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
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 2, 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 COPYING. If not, write to
21 the Free Software Foundation, 51 Franklin Street, Fifth Floor,
22 Boston, MA 02110-1301, USA. */
25 /* This file is part of the C++ front end.
26 It contains routines to build C++ expressions given their operands,
27 including computing the types of the result, C and C++ specific error
28 checks, and some optimization. */
32 #include "coretypes.h"
42 #include "diagnostic.h"
49 static tree pfn_from_ptrmemfunc (tree);
50 static tree convert_for_assignment (tree, tree, const char *, tree, int);
51 static tree cp_pointer_int_sum (enum tree_code, tree, tree);
52 static tree rationalize_conditional_expr (enum tree_code, tree);
53 static int comp_ptr_ttypes_real (tree, tree, int);
54 static bool comp_except_types (tree, tree, bool);
55 static bool comp_array_types (tree, tree, bool);
56 static tree pointer_diff (tree, tree, tree);
57 static tree get_delta_difference (tree, tree, bool, bool);
58 static void casts_away_constness_r (tree *, tree *);
59 static bool casts_away_constness (tree, tree);
60 static void maybe_warn_about_returning_address_of_local (tree);
61 static tree lookup_destructor (tree, tree, tree);
62 static int convert_arguments (int, tree *, tree, tree, tree, int);
64 /* Do `exp = require_complete_type (exp);' to make sure exp
65 does not have an incomplete type. (That includes void types.)
66 Returns the error_mark_node if the VALUE does not have
67 complete type when this function returns. */
70 require_complete_type (tree value)
74 if (processing_template_decl || value == error_mark_node)
77 if (TREE_CODE (value) == OVERLOAD)
78 type = unknown_type_node;
80 type = TREE_TYPE (value);
82 if (type == error_mark_node)
83 return error_mark_node;
85 /* First, detect a valid value with a complete type. */
86 if (COMPLETE_TYPE_P (type))
89 if (complete_type_or_else (type, value))
92 return error_mark_node;
95 /* Try to complete TYPE, if it is incomplete. For example, if TYPE is
96 a template instantiation, do the instantiation. Returns TYPE,
97 whether or not it could be completed, unless something goes
98 horribly wrong, in which case the error_mark_node is returned. */
101 complete_type (tree type)
103 if (type == NULL_TREE)
104 /* Rather than crash, we return something sure to cause an error
106 return error_mark_node;
108 if (type == error_mark_node || COMPLETE_TYPE_P (type))
110 else if (TREE_CODE (type) == ARRAY_TYPE && TYPE_DOMAIN (type))
112 tree t = complete_type (TREE_TYPE (type));
113 unsigned int needs_constructing, has_nontrivial_dtor;
114 if (COMPLETE_TYPE_P (t) && !dependent_type_p (type))
117 = TYPE_NEEDS_CONSTRUCTING (TYPE_MAIN_VARIANT (t));
119 = TYPE_HAS_NONTRIVIAL_DESTRUCTOR (TYPE_MAIN_VARIANT (t));
120 for (t = TYPE_MAIN_VARIANT (type); t; t = TYPE_NEXT_VARIANT (t))
122 TYPE_NEEDS_CONSTRUCTING (t) = needs_constructing;
123 TYPE_HAS_NONTRIVIAL_DESTRUCTOR (t) = has_nontrivial_dtor;
126 else if (CLASS_TYPE_P (type) && CLASSTYPE_TEMPLATE_INSTANTIATION (type))
127 instantiate_class_template (TYPE_MAIN_VARIANT (type));
132 /* Like complete_type, but issue an error if the TYPE cannot be completed.
133 VALUE is used for informative diagnostics.
134 Returns NULL_TREE if the type cannot be made complete. */
137 complete_type_or_else (tree type, tree value)
139 type = complete_type (type);
140 if (type == error_mark_node)
141 /* We already issued an error. */
143 else if (!COMPLETE_TYPE_P (type))
145 cxx_incomplete_type_diagnostic (value, type, 0);
152 /* Return truthvalue of whether type of EXP is instantiated. */
155 type_unknown_p (tree exp)
157 return (TREE_CODE (exp) == TREE_LIST
158 || TREE_TYPE (exp) == unknown_type_node);
162 /* Return the common type of two parameter lists.
163 We assume that comptypes has already been done and returned 1;
164 if that isn't so, this may crash.
166 As an optimization, free the space we allocate if the parameter
167 lists are already common. */
170 commonparms (tree p1, tree p2)
172 tree oldargs = p1, newargs, n;
176 len = list_length (p1);
177 newargs = tree_last (p1);
179 if (newargs == void_list_node)
188 newargs = tree_cons (NULL_TREE, NULL_TREE, newargs);
193 p1 = TREE_CHAIN (p1), p2 = TREE_CHAIN (p2), n = TREE_CHAIN (n), i++)
195 if (TREE_PURPOSE (p1) && !TREE_PURPOSE (p2))
197 TREE_PURPOSE (n) = TREE_PURPOSE (p1);
200 else if (! TREE_PURPOSE (p1))
202 if (TREE_PURPOSE (p2))
204 TREE_PURPOSE (n) = TREE_PURPOSE (p2);
210 if (1 != simple_cst_equal (TREE_PURPOSE (p1), TREE_PURPOSE (p2)))
212 TREE_PURPOSE (n) = TREE_PURPOSE (p2);
214 if (TREE_VALUE (p1) != TREE_VALUE (p2))
217 TREE_VALUE (n) = merge_types (TREE_VALUE (p1), TREE_VALUE (p2));
220 TREE_VALUE (n) = TREE_VALUE (p1);
228 /* Given a type, perhaps copied for a typedef,
229 find the "original" version of it. */
231 original_type (tree t)
233 int quals = cp_type_quals (t);
234 while (t != error_mark_node
235 && TYPE_NAME (t) != NULL_TREE)
237 tree x = TYPE_NAME (t);
238 if (TREE_CODE (x) != TYPE_DECL)
240 x = DECL_ORIGINAL_TYPE (x);
245 return cp_build_qualified_type (t, quals);
248 /* T1 and T2 are arithmetic or enumeration types. Return the type
249 that will result from the "usual arithmetic conversions" on T1 and
250 T2 as described in [expr]. */
253 type_after_usual_arithmetic_conversions (tree t1, tree t2)
255 enum tree_code code1 = TREE_CODE (t1);
256 enum tree_code code2 = TREE_CODE (t2);
259 /* FIXME: Attributes. */
260 gcc_assert (ARITHMETIC_TYPE_P (t1)
261 || TREE_CODE (t1) == VECTOR_TYPE
262 || TREE_CODE (t1) == ENUMERAL_TYPE);
263 gcc_assert (ARITHMETIC_TYPE_P (t2)
264 || TREE_CODE (t2) == VECTOR_TYPE
265 || TREE_CODE (t2) == ENUMERAL_TYPE);
267 /* In what follows, we slightly generalize the rules given in [expr] so
268 as to deal with `long long' and `complex'. First, merge the
270 attributes = (*targetm.merge_type_attributes) (t1, t2);
272 /* If one type is complex, form the common type of the non-complex
273 components, then make that complex. Use T1 or T2 if it is the
275 if (code1 == COMPLEX_TYPE || code2 == COMPLEX_TYPE)
277 tree subtype1 = code1 == COMPLEX_TYPE ? TREE_TYPE (t1) : t1;
278 tree subtype2 = code2 == COMPLEX_TYPE ? TREE_TYPE (t2) : t2;
280 = type_after_usual_arithmetic_conversions (subtype1, subtype2);
282 if (code1 == COMPLEX_TYPE && TREE_TYPE (t1) == subtype)
283 return build_type_attribute_variant (t1, attributes);
284 else if (code2 == COMPLEX_TYPE && TREE_TYPE (t2) == subtype)
285 return build_type_attribute_variant (t2, attributes);
287 return build_type_attribute_variant (build_complex_type (subtype),
291 if (code1 == VECTOR_TYPE)
293 /* When we get here we should have two vectors of the same size.
294 Just prefer the unsigned one if present. */
295 if (TYPE_UNSIGNED (t1))
296 return build_type_attribute_variant (t1, attributes);
298 return build_type_attribute_variant (t2, attributes);
301 /* If only one is real, use it as the result. */
302 if (code1 == REAL_TYPE && code2 != REAL_TYPE)
303 return build_type_attribute_variant (t1, attributes);
304 if (code2 == REAL_TYPE && code1 != REAL_TYPE)
305 return build_type_attribute_variant (t2, attributes);
307 /* Perform the integral promotions. */
308 if (code1 != REAL_TYPE)
310 t1 = type_promotes_to (t1);
311 t2 = type_promotes_to (t2);
314 /* Both real or both integers; use the one with greater precision. */
315 if (TYPE_PRECISION (t1) > TYPE_PRECISION (t2))
316 return build_type_attribute_variant (t1, attributes);
317 else if (TYPE_PRECISION (t2) > TYPE_PRECISION (t1))
318 return build_type_attribute_variant (t2, attributes);
320 /* The types are the same; no need to do anything fancy. */
321 if (TYPE_MAIN_VARIANT (t1) == TYPE_MAIN_VARIANT (t2))
322 return build_type_attribute_variant (t1, attributes);
324 if (code1 != REAL_TYPE)
326 /* If one is unsigned long long, then convert the other to unsigned
328 if (same_type_p (TYPE_MAIN_VARIANT (t1), long_long_unsigned_type_node)
329 || same_type_p (TYPE_MAIN_VARIANT (t2), long_long_unsigned_type_node))
330 return build_type_attribute_variant (long_long_unsigned_type_node,
332 /* If one is a long long, and the other is an unsigned long, and
333 long long can represent all the values of an unsigned long, then
334 convert to a long long. Otherwise, convert to an unsigned long
335 long. Otherwise, if either operand is long long, convert the
338 Since we're here, we know the TYPE_PRECISION is the same;
339 therefore converting to long long cannot represent all the values
340 of an unsigned long, so we choose unsigned long long in that
342 if (same_type_p (TYPE_MAIN_VARIANT (t1), long_long_integer_type_node)
343 || same_type_p (TYPE_MAIN_VARIANT (t2), long_long_integer_type_node))
345 tree t = ((TYPE_UNSIGNED (t1) || TYPE_UNSIGNED (t2))
346 ? long_long_unsigned_type_node
347 : long_long_integer_type_node);
348 return build_type_attribute_variant (t, attributes);
351 /* Go through the same procedure, but for longs. */
352 if (same_type_p (TYPE_MAIN_VARIANT (t1), long_unsigned_type_node)
353 || same_type_p (TYPE_MAIN_VARIANT (t2), long_unsigned_type_node))
354 return build_type_attribute_variant (long_unsigned_type_node,
356 if (same_type_p (TYPE_MAIN_VARIANT (t1), long_integer_type_node)
357 || same_type_p (TYPE_MAIN_VARIANT (t2), long_integer_type_node))
359 tree t = ((TYPE_UNSIGNED (t1) || TYPE_UNSIGNED (t2))
360 ? long_unsigned_type_node : long_integer_type_node);
361 return build_type_attribute_variant (t, attributes);
363 /* Otherwise prefer the unsigned one. */
364 if (TYPE_UNSIGNED (t1))
365 return build_type_attribute_variant (t1, attributes);
367 return build_type_attribute_variant (t2, attributes);
371 if (same_type_p (TYPE_MAIN_VARIANT (t1), long_double_type_node)
372 || same_type_p (TYPE_MAIN_VARIANT (t2), long_double_type_node))
373 return build_type_attribute_variant (long_double_type_node,
375 if (same_type_p (TYPE_MAIN_VARIANT (t1), double_type_node)
376 || same_type_p (TYPE_MAIN_VARIANT (t2), double_type_node))
377 return build_type_attribute_variant (double_type_node,
379 if (same_type_p (TYPE_MAIN_VARIANT (t1), float_type_node)
380 || same_type_p (TYPE_MAIN_VARIANT (t2), float_type_node))
381 return build_type_attribute_variant (float_type_node,
384 /* Two floating-point types whose TYPE_MAIN_VARIANTs are none of
385 the standard C++ floating-point types. Logic earlier in this
386 function has already eliminated the possibility that
387 TYPE_PRECISION (t2) != TYPE_PRECISION (t1), so there's no
388 compelling reason to choose one or the other. */
389 return build_type_attribute_variant (t1, attributes);
393 /* Subroutine of composite_pointer_type to implement the recursive
394 case. See that function for documentation fo the parameters. */
397 composite_pointer_type_r (tree t1, tree t2, const char* location)
404 /* Determine the types pointed to by T1 and T2. */
405 if (TREE_CODE (t1) == POINTER_TYPE)
407 pointee1 = TREE_TYPE (t1);
408 pointee2 = TREE_TYPE (t2);
412 pointee1 = TYPE_PTRMEM_POINTED_TO_TYPE (t1);
413 pointee2 = TYPE_PTRMEM_POINTED_TO_TYPE (t2);
418 Otherwise, the composite pointer type is a pointer type
419 similar (_conv.qual_) to the type of one of the operands,
420 with a cv-qualification signature (_conv.qual_) that is the
421 union of the cv-qualification signatures of the operand
423 if (same_type_ignoring_top_level_qualifiers_p (pointee1, pointee2))
424 result_type = pointee1;
425 else if ((TREE_CODE (pointee1) == POINTER_TYPE
426 && TREE_CODE (pointee2) == POINTER_TYPE)
427 || (TYPE_PTR_TO_MEMBER_P (pointee1)
428 && TYPE_PTR_TO_MEMBER_P (pointee2)))
429 result_type = composite_pointer_type_r (pointee1, pointee2, location);
432 pedwarn ("%s between distinct pointer types %qT and %qT "
435 result_type = void_type_node;
437 result_type = cp_build_qualified_type (result_type,
438 (cp_type_quals (pointee1)
439 | cp_type_quals (pointee2)));
440 /* If the original types were pointers to members, so is the
442 if (TYPE_PTR_TO_MEMBER_P (t1))
444 if (!same_type_p (TYPE_PTRMEM_CLASS_TYPE (t1),
445 TYPE_PTRMEM_CLASS_TYPE (t2)))
446 pedwarn ("%s between distinct pointer types %qT and %qT "
449 result_type = build_ptrmem_type (TYPE_PTRMEM_CLASS_TYPE (t1),
453 result_type = build_pointer_type (result_type);
455 /* Merge the attributes. */
456 attributes = (*targetm.merge_type_attributes) (t1, t2);
457 return build_type_attribute_variant (result_type, attributes);
460 /* Return the composite pointer type (see [expr.rel]) for T1 and T2.
461 ARG1 and ARG2 are the values with those types. The LOCATION is a
462 string describing the current location, in case an error occurs.
464 This routine also implements the computation of a common type for
465 pointers-to-members as per [expr.eq]. */
468 composite_pointer_type (tree t1, tree t2, tree arg1, tree arg2,
469 const char* location)
476 If one operand is a null pointer constant, the composite pointer
477 type is the type of the other operand. */
478 if (null_ptr_cst_p (arg1))
480 if (null_ptr_cst_p (arg2))
487 If one of the operands has type "pointer to cv1 void*", then
488 the other has type "pointer to cv2T", and the composite pointer
489 type is "pointer to cv12 void", where cv12 is the union of cv1
492 If either type is a pointer to void, make sure it is T1. */
493 if (TREE_CODE (t2) == POINTER_TYPE && VOID_TYPE_P (TREE_TYPE (t2)))
501 /* Now, if T1 is a pointer to void, merge the qualifiers. */
502 if (TREE_CODE (t1) == POINTER_TYPE && VOID_TYPE_P (TREE_TYPE (t1)))
507 if (pedantic && TYPE_PTRFN_P (t2))
508 pedwarn ("ISO C++ forbids %s between pointer of type %<void *%> "
509 "and pointer-to-function", location);
511 = cp_build_qualified_type (void_type_node,
512 (cp_type_quals (TREE_TYPE (t1))
513 | cp_type_quals (TREE_TYPE (t2))));
514 result_type = build_pointer_type (result_type);
515 /* Merge the attributes. */
516 attributes = (*targetm.merge_type_attributes) (t1, t2);
517 return build_type_attribute_variant (result_type, attributes);
520 if (c_dialect_objc () && TREE_CODE (t1) == POINTER_TYPE
521 && TREE_CODE (t2) == POINTER_TYPE)
523 if (objc_compare_types (t1, t2, -3, NULL_TREE))
527 /* [expr.eq] permits the application of a pointer conversion to
528 bring the pointers to a common type. */
529 if (TREE_CODE (t1) == POINTER_TYPE && TREE_CODE (t2) == POINTER_TYPE
530 && CLASS_TYPE_P (TREE_TYPE (t1))
531 && CLASS_TYPE_P (TREE_TYPE (t2))
532 && !same_type_ignoring_top_level_qualifiers_p (TREE_TYPE (t1),
535 class1 = TREE_TYPE (t1);
536 class2 = TREE_TYPE (t2);
538 if (DERIVED_FROM_P (class1, class2))
539 t2 = (build_pointer_type
540 (cp_build_qualified_type (class1, TYPE_QUALS (class2))));
541 else if (DERIVED_FROM_P (class2, class1))
542 t1 = (build_pointer_type
543 (cp_build_qualified_type (class2, TYPE_QUALS (class1))));
546 error ("%s between distinct pointer types %qT and %qT "
547 "lacks a cast", location, t1, t2);
548 return error_mark_node;
551 /* [expr.eq] permits the application of a pointer-to-member
552 conversion to change the class type of one of the types. */
553 else if (TYPE_PTR_TO_MEMBER_P (t1)
554 && !same_type_p (TYPE_PTRMEM_CLASS_TYPE (t1),
555 TYPE_PTRMEM_CLASS_TYPE (t2)))
557 class1 = TYPE_PTRMEM_CLASS_TYPE (t1);
558 class2 = TYPE_PTRMEM_CLASS_TYPE (t2);
560 if (DERIVED_FROM_P (class1, class2))
561 t1 = build_ptrmem_type (class2, TYPE_PTRMEM_POINTED_TO_TYPE (t1));
562 else if (DERIVED_FROM_P (class2, class1))
563 t2 = build_ptrmem_type (class1, TYPE_PTRMEM_POINTED_TO_TYPE (t2));
566 error ("%s between distinct pointer-to-member types %qT and %qT "
567 "lacks a cast", location, t1, t2);
568 return error_mark_node;
572 return composite_pointer_type_r (t1, t2, location);
575 /* Return the merged type of two types.
576 We assume that comptypes has already been done and returned 1;
577 if that isn't so, this may crash.
579 This just combines attributes and default arguments; any other
580 differences would cause the two types to compare unalike. */
583 merge_types (tree t1, tree t2)
585 enum tree_code code1;
586 enum tree_code code2;
589 /* Save time if the two types are the same. */
592 if (original_type (t1) == original_type (t2))
595 /* If one type is nonsense, use the other. */
596 if (t1 == error_mark_node)
598 if (t2 == error_mark_node)
601 /* Merge the attributes. */
602 attributes = (*targetm.merge_type_attributes) (t1, t2);
604 if (TYPE_PTRMEMFUNC_P (t1))
605 t1 = TYPE_PTRMEMFUNC_FN_TYPE (t1);
606 if (TYPE_PTRMEMFUNC_P (t2))
607 t2 = TYPE_PTRMEMFUNC_FN_TYPE (t2);
609 code1 = TREE_CODE (t1);
610 code2 = TREE_CODE (t2);
616 /* For two pointers, do this recursively on the target type. */
618 tree target = merge_types (TREE_TYPE (t1), TREE_TYPE (t2));
619 int quals = cp_type_quals (t1);
621 if (code1 == POINTER_TYPE)
622 t1 = build_pointer_type (target);
624 t1 = build_reference_type (target);
625 t1 = build_type_attribute_variant (t1, attributes);
626 t1 = cp_build_qualified_type (t1, quals);
628 if (TREE_CODE (target) == METHOD_TYPE)
629 t1 = build_ptrmemfunc_type (t1);
638 quals = cp_type_quals (t1);
639 pointee = merge_types (TYPE_PTRMEM_POINTED_TO_TYPE (t1),
640 TYPE_PTRMEM_POINTED_TO_TYPE (t2));
641 t1 = build_ptrmem_type (TYPE_PTRMEM_CLASS_TYPE (t1),
643 t1 = cp_build_qualified_type (t1, quals);
649 tree elt = merge_types (TREE_TYPE (t1), TREE_TYPE (t2));
650 /* Save space: see if the result is identical to one of the args. */
651 if (elt == TREE_TYPE (t1) && TYPE_DOMAIN (t1))
652 return build_type_attribute_variant (t1, attributes);
653 if (elt == TREE_TYPE (t2) && TYPE_DOMAIN (t2))
654 return build_type_attribute_variant (t2, attributes);
655 /* Merge the element types, and have a size if either arg has one. */
656 t1 = build_cplus_array_type
657 (elt, TYPE_DOMAIN (TYPE_DOMAIN (t1) ? t1 : t2));
662 /* Function types: prefer the one that specified arg types.
663 If both do, merge the arg types. Also merge the return types. */
665 tree valtype = merge_types (TREE_TYPE (t1), TREE_TYPE (t2));
666 tree p1 = TYPE_ARG_TYPES (t1);
667 tree p2 = TYPE_ARG_TYPES (t2);
670 /* Save space: see if the result is identical to one of the args. */
671 if (valtype == TREE_TYPE (t1) && ! p2)
672 return cp_build_type_attribute_variant (t1, attributes);
673 if (valtype == TREE_TYPE (t2) && ! p1)
674 return cp_build_type_attribute_variant (t2, attributes);
676 /* Simple way if one arg fails to specify argument types. */
677 if (p1 == NULL_TREE || TREE_VALUE (p1) == void_type_node)
679 rval = build_function_type (valtype, p2);
680 if ((raises = TYPE_RAISES_EXCEPTIONS (t2)))
681 rval = build_exception_variant (rval, raises);
682 return cp_build_type_attribute_variant (rval, attributes);
684 raises = TYPE_RAISES_EXCEPTIONS (t1);
685 if (p2 == NULL_TREE || TREE_VALUE (p2) == void_type_node)
687 rval = build_function_type (valtype, p1);
689 rval = build_exception_variant (rval, raises);
690 return cp_build_type_attribute_variant (rval, attributes);
693 rval = build_function_type (valtype, commonparms (p1, p2));
694 t1 = build_exception_variant (rval, raises);
700 /* Get this value the long way, since TYPE_METHOD_BASETYPE
701 is just the main variant of this. */
702 tree basetype = TREE_TYPE (TREE_VALUE (TYPE_ARG_TYPES (t2)));
703 tree raises = TYPE_RAISES_EXCEPTIONS (t1);
706 /* If this was a member function type, get back to the
707 original type of type member function (i.e., without
708 the class instance variable up front. */
709 t1 = build_function_type (TREE_TYPE (t1),
710 TREE_CHAIN (TYPE_ARG_TYPES (t1)));
711 t2 = build_function_type (TREE_TYPE (t2),
712 TREE_CHAIN (TYPE_ARG_TYPES (t2)));
713 t3 = merge_types (t1, t2);
714 t3 = build_method_type_directly (basetype, TREE_TYPE (t3),
715 TYPE_ARG_TYPES (t3));
716 t1 = build_exception_variant (t3, raises);
721 /* There is no need to merge attributes into a TYPENAME_TYPE.
722 When the type is instantiated it will have whatever
723 attributes result from the instantiation. */
729 if (attribute_list_equal (TYPE_ATTRIBUTES (t1), attributes))
731 else if (attribute_list_equal (TYPE_ATTRIBUTES (t2), attributes))
734 return cp_build_type_attribute_variant (t1, attributes);
737 /* Return the common type of two types.
738 We assume that comptypes has already been done and returned 1;
739 if that isn't so, this may crash.
741 This is the type for the result of most arithmetic operations
742 if the operands have the given two types. */
745 common_type (tree t1, tree t2)
747 enum tree_code code1;
748 enum tree_code code2;
750 /* If one type is nonsense, bail. */
751 if (t1 == error_mark_node || t2 == error_mark_node)
752 return error_mark_node;
754 code1 = TREE_CODE (t1);
755 code2 = TREE_CODE (t2);
757 if ((ARITHMETIC_TYPE_P (t1) || code1 == ENUMERAL_TYPE
758 || code1 == VECTOR_TYPE)
759 && (ARITHMETIC_TYPE_P (t2) || code2 == ENUMERAL_TYPE
760 || code2 == VECTOR_TYPE))
761 return type_after_usual_arithmetic_conversions (t1, t2);
763 else if ((TYPE_PTR_P (t1) && TYPE_PTR_P (t2))
764 || (TYPE_PTRMEM_P (t1) && TYPE_PTRMEM_P (t2))
765 || (TYPE_PTRMEMFUNC_P (t1) && TYPE_PTRMEMFUNC_P (t2)))
766 return composite_pointer_type (t1, t2, error_mark_node, error_mark_node,
772 /* Compare two exception specifier types for exactness or subsetness, if
773 allowed. Returns false for mismatch, true for match (same, or
776 [except.spec] "If a class X ... objects of class X or any class publicly
777 and unambiguously derived from X. Similarly, if a pointer type Y * ...
778 exceptions of type Y * or that are pointers to any type publicly and
779 unambiguously derived from Y. Otherwise a function only allows exceptions
780 that have the same type ..."
781 This does not mention cv qualifiers and is different to what throw
782 [except.throw] and catch [except.catch] will do. They will ignore the
783 top level cv qualifiers, and allow qualifiers in the pointer to class
786 We implement the letter of the standard. */
789 comp_except_types (tree a, tree b, bool exact)
791 if (same_type_p (a, b))
795 if (cp_type_quals (a) || cp_type_quals (b))
798 if (TREE_CODE (a) == POINTER_TYPE
799 && TREE_CODE (b) == POINTER_TYPE)
803 if (cp_type_quals (a) || cp_type_quals (b))
807 if (TREE_CODE (a) != RECORD_TYPE
808 || TREE_CODE (b) != RECORD_TYPE)
811 if (PUBLICLY_UNIQUELY_DERIVED_P (a, b))
817 /* Return true if TYPE1 and TYPE2 are equivalent exception specifiers.
818 If EXACT is false, T2 can be stricter than T1 (according to 15.4/7),
819 otherwise it must be exact. Exception lists are unordered, but
820 we've already filtered out duplicates. Most lists will be in order,
821 we should try to make use of that. */
824 comp_except_specs (tree t1, tree t2, bool exact)
833 if (t1 == NULL_TREE) /* T1 is ... */
834 return t2 == NULL_TREE || !exact;
835 if (!TREE_VALUE (t1)) /* t1 is EMPTY */
836 return t2 != NULL_TREE && !TREE_VALUE (t2);
837 if (t2 == NULL_TREE) /* T2 is ... */
839 if (TREE_VALUE (t1) && !TREE_VALUE (t2)) /* T2 is EMPTY, T1 is not */
842 /* Neither set is ... or EMPTY, make sure each part of T2 is in T1.
843 Count how many we find, to determine exactness. For exact matching and
844 ordered T1, T2, this is an O(n) operation, otherwise its worst case is
846 for (base = t1; t2 != NULL_TREE; t2 = TREE_CHAIN (t2))
848 for (probe = base; probe != NULL_TREE; probe = TREE_CHAIN (probe))
850 tree a = TREE_VALUE (probe);
851 tree b = TREE_VALUE (t2);
853 if (comp_except_types (a, b, exact))
855 if (probe == base && exact)
856 base = TREE_CHAIN (probe);
861 if (probe == NULL_TREE)
864 return !exact || base == NULL_TREE || length == list_length (t1);
867 /* Compare the array types T1 and T2. ALLOW_REDECLARATION is true if
868 [] can match [size]. */
871 comp_array_types (tree t1, tree t2, bool allow_redeclaration)
880 /* The type of the array elements must be the same. */
881 if (!same_type_p (TREE_TYPE (t1), TREE_TYPE (t2)))
884 d1 = TYPE_DOMAIN (t1);
885 d2 = TYPE_DOMAIN (t2);
890 /* If one of the arrays is dimensionless, and the other has a
891 dimension, they are of different types. However, it is valid to
899 declarations for an array object can specify
900 array types that differ by the presence or absence of a major
901 array bound (_dcl.array_). */
903 return allow_redeclaration;
905 /* Check that the dimensions are the same. */
907 if (!cp_tree_equal (TYPE_MIN_VALUE (d1), TYPE_MIN_VALUE (d2)))
909 max1 = TYPE_MAX_VALUE (d1);
910 max2 = TYPE_MAX_VALUE (d2);
911 if (processing_template_decl && !abi_version_at_least (2)
912 && !value_dependent_expression_p (max1)
913 && !value_dependent_expression_p (max2))
915 /* With abi-1 we do not fold non-dependent array bounds, (and
916 consequently mangle them incorrectly). We must therefore
917 fold them here, to verify the domains have the same
923 if (!cp_tree_equal (max1, max2))
929 /* Subroutine in comptypes. */
932 structural_comptypes (tree t1, tree t2, int strict)
937 /* Suppress errors caused by previously reported errors. */
938 if (t1 == error_mark_node || t2 == error_mark_node)
941 gcc_assert (TYPE_P (t1) && TYPE_P (t2));
943 /* TYPENAME_TYPEs should be resolved if the qualifying scope is the
944 current instantiation. */
945 if (TREE_CODE (t1) == TYPENAME_TYPE)
947 tree resolved = resolve_typename_type (t1, /*only_current_p=*/true);
949 if (resolved != error_mark_node)
953 if (TREE_CODE (t2) == TYPENAME_TYPE)
955 tree resolved = resolve_typename_type (t2, /*only_current_p=*/true);
957 if (resolved != error_mark_node)
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))
989 case TEMPLATE_TEMPLATE_PARM:
990 case BOUND_TEMPLATE_TEMPLATE_PARM:
991 if (TEMPLATE_TYPE_IDX (t1) != TEMPLATE_TYPE_IDX (t2)
992 || TEMPLATE_TYPE_LEVEL (t1) != TEMPLATE_TYPE_LEVEL (t2)
993 || (TEMPLATE_TYPE_PARAMETER_PACK (t1)
994 != TEMPLATE_TYPE_PARAMETER_PACK (t2)))
996 if (!comp_template_parms
997 (DECL_TEMPLATE_PARMS (TEMPLATE_TEMPLATE_PARM_TEMPLATE_DECL (t1)),
998 DECL_TEMPLATE_PARMS (TEMPLATE_TEMPLATE_PARM_TEMPLATE_DECL (t2))))
1000 if (TREE_CODE (t1) == TEMPLATE_TEMPLATE_PARM)
1002 /* Don't check inheritance. */
1003 strict = COMPARE_STRICT;
1008 if (TYPE_TEMPLATE_INFO (t1) && TYPE_TEMPLATE_INFO (t2)
1009 && (TYPE_TI_TEMPLATE (t1) == TYPE_TI_TEMPLATE (t2)
1010 || TREE_CODE (t1) == BOUND_TEMPLATE_TEMPLATE_PARM)
1011 && comp_template_args (TYPE_TI_ARGS (t1), TYPE_TI_ARGS (t2)))
1014 if ((strict & COMPARE_BASE) && DERIVED_FROM_P (t1, t2))
1016 else if ((strict & COMPARE_DERIVED) && DERIVED_FROM_P (t2, t1))
1022 if (!comptypes (TYPE_OFFSET_BASETYPE (t1), TYPE_OFFSET_BASETYPE (t2),
1023 strict & ~COMPARE_REDECLARATION))
1025 if (!same_type_p (TREE_TYPE (t1), TREE_TYPE (t2)))
1030 case REFERENCE_TYPE:
1031 if (TYPE_MODE (t1) != TYPE_MODE (t2)
1032 || TYPE_REF_CAN_ALIAS_ALL (t1) != TYPE_REF_CAN_ALIAS_ALL (t2)
1033 || !same_type_p (TREE_TYPE (t1), TREE_TYPE (t2)))
1039 if (!same_type_p (TREE_TYPE (t1), TREE_TYPE (t2)))
1041 if (!compparms (TYPE_ARG_TYPES (t1), TYPE_ARG_TYPES (t2)))
1046 /* Target types must match incl. qualifiers. */
1047 if (!comp_array_types (t1, t2, !!(strict & COMPARE_REDECLARATION)))
1051 case TEMPLATE_TYPE_PARM:
1052 if (TEMPLATE_TYPE_IDX (t1) != TEMPLATE_TYPE_IDX (t2)
1053 || TEMPLATE_TYPE_LEVEL (t1) != TEMPLATE_TYPE_LEVEL (t2)
1054 || (TEMPLATE_TYPE_PARAMETER_PACK (t1)
1055 != TEMPLATE_TYPE_PARAMETER_PACK (t2)))
1060 if (!cp_tree_equal (TYPENAME_TYPE_FULLNAME (t1),
1061 TYPENAME_TYPE_FULLNAME (t2)))
1063 if (!same_type_p (TYPE_CONTEXT (t1), TYPE_CONTEXT (t2)))
1067 case UNBOUND_CLASS_TEMPLATE:
1068 if (!cp_tree_equal (TYPE_IDENTIFIER (t1), TYPE_IDENTIFIER (t2)))
1070 if (!same_type_p (TYPE_CONTEXT (t1), TYPE_CONTEXT (t2)))
1075 if (!same_type_p (TREE_TYPE (t1), TREE_TYPE (t2)))
1080 if (TYPE_VECTOR_SUBPARTS (t1) != TYPE_VECTOR_SUBPARTS (t2)
1081 || !same_type_p (TREE_TYPE (t1), TREE_TYPE (t2)))
1085 case TYPE_PACK_EXPANSION:
1086 return same_type_p (PACK_EXPANSION_PATTERN (t1),
1087 PACK_EXPANSION_PATTERN (t2));
1093 /* If we get here, we know that from a target independent POV the
1094 types are the same. Make sure the target attributes are also
1096 return targetm.comp_type_attributes (t1, t2);
1099 /* Return true if T1 and T2 are related as allowed by STRICT. STRICT
1100 is a bitwise-or of the COMPARE_* flags. */
1103 comptypes (tree t1, tree t2, int strict)
1105 if (strict == COMPARE_STRICT)
1112 if (t1 == error_mark_node || t2 == error_mark_node)
1115 if (TYPE_STRUCTURAL_EQUALITY_P (t1) || TYPE_STRUCTURAL_EQUALITY_P (t2))
1116 /* At least one of the types requires structural equality, so
1117 perform a deep check. */
1118 return structural_comptypes (t1, t2, strict);
1120 if (VERIFY_CANONICAL_TYPES)
1122 result = structural_comptypes (t1, t2, strict);
1124 if (result && TYPE_CANONICAL (t1) != TYPE_CANONICAL (t2))
1126 /* The two types are structurally equivalent, but their
1127 canonical types were different. This is a failure of the
1128 canonical type propagation code.*/
1130 "canonical types differ for identical types %T and %T",
1135 else if (!result && TYPE_CANONICAL (t1) == TYPE_CANONICAL (t2))
1137 /* Two types are structurally different, but the canonical
1138 types are the same. This means we were over-eager in
1139 assigning canonical types. */
1141 "same canonical type node for different types %T and %T",
1150 return TYPE_CANONICAL (t1) == TYPE_CANONICAL (t2);
1152 else if (strict == COMPARE_STRUCTURAL)
1153 return structural_comptypes (t1, t2, COMPARE_STRICT);
1155 return structural_comptypes (t1, t2, strict);
1158 /* Returns 1 if TYPE1 is at least as qualified as TYPE2. */
1161 at_least_as_qualified_p (tree type1, tree type2)
1163 int q1 = cp_type_quals (type1);
1164 int q2 = cp_type_quals (type2);
1166 /* All qualifiers for TYPE2 must also appear in TYPE1. */
1167 return (q1 & q2) == q2;
1170 /* Returns 1 if TYPE1 is more cv-qualified than TYPE2, -1 if TYPE2 is
1171 more cv-qualified that TYPE1, and 0 otherwise. */
1174 comp_cv_qualification (tree type1, tree type2)
1176 int q1 = cp_type_quals (type1);
1177 int q2 = cp_type_quals (type2);
1182 if ((q1 & q2) == q2)
1184 else if ((q1 & q2) == q1)
1190 /* Returns 1 if the cv-qualification signature of TYPE1 is a proper
1191 subset of the cv-qualification signature of TYPE2, and the types
1192 are similar. Returns -1 if the other way 'round, and 0 otherwise. */
1195 comp_cv_qual_signature (tree type1, tree type2)
1197 if (comp_ptr_ttypes_real (type2, type1, -1))
1199 else if (comp_ptr_ttypes_real (type1, type2, -1))
1205 /* Subroutines of `comptypes'. */
1207 /* Return true if two parameter type lists PARMS1 and PARMS2 are
1208 equivalent in the sense that functions with those parameter types
1209 can have equivalent types. The two lists must be equivalent,
1210 element by element. */
1213 compparms (tree parms1, tree parms2)
1217 /* An unspecified parmlist matches any specified parmlist
1218 whose argument types don't need default promotions. */
1220 for (t1 = parms1, t2 = parms2;
1222 t1 = TREE_CHAIN (t1), t2 = TREE_CHAIN (t2))
1224 /* If one parmlist is shorter than the other,
1225 they fail to match. */
1228 if (!same_type_p (TREE_VALUE (t1), TREE_VALUE (t2)))
1235 /* Process a sizeof or alignof expression where the operand is a
1239 cxx_sizeof_or_alignof_type (tree type, enum tree_code op, bool complain)
1244 gcc_assert (op == SIZEOF_EXPR || op == ALIGNOF_EXPR);
1245 if (type == error_mark_node)
1246 return error_mark_node;
1248 type = non_reference (type);
1249 if (TREE_CODE (type) == METHOD_TYPE)
1251 if (complain && (pedantic || warn_pointer_arith))
1252 pedwarn ("invalid application of %qs to a member function",
1253 operator_name_info[(int) op].name);
1254 value = size_one_node;
1257 dependent_p = dependent_type_p (type);
1259 complete_type (type);
1261 /* VLA types will have a non-constant size. In the body of an
1262 uninstantiated template, we don't need to try to compute the
1263 value, because the sizeof expression is not an integral
1264 constant expression in that case. And, if we do try to
1265 compute the value, we'll likely end up with SAVE_EXPRs, which
1266 the template substitution machinery does not expect to see. */
1267 || (processing_template_decl
1268 && COMPLETE_TYPE_P (type)
1269 && TREE_CODE (TYPE_SIZE (type)) != INTEGER_CST))
1271 value = build_min (op, size_type_node, type);
1272 TREE_READONLY (value) = 1;
1276 return c_sizeof_or_alignof_type (complete_type (type),
1281 /* Process a sizeof expression where the operand is an expression. */
1284 cxx_sizeof_expr (tree e)
1286 if (e == error_mark_node)
1287 return error_mark_node;
1289 if (processing_template_decl)
1291 e = build_min (SIZEOF_EXPR, size_type_node, e);
1292 TREE_SIDE_EFFECTS (e) = 0;
1293 TREE_READONLY (e) = 1;
1298 if (TREE_CODE (e) == COMPONENT_REF
1299 && TREE_CODE (TREE_OPERAND (e, 1)) == FIELD_DECL
1300 && DECL_C_BIT_FIELD (TREE_OPERAND (e, 1)))
1302 error ("invalid application of %<sizeof%> to a bit-field");
1305 else if (is_overloaded_fn (e))
1307 pedwarn ("ISO C++ forbids applying %<sizeof%> to an expression of "
1311 else if (type_unknown_p (e))
1313 cxx_incomplete_type_error (e, TREE_TYPE (e));
1319 return cxx_sizeof_or_alignof_type (e, SIZEOF_EXPR, true);
1322 /* Implement the __alignof keyword: Return the minimum required
1323 alignment of E, measured in bytes. For VAR_DECL's and
1324 FIELD_DECL's return DECL_ALIGN (which can be set from an
1325 "aligned" __attribute__ specification). */
1328 cxx_alignof_expr (tree e)
1332 if (e == error_mark_node)
1333 return error_mark_node;
1335 if (processing_template_decl)
1337 e = build_min (ALIGNOF_EXPR, size_type_node, e);
1338 TREE_SIDE_EFFECTS (e) = 0;
1339 TREE_READONLY (e) = 1;
1344 if (TREE_CODE (e) == VAR_DECL)
1345 t = size_int (DECL_ALIGN_UNIT (e));
1346 else if (TREE_CODE (e) == COMPONENT_REF
1347 && TREE_CODE (TREE_OPERAND (e, 1)) == FIELD_DECL
1348 && DECL_C_BIT_FIELD (TREE_OPERAND (e, 1)))
1350 error ("invalid application of %<__alignof%> to a bit-field");
1353 else if (TREE_CODE (e) == COMPONENT_REF
1354 && TREE_CODE (TREE_OPERAND (e, 1)) == FIELD_DECL)
1355 t = size_int (DECL_ALIGN_UNIT (TREE_OPERAND (e, 1)));
1356 else if (is_overloaded_fn (e))
1358 pedwarn ("ISO C++ forbids applying %<__alignof%> to an expression of "
1362 else if (type_unknown_p (e))
1364 cxx_incomplete_type_error (e, TREE_TYPE (e));
1368 return cxx_sizeof_or_alignof_type (TREE_TYPE (e), ALIGNOF_EXPR, true);
1370 return fold_convert (size_type_node, t);
1373 /* Process a sizeof or alignof expression E with code OP where the operand
1374 is an expression. */
1377 cxx_sizeof_or_alignof_expr (tree e, enum tree_code op)
1379 if (op == SIZEOF_EXPR)
1380 return cxx_sizeof_expr (e);
1382 return cxx_alignof_expr (e);
1385 /* EXPR is being used in a context that is not a function call.
1390 The expression can be used only as the left-hand operand of a
1391 member function call.
1393 [expr.mptr.operator]
1395 If the result of .* or ->* is a function, then that result can be
1396 used only as the operand for the function call operator ().
1398 by issuing an error message if appropriate. Returns true iff EXPR
1399 violates these rules. */
1402 invalid_nonstatic_memfn_p (tree expr)
1404 if (TREE_CODE (TREE_TYPE (expr)) == METHOD_TYPE)
1406 error ("invalid use of non-static member function");
1412 /* If EXP is a reference to a bitfield, and the type of EXP does not
1413 match the declared type of the bitfield, return the declared type
1414 of the bitfield. Otherwise, return NULL_TREE. */
1417 is_bitfield_expr_with_lowered_type (tree exp)
1419 switch (TREE_CODE (exp))
1422 if (!is_bitfield_expr_with_lowered_type (TREE_OPERAND (exp, 1)))
1424 return is_bitfield_expr_with_lowered_type (TREE_OPERAND (exp, 2));
1427 return is_bitfield_expr_with_lowered_type (TREE_OPERAND (exp, 1));
1431 return is_bitfield_expr_with_lowered_type (TREE_OPERAND (exp, 0));
1437 field = TREE_OPERAND (exp, 1);
1438 if (TREE_CODE (field) != FIELD_DECL || !DECL_C_BIT_FIELD (field))
1440 if (same_type_ignoring_top_level_qualifiers_p
1441 (TREE_TYPE (exp), DECL_BIT_FIELD_TYPE (field)))
1443 return DECL_BIT_FIELD_TYPE (field);
1451 /* Like is_bitfield_with_lowered_type, except that if EXP is not a
1452 bitfield with a lowered type, the type of EXP is returned, rather
1456 unlowered_expr_type (tree exp)
1460 type = is_bitfield_expr_with_lowered_type (exp);
1462 type = TREE_TYPE (exp);
1467 /* Perform the conversions in [expr] that apply when an lvalue appears
1468 in an rvalue context: the lvalue-to-rvalue, array-to-pointer, and
1469 function-to-pointer conversions. In addition, manifest constants
1470 are replaced by their values, and bitfield references are converted
1471 to their declared types.
1473 Although the returned value is being used as an rvalue, this
1474 function does not wrap the returned expression in a
1475 NON_LVALUE_EXPR; the caller is expected to be mindful of the fact
1476 that the return value is no longer an lvalue. */
1479 decay_conversion (tree exp)
1482 enum tree_code code;
1484 type = TREE_TYPE (exp);
1485 if (type == error_mark_node)
1486 return error_mark_node;
1488 if (type_unknown_p (exp))
1490 cxx_incomplete_type_error (exp, TREE_TYPE (exp));
1491 return error_mark_node;
1494 exp = decl_constant_value (exp);
1495 if (error_operand_p (exp))
1496 return error_mark_node;
1498 /* build_c_cast puts on a NOP_EXPR to make the result not an lvalue.
1499 Leave such NOP_EXPRs, since RHS is being used in non-lvalue context. */
1500 code = TREE_CODE (type);
1501 if (code == VOID_TYPE)
1503 error ("void value not ignored as it ought to be");
1504 return error_mark_node;
1506 if (invalid_nonstatic_memfn_p (exp))
1507 return error_mark_node;
1508 if (code == FUNCTION_TYPE || is_overloaded_fn (exp))
1509 return build_unary_op (ADDR_EXPR, exp, 0);
1510 if (code == ARRAY_TYPE)
1515 if (TREE_CODE (exp) == INDIRECT_REF)
1516 return build_nop (build_pointer_type (TREE_TYPE (type)),
1517 TREE_OPERAND (exp, 0));
1519 if (TREE_CODE (exp) == COMPOUND_EXPR)
1521 tree op1 = decay_conversion (TREE_OPERAND (exp, 1));
1522 return build2 (COMPOUND_EXPR, TREE_TYPE (op1),
1523 TREE_OPERAND (exp, 0), op1);
1527 && ! (TREE_CODE (exp) == CONSTRUCTOR && TREE_STATIC (exp)))
1529 error ("invalid use of non-lvalue array");
1530 return error_mark_node;
1533 ptrtype = build_pointer_type (TREE_TYPE (type));
1535 if (TREE_CODE (exp) == VAR_DECL)
1537 if (!cxx_mark_addressable (exp))
1538 return error_mark_node;
1539 adr = build_nop (ptrtype, build_address (exp));
1542 /* This way is better for a COMPONENT_REF since it can
1543 simplify the offset for a component. */
1544 adr = build_unary_op (ADDR_EXPR, exp, 1);
1545 return cp_convert (ptrtype, adr);
1548 /* If a bitfield is used in a context where integral promotion
1549 applies, then the caller is expected to have used
1550 default_conversion. That function promotes bitfields correctly
1551 before calling this function. At this point, if we have a
1552 bitfield referenced, we may assume that is not subject to
1553 promotion, and that, therefore, the type of the resulting rvalue
1554 is the declared type of the bitfield. */
1555 exp = convert_bitfield_to_declared_type (exp);
1557 /* We do not call rvalue() here because we do not want to wrap EXP
1558 in a NON_LVALUE_EXPR. */
1562 Non-class rvalues always have cv-unqualified types. */
1563 type = TREE_TYPE (exp);
1564 if (!CLASS_TYPE_P (type) && cp_type_quals (type))
1565 exp = build_nop (TYPE_MAIN_VARIANT (type), exp);
1570 /* Perform prepatory conversions, as part of the "usual arithmetic
1571 conversions". In particular, as per [expr]:
1573 Whenever an lvalue expression appears as an operand of an
1574 operator that expects the rvalue for that operand, the
1575 lvalue-to-rvalue, array-to-pointer, or function-to-pointer
1576 standard conversions are applied to convert the expression to an
1579 In addition, we perform integral promotions here, as those are
1580 applied to both operands to a binary operator before determining
1581 what additional conversions should apply. */
1584 default_conversion (tree exp)
1586 /* Perform the integral promotions first so that bitfield
1587 expressions (which may promote to "int", even if the bitfield is
1588 declared "unsigned") are promoted correctly. */
1589 if (INTEGRAL_OR_ENUMERATION_TYPE_P (TREE_TYPE (exp)))
1590 exp = perform_integral_promotions (exp);
1591 /* Perform the other conversions. */
1592 exp = decay_conversion (exp);
1597 /* EXPR is an expression with an integral or enumeration type.
1598 Perform the integral promotions in [conv.prom], and return the
1602 perform_integral_promotions (tree expr)
1609 If the bitfield has an enumerated type, it is treated as any
1610 other value of that type for promotion purposes. */
1611 type = is_bitfield_expr_with_lowered_type (expr);
1612 if (!type || TREE_CODE (type) != ENUMERAL_TYPE)
1613 type = TREE_TYPE (expr);
1614 gcc_assert (INTEGRAL_OR_ENUMERATION_TYPE_P (type));
1615 promoted_type = type_promotes_to (type);
1616 if (type != promoted_type)
1617 expr = cp_convert (promoted_type, expr);
1621 /* Take the address of an inline function without setting TREE_ADDRESSABLE
1625 inline_conversion (tree exp)
1627 if (TREE_CODE (exp) == FUNCTION_DECL)
1628 exp = build1 (ADDR_EXPR, build_pointer_type (TREE_TYPE (exp)), exp);
1633 /* Returns nonzero iff exp is a STRING_CST or the result of applying
1634 decay_conversion to one. */
1637 string_conv_p (tree totype, tree exp, int warn)
1641 if (TREE_CODE (totype) != POINTER_TYPE)
1644 t = TREE_TYPE (totype);
1645 if (!same_type_p (t, char_type_node)
1646 && !same_type_p (t, wchar_type_node))
1649 if (TREE_CODE (exp) == STRING_CST)
1651 /* Make sure that we don't try to convert between char and wchar_t. */
1652 if (!same_type_p (TYPE_MAIN_VARIANT (TREE_TYPE (TREE_TYPE (exp))), t))
1657 /* Is this a string constant which has decayed to 'const char *'? */
1658 t = build_pointer_type (build_qualified_type (t, TYPE_QUAL_CONST));
1659 if (!same_type_p (TREE_TYPE (exp), t))
1662 if (TREE_CODE (exp) != ADDR_EXPR
1663 || TREE_CODE (TREE_OPERAND (exp, 0)) != STRING_CST)
1667 /* This warning is not very useful, as it complains about printf. */
1669 warning (OPT_Wwrite_strings,
1670 "deprecated conversion from string constant to %qT",
1676 /* Given a COND_EXPR, MIN_EXPR, or MAX_EXPR in T, return it in a form that we
1677 can, for example, use as an lvalue. This code used to be in
1678 unary_complex_lvalue, but we needed it to deal with `a = (d == c) ? b : c'
1679 expressions, where we're dealing with aggregates. But now it's again only
1680 called from unary_complex_lvalue. The case (in particular) that led to
1681 this was with CODE == ADDR_EXPR, since it's not an lvalue when we'd
1685 rationalize_conditional_expr (enum tree_code code, tree t)
1687 /* For MIN_EXPR or MAX_EXPR, fold-const.c has arranged things so that
1688 the first operand is always the one to be used if both operands
1689 are equal, so we know what conditional expression this used to be. */
1690 if (TREE_CODE (t) == MIN_EXPR || TREE_CODE (t) == MAX_EXPR)
1692 tree op0 = TREE_OPERAND (t, 0);
1693 tree op1 = TREE_OPERAND (t, 1);
1695 /* The following code is incorrect if either operand side-effects. */
1696 gcc_assert (!TREE_SIDE_EFFECTS (op0)
1697 && !TREE_SIDE_EFFECTS (op1));
1699 build_conditional_expr (build_x_binary_op ((TREE_CODE (t) == MIN_EXPR
1700 ? LE_EXPR : GE_EXPR),
1701 op0, TREE_CODE (op0),
1702 op1, TREE_CODE (op1),
1703 /*overloaded_p=*/NULL),
1704 build_unary_op (code, op0, 0),
1705 build_unary_op (code, op1, 0));
1709 build_conditional_expr (TREE_OPERAND (t, 0),
1710 build_unary_op (code, TREE_OPERAND (t, 1), 0),
1711 build_unary_op (code, TREE_OPERAND (t, 2), 0));
1714 /* Given the TYPE of an anonymous union field inside T, return the
1715 FIELD_DECL for the field. If not found return NULL_TREE. Because
1716 anonymous unions can nest, we must also search all anonymous unions
1717 that are directly reachable. */
1720 lookup_anon_field (tree t, tree type)
1724 for (field = TYPE_FIELDS (t); field; field = TREE_CHAIN (field))
1726 if (TREE_STATIC (field))
1728 if (TREE_CODE (field) != FIELD_DECL || DECL_ARTIFICIAL (field))
1731 /* If we find it directly, return the field. */
1732 if (DECL_NAME (field) == NULL_TREE
1733 && type == TYPE_MAIN_VARIANT (TREE_TYPE (field)))
1738 /* Otherwise, it could be nested, search harder. */
1739 if (DECL_NAME (field) == NULL_TREE
1740 && ANON_AGGR_TYPE_P (TREE_TYPE (field)))
1742 tree subfield = lookup_anon_field (TREE_TYPE (field), type);
1750 /* Build an expression representing OBJECT.MEMBER. OBJECT is an
1751 expression; MEMBER is a DECL or baselink. If ACCESS_PATH is
1752 non-NULL, it indicates the path to the base used to name MEMBER.
1753 If PRESERVE_REFERENCE is true, the expression returned will have
1754 REFERENCE_TYPE if the MEMBER does. Otherwise, the expression
1755 returned will have the type referred to by the reference.
1757 This function does not perform access control; that is either done
1758 earlier by the parser when the name of MEMBER is resolved to MEMBER
1759 itself, or later when overload resolution selects one of the
1760 functions indicated by MEMBER. */
1763 build_class_member_access_expr (tree object, tree member,
1764 tree access_path, bool preserve_reference)
1768 tree result = NULL_TREE;
1770 if (error_operand_p (object) || error_operand_p (member))
1771 return error_mark_node;
1773 gcc_assert (DECL_P (member) || BASELINK_P (member));
1777 The type of the first expression shall be "class object" (of a
1779 object_type = TREE_TYPE (object);
1780 if (!currently_open_class (object_type)
1781 && !complete_type_or_else (object_type, object))
1782 return error_mark_node;
1783 if (!CLASS_TYPE_P (object_type))
1785 error ("request for member %qD in %qE, which is of non-class type %qT",
1786 member, object, object_type);
1787 return error_mark_node;
1790 /* The standard does not seem to actually say that MEMBER must be a
1791 member of OBJECT_TYPE. However, that is clearly what is
1793 if (DECL_P (member))
1795 member_scope = DECL_CLASS_CONTEXT (member);
1797 if (TREE_DEPRECATED (member))
1798 warn_deprecated_use (member);
1801 member_scope = BINFO_TYPE (BASELINK_BINFO (member));
1802 /* If MEMBER is from an anonymous aggregate, MEMBER_SCOPE will
1803 presently be the anonymous union. Go outwards until we find a
1804 type related to OBJECT_TYPE. */
1805 while (ANON_AGGR_TYPE_P (member_scope)
1806 && !same_type_ignoring_top_level_qualifiers_p (member_scope,
1808 member_scope = TYPE_CONTEXT (member_scope);
1809 if (!member_scope || !DERIVED_FROM_P (member_scope, object_type))
1811 if (TREE_CODE (member) == FIELD_DECL)
1812 error ("invalid use of nonstatic data member %qE", member);
1814 error ("%qD is not a member of %qT", member, object_type);
1815 return error_mark_node;
1818 /* Transform `(a, b).x' into `(*(a, &b)).x', `(a ? b : c).x' into
1819 `(*(a ? &b : &c)).x', and so on. A COND_EXPR is only an lvalue
1820 in the front end; only _DECLs and _REFs are lvalues in the back end. */
1822 tree temp = unary_complex_lvalue (ADDR_EXPR, object);
1824 object = build_indirect_ref (temp, NULL);
1827 /* In [expr.ref], there is an explicit list of the valid choices for
1828 MEMBER. We check for each of those cases here. */
1829 if (TREE_CODE (member) == VAR_DECL)
1831 /* A static data member. */
1833 /* If OBJECT has side-effects, they are supposed to occur. */
1834 if (TREE_SIDE_EFFECTS (object))
1835 result = build2 (COMPOUND_EXPR, TREE_TYPE (result), object, result);
1837 else if (TREE_CODE (member) == FIELD_DECL)
1839 /* A non-static data member. */
1844 null_object_p = (TREE_CODE (object) == INDIRECT_REF
1845 && integer_zerop (TREE_OPERAND (object, 0)));
1847 /* Convert OBJECT to the type of MEMBER. */
1848 if (!same_type_p (TYPE_MAIN_VARIANT (object_type),
1849 TYPE_MAIN_VARIANT (member_scope)))
1854 binfo = lookup_base (access_path ? access_path : object_type,
1855 member_scope, ba_unique, &kind);
1856 if (binfo == error_mark_node)
1857 return error_mark_node;
1859 /* It is invalid to try to get to a virtual base of a
1860 NULL object. The most common cause is invalid use of
1862 if (null_object_p && kind == bk_via_virtual)
1864 error ("invalid access to non-static data member %qD of "
1867 error ("(perhaps the %<offsetof%> macro was used incorrectly)");
1868 return error_mark_node;
1871 /* Convert to the base. */
1872 object = build_base_path (PLUS_EXPR, object, binfo,
1874 /* If we found the base successfully then we should be able
1875 to convert to it successfully. */
1876 gcc_assert (object != error_mark_node);
1879 /* Complain about other invalid uses of offsetof, even though they will
1880 give the right answer. Note that we complain whether or not they
1881 actually used the offsetof macro, since there's no way to know at this
1882 point. So we just give a warning, instead of a pedwarn. */
1883 /* Do not produce this warning for base class field references, because
1884 we know for a fact that didn't come from offsetof. This does occur
1885 in various testsuite cases where a null object is passed where a
1886 vtable access is required. */
1887 if (null_object_p && warn_invalid_offsetof
1888 && CLASSTYPE_NON_POD_P (object_type)
1889 && !DECL_FIELD_IS_BASE (member)
1890 && !skip_evaluation)
1892 warning (0, "invalid access to non-static data member %qD of NULL object",
1894 warning (0, "(perhaps the %<offsetof%> macro was used incorrectly)");
1897 /* If MEMBER is from an anonymous aggregate, we have converted
1898 OBJECT so that it refers to the class containing the
1899 anonymous union. Generate a reference to the anonymous union
1900 itself, and recur to find MEMBER. */
1901 if (ANON_AGGR_TYPE_P (DECL_CONTEXT (member))
1902 /* When this code is called from build_field_call, the
1903 object already has the type of the anonymous union.
1904 That is because the COMPONENT_REF was already
1905 constructed, and was then disassembled before calling
1906 build_field_call. After the function-call code is
1907 cleaned up, this waste can be eliminated. */
1908 && (!same_type_ignoring_top_level_qualifiers_p
1909 (TREE_TYPE (object), DECL_CONTEXT (member))))
1911 tree anonymous_union;
1913 anonymous_union = lookup_anon_field (TREE_TYPE (object),
1914 DECL_CONTEXT (member));
1915 object = build_class_member_access_expr (object,
1917 /*access_path=*/NULL_TREE,
1918 preserve_reference);
1921 /* Compute the type of the field, as described in [expr.ref]. */
1922 type_quals = TYPE_UNQUALIFIED;
1923 member_type = TREE_TYPE (member);
1924 if (TREE_CODE (member_type) != REFERENCE_TYPE)
1926 type_quals = (cp_type_quals (member_type)
1927 | cp_type_quals (object_type));
1929 /* A field is const (volatile) if the enclosing object, or the
1930 field itself, is const (volatile). But, a mutable field is
1931 not const, even within a const object. */
1932 if (DECL_MUTABLE_P (member))
1933 type_quals &= ~TYPE_QUAL_CONST;
1934 member_type = cp_build_qualified_type (member_type, type_quals);
1937 result = build3 (COMPONENT_REF, member_type, object, member,
1939 result = fold_if_not_in_template (result);
1941 /* Mark the expression const or volatile, as appropriate. Even
1942 though we've dealt with the type above, we still have to mark the
1943 expression itself. */
1944 if (type_quals & TYPE_QUAL_CONST)
1945 TREE_READONLY (result) = 1;
1946 if (type_quals & TYPE_QUAL_VOLATILE)
1947 TREE_THIS_VOLATILE (result) = 1;
1949 else if (BASELINK_P (member))
1951 /* The member is a (possibly overloaded) member function. */
1955 /* If the MEMBER is exactly one static member function, then we
1956 know the type of the expression. Otherwise, we must wait
1957 until overload resolution has been performed. */
1958 functions = BASELINK_FUNCTIONS (member);
1959 if (TREE_CODE (functions) == FUNCTION_DECL
1960 && DECL_STATIC_FUNCTION_P (functions))
1961 type = TREE_TYPE (functions);
1963 type = unknown_type_node;
1964 /* Note that we do not convert OBJECT to the BASELINK_BINFO
1965 base. That will happen when the function is called. */
1966 result = build3 (COMPONENT_REF, type, object, member, NULL_TREE);
1968 else if (TREE_CODE (member) == CONST_DECL)
1970 /* The member is an enumerator. */
1972 /* If OBJECT has side-effects, they are supposed to occur. */
1973 if (TREE_SIDE_EFFECTS (object))
1974 result = build2 (COMPOUND_EXPR, TREE_TYPE (result),
1979 error ("invalid use of %qD", member);
1980 return error_mark_node;
1983 if (!preserve_reference)
1986 If E2 is declared to have type "reference to T", then ... the
1987 type of E1.E2 is T. */
1988 result = convert_from_reference (result);
1993 /* Return the destructor denoted by OBJECT.SCOPE::~DTOR_NAME, or, if
1994 SCOPE is NULL, by OBJECT.~DTOR_NAME. */
1997 lookup_destructor (tree object, tree scope, tree dtor_name)
1999 tree object_type = TREE_TYPE (object);
2000 tree dtor_type = TREE_OPERAND (dtor_name, 0);
2003 if (scope && !check_dtor_name (scope, dtor_type))
2005 error ("qualified type %qT does not match destructor name ~%qT",
2007 return error_mark_node;
2009 if (!DERIVED_FROM_P (dtor_type, TYPE_MAIN_VARIANT (object_type)))
2011 error ("the type being destroyed is %qT, but the destructor refers to %qT",
2012 TYPE_MAIN_VARIANT (object_type), dtor_type);
2013 return error_mark_node;
2015 expr = lookup_member (dtor_type, complete_dtor_identifier,
2016 /*protect=*/1, /*want_type=*/false);
2017 expr = (adjust_result_of_qualified_name_lookup
2018 (expr, dtor_type, object_type));
2022 /* An expression of the form "A::template B" has been resolved to
2023 DECL. Issue a diagnostic if B is not a template or template
2027 check_template_keyword (tree decl)
2029 /* The standard says:
2033 If a name prefixed by the keyword template is not a member
2034 template, the program is ill-formed.
2036 DR 228 removed the restriction that the template be a member
2039 DR 96, if accepted would add the further restriction that explicit
2040 template arguments must be provided if the template keyword is
2041 used, but, as of 2005-10-16, that DR is still in "drafting". If
2042 this DR is accepted, then the semantic checks here can be
2043 simplified, as the entity named must in fact be a template
2044 specialization, rather than, as at present, a set of overloaded
2045 functions containing at least one template function. */
2046 if (TREE_CODE (decl) != TEMPLATE_DECL
2047 && TREE_CODE (decl) != TEMPLATE_ID_EXPR)
2049 if (!is_overloaded_fn (decl))
2050 pedwarn ("%qD is not a template", decl);
2055 if (BASELINK_P (fns))
2056 fns = BASELINK_FUNCTIONS (fns);
2059 tree fn = OVL_CURRENT (fns);
2060 if (TREE_CODE (fn) == TEMPLATE_DECL
2061 || TREE_CODE (fn) == TEMPLATE_ID_EXPR)
2063 if (TREE_CODE (fn) == FUNCTION_DECL
2064 && DECL_USE_TEMPLATE (fn)
2065 && PRIMARY_TEMPLATE_P (DECL_TI_TEMPLATE (fn)))
2067 fns = OVL_NEXT (fns);
2070 pedwarn ("%qD is not a template", decl);
2075 /* This function is called by the parser to process a class member
2076 access expression of the form OBJECT.NAME. NAME is a node used by
2077 the parser to represent a name; it is not yet a DECL. It may,
2078 however, be a BASELINK where the BASELINK_FUNCTIONS is a
2079 TEMPLATE_ID_EXPR. Templates must be looked up by the parser, and
2080 there is no reason to do the lookup twice, so the parser keeps the
2081 BASELINK. TEMPLATE_P is true iff NAME was explicitly declared to
2082 be a template via the use of the "A::template B" syntax. */
2085 finish_class_member_access_expr (tree object, tree name, bool template_p)
2090 tree access_path = NULL_TREE;
2091 tree orig_object = object;
2092 tree orig_name = name;
2094 if (object == error_mark_node || name == error_mark_node)
2095 return error_mark_node;
2097 /* If OBJECT is an ObjC class instance, we must obey ObjC access rules. */
2098 if (!objc_is_public (object, name))
2099 return error_mark_node;
2101 object_type = TREE_TYPE (object);
2103 if (processing_template_decl)
2105 if (/* If OBJECT_TYPE is dependent, so is OBJECT.NAME. */
2106 dependent_type_p (object_type)
2107 /* If NAME is just an IDENTIFIER_NODE, then the expression
2109 || TREE_CODE (object) == IDENTIFIER_NODE
2110 /* If NAME is "f<args>", where either 'f' or 'args' is
2111 dependent, then the expression is dependent. */
2112 || (TREE_CODE (name) == TEMPLATE_ID_EXPR
2113 && dependent_template_id_p (TREE_OPERAND (name, 0),
2114 TREE_OPERAND (name, 1)))
2115 /* If NAME is "T::X" where "T" is dependent, then the
2116 expression is dependent. */
2117 || (TREE_CODE (name) == SCOPE_REF
2118 && TYPE_P (TREE_OPERAND (name, 0))
2119 && dependent_type_p (TREE_OPERAND (name, 0))))
2120 return build_min_nt (COMPONENT_REF, object, name, NULL_TREE);
2121 object = build_non_dependent_expr (object);
2126 The type of the first expression shall be "class object" (of a
2128 if (!currently_open_class (object_type)
2129 && !complete_type_or_else (object_type, object))
2130 return error_mark_node;
2131 if (!CLASS_TYPE_P (object_type))
2133 error ("request for member %qD in %qE, which is of non-class type %qT",
2134 name, object, object_type);
2135 return error_mark_node;
2138 if (BASELINK_P (name))
2139 /* A member function that has already been looked up. */
2143 bool is_template_id = false;
2144 tree template_args = NULL_TREE;
2147 if (TREE_CODE (name) == TEMPLATE_ID_EXPR)
2149 is_template_id = true;
2150 template_args = TREE_OPERAND (name, 1);
2151 name = TREE_OPERAND (name, 0);
2153 if (TREE_CODE (name) == OVERLOAD)
2154 name = DECL_NAME (get_first_fn (name));
2155 else if (DECL_P (name))
2156 name = DECL_NAME (name);
2159 if (TREE_CODE (name) == SCOPE_REF)
2161 /* A qualified name. The qualifying class or namespace `S'
2162 has already been looked up; it is either a TYPE or a
2164 scope = TREE_OPERAND (name, 0);
2165 name = TREE_OPERAND (name, 1);
2167 /* If SCOPE is a namespace, then the qualified name does not
2168 name a member of OBJECT_TYPE. */
2169 if (TREE_CODE (scope) == NAMESPACE_DECL)
2171 error ("%<%D::%D%> is not a member of %qT",
2172 scope, name, object_type);
2173 return error_mark_node;
2176 gcc_assert (CLASS_TYPE_P (scope));
2177 gcc_assert (TREE_CODE (name) == IDENTIFIER_NODE
2178 || TREE_CODE (name) == BIT_NOT_EXPR);
2180 /* Find the base of OBJECT_TYPE corresponding to SCOPE. */
2181 access_path = lookup_base (object_type, scope, ba_check, NULL);
2182 if (access_path == error_mark_node)
2183 return error_mark_node;
2186 error ("%qT is not a base of %qT", scope, object_type);
2187 return error_mark_node;
2193 access_path = object_type;
2196 if (TREE_CODE (name) == BIT_NOT_EXPR)
2197 member = lookup_destructor (object, scope, name);
2200 /* Look up the member. */
2201 member = lookup_member (access_path, name, /*protect=*/1,
2202 /*want_type=*/false);
2203 if (member == NULL_TREE)
2205 error ("%qD has no member named %qE", object_type, name);
2206 return error_mark_node;
2208 if (member == error_mark_node)
2209 return error_mark_node;
2214 tree template = member;
2216 if (BASELINK_P (template))
2217 template = lookup_template_function (template, template_args);
2220 error ("%qD is not a member template function", name);
2221 return error_mark_node;
2226 if (TREE_DEPRECATED (member))
2227 warn_deprecated_use (member);
2230 check_template_keyword (member);
2232 expr = build_class_member_access_expr (object, member, access_path,
2233 /*preserve_reference=*/false);
2234 if (processing_template_decl && expr != error_mark_node)
2236 if (BASELINK_P (member))
2238 if (TREE_CODE (orig_name) == SCOPE_REF)
2239 BASELINK_QUALIFIED_P (member) = 1;
2242 return build_min_non_dep (COMPONENT_REF, expr,
2243 orig_object, orig_name,
2250 /* Return an expression for the MEMBER_NAME field in the internal
2251 representation of PTRMEM, a pointer-to-member function. (Each
2252 pointer-to-member function type gets its own RECORD_TYPE so it is
2253 more convenient to access the fields by name than by FIELD_DECL.)
2254 This routine converts the NAME to a FIELD_DECL and then creates the
2255 node for the complete expression. */
2258 build_ptrmemfunc_access_expr (tree ptrmem, tree member_name)
2264 /* This code is a stripped down version of
2265 build_class_member_access_expr. It does not work to use that
2266 routine directly because it expects the object to be of class
2268 ptrmem_type = TREE_TYPE (ptrmem);
2269 gcc_assert (TYPE_PTRMEMFUNC_P (ptrmem_type));
2270 member = lookup_member (ptrmem_type, member_name, /*protect=*/0,
2271 /*want_type=*/false);
2272 member_type = cp_build_qualified_type (TREE_TYPE (member),
2273 cp_type_quals (ptrmem_type));
2274 return fold_build3 (COMPONENT_REF, member_type,
2275 ptrmem, member, NULL_TREE);
2278 /* Given an expression PTR for a pointer, return an expression
2279 for the value pointed to.
2280 ERRORSTRING is the name of the operator to appear in error messages.
2282 This function may need to overload OPERATOR_FNNAME.
2283 Must also handle REFERENCE_TYPEs for C++. */
2286 build_x_indirect_ref (tree expr, const char *errorstring)
2288 tree orig_expr = expr;
2291 if (processing_template_decl)
2293 if (type_dependent_expression_p (expr))
2294 return build_min_nt (INDIRECT_REF, expr);
2295 expr = build_non_dependent_expr (expr);
2298 rval = build_new_op (INDIRECT_REF, LOOKUP_NORMAL, expr, NULL_TREE,
2299 NULL_TREE, /*overloaded_p=*/NULL);
2301 rval = build_indirect_ref (expr, errorstring);
2303 if (processing_template_decl && rval != error_mark_node)
2304 return build_min_non_dep (INDIRECT_REF, rval, orig_expr);
2310 build_indirect_ref (tree ptr, const char *errorstring)
2314 if (ptr == error_mark_node)
2315 return error_mark_node;
2317 if (ptr == current_class_ptr)
2318 return current_class_ref;
2320 pointer = (TREE_CODE (TREE_TYPE (ptr)) == REFERENCE_TYPE
2321 ? ptr : decay_conversion (ptr));
2322 type = TREE_TYPE (pointer);
2324 if (POINTER_TYPE_P (type))
2328 If the type of the expression is "pointer to T," the type
2329 of the result is "T."
2331 We must use the canonical variant because certain parts of
2332 the back end, like fold, do pointer comparisons between
2334 tree t = canonical_type_variant (TREE_TYPE (type));
2336 if (TREE_CODE (ptr) == CONVERT_EXPR
2337 || TREE_CODE (ptr) == NOP_EXPR
2338 || TREE_CODE (ptr) == VIEW_CONVERT_EXPR)
2340 /* If a warning is issued, mark it to avoid duplicates from
2341 the backend. This only needs to be done at
2342 warn_strict_aliasing > 2. */
2343 if (warn_strict_aliasing > 2)
2344 if (strict_aliasing_warning (TREE_TYPE (TREE_OPERAND (ptr, 0)),
2345 type, TREE_OPERAND (ptr, 0)))
2346 TREE_NO_WARNING (ptr) = 1;
2349 if (VOID_TYPE_P (t))
2351 /* A pointer to incomplete type (other than cv void) can be
2352 dereferenced [expr.unary.op]/1 */
2353 error ("%qT is not a pointer-to-object type", type);
2354 return error_mark_node;
2356 else if (TREE_CODE (pointer) == ADDR_EXPR
2357 && same_type_p (t, TREE_TYPE (TREE_OPERAND (pointer, 0))))
2358 /* The POINTER was something like `&x'. We simplify `*&x' to
2360 return TREE_OPERAND (pointer, 0);
2363 tree ref = build1 (INDIRECT_REF, t, pointer);
2365 /* We *must* set TREE_READONLY when dereferencing a pointer to const,
2366 so that we get the proper error message if the result is used
2367 to assign to. Also, &* is supposed to be a no-op. */
2368 TREE_READONLY (ref) = CP_TYPE_CONST_P (t);
2369 TREE_THIS_VOLATILE (ref) = CP_TYPE_VOLATILE_P (t);
2370 TREE_SIDE_EFFECTS (ref)
2371 = (TREE_THIS_VOLATILE (ref) || TREE_SIDE_EFFECTS (pointer));
2375 /* `pointer' won't be an error_mark_node if we were given a
2376 pointer to member, so it's cool to check for this here. */
2377 else if (TYPE_PTR_TO_MEMBER_P (type))
2378 error ("invalid use of %qs on pointer to member", errorstring);
2379 else if (pointer != error_mark_node)
2382 error ("invalid type argument of %qs", errorstring);
2384 error ("invalid type argument");
2386 return error_mark_node;
2389 /* This handles expressions of the form "a[i]", which denotes
2392 This is logically equivalent in C to *(a+i), but we may do it differently.
2393 If A is a variable or a member, we generate a primitive ARRAY_REF.
2394 This avoids forcing the array out of registers, and can work on
2395 arrays that are not lvalues (for example, members of structures returned
2398 If INDEX is of some user-defined type, it must be converted to
2399 integer type. Otherwise, to make a compatible PLUS_EXPR, it
2400 will inherit the type of the array, which will be some pointer type. */
2403 build_array_ref (tree array, tree idx)
2407 error ("subscript missing in array reference");
2408 return error_mark_node;
2411 if (TREE_TYPE (array) == error_mark_node
2412 || TREE_TYPE (idx) == error_mark_node)
2413 return error_mark_node;
2415 /* If ARRAY is a COMPOUND_EXPR or COND_EXPR, move our reference
2417 switch (TREE_CODE (array))
2421 tree value = build_array_ref (TREE_OPERAND (array, 1), idx);
2422 return build2 (COMPOUND_EXPR, TREE_TYPE (value),
2423 TREE_OPERAND (array, 0), value);
2427 return build_conditional_expr
2428 (TREE_OPERAND (array, 0),
2429 build_array_ref (TREE_OPERAND (array, 1), idx),
2430 build_array_ref (TREE_OPERAND (array, 2), idx));
2436 if (TREE_CODE (TREE_TYPE (array)) == ARRAY_TYPE)
2440 warn_array_subscript_with_type_char (idx);
2442 if (!INTEGRAL_OR_ENUMERATION_TYPE_P (TREE_TYPE (idx)))
2444 error ("array subscript is not an integer");
2445 return error_mark_node;
2448 /* Apply integral promotions *after* noticing character types.
2449 (It is unclear why we do these promotions -- the standard
2450 does not say that we should. In fact, the natural thing would
2451 seem to be to convert IDX to ptrdiff_t; we're performing
2452 pointer arithmetic.) */
2453 idx = perform_integral_promotions (idx);
2455 /* An array that is indexed by a non-constant
2456 cannot be stored in a register; we must be able to do
2457 address arithmetic on its address.
2458 Likewise an array of elements of variable size. */
2459 if (TREE_CODE (idx) != INTEGER_CST
2460 || (COMPLETE_TYPE_P (TREE_TYPE (TREE_TYPE (array)))
2461 && (TREE_CODE (TYPE_SIZE (TREE_TYPE (TREE_TYPE (array))))
2464 if (!cxx_mark_addressable (array))
2465 return error_mark_node;
2468 /* An array that is indexed by a constant value which is not within
2469 the array bounds cannot be stored in a register either; because we
2470 would get a crash in store_bit_field/extract_bit_field when trying
2471 to access a non-existent part of the register. */
2472 if (TREE_CODE (idx) == INTEGER_CST
2473 && TYPE_DOMAIN (TREE_TYPE (array))
2474 && ! int_fits_type_p (idx, TYPE_DOMAIN (TREE_TYPE (array))))
2476 if (!cxx_mark_addressable (array))
2477 return error_mark_node;
2480 if (pedantic && !lvalue_p (array))
2481 pedwarn ("ISO C++ forbids subscripting non-lvalue array");
2483 /* Note in C++ it is valid to subscript a `register' array, since
2484 it is valid to take the address of something with that
2485 storage specification. */
2489 while (TREE_CODE (foo) == COMPONENT_REF)
2490 foo = TREE_OPERAND (foo, 0);
2491 if (TREE_CODE (foo) == VAR_DECL && DECL_REGISTER (foo))
2492 warning (OPT_Wextra, "subscripting array declared %<register%>");
2495 type = TREE_TYPE (TREE_TYPE (array));
2496 rval = build4 (ARRAY_REF, type, array, idx, NULL_TREE, NULL_TREE);
2497 /* Array ref is const/volatile if the array elements are
2498 or if the array is.. */
2499 TREE_READONLY (rval)
2500 |= (CP_TYPE_CONST_P (type) | TREE_READONLY (array));
2501 TREE_SIDE_EFFECTS (rval)
2502 |= (CP_TYPE_VOLATILE_P (type) | TREE_SIDE_EFFECTS (array));
2503 TREE_THIS_VOLATILE (rval)
2504 |= (CP_TYPE_VOLATILE_P (type) | TREE_THIS_VOLATILE (array));
2505 return require_complete_type (fold_if_not_in_template (rval));
2509 tree ar = default_conversion (array);
2510 tree ind = default_conversion (idx);
2512 /* Put the integer in IND to simplify error checking. */
2513 if (TREE_CODE (TREE_TYPE (ar)) == INTEGER_TYPE)
2520 if (ar == error_mark_node)
2523 if (TREE_CODE (TREE_TYPE (ar)) != POINTER_TYPE)
2525 error ("subscripted value is neither array nor pointer");
2526 return error_mark_node;
2528 if (TREE_CODE (TREE_TYPE (ind)) != INTEGER_TYPE)
2530 error ("array subscript is not an integer");
2531 return error_mark_node;
2534 warn_array_subscript_with_type_char (idx);
2536 return build_indirect_ref (cp_build_binary_op (PLUS_EXPR, ar, ind),
2541 /* Resolve a pointer to member function. INSTANCE is the object
2542 instance to use, if the member points to a virtual member.
2544 This used to avoid checking for virtual functions if basetype
2545 has no virtual functions, according to an earlier ANSI draft.
2546 With the final ISO C++ rules, such an optimization is
2547 incorrect: A pointer to a derived member can be static_cast
2548 to pointer-to-base-member, as long as the dynamic object
2549 later has the right member. */
2552 get_member_function_from_ptrfunc (tree *instance_ptrptr, tree function)
2554 if (TREE_CODE (function) == OFFSET_REF)
2555 function = TREE_OPERAND (function, 1);
2557 if (TYPE_PTRMEMFUNC_P (TREE_TYPE (function)))
2559 tree idx, delta, e1, e2, e3, vtbl, basetype;
2560 tree fntype = TYPE_PTRMEMFUNC_FN_TYPE (TREE_TYPE (function));
2562 tree instance_ptr = *instance_ptrptr;
2563 tree instance_save_expr = 0;
2564 if (instance_ptr == error_mark_node)
2566 if (TREE_CODE (function) == PTRMEM_CST)
2568 /* Extracting the function address from a pmf is only
2569 allowed with -Wno-pmf-conversions. It only works for
2571 e1 = build_addr_func (PTRMEM_CST_MEMBER (function));
2572 e1 = convert (fntype, e1);
2577 error ("object missing in use of %qE", function);
2578 return error_mark_node;
2582 if (TREE_SIDE_EFFECTS (instance_ptr))
2583 instance_ptr = instance_save_expr = save_expr (instance_ptr);
2585 if (TREE_SIDE_EFFECTS (function))
2586 function = save_expr (function);
2588 /* Start by extracting all the information from the PMF itself. */
2589 e3 = pfn_from_ptrmemfunc (function);
2590 delta = build_ptrmemfunc_access_expr (function, delta_identifier);
2591 idx = build1 (NOP_EXPR, vtable_index_type, e3);
2592 switch (TARGET_PTRMEMFUNC_VBIT_LOCATION)
2594 case ptrmemfunc_vbit_in_pfn:
2595 e1 = cp_build_binary_op (BIT_AND_EXPR, idx, integer_one_node);
2596 idx = cp_build_binary_op (MINUS_EXPR, idx, integer_one_node);
2599 case ptrmemfunc_vbit_in_delta:
2600 e1 = cp_build_binary_op (BIT_AND_EXPR, delta, integer_one_node);
2601 delta = cp_build_binary_op (RSHIFT_EXPR, delta, integer_one_node);
2608 /* Convert down to the right base before using the instance. A
2609 special case is that in a pointer to member of class C, C may
2610 be incomplete. In that case, the function will of course be
2611 a member of C, and no conversion is required. In fact,
2612 lookup_base will fail in that case, because incomplete
2613 classes do not have BINFOs. */
2614 basetype = TYPE_METHOD_BASETYPE (TREE_TYPE (fntype));
2615 if (!same_type_ignoring_top_level_qualifiers_p
2616 (basetype, TREE_TYPE (TREE_TYPE (instance_ptr))))
2618 basetype = lookup_base (TREE_TYPE (TREE_TYPE (instance_ptr)),
2619 basetype, ba_check, NULL);
2620 instance_ptr = build_base_path (PLUS_EXPR, instance_ptr, basetype,
2622 if (instance_ptr == error_mark_node)
2623 return error_mark_node;
2625 /* ...and then the delta in the PMF. */
2626 instance_ptr = build2 (PLUS_EXPR, TREE_TYPE (instance_ptr),
2627 instance_ptr, delta);
2629 /* Hand back the adjusted 'this' argument to our caller. */
2630 *instance_ptrptr = instance_ptr;
2632 /* Next extract the vtable pointer from the object. */
2633 vtbl = build1 (NOP_EXPR, build_pointer_type (vtbl_ptr_type_node),
2635 vtbl = build_indirect_ref (vtbl, NULL);
2637 /* Finally, extract the function pointer from the vtable. */
2638 e2 = fold_build2 (PLUS_EXPR, TREE_TYPE (vtbl), vtbl, idx);
2639 e2 = build_indirect_ref (e2, NULL);
2640 TREE_CONSTANT (e2) = 1;
2641 TREE_INVARIANT (e2) = 1;
2643 /* When using function descriptors, the address of the
2644 vtable entry is treated as a function pointer. */
2645 if (TARGET_VTABLE_USES_DESCRIPTORS)
2646 e2 = build1 (NOP_EXPR, TREE_TYPE (e2),
2647 build_unary_op (ADDR_EXPR, e2, /*noconvert=*/1));
2649 TREE_TYPE (e2) = TREE_TYPE (e3);
2650 e1 = build_conditional_expr (e1, e2, e3);
2652 /* Make sure this doesn't get evaluated first inside one of the
2653 branches of the COND_EXPR. */
2654 if (instance_save_expr)
2655 e1 = build2 (COMPOUND_EXPR, TREE_TYPE (e1),
2656 instance_save_expr, e1);
2664 build_function_call (tree function, tree params)
2666 tree fntype, fndecl;
2667 tree name = NULL_TREE;
2669 tree original = function;
2670 int nargs, parm_types_len;
2674 /* For Objective-C, convert any calls via a cast to OBJC_TYPE_REF
2675 expressions, like those used for ObjC messenger dispatches. */
2676 function = objc_rewrite_function_call (function, params);
2678 /* build_c_cast puts on a NOP_EXPR to make the result not an lvalue.
2679 Strip such NOP_EXPRs, since FUNCTION is used in non-lvalue context. */
2680 if (TREE_CODE (function) == NOP_EXPR
2681 && TREE_TYPE (function) == TREE_TYPE (TREE_OPERAND (function, 0)))
2682 function = TREE_OPERAND (function, 0);
2684 if (TREE_CODE (function) == FUNCTION_DECL)
2686 name = DECL_NAME (function);
2688 mark_used (function);
2691 /* Convert anything with function type to a pointer-to-function. */
2692 if (pedantic && DECL_MAIN_P (function))
2693 pedwarn ("ISO C++ forbids calling %<::main%> from within program");
2695 /* Differs from default_conversion by not setting TREE_ADDRESSABLE
2696 (because calling an inline function does not mean the function
2697 needs to be separately compiled). */
2699 if (DECL_INLINE (function))
2700 function = inline_conversion (function);
2702 function = build_addr_func (function);
2708 function = build_addr_func (function);
2711 if (function == error_mark_node)
2712 return error_mark_node;
2714 fntype = TREE_TYPE (function);
2716 if (TYPE_PTRMEMFUNC_P (fntype))
2718 error ("must use %<.*%> or %<->*%> to call pointer-to-member "
2719 "function in %<%E (...)%>",
2721 return error_mark_node;
2724 is_method = (TREE_CODE (fntype) == POINTER_TYPE
2725 && TREE_CODE (TREE_TYPE (fntype)) == METHOD_TYPE);
2727 if (!((TREE_CODE (fntype) == POINTER_TYPE
2728 && TREE_CODE (TREE_TYPE (fntype)) == FUNCTION_TYPE)
2730 || TREE_CODE (function) == TEMPLATE_ID_EXPR))
2732 error ("%qE cannot be used as a function", original);
2733 return error_mark_node;
2736 /* fntype now gets the type of function pointed to. */
2737 fntype = TREE_TYPE (fntype);
2738 parm_types = TYPE_ARG_TYPES (fntype);
2740 /* Allocate storage for converted arguments. */
2741 parm_types_len = list_length (parm_types);
2742 nargs = list_length (params);
2743 if (parm_types_len > nargs)
2744 nargs = parm_types_len;
2745 argarray = (tree *) alloca (nargs * sizeof (tree));
2747 /* Convert the parameters to the types declared in the
2748 function prototype, or apply default promotions. */
2749 nargs = convert_arguments (nargs, argarray, parm_types,
2750 params, fndecl, LOOKUP_NORMAL);
2752 return error_mark_node;
2754 /* Check for errors in format strings and inappropriately
2757 check_function_arguments (TYPE_ATTRIBUTES (fntype), nargs, argarray,
2760 return build_cxx_call (function, nargs, argarray);
2763 /* Convert the actual parameter expressions in the list VALUES
2764 to the types in the list TYPELIST.
2765 If parmdecls is exhausted, or when an element has NULL as its type,
2766 perform the default conversions.
2768 Store the converted arguments in ARGARRAY. NARGS is the size of this array.
2770 NAME is an IDENTIFIER_NODE or 0. It is used only for error messages.
2772 This is also where warnings about wrong number of args are generated.
2774 Returns the actual number of arguments processed (which might be less
2775 than NARGS), or -1 on error.
2777 VALUES is a chain of TREE_LIST nodes with the elements of the list
2778 in the TREE_VALUE slots of those nodes.
2780 In C++, unspecified trailing parameters can be filled in with their
2781 default arguments, if such were specified. Do so here. */
2784 convert_arguments (int nargs, tree *argarray,
2785 tree typelist, tree values, tree fndecl, int flags)
2787 tree typetail, valtail;
2788 const char *called_thing = 0;
2791 /* Argument passing is always copy-initialization. */
2792 flags |= LOOKUP_ONLYCONVERTING;
2796 if (TREE_CODE (TREE_TYPE (fndecl)) == METHOD_TYPE)
2798 if (DECL_NAME (fndecl) == NULL_TREE
2799 || IDENTIFIER_HAS_TYPE_VALUE (DECL_NAME (fndecl)))
2800 called_thing = "constructor";
2802 called_thing = "member function";
2805 called_thing = "function";
2808 for (valtail = values, typetail = typelist;
2810 valtail = TREE_CHAIN (valtail), i++)
2812 tree type = typetail ? TREE_VALUE (typetail) : 0;
2813 tree val = TREE_VALUE (valtail);
2815 if (val == error_mark_node || type == error_mark_node)
2818 if (type == void_type_node)
2822 error ("too many arguments to %s %q+#D", called_thing, fndecl);
2823 error ("at this point in file");
2826 error ("too many arguments to function");
2830 /* build_c_cast puts on a NOP_EXPR to make the result not an lvalue.
2831 Strip such NOP_EXPRs, since VAL is used in non-lvalue context. */
2832 if (TREE_CODE (val) == NOP_EXPR
2833 && TREE_TYPE (val) == TREE_TYPE (TREE_OPERAND (val, 0))
2834 && (type == 0 || TREE_CODE (type) != REFERENCE_TYPE))
2835 val = TREE_OPERAND (val, 0);
2837 if (type == 0 || TREE_CODE (type) != REFERENCE_TYPE)
2839 if (TREE_CODE (TREE_TYPE (val)) == ARRAY_TYPE
2840 || TREE_CODE (TREE_TYPE (val)) == FUNCTION_TYPE
2841 || TREE_CODE (TREE_TYPE (val)) == METHOD_TYPE)
2842 val = decay_conversion (val);
2845 if (val == error_mark_node)
2850 /* Formal parm type is specified by a function prototype. */
2853 if (!COMPLETE_TYPE_P (complete_type (type)))
2856 error ("parameter %P of %qD has incomplete type %qT",
2859 error ("parameter %P has incomplete type %qT", i, type);
2860 parmval = error_mark_node;
2864 parmval = convert_for_initialization
2865 (NULL_TREE, type, val, flags,
2866 "argument passing", fndecl, i);
2867 parmval = convert_for_arg_passing (type, parmval);
2870 if (parmval == error_mark_node)
2873 argarray[i] = parmval;
2877 if (fndecl && DECL_BUILT_IN (fndecl)
2878 && DECL_FUNCTION_CODE (fndecl) == BUILT_IN_CONSTANT_P)
2879 /* Don't do ellipsis conversion for __built_in_constant_p
2880 as this will result in spurious warnings for non-POD
2882 val = require_complete_type (val);
2884 val = convert_arg_to_ellipsis (val);
2890 typetail = TREE_CHAIN (typetail);
2893 if (typetail != 0 && typetail != void_list_node)
2895 /* See if there are default arguments that can be used. */
2896 if (TREE_PURPOSE (typetail)
2897 && TREE_CODE (TREE_PURPOSE (typetail)) != DEFAULT_ARG)
2899 for (; typetail != void_list_node; ++i)
2902 = convert_default_arg (TREE_VALUE (typetail),
2903 TREE_PURPOSE (typetail),
2906 if (parmval == error_mark_node)
2909 argarray[i] = parmval;
2910 typetail = TREE_CHAIN (typetail);
2911 /* ends with `...'. */
2912 if (typetail == NULL_TREE)
2920 error ("too few arguments to %s %q+#D", called_thing, fndecl);
2921 error ("at this point in file");
2924 error ("too few arguments to function");
2929 gcc_assert (i <= nargs);
2933 /* Build a binary-operation expression, after performing default
2934 conversions on the operands. CODE is the kind of expression to
2935 build. ARG1 and ARG2 are the arguments. ARG1_CODE and ARG2_CODE
2936 are the tree codes which correspond to ARG1 and ARG2 when issuing
2937 warnings about possibly misplaced parentheses. They may differ
2938 from the TREE_CODE of ARG1 and ARG2 if the parser has done constant
2939 folding (e.g., if the parser sees "a | 1 + 1", it may call this
2940 routine with ARG2 being an INTEGER_CST and ARG2_CODE == PLUS_EXPR).
2941 To avoid issuing any parentheses warnings, pass ARG1_CODE and/or
2942 ARG2_CODE as ERROR_MARK. */
2945 build_x_binary_op (enum tree_code code, tree arg1, enum tree_code arg1_code,
2946 tree arg2, enum tree_code arg2_code, bool *overloaded_p)
2955 if (processing_template_decl)
2957 if (type_dependent_expression_p (arg1)
2958 || type_dependent_expression_p (arg2))
2959 return build_min_nt (code, arg1, arg2);
2960 arg1 = build_non_dependent_expr (arg1);
2961 arg2 = build_non_dependent_expr (arg2);
2964 if (code == DOTSTAR_EXPR)
2965 expr = build_m_component_ref (arg1, arg2);
2967 expr = build_new_op (code, LOOKUP_NORMAL, arg1, arg2, NULL_TREE,
2970 /* Check for cases such as x+y<<z which users are likely to
2971 misinterpret. But don't warn about obj << x + y, since that is a
2972 common idiom for I/O. */
2973 if (warn_parentheses
2974 && !processing_template_decl
2975 && !error_operand_p (arg1)
2976 && !error_operand_p (arg2)
2977 && (code != LSHIFT_EXPR
2978 || !CLASS_TYPE_P (TREE_TYPE (arg1))))
2979 warn_about_parentheses (code, arg1_code, arg2_code);
2981 if (processing_template_decl && expr != error_mark_node)
2982 return build_min_non_dep (code, expr, orig_arg1, orig_arg2);
2987 /* Build a binary-operation expression without default conversions.
2988 CODE is the kind of expression to build.
2989 This function differs from `build' in several ways:
2990 the data type of the result is computed and recorded in it,
2991 warnings are generated if arg data types are invalid,
2992 special handling for addition and subtraction of pointers is known,
2993 and some optimization is done (operations on narrow ints
2994 are done in the narrower type when that gives the same result).
2995 Constant folding is also done before the result is returned.
2997 Note that the operands will never have enumeral types
2998 because either they have just had the default conversions performed
2999 or they have both just been converted to some other type in which
3000 the arithmetic is to be done.
3002 C++: must do special pointer arithmetic when implementing
3003 multiple inheritance, and deal with pointer to member functions. */
3006 build_binary_op (enum tree_code code, tree orig_op0, tree orig_op1,
3007 int convert_p ATTRIBUTE_UNUSED)
3010 enum tree_code code0, code1;
3012 const char *invalid_op_diag;
3014 /* Expression code to give to the expression when it is built.
3015 Normally this is CODE, which is what the caller asked for,
3016 but in some special cases we change it. */
3017 enum tree_code resultcode = code;
3019 /* Data type in which the computation is to be performed.
3020 In the simplest cases this is the common type of the arguments. */
3021 tree result_type = NULL;
3023 /* Nonzero means operands have already been type-converted
3024 in whatever way is necessary.
3025 Zero means they need to be converted to RESULT_TYPE. */
3028 /* Nonzero means create the expression with this type, rather than
3030 tree build_type = 0;
3032 /* Nonzero means after finally constructing the expression
3033 convert it to this type. */
3034 tree final_type = 0;
3038 /* Nonzero if this is an operation like MIN or MAX which can
3039 safely be computed in short if both args are promoted shorts.
3040 Also implies COMMON.
3041 -1 indicates a bitwise operation; this makes a difference
3042 in the exact conditions for when it is safe to do the operation
3043 in a narrower mode. */
3046 /* Nonzero if this is a comparison operation;
3047 if both args are promoted shorts, compare the original shorts.
3048 Also implies COMMON. */
3049 int short_compare = 0;
3051 /* Nonzero if this is a right-shift operation, which can be computed on the
3052 original short and then promoted if the operand is a promoted short. */
3053 int short_shift = 0;
3055 /* Nonzero means set RESULT_TYPE to the common type of the args. */
3058 /* True if both operands have arithmetic type. */
3059 bool arithmetic_types_p;
3061 /* Apply default conversions. */
3065 if (code == TRUTH_AND_EXPR || code == TRUTH_ANDIF_EXPR
3066 || code == TRUTH_OR_EXPR || code == TRUTH_ORIF_EXPR
3067 || code == TRUTH_XOR_EXPR)
3069 if (!really_overloaded_fn (op0))
3070 op0 = decay_conversion (op0);
3071 if (!really_overloaded_fn (op1))
3072 op1 = decay_conversion (op1);
3076 if (!really_overloaded_fn (op0))
3077 op0 = default_conversion (op0);
3078 if (!really_overloaded_fn (op1))
3079 op1 = default_conversion (op1);
3082 /* Strip NON_LVALUE_EXPRs, etc., since we aren't using as an lvalue. */
3083 STRIP_TYPE_NOPS (op0);
3084 STRIP_TYPE_NOPS (op1);
3086 /* DTRT if one side is an overloaded function, but complain about it. */
3087 if (type_unknown_p (op0))
3089 tree t = instantiate_type (TREE_TYPE (op1), op0, tf_none);
3090 if (t != error_mark_node)
3092 pedwarn ("assuming cast to type %qT from overloaded function",
3097 if (type_unknown_p (op1))
3099 tree t = instantiate_type (TREE_TYPE (op0), op1, tf_none);
3100 if (t != error_mark_node)
3102 pedwarn ("assuming cast to type %qT from overloaded function",
3108 type0 = TREE_TYPE (op0);
3109 type1 = TREE_TYPE (op1);
3111 /* The expression codes of the data types of the arguments tell us
3112 whether the arguments are integers, floating, pointers, etc. */
3113 code0 = TREE_CODE (type0);
3114 code1 = TREE_CODE (type1);
3116 /* If an error was already reported for one of the arguments,
3117 avoid reporting another error. */
3119 if (code0 == ERROR_MARK || code1 == ERROR_MARK)
3120 return error_mark_node;
3122 if ((invalid_op_diag
3123 = targetm.invalid_binary_op (code, type0, type1)))
3125 error (invalid_op_diag);
3126 return error_mark_node;
3132 /* Subtraction of two similar pointers.
3133 We must subtract them as integers, then divide by object size. */
3134 if (code0 == POINTER_TYPE && code1 == POINTER_TYPE
3135 && same_type_ignoring_top_level_qualifiers_p (TREE_TYPE (type0),
3137 return pointer_diff (op0, op1, common_type (type0, type1));
3138 /* In all other cases except pointer - int, the usual arithmetic
3140 else if (!(code0 == POINTER_TYPE && code1 == INTEGER_TYPE))
3145 /* The pointer - int case is just like pointer + int; fall
3148 if ((code0 == POINTER_TYPE || code1 == POINTER_TYPE)
3149 && (code0 == INTEGER_TYPE || code1 == INTEGER_TYPE))
3153 ptr_operand = ((code0 == POINTER_TYPE) ? op0 : op1);
3154 int_operand = ((code0 == INTEGER_TYPE) ? op0 : op1);
3155 if (processing_template_decl)
3157 result_type = TREE_TYPE (ptr_operand);
3160 return cp_pointer_int_sum (code,
3171 case TRUNC_DIV_EXPR:
3173 case FLOOR_DIV_EXPR:
3174 case ROUND_DIV_EXPR:
3175 case EXACT_DIV_EXPR:
3176 if ((code0 == INTEGER_TYPE || code0 == REAL_TYPE
3177 || code0 == COMPLEX_TYPE || code0 == VECTOR_TYPE)
3178 && (code1 == INTEGER_TYPE || code1 == REAL_TYPE
3179 || code1 == COMPLEX_TYPE || code1 == VECTOR_TYPE))
3181 enum tree_code tcode0 = code0, tcode1 = code1;
3183 warn_for_div_by_zero (op1);
3185 if (tcode0 == COMPLEX_TYPE || tcode0 == VECTOR_TYPE)
3186 tcode0 = TREE_CODE (TREE_TYPE (TREE_TYPE (op0)));
3187 if (tcode1 == COMPLEX_TYPE || tcode1 == VECTOR_TYPE)
3188 tcode1 = TREE_CODE (TREE_TYPE (TREE_TYPE (op1)));
3190 if (!(tcode0 == INTEGER_TYPE && tcode1 == INTEGER_TYPE))
3191 resultcode = RDIV_EXPR;
3193 /* When dividing two signed integers, we have to promote to int.
3194 unless we divide by a constant != -1. Note that default
3195 conversion will have been performed on the operands at this
3196 point, so we have to dig out the original type to find out if
3198 shorten = ((TREE_CODE (op0) == NOP_EXPR
3199 && TYPE_UNSIGNED (TREE_TYPE (TREE_OPERAND (op0, 0))))
3200 || (TREE_CODE (op1) == INTEGER_CST
3201 && ! integer_all_onesp (op1)));
3210 if ((code0 == INTEGER_TYPE && code1 == INTEGER_TYPE)
3211 || (code0 == VECTOR_TYPE && code1 == VECTOR_TYPE))
3215 case TRUNC_MOD_EXPR:
3216 case FLOOR_MOD_EXPR:
3217 warn_for_div_by_zero (op1);
3219 if (code0 == INTEGER_TYPE && code1 == INTEGER_TYPE)
3221 /* Although it would be tempting to shorten always here, that loses
3222 on some targets, since the modulo instruction is undefined if the
3223 quotient can't be represented in the computation mode. We shorten
3224 only if unsigned or if dividing by something we know != -1. */
3225 shorten = ((TREE_CODE (op0) == NOP_EXPR
3226 && TYPE_UNSIGNED (TREE_TYPE (TREE_OPERAND (op0, 0))))
3227 || (TREE_CODE (op1) == INTEGER_CST
3228 && ! integer_all_onesp (op1)));
3233 case TRUTH_ANDIF_EXPR:
3234 case TRUTH_ORIF_EXPR:
3235 case TRUTH_AND_EXPR:
3237 result_type = boolean_type_node;
3240 /* Shift operations: result has same type as first operand;
3241 always convert second operand to int.
3242 Also set SHORT_SHIFT if shifting rightward. */
3245 if (code0 == INTEGER_TYPE && code1 == INTEGER_TYPE)
3247 result_type = type0;
3248 if (TREE_CODE (op1) == INTEGER_CST)
3250 if (tree_int_cst_lt (op1, integer_zero_node))
3251 warning (0, "right shift count is negative");
3254 if (! integer_zerop (op1))
3256 if (compare_tree_int (op1, TYPE_PRECISION (type0)) >= 0)
3257 warning (0, "right shift count >= width of type");
3260 /* Convert the shift-count to an integer, regardless of
3261 size of value being shifted. */
3262 if (TYPE_MAIN_VARIANT (TREE_TYPE (op1)) != integer_type_node)
3263 op1 = cp_convert (integer_type_node, op1);
3264 /* Avoid converting op1 to result_type later. */
3270 if (code0 == INTEGER_TYPE && code1 == INTEGER_TYPE)
3272 result_type = type0;
3273 if (TREE_CODE (op1) == INTEGER_CST)
3275 if (tree_int_cst_lt (op1, integer_zero_node))
3276 warning (0, "left shift count is negative");
3277 else if (compare_tree_int (op1, TYPE_PRECISION (type0)) >= 0)
3278 warning (0, "left shift count >= width of type");
3280 /* Convert the shift-count to an integer, regardless of
3281 size of value being shifted. */
3282 if (TYPE_MAIN_VARIANT (TREE_TYPE (op1)) != integer_type_node)
3283 op1 = cp_convert (integer_type_node, op1);
3284 /* Avoid converting op1 to result_type later. */
3291 if (code0 == INTEGER_TYPE && code1 == INTEGER_TYPE)
3293 result_type = type0;
3294 if (TREE_CODE (op1) == INTEGER_CST)
3296 if (tree_int_cst_lt (op1, integer_zero_node))
3297 warning (0, (code == LROTATE_EXPR)
3298 ? G_("left rotate count is negative")
3299 : G_("right rotate count is negative"));
3300 else if (compare_tree_int (op1, TYPE_PRECISION (type0)) >= 0)
3301 warning (0, (code == LROTATE_EXPR)
3302 ? G_("left rotate count >= width of type")
3303 : G_("right rotate count >= width of type"));
3305 /* Convert the shift-count to an integer, regardless of
3306 size of value being shifted. */
3307 if (TYPE_MAIN_VARIANT (TREE_TYPE (op1)) != integer_type_node)
3308 op1 = cp_convert (integer_type_node, op1);
3314 if (code0 == REAL_TYPE || code1 == REAL_TYPE)
3315 warning (OPT_Wfloat_equal,
3316 "comparing floating point with == or != is unsafe");
3317 if ((TREE_CODE (orig_op0) == STRING_CST && !integer_zerop (op1))
3318 || (TREE_CODE (orig_op1) == STRING_CST && !integer_zerop (op0)))
3319 warning (OPT_Waddress, "comparison with string literal results in unspecified behaviour");
3321 build_type = boolean_type_node;
3322 if ((code0 == INTEGER_TYPE || code0 == REAL_TYPE
3323 || code0 == COMPLEX_TYPE)
3324 && (code1 == INTEGER_TYPE || code1 == REAL_TYPE
3325 || code1 == COMPLEX_TYPE))
3327 else if ((code0 == POINTER_TYPE && code1 == POINTER_TYPE)
3328 || (TYPE_PTRMEM_P (type0) && TYPE_PTRMEM_P (type1)))
3329 result_type = composite_pointer_type (type0, type1, op0, op1,
3331 else if ((code0 == POINTER_TYPE || TYPE_PTRMEM_P (type0))
3332 && null_ptr_cst_p (op1))
3334 if (TREE_CODE (op0) == ADDR_EXPR
3335 && decl_with_nonnull_addr_p (TREE_OPERAND (op0, 0)))
3336 warning (OPT_Waddress, "the address of %qD will never be NULL",
3337 TREE_OPERAND (op0, 0));
3338 result_type = type0;
3340 else if ((code1 == POINTER_TYPE || TYPE_PTRMEM_P (type1))
3341 && null_ptr_cst_p (op0))
3343 if (TREE_CODE (op1) == ADDR_EXPR
3344 && decl_with_nonnull_addr_p (TREE_OPERAND (op1, 0)))
3345 warning (OPT_Waddress, "the address of %qD will never be NULL",
3346 TREE_OPERAND (op1, 0));
3347 result_type = type1;
3349 else if (code0 == POINTER_TYPE && code1 == INTEGER_TYPE)
3351 result_type = type0;
3352 error ("ISO C++ forbids comparison between pointer and integer");
3354 else if (code0 == INTEGER_TYPE && code1 == POINTER_TYPE)
3356 result_type = type1;
3357 error ("ISO C++ forbids comparison between pointer and integer");
3359 else if (TYPE_PTRMEMFUNC_P (type0) && null_ptr_cst_p (op1))
3361 if (TARGET_PTRMEMFUNC_VBIT_LOCATION
3362 == ptrmemfunc_vbit_in_delta)
3364 tree pfn0 = pfn_from_ptrmemfunc (op0);
3365 tree delta0 = build_ptrmemfunc_access_expr (op0,
3367 tree e1 = cp_build_binary_op (EQ_EXPR,
3369 fold_convert (TREE_TYPE (pfn0),
3370 integer_zero_node));
3371 tree e2 = cp_build_binary_op (BIT_AND_EXPR,
3374 e2 = cp_build_binary_op (EQ_EXPR, e2, integer_zero_node);
3375 op0 = cp_build_binary_op (TRUTH_ANDIF_EXPR, e1, e2);
3376 op1 = cp_convert (TREE_TYPE (op0), integer_one_node);
3380 op0 = build_ptrmemfunc_access_expr (op0, pfn_identifier);
3381 op1 = cp_convert (TREE_TYPE (op0), integer_zero_node);
3383 result_type = TREE_TYPE (op0);
3385 else if (TYPE_PTRMEMFUNC_P (type1) && null_ptr_cst_p (op0))
3386 return cp_build_binary_op (code, op1, op0);
3387 else if (TYPE_PTRMEMFUNC_P (type0) && TYPE_PTRMEMFUNC_P (type1)
3388 && same_type_p (type0, type1))
3390 /* E will be the final comparison. */
3392 /* E1 and E2 are for scratch. */
3400 if (TREE_SIDE_EFFECTS (op0))
3401 op0 = save_expr (op0);
3402 if (TREE_SIDE_EFFECTS (op1))
3403 op1 = save_expr (op1);
3405 pfn0 = pfn_from_ptrmemfunc (op0);
3406 pfn1 = pfn_from_ptrmemfunc (op1);
3407 delta0 = build_ptrmemfunc_access_expr (op0,
3409 delta1 = build_ptrmemfunc_access_expr (op1,
3411 if (TARGET_PTRMEMFUNC_VBIT_LOCATION
3412 == ptrmemfunc_vbit_in_delta)
3417 && ((op0.delta == op1.delta)
3418 || (!op0.pfn && op0.delta & 1 == 0
3419 && op1.delta & 1 == 0))
3421 The reason for the `!op0.pfn' bit is that a NULL
3422 pointer-to-member is any member with a zero PFN and
3423 LSB of the DELTA field is 0. */
3425 e1 = cp_build_binary_op (BIT_AND_EXPR,
3428 e1 = cp_build_binary_op (EQ_EXPR, e1, integer_zero_node);
3429 e2 = cp_build_binary_op (BIT_AND_EXPR,
3432 e2 = cp_build_binary_op (EQ_EXPR, e2, integer_zero_node);
3433 e1 = cp_build_binary_op (TRUTH_ANDIF_EXPR, e2, e1);
3434 e2 = cp_build_binary_op (EQ_EXPR,
3436 fold_convert (TREE_TYPE (pfn0),
3437 integer_zero_node));
3438 e2 = cp_build_binary_op (TRUTH_ANDIF_EXPR, e2, e1);
3439 e1 = cp_build_binary_op (EQ_EXPR, delta0, delta1);
3440 e1 = cp_build_binary_op (TRUTH_ORIF_EXPR, e1, e2);
3447 && (!op0.pfn || op0.delta == op1.delta))
3449 The reason for the `!op0.pfn' bit is that a NULL
3450 pointer-to-member is any member with a zero PFN; the
3451 DELTA field is unspecified. */
3453 e1 = cp_build_binary_op (EQ_EXPR, delta0, delta1);
3454 e2 = cp_build_binary_op (EQ_EXPR,
3456 fold_convert (TREE_TYPE (pfn0),
3457 integer_zero_node));
3458 e1 = cp_build_binary_op (TRUTH_ORIF_EXPR, e1, e2);
3460 e2 = build2 (EQ_EXPR, boolean_type_node, pfn0, pfn1);
3461 e = cp_build_binary_op (TRUTH_ANDIF_EXPR, e2, e1);
3462 if (code == EQ_EXPR)
3464 return cp_build_binary_op (EQ_EXPR, e, integer_zero_node);
3468 gcc_assert (!TYPE_PTRMEMFUNC_P (type0)
3469 || !same_type_p (TYPE_PTRMEMFUNC_FN_TYPE (type0),
3471 gcc_assert (!TYPE_PTRMEMFUNC_P (type1)
3472 || !same_type_p (TYPE_PTRMEMFUNC_FN_TYPE (type1),
3480 if ((code0 == INTEGER_TYPE || code0 == REAL_TYPE)
3481 && (code1 == INTEGER_TYPE || code1 == REAL_TYPE))
3483 else if (code0 == POINTER_TYPE && code1 == POINTER_TYPE)
3484 result_type = composite_pointer_type (type0, type1, op0, op1,
3492 if (TREE_CODE (orig_op0) == STRING_CST
3493 || TREE_CODE (orig_op1) == STRING_CST)
3494 warning (OPT_Waddress, "comparison with string literal results in unspecified behaviour");
3496 build_type = boolean_type_node;
3497 if ((code0 == INTEGER_TYPE || code0 == REAL_TYPE)
3498 && (code1 == INTEGER_TYPE || code1 == REAL_TYPE))
3500 else if (code0 == POINTER_TYPE && code1 == POINTER_TYPE)
3501 result_type = composite_pointer_type (type0, type1, op0, op1,
3503 else if (code0 == POINTER_TYPE && TREE_CODE (op1) == INTEGER_CST
3504 && integer_zerop (op1))
3505 result_type = type0;
3506 else if (code1 == POINTER_TYPE && TREE_CODE (op0) == INTEGER_CST
3507 && integer_zerop (op0))
3508 result_type = type1;
3509 else if (code0 == POINTER_TYPE && code1 == INTEGER_TYPE)
3511 result_type = type0;
3512 pedwarn ("ISO C++ forbids comparison between pointer and integer");
3514 else if (code0 == INTEGER_TYPE && code1 == POINTER_TYPE)
3516 result_type = type1;
3517 pedwarn ("ISO C++ forbids comparison between pointer and integer");
3521 case UNORDERED_EXPR:
3528 build_type = integer_type_node;
3529 if (code0 != REAL_TYPE || code1 != REAL_TYPE)
3531 error ("unordered comparison on non-floating point argument");
3532 return error_mark_node;
3541 if (((code0 == INTEGER_TYPE || code0 == REAL_TYPE || code0 == COMPLEX_TYPE)
3542 && (code1 == INTEGER_TYPE || code1 == REAL_TYPE
3543 || code1 == COMPLEX_TYPE)))
3544 arithmetic_types_p = 1;
3547 arithmetic_types_p = 0;
3548 /* Vector arithmetic is only allowed when both sides are vectors. */
3549 if (code0 == VECTOR_TYPE && code1 == VECTOR_TYPE)
3551 if (!tree_int_cst_equal (TYPE_SIZE (type0), TYPE_SIZE (type1))
3552 || !same_scalar_type_ignoring_signedness (TREE_TYPE (type0),
3555 binary_op_error (code);
3556 return error_mark_node;
3558 arithmetic_types_p = 1;
3561 /* Determine the RESULT_TYPE, if it is not already known. */
3563 && arithmetic_types_p
3564 && (shorten || common || short_compare))
3565 result_type = common_type (type0, type1);
3569 error ("invalid operands of types %qT and %qT to binary %qO",
3570 TREE_TYPE (orig_op0), TREE_TYPE (orig_op1), code);
3571 return error_mark_node;
3574 /* If we're in a template, the only thing we need to know is the
3576 if (processing_template_decl)
3577 return build2 (resultcode,
3578 build_type ? build_type : result_type,
3581 if (arithmetic_types_p)
3583 int none_complex = (code0 != COMPLEX_TYPE && code1 != COMPLEX_TYPE);
3585 /* For certain operations (which identify themselves by shorten != 0)
3586 if both args were extended from the same smaller type,
3587 do the arithmetic in that type and then extend.
3589 shorten !=0 and !=1 indicates a bitwise operation.
3590 For them, this optimization is safe only if
3591 both args are zero-extended or both are sign-extended.
3592 Otherwise, we might change the result.
3593 Eg, (short)-1 | (unsigned short)-1 is (int)-1
3594 but calculated in (unsigned short) it would be (unsigned short)-1. */
3596 if (shorten && none_complex)
3598 int unsigned0, unsigned1;
3599 tree arg0 = get_narrower (op0, &unsigned0);
3600 tree arg1 = get_narrower (op1, &unsigned1);
3601 /* UNS is 1 if the operation to be done is an unsigned one. */
3602 int uns = TYPE_UNSIGNED (result_type);
3605 final_type = result_type;
3607 /* Handle the case that OP0 does not *contain* a conversion
3608 but it *requires* conversion to FINAL_TYPE. */
3610 if (op0 == arg0 && TREE_TYPE (op0) != final_type)
3611 unsigned0 = TYPE_UNSIGNED (TREE_TYPE (op0));
3612 if (op1 == arg1 && TREE_TYPE (op1) != final_type)
3613 unsigned1 = TYPE_UNSIGNED (TREE_TYPE (op1));
3615 /* Now UNSIGNED0 is 1 if ARG0 zero-extends to FINAL_TYPE. */
3617 /* For bitwise operations, signedness of nominal type
3618 does not matter. Consider only how operands were extended. */
3622 /* Note that in all three cases below we refrain from optimizing
3623 an unsigned operation on sign-extended args.
3624 That would not be valid. */
3626 /* Both args variable: if both extended in same way
3627 from same width, do it in that width.
3628 Do it unsigned if args were zero-extended. */
3629 if ((TYPE_PRECISION (TREE_TYPE (arg0))
3630 < TYPE_PRECISION (result_type))
3631 && (TYPE_PRECISION (TREE_TYPE (arg1))
3632 == TYPE_PRECISION (TREE_TYPE (arg0)))
3633 && unsigned0 == unsigned1
3634 && (unsigned0 || !uns))
3635 result_type = c_common_signed_or_unsigned_type
3636 (unsigned0, common_type (TREE_TYPE (arg0), TREE_TYPE (arg1)));
3637 else if (TREE_CODE (arg0) == INTEGER_CST
3638 && (unsigned1 || !uns)
3639 && (TYPE_PRECISION (TREE_TYPE (arg1))
3640 < TYPE_PRECISION (result_type))
3641 && (type = c_common_signed_or_unsigned_type
3642 (unsigned1, TREE_TYPE (arg1)),
3643 int_fits_type_p (arg0, type)))
3645 else if (TREE_CODE (arg1) == INTEGER_CST
3646 && (unsigned0 || !uns)
3647 && (TYPE_PRECISION (TREE_TYPE (arg0))
3648 < TYPE_PRECISION (result_type))
3649 && (type = c_common_signed_or_unsigned_type
3650 (unsigned0, TREE_TYPE (arg0)),
3651 int_fits_type_p (arg1, type)))
3655 /* Shifts can be shortened if shifting right. */
3660 tree arg0 = get_narrower (op0, &unsigned_arg);
3662 final_type = result_type;
3664 if (arg0 == op0 && final_type == TREE_TYPE (op0))
3665 unsigned_arg = TYPE_UNSIGNED (TREE_TYPE (op0));
3667 if (TYPE_PRECISION (TREE_TYPE (arg0)) < TYPE_PRECISION (result_type)
3668 /* We can shorten only if the shift count is less than the
3669 number of bits in the smaller type size. */
3670 && compare_tree_int (op1, TYPE_PRECISION (TREE_TYPE (arg0))) < 0
3671 /* If arg is sign-extended and then unsigned-shifted,
3672 we can simulate this with a signed shift in arg's type
3673 only if the extended result is at least twice as wide
3674 as the arg. Otherwise, the shift could use up all the
3675 ones made by sign-extension and bring in zeros.
3676 We can't optimize that case at all, but in most machines
3677 it never happens because available widths are 2**N. */
3678 && (!TYPE_UNSIGNED (final_type)
3680 || (((unsigned) 2 * TYPE_PRECISION (TREE_TYPE (arg0)))
3681 <= TYPE_PRECISION (result_type))))
3683 /* Do an unsigned shift if the operand was zero-extended. */
3685 = c_common_signed_or_unsigned_type (unsigned_arg,
3687 /* Convert value-to-be-shifted to that type. */
3688 if (TREE_TYPE (op0) != result_type)
3689 op0 = cp_convert (result_type, op0);
3694 /* Comparison operations are shortened too but differently.
3695 They identify themselves by setting short_compare = 1. */
3699 /* Don't write &op0, etc., because that would prevent op0
3700 from being kept in a register.
3701 Instead, make copies of the our local variables and
3702 pass the copies by reference, then copy them back afterward. */
3703 tree xop0 = op0, xop1 = op1, xresult_type = result_type;
3704 enum tree_code xresultcode = resultcode;
3706 = shorten_compare (&xop0, &xop1, &xresult_type, &xresultcode);
3708 return cp_convert (boolean_type_node, val);
3709 op0 = xop0, op1 = xop1;
3711 resultcode = xresultcode;
3714 if ((short_compare || code == MIN_EXPR || code == MAX_EXPR)
3715 && warn_sign_compare
3716 /* Do not warn until the template is instantiated; we cannot
3717 bound the ranges of the arguments until that point. */
3718 && !processing_template_decl)
3720 int op0_signed = !TYPE_UNSIGNED (TREE_TYPE (orig_op0));
3721 int op1_signed = !TYPE_UNSIGNED (TREE_TYPE (orig_op1));
3723 int unsignedp0, unsignedp1;
3724 tree primop0 = get_narrower (op0, &unsignedp0);
3725 tree primop1 = get_narrower (op1, &unsignedp1);
3727 /* Check for comparison of different enum types. */
3728 if (TREE_CODE (TREE_TYPE (orig_op0)) == ENUMERAL_TYPE
3729 && TREE_CODE (TREE_TYPE (orig_op1)) == ENUMERAL_TYPE
3730 && TYPE_MAIN_VARIANT (TREE_TYPE (orig_op0))
3731 != TYPE_MAIN_VARIANT (TREE_TYPE (orig_op1)))
3733 warning (0, "comparison between types %q#T and %q#T",
3734 TREE_TYPE (orig_op0), TREE_TYPE (orig_op1));
3737 /* Give warnings for comparisons between signed and unsigned
3738 quantities that may fail. */
3739 /* Do the checking based on the original operand trees, so that
3740 casts will be considered, but default promotions won't be. */
3742 /* Do not warn if the comparison is being done in a signed type,
3743 since the signed type will only be chosen if it can represent
3744 all the values of the unsigned type. */
3745 if (!TYPE_UNSIGNED (result_type))
3747 /* Do not warn if both operands are unsigned. */
3748 else if (op0_signed == op1_signed)
3750 /* Do not warn if the signed quantity is an unsuffixed
3751 integer literal (or some static constant expression
3752 involving such literals or a conditional expression
3753 involving such literals) and it is non-negative. */
3754 else if ((op0_signed && tree_expr_nonnegative_p (orig_op0))
3755 || (op1_signed && tree_expr_nonnegative_p (orig_op1)))
3757 /* Do not warn if the comparison is an equality operation,
3758 the unsigned quantity is an integral constant and it does
3759 not use the most significant bit of result_type. */
3760 else if ((resultcode == EQ_EXPR || resultcode == NE_EXPR)
3761 && ((op0_signed && TREE_CODE (orig_op1) == INTEGER_CST
3762 && int_fits_type_p (orig_op1, c_common_signed_type
3764 || (op1_signed && TREE_CODE (orig_op0) == INTEGER_CST
3765 && int_fits_type_p (orig_op0, c_common_signed_type
3769 warning (0, "comparison between signed and unsigned integer expressions");
3771 /* Warn if two unsigned values are being compared in a size
3772 larger than their original size, and one (and only one) is the
3773 result of a `~' operator. This comparison will always fail.
3775 Also warn if one operand is a constant, and the constant does not
3776 have all bits set that are set in the ~ operand when it is
3779 if ((TREE_CODE (primop0) == BIT_NOT_EXPR)
3780 ^ (TREE_CODE (primop1) == BIT_NOT_EXPR))
3782 if (TREE_CODE (primop0) == BIT_NOT_EXPR)
3783 primop0 = get_narrower (TREE_OPERAND (op0, 0), &unsignedp0);
3784 if (TREE_CODE (primop1) == BIT_NOT_EXPR)
3785 primop1 = get_narrower (TREE_OPERAND (op1, 0), &unsignedp1);
3787 if (host_integerp (primop0, 0) || host_integerp (primop1, 0))
3790 HOST_WIDE_INT constant, mask;
3794 if (host_integerp (primop0, 0))
3797 unsignedp = unsignedp1;
3798 constant = tree_low_cst (primop0, 0);
3803 unsignedp = unsignedp0;
3804 constant = tree_low_cst (primop1, 0);
3807 bits = TYPE_PRECISION (TREE_TYPE (primop));
3808 if (bits < TYPE_PRECISION (result_type)
3809 && bits < HOST_BITS_PER_LONG && unsignedp)
3811 mask = (~ (HOST_WIDE_INT) 0) << bits;
3812 if ((mask & constant) != mask)
3813 warning (0, "comparison of promoted ~unsigned with constant");
3816 else if (unsignedp0 && unsignedp1
3817 && (TYPE_PRECISION (TREE_TYPE (primop0))
3818 < TYPE_PRECISION (result_type))
3819 && (TYPE_PRECISION (TREE_TYPE (primop1))
3820 < TYPE_PRECISION (result_type)))
3821 warning (0, "comparison of promoted ~unsigned with unsigned");
3826 /* Issue warnings about peculiar, but valid, uses of NULL. */
3827 if ((orig_op0 == null_node || orig_op1 == null_node)
3828 /* It's reasonable to use pointer values as operands of &&
3829 and ||, so NULL is no exception. */
3830 && code != TRUTH_ANDIF_EXPR && code != TRUTH_ORIF_EXPR
3831 && ( /* Both are NULL (or 0) and the operation was not a comparison. */
3832 (null_ptr_cst_p (orig_op0) && null_ptr_cst_p (orig_op1)
3833 && code != EQ_EXPR && code != NE_EXPR)
3834 /* Or if one of OP0 or OP1 is neither a pointer nor NULL. */
3835 || (!null_ptr_cst_p (orig_op0) && TREE_CODE (TREE_TYPE (op0)) != POINTER_TYPE)
3836 || (!null_ptr_cst_p (orig_op1) && TREE_CODE (TREE_TYPE (op1)) != POINTER_TYPE)))
3837 /* Some sort of arithmetic operation involving NULL was
3838 performed. Note that pointer-difference and pointer-addition
3839 have already been handled above, and so we don't end up here in
3841 warning (OPT_Wpointer_arith, "NULL used in arithmetic");
3844 /* If CONVERTED is zero, both args will be converted to type RESULT_TYPE.
3845 Then the expression will be built.
3846 It will be given type FINAL_TYPE if that is nonzero;
3847 otherwise, it will be given type RESULT_TYPE. */
3850 if (TREE_TYPE (op0) != result_type)
3851 op0 = cp_convert_and_check (result_type, op0);
3852 if (TREE_TYPE (op1) != result_type)
3853 op1 = cp_convert_and_check (result_type, op1);
3855 if (op0 == error_mark_node || op1 == error_mark_node)
3856 return error_mark_node;
3859 if (build_type == NULL_TREE)
3860 build_type = result_type;
3862 result = build2 (resultcode, build_type, op0, op1);
3863 result = fold_if_not_in_template (result);
3864 if (final_type != 0)
3865 result = cp_convert (final_type, result);
3867 if (TREE_OVERFLOW_P (result)
3868 && !TREE_OVERFLOW_P (op0)
3869 && !TREE_OVERFLOW_P (op1))
3870 overflow_warning (result);
3875 /* Return a tree for the sum or difference (RESULTCODE says which)
3876 of pointer PTROP and integer INTOP. */
3879 cp_pointer_int_sum (enum tree_code resultcode, tree ptrop, tree intop)
3881 tree res_type = TREE_TYPE (ptrop);
3883 /* pointer_int_sum() uses size_in_bytes() on the TREE_TYPE(res_type)
3884 in certain circumstance (when it's valid to do so). So we need
3885 to make sure it's complete. We don't need to check here, if we
3886 can actually complete it at all, as those checks will be done in
3887 pointer_int_sum() anyway. */
3888 complete_type (TREE_TYPE (res_type));
3890 return pointer_int_sum (resultcode, ptrop,
3891 fold_if_not_in_template (intop));
3894 /* Return a tree for the difference of pointers OP0 and OP1.
3895 The resulting tree has type int. */
3898 pointer_diff (tree op0, tree op1, tree ptrtype)
3901 tree restype = ptrdiff_type_node;
3902 tree target_type = TREE_TYPE (ptrtype);
3904 if (!complete_type_or_else (target_type, NULL_TREE))
3905 return error_mark_node;
3907 if (pedantic || warn_pointer_arith)
3909 if (TREE_CODE (target_type) == VOID_TYPE)
3910 pedwarn ("ISO C++ forbids using pointer of type %<void *%> in subtraction");
3911 if (TREE_CODE (target_type) == FUNCTION_TYPE)
3912 pedwarn ("ISO C++ forbids using pointer to a function in subtraction");
3913 if (TREE_CODE (target_type) == METHOD_TYPE)
3914 pedwarn ("ISO C++ forbids using pointer to a method in subtraction");
3917 /* First do the subtraction as integers;
3918 then drop through to build the divide operator. */
3920 op0 = cp_build_binary_op (MINUS_EXPR,
3921 cp_convert (restype, op0),
3922 cp_convert (restype, op1));
3924 /* This generates an error if op1 is a pointer to an incomplete type. */
3925 if (!COMPLETE_TYPE_P (TREE_TYPE (TREE_TYPE (op1))))
3926 error ("invalid use of a pointer to an incomplete type in pointer arithmetic");
3928 op1 = (TYPE_PTROB_P (ptrtype)
3929 ? size_in_bytes (target_type)
3930 : integer_one_node);
3932 /* Do the division. */
3934 result = build2 (EXACT_DIV_EXPR, restype, op0, cp_convert (restype, op1));
3935 return fold_if_not_in_template (result);
3938 /* Construct and perhaps optimize a tree representation
3939 for a unary operation. CODE, a tree_code, specifies the operation
3940 and XARG is the operand. */
3943 build_x_unary_op (enum tree_code code, tree xarg)
3945 tree orig_expr = xarg;
3949 if (processing_template_decl)
3951 if (type_dependent_expression_p (xarg))
3952 return build_min_nt (code, xarg, NULL_TREE);
3954 xarg = build_non_dependent_expr (xarg);
3959 /* [expr.unary.op] says:
3961 The address of an object of incomplete type can be taken.
3963 (And is just the ordinary address operator, not an overloaded
3964 "operator &".) However, if the type is a template
3965 specialization, we must complete the type at this point so that
3966 an overloaded "operator &" will be available if required. */
3967 if (code == ADDR_EXPR
3968 && TREE_CODE (xarg) != TEMPLATE_ID_EXPR
3969 && ((CLASS_TYPE_P (TREE_TYPE (xarg))
3970 && !COMPLETE_TYPE_P (complete_type (TREE_TYPE (xarg))))
3971 || (TREE_CODE (xarg) == OFFSET_REF)))
3972 /* Don't look for a function. */;
3974 exp = build_new_op (code, LOOKUP_NORMAL, xarg, NULL_TREE, NULL_TREE,
3975 /*overloaded_p=*/NULL);
3976 if (!exp && code == ADDR_EXPR)
3978 /* A pointer to member-function can be formed only by saying
3980 if (!flag_ms_extensions && TREE_CODE (TREE_TYPE (xarg)) == METHOD_TYPE
3981 && (TREE_CODE (xarg) != OFFSET_REF || !PTRMEM_OK_P (xarg)))
3983 if (TREE_CODE (xarg) != OFFSET_REF
3984 || !TYPE_P (TREE_OPERAND (xarg, 0)))
3986 error ("invalid use of %qE to form a pointer-to-member-function",
3988 if (TREE_CODE (xarg) != OFFSET_REF)
3989 inform (" a qualified-id is required");
3990 return error_mark_node;
3994 error ("parentheses around %qE cannot be used to form a"
3995 " pointer-to-member-function",
3997 PTRMEM_OK_P (xarg) = 1;
4001 if (TREE_CODE (xarg) == OFFSET_REF)
4003 ptrmem = PTRMEM_OK_P (xarg);
4005 if (!ptrmem && !flag_ms_extensions
4006 && TREE_CODE (TREE_TYPE (TREE_OPERAND (xarg, 1))) == METHOD_TYPE)
4008 /* A single non-static member, make sure we don't allow a
4009 pointer-to-member. */
4010 xarg = build2 (OFFSET_REF, TREE_TYPE (xarg),
4011 TREE_OPERAND (xarg, 0),
4012 ovl_cons (TREE_OPERAND (xarg, 1), NULL_TREE));
4013 PTRMEM_OK_P (xarg) = ptrmem;
4016 else if (TREE_CODE (xarg) == TARGET_EXPR)
4017 warning (0, "taking address of temporary");
4018 exp = build_unary_op (ADDR_EXPR, xarg, 0);
4021 if (processing_template_decl && exp != error_mark_node)
4022 exp = build_min_non_dep (code, exp, orig_expr,
4023 /*For {PRE,POST}{INC,DEC}REMENT_EXPR*/NULL_TREE);
4024 if (TREE_CODE (exp) == ADDR_EXPR)
4025 PTRMEM_OK_P (exp) = ptrmem;
4029 /* Like c_common_truthvalue_conversion, but handle pointer-to-member
4030 constants, where a null value is represented by an INTEGER_CST of
4034 cp_truthvalue_conversion (tree expr)
4036 tree type = TREE_TYPE (expr);
4037 if (TYPE_PTRMEM_P (type))
4038 return build_binary_op (NE_EXPR, expr, integer_zero_node, 1);
4040 return c_common_truthvalue_conversion (expr);
4043 /* Just like cp_truthvalue_conversion, but we want a CLEANUP_POINT_EXPR. */
4046 condition_conversion (tree expr)
4049 if (processing_template_decl)
4051 t = perform_implicit_conversion (boolean_type_node, expr);
4052 t = fold_build_cleanup_point_expr (boolean_type_node, t);
4056 /* Return an ADDR_EXPR giving the address of T. This function
4057 attempts no optimizations or simplifications; it is a low-level
4061 build_address (tree t)
4065 if (error_operand_p (t) || !cxx_mark_addressable (t))
4066 return error_mark_node;
4068 addr = build1 (ADDR_EXPR, build_pointer_type (TREE_TYPE (t)), t);
4073 /* Return a NOP_EXPR converting EXPR to TYPE. */
4076 build_nop (tree type, tree expr)
4078 if (type == error_mark_node || error_operand_p (expr))
4080 return build1 (NOP_EXPR, type, expr);
4083 /* C++: Must handle pointers to members.
4085 Perhaps type instantiation should be extended to handle conversion
4086 from aggregates to types we don't yet know we want? (Or are those
4087 cases typically errors which should be reported?)
4089 NOCONVERT nonzero suppresses the default promotions
4090 (such as from short to int). */
4093 build_unary_op (enum tree_code code, tree xarg, int noconvert)
4095 /* No default_conversion here. It causes trouble for ADDR_EXPR. */
4098 const char *errstring = NULL;
4100 const char *invalid_op_diag;
4102 if (arg == error_mark_node)
4103 return error_mark_node;
4105 if ((invalid_op_diag
4106 = targetm.invalid_unary_op ((code == UNARY_PLUS_EXPR
4111 error (invalid_op_diag);
4112 return error_mark_node;
4117 case UNARY_PLUS_EXPR:
4120 int flags = WANT_ARITH | WANT_ENUM;
4121 /* Unary plus (but not unary minus) is allowed on pointers. */
4122 if (code == UNARY_PLUS_EXPR)
4123 flags |= WANT_POINTER;
4124 arg = build_expr_type_conversion (flags, arg, true);
4126 errstring = (code == NEGATE_EXPR
4127 ? "wrong type argument to unary minus"
4128 : "wrong type argument to unary plus");
4131 if (!noconvert && CP_INTEGRAL_TYPE_P (TREE_TYPE (arg)))
4132 arg = perform_integral_promotions (arg);
4134 /* Make sure the result is not an lvalue: a unary plus or minus
4135 expression is always a rvalue. */
4142 if (TREE_CODE (TREE_TYPE (arg)) == COMPLEX_TYPE)
4146 arg = default_conversion (arg);
4148 else if (!(arg = build_expr_type_conversion (WANT_INT | WANT_ENUM
4151 errstring = "wrong type argument to bit-complement";
4152 else if (!noconvert && CP_INTEGRAL_TYPE_P (TREE_TYPE (arg)))
4153 arg = perform_integral_promotions (arg);
4157 if (!(arg = build_expr_type_conversion (WANT_ARITH | WANT_ENUM, arg, true)))
4158 errstring = "wrong type argument to abs";
4159 else if (!noconvert)
4160 arg = default_conversion (arg);
4164 /* Conjugating a real value is a no-op, but allow it anyway. */
4165 if (!(arg = build_expr_type_conversion (WANT_ARITH | WANT_ENUM, arg, true)))
4166 errstring = "wrong type argument to conjugation";
4167 else if (!noconvert)
4168 arg = default_conversion (arg);
4171 case TRUTH_NOT_EXPR:
4172 arg = perform_implicit_conversion (boolean_type_node, arg);
4173 val = invert_truthvalue (arg);
4174 if (arg != error_mark_node)
4176 errstring = "in argument to unary !";
4183 if (TREE_CODE (arg) == COMPLEX_CST)
4184 return TREE_REALPART (arg);
4185 else if (TREE_CODE (TREE_TYPE (arg)) == COMPLEX_TYPE)
4187 arg = build1 (REALPART_EXPR, TREE_TYPE (TREE_TYPE (arg)), arg);
4188 return fold_if_not_in_template (arg);
4194 if (TREE_CODE (arg) == COMPLEX_CST)
4195 return TREE_IMAGPART (arg);
4196 else if (TREE_CODE (TREE_TYPE (arg)) == COMPLEX_TYPE)
4198 arg = build1 (IMAGPART_EXPR, TREE_TYPE (TREE_TYPE (arg)), arg);
4199 return fold_if_not_in_template (arg);
4202 return cp_convert (TREE_TYPE (arg), integer_zero_node);
4204 case PREINCREMENT_EXPR:
4205 case POSTINCREMENT_EXPR:
4206 case PREDECREMENT_EXPR:
4207 case POSTDECREMENT_EXPR:
4208 /* Handle complex lvalues (when permitted)
4209 by reduction to simpler cases. */
4211 val = unary_complex_lvalue (code, arg);
4215 /* Increment or decrement the real part of the value,
4216 and don't change the imaginary part. */
4217 if (TREE_CODE (TREE_TYPE (arg)) == COMPLEX_TYPE)
4221 arg = stabilize_reference (arg);
4222 real = build_unary_op (REALPART_EXPR, arg, 1);
4223 imag = build_unary_op (IMAGPART_EXPR, arg, 1);
4224 return build2 (COMPLEX_EXPR, TREE_TYPE (arg),
4225 build_unary_op (code, real, 1), imag);
4228 /* Report invalid types. */
4230 if (!(arg = build_expr_type_conversion (WANT_ARITH | WANT_POINTER,
4233 if (code == PREINCREMENT_EXPR)
4234 errstring ="no pre-increment operator for type";
4235 else if (code == POSTINCREMENT_EXPR)
4236 errstring ="no post-increment operator for type";
4237 else if (code == PREDECREMENT_EXPR)
4238 errstring ="no pre-decrement operator for type";
4240 errstring ="no post-decrement operator for type";
4244 /* Report something read-only. */
4246 if (CP_TYPE_CONST_P (TREE_TYPE (arg))
4247 || TREE_READONLY (arg))
4248 readonly_error (arg, ((code == PREINCREMENT_EXPR
4249 || code == POSTINCREMENT_EXPR)
4250 ? "increment" : "decrement"));
4255 tree result_type = TREE_TYPE (arg);
4257 declared_type = unlowered_expr_type (arg);
4259 arg = get_unwidened (arg, 0);
4260 argtype = TREE_TYPE (arg);
4262 /* ARM $5.2.5 last annotation says this should be forbidden. */
4263 if (TREE_CODE (argtype) == ENUMERAL_TYPE)
4264 pedwarn ((code == PREINCREMENT_EXPR || code == POSTINCREMENT_EXPR)
4265 ? G_("ISO C++ forbids incrementing an enum")
4266 : G_("ISO C++ forbids decrementing an enum"));
4268 /* Compute the increment. */
4270 if (TREE_CODE (argtype) == POINTER_TYPE)
4272 tree type = complete_type (TREE_TYPE (argtype));
4274 if (!COMPLETE_OR_VOID_TYPE_P (type))
4275 error (((code == PREINCREMENT_EXPR
4276 || code == POSTINCREMENT_EXPR))
4277 ? G_("cannot increment a pointer to incomplete type %qT")
4278 : G_("cannot decrement a pointer to incomplete type %qT"),
4279 TREE_TYPE (argtype));
4280 else if ((pedantic || warn_pointer_arith)
4281 && !TYPE_PTROB_P (argtype))
4282 pedwarn ((code == PREINCREMENT_EXPR
4283 || code == POSTINCREMENT_EXPR)
4284 ? G_("ISO C++ forbids incrementing a pointer of type %qT")
4285 : G_("ISO C++ forbids decrementing a pointer of type %qT"),
4287 inc = cxx_sizeof_nowarn (TREE_TYPE (argtype));
4290 inc = integer_one_node;
4292 inc = cp_convert (argtype, inc);
4294 /* Complain about anything else that is not a true lvalue. */
4295 if (!lvalue_or_else (arg, ((code == PREINCREMENT_EXPR
4296 || code == POSTINCREMENT_EXPR)
4297 ? lv_increment : lv_decrement)))
4298 return error_mark_node;
4300 /* Forbid using -- on `bool'. */
4301 if (same_type_p (declared_type, boolean_type_node))
4303 if (code == POSTDECREMENT_EXPR || code == PREDECREMENT_EXPR)
4305 error ("invalid use of %<--%> on bool variable %qD", arg);
4306 return error_mark_node;
4308 val = boolean_increment (code, arg);
4311 val = build2 (code, TREE_TYPE (arg), arg, inc);
4313 TREE_SIDE_EFFECTS (val) = 1;
4314 return cp_convert (result_type, val);
4318 /* Note that this operation never does default_conversion
4319 regardless of NOCONVERT. */
4321 argtype = lvalue_type (arg);
4323 if (TREE_CODE (arg) == OFFSET_REF)
4326 if (TREE_CODE (argtype) == REFERENCE_TYPE)
4328 tree type = build_pointer_type (TREE_TYPE (argtype));
4329 arg = build1 (CONVERT_EXPR, type, arg);
4332 else if (pedantic && DECL_MAIN_P (arg))
4334 pedwarn ("ISO C++ forbids taking address of function %<::main%>");
4336 /* Let &* cancel out to simplify resulting code. */
4337 if (TREE_CODE (arg) == INDIRECT_REF)
4339 /* We don't need to have `current_class_ptr' wrapped in a
4340 NON_LVALUE_EXPR node. */
4341 if (arg == current_class_ref)
4342 return current_class_ptr;
4344 arg = TREE_OPERAND (arg, 0);
4345 if (TREE_CODE (TREE_TYPE (arg)) == REFERENCE_TYPE)
4347 tree type = build_pointer_type (TREE_TYPE (TREE_TYPE (arg)));
4348 arg = build1 (CONVERT_EXPR, type, arg);
4351 /* Don't let this be an lvalue. */
4356 /* Uninstantiated types are all functions. Taking the
4357 address of a function is a no-op, so just return the
4360 gcc_assert (TREE_CODE (arg) != IDENTIFIER_NODE
4361 || !IDENTIFIER_OPNAME_P (arg));
4363 if (TREE_CODE (arg) == COMPONENT_REF && type_unknown_p (arg)
4364 && !really_overloaded_fn (TREE_OPERAND (arg, 1)))
4366 /* They're trying to take the address of a unique non-static
4367 member function. This is ill-formed (except in MS-land),
4368 but let's try to DTRT.
4369 Note: We only handle unique functions here because we don't
4370 want to complain if there's a static overload; non-unique
4371 cases will be handled by instantiate_type. But we need to
4372 handle this case here to allow casts on the resulting PMF.
4373 We could defer this in non-MS mode, but it's easier to give
4374 a useful error here. */
4376 /* Inside constant member functions, the `this' pointer
4377 contains an extra const qualifier. TYPE_MAIN_VARIANT
4378 is used here to remove this const from the diagnostics
4379 and the created OFFSET_REF. */
4380 tree base = TYPE_MAIN_VARIANT (TREE_TYPE (TREE_OPERAND (arg, 0)));
4381 tree fn = get_first_fn (TREE_OPERAND (arg, 1));
4384 if (! flag_ms_extensions)
4386 tree name = DECL_NAME (fn);
4387 if (current_class_type
4388 && TREE_OPERAND (arg, 0) == current_class_ref)
4389 /* An expression like &memfn. */
4390 pedwarn ("ISO C++ forbids taking the address of an unqualified"
4391 " or parenthesized non-static member function to form"
4392 " a pointer to member function. Say %<&%T::%D%>",
4395 pedwarn ("ISO C++ forbids taking the address of a bound member"
4396 " function to form a pointer to member function."
4400 arg = build_offset_ref (base, fn, /*address_p=*/true);
4404 if (type_unknown_p (arg))
4405 return build1 (ADDR_EXPR, unknown_type_node, arg);
4407 /* Handle complex lvalues (when permitted)
4408 by reduction to simpler cases. */
4409 val = unary_complex_lvalue (code, arg);
4413 switch (TREE_CODE (arg))
4418 case FIX_TRUNC_EXPR:
4419 if (! lvalue_p (arg) && pedantic)
4420 pedwarn ("ISO C++ forbids taking the address of a cast to a non-lvalue expression");
4424 arg = BASELINK_FUNCTIONS (arg);
4428 arg = OVL_CURRENT (arg);
4432 /* Turn a reference to a non-static data member into a
4433 pointer-to-member. */
4438 if (!PTRMEM_OK_P (arg))
4439 return build_unary_op (code, arg, 0);
4441 t = TREE_OPERAND (arg, 1);
4442 if (TREE_CODE (TREE_TYPE (t)) == REFERENCE_TYPE)
4444 error ("cannot create pointer to reference member %qD", t);
4445 return error_mark_node;
4448 type = build_ptrmem_type (context_for_name_lookup (t),
4450 t = make_ptrmem_cst (type, TREE_OPERAND (arg, 1));
4458 /* Anything not already handled and not a true memory reference
4460 if (TREE_CODE (argtype) != FUNCTION_TYPE
4461 && TREE_CODE (argtype) != METHOD_TYPE
4462 && TREE_CODE (arg) != OFFSET_REF
4463 && !lvalue_or_else (arg, lv_addressof))
4464 return error_mark_node;
4466 if (argtype != error_mark_node)
4467 argtype = build_pointer_type (argtype);
4469 /* In a template, we are processing a non-dependent expression
4470 so we can just form an ADDR_EXPR with the correct type. */
4471 if (processing_template_decl)
4473 val = build_address (arg);
4474 if (TREE_CODE (arg) == OFFSET_REF)
4475 PTRMEM_OK_P (val) = PTRMEM_OK_P (arg);
4479 if (TREE_CODE (arg) != COMPONENT_REF)
4481 val = build_address (arg);
4482 if (TREE_CODE (arg) == OFFSET_REF)
4483 PTRMEM_OK_P (val) = PTRMEM_OK_P (arg);
4485 else if (TREE_CODE (TREE_OPERAND (arg, 1)) == BASELINK)
4487 tree fn = BASELINK_FUNCTIONS (TREE_OPERAND (arg, 1));
4489 /* We can only get here with a single static member
4491 gcc_assert (TREE_CODE (fn) == FUNCTION_DECL
4492 && DECL_STATIC_FUNCTION_P (fn));
4494 val = build_address (fn);
4495 if (TREE_SIDE_EFFECTS (TREE_OPERAND (arg, 0)))
4496 /* Do not lose object's side effects. */
4497 val = build2 (COMPOUND_EXPR, TREE_TYPE (val),
4498 TREE_OPERAND (arg, 0), val);
4500 else if (DECL_C_BIT_FIELD (TREE_OPERAND (arg, 1)))
4502 error ("attempt to take address of bit-field structure member %qD",
4503 TREE_OPERAND (arg, 1));
4504 return error_mark_node;
4508 tree object = TREE_OPERAND (arg, 0);
4509 tree field = TREE_OPERAND (arg, 1);
4510 gcc_assert (same_type_ignoring_top_level_qualifiers_p
4511 (TREE_TYPE (object), decl_type_context (field)));
4512 val = build_address (arg);
4515 if (TREE_CODE (argtype) == POINTER_TYPE
4516 && TREE_CODE (TREE_TYPE (argtype)) == METHOD_TYPE)
4518 build_ptrmemfunc_type (argtype);
4519 val = build_ptrmemfunc (argtype, val, 0,
4520 /*c_cast_p=*/false);
4532 argtype = TREE_TYPE (arg);
4533 return fold_if_not_in_template (build1 (code, argtype, arg));
4536 error ("%s", errstring);
4537 return error_mark_node;
4540 /* Apply unary lvalue-demanding operator CODE to the expression ARG
4541 for certain kinds of expressions which are not really lvalues
4542 but which we can accept as lvalues.
4544 If ARG is not a kind of expression we can handle, return
4548 unary_complex_lvalue (enum tree_code code, tree arg)
4550 /* Inside a template, making these kinds of adjustments is
4551 pointless; we are only concerned with the type of the
4553 if (processing_template_decl)
4556 /* Handle (a, b) used as an "lvalue". */
4557 if (TREE_CODE (arg) == COMPOUND_EXPR)
4559 tree real_result = build_unary_op (code, TREE_OPERAND (arg, 1), 0);
4560 return build2 (COMPOUND_EXPR, TREE_TYPE (real_result),
4561 TREE_OPERAND (arg, 0), real_result);
4564 /* Handle (a ? b : c) used as an "lvalue". */
4565 if (TREE_CODE (arg) == COND_EXPR
4566 || TREE_CODE (arg) == MIN_EXPR || TREE_CODE (arg) == MAX_EXPR)
4567 return rationalize_conditional_expr (code, arg);
4569 /* Handle (a = b), (++a), and (--a) used as an "lvalue". */
4570 if (TREE_CODE (arg) == MODIFY_EXPR
4571 || TREE_CODE (arg) == PREINCREMENT_EXPR
4572 || TREE_CODE (arg) == PREDECREMENT_EXPR)
4574 tree lvalue = TREE_OPERAND (arg, 0);
4575 if (TREE_SIDE_EFFECTS (lvalue))
4577 lvalue = stabilize_reference (lvalue);
4578 arg = build2 (TREE_CODE (arg), TREE_TYPE (arg),
4579 lvalue, TREE_OPERAND (arg, 1));
4581 return unary_complex_lvalue
4582 (code, build2 (COMPOUND_EXPR, TREE_TYPE (lvalue), arg, lvalue));
4585 if (code != ADDR_EXPR)
4588 /* Handle (a = b) used as an "lvalue" for `&'. */
4589 if (TREE_CODE (arg) == MODIFY_EXPR
4590 || TREE_CODE (arg) == INIT_EXPR)
4592 tree real_result = build_unary_op (code, TREE_OPERAND (arg, 0), 0);
4593 arg = build2 (COMPOUND_EXPR, TREE_TYPE (real_result),
4595 TREE_NO_WARNING (arg) = 1;
4599 if (TREE_CODE (TREE_TYPE (arg)) == FUNCTION_TYPE
4600 || TREE_CODE (TREE_TYPE (arg)) == METHOD_TYPE
4601 || TREE_CODE (arg) == OFFSET_REF)
4604 /* We permit compiler to make function calls returning
4605 objects of aggregate type look like lvalues. */
4609 if (TREE_CODE (targ) == SAVE_EXPR)
4610 targ = TREE_OPERAND (targ, 0);
4612 if (TREE_CODE (targ) == CALL_EXPR && IS_AGGR_TYPE (TREE_TYPE (targ)))
4614 if (TREE_CODE (arg) == SAVE_EXPR)
4617 targ = build_cplus_new (TREE_TYPE (arg), arg);
4618 return build1 (ADDR_EXPR, build_pointer_type (TREE_TYPE (arg)), targ);
4621 if (TREE_CODE (arg) == SAVE_EXPR && TREE_CODE (targ) == INDIRECT_REF)
4622 return build3 (SAVE_EXPR, build_pointer_type (TREE_TYPE (arg)),
4623 TREE_OPERAND (targ, 0), current_function_decl, NULL);
4626 /* Don't let anything else be handled specially. */
4630 /* Mark EXP saying that we need to be able to take the
4631 address of it; it should not be allocated in a register.
4632 Value is true if successful.
4634 C++: we do not allow `current_class_ptr' to be addressable. */
4637 cxx_mark_addressable (tree exp)
4642 switch (TREE_CODE (x))
4649 x = TREE_OPERAND (x, 0);
4653 if (x == current_class_ptr)
4655 error ("cannot take the address of %<this%>, which is an rvalue expression");
4656 TREE_ADDRESSABLE (x) = 1; /* so compiler doesn't die later. */
4662 /* Caller should not be trying to mark initialized
4663 constant fields addressable. */
4664 gcc_assert (DECL_LANG_SPECIFIC (x) == 0
4665 || DECL_IN_AGGR_P (x) == 0
4667 || DECL_EXTERNAL (x));
4672 if (DECL_REGISTER (x) && !TREE_ADDRESSABLE (x)
4673 && !DECL_ARTIFICIAL (x))
4675 if (TREE_CODE (x) == VAR_DECL && DECL_HARD_REGISTER (x))
4678 ("address of explicit register variable %qD requested", x);
4681 else if (extra_warnings)
4683 (OPT_Wextra, "address requested for %qD, which is declared %<register%>", x);
4685 TREE_ADDRESSABLE (x) = 1;
4689 TREE_ADDRESSABLE (x) = 1;
4693 TREE_ADDRESSABLE (x) = 1;
4697 TREE_ADDRESSABLE (x) = 1;
4698 cxx_mark_addressable (TREE_OPERAND (x, 0));
4706 /* Build and return a conditional expression IFEXP ? OP1 : OP2. */
4709 build_x_conditional_expr (tree ifexp, tree op1, tree op2)
4711 tree orig_ifexp = ifexp;
4712 tree orig_op1 = op1;
4713 tree orig_op2 = op2;
4716 if (processing_template_decl)
4718 /* The standard says that the expression is type-dependent if
4719 IFEXP is type-dependent, even though the eventual type of the
4720 expression doesn't dependent on IFEXP. */
4721 if (type_dependent_expression_p (ifexp)
4722 /* As a GNU extension, the middle operand may be omitted. */
4723 || (op1 && type_dependent_expression_p (op1))
4724 || type_dependent_expression_p (op2))
4725 return build_min_nt (COND_EXPR, ifexp, op1, op2);
4726 ifexp = build_non_dependent_expr (ifexp);
4728 op1 = build_non_dependent_expr (op1);
4729 op2 = build_non_dependent_expr (op2);
4732 expr = build_conditional_expr (ifexp, op1, op2);
4733 if (processing_template_decl && expr != error_mark_node)
4734 return build_min_non_dep (COND_EXPR, expr,
4735 orig_ifexp, orig_op1, orig_op2);
4739 /* Given a list of expressions, return a compound expression
4740 that performs them all and returns the value of the last of them. */
4742 tree build_x_compound_expr_from_list (tree list, const char *msg)
4744 tree expr = TREE_VALUE (list);
4746 if (TREE_CHAIN (list))
4749 pedwarn ("%s expression list treated as compound expression", msg);
4751 for (list = TREE_CHAIN (list); list; list = TREE_CHAIN (list))
4752 expr = build_x_compound_expr (expr, TREE_VALUE (list));
4758 /* Handle overloading of the ',' operator when needed. */
4761 build_x_compound_expr (tree op1, tree op2)
4764 tree orig_op1 = op1;
4765 tree orig_op2 = op2;
4767 if (processing_template_decl)
4769 if (type_dependent_expression_p (op1)
4770 || type_dependent_expression_p (op2))
4771 return build_min_nt (COMPOUND_EXPR, op1, op2);
4772 op1 = build_non_dependent_expr (op1);
4773 op2 = build_non_dependent_expr (op2);
4776 result = build_new_op (COMPOUND_EXPR, LOOKUP_NORMAL, op1, op2, NULL_TREE,
4777 /*overloaded_p=*/NULL);
4779 result = build_compound_expr (op1, op2);
4781 if (processing_template_decl && result != error_mark_node)
4782 return build_min_non_dep (COMPOUND_EXPR, result, orig_op1, orig_op2);
4787 /* Build a compound expression. */
4790 build_compound_expr (tree lhs, tree rhs)
4792 lhs = convert_to_void (lhs, "left-hand operand of comma");
4794 if (lhs == error_mark_node || rhs == error_mark_node)
4795 return error_mark_node;
4797 if (TREE_CODE (rhs) == TARGET_EXPR)
4799 /* If the rhs is a TARGET_EXPR, then build the compound
4800 expression inside the target_expr's initializer. This
4801 helps the compiler to eliminate unnecessary temporaries. */
4802 tree init = TREE_OPERAND (rhs, 1);
4804 init = build2 (COMPOUND_EXPR, TREE_TYPE (init), lhs, init);
4805 TREE_OPERAND (rhs, 1) = init;
4810 return build2 (COMPOUND_EXPR, TREE_TYPE (rhs), lhs, rhs);
4813 /* Issue a diagnostic message if casting from SRC_TYPE to DEST_TYPE
4814 casts away constness. DIAG_FN gives the function to call if we
4815 need to issue a diagnostic; if it is NULL, no diagnostic will be
4816 issued. DESCRIPTION explains what operation is taking place. */
4819 check_for_casting_away_constness (tree src_type, tree dest_type,
4820 void (*diag_fn)(const char *, ...) ATTRIBUTE_GCC_CXXDIAG(1,2),
4821 const char *description)
4823 if (diag_fn && casts_away_constness (src_type, dest_type))
4824 diag_fn ("%s from type %qT to type %qT casts away constness",
4825 description, src_type, dest_type);
4828 /* Convert EXPR (an expression with pointer-to-member type) to TYPE
4829 (another pointer-to-member type in the same hierarchy) and return
4830 the converted expression. If ALLOW_INVERSE_P is permitted, a
4831 pointer-to-derived may be converted to pointer-to-base; otherwise,
4832 only the other direction is permitted. If C_CAST_P is true, this
4833 conversion is taking place as part of a C-style cast. */
4836 convert_ptrmem (tree type, tree expr, bool allow_inverse_p,
4839 if (TYPE_PTRMEM_P (type))
4843 if (TREE_CODE (expr) == PTRMEM_CST)
4844 expr = cplus_expand_constant (expr);
4845 delta = get_delta_difference (TYPE_PTRMEM_CLASS_TYPE (TREE_TYPE (expr)),
4846 TYPE_PTRMEM_CLASS_TYPE (type),
4849 if (!integer_zerop (delta))
4850 expr = cp_build_binary_op (PLUS_EXPR,
4851 build_nop (ptrdiff_type_node, expr),
4853 return build_nop (type, expr);
4856 return build_ptrmemfunc (TYPE_PTRMEMFUNC_FN_TYPE (type), expr,
4857 allow_inverse_p, c_cast_p);
4860 /* If EXPR is an INTEGER_CST and ORIG is an arithmetic constant, return
4861 a version of EXPR that has TREE_OVERFLOW set if it is set in ORIG.
4862 Otherwise, return EXPR unchanged. */
4865 ignore_overflows (tree expr, tree orig)
4867 if (TREE_CODE (expr) == INTEGER_CST
4868 && CONSTANT_CLASS_P (orig)
4869 && TREE_CODE (orig) != STRING_CST
4870 && TREE_OVERFLOW (expr) != TREE_OVERFLOW (orig))
4872 if (!TREE_OVERFLOW (orig))
4873 /* Ensure constant sharing. */
4874 expr = build_int_cst_wide (TREE_TYPE (expr),
4875 TREE_INT_CST_LOW (expr),
4876 TREE_INT_CST_HIGH (expr));
4879 /* Avoid clobbering a shared constant. */
4880 expr = copy_node (expr);
4881 TREE_OVERFLOW (expr) = TREE_OVERFLOW (orig);
4887 /* Perform a static_cast from EXPR to TYPE. When C_CAST_P is true,
4888 this static_cast is being attempted as one of the possible casts
4889 allowed by a C-style cast. (In that case, accessibility of base
4890 classes is not considered, and it is OK to cast away
4891 constness.) Return the result of the cast. *VALID_P is set to
4892 indicate whether or not the cast was valid. */
4895 build_static_cast_1 (tree type, tree expr, bool c_cast_p,
4901 void (*diag_fn)(const char*, ...) ATTRIBUTE_GCC_CXXDIAG(1,2);
4904 /* Assume the cast is valid. */
4907 intype = TREE_TYPE (expr);
4909 /* Save casted types in the function's used types hash table. */
4910 used_types_insert (type);
4912 /* Determine what to do when casting away constness. */
4915 /* C-style casts are allowed to cast away constness. With
4916 WARN_CAST_QUAL, we still want to issue a warning. */
4917 diag_fn = warn_cast_qual ? warning0 : NULL;
4922 /* A static_cast may not cast away constness. */
4924 desc = "static_cast";
4927 /* [expr.static.cast]
4929 An lvalue of type "cv1 B", where B is a class type, can be cast
4930 to type "reference to cv2 D", where D is a class derived (clause
4931 _class.derived_) from B, if a valid standard conversion from
4932 "pointer to D" to "pointer to B" exists (_conv.ptr_), cv2 is the
4933 same cv-qualification as, or greater cv-qualification than, cv1,
4934 and B is not a virtual base class of D. */
4935 /* We check this case before checking the validity of "TYPE t =
4936 EXPR;" below because for this case:
4939 struct D : public B { D(const B&); };
4941 void f() { static_cast<const D&>(b); }
4943 we want to avoid constructing a new D. The standard is not
4944 completely clear about this issue, but our interpretation is
4945 consistent with other compilers. */
4946 if (TREE_CODE (type) == REFERENCE_TYPE
4947 && CLASS_TYPE_P (TREE_TYPE (type))
4948 && CLASS_TYPE_P (intype)
4949 && real_lvalue_p (expr)
4950 && DERIVED_FROM_P (intype, TREE_TYPE (type))
4951 && can_convert (build_pointer_type (TYPE_MAIN_VARIANT (intype)),
4952 build_pointer_type (TYPE_MAIN_VARIANT
4953 (TREE_TYPE (type))))
4955 || at_least_as_qualified_p (TREE_TYPE (type), intype)))
4959 /* There is a standard conversion from "D*" to "B*" even if "B"
4960 is ambiguous or inaccessible. If this is really a
4961 static_cast, then we check both for inaccessibility and
4962 ambiguity. However, if this is a static_cast being performed
4963 because the user wrote a C-style cast, then accessibility is
4965 base = lookup_base (TREE_TYPE (type), intype,
4966 c_cast_p ? ba_unique : ba_check,
4969 /* Convert from "B*" to "D*". This function will check that "B"
4970 is not a virtual base of "D". */
4971 expr = build_base_path (MINUS_EXPR, build_address (expr),
4972 base, /*nonnull=*/false);
4973 /* Convert the pointer to a reference -- but then remember that
4974 there are no expressions with reference type in C++. */
4975 return convert_from_reference (build_nop (type, expr));
4980 /* [expr.static.cast]
4982 An expression e can be explicitly converted to a type T using a
4983 static_cast of the form static_cast<T>(e) if the declaration T
4984 t(e);" is well-formed, for some invented temporary variable
4986 result = perform_direct_initialization_if_possible (type, expr,
4990 result = convert_from_reference (result);
4992 /* Ignore any integer overflow caused by the cast. */
4993 result = ignore_overflows (result, orig);
4995 /* [expr.static.cast]
4997 If T is a reference type, the result is an lvalue; otherwise,
4998 the result is an rvalue. */
4999 if (TREE_CODE (type) != REFERENCE_TYPE)
5000 result = rvalue (result);
5004 /* [expr.static.cast]
5006 Any expression can be explicitly converted to type cv void. */
5007 if (TREE_CODE (type) == VOID_TYPE)
5008 return convert_to_void (expr, /*implicit=*/NULL);
5010 /* [expr.static.cast]
5012 The inverse of any standard conversion sequence (clause _conv_),
5013 other than the lvalue-to-rvalue (_conv.lval_), array-to-pointer
5014 (_conv.array_), function-to-pointer (_conv.func_), and boolean
5015 (_conv.bool_) conversions, can be performed explicitly using
5016 static_cast subject to the restriction that the explicit
5017 conversion does not cast away constness (_expr.const.cast_), and
5018 the following additional rules for specific cases: */
5019 /* For reference, the conversions not excluded are: integral
5020 promotions, floating point promotion, integral conversions,
5021 floating point conversions, floating-integral conversions,
5022 pointer conversions, and pointer to member conversions. */
5025 A value of integral _or enumeration_ type can be explicitly
5026 converted to an enumeration type. */
5027 /* The effect of all that is that any conversion between any two
5028 types which are integral, floating, or enumeration types can be
5030 if ((INTEGRAL_TYPE_P (type) || SCALAR_FLOAT_TYPE_P (type))
5031 && (INTEGRAL_TYPE_P (intype) || SCALAR_FLOAT_TYPE_P (intype)))
5033 expr = ocp_convert (type, expr, CONV_C_CAST, LOOKUP_NORMAL);
5035 /* Ignore any integer overflow caused by the cast. */
5036 expr = ignore_overflows (expr, orig);
5040 if (TYPE_PTR_P (type) && TYPE_PTR_P (intype)
5041 && CLASS_TYPE_P (TREE_TYPE (type))
5042 && CLASS_TYPE_P (TREE_TYPE (intype))
5043 && can_convert (build_pointer_type (TYPE_MAIN_VARIANT
5044 (TREE_TYPE (intype))),
5045 build_pointer_type (TYPE_MAIN_VARIANT
5046 (TREE_TYPE (type)))))
5051 check_for_casting_away_constness (intype, type, diag_fn, desc);
5052 base = lookup_base (TREE_TYPE (type), TREE_TYPE (intype),
5053 c_cast_p ? ba_unique : ba_check,
5055 return build_base_path (MINUS_EXPR, expr, base, /*nonnull=*/false);
5058 if ((TYPE_PTRMEM_P (type) && TYPE_PTRMEM_P (intype))
5059 || (TYPE_PTRMEMFUNC_P (type) && TYPE_PTRMEMFUNC_P (intype)))
5066 c1 = TYPE_PTRMEM_CLASS_TYPE (intype);
5067 c2 = TYPE_PTRMEM_CLASS_TYPE (type);
5069 if (TYPE_PTRMEM_P (type))
5071 t1 = (build_ptrmem_type
5073 TYPE_MAIN_VARIANT (TYPE_PTRMEM_POINTED_TO_TYPE (intype))));
5074 t2 = (build_ptrmem_type
5076 TYPE_MAIN_VARIANT (TYPE_PTRMEM_POINTED_TO_TYPE (type))));
5083 if (can_convert (t1, t2))
5086 check_for_casting_away_constness (intype, type, diag_fn,
5088 return convert_ptrmem (type, expr, /*allow_inverse_p=*/1,
5093 /* [expr.static.cast]
5095 An rvalue of type "pointer to cv void" can be explicitly
5096 converted to a pointer to object type. A value of type pointer
5097 to object converted to "pointer to cv void" and back to the
5098 original pointer type will have its original value. */
5099 if (TREE_CODE (intype) == POINTER_TYPE
5100 && VOID_TYPE_P (TREE_TYPE (intype))
5101 && TYPE_PTROB_P (type))
5104 check_for_casting_away_constness (intype, type, diag_fn, desc);
5105 return build_nop (type, expr);
5109 return error_mark_node;
5112 /* Return an expression representing static_cast<TYPE>(EXPR). */
5115 build_static_cast (tree type, tree expr)
5120 if (type == error_mark_node || expr == error_mark_node)
5121 return error_mark_node;
5123 if (processing_template_decl)
5125 expr = build_min (STATIC_CAST_EXPR, type, expr);
5126 /* We don't know if it will or will not have side effects. */
5127 TREE_SIDE_EFFECTS (expr) = 1;
5128 return convert_from_reference (expr);
5131 /* build_c_cast puts on a NOP_EXPR to make the result not an lvalue.
5132 Strip such NOP_EXPRs if VALUE is being used in non-lvalue context. */
5133 if (TREE_CODE (type) != REFERENCE_TYPE
5134 && TREE_CODE (expr) == NOP_EXPR
5135 && TREE_TYPE (expr) == TREE_TYPE (TREE_OPERAND (expr, 0)))
5136 expr = TREE_OPERAND (expr, 0);
5138 result = build_static_cast_1 (type, expr, /*c_cast_p=*/false, &valid_p);
5142 error ("invalid static_cast from type %qT to type %qT",
5143 TREE_TYPE (expr), type);
5144 return error_mark_node;
5147 /* EXPR is an expression with member function or pointer-to-member
5148 function type. TYPE is a pointer type. Converting EXPR to TYPE is
5149 not permitted by ISO C++, but we accept it in some modes. If we
5150 are not in one of those modes, issue a diagnostic. Return the
5151 converted expression. */
5154 convert_member_func_to_ptr (tree type, tree expr)
5159 intype = TREE_TYPE (expr);
5160 gcc_assert (TYPE_PTRMEMFUNC_P (intype)
5161 || TREE_CODE (intype) == METHOD_TYPE);
5163 if (pedantic || warn_pmf2ptr)
5164 pedwarn ("converting from %qT to %qT", intype, type);
5166 if (TREE_CODE (intype) == METHOD_TYPE)
5167 expr = build_addr_func (expr);
5168 else if (TREE_CODE (expr) == PTRMEM_CST)
5169 expr = build_address (PTRMEM_CST_MEMBER (expr));
5172 decl = maybe_dummy_object (TYPE_PTRMEM_CLASS_TYPE (intype), 0);
5173 decl = build_address (decl);
5174 expr = get_member_function_from_ptrfunc (&decl, expr);
5177 return build_nop (type, expr);
5180 /* Return a representation for a reinterpret_cast from EXPR to TYPE.
5181 If C_CAST_P is true, this reinterpret cast is being done as part of
5182 a C-style cast. If VALID_P is non-NULL, *VALID_P is set to
5183 indicate whether or not reinterpret_cast was valid. */
5186 build_reinterpret_cast_1 (tree type, tree expr, bool c_cast_p,
5191 /* Assume the cast is invalid. */
5195 if (type == error_mark_node || error_operand_p (expr))
5196 return error_mark_node;
5198 intype = TREE_TYPE (expr);
5200 /* Save casted types in the function's used types hash table. */
5201 used_types_insert (type);
5203 /* [expr.reinterpret.cast]
5204 An lvalue expression of type T1 can be cast to the type
5205 "reference to T2" if an expression of type "pointer to T1" can be
5206 explicitly converted to the type "pointer to T2" using a
5207 reinterpret_cast. */
5208 if (TREE_CODE (type) == REFERENCE_TYPE)
5210 if (! real_lvalue_p (expr))
5212 error ("invalid cast of an rvalue expression of type "
5215 return error_mark_node;
5218 /* Warn about a reinterpret_cast from "A*" to "B&" if "A" and
5219 "B" are related class types; the reinterpret_cast does not
5220 adjust the pointer. */
5221 if (TYPE_PTR_P (intype)
5222 && (comptypes (TREE_TYPE (intype), TREE_TYPE (type),
5223 COMPARE_BASE | COMPARE_DERIVED)))
5224 warning (0, "casting %qT to %qT does not dereference pointer",
5227 expr = build_unary_op (ADDR_EXPR, expr, 0);
5228 if (expr != error_mark_node)
5229 expr = build_reinterpret_cast_1
5230 (build_pointer_type (TREE_TYPE (type)), expr, c_cast_p,
5232 if (expr != error_mark_node)
5233 expr = build_indirect_ref (expr, 0);
5237 /* As a G++ extension, we consider conversions from member
5238 functions, and pointers to member functions to
5239 pointer-to-function and pointer-to-void types. If
5240 -Wno-pmf-conversions has not been specified,
5241 convert_member_func_to_ptr will issue an error message. */
5242 if ((TYPE_PTRMEMFUNC_P (intype)
5243 || TREE_CODE (intype) == METHOD_TYPE)
5244 && TYPE_PTR_P (type)
5245 && (TREE_CODE (TREE_TYPE (type)) == FUNCTION_TYPE
5246 || VOID_TYPE_P (TREE_TYPE (type))))
5247 return convert_member_func_to_ptr (type, expr);
5249 /* If the cast is not to a reference type, the lvalue-to-rvalue,
5250 array-to-pointer, and function-to-pointer conversions are
5252 expr = decay_conversion (expr);
5254 /* build_c_cast puts on a NOP_EXPR to make the result not an lvalue.
5255 Strip such NOP_EXPRs if VALUE is being used in non-lvalue context. */
5256 if (TREE_CODE (expr) == NOP_EXPR
5257 && TREE_TYPE (expr) == TREE_TYPE (TREE_OPERAND (expr, 0)))
5258 expr = TREE_OPERAND (expr, 0);
5260 if (error_operand_p (expr))
5261 return error_mark_node;
5263 intype = TREE_TYPE (expr);
5265 /* [expr.reinterpret.cast]
5266 A pointer can be converted to any integral type large enough to
5268 if (CP_INTEGRAL_TYPE_P (type) && TYPE_PTR_P (intype))
5270 if (TYPE_PRECISION (type) < TYPE_PRECISION (intype))
5271 pedwarn ("cast from %qT to %qT loses precision",
5274 /* [expr.reinterpret.cast]
5275 A value of integral or enumeration type can be explicitly
5276 converted to a pointer. */
5277 else if (TYPE_PTR_P (type) && INTEGRAL_OR_ENUMERATION_TYPE_P (intype))
5280 else if ((TYPE_PTRFN_P (type) && TYPE_PTRFN_P (intype))
5281 || (TYPE_PTRMEMFUNC_P (type) && TYPE_PTRMEMFUNC_P (intype)))
5282 return fold_if_not_in_template (build_nop (type, expr));
5283 else if ((TYPE_PTRMEM_P (type) && TYPE_PTRMEM_P (intype))
5284 || (TYPE_PTROBV_P (type) && TYPE_PTROBV_P (intype)))
5289 check_for_casting_away_constness (intype, type, error,
5290 "reinterpret_cast");
5291 /* Warn about possible alignment problems. */
5292 if (STRICT_ALIGNMENT && warn_cast_align
5293 && !VOID_TYPE_P (type)
5294 && TREE_CODE (TREE_TYPE (intype)) != FUNCTION_TYPE
5295 && COMPLETE_TYPE_P (TREE_TYPE (type))
5296 && COMPLETE_TYPE_P (TREE_TYPE (intype))
5297 && TYPE_ALIGN (TREE_TYPE (type)) > TYPE_ALIGN (TREE_TYPE (intype)))
5298 warning (0, "cast from %qT to %qT increases required alignment of "
5302 /* We need to strip nops here, because the front end likes to
5303 create (int *)&a for array-to-pointer decay, instead of &a[0]. */
5305 if (warn_strict_aliasing <= 2)
5306 strict_aliasing_warning (intype, type, sexpr);
5308 return fold_if_not_in_template (build_nop (type, expr));
5310 else if ((TYPE_PTRFN_P (type) && TYPE_PTROBV_P (intype))
5311 || (TYPE_PTRFN_P (intype) && TYPE_PTROBV_P (type)))
5314 /* Only issue a warning, as we have always supported this
5315 where possible, and it is necessary in some cases. DR 195
5316 addresses this issue, but as of 2004/10/26 is still in
5318 warning (0, "ISO C++ forbids casting between pointer-to-function and pointer-to-object");
5319 return fold_if_not_in_template (build_nop (type, expr));
5321 else if (TREE_CODE (type) == VECTOR_TYPE)
5322 return fold_if_not_in_template (convert_to_vector (type, expr));
5323 else if (TREE_CODE (intype) == VECTOR_TYPE && INTEGRAL_TYPE_P (type))
5324 return fold_if_not_in_template (convert_to_integer (type, expr));
5329 error ("invalid cast from type %qT to type %qT", intype, type);
5330 return error_mark_node;
5333 return cp_convert (type, expr);
5337 build_reinterpret_cast (tree type, tree expr)
5339 if (type == error_mark_node || expr == error_mark_node)
5340 return error_mark_node;
5342 if (processing_template_decl)
5344 tree t = build_min (REINTERPRET_CAST_EXPR, type, expr);
5346 if (!TREE_SIDE_EFFECTS (t)
5347 && type_dependent_expression_p (expr))
5348 /* There might turn out to be side effects inside expr. */
5349 TREE_SIDE_EFFECTS (t) = 1;
5350 return convert_from_reference (t);
5353 return build_reinterpret_cast_1 (type, expr, /*c_cast_p=*/false,
5357 /* Perform a const_cast from EXPR to TYPE. If the cast is valid,
5358 return an appropriate expression. Otherwise, return
5359 error_mark_node. If the cast is not valid, and COMPLAIN is true,
5360 then a diagnostic will be issued. If VALID_P is non-NULL, we are
5361 performing a C-style cast, its value upon return will indicate
5362 whether or not the conversion succeeded. */
5365 build_const_cast_1 (tree dst_type, tree expr, bool complain,
5369 tree reference_type;
5371 /* Callers are responsible for handling error_mark_node as a
5372 destination type. */
5373 gcc_assert (dst_type != error_mark_node);
5374 /* In a template, callers should be building syntactic
5375 representations of casts, not using this machinery. */
5376 gcc_assert (!processing_template_decl);
5378 /* Assume the conversion is invalid. */
5382 if (!POINTER_TYPE_P (dst_type) && !TYPE_PTRMEM_P (dst_type))
5385 error ("invalid use of const_cast with type %qT, "
5386 "which is not a pointer, "
5387 "reference, nor a pointer-to-data-member type", dst_type);
5388 return error_mark_node;
5391 if (TREE_CODE (TREE_TYPE (dst_type)) == FUNCTION_TYPE)
5394 error ("invalid use of const_cast with type %qT, which is a pointer "
5395 "or reference to a function type", dst_type);
5396 return error_mark_node;
5399 /* Save casted types in the function's used types hash table. */
5400 used_types_insert (dst_type);
5402 src_type = TREE_TYPE (expr);
5403 /* Expressions do not really have reference types. */
5404 if (TREE_CODE (src_type) == REFERENCE_TYPE)
5405 src_type = TREE_TYPE (src_type);
5407 /* [expr.const.cast]
5409 An lvalue of type T1 can be explicitly converted to an lvalue of
5410 type T2 using the cast const_cast<T2&> (where T1 and T2 are object
5411 types) if a pointer to T1 can be explicitly converted to the type
5412 pointer to T2 using a const_cast. */
5413 if (TREE_CODE (dst_type) == REFERENCE_TYPE)
5415 reference_type = dst_type;
5416 if (! real_lvalue_p (expr))
5419 error ("invalid const_cast of an rvalue of type %qT to type %qT",
5420 src_type, dst_type);
5421 return error_mark_node;
5423 dst_type = build_pointer_type (TREE_TYPE (dst_type));
5424 src_type = build_pointer_type (src_type);
5428 reference_type = NULL_TREE;
5429 /* If the destination type is not a reference type, the
5430 lvalue-to-rvalue, array-to-pointer, and function-to-pointer
5431 conversions are performed. */
5432 src_type = type_decays_to (src_type);
5433 if (src_type == error_mark_node)
5434 return error_mark_node;
5437 if ((TYPE_PTR_P (src_type) || TYPE_PTRMEM_P (src_type))
5438 && comp_ptr_ttypes_const (dst_type, src_type))
5443 /* This cast is actually a C-style cast. Issue a warning if
5444 the user is making a potentially unsafe cast. */
5446 check_for_casting_away_constness (src_type, dst_type,
5452 expr = build_unary_op (ADDR_EXPR, expr, 0);
5453 expr = build_nop (reference_type, expr);
5454 return convert_from_reference (expr);
5458 expr = decay_conversion (expr);
5459 /* build_c_cast puts on a NOP_EXPR to make the result not an
5460 lvalue. Strip such NOP_EXPRs if VALUE is being used in
5461 non-lvalue context. */
5462 if (TREE_CODE (expr) == NOP_EXPR
5463 && TREE_TYPE (expr) == TREE_TYPE (TREE_OPERAND (expr, 0)))
5464 expr = TREE_OPERAND (expr, 0);
5465 return build_nop (dst_type, expr);
5470 error ("invalid const_cast from type %qT to type %qT",
5471 src_type, dst_type);
5472 return error_mark_node;
5476 build_const_cast (tree type, tree expr)
5478 if (type == error_mark_node || error_operand_p (expr))
5479 return error_mark_node;
5481 if (processing_template_decl)
5483 tree t = build_min (CONST_CAST_EXPR, type, expr);
5485 if (!TREE_SIDE_EFFECTS (t)
5486 && type_dependent_expression_p (expr))
5487 /* There might turn out to be side effects inside expr. */
5488 TREE_SIDE_EFFECTS (t) = 1;
5489 return convert_from_reference (t);
5492 return build_const_cast_1 (type, expr, /*complain=*/true,
5496 /* Build an expression representing an explicit C-style cast to type
5497 TYPE of expression EXPR. */
5500 build_c_cast (tree type, tree expr)
5506 if (type == error_mark_node || error_operand_p (expr))
5507 return error_mark_node;
5509 if (processing_template_decl)
5511 tree t = build_min (CAST_EXPR, type,
5512 tree_cons (NULL_TREE, value, NULL_TREE));
5513 /* We don't know if it will or will not have side effects. */
5514 TREE_SIDE_EFFECTS (t) = 1;
5515 return convert_from_reference (t);
5518 /* Casts to a (pointer to a) specific ObjC class (or 'id' or
5519 'Class') should always be retained, because this information aids
5520 in method lookup. */
5521 if (objc_is_object_ptr (type)
5522 && objc_is_object_ptr (TREE_TYPE (expr)))
5523 return build_nop (type, expr);
5525 /* build_c_cast puts on a NOP_EXPR to make the result not an lvalue.
5526 Strip such NOP_EXPRs if VALUE is being used in non-lvalue context. */
5527 if (TREE_CODE (type) != REFERENCE_TYPE
5528 && TREE_CODE (value) == NOP_EXPR
5529 && TREE_TYPE (value) == TREE_TYPE (TREE_OPERAND (value, 0)))
5530 value = TREE_OPERAND (value, 0);
5532 if (TREE_CODE (type) == ARRAY_TYPE)
5534 /* Allow casting from T1* to T2[] because Cfront allows it.
5535 NIHCL uses it. It is not valid ISO C++ however. */
5536 if (TREE_CODE (TREE_TYPE (expr)) == POINTER_TYPE)
5538 pedwarn ("ISO C++ forbids casting to an array type %qT", type);
5539 type = build_pointer_type (TREE_TYPE (type));
5543 error ("ISO C++ forbids casting to an array type %qT", type);
5544 return error_mark_node;
5548 if (TREE_CODE (type) == FUNCTION_TYPE
5549 || TREE_CODE (type) == METHOD_TYPE)
5551 error ("invalid cast to function type %qT", type);
5552 return error_mark_node;
5555 /* A C-style cast can be a const_cast. */
5556 result = build_const_cast_1 (type, value, /*complain=*/false,
5561 /* Or a static cast. */
5562 result = build_static_cast_1 (type, value, /*c_cast_p=*/true,
5564 /* Or a reinterpret_cast. */
5566 result = build_reinterpret_cast_1 (type, value, /*c_cast_p=*/true,
5568 /* The static_cast or reinterpret_cast may be followed by a
5571 /* A valid cast may result in errors if, for example, a
5572 conversion to am ambiguous base class is required. */
5573 && !error_operand_p (result))
5577 /* Non-class rvalues always have cv-unqualified type. */
5578 if (!CLASS_TYPE_P (type))
5579 type = TYPE_MAIN_VARIANT (type);
5580 result_type = TREE_TYPE (result);
5581 if (!CLASS_TYPE_P (result_type))
5582 result_type = TYPE_MAIN_VARIANT (result_type);
5583 /* If the type of RESULT does not match TYPE, perform a
5584 const_cast to make it match. If the static_cast or
5585 reinterpret_cast succeeded, we will differ by at most
5586 cv-qualification, so the follow-on const_cast is guaranteed
5588 if (!same_type_p (non_reference (type), non_reference (result_type)))
5590 result = build_const_cast_1 (type, result, false, &valid_p);
5591 gcc_assert (valid_p);
5596 return error_mark_node;
5599 /* Build an assignment expression of lvalue LHS from value RHS.
5600 MODIFYCODE is the code for a binary operator that we use
5601 to combine the old value of LHS with RHS to get the new value.
5602 Or else MODIFYCODE is NOP_EXPR meaning do a simple assignment.
5604 C++: If MODIFYCODE is INIT_EXPR, then leave references unbashed. */
5607 build_modify_expr (tree lhs, enum tree_code modifycode, tree rhs)
5611 tree lhstype = TREE_TYPE (lhs);
5612 tree olhstype = lhstype;
5613 tree olhs = NULL_TREE;
5614 bool plain_assign = (modifycode == NOP_EXPR);
5616 /* Avoid duplicate error messages from operands that had errors. */
5617 if (error_operand_p (lhs) || error_operand_p (rhs))
5618 return error_mark_node;
5620 /* Handle control structure constructs used as "lvalues". */
5621 switch (TREE_CODE (lhs))
5623 /* Handle --foo = 5; as these are valid constructs in C++. */
5624 case PREDECREMENT_EXPR:
5625 case PREINCREMENT_EXPR:
5626 if (TREE_SIDE_EFFECTS (TREE_OPERAND (lhs, 0)))
5627 lhs = build2 (TREE_CODE (lhs), TREE_TYPE (lhs),
5628 stabilize_reference (TREE_OPERAND (lhs, 0)),
5629 TREE_OPERAND (lhs, 1));
5630 return build2 (COMPOUND_EXPR, lhstype,
5632 build_modify_expr (TREE_OPERAND (lhs, 0),
5635 /* Handle (a, b) used as an "lvalue". */
5637 newrhs = build_modify_expr (TREE_OPERAND (lhs, 1),
5639 if (newrhs == error_mark_node)
5640 return error_mark_node;
5641 return build2 (COMPOUND_EXPR, lhstype,
5642 TREE_OPERAND (lhs, 0), newrhs);
5645 if (TREE_SIDE_EFFECTS (TREE_OPERAND (lhs, 0)))
5646 lhs = build2 (TREE_CODE (lhs), TREE_TYPE (lhs),
5647 stabilize_reference (TREE_OPERAND (lhs, 0)),
5648 TREE_OPERAND (lhs, 1));
5649 newrhs = build_modify_expr (TREE_OPERAND (lhs, 0), modifycode, rhs);
5650 if (newrhs == error_mark_node)
5651 return error_mark_node;
5652 return build2 (COMPOUND_EXPR, lhstype, lhs, newrhs);
5656 /* MIN_EXPR and MAX_EXPR are currently only permitted as lvalues,
5657 when neither operand has side-effects. */
5658 if (!lvalue_or_else (lhs, lv_assign))
5659 return error_mark_node;
5661 gcc_assert (!TREE_SIDE_EFFECTS (TREE_OPERAND (lhs, 0))
5662 && !TREE_SIDE_EFFECTS (TREE_OPERAND (lhs, 1)));
5664 lhs = build3 (COND_EXPR, TREE_TYPE (lhs),
5665 build2 (TREE_CODE (lhs) == MIN_EXPR ? LE_EXPR : GE_EXPR,
5667 TREE_OPERAND (lhs, 0),
5668 TREE_OPERAND (lhs, 1)),
5669 TREE_OPERAND (lhs, 0),
5670 TREE_OPERAND (lhs, 1));
5673 /* Handle (a ? b : c) used as an "lvalue". */
5676 /* Produce (a ? (b = rhs) : (c = rhs))
5677 except that the RHS goes through a save-expr
5678 so the code to compute it is only emitted once. */
5680 tree preeval = NULL_TREE;
5682 if (VOID_TYPE_P (TREE_TYPE (rhs)))
5684 error ("void value not ignored as it ought to be");
5685 return error_mark_node;
5688 rhs = stabilize_expr (rhs, &preeval);
5690 /* Check this here to avoid odd errors when trying to convert
5691 a throw to the type of the COND_EXPR. */
5692 if (!lvalue_or_else (lhs, lv_assign))
5693 return error_mark_node;
5695 cond = build_conditional_expr
5696 (TREE_OPERAND (lhs, 0),
5697 build_modify_expr (TREE_OPERAND (lhs, 1),
5699 build_modify_expr (TREE_OPERAND (lhs, 2),
5702 if (cond == error_mark_node)
5704 /* Make sure the code to compute the rhs comes out
5705 before the split. */
5707 cond = build2 (COMPOUND_EXPR, TREE_TYPE (lhs), preeval, cond);
5715 if (modifycode == INIT_EXPR)
5717 if (TREE_CODE (rhs) == CONSTRUCTOR)
5719 if (! same_type_p (TREE_TYPE (rhs), lhstype))
5720 /* Call convert to generate an error; see PR 11063. */
5721 rhs = convert (lhstype, rhs);
5722 result = build2 (INIT_EXPR, lhstype, lhs, rhs);
5723 TREE_SIDE_EFFECTS (result) = 1;
5726 else if (! IS_AGGR_TYPE (lhstype))
5727 /* Do the default thing. */;
5730 result = build_special_member_call (lhs, complete_ctor_identifier,
5731 build_tree_list (NULL_TREE, rhs),
5732 lhstype, LOOKUP_NORMAL);
5733 if (result == NULL_TREE)
5734 return error_mark_node;
5740 lhs = require_complete_type (lhs);
5741 if (lhs == error_mark_node)
5742 return error_mark_node;
5744 if (modifycode == NOP_EXPR)
5746 /* `operator=' is not an inheritable operator. */
5747 if (! IS_AGGR_TYPE (lhstype))
5748 /* Do the default thing. */;
5751 result = build_new_op (MODIFY_EXPR, LOOKUP_NORMAL,
5752 lhs, rhs, make_node (NOP_EXPR),
5753 /*overloaded_p=*/NULL);
5754 if (result == NULL_TREE)
5755 return error_mark_node;
5762 /* A binary op has been requested. Combine the old LHS
5763 value with the RHS producing the value we should actually
5764 store into the LHS. */
5766 gcc_assert (!PROMOTES_TO_AGGR_TYPE (lhstype, REFERENCE_TYPE));
5767 lhs = stabilize_reference (lhs);
5768 newrhs = cp_build_binary_op (modifycode, lhs, rhs);
5769 if (newrhs == error_mark_node)
5771 error (" in evaluation of %<%Q(%#T, %#T)%>", modifycode,
5772 TREE_TYPE (lhs), TREE_TYPE (rhs));
5773 return error_mark_node;
5776 /* Now it looks like a plain assignment. */
5777 modifycode = NOP_EXPR;
5779 gcc_assert (TREE_CODE (lhstype) != REFERENCE_TYPE);
5780 gcc_assert (TREE_CODE (TREE_TYPE (newrhs)) != REFERENCE_TYPE);
5783 /* The left-hand side must be an lvalue. */
5784 if (!lvalue_or_else (lhs, lv_assign))
5785 return error_mark_node;
5787 /* Warn about modifying something that is `const'. Don't warn if
5788 this is initialization. */
5789 if (modifycode != INIT_EXPR
5790 && (TREE_READONLY (lhs) || CP_TYPE_CONST_P (lhstype)
5791 /* Functions are not modifiable, even though they are
5793 || TREE_CODE (TREE_TYPE (lhs)) == FUNCTION_TYPE
5794 || TREE_CODE (TREE_TYPE (lhs)) == METHOD_TYPE
5795 /* If it's an aggregate and any field is const, then it is
5796 effectively const. */
5797 || (CLASS_TYPE_P (lhstype)
5798 && C_TYPE_FIELDS_READONLY (lhstype))))
5799 readonly_error (lhs, "assignment");
5801 /* If storing into a structure or union member, it has probably been
5802 given type `int'. Compute the type that would go with the actual
5803 amount of storage the member occupies. */
5805 if (TREE_CODE (lhs) == COMPONENT_REF
5806 && (TREE_CODE (lhstype) == INTEGER_TYPE
5807 || TREE_CODE (lhstype) == REAL_TYPE
5808 || TREE_CODE (lhstype) == ENUMERAL_TYPE))
5810 lhstype = TREE_TYPE (get_unwidened (lhs, 0));
5812 /* If storing in a field that is in actuality a short or narrower
5813 than one, we must store in the field in its actual type. */
5815 if (lhstype != TREE_TYPE (lhs))
5817 /* Avoid warnings converting integral types back into enums for
5819 if (TREE_CODE (lhstype) == INTEGER_TYPE
5820 && TREE_CODE (olhstype) == ENUMERAL_TYPE)
5822 if (TREE_SIDE_EFFECTS (lhs))
5823 lhs = stabilize_reference (lhs);
5826 lhs = copy_node (lhs);
5827 TREE_TYPE (lhs) = lhstype;
5831 /* Convert new value to destination type. */
5833 if (TREE_CODE (lhstype) == ARRAY_TYPE)
5837 if (!same_or_base_type_p (TYPE_MAIN_VARIANT (lhstype),
5838 TYPE_MAIN_VARIANT (TREE_TYPE (rhs))))
5840 error ("incompatible types in assignment of %qT to %qT",
5841 TREE_TYPE (rhs), lhstype);
5842 return error_mark_node;
5845 /* Allow array assignment in compiler-generated code. */
5846 if (! DECL_ARTIFICIAL (current_function_decl))
5848 /* This routine is used for both initialization and assignment.
5849 Make sure the diagnostic message differentiates the context. */
5850 if (modifycode == INIT_EXPR)
5851 error ("array used as initializer");
5853 error ("invalid array assignment");
5854 return error_mark_node;
5857 from_array = TREE_CODE (TREE_TYPE (newrhs)) == ARRAY_TYPE
5858 ? 1 + (modifycode != INIT_EXPR): 0;
5859 return build_vec_init (lhs, NULL_TREE, newrhs,
5860 /*explicit_default_init_p=*/false,
5864 if (modifycode == INIT_EXPR)
5865 newrhs = convert_for_initialization (lhs, lhstype, newrhs, LOOKUP_NORMAL,
5866 "initialization", NULL_TREE, 0);
5869 /* Avoid warnings on enum bit fields. */
5870 if (TREE_CODE (olhstype) == ENUMERAL_TYPE
5871 && TREE_CODE (lhstype) == INTEGER_TYPE)
5873 newrhs = convert_for_assignment (olhstype, newrhs, "assignment",
5875 newrhs = convert_force (lhstype, newrhs, 0);
5878 newrhs = convert_for_assignment (lhstype, newrhs, "assignment",
5880 if (TREE_CODE (newrhs) == CALL_EXPR
5881 && TYPE_NEEDS_CONSTRUCTING (lhstype))
5882 newrhs = build_cplus_new (lhstype, newrhs);
5884 /* Can't initialize directly from a TARGET_EXPR, since that would
5885 cause the lhs to be constructed twice, and possibly result in
5886 accidental self-initialization. So we force the TARGET_EXPR to be
5887 expanded without a target. */
5888 if (TREE_CODE (newrhs) == TARGET_EXPR)
5889 newrhs = build2 (COMPOUND_EXPR, TREE_TYPE (newrhs), newrhs,
5890 TREE_OPERAND (newrhs, 0));
5893 if (newrhs == error_mark_node)
5894 return error_mark_node;
5896 if (c_dialect_objc () && flag_objc_gc)
5898 result = objc_generate_write_barrier (lhs, modifycode, newrhs);
5904 result = build2 (modifycode == NOP_EXPR ? MODIFY_EXPR : INIT_EXPR,
5905 lhstype, lhs, newrhs);
5907 TREE_SIDE_EFFECTS (result) = 1;
5909 TREE_NO_WARNING (result) = 1;
5911 /* If we got the LHS in a different type for storing in,
5912 convert the result back to the nominal type of LHS
5913 so that the value we return always has the same type
5914 as the LHS argument. */
5916 if (olhstype == TREE_TYPE (result))
5920 result = build2 (COMPOUND_EXPR, olhstype, result, olhs);
5921 TREE_NO_WARNING (result) = 1;
5924 return convert_for_assignment (olhstype, result, "assignment",
5929 build_x_modify_expr (tree lhs, enum tree_code modifycode, tree rhs)
5931 if (processing_template_decl)
5932 return build_min_nt (MODOP_EXPR, lhs,
5933 build_min_nt (modifycode, NULL_TREE, NULL_TREE), rhs);
5935 if (modifycode != NOP_EXPR)
5937 tree rval = build_new_op (MODIFY_EXPR, LOOKUP_NORMAL, lhs, rhs,
5938 make_node (modifycode),
5939 /*overloaded_p=*/NULL);
5942 TREE_NO_WARNING (rval) = 1;
5946 return build_modify_expr (lhs, modifycode, rhs);
5950 /* Get difference in deltas for different pointer to member function
5951 types. Returns an integer constant of type PTRDIFF_TYPE_NODE. If
5952 the conversion is invalid, the constant is zero. If
5953 ALLOW_INVERSE_P is true, then allow reverse conversions as well.
5954 If C_CAST_P is true this conversion is taking place as part of a
5957 Note that the naming of FROM and TO is kind of backwards; the return
5958 value is what we add to a TO in order to get a FROM. They are named
5959 this way because we call this function to find out how to convert from
5960 a pointer to member of FROM to a pointer to member of TO. */
5963 get_delta_difference (tree from, tree to,
5964 bool allow_inverse_p,
5971 /* Assume no conversion is required. */
5972 result = integer_zero_node;
5973 binfo = lookup_base (to, from, c_cast_p ? ba_unique : ba_check, &kind);
5974 if (kind == bk_inaccessible || kind == bk_ambig)
5975 error (" in pointer to member function conversion");
5978 if (kind != bk_via_virtual)
5979 result = BINFO_OFFSET (binfo);
5982 tree virt_binfo = binfo_from_vbase (binfo);
5984 /* This is a reinterpret cast, we choose to do nothing. */
5985 if (allow_inverse_p)
5986 warning (0, "pointer to member cast via virtual base %qT",
5987 BINFO_TYPE (virt_binfo));
5989 error ("pointer to member conversion via virtual base %qT",
5990 BINFO_TYPE (virt_binfo));
5993 else if (same_type_ignoring_top_level_qualifiers_p (from, to))
5994 /* Pointer to member of incomplete class is permitted*/;
5995 else if (!allow_inverse_p)
5997 error_not_base_type (from, to);
5998 error (" in pointer to member conversion");
6002 binfo = lookup_base (from, to, c_cast_p ? ba_unique : ba_check, &kind);
6005 if (kind != bk_via_virtual)
6006 result = size_diffop (size_zero_node, BINFO_OFFSET (binfo));
6009 /* This is a reinterpret cast, we choose to do nothing. */
6010 tree virt_binfo = binfo_from_vbase (binfo);
6012 warning (0, "pointer to member cast via virtual base %qT",
6013 BINFO_TYPE (virt_binfo));
6018 return fold_if_not_in_template (convert_to_integer (ptrdiff_type_node,
6022 /* Return a constructor for the pointer-to-member-function TYPE using
6023 the other components as specified. */
6026 build_ptrmemfunc1 (tree type, tree delta, tree pfn)
6031 VEC(constructor_elt, gc) *v;
6033 /* Pull the FIELD_DECLs out of the type. */
6034 pfn_field = TYPE_FIELDS (type);
6035 delta_field = TREE_CHAIN (pfn_field);
6037 /* Make sure DELTA has the type we want. */
6038 delta = convert_and_check (delta_type_node, delta);
6040 /* Finish creating the initializer. */
6041 v = VEC_alloc(constructor_elt, gc, 2);
6042 CONSTRUCTOR_APPEND_ELT(v, pfn_field, pfn);
6043 CONSTRUCTOR_APPEND_ELT(v, delta_field, delta);
6044 u = build_constructor (type, v);
6045 TREE_CONSTANT (u) = TREE_CONSTANT (pfn) & TREE_CONSTANT (delta);
6046 TREE_INVARIANT (u) = TREE_INVARIANT (pfn) & TREE_INVARIANT (delta);
6047 TREE_STATIC (u) = (TREE_CONSTANT (u)
6048 && (initializer_constant_valid_p (pfn, TREE_TYPE (pfn))
6050 && (initializer_constant_valid_p (delta, TREE_TYPE (delta))
6055 /* Build a constructor for a pointer to member function. It can be
6056 used to initialize global variables, local variable, or used
6057 as a value in expressions. TYPE is the POINTER to METHOD_TYPE we
6060 If FORCE is nonzero, then force this conversion, even if
6061 we would rather not do it. Usually set when using an explicit
6062 cast. A C-style cast is being processed iff C_CAST_P is true.
6064 Return error_mark_node, if something goes wrong. */
6067 build_ptrmemfunc (tree type, tree pfn, int force, bool c_cast_p)
6073 if (error_operand_p (pfn))
6074 return error_mark_node;
6076 pfn_type = TREE_TYPE (pfn);
6077 to_type = build_ptrmemfunc_type (type);
6079 /* Handle multiple conversions of pointer to member functions. */
6080 if (TYPE_PTRMEMFUNC_P (pfn_type))
6082 tree delta = NULL_TREE;
6083 tree npfn = NULL_TREE;
6087 && !can_convert_arg (to_type, TREE_TYPE (pfn), pfn, LOOKUP_NORMAL))
6088 error ("invalid conversion to type %qT from type %qT",
6091 n = get_delta_difference (TYPE_PTRMEMFUNC_OBJECT_TYPE (pfn_type),
6092 TYPE_PTRMEMFUNC_OBJECT_TYPE (to_type),
6096 /* We don't have to do any conversion to convert a
6097 pointer-to-member to its own type. But, we don't want to
6098 just return a PTRMEM_CST if there's an explicit cast; that
6099 cast should make the expression an invalid template argument. */
6100 if (TREE_CODE (pfn) != PTRMEM_CST)
6102 if (same_type_p (to_type, pfn_type))
6104 else if (integer_zerop (n))
6105 return build_reinterpret_cast (to_type, pfn);
6108 if (TREE_SIDE_EFFECTS (pfn))
6109 pfn = save_expr (pfn);
6111 /* Obtain the function pointer and the current DELTA. */
6112 if (TREE_CODE (pfn) == PTRMEM_CST)
6113 expand_ptrmemfunc_cst (pfn, &delta, &npfn);
6116 npfn = build_ptrmemfunc_access_expr (pfn, pfn_identifier);
6117 delta = build_ptrmemfunc_access_expr (pfn, delta_identifier);
6120 /* Just adjust the DELTA field. */
6121 gcc_assert (same_type_ignoring_top_level_qualifiers_p
6122 (TREE_TYPE (delta), ptrdiff_type_node));
6123 if (TARGET_PTRMEMFUNC_VBIT_LOCATION == ptrmemfunc_vbit_in_delta)
6124 n = cp_build_binary_op (LSHIFT_EXPR, n, integer_one_node);
6125 delta = cp_build_binary_op (PLUS_EXPR, delta, n);
6126 return build_ptrmemfunc1 (to_type, delta, npfn);
6129 /* Handle null pointer to member function conversions. */
6130 if (integer_zerop (pfn))
6132 pfn = build_c_cast (type, integer_zero_node);
6133 return build_ptrmemfunc1 (to_type,
6138 if (type_unknown_p (pfn))
6139 return instantiate_type (type, pfn, tf_warning_or_error);
6141 fn = TREE_OPERAND (pfn, 0);
6142 gcc_assert (TREE_CODE (fn) == FUNCTION_DECL
6143 /* In a template, we will have preserved the
6145 || (processing_template_decl && TREE_CODE (fn) == OFFSET_REF));
6146 return make_ptrmem_cst (to_type, fn);
6149 /* Return the DELTA, IDX, PFN, and DELTA2 values for the PTRMEM_CST
6152 ??? There is no consistency as to the types returned for the above
6153 values. Some code acts as if it were a sizetype and some as if it were
6154 integer_type_node. */
6157 expand_ptrmemfunc_cst (tree cst, tree *delta, tree *pfn)
6159 tree type = TREE_TYPE (cst);
6160 tree fn = PTRMEM_CST_MEMBER (cst);
6161 tree ptr_class, fn_class;
6163 gcc_assert (TREE_CODE (fn) == FUNCTION_DECL);
6165 /* The class that the function belongs to. */
6166 fn_class = DECL_CONTEXT (fn);
6168 /* The class that we're creating a pointer to member of. */
6169 ptr_class = TYPE_PTRMEMFUNC_OBJECT_TYPE (type);
6171 /* First, calculate the adjustment to the function's class. */
6172 *delta = get_delta_difference (fn_class, ptr_class, /*force=*/0,
6175 if (!DECL_VIRTUAL_P (fn))
6176 *pfn = convert (TYPE_PTRMEMFUNC_FN_TYPE (type), build_addr_func (fn));
6179 /* If we're dealing with a virtual function, we have to adjust 'this'
6180 again, to point to the base which provides the vtable entry for
6181 fn; the call will do the opposite adjustment. */
6182 tree orig_class = DECL_CONTEXT (fn);
6183 tree binfo = binfo_or_else (orig_class, fn_class);
6184 *delta = build2 (PLUS_EXPR, TREE_TYPE (*delta),
6185 *delta, BINFO_OFFSET (binfo));
6186 *delta = fold_if_not_in_template (*delta);
6188 /* We set PFN to the vtable offset at which the function can be
6189 found, plus one (unless ptrmemfunc_vbit_in_delta, in which
6190 case delta is shifted left, and then incremented). */
6191 *pfn = DECL_VINDEX (fn);
6192 *pfn = build2 (MULT_EXPR, integer_type_node, *pfn,
6193 TYPE_SIZE_UNIT (vtable_entry_type));
6194 *pfn = fold_if_not_in_template (*pfn);
6196 switch (TARGET_PTRMEMFUNC_VBIT_LOCATION)
6198 case ptrmemfunc_vbit_in_pfn:
6199 *pfn = build2 (PLUS_EXPR, integer_type_node, *pfn,
6201 *pfn = fold_if_not_in_template (*pfn);
6204 case ptrmemfunc_vbit_in_delta:
6205 *delta = build2 (LSHIFT_EXPR, TREE_TYPE (*delta),
6206 *delta, integer_one_node);
6207 *delta = fold_if_not_in_template (*delta);
6208 *delta = build2 (PLUS_EXPR, TREE_TYPE (*delta),
6209 *delta, integer_one_node);
6210 *delta = fold_if_not_in_template (*delta);
6217 *pfn = build_nop (TYPE_PTRMEMFUNC_FN_TYPE (type), *pfn);
6218 *pfn = fold_if_not_in_template (*pfn);
6222 /* Return an expression for PFN from the pointer-to-member function
6226 pfn_from_ptrmemfunc (tree t)
6228 if (TREE_CODE (t) == PTRMEM_CST)
6233 expand_ptrmemfunc_cst (t, &delta, &pfn);
6238 return build_ptrmemfunc_access_expr (t, pfn_identifier);
6241 /* Convert value RHS to type TYPE as preparation for an assignment to
6242 an lvalue of type TYPE. ERRTYPE is a string to use in error
6243 messages: "assignment", "return", etc. If FNDECL is non-NULL, we
6244 are doing the conversion in order to pass the PARMNUMth argument of
6248 convert_for_assignment (tree type, tree rhs,
6249 const char *errtype, tree fndecl, int parmnum)
6252 enum tree_code coder;
6254 /* Strip NON_LVALUE_EXPRs since we aren't using as an lvalue. */
6255 if (TREE_CODE (rhs) == NON_LVALUE_EXPR)
6256 rhs = TREE_OPERAND (rhs, 0);
6258 rhstype = TREE_TYPE (rhs);
6259 coder = TREE_CODE (rhstype);
6261 if (TREE_CODE (type) == VECTOR_TYPE && coder == VECTOR_TYPE
6262 && vector_types_convertible_p (type, rhstype, true))
6263 return convert (type, rhs);
6265 if (rhs == error_mark_node || rhstype == error_mark_node)
6266 return error_mark_node;
6267 if (TREE_CODE (rhs) == TREE_LIST && TREE_VALUE (rhs) == error_mark_node)
6268 return error_mark_node;
6270 /* The RHS of an assignment cannot have void type. */
6271 if (coder == VOID_TYPE)
6273 error ("void value not ignored as it ought to be");
6274 return error_mark_node;
6277 /* Simplify the RHS if possible. */
6278 if (TREE_CODE (rhs) == CONST_DECL)
6279 rhs = DECL_INITIAL (rhs);
6281 if (c_dialect_objc ())
6284 tree rname = fndecl;
6286 if (!strcmp (errtype, "assignment"))
6288 else if (!strcmp (errtype, "initialization"))
6292 tree selector = objc_message_selector ();
6296 if (selector && parmno > 1)
6303 if (objc_compare_types (type, rhstype, parmno, rname))
6304 return convert (type, rhs);
6309 The expression is implicitly converted (clause _conv_) to the
6310 cv-unqualified type of the left operand.
6312 We allow bad conversions here because by the time we get to this point
6313 we are committed to doing the conversion. If we end up doing a bad
6314 conversion, convert_like will complain. */
6315 if (!can_convert_arg_bad (type, rhstype, rhs))
6317 /* When -Wno-pmf-conversions is use, we just silently allow
6318 conversions from pointers-to-members to plain pointers. If
6319 the conversion doesn't work, cp_convert will complain. */
6321 && TYPE_PTR_P (type)
6322 && TYPE_PTRMEMFUNC_P (rhstype))
6323 rhs = cp_convert (strip_top_quals (type), rhs);
6326 /* If the right-hand side has unknown type, then it is an
6327 overloaded function. Call instantiate_type to get error
6329 if (rhstype == unknown_type_node)
6330 instantiate_type (type, rhs, tf_warning_or_error);
6332 error ("cannot convert %qT to %qT for argument %qP to %qD",
6333 rhstype, type, parmnum, fndecl);
6335 error ("cannot convert %qT to %qT in %s", rhstype, type, errtype);
6336 return error_mark_node;
6339 if (warn_missing_format_attribute)
6341 const enum tree_code codel = TREE_CODE (type);
6342 if ((codel == POINTER_TYPE || codel == REFERENCE_TYPE)
6344 && check_missing_format_attribute (type, rhstype))
6345 warning (OPT_Wmissing_format_attribute,
6346 "%s might be a candidate for a format attribute",
6350 /* If -Wparentheses, warn about a = b = c when a has type bool and b
6352 if (warn_parentheses
6353 && type == boolean_type_node
6354 && TREE_CODE (rhs) == MODIFY_EXPR
6355 && !TREE_NO_WARNING (rhs)
6356 && TREE_TYPE (rhs) != boolean_type_node)
6358 warning (OPT_Wparentheses,
6359 "suggest parentheses around assignment used as truth value");
6360 TREE_NO_WARNING (rhs) = 1;
6363 return perform_implicit_conversion (strip_top_quals (type), rhs);
6366 /* Convert RHS to be of type TYPE.
6367 If EXP is nonzero, it is the target of the initialization.
6368 ERRTYPE is a string to use in error messages.
6370 Two major differences between the behavior of
6371 `convert_for_assignment' and `convert_for_initialization'
6372 are that references are bashed in the former, while
6373 copied in the latter, and aggregates are assigned in
6374 the former (operator=) while initialized in the
6377 If using constructor make sure no conversion operator exists, if one does
6378 exist, an ambiguity exists.
6380 If flags doesn't include LOOKUP_COMPLAIN, don't complain about anything. */
6383 convert_for_initialization (tree exp, tree type, tree rhs, int flags,
6384 const char *errtype, tree fndecl, int parmnum)
6386 enum tree_code codel = TREE_CODE (type);
6388 enum tree_code coder;
6390 /* build_c_cast puts on a NOP_EXPR to make the result not an lvalue.
6391 Strip such NOP_EXPRs, since RHS is used in non-lvalue context. */
6392 if (TREE_CODE (rhs) == NOP_EXPR
6393 && TREE_TYPE (rhs) == TREE_TYPE (TREE_OPERAND (rhs, 0))
6394 && codel != REFERENCE_TYPE)
6395 rhs = TREE_OPERAND (rhs, 0);
6397 if (type == error_mark_node
6398 || rhs == error_mark_node
6399 || (TREE_CODE (rhs) == TREE_LIST && TREE_VALUE (rhs) == error_mark_node))
6400 return error_mark_node;
6402 if ((TREE_CODE (TREE_TYPE (rhs)) == ARRAY_TYPE
6403 && TREE_CODE (type) != ARRAY_TYPE
6404 && (TREE_CODE (type) != REFERENCE_TYPE
6405 || TREE_CODE (TREE_TYPE (type)) != ARRAY_TYPE))
6406 || (TREE_CODE (TREE_TYPE (rhs)) == FUNCTION_TYPE
6407 && (TREE_CODE (type) != REFERENCE_TYPE
6408 || TREE_CODE (TREE_TYPE (type)) != FUNCTION_TYPE))
6409 || TREE_CODE (TREE_TYPE (rhs)) == METHOD_TYPE)
6410 rhs = decay_conversion (rhs);
6412 rhstype = TREE_TYPE (rhs);
6413 coder = TREE_CODE (rhstype);
6415 if (coder == ERROR_MARK)
6416 return error_mark_node;
6418 /* We accept references to incomplete types, so we can
6419 return here before checking if RHS is of complete type. */
6421 if (codel == REFERENCE_TYPE)
6423 /* This should eventually happen in convert_arguments. */
6424 int savew = 0, savee = 0;
6427 savew = warningcount, savee = errorcount;
6428 rhs = initialize_reference (type, rhs, /*decl=*/NULL_TREE,
6432 if (warningcount > savew)
6433 warning (0, "in passing argument %P of %q+D", parmnum, fndecl);
6434 else if (errorcount > savee)
6435 error ("in passing argument %P of %q+D", parmnum, fndecl);
6441 exp = require_complete_type (exp);
6442 if (exp == error_mark_node)
6443 return error_mark_node;
6445 rhstype = non_reference (rhstype);
6447 type = complete_type (type);
6449 if (IS_AGGR_TYPE (type))
6450 return ocp_convert (type, rhs, CONV_IMPLICIT|CONV_FORCE_TEMP, flags);
6452 return convert_for_assignment (type, rhs, errtype, fndecl, parmnum);
6455 /* If RETVAL is the address of, or a reference to, a local variable or
6456 temporary give an appropriate warning. */
6459 maybe_warn_about_returning_address_of_local (tree retval)
6461 tree valtype = TREE_TYPE (DECL_RESULT (current_function_decl));
6462 tree whats_returned = retval;
6466 if (TREE_CODE (whats_returned) == COMPOUND_EXPR)
6467 whats_returned = TREE_OPERAND (whats_returned, 1);
6468 else if (TREE_CODE (whats_returned) == CONVERT_EXPR
6469 || TREE_CODE (whats_returned) == NON_LVALUE_EXPR
6470 || TREE_CODE (whats_returned) == NOP_EXPR)
6471 whats_returned = TREE_OPERAND (whats_returned, 0);
6476 if (TREE_CODE (whats_returned) != ADDR_EXPR)
6478 whats_returned = TREE_OPERAND (whats_returned, 0);
6480 if (TREE_CODE (valtype) == REFERENCE_TYPE)
6482 if (TREE_CODE (whats_returned) == AGGR_INIT_EXPR
6483 || TREE_CODE (whats_returned) == TARGET_EXPR)
6485 warning (0, "returning reference to temporary");
6488 if (TREE_CODE (whats_returned) == VAR_DECL
6489 && DECL_NAME (whats_returned)
6490 && TEMP_NAME_P (DECL_NAME (whats_returned)))
6492 warning (0, "reference to non-lvalue returned");
6497 while (TREE_CODE (whats_returned) == COMPONENT_REF
6498 || TREE_CODE (whats_returned) == ARRAY_REF)
6499 whats_returned = TREE_OPERAND (whats_returned, 0);
6501 if (DECL_P (whats_returned)
6502 && DECL_NAME (whats_returned)
6503 && DECL_FUNCTION_SCOPE_P (whats_returned)
6504 && !(TREE_STATIC (whats_returned)
6505 || TREE_PUBLIC (whats_returned)))
6507 if (TREE_CODE (valtype) == REFERENCE_TYPE)
6508 warning (0, "reference to local variable %q+D returned",
6511 warning (0, "address of local variable %q+D returned",
6517 /* Check that returning RETVAL from the current function is valid.
6518 Return an expression explicitly showing all conversions required to
6519 change RETVAL into the function return type, and to assign it to
6520 the DECL_RESULT for the function. Set *NO_WARNING to true if
6521 code reaches end of non-void function warning shouldn't be issued
6522 on this RETURN_EXPR. */
6525 check_return_expr (tree retval, bool *no_warning)
6528 /* The type actually returned by the function, after any
6531 int fn_returns_value_p;
6533 *no_warning = false;
6535 /* A `volatile' function is one that isn't supposed to return, ever.
6536 (This is a G++ extension, used to get better code for functions
6537 that call the `volatile' function.) */
6538 if (TREE_THIS_VOLATILE (current_function_decl))
6539 warning (0, "function declared %<noreturn%> has a %<return%> statement");
6541 /* Check for various simple errors. */
6542 if (DECL_DESTRUCTOR_P (current_function_decl))
6545 error ("returning a value from a destructor");
6548 else if (DECL_CONSTRUCTOR_P (current_function_decl))
6550 if (in_function_try_handler)
6551 /* If a return statement appears in a handler of the
6552 function-try-block of a constructor, the program is ill-formed. */
6553 error ("cannot return from a handler of a function-try-block of a constructor");
6555 /* You can't return a value from a constructor. */
6556 error ("returning a value from a constructor");
6560 if (processing_template_decl)
6562 current_function_returns_value = 1;
6563 check_for_bare_parameter_packs (retval);
6567 /* When no explicit return-value is given in a function with a named
6568 return value, the named return value is used. */
6569 result = DECL_RESULT (current_function_decl);
6570 valtype = TREE_TYPE (result);
6571 gcc_assert (valtype != NULL_TREE);
6572 fn_returns_value_p = !VOID_TYPE_P (valtype);
6573 if (!retval && DECL_NAME (result) && fn_returns_value_p)
6576 /* Check for a return statement with no return value in a function
6577 that's supposed to return a value. */
6578 if (!retval && fn_returns_value_p)
6580 pedwarn ("return-statement with no value, in function returning %qT",
6582 /* Clear this, so finish_function won't say that we reach the
6583 end of a non-void function (which we don't, we gave a
6585 current_function_returns_null = 0;
6586 /* And signal caller that TREE_NO_WARNING should be set on the
6587 RETURN_EXPR to avoid control reaches end of non-void function
6588 warnings in tree-cfg.c. */
6591 /* Check for a return statement with a value in a function that
6592 isn't supposed to return a value. */
6593 else if (retval && !fn_returns_value_p)
6595 if (VOID_TYPE_P (TREE_TYPE (retval)))
6596 /* You can return a `void' value from a function of `void'
6597 type. In that case, we have to evaluate the expression for
6598 its side-effects. */
6599 finish_expr_stmt (retval);
6601 pedwarn ("return-statement with a value, in function "
6602 "returning 'void'");
6604 current_function_returns_null = 1;
6606 /* There's really no value to return, after all. */
6610 /* Remember that this function can sometimes return without a
6612 current_function_returns_null = 1;
6614 /* Remember that this function did return a value. */
6615 current_function_returns_value = 1;
6617 /* Check for erroneous operands -- but after giving ourselves a
6618 chance to provide an error about returning a value from a void
6620 if (error_operand_p (retval))
6622 current_function_return_value = error_mark_node;
6623 return error_mark_node;
6626 /* Only operator new(...) throw(), can return NULL [expr.new/13]. */
6627 if ((DECL_OVERLOADED_OPERATOR_P (current_function_decl) == NEW_EXPR
6628 || DECL_OVERLOADED_OPERATOR_P (current_function_decl) == VEC_NEW_EXPR)
6629 && !TYPE_NOTHROW_P (TREE_TYPE (current_function_decl))
6631 && null_ptr_cst_p (retval))
6632 warning (0, "%<operator new%> must not return NULL unless it is "
6633 "declared %<throw()%> (or -fcheck-new is in effect)");
6635 /* Effective C++ rule 15. See also start_function. */
6637 && DECL_NAME (current_function_decl) == ansi_assopname(NOP_EXPR))
6641 /* The function return type must be a reference to the current
6643 if (TREE_CODE (valtype) == REFERENCE_TYPE
6644 && same_type_ignoring_top_level_qualifiers_p
6645 (TREE_TYPE (valtype), TREE_TYPE (current_class_ref)))
6647 /* Returning '*this' is obviously OK. */
6648 if (retval == current_class_ref)
6650 /* If we are calling a function whose return type is the same of
6651 the current class reference, it is ok. */
6652 else if (TREE_CODE (retval) == INDIRECT_REF
6653 && TREE_CODE (TREE_OPERAND (retval, 0)) == CALL_EXPR)
6658 warning (OPT_Weffc__, "%<operator=%> should return a reference to %<*this%>");
6661 /* The fabled Named Return Value optimization, as per [class.copy]/15:
6663 [...] For a function with a class return type, if the expression
6664 in the return statement is the name of a local object, and the cv-
6665 unqualified type of the local object is the same as the function
6666 return type, an implementation is permitted to omit creating the tem-
6667 porary object to hold the function return value [...]
6669 So, if this is a value-returning function that always returns the same
6670 local variable, remember it.
6672 It might be nice to be more flexible, and choose the first suitable
6673 variable even if the function sometimes returns something else, but
6674 then we run the risk of clobbering the variable we chose if the other
6675 returned expression uses the chosen variable somehow. And people expect
6676 this restriction, anyway. (jason 2000-11-19)
6678 See finish_function and finalize_nrv for the rest of this optimization. */
6680 if (fn_returns_value_p && flag_elide_constructors)
6682 if (retval != NULL_TREE
6683 && (current_function_return_value == NULL_TREE
6684 || current_function_return_value == retval)
6685 && TREE_CODE (retval) == VAR_DECL
6686 && DECL_CONTEXT (retval) == current_function_decl
6687 && ! TREE_STATIC (retval)
6688 && (DECL_ALIGN (retval)
6689 >= DECL_ALIGN (DECL_RESULT (current_function_decl)))
6690 && same_type_p ((TYPE_MAIN_VARIANT
6691 (TREE_TYPE (retval))),
6693 (TREE_TYPE (TREE_TYPE (current_function_decl))))))
6694 current_function_return_value = retval;
6696 current_function_return_value = error_mark_node;
6699 /* We don't need to do any conversions when there's nothing being
6704 /* Do any required conversions. */
6705 if (retval == result || DECL_CONSTRUCTOR_P (current_function_decl))
6706 /* No conversions are required. */
6710 /* The type the function is declared to return. */
6711 tree functype = TREE_TYPE (TREE_TYPE (current_function_decl));
6713 /* The functype's return type will have been set to void, if it
6714 was an incomplete type. Just treat this as 'return;' */
6715 if (VOID_TYPE_P (functype))
6716 return error_mark_node;
6718 /* First convert the value to the function's return type, then
6719 to the type of return value's location to handle the
6720 case that functype is smaller than the valtype. */
6721 retval = convert_for_initialization
6722 (NULL_TREE, functype, retval, LOOKUP_NORMAL|LOOKUP_ONLYCONVERTING,
6723 "return", NULL_TREE, 0);
6724 retval = convert (valtype, retval);
6726 /* If the conversion failed, treat this just like `return;'. */
6727 if (retval == error_mark_node)
6729 /* We can't initialize a register from a AGGR_INIT_EXPR. */
6730 else if (! current_function_returns_struct
6731 && TREE_CODE (retval) == TARGET_EXPR
6732 && TREE_CODE (TREE_OPERAND (retval, 1)) == AGGR_INIT_EXPR)
6733 retval = build2 (COMPOUND_EXPR, TREE_TYPE (retval), retval,
6734 TREE_OPERAND (retval, 0));
6736 maybe_warn_about_returning_address_of_local (retval);
6739 /* Actually copy the value returned into the appropriate location. */
6740 if (retval && retval != result)
6741 retval = build2 (INIT_EXPR, TREE_TYPE (result), result, retval);
6747 /* Returns nonzero if the pointer-type FROM can be converted to the
6748 pointer-type TO via a qualification conversion. If CONSTP is -1,
6749 then we return nonzero if the pointers are similar, and the
6750 cv-qualification signature of FROM is a proper subset of that of TO.
6752 If CONSTP is positive, then all outer pointers have been
6756 comp_ptr_ttypes_real (tree to, tree from, int constp)
6758 bool to_more_cv_qualified = false;
6760 for (; ; to = TREE_TYPE (to), from = TREE_TYPE (from))
6762 if (TREE_CODE (to) != TREE_CODE (from))
6765 if (TREE_CODE (from) == OFFSET_TYPE
6766 && !same_type_p (TYPE_OFFSET_BASETYPE (from),
6767 TYPE_OFFSET_BASETYPE (to)))
6770 /* Const and volatile mean something different for function types,
6771 so the usual checks are not appropriate. */
6772 if (TREE_CODE (to) != FUNCTION_TYPE && TREE_CODE (to) != METHOD_TYPE)
6774 /* In Objective-C++, some types may have been 'volatilized' by
6775 the compiler for EH; when comparing them here, the volatile
6776 qualification must be ignored. */
6777 bool objc_quals_match = objc_type_quals_match (to, from);
6779 if (!at_least_as_qualified_p (to, from) && !objc_quals_match)
6782 if (!at_least_as_qualified_p (from, to) && !objc_quals_match)
6786 to_more_cv_qualified = true;
6790 constp &= TYPE_READONLY (to);
6793 if (TREE_CODE (to) != POINTER_TYPE && !TYPE_PTRMEM_P (to))
6794 return ((constp >= 0 || to_more_cv_qualified)
6795 && same_type_ignoring_top_level_qualifiers_p (to, from));
6799 /* When comparing, say, char ** to char const **, this function takes
6800 the 'char *' and 'char const *'. Do not pass non-pointer/reference
6801 types to this function. */
6804 comp_ptr_ttypes (tree to, tree from)
6806 return comp_ptr_ttypes_real (to, from, 1);
6809 /* Returns 1 if to and from are (possibly multi-level) pointers to the same
6810 type or inheritance-related types, regardless of cv-quals. */
6813 ptr_reasonably_similar (tree to, tree from)
6815 for (; ; to = TREE_TYPE (to), from = TREE_TYPE (from))
6817 /* Any target type is similar enough to void. */
6818 if (TREE_CODE (to) == VOID_TYPE
6819 || TREE_CODE (from) == VOID_TYPE)
6822 if (TREE_CODE (to) != TREE_CODE (from))
6825 if (TREE_CODE (from) == OFFSET_TYPE
6826 && comptypes (TYPE_OFFSET_BASETYPE (to),
6827 TYPE_OFFSET_BASETYPE (from),
6828 COMPARE_BASE | COMPARE_DERIVED))
6831 if (TREE_CODE (to) == VECTOR_TYPE
6832 && vector_types_convertible_p (to, from, false))
6835 if (TREE_CODE (to) == INTEGER_TYPE
6836 && TYPE_PRECISION (to) == TYPE_PRECISION (from))
6839 if (TREE_CODE (to) == FUNCTION_TYPE)
6842 if (TREE_CODE (to) != POINTER_TYPE)
6844 (TYPE_MAIN_VARIANT (to), TYPE_MAIN_VARIANT (from),
6845 COMPARE_BASE | COMPARE_DERIVED);
6849 /* Return true if TO and FROM (both of which are POINTER_TYPEs or
6850 pointer-to-member types) are the same, ignoring cv-qualification at
6854 comp_ptr_ttypes_const (tree to, tree from)
6856 for (; ; to = TREE_TYPE (to), from = TREE_TYPE (from))
6858 if (TREE_CODE (to) != TREE_CODE (from))
6861 if (TREE_CODE (from) == OFFSET_TYPE
6862 && same_type_p (TYPE_OFFSET_BASETYPE (from),
6863 TYPE_OFFSET_BASETYPE (to)))
6866 if (TREE_CODE (to) != POINTER_TYPE)
6867 return same_type_ignoring_top_level_qualifiers_p (to, from);
6871 /* Returns the type qualifiers for this type, including the qualifiers on the
6872 elements for an array type. */
6875 cp_type_quals (tree type)
6877 type = strip_array_types (type);
6878 if (type == error_mark_node)
6879 return TYPE_UNQUALIFIED;
6880 return TYPE_QUALS (type);
6883 /* Returns nonzero if the TYPE is const from a C++ perspective: look inside
6887 cp_type_readonly (tree type)
6889 type = strip_array_types (type);
6890 return TYPE_READONLY (type);
6893 /* Returns nonzero if the TYPE contains a mutable member. */
6896 cp_has_mutable_p (tree type)
6898 type = strip_array_types (type);
6900 return CLASS_TYPE_P (type) && CLASSTYPE_HAS_MUTABLE (type);
6903 /* Apply the TYPE_QUALS to the new DECL. */
6905 cp_apply_type_quals_to_decl (int type_quals, tree decl)
6907 tree type = TREE_TYPE (decl);
6909 if (type == error_mark_node)
6912 if (TREE_CODE (type) == FUNCTION_TYPE
6913 && type_quals != TYPE_UNQUALIFIED)
6915 /* This was an error in C++98 (cv-qualifiers cannot be added to
6916 a function type), but DR 295 makes the code well-formed by
6917 dropping the extra qualifiers. */
6920 tree bad_type = build_qualified_type (type, type_quals);
6921 pedwarn ("ignoring %qV qualifiers added to function type %qT",
6925 TREE_TYPE (decl) = TYPE_MAIN_VARIANT (type);
6929 /* Avoid setting TREE_READONLY incorrectly. */
6930 if (/* If the object has a constructor, the constructor may modify
6932 TYPE_NEEDS_CONSTRUCTING (type)
6933 /* If the type isn't complete, we don't know yet if it will need
6935 || !COMPLETE_TYPE_P (type)
6936 /* If the type has a mutable component, that component might be
6938 || TYPE_HAS_MUTABLE_P (type))
6939 type_quals &= ~TYPE_QUAL_CONST;
6941 c_apply_type_quals_to_decl (type_quals, decl);
6944 /* Subroutine of casts_away_constness. Make T1 and T2 point at
6945 exemplar types such that casting T1 to T2 is casting away constness
6946 if and only if there is no implicit conversion from T1 to T2. */
6949 casts_away_constness_r (tree *t1, tree *t2)
6954 /* [expr.const.cast]
6956 For multi-level pointer to members and multi-level mixed pointers
6957 and pointers to members (conv.qual), the "member" aspect of a
6958 pointer to member level is ignored when determining if a const
6959 cv-qualifier has been cast away. */
6960 /* [expr.const.cast]
6962 For two pointer types:
6964 X1 is T1cv1,1 * ... cv1,N * where T1 is not a pointer type
6965 X2 is T2cv2,1 * ... cv2,M * where T2 is not a pointer type
6968 casting from X1 to X2 casts away constness if, for a non-pointer
6969 type T there does not exist an implicit conversion (clause
6972 Tcv1,(N-K+1) * cv1,(N-K+2) * ... cv1,N *
6976 Tcv2,(M-K+1) * cv2,(M-K+2) * ... cv2,M *. */
6977 if ((!TYPE_PTR_P (*t1) && !TYPE_PTRMEM_P (*t1))
6978 || (!TYPE_PTR_P (*t2) && !TYPE_PTRMEM_P (*t2)))
6980 *t1 = cp_build_qualified_type (void_type_node,
6981 cp_type_quals (*t1));
6982 *t2 = cp_build_qualified_type (void_type_node,
6983 cp_type_quals (*t2));
6987 quals1 = cp_type_quals (*t1);
6988 quals2 = cp_type_quals (*t2);
6990 if (TYPE_PTRMEM_P (*t1))
6991 *t1 = TYPE_PTRMEM_POINTED_TO_TYPE (*t1);
6993 *t1 = TREE_TYPE (*t1);
6994 if (TYPE_PTRMEM_P (*t2))
6995 *t2 = TYPE_PTRMEM_POINTED_TO_TYPE (*t2);
6997 *t2 = TREE_TYPE (*t2);
6999 casts_away_constness_r (t1, t2);
7000 *t1 = build_pointer_type (*t1);
7001 *t2 = build_pointer_type (*t2);
7002 *t1 = cp_build_qualified_type (*t1, quals1);
7003 *t2 = cp_build_qualified_type (*t2, quals2);
7006 /* Returns nonzero if casting from TYPE1 to TYPE2 casts away
7010 casts_away_constness (tree t1, tree t2)
7012 if (TREE_CODE (t2) == REFERENCE_TYPE)
7014 /* [expr.const.cast]
7016 Casting from an lvalue of type T1 to an lvalue of type T2
7017 using a reference cast casts away constness if a cast from an
7018 rvalue of type "pointer to T1" to the type "pointer to T2"
7019 casts away constness. */
7020 t1 = (TREE_CODE (t1) == REFERENCE_TYPE ? TREE_TYPE (t1) : t1);
7021 return casts_away_constness (build_pointer_type (t1),
7022 build_pointer_type (TREE_TYPE (t2)));
7025 if (TYPE_PTRMEM_P (t1) && TYPE_PTRMEM_P (t2))
7026 /* [expr.const.cast]
7028 Casting from an rvalue of type "pointer to data member of X
7029 of type T1" to the type "pointer to data member of Y of type
7030 T2" casts away constness if a cast from an rvalue of type
7031 "pointer to T1" to the type "pointer to T2" casts away
7033 return casts_away_constness
7034 (build_pointer_type (TYPE_PTRMEM_POINTED_TO_TYPE (t1)),
7035 build_pointer_type (TYPE_PTRMEM_POINTED_TO_TYPE (t2)));
7037 /* Casting away constness is only something that makes sense for
7038 pointer or reference types. */
7039 if (TREE_CODE (t1) != POINTER_TYPE
7040 || TREE_CODE (t2) != POINTER_TYPE)
7043 /* Top-level qualifiers don't matter. */
7044 t1 = TYPE_MAIN_VARIANT (t1);
7045 t2 = TYPE_MAIN_VARIANT (t2);
7046 casts_away_constness_r (&t1, &t2);
7047 if (!can_convert (t2, t1))
7053 /* If T is a REFERENCE_TYPE return the type to which T refers.
7054 Otherwise, return T itself. */
7057 non_reference (tree t)
7059 if (TREE_CODE (t) == REFERENCE_TYPE)
7065 /* Return nonzero if REF is an lvalue valid for this language;
7066 otherwise, print an error message and return zero. USE says
7067 how the lvalue is being used and so selects the error message. */
7070 lvalue_or_else (tree ref, enum lvalue_use use)
7072 int win = lvalue_p (ref);