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))
996 if (!comp_template_parms
997 (DECL_TEMPLATE_PARMS (TEMPLATE_TEMPLATE_PARM_TEMPLATE_DECL (t1)),
998 DECL_TEMPLATE_PARMS (TEMPLATE_TEMPLATE_PARM_TEMPLATE_DECL (t2))))
1000 if (TREE_CODE (t1) == TEMPLATE_TEMPLATE_PARM)
1002 /* Don't check inheritance. */
1003 strict = COMPARE_STRICT;
1008 if (TYPE_TEMPLATE_INFO (t1) && TYPE_TEMPLATE_INFO (t2)
1009 && (TYPE_TI_TEMPLATE (t1) == TYPE_TI_TEMPLATE (t2)
1010 || TREE_CODE (t1) == BOUND_TEMPLATE_TEMPLATE_PARM)
1011 && comp_template_args (TYPE_TI_ARGS (t1), TYPE_TI_ARGS (t2)))
1014 if ((strict & COMPARE_BASE) && DERIVED_FROM_P (t1, t2))
1016 else if ((strict & COMPARE_DERIVED) && DERIVED_FROM_P (t2, t1))
1022 if (!comptypes (TYPE_OFFSET_BASETYPE (t1), TYPE_OFFSET_BASETYPE (t2),
1023 strict & ~COMPARE_REDECLARATION))
1025 if (!same_type_p (TREE_TYPE (t1), TREE_TYPE (t2)))
1030 case REFERENCE_TYPE:
1031 if (TYPE_MODE (t1) != TYPE_MODE (t2)
1032 || TYPE_REF_CAN_ALIAS_ALL (t1) != TYPE_REF_CAN_ALIAS_ALL (t2)
1033 || !same_type_p (TREE_TYPE (t1), TREE_TYPE (t2)))
1039 if (!same_type_p (TREE_TYPE (t1), TREE_TYPE (t2)))
1041 if (!compparms (TYPE_ARG_TYPES (t1), TYPE_ARG_TYPES (t2)))
1046 /* Target types must match incl. qualifiers. */
1047 if (!comp_array_types (t1, t2, !!(strict & COMPARE_REDECLARATION)))
1051 case TEMPLATE_TYPE_PARM:
1052 if (TEMPLATE_TYPE_IDX (t1) != TEMPLATE_TYPE_IDX (t2)
1053 || TEMPLATE_TYPE_LEVEL (t1) != TEMPLATE_TYPE_LEVEL (t2))
1058 if (!cp_tree_equal (TYPENAME_TYPE_FULLNAME (t1),
1059 TYPENAME_TYPE_FULLNAME (t2)))
1061 if (!same_type_p (TYPE_CONTEXT (t1), TYPE_CONTEXT (t2)))
1065 case UNBOUND_CLASS_TEMPLATE:
1066 if (!cp_tree_equal (TYPE_IDENTIFIER (t1), TYPE_IDENTIFIER (t2)))
1068 if (!same_type_p (TYPE_CONTEXT (t1), TYPE_CONTEXT (t2)))
1073 if (!same_type_p (TREE_TYPE (t1), TREE_TYPE (t2)))
1078 if (TYPE_VECTOR_SUBPARTS (t1) != TYPE_VECTOR_SUBPARTS (t2)
1079 || !same_type_p (TREE_TYPE (t1), TREE_TYPE (t2)))
1087 /* If we get here, we know that from a target independent POV the
1088 types are the same. Make sure the target attributes are also
1090 return targetm.comp_type_attributes (t1, t2);
1093 /* Return true if T1 and T2 are related as allowed by STRICT. STRICT
1094 is a bitwise-or of the COMPARE_* flags. */
1097 comptypes (tree t1, tree t2, int strict)
1099 if (strict == COMPARE_STRICT)
1106 if (t1 == error_mark_node || t2 == error_mark_node)
1109 if (TYPE_STRUCTURAL_EQUALITY_P (t1) || TYPE_STRUCTURAL_EQUALITY_P (t2))
1110 /* At least one of the types requires structural equality, so
1111 perform a deep check. */
1112 return structural_comptypes (t1, t2, strict);
1114 if (VERIFY_CANONICAL_TYPES)
1116 result = structural_comptypes (t1, t2, strict);
1118 if (result && TYPE_CANONICAL (t1) != TYPE_CANONICAL (t2))
1120 /* The two types are structurally equivalent, but their
1121 canonical types were different. This is a failure of the
1122 canonical type propagation code.*/
1124 "canonical types differ for identical types %T and %T",
1129 else if (!result && TYPE_CANONICAL (t1) == TYPE_CANONICAL (t2))
1131 /* Two types are structurally different, but the canonical
1132 types are the same. This means we were over-eager in
1133 assigning canonical types. */
1135 "same canonical type node for different types %T and %T",
1144 return TYPE_CANONICAL (t1) == TYPE_CANONICAL (t2);
1146 else if (strict == COMPARE_STRUCTURAL)
1147 return structural_comptypes (t1, t2, COMPARE_STRICT);
1149 return structural_comptypes (t1, t2, strict);
1152 /* Returns 1 if TYPE1 is at least as qualified as TYPE2. */
1155 at_least_as_qualified_p (tree type1, tree type2)
1157 int q1 = cp_type_quals (type1);
1158 int q2 = cp_type_quals (type2);
1160 /* All qualifiers for TYPE2 must also appear in TYPE1. */
1161 return (q1 & q2) == q2;
1164 /* Returns 1 if TYPE1 is more cv-qualified than TYPE2, -1 if TYPE2 is
1165 more cv-qualified that TYPE1, and 0 otherwise. */
1168 comp_cv_qualification (tree type1, tree type2)
1170 int q1 = cp_type_quals (type1);
1171 int q2 = cp_type_quals (type2);
1176 if ((q1 & q2) == q2)
1178 else if ((q1 & q2) == q1)
1184 /* Returns 1 if the cv-qualification signature of TYPE1 is a proper
1185 subset of the cv-qualification signature of TYPE2, and the types
1186 are similar. Returns -1 if the other way 'round, and 0 otherwise. */
1189 comp_cv_qual_signature (tree type1, tree type2)
1191 if (comp_ptr_ttypes_real (type2, type1, -1))
1193 else if (comp_ptr_ttypes_real (type1, type2, -1))
1199 /* Subroutines of `comptypes'. */
1201 /* Return true if two parameter type lists PARMS1 and PARMS2 are
1202 equivalent in the sense that functions with those parameter types
1203 can have equivalent types. The two lists must be equivalent,
1204 element by element. */
1207 compparms (tree parms1, tree parms2)
1211 /* An unspecified parmlist matches any specified parmlist
1212 whose argument types don't need default promotions. */
1214 for (t1 = parms1, t2 = parms2;
1216 t1 = TREE_CHAIN (t1), t2 = TREE_CHAIN (t2))
1218 /* If one parmlist is shorter than the other,
1219 they fail to match. */
1222 if (!same_type_p (TREE_VALUE (t1), TREE_VALUE (t2)))
1229 /* Process a sizeof or alignof expression where the operand is a
1233 cxx_sizeof_or_alignof_type (tree type, enum tree_code op, bool complain)
1238 gcc_assert (op == SIZEOF_EXPR || op == ALIGNOF_EXPR);
1239 if (type == error_mark_node)
1240 return error_mark_node;
1242 type = non_reference (type);
1243 if (TREE_CODE (type) == METHOD_TYPE)
1245 if (complain && (pedantic || warn_pointer_arith))
1246 pedwarn ("invalid application of %qs to a member function",
1247 operator_name_info[(int) op].name);
1248 value = size_one_node;
1251 dependent_p = dependent_type_p (type);
1253 complete_type (type);
1255 /* VLA types will have a non-constant size. In the body of an
1256 uninstantiated template, we don't need to try to compute the
1257 value, because the sizeof expression is not an integral
1258 constant expression in that case. And, if we do try to
1259 compute the value, we'll likely end up with SAVE_EXPRs, which
1260 the template substitution machinery does not expect to see. */
1261 || (processing_template_decl
1262 && COMPLETE_TYPE_P (type)
1263 && TREE_CODE (TYPE_SIZE (type)) != INTEGER_CST))
1265 value = build_min (op, size_type_node, type);
1266 TREE_READONLY (value) = 1;
1270 return c_sizeof_or_alignof_type (complete_type (type),
1275 /* Process a sizeof expression where the operand is an expression. */
1278 cxx_sizeof_expr (tree e)
1280 if (e == error_mark_node)
1281 return error_mark_node;
1283 if (processing_template_decl)
1285 e = build_min (SIZEOF_EXPR, size_type_node, e);
1286 TREE_SIDE_EFFECTS (e) = 0;
1287 TREE_READONLY (e) = 1;
1292 if (TREE_CODE (e) == COMPONENT_REF
1293 && TREE_CODE (TREE_OPERAND (e, 1)) == FIELD_DECL
1294 && DECL_C_BIT_FIELD (TREE_OPERAND (e, 1)))
1296 error ("invalid application of %<sizeof%> to a bit-field");
1299 else if (is_overloaded_fn (e))
1301 pedwarn ("ISO C++ forbids applying %<sizeof%> to an expression of "
1305 else if (type_unknown_p (e))
1307 cxx_incomplete_type_error (e, TREE_TYPE (e));
1313 return cxx_sizeof_or_alignof_type (e, SIZEOF_EXPR, true);
1316 /* Implement the __alignof keyword: Return the minimum required
1317 alignment of E, measured in bytes. For VAR_DECL's and
1318 FIELD_DECL's return DECL_ALIGN (which can be set from an
1319 "aligned" __attribute__ specification). */
1322 cxx_alignof_expr (tree e)
1326 if (e == error_mark_node)
1327 return error_mark_node;
1329 if (processing_template_decl)
1331 e = build_min (ALIGNOF_EXPR, size_type_node, e);
1332 TREE_SIDE_EFFECTS (e) = 0;
1333 TREE_READONLY (e) = 1;
1338 if (TREE_CODE (e) == VAR_DECL)
1339 t = size_int (DECL_ALIGN_UNIT (e));
1340 else if (TREE_CODE (e) == COMPONENT_REF
1341 && TREE_CODE (TREE_OPERAND (e, 1)) == FIELD_DECL
1342 && DECL_C_BIT_FIELD (TREE_OPERAND (e, 1)))
1344 error ("invalid application of %<__alignof%> to a bit-field");
1347 else if (TREE_CODE (e) == COMPONENT_REF
1348 && TREE_CODE (TREE_OPERAND (e, 1)) == FIELD_DECL)
1349 t = size_int (DECL_ALIGN_UNIT (TREE_OPERAND (e, 1)));
1350 else if (is_overloaded_fn (e))
1352 pedwarn ("ISO C++ forbids applying %<__alignof%> to an expression of "
1356 else if (type_unknown_p (e))
1358 cxx_incomplete_type_error (e, TREE_TYPE (e));
1362 return cxx_sizeof_or_alignof_type (TREE_TYPE (e), ALIGNOF_EXPR, true);
1364 return fold_convert (size_type_node, t);
1367 /* Process a sizeof or alignof expression E with code OP where the operand
1368 is an expression. */
1371 cxx_sizeof_or_alignof_expr (tree e, enum tree_code op)
1373 if (op == SIZEOF_EXPR)
1374 return cxx_sizeof_expr (e);
1376 return cxx_alignof_expr (e);
1379 /* EXPR is being used in a context that is not a function call.
1384 The expression can be used only as the left-hand operand of a
1385 member function call.
1387 [expr.mptr.operator]
1389 If the result of .* or ->* is a function, then that result can be
1390 used only as the operand for the function call operator ().
1392 by issuing an error message if appropriate. Returns true iff EXPR
1393 violates these rules. */
1396 invalid_nonstatic_memfn_p (tree expr)
1398 if (TREE_CODE (TREE_TYPE (expr)) == METHOD_TYPE)
1400 error ("invalid use of non-static member function");
1406 /* If EXP is a reference to a bitfield, and the type of EXP does not
1407 match the declared type of the bitfield, return the declared type
1408 of the bitfield. Otherwise, return NULL_TREE. */
1411 is_bitfield_expr_with_lowered_type (tree exp)
1415 if (TREE_CODE (exp) == COND_EXPR)
1417 if (!is_bitfield_expr_with_lowered_type (TREE_OPERAND (exp, 1)))
1419 return is_bitfield_expr_with_lowered_type (TREE_OPERAND (exp, 2));
1421 if (TREE_CODE (exp) != COMPONENT_REF)
1423 field = TREE_OPERAND (exp, 1);
1424 if (TREE_CODE (field) != FIELD_DECL || !DECL_C_BIT_FIELD (field))
1426 if (same_type_ignoring_top_level_qualifiers_p
1427 (TREE_TYPE (exp), DECL_BIT_FIELD_TYPE (field)))
1429 return DECL_BIT_FIELD_TYPE (field);
1432 /* Perform the conversions in [expr] that apply when an lvalue appears
1433 in an rvalue context: the lvalue-to-rvalue, array-to-pointer, and
1434 function-to-pointer conversions. In addition, manifest constants
1435 are replaced by their values, and bitfield references are converted
1436 to their declared types.
1438 Although the returned value is being used as an rvalue, this
1439 function does not wrap the returned expression in a
1440 NON_LVALUE_EXPR; the caller is expected to be mindful of the fact
1441 that the return value is no longer an lvalue. */
1444 decay_conversion (tree exp)
1447 enum tree_code code;
1449 type = TREE_TYPE (exp);
1450 if (type == error_mark_node)
1451 return error_mark_node;
1453 if (type_unknown_p (exp))
1455 cxx_incomplete_type_error (exp, TREE_TYPE (exp));
1456 return error_mark_node;
1459 exp = decl_constant_value (exp);
1460 if (error_operand_p (exp))
1461 return error_mark_node;
1463 /* build_c_cast puts on a NOP_EXPR to make the result not an lvalue.
1464 Leave such NOP_EXPRs, since RHS is being used in non-lvalue context. */
1465 code = TREE_CODE (type);
1466 if (code == VOID_TYPE)
1468 error ("void value not ignored as it ought to be");
1469 return error_mark_node;
1471 if (invalid_nonstatic_memfn_p (exp))
1472 return error_mark_node;
1473 if (code == FUNCTION_TYPE || is_overloaded_fn (exp))
1474 return build_unary_op (ADDR_EXPR, exp, 0);
1475 if (code == ARRAY_TYPE)
1480 if (TREE_CODE (exp) == INDIRECT_REF)
1481 return build_nop (build_pointer_type (TREE_TYPE (type)),
1482 TREE_OPERAND (exp, 0));
1484 if (TREE_CODE (exp) == COMPOUND_EXPR)
1486 tree op1 = decay_conversion (TREE_OPERAND (exp, 1));
1487 return build2 (COMPOUND_EXPR, TREE_TYPE (op1),
1488 TREE_OPERAND (exp, 0), op1);
1492 && ! (TREE_CODE (exp) == CONSTRUCTOR && TREE_STATIC (exp)))
1494 error ("invalid use of non-lvalue array");
1495 return error_mark_node;
1498 ptrtype = build_pointer_type (TREE_TYPE (type));
1500 if (TREE_CODE (exp) == VAR_DECL)
1502 if (!cxx_mark_addressable (exp))
1503 return error_mark_node;
1504 adr = build_nop (ptrtype, build_address (exp));
1507 /* This way is better for a COMPONENT_REF since it can
1508 simplify the offset for a component. */
1509 adr = build_unary_op (ADDR_EXPR, exp, 1);
1510 return cp_convert (ptrtype, adr);
1513 /* If a bitfield is used in a context where integral promotion
1514 applies, then the caller is expected to have used
1515 default_conversion. That function promotes bitfields correctly
1516 before calling this function. At this point, if we have a
1517 bitfield referenced, we may assume that is not subject to
1518 promotion, and that, therefore, the type of the resulting rvalue
1519 is the declared type of the bitfield. */
1520 exp = convert_bitfield_to_declared_type (exp);
1522 /* We do not call rvalue() here because we do not want to wrap EXP
1523 in a NON_LVALUE_EXPR. */
1527 Non-class rvalues always have cv-unqualified types. */
1528 type = TREE_TYPE (exp);
1529 if (!CLASS_TYPE_P (type) && cp_type_quals (type))
1530 exp = build_nop (TYPE_MAIN_VARIANT (type), exp);
1535 /* Perform prepatory conversions, as part of the "usual arithmetic
1536 conversions". In particular, as per [expr]:
1538 Whenever an lvalue expression appears as an operand of an
1539 operator that expects the rvalue for that operand, the
1540 lvalue-to-rvalue, array-to-pointer, or function-to-pointer
1541 standard conversions are applied to convert the expression to an
1544 In addition, we perform integral promotions here, as those are
1545 applied to both operands to a binary operator before determining
1546 what additional conversions should apply. */
1549 default_conversion (tree exp)
1551 /* Perform the integral promotions first so that bitfield
1552 expressions (which may promote to "int", even if the bitfield is
1553 declared "unsigned") are promoted correctly. */
1554 if (INTEGRAL_OR_ENUMERATION_TYPE_P (TREE_TYPE (exp)))
1555 exp = perform_integral_promotions (exp);
1556 /* Perform the other conversions. */
1557 exp = decay_conversion (exp);
1562 /* EXPR is an expression with an integral or enumeration type.
1563 Perform the integral promotions in [conv.prom], and return the
1567 perform_integral_promotions (tree expr)
1574 If the bitfield has an enumerated type, it is treated as any
1575 other value of that type for promotion purposes. */
1576 type = is_bitfield_expr_with_lowered_type (expr);
1577 if (!type || TREE_CODE (type) != ENUMERAL_TYPE)
1578 type = TREE_TYPE (expr);
1579 gcc_assert (INTEGRAL_OR_ENUMERATION_TYPE_P (type));
1580 promoted_type = type_promotes_to (type);
1581 if (type != promoted_type)
1582 expr = cp_convert (promoted_type, expr);
1586 /* Take the address of an inline function without setting TREE_ADDRESSABLE
1590 inline_conversion (tree exp)
1592 if (TREE_CODE (exp) == FUNCTION_DECL)
1593 exp = build1 (ADDR_EXPR, build_pointer_type (TREE_TYPE (exp)), exp);
1598 /* Returns nonzero iff exp is a STRING_CST or the result of applying
1599 decay_conversion to one. */
1602 string_conv_p (tree totype, tree exp, int warn)
1606 if (TREE_CODE (totype) != POINTER_TYPE)
1609 t = TREE_TYPE (totype);
1610 if (!same_type_p (t, char_type_node)
1611 && !same_type_p (t, wchar_type_node))
1614 if (TREE_CODE (exp) == STRING_CST)
1616 /* Make sure that we don't try to convert between char and wchar_t. */
1617 if (!same_type_p (TYPE_MAIN_VARIANT (TREE_TYPE (TREE_TYPE (exp))), t))
1622 /* Is this a string constant which has decayed to 'const char *'? */
1623 t = build_pointer_type (build_qualified_type (t, TYPE_QUAL_CONST));
1624 if (!same_type_p (TREE_TYPE (exp), t))
1627 if (TREE_CODE (exp) != ADDR_EXPR
1628 || TREE_CODE (TREE_OPERAND (exp, 0)) != STRING_CST)
1632 /* This warning is not very useful, as it complains about printf. */
1634 warning (OPT_Wwrite_strings,
1635 "deprecated conversion from string constant to %qT",
1641 /* Given a COND_EXPR, MIN_EXPR, or MAX_EXPR in T, return it in a form that we
1642 can, for example, use as an lvalue. This code used to be in
1643 unary_complex_lvalue, but we needed it to deal with `a = (d == c) ? b : c'
1644 expressions, where we're dealing with aggregates. But now it's again only
1645 called from unary_complex_lvalue. The case (in particular) that led to
1646 this was with CODE == ADDR_EXPR, since it's not an lvalue when we'd
1650 rationalize_conditional_expr (enum tree_code code, tree t)
1652 /* For MIN_EXPR or MAX_EXPR, fold-const.c has arranged things so that
1653 the first operand is always the one to be used if both operands
1654 are equal, so we know what conditional expression this used to be. */
1655 if (TREE_CODE (t) == MIN_EXPR || TREE_CODE (t) == MAX_EXPR)
1657 tree op0 = TREE_OPERAND (t, 0);
1658 tree op1 = TREE_OPERAND (t, 1);
1660 /* The following code is incorrect if either operand side-effects. */
1661 gcc_assert (!TREE_SIDE_EFFECTS (op0)
1662 && !TREE_SIDE_EFFECTS (op1));
1664 build_conditional_expr (build_x_binary_op ((TREE_CODE (t) == MIN_EXPR
1665 ? LE_EXPR : GE_EXPR),
1666 op0, TREE_CODE (op0),
1667 op1, TREE_CODE (op1),
1668 /*overloaded_p=*/NULL),
1669 build_unary_op (code, op0, 0),
1670 build_unary_op (code, op1, 0));
1674 build_conditional_expr (TREE_OPERAND (t, 0),
1675 build_unary_op (code, TREE_OPERAND (t, 1), 0),
1676 build_unary_op (code, TREE_OPERAND (t, 2), 0));
1679 /* Given the TYPE of an anonymous union field inside T, return the
1680 FIELD_DECL for the field. If not found return NULL_TREE. Because
1681 anonymous unions can nest, we must also search all anonymous unions
1682 that are directly reachable. */
1685 lookup_anon_field (tree t, tree type)
1689 for (field = TYPE_FIELDS (t); field; field = TREE_CHAIN (field))
1691 if (TREE_STATIC (field))
1693 if (TREE_CODE (field) != FIELD_DECL || DECL_ARTIFICIAL (field))
1696 /* If we find it directly, return the field. */
1697 if (DECL_NAME (field) == NULL_TREE
1698 && type == TYPE_MAIN_VARIANT (TREE_TYPE (field)))
1703 /* Otherwise, it could be nested, search harder. */
1704 if (DECL_NAME (field) == NULL_TREE
1705 && ANON_AGGR_TYPE_P (TREE_TYPE (field)))
1707 tree subfield = lookup_anon_field (TREE_TYPE (field), type);
1715 /* Build an expression representing OBJECT.MEMBER. OBJECT is an
1716 expression; MEMBER is a DECL or baselink. If ACCESS_PATH is
1717 non-NULL, it indicates the path to the base used to name MEMBER.
1718 If PRESERVE_REFERENCE is true, the expression returned will have
1719 REFERENCE_TYPE if the MEMBER does. Otherwise, the expression
1720 returned will have the type referred to by the reference.
1722 This function does not perform access control; that is either done
1723 earlier by the parser when the name of MEMBER is resolved to MEMBER
1724 itself, or later when overload resolution selects one of the
1725 functions indicated by MEMBER. */
1728 build_class_member_access_expr (tree object, tree member,
1729 tree access_path, bool preserve_reference)
1733 tree result = NULL_TREE;
1735 if (error_operand_p (object) || error_operand_p (member))
1736 return error_mark_node;
1738 gcc_assert (DECL_P (member) || BASELINK_P (member));
1742 The type of the first expression shall be "class object" (of a
1744 object_type = TREE_TYPE (object);
1745 if (!currently_open_class (object_type)
1746 && !complete_type_or_else (object_type, object))
1747 return error_mark_node;
1748 if (!CLASS_TYPE_P (object_type))
1750 error ("request for member %qD in %qE, which is of non-class type %qT",
1751 member, object, object_type);
1752 return error_mark_node;
1755 /* The standard does not seem to actually say that MEMBER must be a
1756 member of OBJECT_TYPE. However, that is clearly what is
1758 if (DECL_P (member))
1760 member_scope = DECL_CLASS_CONTEXT (member);
1762 if (TREE_DEPRECATED (member))
1763 warn_deprecated_use (member);
1766 member_scope = BINFO_TYPE (BASELINK_BINFO (member));
1767 /* If MEMBER is from an anonymous aggregate, MEMBER_SCOPE will
1768 presently be the anonymous union. Go outwards until we find a
1769 type related to OBJECT_TYPE. */
1770 while (ANON_AGGR_TYPE_P (member_scope)
1771 && !same_type_ignoring_top_level_qualifiers_p (member_scope,
1773 member_scope = TYPE_CONTEXT (member_scope);
1774 if (!member_scope || !DERIVED_FROM_P (member_scope, object_type))
1776 if (TREE_CODE (member) == FIELD_DECL)
1777 error ("invalid use of nonstatic data member %qE", member);
1779 error ("%qD is not a member of %qT", member, object_type);
1780 return error_mark_node;
1783 /* Transform `(a, b).x' into `(*(a, &b)).x', `(a ? b : c).x' into
1784 `(*(a ? &b : &c)).x', and so on. A COND_EXPR is only an lvalue
1785 in the front end; only _DECLs and _REFs are lvalues in the back end. */
1787 tree temp = unary_complex_lvalue (ADDR_EXPR, object);
1789 object = build_indirect_ref (temp, NULL);
1792 /* In [expr.ref], there is an explicit list of the valid choices for
1793 MEMBER. We check for each of those cases here. */
1794 if (TREE_CODE (member) == VAR_DECL)
1796 /* A static data member. */
1798 /* If OBJECT has side-effects, they are supposed to occur. */
1799 if (TREE_SIDE_EFFECTS (object))
1800 result = build2 (COMPOUND_EXPR, TREE_TYPE (result), object, result);
1802 else if (TREE_CODE (member) == FIELD_DECL)
1804 /* A non-static data member. */
1809 null_object_p = (TREE_CODE (object) == INDIRECT_REF
1810 && integer_zerop (TREE_OPERAND (object, 0)));
1812 /* Convert OBJECT to the type of MEMBER. */
1813 if (!same_type_p (TYPE_MAIN_VARIANT (object_type),
1814 TYPE_MAIN_VARIANT (member_scope)))
1819 binfo = lookup_base (access_path ? access_path : object_type,
1820 member_scope, ba_unique, &kind);
1821 if (binfo == error_mark_node)
1822 return error_mark_node;
1824 /* It is invalid to try to get to a virtual base of a
1825 NULL object. The most common cause is invalid use of
1827 if (null_object_p && kind == bk_via_virtual)
1829 error ("invalid access to non-static data member %qD of "
1832 error ("(perhaps the %<offsetof%> macro was used incorrectly)");
1833 return error_mark_node;
1836 /* Convert to the base. */
1837 object = build_base_path (PLUS_EXPR, object, binfo,
1839 /* If we found the base successfully then we should be able
1840 to convert to it successfully. */
1841 gcc_assert (object != error_mark_node);
1844 /* Complain about other invalid uses of offsetof, even though they will
1845 give the right answer. Note that we complain whether or not they
1846 actually used the offsetof macro, since there's no way to know at this
1847 point. So we just give a warning, instead of a pedwarn. */
1848 /* Do not produce this warning for base class field references, because
1849 we know for a fact that didn't come from offsetof. This does occur
1850 in various testsuite cases where a null object is passed where a
1851 vtable access is required. */
1852 if (null_object_p && warn_invalid_offsetof
1853 && CLASSTYPE_NON_POD_P (object_type)
1854 && !DECL_FIELD_IS_BASE (member)
1855 && !skip_evaluation)
1857 warning (0, "invalid access to non-static data member %qD of NULL object",
1859 warning (0, "(perhaps the %<offsetof%> macro was used incorrectly)");
1862 /* If MEMBER is from an anonymous aggregate, we have converted
1863 OBJECT so that it refers to the class containing the
1864 anonymous union. Generate a reference to the anonymous union
1865 itself, and recur to find MEMBER. */
1866 if (ANON_AGGR_TYPE_P (DECL_CONTEXT (member))
1867 /* When this code is called from build_field_call, the
1868 object already has the type of the anonymous union.
1869 That is because the COMPONENT_REF was already
1870 constructed, and was then disassembled before calling
1871 build_field_call. After the function-call code is
1872 cleaned up, this waste can be eliminated. */
1873 && (!same_type_ignoring_top_level_qualifiers_p
1874 (TREE_TYPE (object), DECL_CONTEXT (member))))
1876 tree anonymous_union;
1878 anonymous_union = lookup_anon_field (TREE_TYPE (object),
1879 DECL_CONTEXT (member));
1880 object = build_class_member_access_expr (object,
1882 /*access_path=*/NULL_TREE,
1883 preserve_reference);
1886 /* Compute the type of the field, as described in [expr.ref]. */
1887 type_quals = TYPE_UNQUALIFIED;
1888 member_type = TREE_TYPE (member);
1889 if (TREE_CODE (member_type) != REFERENCE_TYPE)
1891 type_quals = (cp_type_quals (member_type)
1892 | cp_type_quals (object_type));
1894 /* A field is const (volatile) if the enclosing object, or the
1895 field itself, is const (volatile). But, a mutable field is
1896 not const, even within a const object. */
1897 if (DECL_MUTABLE_P (member))
1898 type_quals &= ~TYPE_QUAL_CONST;
1899 member_type = cp_build_qualified_type (member_type, type_quals);
1902 result = build3 (COMPONENT_REF, member_type, object, member,
1904 result = fold_if_not_in_template (result);
1906 /* Mark the expression const or volatile, as appropriate. Even
1907 though we've dealt with the type above, we still have to mark the
1908 expression itself. */
1909 if (type_quals & TYPE_QUAL_CONST)
1910 TREE_READONLY (result) = 1;
1911 if (type_quals & TYPE_QUAL_VOLATILE)
1912 TREE_THIS_VOLATILE (result) = 1;
1914 else if (BASELINK_P (member))
1916 /* The member is a (possibly overloaded) member function. */
1920 /* If the MEMBER is exactly one static member function, then we
1921 know the type of the expression. Otherwise, we must wait
1922 until overload resolution has been performed. */
1923 functions = BASELINK_FUNCTIONS (member);
1924 if (TREE_CODE (functions) == FUNCTION_DECL
1925 && DECL_STATIC_FUNCTION_P (functions))
1926 type = TREE_TYPE (functions);
1928 type = unknown_type_node;
1929 /* Note that we do not convert OBJECT to the BASELINK_BINFO
1930 base. That will happen when the function is called. */
1931 result = build3 (COMPONENT_REF, type, object, member, NULL_TREE);
1933 else if (TREE_CODE (member) == CONST_DECL)
1935 /* The member is an enumerator. */
1937 /* If OBJECT has side-effects, they are supposed to occur. */
1938 if (TREE_SIDE_EFFECTS (object))
1939 result = build2 (COMPOUND_EXPR, TREE_TYPE (result),
1944 error ("invalid use of %qD", member);
1945 return error_mark_node;
1948 if (!preserve_reference)
1951 If E2 is declared to have type "reference to T", then ... the
1952 type of E1.E2 is T. */
1953 result = convert_from_reference (result);
1958 /* Return the destructor denoted by OBJECT.SCOPE::~DTOR_NAME, or, if
1959 SCOPE is NULL, by OBJECT.~DTOR_NAME. */
1962 lookup_destructor (tree object, tree scope, tree dtor_name)
1964 tree object_type = TREE_TYPE (object);
1965 tree dtor_type = TREE_OPERAND (dtor_name, 0);
1968 if (scope && !check_dtor_name (scope, dtor_type))
1970 error ("qualified type %qT does not match destructor name ~%qT",
1972 return error_mark_node;
1974 if (!DERIVED_FROM_P (dtor_type, TYPE_MAIN_VARIANT (object_type)))
1976 error ("the type being destroyed is %qT, but the destructor refers to %qT",
1977 TYPE_MAIN_VARIANT (object_type), dtor_type);
1978 return error_mark_node;
1980 expr = lookup_member (dtor_type, complete_dtor_identifier,
1981 /*protect=*/1, /*want_type=*/false);
1982 expr = (adjust_result_of_qualified_name_lookup
1983 (expr, dtor_type, object_type));
1987 /* An expression of the form "A::template B" has been resolved to
1988 DECL. Issue a diagnostic if B is not a template or template
1992 check_template_keyword (tree decl)
1994 /* The standard says:
1998 If a name prefixed by the keyword template is not a member
1999 template, the program is ill-formed.
2001 DR 228 removed the restriction that the template be a member
2004 DR 96, if accepted would add the further restriction that explicit
2005 template arguments must be provided if the template keyword is
2006 used, but, as of 2005-10-16, that DR is still in "drafting". If
2007 this DR is accepted, then the semantic checks here can be
2008 simplified, as the entity named must in fact be a template
2009 specialization, rather than, as at present, a set of overloaded
2010 functions containing at least one template function. */
2011 if (TREE_CODE (decl) != TEMPLATE_DECL
2012 && TREE_CODE (decl) != TEMPLATE_ID_EXPR)
2014 if (!is_overloaded_fn (decl))
2015 pedwarn ("%qD is not a template", decl);
2020 if (BASELINK_P (fns))
2021 fns = BASELINK_FUNCTIONS (fns);
2024 tree fn = OVL_CURRENT (fns);
2025 if (TREE_CODE (fn) == TEMPLATE_DECL
2026 || TREE_CODE (fn) == TEMPLATE_ID_EXPR)
2028 if (TREE_CODE (fn) == FUNCTION_DECL
2029 && DECL_USE_TEMPLATE (fn)
2030 && PRIMARY_TEMPLATE_P (DECL_TI_TEMPLATE (fn)))
2032 fns = OVL_NEXT (fns);
2035 pedwarn ("%qD is not a template", decl);
2040 /* This function is called by the parser to process a class member
2041 access expression of the form OBJECT.NAME. NAME is a node used by
2042 the parser to represent a name; it is not yet a DECL. It may,
2043 however, be a BASELINK where the BASELINK_FUNCTIONS is a
2044 TEMPLATE_ID_EXPR. Templates must be looked up by the parser, and
2045 there is no reason to do the lookup twice, so the parser keeps the
2046 BASELINK. TEMPLATE_P is true iff NAME was explicitly declared to
2047 be a template via the use of the "A::template B" syntax. */
2050 finish_class_member_access_expr (tree object, tree name, bool template_p)
2055 tree access_path = NULL_TREE;
2056 tree orig_object = object;
2057 tree orig_name = name;
2059 if (object == error_mark_node || name == error_mark_node)
2060 return error_mark_node;
2062 /* If OBJECT is an ObjC class instance, we must obey ObjC access rules. */
2063 if (!objc_is_public (object, name))
2064 return error_mark_node;
2066 object_type = TREE_TYPE (object);
2068 if (processing_template_decl)
2070 if (/* If OBJECT_TYPE is dependent, so is OBJECT.NAME. */
2071 dependent_type_p (object_type)
2072 /* If NAME is just an IDENTIFIER_NODE, then the expression
2074 || TREE_CODE (object) == IDENTIFIER_NODE
2075 /* If NAME is "f<args>", where either 'f' or 'args' is
2076 dependent, then the expression is dependent. */
2077 || (TREE_CODE (name) == TEMPLATE_ID_EXPR
2078 && dependent_template_id_p (TREE_OPERAND (name, 0),
2079 TREE_OPERAND (name, 1)))
2080 /* If NAME is "T::X" where "T" is dependent, then the
2081 expression is dependent. */
2082 || (TREE_CODE (name) == SCOPE_REF
2083 && TYPE_P (TREE_OPERAND (name, 0))
2084 && dependent_type_p (TREE_OPERAND (name, 0))))
2085 return build_min_nt (COMPONENT_REF, object, name, NULL_TREE);
2086 object = build_non_dependent_expr (object);
2091 The type of the first expression shall be "class object" (of a
2093 if (!currently_open_class (object_type)
2094 && !complete_type_or_else (object_type, object))
2095 return error_mark_node;
2096 if (!CLASS_TYPE_P (object_type))
2098 error ("request for member %qD in %qE, which is of non-class type %qT",
2099 name, object, object_type);
2100 return error_mark_node;
2103 if (BASELINK_P (name))
2104 /* A member function that has already been looked up. */
2108 bool is_template_id = false;
2109 tree template_args = NULL_TREE;
2112 if (TREE_CODE (name) == TEMPLATE_ID_EXPR)
2114 is_template_id = true;
2115 template_args = TREE_OPERAND (name, 1);
2116 name = TREE_OPERAND (name, 0);
2118 if (TREE_CODE (name) == OVERLOAD)
2119 name = DECL_NAME (get_first_fn (name));
2120 else if (DECL_P (name))
2121 name = DECL_NAME (name);
2124 if (TREE_CODE (name) == SCOPE_REF)
2126 /* A qualified name. The qualifying class or namespace `S'
2127 has already been looked up; it is either a TYPE or a
2129 scope = TREE_OPERAND (name, 0);
2130 name = TREE_OPERAND (name, 1);
2132 /* If SCOPE is a namespace, then the qualified name does not
2133 name a member of OBJECT_TYPE. */
2134 if (TREE_CODE (scope) == NAMESPACE_DECL)
2136 error ("%<%D::%D%> is not a member of %qT",
2137 scope, name, object_type);
2138 return error_mark_node;
2141 gcc_assert (CLASS_TYPE_P (scope));
2142 gcc_assert (TREE_CODE (name) == IDENTIFIER_NODE
2143 || TREE_CODE (name) == BIT_NOT_EXPR);
2145 /* Find the base of OBJECT_TYPE corresponding to SCOPE. */
2146 access_path = lookup_base (object_type, scope, ba_check, NULL);
2147 if (access_path == error_mark_node)
2148 return error_mark_node;
2151 error ("%qT is not a base of %qT", scope, object_type);
2152 return error_mark_node;
2158 access_path = object_type;
2161 if (TREE_CODE (name) == BIT_NOT_EXPR)
2162 member = lookup_destructor (object, scope, name);
2165 /* Look up the member. */
2166 member = lookup_member (access_path, name, /*protect=*/1,
2167 /*want_type=*/false);
2168 if (member == NULL_TREE)
2170 error ("%qD has no member named %qE", object_type, name);
2171 return error_mark_node;
2173 if (member == error_mark_node)
2174 return error_mark_node;
2179 tree template = member;
2181 if (BASELINK_P (template))
2182 template = lookup_template_function (template, template_args);
2185 error ("%qD is not a member template function", name);
2186 return error_mark_node;
2191 if (TREE_DEPRECATED (member))
2192 warn_deprecated_use (member);
2195 check_template_keyword (member);
2197 expr = build_class_member_access_expr (object, member, access_path,
2198 /*preserve_reference=*/false);
2199 if (processing_template_decl && expr != error_mark_node)
2201 if (BASELINK_P (member))
2203 if (TREE_CODE (orig_name) == SCOPE_REF)
2204 BASELINK_QUALIFIED_P (member) = 1;
2207 return build_min_non_dep (COMPONENT_REF, expr,
2208 orig_object, orig_name,
2215 /* Return an expression for the MEMBER_NAME field in the internal
2216 representation of PTRMEM, a pointer-to-member function. (Each
2217 pointer-to-member function type gets its own RECORD_TYPE so it is
2218 more convenient to access the fields by name than by FIELD_DECL.)
2219 This routine converts the NAME to a FIELD_DECL and then creates the
2220 node for the complete expression. */
2223 build_ptrmemfunc_access_expr (tree ptrmem, tree member_name)
2229 /* This code is a stripped down version of
2230 build_class_member_access_expr. It does not work to use that
2231 routine directly because it expects the object to be of class
2233 ptrmem_type = TREE_TYPE (ptrmem);
2234 gcc_assert (TYPE_PTRMEMFUNC_P (ptrmem_type));
2235 member = lookup_member (ptrmem_type, member_name, /*protect=*/0,
2236 /*want_type=*/false);
2237 member_type = cp_build_qualified_type (TREE_TYPE (member),
2238 cp_type_quals (ptrmem_type));
2239 return fold_build3 (COMPONENT_REF, member_type,
2240 ptrmem, member, NULL_TREE);
2243 /* Given an expression PTR for a pointer, return an expression
2244 for the value pointed to.
2245 ERRORSTRING is the name of the operator to appear in error messages.
2247 This function may need to overload OPERATOR_FNNAME.
2248 Must also handle REFERENCE_TYPEs for C++. */
2251 build_x_indirect_ref (tree expr, const char *errorstring)
2253 tree orig_expr = expr;
2256 if (processing_template_decl)
2258 if (type_dependent_expression_p (expr))
2259 return build_min_nt (INDIRECT_REF, expr);
2260 expr = build_non_dependent_expr (expr);
2263 rval = build_new_op (INDIRECT_REF, LOOKUP_NORMAL, expr, NULL_TREE,
2264 NULL_TREE, /*overloaded_p=*/NULL);
2266 rval = build_indirect_ref (expr, errorstring);
2268 if (processing_template_decl && rval != error_mark_node)
2269 return build_min_non_dep (INDIRECT_REF, rval, orig_expr);
2275 build_indirect_ref (tree ptr, const char *errorstring)
2279 if (ptr == error_mark_node)
2280 return error_mark_node;
2282 if (ptr == current_class_ptr)
2283 return current_class_ref;
2285 pointer = (TREE_CODE (TREE_TYPE (ptr)) == REFERENCE_TYPE
2286 ? ptr : decay_conversion (ptr));
2287 type = TREE_TYPE (pointer);
2289 if (POINTER_TYPE_P (type))
2293 If the type of the expression is "pointer to T," the type
2294 of the result is "T."
2296 We must use the canonical variant because certain parts of
2297 the back end, like fold, do pointer comparisons between
2299 tree t = canonical_type_variant (TREE_TYPE (type));
2301 if (VOID_TYPE_P (t))
2303 /* A pointer to incomplete type (other than cv void) can be
2304 dereferenced [expr.unary.op]/1 */
2305 error ("%qT is not a pointer-to-object type", type);
2306 return error_mark_node;
2308 else if (TREE_CODE (pointer) == ADDR_EXPR
2309 && same_type_p (t, TREE_TYPE (TREE_OPERAND (pointer, 0))))
2310 /* The POINTER was something like `&x'. We simplify `*&x' to
2312 return TREE_OPERAND (pointer, 0);
2315 tree ref = build1 (INDIRECT_REF, t, pointer);
2317 /* We *must* set TREE_READONLY when dereferencing a pointer to const,
2318 so that we get the proper error message if the result is used
2319 to assign to. Also, &* is supposed to be a no-op. */
2320 TREE_READONLY (ref) = CP_TYPE_CONST_P (t);
2321 TREE_THIS_VOLATILE (ref) = CP_TYPE_VOLATILE_P (t);
2322 TREE_SIDE_EFFECTS (ref)
2323 = (TREE_THIS_VOLATILE (ref) || TREE_SIDE_EFFECTS (pointer));
2327 /* `pointer' won't be an error_mark_node if we were given a
2328 pointer to member, so it's cool to check for this here. */
2329 else if (TYPE_PTR_TO_MEMBER_P (type))
2330 error ("invalid use of %qs on pointer to member", errorstring);
2331 else if (pointer != error_mark_node)
2334 error ("invalid type argument of %qs", errorstring);
2336 error ("invalid type argument");
2338 return error_mark_node;
2341 /* This handles expressions of the form "a[i]", which denotes
2344 This is logically equivalent in C to *(a+i), but we may do it differently.
2345 If A is a variable or a member, we generate a primitive ARRAY_REF.
2346 This avoids forcing the array out of registers, and can work on
2347 arrays that are not lvalues (for example, members of structures returned
2350 If INDEX is of some user-defined type, it must be converted to
2351 integer type. Otherwise, to make a compatible PLUS_EXPR, it
2352 will inherit the type of the array, which will be some pointer type. */
2355 build_array_ref (tree array, tree idx)
2359 error ("subscript missing in array reference");
2360 return error_mark_node;
2363 if (TREE_TYPE (array) == error_mark_node
2364 || TREE_TYPE (idx) == error_mark_node)
2365 return error_mark_node;
2367 /* If ARRAY is a COMPOUND_EXPR or COND_EXPR, move our reference
2369 switch (TREE_CODE (array))
2373 tree value = build_array_ref (TREE_OPERAND (array, 1), idx);
2374 return build2 (COMPOUND_EXPR, TREE_TYPE (value),
2375 TREE_OPERAND (array, 0), value);
2379 return build_conditional_expr
2380 (TREE_OPERAND (array, 0),
2381 build_array_ref (TREE_OPERAND (array, 1), idx),
2382 build_array_ref (TREE_OPERAND (array, 2), idx));
2388 if (TREE_CODE (TREE_TYPE (array)) == ARRAY_TYPE)
2392 warn_array_subscript_with_type_char (idx);
2394 if (!INTEGRAL_OR_ENUMERATION_TYPE_P (TREE_TYPE (idx)))
2396 error ("array subscript is not an integer");
2397 return error_mark_node;
2400 /* Apply integral promotions *after* noticing character types.
2401 (It is unclear why we do these promotions -- the standard
2402 does not say that we should. In fact, the natural thing would
2403 seem to be to convert IDX to ptrdiff_t; we're performing
2404 pointer arithmetic.) */
2405 idx = perform_integral_promotions (idx);
2407 /* An array that is indexed by a non-constant
2408 cannot be stored in a register; we must be able to do
2409 address arithmetic on its address.
2410 Likewise an array of elements of variable size. */
2411 if (TREE_CODE (idx) != INTEGER_CST
2412 || (COMPLETE_TYPE_P (TREE_TYPE (TREE_TYPE (array)))
2413 && (TREE_CODE (TYPE_SIZE (TREE_TYPE (TREE_TYPE (array))))
2416 if (!cxx_mark_addressable (array))
2417 return error_mark_node;
2420 /* An array that is indexed by a constant value which is not within
2421 the array bounds cannot be stored in a register either; because we
2422 would get a crash in store_bit_field/extract_bit_field when trying
2423 to access a non-existent part of the register. */
2424 if (TREE_CODE (idx) == INTEGER_CST
2425 && TYPE_DOMAIN (TREE_TYPE (array))
2426 && ! int_fits_type_p (idx, TYPE_DOMAIN (TREE_TYPE (array))))
2428 if (!cxx_mark_addressable (array))
2429 return error_mark_node;
2432 if (pedantic && !lvalue_p (array))
2433 pedwarn ("ISO C++ forbids subscripting non-lvalue array");
2435 /* Note in C++ it is valid to subscript a `register' array, since
2436 it is valid to take the address of something with that
2437 storage specification. */
2441 while (TREE_CODE (foo) == COMPONENT_REF)
2442 foo = TREE_OPERAND (foo, 0);
2443 if (TREE_CODE (foo) == VAR_DECL && DECL_REGISTER (foo))
2444 warning (OPT_Wextra, "subscripting array declared %<register%>");
2447 type = TREE_TYPE (TREE_TYPE (array));
2448 rval = build4 (ARRAY_REF, type, array, idx, NULL_TREE, NULL_TREE);
2449 /* Array ref is const/volatile if the array elements are
2450 or if the array is.. */
2451 TREE_READONLY (rval)
2452 |= (CP_TYPE_CONST_P (type) | TREE_READONLY (array));
2453 TREE_SIDE_EFFECTS (rval)
2454 |= (CP_TYPE_VOLATILE_P (type) | TREE_SIDE_EFFECTS (array));
2455 TREE_THIS_VOLATILE (rval)
2456 |= (CP_TYPE_VOLATILE_P (type) | TREE_THIS_VOLATILE (array));
2457 return require_complete_type (fold_if_not_in_template (rval));
2461 tree ar = default_conversion (array);
2462 tree ind = default_conversion (idx);
2464 /* Put the integer in IND to simplify error checking. */
2465 if (TREE_CODE (TREE_TYPE (ar)) == INTEGER_TYPE)
2472 if (ar == error_mark_node)
2475 if (TREE_CODE (TREE_TYPE (ar)) != POINTER_TYPE)
2477 error ("subscripted value is neither array nor pointer");
2478 return error_mark_node;
2480 if (TREE_CODE (TREE_TYPE (ind)) != INTEGER_TYPE)
2482 error ("array subscript is not an integer");
2483 return error_mark_node;
2486 warn_array_subscript_with_type_char (idx);
2488 return build_indirect_ref (cp_build_binary_op (PLUS_EXPR, ar, ind),
2493 /* Resolve a pointer to member function. INSTANCE is the object
2494 instance to use, if the member points to a virtual member.
2496 This used to avoid checking for virtual functions if basetype
2497 has no virtual functions, according to an earlier ANSI draft.
2498 With the final ISO C++ rules, such an optimization is
2499 incorrect: A pointer to a derived member can be static_cast
2500 to pointer-to-base-member, as long as the dynamic object
2501 later has the right member. */
2504 get_member_function_from_ptrfunc (tree *instance_ptrptr, tree function)
2506 if (TREE_CODE (function) == OFFSET_REF)
2507 function = TREE_OPERAND (function, 1);
2509 if (TYPE_PTRMEMFUNC_P (TREE_TYPE (function)))
2511 tree idx, delta, e1, e2, e3, vtbl, basetype;
2512 tree fntype = TYPE_PTRMEMFUNC_FN_TYPE (TREE_TYPE (function));
2514 tree instance_ptr = *instance_ptrptr;
2515 tree instance_save_expr = 0;
2516 if (instance_ptr == error_mark_node)
2518 if (TREE_CODE (function) == PTRMEM_CST)
2520 /* Extracting the function address from a pmf is only
2521 allowed with -Wno-pmf-conversions. It only works for
2523 e1 = build_addr_func (PTRMEM_CST_MEMBER (function));
2524 e1 = convert (fntype, e1);
2529 error ("object missing in use of %qE", function);
2530 return error_mark_node;
2534 if (TREE_SIDE_EFFECTS (instance_ptr))
2535 instance_ptr = instance_save_expr = save_expr (instance_ptr);
2537 if (TREE_SIDE_EFFECTS (function))
2538 function = save_expr (function);
2540 /* Start by extracting all the information from the PMF itself. */
2541 e3 = pfn_from_ptrmemfunc (function);
2542 delta = build_ptrmemfunc_access_expr (function, delta_identifier);
2543 idx = build1 (NOP_EXPR, vtable_index_type, e3);
2544 switch (TARGET_PTRMEMFUNC_VBIT_LOCATION)
2546 case ptrmemfunc_vbit_in_pfn:
2547 e1 = cp_build_binary_op (BIT_AND_EXPR, idx, integer_one_node);
2548 idx = cp_build_binary_op (MINUS_EXPR, idx, integer_one_node);
2551 case ptrmemfunc_vbit_in_delta:
2552 e1 = cp_build_binary_op (BIT_AND_EXPR, delta, integer_one_node);
2553 delta = cp_build_binary_op (RSHIFT_EXPR, delta, integer_one_node);
2560 /* Convert down to the right base before using the instance. A
2561 special case is that in a pointer to member of class C, C may
2562 be incomplete. In that case, the function will of course be
2563 a member of C, and no conversion is required. In fact,
2564 lookup_base will fail in that case, because incomplete
2565 classes do not have BINFOs. */
2566 basetype = TYPE_METHOD_BASETYPE (TREE_TYPE (fntype));
2567 if (!same_type_ignoring_top_level_qualifiers_p
2568 (basetype, TREE_TYPE (TREE_TYPE (instance_ptr))))
2570 basetype = lookup_base (TREE_TYPE (TREE_TYPE (instance_ptr)),
2571 basetype, ba_check, NULL);
2572 instance_ptr = build_base_path (PLUS_EXPR, instance_ptr, basetype,
2574 if (instance_ptr == error_mark_node)
2575 return error_mark_node;
2577 /* ...and then the delta in the PMF. */
2578 instance_ptr = build2 (PLUS_EXPR, TREE_TYPE (instance_ptr),
2579 instance_ptr, delta);
2581 /* Hand back the adjusted 'this' argument to our caller. */
2582 *instance_ptrptr = instance_ptr;
2584 /* Next extract the vtable pointer from the object. */
2585 vtbl = build1 (NOP_EXPR, build_pointer_type (vtbl_ptr_type_node),
2587 vtbl = build_indirect_ref (vtbl, NULL);
2589 /* Finally, extract the function pointer from the vtable. */
2590 e2 = fold_build2 (PLUS_EXPR, TREE_TYPE (vtbl), vtbl, idx);
2591 e2 = build_indirect_ref (e2, NULL);
2592 TREE_CONSTANT (e2) = 1;
2593 TREE_INVARIANT (e2) = 1;
2595 /* When using function descriptors, the address of the
2596 vtable entry is treated as a function pointer. */
2597 if (TARGET_VTABLE_USES_DESCRIPTORS)
2598 e2 = build1 (NOP_EXPR, TREE_TYPE (e2),
2599 build_unary_op (ADDR_EXPR, e2, /*noconvert=*/1));
2601 TREE_TYPE (e2) = TREE_TYPE (e3);
2602 e1 = build_conditional_expr (e1, e2, e3);
2604 /* Make sure this doesn't get evaluated first inside one of the
2605 branches of the COND_EXPR. */
2606 if (instance_save_expr)
2607 e1 = build2 (COMPOUND_EXPR, TREE_TYPE (e1),
2608 instance_save_expr, e1);
2616 build_function_call (tree function, tree params)
2618 tree fntype, fndecl;
2619 tree name = NULL_TREE;
2621 tree original = function;
2622 int nargs, parm_types_len;
2626 /* For Objective-C, convert any calls via a cast to OBJC_TYPE_REF
2627 expressions, like those used for ObjC messenger dispatches. */
2628 function = objc_rewrite_function_call (function, params);
2630 /* build_c_cast puts on a NOP_EXPR to make the result not an lvalue.
2631 Strip such NOP_EXPRs, since FUNCTION is used in non-lvalue context. */
2632 if (TREE_CODE (function) == NOP_EXPR
2633 && TREE_TYPE (function) == TREE_TYPE (TREE_OPERAND (function, 0)))
2634 function = TREE_OPERAND (function, 0);
2636 if (TREE_CODE (function) == FUNCTION_DECL)
2638 name = DECL_NAME (function);
2640 mark_used (function);
2643 /* Convert anything with function type to a pointer-to-function. */
2644 if (pedantic && DECL_MAIN_P (function))
2645 pedwarn ("ISO C++ forbids calling %<::main%> from within program");
2647 /* Differs from default_conversion by not setting TREE_ADDRESSABLE
2648 (because calling an inline function does not mean the function
2649 needs to be separately compiled). */
2651 if (DECL_INLINE (function))
2652 function = inline_conversion (function);
2654 function = build_addr_func (function);
2660 function = build_addr_func (function);
2663 if (function == error_mark_node)
2664 return error_mark_node;
2666 fntype = TREE_TYPE (function);
2668 if (TYPE_PTRMEMFUNC_P (fntype))
2670 error ("must use %<.*%> or %<->*%> to call pointer-to-member "
2671 "function in %<%E (...)%>",
2673 return error_mark_node;
2676 is_method = (TREE_CODE (fntype) == POINTER_TYPE
2677 && TREE_CODE (TREE_TYPE (fntype)) == METHOD_TYPE);
2679 if (!((TREE_CODE (fntype) == POINTER_TYPE
2680 && TREE_CODE (TREE_TYPE (fntype)) == FUNCTION_TYPE)
2682 || TREE_CODE (function) == TEMPLATE_ID_EXPR))
2684 error ("%qE cannot be used as a function", original);
2685 return error_mark_node;
2688 /* fntype now gets the type of function pointed to. */
2689 fntype = TREE_TYPE (fntype);
2690 parm_types = TYPE_ARG_TYPES (fntype);
2692 /* Allocate storage for converted arguments. */
2693 parm_types_len = list_length (parm_types);
2694 nargs = list_length (params);
2695 if (parm_types_len > nargs)
2696 nargs = parm_types_len;
2697 argarray = (tree *) alloca (nargs * sizeof (tree));
2699 /* Convert the parameters to the types declared in the
2700 function prototype, or apply default promotions. */
2701 nargs = convert_arguments (nargs, argarray, parm_types,
2702 params, fndecl, LOOKUP_NORMAL);
2704 return error_mark_node;
2706 /* Check for errors in format strings and inappropriately
2709 check_function_arguments (TYPE_ATTRIBUTES (fntype), nargs, argarray,
2712 return build_cxx_call (function, nargs, argarray);
2715 /* Convert the actual parameter expressions in the list VALUES
2716 to the types in the list TYPELIST.
2717 If parmdecls is exhausted, or when an element has NULL as its type,
2718 perform the default conversions.
2720 Store the converted arguments in ARGARRAY. NARGS is the size of this array.
2722 NAME is an IDENTIFIER_NODE or 0. It is used only for error messages.
2724 This is also where warnings about wrong number of args are generated.
2726 Returns the actual number of arguments processed (which might be less
2727 than NARGS), or -1 on error.
2729 VALUES is a chain of TREE_LIST nodes with the elements of the list
2730 in the TREE_VALUE slots of those nodes.
2732 In C++, unspecified trailing parameters can be filled in with their
2733 default arguments, if such were specified. Do so here. */
2736 convert_arguments (int nargs, tree *argarray,
2737 tree typelist, tree values, tree fndecl, int flags)
2739 tree typetail, valtail;
2740 const char *called_thing = 0;
2743 /* Argument passing is always copy-initialization. */
2744 flags |= LOOKUP_ONLYCONVERTING;
2748 if (TREE_CODE (TREE_TYPE (fndecl)) == METHOD_TYPE)
2750 if (DECL_NAME (fndecl) == NULL_TREE
2751 || IDENTIFIER_HAS_TYPE_VALUE (DECL_NAME (fndecl)))
2752 called_thing = "constructor";
2754 called_thing = "member function";
2757 called_thing = "function";
2760 for (valtail = values, typetail = typelist;
2762 valtail = TREE_CHAIN (valtail), i++)
2764 tree type = typetail ? TREE_VALUE (typetail) : 0;
2765 tree val = TREE_VALUE (valtail);
2767 if (val == error_mark_node || type == error_mark_node)
2770 if (type == void_type_node)
2774 error ("too many arguments to %s %q+#D", called_thing, fndecl);
2775 error ("at this point in file");
2778 error ("too many arguments to function");
2782 /* build_c_cast puts on a NOP_EXPR to make the result not an lvalue.
2783 Strip such NOP_EXPRs, since VAL is used in non-lvalue context. */
2784 if (TREE_CODE (val) == NOP_EXPR
2785 && TREE_TYPE (val) == TREE_TYPE (TREE_OPERAND (val, 0))
2786 && (type == 0 || TREE_CODE (type) != REFERENCE_TYPE))
2787 val = TREE_OPERAND (val, 0);
2789 if (type == 0 || TREE_CODE (type) != REFERENCE_TYPE)
2791 if (TREE_CODE (TREE_TYPE (val)) == ARRAY_TYPE
2792 || TREE_CODE (TREE_TYPE (val)) == FUNCTION_TYPE
2793 || TREE_CODE (TREE_TYPE (val)) == METHOD_TYPE)
2794 val = decay_conversion (val);
2797 if (val == error_mark_node)
2802 /* Formal parm type is specified by a function prototype. */
2805 if (!COMPLETE_TYPE_P (complete_type (type)))
2808 error ("parameter %P of %qD has incomplete type %qT",
2811 error ("parameter %P has incomplete type %qT", i, type);
2812 parmval = error_mark_node;
2816 parmval = convert_for_initialization
2817 (NULL_TREE, type, val, flags,
2818 "argument passing", fndecl, i);
2819 parmval = convert_for_arg_passing (type, parmval);
2822 if (parmval == error_mark_node)
2825 argarray[i] = parmval;
2829 if (fndecl && DECL_BUILT_IN (fndecl)
2830 && DECL_FUNCTION_CODE (fndecl) == BUILT_IN_CONSTANT_P)
2831 /* Don't do ellipsis conversion for __built_in_constant_p
2832 as this will result in spurious warnings for non-POD
2834 val = require_complete_type (val);
2836 val = convert_arg_to_ellipsis (val);
2842 typetail = TREE_CHAIN (typetail);
2845 if (typetail != 0 && typetail != void_list_node)
2847 /* See if there are default arguments that can be used. */
2848 if (TREE_PURPOSE (typetail)
2849 && TREE_CODE (TREE_PURPOSE (typetail)) != DEFAULT_ARG)
2851 for (; typetail != void_list_node; ++i)
2854 = convert_default_arg (TREE_VALUE (typetail),
2855 TREE_PURPOSE (typetail),
2858 if (parmval == error_mark_node)
2861 argarray[i] = parmval;
2862 typetail = TREE_CHAIN (typetail);
2863 /* ends with `...'. */
2864 if (typetail == NULL_TREE)
2872 error ("too few arguments to %s %q+#D", called_thing, fndecl);
2873 error ("at this point in file");
2876 error ("too few arguments to function");
2881 gcc_assert (i <= nargs);
2885 /* Build a binary-operation expression, after performing default
2886 conversions on the operands. CODE is the kind of expression to
2887 build. ARG1 and ARG2 are the arguments. ARG1_CODE and ARG2_CODE
2888 are the tree codes which correspond to ARG1 and ARG2 when issuing
2889 warnings about possibly misplaced parentheses. They may differ
2890 from the TREE_CODE of ARG1 and ARG2 if the parser has done constant
2891 folding (e.g., if the parser sees "a | 1 + 1", it may call this
2892 routine with ARG2 being an INTEGER_CST and ARG2_CODE == PLUS_EXPR).
2893 To avoid issuing any parentheses warnings, pass ARG1_CODE and/or
2894 ARG2_CODE as ERROR_MARK. */
2897 build_x_binary_op (enum tree_code code, tree arg1, enum tree_code arg1_code,
2898 tree arg2, enum tree_code arg2_code, bool *overloaded_p)
2907 if (processing_template_decl)
2909 if (type_dependent_expression_p (arg1)
2910 || type_dependent_expression_p (arg2))
2911 return build_min_nt (code, arg1, arg2);
2912 arg1 = build_non_dependent_expr (arg1);
2913 arg2 = build_non_dependent_expr (arg2);
2916 if (code == DOTSTAR_EXPR)
2917 expr = build_m_component_ref (arg1, arg2);
2919 expr = build_new_op (code, LOOKUP_NORMAL, arg1, arg2, NULL_TREE,
2922 /* Check for cases such as x+y<<z which users are likely to
2923 misinterpret. But don't warn about obj << x + y, since that is a
2924 common idiom for I/O. */
2925 if (warn_parentheses
2926 && !processing_template_decl
2927 && !error_operand_p (arg1)
2928 && !error_operand_p (arg2)
2929 && (code != LSHIFT_EXPR
2930 || !CLASS_TYPE_P (TREE_TYPE (arg1))))
2931 warn_about_parentheses (code, arg1_code, arg2_code);
2933 if (processing_template_decl && expr != error_mark_node)
2934 return build_min_non_dep (code, expr, orig_arg1, orig_arg2);
2939 /* Build a binary-operation expression without default conversions.
2940 CODE is the kind of expression to build.
2941 This function differs from `build' in several ways:
2942 the data type of the result is computed and recorded in it,
2943 warnings are generated if arg data types are invalid,
2944 special handling for addition and subtraction of pointers is known,
2945 and some optimization is done (operations on narrow ints
2946 are done in the narrower type when that gives the same result).
2947 Constant folding is also done before the result is returned.
2949 Note that the operands will never have enumeral types
2950 because either they have just had the default conversions performed
2951 or they have both just been converted to some other type in which
2952 the arithmetic is to be done.
2954 C++: must do special pointer arithmetic when implementing
2955 multiple inheritance, and deal with pointer to member functions. */
2958 build_binary_op (enum tree_code code, tree orig_op0, tree orig_op1,
2959 int convert_p ATTRIBUTE_UNUSED)
2962 enum tree_code code0, code1;
2964 const char *invalid_op_diag;
2966 /* Expression code to give to the expression when it is built.
2967 Normally this is CODE, which is what the caller asked for,
2968 but in some special cases we change it. */
2969 enum tree_code resultcode = code;
2971 /* Data type in which the computation is to be performed.
2972 In the simplest cases this is the common type of the arguments. */
2973 tree result_type = NULL;
2975 /* Nonzero means operands have already been type-converted
2976 in whatever way is necessary.
2977 Zero means they need to be converted to RESULT_TYPE. */
2980 /* Nonzero means create the expression with this type, rather than
2982 tree build_type = 0;
2984 /* Nonzero means after finally constructing the expression
2985 convert it to this type. */
2986 tree final_type = 0;
2990 /* Nonzero if this is an operation like MIN or MAX which can
2991 safely be computed in short if both args are promoted shorts.
2992 Also implies COMMON.
2993 -1 indicates a bitwise operation; this makes a difference
2994 in the exact conditions for when it is safe to do the operation
2995 in a narrower mode. */
2998 /* Nonzero if this is a comparison operation;
2999 if both args are promoted shorts, compare the original shorts.
3000 Also implies COMMON. */
3001 int short_compare = 0;
3003 /* Nonzero if this is a right-shift operation, which can be computed on the
3004 original short and then promoted if the operand is a promoted short. */
3005 int short_shift = 0;
3007 /* Nonzero means set RESULT_TYPE to the common type of the args. */
3010 /* True if both operands have arithmetic type. */
3011 bool arithmetic_types_p;
3013 /* Apply default conversions. */
3017 if (code == TRUTH_AND_EXPR || code == TRUTH_ANDIF_EXPR
3018 || code == TRUTH_OR_EXPR || code == TRUTH_ORIF_EXPR
3019 || code == TRUTH_XOR_EXPR)
3021 if (!really_overloaded_fn (op0))
3022 op0 = decay_conversion (op0);
3023 if (!really_overloaded_fn (op1))
3024 op1 = decay_conversion (op1);
3028 if (!really_overloaded_fn (op0))
3029 op0 = default_conversion (op0);
3030 if (!really_overloaded_fn (op1))
3031 op1 = default_conversion (op1);
3034 /* Strip NON_LVALUE_EXPRs, etc., since we aren't using as an lvalue. */
3035 STRIP_TYPE_NOPS (op0);
3036 STRIP_TYPE_NOPS (op1);
3038 /* DTRT if one side is an overloaded function, but complain about it. */
3039 if (type_unknown_p (op0))
3041 tree t = instantiate_type (TREE_TYPE (op1), op0, tf_none);
3042 if (t != error_mark_node)
3044 pedwarn ("assuming cast to type %qT from overloaded function",
3049 if (type_unknown_p (op1))
3051 tree t = instantiate_type (TREE_TYPE (op0), op1, tf_none);
3052 if (t != error_mark_node)
3054 pedwarn ("assuming cast to type %qT from overloaded function",
3060 type0 = TREE_TYPE (op0);
3061 type1 = TREE_TYPE (op1);
3063 /* The expression codes of the data types of the arguments tell us
3064 whether the arguments are integers, floating, pointers, etc. */
3065 code0 = TREE_CODE (type0);
3066 code1 = TREE_CODE (type1);
3068 /* If an error was already reported for one of the arguments,
3069 avoid reporting another error. */
3071 if (code0 == ERROR_MARK || code1 == ERROR_MARK)
3072 return error_mark_node;
3074 if ((invalid_op_diag
3075 = targetm.invalid_binary_op (code, type0, type1)))
3077 error (invalid_op_diag);
3078 return error_mark_node;
3084 /* Subtraction of two similar pointers.
3085 We must subtract them as integers, then divide by object size. */
3086 if (code0 == POINTER_TYPE && code1 == POINTER_TYPE
3087 && same_type_ignoring_top_level_qualifiers_p (TREE_TYPE (type0),
3089 return pointer_diff (op0, op1, common_type (type0, type1));
3090 /* In all other cases except pointer - int, the usual arithmetic
3092 else if (!(code0 == POINTER_TYPE && code1 == INTEGER_TYPE))
3097 /* The pointer - int case is just like pointer + int; fall
3100 if ((code0 == POINTER_TYPE || code1 == POINTER_TYPE)
3101 && (code0 == INTEGER_TYPE || code1 == INTEGER_TYPE))
3105 ptr_operand = ((code0 == POINTER_TYPE) ? op0 : op1);
3106 int_operand = ((code0 == INTEGER_TYPE) ? op0 : op1);
3107 if (processing_template_decl)
3109 result_type = TREE_TYPE (ptr_operand);
3112 return cp_pointer_int_sum (code,
3123 case TRUNC_DIV_EXPR:
3125 case FLOOR_DIV_EXPR:
3126 case ROUND_DIV_EXPR:
3127 case EXACT_DIV_EXPR:
3128 if ((code0 == INTEGER_TYPE || code0 == REAL_TYPE
3129 || code0 == COMPLEX_TYPE || code0 == VECTOR_TYPE)
3130 && (code1 == INTEGER_TYPE || code1 == REAL_TYPE
3131 || code1 == COMPLEX_TYPE || code1 == VECTOR_TYPE))
3133 enum tree_code tcode0 = code0, tcode1 = code1;
3135 if (TREE_CODE (op1) == INTEGER_CST && integer_zerop (op1))
3136 warning (OPT_Wdiv_by_zero, "division by zero in %<%E / 0%>", op0);
3137 else if (TREE_CODE (op1) == REAL_CST && real_zerop (op1))
3138 warning (OPT_Wdiv_by_zero, "division by zero in %<%E / 0.%>", op0);
3140 if (tcode0 == COMPLEX_TYPE || tcode0 == VECTOR_TYPE)
3141 tcode0 = TREE_CODE (TREE_TYPE (TREE_TYPE (op0)));
3142 if (tcode1 == COMPLEX_TYPE || tcode1 == VECTOR_TYPE)
3143 tcode1 = TREE_CODE (TREE_TYPE (TREE_TYPE (op1)));
3145 if (!(tcode0 == INTEGER_TYPE && tcode1 == INTEGER_TYPE))
3146 resultcode = RDIV_EXPR;
3148 /* When dividing two signed integers, we have to promote to int.
3149 unless we divide by a constant != -1. Note that default
3150 conversion will have been performed on the operands at this
3151 point, so we have to dig out the original type to find out if
3153 shorten = ((TREE_CODE (op0) == NOP_EXPR
3154 && TYPE_UNSIGNED (TREE_TYPE (TREE_OPERAND (op0, 0))))
3155 || (TREE_CODE (op1) == INTEGER_CST
3156 && ! integer_all_onesp (op1)));
3165 if ((code0 == INTEGER_TYPE && code1 == INTEGER_TYPE)
3166 || (code0 == VECTOR_TYPE && code1 == VECTOR_TYPE))
3170 case TRUNC_MOD_EXPR:
3171 case FLOOR_MOD_EXPR:
3172 if (code1 == INTEGER_TYPE && integer_zerop (op1))
3173 warning (OPT_Wdiv_by_zero, "division by zero in %<%E %% 0%>", op0);
3174 else if (code1 == REAL_TYPE && real_zerop (op1))
3175 warning (OPT_Wdiv_by_zero, "division by zero in %<%E %% 0.%>", op0);
3177 if (code0 == INTEGER_TYPE && code1 == INTEGER_TYPE)
3179 /* Although it would be tempting to shorten always here, that loses
3180 on some targets, since the modulo instruction is undefined if the
3181 quotient can't be represented in the computation mode. We shorten
3182 only if unsigned or if dividing by something we know != -1. */
3183 shorten = ((TREE_CODE (op0) == NOP_EXPR
3184 && TYPE_UNSIGNED (TREE_TYPE (TREE_OPERAND (op0, 0))))
3185 || (TREE_CODE (op1) == INTEGER_CST
3186 && ! integer_all_onesp (op1)));
3191 case TRUTH_ANDIF_EXPR:
3192 case TRUTH_ORIF_EXPR:
3193 case TRUTH_AND_EXPR:
3195 result_type = boolean_type_node;
3198 /* Shift operations: result has same type as first operand;
3199 always convert second operand to int.
3200 Also set SHORT_SHIFT if shifting rightward. */
3203 if (code0 == INTEGER_TYPE && code1 == INTEGER_TYPE)
3205 result_type = type0;
3206 if (TREE_CODE (op1) == INTEGER_CST)
3208 if (tree_int_cst_lt (op1, integer_zero_node))
3209 warning (0, "right shift count is negative");
3212 if (! integer_zerop (op1))
3214 if (compare_tree_int (op1, TYPE_PRECISION (type0)) >= 0)
3215 warning (0, "right shift count >= width of type");
3218 /* Convert the shift-count to an integer, regardless of
3219 size of value being shifted. */
3220 if (TYPE_MAIN_VARIANT (TREE_TYPE (op1)) != integer_type_node)
3221 op1 = cp_convert (integer_type_node, op1);
3222 /* Avoid converting op1 to result_type later. */
3228 if (code0 == INTEGER_TYPE && code1 == INTEGER_TYPE)
3230 result_type = type0;
3231 if (TREE_CODE (op1) == INTEGER_CST)
3233 if (tree_int_cst_lt (op1, integer_zero_node))
3234 warning (0, "left shift count is negative");
3235 else if (compare_tree_int (op1, TYPE_PRECISION (type0)) >= 0)
3236 warning (0, "left shift count >= width of type");
3238 /* Convert the shift-count to an integer, regardless of
3239 size of value being shifted. */
3240 if (TYPE_MAIN_VARIANT (TREE_TYPE (op1)) != integer_type_node)
3241 op1 = cp_convert (integer_type_node, op1);
3242 /* Avoid converting op1 to result_type later. */
3249 if (code0 == INTEGER_TYPE && code1 == INTEGER_TYPE)
3251 result_type = type0;
3252 if (TREE_CODE (op1) == INTEGER_CST)
3254 if (tree_int_cst_lt (op1, integer_zero_node))
3255 warning (0, (code == LROTATE_EXPR)
3256 ? G_("left rotate count is negative")
3257 : G_("right rotate count is negative"));
3258 else if (compare_tree_int (op1, TYPE_PRECISION (type0)) >= 0)
3259 warning (0, (code == LROTATE_EXPR)
3260 ? G_("left rotate count >= width of type")
3261 : G_("right rotate count >= width of type"));
3263 /* Convert the shift-count to an integer, regardless of
3264 size of value being shifted. */
3265 if (TYPE_MAIN_VARIANT (TREE_TYPE (op1)) != integer_type_node)
3266 op1 = cp_convert (integer_type_node, op1);
3272 if (code0 == REAL_TYPE || code1 == REAL_TYPE)
3273 warning (OPT_Wfloat_equal,
3274 "comparing floating point with == or != is unsafe");
3275 if ((TREE_CODE (orig_op0) == STRING_CST && !integer_zerop (op1))
3276 || (TREE_CODE (orig_op1) == STRING_CST && !integer_zerop (op0)))
3277 warning (OPT_Waddress, "comparison with string literal results in unspecified behaviour");
3279 build_type = boolean_type_node;
3280 if ((code0 == INTEGER_TYPE || code0 == REAL_TYPE
3281 || code0 == COMPLEX_TYPE)
3282 && (code1 == INTEGER_TYPE || code1 == REAL_TYPE
3283 || code1 == COMPLEX_TYPE))
3285 else if ((code0 == POINTER_TYPE && code1 == POINTER_TYPE)
3286 || (TYPE_PTRMEM_P (type0) && TYPE_PTRMEM_P (type1)))
3287 result_type = composite_pointer_type (type0, type1, op0, op1,
3289 else if ((code0 == POINTER_TYPE || TYPE_PTRMEM_P (type0))
3290 && null_ptr_cst_p (op1))
3292 if (TREE_CODE (op0) == ADDR_EXPR
3293 && decl_with_nonnull_addr_p (TREE_OPERAND (op0, 0)))
3294 warning (OPT_Waddress, "the address of %qD will never be NULL",
3295 TREE_OPERAND (op0, 0));
3296 result_type = type0;
3298 else if ((code1 == POINTER_TYPE || TYPE_PTRMEM_P (type1))
3299 && null_ptr_cst_p (op0))
3301 if (TREE_CODE (op1) == ADDR_EXPR
3302 && decl_with_nonnull_addr_p (TREE_OPERAND (op1, 0)))
3303 warning (OPT_Waddress, "the address of %qD will never be NULL",
3304 TREE_OPERAND (op1, 0));
3305 result_type = type1;
3307 else if (code0 == POINTER_TYPE && code1 == INTEGER_TYPE)
3309 result_type = type0;
3310 error ("ISO C++ forbids comparison between pointer and integer");
3312 else if (code0 == INTEGER_TYPE && code1 == POINTER_TYPE)
3314 result_type = type1;
3315 error ("ISO C++ forbids comparison between pointer and integer");
3317 else if (TYPE_PTRMEMFUNC_P (type0) && null_ptr_cst_p (op1))
3319 if (TARGET_PTRMEMFUNC_VBIT_LOCATION
3320 == ptrmemfunc_vbit_in_delta)
3322 tree pfn0 = pfn_from_ptrmemfunc (op0);
3323 tree delta0 = build_ptrmemfunc_access_expr (op0,
3325 tree e1 = cp_build_binary_op (EQ_EXPR,
3327 fold_convert (TREE_TYPE (pfn0),
3328 integer_zero_node));
3329 tree e2 = cp_build_binary_op (BIT_AND_EXPR,
3332 e2 = cp_build_binary_op (EQ_EXPR, e2, integer_zero_node);
3333 op0 = cp_build_binary_op (TRUTH_ANDIF_EXPR, e1, e2);
3334 op1 = cp_convert (TREE_TYPE (op0), integer_one_node);
3338 op0 = build_ptrmemfunc_access_expr (op0, pfn_identifier);
3339 op1 = cp_convert (TREE_TYPE (op0), integer_zero_node);
3341 result_type = TREE_TYPE (op0);
3343 else if (TYPE_PTRMEMFUNC_P (type1) && null_ptr_cst_p (op0))
3344 return cp_build_binary_op (code, op1, op0);
3345 else if (TYPE_PTRMEMFUNC_P (type0) && TYPE_PTRMEMFUNC_P (type1)
3346 && same_type_p (type0, type1))
3348 /* E will be the final comparison. */
3350 /* E1 and E2 are for scratch. */
3358 if (TREE_SIDE_EFFECTS (op0))
3359 op0 = save_expr (op0);
3360 if (TREE_SIDE_EFFECTS (op1))
3361 op1 = save_expr (op1);
3363 pfn0 = pfn_from_ptrmemfunc (op0);
3364 pfn1 = pfn_from_ptrmemfunc (op1);
3365 delta0 = build_ptrmemfunc_access_expr (op0,
3367 delta1 = build_ptrmemfunc_access_expr (op1,
3369 if (TARGET_PTRMEMFUNC_VBIT_LOCATION
3370 == ptrmemfunc_vbit_in_delta)
3375 && ((op0.delta == op1.delta)
3376 || (!op0.pfn && op0.delta & 1 == 0
3377 && op1.delta & 1 == 0))
3379 The reason for the `!op0.pfn' bit is that a NULL
3380 pointer-to-member is any member with a zero PFN and
3381 LSB of the DELTA field is 0. */
3383 e1 = cp_build_binary_op (BIT_AND_EXPR,
3386 e1 = cp_build_binary_op (EQ_EXPR, e1, integer_zero_node);
3387 e2 = cp_build_binary_op (BIT_AND_EXPR,
3390 e2 = cp_build_binary_op (EQ_EXPR, e2, integer_zero_node);
3391 e1 = cp_build_binary_op (TRUTH_ANDIF_EXPR, e2, e1);
3392 e2 = cp_build_binary_op (EQ_EXPR,
3394 fold_convert (TREE_TYPE (pfn0),
3395 integer_zero_node));
3396 e2 = cp_build_binary_op (TRUTH_ANDIF_EXPR, e2, e1);
3397 e1 = cp_build_binary_op (EQ_EXPR, delta0, delta1);
3398 e1 = cp_build_binary_op (TRUTH_ORIF_EXPR, e1, e2);
3405 && (!op0.pfn || op0.delta == op1.delta))
3407 The reason for the `!op0.pfn' bit is that a NULL
3408 pointer-to-member is any member with a zero PFN; the
3409 DELTA field is unspecified. */
3411 e1 = cp_build_binary_op (EQ_EXPR, delta0, delta1);
3412 e2 = cp_build_binary_op (EQ_EXPR,
3414 fold_convert (TREE_TYPE (pfn0),
3415 integer_zero_node));
3416 e1 = cp_build_binary_op (TRUTH_ORIF_EXPR, e1, e2);
3418 e2 = build2 (EQ_EXPR, boolean_type_node, pfn0, pfn1);
3419 e = cp_build_binary_op (TRUTH_ANDIF_EXPR, e2, e1);
3420 if (code == EQ_EXPR)
3422 return cp_build_binary_op (EQ_EXPR, e, integer_zero_node);
3426 gcc_assert (!TYPE_PTRMEMFUNC_P (type0)
3427 || !same_type_p (TYPE_PTRMEMFUNC_FN_TYPE (type0),
3429 gcc_assert (!TYPE_PTRMEMFUNC_P (type1)
3430 || !same_type_p (TYPE_PTRMEMFUNC_FN_TYPE (type1),
3438 if ((code0 == INTEGER_TYPE || code0 == REAL_TYPE)
3439 && (code1 == INTEGER_TYPE || code1 == REAL_TYPE))
3441 else if (code0 == POINTER_TYPE && code1 == POINTER_TYPE)
3442 result_type = composite_pointer_type (type0, type1, op0, op1,
3450 if (TREE_CODE (orig_op0) == STRING_CST
3451 || TREE_CODE (orig_op1) == STRING_CST)
3452 warning (OPT_Waddress, "comparison with string literal results in unspecified behaviour");
3454 build_type = boolean_type_node;
3455 if ((code0 == INTEGER_TYPE || code0 == REAL_TYPE)
3456 && (code1 == INTEGER_TYPE || code1 == REAL_TYPE))
3458 else if (code0 == POINTER_TYPE && code1 == POINTER_TYPE)
3459 result_type = composite_pointer_type (type0, type1, op0, op1,
3461 else if (code0 == POINTER_TYPE && TREE_CODE (op1) == INTEGER_CST
3462 && integer_zerop (op1))
3463 result_type = type0;
3464 else if (code1 == POINTER_TYPE && TREE_CODE (op0) == INTEGER_CST
3465 && integer_zerop (op0))
3466 result_type = type1;
3467 else if (code0 == POINTER_TYPE && code1 == INTEGER_TYPE)
3469 result_type = type0;
3470 pedwarn ("ISO C++ forbids comparison between pointer and integer");
3472 else if (code0 == INTEGER_TYPE && code1 == POINTER_TYPE)
3474 result_type = type1;
3475 pedwarn ("ISO C++ forbids comparison between pointer and integer");
3479 case UNORDERED_EXPR:
3486 build_type = integer_type_node;
3487 if (code0 != REAL_TYPE || code1 != REAL_TYPE)
3489 error ("unordered comparison on non-floating point argument");
3490 return error_mark_node;
3499 if (((code0 == INTEGER_TYPE || code0 == REAL_TYPE || code0 == COMPLEX_TYPE)
3500 && (code1 == INTEGER_TYPE || code1 == REAL_TYPE
3501 || code1 == COMPLEX_TYPE)))
3502 arithmetic_types_p = 1;
3505 arithmetic_types_p = 0;
3506 /* Vector arithmetic is only allowed when both sides are vectors. */
3507 if (code0 == VECTOR_TYPE && code1 == VECTOR_TYPE)
3509 if (!tree_int_cst_equal (TYPE_SIZE (type0), TYPE_SIZE (type1))
3510 || !same_scalar_type_ignoring_signedness (TREE_TYPE (type0),
3513 binary_op_error (code);
3514 return error_mark_node;
3516 arithmetic_types_p = 1;
3519 /* Determine the RESULT_TYPE, if it is not already known. */
3521 && arithmetic_types_p
3522 && (shorten || common || short_compare))
3523 result_type = common_type (type0, type1);
3527 error ("invalid operands of types %qT and %qT to binary %qO",
3528 TREE_TYPE (orig_op0), TREE_TYPE (orig_op1), code);
3529 return error_mark_node;
3532 /* If we're in a template, the only thing we need to know is the
3534 if (processing_template_decl)
3535 return build2 (resultcode,
3536 build_type ? build_type : result_type,
3539 if (arithmetic_types_p)
3541 int none_complex = (code0 != COMPLEX_TYPE && code1 != COMPLEX_TYPE);
3543 /* For certain operations (which identify themselves by shorten != 0)
3544 if both args were extended from the same smaller type,
3545 do the arithmetic in that type and then extend.
3547 shorten !=0 and !=1 indicates a bitwise operation.
3548 For them, this optimization is safe only if
3549 both args are zero-extended or both are sign-extended.
3550 Otherwise, we might change the result.
3551 Eg, (short)-1 | (unsigned short)-1 is (int)-1
3552 but calculated in (unsigned short) it would be (unsigned short)-1. */
3554 if (shorten && none_complex)
3556 int unsigned0, unsigned1;
3557 tree arg0 = get_narrower (op0, &unsigned0);
3558 tree arg1 = get_narrower (op1, &unsigned1);
3559 /* UNS is 1 if the operation to be done is an unsigned one. */
3560 int uns = TYPE_UNSIGNED (result_type);
3563 final_type = result_type;
3565 /* Handle the case that OP0 does not *contain* a conversion
3566 but it *requires* conversion to FINAL_TYPE. */
3568 if (op0 == arg0 && TREE_TYPE (op0) != final_type)
3569 unsigned0 = TYPE_UNSIGNED (TREE_TYPE (op0));
3570 if (op1 == arg1 && TREE_TYPE (op1) != final_type)
3571 unsigned1 = TYPE_UNSIGNED (TREE_TYPE (op1));
3573 /* Now UNSIGNED0 is 1 if ARG0 zero-extends to FINAL_TYPE. */
3575 /* For bitwise operations, signedness of nominal type
3576 does not matter. Consider only how operands were extended. */
3580 /* Note that in all three cases below we refrain from optimizing
3581 an unsigned operation on sign-extended args.
3582 That would not be valid. */
3584 /* Both args variable: if both extended in same way
3585 from same width, do it in that width.
3586 Do it unsigned if args were zero-extended. */
3587 if ((TYPE_PRECISION (TREE_TYPE (arg0))
3588 < TYPE_PRECISION (result_type))
3589 && (TYPE_PRECISION (TREE_TYPE (arg1))
3590 == TYPE_PRECISION (TREE_TYPE (arg0)))
3591 && unsigned0 == unsigned1
3592 && (unsigned0 || !uns))
3593 result_type = c_common_signed_or_unsigned_type
3594 (unsigned0, common_type (TREE_TYPE (arg0), TREE_TYPE (arg1)));
3595 else if (TREE_CODE (arg0) == INTEGER_CST
3596 && (unsigned1 || !uns)
3597 && (TYPE_PRECISION (TREE_TYPE (arg1))
3598 < TYPE_PRECISION (result_type))
3599 && (type = c_common_signed_or_unsigned_type
3600 (unsigned1, TREE_TYPE (arg1)),
3601 int_fits_type_p (arg0, type)))
3603 else if (TREE_CODE (arg1) == INTEGER_CST
3604 && (unsigned0 || !uns)
3605 && (TYPE_PRECISION (TREE_TYPE (arg0))
3606 < TYPE_PRECISION (result_type))
3607 && (type = c_common_signed_or_unsigned_type
3608 (unsigned0, TREE_TYPE (arg0)),
3609 int_fits_type_p (arg1, type)))
3613 /* Shifts can be shortened if shifting right. */
3618 tree arg0 = get_narrower (op0, &unsigned_arg);
3620 final_type = result_type;
3622 if (arg0 == op0 && final_type == TREE_TYPE (op0))
3623 unsigned_arg = TYPE_UNSIGNED (TREE_TYPE (op0));
3625 if (TYPE_PRECISION (TREE_TYPE (arg0)) < TYPE_PRECISION (result_type)
3626 /* We can shorten only if the shift count is less than the
3627 number of bits in the smaller type size. */
3628 && compare_tree_int (op1, TYPE_PRECISION (TREE_TYPE (arg0))) < 0
3629 /* If arg is sign-extended and then unsigned-shifted,
3630 we can simulate this with a signed shift in arg's type
3631 only if the extended result is at least twice as wide
3632 as the arg. Otherwise, the shift could use up all the
3633 ones made by sign-extension and bring in zeros.
3634 We can't optimize that case at all, but in most machines
3635 it never happens because available widths are 2**N. */
3636 && (!TYPE_UNSIGNED (final_type)
3638 || (((unsigned) 2 * TYPE_PRECISION (TREE_TYPE (arg0)))
3639 <= TYPE_PRECISION (result_type))))
3641 /* Do an unsigned shift if the operand was zero-extended. */
3643 = c_common_signed_or_unsigned_type (unsigned_arg,
3645 /* Convert value-to-be-shifted to that type. */
3646 if (TREE_TYPE (op0) != result_type)
3647 op0 = cp_convert (result_type, op0);
3652 /* Comparison operations are shortened too but differently.
3653 They identify themselves by setting short_compare = 1. */
3657 /* Don't write &op0, etc., because that would prevent op0
3658 from being kept in a register.
3659 Instead, make copies of the our local variables and
3660 pass the copies by reference, then copy them back afterward. */
3661 tree xop0 = op0, xop1 = op1, xresult_type = result_type;
3662 enum tree_code xresultcode = resultcode;
3664 = shorten_compare (&xop0, &xop1, &xresult_type, &xresultcode);
3666 return cp_convert (boolean_type_node, val);
3667 op0 = xop0, op1 = xop1;
3669 resultcode = xresultcode;
3672 if ((short_compare || code == MIN_EXPR || code == MAX_EXPR)
3673 && warn_sign_compare
3674 /* Do not warn until the template is instantiated; we cannot
3675 bound the ranges of the arguments until that point. */
3676 && !processing_template_decl)
3678 int op0_signed = !TYPE_UNSIGNED (TREE_TYPE (orig_op0));
3679 int op1_signed = !TYPE_UNSIGNED (TREE_TYPE (orig_op1));
3681 int unsignedp0, unsignedp1;
3682 tree primop0 = get_narrower (op0, &unsignedp0);
3683 tree primop1 = get_narrower (op1, &unsignedp1);
3685 /* Check for comparison of different enum types. */
3686 if (TREE_CODE (TREE_TYPE (orig_op0)) == ENUMERAL_TYPE
3687 && TREE_CODE (TREE_TYPE (orig_op1)) == ENUMERAL_TYPE
3688 && TYPE_MAIN_VARIANT (TREE_TYPE (orig_op0))
3689 != TYPE_MAIN_VARIANT (TREE_TYPE (orig_op1)))
3691 warning (0, "comparison between types %q#T and %q#T",
3692 TREE_TYPE (orig_op0), TREE_TYPE (orig_op1));
3695 /* Give warnings for comparisons between signed and unsigned
3696 quantities that may fail. */
3697 /* Do the checking based on the original operand trees, so that
3698 casts will be considered, but default promotions won't be. */
3700 /* Do not warn if the comparison is being done in a signed type,
3701 since the signed type will only be chosen if it can represent
3702 all the values of the unsigned type. */
3703 if (!TYPE_UNSIGNED (result_type))
3705 /* Do not warn if both operands are unsigned. */
3706 else if (op0_signed == op1_signed)
3708 /* Do not warn if the signed quantity is an unsuffixed
3709 integer literal (or some static constant expression
3710 involving such literals or a conditional expression
3711 involving such literals) and it is non-negative. */
3712 else if ((op0_signed && tree_expr_nonnegative_p (orig_op0))
3713 || (op1_signed && tree_expr_nonnegative_p (orig_op1)))
3715 /* Do not warn if the comparison is an equality operation,
3716 the unsigned quantity is an integral constant and it does
3717 not use the most significant bit of result_type. */
3718 else if ((resultcode == EQ_EXPR || resultcode == NE_EXPR)
3719 && ((op0_signed && TREE_CODE (orig_op1) == INTEGER_CST
3720 && int_fits_type_p (orig_op1, c_common_signed_type
3722 || (op1_signed && TREE_CODE (orig_op0) == INTEGER_CST
3723 && int_fits_type_p (orig_op0, c_common_signed_type
3727 warning (0, "comparison between signed and unsigned integer expressions");
3729 /* Warn if two unsigned values are being compared in a size
3730 larger than their original size, and one (and only one) is the
3731 result of a `~' operator. This comparison will always fail.
3733 Also warn if one operand is a constant, and the constant does not
3734 have all bits set that are set in the ~ operand when it is
3737 if ((TREE_CODE (primop0) == BIT_NOT_EXPR)
3738 ^ (TREE_CODE (primop1) == BIT_NOT_EXPR))
3740 if (TREE_CODE (primop0) == BIT_NOT_EXPR)
3741 primop0 = get_narrower (TREE_OPERAND (op0, 0), &unsignedp0);
3742 if (TREE_CODE (primop1) == BIT_NOT_EXPR)
3743 primop1 = get_narrower (TREE_OPERAND (op1, 0), &unsignedp1);
3745 if (host_integerp (primop0, 0) || host_integerp (primop1, 0))
3748 HOST_WIDE_INT constant, mask;
3752 if (host_integerp (primop0, 0))
3755 unsignedp = unsignedp1;
3756 constant = tree_low_cst (primop0, 0);
3761 unsignedp = unsignedp0;
3762 constant = tree_low_cst (primop1, 0);
3765 bits = TYPE_PRECISION (TREE_TYPE (primop));
3766 if (bits < TYPE_PRECISION (result_type)
3767 && bits < HOST_BITS_PER_LONG && unsignedp)
3769 mask = (~ (HOST_WIDE_INT) 0) << bits;
3770 if ((mask & constant) != mask)
3771 warning (0, "comparison of promoted ~unsigned with constant");
3774 else if (unsignedp0 && unsignedp1
3775 && (TYPE_PRECISION (TREE_TYPE (primop0))
3776 < TYPE_PRECISION (result_type))
3777 && (TYPE_PRECISION (TREE_TYPE (primop1))
3778 < TYPE_PRECISION (result_type)))
3779 warning (0, "comparison of promoted ~unsigned with unsigned");
3784 /* Issue warnings about peculiar, but valid, uses of NULL. */
3785 if ((orig_op0 == null_node || orig_op1 == null_node)
3786 /* It's reasonable to use pointer values as operands of &&
3787 and ||, so NULL is no exception. */
3788 && code != TRUTH_ANDIF_EXPR && code != TRUTH_ORIF_EXPR
3789 && ( /* Both are NULL (or 0) and the operation was not a comparison. */
3790 (null_ptr_cst_p (orig_op0) && null_ptr_cst_p (orig_op1)
3791 && code != EQ_EXPR && code != NE_EXPR)
3792 /* Or if one of OP0 or OP1 is neither a pointer nor NULL. */
3793 || (!null_ptr_cst_p (orig_op0) && TREE_CODE (TREE_TYPE (op0)) != POINTER_TYPE)
3794 || (!null_ptr_cst_p (orig_op1) && TREE_CODE (TREE_TYPE (op1)) != POINTER_TYPE)))
3795 /* Some sort of arithmetic operation involving NULL was
3796 performed. Note that pointer-difference and pointer-addition
3797 have already been handled above, and so we don't end up here in
3799 warning (OPT_Wpointer_arith, "NULL used in arithmetic");
3802 /* If CONVERTED is zero, both args will be converted to type RESULT_TYPE.
3803 Then the expression will be built.
3804 It will be given type FINAL_TYPE if that is nonzero;
3805 otherwise, it will be given type RESULT_TYPE. */
3808 if (TREE_TYPE (op0) != result_type)
3809 op0 = cp_convert (result_type, op0);
3810 if (TREE_TYPE (op1) != result_type)
3811 op1 = cp_convert (result_type, op1);
3813 if (op0 == error_mark_node || op1 == error_mark_node)
3814 return error_mark_node;
3817 if (build_type == NULL_TREE)
3818 build_type = result_type;
3820 result = build2 (resultcode, build_type, op0, op1);
3821 result = fold_if_not_in_template (result);
3822 if (final_type != 0)
3823 result = cp_convert (final_type, result);
3825 if (TREE_OVERFLOW_P (result)
3826 && !TREE_OVERFLOW_P (op0)
3827 && !TREE_OVERFLOW_P (op1))
3828 overflow_warning (result);
3833 /* Return a tree for the sum or difference (RESULTCODE says which)
3834 of pointer PTROP and integer INTOP. */
3837 cp_pointer_int_sum (enum tree_code resultcode, tree ptrop, tree intop)
3839 tree res_type = TREE_TYPE (ptrop);
3841 /* pointer_int_sum() uses size_in_bytes() on the TREE_TYPE(res_type)
3842 in certain circumstance (when it's valid to do so). So we need
3843 to make sure it's complete. We don't need to check here, if we
3844 can actually complete it at all, as those checks will be done in
3845 pointer_int_sum() anyway. */
3846 complete_type (TREE_TYPE (res_type));
3848 return pointer_int_sum (resultcode, ptrop,
3849 fold_if_not_in_template (intop));
3852 /* Return a tree for the difference of pointers OP0 and OP1.
3853 The resulting tree has type int. */
3856 pointer_diff (tree op0, tree op1, tree ptrtype)
3859 tree restype = ptrdiff_type_node;
3860 tree target_type = TREE_TYPE (ptrtype);
3862 if (!complete_type_or_else (target_type, NULL_TREE))
3863 return error_mark_node;
3865 if (pedantic || warn_pointer_arith)
3867 if (TREE_CODE (target_type) == VOID_TYPE)
3868 pedwarn ("ISO C++ forbids using pointer of type %<void *%> in subtraction");
3869 if (TREE_CODE (target_type) == FUNCTION_TYPE)
3870 pedwarn ("ISO C++ forbids using pointer to a function in subtraction");
3871 if (TREE_CODE (target_type) == METHOD_TYPE)
3872 pedwarn ("ISO C++ forbids using pointer to a method in subtraction");
3875 /* First do the subtraction as integers;
3876 then drop through to build the divide operator. */
3878 op0 = cp_build_binary_op (MINUS_EXPR,
3879 cp_convert (restype, op0),
3880 cp_convert (restype, op1));
3882 /* This generates an error if op1 is a pointer to an incomplete type. */
3883 if (!COMPLETE_TYPE_P (TREE_TYPE (TREE_TYPE (op1))))
3884 error ("invalid use of a pointer to an incomplete type in pointer arithmetic");
3886 op1 = (TYPE_PTROB_P (ptrtype)
3887 ? size_in_bytes (target_type)
3888 : integer_one_node);
3890 /* Do the division. */
3892 result = build2 (EXACT_DIV_EXPR, restype, op0, cp_convert (restype, op1));
3893 return fold_if_not_in_template (result);
3896 /* Construct and perhaps optimize a tree representation
3897 for a unary operation. CODE, a tree_code, specifies the operation
3898 and XARG is the operand. */
3901 build_x_unary_op (enum tree_code code, tree xarg)
3903 tree orig_expr = xarg;
3907 if (processing_template_decl)
3909 if (type_dependent_expression_p (xarg))
3910 return build_min_nt (code, xarg, NULL_TREE);
3912 xarg = build_non_dependent_expr (xarg);
3917 /* [expr.unary.op] says:
3919 The address of an object of incomplete type can be taken.
3921 (And is just the ordinary address operator, not an overloaded
3922 "operator &".) However, if the type is a template
3923 specialization, we must complete the type at this point so that
3924 an overloaded "operator &" will be available if required. */
3925 if (code == ADDR_EXPR
3926 && TREE_CODE (xarg) != TEMPLATE_ID_EXPR
3927 && ((CLASS_TYPE_P (TREE_TYPE (xarg))
3928 && !COMPLETE_TYPE_P (complete_type (TREE_TYPE (xarg))))
3929 || (TREE_CODE (xarg) == OFFSET_REF)))
3930 /* Don't look for a function. */;
3932 exp = build_new_op (code, LOOKUP_NORMAL, xarg, NULL_TREE, NULL_TREE,
3933 /*overloaded_p=*/NULL);
3934 if (!exp && code == ADDR_EXPR)
3936 /* A pointer to member-function can be formed only by saying
3938 if (!flag_ms_extensions && TREE_CODE (TREE_TYPE (xarg)) == METHOD_TYPE
3939 && (TREE_CODE (xarg) != OFFSET_REF || !PTRMEM_OK_P (xarg)))
3941 if (TREE_CODE (xarg) != OFFSET_REF
3942 || !TYPE_P (TREE_OPERAND (xarg, 0)))
3944 error ("invalid use of %qE to form a pointer-to-member-function",
3946 if (TREE_CODE (xarg) != OFFSET_REF)
3947 inform (" a qualified-id is required");
3948 return error_mark_node;
3952 error ("parentheses around %qE cannot be used to form a"
3953 " pointer-to-member-function",
3955 PTRMEM_OK_P (xarg) = 1;
3959 if (TREE_CODE (xarg) == OFFSET_REF)
3961 ptrmem = PTRMEM_OK_P (xarg);
3963 if (!ptrmem && !flag_ms_extensions
3964 && TREE_CODE (TREE_TYPE (TREE_OPERAND (xarg, 1))) == METHOD_TYPE)
3966 /* A single non-static member, make sure we don't allow a
3967 pointer-to-member. */
3968 xarg = build2 (OFFSET_REF, TREE_TYPE (xarg),
3969 TREE_OPERAND (xarg, 0),
3970 ovl_cons (TREE_OPERAND (xarg, 1), NULL_TREE));
3971 PTRMEM_OK_P (xarg) = ptrmem;
3974 else if (TREE_CODE (xarg) == TARGET_EXPR)
3975 warning (0, "taking address of temporary");
3976 exp = build_unary_op (ADDR_EXPR, xarg, 0);
3979 if (processing_template_decl && exp != error_mark_node)
3980 exp = build_min_non_dep (code, exp, orig_expr,
3981 /*For {PRE,POST}{INC,DEC}REMENT_EXPR*/NULL_TREE);
3982 if (TREE_CODE (exp) == ADDR_EXPR)
3983 PTRMEM_OK_P (exp) = ptrmem;
3987 /* Like c_common_truthvalue_conversion, but handle pointer-to-member
3988 constants, where a null value is represented by an INTEGER_CST of
3992 cp_truthvalue_conversion (tree expr)
3994 tree type = TREE_TYPE (expr);
3995 if (TYPE_PTRMEM_P (type))
3996 return build_binary_op (NE_EXPR, expr, integer_zero_node, 1);
3998 return c_common_truthvalue_conversion (expr);
4001 /* Just like cp_truthvalue_conversion, but we want a CLEANUP_POINT_EXPR. */
4004 condition_conversion (tree expr)
4007 if (processing_template_decl)
4009 t = perform_implicit_conversion (boolean_type_node, expr);
4010 t = fold_build_cleanup_point_expr (boolean_type_node, t);
4014 /* Return an ADDR_EXPR giving the address of T. This function
4015 attempts no optimizations or simplifications; it is a low-level
4019 build_address (tree t)
4023 if (error_operand_p (t) || !cxx_mark_addressable (t))
4024 return error_mark_node;
4026 addr = build1 (ADDR_EXPR, build_pointer_type (TREE_TYPE (t)), t);
4031 /* Return a NOP_EXPR converting EXPR to TYPE. */
4034 build_nop (tree type, tree expr)
4036 if (type == error_mark_node || error_operand_p (expr))
4038 return build1 (NOP_EXPR, type, expr);
4041 /* C++: Must handle pointers to members.
4043 Perhaps type instantiation should be extended to handle conversion
4044 from aggregates to types we don't yet know we want? (Or are those
4045 cases typically errors which should be reported?)
4047 NOCONVERT nonzero suppresses the default promotions
4048 (such as from short to int). */
4051 build_unary_op (enum tree_code code, tree xarg, int noconvert)
4053 /* No default_conversion here. It causes trouble for ADDR_EXPR. */
4056 const char *errstring = NULL;
4058 const char *invalid_op_diag;
4060 if (arg == error_mark_node)
4061 return error_mark_node;
4063 if ((invalid_op_diag
4064 = targetm.invalid_unary_op ((code == UNARY_PLUS_EXPR
4069 error (invalid_op_diag);
4070 return error_mark_node;
4075 case UNARY_PLUS_EXPR:
4078 int flags = WANT_ARITH | WANT_ENUM;
4079 /* Unary plus (but not unary minus) is allowed on pointers. */
4080 if (code == UNARY_PLUS_EXPR)
4081 flags |= WANT_POINTER;
4082 arg = build_expr_type_conversion (flags, arg, true);
4084 errstring = (code == NEGATE_EXPR
4085 ? "wrong type argument to unary minus"
4086 : "wrong type argument to unary plus");
4089 if (!noconvert && CP_INTEGRAL_TYPE_P (TREE_TYPE (arg)))
4090 arg = perform_integral_promotions (arg);
4092 /* Make sure the result is not an lvalue: a unary plus or minus
4093 expression is always a rvalue. */
4100 if (TREE_CODE (TREE_TYPE (arg)) == COMPLEX_TYPE)
4104 arg = default_conversion (arg);
4106 else if (!(arg = build_expr_type_conversion (WANT_INT | WANT_ENUM
4109 errstring = "wrong type argument to bit-complement";
4110 else if (!noconvert && CP_INTEGRAL_TYPE_P (TREE_TYPE (arg)))
4111 arg = perform_integral_promotions (arg);
4115 if (!(arg = build_expr_type_conversion (WANT_ARITH | WANT_ENUM, arg, true)))
4116 errstring = "wrong type argument to abs";
4117 else if (!noconvert)
4118 arg = default_conversion (arg);
4122 /* Conjugating a real value is a no-op, but allow it anyway. */
4123 if (!(arg = build_expr_type_conversion (WANT_ARITH | WANT_ENUM, arg, true)))
4124 errstring = "wrong type argument to conjugation";
4125 else if (!noconvert)
4126 arg = default_conversion (arg);
4129 case TRUTH_NOT_EXPR:
4130 arg = perform_implicit_conversion (boolean_type_node, arg);
4131 val = invert_truthvalue (arg);
4132 if (arg != error_mark_node)
4134 errstring = "in argument to unary !";
4141 if (TREE_CODE (arg) == COMPLEX_CST)
4142 return TREE_REALPART (arg);
4143 else if (TREE_CODE (TREE_TYPE (arg)) == COMPLEX_TYPE)
4145 arg = build1 (REALPART_EXPR, TREE_TYPE (TREE_TYPE (arg)), arg);
4146 return fold_if_not_in_template (arg);
4152 if (TREE_CODE (arg) == COMPLEX_CST)
4153 return TREE_IMAGPART (arg);
4154 else if (TREE_CODE (TREE_TYPE (arg)) == COMPLEX_TYPE)
4156 arg = build1 (IMAGPART_EXPR, TREE_TYPE (TREE_TYPE (arg)), arg);
4157 return fold_if_not_in_template (arg);
4160 return cp_convert (TREE_TYPE (arg), integer_zero_node);
4162 case PREINCREMENT_EXPR:
4163 case POSTINCREMENT_EXPR:
4164 case PREDECREMENT_EXPR:
4165 case POSTDECREMENT_EXPR:
4166 /* Handle complex lvalues (when permitted)
4167 by reduction to simpler cases. */
4169 val = unary_complex_lvalue (code, arg);
4173 /* Increment or decrement the real part of the value,
4174 and don't change the imaginary part. */
4175 if (TREE_CODE (TREE_TYPE (arg)) == COMPLEX_TYPE)
4179 arg = stabilize_reference (arg);
4180 real = build_unary_op (REALPART_EXPR, arg, 1);
4181 imag = build_unary_op (IMAGPART_EXPR, arg, 1);
4182 return build2 (COMPLEX_EXPR, TREE_TYPE (arg),
4183 build_unary_op (code, real, 1), imag);
4186 /* Report invalid types. */
4188 if (!(arg = build_expr_type_conversion (WANT_ARITH | WANT_POINTER,
4191 if (code == PREINCREMENT_EXPR)
4192 errstring ="no pre-increment operator for type";
4193 else if (code == POSTINCREMENT_EXPR)
4194 errstring ="no post-increment operator for type";
4195 else if (code == PREDECREMENT_EXPR)
4196 errstring ="no pre-decrement operator for type";
4198 errstring ="no post-decrement operator for type";
4202 /* Report something read-only. */
4204 if (CP_TYPE_CONST_P (TREE_TYPE (arg))
4205 || TREE_READONLY (arg))
4206 readonly_error (arg, ((code == PREINCREMENT_EXPR
4207 || code == POSTINCREMENT_EXPR)
4208 ? "increment" : "decrement"));
4212 tree result_type = TREE_TYPE (arg);
4214 arg = get_unwidened (arg, 0);
4215 argtype = TREE_TYPE (arg);
4217 /* ARM $5.2.5 last annotation says this should be forbidden. */
4218 if (TREE_CODE (argtype) == ENUMERAL_TYPE)
4219 pedwarn ((code == PREINCREMENT_EXPR || code == POSTINCREMENT_EXPR)
4220 ? G_("ISO C++ forbids incrementing an enum")
4221 : G_("ISO C++ forbids decrementing an enum"));
4223 /* Compute the increment. */
4225 if (TREE_CODE (argtype) == POINTER_TYPE)
4227 tree type = complete_type (TREE_TYPE (argtype));
4229 if (!COMPLETE_OR_VOID_TYPE_P (type))
4230 error (((code == PREINCREMENT_EXPR
4231 || code == POSTINCREMENT_EXPR))
4232 ? G_("cannot increment a pointer to incomplete type %qT")
4233 : G_("cannot decrement a pointer to incomplete type %qT"),
4234 TREE_TYPE (argtype));
4235 else if ((pedantic || warn_pointer_arith)
4236 && !TYPE_PTROB_P (argtype))
4237 pedwarn ((code == PREINCREMENT_EXPR
4238 || code == POSTINCREMENT_EXPR)
4239 ? G_("ISO C++ forbids incrementing a pointer of type %qT")
4240 : G_("ISO C++ forbids decrementing a pointer of type %qT"),
4242 inc = cxx_sizeof_nowarn (TREE_TYPE (argtype));
4245 inc = integer_one_node;
4247 inc = cp_convert (argtype, inc);
4249 /* Handle incrementing a cast-expression. */
4251 switch (TREE_CODE (arg))
4256 case FIX_TRUNC_EXPR:
4258 tree incremented, modify, value, compound;
4259 if (! lvalue_p (arg) && pedantic)
4260 pedwarn ("cast to non-reference type used as lvalue");
4261 arg = stabilize_reference (arg);
4262 if (code == PREINCREMENT_EXPR || code == PREDECREMENT_EXPR)
4265 value = save_expr (arg);
4266 incremented = build2 (((code == PREINCREMENT_EXPR
4267 || code == POSTINCREMENT_EXPR)
4268 ? PLUS_EXPR : MINUS_EXPR),
4269 argtype, value, inc);
4271 modify = build_modify_expr (arg, NOP_EXPR, incremented);
4272 compound = build2 (COMPOUND_EXPR, TREE_TYPE (arg),
4275 /* Eliminate warning about unused result of + or -. */
4276 TREE_NO_WARNING (compound) = 1;
4284 /* Complain about anything else that is not a true lvalue. */
4285 if (!lvalue_or_else (arg, ((code == PREINCREMENT_EXPR
4286 || code == POSTINCREMENT_EXPR)
4287 ? lv_increment : lv_decrement)))
4288 return error_mark_node;
4290 /* Forbid using -- on `bool'. */
4291 if (same_type_p (TREE_TYPE (arg), boolean_type_node))
4293 if (code == POSTDECREMENT_EXPR || code == PREDECREMENT_EXPR)
4295 error ("invalid use of %<--%> on bool variable %qD", arg);
4296 return error_mark_node;
4298 val = boolean_increment (code, arg);
4301 val = build2 (code, TREE_TYPE (arg), arg, inc);
4303 TREE_SIDE_EFFECTS (val) = 1;
4304 return cp_convert (result_type, val);
4308 /* Note that this operation never does default_conversion
4309 regardless of NOCONVERT. */
4311 argtype = lvalue_type (arg);
4313 if (TREE_CODE (arg) == OFFSET_REF)
4316 if (TREE_CODE (argtype) == REFERENCE_TYPE)
4318 tree type = build_pointer_type (TREE_TYPE (argtype));
4319 arg = build1 (CONVERT_EXPR, type, arg);
4322 else if (pedantic && DECL_MAIN_P (arg))
4324 pedwarn ("ISO C++ forbids taking address of function %<::main%>");
4326 /* Let &* cancel out to simplify resulting code. */
4327 if (TREE_CODE (arg) == INDIRECT_REF)
4329 /* We don't need to have `current_class_ptr' wrapped in a
4330 NON_LVALUE_EXPR node. */
4331 if (arg == current_class_ref)
4332 return current_class_ptr;
4334 arg = TREE_OPERAND (arg, 0);
4335 if (TREE_CODE (TREE_TYPE (arg)) == REFERENCE_TYPE)
4337 tree type = build_pointer_type (TREE_TYPE (TREE_TYPE (arg)));
4338 arg = build1 (CONVERT_EXPR, type, arg);
4341 /* Don't let this be an lvalue. */
4346 /* Uninstantiated types are all functions. Taking the
4347 address of a function is a no-op, so just return the
4350 gcc_assert (TREE_CODE (arg) != IDENTIFIER_NODE
4351 || !IDENTIFIER_OPNAME_P (arg));
4353 if (TREE_CODE (arg) == COMPONENT_REF && type_unknown_p (arg)
4354 && !really_overloaded_fn (TREE_OPERAND (arg, 1)))
4356 /* They're trying to take the address of a unique non-static
4357 member function. This is ill-formed (except in MS-land),
4358 but let's try to DTRT.
4359 Note: We only handle unique functions here because we don't
4360 want to complain if there's a static overload; non-unique
4361 cases will be handled by instantiate_type. But we need to
4362 handle this case here to allow casts on the resulting PMF.
4363 We could defer this in non-MS mode, but it's easier to give
4364 a useful error here. */
4366 /* Inside constant member functions, the `this' pointer
4367 contains an extra const qualifier. TYPE_MAIN_VARIANT
4368 is used here to remove this const from the diagnostics
4369 and the created OFFSET_REF. */
4370 tree base = TYPE_MAIN_VARIANT (TREE_TYPE (TREE_OPERAND (arg, 0)));
4371 tree fn = get_first_fn (TREE_OPERAND (arg, 1));
4374 if (! flag_ms_extensions)
4376 tree name = DECL_NAME (fn);
4377 if (current_class_type
4378 && TREE_OPERAND (arg, 0) == current_class_ref)
4379 /* An expression like &memfn. */
4380 pedwarn ("ISO C++ forbids taking the address of an unqualified"
4381 " or parenthesized non-static member function to form"
4382 " a pointer to member function. Say %<&%T::%D%>",
4385 pedwarn ("ISO C++ forbids taking the address of a bound member"
4386 " function to form a pointer to member function."
4390 arg = build_offset_ref (base, fn, /*address_p=*/true);
4394 if (type_unknown_p (arg))
4395 return build1 (ADDR_EXPR, unknown_type_node, arg);
4397 /* Handle complex lvalues (when permitted)
4398 by reduction to simpler cases. */
4399 val = unary_complex_lvalue (code, arg);
4403 switch (TREE_CODE (arg))
4408 case FIX_TRUNC_EXPR:
4409 if (! lvalue_p (arg) && pedantic)
4410 pedwarn ("ISO C++ forbids taking the address of a cast to a non-lvalue expression");
4414 arg = BASELINK_FUNCTIONS (arg);
4418 arg = OVL_CURRENT (arg);
4422 /* Turn a reference to a non-static data member into a
4423 pointer-to-member. */
4428 if (!PTRMEM_OK_P (arg))
4429 return build_unary_op (code, arg, 0);
4431 t = TREE_OPERAND (arg, 1);
4432 if (TREE_CODE (TREE_TYPE (t)) == REFERENCE_TYPE)
4434 error ("cannot create pointer to reference member %qD", t);
4435 return error_mark_node;
4438 type = build_ptrmem_type (context_for_name_lookup (t),
4440 t = make_ptrmem_cst (type, TREE_OPERAND (arg, 1));
4448 /* Anything not already handled and not a true memory reference
4450 if (TREE_CODE (argtype) != FUNCTION_TYPE
4451 && TREE_CODE (argtype) != METHOD_TYPE
4452 && TREE_CODE (arg) != OFFSET_REF
4453 && !lvalue_or_else (arg, lv_addressof))
4454 return error_mark_node;
4456 if (argtype != error_mark_node)
4457 argtype = build_pointer_type (argtype);
4459 /* In a template, we are processing a non-dependent expression
4460 so we can just form an ADDR_EXPR with the correct type. */
4461 if (processing_template_decl)
4463 val = build_address (arg);
4464 if (TREE_CODE (arg) == OFFSET_REF)
4465 PTRMEM_OK_P (val) = PTRMEM_OK_P (arg);
4469 if (TREE_CODE (arg) != COMPONENT_REF)
4471 val = build_address (arg);
4472 if (TREE_CODE (arg) == OFFSET_REF)
4473 PTRMEM_OK_P (val) = PTRMEM_OK_P (arg);
4475 else if (TREE_CODE (TREE_OPERAND (arg, 1)) == BASELINK)
4477 tree fn = BASELINK_FUNCTIONS (TREE_OPERAND (arg, 1));
4479 /* We can only get here with a single static member
4481 gcc_assert (TREE_CODE (fn) == FUNCTION_DECL
4482 && DECL_STATIC_FUNCTION_P (fn));
4484 val = build_address (fn);
4485 if (TREE_SIDE_EFFECTS (TREE_OPERAND (arg, 0)))
4486 /* Do not lose object's side effects. */
4487 val = build2 (COMPOUND_EXPR, TREE_TYPE (val),
4488 TREE_OPERAND (arg, 0), val);
4490 else if (DECL_C_BIT_FIELD (TREE_OPERAND (arg, 1)))
4492 error ("attempt to take address of bit-field structure member %qD",
4493 TREE_OPERAND (arg, 1));
4494 return error_mark_node;
4498 tree object = TREE_OPERAND (arg, 0);
4499 tree field = TREE_OPERAND (arg, 1);
4500 gcc_assert (same_type_ignoring_top_level_qualifiers_p
4501 (TREE_TYPE (object), decl_type_context (field)));
4502 val = build_address (arg);
4505 if (TREE_CODE (argtype) == POINTER_TYPE
4506 && TREE_CODE (TREE_TYPE (argtype)) == METHOD_TYPE)
4508 build_ptrmemfunc_type (argtype);
4509 val = build_ptrmemfunc (argtype, val, 0,
4510 /*c_cast_p=*/false);
4522 argtype = TREE_TYPE (arg);
4523 return fold_if_not_in_template (build1 (code, argtype, arg));
4526 error ("%s", errstring);
4527 return error_mark_node;
4530 /* Apply unary lvalue-demanding operator CODE to the expression ARG
4531 for certain kinds of expressions which are not really lvalues
4532 but which we can accept as lvalues.
4534 If ARG is not a kind of expression we can handle, return
4538 unary_complex_lvalue (enum tree_code code, tree arg)
4540 /* Inside a template, making these kinds of adjustments is
4541 pointless; we are only concerned with the type of the
4543 if (processing_template_decl)
4546 /* Handle (a, b) used as an "lvalue". */
4547 if (TREE_CODE (arg) == COMPOUND_EXPR)
4549 tree real_result = build_unary_op (code, TREE_OPERAND (arg, 1), 0);
4550 return build2 (COMPOUND_EXPR, TREE_TYPE (real_result),
4551 TREE_OPERAND (arg, 0), real_result);
4554 /* Handle (a ? b : c) used as an "lvalue". */
4555 if (TREE_CODE (arg) == COND_EXPR
4556 || TREE_CODE (arg) == MIN_EXPR || TREE_CODE (arg) == MAX_EXPR)
4557 return rationalize_conditional_expr (code, arg);
4559 /* Handle (a = b), (++a), and (--a) used as an "lvalue". */
4560 if (TREE_CODE (arg) == MODIFY_EXPR
4561 || TREE_CODE (arg) == PREINCREMENT_EXPR
4562 || TREE_CODE (arg) == PREDECREMENT_EXPR)
4564 tree lvalue = TREE_OPERAND (arg, 0);
4565 if (TREE_SIDE_EFFECTS (lvalue))
4567 lvalue = stabilize_reference (lvalue);
4568 arg = build2 (TREE_CODE (arg), TREE_TYPE (arg),
4569 lvalue, TREE_OPERAND (arg, 1));
4571 return unary_complex_lvalue
4572 (code, build2 (COMPOUND_EXPR, TREE_TYPE (lvalue), arg, lvalue));
4575 if (code != ADDR_EXPR)
4578 /* Handle (a = b) used as an "lvalue" for `&'. */
4579 if (TREE_CODE (arg) == MODIFY_EXPR
4580 || TREE_CODE (arg) == INIT_EXPR)
4582 tree real_result = build_unary_op (code, TREE_OPERAND (arg, 0), 0);
4583 arg = build2 (COMPOUND_EXPR, TREE_TYPE (real_result),
4585 TREE_NO_WARNING (arg) = 1;
4589 if (TREE_CODE (TREE_TYPE (arg)) == FUNCTION_TYPE
4590 || TREE_CODE (TREE_TYPE (arg)) == METHOD_TYPE
4591 || TREE_CODE (arg) == OFFSET_REF)
4594 /* We permit compiler to make function calls returning
4595 objects of aggregate type look like lvalues. */
4599 if (TREE_CODE (targ) == SAVE_EXPR)
4600 targ = TREE_OPERAND (targ, 0);
4602 if (TREE_CODE (targ) == CALL_EXPR && IS_AGGR_TYPE (TREE_TYPE (targ)))
4604 if (TREE_CODE (arg) == SAVE_EXPR)
4607 targ = build_cplus_new (TREE_TYPE (arg), arg);
4608 return build1 (ADDR_EXPR, build_pointer_type (TREE_TYPE (arg)), targ);
4611 if (TREE_CODE (arg) == SAVE_EXPR && TREE_CODE (targ) == INDIRECT_REF)
4612 return build3 (SAVE_EXPR, build_pointer_type (TREE_TYPE (arg)),
4613 TREE_OPERAND (targ, 0), current_function_decl, NULL);
4616 /* Don't let anything else be handled specially. */
4620 /* Mark EXP saying that we need to be able to take the
4621 address of it; it should not be allocated in a register.
4622 Value is true if successful.
4624 C++: we do not allow `current_class_ptr' to be addressable. */
4627 cxx_mark_addressable (tree exp)
4632 switch (TREE_CODE (x))
4639 x = TREE_OPERAND (x, 0);
4643 if (x == current_class_ptr)
4645 error ("cannot take the address of %<this%>, which is an rvalue expression");
4646 TREE_ADDRESSABLE (x) = 1; /* so compiler doesn't die later. */
4652 /* Caller should not be trying to mark initialized
4653 constant fields addressable. */
4654 gcc_assert (DECL_LANG_SPECIFIC (x) == 0
4655 || DECL_IN_AGGR_P (x) == 0
4657 || DECL_EXTERNAL (x));
4662 if (DECL_REGISTER (x) && !TREE_ADDRESSABLE (x)
4663 && !DECL_ARTIFICIAL (x))
4665 if (TREE_CODE (x) == VAR_DECL && DECL_HARD_REGISTER (x))
4668 ("address of explicit register variable %qD requested", x);
4671 else if (extra_warnings)
4673 (OPT_Wextra, "address requested for %qD, which is declared %<register%>", x);
4675 TREE_ADDRESSABLE (x) = 1;
4679 TREE_ADDRESSABLE (x) = 1;
4683 TREE_ADDRESSABLE (x) = 1;
4687 TREE_ADDRESSABLE (x) = 1;
4688 cxx_mark_addressable (TREE_OPERAND (x, 0));
4696 /* Build and return a conditional expression IFEXP ? OP1 : OP2. */
4699 build_x_conditional_expr (tree ifexp, tree op1, tree op2)
4701 tree orig_ifexp = ifexp;
4702 tree orig_op1 = op1;
4703 tree orig_op2 = op2;
4706 if (processing_template_decl)
4708 /* The standard says that the expression is type-dependent if
4709 IFEXP is type-dependent, even though the eventual type of the
4710 expression doesn't dependent on IFEXP. */
4711 if (type_dependent_expression_p (ifexp)
4712 /* As a GNU extension, the middle operand may be omitted. */
4713 || (op1 && type_dependent_expression_p (op1))
4714 || type_dependent_expression_p (op2))
4715 return build_min_nt (COND_EXPR, ifexp, op1, op2);
4716 ifexp = build_non_dependent_expr (ifexp);
4718 op1 = build_non_dependent_expr (op1);
4719 op2 = build_non_dependent_expr (op2);
4722 expr = build_conditional_expr (ifexp, op1, op2);
4723 if (processing_template_decl && expr != error_mark_node)
4724 return build_min_non_dep (COND_EXPR, expr,
4725 orig_ifexp, orig_op1, orig_op2);
4729 /* Given a list of expressions, return a compound expression
4730 that performs them all and returns the value of the last of them. */
4732 tree build_x_compound_expr_from_list (tree list, const char *msg)
4734 tree expr = TREE_VALUE (list);
4736 if (TREE_CHAIN (list))
4739 pedwarn ("%s expression list treated as compound expression", msg);
4741 for (list = TREE_CHAIN (list); list; list = TREE_CHAIN (list))
4742 expr = build_x_compound_expr (expr, TREE_VALUE (list));
4748 /* Handle overloading of the ',' operator when needed. */
4751 build_x_compound_expr (tree op1, tree op2)
4754 tree orig_op1 = op1;
4755 tree orig_op2 = op2;
4757 if (processing_template_decl)
4759 if (type_dependent_expression_p (op1)
4760 || type_dependent_expression_p (op2))
4761 return build_min_nt (COMPOUND_EXPR, op1, op2);
4762 op1 = build_non_dependent_expr (op1);
4763 op2 = build_non_dependent_expr (op2);
4766 result = build_new_op (COMPOUND_EXPR, LOOKUP_NORMAL, op1, op2, NULL_TREE,
4767 /*overloaded_p=*/NULL);
4769 result = build_compound_expr (op1, op2);
4771 if (processing_template_decl && result != error_mark_node)
4772 return build_min_non_dep (COMPOUND_EXPR, result, orig_op1, orig_op2);
4777 /* Build a compound expression. */
4780 build_compound_expr (tree lhs, tree rhs)
4782 lhs = convert_to_void (lhs, "left-hand operand of comma");
4784 if (lhs == error_mark_node || rhs == error_mark_node)
4785 return error_mark_node;
4787 if (TREE_CODE (rhs) == TARGET_EXPR)
4789 /* If the rhs is a TARGET_EXPR, then build the compound
4790 expression inside the target_expr's initializer. This
4791 helps the compiler to eliminate unnecessary temporaries. */
4792 tree init = TREE_OPERAND (rhs, 1);
4794 init = build2 (COMPOUND_EXPR, TREE_TYPE (init), lhs, init);
4795 TREE_OPERAND (rhs, 1) = init;
4800 return build2 (COMPOUND_EXPR, TREE_TYPE (rhs), lhs, rhs);
4803 /* Issue a diagnostic message if casting from SRC_TYPE to DEST_TYPE
4804 casts away constness. DIAG_FN gives the function to call if we
4805 need to issue a diagnostic; if it is NULL, no diagnostic will be
4806 issued. DESCRIPTION explains what operation is taking place. */
4809 check_for_casting_away_constness (tree src_type, tree dest_type,
4810 void (*diag_fn)(const char *, ...) ATTRIBUTE_GCC_CXXDIAG(1,2),
4811 const char *description)
4813 if (diag_fn && casts_away_constness (src_type, dest_type))
4814 diag_fn ("%s from type %qT to type %qT casts away constness",
4815 description, src_type, dest_type);
4818 /* Convert EXPR (an expression with pointer-to-member type) to TYPE
4819 (another pointer-to-member type in the same hierarchy) and return
4820 the converted expression. If ALLOW_INVERSE_P is permitted, a
4821 pointer-to-derived may be converted to pointer-to-base; otherwise,
4822 only the other direction is permitted. If C_CAST_P is true, this
4823 conversion is taking place as part of a C-style cast. */
4826 convert_ptrmem (tree type, tree expr, bool allow_inverse_p,
4829 if (TYPE_PTRMEM_P (type))
4833 if (TREE_CODE (expr) == PTRMEM_CST)
4834 expr = cplus_expand_constant (expr);
4835 delta = get_delta_difference (TYPE_PTRMEM_CLASS_TYPE (TREE_TYPE (expr)),
4836 TYPE_PTRMEM_CLASS_TYPE (type),
4839 if (!integer_zerop (delta))
4840 expr = cp_build_binary_op (PLUS_EXPR,
4841 build_nop (ptrdiff_type_node, expr),
4843 return build_nop (type, expr);
4846 return build_ptrmemfunc (TYPE_PTRMEMFUNC_FN_TYPE (type), expr,
4847 allow_inverse_p, c_cast_p);
4850 /* If EXPR is an INTEGER_CST and ORIG is an arithmetic constant, return
4851 a version of EXPR that has TREE_OVERFLOW set if it is set in ORIG.
4852 Otherwise, return EXPR unchanged. */
4855 ignore_overflows (tree expr, tree orig)
4857 if (TREE_CODE (expr) == INTEGER_CST
4858 && CONSTANT_CLASS_P (orig)
4859 && TREE_CODE (orig) != STRING_CST
4860 && TREE_OVERFLOW (expr) != TREE_OVERFLOW (orig))
4862 if (!TREE_OVERFLOW (orig))
4863 /* Ensure constant sharing. */
4864 expr = build_int_cst_wide (TREE_TYPE (expr),
4865 TREE_INT_CST_LOW (expr),
4866 TREE_INT_CST_HIGH (expr));
4869 /* Avoid clobbering a shared constant. */
4870 expr = copy_node (expr);
4871 TREE_OVERFLOW (expr) = TREE_OVERFLOW (orig);
4877 /* Perform a static_cast from EXPR to TYPE. When C_CAST_P is true,
4878 this static_cast is being attempted as one of the possible casts
4879 allowed by a C-style cast. (In that case, accessibility of base
4880 classes is not considered, and it is OK to cast away
4881 constness.) Return the result of the cast. *VALID_P is set to
4882 indicate whether or not the cast was valid. */
4885 build_static_cast_1 (tree type, tree expr, bool c_cast_p,
4891 void (*diag_fn)(const char*, ...) ATTRIBUTE_GCC_CXXDIAG(1,2);
4894 /* Assume the cast is valid. */
4897 intype = TREE_TYPE (expr);
4899 /* Save casted types in the function's used types hash table. */
4900 used_types_insert (type);
4902 /* Determine what to do when casting away constness. */
4905 /* C-style casts are allowed to cast away constness. With
4906 WARN_CAST_QUAL, we still want to issue a warning. */
4907 diag_fn = warn_cast_qual ? warning0 : NULL;
4912 /* A static_cast may not cast away constness. */
4914 desc = "static_cast";
4917 /* [expr.static.cast]
4919 An lvalue of type "cv1 B", where B is a class type, can be cast
4920 to type "reference to cv2 D", where D is a class derived (clause
4921 _class.derived_) from B, if a valid standard conversion from
4922 "pointer to D" to "pointer to B" exists (_conv.ptr_), cv2 is the
4923 same cv-qualification as, or greater cv-qualification than, cv1,
4924 and B is not a virtual base class of D. */
4925 /* We check this case before checking the validity of "TYPE t =
4926 EXPR;" below because for this case:
4929 struct D : public B { D(const B&); };
4931 void f() { static_cast<const D&>(b); }
4933 we want to avoid constructing a new D. The standard is not
4934 completely clear about this issue, but our interpretation is
4935 consistent with other compilers. */
4936 if (TREE_CODE (type) == REFERENCE_TYPE
4937 && CLASS_TYPE_P (TREE_TYPE (type))
4938 && CLASS_TYPE_P (intype)
4939 && real_lvalue_p (expr)
4940 && DERIVED_FROM_P (intype, TREE_TYPE (type))
4941 && can_convert (build_pointer_type (TYPE_MAIN_VARIANT (intype)),
4942 build_pointer_type (TYPE_MAIN_VARIANT
4943 (TREE_TYPE (type))))
4945 || at_least_as_qualified_p (TREE_TYPE (type), intype)))
4949 /* There is a standard conversion from "D*" to "B*" even if "B"
4950 is ambiguous or inaccessible. If this is really a
4951 static_cast, then we check both for inaccessibility and
4952 ambiguity. However, if this is a static_cast being performed
4953 because the user wrote a C-style cast, then accessibility is
4955 base = lookup_base (TREE_TYPE (type), intype,
4956 c_cast_p ? ba_unique : ba_check,
4959 /* Convert from "B*" to "D*". This function will check that "B"
4960 is not a virtual base of "D". */
4961 expr = build_base_path (MINUS_EXPR, build_address (expr),
4962 base, /*nonnull=*/false);
4963 /* Convert the pointer to a reference -- but then remember that
4964 there are no expressions with reference type in C++. */
4965 return convert_from_reference (build_nop (type, expr));
4970 /* [expr.static.cast]
4972 An expression e can be explicitly converted to a type T using a
4973 static_cast of the form static_cast<T>(e) if the declaration T
4974 t(e);" is well-formed, for some invented temporary variable
4976 result = perform_direct_initialization_if_possible (type, expr,
4980 result = convert_from_reference (result);
4982 /* Ignore any integer overflow caused by the cast. */
4983 result = ignore_overflows (result, orig);
4985 /* [expr.static.cast]
4987 If T is a reference type, the result is an lvalue; otherwise,
4988 the result is an rvalue. */
4989 if (TREE_CODE (type) != REFERENCE_TYPE)
4990 result = rvalue (result);
4994 /* [expr.static.cast]
4996 Any expression can be explicitly converted to type cv void. */
4997 if (TREE_CODE (type) == VOID_TYPE)
4998 return convert_to_void (expr, /*implicit=*/NULL);
5000 /* [expr.static.cast]
5002 The inverse of any standard conversion sequence (clause _conv_),
5003 other than the lvalue-to-rvalue (_conv.lval_), array-to-pointer
5004 (_conv.array_), function-to-pointer (_conv.func_), and boolean
5005 (_conv.bool_) conversions, can be performed explicitly using
5006 static_cast subject to the restriction that the explicit
5007 conversion does not cast away constness (_expr.const.cast_), and
5008 the following additional rules for specific cases: */
5009 /* For reference, the conversions not excluded are: integral
5010 promotions, floating point promotion, integral conversions,
5011 floating point conversions, floating-integral conversions,
5012 pointer conversions, and pointer to member conversions. */
5015 A value of integral _or enumeration_ type can be explicitly
5016 converted to an enumeration type. */
5017 /* The effect of all that is that any conversion between any two
5018 types which are integral, floating, or enumeration types can be
5020 if ((INTEGRAL_TYPE_P (type) || SCALAR_FLOAT_TYPE_P (type))
5021 && (INTEGRAL_TYPE_P (intype) || SCALAR_FLOAT_TYPE_P (intype)))
5023 expr = ocp_convert (type, expr, CONV_C_CAST, LOOKUP_NORMAL);
5025 /* Ignore any integer overflow caused by the cast. */
5026 expr = ignore_overflows (expr, orig);
5030 if (TYPE_PTR_P (type) && TYPE_PTR_P (intype)
5031 && CLASS_TYPE_P (TREE_TYPE (type))
5032 && CLASS_TYPE_P (TREE_TYPE (intype))
5033 && can_convert (build_pointer_type (TYPE_MAIN_VARIANT
5034 (TREE_TYPE (intype))),
5035 build_pointer_type (TYPE_MAIN_VARIANT
5036 (TREE_TYPE (type)))))
5041 check_for_casting_away_constness (intype, type, diag_fn, desc);
5042 base = lookup_base (TREE_TYPE (type), TREE_TYPE (intype),
5043 c_cast_p ? ba_unique : ba_check,
5045 return build_base_path (MINUS_EXPR, expr, base, /*nonnull=*/false);
5048 if ((TYPE_PTRMEM_P (type) && TYPE_PTRMEM_P (intype))
5049 || (TYPE_PTRMEMFUNC_P (type) && TYPE_PTRMEMFUNC_P (intype)))
5056 c1 = TYPE_PTRMEM_CLASS_TYPE (intype);
5057 c2 = TYPE_PTRMEM_CLASS_TYPE (type);
5059 if (TYPE_PTRMEM_P (type))
5061 t1 = (build_ptrmem_type
5063 TYPE_MAIN_VARIANT (TYPE_PTRMEM_POINTED_TO_TYPE (intype))));
5064 t2 = (build_ptrmem_type
5066 TYPE_MAIN_VARIANT (TYPE_PTRMEM_POINTED_TO_TYPE (type))));
5073 if (can_convert (t1, t2))
5076 check_for_casting_away_constness (intype, type, diag_fn,
5078 return convert_ptrmem (type, expr, /*allow_inverse_p=*/1,
5083 /* [expr.static.cast]
5085 An rvalue of type "pointer to cv void" can be explicitly
5086 converted to a pointer to object type. A value of type pointer
5087 to object converted to "pointer to cv void" and back to the
5088 original pointer type will have its original value. */
5089 if (TREE_CODE (intype) == POINTER_TYPE
5090 && VOID_TYPE_P (TREE_TYPE (intype))
5091 && TYPE_PTROB_P (type))
5094 check_for_casting_away_constness (intype, type, diag_fn, desc);
5095 return build_nop (type, expr);
5099 return error_mark_node;
5102 /* Return an expression representing static_cast<TYPE>(EXPR). */
5105 build_static_cast (tree type, tree expr)
5110 if (type == error_mark_node || expr == error_mark_node)
5111 return error_mark_node;
5113 if (processing_template_decl)
5115 expr = build_min (STATIC_CAST_EXPR, type, expr);
5116 /* We don't know if it will or will not have side effects. */
5117 TREE_SIDE_EFFECTS (expr) = 1;
5118 return convert_from_reference (expr);
5121 /* build_c_cast puts on a NOP_EXPR to make the result not an lvalue.
5122 Strip such NOP_EXPRs if VALUE is being used in non-lvalue context. */
5123 if (TREE_CODE (type) != REFERENCE_TYPE
5124 && TREE_CODE (expr) == NOP_EXPR
5125 && TREE_TYPE (expr) == TREE_TYPE (TREE_OPERAND (expr, 0)))
5126 expr = TREE_OPERAND (expr, 0);
5128 result = build_static_cast_1 (type, expr, /*c_cast_p=*/false, &valid_p);
5132 error ("invalid static_cast from type %qT to type %qT",
5133 TREE_TYPE (expr), type);
5134 return error_mark_node;
5137 /* EXPR is an expression with member function or pointer-to-member
5138 function type. TYPE is a pointer type. Converting EXPR to TYPE is
5139 not permitted by ISO C++, but we accept it in some modes. If we
5140 are not in one of those modes, issue a diagnostic. Return the
5141 converted expression. */
5144 convert_member_func_to_ptr (tree type, tree expr)
5149 intype = TREE_TYPE (expr);
5150 gcc_assert (TYPE_PTRMEMFUNC_P (intype)
5151 || TREE_CODE (intype) == METHOD_TYPE);
5153 if (pedantic || warn_pmf2ptr)
5154 pedwarn ("converting from %qT to %qT", intype, type);
5156 if (TREE_CODE (intype) == METHOD_TYPE)
5157 expr = build_addr_func (expr);
5158 else if (TREE_CODE (expr) == PTRMEM_CST)
5159 expr = build_address (PTRMEM_CST_MEMBER (expr));
5162 decl = maybe_dummy_object (TYPE_PTRMEM_CLASS_TYPE (intype), 0);
5163 decl = build_address (decl);
5164 expr = get_member_function_from_ptrfunc (&decl, expr);
5167 return build_nop (type, expr);
5170 /* Return a representation for a reinterpret_cast from EXPR to TYPE.
5171 If C_CAST_P is true, this reinterpret cast is being done as part of
5172 a C-style cast. If VALID_P is non-NULL, *VALID_P is set to
5173 indicate whether or not reinterpret_cast was valid. */
5176 build_reinterpret_cast_1 (tree type, tree expr, bool c_cast_p,
5181 /* Assume the cast is invalid. */
5185 if (type == error_mark_node || error_operand_p (expr))
5186 return error_mark_node;
5188 intype = TREE_TYPE (expr);
5190 /* Save casted types in the function's used types hash table. */
5191 used_types_insert (type);
5193 /* [expr.reinterpret.cast]
5194 An lvalue expression of type T1 can be cast to the type
5195 "reference to T2" if an expression of type "pointer to T1" can be
5196 explicitly converted to the type "pointer to T2" using a
5197 reinterpret_cast. */
5198 if (TREE_CODE (type) == REFERENCE_TYPE)
5200 if (! real_lvalue_p (expr))
5202 error ("invalid cast of an rvalue expression of type "
5205 return error_mark_node;
5208 /* Warn about a reinterpret_cast from "A*" to "B&" if "A" and
5209 "B" are related class types; the reinterpret_cast does not
5210 adjust the pointer. */
5211 if (TYPE_PTR_P (intype)
5212 && (comptypes (TREE_TYPE (intype), TREE_TYPE (type),
5213 COMPARE_BASE | COMPARE_DERIVED)))
5214 warning (0, "casting %qT to %qT does not dereference pointer",
5217 expr = build_unary_op (ADDR_EXPR, expr, 0);
5218 if (expr != error_mark_node)
5219 expr = build_reinterpret_cast_1
5220 (build_pointer_type (TREE_TYPE (type)), expr, c_cast_p,
5222 if (expr != error_mark_node)
5223 expr = build_indirect_ref (expr, 0);
5227 /* As a G++ extension, we consider conversions from member
5228 functions, and pointers to member functions to
5229 pointer-to-function and pointer-to-void types. If
5230 -Wno-pmf-conversions has not been specified,
5231 convert_member_func_to_ptr will issue an error message. */
5232 if ((TYPE_PTRMEMFUNC_P (intype)
5233 || TREE_CODE (intype) == METHOD_TYPE)
5234 && TYPE_PTR_P (type)
5235 && (TREE_CODE (TREE_TYPE (type)) == FUNCTION_TYPE
5236 || VOID_TYPE_P (TREE_TYPE (type))))
5237 return convert_member_func_to_ptr (type, expr);
5239 /* If the cast is not to a reference type, the lvalue-to-rvalue,
5240 array-to-pointer, and function-to-pointer conversions are
5242 expr = decay_conversion (expr);
5244 /* build_c_cast puts on a NOP_EXPR to make the result not an lvalue.
5245 Strip such NOP_EXPRs if VALUE is being used in non-lvalue context. */
5246 if (TREE_CODE (expr) == NOP_EXPR
5247 && TREE_TYPE (expr) == TREE_TYPE (TREE_OPERAND (expr, 0)))
5248 expr = TREE_OPERAND (expr, 0);
5250 if (error_operand_p (expr))
5251 return error_mark_node;
5253 intype = TREE_TYPE (expr);
5255 /* [expr.reinterpret.cast]
5256 A pointer can be converted to any integral type large enough to
5258 if (CP_INTEGRAL_TYPE_P (type) && TYPE_PTR_P (intype))
5260 if (TYPE_PRECISION (type) < TYPE_PRECISION (intype))
5261 pedwarn ("cast from %qT to %qT loses precision",
5264 /* [expr.reinterpret.cast]
5265 A value of integral or enumeration type can be explicitly
5266 converted to a pointer. */
5267 else if (TYPE_PTR_P (type) && INTEGRAL_OR_ENUMERATION_TYPE_P (intype))
5270 else if ((TYPE_PTRFN_P (type) && TYPE_PTRFN_P (intype))
5271 || (TYPE_PTRMEMFUNC_P (type) && TYPE_PTRMEMFUNC_P (intype)))
5272 return fold_if_not_in_template (build_nop (type, expr));
5273 else if ((TYPE_PTRMEM_P (type) && TYPE_PTRMEM_P (intype))
5274 || (TYPE_PTROBV_P (type) && TYPE_PTROBV_P (intype)))
5279 check_for_casting_away_constness (intype, type, error,
5280 "reinterpret_cast");
5281 /* Warn about possible alignment problems. */
5282 if (STRICT_ALIGNMENT && warn_cast_align
5283 && !VOID_TYPE_P (type)
5284 && TREE_CODE (TREE_TYPE (intype)) != FUNCTION_TYPE
5285 && COMPLETE_TYPE_P (TREE_TYPE (type))
5286 && COMPLETE_TYPE_P (TREE_TYPE (intype))
5287 && TYPE_ALIGN (TREE_TYPE (type)) > TYPE_ALIGN (TREE_TYPE (intype)))
5288 warning (0, "cast from %qT to %qT increases required alignment of "
5292 /* We need to strip nops here, because the front end likes to
5293 create (int *)&a for array-to-pointer decay, instead of &a[0]. */
5295 strict_aliasing_warning (intype, type, sexpr);
5297 return fold_if_not_in_template (build_nop (type, expr));
5299 else if ((TYPE_PTRFN_P (type) && TYPE_PTROBV_P (intype))
5300 || (TYPE_PTRFN_P (intype) && TYPE_PTROBV_P (type)))
5303 /* Only issue a warning, as we have always supported this
5304 where possible, and it is necessary in some cases. DR 195
5305 addresses this issue, but as of 2004/10/26 is still in
5307 warning (0, "ISO C++ forbids casting between pointer-to-function and pointer-to-object");
5308 return fold_if_not_in_template (build_nop (type, expr));
5310 else if (TREE_CODE (type) == VECTOR_TYPE)
5311 return fold_if_not_in_template (convert_to_vector (type, expr));
5312 else if (TREE_CODE (intype) == VECTOR_TYPE)
5313 return fold_if_not_in_template (convert_to_integer (type, expr));
5318 error ("invalid cast from type %qT to type %qT", intype, type);
5319 return error_mark_node;
5322 return cp_convert (type, expr);
5326 build_reinterpret_cast (tree type, tree expr)
5328 if (type == error_mark_node || expr == error_mark_node)
5329 return error_mark_node;
5331 if (processing_template_decl)
5333 tree t = build_min (REINTERPRET_CAST_EXPR, type, expr);
5335 if (!TREE_SIDE_EFFECTS (t)
5336 && type_dependent_expression_p (expr))
5337 /* There might turn out to be side effects inside expr. */
5338 TREE_SIDE_EFFECTS (t) = 1;
5339 return convert_from_reference (t);
5342 return build_reinterpret_cast_1 (type, expr, /*c_cast_p=*/false,
5346 /* Perform a const_cast from EXPR to TYPE. If the cast is valid,
5347 return an appropriate expression. Otherwise, return
5348 error_mark_node. If the cast is not valid, and COMPLAIN is true,
5349 then a diagnostic will be issued. If VALID_P is non-NULL, we are
5350 performing a C-style cast, its value upon return will indicate
5351 whether or not the conversion succeeded. */
5354 build_const_cast_1 (tree dst_type, tree expr, bool complain,
5358 tree reference_type;
5360 /* Callers are responsible for handling error_mark_node as a
5361 destination type. */
5362 gcc_assert (dst_type != error_mark_node);
5363 /* In a template, callers should be building syntactic
5364 representations of casts, not using this machinery. */
5365 gcc_assert (!processing_template_decl);
5367 /* Assume the conversion is invalid. */
5371 if (!POINTER_TYPE_P (dst_type) && !TYPE_PTRMEM_P (dst_type))
5374 error ("invalid use of const_cast with type %qT, "
5375 "which is not a pointer, "
5376 "reference, nor a pointer-to-data-member type", dst_type);
5377 return error_mark_node;
5380 if (TREE_CODE (TREE_TYPE (dst_type)) == FUNCTION_TYPE)
5383 error ("invalid use of const_cast with type %qT, which is a pointer "
5384 "or reference to a function type", dst_type);
5385 return error_mark_node;
5388 /* Save casted types in the function's used types hash table. */
5389 used_types_insert (dst_type);
5391 src_type = TREE_TYPE (expr);
5392 /* Expressions do not really have reference types. */
5393 if (TREE_CODE (src_type) == REFERENCE_TYPE)
5394 src_type = TREE_TYPE (src_type);
5396 /* [expr.const.cast]
5398 An lvalue of type T1 can be explicitly converted to an lvalue of
5399 type T2 using the cast const_cast<T2&> (where T1 and T2 are object
5400 types) if a pointer to T1 can be explicitly converted to the type
5401 pointer to T2 using a const_cast. */
5402 if (TREE_CODE (dst_type) == REFERENCE_TYPE)
5404 reference_type = dst_type;
5405 if (! real_lvalue_p (expr))
5408 error ("invalid const_cast of an rvalue of type %qT to type %qT",
5409 src_type, dst_type);
5410 return error_mark_node;
5412 dst_type = build_pointer_type (TREE_TYPE (dst_type));
5413 src_type = build_pointer_type (src_type);
5417 reference_type = NULL_TREE;
5418 /* If the destination type is not a reference type, the
5419 lvalue-to-rvalue, array-to-pointer, and function-to-pointer
5420 conversions are performed. */
5421 src_type = type_decays_to (src_type);
5422 if (src_type == error_mark_node)
5423 return error_mark_node;
5426 if ((TYPE_PTR_P (src_type) || TYPE_PTRMEM_P (src_type))
5427 && comp_ptr_ttypes_const (dst_type, src_type))
5432 /* This cast is actually a C-style cast. Issue a warning if
5433 the user is making a potentially unsafe cast. */
5435 check_for_casting_away_constness (src_type, dst_type,
5441 expr = build_unary_op (ADDR_EXPR, expr, 0);
5442 expr = build_nop (reference_type, expr);
5443 return convert_from_reference (expr);
5447 expr = decay_conversion (expr);
5448 /* build_c_cast puts on a NOP_EXPR to make the result not an
5449 lvalue. Strip such NOP_EXPRs if VALUE is being used in
5450 non-lvalue context. */
5451 if (TREE_CODE (expr) == NOP_EXPR
5452 && TREE_TYPE (expr) == TREE_TYPE (TREE_OPERAND (expr, 0)))
5453 expr = TREE_OPERAND (expr, 0);
5454 return build_nop (dst_type, expr);
5459 error ("invalid const_cast from type %qT to type %qT",
5460 src_type, dst_type);
5461 return error_mark_node;
5465 build_const_cast (tree type, tree expr)
5467 if (type == error_mark_node || error_operand_p (expr))
5468 return error_mark_node;
5470 if (processing_template_decl)
5472 tree t = build_min (CONST_CAST_EXPR, type, expr);
5474 if (!TREE_SIDE_EFFECTS (t)
5475 && type_dependent_expression_p (expr))
5476 /* There might turn out to be side effects inside expr. */
5477 TREE_SIDE_EFFECTS (t) = 1;
5478 return convert_from_reference (t);
5481 return build_const_cast_1 (type, expr, /*complain=*/true,
5485 /* Build an expression representing an explicit C-style cast to type
5486 TYPE of expression EXPR. */
5489 build_c_cast (tree type, tree expr)
5495 if (type == error_mark_node || error_operand_p (expr))
5496 return error_mark_node;
5498 if (processing_template_decl)
5500 tree t = build_min (CAST_EXPR, type,
5501 tree_cons (NULL_TREE, value, NULL_TREE));
5502 /* We don't know if it will or will not have side effects. */
5503 TREE_SIDE_EFFECTS (t) = 1;
5504 return convert_from_reference (t);
5507 /* Casts to a (pointer to a) specific ObjC class (or 'id' or
5508 'Class') should always be retained, because this information aids
5509 in method lookup. */
5510 if (objc_is_object_ptr (type)
5511 && objc_is_object_ptr (TREE_TYPE (expr)))
5512 return build_nop (type, expr);
5514 /* build_c_cast puts on a NOP_EXPR to make the result not an lvalue.
5515 Strip such NOP_EXPRs if VALUE is being used in non-lvalue context. */
5516 if (TREE_CODE (type) != REFERENCE_TYPE
5517 && TREE_CODE (value) == NOP_EXPR
5518 && TREE_TYPE (value) == TREE_TYPE (TREE_OPERAND (value, 0)))
5519 value = TREE_OPERAND (value, 0);
5521 if (TREE_CODE (type) == ARRAY_TYPE)
5523 /* Allow casting from T1* to T2[] because Cfront allows it.
5524 NIHCL uses it. It is not valid ISO C++ however. */
5525 if (TREE_CODE (TREE_TYPE (expr)) == POINTER_TYPE)
5527 pedwarn ("ISO C++ forbids casting to an array type %qT", type);
5528 type = build_pointer_type (TREE_TYPE (type));
5532 error ("ISO C++ forbids casting to an array type %qT", type);
5533 return error_mark_node;
5537 if (TREE_CODE (type) == FUNCTION_TYPE
5538 || TREE_CODE (type) == METHOD_TYPE)
5540 error ("invalid cast to function type %qT", type);
5541 return error_mark_node;
5544 /* A C-style cast can be a const_cast. */
5545 result = build_const_cast_1 (type, value, /*complain=*/false,
5550 /* Or a static cast. */
5551 result = build_static_cast_1 (type, value, /*c_cast_p=*/true,
5553 /* Or a reinterpret_cast. */
5555 result = build_reinterpret_cast_1 (type, value, /*c_cast_p=*/true,
5557 /* The static_cast or reinterpret_cast may be followed by a
5560 /* A valid cast may result in errors if, for example, a
5561 conversion to am ambiguous base class is required. */
5562 && !error_operand_p (result))
5566 /* Non-class rvalues always have cv-unqualified type. */
5567 if (!CLASS_TYPE_P (type))
5568 type = TYPE_MAIN_VARIANT (type);
5569 result_type = TREE_TYPE (result);
5570 if (!CLASS_TYPE_P (result_type))
5571 result_type = TYPE_MAIN_VARIANT (result_type);
5572 /* If the type of RESULT does not match TYPE, perform a
5573 const_cast to make it match. If the static_cast or
5574 reinterpret_cast succeeded, we will differ by at most
5575 cv-qualification, so the follow-on const_cast is guaranteed
5577 if (!same_type_p (non_reference (type), non_reference (result_type)))
5579 result = build_const_cast_1 (type, result, false, &valid_p);
5580 gcc_assert (valid_p);
5585 return error_mark_node;
5588 /* Build an assignment expression of lvalue LHS from value RHS.
5589 MODIFYCODE is the code for a binary operator that we use
5590 to combine the old value of LHS with RHS to get the new value.
5591 Or else MODIFYCODE is NOP_EXPR meaning do a simple assignment.
5593 C++: If MODIFYCODE is INIT_EXPR, then leave references unbashed. */
5596 build_modify_expr (tree lhs, enum tree_code modifycode, tree rhs)
5600 tree lhstype = TREE_TYPE (lhs);
5601 tree olhstype = lhstype;
5602 tree olhs = NULL_TREE;
5603 bool plain_assign = (modifycode == NOP_EXPR);
5605 /* Avoid duplicate error messages from operands that had errors. */
5606 if (error_operand_p (lhs) || error_operand_p (rhs))
5607 return error_mark_node;
5609 /* Handle control structure constructs used as "lvalues". */
5610 switch (TREE_CODE (lhs))
5612 /* Handle --foo = 5; as these are valid constructs in C++. */
5613 case PREDECREMENT_EXPR:
5614 case PREINCREMENT_EXPR:
5615 if (TREE_SIDE_EFFECTS (TREE_OPERAND (lhs, 0)))
5616 lhs = build2 (TREE_CODE (lhs), TREE_TYPE (lhs),
5617 stabilize_reference (TREE_OPERAND (lhs, 0)),
5618 TREE_OPERAND (lhs, 1));
5619 return build2 (COMPOUND_EXPR, lhstype,
5621 build_modify_expr (TREE_OPERAND (lhs, 0),
5624 /* Handle (a, b) used as an "lvalue". */
5626 newrhs = build_modify_expr (TREE_OPERAND (lhs, 1),
5628 if (newrhs == error_mark_node)
5629 return error_mark_node;
5630 return build2 (COMPOUND_EXPR, lhstype,
5631 TREE_OPERAND (lhs, 0), newrhs);
5634 if (TREE_SIDE_EFFECTS (TREE_OPERAND (lhs, 0)))
5635 lhs = build2 (TREE_CODE (lhs), TREE_TYPE (lhs),
5636 stabilize_reference (TREE_OPERAND (lhs, 0)),
5637 TREE_OPERAND (lhs, 1));
5638 newrhs = build_modify_expr (TREE_OPERAND (lhs, 0), modifycode, rhs);
5639 if (newrhs == error_mark_node)
5640 return error_mark_node;
5641 return build2 (COMPOUND_EXPR, lhstype, lhs, newrhs);
5645 /* MIN_EXPR and MAX_EXPR are currently only permitted as lvalues,
5646 when neither operand has side-effects. */
5647 if (!lvalue_or_else (lhs, lv_assign))
5648 return error_mark_node;
5650 gcc_assert (!TREE_SIDE_EFFECTS (TREE_OPERAND (lhs, 0))
5651 && !TREE_SIDE_EFFECTS (TREE_OPERAND (lhs, 1)));
5653 lhs = build3 (COND_EXPR, TREE_TYPE (lhs),
5654 build2 (TREE_CODE (lhs) == MIN_EXPR ? LE_EXPR : GE_EXPR,
5656 TREE_OPERAND (lhs, 0),
5657 TREE_OPERAND (lhs, 1)),
5658 TREE_OPERAND (lhs, 0),
5659 TREE_OPERAND (lhs, 1));
5662 /* Handle (a ? b : c) used as an "lvalue". */
5665 /* Produce (a ? (b = rhs) : (c = rhs))
5666 except that the RHS goes through a save-expr
5667 so the code to compute it is only emitted once. */
5669 tree preeval = NULL_TREE;
5671 rhs = stabilize_expr (rhs, &preeval);
5673 /* Check this here to avoid odd errors when trying to convert
5674 a throw to the type of the COND_EXPR. */
5675 if (!lvalue_or_else (lhs, lv_assign))
5676 return error_mark_node;
5678 cond = build_conditional_expr
5679 (TREE_OPERAND (lhs, 0),
5680 build_modify_expr (TREE_OPERAND (lhs, 1),
5682 build_modify_expr (TREE_OPERAND (lhs, 2),
5685 if (cond == error_mark_node)
5687 /* Make sure the code to compute the rhs comes out
5688 before the split. */
5690 cond = build2 (COMPOUND_EXPR, TREE_TYPE (lhs), preeval, cond);
5698 if (modifycode == INIT_EXPR)
5700 if (TREE_CODE (rhs) == CONSTRUCTOR)
5702 if (! same_type_p (TREE_TYPE (rhs), lhstype))
5703 /* Call convert to generate an error; see PR 11063. */
5704 rhs = convert (lhstype, rhs);
5705 result = build2 (INIT_EXPR, lhstype, lhs, rhs);
5706 TREE_SIDE_EFFECTS (result) = 1;
5709 else if (! IS_AGGR_TYPE (lhstype))
5710 /* Do the default thing. */;
5713 result = build_special_member_call (lhs, complete_ctor_identifier,
5714 build_tree_list (NULL_TREE, rhs),
5715 lhstype, LOOKUP_NORMAL);
5716 if (result == NULL_TREE)
5717 return error_mark_node;
5723 lhs = require_complete_type (lhs);
5724 if (lhs == error_mark_node)
5725 return error_mark_node;
5727 if (modifycode == NOP_EXPR)
5729 /* `operator=' is not an inheritable operator. */
5730 if (! IS_AGGR_TYPE (lhstype))
5731 /* Do the default thing. */;
5734 result = build_new_op (MODIFY_EXPR, LOOKUP_NORMAL,
5735 lhs, rhs, make_node (NOP_EXPR),
5736 /*overloaded_p=*/NULL);
5737 if (result == NULL_TREE)
5738 return error_mark_node;
5745 /* A binary op has been requested. Combine the old LHS
5746 value with the RHS producing the value we should actually
5747 store into the LHS. */
5749 gcc_assert (!PROMOTES_TO_AGGR_TYPE (lhstype, REFERENCE_TYPE));
5750 lhs = stabilize_reference (lhs);
5751 newrhs = cp_build_binary_op (modifycode, lhs, rhs);
5752 if (newrhs == error_mark_node)
5754 error (" in evaluation of %<%Q(%#T, %#T)%>", modifycode,
5755 TREE_TYPE (lhs), TREE_TYPE (rhs));
5756 return error_mark_node;
5759 /* Now it looks like a plain assignment. */
5760 modifycode = NOP_EXPR;
5762 gcc_assert (TREE_CODE (lhstype) != REFERENCE_TYPE);
5763 gcc_assert (TREE_CODE (TREE_TYPE (newrhs)) != REFERENCE_TYPE);
5766 /* The left-hand side must be an lvalue. */
5767 if (!lvalue_or_else (lhs, lv_assign))
5768 return error_mark_node;
5770 /* Warn about modifying something that is `const'. Don't warn if
5771 this is initialization. */
5772 if (modifycode != INIT_EXPR
5773 && (TREE_READONLY (lhs) || CP_TYPE_CONST_P (lhstype)
5774 /* Functions are not modifiable, even though they are
5776 || TREE_CODE (TREE_TYPE (lhs)) == FUNCTION_TYPE
5777 || TREE_CODE (TREE_TYPE (lhs)) == METHOD_TYPE
5778 /* If it's an aggregate and any field is const, then it is
5779 effectively const. */
5780 || (CLASS_TYPE_P (lhstype)
5781 && C_TYPE_FIELDS_READONLY (lhstype))))
5782 readonly_error (lhs, "assignment");
5784 /* If storing into a structure or union member, it has probably been
5785 given type `int'. Compute the type that would go with the actual
5786 amount of storage the member occupies. */
5788 if (TREE_CODE (lhs) == COMPONENT_REF
5789 && (TREE_CODE (lhstype) == INTEGER_TYPE
5790 || TREE_CODE (lhstype) == REAL_TYPE
5791 || TREE_CODE (lhstype) == ENUMERAL_TYPE))
5793 lhstype = TREE_TYPE (get_unwidened (lhs, 0));
5795 /* If storing in a field that is in actuality a short or narrower
5796 than one, we must store in the field in its actual type. */
5798 if (lhstype != TREE_TYPE (lhs))
5800 /* Avoid warnings converting integral types back into enums for
5802 if (TREE_CODE (lhstype) == INTEGER_TYPE
5803 && TREE_CODE (olhstype) == ENUMERAL_TYPE)
5805 if (TREE_SIDE_EFFECTS (lhs))
5806 lhs = stabilize_reference (lhs);
5809 lhs = copy_node (lhs);
5810 TREE_TYPE (lhs) = lhstype;
5814 /* Convert new value to destination type. */
5816 if (TREE_CODE (lhstype) == ARRAY_TYPE)
5820 if (!same_or_base_type_p (TYPE_MAIN_VARIANT (lhstype),
5821 TYPE_MAIN_VARIANT (TREE_TYPE (rhs))))
5823 error ("incompatible types in assignment of %qT to %qT",
5824 TREE_TYPE (rhs), lhstype);
5825 return error_mark_node;
5828 /* Allow array assignment in compiler-generated code. */
5829 if (! DECL_ARTIFICIAL (current_function_decl))
5831 /* This routine is used for both initialization and assignment.
5832 Make sure the diagnostic message differentiates the context. */
5833 if (modifycode == INIT_EXPR)
5834 error ("array used as initializer");
5836 error ("invalid array assignment");
5837 return error_mark_node;
5840 from_array = TREE_CODE (TREE_TYPE (newrhs)) == ARRAY_TYPE
5841 ? 1 + (modifycode != INIT_EXPR): 0;
5842 return build_vec_init (lhs, NULL_TREE, newrhs,
5843 /*explicit_default_init_p=*/false,
5847 if (modifycode == INIT_EXPR)
5848 newrhs = convert_for_initialization (lhs, lhstype, newrhs, LOOKUP_NORMAL,
5849 "initialization", NULL_TREE, 0);
5852 /* Avoid warnings on enum bit fields. */
5853 if (TREE_CODE (olhstype) == ENUMERAL_TYPE
5854 && TREE_CODE (lhstype) == INTEGER_TYPE)
5856 newrhs = convert_for_assignment (olhstype, newrhs, "assignment",
5858 newrhs = convert_force (lhstype, newrhs, 0);
5861 newrhs = convert_for_assignment (lhstype, newrhs, "assignment",
5863 if (TREE_CODE (newrhs) == CALL_EXPR
5864 && TYPE_NEEDS_CONSTRUCTING (lhstype))
5865 newrhs = build_cplus_new (lhstype, newrhs);
5867 /* Can't initialize directly from a TARGET_EXPR, since that would
5868 cause the lhs to be constructed twice, and possibly result in
5869 accidental self-initialization. So we force the TARGET_EXPR to be
5870 expanded without a target. */
5871 if (TREE_CODE (newrhs) == TARGET_EXPR)
5872 newrhs = build2 (COMPOUND_EXPR, TREE_TYPE (newrhs), newrhs,
5873 TREE_OPERAND (newrhs, 0));
5876 if (newrhs == error_mark_node)
5877 return error_mark_node;
5879 if (c_dialect_objc () && flag_objc_gc)
5881 result = objc_generate_write_barrier (lhs, modifycode, newrhs);
5887 result = build2 (modifycode == NOP_EXPR ? MODIFY_EXPR : INIT_EXPR,
5888 lhstype, lhs, newrhs);
5890 TREE_SIDE_EFFECTS (result) = 1;
5892 TREE_NO_WARNING (result) = 1;
5894 /* If we got the LHS in a different type for storing in,
5895 convert the result back to the nominal type of LHS
5896 so that the value we return always has the same type
5897 as the LHS argument. */
5899 if (olhstype == TREE_TYPE (result))
5903 result = build2 (COMPOUND_EXPR, olhstype, result, olhs);
5904 TREE_NO_WARNING (result) = 1;
5907 return convert_for_assignment (olhstype, result, "assignment",
5912 build_x_modify_expr (tree lhs, enum tree_code modifycode, tree rhs)
5914 if (processing_template_decl)
5915 return build_min_nt (MODOP_EXPR, lhs,
5916 build_min_nt (modifycode, NULL_TREE, NULL_TREE), rhs);
5918 if (modifycode != NOP_EXPR)
5920 tree rval = build_new_op (MODIFY_EXPR, LOOKUP_NORMAL, lhs, rhs,
5921 make_node (modifycode),
5922 /*overloaded_p=*/NULL);
5925 TREE_NO_WARNING (rval) = 1;
5929 return build_modify_expr (lhs, modifycode, rhs);
5933 /* Get difference in deltas for different pointer to member function
5934 types. Returns an integer constant of type PTRDIFF_TYPE_NODE. If
5935 the conversion is invalid, the constant is zero. If
5936 ALLOW_INVERSE_P is true, then allow reverse conversions as well.
5937 If C_CAST_P is true this conversion is taking place as part of a
5940 Note that the naming of FROM and TO is kind of backwards; the return
5941 value is what we add to a TO in order to get a FROM. They are named
5942 this way because we call this function to find out how to convert from
5943 a pointer to member of FROM to a pointer to member of TO. */
5946 get_delta_difference (tree from, tree to,
5947 bool allow_inverse_p,
5954 /* Assume no conversion is required. */
5955 result = integer_zero_node;
5956 binfo = lookup_base (to, from, c_cast_p ? ba_unique : ba_check, &kind);
5957 if (kind == bk_inaccessible || kind == bk_ambig)
5958 error (" in pointer to member function conversion");
5961 if (kind != bk_via_virtual)
5962 result = BINFO_OFFSET (binfo);
5965 tree virt_binfo = binfo_from_vbase (binfo);
5967 /* This is a reinterpret cast, we choose to do nothing. */
5968 if (allow_inverse_p)
5969 warning (0, "pointer to member cast via virtual base %qT",
5970 BINFO_TYPE (virt_binfo));
5972 error ("pointer to member conversion via virtual base %qT",
5973 BINFO_TYPE (virt_binfo));
5976 else if (same_type_ignoring_top_level_qualifiers_p (from, to))
5977 /* Pointer to member of incomplete class is permitted*/;
5978 else if (!allow_inverse_p)
5980 error_not_base_type (from, to);
5981 error (" in pointer to member conversion");
5985 binfo = lookup_base (from, to, c_cast_p ? ba_unique : ba_check, &kind);
5988 if (kind != bk_via_virtual)
5989 result = size_diffop (size_zero_node, BINFO_OFFSET (binfo));
5992 /* This is a reinterpret cast, we choose to do nothing. */
5993 tree virt_binfo = binfo_from_vbase (binfo);
5995 warning (0, "pointer to member cast via virtual base %qT",
5996 BINFO_TYPE (virt_binfo));
6001 return fold_if_not_in_template (convert_to_integer (ptrdiff_type_node,
6005 /* Return a constructor for the pointer-to-member-function TYPE using
6006 the other components as specified. */
6009 build_ptrmemfunc1 (tree type, tree delta, tree pfn)
6014 VEC(constructor_elt, gc) *v;
6016 /* Pull the FIELD_DECLs out of the type. */
6017 pfn_field = TYPE_FIELDS (type);
6018 delta_field = TREE_CHAIN (pfn_field);
6020 /* Make sure DELTA has the type we want. */
6021 delta = convert_and_check (delta_type_node, delta);
6023 /* Finish creating the initializer. */
6024 v = VEC_alloc(constructor_elt, gc, 2);
6025 CONSTRUCTOR_APPEND_ELT(v, pfn_field, pfn);
6026 CONSTRUCTOR_APPEND_ELT(v, delta_field, delta);
6027 u = build_constructor (type, v);
6028 TREE_CONSTANT (u) = TREE_CONSTANT (pfn) & TREE_CONSTANT (delta);
6029 TREE_INVARIANT (u) = TREE_INVARIANT (pfn) & TREE_INVARIANT (delta);
6030 TREE_STATIC (u) = (TREE_CONSTANT (u)
6031 && (initializer_constant_valid_p (pfn, TREE_TYPE (pfn))
6033 && (initializer_constant_valid_p (delta, TREE_TYPE (delta))
6038 /* Build a constructor for a pointer to member function. It can be
6039 used to initialize global variables, local variable, or used
6040 as a value in expressions. TYPE is the POINTER to METHOD_TYPE we
6043 If FORCE is nonzero, then force this conversion, even if
6044 we would rather not do it. Usually set when using an explicit
6045 cast. A C-style cast is being processed iff C_CAST_P is true.
6047 Return error_mark_node, if something goes wrong. */
6050 build_ptrmemfunc (tree type, tree pfn, int force, bool c_cast_p)
6056 if (error_operand_p (pfn))
6057 return error_mark_node;
6059 pfn_type = TREE_TYPE (pfn);
6060 to_type = build_ptrmemfunc_type (type);
6062 /* Handle multiple conversions of pointer to member functions. */
6063 if (TYPE_PTRMEMFUNC_P (pfn_type))
6065 tree delta = NULL_TREE;
6066 tree npfn = NULL_TREE;
6070 && !can_convert_arg (to_type, TREE_TYPE (pfn), pfn, LOOKUP_NORMAL))
6071 error ("invalid conversion to type %qT from type %qT",
6074 n = get_delta_difference (TYPE_PTRMEMFUNC_OBJECT_TYPE (pfn_type),
6075 TYPE_PTRMEMFUNC_OBJECT_TYPE (to_type),
6079 /* We don't have to do any conversion to convert a
6080 pointer-to-member to its own type. But, we don't want to
6081 just return a PTRMEM_CST if there's an explicit cast; that
6082 cast should make the expression an invalid template argument. */
6083 if (TREE_CODE (pfn) != PTRMEM_CST)
6085 if (same_type_p (to_type, pfn_type))
6087 else if (integer_zerop (n))
6088 return build_reinterpret_cast (to_type, pfn);
6091 if (TREE_SIDE_EFFECTS (pfn))
6092 pfn = save_expr (pfn);
6094 /* Obtain the function pointer and the current DELTA. */
6095 if (TREE_CODE (pfn) == PTRMEM_CST)
6096 expand_ptrmemfunc_cst (pfn, &delta, &npfn);
6099 npfn = build_ptrmemfunc_access_expr (pfn, pfn_identifier);
6100 delta = build_ptrmemfunc_access_expr (pfn, delta_identifier);
6103 /* Just adjust the DELTA field. */
6104 gcc_assert (same_type_ignoring_top_level_qualifiers_p
6105 (TREE_TYPE (delta), ptrdiff_type_node));
6106 if (TARGET_PTRMEMFUNC_VBIT_LOCATION == ptrmemfunc_vbit_in_delta)
6107 n = cp_build_binary_op (LSHIFT_EXPR, n, integer_one_node);
6108 delta = cp_build_binary_op (PLUS_EXPR, delta, n);
6109 return build_ptrmemfunc1 (to_type, delta, npfn);
6112 /* Handle null pointer to member function conversions. */
6113 if (integer_zerop (pfn))
6115 pfn = build_c_cast (type, integer_zero_node);
6116 return build_ptrmemfunc1 (to_type,
6121 if (type_unknown_p (pfn))
6122 return instantiate_type (type, pfn, tf_warning_or_error);
6124 fn = TREE_OPERAND (pfn, 0);
6125 gcc_assert (TREE_CODE (fn) == FUNCTION_DECL
6126 /* In a template, we will have preserved the
6128 || (processing_template_decl && TREE_CODE (fn) == OFFSET_REF));
6129 return make_ptrmem_cst (to_type, fn);
6132 /* Return the DELTA, IDX, PFN, and DELTA2 values for the PTRMEM_CST
6135 ??? There is no consistency as to the types returned for the above
6136 values. Some code acts as if it were a sizetype and some as if it were
6137 integer_type_node. */
6140 expand_ptrmemfunc_cst (tree cst, tree *delta, tree *pfn)
6142 tree type = TREE_TYPE (cst);
6143 tree fn = PTRMEM_CST_MEMBER (cst);
6144 tree ptr_class, fn_class;
6146 gcc_assert (TREE_CODE (fn) == FUNCTION_DECL);
6148 /* The class that the function belongs to. */
6149 fn_class = DECL_CONTEXT (fn);
6151 /* The class that we're creating a pointer to member of. */
6152 ptr_class = TYPE_PTRMEMFUNC_OBJECT_TYPE (type);
6154 /* First, calculate the adjustment to the function's class. */
6155 *delta = get_delta_difference (fn_class, ptr_class, /*force=*/0,
6158 if (!DECL_VIRTUAL_P (fn))
6159 *pfn = convert (TYPE_PTRMEMFUNC_FN_TYPE (type), build_addr_func (fn));
6162 /* If we're dealing with a virtual function, we have to adjust 'this'
6163 again, to point to the base which provides the vtable entry for
6164 fn; the call will do the opposite adjustment. */
6165 tree orig_class = DECL_CONTEXT (fn);
6166 tree binfo = binfo_or_else (orig_class, fn_class);
6167 *delta = build2 (PLUS_EXPR, TREE_TYPE (*delta),
6168 *delta, BINFO_OFFSET (binfo));
6169 *delta = fold_if_not_in_template (*delta);
6171 /* We set PFN to the vtable offset at which the function can be
6172 found, plus one (unless ptrmemfunc_vbit_in_delta, in which
6173 case delta is shifted left, and then incremented). */
6174 *pfn = DECL_VINDEX (fn);
6175 *pfn = build2 (MULT_EXPR, integer_type_node, *pfn,
6176 TYPE_SIZE_UNIT (vtable_entry_type));
6177 *pfn = fold_if_not_in_template (*pfn);
6179 switch (TARGET_PTRMEMFUNC_VBIT_LOCATION)
6181 case ptrmemfunc_vbit_in_pfn:
6182 *pfn = build2 (PLUS_EXPR, integer_type_node, *pfn,
6184 *pfn = fold_if_not_in_template (*pfn);
6187 case ptrmemfunc_vbit_in_delta:
6188 *delta = build2 (LSHIFT_EXPR, TREE_TYPE (*delta),
6189 *delta, integer_one_node);
6190 *delta = fold_if_not_in_template (*delta);
6191 *delta = build2 (PLUS_EXPR, TREE_TYPE (*delta),
6192 *delta, integer_one_node);
6193 *delta = fold_if_not_in_template (*delta);
6200 *pfn = build_nop (TYPE_PTRMEMFUNC_FN_TYPE (type), *pfn);
6201 *pfn = fold_if_not_in_template (*pfn);
6205 /* Return an expression for PFN from the pointer-to-member function
6209 pfn_from_ptrmemfunc (tree t)
6211 if (TREE_CODE (t) == PTRMEM_CST)
6216 expand_ptrmemfunc_cst (t, &delta, &pfn);
6221 return build_ptrmemfunc_access_expr (t, pfn_identifier);
6224 /* Convert value RHS to type TYPE as preparation for an assignment to
6225 an lvalue of type TYPE. ERRTYPE is a string to use in error
6226 messages: "assignment", "return", etc. If FNDECL is non-NULL, we
6227 are doing the conversion in order to pass the PARMNUMth argument of
6231 convert_for_assignment (tree type, tree rhs,
6232 const char *errtype, tree fndecl, int parmnum)
6235 enum tree_code coder;
6237 /* Strip NON_LVALUE_EXPRs since we aren't using as an lvalue. */
6238 if (TREE_CODE (rhs) == NON_LVALUE_EXPR)
6239 rhs = TREE_OPERAND (rhs, 0);
6241 rhstype = TREE_TYPE (rhs);
6242 coder = TREE_CODE (rhstype);
6244 if (TREE_CODE (type) == VECTOR_TYPE && coder == VECTOR_TYPE
6245 && vector_types_convertible_p (type, rhstype, true))
6246 return convert (type, rhs);
6248 if (rhs == error_mark_node || rhstype == error_mark_node)
6249 return error_mark_node;
6250 if (TREE_CODE (rhs) == TREE_LIST && TREE_VALUE (rhs) == error_mark_node)
6251 return error_mark_node;
6253 /* The RHS of an assignment cannot have void type. */
6254 if (coder == VOID_TYPE)
6256 error ("void value not ignored as it ought to be");
6257 return error_mark_node;
6260 /* Simplify the RHS if possible. */
6261 if (TREE_CODE (rhs) == CONST_DECL)
6262 rhs = DECL_INITIAL (rhs);
6264 if (c_dialect_objc ())
6267 tree rname = fndecl;
6269 if (!strcmp (errtype, "assignment"))
6271 else if (!strcmp (errtype, "initialization"))
6275 tree selector = objc_message_selector ();
6279 if (selector && parmno > 1)
6286 if (objc_compare_types (type, rhstype, parmno, rname))
6287 return convert (type, rhs);
6292 The expression is implicitly converted (clause _conv_) to the
6293 cv-unqualified type of the left operand.
6295 We allow bad conversions here because by the time we get to this point
6296 we are committed to doing the conversion. If we end up doing a bad
6297 conversion, convert_like will complain. */
6298 if (!can_convert_arg_bad (type, rhstype, rhs))
6300 /* When -Wno-pmf-conversions is use, we just silently allow
6301 conversions from pointers-to-members to plain pointers. If
6302 the conversion doesn't work, cp_convert will complain. */
6304 && TYPE_PTR_P (type)
6305 && TYPE_PTRMEMFUNC_P (rhstype))
6306 rhs = cp_convert (strip_top_quals (type), rhs);
6309 /* If the right-hand side has unknown type, then it is an
6310 overloaded function. Call instantiate_type to get error
6312 if (rhstype == unknown_type_node)
6313 instantiate_type (type, rhs, tf_warning_or_error);
6315 error ("cannot convert %qT to %qT for argument %qP to %qD",
6316 rhstype, type, parmnum, fndecl);
6318 error ("cannot convert %qT to %qT in %s", rhstype, type, errtype);
6319 return error_mark_node;
6322 if (warn_missing_format_attribute)
6324 const enum tree_code codel = TREE_CODE (type);
6325 if ((codel == POINTER_TYPE || codel == REFERENCE_TYPE)
6327 && check_missing_format_attribute (type, rhstype))
6328 warning (OPT_Wmissing_format_attribute,
6329 "%s might be a candidate for a format attribute",
6333 /* If -Wparentheses, warn about a = b = c when a has type bool and b
6335 if (warn_parentheses
6336 && type == boolean_type_node
6337 && TREE_CODE (rhs) == MODIFY_EXPR
6338 && !TREE_NO_WARNING (rhs)
6339 && TREE_TYPE (rhs) != boolean_type_node)
6341 warning (OPT_Wparentheses,
6342 "suggest parentheses around assignment used as truth value");
6343 TREE_NO_WARNING (rhs) = 1;
6346 return perform_implicit_conversion (strip_top_quals (type), rhs);
6349 /* Convert RHS to be of type TYPE.
6350 If EXP is nonzero, it is the target of the initialization.
6351 ERRTYPE is a string to use in error messages.
6353 Two major differences between the behavior of
6354 `convert_for_assignment' and `convert_for_initialization'
6355 are that references are bashed in the former, while
6356 copied in the latter, and aggregates are assigned in
6357 the former (operator=) while initialized in the
6360 If using constructor make sure no conversion operator exists, if one does
6361 exist, an ambiguity exists.
6363 If flags doesn't include LOOKUP_COMPLAIN, don't complain about anything. */
6366 convert_for_initialization (tree exp, tree type, tree rhs, int flags,
6367 const char *errtype, tree fndecl, int parmnum)
6369 enum tree_code codel = TREE_CODE (type);
6371 enum tree_code coder;
6373 /* build_c_cast puts on a NOP_EXPR to make the result not an lvalue.
6374 Strip such NOP_EXPRs, since RHS is used in non-lvalue context. */
6375 if (TREE_CODE (rhs) == NOP_EXPR
6376 && TREE_TYPE (rhs) == TREE_TYPE (TREE_OPERAND (rhs, 0))
6377 && codel != REFERENCE_TYPE)
6378 rhs = TREE_OPERAND (rhs, 0);
6380 if (type == error_mark_node
6381 || rhs == error_mark_node
6382 || (TREE_CODE (rhs) == TREE_LIST && TREE_VALUE (rhs) == error_mark_node))
6383 return error_mark_node;
6385 if ((TREE_CODE (TREE_TYPE (rhs)) == ARRAY_TYPE
6386 && TREE_CODE (type) != ARRAY_TYPE
6387 && (TREE_CODE (type) != REFERENCE_TYPE
6388 || TREE_CODE (TREE_TYPE (type)) != ARRAY_TYPE))
6389 || (TREE_CODE (TREE_TYPE (rhs)) == FUNCTION_TYPE
6390 && (TREE_CODE (type) != REFERENCE_TYPE
6391 || TREE_CODE (TREE_TYPE (type)) != FUNCTION_TYPE))
6392 || TREE_CODE (TREE_TYPE (rhs)) == METHOD_TYPE)
6393 rhs = decay_conversion (rhs);
6395 rhstype = TREE_TYPE (rhs);
6396 coder = TREE_CODE (rhstype);
6398 if (coder == ERROR_MARK)
6399 return error_mark_node;
6401 /* We accept references to incomplete types, so we can
6402 return here before checking if RHS is of complete type. */
6404 if (codel == REFERENCE_TYPE)
6406 /* This should eventually happen in convert_arguments. */
6407 int savew = 0, savee = 0;
6410 savew = warningcount, savee = errorcount;
6411 rhs = initialize_reference (type, rhs, /*decl=*/NULL_TREE,
6415 if (warningcount > savew)
6416 warning (0, "in passing argument %P of %q+D", parmnum, fndecl);
6417 else if (errorcount > savee)
6418 error ("in passing argument %P of %q+D", parmnum, fndecl);
6424 exp = require_complete_type (exp);
6425 if (exp == error_mark_node)
6426 return error_mark_node;
6428 rhstype = non_reference (rhstype);
6430 type = complete_type (type);
6432 if (IS_AGGR_TYPE (type))
6433 return ocp_convert (type, rhs, CONV_IMPLICIT|CONV_FORCE_TEMP, flags);
6435 return convert_for_assignment (type, rhs, errtype, fndecl, parmnum);
6438 /* If RETVAL is the address of, or a reference to, a local variable or
6439 temporary give an appropriate warning. */
6442 maybe_warn_about_returning_address_of_local (tree retval)
6444 tree valtype = TREE_TYPE (DECL_RESULT (current_function_decl));
6445 tree whats_returned = retval;
6449 if (TREE_CODE (whats_returned) == COMPOUND_EXPR)
6450 whats_returned = TREE_OPERAND (whats_returned, 1);
6451 else if (TREE_CODE (whats_returned) == CONVERT_EXPR
6452 || TREE_CODE (whats_returned) == NON_LVALUE_EXPR
6453 || TREE_CODE (whats_returned) == NOP_EXPR)
6454 whats_returned = TREE_OPERAND (whats_returned, 0);
6459 if (TREE_CODE (whats_returned) != ADDR_EXPR)
6461 whats_returned = TREE_OPERAND (whats_returned, 0);
6463 if (TREE_CODE (valtype) == REFERENCE_TYPE)
6465 if (TREE_CODE (whats_returned) == AGGR_INIT_EXPR
6466 || TREE_CODE (whats_returned) == TARGET_EXPR)
6468 warning (0, "returning reference to temporary");
6471 if (TREE_CODE (whats_returned) == VAR_DECL
6472 && DECL_NAME (whats_returned)
6473 && TEMP_NAME_P (DECL_NAME (whats_returned)))
6475 warning (0, "reference to non-lvalue returned");
6480 while (TREE_CODE (whats_returned) == COMPONENT_REF
6481 || TREE_CODE (whats_returned) == ARRAY_REF)
6482 whats_returned = TREE_OPERAND (whats_returned, 0);
6484 if (DECL_P (whats_returned)
6485 && DECL_NAME (whats_returned)
6486 && DECL_FUNCTION_SCOPE_P (whats_returned)
6487 && !(TREE_STATIC (whats_returned)
6488 || TREE_PUBLIC (whats_returned)))
6490 if (TREE_CODE (valtype) == REFERENCE_TYPE)
6491 warning (0, "reference to local variable %q+D returned",
6494 warning (0, "address of local variable %q+D returned",
6500 /* Check that returning RETVAL from the current function is valid.
6501 Return an expression explicitly showing all conversions required to
6502 change RETVAL into the function return type, and to assign it to
6503 the DECL_RESULT for the function. Set *NO_WARNING to true if
6504 code reaches end of non-void function warning shouldn't be issued
6505 on this RETURN_EXPR. */
6508 check_return_expr (tree retval, bool *no_warning)
6511 /* The type actually returned by the function, after any
6514 int fn_returns_value_p;
6516 *no_warning = false;
6518 /* A `volatile' function is one that isn't supposed to return, ever.
6519 (This is a G++ extension, used to get better code for functions
6520 that call the `volatile' function.) */
6521 if (TREE_THIS_VOLATILE (current_function_decl))
6522 warning (0, "function declared %<noreturn%> has a %<return%> statement");
6524 /* Check for various simple errors. */
6525 if (DECL_DESTRUCTOR_P (current_function_decl))
6528 error ("returning a value from a destructor");
6531 else if (DECL_CONSTRUCTOR_P (current_function_decl))
6533 if (in_function_try_handler)
6534 /* If a return statement appears in a handler of the
6535 function-try-block of a constructor, the program is ill-formed. */
6536 error ("cannot return from a handler of a function-try-block of a constructor");
6538 /* You can't return a value from a constructor. */
6539 error ("returning a value from a constructor");
6543 if (processing_template_decl)
6545 current_function_returns_value = 1;
6549 /* When no explicit return-value is given in a function with a named
6550 return value, the named return value is used. */
6551 result = DECL_RESULT (current_function_decl);
6552 valtype = TREE_TYPE (result);
6553 gcc_assert (valtype != NULL_TREE);
6554 fn_returns_value_p = !VOID_TYPE_P (valtype);
6555 if (!retval && DECL_NAME (result) && fn_returns_value_p)
6558 /* Check for a return statement with no return value in a function
6559 that's supposed to return a value. */
6560 if (!retval && fn_returns_value_p)
6562 pedwarn ("return-statement with no value, in function returning %qT",
6564 /* Clear this, so finish_function won't say that we reach the
6565 end of a non-void function (which we don't, we gave a
6567 current_function_returns_null = 0;
6568 /* And signal caller that TREE_NO_WARNING should be set on the
6569 RETURN_EXPR to avoid control reaches end of non-void function
6570 warnings in tree-cfg.c. */
6573 /* Check for a return statement with a value in a function that
6574 isn't supposed to return a value. */
6575 else if (retval && !fn_returns_value_p)
6577 if (VOID_TYPE_P (TREE_TYPE (retval)))
6578 /* You can return a `void' value from a function of `void'
6579 type. In that case, we have to evaluate the expression for
6580 its side-effects. */
6581 finish_expr_stmt (retval);
6583 pedwarn ("return-statement with a value, in function "
6584 "returning 'void'");
6586 current_function_returns_null = 1;
6588 /* There's really no value to return, after all. */
6592 /* Remember that this function can sometimes return without a
6594 current_function_returns_null = 1;
6596 /* Remember that this function did return a value. */
6597 current_function_returns_value = 1;
6599 /* Check for erroneous operands -- but after giving ourselves a
6600 chance to provide an error about returning a value from a void
6602 if (error_operand_p (retval))
6604 current_function_return_value = error_mark_node;
6605 return error_mark_node;
6608 /* Only operator new(...) throw(), can return NULL [expr.new/13]. */
6609 if ((DECL_OVERLOADED_OPERATOR_P (current_function_decl) == NEW_EXPR
6610 || DECL_OVERLOADED_OPERATOR_P (current_function_decl) == VEC_NEW_EXPR)
6611 && !TYPE_NOTHROW_P (TREE_TYPE (current_function_decl))
6613 && null_ptr_cst_p (retval))
6614 warning (0, "%<operator new%> must not return NULL unless it is "
6615 "declared %<throw()%> (or -fcheck-new is in effect)");
6617 /* Effective C++ rule 15. See also start_function. */
6619 && DECL_NAME (current_function_decl) == ansi_assopname(NOP_EXPR))
6623 /* The function return type must be a reference to the current
6625 if (TREE_CODE (valtype) == REFERENCE_TYPE
6626 && same_type_ignoring_top_level_qualifiers_p
6627 (TREE_TYPE (valtype), TREE_TYPE (current_class_ref)))
6629 /* Returning '*this' is obviously OK. */
6630 if (retval == current_class_ref)
6632 /* If we are calling a function whose return type is the same of
6633 the current class reference, it is ok. */
6634 else if (TREE_CODE (retval) == INDIRECT_REF
6635 && TREE_CODE (TREE_OPERAND (retval, 0)) == CALL_EXPR)
6640 warning (OPT_Weffc__, "%<operator=%> should return a reference to %<*this%>");
6643 /* The fabled Named Return Value optimization, as per [class.copy]/15:
6645 [...] For a function with a class return type, if the expression
6646 in the return statement is the name of a local object, and the cv-
6647 unqualified type of the local object is the same as the function
6648 return type, an implementation is permitted to omit creating the tem-
6649 porary object to hold the function return value [...]
6651 So, if this is a value-returning function that always returns the same
6652 local variable, remember it.
6654 It might be nice to be more flexible, and choose the first suitable
6655 variable even if the function sometimes returns something else, but
6656 then we run the risk of clobbering the variable we chose if the other
6657 returned expression uses the chosen variable somehow. And people expect
6658 this restriction, anyway. (jason 2000-11-19)
6660 See finish_function and finalize_nrv for the rest of this optimization. */
6662 if (fn_returns_value_p && flag_elide_constructors)
6664 if (retval != NULL_TREE
6665 && (current_function_return_value == NULL_TREE
6666 || current_function_return_value == retval)
6667 && TREE_CODE (retval) == VAR_DECL
6668 && DECL_CONTEXT (retval) == current_function_decl
6669 && ! TREE_STATIC (retval)
6670 && (DECL_ALIGN (retval)
6671 >= DECL_ALIGN (DECL_RESULT (current_function_decl)))
6672 && same_type_p ((TYPE_MAIN_VARIANT
6673 (TREE_TYPE (retval))),
6675 (TREE_TYPE (TREE_TYPE (current_function_decl))))))
6676 current_function_return_value = retval;
6678 current_function_return_value = error_mark_node;
6681 /* We don't need to do any conversions when there's nothing being
6686 /* Do any required conversions. */
6687 if (retval == result || DECL_CONSTRUCTOR_P (current_function_decl))
6688 /* No conversions are required. */
6692 /* The type the function is declared to return. */
6693 tree functype = TREE_TYPE (TREE_TYPE (current_function_decl));
6695 /* The functype's return type will have been set to void, if it
6696 was an incomplete type. Just treat this as 'return;' */
6697 if (VOID_TYPE_P (functype))
6698 return error_mark_node;
6700 /* First convert the value to the function's return type, then
6701 to the type of return value's location to handle the
6702 case that functype is smaller than the valtype. */
6703 retval = convert_for_initialization
6704 (NULL_TREE, functype, retval, LOOKUP_NORMAL|LOOKUP_ONLYCONVERTING,
6705 "return", NULL_TREE, 0);
6706 retval = convert (valtype, retval);
6708 /* If the conversion failed, treat this just like `return;'. */
6709 if (retval == error_mark_node)
6711 /* We can't initialize a register from a AGGR_INIT_EXPR. */
6712 else if (! current_function_returns_struct
6713 && TREE_CODE (retval) == TARGET_EXPR
6714 && TREE_CODE (TREE_OPERAND (retval, 1)) == AGGR_INIT_EXPR)
6715 retval = build2 (COMPOUND_EXPR, TREE_TYPE (retval), retval,
6716 TREE_OPERAND (retval, 0));
6718 maybe_warn_about_returning_address_of_local (retval);
6721 /* Actually copy the value returned into the appropriate location. */
6722 if (retval && retval != result)
6723 retval = build2 (INIT_EXPR, TREE_TYPE (result), result, retval);
6729 /* Returns nonzero if the pointer-type FROM can be converted to the
6730 pointer-type TO via a qualification conversion. If CONSTP is -1,
6731 then we return nonzero if the pointers are similar, and the
6732 cv-qualification signature of FROM is a proper subset of that of TO.
6734 If CONSTP is positive, then all outer pointers have been
6738 comp_ptr_ttypes_real (tree to, tree from, int constp)
6740 bool to_more_cv_qualified = false;
6742 for (; ; to = TREE_TYPE (to), from = TREE_TYPE (from))
6744 if (TREE_CODE (to) != TREE_CODE (from))
6747 if (TREE_CODE (from) == OFFSET_TYPE
6748 && !same_type_p (TYPE_OFFSET_BASETYPE (from),
6749 TYPE_OFFSET_BASETYPE (to)))
6752 /* Const and volatile mean something different for function types,
6753 so the usual checks are not appropriate. */
6754 if (TREE_CODE (to) != FUNCTION_TYPE && TREE_CODE (to) != METHOD_TYPE)
6756 /* In Objective-C++, some types may have been 'volatilized' by
6757 the compiler for EH; when comparing them here, the volatile
6758 qualification must be ignored. */
6759 bool objc_quals_match = objc_type_quals_match (to, from);
6761 if (!at_least_as_qualified_p (to, from) && !objc_quals_match)
6764 if (!at_least_as_qualified_p (from, to) && !objc_quals_match)
6768 to_more_cv_qualified = true;
6772 constp &= TYPE_READONLY (to);
6775 if (TREE_CODE (to) != POINTER_TYPE && !TYPE_PTRMEM_P (to))
6776 return ((constp >= 0 || to_more_cv_qualified)
6777 && same_type_ignoring_top_level_qualifiers_p (to, from));
6781 /* When comparing, say, char ** to char const **, this function takes
6782 the 'char *' and 'char const *'. Do not pass non-pointer/reference
6783 types to this function. */
6786 comp_ptr_ttypes (tree to, tree from)
6788 return comp_ptr_ttypes_real (to, from, 1);
6791 /* Returns 1 if to and from are (possibly multi-level) pointers to the same
6792 type or inheritance-related types, regardless of cv-quals. */
6795 ptr_reasonably_similar (tree to, tree from)
6797 for (; ; to = TREE_TYPE (to), from = TREE_TYPE (from))
6799 /* Any target type is similar enough to void. */
6800 if (TREE_CODE (to) == VOID_TYPE
6801 || TREE_CODE (from) == VOID_TYPE)
6804 if (TREE_CODE (to) != TREE_CODE (from))
6807 if (TREE_CODE (from) == OFFSET_TYPE
6808 && comptypes (TYPE_OFFSET_BASETYPE (to),
6809 TYPE_OFFSET_BASETYPE (from),
6810 COMPARE_BASE | COMPARE_DERIVED))
6813 if (TREE_CODE (to) == VECTOR_TYPE
6814 && vector_types_convertible_p (to, from, false))
6817 if (TREE_CODE (to) == INTEGER_TYPE
6818 && TYPE_PRECISION (to) == TYPE_PRECISION (from))
6821 if (TREE_CODE (to) == FUNCTION_TYPE)
6824 if (TREE_CODE (to) != POINTER_TYPE)
6826 (TYPE_MAIN_VARIANT (to), TYPE_MAIN_VARIANT (from),
6827 COMPARE_BASE | COMPARE_DERIVED);
6831 /* Return true if TO and FROM (both of which are POINTER_TYPEs or
6832 pointer-to-member types) are the same, ignoring cv-qualification at
6836 comp_ptr_ttypes_const (tree to, tree from)
6838 for (; ; to = TREE_TYPE (to), from = TREE_TYPE (from))
6840 if (TREE_CODE (to) != TREE_CODE (from))
6843 if (TREE_CODE (from) == OFFSET_TYPE
6844 && same_type_p (TYPE_OFFSET_BASETYPE (from),
6845 TYPE_OFFSET_BASETYPE (to)))
6848 if (TREE_CODE (to) != POINTER_TYPE)
6849 return same_type_ignoring_top_level_qualifiers_p (to, from);
6853 /* Returns the type qualifiers for this type, including the qualifiers on the
6854 elements for an array type. */
6857 cp_type_quals (tree type)
6859 type = strip_array_types (type);
6860 if (type == error_mark_node)
6861 return TYPE_UNQUALIFIED;
6862 return TYPE_QUALS (type);
6865 /* Returns nonzero if the TYPE contains a mutable member. */
6868 cp_has_mutable_p (tree type)
6870 type = strip_array_types (type);
6872 return CLASS_TYPE_P (type) && CLASSTYPE_HAS_MUTABLE (type);
6875 /* Apply the TYPE_QUALS to the new DECL. */
6877 cp_apply_type_quals_to_decl (int type_quals, tree decl)
6879 tree type = TREE_TYPE (decl);
6881 if (type == error_mark_node)
6884 if (TREE_CODE (type) == FUNCTION_TYPE
6885 && type_quals != TYPE_UNQUALIFIED)
6887 /* This was an error in C++98 (cv-qualifiers cannot be added to
6888 a function type), but DR 295 makes the code well-formed by
6889 dropping the extra qualifiers. */
6892 tree bad_type = build_qualified_type (type, type_quals);
6893 pedwarn ("ignoring %qV qualifiers added to function type %qT",
6897 TREE_TYPE (decl) = TYPE_MAIN_VARIANT (type);
6901 /* Avoid setting TREE_READONLY incorrectly. */
6902 if (/* If the object has a constructor, the constructor may modify
6904 TYPE_NEEDS_CONSTRUCTING (type)
6905 /* If the type isn't complete, we don't know yet if it will need
6907 || !COMPLETE_TYPE_P (type)
6908 /* If the type has a mutable component, that component might be
6910 || TYPE_HAS_MUTABLE_P (type))
6911 type_quals &= ~TYPE_QUAL_CONST;
6913 c_apply_type_quals_to_decl (type_quals, decl);
6916 /* Subroutine of casts_away_constness. Make T1 and T2 point at
6917 exemplar types such that casting T1 to T2 is casting away constness
6918 if and only if there is no implicit conversion from T1 to T2. */
6921 casts_away_constness_r (tree *t1, tree *t2)
6926 /* [expr.const.cast]
6928 For multi-level pointer to members and multi-level mixed pointers
6929 and pointers to members (conv.qual), the "member" aspect of a
6930 pointer to member level is ignored when determining if a const
6931 cv-qualifier has been cast away. */
6932 /* [expr.const.cast]
6934 For two pointer types:
6936 X1 is T1cv1,1 * ... cv1,N * where T1 is not a pointer type
6937 X2 is T2cv2,1 * ... cv2,M * where T2 is not a pointer type
6940 casting from X1 to X2 casts away constness if, for a non-pointer
6941 type T there does not exist an implicit conversion (clause
6944 Tcv1,(N-K+1) * cv1,(N-K+2) * ... cv1,N *
6948 Tcv2,(M-K+1) * cv2,(M-K+2) * ... cv2,M *. */
6949 if ((!TYPE_PTR_P (*t1) && !TYPE_PTRMEM_P (*t1))
6950 || (!TYPE_PTR_P (*t2) && !TYPE_PTRMEM_P (*t2)))
6952 *t1 = cp_build_qualified_type (void_type_node,
6953 cp_type_quals (*t1));
6954 *t2 = cp_build_qualified_type (void_type_node,
6955 cp_type_quals (*t2));
6959 quals1 = cp_type_quals (*t1);
6960 quals2 = cp_type_quals (*t2);
6962 if (TYPE_PTRMEM_P (*t1))
6963 *t1 = TYPE_PTRMEM_POINTED_TO_TYPE (*t1);
6965 *t1 = TREE_TYPE (*t1);
6966 if (TYPE_PTRMEM_P (*t2))
6967 *t2 = TYPE_PTRMEM_POINTED_TO_TYPE (*t2);
6969 *t2 = TREE_TYPE (*t2);
6971 casts_away_constness_r (t1, t2);
6972 *t1 = build_pointer_type (*t1);
6973 *t2 = build_pointer_type (*t2);
6974 *t1 = cp_build_qualified_type (*t1, quals1);
6975 *t2 = cp_build_qualified_type (*t2, quals2);
6978 /* Returns nonzero if casting from TYPE1 to TYPE2 casts away
6982 casts_away_constness (tree t1, tree t2)
6984 if (TREE_CODE (t2) == REFERENCE_TYPE)
6986 /* [expr.const.cast]
6988 Casting from an lvalue of type T1 to an lvalue of type T2
6989 using a reference cast casts away constness if a cast from an
6990 rvalue of type "pointer to T1" to the type "pointer to T2"
6991 casts away constness. */
6992 t1 = (TREE_CODE (t1) == REFERENCE_TYPE ? TREE_TYPE (t1) : t1);
6993 return casts_away_constness (build_pointer_type (t1),
6994 build_pointer_type (TREE_TYPE (t2)));
6997 if (TYPE_PTRMEM_P (t1) && TYPE_PTRMEM_P (t2))
6998 /* [expr.const.cast]
7000 Casting from an rvalue of type "pointer to data member of X
7001 of type T1" to the type "pointer to data member of Y of type
7002 T2" casts away constness if a cast from an rvalue of type
7003 "pointer to T1" to the type "pointer to T2" casts away
7005 return casts_away_constness
7006 (build_pointer_type (TYPE_PTRMEM_POINTED_TO_TYPE (t1)),
7007 build_pointer_type (TYPE_PTRMEM_POINTED_TO_TYPE (t2)));
7009 /* Casting away constness is only something that makes sense for
7010 pointer or reference types. */
7011 if (TREE_CODE (t1) != POINTER_TYPE
7012 || TREE_CODE (t2) != POINTER_TYPE)
7015 /* Top-level qualifiers don't matter. */
7016 t1 = TYPE_MAIN_VARIANT (t1);
7017 t2 = TYPE_MAIN_VARIANT (t2);
7018 casts_away_constness_r (&t1, &t2);
7019 if (!can_convert (t2, t1))
7025 /* If T is a REFERENCE_TYPE return the type to which T refers.
7026 Otherwise, return T itself. */
7029 non_reference (tree t)
7031 if (TREE_CODE (t) == REFERENCE_TYPE)
7037 /* Return nonzero if REF is an lvalue valid for this language;
7038 otherwise, print an error message and return zero. USE says
7039 how the lvalue is being used and so selects the error message. */
7042 lvalue_or_else (tree ref, enum lvalue_use use)
7044 int win = lvalue_p (ref);