1 /* Build expressions with type checking for C++ compiler.
2 Copyright (C) 1987, 1988, 1989, 1992, 1993, 1994, 1995, 1996, 1997, 1998,
3 1999, 2000, 2001, 2002, 2003, 2004 Free Software Foundation, Inc.
4 Hacked by Michael Tiemann (tiemann@cygnus.com)
6 This file is part of GCC.
8 GCC is free software; you can redistribute it and/or modify
9 it under the terms of the GNU General Public License as published by
10 the Free Software Foundation; either version 2, or (at your option)
13 GCC is distributed in the hope that it will be useful,
14 but WITHOUT ANY WARRANTY; without even the implied warranty of
15 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 GNU General Public License for more details.
18 You should have received a copy of the GNU General Public License
19 along with GCC; see the file COPYING. If not, write to
20 the Free Software Foundation, 59 Temple Place - Suite 330,
21 Boston, MA 02111-1307, USA. */
24 /* This file is part of the C++ front end.
25 It contains routines to build C++ expressions given their operands,
26 including computing the types of the result, C and C++ specific error
27 checks, and some optimization. */
31 #include "coretypes.h"
41 #include "diagnostic.h"
46 static tree convert_for_assignment (tree, tree, const char *, tree, int);
47 static tree cp_pointer_int_sum (enum tree_code, tree, tree);
48 static tree rationalize_conditional_expr (enum tree_code, tree);
49 static int comp_ptr_ttypes_real (tree, tree, int);
50 static int comp_ptr_ttypes_const (tree, tree);
51 static bool comp_except_types (tree, tree, bool);
52 static bool comp_array_types (tree, tree, bool);
53 static tree common_base_type (tree, tree);
54 static tree pointer_diff (tree, tree, tree);
55 static tree get_delta_difference (tree, tree, bool, bool);
56 static void casts_away_constness_r (tree *, tree *);
57 static bool casts_away_constness (tree, tree);
58 static void maybe_warn_about_returning_address_of_local (tree);
59 static tree lookup_destructor (tree, tree, tree);
61 /* Return the target type of TYPE, which means return T for:
62 T*, T&, T[], T (...), and otherwise, just T. */
65 target_type (tree type)
67 type = non_reference (type);
68 while (TREE_CODE (type) == POINTER_TYPE
69 || TREE_CODE (type) == ARRAY_TYPE
70 || TREE_CODE (type) == FUNCTION_TYPE
71 || TREE_CODE (type) == METHOD_TYPE
72 || TYPE_PTRMEM_P (type))
73 type = TREE_TYPE (type);
77 /* Do `exp = require_complete_type (exp);' to make sure exp
78 does not have an incomplete type. (That includes void types.)
79 Returns the error_mark_node if the VALUE does not have
80 complete type when this function returns. */
83 require_complete_type (tree value)
87 if (processing_template_decl || value == error_mark_node)
90 if (TREE_CODE (value) == OVERLOAD)
91 type = unknown_type_node;
93 type = TREE_TYPE (value);
95 if (type == error_mark_node)
96 return error_mark_node;
98 /* First, detect a valid value with a complete type. */
99 if (COMPLETE_TYPE_P (type))
102 if (complete_type_or_else (type, value))
105 return error_mark_node;
108 /* Try to complete TYPE, if it is incomplete. For example, if TYPE is
109 a template instantiation, do the instantiation. Returns TYPE,
110 whether or not it could be completed, unless something goes
111 horribly wrong, in which case the error_mark_node is returned. */
114 complete_type (tree type)
116 if (type == NULL_TREE)
117 /* Rather than crash, we return something sure to cause an error
119 return error_mark_node;
121 if (type == error_mark_node || COMPLETE_TYPE_P (type))
123 else if (TREE_CODE (type) == ARRAY_TYPE && TYPE_DOMAIN (type))
125 tree t = complete_type (TREE_TYPE (type));
126 if (COMPLETE_TYPE_P (t) && !dependent_type_p (type))
128 TYPE_NEEDS_CONSTRUCTING (type)
129 = TYPE_NEEDS_CONSTRUCTING (TYPE_MAIN_VARIANT (t));
130 TYPE_HAS_NONTRIVIAL_DESTRUCTOR (type)
131 = TYPE_HAS_NONTRIVIAL_DESTRUCTOR (TYPE_MAIN_VARIANT (t));
133 else if (CLASS_TYPE_P (type) && CLASSTYPE_TEMPLATE_INSTANTIATION (type))
134 instantiate_class_template (TYPE_MAIN_VARIANT (type));
139 /* Like complete_type, but issue an error if the TYPE cannot be completed.
140 VALUE is used for informative diagnostics. DIAG_TYPE indicates the type
141 of diagnostic: 0 for an error, 1 for a warning, 2 for a pedwarn.
142 Returns NULL_TREE if the type cannot be made complete. */
145 complete_type_or_diagnostic (tree type, tree value, int diag_type)
147 type = complete_type (type);
148 if (type == error_mark_node)
149 /* We already issued an error. */
151 else if (!COMPLETE_TYPE_P (type))
153 cxx_incomplete_type_diagnostic (value, type, diag_type);
160 /* Return truthvalue of whether type of EXP is instantiated. */
163 type_unknown_p (tree exp)
165 return (TREE_CODE (exp) == TREE_LIST
166 || TREE_TYPE (exp) == unknown_type_node);
170 /* Return the common type of two parameter lists.
171 We assume that comptypes has already been done and returned 1;
172 if that isn't so, this may crash.
174 As an optimization, free the space we allocate if the parameter
175 lists are already common. */
178 commonparms (tree p1, tree p2)
180 tree oldargs = p1, newargs, n;
184 len = list_length (p1);
185 newargs = tree_last (p1);
187 if (newargs == void_list_node)
196 newargs = tree_cons (NULL_TREE, NULL_TREE, newargs);
201 p1 = TREE_CHAIN (p1), p2 = TREE_CHAIN (p2), n = TREE_CHAIN (n), i++)
203 if (TREE_PURPOSE (p1) && !TREE_PURPOSE (p2))
205 TREE_PURPOSE (n) = TREE_PURPOSE (p1);
208 else if (! TREE_PURPOSE (p1))
210 if (TREE_PURPOSE (p2))
212 TREE_PURPOSE (n) = TREE_PURPOSE (p2);
218 if (1 != simple_cst_equal (TREE_PURPOSE (p1), TREE_PURPOSE (p2)))
220 TREE_PURPOSE (n) = TREE_PURPOSE (p2);
222 if (TREE_VALUE (p1) != TREE_VALUE (p2))
225 TREE_VALUE (n) = merge_types (TREE_VALUE (p1), TREE_VALUE (p2));
228 TREE_VALUE (n) = TREE_VALUE (p1);
236 /* Given a type, perhaps copied for a typedef,
237 find the "original" version of it. */
239 original_type (tree t)
241 while (TYPE_NAME (t) != NULL_TREE)
243 tree x = TYPE_NAME (t);
244 if (TREE_CODE (x) != TYPE_DECL)
246 x = DECL_ORIGINAL_TYPE (x);
254 /* T1 and T2 are arithmetic or enumeration types. Return the type
255 that will result from the "usual arithmetic conversions" on T1 and
256 T2 as described in [expr]. */
259 type_after_usual_arithmetic_conversions (tree t1, tree t2)
261 enum tree_code code1 = TREE_CODE (t1);
262 enum tree_code code2 = TREE_CODE (t2);
265 /* FIXME: Attributes. */
266 gcc_assert (ARITHMETIC_TYPE_P (t1)
267 || TREE_CODE (t1) == COMPLEX_TYPE
268 || TREE_CODE (t1) == ENUMERAL_TYPE);
269 gcc_assert (ARITHMETIC_TYPE_P (t2)
270 || TREE_CODE (t2) == COMPLEX_TYPE
271 || TREE_CODE (t2) == ENUMERAL_TYPE);
273 /* In what follows, we slightly generalize the rules given in [expr] so
274 as to deal with `long long' and `complex'. First, merge the
276 attributes = (*targetm.merge_type_attributes) (t1, t2);
278 /* If one type is complex, form the common type of the non-complex
279 components, then make that complex. Use T1 or T2 if it is the
281 if (code1 == COMPLEX_TYPE || code2 == COMPLEX_TYPE)
283 tree subtype1 = code1 == COMPLEX_TYPE ? TREE_TYPE (t1) : t1;
284 tree subtype2 = code2 == COMPLEX_TYPE ? TREE_TYPE (t2) : t2;
286 = type_after_usual_arithmetic_conversions (subtype1, subtype2);
288 if (code1 == COMPLEX_TYPE && TREE_TYPE (t1) == subtype)
289 return build_type_attribute_variant (t1, attributes);
290 else if (code2 == COMPLEX_TYPE && TREE_TYPE (t2) == subtype)
291 return build_type_attribute_variant (t2, attributes);
293 return build_type_attribute_variant (build_complex_type (subtype),
297 /* If only one is real, use it as the result. */
298 if (code1 == REAL_TYPE && code2 != REAL_TYPE)
299 return build_type_attribute_variant (t1, attributes);
300 if (code2 == REAL_TYPE && code1 != REAL_TYPE)
301 return build_type_attribute_variant (t2, attributes);
303 /* Perform the integral promotions. */
304 if (code1 != REAL_TYPE)
306 t1 = type_promotes_to (t1);
307 t2 = type_promotes_to (t2);
310 /* Both real or both integers; use the one with greater precision. */
311 if (TYPE_PRECISION (t1) > TYPE_PRECISION (t2))
312 return build_type_attribute_variant (t1, attributes);
313 else if (TYPE_PRECISION (t2) > TYPE_PRECISION (t1))
314 return build_type_attribute_variant (t2, attributes);
316 /* The types are the same; no need to do anything fancy. */
317 if (TYPE_MAIN_VARIANT (t1) == TYPE_MAIN_VARIANT (t2))
318 return build_type_attribute_variant (t1, attributes);
320 if (code1 != REAL_TYPE)
322 /* If one is a sizetype, use it so size_binop doesn't blow up. */
323 if (TYPE_IS_SIZETYPE (t1) > TYPE_IS_SIZETYPE (t2))
324 return build_type_attribute_variant (t1, attributes);
325 if (TYPE_IS_SIZETYPE (t2) > TYPE_IS_SIZETYPE (t1))
326 return build_type_attribute_variant (t2, attributes);
328 /* If one is unsigned long long, then convert the other to unsigned
330 if (same_type_p (TYPE_MAIN_VARIANT (t1), long_long_unsigned_type_node)
331 || same_type_p (TYPE_MAIN_VARIANT (t2), long_long_unsigned_type_node))
332 return build_type_attribute_variant (long_long_unsigned_type_node,
334 /* If one is a long long, and the other is an unsigned long, and
335 long long can represent all the values of an unsigned long, then
336 convert to a long long. Otherwise, convert to an unsigned long
337 long. Otherwise, if either operand is long long, convert the
340 Since we're here, we know the TYPE_PRECISION is the same;
341 therefore converting to long long cannot represent all the values
342 of an unsigned long, so we choose unsigned long long in that
344 if (same_type_p (TYPE_MAIN_VARIANT (t1), long_long_integer_type_node)
345 || same_type_p (TYPE_MAIN_VARIANT (t2), long_long_integer_type_node))
347 tree t = ((TYPE_UNSIGNED (t1) || TYPE_UNSIGNED (t2))
348 ? long_long_unsigned_type_node
349 : long_long_integer_type_node);
350 return build_type_attribute_variant (t, attributes);
353 /* Go through the same procedure, but for longs. */
354 if (same_type_p (TYPE_MAIN_VARIANT (t1), long_unsigned_type_node)
355 || same_type_p (TYPE_MAIN_VARIANT (t2), long_unsigned_type_node))
356 return build_type_attribute_variant (long_unsigned_type_node,
358 if (same_type_p (TYPE_MAIN_VARIANT (t1), long_integer_type_node)
359 || same_type_p (TYPE_MAIN_VARIANT (t2), long_integer_type_node))
361 tree t = ((TYPE_UNSIGNED (t1) || TYPE_UNSIGNED (t2))
362 ? long_unsigned_type_node : long_integer_type_node);
363 return build_type_attribute_variant (t, attributes);
365 /* Otherwise prefer the unsigned one. */
366 if (TYPE_UNSIGNED (t1))
367 return build_type_attribute_variant (t1, attributes);
369 return build_type_attribute_variant (t2, attributes);
373 if (same_type_p (TYPE_MAIN_VARIANT (t1), long_double_type_node)
374 || same_type_p (TYPE_MAIN_VARIANT (t2), long_double_type_node))
375 return build_type_attribute_variant (long_double_type_node,
377 if (same_type_p (TYPE_MAIN_VARIANT (t1), double_type_node)
378 || same_type_p (TYPE_MAIN_VARIANT (t2), double_type_node))
379 return build_type_attribute_variant (double_type_node,
381 if (same_type_p (TYPE_MAIN_VARIANT (t1), float_type_node)
382 || same_type_p (TYPE_MAIN_VARIANT (t2), float_type_node))
383 return build_type_attribute_variant (float_type_node,
386 /* Two floating-point types whose TYPE_MAIN_VARIANTs are none of
387 the standard C++ floating-point types. Logic earlier in this
388 function has already eliminated the possibility that
389 TYPE_PRECISION (t2) != TYPE_PRECISION (t1), so there's no
390 compelling reason to choose one or the other. */
391 return build_type_attribute_variant (t1, attributes);
395 /* Subroutine of composite_pointer_type to implement the recursive
396 case. See that function for documentation fo the parameters. */
399 composite_pointer_type_r (tree t1, tree t2, const char* location)
406 /* Determine the types pointed to by T1 and T2. */
407 if (TREE_CODE (t1) == POINTER_TYPE)
409 pointee1 = TREE_TYPE (t1);
410 pointee2 = TREE_TYPE (t2);
414 pointee1 = TYPE_PTRMEM_POINTED_TO_TYPE (t1);
415 pointee2 = TYPE_PTRMEM_POINTED_TO_TYPE (t2);
420 Otherwise, the composite pointer type is a pointer type
421 similar (_conv.qual_) to the type of one of the operands,
422 with a cv-qualification signature (_conv.qual_) that is the
423 union of the cv-qualification signatures of the operand
425 if (same_type_ignoring_top_level_qualifiers_p (pointee1, pointee2))
426 result_type = pointee1;
427 else if ((TREE_CODE (pointee1) == POINTER_TYPE
428 && TREE_CODE (pointee2) == POINTER_TYPE)
429 || (TYPE_PTR_TO_MEMBER_P (pointee1)
430 && TYPE_PTR_TO_MEMBER_P (pointee2)))
431 result_type = composite_pointer_type_r (pointee1, pointee2, location);
434 pedwarn ("%s between distinct pointer types %qT and %qT "
437 result_type = void_type_node;
439 result_type = cp_build_qualified_type (result_type,
440 (cp_type_quals (pointee1)
441 | cp_type_quals (pointee2)));
442 /* If the original types were pointers to members, so is the
444 if (TYPE_PTR_TO_MEMBER_P (t1))
446 if (!same_type_p (TYPE_PTRMEM_CLASS_TYPE (t1),
447 TYPE_PTRMEM_CLASS_TYPE (t2)))
448 pedwarn ("%s between distinct pointer types %qT and %qT "
451 result_type = build_ptrmem_type (TYPE_PTRMEM_CLASS_TYPE (t1),
455 result_type = build_pointer_type (result_type);
457 /* Merge the attributes. */
458 attributes = (*targetm.merge_type_attributes) (t1, t2);
459 return build_type_attribute_variant (result_type, attributes);
462 /* Return the composite pointer type (see [expr.rel]) for T1 and T2.
463 ARG1 and ARG2 are the values with those types. The LOCATION is a
464 string describing the current location, in case an error occurs.
466 This routine also implements the computation of a common type for
467 pointers-to-members as per [expr.eq]. */
470 composite_pointer_type (tree t1, tree t2, tree arg1, tree arg2,
471 const char* location)
478 If one operand is a null pointer constant, the composite pointer
479 type is the type of the other operand. */
480 if (null_ptr_cst_p (arg1))
482 if (null_ptr_cst_p (arg2))
489 If one of the operands has type "pointer to cv1 void*", then
490 the other has type "pointer to cv2T", and the composite pointer
491 type is "pointer to cv12 void", where cv12 is the union of cv1
494 If either type is a pointer to void, make sure it is T1. */
495 if (TREE_CODE (t2) == POINTER_TYPE && VOID_TYPE_P (TREE_TYPE (t2)))
503 /* Now, if T1 is a pointer to void, merge the qualifiers. */
504 if (TREE_CODE (t1) == POINTER_TYPE && VOID_TYPE_P (TREE_TYPE (t1)))
509 if (pedantic && TYPE_PTRFN_P (t2))
510 pedwarn ("ISO C++ forbids %s between pointer of type %<void *%> "
511 "and pointer-to-function", location);
513 = cp_build_qualified_type (void_type_node,
514 (cp_type_quals (TREE_TYPE (t1))
515 | cp_type_quals (TREE_TYPE (t2))));
516 result_type = build_pointer_type (result_type);
517 /* Merge the attributes. */
518 attributes = (*targetm.merge_type_attributes) (t1, t2);
519 return build_type_attribute_variant (result_type, attributes);
522 /* [expr.eq] permits the application of a pointer conversion to
523 bring the pointers to a common type. */
524 if (TREE_CODE (t1) == POINTER_TYPE && TREE_CODE (t2) == POINTER_TYPE
525 && CLASS_TYPE_P (TREE_TYPE (t1))
526 && CLASS_TYPE_P (TREE_TYPE (t2))
527 && !same_type_ignoring_top_level_qualifiers_p (TREE_TYPE (t1),
530 class1 = TREE_TYPE (t1);
531 class2 = TREE_TYPE (t2);
533 if (DERIVED_FROM_P (class1, class2))
534 t2 = (build_pointer_type
535 (cp_build_qualified_type (class1, TYPE_QUALS (class2))));
536 else if (DERIVED_FROM_P (class2, class1))
537 t1 = (build_pointer_type
538 (cp_build_qualified_type (class2, TYPE_QUALS (class1))));
541 error ("%s between distinct pointer types %qT and %qT "
542 "lacks a cast", location, t1, t2);
543 return error_mark_node;
546 /* [expr.eq] permits the application of a pointer-to-member
547 conversion to change the class type of one of the types. */
548 else if (TYPE_PTR_TO_MEMBER_P (t1)
549 && !same_type_p (TYPE_PTRMEM_CLASS_TYPE (t1),
550 TYPE_PTRMEM_CLASS_TYPE (t2)))
552 class1 = TYPE_PTRMEM_CLASS_TYPE (t1);
553 class2 = TYPE_PTRMEM_CLASS_TYPE (t2);
555 if (DERIVED_FROM_P (class1, class2))
556 t1 = build_ptrmem_type (class2, TYPE_PTRMEM_POINTED_TO_TYPE (t1));
557 else if (DERIVED_FROM_P (class2, class1))
558 t2 = build_ptrmem_type (class1, TYPE_PTRMEM_POINTED_TO_TYPE (t2));
561 error ("%s between distinct pointer-to-member types %qT and %qT "
562 "lacks a cast", location, t1, t2);
563 return error_mark_node;
567 return composite_pointer_type_r (t1, t2, location);
570 /* Return the merged type of two types.
571 We assume that comptypes has already been done and returned 1;
572 if that isn't so, this may crash.
574 This just combines attributes and default arguments; any other
575 differences would cause the two types to compare unalike. */
578 merge_types (tree t1, tree t2)
580 enum tree_code code1;
581 enum tree_code code2;
584 /* Save time if the two types are the same. */
587 if (original_type (t1) == original_type (t2))
590 /* If one type is nonsense, use the other. */
591 if (t1 == error_mark_node)
593 if (t2 == error_mark_node)
596 /* Merge the attributes. */
597 attributes = (*targetm.merge_type_attributes) (t1, t2);
599 if (TYPE_PTRMEMFUNC_P (t1))
600 t1 = TYPE_PTRMEMFUNC_FN_TYPE (t1);
601 if (TYPE_PTRMEMFUNC_P (t2))
602 t2 = TYPE_PTRMEMFUNC_FN_TYPE (t2);
604 code1 = TREE_CODE (t1);
605 code2 = TREE_CODE (t2);
611 /* For two pointers, do this recursively on the target type. */
613 tree target = merge_types (TREE_TYPE (t1), TREE_TYPE (t2));
614 int quals = cp_type_quals (t1);
616 if (code1 == POINTER_TYPE)
617 t1 = build_pointer_type (target);
619 t1 = build_reference_type (target);
620 t1 = build_type_attribute_variant (t1, attributes);
621 t1 = cp_build_qualified_type (t1, quals);
623 if (TREE_CODE (target) == METHOD_TYPE)
624 t1 = build_ptrmemfunc_type (t1);
633 quals = cp_type_quals (t1);
634 pointee = merge_types (TYPE_PTRMEM_POINTED_TO_TYPE (t1),
635 TYPE_PTRMEM_POINTED_TO_TYPE (t2));
636 t1 = build_ptrmem_type (TYPE_PTRMEM_CLASS_TYPE (t1),
638 t1 = cp_build_qualified_type (t1, quals);
644 tree elt = merge_types (TREE_TYPE (t1), TREE_TYPE (t2));
645 /* Save space: see if the result is identical to one of the args. */
646 if (elt == TREE_TYPE (t1) && TYPE_DOMAIN (t1))
647 return build_type_attribute_variant (t1, attributes);
648 if (elt == TREE_TYPE (t2) && TYPE_DOMAIN (t2))
649 return build_type_attribute_variant (t2, attributes);
650 /* Merge the element types, and have a size if either arg has one. */
651 t1 = build_cplus_array_type
652 (elt, TYPE_DOMAIN (TYPE_DOMAIN (t1) ? t1 : t2));
657 /* Function types: prefer the one that specified arg types.
658 If both do, merge the arg types. Also merge the return types. */
660 tree valtype = merge_types (TREE_TYPE (t1), TREE_TYPE (t2));
661 tree p1 = TYPE_ARG_TYPES (t1);
662 tree p2 = TYPE_ARG_TYPES (t2);
665 /* Save space: see if the result is identical to one of the args. */
666 if (valtype == TREE_TYPE (t1) && ! p2)
667 return cp_build_type_attribute_variant (t1, attributes);
668 if (valtype == TREE_TYPE (t2) && ! p1)
669 return cp_build_type_attribute_variant (t2, attributes);
671 /* Simple way if one arg fails to specify argument types. */
672 if (p1 == NULL_TREE || TREE_VALUE (p1) == void_type_node)
674 rval = build_function_type (valtype, p2);
675 if ((raises = TYPE_RAISES_EXCEPTIONS (t2)))
676 rval = build_exception_variant (rval, raises);
677 return cp_build_type_attribute_variant (rval, attributes);
679 raises = TYPE_RAISES_EXCEPTIONS (t1);
680 if (p2 == NULL_TREE || TREE_VALUE (p2) == void_type_node)
682 rval = build_function_type (valtype, p1);
684 rval = build_exception_variant (rval, raises);
685 return cp_build_type_attribute_variant (rval, attributes);
688 rval = build_function_type (valtype, commonparms (p1, p2));
689 t1 = build_exception_variant (rval, raises);
695 /* Get this value the long way, since TYPE_METHOD_BASETYPE
696 is just the main variant of this. */
697 tree basetype = TREE_TYPE (TREE_VALUE (TYPE_ARG_TYPES (t2)));
698 tree raises = TYPE_RAISES_EXCEPTIONS (t1);
701 /* If this was a member function type, get back to the
702 original type of type member function (i.e., without
703 the class instance variable up front. */
704 t1 = build_function_type (TREE_TYPE (t1),
705 TREE_CHAIN (TYPE_ARG_TYPES (t1)));
706 t2 = build_function_type (TREE_TYPE (t2),
707 TREE_CHAIN (TYPE_ARG_TYPES (t2)));
708 t3 = merge_types (t1, t2);
709 t3 = build_method_type_directly (basetype, TREE_TYPE (t3),
710 TYPE_ARG_TYPES (t3));
711 t1 = build_exception_variant (t3, raises);
716 /* There is no need to merge attributes into a TYPENAME_TYPE.
717 When the type is instantiated it will have whatever
718 attributes result from the instantiation. */
723 return cp_build_type_attribute_variant (t1, attributes);
726 /* Return the common type of two types.
727 We assume that comptypes has already been done and returned 1;
728 if that isn't so, this may crash.
730 This is the type for the result of most arithmetic operations
731 if the operands have the given two types. */
734 common_type (tree t1, tree t2)
736 enum tree_code code1;
737 enum tree_code code2;
739 /* If one type is nonsense, bail. */
740 if (t1 == error_mark_node || t2 == error_mark_node)
741 return error_mark_node;
743 code1 = TREE_CODE (t1);
744 code2 = TREE_CODE (t2);
746 if ((ARITHMETIC_TYPE_P (t1) || code1 == ENUMERAL_TYPE
747 || code1 == COMPLEX_TYPE)
748 && (ARITHMETIC_TYPE_P (t2) || code2 == ENUMERAL_TYPE
749 || code2 == COMPLEX_TYPE))
750 return type_after_usual_arithmetic_conversions (t1, t2);
752 else if ((TYPE_PTR_P (t1) && TYPE_PTR_P (t2))
753 || (TYPE_PTRMEM_P (t1) && TYPE_PTRMEM_P (t2))
754 || (TYPE_PTRMEMFUNC_P (t1) && TYPE_PTRMEMFUNC_P (t2)))
755 return composite_pointer_type (t1, t2, error_mark_node, error_mark_node,
761 /* Compare two exception specifier types for exactness or subsetness, if
762 allowed. Returns false for mismatch, true for match (same, or
765 [except.spec] "If a class X ... objects of class X or any class publicly
766 and unambiguously derived from X. Similarly, if a pointer type Y * ...
767 exceptions of type Y * or that are pointers to any type publicly and
768 unambiguously derived from Y. Otherwise a function only allows exceptions
769 that have the same type ..."
770 This does not mention cv qualifiers and is different to what throw
771 [except.throw] and catch [except.catch] will do. They will ignore the
772 top level cv qualifiers, and allow qualifiers in the pointer to class
775 We implement the letter of the standard. */
778 comp_except_types (tree a, tree b, bool exact)
780 if (same_type_p (a, b))
784 if (cp_type_quals (a) || cp_type_quals (b))
787 if (TREE_CODE (a) == POINTER_TYPE
788 && TREE_CODE (b) == POINTER_TYPE)
792 if (cp_type_quals (a) || cp_type_quals (b))
796 if (TREE_CODE (a) != RECORD_TYPE
797 || TREE_CODE (b) != RECORD_TYPE)
800 if (PUBLICLY_UNIQUELY_DERIVED_P (a, b))
806 /* Return true if TYPE1 and TYPE2 are equivalent exception specifiers.
807 If EXACT is false, T2 can be stricter than T1 (according to 15.4/7),
808 otherwise it must be exact. Exception lists are unordered, but
809 we've already filtered out duplicates. Most lists will be in order,
810 we should try to make use of that. */
813 comp_except_specs (tree t1, tree t2, bool exact)
822 if (t1 == NULL_TREE) /* T1 is ... */
823 return t2 == NULL_TREE || !exact;
824 if (!TREE_VALUE (t1)) /* t1 is EMPTY */
825 return t2 != NULL_TREE && !TREE_VALUE (t2);
826 if (t2 == NULL_TREE) /* T2 is ... */
828 if (TREE_VALUE (t1) && !TREE_VALUE (t2)) /* T2 is EMPTY, T1 is not */
831 /* Neither set is ... or EMPTY, make sure each part of T2 is in T1.
832 Count how many we find, to determine exactness. For exact matching and
833 ordered T1, T2, this is an O(n) operation, otherwise its worst case is
835 for (base = t1; t2 != NULL_TREE; t2 = TREE_CHAIN (t2))
837 for (probe = base; probe != NULL_TREE; probe = TREE_CHAIN (probe))
839 tree a = TREE_VALUE (probe);
840 tree b = TREE_VALUE (t2);
842 if (comp_except_types (a, b, exact))
844 if (probe == base && exact)
845 base = TREE_CHAIN (probe);
850 if (probe == NULL_TREE)
853 return !exact || base == NULL_TREE || length == list_length (t1);
856 /* Compare the array types T1 and T2. ALLOW_REDECLARATION is true if
857 [] can match [size]. */
860 comp_array_types (tree t1, tree t2, bool allow_redeclaration)
869 /* The type of the array elements must be the same. */
870 if (!same_type_p (TREE_TYPE (t1), TREE_TYPE (t2)))
873 d1 = TYPE_DOMAIN (t1);
874 d2 = TYPE_DOMAIN (t2);
879 /* If one of the arrays is dimensionless, and the other has a
880 dimension, they are of different types. However, it is valid to
888 declarations for an array object can specify
889 array types that differ by the presence or absence of a major
890 array bound (_dcl.array_). */
892 return allow_redeclaration;
894 /* Check that the dimensions are the same. */
896 if (!cp_tree_equal (TYPE_MIN_VALUE (d1), TYPE_MIN_VALUE (d2)))
898 max1 = TYPE_MAX_VALUE (d1);
899 max2 = TYPE_MAX_VALUE (d2);
900 if (processing_template_decl && !abi_version_at_least (2)
901 && !value_dependent_expression_p (max1)
902 && !value_dependent_expression_p (max2))
904 /* With abi-1 we do not fold non-dependent array bounds, (and
905 consequently mangle them incorrectly). We must therefore
906 fold them here, to verify the domains have the same
912 if (!cp_tree_equal (max1, max2))
918 /* Return true if T1 and T2 are related as allowed by STRICT. STRICT
919 is a bitwise-or of the COMPARE_* flags. */
922 comptypes (tree t1, tree t2, int strict)
929 /* Suppress errors caused by previously reported errors. */
930 if (t1 == error_mark_node || t2 == error_mark_node)
933 gcc_assert (TYPE_P (t1) && TYPE_P (t2));
935 /* TYPENAME_TYPEs should be resolved if the qualifying scope is the
936 current instantiation. */
937 if (TREE_CODE (t1) == TYPENAME_TYPE)
939 tree resolved = resolve_typename_type (t1, /*only_current_p=*/true);
941 if (resolved != error_mark_node)
945 if (TREE_CODE (t2) == TYPENAME_TYPE)
947 tree resolved = resolve_typename_type (t2, /*only_current_p=*/true);
949 if (resolved != error_mark_node)
953 /* If either type is the internal version of sizetype, use the
955 if (TREE_CODE (t1) == INTEGER_TYPE && TYPE_IS_SIZETYPE (t1)
956 && TYPE_ORIG_SIZE_TYPE (t1))
957 t1 = TYPE_ORIG_SIZE_TYPE (t1);
959 if (TREE_CODE (t2) == INTEGER_TYPE && TYPE_IS_SIZETYPE (t2)
960 && TYPE_ORIG_SIZE_TYPE (t2))
961 t2 = TYPE_ORIG_SIZE_TYPE (t2);
963 if (TYPE_PTRMEMFUNC_P (t1))
964 t1 = TYPE_PTRMEMFUNC_FN_TYPE (t1);
965 if (TYPE_PTRMEMFUNC_P (t2))
966 t2 = TYPE_PTRMEMFUNC_FN_TYPE (t2);
968 /* Different classes of types can't be compatible. */
969 if (TREE_CODE (t1) != TREE_CODE (t2))
972 /* Qualifiers must match. For array types, we will check when we
973 recur on the array element types. */
974 if (TREE_CODE (t1) != ARRAY_TYPE
975 && TYPE_QUALS (t1) != TYPE_QUALS (t2))
977 if (TYPE_FOR_JAVA (t1) != TYPE_FOR_JAVA (t2))
980 /* Allow for two different type nodes which have essentially the same
981 definition. Note that we already checked for equality of the type
982 qualifiers (just above). */
984 if (TREE_CODE (t1) != ARRAY_TYPE
985 && TYPE_MAIN_VARIANT (t1) == TYPE_MAIN_VARIANT (t2))
988 if (!(*targetm.comp_type_attributes) (t1, t2))
991 switch (TREE_CODE (t1))
993 case TEMPLATE_TEMPLATE_PARM:
994 case BOUND_TEMPLATE_TEMPLATE_PARM:
995 if (TEMPLATE_TYPE_IDX (t1) != TEMPLATE_TYPE_IDX (t2)
996 || TEMPLATE_TYPE_LEVEL (t1) != TEMPLATE_TYPE_LEVEL (t2))
998 if (!comp_template_parms
999 (DECL_TEMPLATE_PARMS (TEMPLATE_TEMPLATE_PARM_TEMPLATE_DECL (t1)),
1000 DECL_TEMPLATE_PARMS (TEMPLATE_TEMPLATE_PARM_TEMPLATE_DECL (t2))))
1002 if (TREE_CODE (t1) == TEMPLATE_TEMPLATE_PARM)
1004 /* Don't check inheritance. */
1005 strict = COMPARE_STRICT;
1010 if (TYPE_TEMPLATE_INFO (t1) && TYPE_TEMPLATE_INFO (t2)
1011 && (TYPE_TI_TEMPLATE (t1) == TYPE_TI_TEMPLATE (t2)
1012 || TREE_CODE (t1) == BOUND_TEMPLATE_TEMPLATE_PARM)
1013 && comp_template_args (TYPE_TI_ARGS (t1), TYPE_TI_ARGS (t2)))
1016 if ((strict & COMPARE_BASE) && DERIVED_FROM_P (t1, t2))
1018 else if ((strict & COMPARE_DERIVED) && DERIVED_FROM_P (t2, t1))
1021 /* We may be dealing with Objective-C instances... */
1022 if (TREE_CODE (t1) == RECORD_TYPE
1023 && (retval = objc_comptypes (t1, t2, 0) >= 0))
1025 /* ...but fall through if we are not. */
1030 if (!comptypes (TYPE_OFFSET_BASETYPE (t1), TYPE_OFFSET_BASETYPE (t2),
1031 strict & ~COMPARE_REDECLARATION))
1033 return same_type_p (TREE_TYPE (t1), TREE_TYPE (t2));
1036 case REFERENCE_TYPE:
1037 return TYPE_MODE (t1) == TYPE_MODE (t2)
1038 && TYPE_REF_CAN_ALIAS_ALL (t1) == TYPE_REF_CAN_ALIAS_ALL (t2)
1039 && same_type_p (TREE_TYPE (t1), TREE_TYPE (t2));
1043 if (!same_type_p (TREE_TYPE (t1), TREE_TYPE (t2)))
1045 return compparms (TYPE_ARG_TYPES (t1), TYPE_ARG_TYPES (t2));
1048 /* Target types must match incl. qualifiers. */
1049 return comp_array_types (t1, t2, !!(strict & COMPARE_REDECLARATION));
1051 case TEMPLATE_TYPE_PARM:
1052 return (TEMPLATE_TYPE_IDX (t1) == TEMPLATE_TYPE_IDX (t2)
1053 && TEMPLATE_TYPE_LEVEL (t1) == TEMPLATE_TYPE_LEVEL (t2));
1056 if (!cp_tree_equal (TYPENAME_TYPE_FULLNAME (t1),
1057 TYPENAME_TYPE_FULLNAME (t2)))
1059 return same_type_p (TYPE_CONTEXT (t1), TYPE_CONTEXT (t2));
1061 case UNBOUND_CLASS_TEMPLATE:
1062 if (!cp_tree_equal (TYPE_IDENTIFIER (t1), TYPE_IDENTIFIER (t2)))
1064 return same_type_p (TYPE_CONTEXT (t1), TYPE_CONTEXT (t2));
1067 return same_type_p (TREE_TYPE (t1), TREE_TYPE (t2));
1070 return TYPE_VECTOR_SUBPARTS (t1) == TYPE_VECTOR_SUBPARTS (t2)
1071 && same_type_p (TREE_TYPE (t1), TREE_TYPE (t2));
1080 /* Returns 1 if TYPE1 is at least as qualified as TYPE2. */
1083 at_least_as_qualified_p (tree type1, tree type2)
1085 int q1 = cp_type_quals (type1);
1086 int q2 = cp_type_quals (type2);
1088 /* All qualifiers for TYPE2 must also appear in TYPE1. */
1089 return (q1 & q2) == q2;
1092 /* Returns 1 if TYPE1 is more qualified than TYPE2. */
1095 more_qualified_p (tree type1, tree type2)
1097 int q1 = cp_type_quals (type1);
1098 int q2 = cp_type_quals (type2);
1100 return q1 != q2 && (q1 & q2) == q2;
1103 /* Returns 1 if TYPE1 is more cv-qualified than TYPE2, -1 if TYPE2 is
1104 more cv-qualified that TYPE1, and 0 otherwise. */
1107 comp_cv_qualification (tree type1, tree type2)
1109 int q1 = cp_type_quals (type1);
1110 int q2 = cp_type_quals (type2);
1115 if ((q1 & q2) == q2)
1117 else if ((q1 & q2) == q1)
1123 /* Returns 1 if the cv-qualification signature of TYPE1 is a proper
1124 subset of the cv-qualification signature of TYPE2, and the types
1125 are similar. Returns -1 if the other way 'round, and 0 otherwise. */
1128 comp_cv_qual_signature (tree type1, tree type2)
1130 if (comp_ptr_ttypes_real (type2, type1, -1))
1132 else if (comp_ptr_ttypes_real (type1, type2, -1))
1138 /* If two types share a common base type, return that basetype.
1139 If there is not a unique most-derived base type, this function
1140 returns ERROR_MARK_NODE. */
1143 common_base_type (tree tt1, tree tt2)
1145 tree best = NULL_TREE;
1148 /* If one is a baseclass of another, that's good enough. */
1149 if (UNIQUELY_DERIVED_FROM_P (tt1, tt2))
1151 if (UNIQUELY_DERIVED_FROM_P (tt2, tt1))
1154 /* Otherwise, try to find a unique baseclass of TT1
1155 that is shared by TT2, and follow that down. */
1156 for (i = BINFO_N_BASE_BINFOS (TYPE_BINFO (tt1))-1; i >= 0; i--)
1158 tree basetype = BINFO_TYPE (BINFO_BASE_BINFO (TYPE_BINFO (tt1), i));
1159 tree trial = common_base_type (basetype, tt2);
1163 if (trial == error_mark_node)
1165 if (best == NULL_TREE)
1167 else if (best != trial)
1168 return error_mark_node;
1173 for (i = BINFO_N_BASE_BINFOS (TYPE_BINFO (tt2))-1; i >= 0; i--)
1175 tree basetype = BINFO_TYPE (BINFO_BASE_BINFO (TYPE_BINFO (tt2), i));
1176 tree trial = common_base_type (tt1, basetype);
1180 if (trial == error_mark_node)
1182 if (best == NULL_TREE)
1184 else if (best != trial)
1185 return error_mark_node;
1191 /* Subroutines of `comptypes'. */
1193 /* Return true if two parameter type lists PARMS1 and PARMS2 are
1194 equivalent in the sense that functions with those parameter types
1195 can have equivalent types. The two lists must be equivalent,
1196 element by element. */
1199 compparms (tree parms1, tree parms2)
1203 /* An unspecified parmlist matches any specified parmlist
1204 whose argument types don't need default promotions. */
1206 for (t1 = parms1, t2 = parms2;
1208 t1 = TREE_CHAIN (t1), t2 = TREE_CHAIN (t2))
1210 /* If one parmlist is shorter than the other,
1211 they fail to match. */
1214 if (!same_type_p (TREE_VALUE (t1), TREE_VALUE (t2)))
1221 /* Process a sizeof or alignof expression where the operand is a
1225 cxx_sizeof_or_alignof_type (tree type, enum tree_code op, bool complain)
1227 enum tree_code type_code;
1229 const char *op_name;
1231 gcc_assert (op == SIZEOF_EXPR || op == ALIGNOF_EXPR);
1232 if (type == error_mark_node)
1233 return error_mark_node;
1235 if (processing_template_decl)
1237 value = build_min (op, size_type_node, type);
1238 TREE_READONLY (value) = 1;
1242 op_name = operator_name_info[(int) op].name;
1244 type = non_reference (type);
1245 type_code = TREE_CODE (type);
1247 if (type_code == METHOD_TYPE)
1249 if (complain && (pedantic || warn_pointer_arith))
1250 pedwarn ("invalid application of %qs to a member function", op_name);
1251 value = size_one_node;
1254 value = c_sizeof_or_alignof_type (complete_type (type), op, complain);
1259 /* Process a sizeof or alignof expression where the operand is an
1263 cxx_sizeof_or_alignof_expr (tree e, enum tree_code op)
1265 const char *op_name = operator_name_info[(int) op].name;
1267 if (e == error_mark_node)
1268 return error_mark_node;
1270 if (processing_template_decl)
1272 e = build_min (op, size_type_node, e);
1273 TREE_SIDE_EFFECTS (e) = 0;
1274 TREE_READONLY (e) = 1;
1279 if (TREE_CODE (e) == COMPONENT_REF
1280 && TREE_CODE (TREE_OPERAND (e, 1)) == FIELD_DECL
1281 && DECL_C_BIT_FIELD (TREE_OPERAND (e, 1)))
1283 error ("invalid application of %qs to a bit-field", op_name);
1286 else if (is_overloaded_fn (e))
1288 pedwarn ("ISO C++ forbids applying %qs to an expression of "
1289 "function type", op_name);
1292 else if (type_unknown_p (e))
1294 cxx_incomplete_type_error (e, TREE_TYPE (e));
1300 return cxx_sizeof_or_alignof_type (e, op, true);
1304 /* EXPR is being used in a context that is not a function call.
1309 The expression can be used only as the left-hand operand of a
1310 member function call.
1312 [expr.mptr.operator]
1314 If the result of .* or ->* is a function, then that result can be
1315 used only as the operand for the function call operator ().
1317 by issuing an error message if appropriate. Returns true iff EXPR
1318 violates these rules. */
1321 invalid_nonstatic_memfn_p (tree expr)
1323 if (TREE_CODE (TREE_TYPE (expr)) == METHOD_TYPE)
1325 error ("invalid use of non-static member function");
1331 /* Perform the conversions in [expr] that apply when an lvalue appears
1332 in an rvalue context: the lvalue-to-rvalue, array-to-pointer, and
1333 function-to-pointer conversions.
1335 In addition manifest constants are replaced by their values. */
1338 decay_conversion (tree exp)
1341 enum tree_code code;
1343 type = TREE_TYPE (exp);
1344 code = TREE_CODE (type);
1346 if (type == error_mark_node)
1347 return error_mark_node;
1349 if (type_unknown_p (exp))
1351 cxx_incomplete_type_error (exp, TREE_TYPE (exp));
1352 return error_mark_node;
1355 exp = integral_constant_value (exp);
1357 /* build_c_cast puts on a NOP_EXPR to make the result not an lvalue.
1358 Leave such NOP_EXPRs, since RHS is being used in non-lvalue context. */
1360 if (code == VOID_TYPE)
1362 error ("void value not ignored as it ought to be");
1363 return error_mark_node;
1365 if (invalid_nonstatic_memfn_p (exp))
1366 return error_mark_node;
1367 if (code == FUNCTION_TYPE || is_overloaded_fn (exp))
1368 return build_unary_op (ADDR_EXPR, exp, 0);
1369 if (code == ARRAY_TYPE)
1374 if (TREE_CODE (exp) == INDIRECT_REF)
1375 return build_nop (build_pointer_type (TREE_TYPE (type)),
1376 TREE_OPERAND (exp, 0));
1378 if (TREE_CODE (exp) == COMPOUND_EXPR)
1380 tree op1 = decay_conversion (TREE_OPERAND (exp, 1));
1381 return build2 (COMPOUND_EXPR, TREE_TYPE (op1),
1382 TREE_OPERAND (exp, 0), op1);
1386 && ! (TREE_CODE (exp) == CONSTRUCTOR && TREE_STATIC (exp)))
1388 error ("invalid use of non-lvalue array");
1389 return error_mark_node;
1392 ptrtype = build_pointer_type (TREE_TYPE (type));
1394 if (TREE_CODE (exp) == VAR_DECL)
1396 if (!cxx_mark_addressable (exp))
1397 return error_mark_node;
1398 adr = build_nop (ptrtype, build_address (exp));
1401 /* This way is better for a COMPONENT_REF since it can
1402 simplify the offset for a component. */
1403 adr = build_unary_op (ADDR_EXPR, exp, 1);
1404 return cp_convert (ptrtype, adr);
1407 /* [basic.lval]: Class rvalues can have cv-qualified types; non-class
1408 rvalues always have cv-unqualified types. */
1409 if (! CLASS_TYPE_P (type))
1410 exp = cp_convert (TYPE_MAIN_VARIANT (type), exp);
1416 default_conversion (tree exp)
1418 exp = decay_conversion (exp);
1420 if (INTEGRAL_OR_ENUMERATION_TYPE_P (TREE_TYPE (exp)))
1421 exp = perform_integral_promotions (exp);
1426 /* EXPR is an expression with an integral or enumeration type.
1427 Perform the integral promotions in [conv.prom], and return the
1431 perform_integral_promotions (tree expr)
1436 type = TREE_TYPE (expr);
1437 gcc_assert (INTEGRAL_OR_ENUMERATION_TYPE_P (type));
1438 promoted_type = type_promotes_to (type);
1439 if (type != promoted_type)
1440 expr = cp_convert (promoted_type, expr);
1444 /* Take the address of an inline function without setting TREE_ADDRESSABLE
1448 inline_conversion (tree exp)
1450 if (TREE_CODE (exp) == FUNCTION_DECL)
1451 exp = build1 (ADDR_EXPR, build_pointer_type (TREE_TYPE (exp)), exp);
1456 /* Returns nonzero iff exp is a STRING_CST or the result of applying
1457 decay_conversion to one. */
1460 string_conv_p (tree totype, tree exp, int warn)
1464 if (! flag_const_strings || TREE_CODE (totype) != POINTER_TYPE)
1467 t = TREE_TYPE (totype);
1468 if (!same_type_p (t, char_type_node)
1469 && !same_type_p (t, wchar_type_node))
1472 if (TREE_CODE (exp) == STRING_CST)
1474 /* Make sure that we don't try to convert between char and wchar_t. */
1475 if (!same_type_p (TYPE_MAIN_VARIANT (TREE_TYPE (TREE_TYPE (exp))), t))
1480 /* Is this a string constant which has decayed to 'const char *'? */
1481 t = build_pointer_type (build_qualified_type (t, TYPE_QUAL_CONST));
1482 if (!same_type_p (TREE_TYPE (exp), t))
1485 if (TREE_CODE (exp) != ADDR_EXPR
1486 || TREE_CODE (TREE_OPERAND (exp, 0)) != STRING_CST)
1490 /* This warning is not very useful, as it complains about printf. */
1491 if (warn && warn_write_strings)
1492 warning ("deprecated conversion from string constant to %qT'", totype);
1497 /* Given a COND_EXPR, MIN_EXPR, or MAX_EXPR in T, return it in a form that we
1498 can, for example, use as an lvalue. This code used to be in
1499 unary_complex_lvalue, but we needed it to deal with `a = (d == c) ? b : c'
1500 expressions, where we're dealing with aggregates. But now it's again only
1501 called from unary_complex_lvalue. The case (in particular) that led to
1502 this was with CODE == ADDR_EXPR, since it's not an lvalue when we'd
1506 rationalize_conditional_expr (enum tree_code code, tree t)
1508 /* For MIN_EXPR or MAX_EXPR, fold-const.c has arranged things so that
1509 the first operand is always the one to be used if both operands
1510 are equal, so we know what conditional expression this used to be. */
1511 if (TREE_CODE (t) == MIN_EXPR || TREE_CODE (t) == MAX_EXPR)
1513 /* The following code is incorrect if either operand side-effects. */
1514 gcc_assert (!TREE_SIDE_EFFECTS (TREE_OPERAND (t, 0))
1515 && !TREE_SIDE_EFFECTS (TREE_OPERAND (t, 1)));
1517 build_conditional_expr (build_x_binary_op ((TREE_CODE (t) == MIN_EXPR
1518 ? LE_EXPR : GE_EXPR),
1519 TREE_OPERAND (t, 0),
1520 TREE_OPERAND (t, 1),
1521 /*overloaded_p=*/NULL),
1522 build_unary_op (code, TREE_OPERAND (t, 0), 0),
1523 build_unary_op (code, TREE_OPERAND (t, 1), 0));
1527 build_conditional_expr (TREE_OPERAND (t, 0),
1528 build_unary_op (code, TREE_OPERAND (t, 1), 0),
1529 build_unary_op (code, TREE_OPERAND (t, 2), 0));
1532 /* Given the TYPE of an anonymous union field inside T, return the
1533 FIELD_DECL for the field. If not found return NULL_TREE. Because
1534 anonymous unions can nest, we must also search all anonymous unions
1535 that are directly reachable. */
1538 lookup_anon_field (tree t, tree type)
1542 for (field = TYPE_FIELDS (t); field; field = TREE_CHAIN (field))
1544 if (TREE_STATIC (field))
1546 if (TREE_CODE (field) != FIELD_DECL || DECL_ARTIFICIAL (field))
1549 /* If we find it directly, return the field. */
1550 if (DECL_NAME (field) == NULL_TREE
1551 && type == TYPE_MAIN_VARIANT (TREE_TYPE (field)))
1556 /* Otherwise, it could be nested, search harder. */
1557 if (DECL_NAME (field) == NULL_TREE
1558 && ANON_AGGR_TYPE_P (TREE_TYPE (field)))
1560 tree subfield = lookup_anon_field (TREE_TYPE (field), type);
1568 /* Build an expression representing OBJECT.MEMBER. OBJECT is an
1569 expression; MEMBER is a DECL or baselink. If ACCESS_PATH is
1570 non-NULL, it indicates the path to the base used to name MEMBER.
1571 If PRESERVE_REFERENCE is true, the expression returned will have
1572 REFERENCE_TYPE if the MEMBER does. Otherwise, the expression
1573 returned will have the type referred to by the reference.
1575 This function does not perform access control; that is either done
1576 earlier by the parser when the name of MEMBER is resolved to MEMBER
1577 itself, or later when overload resolution selects one of the
1578 functions indicated by MEMBER. */
1581 build_class_member_access_expr (tree object, tree member,
1582 tree access_path, bool preserve_reference)
1586 tree result = NULL_TREE;
1588 if (object == error_mark_node || member == error_mark_node)
1589 return error_mark_node;
1591 if (TREE_CODE (member) == PSEUDO_DTOR_EXPR)
1594 gcc_assert (DECL_P (member) || BASELINK_P (member));
1598 The type of the first expression shall be "class object" (of a
1600 object_type = TREE_TYPE (object);
1601 if (!currently_open_class (object_type)
1602 && !complete_type_or_else (object_type, object))
1603 return error_mark_node;
1604 if (!CLASS_TYPE_P (object_type))
1606 error ("request for member %qD in %qE, which is of non-class type %qT",
1607 member, object, object_type);
1608 return error_mark_node;
1611 /* The standard does not seem to actually say that MEMBER must be a
1612 member of OBJECT_TYPE. However, that is clearly what is
1614 if (DECL_P (member))
1616 member_scope = DECL_CLASS_CONTEXT (member);
1618 if (TREE_DEPRECATED (member))
1619 warn_deprecated_use (member);
1622 member_scope = BINFO_TYPE (BASELINK_BINFO (member));
1623 /* If MEMBER is from an anonymous aggregate, MEMBER_SCOPE will
1624 presently be the anonymous union. Go outwards until we find a
1625 type related to OBJECT_TYPE. */
1626 while (ANON_AGGR_TYPE_P (member_scope)
1627 && !same_type_ignoring_top_level_qualifiers_p (member_scope,
1629 member_scope = TYPE_CONTEXT (member_scope);
1630 if (!member_scope || !DERIVED_FROM_P (member_scope, object_type))
1632 if (TREE_CODE (member) == FIELD_DECL)
1633 error ("invalid use of nonstatic data member %qE", member);
1635 error ("%qD is not a member of %qT", member, object_type);
1636 return error_mark_node;
1639 /* Transform `(a, b).x' into `(*(a, &b)).x', `(a ? b : c).x' into
1640 `(*(a ? &b : &c)).x', and so on. A COND_EXPR is only an lvalue
1641 in the frontend; only _DECLs and _REFs are lvalues in the backend. */
1643 tree temp = unary_complex_lvalue (ADDR_EXPR, object);
1645 object = build_indirect_ref (temp, NULL);
1648 /* In [expr.ref], there is an explicit list of the valid choices for
1649 MEMBER. We check for each of those cases here. */
1650 if (TREE_CODE (member) == VAR_DECL)
1652 /* A static data member. */
1654 /* If OBJECT has side-effects, they are supposed to occur. */
1655 if (TREE_SIDE_EFFECTS (object))
1656 result = build2 (COMPOUND_EXPR, TREE_TYPE (result), object, result);
1658 else if (TREE_CODE (member) == FIELD_DECL)
1660 /* A non-static data member. */
1665 null_object_p = (TREE_CODE (object) == INDIRECT_REF
1666 && integer_zerop (TREE_OPERAND (object, 0)));
1668 /* Convert OBJECT to the type of MEMBER. */
1669 if (!same_type_p (TYPE_MAIN_VARIANT (object_type),
1670 TYPE_MAIN_VARIANT (member_scope)))
1675 binfo = lookup_base (access_path ? access_path : object_type,
1676 member_scope, ba_unique, &kind);
1677 if (binfo == error_mark_node)
1678 return error_mark_node;
1680 /* It is invalid to try to get to a virtual base of a
1681 NULL object. The most common cause is invalid use of
1683 if (null_object_p && kind == bk_via_virtual)
1685 error ("invalid access to non-static data member %qD of "
1688 error ("(perhaps the %<offsetof%> macro was used incorrectly)");
1689 return error_mark_node;
1692 /* Convert to the base. */
1693 object = build_base_path (PLUS_EXPR, object, binfo,
1695 /* If we found the base successfully then we should be able
1696 to convert to it successfully. */
1697 gcc_assert (object != error_mark_node);
1700 /* Complain about other invalid uses of offsetof, even though they will
1701 give the right answer. Note that we complain whether or not they
1702 actually used the offsetof macro, since there's no way to know at this
1703 point. So we just give a warning, instead of a pedwarn. */
1704 /* Do not produce this warning for base class field references, because
1705 we know for a fact that didn't come from offsetof. This does occur
1706 in various testsuite cases where a null object is passed where a
1707 vtable access is required. */
1708 if (null_object_p && warn_invalid_offsetof
1709 && CLASSTYPE_NON_POD_P (object_type)
1710 && !DECL_FIELD_IS_BASE (member)
1711 && !skip_evaluation)
1713 warning ("invalid access to non-static data member %qD of NULL object",
1715 warning ("(perhaps the %<offsetof%> macro was used incorrectly)");
1718 /* If MEMBER is from an anonymous aggregate, we have converted
1719 OBJECT so that it refers to the class containing the
1720 anonymous union. Generate a reference to the anonymous union
1721 itself, and recur to find MEMBER. */
1722 if (ANON_AGGR_TYPE_P (DECL_CONTEXT (member))
1723 /* When this code is called from build_field_call, the
1724 object already has the type of the anonymous union.
1725 That is because the COMPONENT_REF was already
1726 constructed, and was then disassembled before calling
1727 build_field_call. After the function-call code is
1728 cleaned up, this waste can be eliminated. */
1729 && (!same_type_ignoring_top_level_qualifiers_p
1730 (TREE_TYPE (object), DECL_CONTEXT (member))))
1732 tree anonymous_union;
1734 anonymous_union = lookup_anon_field (TREE_TYPE (object),
1735 DECL_CONTEXT (member));
1736 object = build_class_member_access_expr (object,
1738 /*access_path=*/NULL_TREE,
1739 preserve_reference);
1742 /* Compute the type of the field, as described in [expr.ref]. */
1743 type_quals = TYPE_UNQUALIFIED;
1744 member_type = TREE_TYPE (member);
1745 if (TREE_CODE (member_type) != REFERENCE_TYPE)
1747 type_quals = (cp_type_quals (member_type)
1748 | cp_type_quals (object_type));
1750 /* A field is const (volatile) if the enclosing object, or the
1751 field itself, is const (volatile). But, a mutable field is
1752 not const, even within a const object. */
1753 if (DECL_MUTABLE_P (member))
1754 type_quals &= ~TYPE_QUAL_CONST;
1755 member_type = cp_build_qualified_type (member_type, type_quals);
1758 result = build3 (COMPONENT_REF, member_type, object, member,
1760 result = fold_if_not_in_template (result);
1762 /* Mark the expression const or volatile, as appropriate. Even
1763 though we've dealt with the type above, we still have to mark the
1764 expression itself. */
1765 if (type_quals & TYPE_QUAL_CONST)
1766 TREE_READONLY (result) = 1;
1767 else if (type_quals & TYPE_QUAL_VOLATILE)
1768 TREE_THIS_VOLATILE (result) = 1;
1770 else if (BASELINK_P (member))
1772 /* The member is a (possibly overloaded) member function. */
1776 /* If the MEMBER is exactly one static member function, then we
1777 know the type of the expression. Otherwise, we must wait
1778 until overload resolution has been performed. */
1779 functions = BASELINK_FUNCTIONS (member);
1780 if (TREE_CODE (functions) == FUNCTION_DECL
1781 && DECL_STATIC_FUNCTION_P (functions))
1782 type = TREE_TYPE (functions);
1784 type = unknown_type_node;
1785 /* Note that we do not convert OBJECT to the BASELINK_BINFO
1786 base. That will happen when the function is called. */
1787 result = build3 (COMPONENT_REF, type, object, member, NULL_TREE);
1789 else if (TREE_CODE (member) == CONST_DECL)
1791 /* The member is an enumerator. */
1793 /* If OBJECT has side-effects, they are supposed to occur. */
1794 if (TREE_SIDE_EFFECTS (object))
1795 result = build2 (COMPOUND_EXPR, TREE_TYPE (result),
1800 error ("invalid use of %qD", member);
1801 return error_mark_node;
1804 if (!preserve_reference)
1807 If E2 is declared to have type "reference to T", then ... the
1808 type of E1.E2 is T. */
1809 result = convert_from_reference (result);
1814 /* Return the destructor denoted by OBJECT.SCOPE::~DTOR_NAME, or, if
1815 SCOPE is NULL, by OBJECT.~DTOR_NAME. */
1818 lookup_destructor (tree object, tree scope, tree dtor_name)
1820 tree object_type = TREE_TYPE (object);
1821 tree dtor_type = TREE_OPERAND (dtor_name, 0);
1824 if (scope && !check_dtor_name (scope, dtor_name))
1826 error ("qualified type %qT does not match destructor name ~%qT",
1828 return error_mark_node;
1830 if (!DERIVED_FROM_P (dtor_type, TYPE_MAIN_VARIANT (object_type)))
1832 error ("the type being destroyed is %qT, but the destructor refers to %qT",
1833 TYPE_MAIN_VARIANT (object_type), dtor_type);
1834 return error_mark_node;
1836 if (!TYPE_HAS_DESTRUCTOR (dtor_type))
1837 return build3 (PSEUDO_DTOR_EXPR, void_type_node, object, scope,
1839 expr = lookup_member (dtor_type, complete_dtor_identifier,
1840 /*protect=*/1, /*want_type=*/false);
1841 expr = (adjust_result_of_qualified_name_lookup
1842 (expr, dtor_type, object_type));
1846 /* This function is called by the parser to process a class member
1847 access expression of the form OBJECT.NAME. NAME is a node used by
1848 the parser to represent a name; it is not yet a DECL. It may,
1849 however, be a BASELINK where the BASELINK_FUNCTIONS is a
1850 TEMPLATE_ID_EXPR. Templates must be looked up by the parser, and
1851 there is no reason to do the lookup twice, so the parser keeps the
1855 finish_class_member_access_expr (tree object, tree name)
1860 tree access_path = NULL_TREE;
1861 tree orig_object = object;
1862 tree orig_name = name;
1864 if (object == error_mark_node || name == error_mark_node)
1865 return error_mark_node;
1867 object_type = TREE_TYPE (object);
1869 if (processing_template_decl)
1871 if (/* If OBJECT_TYPE is dependent, so is OBJECT.NAME. */
1872 dependent_type_p (object_type)
1873 /* If NAME is just an IDENTIFIER_NODE, then the expression
1875 || TREE_CODE (object) == IDENTIFIER_NODE
1876 /* If NAME is "f<args>", where either 'f' or 'args' is
1877 dependent, then the expression is dependent. */
1878 || (TREE_CODE (name) == TEMPLATE_ID_EXPR
1879 && dependent_template_id_p (TREE_OPERAND (name, 0),
1880 TREE_OPERAND (name, 1)))
1881 /* If NAME is "T::X" where "T" is dependent, then the
1882 expression is dependent. */
1883 || (TREE_CODE (name) == SCOPE_REF
1884 && TYPE_P (TREE_OPERAND (name, 0))
1885 && dependent_type_p (TREE_OPERAND (name, 0))))
1886 return build_min_nt (COMPONENT_REF, object, name, NULL_TREE);
1887 object = build_non_dependent_expr (object);
1892 The type of the first expression shall be "class object" (of a
1894 if (!currently_open_class (object_type)
1895 && !complete_type_or_else (object_type, object))
1896 return error_mark_node;
1897 if (!CLASS_TYPE_P (object_type))
1899 error ("request for member %qD in %qE, which is of non-class type %qT",
1900 name, object, object_type);
1901 return error_mark_node;
1904 if (BASELINK_P (name))
1906 /* A member function that has already been looked up. */
1907 gcc_assert (TREE_CODE (BASELINK_FUNCTIONS (name)) == TEMPLATE_ID_EXPR);
1912 bool is_template_id = false;
1913 tree template_args = NULL_TREE;
1916 if (TREE_CODE (name) == TEMPLATE_ID_EXPR)
1918 is_template_id = true;
1919 template_args = TREE_OPERAND (name, 1);
1920 name = TREE_OPERAND (name, 0);
1922 if (TREE_CODE (name) == OVERLOAD)
1923 name = DECL_NAME (get_first_fn (name));
1924 else if (DECL_P (name))
1925 name = DECL_NAME (name);
1928 if (TREE_CODE (name) == SCOPE_REF)
1930 /* A qualified name. The qualifying class or namespace `S' has
1931 already been looked up; it is either a TYPE or a
1932 NAMESPACE_DECL. The member name is either an IDENTIFIER_NODE
1933 or a BIT_NOT_EXPR. */
1934 scope = TREE_OPERAND (name, 0);
1935 name = TREE_OPERAND (name, 1);
1936 gcc_assert (CLASS_TYPE_P (scope)
1937 || TREE_CODE (scope) == NAMESPACE_DECL);
1938 gcc_assert (TREE_CODE (name) == IDENTIFIER_NODE
1939 || TREE_CODE (name) == BIT_NOT_EXPR);
1941 /* If SCOPE is a namespace, then the qualified name does not
1942 name a member of OBJECT_TYPE. */
1943 if (TREE_CODE (scope) == NAMESPACE_DECL)
1945 error ("%<%D::%D%> is not a member of %qT",
1946 scope, name, object_type);
1947 return error_mark_node;
1950 /* Find the base of OBJECT_TYPE corresponding to SCOPE. */
1951 access_path = lookup_base (object_type, scope, ba_check, NULL);
1952 if (access_path == error_mark_node)
1953 return error_mark_node;
1956 error ("%qT is not a base of %qT", scope, object_type);
1957 return error_mark_node;
1963 access_path = object_type;
1966 if (TREE_CODE (name) == BIT_NOT_EXPR)
1967 member = lookup_destructor (object, scope, name);
1970 /* Look up the member. */
1971 member = lookup_member (access_path, name, /*protect=*/1,
1972 /*want_type=*/false);
1973 if (member == NULL_TREE)
1975 error ("%qD has no member named %qE", object_type, name);
1976 return error_mark_node;
1978 if (member == error_mark_node)
1979 return error_mark_node;
1984 tree template = member;
1986 if (BASELINK_P (template))
1987 template = lookup_template_function (template, template_args);
1990 error ("%qD is not a member template function", name);
1991 return error_mark_node;
1996 if (TREE_DEPRECATED (member))
1997 warn_deprecated_use (member);
1999 expr = build_class_member_access_expr (object, member, access_path,
2000 /*preserve_reference=*/false);
2001 if (processing_template_decl && expr != error_mark_node)
2002 return build_min_non_dep (COMPONENT_REF, expr,
2003 orig_object, orig_name, NULL_TREE);
2007 /* Return an expression for the MEMBER_NAME field in the internal
2008 representation of PTRMEM, a pointer-to-member function. (Each
2009 pointer-to-member function type gets its own RECORD_TYPE so it is
2010 more convenient to access the fields by name than by FIELD_DECL.)
2011 This routine converts the NAME to a FIELD_DECL and then creates the
2012 node for the complete expression. */
2015 build_ptrmemfunc_access_expr (tree ptrmem, tree member_name)
2021 /* This code is a stripped down version of
2022 build_class_member_access_expr. It does not work to use that
2023 routine directly because it expects the object to be of class
2025 ptrmem_type = TREE_TYPE (ptrmem);
2026 gcc_assert (TYPE_PTRMEMFUNC_P (ptrmem_type));
2027 member = lookup_member (ptrmem_type, member_name, /*protect=*/0,
2028 /*want_type=*/false);
2029 member_type = cp_build_qualified_type (TREE_TYPE (member),
2030 cp_type_quals (ptrmem_type));
2031 return fold (build3 (COMPONENT_REF, member_type,
2032 ptrmem, member, NULL_TREE));
2035 /* Given an expression PTR for a pointer, return an expression
2036 for the value pointed to.
2037 ERRORSTRING is the name of the operator to appear in error messages.
2039 This function may need to overload OPERATOR_FNNAME.
2040 Must also handle REFERENCE_TYPEs for C++. */
2043 build_x_indirect_ref (tree expr, const char *errorstring)
2045 tree orig_expr = expr;
2048 if (processing_template_decl)
2050 if (type_dependent_expression_p (expr))
2051 return build_min_nt (INDIRECT_REF, expr);
2052 expr = build_non_dependent_expr (expr);
2055 rval = build_new_op (INDIRECT_REF, LOOKUP_NORMAL, expr, NULL_TREE,
2056 NULL_TREE, /*overloaded_p=*/NULL);
2058 rval = build_indirect_ref (expr, errorstring);
2060 if (processing_template_decl && rval != error_mark_node)
2061 return build_min_non_dep (INDIRECT_REF, rval, orig_expr);
2067 build_indirect_ref (tree ptr, const char *errorstring)
2071 if (ptr == error_mark_node)
2072 return error_mark_node;
2074 if (ptr == current_class_ptr)
2075 return current_class_ref;
2077 pointer = (TREE_CODE (TREE_TYPE (ptr)) == REFERENCE_TYPE
2078 ? ptr : decay_conversion (ptr));
2079 type = TREE_TYPE (pointer);
2081 if (POINTER_TYPE_P (type))
2085 If the type of the expression is "pointer to T," the type
2086 of the result is "T."
2088 We must use the canonical variant because certain parts of
2089 the back end, like fold, do pointer comparisons between
2091 tree t = canonical_type_variant (TREE_TYPE (type));
2093 if (VOID_TYPE_P (t))
2095 /* A pointer to incomplete type (other than cv void) can be
2096 dereferenced [expr.unary.op]/1 */
2097 error ("%qT is not a pointer-to-object type", type);
2098 return error_mark_node;
2100 else if (TREE_CODE (pointer) == ADDR_EXPR
2101 && same_type_p (t, TREE_TYPE (TREE_OPERAND (pointer, 0))))
2102 /* The POINTER was something like `&x'. We simplify `*&x' to
2104 return TREE_OPERAND (pointer, 0);
2107 tree ref = build1 (INDIRECT_REF, t, pointer);
2109 /* We *must* set TREE_READONLY when dereferencing a pointer to const,
2110 so that we get the proper error message if the result is used
2111 to assign to. Also, &* is supposed to be a no-op. */
2112 TREE_READONLY (ref) = CP_TYPE_CONST_P (t);
2113 TREE_THIS_VOLATILE (ref) = CP_TYPE_VOLATILE_P (t);
2114 TREE_SIDE_EFFECTS (ref)
2115 = (TREE_THIS_VOLATILE (ref) || TREE_SIDE_EFFECTS (pointer));
2119 /* `pointer' won't be an error_mark_node if we were given a
2120 pointer to member, so it's cool to check for this here. */
2121 else if (TYPE_PTR_TO_MEMBER_P (type))
2122 error ("invalid use of %qs on pointer to member", errorstring);
2123 else if (pointer != error_mark_node)
2126 error ("invalid type argument of %qs", errorstring);
2128 error ("invalid type argument");
2130 return error_mark_node;
2133 /* This handles expressions of the form "a[i]", which denotes
2136 This is logically equivalent in C to *(a+i), but we may do it differently.
2137 If A is a variable or a member, we generate a primitive ARRAY_REF.
2138 This avoids forcing the array out of registers, and can work on
2139 arrays that are not lvalues (for example, members of structures returned
2142 If INDEX is of some user-defined type, it must be converted to
2143 integer type. Otherwise, to make a compatible PLUS_EXPR, it
2144 will inherit the type of the array, which will be some pointer type. */
2147 build_array_ref (tree array, tree idx)
2151 error ("subscript missing in array reference");
2152 return error_mark_node;
2155 if (TREE_TYPE (array) == error_mark_node
2156 || TREE_TYPE (idx) == error_mark_node)
2157 return error_mark_node;
2159 /* If ARRAY is a COMPOUND_EXPR or COND_EXPR, move our reference
2161 switch (TREE_CODE (array))
2165 tree value = build_array_ref (TREE_OPERAND (array, 1), idx);
2166 return build2 (COMPOUND_EXPR, TREE_TYPE (value),
2167 TREE_OPERAND (array, 0), value);
2171 return build_conditional_expr
2172 (TREE_OPERAND (array, 0),
2173 build_array_ref (TREE_OPERAND (array, 1), idx),
2174 build_array_ref (TREE_OPERAND (array, 2), idx));
2180 if (TREE_CODE (TREE_TYPE (array)) == ARRAY_TYPE)
2184 /* Subscripting with type char is likely to lose
2185 on a machine where chars are signed.
2186 So warn on any machine, but optionally.
2187 Don't warn for unsigned char since that type is safe.
2188 Don't warn for signed char because anyone who uses that
2189 must have done so deliberately. */
2190 if (warn_char_subscripts
2191 && TYPE_MAIN_VARIANT (TREE_TYPE (idx)) == char_type_node)
2192 warning ("array subscript has type %<char%>");
2194 if (!INTEGRAL_OR_ENUMERATION_TYPE_P (TREE_TYPE (idx)))
2196 error ("array subscript is not an integer");
2197 return error_mark_node;
2200 /* Apply integral promotions *after* noticing character types.
2201 (It is unclear why we do these promotions -- the standard
2202 does not say that we should. In fact, the natual thing would
2203 seem to be to convert IDX to ptrdiff_t; we're performing
2204 pointer arithmetic.) */
2205 idx = perform_integral_promotions (idx);
2207 /* An array that is indexed by a non-constant
2208 cannot be stored in a register; we must be able to do
2209 address arithmetic on its address.
2210 Likewise an array of elements of variable size. */
2211 if (TREE_CODE (idx) != INTEGER_CST
2212 || (COMPLETE_TYPE_P (TREE_TYPE (TREE_TYPE (array)))
2213 && (TREE_CODE (TYPE_SIZE (TREE_TYPE (TREE_TYPE (array))))
2216 if (!cxx_mark_addressable (array))
2217 return error_mark_node;
2220 /* An array that is indexed by a constant value which is not within
2221 the array bounds cannot be stored in a register either; because we
2222 would get a crash in store_bit_field/extract_bit_field when trying
2223 to access a non-existent part of the register. */
2224 if (TREE_CODE (idx) == INTEGER_CST
2225 && TYPE_DOMAIN (TREE_TYPE (array))
2226 && ! int_fits_type_p (idx, TYPE_DOMAIN (TREE_TYPE (array))))
2228 if (!cxx_mark_addressable (array))
2229 return error_mark_node;
2232 if (pedantic && !lvalue_p (array))
2233 pedwarn ("ISO C++ forbids subscripting non-lvalue array");
2235 /* Note in C++ it is valid to subscript a `register' array, since
2236 it is valid to take the address of something with that
2237 storage specification. */
2241 while (TREE_CODE (foo) == COMPONENT_REF)
2242 foo = TREE_OPERAND (foo, 0);
2243 if (TREE_CODE (foo) == VAR_DECL && DECL_REGISTER (foo))
2244 warning ("subscripting array declared %<register%>");
2247 type = TREE_TYPE (TREE_TYPE (array));
2248 rval = build4 (ARRAY_REF, type, array, idx, NULL_TREE, NULL_TREE);
2249 /* Array ref is const/volatile if the array elements are
2250 or if the array is.. */
2251 TREE_READONLY (rval)
2252 |= (CP_TYPE_CONST_P (type) | TREE_READONLY (array));
2253 TREE_SIDE_EFFECTS (rval)
2254 |= (CP_TYPE_VOLATILE_P (type) | TREE_SIDE_EFFECTS (array));
2255 TREE_THIS_VOLATILE (rval)
2256 |= (CP_TYPE_VOLATILE_P (type) | TREE_THIS_VOLATILE (array));
2257 return require_complete_type (fold_if_not_in_template (rval));
2261 tree ar = default_conversion (array);
2262 tree ind = default_conversion (idx);
2264 /* Put the integer in IND to simplify error checking. */
2265 if (TREE_CODE (TREE_TYPE (ar)) == INTEGER_TYPE)
2272 if (ar == error_mark_node)
2275 if (TREE_CODE (TREE_TYPE (ar)) != POINTER_TYPE)
2277 error ("subscripted value is neither array nor pointer");
2278 return error_mark_node;
2280 if (TREE_CODE (TREE_TYPE (ind)) != INTEGER_TYPE)
2282 error ("array subscript is not an integer");
2283 return error_mark_node;
2286 return build_indirect_ref (cp_build_binary_op (PLUS_EXPR, ar, ind),
2291 /* Resolve a pointer to member function. INSTANCE is the object
2292 instance to use, if the member points to a virtual member.
2294 This used to avoid checking for virtual functions if basetype
2295 has no virtual functions, according to an earlier ANSI draft.
2296 With the final ISO C++ rules, such an optimization is
2297 incorrect: A pointer to a derived member can be static_cast
2298 to pointer-to-base-member, as long as the dynamic object
2299 later has the right member. */
2302 get_member_function_from_ptrfunc (tree *instance_ptrptr, tree function)
2304 if (TREE_CODE (function) == OFFSET_REF)
2305 function = TREE_OPERAND (function, 1);
2307 if (TYPE_PTRMEMFUNC_P (TREE_TYPE (function)))
2309 tree idx, delta, e1, e2, e3, vtbl, basetype;
2310 tree fntype = TYPE_PTRMEMFUNC_FN_TYPE (TREE_TYPE (function));
2312 tree instance_ptr = *instance_ptrptr;
2313 tree instance_save_expr = 0;
2314 if (instance_ptr == error_mark_node)
2316 if (TREE_CODE (function) == PTRMEM_CST)
2318 /* Extracting the function address from a pmf is only
2319 allowed with -Wno-pmf-conversions. It only works for
2321 e1 = build_addr_func (PTRMEM_CST_MEMBER (function));
2322 e1 = convert (fntype, e1);
2327 error ("object missing in use of %qE", function);
2328 return error_mark_node;
2332 if (TREE_SIDE_EFFECTS (instance_ptr))
2333 instance_ptr = instance_save_expr = save_expr (instance_ptr);
2335 if (TREE_SIDE_EFFECTS (function))
2336 function = save_expr (function);
2338 /* Start by extracting all the information from the PMF itself. */
2339 e3 = PFN_FROM_PTRMEMFUNC (function);
2340 delta = build_ptrmemfunc_access_expr (function, delta_identifier);
2341 idx = build1 (NOP_EXPR, vtable_index_type, e3);
2342 switch (TARGET_PTRMEMFUNC_VBIT_LOCATION)
2344 case ptrmemfunc_vbit_in_pfn:
2345 e1 = cp_build_binary_op (BIT_AND_EXPR, idx, integer_one_node);
2346 idx = cp_build_binary_op (MINUS_EXPR, idx, integer_one_node);
2349 case ptrmemfunc_vbit_in_delta:
2350 e1 = cp_build_binary_op (BIT_AND_EXPR, delta, integer_one_node);
2351 delta = cp_build_binary_op (RSHIFT_EXPR, delta, integer_one_node);
2358 /* Convert down to the right base before using the instance. First
2360 basetype = TYPE_METHOD_BASETYPE (TREE_TYPE (fntype));
2361 basetype = lookup_base (TREE_TYPE (TREE_TYPE (instance_ptr)),
2362 basetype, ba_check, NULL);
2363 instance_ptr = build_base_path (PLUS_EXPR, instance_ptr, basetype, 1);
2364 if (instance_ptr == error_mark_node)
2365 return error_mark_node;
2366 /* ...and then the delta in the PMF. */
2367 instance_ptr = build2 (PLUS_EXPR, TREE_TYPE (instance_ptr),
2368 instance_ptr, delta);
2370 /* Hand back the adjusted 'this' argument to our caller. */
2371 *instance_ptrptr = instance_ptr;
2373 /* Next extract the vtable pointer from the object. */
2374 vtbl = build1 (NOP_EXPR, build_pointer_type (vtbl_ptr_type_node),
2376 vtbl = build_indirect_ref (vtbl, NULL);
2378 /* Finally, extract the function pointer from the vtable. */
2379 e2 = fold (build2 (PLUS_EXPR, TREE_TYPE (vtbl), vtbl, idx));
2380 e2 = build_indirect_ref (e2, NULL);
2381 TREE_CONSTANT (e2) = 1;
2382 TREE_INVARIANT (e2) = 1;
2384 /* When using function descriptors, the address of the
2385 vtable entry is treated as a function pointer. */
2386 if (TARGET_VTABLE_USES_DESCRIPTORS)
2387 e2 = build1 (NOP_EXPR, TREE_TYPE (e2),
2388 build_unary_op (ADDR_EXPR, e2, /*noconvert=*/1));
2390 TREE_TYPE (e2) = TREE_TYPE (e3);
2391 e1 = build_conditional_expr (e1, e2, e3);
2393 /* Make sure this doesn't get evaluated first inside one of the
2394 branches of the COND_EXPR. */
2395 if (instance_save_expr)
2396 e1 = build2 (COMPOUND_EXPR, TREE_TYPE (e1),
2397 instance_save_expr, e1);
2405 build_function_call (tree function, tree params)
2407 tree fntype, fndecl;
2408 tree coerced_params;
2409 tree name = NULL_TREE;
2411 tree original = function;
2413 /* build_c_cast puts on a NOP_EXPR to make the result not an lvalue.
2414 Strip such NOP_EXPRs, since FUNCTION is used in non-lvalue context. */
2415 if (TREE_CODE (function) == NOP_EXPR
2416 && TREE_TYPE (function) == TREE_TYPE (TREE_OPERAND (function, 0)))
2417 function = TREE_OPERAND (function, 0);
2419 if (TREE_CODE (function) == FUNCTION_DECL)
2421 name = DECL_NAME (function);
2423 mark_used (function);
2426 /* Convert anything with function type to a pointer-to-function. */
2427 if (pedantic && DECL_MAIN_P (function))
2428 pedwarn ("ISO C++ forbids calling %<::main%> from within program");
2430 /* Differs from default_conversion by not setting TREE_ADDRESSABLE
2431 (because calling an inline function does not mean the function
2432 needs to be separately compiled). */
2434 if (DECL_INLINE (function))
2435 function = inline_conversion (function);
2437 function = build_addr_func (function);
2443 function = build_addr_func (function);
2446 if (function == error_mark_node)
2447 return error_mark_node;
2449 fntype = TREE_TYPE (function);
2451 if (TYPE_PTRMEMFUNC_P (fntype))
2453 error ("must use %<.*%> or %<->*%> to call pointer-to-member "
2454 "function in %<%E (...)%>",
2456 return error_mark_node;
2459 is_method = (TREE_CODE (fntype) == POINTER_TYPE
2460 && TREE_CODE (TREE_TYPE (fntype)) == METHOD_TYPE);
2462 if (!((TREE_CODE (fntype) == POINTER_TYPE
2463 && TREE_CODE (TREE_TYPE (fntype)) == FUNCTION_TYPE)
2465 || TREE_CODE (function) == TEMPLATE_ID_EXPR))
2467 error ("%qE cannot be used as a function", original);
2468 return error_mark_node;
2471 /* fntype now gets the type of function pointed to. */
2472 fntype = TREE_TYPE (fntype);
2474 /* Convert the parameters to the types declared in the
2475 function prototype, or apply default promotions. */
2477 coerced_params = convert_arguments (TYPE_ARG_TYPES (fntype),
2478 params, fndecl, LOOKUP_NORMAL);
2479 if (coerced_params == error_mark_node)
2480 return error_mark_node;
2482 /* Check for errors in format strings and inappropriately
2485 check_function_arguments (TYPE_ATTRIBUTES (fntype), coerced_params);
2487 return build_cxx_call (function, coerced_params);
2490 /* Convert the actual parameter expressions in the list VALUES
2491 to the types in the list TYPELIST.
2492 If parmdecls is exhausted, or when an element has NULL as its type,
2493 perform the default conversions.
2495 NAME is an IDENTIFIER_NODE or 0. It is used only for error messages.
2497 This is also where warnings about wrong number of args are generated.
2499 Return a list of expressions for the parameters as converted.
2501 Both VALUES and the returned value are chains of TREE_LIST nodes
2502 with the elements of the list in the TREE_VALUE slots of those nodes.
2504 In C++, unspecified trailing parameters can be filled in with their
2505 default arguments, if such were specified. Do so here. */
2508 convert_arguments (tree typelist, tree values, tree fndecl, int flags)
2510 tree typetail, valtail;
2511 tree result = NULL_TREE;
2512 const char *called_thing = 0;
2515 /* Argument passing is always copy-initialization. */
2516 flags |= LOOKUP_ONLYCONVERTING;
2520 if (TREE_CODE (TREE_TYPE (fndecl)) == METHOD_TYPE)
2522 if (DECL_NAME (fndecl) == NULL_TREE
2523 || IDENTIFIER_HAS_TYPE_VALUE (DECL_NAME (fndecl)))
2524 called_thing = "constructor";
2526 called_thing = "member function";
2529 called_thing = "function";
2532 for (valtail = values, typetail = typelist;
2534 valtail = TREE_CHAIN (valtail), i++)
2536 tree type = typetail ? TREE_VALUE (typetail) : 0;
2537 tree val = TREE_VALUE (valtail);
2539 if (val == error_mark_node)
2540 return error_mark_node;
2542 if (type == void_type_node)
2546 cp_error_at ("too many arguments to %s %q+#D", called_thing,
2548 error ("at this point in file");
2551 error ("too many arguments to function");
2552 /* In case anybody wants to know if this argument
2555 TREE_TYPE (tree_last (result)) = error_mark_node;
2559 /* build_c_cast puts on a NOP_EXPR to make the result not an lvalue.
2560 Strip such NOP_EXPRs, since VAL is used in non-lvalue context. */
2561 if (TREE_CODE (val) == NOP_EXPR
2562 && TREE_TYPE (val) == TREE_TYPE (TREE_OPERAND (val, 0))
2563 && (type == 0 || TREE_CODE (type) != REFERENCE_TYPE))
2564 val = TREE_OPERAND (val, 0);
2566 if (type == 0 || TREE_CODE (type) != REFERENCE_TYPE)
2568 if (TREE_CODE (TREE_TYPE (val)) == ARRAY_TYPE
2569 || TREE_CODE (TREE_TYPE (val)) == FUNCTION_TYPE
2570 || TREE_CODE (TREE_TYPE (val)) == METHOD_TYPE)
2571 val = decay_conversion (val);
2574 if (val == error_mark_node)
2575 return error_mark_node;
2579 /* Formal parm type is specified by a function prototype. */
2582 if (!COMPLETE_TYPE_P (complete_type (type)))
2585 error ("parameter %P of %qD has incomplete type %qT",
2588 error ("parameter %P has incomplete type %qT", i, type);
2589 parmval = error_mark_node;
2593 parmval = convert_for_initialization
2594 (NULL_TREE, type, val, flags,
2595 "argument passing", fndecl, i);
2596 parmval = convert_for_arg_passing (type, parmval);
2599 if (parmval == error_mark_node)
2600 return error_mark_node;
2602 result = tree_cons (NULL_TREE, parmval, result);
2606 if (fndecl && DECL_BUILT_IN (fndecl)
2607 && DECL_FUNCTION_CODE (fndecl) == BUILT_IN_CONSTANT_P)
2608 /* Don't do ellipsis conversion for __built_in_constant_p
2609 as this will result in spurious warnings for non-POD
2611 val = require_complete_type (val);
2613 val = convert_arg_to_ellipsis (val);
2615 result = tree_cons (NULL_TREE, val, result);
2619 typetail = TREE_CHAIN (typetail);
2622 if (typetail != 0 && typetail != void_list_node)
2624 /* See if there are default arguments that can be used. */
2625 if (TREE_PURPOSE (typetail)
2626 && TREE_CODE (TREE_PURPOSE (typetail)) != DEFAULT_ARG)
2628 for (; typetail != void_list_node; ++i)
2631 = convert_default_arg (TREE_VALUE (typetail),
2632 TREE_PURPOSE (typetail),
2635 if (parmval == error_mark_node)
2636 return error_mark_node;
2638 result = tree_cons (0, parmval, result);
2639 typetail = TREE_CHAIN (typetail);
2640 /* ends with `...'. */
2641 if (typetail == NULL_TREE)
2649 cp_error_at ("too few arguments to %s %q+#D",
2650 called_thing, fndecl);
2651 error ("at this point in file");
2654 error ("too few arguments to function");
2655 return error_mark_list;
2659 return nreverse (result);
2662 /* Build a binary-operation expression, after performing default
2663 conversions on the operands. CODE is the kind of expression to build. */
2666 build_x_binary_op (enum tree_code code, tree arg1, tree arg2,
2676 if (processing_template_decl)
2678 if (type_dependent_expression_p (arg1)
2679 || type_dependent_expression_p (arg2))
2680 return build_min_nt (code, arg1, arg2);
2681 arg1 = build_non_dependent_expr (arg1);
2682 arg2 = build_non_dependent_expr (arg2);
2685 if (code == DOTSTAR_EXPR)
2686 expr = build_m_component_ref (arg1, arg2);
2688 expr = build_new_op (code, LOOKUP_NORMAL, arg1, arg2, NULL_TREE,
2691 if (processing_template_decl && expr != error_mark_node)
2692 return build_min_non_dep (code, expr, orig_arg1, orig_arg2);
2697 /* Build a binary-operation expression without default conversions.
2698 CODE is the kind of expression to build.
2699 This function differs from `build' in several ways:
2700 the data type of the result is computed and recorded in it,
2701 warnings are generated if arg data types are invalid,
2702 special handling for addition and subtraction of pointers is known,
2703 and some optimization is done (operations on narrow ints
2704 are done in the narrower type when that gives the same result).
2705 Constant folding is also done before the result is returned.
2707 Note that the operands will never have enumeral types
2708 because either they have just had the default conversions performed
2709 or they have both just been converted to some other type in which
2710 the arithmetic is to be done.
2712 C++: must do special pointer arithmetic when implementing
2713 multiple inheritance, and deal with pointer to member functions. */
2716 build_binary_op (enum tree_code code, tree orig_op0, tree orig_op1,
2717 int convert_p ATTRIBUTE_UNUSED)
2720 enum tree_code code0, code1;
2723 /* Expression code to give to the expression when it is built.
2724 Normally this is CODE, which is what the caller asked for,
2725 but in some special cases we change it. */
2726 enum tree_code resultcode = code;
2728 /* Data type in which the computation is to be performed.
2729 In the simplest cases this is the common type of the arguments. */
2730 tree result_type = NULL;
2732 /* Nonzero means operands have already been type-converted
2733 in whatever way is necessary.
2734 Zero means they need to be converted to RESULT_TYPE. */
2737 /* Nonzero means create the expression with this type, rather than
2739 tree build_type = 0;
2741 /* Nonzero means after finally constructing the expression
2742 convert it to this type. */
2743 tree final_type = 0;
2747 /* Nonzero if this is an operation like MIN or MAX which can
2748 safely be computed in short if both args are promoted shorts.
2749 Also implies COMMON.
2750 -1 indicates a bitwise operation; this makes a difference
2751 in the exact conditions for when it is safe to do the operation
2752 in a narrower mode. */
2755 /* Nonzero if this is a comparison operation;
2756 if both args are promoted shorts, compare the original shorts.
2757 Also implies COMMON. */
2758 int short_compare = 0;
2760 /* Nonzero if this is a right-shift operation, which can be computed on the
2761 original short and then promoted if the operand is a promoted short. */
2762 int short_shift = 0;
2764 /* Nonzero means set RESULT_TYPE to the common type of the args. */
2767 /* True if both operands have arithmetic type. */
2768 bool arithmetic_types_p;
2770 /* Apply default conversions. */
2774 if (code == TRUTH_AND_EXPR || code == TRUTH_ANDIF_EXPR
2775 || code == TRUTH_OR_EXPR || code == TRUTH_ORIF_EXPR
2776 || code == TRUTH_XOR_EXPR)
2778 if (!really_overloaded_fn (op0))
2779 op0 = decay_conversion (op0);
2780 if (!really_overloaded_fn (op1))
2781 op1 = decay_conversion (op1);
2785 if (!really_overloaded_fn (op0))
2786 op0 = default_conversion (op0);
2787 if (!really_overloaded_fn (op1))
2788 op1 = default_conversion (op1);
2791 /* Strip NON_LVALUE_EXPRs, etc., since we aren't using as an lvalue. */
2792 STRIP_TYPE_NOPS (op0);
2793 STRIP_TYPE_NOPS (op1);
2795 /* DTRT if one side is an overloaded function, but complain about it. */
2796 if (type_unknown_p (op0))
2798 tree t = instantiate_type (TREE_TYPE (op1), op0, tf_none);
2799 if (t != error_mark_node)
2801 pedwarn ("assuming cast to type %qT from overloaded function",
2806 if (type_unknown_p (op1))
2808 tree t = instantiate_type (TREE_TYPE (op0), op1, tf_none);
2809 if (t != error_mark_node)
2811 pedwarn ("assuming cast to type %qT from overloaded function",
2817 type0 = TREE_TYPE (op0);
2818 type1 = TREE_TYPE (op1);
2820 /* The expression codes of the data types of the arguments tell us
2821 whether the arguments are integers, floating, pointers, etc. */
2822 code0 = TREE_CODE (type0);
2823 code1 = TREE_CODE (type1);
2825 /* If an error was already reported for one of the arguments,
2826 avoid reporting another error. */
2828 if (code0 == ERROR_MARK || code1 == ERROR_MARK)
2829 return error_mark_node;
2834 /* Handle the pointer + int case. */
2835 if (code0 == POINTER_TYPE && code1 == INTEGER_TYPE)
2836 return cp_pointer_int_sum (PLUS_EXPR, op0, op1);
2837 else if (code1 == POINTER_TYPE && code0 == INTEGER_TYPE)
2838 return cp_pointer_int_sum (PLUS_EXPR, op1, op0);
2844 /* Subtraction of two similar pointers.
2845 We must subtract them as integers, then divide by object size. */
2846 if (code0 == POINTER_TYPE && code1 == POINTER_TYPE
2847 && same_type_ignoring_top_level_qualifiers_p (TREE_TYPE (type0),
2849 return pointer_diff (op0, op1, common_type (type0, type1));
2850 /* Handle pointer minus int. Just like pointer plus int. */
2851 else if (code0 == POINTER_TYPE && code1 == INTEGER_TYPE)
2852 return cp_pointer_int_sum (MINUS_EXPR, op0, op1);
2861 case TRUNC_DIV_EXPR:
2863 case FLOOR_DIV_EXPR:
2864 case ROUND_DIV_EXPR:
2865 case EXACT_DIV_EXPR:
2866 if ((code0 == INTEGER_TYPE || code0 == REAL_TYPE
2867 || code0 == COMPLEX_TYPE || code0 == VECTOR_TYPE)
2868 && (code1 == INTEGER_TYPE || code1 == REAL_TYPE
2869 || code1 == COMPLEX_TYPE || code1 == VECTOR_TYPE))
2871 if (TREE_CODE (op1) == INTEGER_CST && integer_zerop (op1))
2872 warning ("division by zero in %<%E / 0%>", op0);
2873 else if (TREE_CODE (op1) == REAL_CST && real_zerop (op1))
2874 warning ("division by zero in %<%E / 0.%>", op0);
2876 if (code0 == COMPLEX_TYPE || code0 == VECTOR_TYPE)
2877 code0 = TREE_CODE (TREE_TYPE (TREE_TYPE (op0)));
2878 if (code1 == COMPLEX_TYPE || code1 == VECTOR_TYPE)
2879 code1 = TREE_CODE (TREE_TYPE (TREE_TYPE (op1)));
2881 if (!(code0 == INTEGER_TYPE && code1 == INTEGER_TYPE))
2882 resultcode = RDIV_EXPR;
2884 /* When dividing two signed integers, we have to promote to int.
2885 unless we divide by a constant != -1. Note that default
2886 conversion will have been performed on the operands at this
2887 point, so we have to dig out the original type to find out if
2889 shorten = ((TREE_CODE (op0) == NOP_EXPR
2890 && TYPE_UNSIGNED (TREE_TYPE (TREE_OPERAND (op0, 0))))
2891 || (TREE_CODE (op1) == INTEGER_CST
2892 && ! integer_all_onesp (op1)));
2901 if (code0 == INTEGER_TYPE && code1 == INTEGER_TYPE)
2905 case TRUNC_MOD_EXPR:
2906 case FLOOR_MOD_EXPR:
2907 if (code1 == INTEGER_TYPE && integer_zerop (op1))
2908 warning ("division by zero in %<%E %% 0%>", op0);
2909 else if (code1 == REAL_TYPE && real_zerop (op1))
2910 warning ("division by zero in %<%E %% 0.%>", op0);
2912 if (code0 == INTEGER_TYPE && code1 == INTEGER_TYPE)
2914 /* Although it would be tempting to shorten always here, that loses
2915 on some targets, since the modulo instruction is undefined if the
2916 quotient can't be represented in the computation mode. We shorten
2917 only if unsigned or if dividing by something we know != -1. */
2918 shorten = ((TREE_CODE (op0) == NOP_EXPR
2919 && TYPE_UNSIGNED (TREE_TYPE (TREE_OPERAND (op0, 0))))
2920 || (TREE_CODE (op1) == INTEGER_CST
2921 && ! integer_all_onesp (op1)));
2926 case TRUTH_ANDIF_EXPR:
2927 case TRUTH_ORIF_EXPR:
2928 case TRUTH_AND_EXPR:
2930 result_type = boolean_type_node;
2933 /* Shift operations: result has same type as first operand;
2934 always convert second operand to int.
2935 Also set SHORT_SHIFT if shifting rightward. */
2938 if (code0 == INTEGER_TYPE && code1 == INTEGER_TYPE)
2940 result_type = type0;
2941 if (TREE_CODE (op1) == INTEGER_CST)
2943 if (tree_int_cst_lt (op1, integer_zero_node))
2944 warning ("right shift count is negative");
2947 if (! integer_zerop (op1))
2949 if (compare_tree_int (op1, TYPE_PRECISION (type0)) >= 0)
2950 warning ("right shift count >= width of type");
2953 /* Convert the shift-count to an integer, regardless of
2954 size of value being shifted. */
2955 if (TYPE_MAIN_VARIANT (TREE_TYPE (op1)) != integer_type_node)
2956 op1 = cp_convert (integer_type_node, op1);
2957 /* Avoid converting op1 to result_type later. */
2963 if (code0 == INTEGER_TYPE && code1 == INTEGER_TYPE)
2965 result_type = type0;
2966 if (TREE_CODE (op1) == INTEGER_CST)
2968 if (tree_int_cst_lt (op1, integer_zero_node))
2969 warning ("left shift count is negative");
2970 else if (compare_tree_int (op1, TYPE_PRECISION (type0)) >= 0)
2971 warning ("left shift count >= width of type");
2973 /* Convert the shift-count to an integer, regardless of
2974 size of value being shifted. */
2975 if (TYPE_MAIN_VARIANT (TREE_TYPE (op1)) != integer_type_node)
2976 op1 = cp_convert (integer_type_node, op1);
2977 /* Avoid converting op1 to result_type later. */
2984 if (code0 == INTEGER_TYPE && code1 == INTEGER_TYPE)
2986 result_type = type0;
2987 if (TREE_CODE (op1) == INTEGER_CST)
2989 if (tree_int_cst_lt (op1, integer_zero_node))
2990 warning ("%s rotate count is negative",
2991 (code == LROTATE_EXPR) ? "left" : "right");
2992 else if (compare_tree_int (op1, TYPE_PRECISION (type0)) >= 0)
2993 warning ("%s rotate count >= width of type",
2994 (code == LROTATE_EXPR) ? "left" : "right");
2996 /* Convert the shift-count to an integer, regardless of
2997 size of value being shifted. */
2998 if (TYPE_MAIN_VARIANT (TREE_TYPE (op1)) != integer_type_node)
2999 op1 = cp_convert (integer_type_node, op1);
3005 if (warn_float_equal && (code0 == REAL_TYPE || code1 == REAL_TYPE))
3006 warning ("comparing floating point with == or != is unsafe");
3008 build_type = boolean_type_node;
3009 if ((code0 == INTEGER_TYPE || code0 == REAL_TYPE
3010 || code0 == COMPLEX_TYPE)
3011 && (code1 == INTEGER_TYPE || code1 == REAL_TYPE
3012 || code1 == COMPLEX_TYPE))
3014 else if ((code0 == POINTER_TYPE && code1 == POINTER_TYPE)
3015 || (TYPE_PTRMEM_P (type0) && TYPE_PTRMEM_P (type1)))
3016 result_type = composite_pointer_type (type0, type1, op0, op1,
3018 else if ((code0 == POINTER_TYPE || TYPE_PTRMEM_P (type0))
3019 && null_ptr_cst_p (op1))
3020 result_type = type0;
3021 else if ((code1 == POINTER_TYPE || TYPE_PTRMEM_P (type1))
3022 && null_ptr_cst_p (op0))
3023 result_type = type1;
3024 else if (code0 == POINTER_TYPE && code1 == INTEGER_TYPE)
3026 result_type = type0;
3027 error ("ISO C++ forbids comparison between pointer and integer");
3029 else if (code0 == INTEGER_TYPE && code1 == POINTER_TYPE)
3031 result_type = type1;
3032 error ("ISO C++ forbids comparison between pointer and integer");
3034 else if (TYPE_PTRMEMFUNC_P (type0) && null_ptr_cst_p (op1))
3036 op0 = build_ptrmemfunc_access_expr (op0, pfn_identifier);
3037 op1 = cp_convert (TREE_TYPE (op0), integer_zero_node);
3038 result_type = TREE_TYPE (op0);
3040 else if (TYPE_PTRMEMFUNC_P (type1) && null_ptr_cst_p (op0))
3041 return cp_build_binary_op (code, op1, op0);
3042 else if (TYPE_PTRMEMFUNC_P (type0) && TYPE_PTRMEMFUNC_P (type1)
3043 && same_type_p (type0, type1))
3045 /* E will be the final comparison. */
3047 /* E1 and E2 are for scratch. */
3055 if (TREE_SIDE_EFFECTS (op0))
3056 op0 = save_expr (op0);
3057 if (TREE_SIDE_EFFECTS (op1))
3058 op1 = save_expr (op1);
3063 && (!op0.pfn || op0.delta == op1.delta))
3065 The reason for the `!op0.pfn' bit is that a NULL
3066 pointer-to-member is any member with a zero PFN; the
3067 DELTA field is unspecified. */
3068 pfn0 = pfn_from_ptrmemfunc (op0);
3069 pfn1 = pfn_from_ptrmemfunc (op1);
3070 delta0 = build_ptrmemfunc_access_expr (op0,
3072 delta1 = build_ptrmemfunc_access_expr (op1,
3074 e1 = cp_build_binary_op (EQ_EXPR, delta0, delta1);
3075 e2 = cp_build_binary_op (EQ_EXPR,
3077 cp_convert (TREE_TYPE (pfn0),
3078 integer_zero_node));
3079 e1 = cp_build_binary_op (TRUTH_ORIF_EXPR, e1, e2);
3080 e2 = build2 (EQ_EXPR, boolean_type_node, pfn0, pfn1);
3081 e = cp_build_binary_op (TRUTH_ANDIF_EXPR, e2, e1);
3082 if (code == EQ_EXPR)
3084 return cp_build_binary_op (EQ_EXPR, e, integer_zero_node);
3088 gcc_assert (!TYPE_PTRMEMFUNC_P (type0)
3089 || !same_type_p (TYPE_PTRMEMFUNC_FN_TYPE (type0),
3091 gcc_assert (!TYPE_PTRMEMFUNC_P (type1)
3092 || !same_type_p (TYPE_PTRMEMFUNC_FN_TYPE (type1),
3100 if ((code0 == INTEGER_TYPE || code0 == REAL_TYPE)
3101 && (code1 == INTEGER_TYPE || code1 == REAL_TYPE))
3103 else if (code0 == POINTER_TYPE && code1 == POINTER_TYPE)
3104 result_type = composite_pointer_type (type0, type1, op0, op1,
3112 build_type = boolean_type_node;
3113 if ((code0 == INTEGER_TYPE || code0 == REAL_TYPE)
3114 && (code1 == INTEGER_TYPE || code1 == REAL_TYPE))
3116 else if (code0 == POINTER_TYPE && code1 == POINTER_TYPE)
3117 result_type = composite_pointer_type (type0, type1, op0, op1,
3119 else if (code0 == POINTER_TYPE && TREE_CODE (op1) == INTEGER_CST
3120 && integer_zerop (op1))
3121 result_type = type0;
3122 else if (code1 == POINTER_TYPE && TREE_CODE (op0) == INTEGER_CST
3123 && integer_zerop (op0))
3124 result_type = type1;
3125 else if (code0 == POINTER_TYPE && code1 == INTEGER_TYPE)
3127 result_type = type0;
3128 pedwarn ("ISO C++ forbids comparison between pointer and integer");
3130 else if (code0 == INTEGER_TYPE && code1 == POINTER_TYPE)
3132 result_type = type1;
3133 pedwarn ("ISO C++ forbids comparison between pointer and integer");
3137 case UNORDERED_EXPR:
3144 build_type = integer_type_node;
3145 if (code0 != REAL_TYPE || code1 != REAL_TYPE)
3147 error ("unordered comparison on non-floating point argument");
3148 return error_mark_node;
3157 arithmetic_types_p =
3158 ((code0 == INTEGER_TYPE || code0 == REAL_TYPE || code0 == COMPLEX_TYPE)
3159 && (code1 == INTEGER_TYPE || code1 == REAL_TYPE
3160 || code1 == COMPLEX_TYPE));
3161 /* Determine the RESULT_TYPE, if it is not already known. */
3163 && arithmetic_types_p
3164 && (shorten || common || short_compare))
3165 result_type = common_type (type0, type1);
3169 error ("invalid operands of types %qT and %qT to binary %qO",
3170 TREE_TYPE (orig_op0), TREE_TYPE (orig_op1), code);
3171 return error_mark_node;
3174 /* If we're in a template, the only thing we need to know is the
3176 if (processing_template_decl)
3177 return build2 (resultcode,
3178 build_type ? build_type : result_type,
3181 if (arithmetic_types_p)
3183 int none_complex = (code0 != COMPLEX_TYPE && code1 != COMPLEX_TYPE);
3185 /* For certain operations (which identify themselves by shorten != 0)
3186 if both args were extended from the same smaller type,
3187 do the arithmetic in that type and then extend.
3189 shorten !=0 and !=1 indicates a bitwise operation.
3190 For them, this optimization is safe only if
3191 both args are zero-extended or both are sign-extended.
3192 Otherwise, we might change the result.
3193 Eg, (short)-1 | (unsigned short)-1 is (int)-1
3194 but calculated in (unsigned short) it would be (unsigned short)-1. */
3196 if (shorten && none_complex)
3198 int unsigned0, unsigned1;
3199 tree arg0 = get_narrower (op0, &unsigned0);
3200 tree arg1 = get_narrower (op1, &unsigned1);
3201 /* UNS is 1 if the operation to be done is an unsigned one. */
3202 int uns = TYPE_UNSIGNED (result_type);
3205 final_type = result_type;
3207 /* Handle the case that OP0 does not *contain* a conversion
3208 but it *requires* conversion to FINAL_TYPE. */
3210 if (op0 == arg0 && TREE_TYPE (op0) != final_type)
3211 unsigned0 = TYPE_UNSIGNED (TREE_TYPE (op0));
3212 if (op1 == arg1 && TREE_TYPE (op1) != final_type)
3213 unsigned1 = TYPE_UNSIGNED (TREE_TYPE (op1));
3215 /* Now UNSIGNED0 is 1 if ARG0 zero-extends to FINAL_TYPE. */
3217 /* For bitwise operations, signedness of nominal type
3218 does not matter. Consider only how operands were extended. */
3222 /* Note that in all three cases below we refrain from optimizing
3223 an unsigned operation on sign-extended args.
3224 That would not be valid. */
3226 /* Both args variable: if both extended in same way
3227 from same width, do it in that width.
3228 Do it unsigned if args were zero-extended. */
3229 if ((TYPE_PRECISION (TREE_TYPE (arg0))
3230 < TYPE_PRECISION (result_type))
3231 && (TYPE_PRECISION (TREE_TYPE (arg1))
3232 == TYPE_PRECISION (TREE_TYPE (arg0)))
3233 && unsigned0 == unsigned1
3234 && (unsigned0 || !uns))
3235 result_type = c_common_signed_or_unsigned_type
3236 (unsigned0, common_type (TREE_TYPE (arg0), TREE_TYPE (arg1)));
3237 else if (TREE_CODE (arg0) == INTEGER_CST
3238 && (unsigned1 || !uns)
3239 && (TYPE_PRECISION (TREE_TYPE (arg1))
3240 < TYPE_PRECISION (result_type))
3241 && (type = c_common_signed_or_unsigned_type
3242 (unsigned1, TREE_TYPE (arg1)),
3243 int_fits_type_p (arg0, type)))
3245 else if (TREE_CODE (arg1) == INTEGER_CST
3246 && (unsigned0 || !uns)
3247 && (TYPE_PRECISION (TREE_TYPE (arg0))
3248 < TYPE_PRECISION (result_type))
3249 && (type = c_common_signed_or_unsigned_type
3250 (unsigned0, TREE_TYPE (arg0)),
3251 int_fits_type_p (arg1, type)))
3255 /* Shifts can be shortened if shifting right. */
3260 tree arg0 = get_narrower (op0, &unsigned_arg);
3262 final_type = result_type;
3264 if (arg0 == op0 && final_type == TREE_TYPE (op0))
3265 unsigned_arg = TYPE_UNSIGNED (TREE_TYPE (op0));
3267 if (TYPE_PRECISION (TREE_TYPE (arg0)) < TYPE_PRECISION (result_type)
3268 /* We can shorten only if the shift count is less than the
3269 number of bits in the smaller type size. */
3270 && compare_tree_int (op1, TYPE_PRECISION (TREE_TYPE (arg0))) < 0
3271 /* If arg is sign-extended and then unsigned-shifted,
3272 we can simulate this with a signed shift in arg's type
3273 only if the extended result is at least twice as wide
3274 as the arg. Otherwise, the shift could use up all the
3275 ones made by sign-extension and bring in zeros.
3276 We can't optimize that case at all, but in most machines
3277 it never happens because available widths are 2**N. */
3278 && (!TYPE_UNSIGNED (final_type)
3280 || (((unsigned) 2 * TYPE_PRECISION (TREE_TYPE (arg0)))
3281 <= TYPE_PRECISION (result_type))))
3283 /* Do an unsigned shift if the operand was zero-extended. */
3285 = c_common_signed_or_unsigned_type (unsigned_arg,
3287 /* Convert value-to-be-shifted to that type. */
3288 if (TREE_TYPE (op0) != result_type)
3289 op0 = cp_convert (result_type, op0);
3294 /* Comparison operations are shortened too but differently.
3295 They identify themselves by setting short_compare = 1. */
3299 /* Don't write &op0, etc., because that would prevent op0
3300 from being kept in a register.
3301 Instead, make copies of the our local variables and
3302 pass the copies by reference, then copy them back afterward. */
3303 tree xop0 = op0, xop1 = op1, xresult_type = result_type;
3304 enum tree_code xresultcode = resultcode;
3306 = shorten_compare (&xop0, &xop1, &xresult_type, &xresultcode);
3308 return cp_convert (boolean_type_node, val);
3309 op0 = xop0, op1 = xop1;
3311 resultcode = xresultcode;
3314 if ((short_compare || code == MIN_EXPR || code == MAX_EXPR)
3315 && warn_sign_compare
3316 /* Do not warn until the template is instantiated; we cannot
3317 bound the ranges of the arguments until that point. */
3318 && !processing_template_decl)
3320 int op0_signed = !TYPE_UNSIGNED (TREE_TYPE (orig_op0));
3321 int op1_signed = !TYPE_UNSIGNED (TREE_TYPE (orig_op1));
3323 int unsignedp0, unsignedp1;
3324 tree primop0 = get_narrower (op0, &unsignedp0);
3325 tree primop1 = get_narrower (op1, &unsignedp1);
3327 /* Check for comparison of different enum types. */
3328 if (TREE_CODE (TREE_TYPE (orig_op0)) == ENUMERAL_TYPE
3329 && TREE_CODE (TREE_TYPE (orig_op1)) == ENUMERAL_TYPE
3330 && TYPE_MAIN_VARIANT (TREE_TYPE (orig_op0))
3331 != TYPE_MAIN_VARIANT (TREE_TYPE (orig_op1)))
3333 warning ("comparison between types %q#T and %q#T",
3334 TREE_TYPE (orig_op0), TREE_TYPE (orig_op1));
3337 /* Give warnings for comparisons between signed and unsigned
3338 quantities that may fail. */
3339 /* Do the checking based on the original operand trees, so that
3340 casts will be considered, but default promotions won't be. */
3342 /* Do not warn if the comparison is being done in a signed type,
3343 since the signed type will only be chosen if it can represent
3344 all the values of the unsigned type. */
3345 if (!TYPE_UNSIGNED (result_type))
3347 /* Do not warn if both operands are unsigned. */
3348 else if (op0_signed == op1_signed)
3350 /* Do not warn if the signed quantity is an unsuffixed
3351 integer literal (or some static constant expression
3352 involving such literals or a conditional expression
3353 involving such literals) and it is non-negative. */
3354 else if ((op0_signed && tree_expr_nonnegative_p (orig_op0))
3355 || (op1_signed && tree_expr_nonnegative_p (orig_op1)))
3357 /* Do not warn if the comparison is an equality operation,
3358 the unsigned quantity is an integral constant and it does
3359 not use the most significant bit of result_type. */
3360 else if ((resultcode == EQ_EXPR || resultcode == NE_EXPR)
3361 && ((op0_signed && TREE_CODE (orig_op1) == INTEGER_CST
3362 && int_fits_type_p (orig_op1, c_common_signed_type
3364 || (op1_signed && TREE_CODE (orig_op0) == INTEGER_CST
3365 && int_fits_type_p (orig_op0, c_common_signed_type
3369 warning ("comparison between signed and unsigned integer expressions");
3371 /* Warn if two unsigned values are being compared in a size
3372 larger than their original size, and one (and only one) is the
3373 result of a `~' operator. This comparison will always fail.
3375 Also warn if one operand is a constant, and the constant does not
3376 have all bits set that are set in the ~ operand when it is
3379 if ((TREE_CODE (primop0) == BIT_NOT_EXPR)
3380 ^ (TREE_CODE (primop1) == BIT_NOT_EXPR))
3382 if (TREE_CODE (primop0) == BIT_NOT_EXPR)
3383 primop0 = get_narrower (TREE_OPERAND (op0, 0), &unsignedp0);
3384 if (TREE_CODE (primop1) == BIT_NOT_EXPR)
3385 primop1 = get_narrower (TREE_OPERAND (op1, 0), &unsignedp1);
3387 if (host_integerp (primop0, 0) || host_integerp (primop1, 0))
3390 HOST_WIDE_INT constant, mask;
3394 if (host_integerp (primop0, 0))
3397 unsignedp = unsignedp1;
3398 constant = tree_low_cst (primop0, 0);
3403 unsignedp = unsignedp0;
3404 constant = tree_low_cst (primop1, 0);
3407 bits = TYPE_PRECISION (TREE_TYPE (primop));
3408 if (bits < TYPE_PRECISION (result_type)
3409 && bits < HOST_BITS_PER_LONG && unsignedp)
3411 mask = (~ (HOST_WIDE_INT) 0) << bits;
3412 if ((mask & constant) != mask)
3413 warning ("comparison of promoted ~unsigned with constant");
3416 else if (unsignedp0 && unsignedp1
3417 && (TYPE_PRECISION (TREE_TYPE (primop0))
3418 < TYPE_PRECISION (result_type))
3419 && (TYPE_PRECISION (TREE_TYPE (primop1))
3420 < TYPE_PRECISION (result_type)))
3421 warning ("comparison of promoted ~unsigned with unsigned");
3426 /* If CONVERTED is zero, both args will be converted to type RESULT_TYPE.
3427 Then the expression will be built.
3428 It will be given type FINAL_TYPE if that is nonzero;
3429 otherwise, it will be given type RESULT_TYPE. */
3431 /* Issue warnings about peculiar, but valid, uses of NULL. */
3432 if (/* It's reasonable to use pointer values as operands of &&
3433 and ||, so NULL is no exception. */
3434 !(code == TRUTH_ANDIF_EXPR || code == TRUTH_ORIF_EXPR)
3435 && (/* If OP0 is NULL and OP1 is not a pointer, or vice versa. */
3436 (orig_op0 == null_node
3437 && TREE_CODE (TREE_TYPE (op1)) != POINTER_TYPE)
3438 /* Or vice versa. */
3439 || (orig_op1 == null_node
3440 && TREE_CODE (TREE_TYPE (op0)) != POINTER_TYPE)
3441 /* Or, both are NULL and the operation was not a comparison. */
3442 || (orig_op0 == null_node && orig_op1 == null_node
3443 && code != EQ_EXPR && code != NE_EXPR)))
3444 /* Some sort of arithmetic operation involving NULL was
3445 performed. Note that pointer-difference and pointer-addition
3446 have already been handled above, and so we don't end up here in
3448 warning ("NULL used in arithmetic");
3452 if (TREE_TYPE (op0) != result_type)
3453 op0 = cp_convert (result_type, op0);
3454 if (TREE_TYPE (op1) != result_type)
3455 op1 = cp_convert (result_type, op1);
3457 if (op0 == error_mark_node || op1 == error_mark_node)
3458 return error_mark_node;
3461 if (build_type == NULL_TREE)
3462 build_type = result_type;
3464 result = build2 (resultcode, build_type, op0, op1);
3465 result = fold_if_not_in_template (result);
3466 if (final_type != 0)
3467 result = cp_convert (final_type, result);
3471 /* Return a tree for the sum or difference (RESULTCODE says which)
3472 of pointer PTROP and integer INTOP. */
3475 cp_pointer_int_sum (enum tree_code resultcode, tree ptrop, tree intop)
3477 tree res_type = TREE_TYPE (ptrop);
3479 /* pointer_int_sum() uses size_in_bytes() on the TREE_TYPE(res_type)
3480 in certain circumstance (when it's valid to do so). So we need
3481 to make sure it's complete. We don't need to check here, if we
3482 can actually complete it at all, as those checks will be done in
3483 pointer_int_sum() anyway. */
3484 complete_type (TREE_TYPE (res_type));
3486 return pointer_int_sum (resultcode, ptrop,
3487 fold_if_not_in_template (intop));
3490 /* Return a tree for the difference of pointers OP0 and OP1.
3491 The resulting tree has type int. */
3494 pointer_diff (tree op0, tree op1, tree ptrtype)
3497 tree restype = ptrdiff_type_node;
3498 tree target_type = TREE_TYPE (ptrtype);
3500 if (!complete_type_or_else (target_type, NULL_TREE))
3501 return error_mark_node;
3503 if (pedantic || warn_pointer_arith)
3505 if (TREE_CODE (target_type) == VOID_TYPE)
3506 pedwarn ("ISO C++ forbids using pointer of type %<void *%> in subtraction");
3507 if (TREE_CODE (target_type) == FUNCTION_TYPE)
3508 pedwarn ("ISO C++ forbids using pointer to a function in subtraction");
3509 if (TREE_CODE (target_type) == METHOD_TYPE)
3510 pedwarn ("ISO C++ forbids using pointer to a method in subtraction");
3513 /* First do the subtraction as integers;
3514 then drop through to build the divide operator. */
3516 op0 = cp_build_binary_op (MINUS_EXPR,
3517 cp_convert (restype, op0),
3518 cp_convert (restype, op1));
3520 /* This generates an error if op1 is a pointer to an incomplete type. */
3521 if (!COMPLETE_TYPE_P (TREE_TYPE (TREE_TYPE (op1))))
3522 error ("invalid use of a pointer to an incomplete type in pointer arithmetic");
3524 op1 = (TYPE_PTROB_P (ptrtype)
3525 ? size_in_bytes (target_type)
3526 : integer_one_node);
3528 /* Do the division. */
3530 result = build2 (EXACT_DIV_EXPR, restype, op0, cp_convert (restype, op1));
3531 return fold_if_not_in_template (result);
3534 /* Construct and perhaps optimize a tree representation
3535 for a unary operation. CODE, a tree_code, specifies the operation
3536 and XARG is the operand. */
3539 build_x_unary_op (enum tree_code code, tree xarg)
3541 tree orig_expr = xarg;
3545 if (processing_template_decl)
3547 if (type_dependent_expression_p (xarg))
3548 return build_min_nt (code, xarg, NULL_TREE);
3550 /* For non-dependent pointer-to-member, the SCOPE_REF will be
3551 processed during template substitution. Just compute the
3552 right type here and build an ADDR_EXPR around it for
3554 if (code == ADDR_EXPR && TREE_CODE (xarg) == SCOPE_REF)
3557 if (TREE_TYPE (xarg) == unknown_type_node)
3558 type = unknown_type_node;
3559 else if (TREE_CODE (TREE_TYPE (xarg)) == FUNCTION_TYPE)
3560 type = build_pointer_type (TREE_TYPE (xarg));
3562 type = build_ptrmem_type (TREE_OPERAND (xarg, 0),
3564 return build_min (code, type, xarg, NULL_TREE);
3567 xarg = build_non_dependent_expr (xarg);
3572 /* [expr.unary.op] says:
3574 The address of an object of incomplete type can be taken.
3576 (And is just the ordinary address operator, not an overloaded
3577 "operator &".) However, if the type is a template
3578 specialization, we must complete the type at this point so that
3579 an overloaded "operator &" will be available if required. */
3580 if (code == ADDR_EXPR
3581 && TREE_CODE (xarg) != TEMPLATE_ID_EXPR
3582 && ((CLASS_TYPE_P (TREE_TYPE (xarg))
3583 && !COMPLETE_TYPE_P (complete_type (TREE_TYPE (xarg))))
3584 || (TREE_CODE (xarg) == OFFSET_REF)))
3585 /* Don't look for a function. */;
3587 exp = build_new_op (code, LOOKUP_NORMAL, xarg, NULL_TREE, NULL_TREE,
3588 /*overloaded_p=*/NULL);
3589 if (!exp && code == ADDR_EXPR)
3591 /* A pointer to member-function can be formed only by saying
3593 if (!flag_ms_extensions && TREE_CODE (TREE_TYPE (xarg)) == METHOD_TYPE
3594 && (TREE_CODE (xarg) != OFFSET_REF || !PTRMEM_OK_P (xarg)))
3596 if (TREE_CODE (xarg) != OFFSET_REF)
3598 error ("invalid use of %qE to form a pointer-to-member-function."
3599 " Use a qualified-id.",
3601 return error_mark_node;
3605 error ("parenthesis around %qE cannot be used to form a"
3606 " pointer-to-member-function",
3608 PTRMEM_OK_P (xarg) = 1;
3612 if (TREE_CODE (xarg) == OFFSET_REF)
3614 ptrmem = PTRMEM_OK_P (xarg);
3616 if (!ptrmem && !flag_ms_extensions
3617 && TREE_CODE (TREE_TYPE (TREE_OPERAND (xarg, 1))) == METHOD_TYPE)
3619 /* A single non-static member, make sure we don't allow a
3620 pointer-to-member. */
3621 xarg = build2 (OFFSET_REF, TREE_TYPE (xarg),
3622 TREE_OPERAND (xarg, 0),
3623 ovl_cons (TREE_OPERAND (xarg, 1), NULL_TREE));
3624 PTRMEM_OK_P (xarg) = ptrmem;
3627 else if (TREE_CODE (xarg) == TARGET_EXPR)
3628 warning ("taking address of temporary");
3629 exp = build_unary_op (ADDR_EXPR, xarg, 0);
3630 if (TREE_CODE (exp) == ADDR_EXPR)
3631 PTRMEM_OK_P (exp) = ptrmem;
3634 if (processing_template_decl && exp != error_mark_node)
3635 return build_min_non_dep (code, exp, orig_expr,
3636 /*For {PRE,POST}{INC,DEC}REMENT_EXPR*/NULL_TREE);
3640 /* Like c_common_truthvalue_conversion, but handle pointer-to-member
3641 constants, where a null value is represented by an INTEGER_CST of
3645 cp_truthvalue_conversion (tree expr)
3647 tree type = TREE_TYPE (expr);
3648 if (TYPE_PTRMEM_P (type))
3649 return build_binary_op (NE_EXPR, expr, integer_zero_node, 1);
3651 return c_common_truthvalue_conversion (expr);
3654 /* Just like cp_truthvalue_conversion, but we want a CLEANUP_POINT_EXPR. */
3657 condition_conversion (tree expr)
3660 if (processing_template_decl)
3662 t = perform_implicit_conversion (boolean_type_node, expr);
3663 t = fold_build_cleanup_point_expr (boolean_type_node, t);
3667 /* Return an ADDR_EXPR giving the address of T. This function
3668 attempts no optimizations or simplifications; it is a low-level
3672 build_address (tree t)
3676 if (error_operand_p (t) || !cxx_mark_addressable (t))
3677 return error_mark_node;
3679 addr = build1 (ADDR_EXPR, build_pointer_type (TREE_TYPE (t)), t);
3684 /* Return a NOP_EXPR converting EXPR to TYPE. */
3687 build_nop (tree type, tree expr)
3689 if (type == error_mark_node || error_operand_p (expr))
3691 return build1 (NOP_EXPR, type, expr);
3694 /* C++: Must handle pointers to members.
3696 Perhaps type instantiation should be extended to handle conversion
3697 from aggregates to types we don't yet know we want? (Or are those
3698 cases typically errors which should be reported?)
3700 NOCONVERT nonzero suppresses the default promotions
3701 (such as from short to int). */
3704 build_unary_op (enum tree_code code, tree xarg, int noconvert)
3706 /* No default_conversion here. It causes trouble for ADDR_EXPR. */
3709 const char *errstring = NULL;
3712 if (arg == error_mark_node)
3713 return error_mark_node;
3717 /* CONVERT_EXPR stands for unary plus in this context. */
3721 int flags = WANT_ARITH | WANT_ENUM;
3722 /* Unary plus (but not unary minus) is allowed on pointers. */
3723 if (code == CONVERT_EXPR)
3724 flags |= WANT_POINTER;
3725 arg = build_expr_type_conversion (flags, arg, true);
3727 errstring = (code == NEGATE_EXPR
3728 ? "wrong type argument to unary minus"
3729 : "wrong type argument to unary plus");
3732 if (!noconvert && CP_INTEGRAL_TYPE_P (TREE_TYPE (arg)))
3733 arg = perform_integral_promotions (arg);
3735 /* Make sure the result is not a lvalue: a unary plus or minus
3736 expression is always a rvalue. */
3737 if (real_lvalue_p (arg))
3738 arg = build1 (NON_LVALUE_EXPR, TREE_TYPE (arg), arg);
3744 if (TREE_CODE (TREE_TYPE (arg)) == COMPLEX_TYPE)
3748 arg = default_conversion (arg);
3750 else if (!(arg = build_expr_type_conversion (WANT_INT | WANT_ENUM,
3752 errstring = "wrong type argument to bit-complement";
3753 else if (!noconvert)
3754 arg = perform_integral_promotions (arg);
3758 if (!(arg = build_expr_type_conversion (WANT_ARITH | WANT_ENUM, arg, true)))
3759 errstring = "wrong type argument to abs";
3760 else if (!noconvert)
3761 arg = default_conversion (arg);
3765 /* Conjugating a real value is a no-op, but allow it anyway. */
3766 if (!(arg = build_expr_type_conversion (WANT_ARITH | WANT_ENUM, arg, true)))
3767 errstring = "wrong type argument to conjugation";
3768 else if (!noconvert)
3769 arg = default_conversion (arg);
3772 case TRUTH_NOT_EXPR:
3773 arg = perform_implicit_conversion (boolean_type_node, arg);
3774 val = invert_truthvalue (arg);
3775 if (arg != error_mark_node)
3777 errstring = "in argument to unary !";
3784 if (TREE_CODE (arg) == COMPLEX_CST)
3785 return TREE_REALPART (arg);
3786 else if (TREE_CODE (TREE_TYPE (arg)) == COMPLEX_TYPE)
3788 arg = build1 (REALPART_EXPR, TREE_TYPE (TREE_TYPE (arg)), arg);
3789 return fold_if_not_in_template (arg);
3795 if (TREE_CODE (arg) == COMPLEX_CST)
3796 return TREE_IMAGPART (arg);
3797 else if (TREE_CODE (TREE_TYPE (arg)) == COMPLEX_TYPE)
3799 arg = build1 (IMAGPART_EXPR, TREE_TYPE (TREE_TYPE (arg)), arg);
3800 return fold_if_not_in_template (arg);
3803 return cp_convert (TREE_TYPE (arg), integer_zero_node);
3805 case PREINCREMENT_EXPR:
3806 case POSTINCREMENT_EXPR:
3807 case PREDECREMENT_EXPR:
3808 case POSTDECREMENT_EXPR:
3809 /* Handle complex lvalues (when permitted)
3810 by reduction to simpler cases. */
3812 val = unary_complex_lvalue (code, arg);
3816 /* Increment or decrement the real part of the value,
3817 and don't change the imaginary part. */
3818 if (TREE_CODE (TREE_TYPE (arg)) == COMPLEX_TYPE)
3822 arg = stabilize_reference (arg);
3823 real = build_unary_op (REALPART_EXPR, arg, 1);
3824 imag = build_unary_op (IMAGPART_EXPR, arg, 1);
3825 return build2 (COMPLEX_EXPR, TREE_TYPE (arg),
3826 build_unary_op (code, real, 1), imag);
3829 /* Report invalid types. */
3831 if (!(arg = build_expr_type_conversion (WANT_ARITH | WANT_POINTER,
3834 if (code == PREINCREMENT_EXPR)
3835 errstring ="no pre-increment operator for type";
3836 else if (code == POSTINCREMENT_EXPR)
3837 errstring ="no post-increment operator for type";
3838 else if (code == PREDECREMENT_EXPR)
3839 errstring ="no pre-decrement operator for type";
3841 errstring ="no post-decrement operator for type";
3845 /* Report something read-only. */
3847 if (CP_TYPE_CONST_P (TREE_TYPE (arg))
3848 || TREE_READONLY (arg))
3849 readonly_error (arg, ((code == PREINCREMENT_EXPR
3850 || code == POSTINCREMENT_EXPR)
3851 ? "increment" : "decrement"),
3856 tree result_type = TREE_TYPE (arg);
3858 arg = get_unwidened (arg, 0);
3859 argtype = TREE_TYPE (arg);
3861 /* ARM $5.2.5 last annotation says this should be forbidden. */
3862 if (TREE_CODE (argtype) == ENUMERAL_TYPE)
3863 pedwarn ("ISO C++ forbids %sing an enum",
3864 (code == PREINCREMENT_EXPR || code == POSTINCREMENT_EXPR)
3865 ? "increment" : "decrement");
3867 /* Compute the increment. */
3869 if (TREE_CODE (argtype) == POINTER_TYPE)
3871 tree type = complete_type (TREE_TYPE (argtype));
3873 if (!COMPLETE_OR_VOID_TYPE_P (type))
3874 error ("cannot %s a pointer to incomplete type %qT",
3875 ((code == PREINCREMENT_EXPR
3876 || code == POSTINCREMENT_EXPR)
3877 ? "increment" : "decrement"), TREE_TYPE (argtype));
3878 else if ((pedantic || warn_pointer_arith)
3879 && !TYPE_PTROB_P (argtype))
3880 pedwarn ("ISO C++ forbids %sing a pointer of type %qT",
3881 ((code == PREINCREMENT_EXPR
3882 || code == POSTINCREMENT_EXPR)
3883 ? "increment" : "decrement"), argtype);
3884 inc = cxx_sizeof_nowarn (TREE_TYPE (argtype));
3887 inc = integer_one_node;
3889 inc = cp_convert (argtype, inc);
3891 /* Handle incrementing a cast-expression. */
3893 switch (TREE_CODE (arg))
3898 case FIX_TRUNC_EXPR:
3899 case FIX_FLOOR_EXPR:
3900 case FIX_ROUND_EXPR:
3903 tree incremented, modify, value, compound;
3904 if (! lvalue_p (arg) && pedantic)
3905 pedwarn ("cast to non-reference type used as lvalue");
3906 arg = stabilize_reference (arg);
3907 if (code == PREINCREMENT_EXPR || code == PREDECREMENT_EXPR)
3910 value = save_expr (arg);
3911 incremented = build2 (((code == PREINCREMENT_EXPR
3912 || code == POSTINCREMENT_EXPR)
3913 ? PLUS_EXPR : MINUS_EXPR),
3914 argtype, value, inc);
3916 modify = build_modify_expr (arg, NOP_EXPR, incremented);
3917 compound = build2 (COMPOUND_EXPR, TREE_TYPE (arg),
3920 /* Eliminate warning about unused result of + or -. */
3921 TREE_NO_WARNING (compound) = 1;
3929 /* Complain about anything else that is not a true lvalue. */
3930 if (!lvalue_or_else (arg, ((code == PREINCREMENT_EXPR
3931 || code == POSTINCREMENT_EXPR)
3932 ? lv_increment : lv_decrement)))
3933 return error_mark_node;
3935 /* Forbid using -- on `bool'. */
3936 if (TREE_TYPE (arg) == boolean_type_node)
3938 if (code == POSTDECREMENT_EXPR || code == PREDECREMENT_EXPR)
3940 error ("invalid use of %<--%> on bool variable %qD", arg);
3941 return error_mark_node;
3943 val = boolean_increment (code, arg);
3946 val = build2 (code, TREE_TYPE (arg), arg, inc);
3948 TREE_SIDE_EFFECTS (val) = 1;
3949 return cp_convert (result_type, val);
3953 /* Note that this operation never does default_conversion
3954 regardless of NOCONVERT. */
3956 argtype = lvalue_type (arg);
3958 if (TREE_CODE (arg) == OFFSET_REF)
3961 if (TREE_CODE (argtype) == REFERENCE_TYPE)
3963 tree type = build_pointer_type (TREE_TYPE (argtype));
3964 arg = build1 (CONVERT_EXPR, type, arg);
3967 else if (pedantic && DECL_MAIN_P (arg))
3969 pedwarn ("ISO C++ forbids taking address of function %<::main%>");
3971 /* Let &* cancel out to simplify resulting code. */
3972 if (TREE_CODE (arg) == INDIRECT_REF)
3974 /* We don't need to have `current_class_ptr' wrapped in a
3975 NON_LVALUE_EXPR node. */
3976 if (arg == current_class_ref)
3977 return current_class_ptr;
3979 arg = TREE_OPERAND (arg, 0);
3980 if (TREE_CODE (TREE_TYPE (arg)) == REFERENCE_TYPE)
3982 tree type = build_pointer_type (TREE_TYPE (TREE_TYPE (arg)));
3983 arg = build1 (CONVERT_EXPR, type, arg);
3985 else if (lvalue_p (arg))
3986 /* Don't let this be an lvalue. */
3987 return non_lvalue (arg);
3991 /* Uninstantiated types are all functions. Taking the
3992 address of a function is a no-op, so just return the
3995 gcc_assert (TREE_CODE (arg) != IDENTIFIER_NODE
3996 || !IDENTIFIER_OPNAME_P (arg));
3998 if (TREE_CODE (arg) == COMPONENT_REF && type_unknown_p (arg)
3999 && !really_overloaded_fn (TREE_OPERAND (arg, 1)))
4001 /* They're trying to take the address of a unique non-static
4002 member function. This is ill-formed (except in MS-land),
4003 but let's try to DTRT.
4004 Note: We only handle unique functions here because we don't
4005 want to complain if there's a static overload; non-unique
4006 cases will be handled by instantiate_type. But we need to
4007 handle this case here to allow casts on the resulting PMF.
4008 We could defer this in non-MS mode, but it's easier to give
4009 a useful error here. */
4011 /* Inside constant member functions, the `this' pointer
4012 contains an extra const qualifier. TYPE_MAIN_VARIANT
4013 is used here to remove this const from the diagnostics
4014 and the created OFFSET_REF. */
4015 tree base = TYPE_MAIN_VARIANT (TREE_TYPE (TREE_OPERAND (arg, 0)));
4016 tree name = DECL_NAME (get_first_fn (TREE_OPERAND (arg, 1)));
4018 if (! flag_ms_extensions)
4020 if (current_class_type
4021 && TREE_OPERAND (arg, 0) == current_class_ref)
4022 /* An expression like &memfn. */
4023 pedwarn ("ISO C++ forbids taking the address of an unqualified"
4024 " or parenthesized non-static member function to form"
4025 " a pointer to member function. Say %<&%T::%D%>",
4028 pedwarn ("ISO C++ forbids taking the address of a bound member"
4029 " function to form a pointer to member function."
4033 arg = build_offset_ref (base, name, /*address_p=*/true);
4037 if (type_unknown_p (arg))
4038 return build1 (ADDR_EXPR, unknown_type_node, arg);
4040 /* Handle complex lvalues (when permitted)
4041 by reduction to simpler cases. */
4042 val = unary_complex_lvalue (code, arg);
4046 switch (TREE_CODE (arg))
4051 case FIX_TRUNC_EXPR:
4052 case FIX_FLOOR_EXPR:
4053 case FIX_ROUND_EXPR:
4055 if (! lvalue_p (arg) && pedantic)
4056 pedwarn ("ISO C++ forbids taking the address of a cast to a non-lvalue expression");
4060 arg = OVL_CURRENT (arg);
4067 /* Allow the address of a constructor if all the elements
4069 if (TREE_CODE (arg) == CONSTRUCTOR && TREE_HAS_CONSTRUCTOR (arg)
4070 && TREE_CONSTANT (arg))
4072 /* Anything not already handled and not a true memory reference
4074 else if (TREE_CODE (argtype) != FUNCTION_TYPE
4075 && TREE_CODE (argtype) != METHOD_TYPE
4076 && !lvalue_or_else (arg, lv_addressof))
4077 return error_mark_node;
4079 if (argtype != error_mark_node)
4080 argtype = build_pointer_type (argtype);
4085 if (TREE_CODE (arg) != COMPONENT_REF
4086 /* Inside a template, we are processing a non-dependent
4087 expression so we can just form an ADDR_EXPR with the
4089 || processing_template_decl)
4090 addr = build_address (arg);
4091 else if (TREE_CODE (TREE_OPERAND (arg, 1)) == BASELINK)
4093 tree fn = BASELINK_FUNCTIONS (TREE_OPERAND (arg, 1));
4095 /* We can only get here with a single static member
4097 gcc_assert (TREE_CODE (fn) == FUNCTION_DECL
4098 && DECL_STATIC_FUNCTION_P (fn));
4100 addr = build_address (fn);
4101 if (TREE_SIDE_EFFECTS (TREE_OPERAND (arg, 0)))
4102 /* Do not lose object's side effects. */
4103 addr = build2 (COMPOUND_EXPR, TREE_TYPE (addr),
4104 TREE_OPERAND (arg, 0), addr);
4106 else if (DECL_C_BIT_FIELD (TREE_OPERAND (arg, 1)))
4108 error ("attempt to take address of bit-field structure member %qD",
4109 TREE_OPERAND (arg, 1));
4110 return error_mark_node;
4114 tree field = TREE_OPERAND (arg, 1);
4115 tree rval = build_unary_op (ADDR_EXPR, TREE_OPERAND (arg, 0), 0);
4116 tree binfo = lookup_base (TREE_TYPE (TREE_TYPE (rval)),
4117 decl_type_context (field),
4120 rval = build_base_path (PLUS_EXPR, rval, binfo, 1);
4122 TREE_OPERAND (arg, 0) = build_indirect_ref (rval, NULL);
4123 addr = build_address (arg);
4126 if (TREE_CODE (argtype) == POINTER_TYPE
4127 && TREE_CODE (TREE_TYPE (argtype)) == METHOD_TYPE)
4129 build_ptrmemfunc_type (argtype);
4130 addr = build_ptrmemfunc (argtype, addr, 0,
4131 /*c_cast_p=*/false);
4144 argtype = TREE_TYPE (arg);
4145 return fold_if_not_in_template (build1 (code, argtype, arg));
4148 error ("%s", errstring);
4149 return error_mark_node;
4152 /* Apply unary lvalue-demanding operator CODE to the expression ARG
4153 for certain kinds of expressions which are not really lvalues
4154 but which we can accept as lvalues.
4156 If ARG is not a kind of expression we can handle, return zero. */
4159 unary_complex_lvalue (enum tree_code code, tree arg)
4161 /* Handle (a, b) used as an "lvalue". */
4162 if (TREE_CODE (arg) == COMPOUND_EXPR)
4164 tree real_result = build_unary_op (code, TREE_OPERAND (arg, 1), 0);
4165 return build2 (COMPOUND_EXPR, TREE_TYPE (real_result),
4166 TREE_OPERAND (arg, 0), real_result);
4169 /* Handle (a ? b : c) used as an "lvalue". */
4170 if (TREE_CODE (arg) == COND_EXPR
4171 || TREE_CODE (arg) == MIN_EXPR || TREE_CODE (arg) == MAX_EXPR)
4172 return rationalize_conditional_expr (code, arg);
4174 /* Handle (a = b), (++a), and (--a) used as an "lvalue". */
4175 if (TREE_CODE (arg) == MODIFY_EXPR
4176 || TREE_CODE (arg) == PREINCREMENT_EXPR
4177 || TREE_CODE (arg) == PREDECREMENT_EXPR)
4179 tree lvalue = TREE_OPERAND (arg, 0);
4180 if (TREE_SIDE_EFFECTS (lvalue))
4182 lvalue = stabilize_reference (lvalue);
4183 arg = build2 (TREE_CODE (arg), TREE_TYPE (arg),
4184 lvalue, TREE_OPERAND (arg, 1));
4186 return unary_complex_lvalue
4187 (code, build2 (COMPOUND_EXPR, TREE_TYPE (lvalue), arg, lvalue));
4190 if (code != ADDR_EXPR)
4193 /* Handle (a = b) used as an "lvalue" for `&'. */
4194 if (TREE_CODE (arg) == MODIFY_EXPR
4195 || TREE_CODE (arg) == INIT_EXPR)
4197 tree real_result = build_unary_op (code, TREE_OPERAND (arg, 0), 0);
4198 arg = build2 (COMPOUND_EXPR, TREE_TYPE (real_result),
4200 TREE_NO_WARNING (arg) = 1;
4204 if (TREE_CODE (TREE_TYPE (arg)) == FUNCTION_TYPE
4205 || TREE_CODE (TREE_TYPE (arg)) == METHOD_TYPE
4206 || TREE_CODE (arg) == OFFSET_REF)
4210 gcc_assert (TREE_CODE (arg) != SCOPE_REF);
4212 if (TREE_CODE (arg) != OFFSET_REF)
4215 t = TREE_OPERAND (arg, 1);
4217 /* Check all this code for right semantics. */
4218 if (TREE_CODE (t) == FUNCTION_DECL)
4220 if (DECL_DESTRUCTOR_P (t))
4221 error ("taking address of destructor");
4222 return build_unary_op (ADDR_EXPR, t, 0);
4224 if (TREE_CODE (t) == VAR_DECL)
4225 return build_unary_op (ADDR_EXPR, t, 0);
4230 if (TREE_OPERAND (arg, 0)
4231 && ! is_dummy_object (TREE_OPERAND (arg, 0))
4232 && TREE_CODE (t) != FIELD_DECL)
4234 error ("taking address of bound pointer-to-member expression");
4235 return error_mark_node;
4237 if (!PTRMEM_OK_P (arg))
4238 return build_unary_op (code, arg, 0);
4240 if (TREE_CODE (TREE_TYPE (t)) == REFERENCE_TYPE)
4242 error ("cannot create pointer to reference member %qD", t);
4243 return error_mark_node;
4246 type = build_ptrmem_type (context_for_name_lookup (t),
4248 t = make_ptrmem_cst (type, TREE_OPERAND (arg, 1));
4254 /* We permit compiler to make function calls returning
4255 objects of aggregate type look like lvalues. */
4259 if (TREE_CODE (targ) == SAVE_EXPR)
4260 targ = TREE_OPERAND (targ, 0);
4262 if (TREE_CODE (targ) == CALL_EXPR && IS_AGGR_TYPE (TREE_TYPE (targ)))
4264 if (TREE_CODE (arg) == SAVE_EXPR)
4267 targ = build_cplus_new (TREE_TYPE (arg), arg);
4268 return build1 (ADDR_EXPR, build_pointer_type (TREE_TYPE (arg)), targ);
4271 if (TREE_CODE (arg) == SAVE_EXPR && TREE_CODE (targ) == INDIRECT_REF)
4272 return build3 (SAVE_EXPR, build_pointer_type (TREE_TYPE (arg)),
4273 TREE_OPERAND (targ, 0), current_function_decl, NULL);
4276 /* Don't let anything else be handled specially. */
4280 /* Mark EXP saying that we need to be able to take the
4281 address of it; it should not be allocated in a register.
4282 Value is true if successful.
4284 C++: we do not allow `current_class_ptr' to be addressable. */
4287 cxx_mark_addressable (tree exp)
4292 switch (TREE_CODE (x))
4299 x = TREE_OPERAND (x, 0);
4303 if (x == current_class_ptr)
4305 error ("cannot take the address of %<this%>, which is an rvalue expression");
4306 TREE_ADDRESSABLE (x) = 1; /* so compiler doesn't die later. */
4312 /* Caller should not be trying to mark initialized
4313 constant fields addressable. */
4314 gcc_assert (DECL_LANG_SPECIFIC (x) == 0
4315 || DECL_IN_AGGR_P (x) == 0
4317 || DECL_EXTERNAL (x));
4322 if (DECL_REGISTER (x) && !TREE_ADDRESSABLE (x)
4323 && !DECL_ARTIFICIAL (x))
4325 if (DECL_HARD_REGISTER (x) != 0)
4328 ("address of explicit register variable %qD requested", x);
4331 else if (extra_warnings)
4333 ("address requested for %qD, which is declared %<register%>", x);
4335 TREE_ADDRESSABLE (x) = 1;
4339 TREE_ADDRESSABLE (x) = 1;
4343 TREE_ADDRESSABLE (x) = 1;
4347 TREE_ADDRESSABLE (x) = 1;
4348 cxx_mark_addressable (TREE_OPERAND (x, 0));
4356 /* Build and return a conditional expression IFEXP ? OP1 : OP2. */
4359 build_x_conditional_expr (tree ifexp, tree op1, tree op2)
4361 tree orig_ifexp = ifexp;
4362 tree orig_op1 = op1;
4363 tree orig_op2 = op2;
4366 if (processing_template_decl)
4368 /* The standard says that the expression is type-dependent if
4369 IFEXP is type-dependent, even though the eventual type of the
4370 expression doesn't dependent on IFEXP. */
4371 if (type_dependent_expression_p (ifexp)
4372 /* As a GNU extension, the middle operand may be omitted. */
4373 || (op1 && type_dependent_expression_p (op1))
4374 || type_dependent_expression_p (op2))
4375 return build_min_nt (COND_EXPR, ifexp, op1, op2);
4376 ifexp = build_non_dependent_expr (ifexp);
4378 op1 = build_non_dependent_expr (op1);
4379 op2 = build_non_dependent_expr (op2);
4382 expr = build_conditional_expr (ifexp, op1, op2);
4383 if (processing_template_decl && expr != error_mark_node)
4384 return build_min_non_dep (COND_EXPR, expr,
4385 orig_ifexp, orig_op1, orig_op2);
4389 /* Given a list of expressions, return a compound expression
4390 that performs them all and returns the value of the last of them. */
4392 tree build_x_compound_expr_from_list (tree list, const char *msg)
4394 tree expr = TREE_VALUE (list);
4396 if (TREE_CHAIN (list))
4399 pedwarn ("%s expression list treated as compound expression", msg);
4401 for (list = TREE_CHAIN (list); list; list = TREE_CHAIN (list))
4402 expr = build_x_compound_expr (expr, TREE_VALUE (list));
4408 /* Handle overloading of the ',' operator when needed. */
4411 build_x_compound_expr (tree op1, tree op2)
4414 tree orig_op1 = op1;
4415 tree orig_op2 = op2;
4417 if (processing_template_decl)
4419 if (type_dependent_expression_p (op1)
4420 || type_dependent_expression_p (op2))
4421 return build_min_nt (COMPOUND_EXPR, op1, op2);
4422 op1 = build_non_dependent_expr (op1);
4423 op2 = build_non_dependent_expr (op2);
4426 result = build_new_op (COMPOUND_EXPR, LOOKUP_NORMAL, op1, op2, NULL_TREE,
4427 /*overloaded_p=*/NULL);
4429 result = build_compound_expr (op1, op2);
4431 if (processing_template_decl && result != error_mark_node)
4432 return build_min_non_dep (COMPOUND_EXPR, result, orig_op1, orig_op2);
4437 /* Build a compound expression. */
4440 build_compound_expr (tree lhs, tree rhs)
4442 lhs = convert_to_void (lhs, "left-hand operand of comma");
4444 if (lhs == error_mark_node || rhs == error_mark_node)
4445 return error_mark_node;
4447 if (TREE_CODE (rhs) == TARGET_EXPR)
4449 /* If the rhs is a TARGET_EXPR, then build the compound
4450 expression inside the target_expr's initializer. This
4451 helps the compiler to eliminate unnecessary temporaries. */
4452 tree init = TREE_OPERAND (rhs, 1);
4454 init = build2 (COMPOUND_EXPR, TREE_TYPE (init), lhs, init);
4455 TREE_OPERAND (rhs, 1) = init;
4460 return build2 (COMPOUND_EXPR, TREE_TYPE (rhs), lhs, rhs);
4463 /* Issue a diagnostic message if casting from SRC_TYPE to DEST_TYPE
4464 casts away constness. DIAG_FN gives the function to call if we
4465 need to issue a diagnostic; if it is NULL, no diagnostic will be
4466 issued. DESCRIPTION explains what operation is taking place. */
4469 check_for_casting_away_constness (tree src_type, tree dest_type,
4470 void (*diag_fn)(const char *, ...),
4471 const char *description)
4473 if (diag_fn && casts_away_constness (src_type, dest_type))
4474 error ("%s from type %qT to type %qT casts away constness",
4475 description, src_type, dest_type);
4478 /* Convert EXPR (an expression with pointer-to-member type) to TYPE
4479 (another pointer-to-member type in the same hierarchy) and return
4480 the converted expression. If ALLOW_INVERSE_P is permitted, a
4481 pointer-to-derived may be converted to pointer-to-base; otherwise,
4482 only the other direction is permitted. If C_CAST_P is true, this
4483 conversion is taking place as part of a C-style cast. */
4486 convert_ptrmem (tree type, tree expr, bool allow_inverse_p,
4489 if (TYPE_PTRMEM_P (type))
4493 if (TREE_CODE (expr) == PTRMEM_CST)
4494 expr = cplus_expand_constant (expr);
4495 delta = get_delta_difference (TYPE_PTRMEM_CLASS_TYPE (TREE_TYPE (expr)),
4496 TYPE_PTRMEM_CLASS_TYPE (type),
4499 if (!integer_zerop (delta))
4500 expr = cp_build_binary_op (PLUS_EXPR,
4501 build_nop (ptrdiff_type_node, expr),
4503 return build_nop (type, expr);
4506 return build_ptrmemfunc (TYPE_PTRMEMFUNC_FN_TYPE (type), expr,
4507 allow_inverse_p, c_cast_p);
4510 /* Perform a static_cast from EXPR to TYPE. When C_CAST_P is true,
4511 this static_cast is being attempted as one of the possible casts
4512 allowed by a C-style cast. (In that case, accessibility of base
4513 classes is not considered, and it is OK to cast away
4514 constness.) Return the result of the cast. *VALID_P is set to
4515 indicate whether or not the cast was valid. */
4518 build_static_cast_1 (tree type, tree expr, bool c_cast_p,
4524 void (*diag_fn)(const char*, ...);
4527 /* Assume the cast is valid. */
4530 intype = TREE_TYPE (expr);
4532 /* Determine what to do when casting away constness. */
4535 /* C-style casts are allowed to cast away constness. With
4536 WARN_CAST_QUAL, we still want to issue a warning. */
4537 diag_fn = warn_cast_qual ? warning : NULL;
4542 /* A static_cast may not cast away constness. */
4544 desc = "static_cast";
4547 /* [expr.static.cast]
4549 An lvalue of type "cv1 B", where B is a class type, can be cast
4550 to type "reference to cv2 D", where D is a class derived (clause
4551 _class.derived_) from B, if a valid standard conversion from
4552 "pointer to D" to "pointer to B" exists (_conv.ptr_), cv2 is the
4553 same cv-qualification as, or greater cv-qualification than, cv1,
4554 and B is not a virtual base class of D. */
4555 /* We check this case before checking the validity of "TYPE t =
4556 EXPR;" below because for this case:
4559 struct D : public B { D(const B&); };
4561 void f() { static_cast<const D&>(b); }
4563 we want to avoid constructing a new D. The standard is not
4564 completely clear about this issue, but our interpretation is
4565 consistent with other compilers. */
4566 if (TREE_CODE (type) == REFERENCE_TYPE
4567 && CLASS_TYPE_P (TREE_TYPE (type))
4568 && CLASS_TYPE_P (intype)
4569 && real_lvalue_p (expr)
4570 && DERIVED_FROM_P (intype, TREE_TYPE (type))
4571 && can_convert (build_pointer_type (TYPE_MAIN_VARIANT (intype)),
4572 build_pointer_type (TYPE_MAIN_VARIANT
4573 (TREE_TYPE (type))))
4575 || at_least_as_qualified_p (TREE_TYPE (type), intype)))
4579 /* There is a standard conversion from "D*" to "B*" even if "B"
4580 is ambiguous or inaccessible. If this is really a
4581 static_cast, then we check both for inaccessibility and
4582 ambiguity. However, if this is a static_cast being performed
4583 because the user wrote a C-style cast, then accessibility is
4585 base = lookup_base (TREE_TYPE (type), intype,
4586 c_cast_p ? ba_unique : ba_check,
4589 /* Convert from "B*" to "D*". This function will check that "B"
4590 is not a virtual base of "D". */
4591 expr = build_base_path (MINUS_EXPR, build_address (expr),
4592 base, /*nonnull=*/false);
4593 /* Convert the pointer to a reference -- but then remember that
4594 there are no expressions with reference type in C++. */
4595 return convert_from_reference (build_nop (type, expr));
4600 /* [expr.static.cast]
4602 An expression e can be explicitly converted to a type T using a
4603 static_cast of the form static_cast<T>(e) if the declaration T
4604 t(e);" is well-formed, for some invented temporary variable
4606 result = perform_direct_initialization_if_possible (type, expr,
4610 result = convert_from_reference (result);
4612 /* Ignore any integer overflow caused by the cast. */
4613 if (TREE_CODE (result) == INTEGER_CST
4614 && CONSTANT_CLASS_P (orig))
4616 TREE_OVERFLOW (result) = TREE_OVERFLOW (orig);
4617 TREE_CONSTANT_OVERFLOW (result)
4618 = TREE_CONSTANT_OVERFLOW (orig);
4620 /* [expr.static.cast]
4622 If T is a reference type, the result is an lvalue; otherwise,
4623 the result is an rvalue. */
4624 if (TREE_CODE (type) != REFERENCE_TYPE
4625 && real_lvalue_p (result))
4626 result = build1 (NON_LVALUE_EXPR, TREE_TYPE (result), result);
4630 /* [expr.static.cast]
4632 Any expression can be explicitly converted to type cv void. */
4633 if (TREE_CODE (type) == VOID_TYPE)
4634 return convert_to_void (expr, /*implicit=*/NULL);
4636 /* [expr.static.cast]
4638 The inverse of any standard conversion sequence (clause _conv_),
4639 other than the lvalue-to-rvalue (_conv.lval_), array-to-pointer
4640 (_conv.array_), function-to-pointer (_conv.func_), and boolean
4641 (_conv.bool_) conversions, can be performed explicitly using
4642 static_cast subject to the restriction that the explicit
4643 conversion does not cast away constness (_expr.const.cast_), and
4644 the following additional rules for specific cases: */
4645 /* For reference, the conversions not excluded are: integral
4646 promotions, floating point promotion, integral conversions,
4647 floating point conversions, floating-integral conversions,
4648 pointer conversions, and pointer to member conversions. */
4649 if ((ARITHMETIC_TYPE_P (type) && ARITHMETIC_TYPE_P (intype))
4652 A value of integral _or enumeration_ type can be explicitly
4653 converted to an enumeration type. */
4654 || (INTEGRAL_OR_ENUMERATION_TYPE_P (type)
4655 && INTEGRAL_OR_ENUMERATION_TYPE_P (intype)))
4657 expr = ocp_convert (type, expr, CONV_C_CAST, LOOKUP_NORMAL);
4659 /* Ignore any integer overflow caused by the cast. */
4660 if (TREE_CODE (expr) == INTEGER_CST
4661 && CONSTANT_CLASS_P (orig))
4663 TREE_OVERFLOW (expr) = TREE_OVERFLOW (orig);
4664 TREE_CONSTANT_OVERFLOW (expr) = TREE_CONSTANT_OVERFLOW (orig);
4669 if (TYPE_PTR_P (type) && TYPE_PTR_P (intype)
4670 && CLASS_TYPE_P (TREE_TYPE (type))
4671 && CLASS_TYPE_P (TREE_TYPE (intype))
4672 && can_convert (build_pointer_type (TYPE_MAIN_VARIANT
4673 (TREE_TYPE (intype))),
4674 build_pointer_type (TYPE_MAIN_VARIANT
4675 (TREE_TYPE (type)))))
4680 check_for_casting_away_constness (intype, type, diag_fn, desc);
4681 base = lookup_base (TREE_TYPE (type), TREE_TYPE (intype),
4682 c_cast_p ? ba_unique : ba_check,
4684 return build_base_path (MINUS_EXPR, expr, base, /*nonnull=*/false);
4687 if ((TYPE_PTRMEM_P (type) && TYPE_PTRMEM_P (intype))
4688 || (TYPE_PTRMEMFUNC_P (type) && TYPE_PTRMEMFUNC_P (intype)))
4695 c1 = TYPE_PTRMEM_CLASS_TYPE (intype);
4696 c2 = TYPE_PTRMEM_CLASS_TYPE (type);
4698 if (TYPE_PTRMEM_P (type))
4700 t1 = (build_ptrmem_type
4702 TYPE_MAIN_VARIANT (TYPE_PTRMEM_POINTED_TO_TYPE (intype))));
4703 t2 = (build_ptrmem_type
4705 TYPE_MAIN_VARIANT (TYPE_PTRMEM_POINTED_TO_TYPE (type))));
4712 if (can_convert (t1, t2))
4715 check_for_casting_away_constness (intype, type, diag_fn,
4717 return convert_ptrmem (type, expr, /*allow_inverse_p=*/1,
4722 /* [expr.static.cast]
4724 An rvalue of type "pointer to cv void" can be explicitly
4725 converted to a pointer to object type. A value of type pointer
4726 to object converted to "pointer to cv void" and back to the
4727 original pointer type will have its original value. */
4728 if (TREE_CODE (intype) == POINTER_TYPE
4729 && VOID_TYPE_P (TREE_TYPE (intype))
4730 && TYPE_PTROB_P (type))
4733 check_for_casting_away_constness (intype, type, diag_fn, desc);
4734 return build_nop (type, expr);
4738 return error_mark_node;
4741 /* Return an expression representing static_cast<TYPE>(EXPR). */
4744 build_static_cast (tree type, tree expr)
4749 if (type == error_mark_node || expr == error_mark_node)
4750 return error_mark_node;
4752 if (processing_template_decl)
4754 expr = build_min (STATIC_CAST_EXPR, type, expr);
4755 /* We don't know if it will or will not have side effects. */
4756 TREE_SIDE_EFFECTS (expr) = 1;
4757 return convert_from_reference (expr);
4760 /* build_c_cast puts on a NOP_EXPR to make the result not an lvalue.
4761 Strip such NOP_EXPRs if VALUE is being used in non-lvalue context. */
4762 if (TREE_CODE (type) != REFERENCE_TYPE
4763 && TREE_CODE (expr) == NOP_EXPR
4764 && TREE_TYPE (expr) == TREE_TYPE (TREE_OPERAND (expr, 0)))
4765 expr = TREE_OPERAND (expr, 0);
4767 result = build_static_cast_1 (type, expr, /*c_cast_p=*/false, &valid_p);
4771 error ("invalid static_cast from type %qT to type %qT",
4772 TREE_TYPE (expr), type);
4773 return error_mark_node;
4776 /* EXPR is an expression with member function or pointer-to-member
4777 function type. TYPE is a pointer type. Converting EXPR to TYPE is
4778 not permitted by ISO C++, but we accept it in some modes. If we
4779 are not in one of those modes, issue a diagnostic. Return the
4780 converted expression. */
4783 convert_member_func_to_ptr (tree type, tree expr)
4788 intype = TREE_TYPE (expr);
4789 gcc_assert (TYPE_PTRMEMFUNC_P (intype)
4790 || TREE_CODE (intype) == METHOD_TYPE);
4792 if (pedantic || warn_pmf2ptr)
4793 pedwarn ("converting from %qT to %qT", intype, type);
4795 if (TREE_CODE (intype) == METHOD_TYPE)
4796 expr = build_addr_func (expr);
4797 else if (TREE_CODE (expr) == PTRMEM_CST)
4798 expr = build_address (PTRMEM_CST_MEMBER (expr));
4801 decl = maybe_dummy_object (TYPE_PTRMEM_CLASS_TYPE (intype), 0);
4802 decl = build_address (decl);
4803 expr = get_member_function_from_ptrfunc (&decl, expr);
4806 return build_nop (type, expr);
4809 /* Return a representation for a reinterpret_cast from EXPR to TYPE.
4810 If C_CAST_P is true, this reinterpret cast is being done as part of
4811 a C-style cast. If VALID_P is non-NULL, *VALID_P is set to
4812 indicate whether or not reinterpret_cast was valid. */
4815 build_reinterpret_cast_1 (tree type, tree expr, bool c_cast_p,
4820 /* Assume the cast is invalid. */
4824 if (type == error_mark_node || error_operand_p (expr))
4825 return error_mark_node;
4827 intype = TREE_TYPE (expr);
4829 /* [expr.reinterpret.cast]
4830 An lvalue expression of type T1 can be cast to the type
4831 "reference to T2" if an expression of type "pointer to T1" can be
4832 explicitly converted to the type "pointer to T2" using a
4833 reinterpret_cast. */
4834 if (TREE_CODE (type) == REFERENCE_TYPE)
4836 if (! real_lvalue_p (expr))
4838 error ("invalid cast of an rvalue expression of type "
4841 return error_mark_node;
4844 /* Warn about a reinterpret_cast from "A*" to "B&" if "A" and
4845 "B" are related class types; the reinterpret_cast does not
4846 adjust the pointer. */
4847 if (TYPE_PTR_P (intype)
4848 && (comptypes (TREE_TYPE (intype), TREE_TYPE (type),
4849 COMPARE_BASE | COMPARE_DERIVED)))
4850 warning ("casting %qT to %qT does not dereference pointer",
4853 expr = build_unary_op (ADDR_EXPR, expr, 0);
4854 if (expr != error_mark_node)
4855 expr = build_reinterpret_cast_1
4856 (build_pointer_type (TREE_TYPE (type)), expr, c_cast_p,
4858 if (expr != error_mark_node)
4859 expr = build_indirect_ref (expr, 0);
4863 /* As a G++ extension, we consider conversions from member
4864 functions, and pointers to member functions to
4865 pointer-to-function and pointer-to-void types. If
4866 -Wno-pmf-conversions has not been specified,
4867 convert_member_func_to_ptr will issue an error message. */
4868 if ((TYPE_PTRMEMFUNC_P (intype)
4869 || TREE_CODE (intype) == METHOD_TYPE)
4870 && TYPE_PTR_P (type)
4871 && (TREE_CODE (TREE_TYPE (type)) == FUNCTION_TYPE
4872 || VOID_TYPE_P (TREE_TYPE (type))))
4873 return convert_member_func_to_ptr (type, expr);
4875 /* If the cast is not to a reference type, the lvalue-to-rvalue,
4876 array-to-pointer, and function-to-pointer conversions are
4878 expr = decay_conversion (expr);
4880 /* build_c_cast puts on a NOP_EXPR to make the result not an lvalue.
4881 Strip such NOP_EXPRs if VALUE is being used in non-lvalue context. */
4882 if (TREE_CODE (expr) == NOP_EXPR
4883 && TREE_TYPE (expr) == TREE_TYPE (TREE_OPERAND (expr, 0)))
4884 expr = TREE_OPERAND (expr, 0);
4886 if (error_operand_p (expr))
4887 return error_mark_node;
4889 intype = TREE_TYPE (expr);
4891 /* [expr.reinterpret.cast]
4892 A pointer can be converted to any integral type large enough to
4894 if (CP_INTEGRAL_TYPE_P (type) && TYPE_PTR_P (intype))
4896 if (TYPE_PRECISION (type) < TYPE_PRECISION (intype))
4897 pedwarn ("cast from %qT to %qT loses precision",
4900 /* [expr.reinterpret.cast]
4901 A value of integral or enumeration type can be explicitly
4902 converted to a pointer. */
4903 else if (TYPE_PTR_P (type) && INTEGRAL_OR_ENUMERATION_TYPE_P (intype))
4906 else if ((TYPE_PTRFN_P (type) && TYPE_PTRFN_P (intype))
4907 || (TYPE_PTRMEMFUNC_P (type) && TYPE_PTRMEMFUNC_P (intype)))
4908 return fold_if_not_in_template (build_nop (type, expr));
4909 else if ((TYPE_PTRMEM_P (type) && TYPE_PTRMEM_P (intype))
4910 || (TYPE_PTROBV_P (type) && TYPE_PTROBV_P (intype)))
4913 check_for_casting_away_constness (intype, type, error,
4914 "reinterpret_cast");
4915 /* Warn about possible alignment problems. */
4916 if (STRICT_ALIGNMENT && warn_cast_align
4917 && !VOID_TYPE_P (type)
4918 && TREE_CODE (TREE_TYPE (intype)) != FUNCTION_TYPE
4919 && COMPLETE_TYPE_P (TREE_TYPE (type))
4920 && COMPLETE_TYPE_P (TREE_TYPE (intype))
4921 && TYPE_ALIGN (TREE_TYPE (type)) > TYPE_ALIGN (TREE_TYPE (intype)))
4922 warning ("cast from %qT to %qT increases required alignment of "
4926 return fold_if_not_in_template (build_nop (type, expr));
4928 else if ((TYPE_PTRFN_P (type) && TYPE_PTROBV_P (intype))
4929 || (TYPE_PTRFN_P (intype) && TYPE_PTROBV_P (type)))
4932 /* Only issue a warning, as we have always supported this
4933 where possible, and it is necessary in some cases. DR 195
4934 addresses this issue, but as of 2004/10/26 is still in
4936 warning ("ISO C++ forbids casting between pointer-to-function and pointer-to-object");
4937 return fold_if_not_in_template (build_nop (type, expr));
4939 else if (TREE_CODE (type) == VECTOR_TYPE)
4940 return fold_if_not_in_template (convert_to_vector (type, expr));
4941 else if (TREE_CODE (intype) == VECTOR_TYPE)
4942 return fold_if_not_in_template (convert_to_integer (type, expr));
4947 error ("invalid cast from type %qT to type %qT", intype, type);
4948 return error_mark_node;
4951 return cp_convert (type, expr);
4955 build_reinterpret_cast (tree type, tree expr)
4957 if (type == error_mark_node || expr == error_mark_node)
4958 return error_mark_node;
4960 if (processing_template_decl)
4962 tree t = build_min (REINTERPRET_CAST_EXPR, type, expr);
4964 if (!TREE_SIDE_EFFECTS (t)
4965 && type_dependent_expression_p (expr))
4966 /* There might turn out to be side effects inside expr. */
4967 TREE_SIDE_EFFECTS (t) = 1;
4968 return convert_from_reference (t);
4971 return build_reinterpret_cast_1 (type, expr, /*c_cast_p=*/false,
4975 /* Perform a const_cast from EXPR to TYPE. If the cast is valid,
4976 return an appropriate expression. Otherwise, return
4977 error_mark_node. If the cast is not valid, and COMPLAIN is true,
4978 then a diagnostic will be issued. If VALID_P is non-NULL, its
4979 value upon return will indicate whether or not the conversion
4983 build_const_cast_1 (tree dst_type, tree expr, bool complain,
4987 tree reference_type;
4989 /* Callers are responsible for handling error_mark_node as a
4990 destination type. */
4991 gcc_assert (dst_type != error_mark_node);
4992 /* In a template, callers should be building syntactic
4993 representations of casts, not using this machinery. */
4994 gcc_assert (!processing_template_decl);
4996 /* Assume the conversion is invalid. */
5000 if (!POINTER_TYPE_P (dst_type) && !TYPE_PTRMEM_P (dst_type))
5003 error ("invalid use of const_cast with type %qT, "
5004 "which is not a pointer, "
5005 "reference, nor a pointer-to-data-member type", dst_type);
5006 return error_mark_node;
5009 if (TREE_CODE (TREE_TYPE (dst_type)) == FUNCTION_TYPE)
5012 error ("invalid use of const_cast with type %qT, which is a pointer "
5013 "or reference to a function type", dst_type);
5014 return error_mark_node;
5017 src_type = TREE_TYPE (expr);
5018 /* Expressions do not really have reference types. */
5019 if (TREE_CODE (src_type) == REFERENCE_TYPE)
5020 src_type = TREE_TYPE (src_type);
5022 /* [expr.const.cast]
5024 An lvalue of type T1 can be explicitly converted to an lvalue of
5025 type T2 using the cast const_cast<T2&> (where T1 and T2 are object
5026 types) if a pointer to T1 can be explicitly converted to the type
5027 pointer to T2 using a const_cast. */
5028 if (TREE_CODE (dst_type) == REFERENCE_TYPE)
5030 reference_type = dst_type;
5031 if (! real_lvalue_p (expr))
5034 error ("invalid const_cast of an rvalue of type %qT to type %qT",
5035 src_type, dst_type);
5036 return error_mark_node;
5038 dst_type = build_pointer_type (TREE_TYPE (dst_type));
5039 src_type = build_pointer_type (src_type);
5043 reference_type = NULL_TREE;
5044 /* If the destination type is not a reference type, the
5045 lvalue-to-rvalue, array-to-pointer, and function-to-pointer
5046 conversions are performed. */
5047 src_type = type_decays_to (src_type);
5048 if (src_type == error_mark_node)
5049 return error_mark_node;
5052 if ((TYPE_PTR_P (src_type) || TYPE_PTRMEM_P (src_type))
5053 && comp_ptr_ttypes_const (dst_type, src_type))
5059 expr = build_unary_op (ADDR_EXPR, expr, 0);
5060 expr = build_nop (reference_type, expr);
5061 return convert_from_reference (expr);
5065 expr = decay_conversion (expr);
5066 /* build_c_cast puts on a NOP_EXPR to make the result not an
5067 lvalue. Strip such NOP_EXPRs if VALUE is being used in
5068 non-lvalue context. */
5069 if (TREE_CODE (expr) == NOP_EXPR
5070 && TREE_TYPE (expr) == TREE_TYPE (TREE_OPERAND (expr, 0)))
5071 expr = TREE_OPERAND (expr, 0);
5072 return build_nop (dst_type, expr);
5077 error ("invalid const_cast from type %qT to type %qT",
5078 src_type, dst_type);
5079 return error_mark_node;
5083 build_const_cast (tree type, tree expr)
5085 if (type == error_mark_node || error_operand_p (expr))
5086 return error_mark_node;
5088 if (processing_template_decl)
5090 tree t = build_min (CONST_CAST_EXPR, type, expr);
5092 if (!TREE_SIDE_EFFECTS (t)
5093 && type_dependent_expression_p (expr))
5094 /* There might turn out to be side effects inside expr. */
5095 TREE_SIDE_EFFECTS (t) = 1;
5096 return convert_from_reference (t);
5099 return build_const_cast_1 (type, expr, /*complain=*/true,
5103 /* Build an expression representing an explicit C-style cast to type
5104 TYPE of expression EXPR. */
5107 build_c_cast (tree type, tree expr)
5113 if (type == error_mark_node || error_operand_p (expr))
5114 return error_mark_node;
5116 if (processing_template_decl)
5118 tree t = build_min (CAST_EXPR, type,
5119 tree_cons (NULL_TREE, value, NULL_TREE));
5120 /* We don't know if it will or will not have side effects. */
5121 TREE_SIDE_EFFECTS (t) = 1;
5122 return convert_from_reference (t);
5125 /* Casts to a (pointer to a) specific ObjC class (or 'id' or
5126 'Class') should always be retained, because this information aids
5127 in method lookup. */
5128 if (objc_is_object_ptr (type)
5129 && objc_is_object_ptr (TREE_TYPE (expr)))
5130 return build_nop (type, expr);
5132 /* build_c_cast puts on a NOP_EXPR to make the result not an lvalue.
5133 Strip such NOP_EXPRs if VALUE is being used in non-lvalue context. */
5134 if (TREE_CODE (type) != REFERENCE_TYPE
5135 && TREE_CODE (value) == NOP_EXPR
5136 && TREE_TYPE (value) == TREE_TYPE (TREE_OPERAND (value, 0)))
5137 value = TREE_OPERAND (value, 0);
5139 if (TREE_CODE (type) == ARRAY_TYPE)
5141 /* Allow casting from T1* to T2[] because Cfront allows it.
5142 NIHCL uses it. It is not valid ISO C++ however. */
5143 if (TREE_CODE (TREE_TYPE (expr)) == POINTER_TYPE)
5145 pedwarn ("ISO C++ forbids casting to an array type %qT", type);
5146 type = build_pointer_type (TREE_TYPE (type));
5150 error ("ISO C++ forbids casting to an array type %qT", type);
5151 return error_mark_node;
5155 if (TREE_CODE (type) == FUNCTION_TYPE
5156 || TREE_CODE (type) == METHOD_TYPE)
5158 error ("invalid cast to function type %qT", type);
5159 return error_mark_node;
5162 /* A C-style cast can be a const_cast. */
5163 result = build_const_cast_1 (type, value, /*complain=*/false,
5168 /* Or a static cast. */
5169 result = build_static_cast_1 (type, value, /*c_cast_p=*/true,
5171 /* Or a reinterpret_cast. */
5173 result = build_reinterpret_cast_1 (type, value, /*c_cast_p=*/true,
5175 /* The static_cast or reinterpret_cast may be followed by a
5178 /* A valid cast may result in errors if, for example, a
5179 conversion to am ambiguous base class is required. */
5180 && !error_operand_p (result))
5184 /* Non-class rvalues always have cv-unqualified type. */
5185 if (!CLASS_TYPE_P (type))
5186 type = TYPE_MAIN_VARIANT (type);
5187 result_type = TREE_TYPE (result);
5188 if (!CLASS_TYPE_P (result_type))
5189 result_type = TYPE_MAIN_VARIANT (result_type);
5190 /* If the type of RESULT does not match TYPE, perform a
5191 const_cast to make it match. If the static_cast or
5192 reinterpret_cast succeeded, we will differ by at most
5193 cv-qualification, so the follow-on const_cast is guaranteed
5195 if (!same_type_p (non_reference (type), non_reference (result_type)))
5197 result = build_const_cast_1 (type, result, false, &valid_p);
5198 gcc_assert (valid_p);
5203 return error_mark_node;
5206 /* Build an assignment expression of lvalue LHS from value RHS.
5207 MODIFYCODE is the code for a binary operator that we use
5208 to combine the old value of LHS with RHS to get the new value.
5209 Or else MODIFYCODE is NOP_EXPR meaning do a simple assignment.
5211 C++: If MODIFYCODE is INIT_EXPR, then leave references unbashed. */
5214 build_modify_expr (tree lhs, enum tree_code modifycode, tree rhs)
5218 tree lhstype = TREE_TYPE (lhs);
5219 tree olhstype = lhstype;
5220 tree olhs = NULL_TREE;
5221 bool plain_assign = (modifycode == NOP_EXPR);
5223 /* Avoid duplicate error messages from operands that had errors. */
5224 if (lhs == error_mark_node || rhs == error_mark_node)
5225 return error_mark_node;
5227 /* Handle control structure constructs used as "lvalues". */
5228 switch (TREE_CODE (lhs))
5230 /* Handle --foo = 5; as these are valid constructs in C++. */
5231 case PREDECREMENT_EXPR:
5232 case PREINCREMENT_EXPR:
5233 if (TREE_SIDE_EFFECTS (TREE_OPERAND (lhs, 0)))
5234 lhs = build2 (TREE_CODE (lhs), TREE_TYPE (lhs),
5235 stabilize_reference (TREE_OPERAND (lhs, 0)),
5236 TREE_OPERAND (lhs, 1));
5237 return build2 (COMPOUND_EXPR, lhstype,
5239 build_modify_expr (TREE_OPERAND (lhs, 0),
5242 /* Handle (a, b) used as an "lvalue". */
5244 newrhs = build_modify_expr (TREE_OPERAND (lhs, 1),
5246 if (newrhs == error_mark_node)
5247 return error_mark_node;
5248 return build2 (COMPOUND_EXPR, lhstype,
5249 TREE_OPERAND (lhs, 0), newrhs);
5252 if (TREE_SIDE_EFFECTS (TREE_OPERAND (lhs, 0)))
5253 lhs = build2 (TREE_CODE (lhs), TREE_TYPE (lhs),
5254 stabilize_reference (TREE_OPERAND (lhs, 0)),
5255 TREE_OPERAND (lhs, 1));
5256 newrhs = build_modify_expr (TREE_OPERAND (lhs, 0), modifycode, rhs);
5257 if (newrhs == error_mark_node)
5258 return error_mark_node;
5259 return build2 (COMPOUND_EXPR, lhstype, lhs, newrhs);
5263 /* MIN_EXPR and MAX_EXPR are currently only permitted as lvalues,
5264 when neither operand has side-effects. */
5265 if (!lvalue_or_else (lhs, lv_assign))
5266 return error_mark_node;
5268 gcc_assert (!TREE_SIDE_EFFECTS (TREE_OPERAND (lhs, 0))
5269 && !TREE_SIDE_EFFECTS (TREE_OPERAND (lhs, 1)));
5271 lhs = build3 (COND_EXPR, TREE_TYPE (lhs),
5272 build2 (TREE_CODE (lhs) == MIN_EXPR ? LE_EXPR : GE_EXPR,
5274 TREE_OPERAND (lhs, 0),
5275 TREE_OPERAND (lhs, 1)),
5276 TREE_OPERAND (lhs, 0),
5277 TREE_OPERAND (lhs, 1));
5280 /* Handle (a ? b : c) used as an "lvalue". */
5283 /* Produce (a ? (b = rhs) : (c = rhs))
5284 except that the RHS goes through a save-expr
5285 so the code to compute it is only emitted once. */
5287 tree preeval = NULL_TREE;
5289 rhs = stabilize_expr (rhs, &preeval);
5291 /* Check this here to avoid odd errors when trying to convert
5292 a throw to the type of the COND_EXPR. */
5293 if (!lvalue_or_else (lhs, lv_assign))
5294 return error_mark_node;
5296 cond = build_conditional_expr
5297 (TREE_OPERAND (lhs, 0),
5298 build_modify_expr (cp_convert (TREE_TYPE (lhs),
5299 TREE_OPERAND (lhs, 1)),
5301 build_modify_expr (cp_convert (TREE_TYPE (lhs),
5302 TREE_OPERAND (lhs, 2)),
5305 if (cond == error_mark_node)
5307 /* Make sure the code to compute the rhs comes out
5308 before the split. */
5310 cond = build2 (COMPOUND_EXPR, TREE_TYPE (lhs), preeval, cond);
5318 if (modifycode == INIT_EXPR)
5320 if (TREE_CODE (rhs) == CONSTRUCTOR)
5322 if (! same_type_p (TREE_TYPE (rhs), lhstype))
5323 /* Call convert to generate an error; see PR 11063. */
5324 rhs = convert (lhstype, rhs);
5325 result = build2 (INIT_EXPR, lhstype, lhs, rhs);
5326 TREE_SIDE_EFFECTS (result) = 1;
5329 else if (! IS_AGGR_TYPE (lhstype))
5330 /* Do the default thing. */;
5333 result = build_special_member_call (lhs, complete_ctor_identifier,
5334 build_tree_list (NULL_TREE, rhs),
5335 lhstype, LOOKUP_NORMAL);
5336 if (result == NULL_TREE)
5337 return error_mark_node;
5343 lhs = require_complete_type (lhs);
5344 if (lhs == error_mark_node)
5345 return error_mark_node;
5347 if (modifycode == NOP_EXPR)
5349 /* `operator=' is not an inheritable operator. */
5350 if (! IS_AGGR_TYPE (lhstype))
5351 /* Do the default thing. */;
5354 result = build_new_op (MODIFY_EXPR, LOOKUP_NORMAL,
5355 lhs, rhs, make_node (NOP_EXPR),
5356 /*overloaded_p=*/NULL);
5357 if (result == NULL_TREE)
5358 return error_mark_node;
5365 /* A binary op has been requested. Combine the old LHS
5366 value with the RHS producing the value we should actually
5367 store into the LHS. */
5369 gcc_assert (!PROMOTES_TO_AGGR_TYPE (lhstype, REFERENCE_TYPE));
5370 lhs = stabilize_reference (lhs);
5371 newrhs = cp_build_binary_op (modifycode, lhs, rhs);
5372 if (newrhs == error_mark_node)
5374 error (" in evaluation of %<%Q(%#T, %#T)%>", modifycode,
5375 TREE_TYPE (lhs), TREE_TYPE (rhs));
5376 return error_mark_node;
5379 /* Now it looks like a plain assignment. */
5380 modifycode = NOP_EXPR;
5382 gcc_assert (TREE_CODE (lhstype) != REFERENCE_TYPE);
5383 gcc_assert (TREE_CODE (TREE_TYPE (newrhs)) != REFERENCE_TYPE);
5386 /* The left-hand side must be an lvalue. */
5387 if (!lvalue_or_else (lhs, lv_assign))
5388 return error_mark_node;
5390 /* Warn about modifying something that is `const'. Don't warn if
5391 this is initialization. */
5392 if (modifycode != INIT_EXPR
5393 && (TREE_READONLY (lhs) || CP_TYPE_CONST_P (lhstype)
5394 /* Functions are not modifiable, even though they are
5396 || TREE_CODE (TREE_TYPE (lhs)) == FUNCTION_TYPE
5397 || TREE_CODE (TREE_TYPE (lhs)) == METHOD_TYPE
5398 /* If it's an aggregate and any field is const, then it is
5399 effectively const. */
5400 || (CLASS_TYPE_P (lhstype)
5401 && C_TYPE_FIELDS_READONLY (lhstype))))
5402 readonly_error (lhs, "assignment", 0);
5404 /* If storing into a structure or union member, it has probably been
5405 given type `int'. Compute the type that would go with the actual
5406 amount of storage the member occupies. */
5408 if (TREE_CODE (lhs) == COMPONENT_REF
5409 && (TREE_CODE (lhstype) == INTEGER_TYPE
5410 || TREE_CODE (lhstype) == REAL_TYPE
5411 || TREE_CODE (lhstype) == ENUMERAL_TYPE))
5413 lhstype = TREE_TYPE (get_unwidened (lhs, 0));
5415 /* If storing in a field that is in actuality a short or narrower
5416 than one, we must store in the field in its actual type. */
5418 if (lhstype != TREE_TYPE (lhs))
5420 /* Avoid warnings converting integral types back into enums for
5422 if (TREE_CODE (lhstype) == INTEGER_TYPE
5423 && TREE_CODE (olhstype) == ENUMERAL_TYPE)
5425 if (TREE_SIDE_EFFECTS (lhs))
5426 lhs = stabilize_reference (lhs);
5429 lhs = copy_node (lhs);
5430 TREE_TYPE (lhs) = lhstype;
5434 /* Convert new value to destination type. */
5436 if (TREE_CODE (lhstype) == ARRAY_TYPE)
5440 if (!same_or_base_type_p (TYPE_MAIN_VARIANT (lhstype),
5441 TYPE_MAIN_VARIANT (TREE_TYPE (rhs))))
5443 error ("incompatible types in assignment of %qT to %qT",
5444 TREE_TYPE (rhs), lhstype);
5445 return error_mark_node;
5448 /* Allow array assignment in compiler-generated code. */
5449 if (! DECL_ARTIFICIAL (current_function_decl))
5450 pedwarn ("ISO C++ forbids assignment of arrays");
5452 from_array = TREE_CODE (TREE_TYPE (newrhs)) == ARRAY_TYPE
5453 ? 1 + (modifycode != INIT_EXPR): 0;
5454 return build_vec_init (lhs, NULL_TREE, newrhs, from_array);
5457 if (modifycode == INIT_EXPR)
5458 newrhs = convert_for_initialization (lhs, lhstype, newrhs, LOOKUP_NORMAL,
5459 "initialization", NULL_TREE, 0);
5462 /* Avoid warnings on enum bit fields. */
5463 if (TREE_CODE (olhstype) == ENUMERAL_TYPE
5464 && TREE_CODE (lhstype) == INTEGER_TYPE)
5466 newrhs = convert_for_assignment (olhstype, newrhs, "assignment",
5468 newrhs = convert_force (lhstype, newrhs, 0);
5471 newrhs = convert_for_assignment (lhstype, newrhs, "assignment",
5473 if (TREE_CODE (newrhs) == CALL_EXPR
5474 && TYPE_NEEDS_CONSTRUCTING (lhstype))
5475 newrhs = build_cplus_new (lhstype, newrhs);
5477 /* Can't initialize directly from a TARGET_EXPR, since that would
5478 cause the lhs to be constructed twice, and possibly result in
5479 accidental self-initialization. So we force the TARGET_EXPR to be
5480 expanded without a target. */
5481 if (TREE_CODE (newrhs) == TARGET_EXPR)
5482 newrhs = build2 (COMPOUND_EXPR, TREE_TYPE (newrhs), newrhs,
5483 TREE_OPERAND (newrhs, 0));
5486 if (newrhs == error_mark_node)
5487 return error_mark_node;
5489 result = build2 (modifycode == NOP_EXPR ? MODIFY_EXPR : INIT_EXPR,
5490 lhstype, lhs, newrhs);
5492 TREE_SIDE_EFFECTS (result) = 1;
5494 TREE_NO_WARNING (result) = 1;
5496 /* If we got the LHS in a different type for storing in,
5497 convert the result back to the nominal type of LHS
5498 so that the value we return always has the same type
5499 as the LHS argument. */
5501 if (olhstype == TREE_TYPE (result))
5505 result = build2 (COMPOUND_EXPR, olhstype, result, olhs);
5506 TREE_NO_WARNING (result) = 1;
5509 return convert_for_assignment (olhstype, result, "assignment",
5514 build_x_modify_expr (tree lhs, enum tree_code modifycode, tree rhs)
5516 if (processing_template_decl)
5517 return build_min_nt (MODOP_EXPR, lhs,
5518 build_min_nt (modifycode, NULL_TREE, NULL_TREE), rhs);
5520 if (modifycode != NOP_EXPR)
5522 tree rval = build_new_op (MODIFY_EXPR, LOOKUP_NORMAL, lhs, rhs,
5523 make_node (modifycode),
5524 /*overloaded_p=*/NULL);
5527 TREE_NO_WARNING (rval) = 1;
5531 return build_modify_expr (lhs, modifycode, rhs);
5535 /* Get difference in deltas for different pointer to member function
5536 types. Returns an integer constant of type PTRDIFF_TYPE_NODE. If
5537 the conversion is invalid, the constant is zero. If
5538 ALLOW_INVERSE_P is true, then allow reverse conversions as well.
5539 If C_CAST_P is true this conversion is taking place as part of a
5542 Note that the naming of FROM and TO is kind of backwards; the return
5543 value is what we add to a TO in order to get a FROM. They are named
5544 this way because we call this function to find out how to convert from
5545 a pointer to member of FROM to a pointer to member of TO. */
5548 get_delta_difference (tree from, tree to,
5549 bool allow_inverse_p,
5557 /* Assume no conversion is required. */
5558 result = integer_zero_node;
5559 binfo = lookup_base (to, from, c_cast_p ? ba_unique : ba_check, &kind);
5560 if (kind == bk_inaccessible || kind == bk_ambig)
5561 error (" in pointer to member function conversion");
5564 if (!allow_inverse_p)
5566 error_not_base_type (from, to);
5567 error (" in pointer to member conversion");
5571 binfo = lookup_base (from, to, c_cast_p ? ba_unique : ba_check,
5575 virt_binfo = binfo_from_vbase (binfo);
5577 /* This is a reinterpret cast, we choose to do nothing. */
5578 warning ("pointer to member cast via virtual base %qT",
5579 BINFO_TYPE (virt_binfo));
5581 result = size_diffop (size_zero_node, BINFO_OFFSET (binfo));
5587 virt_binfo = binfo_from_vbase (binfo);
5589 result = BINFO_OFFSET (binfo);
5592 /* This is a reinterpret cast, we choose to do nothing. */
5593 if (allow_inverse_p)
5594 warning ("pointer to member cast via virtual base %qT",
5595 BINFO_TYPE (virt_binfo));
5597 error ("pointer to member conversion via virtual base %qT",
5598 BINFO_TYPE (virt_binfo));
5602 return fold_if_not_in_template (convert_to_integer (ptrdiff_type_node,
5606 /* Return a constructor for the pointer-to-member-function TYPE using
5607 the other components as specified. */
5610 build_ptrmemfunc1 (tree type, tree delta, tree pfn)
5616 /* Pull the FIELD_DECLs out of the type. */
5617 pfn_field = TYPE_FIELDS (type);
5618 delta_field = TREE_CHAIN (pfn_field);
5620 /* Make sure DELTA has the type we want. */
5621 delta = convert_and_check (delta_type_node, delta);
5623 /* Finish creating the initializer. */
5624 u = tree_cons (pfn_field, pfn,
5625 build_tree_list (delta_field, delta));
5626 u = build_constructor (type, u);
5627 TREE_CONSTANT (u) = TREE_CONSTANT (pfn) & TREE_CONSTANT (delta);
5628 TREE_INVARIANT (u) = TREE_INVARIANT (pfn) & TREE_INVARIANT (delta);
5629 TREE_STATIC (u) = (TREE_CONSTANT (u)
5630 && (initializer_constant_valid_p (pfn, TREE_TYPE (pfn))
5632 && (initializer_constant_valid_p (delta, TREE_TYPE (delta))
5637 /* Build a constructor for a pointer to member function. It can be
5638 used to initialize global variables, local variable, or used
5639 as a value in expressions. TYPE is the POINTER to METHOD_TYPE we
5642 If FORCE is nonzero, then force this conversion, even if
5643 we would rather not do it. Usually set when using an explicit
5644 cast. A C-style cast is being processed iff C_CAST_P is true.
5646 Return error_mark_node, if something goes wrong. */
5649 build_ptrmemfunc (tree type, tree pfn, int force, bool c_cast_p)
5655 if (error_operand_p (pfn))
5656 return error_mark_node;
5658 pfn_type = TREE_TYPE (pfn);
5659 to_type = build_ptrmemfunc_type (type);
5661 /* Handle multiple conversions of pointer to member functions. */
5662 if (TYPE_PTRMEMFUNC_P (pfn_type))
5664 tree delta = NULL_TREE;
5665 tree npfn = NULL_TREE;
5669 && !can_convert_arg (to_type, TREE_TYPE (pfn), pfn))
5670 error ("invalid conversion to type %qT from type %qT",
5673 n = get_delta_difference (TYPE_PTRMEMFUNC_OBJECT_TYPE (pfn_type),
5674 TYPE_PTRMEMFUNC_OBJECT_TYPE (to_type),
5678 /* We don't have to do any conversion to convert a
5679 pointer-to-member to its own type. But, we don't want to
5680 just return a PTRMEM_CST if there's an explicit cast; that
5681 cast should make the expression an invalid template argument. */
5682 if (TREE_CODE (pfn) != PTRMEM_CST)
5684 if (same_type_p (to_type, pfn_type))
5686 else if (integer_zerop (n))
5687 return build_reinterpret_cast (to_type, pfn);
5690 if (TREE_SIDE_EFFECTS (pfn))
5691 pfn = save_expr (pfn);
5693 /* Obtain the function pointer and the current DELTA. */
5694 if (TREE_CODE (pfn) == PTRMEM_CST)
5695 expand_ptrmemfunc_cst (pfn, &delta, &npfn);
5698 npfn = build_ptrmemfunc_access_expr (pfn, pfn_identifier);
5699 delta = build_ptrmemfunc_access_expr (pfn, delta_identifier);
5702 /* Just adjust the DELTA field. */
5703 gcc_assert (same_type_ignoring_top_level_qualifiers_p
5704 (TREE_TYPE (delta), ptrdiff_type_node));
5705 if (TARGET_PTRMEMFUNC_VBIT_LOCATION == ptrmemfunc_vbit_in_delta)
5706 n = cp_build_binary_op (LSHIFT_EXPR, n, integer_one_node);
5707 delta = cp_build_binary_op (PLUS_EXPR, delta, n);
5708 return build_ptrmemfunc1 (to_type, delta, npfn);
5711 /* Handle null pointer to member function conversions. */
5712 if (integer_zerop (pfn))
5714 pfn = build_c_cast (type, integer_zero_node);
5715 return build_ptrmemfunc1 (to_type,
5720 if (type_unknown_p (pfn))
5721 return instantiate_type (type, pfn, tf_error | tf_warning);
5723 fn = TREE_OPERAND (pfn, 0);
5724 gcc_assert (TREE_CODE (fn) == FUNCTION_DECL);
5725 return make_ptrmem_cst (to_type, fn);
5728 /* Return the DELTA, IDX, PFN, and DELTA2 values for the PTRMEM_CST
5731 ??? There is no consistency as to the types returned for the above
5732 values. Some code acts as if it were a sizetype and some as if it were
5733 integer_type_node. */
5736 expand_ptrmemfunc_cst (tree cst, tree *delta, tree *pfn)
5738 tree type = TREE_TYPE (cst);
5739 tree fn = PTRMEM_CST_MEMBER (cst);
5740 tree ptr_class, fn_class;
5742 gcc_assert (TREE_CODE (fn) == FUNCTION_DECL);
5744 /* The class that the function belongs to. */
5745 fn_class = DECL_CONTEXT (fn);
5747 /* The class that we're creating a pointer to member of. */
5748 ptr_class = TYPE_PTRMEMFUNC_OBJECT_TYPE (type);
5750 /* First, calculate the adjustment to the function's class. */
5751 *delta = get_delta_difference (fn_class, ptr_class, /*force=*/0,
5754 if (!DECL_VIRTUAL_P (fn))
5755 *pfn = convert (TYPE_PTRMEMFUNC_FN_TYPE (type), build_addr_func (fn));
5758 /* If we're dealing with a virtual function, we have to adjust 'this'
5759 again, to point to the base which provides the vtable entry for
5760 fn; the call will do the opposite adjustment. */
5761 tree orig_class = DECL_CONTEXT (fn);
5762 tree binfo = binfo_or_else (orig_class, fn_class);
5763 *delta = build2 (PLUS_EXPR, TREE_TYPE (*delta),
5764 *delta, BINFO_OFFSET (binfo));
5765 *delta = fold_if_not_in_template (*delta);
5767 /* We set PFN to the vtable offset at which the function can be
5768 found, plus one (unless ptrmemfunc_vbit_in_delta, in which
5769 case delta is shifted left, and then incremented). */
5770 *pfn = DECL_VINDEX (fn);
5771 *pfn = build2 (MULT_EXPR, integer_type_node, *pfn,
5772 TYPE_SIZE_UNIT (vtable_entry_type));
5773 *pfn = fold_if_not_in_template (*pfn);
5775 switch (TARGET_PTRMEMFUNC_VBIT_LOCATION)
5777 case ptrmemfunc_vbit_in_pfn:
5778 *pfn = build2 (PLUS_EXPR, integer_type_node, *pfn,
5780 *pfn = fold_if_not_in_template (*pfn);
5783 case ptrmemfunc_vbit_in_delta:
5784 *delta = build2 (LSHIFT_EXPR, TREE_TYPE (*delta),
5785 *delta, integer_one_node);
5786 *delta = fold_if_not_in_template (*delta);
5787 *delta = build2 (PLUS_EXPR, TREE_TYPE (*delta),
5788 *delta, integer_one_node);
5789 *delta = fold_if_not_in_template (*delta);
5796 *pfn = build_nop (TYPE_PTRMEMFUNC_FN_TYPE (type), *pfn);
5797 *pfn = fold_if_not_in_template (*pfn);
5801 /* Return an expression for PFN from the pointer-to-member function
5805 pfn_from_ptrmemfunc (tree t)
5807 if (TREE_CODE (t) == PTRMEM_CST)
5812 expand_ptrmemfunc_cst (t, &delta, &pfn);
5817 return build_ptrmemfunc_access_expr (t, pfn_identifier);
5820 /* Expression EXPR is about to be implicitly converted to TYPE. Warn
5821 if this is a potentially dangerous thing to do. Returns a possibly
5825 dubious_conversion_warnings (tree type, tree expr,
5826 const char *errtype, tree fndecl, int parmnum)
5828 type = non_reference (type);
5830 /* Issue warnings about peculiar, but valid, uses of NULL. */
5831 if (ARITHMETIC_TYPE_P (type) && expr == null_node)
5834 warning ("passing NULL used for non-pointer %s %P of %qD",
5835 errtype, parmnum, fndecl);
5837 warning ("%s to non-pointer type %qT from NULL", errtype, type);
5840 /* Warn about assigning a floating-point type to an integer type. */
5841 if (TREE_CODE (TREE_TYPE (expr)) == REAL_TYPE
5842 && TREE_CODE (type) == INTEGER_TYPE)
5845 warning ("passing %qT for %s %P of %qD",
5846 TREE_TYPE (expr), errtype, parmnum, fndecl);
5848 warning ("%s to %qT from %qT", errtype, type, TREE_TYPE (expr));
5850 /* And warn about assigning a negative value to an unsigned
5852 else if (TYPE_UNSIGNED (type) && TREE_CODE (type) != BOOLEAN_TYPE)
5854 if (TREE_CODE (expr) == INTEGER_CST && TREE_NEGATED_INT (expr))
5857 warning ("passing negative value %qE for %s %P of %qD",
5858 expr, errtype, parmnum, fndecl);
5860 warning ("%s of negative value %qE to %qT", errtype, expr, type);
5863 overflow_warning (expr);
5865 if (TREE_CONSTANT (expr))
5866 expr = fold_if_not_in_template (expr);
5871 /* Convert value RHS to type TYPE as preparation for an assignment to
5872 an lvalue of type TYPE. ERRTYPE is a string to use in error
5873 messages: "assignment", "return", etc. If FNDECL is non-NULL, we
5874 are doing the conversion in order to pass the PARMNUMth argument of
5878 convert_for_assignment (tree type, tree rhs,
5879 const char *errtype, tree fndecl, int parmnum)
5882 enum tree_code coder;
5884 /* Strip NON_LVALUE_EXPRs since we aren't using as an lvalue. */
5885 if (TREE_CODE (rhs) == NON_LVALUE_EXPR)
5886 rhs = TREE_OPERAND (rhs, 0);
5888 rhstype = TREE_TYPE (rhs);
5889 coder = TREE_CODE (rhstype);
5891 if (TREE_CODE (type) == VECTOR_TYPE && coder == VECTOR_TYPE
5892 && vector_types_convertible_p (type, rhstype))
5893 return convert (type, rhs);
5895 if (rhs == error_mark_node || rhstype == error_mark_node)
5896 return error_mark_node;
5897 if (TREE_CODE (rhs) == TREE_LIST && TREE_VALUE (rhs) == error_mark_node)
5898 return error_mark_node;
5900 /* The RHS of an assignment cannot have void type. */
5901 if (coder == VOID_TYPE)
5903 error ("void value not ignored as it ought to be");
5904 return error_mark_node;
5907 /* Simplify the RHS if possible. */
5908 if (TREE_CODE (rhs) == CONST_DECL)
5909 rhs = DECL_INITIAL (rhs);
5913 The expression is implicitly converted (clause _conv_) to the
5914 cv-unqualified type of the left operand.
5916 We allow bad conversions here because by the time we get to this point
5917 we are committed to doing the conversion. If we end up doing a bad
5918 conversion, convert_like will complain. */
5919 if (!can_convert_arg_bad (type, rhstype, rhs))
5921 /* When -Wno-pmf-conversions is use, we just silently allow
5922 conversions from pointers-to-members to plain pointers. If
5923 the conversion doesn't work, cp_convert will complain. */
5925 && TYPE_PTR_P (type)
5926 && TYPE_PTRMEMFUNC_P (rhstype))
5927 rhs = cp_convert (strip_top_quals (type), rhs);
5930 /* If the right-hand side has unknown type, then it is an
5931 overloaded function. Call instantiate_type to get error
5933 if (rhstype == unknown_type_node)
5934 instantiate_type (type, rhs, tf_error | tf_warning);
5936 error ("cannot convert %qT to %qT for argument %qP to %qD",
5937 rhstype, type, parmnum, fndecl);
5939 error ("cannot convert %qT to %qT in %s", rhstype, type, errtype);
5940 return error_mark_node;
5943 return perform_implicit_conversion (strip_top_quals (type), rhs);
5946 /* Convert RHS to be of type TYPE.
5947 If EXP is nonzero, it is the target of the initialization.
5948 ERRTYPE is a string to use in error messages.
5950 Two major differences between the behavior of
5951 `convert_for_assignment' and `convert_for_initialization'
5952 are that references are bashed in the former, while
5953 copied in the latter, and aggregates are assigned in
5954 the former (operator=) while initialized in the
5957 If using constructor make sure no conversion operator exists, if one does
5958 exist, an ambiguity exists.
5960 If flags doesn't include LOOKUP_COMPLAIN, don't complain about anything. */
5963 convert_for_initialization (tree exp, tree type, tree rhs, int flags,
5964 const char *errtype, tree fndecl, int parmnum)
5966 enum tree_code codel = TREE_CODE (type);
5968 enum tree_code coder;
5970 /* build_c_cast puts on a NOP_EXPR to make the result not an lvalue.
5971 Strip such NOP_EXPRs, since RHS is used in non-lvalue context. */
5972 if (TREE_CODE (rhs) == NOP_EXPR
5973 && TREE_TYPE (rhs) == TREE_TYPE (TREE_OPERAND (rhs, 0))
5974 && codel != REFERENCE_TYPE)
5975 rhs = TREE_OPERAND (rhs, 0);
5977 if (rhs == error_mark_node
5978 || (TREE_CODE (rhs) == TREE_LIST && TREE_VALUE (rhs) == error_mark_node))
5979 return error_mark_node;
5981 if ((TREE_CODE (TREE_TYPE (rhs)) == ARRAY_TYPE
5982 && TREE_CODE (type) != ARRAY_TYPE
5983 && (TREE_CODE (type) != REFERENCE_TYPE
5984 || TREE_CODE (TREE_TYPE (type)) != ARRAY_TYPE))
5985 || (TREE_CODE (TREE_TYPE (rhs)) == FUNCTION_TYPE
5986 && (TREE_CODE (type) != REFERENCE_TYPE
5987 || TREE_CODE (TREE_TYPE (type)) != FUNCTION_TYPE))
5988 || TREE_CODE (TREE_TYPE (rhs)) == METHOD_TYPE)
5989 rhs = decay_conversion (rhs);
5991 rhstype = TREE_TYPE (rhs);
5992 coder = TREE_CODE (rhstype);
5994 if (coder == ERROR_MARK)
5995 return error_mark_node;
5997 /* We accept references to incomplete types, so we can
5998 return here before checking if RHS is of complete type. */
6000 if (codel == REFERENCE_TYPE)
6002 /* This should eventually happen in convert_arguments. */
6003 int savew = 0, savee = 0;
6006 savew = warningcount, savee = errorcount;
6007 rhs = initialize_reference (type, rhs, /*decl=*/NULL_TREE,
6011 if (warningcount > savew)
6012 cp_warning_at ("in passing argument %P of %q+D", parmnum, fndecl);
6013 else if (errorcount > savee)
6014 cp_error_at ("in passing argument %P of %q+D", parmnum, fndecl);
6020 exp = require_complete_type (exp);
6021 if (exp == error_mark_node)
6022 return error_mark_node;
6024 rhstype = non_reference (rhstype);
6026 type = complete_type (type);
6028 if (IS_AGGR_TYPE (type))
6029 return ocp_convert (type, rhs, CONV_IMPLICIT|CONV_FORCE_TEMP, flags);
6031 return convert_for_assignment (type, rhs, errtype, fndecl, parmnum);
6034 /* If RETVAL is the address of, or a reference to, a local variable or
6035 temporary give an appropriate warning. */
6038 maybe_warn_about_returning_address_of_local (tree retval)
6040 tree valtype = TREE_TYPE (DECL_RESULT (current_function_decl));
6041 tree whats_returned = retval;
6045 if (TREE_CODE (whats_returned) == COMPOUND_EXPR)
6046 whats_returned = TREE_OPERAND (whats_returned, 1);
6047 else if (TREE_CODE (whats_returned) == CONVERT_EXPR
6048 || TREE_CODE (whats_returned) == NON_LVALUE_EXPR
6049 || TREE_CODE (whats_returned) == NOP_EXPR)
6050 whats_returned = TREE_OPERAND (whats_returned, 0);
6055 if (TREE_CODE (whats_returned) != ADDR_EXPR)
6057 whats_returned = TREE_OPERAND (whats_returned, 0);
6059 if (TREE_CODE (valtype) == REFERENCE_TYPE)
6061 if (TREE_CODE (whats_returned) == AGGR_INIT_EXPR
6062 || TREE_CODE (whats_returned) == TARGET_EXPR)
6064 warning ("returning reference to temporary");
6067 if (TREE_CODE (whats_returned) == VAR_DECL
6068 && DECL_NAME (whats_returned)
6069 && TEMP_NAME_P (DECL_NAME (whats_returned)))
6071 warning ("reference to non-lvalue returned");
6076 if (DECL_P (whats_returned)
6077 && DECL_NAME (whats_returned)
6078 && DECL_FUNCTION_SCOPE_P (whats_returned)
6079 && !(TREE_STATIC (whats_returned)
6080 || TREE_PUBLIC (whats_returned)))
6082 if (TREE_CODE (valtype) == REFERENCE_TYPE)
6083 cp_warning_at ("reference to local variable %qD returned",
6086 cp_warning_at ("address of local variable %qD returned",
6092 /* Check that returning RETVAL from the current function is valid.
6093 Return an expression explicitly showing all conversions required to
6094 change RETVAL into the function return type, and to assign it to
6095 the DECL_RESULT for the function. */
6098 check_return_expr (tree retval)
6101 /* The type actually returned by the function, after any
6104 int fn_returns_value_p;
6106 /* A `volatile' function is one that isn't supposed to return, ever.
6107 (This is a G++ extension, used to get better code for functions
6108 that call the `volatile' function.) */
6109 if (TREE_THIS_VOLATILE (current_function_decl))
6110 warning ("function declared %<noreturn%> has a %<return%> statement");
6112 /* Check for various simple errors. */
6113 if (DECL_DESTRUCTOR_P (current_function_decl))
6116 error ("returning a value from a destructor");
6119 else if (DECL_CONSTRUCTOR_P (current_function_decl))
6121 if (in_function_try_handler)
6122 /* If a return statement appears in a handler of the
6123 function-try-block of a constructor, the program is ill-formed. */
6124 error ("cannot return from a handler of a function-try-block of a constructor");
6126 /* You can't return a value from a constructor. */
6127 error ("returning a value from a constructor");
6131 if (processing_template_decl)
6133 current_function_returns_value = 1;
6137 /* When no explicit return-value is given in a function with a named
6138 return value, the named return value is used. */
6139 result = DECL_RESULT (current_function_decl);
6140 valtype = TREE_TYPE (result);
6141 gcc_assert (valtype != NULL_TREE);
6142 fn_returns_value_p = !VOID_TYPE_P (valtype);
6143 if (!retval && DECL_NAME (result) && fn_returns_value_p)
6146 /* Check for a return statement with no return value in a function
6147 that's supposed to return a value. */
6148 if (!retval && fn_returns_value_p)
6150 pedwarn ("return-statement with no value, in function returning %qT",
6152 /* Clear this, so finish_function won't say that we reach the
6153 end of a non-void function (which we don't, we gave a
6155 current_function_returns_null = 0;
6157 /* Check for a return statement with a value in a function that
6158 isn't supposed to return a value. */
6159 else if (retval && !fn_returns_value_p)
6161 if (VOID_TYPE_P (TREE_TYPE (retval)))
6162 /* You can return a `void' value from a function of `void'
6163 type. In that case, we have to evaluate the expression for
6164 its side-effects. */
6165 finish_expr_stmt (retval);
6167 pedwarn ("return-statement with a value, in function "
6168 "returning 'void'");
6170 current_function_returns_null = 1;
6172 /* There's really no value to return, after all. */
6176 /* Remember that this function can sometimes return without a
6178 current_function_returns_null = 1;
6180 /* Remember that this function did return a value. */
6181 current_function_returns_value = 1;
6183 /* Check for erroneous operands -- but after giving ourselves a
6184 chance to provide an error about returning a value from a void
6186 if (error_operand_p (retval))
6188 current_function_return_value = error_mark_node;
6189 return error_mark_node;
6192 /* Only operator new(...) throw(), can return NULL [expr.new/13]. */
6193 if ((DECL_OVERLOADED_OPERATOR_P (current_function_decl) == NEW_EXPR
6194 || DECL_OVERLOADED_OPERATOR_P (current_function_decl) == VEC_NEW_EXPR)
6195 && !TYPE_NOTHROW_P (TREE_TYPE (current_function_decl))
6197 && null_ptr_cst_p (retval))
6198 warning ("%<operator new%> must not return NULL unless it is "
6199 "declared %<throw()%> (or -fcheck-new is in effect)");
6201 /* Effective C++ rule 15. See also start_function. */
6203 && DECL_NAME (current_function_decl) == ansi_assopname(NOP_EXPR))
6207 /* The function return type must be a reference to the current
6209 if (TREE_CODE (valtype) == REFERENCE_TYPE
6210 && same_type_ignoring_top_level_qualifiers_p
6211 (TREE_TYPE (valtype), TREE_TYPE (current_class_ref)))
6213 /* Returning '*this' is obviously OK. */
6214 if (retval == current_class_ref)
6216 /* If we are calling a function whose return type is the same of
6217 the current class reference, it is ok. */
6218 else if (TREE_CODE (retval) == INDIRECT_REF
6219 && TREE_CODE (TREE_OPERAND (retval, 0)) == CALL_EXPR)
6224 warning ("%<operator=%> should return a reference to %<*this%>");
6227 /* The fabled Named Return Value optimization, as per [class.copy]/15:
6229 [...] For a function with a class return type, if the expression
6230 in the return statement is the name of a local object, and the cv-
6231 unqualified type of the local object is the same as the function
6232 return type, an implementation is permitted to omit creating the tem-
6233 porary object to hold the function return value [...]
6235 So, if this is a value-returning function that always returns the same
6236 local variable, remember it.
6238 It might be nice to be more flexible, and choose the first suitable
6239 variable even if the function sometimes returns something else, but
6240 then we run the risk of clobbering the variable we chose if the other
6241 returned expression uses the chosen variable somehow. And people expect
6242 this restriction, anyway. (jason 2000-11-19)
6244 See finish_function and finalize_nrv for the rest of this optimization. */
6246 if (fn_returns_value_p && flag_elide_constructors)
6248 if (retval != NULL_TREE
6249 && (current_function_return_value == NULL_TREE
6250 || current_function_return_value == retval)
6251 && TREE_CODE (retval) == VAR_DECL
6252 && DECL_CONTEXT (retval) == current_function_decl
6253 && ! TREE_STATIC (retval)
6254 && (DECL_ALIGN (retval)
6255 >= DECL_ALIGN (DECL_RESULT (current_function_decl)))
6256 && same_type_p ((TYPE_MAIN_VARIANT
6257 (TREE_TYPE (retval))),
6259 (TREE_TYPE (TREE_TYPE (current_function_decl))))))
6260 current_function_return_value = retval;
6262 current_function_return_value = error_mark_node;
6265 /* We don't need to do any conversions when there's nothing being
6270 /* Do any required conversions. */
6271 if (retval == result || DECL_CONSTRUCTOR_P (current_function_decl))
6272 /* No conversions are required. */
6276 /* The type the function is declared to return. */
6277 tree functype = TREE_TYPE (TREE_TYPE (current_function_decl));
6279 /* First convert the value to the function's return type, then
6280 to the type of return value's location to handle the
6281 case that functype is smaller than the valtype. */
6282 retval = convert_for_initialization
6283 (NULL_TREE, functype, retval, LOOKUP_NORMAL|LOOKUP_ONLYCONVERTING,
6284 "return", NULL_TREE, 0);
6285 retval = convert (valtype, retval);
6287 /* If the conversion failed, treat this just like `return;'. */
6288 if (retval == error_mark_node)
6290 /* We can't initialize a register from a AGGR_INIT_EXPR. */
6291 else if (! current_function_returns_struct
6292 && TREE_CODE (retval) == TARGET_EXPR
6293 && TREE_CODE (TREE_OPERAND (retval, 1)) == AGGR_INIT_EXPR)
6294 retval = build2 (COMPOUND_EXPR, TREE_TYPE (retval), retval,
6295 TREE_OPERAND (retval, 0));
6297 maybe_warn_about_returning_address_of_local (retval);
6300 /* Actually copy the value returned into the appropriate location. */
6301 if (retval && retval != result)
6302 retval = build2 (INIT_EXPR, TREE_TYPE (result), result, retval);
6308 /* Returns nonzero if the pointer-type FROM can be converted to the
6309 pointer-type TO via a qualification conversion. If CONSTP is -1,
6310 then we return nonzero if the pointers are similar, and the
6311 cv-qualification signature of FROM is a proper subset of that of TO.
6313 If CONSTP is positive, then all outer pointers have been
6317 comp_ptr_ttypes_real (tree to, tree from, int constp)
6319 bool to_more_cv_qualified = false;
6321 for (; ; to = TREE_TYPE (to), from = TREE_TYPE (from))
6323 if (TREE_CODE (to) != TREE_CODE (from))
6326 if (TREE_CODE (from) == OFFSET_TYPE
6327 && !same_type_p (TYPE_OFFSET_BASETYPE (from),
6328 TYPE_OFFSET_BASETYPE (to)))
6331 /* Const and volatile mean something different for function types,
6332 so the usual checks are not appropriate. */
6333 if (TREE_CODE (to) != FUNCTION_TYPE && TREE_CODE (to) != METHOD_TYPE)
6335 if (!at_least_as_qualified_p (to, from))
6338 if (!at_least_as_qualified_p (from, to))
6342 to_more_cv_qualified = true;
6346 constp &= TYPE_READONLY (to);
6349 if (TREE_CODE (to) != POINTER_TYPE && !TYPE_PTRMEM_P (to))
6350 return ((constp >= 0 || to_more_cv_qualified)
6351 && same_type_ignoring_top_level_qualifiers_p (to, from));
6355 /* When comparing, say, char ** to char const **, this function takes
6356 the 'char *' and 'char const *'. Do not pass non-pointer/reference
6357 types to this function. */
6360 comp_ptr_ttypes (tree to, tree from)
6362 return comp_ptr_ttypes_real (to, from, 1);
6365 /* Returns 1 if to and from are (possibly multi-level) pointers to the same
6366 type or inheritance-related types, regardless of cv-quals. */
6369 ptr_reasonably_similar (tree to, tree from)
6371 for (; ; to = TREE_TYPE (to), from = TREE_TYPE (from))
6373 /* Any target type is similar enough to void. */
6374 if (TREE_CODE (to) == VOID_TYPE
6375 || TREE_CODE (from) == VOID_TYPE)
6378 if (TREE_CODE (to) != TREE_CODE (from))
6381 if (TREE_CODE (from) == OFFSET_TYPE
6382 && comptypes (TYPE_OFFSET_BASETYPE (to),
6383 TYPE_OFFSET_BASETYPE (from),
6384 COMPARE_BASE | COMPARE_DERIVED))
6387 if (TREE_CODE (to) == VECTOR_TYPE
6388 && vector_types_convertible_p (to, from))
6391 if (TREE_CODE (to) == INTEGER_TYPE
6392 && TYPE_PRECISION (to) == TYPE_PRECISION (from))
6395 if (TREE_CODE (to) == FUNCTION_TYPE)
6398 if (TREE_CODE (to) != POINTER_TYPE)
6400 (TYPE_MAIN_VARIANT (to), TYPE_MAIN_VARIANT (from),
6401 COMPARE_BASE | COMPARE_DERIVED);
6405 /* Like comp_ptr_ttypes, for const_cast. */
6408 comp_ptr_ttypes_const (tree to, tree from)
6410 for (; ; to = TREE_TYPE (to), from = TREE_TYPE (from))
6412 if (TREE_CODE (to) != TREE_CODE (from))
6415 if (TREE_CODE (from) == OFFSET_TYPE
6416 && same_type_p (TYPE_OFFSET_BASETYPE (from),
6417 TYPE_OFFSET_BASETYPE (to)))
6420 if (TREE_CODE (to) != POINTER_TYPE)
6421 return same_type_ignoring_top_level_qualifiers_p (to, from);
6425 /* Returns the type qualifiers for this type, including the qualifiers on the
6426 elements for an array type. */
6429 cp_type_quals (tree type)
6431 type = strip_array_types (type);
6432 if (type == error_mark_node)
6433 return TYPE_UNQUALIFIED;
6434 return TYPE_QUALS (type);
6437 /* Returns nonzero if the TYPE contains a mutable member. */
6440 cp_has_mutable_p (tree type)
6442 type = strip_array_types (type);
6444 return CLASS_TYPE_P (type) && CLASSTYPE_HAS_MUTABLE (type);
6447 /* Subroutine of casts_away_constness. Make T1 and T2 point at
6448 exemplar types such that casting T1 to T2 is casting away constness
6449 if and only if there is no implicit conversion from T1 to T2. */
6452 casts_away_constness_r (tree *t1, tree *t2)
6457 /* [expr.const.cast]
6459 For multi-level pointer to members and multi-level mixed pointers
6460 and pointers to members (conv.qual), the "member" aspect of a
6461 pointer to member level is ignored when determining if a const
6462 cv-qualifier has been cast away. */
6463 if (TYPE_PTRMEM_P (*t1))
6464 *t1 = build_pointer_type (TYPE_PTRMEM_POINTED_TO_TYPE (*t1));
6465 if (TYPE_PTRMEM_P (*t2))
6466 *t2 = build_pointer_type (TYPE_PTRMEM_POINTED_TO_TYPE (*t2));
6468 /* [expr.const.cast]
6470 For two pointer types:
6472 X1 is T1cv1,1 * ... cv1,N * where T1 is not a pointer type
6473 X2 is T2cv2,1 * ... cv2,M * where T2 is not a pointer type
6476 casting from X1 to X2 casts away constness if, for a non-pointer
6477 type T there does not exist an implicit conversion (clause
6480 Tcv1,(N-K+1) * cv1,(N-K+2) * ... cv1,N *
6484 Tcv2,(M-K+1) * cv2,(M-K+2) * ... cv2,M *. */
6486 if (TREE_CODE (*t1) != POINTER_TYPE
6487 || TREE_CODE (*t2) != POINTER_TYPE)
6489 *t1 = cp_build_qualified_type (void_type_node,
6490 cp_type_quals (*t1));
6491 *t2 = cp_build_qualified_type (void_type_node,
6492 cp_type_quals (*t2));
6496 quals1 = cp_type_quals (*t1);
6497 quals2 = cp_type_quals (*t2);
6498 *t1 = TREE_TYPE (*t1);
6499 *t2 = TREE_TYPE (*t2);
6500 casts_away_constness_r (t1, t2);
6501 *t1 = build_pointer_type (*t1);
6502 *t2 = build_pointer_type (*t2);
6503 *t1 = cp_build_qualified_type (*t1, quals1);
6504 *t2 = cp_build_qualified_type (*t2, quals2);
6507 /* Returns nonzero if casting from TYPE1 to TYPE2 casts away
6511 casts_away_constness (tree t1, tree t2)
6513 if (TREE_CODE (t2) == REFERENCE_TYPE)
6515 /* [expr.const.cast]
6517 Casting from an lvalue of type T1 to an lvalue of type T2
6518 using a reference cast casts away constness if a cast from an
6519 rvalue of type "pointer to T1" to the type "pointer to T2"
6520 casts away constness. */
6521 t1 = (TREE_CODE (t1) == REFERENCE_TYPE ? TREE_TYPE (t1) : t1);
6522 return casts_away_constness (build_pointer_type (t1),
6523 build_pointer_type (TREE_TYPE (t2)));
6526 if (TYPE_PTRMEM_P (t1) && TYPE_PTRMEM_P (t2))
6527 /* [expr.const.cast]
6529 Casting from an rvalue of type "pointer to data member of X
6530 of type T1" to the type "pointer to data member of Y of type
6531 T2" casts away constness if a cast from an rvalue of type
6532 "pointer to T1" to the type "pointer to T2" casts away
6534 return casts_away_constness
6535 (build_pointer_type (TYPE_PTRMEM_POINTED_TO_TYPE (t1)),
6536 build_pointer_type (TYPE_PTRMEM_POINTED_TO_TYPE (t2)));
6538 /* Casting away constness is only something that makes sense for
6539 pointer or reference types. */
6540 if (TREE_CODE (t1) != POINTER_TYPE
6541 || TREE_CODE (t2) != POINTER_TYPE)
6544 /* Top-level qualifiers don't matter. */
6545 t1 = TYPE_MAIN_VARIANT (t1);
6546 t2 = TYPE_MAIN_VARIANT (t2);
6547 casts_away_constness_r (&t1, &t2);
6548 if (!can_convert (t2, t1))
6554 /* If T is a REFERENCE_TYPE return the type to which T refers.
6555 Otherwise, return T itself. */
6558 non_reference (tree t)
6560 if (TREE_CODE (t) == REFERENCE_TYPE)