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 Free Software Foundation, Inc.
4 Hacked by Michael Tiemann (tiemann@cygnus.com)
6 This file is part of GCC.
8 GCC is free software; you can redistribute it and/or modify
9 it under the terms of the GNU General Public License as published by
10 the Free Software Foundation; either version 2, or (at your option)
13 GCC is distributed in the hope that it will be useful,
14 but WITHOUT ANY WARRANTY; without even the implied warranty of
15 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 GNU General Public License for more details.
18 You should have received a copy of the GNU General Public License
19 along with GCC; see the file COPYING. If not, write to
20 the Free Software Foundation, 59 Temple Place - Suite 330,
21 Boston, MA 02111-1307, USA. */
24 /* This file is part of the C++ front end.
25 It contains routines to build C++ expressions given their operands,
26 including computing the types of the result, C and C++ specific error
27 checks, and some optimization. */
31 #include "coretypes.h"
41 #include "diagnostic.h"
46 static tree convert_for_assignment (tree, tree, const char *, tree, int);
47 static tree cp_pointer_int_sum (enum tree_code, tree, tree);
48 static tree rationalize_conditional_expr (enum tree_code, tree);
49 static int comp_ptr_ttypes_real (tree, tree, int);
50 static int comp_ptr_ttypes_const (tree, tree);
51 static bool comp_except_types (tree, tree, bool);
52 static bool comp_array_types (tree, tree, bool);
53 static tree common_base_type (tree, tree);
54 static tree pointer_diff (tree, tree, tree);
55 static tree get_delta_difference (tree, tree, bool, bool);
56 static void casts_away_constness_r (tree *, tree *);
57 static bool casts_away_constness (tree, tree);
58 static void maybe_warn_about_returning_address_of_local (tree);
59 static tree lookup_destructor (tree, tree, tree);
61 /* Return the target type of TYPE, which means return T for:
62 T*, T&, T[], T (...), and otherwise, just T. */
65 target_type (tree type)
67 type = non_reference (type);
68 while (TREE_CODE (type) == POINTER_TYPE
69 || TREE_CODE (type) == ARRAY_TYPE
70 || TREE_CODE (type) == FUNCTION_TYPE
71 || TREE_CODE (type) == METHOD_TYPE
72 || TYPE_PTRMEM_P (type))
73 type = TREE_TYPE (type);
77 /* Do `exp = require_complete_type (exp);' to make sure exp
78 does not have an incomplete type. (That includes void types.)
79 Returns the error_mark_node if the VALUE does not have
80 complete type when this function returns. */
83 require_complete_type (tree value)
87 if (processing_template_decl || value == error_mark_node)
90 if (TREE_CODE (value) == OVERLOAD)
91 type = unknown_type_node;
93 type = TREE_TYPE (value);
95 if (type == error_mark_node)
96 return error_mark_node;
98 /* First, detect a valid value with a complete type. */
99 if (COMPLETE_TYPE_P (type))
102 if (complete_type_or_else (type, value))
105 return error_mark_node;
108 /* Try to complete TYPE, if it is incomplete. For example, if TYPE is
109 a template instantiation, do the instantiation. Returns TYPE,
110 whether or not it could be completed, unless something goes
111 horribly wrong, in which case the error_mark_node is returned. */
114 complete_type (tree type)
116 if (type == NULL_TREE)
117 /* Rather than crash, we return something sure to cause an error
119 return error_mark_node;
121 if (type == error_mark_node || COMPLETE_TYPE_P (type))
123 else if (TREE_CODE (type) == ARRAY_TYPE && TYPE_DOMAIN (type))
125 tree t = complete_type (TREE_TYPE (type));
126 if (COMPLETE_TYPE_P (t) && !dependent_type_p (type))
128 TYPE_NEEDS_CONSTRUCTING (type)
129 = TYPE_NEEDS_CONSTRUCTING (TYPE_MAIN_VARIANT (t));
130 TYPE_HAS_NONTRIVIAL_DESTRUCTOR (type)
131 = TYPE_HAS_NONTRIVIAL_DESTRUCTOR (TYPE_MAIN_VARIANT (t));
133 else if (CLASS_TYPE_P (type) && CLASSTYPE_TEMPLATE_INSTANTIATION (type))
134 instantiate_class_template (TYPE_MAIN_VARIANT (type));
139 /* Like complete_type, but issue an error if the TYPE cannot be completed.
140 VALUE is used for informative diagnostics. DIAG_TYPE indicates the type
141 of diagnostic: 0 for an error, 1 for a warning, 2 for a pedwarn.
142 Returns NULL_TREE if the type cannot be made complete. */
145 complete_type_or_diagnostic (tree type, tree value, int diag_type)
147 type = complete_type (type);
148 if (type == error_mark_node)
149 /* We already issued an error. */
151 else if (!COMPLETE_TYPE_P (type))
153 cxx_incomplete_type_diagnostic (value, type, diag_type);
160 /* Return truthvalue of whether type of EXP is instantiated. */
163 type_unknown_p (tree exp)
165 return (TREE_CODE (exp) == TREE_LIST
166 || TREE_TYPE (exp) == unknown_type_node);
170 /* Return the common type of two parameter lists.
171 We assume that comptypes has already been done and returned 1;
172 if that isn't so, this may crash.
174 As an optimization, free the space we allocate if the parameter
175 lists are already common. */
178 commonparms (tree p1, tree p2)
180 tree oldargs = p1, newargs, n;
184 len = list_length (p1);
185 newargs = tree_last (p1);
187 if (newargs == void_list_node)
196 newargs = tree_cons (NULL_TREE, NULL_TREE, newargs);
201 p1 = TREE_CHAIN (p1), p2 = TREE_CHAIN (p2), n = TREE_CHAIN (n), i++)
203 if (TREE_PURPOSE (p1) && !TREE_PURPOSE (p2))
205 TREE_PURPOSE (n) = TREE_PURPOSE (p1);
208 else if (! TREE_PURPOSE (p1))
210 if (TREE_PURPOSE (p2))
212 TREE_PURPOSE (n) = TREE_PURPOSE (p2);
218 if (1 != simple_cst_equal (TREE_PURPOSE (p1), TREE_PURPOSE (p2)))
220 TREE_PURPOSE (n) = TREE_PURPOSE (p2);
222 if (TREE_VALUE (p1) != TREE_VALUE (p2))
225 TREE_VALUE (n) = merge_types (TREE_VALUE (p1), TREE_VALUE (p2));
228 TREE_VALUE (n) = TREE_VALUE (p1);
236 /* Given a type, perhaps copied for a typedef,
237 find the "original" version of it. */
239 original_type (tree t)
241 while (TYPE_NAME (t) != NULL_TREE)
243 tree x = TYPE_NAME (t);
244 if (TREE_CODE (x) != TYPE_DECL)
246 x = DECL_ORIGINAL_TYPE (x);
254 /* T1 and T2 are arithmetic or enumeration types. Return the type
255 that will result from the "usual arithmetic conversions" on T1 and
256 T2 as described in [expr]. */
259 type_after_usual_arithmetic_conversions (tree t1, tree t2)
261 enum tree_code code1 = TREE_CODE (t1);
262 enum tree_code code2 = TREE_CODE (t2);
265 /* FIXME: Attributes. */
266 gcc_assert (ARITHMETIC_TYPE_P (t1)
267 || TREE_CODE (t1) == COMPLEX_TYPE
268 || TREE_CODE (t1) == ENUMERAL_TYPE);
269 gcc_assert (ARITHMETIC_TYPE_P (t2)
270 || TREE_CODE (t2) == COMPLEX_TYPE
271 || TREE_CODE (t2) == ENUMERAL_TYPE);
273 /* In what follows, we slightly generalize the rules given in [expr] so
274 as to deal with `long long' and `complex'. First, merge the
276 attributes = (*targetm.merge_type_attributes) (t1, t2);
278 /* If one type is complex, form the common type of the non-complex
279 components, then make that complex. Use T1 or T2 if it is the
281 if (code1 == COMPLEX_TYPE || code2 == COMPLEX_TYPE)
283 tree subtype1 = code1 == COMPLEX_TYPE ? TREE_TYPE (t1) : t1;
284 tree subtype2 = code2 == COMPLEX_TYPE ? TREE_TYPE (t2) : t2;
286 = type_after_usual_arithmetic_conversions (subtype1, subtype2);
288 if (code1 == COMPLEX_TYPE && TREE_TYPE (t1) == subtype)
289 return build_type_attribute_variant (t1, attributes);
290 else if (code2 == COMPLEX_TYPE && TREE_TYPE (t2) == subtype)
291 return build_type_attribute_variant (t2, attributes);
293 return build_type_attribute_variant (build_complex_type (subtype),
297 /* If only one is real, use it as the result. */
298 if (code1 == REAL_TYPE && code2 != REAL_TYPE)
299 return build_type_attribute_variant (t1, attributes);
300 if (code2 == REAL_TYPE && code1 != REAL_TYPE)
301 return build_type_attribute_variant (t2, attributes);
303 /* Perform the integral promotions. */
304 if (code1 != REAL_TYPE)
306 t1 = type_promotes_to (t1);
307 t2 = type_promotes_to (t2);
310 /* Both real or both integers; use the one with greater precision. */
311 if (TYPE_PRECISION (t1) > TYPE_PRECISION (t2))
312 return build_type_attribute_variant (t1, attributes);
313 else if (TYPE_PRECISION (t2) > TYPE_PRECISION (t1))
314 return build_type_attribute_variant (t2, attributes);
316 /* The types are the same; no need to do anything fancy. */
317 if (TYPE_MAIN_VARIANT (t1) == TYPE_MAIN_VARIANT (t2))
318 return build_type_attribute_variant (t1, attributes);
320 if (code1 != REAL_TYPE)
322 /* If one is a sizetype, use it so size_binop doesn't blow up. */
323 if (TYPE_IS_SIZETYPE (t1) > TYPE_IS_SIZETYPE (t2))
324 return build_type_attribute_variant (t1, attributes);
325 if (TYPE_IS_SIZETYPE (t2) > TYPE_IS_SIZETYPE (t1))
326 return build_type_attribute_variant (t2, attributes);
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 /* [expr.eq] permits the application of a pointer conversion to
523 bring the pointers to a common type. */
524 if (TREE_CODE (t1) == POINTER_TYPE && TREE_CODE (t2) == POINTER_TYPE
525 && CLASS_TYPE_P (TREE_TYPE (t1))
526 && CLASS_TYPE_P (TREE_TYPE (t2))
527 && !same_type_ignoring_top_level_qualifiers_p (TREE_TYPE (t1),
530 class1 = TREE_TYPE (t1);
531 class2 = TREE_TYPE (t2);
533 if (DERIVED_FROM_P (class1, class2))
534 t2 = (build_pointer_type
535 (cp_build_qualified_type (class1, TYPE_QUALS (class2))));
536 else if (DERIVED_FROM_P (class2, class1))
537 t1 = (build_pointer_type
538 (cp_build_qualified_type (class2, TYPE_QUALS (class1))));
541 error ("%s between distinct pointer types %qT and %qT "
542 "lacks a cast", location, t1, t2);
543 return error_mark_node;
546 /* [expr.eq] permits the application of a pointer-to-member
547 conversion to change the class type of one of the types. */
548 else if (TYPE_PTR_TO_MEMBER_P (t1)
549 && !same_type_p (TYPE_PTRMEM_CLASS_TYPE (t1),
550 TYPE_PTRMEM_CLASS_TYPE (t2)))
552 class1 = TYPE_PTRMEM_CLASS_TYPE (t1);
553 class2 = TYPE_PTRMEM_CLASS_TYPE (t2);
555 if (DERIVED_FROM_P (class1, class2))
556 t1 = build_ptrmem_type (class2, TYPE_PTRMEM_POINTED_TO_TYPE (t1));
557 else if (DERIVED_FROM_P (class2, class1))
558 t2 = build_ptrmem_type (class1, TYPE_PTRMEM_POINTED_TO_TYPE (t2));
561 error ("%s between distinct pointer-to-member types %qT and %qT "
562 "lacks a cast", location, t1, t2);
563 return error_mark_node;
567 return composite_pointer_type_r (t1, t2, location);
570 /* Return the merged type of two types.
571 We assume that comptypes has already been done and returned 1;
572 if that isn't so, this may crash.
574 This just combines attributes and default arguments; any other
575 differences would cause the two types to compare unalike. */
578 merge_types (tree t1, tree t2)
580 enum tree_code code1;
581 enum tree_code code2;
584 /* Save time if the two types are the same. */
587 if (original_type (t1) == original_type (t2))
590 /* If one type is nonsense, use the other. */
591 if (t1 == error_mark_node)
593 if (t2 == error_mark_node)
596 /* Merge the attributes. */
597 attributes = (*targetm.merge_type_attributes) (t1, t2);
599 if (TYPE_PTRMEMFUNC_P (t1))
600 t1 = TYPE_PTRMEMFUNC_FN_TYPE (t1);
601 if (TYPE_PTRMEMFUNC_P (t2))
602 t2 = TYPE_PTRMEMFUNC_FN_TYPE (t2);
604 code1 = TREE_CODE (t1);
605 code2 = TREE_CODE (t2);
611 /* For two pointers, do this recursively on the target type. */
613 tree target = merge_types (TREE_TYPE (t1), TREE_TYPE (t2));
614 int quals = cp_type_quals (t1);
616 if (code1 == POINTER_TYPE)
617 t1 = build_pointer_type (target);
619 t1 = build_reference_type (target);
620 t1 = build_type_attribute_variant (t1, attributes);
621 t1 = cp_build_qualified_type (t1, quals);
623 if (TREE_CODE (target) == METHOD_TYPE)
624 t1 = build_ptrmemfunc_type (t1);
633 quals = cp_type_quals (t1);
634 pointee = merge_types (TYPE_PTRMEM_POINTED_TO_TYPE (t1),
635 TYPE_PTRMEM_POINTED_TO_TYPE (t2));
636 t1 = build_ptrmem_type (TYPE_PTRMEM_CLASS_TYPE (t1),
638 t1 = cp_build_qualified_type (t1, quals);
644 tree elt = merge_types (TREE_TYPE (t1), TREE_TYPE (t2));
645 /* Save space: see if the result is identical to one of the args. */
646 if (elt == TREE_TYPE (t1) && TYPE_DOMAIN (t1))
647 return build_type_attribute_variant (t1, attributes);
648 if (elt == TREE_TYPE (t2) && TYPE_DOMAIN (t2))
649 return build_type_attribute_variant (t2, attributes);
650 /* Merge the element types, and have a size if either arg has one. */
651 t1 = build_cplus_array_type
652 (elt, TYPE_DOMAIN (TYPE_DOMAIN (t1) ? t1 : t2));
657 /* Function types: prefer the one that specified arg types.
658 If both do, merge the arg types. Also merge the return types. */
660 tree valtype = merge_types (TREE_TYPE (t1), TREE_TYPE (t2));
661 tree p1 = TYPE_ARG_TYPES (t1);
662 tree p2 = TYPE_ARG_TYPES (t2);
665 /* Save space: see if the result is identical to one of the args. */
666 if (valtype == TREE_TYPE (t1) && ! p2)
667 return cp_build_type_attribute_variant (t1, attributes);
668 if (valtype == TREE_TYPE (t2) && ! p1)
669 return cp_build_type_attribute_variant (t2, attributes);
671 /* Simple way if one arg fails to specify argument types. */
672 if (p1 == NULL_TREE || TREE_VALUE (p1) == void_type_node)
674 rval = build_function_type (valtype, p2);
675 if ((raises = TYPE_RAISES_EXCEPTIONS (t2)))
676 rval = build_exception_variant (rval, raises);
677 return cp_build_type_attribute_variant (rval, attributes);
679 raises = TYPE_RAISES_EXCEPTIONS (t1);
680 if (p2 == NULL_TREE || TREE_VALUE (p2) == void_type_node)
682 rval = build_function_type (valtype, p1);
684 rval = build_exception_variant (rval, raises);
685 return cp_build_type_attribute_variant (rval, attributes);
688 rval = build_function_type (valtype, commonparms (p1, p2));
689 t1 = build_exception_variant (rval, raises);
695 /* Get this value the long way, since TYPE_METHOD_BASETYPE
696 is just the main variant of this. */
697 tree basetype = TREE_TYPE (TREE_VALUE (TYPE_ARG_TYPES (t2)));
698 tree raises = TYPE_RAISES_EXCEPTIONS (t1);
701 /* If this was a member function type, get back to the
702 original type of type member function (i.e., without
703 the class instance variable up front. */
704 t1 = build_function_type (TREE_TYPE (t1),
705 TREE_CHAIN (TYPE_ARG_TYPES (t1)));
706 t2 = build_function_type (TREE_TYPE (t2),
707 TREE_CHAIN (TYPE_ARG_TYPES (t2)));
708 t3 = merge_types (t1, t2);
709 t3 = build_method_type_directly (basetype, TREE_TYPE (t3),
710 TYPE_ARG_TYPES (t3));
711 t1 = build_exception_variant (t3, raises);
716 /* There is no need to merge attributes into a TYPENAME_TYPE.
717 When the type is instantiated it will have whatever
718 attributes result from the instantiation. */
723 return cp_build_type_attribute_variant (t1, attributes);
726 /* Return the common type of two types.
727 We assume that comptypes has already been done and returned 1;
728 if that isn't so, this may crash.
730 This is the type for the result of most arithmetic operations
731 if the operands have the given two types. */
734 common_type (tree t1, tree t2)
736 enum tree_code code1;
737 enum tree_code code2;
739 /* If one type is nonsense, bail. */
740 if (t1 == error_mark_node || t2 == error_mark_node)
741 return error_mark_node;
743 code1 = TREE_CODE (t1);
744 code2 = TREE_CODE (t2);
746 if ((ARITHMETIC_TYPE_P (t1) || code1 == ENUMERAL_TYPE
747 || code1 == COMPLEX_TYPE)
748 && (ARITHMETIC_TYPE_P (t2) || code2 == ENUMERAL_TYPE
749 || code2 == COMPLEX_TYPE))
750 return type_after_usual_arithmetic_conversions (t1, t2);
752 else if ((TYPE_PTR_P (t1) && TYPE_PTR_P (t2))
753 || (TYPE_PTRMEM_P (t1) && TYPE_PTRMEM_P (t2))
754 || (TYPE_PTRMEMFUNC_P (t1) && TYPE_PTRMEMFUNC_P (t2)))
755 return composite_pointer_type (t1, t2, error_mark_node, error_mark_node,
761 /* Compare two exception specifier types for exactness or subsetness, if
762 allowed. Returns false for mismatch, true for match (same, or
765 [except.spec] "If a class X ... objects of class X or any class publicly
766 and unambiguously derived from X. Similarly, if a pointer type Y * ...
767 exceptions of type Y * or that are pointers to any type publicly and
768 unambiguously derived from Y. Otherwise a function only allows exceptions
769 that have the same type ..."
770 This does not mention cv qualifiers and is different to what throw
771 [except.throw] and catch [except.catch] will do. They will ignore the
772 top level cv qualifiers, and allow qualifiers in the pointer to class
775 We implement the letter of the standard. */
778 comp_except_types (tree a, tree b, bool exact)
780 if (same_type_p (a, b))
784 if (cp_type_quals (a) || cp_type_quals (b))
787 if (TREE_CODE (a) == POINTER_TYPE
788 && TREE_CODE (b) == POINTER_TYPE)
792 if (cp_type_quals (a) || cp_type_quals (b))
796 if (TREE_CODE (a) != RECORD_TYPE
797 || TREE_CODE (b) != RECORD_TYPE)
800 if (PUBLICLY_UNIQUELY_DERIVED_P (a, b))
806 /* Return true if TYPE1 and TYPE2 are equivalent exception specifiers.
807 If EXACT is false, T2 can be stricter than T1 (according to 15.4/7),
808 otherwise it must be exact. Exception lists are unordered, but
809 we've already filtered out duplicates. Most lists will be in order,
810 we should try to make use of that. */
813 comp_except_specs (tree t1, tree t2, bool exact)
822 if (t1 == NULL_TREE) /* T1 is ... */
823 return t2 == NULL_TREE || !exact;
824 if (!TREE_VALUE (t1)) /* t1 is EMPTY */
825 return t2 != NULL_TREE && !TREE_VALUE (t2);
826 if (t2 == NULL_TREE) /* T2 is ... */
828 if (TREE_VALUE (t1) && !TREE_VALUE (t2)) /* T2 is EMPTY, T1 is not */
831 /* Neither set is ... or EMPTY, make sure each part of T2 is in T1.
832 Count how many we find, to determine exactness. For exact matching and
833 ordered T1, T2, this is an O(n) operation, otherwise its worst case is
835 for (base = t1; t2 != NULL_TREE; t2 = TREE_CHAIN (t2))
837 for (probe = base; probe != NULL_TREE; probe = TREE_CHAIN (probe))
839 tree a = TREE_VALUE (probe);
840 tree b = TREE_VALUE (t2);
842 if (comp_except_types (a, b, exact))
844 if (probe == base && exact)
845 base = TREE_CHAIN (probe);
850 if (probe == NULL_TREE)
853 return !exact || base == NULL_TREE || length == list_length (t1);
856 /* Compare the array types T1 and T2. ALLOW_REDECLARATION is true if
857 [] can match [size]. */
860 comp_array_types (tree t1, tree t2, bool allow_redeclaration)
869 /* The type of the array elements must be the same. */
870 if (!same_type_p (TREE_TYPE (t1), TREE_TYPE (t2)))
873 d1 = TYPE_DOMAIN (t1);
874 d2 = TYPE_DOMAIN (t2);
879 /* If one of the arrays is dimensionless, and the other has a
880 dimension, they are of different types. However, it is valid to
888 declarations for an array object can specify
889 array types that differ by the presence or absence of a major
890 array bound (_dcl.array_). */
892 return allow_redeclaration;
894 /* Check that the dimensions are the same. */
896 if (!cp_tree_equal (TYPE_MIN_VALUE (d1), TYPE_MIN_VALUE (d2)))
898 max1 = TYPE_MAX_VALUE (d1);
899 max2 = TYPE_MAX_VALUE (d2);
900 if (processing_template_decl && !abi_version_at_least (2)
901 && !value_dependent_expression_p (max1)
902 && !value_dependent_expression_p (max2))
904 /* With abi-1 we do not fold non-dependent array bounds, (and
905 consequently mangle them incorrectly). We must therefore
906 fold them here, to verify the domains have the same
912 if (!cp_tree_equal (max1, max2))
918 /* Return true if T1 and T2 are related as allowed by STRICT. STRICT
919 is a bitwise-or of the COMPARE_* flags. */
922 comptypes (tree t1, tree t2, int strict)
929 /* Suppress errors caused by previously reported errors. */
930 if (t1 == error_mark_node || t2 == error_mark_node)
933 gcc_assert (TYPE_P (t1) && TYPE_P (t2));
935 /* TYPENAME_TYPEs should be resolved if the qualifying scope is the
936 current instantiation. */
937 if (TREE_CODE (t1) == TYPENAME_TYPE)
939 tree resolved = resolve_typename_type (t1, /*only_current_p=*/true);
941 if (resolved != error_mark_node)
945 if (TREE_CODE (t2) == TYPENAME_TYPE)
947 tree resolved = resolve_typename_type (t2, /*only_current_p=*/true);
949 if (resolved != error_mark_node)
953 /* If either type is the internal version of sizetype, use the
955 if (TREE_CODE (t1) == INTEGER_TYPE && TYPE_IS_SIZETYPE (t1)
956 && TYPE_ORIG_SIZE_TYPE (t1))
957 t1 = TYPE_ORIG_SIZE_TYPE (t1);
959 if (TREE_CODE (t2) == INTEGER_TYPE && TYPE_IS_SIZETYPE (t2)
960 && TYPE_ORIG_SIZE_TYPE (t2))
961 t2 = TYPE_ORIG_SIZE_TYPE (t2);
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 if (!(*targetm.comp_type_attributes) (t1, t2))
991 switch (TREE_CODE (t1))
993 case TEMPLATE_TEMPLATE_PARM:
994 case BOUND_TEMPLATE_TEMPLATE_PARM:
995 if (TEMPLATE_TYPE_IDX (t1) != TEMPLATE_TYPE_IDX (t2)
996 || TEMPLATE_TYPE_LEVEL (t1) != TEMPLATE_TYPE_LEVEL (t2))
998 if (!comp_template_parms
999 (DECL_TEMPLATE_PARMS (TEMPLATE_TEMPLATE_PARM_TEMPLATE_DECL (t1)),
1000 DECL_TEMPLATE_PARMS (TEMPLATE_TEMPLATE_PARM_TEMPLATE_DECL (t2))))
1002 if (TREE_CODE (t1) == TEMPLATE_TEMPLATE_PARM)
1004 /* Don't check inheritance. */
1005 strict = COMPARE_STRICT;
1010 if (TYPE_TEMPLATE_INFO (t1) && TYPE_TEMPLATE_INFO (t2)
1011 && (TYPE_TI_TEMPLATE (t1) == TYPE_TI_TEMPLATE (t2)
1012 || TREE_CODE (t1) == BOUND_TEMPLATE_TEMPLATE_PARM)
1013 && comp_template_args (TYPE_TI_ARGS (t1), TYPE_TI_ARGS (t2)))
1016 if ((strict & COMPARE_BASE) && DERIVED_FROM_P (t1, t2))
1018 else if ((strict & COMPARE_DERIVED) && DERIVED_FROM_P (t2, t1))
1021 /* We may be dealing with Objective-C instances... */
1022 if (TREE_CODE (t1) == RECORD_TYPE
1023 && (retval = objc_comptypes (t1, t2, 0) >= 0))
1025 /* ...but fall through if we are not. */
1030 if (!comptypes (TYPE_OFFSET_BASETYPE (t1), TYPE_OFFSET_BASETYPE (t2),
1031 strict & ~COMPARE_REDECLARATION))
1033 return same_type_p (TREE_TYPE (t1), TREE_TYPE (t2));
1036 case REFERENCE_TYPE:
1037 return TYPE_MODE (t1) == TYPE_MODE (t2)
1038 && TYPE_REF_CAN_ALIAS_ALL (t1) == TYPE_REF_CAN_ALIAS_ALL (t2)
1039 && same_type_p (TREE_TYPE (t1), TREE_TYPE (t2));
1043 if (!same_type_p (TREE_TYPE (t1), TREE_TYPE (t2)))
1045 return compparms (TYPE_ARG_TYPES (t1), TYPE_ARG_TYPES (t2));
1048 /* Target types must match incl. qualifiers. */
1049 return comp_array_types (t1, t2, !!(strict & COMPARE_REDECLARATION));
1051 case TEMPLATE_TYPE_PARM:
1052 return (TEMPLATE_TYPE_IDX (t1) == TEMPLATE_TYPE_IDX (t2)
1053 && TEMPLATE_TYPE_LEVEL (t1) == TEMPLATE_TYPE_LEVEL (t2));
1056 if (!cp_tree_equal (TYPENAME_TYPE_FULLNAME (t1),
1057 TYPENAME_TYPE_FULLNAME (t2)))
1059 return same_type_p (TYPE_CONTEXT (t1), TYPE_CONTEXT (t2));
1061 case UNBOUND_CLASS_TEMPLATE:
1062 if (!cp_tree_equal (TYPE_IDENTIFIER (t1), TYPE_IDENTIFIER (t2)))
1064 return same_type_p (TYPE_CONTEXT (t1), TYPE_CONTEXT (t2));
1067 return same_type_p (TREE_TYPE (t1), TREE_TYPE (t2));
1070 return TYPE_VECTOR_SUBPARTS (t1) == TYPE_VECTOR_SUBPARTS (t2)
1071 && same_type_p (TREE_TYPE (t1), TREE_TYPE (t2));
1080 /* Returns 1 if TYPE1 is at least as qualified as TYPE2. */
1083 at_least_as_qualified_p (tree type1, tree type2)
1085 int q1 = cp_type_quals (type1);
1086 int q2 = cp_type_quals (type2);
1088 /* All qualifiers for TYPE2 must also appear in TYPE1. */
1089 return (q1 & q2) == q2;
1092 /* Returns 1 if TYPE1 is more qualified than TYPE2. */
1095 more_qualified_p (tree type1, tree type2)
1097 int q1 = cp_type_quals (type1);
1098 int q2 = cp_type_quals (type2);
1100 return q1 != q2 && (q1 & q2) == q2;
1103 /* Returns 1 if TYPE1 is more cv-qualified than TYPE2, -1 if TYPE2 is
1104 more cv-qualified that TYPE1, and 0 otherwise. */
1107 comp_cv_qualification (tree type1, tree type2)
1109 int q1 = cp_type_quals (type1);
1110 int q2 = cp_type_quals (type2);
1115 if ((q1 & q2) == q2)
1117 else if ((q1 & q2) == q1)
1123 /* Returns 1 if the cv-qualification signature of TYPE1 is a proper
1124 subset of the cv-qualification signature of TYPE2, and the types
1125 are similar. Returns -1 if the other way 'round, and 0 otherwise. */
1128 comp_cv_qual_signature (tree type1, tree type2)
1130 if (comp_ptr_ttypes_real (type2, type1, -1))
1132 else if (comp_ptr_ttypes_real (type1, type2, -1))
1138 /* If two types share a common base type, return that basetype.
1139 If there is not a unique most-derived base type, this function
1140 returns ERROR_MARK_NODE. */
1143 common_base_type (tree tt1, tree tt2)
1145 tree best = NULL_TREE;
1148 /* If one is a baseclass of another, that's good enough. */
1149 if (UNIQUELY_DERIVED_FROM_P (tt1, tt2))
1151 if (UNIQUELY_DERIVED_FROM_P (tt2, tt1))
1154 /* Otherwise, try to find a unique baseclass of TT1
1155 that is shared by TT2, and follow that down. */
1156 for (i = BINFO_N_BASE_BINFOS (TYPE_BINFO (tt1))-1; i >= 0; i--)
1158 tree basetype = BINFO_TYPE (BINFO_BASE_BINFO (TYPE_BINFO (tt1), i));
1159 tree trial = common_base_type (basetype, tt2);
1163 if (trial == error_mark_node)
1165 if (best == NULL_TREE)
1167 else if (best != trial)
1168 return error_mark_node;
1173 for (i = BINFO_N_BASE_BINFOS (TYPE_BINFO (tt2))-1; i >= 0; i--)
1175 tree basetype = BINFO_TYPE (BINFO_BASE_BINFO (TYPE_BINFO (tt2), i));
1176 tree trial = common_base_type (tt1, basetype);
1180 if (trial == error_mark_node)
1182 if (best == NULL_TREE)
1184 else if (best != trial)
1185 return error_mark_node;
1191 /* Subroutines of `comptypes'. */
1193 /* Return true if two parameter type lists PARMS1 and PARMS2 are
1194 equivalent in the sense that functions with those parameter types
1195 can have equivalent types. The two lists must be equivalent,
1196 element by element. */
1199 compparms (tree parms1, tree parms2)
1203 /* An unspecified parmlist matches any specified parmlist
1204 whose argument types don't need default promotions. */
1206 for (t1 = parms1, t2 = parms2;
1208 t1 = TREE_CHAIN (t1), t2 = TREE_CHAIN (t2))
1210 /* If one parmlist is shorter than the other,
1211 they fail to match. */
1214 if (!same_type_p (TREE_VALUE (t1), TREE_VALUE (t2)))
1221 /* Process a sizeof or alignof expression where the operand is a
1225 cxx_sizeof_or_alignof_type (tree type, enum tree_code op, bool complain)
1227 enum tree_code type_code;
1229 const char *op_name;
1231 gcc_assert (op == SIZEOF_EXPR || op == ALIGNOF_EXPR);
1232 if (type == error_mark_node)
1233 return error_mark_node;
1235 if (processing_template_decl)
1237 value = build_min (op, size_type_node, type);
1238 TREE_READONLY (value) = 1;
1242 op_name = operator_name_info[(int) op].name;
1244 type = non_reference (type);
1245 type_code = TREE_CODE (type);
1247 if (type_code == METHOD_TYPE)
1249 if (complain && (pedantic || warn_pointer_arith))
1250 pedwarn ("invalid application of %qs to a member function", op_name);
1251 value = size_one_node;
1254 value = c_sizeof_or_alignof_type (complete_type (type), op, complain);
1259 /* Process a sizeof or alignof expression where the operand is an
1263 cxx_sizeof_or_alignof_expr (tree e, enum tree_code op)
1265 const char *op_name = operator_name_info[(int) op].name;
1267 if (e == error_mark_node)
1268 return error_mark_node;
1270 if (processing_template_decl)
1272 e = build_min (op, size_type_node, e);
1273 TREE_SIDE_EFFECTS (e) = 0;
1274 TREE_READONLY (e) = 1;
1279 if (TREE_CODE (e) == COMPONENT_REF
1280 && TREE_CODE (TREE_OPERAND (e, 1)) == FIELD_DECL
1281 && DECL_C_BIT_FIELD (TREE_OPERAND (e, 1)))
1283 error ("invalid application of %qs to a bit-field", op_name);
1286 else if (is_overloaded_fn (e))
1288 pedwarn ("ISO C++ forbids applying %qs to an expression of "
1289 "function type", op_name);
1292 else if (type_unknown_p (e))
1294 cxx_incomplete_type_error (e, TREE_TYPE (e));
1300 return cxx_sizeof_or_alignof_type (e, op, true);
1304 /* EXPR is being used in a context that is not a function call.
1309 The expression can be used only as the left-hand operand of a
1310 member function call.
1312 [expr.mptr.operator]
1314 If the result of .* or ->* is a function, then that result can be
1315 used only as the operand for the function call operator ().
1317 by issuing an error message if appropriate. Returns true iff EXPR
1318 violates these rules. */
1321 invalid_nonstatic_memfn_p (tree expr)
1323 if (TREE_CODE (TREE_TYPE (expr)) == METHOD_TYPE)
1325 error ("invalid use of non-static member function");
1331 /* Perform the conversions in [expr] that apply when an lvalue appears
1332 in an rvalue context: the lvalue-to-rvalue, array-to-pointer, and
1333 function-to-pointer conversions.
1335 In addition manifest constants are replaced by their values. */
1338 decay_conversion (tree exp)
1341 enum tree_code code;
1343 type = TREE_TYPE (exp);
1344 code = TREE_CODE (type);
1346 if (type == error_mark_node)
1347 return error_mark_node;
1349 if (type_unknown_p (exp))
1351 cxx_incomplete_type_error (exp, TREE_TYPE (exp));
1352 return error_mark_node;
1355 exp = integral_constant_value (exp);
1357 /* build_c_cast puts on a NOP_EXPR to make the result not an lvalue.
1358 Leave such NOP_EXPRs, since RHS is being used in non-lvalue context. */
1360 if (code == VOID_TYPE)
1362 error ("void value not ignored as it ought to be");
1363 return error_mark_node;
1365 if (invalid_nonstatic_memfn_p (exp))
1366 return error_mark_node;
1367 if (code == FUNCTION_TYPE || is_overloaded_fn (exp))
1368 return build_unary_op (ADDR_EXPR, exp, 0);
1369 if (code == ARRAY_TYPE)
1374 if (TREE_CODE (exp) == INDIRECT_REF)
1375 return build_nop (build_pointer_type (TREE_TYPE (type)),
1376 TREE_OPERAND (exp, 0));
1378 if (TREE_CODE (exp) == COMPOUND_EXPR)
1380 tree op1 = decay_conversion (TREE_OPERAND (exp, 1));
1381 return build2 (COMPOUND_EXPR, TREE_TYPE (op1),
1382 TREE_OPERAND (exp, 0), op1);
1386 && ! (TREE_CODE (exp) == CONSTRUCTOR && TREE_STATIC (exp)))
1388 error ("invalid use of non-lvalue array");
1389 return error_mark_node;
1392 ptrtype = build_pointer_type (TREE_TYPE (type));
1394 if (TREE_CODE (exp) == VAR_DECL)
1396 if (!cxx_mark_addressable (exp))
1397 return error_mark_node;
1398 adr = build_nop (ptrtype, build_address (exp));
1401 /* This way is better for a COMPONENT_REF since it can
1402 simplify the offset for a component. */
1403 adr = build_unary_op (ADDR_EXPR, exp, 1);
1404 return cp_convert (ptrtype, adr);
1407 /* [basic.lval]: Class rvalues can have cv-qualified types; non-class
1408 rvalues always have cv-unqualified types. */
1409 if (! CLASS_TYPE_P (type))
1410 exp = cp_convert (TYPE_MAIN_VARIANT (type), exp);
1416 default_conversion (tree exp)
1418 exp = decay_conversion (exp);
1420 if (INTEGRAL_OR_ENUMERATION_TYPE_P (TREE_TYPE (exp)))
1421 exp = perform_integral_promotions (exp);
1426 /* EXPR is an expression with an integral or enumeration type.
1427 Perform the integral promotions in [conv.prom], and return the
1431 perform_integral_promotions (tree expr)
1436 type = TREE_TYPE (expr);
1437 gcc_assert (INTEGRAL_OR_ENUMERATION_TYPE_P (type));
1438 promoted_type = type_promotes_to (type);
1439 if (type != promoted_type)
1440 expr = cp_convert (promoted_type, expr);
1444 /* Take the address of an inline function without setting TREE_ADDRESSABLE
1448 inline_conversion (tree exp)
1450 if (TREE_CODE (exp) == FUNCTION_DECL)
1451 exp = build1 (ADDR_EXPR, build_pointer_type (TREE_TYPE (exp)), exp);
1456 /* Returns nonzero iff exp is a STRING_CST or the result of applying
1457 decay_conversion to one. */
1460 string_conv_p (tree totype, tree exp, int warn)
1464 if (! flag_const_strings || TREE_CODE (totype) != POINTER_TYPE)
1467 t = TREE_TYPE (totype);
1468 if (!same_type_p (t, char_type_node)
1469 && !same_type_p (t, wchar_type_node))
1472 if (TREE_CODE (exp) == STRING_CST)
1474 /* Make sure that we don't try to convert between char and wchar_t. */
1475 if (!same_type_p (TYPE_MAIN_VARIANT (TREE_TYPE (TREE_TYPE (exp))), t))
1480 /* Is this a string constant which has decayed to 'const char *'? */
1481 t = build_pointer_type (build_qualified_type (t, TYPE_QUAL_CONST));
1482 if (!same_type_p (TREE_TYPE (exp), t))
1485 if (TREE_CODE (exp) != ADDR_EXPR
1486 || TREE_CODE (TREE_OPERAND (exp, 0)) != STRING_CST)
1490 /* This warning is not very useful, as it complains about printf. */
1491 if (warn && warn_write_strings)
1492 warning ("deprecated conversion from string constant to %qT'", totype);
1497 /* Given a COND_EXPR, MIN_EXPR, or MAX_EXPR in T, return it in a form that we
1498 can, for example, use as an lvalue. This code used to be in
1499 unary_complex_lvalue, but we needed it to deal with `a = (d == c) ? b : c'
1500 expressions, where we're dealing with aggregates. But now it's again only
1501 called from unary_complex_lvalue. The case (in particular) that led to
1502 this was with CODE == ADDR_EXPR, since it's not an lvalue when we'd
1506 rationalize_conditional_expr (enum tree_code code, tree t)
1508 /* For MIN_EXPR or MAX_EXPR, fold-const.c has arranged things so that
1509 the first operand is always the one to be used if both operands
1510 are equal, so we know what conditional expression this used to be. */
1511 if (TREE_CODE (t) == MIN_EXPR || TREE_CODE (t) == MAX_EXPR)
1513 /* The following code is incorrect if either operand side-effects. */
1514 gcc_assert (!TREE_SIDE_EFFECTS (TREE_OPERAND (t, 0))
1515 && !TREE_SIDE_EFFECTS (TREE_OPERAND (t, 1)));
1517 build_conditional_expr (build_x_binary_op ((TREE_CODE (t) == MIN_EXPR
1518 ? LE_EXPR : GE_EXPR),
1519 TREE_OPERAND (t, 0),
1520 TREE_OPERAND (t, 1),
1521 /*overloaded_p=*/NULL),
1522 build_unary_op (code, TREE_OPERAND (t, 0), 0),
1523 build_unary_op (code, TREE_OPERAND (t, 1), 0));
1527 build_conditional_expr (TREE_OPERAND (t, 0),
1528 build_unary_op (code, TREE_OPERAND (t, 1), 0),
1529 build_unary_op (code, TREE_OPERAND (t, 2), 0));
1532 /* Given the TYPE of an anonymous union field inside T, return the
1533 FIELD_DECL for the field. If not found return NULL_TREE. Because
1534 anonymous unions can nest, we must also search all anonymous unions
1535 that are directly reachable. */
1538 lookup_anon_field (tree t, tree type)
1542 for (field = TYPE_FIELDS (t); field; field = TREE_CHAIN (field))
1544 if (TREE_STATIC (field))
1546 if (TREE_CODE (field) != FIELD_DECL || DECL_ARTIFICIAL (field))
1549 /* If we find it directly, return the field. */
1550 if (DECL_NAME (field) == NULL_TREE
1551 && type == TYPE_MAIN_VARIANT (TREE_TYPE (field)))
1556 /* Otherwise, it could be nested, search harder. */
1557 if (DECL_NAME (field) == NULL_TREE
1558 && ANON_AGGR_TYPE_P (TREE_TYPE (field)))
1560 tree subfield = lookup_anon_field (TREE_TYPE (field), type);
1568 /* Build an expression representing OBJECT.MEMBER. OBJECT is an
1569 expression; MEMBER is a DECL or baselink. If ACCESS_PATH is
1570 non-NULL, it indicates the path to the base used to name MEMBER.
1571 If PRESERVE_REFERENCE is true, the expression returned will have
1572 REFERENCE_TYPE if the MEMBER does. Otherwise, the expression
1573 returned will have the type referred to by the reference.
1575 This function does not perform access control; that is either done
1576 earlier by the parser when the name of MEMBER is resolved to MEMBER
1577 itself, or later when overload resolution selects one of the
1578 functions indicated by MEMBER. */
1581 build_class_member_access_expr (tree object, tree member,
1582 tree access_path, bool preserve_reference)
1586 tree result = NULL_TREE;
1588 if (object == error_mark_node || member == error_mark_node)
1589 return error_mark_node;
1591 if (TREE_CODE (member) == PSEUDO_DTOR_EXPR)
1594 gcc_assert (DECL_P (member) || BASELINK_P (member));
1598 The type of the first expression shall be "class object" (of a
1600 object_type = TREE_TYPE (object);
1601 if (!currently_open_class (object_type)
1602 && !complete_type_or_else (object_type, object))
1603 return error_mark_node;
1604 if (!CLASS_TYPE_P (object_type))
1606 error ("request for member %qD in %qE, which is of non-class type %qT",
1607 member, object, object_type);
1608 return error_mark_node;
1611 /* The standard does not seem to actually say that MEMBER must be a
1612 member of OBJECT_TYPE. However, that is clearly what is
1614 if (DECL_P (member))
1616 member_scope = DECL_CLASS_CONTEXT (member);
1618 if (TREE_DEPRECATED (member))
1619 warn_deprecated_use (member);
1622 member_scope = BINFO_TYPE (BASELINK_BINFO (member));
1623 /* If MEMBER is from an anonymous aggregate, MEMBER_SCOPE will
1624 presently be the anonymous union. Go outwards until we find a
1625 type related to OBJECT_TYPE. */
1626 while (ANON_AGGR_TYPE_P (member_scope)
1627 && !same_type_ignoring_top_level_qualifiers_p (member_scope,
1629 member_scope = TYPE_CONTEXT (member_scope);
1630 if (!member_scope || !DERIVED_FROM_P (member_scope, object_type))
1632 if (TREE_CODE (member) == FIELD_DECL)
1633 error ("invalid use of nonstatic data member %qE", member);
1635 error ("%qD is not a member of %qT", member, object_type);
1636 return error_mark_node;
1639 /* Transform `(a, b).x' into `(*(a, &b)).x', `(a ? b : c).x' into
1640 `(*(a ? &b : &c)).x', and so on. A COND_EXPR is only an lvalue
1641 in the frontend; only _DECLs and _REFs are lvalues in the backend. */
1643 tree temp = unary_complex_lvalue (ADDR_EXPR, object);
1645 object = build_indirect_ref (temp, NULL);
1648 /* In [expr.ref], there is an explicit list of the valid choices for
1649 MEMBER. We check for each of those cases here. */
1650 if (TREE_CODE (member) == VAR_DECL)
1652 /* A static data member. */
1654 /* If OBJECT has side-effects, they are supposed to occur. */
1655 if (TREE_SIDE_EFFECTS (object))
1656 result = build2 (COMPOUND_EXPR, TREE_TYPE (result), object, result);
1658 else if (TREE_CODE (member) == FIELD_DECL)
1660 /* A non-static data member. */
1665 null_object_p = (TREE_CODE (object) == INDIRECT_REF
1666 && integer_zerop (TREE_OPERAND (object, 0)));
1668 /* Convert OBJECT to the type of MEMBER. */
1669 if (!same_type_p (TYPE_MAIN_VARIANT (object_type),
1670 TYPE_MAIN_VARIANT (member_scope)))
1675 binfo = lookup_base (access_path ? access_path : object_type,
1676 member_scope, ba_unique, &kind);
1677 if (binfo == error_mark_node)
1678 return error_mark_node;
1680 /* It is invalid to try to get to a virtual base of a
1681 NULL object. The most common cause is invalid use of
1683 if (null_object_p && kind == bk_via_virtual)
1685 error ("invalid access to non-static data member %qD of "
1688 error ("(perhaps the %<offsetof%> macro was used incorrectly)");
1689 return error_mark_node;
1692 /* Convert to the base. */
1693 object = build_base_path (PLUS_EXPR, object, binfo,
1695 /* If we found the base successfully then we should be able
1696 to convert to it successfully. */
1697 gcc_assert (object != error_mark_node);
1700 /* Complain about other invalid uses of offsetof, even though they will
1701 give the right answer. Note that we complain whether or not they
1702 actually used the offsetof macro, since there's no way to know at this
1703 point. So we just give a warning, instead of a pedwarn. */
1704 /* Do not produce this warning for base class field references, because
1705 we know for a fact that didn't come from offsetof. This does occur
1706 in various testsuite cases where a null object is passed where a
1707 vtable access is required. */
1708 if (null_object_p && warn_invalid_offsetof
1709 && CLASSTYPE_NON_POD_P (object_type)
1710 && !DECL_FIELD_IS_BASE (member)
1711 && !skip_evaluation)
1713 warning ("invalid access to non-static data member %qD of NULL object",
1715 warning ("(perhaps the %<offsetof%> macro was used incorrectly)");
1718 /* If MEMBER is from an anonymous aggregate, we have converted
1719 OBJECT so that it refers to the class containing the
1720 anonymous union. Generate a reference to the anonymous union
1721 itself, and recur to find MEMBER. */
1722 if (ANON_AGGR_TYPE_P (DECL_CONTEXT (member))
1723 /* When this code is called from build_field_call, the
1724 object already has the type of the anonymous union.
1725 That is because the COMPONENT_REF was already
1726 constructed, and was then disassembled before calling
1727 build_field_call. After the function-call code is
1728 cleaned up, this waste can be eliminated. */
1729 && (!same_type_ignoring_top_level_qualifiers_p
1730 (TREE_TYPE (object), DECL_CONTEXT (member))))
1732 tree anonymous_union;
1734 anonymous_union = lookup_anon_field (TREE_TYPE (object),
1735 DECL_CONTEXT (member));
1736 object = build_class_member_access_expr (object,
1738 /*access_path=*/NULL_TREE,
1739 preserve_reference);
1742 /* Compute the type of the field, as described in [expr.ref]. */
1743 type_quals = TYPE_UNQUALIFIED;
1744 member_type = TREE_TYPE (member);
1745 if (TREE_CODE (member_type) != REFERENCE_TYPE)
1747 type_quals = (cp_type_quals (member_type)
1748 | cp_type_quals (object_type));
1750 /* A field is const (volatile) if the enclosing object, or the
1751 field itself, is const (volatile). But, a mutable field is
1752 not const, even within a const object. */
1753 if (DECL_MUTABLE_P (member))
1754 type_quals &= ~TYPE_QUAL_CONST;
1755 member_type = cp_build_qualified_type (member_type, type_quals);
1758 result = build3 (COMPONENT_REF, member_type, object, member,
1760 result = fold_if_not_in_template (result);
1762 /* Mark the expression const or volatile, as appropriate. Even
1763 though we've dealt with the type above, we still have to mark the
1764 expression itself. */
1765 if (type_quals & TYPE_QUAL_CONST)
1766 TREE_READONLY (result) = 1;
1767 else if (type_quals & TYPE_QUAL_VOLATILE)
1768 TREE_THIS_VOLATILE (result) = 1;
1770 else if (BASELINK_P (member))
1772 /* The member is a (possibly overloaded) member function. */
1776 /* If the MEMBER is exactly one static member function, then we
1777 know the type of the expression. Otherwise, we must wait
1778 until overload resolution has been performed. */
1779 functions = BASELINK_FUNCTIONS (member);
1780 if (TREE_CODE (functions) == FUNCTION_DECL
1781 && DECL_STATIC_FUNCTION_P (functions))
1782 type = TREE_TYPE (functions);
1784 type = unknown_type_node;
1785 /* Note that we do not convert OBJECT to the BASELINK_BINFO
1786 base. That will happen when the function is called. */
1787 result = build3 (COMPONENT_REF, type, object, member, NULL_TREE);
1789 else if (TREE_CODE (member) == CONST_DECL)
1791 /* The member is an enumerator. */
1793 /* If OBJECT has side-effects, they are supposed to occur. */
1794 if (TREE_SIDE_EFFECTS (object))
1795 result = build2 (COMPOUND_EXPR, TREE_TYPE (result),
1800 error ("invalid use of %qD", member);
1801 return error_mark_node;
1804 if (!preserve_reference)
1807 If E2 is declared to have type "reference to T", then ... the
1808 type of E1.E2 is T. */
1809 result = convert_from_reference (result);
1814 /* Return the destructor denoted by OBJECT.SCOPE::~DTOR_NAME, or, if
1815 SCOPE is NULL, by OBJECT.~DTOR_NAME. */
1818 lookup_destructor (tree object, tree scope, tree dtor_name)
1820 tree object_type = TREE_TYPE (object);
1821 tree dtor_type = TREE_OPERAND (dtor_name, 0);
1824 if (scope && !check_dtor_name (scope, dtor_name))
1826 error ("qualified type %qT does not match destructor name ~%qT",
1828 return error_mark_node;
1830 if (!DERIVED_FROM_P (dtor_type, TYPE_MAIN_VARIANT (object_type)))
1832 error ("the type being destroyed is %qT, but the destructor refers to %qT",
1833 TYPE_MAIN_VARIANT (object_type), dtor_type);
1834 return error_mark_node;
1836 if (!TYPE_HAS_DESTRUCTOR (dtor_type))
1837 return build3 (PSEUDO_DTOR_EXPR, void_type_node, object, scope,
1839 expr = lookup_member (dtor_type, complete_dtor_identifier,
1840 /*protect=*/1, /*want_type=*/false);
1841 expr = (adjust_result_of_qualified_name_lookup
1842 (expr, dtor_type, object_type));
1846 /* This function is called by the parser to process a class member
1847 access expression of the form OBJECT.NAME. NAME is a node used by
1848 the parser to represent a name; it is not yet a DECL. It may,
1849 however, be a BASELINK where the BASELINK_FUNCTIONS is a
1850 TEMPLATE_ID_EXPR. Templates must be looked up by the parser, and
1851 there is no reason to do the lookup twice, so the parser keeps the
1855 finish_class_member_access_expr (tree object, tree name)
1860 tree access_path = NULL_TREE;
1861 tree orig_object = object;
1862 tree orig_name = name;
1864 if (object == error_mark_node || name == error_mark_node)
1865 return error_mark_node;
1867 object_type = TREE_TYPE (object);
1869 if (processing_template_decl)
1871 if (/* If OBJECT_TYPE is dependent, so is OBJECT.NAME. */
1872 dependent_type_p (object_type)
1873 /* If NAME is just an IDENTIFIER_NODE, then the expression
1875 || TREE_CODE (object) == IDENTIFIER_NODE
1876 /* If NAME is "f<args>", where either 'f' or 'args' is
1877 dependent, then the expression is dependent. */
1878 || (TREE_CODE (name) == TEMPLATE_ID_EXPR
1879 && dependent_template_id_p (TREE_OPERAND (name, 0),
1880 TREE_OPERAND (name, 1)))
1881 /* If NAME is "T::X" where "T" is dependent, then the
1882 expression is dependent. */
1883 || (TREE_CODE (name) == SCOPE_REF
1884 && TYPE_P (TREE_OPERAND (name, 0))
1885 && dependent_type_p (TREE_OPERAND (name, 0))))
1886 return build_min_nt (COMPONENT_REF, object, name, NULL_TREE);
1887 object = build_non_dependent_expr (object);
1892 The type of the first expression shall be "class object" (of a
1894 if (!currently_open_class (object_type)
1895 && !complete_type_or_else (object_type, object))
1896 return error_mark_node;
1897 if (!CLASS_TYPE_P (object_type))
1899 error ("request for member %qD in %qE, which is of non-class type %qT",
1900 name, object, object_type);
1901 return error_mark_node;
1904 if (BASELINK_P (name))
1906 /* A member function that has already been looked up. */
1907 gcc_assert (TREE_CODE (BASELINK_FUNCTIONS (name)) == TEMPLATE_ID_EXPR);
1912 bool is_template_id = false;
1913 tree template_args = NULL_TREE;
1916 if (TREE_CODE (name) == TEMPLATE_ID_EXPR)
1918 is_template_id = true;
1919 template_args = TREE_OPERAND (name, 1);
1920 name = TREE_OPERAND (name, 0);
1922 if (TREE_CODE (name) == OVERLOAD)
1923 name = DECL_NAME (get_first_fn (name));
1924 else if (DECL_P (name))
1925 name = DECL_NAME (name);
1928 if (TREE_CODE (name) == SCOPE_REF)
1930 /* A qualified name. The qualifying class or namespace `S' has
1931 already been looked up; it is either a TYPE or a
1932 NAMESPACE_DECL. The member name is either an IDENTIFIER_NODE
1933 or a BIT_NOT_EXPR. */
1934 scope = TREE_OPERAND (name, 0);
1935 name = TREE_OPERAND (name, 1);
1936 gcc_assert (CLASS_TYPE_P (scope)
1937 || TREE_CODE (scope) == NAMESPACE_DECL);
1938 gcc_assert (TREE_CODE (name) == IDENTIFIER_NODE
1939 || TREE_CODE (name) == BIT_NOT_EXPR);
1941 /* If SCOPE is a namespace, then the qualified name does not
1942 name a member of OBJECT_TYPE. */
1943 if (TREE_CODE (scope) == NAMESPACE_DECL)
1945 error ("%<%D::%D%> is not a member of %qT",
1946 scope, name, object_type);
1947 return error_mark_node;
1950 /* Find the base of OBJECT_TYPE corresponding to SCOPE. */
1951 access_path = lookup_base (object_type, scope, ba_check, NULL);
1952 if (access_path == error_mark_node)
1953 return error_mark_node;
1956 error ("%qT is not a base of %qT", scope, object_type);
1957 return error_mark_node;
1963 access_path = object_type;
1966 if (TREE_CODE (name) == BIT_NOT_EXPR)
1967 member = lookup_destructor (object, scope, name);
1970 /* Look up the member. */
1971 member = lookup_member (access_path, name, /*protect=*/1,
1972 /*want_type=*/false);
1973 if (member == NULL_TREE)
1975 error ("%qD has no member named %qE", object_type, name);
1976 return error_mark_node;
1978 if (member == error_mark_node)
1979 return error_mark_node;
1984 tree template = member;
1986 if (BASELINK_P (template))
1987 template = lookup_template_function (template, template_args);
1990 error ("%qD is not a member template function", name);
1991 return error_mark_node;
1996 if (TREE_DEPRECATED (member))
1997 warn_deprecated_use (member);
1999 expr = build_class_member_access_expr (object, member, access_path,
2000 /*preserve_reference=*/false);
2001 if (processing_template_decl && expr != error_mark_node)
2002 return build_min_non_dep (COMPONENT_REF, expr,
2003 orig_object, orig_name, NULL_TREE);
2007 /* Return an expression for the MEMBER_NAME field in the internal
2008 representation of PTRMEM, a pointer-to-member function. (Each
2009 pointer-to-member function type gets its own RECORD_TYPE so it is
2010 more convenient to access the fields by name than by FIELD_DECL.)
2011 This routine converts the NAME to a FIELD_DECL and then creates the
2012 node for the complete expression. */
2015 build_ptrmemfunc_access_expr (tree ptrmem, tree member_name)
2021 /* This code is a stripped down version of
2022 build_class_member_access_expr. It does not work to use that
2023 routine directly because it expects the object to be of class
2025 ptrmem_type = TREE_TYPE (ptrmem);
2026 gcc_assert (TYPE_PTRMEMFUNC_P (ptrmem_type));
2027 member = lookup_member (ptrmem_type, member_name, /*protect=*/0,
2028 /*want_type=*/false);
2029 member_type = cp_build_qualified_type (TREE_TYPE (member),
2030 cp_type_quals (ptrmem_type));
2031 return fold (build3 (COMPONENT_REF, member_type,
2032 ptrmem, member, NULL_TREE));
2035 /* Given an expression PTR for a pointer, return an expression
2036 for the value pointed to.
2037 ERRORSTRING is the name of the operator to appear in error messages.
2039 This function may need to overload OPERATOR_FNNAME.
2040 Must also handle REFERENCE_TYPEs for C++. */
2043 build_x_indirect_ref (tree expr, const char *errorstring)
2045 tree orig_expr = expr;
2048 if (processing_template_decl)
2050 if (type_dependent_expression_p (expr))
2051 return build_min_nt (INDIRECT_REF, expr);
2052 expr = build_non_dependent_expr (expr);
2055 rval = build_new_op (INDIRECT_REF, LOOKUP_NORMAL, expr, NULL_TREE,
2056 NULL_TREE, /*overloaded_p=*/NULL);
2058 rval = build_indirect_ref (expr, errorstring);
2060 if (processing_template_decl && rval != error_mark_node)
2061 return build_min_non_dep (INDIRECT_REF, rval, orig_expr);
2067 build_indirect_ref (tree ptr, const char *errorstring)
2071 if (ptr == error_mark_node)
2072 return error_mark_node;
2074 if (ptr == current_class_ptr)
2075 return current_class_ref;
2077 pointer = (TREE_CODE (TREE_TYPE (ptr)) == REFERENCE_TYPE
2078 ? ptr : decay_conversion (ptr));
2079 type = TREE_TYPE (pointer);
2081 if (POINTER_TYPE_P (type))
2085 If the type of the expression is "pointer to T," the type
2086 of the result is "T."
2088 We must use the canonical variant because certain parts of
2089 the back end, like fold, do pointer comparisons between
2091 tree t = canonical_type_variant (TREE_TYPE (type));
2093 if (VOID_TYPE_P (t))
2095 /* A pointer to incomplete type (other than cv void) can be
2096 dereferenced [expr.unary.op]/1 */
2097 error ("%qT is not a pointer-to-object type", type);
2098 return error_mark_node;
2100 else if (TREE_CODE (pointer) == ADDR_EXPR
2101 && same_type_p (t, TREE_TYPE (TREE_OPERAND (pointer, 0))))
2102 /* The POINTER was something like `&x'. We simplify `*&x' to
2104 return TREE_OPERAND (pointer, 0);
2107 tree ref = build1 (INDIRECT_REF, t, pointer);
2109 /* We *must* set TREE_READONLY when dereferencing a pointer to const,
2110 so that we get the proper error message if the result is used
2111 to assign to. Also, &* is supposed to be a no-op. */
2112 TREE_READONLY (ref) = CP_TYPE_CONST_P (t);
2113 TREE_THIS_VOLATILE (ref) = CP_TYPE_VOLATILE_P (t);
2114 TREE_SIDE_EFFECTS (ref)
2115 = (TREE_THIS_VOLATILE (ref) || TREE_SIDE_EFFECTS (pointer));
2119 /* `pointer' won't be an error_mark_node if we were given a
2120 pointer to member, so it's cool to check for this here. */
2121 else if (TYPE_PTR_TO_MEMBER_P (type))
2122 error ("invalid use of %qs on pointer to member", errorstring);
2123 else if (pointer != error_mark_node)
2126 error ("invalid type argument of %qs", errorstring);
2128 error ("invalid type argument");
2130 return error_mark_node;
2133 /* This handles expressions of the form "a[i]", which denotes
2136 This is logically equivalent in C to *(a+i), but we may do it differently.
2137 If A is a variable or a member, we generate a primitive ARRAY_REF.
2138 This avoids forcing the array out of registers, and can work on
2139 arrays that are not lvalues (for example, members of structures returned
2142 If INDEX is of some user-defined type, it must be converted to
2143 integer type. Otherwise, to make a compatible PLUS_EXPR, it
2144 will inherit the type of the array, which will be some pointer type. */
2147 build_array_ref (tree array, tree idx)
2151 error ("subscript missing in array reference");
2152 return error_mark_node;
2155 if (TREE_TYPE (array) == error_mark_node
2156 || TREE_TYPE (idx) == error_mark_node)
2157 return error_mark_node;
2159 /* If ARRAY is a COMPOUND_EXPR or COND_EXPR, move our reference
2161 switch (TREE_CODE (array))
2165 tree value = build_array_ref (TREE_OPERAND (array, 1), idx);
2166 return build2 (COMPOUND_EXPR, TREE_TYPE (value),
2167 TREE_OPERAND (array, 0), value);
2171 return build_conditional_expr
2172 (TREE_OPERAND (array, 0),
2173 build_array_ref (TREE_OPERAND (array, 1), idx),
2174 build_array_ref (TREE_OPERAND (array, 2), idx));
2180 if (TREE_CODE (TREE_TYPE (array)) == ARRAY_TYPE)
2184 /* Subscripting with type char is likely to lose
2185 on a machine where chars are signed.
2186 So warn on any machine, but optionally.
2187 Don't warn for unsigned char since that type is safe.
2188 Don't warn for signed char because anyone who uses that
2189 must have done so deliberately. */
2190 if (warn_char_subscripts
2191 && TYPE_MAIN_VARIANT (TREE_TYPE (idx)) == char_type_node)
2192 warning ("array subscript has type %<char%>");
2194 if (!INTEGRAL_OR_ENUMERATION_TYPE_P (TREE_TYPE (idx)))
2196 error ("array subscript is not an integer");
2197 return error_mark_node;
2200 /* Apply integral promotions *after* noticing character types.
2201 (It is unclear why we do these promotions -- the standard
2202 does not say that we should. In fact, the natual thing would
2203 seem to be to convert IDX to ptrdiff_t; we're performing
2204 pointer arithmetic.) */
2205 idx = perform_integral_promotions (idx);
2207 /* An array that is indexed by a non-constant
2208 cannot be stored in a register; we must be able to do
2209 address arithmetic on its address.
2210 Likewise an array of elements of variable size. */
2211 if (TREE_CODE (idx) != INTEGER_CST
2212 || (COMPLETE_TYPE_P (TREE_TYPE (TREE_TYPE (array)))
2213 && (TREE_CODE (TYPE_SIZE (TREE_TYPE (TREE_TYPE (array))))
2216 if (!cxx_mark_addressable (array))
2217 return error_mark_node;
2220 /* An array that is indexed by a constant value which is not within
2221 the array bounds cannot be stored in a register either; because we
2222 would get a crash in store_bit_field/extract_bit_field when trying
2223 to access a non-existent part of the register. */
2224 if (TREE_CODE (idx) == INTEGER_CST
2225 && TYPE_DOMAIN (TREE_TYPE (array))
2226 && ! int_fits_type_p (idx, TYPE_DOMAIN (TREE_TYPE (array))))
2228 if (!cxx_mark_addressable (array))
2229 return error_mark_node;
2232 if (pedantic && !lvalue_p (array))
2233 pedwarn ("ISO C++ forbids subscripting non-lvalue array");
2235 /* Note in C++ it is valid to subscript a `register' array, since
2236 it is valid to take the address of something with that
2237 storage specification. */
2241 while (TREE_CODE (foo) == COMPONENT_REF)
2242 foo = TREE_OPERAND (foo, 0);
2243 if (TREE_CODE (foo) == VAR_DECL && DECL_REGISTER (foo))
2244 warning ("subscripting array declared %<register%>");
2247 type = TREE_TYPE (TREE_TYPE (array));
2248 rval = build4 (ARRAY_REF, type, array, idx, NULL_TREE, NULL_TREE);
2249 /* Array ref is const/volatile if the array elements are
2250 or if the array is.. */
2251 TREE_READONLY (rval)
2252 |= (CP_TYPE_CONST_P (type) | TREE_READONLY (array));
2253 TREE_SIDE_EFFECTS (rval)
2254 |= (CP_TYPE_VOLATILE_P (type) | TREE_SIDE_EFFECTS (array));
2255 TREE_THIS_VOLATILE (rval)
2256 |= (CP_TYPE_VOLATILE_P (type) | TREE_THIS_VOLATILE (array));
2257 return require_complete_type (fold_if_not_in_template (rval));
2261 tree ar = default_conversion (array);
2262 tree ind = default_conversion (idx);
2264 /* Put the integer in IND to simplify error checking. */
2265 if (TREE_CODE (TREE_TYPE (ar)) == INTEGER_TYPE)
2272 if (ar == error_mark_node)
2275 if (TREE_CODE (TREE_TYPE (ar)) != POINTER_TYPE)
2277 error ("subscripted value is neither array nor pointer");
2278 return error_mark_node;
2280 if (TREE_CODE (TREE_TYPE (ind)) != INTEGER_TYPE)
2282 error ("array subscript is not an integer");
2283 return error_mark_node;
2286 return build_indirect_ref (cp_build_binary_op (PLUS_EXPR, ar, ind),
2291 /* Resolve a pointer to member function. INSTANCE is the object
2292 instance to use, if the member points to a virtual member.
2294 This used to avoid checking for virtual functions if basetype
2295 has no virtual functions, according to an earlier ANSI draft.
2296 With the final ISO C++ rules, such an optimization is
2297 incorrect: A pointer to a derived member can be static_cast
2298 to pointer-to-base-member, as long as the dynamic object
2299 later has the right member. */
2302 get_member_function_from_ptrfunc (tree *instance_ptrptr, tree function)
2304 if (TREE_CODE (function) == OFFSET_REF)
2305 function = TREE_OPERAND (function, 1);
2307 if (TYPE_PTRMEMFUNC_P (TREE_TYPE (function)))
2309 tree idx, delta, e1, e2, e3, vtbl, basetype;
2310 tree fntype = TYPE_PTRMEMFUNC_FN_TYPE (TREE_TYPE (function));
2312 tree instance_ptr = *instance_ptrptr;
2313 tree instance_save_expr = 0;
2314 if (instance_ptr == error_mark_node)
2316 if (TREE_CODE (function) == PTRMEM_CST)
2318 /* Extracting the function address from a pmf is only
2319 allowed with -Wno-pmf-conversions. It only works for
2321 e1 = build_addr_func (PTRMEM_CST_MEMBER (function));
2322 e1 = convert (fntype, e1);
2327 error ("object missing in use of %qE", function);
2328 return error_mark_node;
2332 if (TREE_SIDE_EFFECTS (instance_ptr))
2333 instance_ptr = instance_save_expr = save_expr (instance_ptr);
2335 if (TREE_SIDE_EFFECTS (function))
2336 function = save_expr (function);
2338 /* Start by extracting all the information from the PMF itself. */
2339 e3 = PFN_FROM_PTRMEMFUNC (function);
2340 delta = build_ptrmemfunc_access_expr (function, delta_identifier);
2341 idx = build1 (NOP_EXPR, vtable_index_type, e3);
2342 switch (TARGET_PTRMEMFUNC_VBIT_LOCATION)
2344 case ptrmemfunc_vbit_in_pfn:
2345 e1 = cp_build_binary_op (BIT_AND_EXPR, idx, integer_one_node);
2346 idx = cp_build_binary_op (MINUS_EXPR, idx, integer_one_node);
2349 case ptrmemfunc_vbit_in_delta:
2350 e1 = cp_build_binary_op (BIT_AND_EXPR, delta, integer_one_node);
2351 delta = cp_build_binary_op (RSHIFT_EXPR, delta, integer_one_node);
2358 /* Convert down to the right base before using the instance. First
2360 basetype = TYPE_METHOD_BASETYPE (TREE_TYPE (fntype));
2361 basetype = lookup_base (TREE_TYPE (TREE_TYPE (instance_ptr)),
2362 basetype, ba_check, NULL);
2363 instance_ptr = build_base_path (PLUS_EXPR, instance_ptr, basetype, 1);
2364 if (instance_ptr == error_mark_node)
2365 return error_mark_node;
2366 /* ...and then the delta in the PMF. */
2367 instance_ptr = build2 (PLUS_EXPR, TREE_TYPE (instance_ptr),
2368 instance_ptr, delta);
2370 /* Hand back the adjusted 'this' argument to our caller. */
2371 *instance_ptrptr = instance_ptr;
2373 /* Next extract the vtable pointer from the object. */
2374 vtbl = build1 (NOP_EXPR, build_pointer_type (vtbl_ptr_type_node),
2376 vtbl = build_indirect_ref (vtbl, NULL);
2378 /* Finally, extract the function pointer from the vtable. */
2379 e2 = fold (build2 (PLUS_EXPR, TREE_TYPE (vtbl), vtbl, idx));
2380 e2 = build_indirect_ref (e2, NULL);
2381 TREE_CONSTANT (e2) = 1;
2382 TREE_INVARIANT (e2) = 1;
2384 /* When using function descriptors, the address of the
2385 vtable entry is treated as a function pointer. */
2386 if (TARGET_VTABLE_USES_DESCRIPTORS)
2387 e2 = build1 (NOP_EXPR, TREE_TYPE (e2),
2388 build_unary_op (ADDR_EXPR, e2, /*noconvert=*/1));
2390 TREE_TYPE (e2) = TREE_TYPE (e3);
2391 e1 = build_conditional_expr (e1, e2, e3);
2393 /* Make sure this doesn't get evaluated first inside one of the
2394 branches of the COND_EXPR. */
2395 if (instance_save_expr)
2396 e1 = build2 (COMPOUND_EXPR, TREE_TYPE (e1),
2397 instance_save_expr, e1);
2405 build_function_call (tree function, tree params)
2407 tree fntype, fndecl;
2408 tree coerced_params;
2409 tree name = NULL_TREE;
2411 tree original = function;
2413 /* build_c_cast puts on a NOP_EXPR to make the result not an lvalue.
2414 Strip such NOP_EXPRs, since FUNCTION is used in non-lvalue context. */
2415 if (TREE_CODE (function) == NOP_EXPR
2416 && TREE_TYPE (function) == TREE_TYPE (TREE_OPERAND (function, 0)))
2417 function = TREE_OPERAND (function, 0);
2419 if (TREE_CODE (function) == FUNCTION_DECL)
2421 name = DECL_NAME (function);
2423 mark_used (function);
2426 /* Convert anything with function type to a pointer-to-function. */
2427 if (pedantic && DECL_MAIN_P (function))
2428 pedwarn ("ISO C++ forbids calling %<::main%> from within program");
2430 /* Differs from default_conversion by not setting TREE_ADDRESSABLE
2431 (because calling an inline function does not mean the function
2432 needs to be separately compiled). */
2434 if (DECL_INLINE (function))
2435 function = inline_conversion (function);
2437 function = build_addr_func (function);
2443 function = build_addr_func (function);
2446 if (function == error_mark_node)
2447 return error_mark_node;
2449 fntype = TREE_TYPE (function);
2451 if (TYPE_PTRMEMFUNC_P (fntype))
2453 error ("must use %<.*%> or %<->*%> to call pointer-to-member "
2454 "function in %<%E (...)%>",
2456 return error_mark_node;
2459 is_method = (TREE_CODE (fntype) == POINTER_TYPE
2460 && TREE_CODE (TREE_TYPE (fntype)) == METHOD_TYPE);
2462 if (!((TREE_CODE (fntype) == POINTER_TYPE
2463 && TREE_CODE (TREE_TYPE (fntype)) == FUNCTION_TYPE)
2465 || TREE_CODE (function) == TEMPLATE_ID_EXPR))
2467 error ("%qE cannot be used as a function", original);
2468 return error_mark_node;
2471 /* fntype now gets the type of function pointed to. */
2472 fntype = TREE_TYPE (fntype);
2474 /* Convert the parameters to the types declared in the
2475 function prototype, or apply default promotions. */
2477 coerced_params = convert_arguments (TYPE_ARG_TYPES (fntype),
2478 params, fndecl, LOOKUP_NORMAL);
2479 if (coerced_params == error_mark_node)
2480 return error_mark_node;
2482 /* Check for errors in format strings and inappropriately
2485 check_function_arguments (TYPE_ATTRIBUTES (fntype), coerced_params);
2487 return build_cxx_call (function, coerced_params);
2490 /* Convert the actual parameter expressions in the list VALUES
2491 to the types in the list TYPELIST.
2492 If parmdecls is exhausted, or when an element has NULL as its type,
2493 perform the default conversions.
2495 NAME is an IDENTIFIER_NODE or 0. It is used only for error messages.
2497 This is also where warnings about wrong number of args are generated.
2499 Return a list of expressions for the parameters as converted.
2501 Both VALUES and the returned value are chains of TREE_LIST nodes
2502 with the elements of the list in the TREE_VALUE slots of those nodes.
2504 In C++, unspecified trailing parameters can be filled in with their
2505 default arguments, if such were specified. Do so here. */
2508 convert_arguments (tree typelist, tree values, tree fndecl, int flags)
2510 tree typetail, valtail;
2511 tree result = NULL_TREE;
2512 const char *called_thing = 0;
2515 /* Argument passing is always copy-initialization. */
2516 flags |= LOOKUP_ONLYCONVERTING;
2520 if (TREE_CODE (TREE_TYPE (fndecl)) == METHOD_TYPE)
2522 if (DECL_NAME (fndecl) == NULL_TREE
2523 || IDENTIFIER_HAS_TYPE_VALUE (DECL_NAME (fndecl)))
2524 called_thing = "constructor";
2526 called_thing = "member function";
2529 called_thing = "function";
2532 for (valtail = values, typetail = typelist;
2534 valtail = TREE_CHAIN (valtail), i++)
2536 tree type = typetail ? TREE_VALUE (typetail) : 0;
2537 tree val = TREE_VALUE (valtail);
2539 if (val == error_mark_node)
2540 return error_mark_node;
2542 if (type == void_type_node)
2546 cp_error_at ("too many arguments to %s %q+#D", called_thing,
2548 error ("at this point in file");
2551 error ("too many arguments to function");
2552 /* In case anybody wants to know if this argument
2555 TREE_TYPE (tree_last (result)) = error_mark_node;
2559 /* build_c_cast puts on a NOP_EXPR to make the result not an lvalue.
2560 Strip such NOP_EXPRs, since VAL is used in non-lvalue context. */
2561 if (TREE_CODE (val) == NOP_EXPR
2562 && TREE_TYPE (val) == TREE_TYPE (TREE_OPERAND (val, 0))
2563 && (type == 0 || TREE_CODE (type) != REFERENCE_TYPE))
2564 val = TREE_OPERAND (val, 0);
2566 if (type == 0 || TREE_CODE (type) != REFERENCE_TYPE)
2568 if (TREE_CODE (TREE_TYPE (val)) == ARRAY_TYPE
2569 || TREE_CODE (TREE_TYPE (val)) == FUNCTION_TYPE
2570 || TREE_CODE (TREE_TYPE (val)) == METHOD_TYPE)
2571 val = decay_conversion (val);
2574 if (val == error_mark_node)
2575 return error_mark_node;
2579 /* Formal parm type is specified by a function prototype. */
2582 if (!COMPLETE_TYPE_P (complete_type (type)))
2585 error ("parameter %P of %qD has incomplete type %qT",
2588 error ("parameter %P has incomplete type %qT", i, type);
2589 parmval = error_mark_node;
2593 parmval = convert_for_initialization
2594 (NULL_TREE, type, val, flags,
2595 "argument passing", fndecl, i);
2596 parmval = convert_for_arg_passing (type, parmval);
2599 if (parmval == error_mark_node)
2600 return error_mark_node;
2602 result = tree_cons (NULL_TREE, parmval, result);
2606 if (fndecl && DECL_BUILT_IN (fndecl)
2607 && DECL_FUNCTION_CODE (fndecl) == BUILT_IN_CONSTANT_P)
2608 /* Don't do ellipsis conversion for __built_in_constant_p
2609 as this will result in spurious warnings for non-POD
2611 val = require_complete_type (val);
2613 val = convert_arg_to_ellipsis (val);
2615 result = tree_cons (NULL_TREE, val, result);
2619 typetail = TREE_CHAIN (typetail);
2622 if (typetail != 0 && typetail != void_list_node)
2624 /* See if there are default arguments that can be used. */
2625 if (TREE_PURPOSE (typetail)
2626 && TREE_CODE (TREE_PURPOSE (typetail)) != DEFAULT_ARG)
2628 for (; typetail != void_list_node; ++i)
2631 = convert_default_arg (TREE_VALUE (typetail),
2632 TREE_PURPOSE (typetail),
2635 if (parmval == error_mark_node)
2636 return error_mark_node;
2638 result = tree_cons (0, parmval, result);
2639 typetail = TREE_CHAIN (typetail);
2640 /* ends with `...'. */
2641 if (typetail == NULL_TREE)
2649 cp_error_at ("too few arguments to %s %q+#D",
2650 called_thing, fndecl);
2651 error ("at this point in file");
2654 error ("too few arguments to function");
2655 return error_mark_list;
2659 return nreverse (result);
2662 /* Build a binary-operation expression, after performing default
2663 conversions on the operands. CODE is the kind of expression to build. */
2666 build_x_binary_op (enum tree_code code, tree arg1, tree arg2,
2676 if (processing_template_decl)
2678 if (type_dependent_expression_p (arg1)
2679 || type_dependent_expression_p (arg2))
2680 return build_min_nt (code, arg1, arg2);
2681 arg1 = build_non_dependent_expr (arg1);
2682 arg2 = build_non_dependent_expr (arg2);
2685 if (code == DOTSTAR_EXPR)
2686 expr = build_m_component_ref (arg1, arg2);
2688 expr = build_new_op (code, LOOKUP_NORMAL, arg1, arg2, NULL_TREE,
2691 if (processing_template_decl && expr != error_mark_node)
2692 return build_min_non_dep (code, expr, orig_arg1, orig_arg2);
2697 /* Build a binary-operation expression without default conversions.
2698 CODE is the kind of expression to build.
2699 This function differs from `build' in several ways:
2700 the data type of the result is computed and recorded in it,
2701 warnings are generated if arg data types are invalid,
2702 special handling for addition and subtraction of pointers is known,
2703 and some optimization is done (operations on narrow ints
2704 are done in the narrower type when that gives the same result).
2705 Constant folding is also done before the result is returned.
2707 Note that the operands will never have enumeral types
2708 because either they have just had the default conversions performed
2709 or they have both just been converted to some other type in which
2710 the arithmetic is to be done.
2712 C++: must do special pointer arithmetic when implementing
2713 multiple inheritance, and deal with pointer to member functions. */
2716 build_binary_op (enum tree_code code, tree orig_op0, tree orig_op1,
2717 int convert_p ATTRIBUTE_UNUSED)
2720 enum tree_code code0, code1;
2723 /* Expression code to give to the expression when it is built.
2724 Normally this is CODE, which is what the caller asked for,
2725 but in some special cases we change it. */
2726 enum tree_code resultcode = code;
2728 /* Data type in which the computation is to be performed.
2729 In the simplest cases this is the common type of the arguments. */
2730 tree result_type = NULL;
2732 /* Nonzero means operands have already been type-converted
2733 in whatever way is necessary.
2734 Zero means they need to be converted to RESULT_TYPE. */
2737 /* Nonzero means create the expression with this type, rather than
2739 tree build_type = 0;
2741 /* Nonzero means after finally constructing the expression
2742 convert it to this type. */
2743 tree final_type = 0;
2747 /* Nonzero if this is an operation like MIN or MAX which can
2748 safely be computed in short if both args are promoted shorts.
2749 Also implies COMMON.
2750 -1 indicates a bitwise operation; this makes a difference
2751 in the exact conditions for when it is safe to do the operation
2752 in a narrower mode. */
2755 /* Nonzero if this is a comparison operation;
2756 if both args are promoted shorts, compare the original shorts.
2757 Also implies COMMON. */
2758 int short_compare = 0;
2760 /* Nonzero if this is a right-shift operation, which can be computed on the
2761 original short and then promoted if the operand is a promoted short. */
2762 int short_shift = 0;
2764 /* Nonzero means set RESULT_TYPE to the common type of the args. */
2767 /* True if both operands have arithmetic type. */
2768 bool arithmetic_types_p;
2770 /* Apply default conversions. */
2774 if (code == TRUTH_AND_EXPR || code == TRUTH_ANDIF_EXPR
2775 || code == TRUTH_OR_EXPR || code == TRUTH_ORIF_EXPR
2776 || code == TRUTH_XOR_EXPR)
2778 if (!really_overloaded_fn (op0))
2779 op0 = decay_conversion (op0);
2780 if (!really_overloaded_fn (op1))
2781 op1 = decay_conversion (op1);
2785 if (!really_overloaded_fn (op0))
2786 op0 = default_conversion (op0);
2787 if (!really_overloaded_fn (op1))
2788 op1 = default_conversion (op1);
2791 /* Strip NON_LVALUE_EXPRs, etc., since we aren't using as an lvalue. */
2792 STRIP_TYPE_NOPS (op0);
2793 STRIP_TYPE_NOPS (op1);
2795 /* DTRT if one side is an overloaded function, but complain about it. */
2796 if (type_unknown_p (op0))
2798 tree t = instantiate_type (TREE_TYPE (op1), op0, tf_none);
2799 if (t != error_mark_node)
2801 pedwarn ("assuming cast to type %qT from overloaded function",
2806 if (type_unknown_p (op1))
2808 tree t = instantiate_type (TREE_TYPE (op0), op1, tf_none);
2809 if (t != error_mark_node)
2811 pedwarn ("assuming cast to type %qT from overloaded function",
2817 type0 = TREE_TYPE (op0);
2818 type1 = TREE_TYPE (op1);
2820 /* The expression codes of the data types of the arguments tell us
2821 whether the arguments are integers, floating, pointers, etc. */
2822 code0 = TREE_CODE (type0);
2823 code1 = TREE_CODE (type1);
2825 /* If an error was already reported for one of the arguments,
2826 avoid reporting another error. */
2828 if (code0 == ERROR_MARK || code1 == ERROR_MARK)
2829 return error_mark_node;
2834 /* Handle the pointer + int case. */
2835 if (code0 == POINTER_TYPE && code1 == INTEGER_TYPE)
2836 return cp_pointer_int_sum (PLUS_EXPR, op0, op1);
2837 else if (code1 == POINTER_TYPE && code0 == INTEGER_TYPE)
2838 return cp_pointer_int_sum (PLUS_EXPR, op1, op0);
2844 /* Subtraction of two similar pointers.
2845 We must subtract them as integers, then divide by object size. */
2846 if (code0 == POINTER_TYPE && code1 == POINTER_TYPE
2847 && same_type_ignoring_top_level_qualifiers_p (TREE_TYPE (type0),
2849 return pointer_diff (op0, op1, common_type (type0, type1));
2850 /* Handle pointer minus int. Just like pointer plus int. */
2851 else if (code0 == POINTER_TYPE && code1 == INTEGER_TYPE)
2852 return cp_pointer_int_sum (MINUS_EXPR, op0, op1);
2861 case TRUNC_DIV_EXPR:
2863 case FLOOR_DIV_EXPR:
2864 case ROUND_DIV_EXPR:
2865 case EXACT_DIV_EXPR:
2866 if ((code0 == INTEGER_TYPE || code0 == REAL_TYPE
2867 || code0 == COMPLEX_TYPE || code0 == VECTOR_TYPE)
2868 && (code1 == INTEGER_TYPE || code1 == REAL_TYPE
2869 || code1 == COMPLEX_TYPE || code1 == VECTOR_TYPE))
2871 if (TREE_CODE (op1) == INTEGER_CST && integer_zerop (op1))
2872 warning ("division by zero in %<%E / 0%>", op0);
2873 else if (TREE_CODE (op1) == REAL_CST && real_zerop (op1))
2874 warning ("division by zero in %<%E / 0.%>", op0);
2876 if (code0 == COMPLEX_TYPE || code0 == VECTOR_TYPE)
2877 code0 = TREE_CODE (TREE_TYPE (TREE_TYPE (op0)));
2878 if (code1 == COMPLEX_TYPE || code1 == VECTOR_TYPE)
2879 code1 = TREE_CODE (TREE_TYPE (TREE_TYPE (op1)));
2881 if (!(code0 == INTEGER_TYPE && code1 == INTEGER_TYPE))
2882 resultcode = RDIV_EXPR;
2884 /* When dividing two signed integers, we have to promote to int.
2885 unless we divide by a constant != -1. Note that default
2886 conversion will have been performed on the operands at this
2887 point, so we have to dig out the original type to find out if
2889 shorten = ((TREE_CODE (op0) == NOP_EXPR
2890 && TYPE_UNSIGNED (TREE_TYPE (TREE_OPERAND (op0, 0))))
2891 || (TREE_CODE (op1) == INTEGER_CST
2892 && ! integer_all_onesp (op1)));
2901 if (code0 == INTEGER_TYPE && code1 == INTEGER_TYPE)
2905 case TRUNC_MOD_EXPR:
2906 case FLOOR_MOD_EXPR:
2907 if (code1 == INTEGER_TYPE && integer_zerop (op1))
2908 warning ("division by zero in %<%E %% 0%>", op0);
2909 else if (code1 == REAL_TYPE && real_zerop (op1))
2910 warning ("division by zero in %<%E %% 0.%>", op0);
2912 if (code0 == INTEGER_TYPE && code1 == INTEGER_TYPE)
2914 /* Although it would be tempting to shorten always here, that loses
2915 on some targets, since the modulo instruction is undefined if the
2916 quotient can't be represented in the computation mode. We shorten
2917 only if unsigned or if dividing by something we know != -1. */
2918 shorten = ((TREE_CODE (op0) == NOP_EXPR
2919 && TYPE_UNSIGNED (TREE_TYPE (TREE_OPERAND (op0, 0))))
2920 || (TREE_CODE (op1) == INTEGER_CST
2921 && ! integer_all_onesp (op1)));
2926 case TRUTH_ANDIF_EXPR:
2927 case TRUTH_ORIF_EXPR:
2928 case TRUTH_AND_EXPR:
2930 result_type = boolean_type_node;
2933 /* Shift operations: result has same type as first operand;
2934 always convert second operand to int.
2935 Also set SHORT_SHIFT if shifting rightward. */
2938 if (code0 == INTEGER_TYPE && code1 == INTEGER_TYPE)
2940 result_type = type0;
2941 if (TREE_CODE (op1) == INTEGER_CST)
2943 if (tree_int_cst_lt (op1, integer_zero_node))
2944 warning ("right shift count is negative");
2947 if (! integer_zerop (op1))
2949 if (compare_tree_int (op1, TYPE_PRECISION (type0)) >= 0)
2950 warning ("right shift count >= width of type");
2953 /* Convert the shift-count to an integer, regardless of
2954 size of value being shifted. */
2955 if (TYPE_MAIN_VARIANT (TREE_TYPE (op1)) != integer_type_node)
2956 op1 = cp_convert (integer_type_node, op1);
2957 /* Avoid converting op1 to result_type later. */
2963 if (code0 == INTEGER_TYPE && code1 == INTEGER_TYPE)
2965 result_type = type0;
2966 if (TREE_CODE (op1) == INTEGER_CST)
2968 if (tree_int_cst_lt (op1, integer_zero_node))
2969 warning ("left shift count is negative");
2970 else if (compare_tree_int (op1, TYPE_PRECISION (type0)) >= 0)
2971 warning ("left shift count >= width of type");
2973 /* Convert the shift-count to an integer, regardless of
2974 size of value being shifted. */
2975 if (TYPE_MAIN_VARIANT (TREE_TYPE (op1)) != integer_type_node)
2976 op1 = cp_convert (integer_type_node, op1);
2977 /* Avoid converting op1 to result_type later. */
2984 if (code0 == INTEGER_TYPE && code1 == INTEGER_TYPE)
2986 result_type = type0;
2987 if (TREE_CODE (op1) == INTEGER_CST)
2989 if (tree_int_cst_lt (op1, integer_zero_node))
2990 warning ("%s rotate count is negative",
2991 (code == LROTATE_EXPR) ? "left" : "right");
2992 else if (compare_tree_int (op1, TYPE_PRECISION (type0)) >= 0)
2993 warning ("%s rotate count >= width of type",
2994 (code == LROTATE_EXPR) ? "left" : "right");
2996 /* Convert the shift-count to an integer, regardless of
2997 size of value being shifted. */
2998 if (TYPE_MAIN_VARIANT (TREE_TYPE (op1)) != integer_type_node)
2999 op1 = cp_convert (integer_type_node, op1);
3005 if (warn_float_equal && (code0 == REAL_TYPE || code1 == REAL_TYPE))
3006 warning ("comparing floating point with == or != is unsafe");
3008 build_type = boolean_type_node;
3009 if ((code0 == INTEGER_TYPE || code0 == REAL_TYPE
3010 || code0 == COMPLEX_TYPE)
3011 && (code1 == INTEGER_TYPE || code1 == REAL_TYPE
3012 || code1 == COMPLEX_TYPE))
3014 else if ((code0 == POINTER_TYPE && code1 == POINTER_TYPE)
3015 || (TYPE_PTRMEM_P (type0) && TYPE_PTRMEM_P (type1)))
3016 result_type = composite_pointer_type (type0, type1, op0, op1,
3018 else if ((code0 == POINTER_TYPE || TYPE_PTRMEM_P (type0))
3019 && null_ptr_cst_p (op1))
3020 result_type = type0;
3021 else if ((code1 == POINTER_TYPE || TYPE_PTRMEM_P (type1))
3022 && null_ptr_cst_p (op0))
3023 result_type = type1;
3024 else if (code0 == POINTER_TYPE && code1 == INTEGER_TYPE)
3026 result_type = type0;
3027 error ("ISO C++ forbids comparison between pointer and integer");
3029 else if (code0 == INTEGER_TYPE && code1 == POINTER_TYPE)
3031 result_type = type1;
3032 error ("ISO C++ forbids comparison between pointer and integer");
3034 else if (TYPE_PTRMEMFUNC_P (type0) && null_ptr_cst_p (op1))
3036 op0 = build_ptrmemfunc_access_expr (op0, pfn_identifier);
3037 op1 = cp_convert (TREE_TYPE (op0), integer_zero_node);
3038 result_type = TREE_TYPE (op0);
3040 else if (TYPE_PTRMEMFUNC_P (type1) && null_ptr_cst_p (op0))
3041 return cp_build_binary_op (code, op1, op0);
3042 else if (TYPE_PTRMEMFUNC_P (type0) && TYPE_PTRMEMFUNC_P (type1)
3043 && same_type_p (type0, type1))
3045 /* E will be the final comparison. */
3047 /* E1 and E2 are for scratch. */
3055 if (TREE_SIDE_EFFECTS (op0))
3056 op0 = save_expr (op0);
3057 if (TREE_SIDE_EFFECTS (op1))
3058 op1 = save_expr (op1);
3063 && (!op0.pfn || op0.delta == op1.delta))
3065 The reason for the `!op0.pfn' bit is that a NULL
3066 pointer-to-member is any member with a zero PFN; the
3067 DELTA field is unspecified. */
3068 pfn0 = pfn_from_ptrmemfunc (op0);
3069 pfn1 = pfn_from_ptrmemfunc (op1);
3070 delta0 = build_ptrmemfunc_access_expr (op0,
3072 delta1 = build_ptrmemfunc_access_expr (op1,
3074 e1 = cp_build_binary_op (EQ_EXPR, delta0, delta1);
3075 e2 = cp_build_binary_op (EQ_EXPR,
3077 cp_convert (TREE_TYPE (pfn0),
3078 integer_zero_node));
3079 e1 = cp_build_binary_op (TRUTH_ORIF_EXPR, e1, e2);
3080 e2 = build2 (EQ_EXPR, boolean_type_node, pfn0, pfn1);
3081 e = cp_build_binary_op (TRUTH_ANDIF_EXPR, e2, e1);
3082 if (code == EQ_EXPR)
3084 return cp_build_binary_op (EQ_EXPR, e, integer_zero_node);
3088 gcc_assert (!TYPE_PTRMEMFUNC_P (type0)
3089 || !same_type_p (TYPE_PTRMEMFUNC_FN_TYPE (type0),
3091 gcc_assert (!TYPE_PTRMEMFUNC_P (type1)
3092 || !same_type_p (TYPE_PTRMEMFUNC_FN_TYPE (type1),
3100 if ((code0 == INTEGER_TYPE || code0 == REAL_TYPE)
3101 && (code1 == INTEGER_TYPE || code1 == REAL_TYPE))
3103 else if (code0 == POINTER_TYPE && code1 == POINTER_TYPE)
3104 result_type = composite_pointer_type (type0, type1, op0, op1,
3112 build_type = boolean_type_node;
3113 if ((code0 == INTEGER_TYPE || code0 == REAL_TYPE)
3114 && (code1 == INTEGER_TYPE || code1 == REAL_TYPE))
3116 else if (code0 == POINTER_TYPE && code1 == POINTER_TYPE)
3117 result_type = composite_pointer_type (type0, type1, op0, op1,
3119 else if (code0 == POINTER_TYPE && TREE_CODE (op1) == INTEGER_CST
3120 && integer_zerop (op1))
3121 result_type = type0;
3122 else if (code1 == POINTER_TYPE && TREE_CODE (op0) == INTEGER_CST
3123 && integer_zerop (op0))
3124 result_type = type1;
3125 else if (code0 == POINTER_TYPE && code1 == INTEGER_TYPE)
3127 result_type = type0;
3128 pedwarn ("ISO C++ forbids comparison between pointer and integer");
3130 else if (code0 == INTEGER_TYPE && code1 == POINTER_TYPE)
3132 result_type = type1;
3133 pedwarn ("ISO C++ forbids comparison between pointer and integer");
3137 case UNORDERED_EXPR:
3144 build_type = integer_type_node;
3145 if (code0 != REAL_TYPE || code1 != REAL_TYPE)
3147 error ("unordered comparison on non-floating point argument");
3148 return error_mark_node;
3157 arithmetic_types_p =
3158 ((code0 == INTEGER_TYPE || code0 == REAL_TYPE || code0 == COMPLEX_TYPE)
3159 && (code1 == INTEGER_TYPE || code1 == REAL_TYPE
3160 || code1 == COMPLEX_TYPE));
3161 /* Determine the RESULT_TYPE, if it is not already known. */
3163 && arithmetic_types_p
3164 && (shorten || common || short_compare))
3165 result_type = common_type (type0, type1);
3169 error ("invalid operands of types %qT and %qT to binary %qO",
3170 TREE_TYPE (orig_op0), TREE_TYPE (orig_op1), code);
3171 return error_mark_node;
3174 /* If we're in a template, the only thing we need to know is the
3176 if (processing_template_decl)
3177 return build2 (resultcode,
3178 build_type ? build_type : result_type,
3181 if (arithmetic_types_p)
3183 int none_complex = (code0 != COMPLEX_TYPE && code1 != COMPLEX_TYPE);
3185 /* For certain operations (which identify themselves by shorten != 0)
3186 if both args were extended from the same smaller type,
3187 do the arithmetic in that type and then extend.
3189 shorten !=0 and !=1 indicates a bitwise operation.
3190 For them, this optimization is safe only if
3191 both args are zero-extended or both are sign-extended.
3192 Otherwise, we might change the result.
3193 Eg, (short)-1 | (unsigned short)-1 is (int)-1
3194 but calculated in (unsigned short) it would be (unsigned short)-1. */
3196 if (shorten && none_complex)
3198 int unsigned0, unsigned1;
3199 tree arg0 = get_narrower (op0, &unsigned0);
3200 tree arg1 = get_narrower (op1, &unsigned1);
3201 /* UNS is 1 if the operation to be done is an unsigned one. */
3202 int uns = TYPE_UNSIGNED (result_type);
3205 final_type = result_type;
3207 /* Handle the case that OP0 does not *contain* a conversion
3208 but it *requires* conversion to FINAL_TYPE. */
3210 if (op0 == arg0 && TREE_TYPE (op0) != final_type)
3211 unsigned0 = TYPE_UNSIGNED (TREE_TYPE (op0));
3212 if (op1 == arg1 && TREE_TYPE (op1) != final_type)
3213 unsigned1 = TYPE_UNSIGNED (TREE_TYPE (op1));
3215 /* Now UNSIGNED0 is 1 if ARG0 zero-extends to FINAL_TYPE. */
3217 /* For bitwise operations, signedness of nominal type
3218 does not matter. Consider only how operands were extended. */
3222 /* Note that in all three cases below we refrain from optimizing
3223 an unsigned operation on sign-extended args.
3224 That would not be valid. */
3226 /* Both args variable: if both extended in same way
3227 from same width, do it in that width.
3228 Do it unsigned if args were zero-extended. */
3229 if ((TYPE_PRECISION (TREE_TYPE (arg0))
3230 < TYPE_PRECISION (result_type))
3231 && (TYPE_PRECISION (TREE_TYPE (arg1))
3232 == TYPE_PRECISION (TREE_TYPE (arg0)))
3233 && unsigned0 == unsigned1
3234 && (unsigned0 || !uns))
3235 result_type = c_common_signed_or_unsigned_type
3236 (unsigned0, common_type (TREE_TYPE (arg0), TREE_TYPE (arg1)));
3237 else if (TREE_CODE (arg0) == INTEGER_CST
3238 && (unsigned1 || !uns)
3239 && (TYPE_PRECISION (TREE_TYPE (arg1))
3240 < TYPE_PRECISION (result_type))
3241 && (type = c_common_signed_or_unsigned_type
3242 (unsigned1, TREE_TYPE (arg1)),
3243 int_fits_type_p (arg0, type)))
3245 else if (TREE_CODE (arg1) == INTEGER_CST
3246 && (unsigned0 || !uns)
3247 && (TYPE_PRECISION (TREE_TYPE (arg0))
3248 < TYPE_PRECISION (result_type))
3249 && (type = c_common_signed_or_unsigned_type
3250 (unsigned0, TREE_TYPE (arg0)),
3251 int_fits_type_p (arg1, type)))
3255 /* Shifts can be shortened if shifting right. */
3260 tree arg0 = get_narrower (op0, &unsigned_arg);
3262 final_type = result_type;
3264 if (arg0 == op0 && final_type == TREE_TYPE (op0))
3265 unsigned_arg = TYPE_UNSIGNED (TREE_TYPE (op0));
3267 if (TYPE_PRECISION (TREE_TYPE (arg0)) < TYPE_PRECISION (result_type)
3268 /* We can shorten only if the shift count is less than the
3269 number of bits in the smaller type size. */
3270 && compare_tree_int (op1, TYPE_PRECISION (TREE_TYPE (arg0))) < 0
3271 /* If arg is sign-extended and then unsigned-shifted,
3272 we can simulate this with a signed shift in arg's type
3273 only if the extended result is at least twice as wide
3274 as the arg. Otherwise, the shift could use up all the
3275 ones made by sign-extension and bring in zeros.
3276 We can't optimize that case at all, but in most machines
3277 it never happens because available widths are 2**N. */
3278 && (!TYPE_UNSIGNED (final_type)
3280 || (((unsigned) 2 * TYPE_PRECISION (TREE_TYPE (arg0)))
3281 <= TYPE_PRECISION (result_type))))
3283 /* Do an unsigned shift if the operand was zero-extended. */
3285 = c_common_signed_or_unsigned_type (unsigned_arg,
3287 /* Convert value-to-be-shifted to that type. */
3288 if (TREE_TYPE (op0) != result_type)
3289 op0 = cp_convert (result_type, op0);
3294 /* Comparison operations are shortened too but differently.
3295 They identify themselves by setting short_compare = 1. */
3299 /* Don't write &op0, etc., because that would prevent op0
3300 from being kept in a register.
3301 Instead, make copies of the our local variables and
3302 pass the copies by reference, then copy them back afterward. */
3303 tree xop0 = op0, xop1 = op1, xresult_type = result_type;
3304 enum tree_code xresultcode = resultcode;
3306 = shorten_compare (&xop0, &xop1, &xresult_type, &xresultcode);
3308 return cp_convert (boolean_type_node, val);
3309 op0 = xop0, op1 = xop1;
3311 resultcode = xresultcode;
3314 if ((short_compare || code == MIN_EXPR || code == MAX_EXPR)
3315 && warn_sign_compare
3316 /* Do not warn until the template is instantiated; we cannot
3317 bound the ranges of the arguments until that point. */
3318 && !processing_template_decl)
3320 int op0_signed = !TYPE_UNSIGNED (TREE_TYPE (orig_op0));
3321 int op1_signed = !TYPE_UNSIGNED (TREE_TYPE (orig_op1));
3323 int unsignedp0, unsignedp1;
3324 tree primop0 = get_narrower (op0, &unsignedp0);
3325 tree primop1 = get_narrower (op1, &unsignedp1);
3327 /* Check for comparison of different enum types. */
3328 if (TREE_CODE (TREE_TYPE (orig_op0)) == ENUMERAL_TYPE
3329 && TREE_CODE (TREE_TYPE (orig_op1)) == ENUMERAL_TYPE
3330 && TYPE_MAIN_VARIANT (TREE_TYPE (orig_op0))
3331 != TYPE_MAIN_VARIANT (TREE_TYPE (orig_op1)))
3333 warning ("comparison between types %q#T and %q#T",
3334 TREE_TYPE (orig_op0), TREE_TYPE (orig_op1));
3337 /* Give warnings for comparisons between signed and unsigned
3338 quantities that may fail. */
3339 /* Do the checking based on the original operand trees, so that
3340 casts will be considered, but default promotions won't be. */
3342 /* Do not warn if the comparison is being done in a signed type,
3343 since the signed type will only be chosen if it can represent
3344 all the values of the unsigned type. */
3345 if (!TYPE_UNSIGNED (result_type))
3347 /* Do not warn if both operands are unsigned. */
3348 else if (op0_signed == op1_signed)
3350 /* Do not warn if the signed quantity is an unsuffixed
3351 integer literal (or some static constant expression
3352 involving such literals or a conditional expression
3353 involving such literals) and it is non-negative. */
3354 else if ((op0_signed && tree_expr_nonnegative_p (orig_op0))
3355 || (op1_signed && tree_expr_nonnegative_p (orig_op1)))
3357 /* Do not warn if the comparison is an equality operation,
3358 the unsigned quantity is an integral constant and it does
3359 not use the most significant bit of result_type. */
3360 else if ((resultcode == EQ_EXPR || resultcode == NE_EXPR)
3361 && ((op0_signed && TREE_CODE (orig_op1) == INTEGER_CST
3362 && int_fits_type_p (orig_op1, c_common_signed_type
3364 || (op1_signed && TREE_CODE (orig_op0) == INTEGER_CST
3365 && int_fits_type_p (orig_op0, c_common_signed_type
3369 warning ("comparison between signed and unsigned integer expressions");
3371 /* Warn if two unsigned values are being compared in a size
3372 larger than their original size, and one (and only one) is the
3373 result of a `~' operator. This comparison will always fail.
3375 Also warn if one operand is a constant, and the constant does not
3376 have all bits set that are set in the ~ operand when it is
3379 if ((TREE_CODE (primop0) == BIT_NOT_EXPR)
3380 ^ (TREE_CODE (primop1) == BIT_NOT_EXPR))
3382 if (TREE_CODE (primop0) == BIT_NOT_EXPR)
3383 primop0 = get_narrower (TREE_OPERAND (op0, 0), &unsignedp0);
3384 if (TREE_CODE (primop1) == BIT_NOT_EXPR)
3385 primop1 = get_narrower (TREE_OPERAND (op1, 0), &unsignedp1);
3387 if (host_integerp (primop0, 0) || host_integerp (primop1, 0))
3390 HOST_WIDE_INT constant, mask;
3394 if (host_integerp (primop0, 0))
3397 unsignedp = unsignedp1;
3398 constant = tree_low_cst (primop0, 0);
3403 unsignedp = unsignedp0;
3404 constant = tree_low_cst (primop1, 0);
3407 bits = TYPE_PRECISION (TREE_TYPE (primop));
3408 if (bits < TYPE_PRECISION (result_type)
3409 && bits < HOST_BITS_PER_LONG && unsignedp)
3411 mask = (~ (HOST_WIDE_INT) 0) << bits;
3412 if ((mask & constant) != mask)
3413 warning ("comparison of promoted ~unsigned with constant");
3416 else if (unsignedp0 && unsignedp1
3417 && (TYPE_PRECISION (TREE_TYPE (primop0))
3418 < TYPE_PRECISION (result_type))
3419 && (TYPE_PRECISION (TREE_TYPE (primop1))
3420 < TYPE_PRECISION (result_type)))
3421 warning ("comparison of promoted ~unsigned with unsigned");
3426 /* If CONVERTED is zero, both args will be converted to type RESULT_TYPE.
3427 Then the expression will be built.
3428 It will be given type FINAL_TYPE if that is nonzero;
3429 otherwise, it will be given type RESULT_TYPE. */
3431 /* Issue warnings about peculiar, but valid, uses of NULL. */
3432 if (/* It's reasonable to use pointer values as operands of &&
3433 and ||, so NULL is no exception. */
3434 !(code == TRUTH_ANDIF_EXPR || code == TRUTH_ORIF_EXPR)
3435 && (/* If OP0 is NULL and OP1 is not a pointer, or vice versa. */
3436 (orig_op0 == null_node
3437 && TREE_CODE (TREE_TYPE (op1)) != POINTER_TYPE)
3438 /* Or vice versa. */
3439 || (orig_op1 == null_node
3440 && TREE_CODE (TREE_TYPE (op0)) != POINTER_TYPE)
3441 /* Or, both are NULL and the operation was not a comparison. */
3442 || (orig_op0 == null_node && orig_op1 == null_node
3443 && code != EQ_EXPR && code != NE_EXPR)))
3444 /* Some sort of arithmetic operation involving NULL was
3445 performed. Note that pointer-difference and pointer-addition
3446 have already been handled above, and so we don't end up here in
3448 warning ("NULL used in arithmetic");
3452 if (TREE_TYPE (op0) != result_type)
3453 op0 = cp_convert (result_type, op0);
3454 if (TREE_TYPE (op1) != result_type)
3455 op1 = cp_convert (result_type, op1);
3457 if (op0 == error_mark_node || op1 == error_mark_node)
3458 return error_mark_node;
3461 if (build_type == NULL_TREE)
3462 build_type = result_type;
3464 result = build2 (resultcode, build_type, op0, op1);
3465 result = fold_if_not_in_template (result);
3466 if (final_type != 0)
3467 result = cp_convert (final_type, result);
3471 /* Return a tree for the sum or difference (RESULTCODE says which)
3472 of pointer PTROP and integer INTOP. */
3475 cp_pointer_int_sum (enum tree_code resultcode, tree ptrop, tree intop)
3477 tree res_type = TREE_TYPE (ptrop);
3479 /* pointer_int_sum() uses size_in_bytes() on the TREE_TYPE(res_type)
3480 in certain circumstance (when it's valid to do so). So we need
3481 to make sure it's complete. We don't need to check here, if we
3482 can actually complete it at all, as those checks will be done in
3483 pointer_int_sum() anyway. */
3484 complete_type (TREE_TYPE (res_type));
3486 return pointer_int_sum (resultcode, ptrop,
3487 fold_if_not_in_template (intop));
3490 /* Return a tree for the difference of pointers OP0 and OP1.
3491 The resulting tree has type int. */
3494 pointer_diff (tree op0, tree op1, tree ptrtype)
3497 tree restype = ptrdiff_type_node;
3498 tree target_type = TREE_TYPE (ptrtype);
3500 if (!complete_type_or_else (target_type, NULL_TREE))
3501 return error_mark_node;
3503 if (pedantic || warn_pointer_arith)
3505 if (TREE_CODE (target_type) == VOID_TYPE)
3506 pedwarn ("ISO C++ forbids using pointer of type %<void *%> in subtraction");
3507 if (TREE_CODE (target_type) == FUNCTION_TYPE)
3508 pedwarn ("ISO C++ forbids using pointer to a function in subtraction");
3509 if (TREE_CODE (target_type) == METHOD_TYPE)
3510 pedwarn ("ISO C++ forbids using pointer to a method in subtraction");
3513 /* First do the subtraction as integers;
3514 then drop through to build the divide operator. */
3516 op0 = cp_build_binary_op (MINUS_EXPR,
3517 cp_convert (restype, op0),
3518 cp_convert (restype, op1));
3520 /* This generates an error if op1 is a pointer to an incomplete type. */
3521 if (!COMPLETE_TYPE_P (TREE_TYPE (TREE_TYPE (op1))))
3522 error ("invalid use of a pointer to an incomplete type in pointer arithmetic");
3524 op1 = (TYPE_PTROB_P (ptrtype)
3525 ? size_in_bytes (target_type)
3526 : integer_one_node);
3528 /* Do the division. */
3530 result = build2 (EXACT_DIV_EXPR, restype, op0, cp_convert (restype, op1));
3531 return fold_if_not_in_template (result);
3534 /* Construct and perhaps optimize a tree representation
3535 for a unary operation. CODE, a tree_code, specifies the operation
3536 and XARG is the operand. */
3539 build_x_unary_op (enum tree_code code, tree xarg)
3541 tree orig_expr = xarg;
3545 if (processing_template_decl)
3547 if (type_dependent_expression_p (xarg))
3548 return build_min_nt (code, xarg, NULL_TREE);
3550 /* For non-dependent pointer-to-member, the SCOPE_REF will be
3551 processed during template substitution. Just compute the
3552 right type here and build an ADDR_EXPR around it for
3554 if (code == ADDR_EXPR && TREE_CODE (xarg) == SCOPE_REF)
3557 if (TREE_TYPE (xarg) == unknown_type_node)
3558 type = unknown_type_node;
3559 else if (TREE_CODE (TREE_TYPE (xarg)) == FUNCTION_TYPE)
3560 type = build_pointer_type (TREE_TYPE (xarg));
3562 type = build_ptrmem_type (TREE_OPERAND (xarg, 0),
3564 return build_min (code, type, xarg, NULL_TREE);
3567 xarg = build_non_dependent_expr (xarg);
3572 /* [expr.unary.op] says:
3574 The address of an object of incomplete type can be taken.
3576 (And is just the ordinary address operator, not an overloaded
3577 "operator &".) However, if the type is a template
3578 specialization, we must complete the type at this point so that
3579 an overloaded "operator &" will be available if required. */
3580 if (code == ADDR_EXPR
3581 && TREE_CODE (xarg) != TEMPLATE_ID_EXPR
3582 && ((CLASS_TYPE_P (TREE_TYPE (xarg))
3583 && !COMPLETE_TYPE_P (complete_type (TREE_TYPE (xarg))))
3584 || (TREE_CODE (xarg) == OFFSET_REF)))
3585 /* Don't look for a function. */;
3587 exp = build_new_op (code, LOOKUP_NORMAL, xarg, NULL_TREE, NULL_TREE,
3588 /*overloaded_p=*/NULL);
3589 if (!exp && code == ADDR_EXPR)
3591 /* A pointer to member-function can be formed only by saying
3593 if (!flag_ms_extensions && TREE_CODE (TREE_TYPE (xarg)) == METHOD_TYPE
3594 && (TREE_CODE (xarg) != OFFSET_REF || !PTRMEM_OK_P (xarg)))
3596 if (TREE_CODE (xarg) != OFFSET_REF)
3598 error ("invalid use of %qE to form a pointer-to-member-function."
3599 " Use a qualified-id.",
3601 return error_mark_node;
3605 error ("parenthesis around %qE cannot be used to form a"
3606 " pointer-to-member-function",
3608 PTRMEM_OK_P (xarg) = 1;
3612 if (TREE_CODE (xarg) == OFFSET_REF)
3614 ptrmem = PTRMEM_OK_P (xarg);
3616 if (!ptrmem && !flag_ms_extensions
3617 && TREE_CODE (TREE_TYPE (TREE_OPERAND (xarg, 1))) == METHOD_TYPE)
3619 /* A single non-static member, make sure we don't allow a
3620 pointer-to-member. */
3621 xarg = build2 (OFFSET_REF, TREE_TYPE (xarg),
3622 TREE_OPERAND (xarg, 0),
3623 ovl_cons (TREE_OPERAND (xarg, 1), NULL_TREE));
3624 PTRMEM_OK_P (xarg) = ptrmem;
3627 else if (TREE_CODE (xarg) == TARGET_EXPR)
3628 warning ("taking address of temporary");
3629 exp = build_unary_op (ADDR_EXPR, xarg, 0);
3630 if (TREE_CODE (exp) == ADDR_EXPR)
3631 PTRMEM_OK_P (exp) = ptrmem;
3634 if (processing_template_decl && exp != error_mark_node)
3635 return build_min_non_dep (code, exp, orig_expr,
3636 /*For {PRE,POST}{INC,DEC}REMENT_EXPR*/NULL_TREE);
3640 /* Like c_common_truthvalue_conversion, but handle pointer-to-member
3641 constants, where a null value is represented by an INTEGER_CST of
3645 cp_truthvalue_conversion (tree expr)
3647 tree type = TREE_TYPE (expr);
3648 if (TYPE_PTRMEM_P (type))
3649 return build_binary_op (NE_EXPR, expr, integer_zero_node, 1);
3651 return c_common_truthvalue_conversion (expr);
3654 /* Just like cp_truthvalue_conversion, but we want a CLEANUP_POINT_EXPR. */
3657 condition_conversion (tree expr)
3660 if (processing_template_decl)
3662 t = perform_implicit_conversion (boolean_type_node, expr);
3663 t = fold_build_cleanup_point_expr (boolean_type_node, t);
3667 /* Return an ADDR_EXPR giving the address of T. This function
3668 attempts no optimizations or simplifications; it is a low-level
3672 build_address (tree t)
3676 if (error_operand_p (t) || !cxx_mark_addressable (t))
3677 return error_mark_node;
3679 addr = build1 (ADDR_EXPR, build_pointer_type (TREE_TYPE (t)), t);
3684 /* Return a NOP_EXPR converting EXPR to TYPE. */
3687 build_nop (tree type, tree expr)
3689 if (type == error_mark_node || error_operand_p (expr))
3691 return build1 (NOP_EXPR, type, expr);
3694 /* C++: Must handle pointers to members.
3696 Perhaps type instantiation should be extended to handle conversion
3697 from aggregates to types we don't yet know we want? (Or are those
3698 cases typically errors which should be reported?)
3700 NOCONVERT nonzero suppresses the default promotions
3701 (such as from short to int). */
3704 build_unary_op (enum tree_code code, tree xarg, int noconvert)
3706 /* No default_conversion here. It causes trouble for ADDR_EXPR. */
3709 const char *errstring = NULL;
3712 if (arg == error_mark_node)
3713 return error_mark_node;
3717 /* CONVERT_EXPR stands for unary plus in this context. */
3721 int flags = WANT_ARITH | WANT_ENUM;
3722 /* Unary plus (but not unary minus) is allowed on pointers. */
3723 if (code == CONVERT_EXPR)
3724 flags |= WANT_POINTER;
3725 arg = build_expr_type_conversion (flags, arg, true);
3727 errstring = (code == NEGATE_EXPR
3728 ? "wrong type argument to unary minus"
3729 : "wrong type argument to unary plus");
3732 if (!noconvert && CP_INTEGRAL_TYPE_P (TREE_TYPE (arg)))
3733 arg = perform_integral_promotions (arg);
3735 /* Make sure the result is not a lvalue: a unary plus or minus
3736 expression is always a rvalue. */
3737 if (real_lvalue_p (arg))
3738 arg = build1 (NON_LVALUE_EXPR, TREE_TYPE (arg), arg);
3744 if (TREE_CODE (TREE_TYPE (arg)) == COMPLEX_TYPE)
3748 arg = default_conversion (arg);
3750 else if (!(arg = build_expr_type_conversion (WANT_INT | WANT_ENUM,
3752 errstring = "wrong type argument to bit-complement";
3753 else if (!noconvert)
3754 arg = perform_integral_promotions (arg);
3758 if (!(arg = build_expr_type_conversion (WANT_ARITH | WANT_ENUM, arg, true)))
3759 errstring = "wrong type argument to abs";
3760 else if (!noconvert)
3761 arg = default_conversion (arg);
3765 /* Conjugating a real value is a no-op, but allow it anyway. */
3766 if (!(arg = build_expr_type_conversion (WANT_ARITH | WANT_ENUM, arg, true)))
3767 errstring = "wrong type argument to conjugation";
3768 else if (!noconvert)
3769 arg = default_conversion (arg);
3772 case TRUTH_NOT_EXPR:
3773 arg = perform_implicit_conversion (boolean_type_node, arg);
3774 val = invert_truthvalue (arg);
3775 if (arg != error_mark_node)
3777 errstring = "in argument to unary !";
3784 if (TREE_CODE (arg) == COMPLEX_CST)
3785 return TREE_REALPART (arg);
3786 else if (TREE_CODE (TREE_TYPE (arg)) == COMPLEX_TYPE)
3788 arg = build1 (REALPART_EXPR, TREE_TYPE (TREE_TYPE (arg)), arg);
3789 return fold_if_not_in_template (arg);
3795 if (TREE_CODE (arg) == COMPLEX_CST)
3796 return TREE_IMAGPART (arg);
3797 else if (TREE_CODE (TREE_TYPE (arg)) == COMPLEX_TYPE)
3799 arg = build1 (IMAGPART_EXPR, TREE_TYPE (TREE_TYPE (arg)), arg);
3800 return fold_if_not_in_template (arg);
3803 return cp_convert (TREE_TYPE (arg), integer_zero_node);
3805 case PREINCREMENT_EXPR:
3806 case POSTINCREMENT_EXPR:
3807 case PREDECREMENT_EXPR:
3808 case POSTDECREMENT_EXPR:
3809 /* Handle complex lvalues (when permitted)
3810 by reduction to simpler cases. */
3812 val = unary_complex_lvalue (code, arg);
3816 /* Increment or decrement the real part of the value,
3817 and don't change the imaginary part. */
3818 if (TREE_CODE (TREE_TYPE (arg)) == COMPLEX_TYPE)
3822 arg = stabilize_reference (arg);
3823 real = build_unary_op (REALPART_EXPR, arg, 1);
3824 imag = build_unary_op (IMAGPART_EXPR, arg, 1);
3825 return build2 (COMPLEX_EXPR, TREE_TYPE (arg),
3826 build_unary_op (code, real, 1), imag);
3829 /* Report invalid types. */
3831 if (!(arg = build_expr_type_conversion (WANT_ARITH | WANT_POINTER,
3834 if (code == PREINCREMENT_EXPR)
3835 errstring ="no pre-increment operator for type";
3836 else if (code == POSTINCREMENT_EXPR)
3837 errstring ="no post-increment operator for type";
3838 else if (code == PREDECREMENT_EXPR)
3839 errstring ="no pre-decrement operator for type";
3841 errstring ="no post-decrement operator for type";
3845 /* Report something read-only. */
3847 if (CP_TYPE_CONST_P (TREE_TYPE (arg))
3848 || TREE_READONLY (arg))
3849 readonly_error (arg, ((code == PREINCREMENT_EXPR
3850 || code == POSTINCREMENT_EXPR)
3851 ? "increment" : "decrement"),
3856 tree result_type = TREE_TYPE (arg);
3858 arg = get_unwidened (arg, 0);
3859 argtype = TREE_TYPE (arg);
3861 /* ARM $5.2.5 last annotation says this should be forbidden. */
3862 if (TREE_CODE (argtype) == ENUMERAL_TYPE)
3863 pedwarn ("ISO C++ forbids %sing an enum",
3864 (code == PREINCREMENT_EXPR || code == POSTINCREMENT_EXPR)
3865 ? "increment" : "decrement");
3867 /* Compute the increment. */
3869 if (TREE_CODE (argtype) == POINTER_TYPE)
3871 tree type = complete_type (TREE_TYPE (argtype));
3873 if (!COMPLETE_OR_VOID_TYPE_P (type))
3874 error ("cannot %s a pointer to incomplete type %qT",
3875 ((code == PREINCREMENT_EXPR
3876 || code == POSTINCREMENT_EXPR)
3877 ? "increment" : "decrement"), TREE_TYPE (argtype));
3878 else if ((pedantic || warn_pointer_arith)
3879 && !TYPE_PTROB_P (argtype))
3880 pedwarn ("ISO C++ forbids %sing a pointer of type %qT",
3881 ((code == PREINCREMENT_EXPR
3882 || code == POSTINCREMENT_EXPR)
3883 ? "increment" : "decrement"), argtype);
3884 inc = cxx_sizeof_nowarn (TREE_TYPE (argtype));
3887 inc = integer_one_node;
3889 inc = cp_convert (argtype, inc);
3891 /* Handle incrementing a cast-expression. */
3893 switch (TREE_CODE (arg))
3898 case FIX_TRUNC_EXPR:
3899 case FIX_FLOOR_EXPR:
3900 case FIX_ROUND_EXPR:
3903 tree incremented, modify, value, compound;
3904 if (! lvalue_p (arg) && pedantic)
3905 pedwarn ("cast to non-reference type used as lvalue");
3906 arg = stabilize_reference (arg);
3907 if (code == PREINCREMENT_EXPR || code == PREDECREMENT_EXPR)
3910 value = save_expr (arg);
3911 incremented = build2 (((code == PREINCREMENT_EXPR
3912 || code == POSTINCREMENT_EXPR)
3913 ? PLUS_EXPR : MINUS_EXPR),
3914 argtype, value, inc);
3916 modify = build_modify_expr (arg, NOP_EXPR, incremented);
3917 compound = build2 (COMPOUND_EXPR, TREE_TYPE (arg),
3920 /* Eliminate warning about unused result of + or -. */
3921 TREE_NO_WARNING (compound) = 1;
3929 /* Complain about anything else that is not a true lvalue. */
3930 if (!lvalue_or_else (arg, ((code == PREINCREMENT_EXPR
3931 || code == POSTINCREMENT_EXPR)
3932 ? lv_increment : lv_decrement)))
3933 return error_mark_node;
3935 /* Forbid using -- on `bool'. */
3936 if (TREE_TYPE (arg) == boolean_type_node)
3938 if (code == POSTDECREMENT_EXPR || code == PREDECREMENT_EXPR)
3940 error ("invalid use of %<--%> on bool variable %qD", arg);
3941 return error_mark_node;
3943 val = boolean_increment (code, arg);
3946 val = build2 (code, TREE_TYPE (arg), arg, inc);
3948 TREE_SIDE_EFFECTS (val) = 1;
3949 return cp_convert (result_type, val);
3953 /* Note that this operation never does default_conversion
3954 regardless of NOCONVERT. */
3956 argtype = lvalue_type (arg);
3958 if (TREE_CODE (arg) == OFFSET_REF)
3961 if (TREE_CODE (argtype) == REFERENCE_TYPE)
3963 tree type = build_pointer_type (TREE_TYPE (argtype));
3964 arg = build1 (CONVERT_EXPR, type, arg);
3967 else if (pedantic && DECL_MAIN_P (arg))
3969 pedwarn ("ISO C++ forbids taking address of function %<::main%>");
3971 /* Let &* cancel out to simplify resulting code. */
3972 if (TREE_CODE (arg) == INDIRECT_REF)
3974 /* We don't need to have `current_class_ptr' wrapped in a
3975 NON_LVALUE_EXPR node. */
3976 if (arg == current_class_ref)
3977 return current_class_ptr;
3979 arg = TREE_OPERAND (arg, 0);
3980 if (TREE_CODE (TREE_TYPE (arg)) == REFERENCE_TYPE)
3982 tree type = build_pointer_type (TREE_TYPE (TREE_TYPE (arg)));
3983 arg = build1 (CONVERT_EXPR, type, arg);
3985 else if (lvalue_p (arg))
3986 /* Don't let this be an lvalue. */
3987 return non_lvalue (arg);
3991 /* Uninstantiated types are all functions. Taking the
3992 address of a function is a no-op, so just return the
3995 gcc_assert (TREE_CODE (arg) != IDENTIFIER_NODE
3996 || !IDENTIFIER_OPNAME_P (arg));
3998 if (TREE_CODE (arg) == COMPONENT_REF && type_unknown_p (arg)
3999 && !really_overloaded_fn (TREE_OPERAND (arg, 1)))
4001 /* They're trying to take the address of a unique non-static
4002 member function. This is ill-formed (except in MS-land),
4003 but let's try to DTRT.
4004 Note: We only handle unique functions here because we don't
4005 want to complain if there's a static overload; non-unique
4006 cases will be handled by instantiate_type. But we need to
4007 handle this case here to allow casts on the resulting PMF.
4008 We could defer this in non-MS mode, but it's easier to give
4009 a useful error here. */
4011 /* Inside constant member functions, the `this' pointer
4012 contains an extra const qualifier. TYPE_MAIN_VARIANT
4013 is used here to remove this const from the diagnostics
4014 and the created OFFSET_REF. */
4015 tree base = TYPE_MAIN_VARIANT (TREE_TYPE (TREE_OPERAND (arg, 0)));
4016 tree name = DECL_NAME (get_first_fn (TREE_OPERAND (arg, 1)));
4018 if (! flag_ms_extensions)
4020 if (current_class_type
4021 && TREE_OPERAND (arg, 0) == current_class_ref)
4022 /* An expression like &memfn. */
4023 pedwarn ("ISO C++ forbids taking the address of an unqualified"
4024 " or parenthesized non-static member function to form"
4025 " a pointer to member function. Say %<&%T::%D%>",
4028 pedwarn ("ISO C++ forbids taking the address of a bound member"
4029 " function to form a pointer to member function."
4033 arg = build_offset_ref (base, name, /*address_p=*/true);
4037 if (type_unknown_p (arg))
4038 return build1 (ADDR_EXPR, unknown_type_node, arg);
4040 /* Handle complex lvalues (when permitted)
4041 by reduction to simpler cases. */
4042 val = unary_complex_lvalue (code, arg);
4046 switch (TREE_CODE (arg))
4051 case FIX_TRUNC_EXPR:
4052 case FIX_FLOOR_EXPR:
4053 case FIX_ROUND_EXPR:
4055 if (! lvalue_p (arg) && pedantic)
4056 pedwarn ("ISO C++ forbids taking the address of a cast to a non-lvalue expression");
4060 arg = OVL_CURRENT (arg);
4067 /* Allow the address of a constructor if all the elements
4069 if (TREE_CODE (arg) == CONSTRUCTOR && TREE_HAS_CONSTRUCTOR (arg)
4070 && TREE_CONSTANT (arg))
4072 /* Anything not already handled and not a true memory reference
4074 else if (TREE_CODE (argtype) != FUNCTION_TYPE
4075 && TREE_CODE (argtype) != METHOD_TYPE
4076 && !lvalue_or_else (arg, lv_addressof))
4077 return error_mark_node;
4079 if (argtype != error_mark_node)
4080 argtype = build_pointer_type (argtype);
4085 if (TREE_CODE (arg) != COMPONENT_REF
4086 /* Inside a template, we are processing a non-dependent
4087 expression so we can just form an ADDR_EXPR with the
4089 || processing_template_decl)
4090 addr = build_address (arg);
4091 else if (TREE_CODE (TREE_OPERAND (arg, 1)) == BASELINK)
4093 tree fn = BASELINK_FUNCTIONS (TREE_OPERAND (arg, 1));
4095 /* We can only get here with a single static member
4097 gcc_assert (TREE_CODE (fn) == FUNCTION_DECL
4098 && DECL_STATIC_FUNCTION_P (fn));
4100 addr = build_address (fn);
4101 if (TREE_SIDE_EFFECTS (TREE_OPERAND (arg, 0)))
4102 /* Do not lose object's side effects. */
4103 addr = build2 (COMPOUND_EXPR, TREE_TYPE (addr),
4104 TREE_OPERAND (arg, 0), addr);
4106 else if (DECL_C_BIT_FIELD (TREE_OPERAND (arg, 1)))
4108 error ("attempt to take address of bit-field structure member %qD",
4109 TREE_OPERAND (arg, 1));
4110 return error_mark_node;
4114 tree field = TREE_OPERAND (arg, 1);
4115 tree rval = build_unary_op (ADDR_EXPR, TREE_OPERAND (arg, 0), 0);
4116 tree binfo = lookup_base (TREE_TYPE (TREE_TYPE (rval)),
4117 decl_type_context (field),
4120 rval = build_base_path (PLUS_EXPR, rval, binfo, 1);
4122 TREE_OPERAND (arg, 0) = build_indirect_ref (rval, NULL);
4123 addr = build_address (arg);
4126 if (TREE_CODE (argtype) == POINTER_TYPE
4127 && TREE_CODE (TREE_TYPE (argtype)) == METHOD_TYPE)
4129 build_ptrmemfunc_type (argtype);
4130 addr = build_ptrmemfunc (argtype, addr, 0,
4131 /*c_cast_p=*/false);
4144 argtype = TREE_TYPE (arg);
4145 return fold_if_not_in_template (build1 (code, argtype, arg));
4148 error ("%s", errstring);
4149 return error_mark_node;
4152 /* Apply unary lvalue-demanding operator CODE to the expression ARG
4153 for certain kinds of expressions which are not really lvalues
4154 but which we can accept as lvalues.
4156 If ARG is not a kind of expression we can handle, return
4160 unary_complex_lvalue (enum tree_code code, tree arg)
4162 /* Inside a template, making these kinds of adjustments is
4163 pointless; we are only concerned with the type of the
4165 if (processing_template_decl)
4168 /* Handle (a, b) used as an "lvalue". */
4169 if (TREE_CODE (arg) == COMPOUND_EXPR)
4171 tree real_result = build_unary_op (code, TREE_OPERAND (arg, 1), 0);
4172 return build2 (COMPOUND_EXPR, TREE_TYPE (real_result),
4173 TREE_OPERAND (arg, 0), real_result);
4176 /* Handle (a ? b : c) used as an "lvalue". */
4177 if (TREE_CODE (arg) == COND_EXPR
4178 || TREE_CODE (arg) == MIN_EXPR || TREE_CODE (arg) == MAX_EXPR)
4179 return rationalize_conditional_expr (code, arg);
4181 /* Handle (a = b), (++a), and (--a) used as an "lvalue". */
4182 if (TREE_CODE (arg) == MODIFY_EXPR
4183 || TREE_CODE (arg) == PREINCREMENT_EXPR
4184 || TREE_CODE (arg) == PREDECREMENT_EXPR)
4186 tree lvalue = TREE_OPERAND (arg, 0);
4187 if (TREE_SIDE_EFFECTS (lvalue))
4189 lvalue = stabilize_reference (lvalue);
4190 arg = build2 (TREE_CODE (arg), TREE_TYPE (arg),
4191 lvalue, TREE_OPERAND (arg, 1));
4193 return unary_complex_lvalue
4194 (code, build2 (COMPOUND_EXPR, TREE_TYPE (lvalue), arg, lvalue));
4197 if (code != ADDR_EXPR)
4200 /* Handle (a = b) used as an "lvalue" for `&'. */
4201 if (TREE_CODE (arg) == MODIFY_EXPR
4202 || TREE_CODE (arg) == INIT_EXPR)
4204 tree real_result = build_unary_op (code, TREE_OPERAND (arg, 0), 0);
4205 arg = build2 (COMPOUND_EXPR, TREE_TYPE (real_result),
4207 TREE_NO_WARNING (arg) = 1;
4211 if (TREE_CODE (TREE_TYPE (arg)) == FUNCTION_TYPE
4212 || TREE_CODE (TREE_TYPE (arg)) == METHOD_TYPE
4213 || TREE_CODE (arg) == OFFSET_REF)
4217 gcc_assert (TREE_CODE (arg) != SCOPE_REF);
4219 if (TREE_CODE (arg) != OFFSET_REF)
4222 t = TREE_OPERAND (arg, 1);
4224 /* Check all this code for right semantics. */
4225 if (TREE_CODE (t) == FUNCTION_DECL)
4227 if (DECL_DESTRUCTOR_P (t))
4228 error ("taking address of destructor");
4229 return build_unary_op (ADDR_EXPR, t, 0);
4231 if (TREE_CODE (t) == VAR_DECL)
4232 return build_unary_op (ADDR_EXPR, t, 0);
4237 if (TREE_OPERAND (arg, 0)
4238 && ! is_dummy_object (TREE_OPERAND (arg, 0))
4239 && TREE_CODE (t) != FIELD_DECL)
4241 error ("taking address of bound pointer-to-member expression");
4242 return error_mark_node;
4244 if (!PTRMEM_OK_P (arg))
4245 return build_unary_op (code, arg, 0);
4247 if (TREE_CODE (TREE_TYPE (t)) == REFERENCE_TYPE)
4249 error ("cannot create pointer to reference member %qD", t);
4250 return error_mark_node;
4253 type = build_ptrmem_type (context_for_name_lookup (t),
4255 t = make_ptrmem_cst (type, TREE_OPERAND (arg, 1));
4261 /* We permit compiler to make function calls returning
4262 objects of aggregate type look like lvalues. */
4266 if (TREE_CODE (targ) == SAVE_EXPR)
4267 targ = TREE_OPERAND (targ, 0);
4269 if (TREE_CODE (targ) == CALL_EXPR && IS_AGGR_TYPE (TREE_TYPE (targ)))
4271 if (TREE_CODE (arg) == SAVE_EXPR)
4274 targ = build_cplus_new (TREE_TYPE (arg), arg);
4275 return build1 (ADDR_EXPR, build_pointer_type (TREE_TYPE (arg)), targ);
4278 if (TREE_CODE (arg) == SAVE_EXPR && TREE_CODE (targ) == INDIRECT_REF)
4279 return build3 (SAVE_EXPR, build_pointer_type (TREE_TYPE (arg)),
4280 TREE_OPERAND (targ, 0), current_function_decl, NULL);
4283 /* Don't let anything else be handled specially. */
4287 /* Mark EXP saying that we need to be able to take the
4288 address of it; it should not be allocated in a register.
4289 Value is true if successful.
4291 C++: we do not allow `current_class_ptr' to be addressable. */
4294 cxx_mark_addressable (tree exp)
4299 switch (TREE_CODE (x))
4306 x = TREE_OPERAND (x, 0);
4310 if (x == current_class_ptr)
4312 error ("cannot take the address of %<this%>, which is an rvalue expression");
4313 TREE_ADDRESSABLE (x) = 1; /* so compiler doesn't die later. */
4319 /* Caller should not be trying to mark initialized
4320 constant fields addressable. */
4321 gcc_assert (DECL_LANG_SPECIFIC (x) == 0
4322 || DECL_IN_AGGR_P (x) == 0
4324 || DECL_EXTERNAL (x));
4329 if (DECL_REGISTER (x) && !TREE_ADDRESSABLE (x)
4330 && !DECL_ARTIFICIAL (x))
4332 if (DECL_HARD_REGISTER (x) != 0)
4335 ("address of explicit register variable %qD requested", x);
4338 else if (extra_warnings)
4340 ("address requested for %qD, which is declared %<register%>", x);
4342 TREE_ADDRESSABLE (x) = 1;
4346 TREE_ADDRESSABLE (x) = 1;
4350 TREE_ADDRESSABLE (x) = 1;
4354 TREE_ADDRESSABLE (x) = 1;
4355 cxx_mark_addressable (TREE_OPERAND (x, 0));
4363 /* Build and return a conditional expression IFEXP ? OP1 : OP2. */
4366 build_x_conditional_expr (tree ifexp, tree op1, tree op2)
4368 tree orig_ifexp = ifexp;
4369 tree orig_op1 = op1;
4370 tree orig_op2 = op2;
4373 if (processing_template_decl)
4375 /* The standard says that the expression is type-dependent if
4376 IFEXP is type-dependent, even though the eventual type of the
4377 expression doesn't dependent on IFEXP. */
4378 if (type_dependent_expression_p (ifexp)
4379 /* As a GNU extension, the middle operand may be omitted. */
4380 || (op1 && type_dependent_expression_p (op1))
4381 || type_dependent_expression_p (op2))
4382 return build_min_nt (COND_EXPR, ifexp, op1, op2);
4383 ifexp = build_non_dependent_expr (ifexp);
4385 op1 = build_non_dependent_expr (op1);
4386 op2 = build_non_dependent_expr (op2);
4389 expr = build_conditional_expr (ifexp, op1, op2);
4390 if (processing_template_decl && expr != error_mark_node)
4391 return build_min_non_dep (COND_EXPR, expr,
4392 orig_ifexp, orig_op1, orig_op2);
4396 /* Given a list of expressions, return a compound expression
4397 that performs them all and returns the value of the last of them. */
4399 tree build_x_compound_expr_from_list (tree list, const char *msg)
4401 tree expr = TREE_VALUE (list);
4403 if (TREE_CHAIN (list))
4406 pedwarn ("%s expression list treated as compound expression", msg);
4408 for (list = TREE_CHAIN (list); list; list = TREE_CHAIN (list))
4409 expr = build_x_compound_expr (expr, TREE_VALUE (list));
4415 /* Handle overloading of the ',' operator when needed. */
4418 build_x_compound_expr (tree op1, tree op2)
4421 tree orig_op1 = op1;
4422 tree orig_op2 = op2;
4424 if (processing_template_decl)
4426 if (type_dependent_expression_p (op1)
4427 || type_dependent_expression_p (op2))
4428 return build_min_nt (COMPOUND_EXPR, op1, op2);
4429 op1 = build_non_dependent_expr (op1);
4430 op2 = build_non_dependent_expr (op2);
4433 result = build_new_op (COMPOUND_EXPR, LOOKUP_NORMAL, op1, op2, NULL_TREE,
4434 /*overloaded_p=*/NULL);
4436 result = build_compound_expr (op1, op2);
4438 if (processing_template_decl && result != error_mark_node)
4439 return build_min_non_dep (COMPOUND_EXPR, result, orig_op1, orig_op2);
4444 /* Build a compound expression. */
4447 build_compound_expr (tree lhs, tree rhs)
4449 lhs = convert_to_void (lhs, "left-hand operand of comma");
4451 if (lhs == error_mark_node || rhs == error_mark_node)
4452 return error_mark_node;
4454 if (TREE_CODE (rhs) == TARGET_EXPR)
4456 /* If the rhs is a TARGET_EXPR, then build the compound
4457 expression inside the target_expr's initializer. This
4458 helps the compiler to eliminate unnecessary temporaries. */
4459 tree init = TREE_OPERAND (rhs, 1);
4461 init = build2 (COMPOUND_EXPR, TREE_TYPE (init), lhs, init);
4462 TREE_OPERAND (rhs, 1) = init;
4467 return build2 (COMPOUND_EXPR, TREE_TYPE (rhs), lhs, rhs);
4470 /* Issue a diagnostic message if casting from SRC_TYPE to DEST_TYPE
4471 casts away constness. DIAG_FN gives the function to call if we
4472 need to issue a diagnostic; if it is NULL, no diagnostic will be
4473 issued. DESCRIPTION explains what operation is taking place. */
4476 check_for_casting_away_constness (tree src_type, tree dest_type,
4477 void (*diag_fn)(const char *, ...),
4478 const char *description)
4480 if (diag_fn && casts_away_constness (src_type, dest_type))
4481 error ("%s from type %qT to type %qT casts away constness",
4482 description, src_type, dest_type);
4485 /* Convert EXPR (an expression with pointer-to-member type) to TYPE
4486 (another pointer-to-member type in the same hierarchy) and return
4487 the converted expression. If ALLOW_INVERSE_P is permitted, a
4488 pointer-to-derived may be converted to pointer-to-base; otherwise,
4489 only the other direction is permitted. If C_CAST_P is true, this
4490 conversion is taking place as part of a C-style cast. */
4493 convert_ptrmem (tree type, tree expr, bool allow_inverse_p,
4496 if (TYPE_PTRMEM_P (type))
4500 if (TREE_CODE (expr) == PTRMEM_CST)
4501 expr = cplus_expand_constant (expr);
4502 delta = get_delta_difference (TYPE_PTRMEM_CLASS_TYPE (TREE_TYPE (expr)),
4503 TYPE_PTRMEM_CLASS_TYPE (type),
4506 if (!integer_zerop (delta))
4507 expr = cp_build_binary_op (PLUS_EXPR,
4508 build_nop (ptrdiff_type_node, expr),
4510 return build_nop (type, expr);
4513 return build_ptrmemfunc (TYPE_PTRMEMFUNC_FN_TYPE (type), expr,
4514 allow_inverse_p, c_cast_p);
4517 /* Perform a static_cast from EXPR to TYPE. When C_CAST_P is true,
4518 this static_cast is being attempted as one of the possible casts
4519 allowed by a C-style cast. (In that case, accessibility of base
4520 classes is not considered, and it is OK to cast away
4521 constness.) Return the result of the cast. *VALID_P is set to
4522 indicate whether or not the cast was valid. */
4525 build_static_cast_1 (tree type, tree expr, bool c_cast_p,
4531 void (*diag_fn)(const char*, ...);
4534 /* Assume the cast is valid. */
4537 intype = TREE_TYPE (expr);
4539 /* Determine what to do when casting away constness. */
4542 /* C-style casts are allowed to cast away constness. With
4543 WARN_CAST_QUAL, we still want to issue a warning. */
4544 diag_fn = warn_cast_qual ? warning : NULL;
4549 /* A static_cast may not cast away constness. */
4551 desc = "static_cast";
4554 /* [expr.static.cast]
4556 An lvalue of type "cv1 B", where B is a class type, can be cast
4557 to type "reference to cv2 D", where D is a class derived (clause
4558 _class.derived_) from B, if a valid standard conversion from
4559 "pointer to D" to "pointer to B" exists (_conv.ptr_), cv2 is the
4560 same cv-qualification as, or greater cv-qualification than, cv1,
4561 and B is not a virtual base class of D. */
4562 /* We check this case before checking the validity of "TYPE t =
4563 EXPR;" below because for this case:
4566 struct D : public B { D(const B&); };
4568 void f() { static_cast<const D&>(b); }
4570 we want to avoid constructing a new D. The standard is not
4571 completely clear about this issue, but our interpretation is
4572 consistent with other compilers. */
4573 if (TREE_CODE (type) == REFERENCE_TYPE
4574 && CLASS_TYPE_P (TREE_TYPE (type))
4575 && CLASS_TYPE_P (intype)
4576 && real_lvalue_p (expr)
4577 && DERIVED_FROM_P (intype, TREE_TYPE (type))
4578 && can_convert (build_pointer_type (TYPE_MAIN_VARIANT (intype)),
4579 build_pointer_type (TYPE_MAIN_VARIANT
4580 (TREE_TYPE (type))))
4582 || at_least_as_qualified_p (TREE_TYPE (type), intype)))
4586 /* There is a standard conversion from "D*" to "B*" even if "B"
4587 is ambiguous or inaccessible. If this is really a
4588 static_cast, then we check both for inaccessibility and
4589 ambiguity. However, if this is a static_cast being performed
4590 because the user wrote a C-style cast, then accessibility is
4592 base = lookup_base (TREE_TYPE (type), intype,
4593 c_cast_p ? ba_unique : ba_check,
4596 /* Convert from "B*" to "D*". This function will check that "B"
4597 is not a virtual base of "D". */
4598 expr = build_base_path (MINUS_EXPR, build_address (expr),
4599 base, /*nonnull=*/false);
4600 /* Convert the pointer to a reference -- but then remember that
4601 there are no expressions with reference type in C++. */
4602 return convert_from_reference (build_nop (type, expr));
4607 /* [expr.static.cast]
4609 An expression e can be explicitly converted to a type T using a
4610 static_cast of the form static_cast<T>(e) if the declaration T
4611 t(e);" is well-formed, for some invented temporary variable
4613 result = perform_direct_initialization_if_possible (type, expr,
4617 result = convert_from_reference (result);
4619 /* Ignore any integer overflow caused by the cast. */
4620 if (TREE_CODE (result) == INTEGER_CST
4621 && CONSTANT_CLASS_P (orig))
4623 TREE_OVERFLOW (result) = TREE_OVERFLOW (orig);
4624 TREE_CONSTANT_OVERFLOW (result)
4625 = TREE_CONSTANT_OVERFLOW (orig);
4627 /* [expr.static.cast]
4629 If T is a reference type, the result is an lvalue; otherwise,
4630 the result is an rvalue. */
4631 if (TREE_CODE (type) != REFERENCE_TYPE
4632 && real_lvalue_p (result))
4633 result = build1 (NON_LVALUE_EXPR, TREE_TYPE (result), result);
4637 /* [expr.static.cast]
4639 Any expression can be explicitly converted to type cv void. */
4640 if (TREE_CODE (type) == VOID_TYPE)
4641 return convert_to_void (expr, /*implicit=*/NULL);
4643 /* [expr.static.cast]
4645 The inverse of any standard conversion sequence (clause _conv_),
4646 other than the lvalue-to-rvalue (_conv.lval_), array-to-pointer
4647 (_conv.array_), function-to-pointer (_conv.func_), and boolean
4648 (_conv.bool_) conversions, can be performed explicitly using
4649 static_cast subject to the restriction that the explicit
4650 conversion does not cast away constness (_expr.const.cast_), and
4651 the following additional rules for specific cases: */
4652 /* For reference, the conversions not excluded are: integral
4653 promotions, floating point promotion, integral conversions,
4654 floating point conversions, floating-integral conversions,
4655 pointer conversions, and pointer to member conversions. */
4656 if ((ARITHMETIC_TYPE_P (type) && ARITHMETIC_TYPE_P (intype))
4659 A value of integral _or enumeration_ type can be explicitly
4660 converted to an enumeration type. */
4661 || (INTEGRAL_OR_ENUMERATION_TYPE_P (type)
4662 && INTEGRAL_OR_ENUMERATION_TYPE_P (intype)))
4664 expr = ocp_convert (type, expr, CONV_C_CAST, LOOKUP_NORMAL);
4666 /* Ignore any integer overflow caused by the cast. */
4667 if (TREE_CODE (expr) == INTEGER_CST
4668 && CONSTANT_CLASS_P (orig))
4670 TREE_OVERFLOW (expr) = TREE_OVERFLOW (orig);
4671 TREE_CONSTANT_OVERFLOW (expr) = TREE_CONSTANT_OVERFLOW (orig);
4676 if (TYPE_PTR_P (type) && TYPE_PTR_P (intype)
4677 && CLASS_TYPE_P (TREE_TYPE (type))
4678 && CLASS_TYPE_P (TREE_TYPE (intype))
4679 && can_convert (build_pointer_type (TYPE_MAIN_VARIANT
4680 (TREE_TYPE (intype))),
4681 build_pointer_type (TYPE_MAIN_VARIANT
4682 (TREE_TYPE (type)))))
4687 check_for_casting_away_constness (intype, type, diag_fn, desc);
4688 base = lookup_base (TREE_TYPE (type), TREE_TYPE (intype),
4689 c_cast_p ? ba_unique : ba_check,
4691 return build_base_path (MINUS_EXPR, expr, base, /*nonnull=*/false);
4694 if ((TYPE_PTRMEM_P (type) && TYPE_PTRMEM_P (intype))
4695 || (TYPE_PTRMEMFUNC_P (type) && TYPE_PTRMEMFUNC_P (intype)))
4702 c1 = TYPE_PTRMEM_CLASS_TYPE (intype);
4703 c2 = TYPE_PTRMEM_CLASS_TYPE (type);
4705 if (TYPE_PTRMEM_P (type))
4707 t1 = (build_ptrmem_type
4709 TYPE_MAIN_VARIANT (TYPE_PTRMEM_POINTED_TO_TYPE (intype))));
4710 t2 = (build_ptrmem_type
4712 TYPE_MAIN_VARIANT (TYPE_PTRMEM_POINTED_TO_TYPE (type))));
4719 if (can_convert (t1, t2))
4722 check_for_casting_away_constness (intype, type, diag_fn,
4724 return convert_ptrmem (type, expr, /*allow_inverse_p=*/1,
4729 /* [expr.static.cast]
4731 An rvalue of type "pointer to cv void" can be explicitly
4732 converted to a pointer to object type. A value of type pointer
4733 to object converted to "pointer to cv void" and back to the
4734 original pointer type will have its original value. */
4735 if (TREE_CODE (intype) == POINTER_TYPE
4736 && VOID_TYPE_P (TREE_TYPE (intype))
4737 && TYPE_PTROB_P (type))
4740 check_for_casting_away_constness (intype, type, diag_fn, desc);
4741 return build_nop (type, expr);
4745 return error_mark_node;
4748 /* Return an expression representing static_cast<TYPE>(EXPR). */
4751 build_static_cast (tree type, tree expr)
4756 if (type == error_mark_node || expr == error_mark_node)
4757 return error_mark_node;
4759 if (processing_template_decl)
4761 expr = build_min (STATIC_CAST_EXPR, type, expr);
4762 /* We don't know if it will or will not have side effects. */
4763 TREE_SIDE_EFFECTS (expr) = 1;
4764 return convert_from_reference (expr);
4767 /* build_c_cast puts on a NOP_EXPR to make the result not an lvalue.
4768 Strip such NOP_EXPRs if VALUE is being used in non-lvalue context. */
4769 if (TREE_CODE (type) != REFERENCE_TYPE
4770 && TREE_CODE (expr) == NOP_EXPR
4771 && TREE_TYPE (expr) == TREE_TYPE (TREE_OPERAND (expr, 0)))
4772 expr = TREE_OPERAND (expr, 0);
4774 result = build_static_cast_1 (type, expr, /*c_cast_p=*/false, &valid_p);
4778 error ("invalid static_cast from type %qT to type %qT",
4779 TREE_TYPE (expr), type);
4780 return error_mark_node;
4783 /* EXPR is an expression with member function or pointer-to-member
4784 function type. TYPE is a pointer type. Converting EXPR to TYPE is
4785 not permitted by ISO C++, but we accept it in some modes. If we
4786 are not in one of those modes, issue a diagnostic. Return the
4787 converted expression. */
4790 convert_member_func_to_ptr (tree type, tree expr)
4795 intype = TREE_TYPE (expr);
4796 gcc_assert (TYPE_PTRMEMFUNC_P (intype)
4797 || TREE_CODE (intype) == METHOD_TYPE);
4799 if (pedantic || warn_pmf2ptr)
4800 pedwarn ("converting from %qT to %qT", intype, type);
4802 if (TREE_CODE (intype) == METHOD_TYPE)
4803 expr = build_addr_func (expr);
4804 else if (TREE_CODE (expr) == PTRMEM_CST)
4805 expr = build_address (PTRMEM_CST_MEMBER (expr));
4808 decl = maybe_dummy_object (TYPE_PTRMEM_CLASS_TYPE (intype), 0);
4809 decl = build_address (decl);
4810 expr = get_member_function_from_ptrfunc (&decl, expr);
4813 return build_nop (type, expr);
4816 /* Return a representation for a reinterpret_cast from EXPR to TYPE.
4817 If C_CAST_P is true, this reinterpret cast is being done as part of
4818 a C-style cast. If VALID_P is non-NULL, *VALID_P is set to
4819 indicate whether or not reinterpret_cast was valid. */
4822 build_reinterpret_cast_1 (tree type, tree expr, bool c_cast_p,
4827 /* Assume the cast is invalid. */
4831 if (type == error_mark_node || error_operand_p (expr))
4832 return error_mark_node;
4834 intype = TREE_TYPE (expr);
4836 /* [expr.reinterpret.cast]
4837 An lvalue expression of type T1 can be cast to the type
4838 "reference to T2" if an expression of type "pointer to T1" can be
4839 explicitly converted to the type "pointer to T2" using a
4840 reinterpret_cast. */
4841 if (TREE_CODE (type) == REFERENCE_TYPE)
4843 if (! real_lvalue_p (expr))
4845 error ("invalid cast of an rvalue expression of type "
4848 return error_mark_node;
4851 /* Warn about a reinterpret_cast from "A*" to "B&" if "A" and
4852 "B" are related class types; the reinterpret_cast does not
4853 adjust the pointer. */
4854 if (TYPE_PTR_P (intype)
4855 && (comptypes (TREE_TYPE (intype), TREE_TYPE (type),
4856 COMPARE_BASE | COMPARE_DERIVED)))
4857 warning ("casting %qT to %qT does not dereference pointer",
4860 expr = build_unary_op (ADDR_EXPR, expr, 0);
4861 if (expr != error_mark_node)
4862 expr = build_reinterpret_cast_1
4863 (build_pointer_type (TREE_TYPE (type)), expr, c_cast_p,
4865 if (expr != error_mark_node)
4866 expr = build_indirect_ref (expr, 0);
4870 /* As a G++ extension, we consider conversions from member
4871 functions, and pointers to member functions to
4872 pointer-to-function and pointer-to-void types. If
4873 -Wno-pmf-conversions has not been specified,
4874 convert_member_func_to_ptr will issue an error message. */
4875 if ((TYPE_PTRMEMFUNC_P (intype)
4876 || TREE_CODE (intype) == METHOD_TYPE)
4877 && TYPE_PTR_P (type)
4878 && (TREE_CODE (TREE_TYPE (type)) == FUNCTION_TYPE
4879 || VOID_TYPE_P (TREE_TYPE (type))))
4880 return convert_member_func_to_ptr (type, expr);
4882 /* If the cast is not to a reference type, the lvalue-to-rvalue,
4883 array-to-pointer, and function-to-pointer conversions are
4885 expr = decay_conversion (expr);
4887 /* build_c_cast puts on a NOP_EXPR to make the result not an lvalue.
4888 Strip such NOP_EXPRs if VALUE is being used in non-lvalue context. */
4889 if (TREE_CODE (expr) == NOP_EXPR
4890 && TREE_TYPE (expr) == TREE_TYPE (TREE_OPERAND (expr, 0)))
4891 expr = TREE_OPERAND (expr, 0);
4893 if (error_operand_p (expr))
4894 return error_mark_node;
4896 intype = TREE_TYPE (expr);
4898 /* [expr.reinterpret.cast]
4899 A pointer can be converted to any integral type large enough to
4901 if (CP_INTEGRAL_TYPE_P (type) && TYPE_PTR_P (intype))
4903 if (TYPE_PRECISION (type) < TYPE_PRECISION (intype))
4904 pedwarn ("cast from %qT to %qT loses precision",
4907 /* [expr.reinterpret.cast]
4908 A value of integral or enumeration type can be explicitly
4909 converted to a pointer. */
4910 else if (TYPE_PTR_P (type) && INTEGRAL_OR_ENUMERATION_TYPE_P (intype))
4913 else if ((TYPE_PTRFN_P (type) && TYPE_PTRFN_P (intype))
4914 || (TYPE_PTRMEMFUNC_P (type) && TYPE_PTRMEMFUNC_P (intype)))
4915 return fold_if_not_in_template (build_nop (type, expr));
4916 else if ((TYPE_PTRMEM_P (type) && TYPE_PTRMEM_P (intype))
4917 || (TYPE_PTROBV_P (type) && TYPE_PTROBV_P (intype)))
4920 check_for_casting_away_constness (intype, type, error,
4921 "reinterpret_cast");
4922 /* Warn about possible alignment problems. */
4923 if (STRICT_ALIGNMENT && warn_cast_align
4924 && !VOID_TYPE_P (type)
4925 && TREE_CODE (TREE_TYPE (intype)) != FUNCTION_TYPE
4926 && COMPLETE_TYPE_P (TREE_TYPE (type))
4927 && COMPLETE_TYPE_P (TREE_TYPE (intype))
4928 && TYPE_ALIGN (TREE_TYPE (type)) > TYPE_ALIGN (TREE_TYPE (intype)))
4929 warning ("cast from %qT to %qT increases required alignment of "
4933 return fold_if_not_in_template (build_nop (type, expr));
4935 else if ((TYPE_PTRFN_P (type) && TYPE_PTROBV_P (intype))
4936 || (TYPE_PTRFN_P (intype) && TYPE_PTROBV_P (type)))
4939 /* Only issue a warning, as we have always supported this
4940 where possible, and it is necessary in some cases. DR 195
4941 addresses this issue, but as of 2004/10/26 is still in
4943 warning ("ISO C++ forbids casting between pointer-to-function and pointer-to-object");
4944 return fold_if_not_in_template (build_nop (type, expr));
4946 else if (TREE_CODE (type) == VECTOR_TYPE)
4947 return fold_if_not_in_template (convert_to_vector (type, expr));
4948 else if (TREE_CODE (intype) == VECTOR_TYPE)
4949 return fold_if_not_in_template (convert_to_integer (type, expr));
4954 error ("invalid cast from type %qT to type %qT", intype, type);
4955 return error_mark_node;
4958 return cp_convert (type, expr);
4962 build_reinterpret_cast (tree type, tree expr)
4964 if (type == error_mark_node || expr == error_mark_node)
4965 return error_mark_node;
4967 if (processing_template_decl)
4969 tree t = build_min (REINTERPRET_CAST_EXPR, type, expr);
4971 if (!TREE_SIDE_EFFECTS (t)
4972 && type_dependent_expression_p (expr))
4973 /* There might turn out to be side effects inside expr. */
4974 TREE_SIDE_EFFECTS (t) = 1;
4975 return convert_from_reference (t);
4978 return build_reinterpret_cast_1 (type, expr, /*c_cast_p=*/false,
4982 /* Perform a const_cast from EXPR to TYPE. If the cast is valid,
4983 return an appropriate expression. Otherwise, return
4984 error_mark_node. If the cast is not valid, and COMPLAIN is true,
4985 then a diagnostic will be issued. If VALID_P is non-NULL, its
4986 value upon return will indicate whether or not the conversion
4990 build_const_cast_1 (tree dst_type, tree expr, bool complain,
4994 tree reference_type;
4996 /* Callers are responsible for handling error_mark_node as a
4997 destination type. */
4998 gcc_assert (dst_type != error_mark_node);
4999 /* In a template, callers should be building syntactic
5000 representations of casts, not using this machinery. */
5001 gcc_assert (!processing_template_decl);
5003 /* Assume the conversion is invalid. */
5007 if (!POINTER_TYPE_P (dst_type) && !TYPE_PTRMEM_P (dst_type))
5010 error ("invalid use of const_cast with type %qT, "
5011 "which is not a pointer, "
5012 "reference, nor a pointer-to-data-member type", dst_type);
5013 return error_mark_node;
5016 if (TREE_CODE (TREE_TYPE (dst_type)) == FUNCTION_TYPE)
5019 error ("invalid use of const_cast with type %qT, which is a pointer "
5020 "or reference to a function type", dst_type);
5021 return error_mark_node;
5024 src_type = TREE_TYPE (expr);
5025 /* Expressions do not really have reference types. */
5026 if (TREE_CODE (src_type) == REFERENCE_TYPE)
5027 src_type = TREE_TYPE (src_type);
5029 /* [expr.const.cast]
5031 An lvalue of type T1 can be explicitly converted to an lvalue of
5032 type T2 using the cast const_cast<T2&> (where T1 and T2 are object
5033 types) if a pointer to T1 can be explicitly converted to the type
5034 pointer to T2 using a const_cast. */
5035 if (TREE_CODE (dst_type) == REFERENCE_TYPE)
5037 reference_type = dst_type;
5038 if (! real_lvalue_p (expr))
5041 error ("invalid const_cast of an rvalue of type %qT to type %qT",
5042 src_type, dst_type);
5043 return error_mark_node;
5045 dst_type = build_pointer_type (TREE_TYPE (dst_type));
5046 src_type = build_pointer_type (src_type);
5050 reference_type = NULL_TREE;
5051 /* If the destination type is not a reference type, the
5052 lvalue-to-rvalue, array-to-pointer, and function-to-pointer
5053 conversions are performed. */
5054 src_type = type_decays_to (src_type);
5055 if (src_type == error_mark_node)
5056 return error_mark_node;
5059 if ((TYPE_PTR_P (src_type) || TYPE_PTRMEM_P (src_type))
5060 && comp_ptr_ttypes_const (dst_type, src_type))
5066 expr = build_unary_op (ADDR_EXPR, expr, 0);
5067 expr = build_nop (reference_type, expr);
5068 return convert_from_reference (expr);
5072 expr = decay_conversion (expr);
5073 /* build_c_cast puts on a NOP_EXPR to make the result not an
5074 lvalue. Strip such NOP_EXPRs if VALUE is being used in
5075 non-lvalue context. */
5076 if (TREE_CODE (expr) == NOP_EXPR
5077 && TREE_TYPE (expr) == TREE_TYPE (TREE_OPERAND (expr, 0)))
5078 expr = TREE_OPERAND (expr, 0);
5079 return build_nop (dst_type, expr);
5084 error ("invalid const_cast from type %qT to type %qT",
5085 src_type, dst_type);
5086 return error_mark_node;
5090 build_const_cast (tree type, tree expr)
5092 if (type == error_mark_node || error_operand_p (expr))
5093 return error_mark_node;
5095 if (processing_template_decl)
5097 tree t = build_min (CONST_CAST_EXPR, type, expr);
5099 if (!TREE_SIDE_EFFECTS (t)
5100 && type_dependent_expression_p (expr))
5101 /* There might turn out to be side effects inside expr. */
5102 TREE_SIDE_EFFECTS (t) = 1;
5103 return convert_from_reference (t);
5106 return build_const_cast_1 (type, expr, /*complain=*/true,
5110 /* Build an expression representing an explicit C-style cast to type
5111 TYPE of expression EXPR. */
5114 build_c_cast (tree type, tree expr)
5120 if (type == error_mark_node || error_operand_p (expr))
5121 return error_mark_node;
5123 if (processing_template_decl)
5125 tree t = build_min (CAST_EXPR, type,
5126 tree_cons (NULL_TREE, value, NULL_TREE));
5127 /* We don't know if it will or will not have side effects. */
5128 TREE_SIDE_EFFECTS (t) = 1;
5129 return convert_from_reference (t);
5132 /* Casts to a (pointer to a) specific ObjC class (or 'id' or
5133 'Class') should always be retained, because this information aids
5134 in method lookup. */
5135 if (objc_is_object_ptr (type)
5136 && objc_is_object_ptr (TREE_TYPE (expr)))
5137 return build_nop (type, expr);
5139 /* build_c_cast puts on a NOP_EXPR to make the result not an lvalue.
5140 Strip such NOP_EXPRs if VALUE is being used in non-lvalue context. */
5141 if (TREE_CODE (type) != REFERENCE_TYPE
5142 && TREE_CODE (value) == NOP_EXPR
5143 && TREE_TYPE (value) == TREE_TYPE (TREE_OPERAND (value, 0)))
5144 value = TREE_OPERAND (value, 0);
5146 if (TREE_CODE (type) == ARRAY_TYPE)
5148 /* Allow casting from T1* to T2[] because Cfront allows it.
5149 NIHCL uses it. It is not valid ISO C++ however. */
5150 if (TREE_CODE (TREE_TYPE (expr)) == POINTER_TYPE)
5152 pedwarn ("ISO C++ forbids casting to an array type %qT", type);
5153 type = build_pointer_type (TREE_TYPE (type));
5157 error ("ISO C++ forbids casting to an array type %qT", type);
5158 return error_mark_node;
5162 if (TREE_CODE (type) == FUNCTION_TYPE
5163 || TREE_CODE (type) == METHOD_TYPE)
5165 error ("invalid cast to function type %qT", type);
5166 return error_mark_node;
5169 /* A C-style cast can be a const_cast. */
5170 result = build_const_cast_1 (type, value, /*complain=*/false,
5175 /* Or a static cast. */
5176 result = build_static_cast_1 (type, value, /*c_cast_p=*/true,
5178 /* Or a reinterpret_cast. */
5180 result = build_reinterpret_cast_1 (type, value, /*c_cast_p=*/true,
5182 /* The static_cast or reinterpret_cast may be followed by a
5185 /* A valid cast may result in errors if, for example, a
5186 conversion to am ambiguous base class is required. */
5187 && !error_operand_p (result))
5191 /* Non-class rvalues always have cv-unqualified type. */
5192 if (!CLASS_TYPE_P (type))
5193 type = TYPE_MAIN_VARIANT (type);
5194 result_type = TREE_TYPE (result);
5195 if (!CLASS_TYPE_P (result_type))
5196 result_type = TYPE_MAIN_VARIANT (result_type);
5197 /* If the type of RESULT does not match TYPE, perform a
5198 const_cast to make it match. If the static_cast or
5199 reinterpret_cast succeeded, we will differ by at most
5200 cv-qualification, so the follow-on const_cast is guaranteed
5202 if (!same_type_p (non_reference (type), non_reference (result_type)))
5204 result = build_const_cast_1 (type, result, false, &valid_p);
5205 gcc_assert (valid_p);
5210 return error_mark_node;
5213 /* Build an assignment expression of lvalue LHS from value RHS.
5214 MODIFYCODE is the code for a binary operator that we use
5215 to combine the old value of LHS with RHS to get the new value.
5216 Or else MODIFYCODE is NOP_EXPR meaning do a simple assignment.
5218 C++: If MODIFYCODE is INIT_EXPR, then leave references unbashed. */
5221 build_modify_expr (tree lhs, enum tree_code modifycode, tree rhs)
5225 tree lhstype = TREE_TYPE (lhs);
5226 tree olhstype = lhstype;
5227 tree olhs = NULL_TREE;
5228 bool plain_assign = (modifycode == NOP_EXPR);
5230 /* Avoid duplicate error messages from operands that had errors. */
5231 if (lhs == error_mark_node || rhs == error_mark_node)
5232 return error_mark_node;
5234 /* Handle control structure constructs used as "lvalues". */
5235 switch (TREE_CODE (lhs))
5237 /* Handle --foo = 5; as these are valid constructs in C++. */
5238 case PREDECREMENT_EXPR:
5239 case PREINCREMENT_EXPR:
5240 if (TREE_SIDE_EFFECTS (TREE_OPERAND (lhs, 0)))
5241 lhs = build2 (TREE_CODE (lhs), TREE_TYPE (lhs),
5242 stabilize_reference (TREE_OPERAND (lhs, 0)),
5243 TREE_OPERAND (lhs, 1));
5244 return build2 (COMPOUND_EXPR, lhstype,
5246 build_modify_expr (TREE_OPERAND (lhs, 0),
5249 /* Handle (a, b) used as an "lvalue". */
5251 newrhs = build_modify_expr (TREE_OPERAND (lhs, 1),
5253 if (newrhs == error_mark_node)
5254 return error_mark_node;
5255 return build2 (COMPOUND_EXPR, lhstype,
5256 TREE_OPERAND (lhs, 0), newrhs);
5259 if (TREE_SIDE_EFFECTS (TREE_OPERAND (lhs, 0)))
5260 lhs = build2 (TREE_CODE (lhs), TREE_TYPE (lhs),
5261 stabilize_reference (TREE_OPERAND (lhs, 0)),
5262 TREE_OPERAND (lhs, 1));
5263 newrhs = build_modify_expr (TREE_OPERAND (lhs, 0), modifycode, rhs);
5264 if (newrhs == error_mark_node)
5265 return error_mark_node;
5266 return build2 (COMPOUND_EXPR, lhstype, lhs, newrhs);
5270 /* MIN_EXPR and MAX_EXPR are currently only permitted as lvalues,
5271 when neither operand has side-effects. */
5272 if (!lvalue_or_else (lhs, lv_assign))
5273 return error_mark_node;
5275 gcc_assert (!TREE_SIDE_EFFECTS (TREE_OPERAND (lhs, 0))
5276 && !TREE_SIDE_EFFECTS (TREE_OPERAND (lhs, 1)));
5278 lhs = build3 (COND_EXPR, TREE_TYPE (lhs),
5279 build2 (TREE_CODE (lhs) == MIN_EXPR ? LE_EXPR : GE_EXPR,
5281 TREE_OPERAND (lhs, 0),
5282 TREE_OPERAND (lhs, 1)),
5283 TREE_OPERAND (lhs, 0),
5284 TREE_OPERAND (lhs, 1));
5287 /* Handle (a ? b : c) used as an "lvalue". */
5290 /* Produce (a ? (b = rhs) : (c = rhs))
5291 except that the RHS goes through a save-expr
5292 so the code to compute it is only emitted once. */
5294 tree preeval = NULL_TREE;
5296 rhs = stabilize_expr (rhs, &preeval);
5298 /* Check this here to avoid odd errors when trying to convert
5299 a throw to the type of the COND_EXPR. */
5300 if (!lvalue_or_else (lhs, lv_assign))
5301 return error_mark_node;
5303 cond = build_conditional_expr
5304 (TREE_OPERAND (lhs, 0),
5305 build_modify_expr (cp_convert (TREE_TYPE (lhs),
5306 TREE_OPERAND (lhs, 1)),
5308 build_modify_expr (cp_convert (TREE_TYPE (lhs),
5309 TREE_OPERAND (lhs, 2)),
5312 if (cond == error_mark_node)
5314 /* Make sure the code to compute the rhs comes out
5315 before the split. */
5317 cond = build2 (COMPOUND_EXPR, TREE_TYPE (lhs), preeval, cond);
5325 if (modifycode == INIT_EXPR)
5327 if (TREE_CODE (rhs) == CONSTRUCTOR)
5329 if (! same_type_p (TREE_TYPE (rhs), lhstype))
5330 /* Call convert to generate an error; see PR 11063. */
5331 rhs = convert (lhstype, rhs);
5332 result = build2 (INIT_EXPR, lhstype, lhs, rhs);
5333 TREE_SIDE_EFFECTS (result) = 1;
5336 else if (! IS_AGGR_TYPE (lhstype))
5337 /* Do the default thing. */;
5340 result = build_special_member_call (lhs, complete_ctor_identifier,
5341 build_tree_list (NULL_TREE, rhs),
5342 lhstype, LOOKUP_NORMAL);
5343 if (result == NULL_TREE)
5344 return error_mark_node;
5350 lhs = require_complete_type (lhs);
5351 if (lhs == error_mark_node)
5352 return error_mark_node;
5354 if (modifycode == NOP_EXPR)
5356 /* `operator=' is not an inheritable operator. */
5357 if (! IS_AGGR_TYPE (lhstype))
5358 /* Do the default thing. */;
5361 result = build_new_op (MODIFY_EXPR, LOOKUP_NORMAL,
5362 lhs, rhs, make_node (NOP_EXPR),
5363 /*overloaded_p=*/NULL);
5364 if (result == NULL_TREE)
5365 return error_mark_node;
5372 /* A binary op has been requested. Combine the old LHS
5373 value with the RHS producing the value we should actually
5374 store into the LHS. */
5376 gcc_assert (!PROMOTES_TO_AGGR_TYPE (lhstype, REFERENCE_TYPE));
5377 lhs = stabilize_reference (lhs);
5378 newrhs = cp_build_binary_op (modifycode, lhs, rhs);
5379 if (newrhs == error_mark_node)
5381 error (" in evaluation of %<%Q(%#T, %#T)%>", modifycode,
5382 TREE_TYPE (lhs), TREE_TYPE (rhs));
5383 return error_mark_node;
5386 /* Now it looks like a plain assignment. */
5387 modifycode = NOP_EXPR;
5389 gcc_assert (TREE_CODE (lhstype) != REFERENCE_TYPE);
5390 gcc_assert (TREE_CODE (TREE_TYPE (newrhs)) != REFERENCE_TYPE);
5393 /* The left-hand side must be an lvalue. */
5394 if (!lvalue_or_else (lhs, lv_assign))
5395 return error_mark_node;
5397 /* Warn about modifying something that is `const'. Don't warn if
5398 this is initialization. */
5399 if (modifycode != INIT_EXPR
5400 && (TREE_READONLY (lhs) || CP_TYPE_CONST_P (lhstype)
5401 /* Functions are not modifiable, even though they are
5403 || TREE_CODE (TREE_TYPE (lhs)) == FUNCTION_TYPE
5404 || TREE_CODE (TREE_TYPE (lhs)) == METHOD_TYPE
5405 /* If it's an aggregate and any field is const, then it is
5406 effectively const. */
5407 || (CLASS_TYPE_P (lhstype)
5408 && C_TYPE_FIELDS_READONLY (lhstype))))
5409 readonly_error (lhs, "assignment", 0);
5411 /* If storing into a structure or union member, it has probably been
5412 given type `int'. Compute the type that would go with the actual
5413 amount of storage the member occupies. */
5415 if (TREE_CODE (lhs) == COMPONENT_REF
5416 && (TREE_CODE (lhstype) == INTEGER_TYPE
5417 || TREE_CODE (lhstype) == REAL_TYPE
5418 || TREE_CODE (lhstype) == ENUMERAL_TYPE))
5420 lhstype = TREE_TYPE (get_unwidened (lhs, 0));
5422 /* If storing in a field that is in actuality a short or narrower
5423 than one, we must store in the field in its actual type. */
5425 if (lhstype != TREE_TYPE (lhs))
5427 /* Avoid warnings converting integral types back into enums for
5429 if (TREE_CODE (lhstype) == INTEGER_TYPE
5430 && TREE_CODE (olhstype) == ENUMERAL_TYPE)
5432 if (TREE_SIDE_EFFECTS (lhs))
5433 lhs = stabilize_reference (lhs);
5436 lhs = copy_node (lhs);
5437 TREE_TYPE (lhs) = lhstype;
5441 /* Convert new value to destination type. */
5443 if (TREE_CODE (lhstype) == ARRAY_TYPE)
5447 if (!same_or_base_type_p (TYPE_MAIN_VARIANT (lhstype),
5448 TYPE_MAIN_VARIANT (TREE_TYPE (rhs))))
5450 error ("incompatible types in assignment of %qT to %qT",
5451 TREE_TYPE (rhs), lhstype);
5452 return error_mark_node;
5455 /* Allow array assignment in compiler-generated code. */
5456 if (! DECL_ARTIFICIAL (current_function_decl))
5457 pedwarn ("ISO C++ forbids assignment of arrays");
5459 from_array = TREE_CODE (TREE_TYPE (newrhs)) == ARRAY_TYPE
5460 ? 1 + (modifycode != INIT_EXPR): 0;
5461 return build_vec_init (lhs, NULL_TREE, newrhs, from_array);
5464 if (modifycode == INIT_EXPR)
5465 newrhs = convert_for_initialization (lhs, lhstype, newrhs, LOOKUP_NORMAL,
5466 "initialization", NULL_TREE, 0);
5469 /* Avoid warnings on enum bit fields. */
5470 if (TREE_CODE (olhstype) == ENUMERAL_TYPE
5471 && TREE_CODE (lhstype) == INTEGER_TYPE)
5473 newrhs = convert_for_assignment (olhstype, newrhs, "assignment",
5475 newrhs = convert_force (lhstype, newrhs, 0);
5478 newrhs = convert_for_assignment (lhstype, newrhs, "assignment",
5480 if (TREE_CODE (newrhs) == CALL_EXPR
5481 && TYPE_NEEDS_CONSTRUCTING (lhstype))
5482 newrhs = build_cplus_new (lhstype, newrhs);
5484 /* Can't initialize directly from a TARGET_EXPR, since that would
5485 cause the lhs to be constructed twice, and possibly result in
5486 accidental self-initialization. So we force the TARGET_EXPR to be
5487 expanded without a target. */
5488 if (TREE_CODE (newrhs) == TARGET_EXPR)
5489 newrhs = build2 (COMPOUND_EXPR, TREE_TYPE (newrhs), newrhs,
5490 TREE_OPERAND (newrhs, 0));
5493 if (newrhs == error_mark_node)
5494 return error_mark_node;
5496 result = build2 (modifycode == NOP_EXPR ? MODIFY_EXPR : INIT_EXPR,
5497 lhstype, lhs, newrhs);
5499 TREE_SIDE_EFFECTS (result) = 1;
5501 TREE_NO_WARNING (result) = 1;
5503 /* If we got the LHS in a different type for storing in,
5504 convert the result back to the nominal type of LHS
5505 so that the value we return always has the same type
5506 as the LHS argument. */
5508 if (olhstype == TREE_TYPE (result))
5512 result = build2 (COMPOUND_EXPR, olhstype, result, olhs);
5513 TREE_NO_WARNING (result) = 1;
5516 return convert_for_assignment (olhstype, result, "assignment",
5521 build_x_modify_expr (tree lhs, enum tree_code modifycode, tree rhs)
5523 if (processing_template_decl)
5524 return build_min_nt (MODOP_EXPR, lhs,
5525 build_min_nt (modifycode, NULL_TREE, NULL_TREE), rhs);
5527 if (modifycode != NOP_EXPR)
5529 tree rval = build_new_op (MODIFY_EXPR, LOOKUP_NORMAL, lhs, rhs,
5530 make_node (modifycode),
5531 /*overloaded_p=*/NULL);
5534 TREE_NO_WARNING (rval) = 1;
5538 return build_modify_expr (lhs, modifycode, rhs);
5542 /* Get difference in deltas for different pointer to member function
5543 types. Returns an integer constant of type PTRDIFF_TYPE_NODE. If
5544 the conversion is invalid, the constant is zero. If
5545 ALLOW_INVERSE_P is true, then allow reverse conversions as well.
5546 If C_CAST_P is true this conversion is taking place as part of a
5549 Note that the naming of FROM and TO is kind of backwards; the return
5550 value is what we add to a TO in order to get a FROM. They are named
5551 this way because we call this function to find out how to convert from
5552 a pointer to member of FROM to a pointer to member of TO. */
5555 get_delta_difference (tree from, tree to,
5556 bool allow_inverse_p,
5564 /* Assume no conversion is required. */
5565 result = integer_zero_node;
5566 binfo = lookup_base (to, from, c_cast_p ? ba_unique : ba_check, &kind);
5567 if (kind == bk_inaccessible || kind == bk_ambig)
5568 error (" in pointer to member function conversion");
5571 if (!allow_inverse_p)
5573 error_not_base_type (from, to);
5574 error (" in pointer to member conversion");
5578 binfo = lookup_base (from, to, c_cast_p ? ba_unique : ba_check,
5582 virt_binfo = binfo_from_vbase (binfo);
5584 /* This is a reinterpret cast, we choose to do nothing. */
5585 warning ("pointer to member cast via virtual base %qT",
5586 BINFO_TYPE (virt_binfo));
5588 result = size_diffop (size_zero_node, BINFO_OFFSET (binfo));
5594 virt_binfo = binfo_from_vbase (binfo);
5596 result = BINFO_OFFSET (binfo);
5599 /* This is a reinterpret cast, we choose to do nothing. */
5600 if (allow_inverse_p)
5601 warning ("pointer to member cast via virtual base %qT",
5602 BINFO_TYPE (virt_binfo));
5604 error ("pointer to member conversion via virtual base %qT",
5605 BINFO_TYPE (virt_binfo));
5609 return fold_if_not_in_template (convert_to_integer (ptrdiff_type_node,
5613 /* Return a constructor for the pointer-to-member-function TYPE using
5614 the other components as specified. */
5617 build_ptrmemfunc1 (tree type, tree delta, tree pfn)
5623 /* Pull the FIELD_DECLs out of the type. */
5624 pfn_field = TYPE_FIELDS (type);
5625 delta_field = TREE_CHAIN (pfn_field);
5627 /* Make sure DELTA has the type we want. */
5628 delta = convert_and_check (delta_type_node, delta);
5630 /* Finish creating the initializer. */
5631 u = tree_cons (pfn_field, pfn,
5632 build_tree_list (delta_field, delta));
5633 u = build_constructor (type, u);
5634 TREE_CONSTANT (u) = TREE_CONSTANT (pfn) & TREE_CONSTANT (delta);
5635 TREE_INVARIANT (u) = TREE_INVARIANT (pfn) & TREE_INVARIANT (delta);
5636 TREE_STATIC (u) = (TREE_CONSTANT (u)
5637 && (initializer_constant_valid_p (pfn, TREE_TYPE (pfn))
5639 && (initializer_constant_valid_p (delta, TREE_TYPE (delta))
5644 /* Build a constructor for a pointer to member function. It can be
5645 used to initialize global variables, local variable, or used
5646 as a value in expressions. TYPE is the POINTER to METHOD_TYPE we
5649 If FORCE is nonzero, then force this conversion, even if
5650 we would rather not do it. Usually set when using an explicit
5651 cast. A C-style cast is being processed iff C_CAST_P is true.
5653 Return error_mark_node, if something goes wrong. */
5656 build_ptrmemfunc (tree type, tree pfn, int force, bool c_cast_p)
5662 if (error_operand_p (pfn))
5663 return error_mark_node;
5665 pfn_type = TREE_TYPE (pfn);
5666 to_type = build_ptrmemfunc_type (type);
5668 /* Handle multiple conversions of pointer to member functions. */
5669 if (TYPE_PTRMEMFUNC_P (pfn_type))
5671 tree delta = NULL_TREE;
5672 tree npfn = NULL_TREE;
5676 && !can_convert_arg (to_type, TREE_TYPE (pfn), pfn))
5677 error ("invalid conversion to type %qT from type %qT",
5680 n = get_delta_difference (TYPE_PTRMEMFUNC_OBJECT_TYPE (pfn_type),
5681 TYPE_PTRMEMFUNC_OBJECT_TYPE (to_type),
5685 /* We don't have to do any conversion to convert a
5686 pointer-to-member to its own type. But, we don't want to
5687 just return a PTRMEM_CST if there's an explicit cast; that
5688 cast should make the expression an invalid template argument. */
5689 if (TREE_CODE (pfn) != PTRMEM_CST)
5691 if (same_type_p (to_type, pfn_type))
5693 else if (integer_zerop (n))
5694 return build_reinterpret_cast (to_type, pfn);
5697 if (TREE_SIDE_EFFECTS (pfn))
5698 pfn = save_expr (pfn);
5700 /* Obtain the function pointer and the current DELTA. */
5701 if (TREE_CODE (pfn) == PTRMEM_CST)
5702 expand_ptrmemfunc_cst (pfn, &delta, &npfn);
5705 npfn = build_ptrmemfunc_access_expr (pfn, pfn_identifier);
5706 delta = build_ptrmemfunc_access_expr (pfn, delta_identifier);
5709 /* Just adjust the DELTA field. */
5710 gcc_assert (same_type_ignoring_top_level_qualifiers_p
5711 (TREE_TYPE (delta), ptrdiff_type_node));
5712 if (TARGET_PTRMEMFUNC_VBIT_LOCATION == ptrmemfunc_vbit_in_delta)
5713 n = cp_build_binary_op (LSHIFT_EXPR, n, integer_one_node);
5714 delta = cp_build_binary_op (PLUS_EXPR, delta, n);
5715 return build_ptrmemfunc1 (to_type, delta, npfn);
5718 /* Handle null pointer to member function conversions. */
5719 if (integer_zerop (pfn))
5721 pfn = build_c_cast (type, integer_zero_node);
5722 return build_ptrmemfunc1 (to_type,
5727 if (type_unknown_p (pfn))
5728 return instantiate_type (type, pfn, tf_error | tf_warning);
5730 fn = TREE_OPERAND (pfn, 0);
5731 gcc_assert (TREE_CODE (fn) == FUNCTION_DECL);
5732 return make_ptrmem_cst (to_type, fn);
5735 /* Return the DELTA, IDX, PFN, and DELTA2 values for the PTRMEM_CST
5738 ??? There is no consistency as to the types returned for the above
5739 values. Some code acts as if it were a sizetype and some as if it were
5740 integer_type_node. */
5743 expand_ptrmemfunc_cst (tree cst, tree *delta, tree *pfn)
5745 tree type = TREE_TYPE (cst);
5746 tree fn = PTRMEM_CST_MEMBER (cst);
5747 tree ptr_class, fn_class;
5749 gcc_assert (TREE_CODE (fn) == FUNCTION_DECL);
5751 /* The class that the function belongs to. */
5752 fn_class = DECL_CONTEXT (fn);
5754 /* The class that we're creating a pointer to member of. */
5755 ptr_class = TYPE_PTRMEMFUNC_OBJECT_TYPE (type);
5757 /* First, calculate the adjustment to the function's class. */
5758 *delta = get_delta_difference (fn_class, ptr_class, /*force=*/0,
5761 if (!DECL_VIRTUAL_P (fn))
5762 *pfn = convert (TYPE_PTRMEMFUNC_FN_TYPE (type), build_addr_func (fn));
5765 /* If we're dealing with a virtual function, we have to adjust 'this'
5766 again, to point to the base which provides the vtable entry for
5767 fn; the call will do the opposite adjustment. */
5768 tree orig_class = DECL_CONTEXT (fn);
5769 tree binfo = binfo_or_else (orig_class, fn_class);
5770 *delta = build2 (PLUS_EXPR, TREE_TYPE (*delta),
5771 *delta, BINFO_OFFSET (binfo));
5772 *delta = fold_if_not_in_template (*delta);
5774 /* We set PFN to the vtable offset at which the function can be
5775 found, plus one (unless ptrmemfunc_vbit_in_delta, in which
5776 case delta is shifted left, and then incremented). */
5777 *pfn = DECL_VINDEX (fn);
5778 *pfn = build2 (MULT_EXPR, integer_type_node, *pfn,
5779 TYPE_SIZE_UNIT (vtable_entry_type));
5780 *pfn = fold_if_not_in_template (*pfn);
5782 switch (TARGET_PTRMEMFUNC_VBIT_LOCATION)
5784 case ptrmemfunc_vbit_in_pfn:
5785 *pfn = build2 (PLUS_EXPR, integer_type_node, *pfn,
5787 *pfn = fold_if_not_in_template (*pfn);
5790 case ptrmemfunc_vbit_in_delta:
5791 *delta = build2 (LSHIFT_EXPR, TREE_TYPE (*delta),
5792 *delta, integer_one_node);
5793 *delta = fold_if_not_in_template (*delta);
5794 *delta = build2 (PLUS_EXPR, TREE_TYPE (*delta),
5795 *delta, integer_one_node);
5796 *delta = fold_if_not_in_template (*delta);
5803 *pfn = build_nop (TYPE_PTRMEMFUNC_FN_TYPE (type), *pfn);
5804 *pfn = fold_if_not_in_template (*pfn);
5808 /* Return an expression for PFN from the pointer-to-member function
5812 pfn_from_ptrmemfunc (tree t)
5814 if (TREE_CODE (t) == PTRMEM_CST)
5819 expand_ptrmemfunc_cst (t, &delta, &pfn);
5824 return build_ptrmemfunc_access_expr (t, pfn_identifier);
5827 /* Expression EXPR is about to be implicitly converted to TYPE. Warn
5828 if this is a potentially dangerous thing to do. Returns a possibly
5832 dubious_conversion_warnings (tree type, tree expr,
5833 const char *errtype, tree fndecl, int parmnum)
5835 type = non_reference (type);
5837 /* Issue warnings about peculiar, but valid, uses of NULL. */
5838 if (ARITHMETIC_TYPE_P (type) && expr == null_node)
5841 warning ("passing NULL used for non-pointer %s %P of %qD",
5842 errtype, parmnum, fndecl);
5844 warning ("%s to non-pointer type %qT from NULL", errtype, type);
5847 /* Warn about assigning a floating-point type to an integer type. */
5848 if (TREE_CODE (TREE_TYPE (expr)) == REAL_TYPE
5849 && TREE_CODE (type) == INTEGER_TYPE)
5852 warning ("passing %qT for %s %P of %qD",
5853 TREE_TYPE (expr), errtype, parmnum, fndecl);
5855 warning ("%s to %qT from %qT", errtype, type, TREE_TYPE (expr));
5857 /* And warn about assigning a negative value to an unsigned
5859 else if (TYPE_UNSIGNED (type) && TREE_CODE (type) != BOOLEAN_TYPE)
5861 if (TREE_CODE (expr) == INTEGER_CST && TREE_NEGATED_INT (expr))
5864 warning ("passing negative value %qE for %s %P of %qD",
5865 expr, errtype, parmnum, fndecl);
5867 warning ("%s of negative value %qE to %qT", errtype, expr, type);
5870 overflow_warning (expr);
5872 if (TREE_CONSTANT (expr))
5873 expr = fold_if_not_in_template (expr);
5878 /* Convert value RHS to type TYPE as preparation for an assignment to
5879 an lvalue of type TYPE. ERRTYPE is a string to use in error
5880 messages: "assignment", "return", etc. If FNDECL is non-NULL, we
5881 are doing the conversion in order to pass the PARMNUMth argument of
5885 convert_for_assignment (tree type, tree rhs,
5886 const char *errtype, tree fndecl, int parmnum)
5889 enum tree_code coder;
5891 /* Strip NON_LVALUE_EXPRs since we aren't using as an lvalue. */
5892 if (TREE_CODE (rhs) == NON_LVALUE_EXPR)
5893 rhs = TREE_OPERAND (rhs, 0);
5895 rhstype = TREE_TYPE (rhs);
5896 coder = TREE_CODE (rhstype);
5898 if (TREE_CODE (type) == VECTOR_TYPE && coder == VECTOR_TYPE
5899 && vector_types_convertible_p (type, rhstype))
5900 return convert (type, rhs);
5902 if (rhs == error_mark_node || rhstype == error_mark_node)
5903 return error_mark_node;
5904 if (TREE_CODE (rhs) == TREE_LIST && TREE_VALUE (rhs) == error_mark_node)
5905 return error_mark_node;
5907 /* The RHS of an assignment cannot have void type. */
5908 if (coder == VOID_TYPE)
5910 error ("void value not ignored as it ought to be");
5911 return error_mark_node;
5914 /* Simplify the RHS if possible. */
5915 if (TREE_CODE (rhs) == CONST_DECL)
5916 rhs = DECL_INITIAL (rhs);
5920 The expression is implicitly converted (clause _conv_) to the
5921 cv-unqualified type of the left operand.
5923 We allow bad conversions here because by the time we get to this point
5924 we are committed to doing the conversion. If we end up doing a bad
5925 conversion, convert_like will complain. */
5926 if (!can_convert_arg_bad (type, rhstype, rhs))
5928 /* When -Wno-pmf-conversions is use, we just silently allow
5929 conversions from pointers-to-members to plain pointers. If
5930 the conversion doesn't work, cp_convert will complain. */
5932 && TYPE_PTR_P (type)
5933 && TYPE_PTRMEMFUNC_P (rhstype))
5934 rhs = cp_convert (strip_top_quals (type), rhs);
5937 /* If the right-hand side has unknown type, then it is an
5938 overloaded function. Call instantiate_type to get error
5940 if (rhstype == unknown_type_node)
5941 instantiate_type (type, rhs, tf_error | tf_warning);
5943 error ("cannot convert %qT to %qT for argument %qP to %qD",
5944 rhstype, type, parmnum, fndecl);
5946 error ("cannot convert %qT to %qT in %s", rhstype, type, errtype);
5947 return error_mark_node;
5950 return perform_implicit_conversion (strip_top_quals (type), rhs);
5953 /* Convert RHS to be of type TYPE.
5954 If EXP is nonzero, it is the target of the initialization.
5955 ERRTYPE is a string to use in error messages.
5957 Two major differences between the behavior of
5958 `convert_for_assignment' and `convert_for_initialization'
5959 are that references are bashed in the former, while
5960 copied in the latter, and aggregates are assigned in
5961 the former (operator=) while initialized in the
5964 If using constructor make sure no conversion operator exists, if one does
5965 exist, an ambiguity exists.
5967 If flags doesn't include LOOKUP_COMPLAIN, don't complain about anything. */
5970 convert_for_initialization (tree exp, tree type, tree rhs, int flags,
5971 const char *errtype, tree fndecl, int parmnum)
5973 enum tree_code codel = TREE_CODE (type);
5975 enum tree_code coder;
5977 /* build_c_cast puts on a NOP_EXPR to make the result not an lvalue.
5978 Strip such NOP_EXPRs, since RHS is used in non-lvalue context. */
5979 if (TREE_CODE (rhs) == NOP_EXPR
5980 && TREE_TYPE (rhs) == TREE_TYPE (TREE_OPERAND (rhs, 0))
5981 && codel != REFERENCE_TYPE)
5982 rhs = TREE_OPERAND (rhs, 0);
5984 if (rhs == error_mark_node
5985 || (TREE_CODE (rhs) == TREE_LIST && TREE_VALUE (rhs) == error_mark_node))
5986 return error_mark_node;
5988 if ((TREE_CODE (TREE_TYPE (rhs)) == ARRAY_TYPE
5989 && TREE_CODE (type) != ARRAY_TYPE
5990 && (TREE_CODE (type) != REFERENCE_TYPE
5991 || TREE_CODE (TREE_TYPE (type)) != ARRAY_TYPE))
5992 || (TREE_CODE (TREE_TYPE (rhs)) == FUNCTION_TYPE
5993 && (TREE_CODE (type) != REFERENCE_TYPE
5994 || TREE_CODE (TREE_TYPE (type)) != FUNCTION_TYPE))
5995 || TREE_CODE (TREE_TYPE (rhs)) == METHOD_TYPE)
5996 rhs = decay_conversion (rhs);
5998 rhstype = TREE_TYPE (rhs);
5999 coder = TREE_CODE (rhstype);
6001 if (coder == ERROR_MARK)
6002 return error_mark_node;
6004 /* We accept references to incomplete types, so we can
6005 return here before checking if RHS is of complete type. */
6007 if (codel == REFERENCE_TYPE)
6009 /* This should eventually happen in convert_arguments. */
6010 int savew = 0, savee = 0;
6013 savew = warningcount, savee = errorcount;
6014 rhs = initialize_reference (type, rhs, /*decl=*/NULL_TREE,
6018 if (warningcount > savew)
6019 cp_warning_at ("in passing argument %P of %q+D", parmnum, fndecl);
6020 else if (errorcount > savee)
6021 cp_error_at ("in passing argument %P of %q+D", parmnum, fndecl);
6027 exp = require_complete_type (exp);
6028 if (exp == error_mark_node)
6029 return error_mark_node;
6031 rhstype = non_reference (rhstype);
6033 type = complete_type (type);
6035 if (IS_AGGR_TYPE (type))
6036 return ocp_convert (type, rhs, CONV_IMPLICIT|CONV_FORCE_TEMP, flags);
6038 return convert_for_assignment (type, rhs, errtype, fndecl, parmnum);
6041 /* If RETVAL is the address of, or a reference to, a local variable or
6042 temporary give an appropriate warning. */
6045 maybe_warn_about_returning_address_of_local (tree retval)
6047 tree valtype = TREE_TYPE (DECL_RESULT (current_function_decl));
6048 tree whats_returned = retval;
6052 if (TREE_CODE (whats_returned) == COMPOUND_EXPR)
6053 whats_returned = TREE_OPERAND (whats_returned, 1);
6054 else if (TREE_CODE (whats_returned) == CONVERT_EXPR
6055 || TREE_CODE (whats_returned) == NON_LVALUE_EXPR
6056 || TREE_CODE (whats_returned) == NOP_EXPR)
6057 whats_returned = TREE_OPERAND (whats_returned, 0);
6062 if (TREE_CODE (whats_returned) != ADDR_EXPR)
6064 whats_returned = TREE_OPERAND (whats_returned, 0);
6066 if (TREE_CODE (valtype) == REFERENCE_TYPE)
6068 if (TREE_CODE (whats_returned) == AGGR_INIT_EXPR
6069 || TREE_CODE (whats_returned) == TARGET_EXPR)
6071 warning ("returning reference to temporary");
6074 if (TREE_CODE (whats_returned) == VAR_DECL
6075 && DECL_NAME (whats_returned)
6076 && TEMP_NAME_P (DECL_NAME (whats_returned)))
6078 warning ("reference to non-lvalue returned");
6083 if (DECL_P (whats_returned)
6084 && DECL_NAME (whats_returned)
6085 && DECL_FUNCTION_SCOPE_P (whats_returned)
6086 && !(TREE_STATIC (whats_returned)
6087 || TREE_PUBLIC (whats_returned)))
6089 if (TREE_CODE (valtype) == REFERENCE_TYPE)
6090 cp_warning_at ("reference to local variable %qD returned",
6093 cp_warning_at ("address of local variable %qD returned",
6099 /* Check that returning RETVAL from the current function is valid.
6100 Return an expression explicitly showing all conversions required to
6101 change RETVAL into the function return type, and to assign it to
6102 the DECL_RESULT for the function. */
6105 check_return_expr (tree retval)
6108 /* The type actually returned by the function, after any
6111 int fn_returns_value_p;
6113 /* A `volatile' function is one that isn't supposed to return, ever.
6114 (This is a G++ extension, used to get better code for functions
6115 that call the `volatile' function.) */
6116 if (TREE_THIS_VOLATILE (current_function_decl))
6117 warning ("function declared %<noreturn%> has a %<return%> statement");
6119 /* Check for various simple errors. */
6120 if (DECL_DESTRUCTOR_P (current_function_decl))
6123 error ("returning a value from a destructor");
6126 else if (DECL_CONSTRUCTOR_P (current_function_decl))
6128 if (in_function_try_handler)
6129 /* If a return statement appears in a handler of the
6130 function-try-block of a constructor, the program is ill-formed. */
6131 error ("cannot return from a handler of a function-try-block of a constructor");
6133 /* You can't return a value from a constructor. */
6134 error ("returning a value from a constructor");
6138 if (processing_template_decl)
6140 current_function_returns_value = 1;
6144 /* When no explicit return-value is given in a function with a named
6145 return value, the named return value is used. */
6146 result = DECL_RESULT (current_function_decl);
6147 valtype = TREE_TYPE (result);
6148 gcc_assert (valtype != NULL_TREE);
6149 fn_returns_value_p = !VOID_TYPE_P (valtype);
6150 if (!retval && DECL_NAME (result) && fn_returns_value_p)
6153 /* Check for a return statement with no return value in a function
6154 that's supposed to return a value. */
6155 if (!retval && fn_returns_value_p)
6157 pedwarn ("return-statement with no value, in function returning %qT",
6159 /* Clear this, so finish_function won't say that we reach the
6160 end of a non-void function (which we don't, we gave a
6162 current_function_returns_null = 0;
6164 /* Check for a return statement with a value in a function that
6165 isn't supposed to return a value. */
6166 else if (retval && !fn_returns_value_p)
6168 if (VOID_TYPE_P (TREE_TYPE (retval)))
6169 /* You can return a `void' value from a function of `void'
6170 type. In that case, we have to evaluate the expression for
6171 its side-effects. */
6172 finish_expr_stmt (retval);
6174 pedwarn ("return-statement with a value, in function "
6175 "returning 'void'");
6177 current_function_returns_null = 1;
6179 /* There's really no value to return, after all. */
6183 /* Remember that this function can sometimes return without a
6185 current_function_returns_null = 1;
6187 /* Remember that this function did return a value. */
6188 current_function_returns_value = 1;
6190 /* Check for erroneous operands -- but after giving ourselves a
6191 chance to provide an error about returning a value from a void
6193 if (error_operand_p (retval))
6195 current_function_return_value = error_mark_node;
6196 return error_mark_node;
6199 /* Only operator new(...) throw(), can return NULL [expr.new/13]. */
6200 if ((DECL_OVERLOADED_OPERATOR_P (current_function_decl) == NEW_EXPR
6201 || DECL_OVERLOADED_OPERATOR_P (current_function_decl) == VEC_NEW_EXPR)
6202 && !TYPE_NOTHROW_P (TREE_TYPE (current_function_decl))
6204 && null_ptr_cst_p (retval))
6205 warning ("%<operator new%> must not return NULL unless it is "
6206 "declared %<throw()%> (or -fcheck-new is in effect)");
6208 /* Effective C++ rule 15. See also start_function. */
6210 && DECL_NAME (current_function_decl) == ansi_assopname(NOP_EXPR))
6214 /* The function return type must be a reference to the current
6216 if (TREE_CODE (valtype) == REFERENCE_TYPE
6217 && same_type_ignoring_top_level_qualifiers_p
6218 (TREE_TYPE (valtype), TREE_TYPE (current_class_ref)))
6220 /* Returning '*this' is obviously OK. */
6221 if (retval == current_class_ref)
6223 /* If we are calling a function whose return type is the same of
6224 the current class reference, it is ok. */
6225 else if (TREE_CODE (retval) == INDIRECT_REF
6226 && TREE_CODE (TREE_OPERAND (retval, 0)) == CALL_EXPR)
6231 warning ("%<operator=%> should return a reference to %<*this%>");
6234 /* The fabled Named Return Value optimization, as per [class.copy]/15:
6236 [...] For a function with a class return type, if the expression
6237 in the return statement is the name of a local object, and the cv-
6238 unqualified type of the local object is the same as the function
6239 return type, an implementation is permitted to omit creating the tem-
6240 porary object to hold the function return value [...]
6242 So, if this is a value-returning function that always returns the same
6243 local variable, remember it.
6245 It might be nice to be more flexible, and choose the first suitable
6246 variable even if the function sometimes returns something else, but
6247 then we run the risk of clobbering the variable we chose if the other
6248 returned expression uses the chosen variable somehow. And people expect
6249 this restriction, anyway. (jason 2000-11-19)
6251 See finish_function and finalize_nrv for the rest of this optimization. */
6253 if (fn_returns_value_p && flag_elide_constructors)
6255 if (retval != NULL_TREE
6256 && (current_function_return_value == NULL_TREE
6257 || current_function_return_value == retval)
6258 && TREE_CODE (retval) == VAR_DECL
6259 && DECL_CONTEXT (retval) == current_function_decl
6260 && ! TREE_STATIC (retval)
6261 && (DECL_ALIGN (retval)
6262 >= DECL_ALIGN (DECL_RESULT (current_function_decl)))
6263 && same_type_p ((TYPE_MAIN_VARIANT
6264 (TREE_TYPE (retval))),
6266 (TREE_TYPE (TREE_TYPE (current_function_decl))))))
6267 current_function_return_value = retval;
6269 current_function_return_value = error_mark_node;
6272 /* We don't need to do any conversions when there's nothing being
6277 /* Do any required conversions. */
6278 if (retval == result || DECL_CONSTRUCTOR_P (current_function_decl))
6279 /* No conversions are required. */
6283 /* The type the function is declared to return. */
6284 tree functype = TREE_TYPE (TREE_TYPE (current_function_decl));
6286 /* First convert the value to the function's return type, then
6287 to the type of return value's location to handle the
6288 case that functype is smaller than the valtype. */
6289 retval = convert_for_initialization
6290 (NULL_TREE, functype, retval, LOOKUP_NORMAL|LOOKUP_ONLYCONVERTING,
6291 "return", NULL_TREE, 0);
6292 retval = convert (valtype, retval);
6294 /* If the conversion failed, treat this just like `return;'. */
6295 if (retval == error_mark_node)
6297 /* We can't initialize a register from a AGGR_INIT_EXPR. */
6298 else if (! current_function_returns_struct
6299 && TREE_CODE (retval) == TARGET_EXPR
6300 && TREE_CODE (TREE_OPERAND (retval, 1)) == AGGR_INIT_EXPR)
6301 retval = build2 (COMPOUND_EXPR, TREE_TYPE (retval), retval,
6302 TREE_OPERAND (retval, 0));
6304 maybe_warn_about_returning_address_of_local (retval);
6307 /* Actually copy the value returned into the appropriate location. */
6308 if (retval && retval != result)
6309 retval = build2 (INIT_EXPR, TREE_TYPE (result), result, retval);
6315 /* Returns nonzero if the pointer-type FROM can be converted to the
6316 pointer-type TO via a qualification conversion. If CONSTP is -1,
6317 then we return nonzero if the pointers are similar, and the
6318 cv-qualification signature of FROM is a proper subset of that of TO.
6320 If CONSTP is positive, then all outer pointers have been
6324 comp_ptr_ttypes_real (tree to, tree from, int constp)
6326 bool to_more_cv_qualified = false;
6328 for (; ; to = TREE_TYPE (to), from = TREE_TYPE (from))
6330 if (TREE_CODE (to) != TREE_CODE (from))
6333 if (TREE_CODE (from) == OFFSET_TYPE
6334 && !same_type_p (TYPE_OFFSET_BASETYPE (from),
6335 TYPE_OFFSET_BASETYPE (to)))
6338 /* Const and volatile mean something different for function types,
6339 so the usual checks are not appropriate. */
6340 if (TREE_CODE (to) != FUNCTION_TYPE && TREE_CODE (to) != METHOD_TYPE)
6342 if (!at_least_as_qualified_p (to, from))
6345 if (!at_least_as_qualified_p (from, to))
6349 to_more_cv_qualified = true;
6353 constp &= TYPE_READONLY (to);
6356 if (TREE_CODE (to) != POINTER_TYPE && !TYPE_PTRMEM_P (to))
6357 return ((constp >= 0 || to_more_cv_qualified)
6358 && same_type_ignoring_top_level_qualifiers_p (to, from));
6362 /* When comparing, say, char ** to char const **, this function takes
6363 the 'char *' and 'char const *'. Do not pass non-pointer/reference
6364 types to this function. */
6367 comp_ptr_ttypes (tree to, tree from)
6369 return comp_ptr_ttypes_real (to, from, 1);
6372 /* Returns 1 if to and from are (possibly multi-level) pointers to the same
6373 type or inheritance-related types, regardless of cv-quals. */
6376 ptr_reasonably_similar (tree to, tree from)
6378 for (; ; to = TREE_TYPE (to), from = TREE_TYPE (from))
6380 /* Any target type is similar enough to void. */
6381 if (TREE_CODE (to) == VOID_TYPE
6382 || TREE_CODE (from) == VOID_TYPE)
6385 if (TREE_CODE (to) != TREE_CODE (from))
6388 if (TREE_CODE (from) == OFFSET_TYPE
6389 && comptypes (TYPE_OFFSET_BASETYPE (to),
6390 TYPE_OFFSET_BASETYPE (from),
6391 COMPARE_BASE | COMPARE_DERIVED))
6394 if (TREE_CODE (to) == VECTOR_TYPE
6395 && vector_types_convertible_p (to, from))
6398 if (TREE_CODE (to) == INTEGER_TYPE
6399 && TYPE_PRECISION (to) == TYPE_PRECISION (from))
6402 if (TREE_CODE (to) == FUNCTION_TYPE)
6405 if (TREE_CODE (to) != POINTER_TYPE)
6407 (TYPE_MAIN_VARIANT (to), TYPE_MAIN_VARIANT (from),
6408 COMPARE_BASE | COMPARE_DERIVED);
6412 /* Like comp_ptr_ttypes, for const_cast. */
6415 comp_ptr_ttypes_const (tree to, tree from)
6417 for (; ; to = TREE_TYPE (to), from = TREE_TYPE (from))
6419 if (TREE_CODE (to) != TREE_CODE (from))
6422 if (TREE_CODE (from) == OFFSET_TYPE
6423 && same_type_p (TYPE_OFFSET_BASETYPE (from),
6424 TYPE_OFFSET_BASETYPE (to)))
6427 if (TREE_CODE (to) != POINTER_TYPE)
6428 return same_type_ignoring_top_level_qualifiers_p (to, from);
6432 /* Returns the type qualifiers for this type, including the qualifiers on the
6433 elements for an array type. */
6436 cp_type_quals (tree type)
6438 type = strip_array_types (type);
6439 if (type == error_mark_node)
6440 return TYPE_UNQUALIFIED;
6441 return TYPE_QUALS (type);
6444 /* Returns nonzero if the TYPE contains a mutable member. */
6447 cp_has_mutable_p (tree type)
6449 type = strip_array_types (type);
6451 return CLASS_TYPE_P (type) && CLASSTYPE_HAS_MUTABLE (type);
6454 /* Subroutine of casts_away_constness. Make T1 and T2 point at
6455 exemplar types such that casting T1 to T2 is casting away constness
6456 if and only if there is no implicit conversion from T1 to T2. */
6459 casts_away_constness_r (tree *t1, tree *t2)
6464 /* [expr.const.cast]
6466 For multi-level pointer to members and multi-level mixed pointers
6467 and pointers to members (conv.qual), the "member" aspect of a
6468 pointer to member level is ignored when determining if a const
6469 cv-qualifier has been cast away. */
6470 if (TYPE_PTRMEM_P (*t1))
6471 *t1 = build_pointer_type (TYPE_PTRMEM_POINTED_TO_TYPE (*t1));
6472 if (TYPE_PTRMEM_P (*t2))
6473 *t2 = build_pointer_type (TYPE_PTRMEM_POINTED_TO_TYPE (*t2));
6475 /* [expr.const.cast]
6477 For two pointer types:
6479 X1 is T1cv1,1 * ... cv1,N * where T1 is not a pointer type
6480 X2 is T2cv2,1 * ... cv2,M * where T2 is not a pointer type
6483 casting from X1 to X2 casts away constness if, for a non-pointer
6484 type T there does not exist an implicit conversion (clause
6487 Tcv1,(N-K+1) * cv1,(N-K+2) * ... cv1,N *
6491 Tcv2,(M-K+1) * cv2,(M-K+2) * ... cv2,M *. */
6493 if (TREE_CODE (*t1) != POINTER_TYPE
6494 || TREE_CODE (*t2) != POINTER_TYPE)
6496 *t1 = cp_build_qualified_type (void_type_node,
6497 cp_type_quals (*t1));
6498 *t2 = cp_build_qualified_type (void_type_node,
6499 cp_type_quals (*t2));
6503 quals1 = cp_type_quals (*t1);
6504 quals2 = cp_type_quals (*t2);
6505 *t1 = TREE_TYPE (*t1);
6506 *t2 = TREE_TYPE (*t2);
6507 casts_away_constness_r (t1, t2);
6508 *t1 = build_pointer_type (*t1);
6509 *t2 = build_pointer_type (*t2);
6510 *t1 = cp_build_qualified_type (*t1, quals1);
6511 *t2 = cp_build_qualified_type (*t2, quals2);
6514 /* Returns nonzero if casting from TYPE1 to TYPE2 casts away
6518 casts_away_constness (tree t1, tree t2)
6520 if (TREE_CODE (t2) == REFERENCE_TYPE)
6522 /* [expr.const.cast]
6524 Casting from an lvalue of type T1 to an lvalue of type T2
6525 using a reference cast casts away constness if a cast from an
6526 rvalue of type "pointer to T1" to the type "pointer to T2"
6527 casts away constness. */
6528 t1 = (TREE_CODE (t1) == REFERENCE_TYPE ? TREE_TYPE (t1) : t1);
6529 return casts_away_constness (build_pointer_type (t1),
6530 build_pointer_type (TREE_TYPE (t2)));
6533 if (TYPE_PTRMEM_P (t1) && TYPE_PTRMEM_P (t2))
6534 /* [expr.const.cast]
6536 Casting from an rvalue of type "pointer to data member of X
6537 of type T1" to the type "pointer to data member of Y of type
6538 T2" casts away constness if a cast from an rvalue of type
6539 "pointer to T1" to the type "pointer to T2" casts away
6541 return casts_away_constness
6542 (build_pointer_type (TYPE_PTRMEM_POINTED_TO_TYPE (t1)),
6543 build_pointer_type (TYPE_PTRMEM_POINTED_TO_TYPE (t2)));
6545 /* Casting away constness is only something that makes sense for
6546 pointer or reference types. */
6547 if (TREE_CODE (t1) != POINTER_TYPE
6548 || TREE_CODE (t2) != POINTER_TYPE)
6551 /* Top-level qualifiers don't matter. */
6552 t1 = TYPE_MAIN_VARIANT (t1);
6553 t2 = TYPE_MAIN_VARIANT (t2);
6554 casts_away_constness_r (&t1, &t2);
6555 if (!can_convert (t2, t1))
6561 /* If T is a REFERENCE_TYPE return the type to which T refers.
6562 Otherwise, return T itself. */
6565 non_reference (tree t)
6567 if (TREE_CODE (t) == REFERENCE_TYPE)