT|CONV_FORCE_TEMP, flags);
6457 return convert_for_assignment (type, rhs, errtype, fndecl, parmnum);
6460 /* If RETVAL is the address of, or a reference to, a local variable or
6461 temporary give an appropriate warning. */
6464 maybe_warn_about_returning_address_of_local (tree retval)
6466 tree valtype = TREE_TYPE (DECL_RESULT (current_function_decl));
6467 tree whats_returned = retval;
6471 if (TREE_CODE (whats_returned) == COMPOUND_EXPR)
6472 whats_returned = TREE_OPERAND (whats_returned, 1);
6473 else if (TREE_CODE (whats_returned) == CONVERT_EXPR
6474 || TREE_CODE (whats_returned) == NON_LVALUE_EXPR
6475 || TREE_CODE (whats_returned) == NOP_EXPR)
6476 whats_returned = TREE_OPERAND (whats_returned, 0);
6481 if (TREE_CODE (whats_returned) != ADDR_EXPR)
6483 whats_returned = TREE_OPERAND (whats_returned, 0);
6485 if (TREE_CODE (valtype) == REFERENCE_TYPE)
6487 if (TREE_CODE (whats_returned) == AGGR_INIT_EXPR
6488 || TREE_CODE (whats_returned) == TARGET_EXPR)
6490 warning (0, "returning reference to temporary");
6493 if (TREE_CODE (whats_returned) == VAR_DECL
6494 && DECL_NAME (whats_returned)
6495 && TEMP_NAME_P (DECL_NAME (whats_returned)))
6497 warning (0, "reference to non-lvalue returned");
6502 while (TREE_CODE (whats_returned) == COMPONENT_REF
6503 || TREE_CODE (whats_returned) == ARRAY_REF)
6504 whats_returned = TREE_OPERAND (whats_returned, 0);
6506 if (DECL_P (whats_returned)
6507 && DECL_NAME (whats_returned)
6508 && DECL_FUNCTION_SCOPE_P (whats_returned)
6509 && !(TREE_STATIC (whats_returned)
6510 || TREE_PUBLIC (whats_returned)))
6512 if (TREE_CODE (valtype) == REFERENCE_TYPE)
6513 warning (0, "reference to local variable %q+D returned",
6516 warning (0, "address of local variable %q+D returned",
6522 /* Check that returning RETVAL from the current function is valid.
6523 Return an expression explicitly showing all conversions required to
6524 change RETVAL into the function return type, and to assign it to
6525 the DECL_RESULT for the function. Set *NO_WARNING to true if
6526 code reaches end of non-void function warning shouldn't be issued
6527 on this RETURN_EXPR. */
6530 check_return_expr (tree retval, bool *no_warning)
6533 /* The type actually returned by the function, after any
6536 int fn_returns_value_p;
6538 *no_warning = false;
6540 /* A `volatile' function is one that isn't supposed to return, ever.
6541 (This is a G++ extension, used to get better code for functions
6542 that call the `volatile' function.) */
6543 if (TREE_THIS_VOLATILE (current_function_decl))
6544 warning (0, "function declared %<noreturn%> has a %<return%> statement");
6546 /* Check for various simple errors. */
6547 if (DECL_DESTRUCTOR_P (current_function_decl))
6550 error ("returning a value from a destructor");
6553 else if (DECL_CONSTRUCTOR_P (current_function_decl))
6555 if (in_function_try_handler)
6556 /* If a return statement appears in a handler of the
6557 function-try-block of a constructor, the program is ill-formed. */
6558 error ("cannot return from a handler of a function-try-block of a constructor");
6560 /* You can't return a value from a constructor. */
6561 error ("returning a value from a constructor");
6565 if (processing_template_decl)
6567 current_function_returns_value = 1;
6571 /* When no explicit return-value is given in a function with a named
6572 return value, the named return value is used. */
6573 result = DECL_RESULT (current_function_decl);
6574 valtype = TREE_TYPE (result);
6575 gcc_assert (valtype != NULL_TREE);
6576 fn_returns_value_p = !VOID_TYPE_P (valtype);
6577 if (!retval && DECL_NAME (result) && fn_returns_value_p)
6580 /* Check for a return statement with no return value in a function
6581 that's supposed to return a value. */
6582 if (!retval && fn_returns_value_p)
6584 pedwarn ("return-statement with no value, in function returning %qT",
6586 /* Clear this, so finish_function won't say that we reach the
6587 end of a non-void function (which we don't, we gave a
6589 current_function_returns_null = 0;
6590 /* And signal caller that TREE_NO_WARNING should be set on the
6591 RETURN_EXPR to avoid control reaches end of non-void function
6592 warnings in tree-cfg.c. */
6595 /* Check for a return statement with a value in a function that
6596 isn't supposed to return a value. */
6597 else if (retval && !fn_returns_value_p)
6599 if (VOID_TYPE_P (TREE_TYPE (retval)))
6600 /* You can return a `void' value from a function of `void'
6601 type. In that case, we have to evaluate the expression for
6602 its side-effects. */
6603 finish_expr_stmt (retval);
6605 pedwarn ("return-statement with a value, in function "
6606 "returning 'void'");
6608 current_function_returns_null = 1;
6610 /* There's really no value to return, after all. */
6614 /* Remember that this function can sometimes return without a
6616 current_function_returns_null = 1;
6618 /* Remember that this function did return a value. */
6619 current_function_returns_value = 1;
6621 /* Check for erroneous operands -- but after giving ourselves a
6622 chance to provide an error about returning a value from a void
6624 if (error_operand_p (retval))
6626 current_function_return_value = error_mark_node;
6627 return error_mark_node;
6630 /* Only operator new(...) throw(), can return NULL [expr.new/13]. */
6631 if ((DECL_OVERLOADED_OPERATOR_P (current_function_decl) == NEW_EXPR
6632 || DECL_OVERLOADED_OPERATOR_P (current_function_decl) == VEC_NEW_EXPR)
6633 && !TYPE_NOTHROW_P (TREE_TYPE (current_function_decl))
6635 && null_ptr_cst_p (retval))
6636 warning (0, "%<operator new%> must not return NULL unless it is "
6637 "declared %<throw()%> (or -fcheck-new is in effect)");
6639 /* Effective C++ rule 15. See also start_function. */
6641 && DECL_NAME (current_function_decl) == ansi_assopname(NOP_EXPR))
6645 /* The function return type must be a reference to the current
6647 if (TREE_CODE (valtype) == REFERENCE_TYPE
6648 && same_type_ignoring_top_level_qualifiers_p
6649 (TREE_TYPE (valtype), TREE_TYPE (current_class_ref)))
6651 /* Returning '*this' is obviously OK. */
6652 if (retval == current_class_ref)
6654 /* If we are calling a function whose return type is the same of
6655 the current class reference, it is ok. */
6656 else if (TREE_CODE (retval) == INDIRECT_REF
6657 && TREE_CODE (TREE_OPERAND (retval, 0)) == CALL_EXPR)
6662 warning (OPT_Weffc__, "%<operator=%> should return a reference to %<*this%>");
6665 /* The fabled Named Return Value optimization, as per [class.copy]/15:
6667 [...] For a function with a class return type, if the expression
6668 in the return statement is the name of a local object, and the cv-
6669 unqualified type of the local object is the same as the function
6670 return type, an implementation is permitted to omit creating the tem-
6671 porary object to hold the function return value [...]
6673 So, if this is a value-returning function that always returns the same
6674 local variable, remember it.
6676 It might be nice to be more flexible, and choose the first suitable
6677 variable even if the function sometimes returns something else, but
6678 then we run the risk of clobbering the variable we chose if the other
6679 returned expression uses the chosen variable somehow. And people expect
6680 this restriction, anyway. (jason 2000-11-19)
6682 See finish_function and finalize_nrv for the rest of this optimization. */
6684 if (fn_returns_value_p && flag_elide_constructors)
6686 if (retval != NULL_TREE
6687 && (current_function_return_value == NULL_TREE
6688 || current_function_return_value == retval)
6689 && TREE_CODE (retval) == VAR_DECL
6690 && DECL_CONTEXT (retval) == current_function_decl
6691 && ! TREE_STATIC (retval)
6692 && (DECL_ALIGN (retval)
6693 >= DECL_ALIGN (DECL_RESULT (current_function_decl)))
6694 && same_type_p ((TYPE_MAIN_VARIANT
6695 (TREE_TYPE (retval))),
6697 (TREE_TYPE (TREE_TYPE (current_function_decl))))))
6698 current_function_return_value = retval;
6700 current_function_return_value = error_mark_node;
6703 /* We don't need to do any conversions when there's nothing being
6708 /* Do any required conversions. */
6709 if (retval == result || DECL_CONSTRUCTOR_P (current_function_decl))
6710 /* No conversions are required. */
6714 /* The type the function is declared to return. */
6715 tree functype = TREE_TYPE (TREE_TYPE (current_function_decl));
6717 /* The functype's return type will have been set to void, if it
6718 was an incomplete type. Just treat this as 'return;' */
6719 if (VOID_TYPE_P (functype))
6720 return error_mark_node;
6722 /* First convert the value to the function's return type, then
6723 to the type of return value's location to handle the
6724 case that functype is smaller than the valtype. */
6725 retval = convert_for_initialization
6726 (NULL_TREE, functype, retval, LOOKUP_NORMAL|LOOKUP_ONLYCONVERTING,
6727 "return", NULL_TREE, 0);
6728 retval = convert (valtype, retval);
6730 /* If the conversion failed, treat this just like `return;'. */
6731 if (retval == error_mark_node)
6733 /* We can't initialize a register from a AGGR_INIT_EXPR. */
6734 else if (! current_function_returns_struct
6735 && TREE_CODE (retval) == TARGET_EXPR
6736 && TREE_CODE (TREE_OPERAND (retval, 1)) == AGGR_INIT_EXPR)
6737 retval = build2 (COMPOUND_EXPR, TREE_TYPE (retval), retval,
6738 TREE_OPERAND (retval, 0));
6740 maybe_warn_about_returning_address_of_local (retval);
6743 /* Actually copy the value returned into the appropriate location. */
6744 if (retval && retval != result)
6745 retval = build2 (INIT_EXPR, TREE_TYPE (result), result, retval);
6751 /* Returns nonzero if the pointer-type FROM can be converted to the
6752 pointer-type TO via a qualification conversion. If CONSTP is -1,
6753 then we return nonzero if the pointers are similar, and the
6754 cv-qualification signature of FROM is a proper subset of that of TO.
6756 If CONSTP is positive, then all outer pointers have been
6760 comp_ptr_ttypes_real (tree to, tree from, int constp)
6762 bool to_more_cv_qualified = false;
6764 for (; ; to = TREE_TYPE (to), from = TREE_TYPE (from))
6766 if (TREE_CODE (to) != TREE_CODE (from))
6769 if (TREE_CODE (from) == OFFSET_TYPE
6770 && !same_type_p (TYPE_OFFSET_BASETYPE (from),
6771 TYPE_OFFSET_BASETYPE (to)))
6774 /* Const and volatile mean something different for function types,
6775 so the usual checks are not appropriate. */
6776 if (TREE_CODE (to) != FUNCTION_TYPE && TREE_CODE (to) != METHOD_TYPE)
6778 /* In Objective-C++, some types may have been 'volatilized' by
6779 the compiler for EH; when comparing them here, the volatile
6780 qualification must be ignored. */
6781 bool objc_quals_match = objc_type_quals_match (to, from);
6783 if (!at_least_as_qualified_p (to, from) && !objc_quals_match)
6786 if (!at_least_as_qualified_p (from, to) && !objc_quals_match)
6790 to_more_cv_qualified = true;
6794 constp &= TYPE_READONLY (to);
6797 if (TREE_CODE (to) != POINTER_TYPE && !TYPE_PTRMEM_P (to))
6798 return ((constp >= 0 || to_more_cv_qualified)
6799 && same_type_ignoring_top_level_qualifiers_p (to, from));
6803 /* When comparing, say, char ** to char const **, this function takes
6804 the 'char *' and 'char const *'. Do not pass non-pointer/reference
6805 types to this function. */
6808 comp_ptr_ttypes (tree to, tree from)
6810 return comp_ptr_ttypes_real (to, from, 1);
6813 /* Returns 1 if to and from are (possibly multi-level) pointers to the same
6814 type or inheritance-related types, regardless of cv-quals. */
6817 ptr_reasonably_similar (tree to, tree from)
6819 for (; ; to = TREE_TYPE (to), from = TREE_TYPE (from))
6821 /* Any target type is similar enough to void. */
6822 if (TREE_CODE (to) == VOID_TYPE
6823 || TREE_CODE (from) == VOID_TYPE)
6826 if (TREE_CODE (to) != TREE_CODE (from))
6829 if (TREE_CODE (from) == OFFSET_TYPE
6830 && comptypes (TYPE_OFFSET_BASETYPE (to),
6831 TYPE_OFFSET_BASETYPE (from),
6832 COMPARE_BASE | COMPARE_DERIVED))
6835 if (TREE_CODE (to) == VECTOR_TYPE
6836 && vector_types_convertible_p (to, from))
6839 if (TREE_CODE (to) == INTEGER_TYPE
6840 && TYPE_PRECISION (to) == TYPE_PRECISION (from))
6843 if (TREE_CODE (to) == FUNCTION_TYPE)
6846 if (TREE_CODE (to) != POINTER_TYPE)
6848 (TYPE_MAIN_VARIANT (to), TYPE_MAIN_VARIANT (from),
6849 COMPARE_BASE | COMPARE_DERIVED);
6853 /* Return true if TO and FROM (both of which are POINTER_TYPEs or
6854 pointer-to-member types) are the same, ignoring cv-qualification at
6858 comp_ptr_ttypes_const (tree to, tree from)
6860 for (; ; to = TREE_TYPE (to), from = TREE_TYPE (from))
6862 if (TREE_CODE (to) != TREE_CODE (from))
6865 if (TREE_CODE (from) == OFFSET_TYPE
6866 && same_type_p (TYPE_OFFSET_BASETYPE (from),
6867 TYPE_OFFSET_BASETYPE (to)))
6870 if (TREE_CODE (to) != POINTER_TYPE)
6871 return same_type_ignoring_top_level_qualifiers_p (to, from);
6875 /* Returns the type qualifiers for this type, including the qualifiers on the
6876 elements for an array type. */
6879 cp_type_quals (tree type)
6881 type = strip_array_types (type);
6882 if (type == error_mark_node)
6883 return TYPE_UNQUALIFIED;
6884 return TYPE_QUALS (type);
6887 /* Returns nonzero if the TYPE contains a mutable member. */
6890 cp_has_mutable_p (tree type)
6892 type = strip_array_types (type);
6894 return CLASS_TYPE_P (type) && CLASSTYPE_HAS_MUTABLE (type);
6897 /* Apply the TYPE_QUALS to the new DECL. */
6899 cp_apply_type_quals_to_decl (int type_quals, tree decl)
6901 tree type = TREE_TYPE (decl);
6903 if (type == error_mark_node)
6906 if (TREE_CODE (type) == FUNCTION_TYPE
6907 && type_quals != TYPE_UNQUALIFIED)
6909 /* This was an error in C++98 (cv-qualifiers cannot be added to
6910 a function type), but DR 295 makes the code well-formed by
6911 dropping the extra qualifiers. */
6914 tree bad_type = build_qualified_type (type, type_quals);
6915 pedwarn ("ignoring %qV qualifiers added to function type %qT",
6919 TREE_TYPE (decl) = TYPE_MAIN_VARIANT (type);
6923 /* Avoid setting TREE_READONLY incorrectly. */
6924 if (/* If the object has a constructor, the constructor may modify
6926 TYPE_NEEDS_CONSTRUCTING (type)
6927 /* If the type isn't complete, we don't know yet if it will need
6929 || !COMPLETE_TYPE_P (type)
6930 /* If the type has a mutable component, that component might be
6932 || TYPE_HAS_MUTABLE_P (type))
6933 type_quals &= ~TYPE_QUAL_CONST;
6935 c_apply_type_quals_to_decl (type_quals, decl);
6938 /* Subroutine of casts_away_constness. Make T1 and T2 point at
6939 exemplar types such that casting T1 to T2 is casting away constness
6940 if and only if there is no implicit conversion from T1 to T2. */
6943 casts_away_constness_r (tree *t1, tree *t2)
6948 /* [expr.const.cast]
6950 For multi-level pointer to members and multi-level mixed pointers
6951 and pointers to members (conv.qual), the "member" aspect of a
6952 pointer to member level is ignored when determining if a const
6953 cv-qualifier has been cast away. */
6954 /* [expr.const.cast]
6956 For two pointer types:
6958 X1 is T1cv1,1 * ... cv1,N * where T1 is not a pointer type
6959 X2 is T2cv2,1 * ... cv2,M * where T2 is not a pointer type
6962 casting from X1 to X2 casts away constness if, for a non-pointer
6963 type T there does not exist an implicit conversion (clause
6966 Tcv1,(N-K+1) * cv1,(N-K+2) * ... cv1,N *
6970 Tcv2,(M-K+1) * cv2,(M-K+2) * ... cv2,M *. */
6971 if ((!TYPE_PTR_P (*t1) && !TYPE_PTRMEM_P (*t1))
6972 || (!TYPE_PTR_P (*t2) && !TYPE_PTRMEM_P (*t2)))
6974 *t1 = cp_build_qualified_type (void_type_node,
6975 cp_type_quals (*t1));
6976 *t2 = cp_build_qualified_type (void_type_node,
6977 cp_type_quals (*t2));
6981 quals1 = cp_type_quals (*t1);
6982 quals2 = cp_type_quals (*t2);
6984 if (TYPE_PTRMEM_P (*t1))
6985 *t1 = TYPE_PTRMEM_POINTED_TO_TYPE (*t1);
6987 *t1 = TREE_TYPE (*t1);
6988 if (TYPE_PTRMEM_P (*t2))
6989 *t2 = TYPE_PTRMEM_POINTED_TO_TYPE (*t2);
6991 *t2 = TREE_TYPE (*t2);
6993 casts_away_constness_r (t1, t2);
6994 *t1 = build_pointer_type (*t1);
6995 *t2 = build_pointer_type (*t2);
6996 *t1 = cp_build_qualified_type (*t1, quals1);
6997 *t2 = cp_build_qualified_type (*t2, quals2);
7000 /* Returns nonzero if casting from TYPE1 to TYPE2 casts away
7004 casts_away_constness (tree t1, tree t2)
7006 if (TREE_CODE (t2) == REFERENCE_TYPE)
7008 /* [expr.const.cast]
7010 Casting from an lvalue of type T1 to an lvalue of type T2
7011 using a reference cast casts away constness if a cast from an
7012 rvalue of type "pointer to T1" to the type "pointer to T2"
7013 casts away constness. */
7014 t1 = (TREE_CODE (t1) == REFERENCE_TYPE ? TREE_TYPE (t1) : t1);
7015 return casts_away_constness (build_pointer_type (t1),
7016 build_pointer_type (TREE_TYPE (t2)));
7019 if (TYPE_PTRMEM_P (t1) && TYPE_PTRMEM_P (t2))
7020 /* [expr.const.cast]
7022 Casting from an rvalue of type "pointer to data member of X
7023 of type T1" to the type "pointer to data member of Y of type
7024 T2" casts away constness if a cast from an rvalue of type
7025 "pointer to T1" to the type "pointer to T2" casts away
7027 return casts_away_constness
7028 (build_pointer_type (TYPE_PTRMEM_POINTED_TO_TYPE (t1)),
7029 build_pointer_type (TYPE_PTRMEM_POINTED_TO_TYPE (t2)));
7031 /* Casting away constness is only something that makes sense for
7032 pointer or reference types. */
7033 if (TREE_CODE (t1) != POINTER_TYPE
7034 || TREE_CODE (t2) != POINTER_TYPE)
7037 /* Top-level qualifiers don't matter. */
7038 t1 = TYPE_MAIN_VARIANT (t1);
7039 t2 = TYPE_MAIN_VARIANT (t2);
7040 casts_away_constness_r (&t1, &t2);
7041 if (!can_convert (t2, t1))
7047 /* If T is a REFERENCE_TYPE return the type to which T refers.
7048 Otherwise, return T itself. */
7051 non_reference (tree t)
7053 if (TREE_CODE (t) == REFERENCE_TYPE)
7059 /* Return nonzero if REF is an lvalue valid for this language;
7060 otherwise, print an error message and return zero. USE says
7061 how the lvalue is being used and so selects the error message. */
7064 lvalue_or_else (tree ref, enum lvalue_use use)
7066 int win = lvalue_p (ref);