1 /* Build expressions with type checking for C++ compiler.
2 Copyright (C) 1987, 1988, 1989, 1992, 1993, 1994, 1995, 1996, 1997, 1998,
3 1999, 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007
4 Free Software Foundation, Inc.
5 Hacked by Michael Tiemann (tiemann@cygnus.com)
7 This file is part of GCC.
9 GCC is free software; you can redistribute it and/or modify
10 it under the terms of the GNU General Public License as published by
11 the Free Software Foundation; either version 2, or (at your option)
14 GCC is distributed in the hope that it will be useful,
15 but WITHOUT ANY WARRANTY; without even the implied warranty of
16 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
17 GNU General Public License for more details.
19 You should have received a copy of the GNU General Public License
20 along with GCC; see the file COPYING. If not, write to
21 the Free Software Foundation, 51 Franklin Street, Fifth Floor,
22 Boston, MA 02110-1301, USA. */
25 /* This file is part of the C++ front end.
26 It contains routines to build C++ expressions given their operands,
27 including computing the types of the result, C and C++ specific error
28 checks, and some optimization. */
32 #include "coretypes.h"
42 #include "diagnostic.h"
49 static tree pfn_from_ptrmemfunc (tree);
50 static tree convert_for_assignment (tree, tree, const char *, tree, int);
51 static tree cp_pointer_int_sum (enum tree_code, tree, tree);
52 static tree rationalize_conditional_expr (enum tree_code, tree);
53 static int comp_ptr_ttypes_real (tree, tree, int);
54 static bool comp_except_types (tree, tree, bool);
55 static bool comp_array_types (tree, tree, bool);
56 static tree pointer_diff (tree, tree, tree);
57 static tree get_delta_difference (tree, tree, bool, bool);
58 static void casts_away_constness_r (tree *, tree *);
59 static bool casts_away_constness (tree, tree);
60 static void maybe_warn_about_returning_address_of_local (tree);
61 static tree lookup_destructor (tree, tree, tree);
62 static int convert_arguments (int, tree *, tree, tree, tree, int);
64 /* Do `exp = require_complete_type (exp);' to make sure exp
65 does not have an incomplete type. (That includes void types.)
66 Returns the error_mark_node if the VALUE does not have
67 complete type when this function returns. */
70 require_complete_type (tree value)
74 if (processing_template_decl || value == error_mark_node)
77 if (TREE_CODE (value) == OVERLOAD)
78 type = unknown_type_node;
80 type = TREE_TYPE (value);
82 if (type == error_mark_node)
83 return error_mark_node;
85 /* First, detect a valid value with a complete type. */
86 if (COMPLETE_TYPE_P (type))
89 if (complete_type_or_else (type, value))
92 return error_mark_node;
95 /* Try to complete TYPE, if it is incomplete. For example, if TYPE is
96 a template instantiation, do the instantiation. Returns TYPE,
97 whether or not it could be completed, unless something goes
98 horribly wrong, in which case the error_mark_node is returned. */
101 complete_type (tree type)
103 if (type == NULL_TREE)
104 /* Rather than crash, we return something sure to cause an error
106 return error_mark_node;
108 if (type == error_mark_node || COMPLETE_TYPE_P (type))
110 else if (TREE_CODE (type) == ARRAY_TYPE && TYPE_DOMAIN (type))
112 tree t = complete_type (TREE_TYPE (type));
113 unsigned int needs_constructing, has_nontrivial_dtor;
114 if (COMPLETE_TYPE_P (t) && !dependent_type_p (type))
117 = TYPE_NEEDS_CONSTRUCTING (TYPE_MAIN_VARIANT (t));
119 = TYPE_HAS_NONTRIVIAL_DESTRUCTOR (TYPE_MAIN_VARIANT (t));
120 for (t = TYPE_MAIN_VARIANT (type); t; t = TYPE_NEXT_VARIANT (t))
122 TYPE_NEEDS_CONSTRUCTING (t) = needs_constructing;
123 TYPE_HAS_NONTRIVIAL_DESTRUCTOR (t) = has_nontrivial_dtor;
126 else if (CLASS_TYPE_P (type) && CLASSTYPE_TEMPLATE_INSTANTIATION (type))
127 instantiate_class_template (TYPE_MAIN_VARIANT (type));
132 /* Like complete_type, but issue an error if the TYPE cannot be completed.
133 VALUE is used for informative diagnostics.
134 Returns NULL_TREE if the type cannot be made complete. */
137 complete_type_or_else (tree type, tree value)
139 type = complete_type (type);
140 if (type == error_mark_node)
141 /* We already issued an error. */
143 else if (!COMPLETE_TYPE_P (type))
145 cxx_incomplete_type_diagnostic (value, type, 0);
152 /* Return truthvalue of whether type of EXP is instantiated. */
155 type_unknown_p (tree exp)
157 return (TREE_CODE (exp) == TREE_LIST
158 || TREE_TYPE (exp) == unknown_type_node);
162 /* Return the common type of two parameter lists.
163 We assume that comptypes has already been done and returned 1;
164 if that isn't so, this may crash.
166 As an optimization, free the space we allocate if the parameter
167 lists are already common. */
170 commonparms (tree p1, tree p2)
172 tree oldargs = p1, newargs, n;
176 len = list_length (p1);
177 newargs = tree_last (p1);
179 if (newargs == void_list_node)
188 newargs = tree_cons (NULL_TREE, NULL_TREE, newargs);
193 p1 = TREE_CHAIN (p1), p2 = TREE_CHAIN (p2), n = TREE_CHAIN (n), i++)
195 if (TREE_PURPOSE (p1) && !TREE_PURPOSE (p2))
197 TREE_PURPOSE (n) = TREE_PURPOSE (p1);
200 else if (! TREE_PURPOSE (p1))
202 if (TREE_PURPOSE (p2))
204 TREE_PURPOSE (n) = TREE_PURPOSE (p2);
210 if (1 != simple_cst_equal (TREE_PURPOSE (p1), TREE_PURPOSE (p2)))
212 TREE_PURPOSE (n) = TREE_PURPOSE (p2);
214 if (TREE_VALUE (p1) != TREE_VALUE (p2))
217 TREE_VALUE (n) = merge_types (TREE_VALUE (p1), TREE_VALUE (p2));
220 TREE_VALUE (n) = TREE_VALUE (p1);
228 /* Given a type, perhaps copied for a typedef,
229 find the "original" version of it. */
231 original_type (tree t)
233 int quals = cp_type_quals (t);
234 while (t != error_mark_node
235 && TYPE_NAME (t) != NULL_TREE)
237 tree x = TYPE_NAME (t);
238 if (TREE_CODE (x) != TYPE_DECL)
240 x = DECL_ORIGINAL_TYPE (x);
245 return cp_build_qualified_type (t, quals);
248 /* T1 and T2 are arithmetic or enumeration types. Return the type
249 that will result from the "usual arithmetic conversions" on T1 and
250 T2 as described in [expr]. */
253 type_after_usual_arithmetic_conversions (tree t1, tree t2)
255 enum tree_code code1 = TREE_CODE (t1);
256 enum tree_code code2 = TREE_CODE (t2);
259 /* FIXME: Attributes. */
260 gcc_assert (ARITHMETIC_TYPE_P (t1)
261 || TREE_CODE (t1) == COMPLEX_TYPE
262 || TREE_CODE (t1) == VECTOR_TYPE
263 || TREE_CODE (t1) == ENUMERAL_TYPE);
264 gcc_assert (ARITHMETIC_TYPE_P (t2)
265 || TREE_CODE (t2) == COMPLEX_TYPE
266 || TREE_CODE (t2) == VECTOR_TYPE
267 || TREE_CODE (t2) == ENUMERAL_TYPE);
269 /* In what follows, we slightly generalize the rules given in [expr] so
270 as to deal with `long long' and `complex'. First, merge the
272 attributes = (*targetm.merge_type_attributes) (t1, t2);
274 /* If one type is complex, form the common type of the non-complex
275 components, then make that complex. Use T1 or T2 if it is the
277 if (code1 == COMPLEX_TYPE || code2 == COMPLEX_TYPE)
279 tree subtype1 = code1 == COMPLEX_TYPE ? TREE_TYPE (t1) : t1;
280 tree subtype2 = code2 == COMPLEX_TYPE ? TREE_TYPE (t2) : t2;
282 = type_after_usual_arithmetic_conversions (subtype1, subtype2);
284 if (code1 == COMPLEX_TYPE && TREE_TYPE (t1) == subtype)
285 return build_type_attribute_variant (t1, attributes);
286 else if (code2 == COMPLEX_TYPE && TREE_TYPE (t2) == subtype)
287 return build_type_attribute_variant (t2, attributes);
289 return build_type_attribute_variant (build_complex_type (subtype),
293 if (code1 == VECTOR_TYPE)
295 /* When we get here we should have two vectors of the same size.
296 Just prefer the unsigned one if present. */
297 if (TYPE_UNSIGNED (t1))
298 return build_type_attribute_variant (t1, attributes);
300 return build_type_attribute_variant (t2, attributes);
303 /* If only one is real, use it as the result. */
304 if (code1 == REAL_TYPE && code2 != REAL_TYPE)
305 return build_type_attribute_variant (t1, attributes);
306 if (code2 == REAL_TYPE && code1 != REAL_TYPE)
307 return build_type_attribute_variant (t2, attributes);
309 /* Perform the integral promotions. */
310 if (code1 != REAL_TYPE)
312 t1 = type_promotes_to (t1);
313 t2 = type_promotes_to (t2);
316 /* Both real or both integers; use the one with greater precision. */
317 if (TYPE_PRECISION (t1) > TYPE_PRECISION (t2))
318 return build_type_attribute_variant (t1, attributes);
319 else if (TYPE_PRECISION (t2) > TYPE_PRECISION (t1))
320 return build_type_attribute_variant (t2, attributes);
322 /* The types are the same; no need to do anything fancy. */
323 if (TYPE_MAIN_VARIANT (t1) == TYPE_MAIN_VARIANT (t2))
324 return build_type_attribute_variant (t1, attributes);
326 if (code1 != REAL_TYPE)
328 /* If one is unsigned long long, then convert the other to unsigned
330 if (same_type_p (TYPE_MAIN_VARIANT (t1), long_long_unsigned_type_node)
331 || same_type_p (TYPE_MAIN_VARIANT (t2), long_long_unsigned_type_node))
332 return build_type_attribute_variant (long_long_unsigned_type_node,
334 /* If one is a long long, and the other is an unsigned long, and
335 long long can represent all the values of an unsigned long, then
336 convert to a long long. Otherwise, convert to an unsigned long
337 long. Otherwise, if either operand is long long, convert the
340 Since we're here, we know the TYPE_PRECISION is the same;
341 therefore converting to long long cannot represent all the values
342 of an unsigned long, so we choose unsigned long long in that
344 if (same_type_p (TYPE_MAIN_VARIANT (t1), long_long_integer_type_node)
345 || same_type_p (TYPE_MAIN_VARIANT (t2), long_long_integer_type_node))
347 tree t = ((TYPE_UNSIGNED (t1) || TYPE_UNSIGNED (t2))
348 ? long_long_unsigned_type_node
349 : long_long_integer_type_node);
350 return build_type_attribute_variant (t, attributes);
353 /* Go through the same procedure, but for longs. */
354 if (same_type_p (TYPE_MAIN_VARIANT (t1), long_unsigned_type_node)
355 || same_type_p (TYPE_MAIN_VARIANT (t2), long_unsigned_type_node))
356 return build_type_attribute_variant (long_unsigned_type_node,
358 if (same_type_p (TYPE_MAIN_VARIANT (t1), long_integer_type_node)
359 || same_type_p (TYPE_MAIN_VARIANT (t2), long_integer_type_node))
361 tree t = ((TYPE_UNSIGNED (t1) || TYPE_UNSIGNED (t2))
362 ? long_unsigned_type_node : long_integer_type_node);
363 return build_type_attribute_variant (t, attributes);
365 /* Otherwise prefer the unsigned one. */
366 if (TYPE_UNSIGNED (t1))
367 return build_type_attribute_variant (t1, attributes);
369 return build_type_attribute_variant (t2, attributes);
373 if (same_type_p (TYPE_MAIN_VARIANT (t1), long_double_type_node)
374 || same_type_p (TYPE_MAIN_VARIANT (t2), long_double_type_node))
375 return build_type_attribute_variant (long_double_type_node,
377 if (same_type_p (TYPE_MAIN_VARIANT (t1), double_type_node)
378 || same_type_p (TYPE_MAIN_VARIANT (t2), double_type_node))
379 return build_type_attribute_variant (double_type_node,
381 if (same_type_p (TYPE_MAIN_VARIANT (t1), float_type_node)
382 || same_type_p (TYPE_MAIN_VARIANT (t2), float_type_node))
383 return build_type_attribute_variant (float_type_node,
386 /* Two floating-point types whose TYPE_MAIN_VARIANTs are none of
387 the standard C++ floating-point types. Logic earlier in this
388 function has already eliminated the possibility that
389 TYPE_PRECISION (t2) != TYPE_PRECISION (t1), so there's no
390 compelling reason to choose one or the other. */
391 return build_type_attribute_variant (t1, attributes);
395 /* Subroutine of composite_pointer_type to implement the recursive
396 case. See that function for documentation fo the parameters. */
399 composite_pointer_type_r (tree t1, tree t2, const char* location)
406 /* Determine the types pointed to by T1 and T2. */
407 if (TREE_CODE (t1) == POINTER_TYPE)
409 pointee1 = TREE_TYPE (t1);
410 pointee2 = TREE_TYPE (t2);
414 pointee1 = TYPE_PTRMEM_POINTED_TO_TYPE (t1);
415 pointee2 = TYPE_PTRMEM_POINTED_TO_TYPE (t2);
420 Otherwise, the composite pointer type is a pointer type
421 similar (_conv.qual_) to the type of one of the operands,
422 with a cv-qualification signature (_conv.qual_) that is the
423 union of the cv-qualification signatures of the operand
425 if (same_type_ignoring_top_level_qualifiers_p (pointee1, pointee2))
426 result_type = pointee1;
427 else if ((TREE_CODE (pointee1) == POINTER_TYPE
428 && TREE_CODE (pointee2) == POINTER_TYPE)
429 || (TYPE_PTR_TO_MEMBER_P (pointee1)
430 && TYPE_PTR_TO_MEMBER_P (pointee2)))
431 result_type = composite_pointer_type_r (pointee1, pointee2, location);
434 pedwarn ("%s between distinct pointer types %qT and %qT "
437 result_type = void_type_node;
439 result_type = cp_build_qualified_type (result_type,
440 (cp_type_quals (pointee1)
441 | cp_type_quals (pointee2)));
442 /* If the original types were pointers to members, so is the
444 if (TYPE_PTR_TO_MEMBER_P (t1))
446 if (!same_type_p (TYPE_PTRMEM_CLASS_TYPE (t1),
447 TYPE_PTRMEM_CLASS_TYPE (t2)))
448 pedwarn ("%s between distinct pointer types %qT and %qT "
451 result_type = build_ptrmem_type (TYPE_PTRMEM_CLASS_TYPE (t1),
455 result_type = build_pointer_type (result_type);
457 /* Merge the attributes. */
458 attributes = (*targetm.merge_type_attributes) (t1, t2);
459 return build_type_attribute_variant (result_type, attributes);
462 /* Return the composite pointer type (see [expr.rel]) for T1 and T2.
463 ARG1 and ARG2 are the values with those types. The LOCATION is a
464 string describing the current location, in case an error occurs.
466 This routine also implements the computation of a common type for
467 pointers-to-members as per [expr.eq]. */
470 composite_pointer_type (tree t1, tree t2, tree arg1, tree arg2,
471 const char* location)
478 If one operand is a null pointer constant, the composite pointer
479 type is the type of the other operand. */
480 if (null_ptr_cst_p (arg1))
482 if (null_ptr_cst_p (arg2))
489 If one of the operands has type "pointer to cv1 void*", then
490 the other has type "pointer to cv2T", and the composite pointer
491 type is "pointer to cv12 void", where cv12 is the union of cv1
494 If either type is a pointer to void, make sure it is T1. */
495 if (TREE_CODE (t2) == POINTER_TYPE && VOID_TYPE_P (TREE_TYPE (t2)))
503 /* Now, if T1 is a pointer to void, merge the qualifiers. */
504 if (TREE_CODE (t1) == POINTER_TYPE && VOID_TYPE_P (TREE_TYPE (t1)))
509 if (pedantic && TYPE_PTRFN_P (t2))
510 pedwarn ("ISO C++ forbids %s between pointer of type %<void *%> "
511 "and pointer-to-function", location);
513 = cp_build_qualified_type (void_type_node,
514 (cp_type_quals (TREE_TYPE (t1))
515 | cp_type_quals (TREE_TYPE (t2))));
516 result_type = build_pointer_type (result_type);
517 /* Merge the attributes. */
518 attributes = (*targetm.merge_type_attributes) (t1, t2);
519 return build_type_attribute_variant (result_type, attributes);
522 if (c_dialect_objc () && TREE_CODE (t1) == POINTER_TYPE
523 && TREE_CODE (t2) == POINTER_TYPE)
525 if (objc_compare_types (t1, t2, -3, NULL_TREE))
529 /* [expr.eq] permits the application of a pointer conversion to
530 bring the pointers to a common type. */
531 if (TREE_CODE (t1) == POINTER_TYPE && TREE_CODE (t2) == POINTER_TYPE
532 && CLASS_TYPE_P (TREE_TYPE (t1))
533 && CLASS_TYPE_P (TREE_TYPE (t2))
534 && !same_type_ignoring_top_level_qualifiers_p (TREE_TYPE (t1),
537 class1 = TREE_TYPE (t1);
538 class2 = TREE_TYPE (t2);
540 if (DERIVED_FROM_P (class1, class2))
541 t2 = (build_pointer_type
542 (cp_build_qualified_type (class1, TYPE_QUALS (class2))));
543 else if (DERIVED_FROM_P (class2, class1))
544 t1 = (build_pointer_type
545 (cp_build_qualified_type (class2, TYPE_QUALS (class1))));
548 error ("%s between distinct pointer types %qT and %qT "
549 "lacks a cast", location, t1, t2);
550 return error_mark_node;
553 /* [expr.eq] permits the application of a pointer-to-member
554 conversion to change the class type of one of the types. */
555 else if (TYPE_PTR_TO_MEMBER_P (t1)
556 && !same_type_p (TYPE_PTRMEM_CLASS_TYPE (t1),
557 TYPE_PTRMEM_CLASS_TYPE (t2)))
559 class1 = TYPE_PTRMEM_CLASS_TYPE (t1);
560 class2 = TYPE_PTRMEM_CLASS_TYPE (t2);
562 if (DERIVED_FROM_P (class1, class2))
563 t1 = build_ptrmem_type (class2, TYPE_PTRMEM_POINTED_TO_TYPE (t1));
564 else if (DERIVED_FROM_P (class2, class1))
565 t2 = build_ptrmem_type (class1, TYPE_PTRMEM_POINTED_TO_TYPE (t2));
568 error ("%s between distinct pointer-to-member types %qT and %qT "
569 "lacks a cast", location, t1, t2);
570 return error_mark_node;
574 return composite_pointer_type_r (t1, t2, location);
577 /* Return the merged type of two types.
578 We assume that comptypes has already been done and returned 1;
579 if that isn't so, this may crash.
581 This just combines attributes and default arguments; any other
582 differences would cause the two types to compare unalike. */
585 merge_types (tree t1, tree t2)
587 enum tree_code code1;
588 enum tree_code code2;
591 /* Save time if the two types are the same. */
594 if (original_type (t1) == original_type (t2))
597 /* If one type is nonsense, use the other. */
598 if (t1 == error_mark_node)
600 if (t2 == error_mark_node)
603 /* Merge the attributes. */
604 attributes = (*targetm.merge_type_attributes) (t1, t2);
606 if (TYPE_PTRMEMFUNC_P (t1))
607 t1 = TYPE_PTRMEMFUNC_FN_TYPE (t1);
608 if (TYPE_PTRMEMFUNC_P (t2))
609 t2 = TYPE_PTRMEMFUNC_FN_TYPE (t2);
611 code1 = TREE_CODE (t1);
612 code2 = TREE_CODE (t2);
618 /* For two pointers, do this recursively on the target type. */
620 tree target = merge_types (TREE_TYPE (t1), TREE_TYPE (t2));
621 int quals = cp_type_quals (t1);
623 if (code1 == POINTER_TYPE)
624 t1 = build_pointer_type (target);
626 t1 = build_reference_type (target);
627 t1 = build_type_attribute_variant (t1, attributes);
628 t1 = cp_build_qualified_type (t1, quals);
630 if (TREE_CODE (target) == METHOD_TYPE)
631 t1 = build_ptrmemfunc_type (t1);
640 quals = cp_type_quals (t1);
641 pointee = merge_types (TYPE_PTRMEM_POINTED_TO_TYPE (t1),
642 TYPE_PTRMEM_POINTED_TO_TYPE (t2));
643 t1 = build_ptrmem_type (TYPE_PTRMEM_CLASS_TYPE (t1),
645 t1 = cp_build_qualified_type (t1, quals);
651 tree elt = merge_types (TREE_TYPE (t1), TREE_TYPE (t2));
652 /* Save space: see if the result is identical to one of the args. */
653 if (elt == TREE_TYPE (t1) && TYPE_DOMAIN (t1))
654 return build_type_attribute_variant (t1, attributes);
655 if (elt == TREE_TYPE (t2) && TYPE_DOMAIN (t2))
656 return build_type_attribute_variant (t2, attributes);
657 /* Merge the element types, and have a size if either arg has one. */
658 t1 = build_cplus_array_type
659 (elt, TYPE_DOMAIN (TYPE_DOMAIN (t1) ? t1 : t2));
664 /* Function types: prefer the one that specified arg types.
665 If both do, merge the arg types. Also merge the return types. */
667 tree valtype = merge_types (TREE_TYPE (t1), TREE_TYPE (t2));
668 tree p1 = TYPE_ARG_TYPES (t1);
669 tree p2 = TYPE_ARG_TYPES (t2);
672 /* Save space: see if the result is identical to one of the args. */
673 if (valtype == TREE_TYPE (t1) && ! p2)
674 return cp_build_type_attribute_variant (t1, attributes);
675 if (valtype == TREE_TYPE (t2) && ! p1)
676 return cp_build_type_attribute_variant (t2, attributes);
678 /* Simple way if one arg fails to specify argument types. */
679 if (p1 == NULL_TREE || TREE_VALUE (p1) == void_type_node)
681 rval = build_function_type (valtype, p2);
682 if ((raises = TYPE_RAISES_EXCEPTIONS (t2)))
683 rval = build_exception_variant (rval, raises);
684 return cp_build_type_attribute_variant (rval, attributes);
686 raises = TYPE_RAISES_EXCEPTIONS (t1);
687 if (p2 == NULL_TREE || TREE_VALUE (p2) == void_type_node)
689 rval = build_function_type (valtype, p1);
691 rval = build_exception_variant (rval, raises);
692 return cp_build_type_attribute_variant (rval, attributes);
695 rval = build_function_type (valtype, commonparms (p1, p2));
696 t1 = build_exception_variant (rval, raises);
702 /* Get this value the long way, since TYPE_METHOD_BASETYPE
703 is just the main variant of this. */
704 tree basetype = TREE_TYPE (TREE_VALUE (TYPE_ARG_TYPES (t2)));
705 tree raises = TYPE_RAISES_EXCEPTIONS (t1);
708 /* If this was a member function type, get back to the
709 original type of type member function (i.e., without
710 the class instance variable up front. */
711 t1 = build_function_type (TREE_TYPE (t1),
712 TREE_CHAIN (TYPE_ARG_TYPES (t1)));
713 t2 = build_function_type (TREE_TYPE (t2),
714 TREE_CHAIN (TYPE_ARG_TYPES (t2)));
715 t3 = merge_types (t1, t2);
716 t3 = build_method_type_directly (basetype, TREE_TYPE (t3),
717 TYPE_ARG_TYPES (t3));
718 t1 = build_exception_variant (t3, raises);
723 /* There is no need to merge attributes into a TYPENAME_TYPE.
724 When the type is instantiated it will have whatever
725 attributes result from the instantiation. */
731 if (attribute_list_equal (TYPE_ATTRIBUTES (t1), attributes))
733 else if (attribute_list_equal (TYPE_ATTRIBUTES (t2), attributes))
736 return cp_build_type_attribute_variant (t1, attributes);
739 /* Return the common type of two types.
740 We assume that comptypes has already been done and returned 1;
741 if that isn't so, this may crash.
743 This is the type for the result of most arithmetic operations
744 if the operands have the given two types. */
747 common_type (tree t1, tree t2)
749 enum tree_code code1;
750 enum tree_code code2;
752 /* If one type is nonsense, bail. */
753 if (t1 == error_mark_node || t2 == error_mark_node)
754 return error_mark_node;
756 code1 = TREE_CODE (t1);
757 code2 = TREE_CODE (t2);
759 if ((ARITHMETIC_TYPE_P (t1) || code1 == ENUMERAL_TYPE
760 || code1 == COMPLEX_TYPE || code1 == VECTOR_TYPE)
761 && (ARITHMETIC_TYPE_P (t2) || code2 == ENUMERAL_TYPE
762 || code2 == COMPLEX_TYPE || code2 == VECTOR_TYPE))
763 return type_after_usual_arithmetic_conversions (t1, t2);
765 else if ((TYPE_PTR_P (t1) && TYPE_PTR_P (t2))
766 || (TYPE_PTRMEM_P (t1) && TYPE_PTRMEM_P (t2))
767 || (TYPE_PTRMEMFUNC_P (t1) && TYPE_PTRMEMFUNC_P (t2)))
768 return composite_pointer_type (t1, t2, error_mark_node, error_mark_node,
774 /* Compare two exception specifier types for exactness or subsetness, if
775 allowed. Returns false for mismatch, true for match (same, or
778 [except.spec] "If a class X ... objects of class X or any class publicly
779 and unambiguously derived from X. Similarly, if a pointer type Y * ...
780 exceptions of type Y * or that are pointers to any type publicly and
781 unambiguously derived from Y. Otherwise a function only allows exceptions
782 that have the same type ..."
783 This does not mention cv qualifiers and is different to what throw
784 [except.throw] and catch [except.catch] will do. They will ignore the
785 top level cv qualifiers, and allow qualifiers in the pointer to class
788 We implement the letter of the standard. */
791 comp_except_types (tree a, tree b, bool exact)
793 if (same_type_p (a, b))
797 if (cp_type_quals (a) || cp_type_quals (b))
800 if (TREE_CODE (a) == POINTER_TYPE
801 && TREE_CODE (b) == POINTER_TYPE)
805 if (cp_type_quals (a) || cp_type_quals (b))
809 if (TREE_CODE (a) != RECORD_TYPE
810 || TREE_CODE (b) != RECORD_TYPE)
813 if (PUBLICLY_UNIQUELY_DERIVED_P (a, b))
819 /* Return true if TYPE1 and TYPE2 are equivalent exception specifiers.
820 If EXACT is false, T2 can be stricter than T1 (according to 15.4/7),
821 otherwise it must be exact. Exception lists are unordered, but
822 we've already filtered out duplicates. Most lists will be in order,
823 we should try to make use of that. */
826 comp_except_specs (tree t1, tree t2, bool exact)
835 if (t1 == NULL_TREE) /* T1 is ... */
836 return t2 == NULL_TREE || !exact;
837 if (!TREE_VALUE (t1)) /* t1 is EMPTY */
838 return t2 != NULL_TREE && !TREE_VALUE (t2);
839 if (t2 == NULL_TREE) /* T2 is ... */
841 if (TREE_VALUE (t1) && !TREE_VALUE (t2)) /* T2 is EMPTY, T1 is not */
844 /* Neither set is ... or EMPTY, make sure each part of T2 is in T1.
845 Count how many we find, to determine exactness. For exact matching and
846 ordered T1, T2, this is an O(n) operation, otherwise its worst case is
848 for (base = t1; t2 != NULL_TREE; t2 = TREE_CHAIN (t2))
850 for (probe = base; probe != NULL_TREE; probe = TREE_CHAIN (probe))
852 tree a = TREE_VALUE (probe);
853 tree b = TREE_VALUE (t2);
855 if (comp_except_types (a, b, exact))
857 if (probe == base && exact)
858 base = TREE_CHAIN (probe);
863 if (probe == NULL_TREE)
866 return !exact || base == NULL_TREE || length == list_length (t1);
869 /* Compare the array types T1 and T2. ALLOW_REDECLARATION is true if
870 [] can match [size]. */
873 comp_array_types (tree t1, tree t2, bool allow_redeclaration)
882 /* The type of the array elements must be the same. */
883 if (!same_type_p (TREE_TYPE (t1), TREE_TYPE (t2)))
886 d1 = TYPE_DOMAIN (t1);
887 d2 = TYPE_DOMAIN (t2);
892 /* If one of the arrays is dimensionless, and the other has a
893 dimension, they are of different types. However, it is valid to
901 declarations for an array object can specify
902 array types that differ by the presence or absence of a major
903 array bound (_dcl.array_). */
905 return allow_redeclaration;
907 /* Check that the dimensions are the same. */
909 if (!cp_tree_equal (TYPE_MIN_VALUE (d1), TYPE_MIN_VALUE (d2)))
911 max1 = TYPE_MAX_VALUE (d1);
912 max2 = TYPE_MAX_VALUE (d2);
913 if (processing_template_decl && !abi_version_at_least (2)
914 && !value_dependent_expression_p (max1)
915 && !value_dependent_expression_p (max2))
917 /* With abi-1 we do not fold non-dependent array bounds, (and
918 consequently mangle them incorrectly). We must therefore
919 fold them here, to verify the domains have the same
925 if (!cp_tree_equal (max1, max2))
931 /* Subroutine in comptypes. */
934 structural_comptypes (tree t1, tree t2, int strict)
939 /* Suppress errors caused by previously reported errors. */
940 if (t1 == error_mark_node || t2 == error_mark_node)
943 gcc_assert (TYPE_P (t1) && TYPE_P (t2));
945 /* TYPENAME_TYPEs should be resolved if the qualifying scope is the
946 current instantiation. */
947 if (TREE_CODE (t1) == TYPENAME_TYPE)
949 tree resolved = resolve_typename_type (t1, /*only_current_p=*/true);
951 if (resolved != error_mark_node)
955 if (TREE_CODE (t2) == TYPENAME_TYPE)
957 tree resolved = resolve_typename_type (t2, /*only_current_p=*/true);
959 if (resolved != error_mark_node)
963 if (TYPE_PTRMEMFUNC_P (t1))
964 t1 = TYPE_PTRMEMFUNC_FN_TYPE (t1);
965 if (TYPE_PTRMEMFUNC_P (t2))
966 t2 = TYPE_PTRMEMFUNC_FN_TYPE (t2);
968 /* Different classes of types can't be compatible. */
969 if (TREE_CODE (t1) != TREE_CODE (t2))
972 /* Qualifiers must match. For array types, we will check when we
973 recur on the array element types. */
974 if (TREE_CODE (t1) != ARRAY_TYPE
975 && TYPE_QUALS (t1) != TYPE_QUALS (t2))
977 if (TYPE_FOR_JAVA (t1) != TYPE_FOR_JAVA (t2))
980 /* Allow for two different type nodes which have essentially the same
981 definition. Note that we already checked for equality of the type
982 qualifiers (just above). */
984 if (TREE_CODE (t1) != ARRAY_TYPE
985 && TYPE_MAIN_VARIANT (t1) == TYPE_MAIN_VARIANT (t2))
988 /* Compare the types. Break out if they could be the same. */
989 switch (TREE_CODE (t1))
991 case TEMPLATE_TEMPLATE_PARM:
992 case BOUND_TEMPLATE_TEMPLATE_PARM:
993 if (TEMPLATE_TYPE_IDX (t1) != TEMPLATE_TYPE_IDX (t2)
994 || TEMPLATE_TYPE_LEVEL (t1) != TEMPLATE_TYPE_LEVEL (t2)
995 || (TEMPLATE_TYPE_PARAMETER_PACK (t1)
996 != TEMPLATE_TYPE_PARAMETER_PACK (t2)))
998 if (!comp_template_parms
999 (DECL_TEMPLATE_PARMS (TEMPLATE_TEMPLATE_PARM_TEMPLATE_DECL (t1)),
1000 DECL_TEMPLATE_PARMS (TEMPLATE_TEMPLATE_PARM_TEMPLATE_DECL (t2))))
1002 if (TREE_CODE (t1) == TEMPLATE_TEMPLATE_PARM)
1004 /* Don't check inheritance. */
1005 strict = COMPARE_STRICT;
1010 if (TYPE_TEMPLATE_INFO (t1) && TYPE_TEMPLATE_INFO (t2)
1011 && (TYPE_TI_TEMPLATE (t1) == TYPE_TI_TEMPLATE (t2)
1012 || TREE_CODE (t1) == BOUND_TEMPLATE_TEMPLATE_PARM)
1013 && comp_template_args (TYPE_TI_ARGS (t1), TYPE_TI_ARGS (t2)))
1016 if ((strict & COMPARE_BASE) && DERIVED_FROM_P (t1, t2))
1018 else if ((strict & COMPARE_DERIVED) && DERIVED_FROM_P (t2, t1))
1024 if (!comptypes (TYPE_OFFSET_BASETYPE (t1), TYPE_OFFSET_BASETYPE (t2),
1025 strict & ~COMPARE_REDECLARATION))
1027 if (!same_type_p (TREE_TYPE (t1), TREE_TYPE (t2)))
1032 case REFERENCE_TYPE:
1033 if (TYPE_MODE (t1) != TYPE_MODE (t2)
1034 || TYPE_REF_CAN_ALIAS_ALL (t1) != TYPE_REF_CAN_ALIAS_ALL (t2)
1035 || !same_type_p (TREE_TYPE (t1), TREE_TYPE (t2)))
1041 if (!same_type_p (TREE_TYPE (t1), TREE_TYPE (t2)))
1043 if (!compparms (TYPE_ARG_TYPES (t1), TYPE_ARG_TYPES (t2)))
1048 /* Target types must match incl. qualifiers. */
1049 if (!comp_array_types (t1, t2, !!(strict & COMPARE_REDECLARATION)))
1053 case TEMPLATE_TYPE_PARM:
1054 if (TEMPLATE_TYPE_IDX (t1) != TEMPLATE_TYPE_IDX (t2)
1055 || TEMPLATE_TYPE_LEVEL (t1) != TEMPLATE_TYPE_LEVEL (t2)
1056 || (TEMPLATE_TYPE_PARAMETER_PACK (t1)
1057 != TEMPLATE_TYPE_PARAMETER_PACK (t2)))
1062 if (!cp_tree_equal (TYPENAME_TYPE_FULLNAME (t1),
1063 TYPENAME_TYPE_FULLNAME (t2)))
1065 if (!same_type_p (TYPE_CONTEXT (t1), TYPE_CONTEXT (t2)))
1069 case UNBOUND_CLASS_TEMPLATE:
1070 if (!cp_tree_equal (TYPE_IDENTIFIER (t1), TYPE_IDENTIFIER (t2)))
1072 if (!same_type_p (TYPE_CONTEXT (t1), TYPE_CONTEXT (t2)))
1077 if (!same_type_p (TREE_TYPE (t1), TREE_TYPE (t2)))
1082 if (TYPE_VECTOR_SUBPARTS (t1) != TYPE_VECTOR_SUBPARTS (t2)
1083 || !same_type_p (TREE_TYPE (t1), TREE_TYPE (t2)))
1087 case TYPE_PACK_EXPANSION:
1088 return same_type_p (PACK_EXPANSION_PATTERN (t1),
1089 PACK_EXPANSION_PATTERN (t2));
1095 /* If we get here, we know that from a target independent POV the
1096 types are the same. Make sure the target attributes are also
1098 return targetm.comp_type_attributes (t1, t2);
1101 /* Return true if T1 and T2 are related as allowed by STRICT. STRICT
1102 is a bitwise-or of the COMPARE_* flags. */
1105 comptypes (tree t1, tree t2, int strict)
1107 if (strict == COMPARE_STRICT)
1114 if (t1 == error_mark_node || t2 == error_mark_node)
1117 if (TYPE_STRUCTURAL_EQUALITY_P (t1) || TYPE_STRUCTURAL_EQUALITY_P (t2))
1118 /* At least one of the types requires structural equality, so
1119 perform a deep check. */
1120 return structural_comptypes (t1, t2, strict);
1122 if (VERIFY_CANONICAL_TYPES)
1124 result = structural_comptypes (t1, t2, strict);
1126 if (result && TYPE_CANONICAL (t1) != TYPE_CANONICAL (t2))
1128 /* The two types are structurally equivalent, but their
1129 canonical types were different. This is a failure of the
1130 canonical type propagation code.*/
1132 "canonical types differ for identical types %T and %T",
1137 else if (!result && TYPE_CANONICAL (t1) == TYPE_CANONICAL (t2))
1139 /* Two types are structurally different, but the canonical
1140 types are the same. This means we were over-eager in
1141 assigning canonical types. */
1143 "same canonical type node for different types %T and %T",
1152 return TYPE_CANONICAL (t1) == TYPE_CANONICAL (t2);
1154 else if (strict == COMPARE_STRUCTURAL)
1155 return structural_comptypes (t1, t2, COMPARE_STRICT);
1157 return structural_comptypes (t1, t2, strict);
1160 /* Returns 1 if TYPE1 is at least as qualified as TYPE2. */
1163 at_least_as_qualified_p (tree type1, tree type2)
1165 int q1 = cp_type_quals (type1);
1166 int q2 = cp_type_quals (type2);
1168 /* All qualifiers for TYPE2 must also appear in TYPE1. */
1169 return (q1 & q2) == q2;
1172 /* Returns 1 if TYPE1 is more cv-qualified than TYPE2, -1 if TYPE2 is
1173 more cv-qualified that TYPE1, and 0 otherwise. */
1176 comp_cv_qualification (tree type1, tree type2)
1178 int q1 = cp_type_quals (type1);
1179 int q2 = cp_type_quals (type2);
1184 if ((q1 & q2) == q2)
1186 else if ((q1 & q2) == q1)
1192 /* Returns 1 if the cv-qualification signature of TYPE1 is a proper
1193 subset of the cv-qualification signature of TYPE2, and the types
1194 are similar. Returns -1 if the other way 'round, and 0 otherwise. */
1197 comp_cv_qual_signature (tree type1, tree type2)
1199 if (comp_ptr_ttypes_real (type2, type1, -1))
1201 else if (comp_ptr_ttypes_real (type1, type2, -1))
1207 /* Subroutines of `comptypes'. */
1209 /* Return true if two parameter type lists PARMS1 and PARMS2 are
1210 equivalent in the sense that functions with those parameter types
1211 can have equivalent types. The two lists must be equivalent,
1212 element by element. */
1215 compparms (tree parms1, tree parms2)
1219 /* An unspecified parmlist matches any specified parmlist
1220 whose argument types don't need default promotions. */
1222 for (t1 = parms1, t2 = parms2;
1224 t1 = TREE_CHAIN (t1), t2 = TREE_CHAIN (t2))
1226 /* If one parmlist is shorter than the other,
1227 they fail to match. */
1230 if (!same_type_p (TREE_VALUE (t1), TREE_VALUE (t2)))
1237 /* Process a sizeof or alignof expression where the operand is a
1241 cxx_sizeof_or_alignof_type (tree type, enum tree_code op, bool complain)
1246 gcc_assert (op == SIZEOF_EXPR || op == ALIGNOF_EXPR);
1247 if (type == error_mark_node)
1248 return error_mark_node;
1250 type = non_reference (type);
1251 if (TREE_CODE (type) == METHOD_TYPE)
1253 if (complain && (pedantic || warn_pointer_arith))
1254 pedwarn ("invalid application of %qs to a member function",
1255 operator_name_info[(int) op].name);
1256 value = size_one_node;
1259 dependent_p = dependent_type_p (type);
1261 complete_type (type);
1263 /* VLA types will have a non-constant size. In the body of an
1264 uninstantiated template, we don't need to try to compute the
1265 value, because the sizeof expression is not an integral
1266 constant expression in that case. And, if we do try to
1267 compute the value, we'll likely end up with SAVE_EXPRs, which
1268 the template substitution machinery does not expect to see. */
1269 || (processing_template_decl
1270 && COMPLETE_TYPE_P (type)
1271 && TREE_CODE (TYPE_SIZE (type)) != INTEGER_CST))
1273 value = build_min (op, size_type_node, type);
1274 TREE_READONLY (value) = 1;
1278 return c_sizeof_or_alignof_type (complete_type (type),
1283 /* Process a sizeof expression where the operand is an expression. */
1286 cxx_sizeof_expr (tree e)
1288 if (e == error_mark_node)
1289 return error_mark_node;
1291 if (processing_template_decl)
1293 e = build_min (SIZEOF_EXPR, size_type_node, e);
1294 TREE_SIDE_EFFECTS (e) = 0;
1295 TREE_READONLY (e) = 1;
1300 if (TREE_CODE (e) == COMPONENT_REF
1301 && TREE_CODE (TREE_OPERAND (e, 1)) == FIELD_DECL
1302 && DECL_C_BIT_FIELD (TREE_OPERAND (e, 1)))
1304 error ("invalid application of %<sizeof%> to a bit-field");
1307 else if (is_overloaded_fn (e))
1309 pedwarn ("ISO C++ forbids applying %<sizeof%> to an expression of "
1313 else if (type_unknown_p (e))
1315 cxx_incomplete_type_error (e, TREE_TYPE (e));
1321 return cxx_sizeof_or_alignof_type (e, SIZEOF_EXPR, true);
1324 /* Implement the __alignof keyword: Return the minimum required
1325 alignment of E, measured in bytes. For VAR_DECL's and
1326 FIELD_DECL's return DECL_ALIGN (which can be set from an
1327 "aligned" __attribute__ specification). */
1330 cxx_alignof_expr (tree e)
1334 if (e == error_mark_node)
1335 return error_mark_node;
1337 if (processing_template_decl)
1339 e = build_min (ALIGNOF_EXPR, size_type_node, e);
1340 TREE_SIDE_EFFECTS (e) = 0;
1341 TREE_READONLY (e) = 1;
1346 if (TREE_CODE (e) == VAR_DECL)
1347 t = size_int (DECL_ALIGN_UNIT (e));
1348 else if (TREE_CODE (e) == COMPONENT_REF
1349 && TREE_CODE (TREE_OPERAND (e, 1)) == FIELD_DECL
1350 && DECL_C_BIT_FIELD (TREE_OPERAND (e, 1)))
1352 error ("invalid application of %<__alignof%> to a bit-field");
1355 else if (TREE_CODE (e) == COMPONENT_REF
1356 && TREE_CODE (TREE_OPERAND (e, 1)) == FIELD_DECL)
1357 t = size_int (DECL_ALIGN_UNIT (TREE_OPERAND (e, 1)));
1358 else if (is_overloaded_fn (e))
1360 pedwarn ("ISO C++ forbids applying %<__alignof%> to an expression of "
1364 else if (type_unknown_p (e))
1366 cxx_incomplete_type_error (e, TREE_TYPE (e));
1370 return cxx_sizeof_or_alignof_type (TREE_TYPE (e), ALIGNOF_EXPR, true);
1372 return fold_convert (size_type_node, t);
1375 /* Process a sizeof or alignof expression E with code OP where the operand
1376 is an expression. */
1379 cxx_sizeof_or_alignof_expr (tree e, enum tree_code op)
1381 if (op == SIZEOF_EXPR)
1382 return cxx_sizeof_expr (e);
1384 return cxx_alignof_expr (e);
1387 /* EXPR is being used in a context that is not a function call.
1392 The expression can be used only as the left-hand operand of a
1393 member function call.
1395 [expr.mptr.operator]
1397 If the result of .* or ->* is a function, then that result can be
1398 used only as the operand for the function call operator ().
1400 by issuing an error message if appropriate. Returns true iff EXPR
1401 violates these rules. */
1404 invalid_nonstatic_memfn_p (tree expr)
1406 if (TREE_CODE (TREE_TYPE (expr)) == METHOD_TYPE)
1408 error ("invalid use of non-static member function");
1414 /* If EXP is a reference to a bitfield, and the type of EXP does not
1415 match the declared type of the bitfield, return the declared type
1416 of the bitfield. Otherwise, return NULL_TREE. */
1419 is_bitfield_expr_with_lowered_type (tree exp)
1421 switch (TREE_CODE (exp))
1424 if (!is_bitfield_expr_with_lowered_type (TREE_OPERAND (exp, 1)))
1426 return is_bitfield_expr_with_lowered_type (TREE_OPERAND (exp, 2));
1429 return is_bitfield_expr_with_lowered_type (TREE_OPERAND (exp, 1));
1433 return is_bitfield_expr_with_lowered_type (TREE_OPERAND (exp, 0));
1439 field = TREE_OPERAND (exp, 1);
1440 if (TREE_CODE (field) != FIELD_DECL || !DECL_C_BIT_FIELD (field))
1442 if (same_type_ignoring_top_level_qualifiers_p
1443 (TREE_TYPE (exp), DECL_BIT_FIELD_TYPE (field)))
1445 return DECL_BIT_FIELD_TYPE (field);
1453 /* Like is_bitfield_with_lowered_type, except that if EXP is not a
1454 bitfield with a lowered type, the type of EXP is returned, rather
1458 unlowered_expr_type (tree exp)
1462 type = is_bitfield_expr_with_lowered_type (exp);
1464 type = TREE_TYPE (exp);
1469 /* Perform the conversions in [expr] that apply when an lvalue appears
1470 in an rvalue context: the lvalue-to-rvalue, array-to-pointer, and
1471 function-to-pointer conversions. In addition, manifest constants
1472 are replaced by their values, and bitfield references are converted
1473 to their declared types.
1475 Although the returned value is being used as an rvalue, this
1476 function does not wrap the returned expression in a
1477 NON_LVALUE_EXPR; the caller is expected to be mindful of the fact
1478 that the return value is no longer an lvalue. */
1481 decay_conversion (tree exp)
1484 enum tree_code code;
1486 type = TREE_TYPE (exp);
1487 if (type == error_mark_node)
1488 return error_mark_node;
1490 if (type_unknown_p (exp))
1492 cxx_incomplete_type_error (exp, TREE_TYPE (exp));
1493 return error_mark_node;
1496 exp = decl_constant_value (exp);
1497 if (error_operand_p (exp))
1498 return error_mark_node;
1500 /* build_c_cast puts on a NOP_EXPR to make the result not an lvalue.
1501 Leave such NOP_EXPRs, since RHS is being used in non-lvalue context. */
1502 code = TREE_CODE (type);
1503 if (code == VOID_TYPE)
1505 error ("void value not ignored as it ought to be");
1506 return error_mark_node;
1508 if (invalid_nonstatic_memfn_p (exp))
1509 return error_mark_node;
1510 if (code == FUNCTION_TYPE || is_overloaded_fn (exp))
1511 return build_unary_op (ADDR_EXPR, exp, 0);
1512 if (code == ARRAY_TYPE)
1517 if (TREE_CODE (exp) == INDIRECT_REF)
1518 return build_nop (build_pointer_type (TREE_TYPE (type)),
1519 TREE_OPERAND (exp, 0));
1521 if (TREE_CODE (exp) == COMPOUND_EXPR)
1523 tree op1 = decay_conversion (TREE_OPERAND (exp, 1));
1524 return build2 (COMPOUND_EXPR, TREE_TYPE (op1),
1525 TREE_OPERAND (exp, 0), op1);
1529 && ! (TREE_CODE (exp) == CONSTRUCTOR && TREE_STATIC (exp)))
1531 error ("invalid use of non-lvalue array");
1532 return error_mark_node;
1535 ptrtype = build_pointer_type (TREE_TYPE (type));
1537 if (TREE_CODE (exp) == VAR_DECL)
1539 if (!cxx_mark_addressable (exp))
1540 return error_mark_node;
1541 adr = build_nop (ptrtype, build_address (exp));
1544 /* This way is better for a COMPONENT_REF since it can
1545 simplify the offset for a component. */
1546 adr = build_unary_op (ADDR_EXPR, exp, 1);
1547 return cp_convert (ptrtype, adr);
1550 /* If a bitfield is used in a context where integral promotion
1551 applies, then the caller is expected to have used
1552 default_conversion. That function promotes bitfields correctly
1553 before calling this function. At this point, if we have a
1554 bitfield referenced, we may assume that is not subject to
1555 promotion, and that, therefore, the type of the resulting rvalue
1556 is the declared type of the bitfield. */
1557 exp = convert_bitfield_to_declared_type (exp);
1559 /* We do not call rvalue() here because we do not want to wrap EXP
1560 in a NON_LVALUE_EXPR. */
1564 Non-class rvalues always have cv-unqualified types. */
1565 type = TREE_TYPE (exp);
1566 if (!CLASS_TYPE_P (type) && cp_type_quals (type))
1567 exp = build_nop (TYPE_MAIN_VARIANT (type), exp);
1572 /* Perform prepatory conversions, as part of the "usual arithmetic
1573 conversions". In particular, as per [expr]:
1575 Whenever an lvalue expression appears as an operand of an
1576 operator that expects the rvalue for that operand, the
1577 lvalue-to-rvalue, array-to-pointer, or function-to-pointer
1578 standard conversions are applied to convert the expression to an
1581 In addition, we perform integral promotions here, as those are
1582 applied to both operands to a binary operator before determining
1583 what additional conversions should apply. */
1586 default_conversion (tree exp)
1588 /* Perform the integral promotions first so that bitfield
1589 expressions (which may promote to "int", even if the bitfield is
1590 declared "unsigned") are promoted correctly. */
1591 if (INTEGRAL_OR_ENUMERATION_TYPE_P (TREE_TYPE (exp)))
1592 exp = perform_integral_promotions (exp);
1593 /* Perform the other conversions. */
1594 exp = decay_conversion (exp);
1599 /* EXPR is an expression with an integral or enumeration type.
1600 Perform the integral promotions in [conv.prom], and return the
1604 perform_integral_promotions (tree expr)
1611 If the bitfield has an enumerated type, it is treated as any
1612 other value of that type for promotion purposes. */
1613 type = is_bitfield_expr_with_lowered_type (expr);
1614 if (!type || TREE_CODE (type) != ENUMERAL_TYPE)
1615 type = TREE_TYPE (expr);
1616 gcc_assert (INTEGRAL_OR_ENUMERATION_TYPE_P (type));
1617 promoted_type = type_promotes_to (type);
1618 if (type != promoted_type)
1619 expr = cp_convert (promoted_type, expr);
1623 /* Take the address of an inline function without setting TREE_ADDRESSABLE
1627 inline_conversion (tree exp)
1629 if (TREE_CODE (exp) == FUNCTION_DECL)
1630 exp = build1 (ADDR_EXPR, build_pointer_type (TREE_TYPE (exp)), exp);
1635 /* Returns nonzero iff exp is a STRING_CST or the result of applying
1636 decay_conversion to one. */
1639 string_conv_p (tree totype, tree exp, int warn)
1643 if (TREE_CODE (totype) != POINTER_TYPE)
1646 t = TREE_TYPE (totype);
1647 if (!same_type_p (t, char_type_node)
1648 && !same_type_p (t, wchar_type_node))
1651 if (TREE_CODE (exp) == STRING_CST)
1653 /* Make sure that we don't try to convert between char and wchar_t. */
1654 if (!same_type_p (TYPE_MAIN_VARIANT (TREE_TYPE (TREE_TYPE (exp))), t))
1659 /* Is this a string constant which has decayed to 'const char *'? */
1660 t = build_pointer_type (build_qualified_type (t, TYPE_QUAL_CONST));
1661 if (!same_type_p (TREE_TYPE (exp), t))
1664 if (TREE_CODE (exp) != ADDR_EXPR
1665 || TREE_CODE (TREE_OPERAND (exp, 0)) != STRING_CST)
1669 /* This warning is not very useful, as it complains about printf. */
1671 warning (OPT_Wwrite_strings,
1672 "deprecated conversion from string constant to %qT",
1678 /* Given a COND_EXPR, MIN_EXPR, or MAX_EXPR in T, return it in a form that we
1679 can, for example, use as an lvalue. This code used to be in
1680 unary_complex_lvalue, but we needed it to deal with `a = (d == c) ? b : c'
1681 expressions, where we're dealing with aggregates. But now it's again only
1682 called from unary_complex_lvalue. The case (in particular) that led to
1683 this was with CODE == ADDR_EXPR, since it's not an lvalue when we'd
1687 rationalize_conditional_expr (enum tree_code code, tree t)
1689 /* For MIN_EXPR or MAX_EXPR, fold-const.c has arranged things so that
1690 the first operand is always the one to be used if both operands
1691 are equal, so we know what conditional expression this used to be. */
1692 if (TREE_CODE (t) == MIN_EXPR || TREE_CODE (t) == MAX_EXPR)
1694 tree op0 = TREE_OPERAND (t, 0);
1695 tree op1 = TREE_OPERAND (t, 1);
1697 /* The following code is incorrect if either operand side-effects. */
1698 gcc_assert (!TREE_SIDE_EFFECTS (op0)
1699 && !TREE_SIDE_EFFECTS (op1));
1701 build_conditional_expr (build_x_binary_op ((TREE_CODE (t) == MIN_EXPR
1702 ? LE_EXPR : GE_EXPR),
1703 op0, TREE_CODE (op0),
1704 op1, TREE_CODE (op1),
1705 /*overloaded_p=*/NULL),
1706 build_unary_op (code, op0, 0),
1707 build_unary_op (code, op1, 0));
1711 build_conditional_expr (TREE_OPERAND (t, 0),
1712 build_unary_op (code, TREE_OPERAND (t, 1), 0),
1713 build_unary_op (code, TREE_OPERAND (t, 2), 0));
1716 /* Given the TYPE of an anonymous union field inside T, return the
1717 FIELD_DECL for the field. If not found return NULL_TREE. Because
1718 anonymous unions can nest, we must also search all anonymous unions
1719 that are directly reachable. */
1722 lookup_anon_field (tree t, tree type)
1726 for (field = TYPE_FIELDS (t); field; field = TREE_CHAIN (field))
1728 if (TREE_STATIC (field))
1730 if (TREE_CODE (field) != FIELD_DECL || DECL_ARTIFICIAL (field))
1733 /* If we find it directly, return the field. */
1734 if (DECL_NAME (field) == NULL_TREE
1735 && type == TYPE_MAIN_VARIANT (TREE_TYPE (field)))
1740 /* Otherwise, it could be nested, search harder. */
1741 if (DECL_NAME (field) == NULL_TREE
1742 && ANON_AGGR_TYPE_P (TREE_TYPE (field)))
1744 tree subfield = lookup_anon_field (TREE_TYPE (field), type);
1752 /* Build an expression representing OBJECT.MEMBER. OBJECT is an
1753 expression; MEMBER is a DECL or baselink. If ACCESS_PATH is
1754 non-NULL, it indicates the path to the base used to name MEMBER.
1755 If PRESERVE_REFERENCE is true, the expression returned will have
1756 REFERENCE_TYPE if the MEMBER does. Otherwise, the expression
1757 returned will have the type referred to by the reference.
1759 This function does not perform access control; that is either done
1760 earlier by the parser when the name of MEMBER is resolved to MEMBER
1761 itself, or later when overload resolution selects one of the
1762 functions indicated by MEMBER. */
1765 build_class_member_access_expr (tree object, tree member,
1766 tree access_path, bool preserve_reference)
1770 tree result = NULL_TREE;
1772 if (error_operand_p (object) || error_operand_p (member))
1773 return error_mark_node;
1775 gcc_assert (DECL_P (member) || BASELINK_P (member));
1779 The type of the first expression shall be "class object" (of a
1781 object_type = TREE_TYPE (object);
1782 if (!currently_open_class (object_type)
1783 && !complete_type_or_else (object_type, object))
1784 return error_mark_node;
1785 if (!CLASS_TYPE_P (object_type))
1787 error ("request for member %qD in %qE, which is of non-class type %qT",
1788 member, object, object_type);
1789 return error_mark_node;
1792 /* The standard does not seem to actually say that MEMBER must be a
1793 member of OBJECT_TYPE. However, that is clearly what is
1795 if (DECL_P (member))
1797 member_scope = DECL_CLASS_CONTEXT (member);
1799 if (TREE_DEPRECATED (member))
1800 warn_deprecated_use (member);
1803 member_scope = BINFO_TYPE (BASELINK_BINFO (member));
1804 /* If MEMBER is from an anonymous aggregate, MEMBER_SCOPE will
1805 presently be the anonymous union. Go outwards until we find a
1806 type related to OBJECT_TYPE. */
1807 while (ANON_AGGR_TYPE_P (member_scope)
1808 && !same_type_ignoring_top_level_qualifiers_p (member_scope,
1810 member_scope = TYPE_CONTEXT (member_scope);
1811 if (!member_scope || !DERIVED_FROM_P (member_scope, object_type))
1813 if (TREE_CODE (member) == FIELD_DECL)
1814 error ("invalid use of nonstatic data member %qE", member);
1816 error ("%qD is not a member of %qT", member, object_type);
1817 return error_mark_node;
1820 /* Transform `(a, b).x' into `(*(a, &b)).x', `(a ? b : c).x' into
1821 `(*(a ? &b : &c)).x', and so on. A COND_EXPR is only an lvalue
1822 in the front end; only _DECLs and _REFs are lvalues in the back end. */
1824 tree temp = unary_complex_lvalue (ADDR_EXPR, object);
1826 object = build_indirect_ref (temp, NULL);
1829 /* In [expr.ref], there is an explicit list of the valid choices for
1830 MEMBER. We check for each of those cases here. */
1831 if (TREE_CODE (member) == VAR_DECL)
1833 /* A static data member. */
1835 /* If OBJECT has side-effects, they are supposed to occur. */
1836 if (TREE_SIDE_EFFECTS (object))
1837 result = build2 (COMPOUND_EXPR, TREE_TYPE (result), object, result);
1839 else if (TREE_CODE (member) == FIELD_DECL)
1841 /* A non-static data member. */
1846 null_object_p = (TREE_CODE (object) == INDIRECT_REF
1847 && integer_zerop (TREE_OPERAND (object, 0)));
1849 /* Convert OBJECT to the type of MEMBER. */
1850 if (!same_type_p (TYPE_MAIN_VARIANT (object_type),
1851 TYPE_MAIN_VARIANT (member_scope)))
1856 binfo = lookup_base (access_path ? access_path : object_type,
1857 member_scope, ba_unique, &kind);
1858 if (binfo == error_mark_node)
1859 return error_mark_node;
1861 /* It is invalid to try to get to a virtual base of a
1862 NULL object. The most common cause is invalid use of
1864 if (null_object_p && kind == bk_via_virtual)
1866 error ("invalid access to non-static data member %qD of "
1869 error ("(perhaps the %<offsetof%> macro was used incorrectly)");
1870 return error_mark_node;
1873 /* Convert to the base. */
1874 object = build_base_path (PLUS_EXPR, object, binfo,
1876 /* If we found the base successfully then we should be able
1877 to convert to it successfully. */
1878 gcc_assert (object != error_mark_node);
1881 /* Complain about other invalid uses of offsetof, even though they will
1882 give the right answer. Note that we complain whether or not they
1883 actually used the offsetof macro, since there's no way to know at this
1884 point. So we just give a warning, instead of a pedwarn. */
1885 /* Do not produce this warning for base class field references, because
1886 we know for a fact that didn't come from offsetof. This does occur
1887 in various testsuite cases where a null object is passed where a
1888 vtable access is required. */
1889 if (null_object_p && warn_invalid_offsetof
1890 && CLASSTYPE_NON_POD_P (object_type)
1891 && !DECL_FIELD_IS_BASE (member)
1892 && !skip_evaluation)
1894 warning (0, "invalid access to non-static data member %qD of NULL object",
1896 warning (0, "(perhaps the %<offsetof%> macro was used incorrectly)");
1899 /* If MEMBER is from an anonymous aggregate, we have converted
1900 OBJECT so that it refers to the class containing the
1901 anonymous union. Generate a reference to the anonymous union
1902 itself, and recur to find MEMBER. */
1903 if (ANON_AGGR_TYPE_P (DECL_CONTEXT (member))
1904 /* When this code is called from build_field_call, the
1905 object already has the type of the anonymous union.
1906 That is because the COMPONENT_REF was already
1907 constructed, and was then disassembled before calling
1908 build_field_call. After the function-call code is
1909 cleaned up, this waste can be eliminated. */
1910 && (!same_type_ignoring_top_level_qualifiers_p
1911 (TREE_TYPE (object), DECL_CONTEXT (member))))
1913 tree anonymous_union;
1915 anonymous_union = lookup_anon_field (TREE_TYPE (object),
1916 DECL_CONTEXT (member));
1917 object = build_class_member_access_expr (object,
1919 /*access_path=*/NULL_TREE,
1920 preserve_reference);
1923 /* Compute the type of the field, as described in [expr.ref]. */
1924 type_quals = TYPE_UNQUALIFIED;
1925 member_type = TREE_TYPE (member);
1926 if (TREE_CODE (member_type) != REFERENCE_TYPE)
1928 type_quals = (cp_type_quals (member_type)
1929 | cp_type_quals (object_type));
1931 /* A field is const (volatile) if the enclosing object, or the
1932 field itself, is const (volatile). But, a mutable field is
1933 not const, even within a const object. */
1934 if (DECL_MUTABLE_P (member))
1935 type_quals &= ~TYPE_QUAL_CONST;
1936 member_type = cp_build_qualified_type (member_type, type_quals);
1939 result = build3 (COMPONENT_REF, member_type, object, member,
1941 result = fold_if_not_in_template (result);
1943 /* Mark the expression const or volatile, as appropriate. Even
1944 though we've dealt with the type above, we still have to mark the
1945 expression itself. */
1946 if (type_quals & TYPE_QUAL_CONST)
1947 TREE_READONLY (result) = 1;
1948 if (type_quals & TYPE_QUAL_VOLATILE)
1949 TREE_THIS_VOLATILE (result) = 1;
1951 else if (BASELINK_P (member))
1953 /* The member is a (possibly overloaded) member function. */
1957 /* If the MEMBER is exactly one static member function, then we
1958 know the type of the expression. Otherwise, we must wait
1959 until overload resolution has been performed. */
1960 functions = BASELINK_FUNCTIONS (member);
1961 if (TREE_CODE (functions) == FUNCTION_DECL
1962 && DECL_STATIC_FUNCTION_P (functions))
1963 type = TREE_TYPE (functions);
1965 type = unknown_type_node;
1966 /* Note that we do not convert OBJECT to the BASELINK_BINFO
1967 base. That will happen when the function is called. */
1968 result = build3 (COMPONENT_REF, type, object, member, NULL_TREE);
1970 else if (TREE_CODE (member) == CONST_DECL)
1972 /* The member is an enumerator. */
1974 /* If OBJECT has side-effects, they are supposed to occur. */
1975 if (TREE_SIDE_EFFECTS (object))
1976 result = build2 (COMPOUND_EXPR, TREE_TYPE (result),
1981 error ("invalid use of %qD", member);
1982 return error_mark_node;
1985 if (!preserve_reference)
1988 If E2 is declared to have type "reference to T", then ... the
1989 type of E1.E2 is T. */
1990 result = convert_from_reference (result);
1995 /* Return the destructor denoted by OBJECT.SCOPE::~DTOR_NAME, or, if
1996 SCOPE is NULL, by OBJECT.~DTOR_NAME. */
1999 lookup_destructor (tree object, tree scope, tree dtor_name)
2001 tree object_type = TREE_TYPE (object);
2002 tree dtor_type = TREE_OPERAND (dtor_name, 0);
2005 if (scope && !check_dtor_name (scope, dtor_type))
2007 error ("qualified type %qT does not match destructor name ~%qT",
2009 return error_mark_node;
2011 if (!DERIVED_FROM_P (dtor_type, TYPE_MAIN_VARIANT (object_type)))
2013 error ("the type being destroyed is %qT, but the destructor refers to %qT",
2014 TYPE_MAIN_VARIANT (object_type), dtor_type);
2015 return error_mark_node;
2017 expr = lookup_member (dtor_type, complete_dtor_identifier,
2018 /*protect=*/1, /*want_type=*/false);
2019 expr = (adjust_result_of_qualified_name_lookup
2020 (expr, dtor_type, object_type));
2024 /* An expression of the form "A::template B" has been resolved to
2025 DECL. Issue a diagnostic if B is not a template or template
2029 check_template_keyword (tree decl)
2031 /* The standard says:
2035 If a name prefixed by the keyword template is not a member
2036 template, the program is ill-formed.
2038 DR 228 removed the restriction that the template be a member
2041 DR 96, if accepted would add the further restriction that explicit
2042 template arguments must be provided if the template keyword is
2043 used, but, as of 2005-10-16, that DR is still in "drafting". If
2044 this DR is accepted, then the semantic checks here can be
2045 simplified, as the entity named must in fact be a template
2046 specialization, rather than, as at present, a set of overloaded
2047 functions containing at least one template function. */
2048 if (TREE_CODE (decl) != TEMPLATE_DECL
2049 && TREE_CODE (decl) != TEMPLATE_ID_EXPR)
2051 if (!is_overloaded_fn (decl))
2052 pedwarn ("%qD is not a template", decl);
2057 if (BASELINK_P (fns))
2058 fns = BASELINK_FUNCTIONS (fns);
2061 tree fn = OVL_CURRENT (fns);
2062 if (TREE_CODE (fn) == TEMPLATE_DECL
2063 || TREE_CODE (fn) == TEMPLATE_ID_EXPR)
2065 if (TREE_CODE (fn) == FUNCTION_DECL
2066 && DECL_USE_TEMPLATE (fn)
2067 && PRIMARY_TEMPLATE_P (DECL_TI_TEMPLATE (fn)))
2069 fns = OVL_NEXT (fns);
2072 pedwarn ("%qD is not a template", decl);
2077 /* This function is called by the parser to process a class member
2078 access expression of the form OBJECT.NAME. NAME is a node used by
2079 the parser to represent a name; it is not yet a DECL. It may,
2080 however, be a BASELINK where the BASELINK_FUNCTIONS is a
2081 TEMPLATE_ID_EXPR. Templates must be looked up by the parser, and
2082 there is no reason to do the lookup twice, so the parser keeps the
2083 BASELINK. TEMPLATE_P is true iff NAME was explicitly declared to
2084 be a template via the use of the "A::template B" syntax. */
2087 finish_class_member_access_expr (tree object, tree name, bool template_p)
2092 tree access_path = NULL_TREE;
2093 tree orig_object = object;
2094 tree orig_name = name;
2096 if (object == error_mark_node || name == error_mark_node)
2097 return error_mark_node;
2099 /* If OBJECT is an ObjC class instance, we must obey ObjC access rules. */
2100 if (!objc_is_public (object, name))
2101 return error_mark_node;
2103 object_type = TREE_TYPE (object);
2105 if (processing_template_decl)
2107 if (/* If OBJECT_TYPE is dependent, so is OBJECT.NAME. */
2108 dependent_type_p (object_type)
2109 /* If NAME is just an IDENTIFIER_NODE, then the expression
2111 || TREE_CODE (object) == IDENTIFIER_NODE
2112 /* If NAME is "f<args>", where either 'f' or 'args' is
2113 dependent, then the expression is dependent. */
2114 || (TREE_CODE (name) == TEMPLATE_ID_EXPR
2115 && dependent_template_id_p (TREE_OPERAND (name, 0),
2116 TREE_OPERAND (name, 1)))
2117 /* If NAME is "T::X" where "T" is dependent, then the
2118 expression is dependent. */
2119 || (TREE_CODE (name) == SCOPE_REF
2120 && TYPE_P (TREE_OPERAND (name, 0))
2121 && dependent_type_p (TREE_OPERAND (name, 0))))
2122 return build_min_nt (COMPONENT_REF, object, name, NULL_TREE);
2123 object = build_non_dependent_expr (object);
2128 The type of the first expression shall be "class object" (of a
2130 if (!currently_open_class (object_type)
2131 && !complete_type_or_else (object_type, object))
2132 return error_mark_node;
2133 if (!CLASS_TYPE_P (object_type))
2135 error ("request for member %qD in %qE, which is of non-class type %qT",
2136 name, object, object_type);
2137 return error_mark_node;
2140 if (BASELINK_P (name))
2141 /* A member function that has already been looked up. */
2145 bool is_template_id = false;
2146 tree template_args = NULL_TREE;
2149 if (TREE_CODE (name) == TEMPLATE_ID_EXPR)
2151 is_template_id = true;
2152 template_args = TREE_OPERAND (name, 1);
2153 name = TREE_OPERAND (name, 0);
2155 if (TREE_CODE (name) == OVERLOAD)
2156 name = DECL_NAME (get_first_fn (name));
2157 else if (DECL_P (name))
2158 name = DECL_NAME (name);
2161 if (TREE_CODE (name) == SCOPE_REF)
2163 /* A qualified name. The qualifying class or namespace `S'
2164 has already been looked up; it is either a TYPE or a
2166 scope = TREE_OPERAND (name, 0);
2167 name = TREE_OPERAND (name, 1);
2169 /* If SCOPE is a namespace, then the qualified name does not
2170 name a member of OBJECT_TYPE. */
2171 if (TREE_CODE (scope) == NAMESPACE_DECL)
2173 error ("%<%D::%D%> is not a member of %qT",
2174 scope, name, object_type);
2175 return error_mark_node;
2178 gcc_assert (CLASS_TYPE_P (scope));
2179 gcc_assert (TREE_CODE (name) == IDENTIFIER_NODE
2180 || TREE_CODE (name) == BIT_NOT_EXPR);
2182 /* Find the base of OBJECT_TYPE corresponding to SCOPE. */
2183 access_path = lookup_base (object_type, scope, ba_check, NULL);
2184 if (access_path == error_mark_node)
2185 return error_mark_node;
2188 error ("%qT is not a base of %qT", scope, object_type);
2189 return error_mark_node;
2195 access_path = object_type;
2198 if (TREE_CODE (name) == BIT_NOT_EXPR)
2199 member = lookup_destructor (object, scope, name);
2202 /* Look up the member. */
2203 member = lookup_member (access_path, name, /*protect=*/1,
2204 /*want_type=*/false);
2205 if (member == NULL_TREE)
2207 error ("%qD has no member named %qE", object_type, name);
2208 return error_mark_node;
2210 if (member == error_mark_node)
2211 return error_mark_node;
2216 tree template = member;
2218 if (BASELINK_P (template))
2219 template = lookup_template_function (template, template_args);
2222 error ("%qD is not a member template function", name);
2223 return error_mark_node;
2228 if (TREE_DEPRECATED (member))
2229 warn_deprecated_use (member);
2232 check_template_keyword (member);
2234 expr = build_class_member_access_expr (object, member, access_path,
2235 /*preserve_reference=*/false);
2236 if (processing_template_decl && expr != error_mark_node)
2238 if (BASELINK_P (member))
2240 if (TREE_CODE (orig_name) == SCOPE_REF)
2241 BASELINK_QUALIFIED_P (member) = 1;
2244 return build_min_non_dep (COMPONENT_REF, expr,
2245 orig_object, orig_name,
2252 /* Return an expression for the MEMBER_NAME field in the internal
2253 representation of PTRMEM, a pointer-to-member function. (Each
2254 pointer-to-member function type gets its own RECORD_TYPE so it is
2255 more convenient to access the fields by name than by FIELD_DECL.)
2256 This routine converts the NAME to a FIELD_DECL and then creates the
2257 node for the complete expression. */
2260 build_ptrmemfunc_access_expr (tree ptrmem, tree member_name)
2266 /* This code is a stripped down version of
2267 build_class_member_access_expr. It does not work to use that
2268 routine directly because it expects the object to be of class
2270 ptrmem_type = TREE_TYPE (ptrmem);
2271 gcc_assert (TYPE_PTRMEMFUNC_P (ptrmem_type));
2272 member = lookup_member (ptrmem_type, member_name, /*protect=*/0,
2273 /*want_type=*/false);
2274 member_type = cp_build_qualified_type (TREE_TYPE (member),
2275 cp_type_quals (ptrmem_type));
2276 return fold_build3 (COMPONENT_REF, member_type,
2277 ptrmem, member, NULL_TREE);
2280 /* Given an expression PTR for a pointer, return an expression
2281 for the value pointed to.
2282 ERRORSTRING is the name of the operator to appear in error messages.
2284 This function may need to overload OPERATOR_FNNAME.
2285 Must also handle REFERENCE_TYPEs for C++. */
2288 build_x_indirect_ref (tree expr, const char *errorstring)
2290 tree orig_expr = expr;
2293 if (processing_template_decl)
2295 if (type_dependent_expression_p (expr))
2296 return build_min_nt (INDIRECT_REF, expr);
2297 expr = build_non_dependent_expr (expr);
2300 rval = build_new_op (INDIRECT_REF, LOOKUP_NORMAL, expr, NULL_TREE,
2301 NULL_TREE, /*overloaded_p=*/NULL);
2303 rval = build_indirect_ref (expr, errorstring);
2305 if (processing_template_decl && rval != error_mark_node)
2306 return build_min_non_dep (INDIRECT_REF, rval, orig_expr);
2312 build_indirect_ref (tree ptr, const char *errorstring)
2316 if (ptr == error_mark_node)
2317 return error_mark_node;
2319 if (ptr == current_class_ptr)
2320 return current_class_ref;
2322 pointer = (TREE_CODE (TREE_TYPE (ptr)) == REFERENCE_TYPE
2323 ? ptr : decay_conversion (ptr));
2324 type = TREE_TYPE (pointer);
2326 if (POINTER_TYPE_P (type))
2330 If the type of the expression is "pointer to T," the type
2331 of the result is "T."
2333 We must use the canonical variant because certain parts of
2334 the back end, like fold, do pointer comparisons between
2336 tree t = canonical_type_variant (TREE_TYPE (type));
2338 if (VOID_TYPE_P (t))
2340 /* A pointer to incomplete type (other than cv void) can be
2341 dereferenced [expr.unary.op]/1 */
2342 error ("%qT is not a pointer-to-object type", type);
2343 return error_mark_node;
2345 else if (TREE_CODE (pointer) == ADDR_EXPR
2346 && same_type_p (t, TREE_TYPE (TREE_OPERAND (pointer, 0))))
2347 /* The POINTER was something like `&x'. We simplify `*&x' to
2349 return TREE_OPERAND (pointer, 0);
2352 tree ref = build1 (INDIRECT_REF, t, pointer);
2354 /* We *must* set TREE_READONLY when dereferencing a pointer to const,
2355 so that we get the proper error message if the result is used
2356 to assign to. Also, &* is supposed to be a no-op. */
2357 TREE_READONLY (ref) = CP_TYPE_CONST_P (t);
2358 TREE_THIS_VOLATILE (ref) = CP_TYPE_VOLATILE_P (t);
2359 TREE_SIDE_EFFECTS (ref)
2360 = (TREE_THIS_VOLATILE (ref) || TREE_SIDE_EFFECTS (pointer));
2364 /* `pointer' won't be an error_mark_node if we were given a
2365 pointer to member, so it's cool to check for this here. */
2366 else if (TYPE_PTR_TO_MEMBER_P (type))
2367 error ("invalid use of %qs on pointer to member", errorstring);
2368 else if (pointer != error_mark_node)
2371 error ("invalid type argument of %qs", errorstring);
2373 error ("invalid type argument");
2375 return error_mark_node;
2378 /* This handles expressions of the form "a[i]", which denotes
2381 This is logically equivalent in C to *(a+i), but we may do it differently.
2382 If A is a variable or a member, we generate a primitive ARRAY_REF.
2383 This avoids forcing the array out of registers, and can work on
2384 arrays that are not lvalues (for example, members of structures returned
2387 If INDEX is of some user-defined type, it must be converted to
2388 integer type. Otherwise, to make a compatible PLUS_EXPR, it
2389 will inherit the type of the array, which will be some pointer type. */
2392 build_array_ref (tree array, tree idx)
2396 error ("subscript missing in array reference");
2397 return error_mark_node;
2400 if (TREE_TYPE (array) == error_mark_node
2401 || TREE_TYPE (idx) == error_mark_node)
2402 return error_mark_node;
2404 /* If ARRAY is a COMPOUND_EXPR or COND_EXPR, move our reference
2406 switch (TREE_CODE (array))
2410 tree value = build_array_ref (TREE_OPERAND (array, 1), idx);
2411 return build2 (COMPOUND_EXPR, TREE_TYPE (value),
2412 TREE_OPERAND (array, 0), value);
2416 return build_conditional_expr
2417 (TREE_OPERAND (array, 0),
2418 build_array_ref (TREE_OPERAND (array, 1), idx),
2419 build_array_ref (TREE_OPERAND (array, 2), idx));
2425 if (TREE_CODE (TREE_TYPE (array)) == ARRAY_TYPE)
2429 warn_array_subscript_with_type_char (idx);
2431 if (!INTEGRAL_OR_ENUMERATION_TYPE_P (TREE_TYPE (idx)))
2433 error ("array subscript is not an integer");
2434 return error_mark_node;
2437 /* Apply integral promotions *after* noticing character types.
2438 (It is unclear why we do these promotions -- the standard
2439 does not say that we should. In fact, the natural thing would
2440 seem to be to convert IDX to ptrdiff_t; we're performing
2441 pointer arithmetic.) */
2442 idx = perform_integral_promotions (idx);
2444 /* An array that is indexed by a non-constant
2445 cannot be stored in a register; we must be able to do
2446 address arithmetic on its address.
2447 Likewise an array of elements of variable size. */
2448 if (TREE_CODE (idx) != INTEGER_CST
2449 || (COMPLETE_TYPE_P (TREE_TYPE (TREE_TYPE (array)))
2450 && (TREE_CODE (TYPE_SIZE (TREE_TYPE (TREE_TYPE (array))))
2453 if (!cxx_mark_addressable (array))
2454 return error_mark_node;
2457 /* An array that is indexed by a constant value which is not within
2458 the array bounds cannot be stored in a register either; because we
2459 would get a crash in store_bit_field/extract_bit_field when trying
2460 to access a non-existent part of the register. */
2461 if (TREE_CODE (idx) == INTEGER_CST
2462 && TYPE_DOMAIN (TREE_TYPE (array))
2463 && ! int_fits_type_p (idx, TYPE_DOMAIN (TREE_TYPE (array))))
2465 if (!cxx_mark_addressable (array))
2466 return error_mark_node;
2469 if (pedantic && !lvalue_p (array))
2470 pedwarn ("ISO C++ forbids subscripting non-lvalue array");
2472 /* Note in C++ it is valid to subscript a `register' array, since
2473 it is valid to take the address of something with that
2474 storage specification. */
2478 while (TREE_CODE (foo) == COMPONENT_REF)
2479 foo = TREE_OPERAND (foo, 0);
2480 if (TREE_CODE (foo) == VAR_DECL && DECL_REGISTER (foo))
2481 warning (OPT_Wextra, "subscripting array declared %<register%>");
2484 type = TREE_TYPE (TREE_TYPE (array));
2485 rval = build4 (ARRAY_REF, type, array, idx, NULL_TREE, NULL_TREE);
2486 /* Array ref is const/volatile if the array elements are
2487 or if the array is.. */
2488 TREE_READONLY (rval)
2489 |= (CP_TYPE_CONST_P (type) | TREE_READONLY (array));
2490 TREE_SIDE_EFFECTS (rval)
2491 |= (CP_TYPE_VOLATILE_P (type) | TREE_SIDE_EFFECTS (array));
2492 TREE_THIS_VOLATILE (rval)
2493 |= (CP_TYPE_VOLATILE_P (type) | TREE_THIS_VOLATILE (array));
2494 return require_complete_type (fold_if_not_in_template (rval));
2498 tree ar = default_conversion (array);
2499 tree ind = default_conversion (idx);
2501 /* Put the integer in IND to simplify error checking. */
2502 if (TREE_CODE (TREE_TYPE (ar)) == INTEGER_TYPE)
2509 if (ar == error_mark_node)
2512 if (TREE_CODE (TREE_TYPE (ar)) != POINTER_TYPE)
2514 error ("subscripted value is neither array nor pointer");
2515 return error_mark_node;
2517 if (TREE_CODE (TREE_TYPE (ind)) != INTEGER_TYPE)
2519 error ("array subscript is not an integer");
2520 return error_mark_node;
2523 warn_array_subscript_with_type_char (idx);
2525 return build_indirect_ref (cp_build_binary_op (PLUS_EXPR, ar, ind),
2530 /* Resolve a pointer to member function. INSTANCE is the object
2531 instance to use, if the member points to a virtual member.
2533 This used to avoid checking for virtual functions if basetype
2534 has no virtual functions, according to an earlier ANSI draft.
2535 With the final ISO C++ rules, such an optimization is
2536 incorrect: A pointer to a derived member can be static_cast
2537 to pointer-to-base-member, as long as the dynamic object
2538 later has the right member. */
2541 get_member_function_from_ptrfunc (tree *instance_ptrptr, tree function)
2543 if (TREE_CODE (function) == OFFSET_REF)
2544 function = TREE_OPERAND (function, 1);
2546 if (TYPE_PTRMEMFUNC_P (TREE_TYPE (function)))
2548 tree idx, delta, e1, e2, e3, vtbl, basetype;
2549 tree fntype = TYPE_PTRMEMFUNC_FN_TYPE (TREE_TYPE (function));
2551 tree instance_ptr = *instance_ptrptr;
2552 tree instance_save_expr = 0;
2553 if (instance_ptr == error_mark_node)
2555 if (TREE_CODE (function) == PTRMEM_CST)
2557 /* Extracting the function address from a pmf is only
2558 allowed with -Wno-pmf-conversions. It only works for
2560 e1 = build_addr_func (PTRMEM_CST_MEMBER (function));
2561 e1 = convert (fntype, e1);
2566 error ("object missing in use of %qE", function);
2567 return error_mark_node;
2571 if (TREE_SIDE_EFFECTS (instance_ptr))
2572 instance_ptr = instance_save_expr = save_expr (instance_ptr);
2574 if (TREE_SIDE_EFFECTS (function))
2575 function = save_expr (function);
2577 /* Start by extracting all the information from the PMF itself. */
2578 e3 = pfn_from_ptrmemfunc (function);
2579 delta = build_ptrmemfunc_access_expr (function, delta_identifier);
2580 idx = build1 (NOP_EXPR, vtable_index_type, e3);
2581 switch (TARGET_PTRMEMFUNC_VBIT_LOCATION)
2583 case ptrmemfunc_vbit_in_pfn:
2584 e1 = cp_build_binary_op (BIT_AND_EXPR, idx, integer_one_node);
2585 idx = cp_build_binary_op (MINUS_EXPR, idx, integer_one_node);
2588 case ptrmemfunc_vbit_in_delta:
2589 e1 = cp_build_binary_op (BIT_AND_EXPR, delta, integer_one_node);
2590 delta = cp_build_binary_op (RSHIFT_EXPR, delta, integer_one_node);
2597 /* Convert down to the right base before using the instance. A
2598 special case is that in a pointer to member of class C, C may
2599 be incomplete. In that case, the function will of course be
2600 a member of C, and no conversion is required. In fact,
2601 lookup_base will fail in that case, because incomplete
2602 classes do not have BINFOs. */
2603 basetype = TYPE_METHOD_BASETYPE (TREE_TYPE (fntype));
2604 if (!same_type_ignoring_top_level_qualifiers_p
2605 (basetype, TREE_TYPE (TREE_TYPE (instance_ptr))))
2607 basetype = lookup_base (TREE_TYPE (TREE_TYPE (instance_ptr)),
2608 basetype, ba_check, NULL);
2609 instance_ptr = build_base_path (PLUS_EXPR, instance_ptr, basetype,
2611 if (instance_ptr == error_mark_node)
2612 return error_mark_node;
2614 /* ...and then the delta in the PMF. */
2615 instance_ptr = build2 (PLUS_EXPR, TREE_TYPE (instance_ptr),
2616 instance_ptr, delta);
2618 /* Hand back the adjusted 'this' argument to our caller. */
2619 *instance_ptrptr = instance_ptr;
2621 /* Next extract the vtable pointer from the object. */
2622 vtbl = build1 (NOP_EXPR, build_pointer_type (vtbl_ptr_type_node),
2624 vtbl = build_indirect_ref (vtbl, NULL);
2626 /* Finally, extract the function pointer from the vtable. */
2627 e2 = fold_build2 (PLUS_EXPR, TREE_TYPE (vtbl), vtbl, idx);
2628 e2 = build_indirect_ref (e2, NULL);
2629 TREE_CONSTANT (e2) = 1;
2630 TREE_INVARIANT (e2) = 1;
2632 /* When using function descriptors, the address of the
2633 vtable entry is treated as a function pointer. */
2634 if (TARGET_VTABLE_USES_DESCRIPTORS)
2635 e2 = build1 (NOP_EXPR, TREE_TYPE (e2),
2636 build_unary_op (ADDR_EXPR, e2, /*noconvert=*/1));
2638 TREE_TYPE (e2) = TREE_TYPE (e3);
2639 e1 = build_conditional_expr (e1, e2, e3);
2641 /* Make sure this doesn't get evaluated first inside one of the
2642 branches of the COND_EXPR. */
2643 if (instance_save_expr)
2644 e1 = build2 (COMPOUND_EXPR, TREE_TYPE (e1),
2645 instance_save_expr, e1);
2653 build_function_call (tree function, tree params)
2655 tree fntype, fndecl;
2656 tree name = NULL_TREE;
2658 tree original = function;
2659 int nargs, parm_types_len;
2663 /* For Objective-C, convert any calls via a cast to OBJC_TYPE_REF
2664 expressions, like those used for ObjC messenger dispatches. */
2665 function = objc_rewrite_function_call (function, params);
2667 /* build_c_cast puts on a NOP_EXPR to make the result not an lvalue.
2668 Strip such NOP_EXPRs, since FUNCTION is used in non-lvalue context. */
2669 if (TREE_CODE (function) == NOP_EXPR
2670 && TREE_TYPE (function) == TREE_TYPE (TREE_OPERAND (function, 0)))
2671 function = TREE_OPERAND (function, 0);
2673 if (TREE_CODE (function) == FUNCTION_DECL)
2675 name = DECL_NAME (function);
2677 mark_used (function);
2680 /* Convert anything with function type to a pointer-to-function. */
2681 if (pedantic && DECL_MAIN_P (function))
2682 pedwarn ("ISO C++ forbids calling %<::main%> from within program");
2684 /* Differs from default_conversion by not setting TREE_ADDRESSABLE
2685 (because calling an inline function does not mean the function
2686 needs to be separately compiled). */
2688 if (DECL_INLINE (function))
2689 function = inline_conversion (function);
2691 function = build_addr_func (function);
2697 function = build_addr_func (function);
2700 if (function == error_mark_node)
2701 return error_mark_node;
2703 fntype = TREE_TYPE (function);
2705 if (TYPE_PTRMEMFUNC_P (fntype))
2707 error ("must use %<.*%> or %<->*%> to call pointer-to-member "
2708 "function in %<%E (...)%>",
2710 return error_mark_node;
2713 is_method = (TREE_CODE (fntype) == POINTER_TYPE
2714 && TREE_CODE (TREE_TYPE (fntype)) == METHOD_TYPE);
2716 if (!((TREE_CODE (fntype) == POINTER_TYPE
2717 && TREE_CODE (TREE_TYPE (fntype)) == FUNCTION_TYPE)
2719 || TREE_CODE (function) == TEMPLATE_ID_EXPR))
2721 error ("%qE cannot be used as a function", original);
2722 return error_mark_node;
2725 /* fntype now gets the type of function pointed to. */
2726 fntype = TREE_TYPE (fntype);
2727 parm_types = TYPE_ARG_TYPES (fntype);
2729 /* Allocate storage for converted arguments. */
2730 parm_types_len = list_length (parm_types);
2731 nargs = list_length (params);
2732 if (parm_types_len > nargs)
2733 nargs = parm_types_len;
2734 argarray = (tree *) alloca (nargs * sizeof (tree));
2736 /* Convert the parameters to the types declared in the
2737 function prototype, or apply default promotions. */
2738 nargs = convert_arguments (nargs, argarray, parm_types,
2739 params, fndecl, LOOKUP_NORMAL);
2741 return error_mark_node;
2743 /* Check for errors in format strings and inappropriately
2746 check_function_arguments (TYPE_ATTRIBUTES (fntype), nargs, argarray,
2749 return build_cxx_call (function, nargs, argarray);
2752 /* Convert the actual parameter expressions in the list VALUES
2753 to the types in the list TYPELIST.
2754 If parmdecls is exhausted, or when an element has NULL as its type,
2755 perform the default conversions.
2757 Store the converted arguments in ARGARRAY. NARGS is the size of this array.
2759 NAME is an IDENTIFIER_NODE or 0. It is used only for error messages.
2761 This is also where warnings about wrong number of args are generated.
2763 Returns the actual number of arguments processed (which might be less
2764 than NARGS), or -1 on error.
2766 VALUES is a chain of TREE_LIST nodes with the elements of the list
2767 in the TREE_VALUE slots of those nodes.
2769 In C++, unspecified trailing parameters can be filled in with their
2770 default arguments, if such were specified. Do so here. */
2773 convert_arguments (int nargs, tree *argarray,
2774 tree typelist, tree values, tree fndecl, int flags)
2776 tree typetail, valtail;
2777 const char *called_thing = 0;
2780 /* Argument passing is always copy-initialization. */
2781 flags |= LOOKUP_ONLYCONVERTING;
2785 if (TREE_CODE (TREE_TYPE (fndecl)) == METHOD_TYPE)
2787 if (DECL_NAME (fndecl) == NULL_TREE
2788 || IDENTIFIER_HAS_TYPE_VALUE (DECL_NAME (fndecl)))
2789 called_thing = "constructor";
2791 called_thing = "member function";
2794 called_thing = "function";
2797 for (valtail = values, typetail = typelist;
2799 valtail = TREE_CHAIN (valtail), i++)
2801 tree type = typetail ? TREE_VALUE (typetail) : 0;
2802 tree val = TREE_VALUE (valtail);
2804 if (val == error_mark_node || type == error_mark_node)
2807 if (type == void_type_node)
2811 error ("too many arguments to %s %q+#D", called_thing, fndecl);
2812 error ("at this point in file");
2815 error ("too many arguments to function");
2819 /* build_c_cast puts on a NOP_EXPR to make the result not an lvalue.
2820 Strip such NOP_EXPRs, since VAL is used in non-lvalue context. */
2821 if (TREE_CODE (val) == NOP_EXPR
2822 && TREE_TYPE (val) == TREE_TYPE (TREE_OPERAND (val, 0))
2823 && (type == 0 || TREE_CODE (type) != REFERENCE_TYPE))
2824 val = TREE_OPERAND (val, 0);
2826 if (type == 0 || TREE_CODE (type) != REFERENCE_TYPE)
2828 if (TREE_CODE (TREE_TYPE (val)) == ARRAY_TYPE
2829 || TREE_CODE (TREE_TYPE (val)) == FUNCTION_TYPE
2830 || TREE_CODE (TREE_TYPE (val)) == METHOD_TYPE)
2831 val = decay_conversion (val);
2834 if (val == error_mark_node)
2839 /* Formal parm type is specified by a function prototype. */
2842 if (!COMPLETE_TYPE_P (complete_type (type)))
2845 error ("parameter %P of %qD has incomplete type %qT",
2848 error ("parameter %P has incomplete type %qT", i, type);
2849 parmval = error_mark_node;
2853 parmval = convert_for_initialization
2854 (NULL_TREE, type, val, flags,
2855 "argument passing", fndecl, i);
2856 parmval = convert_for_arg_passing (type, parmval);
2859 if (parmval == error_mark_node)
2862 argarray[i] = parmval;
2866 if (fndecl && DECL_BUILT_IN (fndecl)
2867 && DECL_FUNCTION_CODE (fndecl) == BUILT_IN_CONSTANT_P)
2868 /* Don't do ellipsis conversion for __built_in_constant_p
2869 as this will result in spurious warnings for non-POD
2871 val = require_complete_type (val);
2873 val = convert_arg_to_ellipsis (val);
2879 typetail = TREE_CHAIN (typetail);
2882 if (typetail != 0 && typetail != void_list_node)
2884 /* See if there are default arguments that can be used. */
2885 if (TREE_PURPOSE (typetail)
2886 && TREE_CODE (TREE_PURPOSE (typetail)) != DEFAULT_ARG)
2888 for (; typetail != void_list_node; ++i)
2891 = convert_default_arg (TREE_VALUE (typetail),
2892 TREE_PURPOSE (typetail),
2895 if (parmval == error_mark_node)
2898 argarray[i] = parmval;
2899 typetail = TREE_CHAIN (typetail);
2900 /* ends with `...'. */
2901 if (typetail == NULL_TREE)
2909 error ("too few arguments to %s %q+#D", called_thing, fndecl);
2910 error ("at this point in file");
2913 error ("too few arguments to function");
2918 gcc_assert (i <= nargs);
2922 /* Build a binary-operation expression, after performing default
2923 conversions on the operands. CODE is the kind of expression to
2924 build. ARG1 and ARG2 are the arguments. ARG1_CODE and ARG2_CODE
2925 are the tree codes which correspond to ARG1 and ARG2 when issuing
2926 warnings about possibly misplaced parentheses. They may differ
2927 from the TREE_CODE of ARG1 and ARG2 if the parser has done constant
2928 folding (e.g., if the parser sees "a | 1 + 1", it may call this
2929 routine with ARG2 being an INTEGER_CST and ARG2_CODE == PLUS_EXPR).
2930 To avoid issuing any parentheses warnings, pass ARG1_CODE and/or
2931 ARG2_CODE as ERROR_MARK. */
2934 build_x_binary_op (enum tree_code code, tree arg1, enum tree_code arg1_code,
2935 tree arg2, enum tree_code arg2_code, bool *overloaded_p)
2944 if (processing_template_decl)
2946 if (type_dependent_expression_p (arg1)
2947 || type_dependent_expression_p (arg2))
2948 return build_min_nt (code, arg1, arg2);
2949 arg1 = build_non_dependent_expr (arg1);
2950 arg2 = build_non_dependent_expr (arg2);
2953 if (code == DOTSTAR_EXPR)
2954 expr = build_m_component_ref (arg1, arg2);
2956 expr = build_new_op (code, LOOKUP_NORMAL, arg1, arg2, NULL_TREE,
2959 /* Check for cases such as x+y<<z which users are likely to
2960 misinterpret. But don't warn about obj << x + y, since that is a
2961 common idiom for I/O. */
2962 if (warn_parentheses
2963 && !processing_template_decl
2964 && !error_operand_p (arg1)
2965 && !error_operand_p (arg2)
2966 && (code != LSHIFT_EXPR
2967 || !CLASS_TYPE_P (TREE_TYPE (arg1))))
2968 warn_about_parentheses (code, arg1_code, arg2_code);
2970 if (processing_template_decl && expr != error_mark_node)
2971 return build_min_non_dep (code, expr, orig_arg1, orig_arg2);
2976 /* Build a binary-operation expression without default conversions.
2977 CODE is the kind of expression to build.
2978 This function differs from `build' in several ways:
2979 the data type of the result is computed and recorded in it,
2980 warnings are generated if arg data types are invalid,
2981 special handling for addition and subtraction of pointers is known,
2982 and some optimization is done (operations on narrow ints
2983 are done in the narrower type when that gives the same result).
2984 Constant folding is also done before the result is returned.
2986 Note that the operands will never have enumeral types
2987 because either they have just had the default conversions performed
2988 or they have both just been converted to some other type in which
2989 the arithmetic is to be done.
2991 C++: must do special pointer arithmetic when implementing
2992 multiple inheritance, and deal with pointer to member functions. */
2995 build_binary_op (enum tree_code code, tree orig_op0, tree orig_op1,
2996 int convert_p ATTRIBUTE_UNUSED)
2999 enum tree_code code0, code1;
3001 const char *invalid_op_diag;
3003 /* Expression code to give to the expression when it is built.
3004 Normally this is CODE, which is what the caller asked for,
3005 but in some special cases we change it. */
3006 enum tree_code resultcode = code;
3008 /* Data type in which the computation is to be performed.
3009 In the simplest cases this is the common type of the arguments. */
3010 tree result_type = NULL;
3012 /* Nonzero means operands have already been type-converted
3013 in whatever way is necessary.
3014 Zero means they need to be converted to RESULT_TYPE. */
3017 /* Nonzero means create the expression with this type, rather than
3019 tree build_type = 0;
3021 /* Nonzero means after finally constructing the expression
3022 convert it to this type. */
3023 tree final_type = 0;
3027 /* Nonzero if this is an operation like MIN or MAX which can
3028 safely be computed in short if both args are promoted shorts.
3029 Also implies COMMON.
3030 -1 indicates a bitwise operation; this makes a difference
3031 in the exact conditions for when it is safe to do the operation
3032 in a narrower mode. */
3035 /* Nonzero if this is a comparison operation;
3036 if both args are promoted shorts, compare the original shorts.
3037 Also implies COMMON. */
3038 int short_compare = 0;
3040 /* Nonzero if this is a right-shift operation, which can be computed on the
3041 original short and then promoted if the operand is a promoted short. */
3042 int short_shift = 0;
3044 /* Nonzero means set RESULT_TYPE to the common type of the args. */
3047 /* True if both operands have arithmetic type. */
3048 bool arithmetic_types_p;
3050 /* Apply default conversions. */
3054 if (code == TRUTH_AND_EXPR || code == TRUTH_ANDIF_EXPR
3055 || code == TRUTH_OR_EXPR || code == TRUTH_ORIF_EXPR
3056 || code == TRUTH_XOR_EXPR)
3058 if (!really_overloaded_fn (op0))
3059 op0 = decay_conversion (op0);
3060 if (!really_overloaded_fn (op1))
3061 op1 = decay_conversion (op1);
3065 if (!really_overloaded_fn (op0))
3066 op0 = default_conversion (op0);
3067 if (!really_overloaded_fn (op1))
3068 op1 = default_conversion (op1);
3071 /* Strip NON_LVALUE_EXPRs, etc., since we aren't using as an lvalue. */
3072 STRIP_TYPE_NOPS (op0);
3073 STRIP_TYPE_NOPS (op1);
3075 /* DTRT if one side is an overloaded function, but complain about it. */
3076 if (type_unknown_p (op0))
3078 tree t = instantiate_type (TREE_TYPE (op1), op0, tf_none);
3079 if (t != error_mark_node)
3081 pedwarn ("assuming cast to type %qT from overloaded function",
3086 if (type_unknown_p (op1))
3088 tree t = instantiate_type (TREE_TYPE (op0), op1, tf_none);
3089 if (t != error_mark_node)
3091 pedwarn ("assuming cast to type %qT from overloaded function",
3097 type0 = TREE_TYPE (op0);
3098 type1 = TREE_TYPE (op1);
3100 /* The expression codes of the data types of the arguments tell us
3101 whether the arguments are integers, floating, pointers, etc. */
3102 code0 = TREE_CODE (type0);
3103 code1 = TREE_CODE (type1);
3105 /* If an error was already reported for one of the arguments,
3106 avoid reporting another error. */
3108 if (code0 == ERROR_MARK || code1 == ERROR_MARK)
3109 return error_mark_node;
3111 if ((invalid_op_diag
3112 = targetm.invalid_binary_op (code, type0, type1)))
3114 error (invalid_op_diag);
3115 return error_mark_node;
3121 /* Subtraction of two similar pointers.
3122 We must subtract them as integers, then divide by object size. */
3123 if (code0 == POINTER_TYPE && code1 == POINTER_TYPE
3124 && same_type_ignoring_top_level_qualifiers_p (TREE_TYPE (type0),
3126 return pointer_diff (op0, op1, common_type (type0, type1));
3127 /* In all other cases except pointer - int, the usual arithmetic
3129 else if (!(code0 == POINTER_TYPE && code1 == INTEGER_TYPE))
3134 /* The pointer - int case is just like pointer + int; fall
3137 if ((code0 == POINTER_TYPE || code1 == POINTER_TYPE)
3138 && (code0 == INTEGER_TYPE || code1 == INTEGER_TYPE))
3142 ptr_operand = ((code0 == POINTER_TYPE) ? op0 : op1);
3143 int_operand = ((code0 == INTEGER_TYPE) ? op0 : op1);
3144 if (processing_template_decl)
3146 result_type = TREE_TYPE (ptr_operand);
3149 return cp_pointer_int_sum (code,
3160 case TRUNC_DIV_EXPR:
3162 case FLOOR_DIV_EXPR:
3163 case ROUND_DIV_EXPR:
3164 case EXACT_DIV_EXPR:
3165 if ((code0 == INTEGER_TYPE || code0 == REAL_TYPE
3166 || code0 == COMPLEX_TYPE || code0 == VECTOR_TYPE)
3167 && (code1 == INTEGER_TYPE || code1 == REAL_TYPE
3168 || code1 == COMPLEX_TYPE || code1 == VECTOR_TYPE))
3170 enum tree_code tcode0 = code0, tcode1 = code1;
3172 warn_for_div_by_zero (op1);
3174 if (tcode0 == COMPLEX_TYPE || tcode0 == VECTOR_TYPE)
3175 tcode0 = TREE_CODE (TREE_TYPE (TREE_TYPE (op0)));
3176 if (tcode1 == COMPLEX_TYPE || tcode1 == VECTOR_TYPE)
3177 tcode1 = TREE_CODE (TREE_TYPE (TREE_TYPE (op1)));
3179 if (!(tcode0 == INTEGER_TYPE && tcode1 == INTEGER_TYPE))
3180 resultcode = RDIV_EXPR;
3182 /* When dividing two signed integers, we have to promote to int.
3183 unless we divide by a constant != -1. Note that default
3184 conversion will have been performed on the operands at this
3185 point, so we have to dig out the original type to find out if
3187 shorten = ((TREE_CODE (op0) == NOP_EXPR
3188 && TYPE_UNSIGNED (TREE_TYPE (TREE_OPERAND (op0, 0))))
3189 || (TREE_CODE (op1) == INTEGER_CST
3190 && ! integer_all_onesp (op1)));
3199 if ((code0 == INTEGER_TYPE && code1 == INTEGER_TYPE)
3200 || (code0 == VECTOR_TYPE && code1 == VECTOR_TYPE))
3204 case TRUNC_MOD_EXPR:
3205 case FLOOR_MOD_EXPR:
3206 warn_for_div_by_zero (op1);
3208 if (code0 == INTEGER_TYPE && code1 == INTEGER_TYPE)
3210 /* Although it would be tempting to shorten always here, that loses
3211 on some targets, since the modulo instruction is undefined if the
3212 quotient can't be represented in the computation mode. We shorten
3213 only if unsigned or if dividing by something we know != -1. */
3214 shorten = ((TREE_CODE (op0) == NOP_EXPR
3215 && TYPE_UNSIGNED (TREE_TYPE (TREE_OPERAND (op0, 0))))
3216 || (TREE_CODE (op1) == INTEGER_CST
3217 && ! integer_all_onesp (op1)));
3222 case TRUTH_ANDIF_EXPR:
3223 case TRUTH_ORIF_EXPR:
3224 case TRUTH_AND_EXPR:
3226 result_type = boolean_type_node;
3229 /* Shift operations: result has same type as first operand;
3230 always convert second operand to int.
3231 Also set SHORT_SHIFT if shifting rightward. */
3234 if (code0 == INTEGER_TYPE && code1 == INTEGER_TYPE)
3236 result_type = type0;
3237 if (TREE_CODE (op1) == INTEGER_CST)
3239 if (tree_int_cst_lt (op1, integer_zero_node))
3240 warning (0, "right shift count is negative");
3243 if (! integer_zerop (op1))
3245 if (compare_tree_int (op1, TYPE_PRECISION (type0)) >= 0)
3246 warning (0, "right shift count >= width of type");
3249 /* Convert the shift-count to an integer, regardless of
3250 size of value being shifted. */
3251 if (TYPE_MAIN_VARIANT (TREE_TYPE (op1)) != integer_type_node)
3252 op1 = cp_convert (integer_type_node, op1);
3253 /* Avoid converting op1 to result_type later. */
3259 if (code0 == INTEGER_TYPE && code1 == INTEGER_TYPE)
3261 result_type = type0;
3262 if (TREE_CODE (op1) == INTEGER_CST)
3264 if (tree_int_cst_lt (op1, integer_zero_node))
3265 warning (0, "left shift count is negative");
3266 else if (compare_tree_int (op1, TYPE_PRECISION (type0)) >= 0)
3267 warning (0, "left shift count >= width of type");
3269 /* Convert the shift-count to an integer, regardless of
3270 size of value being shifted. */
3271 if (TYPE_MAIN_VARIANT (TREE_TYPE (op1)) != integer_type_node)
3272 op1 = cp_convert (integer_type_node, op1);
3273 /* Avoid converting op1 to result_type later. */
3280 if (code0 == INTEGER_TYPE && code1 == INTEGER_TYPE)
3282 result_type = type0;
3283 if (TREE_CODE (op1) == INTEGER_CST)
3285 if (tree_int_cst_lt (op1, integer_zero_node))
3286 warning (0, (code == LROTATE_EXPR)
3287 ? G_("left rotate count is negative")
3288 : G_("right rotate count is negative"));
3289 else if (compare_tree_int (op1, TYPE_PRECISION (type0)) >= 0)
3290 warning (0, (code == LROTATE_EXPR)
3291 ? G_("left rotate count >= width of type")
3292 : G_("right rotate count >= width of type"));
3294 /* Convert the shift-count to an integer, regardless of
3295 size of value being shifted. */
3296 if (TYPE_MAIN_VARIANT (TREE_TYPE (op1)) != integer_type_node)
3297 op1 = cp_convert (integer_type_node, op1);
3303 if (code0 == REAL_TYPE || code1 == REAL_TYPE)
3304 warning (OPT_Wfloat_equal,
3305 "comparing floating point with == or != is unsafe");
3306 if ((TREE_CODE (orig_op0) == STRING_CST && !integer_zerop (op1))
3307 || (TREE_CODE (orig_op1) == STRING_CST && !integer_zerop (op0)))
3308 warning (OPT_Waddress, "comparison with string literal results in unspecified behaviour");
3310 build_type = boolean_type_node;
3311 if ((code0 == INTEGER_TYPE || code0 == REAL_TYPE
3312 || code0 == COMPLEX_TYPE)
3313 && (code1 == INTEGER_TYPE || code1 == REAL_TYPE
3314 || code1 == COMPLEX_TYPE))
3316 else if ((code0 == POINTER_TYPE && code1 == POINTER_TYPE)
3317 || (TYPE_PTRMEM_P (type0) && TYPE_PTRMEM_P (type1)))
3318 result_type = composite_pointer_type (type0, type1, op0, op1,
3320 else if ((code0 == POINTER_TYPE || TYPE_PTRMEM_P (type0))
3321 && null_ptr_cst_p (op1))
3323 if (TREE_CODE (op0) == ADDR_EXPR
3324 && decl_with_nonnull_addr_p (TREE_OPERAND (op0, 0)))
3325 warning (OPT_Waddress, "the address of %qD will never be NULL",
3326 TREE_OPERAND (op0, 0));
3327 result_type = type0;
3329 else if ((code1 == POINTER_TYPE || TYPE_PTRMEM_P (type1))
3330 && null_ptr_cst_p (op0))
3332 if (TREE_CODE (op1) == ADDR_EXPR
3333 && decl_with_nonnull_addr_p (TREE_OPERAND (op1, 0)))
3334 warning (OPT_Waddress, "the address of %qD will never be NULL",
3335 TREE_OPERAND (op1, 0));
3336 result_type = type1;
3338 else if (code0 == POINTER_TYPE && code1 == INTEGER_TYPE)
3340 result_type = type0;
3341 error ("ISO C++ forbids comparison between pointer and integer");
3343 else if (code0 == INTEGER_TYPE && code1 == POINTER_TYPE)
3345 result_type = type1;
3346 error ("ISO C++ forbids comparison between pointer and integer");
3348 else if (TYPE_PTRMEMFUNC_P (type0) && null_ptr_cst_p (op1))
3350 if (TARGET_PTRMEMFUNC_VBIT_LOCATION
3351 == ptrmemfunc_vbit_in_delta)
3353 tree pfn0 = pfn_from_ptrmemfunc (op0);
3354 tree delta0 = build_ptrmemfunc_access_expr (op0,
3356 tree e1 = cp_build_binary_op (EQ_EXPR,
3358 fold_convert (TREE_TYPE (pfn0),
3359 integer_zero_node));
3360 tree e2 = cp_build_binary_op (BIT_AND_EXPR,
3363 e2 = cp_build_binary_op (EQ_EXPR, e2, integer_zero_node);
3364 op0 = cp_build_binary_op (TRUTH_ANDIF_EXPR, e1, e2);
3365 op1 = cp_convert (TREE_TYPE (op0), integer_one_node);
3369 op0 = build_ptrmemfunc_access_expr (op0, pfn_identifier);
3370 op1 = cp_convert (TREE_TYPE (op0), integer_zero_node);
3372 result_type = TREE_TYPE (op0);
3374 else if (TYPE_PTRMEMFUNC_P (type1) && null_ptr_cst_p (op0))
3375 return cp_build_binary_op (code, op1, op0);
3376 else if (TYPE_PTRMEMFUNC_P (type0) && TYPE_PTRMEMFUNC_P (type1)
3377 && same_type_p (type0, type1))
3379 /* E will be the final comparison. */
3381 /* E1 and E2 are for scratch. */
3389 if (TREE_SIDE_EFFECTS (op0))
3390 op0 = save_expr (op0);
3391 if (TREE_SIDE_EFFECTS (op1))
3392 op1 = save_expr (op1);
3394 pfn0 = pfn_from_ptrmemfunc (op0);
3395 pfn1 = pfn_from_ptrmemfunc (op1);
3396 delta0 = build_ptrmemfunc_access_expr (op0,
3398 delta1 = build_ptrmemfunc_access_expr (op1,
3400 if (TARGET_PTRMEMFUNC_VBIT_LOCATION
3401 == ptrmemfunc_vbit_in_delta)
3406 && ((op0.delta == op1.delta)
3407 || (!op0.pfn && op0.delta & 1 == 0
3408 && op1.delta & 1 == 0))
3410 The reason for the `!op0.pfn' bit is that a NULL
3411 pointer-to-member is any member with a zero PFN and
3412 LSB of the DELTA field is 0. */
3414 e1 = cp_build_binary_op (BIT_AND_EXPR,
3417 e1 = cp_build_binary_op (EQ_EXPR, e1, integer_zero_node);
3418 e2 = cp_build_binary_op (BIT_AND_EXPR,
3421 e2 = cp_build_binary_op (EQ_EXPR, e2, integer_zero_node);
3422 e1 = cp_build_binary_op (TRUTH_ANDIF_EXPR, e2, e1);
3423 e2 = cp_build_binary_op (EQ_EXPR,
3425 fold_convert (TREE_TYPE (pfn0),
3426 integer_zero_node));
3427 e2 = cp_build_binary_op (TRUTH_ANDIF_EXPR, e2, e1);
3428 e1 = cp_build_binary_op (EQ_EXPR, delta0, delta1);
3429 e1 = cp_build_binary_op (TRUTH_ORIF_EXPR, e1, e2);
3436 && (!op0.pfn || op0.delta == op1.delta))
3438 The reason for the `!op0.pfn' bit is that a NULL
3439 pointer-to-member is any member with a zero PFN; the
3440 DELTA field is unspecified. */
3442 e1 = cp_build_binary_op (EQ_EXPR, delta0, delta1);
3443 e2 = cp_build_binary_op (EQ_EXPR,
3445 fold_convert (TREE_TYPE (pfn0),
3446 integer_zero_node));
3447 e1 = cp_build_binary_op (TRUTH_ORIF_EXPR, e1, e2);
3449 e2 = build2 (EQ_EXPR, boolean_type_node, pfn0, pfn1);
3450 e = cp_build_binary_op (TRUTH_ANDIF_EXPR, e2, e1);
3451 if (code == EQ_EXPR)
3453 return cp_build_binary_op (EQ_EXPR, e, integer_zero_node);
3457 gcc_assert (!TYPE_PTRMEMFUNC_P (type0)
3458 || !same_type_p (TYPE_PTRMEMFUNC_FN_TYPE (type0),
3460 gcc_assert (!TYPE_PTRMEMFUNC_P (type1)
3461 || !same_type_p (TYPE_PTRMEMFUNC_FN_TYPE (type1),
3469 if ((code0 == INTEGER_TYPE || code0 == REAL_TYPE)
3470 && (code1 == INTEGER_TYPE || code1 == REAL_TYPE))
3472 else if (code0 == POINTER_TYPE && code1 == POINTER_TYPE)
3473 result_type = composite_pointer_type (type0, type1, op0, op1,
3481 if (TREE_CODE (orig_op0) == STRING_CST
3482 || TREE_CODE (orig_op1) == STRING_CST)
3483 warning (OPT_Waddress, "comparison with string literal results in unspecified behaviour");
3485 build_type = boolean_type_node;
3486 if ((code0 == INTEGER_TYPE || code0 == REAL_TYPE)
3487 && (code1 == INTEGER_TYPE || code1 == REAL_TYPE))
3489 else if (code0 == POINTER_TYPE && code1 == POINTER_TYPE)
3490 result_type = composite_pointer_type (type0, type1, op0, op1,
3492 else if (code0 == POINTER_TYPE && TREE_CODE (op1) == INTEGER_CST
3493 && integer_zerop (op1))
3494 result_type = type0;
3495 else if (code1 == POINTER_TYPE && TREE_CODE (op0) == INTEGER_CST
3496 && integer_zerop (op0))
3497 result_type = type1;
3498 else if (code0 == POINTER_TYPE && code1 == INTEGER_TYPE)
3500 result_type = type0;
3501 pedwarn ("ISO C++ forbids comparison between pointer and integer");
3503 else if (code0 == INTEGER_TYPE && code1 == POINTER_TYPE)
3505 result_type = type1;
3506 pedwarn ("ISO C++ forbids comparison between pointer and integer");
3510 case UNORDERED_EXPR:
3517 build_type = integer_type_node;
3518 if (code0 != REAL_TYPE || code1 != REAL_TYPE)
3520 error ("unordered comparison on non-floating point argument");
3521 return error_mark_node;
3530 if (((code0 == INTEGER_TYPE || code0 == REAL_TYPE || code0 == COMPLEX_TYPE)
3531 && (code1 == INTEGER_TYPE || code1 == REAL_TYPE
3532 || code1 == COMPLEX_TYPE)))
3533 arithmetic_types_p = 1;
3536 arithmetic_types_p = 0;
3537 /* Vector arithmetic is only allowed when both sides are vectors. */
3538 if (code0 == VECTOR_TYPE && code1 == VECTOR_TYPE)
3540 if (!tree_int_cst_equal (TYPE_SIZE (type0), TYPE_SIZE (type1))
3541 || !same_scalar_type_ignoring_signedness (TREE_TYPE (type0),
3544 binary_op_error (code);
3545 return error_mark_node;
3547 arithmetic_types_p = 1;
3550 /* Determine the RESULT_TYPE, if it is not already known. */
3552 && arithmetic_types_p
3553 && (shorten || common || short_compare))
3554 result_type = common_type (type0, type1);
3558 error ("invalid operands of types %qT and %qT to binary %qO",
3559 TREE_TYPE (orig_op0), TREE_TYPE (orig_op1), code);
3560 return error_mark_node;
3563 /* If we're in a template, the only thing we need to know is the
3565 if (processing_template_decl)
3566 return build2 (resultcode,
3567 build_type ? build_type : result_type,
3570 if (arithmetic_types_p)
3572 int none_complex = (code0 != COMPLEX_TYPE && code1 != COMPLEX_TYPE);
3574 /* For certain operations (which identify themselves by shorten != 0)
3575 if both args were extended from the same smaller type,
3576 do the arithmetic in that type and then extend.
3578 shorten !=0 and !=1 indicates a bitwise operation.
3579 For them, this optimization is safe only if
3580 both args are zero-extended or both are sign-extended.
3581 Otherwise, we might change the result.
3582 Eg, (short)-1 | (unsigned short)-1 is (int)-1
3583 but calculated in (unsigned short) it would be (unsigned short)-1. */
3585 if (shorten && none_complex)
3587 int unsigned0, unsigned1;
3588 tree arg0 = get_narrower (op0, &unsigned0);
3589 tree arg1 = get_narrower (op1, &unsigned1);
3590 /* UNS is 1 if the operation to be done is an unsigned one. */
3591 int uns = TYPE_UNSIGNED (result_type);
3594 final_type = result_type;
3596 /* Handle the case that OP0 does not *contain* a conversion
3597 but it *requires* conversion to FINAL_TYPE. */
3599 if (op0 == arg0 && TREE_TYPE (op0) != final_type)
3600 unsigned0 = TYPE_UNSIGNED (TREE_TYPE (op0));
3601 if (op1 == arg1 && TREE_TYPE (op1) != final_type)
3602 unsigned1 = TYPE_UNSIGNED (TREE_TYPE (op1));
3604 /* Now UNSIGNED0 is 1 if ARG0 zero-extends to FINAL_TYPE. */
3606 /* For bitwise operations, signedness of nominal type
3607 does not matter. Consider only how operands were extended. */
3611 /* Note that in all three cases below we refrain from optimizing
3612 an unsigned operation on sign-extended args.
3613 That would not be valid. */
3615 /* Both args variable: if both extended in same way
3616 from same width, do it in that width.
3617 Do it unsigned if args were zero-extended. */
3618 if ((TYPE_PRECISION (TREE_TYPE (arg0))
3619 < TYPE_PRECISION (result_type))
3620 && (TYPE_PRECISION (TREE_TYPE (arg1))
3621 == TYPE_PRECISION (TREE_TYPE (arg0)))
3622 && unsigned0 == unsigned1
3623 && (unsigned0 || !uns))
3624 result_type = c_common_signed_or_unsigned_type
3625 (unsigned0, common_type (TREE_TYPE (arg0), TREE_TYPE (arg1)));
3626 else if (TREE_CODE (arg0) == INTEGER_CST
3627 && (unsigned1 || !uns)
3628 && (TYPE_PRECISION (TREE_TYPE (arg1))
3629 < TYPE_PRECISION (result_type))
3630 && (type = c_common_signed_or_unsigned_type
3631 (unsigned1, TREE_TYPE (arg1)),
3632 int_fits_type_p (arg0, type)))
3634 else if (TREE_CODE (arg1) == INTEGER_CST
3635 && (unsigned0 || !uns)
3636 && (TYPE_PRECISION (TREE_TYPE (arg0))
3637 < TYPE_PRECISION (result_type))
3638 && (type = c_common_signed_or_unsigned_type
3639 (unsigned0, TREE_TYPE (arg0)),
3640 int_fits_type_p (arg1, type)))
3644 /* Shifts can be shortened if shifting right. */
3649 tree arg0 = get_narrower (op0, &unsigned_arg);
3651 final_type = result_type;
3653 if (arg0 == op0 && final_type == TREE_TYPE (op0))
3654 unsigned_arg = TYPE_UNSIGNED (TREE_TYPE (op0));
3656 if (TYPE_PRECISION (TREE_TYPE (arg0)) < TYPE_PRECISION (result_type)
3657 /* We can shorten only if the shift count is less than the
3658 number of bits in the smaller type size. */
3659 && compare_tree_int (op1, TYPE_PRECISION (TREE_TYPE (arg0))) < 0
3660 /* If arg is sign-extended and then unsigned-shifted,
3661 we can simulate this with a signed shift in arg's type
3662 only if the extended result is at least twice as wide
3663 as the arg. Otherwise, the shift could use up all the
3664 ones made by sign-extension and bring in zeros.
3665 We can't optimize that case at all, but in most machines
3666 it never happens because available widths are 2**N. */
3667 && (!TYPE_UNSIGNED (final_type)
3669 || (((unsigned) 2 * TYPE_PRECISION (TREE_TYPE (arg0)))
3670 <= TYPE_PRECISION (result_type))))
3672 /* Do an unsigned shift if the operand was zero-extended. */
3674 = c_common_signed_or_unsigned_type (unsigned_arg,
3676 /* Convert value-to-be-shifted to that type. */
3677 if (TREE_TYPE (op0) != result_type)
3678 op0 = cp_convert (result_type, op0);
3683 /* Comparison operations are shortened too but differently.
3684 They identify themselves by setting short_compare = 1. */
3688 /* Don't write &op0, etc., because that would prevent op0
3689 from being kept in a register.
3690 Instead, make copies of the our local variables and
3691 pass the copies by reference, then copy them back afterward. */
3692 tree xop0 = op0, xop1 = op1, xresult_type = result_type;
3693 enum tree_code xresultcode = resultcode;
3695 = shorten_compare (&xop0, &xop1, &xresult_type, &xresultcode);
3697 return cp_convert (boolean_type_node, val);
3698 op0 = xop0, op1 = xop1;
3700 resultcode = xresultcode;
3703 if ((short_compare || code == MIN_EXPR || code == MAX_EXPR)
3704 && warn_sign_compare
3705 /* Do not warn until the template is instantiated; we cannot
3706 bound the ranges of the arguments until that point. */
3707 && !processing_template_decl)
3709 int op0_signed = !TYPE_UNSIGNED (TREE_TYPE (orig_op0));
3710 int op1_signed = !TYPE_UNSIGNED (TREE_TYPE (orig_op1));
3712 int unsignedp0, unsignedp1;
3713 tree primop0 = get_narrower (op0, &unsignedp0);
3714 tree primop1 = get_narrower (op1, &unsignedp1);
3716 /* Check for comparison of different enum types. */
3717 if (TREE_CODE (TREE_TYPE (orig_op0)) == ENUMERAL_TYPE
3718 && TREE_CODE (TREE_TYPE (orig_op1)) == ENUMERAL_TYPE
3719 && TYPE_MAIN_VARIANT (TREE_TYPE (orig_op0))
3720 != TYPE_MAIN_VARIANT (TREE_TYPE (orig_op1)))
3722 warning (0, "comparison between types %q#T and %q#T",
3723 TREE_TYPE (orig_op0), TREE_TYPE (orig_op1));
3726 /* Give warnings for comparisons between signed and unsigned
3727 quantities that may fail. */
3728 /* Do the checking based on the original operand trees, so that
3729 casts will be considered, but default promotions won't be. */
3731 /* Do not warn if the comparison is being done in a signed type,
3732 since the signed type will only be chosen if it can represent
3733 all the values of the unsigned type. */
3734 if (!TYPE_UNSIGNED (result_type))
3736 /* Do not warn if both operands are unsigned. */
3737 else if (op0_signed == op1_signed)
3739 /* Do not warn if the signed quantity is an unsuffixed
3740 integer literal (or some static constant expression
3741 involving such literals or a conditional expression
3742 involving such literals) and it is non-negative. */
3743 else if ((op0_signed && tree_expr_nonnegative_p (orig_op0))
3744 || (op1_signed && tree_expr_nonnegative_p (orig_op1)))
3746 /* Do not warn if the comparison is an equality operation,
3747 the unsigned quantity is an integral constant and it does
3748 not use the most significant bit of result_type. */
3749 else if ((resultcode == EQ_EXPR || resultcode == NE_EXPR)
3750 && ((op0_signed && TREE_CODE (orig_op1) == INTEGER_CST
3751 && int_fits_type_p (orig_op1, c_common_signed_type
3753 || (op1_signed && TREE_CODE (orig_op0) == INTEGER_CST
3754 && int_fits_type_p (orig_op0, c_common_signed_type
3758 warning (0, "comparison between signed and unsigned integer expressions");
3760 /* Warn if two unsigned values are being compared in a size
3761 larger than their original size, and one (and only one) is the
3762 result of a `~' operator. This comparison will always fail.
3764 Also warn if one operand is a constant, and the constant does not
3765 have all bits set that are set in the ~ operand when it is
3768 if ((TREE_CODE (primop0) == BIT_NOT_EXPR)
3769 ^ (TREE_CODE (primop1) == BIT_NOT_EXPR))
3771 if (TREE_CODE (primop0) == BIT_NOT_EXPR)
3772 primop0 = get_narrower (TREE_OPERAND (op0, 0), &unsignedp0);
3773 if (TREE_CODE (primop1) == BIT_NOT_EXPR)
3774 primop1 = get_narrower (TREE_OPERAND (op1, 0), &unsignedp1);
3776 if (host_integerp (primop0, 0) || host_integerp (primop1, 0))
3779 HOST_WIDE_INT constant, mask;
3783 if (host_integerp (primop0, 0))
3786 unsignedp = unsignedp1;
3787 constant = tree_low_cst (primop0, 0);
3792 unsignedp = unsignedp0;
3793 constant = tree_low_cst (primop1, 0);
3796 bits = TYPE_PRECISION (TREE_TYPE (primop));
3797 if (bits < TYPE_PRECISION (result_type)
3798 && bits < HOST_BITS_PER_LONG && unsignedp)
3800 mask = (~ (HOST_WIDE_INT) 0) << bits;
3801 if ((mask & constant) != mask)
3802 warning (0, "comparison of promoted ~unsigned with constant");
3805 else if (unsignedp0 && unsignedp1
3806 && (TYPE_PRECISION (TREE_TYPE (primop0))
3807 < TYPE_PRECISION (result_type))
3808 && (TYPE_PRECISION (TREE_TYPE (primop1))
3809 < TYPE_PRECISION (result_type)))
3810 warning (0, "comparison of promoted ~unsigned with unsigned");
3815 /* Issue warnings about peculiar, but valid, uses of NULL. */
3816 if ((orig_op0 == null_node || orig_op1 == null_node)
3817 /* It's reasonable to use pointer values as operands of &&
3818 and ||, so NULL is no exception. */
3819 && code != TRUTH_ANDIF_EXPR && code != TRUTH_ORIF_EXPR
3820 && ( /* Both are NULL (or 0) and the operation was not a comparison. */
3821 (null_ptr_cst_p (orig_op0) && null_ptr_cst_p (orig_op1)
3822 && code != EQ_EXPR && code != NE_EXPR)
3823 /* Or if one of OP0 or OP1 is neither a pointer nor NULL. */
3824 || (!null_ptr_cst_p (orig_op0) && TREE_CODE (TREE_TYPE (op0)) != POINTER_TYPE)
3825 || (!null_ptr_cst_p (orig_op1) && TREE_CODE (TREE_TYPE (op1)) != POINTER_TYPE)))
3826 /* Some sort of arithmetic operation involving NULL was
3827 performed. Note that pointer-difference and pointer-addition
3828 have already been handled above, and so we don't end up here in
3830 warning (OPT_Wpointer_arith, "NULL used in arithmetic");
3833 /* If CONVERTED is zero, both args will be converted to type RESULT_TYPE.
3834 Then the expression will be built.
3835 It will be given type FINAL_TYPE if that is nonzero;
3836 otherwise, it will be given type RESULT_TYPE. */
3839 if (TREE_TYPE (op0) != result_type)
3840 op0 = cp_convert_and_check (result_type, op0);
3841 if (TREE_TYPE (op1) != result_type)
3842 op1 = cp_convert_and_check (result_type, op1);
3844 if (op0 == error_mark_node || op1 == error_mark_node)
3845 return error_mark_node;
3848 if (build_type == NULL_TREE)
3849 build_type = result_type;
3851 result = build2 (resultcode, build_type, op0, op1);
3852 result = fold_if_not_in_template (result);
3853 if (final_type != 0)
3854 result = cp_convert (final_type, result);
3856 if (TREE_OVERFLOW_P (result)
3857 && !TREE_OVERFLOW_P (op0)
3858 && !TREE_OVERFLOW_P (op1))
3859 overflow_warning (result);
3864 /* Return a tree for the sum or difference (RESULTCODE says which)
3865 of pointer PTROP and integer INTOP. */
3868 cp_pointer_int_sum (enum tree_code resultcode, tree ptrop, tree intop)
3870 tree res_type = TREE_TYPE (ptrop);
3872 /* pointer_int_sum() uses size_in_bytes() on the TREE_TYPE(res_type)
3873 in certain circumstance (when it's valid to do so). So we need
3874 to make sure it's complete. We don't need to check here, if we
3875 can actually complete it at all, as those checks will be done in
3876 pointer_int_sum() anyway. */
3877 complete_type (TREE_TYPE (res_type));
3879 return pointer_int_sum (resultcode, ptrop,
3880 fold_if_not_in_template (intop));
3883 /* Return a tree for the difference of pointers OP0 and OP1.
3884 The resulting tree has type int. */
3887 pointer_diff (tree op0, tree op1, tree ptrtype)
3890 tree restype = ptrdiff_type_node;
3891 tree target_type = TREE_TYPE (ptrtype);
3893 if (!complete_type_or_else (target_type, NULL_TREE))
3894 return error_mark_node;
3896 if (pedantic || warn_pointer_arith)
3898 if (TREE_CODE (target_type) == VOID_TYPE)
3899 pedwarn ("ISO C++ forbids using pointer of type %<void *%> in subtraction");
3900 if (TREE_CODE (target_type) == FUNCTION_TYPE)
3901 pedwarn ("ISO C++ forbids using pointer to a function in subtraction");
3902 if (TREE_CODE (target_type) == METHOD_TYPE)
3903 pedwarn ("ISO C++ forbids using pointer to a method in subtraction");
3906 /* First do the subtraction as integers;
3907 then drop through to build the divide operator. */
3909 op0 = cp_build_binary_op (MINUS_EXPR,
3910 cp_convert (restype, op0),
3911 cp_convert (restype, op1));
3913 /* This generates an error if op1 is a pointer to an incomplete type. */
3914 if (!COMPLETE_TYPE_P (TREE_TYPE (TREE_TYPE (op1))))
3915 error ("invalid use of a pointer to an incomplete type in pointer arithmetic");
3917 op1 = (TYPE_PTROB_P (ptrtype)
3918 ? size_in_bytes (target_type)
3919 : integer_one_node);
3921 /* Do the division. */
3923 result = build2 (EXACT_DIV_EXPR, restype, op0, cp_convert (restype, op1));
3924 return fold_if_not_in_template (result);
3927 /* Construct and perhaps optimize a tree representation
3928 for a unary operation. CODE, a tree_code, specifies the operation
3929 and XARG is the operand. */
3932 build_x_unary_op (enum tree_code code, tree xarg)
3934 tree orig_expr = xarg;
3938 if (processing_template_decl)
3940 if (type_dependent_expression_p (xarg))
3941 return build_min_nt (code, xarg, NULL_TREE);
3943 xarg = build_non_dependent_expr (xarg);
3948 /* [expr.unary.op] says:
3950 The address of an object of incomplete type can be taken.
3952 (And is just the ordinary address operator, not an overloaded
3953 "operator &".) However, if the type is a template
3954 specialization, we must complete the type at this point so that
3955 an overloaded "operator &" will be available if required. */
3956 if (code == ADDR_EXPR
3957 && TREE_CODE (xarg) != TEMPLATE_ID_EXPR
3958 && ((CLASS_TYPE_P (TREE_TYPE (xarg))
3959 && !COMPLETE_TYPE_P (complete_type (TREE_TYPE (xarg))))
3960 || (TREE_CODE (xarg) == OFFSET_REF)))
3961 /* Don't look for a function. */;
3963 exp = build_new_op (code, LOOKUP_NORMAL, xarg, NULL_TREE, NULL_TREE,
3964 /*overloaded_p=*/NULL);
3965 if (!exp && code == ADDR_EXPR)
3967 /* A pointer to member-function can be formed only by saying
3969 if (!flag_ms_extensions && TREE_CODE (TREE_TYPE (xarg)) == METHOD_TYPE
3970 && (TREE_CODE (xarg) != OFFSET_REF || !PTRMEM_OK_P (xarg)))
3972 if (TREE_CODE (xarg) != OFFSET_REF
3973 || !TYPE_P (TREE_OPERAND (xarg, 0)))
3975 error ("invalid use of %qE to form a pointer-to-member-function",
3977 if (TREE_CODE (xarg) != OFFSET_REF)
3978 inform (" a qualified-id is required");
3979 return error_mark_node;
3983 error ("parentheses around %qE cannot be used to form a"
3984 " pointer-to-member-function",
3986 PTRMEM_OK_P (xarg) = 1;
3990 if (TREE_CODE (xarg) == OFFSET_REF)
3992 ptrmem = PTRMEM_OK_P (xarg);
3994 if (!ptrmem && !flag_ms_extensions
3995 && TREE_CODE (TREE_TYPE (TREE_OPERAND (xarg, 1))) == METHOD_TYPE)
3997 /* A single non-static member, make sure we don't allow a
3998 pointer-to-member. */
3999 xarg = build2 (OFFSET_REF, TREE_TYPE (xarg),
4000 TREE_OPERAND (xarg, 0),
4001 ovl_cons (TREE_OPERAND (xarg, 1), NULL_TREE));
4002 PTRMEM_OK_P (xarg) = ptrmem;
4005 else if (TREE_CODE (xarg) == TARGET_EXPR)
4006 warning (0, "taking address of temporary");
4007 exp = build_unary_op (ADDR_EXPR, xarg, 0);
4010 if (processing_template_decl && exp != error_mark_node)
4011 exp = build_min_non_dep (code, exp, orig_expr,
4012 /*For {PRE,POST}{INC,DEC}REMENT_EXPR*/NULL_TREE);
4013 if (TREE_CODE (exp) == ADDR_EXPR)
4014 PTRMEM_OK_P (exp) = ptrmem;
4018 /* Like c_common_truthvalue_conversion, but handle pointer-to-member
4019 constants, where a null value is represented by an INTEGER_CST of
4023 cp_truthvalue_conversion (tree expr)
4025 tree type = TREE_TYPE (expr);
4026 if (TYPE_PTRMEM_P (type))
4027 return build_binary_op (NE_EXPR, expr, integer_zero_node, 1);
4029 return c_common_truthvalue_conversion (expr);
4032 /* Just like cp_truthvalue_conversion, but we want a CLEANUP_POINT_EXPR. */
4035 condition_conversion (tree expr)
4038 if (processing_template_decl)
4040 t = perform_implicit_conversion (boolean_type_node, expr);
4041 t = fold_build_cleanup_point_expr (boolean_type_node, t);
4045 /* Return an ADDR_EXPR giving the address of T. This function
4046 attempts no optimizations or simplifications; it is a low-level
4050 build_address (tree t)
4054 if (error_operand_p (t) || !cxx_mark_addressable (t))
4055 return error_mark_node;
4057 addr = build1 (ADDR_EXPR, build_pointer_type (TREE_TYPE (t)), t);
4062 /* Return a NOP_EXPR converting EXPR to TYPE. */
4065 build_nop (tree type, tree expr)
4067 if (type == error_mark_node || error_operand_p (expr))
4069 return build1 (NOP_EXPR, type, expr);
4072 /* C++: Must handle pointers to members.
4074 Perhaps type instantiation should be extended to handle conversion
4075 from aggregates to types we don't yet know we want? (Or are those
4076 cases typically errors which should be reported?)
4078 NOCONVERT nonzero suppresses the default promotions
4079 (such as from short to int). */
4082 build_unary_op (enum tree_code code, tree xarg, int noconvert)
4084 /* No default_conversion here. It causes trouble for ADDR_EXPR. */
4087 const char *errstring = NULL;
4089 const char *invalid_op_diag;
4091 if (arg == error_mark_node)
4092 return error_mark_node;
4094 if ((invalid_op_diag
4095 = targetm.invalid_unary_op ((code == UNARY_PLUS_EXPR
4100 error (invalid_op_diag);
4101 return error_mark_node;
4106 case UNARY_PLUS_EXPR:
4109 int flags = WANT_ARITH | WANT_ENUM;
4110 /* Unary plus (but not unary minus) is allowed on pointers. */
4111 if (code == UNARY_PLUS_EXPR)
4112 flags |= WANT_POINTER;
4113 arg = build_expr_type_conversion (flags, arg, true);
4115 errstring = (code == NEGATE_EXPR
4116 ? "wrong type argument to unary minus"
4117 : "wrong type argument to unary plus");
4120 if (!noconvert && CP_INTEGRAL_TYPE_P (TREE_TYPE (arg)))
4121 arg = perform_integral_promotions (arg);
4123 /* Make sure the result is not an lvalue: a unary plus or minus
4124 expression is always a rvalue. */
4131 if (TREE_CODE (TREE_TYPE (arg)) == COMPLEX_TYPE)
4135 arg = default_conversion (arg);
4137 else if (!(arg = build_expr_type_conversion (WANT_INT | WANT_ENUM
4140 errstring = "wrong type argument to bit-complement";
4141 else if (!noconvert && CP_INTEGRAL_TYPE_P (TREE_TYPE (arg)))
4142 arg = perform_integral_promotions (arg);
4146 if (!(arg = build_expr_type_conversion (WANT_ARITH | WANT_ENUM, arg, true)))
4147 errstring = "wrong type argument to abs";
4148 else if (!noconvert)
4149 arg = default_conversion (arg);
4153 /* Conjugating a real value is a no-op, but allow it anyway. */
4154 if (!(arg = build_expr_type_conversion (WANT_ARITH | WANT_ENUM, arg, true)))
4155 errstring = "wrong type argument to conjugation";
4156 else if (!noconvert)
4157 arg = default_conversion (arg);
4160 case TRUTH_NOT_EXPR:
4161 arg = perform_implicit_conversion (boolean_type_node, arg);
4162 val = invert_truthvalue (arg);
4163 if (arg != error_mark_node)
4165 errstring = "in argument to unary !";
4172 if (TREE_CODE (arg) == COMPLEX_CST)
4173 return TREE_REALPART (arg);
4174 else if (TREE_CODE (TREE_TYPE (arg)) == COMPLEX_TYPE)
4176 arg = build1 (REALPART_EXPR, TREE_TYPE (TREE_TYPE (arg)), arg);
4177 return fold_if_not_in_template (arg);
4183 if (TREE_CODE (arg) == COMPLEX_CST)
4184 return TREE_IMAGPART (arg);
4185 else if (TREE_CODE (TREE_TYPE (arg)) == COMPLEX_TYPE)
4187 arg = build1 (IMAGPART_EXPR, TREE_TYPE (TREE_TYPE (arg)), arg);
4188 return fold_if_not_in_template (arg);
4191 return cp_convert (TREE_TYPE (arg), integer_zero_node);
4193 case PREINCREMENT_EXPR:
4194 case POSTINCREMENT_EXPR:
4195 case PREDECREMENT_EXPR:
4196 case POSTDECREMENT_EXPR:
4197 /* Handle complex lvalues (when permitted)
4198 by reduction to simpler cases. */
4200 val = unary_complex_lvalue (code, arg);
4204 /* Increment or decrement the real part of the value,
4205 and don't change the imaginary part. */
4206 if (TREE_CODE (TREE_TYPE (arg)) == COMPLEX_TYPE)
4210 arg = stabilize_reference (arg);
4211 real = build_unary_op (REALPART_EXPR, arg, 1);
4212 imag = build_unary_op (IMAGPART_EXPR, arg, 1);
4213 return build2 (COMPLEX_EXPR, TREE_TYPE (arg),
4214 build_unary_op (code, real, 1), imag);
4217 /* Report invalid types. */
4219 if (!(arg = build_expr_type_conversion (WANT_ARITH | WANT_POINTER,
4222 if (code == PREINCREMENT_EXPR)
4223 errstring ="no pre-increment operator for type";
4224 else if (code == POSTINCREMENT_EXPR)
4225 errstring ="no post-increment operator for type";
4226 else if (code == PREDECREMENT_EXPR)
4227 errstring ="no pre-decrement operator for type";
4229 errstring ="no post-decrement operator for type";
4233 /* Report something read-only. */
4235 if (CP_TYPE_CONST_P (TREE_TYPE (arg))
4236 || TREE_READONLY (arg))
4237 readonly_error (arg, ((code == PREINCREMENT_EXPR
4238 || code == POSTINCREMENT_EXPR)
4239 ? "increment" : "decrement"));
4244 tree result_type = TREE_TYPE (arg);
4246 declared_type = unlowered_expr_type (arg);
4248 arg = get_unwidened (arg, 0);
4249 argtype = TREE_TYPE (arg);
4251 /* ARM $5.2.5 last annotation says this should be forbidden. */
4252 if (TREE_CODE (argtype) == ENUMERAL_TYPE)
4253 pedwarn ((code == PREINCREMENT_EXPR || code == POSTINCREMENT_EXPR)
4254 ? G_("ISO C++ forbids incrementing an enum")
4255 : G_("ISO C++ forbids decrementing an enum"));
4257 /* Compute the increment. */
4259 if (TREE_CODE (argtype) == POINTER_TYPE)
4261 tree type = complete_type (TREE_TYPE (argtype));
4263 if (!COMPLETE_OR_VOID_TYPE_P (type))
4264 error (((code == PREINCREMENT_EXPR
4265 || code == POSTINCREMENT_EXPR))
4266 ? G_("cannot increment a pointer to incomplete type %qT")
4267 : G_("cannot decrement a pointer to incomplete type %qT"),
4268 TREE_TYPE (argtype));
4269 else if ((pedantic || warn_pointer_arith)
4270 && !TYPE_PTROB_P (argtype))
4271 pedwarn ((code == PREINCREMENT_EXPR
4272 || code == POSTINCREMENT_EXPR)
4273 ? G_("ISO C++ forbids incrementing a pointer of type %qT")
4274 : G_("ISO C++ forbids decrementing a pointer of type %qT"),
4276 inc = cxx_sizeof_nowarn (TREE_TYPE (argtype));
4279 inc = integer_one_node;
4281 inc = cp_convert (argtype, inc);
4283 /* Handle incrementing a cast-expression. */
4285 switch (TREE_CODE (arg))
4290 case FIX_TRUNC_EXPR:
4292 tree incremented, modify, value, compound;
4293 if (! lvalue_p (arg) && pedantic)
4294 pedwarn ("cast to non-reference type used as lvalue");
4295 arg = stabilize_reference (arg);
4296 if (code == PREINCREMENT_EXPR || code == PREDECREMENT_EXPR)
4299 value = save_expr (arg);
4300 incremented = build2 (((code == PREINCREMENT_EXPR
4301 || code == POSTINCREMENT_EXPR)
4302 ? PLUS_EXPR : MINUS_EXPR),
4303 argtype, value, inc);
4305 modify = build_modify_expr (arg, NOP_EXPR, incremented);
4306 compound = build2 (COMPOUND_EXPR, TREE_TYPE (arg),
4309 /* Eliminate warning about unused result of + or -. */
4310 TREE_NO_WARNING (compound) = 1;
4318 /* Complain about anything else that is not a true lvalue. */
4319 if (!lvalue_or_else (arg, ((code == PREINCREMENT_EXPR
4320 || code == POSTINCREMENT_EXPR)
4321 ? lv_increment : lv_decrement)))
4322 return error_mark_node;
4324 /* Forbid using -- on `bool'. */
4325 if (same_type_p (declared_type, boolean_type_node))
4327 if (code == POSTDECREMENT_EXPR || code == PREDECREMENT_EXPR)
4329 error ("invalid use of %<--%> on bool variable %qD", arg);
4330 return error_mark_node;
4332 val = boolean_increment (code, arg);
4335 val = build2 (code, TREE_TYPE (arg), arg, inc);
4337 TREE_SIDE_EFFECTS (val) = 1;
4338 return cp_convert (result_type, val);
4342 /* Note that this operation never does default_conversion
4343 regardless of NOCONVERT. */
4345 argtype = lvalue_type (arg);
4347 if (TREE_CODE (arg) == OFFSET_REF)
4350 if (TREE_CODE (argtype) == REFERENCE_TYPE)
4352 tree type = build_pointer_type (TREE_TYPE (argtype));
4353 arg = build1 (CONVERT_EXPR, type, arg);
4356 else if (pedantic && DECL_MAIN_P (arg))
4358 pedwarn ("ISO C++ forbids taking address of function %<::main%>");
4360 /* Let &* cancel out to simplify resulting code. */
4361 if (TREE_CODE (arg) == INDIRECT_REF)
4363 /* We don't need to have `current_class_ptr' wrapped in a
4364 NON_LVALUE_EXPR node. */
4365 if (arg == current_class_ref)
4366 return current_class_ptr;
4368 arg = TREE_OPERAND (arg, 0);
4369 if (TREE_CODE (TREE_TYPE (arg)) == REFERENCE_TYPE)
4371 tree type = build_pointer_type (TREE_TYPE (TREE_TYPE (arg)));
4372 arg = build1 (CONVERT_EXPR, type, arg);
4375 /* Don't let this be an lvalue. */
4380 /* Uninstantiated types are all functions. Taking the
4381 address of a function is a no-op, so just return the
4384 gcc_assert (TREE_CODE (arg) != IDENTIFIER_NODE
4385 || !IDENTIFIER_OPNAME_P (arg));
4387 if (TREE_CODE (arg) == COMPONENT_REF && type_unknown_p (arg)
4388 && !really_overloaded_fn (TREE_OPERAND (arg, 1)))
4390 /* They're trying to take the address of a unique non-static
4391 member function. This is ill-formed (except in MS-land),
4392 but let's try to DTRT.
4393 Note: We only handle unique functions here because we don't
4394 want to complain if there's a static overload; non-unique
4395 cases will be handled by instantiate_type. But we need to
4396 handle this case here to allow casts on the resulting PMF.
4397 We could defer this in non-MS mode, but it's easier to give
4398 a useful error here. */
4400 /* Inside constant member functions, the `this' pointer
4401 contains an extra const qualifier. TYPE_MAIN_VARIANT
4402 is used here to remove this const from the diagnostics
4403 and the created OFFSET_REF. */
4404 tree base = TYPE_MAIN_VARIANT (TREE_TYPE (TREE_OPERAND (arg, 0)));
4405 tree fn = get_first_fn (TREE_OPERAND (arg, 1));
4408 if (! flag_ms_extensions)
4410 tree name = DECL_NAME (fn);
4411 if (current_class_type
4412 && TREE_OPERAND (arg, 0) == current_class_ref)
4413 /* An expression like &memfn. */
4414 pedwarn ("ISO C++ forbids taking the address of an unqualified"
4415 " or parenthesized non-static member function to form"
4416 " a pointer to member function. Say %<&%T::%D%>",
4419 pedwarn ("ISO C++ forbids taking the address of a bound member"
4420 " function to form a pointer to member function."
4424 arg = build_offset_ref (base, fn, /*address_p=*/true);
4428 if (type_unknown_p (arg))
4429 return build1 (ADDR_EXPR, unknown_type_node, arg);
4431 /* Handle complex lvalues (when permitted)
4432 by reduction to simpler cases. */
4433 val = unary_complex_lvalue (code, arg);
4437 switch (TREE_CODE (arg))
4442 case FIX_TRUNC_EXPR:
4443 if (! lvalue_p (arg) && pedantic)
4444 pedwarn ("ISO C++ forbids taking the address of a cast to a non-lvalue expression");
4448 arg = BASELINK_FUNCTIONS (arg);
4452 arg = OVL_CURRENT (arg);
4456 /* Turn a reference to a non-static data member into a
4457 pointer-to-member. */
4462 if (!PTRMEM_OK_P (arg))
4463 return build_unary_op (code, arg, 0);
4465 t = TREE_OPERAND (arg, 1);
4466 if (TREE_CODE (TREE_TYPE (t)) == REFERENCE_TYPE)
4468 error ("cannot create pointer to reference member %qD", t);
4469 return error_mark_node;
4472 type = build_ptrmem_type (context_for_name_lookup (t),
4474 t = make_ptrmem_cst (type, TREE_OPERAND (arg, 1));
4482 /* Anything not already handled and not a true memory reference
4484 if (TREE_CODE (argtype) != FUNCTION_TYPE
4485 && TREE_CODE (argtype) != METHOD_TYPE
4486 && TREE_CODE (arg) != OFFSET_REF
4487 && !lvalue_or_else (arg, lv_addressof))
4488 return error_mark_node;
4490 if (argtype != error_mark_node)
4491 argtype = build_pointer_type (argtype);
4493 /* In a template, we are processing a non-dependent expression
4494 so we can just form an ADDR_EXPR with the correct type. */
4495 if (processing_template_decl)
4497 val = build_address (arg);
4498 if (TREE_CODE (arg) == OFFSET_REF)
4499 PTRMEM_OK_P (val) = PTRMEM_OK_P (arg);
4503 if (TREE_CODE (arg) != COMPONENT_REF)
4505 val = build_address (arg);
4506 if (TREE_CODE (arg) == OFFSET_REF)
4507 PTRMEM_OK_P (val) = PTRMEM_OK_P (arg);
4509 else if (TREE_CODE (TREE_OPERAND (arg, 1)) == BASELINK)
4511 tree fn = BASELINK_FUNCTIONS (TREE_OPERAND (arg, 1));
4513 /* We can only get here with a single static member
4515 gcc_assert (TREE_CODE (fn) == FUNCTION_DECL
4516 && DECL_STATIC_FUNCTION_P (fn));
4518 val = build_address (fn);
4519 if (TREE_SIDE_EFFECTS (TREE_OPERAND (arg, 0)))
4520 /* Do not lose object's side effects. */
4521 val = build2 (COMPOUND_EXPR, TREE_TYPE (val),
4522 TREE_OPERAND (arg, 0), val);
4524 else if (DECL_C_BIT_FIELD (TREE_OPERAND (arg, 1)))
4526 error ("attempt to take address of bit-field structure member %qD",
4527 TREE_OPERAND (arg, 1));
4528 return error_mark_node;
4532 tree object = TREE_OPERAND (arg, 0);
4533 tree field = TREE_OPERAND (arg, 1);
4534 gcc_assert (same_type_ignoring_top_level_qualifiers_p
4535 (TREE_TYPE (object), decl_type_context (field)));
4536 val = build_address (arg);
4539 if (TREE_CODE (argtype) == POINTER_TYPE
4540 && TREE_CODE (TREE_TYPE (argtype)) == METHOD_TYPE)
4542 build_ptrmemfunc_type (argtype);
4543 val = build_ptrmemfunc (argtype, val, 0,
4544 /*c_cast_p=*/false);
4556 argtype = TREE_TYPE (arg);
4557 return fold_if_not_in_template (build1 (code, argtype, arg));
4560 error ("%s", errstring);
4561 return error_mark_node;
4564 /* Apply unary lvalue-demanding operator CODE to the expression ARG
4565 for certain kinds of expressions which are not really lvalues
4566 but which we can accept as lvalues.
4568 If ARG is not a kind of expression we can handle, return
4572 unary_complex_lvalue (enum tree_code code, tree arg)
4574 /* Inside a template, making these kinds of adjustments is
4575 pointless; we are only concerned with the type of the
4577 if (processing_template_decl)
4580 /* Handle (a, b) used as an "lvalue". */
4581 if (TREE_CODE (arg) == COMPOUND_EXPR)
4583 tree real_result = build_unary_op (code, TREE_OPERAND (arg, 1), 0);
4584 return build2 (COMPOUND_EXPR, TREE_TYPE (real_result),
4585 TREE_OPERAND (arg, 0), real_result);
4588 /* Handle (a ? b : c) used as an "lvalue". */
4589 if (TREE_CODE (arg) == COND_EXPR
4590 || TREE_CODE (arg) == MIN_EXPR || TREE_CODE (arg) == MAX_EXPR)
4591 return rationalize_conditional_expr (code, arg);
4593 /* Handle (a = b), (++a), and (--a) used as an "lvalue". */
4594 if (TREE_CODE (arg) == MODIFY_EXPR
4595 || TREE_CODE (arg) == PREINCREMENT_EXPR
4596 || TREE_CODE (arg) == PREDECREMENT_EXPR)
4598 tree lvalue = TREE_OPERAND (arg, 0);
4599 if (TREE_SIDE_EFFECTS (lvalue))
4601 lvalue = stabilize_reference (lvalue);
4602 arg = build2 (TREE_CODE (arg), TREE_TYPE (arg),
4603 lvalue, TREE_OPERAND (arg, 1));
4605 return unary_complex_lvalue
4606 (code, build2 (COMPOUND_EXPR, TREE_TYPE (lvalue), arg, lvalue));
4609 if (code != ADDR_EXPR)
4612 /* Handle (a = b) used as an "lvalue" for `&'. */
4613 if (TREE_CODE (arg) == MODIFY_EXPR
4614 || TREE_CODE (arg) == INIT_EXPR)
4616 tree real_result = build_unary_op (code, TREE_OPERAND (arg, 0), 0);
4617 arg = build2 (COMPOUND_EXPR, TREE_TYPE (real_result),
4619 TREE_NO_WARNING (arg) = 1;
4623 if (TREE_CODE (TREE_TYPE (arg)) == FUNCTION_TYPE
4624 || TREE_CODE (TREE_TYPE (arg)) == METHOD_TYPE
4625 || TREE_CODE (arg) == OFFSET_REF)
4628 /* We permit compiler to make function calls returning
4629 objects of aggregate type look like lvalues. */
4633 if (TREE_CODE (targ) == SAVE_EXPR)
4634 targ = TREE_OPERAND (targ, 0);
4636 if (TREE_CODE (targ) == CALL_EXPR && IS_AGGR_TYPE (TREE_TYPE (targ)))
4638 if (TREE_CODE (arg) == SAVE_EXPR)
4641 targ = build_cplus_new (TREE_TYPE (arg), arg);
4642 return build1 (ADDR_EXPR, build_pointer_type (TREE_TYPE (arg)), targ);
4645 if (TREE_CODE (arg) == SAVE_EXPR && TREE_CODE (targ) == INDIRECT_REF)
4646 return build3 (SAVE_EXPR, build_pointer_type (TREE_TYPE (arg)),
4647 TREE_OPERAND (targ, 0), current_function_decl, NULL);
4650 /* Don't let anything else be handled specially. */
4654 /* Mark EXP saying that we need to be able to take the
4655 address of it; it should not be allocated in a register.
4656 Value is true if successful.
4658 C++: we do not allow `current_class_ptr' to be addressable. */
4661 cxx_mark_addressable (tree exp)
4666 switch (TREE_CODE (x))
4673 x = TREE_OPERAND (x, 0);
4677 if (x == current_class_ptr)
4679 error ("cannot take the address of %<this%>, which is an rvalue expression");
4680 TREE_ADDRESSABLE (x) = 1; /* so compiler doesn't die later. */
4686 /* Caller should not be trying to mark initialized
4687 constant fields addressable. */
4688 gcc_assert (DECL_LANG_SPECIFIC (x) == 0
4689 || DECL_IN_AGGR_P (x) == 0
4691 || DECL_EXTERNAL (x));
4696 if (DECL_REGISTER (x) && !TREE_ADDRESSABLE (x)
4697 && !DECL_ARTIFICIAL (x))
4699 if (TREE_CODE (x) == VAR_DECL && DECL_HARD_REGISTER (x))
4702 ("address of explicit register variable %qD requested", x);
4705 else if (extra_warnings)
4707 (OPT_Wextra, "address requested for %qD, which is declared %<register%>", x);
4709 TREE_ADDRESSABLE (x) = 1;
4713 TREE_ADDRESSABLE (x) = 1;
4717 TREE_ADDRESSABLE (x) = 1;
4721 TREE_ADDRESSABLE (x) = 1;
4722 cxx_mark_addressable (TREE_OPERAND (x, 0));
4730 /* Build and return a conditional expression IFEXP ? OP1 : OP2. */
4733 build_x_conditional_expr (tree ifexp, tree op1, tree op2)
4735 tree orig_ifexp = ifexp;
4736 tree orig_op1 = op1;
4737 tree orig_op2 = op2;
4740 if (processing_template_decl)
4742 /* The standard says that the expression is type-dependent if
4743 IFEXP is type-dependent, even though the eventual type of the
4744 expression doesn't dependent on IFEXP. */
4745 if (type_dependent_expression_p (ifexp)
4746 /* As a GNU extension, the middle operand may be omitted. */
4747 || (op1 && type_dependent_expression_p (op1))
4748 || type_dependent_expression_p (op2))
4749 return build_min_nt (COND_EXPR, ifexp, op1, op2);
4750 ifexp = build_non_dependent_expr (ifexp);
4752 op1 = build_non_dependent_expr (op1);
4753 op2 = build_non_dependent_expr (op2);
4756 expr = build_conditional_expr (ifexp, op1, op2);
4757 if (processing_template_decl && expr != error_mark_node)
4758 return build_min_non_dep (COND_EXPR, expr,
4759 orig_ifexp, orig_op1, orig_op2);
4763 /* Given a list of expressions, return a compound expression
4764 that performs them all and returns the value of the last of them. */
4766 tree build_x_compound_expr_from_list (tree list, const char *msg)
4768 tree expr = TREE_VALUE (list);
4770 if (TREE_CHAIN (list))
4773 pedwarn ("%s expression list treated as compound expression", msg);
4775 for (list = TREE_CHAIN (list); list; list = TREE_CHAIN (list))
4776 expr = build_x_compound_expr (expr, TREE_VALUE (list));
4782 /* Handle overloading of the ',' operator when needed. */
4785 build_x_compound_expr (tree op1, tree op2)
4788 tree orig_op1 = op1;
4789 tree orig_op2 = op2;
4791 if (processing_template_decl)
4793 if (type_dependent_expression_p (op1)
4794 || type_dependent_expression_p (op2))
4795 return build_min_nt (COMPOUND_EXPR, op1, op2);
4796 op1 = build_non_dependent_expr (op1);
4797 op2 = build_non_dependent_expr (op2);
4800 result = build_new_op (COMPOUND_EXPR, LOOKUP_NORMAL, op1, op2, NULL_TREE,
4801 /*overloaded_p=*/NULL);
4803 result = build_compound_expr (op1, op2);
4805 if (processing_template_decl && result != error_mark_node)
4806 return build_min_non_dep (COMPOUND_EXPR, result, orig_op1, orig_op2);
4811 /* Build a compound expression. */
4814 build_compound_expr (tree lhs, tree rhs)
4816 lhs = convert_to_void (lhs, "left-hand operand of comma");
4818 if (lhs == error_mark_node || rhs == error_mark_node)
4819 return error_mark_node;
4821 if (TREE_CODE (rhs) == TARGET_EXPR)
4823 /* If the rhs is a TARGET_EXPR, then build the compound
4824 expression inside the target_expr's initializer. This
4825 helps the compiler to eliminate unnecessary temporaries. */
4826 tree init = TREE_OPERAND (rhs, 1);
4828 init = build2 (COMPOUND_EXPR, TREE_TYPE (init), lhs, init);
4829 TREE_OPERAND (rhs, 1) = init;
4834 return build2 (COMPOUND_EXPR, TREE_TYPE (rhs), lhs, rhs);
4837 /* Issue a diagnostic message if casting from SRC_TYPE to DEST_TYPE
4838 casts away constness. DIAG_FN gives the function to call if we
4839 need to issue a diagnostic; if it is NULL, no diagnostic will be
4840 issued. DESCRIPTION explains what operation is taking place. */
4843 check_for_casting_away_constness (tree src_type, tree dest_type,
4844 void (*diag_fn)(const char *, ...) ATTRIBUTE_GCC_CXXDIAG(1,2),
4845 const char *description)
4847 if (diag_fn && casts_away_constness (src_type, dest_type))
4848 diag_fn ("%s from type %qT to type %qT casts away constness",
4849 description, src_type, dest_type);
4852 /* Convert EXPR (an expression with pointer-to-member type) to TYPE
4853 (another pointer-to-member type in the same hierarchy) and return
4854 the converted expression. If ALLOW_INVERSE_P is permitted, a
4855 pointer-to-derived may be converted to pointer-to-base; otherwise,
4856 only the other direction is permitted. If C_CAST_P is true, this
4857 conversion is taking place as part of a C-style cast. */
4860 convert_ptrmem (tree type, tree expr, bool allow_inverse_p,
4863 if (TYPE_PTRMEM_P (type))
4867 if (TREE_CODE (expr) == PTRMEM_CST)
4868 expr = cplus_expand_constant (expr);
4869 delta = get_delta_difference (TYPE_PTRMEM_CLASS_TYPE (TREE_TYPE (expr)),
4870 TYPE_PTRMEM_CLASS_TYPE (type),
4873 if (!integer_zerop (delta))
4874 expr = cp_build_binary_op (PLUS_EXPR,
4875 build_nop (ptrdiff_type_node, expr),
4877 return build_nop (type, expr);
4880 return build_ptrmemfunc (TYPE_PTRMEMFUNC_FN_TYPE (type), expr,
4881 allow_inverse_p, c_cast_p);
4884 /* If EXPR is an INTEGER_CST and ORIG is an arithmetic constant, return
4885 a version of EXPR that has TREE_OVERFLOW set if it is set in ORIG.
4886 Otherwise, return EXPR unchanged. */
4889 ignore_overflows (tree expr, tree orig)
4891 if (TREE_CODE (expr) == INTEGER_CST
4892 && CONSTANT_CLASS_P (orig)
4893 && TREE_CODE (orig) != STRING_CST
4894 && TREE_OVERFLOW (expr) != TREE_OVERFLOW (orig))
4896 if (!TREE_OVERFLOW (orig))
4897 /* Ensure constant sharing. */
4898 expr = build_int_cst_wide (TREE_TYPE (expr),
4899 TREE_INT_CST_LOW (expr),
4900 TREE_INT_CST_HIGH (expr));
4903 /* Avoid clobbering a shared constant. */
4904 expr = copy_node (expr);
4905 TREE_OVERFLOW (expr) = TREE_OVERFLOW (orig);
4911 /* Perform a static_cast from EXPR to TYPE. When C_CAST_P is true,
4912 this static_cast is being attempted as one of the possible casts
4913 allowed by a C-style cast. (In that case, accessibility of base
4914 classes is not considered, and it is OK to cast away
4915 constness.) Return the result of the cast. *VALID_P is set to
4916 indicate whether or not the cast was valid. */
4919 build_static_cast_1 (tree type, tree expr, bool c_cast_p,
4925 void (*diag_fn)(const char*, ...) ATTRIBUTE_GCC_CXXDIAG(1,2);
4928 /* Assume the cast is valid. */
4931 intype = TREE_TYPE (expr);
4933 /* Save casted types in the function's used types hash table. */
4934 used_types_insert (type);
4936 /* Determine what to do when casting away constness. */
4939 /* C-style casts are allowed to cast away constness. With
4940 WARN_CAST_QUAL, we still want to issue a warning. */
4941 diag_fn = warn_cast_qual ? warning0 : NULL;
4946 /* A static_cast may not cast away constness. */
4948 desc = "static_cast";
4951 /* [expr.static.cast]
4953 An lvalue of type "cv1 B", where B is a class type, can be cast
4954 to type "reference to cv2 D", where D is a class derived (clause
4955 _class.derived_) from B, if a valid standard conversion from
4956 "pointer to D" to "pointer to B" exists (_conv.ptr_), cv2 is the
4957 same cv-qualification as, or greater cv-qualification than, cv1,
4958 and B is not a virtual base class of D. */
4959 /* We check this case before checking the validity of "TYPE t =
4960 EXPR;" below because for this case:
4963 struct D : public B { D(const B&); };
4965 void f() { static_cast<const D&>(b); }
4967 we want to avoid constructing a new D. The standard is not
4968 completely clear about this issue, but our interpretation is
4969 consistent with other compilers. */
4970 if (TREE_CODE (type) == REFERENCE_TYPE
4971 && CLASS_TYPE_P (TREE_TYPE (type))
4972 && CLASS_TYPE_P (intype)
4973 && real_lvalue_p (expr)
4974 && DERIVED_FROM_P (intype, TREE_TYPE (type))
4975 && can_convert (build_pointer_type (TYPE_MAIN_VARIANT (intype)),
4976 build_pointer_type (TYPE_MAIN_VARIANT
4977 (TREE_TYPE (type))))
4979 || at_least_as_qualified_p (TREE_TYPE (type), intype)))
4983 /* There is a standard conversion from "D*" to "B*" even if "B"
4984 is ambiguous or inaccessible. If this is really a
4985 static_cast, then we check both for inaccessibility and
4986 ambiguity. However, if this is a static_cast being performed
4987 because the user wrote a C-style cast, then accessibility is
4989 base = lookup_base (TREE_TYPE (type), intype,
4990 c_cast_p ? ba_unique : ba_check,
4993 /* Convert from "B*" to "D*". This function will check that "B"
4994 is not a virtual base of "D". */
4995 expr = build_base_path (MINUS_EXPR, build_address (expr),
4996 base, /*nonnull=*/false);
4997 /* Convert the pointer to a reference -- but then remember that
4998 there are no expressions with reference type in C++. */
4999 return convert_from_reference (build_nop (type, expr));
5004 /* [expr.static.cast]
5006 An expression e can be explicitly converted to a type T using a
5007 static_cast of the form static_cast<T>(e) if the declaration T
5008 t(e);" is well-formed, for some invented temporary variable
5010 result = perform_direct_initialization_if_possible (type, expr,
5014 result = convert_from_reference (result);
5016 /* Ignore any integer overflow caused by the cast. */
5017 result = ignore_overflows (result, orig);
5019 /* [expr.static.cast]
5021 If T is a reference type, the result is an lvalue; otherwise,
5022 the result is an rvalue. */
5023 if (TREE_CODE (type) != REFERENCE_TYPE)
5024 result = rvalue (result);
5028 /* [expr.static.cast]
5030 Any expression can be explicitly converted to type cv void. */
5031 if (TREE_CODE (type) == VOID_TYPE)
5032 return convert_to_void (expr, /*implicit=*/NULL);
5034 /* [expr.static.cast]
5036 The inverse of any standard conversion sequence (clause _conv_),
5037 other than the lvalue-to-rvalue (_conv.lval_), array-to-pointer
5038 (_conv.array_), function-to-pointer (_conv.func_), and boolean
5039 (_conv.bool_) conversions, can be performed explicitly using
5040 static_cast subject to the restriction that the explicit
5041 conversion does not cast away constness (_expr.const.cast_), and
5042 the following additional rules for specific cases: */
5043 /* For reference, the conversions not excluded are: integral
5044 promotions, floating point promotion, integral conversions,
5045 floating point conversions, floating-integral conversions,
5046 pointer conversions, and pointer to member conversions. */
5049 A value of integral _or enumeration_ type can be explicitly
5050 converted to an enumeration type. */
5051 /* The effect of all that is that any conversion between any two
5052 types which are integral, floating, or enumeration types can be
5054 if ((INTEGRAL_TYPE_P (type) || SCALAR_FLOAT_TYPE_P (type))
5055 && (INTEGRAL_TYPE_P (intype) || SCALAR_FLOAT_TYPE_P (intype)))
5057 expr = ocp_convert (type, expr, CONV_C_CAST, LOOKUP_NORMAL);
5059 /* Ignore any integer overflow caused by the cast. */
5060 expr = ignore_overflows (expr, orig);
5064 if (TYPE_PTR_P (type) && TYPE_PTR_P (intype)
5065 && CLASS_TYPE_P (TREE_TYPE (type))
5066 && CLASS_TYPE_P (TREE_TYPE (intype))
5067 && can_convert (build_pointer_type (TYPE_MAIN_VARIANT
5068 (TREE_TYPE (intype))),
5069 build_pointer_type (TYPE_MAIN_VARIANT
5070 (TREE_TYPE (type)))))
5075 check_for_casting_away_constness (intype, type, diag_fn, desc);
5076 base = lookup_base (TREE_TYPE (type), TREE_TYPE (intype),
5077 c_cast_p ? ba_unique : ba_check,
5079 return build_base_path (MINUS_EXPR, expr, base, /*nonnull=*/false);
5082 if ((TYPE_PTRMEM_P (type) && TYPE_PTRMEM_P (intype))
5083 || (TYPE_PTRMEMFUNC_P (type) && TYPE_PTRMEMFUNC_P (intype)))
5090 c1 = TYPE_PTRMEM_CLASS_TYPE (intype);
5091 c2 = TYPE_PTRMEM_CLASS_TYPE (type);
5093 if (TYPE_PTRMEM_P (type))
5095 t1 = (build_ptrmem_type
5097 TYPE_MAIN_VARIANT (TYPE_PTRMEM_POINTED_TO_TYPE (intype))));
5098 t2 = (build_ptrmem_type
5100 TYPE_MAIN_VARIANT (TYPE_PTRMEM_POINTED_TO_TYPE (type))));
5107 if (can_convert (t1, t2))
5110 check_for_casting_away_constness (intype, type, diag_fn,
5112 return convert_ptrmem (type, expr, /*allow_inverse_p=*/1,
5117 /* [expr.static.cast]
5119 An rvalue of type "pointer to cv void" can be explicitly
5120 converted to a pointer to object type. A value of type pointer
5121 to object converted to "pointer to cv void" and back to the
5122 original pointer type will have its original value. */
5123 if (TREE_CODE (intype) == POINTER_TYPE
5124 && VOID_TYPE_P (TREE_TYPE (intype))
5125 && TYPE_PTROB_P (type))
5128 check_for_casting_away_constness (intype, type, diag_fn, desc);
5129 return build_nop (type, expr);
5133 return error_mark_node;
5136 /* Return an expression representing static_cast<TYPE>(EXPR). */
5139 build_static_cast (tree type, tree expr)
5144 if (type == error_mark_node || expr == error_mark_node)
5145 return error_mark_node;
5147 if (processing_template_decl)
5149 expr = build_min (STATIC_CAST_EXPR, type, expr);
5150 /* We don't know if it will or will not have side effects. */
5151 TREE_SIDE_EFFECTS (expr) = 1;
5152 return convert_from_reference (expr);
5155 /* build_c_cast puts on a NOP_EXPR to make the result not an lvalue.
5156 Strip such NOP_EXPRs if VALUE is being used in non-lvalue context. */
5157 if (TREE_CODE (type) != REFERENCE_TYPE
5158 && TREE_CODE (expr) == NOP_EXPR
5159 && TREE_TYPE (expr) == TREE_TYPE (TREE_OPERAND (expr, 0)))
5160 expr = TREE_OPERAND (expr, 0);
5162 result = build_static_cast_1 (type, expr, /*c_cast_p=*/false, &valid_p);
5166 error ("invalid static_cast from type %qT to type %qT",
5167 TREE_TYPE (expr), type);
5168 return error_mark_node;
5171 /* EXPR is an expression with member function or pointer-to-member
5172 function type. TYPE is a pointer type. Converting EXPR to TYPE is
5173 not permitted by ISO C++, but we accept it in some modes. If we
5174 are not in one of those modes, issue a diagnostic. Return the
5175 converted expression. */
5178 convert_member_func_to_ptr (tree type, tree expr)
5183 intype = TREE_TYPE (expr);
5184 gcc_assert (TYPE_PTRMEMFUNC_P (intype)
5185 || TREE_CODE (intype) == METHOD_TYPE);
5187 if (pedantic || warn_pmf2ptr)
5188 pedwarn ("converting from %qT to %qT", intype, type);
5190 if (TREE_CODE (intype) == METHOD_TYPE)
5191 expr = build_addr_func (expr);
5192 else if (TREE_CODE (expr) == PTRMEM_CST)
5193 expr = build_address (PTRMEM_CST_MEMBER (expr));
5196 decl = maybe_dummy_object (TYPE_PTRMEM_CLASS_TYPE (intype), 0);
5197 decl = build_address (decl);
5198 expr = get_member_function_from_ptrfunc (&decl, expr);
5201 return build_nop (type, expr);
5204 /* Return a representation for a reinterpret_cast from EXPR to TYPE.
5205 If C_CAST_P is true, this reinterpret cast is being done as part of
5206 a C-style cast. If VALID_P is non-NULL, *VALID_P is set to
5207 indicate whether or not reinterpret_cast was valid. */
5210 build_reinterpret_cast_1 (tree type, tree expr, bool c_cast_p,
5215 /* Assume the cast is invalid. */
5219 if (type == error_mark_node || error_operand_p (expr))
5220 return error_mark_node;
5222 intype = TREE_TYPE (expr);
5224 /* Save casted types in the function's used types hash table. */
5225 used_types_insert (type);
5227 /* [expr.reinterpret.cast]
5228 An lvalue expression of type T1 can be cast to the type
5229 "reference to T2" if an expression of type "pointer to T1" can be
5230 explicitly converted to the type "pointer to T2" using a
5231 reinterpret_cast. */
5232 if (TREE_CODE (type) == REFERENCE_TYPE)
5234 if (! real_lvalue_p (expr))
5236 error ("invalid cast of an rvalue expression of type "
5239 return error_mark_node;
5242 /* Warn about a reinterpret_cast from "A*" to "B&" if "A" and
5243 "B" are related class types; the reinterpret_cast does not
5244 adjust the pointer. */
5245 if (TYPE_PTR_P (intype)
5246 && (comptypes (TREE_TYPE (intype), TREE_TYPE (type),
5247 COMPARE_BASE | COMPARE_DERIVED)))
5248 warning (0, "casting %qT to %qT does not dereference pointer",
5251 expr = build_unary_op (ADDR_EXPR, expr, 0);
5252 if (expr != error_mark_node)
5253 expr = build_reinterpret_cast_1
5254 (build_pointer_type (TREE_TYPE (type)), expr, c_cast_p,
5256 if (expr != error_mark_node)
5257 expr = build_indirect_ref (expr, 0);
5261 /* As a G++ extension, we consider conversions from member
5262 functions, and pointers to member functions to
5263 pointer-to-function and pointer-to-void types. If
5264 -Wno-pmf-conversions has not been specified,
5265 convert_member_func_to_ptr will issue an error message. */
5266 if ((TYPE_PTRMEMFUNC_P (intype)
5267 || TREE_CODE (intype) == METHOD_TYPE)
5268 && TYPE_PTR_P (type)
5269 && (TREE_CODE (TREE_TYPE (type)) == FUNCTION_TYPE
5270 || VOID_TYPE_P (TREE_TYPE (type))))
5271 return convert_member_func_to_ptr (type, expr);
5273 /* If the cast is not to a reference type, the lvalue-to-rvalue,
5274 array-to-pointer, and function-to-pointer conversions are
5276 expr = decay_conversion (expr);
5278 /* build_c_cast puts on a NOP_EXPR to make the result not an lvalue.
5279 Strip such NOP_EXPRs if VALUE is being used in non-lvalue context. */
5280 if (TREE_CODE (expr) == NOP_EXPR
5281 && TREE_TYPE (expr) == TREE_TYPE (TREE_OPERAND (expr, 0)))
5282 expr = TREE_OPERAND (expr, 0);
5284 if (error_operand_p (expr))
5285 return error_mark_node;
5287 intype = TREE_TYPE (expr);
5289 /* [expr.reinterpret.cast]
5290 A pointer can be converted to any integral type large enough to
5292 if (CP_INTEGRAL_TYPE_P (type) && TYPE_PTR_P (intype))
5294 if (TYPE_PRECISION (type) < TYPE_PRECISION (intype))
5295 pedwarn ("cast from %qT to %qT loses precision",
5298 /* [expr.reinterpret.cast]
5299 A value of integral or enumeration type can be explicitly
5300 converted to a pointer. */
5301 else if (TYPE_PTR_P (type) && INTEGRAL_OR_ENUMERATION_TYPE_P (intype))
5304 else if ((TYPE_PTRFN_P (type) && TYPE_PTRFN_P (intype))
5305 || (TYPE_PTRMEMFUNC_P (type) && TYPE_PTRMEMFUNC_P (intype)))
5306 return fold_if_not_in_template (build_nop (type, expr));
5307 else if ((TYPE_PTRMEM_P (type) && TYPE_PTRMEM_P (intype))
5308 || (TYPE_PTROBV_P (type) && TYPE_PTROBV_P (intype)))
5313 check_for_casting_away_constness (intype, type, error,
5314 "reinterpret_cast");
5315 /* Warn about possible alignment problems. */
5316 if (STRICT_ALIGNMENT && warn_cast_align
5317 && !VOID_TYPE_P (type)
5318 && TREE_CODE (TREE_TYPE (intype)) != FUNCTION_TYPE
5319 && COMPLETE_TYPE_P (TREE_TYPE (type))
5320 && COMPLETE_TYPE_P (TREE_TYPE (intype))
5321 && TYPE_ALIGN (TREE_TYPE (type)) > TYPE_ALIGN (TREE_TYPE (intype)))
5322 warning (0, "cast from %qT to %qT increases required alignment of "
5326 /* We need to strip nops here, because the front end likes to
5327 create (int *)&a for array-to-pointer decay, instead of &a[0]. */
5329 strict_aliasing_warning (intype, type, sexpr);
5331 return fold_if_not_in_template (build_nop (type, expr));
5333 else if ((TYPE_PTRFN_P (type) && TYPE_PTROBV_P (intype))
5334 || (TYPE_PTRFN_P (intype) && TYPE_PTROBV_P (type)))
5337 /* Only issue a warning, as we have always supported this
5338 where possible, and it is necessary in some cases. DR 195
5339 addresses this issue, but as of 2004/10/26 is still in
5341 warning (0, "ISO C++ forbids casting between pointer-to-function and pointer-to-object");
5342 return fold_if_not_in_template (build_nop (type, expr));
5344 else if (TREE_CODE (type) == VECTOR_TYPE)
5345 return fold_if_not_in_template (convert_to_vector (type, expr));
5346 else if (TREE_CODE (intype) == VECTOR_TYPE)
5347 return fold_if_not_in_template (convert_to_integer (type, expr));
5352 error ("invalid cast from type %qT to type %qT", intype, type);
5353 return error_mark_node;
5356 return cp_convert (type, expr);
5360 build_reinterpret_cast (tree type, tree expr)
5362 if (type == error_mark_node || expr == error_mark_node)
5363 return error_mark_node;
5365 if (processing_template_decl)
5367 tree t = build_min (REINTERPRET_CAST_EXPR, type, expr);
5369 if (!TREE_SIDE_EFFECTS (t)
5370 && type_dependent_expression_p (expr))
5371 /* There might turn out to be side effects inside expr. */
5372 TREE_SIDE_EFFECTS (t) = 1;
5373 return convert_from_reference (t);
5376 return build_reinterpret_cast_1 (type, expr, /*c_cast_p=*/false,
5380 /* Perform a const_cast from EXPR to TYPE. If the cast is valid,
5381 return an appropriate expression. Otherwise, return
5382 error_mark_node. If the cast is not valid, and COMPLAIN is true,
5383 then a diagnostic will be issued. If VALID_P is non-NULL, we are
5384 performing a C-style cast, its value upon return will indicate
5385 whether or not the conversion succeeded. */
5388 build_const_cast_1 (tree dst_type, tree expr, bool complain,
5392 tree reference_type;
5394 /* Callers are responsible for handling error_mark_node as a
5395 destination type. */
5396 gcc_assert (dst_type != error_mark_node);
5397 /* In a template, callers should be building syntactic
5398 representations of casts, not using this machinery. */
5399 gcc_assert (!processing_template_decl);
5401 /* Assume the conversion is invalid. */
5405 if (!POINTER_TYPE_P (dst_type) && !TYPE_PTRMEM_P (dst_type))
5408 error ("invalid use of const_cast with type %qT, "
5409 "which is not a pointer, "
5410 "reference, nor a pointer-to-data-member type", dst_type);
5411 return error_mark_node;
5414 if (TREE_CODE (TREE_TYPE (dst_type)) == FUNCTION_TYPE)
5417 error ("invalid use of const_cast with type %qT, which is a pointer "
5418 "or reference to a function type", dst_type);
5419 return error_mark_node;
5422 /* Save casted types in the function's used types hash table. */
5423 used_types_insert (dst_type);
5425 src_type = TREE_TYPE (expr);
5426 /* Expressions do not really have reference types. */
5427 if (TREE_CODE (src_type) == REFERENCE_TYPE)
5428 src_type = TREE_TYPE (src_type);
5430 /* [expr.const.cast]
5432 An lvalue of type T1 can be explicitly converted to an lvalue of
5433 type T2 using the cast const_cast<T2&> (where T1 and T2 are object
5434 types) if a pointer to T1 can be explicitly converted to the type
5435 pointer to T2 using a const_cast. */
5436 if (TREE_CODE (dst_type) == REFERENCE_TYPE)
5438 reference_type = dst_type;
5439 if (! real_lvalue_p (expr))
5442 error ("invalid const_cast of an rvalue of type %qT to type %qT",
5443 src_type, dst_type);
5444 return error_mark_node;
5446 dst_type = build_pointer_type (TREE_TYPE (dst_type));
5447 src_type = build_pointer_type (src_type);
5451 reference_type = NULL_TREE;
5452 /* If the destination type is not a reference type, the
5453 lvalue-to-rvalue, array-to-pointer, and function-to-pointer
5454 conversions are performed. */
5455 src_type = type_decays_to (src_type);
5456 if (src_type == error_mark_node)
5457 return error_mark_node;
5460 if ((TYPE_PTR_P (src_type) || TYPE_PTRMEM_P (src_type))
5461 && comp_ptr_ttypes_const (dst_type, src_type))
5466 /* This cast is actually a C-style cast. Issue a warning if
5467 the user is making a potentially unsafe cast. */
5469 check_for_casting_away_constness (src_type, dst_type,
5475 expr = build_unary_op (ADDR_EXPR, expr, 0);
5476 expr = build_nop (reference_type, expr);
5477 return convert_from_reference (expr);
5481 expr = decay_conversion (expr);
5482 /* build_c_cast puts on a NOP_EXPR to make the result not an
5483 lvalue. Strip such NOP_EXPRs if VALUE is being used in
5484 non-lvalue context. */
5485 if (TREE_CODE (expr) == NOP_EXPR
5486 && TREE_TYPE (expr) == TREE_TYPE (TREE_OPERAND (expr, 0)))
5487 expr = TREE_OPERAND (expr, 0);
5488 return build_nop (dst_type, expr);
5493 error ("invalid const_cast from type %qT to type %qT",
5494 src_type, dst_type);
5495 return error_mark_node;
5499 build_const_cast (tree type, tree expr)
5501 if (type == error_mark_node || error_operand_p (expr))
5502 return error_mark_node;
5504 if (processing_template_decl)
5506 tree t = build_min (CONST_CAST_EXPR, type, expr);
5508 if (!TREE_SIDE_EFFECTS (t)
5509 && type_dependent_expression_p (expr))
5510 /* There might turn out to be side effects inside expr. */
5511 TREE_SIDE_EFFECTS (t) = 1;
5512 return convert_from_reference (t);
5515 return build_const_cast_1 (type, expr, /*complain=*/true,
5519 /* Build an expression representing an explicit C-style cast to type
5520 TYPE of expression EXPR. */
5523 build_c_cast (tree type, tree expr)
5529 if (type == error_mark_node || error_operand_p (expr))
5530 return error_mark_node;
5532 if (processing_template_decl)
5534 tree t = build_min (CAST_EXPR, type,
5535 tree_cons (NULL_TREE, value, NULL_TREE));
5536 /* We don't know if it will or will not have side effects. */
5537 TREE_SIDE_EFFECTS (t) = 1;
5538 return convert_from_reference (t);
5541 /* Casts to a (pointer to a) specific ObjC class (or 'id' or
5542 'Class') should always be retained, because this information aids
5543 in method lookup. */
5544 if (objc_is_object_ptr (type)
5545 && objc_is_object_ptr (TREE_TYPE (expr)))
5546 return build_nop (type, expr);
5548 /* build_c_cast puts on a NOP_EXPR to make the result not an lvalue.
5549 Strip such NOP_EXPRs if VALUE is being used in non-lvalue context. */
5550 if (TREE_CODE (type) != REFERENCE_TYPE
5551 && TREE_CODE (value) == NOP_EXPR
5552 && TREE_TYPE (value) == TREE_TYPE (TREE_OPERAND (value, 0)))
5553 value = TREE_OPERAND (value, 0);
5555 if (TREE_CODE (type) == ARRAY_TYPE)
5557 /* Allow casting from T1* to T2[] because Cfront allows it.
5558 NIHCL uses it. It is not valid ISO C++ however. */
5559 if (TREE_CODE (TREE_TYPE (expr)) == POINTER_TYPE)
5561 pedwarn ("ISO C++ forbids casting to an array type %qT", type);
5562 type = build_pointer_type (TREE_TYPE (type));
5566 error ("ISO C++ forbids casting to an array type %qT", type);
5567 return error_mark_node;
5571 if (TREE_CODE (type) == FUNCTION_TYPE
5572 || TREE_CODE (type) == METHOD_TYPE)
5574 error ("invalid cast to function type %qT", type);
5575 return error_mark_node;
5578 /* A C-style cast can be a const_cast. */
5579 result = build_const_cast_1 (type, value, /*complain=*/false,
5584 /* Or a static cast. */
5585 result = build_static_cast_1 (type, value, /*c_cast_p=*/true,
5587 /* Or a reinterpret_cast. */
5589 result = build_reinterpret_cast_1 (type, value, /*c_cast_p=*/true,
5591 /* The static_cast or reinterpret_cast may be followed by a
5594 /* A valid cast may result in errors if, for example, a
5595 conversion to am ambiguous base class is required. */
5596 && !error_operand_p (result))
5600 /* Non-class rvalues always have cv-unqualified type. */
5601 if (!CLASS_TYPE_P (type))
5602 type = TYPE_MAIN_VARIANT (type);
5603 result_type = TREE_TYPE (result);
5604 if (!CLASS_TYPE_P (result_type))
5605 result_type = TYPE_MAIN_VARIANT (result_type);
5606 /* If the type of RESULT does not match TYPE, perform a
5607 const_cast to make it match. If the static_cast or
5608 reinterpret_cast succeeded, we will differ by at most
5609 cv-qualification, so the follow-on const_cast is guaranteed
5611 if (!same_type_p (non_reference (type), non_reference (result_type)))
5613 result = build_const_cast_1 (type, result, false, &valid_p);
5614 gcc_assert (valid_p);
5619 return error_mark_node;
5622 /* Build an assignment expression of lvalue LHS from value RHS.
5623 MODIFYCODE is the code for a binary operator that we use
5624 to combine the old value of LHS with RHS to get the new value.
5625 Or else MODIFYCODE is NOP_EXPR meaning do a simple assignment.
5627 C++: If MODIFYCODE is INIT_EXPR, then leave references unbashed. */
5630 build_modify_expr (tree lhs, enum tree_code modifycode, tree rhs)
5634 tree lhstype = TREE_TYPE (lhs);
5635 tree olhstype = lhstype;
5636 tree olhs = NULL_TREE;
5637 bool plain_assign = (modifycode == NOP_EXPR);
5639 /* Avoid duplicate error messages from operands that had errors. */
5640 if (error_operand_p (lhs) || error_operand_p (rhs))
5641 return error_mark_node;
5643 /* Handle control structure constructs used as "lvalues". */
5644 switch (TREE_CODE (lhs))
5646 /* Handle --foo = 5; as these are valid constructs in C++. */
5647 case PREDECREMENT_EXPR:
5648 case PREINCREMENT_EXPR:
5649 if (TREE_SIDE_EFFECTS (TREE_OPERAND (lhs, 0)))
5650 lhs = build2 (TREE_CODE (lhs), TREE_TYPE (lhs),
5651 stabilize_reference (TREE_OPERAND (lhs, 0)),
5652 TREE_OPERAND (lhs, 1));
5653 return build2 (COMPOUND_EXPR, lhstype,
5655 build_modify_expr (TREE_OPERAND (lhs, 0),
5658 /* Handle (a, b) used as an "lvalue". */
5660 newrhs = build_modify_expr (TREE_OPERAND (lhs, 1),
5662 if (newrhs == error_mark_node)
5663 return error_mark_node;
5664 return build2 (COMPOUND_EXPR, lhstype,
5665 TREE_OPERAND (lhs, 0), newrhs);
5668 if (TREE_SIDE_EFFECTS (TREE_OPERAND (lhs, 0)))
5669 lhs = build2 (TREE_CODE (lhs), TREE_TYPE (lhs),
5670 stabilize_reference (TREE_OPERAND (lhs, 0)),
5671 TREE_OPERAND (lhs, 1));
5672 newrhs = build_modify_expr (TREE_OPERAND (lhs, 0), modifycode, rhs);
5673 if (newrhs == error_mark_node)
5674 return error_mark_node;
5675 return build2 (COMPOUND_EXPR, lhstype, lhs, newrhs);
5679 /* MIN_EXPR and MAX_EXPR are currently only permitted as lvalues,
5680 when neither operand has side-effects. */
5681 if (!lvalue_or_else (lhs, lv_assign))
5682 return error_mark_node;
5684 gcc_assert (!TREE_SIDE_EFFECTS (TREE_OPERAND (lhs, 0))
5685 && !TREE_SIDE_EFFECTS (TREE_OPERAND (lhs, 1)));
5687 lhs = build3 (COND_EXPR, TREE_TYPE (lhs),
5688 build2 (TREE_CODE (lhs) == MIN_EXPR ? LE_EXPR : GE_EXPR,
5690 TREE_OPERAND (lhs, 0),
5691 TREE_OPERAND (lhs, 1)),
5692 TREE_OPERAND (lhs, 0),
5693 TREE_OPERAND (lhs, 1));
5696 /* Handle (a ? b : c) used as an "lvalue". */
5699 /* Produce (a ? (b = rhs) : (c = rhs))
5700 except that the RHS goes through a save-expr
5701 so the code to compute it is only emitted once. */
5703 tree preeval = NULL_TREE;
5705 if (VOID_TYPE_P (TREE_TYPE (rhs)))
5707 error ("void value not ignored as it ought to be");
5708 return error_mark_node;
5711 rhs = stabilize_expr (rhs, &preeval);
5713 /* Check this here to avoid odd errors when trying to convert
5714 a throw to the type of the COND_EXPR. */
5715 if (!lvalue_or_else (lhs, lv_assign))
5716 return error_mark_node;
5718 cond = build_conditional_expr
5719 (TREE_OPERAND (lhs, 0),
5720 build_modify_expr (TREE_OPERAND (lhs, 1),
5722 build_modify_expr (TREE_OPERAND (lhs, 2),
5725 if (cond == error_mark_node)
5727 /* Make sure the code to compute the rhs comes out
5728 before the split. */
5730 cond = build2 (COMPOUND_EXPR, TREE_TYPE (lhs), preeval, cond);
5738 if (modifycode == INIT_EXPR)
5740 if (TREE_CODE (rhs) == CONSTRUCTOR)
5742 if (! same_type_p (TREE_TYPE (rhs), lhstype))
5743 /* Call convert to generate an error; see PR 11063. */
5744 rhs = convert (lhstype, rhs);
5745 result = build2 (INIT_EXPR, lhstype, lhs, rhs);
5746 TREE_SIDE_EFFECTS (result) = 1;
5749 else if (! IS_AGGR_TYPE (lhstype))
5750 /* Do the default thing. */;
5753 result = build_special_member_call (lhs, complete_ctor_identifier,
5754 build_tree_list (NULL_TREE, rhs),
5755 lhstype, LOOKUP_NORMAL);
5756 if (result == NULL_TREE)
5757 return error_mark_node;
5763 lhs = require_complete_type (lhs);
5764 if (lhs == error_mark_node)
5765 return error_mark_node;
5767 if (modifycode == NOP_EXPR)
5769 /* `operator=' is not an inheritable operator. */
5770 if (! IS_AGGR_TYPE (lhstype))
5771 /* Do the default thing. */;
5774 result = build_new_op (MODIFY_EXPR, LOOKUP_NORMAL,
5775 lhs, rhs, make_node (NOP_EXPR),
5776 /*overloaded_p=*/NULL);
5777 if (result == NULL_TREE)
5778 return error_mark_node;
5785 /* A binary op has been requested. Combine the old LHS
5786 value with the RHS producing the value we should actually
5787 store into the LHS. */
5789 gcc_assert (!PROMOTES_TO_AGGR_TYPE (lhstype, REFERENCE_TYPE));
5790 lhs = stabilize_reference (lhs);
5791 newrhs = cp_build_binary_op (modifycode, lhs, rhs);
5792 if (newrhs == error_mark_node)
5794 error (" in evaluation of %<%Q(%#T, %#T)%>", modifycode,
5795 TREE_TYPE (lhs), TREE_TYPE (rhs));
5796 return error_mark_node;
5799 /* Now it looks like a plain assignment. */
5800 modifycode = NOP_EXPR;
5802 gcc_assert (TREE_CODE (lhstype) != REFERENCE_TYPE);
5803 gcc_assert (TREE_CODE (TREE_TYPE (newrhs)) != REFERENCE_TYPE);
5806 /* The left-hand side must be an lvalue. */
5807 if (!lvalue_or_else (lhs, lv_assign))
5808 return error_mark_node;
5810 /* Warn about modifying something that is `const'. Don't warn if
5811 this is initialization. */
5812 if (modifycode != INIT_EXPR
5813 && (TREE_READONLY (lhs) || CP_TYPE_CONST_P (lhstype)
5814 /* Functions are not modifiable, even though they are
5816 || TREE_CODE (TREE_TYPE (lhs)) == FUNCTION_TYPE
5817 || TREE_CODE (TREE_TYPE (lhs)) == METHOD_TYPE
5818 /* If it's an aggregate and any field is const, then it is
5819 effectively const. */
5820 || (CLASS_TYPE_P (lhstype)
5821 && C_TYPE_FIELDS_READONLY (lhstype))))
5822 readonly_error (lhs, "assignment");
5824 /* If storing into a structure or union member, it has probably been
5825 given type `int'. Compute the type that would go with the actual
5826 amount of storage the member occupies. */
5828 if (TREE_CODE (lhs) == COMPONENT_REF
5829 && (TREE_CODE (lhstype) == INTEGER_TYPE
5830 || TREE_CODE (lhstype) == REAL_TYPE
5831 || TREE_CODE (lhstype) == ENUMERAL_TYPE))
5833 lhstype = TREE_TYPE (get_unwidened (lhs, 0));
5835 /* If storing in a field that is in actuality a short or narrower
5836 than one, we must store in the field in its actual type. */
5838 if (lhstype != TREE_TYPE (lhs))
5840 /* Avoid warnings converting integral types back into enums for
5842 if (TREE_CODE (lhstype) == INTEGER_TYPE
5843 && TREE_CODE (olhstype) == ENUMERAL_TYPE)
5845 if (TREE_SIDE_EFFECTS (lhs))
5846 lhs = stabilize_reference (lhs);
5849 lhs = copy_node (lhs);
5850 TREE_TYPE (lhs) = lhstype;
5854 /* Convert new value to destination type. */
5856 if (TREE_CODE (lhstype) == ARRAY_TYPE)
5860 if (!same_or_base_type_p (TYPE_MAIN_VARIANT (lhstype),
5861 TYPE_MAIN_VARIANT (TREE_TYPE (rhs))))
5863 error ("incompatible types in assignment of %qT to %qT",
5864 TREE_TYPE (rhs), lhstype);
5865 return error_mark_node;
5868 /* Allow array assignment in compiler-generated code. */
5869 if (! DECL_ARTIFICIAL (current_function_decl))
5871 /* This routine is used for both initialization and assignment.
5872 Make sure the diagnostic message differentiates the context. */
5873 if (modifycode == INIT_EXPR)
5874 error ("array used as initializer");
5876 error ("invalid array assignment");
5877 return error_mark_node;
5880 from_array = TREE_CODE (TREE_TYPE (newrhs)) == ARRAY_TYPE
5881 ? 1 + (modifycode != INIT_EXPR): 0;
5882 return build_vec_init (lhs, NULL_TREE, newrhs,
5883 /*explicit_default_init_p=*/false,
5887 if (modifycode == INIT_EXPR)
5888 newrhs = convert_for_initialization (lhs, lhstype, newrhs, LOOKUP_NORMAL,
5889 "initialization", NULL_TREE, 0);
5892 /* Avoid warnings on enum bit fields. */
5893 if (TREE_CODE (olhstype) == ENUMERAL_TYPE
5894 && TREE_CODE (lhstype) == INTEGER_TYPE)
5896 newrhs = convert_for_assignment (olhstype, newrhs, "assignment",
5898 newrhs = convert_force (lhstype, newrhs, 0);
5901 newrhs = convert_for_assignment (lhstype, newrhs, "assignment",
5903 if (TREE_CODE (newrhs) == CALL_EXPR
5904 && TYPE_NEEDS_CONSTRUCTING (lhstype))
5905 newrhs = build_cplus_new (lhstype, newrhs);
5907 /* Can't initialize directly from a TARGET_EXPR, since that would
5908 cause the lhs to be constructed twice, and possibly result in
5909 accidental self-initialization. So we force the TARGET_EXPR to be
5910 expanded without a target. */
5911 if (TREE_CODE (newrhs) == TARGET_EXPR)
5912 newrhs = build2 (COMPOUND_EXPR, TREE_TYPE (newrhs), newrhs,
5913 TREE_OPERAND (newrhs, 0));
5916 if (newrhs == error_mark_node)
5917 return error_mark_node;
5919 if (c_dialect_objc () && flag_objc_gc)
5921 result = objc_generate_write_barrier (lhs, modifycode, newrhs);
5927 result = build2 (modifycode == NOP_EXPR ? MODIFY_EXPR : INIT_EXPR,
5928 lhstype, lhs, newrhs);
5930 TREE_SIDE_EFFECTS (result) = 1;
5932 TREE_NO_WARNING (result) = 1;
5934 /* If we got the LHS in a different type for storing in,
5935 convert the result back to the nominal type of LHS
5936 so that the value we return always has the same type
5937 as the LHS argument. */
5939 if (olhstype == TREE_TYPE (result))
5943 result = build2 (COMPOUND_EXPR, olhstype, result, olhs);
5944 TREE_NO_WARNING (result) = 1;
5947 return convert_for_assignment (olhstype, result, "assignment",
5952 build_x_modify_expr (tree lhs, enum tree_code modifycode, tree rhs)
5954 if (processing_template_decl)
5955 return build_min_nt (MODOP_EXPR, lhs,
5956 build_min_nt (modifycode, NULL_TREE, NULL_TREE), rhs);
5958 if (modifycode != NOP_EXPR)
5960 tree rval = build_new_op (MODIFY_EXPR, LOOKUP_NORMAL, lhs, rhs,
5961 make_node (modifycode),
5962 /*overloaded_p=*/NULL);
5965 TREE_NO_WARNING (rval) = 1;
5969 return build_modify_expr (lhs, modifycode, rhs);
5973 /* Get difference in deltas for different pointer to member function
5974 types. Returns an integer constant of type PTRDIFF_TYPE_NODE. If
5975 the conversion is invalid, the constant is zero. If
5976 ALLOW_INVERSE_P is true, then allow reverse conversions as well.
5977 If C_CAST_P is true this conversion is taking place as part of a
5980 Note that the naming of FROM and TO is kind of backwards; the return
5981 value is what we add to a TO in order to get a FROM. They are named
5982 this way because we call this function to find out how to convert from
5983 a pointer to member of FROM to a pointer to member of TO. */
5986 get_delta_difference (tree from, tree to,
5987 bool allow_inverse_p,
5994 /* Assume no conversion is required. */
5995 result = integer_zero_node;
5996 binfo = lookup_base (to, from, c_cast_p ? ba_unique : ba_check, &kind);
5997 if (kind == bk_inaccessible || kind == bk_ambig)
5998 error (" in pointer to member function conversion");
6001 if (kind != bk_via_virtual)
6002 result = BINFO_OFFSET (binfo);
6005 tree virt_binfo = binfo_from_vbase (binfo);
6007 /* This is a reinterpret cast, we choose to do nothing. */
6008 if (allow_inverse_p)
6009 warning (0, "pointer to member cast via virtual base %qT",
6010 BINFO_TYPE (virt_binfo));
6012 error ("pointer to member conversion via virtual base %qT",
6013 BINFO_TYPE (virt_binfo));
6016 else if (same_type_ignoring_top_level_qualifiers_p (from, to))
6017 /* Pointer to member of incomplete class is permitted*/;
6018 else if (!allow_inverse_p)
6020 error_not_base_type (from, to);
6021 error (" in pointer to member conversion");
6025 binfo = lookup_base (from, to, c_cast_p ? ba_unique : ba_check, &kind);
6028 if (kind != bk_via_virtual)
6029 result = size_diffop (size_zero_node, BINFO_OFFSET (binfo));
6032 /* This is a reinterpret cast, we choose to do nothing. */
6033 tree virt_binfo = binfo_from_vbase (binfo);
6035 warning (0, "pointer to member cast via virtual base %qT",
6036 BINFO_TYPE (virt_binfo));
6041 return fold_if_not_in_template (convert_to_integer (ptrdiff_type_node,
6045 /* Return a constructor for the pointer-to-member-function TYPE using
6046 the other components as specified. */
6049 build_ptrmemfunc1 (tree type, tree delta, tree pfn)
6054 VEC(constructor_elt, gc) *v;
6056 /* Pull the FIELD_DECLs out of the type. */
6057 pfn_field = TYPE_FIELDS (type);
6058 delta_field = TREE_CHAIN (pfn_field);
6060 /* Make sure DELTA has the type we want. */
6061 delta = convert_and_check (delta_type_node, delta);
6063 /* Finish creating the initializer. */
6064 v = VEC_alloc(constructor_elt, gc, 2);
6065 CONSTRUCTOR_APPEND_ELT(v, pfn_field, pfn);
6066 CONSTRUCTOR_APPEND_ELT(v, delta_field, delta);
6067 u = build_constructor (type, v);
6068 TREE_CONSTANT (u) = TREE_CONSTANT (pfn) & TREE_CONSTANT (delta);
6069 TREE_INVARIANT (u) = TREE_INVARIANT (pfn) & TREE_INVARIANT (delta);
6070 TREE_STATIC (u) = (TREE_CONSTANT (u)
6071 && (initializer_constant_valid_p (pfn, TREE_TYPE (pfn))
6073 && (initializer_constant_valid_p (delta, TREE_TYPE (delta))
6078 /* Build a constructor for a pointer to member function. It can be
6079 used to initialize global variables, local variable, or used
6080 as a value in expressions. TYPE is the POINTER to METHOD_TYPE we
6083 If FORCE is nonzero, then force this conversion, even if
6084 we would rather not do it. Usually set when using an explicit
6085 cast. A C-style cast is being processed iff C_CAST_P is true.
6087 Return error_mark_node, if something goes wrong. */
6090 build_ptrmemfunc (tree type, tree pfn, int force, bool c_cast_p)
6096 if (error_operand_p (pfn))
6097 return error_mark_node;
6099 pfn_type = TREE_TYPE (pfn);
6100 to_type = build_ptrmemfunc_type (type);
6102 /* Handle multiple conversions of pointer to member functions. */
6103 if (TYPE_PTRMEMFUNC_P (pfn_type))
6105 tree delta = NULL_TREE;
6106 tree npfn = NULL_TREE;
6110 && !can_convert_arg (to_type, TREE_TYPE (pfn), pfn, LOOKUP_NORMAL))
6111 error ("invalid conversion to type %qT from type %qT",
6114 n = get_delta_difference (TYPE_PTRMEMFUNC_OBJECT_TYPE (pfn_type),
6115 TYPE_PTRMEMFUNC_OBJECT_TYPE (to_type),
6119 /* We don't have to do any conversion to convert a
6120 pointer-to-member to its own type. But, we don't want to
6121 just return a PTRMEM_CST if there's an explicit cast; that
6122 cast should make the expression an invalid template argument. */
6123 if (TREE_CODE (pfn) != PTRMEM_CST)
6125 if (same_type_p (to_type, pfn_type))
6127 else if (integer_zerop (n))
6128 return build_reinterpret_cast (to_type, pfn);
6131 if (TREE_SIDE_EFFECTS (pfn))
6132 pfn = save_expr (pfn);
6134 /* Obtain the function pointer and the current DELTA. */
6135 if (TREE_CODE (pfn) == PTRMEM_CST)
6136 expand_ptrmemfunc_cst (pfn, &delta, &npfn);
6139 npfn = build_ptrmemfunc_access_expr (pfn, pfn_identifier);
6140 delta = build_ptrmemfunc_access_expr (pfn, delta_identifier);
6143 /* Just adjust the DELTA field. */
6144 gcc_assert (same_type_ignoring_top_level_qualifiers_p
6145 (TREE_TYPE (delta), ptrdiff_type_node));
6146 if (TARGET_PTRMEMFUNC_VBIT_LOCATION == ptrmemfunc_vbit_in_delta)
6147 n = cp_build_binary_op (LSHIFT_EXPR, n, integer_one_node);
6148 delta = cp_build_binary_op (PLUS_EXPR, delta, n);
6149 return build_ptrmemfunc1 (to_type, delta, npfn);
6152 /* Handle null pointer to member function conversions. */
6153 if (integer_zerop (pfn))
6155 pfn = build_c_cast (type, integer_zero_node);
6156 return build_ptrmemfunc1 (to_type,
6161 if (type_unknown_p (pfn))
6162 return instantiate_type (type, pfn, tf_warning_or_error);
6164 fn = TREE_OPERAND (pfn, 0);
6165 gcc_assert (TREE_CODE (fn) == FUNCTION_DECL
6166 /* In a template, we will have preserved the
6168 || (processing_template_decl && TREE_CODE (fn) == OFFSET_REF));
6169 return make_ptrmem_cst (to_type, fn);
6172 /* Return the DELTA, IDX, PFN, and DELTA2 values for the PTRMEM_CST
6175 ??? There is no consistency as to the types returned for the above
6176 values. Some code acts as if it were a sizetype and some as if it were
6177 integer_type_node. */
6180 expand_ptrmemfunc_cst (tree cst, tree *delta, tree *pfn)
6182 tree type = TREE_TYPE (cst);
6183 tree fn = PTRMEM_CST_MEMBER (cst);
6184 tree ptr_class, fn_class;
6186 gcc_assert (TREE_CODE (fn) == FUNCTION_DECL);
6188 /* The class that the function belongs to. */
6189 fn_class = DECL_CONTEXT (fn);
6191 /* The class that we're creating a pointer to member of. */
6192 ptr_class = TYPE_PTRMEMFUNC_OBJECT_TYPE (type);
6194 /* First, calculate the adjustment to the function's class. */
6195 *delta = get_delta_difference (fn_class, ptr_class, /*force=*/0,
6198 if (!DECL_VIRTUAL_P (fn))
6199 *pfn = convert (TYPE_PTRMEMFUNC_FN_TYPE (type), build_addr_func (fn));
6202 /* If we're dealing with a virtual function, we have to adjust 'this'
6203 again, to point to the base which provides the vtable entry for
6204 fn; the call will do the opposite adjustment. */
6205 tree orig_class = DECL_CONTEXT (fn);
6206 tree binfo = binfo_or_else (orig_class, fn_class);
6207 *delta = build2 (PLUS_EXPR, TREE_TYPE (*delta),
6208 *delta, BINFO_OFFSET (binfo));
6209 *delta = fold_if_not_in_template (*delta);
6211 /* We set PFN to the vtable offset at which the function can be
6212 found, plus one (unless ptrmemfunc_vbit_in_delta, in which
6213 case delta is shifted left, and then incremented). */
6214 *pfn = DECL_VINDEX (fn);
6215 *pfn = build2 (MULT_EXPR, integer_type_node, *pfn,
6216 TYPE_SIZE_UNIT (vtable_entry_type));
6217 *pfn = fold_if_not_in_template (*pfn);
6219 switch (TARGET_PTRMEMFUNC_VBIT_LOCATION)
6221 case ptrmemfunc_vbit_in_pfn:
6222 *pfn = build2 (PLUS_EXPR, integer_type_node, *pfn,
6224 *pfn = fold_if_not_in_template (*pfn);
6227 case ptrmemfunc_vbit_in_delta:
6228 *delta = build2 (LSHIFT_EXPR, TREE_TYPE (*delta),
6229 *delta, integer_one_node);
6230 *delta = fold_if_not_in_template (*delta);
6231 *delta = build2 (PLUS_EXPR, TREE_TYPE (*delta),
6232 *delta, integer_one_node);
6233 *delta = fold_if_not_in_template (*delta);
6240 *pfn = build_nop (TYPE_PTRMEMFUNC_FN_TYPE (type), *pfn);
6241 *pfn = fold_if_not_in_template (*pfn);
6245 /* Return an expression for PFN from the pointer-to-member function
6249 pfn_from_ptrmemfunc (tree t)
6251 if (TREE_CODE (t) == PTRMEM_CST)
6256 expand_ptrmemfunc_cst (t, &delta, &pfn);
6261 return build_ptrmemfunc_access_expr (t, pfn_identifier);
6264 /* Convert value RHS to type TYPE as preparation for an assignment to
6265 an lvalue of type TYPE. ERRTYPE is a string to use in error
6266 messages: "assignment", "return", etc. If FNDECL is non-NULL, we
6267 are doing the conversion in order to pass the PARMNUMth argument of
6271 convert_for_assignment (tree type, tree rhs,
6272 const char *errtype, tree fndecl, int parmnum)
6275 enum tree_code coder;
6277 /* Strip NON_LVALUE_EXPRs since we aren't using as an lvalue. */
6278 if (TREE_CODE (rhs) == NON_LVALUE_EXPR)
6279 rhs = TREE_OPERAND (rhs, 0);
6281 rhstype = TREE_TYPE (rhs);
6282 coder = TREE_CODE (rhstype);
6284 if (TREE_CODE (type) == VECTOR_TYPE && coder == VECTOR_TYPE
6285 && vector_types_convertible_p (type, rhstype, true))
6286 return convert (type, rhs);
6288 if (rhs == error_mark_node || rhstype == error_mark_node)
6289 return error_mark_node;
6290 if (TREE_CODE (rhs) == TREE_LIST && TREE_VALUE (rhs) == error_mark_node)
6291 return error_mark_node;
6293 /* The RHS of an assignment cannot have void type. */
6294 if (coder == VOID_TYPE)
6296 error ("void value not ignored as it ought to be");
6297 return error_mark_node;
6300 /* Simplify the RHS if possible. */
6301 if (TREE_CODE (rhs) == CONST_DECL)
6302 rhs = DECL_INITIAL (rhs);
6304 if (c_dialect_objc ())
6307 tree rname = fndecl;
6309 if (!strcmp (errtype, "assignment"))
6311 else if (!strcmp (errtype, "initialization"))
6315 tree selector = objc_message_selector ();
6319 if (selector && parmno > 1)
6326 if (objc_compare_types (type, rhstype, parmno, rname))
6327 return convert (type, rhs);
6332 The expression is implicitly converted (clause _conv_) to the
6333 cv-unqualified type of the left operand.
6335 We allow bad conversions here because by the time we get to this point
6336 we are committed to doing the conversion. If we end up doing a bad
6337 conversion, convert_like will complain. */
6338 if (!can_convert_arg_bad (type, rhstype, rhs))
6340 /* When -Wno-pmf-conversions is use, we just silently allow
6341 conversions from pointers-to-members to plain pointers. If
6342 the conversion doesn't work, cp_convert will complain. */
6344 && TYPE_PTR_P (type)
6345 && TYPE_PTRMEMFUNC_P (rhstype))
6346 rhs = cp_convert (strip_top_quals (type), rhs);
6349 /* If the right-hand side has unknown type, then it is an
6350 overloaded function. Call instantiate_type to get error
6352 if (rhstype == unknown_type_node)
6353 instantiate_type (type, rhs, tf_warning_or_error);
6355 error ("cannot convert %qT to %qT for argument %qP to %qD",
6356 rhstype, type, parmnum, fndecl);
6358 error ("cannot convert %qT to %qT in %s", rhstype, type, errtype);
6359 return error_mark_node;
6362 if (warn_missing_format_attribute)
6364 const enum tree_code codel = TREE_CODE (type);
6365 if ((codel == POINTER_TYPE || codel == REFERENCE_TYPE)
6367 && check_missing_format_attribute (type, rhstype))
6368 warning (OPT_Wmissing_format_attribute,
6369 "%s might be a candidate for a format attribute",
6373 /* If -Wparentheses, warn about a = b = c when a has type bool and b
6375 if (warn_parentheses
6376 && type == boolean_type_node
6377 && TREE_CODE (rhs) == MODIFY_EXPR
6378 && !TREE_NO_WARNING (rhs)
6379 && TREE_TYPE (rhs) != boolean_type_node)
6381 warning (OPT_Wparentheses,
6382 "suggest parentheses around assignment used as truth value");
6383 TREE_NO_WARNING (rhs) = 1;
6386 return perform_implicit_conversion (strip_top_quals (type), rhs);
6389 /* Convert RHS to be of type TYPE.
6390 If EXP is nonzero, it is the target of the initialization.
6391 ERRTYPE is a string to use in error messages.
6393 Two major differences between the behavior of
6394 `convert_for_assignment' and `convert_for_initialization'
6395 are that references are bashed in the former, while
6396 copied in the latter, and aggregates are assigned in
6397 the former (operator=) while initialized in the
6400 If using constructor make sure no conversion operator exists, if one does
6401 exist, an ambiguity exists.
6403 If flags doesn't include LOOKUP_COMPLAIN, don't complain about anything. */
6406 convert_for_initialization (tree exp, tree type, tree rhs, int flags,
6407 const char *errtype, tree fndecl, int parmnum)
6409 enum tree_code codel = TREE_CODE (type);
6411 enum tree_code coder;
6413 /* build_c_cast puts on a NOP_EXPR to make the result not an lvalue.
6414 Strip such NOP_EXPRs, since RHS is used in non-lvalue context. */
6415 if (TREE_CODE (rhs) == NOP_EXPR
6416 && TREE_TYPE (rhs) == TREE_TYPE (TREE_OPERAND (rhs, 0))
6417 && codel != REFERENCE_TYPE)
6418 rhs = TREE_OPERAND (rhs, 0);
6420 if (type == error_mark_node
6421 || rhs == error_mark_node
6422 || (TREE_CODE (rhs) == TREE_LIST && TREE_VALUE (rhs) == error_mark_node))
6423 return error_mark_node;
6425 if ((TREE_CODE (TREE_TYPE (rhs)) == ARRAY_TYPE
6426 && TREE_CODE (type) != ARRAY_TYPE
6427 && (TREE_CODE (type) != REFERENCE_TYPE
6428 || TREE_CODE (TREE_TYPE (type)) != ARRAY_TYPE))
6429 || (TREE_CODE (TREE_TYPE (rhs)) == FUNCTION_TYPE
6430 && (TREE_CODE (type) != REFERENCE_TYPE
6431 || TREE_CODE (TREE_TYPE (type)) != FUNCTION_TYPE))
6432 || TREE_CODE (TREE_TYPE (rhs)) == METHOD_TYPE)
6433 rhs = decay_conversion (rhs);
6435 rhstype = TREE_TYPE (rhs);
6436 coder = TREE_CODE (rhstype);
6438 if (coder == ERROR_MARK)
6439 return error_mark_node;
6441 /* We accept references to incomplete types, so we can
6442 return here before checking if RHS is of complete type. */
6444 if (codel == REFERENCE_TYPE)
6446 /* This should eventually happen in convert_arguments. */
6447 int savew = 0, savee = 0;
6450 savew = warningcount, savee = errorcount;
6451 rhs = initialize_reference (type, rhs, /*decl=*/NULL_TREE,
6455 if (warningcount > savew)
6456 warning (0, "in passing argument %P of %q+D", parmnum, fndecl);
6457 else if (errorcount > savee)
6458 error ("in passing argument %P of %q+D", parmnum, fndecl);
6464 exp = require_complete_type (exp);
6465 if (exp == error_mark_node)
6466 return error_mark_node;
6468 rhstype = non_reference (rhstype);
6470 type = complete_type (type);
6472 if (IS_AGGR_TYPE (type))
6473 return ocp_convert (type, rhs, CONV_IMPLICIT|CONV_FORCE_TEMP, flags);
6475 return convert_for_assignment (type, rhs, errtype, fndecl, parmnum);
6478 /* If RETVAL is the address of, or a reference to, a local variable or
6479 temporary give an appropriate warning. */
6482 maybe_warn_about_returning_address_of_local (tree retval)
6484 tree valtype = TREE_TYPE (DECL_RESULT (current_function_decl));
6485 tree whats_returned = retval;
6489 if (TREE_CODE (whats_returned) == COMPOUND_EXPR)
6490 whats_returned = TREE_OPERAND (whats_returned, 1);
6491 else if (TREE_CODE (whats_returned) == CONVERT_EXPR
6492 || TREE_CODE (whats_returned) == NON_LVALUE_EXPR
6493 || TREE_CODE (whats_returned) == NOP_EXPR)
6494 whats_returned = TREE_OPERAND (whats_returned, 0);
6499 if (TREE_CODE (whats_returned) != ADDR_EXPR)
6501 whats_returned = TREE_OPERAND (whats_returned, 0);
6503 if (TREE_CODE (valtype) == REFERENCE_TYPE)
6505 if (TREE_CODE (whats_returned) == AGGR_INIT_EXPR
6506 || TREE_CODE (whats_returned) == TARGET_EXPR)
6508 warning (0, "returning reference to temporary");
6511 if (TREE_CODE (whats_returned) == VAR_DECL
6512 && DECL_NAME (whats_returned)
6513 && TEMP_NAME_P (DECL_NAME (whats_returned)))
6515 warning (0, "reference to non-lvalue returned");
6520 while (TREE_CODE (whats_returned) == COMPONENT_REF
6521 || TREE_CODE (whats_returned) == ARRAY_REF)
6522 whats_returned = TREE_OPERAND (whats_returned, 0);
6524 if (DECL_P (whats_returned)
6525 && DECL_NAME (whats_returned)
6526 && DECL_FUNCTION_SCOPE_P (whats_returned)
6527 && !(TREE_STATIC (whats_returned)
6528 || TREE_PUBLIC (whats_returned)))
6530 if (TREE_CODE (valtype) == REFERENCE_TYPE)
6531 warning (0, "reference to local variable %q+D returned",
6534 warning (0, "address of local variable %q+D returned",
6540 /* Check that returning RETVAL from the current function is valid.
6541 Return an expression explicitly showing all conversions required to
6542 change RETVAL into the function return type, and to assign it to
6543 the DECL_RESULT for the function. Set *NO_WARNING to true if
6544 code reaches end of non-void function warning shouldn't be issued
6545 on this RETURN_EXPR. */
6548 check_return_expr (tree retval, bool *no_warning)
6551 /* The type actually returned by the function, after any
6554 int fn_returns_value_p;
6556 *no_warning = false;
6558 /* A `volatile' function is one that isn't supposed to return, ever.
6559 (This is a G++ extension, used to get better code for functions
6560 that call the `volatile' function.) */
6561 if (TREE_THIS_VOLATILE (current_function_decl))
6562 warning (0, "function declared %<noreturn%> has a %<return%> statement");
6564 /* Check for various simple errors. */
6565 if (DECL_DESTRUCTOR_P (current_function_decl))
6568 error ("returning a value from a destructor");
6571 else if (DECL_CONSTRUCTOR_P (current_function_decl))
6573 if (in_function_try_handler)
6574 /* If a return statement appears in a handler of the
6575 function-try-block of a constructor, the program is ill-formed. */
6576 error ("cannot return from a handler of a function-try-block of a constructor");
6578 /* You can't return a value from a constructor. */
6579 error ("returning a value from a constructor");
6583 if (processing_template_decl)
6585 current_function_returns_value = 1;
6586 check_for_bare_parameter_packs (retval);
6590 /* When no explicit return-value is given in a function with a named
6591 return value, the named return value is used. */
6592 result = DECL_RESULT (current_function_decl);
6593 valtype = TREE_TYPE (result);
6594 gcc_assert (valtype != NULL_TREE);
6595 fn_returns_value_p = !VOID_TYPE_P (valtype);
6596 if (!retval && DECL_NAME (result) && fn_returns_value_p)
6599 /* Check for a return statement with no return value in a function
6600 that's supposed to return a value. */
6601 if (!retval && fn_returns_value_p)
6603 pedwarn ("return-statement with no value, in function returning %qT",
6605 /* Clear this, so finish_function won't say that we reach the
6606 end of a non-void function (which we don't, we gave a
6608 current_function_returns_null = 0;
6609 /* And signal caller that TREE_NO_WARNING should be set on the
6610 RETURN_EXPR to avoid control reaches end of non-void function
6611 warnings in tree-cfg.c. */
6614 /* Check for a return statement with a value in a function that
6615 isn't supposed to return a value. */
6616 else if (retval && !fn_returns_value_p)
6618 if (VOID_TYPE_P (TREE_TYPE (retval)))
6619 /* You can return a `void' value from a function of `void'
6620 type. In that case, we have to evaluate the expression for
6621 its side-effects. */
6622 finish_expr_stmt (retval);
6624 pedwarn ("return-statement with a value, in function "
6625 "returning 'void'");
6627 current_function_returns_null = 1;
6629 /* There's really no value to return, after all. */
6633 /* Remember that this function can sometimes return without a
6635 current_function_returns_null = 1;
6637 /* Remember that this function did return a value. */
6638 current_function_returns_value = 1;
6640 /* Check for erroneous operands -- but after giving ourselves a
6641 chance to provide an error about returning a value from a void
6643 if (error_operand_p (retval))
6645 current_function_return_value = error_mark_node;
6646 return error_mark_node;
6649 /* Only operator new(...) throw(), can return NULL [expr.new/13]. */
6650 if ((DECL_OVERLOADED_OPERATOR_P (current_function_decl) == NEW_EXPR
6651 || DECL_OVERLOADED_OPERATOR_P (current_function_decl) == VEC_NEW_EXPR)
6652 && !TYPE_NOTHROW_P (TREE_TYPE (current_function_decl))
6654 && null_ptr_cst_p (retval))
6655 warning (0, "%<operator new%> must not return NULL unless it is "
6656 "declared %<throw()%> (or -fcheck-new is in effect)");
6658 /* Effective C++ rule 15. See also start_function. */
6660 && DECL_NAME (current_function_decl) == ansi_assopname(NOP_EXPR))
6664 /* The function return type must be a reference to the current
6666 if (TREE_CODE (valtype) == REFERENCE_TYPE
6667 && same_type_ignoring_top_level_qualifiers_p
6668 (TREE_TYPE (valtype), TREE_TYPE (current_class_ref)))
6670 /* Returning '*this' is obviously OK. */
6671 if (retval == current_class_ref)
6673 /* If we are calling a function whose return type is the same of
6674 the current class reference, it is ok. */
6675 else if (TREE_CODE (retval) == INDIRECT_REF
6676 && TREE_CODE (TREE_OPERAND (retval, 0)) == CALL_EXPR)
6681 warning (OPT_Weffc__, "%<operator=%> should return a reference to %<*this%>");
6684 /* The fabled Named Return Value optimization, as per [class.copy]/15:
6686 [...] For a function with a class return type, if the expression
6687 in the return statement is the name of a local object, and the cv-
6688 unqualified type of the local object is the same as the function
6689 return type, an implementation is permitted to omit creating the tem-
6690 porary object to hold the function return value [...]
6692 So, if this is a value-returning function that always returns the same
6693 local variable, remember it.
6695 It might be nice to be more flexible, and choose the first suitable
6696 variable even if the function sometimes returns something else, but
6697 then we run the risk of clobbering the variable we chose if the other
6698 returned expression uses the chosen variable somehow. And people expect
6699 this restriction, anyway. (jason 2000-11-19)
6701 See finish_function and finalize_nrv for the rest of this optimization. */
6703 if (fn_returns_value_p && flag_elide_constructors)
6705 if (retval != NULL_TREE
6706 && (current_function_return_value == NULL_TREE
6707 || current_function_return_value == retval)
6708 && TREE_CODE (retval) == VAR_DECL
6709 && DECL_CONTEXT (retval) == current_function_decl
6710 && ! TREE_STATIC (retval)
6711 && (DECL_ALIGN (retval)
6712 >= DECL_ALIGN (DECL_RESULT (current_function_decl)))
6713 && same_type_p ((TYPE_MAIN_VARIANT
6714 (TREE_TYPE (retval))),
6716 (TREE_TYPE (TREE_TYPE (current_function_decl))))))
6717 current_function_return_value = retval;
6719 current_function_return_value = error_mark_node;
6722 /* We don't need to do any conversions when there's nothing being
6727 /* Do any required conversions. */
6728 if (retval == result || DECL_CONSTRUCTOR_P (current_function_decl))
6729 /* No conversions are required. */
6733 /* The type the function is declared to return. */
6734 tree functype = TREE_TYPE (TREE_TYPE (current_function_decl));
6736 /* The functype's return type will have been set to void, if it
6737 was an incomplete type. Just treat this as 'return;' */
6738 if (VOID_TYPE_P (functype))
6739 return error_mark_node;
6741 /* First convert the value to the function's return type, then
6742 to the type of return value's location to handle the
6743 case that functype is smaller than the valtype. */
6744 retval = convert_for_initialization
6745 (NULL_TREE, functype, retval, LOOKUP_NORMAL|LOOKUP_ONLYCONVERTING,
6746 "return", NULL_TREE, 0);
6747 retval = convert (valtype, retval);
6749 /* If the conversion failed, treat this just like `return;'. */
6750 if (retval == error_mark_node)
6752 /* We can't initialize a register from a AGGR_INIT_EXPR. */
6753 else if (! current_function_returns_struct
6754 && TREE_CODE (retval) == TARGET_EXPR
6755 && TREE_CODE (TREE_OPERAND (retval, 1)) == AGGR_INIT_EXPR)
6756 retval = build2 (COMPOUND_EXPR, TREE_TYPE (retval), retval,
6757 TREE_OPERAND (retval, 0));
6759 maybe_warn_about_returning_address_of_local (retval);
6762 /* Actually copy the value returned into the appropriate location. */
6763 if (retval && retval != result)
6764 retval = build2 (INIT_EXPR, TREE_TYPE (result), result, retval);
6770 /* Returns nonzero if the pointer-type FROM can be converted to the
6771 pointer-type TO via a qualification conversion. If CONSTP is -1,
6772 then we return nonzero if the pointers are similar, and the
6773 cv-qualification signature of FROM is a proper subset of that of TO.
6775 If CONSTP is positive, then all outer pointers have been
6779 comp_ptr_ttypes_real (tree to, tree from, int constp)
6781 bool to_more_cv_qualified = false;
6783 for (; ; to = TREE_TYPE (to), from = TREE_TYPE (from))
6785 if (TREE_CODE (to) != TREE_CODE (from))
6788 if (TREE_CODE (from) == OFFSET_TYPE
6789 && !same_type_p (TYPE_OFFSET_BASETYPE (from),
6790 TYPE_OFFSET_BASETYPE (to)))
6793 /* Const and volatile mean something different for function types,
6794 so the usual checks are not appropriate. */
6795 if (TREE_CODE (to) != FUNCTION_TYPE && TREE_CODE (to) != METHOD_TYPE)
6797 /* In Objective-C++, some types may have been 'volatilized' by
6798 the compiler for EH; when comparing them here, the volatile
6799 qualification must be ignored. */
6800 bool objc_quals_match = objc_type_quals_match (to, from);
6802 if (!at_least_as_qualified_p (to, from) && !objc_quals_match)
6805 if (!at_least_as_qualified_p (from, to) && !objc_quals_match)
6809 to_more_cv_qualified = true;
6813 constp &= TYPE_READONLY (to);
6816 if (TREE_CODE (to) != POINTER_TYPE && !TYPE_PTRMEM_P (to))
6817 return ((constp >= 0 || to_more_cv_qualified)
6818 && same_type_ignoring_top_level_qualifiers_p (to, from));
6822 /* When comparing, say, char ** to char const **, this function takes
6823 the 'char *' and 'char const *'. Do not pass non-pointer/reference
6824 types to this function. */
6827 comp_ptr_ttypes (tree to, tree from)
6829 return comp_ptr_ttypes_real (to, from, 1);
6832 /* Returns 1 if to and from are (possibly multi-level) pointers to the same
6833 type or inheritance-related types, regardless of cv-quals. */
6836 ptr_reasonably_similar (tree to, tree from)
6838 for (; ; to = TREE_TYPE (to), from = TREE_TYPE (from))
6840 /* Any target type is similar enough to void. */
6841 if (TREE_CODE (to) == VOID_TYPE
6842 || TREE_CODE (from) == VOID_TYPE)
6845 if (TREE_CODE (to) != TREE_CODE (from))
6848 if (TREE_CODE (from) == OFFSET_TYPE
6849 && comptypes (TYPE_OFFSET_BASETYPE (to),
6850 TYPE_OFFSET_BASETYPE (from),
6851 COMPARE_BASE | COMPARE_DERIVED))
6854 if (TREE_CODE (to) == VECTOR_TYPE
6855 && vector_types_convertible_p (to, from, false))
6858 if (TREE_CODE (to) == INTEGER_TYPE
6859 && TYPE_PRECISION (to) == TYPE_PRECISION (from))
6862 if (TREE_CODE (to) == FUNCTION_TYPE)
6865 if (TREE_CODE (to) != POINTER_TYPE)
6867 (TYPE_MAIN_VARIANT (to), TYPE_MAIN_VARIANT (from),
6868 COMPARE_BASE | COMPARE_DERIVED);
6872 /* Return true if TO and FROM (both of which are POINTER_TYPEs or
6873 pointer-to-member types) are the same, ignoring cv-qualification at
6877 comp_ptr_ttypes_const (tree to, tree from)
6879 for (; ; to = TREE_TYPE (to), from = TREE_TYPE (from))
6881 if (TREE_CODE (to) != TREE_CODE (from))
6884 if (TREE_CODE (from) == OFFSET_TYPE
6885 && same_type_p (TYPE_OFFSET_BASETYPE (from),
6886 TYPE_OFFSET_BASETYPE (to)))
6889 if (TREE_CODE (to) != POINTER_TYPE)
6890 return same_type_ignoring_top_level_qualifiers_p (to, from);
6894 /* Returns the type qualifiers for this type, including the qualifiers on the
6895 elements for an array type. */
6898 cp_type_quals (tree type)
6900 type = strip_array_types (type);
6901 if (type == error_mark_node)
6902 return TYPE_UNQUALIFIED;
6903 return TYPE_QUALS (type);
6906 /* Returns nonzero if the TYPE is const from a C++ perspective: look inside
6910 cp_type_readonly (tree type)
6912 type = strip_array_types (type);
6913 return TYPE_READONLY (type);
6916 /* Returns nonzero if the TYPE contains a mutable member. */
6919 cp_has_mutable_p (tree type)
6921 type = strip_array_types (type);
6923 return CLASS_TYPE_P (type) && CLASSTYPE_HAS_MUTABLE (type);
6926 /* Apply the TYPE_QUALS to the new DECL. */
6928 cp_apply_type_quals_to_decl (int type_quals, tree decl)
6930 tree type = TREE_TYPE (decl);
6932 if (type == error_mark_node)
6935 if (TREE_CODE (type) == FUNCTION_TYPE
6936 && type_quals != TYPE_UNQUALIFIED)
6938 /* This was an error in C++98 (cv-qualifiers cannot be added to
6939 a function type), but DR 295 makes the code well-formed by
6940 dropping the extra qualifiers. */
6943 tree bad_type = build_qualified_type (type, type_quals);
6944 pedwarn ("ignoring %qV qualifiers added to function type %qT",
6948 TREE_TYPE (decl) = TYPE_MAIN_VARIANT (type);
6952 /* Avoid setting TREE_READONLY incorrectly. */
6953 if (/* If the object has a constructor, the constructor may modify
6955 TYPE_NEEDS_CONSTRUCTING (type)
6956 /* If the type isn't complete, we don't know yet if it will need
6958 || !COMPLETE_TYPE_P (type)
6959 /* If the type has a mutable component, that component might be
6961 || TYPE_HAS_MUTABLE_P (type))
6962 type_quals &= ~TYPE_QUAL_CONST;
6964 c_apply_type_quals_to_decl (type_quals, decl);
6967 /* Subroutine of casts_away_constness. Make T1 and T2 point at
6968 exemplar types such that casting T1 to T2 is casting away constness
6969 if and only if there is no implicit conversion from T1 to T2. */
6972 casts_away_constness_r (tree *t1, tree *t2)
6977 /* [expr.const.cast]
6979 For multi-level pointer to members and multi-level mixed pointers
6980 and pointers to members (conv.qual), the "member" aspect of a
6981 pointer to member level is ignored when determining if a const
6982 cv-qualifier has been cast away. */
6983 /* [expr.const.cast]
6985 For two pointer types:
6987 X1 is T1cv1,1 * ... cv1,N * where T1 is not a pointer type
6988 X2 is T2cv2,1 * ... cv2,M * where T2 is not a pointer type
6991 casting from X1 to X2 casts away constness if, for a non-pointer
6992 type T there does not exist an implicit conversion (clause
6995 Tcv1,(N-K+1) * cv1,(N-K+2) * ... cv1,N *
6999 Tcv2,(M-K+1) * cv2,(M-K+2) * ... cv2,M *. */
7000 if ((!TYPE_PTR_P (*t1) && !TYPE_PTRMEM_P (*t1))
7001 || (!TYPE_PTR_P (*t2) && !TYPE_PTRMEM_P (*t2)))
7003 *t1 = cp_build_qualified_type (void_type_node,
7004 cp_type_quals (*t1));
7005 *t2 = cp_build_qualified_type (void_type_node,
7006 cp_type_quals (*t2));
7010 quals1 = cp_type_quals (*t1);
7011 quals2 = cp_type_quals (*t2);
7013 if (TYPE_PTRMEM_P (*t1))
7014 *t1 = TYPE_PTRMEM_POINTED_TO_TYPE (*t1);
7016 *t1 = TREE_TYPE (*t1);
7017 if (TYPE_PTRMEM_P (*t2))
7018 *t2 = TYPE_PTRMEM_POINTED_TO_TYPE (*t2);
7020 *t2 = TREE_TYPE (*t2);
7022 casts_away_constness_r (t1, t2);
7023 *t1 = build_pointer_type (*t1);
7024 *t2 = build_pointer_type (*t2);
7025 *t1 = cp_build_qualified_type (*t1, quals1);
7026 *t2 = cp_build_qualified_type (*t2, quals2);
7029 /* Returns nonzero if casting from TYPE1 to TYPE2 casts away
7033 casts_away_constness (tree t1, tree t2)
7035 if (TREE_CODE (t2) == REFERENCE_TYPE)
7037 /* [expr.const.cast]
7039 Casting from an lvalue of type T1 to an lvalue of type T2
7040 using a reference cast casts away constness if a cast from an
7041 rvalue of type "pointer to T1" to the type "pointer to T2"
7042 casts away constness. */
7043 t1 = (TREE_CODE (t1) == REFERENCE_TYPE ? TREE_TYPE (t1) : t1);
7044 return casts_away_constness (build_pointer_type (t1),
7045 build_pointer_type (TREE_TYPE (t2)));
7048 if (TYPE_PTRMEM_P (t1) && TYPE_PTRMEM_P (t2))
7049 /* [expr.const.cast]
7051 Casting from an rvalue of type "pointer to data member of X
7052 of type T1" to the type "pointer to data member of Y of type
7053 T2" casts away constness if a cast from an rvalue of type
7054 "pointer to T1" to the type "pointer to T2" casts away
7056 return casts_away_constness
7057 (build_pointer_type (TYPE_PTRMEM_POINTED_TO_TYPE (t1)),
7058 build_pointer_type (TYPE_PTRMEM_POINTED_TO_TYPE (t2)));
7060 /* Casting away constness is only something that makes sense for
7061 pointer or reference types. */
7062 if (TREE_CODE (t1) != POINTER_TYPE
7063 || TREE_CODE (t2) != POINTER_TYPE)
7066 /* Top-level qualifiers don't matter. */
7067 t1 = TYPE_MAIN_VARIANT (t1);
7068 t2 = TYPE_MAIN_VARIANT (t2);
7069 casts_away_constness_r (&t1, &t2);
7070 if (!can_convert (t2, t1))
7076 /* If T is a REFERENCE_TYPE return the type to which T refers.
7077 Otherwise, return T itself. */
7080 non_reference (tree t)
7082 if (TREE_CODE (t) == REFERENCE_TYPE)
7088 /* Return nonzero if REF is an lvalue valid for this language;
7089 otherwise, print an error message and return zero. USE says
7090 how the lvalue is being used and so selects the error message. */
7093 lvalue_or_else (tree ref, enum lvalue_use use)
7095 int win = lvalue_p (ref);