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 (code == REFERENCE_TYPE)
1348 exp = convert_from_reference (exp);
1349 type = TREE_TYPE (exp);
1350 code = TREE_CODE (type);
1353 if (type == error_mark_node)
1354 return error_mark_node;
1356 if (type_unknown_p (exp))
1358 cxx_incomplete_type_error (exp, TREE_TYPE (exp));
1359 return error_mark_node;
1362 /* Constants can be used directly unless they're not loadable. */
1363 if (TREE_CODE (exp) == CONST_DECL)
1364 exp = DECL_INITIAL (exp);
1365 /* Replace a nonvolatile const static variable with its value. We
1366 don't do this for arrays, though; we want the address of the
1367 first element of the array, not the address of the first element
1368 of its initializing constant. */
1369 else if (code != ARRAY_TYPE)
1371 exp = decl_constant_value (exp);
1372 type = TREE_TYPE (exp);
1375 /* build_c_cast puts on a NOP_EXPR to make the result not an lvalue.
1376 Leave such NOP_EXPRs, since RHS is being used in non-lvalue context. */
1378 if (code == VOID_TYPE)
1380 error ("void value not ignored as it ought to be");
1381 return error_mark_node;
1383 if (invalid_nonstatic_memfn_p (exp))
1384 return error_mark_node;
1385 if (code == FUNCTION_TYPE || is_overloaded_fn (exp))
1386 return build_unary_op (ADDR_EXPR, exp, 0);
1387 if (code == ARRAY_TYPE)
1392 if (TREE_CODE (exp) == INDIRECT_REF)
1393 return build_nop (build_pointer_type (TREE_TYPE (type)),
1394 TREE_OPERAND (exp, 0));
1396 if (TREE_CODE (exp) == COMPOUND_EXPR)
1398 tree op1 = decay_conversion (TREE_OPERAND (exp, 1));
1399 return build2 (COMPOUND_EXPR, TREE_TYPE (op1),
1400 TREE_OPERAND (exp, 0), op1);
1404 && ! (TREE_CODE (exp) == CONSTRUCTOR && TREE_STATIC (exp)))
1406 error ("invalid use of non-lvalue array");
1407 return error_mark_node;
1410 ptrtype = build_pointer_type (TREE_TYPE (type));
1412 if (TREE_CODE (exp) == VAR_DECL)
1414 if (!cxx_mark_addressable (exp))
1415 return error_mark_node;
1416 adr = build_nop (ptrtype, build_address (exp));
1419 /* This way is better for a COMPONENT_REF since it can
1420 simplify the offset for a component. */
1421 adr = build_unary_op (ADDR_EXPR, exp, 1);
1422 return cp_convert (ptrtype, adr);
1425 /* [basic.lval]: Class rvalues can have cv-qualified types; non-class
1426 rvalues always have cv-unqualified types. */
1427 if (! CLASS_TYPE_P (type))
1428 exp = cp_convert (TYPE_MAIN_VARIANT (type), exp);
1434 default_conversion (tree exp)
1436 exp = decay_conversion (exp);
1438 if (INTEGRAL_OR_ENUMERATION_TYPE_P (TREE_TYPE (exp)))
1439 exp = perform_integral_promotions (exp);
1444 /* EXPR is an expression with an integral or enumeration type.
1445 Perform the integral promotions in [conv.prom], and return the
1449 perform_integral_promotions (tree expr)
1454 type = TREE_TYPE (expr);
1455 gcc_assert (INTEGRAL_OR_ENUMERATION_TYPE_P (type));
1456 promoted_type = type_promotes_to (type);
1457 if (type != promoted_type)
1458 expr = cp_convert (promoted_type, expr);
1462 /* Take the address of an inline function without setting TREE_ADDRESSABLE
1466 inline_conversion (tree exp)
1468 if (TREE_CODE (exp) == FUNCTION_DECL)
1469 exp = build1 (ADDR_EXPR, build_pointer_type (TREE_TYPE (exp)), exp);
1474 /* Returns nonzero iff exp is a STRING_CST or the result of applying
1475 decay_conversion to one. */
1478 string_conv_p (tree totype, tree exp, int warn)
1482 if (! flag_const_strings || TREE_CODE (totype) != POINTER_TYPE)
1485 t = TREE_TYPE (totype);
1486 if (!same_type_p (t, char_type_node)
1487 && !same_type_p (t, wchar_type_node))
1490 if (TREE_CODE (exp) == STRING_CST)
1492 /* Make sure that we don't try to convert between char and wchar_t. */
1493 if (!same_type_p (TYPE_MAIN_VARIANT (TREE_TYPE (TREE_TYPE (exp))), t))
1498 /* Is this a string constant which has decayed to 'const char *'? */
1499 t = build_pointer_type (build_qualified_type (t, TYPE_QUAL_CONST));
1500 if (!same_type_p (TREE_TYPE (exp), t))
1503 if (TREE_CODE (exp) != ADDR_EXPR
1504 || TREE_CODE (TREE_OPERAND (exp, 0)) != STRING_CST)
1508 /* This warning is not very useful, as it complains about printf. */
1509 if (warn && warn_write_strings)
1510 warning ("deprecated conversion from string constant to %qT'", totype);
1515 /* Given a COND_EXPR, MIN_EXPR, or MAX_EXPR in T, return it in a form that we
1516 can, for example, use as an lvalue. This code used to be in
1517 unary_complex_lvalue, but we needed it to deal with `a = (d == c) ? b : c'
1518 expressions, where we're dealing with aggregates. But now it's again only
1519 called from unary_complex_lvalue. The case (in particular) that led to
1520 this was with CODE == ADDR_EXPR, since it's not an lvalue when we'd
1524 rationalize_conditional_expr (enum tree_code code, tree t)
1526 /* For MIN_EXPR or MAX_EXPR, fold-const.c has arranged things so that
1527 the first operand is always the one to be used if both operands
1528 are equal, so we know what conditional expression this used to be. */
1529 if (TREE_CODE (t) == MIN_EXPR || TREE_CODE (t) == MAX_EXPR)
1531 /* The following code is incorrect if either operand side-effects. */
1532 gcc_assert (!TREE_SIDE_EFFECTS (TREE_OPERAND (t, 0))
1533 && !TREE_SIDE_EFFECTS (TREE_OPERAND (t, 1)));
1535 build_conditional_expr (build_x_binary_op ((TREE_CODE (t) == MIN_EXPR
1536 ? LE_EXPR : GE_EXPR),
1537 TREE_OPERAND (t, 0),
1538 TREE_OPERAND (t, 1),
1539 /*overloaded_p=*/NULL),
1540 build_unary_op (code, TREE_OPERAND (t, 0), 0),
1541 build_unary_op (code, TREE_OPERAND (t, 1), 0));
1545 build_conditional_expr (TREE_OPERAND (t, 0),
1546 build_unary_op (code, TREE_OPERAND (t, 1), 0),
1547 build_unary_op (code, TREE_OPERAND (t, 2), 0));
1550 /* Given the TYPE of an anonymous union field inside T, return the
1551 FIELD_DECL for the field. If not found return NULL_TREE. Because
1552 anonymous unions can nest, we must also search all anonymous unions
1553 that are directly reachable. */
1556 lookup_anon_field (tree t, tree type)
1560 for (field = TYPE_FIELDS (t); field; field = TREE_CHAIN (field))
1562 if (TREE_STATIC (field))
1564 if (TREE_CODE (field) != FIELD_DECL || DECL_ARTIFICIAL (field))
1567 /* If we find it directly, return the field. */
1568 if (DECL_NAME (field) == NULL_TREE
1569 && type == TYPE_MAIN_VARIANT (TREE_TYPE (field)))
1574 /* Otherwise, it could be nested, search harder. */
1575 if (DECL_NAME (field) == NULL_TREE
1576 && ANON_AGGR_TYPE_P (TREE_TYPE (field)))
1578 tree subfield = lookup_anon_field (TREE_TYPE (field), type);
1586 /* Build an expression representing OBJECT.MEMBER. OBJECT is an
1587 expression; MEMBER is a DECL or baselink. If ACCESS_PATH is
1588 non-NULL, it indicates the path to the base used to name MEMBER.
1589 If PRESERVE_REFERENCE is true, the expression returned will have
1590 REFERENCE_TYPE if the MEMBER does. Otherwise, the expression
1591 returned will have the type referred to by the reference.
1593 This function does not perform access control; that is either done
1594 earlier by the parser when the name of MEMBER is resolved to MEMBER
1595 itself, or later when overload resolution selects one of the
1596 functions indicated by MEMBER. */
1599 build_class_member_access_expr (tree object, tree member,
1600 tree access_path, bool preserve_reference)
1604 tree result = NULL_TREE;
1606 if (object == error_mark_node || member == error_mark_node)
1607 return error_mark_node;
1609 if (TREE_CODE (member) == PSEUDO_DTOR_EXPR)
1612 gcc_assert (DECL_P (member) || BASELINK_P (member));
1616 The type of the first expression shall be "class object" (of a
1618 object_type = TREE_TYPE (object);
1619 if (!currently_open_class (object_type)
1620 && !complete_type_or_else (object_type, object))
1621 return error_mark_node;
1622 if (!CLASS_TYPE_P (object_type))
1624 error ("request for member %qD in %qE, which is of non-class type %qT",
1625 member, object, object_type);
1626 return error_mark_node;
1629 /* The standard does not seem to actually say that MEMBER must be a
1630 member of OBJECT_TYPE. However, that is clearly what is
1632 if (DECL_P (member))
1634 member_scope = DECL_CLASS_CONTEXT (member);
1636 if (TREE_DEPRECATED (member))
1637 warn_deprecated_use (member);
1640 member_scope = BINFO_TYPE (BASELINK_BINFO (member));
1641 /* If MEMBER is from an anonymous aggregate, MEMBER_SCOPE will
1642 presently be the anonymous union. Go outwards until we find a
1643 type related to OBJECT_TYPE. */
1644 while (ANON_AGGR_TYPE_P (member_scope)
1645 && !same_type_ignoring_top_level_qualifiers_p (member_scope,
1647 member_scope = TYPE_CONTEXT (member_scope);
1648 if (!member_scope || !DERIVED_FROM_P (member_scope, object_type))
1650 if (TREE_CODE (member) == FIELD_DECL)
1651 error ("invalid use of nonstatic data member %qE", member);
1653 error ("%qD is not a member of %qT", member, object_type);
1654 return error_mark_node;
1657 /* Transform `(a, b).x' into `(*(a, &b)).x', `(a ? b : c).x' into
1658 `(*(a ? &b : &c)).x', and so on. A COND_EXPR is only an lvalue
1659 in the frontend; only _DECLs and _REFs are lvalues in the backend. */
1661 tree temp = unary_complex_lvalue (ADDR_EXPR, object);
1663 object = build_indirect_ref (temp, NULL);
1666 /* In [expr.ref], there is an explicit list of the valid choices for
1667 MEMBER. We check for each of those cases here. */
1668 if (TREE_CODE (member) == VAR_DECL)
1670 /* A static data member. */
1672 /* If OBJECT has side-effects, they are supposed to occur. */
1673 if (TREE_SIDE_EFFECTS (object))
1674 result = build2 (COMPOUND_EXPR, TREE_TYPE (result), object, result);
1676 else if (TREE_CODE (member) == FIELD_DECL)
1678 /* A non-static data member. */
1683 null_object_p = (TREE_CODE (object) == INDIRECT_REF
1684 && integer_zerop (TREE_OPERAND (object, 0)));
1686 /* Convert OBJECT to the type of MEMBER. */
1687 if (!same_type_p (TYPE_MAIN_VARIANT (object_type),
1688 TYPE_MAIN_VARIANT (member_scope)))
1693 binfo = lookup_base (access_path ? access_path : object_type,
1694 member_scope, ba_unique, &kind);
1695 if (binfo == error_mark_node)
1696 return error_mark_node;
1698 /* It is invalid to try to get to a virtual base of a
1699 NULL object. The most common cause is invalid use of
1701 if (null_object_p && kind == bk_via_virtual)
1703 error ("invalid access to non-static data member %qD of "
1706 error ("(perhaps the %<offsetof%> macro was used incorrectly)");
1707 return error_mark_node;
1710 /* Convert to the base. */
1711 object = build_base_path (PLUS_EXPR, object, binfo,
1713 /* If we found the base successfully then we should be able
1714 to convert to it successfully. */
1715 gcc_assert (object != error_mark_node);
1718 /* Complain about other invalid uses of offsetof, even though they will
1719 give the right answer. Note that we complain whether or not they
1720 actually used the offsetof macro, since there's no way to know at this
1721 point. So we just give a warning, instead of a pedwarn. */
1722 /* Do not produce this warning for base class field references, because
1723 we know for a fact that didn't come from offsetof. This does occur
1724 in various testsuite cases where a null object is passed where a
1725 vtable access is required. */
1726 if (null_object_p && warn_invalid_offsetof
1727 && CLASSTYPE_NON_POD_P (object_type)
1728 && !DECL_FIELD_IS_BASE (member)
1729 && !skip_evaluation)
1731 warning ("invalid access to non-static data member %qD of NULL object",
1733 warning ("(perhaps the %<offsetof%> macro was used incorrectly)");
1736 /* If MEMBER is from an anonymous aggregate, we have converted
1737 OBJECT so that it refers to the class containing the
1738 anonymous union. Generate a reference to the anonymous union
1739 itself, and recur to find MEMBER. */
1740 if (ANON_AGGR_TYPE_P (DECL_CONTEXT (member))
1741 /* When this code is called from build_field_call, the
1742 object already has the type of the anonymous union.
1743 That is because the COMPONENT_REF was already
1744 constructed, and was then disassembled before calling
1745 build_field_call. After the function-call code is
1746 cleaned up, this waste can be eliminated. */
1747 && (!same_type_ignoring_top_level_qualifiers_p
1748 (TREE_TYPE (object), DECL_CONTEXT (member))))
1750 tree anonymous_union;
1752 anonymous_union = lookup_anon_field (TREE_TYPE (object),
1753 DECL_CONTEXT (member));
1754 object = build_class_member_access_expr (object,
1756 /*access_path=*/NULL_TREE,
1757 preserve_reference);
1760 /* Compute the type of the field, as described in [expr.ref]. */
1761 type_quals = TYPE_UNQUALIFIED;
1762 member_type = TREE_TYPE (member);
1763 if (TREE_CODE (member_type) != REFERENCE_TYPE)
1765 type_quals = (cp_type_quals (member_type)
1766 | cp_type_quals (object_type));
1768 /* A field is const (volatile) if the enclosing object, or the
1769 field itself, is const (volatile). But, a mutable field is
1770 not const, even within a const object. */
1771 if (DECL_MUTABLE_P (member))
1772 type_quals &= ~TYPE_QUAL_CONST;
1773 member_type = cp_build_qualified_type (member_type, type_quals);
1776 result = build3 (COMPONENT_REF, member_type, object, member,
1778 result = fold_if_not_in_template (result);
1780 /* Mark the expression const or volatile, as appropriate. Even
1781 though we've dealt with the type above, we still have to mark the
1782 expression itself. */
1783 if (type_quals & TYPE_QUAL_CONST)
1784 TREE_READONLY (result) = 1;
1785 else if (type_quals & TYPE_QUAL_VOLATILE)
1786 TREE_THIS_VOLATILE (result) = 1;
1788 else if (BASELINK_P (member))
1790 /* The member is a (possibly overloaded) member function. */
1794 /* If the MEMBER is exactly one static member function, then we
1795 know the type of the expression. Otherwise, we must wait
1796 until overload resolution has been performed. */
1797 functions = BASELINK_FUNCTIONS (member);
1798 if (TREE_CODE (functions) == FUNCTION_DECL
1799 && DECL_STATIC_FUNCTION_P (functions))
1800 type = TREE_TYPE (functions);
1802 type = unknown_type_node;
1803 /* Note that we do not convert OBJECT to the BASELINK_BINFO
1804 base. That will happen when the function is called. */
1805 result = build3 (COMPONENT_REF, type, object, member, NULL_TREE);
1807 else if (TREE_CODE (member) == CONST_DECL)
1809 /* The member is an enumerator. */
1811 /* If OBJECT has side-effects, they are supposed to occur. */
1812 if (TREE_SIDE_EFFECTS (object))
1813 result = build2 (COMPOUND_EXPR, TREE_TYPE (result),
1818 error ("invalid use of %qD", member);
1819 return error_mark_node;
1822 if (!preserve_reference)
1825 If E2 is declared to have type "reference to T", then ... the
1826 type of E1.E2 is T. */
1827 result = convert_from_reference (result);
1832 /* Return the destructor denoted by OBJECT.SCOPE::~DTOR_NAME, or, if
1833 SCOPE is NULL, by OBJECT.~DTOR_NAME. */
1836 lookup_destructor (tree object, tree scope, tree dtor_name)
1838 tree object_type = TREE_TYPE (object);
1839 tree dtor_type = TREE_OPERAND (dtor_name, 0);
1842 if (scope && !check_dtor_name (scope, dtor_name))
1844 error ("qualified type %qT does not match destructor name ~%qT",
1846 return error_mark_node;
1848 if (!DERIVED_FROM_P (dtor_type, TYPE_MAIN_VARIANT (object_type)))
1850 error ("the type being destroyed is %qT, but the destructor refers to %qT",
1851 TYPE_MAIN_VARIANT (object_type), dtor_type);
1852 return error_mark_node;
1854 if (!TYPE_HAS_DESTRUCTOR (dtor_type))
1855 return build3 (PSEUDO_DTOR_EXPR, void_type_node, object, scope,
1857 expr = lookup_member (dtor_type, complete_dtor_identifier,
1858 /*protect=*/1, /*want_type=*/false);
1859 expr = (adjust_result_of_qualified_name_lookup
1860 (expr, dtor_type, object_type));
1864 /* This function is called by the parser to process a class member
1865 access expression of the form OBJECT.NAME. NAME is a node used by
1866 the parser to represent a name; it is not yet a DECL. It may,
1867 however, be a BASELINK where the BASELINK_FUNCTIONS is a
1868 TEMPLATE_ID_EXPR. Templates must be looked up by the parser, and
1869 there is no reason to do the lookup twice, so the parser keeps the
1873 finish_class_member_access_expr (tree object, tree name)
1878 tree access_path = NULL_TREE;
1879 tree orig_object = object;
1880 tree orig_name = name;
1882 if (object == error_mark_node || name == error_mark_node)
1883 return error_mark_node;
1885 object_type = TREE_TYPE (object);
1887 if (processing_template_decl)
1889 if (/* If OBJECT_TYPE is dependent, so is OBJECT.NAME. */
1890 dependent_type_p (object_type)
1891 /* If NAME is just an IDENTIFIER_NODE, then the expression
1893 || TREE_CODE (object) == IDENTIFIER_NODE
1894 /* If NAME is "f<args>", where either 'f' or 'args' is
1895 dependent, then the expression is dependent. */
1896 || (TREE_CODE (name) == TEMPLATE_ID_EXPR
1897 && dependent_template_id_p (TREE_OPERAND (name, 0),
1898 TREE_OPERAND (name, 1)))
1899 /* If NAME is "T::X" where "T" is dependent, then the
1900 expression is dependent. */
1901 || (TREE_CODE (name) == SCOPE_REF
1902 && TYPE_P (TREE_OPERAND (name, 0))
1903 && dependent_type_p (TREE_OPERAND (name, 0))))
1904 return build_min_nt (COMPONENT_REF, object, name, NULL_TREE);
1905 object = build_non_dependent_expr (object);
1908 if (TREE_CODE (object_type) == REFERENCE_TYPE)
1910 object = convert_from_reference (object);
1911 object_type = TREE_TYPE (object);
1916 The type of the first expression shall be "class object" (of a
1918 if (!currently_open_class (object_type)
1919 && !complete_type_or_else (object_type, object))
1920 return error_mark_node;
1921 if (!CLASS_TYPE_P (object_type))
1923 error ("request for member %qD in %qE, which is of non-class type %qT",
1924 name, object, object_type);
1925 return error_mark_node;
1928 if (BASELINK_P (name))
1930 /* A member function that has already been looked up. */
1931 gcc_assert (TREE_CODE (BASELINK_FUNCTIONS (name)) == TEMPLATE_ID_EXPR);
1936 bool is_template_id = false;
1937 tree template_args = NULL_TREE;
1940 if (TREE_CODE (name) == TEMPLATE_ID_EXPR)
1942 is_template_id = true;
1943 template_args = TREE_OPERAND (name, 1);
1944 name = TREE_OPERAND (name, 0);
1946 if (TREE_CODE (name) == OVERLOAD)
1947 name = DECL_NAME (get_first_fn (name));
1948 else if (DECL_P (name))
1949 name = DECL_NAME (name);
1952 if (TREE_CODE (name) == SCOPE_REF)
1954 /* A qualified name. The qualifying class or namespace `S' has
1955 already been looked up; it is either a TYPE or a
1956 NAMESPACE_DECL. The member name is either an IDENTIFIER_NODE
1957 or a BIT_NOT_EXPR. */
1958 scope = TREE_OPERAND (name, 0);
1959 name = TREE_OPERAND (name, 1);
1960 gcc_assert (CLASS_TYPE_P (scope)
1961 || TREE_CODE (scope) == NAMESPACE_DECL);
1962 gcc_assert (TREE_CODE (name) == IDENTIFIER_NODE
1963 || TREE_CODE (name) == BIT_NOT_EXPR);
1965 /* If SCOPE is a namespace, then the qualified name does not
1966 name a member of OBJECT_TYPE. */
1967 if (TREE_CODE (scope) == NAMESPACE_DECL)
1969 error ("%<%D::%D%> is not a member of %qT",
1970 scope, name, object_type);
1971 return error_mark_node;
1974 /* Find the base of OBJECT_TYPE corresponding to SCOPE. */
1975 access_path = lookup_base (object_type, scope, ba_check, NULL);
1976 if (access_path == error_mark_node)
1977 return error_mark_node;
1980 error ("%qT is not a base of %qT", scope, object_type);
1981 return error_mark_node;
1987 access_path = object_type;
1990 if (TREE_CODE (name) == BIT_NOT_EXPR)
1991 member = lookup_destructor (object, scope, name);
1994 /* Look up the member. */
1995 member = lookup_member (access_path, name, /*protect=*/1,
1996 /*want_type=*/false);
1997 if (member == NULL_TREE)
1999 error ("%qD has no member named %qE", object_type, name);
2000 return error_mark_node;
2002 if (member == error_mark_node)
2003 return error_mark_node;
2008 tree template = member;
2010 if (BASELINK_P (template))
2011 template = lookup_template_function (template, template_args);
2014 error ("%qD is not a member template function", name);
2015 return error_mark_node;
2020 if (TREE_DEPRECATED (member))
2021 warn_deprecated_use (member);
2023 expr = build_class_member_access_expr (object, member, access_path,
2024 /*preserve_reference=*/false);
2025 if (processing_template_decl && expr != error_mark_node)
2026 return build_min_non_dep (COMPONENT_REF, expr,
2027 orig_object, orig_name, NULL_TREE);
2031 /* Return an expression for the MEMBER_NAME field in the internal
2032 representation of PTRMEM, a pointer-to-member function. (Each
2033 pointer-to-member function type gets its own RECORD_TYPE so it is
2034 more convenient to access the fields by name than by FIELD_DECL.)
2035 This routine converts the NAME to a FIELD_DECL and then creates the
2036 node for the complete expression. */
2039 build_ptrmemfunc_access_expr (tree ptrmem, tree member_name)
2045 /* This code is a stripped down version of
2046 build_class_member_access_expr. It does not work to use that
2047 routine directly because it expects the object to be of class
2049 ptrmem_type = TREE_TYPE (ptrmem);
2050 gcc_assert (TYPE_PTRMEMFUNC_P (ptrmem_type));
2051 member = lookup_member (ptrmem_type, member_name, /*protect=*/0,
2052 /*want_type=*/false);
2053 member_type = cp_build_qualified_type (TREE_TYPE (member),
2054 cp_type_quals (ptrmem_type));
2055 return fold (build3 (COMPONENT_REF, member_type,
2056 ptrmem, member, NULL_TREE));
2059 /* Given an expression PTR for a pointer, return an expression
2060 for the value pointed to.
2061 ERRORSTRING is the name of the operator to appear in error messages.
2063 This function may need to overload OPERATOR_FNNAME.
2064 Must also handle REFERENCE_TYPEs for C++. */
2067 build_x_indirect_ref (tree expr, const char *errorstring)
2069 tree orig_expr = expr;
2072 if (processing_template_decl)
2074 if (type_dependent_expression_p (expr))
2075 return build_min_nt (INDIRECT_REF, expr);
2076 expr = build_non_dependent_expr (expr);
2079 rval = build_new_op (INDIRECT_REF, LOOKUP_NORMAL, expr, NULL_TREE,
2080 NULL_TREE, /*overloaded_p=*/NULL);
2082 rval = build_indirect_ref (expr, errorstring);
2084 if (processing_template_decl && rval != error_mark_node)
2085 return build_min_non_dep (INDIRECT_REF, rval, orig_expr);
2091 build_indirect_ref (tree ptr, const char *errorstring)
2095 if (ptr == error_mark_node)
2096 return error_mark_node;
2098 if (ptr == current_class_ptr)
2099 return current_class_ref;
2101 pointer = (TREE_CODE (TREE_TYPE (ptr)) == REFERENCE_TYPE
2102 ? ptr : decay_conversion (ptr));
2103 type = TREE_TYPE (pointer);
2105 if (TYPE_PTR_P (type) || TREE_CODE (type) == REFERENCE_TYPE)
2109 If the type of the expression is "pointer to T," the type
2110 of the result is "T."
2112 We must use the canonical variant because certain parts of
2113 the back end, like fold, do pointer comparisons between
2115 tree t = canonical_type_variant (TREE_TYPE (type));
2117 if (VOID_TYPE_P (t))
2119 /* A pointer to incomplete type (other than cv void) can be
2120 dereferenced [expr.unary.op]/1 */
2121 error ("%qT is not a pointer-to-object type", type);
2122 return error_mark_node;
2124 else if (TREE_CODE (pointer) == ADDR_EXPR
2125 && same_type_p (t, TREE_TYPE (TREE_OPERAND (pointer, 0))))
2126 /* The POINTER was something like `&x'. We simplify `*&x' to
2128 return TREE_OPERAND (pointer, 0);
2131 tree ref = build1 (INDIRECT_REF, t, pointer);
2133 /* We *must* set TREE_READONLY when dereferencing a pointer to const,
2134 so that we get the proper error message if the result is used
2135 to assign to. Also, &* is supposed to be a no-op. */
2136 TREE_READONLY (ref) = CP_TYPE_CONST_P (t);
2137 TREE_THIS_VOLATILE (ref) = CP_TYPE_VOLATILE_P (t);
2138 TREE_SIDE_EFFECTS (ref)
2139 = (TREE_THIS_VOLATILE (ref) || TREE_SIDE_EFFECTS (pointer));
2143 /* `pointer' won't be an error_mark_node if we were given a
2144 pointer to member, so it's cool to check for this here. */
2145 else if (TYPE_PTR_TO_MEMBER_P (type))
2146 error ("invalid use of %qs on pointer to member", errorstring);
2147 else if (pointer != error_mark_node)
2150 error ("invalid type argument of %qs", errorstring);
2152 error ("invalid type argument");
2154 return error_mark_node;
2157 /* This handles expressions of the form "a[i]", which denotes
2160 This is logically equivalent in C to *(a+i), but we may do it differently.
2161 If A is a variable or a member, we generate a primitive ARRAY_REF.
2162 This avoids forcing the array out of registers, and can work on
2163 arrays that are not lvalues (for example, members of structures returned
2166 If INDEX is of some user-defined type, it must be converted to
2167 integer type. Otherwise, to make a compatible PLUS_EXPR, it
2168 will inherit the type of the array, which will be some pointer type. */
2171 build_array_ref (tree array, tree idx)
2175 error ("subscript missing in array reference");
2176 return error_mark_node;
2179 if (TREE_TYPE (array) == error_mark_node
2180 || TREE_TYPE (idx) == error_mark_node)
2181 return error_mark_node;
2183 /* If ARRAY is a COMPOUND_EXPR or COND_EXPR, move our reference
2185 switch (TREE_CODE (array))
2189 tree value = build_array_ref (TREE_OPERAND (array, 1), idx);
2190 return build2 (COMPOUND_EXPR, TREE_TYPE (value),
2191 TREE_OPERAND (array, 0), value);
2195 return build_conditional_expr
2196 (TREE_OPERAND (array, 0),
2197 build_array_ref (TREE_OPERAND (array, 1), idx),
2198 build_array_ref (TREE_OPERAND (array, 2), idx));
2204 if (TREE_CODE (TREE_TYPE (array)) == ARRAY_TYPE)
2208 /* Subscripting with type char is likely to lose
2209 on a machine where chars are signed.
2210 So warn on any machine, but optionally.
2211 Don't warn for unsigned char since that type is safe.
2212 Don't warn for signed char because anyone who uses that
2213 must have done so deliberately. */
2214 if (warn_char_subscripts
2215 && TYPE_MAIN_VARIANT (TREE_TYPE (idx)) == char_type_node)
2216 warning ("array subscript has type %<char%>");
2218 if (!INTEGRAL_OR_ENUMERATION_TYPE_P (TREE_TYPE (idx)))
2220 error ("array subscript is not an integer");
2221 return error_mark_node;
2224 /* Apply integral promotions *after* noticing character types.
2225 (It is unclear why we do these promotions -- the standard
2226 does not say that we should. In fact, the natual thing would
2227 seem to be to convert IDX to ptrdiff_t; we're performing
2228 pointer arithmetic.) */
2229 idx = perform_integral_promotions (idx);
2231 /* An array that is indexed by a non-constant
2232 cannot be stored in a register; we must be able to do
2233 address arithmetic on its address.
2234 Likewise an array of elements of variable size. */
2235 if (TREE_CODE (idx) != INTEGER_CST
2236 || (COMPLETE_TYPE_P (TREE_TYPE (TREE_TYPE (array)))
2237 && (TREE_CODE (TYPE_SIZE (TREE_TYPE (TREE_TYPE (array))))
2240 if (!cxx_mark_addressable (array))
2241 return error_mark_node;
2244 /* An array that is indexed by a constant value which is not within
2245 the array bounds cannot be stored in a register either; because we
2246 would get a crash in store_bit_field/extract_bit_field when trying
2247 to access a non-existent part of the register. */
2248 if (TREE_CODE (idx) == INTEGER_CST
2249 && TYPE_DOMAIN (TREE_TYPE (array))
2250 && ! int_fits_type_p (idx, TYPE_DOMAIN (TREE_TYPE (array))))
2252 if (!cxx_mark_addressable (array))
2253 return error_mark_node;
2256 if (pedantic && !lvalue_p (array))
2257 pedwarn ("ISO C++ forbids subscripting non-lvalue array");
2259 /* Note in C++ it is valid to subscript a `register' array, since
2260 it is valid to take the address of something with that
2261 storage specification. */
2265 while (TREE_CODE (foo) == COMPONENT_REF)
2266 foo = TREE_OPERAND (foo, 0);
2267 if (TREE_CODE (foo) == VAR_DECL && DECL_REGISTER (foo))
2268 warning ("subscripting array declared %<register%>");
2271 type = TREE_TYPE (TREE_TYPE (array));
2272 rval = build4 (ARRAY_REF, type, array, idx, NULL_TREE, NULL_TREE);
2273 /* Array ref is const/volatile if the array elements are
2274 or if the array is.. */
2275 TREE_READONLY (rval)
2276 |= (CP_TYPE_CONST_P (type) | TREE_READONLY (array));
2277 TREE_SIDE_EFFECTS (rval)
2278 |= (CP_TYPE_VOLATILE_P (type) | TREE_SIDE_EFFECTS (array));
2279 TREE_THIS_VOLATILE (rval)
2280 |= (CP_TYPE_VOLATILE_P (type) | TREE_THIS_VOLATILE (array));
2281 return require_complete_type (fold_if_not_in_template (rval));
2285 tree ar = default_conversion (array);
2286 tree ind = default_conversion (idx);
2288 /* Put the integer in IND to simplify error checking. */
2289 if (TREE_CODE (TREE_TYPE (ar)) == INTEGER_TYPE)
2296 if (ar == error_mark_node)
2299 if (TREE_CODE (TREE_TYPE (ar)) != POINTER_TYPE)
2301 error ("subscripted value is neither array nor pointer");
2302 return error_mark_node;
2304 if (TREE_CODE (TREE_TYPE (ind)) != INTEGER_TYPE)
2306 error ("array subscript is not an integer");
2307 return error_mark_node;
2310 return build_indirect_ref (cp_build_binary_op (PLUS_EXPR, ar, ind),
2315 /* Resolve a pointer to member function. INSTANCE is the object
2316 instance to use, if the member points to a virtual member.
2318 This used to avoid checking for virtual functions if basetype
2319 has no virtual functions, according to an earlier ANSI draft.
2320 With the final ISO C++ rules, such an optimization is
2321 incorrect: A pointer to a derived member can be static_cast
2322 to pointer-to-base-member, as long as the dynamic object
2323 later has the right member. */
2326 get_member_function_from_ptrfunc (tree *instance_ptrptr, tree function)
2328 if (TREE_CODE (function) == OFFSET_REF)
2329 function = TREE_OPERAND (function, 1);
2331 if (TYPE_PTRMEMFUNC_P (TREE_TYPE (function)))
2333 tree idx, delta, e1, e2, e3, vtbl, basetype;
2334 tree fntype = TYPE_PTRMEMFUNC_FN_TYPE (TREE_TYPE (function));
2336 tree instance_ptr = *instance_ptrptr;
2337 tree instance_save_expr = 0;
2338 if (instance_ptr == error_mark_node)
2340 if (TREE_CODE (function) == PTRMEM_CST)
2342 /* Extracting the function address from a pmf is only
2343 allowed with -Wno-pmf-conversions. It only works for
2345 e1 = build_addr_func (PTRMEM_CST_MEMBER (function));
2346 e1 = convert (fntype, e1);
2351 error ("object missing in use of %qE", function);
2352 return error_mark_node;
2356 if (TREE_SIDE_EFFECTS (instance_ptr))
2357 instance_ptr = instance_save_expr = save_expr (instance_ptr);
2359 if (TREE_SIDE_EFFECTS (function))
2360 function = save_expr (function);
2362 /* Start by extracting all the information from the PMF itself. */
2363 e3 = PFN_FROM_PTRMEMFUNC (function);
2364 delta = build_ptrmemfunc_access_expr (function, delta_identifier);
2365 idx = build1 (NOP_EXPR, vtable_index_type, e3);
2366 switch (TARGET_PTRMEMFUNC_VBIT_LOCATION)
2368 case ptrmemfunc_vbit_in_pfn:
2369 e1 = cp_build_binary_op (BIT_AND_EXPR, idx, integer_one_node);
2370 idx = cp_build_binary_op (MINUS_EXPR, idx, integer_one_node);
2373 case ptrmemfunc_vbit_in_delta:
2374 e1 = cp_build_binary_op (BIT_AND_EXPR, delta, integer_one_node);
2375 delta = cp_build_binary_op (RSHIFT_EXPR, delta, integer_one_node);
2382 /* Convert down to the right base before using the instance. First
2384 basetype = TYPE_METHOD_BASETYPE (TREE_TYPE (fntype));
2385 basetype = lookup_base (TREE_TYPE (TREE_TYPE (instance_ptr)),
2386 basetype, ba_check, NULL);
2387 instance_ptr = build_base_path (PLUS_EXPR, instance_ptr, basetype, 1);
2388 if (instance_ptr == error_mark_node)
2389 return error_mark_node;
2390 /* ...and then the delta in the PMF. */
2391 instance_ptr = build2 (PLUS_EXPR, TREE_TYPE (instance_ptr),
2392 instance_ptr, delta);
2394 /* Hand back the adjusted 'this' argument to our caller. */
2395 *instance_ptrptr = instance_ptr;
2397 /* Next extract the vtable pointer from the object. */
2398 vtbl = build1 (NOP_EXPR, build_pointer_type (vtbl_ptr_type_node),
2400 vtbl = build_indirect_ref (vtbl, NULL);
2402 /* Finally, extract the function pointer from the vtable. */
2403 e2 = fold (build2 (PLUS_EXPR, TREE_TYPE (vtbl), vtbl, idx));
2404 e2 = build_indirect_ref (e2, NULL);
2405 TREE_CONSTANT (e2) = 1;
2406 TREE_INVARIANT (e2) = 1;
2408 /* When using function descriptors, the address of the
2409 vtable entry is treated as a function pointer. */
2410 if (TARGET_VTABLE_USES_DESCRIPTORS)
2411 e2 = build1 (NOP_EXPR, TREE_TYPE (e2),
2412 build_unary_op (ADDR_EXPR, e2, /*noconvert=*/1));
2414 TREE_TYPE (e2) = TREE_TYPE (e3);
2415 e1 = build_conditional_expr (e1, e2, e3);
2417 /* Make sure this doesn't get evaluated first inside one of the
2418 branches of the COND_EXPR. */
2419 if (instance_save_expr)
2420 e1 = build2 (COMPOUND_EXPR, TREE_TYPE (e1),
2421 instance_save_expr, e1);
2429 build_function_call (tree function, tree params)
2431 tree fntype, fndecl;
2432 tree coerced_params;
2433 tree name = NULL_TREE;
2435 tree original = function;
2437 /* build_c_cast puts on a NOP_EXPR to make the result not an lvalue.
2438 Strip such NOP_EXPRs, since FUNCTION is used in non-lvalue context. */
2439 if (TREE_CODE (function) == NOP_EXPR
2440 && TREE_TYPE (function) == TREE_TYPE (TREE_OPERAND (function, 0)))
2441 function = TREE_OPERAND (function, 0);
2443 if (TREE_CODE (function) == FUNCTION_DECL)
2445 name = DECL_NAME (function);
2447 mark_used (function);
2450 /* Convert anything with function type to a pointer-to-function. */
2451 if (pedantic && DECL_MAIN_P (function))
2452 pedwarn ("ISO C++ forbids calling %<::main%> from within program");
2454 /* Differs from default_conversion by not setting TREE_ADDRESSABLE
2455 (because calling an inline function does not mean the function
2456 needs to be separately compiled). */
2458 if (DECL_INLINE (function))
2459 function = inline_conversion (function);
2461 function = build_addr_func (function);
2467 function = build_addr_func (function);
2470 if (function == error_mark_node)
2471 return error_mark_node;
2473 fntype = TREE_TYPE (function);
2475 if (TYPE_PTRMEMFUNC_P (fntype))
2477 error ("must use %<.*%> or %<->*%> to call pointer-to-member "
2478 "function in %<%E (...)%>",
2480 return error_mark_node;
2483 is_method = (TREE_CODE (fntype) == POINTER_TYPE
2484 && TREE_CODE (TREE_TYPE (fntype)) == METHOD_TYPE);
2486 if (!((TREE_CODE (fntype) == POINTER_TYPE
2487 && TREE_CODE (TREE_TYPE (fntype)) == FUNCTION_TYPE)
2489 || TREE_CODE (function) == TEMPLATE_ID_EXPR))
2491 error ("%qE cannot be used as a function", original);
2492 return error_mark_node;
2495 /* fntype now gets the type of function pointed to. */
2496 fntype = TREE_TYPE (fntype);
2498 /* Convert the parameters to the types declared in the
2499 function prototype, or apply default promotions. */
2501 coerced_params = convert_arguments (TYPE_ARG_TYPES (fntype),
2502 params, fndecl, LOOKUP_NORMAL);
2503 if (coerced_params == error_mark_node)
2504 return error_mark_node;
2506 /* Check for errors in format strings and inappropriately
2509 check_function_arguments (TYPE_ATTRIBUTES (fntype), coerced_params);
2511 return build_cxx_call (function, coerced_params);
2514 /* Convert the actual parameter expressions in the list VALUES
2515 to the types in the list TYPELIST.
2516 If parmdecls is exhausted, or when an element has NULL as its type,
2517 perform the default conversions.
2519 NAME is an IDENTIFIER_NODE or 0. It is used only for error messages.
2521 This is also where warnings about wrong number of args are generated.
2523 Return a list of expressions for the parameters as converted.
2525 Both VALUES and the returned value are chains of TREE_LIST nodes
2526 with the elements of the list in the TREE_VALUE slots of those nodes.
2528 In C++, unspecified trailing parameters can be filled in with their
2529 default arguments, if such were specified. Do so here. */
2532 convert_arguments (tree typelist, tree values, tree fndecl, int flags)
2534 tree typetail, valtail;
2535 tree result = NULL_TREE;
2536 const char *called_thing = 0;
2539 /* Argument passing is always copy-initialization. */
2540 flags |= LOOKUP_ONLYCONVERTING;
2544 if (TREE_CODE (TREE_TYPE (fndecl)) == METHOD_TYPE)
2546 if (DECL_NAME (fndecl) == NULL_TREE
2547 || IDENTIFIER_HAS_TYPE_VALUE (DECL_NAME (fndecl)))
2548 called_thing = "constructor";
2550 called_thing = "member function";
2553 called_thing = "function";
2556 for (valtail = values, typetail = typelist;
2558 valtail = TREE_CHAIN (valtail), i++)
2560 tree type = typetail ? TREE_VALUE (typetail) : 0;
2561 tree val = TREE_VALUE (valtail);
2563 if (val == error_mark_node)
2564 return error_mark_node;
2566 if (type == void_type_node)
2570 cp_error_at ("too many arguments to %s %q+#D", called_thing,
2572 error ("at this point in file");
2575 error ("too many arguments to function");
2576 /* In case anybody wants to know if this argument
2579 TREE_TYPE (tree_last (result)) = error_mark_node;
2583 /* build_c_cast puts on a NOP_EXPR to make the result not an lvalue.
2584 Strip such NOP_EXPRs, since VAL is used in non-lvalue context. */
2585 if (TREE_CODE (val) == NOP_EXPR
2586 && TREE_TYPE (val) == TREE_TYPE (TREE_OPERAND (val, 0))
2587 && (type == 0 || TREE_CODE (type) != REFERENCE_TYPE))
2588 val = TREE_OPERAND (val, 0);
2590 if (type == 0 || TREE_CODE (type) != REFERENCE_TYPE)
2592 if (TREE_CODE (TREE_TYPE (val)) == ARRAY_TYPE
2593 || TREE_CODE (TREE_TYPE (val)) == FUNCTION_TYPE
2594 || TREE_CODE (TREE_TYPE (val)) == METHOD_TYPE)
2595 val = decay_conversion (val);
2598 if (val == error_mark_node)
2599 return error_mark_node;
2603 /* Formal parm type is specified by a function prototype. */
2606 if (!COMPLETE_TYPE_P (complete_type (type)))
2609 error ("parameter %P of %qD has incomplete type %qT",
2612 error ("parameter %P has incomplete type %qT", i, type);
2613 parmval = error_mark_node;
2617 parmval = convert_for_initialization
2618 (NULL_TREE, type, val, flags,
2619 "argument passing", fndecl, i);
2620 parmval = convert_for_arg_passing (type, parmval);
2623 if (parmval == error_mark_node)
2624 return error_mark_node;
2626 result = tree_cons (NULL_TREE, parmval, result);
2630 if (TREE_CODE (TREE_TYPE (val)) == REFERENCE_TYPE)
2631 val = convert_from_reference (val);
2633 if (fndecl && DECL_BUILT_IN (fndecl)
2634 && DECL_FUNCTION_CODE (fndecl) == BUILT_IN_CONSTANT_P)
2635 /* Don't do ellipsis conversion for __built_in_constant_p
2636 as this will result in spurious warnings for non-POD
2638 val = require_complete_type (val);
2640 val = convert_arg_to_ellipsis (val);
2642 result = tree_cons (NULL_TREE, val, result);
2646 typetail = TREE_CHAIN (typetail);
2649 if (typetail != 0 && typetail != void_list_node)
2651 /* See if there are default arguments that can be used. */
2652 if (TREE_PURPOSE (typetail)
2653 && TREE_CODE (TREE_PURPOSE (typetail)) != DEFAULT_ARG)
2655 for (; typetail != void_list_node; ++i)
2658 = convert_default_arg (TREE_VALUE (typetail),
2659 TREE_PURPOSE (typetail),
2662 if (parmval == error_mark_node)
2663 return error_mark_node;
2665 result = tree_cons (0, parmval, result);
2666 typetail = TREE_CHAIN (typetail);
2667 /* ends with `...'. */
2668 if (typetail == NULL_TREE)
2676 cp_error_at ("too few arguments to %s %q+#D",
2677 called_thing, fndecl);
2678 error ("at this point in file");
2681 error ("too few arguments to function");
2682 return error_mark_list;
2686 return nreverse (result);
2689 /* Build a binary-operation expression, after performing default
2690 conversions on the operands. CODE is the kind of expression to build. */
2693 build_x_binary_op (enum tree_code code, tree arg1, tree arg2,
2703 if (processing_template_decl)
2705 if (type_dependent_expression_p (arg1)
2706 || type_dependent_expression_p (arg2))
2707 return build_min_nt (code, arg1, arg2);
2708 arg1 = build_non_dependent_expr (arg1);
2709 arg2 = build_non_dependent_expr (arg2);
2712 if (code == DOTSTAR_EXPR)
2713 expr = build_m_component_ref (arg1, arg2);
2715 expr = build_new_op (code, LOOKUP_NORMAL, arg1, arg2, NULL_TREE,
2718 if (processing_template_decl && expr != error_mark_node)
2719 return build_min_non_dep (code, expr, orig_arg1, orig_arg2);
2724 /* Build a binary-operation expression without default conversions.
2725 CODE is the kind of expression to build.
2726 This function differs from `build' in several ways:
2727 the data type of the result is computed and recorded in it,
2728 warnings are generated if arg data types are invalid,
2729 special handling for addition and subtraction of pointers is known,
2730 and some optimization is done (operations on narrow ints
2731 are done in the narrower type when that gives the same result).
2732 Constant folding is also done before the result is returned.
2734 Note that the operands will never have enumeral types
2735 because either they have just had the default conversions performed
2736 or they have both just been converted to some other type in which
2737 the arithmetic is to be done.
2739 C++: must do special pointer arithmetic when implementing
2740 multiple inheritance, and deal with pointer to member functions. */
2743 build_binary_op (enum tree_code code, tree orig_op0, tree orig_op1,
2744 int convert_p ATTRIBUTE_UNUSED)
2747 enum tree_code code0, code1;
2750 /* Expression code to give to the expression when it is built.
2751 Normally this is CODE, which is what the caller asked for,
2752 but in some special cases we change it. */
2753 enum tree_code resultcode = code;
2755 /* Data type in which the computation is to be performed.
2756 In the simplest cases this is the common type of the arguments. */
2757 tree result_type = NULL;
2759 /* Nonzero means operands have already been type-converted
2760 in whatever way is necessary.
2761 Zero means they need to be converted to RESULT_TYPE. */
2764 /* Nonzero means create the expression with this type, rather than
2766 tree build_type = 0;
2768 /* Nonzero means after finally constructing the expression
2769 convert it to this type. */
2770 tree final_type = 0;
2774 /* Nonzero if this is an operation like MIN or MAX which can
2775 safely be computed in short if both args are promoted shorts.
2776 Also implies COMMON.
2777 -1 indicates a bitwise operation; this makes a difference
2778 in the exact conditions for when it is safe to do the operation
2779 in a narrower mode. */
2782 /* Nonzero if this is a comparison operation;
2783 if both args are promoted shorts, compare the original shorts.
2784 Also implies COMMON. */
2785 int short_compare = 0;
2787 /* Nonzero if this is a right-shift operation, which can be computed on the
2788 original short and then promoted if the operand is a promoted short. */
2789 int short_shift = 0;
2791 /* Nonzero means set RESULT_TYPE to the common type of the args. */
2794 /* True if both operands have arithmetic type. */
2795 bool arithmetic_types_p;
2797 /* Apply default conversions. */
2801 if (code == TRUTH_AND_EXPR || code == TRUTH_ANDIF_EXPR
2802 || code == TRUTH_OR_EXPR || code == TRUTH_ORIF_EXPR
2803 || code == TRUTH_XOR_EXPR)
2805 if (!really_overloaded_fn (op0))
2806 op0 = decay_conversion (op0);
2807 if (!really_overloaded_fn (op1))
2808 op1 = decay_conversion (op1);
2812 if (!really_overloaded_fn (op0))
2813 op0 = default_conversion (op0);
2814 if (!really_overloaded_fn (op1))
2815 op1 = default_conversion (op1);
2818 /* Strip NON_LVALUE_EXPRs, etc., since we aren't using as an lvalue. */
2819 STRIP_TYPE_NOPS (op0);
2820 STRIP_TYPE_NOPS (op1);
2822 /* DTRT if one side is an overloaded function, but complain about it. */
2823 if (type_unknown_p (op0))
2825 tree t = instantiate_type (TREE_TYPE (op1), op0, tf_none);
2826 if (t != error_mark_node)
2828 pedwarn ("assuming cast to type %qT from overloaded function",
2833 if (type_unknown_p (op1))
2835 tree t = instantiate_type (TREE_TYPE (op0), op1, tf_none);
2836 if (t != error_mark_node)
2838 pedwarn ("assuming cast to type %qT from overloaded function",
2844 type0 = TREE_TYPE (op0);
2845 type1 = TREE_TYPE (op1);
2847 /* The expression codes of the data types of the arguments tell us
2848 whether the arguments are integers, floating, pointers, etc. */
2849 code0 = TREE_CODE (type0);
2850 code1 = TREE_CODE (type1);
2852 /* If an error was already reported for one of the arguments,
2853 avoid reporting another error. */
2855 if (code0 == ERROR_MARK || code1 == ERROR_MARK)
2856 return error_mark_node;
2861 /* Handle the pointer + int case. */
2862 if (code0 == POINTER_TYPE && code1 == INTEGER_TYPE)
2863 return cp_pointer_int_sum (PLUS_EXPR, op0, op1);
2864 else if (code1 == POINTER_TYPE && code0 == INTEGER_TYPE)
2865 return cp_pointer_int_sum (PLUS_EXPR, op1, op0);
2871 /* Subtraction of two similar pointers.
2872 We must subtract them as integers, then divide by object size. */
2873 if (code0 == POINTER_TYPE && code1 == POINTER_TYPE
2874 && same_type_ignoring_top_level_qualifiers_p (TREE_TYPE (type0),
2876 return pointer_diff (op0, op1, common_type (type0, type1));
2877 /* Handle pointer minus int. Just like pointer plus int. */
2878 else if (code0 == POINTER_TYPE && code1 == INTEGER_TYPE)
2879 return cp_pointer_int_sum (MINUS_EXPR, op0, op1);
2888 case TRUNC_DIV_EXPR:
2890 case FLOOR_DIV_EXPR:
2891 case ROUND_DIV_EXPR:
2892 case EXACT_DIV_EXPR:
2893 if ((code0 == INTEGER_TYPE || code0 == REAL_TYPE
2894 || code0 == COMPLEX_TYPE || code0 == VECTOR_TYPE)
2895 && (code1 == INTEGER_TYPE || code1 == REAL_TYPE
2896 || code1 == COMPLEX_TYPE || code1 == VECTOR_TYPE))
2898 if (TREE_CODE (op1) == INTEGER_CST && integer_zerop (op1))
2899 warning ("division by zero in %<%E / 0%>", op0);
2900 else if (TREE_CODE (op1) == REAL_CST && real_zerop (op1))
2901 warning ("division by zero in %<%E / 0.%>", op0);
2903 if (code0 == COMPLEX_TYPE || code0 == VECTOR_TYPE)
2904 code0 = TREE_CODE (TREE_TYPE (TREE_TYPE (op0)));
2905 if (code1 == COMPLEX_TYPE || code1 == VECTOR_TYPE)
2906 code1 = TREE_CODE (TREE_TYPE (TREE_TYPE (op1)));
2908 if (!(code0 == INTEGER_TYPE && code1 == INTEGER_TYPE))
2909 resultcode = RDIV_EXPR;
2911 /* When dividing two signed integers, we have to promote to int.
2912 unless we divide by a constant != -1. Note that default
2913 conversion will have been performed on the operands at this
2914 point, so we have to dig out the original type to find out if
2916 shorten = ((TREE_CODE (op0) == NOP_EXPR
2917 && TYPE_UNSIGNED (TREE_TYPE (TREE_OPERAND (op0, 0))))
2918 || (TREE_CODE (op1) == INTEGER_CST
2919 && ! integer_all_onesp (op1)));
2928 if (code0 == INTEGER_TYPE && code1 == INTEGER_TYPE)
2932 case TRUNC_MOD_EXPR:
2933 case FLOOR_MOD_EXPR:
2934 if (code1 == INTEGER_TYPE && integer_zerop (op1))
2935 warning ("division by zero in %<%E %% 0%>", op0);
2936 else if (code1 == REAL_TYPE && real_zerop (op1))
2937 warning ("division by zero in %<%E %% 0.%>", op0);
2939 if (code0 == INTEGER_TYPE && code1 == INTEGER_TYPE)
2941 /* Although it would be tempting to shorten always here, that loses
2942 on some targets, since the modulo instruction is undefined if the
2943 quotient can't be represented in the computation mode. We shorten
2944 only if unsigned or if dividing by something we know != -1. */
2945 shorten = ((TREE_CODE (op0) == NOP_EXPR
2946 && TYPE_UNSIGNED (TREE_TYPE (TREE_OPERAND (op0, 0))))
2947 || (TREE_CODE (op1) == INTEGER_CST
2948 && ! integer_all_onesp (op1)));
2953 case TRUTH_ANDIF_EXPR:
2954 case TRUTH_ORIF_EXPR:
2955 case TRUTH_AND_EXPR:
2957 result_type = boolean_type_node;
2960 /* Shift operations: result has same type as first operand;
2961 always convert second operand to int.
2962 Also set SHORT_SHIFT if shifting rightward. */
2965 if (code0 == INTEGER_TYPE && code1 == INTEGER_TYPE)
2967 result_type = type0;
2968 if (TREE_CODE (op1) == INTEGER_CST)
2970 if (tree_int_cst_lt (op1, integer_zero_node))
2971 warning ("right shift count is negative");
2974 if (! integer_zerop (op1))
2976 if (compare_tree_int (op1, TYPE_PRECISION (type0)) >= 0)
2977 warning ("right shift count >= width of type");
2980 /* Convert the shift-count to an integer, regardless of
2981 size of value being shifted. */
2982 if (TYPE_MAIN_VARIANT (TREE_TYPE (op1)) != integer_type_node)
2983 op1 = cp_convert (integer_type_node, op1);
2984 /* Avoid converting op1 to result_type later. */
2990 if (code0 == INTEGER_TYPE && code1 == INTEGER_TYPE)
2992 result_type = type0;
2993 if (TREE_CODE (op1) == INTEGER_CST)
2995 if (tree_int_cst_lt (op1, integer_zero_node))
2996 warning ("left shift count is negative");
2997 else if (compare_tree_int (op1, TYPE_PRECISION (type0)) >= 0)
2998 warning ("left shift count >= width of type");
3000 /* Convert the shift-count to an integer, regardless of
3001 size of value being shifted. */
3002 if (TYPE_MAIN_VARIANT (TREE_TYPE (op1)) != integer_type_node)
3003 op1 = cp_convert (integer_type_node, op1);
3004 /* Avoid converting op1 to result_type later. */
3011 if (code0 == INTEGER_TYPE && code1 == INTEGER_TYPE)
3013 result_type = type0;
3014 if (TREE_CODE (op1) == INTEGER_CST)
3016 if (tree_int_cst_lt (op1, integer_zero_node))
3017 warning ("%s rotate count is negative",
3018 (code == LROTATE_EXPR) ? "left" : "right");
3019 else if (compare_tree_int (op1, TYPE_PRECISION (type0)) >= 0)
3020 warning ("%s rotate count >= width of type",
3021 (code == LROTATE_EXPR) ? "left" : "right");
3023 /* Convert the shift-count to an integer, regardless of
3024 size of value being shifted. */
3025 if (TYPE_MAIN_VARIANT (TREE_TYPE (op1)) != integer_type_node)
3026 op1 = cp_convert (integer_type_node, op1);
3032 if (warn_float_equal && (code0 == REAL_TYPE || code1 == REAL_TYPE))
3033 warning ("comparing floating point with == or != is unsafe");
3035 build_type = boolean_type_node;
3036 if ((code0 == INTEGER_TYPE || code0 == REAL_TYPE
3037 || code0 == COMPLEX_TYPE)
3038 && (code1 == INTEGER_TYPE || code1 == REAL_TYPE
3039 || code1 == COMPLEX_TYPE))
3041 else if ((code0 == POINTER_TYPE && code1 == POINTER_TYPE)
3042 || (TYPE_PTRMEM_P (type0) && TYPE_PTRMEM_P (type1)))
3043 result_type = composite_pointer_type (type0, type1, op0, op1,
3045 else if ((code0 == POINTER_TYPE || TYPE_PTRMEM_P (type0))
3046 && null_ptr_cst_p (op1))
3047 result_type = type0;
3048 else if ((code1 == POINTER_TYPE || TYPE_PTRMEM_P (type1))
3049 && null_ptr_cst_p (op0))
3050 result_type = type1;
3051 else if (code0 == POINTER_TYPE && code1 == INTEGER_TYPE)
3053 result_type = type0;
3054 error ("ISO C++ forbids comparison between pointer and integer");
3056 else if (code0 == INTEGER_TYPE && code1 == POINTER_TYPE)
3058 result_type = type1;
3059 error ("ISO C++ forbids comparison between pointer and integer");
3061 else if (TYPE_PTRMEMFUNC_P (type0) && null_ptr_cst_p (op1))
3063 op0 = build_ptrmemfunc_access_expr (op0, pfn_identifier);
3064 op1 = cp_convert (TREE_TYPE (op0), integer_zero_node);
3065 result_type = TREE_TYPE (op0);
3067 else if (TYPE_PTRMEMFUNC_P (type1) && null_ptr_cst_p (op0))
3068 return cp_build_binary_op (code, op1, op0);
3069 else if (TYPE_PTRMEMFUNC_P (type0) && TYPE_PTRMEMFUNC_P (type1)
3070 && same_type_p (type0, type1))
3072 /* E will be the final comparison. */
3074 /* E1 and E2 are for scratch. */
3082 if (TREE_SIDE_EFFECTS (op0))
3083 op0 = save_expr (op0);
3084 if (TREE_SIDE_EFFECTS (op1))
3085 op1 = save_expr (op1);
3090 && (!op0.pfn || op0.delta == op1.delta))
3092 The reason for the `!op0.pfn' bit is that a NULL
3093 pointer-to-member is any member with a zero PFN; the
3094 DELTA field is unspecified. */
3095 pfn0 = pfn_from_ptrmemfunc (op0);
3096 pfn1 = pfn_from_ptrmemfunc (op1);
3097 delta0 = build_ptrmemfunc_access_expr (op0,
3099 delta1 = build_ptrmemfunc_access_expr (op1,
3101 e1 = cp_build_binary_op (EQ_EXPR, delta0, delta1);
3102 e2 = cp_build_binary_op (EQ_EXPR,
3104 cp_convert (TREE_TYPE (pfn0),
3105 integer_zero_node));
3106 e1 = cp_build_binary_op (TRUTH_ORIF_EXPR, e1, e2);
3107 e2 = build2 (EQ_EXPR, boolean_type_node, pfn0, pfn1);
3108 e = cp_build_binary_op (TRUTH_ANDIF_EXPR, e2, e1);
3109 if (code == EQ_EXPR)
3111 return cp_build_binary_op (EQ_EXPR, e, integer_zero_node);
3115 gcc_assert (!TYPE_PTRMEMFUNC_P (type0)
3116 || !same_type_p (TYPE_PTRMEMFUNC_FN_TYPE (type0),
3118 gcc_assert (!TYPE_PTRMEMFUNC_P (type1)
3119 || !same_type_p (TYPE_PTRMEMFUNC_FN_TYPE (type1),
3127 if ((code0 == INTEGER_TYPE || code0 == REAL_TYPE)
3128 && (code1 == INTEGER_TYPE || code1 == REAL_TYPE))
3130 else if (code0 == POINTER_TYPE && code1 == POINTER_TYPE)
3131 result_type = composite_pointer_type (type0, type1, op0, op1,
3139 build_type = boolean_type_node;
3140 if ((code0 == INTEGER_TYPE || code0 == REAL_TYPE)
3141 && (code1 == INTEGER_TYPE || code1 == REAL_TYPE))
3143 else if (code0 == POINTER_TYPE && code1 == POINTER_TYPE)
3144 result_type = composite_pointer_type (type0, type1, op0, op1,
3146 else if (code0 == POINTER_TYPE && TREE_CODE (op1) == INTEGER_CST
3147 && integer_zerop (op1))
3148 result_type = type0;
3149 else if (code1 == POINTER_TYPE && TREE_CODE (op0) == INTEGER_CST
3150 && integer_zerop (op0))
3151 result_type = type1;
3152 else if (code0 == POINTER_TYPE && code1 == INTEGER_TYPE)
3154 result_type = type0;
3155 pedwarn ("ISO C++ forbids comparison between pointer and integer");
3157 else if (code0 == INTEGER_TYPE && code1 == POINTER_TYPE)
3159 result_type = type1;
3160 pedwarn ("ISO C++ forbids comparison between pointer and integer");
3164 case UNORDERED_EXPR:
3171 build_type = integer_type_node;
3172 if (code0 != REAL_TYPE || code1 != REAL_TYPE)
3174 error ("unordered comparison on non-floating point argument");
3175 return error_mark_node;
3184 arithmetic_types_p =
3185 ((code0 == INTEGER_TYPE || code0 == REAL_TYPE || code0 == COMPLEX_TYPE)
3186 && (code1 == INTEGER_TYPE || code1 == REAL_TYPE
3187 || code1 == COMPLEX_TYPE));
3188 /* Determine the RESULT_TYPE, if it is not already known. */
3190 && arithmetic_types_p
3191 && (shorten || common || short_compare))
3192 result_type = common_type (type0, type1);
3196 error ("invalid operands of types %qT and %qT to binary %qO",
3197 TREE_TYPE (orig_op0), TREE_TYPE (orig_op1), code);
3198 return error_mark_node;
3201 /* If we're in a template, the only thing we need to know is the
3203 if (processing_template_decl)
3204 return build2 (resultcode,
3205 build_type ? build_type : result_type,
3208 if (arithmetic_types_p)
3210 int none_complex = (code0 != COMPLEX_TYPE && code1 != COMPLEX_TYPE);
3212 /* For certain operations (which identify themselves by shorten != 0)
3213 if both args were extended from the same smaller type,
3214 do the arithmetic in that type and then extend.
3216 shorten !=0 and !=1 indicates a bitwise operation.
3217 For them, this optimization is safe only if
3218 both args are zero-extended or both are sign-extended.
3219 Otherwise, we might change the result.
3220 Eg, (short)-1 | (unsigned short)-1 is (int)-1
3221 but calculated in (unsigned short) it would be (unsigned short)-1. */
3223 if (shorten && none_complex)
3225 int unsigned0, unsigned1;
3226 tree arg0 = get_narrower (op0, &unsigned0);
3227 tree arg1 = get_narrower (op1, &unsigned1);
3228 /* UNS is 1 if the operation to be done is an unsigned one. */
3229 int uns = TYPE_UNSIGNED (result_type);
3232 final_type = result_type;
3234 /* Handle the case that OP0 does not *contain* a conversion
3235 but it *requires* conversion to FINAL_TYPE. */
3237 if (op0 == arg0 && TREE_TYPE (op0) != final_type)
3238 unsigned0 = TYPE_UNSIGNED (TREE_TYPE (op0));
3239 if (op1 == arg1 && TREE_TYPE (op1) != final_type)
3240 unsigned1 = TYPE_UNSIGNED (TREE_TYPE (op1));
3242 /* Now UNSIGNED0 is 1 if ARG0 zero-extends to FINAL_TYPE. */
3244 /* For bitwise operations, signedness of nominal type
3245 does not matter. Consider only how operands were extended. */
3249 /* Note that in all three cases below we refrain from optimizing
3250 an unsigned operation on sign-extended args.
3251 That would not be valid. */
3253 /* Both args variable: if both extended in same way
3254 from same width, do it in that width.
3255 Do it unsigned if args were zero-extended. */
3256 if ((TYPE_PRECISION (TREE_TYPE (arg0))
3257 < TYPE_PRECISION (result_type))
3258 && (TYPE_PRECISION (TREE_TYPE (arg1))
3259 == TYPE_PRECISION (TREE_TYPE (arg0)))
3260 && unsigned0 == unsigned1
3261 && (unsigned0 || !uns))
3262 result_type = c_common_signed_or_unsigned_type
3263 (unsigned0, common_type (TREE_TYPE (arg0), TREE_TYPE (arg1)));
3264 else if (TREE_CODE (arg0) == INTEGER_CST
3265 && (unsigned1 || !uns)
3266 && (TYPE_PRECISION (TREE_TYPE (arg1))
3267 < TYPE_PRECISION (result_type))
3268 && (type = c_common_signed_or_unsigned_type
3269 (unsigned1, TREE_TYPE (arg1)),
3270 int_fits_type_p (arg0, type)))
3272 else if (TREE_CODE (arg1) == INTEGER_CST
3273 && (unsigned0 || !uns)
3274 && (TYPE_PRECISION (TREE_TYPE (arg0))
3275 < TYPE_PRECISION (result_type))
3276 && (type = c_common_signed_or_unsigned_type
3277 (unsigned0, TREE_TYPE (arg0)),
3278 int_fits_type_p (arg1, type)))
3282 /* Shifts can be shortened if shifting right. */
3287 tree arg0 = get_narrower (op0, &unsigned_arg);
3289 final_type = result_type;
3291 if (arg0 == op0 && final_type == TREE_TYPE (op0))
3292 unsigned_arg = TYPE_UNSIGNED (TREE_TYPE (op0));
3294 if (TYPE_PRECISION (TREE_TYPE (arg0)) < TYPE_PRECISION (result_type)
3295 /* We can shorten only if the shift count is less than the
3296 number of bits in the smaller type size. */
3297 && compare_tree_int (op1, TYPE_PRECISION (TREE_TYPE (arg0))) < 0
3298 /* If arg is sign-extended and then unsigned-shifted,
3299 we can simulate this with a signed shift in arg's type
3300 only if the extended result is at least twice as wide
3301 as the arg. Otherwise, the shift could use up all the
3302 ones made by sign-extension and bring in zeros.
3303 We can't optimize that case at all, but in most machines
3304 it never happens because available widths are 2**N. */
3305 && (!TYPE_UNSIGNED (final_type)
3307 || (((unsigned) 2 * TYPE_PRECISION (TREE_TYPE (arg0)))
3308 <= TYPE_PRECISION (result_type))))
3310 /* Do an unsigned shift if the operand was zero-extended. */
3312 = c_common_signed_or_unsigned_type (unsigned_arg,
3314 /* Convert value-to-be-shifted to that type. */
3315 if (TREE_TYPE (op0) != result_type)
3316 op0 = cp_convert (result_type, op0);
3321 /* Comparison operations are shortened too but differently.
3322 They identify themselves by setting short_compare = 1. */
3326 /* Don't write &op0, etc., because that would prevent op0
3327 from being kept in a register.
3328 Instead, make copies of the our local variables and
3329 pass the copies by reference, then copy them back afterward. */
3330 tree xop0 = op0, xop1 = op1, xresult_type = result_type;
3331 enum tree_code xresultcode = resultcode;
3333 = shorten_compare (&xop0, &xop1, &xresult_type, &xresultcode);
3335 return cp_convert (boolean_type_node, val);
3336 op0 = xop0, op1 = xop1;
3338 resultcode = xresultcode;
3341 if ((short_compare || code == MIN_EXPR || code == MAX_EXPR)
3342 && warn_sign_compare
3343 /* Do not warn until the template is instantiated; we cannot
3344 bound the ranges of the arguments until that point. */
3345 && !processing_template_decl)
3347 int op0_signed = !TYPE_UNSIGNED (TREE_TYPE (orig_op0));
3348 int op1_signed = !TYPE_UNSIGNED (TREE_TYPE (orig_op1));
3350 int unsignedp0, unsignedp1;
3351 tree primop0 = get_narrower (op0, &unsignedp0);
3352 tree primop1 = get_narrower (op1, &unsignedp1);
3354 /* Check for comparison of different enum types. */
3355 if (TREE_CODE (TREE_TYPE (orig_op0)) == ENUMERAL_TYPE
3356 && TREE_CODE (TREE_TYPE (orig_op1)) == ENUMERAL_TYPE
3357 && TYPE_MAIN_VARIANT (TREE_TYPE (orig_op0))
3358 != TYPE_MAIN_VARIANT (TREE_TYPE (orig_op1)))
3360 warning ("comparison between types %q#T and %q#T",
3361 TREE_TYPE (orig_op0), TREE_TYPE (orig_op1));
3364 /* Give warnings for comparisons between signed and unsigned
3365 quantities that may fail. */
3366 /* Do the checking based on the original operand trees, so that
3367 casts will be considered, but default promotions won't be. */
3369 /* Do not warn if the comparison is being done in a signed type,
3370 since the signed type will only be chosen if it can represent
3371 all the values of the unsigned type. */
3372 if (!TYPE_UNSIGNED (result_type))
3374 /* Do not warn if both operands are unsigned. */
3375 else if (op0_signed == op1_signed)
3377 /* Do not warn if the signed quantity is an unsuffixed
3378 integer literal (or some static constant expression
3379 involving such literals or a conditional expression
3380 involving such literals) and it is non-negative. */
3381 else if ((op0_signed && tree_expr_nonnegative_p (orig_op0))
3382 || (op1_signed && tree_expr_nonnegative_p (orig_op1)))
3384 /* Do not warn if the comparison is an equality operation,
3385 the unsigned quantity is an integral constant and it does
3386 not use the most significant bit of result_type. */
3387 else if ((resultcode == EQ_EXPR || resultcode == NE_EXPR)
3388 && ((op0_signed && TREE_CODE (orig_op1) == INTEGER_CST
3389 && int_fits_type_p (orig_op1, c_common_signed_type
3391 || (op1_signed && TREE_CODE (orig_op0) == INTEGER_CST
3392 && int_fits_type_p (orig_op0, c_common_signed_type
3396 warning ("comparison between signed and unsigned integer expressions");
3398 /* Warn if two unsigned values are being compared in a size
3399 larger than their original size, and one (and only one) is the
3400 result of a `~' operator. This comparison will always fail.
3402 Also warn if one operand is a constant, and the constant does not
3403 have all bits set that are set in the ~ operand when it is
3406 if ((TREE_CODE (primop0) == BIT_NOT_EXPR)
3407 ^ (TREE_CODE (primop1) == BIT_NOT_EXPR))
3409 if (TREE_CODE (primop0) == BIT_NOT_EXPR)
3410 primop0 = get_narrower (TREE_OPERAND (op0, 0), &unsignedp0);
3411 if (TREE_CODE (primop1) == BIT_NOT_EXPR)
3412 primop1 = get_narrower (TREE_OPERAND (op1, 0), &unsignedp1);
3414 if (host_integerp (primop0, 0) || host_integerp (primop1, 0))
3417 HOST_WIDE_INT constant, mask;
3421 if (host_integerp (primop0, 0))
3424 unsignedp = unsignedp1;
3425 constant = tree_low_cst (primop0, 0);
3430 unsignedp = unsignedp0;
3431 constant = tree_low_cst (primop1, 0);
3434 bits = TYPE_PRECISION (TREE_TYPE (primop));
3435 if (bits < TYPE_PRECISION (result_type)
3436 && bits < HOST_BITS_PER_LONG && unsignedp)
3438 mask = (~ (HOST_WIDE_INT) 0) << bits;
3439 if ((mask & constant) != mask)
3440 warning ("comparison of promoted ~unsigned with constant");
3443 else if (unsignedp0 && unsignedp1
3444 && (TYPE_PRECISION (TREE_TYPE (primop0))
3445 < TYPE_PRECISION (result_type))
3446 && (TYPE_PRECISION (TREE_TYPE (primop1))
3447 < TYPE_PRECISION (result_type)))
3448 warning ("comparison of promoted ~unsigned with unsigned");
3453 /* If CONVERTED is zero, both args will be converted to type RESULT_TYPE.
3454 Then the expression will be built.
3455 It will be given type FINAL_TYPE if that is nonzero;
3456 otherwise, it will be given type RESULT_TYPE. */
3458 /* Issue warnings about peculiar, but valid, uses of NULL. */
3459 if (/* It's reasonable to use pointer values as operands of &&
3460 and ||, so NULL is no exception. */
3461 !(code == TRUTH_ANDIF_EXPR || code == TRUTH_ORIF_EXPR)
3462 && (/* If OP0 is NULL and OP1 is not a pointer, or vice versa. */
3463 (orig_op0 == null_node
3464 && TREE_CODE (TREE_TYPE (op1)) != POINTER_TYPE)
3465 /* Or vice versa. */
3466 || (orig_op1 == null_node
3467 && TREE_CODE (TREE_TYPE (op0)) != POINTER_TYPE)
3468 /* Or, both are NULL and the operation was not a comparison. */
3469 || (orig_op0 == null_node && orig_op1 == null_node
3470 && code != EQ_EXPR && code != NE_EXPR)))
3471 /* Some sort of arithmetic operation involving NULL was
3472 performed. Note that pointer-difference and pointer-addition
3473 have already been handled above, and so we don't end up here in
3475 warning ("NULL used in arithmetic");
3479 if (TREE_TYPE (op0) != result_type)
3480 op0 = cp_convert (result_type, op0);
3481 if (TREE_TYPE (op1) != result_type)
3482 op1 = cp_convert (result_type, op1);
3484 if (op0 == error_mark_node || op1 == error_mark_node)
3485 return error_mark_node;
3488 if (build_type == NULL_TREE)
3489 build_type = result_type;
3491 result = build2 (resultcode, build_type, op0, op1);
3492 result = fold_if_not_in_template (result);
3493 if (final_type != 0)
3494 result = cp_convert (final_type, result);
3498 /* Return a tree for the sum or difference (RESULTCODE says which)
3499 of pointer PTROP and integer INTOP. */
3502 cp_pointer_int_sum (enum tree_code resultcode, tree ptrop, tree intop)
3504 tree res_type = TREE_TYPE (ptrop);
3506 /* pointer_int_sum() uses size_in_bytes() on the TREE_TYPE(res_type)
3507 in certain circumstance (when it's valid to do so). So we need
3508 to make sure it's complete. We don't need to check here, if we
3509 can actually complete it at all, as those checks will be done in
3510 pointer_int_sum() anyway. */
3511 complete_type (TREE_TYPE (res_type));
3513 return pointer_int_sum (resultcode, ptrop,
3514 fold_if_not_in_template (intop));
3517 /* Return a tree for the difference of pointers OP0 and OP1.
3518 The resulting tree has type int. */
3521 pointer_diff (tree op0, tree op1, tree ptrtype)
3524 tree restype = ptrdiff_type_node;
3525 tree target_type = TREE_TYPE (ptrtype);
3527 if (!complete_type_or_else (target_type, NULL_TREE))
3528 return error_mark_node;
3530 if (pedantic || warn_pointer_arith)
3532 if (TREE_CODE (target_type) == VOID_TYPE)
3533 pedwarn ("ISO C++ forbids using pointer of type %<void *%> in subtraction");
3534 if (TREE_CODE (target_type) == FUNCTION_TYPE)
3535 pedwarn ("ISO C++ forbids using pointer to a function in subtraction");
3536 if (TREE_CODE (target_type) == METHOD_TYPE)
3537 pedwarn ("ISO C++ forbids using pointer to a method in subtraction");
3540 /* First do the subtraction as integers;
3541 then drop through to build the divide operator. */
3543 op0 = cp_build_binary_op (MINUS_EXPR,
3544 cp_convert (restype, op0),
3545 cp_convert (restype, op1));
3547 /* This generates an error if op1 is a pointer to an incomplete type. */
3548 if (!COMPLETE_TYPE_P (TREE_TYPE (TREE_TYPE (op1))))
3549 error ("invalid use of a pointer to an incomplete type in pointer arithmetic");
3551 op1 = (TYPE_PTROB_P (ptrtype)
3552 ? size_in_bytes (target_type)
3553 : integer_one_node);
3555 /* Do the division. */
3557 result = build2 (EXACT_DIV_EXPR, restype, op0, cp_convert (restype, op1));
3558 return fold_if_not_in_template (result);
3561 /* Construct and perhaps optimize a tree representation
3562 for a unary operation. CODE, a tree_code, specifies the operation
3563 and XARG is the operand. */
3566 build_x_unary_op (enum tree_code code, tree xarg)
3568 tree orig_expr = xarg;
3572 if (processing_template_decl)
3574 if (type_dependent_expression_p (xarg))
3575 return build_min_nt (code, xarg, NULL_TREE);
3577 /* For non-dependent pointer-to-member, the SCOPE_REF will be
3578 processed during template substitution. Just compute the
3579 right type here and build an ADDR_EXPR around it for
3581 if (code == ADDR_EXPR && TREE_CODE (xarg) == SCOPE_REF)
3584 if (TREE_TYPE (xarg) == unknown_type_node)
3585 type = unknown_type_node;
3586 else if (TREE_CODE (TREE_TYPE (xarg)) == FUNCTION_TYPE)
3587 type = build_pointer_type (TREE_TYPE (xarg));
3589 type = build_ptrmem_type (TREE_OPERAND (xarg, 0),
3591 return build_min (code, type, xarg, NULL_TREE);
3594 xarg = build_non_dependent_expr (xarg);
3599 /* [expr.unary.op] says:
3601 The address of an object of incomplete type can be taken.
3603 (And is just the ordinary address operator, not an overloaded
3604 "operator &".) However, if the type is a template
3605 specialization, we must complete the type at this point so that
3606 an overloaded "operator &" will be available if required. */
3607 if (code == ADDR_EXPR
3608 && TREE_CODE (xarg) != TEMPLATE_ID_EXPR
3609 && ((CLASS_TYPE_P (TREE_TYPE (xarg))
3610 && !COMPLETE_TYPE_P (complete_type (TREE_TYPE (xarg))))
3611 || (TREE_CODE (xarg) == OFFSET_REF)))
3612 /* Don't look for a function. */;
3614 exp = build_new_op (code, LOOKUP_NORMAL, xarg, NULL_TREE, NULL_TREE,
3615 /*overloaded_p=*/NULL);
3616 if (!exp && code == ADDR_EXPR)
3618 /* A pointer to member-function can be formed only by saying
3620 if (!flag_ms_extensions && TREE_CODE (TREE_TYPE (xarg)) == METHOD_TYPE
3621 && (TREE_CODE (xarg) != OFFSET_REF || !PTRMEM_OK_P (xarg)))
3623 if (TREE_CODE (xarg) != OFFSET_REF)
3625 error ("invalid use of %qE to form a pointer-to-member-function."
3626 " Use a qualified-id.",
3628 return error_mark_node;
3632 error ("parenthesis around %qE cannot be used to form a"
3633 " pointer-to-member-function",
3635 PTRMEM_OK_P (xarg) = 1;
3639 if (TREE_CODE (xarg) == OFFSET_REF)
3641 ptrmem = PTRMEM_OK_P (xarg);
3643 if (!ptrmem && !flag_ms_extensions
3644 && TREE_CODE (TREE_TYPE (TREE_OPERAND (xarg, 1))) == METHOD_TYPE)
3646 /* A single non-static member, make sure we don't allow a
3647 pointer-to-member. */
3648 xarg = build2 (OFFSET_REF, TREE_TYPE (xarg),
3649 TREE_OPERAND (xarg, 0),
3650 ovl_cons (TREE_OPERAND (xarg, 1), NULL_TREE));
3651 PTRMEM_OK_P (xarg) = ptrmem;
3654 else if (TREE_CODE (xarg) == TARGET_EXPR)
3655 warning ("taking address of temporary");
3656 exp = build_unary_op (ADDR_EXPR, xarg, 0);
3657 if (TREE_CODE (exp) == ADDR_EXPR)
3658 PTRMEM_OK_P (exp) = ptrmem;
3661 if (processing_template_decl && exp != error_mark_node)
3662 return build_min_non_dep (code, exp, orig_expr,
3663 /*For {PRE,POST}{INC,DEC}REMENT_EXPR*/NULL_TREE);
3667 /* Like c_common_truthvalue_conversion, but handle pointer-to-member
3668 constants, where a null value is represented by an INTEGER_CST of
3672 cp_truthvalue_conversion (tree expr)
3674 tree type = TREE_TYPE (expr);
3675 if (TYPE_PTRMEM_P (type))
3676 return build_binary_op (NE_EXPR, expr, integer_zero_node, 1);
3678 return c_common_truthvalue_conversion (expr);
3681 /* Just like cp_truthvalue_conversion, but we want a CLEANUP_POINT_EXPR. */
3684 condition_conversion (tree expr)
3687 if (processing_template_decl)
3689 t = perform_implicit_conversion (boolean_type_node, expr);
3690 t = fold_build_cleanup_point_expr (boolean_type_node, t);
3694 /* Return an ADDR_EXPR giving the address of T. This function
3695 attempts no optimizations or simplifications; it is a low-level
3699 build_address (tree t)
3703 if (error_operand_p (t) || !cxx_mark_addressable (t))
3704 return error_mark_node;
3706 addr = build1 (ADDR_EXPR, build_pointer_type (TREE_TYPE (t)), t);
3711 /* Return a NOP_EXPR converting EXPR to TYPE. */
3714 build_nop (tree type, tree expr)
3716 if (type == error_mark_node || error_operand_p (expr))
3718 return build1 (NOP_EXPR, type, expr);
3721 /* C++: Must handle pointers to members.
3723 Perhaps type instantiation should be extended to handle conversion
3724 from aggregates to types we don't yet know we want? (Or are those
3725 cases typically errors which should be reported?)
3727 NOCONVERT nonzero suppresses the default promotions
3728 (such as from short to int). */
3731 build_unary_op (enum tree_code code, tree xarg, int noconvert)
3733 /* No default_conversion here. It causes trouble for ADDR_EXPR. */
3736 const char *errstring = NULL;
3739 if (arg == error_mark_node)
3740 return error_mark_node;
3744 /* CONVERT_EXPR stands for unary plus in this context. */
3748 int flags = WANT_ARITH | WANT_ENUM;
\r
3749 /* Unary plus (but not unary minus) is allowed on pointers. */
\r
3750 if (code == CONVERT_EXPR)
\r
3751 flags |= WANT_POINTER;
\r
3752 arg = build_expr_type_conversion (flags, arg, true);
\r
3754 errstring = (code == NEGATE_EXPR
3755 ? "wrong type argument to unary minus"
3756 : "wrong type argument to unary plus");
3759 if (!noconvert && CP_INTEGRAL_TYPE_P (TREE_TYPE (arg)))
3760 arg = perform_integral_promotions (arg);
3762 /* Make sure the result is not a lvalue: a unary plus or minus
3763 expression is always a rvalue. */
3764 if (real_lvalue_p (arg))
3765 arg = build1 (NON_LVALUE_EXPR, TREE_TYPE (arg), arg);
3771 if (TREE_CODE (TREE_TYPE (arg)) == COMPLEX_TYPE)
3775 arg = default_conversion (arg);
3777 else if (!(arg = build_expr_type_conversion (WANT_INT | WANT_ENUM,
3779 errstring = "wrong type argument to bit-complement";
3780 else if (!noconvert)
3781 arg = perform_integral_promotions (arg);
3785 if (!(arg = build_expr_type_conversion (WANT_ARITH | WANT_ENUM, arg, true)))
3786 errstring = "wrong type argument to abs";
3787 else if (!noconvert)
3788 arg = default_conversion (arg);
3792 /* Conjugating a real value is a no-op, but allow it anyway. */
3793 if (!(arg = build_expr_type_conversion (WANT_ARITH | WANT_ENUM, arg, true)))
3794 errstring = "wrong type argument to conjugation";
3795 else if (!noconvert)
3796 arg = default_conversion (arg);
3799 case TRUTH_NOT_EXPR:
3800 arg = perform_implicit_conversion (boolean_type_node, arg);
3801 val = invert_truthvalue (arg);
3802 if (arg != error_mark_node)
3804 errstring = "in argument to unary !";
3811 if (TREE_CODE (arg) == COMPLEX_CST)
3812 return TREE_REALPART (arg);
3813 else if (TREE_CODE (TREE_TYPE (arg)) == COMPLEX_TYPE)
3815 arg = build1 (REALPART_EXPR, TREE_TYPE (TREE_TYPE (arg)), arg);
3816 return fold_if_not_in_template (arg);
3822 if (TREE_CODE (arg) == COMPLEX_CST)
3823 return TREE_IMAGPART (arg);
3824 else if (TREE_CODE (TREE_TYPE (arg)) == COMPLEX_TYPE)
3826 arg = build1 (IMAGPART_EXPR, TREE_TYPE (TREE_TYPE (arg)), arg);
3827 return fold_if_not_in_template (arg);
3830 return cp_convert (TREE_TYPE (arg), integer_zero_node);
3832 case PREINCREMENT_EXPR:
3833 case POSTINCREMENT_EXPR:
3834 case PREDECREMENT_EXPR:
3835 case POSTDECREMENT_EXPR:
3836 /* Handle complex lvalues (when permitted)
3837 by reduction to simpler cases. */
3839 val = unary_complex_lvalue (code, arg);
3843 /* Increment or decrement the real part of the value,
3844 and don't change the imaginary part. */
3845 if (TREE_CODE (TREE_TYPE (arg)) == COMPLEX_TYPE)
3849 arg = stabilize_reference (arg);
3850 real = build_unary_op (REALPART_EXPR, arg, 1);
3851 imag = build_unary_op (IMAGPART_EXPR, arg, 1);
3852 return build2 (COMPLEX_EXPR, TREE_TYPE (arg),
3853 build_unary_op (code, real, 1), imag);
3856 /* Report invalid types. */
3858 if (!(arg = build_expr_type_conversion (WANT_ARITH | WANT_POINTER,
3861 if (code == PREINCREMENT_EXPR)
3862 errstring ="no pre-increment operator for type";
3863 else if (code == POSTINCREMENT_EXPR)
3864 errstring ="no post-increment operator for type";
3865 else if (code == PREDECREMENT_EXPR)
3866 errstring ="no pre-decrement operator for type";
3868 errstring ="no post-decrement operator for type";
3872 /* Report something read-only. */
3874 if (CP_TYPE_CONST_P (TREE_TYPE (arg))
3875 || TREE_READONLY (arg))
3876 readonly_error (arg, ((code == PREINCREMENT_EXPR
3877 || code == POSTINCREMENT_EXPR)
3878 ? "increment" : "decrement"),
3883 tree result_type = TREE_TYPE (arg);
3885 arg = get_unwidened (arg, 0);
3886 argtype = TREE_TYPE (arg);
3888 /* ARM $5.2.5 last annotation says this should be forbidden. */
3889 if (TREE_CODE (argtype) == ENUMERAL_TYPE)
3890 pedwarn ("ISO C++ forbids %sing an enum",
3891 (code == PREINCREMENT_EXPR || code == POSTINCREMENT_EXPR)
3892 ? "increment" : "decrement");
3894 /* Compute the increment. */
3896 if (TREE_CODE (argtype) == POINTER_TYPE)
3898 tree type = complete_type (TREE_TYPE (argtype));
3900 if (!COMPLETE_OR_VOID_TYPE_P (type))
3901 error ("cannot %s a pointer to incomplete type %qT",
3902 ((code == PREINCREMENT_EXPR
3903 || code == POSTINCREMENT_EXPR)
3904 ? "increment" : "decrement"), TREE_TYPE (argtype));
3905 else if ((pedantic || warn_pointer_arith)
3906 && !TYPE_PTROB_P (argtype))
3907 pedwarn ("ISO C++ forbids %sing a pointer of type %qT",
3908 ((code == PREINCREMENT_EXPR
3909 || code == POSTINCREMENT_EXPR)
3910 ? "increment" : "decrement"), argtype);
3911 inc = cxx_sizeof_nowarn (TREE_TYPE (argtype));
3914 inc = integer_one_node;
3916 inc = cp_convert (argtype, inc);
3918 /* Handle incrementing a cast-expression. */
3920 switch (TREE_CODE (arg))
3925 case FIX_TRUNC_EXPR:
3926 case FIX_FLOOR_EXPR:
3927 case FIX_ROUND_EXPR:
3930 tree incremented, modify, value, compound;
3931 if (! lvalue_p (arg) && pedantic)
3932 pedwarn ("cast to non-reference type used as lvalue");
3933 arg = stabilize_reference (arg);
3934 if (code == PREINCREMENT_EXPR || code == PREDECREMENT_EXPR)
3937 value = save_expr (arg);
3938 incremented = build2 (((code == PREINCREMENT_EXPR
3939 || code == POSTINCREMENT_EXPR)
3940 ? PLUS_EXPR : MINUS_EXPR),
3941 argtype, value, inc);
3943 modify = build_modify_expr (arg, NOP_EXPR, incremented);
3944 compound = build2 (COMPOUND_EXPR, TREE_TYPE (arg),
3947 /* Eliminate warning about unused result of + or -. */
3948 TREE_NO_WARNING (compound) = 1;
3956 /* Complain about anything else that is not a true lvalue. */
3957 if (!lvalue_or_else (arg, ((code == PREINCREMENT_EXPR
3958 || code == POSTINCREMENT_EXPR)
3959 ? lv_increment : lv_decrement)))
3960 return error_mark_node;
3962 /* Forbid using -- on `bool'. */
3963 if (TREE_TYPE (arg) == boolean_type_node)
3965 if (code == POSTDECREMENT_EXPR || code == PREDECREMENT_EXPR)
3967 error ("invalid use of %<--%> on bool variable %qD", arg);
3968 return error_mark_node;
3970 val = boolean_increment (code, arg);
3973 val = build2 (code, TREE_TYPE (arg), arg, inc);
3975 TREE_SIDE_EFFECTS (val) = 1;
3976 return cp_convert (result_type, val);
3980 /* Note that this operation never does default_conversion
3981 regardless of NOCONVERT. */
3983 argtype = lvalue_type (arg);
3985 if (TREE_CODE (arg) == OFFSET_REF)
3988 if (TREE_CODE (argtype) == REFERENCE_TYPE)
3990 tree type = build_pointer_type (TREE_TYPE (argtype));
3991 arg = build1 (CONVERT_EXPR, type, arg);
3994 else if (pedantic && DECL_MAIN_P (arg))
3996 pedwarn ("ISO C++ forbids taking address of function %<::main%>");
3998 /* Let &* cancel out to simplify resulting code. */
3999 if (TREE_CODE (arg) == INDIRECT_REF)
4001 /* We don't need to have `current_class_ptr' wrapped in a
4002 NON_LVALUE_EXPR node. */
4003 if (arg == current_class_ref)
4004 return current_class_ptr;
4006 arg = TREE_OPERAND (arg, 0);
4007 if (TREE_CODE (TREE_TYPE (arg)) == REFERENCE_TYPE)
4009 tree type = build_pointer_type (TREE_TYPE (TREE_TYPE (arg)));
4010 arg = build1 (CONVERT_EXPR, type, arg);
4012 else if (lvalue_p (arg))
4013 /* Don't let this be an lvalue. */
4014 return non_lvalue (arg);
4018 /* Uninstantiated types are all functions. Taking the
4019 address of a function is a no-op, so just return the
4022 gcc_assert (TREE_CODE (arg) != IDENTIFIER_NODE
4023 || !IDENTIFIER_OPNAME_P (arg));
4025 if (TREE_CODE (arg) == COMPONENT_REF && type_unknown_p (arg)
4026 && !really_overloaded_fn (TREE_OPERAND (arg, 1)))
4028 /* They're trying to take the address of a unique non-static
4029 member function. This is ill-formed (except in MS-land),
4030 but let's try to DTRT.
4031 Note: We only handle unique functions here because we don't
4032 want to complain if there's a static overload; non-unique
4033 cases will be handled by instantiate_type. But we need to
4034 handle this case here to allow casts on the resulting PMF.
4035 We could defer this in non-MS mode, but it's easier to give
4036 a useful error here. */
4038 /* Inside constant member functions, the `this' pointer
4039 contains an extra const qualifier. TYPE_MAIN_VARIANT
4040 is used here to remove this const from the diagnostics
4041 and the created OFFSET_REF. */
4042 tree base = TYPE_MAIN_VARIANT (TREE_TYPE (TREE_OPERAND (arg, 0)));
4043 tree name = DECL_NAME (get_first_fn (TREE_OPERAND (arg, 1)));
4045 if (! flag_ms_extensions)
4047 if (current_class_type
4048 && TREE_OPERAND (arg, 0) == current_class_ref)
4049 /* An expression like &memfn. */
4050 pedwarn ("ISO C++ forbids taking the address of an unqualified"
4051 " or parenthesized non-static member function to form"
4052 " a pointer to member function. Say %<&%T::%D%>",
4055 pedwarn ("ISO C++ forbids taking the address of a bound member"
4056 " function to form a pointer to member function."
4060 arg = build_offset_ref (base, name, /*address_p=*/true);
4064 if (type_unknown_p (arg))
4065 return build1 (ADDR_EXPR, unknown_type_node, arg);
4067 /* Handle complex lvalues (when permitted)
4068 by reduction to simpler cases. */
4069 val = unary_complex_lvalue (code, arg);
4073 switch (TREE_CODE (arg))
4078 case FIX_TRUNC_EXPR:
4079 case FIX_FLOOR_EXPR:
4080 case FIX_ROUND_EXPR:
4082 if (! lvalue_p (arg) && pedantic)
4083 pedwarn ("ISO C++ forbids taking the address of a cast to a non-lvalue expression");
4087 arg = OVL_CURRENT (arg);
4094 /* Allow the address of a constructor if all the elements
4096 if (TREE_CODE (arg) == CONSTRUCTOR && TREE_HAS_CONSTRUCTOR (arg)
4097 && TREE_CONSTANT (arg))
4099 /* Anything not already handled and not a true memory reference
4101 else if (TREE_CODE (argtype) != FUNCTION_TYPE
4102 && TREE_CODE (argtype) != METHOD_TYPE
4103 && !lvalue_or_else (arg, lv_addressof))
4104 return error_mark_node;
4106 if (argtype != error_mark_node)
4107 argtype = build_pointer_type (argtype);
4112 if (TREE_CODE (arg) != COMPONENT_REF
4113 /* Inside a template, we are processing a non-dependent
4114 expression so we can just form an ADDR_EXPR with the
4116 || processing_template_decl)
4117 addr = build_address (arg);
4118 else if (TREE_CODE (TREE_OPERAND (arg, 1)) == BASELINK)
4120 tree fn = BASELINK_FUNCTIONS (TREE_OPERAND (arg, 1));
4122 /* We can only get here with a single static member
4124 gcc_assert (TREE_CODE (fn) == FUNCTION_DECL
4125 && DECL_STATIC_FUNCTION_P (fn));
4127 addr = build_address (fn);
4128 if (TREE_SIDE_EFFECTS (TREE_OPERAND (arg, 0)))
4129 /* Do not lose object's side effects. */
4130 addr = build2 (COMPOUND_EXPR, TREE_TYPE (addr),
4131 TREE_OPERAND (arg, 0), addr);
4133 else if (DECL_C_BIT_FIELD (TREE_OPERAND (arg, 1)))
4135 error ("attempt to take address of bit-field structure member %qD",
4136 TREE_OPERAND (arg, 1));
4137 return error_mark_node;
4141 tree field = TREE_OPERAND (arg, 1);
4142 tree rval = build_unary_op (ADDR_EXPR, TREE_OPERAND (arg, 0), 0);
4143 tree binfo = lookup_base (TREE_TYPE (TREE_TYPE (rval)),
4144 decl_type_context (field),
4147 rval = build_base_path (PLUS_EXPR, rval, binfo, 1);
4149 TREE_OPERAND (arg, 0) = build_indirect_ref (rval, NULL);
4150 addr = build_address (arg);
4153 if (TREE_CODE (argtype) == POINTER_TYPE
4154 && TREE_CODE (TREE_TYPE (argtype)) == METHOD_TYPE)
4156 build_ptrmemfunc_type (argtype);
4157 addr = build_ptrmemfunc (argtype, addr, 0,
4158 /*c_cast_p=*/false);
4171 argtype = TREE_TYPE (arg);
4172 return fold_if_not_in_template (build1 (code, argtype, arg));
4175 error ("%s", errstring);
4176 return error_mark_node;
4179 /* Apply unary lvalue-demanding operator CODE to the expression ARG
4180 for certain kinds of expressions which are not really lvalues
4181 but which we can accept as lvalues.
4183 If ARG is not a kind of expression we can handle, return zero. */
4186 unary_complex_lvalue (enum tree_code code, tree arg)
4188 /* Handle (a, b) used as an "lvalue". */
4189 if (TREE_CODE (arg) == COMPOUND_EXPR)
4191 tree real_result = build_unary_op (code, TREE_OPERAND (arg, 1), 0);
4192 return build2 (COMPOUND_EXPR, TREE_TYPE (real_result),
4193 TREE_OPERAND (arg, 0), real_result);
4196 /* Handle (a ? b : c) used as an "lvalue". */
4197 if (TREE_CODE (arg) == COND_EXPR
4198 || TREE_CODE (arg) == MIN_EXPR || TREE_CODE (arg) == MAX_EXPR)
4199 return rationalize_conditional_expr (code, arg);
4201 /* Handle (a = b), (++a), and (--a) used as an "lvalue". */
4202 if (TREE_CODE (arg) == MODIFY_EXPR
4203 || TREE_CODE (arg) == PREINCREMENT_EXPR
4204 || TREE_CODE (arg) == PREDECREMENT_EXPR)
4206 tree lvalue = TREE_OPERAND (arg, 0);
4207 if (TREE_SIDE_EFFECTS (lvalue))
4209 lvalue = stabilize_reference (lvalue);
4210 arg = build2 (TREE_CODE (arg), TREE_TYPE (arg),
4211 lvalue, TREE_OPERAND (arg, 1));
4213 return unary_complex_lvalue
4214 (code, build2 (COMPOUND_EXPR, TREE_TYPE (lvalue), arg, lvalue));
4217 if (code != ADDR_EXPR)
4220 /* Handle (a = b) used as an "lvalue" for `&'. */
4221 if (TREE_CODE (arg) == MODIFY_EXPR
4222 || TREE_CODE (arg) == INIT_EXPR)
4224 tree real_result = build_unary_op (code, TREE_OPERAND (arg, 0), 0);
4225 arg = build2 (COMPOUND_EXPR, TREE_TYPE (real_result),
4227 TREE_NO_WARNING (arg) = 1;
4231 if (TREE_CODE (TREE_TYPE (arg)) == FUNCTION_TYPE
4232 || TREE_CODE (TREE_TYPE (arg)) == METHOD_TYPE
4233 || TREE_CODE (arg) == OFFSET_REF)
4237 gcc_assert (TREE_CODE (arg) != SCOPE_REF);
4239 if (TREE_CODE (arg) != OFFSET_REF)
4242 t = TREE_OPERAND (arg, 1);
4244 /* Check all this code for right semantics. */
4245 if (TREE_CODE (t) == FUNCTION_DECL)
4247 if (DECL_DESTRUCTOR_P (t))
4248 error ("taking address of destructor");
4249 return build_unary_op (ADDR_EXPR, t, 0);
4251 if (TREE_CODE (t) == VAR_DECL)
4252 return build_unary_op (ADDR_EXPR, t, 0);
4257 if (TREE_OPERAND (arg, 0)
4258 && ! is_dummy_object (TREE_OPERAND (arg, 0))
4259 && TREE_CODE (t) != FIELD_DECL)
4261 error ("taking address of bound pointer-to-member expression");
4262 return error_mark_node;
4264 if (!PTRMEM_OK_P (arg))
4265 return build_unary_op (code, arg, 0);
4267 if (TREE_CODE (TREE_TYPE (t)) == REFERENCE_TYPE)
4269 error ("cannot create pointer to reference member %qD", t);
4270 return error_mark_node;
4273 type = build_ptrmem_type (context_for_name_lookup (t),
4275 t = make_ptrmem_cst (type, TREE_OPERAND (arg, 1));
4281 /* We permit compiler to make function calls returning
4282 objects of aggregate type look like lvalues. */
4286 if (TREE_CODE (targ) == SAVE_EXPR)
4287 targ = TREE_OPERAND (targ, 0);
4289 if (TREE_CODE (targ) == CALL_EXPR && IS_AGGR_TYPE (TREE_TYPE (targ)))
4291 if (TREE_CODE (arg) == SAVE_EXPR)
4294 targ = build_cplus_new (TREE_TYPE (arg), arg);
4295 return build1 (ADDR_EXPR, build_pointer_type (TREE_TYPE (arg)), targ);
4298 if (TREE_CODE (arg) == SAVE_EXPR && TREE_CODE (targ) == INDIRECT_REF)
4299 return build3 (SAVE_EXPR, build_pointer_type (TREE_TYPE (arg)),
4300 TREE_OPERAND (targ, 0), current_function_decl, NULL);
4303 /* Don't let anything else be handled specially. */
4307 /* Mark EXP saying that we need to be able to take the
4308 address of it; it should not be allocated in a register.
4309 Value is true if successful.
4311 C++: we do not allow `current_class_ptr' to be addressable. */
4314 cxx_mark_addressable (tree exp)
4319 switch (TREE_CODE (x))
4326 x = TREE_OPERAND (x, 0);
4330 if (x == current_class_ptr)
4332 error ("cannot take the address of %<this%>, which is an rvalue expression");
4333 TREE_ADDRESSABLE (x) = 1; /* so compiler doesn't die later. */
4339 /* Caller should not be trying to mark initialized
4340 constant fields addressable. */
4341 gcc_assert (DECL_LANG_SPECIFIC (x) == 0
4342 || DECL_IN_AGGR_P (x) == 0
4344 || DECL_EXTERNAL (x));
4349 if (DECL_REGISTER (x) && !TREE_ADDRESSABLE (x)
4350 && !DECL_ARTIFICIAL (x))
4352 if (DECL_HARD_REGISTER (x) != 0)
4355 ("address of explicit register variable %qD requested", x);
4358 else if (extra_warnings)
4360 ("address requested for %qD, which is declared %<register%>", x);
4362 TREE_ADDRESSABLE (x) = 1;
4366 TREE_ADDRESSABLE (x) = 1;
4370 TREE_ADDRESSABLE (x) = 1;
4374 TREE_ADDRESSABLE (x) = 1;
4375 cxx_mark_addressable (TREE_OPERAND (x, 0));
4383 /* Build and return a conditional expression IFEXP ? OP1 : OP2. */
4386 build_x_conditional_expr (tree ifexp, tree op1, tree op2)
4388 tree orig_ifexp = ifexp;
4389 tree orig_op1 = op1;
4390 tree orig_op2 = op2;
4393 if (processing_template_decl)
4395 /* The standard says that the expression is type-dependent if
4396 IFEXP is type-dependent, even though the eventual type of the
4397 expression doesn't dependent on IFEXP. */
4398 if (type_dependent_expression_p (ifexp)
4399 /* As a GNU extension, the middle operand may be omitted. */
4400 || (op1 && type_dependent_expression_p (op1))
4401 || type_dependent_expression_p (op2))
4402 return build_min_nt (COND_EXPR, ifexp, op1, op2);
4403 ifexp = build_non_dependent_expr (ifexp);
4405 op1 = build_non_dependent_expr (op1);
4406 op2 = build_non_dependent_expr (op2);
4409 expr = build_conditional_expr (ifexp, op1, op2);
4410 if (processing_template_decl && expr != error_mark_node)
4411 return build_min_non_dep (COND_EXPR, expr,
4412 orig_ifexp, orig_op1, orig_op2);
4416 /* Given a list of expressions, return a compound expression
4417 that performs them all and returns the value of the last of them. */
4419 tree build_x_compound_expr_from_list (tree list, const char *msg)
4421 tree expr = TREE_VALUE (list);
4423 if (TREE_CHAIN (list))
4426 pedwarn ("%s expression list treated as compound expression", msg);
4428 for (list = TREE_CHAIN (list); list; list = TREE_CHAIN (list))
4429 expr = build_x_compound_expr (expr, TREE_VALUE (list));
4435 /* Handle overloading of the ',' operator when needed. */
4438 build_x_compound_expr (tree op1, tree op2)
4441 tree orig_op1 = op1;
4442 tree orig_op2 = op2;
4444 if (processing_template_decl)
4446 if (type_dependent_expression_p (op1)
4447 || type_dependent_expression_p (op2))
4448 return build_min_nt (COMPOUND_EXPR, op1, op2);
4449 op1 = build_non_dependent_expr (op1);
4450 op2 = build_non_dependent_expr (op2);
4453 result = build_new_op (COMPOUND_EXPR, LOOKUP_NORMAL, op1, op2, NULL_TREE,
4454 /*overloaded_p=*/NULL);
4456 result = build_compound_expr (op1, op2);
4458 if (processing_template_decl && result != error_mark_node)
4459 return build_min_non_dep (COMPOUND_EXPR, result, orig_op1, orig_op2);
4464 /* Build a compound expression. */
4467 build_compound_expr (tree lhs, tree rhs)
4469 lhs = decl_constant_value (lhs);
4470 lhs = convert_to_void (lhs, "left-hand operand of comma");
4472 if (lhs == error_mark_node || rhs == error_mark_node)
4473 return error_mark_node;
4475 if (TREE_CODE (rhs) == TARGET_EXPR)
4477 /* If the rhs is a TARGET_EXPR, then build the compound
4478 expression inside the target_expr's initializer. This
4479 helps the compiler to eliminate unnecessary temporaries. */
4480 tree init = TREE_OPERAND (rhs, 1);
4482 init = build2 (COMPOUND_EXPR, TREE_TYPE (init), lhs, init);
4483 TREE_OPERAND (rhs, 1) = init;
4488 return build2 (COMPOUND_EXPR, TREE_TYPE (rhs), lhs, rhs);
4491 /* Issue a diagnostic message if casting from SRC_TYPE to DEST_TYPE
4492 casts away constness. DIAG_FN gives the function to call if we
4493 need to issue a diagnostic; if it is NULL, no diagnostic will be
4494 issued. DESCRIPTION explains what operation is taking place. */
4497 check_for_casting_away_constness (tree src_type, tree dest_type,
4498 void (*diag_fn)(const char *, ...),
4499 const char *description)
4501 if (diag_fn && casts_away_constness (src_type, dest_type))
4502 error ("%s from type %qT to type %qT casts away constness",
4503 description, src_type, dest_type);
4506 /* Convert EXPR (an expression with pointer-to-member type) to TYPE
4507 (another pointer-to-member type in the same hierarchy) and return
4508 the converted expression. If ALLOW_INVERSE_P is permitted, a
4509 pointer-to-derived may be converted to pointer-to-base; otherwise,
4510 only the other direction is permitted. If C_CAST_P is true, this
4511 conversion is taking place as part of a C-style cast. */
4514 convert_ptrmem (tree type, tree expr, bool allow_inverse_p,
4517 if (TYPE_PTRMEM_P (type))
4521 if (TREE_CODE (expr) == PTRMEM_CST)
4522 expr = cplus_expand_constant (expr);
4523 delta = get_delta_difference (TYPE_PTRMEM_CLASS_TYPE (TREE_TYPE (expr)),
4524 TYPE_PTRMEM_CLASS_TYPE (type),
4527 if (!integer_zerop (delta))
4528 expr = cp_build_binary_op (PLUS_EXPR,
4529 build_nop (ptrdiff_type_node, expr),
4531 return build_nop (type, expr);
4534 return build_ptrmemfunc (TYPE_PTRMEMFUNC_FN_TYPE (type), expr,
4535 allow_inverse_p, c_cast_p);
4538 /* Perform a static_cast from EXPR to TYPE. When C_CAST_P is true,
4539 this static_cast is being attempted as one of the possible casts
4540 allowed by a C-style cast. (In that case, accessibility of base
4541 classes is not considered, and it is OK to cast away
4542 constness.) Return the result of the cast. *VALID_P is set to
4543 indicate whether or not the cast was valid. */
4546 build_static_cast_1 (tree type, tree expr, bool c_cast_p,
4552 void (*diag_fn)(const char*, ...);
4555 /* Assume the cast is valid. */
4558 intype = TREE_TYPE (expr);
4560 /* Determine what to do when casting away constness. */
4563 /* C-style casts are allowed to cast away constness. With
4564 WARN_CAST_QUAL, we still want to issue a warning. */
4565 diag_fn = warn_cast_qual ? warning : NULL;
4570 /* A static_cast may not cast away constness. */
4572 desc = "static_cast";
4575 /* [expr.static.cast]
4577 An lvalue of type "cv1 B", where B is a class type, can be cast
4578 to type "reference to cv2 D", where D is a class derived (clause
4579 _class.derived_) from B, if a valid standard conversion from
4580 "pointer to D" to "pointer to B" exists (_conv.ptr_), cv2 is the
4581 same cv-qualification as, or greater cv-qualification than, cv1,
4582 and B is not a virtual base class of D. */
4583 /* We check this case before checking the validity of "TYPE t =
4584 EXPR;" below because for this case:
4587 struct D : public B { D(const B&); };
4589 void f() { static_cast<const D&>(b); }
4591 we want to avoid constructing a new D. The standard is not
4592 completely clear about this issue, but our interpretation is
4593 consistent with other compilers. */
4594 if (TREE_CODE (type) == REFERENCE_TYPE
4595 && CLASS_TYPE_P (TREE_TYPE (type))
4596 && CLASS_TYPE_P (intype)
4597 && real_lvalue_p (expr)
4598 && DERIVED_FROM_P (intype, TREE_TYPE (type))
4599 && can_convert (build_pointer_type (TYPE_MAIN_VARIANT (intype)),
4600 build_pointer_type (TYPE_MAIN_VARIANT
4601 (TREE_TYPE (type))))
4603 || at_least_as_qualified_p (TREE_TYPE (type), intype)))
4607 /* There is a standard conversion from "D*" to "B*" even if "B"
4608 is ambiguous or inaccessible. If this is really a
4609 static_cast, then we check both for inaccessibility and
4610 ambiguity. However, if this is a static_cast being performed
4611 because the user wrote a C-style cast, then accessibility is
4613 base = lookup_base (TREE_TYPE (type), intype,
4614 c_cast_p ? ba_unique : ba_check,
4617 /* Convert from "B*" to "D*". This function will check that "B"
4618 is not a virtual base of "D". */
4619 expr = build_base_path (MINUS_EXPR, build_address (expr),
4620 base, /*nonnull=*/false);
4621 /* Convert the pointer to a reference -- but then remember that
4622 there are no expressions with reference type in C++. */
4623 return convert_from_reference (build_nop (type, expr));
4628 /* [expr.static.cast]
4630 An expression e can be explicitly converted to a type T using a
4631 static_cast of the form static_cast<T>(e) if the declaration T
4632 t(e);" is well-formed, for some invented temporary variable
4634 result = perform_direct_initialization_if_possible (type, expr,
4638 result = convert_from_reference (result);
4640 /* Ignore any integer overflow caused by the cast. */
4641 if (TREE_CODE (result) == INTEGER_CST
4642 && CONSTANT_CLASS_P (orig))
4644 TREE_OVERFLOW (result) = TREE_OVERFLOW (orig);
4645 TREE_CONSTANT_OVERFLOW (result)
4646 = TREE_CONSTANT_OVERFLOW (orig);
4648 /* [expr.static.cast]
4650 If T is a reference type, the result is an lvalue; otherwise,
4651 the result is an rvalue. */
4652 if (TREE_CODE (type) != REFERENCE_TYPE
4653 && real_lvalue_p (result))
4654 result = build1 (NON_LVALUE_EXPR, TREE_TYPE (result), result);
4658 /* [expr.static.cast]
4660 Any expression can be explicitly converted to type cv void. */
4661 if (TREE_CODE (type) == VOID_TYPE)
4662 return convert_to_void (expr, /*implicit=*/NULL);
4664 /* [expr.static.cast]
4666 The inverse of any standard conversion sequence (clause _conv_),
4667 other than the lvalue-to-rvalue (_conv.lval_), array-to-pointer
4668 (_conv.array_), function-to-pointer (_conv.func_), and boolean
4669 (_conv.bool_) conversions, can be performed explicitly using
4670 static_cast subject to the restriction that the explicit
4671 conversion does not cast away constness (_expr.const.cast_), and
4672 the following additional rules for specific cases: */
4673 /* For reference, the conversions not excluded are: integral
4674 promotions, floating point promotion, integral conversions,
4675 floating point conversions, floating-integral conversions,
4676 pointer conversions, and pointer to member conversions. */
4677 if ((ARITHMETIC_TYPE_P (type) && ARITHMETIC_TYPE_P (intype))
4680 A value of integral _or enumeration_ type can be explicitly
4681 converted to an enumeration type. */
4682 || (INTEGRAL_OR_ENUMERATION_TYPE_P (type)
4683 && INTEGRAL_OR_ENUMERATION_TYPE_P (intype)))
4685 expr = decl_constant_value (expr);
4686 expr = ocp_convert (type, expr, CONV_C_CAST, LOOKUP_NORMAL);
4688 /* Ignore any integer overflow caused by the cast. */
4689 if (TREE_CODE (expr) == INTEGER_CST
4690 && CONSTANT_CLASS_P (orig))
4692 TREE_OVERFLOW (expr) = TREE_OVERFLOW (orig);
4693 TREE_CONSTANT_OVERFLOW (expr) = TREE_CONSTANT_OVERFLOW (orig);
4698 if (TYPE_PTR_P (type) && TYPE_PTR_P (intype)
4699 && CLASS_TYPE_P (TREE_TYPE (type))
4700 && CLASS_TYPE_P (TREE_TYPE (intype))
4701 && can_convert (build_pointer_type (TYPE_MAIN_VARIANT
4702 (TREE_TYPE (intype))),
4703 build_pointer_type (TYPE_MAIN_VARIANT
4704 (TREE_TYPE (type)))))
4709 check_for_casting_away_constness (intype, type, diag_fn, desc);
4710 base = lookup_base (TREE_TYPE (type), TREE_TYPE (intype),
4711 c_cast_p ? ba_unique : ba_check,
4713 return build_base_path (MINUS_EXPR, expr, base, /*nonnull=*/false);
4716 if ((TYPE_PTRMEM_P (type) && TYPE_PTRMEM_P (intype))
4717 || (TYPE_PTRMEMFUNC_P (type) && TYPE_PTRMEMFUNC_P (intype)))
4724 c1 = TYPE_PTRMEM_CLASS_TYPE (intype);
4725 c2 = TYPE_PTRMEM_CLASS_TYPE (type);
4727 if (TYPE_PTRMEM_P (type))
4729 t1 = (build_ptrmem_type
4731 TYPE_MAIN_VARIANT (TYPE_PTRMEM_POINTED_TO_TYPE (intype))));
4732 t2 = (build_ptrmem_type
4734 TYPE_MAIN_VARIANT (TYPE_PTRMEM_POINTED_TO_TYPE (type))));
4741 if (can_convert (t1, t2))
4744 check_for_casting_away_constness (intype, type, diag_fn,
4746 return convert_ptrmem (type, expr, /*allow_inverse_p=*/1,
4751 /* [expr.static.cast]
4753 An rvalue of type "pointer to cv void" can be explicitly
4754 converted to a pointer to object type. A value of type pointer
4755 to object converted to "pointer to cv void" and back to the
4756 original pointer type will have its original value. */
4757 if (TREE_CODE (intype) == POINTER_TYPE
4758 && VOID_TYPE_P (TREE_TYPE (intype))
4759 && TYPE_PTROB_P (type))
4762 check_for_casting_away_constness (intype, type, diag_fn, desc);
4763 return build_nop (type, expr);
4767 return error_mark_node;
4770 /* Return an expression representing static_cast<TYPE>(EXPR). */
4773 build_static_cast (tree type, tree expr)
4778 if (type == error_mark_node || expr == error_mark_node)
4779 return error_mark_node;
4781 if (processing_template_decl)
4783 expr = build_min (STATIC_CAST_EXPR, type, expr);
4784 /* We don't know if it will or will not have side effects. */
4785 TREE_SIDE_EFFECTS (expr) = 1;
4789 /* build_c_cast puts on a NOP_EXPR to make the result not an lvalue.
4790 Strip such NOP_EXPRs if VALUE is being used in non-lvalue context. */
4791 if (TREE_CODE (type) != REFERENCE_TYPE
4792 && TREE_CODE (expr) == NOP_EXPR
4793 && TREE_TYPE (expr) == TREE_TYPE (TREE_OPERAND (expr, 0)))
4794 expr = TREE_OPERAND (expr, 0);
4796 result = build_static_cast_1 (type, expr, /*c_cast_p=*/false, &valid_p);
4800 error ("invalid static_cast from type %qT to type %qT",
4801 TREE_TYPE (expr), type);
4802 return error_mark_node;
4805 /* EXPR is an expression with member function or pointer-to-member
4806 function type. TYPE is a pointer type. Converting EXPR to TYPE is
4807 not permitted by ISO C++, but we accept it in some modes. If we
4808 are not in one of those modes, issue a diagnostic. Return the
4809 converted expression. */
4812 convert_member_func_to_ptr (tree type, tree expr)
4817 intype = TREE_TYPE (expr);
4818 gcc_assert (TYPE_PTRMEMFUNC_P (intype)
4819 || TREE_CODE (intype) == METHOD_TYPE);
4821 if (pedantic || warn_pmf2ptr)
4822 pedwarn ("converting from %qT to %qT", intype, type);
4824 if (TREE_CODE (intype) == METHOD_TYPE)
4825 expr = build_addr_func (expr);
4826 else if (TREE_CODE (expr) == PTRMEM_CST)
4827 expr = build_address (PTRMEM_CST_MEMBER (expr));
4830 decl = maybe_dummy_object (TYPE_PTRMEM_CLASS_TYPE (intype), 0);
4831 decl = build_address (decl);
4832 expr = get_member_function_from_ptrfunc (&decl, expr);
4835 return build_nop (type, expr);
4838 /* Return a representation for a reinterpret_cast from EXPR to TYPE.
4839 If C_CAST_P is true, this reinterpret cast is being done as part of
4840 a C-style cast. If VALID_P is non-NULL, *VALID_P is set to
4841 indicate whether or not reinterpret_cast was valid. */
4844 build_reinterpret_cast_1 (tree type, tree expr, bool c_cast_p,
4849 /* Assume the cast is invalid. */
4853 if (type == error_mark_node || error_operand_p (expr))
4854 return error_mark_node;
4856 intype = TREE_TYPE (expr);
4858 /* [expr.reinterpret.cast]
4859 An lvalue expression of type T1 can be cast to the type
4860 "reference to T2" if an expression of type "pointer to T1" can be
4861 explicitly converted to the type "pointer to T2" using a
4862 reinterpret_cast. */
4863 if (TREE_CODE (type) == REFERENCE_TYPE)
4865 if (! real_lvalue_p (expr))
4867 error ("invalid cast of an rvalue expression of type "
4870 return error_mark_node;
4873 /* Warn about a reinterpret_cast from "A*" to "B&" if "A" and
4874 "B" are related class types; the reinterpret_cast does not
4875 adjust the pointer. */
4876 if (TYPE_PTR_P (intype)
4877 && (comptypes (TREE_TYPE (intype), TREE_TYPE (type),
4878 COMPARE_BASE | COMPARE_DERIVED)))
4879 warning ("casting %qT to %qT does not dereference pointer",
4882 expr = build_unary_op (ADDR_EXPR, expr, 0);
4883 if (expr != error_mark_node)
4884 expr = build_reinterpret_cast_1
4885 (build_pointer_type (TREE_TYPE (type)), expr, c_cast_p,
4887 if (expr != error_mark_node)
4888 expr = build_indirect_ref (expr, 0);
4892 /* As a G++ extension, we consider conversions from member
4893 functions, and pointers to member functions to
4894 pointer-to-function and pointer-to-void types. If
4895 -Wno-pmf-conversions has not been specified,
4896 convert_member_func_to_ptr will issue an error message. */
4897 if ((TYPE_PTRMEMFUNC_P (intype)
4898 || TREE_CODE (intype) == METHOD_TYPE)
4899 && TYPE_PTR_P (type)
4900 && (TREE_CODE (TREE_TYPE (type)) == FUNCTION_TYPE
4901 || VOID_TYPE_P (TREE_TYPE (type))))
4902 return convert_member_func_to_ptr (type, expr);
4904 /* If the cast is not to a reference type, the lvalue-to-rvalue,
4905 array-to-pointer, and function-to-pointer conversions are
4907 expr = decay_conversion (expr);
4909 /* build_c_cast puts on a NOP_EXPR to make the result not an lvalue.
4910 Strip such NOP_EXPRs if VALUE is being used in non-lvalue context. */
4911 if (TREE_CODE (expr) == NOP_EXPR
4912 && TREE_TYPE (expr) == TREE_TYPE (TREE_OPERAND (expr, 0)))
4913 expr = TREE_OPERAND (expr, 0);
4915 if (error_operand_p (expr))
4916 return error_mark_node;
4918 intype = TREE_TYPE (expr);
4920 /* [expr.reinterpret.cast]
4921 A pointer can be converted to any integral type large enough to
4923 if (CP_INTEGRAL_TYPE_P (type) && TYPE_PTR_P (intype))
4925 if (TYPE_PRECISION (type) < TYPE_PRECISION (intype))
4926 pedwarn ("cast from %qT to %qT loses precision",
4929 /* [expr.reinterpret.cast]
4930 A value of integral or enumeration type can be explicitly
4931 converted to a pointer. */
4932 else if (TYPE_PTR_P (type) && INTEGRAL_OR_ENUMERATION_TYPE_P (intype))
4935 else if ((TYPE_PTRFN_P (type) && TYPE_PTRFN_P (intype))
4936 || (TYPE_PTRMEMFUNC_P (type) && TYPE_PTRMEMFUNC_P (intype)))
4938 expr = decl_constant_value (expr);
4939 return fold_if_not_in_template (build_nop (type, expr));
4941 else if ((TYPE_PTRMEM_P (type) && TYPE_PTRMEM_P (intype))
4942 || (TYPE_PTROBV_P (type) && TYPE_PTROBV_P (intype)))
4945 check_for_casting_away_constness (intype, type, error,
4946 "reinterpret_cast");
4947 /* Warn about possible alignment problems. */
4948 if (STRICT_ALIGNMENT && warn_cast_align
4949 && !VOID_TYPE_P (type)
4950 && TREE_CODE (TREE_TYPE (intype)) != FUNCTION_TYPE
4951 && COMPLETE_TYPE_P (TREE_TYPE (type))
4952 && COMPLETE_TYPE_P (TREE_TYPE (intype))
4953 && TYPE_ALIGN (TREE_TYPE (type)) > TYPE_ALIGN (TREE_TYPE (intype)))
4954 warning ("cast from %qT to %qT increases required alignment of "
4957 expr = decl_constant_value (expr);
4958 return fold_if_not_in_template (build_nop (type, expr));
4960 else if ((TYPE_PTRFN_P (type) && TYPE_PTROBV_P (intype))
4961 || (TYPE_PTRFN_P (intype) && TYPE_PTROBV_P (type)))
4964 /* Only issue a warning, as we have always supported this
4965 where possible, and it is necessary in some cases. DR 195
4966 addresses this issue, but as of 2004/10/26 is still in
4968 warning ("ISO C++ forbids casting between pointer-to-function and pointer-to-object");
4970 expr = decl_constant_value (expr);
4971 return fold_if_not_in_template (build_nop (type, expr));
4973 else if (TREE_CODE (type) == VECTOR_TYPE)
4974 return fold_if_not_in_template (convert_to_vector (type, expr));
4979 error ("invalid cast from type %qT to type %qT", intype, type);
4980 return error_mark_node;
4983 return cp_convert (type, expr);
4987 build_reinterpret_cast (tree type, tree expr)
4989 if (type == error_mark_node || expr == error_mark_node)
4990 return error_mark_node;
4992 if (processing_template_decl)
4994 tree t = build_min (REINTERPRET_CAST_EXPR, type, expr);
4996 if (!TREE_SIDE_EFFECTS (t)
4997 && type_dependent_expression_p (expr))
4998 /* There might turn out to be side effects inside expr. */
4999 TREE_SIDE_EFFECTS (t) = 1;
5003 return build_reinterpret_cast_1 (type, expr, /*c_cast_p=*/false,
5007 /* Perform a const_cast from EXPR to TYPE. If the cast is valid,
5008 return an appropriate expression. Otherwise, return
5009 error_mark_node. If the cast is not valid, and COMPLAIN is true,
5010 then a diagnostic will be issued. If VALID_P is non-NULL, its
5011 value upon return will indicate whether or not the conversion
5015 build_const_cast_1 (tree dst_type, tree expr, bool complain,
5019 tree reference_type;
5021 /* Callers are responsible for handling error_mark_node as a
5022 destination type. */
5023 gcc_assert (dst_type != error_mark_node);
5024 /* In a template, callers should be building syntactic
5025 representations of casts, not using this machinery. */
5026 gcc_assert (!processing_template_decl);
5028 /* Assume the conversion is invalid. */
5032 if (!POINTER_TYPE_P (dst_type) && !TYPE_PTRMEM_P (dst_type))
5035 error ("invalid use of const_cast with type %qT, "
5036 "which is not a pointer, "
5037 "reference, nor a pointer-to-data-member type", dst_type);
5038 return error_mark_node;
5041 if (TREE_CODE (TREE_TYPE (dst_type)) == FUNCTION_TYPE)
5044 error ("invalid use of const_cast with type %qT, which is a pointer "
5045 "or reference to a function type", dst_type);
5046 return error_mark_node;
5049 src_type = TREE_TYPE (expr);
5050 /* Expressions do not really have reference types. */
5051 if (TREE_CODE (src_type) == REFERENCE_TYPE)
5052 src_type = TREE_TYPE (src_type);
5054 /* [expr.const.cast]
5056 An lvalue of type T1 can be explicitly converted to an lvalue of
5057 type T2 using the cast const_cast<T2&> (where T1 and T2 are object
5058 types) if a pointer to T1 can be explicitly converted to the type
5059 pointer to T2 using a const_cast. */
5060 if (TREE_CODE (dst_type) == REFERENCE_TYPE)
5062 reference_type = dst_type;
5063 if (! real_lvalue_p (expr))
5066 error ("invalid const_cast of an rvalue of type %qT to type %qT",
5067 src_type, dst_type);
5068 return error_mark_node;
5070 dst_type = build_pointer_type (TREE_TYPE (dst_type));
5071 src_type = build_pointer_type (src_type);
5075 reference_type = NULL_TREE;
5076 /* If the destination type is not a reference type, the
5077 lvalue-to-rvalue, array-to-pointer, and function-to-pointer
5078 conversions are performed. */
5079 src_type = type_decays_to (src_type);
5080 if (src_type == error_mark_node)
5081 return error_mark_node;
5084 if ((TYPE_PTR_P (src_type) || TYPE_PTRMEM_P (src_type))
5085 && comp_ptr_ttypes_const (dst_type, src_type))
5091 expr = build_unary_op (ADDR_EXPR, expr, 0);
5092 expr = build_nop (reference_type, expr);
5093 return convert_from_reference (expr);
5097 expr = decay_conversion (expr);
5098 /* build_c_cast puts on a NOP_EXPR to make the result not an
5099 lvalue. Strip such NOP_EXPRs if VALUE is being used in
5100 non-lvalue context. */
5101 if (TREE_CODE (expr) == NOP_EXPR
5102 && TREE_TYPE (expr) == TREE_TYPE (TREE_OPERAND (expr, 0)))
5103 expr = TREE_OPERAND (expr, 0);
5104 return build_nop (dst_type, expr);
5109 error ("invalid const_cast from type %qT to type %qT",
5110 src_type, dst_type);
5111 return error_mark_node;
5115 build_const_cast (tree type, tree expr)
5117 if (type == error_mark_node || error_operand_p (expr))
5118 return error_mark_node;
5120 if (processing_template_decl)
5122 tree t = build_min (CONST_CAST_EXPR, type, expr);
5124 if (!TREE_SIDE_EFFECTS (t)
5125 && type_dependent_expression_p (expr))
5126 /* There might turn out to be side effects inside expr. */
5127 TREE_SIDE_EFFECTS (t) = 1;
5131 return build_const_cast_1 (type, expr, /*complain=*/true,
5135 /* Build an expression representing an explicit C-style cast to type
5136 TYPE of expression EXPR. */
5139 build_c_cast (tree type, tree expr)
5145 if (type == error_mark_node || error_operand_p (expr))
5146 return error_mark_node;
5148 if (processing_template_decl)
5150 tree t = build_min (CAST_EXPR, type,
5151 tree_cons (NULL_TREE, value, NULL_TREE));
5152 /* We don't know if it will or will not have side effects. */
5153 TREE_SIDE_EFFECTS (t) = 1;
5157 /* Casts to a (pointer to a) specific ObjC class (or 'id' or
5158 'Class') should always be retained, because this information aids
5159 in method lookup. */
5160 if (objc_is_object_ptr (type)
5161 && objc_is_object_ptr (TREE_TYPE (expr)))
5162 return build_nop (type, expr);
5164 /* build_c_cast puts on a NOP_EXPR to make the result not an lvalue.
5165 Strip such NOP_EXPRs if VALUE is being used in non-lvalue context. */
5166 if (TREE_CODE (type) != REFERENCE_TYPE
5167 && TREE_CODE (value) == NOP_EXPR
5168 && TREE_TYPE (value) == TREE_TYPE (TREE_OPERAND (value, 0)))
5169 value = TREE_OPERAND (value, 0);
5171 if (TREE_CODE (type) == ARRAY_TYPE)
5173 /* Allow casting from T1* to T2[] because Cfront allows it.
5174 NIHCL uses it. It is not valid ISO C++ however. */
5175 if (TREE_CODE (TREE_TYPE (expr)) == POINTER_TYPE)
5177 pedwarn ("ISO C++ forbids casting to an array type %qT", type);
5178 type = build_pointer_type (TREE_TYPE (type));
5182 error ("ISO C++ forbids casting to an array type %qT", type);
5183 return error_mark_node;
5187 if (TREE_CODE (type) == FUNCTION_TYPE
5188 || TREE_CODE (type) == METHOD_TYPE)
5190 error ("invalid cast to function type %qT", type);
5191 return error_mark_node;
5194 /* A C-style cast can be a const_cast. */
5195 result = build_const_cast_1 (type, value, /*complain=*/false,
5200 /* Or a static cast. */
5201 result = build_static_cast_1 (type, value, /*c_cast_p=*/true,
5203 /* Or a reinterpret_cast. */
5205 result = build_reinterpret_cast_1 (type, value, /*c_cast_p=*/true,
5207 /* The static_cast or reinterpret_cast may be followed by a
5210 /* A valid cast may result in errors if, for example, a
5211 conversion to am ambiguous base class is required. */
5212 && !error_operand_p (result))
5216 /* Non-class rvalues always have cv-unqualified type. */
5217 if (!CLASS_TYPE_P (type))
5218 type = TYPE_MAIN_VARIANT (type);
5219 result_type = TREE_TYPE (result);
5220 if (!CLASS_TYPE_P (result_type))
5221 result_type = TYPE_MAIN_VARIANT (result_type);
5222 /* If the type of RESULT does not match TYPE, perform a
5223 const_cast to make it match. If the static_cast or
5224 reinterpret_cast succeeded, we will differ by at most
5225 cv-qualification, so the follow-on const_cast is guaranteed
5227 if (!same_type_p (non_reference (type), non_reference (result_type)))
5229 result = build_const_cast_1 (type, result, false, &valid_p);
5230 gcc_assert (valid_p);
5235 return error_mark_node;
5238 /* Build an assignment expression of lvalue LHS from value RHS.
5239 MODIFYCODE is the code for a binary operator that we use
5240 to combine the old value of LHS with RHS to get the new value.
5241 Or else MODIFYCODE is NOP_EXPR meaning do a simple assignment.
5243 C++: If MODIFYCODE is INIT_EXPR, then leave references unbashed. */
5246 build_modify_expr (tree lhs, enum tree_code modifycode, tree rhs)
5250 tree lhstype = TREE_TYPE (lhs);
5251 tree olhstype = lhstype;
5252 tree olhs = NULL_TREE;
5253 bool plain_assign = (modifycode == NOP_EXPR);
5255 /* Avoid duplicate error messages from operands that had errors. */
5256 if (lhs == error_mark_node || rhs == error_mark_node)
5257 return error_mark_node;
5259 /* Handle control structure constructs used as "lvalues". */
5260 switch (TREE_CODE (lhs))
5262 /* Handle --foo = 5; as these are valid constructs in C++. */
5263 case PREDECREMENT_EXPR:
5264 case PREINCREMENT_EXPR:
5265 if (TREE_SIDE_EFFECTS (TREE_OPERAND (lhs, 0)))
5266 lhs = build2 (TREE_CODE (lhs), TREE_TYPE (lhs),
5267 stabilize_reference (TREE_OPERAND (lhs, 0)),
5268 TREE_OPERAND (lhs, 1));
5269 return build2 (COMPOUND_EXPR, lhstype,
5271 build_modify_expr (TREE_OPERAND (lhs, 0),
5274 /* Handle (a, b) used as an "lvalue". */
5276 newrhs = build_modify_expr (TREE_OPERAND (lhs, 1),
5278 if (newrhs == error_mark_node)
5279 return error_mark_node;
5280 return build2 (COMPOUND_EXPR, lhstype,
5281 TREE_OPERAND (lhs, 0), newrhs);
5284 if (TREE_SIDE_EFFECTS (TREE_OPERAND (lhs, 0)))
5285 lhs = build2 (TREE_CODE (lhs), TREE_TYPE (lhs),
5286 stabilize_reference (TREE_OPERAND (lhs, 0)),
5287 TREE_OPERAND (lhs, 1));
5288 newrhs = build_modify_expr (TREE_OPERAND (lhs, 0), modifycode, rhs);
5289 if (newrhs == error_mark_node)
5290 return error_mark_node;
5291 return build2 (COMPOUND_EXPR, lhstype, lhs, newrhs);
5295 /* MIN_EXPR and MAX_EXPR are currently only permitted as lvalues,
5296 when neither operand has side-effects. */
5297 if (!lvalue_or_else (lhs, lv_assign))
5298 return error_mark_node;
5300 gcc_assert (!TREE_SIDE_EFFECTS (TREE_OPERAND (lhs, 0))
5301 && !TREE_SIDE_EFFECTS (TREE_OPERAND (lhs, 1)));
5303 lhs = build3 (COND_EXPR, TREE_TYPE (lhs),
5304 build2 (TREE_CODE (lhs) == MIN_EXPR ? LE_EXPR : GE_EXPR,
5306 TREE_OPERAND (lhs, 0),
5307 TREE_OPERAND (lhs, 1)),
5308 TREE_OPERAND (lhs, 0),
5309 TREE_OPERAND (lhs, 1));
5312 /* Handle (a ? b : c) used as an "lvalue". */
5315 /* Produce (a ? (b = rhs) : (c = rhs))
5316 except that the RHS goes through a save-expr
5317 so the code to compute it is only emitted once. */
5319 tree preeval = NULL_TREE;
5321 rhs = stabilize_expr (rhs, &preeval);
5323 /* Check this here to avoid odd errors when trying to convert
5324 a throw to the type of the COND_EXPR. */
5325 if (!lvalue_or_else (lhs, lv_assign))
5326 return error_mark_node;
5328 cond = build_conditional_expr
5329 (TREE_OPERAND (lhs, 0),
5330 build_modify_expr (cp_convert (TREE_TYPE (lhs),
5331 TREE_OPERAND (lhs, 1)),
5333 build_modify_expr (cp_convert (TREE_TYPE (lhs),
5334 TREE_OPERAND (lhs, 2)),
5337 if (cond == error_mark_node)
5339 /* Make sure the code to compute the rhs comes out
5340 before the split. */
5342 cond = build2 (COMPOUND_EXPR, TREE_TYPE (lhs), preeval, cond);
5350 if (modifycode == INIT_EXPR)
5352 if (TREE_CODE (rhs) == CONSTRUCTOR)
5354 if (! same_type_p (TREE_TYPE (rhs), lhstype))
5355 /* Call convert to generate an error; see PR 11063. */
5356 rhs = convert (lhstype, rhs);
5357 result = build2 (INIT_EXPR, lhstype, lhs, rhs);
5358 TREE_SIDE_EFFECTS (result) = 1;
5361 else if (! IS_AGGR_TYPE (lhstype))
5362 /* Do the default thing. */;
5365 result = build_special_member_call (lhs, complete_ctor_identifier,
5366 build_tree_list (NULL_TREE, rhs),
5367 lhstype, LOOKUP_NORMAL);
5368 if (result == NULL_TREE)
5369 return error_mark_node;
5375 if (TREE_CODE (lhstype) == REFERENCE_TYPE)
5377 lhs = convert_from_reference (lhs);
5378 olhstype = lhstype = TREE_TYPE (lhs);
5380 lhs = require_complete_type (lhs);
5381 if (lhs == error_mark_node)
5382 return error_mark_node;
5384 if (modifycode == NOP_EXPR)
5386 /* `operator=' is not an inheritable operator. */
5387 if (! IS_AGGR_TYPE (lhstype))
5388 /* Do the default thing. */;
5391 result = build_new_op (MODIFY_EXPR, LOOKUP_NORMAL,
5392 lhs, rhs, make_node (NOP_EXPR),
5393 /*overloaded_p=*/NULL);
5394 if (result == NULL_TREE)
5395 return error_mark_node;
5402 /* A binary op has been requested. Combine the old LHS
5403 value with the RHS producing the value we should actually
5404 store into the LHS. */
5406 gcc_assert (!PROMOTES_TO_AGGR_TYPE (lhstype, REFERENCE_TYPE));
5407 lhs = stabilize_reference (lhs);
5408 newrhs = cp_build_binary_op (modifycode, lhs, rhs);
5409 if (newrhs == error_mark_node)
5411 error (" in evaluation of %<%Q(%#T, %#T)%>", modifycode,
5412 TREE_TYPE (lhs), TREE_TYPE (rhs));
5413 return error_mark_node;
5416 /* Now it looks like a plain assignment. */
5417 modifycode = NOP_EXPR;
5419 gcc_assert (TREE_CODE (lhstype) != REFERENCE_TYPE);
5420 gcc_assert (TREE_CODE (TREE_TYPE (newrhs)) != REFERENCE_TYPE);
5423 /* The left-hand side must be an lvalue. */
5424 if (!lvalue_or_else (lhs, lv_assign))
5425 return error_mark_node;
5427 /* Warn about modifying something that is `const'. Don't warn if
5428 this is initialization. */
5429 if (modifycode != INIT_EXPR
5430 && (TREE_READONLY (lhs) || CP_TYPE_CONST_P (lhstype)
5431 /* Functions are not modifiable, even though they are
5433 || TREE_CODE (TREE_TYPE (lhs)) == FUNCTION_TYPE
5434 || TREE_CODE (TREE_TYPE (lhs)) == METHOD_TYPE
5435 /* If it's an aggregate and any field is const, then it is
5436 effectively const. */
5437 || (CLASS_TYPE_P (lhstype)
5438 && C_TYPE_FIELDS_READONLY (lhstype))))
5439 readonly_error (lhs, "assignment", 0);
5441 /* If storing into a structure or union member, it has probably been
5442 given type `int'. Compute the type that would go with the actual
5443 amount of storage the member occupies. */
5445 if (TREE_CODE (lhs) == COMPONENT_REF
5446 && (TREE_CODE (lhstype) == INTEGER_TYPE
5447 || TREE_CODE (lhstype) == REAL_TYPE
5448 || TREE_CODE (lhstype) == ENUMERAL_TYPE))
5450 lhstype = TREE_TYPE (get_unwidened (lhs, 0));
5452 /* If storing in a field that is in actuality a short or narrower
5453 than one, we must store in the field in its actual type. */
5455 if (lhstype != TREE_TYPE (lhs))
5457 /* Avoid warnings converting integral types back into enums for
5459 if (TREE_CODE (lhstype) == INTEGER_TYPE
5460 && TREE_CODE (olhstype) == ENUMERAL_TYPE)
5462 if (TREE_SIDE_EFFECTS (lhs))
5463 lhs = stabilize_reference (lhs);
5466 lhs = copy_node (lhs);
5467 TREE_TYPE (lhs) = lhstype;
5471 /* Convert new value to destination type. */
5473 if (TREE_CODE (lhstype) == ARRAY_TYPE)
5477 if (!same_or_base_type_p (TYPE_MAIN_VARIANT (lhstype),
5478 TYPE_MAIN_VARIANT (TREE_TYPE (rhs))))
5480 error ("incompatible types in assignment of %qT to %qT",
5481 TREE_TYPE (rhs), lhstype);
5482 return error_mark_node;
5485 /* Allow array assignment in compiler-generated code. */
5486 if (! DECL_ARTIFICIAL (current_function_decl))
5487 pedwarn ("ISO C++ forbids assignment of arrays");
5489 from_array = TREE_CODE (TREE_TYPE (newrhs)) == ARRAY_TYPE
5490 ? 1 + (modifycode != INIT_EXPR): 0;
5491 return build_vec_init (lhs, NULL_TREE, newrhs, from_array);
5494 if (modifycode == INIT_EXPR)
5495 newrhs = convert_for_initialization (lhs, lhstype, newrhs, LOOKUP_NORMAL,
5496 "initialization", NULL_TREE, 0);
5499 /* Avoid warnings on enum bit fields. */
5500 if (TREE_CODE (olhstype) == ENUMERAL_TYPE
5501 && TREE_CODE (lhstype) == INTEGER_TYPE)
5503 newrhs = convert_for_assignment (olhstype, newrhs, "assignment",
5505 newrhs = convert_force (lhstype, newrhs, 0);
5508 newrhs = convert_for_assignment (lhstype, newrhs, "assignment",
5510 if (TREE_CODE (newrhs) == CALL_EXPR
5511 && TYPE_NEEDS_CONSTRUCTING (lhstype))
5512 newrhs = build_cplus_new (lhstype, newrhs);
5514 /* Can't initialize directly from a TARGET_EXPR, since that would
5515 cause the lhs to be constructed twice, and possibly result in
5516 accidental self-initialization. So we force the TARGET_EXPR to be
5517 expanded without a target. */
5518 if (TREE_CODE (newrhs) == TARGET_EXPR)
5519 newrhs = build2 (COMPOUND_EXPR, TREE_TYPE (newrhs), newrhs,
5520 TREE_OPERAND (newrhs, 0));
5523 if (newrhs == error_mark_node)
5524 return error_mark_node;
5526 result = build2 (modifycode == NOP_EXPR ? MODIFY_EXPR : INIT_EXPR,
5527 lhstype, lhs, newrhs);
5529 TREE_SIDE_EFFECTS (result) = 1;
5531 TREE_NO_WARNING (result) = 1;
5533 /* If we got the LHS in a different type for storing in,
5534 convert the result back to the nominal type of LHS
5535 so that the value we return always has the same type
5536 as the LHS argument. */
5538 if (olhstype == TREE_TYPE (result))
5542 result = build2 (COMPOUND_EXPR, olhstype, result, olhs);
5543 TREE_NO_WARNING (result) = 1;
5546 return convert_for_assignment (olhstype, result, "assignment",
5551 build_x_modify_expr (tree lhs, enum tree_code modifycode, tree rhs)
5553 if (processing_template_decl)
5554 return build_min_nt (MODOP_EXPR, lhs,
5555 build_min_nt (modifycode, NULL_TREE, NULL_TREE), rhs);
5557 if (modifycode != NOP_EXPR)
5559 tree rval = build_new_op (MODIFY_EXPR, LOOKUP_NORMAL, lhs, rhs,
5560 make_node (modifycode),
5561 /*overloaded_p=*/NULL);
5564 TREE_NO_WARNING (rval) = 1;
5568 return build_modify_expr (lhs, modifycode, rhs);
5572 /* Get difference in deltas for different pointer to member function
5573 types. Returns an integer constant of type PTRDIFF_TYPE_NODE. If
5574 the conversion is invalid, the constant is zero. If
5575 ALLOW_INVERSE_P is true, then allow reverse conversions as well.
5576 If C_CAST_P is true this conversion is taking place as part of a
5579 Note that the naming of FROM and TO is kind of backwards; the return
5580 value is what we add to a TO in order to get a FROM. They are named
5581 this way because we call this function to find out how to convert from
5582 a pointer to member of FROM to a pointer to member of TO. */
5585 get_delta_difference (tree from, tree to,
5586 bool allow_inverse_p,
5594 /* Assume no conversion is required. */
5595 result = integer_zero_node;
5596 binfo = lookup_base (to, from, c_cast_p ? ba_unique : ba_check, &kind);
5597 if (kind == bk_inaccessible || kind == bk_ambig)
5598 error (" in pointer to member function conversion");
5601 if (!allow_inverse_p)
5603 error_not_base_type (from, to);
5604 error (" in pointer to member conversion");
5608 binfo = lookup_base (from, to, c_cast_p ? ba_unique : ba_check,
5612 virt_binfo = binfo_from_vbase (binfo);
5614 /* This is a reinterpret cast, we choose to do nothing. */
5615 warning ("pointer to member cast via virtual base %qT",
5616 BINFO_TYPE (virt_binfo));
5618 result = size_diffop (size_zero_node, BINFO_OFFSET (binfo));
5624 virt_binfo = binfo_from_vbase (binfo);
5626 result = BINFO_OFFSET (binfo);
5629 /* This is a reinterpret cast, we choose to do nothing. */
5630 if (allow_inverse_p)
5631 warning ("pointer to member cast via virtual base %qT",
5632 BINFO_TYPE (virt_binfo));
5634 error ("pointer to member conversion via virtual base %qT",
5635 BINFO_TYPE (virt_binfo));
5639 return fold_if_not_in_template (convert_to_integer (ptrdiff_type_node,
5643 /* Return a constructor for the pointer-to-member-function TYPE using
5644 the other components as specified. */
5647 build_ptrmemfunc1 (tree type, tree delta, tree pfn)
5653 /* Pull the FIELD_DECLs out of the type. */
5654 pfn_field = TYPE_FIELDS (type);
5655 delta_field = TREE_CHAIN (pfn_field);
5657 /* Make sure DELTA has the type we want. */
5658 delta = convert_and_check (delta_type_node, delta);
5660 /* Finish creating the initializer. */
5661 u = tree_cons (pfn_field, pfn,
5662 build_tree_list (delta_field, delta));
5663 u = build_constructor (type, u);
5664 TREE_CONSTANT (u) = TREE_CONSTANT (pfn) & TREE_CONSTANT (delta);
5665 TREE_INVARIANT (u) = TREE_INVARIANT (pfn) & TREE_INVARIANT (delta);
5666 TREE_STATIC (u) = (TREE_CONSTANT (u)
5667 && (initializer_constant_valid_p (pfn, TREE_TYPE (pfn))
5669 && (initializer_constant_valid_p (delta, TREE_TYPE (delta))
5674 /* Build a constructor for a pointer to member function. It can be
5675 used to initialize global variables, local variable, or used
5676 as a value in expressions. TYPE is the POINTER to METHOD_TYPE we
5679 If FORCE is nonzero, then force this conversion, even if
5680 we would rather not do it. Usually set when using an explicit
5681 cast. A C-style cast is being processed iff C_CAST_P is true.
5683 Return error_mark_node, if something goes wrong. */
5686 build_ptrmemfunc (tree type, tree pfn, int force, bool c_cast_p)
5692 if (error_operand_p (pfn))
5693 return error_mark_node;
5695 pfn_type = TREE_TYPE (pfn);
5696 to_type = build_ptrmemfunc_type (type);
5698 /* Handle multiple conversions of pointer to member functions. */
5699 if (TYPE_PTRMEMFUNC_P (pfn_type))
5701 tree delta = NULL_TREE;
5702 tree npfn = NULL_TREE;
5706 && !can_convert_arg (to_type, TREE_TYPE (pfn), pfn))
5707 error ("invalid conversion to type %qT from type %qT",
5710 n = get_delta_difference (TYPE_PTRMEMFUNC_OBJECT_TYPE (pfn_type),
5711 TYPE_PTRMEMFUNC_OBJECT_TYPE (to_type),
5715 /* We don't have to do any conversion to convert a
5716 pointer-to-member to its own type. But, we don't want to
5717 just return a PTRMEM_CST if there's an explicit cast; that
5718 cast should make the expression an invalid template argument. */
5719 if (TREE_CODE (pfn) != PTRMEM_CST)
5721 if (same_type_p (to_type, pfn_type))
5723 else if (integer_zerop (n))
5724 return build_reinterpret_cast (to_type, pfn);
5727 if (TREE_SIDE_EFFECTS (pfn))
5728 pfn = save_expr (pfn);
5730 /* Obtain the function pointer and the current DELTA. */
5731 if (TREE_CODE (pfn) == PTRMEM_CST)
5732 expand_ptrmemfunc_cst (pfn, &delta, &npfn);
5735 npfn = build_ptrmemfunc_access_expr (pfn, pfn_identifier);
5736 delta = build_ptrmemfunc_access_expr (pfn, delta_identifier);
5739 /* Just adjust the DELTA field. */
5740 gcc_assert (same_type_ignoring_top_level_qualifiers_p
5741 (TREE_TYPE (delta), ptrdiff_type_node));
5742 if (TARGET_PTRMEMFUNC_VBIT_LOCATION == ptrmemfunc_vbit_in_delta)
5743 n = cp_build_binary_op (LSHIFT_EXPR, n, integer_one_node);
5744 delta = cp_build_binary_op (PLUS_EXPR, delta, n);
5745 return build_ptrmemfunc1 (to_type, delta, npfn);
5748 /* Handle null pointer to member function conversions. */
5749 if (integer_zerop (pfn))
5751 pfn = build_c_cast (type, integer_zero_node);
5752 return build_ptrmemfunc1 (to_type,
5757 if (type_unknown_p (pfn))
5758 return instantiate_type (type, pfn, tf_error | tf_warning);
5760 fn = TREE_OPERAND (pfn, 0);
5761 gcc_assert (TREE_CODE (fn) == FUNCTION_DECL);
5762 return make_ptrmem_cst (to_type, fn);
5765 /* Return the DELTA, IDX, PFN, and DELTA2 values for the PTRMEM_CST
5768 ??? There is no consistency as to the types returned for the above
5769 values. Some code acts as if it were a sizetype and some as if it were
5770 integer_type_node. */
5773 expand_ptrmemfunc_cst (tree cst, tree *delta, tree *pfn)
5775 tree type = TREE_TYPE (cst);
5776 tree fn = PTRMEM_CST_MEMBER (cst);
5777 tree ptr_class, fn_class;
5779 gcc_assert (TREE_CODE (fn) == FUNCTION_DECL);
5781 /* The class that the function belongs to. */
5782 fn_class = DECL_CONTEXT (fn);
5784 /* The class that we're creating a pointer to member of. */
5785 ptr_class = TYPE_PTRMEMFUNC_OBJECT_TYPE (type);
5787 /* First, calculate the adjustment to the function's class. */
5788 *delta = get_delta_difference (fn_class, ptr_class, /*force=*/0,
5791 if (!DECL_VIRTUAL_P (fn))
5792 *pfn = convert (TYPE_PTRMEMFUNC_FN_TYPE (type), build_addr_func (fn));
5795 /* If we're dealing with a virtual function, we have to adjust 'this'
5796 again, to point to the base which provides the vtable entry for
5797 fn; the call will do the opposite adjustment. */
5798 tree orig_class = DECL_CONTEXT (fn);
5799 tree binfo = binfo_or_else (orig_class, fn_class);
5800 *delta = build2 (PLUS_EXPR, TREE_TYPE (*delta),
5801 *delta, BINFO_OFFSET (binfo));
5802 *delta = fold_if_not_in_template (*delta);
5804 /* We set PFN to the vtable offset at which the function can be
5805 found, plus one (unless ptrmemfunc_vbit_in_delta, in which
5806 case delta is shifted left, and then incremented). */
5807 *pfn = DECL_VINDEX (fn);
5808 *pfn = build2 (MULT_EXPR, integer_type_node, *pfn,
5809 TYPE_SIZE_UNIT (vtable_entry_type));
5810 *pfn = fold_if_not_in_template (*pfn);
5812 switch (TARGET_PTRMEMFUNC_VBIT_LOCATION)
5814 case ptrmemfunc_vbit_in_pfn:
5815 *pfn = build2 (PLUS_EXPR, integer_type_node, *pfn,
5817 *pfn = fold_if_not_in_template (*pfn);
5820 case ptrmemfunc_vbit_in_delta:
5821 *delta = build2 (LSHIFT_EXPR, TREE_TYPE (*delta),
5822 *delta, integer_one_node);
5823 *delta = fold_if_not_in_template (*delta);
5824 *delta = build2 (PLUS_EXPR, TREE_TYPE (*delta),
5825 *delta, integer_one_node);
5826 *delta = fold_if_not_in_template (*delta);
5833 *pfn = build_nop (TYPE_PTRMEMFUNC_FN_TYPE (type), *pfn);
5834 *pfn = fold_if_not_in_template (*pfn);
5838 /* Return an expression for PFN from the pointer-to-member function
5842 pfn_from_ptrmemfunc (tree t)
5844 if (TREE_CODE (t) == PTRMEM_CST)
5849 expand_ptrmemfunc_cst (t, &delta, &pfn);
5854 return build_ptrmemfunc_access_expr (t, pfn_identifier);
5857 /* Expression EXPR is about to be implicitly converted to TYPE. Warn
5858 if this is a potentially dangerous thing to do. Returns a possibly
5862 dubious_conversion_warnings (tree type, tree expr,
5863 const char *errtype, tree fndecl, int parmnum)
5865 type = non_reference (type);
5867 /* Issue warnings about peculiar, but valid, uses of NULL. */
5868 if (ARITHMETIC_TYPE_P (type) && expr == null_node)
5871 warning ("passing NULL used for non-pointer %s %P of %qD",
5872 errtype, parmnum, fndecl);
5874 warning ("%s to non-pointer type %qT from NULL", errtype, type);
5877 /* Warn about assigning a floating-point type to an integer type. */
5878 if (TREE_CODE (TREE_TYPE (expr)) == REAL_TYPE
5879 && TREE_CODE (type) == INTEGER_TYPE)
5882 warning ("passing %qT for %s %P of %qD",
5883 TREE_TYPE (expr), errtype, parmnum, fndecl);
5885 warning ("%s to %qT from %qT", errtype, type, TREE_TYPE (expr));
5887 /* And warn about assigning a negative value to an unsigned
5889 else if (TYPE_UNSIGNED (type) && TREE_CODE (type) != BOOLEAN_TYPE)
5891 if (TREE_CODE (expr) == INTEGER_CST && TREE_NEGATED_INT (expr))
5894 warning ("passing negative value %qE for %s %P of %qD",
5895 expr, errtype, parmnum, fndecl);
5897 warning ("%s of negative value %qE to %qT", errtype, expr, type);
5900 overflow_warning (expr);
5902 if (TREE_CONSTANT (expr))
5903 expr = fold_if_not_in_template (expr);
5908 /* Convert value RHS to type TYPE as preparation for an assignment to
5909 an lvalue of type TYPE. ERRTYPE is a string to use in error
5910 messages: "assignment", "return", etc. If FNDECL is non-NULL, we
5911 are doing the conversion in order to pass the PARMNUMth argument of
5915 convert_for_assignment (tree type, tree rhs,
5916 const char *errtype, tree fndecl, int parmnum)
5919 enum tree_code coder;
5921 /* Strip NON_LVALUE_EXPRs since we aren't using as an lvalue. */
5922 if (TREE_CODE (rhs) == NON_LVALUE_EXPR)
5923 rhs = TREE_OPERAND (rhs, 0);
5925 rhstype = TREE_TYPE (rhs);
5926 coder = TREE_CODE (rhstype);
5928 if (TREE_CODE (type) == VECTOR_TYPE && coder == VECTOR_TYPE
5929 && vector_types_convertible_p (type, rhstype))
5930 return convert (type, rhs);
5932 if (rhs == error_mark_node || rhstype == error_mark_node)
5933 return error_mark_node;
5934 if (TREE_CODE (rhs) == TREE_LIST && TREE_VALUE (rhs) == error_mark_node)
5935 return error_mark_node;
5937 /* The RHS of an assignment cannot have void type. */
5938 if (coder == VOID_TYPE)
5940 error ("void value not ignored as it ought to be");
5941 return error_mark_node;
5944 /* Simplify the RHS if possible. */
5945 if (TREE_CODE (rhs) == CONST_DECL)
5946 rhs = DECL_INITIAL (rhs);
5948 /* We do not use decl_constant_value here because of this case:
5950 const char* const s = "s";
5952 The conversion rules for a string literal are more lax than for a
5953 variable; in particular, a string literal can be converted to a
5954 "char *" but the variable "s" cannot be converted in the same
5955 way. If the conversion is allowed, the optimization should be
5956 performed while creating the converted expression. */
5960 The expression is implicitly converted (clause _conv_) to the
5961 cv-unqualified type of the left operand.
5963 We allow bad conversions here because by the time we get to this point
5964 we are committed to doing the conversion. If we end up doing a bad
5965 conversion, convert_like will complain. */
5966 if (!can_convert_arg_bad (type, rhstype, rhs))
5968 /* When -Wno-pmf-conversions is use, we just silently allow
5969 conversions from pointers-to-members to plain pointers. If
5970 the conversion doesn't work, cp_convert will complain. */
5972 && TYPE_PTR_P (type)
5973 && TYPE_PTRMEMFUNC_P (rhstype))
5974 rhs = cp_convert (strip_top_quals (type), rhs);
5977 /* If the right-hand side has unknown type, then it is an
5978 overloaded function. Call instantiate_type to get error
5980 if (rhstype == unknown_type_node)
5981 instantiate_type (type, rhs, tf_error | tf_warning);
5983 error ("cannot convert %qT to %qT for argument %qP to %qD",
5984 rhstype, type, parmnum, fndecl);
5986 error ("cannot convert %qT to %qT in %s", rhstype, type, errtype);
5987 return error_mark_node;
5990 return perform_implicit_conversion (strip_top_quals (type), rhs);
5993 /* Convert RHS to be of type TYPE.
5994 If EXP is nonzero, it is the target of the initialization.
5995 ERRTYPE is a string to use in error messages.
5997 Two major differences between the behavior of
5998 `convert_for_assignment' and `convert_for_initialization'
5999 are that references are bashed in the former, while
6000 copied in the latter, and aggregates are assigned in
6001 the former (operator=) while initialized in the
6004 If using constructor make sure no conversion operator exists, if one does
6005 exist, an ambiguity exists.
6007 If flags doesn't include LOOKUP_COMPLAIN, don't complain about anything. */
6010 convert_for_initialization (tree exp, tree type, tree rhs, int flags,
6011 const char *errtype, tree fndecl, int parmnum)
6013 enum tree_code codel = TREE_CODE (type);
6015 enum tree_code coder;
6017 /* build_c_cast puts on a NOP_EXPR to make the result not an lvalue.
6018 Strip such NOP_EXPRs, since RHS is used in non-lvalue context. */
6019 if (TREE_CODE (rhs) == NOP_EXPR
6020 && TREE_TYPE (rhs) == TREE_TYPE (TREE_OPERAND (rhs, 0))
6021 && codel != REFERENCE_TYPE)
6022 rhs = TREE_OPERAND (rhs, 0);
6024 if (rhs == error_mark_node
6025 || (TREE_CODE (rhs) == TREE_LIST && TREE_VALUE (rhs) == error_mark_node))
6026 return error_mark_node;
6028 if (TREE_CODE (TREE_TYPE (rhs)) == REFERENCE_TYPE)
6029 rhs = convert_from_reference (rhs);
6031 if ((TREE_CODE (TREE_TYPE (rhs)) == ARRAY_TYPE
6032 && TREE_CODE (type) != ARRAY_TYPE
6033 && (TREE_CODE (type) != REFERENCE_TYPE
6034 || TREE_CODE (TREE_TYPE (type)) != ARRAY_TYPE))
6035 || (TREE_CODE (TREE_TYPE (rhs)) == FUNCTION_TYPE
6036 && (TREE_CODE (type) != REFERENCE_TYPE
6037 || TREE_CODE (TREE_TYPE (type)) != FUNCTION_TYPE))
6038 || TREE_CODE (TREE_TYPE (rhs)) == METHOD_TYPE)
6039 rhs = decay_conversion (rhs);
6041 rhstype = TREE_TYPE (rhs);
6042 coder = TREE_CODE (rhstype);
6044 if (coder == ERROR_MARK)
6045 return error_mark_node;
6047 /* We accept references to incomplete types, so we can
6048 return here before checking if RHS is of complete type. */
6050 if (codel == REFERENCE_TYPE)
6052 /* This should eventually happen in convert_arguments. */
6053 int savew = 0, savee = 0;
6056 savew = warningcount, savee = errorcount;
6057 rhs = initialize_reference (type, rhs, /*decl=*/NULL_TREE,
6061 if (warningcount > savew)
6062 cp_warning_at ("in passing argument %P of %q+D", parmnum, fndecl);
6063 else if (errorcount > savee)
6064 cp_error_at ("in passing argument %P of %q+D", parmnum, fndecl);
6070 exp = require_complete_type (exp);
6071 if (exp == error_mark_node)
6072 return error_mark_node;
6074 rhstype = non_reference (rhstype);
6076 type = complete_type (type);
6078 if (IS_AGGR_TYPE (type))
6079 return ocp_convert (type, rhs, CONV_IMPLICIT|CONV_FORCE_TEMP, flags);
6081 return convert_for_assignment (type, rhs, errtype, fndecl, parmnum);
6084 /* If RETVAL is the address of, or a reference to, a local variable or
6085 temporary give an appropriate warning. */
6088 maybe_warn_about_returning_address_of_local (tree retval)
6090 tree valtype = TREE_TYPE (DECL_RESULT (current_function_decl));
6091 tree whats_returned = retval;
6095 if (TREE_CODE (whats_returned) == COMPOUND_EXPR)
6096 whats_returned = TREE_OPERAND (whats_returned, 1);
6097 else if (TREE_CODE (whats_returned) == CONVERT_EXPR
6098 || TREE_CODE (whats_returned) == NON_LVALUE_EXPR
6099 || TREE_CODE (whats_returned) == NOP_EXPR)
6100 whats_returned = TREE_OPERAND (whats_returned, 0);
6105 if (TREE_CODE (whats_returned) != ADDR_EXPR)
6107 whats_returned = TREE_OPERAND (whats_returned, 0);
6109 if (TREE_CODE (valtype) == REFERENCE_TYPE)
6111 if (TREE_CODE (whats_returned) == AGGR_INIT_EXPR
6112 || TREE_CODE (whats_returned) == TARGET_EXPR)
6114 warning ("returning reference to temporary");
6117 if (TREE_CODE (whats_returned) == VAR_DECL
6118 && DECL_NAME (whats_returned)
6119 && TEMP_NAME_P (DECL_NAME (whats_returned)))
6121 warning ("reference to non-lvalue returned");
6126 if (DECL_P (whats_returned)
6127 && DECL_NAME (whats_returned)
6128 && DECL_FUNCTION_SCOPE_P (whats_returned)
6129 && !(TREE_STATIC (whats_returned)
6130 || TREE_PUBLIC (whats_returned)))
6132 if (TREE_CODE (valtype) == REFERENCE_TYPE)
6133 cp_warning_at ("reference to local variable %qD returned",
6136 cp_warning_at ("address of local variable %qD returned",
6142 /* Check that returning RETVAL from the current function is valid.
6143 Return an expression explicitly showing all conversions required to
6144 change RETVAL into the function return type, and to assign it to
6145 the DECL_RESULT for the function. */
6148 check_return_expr (tree retval)
6151 /* The type actually returned by the function, after any
6154 int fn_returns_value_p;
6156 /* A `volatile' function is one that isn't supposed to return, ever.
6157 (This is a G++ extension, used to get better code for functions
6158 that call the `volatile' function.) */
6159 if (TREE_THIS_VOLATILE (current_function_decl))
6160 warning ("function declared %<noreturn%> has a %<return%> statement");
6162 /* Check for various simple errors. */
6163 if (DECL_DESTRUCTOR_P (current_function_decl))
6166 error ("returning a value from a destructor");
6169 else if (DECL_CONSTRUCTOR_P (current_function_decl))
6171 if (in_function_try_handler)
6172 /* If a return statement appears in a handler of the
6173 function-try-block of a constructor, the program is ill-formed. */
6174 error ("cannot return from a handler of a function-try-block of a constructor");
6176 /* You can't return a value from a constructor. */
6177 error ("returning a value from a constructor");
6181 if (processing_template_decl)
6183 current_function_returns_value = 1;
6187 /* When no explicit return-value is given in a function with a named
6188 return value, the named return value is used. */
6189 result = DECL_RESULT (current_function_decl);
6190 valtype = TREE_TYPE (result);
6191 gcc_assert (valtype != NULL_TREE);
6192 fn_returns_value_p = !VOID_TYPE_P (valtype);
6193 if (!retval && DECL_NAME (result) && fn_returns_value_p)
6196 /* Check for a return statement with no return value in a function
6197 that's supposed to return a value. */
6198 if (!retval && fn_returns_value_p)
6200 pedwarn ("return-statement with no value, in function returning %qT",
6202 /* Clear this, so finish_function won't say that we reach the
6203 end of a non-void function (which we don't, we gave a
6205 current_function_returns_null = 0;
6207 /* Check for a return statement with a value in a function that
6208 isn't supposed to return a value. */
6209 else if (retval && !fn_returns_value_p)
6211 if (VOID_TYPE_P (TREE_TYPE (retval)))
6212 /* You can return a `void' value from a function of `void'
6213 type. In that case, we have to evaluate the expression for
6214 its side-effects. */
6215 finish_expr_stmt (retval);
6217 pedwarn ("return-statement with a value, in function "
6218 "returning 'void'");
6220 current_function_returns_null = 1;
6222 /* There's really no value to return, after all. */
6226 /* Remember that this function can sometimes return without a
6228 current_function_returns_null = 1;
6230 /* Remember that this function did return a value. */
6231 current_function_returns_value = 1;
6233 /* Check for errnoneous operands -- but after giving ourselves a
6234 chance to provide an error about returning a value from a void
6236 if (error_operand_p (retval))
6238 current_function_return_value = error_mark_node;
6239 return error_mark_node;
6242 /* Only operator new(...) throw(), can return NULL [expr.new/13]. */
6243 if ((DECL_OVERLOADED_OPERATOR_P (current_function_decl) == NEW_EXPR
6244 || DECL_OVERLOADED_OPERATOR_P (current_function_decl) == VEC_NEW_EXPR)
6245 && !TYPE_NOTHROW_P (TREE_TYPE (current_function_decl))
6247 && null_ptr_cst_p (retval))
6248 warning ("%<operator new%> must not return NULL unless it is "
6249 "declared %<throw()%> (or -fcheck-new is in effect)");
6251 /* Effective C++ rule 15. See also start_function. */
6253 && DECL_NAME (current_function_decl) == ansi_assopname(NOP_EXPR))
6257 /* The function return type must be a reference to the current
6259 if (TREE_CODE (valtype) == REFERENCE_TYPE
6260 && same_type_ignoring_top_level_qualifiers_p
6261 (TREE_TYPE (valtype), TREE_TYPE (current_class_ref)))
6263 /* Returning '*this' is obviously OK. */
6264 if (retval == current_class_ref)
6266 /* If we are calling a function whose return type is the same of
6267 the current class reference, it is ok. */
6268 else if (TREE_CODE (retval) == INDIRECT_REF
6269 && TREE_CODE (TREE_OPERAND (retval, 0)) == CALL_EXPR)
6274 warning ("%<operator=%> should return a reference to %<*this%>");
6277 /* The fabled Named Return Value optimization, as per [class.copy]/15:
6279 [...] For a function with a class return type, if the expression
6280 in the return statement is the name of a local object, and the cv-
6281 unqualified type of the local object is the same as the function
6282 return type, an implementation is permitted to omit creating the tem-
6283 porary object to hold the function return value [...]
6285 So, if this is a value-returning function that always returns the same
6286 local variable, remember it.
6288 It might be nice to be more flexible, and choose the first suitable
6289 variable even if the function sometimes returns something else, but
6290 then we run the risk of clobbering the variable we chose if the other
6291 returned expression uses the chosen variable somehow. And people expect
6292 this restriction, anyway. (jason 2000-11-19)
6294 See finish_function and finalize_nrv for the rest of this optimization. */
6296 if (fn_returns_value_p && flag_elide_constructors)
6298 if (retval != NULL_TREE
6299 && (current_function_return_value == NULL_TREE
6300 || current_function_return_value == retval)
6301 && TREE_CODE (retval) == VAR_DECL
6302 && DECL_CONTEXT (retval) == current_function_decl
6303 && ! TREE_STATIC (retval)
6304 && (DECL_ALIGN (retval)
6305 >= DECL_ALIGN (DECL_RESULT (current_function_decl)))
6306 && same_type_p ((TYPE_MAIN_VARIANT
6307 (TREE_TYPE (retval))),
6309 (TREE_TYPE (TREE_TYPE (current_function_decl))))))
6310 current_function_return_value = retval;
6312 current_function_return_value = error_mark_node;
6315 /* We don't need to do any conversions when there's nothing being
6320 /* Do any required conversions. */
6321 if (retval == result || DECL_CONSTRUCTOR_P (current_function_decl))
6322 /* No conversions are required. */
6326 /* The type the function is declared to return. */
6327 tree functype = TREE_TYPE (TREE_TYPE (current_function_decl));
6329 /* First convert the value to the function's return type, then
6330 to the type of return value's location to handle the
6331 case that functype is smaller than the valtype. */
6332 retval = convert_for_initialization
6333 (NULL_TREE, functype, retval, LOOKUP_NORMAL|LOOKUP_ONLYCONVERTING,
6334 "return", NULL_TREE, 0);
6335 retval = convert (valtype, retval);
6337 /* If the conversion failed, treat this just like `return;'. */
6338 if (retval == error_mark_node)
6340 /* We can't initialize a register from a AGGR_INIT_EXPR. */
6341 else if (! current_function_returns_struct
6342 && TREE_CODE (retval) == TARGET_EXPR
6343 && TREE_CODE (TREE_OPERAND (retval, 1)) == AGGR_INIT_EXPR)
6344 retval = build2 (COMPOUND_EXPR, TREE_TYPE (retval), retval,
6345 TREE_OPERAND (retval, 0));
6347 maybe_warn_about_returning_address_of_local (retval);
6350 /* Actually copy the value returned into the appropriate location. */
6351 if (retval && retval != result)
6352 retval = build2 (INIT_EXPR, TREE_TYPE (result), result, retval);
6358 /* Returns nonzero if the pointer-type FROM can be converted to the
6359 pointer-type TO via a qualification conversion. If CONSTP is -1,
6360 then we return nonzero if the pointers are similar, and the
6361 cv-qualification signature of FROM is a proper subset of that of TO.
6363 If CONSTP is positive, then all outer pointers have been
6367 comp_ptr_ttypes_real (tree to, tree from, int constp)
6369 bool to_more_cv_qualified = false;
6371 for (; ; to = TREE_TYPE (to), from = TREE_TYPE (from))
6373 if (TREE_CODE (to) != TREE_CODE (from))
6376 if (TREE_CODE (from) == OFFSET_TYPE
6377 && !same_type_p (TYPE_OFFSET_BASETYPE (from),
6378 TYPE_OFFSET_BASETYPE (to)))
6381 /* Const and volatile mean something different for function types,
6382 so the usual checks are not appropriate. */
6383 if (TREE_CODE (to) != FUNCTION_TYPE && TREE_CODE (to) != METHOD_TYPE)
6385 if (!at_least_as_qualified_p (to, from))
6388 if (!at_least_as_qualified_p (from, to))
6392 to_more_cv_qualified = true;
6396 constp &= TYPE_READONLY (to);
6399 if (TREE_CODE (to) != POINTER_TYPE && !TYPE_PTRMEM_P (to))
6400 return ((constp >= 0 || to_more_cv_qualified)
6401 && same_type_ignoring_top_level_qualifiers_p (to, from));
6405 /* When comparing, say, char ** to char const **, this function takes
6406 the 'char *' and 'char const *'. Do not pass non-pointer/reference
6407 types to this function. */
6410 comp_ptr_ttypes (tree to, tree from)
6412 return comp_ptr_ttypes_real (to, from, 1);
6415 /* Returns 1 if to and from are (possibly multi-level) pointers to the same
6416 type or inheritance-related types, regardless of cv-quals. */
6419 ptr_reasonably_similar (tree to, tree from)
6421 for (; ; to = TREE_TYPE (to), from = TREE_TYPE (from))
6423 /* Any target type is similar enough to void. */
6424 if (TREE_CODE (to) == VOID_TYPE
6425 || TREE_CODE (from) == VOID_TYPE)
6428 if (TREE_CODE (to) != TREE_CODE (from))
6431 if (TREE_CODE (from) == OFFSET_TYPE
6432 && comptypes (TYPE_OFFSET_BASETYPE (to),
6433 TYPE_OFFSET_BASETYPE (from),
6434 COMPARE_BASE | COMPARE_DERIVED))
6437 if (TREE_CODE (to) == VECTOR_TYPE
6438 && vector_types_convertible_p (to, from))
6441 if (TREE_CODE (to) == INTEGER_TYPE
6442 && TYPE_PRECISION (to) == TYPE_PRECISION (from))
6445 if (TREE_CODE (to) == FUNCTION_TYPE)
6448 if (TREE_CODE (to) != POINTER_TYPE)
6450 (TYPE_MAIN_VARIANT (to), TYPE_MAIN_VARIANT (from),
6451 COMPARE_BASE | COMPARE_DERIVED);
6455 /* Like comp_ptr_ttypes, for const_cast. */
6458 comp_ptr_ttypes_const (tree to, tree from)
6460 for (; ; to = TREE_TYPE (to), from = TREE_TYPE (from))
6462 if (TREE_CODE (to) != TREE_CODE (from))
6465 if (TREE_CODE (from) == OFFSET_TYPE
6466 && same_type_p (TYPE_OFFSET_BASETYPE (from),
6467 TYPE_OFFSET_BASETYPE (to)))
6470 if (TREE_CODE (to) != POINTER_TYPE)
6471 return same_type_ignoring_top_level_qualifiers_p (to, from);
6475 /* Returns the type qualifiers for this type, including the qualifiers on the
6476 elements for an array type. */
6479 cp_type_quals (tree type)
6481 type = strip_array_types (type);
6482 if (type == error_mark_node)
6483 return TYPE_UNQUALIFIED;
6484 return TYPE_QUALS (type);
6487 /* Returns nonzero if the TYPE contains a mutable member. */
6490 cp_has_mutable_p (tree type)
6492 type = strip_array_types (type);
6494 return CLASS_TYPE_P (type) && CLASSTYPE_HAS_MUTABLE (type);
6497 /* Subroutine of casts_away_constness. Make T1 and T2 point at
6498 exemplar types such that casting T1 to T2 is casting away constness
6499 if and only if there is no implicit conversion from T1 to T2. */
6502 casts_away_constness_r (tree *t1, tree *t2)
6507 /* [expr.const.cast]
6509 For multi-level pointer to members and multi-level mixed pointers
6510 and pointers to members (conv.qual), the "member" aspect of a
6511 pointer to member level is ignored when determining if a const
6512 cv-qualifier has been cast away. */
6513 if (TYPE_PTRMEM_P (*t1))
6514 *t1 = build_pointer_type (TYPE_PTRMEM_POINTED_TO_TYPE (*t1));
6515 if (TYPE_PTRMEM_P (*t2))
6516 *t2 = build_pointer_type (TYPE_PTRMEM_POINTED_TO_TYPE (*t2));
6518 /* [expr.const.cast]
6520 For two pointer types:
6522 X1 is T1cv1,1 * ... cv1,N * where T1 is not a pointer type
6523 X2 is T2cv2,1 * ... cv2,M * where T2 is not a pointer type
6526 casting from X1 to X2 casts away constness if, for a non-pointer
6527 type T there does not exist an implicit conversion (clause
6530 Tcv1,(N-K+1) * cv1,(N-K+2) * ... cv1,N *
6534 Tcv2,(M-K+1) * cv2,(M-K+2) * ... cv2,M *. */
6536 if (TREE_CODE (*t1) != POINTER_TYPE
6537 || TREE_CODE (*t2) != POINTER_TYPE)
6539 *t1 = cp_build_qualified_type (void_type_node,
6540 cp_type_quals (*t1));
6541 *t2 = cp_build_qualified_type (void_type_node,
6542 cp_type_quals (*t2));
6546 quals1 = cp_type_quals (*t1);
6547 quals2 = cp_type_quals (*t2);
6548 *t1 = TREE_TYPE (*t1);
6549 *t2 = TREE_TYPE (*t2);
6550 casts_away_constness_r (t1, t2);
6551 *t1 = build_pointer_type (*t1);
6552 *t2 = build_pointer_type (*t2);
6553 *t1 = cp_build_qualified_type (*t1, quals1);
6554 *t2 = cp_build_qualified_type (*t2, quals2);
6557 /* Returns nonzero if casting from TYPE1 to TYPE2 casts away
6561 casts_away_constness (tree t1, tree t2)
6563 if (TREE_CODE (t2) == REFERENCE_TYPE)
6565 /* [expr.const.cast]
6567 Casting from an lvalue of type T1 to an lvalue of type T2
6568 using a reference cast casts away constness if a cast from an
6569 rvalue of type "pointer to T1" to the type "pointer to T2"
6570 casts away constness. */
6571 t1 = (TREE_CODE (t1) == REFERENCE_TYPE ? TREE_TYPE (t1) : t1);
6572 return casts_away_constness (build_pointer_type (t1),
6573 build_pointer_type (TREE_TYPE (t2)));
6576 if (TYPE_PTRMEM_P (t1) && TYPE_PTRMEM_P (t2))
6577 /* [expr.const.cast]
6579 Casting from an rvalue of type "pointer to data member of X
6580 of type T1" to the type "pointer to data member of Y of type
6581 T2" casts away constness if a cast from an rvalue of type
6582 "pointer to T1" to the type "pointer to T2" casts away
6584 return casts_away_constness
6585 (build_pointer_type (TYPE_PTRMEM_POINTED_TO_TYPE (t1)),
6586 build_pointer_type (TYPE_PTRMEM_POINTED_TO_TYPE (t2)));
6588 /* Casting away constness is only something that makes sense for
6589 pointer or reference types. */
6590 if (TREE_CODE (t1) != POINTER_TYPE
6591 || TREE_CODE (t2) != POINTER_TYPE)
6594 /* Top-level qualifiers don't matter. */
6595 t1 = TYPE_MAIN_VARIANT (t1);
6596 t2 = TYPE_MAIN_VARIANT (t2);
6597 casts_away_constness_r (&t1, &t2);
6598 if (!can_convert (t2, t1))
6604 /* If T is a REFERENCE_TYPE return the type to which T refers.
6605 Otherwise, return T itself. */
6608 non_reference (tree t)
6610 if (TREE_CODE (t) == REFERENCE_TYPE)