1 /* Build expressions with type checking for C++ compiler.
2 Copyright (C) 1987, 1988, 1989, 1992, 1993, 1994, 1995, 1996, 1997, 1998,
3 1999, 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008
4 Free Software Foundation, Inc.
5 Hacked by Michael Tiemann (tiemann@cygnus.com)
7 This file is part of GCC.
9 GCC is free software; you can redistribute it and/or modify
10 it under the terms of the GNU General Public License as published by
11 the Free Software Foundation; either version 3, or (at your option)
14 GCC is distributed in the hope that it will be useful,
15 but WITHOUT ANY WARRANTY; without even the implied warranty of
16 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
17 GNU General Public License for more details.
19 You should have received a copy of the GNU General Public License
20 along with GCC; see the file COPYING3. If not see
21 <http://www.gnu.org/licenses/>. */
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 delta_from_ptrmemfunc (tree);
50 static tree convert_for_assignment (tree, tree, const char *, tree, int,
52 static tree cp_pointer_int_sum (enum tree_code, tree, tree);
53 static tree rationalize_conditional_expr (enum tree_code, tree,
55 static int comp_ptr_ttypes_real (tree, tree, int);
56 static bool comp_except_types (tree, tree, bool);
57 static bool comp_array_types (const_tree, const_tree, bool);
58 static tree pointer_diff (tree, tree, tree);
59 static tree get_delta_difference (tree, tree, bool, bool);
60 static void casts_away_constness_r (tree *, tree *);
61 static bool casts_away_constness (tree, tree);
62 static void maybe_warn_about_returning_address_of_local (tree);
63 static tree lookup_destructor (tree, tree, tree);
64 static int convert_arguments (int, tree *, tree, tree, tree, int,
67 /* Do `exp = require_complete_type (exp);' to make sure exp
68 does not have an incomplete type. (That includes void types.)
69 Returns the error_mark_node if the VALUE does not have
70 complete type when this function returns. */
73 require_complete_type (tree value)
77 if (processing_template_decl || value == error_mark_node)
80 if (TREE_CODE (value) == OVERLOAD)
81 type = unknown_type_node;
83 type = TREE_TYPE (value);
85 if (type == error_mark_node)
86 return error_mark_node;
88 /* First, detect a valid value with a complete type. */
89 if (COMPLETE_TYPE_P (type))
92 if (complete_type_or_else (type, value))
95 return error_mark_node;
98 /* Try to complete TYPE, if it is incomplete. For example, if TYPE is
99 a template instantiation, do the instantiation. Returns TYPE,
100 whether or not it could be completed, unless something goes
101 horribly wrong, in which case the error_mark_node is returned. */
104 complete_type (tree type)
106 if (type == NULL_TREE)
107 /* Rather than crash, we return something sure to cause an error
109 return error_mark_node;
111 if (type == error_mark_node || COMPLETE_TYPE_P (type))
113 else if (TREE_CODE (type) == ARRAY_TYPE && TYPE_DOMAIN (type))
115 tree t = complete_type (TREE_TYPE (type));
116 unsigned int needs_constructing, has_nontrivial_dtor;
117 if (COMPLETE_TYPE_P (t) && !dependent_type_p (type))
120 = TYPE_NEEDS_CONSTRUCTING (TYPE_MAIN_VARIANT (t));
122 = TYPE_HAS_NONTRIVIAL_DESTRUCTOR (TYPE_MAIN_VARIANT (t));
123 for (t = TYPE_MAIN_VARIANT (type); t; t = TYPE_NEXT_VARIANT (t))
125 TYPE_NEEDS_CONSTRUCTING (t) = needs_constructing;
126 TYPE_HAS_NONTRIVIAL_DESTRUCTOR (t) = has_nontrivial_dtor;
129 else if (CLASS_TYPE_P (type) && CLASSTYPE_TEMPLATE_INSTANTIATION (type))
130 instantiate_class_template (TYPE_MAIN_VARIANT (type));
135 /* Like complete_type, but issue an error if the TYPE cannot be completed.
136 VALUE is used for informative diagnostics.
137 Returns NULL_TREE if the type cannot be made complete. */
140 complete_type_or_else (tree type, tree value)
142 type = complete_type (type);
143 if (type == error_mark_node)
144 /* We already issued an error. */
146 else if (!COMPLETE_TYPE_P (type))
148 cxx_incomplete_type_diagnostic (value, type, DK_ERROR);
155 /* Return truthvalue of whether type of EXP is instantiated. */
158 type_unknown_p (const_tree exp)
160 return (TREE_CODE (exp) == TREE_LIST
161 || TREE_TYPE (exp) == unknown_type_node);
165 /* Return the common type of two parameter lists.
166 We assume that comptypes has already been done and returned 1;
167 if that isn't so, this may crash.
169 As an optimization, free the space we allocate if the parameter
170 lists are already common. */
173 commonparms (tree p1, tree p2)
175 tree oldargs = p1, newargs, n;
179 len = list_length (p1);
180 newargs = tree_last (p1);
182 if (newargs == void_list_node)
191 newargs = tree_cons (NULL_TREE, NULL_TREE, newargs);
196 p1 = TREE_CHAIN (p1), p2 = TREE_CHAIN (p2), n = TREE_CHAIN (n), i++)
198 if (TREE_PURPOSE (p1) && !TREE_PURPOSE (p2))
200 TREE_PURPOSE (n) = TREE_PURPOSE (p1);
203 else if (! TREE_PURPOSE (p1))
205 if (TREE_PURPOSE (p2))
207 TREE_PURPOSE (n) = TREE_PURPOSE (p2);
213 if (1 != simple_cst_equal (TREE_PURPOSE (p1), TREE_PURPOSE (p2)))
215 TREE_PURPOSE (n) = TREE_PURPOSE (p2);
217 if (TREE_VALUE (p1) != TREE_VALUE (p2))
220 TREE_VALUE (n) = merge_types (TREE_VALUE (p1), TREE_VALUE (p2));
223 TREE_VALUE (n) = TREE_VALUE (p1);
231 /* Given a type, perhaps copied for a typedef,
232 find the "original" version of it. */
234 original_type (tree t)
236 int quals = cp_type_quals (t);
237 while (t != error_mark_node
238 && TYPE_NAME (t) != NULL_TREE)
240 tree x = TYPE_NAME (t);
241 if (TREE_CODE (x) != TYPE_DECL)
243 x = DECL_ORIGINAL_TYPE (x);
248 return cp_build_qualified_type (t, quals);
251 /* T1 and T2 are arithmetic or enumeration types. Return the type
252 that will result from the "usual arithmetic conversions" on T1 and
253 T2 as described in [expr]. */
256 type_after_usual_arithmetic_conversions (tree t1, tree t2)
258 enum tree_code code1 = TREE_CODE (t1);
259 enum tree_code code2 = TREE_CODE (t2);
262 /* FIXME: Attributes. */
263 gcc_assert (ARITHMETIC_TYPE_P (t1)
264 || TREE_CODE (t1) == VECTOR_TYPE
265 || UNSCOPED_ENUM_P (t1));
266 gcc_assert (ARITHMETIC_TYPE_P (t2)
267 || TREE_CODE (t2) == VECTOR_TYPE
268 || UNSCOPED_ENUM_P (t2));
270 /* In what follows, we slightly generalize the rules given in [expr] so
271 as to deal with `long long' and `complex'. First, merge the
273 attributes = (*targetm.merge_type_attributes) (t1, t2);
275 /* If one type is complex, form the common type of the non-complex
276 components, then make that complex. Use T1 or T2 if it is the
278 if (code1 == COMPLEX_TYPE || code2 == COMPLEX_TYPE)
280 tree subtype1 = code1 == COMPLEX_TYPE ? TREE_TYPE (t1) : t1;
281 tree subtype2 = code2 == COMPLEX_TYPE ? TREE_TYPE (t2) : t2;
283 = type_after_usual_arithmetic_conversions (subtype1, subtype2);
285 if (code1 == COMPLEX_TYPE && TREE_TYPE (t1) == subtype)
286 return build_type_attribute_variant (t1, attributes);
287 else if (code2 == COMPLEX_TYPE && TREE_TYPE (t2) == subtype)
288 return build_type_attribute_variant (t2, attributes);
290 return build_type_attribute_variant (build_complex_type (subtype),
294 if (code1 == VECTOR_TYPE)
296 /* When we get here we should have two vectors of the same size.
297 Just prefer the unsigned one if present. */
298 if (TYPE_UNSIGNED (t1))
299 return build_type_attribute_variant (t1, attributes);
301 return build_type_attribute_variant (t2, attributes);
304 /* If only one is real, use it as the result. */
305 if (code1 == REAL_TYPE && code2 != REAL_TYPE)
306 return build_type_attribute_variant (t1, attributes);
307 if (code2 == REAL_TYPE && code1 != REAL_TYPE)
308 return build_type_attribute_variant (t2, attributes);
310 /* Perform the integral promotions. */
311 if (code1 != REAL_TYPE)
313 t1 = type_promotes_to (t1);
314 t2 = type_promotes_to (t2);
317 /* Both real or both integers; use the one with greater precision. */
318 if (TYPE_PRECISION (t1) > TYPE_PRECISION (t2))
319 return build_type_attribute_variant (t1, attributes);
320 else if (TYPE_PRECISION (t2) > TYPE_PRECISION (t1))
321 return build_type_attribute_variant (t2, attributes);
323 /* The types are the same; no need to do anything fancy. */
324 if (TYPE_MAIN_VARIANT (t1) == TYPE_MAIN_VARIANT (t2))
325 return build_type_attribute_variant (t1, attributes);
327 if (code1 != REAL_TYPE)
329 /* If one is unsigned long long, then convert the other to unsigned
331 if (same_type_p (TYPE_MAIN_VARIANT (t1), long_long_unsigned_type_node)
332 || same_type_p (TYPE_MAIN_VARIANT (t2), long_long_unsigned_type_node))
333 return build_type_attribute_variant (long_long_unsigned_type_node,
335 /* If one is a long long, and the other is an unsigned long, and
336 long long can represent all the values of an unsigned long, then
337 convert to a long long. Otherwise, convert to an unsigned long
338 long. Otherwise, if either operand is long long, convert the
341 Since we're here, we know the TYPE_PRECISION is the same;
342 therefore converting to long long cannot represent all the values
343 of an unsigned long, so we choose unsigned long long in that
345 if (same_type_p (TYPE_MAIN_VARIANT (t1), long_long_integer_type_node)
346 || same_type_p (TYPE_MAIN_VARIANT (t2), long_long_integer_type_node))
348 tree t = ((TYPE_UNSIGNED (t1) || TYPE_UNSIGNED (t2))
349 ? long_long_unsigned_type_node
350 : long_long_integer_type_node);
351 return build_type_attribute_variant (t, attributes);
354 /* Go through the same procedure, but for longs. */
355 if (same_type_p (TYPE_MAIN_VARIANT (t1), long_unsigned_type_node)
356 || same_type_p (TYPE_MAIN_VARIANT (t2), long_unsigned_type_node))
357 return build_type_attribute_variant (long_unsigned_type_node,
359 if (same_type_p (TYPE_MAIN_VARIANT (t1), long_integer_type_node)
360 || same_type_p (TYPE_MAIN_VARIANT (t2), long_integer_type_node))
362 tree t = ((TYPE_UNSIGNED (t1) || TYPE_UNSIGNED (t2))
363 ? long_unsigned_type_node : long_integer_type_node);
364 return build_type_attribute_variant (t, attributes);
366 /* Otherwise prefer the unsigned one. */
367 if (TYPE_UNSIGNED (t1))
368 return build_type_attribute_variant (t1, attributes);
370 return build_type_attribute_variant (t2, attributes);
374 if (same_type_p (TYPE_MAIN_VARIANT (t1), long_double_type_node)
375 || same_type_p (TYPE_MAIN_VARIANT (t2), long_double_type_node))
376 return build_type_attribute_variant (long_double_type_node,
378 if (same_type_p (TYPE_MAIN_VARIANT (t1), double_type_node)
379 || same_type_p (TYPE_MAIN_VARIANT (t2), double_type_node))
380 return build_type_attribute_variant (double_type_node,
382 if (same_type_p (TYPE_MAIN_VARIANT (t1), float_type_node)
383 || same_type_p (TYPE_MAIN_VARIANT (t2), float_type_node))
384 return build_type_attribute_variant (float_type_node,
387 /* Two floating-point types whose TYPE_MAIN_VARIANTs are none of
388 the standard C++ floating-point types. Logic earlier in this
389 function has already eliminated the possibility that
390 TYPE_PRECISION (t2) != TYPE_PRECISION (t1), so there's no
391 compelling reason to choose one or the other. */
392 return build_type_attribute_variant (t1, attributes);
396 /* Subroutine of composite_pointer_type to implement the recursive
397 case. See that function for documentation fo the parameters. */
400 composite_pointer_type_r (tree t1, tree t2, const char* location,
401 tsubst_flags_t complain)
408 /* Determine the types pointed to by T1 and T2. */
409 if (TREE_CODE (t1) == POINTER_TYPE)
411 pointee1 = TREE_TYPE (t1);
412 pointee2 = TREE_TYPE (t2);
416 pointee1 = TYPE_PTRMEM_POINTED_TO_TYPE (t1);
417 pointee2 = TYPE_PTRMEM_POINTED_TO_TYPE (t2);
422 Otherwise, the composite pointer type is a pointer type
423 similar (_conv.qual_) to the type of one of the operands,
424 with a cv-qualification signature (_conv.qual_) that is the
425 union of the cv-qualification signatures of the operand
427 if (same_type_ignoring_top_level_qualifiers_p (pointee1, pointee2))
428 result_type = pointee1;
429 else if ((TREE_CODE (pointee1) == POINTER_TYPE
430 && TREE_CODE (pointee2) == POINTER_TYPE)
431 || (TYPE_PTR_TO_MEMBER_P (pointee1)
432 && TYPE_PTR_TO_MEMBER_P (pointee2)))
433 result_type = composite_pointer_type_r (pointee1, pointee2, location,
437 if (complain & tf_error)
438 permerror (input_location, "%s between distinct pointer types %qT and %qT "
441 result_type = void_type_node;
443 result_type = cp_build_qualified_type (result_type,
444 (cp_type_quals (pointee1)
445 | cp_type_quals (pointee2)));
446 /* If the original types were pointers to members, so is the
448 if (TYPE_PTR_TO_MEMBER_P (t1))
450 if (!same_type_p (TYPE_PTRMEM_CLASS_TYPE (t1),
451 TYPE_PTRMEM_CLASS_TYPE (t2))
452 && (complain & tf_error))
453 permerror (input_location, "%s between distinct pointer types %qT and %qT "
456 result_type = build_ptrmem_type (TYPE_PTRMEM_CLASS_TYPE (t1),
460 result_type = build_pointer_type (result_type);
462 /* Merge the attributes. */
463 attributes = (*targetm.merge_type_attributes) (t1, t2);
464 return build_type_attribute_variant (result_type, attributes);
467 /* Return the composite pointer type (see [expr.rel]) for T1 and T2.
468 ARG1 and ARG2 are the values with those types. The LOCATION is a
469 string describing the current location, in case an error occurs.
471 This routine also implements the computation of a common type for
472 pointers-to-members as per [expr.eq]. */
475 composite_pointer_type (tree t1, tree t2, tree arg1, tree arg2,
476 const char* location, tsubst_flags_t complain)
483 If one operand is a null pointer constant, the composite pointer
484 type is the type of the other operand. */
485 if (null_ptr_cst_p (arg1))
487 if (null_ptr_cst_p (arg2))
494 If one of the operands has type "pointer to cv1 void*", then
495 the other has type "pointer to cv2T", and the composite pointer
496 type is "pointer to cv12 void", where cv12 is the union of cv1
499 If either type is a pointer to void, make sure it is T1. */
500 if (TREE_CODE (t2) == POINTER_TYPE && VOID_TYPE_P (TREE_TYPE (t2)))
508 /* Now, if T1 is a pointer to void, merge the qualifiers. */
509 if (TREE_CODE (t1) == POINTER_TYPE && VOID_TYPE_P (TREE_TYPE (t1)))
514 if (TYPE_PTRFN_P (t2) && (complain & tf_error))
515 pedwarn (input_location, OPT_pedantic, "ISO C++ forbids %s "
516 "between pointer of type %<void *%> and pointer-to-function",
519 = cp_build_qualified_type (void_type_node,
520 (cp_type_quals (TREE_TYPE (t1))
521 | cp_type_quals (TREE_TYPE (t2))));
522 result_type = build_pointer_type (result_type);
523 /* Merge the attributes. */
524 attributes = (*targetm.merge_type_attributes) (t1, t2);
525 return build_type_attribute_variant (result_type, attributes);
528 if (c_dialect_objc () && TREE_CODE (t1) == POINTER_TYPE
529 && TREE_CODE (t2) == POINTER_TYPE)
531 if (objc_compare_types (t1, t2, -3, NULL_TREE))
535 /* [expr.eq] permits the application of a pointer conversion to
536 bring the pointers to a common type. */
537 if (TREE_CODE (t1) == POINTER_TYPE && TREE_CODE (t2) == POINTER_TYPE
538 && CLASS_TYPE_P (TREE_TYPE (t1))
539 && CLASS_TYPE_P (TREE_TYPE (t2))
540 && !same_type_ignoring_top_level_qualifiers_p (TREE_TYPE (t1),
543 class1 = TREE_TYPE (t1);
544 class2 = TREE_TYPE (t2);
546 if (DERIVED_FROM_P (class1, class2))
547 t2 = (build_pointer_type
548 (cp_build_qualified_type (class1, TYPE_QUALS (class2))));
549 else if (DERIVED_FROM_P (class2, class1))
550 t1 = (build_pointer_type
551 (cp_build_qualified_type (class2, TYPE_QUALS (class1))));
554 if (complain & tf_error)
555 error ("%s between distinct pointer types %qT and %qT "
556 "lacks a cast", location, t1, t2);
557 return error_mark_node;
560 /* [expr.eq] permits the application of a pointer-to-member
561 conversion to change the class type of one of the types. */
562 else if (TYPE_PTR_TO_MEMBER_P (t1)
563 && !same_type_p (TYPE_PTRMEM_CLASS_TYPE (t1),
564 TYPE_PTRMEM_CLASS_TYPE (t2)))
566 class1 = TYPE_PTRMEM_CLASS_TYPE (t1);
567 class2 = TYPE_PTRMEM_CLASS_TYPE (t2);
569 if (DERIVED_FROM_P (class1, class2))
570 t1 = build_ptrmem_type (class2, TYPE_PTRMEM_POINTED_TO_TYPE (t1));
571 else if (DERIVED_FROM_P (class2, class1))
572 t2 = build_ptrmem_type (class1, TYPE_PTRMEM_POINTED_TO_TYPE (t2));
575 if (complain & tf_error)
576 error ("%s between distinct pointer-to-member types %qT and %qT "
577 "lacks a cast", location, t1, t2);
578 return error_mark_node;
582 return composite_pointer_type_r (t1, t2, location, complain);
585 /* Return the merged type of two types.
586 We assume that comptypes has already been done and returned 1;
587 if that isn't so, this may crash.
589 This just combines attributes and default arguments; any other
590 differences would cause the two types to compare unalike. */
593 merge_types (tree t1, tree t2)
595 enum tree_code code1;
596 enum tree_code code2;
599 /* Save time if the two types are the same. */
602 if (original_type (t1) == original_type (t2))
605 /* If one type is nonsense, use the other. */
606 if (t1 == error_mark_node)
608 if (t2 == error_mark_node)
611 /* Merge the attributes. */
612 attributes = (*targetm.merge_type_attributes) (t1, t2);
614 if (TYPE_PTRMEMFUNC_P (t1))
615 t1 = TYPE_PTRMEMFUNC_FN_TYPE (t1);
616 if (TYPE_PTRMEMFUNC_P (t2))
617 t2 = TYPE_PTRMEMFUNC_FN_TYPE (t2);
619 code1 = TREE_CODE (t1);
620 code2 = TREE_CODE (t2);
626 /* For two pointers, do this recursively on the target type. */
628 tree target = merge_types (TREE_TYPE (t1), TREE_TYPE (t2));
629 int quals = cp_type_quals (t1);
631 if (code1 == POINTER_TYPE)
632 t1 = build_pointer_type (target);
634 t1 = cp_build_reference_type (target, TYPE_REF_IS_RVALUE (t1));
635 t1 = build_type_attribute_variant (t1, attributes);
636 t1 = cp_build_qualified_type (t1, quals);
638 if (TREE_CODE (target) == METHOD_TYPE)
639 t1 = build_ptrmemfunc_type (t1);
648 quals = cp_type_quals (t1);
649 pointee = merge_types (TYPE_PTRMEM_POINTED_TO_TYPE (t1),
650 TYPE_PTRMEM_POINTED_TO_TYPE (t2));
651 t1 = build_ptrmem_type (TYPE_PTRMEM_CLASS_TYPE (t1),
653 t1 = cp_build_qualified_type (t1, quals);
659 tree elt = merge_types (TREE_TYPE (t1), TREE_TYPE (t2));
660 /* Save space: see if the result is identical to one of the args. */
661 if (elt == TREE_TYPE (t1) && TYPE_DOMAIN (t1))
662 return build_type_attribute_variant (t1, attributes);
663 if (elt == TREE_TYPE (t2) && TYPE_DOMAIN (t2))
664 return build_type_attribute_variant (t2, attributes);
665 /* Merge the element types, and have a size if either arg has one. */
666 t1 = build_cplus_array_type
667 (elt, TYPE_DOMAIN (TYPE_DOMAIN (t1) ? t1 : t2));
672 /* Function types: prefer the one that specified arg types.
673 If both do, merge the arg types. Also merge the return types. */
675 tree valtype = merge_types (TREE_TYPE (t1), TREE_TYPE (t2));
676 tree p1 = TYPE_ARG_TYPES (t1);
677 tree p2 = TYPE_ARG_TYPES (t2);
680 /* Save space: see if the result is identical to one of the args. */
681 if (valtype == TREE_TYPE (t1) && ! p2)
682 return cp_build_type_attribute_variant (t1, attributes);
683 if (valtype == TREE_TYPE (t2) && ! p1)
684 return cp_build_type_attribute_variant (t2, attributes);
686 /* Simple way if one arg fails to specify argument types. */
687 if (p1 == NULL_TREE || TREE_VALUE (p1) == void_type_node)
689 rval = build_function_type (valtype, p2);
690 if ((raises = TYPE_RAISES_EXCEPTIONS (t2)))
691 rval = build_exception_variant (rval, raises);
692 return cp_build_type_attribute_variant (rval, attributes);
694 raises = TYPE_RAISES_EXCEPTIONS (t1);
695 if (p2 == NULL_TREE || TREE_VALUE (p2) == void_type_node)
697 rval = build_function_type (valtype, p1);
699 rval = build_exception_variant (rval, raises);
700 return cp_build_type_attribute_variant (rval, attributes);
703 rval = build_function_type (valtype, commonparms (p1, p2));
704 t1 = build_exception_variant (rval, raises);
710 /* Get this value the long way, since TYPE_METHOD_BASETYPE
711 is just the main variant of this. */
712 tree basetype = TREE_TYPE (TREE_VALUE (TYPE_ARG_TYPES (t2)));
713 tree raises = TYPE_RAISES_EXCEPTIONS (t1);
716 /* If this was a member function type, get back to the
717 original type of type member function (i.e., without
718 the class instance variable up front. */
719 t1 = build_function_type (TREE_TYPE (t1),
720 TREE_CHAIN (TYPE_ARG_TYPES (t1)));
721 t2 = build_function_type (TREE_TYPE (t2),
722 TREE_CHAIN (TYPE_ARG_TYPES (t2)));
723 t3 = merge_types (t1, t2);
724 t3 = build_method_type_directly (basetype, TREE_TYPE (t3),
725 TYPE_ARG_TYPES (t3));
726 t1 = build_exception_variant (t3, raises);
731 /* There is no need to merge attributes into a TYPENAME_TYPE.
732 When the type is instantiated it will have whatever
733 attributes result from the instantiation. */
739 if (attribute_list_equal (TYPE_ATTRIBUTES (t1), attributes))
741 else if (attribute_list_equal (TYPE_ATTRIBUTES (t2), attributes))
744 return cp_build_type_attribute_variant (t1, attributes);
747 /* Return the common type of two types.
748 We assume that comptypes has already been done and returned 1;
749 if that isn't so, this may crash.
751 This is the type for the result of most arithmetic operations
752 if the operands have the given two types. */
755 common_type (tree t1, tree t2)
757 enum tree_code code1;
758 enum tree_code code2;
760 /* If one type is nonsense, bail. */
761 if (t1 == error_mark_node || t2 == error_mark_node)
762 return error_mark_node;
764 code1 = TREE_CODE (t1);
765 code2 = TREE_CODE (t2);
767 if ((ARITHMETIC_TYPE_P (t1) || UNSCOPED_ENUM_P (t1)
768 || code1 == VECTOR_TYPE)
769 && (ARITHMETIC_TYPE_P (t2) || UNSCOPED_ENUM_P (t2)
770 || code2 == VECTOR_TYPE))
771 return type_after_usual_arithmetic_conversions (t1, t2);
773 else if ((TYPE_PTR_P (t1) && TYPE_PTR_P (t2))
774 || (TYPE_PTRMEM_P (t1) && TYPE_PTRMEM_P (t2))
775 || (TYPE_PTRMEMFUNC_P (t1) && TYPE_PTRMEMFUNC_P (t2)))
776 return composite_pointer_type (t1, t2, error_mark_node, error_mark_node,
777 "conversion", tf_warning_or_error);
782 /* Compare two exception specifier types for exactness or subsetness, if
783 allowed. Returns false for mismatch, true for match (same, or
786 [except.spec] "If a class X ... objects of class X or any class publicly
787 and unambiguously derived from X. Similarly, if a pointer type Y * ...
788 exceptions of type Y * or that are pointers to any type publicly and
789 unambiguously derived from Y. Otherwise a function only allows exceptions
790 that have the same type ..."
791 This does not mention cv qualifiers and is different to what throw
792 [except.throw] and catch [except.catch] will do. They will ignore the
793 top level cv qualifiers, and allow qualifiers in the pointer to class
796 We implement the letter of the standard. */
799 comp_except_types (tree a, tree b, bool exact)
801 if (same_type_p (a, b))
805 if (cp_type_quals (a) || cp_type_quals (b))
808 if (TREE_CODE (a) == POINTER_TYPE
809 && TREE_CODE (b) == POINTER_TYPE)
813 if (cp_type_quals (a) || cp_type_quals (b))
817 if (TREE_CODE (a) != RECORD_TYPE
818 || TREE_CODE (b) != RECORD_TYPE)
821 if (PUBLICLY_UNIQUELY_DERIVED_P (a, b))
827 /* Return true if TYPE1 and TYPE2 are equivalent exception specifiers.
828 If EXACT is false, T2 can be stricter than T1 (according to 15.4/7),
829 otherwise it must be exact. Exception lists are unordered, but
830 we've already filtered out duplicates. Most lists will be in order,
831 we should try to make use of that. */
834 comp_except_specs (const_tree t1, const_tree t2, bool exact)
843 if (t1 == NULL_TREE) /* T1 is ... */
844 return t2 == NULL_TREE || !exact;
845 if (!TREE_VALUE (t1)) /* t1 is EMPTY */
846 return t2 != NULL_TREE && !TREE_VALUE (t2);
847 if (t2 == NULL_TREE) /* T2 is ... */
849 if (TREE_VALUE (t1) && !TREE_VALUE (t2)) /* T2 is EMPTY, T1 is not */
852 /* Neither set is ... or EMPTY, make sure each part of T2 is in T1.
853 Count how many we find, to determine exactness. For exact matching and
854 ordered T1, T2, this is an O(n) operation, otherwise its worst case is
856 for (base = t1; t2 != NULL_TREE; t2 = TREE_CHAIN (t2))
858 for (probe = base; probe != NULL_TREE; probe = TREE_CHAIN (probe))
860 tree a = TREE_VALUE (probe);
861 tree b = TREE_VALUE (t2);
863 if (comp_except_types (a, b, exact))
865 if (probe == base && exact)
866 base = TREE_CHAIN (probe);
871 if (probe == NULL_TREE)
874 return !exact || base == NULL_TREE || length == list_length (t1);
877 /* Compare the array types T1 and T2. ALLOW_REDECLARATION is true if
878 [] can match [size]. */
881 comp_array_types (const_tree t1, const_tree t2, bool allow_redeclaration)
890 /* The type of the array elements must be the same. */
891 if (!same_type_p (TREE_TYPE (t1), TREE_TYPE (t2)))
894 d1 = TYPE_DOMAIN (t1);
895 d2 = TYPE_DOMAIN (t2);
900 /* If one of the arrays is dimensionless, and the other has a
901 dimension, they are of different types. However, it is valid to
909 declarations for an array object can specify
910 array types that differ by the presence or absence of a major
911 array bound (_dcl.array_). */
913 return allow_redeclaration;
915 /* Check that the dimensions are the same. */
917 if (!cp_tree_equal (TYPE_MIN_VALUE (d1), TYPE_MIN_VALUE (d2)))
919 max1 = TYPE_MAX_VALUE (d1);
920 max2 = TYPE_MAX_VALUE (d2);
921 if (processing_template_decl && !abi_version_at_least (2)
922 && !value_dependent_expression_p (max1)
923 && !value_dependent_expression_p (max2))
925 /* With abi-1 we do not fold non-dependent array bounds, (and
926 consequently mangle them incorrectly). We must therefore
927 fold them here, to verify the domains have the same
933 if (!cp_tree_equal (max1, max2))
939 /* Subroutine in comptypes. */
942 structural_comptypes (tree t1, tree t2, int strict)
947 /* Suppress errors caused by previously reported errors. */
948 if (t1 == error_mark_node || t2 == error_mark_node)
951 gcc_assert (TYPE_P (t1) && TYPE_P (t2));
953 /* TYPENAME_TYPEs should be resolved if the qualifying scope is the
954 current instantiation. */
955 if (TREE_CODE (t1) == TYPENAME_TYPE)
956 t1 = resolve_typename_type (t1, /*only_current_p=*/true);
958 if (TREE_CODE (t2) == TYPENAME_TYPE)
959 t2 = resolve_typename_type (t2, /*only_current_p=*/true);
961 if (TYPE_PTRMEMFUNC_P (t1))
962 t1 = TYPE_PTRMEMFUNC_FN_TYPE (t1);
963 if (TYPE_PTRMEMFUNC_P (t2))
964 t2 = TYPE_PTRMEMFUNC_FN_TYPE (t2);
966 /* Different classes of types can't be compatible. */
967 if (TREE_CODE (t1) != TREE_CODE (t2))
970 /* Qualifiers must match. For array types, we will check when we
971 recur on the array element types. */
972 if (TREE_CODE (t1) != ARRAY_TYPE
973 && TYPE_QUALS (t1) != TYPE_QUALS (t2))
975 if (TYPE_FOR_JAVA (t1) != TYPE_FOR_JAVA (t2))
978 /* Allow for two different type nodes which have essentially the same
979 definition. Note that we already checked for equality of the type
980 qualifiers (just above). */
982 if (TREE_CODE (t1) != ARRAY_TYPE
983 && TYPE_MAIN_VARIANT (t1) == TYPE_MAIN_VARIANT (t2))
986 /* Compare the types. Break out if they could be the same. */
987 switch (TREE_CODE (t1))
991 /* All void and bool types are the same. */
995 case FIXED_POINT_TYPE:
997 /* With these nodes, we can't determine type equivalence by
998 looking at what is stored in the nodes themselves, because
999 two nodes might have different TYPE_MAIN_VARIANTs but still
1000 represent the same type. For example, wchar_t and int could
1001 have the same properties (TYPE_PRECISION, TYPE_MIN_VALUE,
1002 TYPE_MAX_VALUE, etc.), but have different TYPE_MAIN_VARIANTs
1003 and are distinct types. On the other hand, int and the
1006 typedef int INT __attribute((may_alias));
1008 have identical properties, different TYPE_MAIN_VARIANTs, but
1009 represent the same type. The canonical type system keeps
1010 track of equivalence in this case, so we fall back on it. */
1011 return TYPE_CANONICAL (t1) == TYPE_CANONICAL (t2);
1013 case TEMPLATE_TEMPLATE_PARM:
1014 case BOUND_TEMPLATE_TEMPLATE_PARM:
1015 if (TEMPLATE_TYPE_IDX (t1) != TEMPLATE_TYPE_IDX (t2)
1016 || TEMPLATE_TYPE_LEVEL (t1) != TEMPLATE_TYPE_LEVEL (t2)
1017 || (TEMPLATE_TYPE_PARAMETER_PACK (t1)
1018 != TEMPLATE_TYPE_PARAMETER_PACK (t2)))
1020 if (!comp_template_parms
1021 (DECL_TEMPLATE_PARMS (TEMPLATE_TEMPLATE_PARM_TEMPLATE_DECL (t1)),
1022 DECL_TEMPLATE_PARMS (TEMPLATE_TEMPLATE_PARM_TEMPLATE_DECL (t2))))
1024 if (TREE_CODE (t1) == TEMPLATE_TEMPLATE_PARM)
1026 /* Don't check inheritance. */
1027 strict = COMPARE_STRICT;
1032 if (TYPE_TEMPLATE_INFO (t1) && TYPE_TEMPLATE_INFO (t2)
1033 && (TYPE_TI_TEMPLATE (t1) == TYPE_TI_TEMPLATE (t2)
1034 || TREE_CODE (t1) == BOUND_TEMPLATE_TEMPLATE_PARM)
1035 && comp_template_args (TYPE_TI_ARGS (t1), TYPE_TI_ARGS (t2)))
1038 if ((strict & COMPARE_BASE) && DERIVED_FROM_P (t1, t2))
1040 else if ((strict & COMPARE_DERIVED) && DERIVED_FROM_P (t2, t1))
1046 if (!comptypes (TYPE_OFFSET_BASETYPE (t1), TYPE_OFFSET_BASETYPE (t2),
1047 strict & ~COMPARE_REDECLARATION))
1049 if (!same_type_p (TREE_TYPE (t1), TREE_TYPE (t2)))
1053 case REFERENCE_TYPE:
1054 if (TYPE_REF_IS_RVALUE (t1) != TYPE_REF_IS_RVALUE (t2))
1056 /* fall through to checks for pointer types */
1059 if (TYPE_MODE (t1) != TYPE_MODE (t2)
1060 || TYPE_REF_CAN_ALIAS_ALL (t1) != TYPE_REF_CAN_ALIAS_ALL (t2)
1061 || !same_type_p (TREE_TYPE (t1), TREE_TYPE (t2)))
1067 if (!same_type_p (TREE_TYPE (t1), TREE_TYPE (t2)))
1069 if (!compparms (TYPE_ARG_TYPES (t1), TYPE_ARG_TYPES (t2)))
1074 /* Target types must match incl. qualifiers. */
1075 if (!comp_array_types (t1, t2, !!(strict & COMPARE_REDECLARATION)))
1079 case TEMPLATE_TYPE_PARM:
1080 if (TEMPLATE_TYPE_IDX (t1) != TEMPLATE_TYPE_IDX (t2)
1081 || TEMPLATE_TYPE_LEVEL (t1) != TEMPLATE_TYPE_LEVEL (t2)
1082 || (TEMPLATE_TYPE_PARAMETER_PACK (t1)
1083 != TEMPLATE_TYPE_PARAMETER_PACK (t2)))
1088 if (!cp_tree_equal (TYPENAME_TYPE_FULLNAME (t1),
1089 TYPENAME_TYPE_FULLNAME (t2)))
1091 if (!same_type_p (TYPE_CONTEXT (t1), TYPE_CONTEXT (t2)))
1095 case UNBOUND_CLASS_TEMPLATE:
1096 if (!cp_tree_equal (TYPE_IDENTIFIER (t1), TYPE_IDENTIFIER (t2)))
1098 if (!same_type_p (TYPE_CONTEXT (t1), TYPE_CONTEXT (t2)))
1103 if (!same_type_p (TREE_TYPE (t1), TREE_TYPE (t2)))
1108 if (TYPE_VECTOR_SUBPARTS (t1) != TYPE_VECTOR_SUBPARTS (t2)
1109 || !same_type_p (TREE_TYPE (t1), TREE_TYPE (t2)))
1113 case TYPE_PACK_EXPANSION:
1114 return same_type_p (PACK_EXPANSION_PATTERN (t1),
1115 PACK_EXPANSION_PATTERN (t2));
1118 if (DECLTYPE_TYPE_ID_EXPR_OR_MEMBER_ACCESS_P (t1)
1119 != DECLTYPE_TYPE_ID_EXPR_OR_MEMBER_ACCESS_P (t2)
1120 || !cp_tree_equal (DECLTYPE_TYPE_EXPR (t1),
1121 DECLTYPE_TYPE_EXPR (t2)))
1129 /* If we get here, we know that from a target independent POV the
1130 types are the same. Make sure the target attributes are also
1132 return targetm.comp_type_attributes (t1, t2);
1135 /* Return true if T1 and T2 are related as allowed by STRICT. STRICT
1136 is a bitwise-or of the COMPARE_* flags. */
1139 comptypes (tree t1, tree t2, int strict)
1141 if (strict == COMPARE_STRICT)
1146 if (t1 == error_mark_node || t2 == error_mark_node)
1149 if (TYPE_STRUCTURAL_EQUALITY_P (t1) || TYPE_STRUCTURAL_EQUALITY_P (t2))
1150 /* At least one of the types requires structural equality, so
1151 perform a deep check. */
1152 return structural_comptypes (t1, t2, strict);
1154 #ifdef ENABLE_CHECKING
1155 if (USE_CANONICAL_TYPES)
1157 bool result = structural_comptypes (t1, t2, strict);
1159 if (result && TYPE_CANONICAL (t1) != TYPE_CANONICAL (t2))
1160 /* The two types are structurally equivalent, but their
1161 canonical types were different. This is a failure of the
1162 canonical type propagation code.*/
1164 ("canonical types differ for identical types %T and %T",
1166 else if (!result && TYPE_CANONICAL (t1) == TYPE_CANONICAL (t2))
1167 /* Two types are structurally different, but the canonical
1168 types are the same. This means we were over-eager in
1169 assigning canonical types. */
1171 ("same canonical type node for different types %T and %T",
1177 if (USE_CANONICAL_TYPES)
1178 return TYPE_CANONICAL (t1) == TYPE_CANONICAL (t2);
1181 return structural_comptypes (t1, t2, strict);
1183 else if (strict == COMPARE_STRUCTURAL)
1184 return structural_comptypes (t1, t2, COMPARE_STRICT);
1186 return structural_comptypes (t1, t2, strict);
1189 /* Returns 1 if TYPE1 is at least as qualified as TYPE2. */
1192 at_least_as_qualified_p (const_tree type1, const_tree type2)
1194 int q1 = cp_type_quals (type1);
1195 int q2 = cp_type_quals (type2);
1197 /* All qualifiers for TYPE2 must also appear in TYPE1. */
1198 return (q1 & q2) == q2;
1201 /* Returns 1 if TYPE1 is more cv-qualified than TYPE2, -1 if TYPE2 is
1202 more cv-qualified that TYPE1, and 0 otherwise. */
1205 comp_cv_qualification (const_tree type1, const_tree type2)
1207 int q1 = cp_type_quals (type1);
1208 int q2 = cp_type_quals (type2);
1213 if ((q1 & q2) == q2)
1215 else if ((q1 & q2) == q1)
1221 /* Returns 1 if the cv-qualification signature of TYPE1 is a proper
1222 subset of the cv-qualification signature of TYPE2, and the types
1223 are similar. Returns -1 if the other way 'round, and 0 otherwise. */
1226 comp_cv_qual_signature (tree type1, tree type2)
1228 if (comp_ptr_ttypes_real (type2, type1, -1))
1230 else if (comp_ptr_ttypes_real (type1, type2, -1))
1236 /* Subroutines of `comptypes'. */
1238 /* Return true if two parameter type lists PARMS1 and PARMS2 are
1239 equivalent in the sense that functions with those parameter types
1240 can have equivalent types. The two lists must be equivalent,
1241 element by element. */
1244 compparms (const_tree parms1, const_tree parms2)
1248 /* An unspecified parmlist matches any specified parmlist
1249 whose argument types don't need default promotions. */
1251 for (t1 = parms1, t2 = parms2;
1253 t1 = TREE_CHAIN (t1), t2 = TREE_CHAIN (t2))
1255 /* If one parmlist is shorter than the other,
1256 they fail to match. */
1259 if (!same_type_p (TREE_VALUE (t1), TREE_VALUE (t2)))
1266 /* Process a sizeof or alignof expression where the operand is a
1270 cxx_sizeof_or_alignof_type (tree type, enum tree_code op, bool complain)
1275 gcc_assert (op == SIZEOF_EXPR || op == ALIGNOF_EXPR);
1276 if (type == error_mark_node)
1277 return error_mark_node;
1279 type = non_reference (type);
1280 if (TREE_CODE (type) == METHOD_TYPE)
1283 pedwarn (input_location, pedantic ? OPT_pedantic : OPT_Wpointer_arith,
1284 "invalid application of %qs to a member function",
1285 operator_name_info[(int) op].name);
1286 value = size_one_node;
1289 dependent_p = dependent_type_p (type);
1291 complete_type (type);
1293 /* VLA types will have a non-constant size. In the body of an
1294 uninstantiated template, we don't need to try to compute the
1295 value, because the sizeof expression is not an integral
1296 constant expression in that case. And, if we do try to
1297 compute the value, we'll likely end up with SAVE_EXPRs, which
1298 the template substitution machinery does not expect to see. */
1299 || (processing_template_decl
1300 && COMPLETE_TYPE_P (type)
1301 && TREE_CODE (TYPE_SIZE (type)) != INTEGER_CST))
1303 value = build_min (op, size_type_node, type);
1304 TREE_READONLY (value) = 1;
1308 return c_sizeof_or_alignof_type (complete_type (type),
1313 /* Return the size of the type, without producing any warnings for
1314 types whose size cannot be taken. This routine should be used only
1315 in some other routine that has already produced a diagnostic about
1316 using the size of such a type. */
1318 cxx_sizeof_nowarn (tree type)
1320 if (TREE_CODE (type) == FUNCTION_TYPE
1321 || TREE_CODE (type) == VOID_TYPE
1322 || TREE_CODE (type) == ERROR_MARK)
1323 return size_one_node;
1324 else if (!COMPLETE_TYPE_P (type))
1325 return size_zero_node;
1327 return cxx_sizeof_or_alignof_type (type, SIZEOF_EXPR, false);
1330 /* Process a sizeof expression where the operand is an expression. */
1333 cxx_sizeof_expr (tree e, tsubst_flags_t complain)
1335 if (e == error_mark_node)
1336 return error_mark_node;
1338 if (processing_template_decl)
1340 e = build_min (SIZEOF_EXPR, size_type_node, e);
1341 TREE_SIDE_EFFECTS (e) = 0;
1342 TREE_READONLY (e) = 1;
1347 if (TREE_CODE (e) == COMPONENT_REF
1348 && TREE_CODE (TREE_OPERAND (e, 1)) == FIELD_DECL
1349 && DECL_C_BIT_FIELD (TREE_OPERAND (e, 1)))
1351 if (complain & tf_error)
1352 error ("invalid application of %<sizeof%> to a bit-field");
1354 return error_mark_node;
1357 else if (is_overloaded_fn (e))
1359 if (complain & tf_error)
1360 permerror (input_location, "ISO C++ forbids applying %<sizeof%> to an expression of "
1363 return error_mark_node;
1366 else if (type_unknown_p (e))
1368 if (complain & tf_error)
1369 cxx_incomplete_type_error (e, TREE_TYPE (e));
1371 return error_mark_node;
1377 return cxx_sizeof_or_alignof_type (e, SIZEOF_EXPR, complain & tf_error);
1380 /* Implement the __alignof keyword: Return the minimum required
1381 alignment of E, measured in bytes. For VAR_DECL's and
1382 FIELD_DECL's return DECL_ALIGN (which can be set from an
1383 "aligned" __attribute__ specification). */
1386 cxx_alignof_expr (tree e, tsubst_flags_t complain)
1390 if (e == error_mark_node)
1391 return error_mark_node;
1393 if (processing_template_decl)
1395 e = build_min (ALIGNOF_EXPR, size_type_node, e);
1396 TREE_SIDE_EFFECTS (e) = 0;
1397 TREE_READONLY (e) = 1;
1402 if (TREE_CODE (e) == VAR_DECL)
1403 t = size_int (DECL_ALIGN_UNIT (e));
1404 else if (TREE_CODE (e) == COMPONENT_REF
1405 && TREE_CODE (TREE_OPERAND (e, 1)) == FIELD_DECL
1406 && DECL_C_BIT_FIELD (TREE_OPERAND (e, 1)))
1408 if (complain & tf_error)
1409 error ("invalid application of %<__alignof%> to a bit-field");
1411 return error_mark_node;
1414 else if (TREE_CODE (e) == COMPONENT_REF
1415 && TREE_CODE (TREE_OPERAND (e, 1)) == FIELD_DECL)
1416 t = size_int (DECL_ALIGN_UNIT (TREE_OPERAND (e, 1)));
1417 else if (is_overloaded_fn (e))
1419 if (complain & tf_error)
1420 permerror (input_location, "ISO C++ forbids applying %<__alignof%> to an expression of "
1423 return error_mark_node;
1424 if (TREE_CODE (e) == FUNCTION_DECL)
1425 t = size_int (DECL_ALIGN_UNIT (e));
1429 else if (type_unknown_p (e))
1431 if (complain & tf_error)
1432 cxx_incomplete_type_error (e, TREE_TYPE (e));
1434 return error_mark_node;
1438 return cxx_sizeof_or_alignof_type (TREE_TYPE (e), ALIGNOF_EXPR,
1439 complain & tf_error);
1441 return fold_convert (size_type_node, t);
1444 /* Process a sizeof or alignof expression E with code OP where the operand
1445 is an expression. */
1448 cxx_sizeof_or_alignof_expr (tree e, enum tree_code op, bool complain)
1450 if (op == SIZEOF_EXPR)
1451 return cxx_sizeof_expr (e, complain? tf_warning_or_error : tf_none);
1453 return cxx_alignof_expr (e, complain? tf_warning_or_error : tf_none);
1456 /* EXPR is being used in a context that is not a function call.
1461 The expression can be used only as the left-hand operand of a
1462 member function call.
1464 [expr.mptr.operator]
1466 If the result of .* or ->* is a function, then that result can be
1467 used only as the operand for the function call operator ().
1469 by issuing an error message if appropriate. Returns true iff EXPR
1470 violates these rules. */
1473 invalid_nonstatic_memfn_p (const_tree expr, tsubst_flags_t complain)
1475 if (TREE_CODE (TREE_TYPE (expr)) == METHOD_TYPE)
1477 if (complain & tf_error)
1478 error ("invalid use of non-static member function");
1484 /* If EXP is a reference to a bitfield, and the type of EXP does not
1485 match the declared type of the bitfield, return the declared type
1486 of the bitfield. Otherwise, return NULL_TREE. */
1489 is_bitfield_expr_with_lowered_type (const_tree exp)
1491 switch (TREE_CODE (exp))
1494 if (!is_bitfield_expr_with_lowered_type (TREE_OPERAND (exp, 1)
1495 ? TREE_OPERAND (exp, 1)
1496 : TREE_OPERAND (exp, 0)))
1498 return is_bitfield_expr_with_lowered_type (TREE_OPERAND (exp, 2));
1501 return is_bitfield_expr_with_lowered_type (TREE_OPERAND (exp, 1));
1505 return is_bitfield_expr_with_lowered_type (TREE_OPERAND (exp, 0));
1511 field = TREE_OPERAND (exp, 1);
1512 if (TREE_CODE (field) != FIELD_DECL || !DECL_BIT_FIELD_TYPE (field))
1514 if (same_type_ignoring_top_level_qualifiers_p
1515 (TREE_TYPE (exp), DECL_BIT_FIELD_TYPE (field)))
1517 return DECL_BIT_FIELD_TYPE (field);
1521 if (TYPE_MAIN_VARIANT (TREE_TYPE (TREE_OPERAND (exp, 0)))
1522 == TYPE_MAIN_VARIANT (TREE_TYPE (exp)))
1523 return is_bitfield_expr_with_lowered_type (TREE_OPERAND (exp, 0));
1531 /* Like is_bitfield_with_lowered_type, except that if EXP is not a
1532 bitfield with a lowered type, the type of EXP is returned, rather
1536 unlowered_expr_type (const_tree exp)
1540 type = is_bitfield_expr_with_lowered_type (exp);
1542 type = TREE_TYPE (exp);
1547 /* Perform the conversions in [expr] that apply when an lvalue appears
1548 in an rvalue context: the lvalue-to-rvalue, array-to-pointer, and
1549 function-to-pointer conversions. In addition, manifest constants
1550 are replaced by their values, and bitfield references are converted
1551 to their declared types.
1553 Although the returned value is being used as an rvalue, this
1554 function does not wrap the returned expression in a
1555 NON_LVALUE_EXPR; the caller is expected to be mindful of the fact
1556 that the return value is no longer an lvalue. */
1559 decay_conversion (tree exp)
1562 enum tree_code code;
1564 type = TREE_TYPE (exp);
1565 if (type == error_mark_node)
1566 return error_mark_node;
1568 if (type_unknown_p (exp))
1570 cxx_incomplete_type_error (exp, TREE_TYPE (exp));
1571 return error_mark_node;
1574 exp = decl_constant_value (exp);
1575 if (error_operand_p (exp))
1576 return error_mark_node;
1578 /* build_c_cast puts on a NOP_EXPR to make the result not an lvalue.
1579 Leave such NOP_EXPRs, since RHS is being used in non-lvalue context. */
1580 code = TREE_CODE (type);
1581 if (code == VOID_TYPE)
1583 error ("void value not ignored as it ought to be");
1584 return error_mark_node;
1586 if (invalid_nonstatic_memfn_p (exp, tf_warning_or_error))
1587 return error_mark_node;
1588 if (code == FUNCTION_TYPE || is_overloaded_fn (exp))
1589 return cp_build_unary_op (ADDR_EXPR, exp, 0, tf_warning_or_error);
1590 if (code == ARRAY_TYPE)
1595 if (TREE_CODE (exp) == INDIRECT_REF)
1596 return build_nop (build_pointer_type (TREE_TYPE (type)),
1597 TREE_OPERAND (exp, 0));
1599 if (TREE_CODE (exp) == COMPOUND_EXPR)
1601 tree op1 = decay_conversion (TREE_OPERAND (exp, 1));
1602 return build2 (COMPOUND_EXPR, TREE_TYPE (op1),
1603 TREE_OPERAND (exp, 0), op1);
1607 && ! (TREE_CODE (exp) == CONSTRUCTOR && TREE_STATIC (exp)))
1609 error ("invalid use of non-lvalue array");
1610 return error_mark_node;
1613 ptrtype = build_pointer_type (TREE_TYPE (type));
1615 if (TREE_CODE (exp) == VAR_DECL)
1617 if (!cxx_mark_addressable (exp))
1618 return error_mark_node;
1619 adr = build_nop (ptrtype, build_address (exp));
1622 /* This way is better for a COMPONENT_REF since it can
1623 simplify the offset for a component. */
1624 adr = cp_build_unary_op (ADDR_EXPR, exp, 1, tf_warning_or_error);
1625 return cp_convert (ptrtype, adr);
1628 /* If a bitfield is used in a context where integral promotion
1629 applies, then the caller is expected to have used
1630 default_conversion. That function promotes bitfields correctly
1631 before calling this function. At this point, if we have a
1632 bitfield referenced, we may assume that is not subject to
1633 promotion, and that, therefore, the type of the resulting rvalue
1634 is the declared type of the bitfield. */
1635 exp = convert_bitfield_to_declared_type (exp);
1637 /* We do not call rvalue() here because we do not want to wrap EXP
1638 in a NON_LVALUE_EXPR. */
1642 Non-class rvalues always have cv-unqualified types. */
1643 type = TREE_TYPE (exp);
1644 if (!CLASS_TYPE_P (type) && cp_type_quals (type))
1645 exp = build_nop (TYPE_MAIN_VARIANT (type), exp);
1650 /* Perform preparatory conversions, as part of the "usual arithmetic
1651 conversions". In particular, as per [expr]:
1653 Whenever an lvalue expression appears as an operand of an
1654 operator that expects the rvalue for that operand, the
1655 lvalue-to-rvalue, array-to-pointer, or function-to-pointer
1656 standard conversions are applied to convert the expression to an
1659 In addition, we perform integral promotions here, as those are
1660 applied to both operands to a binary operator before determining
1661 what additional conversions should apply. */
1664 default_conversion (tree exp)
1666 /* Perform the integral promotions first so that bitfield
1667 expressions (which may promote to "int", even if the bitfield is
1668 declared "unsigned") are promoted correctly. */
1669 if (INTEGRAL_OR_UNSCOPED_ENUMERATION_TYPE_P (TREE_TYPE (exp)))
1670 exp = perform_integral_promotions (exp);
1671 /* Perform the other conversions. */
1672 exp = decay_conversion (exp);
1677 /* EXPR is an expression with an integral or enumeration type.
1678 Perform the integral promotions in [conv.prom], and return the
1682 perform_integral_promotions (tree expr)
1689 If the bitfield has an enumerated type, it is treated as any
1690 other value of that type for promotion purposes. */
1691 type = is_bitfield_expr_with_lowered_type (expr);
1692 if (!type || TREE_CODE (type) != ENUMERAL_TYPE)
1693 type = TREE_TYPE (expr);
1694 gcc_assert (INTEGRAL_OR_ENUMERATION_TYPE_P (type));
1695 promoted_type = type_promotes_to (type);
1696 if (type != promoted_type)
1697 expr = cp_convert (promoted_type, expr);
1701 /* Returns nonzero iff exp is a STRING_CST or the result of applying
1702 decay_conversion to one. */
1705 string_conv_p (const_tree totype, const_tree exp, int warn)
1709 if (TREE_CODE (totype) != POINTER_TYPE)
1712 t = TREE_TYPE (totype);
1713 if (!same_type_p (t, char_type_node)
1714 && !same_type_p (t, char16_type_node)
1715 && !same_type_p (t, char32_type_node)
1716 && !same_type_p (t, wchar_type_node))
1719 if (TREE_CODE (exp) == STRING_CST)
1721 /* Make sure that we don't try to convert between char and wide chars. */
1722 if (!same_type_p (TYPE_MAIN_VARIANT (TREE_TYPE (TREE_TYPE (exp))), t))
1727 /* Is this a string constant which has decayed to 'const char *'? */
1728 t = build_pointer_type (build_qualified_type (t, TYPE_QUAL_CONST));
1729 if (!same_type_p (TREE_TYPE (exp), t))
1732 if (TREE_CODE (exp) != ADDR_EXPR
1733 || TREE_CODE (TREE_OPERAND (exp, 0)) != STRING_CST)
1737 /* This warning is not very useful, as it complains about printf. */
1739 warning (OPT_Wwrite_strings,
1740 "deprecated conversion from string constant to %qT",
1746 /* Given a COND_EXPR, MIN_EXPR, or MAX_EXPR in T, return it in a form that we
1747 can, for example, use as an lvalue. This code used to be in
1748 unary_complex_lvalue, but we needed it to deal with `a = (d == c) ? b : c'
1749 expressions, where we're dealing with aggregates. But now it's again only
1750 called from unary_complex_lvalue. The case (in particular) that led to
1751 this was with CODE == ADDR_EXPR, since it's not an lvalue when we'd
1755 rationalize_conditional_expr (enum tree_code code, tree t,
1756 tsubst_flags_t complain)
1758 /* For MIN_EXPR or MAX_EXPR, fold-const.c has arranged things so that
1759 the first operand is always the one to be used if both operands
1760 are equal, so we know what conditional expression this used to be. */
1761 if (TREE_CODE (t) == MIN_EXPR || TREE_CODE (t) == MAX_EXPR)
1763 tree op0 = TREE_OPERAND (t, 0);
1764 tree op1 = TREE_OPERAND (t, 1);
1766 /* The following code is incorrect if either operand side-effects. */
1767 gcc_assert (!TREE_SIDE_EFFECTS (op0)
1768 && !TREE_SIDE_EFFECTS (op1));
1770 build_conditional_expr (build_x_binary_op ((TREE_CODE (t) == MIN_EXPR
1771 ? LE_EXPR : GE_EXPR),
1772 op0, TREE_CODE (op0),
1773 op1, TREE_CODE (op1),
1774 /*overloaded_p=*/NULL,
1776 cp_build_unary_op (code, op0, 0, complain),
1777 cp_build_unary_op (code, op1, 0, complain),
1782 build_conditional_expr (TREE_OPERAND (t, 0),
1783 cp_build_unary_op (code, TREE_OPERAND (t, 1), 0,
1785 cp_build_unary_op (code, TREE_OPERAND (t, 2), 0,
1790 /* Given the TYPE of an anonymous union field inside T, return the
1791 FIELD_DECL for the field. If not found return NULL_TREE. Because
1792 anonymous unions can nest, we must also search all anonymous unions
1793 that are directly reachable. */
1796 lookup_anon_field (tree t, tree type)
1800 for (field = TYPE_FIELDS (t); field; field = TREE_CHAIN (field))
1802 if (TREE_STATIC (field))
1804 if (TREE_CODE (field) != FIELD_DECL || DECL_ARTIFICIAL (field))
1807 /* If we find it directly, return the field. */
1808 if (DECL_NAME (field) == NULL_TREE
1809 && type == TYPE_MAIN_VARIANT (TREE_TYPE (field)))
1814 /* Otherwise, it could be nested, search harder. */
1815 if (DECL_NAME (field) == NULL_TREE
1816 && ANON_AGGR_TYPE_P (TREE_TYPE (field)))
1818 tree subfield = lookup_anon_field (TREE_TYPE (field), type);
1826 /* Build an expression representing OBJECT.MEMBER. OBJECT is an
1827 expression; MEMBER is a DECL or baselink. If ACCESS_PATH is
1828 non-NULL, it indicates the path to the base used to name MEMBER.
1829 If PRESERVE_REFERENCE is true, the expression returned will have
1830 REFERENCE_TYPE if the MEMBER does. Otherwise, the expression
1831 returned will have the type referred to by the reference.
1833 This function does not perform access control; that is either done
1834 earlier by the parser when the name of MEMBER is resolved to MEMBER
1835 itself, or later when overload resolution selects one of the
1836 functions indicated by MEMBER. */
1839 build_class_member_access_expr (tree object, tree member,
1840 tree access_path, bool preserve_reference,
1841 tsubst_flags_t complain)
1845 tree result = NULL_TREE;
1847 if (error_operand_p (object) || error_operand_p (member))
1848 return error_mark_node;
1850 gcc_assert (DECL_P (member) || BASELINK_P (member));
1854 The type of the first expression shall be "class object" (of a
1856 object_type = TREE_TYPE (object);
1857 if (!currently_open_class (object_type)
1858 && !complete_type_or_else (object_type, object))
1859 return error_mark_node;
1860 if (!CLASS_TYPE_P (object_type))
1862 if (complain & tf_error)
1863 error ("request for member %qD in %qE, which is of non-class type %qT",
1864 member, object, object_type);
1865 return error_mark_node;
1868 /* The standard does not seem to actually say that MEMBER must be a
1869 member of OBJECT_TYPE. However, that is clearly what is
1871 if (DECL_P (member))
1873 member_scope = DECL_CLASS_CONTEXT (member);
1875 if (TREE_DEPRECATED (member))
1876 warn_deprecated_use (member);
1879 member_scope = BINFO_TYPE (BASELINK_ACCESS_BINFO (member));
1880 /* If MEMBER is from an anonymous aggregate, MEMBER_SCOPE will
1881 presently be the anonymous union. Go outwards until we find a
1882 type related to OBJECT_TYPE. */
1883 while (ANON_AGGR_TYPE_P (member_scope)
1884 && !same_type_ignoring_top_level_qualifiers_p (member_scope,
1886 member_scope = TYPE_CONTEXT (member_scope);
1887 if (!member_scope || !DERIVED_FROM_P (member_scope, object_type))
1889 if (complain & tf_error)
1891 if (TREE_CODE (member) == FIELD_DECL)
1892 error ("invalid use of nonstatic data member %qE", member);
1894 error ("%qD is not a member of %qT", member, object_type);
1896 return error_mark_node;
1899 /* Transform `(a, b).x' into `(*(a, &b)).x', `(a ? b : c).x' into
1900 `(*(a ? &b : &c)).x', and so on. A COND_EXPR is only an lvalue
1901 in the front end; only _DECLs and _REFs are lvalues in the back end. */
1903 tree temp = unary_complex_lvalue (ADDR_EXPR, object);
1905 object = cp_build_indirect_ref (temp, NULL, complain);
1908 /* In [expr.ref], there is an explicit list of the valid choices for
1909 MEMBER. We check for each of those cases here. */
1910 if (TREE_CODE (member) == VAR_DECL)
1912 /* A static data member. */
1914 /* If OBJECT has side-effects, they are supposed to occur. */
1915 if (TREE_SIDE_EFFECTS (object))
1916 result = build2 (COMPOUND_EXPR, TREE_TYPE (result), object, result);
1918 else if (TREE_CODE (member) == FIELD_DECL)
1920 /* A non-static data member. */
1925 null_object_p = (TREE_CODE (object) == INDIRECT_REF
1926 && integer_zerop (TREE_OPERAND (object, 0)));
1928 /* Convert OBJECT to the type of MEMBER. */
1929 if (!same_type_p (TYPE_MAIN_VARIANT (object_type),
1930 TYPE_MAIN_VARIANT (member_scope)))
1935 binfo = lookup_base (access_path ? access_path : object_type,
1936 member_scope, ba_unique, &kind);
1937 if (binfo == error_mark_node)
1938 return error_mark_node;
1940 /* It is invalid to try to get to a virtual base of a
1941 NULL object. The most common cause is invalid use of
1943 if (null_object_p && kind == bk_via_virtual)
1945 if (complain & tf_error)
1947 error ("invalid access to non-static data member %qD of "
1950 error ("(perhaps the %<offsetof%> macro was used incorrectly)");
1952 return error_mark_node;
1955 /* Convert to the base. */
1956 object = build_base_path (PLUS_EXPR, object, binfo,
1958 /* If we found the base successfully then we should be able
1959 to convert to it successfully. */
1960 gcc_assert (object != error_mark_node);
1963 /* Complain about other invalid uses of offsetof, even though they will
1964 give the right answer. Note that we complain whether or not they
1965 actually used the offsetof macro, since there's no way to know at this
1966 point. So we just give a warning, instead of a pedwarn. */
1967 /* Do not produce this warning for base class field references, because
1968 we know for a fact that didn't come from offsetof. This does occur
1969 in various testsuite cases where a null object is passed where a
1970 vtable access is required. */
1971 if (null_object_p && warn_invalid_offsetof
1972 && CLASSTYPE_NON_POD_P (object_type)
1973 && !DECL_FIELD_IS_BASE (member)
1975 && (complain & tf_warning))
1977 warning (OPT_Winvalid_offsetof,
1978 "invalid access to non-static data member %qD "
1979 " of NULL object", member);
1980 warning (OPT_Winvalid_offsetof,
1981 "(perhaps the %<offsetof%> macro was used incorrectly)");
1984 /* If MEMBER is from an anonymous aggregate, we have converted
1985 OBJECT so that it refers to the class containing the
1986 anonymous union. Generate a reference to the anonymous union
1987 itself, and recur to find MEMBER. */
1988 if (ANON_AGGR_TYPE_P (DECL_CONTEXT (member))
1989 /* When this code is called from build_field_call, the
1990 object already has the type of the anonymous union.
1991 That is because the COMPONENT_REF was already
1992 constructed, and was then disassembled before calling
1993 build_field_call. After the function-call code is
1994 cleaned up, this waste can be eliminated. */
1995 && (!same_type_ignoring_top_level_qualifiers_p
1996 (TREE_TYPE (object), DECL_CONTEXT (member))))
1998 tree anonymous_union;
2000 anonymous_union = lookup_anon_field (TREE_TYPE (object),
2001 DECL_CONTEXT (member));
2002 object = build_class_member_access_expr (object,
2004 /*access_path=*/NULL_TREE,
2009 /* Compute the type of the field, as described in [expr.ref]. */
2010 type_quals = TYPE_UNQUALIFIED;
2011 member_type = TREE_TYPE (member);
2012 if (TREE_CODE (member_type) != REFERENCE_TYPE)
2014 type_quals = (cp_type_quals (member_type)
2015 | cp_type_quals (object_type));
2017 /* A field is const (volatile) if the enclosing object, or the
2018 field itself, is const (volatile). But, a mutable field is
2019 not const, even within a const object. */
2020 if (DECL_MUTABLE_P (member))
2021 type_quals &= ~TYPE_QUAL_CONST;
2022 member_type = cp_build_qualified_type (member_type, type_quals);
2025 result = build3 (COMPONENT_REF, member_type, object, member,
2027 result = fold_if_not_in_template (result);
2029 /* Mark the expression const or volatile, as appropriate. Even
2030 though we've dealt with the type above, we still have to mark the
2031 expression itself. */
2032 if (type_quals & TYPE_QUAL_CONST)
2033 TREE_READONLY (result) = 1;
2034 if (type_quals & TYPE_QUAL_VOLATILE)
2035 TREE_THIS_VOLATILE (result) = 1;
2037 else if (BASELINK_P (member))
2039 /* The member is a (possibly overloaded) member function. */
2043 /* If the MEMBER is exactly one static member function, then we
2044 know the type of the expression. Otherwise, we must wait
2045 until overload resolution has been performed. */
2046 functions = BASELINK_FUNCTIONS (member);
2047 if (TREE_CODE (functions) == FUNCTION_DECL
2048 && DECL_STATIC_FUNCTION_P (functions))
2049 type = TREE_TYPE (functions);
2051 type = unknown_type_node;
2052 /* Note that we do not convert OBJECT to the BASELINK_BINFO
2053 base. That will happen when the function is called. */
2054 result = build3 (COMPONENT_REF, type, object, member, NULL_TREE);
2056 else if (TREE_CODE (member) == CONST_DECL)
2058 /* The member is an enumerator. */
2060 /* If OBJECT has side-effects, they are supposed to occur. */
2061 if (TREE_SIDE_EFFECTS (object))
2062 result = build2 (COMPOUND_EXPR, TREE_TYPE (result),
2067 if (complain & tf_error)
2068 error ("invalid use of %qD", member);
2069 return error_mark_node;
2072 if (!preserve_reference)
2075 If E2 is declared to have type "reference to T", then ... the
2076 type of E1.E2 is T. */
2077 result = convert_from_reference (result);
2082 /* Return the destructor denoted by OBJECT.SCOPE::~DTOR_NAME, or, if
2083 SCOPE is NULL, by OBJECT.~DTOR_NAME. */
2086 lookup_destructor (tree object, tree scope, tree dtor_name)
2088 tree object_type = TREE_TYPE (object);
2089 tree dtor_type = TREE_OPERAND (dtor_name, 0);
2092 if (scope && !check_dtor_name (scope, dtor_type))
2094 error ("qualified type %qT does not match destructor name ~%qT",
2096 return error_mark_node;
2098 if (!DERIVED_FROM_P (dtor_type, TYPE_MAIN_VARIANT (object_type)))
2100 error ("the type being destroyed is %qT, but the destructor refers to %qT",
2101 TYPE_MAIN_VARIANT (object_type), dtor_type);
2102 return error_mark_node;
2104 expr = lookup_member (dtor_type, complete_dtor_identifier,
2105 /*protect=*/1, /*want_type=*/false);
2106 expr = (adjust_result_of_qualified_name_lookup
2107 (expr, dtor_type, object_type));
2111 /* An expression of the form "A::template B" has been resolved to
2112 DECL. Issue a diagnostic if B is not a template or template
2116 check_template_keyword (tree decl)
2118 /* The standard says:
2122 If a name prefixed by the keyword template is not a member
2123 template, the program is ill-formed.
2125 DR 228 removed the restriction that the template be a member
2128 DR 96, if accepted would add the further restriction that explicit
2129 template arguments must be provided if the template keyword is
2130 used, but, as of 2005-10-16, that DR is still in "drafting". If
2131 this DR is accepted, then the semantic checks here can be
2132 simplified, as the entity named must in fact be a template
2133 specialization, rather than, as at present, a set of overloaded
2134 functions containing at least one template function. */
2135 if (TREE_CODE (decl) != TEMPLATE_DECL
2136 && TREE_CODE (decl) != TEMPLATE_ID_EXPR)
2138 if (!is_overloaded_fn (decl))
2139 permerror (input_location, "%qD is not a template", decl);
2144 if (BASELINK_P (fns))
2145 fns = BASELINK_FUNCTIONS (fns);
2148 tree fn = OVL_CURRENT (fns);
2149 if (TREE_CODE (fn) == TEMPLATE_DECL
2150 || TREE_CODE (fn) == TEMPLATE_ID_EXPR)
2152 if (TREE_CODE (fn) == FUNCTION_DECL
2153 && DECL_USE_TEMPLATE (fn)
2154 && PRIMARY_TEMPLATE_P (DECL_TI_TEMPLATE (fn)))
2156 fns = OVL_NEXT (fns);
2159 permerror (input_location, "%qD is not a template", decl);
2164 /* This function is called by the parser to process a class member
2165 access expression of the form OBJECT.NAME. NAME is a node used by
2166 the parser to represent a name; it is not yet a DECL. It may,
2167 however, be a BASELINK where the BASELINK_FUNCTIONS is a
2168 TEMPLATE_ID_EXPR. Templates must be looked up by the parser, and
2169 there is no reason to do the lookup twice, so the parser keeps the
2170 BASELINK. TEMPLATE_P is true iff NAME was explicitly declared to
2171 be a template via the use of the "A::template B" syntax. */
2174 finish_class_member_access_expr (tree object, tree name, bool template_p,
2175 tsubst_flags_t complain)
2180 tree access_path = NULL_TREE;
2181 tree orig_object = object;
2182 tree orig_name = name;
2184 if (object == error_mark_node || name == error_mark_node)
2185 return error_mark_node;
2187 /* If OBJECT is an ObjC class instance, we must obey ObjC access rules. */
2188 if (!objc_is_public (object, name))
2189 return error_mark_node;
2191 object_type = TREE_TYPE (object);
2193 if (processing_template_decl)
2195 if (/* If OBJECT_TYPE is dependent, so is OBJECT.NAME. */
2196 dependent_type_p (object_type)
2197 /* If NAME is just an IDENTIFIER_NODE, then the expression
2199 || TREE_CODE (object) == IDENTIFIER_NODE
2200 /* If NAME is "f<args>", where either 'f' or 'args' is
2201 dependent, then the expression is dependent. */
2202 || (TREE_CODE (name) == TEMPLATE_ID_EXPR
2203 && dependent_template_id_p (TREE_OPERAND (name, 0),
2204 TREE_OPERAND (name, 1)))
2205 /* If NAME is "T::X" where "T" is dependent, then the
2206 expression is dependent. */
2207 || (TREE_CODE (name) == SCOPE_REF
2208 && TYPE_P (TREE_OPERAND (name, 0))
2209 && dependent_type_p (TREE_OPERAND (name, 0))))
2210 return build_min_nt (COMPONENT_REF, object, name, NULL_TREE);
2211 object = build_non_dependent_expr (object);
2216 The type of the first expression shall be "class object" (of a
2218 if (!currently_open_class (object_type)
2219 && !complete_type_or_else (object_type, object))
2220 return error_mark_node;
2221 if (!CLASS_TYPE_P (object_type))
2223 if (complain & tf_error)
2224 error ("request for member %qD in %qE, which is of non-class type %qT",
2225 name, object, object_type);
2226 return error_mark_node;
2229 if (BASELINK_P (name))
2230 /* A member function that has already been looked up. */
2234 bool is_template_id = false;
2235 tree template_args = NULL_TREE;
2238 if (TREE_CODE (name) == TEMPLATE_ID_EXPR)
2240 is_template_id = true;
2241 template_args = TREE_OPERAND (name, 1);
2242 name = TREE_OPERAND (name, 0);
2244 if (TREE_CODE (name) == OVERLOAD)
2245 name = DECL_NAME (get_first_fn (name));
2246 else if (DECL_P (name))
2247 name = DECL_NAME (name);
2250 if (TREE_CODE (name) == SCOPE_REF)
2252 /* A qualified name. The qualifying class or namespace `S'
2253 has already been looked up; it is either a TYPE or a
2255 scope = TREE_OPERAND (name, 0);
2256 name = TREE_OPERAND (name, 1);
2258 /* If SCOPE is a namespace, then the qualified name does not
2259 name a member of OBJECT_TYPE. */
2260 if (TREE_CODE (scope) == NAMESPACE_DECL)
2262 if (complain & tf_error)
2263 error ("%<%D::%D%> is not a member of %qT",
2264 scope, name, object_type);
2265 return error_mark_node;
2268 gcc_assert (CLASS_TYPE_P (scope));
2269 gcc_assert (TREE_CODE (name) == IDENTIFIER_NODE
2270 || TREE_CODE (name) == BIT_NOT_EXPR);
2272 /* Find the base of OBJECT_TYPE corresponding to SCOPE. */
2273 access_path = lookup_base (object_type, scope, ba_check, NULL);
2274 if (access_path == error_mark_node)
2275 return error_mark_node;
2278 if (complain & tf_error)
2279 error ("%qT is not a base of %qT", scope, object_type);
2280 return error_mark_node;
2286 access_path = object_type;
2289 if (TREE_CODE (name) == BIT_NOT_EXPR)
2290 member = lookup_destructor (object, scope, name);
2293 /* Look up the member. */
2294 member = lookup_member (access_path, name, /*protect=*/1,
2295 /*want_type=*/false);
2296 if (member == NULL_TREE)
2298 if (complain & tf_error)
2299 error ("%qD has no member named %qE", object_type, name);
2300 return error_mark_node;
2302 if (member == error_mark_node)
2303 return error_mark_node;
2308 tree templ = member;
2310 if (BASELINK_P (templ))
2311 templ = lookup_template_function (templ, template_args);
2314 if (complain & tf_error)
2315 error ("%qD is not a member template function", name);
2316 return error_mark_node;
2321 if (TREE_DEPRECATED (member))
2322 warn_deprecated_use (member);
2325 check_template_keyword (member);
2327 expr = build_class_member_access_expr (object, member, access_path,
2328 /*preserve_reference=*/false,
2330 if (processing_template_decl && expr != error_mark_node)
2332 if (BASELINK_P (member))
2334 if (TREE_CODE (orig_name) == SCOPE_REF)
2335 BASELINK_QUALIFIED_P (member) = 1;
2338 return build_min_non_dep (COMPONENT_REF, expr,
2339 orig_object, orig_name,
2346 /* Return an expression for the MEMBER_NAME field in the internal
2347 representation of PTRMEM, a pointer-to-member function. (Each
2348 pointer-to-member function type gets its own RECORD_TYPE so it is
2349 more convenient to access the fields by name than by FIELD_DECL.)
2350 This routine converts the NAME to a FIELD_DECL and then creates the
2351 node for the complete expression. */
2354 build_ptrmemfunc_access_expr (tree ptrmem, tree member_name)
2360 /* This code is a stripped down version of
2361 build_class_member_access_expr. It does not work to use that
2362 routine directly because it expects the object to be of class
2364 ptrmem_type = TREE_TYPE (ptrmem);
2365 gcc_assert (TYPE_PTRMEMFUNC_P (ptrmem_type));
2366 member = lookup_member (ptrmem_type, member_name, /*protect=*/0,
2367 /*want_type=*/false);
2368 member_type = cp_build_qualified_type (TREE_TYPE (member),
2369 cp_type_quals (ptrmem_type));
2370 return fold_build3 (COMPONENT_REF, member_type,
2371 ptrmem, member, NULL_TREE);
2374 /* Given an expression PTR for a pointer, return an expression
2375 for the value pointed to.
2376 ERRORSTRING is the name of the operator to appear in error messages.
2378 This function may need to overload OPERATOR_FNNAME.
2379 Must also handle REFERENCE_TYPEs for C++. */
2382 build_x_indirect_ref (tree expr, const char *errorstring,
2383 tsubst_flags_t complain)
2385 tree orig_expr = expr;
2388 if (processing_template_decl)
2390 if (type_dependent_expression_p (expr))
2391 return build_min_nt (INDIRECT_REF, expr);
2392 expr = build_non_dependent_expr (expr);
2395 rval = build_new_op (INDIRECT_REF, LOOKUP_NORMAL, expr, NULL_TREE,
2396 NULL_TREE, /*overloaded_p=*/NULL, complain);
2398 rval = cp_build_indirect_ref (expr, errorstring, complain);
2400 if (processing_template_decl && rval != error_mark_node)
2401 return build_min_non_dep (INDIRECT_REF, rval, orig_expr);
2406 /* Helper function called from c-common. */
2408 build_indirect_ref (tree ptr, const char *errorstring,
2409 location_t loc __attribute__ ((__unused__)))
2411 return cp_build_indirect_ref (ptr, errorstring, tf_warning_or_error);
2415 cp_build_indirect_ref (tree ptr, const char *errorstring,
2416 tsubst_flags_t complain)
2420 if (ptr == error_mark_node)
2421 return error_mark_node;
2423 if (ptr == current_class_ptr)
2424 return current_class_ref;
2426 pointer = (TREE_CODE (TREE_TYPE (ptr)) == REFERENCE_TYPE
2427 ? ptr : decay_conversion (ptr));
2428 type = TREE_TYPE (pointer);
2430 if (POINTER_TYPE_P (type))
2434 If the type of the expression is "pointer to T," the type
2435 of the result is "T."
2437 We must use the canonical variant because certain parts of
2438 the back end, like fold, do pointer comparisons between
2440 tree t = canonical_type_variant (TREE_TYPE (type));
2442 if (CONVERT_EXPR_P (ptr)
2443 || TREE_CODE (ptr) == VIEW_CONVERT_EXPR)
2445 /* If a warning is issued, mark it to avoid duplicates from
2446 the backend. This only needs to be done at
2447 warn_strict_aliasing > 2. */
2448 if (warn_strict_aliasing > 2)
2449 if (strict_aliasing_warning (TREE_TYPE (TREE_OPERAND (ptr, 0)),
2450 type, TREE_OPERAND (ptr, 0)))
2451 TREE_NO_WARNING (ptr) = 1;
2454 if (VOID_TYPE_P (t))
2456 /* A pointer to incomplete type (other than cv void) can be
2457 dereferenced [expr.unary.op]/1 */
2458 if (complain & tf_error)
2459 error ("%qT is not a pointer-to-object type", type);
2460 return error_mark_node;
2462 else if (TREE_CODE (pointer) == ADDR_EXPR
2463 && same_type_p (t, TREE_TYPE (TREE_OPERAND (pointer, 0))))
2464 /* The POINTER was something like `&x'. We simplify `*&x' to
2466 return TREE_OPERAND (pointer, 0);
2469 tree ref = build1 (INDIRECT_REF, t, pointer);
2471 /* We *must* set TREE_READONLY when dereferencing a pointer to const,
2472 so that we get the proper error message if the result is used
2473 to assign to. Also, &* is supposed to be a no-op. */
2474 TREE_READONLY (ref) = CP_TYPE_CONST_P (t);
2475 TREE_THIS_VOLATILE (ref) = CP_TYPE_VOLATILE_P (t);
2476 TREE_SIDE_EFFECTS (ref)
2477 = (TREE_THIS_VOLATILE (ref) || TREE_SIDE_EFFECTS (pointer));
2481 else if (!(complain & tf_error))
2482 /* Don't emit any errors; we'll just return ERROR_MARK_NODE later. */
2484 /* `pointer' won't be an error_mark_node if we were given a
2485 pointer to member, so it's cool to check for this here. */
2486 else if (TYPE_PTR_TO_MEMBER_P (type))
2487 error ("invalid use of %qs on pointer to member", errorstring);
2488 else if (pointer != error_mark_node)
2491 error ("invalid type argument of %qs", errorstring);
2493 error ("invalid type argument");
2495 return error_mark_node;
2498 /* This handles expressions of the form "a[i]", which denotes
2501 This is logically equivalent in C to *(a+i), but we may do it differently.
2502 If A is a variable or a member, we generate a primitive ARRAY_REF.
2503 This avoids forcing the array out of registers, and can work on
2504 arrays that are not lvalues (for example, members of structures returned
2507 If INDEX is of some user-defined type, it must be converted to
2508 integer type. Otherwise, to make a compatible PLUS_EXPR, it
2509 will inherit the type of the array, which will be some pointer type. */
2512 build_array_ref (tree array, tree idx)
2516 error ("subscript missing in array reference");
2517 return error_mark_node;
2520 if (TREE_TYPE (array) == error_mark_node
2521 || TREE_TYPE (idx) == error_mark_node)
2522 return error_mark_node;
2524 /* If ARRAY is a COMPOUND_EXPR or COND_EXPR, move our reference
2526 switch (TREE_CODE (array))
2530 tree value = build_array_ref (TREE_OPERAND (array, 1), idx);
2531 return build2 (COMPOUND_EXPR, TREE_TYPE (value),
2532 TREE_OPERAND (array, 0), value);
2536 return build_conditional_expr
2537 (TREE_OPERAND (array, 0),
2538 build_array_ref (TREE_OPERAND (array, 1), idx),
2539 build_array_ref (TREE_OPERAND (array, 2), idx),
2540 tf_warning_or_error);
2546 if (TREE_CODE (TREE_TYPE (array)) == ARRAY_TYPE)
2550 warn_array_subscript_with_type_char (idx);
2552 if (!INTEGRAL_OR_UNSCOPED_ENUMERATION_TYPE_P (TREE_TYPE (idx)))
2554 error ("array subscript is not an integer");
2555 return error_mark_node;
2558 /* Apply integral promotions *after* noticing character types.
2559 (It is unclear why we do these promotions -- the standard
2560 does not say that we should. In fact, the natural thing would
2561 seem to be to convert IDX to ptrdiff_t; we're performing
2562 pointer arithmetic.) */
2563 idx = perform_integral_promotions (idx);
2565 /* An array that is indexed by a non-constant
2566 cannot be stored in a register; we must be able to do
2567 address arithmetic on its address.
2568 Likewise an array of elements of variable size. */
2569 if (TREE_CODE (idx) != INTEGER_CST
2570 || (COMPLETE_TYPE_P (TREE_TYPE (TREE_TYPE (array)))
2571 && (TREE_CODE (TYPE_SIZE (TREE_TYPE (TREE_TYPE (array))))
2574 if (!cxx_mark_addressable (array))
2575 return error_mark_node;
2578 /* An array that is indexed by a constant value which is not within
2579 the array bounds cannot be stored in a register either; because we
2580 would get a crash in store_bit_field/extract_bit_field when trying
2581 to access a non-existent part of the register. */
2582 if (TREE_CODE (idx) == INTEGER_CST
2583 && TYPE_DOMAIN (TREE_TYPE (array))
2584 && ! int_fits_type_p (idx, TYPE_DOMAIN (TREE_TYPE (array))))
2586 if (!cxx_mark_addressable (array))
2587 return error_mark_node;
2590 if (!lvalue_p (array))
2591 pedwarn (input_location, OPT_pedantic, "ISO C++ forbids subscripting non-lvalue array");
2593 /* Note in C++ it is valid to subscript a `register' array, since
2594 it is valid to take the address of something with that
2595 storage specification. */
2599 while (TREE_CODE (foo) == COMPONENT_REF)
2600 foo = TREE_OPERAND (foo, 0);
2601 if (TREE_CODE (foo) == VAR_DECL && DECL_REGISTER (foo))
2602 warning (OPT_Wextra, "subscripting array declared %<register%>");
2605 type = TREE_TYPE (TREE_TYPE (array));
2606 rval = build4 (ARRAY_REF, type, array, idx, NULL_TREE, NULL_TREE);
2607 /* Array ref is const/volatile if the array elements are
2608 or if the array is.. */
2609 TREE_READONLY (rval)
2610 |= (CP_TYPE_CONST_P (type) | TREE_READONLY (array));
2611 TREE_SIDE_EFFECTS (rval)
2612 |= (CP_TYPE_VOLATILE_P (type) | TREE_SIDE_EFFECTS (array));
2613 TREE_THIS_VOLATILE (rval)
2614 |= (CP_TYPE_VOLATILE_P (type) | TREE_THIS_VOLATILE (array));
2615 return require_complete_type (fold_if_not_in_template (rval));
2619 tree ar = default_conversion (array);
2620 tree ind = default_conversion (idx);
2622 /* Put the integer in IND to simplify error checking. */
2623 if (TREE_CODE (TREE_TYPE (ar)) == INTEGER_TYPE)
2630 if (ar == error_mark_node)
2633 if (TREE_CODE (TREE_TYPE (ar)) != POINTER_TYPE)
2635 error ("subscripted value is neither array nor pointer");
2636 return error_mark_node;
2638 if (TREE_CODE (TREE_TYPE (ind)) != INTEGER_TYPE)
2640 error ("array subscript is not an integer");
2641 return error_mark_node;
2644 warn_array_subscript_with_type_char (idx);
2646 return cp_build_indirect_ref (cp_build_binary_op (PLUS_EXPR, ar, ind,
2647 tf_warning_or_error),
2649 tf_warning_or_error);
2653 /* Resolve a pointer to member function. INSTANCE is the object
2654 instance to use, if the member points to a virtual member.
2656 This used to avoid checking for virtual functions if basetype
2657 has no virtual functions, according to an earlier ANSI draft.
2658 With the final ISO C++ rules, such an optimization is
2659 incorrect: A pointer to a derived member can be static_cast
2660 to pointer-to-base-member, as long as the dynamic object
2661 later has the right member. */
2664 get_member_function_from_ptrfunc (tree *instance_ptrptr, tree function)
2666 if (TREE_CODE (function) == OFFSET_REF)
2667 function = TREE_OPERAND (function, 1);
2669 if (TYPE_PTRMEMFUNC_P (TREE_TYPE (function)))
2671 tree idx, delta, e1, e2, e3, vtbl, basetype;
2672 tree fntype = TYPE_PTRMEMFUNC_FN_TYPE (TREE_TYPE (function));
2674 tree instance_ptr = *instance_ptrptr;
2675 tree instance_save_expr = 0;
2676 if (instance_ptr == error_mark_node)
2678 if (TREE_CODE (function) == PTRMEM_CST)
2680 /* Extracting the function address from a pmf is only
2681 allowed with -Wno-pmf-conversions. It only works for
2683 e1 = build_addr_func (PTRMEM_CST_MEMBER (function));
2684 e1 = convert (fntype, e1);
2689 error ("object missing in use of %qE", function);
2690 return error_mark_node;
2694 if (TREE_SIDE_EFFECTS (instance_ptr))
2695 instance_ptr = instance_save_expr = save_expr (instance_ptr);
2697 if (TREE_SIDE_EFFECTS (function))
2698 function = save_expr (function);
2700 /* Start by extracting all the information from the PMF itself. */
2701 e3 = pfn_from_ptrmemfunc (function);
2702 delta = delta_from_ptrmemfunc (function);
2703 idx = build1 (NOP_EXPR, vtable_index_type, e3);
2704 switch (TARGET_PTRMEMFUNC_VBIT_LOCATION)
2706 case ptrmemfunc_vbit_in_pfn:
2707 e1 = cp_build_binary_op (BIT_AND_EXPR, idx, integer_one_node,
2708 tf_warning_or_error);
2709 idx = cp_build_binary_op (MINUS_EXPR, idx, integer_one_node,
2710 tf_warning_or_error);
2713 case ptrmemfunc_vbit_in_delta:
2714 e1 = cp_build_binary_op (BIT_AND_EXPR, delta, integer_one_node,
2715 tf_warning_or_error);
2716 delta = cp_build_binary_op (RSHIFT_EXPR, delta, integer_one_node,
2717 tf_warning_or_error);
2724 /* Convert down to the right base before using the instance. A
2725 special case is that in a pointer to member of class C, C may
2726 be incomplete. In that case, the function will of course be
2727 a member of C, and no conversion is required. In fact,
2728 lookup_base will fail in that case, because incomplete
2729 classes do not have BINFOs. */
2730 basetype = TYPE_METHOD_BASETYPE (TREE_TYPE (fntype));
2731 if (!same_type_ignoring_top_level_qualifiers_p
2732 (basetype, TREE_TYPE (TREE_TYPE (instance_ptr))))
2734 basetype = lookup_base (TREE_TYPE (TREE_TYPE (instance_ptr)),
2735 basetype, ba_check, NULL);
2736 instance_ptr = build_base_path (PLUS_EXPR, instance_ptr, basetype,
2738 if (instance_ptr == error_mark_node)
2739 return error_mark_node;
2741 /* ...and then the delta in the PMF. */
2742 instance_ptr = build2 (POINTER_PLUS_EXPR, TREE_TYPE (instance_ptr),
2743 instance_ptr, fold_convert (sizetype, delta));
2745 /* Hand back the adjusted 'this' argument to our caller. */
2746 *instance_ptrptr = instance_ptr;
2748 /* Next extract the vtable pointer from the object. */
2749 vtbl = build1 (NOP_EXPR, build_pointer_type (vtbl_ptr_type_node),
2751 vtbl = cp_build_indirect_ref (vtbl, NULL, tf_warning_or_error);
2753 /* Finally, extract the function pointer from the vtable. */
2754 e2 = fold_build2 (POINTER_PLUS_EXPR, TREE_TYPE (vtbl), vtbl,
2755 fold_convert (sizetype, idx));
2756 e2 = cp_build_indirect_ref (e2, NULL, tf_warning_or_error);
2757 TREE_CONSTANT (e2) = 1;
2759 /* When using function descriptors, the address of the
2760 vtable entry is treated as a function pointer. */
2761 if (TARGET_VTABLE_USES_DESCRIPTORS)
2762 e2 = build1 (NOP_EXPR, TREE_TYPE (e2),
2763 cp_build_unary_op (ADDR_EXPR, e2, /*noconvert=*/1,
2764 tf_warning_or_error));
2766 e2 = fold_convert (TREE_TYPE (e3), e2);
2767 e1 = build_conditional_expr (e1, e2, e3, tf_warning_or_error);
2769 /* Make sure this doesn't get evaluated first inside one of the
2770 branches of the COND_EXPR. */
2771 if (instance_save_expr)
2772 e1 = build2 (COMPOUND_EXPR, TREE_TYPE (e1),
2773 instance_save_expr, e1);
2780 /* Used by the C-common bits. */
2782 build_function_call (tree function, tree params)
2784 return cp_build_function_call (function, params, tf_warning_or_error);
2788 cp_build_function_call (tree function, tree params, tsubst_flags_t complain)
2790 tree fntype, fndecl;
2791 tree name = NULL_TREE;
2793 tree original = function;
2794 int nargs, parm_types_len;
2798 /* For Objective-C, convert any calls via a cast to OBJC_TYPE_REF
2799 expressions, like those used for ObjC messenger dispatches. */
2800 function = objc_rewrite_function_call (function, params);
2802 /* build_c_cast puts on a NOP_EXPR to make the result not an lvalue.
2803 Strip such NOP_EXPRs, since FUNCTION is used in non-lvalue context. */
2804 if (TREE_CODE (function) == NOP_EXPR
2805 && TREE_TYPE (function) == TREE_TYPE (TREE_OPERAND (function, 0)))
2806 function = TREE_OPERAND (function, 0);
2808 if (TREE_CODE (function) == FUNCTION_DECL)
2810 name = DECL_NAME (function);
2812 mark_used (function);
2815 /* Convert anything with function type to a pointer-to-function. */
2816 if (DECL_MAIN_P (function) && (complain & tf_error))
2817 pedwarn (input_location, OPT_pedantic,
2818 "ISO C++ forbids calling %<::main%> from within program");
2820 function = build_addr_func (function);
2826 function = build_addr_func (function);
2829 if (function == error_mark_node)
2830 return error_mark_node;
2832 fntype = TREE_TYPE (function);
2834 if (TYPE_PTRMEMFUNC_P (fntype))
2836 if (complain & tf_error)
2837 error ("must use %<.*%> or %<->*%> to call pointer-to-member "
2838 "function in %<%E (...)%>, e.g. %<(... ->* %E) (...)%>",
2839 original, original);
2840 return error_mark_node;
2843 is_method = (TREE_CODE (fntype) == POINTER_TYPE
2844 && TREE_CODE (TREE_TYPE (fntype)) == METHOD_TYPE);
2846 if (!((TREE_CODE (fntype) == POINTER_TYPE
2847 && TREE_CODE (TREE_TYPE (fntype)) == FUNCTION_TYPE)
2849 || TREE_CODE (function) == TEMPLATE_ID_EXPR))
2851 if (complain & tf_error)
2852 error ("%qE cannot be used as a function", original);
2853 return error_mark_node;
2856 /* fntype now gets the type of function pointed to. */
2857 fntype = TREE_TYPE (fntype);
2858 parm_types = TYPE_ARG_TYPES (fntype);
2860 /* Allocate storage for converted arguments. */
2861 parm_types_len = list_length (parm_types);
2862 nargs = list_length (params);
2863 if (parm_types_len > nargs)
2864 nargs = parm_types_len;
2865 argarray = (tree *) alloca (nargs * sizeof (tree));
2867 /* Convert the parameters to the types declared in the
2868 function prototype, or apply default promotions. */
2869 nargs = convert_arguments (nargs, argarray, parm_types,
2870 params, fndecl, LOOKUP_NORMAL,
2873 return error_mark_node;
2875 /* Check for errors in format strings and inappropriately
2877 check_function_arguments (TYPE_ATTRIBUTES (fntype), nargs, argarray,
2880 return build_cxx_call (function, nargs, argarray);
2883 /* Convert the actual parameter expressions in the list VALUES
2884 to the types in the list TYPELIST.
2885 If parmdecls is exhausted, or when an element has NULL as its type,
2886 perform the default conversions.
2888 Store the converted arguments in ARGARRAY. NARGS is the size of this array.
2890 NAME is an IDENTIFIER_NODE or 0. It is used only for error messages.
2892 This is also where warnings about wrong number of args are generated.
2894 Returns the actual number of arguments processed (which might be less
2895 than NARGS), or -1 on error.
2897 VALUES is a chain of TREE_LIST nodes with the elements of the list
2898 in the TREE_VALUE slots of those nodes.
2900 In C++, unspecified trailing parameters can be filled in with their
2901 default arguments, if such were specified. Do so here. */
2904 convert_arguments (int nargs, tree *argarray,
2905 tree typelist, tree values, tree fndecl, int flags,
2906 tsubst_flags_t complain)
2908 tree typetail, valtail;
2909 const char *called_thing = 0;
2912 /* Argument passing is always copy-initialization. */
2913 flags |= LOOKUP_ONLYCONVERTING;
2917 if (TREE_CODE (TREE_TYPE (fndecl)) == METHOD_TYPE)
2919 if (DECL_NAME (fndecl) == NULL_TREE
2920 || IDENTIFIER_HAS_TYPE_VALUE (DECL_NAME (fndecl)))
2921 called_thing = "constructor";
2923 called_thing = "member function";
2926 called_thing = "function";
2929 for (valtail = values, typetail = typelist;
2931 valtail = TREE_CHAIN (valtail), i++)
2933 tree type = typetail ? TREE_VALUE (typetail) : 0;
2934 tree val = TREE_VALUE (valtail);
2936 if (val == error_mark_node || type == error_mark_node)
2939 if (type == void_type_node)
2941 if (complain & tf_error)
2945 error ("too many arguments to %s %q+#D",
2946 called_thing, fndecl);
2947 error ("at this point in file");
2950 error ("too many arguments to function");
2957 /* build_c_cast puts on a NOP_EXPR to make the result not an lvalue.
2958 Strip such NOP_EXPRs, since VAL is used in non-lvalue context. */
2959 if (TREE_CODE (val) == NOP_EXPR
2960 && TREE_TYPE (val) == TREE_TYPE (TREE_OPERAND (val, 0))
2961 && (type == 0 || TREE_CODE (type) != REFERENCE_TYPE))
2962 val = TREE_OPERAND (val, 0);
2964 if (type == 0 || TREE_CODE (type) != REFERENCE_TYPE)
2966 if (TREE_CODE (TREE_TYPE (val)) == ARRAY_TYPE
2967 || TREE_CODE (TREE_TYPE (val)) == FUNCTION_TYPE
2968 || TREE_CODE (TREE_TYPE (val)) == METHOD_TYPE)
2969 val = decay_conversion (val);
2972 if (val == error_mark_node)
2977 /* Formal parm type is specified by a function prototype. */
2980 if (!COMPLETE_TYPE_P (complete_type (type)))
2982 if (complain & tf_error)
2985 error ("parameter %P of %qD has incomplete type %qT",
2988 error ("parameter %P has incomplete type %qT", i, type);
2990 parmval = error_mark_node;
2994 parmval = convert_for_initialization
2995 (NULL_TREE, type, val, flags,
2996 "argument passing", fndecl, i, complain);
2997 parmval = convert_for_arg_passing (type, parmval);
3000 if (parmval == error_mark_node)
3003 argarray[i] = parmval;
3007 if (fndecl && DECL_BUILT_IN (fndecl)
3008 && DECL_FUNCTION_CODE (fndecl) == BUILT_IN_CONSTANT_P)
3009 /* Don't do ellipsis conversion for __built_in_constant_p
3010 as this will result in spurious warnings for non-POD
3012 val = require_complete_type (val);
3014 val = convert_arg_to_ellipsis (val);
3020 typetail = TREE_CHAIN (typetail);
3023 if (typetail != 0 && typetail != void_list_node)
3025 /* See if there are default arguments that can be used. Because
3026 we hold default arguments in the FUNCTION_TYPE (which is so
3027 wrong), we can see default parameters here from deduced
3028 contexts (and via typeof) for indirect function calls.
3029 Fortunately we know whether we have a function decl to
3030 provide default arguments in a language conformant
3032 if (fndecl && TREE_PURPOSE (typetail)
3033 && TREE_CODE (TREE_PURPOSE (typetail)) != DEFAULT_ARG)
3035 for (; typetail != void_list_node; ++i)
3038 = convert_default_arg (TREE_VALUE (typetail),
3039 TREE_PURPOSE (typetail),
3042 if (parmval == error_mark_node)
3045 argarray[i] = parmval;
3046 typetail = TREE_CHAIN (typetail);
3047 /* ends with `...'. */
3048 if (typetail == NULL_TREE)
3054 if (complain & tf_error)
3058 error ("too few arguments to %s %q+#D",
3059 called_thing, fndecl);
3060 error ("at this point in file");
3063 error ("too few arguments to function");
3069 gcc_assert (i <= nargs);
3073 /* Build a binary-operation expression, after performing default
3074 conversions on the operands. CODE is the kind of expression to
3075 build. ARG1 and ARG2 are the arguments. ARG1_CODE and ARG2_CODE
3076 are the tree codes which correspond to ARG1 and ARG2 when issuing
3077 warnings about possibly misplaced parentheses. They may differ
3078 from the TREE_CODE of ARG1 and ARG2 if the parser has done constant
3079 folding (e.g., if the parser sees "a | 1 + 1", it may call this
3080 routine with ARG2 being an INTEGER_CST and ARG2_CODE == PLUS_EXPR).
3081 To avoid issuing any parentheses warnings, pass ARG1_CODE and/or
3082 ARG2_CODE as ERROR_MARK. */
3085 build_x_binary_op (enum tree_code code, tree arg1, enum tree_code arg1_code,
3086 tree arg2, enum tree_code arg2_code, bool *overloaded_p,
3087 tsubst_flags_t complain)
3096 if (processing_template_decl)
3098 if (type_dependent_expression_p (arg1)
3099 || type_dependent_expression_p (arg2))
3100 return build_min_nt (code, arg1, arg2);
3101 arg1 = build_non_dependent_expr (arg1);
3102 arg2 = build_non_dependent_expr (arg2);
3105 if (code == DOTSTAR_EXPR)
3106 expr = build_m_component_ref (arg1, arg2);
3108 expr = build_new_op (code, LOOKUP_NORMAL, arg1, arg2, NULL_TREE,
3109 overloaded_p, complain);
3111 /* Check for cases such as x+y<<z which users are likely to
3112 misinterpret. But don't warn about obj << x + y, since that is a
3113 common idiom for I/O. */
3114 if (warn_parentheses
3115 && !processing_template_decl
3116 && !error_operand_p (arg1)
3117 && !error_operand_p (arg2)
3118 && (code != LSHIFT_EXPR
3119 || !CLASS_TYPE_P (TREE_TYPE (arg1))))
3120 warn_about_parentheses (code, arg1_code, arg2_code);
3122 if (processing_template_decl && expr != error_mark_node)
3123 return build_min_non_dep (code, expr, orig_arg1, orig_arg2);
3128 /* For the c-common bits. */
3130 build_binary_op (enum tree_code code, tree op0, tree op1,
3131 int convert_p ATTRIBUTE_UNUSED)
3133 return cp_build_binary_op(code, op0, op1, tf_warning_or_error);
3137 /* Build a binary-operation expression without default conversions.
3138 CODE is the kind of expression to build.
3139 This function differs from `build' in several ways:
3140 the data type of the result is computed and recorded in it,
3141 warnings are generated if arg data types are invalid,
3142 special handling for addition and subtraction of pointers is known,
3143 and some optimization is done (operations on narrow ints
3144 are done in the narrower type when that gives the same result).
3145 Constant folding is also done before the result is returned.
3147 Note that the operands will never have enumeral types
3148 because either they have just had the default conversions performed
3149 or they have both just been converted to some other type in which
3150 the arithmetic is to be done.
3152 C++: must do special pointer arithmetic when implementing
3153 multiple inheritance, and deal with pointer to member functions. */
3156 cp_build_binary_op (enum tree_code code, tree orig_op0, tree orig_op1,
3157 tsubst_flags_t complain)
3160 enum tree_code code0, code1;
3162 const char *invalid_op_diag;
3164 /* Expression code to give to the expression when it is built.
3165 Normally this is CODE, which is what the caller asked for,
3166 but in some special cases we change it. */
3167 enum tree_code resultcode = code;
3169 /* Data type in which the computation is to be performed.
3170 In the simplest cases this is the common type of the arguments. */
3171 tree result_type = NULL;
3173 /* Nonzero means operands have already been type-converted
3174 in whatever way is necessary.
3175 Zero means they need to be converted to RESULT_TYPE. */
3178 /* Nonzero means create the expression with this type, rather than
3180 tree build_type = 0;
3182 /* Nonzero means after finally constructing the expression
3183 convert it to this type. */
3184 tree final_type = 0;
3188 /* Nonzero if this is an operation like MIN or MAX which can
3189 safely be computed in short if both args are promoted shorts.
3190 Also implies COMMON.
3191 -1 indicates a bitwise operation; this makes a difference
3192 in the exact conditions for when it is safe to do the operation
3193 in a narrower mode. */
3196 /* Nonzero if this is a comparison operation;
3197 if both args are promoted shorts, compare the original shorts.
3198 Also implies COMMON. */
3199 int short_compare = 0;
3201 /* Nonzero means set RESULT_TYPE to the common type of the args. */
3204 /* True if both operands have arithmetic type. */
3205 bool arithmetic_types_p;
3207 /* Apply default conversions. */
3211 if (code == TRUTH_AND_EXPR || code == TRUTH_ANDIF_EXPR
3212 || code == TRUTH_OR_EXPR || code == TRUTH_ORIF_EXPR
3213 || code == TRUTH_XOR_EXPR)
3215 if (!really_overloaded_fn (op0))
3216 op0 = decay_conversion (op0);
3217 if (!really_overloaded_fn (op1))
3218 op1 = decay_conversion (op1);
3222 if (!really_overloaded_fn (op0))
3223 op0 = default_conversion (op0);
3224 if (!really_overloaded_fn (op1))
3225 op1 = default_conversion (op1);
3228 /* Strip NON_LVALUE_EXPRs, etc., since we aren't using as an lvalue. */
3229 STRIP_TYPE_NOPS (op0);
3230 STRIP_TYPE_NOPS (op1);
3232 /* DTRT if one side is an overloaded function, but complain about it. */
3233 if (type_unknown_p (op0))
3235 tree t = instantiate_type (TREE_TYPE (op1), op0, tf_none);
3236 if (t != error_mark_node)
3238 if (complain & tf_error)
3239 permerror (input_location, "assuming cast to type %qT from overloaded function",
3244 if (type_unknown_p (op1))
3246 tree t = instantiate_type (TREE_TYPE (op0), op1, tf_none);
3247 if (t != error_mark_node)
3249 if (complain & tf_error)
3250 permerror (input_location, "assuming cast to type %qT from overloaded function",
3256 type0 = TREE_TYPE (op0);
3257 type1 = TREE_TYPE (op1);
3259 /* The expression codes of the data types of the arguments tell us
3260 whether the arguments are integers, floating, pointers, etc. */
3261 code0 = TREE_CODE (type0);
3262 code1 = TREE_CODE (type1);
3264 /* If an error was already reported for one of the arguments,
3265 avoid reporting another error. */
3267 if (code0 == ERROR_MARK || code1 == ERROR_MARK)
3268 return error_mark_node;
3270 if ((invalid_op_diag
3271 = targetm.invalid_binary_op (code, type0, type1)))
3273 error (invalid_op_diag);
3274 return error_mark_node;
3280 /* Subtraction of two similar pointers.
3281 We must subtract them as integers, then divide by object size. */
3282 if (code0 == POINTER_TYPE && code1 == POINTER_TYPE
3283 && same_type_ignoring_top_level_qualifiers_p (TREE_TYPE (type0),
3285 return pointer_diff (op0, op1, common_type (type0, type1));
3286 /* In all other cases except pointer - int, the usual arithmetic
3288 else if (!(code0 == POINTER_TYPE && code1 == INTEGER_TYPE))
3293 /* The pointer - int case is just like pointer + int; fall
3296 if ((code0 == POINTER_TYPE || code1 == POINTER_TYPE)
3297 && (code0 == INTEGER_TYPE || code1 == INTEGER_TYPE))
3301 ptr_operand = ((code0 == POINTER_TYPE) ? op0 : op1);
3302 int_operand = ((code0 == INTEGER_TYPE) ? op0 : op1);
3303 if (processing_template_decl)
3305 result_type = TREE_TYPE (ptr_operand);
3308 return cp_pointer_int_sum (code,
3319 case TRUNC_DIV_EXPR:
3321 case FLOOR_DIV_EXPR:
3322 case ROUND_DIV_EXPR:
3323 case EXACT_DIV_EXPR:
3324 if ((code0 == INTEGER_TYPE || code0 == REAL_TYPE
3325 || code0 == COMPLEX_TYPE || code0 == VECTOR_TYPE)
3326 && (code1 == INTEGER_TYPE || code1 == REAL_TYPE
3327 || code1 == COMPLEX_TYPE || code1 == VECTOR_TYPE))
3329 enum tree_code tcode0 = code0, tcode1 = code1;
3331 warn_for_div_by_zero (op1);
3333 if (tcode0 == COMPLEX_TYPE || tcode0 == VECTOR_TYPE)
3334 tcode0 = TREE_CODE (TREE_TYPE (TREE_TYPE (op0)));
3335 if (tcode1 == COMPLEX_TYPE || tcode1 == VECTOR_TYPE)
3336 tcode1 = TREE_CODE (TREE_TYPE (TREE_TYPE (op1)));
3338 if (!(tcode0 == INTEGER_TYPE && tcode1 == INTEGER_TYPE))
3339 resultcode = RDIV_EXPR;
3341 /* When dividing two signed integers, we have to promote to int.
3342 unless we divide by a constant != -1. Note that default
3343 conversion will have been performed on the operands at this
3344 point, so we have to dig out the original type to find out if
3346 shorten = ((TREE_CODE (op0) == NOP_EXPR
3347 && TYPE_UNSIGNED (TREE_TYPE (TREE_OPERAND (op0, 0))))
3348 || (TREE_CODE (op1) == INTEGER_CST
3349 && ! integer_all_onesp (op1)));
3358 if ((code0 == INTEGER_TYPE && code1 == INTEGER_TYPE)
3359 || (code0 == VECTOR_TYPE && code1 == VECTOR_TYPE
3360 && !VECTOR_FLOAT_TYPE_P (type0)
3361 && !VECTOR_FLOAT_TYPE_P (type1)))
3365 case TRUNC_MOD_EXPR:
3366 case FLOOR_MOD_EXPR:
3367 warn_for_div_by_zero (op1);
3369 if (code0 == INTEGER_TYPE && code1 == INTEGER_TYPE)
3371 /* Although it would be tempting to shorten always here, that loses
3372 on some targets, since the modulo instruction is undefined if the
3373 quotient can't be represented in the computation mode. We shorten
3374 only if unsigned or if dividing by something we know != -1. */
3375 shorten = ((TREE_CODE (op0) == NOP_EXPR
3376 && TYPE_UNSIGNED (TREE_TYPE (TREE_OPERAND (op0, 0))))
3377 || (TREE_CODE (op1) == INTEGER_CST
3378 && ! integer_all_onesp (op1)));
3383 case TRUTH_ANDIF_EXPR:
3384 case TRUTH_ORIF_EXPR:
3385 case TRUTH_AND_EXPR:
3387 result_type = boolean_type_node;
3390 /* Shift operations: result has same type as first operand;
3391 always convert second operand to int.
3392 Also set SHORT_SHIFT if shifting rightward. */
3395 if (code0 == INTEGER_TYPE && code1 == INTEGER_TYPE)
3397 result_type = type0;
3398 if (TREE_CODE (op1) == INTEGER_CST)
3400 if (tree_int_cst_lt (op1, integer_zero_node))
3402 if (complain & tf_warning)
3403 warning (0, "right shift count is negative");
3407 if (compare_tree_int (op1, TYPE_PRECISION (type0)) >= 0
3408 && (complain & tf_warning))
3409 warning (0, "right shift count >= width of type");
3412 /* Convert the shift-count to an integer, regardless of
3413 size of value being shifted. */
3414 if (TYPE_MAIN_VARIANT (TREE_TYPE (op1)) != integer_type_node)
3415 op1 = cp_convert (integer_type_node, op1);
3416 /* Avoid converting op1 to result_type later. */
3422 if (code0 == INTEGER_TYPE && code1 == INTEGER_TYPE)
3424 result_type = type0;
3425 if (TREE_CODE (op1) == INTEGER_CST)
3427 if (tree_int_cst_lt (op1, integer_zero_node))
3429 if (complain & tf_warning)
3430 warning (0, "left shift count is negative");
3432 else if (compare_tree_int (op1, TYPE_PRECISION (type0)) >= 0)
3434 if (complain & tf_warning)
3435 warning (0, "left shift count >= width of type");
3438 /* Convert the shift-count to an integer, regardless of
3439 size of value being shifted. */
3440 if (TYPE_MAIN_VARIANT (TREE_TYPE (op1)) != integer_type_node)
3441 op1 = cp_convert (integer_type_node, op1);
3442 /* Avoid converting op1 to result_type later. */
3449 if (code0 == INTEGER_TYPE && code1 == INTEGER_TYPE)
3451 result_type = type0;
3452 if (TREE_CODE (op1) == INTEGER_CST)
3454 if (tree_int_cst_lt (op1, integer_zero_node))
3456 if (complain & tf_warning)
3457 warning (0, (code == LROTATE_EXPR)
3458 ? G_("left rotate count is negative")
3459 : G_("right rotate count is negative"));
3461 else if (compare_tree_int (op1, TYPE_PRECISION (type0)) >= 0)
3463 if (complain & tf_warning)
3464 warning (0, (code == LROTATE_EXPR)
3465 ? G_("left rotate count >= width of type")
3466 : G_("right rotate count >= width of type"));
3469 /* Convert the shift-count to an integer, regardless of
3470 size of value being shifted. */
3471 if (TYPE_MAIN_VARIANT (TREE_TYPE (op1)) != integer_type_node)
3472 op1 = cp_convert (integer_type_node, op1);
3478 if ((complain & tf_warning)
3479 && (FLOAT_TYPE_P (type0) || FLOAT_TYPE_P (type1)))
3480 warning (OPT_Wfloat_equal,
3481 "comparing floating point with == or != is unsafe");
3482 if ((complain & tf_warning)
3483 && ((TREE_CODE (orig_op0) == STRING_CST && !integer_zerop (op1))
3484 || (TREE_CODE (orig_op1) == STRING_CST && !integer_zerop (op0))))
3485 warning (OPT_Waddress, "comparison with string literal results in unspecified behaviour");
3487 build_type = boolean_type_node;
3488 if ((code0 == INTEGER_TYPE || code0 == REAL_TYPE
3489 || code0 == COMPLEX_TYPE)
3490 && (code1 == INTEGER_TYPE || code1 == REAL_TYPE
3491 || code1 == COMPLEX_TYPE))
3493 else if ((code0 == POINTER_TYPE && code1 == POINTER_TYPE)
3494 || (TYPE_PTRMEM_P (type0) && TYPE_PTRMEM_P (type1)))
3495 result_type = composite_pointer_type (type0, type1, op0, op1,
3496 "comparison", complain);
3497 else if ((code0 == POINTER_TYPE || TYPE_PTRMEM_P (type0))
3498 && null_ptr_cst_p (op1))
3500 if (TREE_CODE (op0) == ADDR_EXPR
3501 && decl_with_nonnull_addr_p (TREE_OPERAND (op0, 0)))
3503 if (complain & tf_warning)
3504 warning (OPT_Waddress, "the address of %qD will never be NULL",
3505 TREE_OPERAND (op0, 0));
3507 result_type = type0;
3509 else if ((code1 == POINTER_TYPE || TYPE_PTRMEM_P (type1))
3510 && null_ptr_cst_p (op0))
3512 if (TREE_CODE (op1) == ADDR_EXPR
3513 && decl_with_nonnull_addr_p (TREE_OPERAND (op1, 0)))
3515 if (complain & tf_warning)
3516 warning (OPT_Waddress, "the address of %qD will never be NULL",
3517 TREE_OPERAND (op1, 0));
3519 result_type = type1;
3521 else if (code0 == POINTER_TYPE && code1 == INTEGER_TYPE)
3523 result_type = type0;
3524 if (complain & tf_error)
3525 permerror (input_location, "ISO C++ forbids comparison between pointer and integer");
3527 return error_mark_node;
3529 else if (code0 == INTEGER_TYPE && code1 == POINTER_TYPE)
3531 result_type = type1;
3532 if (complain & tf_error)
3533 permerror (input_location, "ISO C++ forbids comparison between pointer and integer");
3535 return error_mark_node;
3537 else if (TYPE_PTRMEMFUNC_P (type0) && null_ptr_cst_p (op1))
3539 if (TARGET_PTRMEMFUNC_VBIT_LOCATION
3540 == ptrmemfunc_vbit_in_delta)
3542 tree pfn0 = pfn_from_ptrmemfunc (op0);
3543 tree delta0 = delta_from_ptrmemfunc (op0);
3544 tree e1 = cp_build_binary_op (EQ_EXPR,
3546 fold_convert (TREE_TYPE (pfn0),
3549 tree e2 = cp_build_binary_op (BIT_AND_EXPR,
3553 e2 = cp_build_binary_op (EQ_EXPR, e2, integer_zero_node,
3555 op0 = cp_build_binary_op (TRUTH_ANDIF_EXPR, e1, e2,
3557 op1 = cp_convert (TREE_TYPE (op0), integer_one_node);
3561 op0 = build_ptrmemfunc_access_expr (op0, pfn_identifier);
3562 op1 = cp_convert (TREE_TYPE (op0), integer_zero_node);
3564 result_type = TREE_TYPE (op0);
3566 else if (TYPE_PTRMEMFUNC_P (type1) && null_ptr_cst_p (op0))
3567 return cp_build_binary_op (code, op1, op0, complain);
3568 else if (TYPE_PTRMEMFUNC_P (type0) && TYPE_PTRMEMFUNC_P (type1))
3571 /* E will be the final comparison. */
3573 /* E1 and E2 are for scratch. */
3581 type = composite_pointer_type (type0, type1, op0, op1, "comparison",
3584 if (!same_type_p (TREE_TYPE (op0), type))
3585 op0 = cp_convert_and_check (type, op0);
3586 if (!same_type_p (TREE_TYPE (op1), type))
3587 op1 = cp_convert_and_check (type, op1);
3589 if (op0 == error_mark_node || op1 == error_mark_node)
3590 return error_mark_node;
3592 if (TREE_SIDE_EFFECTS (op0))
3593 op0 = save_expr (op0);
3594 if (TREE_SIDE_EFFECTS (op1))
3595 op1 = save_expr (op1);
3597 pfn0 = pfn_from_ptrmemfunc (op0);
3598 pfn1 = pfn_from_ptrmemfunc (op1);
3599 delta0 = delta_from_ptrmemfunc (op0);
3600 delta1 = delta_from_ptrmemfunc (op1);
3601 if (TARGET_PTRMEMFUNC_VBIT_LOCATION
3602 == ptrmemfunc_vbit_in_delta)
3607 && ((op0.delta == op1.delta)
3608 || (!op0.pfn && op0.delta & 1 == 0
3609 && op1.delta & 1 == 0))
3611 The reason for the `!op0.pfn' bit is that a NULL
3612 pointer-to-member is any member with a zero PFN and
3613 LSB of the DELTA field is 0. */
3615 e1 = cp_build_binary_op (BIT_AND_EXPR,
3619 e1 = cp_build_binary_op (EQ_EXPR, e1, integer_zero_node,
3621 e2 = cp_build_binary_op (BIT_AND_EXPR,
3625 e2 = cp_build_binary_op (EQ_EXPR, e2, integer_zero_node,
3627 e1 = cp_build_binary_op (TRUTH_ANDIF_EXPR, e2, e1,
3629 e2 = cp_build_binary_op (EQ_EXPR,
3631 fold_convert (TREE_TYPE (pfn0),
3634 e2 = cp_build_binary_op (TRUTH_ANDIF_EXPR, e2, e1, complain);
3635 e1 = cp_build_binary_op (EQ_EXPR, delta0, delta1, complain);
3636 e1 = cp_build_binary_op (TRUTH_ORIF_EXPR, e1, e2, complain);
3643 && (!op0.pfn || op0.delta == op1.delta))
3645 The reason for the `!op0.pfn' bit is that a NULL
3646 pointer-to-member is any member with a zero PFN; the
3647 DELTA field is unspecified. */
3649 e1 = cp_build_binary_op (EQ_EXPR, delta0, delta1, complain);
3650 e2 = cp_build_binary_op (EQ_EXPR,
3652 fold_convert (TREE_TYPE (pfn0),
3655 e1 = cp_build_binary_op (TRUTH_ORIF_EXPR, e1, e2, complain);
3657 e2 = build2 (EQ_EXPR, boolean_type_node, pfn0, pfn1);
3658 e = cp_build_binary_op (TRUTH_ANDIF_EXPR, e2, e1, complain);
3659 if (code == EQ_EXPR)
3661 return cp_build_binary_op (EQ_EXPR, e, integer_zero_node, complain);
3665 gcc_assert (!TYPE_PTRMEMFUNC_P (type0)
3666 || !same_type_p (TYPE_PTRMEMFUNC_FN_TYPE (type0),
3668 gcc_assert (!TYPE_PTRMEMFUNC_P (type1)
3669 || !same_type_p (TYPE_PTRMEMFUNC_FN_TYPE (type1),
3677 if ((code0 == INTEGER_TYPE || code0 == REAL_TYPE)
3678 && (code1 == INTEGER_TYPE || code1 == REAL_TYPE))
3680 else if (code0 == POINTER_TYPE && code1 == POINTER_TYPE)
3681 result_type = composite_pointer_type (type0, type1, op0, op1,
3682 "comparison", complain);
3689 if (TREE_CODE (orig_op0) == STRING_CST
3690 || TREE_CODE (orig_op1) == STRING_CST)
3692 if (complain & tf_warning)
3693 warning (OPT_Waddress, "comparison with string literal results in unspecified behaviour");
3696 build_type = boolean_type_node;
3697 if ((code0 == INTEGER_TYPE || code0 == REAL_TYPE)
3698 && (code1 == INTEGER_TYPE || code1 == REAL_TYPE))
3700 else if (code0 == POINTER_TYPE && code1 == POINTER_TYPE)
3701 result_type = composite_pointer_type (type0, type1, op0, op1,
3702 "comparison", complain);
3703 else if (code0 == POINTER_TYPE && TREE_CODE (op1) == INTEGER_CST
3704 && integer_zerop (op1))
3705 result_type = type0;
3706 else if (code1 == POINTER_TYPE && TREE_CODE (op0) == INTEGER_CST
3707 && integer_zerop (op0))
3708 result_type = type1;
3709 else if (code0 == POINTER_TYPE && code1 == INTEGER_TYPE)
3711 result_type = type0;
3712 if (complain & tf_error)
3713 permerror (input_location, "ISO C++ forbids comparison between pointer and integer");
3715 return error_mark_node;
3717 else if (code0 == INTEGER_TYPE && code1 == POINTER_TYPE)
3719 result_type = type1;
3720 if (complain & tf_error)
3721 permerror (input_location, "ISO C++ forbids comparison between pointer and integer");
3723 return error_mark_node;
3727 case UNORDERED_EXPR:
3734 build_type = integer_type_node;
3735 if (code0 != REAL_TYPE || code1 != REAL_TYPE)
3737 if (complain & tf_error)
3738 error ("unordered comparison on non-floating point argument");
3739 return error_mark_node;
3748 if (((code0 == INTEGER_TYPE || code0 == REAL_TYPE || code0 == COMPLEX_TYPE)
3749 && (code1 == INTEGER_TYPE || code1 == REAL_TYPE
3750 || code1 == COMPLEX_TYPE)))
3751 arithmetic_types_p = 1;
3754 arithmetic_types_p = 0;
3755 /* Vector arithmetic is only allowed when both sides are vectors. */
3756 if (code0 == VECTOR_TYPE && code1 == VECTOR_TYPE)
3758 if (!tree_int_cst_equal (TYPE_SIZE (type0), TYPE_SIZE (type1))
3759 || !same_scalar_type_ignoring_signedness (TREE_TYPE (type0),
3762 binary_op_error (code, type0, type1);
3763 return error_mark_node;
3765 arithmetic_types_p = 1;
3768 /* Determine the RESULT_TYPE, if it is not already known. */
3770 && arithmetic_types_p
3771 && (shorten || common || short_compare))
3772 result_type = common_type (type0, type1);
3776 if (complain & tf_error)
3777 error ("invalid operands of types %qT and %qT to binary %qO",
3778 TREE_TYPE (orig_op0), TREE_TYPE (orig_op1), code);
3779 return error_mark_node;
3782 /* If we're in a template, the only thing we need to know is the
3784 if (processing_template_decl)
3786 /* Since the middle-end checks the type when doing a build2, we
3787 need to build the tree in pieces. This built tree will never
3788 get out of the front-end as we replace it when instantiating
3790 tree tmp = build2 (resultcode,
3791 build_type ? build_type : result_type,
3793 TREE_OPERAND (tmp, 0) = op0;
3797 if (arithmetic_types_p)
3799 int none_complex = (code0 != COMPLEX_TYPE && code1 != COMPLEX_TYPE);
3801 /* For certain operations (which identify themselves by shorten != 0)
3802 if both args were extended from the same smaller type,
3803 do the arithmetic in that type and then extend.
3805 shorten !=0 and !=1 indicates a bitwise operation.
3806 For them, this optimization is safe only if
3807 both args are zero-extended or both are sign-extended.
3808 Otherwise, we might change the result.
3809 E.g., (short)-1 | (unsigned short)-1 is (int)-1
3810 but calculated in (unsigned short) it would be (unsigned short)-1. */
3812 if (shorten && none_complex)
3814 final_type = result_type;
3815 result_type = shorten_binary_op (result_type, op0, op1,
3819 /* Comparison operations are shortened too but differently.
3820 They identify themselves by setting short_compare = 1. */
3824 /* Don't write &op0, etc., because that would prevent op0
3825 from being kept in a register.
3826 Instead, make copies of the our local variables and
3827 pass the copies by reference, then copy them back afterward. */
3828 tree xop0 = op0, xop1 = op1, xresult_type = result_type;
3829 enum tree_code xresultcode = resultcode;
3831 = shorten_compare (&xop0, &xop1, &xresult_type, &xresultcode);
3833 return cp_convert (boolean_type_node, val);
3834 op0 = xop0, op1 = xop1;
3836 resultcode = xresultcode;
3839 if ((short_compare || code == MIN_EXPR || code == MAX_EXPR)
3840 && warn_sign_compare
3841 /* Do not warn until the template is instantiated; we cannot
3842 bound the ranges of the arguments until that point. */
3843 && !processing_template_decl
3844 && (complain & tf_warning))
3846 warn_for_sign_compare (orig_op0, orig_op1, op0, op1,
3847 result_type, resultcode);
3851 /* Issue warnings about peculiar, but valid, uses of NULL. */
3852 if ((orig_op0 == null_node || orig_op1 == null_node)
3853 /* It's reasonable to use pointer values as operands of &&
3854 and ||, so NULL is no exception. */
3855 && code != TRUTH_ANDIF_EXPR && code != TRUTH_ORIF_EXPR
3856 && ( /* Both are NULL (or 0) and the operation was not a comparison. */
3857 (null_ptr_cst_p (orig_op0) && null_ptr_cst_p (orig_op1)
3858 && code != EQ_EXPR && code != NE_EXPR)
3859 /* Or if one of OP0 or OP1 is neither a pointer nor NULL. */
3860 || (!null_ptr_cst_p (orig_op0) && TREE_CODE (TREE_TYPE (op0)) != POINTER_TYPE)
3861 || (!null_ptr_cst_p (orig_op1) && TREE_CODE (TREE_TYPE (op1)) != POINTER_TYPE))
3862 && (complain & tf_warning))
3863 /* Some sort of arithmetic operation involving NULL was
3864 performed. Note that pointer-difference and pointer-addition
3865 have already been handled above, and so we don't end up here in
3867 warning (OPT_Wpointer_arith, "NULL used in arithmetic");
3870 /* If CONVERTED is zero, both args will be converted to type RESULT_TYPE.
3871 Then the expression will be built.
3872 It will be given type FINAL_TYPE if that is nonzero;
3873 otherwise, it will be given type RESULT_TYPE. */
3876 if (TREE_TYPE (op0) != result_type)
3877 op0 = cp_convert_and_check (result_type, op0);
3878 if (TREE_TYPE (op1) != result_type)
3879 op1 = cp_convert_and_check (result_type, op1);
3881 if (op0 == error_mark_node || op1 == error_mark_node)
3882 return error_mark_node;
3885 if (build_type == NULL_TREE)
3886 build_type = result_type;
3888 result = build2 (resultcode, build_type, op0, op1);
3889 result = fold_if_not_in_template (result);
3890 if (final_type != 0)
3891 result = cp_convert (final_type, result);
3893 if (TREE_OVERFLOW_P (result)
3894 && !TREE_OVERFLOW_P (op0)
3895 && !TREE_OVERFLOW_P (op1))
3896 overflow_warning (result);
3901 /* Return a tree for the sum or difference (RESULTCODE says which)
3902 of pointer PTROP and integer INTOP. */
3905 cp_pointer_int_sum (enum tree_code resultcode, tree ptrop, tree intop)
3907 tree res_type = TREE_TYPE (ptrop);
3909 /* pointer_int_sum() uses size_in_bytes() on the TREE_TYPE(res_type)
3910 in certain circumstance (when it's valid to do so). So we need
3911 to make sure it's complete. We don't need to check here, if we
3912 can actually complete it at all, as those checks will be done in
3913 pointer_int_sum() anyway. */
3914 complete_type (TREE_TYPE (res_type));
3916 return pointer_int_sum (resultcode, ptrop,
3917 fold_if_not_in_template (intop));
3920 /* Return a tree for the difference of pointers OP0 and OP1.
3921 The resulting tree has type int. */
3924 pointer_diff (tree op0, tree op1, tree ptrtype)
3927 tree restype = ptrdiff_type_node;
3928 tree target_type = TREE_TYPE (ptrtype);
3930 if (!complete_type_or_else (target_type, NULL_TREE))
3931 return error_mark_node;
3933 if (TREE_CODE (target_type) == VOID_TYPE)
3934 permerror (input_location, "ISO C++ forbids using pointer of type %<void *%> in subtraction");
3935 if (TREE_CODE (target_type) == FUNCTION_TYPE)
3936 permerror (input_location, "ISO C++ forbids using pointer to a function in subtraction");
3937 if (TREE_CODE (target_type) == METHOD_TYPE)
3938 permerror (input_location, "ISO C++ forbids using pointer to a method in subtraction");
3940 /* First do the subtraction as integers;
3941 then drop through to build the divide operator. */
3943 op0 = cp_build_binary_op (MINUS_EXPR,
3944 cp_convert (restype, op0),
3945 cp_convert (restype, op1),
3946 tf_warning_or_error);
3948 /* This generates an error if op1 is a pointer to an incomplete type. */
3949 if (!COMPLETE_TYPE_P (TREE_TYPE (TREE_TYPE (op1))))
3950 error ("invalid use of a pointer to an incomplete type in pointer arithmetic");
3952 op1 = (TYPE_PTROB_P (ptrtype)
3953 ? size_in_bytes (target_type)
3954 : integer_one_node);
3956 /* Do the division. */
3958 result = build2 (EXACT_DIV_EXPR, restype, op0, cp_convert (restype, op1));
3959 return fold_if_not_in_template (result);
3962 /* Construct and perhaps optimize a tree representation
3963 for a unary operation. CODE, a tree_code, specifies the operation
3964 and XARG is the operand. */
3967 build_x_unary_op (enum tree_code code, tree xarg, tsubst_flags_t complain)
3969 tree orig_expr = xarg;
3973 if (processing_template_decl)
3975 if (type_dependent_expression_p (xarg))
3976 return build_min_nt (code, xarg, NULL_TREE);
3978 xarg = build_non_dependent_expr (xarg);
3983 /* [expr.unary.op] says:
3985 The address of an object of incomplete type can be taken.
3987 (And is just the ordinary address operator, not an overloaded
3988 "operator &".) However, if the type is a template
3989 specialization, we must complete the type at this point so that
3990 an overloaded "operator &" will be available if required. */
3991 if (code == ADDR_EXPR
3992 && TREE_CODE (xarg) != TEMPLATE_ID_EXPR
3993 && ((CLASS_TYPE_P (TREE_TYPE (xarg))
3994 && !COMPLETE_TYPE_P (complete_type (TREE_TYPE (xarg))))
3995 || (TREE_CODE (xarg) == OFFSET_REF)))
3996 /* Don't look for a function. */;
3998 exp = build_new_op (code, LOOKUP_NORMAL, xarg, NULL_TREE, NULL_TREE,
3999 /*overloaded_p=*/NULL, complain);
4000 if (!exp && code == ADDR_EXPR)
4002 /* A pointer to member-function can be formed only by saying
4004 if (!flag_ms_extensions && TREE_CODE (TREE_TYPE (xarg)) == METHOD_TYPE
4005 && (TREE_CODE (xarg) != OFFSET_REF || !PTRMEM_OK_P (xarg)))
4007 if (TREE_CODE (xarg) != OFFSET_REF
4008 || !TYPE_P (TREE_OPERAND (xarg, 0)))
4010 error ("invalid use of %qE to form a pointer-to-member-function",
4012 if (TREE_CODE (xarg) != OFFSET_REF)
4013 inform (input_location, " a qualified-id is required");
4014 return error_mark_node;
4018 error ("parentheses around %qE cannot be used to form a"
4019 " pointer-to-member-function",
4021 PTRMEM_OK_P (xarg) = 1;
4025 if (TREE_CODE (xarg) == OFFSET_REF)
4027 ptrmem = PTRMEM_OK_P (xarg);
4029 if (!ptrmem && !flag_ms_extensions
4030 && TREE_CODE (TREE_TYPE (TREE_OPERAND (xarg, 1))) == METHOD_TYPE)
4032 /* A single non-static member, make sure we don't allow a
4033 pointer-to-member. */
4034 xarg = build2 (OFFSET_REF, TREE_TYPE (xarg),
4035 TREE_OPERAND (xarg, 0),
4036 ovl_cons (TREE_OPERAND (xarg, 1), NULL_TREE));
4037 PTRMEM_OK_P (xarg) = ptrmem;
4040 else if (TREE_CODE (xarg) == TARGET_EXPR && (complain & tf_warning))
4041 warning (0, "taking address of temporary");
4042 exp = cp_build_unary_op (ADDR_EXPR, xarg, 0, complain);
4045 if (processing_template_decl && exp != error_mark_node)
4046 exp = build_min_non_dep (code, exp, orig_expr,
4047 /*For {PRE,POST}{INC,DEC}REMENT_EXPR*/NULL_TREE);
4048 if (TREE_CODE (exp) == ADDR_EXPR)
4049 PTRMEM_OK_P (exp) = ptrmem;
4053 /* Like c_common_truthvalue_conversion, but handle pointer-to-member
4054 constants, where a null value is represented by an INTEGER_CST of
4058 cp_truthvalue_conversion (tree expr)
4060 tree type = TREE_TYPE (expr);
4061 if (TYPE_PTRMEM_P (type))
4062 return build_binary_op (NE_EXPR, expr, integer_zero_node, 1);
4064 return c_common_truthvalue_conversion (expr);
4067 /* Just like cp_truthvalue_conversion, but we want a CLEANUP_POINT_EXPR. */
4070 condition_conversion (tree expr)
4073 if (processing_template_decl)
4075 t = perform_implicit_conversion (boolean_type_node, expr,
4076 tf_warning_or_error);
4077 t = fold_build_cleanup_point_expr (boolean_type_node, t);
4081 /* Return an ADDR_EXPR giving the address of T. This function
4082 attempts no optimizations or simplifications; it is a low-level
4086 build_address (tree t)
4090 if (error_operand_p (t) || !cxx_mark_addressable (t))
4091 return error_mark_node;
4093 addr = build1 (ADDR_EXPR, build_pointer_type (TREE_TYPE (t)), t);
4098 /* Return a NOP_EXPR converting EXPR to TYPE. */
4101 build_nop (tree type, tree expr)
4103 if (type == error_mark_node || error_operand_p (expr))
4105 return build1 (NOP_EXPR, type, expr);
4108 /* C++: Must handle pointers to members.
4110 Perhaps type instantiation should be extended to handle conversion
4111 from aggregates to types we don't yet know we want? (Or are those
4112 cases typically errors which should be reported?)
4114 NOCONVERT nonzero suppresses the default promotions
4115 (such as from short to int). */
4118 cp_build_unary_op (enum tree_code code, tree xarg, int noconvert,
4119 tsubst_flags_t complain)
4121 /* No default_conversion here. It causes trouble for ADDR_EXPR. */
4124 const char *errstring = NULL;
4126 const char *invalid_op_diag;
4128 if (arg == error_mark_node)
4129 return error_mark_node;
4131 if ((invalid_op_diag
4132 = targetm.invalid_unary_op ((code == UNARY_PLUS_EXPR
4137 error (invalid_op_diag);
4138 return error_mark_node;
4143 case UNARY_PLUS_EXPR:
4146 int flags = WANT_ARITH | WANT_ENUM;
4147 /* Unary plus (but not unary minus) is allowed on pointers. */
4148 if (code == UNARY_PLUS_EXPR)
4149 flags |= WANT_POINTER;
4150 arg = build_expr_type_conversion (flags, arg, true);
4152 errstring = (code == NEGATE_EXPR
4153 ? "wrong type argument to unary minus"
4154 : "wrong type argument to unary plus");
4157 if (!noconvert && CP_INTEGRAL_TYPE_P (TREE_TYPE (arg)))
4158 arg = perform_integral_promotions (arg);
4160 /* Make sure the result is not an lvalue: a unary plus or minus
4161 expression is always a rvalue. */
4168 if (TREE_CODE (TREE_TYPE (arg)) == COMPLEX_TYPE)
4172 arg = default_conversion (arg);
4174 else if (!(arg = build_expr_type_conversion (WANT_INT | WANT_ENUM
4177 errstring = "wrong type argument to bit-complement";
4178 else if (!noconvert && CP_INTEGRAL_TYPE_P (TREE_TYPE (arg)))
4179 arg = perform_integral_promotions (arg);
4183 if (!(arg = build_expr_type_conversion (WANT_ARITH | WANT_ENUM, arg, true)))
4184 errstring = "wrong type argument to abs";
4185 else if (!noconvert)
4186 arg = default_conversion (arg);
4190 /* Conjugating a real value is a no-op, but allow it anyway. */
4191 if (!(arg = build_expr_type_conversion (WANT_ARITH | WANT_ENUM, arg, true)))
4192 errstring = "wrong type argument to conjugation";
4193 else if (!noconvert)
4194 arg = default_conversion (arg);
4197 case TRUTH_NOT_EXPR:
4198 arg = perform_implicit_conversion (boolean_type_node, arg,
4200 val = invert_truthvalue (arg);
4201 if (arg != error_mark_node)
4203 errstring = "in argument to unary !";
4210 if (TREE_CODE (arg) == COMPLEX_CST)
4211 return TREE_REALPART (arg);
4212 else if (TREE_CODE (TREE_TYPE (arg)) == COMPLEX_TYPE)
4214 arg = build1 (REALPART_EXPR, TREE_TYPE (TREE_TYPE (arg)), arg);
4215 return fold_if_not_in_template (arg);
4221 if (TREE_CODE (arg) == COMPLEX_CST)
4222 return TREE_IMAGPART (arg);
4223 else if (TREE_CODE (TREE_TYPE (arg)) == COMPLEX_TYPE)
4225 arg = build1 (IMAGPART_EXPR, TREE_TYPE (TREE_TYPE (arg)), arg);
4226 return fold_if_not_in_template (arg);
4229 return cp_convert (TREE_TYPE (arg), integer_zero_node);
4231 case PREINCREMENT_EXPR:
4232 case POSTINCREMENT_EXPR:
4233 case PREDECREMENT_EXPR:
4234 case POSTDECREMENT_EXPR:
4235 /* Handle complex lvalues (when permitted)
4236 by reduction to simpler cases. */
4238 val = unary_complex_lvalue (code, arg);
4242 /* Increment or decrement the real part of the value,
4243 and don't change the imaginary part. */
4244 if (TREE_CODE (TREE_TYPE (arg)) == COMPLEX_TYPE)
4248 arg = stabilize_reference (arg);
4249 real = cp_build_unary_op (REALPART_EXPR, arg, 1, complain);
4250 imag = cp_build_unary_op (IMAGPART_EXPR, arg, 1, complain);
4251 real = cp_build_unary_op (code, real, 1, complain);
4252 if (real == error_mark_node || imag == error_mark_node)
4253 return error_mark_node;
4254 return build2 (COMPLEX_EXPR, TREE_TYPE (arg),
4258 /* Report invalid types. */
4260 if (!(arg = build_expr_type_conversion (WANT_ARITH | WANT_POINTER,
4263 if (code == PREINCREMENT_EXPR)
4264 errstring ="no pre-increment operator for type";
4265 else if (code == POSTINCREMENT_EXPR)
4266 errstring ="no post-increment operator for type";
4267 else if (code == PREDECREMENT_EXPR)
4268 errstring ="no pre-decrement operator for type";
4270 errstring ="no post-decrement operator for type";
4273 else if (arg == error_mark_node)
4274 return error_mark_node;
4276 /* Report something read-only. */
4278 if (CP_TYPE_CONST_P (TREE_TYPE (arg))
4279 || TREE_READONLY (arg))
4281 if (complain & tf_error)
4282 readonly_error (arg, ((code == PREINCREMENT_EXPR
4283 || code == POSTINCREMENT_EXPR)
4284 ? "increment" : "decrement"));
4286 return error_mark_node;
4292 tree result_type = TREE_TYPE (arg);
4294 declared_type = unlowered_expr_type (arg);
4296 arg = get_unwidened (arg, 0);
4297 argtype = TREE_TYPE (arg);
4299 /* ARM $5.2.5 last annotation says this should be forbidden. */
4300 if (TREE_CODE (argtype) == ENUMERAL_TYPE)
4302 if (complain & tf_error)
4303 permerror (input_location, (code == PREINCREMENT_EXPR || code == POSTINCREMENT_EXPR)
4304 ? G_("ISO C++ forbids incrementing an enum")
4305 : G_("ISO C++ forbids decrementing an enum"));
4307 return error_mark_node;
4310 /* Compute the increment. */
4312 if (TREE_CODE (argtype) == POINTER_TYPE)
4314 tree type = complete_type (TREE_TYPE (argtype));
4316 if (!COMPLETE_OR_VOID_TYPE_P (type))
4318 if (complain & tf_error)
4319 error (((code == PREINCREMENT_EXPR
4320 || code == POSTINCREMENT_EXPR))
4321 ? G_("cannot increment a pointer to incomplete type %qT")
4322 : G_("cannot decrement a pointer to incomplete type %qT"),
4323 TREE_TYPE (argtype));
4325 return error_mark_node;
4327 else if ((pedantic || warn_pointer_arith)
4328 && !TYPE_PTROB_P (argtype))
4330 if (complain & tf_error)
4331 permerror (input_location, (code == PREINCREMENT_EXPR
4332 || code == POSTINCREMENT_EXPR)
4333 ? G_("ISO C++ forbids incrementing a pointer of type %qT")
4334 : G_("ISO C++ forbids decrementing a pointer of type %qT"),
4337 return error_mark_node;
4340 inc = cxx_sizeof_nowarn (TREE_TYPE (argtype));
4343 inc = integer_one_node;
4345 inc = cp_convert (argtype, inc);
4347 /* Complain about anything else that is not a true lvalue. */
4348 if (!lvalue_or_else (arg, ((code == PREINCREMENT_EXPR
4349 || code == POSTINCREMENT_EXPR)
4350 ? lv_increment : lv_decrement),
4352 return error_mark_node;
4354 /* Forbid using -- on `bool'. */
4355 if (same_type_p (declared_type, boolean_type_node))
4357 if (code == POSTDECREMENT_EXPR || code == PREDECREMENT_EXPR)
4359 if (complain & tf_error)
4360 error ("invalid use of Boolean expression as operand "
4361 "to %<operator--%>");
4362 return error_mark_node;
4364 val = boolean_increment (code, arg);
4367 val = build2 (code, TREE_TYPE (arg), arg, inc);
4369 TREE_SIDE_EFFECTS (val) = 1;
4370 return cp_convert (result_type, val);
4374 /* Note that this operation never does default_conversion
4375 regardless of NOCONVERT. */
4377 argtype = lvalue_type (arg);
4379 if (TREE_CODE (arg) == OFFSET_REF)
4382 if (TREE_CODE (argtype) == REFERENCE_TYPE)
4384 tree type = build_pointer_type (TREE_TYPE (argtype));
4385 arg = build1 (CONVERT_EXPR, type, arg);
4388 else if (DECL_MAIN_P (arg))
4391 if (complain & tf_error)
4392 permerror (input_location, "ISO C++ forbids taking address of function %<::main%>");
4394 return error_mark_node;
4397 /* Let &* cancel out to simplify resulting code. */
4398 if (TREE_CODE (arg) == INDIRECT_REF)
4400 /* We don't need to have `current_class_ptr' wrapped in a
4401 NON_LVALUE_EXPR node. */
4402 if (arg == current_class_ref)
4403 return current_class_ptr;
4405 arg = TREE_OPERAND (arg, 0);
4406 if (TREE_CODE (TREE_TYPE (arg)) == REFERENCE_TYPE)
4408 tree type = build_pointer_type (TREE_TYPE (TREE_TYPE (arg)));
4409 arg = build1 (CONVERT_EXPR, type, arg);
4412 /* Don't let this be an lvalue. */
4417 /* Uninstantiated types are all functions. Taking the
4418 address of a function is a no-op, so just return the
4421 gcc_assert (TREE_CODE (arg) != IDENTIFIER_NODE
4422 || !IDENTIFIER_OPNAME_P (arg));
4424 if (TREE_CODE (arg) == COMPONENT_REF && type_unknown_p (arg)
4425 && !really_overloaded_fn (TREE_OPERAND (arg, 1)))
4427 /* They're trying to take the address of a unique non-static
4428 member function. This is ill-formed (except in MS-land),
4429 but let's try to DTRT.
4430 Note: We only handle unique functions here because we don't
4431 want to complain if there's a static overload; non-unique
4432 cases will be handled by instantiate_type. But we need to
4433 handle this case here to allow casts on the resulting PMF.
4434 We could defer this in non-MS mode, but it's easier to give
4435 a useful error here. */
4437 /* Inside constant member functions, the `this' pointer
4438 contains an extra const qualifier. TYPE_MAIN_VARIANT
4439 is used here to remove this const from the diagnostics
4440 and the created OFFSET_REF. */
4441 tree base = TYPE_MAIN_VARIANT (TREE_TYPE (TREE_OPERAND (arg, 0)));
4442 tree fn = get_first_fn (TREE_OPERAND (arg, 1));
4445 if (! flag_ms_extensions)
4447 tree name = DECL_NAME (fn);
4448 if (!(complain & tf_error))
4449 return error_mark_node;
4450 else if (current_class_type
4451 && TREE_OPERAND (arg, 0) == current_class_ref)
4452 /* An expression like &memfn. */
4453 permerror (input_location, "ISO C++ forbids taking the address of an unqualified"
4454 " or parenthesized non-static member function to form"
4455 " a pointer to member function. Say %<&%T::%D%>",
4458 permerror (input_location, "ISO C++ forbids taking the address of a bound member"
4459 " function to form a pointer to member function."
4463 arg = build_offset_ref (base, fn, /*address_p=*/true);
4467 if (type_unknown_p (arg))
4468 return build1 (ADDR_EXPR, unknown_type_node, arg);
4470 /* Handle complex lvalues (when permitted)
4471 by reduction to simpler cases. */
4472 val = unary_complex_lvalue (code, arg);
4476 switch (TREE_CODE (arg))
4480 case FIX_TRUNC_EXPR:
4481 /* Even if we're not being pedantic, we cannot allow this
4482 extension when we're instantiating in a SFINAE
4484 if (! lvalue_p (arg) && complain == tf_none)
4486 if (complain & tf_error)
4487 permerror (input_location, "ISO C++ forbids taking the address of a cast to a non-lvalue expression");
4489 return error_mark_node;
4494 arg = BASELINK_FUNCTIONS (arg);
4498 arg = OVL_CURRENT (arg);
4502 /* Turn a reference to a non-static data member into a
4503 pointer-to-member. */
4508 if (!PTRMEM_OK_P (arg))
4509 return cp_build_unary_op (code, arg, 0, complain);
4511 t = TREE_OPERAND (arg, 1);
4512 if (TREE_CODE (TREE_TYPE (t)) == REFERENCE_TYPE)
4514 if (complain & tf_error)
4515 error ("cannot create pointer to reference member %qD", t);
4516 return error_mark_node;
4519 type = build_ptrmem_type (context_for_name_lookup (t),
4521 t = make_ptrmem_cst (type, TREE_OPERAND (arg, 1));
4529 /* Anything not already handled and not a true memory reference
4531 if (TREE_CODE (argtype) != FUNCTION_TYPE
4532 && TREE_CODE (argtype) != METHOD_TYPE
4533 && TREE_CODE (arg) != OFFSET_REF
4534 && !lvalue_or_else (arg, lv_addressof, complain))
4535 return error_mark_node;
4537 if (argtype != error_mark_node)
4538 argtype = build_pointer_type (argtype);
4540 /* In a template, we are processing a non-dependent expression
4541 so we can just form an ADDR_EXPR with the correct type. */
4542 if (processing_template_decl || TREE_CODE (arg) != COMPONENT_REF)
4544 val = build_address (arg);
4545 if (TREE_CODE (arg) == OFFSET_REF)
4546 PTRMEM_OK_P (val) = PTRMEM_OK_P (arg);
4548 else if (TREE_CODE (TREE_OPERAND (arg, 1)) == BASELINK)
4550 tree fn = BASELINK_FUNCTIONS (TREE_OPERAND (arg, 1));
4552 /* We can only get here with a single static member
4554 gcc_assert (TREE_CODE (fn) == FUNCTION_DECL
4555 && DECL_STATIC_FUNCTION_P (fn));
4557 val = build_address (fn);
4558 if (TREE_SIDE_EFFECTS (TREE_OPERAND (arg, 0)))
4559 /* Do not lose object's side effects. */
4560 val = build2 (COMPOUND_EXPR, TREE_TYPE (val),
4561 TREE_OPERAND (arg, 0), val);
4563 else if (DECL_C_BIT_FIELD (TREE_OPERAND (arg, 1)))
4565 if (complain & tf_error)
4566 error ("attempt to take address of bit-field structure member %qD",
4567 TREE_OPERAND (arg, 1));
4568 return error_mark_node;
4572 tree object = TREE_OPERAND (arg, 0);
4573 tree field = TREE_OPERAND (arg, 1);
4574 gcc_assert (same_type_ignoring_top_level_qualifiers_p
4575 (TREE_TYPE (object), decl_type_context (field)));
4576 val = build_address (arg);
4579 if (TREE_CODE (argtype) == POINTER_TYPE
4580 && TREE_CODE (TREE_TYPE (argtype)) == METHOD_TYPE)
4582 build_ptrmemfunc_type (argtype);
4583 val = build_ptrmemfunc (argtype, val, 0,
4584 /*c_cast_p=*/false);
4596 argtype = TREE_TYPE (arg);
4597 return fold_if_not_in_template (build1 (code, argtype, arg));
4600 if (complain & tf_error)
4601 error ("%s", errstring);
4602 return error_mark_node;
4605 /* Hook for the c-common bits that build a unary op. */
4607 build_unary_op (enum tree_code code, tree xarg, int noconvert)
4609 return cp_build_unary_op (code, xarg, noconvert, tf_warning_or_error);
4612 /* Apply unary lvalue-demanding operator CODE to the expression ARG
4613 for certain kinds of expressions which are not really lvalues
4614 but which we can accept as lvalues.
4616 If ARG is not a kind of expression we can handle, return
4620 unary_complex_lvalue (enum tree_code code, tree arg)
4622 /* Inside a template, making these kinds of adjustments is
4623 pointless; we are only concerned with the type of the
4625 if (processing_template_decl)
4628 /* Handle (a, b) used as an "lvalue". */
4629 if (TREE_CODE (arg) == COMPOUND_EXPR)
4631 tree real_result = cp_build_unary_op (code, TREE_OPERAND (arg, 1), 0,
4632 tf_warning_or_error);
4633 return build2 (COMPOUND_EXPR, TREE_TYPE (real_result),
4634 TREE_OPERAND (arg, 0), real_result);
4637 /* Handle (a ? b : c) used as an "lvalue". */
4638 if (TREE_CODE (arg) == COND_EXPR
4639 || TREE_CODE (arg) == MIN_EXPR || TREE_CODE (arg) == MAX_EXPR)
4640 return rationalize_conditional_expr (code, arg, tf_warning_or_error);
4642 /* Handle (a = b), (++a), and (--a) used as an "lvalue". */
4643 if (TREE_CODE (arg) == MODIFY_EXPR
4644 || TREE_CODE (arg) == PREINCREMENT_EXPR
4645 || TREE_CODE (arg) == PREDECREMENT_EXPR)
4647 tree lvalue = TREE_OPERAND (arg, 0);
4648 if (TREE_SIDE_EFFECTS (lvalue))
4650 lvalue = stabilize_reference (lvalue);
4651 arg = build2 (TREE_CODE (arg), TREE_TYPE (arg),
4652 lvalue, TREE_OPERAND (arg, 1));
4654 return unary_complex_lvalue
4655 (code, build2 (COMPOUND_EXPR, TREE_TYPE (lvalue), arg, lvalue));
4658 if (code != ADDR_EXPR)
4661 /* Handle (a = b) used as an "lvalue" for `&'. */
4662 if (TREE_CODE (arg) == MODIFY_EXPR
4663 || TREE_CODE (arg) == INIT_EXPR)
4665 tree real_result = cp_build_unary_op (code, TREE_OPERAND (arg, 0), 0,
4666 tf_warning_or_error);
4667 arg = build2 (COMPOUND_EXPR, TREE_TYPE (real_result),
4669 TREE_NO_WARNING (arg) = 1;
4673 if (TREE_CODE (TREE_TYPE (arg)) == FUNCTION_TYPE
4674 || TREE_CODE (TREE_TYPE (arg)) == METHOD_TYPE
4675 || TREE_CODE (arg) == OFFSET_REF)
4678 /* We permit compiler to make function calls returning
4679 objects of aggregate type look like lvalues. */
4683 if (TREE_CODE (targ) == SAVE_EXPR)
4684 targ = TREE_OPERAND (targ, 0);
4686 if (TREE_CODE (targ) == CALL_EXPR && MAYBE_CLASS_TYPE_P (TREE_TYPE (targ)))
4688 if (TREE_CODE (arg) == SAVE_EXPR)
4691 targ = build_cplus_new (TREE_TYPE (arg), arg);
4692 return build1 (ADDR_EXPR, build_pointer_type (TREE_TYPE (arg)), targ);
4695 if (TREE_CODE (arg) == SAVE_EXPR && TREE_CODE (targ) == INDIRECT_REF)
4696 return build3 (SAVE_EXPR, build_pointer_type (TREE_TYPE (arg)),
4697 TREE_OPERAND (targ, 0), current_function_decl, NULL);
4700 /* Don't let anything else be handled specially. */
4704 /* Mark EXP saying that we need to be able to take the
4705 address of it; it should not be allocated in a register.
4706 Value is true if successful.
4708 C++: we do not allow `current_class_ptr' to be addressable. */
4711 cxx_mark_addressable (tree exp)
4716 switch (TREE_CODE (x))
4723 x = TREE_OPERAND (x, 0);
4727 if (x == current_class_ptr)
4729 error ("cannot take the address of %<this%>, which is an rvalue expression");
4730 TREE_ADDRESSABLE (x) = 1; /* so compiler doesn't die later. */
4736 /* Caller should not be trying to mark initialized
4737 constant fields addressable. */
4738 gcc_assert (DECL_LANG_SPECIFIC (x) == 0
4739 || DECL_IN_AGGR_P (x) == 0
4741 || DECL_EXTERNAL (x));
4746 if (DECL_REGISTER (x) && !TREE_ADDRESSABLE (x)
4747 && !DECL_ARTIFICIAL (x))
4749 if (TREE_CODE (x) == VAR_DECL && DECL_HARD_REGISTER (x))
4752 ("address of explicit register variable %qD requested", x);
4755 else if (extra_warnings)
4757 (OPT_Wextra, "address requested for %qD, which is declared %<register%>", x);
4759 TREE_ADDRESSABLE (x) = 1;
4763 TREE_ADDRESSABLE (x) = 1;
4767 TREE_ADDRESSABLE (x) = 1;
4771 TREE_ADDRESSABLE (x) = 1;
4772 cxx_mark_addressable (TREE_OPERAND (x, 0));
4780 /* Build and return a conditional expression IFEXP ? OP1 : OP2. */
4783 build_x_conditional_expr (tree ifexp, tree op1, tree op2,
4784 tsubst_flags_t complain)
4786 tree orig_ifexp = ifexp;
4787 tree orig_op1 = op1;
4788 tree orig_op2 = op2;
4791 if (processing_template_decl)
4793 /* The standard says that the expression is type-dependent if
4794 IFEXP is type-dependent, even though the eventual type of the
4795 expression doesn't dependent on IFEXP. */
4796 if (type_dependent_expression_p (ifexp)
4797 /* As a GNU extension, the middle operand may be omitted. */
4798 || (op1 && type_dependent_expression_p (op1))
4799 || type_dependent_expression_p (op2))
4800 return build_min_nt (COND_EXPR, ifexp, op1, op2);
4801 ifexp = build_non_dependent_expr (ifexp);
4803 op1 = build_non_dependent_expr (op1);
4804 op2 = build_non_dependent_expr (op2);
4807 expr = build_conditional_expr (ifexp, op1, op2, complain);
4808 if (processing_template_decl && expr != error_mark_node)
4809 return build_min_non_dep (COND_EXPR, expr,
4810 orig_ifexp, orig_op1, orig_op2);
4814 /* Given a list of expressions, return a compound expression
4815 that performs them all and returns the value of the last of them. */
4817 tree build_x_compound_expr_from_list (tree list, const char *msg)
4819 tree expr = TREE_VALUE (list);
4821 if (TREE_CHAIN (list))
4824 permerror (input_location, "%s expression list treated as compound expression", msg);
4826 for (list = TREE_CHAIN (list); list; list = TREE_CHAIN (list))
4827 expr = build_x_compound_expr (expr, TREE_VALUE (list),
4828 tf_warning_or_error);
4834 /* Handle overloading of the ',' operator when needed. */
4837 build_x_compound_expr (tree op1, tree op2, tsubst_flags_t complain)
4840 tree orig_op1 = op1;
4841 tree orig_op2 = op2;
4843 if (processing_template_decl)
4845 if (type_dependent_expression_p (op1)
4846 || type_dependent_expression_p (op2))
4847 return build_min_nt (COMPOUND_EXPR, op1, op2);
4848 op1 = build_non_dependent_expr (op1);
4849 op2 = build_non_dependent_expr (op2);
4852 result = build_new_op (COMPOUND_EXPR, LOOKUP_NORMAL, op1, op2, NULL_TREE,
4853 /*overloaded_p=*/NULL, complain);
4855 result = cp_build_compound_expr (op1, op2, complain);
4857 if (processing_template_decl && result != error_mark_node)
4858 return build_min_non_dep (COMPOUND_EXPR, result, orig_op1, orig_op2);
4863 /* Like cp_build_compound_expr, but for the c-common bits. */
4866 build_compound_expr (tree lhs, tree rhs)
4868 return cp_build_compound_expr (lhs, rhs, tf_warning_or_error);
4871 /* Build a compound expression. */
4874 cp_build_compound_expr (tree lhs, tree rhs, tsubst_flags_t complain)
4876 lhs = convert_to_void (lhs, "left-hand operand of comma", complain);
4878 if (lhs == error_mark_node || rhs == error_mark_node)
4879 return error_mark_node;
4881 if (TREE_CODE (rhs) == TARGET_EXPR)
4883 /* If the rhs is a TARGET_EXPR, then build the compound
4884 expression inside the target_expr's initializer. This
4885 helps the compiler to eliminate unnecessary temporaries. */
4886 tree init = TREE_OPERAND (rhs, 1);
4888 init = build2 (COMPOUND_EXPR, TREE_TYPE (init), lhs, init);
4889 TREE_OPERAND (rhs, 1) = init;
4894 return build2 (COMPOUND_EXPR, TREE_TYPE (rhs), lhs, rhs);
4897 /* Issue a diagnostic message if casting from SRC_TYPE to DEST_TYPE
4898 casts away constness. CAST gives the type of cast. */
4901 check_for_casting_away_constness (tree src_type, tree dest_type,
4902 enum tree_code cast)
4904 /* C-style casts are allowed to cast away constness. With
4905 WARN_CAST_QUAL, we still want to issue a warning. */
4906 if (cast == CAST_EXPR && !warn_cast_qual)
4909 if (casts_away_constness (src_type, dest_type))
4913 warning (OPT_Wcast_qual,
4914 "cast from type %qT to type %qT casts away constness",
4915 src_type, dest_type);
4918 case STATIC_CAST_EXPR:
4919 error ("static_cast from type %qT to type %qT casts away constness",
4920 src_type, dest_type);
4923 case REINTERPRET_CAST_EXPR:
4924 error ("reinterpret_cast from type %qT to type %qT casts away constness",
4925 src_type, dest_type);
4932 /* Convert EXPR (an expression with pointer-to-member type) to TYPE
4933 (another pointer-to-member type in the same hierarchy) and return
4934 the converted expression. If ALLOW_INVERSE_P is permitted, a
4935 pointer-to-derived may be converted to pointer-to-base; otherwise,
4936 only the other direction is permitted. If C_CAST_P is true, this
4937 conversion is taking place as part of a C-style cast. */
4940 convert_ptrmem (tree type, tree expr, bool allow_inverse_p,
4943 if (TYPE_PTRMEM_P (type))
4947 if (TREE_CODE (expr) == PTRMEM_CST)
4948 expr = cplus_expand_constant (expr);
4949 delta = get_delta_difference (TYPE_PTRMEM_CLASS_TYPE (TREE_TYPE (expr)),
4950 TYPE_PTRMEM_CLASS_TYPE (type),
4953 if (!integer_zerop (delta))
4955 tree cond, op1, op2;
4957 cond = cp_build_binary_op (EQ_EXPR,
4959 build_int_cst (TREE_TYPE (expr), -1),
4960 tf_warning_or_error);
4961 op1 = build_nop (ptrdiff_type_node, expr);
4962 op2 = cp_build_binary_op (PLUS_EXPR, op1, delta,
4963 tf_warning_or_error);
4965 expr = fold_build3 (COND_EXPR, ptrdiff_type_node, cond, op1, op2);
4969 return build_nop (type, expr);
4972 return build_ptrmemfunc (TYPE_PTRMEMFUNC_FN_TYPE (type), expr,
4973 allow_inverse_p, c_cast_p);
4976 /* If EXPR is an INTEGER_CST and ORIG is an arithmetic constant, return
4977 a version of EXPR that has TREE_OVERFLOW set if it is set in ORIG.
4978 Otherwise, return EXPR unchanged. */
4981 ignore_overflows (tree expr, tree orig)
4983 if (TREE_CODE (expr) == INTEGER_CST
4984 && CONSTANT_CLASS_P (orig)
4985 && TREE_CODE (orig) != STRING_CST
4986 && TREE_OVERFLOW (expr) != TREE_OVERFLOW (orig))
4988 if (!TREE_OVERFLOW (orig))
4989 /* Ensure constant sharing. */
4990 expr = build_int_cst_wide (TREE_TYPE (expr),
4991 TREE_INT_CST_LOW (expr),
4992 TREE_INT_CST_HIGH (expr));
4995 /* Avoid clobbering a shared constant. */
4996 expr = copy_node (expr);
4997 TREE_OVERFLOW (expr) = TREE_OVERFLOW (orig);
5003 /* Perform a static_cast from EXPR to TYPE. When C_CAST_P is true,
5004 this static_cast is being attempted as one of the possible casts
5005 allowed by a C-style cast. (In that case, accessibility of base
5006 classes is not considered, and it is OK to cast away
5007 constness.) Return the result of the cast. *VALID_P is set to
5008 indicate whether or not the cast was valid. */
5011 build_static_cast_1 (tree type, tree expr, bool c_cast_p,
5012 bool *valid_p, tsubst_flags_t complain)
5018 /* Assume the cast is valid. */
5021 intype = TREE_TYPE (expr);
5023 /* Save casted types in the function's used types hash table. */
5024 used_types_insert (type);
5026 /* [expr.static.cast]
5028 An lvalue of type "cv1 B", where B is a class type, can be cast
5029 to type "reference to cv2 D", where D is a class derived (clause
5030 _class.derived_) from B, if a valid standard conversion from
5031 "pointer to D" to "pointer to B" exists (_conv.ptr_), cv2 is the
5032 same cv-qualification as, or greater cv-qualification than, cv1,
5033 and B is not a virtual base class of D. */
5034 /* We check this case before checking the validity of "TYPE t =
5035 EXPR;" below because for this case:
5038 struct D : public B { D(const B&); };
5040 void f() { static_cast<const D&>(b); }
5042 we want to avoid constructing a new D. The standard is not
5043 completely clear about this issue, but our interpretation is
5044 consistent with other compilers. */
5045 if (TREE_CODE (type) == REFERENCE_TYPE
5046 && CLASS_TYPE_P (TREE_TYPE (type))
5047 && CLASS_TYPE_P (intype)
5048 && real_lvalue_p (expr)
5049 && DERIVED_FROM_P (intype, TREE_TYPE (type))
5050 && can_convert (build_pointer_type (TYPE_MAIN_VARIANT (intype)),
5051 build_pointer_type (TYPE_MAIN_VARIANT
5052 (TREE_TYPE (type))))
5054 || at_least_as_qualified_p (TREE_TYPE (type), intype)))
5058 /* There is a standard conversion from "D*" to "B*" even if "B"
5059 is ambiguous or inaccessible. If this is really a
5060 static_cast, then we check both for inaccessibility and
5061 ambiguity. However, if this is a static_cast being performed
5062 because the user wrote a C-style cast, then accessibility is
5064 base = lookup_base (TREE_TYPE (type), intype,
5065 c_cast_p ? ba_unique : ba_check,
5068 /* Convert from "B*" to "D*". This function will check that "B"
5069 is not a virtual base of "D". */
5070 expr = build_base_path (MINUS_EXPR, build_address (expr),
5071 base, /*nonnull=*/false);
5072 /* Convert the pointer to a reference -- but then remember that
5073 there are no expressions with reference type in C++. */
5074 return convert_from_reference (build_nop (type, expr));
5079 /* [expr.static.cast]
5081 An expression e can be explicitly converted to a type T using a
5082 static_cast of the form static_cast<T>(e) if the declaration T
5083 t(e);" is well-formed, for some invented temporary variable
5085 result = perform_direct_initialization_if_possible (type, expr,
5086 c_cast_p, complain);
5089 result = convert_from_reference (result);
5091 /* Ignore any integer overflow caused by the cast. */
5092 result = ignore_overflows (result, orig);
5094 /* [expr.static.cast]
5096 If T is a reference type, the result is an lvalue; otherwise,
5097 the result is an rvalue. */
5098 if (TREE_CODE (type) != REFERENCE_TYPE)
5099 result = rvalue (result);
5103 /* [expr.static.cast]
5105 Any expression can be explicitly converted to type cv void. */
5106 if (TREE_CODE (type) == VOID_TYPE)
5107 return convert_to_void (expr, /*implicit=*/NULL, complain);
5109 /* [expr.static.cast]
5111 The inverse of any standard conversion sequence (clause _conv_),
5112 other than the lvalue-to-rvalue (_conv.lval_), array-to-pointer
5113 (_conv.array_), function-to-pointer (_conv.func_), and boolean
5114 (_conv.bool_) conversions, can be performed explicitly using
5115 static_cast subject to the restriction that the explicit
5116 conversion does not cast away constness (_expr.const.cast_), and
5117 the following additional rules for specific cases: */
5118 /* For reference, the conversions not excluded are: integral
5119 promotions, floating point promotion, integral conversions,
5120 floating point conversions, floating-integral conversions,
5121 pointer conversions, and pointer to member conversions. */
5124 A value of integral _or enumeration_ type can be explicitly
5125 converted to an enumeration type. */
5126 /* The effect of all that is that any conversion between any two
5127 types which are integral, floating, or enumeration types can be
5129 if ((INTEGRAL_TYPE_P (type) || SCALAR_FLOAT_TYPE_P (type))
5130 && (INTEGRAL_TYPE_P (intype) || SCALAR_FLOAT_TYPE_P (intype)))
5132 expr = ocp_convert (type, expr, CONV_C_CAST, LOOKUP_NORMAL);
5134 /* Ignore any integer overflow caused by the cast. */
5135 expr = ignore_overflows (expr, orig);
5139 if (TYPE_PTR_P (type) && TYPE_PTR_P (intype)
5140 && CLASS_TYPE_P (TREE_TYPE (type))
5141 && CLASS_TYPE_P (TREE_TYPE (intype))
5142 && can_convert (build_pointer_type (TYPE_MAIN_VARIANT
5143 (TREE_TYPE (intype))),
5144 build_pointer_type (TYPE_MAIN_VARIANT
5145 (TREE_TYPE (type)))))
5150 check_for_casting_away_constness (intype, type, STATIC_CAST_EXPR);
5151 base = lookup_base (TREE_TYPE (type), TREE_TYPE (intype),
5152 c_cast_p ? ba_unique : ba_check,
5154 return build_base_path (MINUS_EXPR, expr, base, /*nonnull=*/false);
5157 if ((TYPE_PTRMEM_P (type) && TYPE_PTRMEM_P (intype))
5158 || (TYPE_PTRMEMFUNC_P (type) && TYPE_PTRMEMFUNC_P (intype)))
5165 c1 = TYPE_PTRMEM_CLASS_TYPE (intype);
5166 c2 = TYPE_PTRMEM_CLASS_TYPE (type);
5168 if (TYPE_PTRMEM_P (type))
5170 t1 = (build_ptrmem_type
5172 TYPE_MAIN_VARIANT (TYPE_PTRMEM_POINTED_TO_TYPE (intype))));
5173 t2 = (build_ptrmem_type
5175 TYPE_MAIN_VARIANT (TYPE_PTRMEM_POINTED_TO_TYPE (type))));
5182 if (can_convert (t1, t2) || can_convert (t2, t1))
5185 check_for_casting_away_constness (intype, type, STATIC_CAST_EXPR);
5186 return convert_ptrmem (type, expr, /*allow_inverse_p=*/1,
5191 /* [expr.static.cast]
5193 An rvalue of type "pointer to cv void" can be explicitly
5194 converted to a pointer to object type. A value of type pointer
5195 to object converted to "pointer to cv void" and back to the
5196 original pointer type will have its original value. */
5197 if (TREE_CODE (intype) == POINTER_TYPE
5198 && VOID_TYPE_P (TREE_TYPE (intype))
5199 && TYPE_PTROB_P (type))
5202 check_for_casting_away_constness (intype, type, STATIC_CAST_EXPR);
5203 return build_nop (type, expr);
5207 return error_mark_node;
5210 /* Return an expression representing static_cast<TYPE>(EXPR). */
5213 build_static_cast (tree type, tree expr, tsubst_flags_t complain)
5218 if (type == error_mark_node || expr == error_mark_node)
5219 return error_mark_node;
5221 if (processing_template_decl)
5223 expr = build_min (STATIC_CAST_EXPR, type, expr);
5224 /* We don't know if it will or will not have side effects. */
5225 TREE_SIDE_EFFECTS (expr) = 1;
5226 return convert_from_reference (expr);
5229 /* build_c_cast puts on a NOP_EXPR to make the result not an lvalue.
5230 Strip such NOP_EXPRs if VALUE is being used in non-lvalue context. */
5231 if (TREE_CODE (type) != REFERENCE_TYPE
5232 && TREE_CODE (expr) == NOP_EXPR
5233 && TREE_TYPE (expr) == TREE_TYPE (TREE_OPERAND (expr, 0)))
5234 expr = TREE_OPERAND (expr, 0);
5236 result = build_static_cast_1 (type, expr, /*c_cast_p=*/false, &valid_p,
5241 if (complain & tf_error)
5242 error ("invalid static_cast from type %qT to type %qT",
5243 TREE_TYPE (expr), type);
5244 return error_mark_node;
5247 /* EXPR is an expression with member function or pointer-to-member
5248 function type. TYPE is a pointer type. Converting EXPR to TYPE is
5249 not permitted by ISO C++, but we accept it in some modes. If we
5250 are not in one of those modes, issue a diagnostic. Return the
5251 converted expression. */
5254 convert_member_func_to_ptr (tree type, tree expr)
5259 intype = TREE_TYPE (expr);
5260 gcc_assert (TYPE_PTRMEMFUNC_P (intype)
5261 || TREE_CODE (intype) == METHOD_TYPE);
5263 if (pedantic || warn_pmf2ptr)
5264 pedwarn (input_location, pedantic ? OPT_pedantic : OPT_Wpmf_conversions,
5265 "converting from %qT to %qT", intype, type);
5267 if (TREE_CODE (intype) == METHOD_TYPE)
5268 expr = build_addr_func (expr);
5269 else if (TREE_CODE (expr) == PTRMEM_CST)
5270 expr = build_address (PTRMEM_CST_MEMBER (expr));
5273 decl = maybe_dummy_object (TYPE_PTRMEM_CLASS_TYPE (intype), 0);
5274 decl = build_address (decl);
5275 expr = get_member_function_from_ptrfunc (&decl, expr);
5278 return build_nop (type, expr);
5281 /* Return a representation for a reinterpret_cast from EXPR to TYPE.
5282 If C_CAST_P is true, this reinterpret cast is being done as part of
5283 a C-style cast. If VALID_P is non-NULL, *VALID_P is set to
5284 indicate whether or not reinterpret_cast was valid. */
5287 build_reinterpret_cast_1 (tree type, tree expr, bool c_cast_p,
5288 bool *valid_p, tsubst_flags_t complain)
5292 /* Assume the cast is invalid. */
5296 if (type == error_mark_node || error_operand_p (expr))
5297 return error_mark_node;
5299 intype = TREE_TYPE (expr);
5301 /* Save casted types in the function's used types hash table. */
5302 used_types_insert (type);
5304 /* [expr.reinterpret.cast]
5305 An lvalue expression of type T1 can be cast to the type
5306 "reference to T2" if an expression of type "pointer to T1" can be
5307 explicitly converted to the type "pointer to T2" using a
5308 reinterpret_cast. */
5309 if (TREE_CODE (type) == REFERENCE_TYPE)
5311 if (! real_lvalue_p (expr))
5313 if (complain & tf_error)
5314 error ("invalid cast of an rvalue expression of type "
5317 return error_mark_node;
5320 /* Warn about a reinterpret_cast from "A*" to "B&" if "A" and
5321 "B" are related class types; the reinterpret_cast does not
5322 adjust the pointer. */
5323 if (TYPE_PTR_P (intype)
5324 && (complain & tf_warning)
5325 && (comptypes (TREE_TYPE (intype), TREE_TYPE (type),
5326 COMPARE_BASE | COMPARE_DERIVED)))
5327 warning (0, "casting %qT to %qT does not dereference pointer",
5330 expr = cp_build_unary_op (ADDR_EXPR, expr, 0, complain);
5331 if (expr != error_mark_node)
5332 expr = build_reinterpret_cast_1
5333 (build_pointer_type (TREE_TYPE (type)), expr, c_cast_p,
5335 if (expr != error_mark_node)
5336 expr = cp_build_indirect_ref (expr, 0, complain);
5340 /* As a G++ extension, we consider conversions from member
5341 functions, and pointers to member functions to
5342 pointer-to-function and pointer-to-void types. If
5343 -Wno-pmf-conversions has not been specified,
5344 convert_member_func_to_ptr will issue an error message. */
5345 if ((TYPE_PTRMEMFUNC_P (intype)
5346 || TREE_CODE (intype) == METHOD_TYPE)
5347 && TYPE_PTR_P (type)
5348 && (TREE_CODE (TREE_TYPE (type)) == FUNCTION_TYPE
5349 || VOID_TYPE_P (TREE_TYPE (type))))
5350 return convert_member_func_to_ptr (type, expr);
5352 /* If the cast is not to a reference type, the lvalue-to-rvalue,
5353 array-to-pointer, and function-to-pointer conversions are
5355 expr = decay_conversion (expr);
5357 /* build_c_cast puts on a NOP_EXPR to make the result not an lvalue.
5358 Strip such NOP_EXPRs if VALUE is being used in non-lvalue context. */
5359 if (TREE_CODE (expr) == NOP_EXPR
5360 && TREE_TYPE (expr) == TREE_TYPE (TREE_OPERAND (expr, 0)))
5361 expr = TREE_OPERAND (expr, 0);
5363 if (error_operand_p (expr))
5364 return error_mark_node;
5366 intype = TREE_TYPE (expr);
5368 /* [expr.reinterpret.cast]
5369 A pointer can be converted to any integral type large enough to
5371 if (CP_INTEGRAL_TYPE_P (type) && TYPE_PTR_P (intype))
5373 if (TYPE_PRECISION (type) < TYPE_PRECISION (intype))
5375 if (complain & tf_error)
5376 permerror (input_location, "cast from %qT to %qT loses precision",
5379 return error_mark_node;
5382 /* [expr.reinterpret.cast]
5383 A value of integral or enumeration type can be explicitly
5384 converted to a pointer. */
5385 else if (TYPE_PTR_P (type) && INTEGRAL_OR_ENUMERATION_TYPE_P (intype))
5388 else if ((TYPE_PTRFN_P (type) && TYPE_PTRFN_P (intype))
5389 || (TYPE_PTRMEMFUNC_P (type) && TYPE_PTRMEMFUNC_P (intype)))
5390 return fold_if_not_in_template (build_nop (type, expr));
5391 else if ((TYPE_PTRMEM_P (type) && TYPE_PTRMEM_P (intype))
5392 || (TYPE_PTROBV_P (type) && TYPE_PTROBV_P (intype)))
5397 check_for_casting_away_constness (intype, type, REINTERPRET_CAST_EXPR);
5398 /* Warn about possible alignment problems. */
5399 if (STRICT_ALIGNMENT && warn_cast_align
5400 && (complain & tf_warning)
5401 && !VOID_TYPE_P (type)
5402 && TREE_CODE (TREE_TYPE (intype)) != FUNCTION_TYPE
5403 && COMPLETE_TYPE_P (TREE_TYPE (type))
5404 && COMPLETE_TYPE_P (TREE_TYPE (intype))
5405 && TYPE_ALIGN (TREE_TYPE (type)) > TYPE_ALIGN (TREE_TYPE (intype)))
5406 warning (OPT_Wcast_align, "cast from %qT to %qT "
5407 "increases required alignment of target type", intype, type);
5409 /* We need to strip nops here, because the front end likes to
5410 create (int *)&a for array-to-pointer decay, instead of &a[0]. */
5412 if (warn_strict_aliasing <= 2)
5413 strict_aliasing_warning (intype, type, sexpr);
5415 return fold_if_not_in_template (build_nop (type, expr));
5417 else if ((TYPE_PTRFN_P (type) && TYPE_PTROBV_P (intype))
5418 || (TYPE_PTRFN_P (intype) && TYPE_PTROBV_P (type)))
5420 if (pedantic && (complain & tf_warning))
5421 /* Only issue a warning, as we have always supported this
5422 where possible, and it is necessary in some cases. DR 195
5423 addresses this issue, but as of 2004/10/26 is still in
5425 warning (0, "ISO C++ forbids casting between pointer-to-function and pointer-to-object");
5426 return fold_if_not_in_template (build_nop (type, expr));
5428 else if (TREE_CODE (type) == VECTOR_TYPE)
5429 return fold_if_not_in_template (convert_to_vector (type, expr));
5430 else if (TREE_CODE (intype) == VECTOR_TYPE && INTEGRAL_TYPE_P (type))
5431 return fold_if_not_in_template (convert_to_integer (type, expr));
5436 if (complain & tf_error)
5437 error ("invalid cast from type %qT to type %qT", intype, type);
5438 return error_mark_node;
5441 return cp_convert (type, expr);
5445 build_reinterpret_cast (tree type, tree expr, tsubst_flags_t complain)
5447 if (type == error_mark_node || expr == error_mark_node)
5448 return error_mark_node;
5450 if (processing_template_decl)
5452 tree t = build_min (REINTERPRET_CAST_EXPR, type, expr);
5454 if (!TREE_SIDE_EFFECTS (t)
5455 && type_dependent_expression_p (expr))
5456 /* There might turn out to be side effects inside expr. */
5457 TREE_SIDE_EFFECTS (t) = 1;
5458 return convert_from_reference (t);
5461 return build_reinterpret_cast_1 (type, expr, /*c_cast_p=*/false,
5462 /*valid_p=*/NULL, complain);
5465 /* Perform a const_cast from EXPR to TYPE. If the cast is valid,
5466 return an appropriate expression. Otherwise, return
5467 error_mark_node. If the cast is not valid, and COMPLAIN is true,
5468 then a diagnostic will be issued. If VALID_P is non-NULL, we are
5469 performing a C-style cast, its value upon return will indicate
5470 whether or not the conversion succeeded. */
5473 build_const_cast_1 (tree dst_type, tree expr, bool complain,
5477 tree reference_type;
5479 /* Callers are responsible for handling error_mark_node as a
5480 destination type. */
5481 gcc_assert (dst_type != error_mark_node);
5482 /* In a template, callers should be building syntactic
5483 representations of casts, not using this machinery. */
5484 gcc_assert (!processing_template_decl);
5486 /* Assume the conversion is invalid. */
5490 if (!POINTER_TYPE_P (dst_type) && !TYPE_PTRMEM_P (dst_type))
5493 error ("invalid use of const_cast with type %qT, "
5494 "which is not a pointer, "
5495 "reference, nor a pointer-to-data-member type", dst_type);
5496 return error_mark_node;
5499 if (TREE_CODE (TREE_TYPE (dst_type)) == FUNCTION_TYPE)
5502 error ("invalid use of const_cast with type %qT, which is a pointer "
5503 "or reference to a function type", dst_type);
5504 return error_mark_node;
5507 /* Save casted types in the function's used types hash table. */
5508 used_types_insert (dst_type);
5510 src_type = TREE_TYPE (expr);
5511 /* Expressions do not really have reference types. */
5512 if (TREE_CODE (src_type) == REFERENCE_TYPE)
5513 src_type = TREE_TYPE (src_type);
5515 /* [expr.const.cast]
5517 An lvalue of type T1 can be explicitly converted to an lvalue of
5518 type T2 using the cast const_cast<T2&> (where T1 and T2 are object
5519 types) if a pointer to T1 can be explicitly converted to the type
5520 pointer to T2 using a const_cast. */
5521 if (TREE_CODE (dst_type) == REFERENCE_TYPE)
5523 reference_type = dst_type;
5524 if (! real_lvalue_p (expr))
5527 error ("invalid const_cast of an rvalue of type %qT to type %qT",
5528 src_type, dst_type);
5529 return error_mark_node;
5531 dst_type = build_pointer_type (TREE_TYPE (dst_type));
5532 src_type = build_pointer_type (src_type);
5536 reference_type = NULL_TREE;
5537 /* If the destination type is not a reference type, the
5538 lvalue-to-rvalue, array-to-pointer, and function-to-pointer
5539 conversions are performed. */
5540 src_type = type_decays_to (src_type);
5541 if (src_type == error_mark_node)
5542 return error_mark_node;
5545 if ((TYPE_PTR_P (src_type) || TYPE_PTRMEM_P (src_type))
5546 && comp_ptr_ttypes_const (dst_type, src_type))
5551 /* This cast is actually a C-style cast. Issue a warning if
5552 the user is making a potentially unsafe cast. */
5553 check_for_casting_away_constness (src_type, dst_type, CAST_EXPR);
5557 expr = cp_build_unary_op (ADDR_EXPR, expr, 0,
5558 complain? tf_warning_or_error : tf_none);
5559 expr = build_nop (reference_type, expr);
5560 return convert_from_reference (expr);
5564 expr = decay_conversion (expr);
5565 /* build_c_cast puts on a NOP_EXPR to make the result not an
5566 lvalue. Strip such NOP_EXPRs if VALUE is being used in
5567 non-lvalue context. */
5568 if (TREE_CODE (expr) == NOP_EXPR
5569 && TREE_TYPE (expr) == TREE_TYPE (TREE_OPERAND (expr, 0)))
5570 expr = TREE_OPERAND (expr, 0);
5571 return build_nop (dst_type, expr);
5576 error ("invalid const_cast from type %qT to type %qT",
5577 src_type, dst_type);
5578 return error_mark_node;
5582 build_const_cast (tree type, tree expr, tsubst_flags_t complain)
5584 if (type == error_mark_node || error_operand_p (expr))
5585 return error_mark_node;
5587 if (processing_template_decl)
5589 tree t = build_min (CONST_CAST_EXPR, type, expr);
5591 if (!TREE_SIDE_EFFECTS (t)
5592 && type_dependent_expression_p (expr))
5593 /* There might turn out to be side effects inside expr. */
5594 TREE_SIDE_EFFECTS (t) = 1;
5595 return convert_from_reference (t);
5598 return build_const_cast_1 (type, expr, complain & tf_error,
5602 /* Like cp_build_c_cast, but for the c-common bits. */
5605 build_c_cast (tree type, tree expr)
5607 return cp_build_c_cast (type, expr, tf_warning_or_error);
5610 /* Build an expression representing an explicit C-style cast to type
5611 TYPE of expression EXPR. */
5614 cp_build_c_cast (tree type, tree expr, tsubst_flags_t complain)
5620 if (type == error_mark_node || error_operand_p (expr))
5621 return error_mark_node;
5623 if (processing_template_decl)
5625 tree t = build_min (CAST_EXPR, type,
5626 tree_cons (NULL_TREE, value, NULL_TREE));
5627 /* We don't know if it will or will not have side effects. */
5628 TREE_SIDE_EFFECTS (t) = 1;
5629 return convert_from_reference (t);
5632 /* Casts to a (pointer to a) specific ObjC class (or 'id' or
5633 'Class') should always be retained, because this information aids
5634 in method lookup. */
5635 if (objc_is_object_ptr (type)
5636 && objc_is_object_ptr (TREE_TYPE (expr)))
5637 return build_nop (type, expr);
5639 /* build_c_cast puts on a NOP_EXPR to make the result not an lvalue.
5640 Strip such NOP_EXPRs if VALUE is being used in non-lvalue context. */
5641 if (TREE_CODE (type) != REFERENCE_TYPE
5642 && TREE_CODE (value) == NOP_EXPR
5643 && TREE_TYPE (value) == TREE_TYPE (TREE_OPERAND (value, 0)))
5644 value = TREE_OPERAND (value, 0);
5646 if (TREE_CODE (type) == ARRAY_TYPE)
5648 /* Allow casting from T1* to T2[] because Cfront allows it.
5649 NIHCL uses it. It is not valid ISO C++ however. */
5650 if (TREE_CODE (TREE_TYPE (expr)) == POINTER_TYPE)
5652 if (complain & tf_error)
5653 permerror (input_location, "ISO C++ forbids casting to an array type %qT", type);
5655 return error_mark_node;
5656 type = build_pointer_type (TREE_TYPE (type));
5660 if (complain & tf_error)
5661 error ("ISO C++ forbids casting to an array type %qT", type);
5662 return error_mark_node;
5666 if (TREE_CODE (type) == FUNCTION_TYPE
5667 || TREE_CODE (type) == METHOD_TYPE)
5669 if (complain & tf_error)
5670 error ("invalid cast to function type %qT", type);
5671 return error_mark_node;
5674 /* A C-style cast can be a const_cast. */
5675 result = build_const_cast_1 (type, value, /*complain=*/false,
5680 /* Or a static cast. */
5681 result = build_static_cast_1 (type, value, /*c_cast_p=*/true,
5682 &valid_p, complain);
5683 /* Or a reinterpret_cast. */
5685 result = build_reinterpret_cast_1 (type, value, /*c_cast_p=*/true,
5686 &valid_p, complain);
5687 /* The static_cast or reinterpret_cast may be followed by a
5690 /* A valid cast may result in errors if, for example, a
5691 conversion to am ambiguous base class is required. */
5692 && !error_operand_p (result))
5696 /* Non-class rvalues always have cv-unqualified type. */
5697 if (!CLASS_TYPE_P (type))
5698 type = TYPE_MAIN_VARIANT (type);
5699 result_type = TREE_TYPE (result);
5700 if (!CLASS_TYPE_P (result_type))
5701 result_type = TYPE_MAIN_VARIANT (result_type);
5702 /* If the type of RESULT does not match TYPE, perform a
5703 const_cast to make it match. If the static_cast or
5704 reinterpret_cast succeeded, we will differ by at most
5705 cv-qualification, so the follow-on const_cast is guaranteed
5707 if (!same_type_p (non_reference (type), non_reference (result_type)))
5709 result = build_const_cast_1 (type, result, false, &valid_p);
5710 gcc_assert (valid_p);
5715 return error_mark_node;
5718 /* For use from the C common bits. */
5720 build_modify_expr (tree lhs, enum tree_code modifycode, tree rhs)
5722 return cp_build_modify_expr (lhs, modifycode, rhs, tf_warning_or_error);
5725 /* Build an assignment expression of lvalue LHS from value RHS.
5726 MODIFYCODE is the code for a binary operator that we use
5727 to combine the old value of LHS with RHS to get the new value.
5728 Or else MODIFYCODE is NOP_EXPR meaning do a simple assignment.
5730 C++: If MODIFYCODE is INIT_EXPR, then leave references unbashed. */
5733 cp_build_modify_expr (tree lhs, enum tree_code modifycode, tree rhs,
5734 tsubst_flags_t complain)
5738 tree lhstype = TREE_TYPE (lhs);
5739 tree olhstype = lhstype;
5740 tree olhs = NULL_TREE;
5741 bool plain_assign = (modifycode == NOP_EXPR);
5743 /* Avoid duplicate error messages from operands that had errors. */
5744 if (error_operand_p (lhs) || error_operand_p (rhs))
5745 return error_mark_node;
5747 /* Handle control structure constructs used as "lvalues". */
5748 switch (TREE_CODE (lhs))
5750 /* Handle --foo = 5; as these are valid constructs in C++. */
5751 case PREDECREMENT_EXPR:
5752 case PREINCREMENT_EXPR:
5753 if (TREE_SIDE_EFFECTS (TREE_OPERAND (lhs, 0)))
5754 lhs = build2 (TREE_CODE (lhs), TREE_TYPE (lhs),
5755 stabilize_reference (TREE_OPERAND (lhs, 0)),
5756 TREE_OPERAND (lhs, 1));
5757 newrhs = cp_build_modify_expr (TREE_OPERAND (lhs, 0),
5758 modifycode, rhs, complain);
5759 if (newrhs == error_mark_node)
5760 return error_mark_node;
5761 return build2 (COMPOUND_EXPR, lhstype, lhs, newrhs);
5763 /* Handle (a, b) used as an "lvalue". */
5765 newrhs = cp_build_modify_expr (TREE_OPERAND (lhs, 1),
5766 modifycode, rhs, complain);
5767 if (newrhs == error_mark_node)
5768 return error_mark_node;
5769 return build2 (COMPOUND_EXPR, lhstype,
5770 TREE_OPERAND (lhs, 0), newrhs);
5773 if (TREE_SIDE_EFFECTS (TREE_OPERAND (lhs, 0)))
5774 lhs = build2 (TREE_CODE (lhs), TREE_TYPE (lhs),
5775 stabilize_reference (TREE_OPERAND (lhs, 0)),
5776 TREE_OPERAND (lhs, 1));
5777 newrhs = cp_build_modify_expr (TREE_OPERAND (lhs, 0), modifycode, rhs,
5779 if (newrhs == error_mark_node)
5780 return error_mark_node;
5781 return build2 (COMPOUND_EXPR, lhstype, lhs, newrhs);
5785 /* MIN_EXPR and MAX_EXPR are currently only permitted as lvalues,
5786 when neither operand has side-effects. */
5787 if (!lvalue_or_else (lhs, lv_assign, complain))
5788 return error_mark_node;
5790 gcc_assert (!TREE_SIDE_EFFECTS (TREE_OPERAND (lhs, 0))
5791 && !TREE_SIDE_EFFECTS (TREE_OPERAND (lhs, 1)));
5793 lhs = build3 (COND_EXPR, TREE_TYPE (lhs),
5794 build2 (TREE_CODE (lhs) == MIN_EXPR ? LE_EXPR : GE_EXPR,
5796 TREE_OPERAND (lhs, 0),
5797 TREE_OPERAND (lhs, 1)),
5798 TREE_OPERAND (lhs, 0),
5799 TREE_OPERAND (lhs, 1));
5802 /* Handle (a ? b : c) used as an "lvalue". */
5805 /* Produce (a ? (b = rhs) : (c = rhs))
5806 except that the RHS goes through a save-expr
5807 so the code to compute it is only emitted once. */
5809 tree preeval = NULL_TREE;
5811 if (VOID_TYPE_P (TREE_TYPE (rhs)))
5813 if (complain & tf_error)
5814 error ("void value not ignored as it ought to be");
5815 return error_mark_node;
5818 rhs = stabilize_expr (rhs, &preeval);
5820 /* Check this here to avoid odd errors when trying to convert
5821 a throw to the type of the COND_EXPR. */
5822 if (!lvalue_or_else (lhs, lv_assign, complain))
5823 return error_mark_node;
5825 cond = build_conditional_expr
5826 (TREE_OPERAND (lhs, 0),
5827 cp_build_modify_expr (TREE_OPERAND (lhs, 1),
5828 modifycode, rhs, complain),
5829 cp_build_modify_expr (TREE_OPERAND (lhs, 2),
5830 modifycode, rhs, complain),
5833 if (cond == error_mark_node)
5835 /* Make sure the code to compute the rhs comes out
5836 before the split. */
5838 cond = build2 (COMPOUND_EXPR, TREE_TYPE (lhs), preeval, cond);
5846 if (modifycode == INIT_EXPR)
5848 if (TREE_CODE (rhs) == CONSTRUCTOR)
5850 if (! same_type_p (TREE_TYPE (rhs), lhstype))
5851 /* Call convert to generate an error; see PR 11063. */
5852 rhs = convert (lhstype, rhs);
5853 result = build2 (INIT_EXPR, lhstype, lhs, rhs);
5854 TREE_SIDE_EFFECTS (result) = 1;
5857 else if (! MAYBE_CLASS_TYPE_P (lhstype))
5858 /* Do the default thing. */;
5861 result = build_special_member_call (lhs, complete_ctor_identifier,
5862 build_tree_list (NULL_TREE, rhs),
5863 lhstype, LOOKUP_NORMAL,
5865 if (result == NULL_TREE)
5866 return error_mark_node;
5872 lhs = require_complete_type (lhs);
5873 if (lhs == error_mark_node)
5874 return error_mark_node;
5876 if (modifycode == NOP_EXPR)
5878 /* `operator=' is not an inheritable operator. */
5879 if (! MAYBE_CLASS_TYPE_P (lhstype))
5880 /* Do the default thing. */;
5883 result = build_new_op (MODIFY_EXPR, LOOKUP_NORMAL,
5884 lhs, rhs, make_node (NOP_EXPR),
5885 /*overloaded_p=*/NULL,
5887 if (result == NULL_TREE)
5888 return error_mark_node;
5895 /* A binary op has been requested. Combine the old LHS
5896 value with the RHS producing the value we should actually
5897 store into the LHS. */
5898 gcc_assert (!((TREE_CODE (lhstype) == REFERENCE_TYPE
5899 && MAYBE_CLASS_TYPE_P (TREE_TYPE (lhstype)))
5900 || MAYBE_CLASS_TYPE_P (lhstype)));
5902 lhs = stabilize_reference (lhs);
5903 newrhs = cp_build_binary_op (modifycode, lhs, rhs,
5905 if (newrhs == error_mark_node)
5907 if (complain & tf_error)
5908 error (" in evaluation of %<%Q(%#T, %#T)%>", modifycode,
5909 TREE_TYPE (lhs), TREE_TYPE (rhs));
5910 return error_mark_node;
5913 /* Now it looks like a plain assignment. */
5914 modifycode = NOP_EXPR;
5916 gcc_assert (TREE_CODE (lhstype) != REFERENCE_TYPE);
5917 gcc_assert (TREE_CODE (TREE_TYPE (newrhs)) != REFERENCE_TYPE);
5920 /* The left-hand side must be an lvalue. */
5921 if (!lvalue_or_else (lhs, lv_assign, complain))
5922 return error_mark_node;
5924 /* Warn about modifying something that is `const'. Don't warn if
5925 this is initialization. */
5926 if (modifycode != INIT_EXPR
5927 && (TREE_READONLY (lhs) || CP_TYPE_CONST_P (lhstype)
5928 /* Functions are not modifiable, even though they are
5930 || TREE_CODE (TREE_TYPE (lhs)) == FUNCTION_TYPE
5931 || TREE_CODE (TREE_TYPE (lhs)) == METHOD_TYPE
5932 /* If it's an aggregate and any field is const, then it is
5933 effectively const. */
5934 || (CLASS_TYPE_P (lhstype)
5935 && C_TYPE_FIELDS_READONLY (lhstype))))
5937 if (complain & tf_error)
5938 readonly_error (lhs, "assignment");
5940 return error_mark_node;
5943 /* If storing into a structure or union member, it has probably been
5944 given type `int'. Compute the type that would go with the actual
5945 amount of storage the member occupies. */
5947 if (TREE_CODE (lhs) == COMPONENT_REF
5948 && (TREE_CODE (lhstype) == INTEGER_TYPE
5949 || TREE_CODE (lhstype) == REAL_TYPE
5950 || TREE_CODE (lhstype) == ENUMERAL_TYPE))
5952 lhstype = TREE_TYPE (get_unwidened (lhs, 0));
5954 /* If storing in a field that is in actuality a short or narrower
5955 than one, we must store in the field in its actual type. */
5957 if (lhstype != TREE_TYPE (lhs))
5959 /* Avoid warnings converting integral types back into enums for
5961 if (TREE_CODE (lhstype) == INTEGER_TYPE
5962 && TREE_CODE (olhstype) == ENUMERAL_TYPE)
5964 if (TREE_SIDE_EFFECTS (lhs))
5965 lhs = stabilize_reference (lhs);
5968 lhs = copy_node (lhs);
5969 TREE_TYPE (lhs) = lhstype;
5973 /* Convert new value to destination type. */
5975 if (TREE_CODE (lhstype) == ARRAY_TYPE)
5979 if (!same_or_base_type_p (TYPE_MAIN_VARIANT (lhstype),
5980 TYPE_MAIN_VARIANT (TREE_TYPE (rhs))))
5982 if (complain & tf_error)
5983 error ("incompatible types in assignment of %qT to %qT",
5984 TREE_TYPE (rhs), lhstype);
5985 return error_mark_node;
5988 /* Allow array assignment in compiler-generated code. */
5989 if (! DECL_ARTIFICIAL (current_function_decl))
5991 /* This routine is used for both initialization and assignment.
5992 Make sure the diagnostic message differentiates the context. */
5993 if (complain & tf_error)
5995 if (modifycode == INIT_EXPR)
5996 error ("array used as initializer");
5998 error ("invalid array assignment");
6000 return error_mark_node;
6003 from_array = TREE_CODE (TREE_TYPE (newrhs)) == ARRAY_TYPE
6004 ? 1 + (modifycode != INIT_EXPR): 0;
6005 return build_vec_init (lhs, NULL_TREE, newrhs,
6006 /*explicit_value_init_p=*/false,
6007 from_array, complain);
6010 if (modifycode == INIT_EXPR)
6011 newrhs = convert_for_initialization (lhs, lhstype, newrhs, LOOKUP_NORMAL,
6012 "initialization", NULL_TREE, 0,
6016 /* Avoid warnings on enum bit fields. */
6017 if (TREE_CODE (olhstype) == ENUMERAL_TYPE
6018 && TREE_CODE (lhstype) == INTEGER_TYPE)
6020 newrhs = convert_for_assignment (olhstype, newrhs, "assignment",
6021 NULL_TREE, 0, complain);
6022 newrhs = convert_force (lhstype, newrhs, 0);
6025 newrhs = convert_for_assignment (lhstype, newrhs, "assignment",
6026 NULL_TREE, 0, complain);
6027 if (TREE_CODE (newrhs) == CALL_EXPR
6028 && TYPE_NEEDS_CONSTRUCTING (lhstype))
6029 newrhs = build_cplus_new (lhstype, newrhs);
6031 /* Can't initialize directly from a TARGET_EXPR, since that would
6032 cause the lhs to be constructed twice, and possibly result in
6033 accidental self-initialization. So we force the TARGET_EXPR to be
6034 expanded without a target. */
6035 if (TREE_CODE (newrhs) == TARGET_EXPR)
6036 newrhs = build2 (COMPOUND_EXPR, TREE_TYPE (newrhs), newrhs,
6037 TREE_OPERAND (newrhs, 0));
6040 if (newrhs == error_mark_node)
6041 return error_mark_node;
6043 if (c_dialect_objc () && flag_objc_gc)
6045 result = objc_generate_write_barrier (lhs, modifycode, newrhs);
6051 result = build2 (modifycode == NOP_EXPR ? MODIFY_EXPR : INIT_EXPR,
6052 lhstype, lhs, newrhs);
6054 TREE_SIDE_EFFECTS (result) = 1;
6056 TREE_NO_WARNING (result) = 1;
6058 /* If we got the LHS in a different type for storing in,
6059 convert the result back to the nominal type of LHS
6060 so that the value we return always has the same type
6061 as the LHS argument. */
6063 if (olhstype == TREE_TYPE (result))
6067 result = build2 (COMPOUND_EXPR, olhstype, result, olhs);
6068 TREE_NO_WARNING (result) = 1;
6071 return convert_for_assignment (olhstype, result, "assignment",
6072 NULL_TREE, 0, complain);
6076 build_x_modify_expr (tree lhs, enum tree_code modifycode, tree rhs,
6077 tsubst_flags_t complain)
6079 if (processing_template_decl)
6080 return build_min_nt (MODOP_EXPR, lhs,
6081 build_min_nt (modifycode, NULL_TREE, NULL_TREE), rhs);
6083 if (modifycode != NOP_EXPR)
6085 tree rval = build_new_op (MODIFY_EXPR, LOOKUP_NORMAL, lhs, rhs,
6086 make_node (modifycode),
6087 /*overloaded_p=*/NULL,
6091 TREE_NO_WARNING (rval) = 1;
6095 return cp_build_modify_expr (lhs, modifycode, rhs, complain);
6098 /* Helper function for get_delta_difference which assumes FROM is a base
6099 class of TO. Returns a delta for the conversion of pointer-to-member
6100 of FROM to pointer-to-member of TO. If the conversion is invalid,
6101 returns zero. If FROM is not a base class of TO, returns NULL_TREE.
6102 If C_CAST_P is true, this conversion is taking place as part of a C-style
6106 get_delta_difference_1 (tree from, tree to, bool c_cast_p)
6111 binfo = lookup_base (to, from, c_cast_p ? ba_unique : ba_check, &kind);
6112 if (kind == bk_inaccessible || kind == bk_ambig)
6114 error (" in pointer to member function conversion");
6115 return size_zero_node;
6119 if (kind != bk_via_virtual)
6120 return BINFO_OFFSET (binfo);
6122 /* FROM is a virtual base class of TO. Issue an error or warning
6123 depending on whether or not this is a reinterpret cast. */
6125 error ("pointer to member conversion via virtual base %qT",
6126 BINFO_TYPE (binfo_from_vbase (binfo)));
6128 return size_zero_node;
6135 /* Get difference in deltas for different pointer to member function
6136 types. Returns an integer constant of type PTRDIFF_TYPE_NODE. If
6137 the conversion is invalid, the constant is zero. If
6138 ALLOW_INVERSE_P is true, then allow reverse conversions as well.
6139 If C_CAST_P is true this conversion is taking place as part of a
6142 Note that the naming of FROM and TO is kind of backwards; the return
6143 value is what we add to a TO in order to get a FROM. They are named
6144 this way because we call this function to find out how to convert from
6145 a pointer to member of FROM to a pointer to member of TO. */
6148 get_delta_difference (tree from, tree to,
6149 bool allow_inverse_p,
6154 if (same_type_ignoring_top_level_qualifiers_p (from, to))
6155 /* Pointer to member of incomplete class is permitted*/
6156 result = size_zero_node;
6158 result = get_delta_difference_1 (from, to, c_cast_p);
6162 if (!allow_inverse_p)
6164 error_not_base_type (from, to);
6165 error (" in pointer to member conversion");
6166 result = size_zero_node;
6170 result = get_delta_difference_1 (to, from, c_cast_p);
6173 result = size_diffop (size_zero_node, result);
6176 error_not_base_type (from, to);
6177 error (" in pointer to member conversion");
6178 result = size_zero_node;
6183 return fold_if_not_in_template (convert_to_integer (ptrdiff_type_node,
6187 /* Return a constructor for the pointer-to-member-function TYPE using
6188 the other components as specified. */
6191 build_ptrmemfunc1 (tree type, tree delta, tree pfn)
6196 VEC(constructor_elt, gc) *v;
6198 /* Pull the FIELD_DECLs out of the type. */
6199 pfn_field = TYPE_FIELDS (type);
6200 delta_field = TREE_CHAIN (pfn_field);
6202 /* Make sure DELTA has the type we want. */
6203 delta = convert_and_check (delta_type_node, delta);
6205 /* Convert to the correct target type if necessary. */
6206 pfn = fold_convert (TREE_TYPE (pfn_field), pfn);
6208 /* Finish creating the initializer. */
6209 v = VEC_alloc(constructor_elt, gc, 2);
6210 CONSTRUCTOR_APPEND_ELT(v, pfn_field, pfn);
6211 CONSTRUCTOR_APPEND_ELT(v, delta_field, delta);
6212 u = build_constructor (type, v);
6213 TREE_CONSTANT (u) = TREE_CONSTANT (pfn) & TREE_CONSTANT (delta);
6214 TREE_STATIC (u) = (TREE_CONSTANT (u)
6215 && (initializer_constant_valid_p (pfn, TREE_TYPE (pfn))
6217 && (initializer_constant_valid_p (delta, TREE_TYPE (delta))
6222 /* Build a constructor for a pointer to member function. It can be
6223 used to initialize global variables, local variable, or used
6224 as a value in expressions. TYPE is the POINTER to METHOD_TYPE we
6227 If FORCE is nonzero, then force this conversion, even if
6228 we would rather not do it. Usually set when using an explicit
6229 cast. A C-style cast is being processed iff C_CAST_P is true.
6231 Return error_mark_node, if something goes wrong. */
6234 build_ptrmemfunc (tree type, tree pfn, int force, bool c_cast_p)
6240 if (error_operand_p (pfn))
6241 return error_mark_node;
6243 pfn_type = TREE_TYPE (pfn);
6244 to_type = build_ptrmemfunc_type (type);
6246 /* Handle multiple conversions of pointer to member functions. */
6247 if (TYPE_PTRMEMFUNC_P (pfn_type))
6249 tree delta = NULL_TREE;
6250 tree npfn = NULL_TREE;
6254 && !can_convert_arg (to_type, TREE_TYPE (pfn), pfn, LOOKUP_NORMAL))
6255 error ("invalid conversion to type %qT from type %qT",
6258 n = get_delta_difference (TYPE_PTRMEMFUNC_OBJECT_TYPE (pfn_type),
6259 TYPE_PTRMEMFUNC_OBJECT_TYPE (to_type),
6263 /* We don't have to do any conversion to convert a
6264 pointer-to-member to its own type. But, we don't want to
6265 just return a PTRMEM_CST if there's an explicit cast; that
6266 cast should make the expression an invalid template argument. */
6267 if (TREE_CODE (pfn) != PTRMEM_CST)
6269 if (same_type_p (to_type, pfn_type))
6271 else if (integer_zerop (n))
6272 return build_reinterpret_cast (to_type, pfn,
6273 tf_warning_or_error);
6276 if (TREE_SIDE_EFFECTS (pfn))
6277 pfn = save_expr (pfn);
6279 /* Obtain the function pointer and the current DELTA. */
6280 if (TREE_CODE (pfn) == PTRMEM_CST)
6281 expand_ptrmemfunc_cst (pfn, &delta, &npfn);
6284 npfn = build_ptrmemfunc_access_expr (pfn, pfn_identifier);
6285 delta = build_ptrmemfunc_access_expr (pfn, delta_identifier);
6288 /* Just adjust the DELTA field. */
6289 gcc_assert (same_type_ignoring_top_level_qualifiers_p
6290 (TREE_TYPE (delta), ptrdiff_type_node));
6291 if (TARGET_PTRMEMFUNC_VBIT_LOCATION == ptrmemfunc_vbit_in_delta)
6292 n = cp_build_binary_op (LSHIFT_EXPR, n, integer_one_node,
6293 tf_warning_or_error);
6294 delta = cp_build_binary_op (PLUS_EXPR, delta, n, tf_warning_or_error);
6295 return build_ptrmemfunc1 (to_type, delta, npfn);
6298 /* Handle null pointer to member function conversions. */
6299 if (integer_zerop (pfn))
6301 pfn = build_c_cast (type, integer_zero_node);
6302 return build_ptrmemfunc1 (to_type,
6307 if (type_unknown_p (pfn))
6308 return instantiate_type (type, pfn, tf_warning_or_error);
6310 fn = TREE_OPERAND (pfn, 0);
6311 gcc_assert (TREE_CODE (fn) == FUNCTION_DECL
6312 /* In a template, we will have preserved the
6314 || (processing_template_decl && TREE_CODE (fn) == OFFSET_REF));
6315 return make_ptrmem_cst (to_type, fn);
6318 /* Return the DELTA, IDX, PFN, and DELTA2 values for the PTRMEM_CST
6321 ??? There is no consistency as to the types returned for the above
6322 values. Some code acts as if it were a sizetype and some as if it were
6323 integer_type_node. */
6326 expand_ptrmemfunc_cst (tree cst, tree *delta, tree *pfn)
6328 tree type = TREE_TYPE (cst);
6329 tree fn = PTRMEM_CST_MEMBER (cst);
6330 tree ptr_class, fn_class;
6332 gcc_assert (TREE_CODE (fn) == FUNCTION_DECL);
6334 /* The class that the function belongs to. */
6335 fn_class = DECL_CONTEXT (fn);
6337 /* The class that we're creating a pointer to member of. */
6338 ptr_class = TYPE_PTRMEMFUNC_OBJECT_TYPE (type);
6340 /* First, calculate the adjustment to the function's class. */
6341 *delta = get_delta_difference (fn_class, ptr_class, /*force=*/0,
6344 if (!DECL_VIRTUAL_P (fn))
6345 *pfn = convert (TYPE_PTRMEMFUNC_FN_TYPE (type), build_addr_func (fn));
6348 /* If we're dealing with a virtual function, we have to adjust 'this'
6349 again, to point to the base which provides the vtable entry for
6350 fn; the call will do the opposite adjustment. */
6351 tree orig_class = DECL_CONTEXT (fn);
6352 tree binfo = binfo_or_else (orig_class, fn_class);
6353 *delta = build2 (PLUS_EXPR, TREE_TYPE (*delta),
6354 *delta, BINFO_OFFSET (binfo));
6355 *delta = fold_if_not_in_template (*delta);
6357 /* We set PFN to the vtable offset at which the function can be
6358 found, plus one (unless ptrmemfunc_vbit_in_delta, in which
6359 case delta is shifted left, and then incremented). */
6360 *pfn = DECL_VINDEX (fn);
6361 *pfn = build2 (MULT_EXPR, integer_type_node, *pfn,
6362 TYPE_SIZE_UNIT (vtable_entry_type));
6363 *pfn = fold_if_not_in_template (*pfn);
6365 switch (TARGET_PTRMEMFUNC_VBIT_LOCATION)
6367 case ptrmemfunc_vbit_in_pfn:
6368 *pfn = build2 (PLUS_EXPR, integer_type_node, *pfn,
6370 *pfn = fold_if_not_in_template (*pfn);
6373 case ptrmemfunc_vbit_in_delta:
6374 *delta = build2 (LSHIFT_EXPR, TREE_TYPE (*delta),
6375 *delta, integer_one_node);
6376 *delta = fold_if_not_in_template (*delta);
6377 *delta = build2 (PLUS_EXPR, TREE_TYPE (*delta),
6378 *delta, integer_one_node);
6379 *delta = fold_if_not_in_template (*delta);
6386 *pfn = build_nop (TYPE_PTRMEMFUNC_FN_TYPE (type), *pfn);
6387 *pfn = fold_if_not_in_template (*pfn);
6391 /* Return an expression for PFN from the pointer-to-member function
6395 pfn_from_ptrmemfunc (tree t)
6397 if (TREE_CODE (t) == PTRMEM_CST)
6402 expand_ptrmemfunc_cst (t, &delta, &pfn);
6407 return build_ptrmemfunc_access_expr (t, pfn_identifier);
6410 /* Return an expression for DELTA from the pointer-to-member function
6414 delta_from_ptrmemfunc (tree t)
6416 if (TREE_CODE (t) == PTRMEM_CST)
6421 expand_ptrmemfunc_cst (t, &delta, &pfn);
6426 return build_ptrmemfunc_access_expr (t, delta_identifier);
6429 /* Convert value RHS to type TYPE as preparation for an assignment to
6430 an lvalue of type TYPE. ERRTYPE is a string to use in error
6431 messages: "assignment", "return", etc. If FNDECL is non-NULL, we
6432 are doing the conversion in order to pass the PARMNUMth argument of
6436 convert_for_assignment (tree type, tree rhs,
6437 const char *errtype, tree fndecl, int parmnum,
6438 tsubst_flags_t complain)
6441 enum tree_code coder;
6443 /* Strip NON_LVALUE_EXPRs since we aren't using as an lvalue. */
6444 if (TREE_CODE (rhs) == NON_LVALUE_EXPR)
6445 rhs = TREE_OPERAND (rhs, 0);
6447 rhstype = TREE_TYPE (rhs);
6448 coder = TREE_CODE (rhstype);
6450 if (TREE_CODE (type) == VECTOR_TYPE && coder == VECTOR_TYPE
6451 && vector_types_convertible_p (type, rhstype, true))
6452 return convert (type, rhs);
6454 if (rhs == error_mark_node || rhstype == error_mark_node)
6455 return error_mark_node;
6456 if (TREE_CODE (rhs) == TREE_LIST && TREE_VALUE (rhs) == error_mark_node)
6457 return error_mark_node;
6459 /* The RHS of an assignment cannot have void type. */
6460 if (coder == VOID_TYPE)
6462 if (complain & tf_error)
6463 error ("void value not ignored as it ought to be");
6464 return error_mark_node;
6467 /* Simplify the RHS if possible. */
6468 if (TREE_CODE (rhs) == CONST_DECL)
6469 rhs = DECL_INITIAL (rhs);
6471 if (c_dialect_objc ())
6474 tree rname = fndecl;
6476 if (!strcmp (errtype, "assignment"))
6478 else if (!strcmp (errtype, "initialization"))
6482 tree selector = objc_message_selector ();
6486 if (selector && parmno > 1)
6493 if (objc_compare_types (type, rhstype, parmno, rname))
6494 return convert (type, rhs);
6499 The expression is implicitly converted (clause _conv_) to the
6500 cv-unqualified type of the left operand.
6502 We allow bad conversions here because by the time we get to this point
6503 we are committed to doing the conversion. If we end up doing a bad
6504 conversion, convert_like will complain. */
6505 if (!can_convert_arg_bad (type, rhstype, rhs))
6507 /* When -Wno-pmf-conversions is use, we just silently allow
6508 conversions from pointers-to-members to plain pointers. If
6509 the conversion doesn't work, cp_convert will complain. */
6511 && TYPE_PTR_P (type)
6512 && TYPE_PTRMEMFUNC_P (rhstype))
6513 rhs = cp_convert (strip_top_quals (type), rhs);
6516 if (complain & tf_error)
6518 /* If the right-hand side has unknown type, then it is an
6519 overloaded function. Call instantiate_type to get error
6521 if (rhstype == unknown_type_node)
6522 instantiate_type (type, rhs, tf_warning_or_error);
6524 error ("cannot convert %qT to %qT for argument %qP to %qD",
6525 rhstype, type, parmnum, fndecl);
6527 error ("cannot convert %qT to %qT in %s", rhstype, type,
6530 return error_mark_node;
6533 if (warn_missing_format_attribute)
6535 const enum tree_code codel = TREE_CODE (type);
6536 if ((codel == POINTER_TYPE || codel == REFERENCE_TYPE)
6538 && check_missing_format_attribute (type, rhstype)
6539 && (complain & tf_warning))
6540 warning (OPT_Wmissing_format_attribute,
6541 "%s might be a candidate for a format attribute",
6545 /* If -Wparentheses, warn about a = b = c when a has type bool and b
6547 if (warn_parentheses
6548 && type == boolean_type_node
6549 && TREE_CODE (rhs) == MODIFY_EXPR
6550 && !TREE_NO_WARNING (rhs)
6551 && TREE_TYPE (rhs) != boolean_type_node
6552 && (complain & tf_warning))
6554 warning (OPT_Wparentheses,
6555 "suggest parentheses around assignment used as truth value");
6556 TREE_NO_WARNING (rhs) = 1;
6559 return perform_implicit_conversion (strip_top_quals (type), rhs, complain);
6562 /* Convert RHS to be of type TYPE.
6563 If EXP is nonzero, it is the target of the initialization.
6564 ERRTYPE is a string to use in error messages.
6566 Two major differences between the behavior of
6567 `convert_for_assignment' and `convert_for_initialization'
6568 are that references are bashed in the former, while
6569 copied in the latter, and aggregates are assigned in
6570 the former (operator=) while initialized in the
6573 If using constructor make sure no conversion operator exists, if one does
6574 exist, an ambiguity exists.
6576 If flags doesn't include LOOKUP_COMPLAIN, don't complain about anything. */
6579 convert_for_initialization (tree exp, tree type, tree rhs, int flags,
6580 const char *errtype, tree fndecl, int parmnum,
6581 tsubst_flags_t complain)
6583 enum tree_code codel = TREE_CODE (type);
6585 enum tree_code coder;
6587 /* build_c_cast puts on a NOP_EXPR to make the result not an lvalue.
6588 Strip such NOP_EXPRs, since RHS is used in non-lvalue context. */
6589 if (TREE_CODE (rhs) == NOP_EXPR
6590 && TREE_TYPE (rhs) == TREE_TYPE (TREE_OPERAND (rhs, 0))
6591 && codel != REFERENCE_TYPE)
6592 rhs = TREE_OPERAND (rhs, 0);
6594 if (type == error_mark_node
6595 || rhs == error_mark_node
6596 || (TREE_CODE (rhs) == TREE_LIST && TREE_VALUE (rhs) == error_mark_node))
6597 return error_mark_node;
6599 if ((TREE_CODE (TREE_TYPE (rhs)) == ARRAY_TYPE
6600 && TREE_CODE (type) != ARRAY_TYPE
6601 && (TREE_CODE (type) != REFERENCE_TYPE
6602 || TREE_CODE (TREE_TYPE (type)) != ARRAY_TYPE))
6603 || (TREE_CODE (TREE_TYPE (rhs)) == FUNCTION_TYPE
6604 && (TREE_CODE (type) != REFERENCE_TYPE
6605 || TREE_CODE (TREE_TYPE (type)) != FUNCTION_TYPE))
6606 || TREE_CODE (TREE_TYPE (rhs)) == METHOD_TYPE)
6607 rhs = decay_conversion (rhs);
6609 rhstype = TREE_TYPE (rhs);
6610 coder = TREE_CODE (rhstype);
6612 if (coder == ERROR_MARK)
6613 return error_mark_node;
6615 /* We accept references to incomplete types, so we can
6616 return here before checking if RHS is of complete type. */
6618 if (codel == REFERENCE_TYPE)
6620 /* This should eventually happen in convert_arguments. */
6621 int savew = 0, savee = 0;
6624 savew = warningcount, savee = errorcount;
6625 rhs = initialize_reference (type, rhs, /*decl=*/NULL_TREE,
6629 if (warningcount > savew)
6630 warning (0, "in passing argument %P of %q+D", parmnum, fndecl);
6631 else if (errorcount > savee)
6632 error ("in passing argument %P of %q+D", parmnum, fndecl);
6638 exp = require_complete_type (exp);
6639 if (exp == error_mark_node)
6640 return error_mark_node;
6642 rhstype = non_reference (rhstype);
6644 type = complete_type (type);
6646 if (MAYBE_CLASS_TYPE_P (type))
6647 return ocp_convert (type, rhs, CONV_IMPLICIT|CONV_FORCE_TEMP, flags);
6649 return convert_for_assignment (type, rhs, errtype, fndecl, parmnum,
6653 /* If RETVAL is the address of, or a reference to, a local variable or
6654 temporary give an appropriate warning. */
6657 maybe_warn_about_returning_address_of_local (tree retval)
6659 tree valtype = TREE_TYPE (DECL_RESULT (current_function_decl));
6660 tree whats_returned = retval;
6664 if (TREE_CODE (whats_returned) == COMPOUND_EXPR)
6665 whats_returned = TREE_OPERAND (whats_returned, 1);
6666 else if (CONVERT_EXPR_P (whats_returned)
6667 || TREE_CODE (whats_returned) == NON_LVALUE_EXPR)
6668 whats_returned = TREE_OPERAND (whats_returned, 0);
6673 if (TREE_CODE (whats_returned) != ADDR_EXPR)
6675 whats_returned = TREE_OPERAND (whats_returned, 0);
6677 if (TREE_CODE (valtype) == REFERENCE_TYPE)
6679 if (TREE_CODE (whats_returned) == AGGR_INIT_EXPR
6680 || TREE_CODE (whats_returned) == TARGET_EXPR)
6682 warning (0, "returning reference to temporary");
6685 if (TREE_CODE (whats_returned) == VAR_DECL
6686 && DECL_NAME (whats_returned)
6687 && TEMP_NAME_P (DECL_NAME (whats_returned)))
6689 warning (0, "reference to non-lvalue returned");
6694 while (TREE_CODE (whats_returned) == COMPONENT_REF
6695 || TREE_CODE (whats_returned) == ARRAY_REF)
6696 whats_returned = TREE_OPERAND (whats_returned, 0);
6698 if (DECL_P (whats_returned)
6699 && DECL_NAME (whats_returned)
6700 && DECL_FUNCTION_SCOPE_P (whats_returned)
6701 && !(TREE_STATIC (whats_returned)
6702 || TREE_PUBLIC (whats_returned)))
6704 if (TREE_CODE (valtype) == REFERENCE_TYPE)
6705 warning (0, "reference to local variable %q+D returned",
6708 warning (0, "address of local variable %q+D returned",
6714 /* Check that returning RETVAL from the current function is valid.
6715 Return an expression explicitly showing all conversions required to
6716 change RETVAL into the function return type, and to assign it to
6717 the DECL_RESULT for the function. Set *NO_WARNING to true if
6718 code reaches end of non-void function warning shouldn't be issued
6719 on this RETURN_EXPR. */
6722 check_return_expr (tree retval, bool *no_warning)
6725 /* The type actually returned by the function, after any
6728 int fn_returns_value_p;
6729 bool named_return_value_okay_p;
6731 *no_warning = false;
6733 /* A `volatile' function is one that isn't supposed to return, ever.
6734 (This is a G++ extension, used to get better code for functions
6735 that call the `volatile' function.) */
6736 if (TREE_THIS_VOLATILE (current_function_decl))
6737 warning (0, "function declared %<noreturn%> has a %<return%> statement");
6739 /* Check for various simple errors. */
6740 if (DECL_DESTRUCTOR_P (current_function_decl))
6743 error ("returning a value from a destructor");
6746 else if (DECL_CONSTRUCTOR_P (current_function_decl))
6748 if (in_function_try_handler)
6749 /* If a return statement appears in a handler of the
6750 function-try-block of a constructor, the program is ill-formed. */
6751 error ("cannot return from a handler of a function-try-block of a constructor");
6753 /* You can't return a value from a constructor. */
6754 error ("returning a value from a constructor");
6758 if (processing_template_decl)
6760 current_function_returns_value = 1;
6761 if (check_for_bare_parameter_packs (retval))
6762 retval = error_mark_node;
6766 /* When no explicit return-value is given in a function with a named
6767 return value, the named return value is used. */
6768 result = DECL_RESULT (current_function_decl);
6769 valtype = TREE_TYPE (result);
6770 gcc_assert (valtype != NULL_TREE);
6771 fn_returns_value_p = !VOID_TYPE_P (valtype);
6772 if (!retval && DECL_NAME (result) && fn_returns_value_p)
6775 /* Check for a return statement with no return value in a function
6776 that's supposed to return a value. */
6777 if (!retval && fn_returns_value_p)
6779 permerror (input_location, "return-statement with no value, in function returning %qT",
6781 /* Clear this, so finish_function won't say that we reach the
6782 end of a non-void function (which we don't, we gave a
6784 current_function_returns_null = 0;
6785 /* And signal caller that TREE_NO_WARNING should be set on the
6786 RETURN_EXPR to avoid control reaches end of non-void function
6787 warnings in tree-cfg.c. */
6790 /* Check for a return statement with a value in a function that
6791 isn't supposed to return a value. */
6792 else if (retval && !fn_returns_value_p)
6794 if (VOID_TYPE_P (TREE_TYPE (retval)))
6795 /* You can return a `void' value from a function of `void'
6796 type. In that case, we have to evaluate the expression for
6797 its side-effects. */
6798 finish_expr_stmt (retval);
6800 permerror (input_location, "return-statement with a value, in function "
6801 "returning 'void'");
6802 current_function_returns_null = 1;
6804 /* There's really no value to return, after all. */
6808 /* Remember that this function can sometimes return without a
6810 current_function_returns_null = 1;
6812 /* Remember that this function did return a value. */
6813 current_function_returns_value = 1;
6815 /* Check for erroneous operands -- but after giving ourselves a
6816 chance to provide an error about returning a value from a void
6818 if (error_operand_p (retval))
6820 current_function_return_value = error_mark_node;
6821 return error_mark_node;
6824 /* Only operator new(...) throw(), can return NULL [expr.new/13]. */
6825 if ((DECL_OVERLOADED_OPERATOR_P (current_function_decl) == NEW_EXPR
6826 || DECL_OVERLOADED_OPERATOR_P (current_function_decl) == VEC_NEW_EXPR)
6827 && !TYPE_NOTHROW_P (TREE_TYPE (current_function_decl))
6829 && retval && null_ptr_cst_p (retval))
6830 warning (0, "%<operator new%> must not return NULL unless it is "
6831 "declared %<throw()%> (or -fcheck-new is in effect)");
6833 /* Effective C++ rule 15. See also start_function. */
6835 && DECL_NAME (current_function_decl) == ansi_assopname(NOP_EXPR))
6839 /* The function return type must be a reference to the current
6841 if (TREE_CODE (valtype) == REFERENCE_TYPE
6842 && same_type_ignoring_top_level_qualifiers_p
6843 (TREE_TYPE (valtype), TREE_TYPE (current_class_ref)))
6845 /* Returning '*this' is obviously OK. */
6846 if (retval == current_class_ref)
6848 /* If we are calling a function whose return type is the same of
6849 the current class reference, it is ok. */
6850 else if (TREE_CODE (retval) == INDIRECT_REF
6851 && TREE_CODE (TREE_OPERAND (retval, 0)) == CALL_EXPR)
6856 warning (OPT_Weffc__, "%<operator=%> should return a reference to %<*this%>");
6859 /* The fabled Named Return Value optimization, as per [class.copy]/15:
6861 [...] For a function with a class return type, if the expression
6862 in the return statement is the name of a local object, and the cv-
6863 unqualified type of the local object is the same as the function
6864 return type, an implementation is permitted to omit creating the tem-
6865 porary object to hold the function return value [...]
6867 So, if this is a value-returning function that always returns the same
6868 local variable, remember it.
6870 It might be nice to be more flexible, and choose the first suitable
6871 variable even if the function sometimes returns something else, but
6872 then we run the risk of clobbering the variable we chose if the other
6873 returned expression uses the chosen variable somehow. And people expect
6874 this restriction, anyway. (jason 2000-11-19)
6876 See finish_function and finalize_nrv for the rest of this optimization. */
6878 named_return_value_okay_p =
6879 (retval != NULL_TREE
6880 /* Must be a local, automatic variable. */
6881 && TREE_CODE (retval) == VAR_DECL
6882 && DECL_CONTEXT (retval) == current_function_decl
6883 && ! TREE_STATIC (retval)
6884 && ! DECL_ANON_UNION_VAR_P (retval)
6885 && (DECL_ALIGN (retval)
6886 >= DECL_ALIGN (DECL_RESULT (current_function_decl)))
6887 /* The cv-unqualified type of the returned value must be the
6888 same as the cv-unqualified return type of the
6890 && same_type_p ((TYPE_MAIN_VARIANT (TREE_TYPE (retval))),
6892 (TREE_TYPE (TREE_TYPE (current_function_decl)))))
6893 /* And the returned value must be non-volatile. */
6894 && ! TYPE_VOLATILE (TREE_TYPE (retval)));
6896 if (fn_returns_value_p && flag_elide_constructors)
6898 if (named_return_value_okay_p
6899 && (current_function_return_value == NULL_TREE
6900 || current_function_return_value == retval))
6901 current_function_return_value = retval;
6903 current_function_return_value = error_mark_node;
6906 /* We don't need to do any conversions when there's nothing being
6911 /* Do any required conversions. */
6912 if (retval == result || DECL_CONSTRUCTOR_P (current_function_decl))
6913 /* No conversions are required. */
6917 /* The type the function is declared to return. */
6918 tree functype = TREE_TYPE (TREE_TYPE (current_function_decl));
6919 int flags = LOOKUP_NORMAL | LOOKUP_ONLYCONVERTING;
6921 /* The functype's return type will have been set to void, if it
6922 was an incomplete type. Just treat this as 'return;' */
6923 if (VOID_TYPE_P (functype))
6924 return error_mark_node;
6926 /* Under C++0x [12.8/16 class.copy], a returned lvalue is sometimes
6927 treated as an rvalue for the purposes of overload resolution to
6928 favor move constructors over copy constructors. */
6929 if ((cxx_dialect != cxx98)
6930 && named_return_value_okay_p
6931 /* The variable must not have the `volatile' qualifier. */
6932 && !(cp_type_quals (TREE_TYPE (retval)) & TYPE_QUAL_VOLATILE)
6933 /* The return type must be a class type. */
6934 && CLASS_TYPE_P (TREE_TYPE (TREE_TYPE (current_function_decl))))
6935 flags = flags | LOOKUP_PREFER_RVALUE;
6937 /* First convert the value to the function's return type, then
6938 to the type of return value's location to handle the
6939 case that functype is smaller than the valtype. */
6940 retval = convert_for_initialization
6941 (NULL_TREE, functype, retval, flags, "return", NULL_TREE, 0,
6942 tf_warning_or_error);
6943 retval = convert (valtype, retval);
6945 /* If the conversion failed, treat this just like `return;'. */
6946 if (retval == error_mark_node)
6948 /* We can't initialize a register from a AGGR_INIT_EXPR. */
6949 else if (! cfun->returns_struct
6950 && TREE_CODE (retval) == TARGET_EXPR
6951 && TREE_CODE (TREE_OPERAND (retval, 1)) == AGGR_INIT_EXPR)
6952 retval = build2 (COMPOUND_EXPR, TREE_TYPE (retval), retval,
6953 TREE_OPERAND (retval, 0));
6955 maybe_warn_about_returning_address_of_local (retval);
6958 /* Actually copy the value returned into the appropriate location. */
6959 if (retval && retval != result)
6960 retval = build2 (INIT_EXPR, TREE_TYPE (result), result, retval);
6966 /* Returns nonzero if the pointer-type FROM can be converted to the
6967 pointer-type TO via a qualification conversion. If CONSTP is -1,
6968 then we return nonzero if the pointers are similar, and the
6969 cv-qualification signature of FROM is a proper subset of that of TO.
6971 If CONSTP is positive, then all outer pointers have been
6975 comp_ptr_ttypes_real (tree to, tree from, int constp)
6977 bool to_more_cv_qualified = false;
6978 bool is_opaque_pointer = false;
6980 for (; ; to = TREE_TYPE (to), from = TREE_TYPE (from))
6982 if (TREE_CODE (to) != TREE_CODE (from))
6985 if (TREE_CODE (from) == OFFSET_TYPE
6986 && !same_type_p (TYPE_OFFSET_BASETYPE (from),
6987 TYPE_OFFSET_BASETYPE (to)))
6990 /* Const and volatile mean something different for function types,
6991 so the usual checks are not appropriate. */
6992 if (TREE_CODE (to) != FUNCTION_TYPE && TREE_CODE (to) != METHOD_TYPE)
6994 /* In Objective-C++, some types may have been 'volatilized' by
6995 the compiler for EH; when comparing them here, the volatile
6996 qualification must be ignored. */
6997 bool objc_quals_match = objc_type_quals_match (to, from);
6999 if (!at_least_as_qualified_p (to, from) && !objc_quals_match)
7002 if (!at_least_as_qualified_p (from, to) && !objc_quals_match)
7006 to_more_cv_qualified = true;
7010 constp &= TYPE_READONLY (to);
7013 if (TREE_CODE (to) == VECTOR_TYPE)
7014 is_opaque_pointer = vector_targets_convertible_p (to, from);
7016 if (TREE_CODE (to) != POINTER_TYPE && !TYPE_PTRMEM_P (to))
7017 return ((constp >= 0 || to_more_cv_qualified)
7018 && (is_opaque_pointer
7019 || same_type_ignoring_top_level_qualifiers_p (to, from)));
7023 /* When comparing, say, char ** to char const **, this function takes
7024 the 'char *' and 'char const *'. Do not pass non-pointer/reference
7025 types to this function. */
7028 comp_ptr_ttypes (tree to, tree from)
7030 return comp_ptr_ttypes_real (to, from, 1);
7033 /* Returns 1 if to and from are (possibly multi-level) pointers to the same
7034 type or inheritance-related types, regardless of cv-quals. */
7037 ptr_reasonably_similar (const_tree to, const_tree from)
7039 for (; ; to = TREE_TYPE (to), from = TREE_TYPE (from))
7041 /* Any target type is similar enough to void. */
7042 if (TREE_CODE (to) == VOID_TYPE
7043 || TREE_CODE (from) == VOID_TYPE)
7046 if (TREE_CODE (to) != TREE_CODE (from))
7049 if (TREE_CODE (from) == OFFSET_TYPE
7050 && comptypes (TYPE_OFFSET_BASETYPE (to),
7051 TYPE_OFFSET_BASETYPE (from),
7052 COMPARE_BASE | COMPARE_DERIVED))
7055 if (TREE_CODE (to) == VECTOR_TYPE
7056 && vector_types_convertible_p (to, from, false))
7059 if (TREE_CODE (to) == INTEGER_TYPE
7060 && TYPE_PRECISION (to) == TYPE_PRECISION (from))
7063 if (TREE_CODE (to) == FUNCTION_TYPE)
7066 if (TREE_CODE (to) != POINTER_TYPE)
7068 (TYPE_MAIN_VARIANT (to), TYPE_MAIN_VARIANT (from),
7069 COMPARE_BASE | COMPARE_DERIVED);
7073 /* Return true if TO and FROM (both of which are POINTER_TYPEs or
7074 pointer-to-member types) are the same, ignoring cv-qualification at
7078 comp_ptr_ttypes_const (tree to, tree from)
7080 bool is_opaque_pointer = false;
7082 for (; ; to = TREE_TYPE (to), from = TREE_TYPE (from))
7084 if (TREE_CODE (to) != TREE_CODE (from))
7087 if (TREE_CODE (from) == OFFSET_TYPE
7088 && same_type_p (TYPE_OFFSET_BASETYPE (from),
7089 TYPE_OFFSET_BASETYPE (to)))
7092 if (TREE_CODE (to) == VECTOR_TYPE)
7093 is_opaque_pointer = vector_targets_convertible_p (to, from);
7095 if (TREE_CODE (to) != POINTER_TYPE)
7096 return (is_opaque_pointer
7097 || same_type_ignoring_top_level_qualifiers_p (to, from));
7101 /* Returns the type qualifiers for this type, including the qualifiers on the
7102 elements for an array type. */
7105 cp_type_quals (const_tree type)
7107 /* This CONST_CAST is okay because strip_array_types returns its
7108 argument unmodified and we assign it to a const_tree. */
7109 type = strip_array_types (CONST_CAST_TREE(type));
7110 if (type == error_mark_node)
7111 return TYPE_UNQUALIFIED;
7112 return TYPE_QUALS (type);
7115 /* Returns nonzero if the TYPE is const from a C++ perspective: look inside
7119 cp_type_readonly (const_tree type)
7121 /* This CONST_CAST is okay because strip_array_types returns its
7122 argument unmodified and we assign it to a const_tree. */
7123 type = strip_array_types (CONST_CAST_TREE(type));
7124 return TYPE_READONLY (type);
7127 /* Returns nonzero if the TYPE contains a mutable member. */
7130 cp_has_mutable_p (const_tree type)
7132 /* This CONST_CAST is okay because strip_array_types returns its
7133 argument unmodified and we assign it to a const_tree. */
7134 type = strip_array_types (CONST_CAST_TREE(type));
7136 return CLASS_TYPE_P (type) && CLASSTYPE_HAS_MUTABLE (type);
7139 /* Set TREE_READONLY and TREE_VOLATILE on DECL as indicated by the
7140 TYPE_QUALS. For a VAR_DECL, this may be an optimistic
7141 approximation. In particular, consider:
7144 struct S { int i; };
7145 const S s = { f(); }
7147 Here, we will make "s" as TREE_READONLY (because it is declared
7148 "const") -- only to reverse ourselves upon seeing that the
7149 initializer is non-constant. */
7152 cp_apply_type_quals_to_decl (int type_quals, tree decl)
7154 tree type = TREE_TYPE (decl);
7156 if (type == error_mark_node)
7159 if (TREE_CODE (type) == FUNCTION_TYPE
7160 && type_quals != TYPE_UNQUALIFIED)
7162 /* This was an error in C++98 (cv-qualifiers cannot be added to
7163 a function type), but DR 295 makes the code well-formed by
7164 dropping the extra qualifiers. */
7167 tree bad_type = build_qualified_type (type, type_quals);
7168 pedwarn (input_location, OPT_pedantic,
7169 "ignoring %qV qualifiers added to function type %qT",
7173 TREE_TYPE (decl) = TYPE_MAIN_VARIANT (type);
7177 /* Avoid setting TREE_READONLY incorrectly. */
7178 if (/* If the object has a constructor, the constructor may modify
7180 TYPE_NEEDS_CONSTRUCTING (type)
7181 /* If the type isn't complete, we don't know yet if it will need
7183 || !COMPLETE_TYPE_P (type)
7184 /* If the type has a mutable component, that component might be
7186 || TYPE_HAS_MUTABLE_P (type))
7187 type_quals &= ~TYPE_QUAL_CONST;
7189 c_apply_type_quals_to_decl (type_quals, decl);
7192 /* Subroutine of casts_away_constness. Make T1 and T2 point at
7193 exemplar types such that casting T1 to T2 is casting away constness
7194 if and only if there is no implicit conversion from T1 to T2. */
7197 casts_away_constness_r (tree *t1, tree *t2)
7202 /* [expr.const.cast]
7204 For multi-level pointer to members and multi-level mixed pointers
7205 and pointers to members (conv.qual), the "member" aspect of a
7206 pointer to member level is ignored when determining if a const
7207 cv-qualifier has been cast away. */
7208 /* [expr.const.cast]
7210 For two pointer types:
7212 X1 is T1cv1,1 * ... cv1,N * where T1 is not a pointer type
7213 X2 is T2cv2,1 * ... cv2,M * where T2 is not a pointer type
7216 casting from X1 to X2 casts away constness if, for a non-pointer
7217 type T there does not exist an implicit conversion (clause
7220 Tcv1,(N-K+1) * cv1,(N-K+2) * ... cv1,N *
7224 Tcv2,(M-K+1) * cv2,(M-K+2) * ... cv2,M *. */
7225 if ((!TYPE_PTR_P (*t1) && !TYPE_PTRMEM_P (*t1))
7226 || (!TYPE_PTR_P (*t2) && !TYPE_PTRMEM_P (*t2)))
7228 *t1 = cp_build_qualified_type (void_type_node,
7229 cp_type_quals (*t1));
7230 *t2 = cp_build_qualified_type (void_type_node,
7231 cp_type_quals (*t2));
7235 quals1 = cp_type_quals (*t1);
7236 quals2 = cp_type_quals (*t2);
7238 if (TYPE_PTRMEM_P (*t1))
7239 *t1 = TYPE_PTRMEM_POINTED_TO_TYPE (*t1);
7241 *t1 = TREE_TYPE (*t1);
7242 if (TYPE_PTRMEM_P (*t2))
7243 *t2 = TYPE_PTRMEM_POINTED_TO_TYPE (*t2);
7245 *t2 = TREE_TYPE (*t2);
7247 casts_away_constness_r (t1, t2);
7248 *t1 = build_pointer_type (*t1);
7249 *t2 = build_pointer_type (*t2);
7250 *t1 = cp_build_qualified_type (*t1, quals1);
7251 *t2 = cp_build_qualified_type (*t2, quals2);
7254 /* Returns nonzero if casting from TYPE1 to TYPE2 casts away
7258 casts_away_constness (tree t1, tree t2)
7260 if (TREE_CODE (t2) == REFERENCE_TYPE)
7262 /* [expr.const.cast]
7264 Casting from an lvalue of type T1 to an lvalue of type T2
7265 using a reference cast casts away constness if a cast from an
7266 rvalue of type "pointer to T1" to the type "pointer to T2"
7267 casts away constness. */
7268 t1 = (TREE_CODE (t1) == REFERENCE_TYPE ? TREE_TYPE (t1) : t1);
7269 return casts_away_constness (build_pointer_type (t1),
7270 build_pointer_type (TREE_TYPE (t2)));
7273 if (TYPE_PTRMEM_P (t1) && TYPE_PTRMEM_P (t2))
7274 /* [expr.const.cast]
7276 Casting from an rvalue of type "pointer to data member of X
7277 of type T1" to the type "pointer to data member of Y of type
7278 T2" casts away constness if a cast from an rvalue of type
7279 "pointer to T1" to the type "pointer to T2" casts away
7281 return casts_away_constness
7282 (build_pointer_type (TYPE_PTRMEM_POINTED_TO_TYPE (t1)),
7283 build_pointer_type (TYPE_PTRMEM_POINTED_TO_TYPE (t2)));
7285 /* Casting away constness is only something that makes sense for
7286 pointer or reference types. */
7287 if (TREE_CODE (t1) != POINTER_TYPE
7288 || TREE_CODE (t2) != POINTER_TYPE)
7291 /* Top-level qualifiers don't matter. */
7292 t1 = TYPE_MAIN_VARIANT (t1);
7293 t2 = TYPE_MAIN_VARIANT (t2);
7294 casts_away_constness_r (&t1, &t2);
7295 if (!can_convert (t2, t1))
7301 /* If T is a REFERENCE_TYPE return the type to which T refers.
7302 Otherwise, return T itself. */
7305 non_reference (tree t)
7307 if (TREE_CODE (t) == REFERENCE_TYPE)
7313 /* Return nonzero if REF is an lvalue valid for this language;
7314 otherwise, print an error message and return zero. USE says
7315 how the lvalue is being used and so selects the error message. */
7318 lvalue_or_else (const_tree ref, enum lvalue_use use, tsubst_flags_t complain)
7320 int win = lvalue_p (ref);
7322 if (!win && (complain & tf_error))