1 /* Build expressions with type checking for C++ compiler.
2 Copyright (C) 1987, 1988, 1989, 1992, 1993, 1994, 1995, 1996, 1997, 1998,
3 1999, 2000, 2001, 2002, 2003, 2004, 2005 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);
60 static tree convert_arguments (tree, tree, tree, int);
62 /* Do `exp = require_complete_type (exp);' to make sure exp
63 does not have an incomplete type. (That includes void types.)
64 Returns the error_mark_node if the VALUE does not have
65 complete type when this function returns. */
68 require_complete_type (tree value)
72 if (processing_template_decl || value == error_mark_node)
75 if (TREE_CODE (value) == OVERLOAD)
76 type = unknown_type_node;
78 type = TREE_TYPE (value);
80 if (type == error_mark_node)
81 return error_mark_node;
83 /* First, detect a valid value with a complete type. */
84 if (COMPLETE_TYPE_P (type))
87 if (complete_type_or_else (type, value))
90 return error_mark_node;
93 /* Try to complete TYPE, if it is incomplete. For example, if TYPE is
94 a template instantiation, do the instantiation. Returns TYPE,
95 whether or not it could be completed, unless something goes
96 horribly wrong, in which case the error_mark_node is returned. */
99 complete_type (tree type)
101 if (type == NULL_TREE)
102 /* Rather than crash, we return something sure to cause an error
104 return error_mark_node;
106 if (type == error_mark_node || COMPLETE_TYPE_P (type))
108 else if (TREE_CODE (type) == ARRAY_TYPE && TYPE_DOMAIN (type))
110 tree t = complete_type (TREE_TYPE (type));
111 if (COMPLETE_TYPE_P (t) && !dependent_type_p (type))
113 TYPE_NEEDS_CONSTRUCTING (type)
114 = TYPE_NEEDS_CONSTRUCTING (TYPE_MAIN_VARIANT (t));
115 TYPE_HAS_NONTRIVIAL_DESTRUCTOR (type)
116 = TYPE_HAS_NONTRIVIAL_DESTRUCTOR (TYPE_MAIN_VARIANT (t));
118 else if (CLASS_TYPE_P (type) && CLASSTYPE_TEMPLATE_INSTANTIATION (type))
119 instantiate_class_template (TYPE_MAIN_VARIANT (type));
124 /* Like complete_type, but issue an error if the TYPE cannot be completed.
125 VALUE is used for informative diagnostics.
126 Returns NULL_TREE if the type cannot be made complete. */
129 complete_type_or_else (tree type, tree value)
131 type = complete_type (type);
132 if (type == error_mark_node)
133 /* We already issued an error. */
135 else if (!COMPLETE_TYPE_P (type))
137 cxx_incomplete_type_diagnostic (value, type, 0);
144 /* Return truthvalue of whether type of EXP is instantiated. */
147 type_unknown_p (tree exp)
149 return (TREE_CODE (exp) == TREE_LIST
150 || TREE_TYPE (exp) == unknown_type_node);
154 /* Return the common type of two parameter lists.
155 We assume that comptypes has already been done and returned 1;
156 if that isn't so, this may crash.
158 As an optimization, free the space we allocate if the parameter
159 lists are already common. */
162 commonparms (tree p1, tree p2)
164 tree oldargs = p1, newargs, n;
168 len = list_length (p1);
169 newargs = tree_last (p1);
171 if (newargs == void_list_node)
180 newargs = tree_cons (NULL_TREE, NULL_TREE, newargs);
185 p1 = TREE_CHAIN (p1), p2 = TREE_CHAIN (p2), n = TREE_CHAIN (n), i++)
187 if (TREE_PURPOSE (p1) && !TREE_PURPOSE (p2))
189 TREE_PURPOSE (n) = TREE_PURPOSE (p1);
192 else if (! TREE_PURPOSE (p1))
194 if (TREE_PURPOSE (p2))
196 TREE_PURPOSE (n) = TREE_PURPOSE (p2);
202 if (1 != simple_cst_equal (TREE_PURPOSE (p1), TREE_PURPOSE (p2)))
204 TREE_PURPOSE (n) = TREE_PURPOSE (p2);
206 if (TREE_VALUE (p1) != TREE_VALUE (p2))
209 TREE_VALUE (n) = merge_types (TREE_VALUE (p1), TREE_VALUE (p2));
212 TREE_VALUE (n) = TREE_VALUE (p1);
220 /* Given a type, perhaps copied for a typedef,
221 find the "original" version of it. */
223 original_type (tree t)
225 while (TYPE_NAME (t) != NULL_TREE)
227 tree x = TYPE_NAME (t);
228 if (TREE_CODE (x) != TYPE_DECL)
230 x = DECL_ORIGINAL_TYPE (x);
238 /* T1 and T2 are arithmetic or enumeration types. Return the type
239 that will result from the "usual arithmetic conversions" on T1 and
240 T2 as described in [expr]. */
243 type_after_usual_arithmetic_conversions (tree t1, tree t2)
245 enum tree_code code1 = TREE_CODE (t1);
246 enum tree_code code2 = TREE_CODE (t2);
249 /* FIXME: Attributes. */
250 gcc_assert (ARITHMETIC_TYPE_P (t1)
251 || TREE_CODE (t1) == COMPLEX_TYPE
252 || TREE_CODE (t1) == VECTOR_TYPE
253 || TREE_CODE (t1) == ENUMERAL_TYPE);
254 gcc_assert (ARITHMETIC_TYPE_P (t2)
255 || TREE_CODE (t2) == COMPLEX_TYPE
256 || TREE_CODE (t1) == VECTOR_TYPE
257 || TREE_CODE (t2) == ENUMERAL_TYPE);
259 /* In what follows, we slightly generalize the rules given in [expr] so
260 as to deal with `long long' and `complex'. First, merge the
262 attributes = (*targetm.merge_type_attributes) (t1, t2);
264 /* If one type is complex, form the common type of the non-complex
265 components, then make that complex. Use T1 or T2 if it is the
267 if (code1 == COMPLEX_TYPE || code2 == COMPLEX_TYPE)
269 tree subtype1 = code1 == COMPLEX_TYPE ? TREE_TYPE (t1) : t1;
270 tree subtype2 = code2 == COMPLEX_TYPE ? TREE_TYPE (t2) : t2;
272 = type_after_usual_arithmetic_conversions (subtype1, subtype2);
274 if (code1 == COMPLEX_TYPE && TREE_TYPE (t1) == subtype)
275 return build_type_attribute_variant (t1, attributes);
276 else if (code2 == COMPLEX_TYPE && TREE_TYPE (t2) == subtype)
277 return build_type_attribute_variant (t2, attributes);
279 return build_type_attribute_variant (build_complex_type (subtype),
283 if (code1 == VECTOR_TYPE)
285 /* When we get here we should have two vectors of the same size.
286 Just prefer the unsigned one if present. */
287 if (TYPE_UNSIGNED (t1))
288 return build_type_attribute_variant (t1, attributes);
290 return build_type_attribute_variant (t2, attributes);
293 /* If only one is real, use it as the result. */
294 if (code1 == REAL_TYPE && code2 != REAL_TYPE)
295 return build_type_attribute_variant (t1, attributes);
296 if (code2 == REAL_TYPE && code1 != REAL_TYPE)
297 return build_type_attribute_variant (t2, attributes);
299 /* Perform the integral promotions. */
300 if (code1 != REAL_TYPE)
302 t1 = type_promotes_to (t1);
303 t2 = type_promotes_to (t2);
306 /* Both real or both integers; use the one with greater precision. */
307 if (TYPE_PRECISION (t1) > TYPE_PRECISION (t2))
308 return build_type_attribute_variant (t1, attributes);
309 else if (TYPE_PRECISION (t2) > TYPE_PRECISION (t1))
310 return build_type_attribute_variant (t2, attributes);
312 /* The types are the same; no need to do anything fancy. */
313 if (TYPE_MAIN_VARIANT (t1) == TYPE_MAIN_VARIANT (t2))
314 return build_type_attribute_variant (t1, attributes);
316 if (code1 != REAL_TYPE)
318 /* If one is a sizetype, use it so size_binop doesn't blow up. */
319 if (TYPE_IS_SIZETYPE (t1) > TYPE_IS_SIZETYPE (t2))
320 return build_type_attribute_variant (t1, attributes);
321 if (TYPE_IS_SIZETYPE (t2) > TYPE_IS_SIZETYPE (t1))
322 return build_type_attribute_variant (t2, attributes);
324 /* If one is unsigned long long, then convert the other to unsigned
326 if (same_type_p (TYPE_MAIN_VARIANT (t1), long_long_unsigned_type_node)
327 || same_type_p (TYPE_MAIN_VARIANT (t2), long_long_unsigned_type_node))
328 return build_type_attribute_variant (long_long_unsigned_type_node,
330 /* If one is a long long, and the other is an unsigned long, and
331 long long can represent all the values of an unsigned long, then
332 convert to a long long. Otherwise, convert to an unsigned long
333 long. Otherwise, if either operand is long long, convert the
336 Since we're here, we know the TYPE_PRECISION is the same;
337 therefore converting to long long cannot represent all the values
338 of an unsigned long, so we choose unsigned long long in that
340 if (same_type_p (TYPE_MAIN_VARIANT (t1), long_long_integer_type_node)
341 || same_type_p (TYPE_MAIN_VARIANT (t2), long_long_integer_type_node))
343 tree t = ((TYPE_UNSIGNED (t1) || TYPE_UNSIGNED (t2))
344 ? long_long_unsigned_type_node
345 : long_long_integer_type_node);
346 return build_type_attribute_variant (t, attributes);
349 /* Go through the same procedure, but for longs. */
350 if (same_type_p (TYPE_MAIN_VARIANT (t1), long_unsigned_type_node)
351 || same_type_p (TYPE_MAIN_VARIANT (t2), long_unsigned_type_node))
352 return build_type_attribute_variant (long_unsigned_type_node,
354 if (same_type_p (TYPE_MAIN_VARIANT (t1), long_integer_type_node)
355 || same_type_p (TYPE_MAIN_VARIANT (t2), long_integer_type_node))
357 tree t = ((TYPE_UNSIGNED (t1) || TYPE_UNSIGNED (t2))
358 ? long_unsigned_type_node : long_integer_type_node);
359 return build_type_attribute_variant (t, attributes);
361 /* Otherwise prefer the unsigned one. */
362 if (TYPE_UNSIGNED (t1))
363 return build_type_attribute_variant (t1, attributes);
365 return build_type_attribute_variant (t2, attributes);
369 if (same_type_p (TYPE_MAIN_VARIANT (t1), long_double_type_node)
370 || same_type_p (TYPE_MAIN_VARIANT (t2), long_double_type_node))
371 return build_type_attribute_variant (long_double_type_node,
373 if (same_type_p (TYPE_MAIN_VARIANT (t1), double_type_node)
374 || same_type_p (TYPE_MAIN_VARIANT (t2), double_type_node))
375 return build_type_attribute_variant (double_type_node,
377 if (same_type_p (TYPE_MAIN_VARIANT (t1), float_type_node)
378 || same_type_p (TYPE_MAIN_VARIANT (t2), float_type_node))
379 return build_type_attribute_variant (float_type_node,
382 /* Two floating-point types whose TYPE_MAIN_VARIANTs are none of
383 the standard C++ floating-point types. Logic earlier in this
384 function has already eliminated the possibility that
385 TYPE_PRECISION (t2) != TYPE_PRECISION (t1), so there's no
386 compelling reason to choose one or the other. */
387 return build_type_attribute_variant (t1, attributes);
391 /* Subroutine of composite_pointer_type to implement the recursive
392 case. See that function for documentation fo the parameters. */
395 composite_pointer_type_r (tree t1, tree t2, const char* location)
402 /* Determine the types pointed to by T1 and T2. */
403 if (TREE_CODE (t1) == POINTER_TYPE)
405 pointee1 = TREE_TYPE (t1);
406 pointee2 = TREE_TYPE (t2);
410 pointee1 = TYPE_PTRMEM_POINTED_TO_TYPE (t1);
411 pointee2 = TYPE_PTRMEM_POINTED_TO_TYPE (t2);
416 Otherwise, the composite pointer type is a pointer type
417 similar (_conv.qual_) to the type of one of the operands,
418 with a cv-qualification signature (_conv.qual_) that is the
419 union of the cv-qualification signatures of the operand
421 if (same_type_ignoring_top_level_qualifiers_p (pointee1, pointee2))
422 result_type = pointee1;
423 else if ((TREE_CODE (pointee1) == POINTER_TYPE
424 && TREE_CODE (pointee2) == POINTER_TYPE)
425 || (TYPE_PTR_TO_MEMBER_P (pointee1)
426 && TYPE_PTR_TO_MEMBER_P (pointee2)))
427 result_type = composite_pointer_type_r (pointee1, pointee2, location);
430 pedwarn ("%s between distinct pointer types %qT and %qT "
433 result_type = void_type_node;
435 result_type = cp_build_qualified_type (result_type,
436 (cp_type_quals (pointee1)
437 | cp_type_quals (pointee2)));
438 /* If the original types were pointers to members, so is the
440 if (TYPE_PTR_TO_MEMBER_P (t1))
442 if (!same_type_p (TYPE_PTRMEM_CLASS_TYPE (t1),
443 TYPE_PTRMEM_CLASS_TYPE (t2)))
444 pedwarn ("%s between distinct pointer types %qT and %qT "
447 result_type = build_ptrmem_type (TYPE_PTRMEM_CLASS_TYPE (t1),
451 result_type = build_pointer_type (result_type);
453 /* Merge the attributes. */
454 attributes = (*targetm.merge_type_attributes) (t1, t2);
455 return build_type_attribute_variant (result_type, attributes);
458 /* Return the composite pointer type (see [expr.rel]) for T1 and T2.
459 ARG1 and ARG2 are the values with those types. The LOCATION is a
460 string describing the current location, in case an error occurs.
462 This routine also implements the computation of a common type for
463 pointers-to-members as per [expr.eq]. */
466 composite_pointer_type (tree t1, tree t2, tree arg1, tree arg2,
467 const char* location)
474 If one operand is a null pointer constant, the composite pointer
475 type is the type of the other operand. */
476 if (null_ptr_cst_p (arg1))
478 if (null_ptr_cst_p (arg2))
485 If one of the operands has type "pointer to cv1 void*", then
486 the other has type "pointer to cv2T", and the composite pointer
487 type is "pointer to cv12 void", where cv12 is the union of cv1
490 If either type is a pointer to void, make sure it is T1. */
491 if (TREE_CODE (t2) == POINTER_TYPE && VOID_TYPE_P (TREE_TYPE (t2)))
499 /* Now, if T1 is a pointer to void, merge the qualifiers. */
500 if (TREE_CODE (t1) == POINTER_TYPE && VOID_TYPE_P (TREE_TYPE (t1)))
505 if (pedantic && TYPE_PTRFN_P (t2))
506 pedwarn ("ISO C++ forbids %s between pointer of type %<void *%> "
507 "and pointer-to-function", location);
509 = cp_build_qualified_type (void_type_node,
510 (cp_type_quals (TREE_TYPE (t1))
511 | cp_type_quals (TREE_TYPE (t2))));
512 result_type = build_pointer_type (result_type);
513 /* Merge the attributes. */
514 attributes = (*targetm.merge_type_attributes) (t1, t2);
515 return build_type_attribute_variant (result_type, attributes);
518 if (c_dialect_objc () && TREE_CODE (t1) == POINTER_TYPE
519 && TREE_CODE (t2) == POINTER_TYPE)
521 if (objc_compare_types (t1, t2, -3, NULL_TREE))
525 /* [expr.eq] permits the application of a pointer conversion to
526 bring the pointers to a common type. */
527 if (TREE_CODE (t1) == POINTER_TYPE && TREE_CODE (t2) == POINTER_TYPE
528 && CLASS_TYPE_P (TREE_TYPE (t1))
529 && CLASS_TYPE_P (TREE_TYPE (t2))
530 && !same_type_ignoring_top_level_qualifiers_p (TREE_TYPE (t1),
533 class1 = TREE_TYPE (t1);
534 class2 = TREE_TYPE (t2);
536 if (DERIVED_FROM_P (class1, class2))
537 t2 = (build_pointer_type
538 (cp_build_qualified_type (class1, TYPE_QUALS (class2))));
539 else if (DERIVED_FROM_P (class2, class1))
540 t1 = (build_pointer_type
541 (cp_build_qualified_type (class2, TYPE_QUALS (class1))));
544 error ("%s between distinct pointer types %qT and %qT "
545 "lacks a cast", location, t1, t2);
546 return error_mark_node;
549 /* [expr.eq] permits the application of a pointer-to-member
550 conversion to change the class type of one of the types. */
551 else if (TYPE_PTR_TO_MEMBER_P (t1)
552 && !same_type_p (TYPE_PTRMEM_CLASS_TYPE (t1),
553 TYPE_PTRMEM_CLASS_TYPE (t2)))
555 class1 = TYPE_PTRMEM_CLASS_TYPE (t1);
556 class2 = TYPE_PTRMEM_CLASS_TYPE (t2);
558 if (DERIVED_FROM_P (class1, class2))
559 t1 = build_ptrmem_type (class2, TYPE_PTRMEM_POINTED_TO_TYPE (t1));
560 else if (DERIVED_FROM_P (class2, class1))
561 t2 = build_ptrmem_type (class1, TYPE_PTRMEM_POINTED_TO_TYPE (t2));
564 error ("%s between distinct pointer-to-member types %qT and %qT "
565 "lacks a cast", location, t1, t2);
566 return error_mark_node;
570 return composite_pointer_type_r (t1, t2, location);
573 /* Return the merged type of two types.
574 We assume that comptypes has already been done and returned 1;
575 if that isn't so, this may crash.
577 This just combines attributes and default arguments; any other
578 differences would cause the two types to compare unalike. */
581 merge_types (tree t1, tree t2)
583 enum tree_code code1;
584 enum tree_code code2;
587 /* Save time if the two types are the same. */
590 if (original_type (t1) == original_type (t2))
593 /* If one type is nonsense, use the other. */
594 if (t1 == error_mark_node)
596 if (t2 == error_mark_node)
599 /* Merge the attributes. */
600 attributes = (*targetm.merge_type_attributes) (t1, t2);
602 if (TYPE_PTRMEMFUNC_P (t1))
603 t1 = TYPE_PTRMEMFUNC_FN_TYPE (t1);
604 if (TYPE_PTRMEMFUNC_P (t2))
605 t2 = TYPE_PTRMEMFUNC_FN_TYPE (t2);
607 code1 = TREE_CODE (t1);
608 code2 = TREE_CODE (t2);
614 /* For two pointers, do this recursively on the target type. */
616 tree target = merge_types (TREE_TYPE (t1), TREE_TYPE (t2));
617 int quals = cp_type_quals (t1);
619 if (code1 == POINTER_TYPE)
620 t1 = build_pointer_type (target);
622 t1 = build_reference_type (target);
623 t1 = build_type_attribute_variant (t1, attributes);
624 t1 = cp_build_qualified_type (t1, quals);
626 if (TREE_CODE (target) == METHOD_TYPE)
627 t1 = build_ptrmemfunc_type (t1);
636 quals = cp_type_quals (t1);
637 pointee = merge_types (TYPE_PTRMEM_POINTED_TO_TYPE (t1),
638 TYPE_PTRMEM_POINTED_TO_TYPE (t2));
639 t1 = build_ptrmem_type (TYPE_PTRMEM_CLASS_TYPE (t1),
641 t1 = cp_build_qualified_type (t1, quals);
647 tree elt = merge_types (TREE_TYPE (t1), TREE_TYPE (t2));
648 /* Save space: see if the result is identical to one of the args. */
649 if (elt == TREE_TYPE (t1) && TYPE_DOMAIN (t1))
650 return build_type_attribute_variant (t1, attributes);
651 if (elt == TREE_TYPE (t2) && TYPE_DOMAIN (t2))
652 return build_type_attribute_variant (t2, attributes);
653 /* Merge the element types, and have a size if either arg has one. */
654 t1 = build_cplus_array_type
655 (elt, TYPE_DOMAIN (TYPE_DOMAIN (t1) ? t1 : t2));
660 /* Function types: prefer the one that specified arg types.
661 If both do, merge the arg types. Also merge the return types. */
663 tree valtype = merge_types (TREE_TYPE (t1), TREE_TYPE (t2));
664 tree p1 = TYPE_ARG_TYPES (t1);
665 tree p2 = TYPE_ARG_TYPES (t2);
668 /* Save space: see if the result is identical to one of the args. */
669 if (valtype == TREE_TYPE (t1) && ! p2)
670 return cp_build_type_attribute_variant (t1, attributes);
671 if (valtype == TREE_TYPE (t2) && ! p1)
672 return cp_build_type_attribute_variant (t2, attributes);
674 /* Simple way if one arg fails to specify argument types. */
675 if (p1 == NULL_TREE || TREE_VALUE (p1) == void_type_node)
677 rval = build_function_type (valtype, p2);
678 if ((raises = TYPE_RAISES_EXCEPTIONS (t2)))
679 rval = build_exception_variant (rval, raises);
680 return cp_build_type_attribute_variant (rval, attributes);
682 raises = TYPE_RAISES_EXCEPTIONS (t1);
683 if (p2 == NULL_TREE || TREE_VALUE (p2) == void_type_node)
685 rval = build_function_type (valtype, p1);
687 rval = build_exception_variant (rval, raises);
688 return cp_build_type_attribute_variant (rval, attributes);
691 rval = build_function_type (valtype, commonparms (p1, p2));
692 t1 = build_exception_variant (rval, raises);
698 /* Get this value the long way, since TYPE_METHOD_BASETYPE
699 is just the main variant of this. */
700 tree basetype = TREE_TYPE (TREE_VALUE (TYPE_ARG_TYPES (t2)));
701 tree raises = TYPE_RAISES_EXCEPTIONS (t1);
704 /* If this was a member function type, get back to the
705 original type of type member function (i.e., without
706 the class instance variable up front. */
707 t1 = build_function_type (TREE_TYPE (t1),
708 TREE_CHAIN (TYPE_ARG_TYPES (t1)));
709 t2 = build_function_type (TREE_TYPE (t2),
710 TREE_CHAIN (TYPE_ARG_TYPES (t2)));
711 t3 = merge_types (t1, t2);
712 t3 = build_method_type_directly (basetype, TREE_TYPE (t3),
713 TYPE_ARG_TYPES (t3));
714 t1 = build_exception_variant (t3, raises);
719 /* There is no need to merge attributes into a TYPENAME_TYPE.
720 When the type is instantiated it will have whatever
721 attributes result from the instantiation. */
726 return cp_build_type_attribute_variant (t1, attributes);
729 /* Return the common type of two types.
730 We assume that comptypes has already been done and returned 1;
731 if that isn't so, this may crash.
733 This is the type for the result of most arithmetic operations
734 if the operands have the given two types. */
737 common_type (tree t1, tree t2)
739 enum tree_code code1;
740 enum tree_code code2;
742 /* If one type is nonsense, bail. */
743 if (t1 == error_mark_node || t2 == error_mark_node)
744 return error_mark_node;
746 code1 = TREE_CODE (t1);
747 code2 = TREE_CODE (t2);
749 if ((ARITHMETIC_TYPE_P (t1) || code1 == ENUMERAL_TYPE
750 || code1 == COMPLEX_TYPE || code1 == VECTOR_TYPE)
751 && (ARITHMETIC_TYPE_P (t2) || code2 == ENUMERAL_TYPE
752 || code2 == COMPLEX_TYPE || code2 == VECTOR_TYPE))
753 return type_after_usual_arithmetic_conversions (t1, t2);
755 else if ((TYPE_PTR_P (t1) && TYPE_PTR_P (t2))
756 || (TYPE_PTRMEM_P (t1) && TYPE_PTRMEM_P (t2))
757 || (TYPE_PTRMEMFUNC_P (t1) && TYPE_PTRMEMFUNC_P (t2)))
758 return composite_pointer_type (t1, t2, error_mark_node, error_mark_node,
764 /* Compare two exception specifier types for exactness or subsetness, if
765 allowed. Returns false for mismatch, true for match (same, or
768 [except.spec] "If a class X ... objects of class X or any class publicly
769 and unambiguously derived from X. Similarly, if a pointer type Y * ...
770 exceptions of type Y * or that are pointers to any type publicly and
771 unambiguously derived from Y. Otherwise a function only allows exceptions
772 that have the same type ..."
773 This does not mention cv qualifiers and is different to what throw
774 [except.throw] and catch [except.catch] will do. They will ignore the
775 top level cv qualifiers, and allow qualifiers in the pointer to class
778 We implement the letter of the standard. */
781 comp_except_types (tree a, tree b, bool exact)
783 if (same_type_p (a, b))
787 if (cp_type_quals (a) || cp_type_quals (b))
790 if (TREE_CODE (a) == POINTER_TYPE
791 && TREE_CODE (b) == POINTER_TYPE)
795 if (cp_type_quals (a) || cp_type_quals (b))
799 if (TREE_CODE (a) != RECORD_TYPE
800 || TREE_CODE (b) != RECORD_TYPE)
803 if (PUBLICLY_UNIQUELY_DERIVED_P (a, b))
809 /* Return true if TYPE1 and TYPE2 are equivalent exception specifiers.
810 If EXACT is false, T2 can be stricter than T1 (according to 15.4/7),
811 otherwise it must be exact. Exception lists are unordered, but
812 we've already filtered out duplicates. Most lists will be in order,
813 we should try to make use of that. */
816 comp_except_specs (tree t1, tree t2, bool exact)
825 if (t1 == NULL_TREE) /* T1 is ... */
826 return t2 == NULL_TREE || !exact;
827 if (!TREE_VALUE (t1)) /* t1 is EMPTY */
828 return t2 != NULL_TREE && !TREE_VALUE (t2);
829 if (t2 == NULL_TREE) /* T2 is ... */
831 if (TREE_VALUE (t1) && !TREE_VALUE (t2)) /* T2 is EMPTY, T1 is not */
834 /* Neither set is ... or EMPTY, make sure each part of T2 is in T1.
835 Count how many we find, to determine exactness. For exact matching and
836 ordered T1, T2, this is an O(n) operation, otherwise its worst case is
838 for (base = t1; t2 != NULL_TREE; t2 = TREE_CHAIN (t2))
840 for (probe = base; probe != NULL_TREE; probe = TREE_CHAIN (probe))
842 tree a = TREE_VALUE (probe);
843 tree b = TREE_VALUE (t2);
845 if (comp_except_types (a, b, exact))
847 if (probe == base && exact)
848 base = TREE_CHAIN (probe);
853 if (probe == NULL_TREE)
856 return !exact || base == NULL_TREE || length == list_length (t1);
859 /* Compare the array types T1 and T2. ALLOW_REDECLARATION is true if
860 [] can match [size]. */
863 comp_array_types (tree t1, tree t2, bool allow_redeclaration)
872 /* The type of the array elements must be the same. */
873 if (!same_type_p (TREE_TYPE (t1), TREE_TYPE (t2)))
876 d1 = TYPE_DOMAIN (t1);
877 d2 = TYPE_DOMAIN (t2);
882 /* If one of the arrays is dimensionless, and the other has a
883 dimension, they are of different types. However, it is valid to
891 declarations for an array object can specify
892 array types that differ by the presence or absence of a major
893 array bound (_dcl.array_). */
895 return allow_redeclaration;
897 /* Check that the dimensions are the same. */
899 if (!cp_tree_equal (TYPE_MIN_VALUE (d1), TYPE_MIN_VALUE (d2)))
901 max1 = TYPE_MAX_VALUE (d1);
902 max2 = TYPE_MAX_VALUE (d2);
903 if (processing_template_decl && !abi_version_at_least (2)
904 && !value_dependent_expression_p (max1)
905 && !value_dependent_expression_p (max2))
907 /* With abi-1 we do not fold non-dependent array bounds, (and
908 consequently mangle them incorrectly). We must therefore
909 fold them here, to verify the domains have the same
915 if (!cp_tree_equal (max1, max2))
921 /* Return true if T1 and T2 are related as allowed by STRICT. STRICT
922 is a bitwise-or of the COMPARE_* flags. */
925 comptypes (tree t1, tree t2, int strict)
930 /* Suppress errors caused by previously reported errors. */
931 if (t1 == error_mark_node || t2 == error_mark_node)
934 gcc_assert (TYPE_P (t1) && TYPE_P (t2));
936 /* TYPENAME_TYPEs should be resolved if the qualifying scope is the
937 current instantiation. */
938 if (TREE_CODE (t1) == TYPENAME_TYPE)
940 tree resolved = resolve_typename_type (t1, /*only_current_p=*/true);
942 if (resolved != error_mark_node)
946 if (TREE_CODE (t2) == TYPENAME_TYPE)
948 tree resolved = resolve_typename_type (t2, /*only_current_p=*/true);
950 if (resolved != error_mark_node)
954 /* If either type is the internal version of sizetype, use the
956 if (TREE_CODE (t1) == INTEGER_TYPE && TYPE_IS_SIZETYPE (t1)
957 && TYPE_ORIG_SIZE_TYPE (t1))
958 t1 = TYPE_ORIG_SIZE_TYPE (t1);
960 if (TREE_CODE (t2) == INTEGER_TYPE && TYPE_IS_SIZETYPE (t2)
961 && TYPE_ORIG_SIZE_TYPE (t2))
962 t2 = TYPE_ORIG_SIZE_TYPE (t2);
964 if (TYPE_PTRMEMFUNC_P (t1))
965 t1 = TYPE_PTRMEMFUNC_FN_TYPE (t1);
966 if (TYPE_PTRMEMFUNC_P (t2))
967 t2 = TYPE_PTRMEMFUNC_FN_TYPE (t2);
969 /* Different classes of types can't be compatible. */
970 if (TREE_CODE (t1) != TREE_CODE (t2))
973 /* Qualifiers must match. For array types, we will check when we
974 recur on the array element types. */
975 if (TREE_CODE (t1) != ARRAY_TYPE
976 && TYPE_QUALS (t1) != TYPE_QUALS (t2))
978 if (TYPE_FOR_JAVA (t1) != TYPE_FOR_JAVA (t2))
981 /* Allow for two different type nodes which have essentially the same
982 definition. Note that we already checked for equality of the type
983 qualifiers (just above). */
985 if (TREE_CODE (t1) != ARRAY_TYPE
986 && TYPE_MAIN_VARIANT (t1) == TYPE_MAIN_VARIANT (t2))
989 /* Compare the types. Break out if they could be the same. */
990 switch (TREE_CODE (t1))
992 case TEMPLATE_TEMPLATE_PARM:
993 case BOUND_TEMPLATE_TEMPLATE_PARM:
994 if (TEMPLATE_TYPE_IDX (t1) != TEMPLATE_TYPE_IDX (t2)
995 || TEMPLATE_TYPE_LEVEL (t1) != TEMPLATE_TYPE_LEVEL (t2))
997 if (!comp_template_parms
998 (DECL_TEMPLATE_PARMS (TEMPLATE_TEMPLATE_PARM_TEMPLATE_DECL (t1)),
999 DECL_TEMPLATE_PARMS (TEMPLATE_TEMPLATE_PARM_TEMPLATE_DECL (t2))))
1001 if (TREE_CODE (t1) == TEMPLATE_TEMPLATE_PARM)
1003 /* Don't check inheritance. */
1004 strict = COMPARE_STRICT;
1009 if (TYPE_TEMPLATE_INFO (t1) && TYPE_TEMPLATE_INFO (t2)
1010 && (TYPE_TI_TEMPLATE (t1) == TYPE_TI_TEMPLATE (t2)
1011 || TREE_CODE (t1) == BOUND_TEMPLATE_TEMPLATE_PARM)
1012 && comp_template_args (TYPE_TI_ARGS (t1), TYPE_TI_ARGS (t2)))
1015 if ((strict & COMPARE_BASE) && DERIVED_FROM_P (t1, t2))
1017 else if ((strict & COMPARE_DERIVED) && DERIVED_FROM_P (t2, t1))
1023 if (!comptypes (TYPE_OFFSET_BASETYPE (t1), TYPE_OFFSET_BASETYPE (t2),
1024 strict & ~COMPARE_REDECLARATION))
1026 if (!same_type_p (TREE_TYPE (t1), TREE_TYPE (t2)))
1031 case REFERENCE_TYPE:
1032 if (TYPE_MODE (t1) != TYPE_MODE (t2)
1033 || TYPE_REF_CAN_ALIAS_ALL (t1) != TYPE_REF_CAN_ALIAS_ALL (t2)
1034 || !same_type_p (TREE_TYPE (t1), TREE_TYPE (t2)))
1040 if (!same_type_p (TREE_TYPE (t1), TREE_TYPE (t2)))
1042 if (!compparms (TYPE_ARG_TYPES (t1), TYPE_ARG_TYPES (t2)))
1047 /* Target types must match incl. qualifiers. */
1048 if (!comp_array_types (t1, t2, !!(strict & COMPARE_REDECLARATION)))
1052 case TEMPLATE_TYPE_PARM:
1053 if (TEMPLATE_TYPE_IDX (t1) != TEMPLATE_TYPE_IDX (t2)
1054 || TEMPLATE_TYPE_LEVEL (t1) != TEMPLATE_TYPE_LEVEL (t2))
1059 if (!cp_tree_equal (TYPENAME_TYPE_FULLNAME (t1),
1060 TYPENAME_TYPE_FULLNAME (t2)))
1062 if (!same_type_p (TYPE_CONTEXT (t1), TYPE_CONTEXT (t2)))
1066 case UNBOUND_CLASS_TEMPLATE:
1067 if (!cp_tree_equal (TYPE_IDENTIFIER (t1), TYPE_IDENTIFIER (t2)))
1069 if (!same_type_p (TYPE_CONTEXT (t1), TYPE_CONTEXT (t2)))
1074 if (!same_type_p (TREE_TYPE (t1), TREE_TYPE (t2)))
1079 if (TYPE_VECTOR_SUBPARTS (t1) != TYPE_VECTOR_SUBPARTS (t2)
1080 || !same_type_p (TREE_TYPE (t1), TREE_TYPE (t2)))
1088 /* If we get here, we know that from a target independent POV the
1089 types are the same. Make sure the target attributes are also
1091 return targetm.comp_type_attributes (t1, t2);
1094 /* Returns 1 if TYPE1 is at least as qualified as TYPE2. */
1097 at_least_as_qualified_p (tree type1, tree type2)
1099 int q1 = cp_type_quals (type1);
1100 int q2 = cp_type_quals (type2);
1102 /* All qualifiers for TYPE2 must also appear in TYPE1. */
1103 return (q1 & q2) == q2;
1106 /* Returns 1 if TYPE1 is more cv-qualified than TYPE2, -1 if TYPE2 is
1107 more cv-qualified that TYPE1, and 0 otherwise. */
1110 comp_cv_qualification (tree type1, tree type2)
1112 int q1 = cp_type_quals (type1);
1113 int q2 = cp_type_quals (type2);
1118 if ((q1 & q2) == q2)
1120 else if ((q1 & q2) == q1)
1126 /* Returns 1 if the cv-qualification signature of TYPE1 is a proper
1127 subset of the cv-qualification signature of TYPE2, and the types
1128 are similar. Returns -1 if the other way 'round, and 0 otherwise. */
1131 comp_cv_qual_signature (tree type1, tree type2)
1133 if (comp_ptr_ttypes_real (type2, type1, -1))
1135 else if (comp_ptr_ttypes_real (type1, type2, -1))
1141 /* If two types share a common base type, return that basetype.
1142 If there is not a unique most-derived base type, this function
1143 returns ERROR_MARK_NODE. */
1146 common_base_type (tree tt1, tree tt2)
1148 tree best = NULL_TREE;
1151 /* If one is a baseclass of another, that's good enough. */
1152 if (UNIQUELY_DERIVED_FROM_P (tt1, tt2))
1154 if (UNIQUELY_DERIVED_FROM_P (tt2, tt1))
1157 /* Otherwise, try to find a unique baseclass of TT1
1158 that is shared by TT2, and follow that down. */
1159 for (i = BINFO_N_BASE_BINFOS (TYPE_BINFO (tt1))-1; i >= 0; i--)
1161 tree basetype = BINFO_TYPE (BINFO_BASE_BINFO (TYPE_BINFO (tt1), i));
1162 tree trial = common_base_type (basetype, tt2);
1166 if (trial == error_mark_node)
1168 if (best == NULL_TREE)
1170 else if (best != trial)
1171 return error_mark_node;
1176 for (i = BINFO_N_BASE_BINFOS (TYPE_BINFO (tt2))-1; i >= 0; i--)
1178 tree basetype = BINFO_TYPE (BINFO_BASE_BINFO (TYPE_BINFO (tt2), i));
1179 tree trial = common_base_type (tt1, basetype);
1183 if (trial == error_mark_node)
1185 if (best == NULL_TREE)
1187 else if (best != trial)
1188 return error_mark_node;
1194 /* Subroutines of `comptypes'. */
1196 /* Return true if two parameter type lists PARMS1 and PARMS2 are
1197 equivalent in the sense that functions with those parameter types
1198 can have equivalent types. The two lists must be equivalent,
1199 element by element. */
1202 compparms (tree parms1, tree parms2)
1206 /* An unspecified parmlist matches any specified parmlist
1207 whose argument types don't need default promotions. */
1209 for (t1 = parms1, t2 = parms2;
1211 t1 = TREE_CHAIN (t1), t2 = TREE_CHAIN (t2))
1213 /* If one parmlist is shorter than the other,
1214 they fail to match. */
1217 if (!same_type_p (TREE_VALUE (t1), TREE_VALUE (t2)))
1224 /* Process a sizeof or alignof expression where the operand is a
1228 cxx_sizeof_or_alignof_type (tree type, enum tree_code op, bool complain)
1230 enum tree_code type_code;
1232 const char *op_name;
1234 gcc_assert (op == SIZEOF_EXPR || op == ALIGNOF_EXPR);
1235 if (type == error_mark_node)
1236 return error_mark_node;
1238 if (dependent_type_p (type))
1240 value = build_min (op, size_type_node, type);
1241 TREE_READONLY (value) = 1;
1245 op_name = operator_name_info[(int) op].name;
1247 type = non_reference (type);
1248 type_code = TREE_CODE (type);
1250 if (type_code == METHOD_TYPE)
1252 if (complain && (pedantic || warn_pointer_arith))
1253 pedwarn ("invalid application of %qs to a member function", op_name);
1254 value = size_one_node;
1257 value = c_sizeof_or_alignof_type (complete_type (type),
1264 /* Process a sizeof or alignof expression where the operand is an
1268 cxx_sizeof_or_alignof_expr (tree e, enum tree_code op)
1270 const char *op_name = operator_name_info[(int) op].name;
1272 if (e == error_mark_node)
1273 return error_mark_node;
1275 if (processing_template_decl)
1277 e = build_min (op, size_type_node, e);
1278 TREE_SIDE_EFFECTS (e) = 0;
1279 TREE_READONLY (e) = 1;
1284 if (TREE_CODE (e) == COMPONENT_REF
1285 && TREE_CODE (TREE_OPERAND (e, 1)) == FIELD_DECL
1286 && DECL_C_BIT_FIELD (TREE_OPERAND (e, 1)))
1288 error ("invalid application of %qs to a bit-field", op_name);
1291 else if (is_overloaded_fn (e))
1293 pedwarn ("ISO C++ forbids applying %qs to an expression of "
1294 "function type", op_name);
1297 else if (type_unknown_p (e))
1299 cxx_incomplete_type_error (e, TREE_TYPE (e));
1305 return cxx_sizeof_or_alignof_type (e, op, true);
1309 /* EXPR is being used in a context that is not a function call.
1314 The expression can be used only as the left-hand operand of a
1315 member function call.
1317 [expr.mptr.operator]
1319 If the result of .* or ->* is a function, then that result can be
1320 used only as the operand for the function call operator ().
1322 by issuing an error message if appropriate. Returns true iff EXPR
1323 violates these rules. */
1326 invalid_nonstatic_memfn_p (tree expr)
1328 if (TREE_CODE (TREE_TYPE (expr)) == METHOD_TYPE)
1330 error ("invalid use of non-static member function");
1336 /* Perform the conversions in [expr] that apply when an lvalue appears
1337 in an rvalue context: the lvalue-to-rvalue, array-to-pointer, and
1338 function-to-pointer conversions.
1340 In addition manifest constants are replaced by their values. */
1343 decay_conversion (tree exp)
1346 enum tree_code code;
1348 type = TREE_TYPE (exp);
1349 code = TREE_CODE (type);
1351 if (type == error_mark_node)
1352 return error_mark_node;
1354 if (type_unknown_p (exp))
1356 cxx_incomplete_type_error (exp, TREE_TYPE (exp));
1357 return error_mark_node;
1360 exp = integral_constant_value (exp);
1362 /* build_c_cast puts on a NOP_EXPR to make the result not an lvalue.
1363 Leave such NOP_EXPRs, since RHS is being used in non-lvalue context. */
1365 if (code == VOID_TYPE)
1367 error ("void value not ignored as it ought to be");
1368 return error_mark_node;
1370 if (invalid_nonstatic_memfn_p (exp))
1371 return error_mark_node;
1372 if (code == FUNCTION_TYPE || is_overloaded_fn (exp))
1373 return build_unary_op (ADDR_EXPR, exp, 0);
1374 if (code == ARRAY_TYPE)
1379 if (TREE_CODE (exp) == INDIRECT_REF)
1380 return build_nop (build_pointer_type (TREE_TYPE (type)),
1381 TREE_OPERAND (exp, 0));
1383 if (TREE_CODE (exp) == COMPOUND_EXPR)
1385 tree op1 = decay_conversion (TREE_OPERAND (exp, 1));
1386 return build2 (COMPOUND_EXPR, TREE_TYPE (op1),
1387 TREE_OPERAND (exp, 0), op1);
1391 && ! (TREE_CODE (exp) == CONSTRUCTOR && TREE_STATIC (exp)))
1393 error ("invalid use of non-lvalue array");
1394 return error_mark_node;
1397 ptrtype = build_pointer_type (TREE_TYPE (type));
1399 if (TREE_CODE (exp) == VAR_DECL)
1401 if (!cxx_mark_addressable (exp))
1402 return error_mark_node;
1403 adr = build_nop (ptrtype, build_address (exp));
1406 /* This way is better for a COMPONENT_REF since it can
1407 simplify the offset for a component. */
1408 adr = build_unary_op (ADDR_EXPR, exp, 1);
1409 return cp_convert (ptrtype, adr);
1412 /* [basic.lval]: Class rvalues can have cv-qualified types; non-class
1413 rvalues always have cv-unqualified types. */
1414 if (! CLASS_TYPE_P (type))
1415 exp = cp_convert (TYPE_MAIN_VARIANT (type), exp);
1421 default_conversion (tree exp)
1423 exp = decay_conversion (exp);
1425 if (INTEGRAL_OR_ENUMERATION_TYPE_P (TREE_TYPE (exp)))
1426 exp = perform_integral_promotions (exp);
1431 /* EXPR is an expression with an integral or enumeration type.
1432 Perform the integral promotions in [conv.prom], and return the
1436 perform_integral_promotions (tree expr)
1441 type = TREE_TYPE (expr);
1442 gcc_assert (INTEGRAL_OR_ENUMERATION_TYPE_P (type));
1443 promoted_type = type_promotes_to (type);
1444 if (type != promoted_type)
1445 expr = cp_convert (promoted_type, expr);
1449 /* Take the address of an inline function without setting TREE_ADDRESSABLE
1453 inline_conversion (tree exp)
1455 if (TREE_CODE (exp) == FUNCTION_DECL)
1456 exp = build1 (ADDR_EXPR, build_pointer_type (TREE_TYPE (exp)), exp);
1461 /* Returns nonzero iff exp is a STRING_CST or the result of applying
1462 decay_conversion to one. */
1465 string_conv_p (tree totype, tree exp, int warn)
1469 if (! flag_const_strings || TREE_CODE (totype) != POINTER_TYPE)
1472 t = TREE_TYPE (totype);
1473 if (!same_type_p (t, char_type_node)
1474 && !same_type_p (t, wchar_type_node))
1477 if (TREE_CODE (exp) == STRING_CST)
1479 /* Make sure that we don't try to convert between char and wchar_t. */
1480 if (!same_type_p (TYPE_MAIN_VARIANT (TREE_TYPE (TREE_TYPE (exp))), t))
1485 /* Is this a string constant which has decayed to 'const char *'? */
1486 t = build_pointer_type (build_qualified_type (t, TYPE_QUAL_CONST));
1487 if (!same_type_p (TREE_TYPE (exp), t))
1490 if (TREE_CODE (exp) != ADDR_EXPR
1491 || TREE_CODE (TREE_OPERAND (exp, 0)) != STRING_CST)
1495 /* This warning is not very useful, as it complains about printf. */
1496 if (warn && warn_write_strings)
1497 warning (0, "deprecated conversion from string constant to %qT'", totype);
1502 /* Given a COND_EXPR, MIN_EXPR, or MAX_EXPR in T, return it in a form that we
1503 can, for example, use as an lvalue. This code used to be in
1504 unary_complex_lvalue, but we needed it to deal with `a = (d == c) ? b : c'
1505 expressions, where we're dealing with aggregates. But now it's again only
1506 called from unary_complex_lvalue. The case (in particular) that led to
1507 this was with CODE == ADDR_EXPR, since it's not an lvalue when we'd
1511 rationalize_conditional_expr (enum tree_code code, tree t)
1513 /* For MIN_EXPR or MAX_EXPR, fold-const.c has arranged things so that
1514 the first operand is always the one to be used if both operands
1515 are equal, so we know what conditional expression this used to be. */
1516 if (TREE_CODE (t) == MIN_EXPR || TREE_CODE (t) == MAX_EXPR)
1518 /* The following code is incorrect if either operand side-effects. */
1519 gcc_assert (!TREE_SIDE_EFFECTS (TREE_OPERAND (t, 0))
1520 && !TREE_SIDE_EFFECTS (TREE_OPERAND (t, 1)));
1522 build_conditional_expr (build_x_binary_op ((TREE_CODE (t) == MIN_EXPR
1523 ? LE_EXPR : GE_EXPR),
1524 TREE_OPERAND (t, 0),
1525 TREE_OPERAND (t, 1),
1526 /*overloaded_p=*/NULL),
1527 build_unary_op (code, TREE_OPERAND (t, 0), 0),
1528 build_unary_op (code, TREE_OPERAND (t, 1), 0));
1532 build_conditional_expr (TREE_OPERAND (t, 0),
1533 build_unary_op (code, TREE_OPERAND (t, 1), 0),
1534 build_unary_op (code, TREE_OPERAND (t, 2), 0));
1537 /* Given the TYPE of an anonymous union field inside T, return the
1538 FIELD_DECL for the field. If not found return NULL_TREE. Because
1539 anonymous unions can nest, we must also search all anonymous unions
1540 that are directly reachable. */
1543 lookup_anon_field (tree t, tree type)
1547 for (field = TYPE_FIELDS (t); field; field = TREE_CHAIN (field))
1549 if (TREE_STATIC (field))
1551 if (TREE_CODE (field) != FIELD_DECL || DECL_ARTIFICIAL (field))
1554 /* If we find it directly, return the field. */
1555 if (DECL_NAME (field) == NULL_TREE
1556 && type == TYPE_MAIN_VARIANT (TREE_TYPE (field)))
1561 /* Otherwise, it could be nested, search harder. */
1562 if (DECL_NAME (field) == NULL_TREE
1563 && ANON_AGGR_TYPE_P (TREE_TYPE (field)))
1565 tree subfield = lookup_anon_field (TREE_TYPE (field), type);
1573 /* Build an expression representing OBJECT.MEMBER. OBJECT is an
1574 expression; MEMBER is a DECL or baselink. If ACCESS_PATH is
1575 non-NULL, it indicates the path to the base used to name MEMBER.
1576 If PRESERVE_REFERENCE is true, the expression returned will have
1577 REFERENCE_TYPE if the MEMBER does. Otherwise, the expression
1578 returned will have the type referred to by the reference.
1580 This function does not perform access control; that is either done
1581 earlier by the parser when the name of MEMBER is resolved to MEMBER
1582 itself, or later when overload resolution selects one of the
1583 functions indicated by MEMBER. */
1586 build_class_member_access_expr (tree object, tree member,
1587 tree access_path, bool preserve_reference)
1591 tree result = NULL_TREE;
1593 if (object == error_mark_node || member == error_mark_node)
1594 return error_mark_node;
1596 gcc_assert (DECL_P (member) || BASELINK_P (member));
1600 The type of the first expression shall be "class object" (of a
1602 object_type = TREE_TYPE (object);
1603 if (!currently_open_class (object_type)
1604 && !complete_type_or_else (object_type, object))
1605 return error_mark_node;
1606 if (!CLASS_TYPE_P (object_type))
1608 error ("request for member %qD in %qE, which is of non-class type %qT",
1609 member, object, object_type);
1610 return error_mark_node;
1613 /* The standard does not seem to actually say that MEMBER must be a
1614 member of OBJECT_TYPE. However, that is clearly what is
1616 if (DECL_P (member))
1618 member_scope = DECL_CLASS_CONTEXT (member);
1620 if (TREE_DEPRECATED (member))
1621 warn_deprecated_use (member);
1624 member_scope = BINFO_TYPE (BASELINK_BINFO (member));
1625 /* If MEMBER is from an anonymous aggregate, MEMBER_SCOPE will
1626 presently be the anonymous union. Go outwards until we find a
1627 type related to OBJECT_TYPE. */
1628 while (ANON_AGGR_TYPE_P (member_scope)
1629 && !same_type_ignoring_top_level_qualifiers_p (member_scope,
1631 member_scope = TYPE_CONTEXT (member_scope);
1632 if (!member_scope || !DERIVED_FROM_P (member_scope, object_type))
1634 if (TREE_CODE (member) == FIELD_DECL)
1635 error ("invalid use of nonstatic data member %qE", member);
1637 error ("%qD is not a member of %qT", member, object_type);
1638 return error_mark_node;
1641 /* Transform `(a, b).x' into `(*(a, &b)).x', `(a ? b : c).x' into
1642 `(*(a ? &b : &c)).x', and so on. A COND_EXPR is only an lvalue
1643 in the frontend; only _DECLs and _REFs are lvalues in the backend. */
1645 tree temp = unary_complex_lvalue (ADDR_EXPR, object);
1647 object = build_indirect_ref (temp, NULL);
1650 /* In [expr.ref], there is an explicit list of the valid choices for
1651 MEMBER. We check for each of those cases here. */
1652 if (TREE_CODE (member) == VAR_DECL)
1654 /* A static data member. */
1656 /* If OBJECT has side-effects, they are supposed to occur. */
1657 if (TREE_SIDE_EFFECTS (object))
1658 result = build2 (COMPOUND_EXPR, TREE_TYPE (result), object, result);
1660 else if (TREE_CODE (member) == FIELD_DECL)
1662 /* A non-static data member. */
1667 null_object_p = (TREE_CODE (object) == INDIRECT_REF
1668 && integer_zerop (TREE_OPERAND (object, 0)));
1670 /* Convert OBJECT to the type of MEMBER. */
1671 if (!same_type_p (TYPE_MAIN_VARIANT (object_type),
1672 TYPE_MAIN_VARIANT (member_scope)))
1677 binfo = lookup_base (access_path ? access_path : object_type,
1678 member_scope, ba_unique, &kind);
1679 if (binfo == error_mark_node)
1680 return error_mark_node;
1682 /* It is invalid to try to get to a virtual base of a
1683 NULL object. The most common cause is invalid use of
1685 if (null_object_p && kind == bk_via_virtual)
1687 error ("invalid access to non-static data member %qD of "
1690 error ("(perhaps the %<offsetof%> macro was used incorrectly)");
1691 return error_mark_node;
1694 /* Convert to the base. */
1695 object = build_base_path (PLUS_EXPR, object, binfo,
1697 /* If we found the base successfully then we should be able
1698 to convert to it successfully. */
1699 gcc_assert (object != error_mark_node);
1702 /* Complain about other invalid uses of offsetof, even though they will
1703 give the right answer. Note that we complain whether or not they
1704 actually used the offsetof macro, since there's no way to know at this
1705 point. So we just give a warning, instead of a pedwarn. */
1706 /* Do not produce this warning for base class field references, because
1707 we know for a fact that didn't come from offsetof. This does occur
1708 in various testsuite cases where a null object is passed where a
1709 vtable access is required. */
1710 if (null_object_p && warn_invalid_offsetof
1711 && CLASSTYPE_NON_POD_P (object_type)
1712 && !DECL_FIELD_IS_BASE (member)
1713 && !skip_evaluation)
1715 warning (0, "invalid access to non-static data member %qD of NULL object",
1717 warning (0, "(perhaps the %<offsetof%> macro was used incorrectly)");
1720 /* If MEMBER is from an anonymous aggregate, we have converted
1721 OBJECT so that it refers to the class containing the
1722 anonymous union. Generate a reference to the anonymous union
1723 itself, and recur to find MEMBER. */
1724 if (ANON_AGGR_TYPE_P (DECL_CONTEXT (member))
1725 /* When this code is called from build_field_call, the
1726 object already has the type of the anonymous union.
1727 That is because the COMPONENT_REF was already
1728 constructed, and was then disassembled before calling
1729 build_field_call. After the function-call code is
1730 cleaned up, this waste can be eliminated. */
1731 && (!same_type_ignoring_top_level_qualifiers_p
1732 (TREE_TYPE (object), DECL_CONTEXT (member))))
1734 tree anonymous_union;
1736 anonymous_union = lookup_anon_field (TREE_TYPE (object),
1737 DECL_CONTEXT (member));
1738 object = build_class_member_access_expr (object,
1740 /*access_path=*/NULL_TREE,
1741 preserve_reference);
1744 /* Compute the type of the field, as described in [expr.ref]. */
1745 type_quals = TYPE_UNQUALIFIED;
1746 member_type = TREE_TYPE (member);
1747 if (TREE_CODE (member_type) != REFERENCE_TYPE)
1749 type_quals = (cp_type_quals (member_type)
1750 | cp_type_quals (object_type));
1752 /* A field is const (volatile) if the enclosing object, or the
1753 field itself, is const (volatile). But, a mutable field is
1754 not const, even within a const object. */
1755 if (DECL_MUTABLE_P (member))
1756 type_quals &= ~TYPE_QUAL_CONST;
1757 member_type = cp_build_qualified_type (member_type, type_quals);
1760 result = build3 (COMPONENT_REF, member_type, object, member,
1762 result = fold_if_not_in_template (result);
1764 /* Mark the expression const or volatile, as appropriate. Even
1765 though we've dealt with the type above, we still have to mark the
1766 expression itself. */
1767 if (type_quals & TYPE_QUAL_CONST)
1768 TREE_READONLY (result) = 1;
1769 if (type_quals & TYPE_QUAL_VOLATILE)
1770 TREE_THIS_VOLATILE (result) = 1;
1772 else if (BASELINK_P (member))
1774 /* The member is a (possibly overloaded) member function. */
1778 /* If the MEMBER is exactly one static member function, then we
1779 know the type of the expression. Otherwise, we must wait
1780 until overload resolution has been performed. */
1781 functions = BASELINK_FUNCTIONS (member);
1782 if (TREE_CODE (functions) == FUNCTION_DECL
1783 && DECL_STATIC_FUNCTION_P (functions))
1784 type = TREE_TYPE (functions);
1786 type = unknown_type_node;
1787 /* Note that we do not convert OBJECT to the BASELINK_BINFO
1788 base. That will happen when the function is called. */
1789 result = build3 (COMPONENT_REF, type, object, member, NULL_TREE);
1791 else if (TREE_CODE (member) == CONST_DECL)
1793 /* The member is an enumerator. */
1795 /* If OBJECT has side-effects, they are supposed to occur. */
1796 if (TREE_SIDE_EFFECTS (object))
1797 result = build2 (COMPOUND_EXPR, TREE_TYPE (result),
1802 error ("invalid use of %qD", member);
1803 return error_mark_node;
1806 if (!preserve_reference)
1809 If E2 is declared to have type "reference to T", then ... the
1810 type of E1.E2 is T. */
1811 result = convert_from_reference (result);
1816 /* Return the destructor denoted by OBJECT.SCOPE::~DTOR_NAME, or, if
1817 SCOPE is NULL, by OBJECT.~DTOR_NAME. */
1820 lookup_destructor (tree object, tree scope, tree dtor_name)
1822 tree object_type = TREE_TYPE (object);
1823 tree dtor_type = TREE_OPERAND (dtor_name, 0);
1826 if (scope && !check_dtor_name (scope, dtor_name))
1828 error ("qualified type %qT does not match destructor name ~%qT",
1830 return error_mark_node;
1832 if (!DERIVED_FROM_P (dtor_type, TYPE_MAIN_VARIANT (object_type)))
1834 error ("the type being destroyed is %qT, but the destructor refers to %qT",
1835 TYPE_MAIN_VARIANT (object_type), dtor_type);
1836 return error_mark_node;
1838 expr = lookup_member (dtor_type, complete_dtor_identifier,
1839 /*protect=*/1, /*want_type=*/false);
1840 expr = (adjust_result_of_qualified_name_lookup
1841 (expr, dtor_type, object_type));
1845 /* This function is called by the parser to process a class member
1846 access expression of the form OBJECT.NAME. NAME is a node used by
1847 the parser to represent a name; it is not yet a DECL. It may,
1848 however, be a BASELINK where the BASELINK_FUNCTIONS is a
1849 TEMPLATE_ID_EXPR. Templates must be looked up by the parser, and
1850 there is no reason to do the lookup twice, so the parser keeps the
1854 finish_class_member_access_expr (tree object, tree name)
1859 tree access_path = NULL_TREE;
1860 tree orig_object = object;
1861 tree orig_name = name;
1863 if (object == error_mark_node || name == error_mark_node)
1864 return error_mark_node;
1866 /* If OBJECT is an ObjC class instance, we must obey ObjC access rules. */
1867 if (!objc_is_public (object, name))
1868 return error_mark_node;
1870 object_type = TREE_TYPE (object);
1872 if (processing_template_decl)
1874 if (/* If OBJECT_TYPE is dependent, so is OBJECT.NAME. */
1875 dependent_type_p (object_type)
1876 /* If NAME is just an IDENTIFIER_NODE, then the expression
1878 || TREE_CODE (object) == IDENTIFIER_NODE
1879 /* If NAME is "f<args>", where either 'f' or 'args' is
1880 dependent, then the expression is dependent. */
1881 || (TREE_CODE (name) == TEMPLATE_ID_EXPR
1882 && dependent_template_id_p (TREE_OPERAND (name, 0),
1883 TREE_OPERAND (name, 1)))
1884 /* If NAME is "T::X" where "T" is dependent, then the
1885 expression is dependent. */
1886 || (TREE_CODE (name) == SCOPE_REF
1887 && TYPE_P (TREE_OPERAND (name, 0))
1888 && dependent_type_p (TREE_OPERAND (name, 0))))
1889 return build_min_nt (COMPONENT_REF, object, name, NULL_TREE);
1890 object = build_non_dependent_expr (object);
1895 The type of the first expression shall be "class object" (of a
1897 if (!currently_open_class (object_type)
1898 && !complete_type_or_else (object_type, object))
1899 return error_mark_node;
1900 if (!CLASS_TYPE_P (object_type))
1902 error ("request for member %qD in %qE, which is of non-class type %qT",
1903 name, object, object_type);
1904 return error_mark_node;
1907 if (BASELINK_P (name))
1909 /* A member function that has already been looked up. */
1910 gcc_assert (TREE_CODE (BASELINK_FUNCTIONS (name)) == TEMPLATE_ID_EXPR);
1915 bool is_template_id = false;
1916 tree template_args = NULL_TREE;
1919 if (TREE_CODE (name) == TEMPLATE_ID_EXPR)
1921 is_template_id = true;
1922 template_args = TREE_OPERAND (name, 1);
1923 name = TREE_OPERAND (name, 0);
1925 if (TREE_CODE (name) == OVERLOAD)
1926 name = DECL_NAME (get_first_fn (name));
1927 else if (DECL_P (name))
1928 name = DECL_NAME (name);
1931 if (TREE_CODE (name) == SCOPE_REF)
1933 /* A qualified name. The qualifying class or namespace `S' has
1934 already been looked up; it is either a TYPE or a
1935 NAMESPACE_DECL. The member name is either an IDENTIFIER_NODE
1936 or a BIT_NOT_EXPR. */
1937 scope = TREE_OPERAND (name, 0);
1938 name = TREE_OPERAND (name, 1);
1939 gcc_assert (CLASS_TYPE_P (scope)
1940 || TREE_CODE (scope) == NAMESPACE_DECL);
1941 gcc_assert (TREE_CODE (name) == IDENTIFIER_NODE
1942 || TREE_CODE (name) == BIT_NOT_EXPR);
1944 /* If SCOPE is a namespace, then the qualified name does not
1945 name a member of OBJECT_TYPE. */
1946 if (TREE_CODE (scope) == NAMESPACE_DECL)
1948 error ("%<%D::%D%> is not a member of %qT",
1949 scope, name, object_type);
1950 return error_mark_node;
1953 /* Find the base of OBJECT_TYPE corresponding to SCOPE. */
1954 access_path = lookup_base (object_type, scope, ba_check, NULL);
1955 if (access_path == error_mark_node)
1956 return error_mark_node;
1959 error ("%qT is not a base of %qT", scope, object_type);
1960 return error_mark_node;
1966 access_path = object_type;
1969 if (TREE_CODE (name) == BIT_NOT_EXPR)
1970 member = lookup_destructor (object, scope, name);
1973 /* Look up the member. */
1974 member = lookup_member (access_path, name, /*protect=*/1,
1975 /*want_type=*/false);
1976 if (member == NULL_TREE)
1978 error ("%qD has no member named %qE", object_type, name);
1979 return error_mark_node;
1981 if (member == error_mark_node)
1982 return error_mark_node;
1987 tree template = member;
1989 if (BASELINK_P (template))
1990 template = lookup_template_function (template, template_args);
1993 error ("%qD is not a member template function", name);
1994 return error_mark_node;
1999 if (TREE_DEPRECATED (member))
2000 warn_deprecated_use (member);
2002 expr = build_class_member_access_expr (object, member, access_path,
2003 /*preserve_reference=*/false);
2004 if (processing_template_decl && expr != error_mark_node)
2005 return build_min_non_dep (COMPONENT_REF, expr,
2006 orig_object, orig_name, NULL_TREE);
2010 /* Return an expression for the MEMBER_NAME field in the internal
2011 representation of PTRMEM, a pointer-to-member function. (Each
2012 pointer-to-member function type gets its own RECORD_TYPE so it is
2013 more convenient to access the fields by name than by FIELD_DECL.)
2014 This routine converts the NAME to a FIELD_DECL and then creates the
2015 node for the complete expression. */
2018 build_ptrmemfunc_access_expr (tree ptrmem, tree member_name)
2024 /* This code is a stripped down version of
2025 build_class_member_access_expr. It does not work to use that
2026 routine directly because it expects the object to be of class
2028 ptrmem_type = TREE_TYPE (ptrmem);
2029 gcc_assert (TYPE_PTRMEMFUNC_P (ptrmem_type));
2030 member = lookup_member (ptrmem_type, member_name, /*protect=*/0,
2031 /*want_type=*/false);
2032 member_type = cp_build_qualified_type (TREE_TYPE (member),
2033 cp_type_quals (ptrmem_type));
2034 return fold_build3 (COMPONENT_REF, member_type,
2035 ptrmem, member, NULL_TREE);
2038 /* Given an expression PTR for a pointer, return an expression
2039 for the value pointed to.
2040 ERRORSTRING is the name of the operator to appear in error messages.
2042 This function may need to overload OPERATOR_FNNAME.
2043 Must also handle REFERENCE_TYPEs for C++. */
2046 build_x_indirect_ref (tree expr, const char *errorstring)
2048 tree orig_expr = expr;
2051 if (processing_template_decl)
2053 if (type_dependent_expression_p (expr))
2054 return build_min_nt (INDIRECT_REF, expr);
2055 expr = build_non_dependent_expr (expr);
2058 rval = build_new_op (INDIRECT_REF, LOOKUP_NORMAL, expr, NULL_TREE,
2059 NULL_TREE, /*overloaded_p=*/NULL);
2061 rval = build_indirect_ref (expr, errorstring);
2063 if (processing_template_decl && rval != error_mark_node)
2064 return build_min_non_dep (INDIRECT_REF, rval, orig_expr);
2070 build_indirect_ref (tree ptr, const char *errorstring)
2074 if (ptr == error_mark_node)
2075 return error_mark_node;
2077 if (ptr == current_class_ptr)
2078 return current_class_ref;
2080 pointer = (TREE_CODE (TREE_TYPE (ptr)) == REFERENCE_TYPE
2081 ? ptr : decay_conversion (ptr));
2082 type = TREE_TYPE (pointer);
2084 if (POINTER_TYPE_P (type))
2088 If the type of the expression is "pointer to T," the type
2089 of the result is "T."
2091 We must use the canonical variant because certain parts of
2092 the back end, like fold, do pointer comparisons between
2094 tree t = canonical_type_variant (TREE_TYPE (type));
2096 if (VOID_TYPE_P (t))
2098 /* A pointer to incomplete type (other than cv void) can be
2099 dereferenced [expr.unary.op]/1 */
2100 error ("%qT is not a pointer-to-object type", type);
2101 return error_mark_node;
2103 else if (TREE_CODE (pointer) == ADDR_EXPR
2104 && same_type_p (t, TREE_TYPE (TREE_OPERAND (pointer, 0))))
2105 /* The POINTER was something like `&x'. We simplify `*&x' to
2107 return TREE_OPERAND (pointer, 0);
2110 tree ref = build1 (INDIRECT_REF, t, pointer);
2112 /* We *must* set TREE_READONLY when dereferencing a pointer to const,
2113 so that we get the proper error message if the result is used
2114 to assign to. Also, &* is supposed to be a no-op. */
2115 TREE_READONLY (ref) = CP_TYPE_CONST_P (t);
2116 TREE_THIS_VOLATILE (ref) = CP_TYPE_VOLATILE_P (t);
2117 TREE_SIDE_EFFECTS (ref)
2118 = (TREE_THIS_VOLATILE (ref) || TREE_SIDE_EFFECTS (pointer));
2122 /* `pointer' won't be an error_mark_node if we were given a
2123 pointer to member, so it's cool to check for this here. */
2124 else if (TYPE_PTR_TO_MEMBER_P (type))
2125 error ("invalid use of %qs on pointer to member", errorstring);
2126 else if (pointer != error_mark_node)
2129 error ("invalid type argument of %qs", errorstring);
2131 error ("invalid type argument");
2133 return error_mark_node;
2136 /* This handles expressions of the form "a[i]", which denotes
2139 This is logically equivalent in C to *(a+i), but we may do it differently.
2140 If A is a variable or a member, we generate a primitive ARRAY_REF.
2141 This avoids forcing the array out of registers, and can work on
2142 arrays that are not lvalues (for example, members of structures returned
2145 If INDEX is of some user-defined type, it must be converted to
2146 integer type. Otherwise, to make a compatible PLUS_EXPR, it
2147 will inherit the type of the array, which will be some pointer type. */
2150 build_array_ref (tree array, tree idx)
2154 error ("subscript missing in array reference");
2155 return error_mark_node;
2158 if (TREE_TYPE (array) == error_mark_node
2159 || TREE_TYPE (idx) == error_mark_node)
2160 return error_mark_node;
2162 /* If ARRAY is a COMPOUND_EXPR or COND_EXPR, move our reference
2164 switch (TREE_CODE (array))
2168 tree value = build_array_ref (TREE_OPERAND (array, 1), idx);
2169 return build2 (COMPOUND_EXPR, TREE_TYPE (value),
2170 TREE_OPERAND (array, 0), value);
2174 return build_conditional_expr
2175 (TREE_OPERAND (array, 0),
2176 build_array_ref (TREE_OPERAND (array, 1), idx),
2177 build_array_ref (TREE_OPERAND (array, 2), idx));
2183 if (TREE_CODE (TREE_TYPE (array)) == ARRAY_TYPE)
2187 /* Subscripting with type char is likely to lose
2188 on a machine where chars are signed.
2189 So warn on any machine, but optionally.
2190 Don't warn for unsigned char since that type is safe.
2191 Don't warn for signed char because anyone who uses that
2192 must have done so deliberately. */
2193 if (warn_char_subscripts
2194 && TYPE_MAIN_VARIANT (TREE_TYPE (idx)) == char_type_node)
2195 warning (0, "array subscript has type %<char%>");
2197 if (!INTEGRAL_OR_ENUMERATION_TYPE_P (TREE_TYPE (idx)))
2199 error ("array subscript is not an integer");
2200 return error_mark_node;
2203 /* Apply integral promotions *after* noticing character types.
2204 (It is unclear why we do these promotions -- the standard
2205 does not say that we should. In fact, the natural thing would
2206 seem to be to convert IDX to ptrdiff_t; we're performing
2207 pointer arithmetic.) */
2208 idx = perform_integral_promotions (idx);
2210 /* An array that is indexed by a non-constant
2211 cannot be stored in a register; we must be able to do
2212 address arithmetic on its address.
2213 Likewise an array of elements of variable size. */
2214 if (TREE_CODE (idx) != INTEGER_CST
2215 || (COMPLETE_TYPE_P (TREE_TYPE (TREE_TYPE (array)))
2216 && (TREE_CODE (TYPE_SIZE (TREE_TYPE (TREE_TYPE (array))))
2219 if (!cxx_mark_addressable (array))
2220 return error_mark_node;
2223 /* An array that is indexed by a constant value which is not within
2224 the array bounds cannot be stored in a register either; because we
2225 would get a crash in store_bit_field/extract_bit_field when trying
2226 to access a non-existent part of the register. */
2227 if (TREE_CODE (idx) == INTEGER_CST
2228 && TYPE_DOMAIN (TREE_TYPE (array))
2229 && ! int_fits_type_p (idx, TYPE_DOMAIN (TREE_TYPE (array))))
2231 if (!cxx_mark_addressable (array))
2232 return error_mark_node;
2235 if (pedantic && !lvalue_p (array))
2236 pedwarn ("ISO C++ forbids subscripting non-lvalue array");
2238 /* Note in C++ it is valid to subscript a `register' array, since
2239 it is valid to take the address of something with that
2240 storage specification. */
2244 while (TREE_CODE (foo) == COMPONENT_REF)
2245 foo = TREE_OPERAND (foo, 0);
2246 if (TREE_CODE (foo) == VAR_DECL && DECL_REGISTER (foo))
2247 warning (0, "subscripting array declared %<register%>");
2250 type = TREE_TYPE (TREE_TYPE (array));
2251 rval = build4 (ARRAY_REF, type, array, idx, NULL_TREE, NULL_TREE);
2252 /* Array ref is const/volatile if the array elements are
2253 or if the array is.. */
2254 TREE_READONLY (rval)
2255 |= (CP_TYPE_CONST_P (type) | TREE_READONLY (array));
2256 TREE_SIDE_EFFECTS (rval)
2257 |= (CP_TYPE_VOLATILE_P (type) | TREE_SIDE_EFFECTS (array));
2258 TREE_THIS_VOLATILE (rval)
2259 |= (CP_TYPE_VOLATILE_P (type) | TREE_THIS_VOLATILE (array));
2260 return require_complete_type (fold_if_not_in_template (rval));
2264 tree ar = default_conversion (array);
2265 tree ind = default_conversion (idx);
2267 /* Put the integer in IND to simplify error checking. */
2268 if (TREE_CODE (TREE_TYPE (ar)) == INTEGER_TYPE)
2275 if (ar == error_mark_node)
2278 if (TREE_CODE (TREE_TYPE (ar)) != POINTER_TYPE)
2280 error ("subscripted value is neither array nor pointer");
2281 return error_mark_node;
2283 if (TREE_CODE (TREE_TYPE (ind)) != INTEGER_TYPE)
2285 error ("array subscript is not an integer");
2286 return error_mark_node;
2289 return build_indirect_ref (cp_build_binary_op (PLUS_EXPR, ar, ind),
2294 /* Resolve a pointer to member function. INSTANCE is the object
2295 instance to use, if the member points to a virtual member.
2297 This used to avoid checking for virtual functions if basetype
2298 has no virtual functions, according to an earlier ANSI draft.
2299 With the final ISO C++ rules, such an optimization is
2300 incorrect: A pointer to a derived member can be static_cast
2301 to pointer-to-base-member, as long as the dynamic object
2302 later has the right member. */
2305 get_member_function_from_ptrfunc (tree *instance_ptrptr, tree function)
2307 if (TREE_CODE (function) == OFFSET_REF)
2308 function = TREE_OPERAND (function, 1);
2310 if (TYPE_PTRMEMFUNC_P (TREE_TYPE (function)))
2312 tree idx, delta, e1, e2, e3, vtbl, basetype;
2313 tree fntype = TYPE_PTRMEMFUNC_FN_TYPE (TREE_TYPE (function));
2315 tree instance_ptr = *instance_ptrptr;
2316 tree instance_save_expr = 0;
2317 if (instance_ptr == error_mark_node)
2319 if (TREE_CODE (function) == PTRMEM_CST)
2321 /* Extracting the function address from a pmf is only
2322 allowed with -Wno-pmf-conversions. It only works for
2324 e1 = build_addr_func (PTRMEM_CST_MEMBER (function));
2325 e1 = convert (fntype, e1);
2330 error ("object missing in use of %qE", function);
2331 return error_mark_node;
2335 if (TREE_SIDE_EFFECTS (instance_ptr))
2336 instance_ptr = instance_save_expr = save_expr (instance_ptr);
2338 if (TREE_SIDE_EFFECTS (function))
2339 function = save_expr (function);
2341 /* Start by extracting all the information from the PMF itself. */
2342 e3 = pfn_from_ptrmemfunc (function);
2343 delta = build_ptrmemfunc_access_expr (function, delta_identifier);
2344 idx = build1 (NOP_EXPR, vtable_index_type, e3);
2345 switch (TARGET_PTRMEMFUNC_VBIT_LOCATION)
2347 case ptrmemfunc_vbit_in_pfn:
2348 e1 = cp_build_binary_op (BIT_AND_EXPR, idx, integer_one_node);
2349 idx = cp_build_binary_op (MINUS_EXPR, idx, integer_one_node);
2352 case ptrmemfunc_vbit_in_delta:
2353 e1 = cp_build_binary_op (BIT_AND_EXPR, delta, integer_one_node);
2354 delta = cp_build_binary_op (RSHIFT_EXPR, delta, integer_one_node);
2361 /* Convert down to the right base before using the instance. A
2362 special case is that in a pointer to member of class C, C may
2363 be incomplete. In that case, the function will of course be
2364 a member of C, and no conversion is required. In fact,
2365 lookup_base will fail in that case, because incomplete
2366 classes do not have BINFOs. */
2367 basetype = TYPE_METHOD_BASETYPE (TREE_TYPE (fntype));
2368 if (!same_type_ignoring_top_level_qualifiers_p
2369 (basetype, TREE_TYPE (TREE_TYPE (instance_ptr))))
2371 basetype = lookup_base (TREE_TYPE (TREE_TYPE (instance_ptr)),
2372 basetype, ba_check, NULL);
2373 instance_ptr = build_base_path (PLUS_EXPR, instance_ptr, basetype,
2375 if (instance_ptr == error_mark_node)
2376 return error_mark_node;
2378 /* ...and then the delta in the PMF. */
2379 instance_ptr = build2 (PLUS_EXPR, TREE_TYPE (instance_ptr),
2380 instance_ptr, delta);
2382 /* Hand back the adjusted 'this' argument to our caller. */
2383 *instance_ptrptr = instance_ptr;
2385 /* Next extract the vtable pointer from the object. */
2386 vtbl = build1 (NOP_EXPR, build_pointer_type (vtbl_ptr_type_node),
2388 vtbl = build_indirect_ref (vtbl, NULL);
2390 /* Finally, extract the function pointer from the vtable. */
2391 e2 = fold_build2 (PLUS_EXPR, TREE_TYPE (vtbl), vtbl, idx);
2392 e2 = build_indirect_ref (e2, NULL);
2393 TREE_CONSTANT (e2) = 1;
2394 TREE_INVARIANT (e2) = 1;
2396 /* When using function descriptors, the address of the
2397 vtable entry is treated as a function pointer. */
2398 if (TARGET_VTABLE_USES_DESCRIPTORS)
2399 e2 = build1 (NOP_EXPR, TREE_TYPE (e2),
2400 build_unary_op (ADDR_EXPR, e2, /*noconvert=*/1));
2402 TREE_TYPE (e2) = TREE_TYPE (e3);
2403 e1 = build_conditional_expr (e1, e2, e3);
2405 /* Make sure this doesn't get evaluated first inside one of the
2406 branches of the COND_EXPR. */
2407 if (instance_save_expr)
2408 e1 = build2 (COMPOUND_EXPR, TREE_TYPE (e1),
2409 instance_save_expr, e1);
2417 build_function_call (tree function, tree params)
2419 tree fntype, fndecl;
2420 tree coerced_params;
2421 tree name = NULL_TREE;
2423 tree original = function;
2425 /* For Objective-C, convert any calls via a cast to OBJC_TYPE_REF
2426 expressions, like those used for ObjC messenger dispatches. */
2427 function = objc_rewrite_function_call (function, params);
2429 /* build_c_cast puts on a NOP_EXPR to make the result not an lvalue.
2430 Strip such NOP_EXPRs, since FUNCTION is used in non-lvalue context. */
2431 if (TREE_CODE (function) == NOP_EXPR
2432 && TREE_TYPE (function) == TREE_TYPE (TREE_OPERAND (function, 0)))
2433 function = TREE_OPERAND (function, 0);
2435 if (TREE_CODE (function) == FUNCTION_DECL)
2437 name = DECL_NAME (function);
2439 mark_used (function);
2442 /* Convert anything with function type to a pointer-to-function. */
2443 if (pedantic && DECL_MAIN_P (function))
2444 pedwarn ("ISO C++ forbids calling %<::main%> from within program");
2446 /* Differs from default_conversion by not setting TREE_ADDRESSABLE
2447 (because calling an inline function does not mean the function
2448 needs to be separately compiled). */
2450 if (DECL_INLINE (function))
2451 function = inline_conversion (function);
2453 function = build_addr_func (function);
2459 function = build_addr_func (function);
2462 if (function == error_mark_node)
2463 return error_mark_node;
2465 fntype = TREE_TYPE (function);
2467 if (TYPE_PTRMEMFUNC_P (fntype))
2469 error ("must use %<.*%> or %<->*%> to call pointer-to-member "
2470 "function in %<%E (...)%>",
2472 return error_mark_node;
2475 is_method = (TREE_CODE (fntype) == POINTER_TYPE
2476 && TREE_CODE (TREE_TYPE (fntype)) == METHOD_TYPE);
2478 if (!((TREE_CODE (fntype) == POINTER_TYPE
2479 && TREE_CODE (TREE_TYPE (fntype)) == FUNCTION_TYPE)
2481 || TREE_CODE (function) == TEMPLATE_ID_EXPR))
2483 error ("%qE cannot be used as a function", original);
2484 return error_mark_node;
2487 /* fntype now gets the type of function pointed to. */
2488 fntype = TREE_TYPE (fntype);
2490 /* Convert the parameters to the types declared in the
2491 function prototype, or apply default promotions. */
2493 coerced_params = convert_arguments (TYPE_ARG_TYPES (fntype),
2494 params, fndecl, LOOKUP_NORMAL);
2495 if (coerced_params == error_mark_node)
2496 return error_mark_node;
2498 /* Check for errors in format strings and inappropriately
2501 check_function_arguments (TYPE_ATTRIBUTES (fntype), coerced_params);
2503 return build_cxx_call (function, coerced_params);
2506 /* Convert the actual parameter expressions in the list VALUES
2507 to the types in the list TYPELIST.
2508 If parmdecls is exhausted, or when an element has NULL as its type,
2509 perform the default conversions.
2511 NAME is an IDENTIFIER_NODE or 0. It is used only for error messages.
2513 This is also where warnings about wrong number of args are generated.
2515 Return a list of expressions for the parameters as converted.
2517 Both VALUES and the returned value are chains of TREE_LIST nodes
2518 with the elements of the list in the TREE_VALUE slots of those nodes.
2520 In C++, unspecified trailing parameters can be filled in with their
2521 default arguments, if such were specified. Do so here. */
2524 convert_arguments (tree typelist, tree values, tree fndecl, int flags)
2526 tree typetail, valtail;
2527 tree result = NULL_TREE;
2528 const char *called_thing = 0;
2531 /* Argument passing is always copy-initialization. */
2532 flags |= LOOKUP_ONLYCONVERTING;
2536 if (TREE_CODE (TREE_TYPE (fndecl)) == METHOD_TYPE)
2538 if (DECL_NAME (fndecl) == NULL_TREE
2539 || IDENTIFIER_HAS_TYPE_VALUE (DECL_NAME (fndecl)))
2540 called_thing = "constructor";
2542 called_thing = "member function";
2545 called_thing = "function";
2548 for (valtail = values, typetail = typelist;
2550 valtail = TREE_CHAIN (valtail), i++)
2552 tree type = typetail ? TREE_VALUE (typetail) : 0;
2553 tree val = TREE_VALUE (valtail);
2555 if (val == error_mark_node)
2556 return error_mark_node;
2558 if (type == void_type_node)
2562 cp_error_at ("too many arguments to %s %q+#D", called_thing,
2564 error ("at this point in file");
2567 error ("too many arguments to function");
2568 /* In case anybody wants to know if this argument
2571 TREE_TYPE (tree_last (result)) = error_mark_node;
2575 /* build_c_cast puts on a NOP_EXPR to make the result not an lvalue.
2576 Strip such NOP_EXPRs, since VAL is used in non-lvalue context. */
2577 if (TREE_CODE (val) == NOP_EXPR
2578 && TREE_TYPE (val) == TREE_TYPE (TREE_OPERAND (val, 0))
2579 && (type == 0 || TREE_CODE (type) != REFERENCE_TYPE))
2580 val = TREE_OPERAND (val, 0);
2582 if (type == 0 || TREE_CODE (type) != REFERENCE_TYPE)
2584 if (TREE_CODE (TREE_TYPE (val)) == ARRAY_TYPE
2585 || TREE_CODE (TREE_TYPE (val)) == FUNCTION_TYPE
2586 || TREE_CODE (TREE_TYPE (val)) == METHOD_TYPE)
2587 val = decay_conversion (val);
2590 if (val == error_mark_node)
2591 return error_mark_node;
2595 /* Formal parm type is specified by a function prototype. */
2598 if (!COMPLETE_TYPE_P (complete_type (type)))
2601 error ("parameter %P of %qD has incomplete type %qT",
2604 error ("parameter %P has incomplete type %qT", i, type);
2605 parmval = error_mark_node;
2609 parmval = convert_for_initialization
2610 (NULL_TREE, type, val, flags,
2611 "argument passing", fndecl, i);
2612 parmval = convert_for_arg_passing (type, parmval);
2615 if (parmval == error_mark_node)
2616 return error_mark_node;
2618 result = tree_cons (NULL_TREE, parmval, result);
2622 if (fndecl && DECL_BUILT_IN (fndecl)
2623 && DECL_FUNCTION_CODE (fndecl) == BUILT_IN_CONSTANT_P)
2624 /* Don't do ellipsis conversion for __built_in_constant_p
2625 as this will result in spurious warnings for non-POD
2627 val = require_complete_type (val);
2629 val = convert_arg_to_ellipsis (val);
2631 result = tree_cons (NULL_TREE, val, result);
2635 typetail = TREE_CHAIN (typetail);
2638 if (typetail != 0 && typetail != void_list_node)
2640 /* See if there are default arguments that can be used. */
2641 if (TREE_PURPOSE (typetail)
2642 && TREE_CODE (TREE_PURPOSE (typetail)) != DEFAULT_ARG)
2644 for (; typetail != void_list_node; ++i)
2647 = convert_default_arg (TREE_VALUE (typetail),
2648 TREE_PURPOSE (typetail),
2651 if (parmval == error_mark_node)
2652 return error_mark_node;
2654 result = tree_cons (0, parmval, result);
2655 typetail = TREE_CHAIN (typetail);
2656 /* ends with `...'. */
2657 if (typetail == NULL_TREE)
2665 cp_error_at ("too few arguments to %s %q+#D",
2666 called_thing, fndecl);
2667 error ("at this point in file");
2670 error ("too few arguments to function");
2671 return error_mark_list;
2675 return nreverse (result);
2678 /* Build a binary-operation expression, after performing default
2679 conversions on the operands. CODE is the kind of expression to build. */
2682 build_x_binary_op (enum tree_code code, tree arg1, tree arg2,
2692 if (processing_template_decl)
2694 if (type_dependent_expression_p (arg1)
2695 || type_dependent_expression_p (arg2))
2696 return build_min_nt (code, arg1, arg2);
2697 arg1 = build_non_dependent_expr (arg1);
2698 arg2 = build_non_dependent_expr (arg2);
2701 if (code == DOTSTAR_EXPR)
2702 expr = build_m_component_ref (arg1, arg2);
2704 expr = build_new_op (code, LOOKUP_NORMAL, arg1, arg2, NULL_TREE,
2707 if (processing_template_decl && expr != error_mark_node)
2708 return build_min_non_dep (code, expr, orig_arg1, orig_arg2);
2713 /* Build a binary-operation expression without default conversions.
2714 CODE is the kind of expression to build.
2715 This function differs from `build' in several ways:
2716 the data type of the result is computed and recorded in it,
2717 warnings are generated if arg data types are invalid,
2718 special handling for addition and subtraction of pointers is known,
2719 and some optimization is done (operations on narrow ints
2720 are done in the narrower type when that gives the same result).
2721 Constant folding is also done before the result is returned.
2723 Note that the operands will never have enumeral types
2724 because either they have just had the default conversions performed
2725 or they have both just been converted to some other type in which
2726 the arithmetic is to be done.
2728 C++: must do special pointer arithmetic when implementing
2729 multiple inheritance, and deal with pointer to member functions. */
2732 build_binary_op (enum tree_code code, tree orig_op0, tree orig_op1,
2733 int convert_p ATTRIBUTE_UNUSED)
2736 enum tree_code code0, code1;
2739 /* Expression code to give to the expression when it is built.
2740 Normally this is CODE, which is what the caller asked for,
2741 but in some special cases we change it. */
2742 enum tree_code resultcode = code;
2744 /* Data type in which the computation is to be performed.
2745 In the simplest cases this is the common type of the arguments. */
2746 tree result_type = NULL;
2748 /* Nonzero means operands have already been type-converted
2749 in whatever way is necessary.
2750 Zero means they need to be converted to RESULT_TYPE. */
2753 /* Nonzero means create the expression with this type, rather than
2755 tree build_type = 0;
2757 /* Nonzero means after finally constructing the expression
2758 convert it to this type. */
2759 tree final_type = 0;
2763 /* Nonzero if this is an operation like MIN or MAX which can
2764 safely be computed in short if both args are promoted shorts.
2765 Also implies COMMON.
2766 -1 indicates a bitwise operation; this makes a difference
2767 in the exact conditions for when it is safe to do the operation
2768 in a narrower mode. */
2771 /* Nonzero if this is a comparison operation;
2772 if both args are promoted shorts, compare the original shorts.
2773 Also implies COMMON. */
2774 int short_compare = 0;
2776 /* Nonzero if this is a right-shift operation, which can be computed on the
2777 original short and then promoted if the operand is a promoted short. */
2778 int short_shift = 0;
2780 /* Nonzero means set RESULT_TYPE to the common type of the args. */
2783 /* True if both operands have arithmetic type. */
2784 bool arithmetic_types_p;
2786 /* Apply default conversions. */
2790 if (code == TRUTH_AND_EXPR || code == TRUTH_ANDIF_EXPR
2791 || code == TRUTH_OR_EXPR || code == TRUTH_ORIF_EXPR
2792 || code == TRUTH_XOR_EXPR)
2794 if (!really_overloaded_fn (op0))
2795 op0 = decay_conversion (op0);
2796 if (!really_overloaded_fn (op1))
2797 op1 = decay_conversion (op1);
2801 if (!really_overloaded_fn (op0))
2802 op0 = default_conversion (op0);
2803 if (!really_overloaded_fn (op1))
2804 op1 = default_conversion (op1);
2807 /* Strip NON_LVALUE_EXPRs, etc., since we aren't using as an lvalue. */
2808 STRIP_TYPE_NOPS (op0);
2809 STRIP_TYPE_NOPS (op1);
2811 /* DTRT if one side is an overloaded function, but complain about it. */
2812 if (type_unknown_p (op0))
2814 tree t = instantiate_type (TREE_TYPE (op1), op0, tf_none);
2815 if (t != error_mark_node)
2817 pedwarn ("assuming cast to type %qT from overloaded function",
2822 if (type_unknown_p (op1))
2824 tree t = instantiate_type (TREE_TYPE (op0), op1, tf_none);
2825 if (t != error_mark_node)
2827 pedwarn ("assuming cast to type %qT from overloaded function",
2833 type0 = TREE_TYPE (op0);
2834 type1 = TREE_TYPE (op1);
2836 /* The expression codes of the data types of the arguments tell us
2837 whether the arguments are integers, floating, pointers, etc. */
2838 code0 = TREE_CODE (type0);
2839 code1 = TREE_CODE (type1);
2841 /* If an error was already reported for one of the arguments,
2842 avoid reporting another error. */
2844 if (code0 == ERROR_MARK || code1 == ERROR_MARK)
2845 return error_mark_node;
2850 /* Handle the pointer + int case. */
2851 if (code0 == POINTER_TYPE && code1 == INTEGER_TYPE)
2852 return cp_pointer_int_sum (PLUS_EXPR, op0, op1);
2853 else if (code1 == POINTER_TYPE && code0 == INTEGER_TYPE)
2854 return cp_pointer_int_sum (PLUS_EXPR, op1, op0);
2860 /* Subtraction of two similar pointers.
2861 We must subtract them as integers, then divide by object size. */
2862 if (code0 == POINTER_TYPE && code1 == POINTER_TYPE
2863 && same_type_ignoring_top_level_qualifiers_p (TREE_TYPE (type0),
2865 return pointer_diff (op0, op1, common_type (type0, type1));
2866 /* Handle pointer minus int. Just like pointer plus int. */
2867 else if (code0 == POINTER_TYPE && code1 == INTEGER_TYPE)
2868 return cp_pointer_int_sum (MINUS_EXPR, op0, op1);
2877 case TRUNC_DIV_EXPR:
2879 case FLOOR_DIV_EXPR:
2880 case ROUND_DIV_EXPR:
2881 case EXACT_DIV_EXPR:
2882 if ((code0 == INTEGER_TYPE || code0 == REAL_TYPE
2883 || code0 == COMPLEX_TYPE || code0 == VECTOR_TYPE)
2884 && (code1 == INTEGER_TYPE || code1 == REAL_TYPE
2885 || code1 == COMPLEX_TYPE || code1 == VECTOR_TYPE))
2887 if (TREE_CODE (op1) == INTEGER_CST && integer_zerop (op1))
2888 warning (0, "division by zero in %<%E / 0%>", op0);
2889 else if (TREE_CODE (op1) == REAL_CST && real_zerop (op1))
2890 warning (0, "division by zero in %<%E / 0.%>", op0);
2892 if (code0 == COMPLEX_TYPE || code0 == VECTOR_TYPE)
2893 code0 = TREE_CODE (TREE_TYPE (TREE_TYPE (op0)));
2894 if (code1 == COMPLEX_TYPE || code1 == VECTOR_TYPE)
2895 code1 = TREE_CODE (TREE_TYPE (TREE_TYPE (op1)));
2897 if (!(code0 == INTEGER_TYPE && code1 == INTEGER_TYPE))
2898 resultcode = RDIV_EXPR;
2900 /* When dividing two signed integers, we have to promote to int.
2901 unless we divide by a constant != -1. Note that default
2902 conversion will have been performed on the operands at this
2903 point, so we have to dig out the original type to find out if
2905 shorten = ((TREE_CODE (op0) == NOP_EXPR
2906 && TYPE_UNSIGNED (TREE_TYPE (TREE_OPERAND (op0, 0))))
2907 || (TREE_CODE (op1) == INTEGER_CST
2908 && ! integer_all_onesp (op1)));
2917 if ((code0 == INTEGER_TYPE && code1 == INTEGER_TYPE)
2918 || (code0 == VECTOR_TYPE && code1 == VECTOR_TYPE))
2922 case TRUNC_MOD_EXPR:
2923 case FLOOR_MOD_EXPR:
2924 if (code1 == INTEGER_TYPE && integer_zerop (op1))
2925 warning (0, "division by zero in %<%E %% 0%>", op0);
2926 else if (code1 == REAL_TYPE && real_zerop (op1))
2927 warning (0, "division by zero in %<%E %% 0.%>", op0);
2929 if (code0 == INTEGER_TYPE && code1 == INTEGER_TYPE)
2931 /* Although it would be tempting to shorten always here, that loses
2932 on some targets, since the modulo instruction is undefined if the
2933 quotient can't be represented in the computation mode. We shorten
2934 only if unsigned or if dividing by something we know != -1. */
2935 shorten = ((TREE_CODE (op0) == NOP_EXPR
2936 && TYPE_UNSIGNED (TREE_TYPE (TREE_OPERAND (op0, 0))))
2937 || (TREE_CODE (op1) == INTEGER_CST
2938 && ! integer_all_onesp (op1)));
2943 case TRUTH_ANDIF_EXPR:
2944 case TRUTH_ORIF_EXPR:
2945 case TRUTH_AND_EXPR:
2947 result_type = boolean_type_node;
2950 /* Shift operations: result has same type as first operand;
2951 always convert second operand to int.
2952 Also set SHORT_SHIFT if shifting rightward. */
2955 if (code0 == INTEGER_TYPE && code1 == INTEGER_TYPE)
2957 result_type = type0;
2958 if (TREE_CODE (op1) == INTEGER_CST)
2960 if (tree_int_cst_lt (op1, integer_zero_node))
2961 warning (0, "right shift count is negative");
2964 if (! integer_zerop (op1))
2966 if (compare_tree_int (op1, TYPE_PRECISION (type0)) >= 0)
2967 warning (0, "right shift count >= width of type");
2970 /* Convert the shift-count to an integer, regardless of
2971 size of value being shifted. */
2972 if (TYPE_MAIN_VARIANT (TREE_TYPE (op1)) != integer_type_node)
2973 op1 = cp_convert (integer_type_node, op1);
2974 /* Avoid converting op1 to result_type later. */
2980 if (code0 == INTEGER_TYPE && code1 == INTEGER_TYPE)
2982 result_type = type0;
2983 if (TREE_CODE (op1) == INTEGER_CST)
2985 if (tree_int_cst_lt (op1, integer_zero_node))
2986 warning (0, "left shift count is negative");
2987 else if (compare_tree_int (op1, TYPE_PRECISION (type0)) >= 0)
2988 warning (0, "left shift count >= width of type");
2990 /* Convert the shift-count to an integer, regardless of
2991 size of value being shifted. */
2992 if (TYPE_MAIN_VARIANT (TREE_TYPE (op1)) != integer_type_node)
2993 op1 = cp_convert (integer_type_node, op1);
2994 /* Avoid converting op1 to result_type later. */
3001 if (code0 == INTEGER_TYPE && code1 == INTEGER_TYPE)
3003 result_type = type0;
3004 if (TREE_CODE (op1) == INTEGER_CST)
3006 if (tree_int_cst_lt (op1, integer_zero_node))
3007 warning (0, "%s rotate count is negative",
3008 (code == LROTATE_EXPR) ? "left" : "right");
3009 else if (compare_tree_int (op1, TYPE_PRECISION (type0)) >= 0)
3010 warning (0, "%s rotate count >= width of type",
3011 (code == LROTATE_EXPR) ? "left" : "right");
3013 /* Convert the shift-count to an integer, regardless of
3014 size of value being shifted. */
3015 if (TYPE_MAIN_VARIANT (TREE_TYPE (op1)) != integer_type_node)
3016 op1 = cp_convert (integer_type_node, op1);
3022 if (warn_float_equal && (code0 == REAL_TYPE || code1 == REAL_TYPE))
3023 warning (0, "comparing floating point with == or != is unsafe");
3025 build_type = boolean_type_node;
3026 if ((code0 == INTEGER_TYPE || code0 == REAL_TYPE
3027 || code0 == COMPLEX_TYPE)
3028 && (code1 == INTEGER_TYPE || code1 == REAL_TYPE
3029 || code1 == COMPLEX_TYPE))
3031 else if ((code0 == POINTER_TYPE && code1 == POINTER_TYPE)
3032 || (TYPE_PTRMEM_P (type0) && TYPE_PTRMEM_P (type1)))
3033 result_type = composite_pointer_type (type0, type1, op0, op1,
3035 else if ((code0 == POINTER_TYPE || TYPE_PTRMEM_P (type0))
3036 && null_ptr_cst_p (op1))
3037 result_type = type0;
3038 else if ((code1 == POINTER_TYPE || TYPE_PTRMEM_P (type1))
3039 && null_ptr_cst_p (op0))
3040 result_type = type1;
3041 else if (code0 == POINTER_TYPE && code1 == INTEGER_TYPE)
3043 result_type = type0;
3044 error ("ISO C++ forbids comparison between pointer and integer");
3046 else if (code0 == INTEGER_TYPE && code1 == POINTER_TYPE)
3048 result_type = type1;
3049 error ("ISO C++ forbids comparison between pointer and integer");
3051 else if (TYPE_PTRMEMFUNC_P (type0) && null_ptr_cst_p (op1))
3053 op0 = build_ptrmemfunc_access_expr (op0, pfn_identifier);
3054 op1 = cp_convert (TREE_TYPE (op0), integer_zero_node);
3055 result_type = TREE_TYPE (op0);
3057 else if (TYPE_PTRMEMFUNC_P (type1) && null_ptr_cst_p (op0))
3058 return cp_build_binary_op (code, op1, op0);
3059 else if (TYPE_PTRMEMFUNC_P (type0) && TYPE_PTRMEMFUNC_P (type1)
3060 && same_type_p (type0, type1))
3062 /* E will be the final comparison. */
3064 /* E1 and E2 are for scratch. */
3072 if (TREE_SIDE_EFFECTS (op0))
3073 op0 = save_expr (op0);
3074 if (TREE_SIDE_EFFECTS (op1))
3075 op1 = save_expr (op1);
3080 && (!op0.pfn || op0.delta == op1.delta))
3082 The reason for the `!op0.pfn' bit is that a NULL
3083 pointer-to-member is any member with a zero PFN; the
3084 DELTA field is unspecified. */
3085 pfn0 = pfn_from_ptrmemfunc (op0);
3086 pfn1 = pfn_from_ptrmemfunc (op1);
3087 delta0 = build_ptrmemfunc_access_expr (op0,
3089 delta1 = build_ptrmemfunc_access_expr (op1,
3091 e1 = cp_build_binary_op (EQ_EXPR, delta0, delta1);
3092 e2 = cp_build_binary_op (EQ_EXPR,
3094 cp_convert (TREE_TYPE (pfn0),
3095 integer_zero_node));
3096 e1 = cp_build_binary_op (TRUTH_ORIF_EXPR, e1, e2);
3097 e2 = build2 (EQ_EXPR, boolean_type_node, pfn0, pfn1);
3098 e = cp_build_binary_op (TRUTH_ANDIF_EXPR, e2, e1);
3099 if (code == EQ_EXPR)
3101 return cp_build_binary_op (EQ_EXPR, e, integer_zero_node);
3105 gcc_assert (!TYPE_PTRMEMFUNC_P (type0)
3106 || !same_type_p (TYPE_PTRMEMFUNC_FN_TYPE (type0),
3108 gcc_assert (!TYPE_PTRMEMFUNC_P (type1)
3109 || !same_type_p (TYPE_PTRMEMFUNC_FN_TYPE (type1),
3117 if ((code0 == INTEGER_TYPE || code0 == REAL_TYPE)
3118 && (code1 == INTEGER_TYPE || code1 == REAL_TYPE))
3120 else if (code0 == POINTER_TYPE && code1 == POINTER_TYPE)
3121 result_type = composite_pointer_type (type0, type1, op0, op1,
3129 build_type = boolean_type_node;
3130 if ((code0 == INTEGER_TYPE || code0 == REAL_TYPE)
3131 && (code1 == INTEGER_TYPE || code1 == REAL_TYPE))
3133 else if (code0 == POINTER_TYPE && code1 == POINTER_TYPE)
3134 result_type = composite_pointer_type (type0, type1, op0, op1,
3136 else if (code0 == POINTER_TYPE && TREE_CODE (op1) == INTEGER_CST
3137 && integer_zerop (op1))
3138 result_type = type0;
3139 else if (code1 == POINTER_TYPE && TREE_CODE (op0) == INTEGER_CST
3140 && integer_zerop (op0))
3141 result_type = type1;
3142 else if (code0 == POINTER_TYPE && code1 == INTEGER_TYPE)
3144 result_type = type0;
3145 pedwarn ("ISO C++ forbids comparison between pointer and integer");
3147 else if (code0 == INTEGER_TYPE && code1 == POINTER_TYPE)
3149 result_type = type1;
3150 pedwarn ("ISO C++ forbids comparison between pointer and integer");
3154 case UNORDERED_EXPR:
3161 build_type = integer_type_node;
3162 if (code0 != REAL_TYPE || code1 != REAL_TYPE)
3164 error ("unordered comparison on non-floating point argument");
3165 return error_mark_node;
3174 if (((code0 == INTEGER_TYPE || code0 == REAL_TYPE || code0 == COMPLEX_TYPE)
3175 && (code1 == INTEGER_TYPE || code1 == REAL_TYPE
3176 || code1 == COMPLEX_TYPE)))
3177 arithmetic_types_p = 1;
3180 arithmetic_types_p = 0;
3181 /* Vector arithmetic is only allowed when both sides are vectors. */
3182 if (code0 == VECTOR_TYPE && code1 == VECTOR_TYPE)
3184 if (!tree_int_cst_equal (TYPE_SIZE (type0), TYPE_SIZE (type1)))
3185 error ("can't convert between vector values of different size");
3186 arithmetic_types_p = 1;
3189 /* Determine the RESULT_TYPE, if it is not already known. */
3191 && arithmetic_types_p
3192 && (shorten || common || short_compare))
3193 result_type = common_type (type0, type1);
3197 error ("invalid operands of types %qT and %qT to binary %qO",
3198 TREE_TYPE (orig_op0), TREE_TYPE (orig_op1), code);
3199 return error_mark_node;
3202 /* If we're in a template, the only thing we need to know is the
3204 if (processing_template_decl)
3205 return build2 (resultcode,
3206 build_type ? build_type : result_type,
3209 if (arithmetic_types_p)
3211 int none_complex = (code0 != COMPLEX_TYPE && code1 != COMPLEX_TYPE);
3213 /* For certain operations (which identify themselves by shorten != 0)
3214 if both args were extended from the same smaller type,
3215 do the arithmetic in that type and then extend.
3217 shorten !=0 and !=1 indicates a bitwise operation.
3218 For them, this optimization is safe only if
3219 both args are zero-extended or both are sign-extended.
3220 Otherwise, we might change the result.
3221 Eg, (short)-1 | (unsigned short)-1 is (int)-1
3222 but calculated in (unsigned short) it would be (unsigned short)-1. */
3224 if (shorten && none_complex)
3226 int unsigned0, unsigned1;
3227 tree arg0 = get_narrower (op0, &unsigned0);
3228 tree arg1 = get_narrower (op1, &unsigned1);
3229 /* UNS is 1 if the operation to be done is an unsigned one. */
3230 int uns = TYPE_UNSIGNED (result_type);
3233 final_type = result_type;
3235 /* Handle the case that OP0 does not *contain* a conversion
3236 but it *requires* conversion to FINAL_TYPE. */
3238 if (op0 == arg0 && TREE_TYPE (op0) != final_type)
3239 unsigned0 = TYPE_UNSIGNED (TREE_TYPE (op0));
3240 if (op1 == arg1 && TREE_TYPE (op1) != final_type)
3241 unsigned1 = TYPE_UNSIGNED (TREE_TYPE (op1));
3243 /* Now UNSIGNED0 is 1 if ARG0 zero-extends to FINAL_TYPE. */
3245 /* For bitwise operations, signedness of nominal type
3246 does not matter. Consider only how operands were extended. */
3250 /* Note that in all three cases below we refrain from optimizing
3251 an unsigned operation on sign-extended args.
3252 That would not be valid. */
3254 /* Both args variable: if both extended in same way
3255 from same width, do it in that width.
3256 Do it unsigned if args were zero-extended. */
3257 if ((TYPE_PRECISION (TREE_TYPE (arg0))
3258 < TYPE_PRECISION (result_type))
3259 && (TYPE_PRECISION (TREE_TYPE (arg1))
3260 == TYPE_PRECISION (TREE_TYPE (arg0)))
3261 && unsigned0 == unsigned1
3262 && (unsigned0 || !uns))
3263 result_type = c_common_signed_or_unsigned_type
3264 (unsigned0, common_type (TREE_TYPE (arg0), TREE_TYPE (arg1)));
3265 else if (TREE_CODE (arg0) == INTEGER_CST
3266 && (unsigned1 || !uns)
3267 && (TYPE_PRECISION (TREE_TYPE (arg1))
3268 < TYPE_PRECISION (result_type))
3269 && (type = c_common_signed_or_unsigned_type
3270 (unsigned1, TREE_TYPE (arg1)),
3271 int_fits_type_p (arg0, type)))
3273 else if (TREE_CODE (arg1) == INTEGER_CST
3274 && (unsigned0 || !uns)
3275 && (TYPE_PRECISION (TREE_TYPE (arg0))
3276 < TYPE_PRECISION (result_type))
3277 && (type = c_common_signed_or_unsigned_type
3278 (unsigned0, TREE_TYPE (arg0)),
3279 int_fits_type_p (arg1, type)))
3283 /* Shifts can be shortened if shifting right. */
3288 tree arg0 = get_narrower (op0, &unsigned_arg);
3290 final_type = result_type;
3292 if (arg0 == op0 && final_type == TREE_TYPE (op0))
3293 unsigned_arg = TYPE_UNSIGNED (TREE_TYPE (op0));
3295 if (TYPE_PRECISION (TREE_TYPE (arg0)) < TYPE_PRECISION (result_type)
3296 /* We can shorten only if the shift count is less than the
3297 number of bits in the smaller type size. */
3298 && compare_tree_int (op1, TYPE_PRECISION (TREE_TYPE (arg0))) < 0
3299 /* If arg is sign-extended and then unsigned-shifted,
3300 we can simulate this with a signed shift in arg's type
3301 only if the extended result is at least twice as wide
3302 as the arg. Otherwise, the shift could use up all the
3303 ones made by sign-extension and bring in zeros.
3304 We can't optimize that case at all, but in most machines
3305 it never happens because available widths are 2**N. */
3306 && (!TYPE_UNSIGNED (final_type)
3308 || (((unsigned) 2 * TYPE_PRECISION (TREE_TYPE (arg0)))
3309 <= TYPE_PRECISION (result_type))))
3311 /* Do an unsigned shift if the operand was zero-extended. */
3313 = c_common_signed_or_unsigned_type (unsigned_arg,
3315 /* Convert value-to-be-shifted to that type. */
3316 if (TREE_TYPE (op0) != result_type)
3317 op0 = cp_convert (result_type, op0);
3322 /* Comparison operations are shortened too but differently.
3323 They identify themselves by setting short_compare = 1. */
3327 /* Don't write &op0, etc., because that would prevent op0
3328 from being kept in a register.
3329 Instead, make copies of the our local variables and
3330 pass the copies by reference, then copy them back afterward. */
3331 tree xop0 = op0, xop1 = op1, xresult_type = result_type;
3332 enum tree_code xresultcode = resultcode;
3334 = shorten_compare (&xop0, &xop1, &xresult_type, &xresultcode);
3336 return cp_convert (boolean_type_node, val);
3337 op0 = xop0, op1 = xop1;
3339 resultcode = xresultcode;
3342 if ((short_compare || code == MIN_EXPR || code == MAX_EXPR)
3343 && warn_sign_compare
3344 /* Do not warn until the template is instantiated; we cannot
3345 bound the ranges of the arguments until that point. */
3346 && !processing_template_decl)
3348 int op0_signed = !TYPE_UNSIGNED (TREE_TYPE (orig_op0));
3349 int op1_signed = !TYPE_UNSIGNED (TREE_TYPE (orig_op1));
3351 int unsignedp0, unsignedp1;
3352 tree primop0 = get_narrower (op0, &unsignedp0);
3353 tree primop1 = get_narrower (op1, &unsignedp1);
3355 /* Check for comparison of different enum types. */
3356 if (TREE_CODE (TREE_TYPE (orig_op0)) == ENUMERAL_TYPE
3357 && TREE_CODE (TREE_TYPE (orig_op1)) == ENUMERAL_TYPE
3358 && TYPE_MAIN_VARIANT (TREE_TYPE (orig_op0))
3359 != TYPE_MAIN_VARIANT (TREE_TYPE (orig_op1)))
3361 warning (0, "comparison between types %q#T and %q#T",
3362 TREE_TYPE (orig_op0), TREE_TYPE (orig_op1));
3365 /* Give warnings for comparisons between signed and unsigned
3366 quantities that may fail. */
3367 /* Do the checking based on the original operand trees, so that
3368 casts will be considered, but default promotions won't be. */
3370 /* Do not warn if the comparison is being done in a signed type,
3371 since the signed type will only be chosen if it can represent
3372 all the values of the unsigned type. */
3373 if (!TYPE_UNSIGNED (result_type))
3375 /* Do not warn if both operands are unsigned. */
3376 else if (op0_signed == op1_signed)
3378 /* Do not warn if the signed quantity is an unsuffixed
3379 integer literal (or some static constant expression
3380 involving such literals or a conditional expression
3381 involving such literals) and it is non-negative. */
3382 else if ((op0_signed && tree_expr_nonnegative_p (orig_op0))
3383 || (op1_signed && tree_expr_nonnegative_p (orig_op1)))
3385 /* Do not warn if the comparison is an equality operation,
3386 the unsigned quantity is an integral constant and it does
3387 not use the most significant bit of result_type. */
3388 else if ((resultcode == EQ_EXPR || resultcode == NE_EXPR)
3389 && ((op0_signed && TREE_CODE (orig_op1) == INTEGER_CST
3390 && int_fits_type_p (orig_op1, c_common_signed_type
3392 || (op1_signed && TREE_CODE (orig_op0) == INTEGER_CST
3393 && int_fits_type_p (orig_op0, c_common_signed_type
3397 warning (0, "comparison between signed and unsigned integer expressions");
3399 /* Warn if two unsigned values are being compared in a size
3400 larger than their original size, and one (and only one) is the
3401 result of a `~' operator. This comparison will always fail.
3403 Also warn if one operand is a constant, and the constant does not
3404 have all bits set that are set in the ~ operand when it is
3407 if ((TREE_CODE (primop0) == BIT_NOT_EXPR)
3408 ^ (TREE_CODE (primop1) == BIT_NOT_EXPR))
3410 if (TREE_CODE (primop0) == BIT_NOT_EXPR)
3411 primop0 = get_narrower (TREE_OPERAND (op0, 0), &unsignedp0);
3412 if (TREE_CODE (primop1) == BIT_NOT_EXPR)
3413 primop1 = get_narrower (TREE_OPERAND (op1, 0), &unsignedp1);
3415 if (host_integerp (primop0, 0) || host_integerp (primop1, 0))
3418 HOST_WIDE_INT constant, mask;
3422 if (host_integerp (primop0, 0))
3425 unsignedp = unsignedp1;
3426 constant = tree_low_cst (primop0, 0);
3431 unsignedp = unsignedp0;
3432 constant = tree_low_cst (primop1, 0);
3435 bits = TYPE_PRECISION (TREE_TYPE (primop));
3436 if (bits < TYPE_PRECISION (result_type)
3437 && bits < HOST_BITS_PER_LONG && unsignedp)
3439 mask = (~ (HOST_WIDE_INT) 0) << bits;
3440 if ((mask & constant) != mask)
3441 warning (0, "comparison of promoted ~unsigned with constant");
3444 else if (unsignedp0 && unsignedp1
3445 && (TYPE_PRECISION (TREE_TYPE (primop0))
3446 < TYPE_PRECISION (result_type))
3447 && (TYPE_PRECISION (TREE_TYPE (primop1))
3448 < TYPE_PRECISION (result_type)))
3449 warning (0, "comparison of promoted ~unsigned with unsigned");
3454 /* If CONVERTED is zero, both args will be converted to type RESULT_TYPE.
3455 Then the expression will be built.
3456 It will be given type FINAL_TYPE if that is nonzero;
3457 otherwise, it will be given type RESULT_TYPE. */
3459 /* Issue warnings about peculiar, but valid, uses of NULL. */
3460 if (/* It's reasonable to use pointer values as operands of &&
3461 and ||, so NULL is no exception. */
3462 !(code == TRUTH_ANDIF_EXPR || code == TRUTH_ORIF_EXPR)
3463 && (/* If OP0 is NULL and OP1 is not a pointer, or vice versa. */
3464 (orig_op0 == null_node
3465 && TREE_CODE (TREE_TYPE (op1)) != POINTER_TYPE)
3466 /* Or vice versa. */
3467 || (orig_op1 == null_node
3468 && TREE_CODE (TREE_TYPE (op0)) != POINTER_TYPE)
3469 /* Or, both are NULL and the operation was not a comparison. */
3470 || (orig_op0 == null_node && orig_op1 == null_node
3471 && code != EQ_EXPR && code != NE_EXPR)))
3472 /* Some sort of arithmetic operation involving NULL was
3473 performed. Note that pointer-difference and pointer-addition
3474 have already been handled above, and so we don't end up here in
3476 warning (0, "NULL used in arithmetic");
3480 if (TREE_TYPE (op0) != result_type)
3481 op0 = cp_convert (result_type, op0);
3482 if (TREE_TYPE (op1) != result_type)
3483 op1 = cp_convert (result_type, op1);
3485 if (op0 == error_mark_node || op1 == error_mark_node)
3486 return error_mark_node;
3489 if (build_type == NULL_TREE)
3490 build_type = result_type;
3492 result = build2 (resultcode, build_type, op0, op1);
3493 result = fold_if_not_in_template (result);
3494 if (final_type != 0)
3495 result = cp_convert (final_type, result);
3499 /* Return a tree for the sum or difference (RESULTCODE says which)
3500 of pointer PTROP and integer INTOP. */
3503 cp_pointer_int_sum (enum tree_code resultcode, tree ptrop, tree intop)
3505 tree res_type = TREE_TYPE (ptrop);
3507 /* pointer_int_sum() uses size_in_bytes() on the TREE_TYPE(res_type)
3508 in certain circumstance (when it's valid to do so). So we need
3509 to make sure it's complete. We don't need to check here, if we
3510 can actually complete it at all, as those checks will be done in
3511 pointer_int_sum() anyway. */
3512 complete_type (TREE_TYPE (res_type));
3514 return pointer_int_sum (resultcode, ptrop,
3515 fold_if_not_in_template (intop));
3518 /* Return a tree for the difference of pointers OP0 and OP1.
3519 The resulting tree has type int. */
3522 pointer_diff (tree op0, tree op1, tree ptrtype)
3525 tree restype = ptrdiff_type_node;
3526 tree target_type = TREE_TYPE (ptrtype);
3528 if (!complete_type_or_else (target_type, NULL_TREE))
3529 return error_mark_node;
3531 if (pedantic || warn_pointer_arith)
3533 if (TREE_CODE (target_type) == VOID_TYPE)
3534 pedwarn ("ISO C++ forbids using pointer of type %<void *%> in subtraction");
3535 if (TREE_CODE (target_type) == FUNCTION_TYPE)
3536 pedwarn ("ISO C++ forbids using pointer to a function in subtraction");
3537 if (TREE_CODE (target_type) == METHOD_TYPE)
3538 pedwarn ("ISO C++ forbids using pointer to a method in subtraction");
3541 /* First do the subtraction as integers;
3542 then drop through to build the divide operator. */
3544 op0 = cp_build_binary_op (MINUS_EXPR,
3545 cp_convert (restype, op0),
3546 cp_convert (restype, op1));
3548 /* This generates an error if op1 is a pointer to an incomplete type. */
3549 if (!COMPLETE_TYPE_P (TREE_TYPE (TREE_TYPE (op1))))
3550 error ("invalid use of a pointer to an incomplete type in pointer arithmetic");
3552 op1 = (TYPE_PTROB_P (ptrtype)
3553 ? size_in_bytes (target_type)
3554 : integer_one_node);
3556 /* Do the division. */
3558 result = build2 (EXACT_DIV_EXPR, restype, op0, cp_convert (restype, op1));
3559 return fold_if_not_in_template (result);
3562 /* Construct and perhaps optimize a tree representation
3563 for a unary operation. CODE, a tree_code, specifies the operation
3564 and XARG is the operand. */
3567 build_x_unary_op (enum tree_code code, tree xarg)
3569 tree orig_expr = xarg;
3573 if (processing_template_decl)
3575 if (type_dependent_expression_p (xarg))
3576 return build_min_nt (code, xarg, NULL_TREE);
3578 xarg = build_non_dependent_expr (xarg);
3583 /* [expr.unary.op] says:
3585 The address of an object of incomplete type can be taken.
3587 (And is just the ordinary address operator, not an overloaded
3588 "operator &".) However, if the type is a template
3589 specialization, we must complete the type at this point so that
3590 an overloaded "operator &" will be available if required. */
3591 if (code == ADDR_EXPR
3592 && TREE_CODE (xarg) != TEMPLATE_ID_EXPR
3593 && ((CLASS_TYPE_P (TREE_TYPE (xarg))
3594 && !COMPLETE_TYPE_P (complete_type (TREE_TYPE (xarg))))
3595 || (TREE_CODE (xarg) == OFFSET_REF)))
3596 /* Don't look for a function. */;
3598 exp = build_new_op (code, LOOKUP_NORMAL, xarg, NULL_TREE, NULL_TREE,
3599 /*overloaded_p=*/NULL);
3600 if (!exp && code == ADDR_EXPR)
3602 /* A pointer to member-function can be formed only by saying
3604 if (!flag_ms_extensions && TREE_CODE (TREE_TYPE (xarg)) == METHOD_TYPE
3605 && (TREE_CODE (xarg) != OFFSET_REF || !PTRMEM_OK_P (xarg)))
3607 if (TREE_CODE (xarg) != OFFSET_REF)
3609 error ("invalid use of %qE to form a pointer-to-member-function."
3610 " Use a qualified-id.",
3612 return error_mark_node;
3616 error ("parenthesis around %qE cannot be used to form a"
3617 " pointer-to-member-function",
3619 PTRMEM_OK_P (xarg) = 1;
3623 if (TREE_CODE (xarg) == OFFSET_REF)
3625 ptrmem = PTRMEM_OK_P (xarg);
3627 if (!ptrmem && !flag_ms_extensions
3628 && TREE_CODE (TREE_TYPE (TREE_OPERAND (xarg, 1))) == METHOD_TYPE)
3630 /* A single non-static member, make sure we don't allow a
3631 pointer-to-member. */
3632 xarg = build2 (OFFSET_REF, TREE_TYPE (xarg),
3633 TREE_OPERAND (xarg, 0),
3634 ovl_cons (TREE_OPERAND (xarg, 1), NULL_TREE));
3635 PTRMEM_OK_P (xarg) = ptrmem;
3638 else if (TREE_CODE (xarg) == TARGET_EXPR)
3639 warning (0, "taking address of temporary");
3640 exp = build_unary_op (ADDR_EXPR, xarg, 0);
3643 if (processing_template_decl && exp != error_mark_node)
3644 exp = build_min_non_dep (code, exp, orig_expr,
3645 /*For {PRE,POST}{INC,DEC}REMENT_EXPR*/NULL_TREE);
3646 if (TREE_CODE (exp) == ADDR_EXPR)
3647 PTRMEM_OK_P (exp) = ptrmem;
3651 /* Like c_common_truthvalue_conversion, but handle pointer-to-member
3652 constants, where a null value is represented by an INTEGER_CST of
3656 cp_truthvalue_conversion (tree expr)
3658 tree type = TREE_TYPE (expr);
3659 if (TYPE_PTRMEM_P (type))
3660 return build_binary_op (NE_EXPR, expr, integer_zero_node, 1);
3662 return c_common_truthvalue_conversion (expr);
3665 /* Just like cp_truthvalue_conversion, but we want a CLEANUP_POINT_EXPR. */
3668 condition_conversion (tree expr)
3671 if (processing_template_decl)
3673 t = perform_implicit_conversion (boolean_type_node, expr);
3674 t = fold_build_cleanup_point_expr (boolean_type_node, t);
3678 /* Return an ADDR_EXPR giving the address of T. This function
3679 attempts no optimizations or simplifications; it is a low-level
3683 build_address (tree t)
3687 if (error_operand_p (t) || !cxx_mark_addressable (t))
3688 return error_mark_node;
3690 addr = build1 (ADDR_EXPR, build_pointer_type (TREE_TYPE (t)), t);
3695 /* Return a NOP_EXPR converting EXPR to TYPE. */
3698 build_nop (tree type, tree expr)
3700 if (type == error_mark_node || error_operand_p (expr))
3702 return build1 (NOP_EXPR, type, expr);
3705 /* C++: Must handle pointers to members.
3707 Perhaps type instantiation should be extended to handle conversion
3708 from aggregates to types we don't yet know we want? (Or are those
3709 cases typically errors which should be reported?)
3711 NOCONVERT nonzero suppresses the default promotions
3712 (such as from short to int). */
3715 build_unary_op (enum tree_code code, tree xarg, int noconvert)
3717 /* No default_conversion here. It causes trouble for ADDR_EXPR. */
3720 const char *errstring = NULL;
3723 if (arg == error_mark_node)
3724 return error_mark_node;
3728 case UNARY_PLUS_EXPR:
3731 int flags = WANT_ARITH | WANT_ENUM;
3732 /* Unary plus (but not unary minus) is allowed on pointers. */
3733 if (code == UNARY_PLUS_EXPR)
3734 flags |= WANT_POINTER;
3735 arg = build_expr_type_conversion (flags, arg, true);
3737 errstring = (code == NEGATE_EXPR
3738 ? "wrong type argument to unary minus"
3739 : "wrong type argument to unary plus");
3742 if (!noconvert && CP_INTEGRAL_TYPE_P (TREE_TYPE (arg)))
3743 arg = perform_integral_promotions (arg);
3745 /* Make sure the result is not a lvalue: a unary plus or minus
3746 expression is always a rvalue. */
3747 if (real_lvalue_p (arg))
3748 arg = build1 (NON_LVALUE_EXPR, TREE_TYPE (arg), arg);
3754 if (TREE_CODE (TREE_TYPE (arg)) == COMPLEX_TYPE)
3758 arg = default_conversion (arg);
3760 else if (!(arg = build_expr_type_conversion (WANT_INT | WANT_ENUM,
3762 errstring = "wrong type argument to bit-complement";
3763 else if (!noconvert)
3764 arg = perform_integral_promotions (arg);
3768 if (!(arg = build_expr_type_conversion (WANT_ARITH | WANT_ENUM, arg, true)))
3769 errstring = "wrong type argument to abs";
3770 else if (!noconvert)
3771 arg = default_conversion (arg);
3775 /* Conjugating a real value is a no-op, but allow it anyway. */
3776 if (!(arg = build_expr_type_conversion (WANT_ARITH | WANT_ENUM, arg, true)))
3777 errstring = "wrong type argument to conjugation";
3778 else if (!noconvert)
3779 arg = default_conversion (arg);
3782 case TRUTH_NOT_EXPR:
3783 arg = perform_implicit_conversion (boolean_type_node, arg);
3784 val = invert_truthvalue (arg);
3785 if (arg != error_mark_node)
3787 errstring = "in argument to unary !";
3794 if (TREE_CODE (arg) == COMPLEX_CST)
3795 return TREE_REALPART (arg);
3796 else if (TREE_CODE (TREE_TYPE (arg)) == COMPLEX_TYPE)
3798 arg = build1 (REALPART_EXPR, TREE_TYPE (TREE_TYPE (arg)), arg);
3799 return fold_if_not_in_template (arg);
3805 if (TREE_CODE (arg) == COMPLEX_CST)
3806 return TREE_IMAGPART (arg);
3807 else if (TREE_CODE (TREE_TYPE (arg)) == COMPLEX_TYPE)
3809 arg = build1 (IMAGPART_EXPR, TREE_TYPE (TREE_TYPE (arg)), arg);
3810 return fold_if_not_in_template (arg);
3813 return cp_convert (TREE_TYPE (arg), integer_zero_node);
3815 case PREINCREMENT_EXPR:
3816 case POSTINCREMENT_EXPR:
3817 case PREDECREMENT_EXPR:
3818 case POSTDECREMENT_EXPR:
3819 /* Handle complex lvalues (when permitted)
3820 by reduction to simpler cases. */
3822 val = unary_complex_lvalue (code, arg);
3826 /* Increment or decrement the real part of the value,
3827 and don't change the imaginary part. */
3828 if (TREE_CODE (TREE_TYPE (arg)) == COMPLEX_TYPE)
3832 arg = stabilize_reference (arg);
3833 real = build_unary_op (REALPART_EXPR, arg, 1);
3834 imag = build_unary_op (IMAGPART_EXPR, arg, 1);
3835 return build2 (COMPLEX_EXPR, TREE_TYPE (arg),
3836 build_unary_op (code, real, 1), imag);
3839 /* Report invalid types. */
3841 if (!(arg = build_expr_type_conversion (WANT_ARITH | WANT_POINTER,
3844 if (code == PREINCREMENT_EXPR)
3845 errstring ="no pre-increment operator for type";
3846 else if (code == POSTINCREMENT_EXPR)
3847 errstring ="no post-increment operator for type";
3848 else if (code == PREDECREMENT_EXPR)
3849 errstring ="no pre-decrement operator for type";
3851 errstring ="no post-decrement operator for type";
3855 /* Report something read-only. */
3857 if (CP_TYPE_CONST_P (TREE_TYPE (arg))
3858 || TREE_READONLY (arg))
3859 readonly_error (arg, ((code == PREINCREMENT_EXPR
3860 || code == POSTINCREMENT_EXPR)
3861 ? "increment" : "decrement"),
3866 tree result_type = TREE_TYPE (arg);
3868 arg = get_unwidened (arg, 0);
3869 argtype = TREE_TYPE (arg);
3871 /* ARM $5.2.5 last annotation says this should be forbidden. */
3872 if (TREE_CODE (argtype) == ENUMERAL_TYPE)
3873 pedwarn ("ISO C++ forbids %sing an enum",
3874 (code == PREINCREMENT_EXPR || code == POSTINCREMENT_EXPR)
3875 ? "increment" : "decrement");
3877 /* Compute the increment. */
3879 if (TREE_CODE (argtype) == POINTER_TYPE)
3881 tree type = complete_type (TREE_TYPE (argtype));
3883 if (!COMPLETE_OR_VOID_TYPE_P (type))
3884 error ("cannot %s a pointer to incomplete type %qT",
3885 ((code == PREINCREMENT_EXPR
3886 || code == POSTINCREMENT_EXPR)
3887 ? "increment" : "decrement"), TREE_TYPE (argtype));
3888 else if ((pedantic || warn_pointer_arith)
3889 && !TYPE_PTROB_P (argtype))
3890 pedwarn ("ISO C++ forbids %sing a pointer of type %qT",
3891 ((code == PREINCREMENT_EXPR
3892 || code == POSTINCREMENT_EXPR)
3893 ? "increment" : "decrement"), argtype);
3894 inc = cxx_sizeof_nowarn (TREE_TYPE (argtype));
3897 inc = integer_one_node;
3899 inc = cp_convert (argtype, inc);
3901 /* Handle incrementing a cast-expression. */
3903 switch (TREE_CODE (arg))
3908 case FIX_TRUNC_EXPR:
3909 case FIX_FLOOR_EXPR:
3910 case FIX_ROUND_EXPR:
3913 tree incremented, modify, value, compound;
3914 if (! lvalue_p (arg) && pedantic)
3915 pedwarn ("cast to non-reference type used as lvalue");
3916 arg = stabilize_reference (arg);
3917 if (code == PREINCREMENT_EXPR || code == PREDECREMENT_EXPR)
3920 value = save_expr (arg);
3921 incremented = build2 (((code == PREINCREMENT_EXPR
3922 || code == POSTINCREMENT_EXPR)
3923 ? PLUS_EXPR : MINUS_EXPR),
3924 argtype, value, inc);
3926 modify = build_modify_expr (arg, NOP_EXPR, incremented);
3927 compound = build2 (COMPOUND_EXPR, TREE_TYPE (arg),
3930 /* Eliminate warning about unused result of + or -. */
3931 TREE_NO_WARNING (compound) = 1;
3939 /* Complain about anything else that is not a true lvalue. */
3940 if (!lvalue_or_else (arg, ((code == PREINCREMENT_EXPR
3941 || code == POSTINCREMENT_EXPR)
3942 ? lv_increment : lv_decrement)))
3943 return error_mark_node;
3945 /* Forbid using -- on `bool'. */
3946 if (TREE_TYPE (arg) == boolean_type_node)
3948 if (code == POSTDECREMENT_EXPR || code == PREDECREMENT_EXPR)
3950 error ("invalid use of %<--%> on bool variable %qD", arg);
3951 return error_mark_node;
3953 val = boolean_increment (code, arg);
3956 val = build2 (code, TREE_TYPE (arg), arg, inc);
3958 TREE_SIDE_EFFECTS (val) = 1;
3959 return cp_convert (result_type, val);
3963 /* Note that this operation never does default_conversion
3964 regardless of NOCONVERT. */
3966 argtype = lvalue_type (arg);
3968 if (TREE_CODE (arg) == OFFSET_REF)
3971 if (TREE_CODE (argtype) == REFERENCE_TYPE)
3973 tree type = build_pointer_type (TREE_TYPE (argtype));
3974 arg = build1 (CONVERT_EXPR, type, arg);
3977 else if (pedantic && DECL_MAIN_P (arg))
3979 pedwarn ("ISO C++ forbids taking address of function %<::main%>");
3981 /* Let &* cancel out to simplify resulting code. */
3982 if (TREE_CODE (arg) == INDIRECT_REF)
3984 /* We don't need to have `current_class_ptr' wrapped in a
3985 NON_LVALUE_EXPR node. */
3986 if (arg == current_class_ref)
3987 return current_class_ptr;
3989 arg = TREE_OPERAND (arg, 0);
3990 if (TREE_CODE (TREE_TYPE (arg)) == REFERENCE_TYPE)
3992 tree type = build_pointer_type (TREE_TYPE (TREE_TYPE (arg)));
3993 arg = build1 (CONVERT_EXPR, type, arg);
3995 else if (lvalue_p (arg))
3996 /* Don't let this be an lvalue. */
3997 return non_lvalue (arg);
4001 /* Uninstantiated types are all functions. Taking the
4002 address of a function is a no-op, so just return the
4005 gcc_assert (TREE_CODE (arg) != IDENTIFIER_NODE
4006 || !IDENTIFIER_OPNAME_P (arg));
4008 if (TREE_CODE (arg) == COMPONENT_REF && type_unknown_p (arg)
4009 && !really_overloaded_fn (TREE_OPERAND (arg, 1)))
4011 /* They're trying to take the address of a unique non-static
4012 member function. This is ill-formed (except in MS-land),
4013 but let's try to DTRT.
4014 Note: We only handle unique functions here because we don't
4015 want to complain if there's a static overload; non-unique
4016 cases will be handled by instantiate_type. But we need to
4017 handle this case here to allow casts on the resulting PMF.
4018 We could defer this in non-MS mode, but it's easier to give
4019 a useful error here. */
4021 /* Inside constant member functions, the `this' pointer
4022 contains an extra const qualifier. TYPE_MAIN_VARIANT
4023 is used here to remove this const from the diagnostics
4024 and the created OFFSET_REF. */
4025 tree base = TYPE_MAIN_VARIANT (TREE_TYPE (TREE_OPERAND (arg, 0)));
4026 tree name = DECL_NAME (get_first_fn (TREE_OPERAND (arg, 1)));
4028 if (! flag_ms_extensions)
4030 if (current_class_type
4031 && TREE_OPERAND (arg, 0) == current_class_ref)
4032 /* An expression like &memfn. */
4033 pedwarn ("ISO C++ forbids taking the address of an unqualified"
4034 " or parenthesized non-static member function to form"
4035 " a pointer to member function. Say %<&%T::%D%>",
4038 pedwarn ("ISO C++ forbids taking the address of a bound member"
4039 " function to form a pointer to member function."
4043 arg = build_offset_ref (base, name, /*address_p=*/true);
4047 if (type_unknown_p (arg))
4048 return build1 (ADDR_EXPR, unknown_type_node, arg);
4050 /* Handle complex lvalues (when permitted)
4051 by reduction to simpler cases. */
4052 val = unary_complex_lvalue (code, arg);
4056 switch (TREE_CODE (arg))
4061 case FIX_TRUNC_EXPR:
4062 case FIX_FLOOR_EXPR:
4063 case FIX_ROUND_EXPR:
4065 if (! lvalue_p (arg) && pedantic)
4066 pedwarn ("ISO C++ forbids taking the address of a cast to a non-lvalue expression");
4070 arg = OVL_CURRENT (arg);
4074 /* Turn a reference to a non-static data member into a
4075 pointer-to-member. */
4080 if (!PTRMEM_OK_P (arg))
4081 return build_unary_op (code, arg, 0);
4083 t = TREE_OPERAND (arg, 1);
4084 if (TREE_CODE (TREE_TYPE (t)) == REFERENCE_TYPE)
4086 error ("cannot create pointer to reference member %qD", t);
4087 return error_mark_node;
4090 type = build_ptrmem_type (context_for_name_lookup (t),
4092 t = make_ptrmem_cst (type, TREE_OPERAND (arg, 1));
4100 /* Allow the address of a constructor if all the elements
4102 if (TREE_CODE (arg) == CONSTRUCTOR && TREE_HAS_CONSTRUCTOR (arg)
4103 && TREE_CONSTANT (arg))
4105 /* Anything not already handled and not a true memory reference
4107 else if (TREE_CODE (argtype) != FUNCTION_TYPE
4108 && TREE_CODE (argtype) != METHOD_TYPE
4109 && TREE_CODE (arg) != OFFSET_REF
4110 && !lvalue_or_else (arg, lv_addressof))
4111 return error_mark_node;
4113 if (argtype != error_mark_node)
4114 argtype = build_pointer_type (argtype);
4119 if (TREE_CODE (arg) != COMPONENT_REF
4120 /* Inside a template, we are processing a non-dependent
4121 expression so we can just form an ADDR_EXPR with the
4123 || processing_template_decl)
4125 addr = build_address (arg);
4126 if (TREE_CODE (arg) == OFFSET_REF)
4127 PTRMEM_OK_P (addr) = PTRMEM_OK_P (arg);
4129 else if (TREE_CODE (TREE_OPERAND (arg, 1)) == BASELINK)
4131 tree fn = BASELINK_FUNCTIONS (TREE_OPERAND (arg, 1));
4133 /* We can only get here with a single static member
4135 gcc_assert (TREE_CODE (fn) == FUNCTION_DECL
4136 && DECL_STATIC_FUNCTION_P (fn));
4138 addr = build_address (fn);
4139 if (TREE_SIDE_EFFECTS (TREE_OPERAND (arg, 0)))
4140 /* Do not lose object's side effects. */
4141 addr = build2 (COMPOUND_EXPR, TREE_TYPE (addr),
4142 TREE_OPERAND (arg, 0), addr);
4144 else if (DECL_C_BIT_FIELD (TREE_OPERAND (arg, 1)))
4146 error ("attempt to take address of bit-field structure member %qD",
4147 TREE_OPERAND (arg, 1));
4148 return error_mark_node;
4152 tree object = TREE_OPERAND (arg, 0);
4153 tree field = TREE_OPERAND (arg, 1);
4154 gcc_assert (same_type_ignoring_top_level_qualifiers_p
4155 (TREE_TYPE (object), decl_type_context (field)));
4156 addr = build_address (arg);
4159 if (TREE_CODE (argtype) == POINTER_TYPE
4160 && TREE_CODE (TREE_TYPE (argtype)) == METHOD_TYPE)
4162 build_ptrmemfunc_type (argtype);
4163 addr = build_ptrmemfunc (argtype, addr, 0,
4164 /*c_cast_p=*/false);
4177 argtype = TREE_TYPE (arg);
4178 return fold_if_not_in_template (build1 (code, argtype, arg));
4181 error ("%s", errstring);
4182 return error_mark_node;
4185 /* Apply unary lvalue-demanding operator CODE to the expression ARG
4186 for certain kinds of expressions which are not really lvalues
4187 but which we can accept as lvalues.
4189 If ARG is not a kind of expression we can handle, return
4193 unary_complex_lvalue (enum tree_code code, tree arg)
4195 /* Inside a template, making these kinds of adjustments is
4196 pointless; we are only concerned with the type of the
4198 if (processing_template_decl)
4201 /* Handle (a, b) used as an "lvalue". */
4202 if (TREE_CODE (arg) == COMPOUND_EXPR)
4204 tree real_result = build_unary_op (code, TREE_OPERAND (arg, 1), 0);
4205 return build2 (COMPOUND_EXPR, TREE_TYPE (real_result),
4206 TREE_OPERAND (arg, 0), real_result);
4209 /* Handle (a ? b : c) used as an "lvalue". */
4210 if (TREE_CODE (arg) == COND_EXPR
4211 || TREE_CODE (arg) == MIN_EXPR || TREE_CODE (arg) == MAX_EXPR)
4212 return rationalize_conditional_expr (code, arg);
4214 /* Handle (a = b), (++a), and (--a) used as an "lvalue". */
4215 if (TREE_CODE (arg) == MODIFY_EXPR
4216 || TREE_CODE (arg) == PREINCREMENT_EXPR
4217 || TREE_CODE (arg) == PREDECREMENT_EXPR)
4219 tree lvalue = TREE_OPERAND (arg, 0);
4220 if (TREE_SIDE_EFFECTS (lvalue))
4222 lvalue = stabilize_reference (lvalue);
4223 arg = build2 (TREE_CODE (arg), TREE_TYPE (arg),
4224 lvalue, TREE_OPERAND (arg, 1));
4226 return unary_complex_lvalue
4227 (code, build2 (COMPOUND_EXPR, TREE_TYPE (lvalue), arg, lvalue));
4230 if (code != ADDR_EXPR)
4233 /* Handle (a = b) used as an "lvalue" for `&'. */
4234 if (TREE_CODE (arg) == MODIFY_EXPR
4235 || TREE_CODE (arg) == INIT_EXPR)
4237 tree real_result = build_unary_op (code, TREE_OPERAND (arg, 0), 0);
4238 arg = build2 (COMPOUND_EXPR, TREE_TYPE (real_result),
4240 TREE_NO_WARNING (arg) = 1;
4244 if (TREE_CODE (TREE_TYPE (arg)) == FUNCTION_TYPE
4245 || TREE_CODE (TREE_TYPE (arg)) == METHOD_TYPE
4246 || TREE_CODE (arg) == OFFSET_REF)
4249 /* We permit compiler to make function calls returning
4250 objects of aggregate type look like lvalues. */
4254 if (TREE_CODE (targ) == SAVE_EXPR)
4255 targ = TREE_OPERAND (targ, 0);
4257 if (TREE_CODE (targ) == CALL_EXPR && IS_AGGR_TYPE (TREE_TYPE (targ)))
4259 if (TREE_CODE (arg) == SAVE_EXPR)
4262 targ = build_cplus_new (TREE_TYPE (arg), arg);
4263 return build1 (ADDR_EXPR, build_pointer_type (TREE_TYPE (arg)), targ);
4266 if (TREE_CODE (arg) == SAVE_EXPR && TREE_CODE (targ) == INDIRECT_REF)
4267 return build3 (SAVE_EXPR, build_pointer_type (TREE_TYPE (arg)),
4268 TREE_OPERAND (targ, 0), current_function_decl, NULL);
4271 /* Don't let anything else be handled specially. */
4275 /* Mark EXP saying that we need to be able to take the
4276 address of it; it should not be allocated in a register.
4277 Value is true if successful.
4279 C++: we do not allow `current_class_ptr' to be addressable. */
4282 cxx_mark_addressable (tree exp)
4287 switch (TREE_CODE (x))
4294 x = TREE_OPERAND (x, 0);
4298 if (x == current_class_ptr)
4300 error ("cannot take the address of %<this%>, which is an rvalue expression");
4301 TREE_ADDRESSABLE (x) = 1; /* so compiler doesn't die later. */
4307 /* Caller should not be trying to mark initialized
4308 constant fields addressable. */
4309 gcc_assert (DECL_LANG_SPECIFIC (x) == 0
4310 || DECL_IN_AGGR_P (x) == 0
4312 || DECL_EXTERNAL (x));
4317 if (DECL_REGISTER (x) && !TREE_ADDRESSABLE (x)
4318 && !DECL_ARTIFICIAL (x))
4320 if (DECL_HARD_REGISTER (x) != 0)
4323 ("address of explicit register variable %qD requested", x);
4326 else if (extra_warnings)
4328 (0, "address requested for %qD, which is declared %<register%>", x);
4330 TREE_ADDRESSABLE (x) = 1;
4334 TREE_ADDRESSABLE (x) = 1;
4338 TREE_ADDRESSABLE (x) = 1;
4342 TREE_ADDRESSABLE (x) = 1;
4343 cxx_mark_addressable (TREE_OPERAND (x, 0));
4351 /* Build and return a conditional expression IFEXP ? OP1 : OP2. */
4354 build_x_conditional_expr (tree ifexp, tree op1, tree op2)
4356 tree orig_ifexp = ifexp;
4357 tree orig_op1 = op1;
4358 tree orig_op2 = op2;
4361 if (processing_template_decl)
4363 /* The standard says that the expression is type-dependent if
4364 IFEXP is type-dependent, even though the eventual type of the
4365 expression doesn't dependent on IFEXP. */
4366 if (type_dependent_expression_p (ifexp)
4367 /* As a GNU extension, the middle operand may be omitted. */
4368 || (op1 && type_dependent_expression_p (op1))
4369 || type_dependent_expression_p (op2))
4370 return build_min_nt (COND_EXPR, ifexp, op1, op2);
4371 ifexp = build_non_dependent_expr (ifexp);
4373 op1 = build_non_dependent_expr (op1);
4374 op2 = build_non_dependent_expr (op2);
4377 expr = build_conditional_expr (ifexp, op1, op2);
4378 if (processing_template_decl && expr != error_mark_node)
4379 return build_min_non_dep (COND_EXPR, expr,
4380 orig_ifexp, orig_op1, orig_op2);
4384 /* Given a list of expressions, return a compound expression
4385 that performs them all and returns the value of the last of them. */
4387 tree build_x_compound_expr_from_list (tree list, const char *msg)
4389 tree expr = TREE_VALUE (list);
4391 if (TREE_CHAIN (list))
4394 pedwarn ("%s expression list treated as compound expression", msg);
4396 for (list = TREE_CHAIN (list); list; list = TREE_CHAIN (list))
4397 expr = build_x_compound_expr (expr, TREE_VALUE (list));
4403 /* Handle overloading of the ',' operator when needed. */
4406 build_x_compound_expr (tree op1, tree op2)
4409 tree orig_op1 = op1;
4410 tree orig_op2 = op2;
4412 if (processing_template_decl)
4414 if (type_dependent_expression_p (op1)
4415 || type_dependent_expression_p (op2))
4416 return build_min_nt (COMPOUND_EXPR, op1, op2);
4417 op1 = build_non_dependent_expr (op1);
4418 op2 = build_non_dependent_expr (op2);
4421 result = build_new_op (COMPOUND_EXPR, LOOKUP_NORMAL, op1, op2, NULL_TREE,
4422 /*overloaded_p=*/NULL);
4424 result = build_compound_expr (op1, op2);
4426 if (processing_template_decl && result != error_mark_node)
4427 return build_min_non_dep (COMPOUND_EXPR, result, orig_op1, orig_op2);
4432 /* Build a compound expression. */
4435 build_compound_expr (tree lhs, tree rhs)
4437 lhs = convert_to_void (lhs, "left-hand operand of comma");
4439 if (lhs == error_mark_node || rhs == error_mark_node)
4440 return error_mark_node;
4442 if (TREE_CODE (rhs) == TARGET_EXPR)
4444 /* If the rhs is a TARGET_EXPR, then build the compound
4445 expression inside the target_expr's initializer. This
4446 helps the compiler to eliminate unnecessary temporaries. */
4447 tree init = TREE_OPERAND (rhs, 1);
4449 init = build2 (COMPOUND_EXPR, TREE_TYPE (init), lhs, init);
4450 TREE_OPERAND (rhs, 1) = init;
4455 return build2 (COMPOUND_EXPR, TREE_TYPE (rhs), lhs, rhs);
4458 /* Issue a diagnostic message if casting from SRC_TYPE to DEST_TYPE
4459 casts away constness. DIAG_FN gives the function to call if we
4460 need to issue a diagnostic; if it is NULL, no diagnostic will be
4461 issued. DESCRIPTION explains what operation is taking place. */
4464 check_for_casting_away_constness (tree src_type, tree dest_type,
4465 void (*diag_fn)(const char *, ...),
4466 const char *description)
4468 if (diag_fn && casts_away_constness (src_type, dest_type))
4469 error ("%s from type %qT to type %qT casts away constness",
4470 description, src_type, dest_type);
4473 /* Convert EXPR (an expression with pointer-to-member type) to TYPE
4474 (another pointer-to-member type in the same hierarchy) and return
4475 the converted expression. If ALLOW_INVERSE_P is permitted, a
4476 pointer-to-derived may be converted to pointer-to-base; otherwise,
4477 only the other direction is permitted. If C_CAST_P is true, this
4478 conversion is taking place as part of a C-style cast. */
4481 convert_ptrmem (tree type, tree expr, bool allow_inverse_p,
4484 if (TYPE_PTRMEM_P (type))
4488 if (TREE_CODE (expr) == PTRMEM_CST)
4489 expr = cplus_expand_constant (expr);
4490 delta = get_delta_difference (TYPE_PTRMEM_CLASS_TYPE (TREE_TYPE (expr)),
4491 TYPE_PTRMEM_CLASS_TYPE (type),
4494 if (!integer_zerop (delta))
4495 expr = cp_build_binary_op (PLUS_EXPR,
4496 build_nop (ptrdiff_type_node, expr),
4498 return build_nop (type, expr);
4501 return build_ptrmemfunc (TYPE_PTRMEMFUNC_FN_TYPE (type), expr,
4502 allow_inverse_p, c_cast_p);
4505 /* Perform a static_cast from EXPR to TYPE. When C_CAST_P is true,
4506 this static_cast is being attempted as one of the possible casts
4507 allowed by a C-style cast. (In that case, accessibility of base
4508 classes is not considered, and it is OK to cast away
4509 constness.) Return the result of the cast. *VALID_P is set to
4510 indicate whether or not the cast was valid. */
4513 build_static_cast_1 (tree type, tree expr, bool c_cast_p,
4519 void (*diag_fn)(const char*, ...);
4522 /* Assume the cast is valid. */
4525 intype = TREE_TYPE (expr);
4527 /* Determine what to do when casting away constness. */
4530 /* C-style casts are allowed to cast away constness. With
4531 WARN_CAST_QUAL, we still want to issue a warning. */
4532 diag_fn = warn_cast_qual ? warning0 : NULL;
4537 /* A static_cast may not cast away constness. */
4539 desc = "static_cast";
4542 /* [expr.static.cast]
4544 An lvalue of type "cv1 B", where B is a class type, can be cast
4545 to type "reference to cv2 D", where D is a class derived (clause
4546 _class.derived_) from B, if a valid standard conversion from
4547 "pointer to D" to "pointer to B" exists (_conv.ptr_), cv2 is the
4548 same cv-qualification as, or greater cv-qualification than, cv1,
4549 and B is not a virtual base class of D. */
4550 /* We check this case before checking the validity of "TYPE t =
4551 EXPR;" below because for this case:
4554 struct D : public B { D(const B&); };
4556 void f() { static_cast<const D&>(b); }
4558 we want to avoid constructing a new D. The standard is not
4559 completely clear about this issue, but our interpretation is
4560 consistent with other compilers. */
4561 if (TREE_CODE (type) == REFERENCE_TYPE
4562 && CLASS_TYPE_P (TREE_TYPE (type))
4563 && CLASS_TYPE_P (intype)
4564 && real_lvalue_p (expr)
4565 && DERIVED_FROM_P (intype, TREE_TYPE (type))
4566 && can_convert (build_pointer_type (TYPE_MAIN_VARIANT (intype)),
4567 build_pointer_type (TYPE_MAIN_VARIANT
4568 (TREE_TYPE (type))))
4570 || at_least_as_qualified_p (TREE_TYPE (type), intype)))
4574 /* There is a standard conversion from "D*" to "B*" even if "B"
4575 is ambiguous or inaccessible. If this is really a
4576 static_cast, then we check both for inaccessibility and
4577 ambiguity. However, if this is a static_cast being performed
4578 because the user wrote a C-style cast, then accessibility is
4580 base = lookup_base (TREE_TYPE (type), intype,
4581 c_cast_p ? ba_unique : ba_check,
4584 /* Convert from "B*" to "D*". This function will check that "B"
4585 is not a virtual base of "D". */
4586 expr = build_base_path (MINUS_EXPR, build_address (expr),
4587 base, /*nonnull=*/false);
4588 /* Convert the pointer to a reference -- but then remember that
4589 there are no expressions with reference type in C++. */
4590 return convert_from_reference (build_nop (type, expr));
4595 /* [expr.static.cast]
4597 An expression e can be explicitly converted to a type T using a
4598 static_cast of the form static_cast<T>(e) if the declaration T
4599 t(e);" is well-formed, for some invented temporary variable
4601 result = perform_direct_initialization_if_possible (type, expr,
4605 result = convert_from_reference (result);
4607 /* Ignore any integer overflow caused by the cast. */
4608 if (TREE_CODE (result) == INTEGER_CST
4609 && CONSTANT_CLASS_P (orig))
4611 TREE_OVERFLOW (result) = TREE_OVERFLOW (orig);
4612 TREE_CONSTANT_OVERFLOW (result)
4613 = TREE_CONSTANT_OVERFLOW (orig);
4615 /* [expr.static.cast]
4617 If T is a reference type, the result is an lvalue; otherwise,
4618 the result is an rvalue. */
4619 if (TREE_CODE (type) != REFERENCE_TYPE
4620 && real_lvalue_p (result))
4621 result = build1 (NON_LVALUE_EXPR, TREE_TYPE (result), result);
4625 /* [expr.static.cast]
4627 Any expression can be explicitly converted to type cv void. */
4628 if (TREE_CODE (type) == VOID_TYPE)
4629 return convert_to_void (expr, /*implicit=*/NULL);
4631 /* [expr.static.cast]
4633 The inverse of any standard conversion sequence (clause _conv_),
4634 other than the lvalue-to-rvalue (_conv.lval_), array-to-pointer
4635 (_conv.array_), function-to-pointer (_conv.func_), and boolean
4636 (_conv.bool_) conversions, can be performed explicitly using
4637 static_cast subject to the restriction that the explicit
4638 conversion does not cast away constness (_expr.const.cast_), and
4639 the following additional rules for specific cases: */
4640 /* For reference, the conversions not excluded are: integral
4641 promotions, floating point promotion, integral conversions,
4642 floating point conversions, floating-integral conversions,
4643 pointer conversions, and pointer to member conversions. */
4646 A value of integral _or enumeration_ type can be explicitly
4647 converted to an enumeration type. */
4648 /* The effect of all that is that any conversion between any two
4649 types which are integral, floating, or enumeration types can be
4651 if ((INTEGRAL_TYPE_P (type) || SCALAR_FLOAT_TYPE_P (type))
4652 && (INTEGRAL_TYPE_P (intype) || SCALAR_FLOAT_TYPE_P (intype)))
4654 expr = ocp_convert (type, expr, CONV_C_CAST, LOOKUP_NORMAL);
4656 /* Ignore any integer overflow caused by the cast. */
4657 if (TREE_CODE (expr) == INTEGER_CST
4658 && CONSTANT_CLASS_P (orig))
4660 TREE_OVERFLOW (expr) = TREE_OVERFLOW (orig);
4661 TREE_CONSTANT_OVERFLOW (expr) = TREE_CONSTANT_OVERFLOW (orig);
4666 if (TYPE_PTR_P (type) && TYPE_PTR_P (intype)
4667 && CLASS_TYPE_P (TREE_TYPE (type))
4668 && CLASS_TYPE_P (TREE_TYPE (intype))
4669 && can_convert (build_pointer_type (TYPE_MAIN_VARIANT
4670 (TREE_TYPE (intype))),
4671 build_pointer_type (TYPE_MAIN_VARIANT
4672 (TREE_TYPE (type)))))
4677 check_for_casting_away_constness (intype, type, diag_fn, desc);
4678 base = lookup_base (TREE_TYPE (type), TREE_TYPE (intype),
4679 c_cast_p ? ba_unique : ba_check,
4681 return build_base_path (MINUS_EXPR, expr, base, /*nonnull=*/false);
4684 if ((TYPE_PTRMEM_P (type) && TYPE_PTRMEM_P (intype))
4685 || (TYPE_PTRMEMFUNC_P (type) && TYPE_PTRMEMFUNC_P (intype)))
4692 c1 = TYPE_PTRMEM_CLASS_TYPE (intype);
4693 c2 = TYPE_PTRMEM_CLASS_TYPE (type);
4695 if (TYPE_PTRMEM_P (type))
4697 t1 = (build_ptrmem_type
4699 TYPE_MAIN_VARIANT (TYPE_PTRMEM_POINTED_TO_TYPE (intype))));
4700 t2 = (build_ptrmem_type
4702 TYPE_MAIN_VARIANT (TYPE_PTRMEM_POINTED_TO_TYPE (type))));
4709 if (can_convert (t1, t2))
4712 check_for_casting_away_constness (intype, type, diag_fn,
4714 return convert_ptrmem (type, expr, /*allow_inverse_p=*/1,
4719 /* [expr.static.cast]
4721 An rvalue of type "pointer to cv void" can be explicitly
4722 converted to a pointer to object type. A value of type pointer
4723 to object converted to "pointer to cv void" and back to the
4724 original pointer type will have its original value. */
4725 if (TREE_CODE (intype) == POINTER_TYPE
4726 && VOID_TYPE_P (TREE_TYPE (intype))
4727 && TYPE_PTROB_P (type))
4730 check_for_casting_away_constness (intype, type, diag_fn, desc);
4731 return build_nop (type, expr);
4735 return error_mark_node;
4738 /* Return an expression representing static_cast<TYPE>(EXPR). */
4741 build_static_cast (tree type, tree expr)
4746 if (type == error_mark_node || expr == error_mark_node)
4747 return error_mark_node;
4749 if (processing_template_decl)
4751 expr = build_min (STATIC_CAST_EXPR, type, expr);
4752 /* We don't know if it will or will not have side effects. */
4753 TREE_SIDE_EFFECTS (expr) = 1;
4754 return convert_from_reference (expr);
4757 /* build_c_cast puts on a NOP_EXPR to make the result not an lvalue.
4758 Strip such NOP_EXPRs if VALUE is being used in non-lvalue context. */
4759 if (TREE_CODE (type) != REFERENCE_TYPE
4760 && TREE_CODE (expr) == NOP_EXPR
4761 && TREE_TYPE (expr) == TREE_TYPE (TREE_OPERAND (expr, 0)))
4762 expr = TREE_OPERAND (expr, 0);
4764 result = build_static_cast_1 (type, expr, /*c_cast_p=*/false, &valid_p);
4768 error ("invalid static_cast from type %qT to type %qT",
4769 TREE_TYPE (expr), type);
4770 return error_mark_node;
4773 /* EXPR is an expression with member function or pointer-to-member
4774 function type. TYPE is a pointer type. Converting EXPR to TYPE is
4775 not permitted by ISO C++, but we accept it in some modes. If we
4776 are not in one of those modes, issue a diagnostic. Return the
4777 converted expression. */
4780 convert_member_func_to_ptr (tree type, tree expr)
4785 intype = TREE_TYPE (expr);
4786 gcc_assert (TYPE_PTRMEMFUNC_P (intype)
4787 || TREE_CODE (intype) == METHOD_TYPE);
4789 if (pedantic || warn_pmf2ptr)
4790 pedwarn ("converting from %qT to %qT", intype, type);
4792 if (TREE_CODE (intype) == METHOD_TYPE)
4793 expr = build_addr_func (expr);
4794 else if (TREE_CODE (expr) == PTRMEM_CST)
4795 expr = build_address (PTRMEM_CST_MEMBER (expr));
4798 decl = maybe_dummy_object (TYPE_PTRMEM_CLASS_TYPE (intype), 0);
4799 decl = build_address (decl);
4800 expr = get_member_function_from_ptrfunc (&decl, expr);
4803 return build_nop (type, expr);
4806 /* Return a representation for a reinterpret_cast from EXPR to TYPE.
4807 If C_CAST_P is true, this reinterpret cast is being done as part of
4808 a C-style cast. If VALID_P is non-NULL, *VALID_P is set to
4809 indicate whether or not reinterpret_cast was valid. */
4812 build_reinterpret_cast_1 (tree type, tree expr, bool c_cast_p,
4817 /* Assume the cast is invalid. */
4821 if (type == error_mark_node || error_operand_p (expr))
4822 return error_mark_node;
4824 intype = TREE_TYPE (expr);
4826 /* [expr.reinterpret.cast]
4827 An lvalue expression of type T1 can be cast to the type
4828 "reference to T2" if an expression of type "pointer to T1" can be
4829 explicitly converted to the type "pointer to T2" using a
4830 reinterpret_cast. */
4831 if (TREE_CODE (type) == REFERENCE_TYPE)
4833 if (! real_lvalue_p (expr))
4835 error ("invalid cast of an rvalue expression of type "
4838 return error_mark_node;
4841 /* Warn about a reinterpret_cast from "A*" to "B&" if "A" and
4842 "B" are related class types; the reinterpret_cast does not
4843 adjust the pointer. */
4844 if (TYPE_PTR_P (intype)
4845 && (comptypes (TREE_TYPE (intype), TREE_TYPE (type),
4846 COMPARE_BASE | COMPARE_DERIVED)))
4847 warning (0, "casting %qT to %qT does not dereference pointer",
4850 expr = build_unary_op (ADDR_EXPR, expr, 0);
4851 if (expr != error_mark_node)
4852 expr = build_reinterpret_cast_1
4853 (build_pointer_type (TREE_TYPE (type)), expr, c_cast_p,
4855 if (expr != error_mark_node)
4856 expr = build_indirect_ref (expr, 0);
4860 /* As a G++ extension, we consider conversions from member
4861 functions, and pointers to member functions to
4862 pointer-to-function and pointer-to-void types. If
4863 -Wno-pmf-conversions has not been specified,
4864 convert_member_func_to_ptr will issue an error message. */
4865 if ((TYPE_PTRMEMFUNC_P (intype)
4866 || TREE_CODE (intype) == METHOD_TYPE)
4867 && TYPE_PTR_P (type)
4868 && (TREE_CODE (TREE_TYPE (type)) == FUNCTION_TYPE
4869 || VOID_TYPE_P (TREE_TYPE (type))))
4870 return convert_member_func_to_ptr (type, expr);
4872 /* If the cast is not to a reference type, the lvalue-to-rvalue,
4873 array-to-pointer, and function-to-pointer conversions are
4875 expr = decay_conversion (expr);
4877 /* build_c_cast puts on a NOP_EXPR to make the result not an lvalue.
4878 Strip such NOP_EXPRs if VALUE is being used in non-lvalue context. */
4879 if (TREE_CODE (expr) == NOP_EXPR
4880 && TREE_TYPE (expr) == TREE_TYPE (TREE_OPERAND (expr, 0)))
4881 expr = TREE_OPERAND (expr, 0);
4883 if (error_operand_p (expr))
4884 return error_mark_node;
4886 intype = TREE_TYPE (expr);
4888 /* [expr.reinterpret.cast]
4889 A pointer can be converted to any integral type large enough to
4891 if (CP_INTEGRAL_TYPE_P (type) && TYPE_PTR_P (intype))
4893 if (TYPE_PRECISION (type) < TYPE_PRECISION (intype))
4894 pedwarn ("cast from %qT to %qT loses precision",
4897 /* [expr.reinterpret.cast]
4898 A value of integral or enumeration type can be explicitly
4899 converted to a pointer. */
4900 else if (TYPE_PTR_P (type) && INTEGRAL_OR_ENUMERATION_TYPE_P (intype))
4903 else if ((TYPE_PTRFN_P (type) && TYPE_PTRFN_P (intype))
4904 || (TYPE_PTRMEMFUNC_P (type) && TYPE_PTRMEMFUNC_P (intype)))
4905 return fold_if_not_in_template (build_nop (type, expr));
4906 else if ((TYPE_PTRMEM_P (type) && TYPE_PTRMEM_P (intype))
4907 || (TYPE_PTROBV_P (type) && TYPE_PTROBV_P (intype)))
4910 check_for_casting_away_constness (intype, type, error,
4911 "reinterpret_cast");
4912 /* Warn about possible alignment problems. */
4913 if (STRICT_ALIGNMENT && warn_cast_align
4914 && !VOID_TYPE_P (type)
4915 && TREE_CODE (TREE_TYPE (intype)) != FUNCTION_TYPE
4916 && COMPLETE_TYPE_P (TREE_TYPE (type))
4917 && COMPLETE_TYPE_P (TREE_TYPE (intype))
4918 && TYPE_ALIGN (TREE_TYPE (type)) > TYPE_ALIGN (TREE_TYPE (intype)))
4919 warning (0, "cast from %qT to %qT increases required alignment of "
4923 return fold_if_not_in_template (build_nop (type, expr));
4925 else if ((TYPE_PTRFN_P (type) && TYPE_PTROBV_P (intype))
4926 || (TYPE_PTRFN_P (intype) && TYPE_PTROBV_P (type)))
4929 /* Only issue a warning, as we have always supported this
4930 where possible, and it is necessary in some cases. DR 195
4931 addresses this issue, but as of 2004/10/26 is still in
4933 warning (0, "ISO C++ forbids casting between pointer-to-function and pointer-to-object");
4934 return fold_if_not_in_template (build_nop (type, expr));
4936 else if (TREE_CODE (type) == VECTOR_TYPE)
4937 return fold_if_not_in_template (convert_to_vector (type, expr));
4938 else if (TREE_CODE (intype) == VECTOR_TYPE)
4939 return fold_if_not_in_template (convert_to_integer (type, expr));
4944 error ("invalid cast from type %qT to type %qT", intype, type);
4945 return error_mark_node;
4948 return cp_convert (type, expr);
4952 build_reinterpret_cast (tree type, tree expr)
4954 if (type == error_mark_node || expr == error_mark_node)
4955 return error_mark_node;
4957 if (processing_template_decl)
4959 tree t = build_min (REINTERPRET_CAST_EXPR, type, expr);
4961 if (!TREE_SIDE_EFFECTS (t)
4962 && type_dependent_expression_p (expr))
4963 /* There might turn out to be side effects inside expr. */
4964 TREE_SIDE_EFFECTS (t) = 1;
4965 return convert_from_reference (t);
4968 return build_reinterpret_cast_1 (type, expr, /*c_cast_p=*/false,
4972 /* Perform a const_cast from EXPR to TYPE. If the cast is valid,
4973 return an appropriate expression. Otherwise, return
4974 error_mark_node. If the cast is not valid, and COMPLAIN is true,
4975 then a diagnostic will be issued. If VALID_P is non-NULL, its
4976 value upon return will indicate whether or not the conversion
4980 build_const_cast_1 (tree dst_type, tree expr, bool complain,
4984 tree reference_type;
4986 /* Callers are responsible for handling error_mark_node as a
4987 destination type. */
4988 gcc_assert (dst_type != error_mark_node);
4989 /* In a template, callers should be building syntactic
4990 representations of casts, not using this machinery. */
4991 gcc_assert (!processing_template_decl);
4993 /* Assume the conversion is invalid. */
4997 if (!POINTER_TYPE_P (dst_type) && !TYPE_PTRMEM_P (dst_type))
5000 error ("invalid use of const_cast with type %qT, "
5001 "which is not a pointer, "
5002 "reference, nor a pointer-to-data-member type", dst_type);
5003 return error_mark_node;
5006 if (TREE_CODE (TREE_TYPE (dst_type)) == FUNCTION_TYPE)
5009 error ("invalid use of const_cast with type %qT, which is a pointer "
5010 "or reference to a function type", dst_type);
5011 return error_mark_node;
5014 src_type = TREE_TYPE (expr);
5015 /* Expressions do not really have reference types. */
5016 if (TREE_CODE (src_type) == REFERENCE_TYPE)
5017 src_type = TREE_TYPE (src_type);
5019 /* [expr.const.cast]
5021 An lvalue of type T1 can be explicitly converted to an lvalue of
5022 type T2 using the cast const_cast<T2&> (where T1 and T2 are object
5023 types) if a pointer to T1 can be explicitly converted to the type
5024 pointer to T2 using a const_cast. */
5025 if (TREE_CODE (dst_type) == REFERENCE_TYPE)
5027 reference_type = dst_type;
5028 if (! real_lvalue_p (expr))
5031 error ("invalid const_cast of an rvalue of type %qT to type %qT",
5032 src_type, dst_type);
5033 return error_mark_node;
5035 dst_type = build_pointer_type (TREE_TYPE (dst_type));
5036 src_type = build_pointer_type (src_type);
5040 reference_type = NULL_TREE;
5041 /* If the destination type is not a reference type, the
5042 lvalue-to-rvalue, array-to-pointer, and function-to-pointer
5043 conversions are performed. */
5044 src_type = type_decays_to (src_type);
5045 if (src_type == error_mark_node)
5046 return error_mark_node;
5049 if ((TYPE_PTR_P (src_type) || TYPE_PTRMEM_P (src_type))
5050 && comp_ptr_ttypes_const (dst_type, src_type))
5056 expr = build_unary_op (ADDR_EXPR, expr, 0);
5057 expr = build_nop (reference_type, expr);
5058 return convert_from_reference (expr);
5062 expr = decay_conversion (expr);
5063 /* build_c_cast puts on a NOP_EXPR to make the result not an
5064 lvalue. Strip such NOP_EXPRs if VALUE is being used in
5065 non-lvalue context. */
5066 if (TREE_CODE (expr) == NOP_EXPR
5067 && TREE_TYPE (expr) == TREE_TYPE (TREE_OPERAND (expr, 0)))
5068 expr = TREE_OPERAND (expr, 0);
5069 return build_nop (dst_type, expr);
5074 error ("invalid const_cast from type %qT to type %qT",
5075 src_type, dst_type);
5076 return error_mark_node;
5080 build_const_cast (tree type, tree expr)
5082 if (type == error_mark_node || error_operand_p (expr))
5083 return error_mark_node;
5085 if (processing_template_decl)
5087 tree t = build_min (CONST_CAST_EXPR, type, expr);
5089 if (!TREE_SIDE_EFFECTS (t)
5090 && type_dependent_expression_p (expr))
5091 /* There might turn out to be side effects inside expr. */
5092 TREE_SIDE_EFFECTS (t) = 1;
5093 return convert_from_reference (t);
5096 return build_const_cast_1 (type, expr, /*complain=*/true,
5100 /* Build an expression representing an explicit C-style cast to type
5101 TYPE of expression EXPR. */
5104 build_c_cast (tree type, tree expr)
5110 if (type == error_mark_node || error_operand_p (expr))
5111 return error_mark_node;
5113 if (processing_template_decl)
5115 tree t = build_min (CAST_EXPR, type,
5116 tree_cons (NULL_TREE, value, NULL_TREE));
5117 /* We don't know if it will or will not have side effects. */
5118 TREE_SIDE_EFFECTS (t) = 1;
5119 return convert_from_reference (t);
5122 /* Casts to a (pointer to a) specific ObjC class (or 'id' or
5123 'Class') should always be retained, because this information aids
5124 in method lookup. */
5125 if (objc_is_object_ptr (type)
5126 && objc_is_object_ptr (TREE_TYPE (expr)))
5127 return build_nop (type, expr);
5129 /* build_c_cast puts on a NOP_EXPR to make the result not an lvalue.
5130 Strip such NOP_EXPRs if VALUE is being used in non-lvalue context. */
5131 if (TREE_CODE (type) != REFERENCE_TYPE
5132 && TREE_CODE (value) == NOP_EXPR
5133 && TREE_TYPE (value) == TREE_TYPE (TREE_OPERAND (value, 0)))
5134 value = TREE_OPERAND (value, 0);
5136 if (TREE_CODE (type) == ARRAY_TYPE)
5138 /* Allow casting from T1* to T2[] because Cfront allows it.
5139 NIHCL uses it. It is not valid ISO C++ however. */
5140 if (TREE_CODE (TREE_TYPE (expr)) == POINTER_TYPE)
5142 pedwarn ("ISO C++ forbids casting to an array type %qT", type);
5143 type = build_pointer_type (TREE_TYPE (type));
5147 error ("ISO C++ forbids casting to an array type %qT", type);
5148 return error_mark_node;
5152 if (TREE_CODE (type) == FUNCTION_TYPE
5153 || TREE_CODE (type) == METHOD_TYPE)
5155 error ("invalid cast to function type %qT", type);
5156 return error_mark_node;
5159 /* A C-style cast can be a const_cast. */
5160 result = build_const_cast_1 (type, value, /*complain=*/false,
5165 /* Or a static cast. */
5166 result = build_static_cast_1 (type, value, /*c_cast_p=*/true,
5168 /* Or a reinterpret_cast. */
5170 result = build_reinterpret_cast_1 (type, value, /*c_cast_p=*/true,
5172 /* The static_cast or reinterpret_cast may be followed by a
5175 /* A valid cast may result in errors if, for example, a
5176 conversion to am ambiguous base class is required. */
5177 && !error_operand_p (result))
5181 /* Non-class rvalues always have cv-unqualified type. */
5182 if (!CLASS_TYPE_P (type))
5183 type = TYPE_MAIN_VARIANT (type);
5184 result_type = TREE_TYPE (result);
5185 if (!CLASS_TYPE_P (result_type))
5186 result_type = TYPE_MAIN_VARIANT (result_type);
5187 /* If the type of RESULT does not match TYPE, perform a
5188 const_cast to make it match. If the static_cast or
5189 reinterpret_cast succeeded, we will differ by at most
5190 cv-qualification, so the follow-on const_cast is guaranteed
5192 if (!same_type_p (non_reference (type), non_reference (result_type)))
5194 result = build_const_cast_1 (type, result, false, &valid_p);
5195 gcc_assert (valid_p);
5200 return error_mark_node;
5203 /* Build an assignment expression of lvalue LHS from value RHS.
5204 MODIFYCODE is the code for a binary operator that we use
5205 to combine the old value of LHS with RHS to get the new value.
5206 Or else MODIFYCODE is NOP_EXPR meaning do a simple assignment.
5208 C++: If MODIFYCODE is INIT_EXPR, then leave references unbashed. */
5211 build_modify_expr (tree lhs, enum tree_code modifycode, tree rhs)
5215 tree lhstype = TREE_TYPE (lhs);
5216 tree olhstype = lhstype;
5217 tree olhs = NULL_TREE;
5218 bool plain_assign = (modifycode == NOP_EXPR);
5220 /* Avoid duplicate error messages from operands that had errors. */
5221 if (lhs == error_mark_node || rhs == error_mark_node)
5222 return error_mark_node;
5224 /* Handle control structure constructs used as "lvalues". */
5225 switch (TREE_CODE (lhs))
5227 /* Handle --foo = 5; as these are valid constructs in C++. */
5228 case PREDECREMENT_EXPR:
5229 case PREINCREMENT_EXPR:
5230 if (TREE_SIDE_EFFECTS (TREE_OPERAND (lhs, 0)))
5231 lhs = build2 (TREE_CODE (lhs), TREE_TYPE (lhs),
5232 stabilize_reference (TREE_OPERAND (lhs, 0)),
5233 TREE_OPERAND (lhs, 1));
5234 return build2 (COMPOUND_EXPR, lhstype,
5236 build_modify_expr (TREE_OPERAND (lhs, 0),
5239 /* Handle (a, b) used as an "lvalue". */
5241 newrhs = build_modify_expr (TREE_OPERAND (lhs, 1),
5243 if (newrhs == error_mark_node)
5244 return error_mark_node;
5245 return build2 (COMPOUND_EXPR, lhstype,
5246 TREE_OPERAND (lhs, 0), newrhs);
5249 if (TREE_SIDE_EFFECTS (TREE_OPERAND (lhs, 0)))
5250 lhs = build2 (TREE_CODE (lhs), TREE_TYPE (lhs),
5251 stabilize_reference (TREE_OPERAND (lhs, 0)),
5252 TREE_OPERAND (lhs, 1));
5253 newrhs = build_modify_expr (TREE_OPERAND (lhs, 0), modifycode, rhs);
5254 if (newrhs == error_mark_node)
5255 return error_mark_node;
5256 return build2 (COMPOUND_EXPR, lhstype, lhs, newrhs);
5260 /* MIN_EXPR and MAX_EXPR are currently only permitted as lvalues,
5261 when neither operand has side-effects. */
5262 if (!lvalue_or_else (lhs, lv_assign))
5263 return error_mark_node;
5265 gcc_assert (!TREE_SIDE_EFFECTS (TREE_OPERAND (lhs, 0))
5266 && !TREE_SIDE_EFFECTS (TREE_OPERAND (lhs, 1)));
5268 lhs = build3 (COND_EXPR, TREE_TYPE (lhs),
5269 build2 (TREE_CODE (lhs) == MIN_EXPR ? LE_EXPR : GE_EXPR,
5271 TREE_OPERAND (lhs, 0),
5272 TREE_OPERAND (lhs, 1)),
5273 TREE_OPERAND (lhs, 0),
5274 TREE_OPERAND (lhs, 1));
5277 /* Handle (a ? b : c) used as an "lvalue". */
5280 /* Produce (a ? (b = rhs) : (c = rhs))
5281 except that the RHS goes through a save-expr
5282 so the code to compute it is only emitted once. */
5284 tree preeval = NULL_TREE;
5286 rhs = stabilize_expr (rhs, &preeval);
5288 /* Check this here to avoid odd errors when trying to convert
5289 a throw to the type of the COND_EXPR. */
5290 if (!lvalue_or_else (lhs, lv_assign))
5291 return error_mark_node;
5293 cond = build_conditional_expr
5294 (TREE_OPERAND (lhs, 0),
5295 build_modify_expr (cp_convert (TREE_TYPE (lhs),
5296 TREE_OPERAND (lhs, 1)),
5298 build_modify_expr (cp_convert (TREE_TYPE (lhs),
5299 TREE_OPERAND (lhs, 2)),
5302 if (cond == error_mark_node)
5304 /* Make sure the code to compute the rhs comes out
5305 before the split. */
5307 cond = build2 (COMPOUND_EXPR, TREE_TYPE (lhs), preeval, cond);
5315 if (modifycode == INIT_EXPR)
5317 if (TREE_CODE (rhs) == CONSTRUCTOR)
5319 if (! same_type_p (TREE_TYPE (rhs), lhstype))
5320 /* Call convert to generate an error; see PR 11063. */
5321 rhs = convert (lhstype, rhs);
5322 result = build2 (INIT_EXPR, lhstype, lhs, rhs);
5323 TREE_SIDE_EFFECTS (result) = 1;
5326 else if (! IS_AGGR_TYPE (lhstype))
5327 /* Do the default thing. */;
5330 result = build_special_member_call (lhs, complete_ctor_identifier,
5331 build_tree_list (NULL_TREE, rhs),
5332 lhstype, LOOKUP_NORMAL);
5333 if (result == NULL_TREE)
5334 return error_mark_node;
5340 lhs = require_complete_type (lhs);
5341 if (lhs == error_mark_node)
5342 return error_mark_node;
5344 if (modifycode == NOP_EXPR)
5346 /* `operator=' is not an inheritable operator. */
5347 if (! IS_AGGR_TYPE (lhstype))
5348 /* Do the default thing. */;
5351 result = build_new_op (MODIFY_EXPR, LOOKUP_NORMAL,
5352 lhs, rhs, make_node (NOP_EXPR),
5353 /*overloaded_p=*/NULL);
5354 if (result == NULL_TREE)
5355 return error_mark_node;
5362 /* A binary op has been requested. Combine the old LHS
5363 value with the RHS producing the value we should actually
5364 store into the LHS. */
5366 gcc_assert (!PROMOTES_TO_AGGR_TYPE (lhstype, REFERENCE_TYPE));
5367 lhs = stabilize_reference (lhs);
5368 newrhs = cp_build_binary_op (modifycode, lhs, rhs);
5369 if (newrhs == error_mark_node)
5371 error (" in evaluation of %<%Q(%#T, %#T)%>", modifycode,
5372 TREE_TYPE (lhs), TREE_TYPE (rhs));
5373 return error_mark_node;
5376 /* Now it looks like a plain assignment. */
5377 modifycode = NOP_EXPR;
5379 gcc_assert (TREE_CODE (lhstype) != REFERENCE_TYPE);
5380 gcc_assert (TREE_CODE (TREE_TYPE (newrhs)) != REFERENCE_TYPE);
5383 /* The left-hand side must be an lvalue. */
5384 if (!lvalue_or_else (lhs, lv_assign))
5385 return error_mark_node;
5387 /* Warn about modifying something that is `const'. Don't warn if
5388 this is initialization. */
5389 if (modifycode != INIT_EXPR
5390 && (TREE_READONLY (lhs) || CP_TYPE_CONST_P (lhstype)
5391 /* Functions are not modifiable, even though they are
5393 || TREE_CODE (TREE_TYPE (lhs)) == FUNCTION_TYPE
5394 || TREE_CODE (TREE_TYPE (lhs)) == METHOD_TYPE
5395 /* If it's an aggregate and any field is const, then it is
5396 effectively const. */
5397 || (CLASS_TYPE_P (lhstype)
5398 && C_TYPE_FIELDS_READONLY (lhstype))))
5399 readonly_error (lhs, "assignment", 0);
5401 /* If storing into a structure or union member, it has probably been
5402 given type `int'. Compute the type that would go with the actual
5403 amount of storage the member occupies. */
5405 if (TREE_CODE (lhs) == COMPONENT_REF
5406 && (TREE_CODE (lhstype) == INTEGER_TYPE
5407 || TREE_CODE (lhstype) == REAL_TYPE
5408 || TREE_CODE (lhstype) == ENUMERAL_TYPE))
5410 lhstype = TREE_TYPE (get_unwidened (lhs, 0));
5412 /* If storing in a field that is in actuality a short or narrower
5413 than one, we must store in the field in its actual type. */
5415 if (lhstype != TREE_TYPE (lhs))
5417 /* Avoid warnings converting integral types back into enums for
5419 if (TREE_CODE (lhstype) == INTEGER_TYPE
5420 && TREE_CODE (olhstype) == ENUMERAL_TYPE)
5422 if (TREE_SIDE_EFFECTS (lhs))
5423 lhs = stabilize_reference (lhs);
5426 lhs = copy_node (lhs);
5427 TREE_TYPE (lhs) = lhstype;
5431 /* Convert new value to destination type. */
5433 if (TREE_CODE (lhstype) == ARRAY_TYPE)
5437 if (!same_or_base_type_p (TYPE_MAIN_VARIANT (lhstype),
5438 TYPE_MAIN_VARIANT (TREE_TYPE (rhs))))
5440 error ("incompatible types in assignment of %qT to %qT",
5441 TREE_TYPE (rhs), lhstype);
5442 return error_mark_node;
5445 /* Allow array assignment in compiler-generated code. */
5446 if (! DECL_ARTIFICIAL (current_function_decl))
5447 pedwarn ("ISO C++ forbids assignment of arrays");
5449 from_array = TREE_CODE (TREE_TYPE (newrhs)) == ARRAY_TYPE
5450 ? 1 + (modifycode != INIT_EXPR): 0;
5451 return build_vec_init (lhs, NULL_TREE, newrhs, from_array);
5454 if (modifycode == INIT_EXPR)
5455 newrhs = convert_for_initialization (lhs, lhstype, newrhs, LOOKUP_NORMAL,
5456 "initialization", NULL_TREE, 0);
5459 /* Avoid warnings on enum bit fields. */
5460 if (TREE_CODE (olhstype) == ENUMERAL_TYPE
5461 && TREE_CODE (lhstype) == INTEGER_TYPE)
5463 newrhs = convert_for_assignment (olhstype, newrhs, "assignment",
5465 newrhs = convert_force (lhstype, newrhs, 0);
5468 newrhs = convert_for_assignment (lhstype, newrhs, "assignment",
5470 if (TREE_CODE (newrhs) == CALL_EXPR
5471 && TYPE_NEEDS_CONSTRUCTING (lhstype))
5472 newrhs = build_cplus_new (lhstype, newrhs);
5474 /* Can't initialize directly from a TARGET_EXPR, since that would
5475 cause the lhs to be constructed twice, and possibly result in
5476 accidental self-initialization. So we force the TARGET_EXPR to be
5477 expanded without a target. */
5478 if (TREE_CODE (newrhs) == TARGET_EXPR)
5479 newrhs = build2 (COMPOUND_EXPR, TREE_TYPE (newrhs), newrhs,
5480 TREE_OPERAND (newrhs, 0));
5483 if (newrhs == error_mark_node)
5484 return error_mark_node;
5486 if (c_dialect_objc () && flag_objc_gc)
5488 result = objc_generate_write_barrier (lhs, modifycode, newrhs);
5494 result = build2 (modifycode == NOP_EXPR ? MODIFY_EXPR : INIT_EXPR,
5495 lhstype, lhs, newrhs);
5497 TREE_SIDE_EFFECTS (result) = 1;
5499 TREE_NO_WARNING (result) = 1;
5501 /* If we got the LHS in a different type for storing in,
5502 convert the result back to the nominal type of LHS
5503 so that the value we return always has the same type
5504 as the LHS argument. */
5506 if (olhstype == TREE_TYPE (result))
5510 result = build2 (COMPOUND_EXPR, olhstype, result, olhs);
5511 TREE_NO_WARNING (result) = 1;
5514 return convert_for_assignment (olhstype, result, "assignment",
5519 build_x_modify_expr (tree lhs, enum tree_code modifycode, tree rhs)
5521 if (processing_template_decl)
5522 return build_min_nt (MODOP_EXPR, lhs,
5523 build_min_nt (modifycode, NULL_TREE, NULL_TREE), rhs);
5525 if (modifycode != NOP_EXPR)
5527 tree rval = build_new_op (MODIFY_EXPR, LOOKUP_NORMAL, lhs, rhs,
5528 make_node (modifycode),
5529 /*overloaded_p=*/NULL);
5532 TREE_NO_WARNING (rval) = 1;
5536 return build_modify_expr (lhs, modifycode, rhs);
5540 /* Get difference in deltas for different pointer to member function
5541 types. Returns an integer constant of type PTRDIFF_TYPE_NODE. If
5542 the conversion is invalid, the constant is zero. If
5543 ALLOW_INVERSE_P is true, then allow reverse conversions as well.
5544 If C_CAST_P is true this conversion is taking place as part of a
5547 Note that the naming of FROM and TO is kind of backwards; the return
5548 value is what we add to a TO in order to get a FROM. They are named
5549 this way because we call this function to find out how to convert from
5550 a pointer to member of FROM to a pointer to member of TO. */
5553 get_delta_difference (tree from, tree to,
5554 bool allow_inverse_p,
5561 /* Assume no conversion is required. */
5562 result = integer_zero_node;
5563 binfo = lookup_base (to, from, c_cast_p ? ba_unique : ba_check, &kind);
5564 if (kind == bk_inaccessible || kind == bk_ambig)
5565 error (" in pointer to member function conversion");
5568 if (kind != bk_via_virtual)
5569 result = BINFO_OFFSET (binfo);
5572 tree virt_binfo = binfo_from_vbase (binfo);
5574 /* This is a reinterpret cast, we choose to do nothing. */
5575 if (allow_inverse_p)
5576 warning (0, "pointer to member cast via virtual base %qT",
5577 BINFO_TYPE (virt_binfo));
5579 error ("pointer to member conversion via virtual base %qT",
5580 BINFO_TYPE (virt_binfo));
5583 else if (same_type_ignoring_top_level_qualifiers_p (from, to))
5584 /* Pointer to member of incomplete class is permitted*/;
5585 else if (!allow_inverse_p)
5587 error_not_base_type (from, to);
5588 error (" in pointer to member conversion");
5592 binfo = lookup_base (from, to, c_cast_p ? ba_unique : ba_check, &kind);
5595 if (kind != bk_via_virtual)
5596 result = size_diffop (size_zero_node, BINFO_OFFSET (binfo));
5599 /* This is a reinterpret cast, we choose to do nothing. */
5600 tree virt_binfo = binfo_from_vbase (binfo);
5602 warning (0, "pointer to member cast via virtual base %qT",
5603 BINFO_TYPE (virt_binfo));
5608 return fold_if_not_in_template (convert_to_integer (ptrdiff_type_node,
5612 /* Return a constructor for the pointer-to-member-function TYPE using
5613 the other components as specified. */
5616 build_ptrmemfunc1 (tree type, tree delta, tree pfn)
5622 /* Pull the FIELD_DECLs out of the type. */
5623 pfn_field = TYPE_FIELDS (type);
5624 delta_field = TREE_CHAIN (pfn_field);
5626 /* Make sure DELTA has the type we want. */
5627 delta = convert_and_check (delta_type_node, delta);
5629 /* Finish creating the initializer. */
5630 u = tree_cons (pfn_field, pfn,
5631 build_tree_list (delta_field, delta));
5632 u = build_constructor (type, u);
5633 TREE_CONSTANT (u) = TREE_CONSTANT (pfn) & TREE_CONSTANT (delta);
5634 TREE_INVARIANT (u) = TREE_INVARIANT (pfn) & TREE_INVARIANT (delta);
5635 TREE_STATIC (u) = (TREE_CONSTANT (u)
5636 && (initializer_constant_valid_p (pfn, TREE_TYPE (pfn))
5638 && (initializer_constant_valid_p (delta, TREE_TYPE (delta))
5643 /* Build a constructor for a pointer to member function. It can be
5644 used to initialize global variables, local variable, or used
5645 as a value in expressions. TYPE is the POINTER to METHOD_TYPE we
5648 If FORCE is nonzero, then force this conversion, even if
5649 we would rather not do it. Usually set when using an explicit
5650 cast. A C-style cast is being processed iff C_CAST_P is true.
5652 Return error_mark_node, if something goes wrong. */
5655 build_ptrmemfunc (tree type, tree pfn, int force, bool c_cast_p)
5661 if (error_operand_p (pfn))
5662 return error_mark_node;
5664 pfn_type = TREE_TYPE (pfn);
5665 to_type = build_ptrmemfunc_type (type);
5667 /* Handle multiple conversions of pointer to member functions. */
5668 if (TYPE_PTRMEMFUNC_P (pfn_type))
5670 tree delta = NULL_TREE;
5671 tree npfn = NULL_TREE;
5675 && !can_convert_arg (to_type, TREE_TYPE (pfn), pfn))
5676 error ("invalid conversion to type %qT from type %qT",
5679 n = get_delta_difference (TYPE_PTRMEMFUNC_OBJECT_TYPE (pfn_type),
5680 TYPE_PTRMEMFUNC_OBJECT_TYPE (to_type),
5684 /* We don't have to do any conversion to convert a
5685 pointer-to-member to its own type. But, we don't want to
5686 just return a PTRMEM_CST if there's an explicit cast; that
5687 cast should make the expression an invalid template argument. */
5688 if (TREE_CODE (pfn) != PTRMEM_CST)
5690 if (same_type_p (to_type, pfn_type))
5692 else if (integer_zerop (n))
5693 return build_reinterpret_cast (to_type, pfn);
5696 if (TREE_SIDE_EFFECTS (pfn))
5697 pfn = save_expr (pfn);
5699 /* Obtain the function pointer and the current DELTA. */
5700 if (TREE_CODE (pfn) == PTRMEM_CST)
5701 expand_ptrmemfunc_cst (pfn, &delta, &npfn);
5704 npfn = build_ptrmemfunc_access_expr (pfn, pfn_identifier);
5705 delta = build_ptrmemfunc_access_expr (pfn, delta_identifier);
5708 /* Just adjust the DELTA field. */
5709 gcc_assert (same_type_ignoring_top_level_qualifiers_p
5710 (TREE_TYPE (delta), ptrdiff_type_node));
5711 if (TARGET_PTRMEMFUNC_VBIT_LOCATION == ptrmemfunc_vbit_in_delta)
5712 n = cp_build_binary_op (LSHIFT_EXPR, n, integer_one_node);
5713 delta = cp_build_binary_op (PLUS_EXPR, delta, n);
5714 return build_ptrmemfunc1 (to_type, delta, npfn);
5717 /* Handle null pointer to member function conversions. */
5718 if (integer_zerop (pfn))
5720 pfn = build_c_cast (type, integer_zero_node);
5721 return build_ptrmemfunc1 (to_type,
5726 if (type_unknown_p (pfn))
5727 return instantiate_type (type, pfn, tf_error | tf_warning);
5729 fn = TREE_OPERAND (pfn, 0);
5730 gcc_assert (TREE_CODE (fn) == FUNCTION_DECL
5731 /* In a template, we will have preserved the
5733 || (processing_template_decl && TREE_CODE (fn) == OFFSET_REF));
5734 return make_ptrmem_cst (to_type, fn);
5737 /* Return the DELTA, IDX, PFN, and DELTA2 values for the PTRMEM_CST
5740 ??? There is no consistency as to the types returned for the above
5741 values. Some code acts as if it were a sizetype and some as if it were
5742 integer_type_node. */
5745 expand_ptrmemfunc_cst (tree cst, tree *delta, tree *pfn)
5747 tree type = TREE_TYPE (cst);
5748 tree fn = PTRMEM_CST_MEMBER (cst);
5749 tree ptr_class, fn_class;
5751 gcc_assert (TREE_CODE (fn) == FUNCTION_DECL);
5753 /* The class that the function belongs to. */
5754 fn_class = DECL_CONTEXT (fn);
5756 /* The class that we're creating a pointer to member of. */
5757 ptr_class = TYPE_PTRMEMFUNC_OBJECT_TYPE (type);
5759 /* First, calculate the adjustment to the function's class. */
5760 *delta = get_delta_difference (fn_class, ptr_class, /*force=*/0,
5763 if (!DECL_VIRTUAL_P (fn))
5764 *pfn = convert (TYPE_PTRMEMFUNC_FN_TYPE (type), build_addr_func (fn));
5767 /* If we're dealing with a virtual function, we have to adjust 'this'
5768 again, to point to the base which provides the vtable entry for
5769 fn; the call will do the opposite adjustment. */
5770 tree orig_class = DECL_CONTEXT (fn);
5771 tree binfo = binfo_or_else (orig_class, fn_class);
5772 *delta = build2 (PLUS_EXPR, TREE_TYPE (*delta),
5773 *delta, BINFO_OFFSET (binfo));
5774 *delta = fold_if_not_in_template (*delta);
5776 /* We set PFN to the vtable offset at which the function can be
5777 found, plus one (unless ptrmemfunc_vbit_in_delta, in which
5778 case delta is shifted left, and then incremented). */
5779 *pfn = DECL_VINDEX (fn);
5780 *pfn = build2 (MULT_EXPR, integer_type_node, *pfn,
5781 TYPE_SIZE_UNIT (vtable_entry_type));
5782 *pfn = fold_if_not_in_template (*pfn);
5784 switch (TARGET_PTRMEMFUNC_VBIT_LOCATION)
5786 case ptrmemfunc_vbit_in_pfn:
5787 *pfn = build2 (PLUS_EXPR, integer_type_node, *pfn,
5789 *pfn = fold_if_not_in_template (*pfn);
5792 case ptrmemfunc_vbit_in_delta:
5793 *delta = build2 (LSHIFT_EXPR, TREE_TYPE (*delta),
5794 *delta, integer_one_node);
5795 *delta = fold_if_not_in_template (*delta);
5796 *delta = build2 (PLUS_EXPR, TREE_TYPE (*delta),
5797 *delta, integer_one_node);
5798 *delta = fold_if_not_in_template (*delta);
5805 *pfn = build_nop (TYPE_PTRMEMFUNC_FN_TYPE (type), *pfn);
5806 *pfn = fold_if_not_in_template (*pfn);
5810 /* Return an expression for PFN from the pointer-to-member function
5814 pfn_from_ptrmemfunc (tree t)
5816 if (TREE_CODE (t) == PTRMEM_CST)
5821 expand_ptrmemfunc_cst (t, &delta, &pfn);
5826 return build_ptrmemfunc_access_expr (t, pfn_identifier);
5829 /* Convert value RHS to type TYPE as preparation for an assignment to
5830 an lvalue of type TYPE. ERRTYPE is a string to use in error
5831 messages: "assignment", "return", etc. If FNDECL is non-NULL, we
5832 are doing the conversion in order to pass the PARMNUMth argument of
5836 convert_for_assignment (tree type, tree rhs,
5837 const char *errtype, tree fndecl, int parmnum)
5840 enum tree_code coder;
5842 /* Strip NON_LVALUE_EXPRs since we aren't using as an lvalue. */
5843 if (TREE_CODE (rhs) == NON_LVALUE_EXPR)
5844 rhs = TREE_OPERAND (rhs, 0);
5846 rhstype = TREE_TYPE (rhs);
5847 coder = TREE_CODE (rhstype);
5849 if (TREE_CODE (type) == VECTOR_TYPE && coder == VECTOR_TYPE
5850 && vector_types_convertible_p (type, rhstype))
5851 return convert (type, rhs);
5853 if (rhs == error_mark_node || rhstype == error_mark_node)
5854 return error_mark_node;
5855 if (TREE_CODE (rhs) == TREE_LIST && TREE_VALUE (rhs) == error_mark_node)
5856 return error_mark_node;
5858 /* The RHS of an assignment cannot have void type. */
5859 if (coder == VOID_TYPE)
5861 error ("void value not ignored as it ought to be");
5862 return error_mark_node;
5865 /* Simplify the RHS if possible. */
5866 if (TREE_CODE (rhs) == CONST_DECL)
5867 rhs = DECL_INITIAL (rhs);
5869 if (c_dialect_objc ())
5872 tree rname = fndecl;
5874 if (!strcmp (errtype, "assignment"))
5876 else if (!strcmp (errtype, "initialization"))
5880 tree selector = objc_message_selector ();
5884 if (selector && parmno > 1)
5891 if (objc_compare_types (type, rhstype, parmno, rname))
5892 return convert (type, rhs);
5897 The expression is implicitly converted (clause _conv_) to the
5898 cv-unqualified type of the left operand.
5900 We allow bad conversions here because by the time we get to this point
5901 we are committed to doing the conversion. If we end up doing a bad
5902 conversion, convert_like will complain. */
5903 if (!can_convert_arg_bad (type, rhstype, rhs))
5905 /* When -Wno-pmf-conversions is use, we just silently allow
5906 conversions from pointers-to-members to plain pointers. If
5907 the conversion doesn't work, cp_convert will complain. */
5909 && TYPE_PTR_P (type)
5910 && TYPE_PTRMEMFUNC_P (rhstype))
5911 rhs = cp_convert (strip_top_quals (type), rhs);
5914 /* If the right-hand side has unknown type, then it is an
5915 overloaded function. Call instantiate_type to get error
5917 if (rhstype == unknown_type_node)
5918 instantiate_type (type, rhs, tf_error | tf_warning);
5920 error ("cannot convert %qT to %qT for argument %qP to %qD",
5921 rhstype, type, parmnum, fndecl);
5923 error ("cannot convert %qT to %qT in %s", rhstype, type, errtype);
5924 return error_mark_node;
5927 return perform_implicit_conversion (strip_top_quals (type), rhs);
5930 /* Convert RHS to be of type TYPE.
5931 If EXP is nonzero, it is the target of the initialization.
5932 ERRTYPE is a string to use in error messages.
5934 Two major differences between the behavior of
5935 `convert_for_assignment' and `convert_for_initialization'
5936 are that references are bashed in the former, while
5937 copied in the latter, and aggregates are assigned in
5938 the former (operator=) while initialized in the
5941 If using constructor make sure no conversion operator exists, if one does
5942 exist, an ambiguity exists.
5944 If flags doesn't include LOOKUP_COMPLAIN, don't complain about anything. */
5947 convert_for_initialization (tree exp, tree type, tree rhs, int flags,
5948 const char *errtype, tree fndecl, int parmnum)
5950 enum tree_code codel = TREE_CODE (type);
5952 enum tree_code coder;
5954 /* build_c_cast puts on a NOP_EXPR to make the result not an lvalue.
5955 Strip such NOP_EXPRs, since RHS is used in non-lvalue context. */
5956 if (TREE_CODE (rhs) == NOP_EXPR
5957 && TREE_TYPE (rhs) == TREE_TYPE (TREE_OPERAND (rhs, 0))
5958 && codel != REFERENCE_TYPE)
5959 rhs = TREE_OPERAND (rhs, 0);
5961 if (rhs == error_mark_node
5962 || (TREE_CODE (rhs) == TREE_LIST && TREE_VALUE (rhs) == error_mark_node))
5963 return error_mark_node;
5965 if ((TREE_CODE (TREE_TYPE (rhs)) == ARRAY_TYPE
5966 && TREE_CODE (type) != ARRAY_TYPE
5967 && (TREE_CODE (type) != REFERENCE_TYPE
5968 || TREE_CODE (TREE_TYPE (type)) != ARRAY_TYPE))
5969 || (TREE_CODE (TREE_TYPE (rhs)) == FUNCTION_TYPE
5970 && (TREE_CODE (type) != REFERENCE_TYPE
5971 || TREE_CODE (TREE_TYPE (type)) != FUNCTION_TYPE))
5972 || TREE_CODE (TREE_TYPE (rhs)) == METHOD_TYPE)
5973 rhs = decay_conversion (rhs);
5975 rhstype = TREE_TYPE (rhs);
5976 coder = TREE_CODE (rhstype);
5978 if (coder == ERROR_MARK)
5979 return error_mark_node;
5981 /* We accept references to incomplete types, so we can
5982 return here before checking if RHS is of complete type. */
5984 if (codel == REFERENCE_TYPE)
5986 /* This should eventually happen in convert_arguments. */
5987 int savew = 0, savee = 0;
5990 savew = warningcount, savee = errorcount;
5991 rhs = initialize_reference (type, rhs, /*decl=*/NULL_TREE,
5995 if (warningcount > savew)
5996 cp_warning_at ("in passing argument %P of %q+D", parmnum, fndecl);
5997 else if (errorcount > savee)
5998 cp_error_at ("in passing argument %P of %q+D", parmnum, fndecl);
6004 exp = require_complete_type (exp);
6005 if (exp == error_mark_node)
6006 return error_mark_node;
6008 rhstype = non_reference (rhstype);
6010 type = complete_type (type);
6012 if (IS_AGGR_TYPE (type))
6013 return ocp_convert (type, rhs, CONV_IMPLICIT|CONV_FORCE_TEMP, flags);
6015 return convert_for_assignment (type, rhs, errtype, fndecl, parmnum);
6018 /* If RETVAL is the address of, or a reference to, a local variable or
6019 temporary give an appropriate warning. */
6022 maybe_warn_about_returning_address_of_local (tree retval)
6024 tree valtype = TREE_TYPE (DECL_RESULT (current_function_decl));
6025 tree whats_returned = retval;
6029 if (TREE_CODE (whats_returned) == COMPOUND_EXPR)
6030 whats_returned = TREE_OPERAND (whats_returned, 1);
6031 else if (TREE_CODE (whats_returned) == CONVERT_EXPR
6032 || TREE_CODE (whats_returned) == NON_LVALUE_EXPR
6033 || TREE_CODE (whats_returned) == NOP_EXPR)
6034 whats_returned = TREE_OPERAND (whats_returned, 0);
6039 if (TREE_CODE (whats_returned) != ADDR_EXPR)
6041 whats_returned = TREE_OPERAND (whats_returned, 0);
6043 if (TREE_CODE (valtype) == REFERENCE_TYPE)
6045 if (TREE_CODE (whats_returned) == AGGR_INIT_EXPR
6046 || TREE_CODE (whats_returned) == TARGET_EXPR)
6048 warning (0, "returning reference to temporary");
6051 if (TREE_CODE (whats_returned) == VAR_DECL
6052 && DECL_NAME (whats_returned)
6053 && TEMP_NAME_P (DECL_NAME (whats_returned)))
6055 warning (0, "reference to non-lvalue returned");
6060 if (DECL_P (whats_returned)
6061 && DECL_NAME (whats_returned)
6062 && DECL_FUNCTION_SCOPE_P (whats_returned)
6063 && !(TREE_STATIC (whats_returned)
6064 || TREE_PUBLIC (whats_returned)))
6066 if (TREE_CODE (valtype) == REFERENCE_TYPE)
6067 cp_warning_at ("reference to local variable %qD returned",
6070 cp_warning_at ("address of local variable %qD returned",
6076 /* Check that returning RETVAL from the current function is valid.
6077 Return an expression explicitly showing all conversions required to
6078 change RETVAL into the function return type, and to assign it to
6079 the DECL_RESULT for the function. */
6082 check_return_expr (tree retval)
6085 /* The type actually returned by the function, after any
6088 int fn_returns_value_p;
6090 /* A `volatile' function is one that isn't supposed to return, ever.
6091 (This is a G++ extension, used to get better code for functions
6092 that call the `volatile' function.) */
6093 if (TREE_THIS_VOLATILE (current_function_decl))
6094 warning (0, "function declared %<noreturn%> has a %<return%> statement");
6096 /* Check for various simple errors. */
6097 if (DECL_DESTRUCTOR_P (current_function_decl))
6100 error ("returning a value from a destructor");
6103 else if (DECL_CONSTRUCTOR_P (current_function_decl))
6105 if (in_function_try_handler)
6106 /* If a return statement appears in a handler of the
6107 function-try-block of a constructor, the program is ill-formed. */
6108 error ("cannot return from a handler of a function-try-block of a constructor");
6110 /* You can't return a value from a constructor. */
6111 error ("returning a value from a constructor");
6115 if (processing_template_decl)
6117 current_function_returns_value = 1;
6121 /* When no explicit return-value is given in a function with a named
6122 return value, the named return value is used. */
6123 result = DECL_RESULT (current_function_decl);
6124 valtype = TREE_TYPE (result);
6125 gcc_assert (valtype != NULL_TREE);
6126 fn_returns_value_p = !VOID_TYPE_P (valtype);
6127 if (!retval && DECL_NAME (result) && fn_returns_value_p)
6130 /* Check for a return statement with no return value in a function
6131 that's supposed to return a value. */
6132 if (!retval && fn_returns_value_p)
6134 pedwarn ("return-statement with no value, in function returning %qT",
6136 /* Clear this, so finish_function won't say that we reach the
6137 end of a non-void function (which we don't, we gave a
6139 current_function_returns_null = 0;
6141 /* Check for a return statement with a value in a function that
6142 isn't supposed to return a value. */
6143 else if (retval && !fn_returns_value_p)
6145 if (VOID_TYPE_P (TREE_TYPE (retval)))
6146 /* You can return a `void' value from a function of `void'
6147 type. In that case, we have to evaluate the expression for
6148 its side-effects. */
6149 finish_expr_stmt (retval);
6151 pedwarn ("return-statement with a value, in function "
6152 "returning 'void'");
6154 current_function_returns_null = 1;
6156 /* There's really no value to return, after all. */
6160 /* Remember that this function can sometimes return without a
6162 current_function_returns_null = 1;
6164 /* Remember that this function did return a value. */
6165 current_function_returns_value = 1;
6167 /* Check for erroneous operands -- but after giving ourselves a
6168 chance to provide an error about returning a value from a void
6170 if (error_operand_p (retval))
6172 current_function_return_value = error_mark_node;
6173 return error_mark_node;
6176 /* Only operator new(...) throw(), can return NULL [expr.new/13]. */
6177 if ((DECL_OVERLOADED_OPERATOR_P (current_function_decl) == NEW_EXPR
6178 || DECL_OVERLOADED_OPERATOR_P (current_function_decl) == VEC_NEW_EXPR)
6179 && !TYPE_NOTHROW_P (TREE_TYPE (current_function_decl))
6181 && null_ptr_cst_p (retval))
6182 warning (0, "%<operator new%> must not return NULL unless it is "
6183 "declared %<throw()%> (or -fcheck-new is in effect)");
6185 /* Effective C++ rule 15. See also start_function. */
6187 && DECL_NAME (current_function_decl) == ansi_assopname(NOP_EXPR))
6191 /* The function return type must be a reference to the current
6193 if (TREE_CODE (valtype) == REFERENCE_TYPE
6194 && same_type_ignoring_top_level_qualifiers_p
6195 (TREE_TYPE (valtype), TREE_TYPE (current_class_ref)))
6197 /* Returning '*this' is obviously OK. */
6198 if (retval == current_class_ref)
6200 /* If we are calling a function whose return type is the same of
6201 the current class reference, it is ok. */
6202 else if (TREE_CODE (retval) == INDIRECT_REF
6203 && TREE_CODE (TREE_OPERAND (retval, 0)) == CALL_EXPR)
6208 warning (0, "%<operator=%> should return a reference to %<*this%>");
6211 /* The fabled Named Return Value optimization, as per [class.copy]/15:
6213 [...] For a function with a class return type, if the expression
6214 in the return statement is the name of a local object, and the cv-
6215 unqualified type of the local object is the same as the function
6216 return type, an implementation is permitted to omit creating the tem-
6217 porary object to hold the function return value [...]
6219 So, if this is a value-returning function that always returns the same
6220 local variable, remember it.
6222 It might be nice to be more flexible, and choose the first suitable
6223 variable even if the function sometimes returns something else, but
6224 then we run the risk of clobbering the variable we chose if the other
6225 returned expression uses the chosen variable somehow. And people expect
6226 this restriction, anyway. (jason 2000-11-19)
6228 See finish_function and finalize_nrv for the rest of this optimization. */
6230 if (fn_returns_value_p && flag_elide_constructors)
6232 if (retval != NULL_TREE
6233 && (current_function_return_value == NULL_TREE
6234 || current_function_return_value == retval)
6235 && TREE_CODE (retval) == VAR_DECL
6236 && DECL_CONTEXT (retval) == current_function_decl
6237 && ! TREE_STATIC (retval)
6238 && (DECL_ALIGN (retval)
6239 >= DECL_ALIGN (DECL_RESULT (current_function_decl)))
6240 && same_type_p ((TYPE_MAIN_VARIANT
6241 (TREE_TYPE (retval))),
6243 (TREE_TYPE (TREE_TYPE (current_function_decl))))))
6244 current_function_return_value = retval;
6246 current_function_return_value = error_mark_node;
6249 /* We don't need to do any conversions when there's nothing being
6254 /* Do any required conversions. */
6255 if (retval == result || DECL_CONSTRUCTOR_P (current_function_decl))
6256 /* No conversions are required. */
6260 /* The type the function is declared to return. */
6261 tree functype = TREE_TYPE (TREE_TYPE (current_function_decl));
6263 /* First convert the value to the function's return type, then
6264 to the type of return value's location to handle the
6265 case that functype is smaller than the valtype. */
6266 retval = convert_for_initialization
6267 (NULL_TREE, functype, retval, LOOKUP_NORMAL|LOOKUP_ONLYCONVERTING,
6268 "return", NULL_TREE, 0);
6269 retval = convert (valtype, retval);
6271 /* If the conversion failed, treat this just like `return;'. */
6272 if (retval == error_mark_node)
6274 /* We can't initialize a register from a AGGR_INIT_EXPR. */
6275 else if (! current_function_returns_struct
6276 && TREE_CODE (retval) == TARGET_EXPR
6277 && TREE_CODE (TREE_OPERAND (retval, 1)) == AGGR_INIT_EXPR)
6278 retval = build2 (COMPOUND_EXPR, TREE_TYPE (retval), retval,
6279 TREE_OPERAND (retval, 0));
6281 maybe_warn_about_returning_address_of_local (retval);
6284 /* Actually copy the value returned into the appropriate location. */
6285 if (retval && retval != result)
6286 retval = build2 (INIT_EXPR, TREE_TYPE (result), result, retval);
6292 /* Returns nonzero if the pointer-type FROM can be converted to the
6293 pointer-type TO via a qualification conversion. If CONSTP is -1,
6294 then we return nonzero if the pointers are similar, and the
6295 cv-qualification signature of FROM is a proper subset of that of TO.
6297 If CONSTP is positive, then all outer pointers have been
6301 comp_ptr_ttypes_real (tree to, tree from, int constp)
6303 bool to_more_cv_qualified = false;
6305 for (; ; to = TREE_TYPE (to), from = TREE_TYPE (from))
6307 if (TREE_CODE (to) != TREE_CODE (from))
6310 if (TREE_CODE (from) == OFFSET_TYPE
6311 && !same_type_p (TYPE_OFFSET_BASETYPE (from),
6312 TYPE_OFFSET_BASETYPE (to)))
6315 /* Const and volatile mean something different for function types,
6316 so the usual checks are not appropriate. */
6317 if (TREE_CODE (to) != FUNCTION_TYPE && TREE_CODE (to) != METHOD_TYPE)
6319 /* In Objective-C++, some types may have been 'volatilized' by
6320 the compiler for EH; when comparing them here, the volatile
6321 qualification must be ignored. */
6322 bool objc_quals_match = objc_type_quals_match (to, from);
6324 if (!at_least_as_qualified_p (to, from) && !objc_quals_match)
6327 if (!at_least_as_qualified_p (from, to) && !objc_quals_match)
6331 to_more_cv_qualified = true;
6335 constp &= TYPE_READONLY (to);
6338 if (TREE_CODE (to) != POINTER_TYPE && !TYPE_PTRMEM_P (to))
6339 return ((constp >= 0 || to_more_cv_qualified)
6340 && same_type_ignoring_top_level_qualifiers_p (to, from));
6344 /* When comparing, say, char ** to char const **, this function takes
6345 the 'char *' and 'char const *'. Do not pass non-pointer/reference
6346 types to this function. */
6349 comp_ptr_ttypes (tree to, tree from)
6351 return comp_ptr_ttypes_real (to, from, 1);
6354 /* Returns 1 if to and from are (possibly multi-level) pointers to the same
6355 type or inheritance-related types, regardless of cv-quals. */
6358 ptr_reasonably_similar (tree to, tree from)
6360 for (; ; to = TREE_TYPE (to), from = TREE_TYPE (from))
6362 /* Any target type is similar enough to void. */
6363 if (TREE_CODE (to) == VOID_TYPE
6364 || TREE_CODE (from) == VOID_TYPE)
6367 if (TREE_CODE (to) != TREE_CODE (from))
6370 if (TREE_CODE (from) == OFFSET_TYPE
6371 && comptypes (TYPE_OFFSET_BASETYPE (to),
6372 TYPE_OFFSET_BASETYPE (from),
6373 COMPARE_BASE | COMPARE_DERIVED))
6376 if (TREE_CODE (to) == VECTOR_TYPE
6377 && vector_types_convertible_p (to, from))
6380 if (TREE_CODE (to) == INTEGER_TYPE
6381 && TYPE_PRECISION (to) == TYPE_PRECISION (from))
6384 if (TREE_CODE (to) == FUNCTION_TYPE)
6387 if (TREE_CODE (to) != POINTER_TYPE)
6389 (TYPE_MAIN_VARIANT (to), TYPE_MAIN_VARIANT (from),
6390 COMPARE_BASE | COMPARE_DERIVED);
6394 /* Like comp_ptr_ttypes, for const_cast. */
6397 comp_ptr_ttypes_const (tree to, tree from)
6399 for (; ; to = TREE_TYPE (to), from = TREE_TYPE (from))
6401 if (TREE_CODE (to) != TREE_CODE (from))
6404 if (TREE_CODE (from) == OFFSET_TYPE
6405 && same_type_p (TYPE_OFFSET_BASETYPE (from),
6406 TYPE_OFFSET_BASETYPE (to)))
6409 if (TREE_CODE (to) != POINTER_TYPE)
6410 return same_type_ignoring_top_level_qualifiers_p (to, from);
6414 /* Returns the type qualifiers for this type, including the qualifiers on the
6415 elements for an array type. */
6418 cp_type_quals (tree type)
6420 type = strip_array_types (type);
6421 if (type == error_mark_node)
6422 return TYPE_UNQUALIFIED;
6423 return TYPE_QUALS (type);
6426 /* Returns nonzero if the TYPE contains a mutable member. */
6429 cp_has_mutable_p (tree type)
6431 type = strip_array_types (type);
6433 return CLASS_TYPE_P (type) && CLASSTYPE_HAS_MUTABLE (type);
6436 /* Apply the TYPE_QUALS to the new DECL. */
6438 cp_apply_type_quals_to_decl (int type_quals, tree decl)
6440 tree type = TREE_TYPE (decl);
6442 if (type == error_mark_node)
6445 if (TREE_CODE (type) == FUNCTION_TYPE
6446 && type_quals != TYPE_UNQUALIFIED)
6448 /* This was an error in C++98 (cv-qualifiers cannot be added to
6449 a function type), but DR 295 makes the code well-formed by
6450 dropping the extra qualifiers. */
6453 tree bad_type = build_qualified_type (type, type_quals);
6454 pedwarn ("ignoring %qV qualifiers added to function type %qT",
6458 TREE_TYPE (decl) = TYPE_MAIN_VARIANT (type);
6462 /* Avoid setting TREE_READONLY incorrectly. */
6463 if (/* If the object has a constructor, the constructor may modify
6465 TYPE_NEEDS_CONSTRUCTING (type)
6466 /* If the type isn't complete, we don't know yet if it will need
6468 || !COMPLETE_TYPE_P (type)
6469 /* If the type has a mutable component, that component might be
6471 || TYPE_HAS_MUTABLE_P (type))
6472 type_quals &= ~TYPE_QUAL_CONST;
6474 c_apply_type_quals_to_decl (type_quals, decl);
6477 /* Subroutine of casts_away_constness. Make T1 and T2 point at
6478 exemplar types such that casting T1 to T2 is casting away constness
6479 if and only if there is no implicit conversion from T1 to T2. */
6482 casts_away_constness_r (tree *t1, tree *t2)
6487 /* [expr.const.cast]
6489 For multi-level pointer to members and multi-level mixed pointers
6490 and pointers to members (conv.qual), the "member" aspect of a
6491 pointer to member level is ignored when determining if a const
6492 cv-qualifier has been cast away. */
6493 /* [expr.const.cast]
6495 For two pointer types:
6497 X1 is T1cv1,1 * ... cv1,N * where T1 is not a pointer type
6498 X2 is T2cv2,1 * ... cv2,M * where T2 is not a pointer type
6501 casting from X1 to X2 casts away constness if, for a non-pointer
6502 type T there does not exist an implicit conversion (clause
6505 Tcv1,(N-K+1) * cv1,(N-K+2) * ... cv1,N *
6509 Tcv2,(M-K+1) * cv2,(M-K+2) * ... cv2,M *. */
6510 if ((!TYPE_PTR_P (*t1) && !TYPE_PTRMEM_P (*t1))
6511 || (!TYPE_PTR_P (*t2) && !TYPE_PTRMEM_P (*t2)))
6513 *t1 = cp_build_qualified_type (void_type_node,
6514 cp_type_quals (*t1));
6515 *t2 = cp_build_qualified_type (void_type_node,
6516 cp_type_quals (*t2));
6520 quals1 = cp_type_quals (*t1);
6521 quals2 = cp_type_quals (*t2);
6523 if (TYPE_PTRMEM_P (*t1))
6524 *t1 = TYPE_PTRMEM_POINTED_TO_TYPE (*t1);
6526 *t1 = TREE_TYPE (*t1);
6527 if (TYPE_PTRMEM_P (*t2))
6528 *t2 = TYPE_PTRMEM_POINTED_TO_TYPE (*t2);
6530 *t2 = TREE_TYPE (*t2);
6532 casts_away_constness_r (t1, t2);
6533 *t1 = build_pointer_type (*t1);
6534 *t2 = build_pointer_type (*t2);
6535 *t1 = cp_build_qualified_type (*t1, quals1);
6536 *t2 = cp_build_qualified_type (*t2, quals2);
6539 /* Returns nonzero if casting from TYPE1 to TYPE2 casts away
6543 casts_away_constness (tree t1, tree t2)
6545 if (TREE_CODE (t2) == REFERENCE_TYPE)
6547 /* [expr.const.cast]
6549 Casting from an lvalue of type T1 to an lvalue of type T2
6550 using a reference cast casts away constness if a cast from an
6551 rvalue of type "pointer to T1" to the type "pointer to T2"
6552 casts away constness. */
6553 t1 = (TREE_CODE (t1) == REFERENCE_TYPE ? TREE_TYPE (t1) : t1);
6554 return casts_away_constness (build_pointer_type (t1),
6555 build_pointer_type (TREE_TYPE (t2)));
6558 if (TYPE_PTRMEM_P (t1) && TYPE_PTRMEM_P (t2))
6559 /* [expr.const.cast]
6561 Casting from an rvalue of type "pointer to data member of X
6562 of type T1" to the type "pointer to data member of Y of type
6563 T2" casts away constness if a cast from an rvalue of type
6564 "pointer to T1" to the type "pointer to T2" casts away
6566 return casts_away_constness
6567 (build_pointer_type (TYPE_PTRMEM_POINTED_TO_TYPE (t1)),
6568 build_pointer_type (TYPE_PTRMEM_POINTED_TO_TYPE (t2)));
6570 /* Casting away constness is only something that makes sense for
6571 pointer or reference types. */
6572 if (TREE_CODE (t1) != POINTER_TYPE
6573 || TREE_CODE (t2) != POINTER_TYPE)
6576 /* Top-level qualifiers don't matter. */
6577 t1 = TYPE_MAIN_VARIANT (t1);
6578 t2 = TYPE_MAIN_VARIANT (t2);
6579 casts_away_constness_r (&t1, &t2);
6580 if (!can_convert (t2, t1))
6586 /* If T is a REFERENCE_TYPE return the type to which T refers.
6587 Otherwise, return T itself. */
6590 non_reference (tree t)
6592 if (TREE_CODE (t) == REFERENCE_TYPE)
6598 /* Return nonzero if REF is an lvalue valid for this language;
6599 otherwise, print an error message and return zero. USE says
6600 how the lvalue is being used and so selects the error message. */
6603 lvalue_or_else (tree ref, enum lvalue_use use)
6605 int win = lvalue_p (ref);