1 /* Build expressions with type checking for C++ compiler.
2 Copyright (C) 1987, 1988, 1989, 1992, 1993, 1994, 1995, 1996, 1997, 1998,
3 1999, 2000, 2001, 2002, 2003, 2004 Free Software Foundation, Inc.
4 Hacked by Michael Tiemann (tiemann@cygnus.com)
6 This file is part of GCC.
8 GCC is free software; you can redistribute it and/or modify
9 it under the terms of the GNU General Public License as published by
10 the Free Software Foundation; either version 2, or (at your option)
13 GCC is distributed in the hope that it will be useful,
14 but WITHOUT ANY WARRANTY; without even the implied warranty of
15 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 GNU General Public License for more details.
18 You should have received a copy of the GNU General Public License
19 along with GCC; see the file COPYING. If not, write to
20 the Free Software Foundation, 59 Temple Place - Suite 330,
21 Boston, MA 02111-1307, USA. */
24 /* This file is part of the C++ front end.
25 It contains routines to build C++ expressions given their operands,
26 including computing the types of the result, C and C++ specific error
27 checks, and some optimization. */
31 #include "coretypes.h"
41 #include "diagnostic.h"
45 static tree convert_for_assignment (tree, tree, const char *, tree, int);
46 static tree cp_pointer_int_sum (enum tree_code, tree, tree);
47 static tree rationalize_conditional_expr (enum tree_code, tree);
48 static int comp_ptr_ttypes_real (tree, tree, int);
49 static int comp_ptr_ttypes_const (tree, tree);
50 static bool comp_except_types (tree, tree, bool);
51 static bool comp_array_types (tree, tree, bool);
52 static tree common_base_type (tree, tree);
53 static tree pointer_diff (tree, tree, tree);
54 static tree get_delta_difference (tree, tree, int);
55 static void casts_away_constness_r (tree *, tree *);
56 static bool casts_away_constness (tree, tree);
57 static void maybe_warn_about_returning_address_of_local (tree);
58 static tree lookup_destructor (tree, tree, tree);
60 /* Return the target type of TYPE, which means return T for:
61 T*, T&, T[], T (...), and otherwise, just T. */
64 target_type (tree type)
66 type = non_reference (type);
67 while (TREE_CODE (type) == POINTER_TYPE
68 || TREE_CODE (type) == ARRAY_TYPE
69 || TREE_CODE (type) == FUNCTION_TYPE
70 || TREE_CODE (type) == METHOD_TYPE
71 || TYPE_PTRMEM_P (type))
72 type = TREE_TYPE (type);
76 /* Do `exp = require_complete_type (exp);' to make sure exp
77 does not have an incomplete type. (That includes void types.)
78 Returns the error_mark_node if the VALUE does not have
79 complete type when this function returns. */
82 require_complete_type (tree value)
86 if (processing_template_decl || value == error_mark_node)
89 if (TREE_CODE (value) == OVERLOAD)
90 type = unknown_type_node;
92 type = TREE_TYPE (value);
94 if (type == error_mark_node)
95 return error_mark_node;
97 /* First, detect a valid value with a complete type. */
98 if (COMPLETE_TYPE_P (type))
101 if (complete_type_or_else (type, value))
104 return error_mark_node;
107 /* Try to complete TYPE, if it is incomplete. For example, if TYPE is
108 a template instantiation, do the instantiation. Returns TYPE,
109 whether or not it could be completed, unless something goes
110 horribly wrong, in which case the error_mark_node is returned. */
113 complete_type (tree type)
115 if (type == NULL_TREE)
116 /* Rather than crash, we return something sure to cause an error
118 return error_mark_node;
120 if (type == error_mark_node || COMPLETE_TYPE_P (type))
122 else if (TREE_CODE (type) == ARRAY_TYPE && TYPE_DOMAIN (type))
124 tree t = complete_type (TREE_TYPE (type));
125 if (COMPLETE_TYPE_P (t) && !dependent_type_p (type))
127 TYPE_NEEDS_CONSTRUCTING (type)
128 = TYPE_NEEDS_CONSTRUCTING (TYPE_MAIN_VARIANT (t));
129 TYPE_HAS_NONTRIVIAL_DESTRUCTOR (type)
130 = TYPE_HAS_NONTRIVIAL_DESTRUCTOR (TYPE_MAIN_VARIANT (t));
132 else if (CLASS_TYPE_P (type) && CLASSTYPE_TEMPLATE_INSTANTIATION (type))
133 instantiate_class_template (TYPE_MAIN_VARIANT (type));
138 /* Like complete_type, but issue an error if the TYPE cannot be completed.
139 VALUE is used for informative diagnostics. DIAG_TYPE indicates the type
140 of diagnostic: 0 for an error, 1 for a warning, 2 for a pedwarn.
141 Returns NULL_TREE if the type cannot be made complete. */
144 complete_type_or_diagnostic (tree type, tree value, int diag_type)
146 type = complete_type (type);
147 if (type == error_mark_node)
148 /* We already issued an error. */
150 else if (!COMPLETE_TYPE_P (type))
152 cxx_incomplete_type_diagnostic (value, type, diag_type);
159 /* Return truthvalue of whether type of EXP is instantiated. */
162 type_unknown_p (tree exp)
164 return (TREE_CODE (exp) == TREE_LIST
165 || TREE_TYPE (exp) == unknown_type_node);
169 /* Return the common type of two parameter lists.
170 We assume that comptypes has already been done and returned 1;
171 if that isn't so, this may crash.
173 As an optimization, free the space we allocate if the parameter
174 lists are already common. */
177 commonparms (tree p1, tree p2)
179 tree oldargs = p1, newargs, n;
183 len = list_length (p1);
184 newargs = tree_last (p1);
186 if (newargs == void_list_node)
195 newargs = tree_cons (NULL_TREE, NULL_TREE, newargs);
200 p1 = TREE_CHAIN (p1), p2 = TREE_CHAIN (p2), n = TREE_CHAIN (n), i++)
202 if (TREE_PURPOSE (p1) && !TREE_PURPOSE (p2))
204 TREE_PURPOSE (n) = TREE_PURPOSE (p1);
207 else if (! TREE_PURPOSE (p1))
209 if (TREE_PURPOSE (p2))
211 TREE_PURPOSE (n) = TREE_PURPOSE (p2);
217 if (1 != simple_cst_equal (TREE_PURPOSE (p1), TREE_PURPOSE (p2)))
219 TREE_PURPOSE (n) = TREE_PURPOSE (p2);
221 if (TREE_VALUE (p1) != TREE_VALUE (p2))
224 TREE_VALUE (n) = merge_types (TREE_VALUE (p1), TREE_VALUE (p2));
227 TREE_VALUE (n) = TREE_VALUE (p1);
235 /* Given a type, perhaps copied for a typedef,
236 find the "original" version of it. */
238 original_type (tree t)
240 while (TYPE_NAME (t) != NULL_TREE)
242 tree x = TYPE_NAME (t);
243 if (TREE_CODE (x) != TYPE_DECL)
245 x = DECL_ORIGINAL_TYPE (x);
253 /* T1 and T2 are arithmetic or enumeration types. Return the type
254 that will result from the "usual arithmetic conversions" on T1 and
255 T2 as described in [expr]. */
258 type_after_usual_arithmetic_conversions (tree t1, tree t2)
260 enum tree_code code1 = TREE_CODE (t1);
261 enum tree_code code2 = TREE_CODE (t2);
264 /* FIXME: Attributes. */
265 my_friendly_assert (ARITHMETIC_TYPE_P (t1)
266 || TREE_CODE (t1) == COMPLEX_TYPE
267 || TREE_CODE (t1) == ENUMERAL_TYPE,
269 my_friendly_assert (ARITHMETIC_TYPE_P (t2)
270 || TREE_CODE (t2) == COMPLEX_TYPE
271 || TREE_CODE (t2) == ENUMERAL_TYPE,
274 /* In what follows, we slightly generalize the rules given in [expr] so
275 as to deal with `long long' and `complex'. First, merge the
277 attributes = (*targetm.merge_type_attributes) (t1, t2);
279 /* If one type is complex, form the common type of the non-complex
280 components, then make that complex. Use T1 or T2 if it is the
282 if (code1 == COMPLEX_TYPE || code2 == COMPLEX_TYPE)
284 tree subtype1 = code1 == COMPLEX_TYPE ? TREE_TYPE (t1) : t1;
285 tree subtype2 = code2 == COMPLEX_TYPE ? TREE_TYPE (t2) : t2;
287 = type_after_usual_arithmetic_conversions (subtype1, subtype2);
289 if (code1 == COMPLEX_TYPE && TREE_TYPE (t1) == subtype)
290 return build_type_attribute_variant (t1, attributes);
291 else if (code2 == COMPLEX_TYPE && TREE_TYPE (t2) == subtype)
292 return build_type_attribute_variant (t2, attributes);
294 return build_type_attribute_variant (build_complex_type (subtype),
298 /* If only one is real, use it as the result. */
299 if (code1 == REAL_TYPE && code2 != REAL_TYPE)
300 return build_type_attribute_variant (t1, attributes);
301 if (code2 == REAL_TYPE && code1 != REAL_TYPE)
302 return build_type_attribute_variant (t2, attributes);
304 /* Perform the integral promotions. */
305 if (code1 != REAL_TYPE)
307 t1 = type_promotes_to (t1);
308 t2 = type_promotes_to (t2);
311 /* Both real or both integers; use the one with greater precision. */
312 if (TYPE_PRECISION (t1) > TYPE_PRECISION (t2))
313 return build_type_attribute_variant (t1, attributes);
314 else if (TYPE_PRECISION (t2) > TYPE_PRECISION (t1))
315 return build_type_attribute_variant (t2, attributes);
317 /* The types are the same; no need to do anything fancy. */
318 if (TYPE_MAIN_VARIANT (t1) == TYPE_MAIN_VARIANT (t2))
319 return build_type_attribute_variant (t1, attributes);
321 if (code1 != REAL_TYPE)
323 /* If one is a sizetype, use it so size_binop doesn't blow up. */
324 if (TYPE_IS_SIZETYPE (t1) > TYPE_IS_SIZETYPE (t2))
325 return build_type_attribute_variant (t1, attributes);
326 if (TYPE_IS_SIZETYPE (t2) > TYPE_IS_SIZETYPE (t1))
327 return build_type_attribute_variant (t2, attributes);
329 /* If one is unsigned long long, then convert the other to unsigned
331 if (same_type_p (TYPE_MAIN_VARIANT (t1), long_long_unsigned_type_node)
332 || same_type_p (TYPE_MAIN_VARIANT (t2), long_long_unsigned_type_node))
333 return build_type_attribute_variant (long_long_unsigned_type_node,
335 /* If one is a long long, and the other is an unsigned long, and
336 long long can represent all the values of an unsigned long, then
337 convert to a long long. Otherwise, convert to an unsigned long
338 long. Otherwise, if either operand is long long, convert the
341 Since we're here, we know the TYPE_PRECISION is the same;
342 therefore converting to long long cannot represent all the values
343 of an unsigned long, so we choose unsigned long long in that
345 if (same_type_p (TYPE_MAIN_VARIANT (t1), long_long_integer_type_node)
346 || same_type_p (TYPE_MAIN_VARIANT (t2), long_long_integer_type_node))
348 tree t = ((TYPE_UNSIGNED (t1) || TYPE_UNSIGNED (t2))
349 ? long_long_unsigned_type_node
350 : long_long_integer_type_node);
351 return build_type_attribute_variant (t, attributes);
354 /* Go through the same procedure, but for longs. */
355 if (same_type_p (TYPE_MAIN_VARIANT (t1), long_unsigned_type_node)
356 || same_type_p (TYPE_MAIN_VARIANT (t2), long_unsigned_type_node))
357 return build_type_attribute_variant (long_unsigned_type_node,
359 if (same_type_p (TYPE_MAIN_VARIANT (t1), long_integer_type_node)
360 || same_type_p (TYPE_MAIN_VARIANT (t2), long_integer_type_node))
362 tree t = ((TYPE_UNSIGNED (t1) || TYPE_UNSIGNED (t2))
363 ? long_unsigned_type_node : long_integer_type_node);
364 return build_type_attribute_variant (t, attributes);
366 /* Otherwise prefer the unsigned one. */
367 if (TYPE_UNSIGNED (t1))
368 return build_type_attribute_variant (t1, attributes);
370 return build_type_attribute_variant (t2, attributes);
374 if (same_type_p (TYPE_MAIN_VARIANT (t1), long_double_type_node)
375 || same_type_p (TYPE_MAIN_VARIANT (t2), long_double_type_node))
376 return build_type_attribute_variant (long_double_type_node,
378 if (same_type_p (TYPE_MAIN_VARIANT (t1), double_type_node)
379 || same_type_p (TYPE_MAIN_VARIANT (t2), double_type_node))
380 return build_type_attribute_variant (double_type_node,
382 if (same_type_p (TYPE_MAIN_VARIANT (t1), float_type_node)
383 || same_type_p (TYPE_MAIN_VARIANT (t2), float_type_node))
384 return build_type_attribute_variant (float_type_node,
387 /* Two floating-point types whose TYPE_MAIN_VARIANTs are none of
388 the standard C++ floating-point types. Logic earlier in this
389 function has already eliminated the possibility that
390 TYPE_PRECISION (t2) != TYPE_PRECISION (t1), so there's no
391 compelling reason to choose one or the other. */
392 return build_type_attribute_variant (t1, attributes);
396 /* Subroutine of composite_pointer_type to implement the recursive
397 case. See that function for documentation fo the parameters. */
400 composite_pointer_type_r (tree t1, tree t2, const char* location)
407 /* Determine the types pointed to by T1 and T2. */
408 if (TREE_CODE (t1) == POINTER_TYPE)
410 pointee1 = TREE_TYPE (t1);
411 pointee2 = TREE_TYPE (t2);
415 pointee1 = TYPE_PTRMEM_POINTED_TO_TYPE (t1);
416 pointee2 = TYPE_PTRMEM_POINTED_TO_TYPE (t2);
421 Otherwise, the composite pointer type is a pointer type
422 similar (_conv.qual_) to the type of one of the operands,
423 with a cv-qualification signature (_conv.qual_) that is the
424 union of the cv-qualification signatures of the operand
426 if (same_type_ignoring_top_level_qualifiers_p (pointee1, pointee2))
427 result_type = pointee1;
428 else if ((TREE_CODE (pointee1) == POINTER_TYPE
429 && TREE_CODE (pointee2) == POINTER_TYPE)
430 || (TYPE_PTR_TO_MEMBER_P (pointee1)
431 && TYPE_PTR_TO_MEMBER_P (pointee2)))
432 result_type = composite_pointer_type_r (pointee1, pointee2, location);
435 pedwarn ("%s between distinct pointer types `%T' and `%T' "
438 result_type = void_type_node;
440 result_type = cp_build_qualified_type (result_type,
441 (cp_type_quals (pointee1)
442 | cp_type_quals (pointee2)));
443 /* If the original types were pointers to members, so is the
445 if (TYPE_PTR_TO_MEMBER_P (t1))
447 if (!same_type_p (TYPE_PTRMEM_CLASS_TYPE (t1),
448 TYPE_PTRMEM_CLASS_TYPE (t2)))
449 pedwarn ("%s between distinct pointer types `%T' and `%T' "
452 result_type = build_ptrmem_type (TYPE_PTRMEM_CLASS_TYPE (t1),
456 result_type = build_pointer_type (result_type);
458 /* Merge the attributes. */
459 attributes = (*targetm.merge_type_attributes) (t1, t2);
460 return build_type_attribute_variant (result_type, attributes);
463 /* Return the composite pointer type (see [expr.rel]) for T1 and T2.
464 ARG1 and ARG2 are the values with those types. The LOCATION is a
465 string describing the current location, in case an error occurs.
467 This routine also implements the computation of a common type for
468 pointers-to-members as per [expr.eq]. */
471 composite_pointer_type (tree t1, tree t2, tree arg1, tree arg2,
472 const char* location)
479 If one operand is a null pointer constant, the composite pointer
480 type is the type of the other operand. */
481 if (null_ptr_cst_p (arg1))
483 if (null_ptr_cst_p (arg2))
490 If one of the operands has type "pointer to cv1 void*", then
491 the other has type "pointer to cv2T", and the composite pointer
492 type is "pointer to cv12 void", where cv12 is the union of cv1
495 If either type is a pointer to void, make sure it is T1. */
496 if (TREE_CODE (t2) == POINTER_TYPE && VOID_TYPE_P (TREE_TYPE (t2)))
504 /* Now, if T1 is a pointer to void, merge the qualifiers. */
505 if (TREE_CODE (t1) == POINTER_TYPE && VOID_TYPE_P (TREE_TYPE (t1)))
510 if (pedantic && TYPE_PTRFN_P (t2))
511 pedwarn ("ISO C++ forbids %s between pointer of type `void *' and pointer-to-function", location);
513 = cp_build_qualified_type (void_type_node,
514 (cp_type_quals (TREE_TYPE (t1))
515 | cp_type_quals (TREE_TYPE (t2))));
516 result_type = build_pointer_type (result_type);
517 /* Merge the attributes. */
518 attributes = (*targetm.merge_type_attributes) (t1, t2);
519 return build_type_attribute_variant (result_type, attributes);
522 /* [expr.eq] permits the application of a pointer conversion to
523 bring the pointers to a common type. */
524 if (TREE_CODE (t1) == POINTER_TYPE && TREE_CODE (t2) == POINTER_TYPE
525 && CLASS_TYPE_P (TREE_TYPE (t1))
526 && CLASS_TYPE_P (TREE_TYPE (t2))
527 && !same_type_ignoring_top_level_qualifiers_p (TREE_TYPE (t1),
530 class1 = TREE_TYPE (t1);
531 class2 = TREE_TYPE (t2);
533 if (DERIVED_FROM_P (class1, class2))
534 t2 = (build_pointer_type
535 (cp_build_qualified_type (class1, TYPE_QUALS (class2))));
536 else if (DERIVED_FROM_P (class2, class1))
537 t1 = (build_pointer_type
538 (cp_build_qualified_type (class2, TYPE_QUALS (class1))));
541 error ("%s between distinct pointer types `%T' and `%T' "
542 "lacks a cast", location, t1, t2);
543 return error_mark_node;
546 /* [expr.eq] permits the application of a pointer-to-member
547 conversion to change the class type of one of the types. */
548 else if (TYPE_PTR_TO_MEMBER_P (t1)
549 && !same_type_p (TYPE_PTRMEM_CLASS_TYPE (t1),
550 TYPE_PTRMEM_CLASS_TYPE (t2)))
552 class1 = TYPE_PTRMEM_CLASS_TYPE (t1);
553 class2 = TYPE_PTRMEM_CLASS_TYPE (t2);
555 if (DERIVED_FROM_P (class1, class2))
556 t1 = build_ptrmem_type (class2, TYPE_PTRMEM_POINTED_TO_TYPE (t1));
557 else if (DERIVED_FROM_P (class2, class1))
558 t2 = build_ptrmem_type (class1, TYPE_PTRMEM_POINTED_TO_TYPE (t2));
561 error ("%s between distinct pointer-to-member types `%T' and `%T' "
562 "lacks a cast", location, t1, t2);
563 return error_mark_node;
567 return composite_pointer_type_r (t1, t2, location);
570 /* Return the merged type of two types.
571 We assume that comptypes has already been done and returned 1;
572 if that isn't so, this may crash.
574 This just combines attributes and default arguments; any other
575 differences would cause the two types to compare unalike. */
578 merge_types (tree t1, tree t2)
580 enum tree_code code1;
581 enum tree_code code2;
584 /* Save time if the two types are the same. */
587 if (original_type (t1) == original_type (t2))
590 /* If one type is nonsense, use the other. */
591 if (t1 == error_mark_node)
593 if (t2 == error_mark_node)
596 /* Merge the attributes. */
597 attributes = (*targetm.merge_type_attributes) (t1, t2);
599 if (TYPE_PTRMEMFUNC_P (t1))
600 t1 = TYPE_PTRMEMFUNC_FN_TYPE (t1);
601 if (TYPE_PTRMEMFUNC_P (t2))
602 t2 = TYPE_PTRMEMFUNC_FN_TYPE (t2);
604 code1 = TREE_CODE (t1);
605 code2 = TREE_CODE (t2);
611 /* For two pointers, do this recursively on the target type. */
613 tree target = merge_types (TREE_TYPE (t1), TREE_TYPE (t2));
614 int quals = cp_type_quals (t1);
616 if (code1 == POINTER_TYPE)
617 t1 = build_pointer_type (target);
619 t1 = build_reference_type (target);
620 t1 = build_type_attribute_variant (t1, attributes);
621 t1 = cp_build_qualified_type (t1, quals);
623 if (TREE_CODE (target) == METHOD_TYPE)
624 t1 = build_ptrmemfunc_type (t1);
633 quals = cp_type_quals (t1);
634 pointee = merge_types (TYPE_PTRMEM_POINTED_TO_TYPE (t1),
635 TYPE_PTRMEM_POINTED_TO_TYPE (t2));
636 t1 = build_ptrmem_type (TYPE_PTRMEM_CLASS_TYPE (t1),
638 t1 = cp_build_qualified_type (t1, quals);
644 tree elt = merge_types (TREE_TYPE (t1), TREE_TYPE (t2));
645 /* Save space: see if the result is identical to one of the args. */
646 if (elt == TREE_TYPE (t1) && TYPE_DOMAIN (t1))
647 return build_type_attribute_variant (t1, attributes);
648 if (elt == TREE_TYPE (t2) && TYPE_DOMAIN (t2))
649 return build_type_attribute_variant (t2, attributes);
650 /* Merge the element types, and have a size if either arg has one. */
651 t1 = build_cplus_array_type
652 (elt, TYPE_DOMAIN (TYPE_DOMAIN (t1) ? t1 : t2));
657 /* Function types: prefer the one that specified arg types.
658 If both do, merge the arg types. Also merge the return types. */
660 tree valtype = merge_types (TREE_TYPE (t1), TREE_TYPE (t2));
661 tree p1 = TYPE_ARG_TYPES (t1);
662 tree p2 = TYPE_ARG_TYPES (t2);
665 /* Save space: see if the result is identical to one of the args. */
666 if (valtype == TREE_TYPE (t1) && ! p2)
667 return cp_build_type_attribute_variant (t1, attributes);
668 if (valtype == TREE_TYPE (t2) && ! p1)
669 return cp_build_type_attribute_variant (t2, attributes);
671 /* Simple way if one arg fails to specify argument types. */
672 if (p1 == NULL_TREE || TREE_VALUE (p1) == void_type_node)
674 rval = build_function_type (valtype, p2);
675 if ((raises = TYPE_RAISES_EXCEPTIONS (t2)))
676 rval = build_exception_variant (rval, raises);
677 return cp_build_type_attribute_variant (rval, attributes);
679 raises = TYPE_RAISES_EXCEPTIONS (t1);
680 if (p2 == NULL_TREE || TREE_VALUE (p2) == void_type_node)
682 rval = build_function_type (valtype, p1);
684 rval = build_exception_variant (rval, raises);
685 return cp_build_type_attribute_variant (rval, attributes);
688 rval = build_function_type (valtype, commonparms (p1, p2));
689 t1 = build_exception_variant (rval, raises);
695 /* Get this value the long way, since TYPE_METHOD_BASETYPE
696 is just the main variant of this. */
697 tree basetype = TREE_TYPE (TREE_VALUE (TYPE_ARG_TYPES (t2)));
698 tree raises = TYPE_RAISES_EXCEPTIONS (t1);
701 /* If this was a member function type, get back to the
702 original type of type member function (i.e., without
703 the class instance variable up front. */
704 t1 = build_function_type (TREE_TYPE (t1),
705 TREE_CHAIN (TYPE_ARG_TYPES (t1)));
706 t2 = build_function_type (TREE_TYPE (t2),
707 TREE_CHAIN (TYPE_ARG_TYPES (t2)));
708 t3 = merge_types (t1, t2);
709 t3 = build_method_type_directly (basetype, TREE_TYPE (t3),
710 TYPE_ARG_TYPES (t3));
711 t1 = build_exception_variant (t3, raises);
716 /* There is no need to merge attributes into a TYPENAME_TYPE.
717 When the type is instantiated it will have whatever
718 attributes result from the instantiation. */
723 return cp_build_type_attribute_variant (t1, attributes);
726 /* Return the common type of two types.
727 We assume that comptypes has already been done and returned 1;
728 if that isn't so, this may crash.
730 This is the type for the result of most arithmetic operations
731 if the operands have the given two types. */
734 common_type (tree t1, tree t2)
736 enum tree_code code1;
737 enum tree_code code2;
739 /* If one type is nonsense, bail. */
740 if (t1 == error_mark_node || t2 == error_mark_node)
741 return error_mark_node;
743 code1 = TREE_CODE (t1);
744 code2 = TREE_CODE (t2);
746 if ((ARITHMETIC_TYPE_P (t1) || code1 == ENUMERAL_TYPE
747 || code1 == COMPLEX_TYPE)
748 && (ARITHMETIC_TYPE_P (t2) || code2 == ENUMERAL_TYPE
749 || code2 == COMPLEX_TYPE))
750 return type_after_usual_arithmetic_conversions (t1, t2);
752 else if ((TYPE_PTR_P (t1) && TYPE_PTR_P (t2))
753 || (TYPE_PTRMEM_P (t1) && TYPE_PTRMEM_P (t2))
754 || (TYPE_PTRMEMFUNC_P (t1) && TYPE_PTRMEMFUNC_P (t2)))
755 return composite_pointer_type (t1, t2, error_mark_node, error_mark_node,
761 /* Compare two exception specifier types for exactness or subsetness, if
762 allowed. Returns false for mismatch, true for match (same, or
765 [except.spec] "If a class X ... objects of class X or any class publicly
766 and unambiguously derived from X. Similarly, if a pointer type Y * ...
767 exceptions of type Y * or that are pointers to any type publicly and
768 unambiguously derived from Y. Otherwise a function only allows exceptions
769 that have the same type ..."
770 This does not mention cv qualifiers and is different to what throw
771 [except.throw] and catch [except.catch] will do. They will ignore the
772 top level cv qualifiers, and allow qualifiers in the pointer to class
775 We implement the letter of the standard. */
778 comp_except_types (tree a, tree b, bool exact)
780 if (same_type_p (a, b))
784 if (cp_type_quals (a) || cp_type_quals (b))
787 if (TREE_CODE (a) == POINTER_TYPE
788 && TREE_CODE (b) == POINTER_TYPE)
792 if (cp_type_quals (a) || cp_type_quals (b))
796 if (TREE_CODE (a) != RECORD_TYPE
797 || TREE_CODE (b) != RECORD_TYPE)
800 if (ACCESSIBLY_UNIQUELY_DERIVED_P (a, b))
806 /* Return true if TYPE1 and TYPE2 are equivalent exception specifiers.
807 If EXACT is false, T2 can be stricter than T1 (according to 15.4/7),
808 otherwise it must be exact. Exception lists are unordered, but
809 we've already filtered out duplicates. Most lists will be in order,
810 we should try to make use of that. */
813 comp_except_specs (tree t1, tree t2, bool exact)
822 if (t1 == NULL_TREE) /* T1 is ... */
823 return t2 == NULL_TREE || !exact;
824 if (!TREE_VALUE (t1)) /* t1 is EMPTY */
825 return t2 != NULL_TREE && !TREE_VALUE (t2);
826 if (t2 == NULL_TREE) /* T2 is ... */
828 if (TREE_VALUE (t1) && !TREE_VALUE (t2)) /* T2 is EMPTY, T1 is not */
831 /* Neither set is ... or EMPTY, make sure each part of T2 is in T1.
832 Count how many we find, to determine exactness. For exact matching and
833 ordered T1, T2, this is an O(n) operation, otherwise its worst case is
835 for (base = t1; t2 != NULL_TREE; t2 = TREE_CHAIN (t2))
837 for (probe = base; probe != NULL_TREE; probe = TREE_CHAIN (probe))
839 tree a = TREE_VALUE (probe);
840 tree b = TREE_VALUE (t2);
842 if (comp_except_types (a, b, exact))
844 if (probe == base && exact)
845 base = TREE_CHAIN (probe);
850 if (probe == NULL_TREE)
853 return !exact || base == NULL_TREE || length == list_length (t1);
856 /* Compare the array types T1 and T2. ALLOW_REDECLARATION is true if
857 [] can match [size]. */
860 comp_array_types (tree t1, tree t2, bool allow_redeclaration)
869 /* The type of the array elements must be the same. */
870 if (!same_type_p (TREE_TYPE (t1), TREE_TYPE (t2)))
873 d1 = TYPE_DOMAIN (t1);
874 d2 = TYPE_DOMAIN (t2);
879 /* If one of the arrays is dimensionless, and the other has a
880 dimension, they are of different types. However, it is valid to
888 declarations for an array object can specify
889 array types that differ by the presence or absence of a major
890 array bound (_dcl.array_). */
892 return allow_redeclaration;
894 /* Check that the dimensions are the same. */
896 if (!cp_tree_equal (TYPE_MIN_VALUE (d1), TYPE_MIN_VALUE (d2)))
898 max1 = TYPE_MAX_VALUE (d1);
899 max2 = TYPE_MAX_VALUE (d2);
900 if (processing_template_decl && !abi_version_at_least (2)
901 && !value_dependent_expression_p (max1)
902 && !value_dependent_expression_p (max2))
904 /* With abi-1 we do not fold non-dependent array bounds, (and
905 consequently mangle them incorrectly). We must therefore
906 fold them here, to verify the domains have the same
912 if (!cp_tree_equal (max1, max2))
918 /* Return true if T1 and T2 are related as allowed by STRICT. STRICT
919 is a bitwise-or of the COMPARE_* flags. */
922 comptypes (tree t1, tree t2, int strict)
927 /* Suppress errors caused by previously reported errors. */
928 if (t1 == error_mark_node || t2 == error_mark_node)
931 my_friendly_assert (TYPE_P (t1) && TYPE_P (t2), 20030623);
933 /* TYPENAME_TYPEs should be resolved if the qualifying scope is the
934 current instantiation. */
935 if (TREE_CODE (t1) == TYPENAME_TYPE)
937 tree resolved = resolve_typename_type (t1, /*only_current_p=*/true);
939 if (resolved != error_mark_node)
943 if (TREE_CODE (t2) == TYPENAME_TYPE)
945 tree resolved = resolve_typename_type (t2, /*only_current_p=*/true);
947 if (resolved != error_mark_node)
951 /* If either type is the internal version of sizetype, use the
953 if (TREE_CODE (t1) == INTEGER_TYPE && TYPE_IS_SIZETYPE (t1)
954 && TYPE_ORIG_SIZE_TYPE (t1))
955 t1 = TYPE_ORIG_SIZE_TYPE (t1);
957 if (TREE_CODE (t2) == INTEGER_TYPE && TYPE_IS_SIZETYPE (t2)
958 && TYPE_ORIG_SIZE_TYPE (t2))
959 t2 = TYPE_ORIG_SIZE_TYPE (t2);
961 if (TYPE_PTRMEMFUNC_P (t1))
962 t1 = TYPE_PTRMEMFUNC_FN_TYPE (t1);
963 if (TYPE_PTRMEMFUNC_P (t2))
964 t2 = TYPE_PTRMEMFUNC_FN_TYPE (t2);
966 /* Different classes of types can't be compatible. */
967 if (TREE_CODE (t1) != TREE_CODE (t2))
970 /* Qualifiers must match. For array types, we will check when we
971 recur on the array element types. */
972 if (TREE_CODE (t1) != ARRAY_TYPE
973 && TYPE_QUALS (t1) != TYPE_QUALS (t2))
975 if (TYPE_FOR_JAVA (t1) != TYPE_FOR_JAVA (t2))
978 /* Allow for two different type nodes which have essentially the same
979 definition. Note that we already checked for equality of the type
980 qualifiers (just above). */
982 if (TREE_CODE (t1) != ARRAY_TYPE
983 && TYPE_MAIN_VARIANT (t1) == TYPE_MAIN_VARIANT (t2))
986 if (!(*targetm.comp_type_attributes) (t1, t2))
989 switch (TREE_CODE (t1))
991 case TEMPLATE_TEMPLATE_PARM:
992 case BOUND_TEMPLATE_TEMPLATE_PARM:
993 if (TEMPLATE_TYPE_IDX (t1) != TEMPLATE_TYPE_IDX (t2)
994 || TEMPLATE_TYPE_LEVEL (t1) != TEMPLATE_TYPE_LEVEL (t2))
996 if (!comp_template_parms
997 (DECL_TEMPLATE_PARMS (TEMPLATE_TEMPLATE_PARM_TEMPLATE_DECL (t1)),
998 DECL_TEMPLATE_PARMS (TEMPLATE_TEMPLATE_PARM_TEMPLATE_DECL (t2))))
1000 if (TREE_CODE (t1) == TEMPLATE_TEMPLATE_PARM)
1002 /* Don't check inheritance. */
1003 strict = COMPARE_STRICT;
1008 if (TYPE_TEMPLATE_INFO (t1) && TYPE_TEMPLATE_INFO (t2)
1009 && (TYPE_TI_TEMPLATE (t1) == TYPE_TI_TEMPLATE (t2)
1010 || TREE_CODE (t1) == BOUND_TEMPLATE_TEMPLATE_PARM)
1011 && comp_template_args (TYPE_TI_ARGS (t1), TYPE_TI_ARGS (t2)))
1014 if ((strict & COMPARE_BASE) && DERIVED_FROM_P (t1, t2))
1016 else if ((strict & COMPARE_DERIVED) && DERIVED_FROM_P (t2, t1))
1022 if (!comptypes (TYPE_OFFSET_BASETYPE (t1), TYPE_OFFSET_BASETYPE (t2),
1023 strict & ~COMPARE_REDECLARATION))
1028 case REFERENCE_TYPE:
1029 return same_type_p (TREE_TYPE (t1), TREE_TYPE (t2));
1033 if (!same_type_p (TREE_TYPE (t1), TREE_TYPE (t2)))
1035 return compparms (TYPE_ARG_TYPES (t1), TYPE_ARG_TYPES (t2));
1038 /* Target types must match incl. qualifiers. */
1039 return comp_array_types (t1, t2, !!(strict & COMPARE_REDECLARATION));
1041 case TEMPLATE_TYPE_PARM:
1042 return (TEMPLATE_TYPE_IDX (t1) == TEMPLATE_TYPE_IDX (t2)
1043 && TEMPLATE_TYPE_LEVEL (t1) == TEMPLATE_TYPE_LEVEL (t2));
1046 if (!cp_tree_equal (TYPENAME_TYPE_FULLNAME (t1),
1047 TYPENAME_TYPE_FULLNAME (t2)))
1049 return same_type_p (TYPE_CONTEXT (t1), TYPE_CONTEXT (t2));
1051 case UNBOUND_CLASS_TEMPLATE:
1052 if (!cp_tree_equal (TYPE_IDENTIFIER (t1), TYPE_IDENTIFIER (t2)))
1054 return same_type_p (TYPE_CONTEXT (t1), TYPE_CONTEXT (t2));
1057 return same_type_p (TREE_TYPE (t1), TREE_TYPE (t2));
1060 return TYPE_VECTOR_SUBPARTS (t1) == TYPE_VECTOR_SUBPARTS (t2)
1061 && same_type_p (TREE_TYPE (t1), TREE_TYPE (t2));
1070 /* Returns 1 if TYPE1 is at least as qualified as TYPE2. */
1073 at_least_as_qualified_p (tree type1, tree type2)
1075 int q1 = cp_type_quals (type1);
1076 int q2 = cp_type_quals (type2);
1078 /* All qualifiers for TYPE2 must also appear in TYPE1. */
1079 return (q1 & q2) == q2;
1082 /* Returns 1 if TYPE1 is more qualified than TYPE2. */
1085 more_qualified_p (tree type1, tree type2)
1087 int q1 = cp_type_quals (type1);
1088 int q2 = cp_type_quals (type2);
1090 return q1 != q2 && (q1 & q2) == q2;
1093 /* Returns 1 if TYPE1 is more cv-qualified than TYPE2, -1 if TYPE2 is
1094 more cv-qualified that TYPE1, and 0 otherwise. */
1097 comp_cv_qualification (tree type1, tree type2)
1099 int q1 = cp_type_quals (type1);
1100 int q2 = cp_type_quals (type2);
1105 if ((q1 & q2) == q2)
1107 else if ((q1 & q2) == q1)
1113 /* Returns 1 if the cv-qualification signature of TYPE1 is a proper
1114 subset of the cv-qualification signature of TYPE2, and the types
1115 are similar. Returns -1 if the other way 'round, and 0 otherwise. */
1118 comp_cv_qual_signature (tree type1, tree type2)
1120 if (comp_ptr_ttypes_real (type2, type1, -1))
1122 else if (comp_ptr_ttypes_real (type1, type2, -1))
1128 /* If two types share a common base type, return that basetype.
1129 If there is not a unique most-derived base type, this function
1130 returns ERROR_MARK_NODE. */
1133 common_base_type (tree tt1, tree tt2)
1135 tree best = NULL_TREE;
1138 /* If one is a baseclass of another, that's good enough. */
1139 if (UNIQUELY_DERIVED_FROM_P (tt1, tt2))
1141 if (UNIQUELY_DERIVED_FROM_P (tt2, tt1))
1144 /* Otherwise, try to find a unique baseclass of TT1
1145 that is shared by TT2, and follow that down. */
1146 for (i = CLASSTYPE_N_BASECLASSES (tt1)-1; i >= 0; i--)
1148 tree basetype = TYPE_BINFO_BASETYPE (tt1, i);
1149 tree trial = common_base_type (basetype, tt2);
1152 if (trial == error_mark_node)
1154 if (best == NULL_TREE)
1156 else if (best != trial)
1157 return error_mark_node;
1162 for (i = CLASSTYPE_N_BASECLASSES (tt2)-1; i >= 0; i--)
1164 tree basetype = TYPE_BINFO_BASETYPE (tt2, i);
1165 tree trial = common_base_type (tt1, basetype);
1168 if (trial == error_mark_node)
1170 if (best == NULL_TREE)
1172 else if (best != trial)
1173 return error_mark_node;
1179 /* Subroutines of `comptypes'. */
1181 /* Return true if two parameter type lists PARMS1 and PARMS2 are
1182 equivalent in the sense that functions with those parameter types
1183 can have equivalent types. The two lists must be equivalent,
1184 element by element. */
1187 compparms (tree parms1, tree parms2)
1191 /* An unspecified parmlist matches any specified parmlist
1192 whose argument types don't need default promotions. */
1194 for (t1 = parms1, t2 = parms2;
1196 t1 = TREE_CHAIN (t1), t2 = TREE_CHAIN (t2))
1198 /* If one parmlist is shorter than the other,
1199 they fail to match. */
1202 if (!same_type_p (TREE_VALUE (t1), TREE_VALUE (t2)))
1209 /* Process a sizeof or alignof expression where the operand is a
1213 cxx_sizeof_or_alignof_type (tree type, enum tree_code op, bool complain)
1215 enum tree_code type_code;
1217 const char *op_name;
1219 my_friendly_assert (op == SIZEOF_EXPR || op == ALIGNOF_EXPR, 20020720);
1220 if (type == error_mark_node)
1221 return error_mark_node;
1223 if (processing_template_decl)
1225 value = build_min (op, size_type_node, type);
1226 TREE_READONLY (value) = 1;
1230 op_name = operator_name_info[(int) op].name;
1232 type = non_reference (type);
1233 type_code = TREE_CODE (type);
1235 if (type_code == METHOD_TYPE)
1237 if (complain && (pedantic || warn_pointer_arith))
1238 pedwarn ("invalid application of `%s' to a member function", op_name);
1239 value = size_one_node;
1242 value = c_sizeof_or_alignof_type (complete_type (type), op, complain);
1247 /* Process a sizeof or alignof expression where the operand is an
1251 cxx_sizeof_or_alignof_expr (tree e, enum tree_code op)
1253 const char *op_name = operator_name_info[(int) op].name;
1255 if (e == error_mark_node)
1256 return error_mark_node;
1258 if (processing_template_decl)
1260 e = build_min (op, size_type_node, e);
1261 TREE_SIDE_EFFECTS (e) = 0;
1262 TREE_READONLY (e) = 1;
1267 if (TREE_CODE (e) == COMPONENT_REF
1268 && TREE_CODE (TREE_OPERAND (e, 1)) == FIELD_DECL
1269 && DECL_C_BIT_FIELD (TREE_OPERAND (e, 1)))
1271 error ("invalid application of `%s' to a bit-field", op_name);
1274 else if (is_overloaded_fn (e))
1276 pedwarn ("ISO C++ forbids applying `%s' to an expression of function type", op_name);
1279 else if (type_unknown_p (e))
1281 cxx_incomplete_type_error (e, TREE_TYPE (e));
1287 return cxx_sizeof_or_alignof_type (e, op, true);
1291 /* EXPR is being used in a context that is not a function call.
1296 The expression can be used only as the left-hand operand of a
1297 member function call.
1299 [expr.mptr.operator]
1301 If the result of .* or ->* is a function, then that result can be
1302 used only as the operand for the function call operator ().
1304 by issuing an error message if appropriate. Returns true iff EXPR
1305 violates these rules. */
1308 invalid_nonstatic_memfn_p (tree expr)
1310 if (TREE_CODE (TREE_TYPE (expr)) == METHOD_TYPE)
1312 error ("invalid use of non-static member function");
1318 /* Perform the conversions in [expr] that apply when an lvalue appears
1319 in an rvalue context: the lvalue-to-rvalue, array-to-pointer, and
1320 function-to-pointer conversions.
1322 In addition manifest constants are replaced by their values. */
1325 decay_conversion (tree exp)
1328 enum tree_code code;
1330 type = TREE_TYPE (exp);
1331 code = TREE_CODE (type);
1333 if (code == REFERENCE_TYPE)
1335 exp = convert_from_reference (exp);
1336 type = TREE_TYPE (exp);
1337 code = TREE_CODE (type);
1340 if (type == error_mark_node)
1341 return error_mark_node;
1343 if (type_unknown_p (exp))
1345 cxx_incomplete_type_error (exp, TREE_TYPE (exp));
1346 return error_mark_node;
1349 /* Constants can be used directly unless they're not loadable. */
1350 if (TREE_CODE (exp) == CONST_DECL)
1351 exp = DECL_INITIAL (exp);
1352 /* Replace a nonvolatile const static variable with its value. We
1353 don't do this for arrays, though; we want the address of the
1354 first element of the array, not the address of the first element
1355 of its initializing constant. */
1356 else if (code != ARRAY_TYPE)
1358 exp = decl_constant_value (exp);
1359 type = TREE_TYPE (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 build (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 my_friendly_assert (INTEGRAL_OR_ENUMERATION_TYPE_P (type), 20030703);
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 ("deprecated conversion from string constant to `%T'", 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)
1519 build_conditional_expr (build_x_binary_op ((TREE_CODE (t) == MIN_EXPR
1520 ? LE_EXPR : GE_EXPR),
1521 TREE_OPERAND (t, 0),
1522 TREE_OPERAND (t, 1),
1523 /*overloaded_p=*/NULL),
1524 build_unary_op (code, TREE_OPERAND (t, 0), 0),
1525 build_unary_op (code, TREE_OPERAND (t, 1), 0));
1529 build_conditional_expr (TREE_OPERAND (t, 0),
1530 build_unary_op (code, TREE_OPERAND (t, 1), 0),
1531 build_unary_op (code, TREE_OPERAND (t, 2), 0));
1534 /* Given the TYPE of an anonymous union field inside T, return the
1535 FIELD_DECL for the field. If not found return NULL_TREE. Because
1536 anonymous unions can nest, we must also search all anonymous unions
1537 that are directly reachable. */
1540 lookup_anon_field (tree t, tree type)
1544 for (field = TYPE_FIELDS (t); field; field = TREE_CHAIN (field))
1546 if (TREE_STATIC (field))
1548 if (TREE_CODE (field) != FIELD_DECL || DECL_ARTIFICIAL (field))
1551 /* If we find it directly, return the field. */
1552 if (DECL_NAME (field) == NULL_TREE
1553 && type == TYPE_MAIN_VARIANT (TREE_TYPE (field)))
1558 /* Otherwise, it could be nested, search harder. */
1559 if (DECL_NAME (field) == NULL_TREE
1560 && ANON_AGGR_TYPE_P (TREE_TYPE (field)))
1562 tree subfield = lookup_anon_field (TREE_TYPE (field), type);
1570 /* Build an expression representing OBJECT.MEMBER. OBJECT is an
1571 expression; MEMBER is a DECL or baselink. If ACCESS_PATH is
1572 non-NULL, it indicates the path to the base used to name MEMBER.
1573 If PRESERVE_REFERENCE is true, the expression returned will have
1574 REFERENCE_TYPE if the MEMBER does. Otherwise, the expression
1575 returned will have the type referred to by the reference.
1577 This function does not perform access control; that is either done
1578 earlier by the parser when the name of MEMBER is resolved to MEMBER
1579 itself, or later when overload resolution selects one of the
1580 functions indicated by MEMBER. */
1583 build_class_member_access_expr (tree object, tree member,
1584 tree access_path, bool preserve_reference)
1588 tree result = NULL_TREE;
1590 if (object == error_mark_node || member == error_mark_node)
1591 return error_mark_node;
1593 if (TREE_CODE (member) == PSEUDO_DTOR_EXPR)
1596 my_friendly_assert (DECL_P (member) || BASELINK_P (member),
1601 The type of the first expression shall be "class object" (of a
1603 object_type = TREE_TYPE (object);
1604 if (!currently_open_class (object_type)
1605 && !complete_type_or_else (object_type, object))
1606 return error_mark_node;
1607 if (!CLASS_TYPE_P (object_type))
1609 error ("request for member `%D' in `%E', which is of non-class type `%T'",
1610 member, object, object_type);
1611 return error_mark_node;
1614 /* The standard does not seem to actually say that MEMBER must be a
1615 member of OBJECT_TYPE. However, that is clearly what is
1617 if (DECL_P (member))
1619 member_scope = DECL_CLASS_CONTEXT (member);
1621 if (TREE_DEPRECATED (member))
1622 warn_deprecated_use (member);
1625 member_scope = BINFO_TYPE (BASELINK_BINFO (member));
1626 /* If MEMBER is from an anonymous aggregate, MEMBER_SCOPE will
1627 presently be the anonymous union. Go outwards until we find a
1628 type related to OBJECT_TYPE. */
1629 while (ANON_AGGR_TYPE_P (member_scope)
1630 && !same_type_ignoring_top_level_qualifiers_p (member_scope,
1632 member_scope = TYPE_CONTEXT (member_scope);
1633 if (!member_scope || !DERIVED_FROM_P (member_scope, object_type))
1635 if (TREE_CODE (member) == FIELD_DECL)
1636 error ("invalid use of nonstatic data member '%E'", member);
1638 error ("`%D' is not a member of `%T'", member, object_type);
1639 return error_mark_node;
1642 /* Transform `(a, b).x' into `(*(a, &b)).x', `(a ? b : c).x' into
1643 `(*(a ? &b : &c)).x', and so on. A COND_EXPR is only an lvalue
1644 in the frontend; only _DECLs and _REFs are lvalues in the backend. */
1646 tree temp = unary_complex_lvalue (ADDR_EXPR, object);
1648 object = build_indirect_ref (temp, NULL);
1651 /* In [expr.ref], there is an explicit list of the valid choices for
1652 MEMBER. We check for each of those cases here. */
1653 if (TREE_CODE (member) == VAR_DECL)
1655 /* A static data member. */
1657 /* If OBJECT has side-effects, they are supposed to occur. */
1658 if (TREE_SIDE_EFFECTS (object))
1659 result = build (COMPOUND_EXPR, TREE_TYPE (result), object, result);
1661 else if (TREE_CODE (member) == FIELD_DECL)
1663 /* A non-static data member. */
1668 null_object_p = (TREE_CODE (object) == INDIRECT_REF
1669 && integer_zerop (TREE_OPERAND (object, 0)));
1671 /* Convert OBJECT to the type of MEMBER. */
1672 if (!same_type_p (TYPE_MAIN_VARIANT (object_type),
1673 TYPE_MAIN_VARIANT (member_scope)))
1678 binfo = lookup_base (access_path ? access_path : object_type,
1679 member_scope, ba_ignore, &kind);
1680 if (binfo == error_mark_node)
1681 return error_mark_node;
1683 /* It is invalid to try to get to a virtual base of a
1684 NULL object. The most common cause is invalid use of
1686 if (null_object_p && kind == bk_via_virtual)
1688 error ("invalid access to non-static data member `%D' of NULL object",
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 my_friendly_assert (object != error_mark_node,
1703 /* Complain about other invalid uses of offsetof, even though they will
1704 give the right answer. Note that we complain whether or not they
1705 actually used the offsetof macro, since there's no way to know at this
1706 point. So we just give a warning, instead of a pedwarn. */
1707 if (null_object_p && warn_invalid_offsetof
1708 && CLASSTYPE_NON_POD_P (object_type))
1710 warning ("invalid access to non-static data member `%D' of NULL object",
1712 warning ("(perhaps the `offsetof' macro was used incorrectly)");
1715 /* If MEMBER is from an anonymous aggregate, we have converted
1716 OBJECT so that it refers to the class containing the
1717 anonymous union. Generate a reference to the anonymous union
1718 itself, and recur to find MEMBER. */
1719 if (ANON_AGGR_TYPE_P (DECL_CONTEXT (member))
1720 /* When this code is called from build_field_call, the
1721 object already has the type of the anonymous union.
1722 That is because the COMPONENT_REF was already
1723 constructed, and was then disassembled before calling
1724 build_field_call. After the function-call code is
1725 cleaned up, this waste can be eliminated. */
1726 && (!same_type_ignoring_top_level_qualifiers_p
1727 (TREE_TYPE (object), DECL_CONTEXT (member))))
1729 tree anonymous_union;
1731 anonymous_union = lookup_anon_field (TREE_TYPE (object),
1732 DECL_CONTEXT (member));
1733 object = build_class_member_access_expr (object,
1735 /*access_path=*/NULL_TREE,
1736 preserve_reference);
1739 /* Compute the type of the field, as described in [expr.ref]. */
1740 type_quals = TYPE_UNQUALIFIED;
1741 member_type = TREE_TYPE (member);
1742 if (TREE_CODE (member_type) != REFERENCE_TYPE)
1744 type_quals = (cp_type_quals (member_type)
1745 | cp_type_quals (object_type));
1747 /* A field is const (volatile) if the enclosing object, or the
1748 field itself, is const (volatile). But, a mutable field is
1749 not const, even within a const object. */
1750 if (DECL_MUTABLE_P (member))
1751 type_quals &= ~TYPE_QUAL_CONST;
1752 member_type = cp_build_qualified_type (member_type, type_quals);
1755 result = fold (build (COMPONENT_REF, member_type, object, member,
1758 /* Mark the expression const or volatile, as appropriate. Even
1759 though we've dealt with the type above, we still have to mark the
1760 expression itself. */
1761 if (type_quals & TYPE_QUAL_CONST)
1762 TREE_READONLY (result) = 1;
1763 else if (type_quals & TYPE_QUAL_VOLATILE)
1764 TREE_THIS_VOLATILE (result) = 1;
1766 else if (BASELINK_P (member))
1768 /* The member is a (possibly overloaded) member function. */
1772 /* If the MEMBER is exactly one static member function, then we
1773 know the type of the expression. Otherwise, we must wait
1774 until overload resolution has been performed. */
1775 functions = BASELINK_FUNCTIONS (member);
1776 if (TREE_CODE (functions) == FUNCTION_DECL
1777 && DECL_STATIC_FUNCTION_P (functions))
1778 type = TREE_TYPE (functions);
1780 type = unknown_type_node;
1781 /* Note that we do not convert OBJECT to the BASELINK_BINFO
1782 base. That will happen when the function is called. */
1783 result = build (COMPONENT_REF, type, object, member, NULL_TREE);
1785 else if (TREE_CODE (member) == CONST_DECL)
1787 /* The member is an enumerator. */
1789 /* If OBJECT has side-effects, they are supposed to occur. */
1790 if (TREE_SIDE_EFFECTS (object))
1791 result = build (COMPOUND_EXPR, TREE_TYPE (result),
1796 error ("invalid use of `%D'", member);
1797 return error_mark_node;
1800 if (!preserve_reference)
1803 If E2 is declared to have type "reference to T", then ... the
1804 type of E1.E2 is T. */
1805 result = convert_from_reference (result);
1810 /* Return the destructor denoted by OBJECT.SCOPE::~DTOR_NAME, or, if
1811 SCOPE is NULL, by OBJECT.~DTOR_NAME. */
1814 lookup_destructor (tree object, tree scope, tree dtor_name)
1816 tree object_type = TREE_TYPE (object);
1817 tree dtor_type = TREE_OPERAND (dtor_name, 0);
1820 if (scope && !check_dtor_name (scope, dtor_name))
1822 error ("qualified type `%T' does not match destructor name `~%T'",
1824 return error_mark_node;
1826 if (!DERIVED_FROM_P (dtor_type, TYPE_MAIN_VARIANT (object_type)))
1828 error ("the type being destroyed is `%T', but the destructor refers to `%T'",
1829 TYPE_MAIN_VARIANT (object_type), dtor_type);
1830 return error_mark_node;
1832 if (!TYPE_HAS_DESTRUCTOR (dtor_type))
1833 return build (PSEUDO_DTOR_EXPR, void_type_node, object, scope,
1835 expr = lookup_member (dtor_type, complete_dtor_identifier,
1836 /*protect=*/1, /*want_type=*/false);
1837 expr = (adjust_result_of_qualified_name_lookup
1838 (expr, dtor_type, object_type));
1842 /* This function is called by the parser to process a class member
1843 access expression of the form OBJECT.NAME. NAME is a node used by
1844 the parser to represent a name; it is not yet a DECL. It may,
1845 however, be a BASELINK where the BASELINK_FUNCTIONS is a
1846 TEMPLATE_ID_EXPR. Templates must be looked up by the parser, and
1847 there is no reason to do the lookup twice, so the parser keeps the
1851 finish_class_member_access_expr (tree object, tree name)
1856 tree access_path = NULL_TREE;
1857 tree orig_object = object;
1858 tree orig_name = name;
1860 if (object == error_mark_node || name == error_mark_node)
1861 return error_mark_node;
1863 object_type = TREE_TYPE (object);
1865 if (processing_template_decl)
1867 if (/* If OBJECT_TYPE is dependent, so is OBJECT.NAME. */
1868 dependent_type_p (object_type)
1869 /* If NAME is just an IDENTIFIER_NODE, then the expression
1871 || TREE_CODE (object) == IDENTIFIER_NODE
1872 /* If NAME is "f<args>", where either 'f' or 'args' is
1873 dependent, then the expression is dependent. */
1874 || (TREE_CODE (name) == TEMPLATE_ID_EXPR
1875 && dependent_template_id_p (TREE_OPERAND (name, 0),
1876 TREE_OPERAND (name, 1)))
1877 /* If NAME is "T::X" where "T" is dependent, then the
1878 expression is dependent. */
1879 || (TREE_CODE (name) == SCOPE_REF
1880 && TYPE_P (TREE_OPERAND (name, 0))
1881 && dependent_type_p (TREE_OPERAND (name, 0))))
1882 return build_min_nt (COMPONENT_REF, object, name, NULL_TREE);
1883 object = build_non_dependent_expr (object);
1886 if (TREE_CODE (object_type) == REFERENCE_TYPE)
1888 object = convert_from_reference (object);
1889 object_type = TREE_TYPE (object);
1894 The type of the first expression shall be "class object" (of a
1896 if (!currently_open_class (object_type)
1897 && !complete_type_or_else (object_type, object))
1898 return error_mark_node;
1899 if (!CLASS_TYPE_P (object_type))
1901 error ("request for member `%D' in `%E', which is of non-class type `%T'",
1902 name, object, object_type);
1903 return error_mark_node;
1906 if (BASELINK_P (name))
1908 /* A member function that has already been looked up. */
1909 my_friendly_assert ((TREE_CODE (BASELINK_FUNCTIONS (name))
1910 == TEMPLATE_ID_EXPR),
1916 bool is_template_id = false;
1917 tree template_args = NULL_TREE;
1920 if (TREE_CODE (name) == TEMPLATE_ID_EXPR)
1922 is_template_id = true;
1923 template_args = TREE_OPERAND (name, 1);
1924 name = TREE_OPERAND (name, 0);
1926 if (TREE_CODE (name) == OVERLOAD)
1927 name = DECL_NAME (get_first_fn (name));
1928 else if (DECL_P (name))
1929 name = DECL_NAME (name);
1932 if (TREE_CODE (name) == SCOPE_REF)
1934 /* A qualified name. The qualifying class or namespace `S' has
1935 already been looked up; it is either a TYPE or a
1936 NAMESPACE_DECL. The member name is either an IDENTIFIER_NODE
1937 or a BIT_NOT_EXPR. */
1938 scope = TREE_OPERAND (name, 0);
1939 name = TREE_OPERAND (name, 1);
1940 my_friendly_assert ((CLASS_TYPE_P (scope)
1941 || TREE_CODE (scope) == NAMESPACE_DECL),
1943 my_friendly_assert ((TREE_CODE (name) == IDENTIFIER_NODE
1944 || TREE_CODE (name) == BIT_NOT_EXPR),
1947 /* If SCOPE is a namespace, then the qualified name does not
1948 name a member of OBJECT_TYPE. */
1949 if (TREE_CODE (scope) == NAMESPACE_DECL)
1951 error ("`%D::%D' is not a member of `%T'",
1952 scope, name, object_type);
1953 return error_mark_node;
1956 /* Find the base of OBJECT_TYPE corresponding to SCOPE. */
1957 access_path = lookup_base (object_type, scope, ba_check, NULL);
1958 if (access_path == error_mark_node)
1959 return error_mark_node;
1962 error ("`%T' is not a base of `%T'", scope, object_type);
1963 return error_mark_node;
1969 access_path = object_type;
1972 if (TREE_CODE (name) == BIT_NOT_EXPR)
1973 member = lookup_destructor (object, scope, name);
1976 /* Look up the member. */
1977 member = lookup_member (access_path, name, /*protect=*/1,
1978 /*want_type=*/false);
1979 if (member == NULL_TREE)
1981 error ("'%D' has no member named '%E'", object_type, name);
1982 return error_mark_node;
1984 if (member == error_mark_node)
1985 return error_mark_node;
1990 tree template = member;
1992 if (BASELINK_P (template))
1993 template = lookup_template_function (template, template_args);
1996 error ("`%D' is not a member template function", name);
1997 return error_mark_node;
2002 if (TREE_DEPRECATED (member))
2003 warn_deprecated_use (member);
2005 expr = build_class_member_access_expr (object, member, access_path,
2006 /*preserve_reference=*/false);
2007 if (processing_template_decl && expr != error_mark_node)
2008 return build_min_non_dep (COMPONENT_REF, expr,
2009 orig_object, orig_name, NULL_TREE);
2013 /* Return an expression for the MEMBER_NAME field in the internal
2014 representation of PTRMEM, a pointer-to-member function. (Each
2015 pointer-to-member function type gets its own RECORD_TYPE so it is
2016 more convenient to access the fields by name than by FIELD_DECL.)
2017 This routine converts the NAME to a FIELD_DECL and then creates the
2018 node for the complete expression. */
2021 build_ptrmemfunc_access_expr (tree ptrmem, tree member_name)
2027 /* This code is a stripped down version of
2028 build_class_member_access_expr. It does not work to use that
2029 routine directly because it expects the object to be of class
2031 ptrmem_type = TREE_TYPE (ptrmem);
2032 my_friendly_assert (TYPE_PTRMEMFUNC_P (ptrmem_type), 20020804);
2033 member = lookup_member (ptrmem_type, member_name, /*protect=*/0,
2034 /*want_type=*/false);
2035 member_type = cp_build_qualified_type (TREE_TYPE (member),
2036 cp_type_quals (ptrmem_type));
2037 return fold (build (COMPONENT_REF, member_type, ptrmem, member, NULL_TREE));
2040 /* Given an expression PTR for a pointer, return an expression
2041 for the value pointed to.
2042 ERRORSTRING is the name of the operator to appear in error messages.
2044 This function may need to overload OPERATOR_FNNAME.
2045 Must also handle REFERENCE_TYPEs for C++. */
2048 build_x_indirect_ref (tree expr, const char *errorstring)
2050 tree orig_expr = expr;
2053 if (processing_template_decl)
2055 if (type_dependent_expression_p (expr))
2056 return build_min_nt (INDIRECT_REF, expr);
2057 expr = build_non_dependent_expr (expr);
2060 rval = build_new_op (INDIRECT_REF, LOOKUP_NORMAL, expr, NULL_TREE,
2061 NULL_TREE, /*overloaded_p=*/NULL);
2063 rval = build_indirect_ref (expr, errorstring);
2065 if (processing_template_decl && rval != error_mark_node)
2066 return build_min_non_dep (INDIRECT_REF, rval, orig_expr);
2072 build_indirect_ref (tree ptr, const char *errorstring)
2076 if (ptr == error_mark_node)
2077 return error_mark_node;
2079 if (ptr == current_class_ptr)
2080 return current_class_ref;
2082 pointer = (TREE_CODE (TREE_TYPE (ptr)) == REFERENCE_TYPE
2083 ? ptr : decay_conversion (ptr));
2084 type = TREE_TYPE (pointer);
2086 if (TYPE_PTR_P (type) || TREE_CODE (type) == REFERENCE_TYPE)
2090 If the type of the expression is "pointer to T," the type
2091 of the result is "T."
2093 We must use the canonical variant because certain parts of
2094 the back end, like fold, do pointer comparisons between
2096 tree t = canonical_type_variant (TREE_TYPE (type));
2098 if (VOID_TYPE_P (t))
2100 /* A pointer to incomplete type (other than cv void) can be
2101 dereferenced [expr.unary.op]/1 */
2102 error ("`%T' is not a pointer-to-object type", type);
2103 return error_mark_node;
2105 else if (TREE_CODE (pointer) == ADDR_EXPR
2106 && same_type_p (t, TREE_TYPE (TREE_OPERAND (pointer, 0))))
2107 /* The POINTER was something like `&x'. We simplify `*&x' to
2109 return TREE_OPERAND (pointer, 0);
2112 tree ref = build1 (INDIRECT_REF, t, pointer);
2114 /* We *must* set TREE_READONLY when dereferencing a pointer to const,
2115 so that we get the proper error message if the result is used
2116 to assign to. Also, &* is supposed to be a no-op. */
2117 TREE_READONLY (ref) = CP_TYPE_CONST_P (t);
2118 TREE_THIS_VOLATILE (ref) = CP_TYPE_VOLATILE_P (t);
2119 TREE_SIDE_EFFECTS (ref)
2120 = (TREE_THIS_VOLATILE (ref) || TREE_SIDE_EFFECTS (pointer));
2124 /* `pointer' won't be an error_mark_node if we were given a
2125 pointer to member, so it's cool to check for this here. */
2126 else if (TYPE_PTR_TO_MEMBER_P (type))
2127 error ("invalid use of `%s' on pointer to member", errorstring);
2128 else if (pointer != error_mark_node)
2131 error ("invalid type argument of `%s'", errorstring);
2133 error ("invalid type argument");
2135 return error_mark_node;
2138 /* This handles expressions of the form "a[i]", which denotes
2141 This is logically equivalent in C to *(a+i), but we may do it differently.
2142 If A is a variable or a member, we generate a primitive ARRAY_REF.
2143 This avoids forcing the array out of registers, and can work on
2144 arrays that are not lvalues (for example, members of structures returned
2147 If INDEX is of some user-defined type, it must be converted to
2148 integer type. Otherwise, to make a compatible PLUS_EXPR, it
2149 will inherit the type of the array, which will be some pointer type. */
2152 build_array_ref (tree array, tree idx)
2156 error ("subscript missing in array reference");
2157 return error_mark_node;
2160 if (TREE_TYPE (array) == error_mark_node
2161 || TREE_TYPE (idx) == error_mark_node)
2162 return error_mark_node;
2164 /* If ARRAY is a COMPOUND_EXPR or COND_EXPR, move our reference
2166 switch (TREE_CODE (array))
2170 tree value = build_array_ref (TREE_OPERAND (array, 1), idx);
2171 return build (COMPOUND_EXPR, TREE_TYPE (value),
2172 TREE_OPERAND (array, 0), value);
2176 return build_conditional_expr
2177 (TREE_OPERAND (array, 0),
2178 build_array_ref (TREE_OPERAND (array, 1), idx),
2179 build_array_ref (TREE_OPERAND (array, 2), idx));
2185 if (TREE_CODE (TREE_TYPE (array)) == ARRAY_TYPE)
2189 /* Subscripting with type char is likely to lose
2190 on a machine where chars are signed.
2191 So warn on any machine, but optionally.
2192 Don't warn for unsigned char since that type is safe.
2193 Don't warn for signed char because anyone who uses that
2194 must have done so deliberately. */
2195 if (warn_char_subscripts
2196 && TYPE_MAIN_VARIANT (TREE_TYPE (idx)) == char_type_node)
2197 warning ("array subscript has type `char'");
2199 if (!INTEGRAL_OR_ENUMERATION_TYPE_P (TREE_TYPE (idx)))
2201 error ("array subscript is not an integer");
2202 return error_mark_node;
2205 /* Apply integral promotions *after* noticing character types.
2206 (It is unclear why we do these promotions -- the standard
2207 does not say that we should. In fact, the natual thing would
2208 seem to be to convert IDX to ptrdiff_t; we're performing
2209 pointer arithmetic.) */
2210 idx = perform_integral_promotions (idx);
2212 /* An array that is indexed by a non-constant
2213 cannot be stored in a register; we must be able to do
2214 address arithmetic on its address.
2215 Likewise an array of elements of variable size. */
2216 if (TREE_CODE (idx) != INTEGER_CST
2217 || (COMPLETE_TYPE_P (TREE_TYPE (TREE_TYPE (array)))
2218 && (TREE_CODE (TYPE_SIZE (TREE_TYPE (TREE_TYPE (array))))
2221 if (!cxx_mark_addressable (array))
2222 return error_mark_node;
2225 /* An array that is indexed by a constant value which is not within
2226 the array bounds cannot be stored in a register either; because we
2227 would get a crash in store_bit_field/extract_bit_field when trying
2228 to access a non-existent part of the register. */
2229 if (TREE_CODE (idx) == INTEGER_CST
2230 && TYPE_DOMAIN (TREE_TYPE (array))
2231 && ! int_fits_type_p (idx, TYPE_DOMAIN (TREE_TYPE (array))))
2233 if (!cxx_mark_addressable (array))
2234 return error_mark_node;
2237 if (pedantic && !lvalue_p (array))
2238 pedwarn ("ISO C++ forbids subscripting non-lvalue array");
2240 /* Note in C++ it is valid to subscript a `register' array, since
2241 it is valid to take the address of something with that
2242 storage specification. */
2246 while (TREE_CODE (foo) == COMPONENT_REF)
2247 foo = TREE_OPERAND (foo, 0);
2248 if (TREE_CODE (foo) == VAR_DECL && DECL_REGISTER (foo))
2249 warning ("subscripting array declared `register'");
2252 type = TREE_TYPE (TREE_TYPE (array));
2253 rval = build (ARRAY_REF, type, array, idx, NULL_TREE, NULL_TREE);
2254 /* Array ref is const/volatile if the array elements are
2255 or if the array is.. */
2256 TREE_READONLY (rval)
2257 |= (CP_TYPE_CONST_P (type) | TREE_READONLY (array));
2258 TREE_SIDE_EFFECTS (rval)
2259 |= (CP_TYPE_VOLATILE_P (type) | TREE_SIDE_EFFECTS (array));
2260 TREE_THIS_VOLATILE (rval)
2261 |= (CP_TYPE_VOLATILE_P (type) | TREE_THIS_VOLATILE (array));
2262 return require_complete_type (fold (rval));
2266 tree ar = default_conversion (array);
2267 tree ind = default_conversion (idx);
2269 /* Put the integer in IND to simplify error checking. */
2270 if (TREE_CODE (TREE_TYPE (ar)) == INTEGER_TYPE)
2277 if (ar == error_mark_node)
2280 if (TREE_CODE (TREE_TYPE (ar)) != POINTER_TYPE)
2282 error ("subscripted value is neither array nor pointer");
2283 return error_mark_node;
2285 if (TREE_CODE (TREE_TYPE (ind)) != INTEGER_TYPE)
2287 error ("array subscript is not an integer");
2288 return error_mark_node;
2291 return build_indirect_ref (cp_build_binary_op (PLUS_EXPR, ar, ind),
2296 /* Resolve a pointer to member function. INSTANCE is the object
2297 instance to use, if the member points to a virtual member.
2299 This used to avoid checking for virtual functions if basetype
2300 has no virtual functions, according to an earlier ANSI draft.
2301 With the final ISO C++ rules, such an optimization is
2302 incorrect: A pointer to a derived member can be static_cast
2303 to pointer-to-base-member, as long as the dynamic object
2304 later has the right member. */
2307 get_member_function_from_ptrfunc (tree *instance_ptrptr, tree function)
2309 if (TREE_CODE (function) == OFFSET_REF)
2310 function = TREE_OPERAND (function, 1);
2312 if (TYPE_PTRMEMFUNC_P (TREE_TYPE (function)))
2314 tree idx, delta, e1, e2, e3, vtbl, basetype;
2315 tree fntype = TYPE_PTRMEMFUNC_FN_TYPE (TREE_TYPE (function));
2317 tree instance_ptr = *instance_ptrptr;
2318 tree instance_save_expr = 0;
2319 if (instance_ptr == error_mark_node)
2321 if (TREE_CODE (function) == PTRMEM_CST)
2323 /* Extracting the function address from a pmf is only
2324 allowed with -Wno-pmf-conversions. It only works for
2326 e1 = build_addr_func (PTRMEM_CST_MEMBER (function));
2327 e1 = convert (fntype, e1);
2332 error ("object missing in use of `%E'", function);
2333 return error_mark_node;
2337 if (TREE_SIDE_EFFECTS (instance_ptr))
2338 instance_ptr = instance_save_expr = save_expr (instance_ptr);
2340 if (TREE_SIDE_EFFECTS (function))
2341 function = save_expr (function);
2343 /* Start by extracting all the information from the PMF itself. */
2344 e3 = PFN_FROM_PTRMEMFUNC (function);
2345 delta = build_ptrmemfunc_access_expr (function, delta_identifier);
2346 idx = build1 (NOP_EXPR, vtable_index_type, e3);
2347 switch (TARGET_PTRMEMFUNC_VBIT_LOCATION)
2349 case ptrmemfunc_vbit_in_pfn:
2350 e1 = cp_build_binary_op (BIT_AND_EXPR, idx, integer_one_node);
2351 idx = cp_build_binary_op (MINUS_EXPR, idx, integer_one_node);
2354 case ptrmemfunc_vbit_in_delta:
2355 e1 = cp_build_binary_op (BIT_AND_EXPR, delta, integer_one_node);
2356 delta = cp_build_binary_op (RSHIFT_EXPR, delta, integer_one_node);
2363 /* Convert down to the right base before using the instance. First
2365 basetype = TYPE_METHOD_BASETYPE (TREE_TYPE (fntype));
2366 basetype = lookup_base (TREE_TYPE (TREE_TYPE (instance_ptr)),
2367 basetype, ba_check, NULL);
2368 instance_ptr = build_base_path (PLUS_EXPR, instance_ptr, basetype, 1);
2369 if (instance_ptr == error_mark_node)
2370 return error_mark_node;
2371 /* ...and then the delta in the PMF. */
2372 instance_ptr = build (PLUS_EXPR, TREE_TYPE (instance_ptr),
2373 instance_ptr, delta);
2375 /* Hand back the adjusted 'this' argument to our caller. */
2376 *instance_ptrptr = instance_ptr;
2378 /* Next extract the vtable pointer from the object. */
2379 vtbl = build1 (NOP_EXPR, build_pointer_type (vtbl_ptr_type_node),
2381 vtbl = build_indirect_ref (vtbl, NULL);
2383 /* Finally, extract the function pointer from the vtable. */
2384 e2 = fold (build (PLUS_EXPR, TREE_TYPE (vtbl), vtbl, idx));
2385 e2 = build_indirect_ref (e2, NULL);
2386 TREE_CONSTANT (e2) = 1;
2387 TREE_INVARIANT (e2) = 1;
2389 /* When using function descriptors, the address of the
2390 vtable entry is treated as a function pointer. */
2391 if (TARGET_VTABLE_USES_DESCRIPTORS)
2392 e2 = build1 (NOP_EXPR, TREE_TYPE (e2),
2393 build_unary_op (ADDR_EXPR, e2, /*noconvert=*/1));
2395 TREE_TYPE (e2) = TREE_TYPE (e3);
2396 e1 = build_conditional_expr (e1, e2, e3);
2398 /* Make sure this doesn't get evaluated first inside one of the
2399 branches of the COND_EXPR. */
2400 if (instance_save_expr)
2401 e1 = build (COMPOUND_EXPR, TREE_TYPE (e1),
2402 instance_save_expr, e1);
2410 build_function_call (tree function, tree params)
2412 tree fntype, fndecl;
2413 tree coerced_params;
2414 tree name = NULL_TREE;
2416 tree original = function;
2418 /* build_c_cast puts on a NOP_EXPR to make the result not an lvalue.
2419 Strip such NOP_EXPRs, since FUNCTION is used in non-lvalue context. */
2420 if (TREE_CODE (function) == NOP_EXPR
2421 && TREE_TYPE (function) == TREE_TYPE (TREE_OPERAND (function, 0)))
2422 function = TREE_OPERAND (function, 0);
2424 if (TREE_CODE (function) == FUNCTION_DECL)
2426 name = DECL_NAME (function);
2428 mark_used (function);
2431 /* Convert anything with function type to a pointer-to-function. */
2432 if (pedantic && DECL_MAIN_P (function))
2433 pedwarn ("ISO C++ forbids calling `::main' from within program");
2435 /* Differs from default_conversion by not setting TREE_ADDRESSABLE
2436 (because calling an inline function does not mean the function
2437 needs to be separately compiled). */
2439 if (DECL_INLINE (function))
2440 function = inline_conversion (function);
2442 function = build_addr_func (function);
2448 function = build_addr_func (function);
2451 if (function == error_mark_node)
2452 return error_mark_node;
2454 fntype = TREE_TYPE (function);
2456 if (TYPE_PTRMEMFUNC_P (fntype))
2458 error ("must use .* or ->* to call pointer-to-member function in `%E (...)'",
2460 return error_mark_node;
2463 is_method = (TREE_CODE (fntype) == POINTER_TYPE
2464 && TREE_CODE (TREE_TYPE (fntype)) == METHOD_TYPE);
2466 if (!((TREE_CODE (fntype) == POINTER_TYPE
2467 && TREE_CODE (TREE_TYPE (fntype)) == FUNCTION_TYPE)
2469 || TREE_CODE (function) == TEMPLATE_ID_EXPR))
2471 error ("`%E' cannot be used as a function", original);
2472 return error_mark_node;
2475 /* fntype now gets the type of function pointed to. */
2476 fntype = TREE_TYPE (fntype);
2478 /* Convert the parameters to the types declared in the
2479 function prototype, or apply default promotions. */
2481 coerced_params = convert_arguments (TYPE_ARG_TYPES (fntype),
2482 params, fndecl, LOOKUP_NORMAL);
2483 if (coerced_params == error_mark_node)
2484 return error_mark_node;
2486 /* Check for errors in format strings. */
2489 check_function_format (NULL, TYPE_ATTRIBUTES (fntype), coerced_params);
2491 return build_cxx_call (function, coerced_params);
2494 /* Convert the actual parameter expressions in the list VALUES
2495 to the types in the list TYPELIST.
2496 If parmdecls is exhausted, or when an element has NULL as its type,
2497 perform the default conversions.
2499 NAME is an IDENTIFIER_NODE or 0. It is used only for error messages.
2501 This is also where warnings about wrong number of args are generated.
2503 Return a list of expressions for the parameters as converted.
2505 Both VALUES and the returned value are chains of TREE_LIST nodes
2506 with the elements of the list in the TREE_VALUE slots of those nodes.
2508 In C++, unspecified trailing parameters can be filled in with their
2509 default arguments, if such were specified. Do so here. */
2512 convert_arguments (tree typelist, tree values, tree fndecl, int flags)
2514 tree typetail, valtail;
2515 tree result = NULL_TREE;
2516 const char *called_thing = 0;
2519 /* Argument passing is always copy-initialization. */
2520 flags |= LOOKUP_ONLYCONVERTING;
2524 if (TREE_CODE (TREE_TYPE (fndecl)) == METHOD_TYPE)
2526 if (DECL_NAME (fndecl) == NULL_TREE
2527 || IDENTIFIER_HAS_TYPE_VALUE (DECL_NAME (fndecl)))
2528 called_thing = "constructor";
2530 called_thing = "member function";
2533 called_thing = "function";
2536 for (valtail = values, typetail = typelist;
2538 valtail = TREE_CHAIN (valtail), i++)
2540 tree type = typetail ? TREE_VALUE (typetail) : 0;
2541 tree val = TREE_VALUE (valtail);
2543 if (val == error_mark_node)
2544 return error_mark_node;
2546 if (type == void_type_node)
2550 cp_error_at ("too many arguments to %s `%+#D'", called_thing,
2552 error ("at this point in file");
2555 error ("too many arguments to function");
2556 /* In case anybody wants to know if this argument
2559 TREE_TYPE (tree_last (result)) = error_mark_node;
2563 /* build_c_cast puts on a NOP_EXPR to make the result not an lvalue.
2564 Strip such NOP_EXPRs, since VAL is used in non-lvalue context. */
2565 if (TREE_CODE (val) == NOP_EXPR
2566 && TREE_TYPE (val) == TREE_TYPE (TREE_OPERAND (val, 0))
2567 && (type == 0 || TREE_CODE (type) != REFERENCE_TYPE))
2568 val = TREE_OPERAND (val, 0);
2570 if (type == 0 || TREE_CODE (type) != REFERENCE_TYPE)
2572 if (TREE_CODE (TREE_TYPE (val)) == ARRAY_TYPE
2573 || TREE_CODE (TREE_TYPE (val)) == FUNCTION_TYPE
2574 || TREE_CODE (TREE_TYPE (val)) == METHOD_TYPE)
2575 val = decay_conversion (val);
2578 if (val == error_mark_node)
2579 return error_mark_node;
2583 /* Formal parm type is specified by a function prototype. */
2586 if (!COMPLETE_TYPE_P (complete_type (type)))
2589 error ("parameter %P of `%D' has incomplete type `%T'",
2592 error ("parameter %P has incomplete type `%T'", i, type);
2593 parmval = error_mark_node;
2597 parmval = convert_for_initialization
2598 (NULL_TREE, type, val, flags,
2599 "argument passing", fndecl, i);
2600 parmval = convert_for_arg_passing (type, parmval);
2603 if (parmval == error_mark_node)
2604 return error_mark_node;
2606 result = tree_cons (NULL_TREE, parmval, result);
2610 if (TREE_CODE (TREE_TYPE (val)) == REFERENCE_TYPE)
2611 val = convert_from_reference (val);
2613 if (fndecl && DECL_BUILT_IN (fndecl)
2614 && DECL_FUNCTION_CODE (fndecl) == BUILT_IN_CONSTANT_P)
2615 /* Don't do ellipsis conversion for __built_in_constant_p
2616 as this will result in spurious warnings for non-POD
2618 val = require_complete_type (val);
2620 val = convert_arg_to_ellipsis (val);
2622 result = tree_cons (NULL_TREE, val, result);
2626 typetail = TREE_CHAIN (typetail);
2629 if (typetail != 0 && typetail != void_list_node)
2631 /* See if there are default arguments that can be used. */
2632 if (TREE_PURPOSE (typetail)
2633 && TREE_CODE (TREE_PURPOSE (typetail)) != DEFAULT_ARG)
2635 for (; typetail != void_list_node; ++i)
2638 = convert_default_arg (TREE_VALUE (typetail),
2639 TREE_PURPOSE (typetail),
2642 if (parmval == error_mark_node)
2643 return error_mark_node;
2645 result = tree_cons (0, parmval, result);
2646 typetail = TREE_CHAIN (typetail);
2647 /* ends with `...'. */
2648 if (typetail == NULL_TREE)
2656 cp_error_at ("too few arguments to %s `%+#D'",
2657 called_thing, fndecl);
2658 error ("at this point in file");
2661 error ("too few arguments to function");
2662 return error_mark_list;
2666 return nreverse (result);
2669 /* Build a binary-operation expression, after performing default
2670 conversions on the operands. CODE is the kind of expression to build. */
2673 build_x_binary_op (enum tree_code code, tree arg1, tree arg2,
2683 if (processing_template_decl)
2685 if (type_dependent_expression_p (arg1)
2686 || type_dependent_expression_p (arg2))
2687 return build_min_nt (code, arg1, arg2);
2688 arg1 = build_non_dependent_expr (arg1);
2689 arg2 = build_non_dependent_expr (arg2);
2692 if (code == DOTSTAR_EXPR)
2693 expr = build_m_component_ref (arg1, arg2);
2695 expr = build_new_op (code, LOOKUP_NORMAL, arg1, arg2, NULL_TREE,
2698 if (processing_template_decl && expr != error_mark_node)
2699 return build_min_non_dep (code, expr, orig_arg1, orig_arg2);
2704 /* Build a binary-operation expression without default conversions.
2705 CODE is the kind of expression to build.
2706 This function differs from `build' in several ways:
2707 the data type of the result is computed and recorded in it,
2708 warnings are generated if arg data types are invalid,
2709 special handling for addition and subtraction of pointers is known,
2710 and some optimization is done (operations on narrow ints
2711 are done in the narrower type when that gives the same result).
2712 Constant folding is also done before the result is returned.
2714 Note that the operands will never have enumeral types
2715 because either they have just had the default conversions performed
2716 or they have both just been converted to some other type in which
2717 the arithmetic is to be done.
2719 C++: must do special pointer arithmetic when implementing
2720 multiple inheritance, and deal with pointer to member functions. */
2723 build_binary_op (enum tree_code code, tree orig_op0, tree orig_op1,
2724 int convert_p ATTRIBUTE_UNUSED)
2727 enum tree_code code0, code1;
2730 /* Expression code to give to the expression when it is built.
2731 Normally this is CODE, which is what the caller asked for,
2732 but in some special cases we change it. */
2733 enum tree_code resultcode = code;
2735 /* Data type in which the computation is to be performed.
2736 In the simplest cases this is the common type of the arguments. */
2737 tree result_type = NULL;
2739 /* Nonzero means operands have already been type-converted
2740 in whatever way is necessary.
2741 Zero means they need to be converted to RESULT_TYPE. */
2744 /* Nonzero means create the expression with this type, rather than
2746 tree build_type = 0;
2748 /* Nonzero means after finally constructing the expression
2749 convert it to this type. */
2750 tree final_type = 0;
2752 /* Nonzero if this is an operation like MIN or MAX which can
2753 safely be computed in short if both args are promoted shorts.
2754 Also implies COMMON.
2755 -1 indicates a bitwise operation; this makes a difference
2756 in the exact conditions for when it is safe to do the operation
2757 in a narrower mode. */
2760 /* Nonzero if this is a comparison operation;
2761 if both args are promoted shorts, compare the original shorts.
2762 Also implies COMMON. */
2763 int short_compare = 0;
2765 /* Nonzero if this is a right-shift operation, which can be computed on the
2766 original short and then promoted if the operand is a promoted short. */
2767 int short_shift = 0;
2769 /* Nonzero means set RESULT_TYPE to the common type of the args. */
2772 /* Apply default conversions. */
2776 if (code == TRUTH_AND_EXPR || code == TRUTH_ANDIF_EXPR
2777 || code == TRUTH_OR_EXPR || code == TRUTH_ORIF_EXPR
2778 || code == TRUTH_XOR_EXPR)
2780 if (!really_overloaded_fn (op0))
2781 op0 = decay_conversion (op0);
2782 if (!really_overloaded_fn (op1))
2783 op1 = decay_conversion (op1);
2787 if (!really_overloaded_fn (op0))
2788 op0 = default_conversion (op0);
2789 if (!really_overloaded_fn (op1))
2790 op1 = default_conversion (op1);
2793 /* Strip NON_LVALUE_EXPRs, etc., since we aren't using as an lvalue. */
2794 STRIP_TYPE_NOPS (op0);
2795 STRIP_TYPE_NOPS (op1);
2797 /* DTRT if one side is an overloaded function, but complain about it. */
2798 if (type_unknown_p (op0))
2800 tree t = instantiate_type (TREE_TYPE (op1), op0, tf_none);
2801 if (t != error_mark_node)
2803 pedwarn ("assuming cast to type `%T' from overloaded function",
2808 if (type_unknown_p (op1))
2810 tree t = instantiate_type (TREE_TYPE (op0), op1, tf_none);
2811 if (t != error_mark_node)
2813 pedwarn ("assuming cast to type `%T' from overloaded function",
2819 type0 = TREE_TYPE (op0);
2820 type1 = TREE_TYPE (op1);
2822 /* The expression codes of the data types of the arguments tell us
2823 whether the arguments are integers, floating, pointers, etc. */
2824 code0 = TREE_CODE (type0);
2825 code1 = TREE_CODE (type1);
2827 /* If an error was already reported for one of the arguments,
2828 avoid reporting another error. */
2830 if (code0 == ERROR_MARK || code1 == ERROR_MARK)
2831 return error_mark_node;
2836 /* Handle the pointer + int case. */
2837 if (code0 == POINTER_TYPE && code1 == INTEGER_TYPE)
2838 return cp_pointer_int_sum (PLUS_EXPR, op0, op1);
2839 else if (code1 == POINTER_TYPE && code0 == INTEGER_TYPE)
2840 return cp_pointer_int_sum (PLUS_EXPR, op1, op0);
2846 /* Subtraction of two similar pointers.
2847 We must subtract them as integers, then divide by object size. */
2848 if (code0 == POINTER_TYPE && code1 == POINTER_TYPE
2849 && same_type_ignoring_top_level_qualifiers_p (TREE_TYPE (type0),
2851 return pointer_diff (op0, op1, common_type (type0, type1));
2852 /* Handle pointer minus int. Just like pointer plus int. */
2853 else if (code0 == POINTER_TYPE && code1 == INTEGER_TYPE)
2854 return cp_pointer_int_sum (MINUS_EXPR, op0, op1);
2863 case TRUNC_DIV_EXPR:
2865 case FLOOR_DIV_EXPR:
2866 case ROUND_DIV_EXPR:
2867 case EXACT_DIV_EXPR:
2868 if ((code0 == INTEGER_TYPE || code0 == REAL_TYPE
2869 || code0 == COMPLEX_TYPE)
2870 && (code1 == INTEGER_TYPE || code1 == REAL_TYPE
2871 || code1 == COMPLEX_TYPE))
2873 if (TREE_CODE (op1) == INTEGER_CST && integer_zerop (op1))
2874 warning ("division by zero in `%E / 0'", op0);
2875 else if (TREE_CODE (op1) == REAL_CST && real_zerop (op1))
2876 warning ("division by zero in `%E / 0.'", op0);
2878 if (!(code0 == INTEGER_TYPE && code1 == INTEGER_TYPE))
2879 resultcode = RDIV_EXPR;
2881 /* When dividing two signed integers, we have to promote to int.
2882 unless we divide by a constant != -1. Note that default
2883 conversion will have been performed on the operands at this
2884 point, so we have to dig out the original type to find out if
2886 shorten = ((TREE_CODE (op0) == NOP_EXPR
2887 && TYPE_UNSIGNED (TREE_TYPE (TREE_OPERAND (op0, 0))))
2888 || (TREE_CODE (op1) == INTEGER_CST
2889 && ! integer_all_onesp (op1)));
2898 if (code0 == INTEGER_TYPE && code1 == INTEGER_TYPE)
2902 case TRUNC_MOD_EXPR:
2903 case FLOOR_MOD_EXPR:
2904 if (code1 == INTEGER_TYPE && integer_zerop (op1))
2905 warning ("division by zero in `%E %% 0'", op0);
2906 else if (code1 == REAL_TYPE && real_zerop (op1))
2907 warning ("division by zero in `%E %% 0.'", op0);
2909 if (code0 == INTEGER_TYPE && code1 == INTEGER_TYPE)
2911 /* Although it would be tempting to shorten always here, that loses
2912 on some targets, since the modulo instruction is undefined if the
2913 quotient can't be represented in the computation mode. We shorten
2914 only if unsigned or if dividing by something we know != -1. */
2915 shorten = ((TREE_CODE (op0) == NOP_EXPR
2916 && TYPE_UNSIGNED (TREE_TYPE (TREE_OPERAND (op0, 0))))
2917 || (TREE_CODE (op1) == INTEGER_CST
2918 && ! integer_all_onesp (op1)));
2923 case TRUTH_ANDIF_EXPR:
2924 case TRUTH_ORIF_EXPR:
2925 case TRUTH_AND_EXPR:
2927 result_type = boolean_type_node;
2930 /* Shift operations: result has same type as first operand;
2931 always convert second operand to int.
2932 Also set SHORT_SHIFT if shifting rightward. */
2935 if (code0 == INTEGER_TYPE && code1 == INTEGER_TYPE)
2937 result_type = type0;
2938 if (TREE_CODE (op1) == INTEGER_CST)
2940 if (tree_int_cst_lt (op1, integer_zero_node))
2941 warning ("right shift count is negative");
2944 if (! integer_zerop (op1))
2946 if (compare_tree_int (op1, TYPE_PRECISION (type0)) >= 0)
2947 warning ("right shift count >= width of type");
2950 /* Convert the shift-count to an integer, regardless of
2951 size of value being shifted. */
2952 if (TYPE_MAIN_VARIANT (TREE_TYPE (op1)) != integer_type_node)
2953 op1 = cp_convert (integer_type_node, op1);
2954 /* Avoid converting op1 to result_type later. */
2960 if (code0 == INTEGER_TYPE && code1 == INTEGER_TYPE)
2962 result_type = type0;
2963 if (TREE_CODE (op1) == INTEGER_CST)
2965 if (tree_int_cst_lt (op1, integer_zero_node))
2966 warning ("left shift count is negative");
2967 else if (compare_tree_int (op1, TYPE_PRECISION (type0)) >= 0)
2968 warning ("left 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. */
2981 if (code0 == INTEGER_TYPE && code1 == INTEGER_TYPE)
2983 result_type = type0;
2984 if (TREE_CODE (op1) == INTEGER_CST)
2986 if (tree_int_cst_lt (op1, integer_zero_node))
2987 warning ("%s rotate count is negative",
2988 (code == LROTATE_EXPR) ? "left" : "right");
2989 else if (compare_tree_int (op1, TYPE_PRECISION (type0)) >= 0)
2990 warning ("%s rotate count >= width of type",
2991 (code == LROTATE_EXPR) ? "left" : "right");
2993 /* Convert the shift-count to an integer, regardless of
2994 size of value being shifted. */
2995 if (TYPE_MAIN_VARIANT (TREE_TYPE (op1)) != integer_type_node)
2996 op1 = cp_convert (integer_type_node, op1);
3002 if (warn_float_equal && (code0 == REAL_TYPE || code1 == REAL_TYPE))
3003 warning ("comparing floating point with == or != is unsafe");
3005 build_type = boolean_type_node;
3006 if ((code0 == INTEGER_TYPE || code0 == REAL_TYPE
3007 || code0 == COMPLEX_TYPE)
3008 && (code1 == INTEGER_TYPE || code1 == REAL_TYPE
3009 || code1 == COMPLEX_TYPE))
3011 else if ((code0 == POINTER_TYPE && code1 == POINTER_TYPE)
3012 || (TYPE_PTRMEM_P (type0) && TYPE_PTRMEM_P (type1)))
3013 result_type = composite_pointer_type (type0, type1, op0, op1,
3015 else if ((code0 == POINTER_TYPE || TYPE_PTRMEM_P (type0))
3016 && null_ptr_cst_p (op1))
3017 result_type = type0;
3018 else if ((code1 == POINTER_TYPE || TYPE_PTRMEM_P (type1))
3019 && null_ptr_cst_p (op0))
3020 result_type = type1;
3021 else if (code0 == POINTER_TYPE && code1 == INTEGER_TYPE)
3023 result_type = type0;
3024 error ("ISO C++ forbids comparison between pointer and integer");
3026 else if (code0 == INTEGER_TYPE && code1 == POINTER_TYPE)
3028 result_type = type1;
3029 error ("ISO C++ forbids comparison between pointer and integer");
3031 else if (TYPE_PTRMEMFUNC_P (type0) && null_ptr_cst_p (op1))
3033 op0 = build_ptrmemfunc_access_expr (op0, pfn_identifier);
3034 op1 = cp_convert (TREE_TYPE (op0), integer_zero_node);
3035 result_type = TREE_TYPE (op0);
3037 else if (TYPE_PTRMEMFUNC_P (type1) && null_ptr_cst_p (op0))
3038 return cp_build_binary_op (code, op1, op0);
3039 else if (TYPE_PTRMEMFUNC_P (type0) && TYPE_PTRMEMFUNC_P (type1)
3040 && same_type_p (type0, type1))
3042 /* E will be the final comparison. */
3044 /* E1 and E2 are for scratch. */
3052 if (TREE_SIDE_EFFECTS (op0))
3053 op0 = save_expr (op0);
3054 if (TREE_SIDE_EFFECTS (op1))
3055 op1 = save_expr (op1);
3060 && (!op0.pfn || op0.delta == op1.delta))
3062 The reason for the `!op0.pfn' bit is that a NULL
3063 pointer-to-member is any member with a zero PFN; the
3064 DELTA field is unspecified. */
3065 pfn0 = pfn_from_ptrmemfunc (op0);
3066 pfn1 = pfn_from_ptrmemfunc (op1);
3067 delta0 = build_ptrmemfunc_access_expr (op0,
3069 delta1 = build_ptrmemfunc_access_expr (op1,
3071 e1 = cp_build_binary_op (EQ_EXPR, delta0, delta1);
3072 e2 = cp_build_binary_op (EQ_EXPR,
3074 cp_convert (TREE_TYPE (pfn0),
3075 integer_zero_node));
3076 e1 = cp_build_binary_op (TRUTH_ORIF_EXPR, e1, e2);
3077 e2 = build (EQ_EXPR, boolean_type_node, pfn0, pfn1);
3078 e = cp_build_binary_op (TRUTH_ANDIF_EXPR, e2, e1);
3079 if (code == EQ_EXPR)
3081 return cp_build_binary_op (EQ_EXPR, e, integer_zero_node);
3083 else if ((TYPE_PTRMEMFUNC_P (type0)
3084 && same_type_p (TYPE_PTRMEMFUNC_FN_TYPE (type0), type1))
3085 || (TYPE_PTRMEMFUNC_P (type1)
3086 && same_type_p (TYPE_PTRMEMFUNC_FN_TYPE (type1), type0)))
3092 if ((code0 == INTEGER_TYPE || code0 == REAL_TYPE)
3093 && (code1 == INTEGER_TYPE || code1 == REAL_TYPE))
3095 else if (code0 == POINTER_TYPE && code1 == POINTER_TYPE)
3096 result_type = composite_pointer_type (type0, type1, op0, op1,
3104 build_type = boolean_type_node;
3105 if ((code0 == INTEGER_TYPE || code0 == REAL_TYPE)
3106 && (code1 == INTEGER_TYPE || code1 == REAL_TYPE))
3108 else if (code0 == POINTER_TYPE && code1 == POINTER_TYPE)
3109 result_type = composite_pointer_type (type0, type1, op0, op1,
3111 else if (code0 == POINTER_TYPE && TREE_CODE (op1) == INTEGER_CST
3112 && integer_zerop (op1))
3113 result_type = type0;
3114 else if (code1 == POINTER_TYPE && TREE_CODE (op0) == INTEGER_CST
3115 && integer_zerop (op0))
3116 result_type = type1;
3117 else if (code0 == POINTER_TYPE && code1 == INTEGER_TYPE)
3119 result_type = type0;
3120 pedwarn ("ISO C++ forbids comparison between pointer and integer");
3122 else if (code0 == INTEGER_TYPE && code1 == POINTER_TYPE)
3124 result_type = type1;
3125 pedwarn ("ISO C++ forbids comparison between pointer and integer");
3129 case UNORDERED_EXPR:
3136 build_type = integer_type_node;
3137 if (code0 != REAL_TYPE || code1 != REAL_TYPE)
3139 error ("unordered comparison on non-floating point argument");
3140 return error_mark_node;
3149 if ((code0 == INTEGER_TYPE || code0 == REAL_TYPE || code0 == COMPLEX_TYPE)
3151 (code1 == INTEGER_TYPE || code1 == REAL_TYPE || code1 == COMPLEX_TYPE))
3153 int none_complex = (code0 != COMPLEX_TYPE && code1 != COMPLEX_TYPE);
3155 if (shorten || common || short_compare)
3156 result_type = common_type (type0, type1);
3158 /* For certain operations (which identify themselves by shorten != 0)
3159 if both args were extended from the same smaller type,
3160 do the arithmetic in that type and then extend.
3162 shorten !=0 and !=1 indicates a bitwise operation.
3163 For them, this optimization is safe only if
3164 both args are zero-extended or both are sign-extended.
3165 Otherwise, we might change the result.
3166 Eg, (short)-1 | (unsigned short)-1 is (int)-1
3167 but calculated in (unsigned short) it would be (unsigned short)-1. */
3169 if (shorten && none_complex)
3171 int unsigned0, unsigned1;
3172 tree arg0 = get_narrower (op0, &unsigned0);
3173 tree arg1 = get_narrower (op1, &unsigned1);
3174 /* UNS is 1 if the operation to be done is an unsigned one. */
3175 int uns = TYPE_UNSIGNED (result_type);
3178 final_type = result_type;
3180 /* Handle the case that OP0 does not *contain* a conversion
3181 but it *requires* conversion to FINAL_TYPE. */
3183 if (op0 == arg0 && TREE_TYPE (op0) != final_type)
3184 unsigned0 = TYPE_UNSIGNED (TREE_TYPE (op0));
3185 if (op1 == arg1 && TREE_TYPE (op1) != final_type)
3186 unsigned1 = TYPE_UNSIGNED (TREE_TYPE (op1));
3188 /* Now UNSIGNED0 is 1 if ARG0 zero-extends to FINAL_TYPE. */
3190 /* For bitwise operations, signedness of nominal type
3191 does not matter. Consider only how operands were extended. */
3195 /* Note that in all three cases below we refrain from optimizing
3196 an unsigned operation on sign-extended args.
3197 That would not be valid. */
3199 /* Both args variable: if both extended in same way
3200 from same width, do it in that width.
3201 Do it unsigned if args were zero-extended. */
3202 if ((TYPE_PRECISION (TREE_TYPE (arg0))
3203 < TYPE_PRECISION (result_type))
3204 && (TYPE_PRECISION (TREE_TYPE (arg1))
3205 == TYPE_PRECISION (TREE_TYPE (arg0)))
3206 && unsigned0 == unsigned1
3207 && (unsigned0 || !uns))
3208 result_type = c_common_signed_or_unsigned_type
3209 (unsigned0, common_type (TREE_TYPE (arg0), TREE_TYPE (arg1)));
3210 else if (TREE_CODE (arg0) == INTEGER_CST
3211 && (unsigned1 || !uns)
3212 && (TYPE_PRECISION (TREE_TYPE (arg1))
3213 < TYPE_PRECISION (result_type))
3214 && (type = c_common_signed_or_unsigned_type
3215 (unsigned1, TREE_TYPE (arg1)),
3216 int_fits_type_p (arg0, type)))
3218 else if (TREE_CODE (arg1) == INTEGER_CST
3219 && (unsigned0 || !uns)
3220 && (TYPE_PRECISION (TREE_TYPE (arg0))
3221 < TYPE_PRECISION (result_type))
3222 && (type = c_common_signed_or_unsigned_type
3223 (unsigned0, TREE_TYPE (arg0)),
3224 int_fits_type_p (arg1, type)))
3228 /* Shifts can be shortened if shifting right. */
3233 tree arg0 = get_narrower (op0, &unsigned_arg);
3235 final_type = result_type;
3237 if (arg0 == op0 && final_type == TREE_TYPE (op0))
3238 unsigned_arg = TYPE_UNSIGNED (TREE_TYPE (op0));
3240 if (TYPE_PRECISION (TREE_TYPE (arg0)) < TYPE_PRECISION (result_type)
3241 /* We can shorten only if the shift count is less than the
3242 number of bits in the smaller type size. */
3243 && compare_tree_int (op1, TYPE_PRECISION (TREE_TYPE (arg0))) < 0
3244 /* If arg is sign-extended and then unsigned-shifted,
3245 we can simulate this with a signed shift in arg's type
3246 only if the extended result is at least twice as wide
3247 as the arg. Otherwise, the shift could use up all the
3248 ones made by sign-extension and bring in zeros.
3249 We can't optimize that case at all, but in most machines
3250 it never happens because available widths are 2**N. */
3251 && (!TYPE_UNSIGNED (final_type)
3253 || (((unsigned) 2 * TYPE_PRECISION (TREE_TYPE (arg0)))
3254 <= TYPE_PRECISION (result_type))))
3256 /* Do an unsigned shift if the operand was zero-extended. */
3258 = c_common_signed_or_unsigned_type (unsigned_arg,
3260 /* Convert value-to-be-shifted to that type. */
3261 if (TREE_TYPE (op0) != result_type)
3262 op0 = cp_convert (result_type, op0);
3267 /* Comparison operations are shortened too but differently.
3268 They identify themselves by setting short_compare = 1. */
3272 /* Don't write &op0, etc., because that would prevent op0
3273 from being kept in a register.
3274 Instead, make copies of the our local variables and
3275 pass the copies by reference, then copy them back afterward. */
3276 tree xop0 = op0, xop1 = op1, xresult_type = result_type;
3277 enum tree_code xresultcode = resultcode;
3279 = shorten_compare (&xop0, &xop1, &xresult_type, &xresultcode);
3281 return cp_convert (boolean_type_node, val);
3282 op0 = xop0, op1 = xop1;
3284 resultcode = xresultcode;
3287 if ((short_compare || code == MIN_EXPR || code == MAX_EXPR)
3288 && warn_sign_compare
3289 /* Do not warn until the template is instantiated; we cannot
3290 bound the ranges of the arguments until that point. */
3291 && !processing_template_decl)
3293 int op0_signed = !TYPE_UNSIGNED (TREE_TYPE (orig_op0));
3294 int op1_signed = !TYPE_UNSIGNED (TREE_TYPE (orig_op1));
3296 int unsignedp0, unsignedp1;
3297 tree primop0 = get_narrower (op0, &unsignedp0);
3298 tree primop1 = get_narrower (op1, &unsignedp1);
3300 /* Check for comparison of different enum types. */
3301 if (TREE_CODE (TREE_TYPE (orig_op0)) == ENUMERAL_TYPE
3302 && TREE_CODE (TREE_TYPE (orig_op1)) == ENUMERAL_TYPE
3303 && TYPE_MAIN_VARIANT (TREE_TYPE (orig_op0))
3304 != TYPE_MAIN_VARIANT (TREE_TYPE (orig_op1)))
3306 warning ("comparison between types `%#T' and `%#T'",
3307 TREE_TYPE (orig_op0), TREE_TYPE (orig_op1));
3310 /* Give warnings for comparisons between signed and unsigned
3311 quantities that may fail. */
3312 /* Do the checking based on the original operand trees, so that
3313 casts will be considered, but default promotions won't be. */
3315 /* Do not warn if the comparison is being done in a signed type,
3316 since the signed type will only be chosen if it can represent
3317 all the values of the unsigned type. */
3318 if (!TYPE_UNSIGNED (result_type))
3320 /* Do not warn if both operands are unsigned. */
3321 else if (op0_signed == op1_signed)
3323 /* Do not warn if the signed quantity is an unsuffixed
3324 integer literal (or some static constant expression
3325 involving such literals or a conditional expression
3326 involving such literals) and it is non-negative. */
3327 else if ((op0_signed && tree_expr_nonnegative_p (orig_op0))
3328 || (op1_signed && tree_expr_nonnegative_p (orig_op1)))
3330 /* Do not warn if the comparison is an equality operation,
3331 the unsigned quantity is an integral constant and it does
3332 not use the most significant bit of result_type. */
3333 else if ((resultcode == EQ_EXPR || resultcode == NE_EXPR)
3334 && ((op0_signed && TREE_CODE (orig_op1) == INTEGER_CST
3335 && int_fits_type_p (orig_op1, c_common_signed_type
3337 || (op1_signed && TREE_CODE (orig_op0) == INTEGER_CST
3338 && int_fits_type_p (orig_op0, c_common_signed_type
3342 warning ("comparison between signed and unsigned integer expressions");
3344 /* Warn if two unsigned values are being compared in a size
3345 larger than their original size, and one (and only one) is the
3346 result of a `~' operator. This comparison will always fail.
3348 Also warn if one operand is a constant, and the constant does not
3349 have all bits set that are set in the ~ operand when it is
3352 if ((TREE_CODE (primop0) == BIT_NOT_EXPR)
3353 ^ (TREE_CODE (primop1) == BIT_NOT_EXPR))
3355 if (TREE_CODE (primop0) == BIT_NOT_EXPR)
3356 primop0 = get_narrower (TREE_OPERAND (op0, 0), &unsignedp0);
3357 if (TREE_CODE (primop1) == BIT_NOT_EXPR)
3358 primop1 = get_narrower (TREE_OPERAND (op1, 0), &unsignedp1);
3360 if (host_integerp (primop0, 0) || host_integerp (primop1, 0))
3363 HOST_WIDE_INT constant, mask;
3367 if (host_integerp (primop0, 0))
3370 unsignedp = unsignedp1;
3371 constant = tree_low_cst (primop0, 0);
3376 unsignedp = unsignedp0;
3377 constant = tree_low_cst (primop1, 0);
3380 bits = TYPE_PRECISION (TREE_TYPE (primop));
3381 if (bits < TYPE_PRECISION (result_type)
3382 && bits < HOST_BITS_PER_LONG && unsignedp)
3384 mask = (~ (HOST_WIDE_INT) 0) << bits;
3385 if ((mask & constant) != mask)
3386 warning ("comparison of promoted ~unsigned with constant");
3389 else if (unsignedp0 && unsignedp1
3390 && (TYPE_PRECISION (TREE_TYPE (primop0))
3391 < TYPE_PRECISION (result_type))
3392 && (TYPE_PRECISION (TREE_TYPE (primop1))
3393 < TYPE_PRECISION (result_type)))
3394 warning ("comparison of promoted ~unsigned with unsigned");
3399 /* At this point, RESULT_TYPE must be nonzero to avoid an error message.
3400 If CONVERTED is zero, both args will be converted to type RESULT_TYPE.
3401 Then the expression will be built.
3402 It will be given type FINAL_TYPE if that is nonzero;
3403 otherwise, it will be given type RESULT_TYPE. */
3407 error ("invalid operands of types `%T' and `%T' to binary `%O'",
3408 TREE_TYPE (orig_op0), TREE_TYPE (orig_op1), code);
3409 return error_mark_node;
3412 /* Issue warnings about peculiar, but valid, uses of NULL. */
3413 if (/* It's reasonable to use pointer values as operands of &&
3414 and ||, so NULL is no exception. */
3415 !(code == TRUTH_ANDIF_EXPR || code == TRUTH_ORIF_EXPR)
3416 && (/* If OP0 is NULL and OP1 is not a pointer, or vice versa. */
3417 (orig_op0 == null_node
3418 && TREE_CODE (TREE_TYPE (op1)) != POINTER_TYPE)
3419 /* Or vice versa. */
3420 || (orig_op1 == null_node
3421 && TREE_CODE (TREE_TYPE (op0)) != POINTER_TYPE)
3422 /* Or, both are NULL and the operation was not a comparison. */
3423 || (orig_op0 == null_node && orig_op1 == null_node
3424 && code != EQ_EXPR && code != NE_EXPR)))
3425 /* Some sort of arithmetic operation involving NULL was
3426 performed. Note that pointer-difference and pointer-addition
3427 have already been handled above, and so we don't end up here in
3429 warning ("NULL used in arithmetic");
3433 if (TREE_TYPE (op0) != result_type)
3434 op0 = cp_convert (result_type, op0);
3435 if (TREE_TYPE (op1) != result_type)
3436 op1 = cp_convert (result_type, op1);
3438 if (op0 == error_mark_node || op1 == error_mark_node)
3439 return error_mark_node;
3442 if (build_type == NULL_TREE)
3443 build_type = result_type;
3446 tree result = fold (build (resultcode, build_type, op0, op1));
3447 if (final_type != 0)
3448 result = cp_convert (final_type, result);
3453 /* Return a tree for the sum or difference (RESULTCODE says which)
3454 of pointer PTROP and integer INTOP. */
3457 cp_pointer_int_sum (enum tree_code resultcode, tree ptrop, tree intop)
3459 tree res_type = TREE_TYPE (ptrop);
3461 /* pointer_int_sum() uses size_in_bytes() on the TREE_TYPE(res_type)
3462 in certain circumstance (when it's valid to do so). So we need
3463 to make sure it's complete. We don't need to check here, if we
3464 can actually complete it at all, as those checks will be done in
3465 pointer_int_sum() anyway. */
3466 complete_type (TREE_TYPE (res_type));
3468 return pointer_int_sum (resultcode, ptrop, fold (intop));
3471 /* Return a tree for the difference of pointers OP0 and OP1.
3472 The resulting tree has type int. */
3475 pointer_diff (tree op0, tree op1, tree ptrtype)
3478 tree restype = ptrdiff_type_node;
3479 tree target_type = TREE_TYPE (ptrtype);
3481 if (!complete_type_or_else (target_type, NULL_TREE))
3482 return error_mark_node;
3484 if (pedantic || warn_pointer_arith)
3486 if (TREE_CODE (target_type) == VOID_TYPE)
3487 pedwarn ("ISO C++ forbids using pointer of type `void *' in subtraction");
3488 if (TREE_CODE (target_type) == FUNCTION_TYPE)
3489 pedwarn ("ISO C++ forbids using pointer to a function in subtraction");
3490 if (TREE_CODE (target_type) == METHOD_TYPE)
3491 pedwarn ("ISO C++ forbids using pointer to a method in subtraction");
3494 /* First do the subtraction as integers;
3495 then drop through to build the divide operator. */
3497 op0 = cp_build_binary_op (MINUS_EXPR,
3498 cp_convert (restype, op0),
3499 cp_convert (restype, op1));
3501 /* This generates an error if op1 is a pointer to an incomplete type. */
3502 if (!COMPLETE_TYPE_P (TREE_TYPE (TREE_TYPE (op1))))
3503 error ("invalid use of a pointer to an incomplete type in pointer arithmetic");
3505 op1 = (TYPE_PTROB_P (ptrtype)
3506 ? size_in_bytes (target_type)
3507 : integer_one_node);
3509 /* Do the division. */
3511 result = build (EXACT_DIV_EXPR, restype, op0, cp_convert (restype, op1));
3512 return fold (result);
3515 /* Construct and perhaps optimize a tree representation
3516 for a unary operation. CODE, a tree_code, specifies the operation
3517 and XARG is the operand. */
3520 build_x_unary_op (enum tree_code code, tree xarg)
3522 tree orig_expr = xarg;
3526 if (processing_template_decl)
3528 if (type_dependent_expression_p (xarg))
3529 return build_min_nt (code, xarg, NULL_TREE);
3530 xarg = build_non_dependent_expr (xarg);
3535 /* [expr.unary.op] says:
3537 The address of an object of incomplete type can be taken.
3539 (And is just the ordinary address operator, not an overloaded
3540 "operator &".) However, if the type is a template
3541 specialization, we must complete the type at this point so that
3542 an overloaded "operator &" will be available if required. */
3543 if (code == ADDR_EXPR
3544 && TREE_CODE (xarg) != TEMPLATE_ID_EXPR
3545 && ((CLASS_TYPE_P (TREE_TYPE (xarg))
3546 && !COMPLETE_TYPE_P (complete_type (TREE_TYPE (xarg))))
3547 || (TREE_CODE (xarg) == OFFSET_REF)))
3548 /* Don't look for a function. */;
3550 exp = build_new_op (code, LOOKUP_NORMAL, xarg, NULL_TREE, NULL_TREE,
3551 /*overloaded_p=*/NULL);
3552 if (!exp && code == ADDR_EXPR)
3554 /* A pointer to member-function can be formed only by saying
3556 if (!flag_ms_extensions && TREE_CODE (TREE_TYPE (xarg)) == METHOD_TYPE
3557 && (TREE_CODE (xarg) != OFFSET_REF || !PTRMEM_OK_P (xarg)))
3559 if (TREE_CODE (xarg) != OFFSET_REF)
3561 error ("invalid use of '%E' to form a pointer-to-member-function. Use a qualified-id.",
3563 return error_mark_node;
3567 error ("parenthesis around '%E' cannot be used to form a pointer-to-member-function",
3569 PTRMEM_OK_P (xarg) = 1;
3573 if (TREE_CODE (xarg) == OFFSET_REF)
3575 ptrmem = PTRMEM_OK_P (xarg);
3577 if (!ptrmem && !flag_ms_extensions
3578 && TREE_CODE (TREE_TYPE (TREE_OPERAND (xarg, 1))) == METHOD_TYPE)
3580 /* A single non-static member, make sure we don't allow a
3581 pointer-to-member. */
3582 xarg = build (OFFSET_REF, TREE_TYPE (xarg),
3583 TREE_OPERAND (xarg, 0),
3584 ovl_cons (TREE_OPERAND (xarg, 1), NULL_TREE));
3585 PTRMEM_OK_P (xarg) = ptrmem;
3588 else if (TREE_CODE (xarg) == TARGET_EXPR)
3589 warning ("taking address of temporary");
3590 exp = build_unary_op (ADDR_EXPR, xarg, 0);
3591 if (TREE_CODE (exp) == ADDR_EXPR)
3592 PTRMEM_OK_P (exp) = ptrmem;
3595 if (processing_template_decl && exp != error_mark_node)
3596 return build_min_non_dep (code, exp, orig_expr,
3597 /*For {PRE,POST}{INC,DEC}REMENT_EXPR*/NULL_TREE);
3601 /* Like c_common_truthvalue_conversion, but handle pointer-to-member
3602 constants, where a null value is represented by an INTEGER_CST of
3606 cp_truthvalue_conversion (tree expr)
3608 tree type = TREE_TYPE (expr);
3609 if (TYPE_PTRMEM_P (type))
3610 return build_binary_op (NE_EXPR, expr, integer_zero_node, 1);
3612 return c_common_truthvalue_conversion (expr);
3615 /* Just like cp_truthvalue_conversion, but we want a CLEANUP_POINT_EXPR. */
3618 condition_conversion (tree expr)
3621 if (processing_template_decl)
3623 t = perform_implicit_conversion (boolean_type_node, expr);
3624 t = fold (build1 (CLEANUP_POINT_EXPR, boolean_type_node, t));
3628 /* Return an ADDR_EXPR giving the address of T. This function
3629 attempts no optimizations or simplifications; it is a low-level
3633 build_address (tree t)
3637 if (error_operand_p (t) || !cxx_mark_addressable (t))
3638 return error_mark_node;
3640 addr = build1 (ADDR_EXPR, build_pointer_type (TREE_TYPE (t)), t);
3645 /* Return a NOP_EXPR converting EXPR to TYPE. */
3648 build_nop (tree type, tree expr)
3650 if (type == error_mark_node || error_operand_p (expr))
3652 return build1 (NOP_EXPR, type, expr);
3655 /* C++: Must handle pointers to members.
3657 Perhaps type instantiation should be extended to handle conversion
3658 from aggregates to types we don't yet know we want? (Or are those
3659 cases typically errors which should be reported?)
3661 NOCONVERT nonzero suppresses the default promotions
3662 (such as from short to int). */
3665 build_unary_op (enum tree_code code, tree xarg, int noconvert)
3667 /* No default_conversion here. It causes trouble for ADDR_EXPR. */
3670 const char *errstring = NULL;
3673 if (arg == error_mark_node)
3674 return error_mark_node;
3679 /* This is used for unary plus, because a CONVERT_EXPR
3680 is enough to prevent anybody from looking inside for
3681 associativity, but won't generate any code. */
3682 if (!(arg = build_expr_type_conversion
3683 (WANT_ARITH | WANT_ENUM | WANT_POINTER, arg, true)))
3684 errstring = "wrong type argument to unary plus";
3688 arg = default_conversion (arg);
3689 arg = build1 (NON_LVALUE_EXPR, TREE_TYPE (arg), arg);
3694 if (!(arg = build_expr_type_conversion (WANT_ARITH | WANT_ENUM, arg, true)))
3695 errstring = "wrong type argument to unary minus";
3696 else if (!noconvert && CP_INTEGRAL_TYPE_P (TREE_TYPE (arg)))
3697 arg = perform_integral_promotions (arg);
3701 if (TREE_CODE (TREE_TYPE (arg)) == COMPLEX_TYPE)
3705 arg = default_conversion (arg);
3707 else if (!(arg = build_expr_type_conversion (WANT_INT | WANT_ENUM,
3709 errstring = "wrong type argument to bit-complement";
3710 else if (!noconvert)
3711 arg = perform_integral_promotions (arg);
3715 if (!(arg = build_expr_type_conversion (WANT_ARITH | WANT_ENUM, arg, true)))
3716 errstring = "wrong type argument to abs";
3717 else if (!noconvert)
3718 arg = default_conversion (arg);
3722 /* Conjugating a real value is a no-op, but allow it anyway. */
3723 if (!(arg = build_expr_type_conversion (WANT_ARITH | WANT_ENUM, arg, true)))
3724 errstring = "wrong type argument to conjugation";
3725 else if (!noconvert)
3726 arg = default_conversion (arg);
3729 case TRUTH_NOT_EXPR:
3730 arg = perform_implicit_conversion (boolean_type_node, arg);
3731 val = invert_truthvalue (arg);
3732 if (arg != error_mark_node)
3734 errstring = "in argument to unary !";
3741 if (TREE_CODE (arg) == COMPLEX_CST)
3742 return TREE_REALPART (arg);
3743 else if (TREE_CODE (TREE_TYPE (arg)) == COMPLEX_TYPE)
3744 return fold (build1 (REALPART_EXPR, TREE_TYPE (TREE_TYPE (arg)), arg));
3749 if (TREE_CODE (arg) == COMPLEX_CST)
3750 return TREE_IMAGPART (arg);
3751 else if (TREE_CODE (TREE_TYPE (arg)) == COMPLEX_TYPE)
3752 return fold (build1 (IMAGPART_EXPR, TREE_TYPE (TREE_TYPE (arg)), arg));
3754 return cp_convert (TREE_TYPE (arg), integer_zero_node);
3756 case PREINCREMENT_EXPR:
3757 case POSTINCREMENT_EXPR:
3758 case PREDECREMENT_EXPR:
3759 case POSTDECREMENT_EXPR:
3760 /* Handle complex lvalues (when permitted)
3761 by reduction to simpler cases. */
3763 val = unary_complex_lvalue (code, arg);
3767 /* Increment or decrement the real part of the value,
3768 and don't change the imaginary part. */
3769 if (TREE_CODE (TREE_TYPE (arg)) == COMPLEX_TYPE)
3773 arg = stabilize_reference (arg);
3774 real = build_unary_op (REALPART_EXPR, arg, 1);
3775 imag = build_unary_op (IMAGPART_EXPR, arg, 1);
3776 return build (COMPLEX_EXPR, TREE_TYPE (arg),
3777 build_unary_op (code, real, 1), imag);
3780 /* Report invalid types. */
3782 if (!(arg = build_expr_type_conversion (WANT_ARITH | WANT_POINTER,
3785 if (code == PREINCREMENT_EXPR)
3786 errstring ="no pre-increment operator for type";
3787 else if (code == POSTINCREMENT_EXPR)
3788 errstring ="no post-increment operator for type";
3789 else if (code == PREDECREMENT_EXPR)
3790 errstring ="no pre-decrement operator for type";
3792 errstring ="no post-decrement operator for type";
3796 /* Report something read-only. */
3798 if (CP_TYPE_CONST_P (TREE_TYPE (arg))
3799 || TREE_READONLY (arg))
3800 readonly_error (arg, ((code == PREINCREMENT_EXPR
3801 || code == POSTINCREMENT_EXPR)
3802 ? "increment" : "decrement"),
3807 tree result_type = TREE_TYPE (arg);
3809 arg = get_unwidened (arg, 0);
3810 argtype = TREE_TYPE (arg);
3812 /* ARM $5.2.5 last annotation says this should be forbidden. */
3813 if (TREE_CODE (argtype) == ENUMERAL_TYPE)
3814 pedwarn ("ISO C++ forbids %sing an enum",
3815 (code == PREINCREMENT_EXPR || code == POSTINCREMENT_EXPR)
3816 ? "increment" : "decrement");
3818 /* Compute the increment. */
3820 if (TREE_CODE (argtype) == POINTER_TYPE)
3822 tree type = complete_type (TREE_TYPE (argtype));
3824 if (!COMPLETE_OR_VOID_TYPE_P (type))
3825 error ("cannot %s a pointer to incomplete type `%T'",
3826 ((code == PREINCREMENT_EXPR
3827 || code == POSTINCREMENT_EXPR)
3828 ? "increment" : "decrement"), TREE_TYPE (argtype));
3829 else if ((pedantic || warn_pointer_arith)
3830 && !TYPE_PTROB_P (argtype))
3831 pedwarn ("ISO C++ forbids %sing a pointer of type `%T'",
3832 ((code == PREINCREMENT_EXPR
3833 || code == POSTINCREMENT_EXPR)
3834 ? "increment" : "decrement"), argtype);
3835 inc = cxx_sizeof_nowarn (TREE_TYPE (argtype));
3838 inc = integer_one_node;
3840 inc = cp_convert (argtype, inc);
3842 /* Handle incrementing a cast-expression. */
3844 switch (TREE_CODE (arg))
3849 case FIX_TRUNC_EXPR:
3850 case FIX_FLOOR_EXPR:
3851 case FIX_ROUND_EXPR:
3854 tree incremented, modify, value, compound;
3855 if (! lvalue_p (arg) && pedantic)
3856 pedwarn ("cast to non-reference type used as lvalue");
3857 arg = stabilize_reference (arg);
3858 if (code == PREINCREMENT_EXPR || code == PREDECREMENT_EXPR)
3861 value = save_expr (arg);
3862 incremented = build (((code == PREINCREMENT_EXPR
3863 || code == POSTINCREMENT_EXPR)
3864 ? PLUS_EXPR : MINUS_EXPR),
3865 argtype, value, inc);
3867 modify = build_modify_expr (arg, NOP_EXPR, incremented);
3868 compound = build (COMPOUND_EXPR, TREE_TYPE (arg), modify, value);
3870 /* Eliminate warning about unused result of + or -. */
3871 TREE_NO_WARNING (compound) = 1;
3879 /* Complain about anything else that is not a true lvalue. */
3880 if (!lvalue_or_else (arg, ((code == PREINCREMENT_EXPR
3881 || code == POSTINCREMENT_EXPR)
3882 ? "increment" : "decrement")))
3883 return error_mark_node;
3885 /* Forbid using -- on `bool'. */
3886 if (TREE_TYPE (arg) == boolean_type_node)
3888 if (code == POSTDECREMENT_EXPR || code == PREDECREMENT_EXPR)
3890 error ("invalid use of `--' on bool variable `%D'", arg);
3891 return error_mark_node;
3893 val = boolean_increment (code, arg);
3896 val = build (code, TREE_TYPE (arg), arg, inc);
3898 TREE_SIDE_EFFECTS (val) = 1;
3899 return cp_convert (result_type, val);
3903 /* Note that this operation never does default_conversion
3904 regardless of NOCONVERT. */
3906 argtype = lvalue_type (arg);
3908 if (TREE_CODE (arg) == OFFSET_REF)
3911 if (TREE_CODE (argtype) == REFERENCE_TYPE)
3913 tree type = build_pointer_type (TREE_TYPE (argtype));
3914 arg = build1 (CONVERT_EXPR, type, arg);
3917 else if (pedantic && DECL_MAIN_P (arg))
3919 pedwarn ("ISO C++ forbids taking address of function `::main'");
3921 /* Let &* cancel out to simplify resulting code. */
3922 if (TREE_CODE (arg) == INDIRECT_REF)
3924 /* We don't need to have `current_class_ptr' wrapped in a
3925 NON_LVALUE_EXPR node. */
3926 if (arg == current_class_ref)
3927 return current_class_ptr;
3929 arg = TREE_OPERAND (arg, 0);
3930 if (TREE_CODE (TREE_TYPE (arg)) == REFERENCE_TYPE)
3932 tree type = build_pointer_type (TREE_TYPE (TREE_TYPE (arg)));
3933 arg = build1 (CONVERT_EXPR, type, arg);
3935 else if (lvalue_p (arg))
3936 /* Don't let this be an lvalue. */
3937 return non_lvalue (arg);
3941 /* For &x[y], return x+y. But, in a template, ARG may be an
3942 ARRAY_REF representing a non-dependent expression. In that
3943 case, there may be an overloaded "operator []" that will be
3944 chosen at instantiation time; we must not try to optimize
3946 if (TREE_CODE (arg) == ARRAY_REF && !processing_template_decl)
3948 if (!cxx_mark_addressable (TREE_OPERAND (arg, 0)))
3949 return error_mark_node;
3950 return cp_build_binary_op (PLUS_EXPR, TREE_OPERAND (arg, 0),
3951 TREE_OPERAND (arg, 1));
3954 /* Uninstantiated types are all functions. Taking the
3955 address of a function is a no-op, so just return the
3958 if (TREE_CODE (arg) == IDENTIFIER_NODE
3959 && IDENTIFIER_OPNAME_P (arg))
3962 /* We don't know the type yet, so just work around the problem.
3963 We know that this will resolve to an lvalue. */
3964 return build1 (ADDR_EXPR, unknown_type_node, arg);
3967 if (TREE_CODE (arg) == COMPONENT_REF && type_unknown_p (arg)
3968 && !really_overloaded_fn (TREE_OPERAND (arg, 1)))
3970 /* They're trying to take the address of a unique non-static
3971 member function. This is ill-formed (except in MS-land),
3972 but let's try to DTRT.
3973 Note: We only handle unique functions here because we don't
3974 want to complain if there's a static overload; non-unique
3975 cases will be handled by instantiate_type. But we need to
3976 handle this case here to allow casts on the resulting PMF.
3977 We could defer this in non-MS mode, but it's easier to give
3978 a useful error here. */
3980 /* Inside constant member functions, the `this' pointer
3981 contains an extra const qualifier. TYPE_MAIN_VARIANT
3982 is used here to remove this const from the diagnostics
3983 and the created OFFSET_REF. */
3984 tree base = TYPE_MAIN_VARIANT (TREE_TYPE (TREE_OPERAND (arg, 0)));
3985 tree name = DECL_NAME (get_first_fn (TREE_OPERAND (arg, 1)));
3987 if (! flag_ms_extensions)
3989 if (current_class_type
3990 && TREE_OPERAND (arg, 0) == current_class_ref)
3991 /* An expression like &memfn. */
3992 pedwarn ("ISO C++ forbids taking the address of an unqualified"
3993 " or parenthesized non-static member function to form"
3994 " a pointer to member function. Say `&%T::%D'",
3997 pedwarn ("ISO C++ forbids taking the address of a bound member"
3998 " function to form a pointer to member function."
4002 arg = build_offset_ref (base, name, /*address_p=*/true);
4006 if (type_unknown_p (arg))
4007 return build1 (ADDR_EXPR, unknown_type_node, arg);
4009 /* Handle complex lvalues (when permitted)
4010 by reduction to simpler cases. */
4011 val = unary_complex_lvalue (code, arg);
4015 switch (TREE_CODE (arg))
4020 case FIX_TRUNC_EXPR:
4021 case FIX_FLOOR_EXPR:
4022 case FIX_ROUND_EXPR:
4024 if (! lvalue_p (arg) && pedantic)
4025 pedwarn ("ISO C++ forbids taking the address of a cast to a non-lvalue expression");
4029 arg = OVL_CURRENT (arg);
4036 /* Allow the address of a constructor if all the elements
4038 if (TREE_CODE (arg) == CONSTRUCTOR && TREE_HAS_CONSTRUCTOR (arg)
4039 && TREE_CONSTANT (arg))
4041 /* Anything not already handled and not a true memory reference
4043 else if (TREE_CODE (argtype) != FUNCTION_TYPE
4044 && TREE_CODE (argtype) != METHOD_TYPE
4045 && !lvalue_or_else (arg, "unary `&'"))
4046 return error_mark_node;
4048 if (argtype != error_mark_node)
4049 argtype = build_pointer_type (argtype);
4054 if (TREE_CODE (arg) != COMPONENT_REF
4055 /* Inside a template, we are processing a non-dependent
4056 expression so we can just form an ADDR_EXPR with the
4058 || processing_template_decl)
4059 addr = build_address (arg);
4060 else if (TREE_CODE (TREE_OPERAND (arg, 1)) == BASELINK)
4062 tree fn = BASELINK_FUNCTIONS (TREE_OPERAND (arg, 1));
4064 /* We can only get here with a single static member
4066 my_friendly_assert (TREE_CODE (fn) == FUNCTION_DECL
4067 && DECL_STATIC_FUNCTION_P (fn),
4070 addr = build_address (fn);
4071 if (TREE_SIDE_EFFECTS (TREE_OPERAND (arg, 0)))
4072 /* Do not lose object's side effects. */
4073 addr = build (COMPOUND_EXPR, TREE_TYPE (addr),
4074 TREE_OPERAND (arg, 0), addr);
4076 else if (DECL_C_BIT_FIELD (TREE_OPERAND (arg, 1)))
4078 error ("attempt to take address of bit-field structure member `%D'",
4079 TREE_OPERAND (arg, 1));
4080 return error_mark_node;
4084 /* Unfortunately we cannot just build an address
4085 expression here, because we would not handle
4086 address-constant-expressions or offsetof correctly. */
4087 tree field = TREE_OPERAND (arg, 1);
4088 tree rval = build_unary_op (ADDR_EXPR, TREE_OPERAND (arg, 0), 0);
4089 tree binfo = lookup_base (TREE_TYPE (TREE_TYPE (rval)),
4090 decl_type_context (field),
4093 rval = build_base_path (PLUS_EXPR, rval, binfo, 1);
4094 rval = build_nop (argtype, rval);
4095 addr = fold (build (PLUS_EXPR, argtype, rval,
4096 cp_convert (argtype, byte_position (field))));
4099 if (TREE_CODE (argtype) == POINTER_TYPE
4100 && TREE_CODE (TREE_TYPE (argtype)) == METHOD_TYPE)
4102 build_ptrmemfunc_type (argtype);
4103 addr = build_ptrmemfunc (argtype, addr, 0);
4116 argtype = TREE_TYPE (arg);
4117 return fold (build1 (code, argtype, arg));
4120 error ("%s", errstring);
4121 return error_mark_node;
4124 /* Apply unary lvalue-demanding operator CODE to the expression ARG
4125 for certain kinds of expressions which are not really lvalues
4126 but which we can accept as lvalues.
4128 If ARG is not a kind of expression we can handle, return zero. */
4131 unary_complex_lvalue (enum tree_code code, tree arg)
4133 /* Handle (a, b) used as an "lvalue". */
4134 if (TREE_CODE (arg) == COMPOUND_EXPR)
4136 tree real_result = build_unary_op (code, TREE_OPERAND (arg, 1), 0);
4137 return build (COMPOUND_EXPR, TREE_TYPE (real_result),
4138 TREE_OPERAND (arg, 0), real_result);
4141 /* Handle (a ? b : c) used as an "lvalue". */
4142 if (TREE_CODE (arg) == COND_EXPR
4143 || TREE_CODE (arg) == MIN_EXPR || TREE_CODE (arg) == MAX_EXPR)
4144 return rationalize_conditional_expr (code, arg);
4146 /* Handle (a = b), (++a), and (--a) used as an "lvalue". */
4147 if (TREE_CODE (arg) == MODIFY_EXPR
4148 || TREE_CODE (arg) == PREINCREMENT_EXPR
4149 || TREE_CODE (arg) == PREDECREMENT_EXPR)
4151 tree lvalue = TREE_OPERAND (arg, 0);
4152 if (TREE_SIDE_EFFECTS (lvalue))
4154 lvalue = stabilize_reference (lvalue);
4155 arg = build (TREE_CODE (arg), TREE_TYPE (arg),
4156 lvalue, TREE_OPERAND (arg, 1));
4158 return unary_complex_lvalue
4159 (code, build (COMPOUND_EXPR, TREE_TYPE (lvalue), arg, lvalue));
4162 if (code != ADDR_EXPR)
4165 /* Handle (a = b) used as an "lvalue" for `&'. */
4166 if (TREE_CODE (arg) == MODIFY_EXPR
4167 || TREE_CODE (arg) == INIT_EXPR)
4169 tree real_result = build_unary_op (code, TREE_OPERAND (arg, 0), 0);
4170 arg = build (COMPOUND_EXPR, TREE_TYPE (real_result), arg, real_result);
4171 TREE_NO_WARNING (arg) = 1;
4175 if (TREE_CODE (TREE_TYPE (arg)) == FUNCTION_TYPE
4176 || TREE_CODE (TREE_TYPE (arg)) == METHOD_TYPE
4177 || TREE_CODE (arg) == OFFSET_REF)
4181 my_friendly_assert (TREE_CODE (arg) != SCOPE_REF, 313);
4183 if (TREE_CODE (arg) != OFFSET_REF)
4186 t = TREE_OPERAND (arg, 1);
4188 /* Check all this code for right semantics. */
4189 if (TREE_CODE (t) == FUNCTION_DECL)
4191 if (DECL_DESTRUCTOR_P (t))
4192 error ("taking address of destructor");
4193 return build_unary_op (ADDR_EXPR, t, 0);
4195 if (TREE_CODE (t) == VAR_DECL)
4196 return build_unary_op (ADDR_EXPR, t, 0);
4201 if (TREE_OPERAND (arg, 0)
4202 && ! is_dummy_object (TREE_OPERAND (arg, 0))
4203 && TREE_CODE (t) != FIELD_DECL)
4205 error ("taking address of bound pointer-to-member expression");
4206 return error_mark_node;
4208 if (!PTRMEM_OK_P (arg))
4209 return build_unary_op (code, arg, 0);
4211 if (TREE_CODE (TREE_TYPE (t)) == REFERENCE_TYPE)
4213 error ("cannot create pointer to reference member `%D'", t);
4214 return error_mark_node;
4217 type = build_ptrmem_type (context_for_name_lookup (t),
4219 t = make_ptrmem_cst (type, TREE_OPERAND (arg, 1));
4225 /* We permit compiler to make function calls returning
4226 objects of aggregate type look like lvalues. */
4230 if (TREE_CODE (targ) == SAVE_EXPR)
4231 targ = TREE_OPERAND (targ, 0);
4233 if (TREE_CODE (targ) == CALL_EXPR && IS_AGGR_TYPE (TREE_TYPE (targ)))
4235 if (TREE_CODE (arg) == SAVE_EXPR)
4238 targ = build_cplus_new (TREE_TYPE (arg), arg);
4239 return build1 (ADDR_EXPR, build_pointer_type (TREE_TYPE (arg)), targ);
4242 if (TREE_CODE (arg) == SAVE_EXPR && TREE_CODE (targ) == INDIRECT_REF)
4243 return build (SAVE_EXPR, build_pointer_type (TREE_TYPE (arg)),
4244 TREE_OPERAND (targ, 0), current_function_decl, NULL);
4247 /* Don't let anything else be handled specially. */
4251 /* Mark EXP saying that we need to be able to take the
4252 address of it; it should not be allocated in a register.
4253 Value is true if successful.
4255 C++: we do not allow `current_class_ptr' to be addressable. */
4258 cxx_mark_addressable (tree exp)
4263 switch (TREE_CODE (x))
4270 x = TREE_OPERAND (x, 0);
4274 if (x == current_class_ptr)
4276 error ("cannot take the address of `this', which is an rvalue expression");
4277 TREE_ADDRESSABLE (x) = 1; /* so compiler doesn't die later. */
4283 /* Caller should not be trying to mark initialized
4284 constant fields addressable. */
4285 my_friendly_assert (DECL_LANG_SPECIFIC (x) == 0
4286 || DECL_IN_AGGR_P (x) == 0
4288 || DECL_EXTERNAL (x), 314);
4293 if (DECL_REGISTER (x) && !TREE_ADDRESSABLE (x)
4294 && !DECL_ARTIFICIAL (x) && extra_warnings)
4295 warning ("address requested for `%D', which is declared `register'",
4297 TREE_ADDRESSABLE (x) = 1;
4298 put_var_into_stack (x, /*rescan=*/true);
4302 TREE_ADDRESSABLE (x) = 1;
4306 TREE_ADDRESSABLE (x) = 1;
4310 TREE_ADDRESSABLE (x) = 1;
4311 cxx_mark_addressable (TREE_OPERAND (x, 0));
4319 /* Build and return a conditional expression IFEXP ? OP1 : OP2. */
4322 build_x_conditional_expr (tree ifexp, tree op1, tree op2)
4324 tree orig_ifexp = ifexp;
4325 tree orig_op1 = op1;
4326 tree orig_op2 = op2;
4329 if (processing_template_decl)
4331 /* The standard says that the expression is type-dependent if
4332 IFEXP is type-dependent, even though the eventual type of the
4333 expression doesn't dependent on IFEXP. */
4334 if (type_dependent_expression_p (ifexp)
4335 /* As a GNU extension, the middle operand may be omitted. */
4336 || (op1 && type_dependent_expression_p (op1))
4337 || type_dependent_expression_p (op2))
4338 return build_min_nt (COND_EXPR, ifexp, op1, op2);
4339 ifexp = build_non_dependent_expr (ifexp);
4341 op1 = build_non_dependent_expr (op1);
4342 op2 = build_non_dependent_expr (op2);
4345 expr = build_conditional_expr (ifexp, op1, op2);
4346 if (processing_template_decl && expr != error_mark_node)
4347 return build_min_non_dep (COND_EXPR, expr,
4348 orig_ifexp, orig_op1, orig_op2);
4352 /* Given a list of expressions, return a compound expression
4353 that performs them all and returns the value of the last of them. */
4355 tree build_x_compound_expr_from_list (tree list, const char *msg)
4357 tree expr = TREE_VALUE (list);
4359 if (TREE_CHAIN (list))
4362 pedwarn ("%s expression list treated as compound expression", msg);
4364 for (list = TREE_CHAIN (list); list; list = TREE_CHAIN (list))
4365 expr = build_x_compound_expr (expr, TREE_VALUE (list));
4371 /* Handle overloading of the ',' operator when needed. */
4374 build_x_compound_expr (tree op1, tree op2)
4377 tree orig_op1 = op1;
4378 tree orig_op2 = op2;
4380 if (processing_template_decl)
4382 if (type_dependent_expression_p (op1)
4383 || type_dependent_expression_p (op2))
4384 return build_min_nt (COMPOUND_EXPR, op1, op2);
4385 op1 = build_non_dependent_expr (op1);
4386 op2 = build_non_dependent_expr (op2);
4389 result = build_new_op (COMPOUND_EXPR, LOOKUP_NORMAL, op1, op2, NULL_TREE,
4390 /*overloaded_p=*/NULL);
4392 result = build_compound_expr (op1, op2);
4394 if (processing_template_decl && result != error_mark_node)
4395 return build_min_non_dep (COMPOUND_EXPR, result, orig_op1, orig_op2);
4400 /* Build a compound expression. */
4403 build_compound_expr (tree lhs, tree rhs)
4405 lhs = decl_constant_value (lhs);
4406 lhs = convert_to_void (lhs, "left-hand operand of comma");
4408 if (lhs == error_mark_node || rhs == error_mark_node)
4409 return error_mark_node;
4411 if (TREE_CODE (rhs) == TARGET_EXPR)
4413 /* If the rhs is a TARGET_EXPR, then build the compound
4414 expression inside the target_expr's initializer. This
4415 helps the compiler to eliminate unnecessary temporaries. */
4416 tree init = TREE_OPERAND (rhs, 1);
4418 init = build (COMPOUND_EXPR, TREE_TYPE (init), lhs, init);
4419 TREE_OPERAND (rhs, 1) = init;
4424 return build (COMPOUND_EXPR, TREE_TYPE (rhs), lhs, rhs);
4427 /* Issue an error message if casting from SRC_TYPE to DEST_TYPE casts
4428 away constness. DESCRIPTION explains what operation is taking
4432 check_for_casting_away_constness (tree src_type, tree dest_type,
4433 const char *description)
4435 if (casts_away_constness (src_type, dest_type))
4436 error ("%s from type `%T' to type `%T' casts away constness",
4437 description, src_type, dest_type);
4440 /* Return an expression representing static_cast<TYPE>(EXPR). */
4443 build_static_cast (tree type, tree expr)
4448 if (type == error_mark_node || expr == error_mark_node)
4449 return error_mark_node;
4451 if (processing_template_decl)
4453 expr = build_min (STATIC_CAST_EXPR, type, expr);
4454 /* We don't know if it will or will not have side effects. */
4455 TREE_SIDE_EFFECTS (expr) = 1;
4459 /* build_c_cast puts on a NOP_EXPR to make the result not an lvalue.
4460 Strip such NOP_EXPRs if VALUE is being used in non-lvalue context. */
4461 if (TREE_CODE (type) != REFERENCE_TYPE
4462 && TREE_CODE (expr) == NOP_EXPR
4463 && TREE_TYPE (expr) == TREE_TYPE (TREE_OPERAND (expr, 0)))
4464 expr = TREE_OPERAND (expr, 0);
4466 intype = TREE_TYPE (expr);
4468 /* [expr.static.cast]
4470 An lvalue of type "cv1 B", where B is a class type, can be cast
4471 to type "reference to cv2 D", where D is a class derived (clause
4472 _class.derived_) from B, if a valid standard conversion from
4473 "pointer to D" to "pointer to B" exists (_conv.ptr_), cv2 is the
4474 same cv-qualification as, or greater cv-qualification than, cv1,
4475 and B is not a virtual base class of D. */
4476 /* We check this case before checking the validity of "TYPE t =
4477 EXPR;" below because for this case:
4480 struct D : public B { D(const B&); };
4482 void f() { static_cast<const D&>(b); }
4484 we want to avoid constructing a new D. The standard is not
4485 completely clear about this issue, but our interpretation is
4486 consistent with other compilers. */
4487 if (TREE_CODE (type) == REFERENCE_TYPE
4488 && CLASS_TYPE_P (TREE_TYPE (type))
4489 && CLASS_TYPE_P (intype)
4490 && real_lvalue_p (expr)
4491 && DERIVED_FROM_P (intype, TREE_TYPE (type))
4492 && can_convert (build_pointer_type (TYPE_MAIN_VARIANT (intype)),
4493 build_pointer_type (TYPE_MAIN_VARIANT
4494 (TREE_TYPE (type))))
4495 && at_least_as_qualified_p (TREE_TYPE (type), intype))
4497 /* There is a standard conversion from "D*" to "B*" even if "B"
4498 is ambiguous or inaccessible. Therefore, we ask lookup_base
4499 to check these conditions. */
4500 tree base = lookup_base (TREE_TYPE (type), intype, ba_check, NULL);
4502 /* Convert from "B*" to "D*". This function will check that "B"
4503 is not a virtual base of "D". */
4504 expr = build_base_path (MINUS_EXPR, build_address (expr),
4505 base, /*nonnull=*/false);
4506 /* Convert the pointer to a reference -- but then remember that
4507 there are no expressions with reference type in C++. */
4508 return convert_from_reference (build_nop (type, expr));
4511 /* [expr.static.cast]
4513 An expression e can be explicitly converted to a type T using a
4514 static_cast of the form static_cast<T>(e) if the declaration T
4515 t(e);" is well-formed, for some invented temporary variable
4517 result = perform_direct_initialization_if_possible (type, expr);
4520 result = convert_from_reference (result);
4521 /* [expr.static.cast]
4523 If T is a reference type, the result is an lvalue; otherwise,
4524 the result is an rvalue. */
4525 if (TREE_CODE (type) != REFERENCE_TYPE
4526 && real_lvalue_p (result))
4527 result = build1 (NON_LVALUE_EXPR, TREE_TYPE (result), result);
4531 /* [expr.static.cast]
4533 Any expression can be explicitly converted to type cv void. */
4534 if (TREE_CODE (type) == VOID_TYPE)
4535 return convert_to_void (expr, /*implicit=*/NULL);
4537 /* [expr.static.cast]
4539 The inverse of any standard conversion sequence (clause _conv_),
4540 other than the lvalue-to-rvalue (_conv.lval_), array-to-pointer
4541 (_conv.array_), function-to-pointer (_conv.func_), and boolean
4542 (_conv.bool_) conversions, can be performed explicitly using
4543 static_cast subject to the restriction that the explicit
4544 conversion does not cast away constness (_expr.const.cast_), and
4545 the following additional rules for specific cases: */
4546 /* For reference, the conversions not excluded are: integral
4547 promotions, floating point promotion, integral conversions,
4548 floating point conversions, floating-integral conversions,
4549 pointer conversions, and pointer to member conversions. */
4550 if ((ARITHMETIC_TYPE_P (type) && ARITHMETIC_TYPE_P (intype))
4553 A value of integral _or enumeration_ type can be explicitly
4554 converted to an enumeration type. */
4555 || (INTEGRAL_OR_ENUMERATION_TYPE_P (type)
4556 && INTEGRAL_OR_ENUMERATION_TYPE_P (intype)))
4557 /* Really, build_c_cast should defer to this function rather
4558 than the other way around. */
4559 return build_c_cast (type, expr);
4561 if (TYPE_PTR_P (type) && TYPE_PTR_P (intype)
4562 && CLASS_TYPE_P (TREE_TYPE (type))
4563 && CLASS_TYPE_P (TREE_TYPE (intype))
4564 && can_convert (build_pointer_type (TYPE_MAIN_VARIANT
4565 (TREE_TYPE (intype))),
4566 build_pointer_type (TYPE_MAIN_VARIANT
4567 (TREE_TYPE (type)))))
4571 check_for_casting_away_constness (intype, type, "static_cast");
4572 base = lookup_base (TREE_TYPE (type), TREE_TYPE (intype), ba_check,
4574 return build_base_path (MINUS_EXPR, expr, base, /*nonnull=*/false);
4577 if ((TYPE_PTRMEM_P (type) && TYPE_PTRMEM_P (intype))
4578 || (TYPE_PTRMEMFUNC_P (type) && TYPE_PTRMEMFUNC_P (intype)))
4585 c1 = TYPE_PTRMEM_CLASS_TYPE (intype);
4586 c2 = TYPE_PTRMEM_CLASS_TYPE (type);
4588 if (TYPE_PTRMEM_P (type))
4590 t1 = (build_ptrmem_type
4592 TYPE_MAIN_VARIANT (TYPE_PTRMEM_POINTED_TO_TYPE (intype))));
4593 t2 = (build_ptrmem_type
4595 TYPE_MAIN_VARIANT (TYPE_PTRMEM_POINTED_TO_TYPE (type))));
4602 if (can_convert (t1, t2))
4604 check_for_casting_away_constness (intype, type, "static_cast");
4605 if (TYPE_PTRMEM_P (type))
4609 if (TREE_CODE (expr) == PTRMEM_CST)
4610 expr = cplus_expand_constant (expr);
4611 delta = get_delta_difference (c1, c2, /*force=*/1);
4612 if (!integer_zerop (delta))
4613 expr = cp_build_binary_op (PLUS_EXPR,
4614 build_nop (ptrdiff_type_node, expr),
4616 return build_nop (type, expr);
4619 return build_ptrmemfunc (TYPE_PTRMEMFUNC_FN_TYPE (type), expr,
4624 /* [expr.static.cast]
4626 An rvalue of type "pointer to cv void" can be explicitly
4627 converted to a pointer to object type. A value of type pointer
4628 to object converted to "pointer to cv void" and back to the
4629 original pointer type will have its original value. */
4630 if (TREE_CODE (intype) == POINTER_TYPE
4631 && VOID_TYPE_P (TREE_TYPE (intype))
4632 && TYPE_PTROB_P (type))
4634 check_for_casting_away_constness (intype, type, "static_cast");
4635 return build_nop (type, expr);
4638 error ("invalid static_cast from type `%T' to type `%T'", intype, type);
4639 return error_mark_node;
4643 build_reinterpret_cast (tree type, tree expr)
4647 if (type == error_mark_node || expr == error_mark_node)
4648 return error_mark_node;
4650 if (processing_template_decl)
4652 tree t = build_min (REINTERPRET_CAST_EXPR, type, expr);
4654 if (!TREE_SIDE_EFFECTS (t)
4655 && type_dependent_expression_p (expr))
4656 /* There might turn out to be side effects inside expr. */
4657 TREE_SIDE_EFFECTS (t) = 1;
4661 if (TREE_CODE (type) != REFERENCE_TYPE)
4663 expr = decay_conversion (expr);
4665 /* build_c_cast puts on a NOP_EXPR to make the result not an lvalue.
4666 Strip such NOP_EXPRs if VALUE is being used in non-lvalue context. */
4667 if (TREE_CODE (expr) == NOP_EXPR
4668 && TREE_TYPE (expr) == TREE_TYPE (TREE_OPERAND (expr, 0)))
4669 expr = TREE_OPERAND (expr, 0);
4672 intype = TREE_TYPE (expr);
4674 if (TREE_CODE (type) == REFERENCE_TYPE)
4676 if (! real_lvalue_p (expr))
4678 error ("invalid reinterpret_cast of an rvalue expression of type `%T' to type `%T'", intype, type);
4679 return error_mark_node;
4681 expr = build_unary_op (ADDR_EXPR, expr, 0);
4682 if (expr != error_mark_node)
4683 expr = build_reinterpret_cast
4684 (build_pointer_type (TREE_TYPE (type)), expr);
4685 if (expr != error_mark_node)
4686 expr = build_indirect_ref (expr, 0);
4689 else if (same_type_ignoring_top_level_qualifiers_p (intype, type))
4690 return build_static_cast (type, expr);
4692 if (TYPE_PTR_P (type) && (TREE_CODE (intype) == INTEGER_TYPE
4693 || TREE_CODE (intype) == ENUMERAL_TYPE))
4695 else if (TREE_CODE (type) == INTEGER_TYPE && TYPE_PTR_P (intype))
4697 if (TYPE_PRECISION (type) < TYPE_PRECISION (intype))
4698 pedwarn ("reinterpret_cast from `%T' to `%T' loses precision",
4701 else if ((TYPE_PTRFN_P (type) && TYPE_PTRFN_P (intype))
4702 || (TYPE_PTRMEMFUNC_P (type) && TYPE_PTRMEMFUNC_P (intype)))
4704 expr = decl_constant_value (expr);
4705 return fold (build1 (NOP_EXPR, type, expr));
4707 else if ((TYPE_PTRMEM_P (type) && TYPE_PTRMEM_P (intype))
4708 || (TYPE_PTROBV_P (type) && TYPE_PTROBV_P (intype)))
4710 check_for_casting_away_constness (intype, type, "reinterpret_cast");
4711 expr = decl_constant_value (expr);
4712 return fold (build1 (NOP_EXPR, type, expr));
4714 else if ((TYPE_PTRFN_P (type) && TYPE_PTROBV_P (intype))
4715 || (TYPE_PTRFN_P (intype) && TYPE_PTROBV_P (type)))
4717 pedwarn ("ISO C++ forbids casting between pointer-to-function and pointer-to-object");
4718 expr = decl_constant_value (expr);
4719 return fold (build1 (NOP_EXPR, type, expr));
4723 error ("invalid reinterpret_cast from type `%T' to type `%T'",
4725 return error_mark_node;
4728 return cp_convert (type, expr);
4732 build_const_cast (tree type, tree expr)
4736 if (type == error_mark_node || expr == error_mark_node)
4737 return error_mark_node;
4739 if (processing_template_decl)
4741 tree t = build_min (CONST_CAST_EXPR, type, expr);
4743 if (!TREE_SIDE_EFFECTS (t)
4744 && type_dependent_expression_p (expr))
4745 /* There might turn out to be side effects inside expr. */
4746 TREE_SIDE_EFFECTS (t) = 1;
4750 if (!POINTER_TYPE_P (type) && !TYPE_PTRMEM_P (type))
4751 error ("invalid use of const_cast with type `%T', which is not a pointer, reference, nor a pointer-to-data-member type", type);
4752 else if (TREE_CODE (TREE_TYPE (type)) == FUNCTION_TYPE)
4754 error ("invalid use of const_cast with type `%T', which is a pointer or reference to a function type", type);
4755 return error_mark_node;
4758 if (TREE_CODE (type) != REFERENCE_TYPE)
4760 expr = decay_conversion (expr);
4762 /* build_c_cast puts on a NOP_EXPR to make the result not an lvalue.
4763 Strip such NOP_EXPRs if VALUE is being used in non-lvalue context. */
4764 if (TREE_CODE (expr) == NOP_EXPR
4765 && TREE_TYPE (expr) == TREE_TYPE (TREE_OPERAND (expr, 0)))
4766 expr = TREE_OPERAND (expr, 0);
4769 intype = TREE_TYPE (expr);
4771 if (same_type_ignoring_top_level_qualifiers_p (intype, type))
4772 return build_static_cast (type, expr);
4773 else if (TREE_CODE (type) == REFERENCE_TYPE)
4775 if (! real_lvalue_p (expr))
4777 error ("invalid const_cast of an rvalue of type `%T' to type `%T'", intype, type);
4778 return error_mark_node;
4781 if (comp_ptr_ttypes_const (TREE_TYPE (type), intype))
4783 expr = build_unary_op (ADDR_EXPR, expr, 0);
4784 expr = build1 (NOP_EXPR, type, expr);
4785 return convert_from_reference (expr);
4788 else if (((TREE_CODE (type) == POINTER_TYPE
4789 && TREE_CODE (intype) == POINTER_TYPE)
4790 || (TYPE_PTRMEM_P (type) && TYPE_PTRMEM_P (intype)))
4791 && comp_ptr_ttypes_const (TREE_TYPE (type), TREE_TYPE (intype)))
4792 return cp_convert (type, expr);
4794 error ("invalid const_cast from type `%T' to type `%T'", intype, type);
4795 return error_mark_node;
4798 /* Build an expression representing a cast to type TYPE of expression EXPR.
4800 ALLOW_NONCONVERTING is true if we should allow non-converting constructors
4801 when doing the cast. */
4804 build_c_cast (tree type, tree expr)
4809 if (type == error_mark_node || expr == error_mark_node)
4810 return error_mark_node;
4812 if (processing_template_decl)
4814 tree t = build_min (CAST_EXPR, type,
4815 tree_cons (NULL_TREE, value, NULL_TREE));
4816 /* We don't know if it will or will not have side effects. */
4817 TREE_SIDE_EFFECTS (t) = 1;
4821 /* build_c_cast puts on a NOP_EXPR to make the result not an lvalue.
4822 Strip such NOP_EXPRs if VALUE is being used in non-lvalue context. */
4823 if (TREE_CODE (type) != REFERENCE_TYPE
4824 && TREE_CODE (value) == NOP_EXPR
4825 && TREE_TYPE (value) == TREE_TYPE (TREE_OPERAND (value, 0)))
4826 value = TREE_OPERAND (value, 0);
4828 if (TREE_CODE (type) == ARRAY_TYPE)
4830 /* Allow casting from T1* to T2[] because Cfront allows it.
4831 NIHCL uses it. It is not valid ISO C++ however. */
4832 if (TREE_CODE (TREE_TYPE (expr)) == POINTER_TYPE)
4834 pedwarn ("ISO C++ forbids casting to an array type `%T'", type);
4835 type = build_pointer_type (TREE_TYPE (type));
4839 error ("ISO C++ forbids casting to an array type `%T'", type);
4840 return error_mark_node;
4844 if (TREE_CODE (type) == FUNCTION_TYPE
4845 || TREE_CODE (type) == METHOD_TYPE)
4847 error ("invalid cast to function type `%T'", type);
4848 return error_mark_node;
4851 if (TREE_CODE (type) == VOID_TYPE)
4853 /* Conversion to void does not cause any of the normal function to
4854 * pointer, array to pointer and lvalue to rvalue decays. */
4856 value = convert_to_void (value, /*implicit=*/NULL);
4860 if (!complete_type_or_else (type, NULL_TREE))
4861 return error_mark_node;
4863 /* Convert functions and arrays to pointers and
4864 convert references to their expanded types,
4865 but don't convert any other types. If, however, we are
4866 casting to a class type, there's no reason to do this: the
4867 cast will only succeed if there is a converting constructor,
4868 and the default conversions will be done at that point. In
4869 fact, doing the default conversion here is actually harmful
4873 struct S { S(const A&); };
4875 since we don't want the array-to-pointer conversion done. */
4876 if (!IS_AGGR_TYPE (type))
4878 if (TREE_CODE (TREE_TYPE (value)) == FUNCTION_TYPE
4879 || (TREE_CODE (TREE_TYPE (value)) == METHOD_TYPE
4880 /* Don't do the default conversion on a ->* expression. */
4881 && ! (TREE_CODE (type) == POINTER_TYPE
4882 && bound_pmf_p (value)))
4883 || TREE_CODE (TREE_TYPE (value)) == ARRAY_TYPE
4884 || TREE_CODE (TREE_TYPE (value)) == REFERENCE_TYPE)
4885 value = decay_conversion (value);
4887 else if (TREE_CODE (TREE_TYPE (value)) == REFERENCE_TYPE)
4888 /* However, even for class types, we still need to strip away
4889 the reference type, since the call to convert_force below
4890 does not expect the input expression to be of reference
4892 value = convert_from_reference (value);
4894 otype = TREE_TYPE (value);
4896 /* Optionally warn about potentially worrisome casts. */
4899 && TREE_CODE (type) == POINTER_TYPE
4900 && TREE_CODE (otype) == POINTER_TYPE
4901 && !at_least_as_qualified_p (TREE_TYPE (type),
4903 warning ("cast from `%T' to `%T' discards qualifiers from pointer target type",
4906 if (TREE_CODE (type) == INTEGER_TYPE
4907 && TYPE_PTR_P (otype)
4908 && TYPE_PRECISION (type) != TYPE_PRECISION (otype))
4909 warning ("cast from pointer to integer of different size");
4911 if (TYPE_PTR_P (type)
4912 && TREE_CODE (otype) == INTEGER_TYPE
4913 && TYPE_PRECISION (type) != TYPE_PRECISION (otype)
4914 /* Don't warn about converting any constant. */
4915 && !TREE_CONSTANT (value))
4916 warning ("cast to pointer from integer of different size");
4918 if (TREE_CODE (type) == REFERENCE_TYPE)
4919 value = (convert_from_reference
4920 (convert_to_reference (type, value, CONV_C_CAST,
4921 LOOKUP_COMPLAIN, NULL_TREE)));
4926 value = decl_constant_value (value);
4929 value = convert_force (type, value, CONV_C_CAST);
4931 /* Ignore any integer overflow caused by the cast. */
4932 if (TREE_CODE (value) == INTEGER_CST)
4934 TREE_OVERFLOW (value) = TREE_OVERFLOW (ovalue);
4936 if (TREE_CODE_CLASS (TREE_CODE (ovalue)) == 'c')
4937 TREE_CONSTANT_OVERFLOW (value) = TREE_CONSTANT_OVERFLOW (ovalue);
4941 /* Warn about possible alignment problems. Do this here when we will have
4942 instantiated any necessary template types. */
4943 if (STRICT_ALIGNMENT && warn_cast_align
4944 && TREE_CODE (type) == POINTER_TYPE
4945 && TREE_CODE (otype) == POINTER_TYPE
4946 && TREE_CODE (TREE_TYPE (otype)) != VOID_TYPE
4947 && TREE_CODE (TREE_TYPE (otype)) != FUNCTION_TYPE
4948 && COMPLETE_TYPE_P (TREE_TYPE (otype))
4949 && COMPLETE_TYPE_P (TREE_TYPE (type))
4950 && TYPE_ALIGN (TREE_TYPE (type)) > TYPE_ALIGN (TREE_TYPE (otype)))
4951 warning ("cast from `%T' to `%T' increases required alignment of target type",
4954 /* Always produce some operator for an explicit cast,
4955 so we can tell (for -pedantic) that the cast is no lvalue. */
4956 if (TREE_CODE (type) != REFERENCE_TYPE && value == expr
4957 && real_lvalue_p (value))
4958 value = non_lvalue (value);
4963 /* Build an assignment expression of lvalue LHS from value RHS.
4964 MODIFYCODE is the code for a binary operator that we use
4965 to combine the old value of LHS with RHS to get the new value.
4966 Or else MODIFYCODE is NOP_EXPR meaning do a simple assignment.
4968 C++: If MODIFYCODE is INIT_EXPR, then leave references unbashed. */
4971 build_modify_expr (tree lhs, enum tree_code modifycode, tree rhs)
4975 tree lhstype = TREE_TYPE (lhs);
4976 tree olhstype = lhstype;
4977 tree olhs = NULL_TREE;
4979 /* Avoid duplicate error messages from operands that had errors. */
4980 if (lhs == error_mark_node || rhs == error_mark_node)
4981 return error_mark_node;
4983 /* Handle control structure constructs used as "lvalues". */
4984 switch (TREE_CODE (lhs))
4986 /* Handle --foo = 5; as these are valid constructs in C++. */
4987 case PREDECREMENT_EXPR:
4988 case PREINCREMENT_EXPR:
4989 if (TREE_SIDE_EFFECTS (TREE_OPERAND (lhs, 0)))
4990 lhs = build (TREE_CODE (lhs), TREE_TYPE (lhs),
4991 stabilize_reference (TREE_OPERAND (lhs, 0)),
4992 TREE_OPERAND (lhs, 1));
4993 return build (COMPOUND_EXPR, lhstype,
4995 build_modify_expr (TREE_OPERAND (lhs, 0),
4998 /* Handle (a, b) used as an "lvalue". */
5000 newrhs = build_modify_expr (TREE_OPERAND (lhs, 1),
5002 if (newrhs == error_mark_node)
5003 return error_mark_node;
5004 return build (COMPOUND_EXPR, lhstype,
5005 TREE_OPERAND (lhs, 0), newrhs);
5008 if (TREE_SIDE_EFFECTS (TREE_OPERAND (lhs, 0)))
5009 lhs = build (TREE_CODE (lhs), TREE_TYPE (lhs),
5010 stabilize_reference (TREE_OPERAND (lhs, 0)),
5011 TREE_OPERAND (lhs, 1));
5012 newrhs = build_modify_expr (TREE_OPERAND (lhs, 0), modifycode, rhs);
5013 if (newrhs == error_mark_node)
5014 return error_mark_node;
5015 return build (COMPOUND_EXPR, lhstype, lhs, newrhs);
5017 /* Handle (a ? b : c) used as an "lvalue". */
5020 /* Produce (a ? (b = rhs) : (c = rhs))
5021 except that the RHS goes through a save-expr
5022 so the code to compute it is only emitted once. */
5024 tree preeval = NULL_TREE;
5026 rhs = stabilize_expr (rhs, &preeval);
5028 /* Check this here to avoid odd errors when trying to convert
5029 a throw to the type of the COND_EXPR. */
5030 if (!lvalue_or_else (lhs, "assignment"))
5031 return error_mark_node;
5033 cond = build_conditional_expr
5034 (TREE_OPERAND (lhs, 0),
5035 build_modify_expr (cp_convert (TREE_TYPE (lhs),
5036 TREE_OPERAND (lhs, 1)),
5038 build_modify_expr (cp_convert (TREE_TYPE (lhs),
5039 TREE_OPERAND (lhs, 2)),
5042 if (cond == error_mark_node)
5044 /* Make sure the code to compute the rhs comes out
5045 before the split. */
5047 cond = build (COMPOUND_EXPR, TREE_TYPE (lhs), preeval, cond);
5055 if (modifycode == INIT_EXPR)
5057 if (TREE_CODE (rhs) == CONSTRUCTOR)
5059 if (! same_type_p (TREE_TYPE (rhs), lhstype))
5060 /* Call convert to generate an error; see PR 11063. */
5061 rhs = convert (lhstype, rhs);
5062 result = build (INIT_EXPR, lhstype, lhs, rhs);
5063 TREE_SIDE_EFFECTS (result) = 1;
5066 else if (! IS_AGGR_TYPE (lhstype))
5067 /* Do the default thing. */;
5070 result = build_special_member_call (lhs, complete_ctor_identifier,
5071 build_tree_list (NULL_TREE, rhs),
5072 TYPE_BINFO (lhstype),
5074 if (result == NULL_TREE)
5075 return error_mark_node;
5081 if (TREE_CODE (lhstype) == REFERENCE_TYPE)
5083 lhs = convert_from_reference (lhs);
5084 olhstype = lhstype = TREE_TYPE (lhs);
5086 lhs = require_complete_type (lhs);
5087 if (lhs == error_mark_node)
5088 return error_mark_node;
5090 if (modifycode == NOP_EXPR)
5092 /* `operator=' is not an inheritable operator. */
5093 if (! IS_AGGR_TYPE (lhstype))
5094 /* Do the default thing. */;
5097 result = build_new_op (MODIFY_EXPR, LOOKUP_NORMAL,
5098 lhs, rhs, make_node (NOP_EXPR),
5099 /*overloaded_p=*/NULL);
5100 if (result == NULL_TREE)
5101 return error_mark_node;
5108 /* A binary op has been requested. Combine the old LHS
5109 value with the RHS producing the value we should actually
5110 store into the LHS. */
5112 my_friendly_assert (!PROMOTES_TO_AGGR_TYPE (lhstype, REFERENCE_TYPE),
5114 lhs = stabilize_reference (lhs);
5115 newrhs = cp_build_binary_op (modifycode, lhs, rhs);
5116 if (newrhs == error_mark_node)
5118 error (" in evaluation of `%Q(%#T, %#T)'", modifycode,
5119 TREE_TYPE (lhs), TREE_TYPE (rhs));
5120 return error_mark_node;
5123 /* Now it looks like a plain assignment. */
5124 modifycode = NOP_EXPR;
5126 my_friendly_assert (TREE_CODE (lhstype) != REFERENCE_TYPE, 20011220);
5127 my_friendly_assert (TREE_CODE (TREE_TYPE (newrhs)) != REFERENCE_TYPE,
5131 /* The left-hand side must be an lvalue. */
5132 if (!lvalue_or_else (lhs, "assignment"))
5133 return error_mark_node;
5135 /* Warn about modifying something that is `const'. Don't warn if
5136 this is initialization. */
5137 if (modifycode != INIT_EXPR
5138 && (TREE_READONLY (lhs) || CP_TYPE_CONST_P (lhstype)
5139 /* Functions are not modifiable, even though they are
5141 || TREE_CODE (TREE_TYPE (lhs)) == FUNCTION_TYPE
5142 || TREE_CODE (TREE_TYPE (lhs)) == METHOD_TYPE
5143 /* If it's an aggregate and any field is const, then it is
5144 effectively const. */
5145 || (CLASS_TYPE_P (lhstype)
5146 && C_TYPE_FIELDS_READONLY (lhstype))))
5147 readonly_error (lhs, "assignment", 0);
5149 /* If storing into a structure or union member, it has probably been
5150 given type `int'. Compute the type that would go with the actual
5151 amount of storage the member occupies. */
5153 if (TREE_CODE (lhs) == COMPONENT_REF
5154 && (TREE_CODE (lhstype) == INTEGER_TYPE
5155 || TREE_CODE (lhstype) == REAL_TYPE
5156 || TREE_CODE (lhstype) == ENUMERAL_TYPE))
5158 lhstype = TREE_TYPE (get_unwidened (lhs, 0));
5160 /* If storing in a field that is in actuality a short or narrower
5161 than one, we must store in the field in its actual type. */
5163 if (lhstype != TREE_TYPE (lhs))
5165 /* Avoid warnings converting integral types back into enums for
5167 if (TREE_CODE (lhstype) == INTEGER_TYPE
5168 && TREE_CODE (olhstype) == ENUMERAL_TYPE)
5170 if (TREE_SIDE_EFFECTS (lhs))
5171 lhs = stabilize_reference (lhs);
5174 lhs = copy_node (lhs);
5175 TREE_TYPE (lhs) = lhstype;
5179 /* Convert new value to destination type. */
5181 if (TREE_CODE (lhstype) == ARRAY_TYPE)
5185 if (!same_or_base_type_p (TYPE_MAIN_VARIANT (lhstype),
5186 TYPE_MAIN_VARIANT (TREE_TYPE (rhs))))
5188 error ("incompatible types in assignment of `%T' to `%T'",
5189 TREE_TYPE (rhs), lhstype);
5190 return error_mark_node;
5193 /* Allow array assignment in compiler-generated code. */
5194 if (! DECL_ARTIFICIAL (current_function_decl))
5195 pedwarn ("ISO C++ forbids assignment of arrays");
5197 from_array = TREE_CODE (TREE_TYPE (newrhs)) == ARRAY_TYPE
5198 ? 1 + (modifycode != INIT_EXPR): 0;
5199 return build_vec_init (lhs, NULL_TREE, newrhs, from_array);
5202 if (modifycode == INIT_EXPR)
5203 newrhs = convert_for_initialization (lhs, lhstype, newrhs, LOOKUP_NORMAL,
5204 "initialization", NULL_TREE, 0);
5207 /* Avoid warnings on enum bit fields. */
5208 if (TREE_CODE (olhstype) == ENUMERAL_TYPE
5209 && TREE_CODE (lhstype) == INTEGER_TYPE)
5211 newrhs = convert_for_assignment (olhstype, newrhs, "assignment",
5213 newrhs = convert_force (lhstype, newrhs, 0);
5216 newrhs = convert_for_assignment (lhstype, newrhs, "assignment",
5218 if (TREE_CODE (newrhs) == CALL_EXPR
5219 && TYPE_NEEDS_CONSTRUCTING (lhstype))
5220 newrhs = build_cplus_new (lhstype, newrhs);
5222 /* Can't initialize directly from a TARGET_EXPR, since that would
5223 cause the lhs to be constructed twice, and possibly result in
5224 accidental self-initialization. So we force the TARGET_EXPR to be
5225 expanded without a target. */
5226 if (TREE_CODE (newrhs) == TARGET_EXPR)
5227 newrhs = build (COMPOUND_EXPR, TREE_TYPE (newrhs), newrhs,
5228 TREE_OPERAND (newrhs, 0));
5231 if (newrhs == error_mark_node)
5232 return error_mark_node;
5234 result = build (modifycode == NOP_EXPR ? MODIFY_EXPR : INIT_EXPR,
5235 lhstype, lhs, newrhs);
5237 TREE_SIDE_EFFECTS (result) = 1;
5239 /* If we got the LHS in a different type for storing in,
5240 convert the result back to the nominal type of LHS
5241 so that the value we return always has the same type
5242 as the LHS argument. */
5244 if (olhstype == TREE_TYPE (result))
5248 result = build (COMPOUND_EXPR, olhstype, result, olhs);
5249 TREE_NO_WARNING (result) = 1;
5252 return convert_for_assignment (olhstype, result, "assignment",
5257 build_x_modify_expr (tree lhs, enum tree_code modifycode, tree rhs)
5259 if (processing_template_decl)
5260 return build_min_nt (MODOP_EXPR, lhs,
5261 build_min_nt (modifycode, NULL_TREE, NULL_TREE), rhs);
5263 if (modifycode != NOP_EXPR)
5265 tree rval = build_new_op (MODIFY_EXPR, LOOKUP_NORMAL, lhs, rhs,
5266 make_node (modifycode),
5267 /*overloaded_p=*/NULL);
5271 return build_modify_expr (lhs, modifycode, rhs);
5275 /* Get difference in deltas for different pointer to member function
5276 types. Returns an integer constant of type PTRDIFF_TYPE_NODE. If
5277 the conversion is invalid, the constant is zero. If FORCE is true,
5278 then allow reverse conversions as well.
5280 Note that the naming of FROM and TO is kind of backwards; the return
5281 value is what we add to a TO in order to get a FROM. They are named
5282 this way because we call this function to find out how to convert from
5283 a pointer to member of FROM to a pointer to member of TO. */
5286 get_delta_difference (tree from, tree to, int force)
5293 /* Assume no conversion is required. */
5294 result = integer_zero_node;
5295 binfo = lookup_base (to, from, ba_check, &kind);
5296 if (kind == bk_inaccessible || kind == bk_ambig)
5297 error (" in pointer to member function conversion");
5302 error_not_base_type (from, to);
5303 error (" in pointer to member conversion");
5307 binfo = lookup_base (from, to, ba_check, &kind);
5310 virt_binfo = binfo_from_vbase (binfo);
5312 /* This is a reinterpret cast, we choose to do nothing. */
5313 warning ("pointer to member cast via virtual base `%T'",
5314 BINFO_TYPE (virt_binfo));
5316 result = size_diffop (size_zero_node, BINFO_OFFSET (binfo));
5322 virt_binfo = binfo_from_vbase (binfo);
5324 result = BINFO_OFFSET (binfo);
5327 /* This is a reinterpret cast, we choose to do nothing. */
5329 warning ("pointer to member cast via virtual base `%T'",
5330 BINFO_TYPE (virt_binfo));
5332 error ("pointer to member conversion via virtual base `%T'",
5333 BINFO_TYPE (virt_binfo));
5337 return fold (convert_to_integer (ptrdiff_type_node, result));
5340 /* Return a constructor for the pointer-to-member-function TYPE using
5341 the other components as specified. */
5344 build_ptrmemfunc1 (tree type, tree delta, tree pfn)
5350 /* Pull the FIELD_DECLs out of the type. */
5351 pfn_field = TYPE_FIELDS (type);
5352 delta_field = TREE_CHAIN (pfn_field);
5354 /* Make sure DELTA has the type we want. */
5355 delta = convert_and_check (delta_type_node, delta);
5357 /* Finish creating the initializer. */
5358 u = tree_cons (pfn_field, pfn,
5359 build_tree_list (delta_field, delta));
5360 u = build_constructor (type, u);
5361 TREE_CONSTANT (u) = TREE_CONSTANT (pfn) & TREE_CONSTANT (delta);
5362 TREE_INVARIANT (u) = TREE_INVARIANT (pfn) & TREE_INVARIANT (delta);
5363 TREE_STATIC (u) = (TREE_CONSTANT (u)
5364 && (initializer_constant_valid_p (pfn, TREE_TYPE (pfn))
5366 && (initializer_constant_valid_p (delta, TREE_TYPE (delta))
5371 /* Build a constructor for a pointer to member function. It can be
5372 used to initialize global variables, local variable, or used
5373 as a value in expressions. TYPE is the POINTER to METHOD_TYPE we
5376 If FORCE is nonzero, then force this conversion, even if
5377 we would rather not do it. Usually set when using an explicit
5380 Return error_mark_node, if something goes wrong. */
5383 build_ptrmemfunc (tree type, tree pfn, int force)
5389 if (error_operand_p (pfn))
5390 return error_mark_node;
5392 pfn_type = TREE_TYPE (pfn);
5393 to_type = build_ptrmemfunc_type (type);
5395 /* Handle multiple conversions of pointer to member functions. */
5396 if (TYPE_PTRMEMFUNC_P (pfn_type))
5398 tree delta = NULL_TREE;
5399 tree npfn = NULL_TREE;
5403 && !can_convert_arg (to_type, TREE_TYPE (pfn), pfn))
5404 error ("invalid conversion to type `%T' from type `%T'",
5407 n = get_delta_difference (TYPE_PTRMEMFUNC_OBJECT_TYPE (pfn_type),
5408 TYPE_PTRMEMFUNC_OBJECT_TYPE (to_type),
5411 /* We don't have to do any conversion to convert a
5412 pointer-to-member to its own type. But, we don't want to
5413 just return a PTRMEM_CST if there's an explicit cast; that
5414 cast should make the expression an invalid template argument. */
5415 if (TREE_CODE (pfn) != PTRMEM_CST)
5417 if (same_type_p (to_type, pfn_type))
5419 else if (integer_zerop (n))
5420 return build_reinterpret_cast (to_type, pfn);
5423 if (TREE_SIDE_EFFECTS (pfn))
5424 pfn = save_expr (pfn);
5426 /* Obtain the function pointer and the current DELTA. */
5427 if (TREE_CODE (pfn) == PTRMEM_CST)
5428 expand_ptrmemfunc_cst (pfn, &delta, &npfn);
5431 npfn = build_ptrmemfunc_access_expr (pfn, pfn_identifier);
5432 delta = build_ptrmemfunc_access_expr (pfn, delta_identifier);
5435 /* Just adjust the DELTA field. */
5436 my_friendly_assert (TREE_TYPE (delta) == ptrdiff_type_node, 20030727);
5437 if (TARGET_PTRMEMFUNC_VBIT_LOCATION == ptrmemfunc_vbit_in_delta)
5438 n = cp_build_binary_op (LSHIFT_EXPR, n, integer_one_node);
5439 delta = cp_build_binary_op (PLUS_EXPR, delta, n);
5440 return build_ptrmemfunc1 (to_type, delta, npfn);
5443 /* Handle null pointer to member function conversions. */
5444 if (integer_zerop (pfn))
5446 pfn = build_c_cast (type, integer_zero_node);
5447 return build_ptrmemfunc1 (to_type,
5452 if (type_unknown_p (pfn))
5453 return instantiate_type (type, pfn, tf_error | tf_warning);
5455 fn = TREE_OPERAND (pfn, 0);
5456 my_friendly_assert (TREE_CODE (fn) == FUNCTION_DECL, 0);
5457 return make_ptrmem_cst (to_type, fn);
5460 /* Return the DELTA, IDX, PFN, and DELTA2 values for the PTRMEM_CST
5463 ??? There is no consistency as to the types returned for the above
5464 values. Some code acts as if it were a sizetype and some as if it were
5465 integer_type_node. */
5468 expand_ptrmemfunc_cst (tree cst, tree *delta, tree *pfn)
5470 tree type = TREE_TYPE (cst);
5471 tree fn = PTRMEM_CST_MEMBER (cst);
5472 tree ptr_class, fn_class;
5474 my_friendly_assert (TREE_CODE (fn) == FUNCTION_DECL, 0);
5476 /* The class that the function belongs to. */
5477 fn_class = DECL_CONTEXT (fn);
5479 /* The class that we're creating a pointer to member of. */
5480 ptr_class = TYPE_PTRMEMFUNC_OBJECT_TYPE (type);
5482 /* First, calculate the adjustment to the function's class. */
5483 *delta = get_delta_difference (fn_class, ptr_class, /*force=*/0);
5485 if (!DECL_VIRTUAL_P (fn))
5486 *pfn = convert (TYPE_PTRMEMFUNC_FN_TYPE (type), build_addr_func (fn));
5489 /* If we're dealing with a virtual function, we have to adjust 'this'
5490 again, to point to the base which provides the vtable entry for
5491 fn; the call will do the opposite adjustment. */
5492 tree orig_class = DECL_CONTEXT (fn);
5493 tree binfo = binfo_or_else (orig_class, fn_class);
5494 *delta = fold (build (PLUS_EXPR, TREE_TYPE (*delta),
5495 *delta, BINFO_OFFSET (binfo)));
5497 /* We set PFN to the vtable offset at which the function can be
5498 found, plus one (unless ptrmemfunc_vbit_in_delta, in which
5499 case delta is shifted left, and then incremented). */
5500 *pfn = DECL_VINDEX (fn);
5501 *pfn = fold (build (MULT_EXPR, integer_type_node, *pfn,
5502 TYPE_SIZE_UNIT (vtable_entry_type)));
5504 switch (TARGET_PTRMEMFUNC_VBIT_LOCATION)
5506 case ptrmemfunc_vbit_in_pfn:
5507 *pfn = fold (build (PLUS_EXPR, integer_type_node, *pfn,
5511 case ptrmemfunc_vbit_in_delta:
5512 *delta = fold (build (LSHIFT_EXPR, TREE_TYPE (*delta),
5513 *delta, integer_one_node));
5514 *delta = fold (build (PLUS_EXPR, TREE_TYPE (*delta),
5515 *delta, integer_one_node));
5522 *pfn = fold (build1 (NOP_EXPR, TYPE_PTRMEMFUNC_FN_TYPE (type),
5527 /* Return an expression for PFN from the pointer-to-member function
5531 pfn_from_ptrmemfunc (tree t)
5533 if (TREE_CODE (t) == PTRMEM_CST)
5538 expand_ptrmemfunc_cst (t, &delta, &pfn);
5543 return build_ptrmemfunc_access_expr (t, pfn_identifier);
5546 /* Expression EXPR is about to be implicitly converted to TYPE. Warn
5547 if this is a potentially dangerous thing to do. Returns a possibly
5551 dubious_conversion_warnings (tree type, tree expr,
5552 const char *errtype, tree fndecl, int parmnum)
5554 type = non_reference (type);
5556 /* Issue warnings about peculiar, but valid, uses of NULL. */
5557 if (ARITHMETIC_TYPE_P (type) && expr == null_node)
5560 warning ("passing NULL used for non-pointer %s %P of `%D'",
5561 errtype, parmnum, fndecl);
5563 warning ("%s to non-pointer type `%T' from NULL", errtype, type);
5566 /* Warn about assigning a floating-point type to an integer type. */
5567 if (TREE_CODE (TREE_TYPE (expr)) == REAL_TYPE
5568 && TREE_CODE (type) == INTEGER_TYPE)
5571 warning ("passing `%T' for %s %P of `%D'",
5572 TREE_TYPE (expr), errtype, parmnum, fndecl);
5574 warning ("%s to `%T' from `%T'", errtype, type, TREE_TYPE (expr));
5576 /* And warn about assigning a negative value to an unsigned
5578 else if (TYPE_UNSIGNED (type) && TREE_CODE (type) != BOOLEAN_TYPE)
5580 if (TREE_CODE (expr) == INTEGER_CST && TREE_NEGATED_INT (expr))
5583 warning ("passing negative value `%E' for %s %P of `%D'",
5584 expr, errtype, parmnum, fndecl);
5586 warning ("%s of negative value `%E' to `%T'",
5587 errtype, expr, type);
5590 overflow_warning (expr);
5592 if (TREE_CONSTANT (expr))
5598 /* Convert value RHS to type TYPE as preparation for an assignment to
5599 an lvalue of type TYPE. ERRTYPE is a string to use in error
5600 messages: "assignment", "return", etc. If FNDECL is non-NULL, we
5601 are doing the conversion in order to pass the PARMNUMth argument of
5605 convert_for_assignment (tree type, tree rhs,
5606 const char *errtype, tree fndecl, int parmnum)
5609 enum tree_code coder;
5611 /* Strip NON_LVALUE_EXPRs since we aren't using as an lvalue. */
5612 if (TREE_CODE (rhs) == NON_LVALUE_EXPR)
5613 rhs = TREE_OPERAND (rhs, 0);
5615 rhstype = TREE_TYPE (rhs);
5616 coder = TREE_CODE (rhstype);
5618 if (TREE_CODE (type) == VECTOR_TYPE && coder == VECTOR_TYPE
5619 && vector_types_convertible_p (type, rhstype))
5620 return convert (type, rhs);
5622 if (rhs == error_mark_node || rhstype == error_mark_node)
5623 return error_mark_node;
5624 if (TREE_CODE (rhs) == TREE_LIST && TREE_VALUE (rhs) == error_mark_node)
5625 return error_mark_node;
5627 /* The RHS of an assignment cannot have void type. */
5628 if (coder == VOID_TYPE)
5630 error ("void value not ignored as it ought to be");
5631 return error_mark_node;
5634 /* Simplify the RHS if possible. */
5635 if (TREE_CODE (rhs) == CONST_DECL)
5636 rhs = DECL_INITIAL (rhs);
5638 /* We do not use decl_constant_value here because of this case:
5640 const char* const s = "s";
5642 The conversion rules for a string literal are more lax than for a
5643 variable; in particular, a string literal can be converted to a
5644 "char *" but the variable "s" cannot be converted in the same
5645 way. If the conversion is allowed, the optimization should be
5646 performed while creating the converted expression. */
5650 The expression is implicitly converted (clause _conv_) to the
5651 cv-unqualified type of the left operand.
5653 We allow bad conversions here because by the time we get to this point
5654 we are committed to doing the conversion. If we end up doing a bad
5655 conversion, convert_like will complain. */
5656 if (!can_convert_arg_bad (type, rhstype, rhs))
5658 /* When -Wno-pmf-conversions is use, we just silently allow
5659 conversions from pointers-to-members to plain pointers. If
5660 the conversion doesn't work, cp_convert will complain. */
5662 && TYPE_PTR_P (type)
5663 && TYPE_PTRMEMFUNC_P (rhstype))
5664 rhs = cp_convert (strip_top_quals (type), rhs);
5667 /* If the right-hand side has unknown type, then it is an
5668 overloaded function. Call instantiate_type to get error
5670 if (rhstype == unknown_type_node)
5671 instantiate_type (type, rhs, tf_error | tf_warning);
5673 error ("cannot convert `%T' to `%T' for argument `%P' to `%D'",
5674 rhstype, type, parmnum, fndecl);
5676 error ("cannot convert `%T' to `%T' in %s", rhstype, type,
5678 return error_mark_node;
5681 return perform_implicit_conversion (strip_top_quals (type), rhs);
5684 /* Convert RHS to be of type TYPE.
5685 If EXP is nonzero, it is the target of the initialization.
5686 ERRTYPE is a string to use in error messages.
5688 Two major differences between the behavior of
5689 `convert_for_assignment' and `convert_for_initialization'
5690 are that references are bashed in the former, while
5691 copied in the latter, and aggregates are assigned in
5692 the former (operator=) while initialized in the
5695 If using constructor make sure no conversion operator exists, if one does
5696 exist, an ambiguity exists.
5698 If flags doesn't include LOOKUP_COMPLAIN, don't complain about anything. */
5701 convert_for_initialization (tree exp, tree type, tree rhs, int flags,
5702 const char *errtype, tree fndecl, int parmnum)
5704 enum tree_code codel = TREE_CODE (type);
5706 enum tree_code coder;
5708 /* build_c_cast puts on a NOP_EXPR to make the result not an lvalue.
5709 Strip such NOP_EXPRs, since RHS is used in non-lvalue context. */
5710 if (TREE_CODE (rhs) == NOP_EXPR
5711 && TREE_TYPE (rhs) == TREE_TYPE (TREE_OPERAND (rhs, 0))
5712 && codel != REFERENCE_TYPE)
5713 rhs = TREE_OPERAND (rhs, 0);
5715 if (rhs == error_mark_node
5716 || (TREE_CODE (rhs) == TREE_LIST && TREE_VALUE (rhs) == error_mark_node))
5717 return error_mark_node;
5719 if (TREE_CODE (TREE_TYPE (rhs)) == REFERENCE_TYPE)
5720 rhs = convert_from_reference (rhs);
5722 if ((TREE_CODE (TREE_TYPE (rhs)) == ARRAY_TYPE
5723 && TREE_CODE (type) != ARRAY_TYPE
5724 && (TREE_CODE (type) != REFERENCE_TYPE
5725 || TREE_CODE (TREE_TYPE (type)) != ARRAY_TYPE))
5726 || (TREE_CODE (TREE_TYPE (rhs)) == FUNCTION_TYPE
5727 && (TREE_CODE (type) != REFERENCE_TYPE
5728 || TREE_CODE (TREE_TYPE (type)) != FUNCTION_TYPE))
5729 || TREE_CODE (TREE_TYPE (rhs)) == METHOD_TYPE)
5730 rhs = decay_conversion (rhs);
5732 rhstype = TREE_TYPE (rhs);
5733 coder = TREE_CODE (rhstype);
5735 if (coder == ERROR_MARK)
5736 return error_mark_node;
5738 /* We accept references to incomplete types, so we can
5739 return here before checking if RHS is of complete type. */
5741 if (codel == REFERENCE_TYPE)
5743 /* This should eventually happen in convert_arguments. */
5744 int savew = 0, savee = 0;
5747 savew = warningcount, savee = errorcount;
5748 rhs = initialize_reference (type, rhs, /*decl=*/NULL_TREE,
5752 if (warningcount > savew)
5753 cp_warning_at ("in passing argument %P of `%+D'", parmnum, fndecl);
5754 else if (errorcount > savee)
5755 cp_error_at ("in passing argument %P of `%+D'", parmnum, fndecl);
5761 exp = require_complete_type (exp);
5762 if (exp == error_mark_node)
5763 return error_mark_node;
5765 rhstype = non_reference (rhstype);
5767 type = complete_type (type);
5769 if (IS_AGGR_TYPE (type))
5770 return ocp_convert (type, rhs, CONV_IMPLICIT|CONV_FORCE_TEMP, flags);
5772 return convert_for_assignment (type, rhs, errtype, fndecl, parmnum);
5775 /* Expand an ASM statement with operands, handling output operands
5776 that are not variables or INDIRECT_REFS by transforming such
5777 cases into cases that expand_asm_operands can handle.
5779 Arguments are same as for expand_asm_operands.
5781 We don't do default conversions on all inputs, because it can screw
5782 up operands that are expected to be in memory. */
5785 c_expand_asm_operands (tree string, tree outputs, tree inputs, tree clobbers,
5786 int vol, location_t locus)
5788 int noutputs = list_length (outputs);
5790 /* o[I] is the place that output number I should be written. */
5791 tree *o = alloca (noutputs * sizeof (tree));
5794 /* Record the contents of OUTPUTS before it is modified. */
5795 for (i = 0, tail = outputs; tail; tail = TREE_CHAIN (tail), i++)
5796 o[i] = TREE_VALUE (tail);
5798 /* Generate the ASM_OPERANDS insn;
5799 store into the TREE_VALUEs of OUTPUTS some trees for
5800 where the values were actually stored. */
5801 expand_asm_operands (string, outputs, inputs, clobbers, vol, locus);
5803 /* Copy all the intermediate outputs into the specified outputs. */
5804 for (i = 0, tail = outputs; tail; tail = TREE_CHAIN (tail), i++)
5806 if (o[i] != TREE_VALUE (tail))
5808 expand_expr (build_modify_expr (o[i], NOP_EXPR, TREE_VALUE (tail)),
5809 const0_rtx, VOIDmode, EXPAND_NORMAL);
5812 /* Restore the original value so that it's correct the next
5813 time we expand this function. */
5814 TREE_VALUE (tail) = o[i];
5816 /* Detect modification of read-only values.
5817 (Otherwise done by build_modify_expr.) */
5820 tree type = TREE_TYPE (o[i]);
5821 if (type != error_mark_node
5822 && (CP_TYPE_CONST_P (type)
5823 || (CLASS_TYPE_P (type) && C_TYPE_FIELDS_READONLY (type))))
5824 readonly_error (o[i], "modification by `asm'", 1);
5828 /* Those MODIFY_EXPRs could do autoincrements. */
5832 /* If RETVAL is the address of, or a reference to, a local variable or
5833 temporary give an appropriate warning. */
5836 maybe_warn_about_returning_address_of_local (tree retval)
5838 tree valtype = TREE_TYPE (DECL_RESULT (current_function_decl));
5839 tree whats_returned = retval;
5843 if (TREE_CODE (whats_returned) == COMPOUND_EXPR)
5844 whats_returned = TREE_OPERAND (whats_returned, 1);
5845 else if (TREE_CODE (whats_returned) == CONVERT_EXPR
5846 || TREE_CODE (whats_returned) == NON_LVALUE_EXPR
5847 || TREE_CODE (whats_returned) == NOP_EXPR)
5848 whats_returned = TREE_OPERAND (whats_returned, 0);
5853 if (TREE_CODE (whats_returned) != ADDR_EXPR)
5855 whats_returned = TREE_OPERAND (whats_returned, 0);
5857 if (TREE_CODE (valtype) == REFERENCE_TYPE)
5859 if (TREE_CODE (whats_returned) == AGGR_INIT_EXPR
5860 || TREE_CODE (whats_returned) == TARGET_EXPR)
5862 warning ("returning reference to temporary");
5865 if (TREE_CODE (whats_returned) == VAR_DECL
5866 && DECL_NAME (whats_returned)
5867 && TEMP_NAME_P (DECL_NAME (whats_returned)))
5869 warning ("reference to non-lvalue returned");
5874 if (DECL_P (whats_returned)
5875 && DECL_NAME (whats_returned)
5876 && DECL_FUNCTION_SCOPE_P (whats_returned)
5877 && !(TREE_STATIC (whats_returned)
5878 || TREE_PUBLIC (whats_returned)))
5880 if (TREE_CODE (valtype) == REFERENCE_TYPE)
5881 cp_warning_at ("reference to local variable `%D' returned",
5884 cp_warning_at ("address of local variable `%D' returned",
5890 /* Check that returning RETVAL from the current function is valid.
5891 Return an expression explicitly showing all conversions required to
5892 change RETVAL into the function return type, and to assign it to
5893 the DECL_RESULT for the function. */
5896 check_return_expr (tree retval)
5899 /* The type actually returned by the function, after any
5902 int fn_returns_value_p;
5904 /* A `volatile' function is one that isn't supposed to return, ever.
5905 (This is a G++ extension, used to get better code for functions
5906 that call the `volatile' function.) */
5907 if (TREE_THIS_VOLATILE (current_function_decl))
5908 warning ("function declared `noreturn' has a `return' statement");
5910 /* Check for various simple errors. */
5911 if (DECL_DESTRUCTOR_P (current_function_decl))
5914 error ("returning a value from a destructor");
5917 else if (DECL_CONSTRUCTOR_P (current_function_decl))
5919 if (in_function_try_handler)
5920 /* If a return statement appears in a handler of the
5921 function-try-block of a constructor, the program is ill-formed. */
5922 error ("cannot return from a handler of a function-try-block of a constructor");
5924 /* You can't return a value from a constructor. */
5925 error ("returning a value from a constructor");
5929 if (processing_template_decl)
5931 current_function_returns_value = 1;
5935 /* When no explicit return-value is given in a function with a named
5936 return value, the named return value is used. */
5937 result = DECL_RESULT (current_function_decl);
5938 valtype = TREE_TYPE (result);
5939 my_friendly_assert (valtype != NULL_TREE, 19990924);
5940 fn_returns_value_p = !VOID_TYPE_P (valtype);
5941 if (!retval && DECL_NAME (result) && fn_returns_value_p)
5944 /* Check for a return statement with no return value in a function
5945 that's supposed to return a value. */
5946 if (!retval && fn_returns_value_p)
5948 pedwarn ("return-statement with no value, in function returning '%T'",
5950 /* Clear this, so finish_function won't say that we reach the
5951 end of a non-void function (which we don't, we gave a
5953 current_function_returns_null = 0;
5955 /* Check for a return statement with a value in a function that
5956 isn't supposed to return a value. */
5957 else if (retval && !fn_returns_value_p)
5959 if (VOID_TYPE_P (TREE_TYPE (retval)))
5960 /* You can return a `void' value from a function of `void'
5961 type. In that case, we have to evaluate the expression for
5962 its side-effects. */
5963 finish_expr_stmt (retval);
5965 pedwarn ("return-statement with a value, in function "
5966 "returning 'void'");
5968 current_function_returns_null = 1;
5970 /* There's really no value to return, after all. */
5974 /* Remember that this function can sometimes return without a
5976 current_function_returns_null = 1;
5978 /* Remember that this function did return a value. */
5979 current_function_returns_value = 1;
5981 /* Only operator new(...) throw(), can return NULL [expr.new/13]. */
5982 if ((DECL_OVERLOADED_OPERATOR_P (current_function_decl) == NEW_EXPR
5983 || DECL_OVERLOADED_OPERATOR_P (current_function_decl) == VEC_NEW_EXPR)
5984 && !TYPE_NOTHROW_P (TREE_TYPE (current_function_decl))
5986 && null_ptr_cst_p (retval))
5987 warning ("`operator new' must not return NULL unless it is declared `throw()' (or -fcheck-new is in effect)");
5989 /* Effective C++ rule 15. See also start_function. */
5991 && DECL_NAME (current_function_decl) == ansi_assopname(NOP_EXPR)
5992 && retval != current_class_ref)
5993 warning ("`operator=' should return a reference to `*this'");
5995 /* The fabled Named Return Value optimization, as per [class.copy]/15:
5997 [...] For a function with a class return type, if the expression
5998 in the return statement is the name of a local object, and the cv-
5999 unqualified type of the local object is the same as the function
6000 return type, an implementation is permitted to omit creating the tem-
6001 porary object to hold the function return value [...]
6003 So, if this is a value-returning function that always returns the same
6004 local variable, remember it.
6006 It might be nice to be more flexible, and choose the first suitable
6007 variable even if the function sometimes returns something else, but
6008 then we run the risk of clobbering the variable we chose if the other
6009 returned expression uses the chosen variable somehow. And people expect
6010 this restriction, anyway. (jason 2000-11-19)
6012 See finish_function and finalize_nrv for the rest of this optimization. */
6014 if (fn_returns_value_p && flag_elide_constructors)
6016 if (retval != NULL_TREE
6017 && (current_function_return_value == NULL_TREE
6018 || current_function_return_value == retval)
6019 && TREE_CODE (retval) == VAR_DECL
6020 && DECL_CONTEXT (retval) == current_function_decl
6021 && ! TREE_STATIC (retval)
6022 && (DECL_ALIGN (retval)
6023 >= DECL_ALIGN (DECL_RESULT (current_function_decl)))
6024 && same_type_p ((TYPE_MAIN_VARIANT
6025 (TREE_TYPE (retval))),
6027 (TREE_TYPE (TREE_TYPE (current_function_decl))))))
6028 current_function_return_value = retval;
6030 current_function_return_value = error_mark_node;
6033 /* We don't need to do any conversions when there's nothing being
6035 if (!retval || retval == error_mark_node)
6038 /* Do any required conversions. */
6039 if (retval == result || DECL_CONSTRUCTOR_P (current_function_decl))
6040 /* No conversions are required. */
6044 /* The type the function is declared to return. */
6045 tree functype = TREE_TYPE (TREE_TYPE (current_function_decl));
6047 /* First convert the value to the function's return type, then
6048 to the type of return value's location to handle the
6049 case that functype is smaller than the valtype. */
6050 retval = convert_for_initialization
6051 (NULL_TREE, functype, retval, LOOKUP_NORMAL|LOOKUP_ONLYCONVERTING,
6052 "return", NULL_TREE, 0);
6053 retval = convert (valtype, retval);
6055 /* If the conversion failed, treat this just like `return;'. */
6056 if (retval == error_mark_node)
6058 /* We can't initialize a register from a AGGR_INIT_EXPR. */
6059 else if (! current_function_returns_struct
6060 && TREE_CODE (retval) == TARGET_EXPR
6061 && TREE_CODE (TREE_OPERAND (retval, 1)) == AGGR_INIT_EXPR)
6062 retval = build (COMPOUND_EXPR, TREE_TYPE (retval), retval,
6063 TREE_OPERAND (retval, 0));
6065 maybe_warn_about_returning_address_of_local (retval);
6068 /* Actually copy the value returned into the appropriate location. */
6069 if (retval && retval != result)
6070 retval = build (INIT_EXPR, TREE_TYPE (result), result, retval);
6076 /* Returns nonzero if the pointer-type FROM can be converted to the
6077 pointer-type TO via a qualification conversion. If CONSTP is -1,
6078 then we return nonzero if the pointers are similar, and the
6079 cv-qualification signature of FROM is a proper subset of that of TO.
6081 If CONSTP is positive, then all outer pointers have been
6085 comp_ptr_ttypes_real (tree to, tree from, int constp)
6087 bool to_more_cv_qualified = false;
6089 for (; ; to = TREE_TYPE (to), from = TREE_TYPE (from))
6091 if (TREE_CODE (to) != TREE_CODE (from))
6094 if (TREE_CODE (from) == OFFSET_TYPE
6095 && !same_type_p (TYPE_OFFSET_BASETYPE (from),
6096 TYPE_OFFSET_BASETYPE (to)))
6099 /* Const and volatile mean something different for function types,
6100 so the usual checks are not appropriate. */
6101 if (TREE_CODE (to) != FUNCTION_TYPE && TREE_CODE (to) != METHOD_TYPE)
6103 if (!at_least_as_qualified_p (to, from))
6106 if (!at_least_as_qualified_p (from, to))
6110 to_more_cv_qualified = true;
6114 constp &= TYPE_READONLY (to);
6117 if (TREE_CODE (to) != POINTER_TYPE && !TYPE_PTRMEM_P (to))
6118 return ((constp >= 0 || to_more_cv_qualified)
6119 && same_type_ignoring_top_level_qualifiers_p (to, from));
6123 /* When comparing, say, char ** to char const **, this function takes
6124 the 'char *' and 'char const *'. Do not pass non-pointer/reference
6125 types to this function. */
6128 comp_ptr_ttypes (tree to, tree from)
6130 return comp_ptr_ttypes_real (to, from, 1);
6133 /* Returns 1 if to and from are (possibly multi-level) pointers to the same
6134 type or inheritance-related types, regardless of cv-quals. */
6137 ptr_reasonably_similar (tree to, tree from)
6139 for (; ; to = TREE_TYPE (to), from = TREE_TYPE (from))
6141 /* Any target type is similar enough to void. */
6142 if (TREE_CODE (to) == VOID_TYPE
6143 || TREE_CODE (from) == VOID_TYPE)
6146 if (TREE_CODE (to) != TREE_CODE (from))
6149 if (TREE_CODE (from) == OFFSET_TYPE
6150 && comptypes (TYPE_OFFSET_BASETYPE (to),
6151 TYPE_OFFSET_BASETYPE (from),
6152 COMPARE_BASE | COMPARE_DERIVED))
6155 if (TREE_CODE (to) == INTEGER_TYPE
6156 && TYPE_PRECISION (to) == TYPE_PRECISION (from))
6159 if (TREE_CODE (to) == FUNCTION_TYPE)
6162 if (TREE_CODE (to) != POINTER_TYPE)
6164 (TYPE_MAIN_VARIANT (to), TYPE_MAIN_VARIANT (from),
6165 COMPARE_BASE | COMPARE_DERIVED);
6169 /* Like comp_ptr_ttypes, for const_cast. */
6172 comp_ptr_ttypes_const (tree to, tree from)
6174 for (; ; to = TREE_TYPE (to), from = TREE_TYPE (from))
6176 if (TREE_CODE (to) != TREE_CODE (from))
6179 if (TREE_CODE (from) == OFFSET_TYPE
6180 && same_type_p (TYPE_OFFSET_BASETYPE (from),
6181 TYPE_OFFSET_BASETYPE (to)))
6184 if (TREE_CODE (to) != POINTER_TYPE)
6185 return same_type_ignoring_top_level_qualifiers_p (to, from);
6189 /* Returns the type qualifiers for this type, including the qualifiers on the
6190 elements for an array type. */
6193 cp_type_quals (tree type)
6195 type = strip_array_types (type);
6196 if (type == error_mark_node)
6197 return TYPE_UNQUALIFIED;
6198 return TYPE_QUALS (type);
6201 /* Returns nonzero if the TYPE contains a mutable member. */
6204 cp_has_mutable_p (tree type)
6206 type = strip_array_types (type);
6208 return CLASS_TYPE_P (type) && CLASSTYPE_HAS_MUTABLE (type);
6211 /* Subroutine of casts_away_constness. Make T1 and T2 point at
6212 exemplar types such that casting T1 to T2 is casting away castness
6213 if and only if there is no implicit conversion from T1 to T2. */
6216 casts_away_constness_r (tree *t1, tree *t2)
6221 /* [expr.const.cast]
6223 For multi-level pointer to members and multi-level mixed pointers
6224 and pointers to members (conv.qual), the "member" aspect of a
6225 pointer to member level is ignored when determining if a const
6226 cv-qualifier has been cast away. */
6227 if (TYPE_PTRMEM_P (*t1))
6228 *t1 = build_pointer_type (TYPE_PTRMEM_POINTED_TO_TYPE (*t1));
6229 if (TYPE_PTRMEM_P (*t2))
6230 *t2 = build_pointer_type (TYPE_PTRMEM_POINTED_TO_TYPE (*t2));
6232 /* [expr.const.cast]
6234 For two pointer types:
6236 X1 is T1cv1,1 * ... cv1,N * where T1 is not a pointer type
6237 X2 is T2cv2,1 * ... cv2,M * where T2 is not a pointer type
6240 casting from X1 to X2 casts away constness if, for a non-pointer
6241 type T there does not exist an implicit conversion (clause
6244 Tcv1,(N-K+1) * cv1,(N-K+2) * ... cv1,N *
6248 Tcv2,(M-K+1) * cv2,(M-K+2) * ... cv2,M *. */
6250 if (TREE_CODE (*t1) != POINTER_TYPE
6251 || TREE_CODE (*t2) != POINTER_TYPE)
6253 *t1 = cp_build_qualified_type (void_type_node,
6254 cp_type_quals (*t1));
6255 *t2 = cp_build_qualified_type (void_type_node,
6256 cp_type_quals (*t2));
6260 quals1 = cp_type_quals (*t1);
6261 quals2 = cp_type_quals (*t2);
6262 *t1 = TREE_TYPE (*t1);
6263 *t2 = TREE_TYPE (*t2);
6264 casts_away_constness_r (t1, t2);
6265 *t1 = build_pointer_type (*t1);
6266 *t2 = build_pointer_type (*t2);
6267 *t1 = cp_build_qualified_type (*t1, quals1);
6268 *t2 = cp_build_qualified_type (*t2, quals2);
6271 /* Returns nonzero if casting from TYPE1 to TYPE2 casts away
6275 casts_away_constness (tree t1, tree t2)
6277 if (TREE_CODE (t2) == REFERENCE_TYPE)
6279 /* [expr.const.cast]
6281 Casting from an lvalue of type T1 to an lvalue of type T2
6282 using a reference cast casts away constness if a cast from an
6283 rvalue of type "pointer to T1" to the type "pointer to T2"
6284 casts away constness. */
6285 t1 = (TREE_CODE (t1) == REFERENCE_TYPE ? TREE_TYPE (t1) : t1);
6286 return casts_away_constness (build_pointer_type (t1),
6287 build_pointer_type (TREE_TYPE (t2)));
6290 if (TYPE_PTRMEM_P (t1) && TYPE_PTRMEM_P (t2))
6291 /* [expr.const.cast]
6293 Casting from an rvalue of type "pointer to data member of X
6294 of type T1" to the type "pointer to data member of Y of type
6295 T2" casts away constness if a cast from an rvalue of type
6296 "pointer to T1" to the type "pointer to T2" casts away
6298 return casts_away_constness
6299 (build_pointer_type (TYPE_PTRMEM_POINTED_TO_TYPE (t1)),
6300 build_pointer_type (TYPE_PTRMEM_POINTED_TO_TYPE (t2)));
6302 /* Casting away constness is only something that makes sense for
6303 pointer or reference types. */
6304 if (TREE_CODE (t1) != POINTER_TYPE
6305 || TREE_CODE (t2) != POINTER_TYPE)
6308 /* Top-level qualifiers don't matter. */
6309 t1 = TYPE_MAIN_VARIANT (t1);
6310 t2 = TYPE_MAIN_VARIANT (t2);
6311 casts_away_constness_r (&t1, &t2);
6312 if (!can_convert (t2, t1))
6318 /* If T is a REFERENCE_TYPE return the type to which T refers.
6319 Otherwise, return T itself. */
6322 non_reference (tree t)
6324 if (TREE_CODE (t) == REFERENCE_TYPE)