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 3, or (at your option)
14 GCC is distributed in the hope that it will be useful,
15 but WITHOUT ANY WARRANTY; without even the implied warranty of
16 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
17 GNU General Public License for more details.
19 You should have received a copy of the GNU General Public License
20 along with GCC; see the file COPYING3. If not see
21 <http://www.gnu.org/licenses/>. */
24 /* This file is part of the C++ front end.
25 It contains routines to build C++ expressions given their operands,
26 including computing the types of the result, C and C++ specific error
27 checks, and some optimization. */
31 #include "coretypes.h"
41 #include "diagnostic.h"
48 static tree pfn_from_ptrmemfunc (tree);
49 static tree convert_for_assignment (tree, tree, const char *, tree, int);
50 static tree cp_pointer_int_sum (enum tree_code, tree, tree);
51 static tree rationalize_conditional_expr (enum tree_code, tree);
52 static int comp_ptr_ttypes_real (tree, tree, int);
53 static bool comp_except_types (tree, tree, bool);
54 static bool comp_array_types (tree, tree, bool);
55 static tree pointer_diff (tree, tree, tree);
56 static tree get_delta_difference (tree, tree, bool, bool);
57 static void casts_away_constness_r (tree *, tree *);
58 static bool casts_away_constness (tree, tree);
59 static void maybe_warn_about_returning_address_of_local (tree);
60 static tree lookup_destructor (tree, tree, tree);
61 static int convert_arguments (int, tree *, tree, tree, tree, int);
63 /* Do `exp = require_complete_type (exp);' to make sure exp
64 does not have an incomplete type. (That includes void types.)
65 Returns the error_mark_node if the VALUE does not have
66 complete type when this function returns. */
69 require_complete_type (tree value)
73 if (processing_template_decl || value == error_mark_node)
76 if (TREE_CODE (value) == OVERLOAD)
77 type = unknown_type_node;
79 type = TREE_TYPE (value);
81 if (type == error_mark_node)
82 return error_mark_node;
84 /* First, detect a valid value with a complete type. */
85 if (COMPLETE_TYPE_P (type))
88 if (complete_type_or_else (type, value))
91 return error_mark_node;
94 /* Try to complete TYPE, if it is incomplete. For example, if TYPE is
95 a template instantiation, do the instantiation. Returns TYPE,
96 whether or not it could be completed, unless something goes
97 horribly wrong, in which case the error_mark_node is returned. */
100 complete_type (tree type)
102 if (type == NULL_TREE)
103 /* Rather than crash, we return something sure to cause an error
105 return error_mark_node;
107 if (type == error_mark_node || COMPLETE_TYPE_P (type))
109 else if (TREE_CODE (type) == ARRAY_TYPE && TYPE_DOMAIN (type))
111 tree t = complete_type (TREE_TYPE (type));
112 unsigned int needs_constructing, has_nontrivial_dtor;
113 if (COMPLETE_TYPE_P (t) && !dependent_type_p (type))
116 = TYPE_NEEDS_CONSTRUCTING (TYPE_MAIN_VARIANT (t));
118 = TYPE_HAS_NONTRIVIAL_DESTRUCTOR (TYPE_MAIN_VARIANT (t));
119 for (t = TYPE_MAIN_VARIANT (type); t; t = TYPE_NEXT_VARIANT (t))
121 TYPE_NEEDS_CONSTRUCTING (t) = needs_constructing;
122 TYPE_HAS_NONTRIVIAL_DESTRUCTOR (t) = has_nontrivial_dtor;
125 else if (CLASS_TYPE_P (type) && CLASSTYPE_TEMPLATE_INSTANTIATION (type))
126 instantiate_class_template (TYPE_MAIN_VARIANT (type));
131 /* Like complete_type, but issue an error if the TYPE cannot be completed.
132 VALUE is used for informative diagnostics.
133 Returns NULL_TREE if the type cannot be made complete. */
136 complete_type_or_else (tree type, tree value)
138 type = complete_type (type);
139 if (type == error_mark_node)
140 /* We already issued an error. */
142 else if (!COMPLETE_TYPE_P (type))
144 cxx_incomplete_type_diagnostic (value, type, 0);
151 /* Return truthvalue of whether type of EXP is instantiated. */
154 type_unknown_p (tree exp)
156 return (TREE_CODE (exp) == TREE_LIST
157 || TREE_TYPE (exp) == unknown_type_node);
161 /* Return the common type of two parameter lists.
162 We assume that comptypes has already been done and returned 1;
163 if that isn't so, this may crash.
165 As an optimization, free the space we allocate if the parameter
166 lists are already common. */
169 commonparms (tree p1, tree p2)
171 tree oldargs = p1, newargs, n;
175 len = list_length (p1);
176 newargs = tree_last (p1);
178 if (newargs == void_list_node)
187 newargs = tree_cons (NULL_TREE, NULL_TREE, newargs);
192 p1 = TREE_CHAIN (p1), p2 = TREE_CHAIN (p2), n = TREE_CHAIN (n), i++)
194 if (TREE_PURPOSE (p1) && !TREE_PURPOSE (p2))
196 TREE_PURPOSE (n) = TREE_PURPOSE (p1);
199 else if (! TREE_PURPOSE (p1))
201 if (TREE_PURPOSE (p2))
203 TREE_PURPOSE (n) = TREE_PURPOSE (p2);
209 if (1 != simple_cst_equal (TREE_PURPOSE (p1), TREE_PURPOSE (p2)))
211 TREE_PURPOSE (n) = TREE_PURPOSE (p2);
213 if (TREE_VALUE (p1) != TREE_VALUE (p2))
216 TREE_VALUE (n) = merge_types (TREE_VALUE (p1), TREE_VALUE (p2));
219 TREE_VALUE (n) = TREE_VALUE (p1);
227 /* Given a type, perhaps copied for a typedef,
228 find the "original" version of it. */
230 original_type (tree t)
232 int quals = cp_type_quals (t);
233 while (t != error_mark_node
234 && TYPE_NAME (t) != NULL_TREE)
236 tree x = TYPE_NAME (t);
237 if (TREE_CODE (x) != TYPE_DECL)
239 x = DECL_ORIGINAL_TYPE (x);
244 return cp_build_qualified_type (t, quals);
247 /* T1 and T2 are arithmetic or enumeration types. Return the type
248 that will result from the "usual arithmetic conversions" on T1 and
249 T2 as described in [expr]. */
252 type_after_usual_arithmetic_conversions (tree t1, tree t2)
254 enum tree_code code1 = TREE_CODE (t1);
255 enum tree_code code2 = TREE_CODE (t2);
258 /* FIXME: Attributes. */
259 gcc_assert (ARITHMETIC_TYPE_P (t1)
260 || TREE_CODE (t1) == VECTOR_TYPE
261 || TREE_CODE (t1) == ENUMERAL_TYPE);
262 gcc_assert (ARITHMETIC_TYPE_P (t2)
263 || TREE_CODE (t2) == VECTOR_TYPE
264 || TREE_CODE (t2) == ENUMERAL_TYPE);
266 /* In what follows, we slightly generalize the rules given in [expr] so
267 as to deal with `long long' and `complex'. First, merge the
269 attributes = (*targetm.merge_type_attributes) (t1, t2);
271 /* If one type is complex, form the common type of the non-complex
272 components, then make that complex. Use T1 or T2 if it is the
274 if (code1 == COMPLEX_TYPE || code2 == COMPLEX_TYPE)
276 tree subtype1 = code1 == COMPLEX_TYPE ? TREE_TYPE (t1) : t1;
277 tree subtype2 = code2 == COMPLEX_TYPE ? TREE_TYPE (t2) : t2;
279 = type_after_usual_arithmetic_conversions (subtype1, subtype2);
281 if (code1 == COMPLEX_TYPE && TREE_TYPE (t1) == subtype)
282 return build_type_attribute_variant (t1, attributes);
283 else if (code2 == COMPLEX_TYPE && TREE_TYPE (t2) == subtype)
284 return build_type_attribute_variant (t2, attributes);
286 return build_type_attribute_variant (build_complex_type (subtype),
290 if (code1 == VECTOR_TYPE)
292 /* When we get here we should have two vectors of the same size.
293 Just prefer the unsigned one if present. */
294 if (TYPE_UNSIGNED (t1))
295 return build_type_attribute_variant (t1, attributes);
297 return build_type_attribute_variant (t2, attributes);
300 /* If only one is real, use it as the result. */
301 if (code1 == REAL_TYPE && code2 != REAL_TYPE)
302 return build_type_attribute_variant (t1, attributes);
303 if (code2 == REAL_TYPE && code1 != REAL_TYPE)
304 return build_type_attribute_variant (t2, attributes);
306 /* Perform the integral promotions. */
307 if (code1 != REAL_TYPE)
309 t1 = type_promotes_to (t1);
310 t2 = type_promotes_to (t2);
313 /* Both real or both integers; use the one with greater precision. */
314 if (TYPE_PRECISION (t1) > TYPE_PRECISION (t2))
315 return build_type_attribute_variant (t1, attributes);
316 else if (TYPE_PRECISION (t2) > TYPE_PRECISION (t1))
317 return build_type_attribute_variant (t2, attributes);
319 /* The types are the same; no need to do anything fancy. */
320 if (TYPE_MAIN_VARIANT (t1) == TYPE_MAIN_VARIANT (t2))
321 return build_type_attribute_variant (t1, attributes);
323 if (code1 != REAL_TYPE)
325 /* If one is unsigned long long, then convert the other to unsigned
327 if (same_type_p (TYPE_MAIN_VARIANT (t1), long_long_unsigned_type_node)
328 || same_type_p (TYPE_MAIN_VARIANT (t2), long_long_unsigned_type_node))
329 return build_type_attribute_variant (long_long_unsigned_type_node,
331 /* If one is a long long, and the other is an unsigned long, and
332 long long can represent all the values of an unsigned long, then
333 convert to a long long. Otherwise, convert to an unsigned long
334 long. Otherwise, if either operand is long long, convert the
337 Since we're here, we know the TYPE_PRECISION is the same;
338 therefore converting to long long cannot represent all the values
339 of an unsigned long, so we choose unsigned long long in that
341 if (same_type_p (TYPE_MAIN_VARIANT (t1), long_long_integer_type_node)
342 || same_type_p (TYPE_MAIN_VARIANT (t2), long_long_integer_type_node))
344 tree t = ((TYPE_UNSIGNED (t1) || TYPE_UNSIGNED (t2))
345 ? long_long_unsigned_type_node
346 : long_long_integer_type_node);
347 return build_type_attribute_variant (t, attributes);
350 /* Go through the same procedure, but for longs. */
351 if (same_type_p (TYPE_MAIN_VARIANT (t1), long_unsigned_type_node)
352 || same_type_p (TYPE_MAIN_VARIANT (t2), long_unsigned_type_node))
353 return build_type_attribute_variant (long_unsigned_type_node,
355 if (same_type_p (TYPE_MAIN_VARIANT (t1), long_integer_type_node)
356 || same_type_p (TYPE_MAIN_VARIANT (t2), long_integer_type_node))
358 tree t = ((TYPE_UNSIGNED (t1) || TYPE_UNSIGNED (t2))
359 ? long_unsigned_type_node : long_integer_type_node);
360 return build_type_attribute_variant (t, attributes);
362 /* Otherwise prefer the unsigned one. */
363 if (TYPE_UNSIGNED (t1))
364 return build_type_attribute_variant (t1, attributes);
366 return build_type_attribute_variant (t2, attributes);
370 if (same_type_p (TYPE_MAIN_VARIANT (t1), long_double_type_node)
371 || same_type_p (TYPE_MAIN_VARIANT (t2), long_double_type_node))
372 return build_type_attribute_variant (long_double_type_node,
374 if (same_type_p (TYPE_MAIN_VARIANT (t1), double_type_node)
375 || same_type_p (TYPE_MAIN_VARIANT (t2), double_type_node))
376 return build_type_attribute_variant (double_type_node,
378 if (same_type_p (TYPE_MAIN_VARIANT (t1), float_type_node)
379 || same_type_p (TYPE_MAIN_VARIANT (t2), float_type_node))
380 return build_type_attribute_variant (float_type_node,
383 /* Two floating-point types whose TYPE_MAIN_VARIANTs are none of
384 the standard C++ floating-point types. Logic earlier in this
385 function has already eliminated the possibility that
386 TYPE_PRECISION (t2) != TYPE_PRECISION (t1), so there's no
387 compelling reason to choose one or the other. */
388 return build_type_attribute_variant (t1, attributes);
392 /* Subroutine of composite_pointer_type to implement the recursive
393 case. See that function for documentation fo the parameters. */
396 composite_pointer_type_r (tree t1, tree t2, const char* location)
403 /* Determine the types pointed to by T1 and T2. */
404 if (TREE_CODE (t1) == POINTER_TYPE)
406 pointee1 = TREE_TYPE (t1);
407 pointee2 = TREE_TYPE (t2);
411 pointee1 = TYPE_PTRMEM_POINTED_TO_TYPE (t1);
412 pointee2 = TYPE_PTRMEM_POINTED_TO_TYPE (t2);
417 Otherwise, the composite pointer type is a pointer type
418 similar (_conv.qual_) to the type of one of the operands,
419 with a cv-qualification signature (_conv.qual_) that is the
420 union of the cv-qualification signatures of the operand
422 if (same_type_ignoring_top_level_qualifiers_p (pointee1, pointee2))
423 result_type = pointee1;
424 else if ((TREE_CODE (pointee1) == POINTER_TYPE
425 && TREE_CODE (pointee2) == POINTER_TYPE)
426 || (TYPE_PTR_TO_MEMBER_P (pointee1)
427 && TYPE_PTR_TO_MEMBER_P (pointee2)))
428 result_type = composite_pointer_type_r (pointee1, pointee2, location);
431 pedwarn ("%s between distinct pointer types %qT and %qT "
434 result_type = void_type_node;
436 result_type = cp_build_qualified_type (result_type,
437 (cp_type_quals (pointee1)
438 | cp_type_quals (pointee2)));
439 /* If the original types were pointers to members, so is the
441 if (TYPE_PTR_TO_MEMBER_P (t1))
443 if (!same_type_p (TYPE_PTRMEM_CLASS_TYPE (t1),
444 TYPE_PTRMEM_CLASS_TYPE (t2)))
445 pedwarn ("%s between distinct pointer types %qT and %qT "
448 result_type = build_ptrmem_type (TYPE_PTRMEM_CLASS_TYPE (t1),
452 result_type = build_pointer_type (result_type);
454 /* Merge the attributes. */
455 attributes = (*targetm.merge_type_attributes) (t1, t2);
456 return build_type_attribute_variant (result_type, attributes);
459 /* Return the composite pointer type (see [expr.rel]) for T1 and T2.
460 ARG1 and ARG2 are the values with those types. The LOCATION is a
461 string describing the current location, in case an error occurs.
463 This routine also implements the computation of a common type for
464 pointers-to-members as per [expr.eq]. */
467 composite_pointer_type (tree t1, tree t2, tree arg1, tree arg2,
468 const char* location)
475 If one operand is a null pointer constant, the composite pointer
476 type is the type of the other operand. */
477 if (null_ptr_cst_p (arg1))
479 if (null_ptr_cst_p (arg2))
486 If one of the operands has type "pointer to cv1 void*", then
487 the other has type "pointer to cv2T", and the composite pointer
488 type is "pointer to cv12 void", where cv12 is the union of cv1
491 If either type is a pointer to void, make sure it is T1. */
492 if (TREE_CODE (t2) == POINTER_TYPE && VOID_TYPE_P (TREE_TYPE (t2)))
500 /* Now, if T1 is a pointer to void, merge the qualifiers. */
501 if (TREE_CODE (t1) == POINTER_TYPE && VOID_TYPE_P (TREE_TYPE (t1)))
506 if (pedantic && TYPE_PTRFN_P (t2))
507 pedwarn ("ISO C++ forbids %s between pointer of type %<void *%> "
508 "and pointer-to-function", location);
510 = cp_build_qualified_type (void_type_node,
511 (cp_type_quals (TREE_TYPE (t1))
512 | cp_type_quals (TREE_TYPE (t2))));
513 result_type = build_pointer_type (result_type);
514 /* Merge the attributes. */
515 attributes = (*targetm.merge_type_attributes) (t1, t2);
516 return build_type_attribute_variant (result_type, attributes);
519 if (c_dialect_objc () && TREE_CODE (t1) == POINTER_TYPE
520 && TREE_CODE (t2) == POINTER_TYPE)
522 if (objc_compare_types (t1, t2, -3, NULL_TREE))
526 /* [expr.eq] permits the application of a pointer conversion to
527 bring the pointers to a common type. */
528 if (TREE_CODE (t1) == POINTER_TYPE && TREE_CODE (t2) == POINTER_TYPE
529 && CLASS_TYPE_P (TREE_TYPE (t1))
530 && CLASS_TYPE_P (TREE_TYPE (t2))
531 && !same_type_ignoring_top_level_qualifiers_p (TREE_TYPE (t1),
534 class1 = TREE_TYPE (t1);
535 class2 = TREE_TYPE (t2);
537 if (DERIVED_FROM_P (class1, class2))
538 t2 = (build_pointer_type
539 (cp_build_qualified_type (class1, TYPE_QUALS (class2))));
540 else if (DERIVED_FROM_P (class2, class1))
541 t1 = (build_pointer_type
542 (cp_build_qualified_type (class2, TYPE_QUALS (class1))));
545 error ("%s between distinct pointer types %qT and %qT "
546 "lacks a cast", location, t1, t2);
547 return error_mark_node;
550 /* [expr.eq] permits the application of a pointer-to-member
551 conversion to change the class type of one of the types. */
552 else if (TYPE_PTR_TO_MEMBER_P (t1)
553 && !same_type_p (TYPE_PTRMEM_CLASS_TYPE (t1),
554 TYPE_PTRMEM_CLASS_TYPE (t2)))
556 class1 = TYPE_PTRMEM_CLASS_TYPE (t1);
557 class2 = TYPE_PTRMEM_CLASS_TYPE (t2);
559 if (DERIVED_FROM_P (class1, class2))
560 t1 = build_ptrmem_type (class2, TYPE_PTRMEM_POINTED_TO_TYPE (t1));
561 else if (DERIVED_FROM_P (class2, class1))
562 t2 = build_ptrmem_type (class1, TYPE_PTRMEM_POINTED_TO_TYPE (t2));
565 error ("%s between distinct pointer-to-member types %qT and %qT "
566 "lacks a cast", location, t1, t2);
567 return error_mark_node;
571 return composite_pointer_type_r (t1, t2, location);
574 /* Return the merged type of two types.
575 We assume that comptypes has already been done and returned 1;
576 if that isn't so, this may crash.
578 This just combines attributes and default arguments; any other
579 differences would cause the two types to compare unalike. */
582 merge_types (tree t1, tree t2)
584 enum tree_code code1;
585 enum tree_code code2;
588 /* Save time if the two types are the same. */
591 if (original_type (t1) == original_type (t2))
594 /* If one type is nonsense, use the other. */
595 if (t1 == error_mark_node)
597 if (t2 == error_mark_node)
600 /* Merge the attributes. */
601 attributes = (*targetm.merge_type_attributes) (t1, t2);
603 if (TYPE_PTRMEMFUNC_P (t1))
604 t1 = TYPE_PTRMEMFUNC_FN_TYPE (t1);
605 if (TYPE_PTRMEMFUNC_P (t2))
606 t2 = TYPE_PTRMEMFUNC_FN_TYPE (t2);
608 code1 = TREE_CODE (t1);
609 code2 = TREE_CODE (t2);
615 /* For two pointers, do this recursively on the target type. */
617 tree target = merge_types (TREE_TYPE (t1), TREE_TYPE (t2));
618 int quals = cp_type_quals (t1);
620 if (code1 == POINTER_TYPE)
621 t1 = build_pointer_type (target);
623 t1 = build_reference_type (target);
624 t1 = build_type_attribute_variant (t1, attributes);
625 t1 = cp_build_qualified_type (t1, quals);
627 if (TREE_CODE (target) == METHOD_TYPE)
628 t1 = build_ptrmemfunc_type (t1);
637 quals = cp_type_quals (t1);
638 pointee = merge_types (TYPE_PTRMEM_POINTED_TO_TYPE (t1),
639 TYPE_PTRMEM_POINTED_TO_TYPE (t2));
640 t1 = build_ptrmem_type (TYPE_PTRMEM_CLASS_TYPE (t1),
642 t1 = cp_build_qualified_type (t1, quals);
648 tree elt = merge_types (TREE_TYPE (t1), TREE_TYPE (t2));
649 /* Save space: see if the result is identical to one of the args. */
650 if (elt == TREE_TYPE (t1) && TYPE_DOMAIN (t1))
651 return build_type_attribute_variant (t1, attributes);
652 if (elt == TREE_TYPE (t2) && TYPE_DOMAIN (t2))
653 return build_type_attribute_variant (t2, attributes);
654 /* Merge the element types, and have a size if either arg has one. */
655 t1 = build_cplus_array_type
656 (elt, TYPE_DOMAIN (TYPE_DOMAIN (t1) ? t1 : t2));
661 /* Function types: prefer the one that specified arg types.
662 If both do, merge the arg types. Also merge the return types. */
664 tree valtype = merge_types (TREE_TYPE (t1), TREE_TYPE (t2));
665 tree p1 = TYPE_ARG_TYPES (t1);
666 tree p2 = TYPE_ARG_TYPES (t2);
669 /* Save space: see if the result is identical to one of the args. */
670 if (valtype == TREE_TYPE (t1) && ! p2)
671 return cp_build_type_attribute_variant (t1, attributes);
672 if (valtype == TREE_TYPE (t2) && ! p1)
673 return cp_build_type_attribute_variant (t2, attributes);
675 /* Simple way if one arg fails to specify argument types. */
676 if (p1 == NULL_TREE || TREE_VALUE (p1) == void_type_node)
678 rval = build_function_type (valtype, p2);
679 if ((raises = TYPE_RAISES_EXCEPTIONS (t2)))
680 rval = build_exception_variant (rval, raises);
681 return cp_build_type_attribute_variant (rval, attributes);
683 raises = TYPE_RAISES_EXCEPTIONS (t1);
684 if (p2 == NULL_TREE || TREE_VALUE (p2) == void_type_node)
686 rval = build_function_type (valtype, p1);
688 rval = build_exception_variant (rval, raises);
689 return cp_build_type_attribute_variant (rval, attributes);
692 rval = build_function_type (valtype, commonparms (p1, p2));
693 t1 = build_exception_variant (rval, raises);
699 /* Get this value the long way, since TYPE_METHOD_BASETYPE
700 is just the main variant of this. */
701 tree basetype = TREE_TYPE (TREE_VALUE (TYPE_ARG_TYPES (t2)));
702 tree raises = TYPE_RAISES_EXCEPTIONS (t1);
705 /* If this was a member function type, get back to the
706 original type of type member function (i.e., without
707 the class instance variable up front. */
708 t1 = build_function_type (TREE_TYPE (t1),
709 TREE_CHAIN (TYPE_ARG_TYPES (t1)));
710 t2 = build_function_type (TREE_TYPE (t2),
711 TREE_CHAIN (TYPE_ARG_TYPES (t2)));
712 t3 = merge_types (t1, t2);
713 t3 = build_method_type_directly (basetype, TREE_TYPE (t3),
714 TYPE_ARG_TYPES (t3));
715 t1 = build_exception_variant (t3, raises);
720 /* There is no need to merge attributes into a TYPENAME_TYPE.
721 When the type is instantiated it will have whatever
722 attributes result from the instantiation. */
728 if (attribute_list_equal (TYPE_ATTRIBUTES (t1), attributes))
730 else if (attribute_list_equal (TYPE_ATTRIBUTES (t2), attributes))
733 return cp_build_type_attribute_variant (t1, attributes);
736 /* Return the common type of two types.
737 We assume that comptypes has already been done and returned 1;
738 if that isn't so, this may crash.
740 This is the type for the result of most arithmetic operations
741 if the operands have the given two types. */
744 common_type (tree t1, tree t2)
746 enum tree_code code1;
747 enum tree_code code2;
749 /* If one type is nonsense, bail. */
750 if (t1 == error_mark_node || t2 == error_mark_node)
751 return error_mark_node;
753 code1 = TREE_CODE (t1);
754 code2 = TREE_CODE (t2);
756 if ((ARITHMETIC_TYPE_P (t1) || code1 == ENUMERAL_TYPE
757 || code1 == VECTOR_TYPE)
758 && (ARITHMETIC_TYPE_P (t2) || code2 == ENUMERAL_TYPE
759 || code2 == VECTOR_TYPE))
760 return type_after_usual_arithmetic_conversions (t1, t2);
762 else if ((TYPE_PTR_P (t1) && TYPE_PTR_P (t2))
763 || (TYPE_PTRMEM_P (t1) && TYPE_PTRMEM_P (t2))
764 || (TYPE_PTRMEMFUNC_P (t1) && TYPE_PTRMEMFUNC_P (t2)))
765 return composite_pointer_type (t1, t2, error_mark_node, error_mark_node,
771 /* Compare two exception specifier types for exactness or subsetness, if
772 allowed. Returns false for mismatch, true for match (same, or
775 [except.spec] "If a class X ... objects of class X or any class publicly
776 and unambiguously derived from X. Similarly, if a pointer type Y * ...
777 exceptions of type Y * or that are pointers to any type publicly and
778 unambiguously derived from Y. Otherwise a function only allows exceptions
779 that have the same type ..."
780 This does not mention cv qualifiers and is different to what throw
781 [except.throw] and catch [except.catch] will do. They will ignore the
782 top level cv qualifiers, and allow qualifiers in the pointer to class
785 We implement the letter of the standard. */
788 comp_except_types (tree a, tree b, bool exact)
790 if (same_type_p (a, b))
794 if (cp_type_quals (a) || cp_type_quals (b))
797 if (TREE_CODE (a) == POINTER_TYPE
798 && TREE_CODE (b) == POINTER_TYPE)
802 if (cp_type_quals (a) || cp_type_quals (b))
806 if (TREE_CODE (a) != RECORD_TYPE
807 || TREE_CODE (b) != RECORD_TYPE)
810 if (PUBLICLY_UNIQUELY_DERIVED_P (a, b))
816 /* Return true if TYPE1 and TYPE2 are equivalent exception specifiers.
817 If EXACT is false, T2 can be stricter than T1 (according to 15.4/7),
818 otherwise it must be exact. Exception lists are unordered, but
819 we've already filtered out duplicates. Most lists will be in order,
820 we should try to make use of that. */
823 comp_except_specs (tree t1, tree t2, bool exact)
832 if (t1 == NULL_TREE) /* T1 is ... */
833 return t2 == NULL_TREE || !exact;
834 if (!TREE_VALUE (t1)) /* t1 is EMPTY */
835 return t2 != NULL_TREE && !TREE_VALUE (t2);
836 if (t2 == NULL_TREE) /* T2 is ... */
838 if (TREE_VALUE (t1) && !TREE_VALUE (t2)) /* T2 is EMPTY, T1 is not */
841 /* Neither set is ... or EMPTY, make sure each part of T2 is in T1.
842 Count how many we find, to determine exactness. For exact matching and
843 ordered T1, T2, this is an O(n) operation, otherwise its worst case is
845 for (base = t1; t2 != NULL_TREE; t2 = TREE_CHAIN (t2))
847 for (probe = base; probe != NULL_TREE; probe = TREE_CHAIN (probe))
849 tree a = TREE_VALUE (probe);
850 tree b = TREE_VALUE (t2);
852 if (comp_except_types (a, b, exact))
854 if (probe == base && exact)
855 base = TREE_CHAIN (probe);
860 if (probe == NULL_TREE)
863 return !exact || base == NULL_TREE || length == list_length (t1);
866 /* Compare the array types T1 and T2. ALLOW_REDECLARATION is true if
867 [] can match [size]. */
870 comp_array_types (tree t1, tree t2, bool allow_redeclaration)
879 /* The type of the array elements must be the same. */
880 if (!same_type_p (TREE_TYPE (t1), TREE_TYPE (t2)))
883 d1 = TYPE_DOMAIN (t1);
884 d2 = TYPE_DOMAIN (t2);
889 /* If one of the arrays is dimensionless, and the other has a
890 dimension, they are of different types. However, it is valid to
898 declarations for an array object can specify
899 array types that differ by the presence or absence of a major
900 array bound (_dcl.array_). */
902 return allow_redeclaration;
904 /* Check that the dimensions are the same. */
906 if (!cp_tree_equal (TYPE_MIN_VALUE (d1), TYPE_MIN_VALUE (d2)))
908 max1 = TYPE_MAX_VALUE (d1);
909 max2 = TYPE_MAX_VALUE (d2);
910 if (processing_template_decl && !abi_version_at_least (2)
911 && !value_dependent_expression_p (max1)
912 && !value_dependent_expression_p (max2))
914 /* With abi-1 we do not fold non-dependent array bounds, (and
915 consequently mangle them incorrectly). We must therefore
916 fold them here, to verify the domains have the same
922 if (!cp_tree_equal (max1, max2))
928 /* Subroutine in comptypes. */
931 structural_comptypes (tree t1, tree t2, int strict)
936 /* Suppress errors caused by previously reported errors. */
937 if (t1 == error_mark_node || t2 == error_mark_node)
940 gcc_assert (TYPE_P (t1) && TYPE_P (t2));
942 /* TYPENAME_TYPEs should be resolved if the qualifying scope is the
943 current instantiation. */
944 if (TREE_CODE (t1) == TYPENAME_TYPE)
945 t1 = resolve_typename_type (t1, /*only_current_p=*/true);
947 if (TREE_CODE (t2) == TYPENAME_TYPE)
948 t2 = resolve_typename_type (t2, /*only_current_p=*/true);
950 if (TYPE_PTRMEMFUNC_P (t1))
951 t1 = TYPE_PTRMEMFUNC_FN_TYPE (t1);
952 if (TYPE_PTRMEMFUNC_P (t2))
953 t2 = TYPE_PTRMEMFUNC_FN_TYPE (t2);
955 /* Different classes of types can't be compatible. */
956 if (TREE_CODE (t1) != TREE_CODE (t2))
959 /* Qualifiers must match. For array types, we will check when we
960 recur on the array element types. */
961 if (TREE_CODE (t1) != ARRAY_TYPE
962 && TYPE_QUALS (t1) != TYPE_QUALS (t2))
964 if (TYPE_FOR_JAVA (t1) != TYPE_FOR_JAVA (t2))
967 /* Allow for two different type nodes which have essentially the same
968 definition. Note that we already checked for equality of the type
969 qualifiers (just above). */
971 if (TREE_CODE (t1) != ARRAY_TYPE
972 && TYPE_MAIN_VARIANT (t1) == TYPE_MAIN_VARIANT (t2))
975 /* Compare the types. Break out if they could be the same. */
976 switch (TREE_CODE (t1))
978 case TEMPLATE_TEMPLATE_PARM:
979 case BOUND_TEMPLATE_TEMPLATE_PARM:
980 if (TEMPLATE_TYPE_IDX (t1) != TEMPLATE_TYPE_IDX (t2)
981 || TEMPLATE_TYPE_LEVEL (t1) != TEMPLATE_TYPE_LEVEL (t2)
982 || (TEMPLATE_TYPE_PARAMETER_PACK (t1)
983 != TEMPLATE_TYPE_PARAMETER_PACK (t2)))
985 if (!comp_template_parms
986 (DECL_TEMPLATE_PARMS (TEMPLATE_TEMPLATE_PARM_TEMPLATE_DECL (t1)),
987 DECL_TEMPLATE_PARMS (TEMPLATE_TEMPLATE_PARM_TEMPLATE_DECL (t2))))
989 if (TREE_CODE (t1) == TEMPLATE_TEMPLATE_PARM)
991 /* Don't check inheritance. */
992 strict = COMPARE_STRICT;
997 if (TYPE_TEMPLATE_INFO (t1) && TYPE_TEMPLATE_INFO (t2)
998 && (TYPE_TI_TEMPLATE (t1) == TYPE_TI_TEMPLATE (t2)
999 || TREE_CODE (t1) == BOUND_TEMPLATE_TEMPLATE_PARM)
1000 && comp_template_args (TYPE_TI_ARGS (t1), TYPE_TI_ARGS (t2)))
1003 if ((strict & COMPARE_BASE) && DERIVED_FROM_P (t1, t2))
1005 else if ((strict & COMPARE_DERIVED) && DERIVED_FROM_P (t2, t1))
1011 if (!comptypes (TYPE_OFFSET_BASETYPE (t1), TYPE_OFFSET_BASETYPE (t2),
1012 strict & ~COMPARE_REDECLARATION))
1014 if (!same_type_p (TREE_TYPE (t1), TREE_TYPE (t2)))
1018 case REFERENCE_TYPE:
1019 if (TYPE_REF_IS_RVALUE (t1) != TYPE_REF_IS_RVALUE (t2))
1021 /* fall through to checks for pointer types */
1024 if (TYPE_MODE (t1) != TYPE_MODE (t2)
1025 || TYPE_REF_CAN_ALIAS_ALL (t1) != TYPE_REF_CAN_ALIAS_ALL (t2)
1026 || !same_type_p (TREE_TYPE (t1), TREE_TYPE (t2)))
1032 if (!same_type_p (TREE_TYPE (t1), TREE_TYPE (t2)))
1034 if (!compparms (TYPE_ARG_TYPES (t1), TYPE_ARG_TYPES (t2)))
1039 /* Target types must match incl. qualifiers. */
1040 if (!comp_array_types (t1, t2, !!(strict & COMPARE_REDECLARATION)))
1044 case TEMPLATE_TYPE_PARM:
1045 if (TEMPLATE_TYPE_IDX (t1) != TEMPLATE_TYPE_IDX (t2)
1046 || TEMPLATE_TYPE_LEVEL (t1) != TEMPLATE_TYPE_LEVEL (t2)
1047 || (TEMPLATE_TYPE_PARAMETER_PACK (t1)
1048 != TEMPLATE_TYPE_PARAMETER_PACK (t2)))
1053 if (!cp_tree_equal (TYPENAME_TYPE_FULLNAME (t1),
1054 TYPENAME_TYPE_FULLNAME (t2)))
1056 if (!same_type_p (TYPE_CONTEXT (t1), TYPE_CONTEXT (t2)))
1060 case UNBOUND_CLASS_TEMPLATE:
1061 if (!cp_tree_equal (TYPE_IDENTIFIER (t1), TYPE_IDENTIFIER (t2)))
1063 if (!same_type_p (TYPE_CONTEXT (t1), TYPE_CONTEXT (t2)))
1068 if (!same_type_p (TREE_TYPE (t1), TREE_TYPE (t2)))
1073 if (TYPE_VECTOR_SUBPARTS (t1) != TYPE_VECTOR_SUBPARTS (t2)
1074 || !same_type_p (TREE_TYPE (t1), TREE_TYPE (t2)))
1078 case TYPE_PACK_EXPANSION:
1079 return same_type_p (PACK_EXPANSION_PATTERN (t1),
1080 PACK_EXPANSION_PATTERN (t2));
1083 if (DECLTYPE_TYPE_ID_EXPR_OR_MEMBER_ACCESS_P (t1)
1084 != DECLTYPE_TYPE_ID_EXPR_OR_MEMBER_ACCESS_P (t2)
1085 || !cp_tree_equal (DECLTYPE_TYPE_EXPR (t1),
1086 DECLTYPE_TYPE_EXPR (t2)))
1094 /* If we get here, we know that from a target independent POV the
1095 types are the same. Make sure the target attributes are also
1097 return targetm.comp_type_attributes (t1, t2);
1100 /* Return true if T1 and T2 are related as allowed by STRICT. STRICT
1101 is a bitwise-or of the COMPARE_* flags. */
1104 comptypes (tree t1, tree t2, int strict)
1106 if (strict == COMPARE_STRICT)
1111 if (t1 == error_mark_node || t2 == error_mark_node)
1114 if (TYPE_STRUCTURAL_EQUALITY_P (t1) || TYPE_STRUCTURAL_EQUALITY_P (t2))
1115 /* At least one of the types requires structural equality, so
1116 perform a deep check. */
1117 return structural_comptypes (t1, t2, strict);
1119 #ifdef ENABLE_CHECKING
1120 if (USE_CANONICAL_TYPES)
1122 bool result = structural_comptypes (t1, t2, strict);
1124 if (result && TYPE_CANONICAL (t1) != TYPE_CANONICAL (t2))
1125 /* The two types are structurally equivalent, but their
1126 canonical types were different. This is a failure of the
1127 canonical type propagation code.*/
1129 ("canonical types differ for identical types %T and %T",
1131 else if (!result && TYPE_CANONICAL (t1) == TYPE_CANONICAL (t2))
1132 /* Two types are structurally different, but the canonical
1133 types are the same. This means we were over-eager in
1134 assigning canonical types. */
1136 ("same canonical type node for different types %T and %T",
1142 if (USE_CANONICAL_TYPES)
1143 return TYPE_CANONICAL (t1) == TYPE_CANONICAL (t2);
1146 return structural_comptypes (t1, t2, strict);
1148 else if (strict == COMPARE_STRUCTURAL)
1149 return structural_comptypes (t1, t2, COMPARE_STRICT);
1151 return structural_comptypes (t1, t2, strict);
1154 /* Returns 1 if TYPE1 is at least as qualified as TYPE2. */
1157 at_least_as_qualified_p (tree type1, tree type2)
1159 int q1 = cp_type_quals (type1);
1160 int q2 = cp_type_quals (type2);
1162 /* All qualifiers for TYPE2 must also appear in TYPE1. */
1163 return (q1 & q2) == q2;
1166 /* Returns 1 if TYPE1 is more cv-qualified than TYPE2, -1 if TYPE2 is
1167 more cv-qualified that TYPE1, and 0 otherwise. */
1170 comp_cv_qualification (tree type1, tree type2)
1172 int q1 = cp_type_quals (type1);
1173 int q2 = cp_type_quals (type2);
1178 if ((q1 & q2) == q2)
1180 else if ((q1 & q2) == q1)
1186 /* Returns 1 if the cv-qualification signature of TYPE1 is a proper
1187 subset of the cv-qualification signature of TYPE2, and the types
1188 are similar. Returns -1 if the other way 'round, and 0 otherwise. */
1191 comp_cv_qual_signature (tree type1, tree type2)
1193 if (comp_ptr_ttypes_real (type2, type1, -1))
1195 else if (comp_ptr_ttypes_real (type1, type2, -1))
1201 /* Subroutines of `comptypes'. */
1203 /* Return true if two parameter type lists PARMS1 and PARMS2 are
1204 equivalent in the sense that functions with those parameter types
1205 can have equivalent types. The two lists must be equivalent,
1206 element by element. */
1209 compparms (tree parms1, tree parms2)
1213 /* An unspecified parmlist matches any specified parmlist
1214 whose argument types don't need default promotions. */
1216 for (t1 = parms1, t2 = parms2;
1218 t1 = TREE_CHAIN (t1), t2 = TREE_CHAIN (t2))
1220 /* If one parmlist is shorter than the other,
1221 they fail to match. */
1224 if (!same_type_p (TREE_VALUE (t1), TREE_VALUE (t2)))
1231 /* Process a sizeof or alignof expression where the operand is a
1235 cxx_sizeof_or_alignof_type (tree type, enum tree_code op, bool complain)
1240 gcc_assert (op == SIZEOF_EXPR || op == ALIGNOF_EXPR);
1241 if (type == error_mark_node)
1242 return error_mark_node;
1244 type = non_reference (type);
1245 if (TREE_CODE (type) == METHOD_TYPE)
1247 if (complain && (pedantic || warn_pointer_arith))
1248 pedwarn ("invalid application of %qs to a member function",
1249 operator_name_info[(int) op].name);
1250 value = size_one_node;
1253 dependent_p = dependent_type_p (type);
1255 complete_type (type);
1257 /* VLA types will have a non-constant size. In the body of an
1258 uninstantiated template, we don't need to try to compute the
1259 value, because the sizeof expression is not an integral
1260 constant expression in that case. And, if we do try to
1261 compute the value, we'll likely end up with SAVE_EXPRs, which
1262 the template substitution machinery does not expect to see. */
1263 || (processing_template_decl
1264 && COMPLETE_TYPE_P (type)
1265 && TREE_CODE (TYPE_SIZE (type)) != INTEGER_CST))
1267 value = build_min (op, size_type_node, type);
1268 TREE_READONLY (value) = 1;
1272 return c_sizeof_or_alignof_type (complete_type (type),
1277 /* Process a sizeof expression where the operand is an expression. */
1280 cxx_sizeof_expr (tree e)
1282 if (e == error_mark_node)
1283 return error_mark_node;
1285 if (processing_template_decl)
1287 e = build_min (SIZEOF_EXPR, size_type_node, e);
1288 TREE_SIDE_EFFECTS (e) = 0;
1289 TREE_READONLY (e) = 1;
1294 if (TREE_CODE (e) == COMPONENT_REF
1295 && TREE_CODE (TREE_OPERAND (e, 1)) == FIELD_DECL
1296 && DECL_C_BIT_FIELD (TREE_OPERAND (e, 1)))
1298 error ("invalid application of %<sizeof%> to a bit-field");
1301 else if (is_overloaded_fn (e))
1303 pedwarn ("ISO C++ forbids applying %<sizeof%> to an expression of "
1307 else if (type_unknown_p (e))
1309 cxx_incomplete_type_error (e, TREE_TYPE (e));
1315 return cxx_sizeof_or_alignof_type (e, SIZEOF_EXPR, true);
1318 /* Implement the __alignof keyword: Return the minimum required
1319 alignment of E, measured in bytes. For VAR_DECL's and
1320 FIELD_DECL's return DECL_ALIGN (which can be set from an
1321 "aligned" __attribute__ specification). */
1324 cxx_alignof_expr (tree e)
1328 if (e == error_mark_node)
1329 return error_mark_node;
1331 if (processing_template_decl)
1333 e = build_min (ALIGNOF_EXPR, size_type_node, e);
1334 TREE_SIDE_EFFECTS (e) = 0;
1335 TREE_READONLY (e) = 1;
1340 if (TREE_CODE (e) == VAR_DECL)
1341 t = size_int (DECL_ALIGN_UNIT (e));
1342 else if (TREE_CODE (e) == COMPONENT_REF
1343 && TREE_CODE (TREE_OPERAND (e, 1)) == FIELD_DECL
1344 && DECL_C_BIT_FIELD (TREE_OPERAND (e, 1)))
1346 error ("invalid application of %<__alignof%> to a bit-field");
1349 else if (TREE_CODE (e) == COMPONENT_REF
1350 && TREE_CODE (TREE_OPERAND (e, 1)) == FIELD_DECL)
1351 t = size_int (DECL_ALIGN_UNIT (TREE_OPERAND (e, 1)));
1352 else if (is_overloaded_fn (e))
1354 pedwarn ("ISO C++ forbids applying %<__alignof%> to an expression of "
1356 if (TREE_CODE (e) == FUNCTION_DECL)
1357 t = size_int (DECL_ALIGN_UNIT (e));
1361 else if (type_unknown_p (e))
1363 cxx_incomplete_type_error (e, TREE_TYPE (e));
1367 return cxx_sizeof_or_alignof_type (TREE_TYPE (e), ALIGNOF_EXPR, true);
1369 return fold_convert (size_type_node, t);
1372 /* Process a sizeof or alignof expression E with code OP where the operand
1373 is an expression. */
1376 cxx_sizeof_or_alignof_expr (tree e, enum tree_code op)
1378 if (op == SIZEOF_EXPR)
1379 return cxx_sizeof_expr (e);
1381 return cxx_alignof_expr (e);
1384 /* EXPR is being used in a context that is not a function call.
1389 The expression can be used only as the left-hand operand of a
1390 member function call.
1392 [expr.mptr.operator]
1394 If the result of .* or ->* is a function, then that result can be
1395 used only as the operand for the function call operator ().
1397 by issuing an error message if appropriate. Returns true iff EXPR
1398 violates these rules. */
1401 invalid_nonstatic_memfn_p (tree expr)
1403 if (TREE_CODE (TREE_TYPE (expr)) == METHOD_TYPE)
1405 error ("invalid use of non-static member function");
1411 /* If EXP is a reference to a bitfield, and the type of EXP does not
1412 match the declared type of the bitfield, return the declared type
1413 of the bitfield. Otherwise, return NULL_TREE. */
1416 is_bitfield_expr_with_lowered_type (tree exp)
1418 switch (TREE_CODE (exp))
1421 if (!is_bitfield_expr_with_lowered_type (TREE_OPERAND (exp, 1)))
1423 return is_bitfield_expr_with_lowered_type (TREE_OPERAND (exp, 2));
1426 return is_bitfield_expr_with_lowered_type (TREE_OPERAND (exp, 1));
1430 return is_bitfield_expr_with_lowered_type (TREE_OPERAND (exp, 0));
1436 field = TREE_OPERAND (exp, 1);
1437 if (TREE_CODE (field) != FIELD_DECL || !DECL_C_BIT_FIELD (field))
1439 if (same_type_ignoring_top_level_qualifiers_p
1440 (TREE_TYPE (exp), DECL_BIT_FIELD_TYPE (field)))
1442 return DECL_BIT_FIELD_TYPE (field);
1450 /* Like is_bitfield_with_lowered_type, except that if EXP is not a
1451 bitfield with a lowered type, the type of EXP is returned, rather
1455 unlowered_expr_type (tree exp)
1459 type = is_bitfield_expr_with_lowered_type (exp);
1461 type = TREE_TYPE (exp);
1466 /* Perform the conversions in [expr] that apply when an lvalue appears
1467 in an rvalue context: the lvalue-to-rvalue, array-to-pointer, and
1468 function-to-pointer conversions. In addition, manifest constants
1469 are replaced by their values, and bitfield references are converted
1470 to their declared types.
1472 Although the returned value is being used as an rvalue, this
1473 function does not wrap the returned expression in a
1474 NON_LVALUE_EXPR; the caller is expected to be mindful of the fact
1475 that the return value is no longer an lvalue. */
1478 decay_conversion (tree exp)
1481 enum tree_code code;
1483 type = TREE_TYPE (exp);
1484 if (type == error_mark_node)
1485 return error_mark_node;
1487 if (type_unknown_p (exp))
1489 cxx_incomplete_type_error (exp, TREE_TYPE (exp));
1490 return error_mark_node;
1493 exp = decl_constant_value (exp);
1494 if (error_operand_p (exp))
1495 return error_mark_node;
1497 /* build_c_cast puts on a NOP_EXPR to make the result not an lvalue.
1498 Leave such NOP_EXPRs, since RHS is being used in non-lvalue context. */
1499 code = TREE_CODE (type);
1500 if (code == VOID_TYPE)
1502 error ("void value not ignored as it ought to be");
1503 return error_mark_node;
1505 if (invalid_nonstatic_memfn_p (exp))
1506 return error_mark_node;
1507 if (code == FUNCTION_TYPE || is_overloaded_fn (exp))
1508 return build_unary_op (ADDR_EXPR, exp, 0);
1509 if (code == ARRAY_TYPE)
1514 if (TREE_CODE (exp) == INDIRECT_REF)
1515 return build_nop (build_pointer_type (TREE_TYPE (type)),
1516 TREE_OPERAND (exp, 0));
1518 if (TREE_CODE (exp) == COMPOUND_EXPR)
1520 tree op1 = decay_conversion (TREE_OPERAND (exp, 1));
1521 return build2 (COMPOUND_EXPR, TREE_TYPE (op1),
1522 TREE_OPERAND (exp, 0), op1);
1526 && ! (TREE_CODE (exp) == CONSTRUCTOR && TREE_STATIC (exp)))
1528 error ("invalid use of non-lvalue array");
1529 return error_mark_node;
1532 ptrtype = build_pointer_type (TREE_TYPE (type));
1534 if (TREE_CODE (exp) == VAR_DECL)
1536 if (!cxx_mark_addressable (exp))
1537 return error_mark_node;
1538 adr = build_nop (ptrtype, build_address (exp));
1541 /* This way is better for a COMPONENT_REF since it can
1542 simplify the offset for a component. */
1543 adr = build_unary_op (ADDR_EXPR, exp, 1);
1544 return cp_convert (ptrtype, adr);
1547 /* If a bitfield is used in a context where integral promotion
1548 applies, then the caller is expected to have used
1549 default_conversion. That function promotes bitfields correctly
1550 before calling this function. At this point, if we have a
1551 bitfield referenced, we may assume that is not subject to
1552 promotion, and that, therefore, the type of the resulting rvalue
1553 is the declared type of the bitfield. */
1554 exp = convert_bitfield_to_declared_type (exp);
1556 /* We do not call rvalue() here because we do not want to wrap EXP
1557 in a NON_LVALUE_EXPR. */
1561 Non-class rvalues always have cv-unqualified types. */
1562 type = TREE_TYPE (exp);
1563 if (!CLASS_TYPE_P (type) && cp_type_quals (type))
1564 exp = build_nop (TYPE_MAIN_VARIANT (type), exp);
1569 /* Perform prepatory conversions, as part of the "usual arithmetic
1570 conversions". In particular, as per [expr]:
1572 Whenever an lvalue expression appears as an operand of an
1573 operator that expects the rvalue for that operand, the
1574 lvalue-to-rvalue, array-to-pointer, or function-to-pointer
1575 standard conversions are applied to convert the expression to an
1578 In addition, we perform integral promotions here, as those are
1579 applied to both operands to a binary operator before determining
1580 what additional conversions should apply. */
1583 default_conversion (tree exp)
1585 /* Perform the integral promotions first so that bitfield
1586 expressions (which may promote to "int", even if the bitfield is
1587 declared "unsigned") are promoted correctly. */
1588 if (INTEGRAL_OR_ENUMERATION_TYPE_P (TREE_TYPE (exp)))
1589 exp = perform_integral_promotions (exp);
1590 /* Perform the other conversions. */
1591 exp = decay_conversion (exp);
1596 /* EXPR is an expression with an integral or enumeration type.
1597 Perform the integral promotions in [conv.prom], and return the
1601 perform_integral_promotions (tree expr)
1608 If the bitfield has an enumerated type, it is treated as any
1609 other value of that type for promotion purposes. */
1610 type = is_bitfield_expr_with_lowered_type (expr);
1611 if (!type || TREE_CODE (type) != ENUMERAL_TYPE)
1612 type = TREE_TYPE (expr);
1613 gcc_assert (INTEGRAL_OR_ENUMERATION_TYPE_P (type));
1614 promoted_type = type_promotes_to (type);
1615 if (type != promoted_type)
1616 expr = cp_convert (promoted_type, expr);
1620 /* Take the address of an inline function without setting TREE_ADDRESSABLE
1624 inline_conversion (tree exp)
1626 if (TREE_CODE (exp) == FUNCTION_DECL)
1627 exp = build1 (ADDR_EXPR, build_pointer_type (TREE_TYPE (exp)), exp);
1632 /* Returns nonzero iff exp is a STRING_CST or the result of applying
1633 decay_conversion to one. */
1636 string_conv_p (tree totype, tree exp, int warn)
1640 if (TREE_CODE (totype) != POINTER_TYPE)
1643 t = TREE_TYPE (totype);
1644 if (!same_type_p (t, char_type_node)
1645 && !same_type_p (t, wchar_type_node))
1648 if (TREE_CODE (exp) == STRING_CST)
1650 /* Make sure that we don't try to convert between char and wchar_t. */
1651 if (!same_type_p (TYPE_MAIN_VARIANT (TREE_TYPE (TREE_TYPE (exp))), t))
1656 /* Is this a string constant which has decayed to 'const char *'? */
1657 t = build_pointer_type (build_qualified_type (t, TYPE_QUAL_CONST));
1658 if (!same_type_p (TREE_TYPE (exp), t))
1661 if (TREE_CODE (exp) != ADDR_EXPR
1662 || TREE_CODE (TREE_OPERAND (exp, 0)) != STRING_CST)
1666 /* This warning is not very useful, as it complains about printf. */
1668 warning (OPT_Wwrite_strings,
1669 "deprecated conversion from string constant to %qT",
1675 /* Given a COND_EXPR, MIN_EXPR, or MAX_EXPR in T, return it in a form that we
1676 can, for example, use as an lvalue. This code used to be in
1677 unary_complex_lvalue, but we needed it to deal with `a = (d == c) ? b : c'
1678 expressions, where we're dealing with aggregates. But now it's again only
1679 called from unary_complex_lvalue. The case (in particular) that led to
1680 this was with CODE == ADDR_EXPR, since it's not an lvalue when we'd
1684 rationalize_conditional_expr (enum tree_code code, tree t)
1686 /* For MIN_EXPR or MAX_EXPR, fold-const.c has arranged things so that
1687 the first operand is always the one to be used if both operands
1688 are equal, so we know what conditional expression this used to be. */
1689 if (TREE_CODE (t) == MIN_EXPR || TREE_CODE (t) == MAX_EXPR)
1691 tree op0 = TREE_OPERAND (t, 0);
1692 tree op1 = TREE_OPERAND (t, 1);
1694 /* The following code is incorrect if either operand side-effects. */
1695 gcc_assert (!TREE_SIDE_EFFECTS (op0)
1696 && !TREE_SIDE_EFFECTS (op1));
1698 build_conditional_expr (build_x_binary_op ((TREE_CODE (t) == MIN_EXPR
1699 ? LE_EXPR : GE_EXPR),
1700 op0, TREE_CODE (op0),
1701 op1, TREE_CODE (op1),
1702 /*overloaded_p=*/NULL),
1703 build_unary_op (code, op0, 0),
1704 build_unary_op (code, op1, 0));
1708 build_conditional_expr (TREE_OPERAND (t, 0),
1709 build_unary_op (code, TREE_OPERAND (t, 1), 0),
1710 build_unary_op (code, TREE_OPERAND (t, 2), 0));
1713 /* Given the TYPE of an anonymous union field inside T, return the
1714 FIELD_DECL for the field. If not found return NULL_TREE. Because
1715 anonymous unions can nest, we must also search all anonymous unions
1716 that are directly reachable. */
1719 lookup_anon_field (tree t, tree type)
1723 for (field = TYPE_FIELDS (t); field; field = TREE_CHAIN (field))
1725 if (TREE_STATIC (field))
1727 if (TREE_CODE (field) != FIELD_DECL || DECL_ARTIFICIAL (field))
1730 /* If we find it directly, return the field. */
1731 if (DECL_NAME (field) == NULL_TREE
1732 && type == TYPE_MAIN_VARIANT (TREE_TYPE (field)))
1737 /* Otherwise, it could be nested, search harder. */
1738 if (DECL_NAME (field) == NULL_TREE
1739 && ANON_AGGR_TYPE_P (TREE_TYPE (field)))
1741 tree subfield = lookup_anon_field (TREE_TYPE (field), type);
1749 /* Build an expression representing OBJECT.MEMBER. OBJECT is an
1750 expression; MEMBER is a DECL or baselink. If ACCESS_PATH is
1751 non-NULL, it indicates the path to the base used to name MEMBER.
1752 If PRESERVE_REFERENCE is true, the expression returned will have
1753 REFERENCE_TYPE if the MEMBER does. Otherwise, the expression
1754 returned will have the type referred to by the reference.
1756 This function does not perform access control; that is either done
1757 earlier by the parser when the name of MEMBER is resolved to MEMBER
1758 itself, or later when overload resolution selects one of the
1759 functions indicated by MEMBER. */
1762 build_class_member_access_expr (tree object, tree member,
1763 tree access_path, bool preserve_reference)
1767 tree result = NULL_TREE;
1769 if (error_operand_p (object) || error_operand_p (member))
1770 return error_mark_node;
1772 gcc_assert (DECL_P (member) || BASELINK_P (member));
1776 The type of the first expression shall be "class object" (of a
1778 object_type = TREE_TYPE (object);
1779 if (!currently_open_class (object_type)
1780 && !complete_type_or_else (object_type, object))
1781 return error_mark_node;
1782 if (!CLASS_TYPE_P (object_type))
1784 error ("request for member %qD in %qE, which is of non-class type %qT",
1785 member, object, object_type);
1786 return error_mark_node;
1789 /* The standard does not seem to actually say that MEMBER must be a
1790 member of OBJECT_TYPE. However, that is clearly what is
1792 if (DECL_P (member))
1794 member_scope = DECL_CLASS_CONTEXT (member);
1796 if (TREE_DEPRECATED (member))
1797 warn_deprecated_use (member);
1800 member_scope = BINFO_TYPE (BASELINK_BINFO (member));
1801 /* If MEMBER is from an anonymous aggregate, MEMBER_SCOPE will
1802 presently be the anonymous union. Go outwards until we find a
1803 type related to OBJECT_TYPE. */
1804 while (ANON_AGGR_TYPE_P (member_scope)
1805 && !same_type_ignoring_top_level_qualifiers_p (member_scope,
1807 member_scope = TYPE_CONTEXT (member_scope);
1808 if (!member_scope || !DERIVED_FROM_P (member_scope, object_type))
1810 if (TREE_CODE (member) == FIELD_DECL)
1811 error ("invalid use of nonstatic data member %qE", member);
1813 error ("%qD is not a member of %qT", member, object_type);
1814 return error_mark_node;
1817 /* Transform `(a, b).x' into `(*(a, &b)).x', `(a ? b : c).x' into
1818 `(*(a ? &b : &c)).x', and so on. A COND_EXPR is only an lvalue
1819 in the front end; only _DECLs and _REFs are lvalues in the back end. */
1821 tree temp = unary_complex_lvalue (ADDR_EXPR, object);
1823 object = build_indirect_ref (temp, NULL);
1826 /* In [expr.ref], there is an explicit list of the valid choices for
1827 MEMBER. We check for each of those cases here. */
1828 if (TREE_CODE (member) == VAR_DECL)
1830 /* A static data member. */
1832 /* If OBJECT has side-effects, they are supposed to occur. */
1833 if (TREE_SIDE_EFFECTS (object))
1834 result = build2 (COMPOUND_EXPR, TREE_TYPE (result), object, result);
1836 else if (TREE_CODE (member) == FIELD_DECL)
1838 /* A non-static data member. */
1843 null_object_p = (TREE_CODE (object) == INDIRECT_REF
1844 && integer_zerop (TREE_OPERAND (object, 0)));
1846 /* Convert OBJECT to the type of MEMBER. */
1847 if (!same_type_p (TYPE_MAIN_VARIANT (object_type),
1848 TYPE_MAIN_VARIANT (member_scope)))
1853 binfo = lookup_base (access_path ? access_path : object_type,
1854 member_scope, ba_unique, &kind);
1855 if (binfo == error_mark_node)
1856 return error_mark_node;
1858 /* It is invalid to try to get to a virtual base of a
1859 NULL object. The most common cause is invalid use of
1861 if (null_object_p && kind == bk_via_virtual)
1863 error ("invalid access to non-static data member %qD of "
1866 error ("(perhaps the %<offsetof%> macro was used incorrectly)");
1867 return error_mark_node;
1870 /* Convert to the base. */
1871 object = build_base_path (PLUS_EXPR, object, binfo,
1873 /* If we found the base successfully then we should be able
1874 to convert to it successfully. */
1875 gcc_assert (object != error_mark_node);
1878 /* Complain about other invalid uses of offsetof, even though they will
1879 give the right answer. Note that we complain whether or not they
1880 actually used the offsetof macro, since there's no way to know at this
1881 point. So we just give a warning, instead of a pedwarn. */
1882 /* Do not produce this warning for base class field references, because
1883 we know for a fact that didn't come from offsetof. This does occur
1884 in various testsuite cases where a null object is passed where a
1885 vtable access is required. */
1886 if (null_object_p && warn_invalid_offsetof
1887 && CLASSTYPE_NON_POD_P (object_type)
1888 && !DECL_FIELD_IS_BASE (member)
1889 && !skip_evaluation)
1891 warning (0, "invalid access to non-static data member %qD of NULL object",
1893 warning (0, "(perhaps the %<offsetof%> macro was used incorrectly)");
1896 /* If MEMBER is from an anonymous aggregate, we have converted
1897 OBJECT so that it refers to the class containing the
1898 anonymous union. Generate a reference to the anonymous union
1899 itself, and recur to find MEMBER. */
1900 if (ANON_AGGR_TYPE_P (DECL_CONTEXT (member))
1901 /* When this code is called from build_field_call, the
1902 object already has the type of the anonymous union.
1903 That is because the COMPONENT_REF was already
1904 constructed, and was then disassembled before calling
1905 build_field_call. After the function-call code is
1906 cleaned up, this waste can be eliminated. */
1907 && (!same_type_ignoring_top_level_qualifiers_p
1908 (TREE_TYPE (object), DECL_CONTEXT (member))))
1910 tree anonymous_union;
1912 anonymous_union = lookup_anon_field (TREE_TYPE (object),
1913 DECL_CONTEXT (member));
1914 object = build_class_member_access_expr (object,
1916 /*access_path=*/NULL_TREE,
1917 preserve_reference);
1920 /* Compute the type of the field, as described in [expr.ref]. */
1921 type_quals = TYPE_UNQUALIFIED;
1922 member_type = TREE_TYPE (member);
1923 if (TREE_CODE (member_type) != REFERENCE_TYPE)
1925 type_quals = (cp_type_quals (member_type)
1926 | cp_type_quals (object_type));
1928 /* A field is const (volatile) if the enclosing object, or the
1929 field itself, is const (volatile). But, a mutable field is
1930 not const, even within a const object. */
1931 if (DECL_MUTABLE_P (member))
1932 type_quals &= ~TYPE_QUAL_CONST;
1933 member_type = cp_build_qualified_type (member_type, type_quals);
1936 result = build3 (COMPONENT_REF, member_type, object, member,
1938 result = fold_if_not_in_template (result);
1940 /* Mark the expression const or volatile, as appropriate. Even
1941 though we've dealt with the type above, we still have to mark the
1942 expression itself. */
1943 if (type_quals & TYPE_QUAL_CONST)
1944 TREE_READONLY (result) = 1;
1945 if (type_quals & TYPE_QUAL_VOLATILE)
1946 TREE_THIS_VOLATILE (result) = 1;
1948 else if (BASELINK_P (member))
1950 /* The member is a (possibly overloaded) member function. */
1954 /* If the MEMBER is exactly one static member function, then we
1955 know the type of the expression. Otherwise, we must wait
1956 until overload resolution has been performed. */
1957 functions = BASELINK_FUNCTIONS (member);
1958 if (TREE_CODE (functions) == FUNCTION_DECL
1959 && DECL_STATIC_FUNCTION_P (functions))
1960 type = TREE_TYPE (functions);
1962 type = unknown_type_node;
1963 /* Note that we do not convert OBJECT to the BASELINK_BINFO
1964 base. That will happen when the function is called. */
1965 result = build3 (COMPONENT_REF, type, object, member, NULL_TREE);
1967 else if (TREE_CODE (member) == CONST_DECL)
1969 /* The member is an enumerator. */
1971 /* If OBJECT has side-effects, they are supposed to occur. */
1972 if (TREE_SIDE_EFFECTS (object))
1973 result = build2 (COMPOUND_EXPR, TREE_TYPE (result),
1978 error ("invalid use of %qD", member);
1979 return error_mark_node;
1982 if (!preserve_reference)
1985 If E2 is declared to have type "reference to T", then ... the
1986 type of E1.E2 is T. */
1987 result = convert_from_reference (result);
1992 /* Return the destructor denoted by OBJECT.SCOPE::~DTOR_NAME, or, if
1993 SCOPE is NULL, by OBJECT.~DTOR_NAME. */
1996 lookup_destructor (tree object, tree scope, tree dtor_name)
1998 tree object_type = TREE_TYPE (object);
1999 tree dtor_type = TREE_OPERAND (dtor_name, 0);
2002 if (scope && !check_dtor_name (scope, dtor_type))
2004 error ("qualified type %qT does not match destructor name ~%qT",
2006 return error_mark_node;
2008 if (!DERIVED_FROM_P (dtor_type, TYPE_MAIN_VARIANT (object_type)))
2010 error ("the type being destroyed is %qT, but the destructor refers to %qT",
2011 TYPE_MAIN_VARIANT (object_type), dtor_type);
2012 return error_mark_node;
2014 expr = lookup_member (dtor_type, complete_dtor_identifier,
2015 /*protect=*/1, /*want_type=*/false);
2016 expr = (adjust_result_of_qualified_name_lookup
2017 (expr, dtor_type, object_type));
2021 /* An expression of the form "A::template B" has been resolved to
2022 DECL. Issue a diagnostic if B is not a template or template
2026 check_template_keyword (tree decl)
2028 /* The standard says:
2032 If a name prefixed by the keyword template is not a member
2033 template, the program is ill-formed.
2035 DR 228 removed the restriction that the template be a member
2038 DR 96, if accepted would add the further restriction that explicit
2039 template arguments must be provided if the template keyword is
2040 used, but, as of 2005-10-16, that DR is still in "drafting". If
2041 this DR is accepted, then the semantic checks here can be
2042 simplified, as the entity named must in fact be a template
2043 specialization, rather than, as at present, a set of overloaded
2044 functions containing at least one template function. */
2045 if (TREE_CODE (decl) != TEMPLATE_DECL
2046 && TREE_CODE (decl) != TEMPLATE_ID_EXPR)
2048 if (!is_overloaded_fn (decl))
2049 pedwarn ("%qD is not a template", decl);
2054 if (BASELINK_P (fns))
2055 fns = BASELINK_FUNCTIONS (fns);
2058 tree fn = OVL_CURRENT (fns);
2059 if (TREE_CODE (fn) == TEMPLATE_DECL
2060 || TREE_CODE (fn) == TEMPLATE_ID_EXPR)
2062 if (TREE_CODE (fn) == FUNCTION_DECL
2063 && DECL_USE_TEMPLATE (fn)
2064 && PRIMARY_TEMPLATE_P (DECL_TI_TEMPLATE (fn)))
2066 fns = OVL_NEXT (fns);
2069 pedwarn ("%qD is not a template", decl);
2074 /* This function is called by the parser to process a class member
2075 access expression of the form OBJECT.NAME. NAME is a node used by
2076 the parser to represent a name; it is not yet a DECL. It may,
2077 however, be a BASELINK where the BASELINK_FUNCTIONS is a
2078 TEMPLATE_ID_EXPR. Templates must be looked up by the parser, and
2079 there is no reason to do the lookup twice, so the parser keeps the
2080 BASELINK. TEMPLATE_P is true iff NAME was explicitly declared to
2081 be a template via the use of the "A::template B" syntax. */
2084 finish_class_member_access_expr (tree object, tree name, bool template_p)
2089 tree access_path = NULL_TREE;
2090 tree orig_object = object;
2091 tree orig_name = name;
2093 if (object == error_mark_node || name == error_mark_node)
2094 return error_mark_node;
2096 /* If OBJECT is an ObjC class instance, we must obey ObjC access rules. */
2097 if (!objc_is_public (object, name))
2098 return error_mark_node;
2100 object_type = TREE_TYPE (object);
2102 if (processing_template_decl)
2104 if (/* If OBJECT_TYPE is dependent, so is OBJECT.NAME. */
2105 dependent_type_p (object_type)
2106 /* If NAME is just an IDENTIFIER_NODE, then the expression
2108 || TREE_CODE (object) == IDENTIFIER_NODE
2109 /* If NAME is "f<args>", where either 'f' or 'args' is
2110 dependent, then the expression is dependent. */
2111 || (TREE_CODE (name) == TEMPLATE_ID_EXPR
2112 && dependent_template_id_p (TREE_OPERAND (name, 0),
2113 TREE_OPERAND (name, 1)))
2114 /* If NAME is "T::X" where "T" is dependent, then the
2115 expression is dependent. */
2116 || (TREE_CODE (name) == SCOPE_REF
2117 && TYPE_P (TREE_OPERAND (name, 0))
2118 && dependent_type_p (TREE_OPERAND (name, 0))))
2119 return build_min_nt (COMPONENT_REF, object, name, NULL_TREE);
2120 object = build_non_dependent_expr (object);
2125 The type of the first expression shall be "class object" (of a
2127 if (!currently_open_class (object_type)
2128 && !complete_type_or_else (object_type, object))
2129 return error_mark_node;
2130 if (!CLASS_TYPE_P (object_type))
2132 error ("request for member %qD in %qE, which is of non-class type %qT",
2133 name, object, object_type);
2134 return error_mark_node;
2137 if (BASELINK_P (name))
2138 /* A member function that has already been looked up. */
2142 bool is_template_id = false;
2143 tree template_args = NULL_TREE;
2146 if (TREE_CODE (name) == TEMPLATE_ID_EXPR)
2148 is_template_id = true;
2149 template_args = TREE_OPERAND (name, 1);
2150 name = TREE_OPERAND (name, 0);
2152 if (TREE_CODE (name) == OVERLOAD)
2153 name = DECL_NAME (get_first_fn (name));
2154 else if (DECL_P (name))
2155 name = DECL_NAME (name);
2158 if (TREE_CODE (name) == SCOPE_REF)
2160 /* A qualified name. The qualifying class or namespace `S'
2161 has already been looked up; it is either a TYPE or a
2163 scope = TREE_OPERAND (name, 0);
2164 name = TREE_OPERAND (name, 1);
2166 /* If SCOPE is a namespace, then the qualified name does not
2167 name a member of OBJECT_TYPE. */
2168 if (TREE_CODE (scope) == NAMESPACE_DECL)
2170 error ("%<%D::%D%> is not a member of %qT",
2171 scope, name, object_type);
2172 return error_mark_node;
2175 gcc_assert (CLASS_TYPE_P (scope));
2176 gcc_assert (TREE_CODE (name) == IDENTIFIER_NODE
2177 || TREE_CODE (name) == BIT_NOT_EXPR);
2179 /* Find the base of OBJECT_TYPE corresponding to SCOPE. */
2180 access_path = lookup_base (object_type, scope, ba_check, NULL);
2181 if (access_path == error_mark_node)
2182 return error_mark_node;
2185 error ("%qT is not a base of %qT", scope, object_type);
2186 return error_mark_node;
2192 access_path = object_type;
2195 if (TREE_CODE (name) == BIT_NOT_EXPR)
2196 member = lookup_destructor (object, scope, name);
2199 /* Look up the member. */
2200 member = lookup_member (access_path, name, /*protect=*/1,
2201 /*want_type=*/false);
2202 if (member == NULL_TREE)
2204 error ("%qD has no member named %qE", object_type, name);
2205 return error_mark_node;
2207 if (member == error_mark_node)
2208 return error_mark_node;
2213 tree template = member;
2215 if (BASELINK_P (template))
2216 template = lookup_template_function (template, template_args);
2219 error ("%qD is not a member template function", name);
2220 return error_mark_node;
2225 if (TREE_DEPRECATED (member))
2226 warn_deprecated_use (member);
2229 check_template_keyword (member);
2231 expr = build_class_member_access_expr (object, member, access_path,
2232 /*preserve_reference=*/false);
2233 if (processing_template_decl && expr != error_mark_node)
2235 if (BASELINK_P (member))
2237 if (TREE_CODE (orig_name) == SCOPE_REF)
2238 BASELINK_QUALIFIED_P (member) = 1;
2241 return build_min_non_dep (COMPONENT_REF, expr,
2242 orig_object, orig_name,
2249 /* Return an expression for the MEMBER_NAME field in the internal
2250 representation of PTRMEM, a pointer-to-member function. (Each
2251 pointer-to-member function type gets its own RECORD_TYPE so it is
2252 more convenient to access the fields by name than by FIELD_DECL.)
2253 This routine converts the NAME to a FIELD_DECL and then creates the
2254 node for the complete expression. */
2257 build_ptrmemfunc_access_expr (tree ptrmem, tree member_name)
2263 /* This code is a stripped down version of
2264 build_class_member_access_expr. It does not work to use that
2265 routine directly because it expects the object to be of class
2267 ptrmem_type = TREE_TYPE (ptrmem);
2268 gcc_assert (TYPE_PTRMEMFUNC_P (ptrmem_type));
2269 member = lookup_member (ptrmem_type, member_name, /*protect=*/0,
2270 /*want_type=*/false);
2271 member_type = cp_build_qualified_type (TREE_TYPE (member),
2272 cp_type_quals (ptrmem_type));
2273 return fold_build3 (COMPONENT_REF, member_type,
2274 ptrmem, member, NULL_TREE);
2277 /* Given an expression PTR for a pointer, return an expression
2278 for the value pointed to.
2279 ERRORSTRING is the name of the operator to appear in error messages.
2281 This function may need to overload OPERATOR_FNNAME.
2282 Must also handle REFERENCE_TYPEs for C++. */
2285 build_x_indirect_ref (tree expr, const char *errorstring)
2287 tree orig_expr = expr;
2290 if (processing_template_decl)
2292 if (type_dependent_expression_p (expr))
2293 return build_min_nt (INDIRECT_REF, expr);
2294 expr = build_non_dependent_expr (expr);
2297 rval = build_new_op (INDIRECT_REF, LOOKUP_NORMAL, expr, NULL_TREE,
2298 NULL_TREE, /*overloaded_p=*/NULL);
2300 rval = build_indirect_ref (expr, errorstring);
2302 if (processing_template_decl && rval != error_mark_node)
2303 return build_min_non_dep (INDIRECT_REF, rval, orig_expr);
2309 build_indirect_ref (tree ptr, const char *errorstring)
2313 if (ptr == error_mark_node)
2314 return error_mark_node;
2316 if (ptr == current_class_ptr)
2317 return current_class_ref;
2319 pointer = (TREE_CODE (TREE_TYPE (ptr)) == REFERENCE_TYPE
2320 ? ptr : decay_conversion (ptr));
2321 type = TREE_TYPE (pointer);
2323 if (POINTER_TYPE_P (type))
2327 If the type of the expression is "pointer to T," the type
2328 of the result is "T."
2330 We must use the canonical variant because certain parts of
2331 the back end, like fold, do pointer comparisons between
2333 tree t = canonical_type_variant (TREE_TYPE (type));
2335 if (TREE_CODE (ptr) == CONVERT_EXPR
2336 || TREE_CODE (ptr) == NOP_EXPR
2337 || TREE_CODE (ptr) == VIEW_CONVERT_EXPR)
2339 /* If a warning is issued, mark it to avoid duplicates from
2340 the backend. This only needs to be done at
2341 warn_strict_aliasing > 2. */
2342 if (warn_strict_aliasing > 2)
2343 if (strict_aliasing_warning (TREE_TYPE (TREE_OPERAND (ptr, 0)),
2344 type, TREE_OPERAND (ptr, 0)))
2345 TREE_NO_WARNING (ptr) = 1;
2348 if (VOID_TYPE_P (t))
2350 /* A pointer to incomplete type (other than cv void) can be
2351 dereferenced [expr.unary.op]/1 */
2352 error ("%qT is not a pointer-to-object type", type);
2353 return error_mark_node;
2355 else if (TREE_CODE (pointer) == ADDR_EXPR
2356 && same_type_p (t, TREE_TYPE (TREE_OPERAND (pointer, 0))))
2357 /* The POINTER was something like `&x'. We simplify `*&x' to
2359 return TREE_OPERAND (pointer, 0);
2362 tree ref = build1 (INDIRECT_REF, t, pointer);
2364 /* We *must* set TREE_READONLY when dereferencing a pointer to const,
2365 so that we get the proper error message if the result is used
2366 to assign to. Also, &* is supposed to be a no-op. */
2367 TREE_READONLY (ref) = CP_TYPE_CONST_P (t);
2368 TREE_THIS_VOLATILE (ref) = CP_TYPE_VOLATILE_P (t);
2369 TREE_SIDE_EFFECTS (ref)
2370 = (TREE_THIS_VOLATILE (ref) || TREE_SIDE_EFFECTS (pointer));
2374 /* `pointer' won't be an error_mark_node if we were given a
2375 pointer to member, so it's cool to check for this here. */
2376 else if (TYPE_PTR_TO_MEMBER_P (type))
2377 error ("invalid use of %qs on pointer to member", errorstring);
2378 else if (pointer != error_mark_node)
2381 error ("invalid type argument of %qs", errorstring);
2383 error ("invalid type argument");
2385 return error_mark_node;
2388 /* This handles expressions of the form "a[i]", which denotes
2391 This is logically equivalent in C to *(a+i), but we may do it differently.
2392 If A is a variable or a member, we generate a primitive ARRAY_REF.
2393 This avoids forcing the array out of registers, and can work on
2394 arrays that are not lvalues (for example, members of structures returned
2397 If INDEX is of some user-defined type, it must be converted to
2398 integer type. Otherwise, to make a compatible PLUS_EXPR, it
2399 will inherit the type of the array, which will be some pointer type. */
2402 build_array_ref (tree array, tree idx)
2406 error ("subscript missing in array reference");
2407 return error_mark_node;
2410 if (TREE_TYPE (array) == error_mark_node
2411 || TREE_TYPE (idx) == error_mark_node)
2412 return error_mark_node;
2414 /* If ARRAY is a COMPOUND_EXPR or COND_EXPR, move our reference
2416 switch (TREE_CODE (array))
2420 tree value = build_array_ref (TREE_OPERAND (array, 1), idx);
2421 return build2 (COMPOUND_EXPR, TREE_TYPE (value),
2422 TREE_OPERAND (array, 0), value);
2426 return build_conditional_expr
2427 (TREE_OPERAND (array, 0),
2428 build_array_ref (TREE_OPERAND (array, 1), idx),
2429 build_array_ref (TREE_OPERAND (array, 2), idx));
2435 if (TREE_CODE (TREE_TYPE (array)) == ARRAY_TYPE)
2439 warn_array_subscript_with_type_char (idx);
2441 if (!INTEGRAL_OR_ENUMERATION_TYPE_P (TREE_TYPE (idx)))
2443 error ("array subscript is not an integer");
2444 return error_mark_node;
2447 /* Apply integral promotions *after* noticing character types.
2448 (It is unclear why we do these promotions -- the standard
2449 does not say that we should. In fact, the natural thing would
2450 seem to be to convert IDX to ptrdiff_t; we're performing
2451 pointer arithmetic.) */
2452 idx = perform_integral_promotions (idx);
2454 /* An array that is indexed by a non-constant
2455 cannot be stored in a register; we must be able to do
2456 address arithmetic on its address.
2457 Likewise an array of elements of variable size. */
2458 if (TREE_CODE (idx) != INTEGER_CST
2459 || (COMPLETE_TYPE_P (TREE_TYPE (TREE_TYPE (array)))
2460 && (TREE_CODE (TYPE_SIZE (TREE_TYPE (TREE_TYPE (array))))
2463 if (!cxx_mark_addressable (array))
2464 return error_mark_node;
2467 /* An array that is indexed by a constant value which is not within
2468 the array bounds cannot be stored in a register either; because we
2469 would get a crash in store_bit_field/extract_bit_field when trying
2470 to access a non-existent part of the register. */
2471 if (TREE_CODE (idx) == INTEGER_CST
2472 && TYPE_DOMAIN (TREE_TYPE (array))
2473 && ! int_fits_type_p (idx, TYPE_DOMAIN (TREE_TYPE (array))))
2475 if (!cxx_mark_addressable (array))
2476 return error_mark_node;
2479 if (pedantic && !lvalue_p (array))
2480 pedwarn ("ISO C++ forbids subscripting non-lvalue array");
2482 /* Note in C++ it is valid to subscript a `register' array, since
2483 it is valid to take the address of something with that
2484 storage specification. */
2488 while (TREE_CODE (foo) == COMPONENT_REF)
2489 foo = TREE_OPERAND (foo, 0);
2490 if (TREE_CODE (foo) == VAR_DECL && DECL_REGISTER (foo))
2491 warning (OPT_Wextra, "subscripting array declared %<register%>");
2494 type = TREE_TYPE (TREE_TYPE (array));
2495 rval = build4 (ARRAY_REF, type, array, idx, NULL_TREE, NULL_TREE);
2496 /* Array ref is const/volatile if the array elements are
2497 or if the array is.. */
2498 TREE_READONLY (rval)
2499 |= (CP_TYPE_CONST_P (type) | TREE_READONLY (array));
2500 TREE_SIDE_EFFECTS (rval)
2501 |= (CP_TYPE_VOLATILE_P (type) | TREE_SIDE_EFFECTS (array));
2502 TREE_THIS_VOLATILE (rval)
2503 |= (CP_TYPE_VOLATILE_P (type) | TREE_THIS_VOLATILE (array));
2504 return require_complete_type (fold_if_not_in_template (rval));
2508 tree ar = default_conversion (array);
2509 tree ind = default_conversion (idx);
2511 /* Put the integer in IND to simplify error checking. */
2512 if (TREE_CODE (TREE_TYPE (ar)) == INTEGER_TYPE)
2519 if (ar == error_mark_node)
2522 if (TREE_CODE (TREE_TYPE (ar)) != POINTER_TYPE)
2524 error ("subscripted value is neither array nor pointer");
2525 return error_mark_node;
2527 if (TREE_CODE (TREE_TYPE (ind)) != INTEGER_TYPE)
2529 error ("array subscript is not an integer");
2530 return error_mark_node;
2533 warn_array_subscript_with_type_char (idx);
2535 return build_indirect_ref (cp_build_binary_op (PLUS_EXPR, ar, ind),
2540 /* Resolve a pointer to member function. INSTANCE is the object
2541 instance to use, if the member points to a virtual member.
2543 This used to avoid checking for virtual functions if basetype
2544 has no virtual functions, according to an earlier ANSI draft.
2545 With the final ISO C++ rules, such an optimization is
2546 incorrect: A pointer to a derived member can be static_cast
2547 to pointer-to-base-member, as long as the dynamic object
2548 later has the right member. */
2551 get_member_function_from_ptrfunc (tree *instance_ptrptr, tree function)
2553 if (TREE_CODE (function) == OFFSET_REF)
2554 function = TREE_OPERAND (function, 1);
2556 if (TYPE_PTRMEMFUNC_P (TREE_TYPE (function)))
2558 tree idx, delta, e1, e2, e3, vtbl, basetype;
2559 tree fntype = TYPE_PTRMEMFUNC_FN_TYPE (TREE_TYPE (function));
2561 tree instance_ptr = *instance_ptrptr;
2562 tree instance_save_expr = 0;
2563 if (instance_ptr == error_mark_node)
2565 if (TREE_CODE (function) == PTRMEM_CST)
2567 /* Extracting the function address from a pmf is only
2568 allowed with -Wno-pmf-conversions. It only works for
2570 e1 = build_addr_func (PTRMEM_CST_MEMBER (function));
2571 e1 = convert (fntype, e1);
2576 error ("object missing in use of %qE", function);
2577 return error_mark_node;
2581 if (TREE_SIDE_EFFECTS (instance_ptr))
2582 instance_ptr = instance_save_expr = save_expr (instance_ptr);
2584 if (TREE_SIDE_EFFECTS (function))
2585 function = save_expr (function);
2587 /* Start by extracting all the information from the PMF itself. */
2588 e3 = pfn_from_ptrmemfunc (function);
2589 delta = build_ptrmemfunc_access_expr (function, delta_identifier);
2590 idx = build1 (NOP_EXPR, vtable_index_type, e3);
2591 switch (TARGET_PTRMEMFUNC_VBIT_LOCATION)
2593 case ptrmemfunc_vbit_in_pfn:
2594 e1 = cp_build_binary_op (BIT_AND_EXPR, idx, integer_one_node);
2595 idx = cp_build_binary_op (MINUS_EXPR, idx, integer_one_node);
2598 case ptrmemfunc_vbit_in_delta:
2599 e1 = cp_build_binary_op (BIT_AND_EXPR, delta, integer_one_node);
2600 delta = cp_build_binary_op (RSHIFT_EXPR, delta, integer_one_node);
2607 /* Convert down to the right base before using the instance. A
2608 special case is that in a pointer to member of class C, C may
2609 be incomplete. In that case, the function will of course be
2610 a member of C, and no conversion is required. In fact,
2611 lookup_base will fail in that case, because incomplete
2612 classes do not have BINFOs. */
2613 basetype = TYPE_METHOD_BASETYPE (TREE_TYPE (fntype));
2614 if (!same_type_ignoring_top_level_qualifiers_p
2615 (basetype, TREE_TYPE (TREE_TYPE (instance_ptr))))
2617 basetype = lookup_base (TREE_TYPE (TREE_TYPE (instance_ptr)),
2618 basetype, ba_check, NULL);
2619 instance_ptr = build_base_path (PLUS_EXPR, instance_ptr, basetype,
2621 if (instance_ptr == error_mark_node)
2622 return error_mark_node;
2624 /* ...and then the delta in the PMF. */
2625 instance_ptr = build2 (POINTER_PLUS_EXPR, TREE_TYPE (instance_ptr),
2626 instance_ptr, fold_convert (sizetype, delta));
2628 /* Hand back the adjusted 'this' argument to our caller. */
2629 *instance_ptrptr = instance_ptr;
2631 /* Next extract the vtable pointer from the object. */
2632 vtbl = build1 (NOP_EXPR, build_pointer_type (vtbl_ptr_type_node),
2634 vtbl = build_indirect_ref (vtbl, NULL);
2636 /* Finally, extract the function pointer from the vtable. */
2637 e2 = fold_build2 (POINTER_PLUS_EXPR, TREE_TYPE (vtbl), vtbl,
2638 fold_convert (sizetype, 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. Because
2896 we hold default arguments in the FUNCTION_TYPE (which is so
2897 wrong), we can see default parameters here from deduced
2898 contexts (and via typeof) for indirect function calls.
2899 Fortunately we know whether we have a function decl to
2900 provide default arguments in a language conformant
2902 if (fndecl && TREE_PURPOSE (typetail)
2903 && TREE_CODE (TREE_PURPOSE (typetail)) != DEFAULT_ARG)
2905 for (; typetail != void_list_node; ++i)
2908 = convert_default_arg (TREE_VALUE (typetail),
2909 TREE_PURPOSE (typetail),
2912 if (parmval == error_mark_node)
2915 argarray[i] = parmval;
2916 typetail = TREE_CHAIN (typetail);
2917 /* ends with `...'. */
2918 if (typetail == NULL_TREE)
2926 error ("too few arguments to %s %q+#D", called_thing, fndecl);
2927 error ("at this point in file");
2930 error ("too few arguments to function");
2935 gcc_assert (i <= nargs);
2939 /* Build a binary-operation expression, after performing default
2940 conversions on the operands. CODE is the kind of expression to
2941 build. ARG1 and ARG2 are the arguments. ARG1_CODE and ARG2_CODE
2942 are the tree codes which correspond to ARG1 and ARG2 when issuing
2943 warnings about possibly misplaced parentheses. They may differ
2944 from the TREE_CODE of ARG1 and ARG2 if the parser has done constant
2945 folding (e.g., if the parser sees "a | 1 + 1", it may call this
2946 routine with ARG2 being an INTEGER_CST and ARG2_CODE == PLUS_EXPR).
2947 To avoid issuing any parentheses warnings, pass ARG1_CODE and/or
2948 ARG2_CODE as ERROR_MARK. */
2951 build_x_binary_op (enum tree_code code, tree arg1, enum tree_code arg1_code,
2952 tree arg2, enum tree_code arg2_code, bool *overloaded_p)
2961 if (processing_template_decl)
2963 if (type_dependent_expression_p (arg1)
2964 || type_dependent_expression_p (arg2))
2965 return build_min_nt (code, arg1, arg2);
2966 arg1 = build_non_dependent_expr (arg1);
2967 arg2 = build_non_dependent_expr (arg2);
2970 if (code == DOTSTAR_EXPR)
2971 expr = build_m_component_ref (arg1, arg2);
2973 expr = build_new_op (code, LOOKUP_NORMAL, arg1, arg2, NULL_TREE,
2976 /* Check for cases such as x+y<<z which users are likely to
2977 misinterpret. But don't warn about obj << x + y, since that is a
2978 common idiom for I/O. */
2979 if (warn_parentheses
2980 && !processing_template_decl
2981 && !error_operand_p (arg1)
2982 && !error_operand_p (arg2)
2983 && (code != LSHIFT_EXPR
2984 || !CLASS_TYPE_P (TREE_TYPE (arg1))))
2985 warn_about_parentheses (code, arg1_code, arg2_code);
2987 if (processing_template_decl && expr != error_mark_node)
2988 return build_min_non_dep (code, expr, orig_arg1, orig_arg2);
2993 /* Build a binary-operation expression without default conversions.
2994 CODE is the kind of expression to build.
2995 This function differs from `build' in several ways:
2996 the data type of the result is computed and recorded in it,
2997 warnings are generated if arg data types are invalid,
2998 special handling for addition and subtraction of pointers is known,
2999 and some optimization is done (operations on narrow ints
3000 are done in the narrower type when that gives the same result).
3001 Constant folding is also done before the result is returned.
3003 Note that the operands will never have enumeral types
3004 because either they have just had the default conversions performed
3005 or they have both just been converted to some other type in which
3006 the arithmetic is to be done.
3008 C++: must do special pointer arithmetic when implementing
3009 multiple inheritance, and deal with pointer to member functions. */
3012 build_binary_op (enum tree_code code, tree orig_op0, tree orig_op1,
3013 int convert_p ATTRIBUTE_UNUSED)
3016 enum tree_code code0, code1;
3018 const char *invalid_op_diag;
3020 /* Expression code to give to the expression when it is built.
3021 Normally this is CODE, which is what the caller asked for,
3022 but in some special cases we change it. */
3023 enum tree_code resultcode = code;
3025 /* Data type in which the computation is to be performed.
3026 In the simplest cases this is the common type of the arguments. */
3027 tree result_type = NULL;
3029 /* Nonzero means operands have already been type-converted
3030 in whatever way is necessary.
3031 Zero means they need to be converted to RESULT_TYPE. */
3034 /* Nonzero means create the expression with this type, rather than
3036 tree build_type = 0;
3038 /* Nonzero means after finally constructing the expression
3039 convert it to this type. */
3040 tree final_type = 0;
3044 /* Nonzero if this is an operation like MIN or MAX which can
3045 safely be computed in short if both args are promoted shorts.
3046 Also implies COMMON.
3047 -1 indicates a bitwise operation; this makes a difference
3048 in the exact conditions for when it is safe to do the operation
3049 in a narrower mode. */
3052 /* Nonzero if this is a comparison operation;
3053 if both args are promoted shorts, compare the original shorts.
3054 Also implies COMMON. */
3055 int short_compare = 0;
3057 /* Nonzero if this is a right-shift operation, which can be computed on the
3058 original short and then promoted if the operand is a promoted short. */
3059 int short_shift = 0;
3061 /* Nonzero means set RESULT_TYPE to the common type of the args. */
3064 /* True if both operands have arithmetic type. */
3065 bool arithmetic_types_p;
3067 /* Apply default conversions. */
3071 if (code == TRUTH_AND_EXPR || code == TRUTH_ANDIF_EXPR
3072 || code == TRUTH_OR_EXPR || code == TRUTH_ORIF_EXPR
3073 || code == TRUTH_XOR_EXPR)
3075 if (!really_overloaded_fn (op0))
3076 op0 = decay_conversion (op0);
3077 if (!really_overloaded_fn (op1))
3078 op1 = decay_conversion (op1);
3082 if (!really_overloaded_fn (op0))
3083 op0 = default_conversion (op0);
3084 if (!really_overloaded_fn (op1))
3085 op1 = default_conversion (op1);
3088 /* Strip NON_LVALUE_EXPRs, etc., since we aren't using as an lvalue. */
3089 STRIP_TYPE_NOPS (op0);
3090 STRIP_TYPE_NOPS (op1);
3092 /* DTRT if one side is an overloaded function, but complain about it. */
3093 if (type_unknown_p (op0))
3095 tree t = instantiate_type (TREE_TYPE (op1), op0, tf_none);
3096 if (t != error_mark_node)
3098 pedwarn ("assuming cast to type %qT from overloaded function",
3103 if (type_unknown_p (op1))
3105 tree t = instantiate_type (TREE_TYPE (op0), op1, tf_none);
3106 if (t != error_mark_node)
3108 pedwarn ("assuming cast to type %qT from overloaded function",
3114 type0 = TREE_TYPE (op0);
3115 type1 = TREE_TYPE (op1);
3117 /* The expression codes of the data types of the arguments tell us
3118 whether the arguments are integers, floating, pointers, etc. */
3119 code0 = TREE_CODE (type0);
3120 code1 = TREE_CODE (type1);
3122 /* If an error was already reported for one of the arguments,
3123 avoid reporting another error. */
3125 if (code0 == ERROR_MARK || code1 == ERROR_MARK)
3126 return error_mark_node;
3128 if ((invalid_op_diag
3129 = targetm.invalid_binary_op (code, type0, type1)))
3131 error (invalid_op_diag);
3132 return error_mark_node;
3138 /* Subtraction of two similar pointers.
3139 We must subtract them as integers, then divide by object size. */
3140 if (code0 == POINTER_TYPE && code1 == POINTER_TYPE
3141 && same_type_ignoring_top_level_qualifiers_p (TREE_TYPE (type0),
3143 return pointer_diff (op0, op1, common_type (type0, type1));
3144 /* In all other cases except pointer - int, the usual arithmetic
3146 else if (!(code0 == POINTER_TYPE && code1 == INTEGER_TYPE))
3151 /* The pointer - int case is just like pointer + int; fall
3154 if ((code0 == POINTER_TYPE || code1 == POINTER_TYPE)
3155 && (code0 == INTEGER_TYPE || code1 == INTEGER_TYPE))
3159 ptr_operand = ((code0 == POINTER_TYPE) ? op0 : op1);
3160 int_operand = ((code0 == INTEGER_TYPE) ? op0 : op1);
3161 if (processing_template_decl)
3163 result_type = TREE_TYPE (ptr_operand);
3166 return cp_pointer_int_sum (code,
3177 case TRUNC_DIV_EXPR:
3179 case FLOOR_DIV_EXPR:
3180 case ROUND_DIV_EXPR:
3181 case EXACT_DIV_EXPR:
3182 if ((code0 == INTEGER_TYPE || code0 == REAL_TYPE
3183 || code0 == COMPLEX_TYPE || code0 == VECTOR_TYPE)
3184 && (code1 == INTEGER_TYPE || code1 == REAL_TYPE
3185 || code1 == COMPLEX_TYPE || code1 == VECTOR_TYPE))
3187 enum tree_code tcode0 = code0, tcode1 = code1;
3189 warn_for_div_by_zero (op1);
3191 if (tcode0 == COMPLEX_TYPE || tcode0 == VECTOR_TYPE)
3192 tcode0 = TREE_CODE (TREE_TYPE (TREE_TYPE (op0)));
3193 if (tcode1 == COMPLEX_TYPE || tcode1 == VECTOR_TYPE)
3194 tcode1 = TREE_CODE (TREE_TYPE (TREE_TYPE (op1)));
3196 if (!(tcode0 == INTEGER_TYPE && tcode1 == INTEGER_TYPE))
3197 resultcode = RDIV_EXPR;
3199 /* When dividing two signed integers, we have to promote to int.
3200 unless we divide by a constant != -1. Note that default
3201 conversion will have been performed on the operands at this
3202 point, so we have to dig out the original type to find out if
3204 shorten = ((TREE_CODE (op0) == NOP_EXPR
3205 && TYPE_UNSIGNED (TREE_TYPE (TREE_OPERAND (op0, 0))))
3206 || (TREE_CODE (op1) == INTEGER_CST
3207 && ! integer_all_onesp (op1)));
3216 if ((code0 == INTEGER_TYPE && code1 == INTEGER_TYPE)
3217 || (code0 == VECTOR_TYPE && code1 == VECTOR_TYPE
3218 && !VECTOR_FLOAT_TYPE_P (type0)
3219 && !VECTOR_FLOAT_TYPE_P (type1)))
3223 case TRUNC_MOD_EXPR:
3224 case FLOOR_MOD_EXPR:
3225 warn_for_div_by_zero (op1);
3227 if (code0 == INTEGER_TYPE && code1 == INTEGER_TYPE)
3229 /* Although it would be tempting to shorten always here, that loses
3230 on some targets, since the modulo instruction is undefined if the
3231 quotient can't be represented in the computation mode. We shorten
3232 only if unsigned or if dividing by something we know != -1. */
3233 shorten = ((TREE_CODE (op0) == NOP_EXPR
3234 && TYPE_UNSIGNED (TREE_TYPE (TREE_OPERAND (op0, 0))))
3235 || (TREE_CODE (op1) == INTEGER_CST
3236 && ! integer_all_onesp (op1)));
3241 case TRUTH_ANDIF_EXPR:
3242 case TRUTH_ORIF_EXPR:
3243 case TRUTH_AND_EXPR:
3245 result_type = boolean_type_node;
3248 /* Shift operations: result has same type as first operand;
3249 always convert second operand to int.
3250 Also set SHORT_SHIFT if shifting rightward. */
3253 if (code0 == INTEGER_TYPE && code1 == INTEGER_TYPE)
3255 result_type = type0;
3256 if (TREE_CODE (op1) == INTEGER_CST)
3258 if (tree_int_cst_lt (op1, integer_zero_node))
3259 warning (0, "right shift count is negative");
3262 if (! integer_zerop (op1))
3264 if (compare_tree_int (op1, TYPE_PRECISION (type0)) >= 0)
3265 warning (0, "right shift count >= width of type");
3268 /* Convert the shift-count to an integer, regardless of
3269 size of value being shifted. */
3270 if (TYPE_MAIN_VARIANT (TREE_TYPE (op1)) != integer_type_node)
3271 op1 = cp_convert (integer_type_node, op1);
3272 /* Avoid converting op1 to result_type later. */
3278 if (code0 == INTEGER_TYPE && code1 == INTEGER_TYPE)
3280 result_type = type0;
3281 if (TREE_CODE (op1) == INTEGER_CST)
3283 if (tree_int_cst_lt (op1, integer_zero_node))
3284 warning (0, "left shift count is negative");
3285 else if (compare_tree_int (op1, TYPE_PRECISION (type0)) >= 0)
3286 warning (0, "left shift count >= width of type");
3288 /* Convert the shift-count to an integer, regardless of
3289 size of value being shifted. */
3290 if (TYPE_MAIN_VARIANT (TREE_TYPE (op1)) != integer_type_node)
3291 op1 = cp_convert (integer_type_node, op1);
3292 /* Avoid converting op1 to result_type later. */
3299 if (code0 == INTEGER_TYPE && code1 == INTEGER_TYPE)
3301 result_type = type0;
3302 if (TREE_CODE (op1) == INTEGER_CST)
3304 if (tree_int_cst_lt (op1, integer_zero_node))
3305 warning (0, (code == LROTATE_EXPR)
3306 ? G_("left rotate count is negative")
3307 : G_("right rotate count is negative"));
3308 else if (compare_tree_int (op1, TYPE_PRECISION (type0)) >= 0)
3309 warning (0, (code == LROTATE_EXPR)
3310 ? G_("left rotate count >= width of type")
3311 : G_("right rotate count >= width of type"));
3313 /* Convert the shift-count to an integer, regardless of
3314 size of value being shifted. */
3315 if (TYPE_MAIN_VARIANT (TREE_TYPE (op1)) != integer_type_node)
3316 op1 = cp_convert (integer_type_node, op1);
3322 if (code0 == REAL_TYPE || code1 == REAL_TYPE)
3323 warning (OPT_Wfloat_equal,
3324 "comparing floating point with == or != is unsafe");
3325 if ((TREE_CODE (orig_op0) == STRING_CST && !integer_zerop (op1))
3326 || (TREE_CODE (orig_op1) == STRING_CST && !integer_zerop (op0)))
3327 warning (OPT_Waddress, "comparison with string literal results in unspecified behaviour");
3329 build_type = boolean_type_node;
3330 if ((code0 == INTEGER_TYPE || code0 == REAL_TYPE
3331 || code0 == COMPLEX_TYPE)
3332 && (code1 == INTEGER_TYPE || code1 == REAL_TYPE
3333 || code1 == COMPLEX_TYPE))
3335 else if ((code0 == POINTER_TYPE && code1 == POINTER_TYPE)
3336 || (TYPE_PTRMEM_P (type0) && TYPE_PTRMEM_P (type1)))
3337 result_type = composite_pointer_type (type0, type1, op0, op1,
3339 else if ((code0 == POINTER_TYPE || TYPE_PTRMEM_P (type0))
3340 && null_ptr_cst_p (op1))
3342 if (TREE_CODE (op0) == ADDR_EXPR
3343 && decl_with_nonnull_addr_p (TREE_OPERAND (op0, 0)))
3344 warning (OPT_Waddress, "the address of %qD will never be NULL",
3345 TREE_OPERAND (op0, 0));
3346 result_type = type0;
3348 else if ((code1 == POINTER_TYPE || TYPE_PTRMEM_P (type1))
3349 && null_ptr_cst_p (op0))
3351 if (TREE_CODE (op1) == ADDR_EXPR
3352 && decl_with_nonnull_addr_p (TREE_OPERAND (op1, 0)))
3353 warning (OPT_Waddress, "the address of %qD will never be NULL",
3354 TREE_OPERAND (op1, 0));
3355 result_type = type1;
3357 else if (code0 == POINTER_TYPE && code1 == INTEGER_TYPE)
3359 result_type = type0;
3360 error ("ISO C++ forbids comparison between pointer and integer");
3362 else if (code0 == INTEGER_TYPE && code1 == POINTER_TYPE)
3364 result_type = type1;
3365 error ("ISO C++ forbids comparison between pointer and integer");
3367 else if (TYPE_PTRMEMFUNC_P (type0) && null_ptr_cst_p (op1))
3369 if (TARGET_PTRMEMFUNC_VBIT_LOCATION
3370 == ptrmemfunc_vbit_in_delta)
3372 tree pfn0 = pfn_from_ptrmemfunc (op0);
3373 tree delta0 = build_ptrmemfunc_access_expr (op0,
3375 tree e1 = cp_build_binary_op (EQ_EXPR,
3377 fold_convert (TREE_TYPE (pfn0),
3378 integer_zero_node));
3379 tree e2 = cp_build_binary_op (BIT_AND_EXPR,
3382 e2 = cp_build_binary_op (EQ_EXPR, e2, integer_zero_node);
3383 op0 = cp_build_binary_op (TRUTH_ANDIF_EXPR, e1, e2);
3384 op1 = cp_convert (TREE_TYPE (op0), integer_one_node);
3388 op0 = build_ptrmemfunc_access_expr (op0, pfn_identifier);
3389 op1 = cp_convert (TREE_TYPE (op0), integer_zero_node);
3391 result_type = TREE_TYPE (op0);
3393 else if (TYPE_PTRMEMFUNC_P (type1) && null_ptr_cst_p (op0))
3394 return cp_build_binary_op (code, op1, op0);
3395 else if (TYPE_PTRMEMFUNC_P (type0) && TYPE_PTRMEMFUNC_P (type1)
3396 && same_type_p (type0, type1))
3398 /* E will be the final comparison. */
3400 /* E1 and E2 are for scratch. */
3408 if (TREE_SIDE_EFFECTS (op0))
3409 op0 = save_expr (op0);
3410 if (TREE_SIDE_EFFECTS (op1))
3411 op1 = save_expr (op1);
3413 pfn0 = pfn_from_ptrmemfunc (op0);
3414 pfn1 = pfn_from_ptrmemfunc (op1);
3415 delta0 = build_ptrmemfunc_access_expr (op0,
3417 delta1 = build_ptrmemfunc_access_expr (op1,
3419 if (TARGET_PTRMEMFUNC_VBIT_LOCATION
3420 == ptrmemfunc_vbit_in_delta)
3425 && ((op0.delta == op1.delta)
3426 || (!op0.pfn && op0.delta & 1 == 0
3427 && op1.delta & 1 == 0))
3429 The reason for the `!op0.pfn' bit is that a NULL
3430 pointer-to-member is any member with a zero PFN and
3431 LSB of the DELTA field is 0. */
3433 e1 = cp_build_binary_op (BIT_AND_EXPR,
3436 e1 = cp_build_binary_op (EQ_EXPR, e1, integer_zero_node);
3437 e2 = cp_build_binary_op (BIT_AND_EXPR,
3440 e2 = cp_build_binary_op (EQ_EXPR, e2, integer_zero_node);
3441 e1 = cp_build_binary_op (TRUTH_ANDIF_EXPR, e2, e1);
3442 e2 = cp_build_binary_op (EQ_EXPR,
3444 fold_convert (TREE_TYPE (pfn0),
3445 integer_zero_node));
3446 e2 = cp_build_binary_op (TRUTH_ANDIF_EXPR, e2, e1);
3447 e1 = cp_build_binary_op (EQ_EXPR, delta0, delta1);
3448 e1 = cp_build_binary_op (TRUTH_ORIF_EXPR, e1, e2);
3455 && (!op0.pfn || op0.delta == op1.delta))
3457 The reason for the `!op0.pfn' bit is that a NULL
3458 pointer-to-member is any member with a zero PFN; the
3459 DELTA field is unspecified. */
3461 e1 = cp_build_binary_op (EQ_EXPR, delta0, delta1);
3462 e2 = cp_build_binary_op (EQ_EXPR,
3464 fold_convert (TREE_TYPE (pfn0),
3465 integer_zero_node));
3466 e1 = cp_build_binary_op (TRUTH_ORIF_EXPR, e1, e2);
3468 e2 = build2 (EQ_EXPR, boolean_type_node, pfn0, pfn1);
3469 e = cp_build_binary_op (TRUTH_ANDIF_EXPR, e2, e1);
3470 if (code == EQ_EXPR)
3472 return cp_build_binary_op (EQ_EXPR, e, integer_zero_node);
3476 gcc_assert (!TYPE_PTRMEMFUNC_P (type0)
3477 || !same_type_p (TYPE_PTRMEMFUNC_FN_TYPE (type0),
3479 gcc_assert (!TYPE_PTRMEMFUNC_P (type1)
3480 || !same_type_p (TYPE_PTRMEMFUNC_FN_TYPE (type1),
3488 if ((code0 == INTEGER_TYPE || code0 == REAL_TYPE)
3489 && (code1 == INTEGER_TYPE || code1 == REAL_TYPE))
3491 else if (code0 == POINTER_TYPE && code1 == POINTER_TYPE)
3492 result_type = composite_pointer_type (type0, type1, op0, op1,
3500 if (TREE_CODE (orig_op0) == STRING_CST
3501 || TREE_CODE (orig_op1) == STRING_CST)
3502 warning (OPT_Waddress, "comparison with string literal results in unspecified behaviour");
3504 build_type = boolean_type_node;
3505 if ((code0 == INTEGER_TYPE || code0 == REAL_TYPE)
3506 && (code1 == INTEGER_TYPE || code1 == REAL_TYPE))
3508 else if (code0 == POINTER_TYPE && code1 == POINTER_TYPE)
3509 result_type = composite_pointer_type (type0, type1, op0, op1,
3511 else if (code0 == POINTER_TYPE && TREE_CODE (op1) == INTEGER_CST
3512 && integer_zerop (op1))
3513 result_type = type0;
3514 else if (code1 == POINTER_TYPE && TREE_CODE (op0) == INTEGER_CST
3515 && integer_zerop (op0))
3516 result_type = type1;
3517 else if (code0 == POINTER_TYPE && code1 == INTEGER_TYPE)
3519 result_type = type0;
3520 pedwarn ("ISO C++ forbids comparison between pointer and integer");
3522 else if (code0 == INTEGER_TYPE && code1 == POINTER_TYPE)
3524 result_type = type1;
3525 pedwarn ("ISO C++ forbids comparison between pointer and integer");
3529 case UNORDERED_EXPR:
3536 build_type = integer_type_node;
3537 if (code0 != REAL_TYPE || code1 != REAL_TYPE)
3539 error ("unordered comparison on non-floating point argument");
3540 return error_mark_node;
3549 if (((code0 == INTEGER_TYPE || code0 == REAL_TYPE || code0 == COMPLEX_TYPE)
3550 && (code1 == INTEGER_TYPE || code1 == REAL_TYPE
3551 || code1 == COMPLEX_TYPE)))
3552 arithmetic_types_p = 1;
3555 arithmetic_types_p = 0;
3556 /* Vector arithmetic is only allowed when both sides are vectors. */
3557 if (code0 == VECTOR_TYPE && code1 == VECTOR_TYPE)
3559 if (!tree_int_cst_equal (TYPE_SIZE (type0), TYPE_SIZE (type1))
3560 || !same_scalar_type_ignoring_signedness (TREE_TYPE (type0),
3563 binary_op_error (code, type0, type1);
3564 return error_mark_node;
3566 arithmetic_types_p = 1;
3569 /* Determine the RESULT_TYPE, if it is not already known. */
3571 && arithmetic_types_p
3572 && (shorten || common || short_compare))
3573 result_type = common_type (type0, type1);
3577 error ("invalid operands of types %qT and %qT to binary %qO",
3578 TREE_TYPE (orig_op0), TREE_TYPE (orig_op1), code);
3579 return error_mark_node;
3582 /* If we're in a template, the only thing we need to know is the
3584 if (processing_template_decl)
3586 /* Since the middle-end checks the type when doing a build2, we
3587 need to build the tree in pieces. This built tree will never
3588 get out of the front-end as we replace it when instantiating
3590 tree tmp = build2 (resultcode,
3591 build_type ? build_type : result_type,
3593 TREE_OPERAND (tmp, 0) = op0;
3597 if (arithmetic_types_p)
3599 int none_complex = (code0 != COMPLEX_TYPE && code1 != COMPLEX_TYPE);
3601 /* For certain operations (which identify themselves by shorten != 0)
3602 if both args were extended from the same smaller type,
3603 do the arithmetic in that type and then extend.
3605 shorten !=0 and !=1 indicates a bitwise operation.
3606 For them, this optimization is safe only if
3607 both args are zero-extended or both are sign-extended.
3608 Otherwise, we might change the result.
3609 Eg, (short)-1 | (unsigned short)-1 is (int)-1
3610 but calculated in (unsigned short) it would be (unsigned short)-1. */
3612 if (shorten && none_complex)
3614 int unsigned0, unsigned1;
3615 tree arg0 = get_narrower (op0, &unsigned0);
3616 tree arg1 = get_narrower (op1, &unsigned1);
3617 /* UNS is 1 if the operation to be done is an unsigned one. */
3618 int uns = TYPE_UNSIGNED (result_type);
3621 final_type = result_type;
3623 /* Handle the case that OP0 does not *contain* a conversion
3624 but it *requires* conversion to FINAL_TYPE. */
3626 if (op0 == arg0 && TREE_TYPE (op0) != final_type)
3627 unsigned0 = TYPE_UNSIGNED (TREE_TYPE (op0));
3628 if (op1 == arg1 && TREE_TYPE (op1) != final_type)
3629 unsigned1 = TYPE_UNSIGNED (TREE_TYPE (op1));
3631 /* Now UNSIGNED0 is 1 if ARG0 zero-extends to FINAL_TYPE. */
3633 /* For bitwise operations, signedness of nominal type
3634 does not matter. Consider only how operands were extended. */
3638 /* Note that in all three cases below we refrain from optimizing
3639 an unsigned operation on sign-extended args.
3640 That would not be valid. */
3642 /* Both args variable: if both extended in same way
3643 from same width, do it in that width.
3644 Do it unsigned if args were zero-extended. */
3645 if ((TYPE_PRECISION (TREE_TYPE (arg0))
3646 < TYPE_PRECISION (result_type))
3647 && (TYPE_PRECISION (TREE_TYPE (arg1))
3648 == TYPE_PRECISION (TREE_TYPE (arg0)))
3649 && unsigned0 == unsigned1
3650 && (unsigned0 || !uns))
3651 result_type = c_common_signed_or_unsigned_type
3652 (unsigned0, common_type (TREE_TYPE (arg0), TREE_TYPE (arg1)));
3653 else if (TREE_CODE (arg0) == INTEGER_CST
3654 && (unsigned1 || !uns)
3655 && (TYPE_PRECISION (TREE_TYPE (arg1))
3656 < TYPE_PRECISION (result_type))
3657 && (type = c_common_signed_or_unsigned_type
3658 (unsigned1, TREE_TYPE (arg1)),
3659 int_fits_type_p (arg0, type)))
3661 else if (TREE_CODE (arg1) == INTEGER_CST
3662 && (unsigned0 || !uns)
3663 && (TYPE_PRECISION (TREE_TYPE (arg0))
3664 < TYPE_PRECISION (result_type))
3665 && (type = c_common_signed_or_unsigned_type
3666 (unsigned0, TREE_TYPE (arg0)),
3667 int_fits_type_p (arg1, type)))
3671 /* Shifts can be shortened if shifting right. */
3676 tree arg0 = get_narrower (op0, &unsigned_arg);
3678 final_type = result_type;
3680 if (arg0 == op0 && final_type == TREE_TYPE (op0))
3681 unsigned_arg = TYPE_UNSIGNED (TREE_TYPE (op0));
3683 if (TYPE_PRECISION (TREE_TYPE (arg0)) < TYPE_PRECISION (result_type)
3684 /* We can shorten only if the shift count is less than the
3685 number of bits in the smaller type size. */
3686 && compare_tree_int (op1, TYPE_PRECISION (TREE_TYPE (arg0))) < 0
3687 /* If arg is sign-extended and then unsigned-shifted,
3688 we can simulate this with a signed shift in arg's type
3689 only if the extended result is at least twice as wide
3690 as the arg. Otherwise, the shift could use up all the
3691 ones made by sign-extension and bring in zeros.
3692 We can't optimize that case at all, but in most machines
3693 it never happens because available widths are 2**N. */
3694 && (!TYPE_UNSIGNED (final_type)
3696 || (((unsigned) 2 * TYPE_PRECISION (TREE_TYPE (arg0)))
3697 <= TYPE_PRECISION (result_type))))
3699 /* Do an unsigned shift if the operand was zero-extended. */
3701 = c_common_signed_or_unsigned_type (unsigned_arg,
3703 /* Convert value-to-be-shifted to that type. */
3704 if (TREE_TYPE (op0) != result_type)
3705 op0 = cp_convert (result_type, op0);
3710 /* Comparison operations are shortened too but differently.
3711 They identify themselves by setting short_compare = 1. */
3715 /* Don't write &op0, etc., because that would prevent op0
3716 from being kept in a register.
3717 Instead, make copies of the our local variables and
3718 pass the copies by reference, then copy them back afterward. */
3719 tree xop0 = op0, xop1 = op1, xresult_type = result_type;
3720 enum tree_code xresultcode = resultcode;
3722 = shorten_compare (&xop0, &xop1, &xresult_type, &xresultcode);
3724 return cp_convert (boolean_type_node, val);
3725 op0 = xop0, op1 = xop1;
3727 resultcode = xresultcode;
3730 if ((short_compare || code == MIN_EXPR || code == MAX_EXPR)
3731 && warn_sign_compare
3732 /* Do not warn until the template is instantiated; we cannot
3733 bound the ranges of the arguments until that point. */
3734 && !processing_template_decl)
3736 int op0_signed = !TYPE_UNSIGNED (TREE_TYPE (orig_op0));
3737 int op1_signed = !TYPE_UNSIGNED (TREE_TYPE (orig_op1));
3739 int unsignedp0, unsignedp1;
3740 tree primop0 = get_narrower (op0, &unsignedp0);
3741 tree primop1 = get_narrower (op1, &unsignedp1);
3743 /* Check for comparison of different enum types. */
3744 if (TREE_CODE (TREE_TYPE (orig_op0)) == ENUMERAL_TYPE
3745 && TREE_CODE (TREE_TYPE (orig_op1)) == ENUMERAL_TYPE
3746 && TYPE_MAIN_VARIANT (TREE_TYPE (orig_op0))
3747 != TYPE_MAIN_VARIANT (TREE_TYPE (orig_op1)))
3749 warning (0, "comparison between types %q#T and %q#T",
3750 TREE_TYPE (orig_op0), TREE_TYPE (orig_op1));
3753 /* Give warnings for comparisons between signed and unsigned
3754 quantities that may fail. */
3755 /* Do the checking based on the original operand trees, so that
3756 casts will be considered, but default promotions won't be. */
3758 /* Do not warn if the comparison is being done in a signed type,
3759 since the signed type will only be chosen if it can represent
3760 all the values of the unsigned type. */
3761 if (!TYPE_UNSIGNED (result_type))
3763 /* Do not warn if both operands are unsigned. */
3764 else if (op0_signed == op1_signed)
3766 /* Do not warn if the signed quantity is an unsuffixed
3767 integer literal (or some static constant expression
3768 involving such literals or a conditional expression
3769 involving such literals) and it is non-negative. */
3770 else if ((op0_signed && tree_expr_nonnegative_p (orig_op0))
3771 || (op1_signed && tree_expr_nonnegative_p (orig_op1)))
3773 /* Do not warn if the comparison is an equality operation,
3774 the unsigned quantity is an integral constant and it does
3775 not use the most significant bit of result_type. */
3776 else if ((resultcode == EQ_EXPR || resultcode == NE_EXPR)
3777 && ((op0_signed && TREE_CODE (orig_op1) == INTEGER_CST
3778 && int_fits_type_p (orig_op1, c_common_signed_type
3780 || (op1_signed && TREE_CODE (orig_op0) == INTEGER_CST
3781 && int_fits_type_p (orig_op0, c_common_signed_type
3785 warning (0, "comparison between signed and unsigned integer expressions");
3787 /* Warn if two unsigned values are being compared in a size
3788 larger than their original size, and one (and only one) is the
3789 result of a `~' operator. This comparison will always fail.
3791 Also warn if one operand is a constant, and the constant does not
3792 have all bits set that are set in the ~ operand when it is
3795 if ((TREE_CODE (primop0) == BIT_NOT_EXPR)
3796 ^ (TREE_CODE (primop1) == BIT_NOT_EXPR))
3798 if (TREE_CODE (primop0) == BIT_NOT_EXPR)
3799 primop0 = get_narrower (TREE_OPERAND (op0, 0), &unsignedp0);
3800 if (TREE_CODE (primop1) == BIT_NOT_EXPR)
3801 primop1 = get_narrower (TREE_OPERAND (op1, 0), &unsignedp1);
3803 if (host_integerp (primop0, 0) || host_integerp (primop1, 0))
3806 HOST_WIDE_INT constant, mask;
3810 if (host_integerp (primop0, 0))
3813 unsignedp = unsignedp1;
3814 constant = tree_low_cst (primop0, 0);
3819 unsignedp = unsignedp0;
3820 constant = tree_low_cst (primop1, 0);
3823 bits = TYPE_PRECISION (TREE_TYPE (primop));
3824 if (bits < TYPE_PRECISION (result_type)
3825 && bits < HOST_BITS_PER_LONG && unsignedp)
3827 mask = (~ (HOST_WIDE_INT) 0) << bits;
3828 if ((mask & constant) != mask)
3829 warning (0, "comparison of promoted ~unsigned with constant");
3832 else if (unsignedp0 && unsignedp1
3833 && (TYPE_PRECISION (TREE_TYPE (primop0))
3834 < TYPE_PRECISION (result_type))
3835 && (TYPE_PRECISION (TREE_TYPE (primop1))
3836 < TYPE_PRECISION (result_type)))
3837 warning (0, "comparison of promoted ~unsigned with unsigned");
3842 /* Issue warnings about peculiar, but valid, uses of NULL. */
3843 if ((orig_op0 == null_node || orig_op1 == null_node)
3844 /* It's reasonable to use pointer values as operands of &&
3845 and ||, so NULL is no exception. */
3846 && code != TRUTH_ANDIF_EXPR && code != TRUTH_ORIF_EXPR
3847 && ( /* Both are NULL (or 0) and the operation was not a comparison. */
3848 (null_ptr_cst_p (orig_op0) && null_ptr_cst_p (orig_op1)
3849 && code != EQ_EXPR && code != NE_EXPR)
3850 /* Or if one of OP0 or OP1 is neither a pointer nor NULL. */
3851 || (!null_ptr_cst_p (orig_op0) && TREE_CODE (TREE_TYPE (op0)) != POINTER_TYPE)
3852 || (!null_ptr_cst_p (orig_op1) && TREE_CODE (TREE_TYPE (op1)) != POINTER_TYPE)))
3853 /* Some sort of arithmetic operation involving NULL was
3854 performed. Note that pointer-difference and pointer-addition
3855 have already been handled above, and so we don't end up here in
3857 warning (OPT_Wpointer_arith, "NULL used in arithmetic");
3860 /* If CONVERTED is zero, both args will be converted to type RESULT_TYPE.
3861 Then the expression will be built.
3862 It will be given type FINAL_TYPE if that is nonzero;
3863 otherwise, it will be given type RESULT_TYPE. */
3866 if (TREE_TYPE (op0) != result_type)
3867 op0 = cp_convert_and_check (result_type, op0);
3868 if (TREE_TYPE (op1) != result_type)
3869 op1 = cp_convert_and_check (result_type, op1);
3871 if (op0 == error_mark_node || op1 == error_mark_node)
3872 return error_mark_node;
3875 if (build_type == NULL_TREE)
3876 build_type = result_type;
3878 result = build2 (resultcode, build_type, op0, op1);
3879 result = fold_if_not_in_template (result);
3880 if (final_type != 0)
3881 result = cp_convert (final_type, result);
3883 if (TREE_OVERFLOW_P (result)
3884 && !TREE_OVERFLOW_P (op0)
3885 && !TREE_OVERFLOW_P (op1))
3886 overflow_warning (result);
3891 /* Return a tree for the sum or difference (RESULTCODE says which)
3892 of pointer PTROP and integer INTOP. */
3895 cp_pointer_int_sum (enum tree_code resultcode, tree ptrop, tree intop)
3897 tree res_type = TREE_TYPE (ptrop);
3899 /* pointer_int_sum() uses size_in_bytes() on the TREE_TYPE(res_type)
3900 in certain circumstance (when it's valid to do so). So we need
3901 to make sure it's complete. We don't need to check here, if we
3902 can actually complete it at all, as those checks will be done in
3903 pointer_int_sum() anyway. */
3904 complete_type (TREE_TYPE (res_type));
3906 return pointer_int_sum (resultcode, ptrop,
3907 fold_if_not_in_template (intop));
3910 /* Return a tree for the difference of pointers OP0 and OP1.
3911 The resulting tree has type int. */
3914 pointer_diff (tree op0, tree op1, tree ptrtype)
3917 tree restype = ptrdiff_type_node;
3918 tree target_type = TREE_TYPE (ptrtype);
3920 if (!complete_type_or_else (target_type, NULL_TREE))
3921 return error_mark_node;
3923 if (pedantic || warn_pointer_arith)
3925 if (TREE_CODE (target_type) == VOID_TYPE)
3926 pedwarn ("ISO C++ forbids using pointer of type %<void *%> in subtraction");
3927 if (TREE_CODE (target_type) == FUNCTION_TYPE)
3928 pedwarn ("ISO C++ forbids using pointer to a function in subtraction");
3929 if (TREE_CODE (target_type) == METHOD_TYPE)
3930 pedwarn ("ISO C++ forbids using pointer to a method in subtraction");
3933 /* First do the subtraction as integers;
3934 then drop through to build the divide operator. */
3936 op0 = cp_build_binary_op (MINUS_EXPR,
3937 cp_convert (restype, op0),
3938 cp_convert (restype, op1));
3940 /* This generates an error if op1 is a pointer to an incomplete type. */
3941 if (!COMPLETE_TYPE_P (TREE_TYPE (TREE_TYPE (op1))))
3942 error ("invalid use of a pointer to an incomplete type in pointer arithmetic");
3944 op1 = (TYPE_PTROB_P (ptrtype)
3945 ? size_in_bytes (target_type)
3946 : integer_one_node);
3948 /* Do the division. */
3950 result = build2 (EXACT_DIV_EXPR, restype, op0, cp_convert (restype, op1));
3951 return fold_if_not_in_template (result);
3954 /* Construct and perhaps optimize a tree representation
3955 for a unary operation. CODE, a tree_code, specifies the operation
3956 and XARG is the operand. */
3959 build_x_unary_op (enum tree_code code, tree xarg)
3961 tree orig_expr = xarg;
3965 if (processing_template_decl)
3967 if (type_dependent_expression_p (xarg))
3968 return build_min_nt (code, xarg, NULL_TREE);
3970 xarg = build_non_dependent_expr (xarg);
3975 /* [expr.unary.op] says:
3977 The address of an object of incomplete type can be taken.
3979 (And is just the ordinary address operator, not an overloaded
3980 "operator &".) However, if the type is a template
3981 specialization, we must complete the type at this point so that
3982 an overloaded "operator &" will be available if required. */
3983 if (code == ADDR_EXPR
3984 && TREE_CODE (xarg) != TEMPLATE_ID_EXPR
3985 && ((CLASS_TYPE_P (TREE_TYPE (xarg))
3986 && !COMPLETE_TYPE_P (complete_type (TREE_TYPE (xarg))))
3987 || (TREE_CODE (xarg) == OFFSET_REF)))
3988 /* Don't look for a function. */;
3990 exp = build_new_op (code, LOOKUP_NORMAL, xarg, NULL_TREE, NULL_TREE,
3991 /*overloaded_p=*/NULL);
3992 if (!exp && code == ADDR_EXPR)
3994 /* A pointer to member-function can be formed only by saying
3996 if (!flag_ms_extensions && TREE_CODE (TREE_TYPE (xarg)) == METHOD_TYPE
3997 && (TREE_CODE (xarg) != OFFSET_REF || !PTRMEM_OK_P (xarg)))
3999 if (TREE_CODE (xarg) != OFFSET_REF
4000 || !TYPE_P (TREE_OPERAND (xarg, 0)))
4002 error ("invalid use of %qE to form a pointer-to-member-function",
4004 if (TREE_CODE (xarg) != OFFSET_REF)
4005 inform (" a qualified-id is required");
4006 return error_mark_node;
4010 error ("parentheses around %qE cannot be used to form a"
4011 " pointer-to-member-function",
4013 PTRMEM_OK_P (xarg) = 1;
4017 if (TREE_CODE (xarg) == OFFSET_REF)
4019 ptrmem = PTRMEM_OK_P (xarg);
4021 if (!ptrmem && !flag_ms_extensions
4022 && TREE_CODE (TREE_TYPE (TREE_OPERAND (xarg, 1))) == METHOD_TYPE)
4024 /* A single non-static member, make sure we don't allow a
4025 pointer-to-member. */
4026 xarg = build2 (OFFSET_REF, TREE_TYPE (xarg),
4027 TREE_OPERAND (xarg, 0),
4028 ovl_cons (TREE_OPERAND (xarg, 1), NULL_TREE));
4029 PTRMEM_OK_P (xarg) = ptrmem;
4032 else if (TREE_CODE (xarg) == TARGET_EXPR)
4033 warning (0, "taking address of temporary");
4034 exp = build_unary_op (ADDR_EXPR, xarg, 0);
4037 if (processing_template_decl && exp != error_mark_node)
4038 exp = build_min_non_dep (code, exp, orig_expr,
4039 /*For {PRE,POST}{INC,DEC}REMENT_EXPR*/NULL_TREE);
4040 if (TREE_CODE (exp) == ADDR_EXPR)
4041 PTRMEM_OK_P (exp) = ptrmem;
4045 /* Like c_common_truthvalue_conversion, but handle pointer-to-member
4046 constants, where a null value is represented by an INTEGER_CST of
4050 cp_truthvalue_conversion (tree expr)
4052 tree type = TREE_TYPE (expr);
4053 if (TYPE_PTRMEM_P (type))
4054 return build_binary_op (NE_EXPR, expr, integer_zero_node, 1);
4056 return c_common_truthvalue_conversion (expr);
4059 /* Just like cp_truthvalue_conversion, but we want a CLEANUP_POINT_EXPR. */
4062 condition_conversion (tree expr)
4065 if (processing_template_decl)
4067 t = perform_implicit_conversion (boolean_type_node, expr);
4068 t = fold_build_cleanup_point_expr (boolean_type_node, t);
4072 /* Return an ADDR_EXPR giving the address of T. This function
4073 attempts no optimizations or simplifications; it is a low-level
4077 build_address (tree t)
4081 if (error_operand_p (t) || !cxx_mark_addressable (t))
4082 return error_mark_node;
4084 addr = build1 (ADDR_EXPR, build_pointer_type (TREE_TYPE (t)), t);
4089 /* Return a NOP_EXPR converting EXPR to TYPE. */
4092 build_nop (tree type, tree expr)
4094 if (type == error_mark_node || error_operand_p (expr))
4096 return build1 (NOP_EXPR, type, expr);
4099 /* C++: Must handle pointers to members.
4101 Perhaps type instantiation should be extended to handle conversion
4102 from aggregates to types we don't yet know we want? (Or are those
4103 cases typically errors which should be reported?)
4105 NOCONVERT nonzero suppresses the default promotions
4106 (such as from short to int). */
4109 build_unary_op (enum tree_code code, tree xarg, int noconvert)
4111 /* No default_conversion here. It causes trouble for ADDR_EXPR. */
4114 const char *errstring = NULL;
4116 const char *invalid_op_diag;
4118 if (arg == error_mark_node)
4119 return error_mark_node;
4121 if ((invalid_op_diag
4122 = targetm.invalid_unary_op ((code == UNARY_PLUS_EXPR
4127 error (invalid_op_diag);
4128 return error_mark_node;
4133 case UNARY_PLUS_EXPR:
4136 int flags = WANT_ARITH | WANT_ENUM;
4137 /* Unary plus (but not unary minus) is allowed on pointers. */
4138 if (code == UNARY_PLUS_EXPR)
4139 flags |= WANT_POINTER;
4140 arg = build_expr_type_conversion (flags, arg, true);
4142 errstring = (code == NEGATE_EXPR
4143 ? "wrong type argument to unary minus"
4144 : "wrong type argument to unary plus");
4147 if (!noconvert && CP_INTEGRAL_TYPE_P (TREE_TYPE (arg)))
4148 arg = perform_integral_promotions (arg);
4150 /* Make sure the result is not an lvalue: a unary plus or minus
4151 expression is always a rvalue. */
4158 if (TREE_CODE (TREE_TYPE (arg)) == COMPLEX_TYPE)
4162 arg = default_conversion (arg);
4164 else if (!(arg = build_expr_type_conversion (WANT_INT | WANT_ENUM
4167 errstring = "wrong type argument to bit-complement";
4168 else if (!noconvert && CP_INTEGRAL_TYPE_P (TREE_TYPE (arg)))
4169 arg = perform_integral_promotions (arg);
4173 if (!(arg = build_expr_type_conversion (WANT_ARITH | WANT_ENUM, arg, true)))
4174 errstring = "wrong type argument to abs";
4175 else if (!noconvert)
4176 arg = default_conversion (arg);
4180 /* Conjugating a real value is a no-op, but allow it anyway. */
4181 if (!(arg = build_expr_type_conversion (WANT_ARITH | WANT_ENUM, arg, true)))
4182 errstring = "wrong type argument to conjugation";
4183 else if (!noconvert)
4184 arg = default_conversion (arg);
4187 case TRUTH_NOT_EXPR:
4188 arg = perform_implicit_conversion (boolean_type_node, arg);
4189 val = invert_truthvalue (arg);
4190 if (arg != error_mark_node)
4192 errstring = "in argument to unary !";
4199 if (TREE_CODE (arg) == COMPLEX_CST)
4200 return TREE_REALPART (arg);
4201 else if (TREE_CODE (TREE_TYPE (arg)) == COMPLEX_TYPE)
4203 arg = build1 (REALPART_EXPR, TREE_TYPE (TREE_TYPE (arg)), arg);
4204 return fold_if_not_in_template (arg);
4210 if (TREE_CODE (arg) == COMPLEX_CST)
4211 return TREE_IMAGPART (arg);
4212 else if (TREE_CODE (TREE_TYPE (arg)) == COMPLEX_TYPE)
4214 arg = build1 (IMAGPART_EXPR, TREE_TYPE (TREE_TYPE (arg)), arg);
4215 return fold_if_not_in_template (arg);
4218 return cp_convert (TREE_TYPE (arg), integer_zero_node);
4220 case PREINCREMENT_EXPR:
4221 case POSTINCREMENT_EXPR:
4222 case PREDECREMENT_EXPR:
4223 case POSTDECREMENT_EXPR:
4224 /* Handle complex lvalues (when permitted)
4225 by reduction to simpler cases. */
4227 val = unary_complex_lvalue (code, arg);
4231 /* Increment or decrement the real part of the value,
4232 and don't change the imaginary part. */
4233 if (TREE_CODE (TREE_TYPE (arg)) == COMPLEX_TYPE)
4237 arg = stabilize_reference (arg);
4238 real = build_unary_op (REALPART_EXPR, arg, 1);
4239 imag = build_unary_op (IMAGPART_EXPR, arg, 1);
4240 real = build_unary_op (code, real, 1);
4241 if (real == error_mark_node || imag == error_mark_node)
4242 return error_mark_node;
4243 return build2 (COMPLEX_EXPR, TREE_TYPE (arg),
4247 /* Report invalid types. */
4249 if (!(arg = build_expr_type_conversion (WANT_ARITH | WANT_POINTER,
4252 if (code == PREINCREMENT_EXPR)
4253 errstring ="no pre-increment operator for type";
4254 else if (code == POSTINCREMENT_EXPR)
4255 errstring ="no post-increment operator for type";
4256 else if (code == PREDECREMENT_EXPR)
4257 errstring ="no pre-decrement operator for type";
4259 errstring ="no post-decrement operator for type";
4263 /* Report something read-only. */
4265 if (CP_TYPE_CONST_P (TREE_TYPE (arg))
4266 || TREE_READONLY (arg))
4267 readonly_error (arg, ((code == PREINCREMENT_EXPR
4268 || code == POSTINCREMENT_EXPR)
4269 ? "increment" : "decrement"));
4274 tree result_type = TREE_TYPE (arg);
4276 declared_type = unlowered_expr_type (arg);
4278 arg = get_unwidened (arg, 0);
4279 argtype = TREE_TYPE (arg);
4281 /* ARM $5.2.5 last annotation says this should be forbidden. */
4282 if (TREE_CODE (argtype) == ENUMERAL_TYPE)
4283 pedwarn ((code == PREINCREMENT_EXPR || code == POSTINCREMENT_EXPR)
4284 ? G_("ISO C++ forbids incrementing an enum")
4285 : G_("ISO C++ forbids decrementing an enum"));
4287 /* Compute the increment. */
4289 if (TREE_CODE (argtype) == POINTER_TYPE)
4291 tree type = complete_type (TREE_TYPE (argtype));
4293 if (!COMPLETE_OR_VOID_TYPE_P (type))
4294 error (((code == PREINCREMENT_EXPR
4295 || code == POSTINCREMENT_EXPR))
4296 ? G_("cannot increment a pointer to incomplete type %qT")
4297 : G_("cannot decrement a pointer to incomplete type %qT"),
4298 TREE_TYPE (argtype));
4299 else if ((pedantic || warn_pointer_arith)
4300 && !TYPE_PTROB_P (argtype))
4301 pedwarn ((code == PREINCREMENT_EXPR
4302 || code == POSTINCREMENT_EXPR)
4303 ? G_("ISO C++ forbids incrementing a pointer of type %qT")
4304 : G_("ISO C++ forbids decrementing a pointer of type %qT"),
4306 inc = cxx_sizeof_nowarn (TREE_TYPE (argtype));
4309 inc = integer_one_node;
4311 inc = cp_convert (argtype, inc);
4313 /* Complain about anything else that is not a true lvalue. */
4314 if (!lvalue_or_else (arg, ((code == PREINCREMENT_EXPR
4315 || code == POSTINCREMENT_EXPR)
4316 ? lv_increment : lv_decrement)))
4317 return error_mark_node;
4319 /* Forbid using -- on `bool'. */
4320 if (same_type_p (declared_type, boolean_type_node))
4322 if (code == POSTDECREMENT_EXPR || code == PREDECREMENT_EXPR)
4324 error ("invalid use of %<--%> on bool variable %qD", arg);
4325 return error_mark_node;
4327 val = boolean_increment (code, arg);
4330 val = build2 (code, TREE_TYPE (arg), arg, inc);
4332 TREE_SIDE_EFFECTS (val) = 1;
4333 return cp_convert (result_type, val);
4337 /* Note that this operation never does default_conversion
4338 regardless of NOCONVERT. */
4340 argtype = lvalue_type (arg);
4342 if (TREE_CODE (arg) == OFFSET_REF)
4345 if (TREE_CODE (argtype) == REFERENCE_TYPE)
4347 tree type = build_pointer_type (TREE_TYPE (argtype));
4348 arg = build1 (CONVERT_EXPR, type, arg);
4351 else if (pedantic && DECL_MAIN_P (arg))
4353 pedwarn ("ISO C++ forbids taking address of function %<::main%>");
4355 /* Let &* cancel out to simplify resulting code. */
4356 if (TREE_CODE (arg) == INDIRECT_REF)
4358 /* We don't need to have `current_class_ptr' wrapped in a
4359 NON_LVALUE_EXPR node. */
4360 if (arg == current_class_ref)
4361 return current_class_ptr;
4363 arg = TREE_OPERAND (arg, 0);
4364 if (TREE_CODE (TREE_TYPE (arg)) == REFERENCE_TYPE)
4366 tree type = build_pointer_type (TREE_TYPE (TREE_TYPE (arg)));
4367 arg = build1 (CONVERT_EXPR, type, arg);
4370 /* Don't let this be an lvalue. */
4375 /* Uninstantiated types are all functions. Taking the
4376 address of a function is a no-op, so just return the
4379 gcc_assert (TREE_CODE (arg) != IDENTIFIER_NODE
4380 || !IDENTIFIER_OPNAME_P (arg));
4382 if (TREE_CODE (arg) == COMPONENT_REF && type_unknown_p (arg)
4383 && !really_overloaded_fn (TREE_OPERAND (arg, 1)))
4385 /* They're trying to take the address of a unique non-static
4386 member function. This is ill-formed (except in MS-land),
4387 but let's try to DTRT.
4388 Note: We only handle unique functions here because we don't
4389 want to complain if there's a static overload; non-unique
4390 cases will be handled by instantiate_type. But we need to
4391 handle this case here to allow casts on the resulting PMF.
4392 We could defer this in non-MS mode, but it's easier to give
4393 a useful error here. */
4395 /* Inside constant member functions, the `this' pointer
4396 contains an extra const qualifier. TYPE_MAIN_VARIANT
4397 is used here to remove this const from the diagnostics
4398 and the created OFFSET_REF. */
4399 tree base = TYPE_MAIN_VARIANT (TREE_TYPE (TREE_OPERAND (arg, 0)));
4400 tree fn = get_first_fn (TREE_OPERAND (arg, 1));
4403 if (! flag_ms_extensions)
4405 tree name = DECL_NAME (fn);
4406 if (current_class_type
4407 && TREE_OPERAND (arg, 0) == current_class_ref)
4408 /* An expression like &memfn. */
4409 pedwarn ("ISO C++ forbids taking the address of an unqualified"
4410 " or parenthesized non-static member function to form"
4411 " a pointer to member function. Say %<&%T::%D%>",
4414 pedwarn ("ISO C++ forbids taking the address of a bound member"
4415 " function to form a pointer to member function."
4419 arg = build_offset_ref (base, fn, /*address_p=*/true);
4423 if (type_unknown_p (arg))
4424 return build1 (ADDR_EXPR, unknown_type_node, arg);
4426 /* Handle complex lvalues (when permitted)
4427 by reduction to simpler cases. */
4428 val = unary_complex_lvalue (code, arg);
4432 switch (TREE_CODE (arg))
4437 case FIX_TRUNC_EXPR:
4438 if (! lvalue_p (arg) && pedantic)
4439 pedwarn ("ISO C++ forbids taking the address of a cast to a non-lvalue expression");
4443 arg = BASELINK_FUNCTIONS (arg);
4447 arg = OVL_CURRENT (arg);
4451 /* Turn a reference to a non-static data member into a
4452 pointer-to-member. */
4457 if (!PTRMEM_OK_P (arg))
4458 return build_unary_op (code, arg, 0);
4460 t = TREE_OPERAND (arg, 1);
4461 if (TREE_CODE (TREE_TYPE (t)) == REFERENCE_TYPE)
4463 error ("cannot create pointer to reference member %qD", t);
4464 return error_mark_node;
4467 type = build_ptrmem_type (context_for_name_lookup (t),
4469 t = make_ptrmem_cst (type, TREE_OPERAND (arg, 1));
4477 /* Anything not already handled and not a true memory reference
4479 if (TREE_CODE (argtype) != FUNCTION_TYPE
4480 && TREE_CODE (argtype) != METHOD_TYPE
4481 && TREE_CODE (arg) != OFFSET_REF
4482 && !lvalue_or_else (arg, lv_addressof))
4483 return error_mark_node;
4485 if (argtype != error_mark_node)
4486 argtype = build_pointer_type (argtype);
4488 /* In a template, we are processing a non-dependent expression
4489 so we can just form an ADDR_EXPR with the correct type. */
4490 if (processing_template_decl)
4492 val = build_address (arg);
4493 if (TREE_CODE (arg) == OFFSET_REF)
4494 PTRMEM_OK_P (val) = PTRMEM_OK_P (arg);
4498 if (TREE_CODE (arg) != COMPONENT_REF)
4500 val = build_address (arg);
4501 if (TREE_CODE (arg) == OFFSET_REF)
4502 PTRMEM_OK_P (val) = PTRMEM_OK_P (arg);
4504 else if (TREE_CODE (TREE_OPERAND (arg, 1)) == BASELINK)
4506 tree fn = BASELINK_FUNCTIONS (TREE_OPERAND (arg, 1));
4508 /* We can only get here with a single static member
4510 gcc_assert (TREE_CODE (fn) == FUNCTION_DECL
4511 && DECL_STATIC_FUNCTION_P (fn));
4513 val = build_address (fn);
4514 if (TREE_SIDE_EFFECTS (TREE_OPERAND (arg, 0)))
4515 /* Do not lose object's side effects. */
4516 val = build2 (COMPOUND_EXPR, TREE_TYPE (val),
4517 TREE_OPERAND (arg, 0), val);
4519 else if (DECL_C_BIT_FIELD (TREE_OPERAND (arg, 1)))
4521 error ("attempt to take address of bit-field structure member %qD",
4522 TREE_OPERAND (arg, 1));
4523 return error_mark_node;
4527 tree object = TREE_OPERAND (arg, 0);
4528 tree field = TREE_OPERAND (arg, 1);
4529 gcc_assert (same_type_ignoring_top_level_qualifiers_p
4530 (TREE_TYPE (object), decl_type_context (field)));
4531 val = build_address (arg);
4534 if (TREE_CODE (argtype) == POINTER_TYPE
4535 && TREE_CODE (TREE_TYPE (argtype)) == METHOD_TYPE)
4537 build_ptrmemfunc_type (argtype);
4538 val = build_ptrmemfunc (argtype, val, 0,
4539 /*c_cast_p=*/false);
4551 argtype = TREE_TYPE (arg);
4552 return fold_if_not_in_template (build1 (code, argtype, arg));
4555 error ("%s", errstring);
4556 return error_mark_node;
4559 /* Apply unary lvalue-demanding operator CODE to the expression ARG
4560 for certain kinds of expressions which are not really lvalues
4561 but which we can accept as lvalues.
4563 If ARG is not a kind of expression we can handle, return
4567 unary_complex_lvalue (enum tree_code code, tree arg)
4569 /* Inside a template, making these kinds of adjustments is
4570 pointless; we are only concerned with the type of the
4572 if (processing_template_decl)
4575 /* Handle (a, b) used as an "lvalue". */
4576 if (TREE_CODE (arg) == COMPOUND_EXPR)
4578 tree real_result = build_unary_op (code, TREE_OPERAND (arg, 1), 0);
4579 return build2 (COMPOUND_EXPR, TREE_TYPE (real_result),
4580 TREE_OPERAND (arg, 0), real_result);
4583 /* Handle (a ? b : c) used as an "lvalue". */
4584 if (TREE_CODE (arg) == COND_EXPR
4585 || TREE_CODE (arg) == MIN_EXPR || TREE_CODE (arg) == MAX_EXPR)
4586 return rationalize_conditional_expr (code, arg);
4588 /* Handle (a = b), (++a), and (--a) used as an "lvalue". */
4589 if (TREE_CODE (arg) == MODIFY_EXPR
4590 || TREE_CODE (arg) == PREINCREMENT_EXPR
4591 || TREE_CODE (arg) == PREDECREMENT_EXPR)
4593 tree lvalue = TREE_OPERAND (arg, 0);
4594 if (TREE_SIDE_EFFECTS (lvalue))
4596 lvalue = stabilize_reference (lvalue);
4597 arg = build2 (TREE_CODE (arg), TREE_TYPE (arg),
4598 lvalue, TREE_OPERAND (arg, 1));
4600 return unary_complex_lvalue
4601 (code, build2 (COMPOUND_EXPR, TREE_TYPE (lvalue), arg, lvalue));
4604 if (code != ADDR_EXPR)
4607 /* Handle (a = b) used as an "lvalue" for `&'. */
4608 if (TREE_CODE (arg) == MODIFY_EXPR
4609 || TREE_CODE (arg) == INIT_EXPR)
4611 tree real_result = build_unary_op (code, TREE_OPERAND (arg, 0), 0);
4612 arg = build2 (COMPOUND_EXPR, TREE_TYPE (real_result),
4614 TREE_NO_WARNING (arg) = 1;
4618 if (TREE_CODE (TREE_TYPE (arg)) == FUNCTION_TYPE
4619 || TREE_CODE (TREE_TYPE (arg)) == METHOD_TYPE
4620 || TREE_CODE (arg) == OFFSET_REF)
4623 /* We permit compiler to make function calls returning
4624 objects of aggregate type look like lvalues. */
4628 if (TREE_CODE (targ) == SAVE_EXPR)
4629 targ = TREE_OPERAND (targ, 0);
4631 if (TREE_CODE (targ) == CALL_EXPR && IS_AGGR_TYPE (TREE_TYPE (targ)))
4633 if (TREE_CODE (arg) == SAVE_EXPR)
4636 targ = build_cplus_new (TREE_TYPE (arg), arg);
4637 return build1 (ADDR_EXPR, build_pointer_type (TREE_TYPE (arg)), targ);
4640 if (TREE_CODE (arg) == SAVE_EXPR && TREE_CODE (targ) == INDIRECT_REF)
4641 return build3 (SAVE_EXPR, build_pointer_type (TREE_TYPE (arg)),
4642 TREE_OPERAND (targ, 0), current_function_decl, NULL);
4645 /* Don't let anything else be handled specially. */
4649 /* Mark EXP saying that we need to be able to take the
4650 address of it; it should not be allocated in a register.
4651 Value is true if successful.
4653 C++: we do not allow `current_class_ptr' to be addressable. */
4656 cxx_mark_addressable (tree exp)
4661 switch (TREE_CODE (x))
4668 x = TREE_OPERAND (x, 0);
4672 if (x == current_class_ptr)
4674 error ("cannot take the address of %<this%>, which is an rvalue expression");
4675 TREE_ADDRESSABLE (x) = 1; /* so compiler doesn't die later. */
4681 /* Caller should not be trying to mark initialized
4682 constant fields addressable. */
4683 gcc_assert (DECL_LANG_SPECIFIC (x) == 0
4684 || DECL_IN_AGGR_P (x) == 0
4686 || DECL_EXTERNAL (x));
4691 if (DECL_REGISTER (x) && !TREE_ADDRESSABLE (x)
4692 && !DECL_ARTIFICIAL (x))
4694 if (TREE_CODE (x) == VAR_DECL && DECL_HARD_REGISTER (x))
4697 ("address of explicit register variable %qD requested", x);
4700 else if (extra_warnings)
4702 (OPT_Wextra, "address requested for %qD, which is declared %<register%>", x);
4704 TREE_ADDRESSABLE (x) = 1;
4708 TREE_ADDRESSABLE (x) = 1;
4712 TREE_ADDRESSABLE (x) = 1;
4716 TREE_ADDRESSABLE (x) = 1;
4717 cxx_mark_addressable (TREE_OPERAND (x, 0));
4725 /* Build and return a conditional expression IFEXP ? OP1 : OP2. */
4728 build_x_conditional_expr (tree ifexp, tree op1, tree op2)
4730 tree orig_ifexp = ifexp;
4731 tree orig_op1 = op1;
4732 tree orig_op2 = op2;
4735 if (processing_template_decl)
4737 /* The standard says that the expression is type-dependent if
4738 IFEXP is type-dependent, even though the eventual type of the
4739 expression doesn't dependent on IFEXP. */
4740 if (type_dependent_expression_p (ifexp)
4741 /* As a GNU extension, the middle operand may be omitted. */
4742 || (op1 && type_dependent_expression_p (op1))
4743 || type_dependent_expression_p (op2))
4744 return build_min_nt (COND_EXPR, ifexp, op1, op2);
4745 ifexp = build_non_dependent_expr (ifexp);
4747 op1 = build_non_dependent_expr (op1);
4748 op2 = build_non_dependent_expr (op2);
4751 expr = build_conditional_expr (ifexp, op1, op2);
4752 if (processing_template_decl && expr != error_mark_node)
4753 return build_min_non_dep (COND_EXPR, expr,
4754 orig_ifexp, orig_op1, orig_op2);
4758 /* Given a list of expressions, return a compound expression
4759 that performs them all and returns the value of the last of them. */
4761 tree build_x_compound_expr_from_list (tree list, const char *msg)
4763 tree expr = TREE_VALUE (list);
4765 if (TREE_CHAIN (list))
4768 pedwarn ("%s expression list treated as compound expression", msg);
4770 for (list = TREE_CHAIN (list); list; list = TREE_CHAIN (list))
4771 expr = build_x_compound_expr (expr, TREE_VALUE (list));
4777 /* Handle overloading of the ',' operator when needed. */
4780 build_x_compound_expr (tree op1, tree op2)
4783 tree orig_op1 = op1;
4784 tree orig_op2 = op2;
4786 if (processing_template_decl)
4788 if (type_dependent_expression_p (op1)
4789 || type_dependent_expression_p (op2))
4790 return build_min_nt (COMPOUND_EXPR, op1, op2);
4791 op1 = build_non_dependent_expr (op1);
4792 op2 = build_non_dependent_expr (op2);
4795 result = build_new_op (COMPOUND_EXPR, LOOKUP_NORMAL, op1, op2, NULL_TREE,
4796 /*overloaded_p=*/NULL);
4798 result = build_compound_expr (op1, op2);
4800 if (processing_template_decl && result != error_mark_node)
4801 return build_min_non_dep (COMPOUND_EXPR, result, orig_op1, orig_op2);
4806 /* Build a compound expression. */
4809 build_compound_expr (tree lhs, tree rhs)
4811 lhs = convert_to_void (lhs, "left-hand operand of comma");
4813 if (lhs == error_mark_node || rhs == error_mark_node)
4814 return error_mark_node;
4816 if (TREE_CODE (rhs) == TARGET_EXPR)
4818 /* If the rhs is a TARGET_EXPR, then build the compound
4819 expression inside the target_expr's initializer. This
4820 helps the compiler to eliminate unnecessary temporaries. */
4821 tree init = TREE_OPERAND (rhs, 1);
4823 init = build2 (COMPOUND_EXPR, TREE_TYPE (init), lhs, init);
4824 TREE_OPERAND (rhs, 1) = init;
4829 return build2 (COMPOUND_EXPR, TREE_TYPE (rhs), lhs, rhs);
4832 /* Issue a diagnostic message if casting from SRC_TYPE to DEST_TYPE
4833 casts away constness. DIAG_FN gives the function to call if we
4834 need to issue a diagnostic; if it is NULL, no diagnostic will be
4835 issued. DESCRIPTION explains what operation is taking place. */
4838 check_for_casting_away_constness (tree src_type, tree dest_type,
4839 void (*diag_fn)(const char *, ...) ATTRIBUTE_GCC_CXXDIAG(1,2),
4840 const char *description)
4842 if (diag_fn && casts_away_constness (src_type, dest_type))
4843 diag_fn ("%s from type %qT to type %qT casts away constness",
4844 description, src_type, dest_type);
4847 /* Convert EXPR (an expression with pointer-to-member type) to TYPE
4848 (another pointer-to-member type in the same hierarchy) and return
4849 the converted expression. If ALLOW_INVERSE_P is permitted, a
4850 pointer-to-derived may be converted to pointer-to-base; otherwise,
4851 only the other direction is permitted. If C_CAST_P is true, this
4852 conversion is taking place as part of a C-style cast. */
4855 convert_ptrmem (tree type, tree expr, bool allow_inverse_p,
4858 if (TYPE_PTRMEM_P (type))
4862 if (TREE_CODE (expr) == PTRMEM_CST)
4863 expr = cplus_expand_constant (expr);
4864 delta = get_delta_difference (TYPE_PTRMEM_CLASS_TYPE (TREE_TYPE (expr)),
4865 TYPE_PTRMEM_CLASS_TYPE (type),
4868 if (!integer_zerop (delta))
4869 expr = cp_build_binary_op (PLUS_EXPR,
4870 build_nop (ptrdiff_type_node, expr),
4872 return build_nop (type, expr);
4875 return build_ptrmemfunc (TYPE_PTRMEMFUNC_FN_TYPE (type), expr,
4876 allow_inverse_p, c_cast_p);
4879 /* If EXPR is an INTEGER_CST and ORIG is an arithmetic constant, return
4880 a version of EXPR that has TREE_OVERFLOW set if it is set in ORIG.
4881 Otherwise, return EXPR unchanged. */
4884 ignore_overflows (tree expr, tree orig)
4886 if (TREE_CODE (expr) == INTEGER_CST
4887 && CONSTANT_CLASS_P (orig)
4888 && TREE_CODE (orig) != STRING_CST
4889 && TREE_OVERFLOW (expr) != TREE_OVERFLOW (orig))
4891 if (!TREE_OVERFLOW (orig))
4892 /* Ensure constant sharing. */
4893 expr = build_int_cst_wide (TREE_TYPE (expr),
4894 TREE_INT_CST_LOW (expr),
4895 TREE_INT_CST_HIGH (expr));
4898 /* Avoid clobbering a shared constant. */
4899 expr = copy_node (expr);
4900 TREE_OVERFLOW (expr) = TREE_OVERFLOW (orig);
4906 /* Perform a static_cast from EXPR to TYPE. When C_CAST_P is true,
4907 this static_cast is being attempted as one of the possible casts
4908 allowed by a C-style cast. (In that case, accessibility of base
4909 classes is not considered, and it is OK to cast away
4910 constness.) Return the result of the cast. *VALID_P is set to
4911 indicate whether or not the cast was valid. */
4914 build_static_cast_1 (tree type, tree expr, bool c_cast_p,
4920 void (*diag_fn)(const char*, ...) ATTRIBUTE_GCC_CXXDIAG(1,2);
4923 /* Assume the cast is valid. */
4926 intype = TREE_TYPE (expr);
4928 /* Save casted types in the function's used types hash table. */
4929 used_types_insert (type);
4931 /* Determine what to do when casting away constness. */
4934 /* C-style casts are allowed to cast away constness. With
4935 WARN_CAST_QUAL, we still want to issue a warning. */
4936 diag_fn = warn_cast_qual ? warning0 : NULL;
4941 /* A static_cast may not cast away constness. */
4943 desc = "static_cast";
4946 /* [expr.static.cast]
4948 An lvalue of type "cv1 B", where B is a class type, can be cast
4949 to type "reference to cv2 D", where D is a class derived (clause
4950 _class.derived_) from B, if a valid standard conversion from
4951 "pointer to D" to "pointer to B" exists (_conv.ptr_), cv2 is the
4952 same cv-qualification as, or greater cv-qualification than, cv1,
4953 and B is not a virtual base class of D. */
4954 /* We check this case before checking the validity of "TYPE t =
4955 EXPR;" below because for this case:
4958 struct D : public B { D(const B&); };
4960 void f() { static_cast<const D&>(b); }
4962 we want to avoid constructing a new D. The standard is not
4963 completely clear about this issue, but our interpretation is
4964 consistent with other compilers. */
4965 if (TREE_CODE (type) == REFERENCE_TYPE
4966 && CLASS_TYPE_P (TREE_TYPE (type))
4967 && CLASS_TYPE_P (intype)
4968 && real_lvalue_p (expr)
4969 && DERIVED_FROM_P (intype, TREE_TYPE (type))
4970 && can_convert (build_pointer_type (TYPE_MAIN_VARIANT (intype)),
4971 build_pointer_type (TYPE_MAIN_VARIANT
4972 (TREE_TYPE (type))))
4974 || at_least_as_qualified_p (TREE_TYPE (type), intype)))
4978 /* There is a standard conversion from "D*" to "B*" even if "B"
4979 is ambiguous or inaccessible. If this is really a
4980 static_cast, then we check both for inaccessibility and
4981 ambiguity. However, if this is a static_cast being performed
4982 because the user wrote a C-style cast, then accessibility is
4984 base = lookup_base (TREE_TYPE (type), intype,
4985 c_cast_p ? ba_unique : ba_check,
4988 /* Convert from "B*" to "D*". This function will check that "B"
4989 is not a virtual base of "D". */
4990 expr = build_base_path (MINUS_EXPR, build_address (expr),
4991 base, /*nonnull=*/false);
4992 /* Convert the pointer to a reference -- but then remember that
4993 there are no expressions with reference type in C++. */
4994 return convert_from_reference (build_nop (type, expr));
4999 /* [expr.static.cast]
5001 An expression e can be explicitly converted to a type T using a
5002 static_cast of the form static_cast<T>(e) if the declaration T
5003 t(e);" is well-formed, for some invented temporary variable
5005 result = perform_direct_initialization_if_possible (type, expr,
5009 result = convert_from_reference (result);
5011 /* Ignore any integer overflow caused by the cast. */
5012 result = ignore_overflows (result, orig);
5014 /* [expr.static.cast]
5016 If T is a reference type, the result is an lvalue; otherwise,
5017 the result is an rvalue. */
5018 if (TREE_CODE (type) != REFERENCE_TYPE)
5019 result = rvalue (result);
5023 /* [expr.static.cast]
5025 Any expression can be explicitly converted to type cv void. */
5026 if (TREE_CODE (type) == VOID_TYPE)
5027 return convert_to_void (expr, /*implicit=*/NULL);
5029 /* [expr.static.cast]
5031 The inverse of any standard conversion sequence (clause _conv_),
5032 other than the lvalue-to-rvalue (_conv.lval_), array-to-pointer
5033 (_conv.array_), function-to-pointer (_conv.func_), and boolean
5034 (_conv.bool_) conversions, can be performed explicitly using
5035 static_cast subject to the restriction that the explicit
5036 conversion does not cast away constness (_expr.const.cast_), and
5037 the following additional rules for specific cases: */
5038 /* For reference, the conversions not excluded are: integral
5039 promotions, floating point promotion, integral conversions,
5040 floating point conversions, floating-integral conversions,
5041 pointer conversions, and pointer to member conversions. */
5044 A value of integral _or enumeration_ type can be explicitly
5045 converted to an enumeration type. */
5046 /* The effect of all that is that any conversion between any two
5047 types which are integral, floating, or enumeration types can be
5049 if ((INTEGRAL_TYPE_P (type) || SCALAR_FLOAT_TYPE_P (type))
5050 && (INTEGRAL_TYPE_P (intype) || SCALAR_FLOAT_TYPE_P (intype)))
5052 expr = ocp_convert (type, expr, CONV_C_CAST, LOOKUP_NORMAL);
5054 /* Ignore any integer overflow caused by the cast. */
5055 expr = ignore_overflows (expr, orig);
5059 if (TYPE_PTR_P (type) && TYPE_PTR_P (intype)
5060 && CLASS_TYPE_P (TREE_TYPE (type))
5061 && CLASS_TYPE_P (TREE_TYPE (intype))
5062 && can_convert (build_pointer_type (TYPE_MAIN_VARIANT
5063 (TREE_TYPE (intype))),
5064 build_pointer_type (TYPE_MAIN_VARIANT
5065 (TREE_TYPE (type)))))
5070 check_for_casting_away_constness (intype, type, diag_fn, desc);
5071 base = lookup_base (TREE_TYPE (type), TREE_TYPE (intype),
5072 c_cast_p ? ba_unique : ba_check,
5074 return build_base_path (MINUS_EXPR, expr, base, /*nonnull=*/false);
5077 if ((TYPE_PTRMEM_P (type) && TYPE_PTRMEM_P (intype))
5078 || (TYPE_PTRMEMFUNC_P (type) && TYPE_PTRMEMFUNC_P (intype)))
5085 c1 = TYPE_PTRMEM_CLASS_TYPE (intype);
5086 c2 = TYPE_PTRMEM_CLASS_TYPE (type);
5088 if (TYPE_PTRMEM_P (type))
5090 t1 = (build_ptrmem_type
5092 TYPE_MAIN_VARIANT (TYPE_PTRMEM_POINTED_TO_TYPE (intype))));
5093 t2 = (build_ptrmem_type
5095 TYPE_MAIN_VARIANT (TYPE_PTRMEM_POINTED_TO_TYPE (type))));
5102 if (can_convert (t1, t2))
5105 check_for_casting_away_constness (intype, type, diag_fn,
5107 return convert_ptrmem (type, expr, /*allow_inverse_p=*/1,
5112 /* [expr.static.cast]
5114 An rvalue of type "pointer to cv void" can be explicitly
5115 converted to a pointer to object type. A value of type pointer
5116 to object converted to "pointer to cv void" and back to the
5117 original pointer type will have its original value. */
5118 if (TREE_CODE (intype) == POINTER_TYPE
5119 && VOID_TYPE_P (TREE_TYPE (intype))
5120 && TYPE_PTROB_P (type))
5123 check_for_casting_away_constness (intype, type, diag_fn, desc);
5124 return build_nop (type, expr);
5128 return error_mark_node;
5131 /* Return an expression representing static_cast<TYPE>(EXPR). */
5134 build_static_cast (tree type, tree expr)
5139 if (type == error_mark_node || expr == error_mark_node)
5140 return error_mark_node;
5142 if (processing_template_decl)
5144 expr = build_min (STATIC_CAST_EXPR, type, expr);
5145 /* We don't know if it will or will not have side effects. */
5146 TREE_SIDE_EFFECTS (expr) = 1;
5147 return convert_from_reference (expr);
5150 /* build_c_cast puts on a NOP_EXPR to make the result not an lvalue.
5151 Strip such NOP_EXPRs if VALUE is being used in non-lvalue context. */
5152 if (TREE_CODE (type) != REFERENCE_TYPE
5153 && TREE_CODE (expr) == NOP_EXPR
5154 && TREE_TYPE (expr) == TREE_TYPE (TREE_OPERAND (expr, 0)))
5155 expr = TREE_OPERAND (expr, 0);
5157 result = build_static_cast_1 (type, expr, /*c_cast_p=*/false, &valid_p);
5161 error ("invalid static_cast from type %qT to type %qT",
5162 TREE_TYPE (expr), type);
5163 return error_mark_node;
5166 /* EXPR is an expression with member function or pointer-to-member
5167 function type. TYPE is a pointer type. Converting EXPR to TYPE is
5168 not permitted by ISO C++, but we accept it in some modes. If we
5169 are not in one of those modes, issue a diagnostic. Return the
5170 converted expression. */
5173 convert_member_func_to_ptr (tree type, tree expr)
5178 intype = TREE_TYPE (expr);
5179 gcc_assert (TYPE_PTRMEMFUNC_P (intype)
5180 || TREE_CODE (intype) == METHOD_TYPE);
5182 if (pedantic || warn_pmf2ptr)
5183 pedwarn ("converting from %qT to %qT", intype, type);
5185 if (TREE_CODE (intype) == METHOD_TYPE)
5186 expr = build_addr_func (expr);
5187 else if (TREE_CODE (expr) == PTRMEM_CST)
5188 expr = build_address (PTRMEM_CST_MEMBER (expr));
5191 decl = maybe_dummy_object (TYPE_PTRMEM_CLASS_TYPE (intype), 0);
5192 decl = build_address (decl);
5193 expr = get_member_function_from_ptrfunc (&decl, expr);
5196 return build_nop (type, expr);
5199 /* Return a representation for a reinterpret_cast from EXPR to TYPE.
5200 If C_CAST_P is true, this reinterpret cast is being done as part of
5201 a C-style cast. If VALID_P is non-NULL, *VALID_P is set to
5202 indicate whether or not reinterpret_cast was valid. */
5205 build_reinterpret_cast_1 (tree type, tree expr, bool c_cast_p,
5210 /* Assume the cast is invalid. */
5214 if (type == error_mark_node || error_operand_p (expr))
5215 return error_mark_node;
5217 intype = TREE_TYPE (expr);
5219 /* Save casted types in the function's used types hash table. */
5220 used_types_insert (type);
5222 /* [expr.reinterpret.cast]
5223 An lvalue expression of type T1 can be cast to the type
5224 "reference to T2" if an expression of type "pointer to T1" can be
5225 explicitly converted to the type "pointer to T2" using a
5226 reinterpret_cast. */
5227 if (TREE_CODE (type) == REFERENCE_TYPE)
5229 if (! real_lvalue_p (expr))
5231 error ("invalid cast of an rvalue expression of type "
5234 return error_mark_node;
5237 /* Warn about a reinterpret_cast from "A*" to "B&" if "A" and
5238 "B" are related class types; the reinterpret_cast does not
5239 adjust the pointer. */
5240 if (TYPE_PTR_P (intype)
5241 && (comptypes (TREE_TYPE (intype), TREE_TYPE (type),
5242 COMPARE_BASE | COMPARE_DERIVED)))
5243 warning (0, "casting %qT to %qT does not dereference pointer",
5246 expr = build_unary_op (ADDR_EXPR, expr, 0);
5247 if (expr != error_mark_node)
5248 expr = build_reinterpret_cast_1
5249 (build_pointer_type (TREE_TYPE (type)), expr, c_cast_p,
5251 if (expr != error_mark_node)
5252 expr = build_indirect_ref (expr, 0);
5256 /* As a G++ extension, we consider conversions from member
5257 functions, and pointers to member functions to
5258 pointer-to-function and pointer-to-void types. If
5259 -Wno-pmf-conversions has not been specified,
5260 convert_member_func_to_ptr will issue an error message. */
5261 if ((TYPE_PTRMEMFUNC_P (intype)
5262 || TREE_CODE (intype) == METHOD_TYPE)
5263 && TYPE_PTR_P (type)
5264 && (TREE_CODE (TREE_TYPE (type)) == FUNCTION_TYPE
5265 || VOID_TYPE_P (TREE_TYPE (type))))
5266 return convert_member_func_to_ptr (type, expr);
5268 /* If the cast is not to a reference type, the lvalue-to-rvalue,
5269 array-to-pointer, and function-to-pointer conversions are
5271 expr = decay_conversion (expr);
5273 /* build_c_cast puts on a NOP_EXPR to make the result not an lvalue.
5274 Strip such NOP_EXPRs if VALUE is being used in non-lvalue context. */
5275 if (TREE_CODE (expr) == NOP_EXPR
5276 && TREE_TYPE (expr) == TREE_TYPE (TREE_OPERAND (expr, 0)))
5277 expr = TREE_OPERAND (expr, 0);
5279 if (error_operand_p (expr))
5280 return error_mark_node;
5282 intype = TREE_TYPE (expr);
5284 /* [expr.reinterpret.cast]
5285 A pointer can be converted to any integral type large enough to
5287 if (CP_INTEGRAL_TYPE_P (type) && TYPE_PTR_P (intype))
5289 if (TYPE_PRECISION (type) < TYPE_PRECISION (intype))
5290 pedwarn ("cast from %qT to %qT loses precision",
5293 /* [expr.reinterpret.cast]
5294 A value of integral or enumeration type can be explicitly
5295 converted to a pointer. */
5296 else if (TYPE_PTR_P (type) && INTEGRAL_OR_ENUMERATION_TYPE_P (intype))
5299 else if ((TYPE_PTRFN_P (type) && TYPE_PTRFN_P (intype))
5300 || (TYPE_PTRMEMFUNC_P (type) && TYPE_PTRMEMFUNC_P (intype)))
5301 return fold_if_not_in_template (build_nop (type, expr));
5302 else if ((TYPE_PTRMEM_P (type) && TYPE_PTRMEM_P (intype))
5303 || (TYPE_PTROBV_P (type) && TYPE_PTROBV_P (intype)))
5308 check_for_casting_away_constness (intype, type, error,
5309 "reinterpret_cast");
5310 /* Warn about possible alignment problems. */
5311 if (STRICT_ALIGNMENT && warn_cast_align
5312 && !VOID_TYPE_P (type)
5313 && TREE_CODE (TREE_TYPE (intype)) != FUNCTION_TYPE
5314 && COMPLETE_TYPE_P (TREE_TYPE (type))
5315 && COMPLETE_TYPE_P (TREE_TYPE (intype))
5316 && TYPE_ALIGN (TREE_TYPE (type)) > TYPE_ALIGN (TREE_TYPE (intype)))
5317 warning (0, "cast from %qT to %qT increases required alignment of "
5321 /* We need to strip nops here, because the front end likes to
5322 create (int *)&a for array-to-pointer decay, instead of &a[0]. */
5324 if (warn_strict_aliasing <= 2)
5325 strict_aliasing_warning (intype, type, sexpr);
5327 return fold_if_not_in_template (build_nop (type, expr));
5329 else if ((TYPE_PTRFN_P (type) && TYPE_PTROBV_P (intype))
5330 || (TYPE_PTRFN_P (intype) && TYPE_PTROBV_P (type)))
5333 /* Only issue a warning, as we have always supported this
5334 where possible, and it is necessary in some cases. DR 195
5335 addresses this issue, but as of 2004/10/26 is still in
5337 warning (0, "ISO C++ forbids casting between pointer-to-function and pointer-to-object");
5338 return fold_if_not_in_template (build_nop (type, expr));
5340 else if (TREE_CODE (type) == VECTOR_TYPE)
5341 return fold_if_not_in_template (convert_to_vector (type, expr));
5342 else if (TREE_CODE (intype) == VECTOR_TYPE && INTEGRAL_TYPE_P (type))
5343 return fold_if_not_in_template (convert_to_integer (type, expr));
5348 error ("invalid cast from type %qT to type %qT", intype, type);
5349 return error_mark_node;
5352 return cp_convert (type, expr);
5356 build_reinterpret_cast (tree type, tree expr)
5358 if (type == error_mark_node || expr == error_mark_node)
5359 return error_mark_node;
5361 if (processing_template_decl)
5363 tree t = build_min (REINTERPRET_CAST_EXPR, type, expr);
5365 if (!TREE_SIDE_EFFECTS (t)
5366 && type_dependent_expression_p (expr))
5367 /* There might turn out to be side effects inside expr. */
5368 TREE_SIDE_EFFECTS (t) = 1;
5369 return convert_from_reference (t);
5372 return build_reinterpret_cast_1 (type, expr, /*c_cast_p=*/false,
5376 /* Perform a const_cast from EXPR to TYPE. If the cast is valid,
5377 return an appropriate expression. Otherwise, return
5378 error_mark_node. If the cast is not valid, and COMPLAIN is true,
5379 then a diagnostic will be issued. If VALID_P is non-NULL, we are
5380 performing a C-style cast, its value upon return will indicate
5381 whether or not the conversion succeeded. */
5384 build_const_cast_1 (tree dst_type, tree expr, bool complain,
5388 tree reference_type;
5390 /* Callers are responsible for handling error_mark_node as a
5391 destination type. */
5392 gcc_assert (dst_type != error_mark_node);
5393 /* In a template, callers should be building syntactic
5394 representations of casts, not using this machinery. */
5395 gcc_assert (!processing_template_decl);
5397 /* Assume the conversion is invalid. */
5401 if (!POINTER_TYPE_P (dst_type) && !TYPE_PTRMEM_P (dst_type))
5404 error ("invalid use of const_cast with type %qT, "
5405 "which is not a pointer, "
5406 "reference, nor a pointer-to-data-member type", dst_type);
5407 return error_mark_node;
5410 if (TREE_CODE (TREE_TYPE (dst_type)) == FUNCTION_TYPE)
5413 error ("invalid use of const_cast with type %qT, which is a pointer "
5414 "or reference to a function type", dst_type);
5415 return error_mark_node;
5418 /* Save casted types in the function's used types hash table. */
5419 used_types_insert (dst_type);
5421 src_type = TREE_TYPE (expr);
5422 /* Expressions do not really have reference types. */
5423 if (TREE_CODE (src_type) == REFERENCE_TYPE)
5424 src_type = TREE_TYPE (src_type);
5426 /* [expr.const.cast]
5428 An lvalue of type T1 can be explicitly converted to an lvalue of
5429 type T2 using the cast const_cast<T2&> (where T1 and T2 are object
5430 types) if a pointer to T1 can be explicitly converted to the type
5431 pointer to T2 using a const_cast. */
5432 if (TREE_CODE (dst_type) == REFERENCE_TYPE)
5434 reference_type = dst_type;
5435 if (! real_lvalue_p (expr))
5438 error ("invalid const_cast of an rvalue of type %qT to type %qT",
5439 src_type, dst_type);
5440 return error_mark_node;
5442 dst_type = build_pointer_type (TREE_TYPE (dst_type));
5443 src_type = build_pointer_type (src_type);
5447 reference_type = NULL_TREE;
5448 /* If the destination type is not a reference type, the
5449 lvalue-to-rvalue, array-to-pointer, and function-to-pointer
5450 conversions are performed. */
5451 src_type = type_decays_to (src_type);
5452 if (src_type == error_mark_node)
5453 return error_mark_node;
5456 if ((TYPE_PTR_P (src_type) || TYPE_PTRMEM_P (src_type))
5457 && comp_ptr_ttypes_const (dst_type, src_type))
5462 /* This cast is actually a C-style cast. Issue a warning if
5463 the user is making a potentially unsafe cast. */
5465 check_for_casting_away_constness (src_type, dst_type,
5471 expr = build_unary_op (ADDR_EXPR, expr, 0);
5472 expr = build_nop (reference_type, expr);
5473 return convert_from_reference (expr);
5477 expr = decay_conversion (expr);
5478 /* build_c_cast puts on a NOP_EXPR to make the result not an
5479 lvalue. Strip such NOP_EXPRs if VALUE is being used in
5480 non-lvalue context. */
5481 if (TREE_CODE (expr) == NOP_EXPR
5482 && TREE_TYPE (expr) == TREE_TYPE (TREE_OPERAND (expr, 0)))
5483 expr = TREE_OPERAND (expr, 0);
5484 return build_nop (dst_type, expr);
5489 error ("invalid const_cast from type %qT to type %qT",
5490 src_type, dst_type);
5491 return error_mark_node;
5495 build_const_cast (tree type, tree expr)
5497 if (type == error_mark_node || error_operand_p (expr))
5498 return error_mark_node;
5500 if (processing_template_decl)
5502 tree t = build_min (CONST_CAST_EXPR, type, expr);
5504 if (!TREE_SIDE_EFFECTS (t)
5505 && type_dependent_expression_p (expr))
5506 /* There might turn out to be side effects inside expr. */
5507 TREE_SIDE_EFFECTS (t) = 1;
5508 return convert_from_reference (t);
5511 return build_const_cast_1 (type, expr, /*complain=*/true,
5515 /* Build an expression representing an explicit C-style cast to type
5516 TYPE of expression EXPR. */
5519 build_c_cast (tree type, tree expr)
5525 if (type == error_mark_node || error_operand_p (expr))
5526 return error_mark_node;
5528 if (processing_template_decl)
5530 tree t = build_min (CAST_EXPR, type,
5531 tree_cons (NULL_TREE, value, NULL_TREE));
5532 /* We don't know if it will or will not have side effects. */
5533 TREE_SIDE_EFFECTS (t) = 1;
5534 return convert_from_reference (t);
5537 /* Casts to a (pointer to a) specific ObjC class (or 'id' or
5538 'Class') should always be retained, because this information aids
5539 in method lookup. */
5540 if (objc_is_object_ptr (type)
5541 && objc_is_object_ptr (TREE_TYPE (expr)))
5542 return build_nop (type, expr);
5544 /* build_c_cast puts on a NOP_EXPR to make the result not an lvalue.
5545 Strip such NOP_EXPRs if VALUE is being used in non-lvalue context. */
5546 if (TREE_CODE (type) != REFERENCE_TYPE
5547 && TREE_CODE (value) == NOP_EXPR
5548 && TREE_TYPE (value) == TREE_TYPE (TREE_OPERAND (value, 0)))
5549 value = TREE_OPERAND (value, 0);
5551 if (TREE_CODE (type) == ARRAY_TYPE)
5553 /* Allow casting from T1* to T2[] because Cfront allows it.
5554 NIHCL uses it. It is not valid ISO C++ however. */
5555 if (TREE_CODE (TREE_TYPE (expr)) == POINTER_TYPE)
5557 pedwarn ("ISO C++ forbids casting to an array type %qT", type);
5558 type = build_pointer_type (TREE_TYPE (type));
5562 error ("ISO C++ forbids casting to an array type %qT", type);
5563 return error_mark_node;
5567 if (TREE_CODE (type) == FUNCTION_TYPE
5568 || TREE_CODE (type) == METHOD_TYPE)
5570 error ("invalid cast to function type %qT", type);
5571 return error_mark_node;
5574 /* A C-style cast can be a const_cast. */
5575 result = build_const_cast_1 (type, value, /*complain=*/false,
5580 /* Or a static cast. */
5581 result = build_static_cast_1 (type, value, /*c_cast_p=*/true,
5583 /* Or a reinterpret_cast. */
5585 result = build_reinterpret_cast_1 (type, value, /*c_cast_p=*/true,
5587 /* The static_cast or reinterpret_cast may be followed by a
5590 /* A valid cast may result in errors if, for example, a
5591 conversion to am ambiguous base class is required. */
5592 && !error_operand_p (result))
5596 /* Non-class rvalues always have cv-unqualified type. */
5597 if (!CLASS_TYPE_P (type))
5598 type = TYPE_MAIN_VARIANT (type);
5599 result_type = TREE_TYPE (result);
5600 if (!CLASS_TYPE_P (result_type))
5601 result_type = TYPE_MAIN_VARIANT (result_type);
5602 /* If the type of RESULT does not match TYPE, perform a
5603 const_cast to make it match. If the static_cast or
5604 reinterpret_cast succeeded, we will differ by at most
5605 cv-qualification, so the follow-on const_cast is guaranteed
5607 if (!same_type_p (non_reference (type), non_reference (result_type)))
5609 result = build_const_cast_1 (type, result, false, &valid_p);
5610 gcc_assert (valid_p);
5615 return error_mark_node;
5618 /* Build an assignment expression of lvalue LHS from value RHS.
5619 MODIFYCODE is the code for a binary operator that we use
5620 to combine the old value of LHS with RHS to get the new value.
5621 Or else MODIFYCODE is NOP_EXPR meaning do a simple assignment.
5623 C++: If MODIFYCODE is INIT_EXPR, then leave references unbashed. */
5626 build_modify_expr (tree lhs, enum tree_code modifycode, tree rhs)
5630 tree lhstype = TREE_TYPE (lhs);
5631 tree olhstype = lhstype;
5632 tree olhs = NULL_TREE;
5633 bool plain_assign = (modifycode == NOP_EXPR);
5635 /* Avoid duplicate error messages from operands that had errors. */
5636 if (error_operand_p (lhs) || error_operand_p (rhs))
5637 return error_mark_node;
5639 /* Handle control structure constructs used as "lvalues". */
5640 switch (TREE_CODE (lhs))
5642 /* Handle --foo = 5; as these are valid constructs in C++. */
5643 case PREDECREMENT_EXPR:
5644 case PREINCREMENT_EXPR:
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 return build2 (COMPOUND_EXPR, lhstype,
5651 build_modify_expr (TREE_OPERAND (lhs, 0),
5654 /* Handle (a, b) used as an "lvalue". */
5656 newrhs = build_modify_expr (TREE_OPERAND (lhs, 1),
5658 if (newrhs == error_mark_node)
5659 return error_mark_node;
5660 return build2 (COMPOUND_EXPR, lhstype,
5661 TREE_OPERAND (lhs, 0), newrhs);
5664 if (TREE_SIDE_EFFECTS (TREE_OPERAND (lhs, 0)))
5665 lhs = build2 (TREE_CODE (lhs), TREE_TYPE (lhs),
5666 stabilize_reference (TREE_OPERAND (lhs, 0)),
5667 TREE_OPERAND (lhs, 1));
5668 newrhs = build_modify_expr (TREE_OPERAND (lhs, 0), modifycode, rhs);
5669 if (newrhs == error_mark_node)
5670 return error_mark_node;
5671 return build2 (COMPOUND_EXPR, lhstype, lhs, newrhs);
5675 /* MIN_EXPR and MAX_EXPR are currently only permitted as lvalues,
5676 when neither operand has side-effects. */
5677 if (!lvalue_or_else (lhs, lv_assign))
5678 return error_mark_node;
5680 gcc_assert (!TREE_SIDE_EFFECTS (TREE_OPERAND (lhs, 0))
5681 && !TREE_SIDE_EFFECTS (TREE_OPERAND (lhs, 1)));
5683 lhs = build3 (COND_EXPR, TREE_TYPE (lhs),
5684 build2 (TREE_CODE (lhs) == MIN_EXPR ? LE_EXPR : GE_EXPR,
5686 TREE_OPERAND (lhs, 0),
5687 TREE_OPERAND (lhs, 1)),
5688 TREE_OPERAND (lhs, 0),
5689 TREE_OPERAND (lhs, 1));
5692 /* Handle (a ? b : c) used as an "lvalue". */
5695 /* Produce (a ? (b = rhs) : (c = rhs))
5696 except that the RHS goes through a save-expr
5697 so the code to compute it is only emitted once. */
5699 tree preeval = NULL_TREE;
5701 if (VOID_TYPE_P (TREE_TYPE (rhs)))
5703 error ("void value not ignored as it ought to be");
5704 return error_mark_node;
5707 rhs = stabilize_expr (rhs, &preeval);
5709 /* Check this here to avoid odd errors when trying to convert
5710 a throw to the type of the COND_EXPR. */
5711 if (!lvalue_or_else (lhs, lv_assign))
5712 return error_mark_node;
5714 cond = build_conditional_expr
5715 (TREE_OPERAND (lhs, 0),
5716 build_modify_expr (TREE_OPERAND (lhs, 1),
5718 build_modify_expr (TREE_OPERAND (lhs, 2),
5721 if (cond == error_mark_node)
5723 /* Make sure the code to compute the rhs comes out
5724 before the split. */
5726 cond = build2 (COMPOUND_EXPR, TREE_TYPE (lhs), preeval, cond);
5734 if (modifycode == INIT_EXPR)
5736 if (TREE_CODE (rhs) == CONSTRUCTOR)
5738 if (! same_type_p (TREE_TYPE (rhs), lhstype))
5739 /* Call convert to generate an error; see PR 11063. */
5740 rhs = convert (lhstype, rhs);
5741 result = build2 (INIT_EXPR, lhstype, lhs, rhs);
5742 TREE_SIDE_EFFECTS (result) = 1;
5745 else if (! IS_AGGR_TYPE (lhstype))
5746 /* Do the default thing. */;
5749 result = build_special_member_call (lhs, complete_ctor_identifier,
5750 build_tree_list (NULL_TREE, rhs),
5751 lhstype, LOOKUP_NORMAL);
5752 if (result == NULL_TREE)
5753 return error_mark_node;
5759 lhs = require_complete_type (lhs);
5760 if (lhs == error_mark_node)
5761 return error_mark_node;
5763 if (modifycode == NOP_EXPR)
5765 /* `operator=' is not an inheritable operator. */
5766 if (! IS_AGGR_TYPE (lhstype))
5767 /* Do the default thing. */;
5770 result = build_new_op (MODIFY_EXPR, LOOKUP_NORMAL,
5771 lhs, rhs, make_node (NOP_EXPR),
5772 /*overloaded_p=*/NULL);
5773 if (result == NULL_TREE)
5774 return error_mark_node;
5781 /* A binary op has been requested. Combine the old LHS
5782 value with the RHS producing the value we should actually
5783 store into the LHS. */
5785 gcc_assert (!PROMOTES_TO_AGGR_TYPE (lhstype, REFERENCE_TYPE));
5786 lhs = stabilize_reference (lhs);
5787 newrhs = cp_build_binary_op (modifycode, lhs, rhs);
5788 if (newrhs == error_mark_node)
5790 error (" in evaluation of %<%Q(%#T, %#T)%>", modifycode,
5791 TREE_TYPE (lhs), TREE_TYPE (rhs));
5792 return error_mark_node;
5795 /* Now it looks like a plain assignment. */
5796 modifycode = NOP_EXPR;
5798 gcc_assert (TREE_CODE (lhstype) != REFERENCE_TYPE);
5799 gcc_assert (TREE_CODE (TREE_TYPE (newrhs)) != REFERENCE_TYPE);
5802 /* The left-hand side must be an lvalue. */
5803 if (!lvalue_or_else (lhs, lv_assign))
5804 return error_mark_node;
5806 /* Warn about modifying something that is `const'. Don't warn if
5807 this is initialization. */
5808 if (modifycode != INIT_EXPR
5809 && (TREE_READONLY (lhs) || CP_TYPE_CONST_P (lhstype)
5810 /* Functions are not modifiable, even though they are
5812 || TREE_CODE (TREE_TYPE (lhs)) == FUNCTION_TYPE
5813 || TREE_CODE (TREE_TYPE (lhs)) == METHOD_TYPE
5814 /* If it's an aggregate and any field is const, then it is
5815 effectively const. */
5816 || (CLASS_TYPE_P (lhstype)
5817 && C_TYPE_FIELDS_READONLY (lhstype))))
5818 readonly_error (lhs, "assignment");
5820 /* If storing into a structure or union member, it has probably been
5821 given type `int'. Compute the type that would go with the actual
5822 amount of storage the member occupies. */
5824 if (TREE_CODE (lhs) == COMPONENT_REF
5825 && (TREE_CODE (lhstype) == INTEGER_TYPE
5826 || TREE_CODE (lhstype) == REAL_TYPE
5827 || TREE_CODE (lhstype) == ENUMERAL_TYPE))
5829 lhstype = TREE_TYPE (get_unwidened (lhs, 0));
5831 /* If storing in a field that is in actuality a short or narrower
5832 than one, we must store in the field in its actual type. */
5834 if (lhstype != TREE_TYPE (lhs))
5836 /* Avoid warnings converting integral types back into enums for
5838 if (TREE_CODE (lhstype) == INTEGER_TYPE
5839 && TREE_CODE (olhstype) == ENUMERAL_TYPE)
5841 if (TREE_SIDE_EFFECTS (lhs))
5842 lhs = stabilize_reference (lhs);
5845 lhs = copy_node (lhs);
5846 TREE_TYPE (lhs) = lhstype;
5850 /* Convert new value to destination type. */
5852 if (TREE_CODE (lhstype) == ARRAY_TYPE)
5856 if (!same_or_base_type_p (TYPE_MAIN_VARIANT (lhstype),
5857 TYPE_MAIN_VARIANT (TREE_TYPE (rhs))))
5859 error ("incompatible types in assignment of %qT to %qT",
5860 TREE_TYPE (rhs), lhstype);
5861 return error_mark_node;
5864 /* Allow array assignment in compiler-generated code. */
5865 if (! DECL_ARTIFICIAL (current_function_decl))
5867 /* This routine is used for both initialization and assignment.
5868 Make sure the diagnostic message differentiates the context. */
5869 if (modifycode == INIT_EXPR)
5870 error ("array used as initializer");
5872 error ("invalid array assignment");
5873 return error_mark_node;
5876 from_array = TREE_CODE (TREE_TYPE (newrhs)) == ARRAY_TYPE
5877 ? 1 + (modifycode != INIT_EXPR): 0;
5878 return build_vec_init (lhs, NULL_TREE, newrhs,
5879 /*explicit_default_init_p=*/false,
5883 if (modifycode == INIT_EXPR)
5884 newrhs = convert_for_initialization (lhs, lhstype, newrhs, LOOKUP_NORMAL,
5885 "initialization", NULL_TREE, 0);
5888 /* Avoid warnings on enum bit fields. */
5889 if (TREE_CODE (olhstype) == ENUMERAL_TYPE
5890 && TREE_CODE (lhstype) == INTEGER_TYPE)
5892 newrhs = convert_for_assignment (olhstype, newrhs, "assignment",
5894 newrhs = convert_force (lhstype, newrhs, 0);
5897 newrhs = convert_for_assignment (lhstype, newrhs, "assignment",
5899 if (TREE_CODE (newrhs) == CALL_EXPR
5900 && TYPE_NEEDS_CONSTRUCTING (lhstype))
5901 newrhs = build_cplus_new (lhstype, newrhs);
5903 /* Can't initialize directly from a TARGET_EXPR, since that would
5904 cause the lhs to be constructed twice, and possibly result in
5905 accidental self-initialization. So we force the TARGET_EXPR to be
5906 expanded without a target. */
5907 if (TREE_CODE (newrhs) == TARGET_EXPR)
5908 newrhs = build2 (COMPOUND_EXPR, TREE_TYPE (newrhs), newrhs,
5909 TREE_OPERAND (newrhs, 0));
5912 if (newrhs == error_mark_node)
5913 return error_mark_node;
5915 if (c_dialect_objc () && flag_objc_gc)
5917 result = objc_generate_write_barrier (lhs, modifycode, newrhs);
5923 result = build2 (modifycode == NOP_EXPR ? MODIFY_EXPR : INIT_EXPR,
5924 lhstype, lhs, newrhs);
5926 TREE_SIDE_EFFECTS (result) = 1;
5928 TREE_NO_WARNING (result) = 1;
5930 /* If we got the LHS in a different type for storing in,
5931 convert the result back to the nominal type of LHS
5932 so that the value we return always has the same type
5933 as the LHS argument. */
5935 if (olhstype == TREE_TYPE (result))
5939 result = build2 (COMPOUND_EXPR, olhstype, result, olhs);
5940 TREE_NO_WARNING (result) = 1;
5943 return convert_for_assignment (olhstype, result, "assignment",
5948 build_x_modify_expr (tree lhs, enum tree_code modifycode, tree rhs)
5950 if (processing_template_decl)
5951 return build_min_nt (MODOP_EXPR, lhs,
5952 build_min_nt (modifycode, NULL_TREE, NULL_TREE), rhs);
5954 if (modifycode != NOP_EXPR)
5956 tree rval = build_new_op (MODIFY_EXPR, LOOKUP_NORMAL, lhs, rhs,
5957 make_node (modifycode),
5958 /*overloaded_p=*/NULL);
5961 TREE_NO_WARNING (rval) = 1;
5965 return build_modify_expr (lhs, modifycode, rhs);
5969 /* Get difference in deltas for different pointer to member function
5970 types. Returns an integer constant of type PTRDIFF_TYPE_NODE. If
5971 the conversion is invalid, the constant is zero. If
5972 ALLOW_INVERSE_P is true, then allow reverse conversions as well.
5973 If C_CAST_P is true this conversion is taking place as part of a
5976 Note that the naming of FROM and TO is kind of backwards; the return
5977 value is what we add to a TO in order to get a FROM. They are named
5978 this way because we call this function to find out how to convert from
5979 a pointer to member of FROM to a pointer to member of TO. */
5982 get_delta_difference (tree from, tree to,
5983 bool allow_inverse_p,
5990 /* Assume no conversion is required. */
5991 result = integer_zero_node;
5992 binfo = lookup_base (to, from, c_cast_p ? ba_unique : ba_check, &kind);
5993 if (kind == bk_inaccessible || kind == bk_ambig)
5994 error (" in pointer to member function conversion");
5997 if (kind != bk_via_virtual)
5998 result = BINFO_OFFSET (binfo);
6001 tree virt_binfo = binfo_from_vbase (binfo);
6003 /* This is a reinterpret cast, we choose to do nothing. */
6004 if (allow_inverse_p)
6005 warning (0, "pointer to member cast via virtual base %qT",
6006 BINFO_TYPE (virt_binfo));
6008 error ("pointer to member conversion via virtual base %qT",
6009 BINFO_TYPE (virt_binfo));
6012 else if (same_type_ignoring_top_level_qualifiers_p (from, to))
6013 /* Pointer to member of incomplete class is permitted*/;
6014 else if (!allow_inverse_p)
6016 error_not_base_type (from, to);
6017 error (" in pointer to member conversion");
6021 binfo = lookup_base (from, to, c_cast_p ? ba_unique : ba_check, &kind);
6024 if (kind != bk_via_virtual)
6025 result = size_diffop (size_zero_node, BINFO_OFFSET (binfo));
6028 /* This is a reinterpret cast, we choose to do nothing. */
6029 tree virt_binfo = binfo_from_vbase (binfo);
6031 warning (0, "pointer to member cast via virtual base %qT",
6032 BINFO_TYPE (virt_binfo));
6037 return fold_if_not_in_template (convert_to_integer (ptrdiff_type_node,
6041 /* Return a constructor for the pointer-to-member-function TYPE using
6042 the other components as specified. */
6045 build_ptrmemfunc1 (tree type, tree delta, tree pfn)
6050 VEC(constructor_elt, gc) *v;
6052 /* Pull the FIELD_DECLs out of the type. */
6053 pfn_field = TYPE_FIELDS (type);
6054 delta_field = TREE_CHAIN (pfn_field);
6056 /* Make sure DELTA has the type we want. */
6057 delta = convert_and_check (delta_type_node, delta);
6059 /* Finish creating the initializer. */
6060 v = VEC_alloc(constructor_elt, gc, 2);
6061 CONSTRUCTOR_APPEND_ELT(v, pfn_field, pfn);
6062 CONSTRUCTOR_APPEND_ELT(v, delta_field, delta);
6063 u = build_constructor (type, v);
6064 TREE_CONSTANT (u) = TREE_CONSTANT (pfn) & TREE_CONSTANT (delta);
6065 TREE_INVARIANT (u) = TREE_INVARIANT (pfn) & TREE_INVARIANT (delta);
6066 TREE_STATIC (u) = (TREE_CONSTANT (u)
6067 && (initializer_constant_valid_p (pfn, TREE_TYPE (pfn))
6069 && (initializer_constant_valid_p (delta, TREE_TYPE (delta))
6074 /* Build a constructor for a pointer to member function. It can be
6075 used to initialize global variables, local variable, or used
6076 as a value in expressions. TYPE is the POINTER to METHOD_TYPE we
6079 If FORCE is nonzero, then force this conversion, even if
6080 we would rather not do it. Usually set when using an explicit
6081 cast. A C-style cast is being processed iff C_CAST_P is true.
6083 Return error_mark_node, if something goes wrong. */
6086 build_ptrmemfunc (tree type, tree pfn, int force, bool c_cast_p)
6092 if (error_operand_p (pfn))
6093 return error_mark_node;
6095 pfn_type = TREE_TYPE (pfn);
6096 to_type = build_ptrmemfunc_type (type);
6098 /* Handle multiple conversions of pointer to member functions. */
6099 if (TYPE_PTRMEMFUNC_P (pfn_type))
6101 tree delta = NULL_TREE;
6102 tree npfn = NULL_TREE;
6106 && !can_convert_arg (to_type, TREE_TYPE (pfn), pfn, LOOKUP_NORMAL))
6107 error ("invalid conversion to type %qT from type %qT",
6110 n = get_delta_difference (TYPE_PTRMEMFUNC_OBJECT_TYPE (pfn_type),
6111 TYPE_PTRMEMFUNC_OBJECT_TYPE (to_type),
6115 /* We don't have to do any conversion to convert a
6116 pointer-to-member to its own type. But, we don't want to
6117 just return a PTRMEM_CST if there's an explicit cast; that
6118 cast should make the expression an invalid template argument. */
6119 if (TREE_CODE (pfn) != PTRMEM_CST)
6121 if (same_type_p (to_type, pfn_type))
6123 else if (integer_zerop (n))
6124 return build_reinterpret_cast (to_type, pfn);
6127 if (TREE_SIDE_EFFECTS (pfn))
6128 pfn = save_expr (pfn);
6130 /* Obtain the function pointer and the current DELTA. */
6131 if (TREE_CODE (pfn) == PTRMEM_CST)
6132 expand_ptrmemfunc_cst (pfn, &delta, &npfn);
6135 npfn = build_ptrmemfunc_access_expr (pfn, pfn_identifier);
6136 delta = build_ptrmemfunc_access_expr (pfn, delta_identifier);
6139 /* Just adjust the DELTA field. */
6140 gcc_assert (same_type_ignoring_top_level_qualifiers_p
6141 (TREE_TYPE (delta), ptrdiff_type_node));
6142 if (TARGET_PTRMEMFUNC_VBIT_LOCATION == ptrmemfunc_vbit_in_delta)
6143 n = cp_build_binary_op (LSHIFT_EXPR, n, integer_one_node);
6144 delta = cp_build_binary_op (PLUS_EXPR, delta, n);
6145 return build_ptrmemfunc1 (to_type, delta, npfn);
6148 /* Handle null pointer to member function conversions. */
6149 if (integer_zerop (pfn))
6151 pfn = build_c_cast (type, integer_zero_node);
6152 return build_ptrmemfunc1 (to_type,
6157 if (type_unknown_p (pfn))
6158 return instantiate_type (type, pfn, tf_warning_or_error);
6160 fn = TREE_OPERAND (pfn, 0);
6161 gcc_assert (TREE_CODE (fn) == FUNCTION_DECL
6162 /* In a template, we will have preserved the
6164 || (processing_template_decl && TREE_CODE (fn) == OFFSET_REF));
6165 return make_ptrmem_cst (to_type, fn);
6168 /* Return the DELTA, IDX, PFN, and DELTA2 values for the PTRMEM_CST
6171 ??? There is no consistency as to the types returned for the above
6172 values. Some code acts as if it were a sizetype and some as if it were
6173 integer_type_node. */
6176 expand_ptrmemfunc_cst (tree cst, tree *delta, tree *pfn)
6178 tree type = TREE_TYPE (cst);
6179 tree fn = PTRMEM_CST_MEMBER (cst);
6180 tree ptr_class, fn_class;
6182 gcc_assert (TREE_CODE (fn) == FUNCTION_DECL);
6184 /* The class that the function belongs to. */
6185 fn_class = DECL_CONTEXT (fn);
6187 /* The class that we're creating a pointer to member of. */
6188 ptr_class = TYPE_PTRMEMFUNC_OBJECT_TYPE (type);
6190 /* First, calculate the adjustment to the function's class. */
6191 *delta = get_delta_difference (fn_class, ptr_class, /*force=*/0,
6194 if (!DECL_VIRTUAL_P (fn))
6195 *pfn = convert (TYPE_PTRMEMFUNC_FN_TYPE (type), build_addr_func (fn));
6198 /* If we're dealing with a virtual function, we have to adjust 'this'
6199 again, to point to the base which provides the vtable entry for
6200 fn; the call will do the opposite adjustment. */
6201 tree orig_class = DECL_CONTEXT (fn);
6202 tree binfo = binfo_or_else (orig_class, fn_class);
6203 *delta = build2 (PLUS_EXPR, TREE_TYPE (*delta),
6204 *delta, BINFO_OFFSET (binfo));
6205 *delta = fold_if_not_in_template (*delta);
6207 /* We set PFN to the vtable offset at which the function can be
6208 found, plus one (unless ptrmemfunc_vbit_in_delta, in which
6209 case delta is shifted left, and then incremented). */
6210 *pfn = DECL_VINDEX (fn);
6211 *pfn = build2 (MULT_EXPR, integer_type_node, *pfn,
6212 TYPE_SIZE_UNIT (vtable_entry_type));
6213 *pfn = fold_if_not_in_template (*pfn);
6215 switch (TARGET_PTRMEMFUNC_VBIT_LOCATION)
6217 case ptrmemfunc_vbit_in_pfn:
6218 *pfn = build2 (PLUS_EXPR, integer_type_node, *pfn,
6220 *pfn = fold_if_not_in_template (*pfn);
6223 case ptrmemfunc_vbit_in_delta:
6224 *delta = build2 (LSHIFT_EXPR, TREE_TYPE (*delta),
6225 *delta, integer_one_node);
6226 *delta = fold_if_not_in_template (*delta);
6227 *delta = build2 (PLUS_EXPR, TREE_TYPE (*delta),
6228 *delta, integer_one_node);
6229 *delta = fold_if_not_in_template (*delta);
6236 *pfn = build_nop (TYPE_PTRMEMFUNC_FN_TYPE (type), *pfn);
6237 *pfn = fold_if_not_in_template (*pfn);
6241 /* Return an expression for PFN from the pointer-to-member function
6245 pfn_from_ptrmemfunc (tree t)
6247 if (TREE_CODE (t) == PTRMEM_CST)
6252 expand_ptrmemfunc_cst (t, &delta, &pfn);
6257 return build_ptrmemfunc_access_expr (t, pfn_identifier);
6260 /* Convert value RHS to type TYPE as preparation for an assignment to
6261 an lvalue of type TYPE. ERRTYPE is a string to use in error
6262 messages: "assignment", "return", etc. If FNDECL is non-NULL, we
6263 are doing the conversion in order to pass the PARMNUMth argument of
6267 convert_for_assignment (tree type, tree rhs,
6268 const char *errtype, tree fndecl, int parmnum)
6271 enum tree_code coder;
6273 /* Strip NON_LVALUE_EXPRs since we aren't using as an lvalue. */
6274 if (TREE_CODE (rhs) == NON_LVALUE_EXPR)
6275 rhs = TREE_OPERAND (rhs, 0);
6277 rhstype = TREE_TYPE (rhs);
6278 coder = TREE_CODE (rhstype);
6280 if (TREE_CODE (type) == VECTOR_TYPE && coder == VECTOR_TYPE
6281 && vector_types_convertible_p (type, rhstype, true))
6282 return convert (type, rhs);
6284 if (rhs == error_mark_node || rhstype == error_mark_node)
6285 return error_mark_node;
6286 if (TREE_CODE (rhs) == TREE_LIST && TREE_VALUE (rhs) == error_mark_node)
6287 return error_mark_node;
6289 /* The RHS of an assignment cannot have void type. */
6290 if (coder == VOID_TYPE)
6292 error ("void value not ignored as it ought to be");
6293 return error_mark_node;
6296 /* Simplify the RHS if possible. */
6297 if (TREE_CODE (rhs) == CONST_DECL)
6298 rhs = DECL_INITIAL (rhs);
6300 if (c_dialect_objc ())
6303 tree rname = fndecl;
6305 if (!strcmp (errtype, "assignment"))
6307 else if (!strcmp (errtype, "initialization"))
6311 tree selector = objc_message_selector ();
6315 if (selector && parmno > 1)
6322 if (objc_compare_types (type, rhstype, parmno, rname))
6323 return convert (type, rhs);
6328 The expression is implicitly converted (clause _conv_) to the
6329 cv-unqualified type of the left operand.
6331 We allow bad conversions here because by the time we get to this point
6332 we are committed to doing the conversion. If we end up doing a bad
6333 conversion, convert_like will complain. */
6334 if (!can_convert_arg_bad (type, rhstype, rhs))
6336 /* When -Wno-pmf-conversions is use, we just silently allow
6337 conversions from pointers-to-members to plain pointers. If
6338 the conversion doesn't work, cp_convert will complain. */
6340 && TYPE_PTR_P (type)
6341 && TYPE_PTRMEMFUNC_P (rhstype))
6342 rhs = cp_convert (strip_top_quals (type), rhs);
6345 /* If the right-hand side has unknown type, then it is an
6346 overloaded function. Call instantiate_type to get error
6348 if (rhstype == unknown_type_node)
6349 instantiate_type (type, rhs, tf_warning_or_error);
6351 error ("cannot convert %qT to %qT for argument %qP to %qD",
6352 rhstype, type, parmnum, fndecl);
6354 error ("cannot convert %qT to %qT in %s", rhstype, type, errtype);
6355 return error_mark_node;
6358 if (warn_missing_format_attribute)
6360 const enum tree_code codel = TREE_CODE (type);
6361 if ((codel == POINTER_TYPE || codel == REFERENCE_TYPE)
6363 && check_missing_format_attribute (type, rhstype))
6364 warning (OPT_Wmissing_format_attribute,
6365 "%s might be a candidate for a format attribute",
6369 /* If -Wparentheses, warn about a = b = c when a has type bool and b
6371 if (warn_parentheses
6372 && type == boolean_type_node
6373 && TREE_CODE (rhs) == MODIFY_EXPR
6374 && !TREE_NO_WARNING (rhs)
6375 && TREE_TYPE (rhs) != boolean_type_node)
6377 warning (OPT_Wparentheses,
6378 "suggest parentheses around assignment used as truth value");
6379 TREE_NO_WARNING (rhs) = 1;
6382 return perform_implicit_conversion (strip_top_quals (type), rhs);
6385 /* Convert RHS to be of type TYPE.
6386 If EXP is nonzero, it is the target of the initialization.
6387 ERRTYPE is a string to use in error messages.
6389 Two major differences between the behavior of
6390 `convert_for_assignment' and `convert_for_initialization'
6391 are that references are bashed in the former, while
6392 copied in the latter, and aggregates are assigned in
6393 the former (operator=) while initialized in the
6396 If using constructor make sure no conversion operator exists, if one does
6397 exist, an ambiguity exists.
6399 If flags doesn't include LOOKUP_COMPLAIN, don't complain about anything. */
6402 convert_for_initialization (tree exp, tree type, tree rhs, int flags,
6403 const char *errtype, tree fndecl, int parmnum)
6405 enum tree_code codel = TREE_CODE (type);
6407 enum tree_code coder;
6409 /* build_c_cast puts on a NOP_EXPR to make the result not an lvalue.
6410 Strip such NOP_EXPRs, since RHS is used in non-lvalue context. */
6411 if (TREE_CODE (rhs) == NOP_EXPR
6412 && TREE_TYPE (rhs) == TREE_TYPE (TREE_OPERAND (rhs, 0))
6413 && codel != REFERENCE_TYPE)
6414 rhs = TREE_OPERAND (rhs, 0);
6416 if (type == error_mark_node
6417 || rhs == error_mark_node
6418 || (TREE_CODE (rhs) == TREE_LIST && TREE_VALUE (rhs) == error_mark_node))
6419 return error_mark_node;
6421 if ((TREE_CODE (TREE_TYPE (rhs)) == ARRAY_TYPE
6422 && TREE_CODE (type) != ARRAY_TYPE
6423 && (TREE_CODE (type) != REFERENCE_TYPE
6424 || TREE_CODE (TREE_TYPE (type)) != ARRAY_TYPE))
6425 || (TREE_CODE (TREE_TYPE (rhs)) == FUNCTION_TYPE
6426 && (TREE_CODE (type) != REFERENCE_TYPE
6427 || TREE_CODE (TREE_TYPE (type)) != FUNCTION_TYPE))
6428 || TREE_CODE (TREE_TYPE (rhs)) == METHOD_TYPE)
6429 rhs = decay_conversion (rhs);
6431 rhstype = TREE_TYPE (rhs);
6432 coder = TREE_CODE (rhstype);
6434 if (coder == ERROR_MARK)
6435 return error_mark_node;
6437 /* We accept references to incomplete types, so we can
6438 return here before checking if RHS is of complete type. */
6440 if (codel == REFERENCE_TYPE)
6442 /* This should eventually happen in convert_arguments. */
6443 int savew = 0, savee = 0;
6446 savew = warningcount, savee = errorcount;
6447 rhs = initialize_reference (type, rhs, /*decl=*/NULL_TREE,
6451 if (warningcount > savew)
6452 warning (0, "in passing argument %P of %q+D", parmnum, fndecl);
6453 else if (errorcount > savee)
6454 error ("in passing argument %P of %q+D", parmnum, fndecl);
6460 exp = require_complete_type (exp);
6461 if (exp == error_mark_node)
6462 return error_mark_node;
6464 rhstype = non_reference (rhstype);
6466 type = complete_type (type);
6468 if (IS_AGGR_TYPE (type))
6469 return ocp_convert (type, rhs, CONV_IMPLICIT|CONV_FORCE_TEMP, flags);
6471 return convert_for_assignment (type, rhs, errtype, fndecl, parmnum);
6474 /* If RETVAL is the address of, or a reference to, a local variable or
6475 temporary give an appropriate warning. */
6478 maybe_warn_about_returning_address_of_local (tree retval)
6480 tree valtype = TREE_TYPE (DECL_RESULT (current_function_decl));
6481 tree whats_returned = retval;
6485 if (TREE_CODE (whats_returned) == COMPOUND_EXPR)
6486 whats_returned = TREE_OPERAND (whats_returned, 1);
6487 else if (TREE_CODE (whats_returned) == CONVERT_EXPR
6488 || TREE_CODE (whats_returned) == NON_LVALUE_EXPR
6489 || TREE_CODE (whats_returned) == NOP_EXPR)
6490 whats_returned = TREE_OPERAND (whats_returned, 0);
6495 if (TREE_CODE (whats_returned) != ADDR_EXPR)
6497 whats_returned = TREE_OPERAND (whats_returned, 0);
6499 if (TREE_CODE (valtype) == REFERENCE_TYPE)
6501 if (TREE_CODE (whats_returned) == AGGR_INIT_EXPR
6502 || TREE_CODE (whats_returned) == TARGET_EXPR)
6504 warning (0, "returning reference to temporary");
6507 if (TREE_CODE (whats_returned) == VAR_DECL
6508 && DECL_NAME (whats_returned)
6509 && TEMP_NAME_P (DECL_NAME (whats_returned)))
6511 warning (0, "reference to non-lvalue returned");
6516 while (TREE_CODE (whats_returned) == COMPONENT_REF
6517 || TREE_CODE (whats_returned) == ARRAY_REF)
6518 whats_returned = TREE_OPERAND (whats_returned, 0);
6520 if (DECL_P (whats_returned)
6521 && DECL_NAME (whats_returned)
6522 && DECL_FUNCTION_SCOPE_P (whats_returned)
6523 && !(TREE_STATIC (whats_returned)
6524 || TREE_PUBLIC (whats_returned)))
6526 if (TREE_CODE (valtype) == REFERENCE_TYPE)
6527 warning (0, "reference to local variable %q+D returned",
6530 warning (0, "address of local variable %q+D returned",
6536 /* Check that returning RETVAL from the current function is valid.
6537 Return an expression explicitly showing all conversions required to
6538 change RETVAL into the function return type, and to assign it to
6539 the DECL_RESULT for the function. Set *NO_WARNING to true if
6540 code reaches end of non-void function warning shouldn't be issued
6541 on this RETURN_EXPR. */
6544 check_return_expr (tree retval, bool *no_warning)
6547 /* The type actually returned by the function, after any
6550 int fn_returns_value_p;
6551 bool named_return_value_okay_p;
6553 *no_warning = false;
6555 /* A `volatile' function is one that isn't supposed to return, ever.
6556 (This is a G++ extension, used to get better code for functions
6557 that call the `volatile' function.) */
6558 if (TREE_THIS_VOLATILE (current_function_decl))
6559 warning (0, "function declared %<noreturn%> has a %<return%> statement");
6561 /* Check for various simple errors. */
6562 if (DECL_DESTRUCTOR_P (current_function_decl))
6565 error ("returning a value from a destructor");
6568 else if (DECL_CONSTRUCTOR_P (current_function_decl))
6570 if (in_function_try_handler)
6571 /* If a return statement appears in a handler of the
6572 function-try-block of a constructor, the program is ill-formed. */
6573 error ("cannot return from a handler of a function-try-block of a constructor");
6575 /* You can't return a value from a constructor. */
6576 error ("returning a value from a constructor");
6580 if (processing_template_decl)
6582 current_function_returns_value = 1;
6583 check_for_bare_parameter_packs (retval);
6587 /* When no explicit return-value is given in a function with a named
6588 return value, the named return value is used. */
6589 result = DECL_RESULT (current_function_decl);
6590 valtype = TREE_TYPE (result);
6591 gcc_assert (valtype != NULL_TREE);
6592 fn_returns_value_p = !VOID_TYPE_P (valtype);
6593 if (!retval && DECL_NAME (result) && fn_returns_value_p)
6596 /* Check for a return statement with no return value in a function
6597 that's supposed to return a value. */
6598 if (!retval && fn_returns_value_p)
6600 pedwarn ("return-statement with no value, in function returning %qT",
6602 /* Clear this, so finish_function won't say that we reach the
6603 end of a non-void function (which we don't, we gave a
6605 current_function_returns_null = 0;
6606 /* And signal caller that TREE_NO_WARNING should be set on the
6607 RETURN_EXPR to avoid control reaches end of non-void function
6608 warnings in tree-cfg.c. */
6611 /* Check for a return statement with a value in a function that
6612 isn't supposed to return a value. */
6613 else if (retval && !fn_returns_value_p)
6615 if (VOID_TYPE_P (TREE_TYPE (retval)))
6616 /* You can return a `void' value from a function of `void'
6617 type. In that case, we have to evaluate the expression for
6618 its side-effects. */
6619 finish_expr_stmt (retval);
6621 pedwarn ("return-statement with a value, in function "
6622 "returning 'void'");
6624 current_function_returns_null = 1;
6626 /* There's really no value to return, after all. */
6630 /* Remember that this function can sometimes return without a
6632 current_function_returns_null = 1;
6634 /* Remember that this function did return a value. */
6635 current_function_returns_value = 1;
6637 /* Check for erroneous operands -- but after giving ourselves a
6638 chance to provide an error about returning a value from a void
6640 if (error_operand_p (retval))
6642 current_function_return_value = error_mark_node;
6643 return error_mark_node;
6646 /* Only operator new(...) throw(), can return NULL [expr.new/13]. */
6647 if ((DECL_OVERLOADED_OPERATOR_P (current_function_decl) == NEW_EXPR
6648 || DECL_OVERLOADED_OPERATOR_P (current_function_decl) == VEC_NEW_EXPR)
6649 && !TYPE_NOTHROW_P (TREE_TYPE (current_function_decl))
6651 && retval && null_ptr_cst_p (retval))
6652 warning (0, "%<operator new%> must not return NULL unless it is "
6653 "declared %<throw()%> (or -fcheck-new is in effect)");
6655 /* Effective C++ rule 15. See also start_function. */
6657 && DECL_NAME (current_function_decl) == ansi_assopname(NOP_EXPR))
6661 /* The function return type must be a reference to the current
6663 if (TREE_CODE (valtype) == REFERENCE_TYPE
6664 && same_type_ignoring_top_level_qualifiers_p
6665 (TREE_TYPE (valtype), TREE_TYPE (current_class_ref)))
6667 /* Returning '*this' is obviously OK. */
6668 if (retval == current_class_ref)
6670 /* If we are calling a function whose return type is the same of
6671 the current class reference, it is ok. */
6672 else if (TREE_CODE (retval) == INDIRECT_REF
6673 && TREE_CODE (TREE_OPERAND (retval, 0)) == CALL_EXPR)
6678 warning (OPT_Weffc__, "%<operator=%> should return a reference to %<*this%>");
6681 /* The fabled Named Return Value optimization, as per [class.copy]/15:
6683 [...] For a function with a class return type, if the expression
6684 in the return statement is the name of a local object, and the cv-
6685 unqualified type of the local object is the same as the function
6686 return type, an implementation is permitted to omit creating the tem-
6687 porary object to hold the function return value [...]
6689 So, if this is a value-returning function that always returns the same
6690 local variable, remember it.
6692 It might be nice to be more flexible, and choose the first suitable
6693 variable even if the function sometimes returns something else, but
6694 then we run the risk of clobbering the variable we chose if the other
6695 returned expression uses the chosen variable somehow. And people expect
6696 this restriction, anyway. (jason 2000-11-19)
6698 See finish_function and finalize_nrv for the rest of this optimization. */
6700 named_return_value_okay_p =
6701 (retval != NULL_TREE
6702 /* Must be a local, automatic variable. */
6703 && TREE_CODE (retval) == VAR_DECL
6704 && DECL_CONTEXT (retval) == current_function_decl
6705 && ! TREE_STATIC (retval)
6706 && ! DECL_ANON_UNION_VAR_P (retval)
6707 && (DECL_ALIGN (retval)
6708 >= DECL_ALIGN (DECL_RESULT (current_function_decl)))
6709 /* The cv-unqualified type of the returned value must be the
6710 same as the cv-unqualified return type of the
6712 && same_type_p ((TYPE_MAIN_VARIANT (TREE_TYPE (retval))),
6714 (TREE_TYPE (TREE_TYPE (current_function_decl))))));
6716 if (fn_returns_value_p && flag_elide_constructors)
6718 if (named_return_value_okay_p
6719 && (current_function_return_value == NULL_TREE
6720 || current_function_return_value == retval))
6721 current_function_return_value = retval;
6723 current_function_return_value = error_mark_node;
6726 /* We don't need to do any conversions when there's nothing being
6731 /* Do any required conversions. */
6732 if (retval == result || DECL_CONSTRUCTOR_P (current_function_decl))
6733 /* No conversions are required. */
6737 /* The type the function is declared to return. */
6738 tree functype = TREE_TYPE (TREE_TYPE (current_function_decl));
6739 int flags = LOOKUP_NORMAL | LOOKUP_ONLYCONVERTING;
6741 /* The functype's return type will have been set to void, if it
6742 was an incomplete type. Just treat this as 'return;' */
6743 if (VOID_TYPE_P (functype))
6744 return error_mark_node;
6746 /* Under C++0x [12.8/16 class.copy], a returned lvalue is sometimes
6747 treated as an rvalue for the purposes of overload resolution to
6748 favor move constructors over copy constructors. */
6749 if ((cxx_dialect != cxx98)
6750 && named_return_value_okay_p
6751 /* The variable must not have the `volatile' qualifier. */
6752 && !(cp_type_quals (TREE_TYPE (retval)) & TYPE_QUAL_VOLATILE)
6753 /* The return type must be a class type. */
6754 && CLASS_TYPE_P (TREE_TYPE (TREE_TYPE (current_function_decl))))
6755 flags = flags | LOOKUP_PREFER_RVALUE;
6757 /* First convert the value to the function's return type, then
6758 to the type of return value's location to handle the
6759 case that functype is smaller than the valtype. */
6760 retval = convert_for_initialization
6761 (NULL_TREE, functype, retval, flags, "return", NULL_TREE, 0);
6762 retval = convert (valtype, retval);
6764 /* If the conversion failed, treat this just like `return;'. */
6765 if (retval == error_mark_node)
6767 /* We can't initialize a register from a AGGR_INIT_EXPR. */
6768 else if (! current_function_returns_struct
6769 && TREE_CODE (retval) == TARGET_EXPR
6770 && TREE_CODE (TREE_OPERAND (retval, 1)) == AGGR_INIT_EXPR)
6771 retval = build2 (COMPOUND_EXPR, TREE_TYPE (retval), retval,
6772 TREE_OPERAND (retval, 0));
6774 maybe_warn_about_returning_address_of_local (retval);
6777 /* Actually copy the value returned into the appropriate location. */
6778 if (retval && retval != result)
6779 retval = build2 (INIT_EXPR, TREE_TYPE (result), result, retval);
6785 /* Returns nonzero if the pointer-type FROM can be converted to the
6786 pointer-type TO via a qualification conversion. If CONSTP is -1,
6787 then we return nonzero if the pointers are similar, and the
6788 cv-qualification signature of FROM is a proper subset of that of TO.
6790 If CONSTP is positive, then all outer pointers have been
6794 comp_ptr_ttypes_real (tree to, tree from, int constp)
6796 bool to_more_cv_qualified = false;
6798 for (; ; to = TREE_TYPE (to), from = TREE_TYPE (from))
6800 if (TREE_CODE (to) != TREE_CODE (from))
6803 if (TREE_CODE (from) == OFFSET_TYPE
6804 && !same_type_p (TYPE_OFFSET_BASETYPE (from),
6805 TYPE_OFFSET_BASETYPE (to)))
6808 /* Const and volatile mean something different for function types,
6809 so the usual checks are not appropriate. */
6810 if (TREE_CODE (to) != FUNCTION_TYPE && TREE_CODE (to) != METHOD_TYPE)
6812 /* In Objective-C++, some types may have been 'volatilized' by
6813 the compiler for EH; when comparing them here, the volatile
6814 qualification must be ignored. */
6815 bool objc_quals_match = objc_type_quals_match (to, from);
6817 if (!at_least_as_qualified_p (to, from) && !objc_quals_match)
6820 if (!at_least_as_qualified_p (from, to) && !objc_quals_match)
6824 to_more_cv_qualified = true;
6828 constp &= TYPE_READONLY (to);
6831 if (TREE_CODE (to) != POINTER_TYPE && !TYPE_PTRMEM_P (to))
6832 return ((constp >= 0 || to_more_cv_qualified)
6833 && same_type_ignoring_top_level_qualifiers_p (to, from));
6837 /* When comparing, say, char ** to char const **, this function takes
6838 the 'char *' and 'char const *'. Do not pass non-pointer/reference
6839 types to this function. */
6842 comp_ptr_ttypes (tree to, tree from)
6844 return comp_ptr_ttypes_real (to, from, 1);
6847 /* Returns 1 if to and from are (possibly multi-level) pointers to the same
6848 type or inheritance-related types, regardless of cv-quals. */
6851 ptr_reasonably_similar (tree to, tree from)
6853 for (; ; to = TREE_TYPE (to), from = TREE_TYPE (from))
6855 /* Any target type is similar enough to void. */
6856 if (TREE_CODE (to) == VOID_TYPE
6857 || TREE_CODE (from) == VOID_TYPE)
6860 if (TREE_CODE (to) != TREE_CODE (from))
6863 if (TREE_CODE (from) == OFFSET_TYPE
6864 && comptypes (TYPE_OFFSET_BASETYPE (to),
6865 TYPE_OFFSET_BASETYPE (from),
6866 COMPARE_BASE | COMPARE_DERIVED))
6869 if (TREE_CODE (to) == VECTOR_TYPE
6870 && vector_types_convertible_p (to, from, false))
6873 if (TREE_CODE (to) == INTEGER_TYPE
6874 && TYPE_PRECISION (to) == TYPE_PRECISION (from))
6877 if (TREE_CODE (to) == FUNCTION_TYPE)
6880 if (TREE_CODE (to) != POINTER_TYPE)
6882 (TYPE_MAIN_VARIANT (to), TYPE_MAIN_VARIANT (from),
6883 COMPARE_BASE | COMPARE_DERIVED);
6887 /* Return true if TO and FROM (both of which are POINTER_TYPEs or
6888 pointer-to-member types) are the same, ignoring cv-qualification at
6892 comp_ptr_ttypes_const (tree to, tree from)
6894 for (; ; to = TREE_TYPE (to), from = TREE_TYPE (from))
6896 if (TREE_CODE (to) != TREE_CODE (from))
6899 if (TREE_CODE (from) == OFFSET_TYPE
6900 && same_type_p (TYPE_OFFSET_BASETYPE (from),
6901 TYPE_OFFSET_BASETYPE (to)))
6904 if (TREE_CODE (to) != POINTER_TYPE)
6905 return same_type_ignoring_top_level_qualifiers_p (to, from);
6909 /* Returns the type qualifiers for this type, including the qualifiers on the
6910 elements for an array type. */
6913 cp_type_quals (tree type)
6915 type = strip_array_types (type);
6916 if (type == error_mark_node)
6917 return TYPE_UNQUALIFIED;
6918 return TYPE_QUALS (type);
6921 /* Returns nonzero if the TYPE is const from a C++ perspective: look inside
6925 cp_type_readonly (tree type)
6927 type = strip_array_types (type);
6928 return TYPE_READONLY (type);
6931 /* Returns nonzero if the TYPE contains a mutable member. */
6934 cp_has_mutable_p (tree type)
6936 type = strip_array_types (type);
6938 return CLASS_TYPE_P (type) && CLASSTYPE_HAS_MUTABLE (type);
6941 /* Apply the TYPE_QUALS to the new DECL. */
6943 cp_apply_type_quals_to_decl (int type_quals, tree decl)
6945 tree type = TREE_TYPE (decl);
6947 if (type == error_mark_node)
6950 if (TREE_CODE (type) == FUNCTION_TYPE
6951 && type_quals != TYPE_UNQUALIFIED)
6953 /* This was an error in C++98 (cv-qualifiers cannot be added to
6954 a function type), but DR 295 makes the code well-formed by
6955 dropping the extra qualifiers. */
6958 tree bad_type = build_qualified_type (type, type_quals);
6959 pedwarn ("ignoring %qV qualifiers added to function type %qT",
6963 TREE_TYPE (decl) = TYPE_MAIN_VARIANT (type);
6967 /* Avoid setting TREE_READONLY incorrectly. */
6968 if (/* If the object has a constructor, the constructor may modify
6970 TYPE_NEEDS_CONSTRUCTING (type)
6971 /* If the type isn't complete, we don't know yet if it will need
6973 || !COMPLETE_TYPE_P (type)
6974 /* If the type has a mutable component, that component might be
6976 || TYPE_HAS_MUTABLE_P (type))
6977 type_quals &= ~TYPE_QUAL_CONST;
6979 c_apply_type_quals_to_decl (type_quals, decl);
6982 /* Subroutine of casts_away_constness. Make T1 and T2 point at
6983 exemplar types such that casting T1 to T2 is casting away constness
6984 if and only if there is no implicit conversion from T1 to T2. */
6987 casts_away_constness_r (tree *t1, tree *t2)
6992 /* [expr.const.cast]
6994 For multi-level pointer to members and multi-level mixed pointers
6995 and pointers to members (conv.qual), the "member" aspect of a
6996 pointer to member level is ignored when determining if a const
6997 cv-qualifier has been cast away. */
6998 /* [expr.const.cast]
7000 For two pointer types:
7002 X1 is T1cv1,1 * ... cv1,N * where T1 is not a pointer type
7003 X2 is T2cv2,1 * ... cv2,M * where T2 is not a pointer type
7006 casting from X1 to X2 casts away constness if, for a non-pointer
7007 type T there does not exist an implicit conversion (clause
7010 Tcv1,(N-K+1) * cv1,(N-K+2) * ... cv1,N *
7014 Tcv2,(M-K+1) * cv2,(M-K+2) * ... cv2,M *. */
7015 if ((!TYPE_PTR_P (*t1) && !TYPE_PTRMEM_P (*t1))
7016 || (!TYPE_PTR_P (*t2) && !TYPE_PTRMEM_P (*t2)))
7018 *t1 = cp_build_qualified_type (void_type_node,
7019 cp_type_quals (*t1));
7020 *t2 = cp_build_qualified_type (void_type_node,
7021 cp_type_quals (*t2));
7025 quals1 = cp_type_quals (*t1);
7026 quals2 = cp_type_quals (*t2);
7028 if (TYPE_PTRMEM_P (*t1))
7029 *t1 = TYPE_PTRMEM_POINTED_TO_TYPE (*t1);
7031 *t1 = TREE_TYPE (*t1);
7032 if (TYPE_PTRMEM_P (*t2))
7033 *t2 = TYPE_PTRMEM_POINTED_TO_TYPE (*t2);
7035 *t2 = TREE_TYPE (*t2);
7037 casts_away_constness_r (t1, t2);
7038 *t1 = build_pointer_type (*t1);
7039 *t2 = build_pointer_type (*t2);
7040 *t1 = cp_build_qualified_type (*t1, quals1);
7041 *t2 = cp_build_qualified_type (*t2, quals2);
7044 /* Returns nonzero if casting from TYPE1 to TYPE2 casts away
7048 casts_away_constness (tree t1, tree t2)
7050 if (TREE_CODE (t2) == REFERENCE_TYPE)
7052 /* [expr.const.cast]
7054 Casting from an lvalue of type T1 to an lvalue of type T2
7055 using a reference cast casts away constness if a cast from an
7056 rvalue of type "pointer to T1" to the type "pointer to T2"
7057 casts away constness. */
7058 t1 = (TREE_CODE (t1) == REFERENCE_TYPE ? TREE_TYPE (t1) : t1);
7059 return casts_away_constness (build_pointer_type (t1),
7060 build_pointer_type (TREE_TYPE (t2)));
7063 if (TYPE_PTRMEM_P (t1) && TYPE_PTRMEM_P (t2))
7064 /* [expr.const.cast]
7066 Casting from an rvalue of type "pointer to data member of X
7067 of type T1" to the type "pointer to data member of Y of type
7068 T2" casts away constness if a cast from an rvalue of type
7069 "pointer to T1" to the type "pointer to T2" casts away
7071 return casts_away_constness
7072 (build_pointer_type (TYPE_PTRMEM_POINTED_TO_TYPE (t1)),
7073 build_pointer_type (TYPE_PTRMEM_POINTED_TO_TYPE (t2)));
7075 /* Casting away constness is only something that makes sense for
7076 pointer or reference types. */
7077 if (TREE_CODE (t1) != POINTER_TYPE
7078 || TREE_CODE (t2) != POINTER_TYPE)
7081 /* Top-level qualifiers don't matter. */
7082 t1 = TYPE_MAIN_VARIANT (t1);
7083 t2 = TYPE_MAIN_VARIANT (t2);
7084 casts_away_constness_r (&t1, &t2);
7085 if (!can_convert (t2, t1))
7091 /* If T is a REFERENCE_TYPE return the type to which T refers.
7092 Otherwise, return T itself. */
7095 non_reference (tree t)
7097 if (TREE_CODE (t) == REFERENCE_TYPE)
7103 /* Return nonzero if REF is an lvalue valid for this language;
7104 otherwise, print an error message and return zero. USE says
7105 how the lvalue is being used and so selects the error message. */
7108 lvalue_or_else (tree ref, enum lvalue_use use)
7110 int win = lvalue_p (ref);