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 gcc_assert (ARITHMETIC_TYPE_P (t1)
266 || TREE_CODE (t1) == COMPLEX_TYPE
267 || TREE_CODE (t1) == ENUMERAL_TYPE);
268 gcc_assert (ARITHMETIC_TYPE_P (t2)
269 || TREE_CODE (t2) == COMPLEX_TYPE
270 || TREE_CODE (t2) == ENUMERAL_TYPE);
272 /* In what follows, we slightly generalize the rules given in [expr] so
273 as to deal with `long long' and `complex'. First, merge the
275 attributes = (*targetm.merge_type_attributes) (t1, t2);
277 /* If one type is complex, form the common type of the non-complex
278 components, then make that complex. Use T1 or T2 if it is the
280 if (code1 == COMPLEX_TYPE || code2 == COMPLEX_TYPE)
282 tree subtype1 = code1 == COMPLEX_TYPE ? TREE_TYPE (t1) : t1;
283 tree subtype2 = code2 == COMPLEX_TYPE ? TREE_TYPE (t2) : t2;
285 = type_after_usual_arithmetic_conversions (subtype1, subtype2);
287 if (code1 == COMPLEX_TYPE && TREE_TYPE (t1) == subtype)
288 return build_type_attribute_variant (t1, attributes);
289 else if (code2 == COMPLEX_TYPE && TREE_TYPE (t2) == subtype)
290 return build_type_attribute_variant (t2, attributes);
292 return build_type_attribute_variant (build_complex_type (subtype),
296 /* If only one is real, use it as the result. */
297 if (code1 == REAL_TYPE && code2 != REAL_TYPE)
298 return build_type_attribute_variant (t1, attributes);
299 if (code2 == REAL_TYPE && code1 != REAL_TYPE)
300 return build_type_attribute_variant (t2, attributes);
302 /* Perform the integral promotions. */
303 if (code1 != REAL_TYPE)
305 t1 = type_promotes_to (t1);
306 t2 = type_promotes_to (t2);
309 /* Both real or both integers; use the one with greater precision. */
310 if (TYPE_PRECISION (t1) > TYPE_PRECISION (t2))
311 return build_type_attribute_variant (t1, attributes);
312 else if (TYPE_PRECISION (t2) > TYPE_PRECISION (t1))
313 return build_type_attribute_variant (t2, attributes);
315 /* The types are the same; no need to do anything fancy. */
316 if (TYPE_MAIN_VARIANT (t1) == TYPE_MAIN_VARIANT (t2))
317 return build_type_attribute_variant (t1, attributes);
319 if (code1 != REAL_TYPE)
321 /* If one is a sizetype, use it so size_binop doesn't blow up. */
322 if (TYPE_IS_SIZETYPE (t1) > TYPE_IS_SIZETYPE (t2))
323 return build_type_attribute_variant (t1, attributes);
324 if (TYPE_IS_SIZETYPE (t2) > TYPE_IS_SIZETYPE (t1))
325 return build_type_attribute_variant (t2, attributes);
327 /* If one is unsigned long long, then convert the other to unsigned
329 if (same_type_p (TYPE_MAIN_VARIANT (t1), long_long_unsigned_type_node)
330 || same_type_p (TYPE_MAIN_VARIANT (t2), long_long_unsigned_type_node))
331 return build_type_attribute_variant (long_long_unsigned_type_node,
333 /* If one is a long long, and the other is an unsigned long, and
334 long long can represent all the values of an unsigned long, then
335 convert to a long long. Otherwise, convert to an unsigned long
336 long. Otherwise, if either operand is long long, convert the
339 Since we're here, we know the TYPE_PRECISION is the same;
340 therefore converting to long long cannot represent all the values
341 of an unsigned long, so we choose unsigned long long in that
343 if (same_type_p (TYPE_MAIN_VARIANT (t1), long_long_integer_type_node)
344 || same_type_p (TYPE_MAIN_VARIANT (t2), long_long_integer_type_node))
346 tree t = ((TYPE_UNSIGNED (t1) || TYPE_UNSIGNED (t2))
347 ? long_long_unsigned_type_node
348 : long_long_integer_type_node);
349 return build_type_attribute_variant (t, attributes);
352 /* Go through the same procedure, but for longs. */
353 if (same_type_p (TYPE_MAIN_VARIANT (t1), long_unsigned_type_node)
354 || same_type_p (TYPE_MAIN_VARIANT (t2), long_unsigned_type_node))
355 return build_type_attribute_variant (long_unsigned_type_node,
357 if (same_type_p (TYPE_MAIN_VARIANT (t1), long_integer_type_node)
358 || same_type_p (TYPE_MAIN_VARIANT (t2), long_integer_type_node))
360 tree t = ((TYPE_UNSIGNED (t1) || TYPE_UNSIGNED (t2))
361 ? long_unsigned_type_node : long_integer_type_node);
362 return build_type_attribute_variant (t, attributes);
364 /* Otherwise prefer the unsigned one. */
365 if (TYPE_UNSIGNED (t1))
366 return build_type_attribute_variant (t1, attributes);
368 return build_type_attribute_variant (t2, attributes);
372 if (same_type_p (TYPE_MAIN_VARIANT (t1), long_double_type_node)
373 || same_type_p (TYPE_MAIN_VARIANT (t2), long_double_type_node))
374 return build_type_attribute_variant (long_double_type_node,
376 if (same_type_p (TYPE_MAIN_VARIANT (t1), double_type_node)
377 || same_type_p (TYPE_MAIN_VARIANT (t2), double_type_node))
378 return build_type_attribute_variant (double_type_node,
380 if (same_type_p (TYPE_MAIN_VARIANT (t1), float_type_node)
381 || same_type_p (TYPE_MAIN_VARIANT (t2), float_type_node))
382 return build_type_attribute_variant (float_type_node,
385 /* Two floating-point types whose TYPE_MAIN_VARIANTs are none of
386 the standard C++ floating-point types. Logic earlier in this
387 function has already eliminated the possibility that
388 TYPE_PRECISION (t2) != TYPE_PRECISION (t1), so there's no
389 compelling reason to choose one or the other. */
390 return build_type_attribute_variant (t1, attributes);
394 /* Subroutine of composite_pointer_type to implement the recursive
395 case. See that function for documentation fo the parameters. */
398 composite_pointer_type_r (tree t1, tree t2, const char* location)
405 /* Determine the types pointed to by T1 and T2. */
406 if (TREE_CODE (t1) == POINTER_TYPE)
408 pointee1 = TREE_TYPE (t1);
409 pointee2 = TREE_TYPE (t2);
413 pointee1 = TYPE_PTRMEM_POINTED_TO_TYPE (t1);
414 pointee2 = TYPE_PTRMEM_POINTED_TO_TYPE (t2);
419 Otherwise, the composite pointer type is a pointer type
420 similar (_conv.qual_) to the type of one of the operands,
421 with a cv-qualification signature (_conv.qual_) that is the
422 union of the cv-qualification signatures of the operand
424 if (same_type_ignoring_top_level_qualifiers_p (pointee1, pointee2))
425 result_type = pointee1;
426 else if ((TREE_CODE (pointee1) == POINTER_TYPE
427 && TREE_CODE (pointee2) == POINTER_TYPE)
428 || (TYPE_PTR_TO_MEMBER_P (pointee1)
429 && TYPE_PTR_TO_MEMBER_P (pointee2)))
430 result_type = composite_pointer_type_r (pointee1, pointee2, location);
433 pedwarn ("%s between distinct pointer types `%T' and `%T' "
436 result_type = void_type_node;
438 result_type = cp_build_qualified_type (result_type,
439 (cp_type_quals (pointee1)
440 | cp_type_quals (pointee2)));
441 /* If the original types were pointers to members, so is the
443 if (TYPE_PTR_TO_MEMBER_P (t1))
445 if (!same_type_p (TYPE_PTRMEM_CLASS_TYPE (t1),
446 TYPE_PTRMEM_CLASS_TYPE (t2)))
447 pedwarn ("%s between distinct pointer types `%T' and `%T' "
450 result_type = build_ptrmem_type (TYPE_PTRMEM_CLASS_TYPE (t1),
454 result_type = build_pointer_type (result_type);
456 /* Merge the attributes. */
457 attributes = (*targetm.merge_type_attributes) (t1, t2);
458 return build_type_attribute_variant (result_type, attributes);
461 /* Return the composite pointer type (see [expr.rel]) for T1 and T2.
462 ARG1 and ARG2 are the values with those types. The LOCATION is a
463 string describing the current location, in case an error occurs.
465 This routine also implements the computation of a common type for
466 pointers-to-members as per [expr.eq]. */
469 composite_pointer_type (tree t1, tree t2, tree arg1, tree arg2,
470 const char* location)
477 If one operand is a null pointer constant, the composite pointer
478 type is the type of the other operand. */
479 if (null_ptr_cst_p (arg1))
481 if (null_ptr_cst_p (arg2))
488 If one of the operands has type "pointer to cv1 void*", then
489 the other has type "pointer to cv2T", and the composite pointer
490 type is "pointer to cv12 void", where cv12 is the union of cv1
493 If either type is a pointer to void, make sure it is T1. */
494 if (TREE_CODE (t2) == POINTER_TYPE && VOID_TYPE_P (TREE_TYPE (t2)))
502 /* Now, if T1 is a pointer to void, merge the qualifiers. */
503 if (TREE_CODE (t1) == POINTER_TYPE && VOID_TYPE_P (TREE_TYPE (t1)))
508 if (pedantic && TYPE_PTRFN_P (t2))
509 pedwarn ("ISO C++ forbids %s between pointer of type `void *' and pointer-to-function", location);
511 = cp_build_qualified_type (void_type_node,
512 (cp_type_quals (TREE_TYPE (t1))
513 | cp_type_quals (TREE_TYPE (t2))));
514 result_type = build_pointer_type (result_type);
515 /* Merge the attributes. */
516 attributes = (*targetm.merge_type_attributes) (t1, t2);
517 return build_type_attribute_variant (result_type, attributes);
520 /* [expr.eq] permits the application of a pointer conversion to
521 bring the pointers to a common type. */
522 if (TREE_CODE (t1) == POINTER_TYPE && TREE_CODE (t2) == POINTER_TYPE
523 && CLASS_TYPE_P (TREE_TYPE (t1))
524 && CLASS_TYPE_P (TREE_TYPE (t2))
525 && !same_type_ignoring_top_level_qualifiers_p (TREE_TYPE (t1),
528 class1 = TREE_TYPE (t1);
529 class2 = TREE_TYPE (t2);
531 if (DERIVED_FROM_P (class1, class2))
532 t2 = (build_pointer_type
533 (cp_build_qualified_type (class1, TYPE_QUALS (class2))));
534 else if (DERIVED_FROM_P (class2, class1))
535 t1 = (build_pointer_type
536 (cp_build_qualified_type (class2, TYPE_QUALS (class1))));
539 error ("%s between distinct pointer types `%T' and `%T' "
540 "lacks a cast", location, t1, t2);
541 return error_mark_node;
544 /* [expr.eq] permits the application of a pointer-to-member
545 conversion to change the class type of one of the types. */
546 else if (TYPE_PTR_TO_MEMBER_P (t1)
547 && !same_type_p (TYPE_PTRMEM_CLASS_TYPE (t1),
548 TYPE_PTRMEM_CLASS_TYPE (t2)))
550 class1 = TYPE_PTRMEM_CLASS_TYPE (t1);
551 class2 = TYPE_PTRMEM_CLASS_TYPE (t2);
553 if (DERIVED_FROM_P (class1, class2))
554 t1 = build_ptrmem_type (class2, TYPE_PTRMEM_POINTED_TO_TYPE (t1));
555 else if (DERIVED_FROM_P (class2, class1))
556 t2 = build_ptrmem_type (class1, TYPE_PTRMEM_POINTED_TO_TYPE (t2));
559 error ("%s between distinct pointer-to-member types `%T' and `%T' "
560 "lacks a cast", location, t1, t2);
561 return error_mark_node;
565 return composite_pointer_type_r (t1, t2, location);
568 /* Return the merged type of two types.
569 We assume that comptypes has already been done and returned 1;
570 if that isn't so, this may crash.
572 This just combines attributes and default arguments; any other
573 differences would cause the two types to compare unalike. */
576 merge_types (tree t1, tree t2)
578 enum tree_code code1;
579 enum tree_code code2;
582 /* Save time if the two types are the same. */
585 if (original_type (t1) == original_type (t2))
588 /* If one type is nonsense, use the other. */
589 if (t1 == error_mark_node)
591 if (t2 == error_mark_node)
594 /* Merge the attributes. */
595 attributes = (*targetm.merge_type_attributes) (t1, t2);
597 if (TYPE_PTRMEMFUNC_P (t1))
598 t1 = TYPE_PTRMEMFUNC_FN_TYPE (t1);
599 if (TYPE_PTRMEMFUNC_P (t2))
600 t2 = TYPE_PTRMEMFUNC_FN_TYPE (t2);
602 code1 = TREE_CODE (t1);
603 code2 = TREE_CODE (t2);
609 /* For two pointers, do this recursively on the target type. */
611 tree target = merge_types (TREE_TYPE (t1), TREE_TYPE (t2));
612 int quals = cp_type_quals (t1);
614 if (code1 == POINTER_TYPE)
615 t1 = build_pointer_type (target);
617 t1 = build_reference_type (target);
618 t1 = build_type_attribute_variant (t1, attributes);
619 t1 = cp_build_qualified_type (t1, quals);
621 if (TREE_CODE (target) == METHOD_TYPE)
622 t1 = build_ptrmemfunc_type (t1);
631 quals = cp_type_quals (t1);
632 pointee = merge_types (TYPE_PTRMEM_POINTED_TO_TYPE (t1),
633 TYPE_PTRMEM_POINTED_TO_TYPE (t2));
634 t1 = build_ptrmem_type (TYPE_PTRMEM_CLASS_TYPE (t1),
636 t1 = cp_build_qualified_type (t1, quals);
642 tree elt = merge_types (TREE_TYPE (t1), TREE_TYPE (t2));
643 /* Save space: see if the result is identical to one of the args. */
644 if (elt == TREE_TYPE (t1) && TYPE_DOMAIN (t1))
645 return build_type_attribute_variant (t1, attributes);
646 if (elt == TREE_TYPE (t2) && TYPE_DOMAIN (t2))
647 return build_type_attribute_variant (t2, attributes);
648 /* Merge the element types, and have a size if either arg has one. */
649 t1 = build_cplus_array_type
650 (elt, TYPE_DOMAIN (TYPE_DOMAIN (t1) ? t1 : t2));
655 /* Function types: prefer the one that specified arg types.
656 If both do, merge the arg types. Also merge the return types. */
658 tree valtype = merge_types (TREE_TYPE (t1), TREE_TYPE (t2));
659 tree p1 = TYPE_ARG_TYPES (t1);
660 tree p2 = TYPE_ARG_TYPES (t2);
663 /* Save space: see if the result is identical to one of the args. */
664 if (valtype == TREE_TYPE (t1) && ! p2)
665 return cp_build_type_attribute_variant (t1, attributes);
666 if (valtype == TREE_TYPE (t2) && ! p1)
667 return cp_build_type_attribute_variant (t2, attributes);
669 /* Simple way if one arg fails to specify argument types. */
670 if (p1 == NULL_TREE || TREE_VALUE (p1) == void_type_node)
672 rval = build_function_type (valtype, p2);
673 if ((raises = TYPE_RAISES_EXCEPTIONS (t2)))
674 rval = build_exception_variant (rval, raises);
675 return cp_build_type_attribute_variant (rval, attributes);
677 raises = TYPE_RAISES_EXCEPTIONS (t1);
678 if (p2 == NULL_TREE || TREE_VALUE (p2) == void_type_node)
680 rval = build_function_type (valtype, p1);
682 rval = build_exception_variant (rval, raises);
683 return cp_build_type_attribute_variant (rval, attributes);
686 rval = build_function_type (valtype, commonparms (p1, p2));
687 t1 = build_exception_variant (rval, raises);
693 /* Get this value the long way, since TYPE_METHOD_BASETYPE
694 is just the main variant of this. */
695 tree basetype = TREE_TYPE (TREE_VALUE (TYPE_ARG_TYPES (t2)));
696 tree raises = TYPE_RAISES_EXCEPTIONS (t1);
699 /* If this was a member function type, get back to the
700 original type of type member function (i.e., without
701 the class instance variable up front. */
702 t1 = build_function_type (TREE_TYPE (t1),
703 TREE_CHAIN (TYPE_ARG_TYPES (t1)));
704 t2 = build_function_type (TREE_TYPE (t2),
705 TREE_CHAIN (TYPE_ARG_TYPES (t2)));
706 t3 = merge_types (t1, t2);
707 t3 = build_method_type_directly (basetype, TREE_TYPE (t3),
708 TYPE_ARG_TYPES (t3));
709 t1 = build_exception_variant (t3, raises);
714 /* There is no need to merge attributes into a TYPENAME_TYPE.
715 When the type is instantiated it will have whatever
716 attributes result from the instantiation. */
721 return cp_build_type_attribute_variant (t1, attributes);
724 /* Return the common type of two types.
725 We assume that comptypes has already been done and returned 1;
726 if that isn't so, this may crash.
728 This is the type for the result of most arithmetic operations
729 if the operands have the given two types. */
732 common_type (tree t1, tree t2)
734 enum tree_code code1;
735 enum tree_code code2;
737 /* If one type is nonsense, bail. */
738 if (t1 == error_mark_node || t2 == error_mark_node)
739 return error_mark_node;
741 code1 = TREE_CODE (t1);
742 code2 = TREE_CODE (t2);
744 if ((ARITHMETIC_TYPE_P (t1) || code1 == ENUMERAL_TYPE
745 || code1 == COMPLEX_TYPE)
746 && (ARITHMETIC_TYPE_P (t2) || code2 == ENUMERAL_TYPE
747 || code2 == COMPLEX_TYPE))
748 return type_after_usual_arithmetic_conversions (t1, t2);
750 else if ((TYPE_PTR_P (t1) && TYPE_PTR_P (t2))
751 || (TYPE_PTRMEM_P (t1) && TYPE_PTRMEM_P (t2))
752 || (TYPE_PTRMEMFUNC_P (t1) && TYPE_PTRMEMFUNC_P (t2)))
753 return composite_pointer_type (t1, t2, error_mark_node, error_mark_node,
759 /* Compare two exception specifier types for exactness or subsetness, if
760 allowed. Returns false for mismatch, true for match (same, or
763 [except.spec] "If a class X ... objects of class X or any class publicly
764 and unambiguously derived from X. Similarly, if a pointer type Y * ...
765 exceptions of type Y * or that are pointers to any type publicly and
766 unambiguously derived from Y. Otherwise a function only allows exceptions
767 that have the same type ..."
768 This does not mention cv qualifiers and is different to what throw
769 [except.throw] and catch [except.catch] will do. They will ignore the
770 top level cv qualifiers, and allow qualifiers in the pointer to class
773 We implement the letter of the standard. */
776 comp_except_types (tree a, tree b, bool exact)
778 if (same_type_p (a, b))
782 if (cp_type_quals (a) || cp_type_quals (b))
785 if (TREE_CODE (a) == POINTER_TYPE
786 && TREE_CODE (b) == POINTER_TYPE)
790 if (cp_type_quals (a) || cp_type_quals (b))
794 if (TREE_CODE (a) != RECORD_TYPE
795 || TREE_CODE (b) != RECORD_TYPE)
798 if (ACCESSIBLY_UNIQUELY_DERIVED_P (a, b))
804 /* Return true if TYPE1 and TYPE2 are equivalent exception specifiers.
805 If EXACT is false, T2 can be stricter than T1 (according to 15.4/7),
806 otherwise it must be exact. Exception lists are unordered, but
807 we've already filtered out duplicates. Most lists will be in order,
808 we should try to make use of that. */
811 comp_except_specs (tree t1, tree t2, bool exact)
820 if (t1 == NULL_TREE) /* T1 is ... */
821 return t2 == NULL_TREE || !exact;
822 if (!TREE_VALUE (t1)) /* t1 is EMPTY */
823 return t2 != NULL_TREE && !TREE_VALUE (t2);
824 if (t2 == NULL_TREE) /* T2 is ... */
826 if (TREE_VALUE (t1) && !TREE_VALUE (t2)) /* T2 is EMPTY, T1 is not */
829 /* Neither set is ... or EMPTY, make sure each part of T2 is in T1.
830 Count how many we find, to determine exactness. For exact matching and
831 ordered T1, T2, this is an O(n) operation, otherwise its worst case is
833 for (base = t1; t2 != NULL_TREE; t2 = TREE_CHAIN (t2))
835 for (probe = base; probe != NULL_TREE; probe = TREE_CHAIN (probe))
837 tree a = TREE_VALUE (probe);
838 tree b = TREE_VALUE (t2);
840 if (comp_except_types (a, b, exact))
842 if (probe == base && exact)
843 base = TREE_CHAIN (probe);
848 if (probe == NULL_TREE)
851 return !exact || base == NULL_TREE || length == list_length (t1);
854 /* Compare the array types T1 and T2. ALLOW_REDECLARATION is true if
855 [] can match [size]. */
858 comp_array_types (tree t1, tree t2, bool allow_redeclaration)
867 /* The type of the array elements must be the same. */
868 if (!same_type_p (TREE_TYPE (t1), TREE_TYPE (t2)))
871 d1 = TYPE_DOMAIN (t1);
872 d2 = TYPE_DOMAIN (t2);
877 /* If one of the arrays is dimensionless, and the other has a
878 dimension, they are of different types. However, it is valid to
886 declarations for an array object can specify
887 array types that differ by the presence or absence of a major
888 array bound (_dcl.array_). */
890 return allow_redeclaration;
892 /* Check that the dimensions are the same. */
894 if (!cp_tree_equal (TYPE_MIN_VALUE (d1), TYPE_MIN_VALUE (d2)))
896 max1 = TYPE_MAX_VALUE (d1);
897 max2 = TYPE_MAX_VALUE (d2);
898 if (processing_template_decl && !abi_version_at_least (2)
899 && !value_dependent_expression_p (max1)
900 && !value_dependent_expression_p (max2))
902 /* With abi-1 we do not fold non-dependent array bounds, (and
903 consequently mangle them incorrectly). We must therefore
904 fold them here, to verify the domains have the same
910 if (!cp_tree_equal (max1, max2))
916 /* Return true if T1 and T2 are related as allowed by STRICT. STRICT
917 is a bitwise-or of the COMPARE_* flags. */
920 comptypes (tree t1, tree t2, int strict)
925 /* Suppress errors caused by previously reported errors. */
926 if (t1 == error_mark_node || t2 == error_mark_node)
929 gcc_assert (TYPE_P (t1) && TYPE_P (t2));
931 /* TYPENAME_TYPEs should be resolved if the qualifying scope is the
932 current instantiation. */
933 if (TREE_CODE (t1) == TYPENAME_TYPE)
935 tree resolved = resolve_typename_type (t1, /*only_current_p=*/true);
937 if (resolved != error_mark_node)
941 if (TREE_CODE (t2) == TYPENAME_TYPE)
943 tree resolved = resolve_typename_type (t2, /*only_current_p=*/true);
945 if (resolved != error_mark_node)
949 /* If either type is the internal version of sizetype, use the
951 if (TREE_CODE (t1) == INTEGER_TYPE && TYPE_IS_SIZETYPE (t1)
952 && TYPE_ORIG_SIZE_TYPE (t1))
953 t1 = TYPE_ORIG_SIZE_TYPE (t1);
955 if (TREE_CODE (t2) == INTEGER_TYPE && TYPE_IS_SIZETYPE (t2)
956 && TYPE_ORIG_SIZE_TYPE (t2))
957 t2 = TYPE_ORIG_SIZE_TYPE (t2);
959 if (TYPE_PTRMEMFUNC_P (t1))
960 t1 = TYPE_PTRMEMFUNC_FN_TYPE (t1);
961 if (TYPE_PTRMEMFUNC_P (t2))
962 t2 = TYPE_PTRMEMFUNC_FN_TYPE (t2);
964 /* Different classes of types can't be compatible. */
965 if (TREE_CODE (t1) != TREE_CODE (t2))
968 /* Qualifiers must match. For array types, we will check when we
969 recur on the array element types. */
970 if (TREE_CODE (t1) != ARRAY_TYPE
971 && TYPE_QUALS (t1) != TYPE_QUALS (t2))
973 if (TYPE_FOR_JAVA (t1) != TYPE_FOR_JAVA (t2))
976 /* Allow for two different type nodes which have essentially the same
977 definition. Note that we already checked for equality of the type
978 qualifiers (just above). */
980 if (TREE_CODE (t1) != ARRAY_TYPE
981 && TYPE_MAIN_VARIANT (t1) == TYPE_MAIN_VARIANT (t2))
984 if (!(*targetm.comp_type_attributes) (t1, t2))
987 switch (TREE_CODE (t1))
989 case TEMPLATE_TEMPLATE_PARM:
990 case BOUND_TEMPLATE_TEMPLATE_PARM:
991 if (TEMPLATE_TYPE_IDX (t1) != TEMPLATE_TYPE_IDX (t2)
992 || TEMPLATE_TYPE_LEVEL (t1) != TEMPLATE_TYPE_LEVEL (t2))
994 if (!comp_template_parms
995 (DECL_TEMPLATE_PARMS (TEMPLATE_TEMPLATE_PARM_TEMPLATE_DECL (t1)),
996 DECL_TEMPLATE_PARMS (TEMPLATE_TEMPLATE_PARM_TEMPLATE_DECL (t2))))
998 if (TREE_CODE (t1) == TEMPLATE_TEMPLATE_PARM)
1000 /* Don't check inheritance. */
1001 strict = COMPARE_STRICT;
1006 if (TYPE_TEMPLATE_INFO (t1) && TYPE_TEMPLATE_INFO (t2)
1007 && (TYPE_TI_TEMPLATE (t1) == TYPE_TI_TEMPLATE (t2)
1008 || TREE_CODE (t1) == BOUND_TEMPLATE_TEMPLATE_PARM)
1009 && comp_template_args (TYPE_TI_ARGS (t1), TYPE_TI_ARGS (t2)))
1012 if ((strict & COMPARE_BASE) && DERIVED_FROM_P (t1, t2))
1014 else if ((strict & COMPARE_DERIVED) && DERIVED_FROM_P (t2, t1))
1020 if (!comptypes (TYPE_OFFSET_BASETYPE (t1), TYPE_OFFSET_BASETYPE (t2),
1021 strict & ~COMPARE_REDECLARATION))
1026 case REFERENCE_TYPE:
1027 return same_type_p (TREE_TYPE (t1), TREE_TYPE (t2));
1031 if (!same_type_p (TREE_TYPE (t1), TREE_TYPE (t2)))
1033 return compparms (TYPE_ARG_TYPES (t1), TYPE_ARG_TYPES (t2));
1036 /* Target types must match incl. qualifiers. */
1037 return comp_array_types (t1, t2, !!(strict & COMPARE_REDECLARATION));
1039 case TEMPLATE_TYPE_PARM:
1040 return (TEMPLATE_TYPE_IDX (t1) == TEMPLATE_TYPE_IDX (t2)
1041 && TEMPLATE_TYPE_LEVEL (t1) == TEMPLATE_TYPE_LEVEL (t2));
1044 if (!cp_tree_equal (TYPENAME_TYPE_FULLNAME (t1),
1045 TYPENAME_TYPE_FULLNAME (t2)))
1047 return same_type_p (TYPE_CONTEXT (t1), TYPE_CONTEXT (t2));
1049 case UNBOUND_CLASS_TEMPLATE:
1050 if (!cp_tree_equal (TYPE_IDENTIFIER (t1), TYPE_IDENTIFIER (t2)))
1052 return same_type_p (TYPE_CONTEXT (t1), TYPE_CONTEXT (t2));
1055 return same_type_p (TREE_TYPE (t1), TREE_TYPE (t2));
1058 return TYPE_VECTOR_SUBPARTS (t1) == TYPE_VECTOR_SUBPARTS (t2)
1059 && same_type_p (TREE_TYPE (t1), TREE_TYPE (t2));
1068 /* Returns 1 if TYPE1 is at least as qualified as TYPE2. */
1071 at_least_as_qualified_p (tree type1, tree type2)
1073 int q1 = cp_type_quals (type1);
1074 int q2 = cp_type_quals (type2);
1076 /* All qualifiers for TYPE2 must also appear in TYPE1. */
1077 return (q1 & q2) == q2;
1080 /* Returns 1 if TYPE1 is more qualified than TYPE2. */
1083 more_qualified_p (tree type1, tree type2)
1085 int q1 = cp_type_quals (type1);
1086 int q2 = cp_type_quals (type2);
1088 return q1 != q2 && (q1 & q2) == q2;
1091 /* Returns 1 if TYPE1 is more cv-qualified than TYPE2, -1 if TYPE2 is
1092 more cv-qualified that TYPE1, and 0 otherwise. */
1095 comp_cv_qualification (tree type1, tree type2)
1097 int q1 = cp_type_quals (type1);
1098 int q2 = cp_type_quals (type2);
1103 if ((q1 & q2) == q2)
1105 else if ((q1 & q2) == q1)
1111 /* Returns 1 if the cv-qualification signature of TYPE1 is a proper
1112 subset of the cv-qualification signature of TYPE2, and the types
1113 are similar. Returns -1 if the other way 'round, and 0 otherwise. */
1116 comp_cv_qual_signature (tree type1, tree type2)
1118 if (comp_ptr_ttypes_real (type2, type1, -1))
1120 else if (comp_ptr_ttypes_real (type1, type2, -1))
1126 /* If two types share a common base type, return that basetype.
1127 If there is not a unique most-derived base type, this function
1128 returns ERROR_MARK_NODE. */
1131 common_base_type (tree tt1, tree tt2)
1133 tree best = NULL_TREE;
1136 /* If one is a baseclass of another, that's good enough. */
1137 if (UNIQUELY_DERIVED_FROM_P (tt1, tt2))
1139 if (UNIQUELY_DERIVED_FROM_P (tt2, tt1))
1142 /* Otherwise, try to find a unique baseclass of TT1
1143 that is shared by TT2, and follow that down. */
1144 for (i = BINFO_N_BASE_BINFOS (TYPE_BINFO (tt1))-1; i >= 0; i--)
1146 tree basetype = BINFO_TYPE (BINFO_BASE_BINFO (TYPE_BINFO (tt1), i));
1147 tree trial = common_base_type (basetype, tt2);
1151 if (trial == error_mark_node)
1153 if (best == NULL_TREE)
1155 else if (best != trial)
1156 return error_mark_node;
1161 for (i = BINFO_N_BASE_BINFOS (TYPE_BINFO (tt2))-1; i >= 0; i--)
1163 tree basetype = BINFO_TYPE (BINFO_BASE_BINFO (TYPE_BINFO (tt2), i));
1164 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 gcc_assert (op == SIZEOF_EXPR || op == ALIGNOF_EXPR);
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 build2 (COMPOUND_EXPR, TREE_TYPE (op1),
1387 TREE_OPERAND (exp, 0), op1);
1391 && ! (TREE_CODE (exp) == CONSTRUCTOR && TREE_STATIC (exp)))
1393 error ("invalid use of non-lvalue array");
1394 return error_mark_node;
1397 ptrtype = build_pointer_type (TREE_TYPE (type));
1399 if (TREE_CODE (exp) == VAR_DECL)
1401 if (!cxx_mark_addressable (exp))
1402 return error_mark_node;
1403 adr = build_nop (ptrtype, build_address (exp));
1406 /* This way is better for a COMPONENT_REF since it can
1407 simplify the offset for a component. */
1408 adr = build_unary_op (ADDR_EXPR, exp, 1);
1409 return cp_convert (ptrtype, adr);
1412 /* [basic.lval]: Class rvalues can have cv-qualified types; non-class
1413 rvalues always have cv-unqualified types. */
1414 if (! CLASS_TYPE_P (type))
1415 exp = cp_convert (TYPE_MAIN_VARIANT (type), exp);
1421 default_conversion (tree exp)
1423 exp = decay_conversion (exp);
1425 if (INTEGRAL_OR_ENUMERATION_TYPE_P (TREE_TYPE (exp)))
1426 exp = perform_integral_promotions (exp);
1431 /* EXPR is an expression with an integral or enumeration type.
1432 Perform the integral promotions in [conv.prom], and return the
1436 perform_integral_promotions (tree expr)
1441 type = TREE_TYPE (expr);
1442 gcc_assert (INTEGRAL_OR_ENUMERATION_TYPE_P (type));
1443 promoted_type = type_promotes_to (type);
1444 if (type != promoted_type)
1445 expr = cp_convert (promoted_type, expr);
1449 /* Take the address of an inline function without setting TREE_ADDRESSABLE
1453 inline_conversion (tree exp)
1455 if (TREE_CODE (exp) == FUNCTION_DECL)
1456 exp = build1 (ADDR_EXPR, build_pointer_type (TREE_TYPE (exp)), exp);
1461 /* Returns nonzero iff exp is a STRING_CST or the result of applying
1462 decay_conversion to one. */
1465 string_conv_p (tree totype, tree exp, int warn)
1469 if (! flag_const_strings || TREE_CODE (totype) != POINTER_TYPE)
1472 t = TREE_TYPE (totype);
1473 if (!same_type_p (t, char_type_node)
1474 && !same_type_p (t, wchar_type_node))
1477 if (TREE_CODE (exp) == STRING_CST)
1479 /* Make sure that we don't try to convert between char and wchar_t. */
1480 if (!same_type_p (TYPE_MAIN_VARIANT (TREE_TYPE (TREE_TYPE (exp))), t))
1485 /* Is this a string constant which has decayed to 'const char *'? */
1486 t = build_pointer_type (build_qualified_type (t, TYPE_QUAL_CONST));
1487 if (!same_type_p (TREE_TYPE (exp), t))
1490 if (TREE_CODE (exp) != ADDR_EXPR
1491 || TREE_CODE (TREE_OPERAND (exp, 0)) != STRING_CST)
1495 /* This warning is not very useful, as it complains about printf. */
1496 if (warn && warn_write_strings)
1497 warning ("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 gcc_assert (DECL_P (member) || BASELINK_P (member));
1600 The type of the first expression shall be "class object" (of a
1602 object_type = TREE_TYPE (object);
1603 if (!currently_open_class (object_type)
1604 && !complete_type_or_else (object_type, object))
1605 return error_mark_node;
1606 if (!CLASS_TYPE_P (object_type))
1608 error ("request for member `%D' in `%E', which is of non-class type `%T'",
1609 member, object, object_type);
1610 return error_mark_node;
1613 /* The standard does not seem to actually say that MEMBER must be a
1614 member of OBJECT_TYPE. However, that is clearly what is
1616 if (DECL_P (member))
1618 member_scope = DECL_CLASS_CONTEXT (member);
1620 if (TREE_DEPRECATED (member))
1621 warn_deprecated_use (member);
1624 member_scope = BINFO_TYPE (BASELINK_BINFO (member));
1625 /* If MEMBER is from an anonymous aggregate, MEMBER_SCOPE will
1626 presently be the anonymous union. Go outwards until we find a
1627 type related to OBJECT_TYPE. */
1628 while (ANON_AGGR_TYPE_P (member_scope)
1629 && !same_type_ignoring_top_level_qualifiers_p (member_scope,
1631 member_scope = TYPE_CONTEXT (member_scope);
1632 if (!member_scope || !DERIVED_FROM_P (member_scope, object_type))
1634 if (TREE_CODE (member) == FIELD_DECL)
1635 error ("invalid use of nonstatic data member '%E'", member);
1637 error ("`%D' is not a member of `%T'", member, object_type);
1638 return error_mark_node;
1641 /* Transform `(a, b).x' into `(*(a, &b)).x', `(a ? b : c).x' into
1642 `(*(a ? &b : &c)).x', and so on. A COND_EXPR is only an lvalue
1643 in the frontend; only _DECLs and _REFs are lvalues in the backend. */
1645 tree temp = unary_complex_lvalue (ADDR_EXPR, object);
1647 object = build_indirect_ref (temp, NULL);
1650 /* In [expr.ref], there is an explicit list of the valid choices for
1651 MEMBER. We check for each of those cases here. */
1652 if (TREE_CODE (member) == VAR_DECL)
1654 /* A static data member. */
1656 /* If OBJECT has side-effects, they are supposed to occur. */
1657 if (TREE_SIDE_EFFECTS (object))
1658 result = build2 (COMPOUND_EXPR, TREE_TYPE (result), object, result);
1660 else if (TREE_CODE (member) == FIELD_DECL)
1662 /* A non-static data member. */
1667 null_object_p = (TREE_CODE (object) == INDIRECT_REF
1668 && integer_zerop (TREE_OPERAND (object, 0)));
1670 /* Convert OBJECT to the type of MEMBER. */
1671 if (!same_type_p (TYPE_MAIN_VARIANT (object_type),
1672 TYPE_MAIN_VARIANT (member_scope)))
1677 binfo = lookup_base (access_path ? access_path : object_type,
1678 member_scope, ba_ignore, &kind);
1679 if (binfo == error_mark_node)
1680 return error_mark_node;
1682 /* It is invalid to try to get to a virtual base of a
1683 NULL object. The most common cause is invalid use of
1685 if (null_object_p && kind == bk_via_virtual)
1687 error ("invalid access to non-static data member `%D' of NULL object",
1689 error ("(perhaps the `offsetof' macro was used incorrectly)");
1690 return error_mark_node;
1693 /* Convert to the base. */
1694 object = build_base_path (PLUS_EXPR, object, binfo,
1696 /* If we found the base successfully then we should be able
1697 to convert to it successfully. */
1698 gcc_assert (object != error_mark_node);
1701 /* Complain about other invalid uses of offsetof, even though they will
1702 give the right answer. Note that we complain whether or not they
1703 actually used the offsetof macro, since there's no way to know at this
1704 point. So we just give a warning, instead of a pedwarn. */
1705 if (null_object_p && warn_invalid_offsetof
1706 && CLASSTYPE_NON_POD_P (object_type)
1707 && ! skip_evaluation)
1709 warning ("invalid access to non-static data member `%D' of NULL object",
1711 warning ("(perhaps the `offsetof' macro was used incorrectly)");
1714 /* If MEMBER is from an anonymous aggregate, we have converted
1715 OBJECT so that it refers to the class containing the
1716 anonymous union. Generate a reference to the anonymous union
1717 itself, and recur to find MEMBER. */
1718 if (ANON_AGGR_TYPE_P (DECL_CONTEXT (member))
1719 /* When this code is called from build_field_call, the
1720 object already has the type of the anonymous union.
1721 That is because the COMPONENT_REF was already
1722 constructed, and was then disassembled before calling
1723 build_field_call. After the function-call code is
1724 cleaned up, this waste can be eliminated. */
1725 && (!same_type_ignoring_top_level_qualifiers_p
1726 (TREE_TYPE (object), DECL_CONTEXT (member))))
1728 tree anonymous_union;
1730 anonymous_union = lookup_anon_field (TREE_TYPE (object),
1731 DECL_CONTEXT (member));
1732 object = build_class_member_access_expr (object,
1734 /*access_path=*/NULL_TREE,
1735 preserve_reference);
1738 /* Compute the type of the field, as described in [expr.ref]. */
1739 type_quals = TYPE_UNQUALIFIED;
1740 member_type = TREE_TYPE (member);
1741 if (TREE_CODE (member_type) != REFERENCE_TYPE)
1743 type_quals = (cp_type_quals (member_type)
1744 | cp_type_quals (object_type));
1746 /* A field is const (volatile) if the enclosing object, or the
1747 field itself, is const (volatile). But, a mutable field is
1748 not const, even within a const object. */
1749 if (DECL_MUTABLE_P (member))
1750 type_quals &= ~TYPE_QUAL_CONST;
1751 member_type = cp_build_qualified_type (member_type, type_quals);
1754 result = fold (build3 (COMPONENT_REF, member_type, object, member,
1757 /* Mark the expression const or volatile, as appropriate. Even
1758 though we've dealt with the type above, we still have to mark the
1759 expression itself. */
1760 if (type_quals & TYPE_QUAL_CONST)
1761 TREE_READONLY (result) = 1;
1762 else if (type_quals & TYPE_QUAL_VOLATILE)
1763 TREE_THIS_VOLATILE (result) = 1;
1765 else if (BASELINK_P (member))
1767 /* The member is a (possibly overloaded) member function. */
1771 /* If the MEMBER is exactly one static member function, then we
1772 know the type of the expression. Otherwise, we must wait
1773 until overload resolution has been performed. */
1774 functions = BASELINK_FUNCTIONS (member);
1775 if (TREE_CODE (functions) == FUNCTION_DECL
1776 && DECL_STATIC_FUNCTION_P (functions))
1777 type = TREE_TYPE (functions);
1779 type = unknown_type_node;
1780 /* Note that we do not convert OBJECT to the BASELINK_BINFO
1781 base. That will happen when the function is called. */
1782 result = build3 (COMPONENT_REF, type, object, member, NULL_TREE);
1784 else if (TREE_CODE (member) == CONST_DECL)
1786 /* The member is an enumerator. */
1788 /* If OBJECT has side-effects, they are supposed to occur. */
1789 if (TREE_SIDE_EFFECTS (object))
1790 result = build2 (COMPOUND_EXPR, TREE_TYPE (result),
1795 error ("invalid use of `%D'", member);
1796 return error_mark_node;
1799 if (!preserve_reference)
1802 If E2 is declared to have type "reference to T", then ... the
1803 type of E1.E2 is T. */
1804 result = convert_from_reference (result);
1809 /* Return the destructor denoted by OBJECT.SCOPE::~DTOR_NAME, or, if
1810 SCOPE is NULL, by OBJECT.~DTOR_NAME. */
1813 lookup_destructor (tree object, tree scope, tree dtor_name)
1815 tree object_type = TREE_TYPE (object);
1816 tree dtor_type = TREE_OPERAND (dtor_name, 0);
1819 if (scope && !check_dtor_name (scope, dtor_name))
1821 error ("qualified type `%T' does not match destructor name `~%T'",
1823 return error_mark_node;
1825 if (!DERIVED_FROM_P (dtor_type, TYPE_MAIN_VARIANT (object_type)))
1827 error ("the type being destroyed is `%T', but the destructor refers to `%T'",
1828 TYPE_MAIN_VARIANT (object_type), dtor_type);
1829 return error_mark_node;
1831 if (!TYPE_HAS_DESTRUCTOR (dtor_type))
1832 return build3 (PSEUDO_DTOR_EXPR, void_type_node, object, scope,
1834 expr = lookup_member (dtor_type, complete_dtor_identifier,
1835 /*protect=*/1, /*want_type=*/false);
1836 expr = (adjust_result_of_qualified_name_lookup
1837 (expr, dtor_type, object_type));
1841 /* This function is called by the parser to process a class member
1842 access expression of the form OBJECT.NAME. NAME is a node used by
1843 the parser to represent a name; it is not yet a DECL. It may,
1844 however, be a BASELINK where the BASELINK_FUNCTIONS is a
1845 TEMPLATE_ID_EXPR. Templates must be looked up by the parser, and
1846 there is no reason to do the lookup twice, so the parser keeps the
1850 finish_class_member_access_expr (tree object, tree name)
1855 tree access_path = NULL_TREE;
1856 tree orig_object = object;
1857 tree orig_name = name;
1859 if (object == error_mark_node || name == error_mark_node)
1860 return error_mark_node;
1862 object_type = TREE_TYPE (object);
1864 if (processing_template_decl)
1866 if (/* If OBJECT_TYPE is dependent, so is OBJECT.NAME. */
1867 dependent_type_p (object_type)
1868 /* If NAME is just an IDENTIFIER_NODE, then the expression
1870 || TREE_CODE (object) == IDENTIFIER_NODE
1871 /* If NAME is "f<args>", where either 'f' or 'args' is
1872 dependent, then the expression is dependent. */
1873 || (TREE_CODE (name) == TEMPLATE_ID_EXPR
1874 && dependent_template_id_p (TREE_OPERAND (name, 0),
1875 TREE_OPERAND (name, 1)))
1876 /* If NAME is "T::X" where "T" is dependent, then the
1877 expression is dependent. */
1878 || (TREE_CODE (name) == SCOPE_REF
1879 && TYPE_P (TREE_OPERAND (name, 0))
1880 && dependent_type_p (TREE_OPERAND (name, 0))))
1881 return build_min_nt (COMPONENT_REF, object, name, NULL_TREE);
1882 object = build_non_dependent_expr (object);
1885 if (TREE_CODE (object_type) == REFERENCE_TYPE)
1887 object = convert_from_reference (object);
1888 object_type = TREE_TYPE (object);
1893 The type of the first expression shall be "class object" (of a
1895 if (!currently_open_class (object_type)
1896 && !complete_type_or_else (object_type, object))
1897 return error_mark_node;
1898 if (!CLASS_TYPE_P (object_type))
1900 error ("request for member `%D' in `%E', which is of non-class type `%T'",
1901 name, object, object_type);
1902 return error_mark_node;
1905 if (BASELINK_P (name))
1907 /* A member function that has already been looked up. */
1908 gcc_assert (TREE_CODE (BASELINK_FUNCTIONS (name)) == TEMPLATE_ID_EXPR);
1913 bool is_template_id = false;
1914 tree template_args = NULL_TREE;
1917 if (TREE_CODE (name) == TEMPLATE_ID_EXPR)
1919 is_template_id = true;
1920 template_args = TREE_OPERAND (name, 1);
1921 name = TREE_OPERAND (name, 0);
1923 if (TREE_CODE (name) == OVERLOAD)
1924 name = DECL_NAME (get_first_fn (name));
1925 else if (DECL_P (name))
1926 name = DECL_NAME (name);
1929 if (TREE_CODE (name) == SCOPE_REF)
1931 /* A qualified name. The qualifying class or namespace `S' has
1932 already been looked up; it is either a TYPE or a
1933 NAMESPACE_DECL. The member name is either an IDENTIFIER_NODE
1934 or a BIT_NOT_EXPR. */
1935 scope = TREE_OPERAND (name, 0);
1936 name = TREE_OPERAND (name, 1);
1937 gcc_assert (CLASS_TYPE_P (scope)
1938 || TREE_CODE (scope) == NAMESPACE_DECL);
1939 gcc_assert (TREE_CODE (name) == IDENTIFIER_NODE
1940 || TREE_CODE (name) == BIT_NOT_EXPR);
1942 /* If SCOPE is a namespace, then the qualified name does not
1943 name a member of OBJECT_TYPE. */
1944 if (TREE_CODE (scope) == NAMESPACE_DECL)
1946 error ("`%D::%D' is not a member of `%T'",
1947 scope, name, object_type);
1948 return error_mark_node;
1951 /* Find the base of OBJECT_TYPE corresponding to SCOPE. */
1952 access_path = lookup_base (object_type, scope, ba_check, NULL);
1953 if (access_path == error_mark_node)
1954 return error_mark_node;
1957 error ("`%T' is not a base of `%T'", scope, object_type);
1958 return error_mark_node;
1964 access_path = object_type;
1967 if (TREE_CODE (name) == BIT_NOT_EXPR)
1968 member = lookup_destructor (object, scope, name);
1971 /* Look up the member. */
1972 member = lookup_member (access_path, name, /*protect=*/1,
1973 /*want_type=*/false);
1974 if (member == NULL_TREE)
1976 error ("'%D' has no member named '%E'", object_type, name);
1977 return error_mark_node;
1979 if (member == error_mark_node)
1980 return error_mark_node;
1985 tree template = member;
1987 if (BASELINK_P (template))
1988 template = lookup_template_function (template, template_args);
1991 error ("`%D' is not a member template function", name);
1992 return error_mark_node;
1997 if (TREE_DEPRECATED (member))
1998 warn_deprecated_use (member);
2000 expr = build_class_member_access_expr (object, member, access_path,
2001 /*preserve_reference=*/false);
2002 if (processing_template_decl && expr != error_mark_node)
2003 return build_min_non_dep (COMPONENT_REF, expr,
2004 orig_object, orig_name, NULL_TREE);
2008 /* Return an expression for the MEMBER_NAME field in the internal
2009 representation of PTRMEM, a pointer-to-member function. (Each
2010 pointer-to-member function type gets its own RECORD_TYPE so it is
2011 more convenient to access the fields by name than by FIELD_DECL.)
2012 This routine converts the NAME to a FIELD_DECL and then creates the
2013 node for the complete expression. */
2016 build_ptrmemfunc_access_expr (tree ptrmem, tree member_name)
2022 /* This code is a stripped down version of
2023 build_class_member_access_expr. It does not work to use that
2024 routine directly because it expects the object to be of class
2026 ptrmem_type = TREE_TYPE (ptrmem);
2027 gcc_assert (TYPE_PTRMEMFUNC_P (ptrmem_type));
2028 member = lookup_member (ptrmem_type, member_name, /*protect=*/0,
2029 /*want_type=*/false);
2030 member_type = cp_build_qualified_type (TREE_TYPE (member),
2031 cp_type_quals (ptrmem_type));
2032 return fold (build3 (COMPONENT_REF, member_type,
2033 ptrmem, member, NULL_TREE));
2036 /* Given an expression PTR for a pointer, return an expression
2037 for the value pointed to.
2038 ERRORSTRING is the name of the operator to appear in error messages.
2040 This function may need to overload OPERATOR_FNNAME.
2041 Must also handle REFERENCE_TYPEs for C++. */
2044 build_x_indirect_ref (tree expr, const char *errorstring)
2046 tree orig_expr = expr;
2049 if (processing_template_decl)
2051 if (type_dependent_expression_p (expr))
2052 return build_min_nt (INDIRECT_REF, expr);
2053 expr = build_non_dependent_expr (expr);
2056 rval = build_new_op (INDIRECT_REF, LOOKUP_NORMAL, expr, NULL_TREE,
2057 NULL_TREE, /*overloaded_p=*/NULL);
2059 rval = build_indirect_ref (expr, errorstring);
2061 if (processing_template_decl && rval != error_mark_node)
2062 return build_min_non_dep (INDIRECT_REF, rval, orig_expr);
2068 build_indirect_ref (tree ptr, const char *errorstring)
2072 if (ptr == error_mark_node)
2073 return error_mark_node;
2075 if (ptr == current_class_ptr)
2076 return current_class_ref;
2078 pointer = (TREE_CODE (TREE_TYPE (ptr)) == REFERENCE_TYPE
2079 ? ptr : decay_conversion (ptr));
2080 type = TREE_TYPE (pointer);
2082 if (TYPE_PTR_P (type) || TREE_CODE (type) == REFERENCE_TYPE)
2086 If the type of the expression is "pointer to T," the type
2087 of the result is "T."
2089 We must use the canonical variant because certain parts of
2090 the back end, like fold, do pointer comparisons between
2092 tree t = canonical_type_variant (TREE_TYPE (type));
2094 if (VOID_TYPE_P (t))
2096 /* A pointer to incomplete type (other than cv void) can be
2097 dereferenced [expr.unary.op]/1 */
2098 error ("`%T' is not a pointer-to-object type", type);
2099 return error_mark_node;
2101 else if (TREE_CODE (pointer) == ADDR_EXPR
2102 && same_type_p (t, TREE_TYPE (TREE_OPERAND (pointer, 0))))
2103 /* The POINTER was something like `&x'. We simplify `*&x' to
2105 return TREE_OPERAND (pointer, 0);
2108 tree ref = build1 (INDIRECT_REF, t, pointer);
2110 /* We *must* set TREE_READONLY when dereferencing a pointer to const,
2111 so that we get the proper error message if the result is used
2112 to assign to. Also, &* is supposed to be a no-op. */
2113 TREE_READONLY (ref) = CP_TYPE_CONST_P (t);
2114 TREE_THIS_VOLATILE (ref) = CP_TYPE_VOLATILE_P (t);
2115 TREE_SIDE_EFFECTS (ref)
2116 = (TREE_THIS_VOLATILE (ref) || TREE_SIDE_EFFECTS (pointer));
2120 /* `pointer' won't be an error_mark_node if we were given a
2121 pointer to member, so it's cool to check for this here. */
2122 else if (TYPE_PTR_TO_MEMBER_P (type))
2123 error ("invalid use of `%s' on pointer to member", errorstring);
2124 else if (pointer != error_mark_node)
2127 error ("invalid type argument of `%s'", errorstring);
2129 error ("invalid type argument");
2131 return error_mark_node;
2134 /* This handles expressions of the form "a[i]", which denotes
2137 This is logically equivalent in C to *(a+i), but we may do it differently.
2138 If A is a variable or a member, we generate a primitive ARRAY_REF.
2139 This avoids forcing the array out of registers, and can work on
2140 arrays that are not lvalues (for example, members of structures returned
2143 If INDEX is of some user-defined type, it must be converted to
2144 integer type. Otherwise, to make a compatible PLUS_EXPR, it
2145 will inherit the type of the array, which will be some pointer type. */
2148 build_array_ref (tree array, tree idx)
2152 error ("subscript missing in array reference");
2153 return error_mark_node;
2156 if (TREE_TYPE (array) == error_mark_node
2157 || TREE_TYPE (idx) == error_mark_node)
2158 return error_mark_node;
2160 /* If ARRAY is a COMPOUND_EXPR or COND_EXPR, move our reference
2162 switch (TREE_CODE (array))
2166 tree value = build_array_ref (TREE_OPERAND (array, 1), idx);
2167 return build2 (COMPOUND_EXPR, TREE_TYPE (value),
2168 TREE_OPERAND (array, 0), value);
2172 return build_conditional_expr
2173 (TREE_OPERAND (array, 0),
2174 build_array_ref (TREE_OPERAND (array, 1), idx),
2175 build_array_ref (TREE_OPERAND (array, 2), idx));
2181 if (TREE_CODE (TREE_TYPE (array)) == ARRAY_TYPE)
2185 /* Subscripting with type char is likely to lose
2186 on a machine where chars are signed.
2187 So warn on any machine, but optionally.
2188 Don't warn for unsigned char since that type is safe.
2189 Don't warn for signed char because anyone who uses that
2190 must have done so deliberately. */
2191 if (warn_char_subscripts
2192 && TYPE_MAIN_VARIANT (TREE_TYPE (idx)) == char_type_node)
2193 warning ("array subscript has type `char'");
2195 if (!INTEGRAL_OR_ENUMERATION_TYPE_P (TREE_TYPE (idx)))
2197 error ("array subscript is not an integer");
2198 return error_mark_node;
2201 /* Apply integral promotions *after* noticing character types.
2202 (It is unclear why we do these promotions -- the standard
2203 does not say that we should. In fact, the natual thing would
2204 seem to be to convert IDX to ptrdiff_t; we're performing
2205 pointer arithmetic.) */
2206 idx = perform_integral_promotions (idx);
2208 /* An array that is indexed by a non-constant
2209 cannot be stored in a register; we must be able to do
2210 address arithmetic on its address.
2211 Likewise an array of elements of variable size. */
2212 if (TREE_CODE (idx) != INTEGER_CST
2213 || (COMPLETE_TYPE_P (TREE_TYPE (TREE_TYPE (array)))
2214 && (TREE_CODE (TYPE_SIZE (TREE_TYPE (TREE_TYPE (array))))
2217 if (!cxx_mark_addressable (array))
2218 return error_mark_node;
2221 /* An array that is indexed by a constant value which is not within
2222 the array bounds cannot be stored in a register either; because we
2223 would get a crash in store_bit_field/extract_bit_field when trying
2224 to access a non-existent part of the register. */
2225 if (TREE_CODE (idx) == INTEGER_CST
2226 && TYPE_DOMAIN (TREE_TYPE (array))
2227 && ! int_fits_type_p (idx, TYPE_DOMAIN (TREE_TYPE (array))))
2229 if (!cxx_mark_addressable (array))
2230 return error_mark_node;
2233 if (pedantic && !lvalue_p (array))
2234 pedwarn ("ISO C++ forbids subscripting non-lvalue array");
2236 /* Note in C++ it is valid to subscript a `register' array, since
2237 it is valid to take the address of something with that
2238 storage specification. */
2242 while (TREE_CODE (foo) == COMPONENT_REF)
2243 foo = TREE_OPERAND (foo, 0);
2244 if (TREE_CODE (foo) == VAR_DECL && DECL_REGISTER (foo))
2245 warning ("subscripting array declared `register'");
2248 type = TREE_TYPE (TREE_TYPE (array));
2249 rval = build4 (ARRAY_REF, type, array, idx, NULL_TREE, NULL_TREE);
2250 /* Array ref is const/volatile if the array elements are
2251 or if the array is.. */
2252 TREE_READONLY (rval)
2253 |= (CP_TYPE_CONST_P (type) | TREE_READONLY (array));
2254 TREE_SIDE_EFFECTS (rval)
2255 |= (CP_TYPE_VOLATILE_P (type) | TREE_SIDE_EFFECTS (array));
2256 TREE_THIS_VOLATILE (rval)
2257 |= (CP_TYPE_VOLATILE_P (type) | TREE_THIS_VOLATILE (array));
2258 return require_complete_type (fold (rval));
2262 tree ar = default_conversion (array);
2263 tree ind = default_conversion (idx);
2265 /* Put the integer in IND to simplify error checking. */
2266 if (TREE_CODE (TREE_TYPE (ar)) == INTEGER_TYPE)
2273 if (ar == error_mark_node)
2276 if (TREE_CODE (TREE_TYPE (ar)) != POINTER_TYPE)
2278 error ("subscripted value is neither array nor pointer");
2279 return error_mark_node;
2281 if (TREE_CODE (TREE_TYPE (ind)) != INTEGER_TYPE)
2283 error ("array subscript is not an integer");
2284 return error_mark_node;
2287 return build_indirect_ref (cp_build_binary_op (PLUS_EXPR, ar, ind),
2292 /* Resolve a pointer to member function. INSTANCE is the object
2293 instance to use, if the member points to a virtual member.
2295 This used to avoid checking for virtual functions if basetype
2296 has no virtual functions, according to an earlier ANSI draft.
2297 With the final ISO C++ rules, such an optimization is
2298 incorrect: A pointer to a derived member can be static_cast
2299 to pointer-to-base-member, as long as the dynamic object
2300 later has the right member. */
2303 get_member_function_from_ptrfunc (tree *instance_ptrptr, tree function)
2305 if (TREE_CODE (function) == OFFSET_REF)
2306 function = TREE_OPERAND (function, 1);
2308 if (TYPE_PTRMEMFUNC_P (TREE_TYPE (function)))
2310 tree idx, delta, e1, e2, e3, vtbl, basetype;
2311 tree fntype = TYPE_PTRMEMFUNC_FN_TYPE (TREE_TYPE (function));
2313 tree instance_ptr = *instance_ptrptr;
2314 tree instance_save_expr = 0;
2315 if (instance_ptr == error_mark_node)
2317 if (TREE_CODE (function) == PTRMEM_CST)
2319 /* Extracting the function address from a pmf is only
2320 allowed with -Wno-pmf-conversions. It only works for
2322 e1 = build_addr_func (PTRMEM_CST_MEMBER (function));
2323 e1 = convert (fntype, e1);
2328 error ("object missing in use of `%E'", function);
2329 return error_mark_node;
2333 if (TREE_SIDE_EFFECTS (instance_ptr))
2334 instance_ptr = instance_save_expr = save_expr (instance_ptr);
2336 if (TREE_SIDE_EFFECTS (function))
2337 function = save_expr (function);
2339 /* Start by extracting all the information from the PMF itself. */
2340 e3 = PFN_FROM_PTRMEMFUNC (function);
2341 delta = build_ptrmemfunc_access_expr (function, delta_identifier);
2342 idx = build1 (NOP_EXPR, vtable_index_type, e3);
2343 switch (TARGET_PTRMEMFUNC_VBIT_LOCATION)
2345 case ptrmemfunc_vbit_in_pfn:
2346 e1 = cp_build_binary_op (BIT_AND_EXPR, idx, integer_one_node);
2347 idx = cp_build_binary_op (MINUS_EXPR, idx, integer_one_node);
2350 case ptrmemfunc_vbit_in_delta:
2351 e1 = cp_build_binary_op (BIT_AND_EXPR, delta, integer_one_node);
2352 delta = cp_build_binary_op (RSHIFT_EXPR, delta, integer_one_node);
2359 /* Convert down to the right base before using the instance. First
2361 basetype = TYPE_METHOD_BASETYPE (TREE_TYPE (fntype));
2362 basetype = lookup_base (TREE_TYPE (TREE_TYPE (instance_ptr)),
2363 basetype, ba_check, NULL);
2364 instance_ptr = build_base_path (PLUS_EXPR, instance_ptr, basetype, 1);
2365 if (instance_ptr == error_mark_node)
2366 return error_mark_node;
2367 /* ...and then the delta in the PMF. */
2368 instance_ptr = build2 (PLUS_EXPR, TREE_TYPE (instance_ptr),
2369 instance_ptr, delta);
2371 /* Hand back the adjusted 'this' argument to our caller. */
2372 *instance_ptrptr = instance_ptr;
2374 /* Next extract the vtable pointer from the object. */
2375 vtbl = build1 (NOP_EXPR, build_pointer_type (vtbl_ptr_type_node),
2377 vtbl = build_indirect_ref (vtbl, NULL);
2379 /* Finally, extract the function pointer from the vtable. */
2380 e2 = fold (build2 (PLUS_EXPR, TREE_TYPE (vtbl), vtbl, idx));
2381 e2 = build_indirect_ref (e2, NULL);
2382 TREE_CONSTANT (e2) = 1;
2383 TREE_INVARIANT (e2) = 1;
2385 /* When using function descriptors, the address of the
2386 vtable entry is treated as a function pointer. */
2387 if (TARGET_VTABLE_USES_DESCRIPTORS)
2388 e2 = build1 (NOP_EXPR, TREE_TYPE (e2),
2389 build_unary_op (ADDR_EXPR, e2, /*noconvert=*/1));
2391 TREE_TYPE (e2) = TREE_TYPE (e3);
2392 e1 = build_conditional_expr (e1, e2, e3);
2394 /* Make sure this doesn't get evaluated first inside one of the
2395 branches of the COND_EXPR. */
2396 if (instance_save_expr)
2397 e1 = build2 (COMPOUND_EXPR, TREE_TYPE (e1),
2398 instance_save_expr, e1);
2406 build_function_call (tree function, tree params)
2408 tree fntype, fndecl;
2409 tree coerced_params;
2410 tree name = NULL_TREE;
2412 tree original = function;
2414 /* build_c_cast puts on a NOP_EXPR to make the result not an lvalue.
2415 Strip such NOP_EXPRs, since FUNCTION is used in non-lvalue context. */
2416 if (TREE_CODE (function) == NOP_EXPR
2417 && TREE_TYPE (function) == TREE_TYPE (TREE_OPERAND (function, 0)))
2418 function = TREE_OPERAND (function, 0);
2420 if (TREE_CODE (function) == FUNCTION_DECL)
2422 name = DECL_NAME (function);
2424 mark_used (function);
2427 /* Convert anything with function type to a pointer-to-function. */
2428 if (pedantic && DECL_MAIN_P (function))
2429 pedwarn ("ISO C++ forbids calling `::main' from within program");
2431 /* Differs from default_conversion by not setting TREE_ADDRESSABLE
2432 (because calling an inline function does not mean the function
2433 needs to be separately compiled). */
2435 if (DECL_INLINE (function))
2436 function = inline_conversion (function);
2438 function = build_addr_func (function);
2444 function = build_addr_func (function);
2447 if (function == error_mark_node)
2448 return error_mark_node;
2450 fntype = TREE_TYPE (function);
2452 if (TYPE_PTRMEMFUNC_P (fntype))
2454 error ("must use .* or ->* to call pointer-to-member function in `%E (...)'",
2456 return error_mark_node;
2459 is_method = (TREE_CODE (fntype) == POINTER_TYPE
2460 && TREE_CODE (TREE_TYPE (fntype)) == METHOD_TYPE);
2462 if (!((TREE_CODE (fntype) == POINTER_TYPE
2463 && TREE_CODE (TREE_TYPE (fntype)) == FUNCTION_TYPE)
2465 || TREE_CODE (function) == TEMPLATE_ID_EXPR))
2467 error ("`%E' cannot be used as a function", original);
2468 return error_mark_node;
2471 /* fntype now gets the type of function pointed to. */
2472 fntype = TREE_TYPE (fntype);
2474 /* Convert the parameters to the types declared in the
2475 function prototype, or apply default promotions. */
2477 coerced_params = convert_arguments (TYPE_ARG_TYPES (fntype),
2478 params, fndecl, LOOKUP_NORMAL);
2479 if (coerced_params == error_mark_node)
2480 return error_mark_node;
2482 /* Check for errors in format strings and inappropriately
2485 check_function_arguments (TYPE_ATTRIBUTES (fntype), coerced_params);
2487 return build_cxx_call (function, coerced_params);
2490 /* Convert the actual parameter expressions in the list VALUES
2491 to the types in the list TYPELIST.
2492 If parmdecls is exhausted, or when an element has NULL as its type,
2493 perform the default conversions.
2495 NAME is an IDENTIFIER_NODE or 0. It is used only for error messages.
2497 This is also where warnings about wrong number of args are generated.
2499 Return a list of expressions for the parameters as converted.
2501 Both VALUES and the returned value are chains of TREE_LIST nodes
2502 with the elements of the list in the TREE_VALUE slots of those nodes.
2504 In C++, unspecified trailing parameters can be filled in with their
2505 default arguments, if such were specified. Do so here. */
2508 convert_arguments (tree typelist, tree values, tree fndecl, int flags)
2510 tree typetail, valtail;
2511 tree result = NULL_TREE;
2512 const char *called_thing = 0;
2515 /* Argument passing is always copy-initialization. */
2516 flags |= LOOKUP_ONLYCONVERTING;
2520 if (TREE_CODE (TREE_TYPE (fndecl)) == METHOD_TYPE)
2522 if (DECL_NAME (fndecl) == NULL_TREE
2523 || IDENTIFIER_HAS_TYPE_VALUE (DECL_NAME (fndecl)))
2524 called_thing = "constructor";
2526 called_thing = "member function";
2529 called_thing = "function";
2532 for (valtail = values, typetail = typelist;
2534 valtail = TREE_CHAIN (valtail), i++)
2536 tree type = typetail ? TREE_VALUE (typetail) : 0;
2537 tree val = TREE_VALUE (valtail);
2539 if (val == error_mark_node)
2540 return error_mark_node;
2542 if (type == void_type_node)
2546 cp_error_at ("too many arguments to %s `%+#D'", called_thing,
2548 error ("at this point in file");
2551 error ("too many arguments to function");
2552 /* In case anybody wants to know if this argument
2555 TREE_TYPE (tree_last (result)) = error_mark_node;
2559 /* build_c_cast puts on a NOP_EXPR to make the result not an lvalue.
2560 Strip such NOP_EXPRs, since VAL is used in non-lvalue context. */
2561 if (TREE_CODE (val) == NOP_EXPR
2562 && TREE_TYPE (val) == TREE_TYPE (TREE_OPERAND (val, 0))
2563 && (type == 0 || TREE_CODE (type) != REFERENCE_TYPE))
2564 val = TREE_OPERAND (val, 0);
2566 if (type == 0 || TREE_CODE (type) != REFERENCE_TYPE)
2568 if (TREE_CODE (TREE_TYPE (val)) == ARRAY_TYPE
2569 || TREE_CODE (TREE_TYPE (val)) == FUNCTION_TYPE
2570 || TREE_CODE (TREE_TYPE (val)) == METHOD_TYPE)
2571 val = decay_conversion (val);
2574 if (val == error_mark_node)
2575 return error_mark_node;
2579 /* Formal parm type is specified by a function prototype. */
2582 if (!COMPLETE_TYPE_P (complete_type (type)))
2585 error ("parameter %P of `%D' has incomplete type `%T'",
2588 error ("parameter %P has incomplete type `%T'", i, type);
2589 parmval = error_mark_node;
2593 parmval = convert_for_initialization
2594 (NULL_TREE, type, val, flags,
2595 "argument passing", fndecl, i);
2596 parmval = convert_for_arg_passing (type, parmval);
2599 if (parmval == error_mark_node)
2600 return error_mark_node;
2602 result = tree_cons (NULL_TREE, parmval, result);
2606 if (TREE_CODE (TREE_TYPE (val)) == REFERENCE_TYPE)
2607 val = convert_from_reference (val);
2609 if (fndecl && DECL_BUILT_IN (fndecl)
2610 && DECL_FUNCTION_CODE (fndecl) == BUILT_IN_CONSTANT_P)
2611 /* Don't do ellipsis conversion for __built_in_constant_p
2612 as this will result in spurious warnings for non-POD
2614 val = require_complete_type (val);
2616 val = convert_arg_to_ellipsis (val);
2618 result = tree_cons (NULL_TREE, val, result);
2622 typetail = TREE_CHAIN (typetail);
2625 if (typetail != 0 && typetail != void_list_node)
2627 /* See if there are default arguments that can be used. */
2628 if (TREE_PURPOSE (typetail)
2629 && TREE_CODE (TREE_PURPOSE (typetail)) != DEFAULT_ARG)
2631 for (; typetail != void_list_node; ++i)
2634 = convert_default_arg (TREE_VALUE (typetail),
2635 TREE_PURPOSE (typetail),
2638 if (parmval == error_mark_node)
2639 return error_mark_node;
2641 result = tree_cons (0, parmval, result);
2642 typetail = TREE_CHAIN (typetail);
2643 /* ends with `...'. */
2644 if (typetail == NULL_TREE)
2652 cp_error_at ("too few arguments to %s `%+#D'",
2653 called_thing, fndecl);
2654 error ("at this point in file");
2657 error ("too few arguments to function");
2658 return error_mark_list;
2662 return nreverse (result);
2665 /* Build a binary-operation expression, after performing default
2666 conversions on the operands. CODE is the kind of expression to build. */
2669 build_x_binary_op (enum tree_code code, tree arg1, tree arg2,
2679 if (processing_template_decl)
2681 if (type_dependent_expression_p (arg1)
2682 || type_dependent_expression_p (arg2))
2683 return build_min_nt (code, arg1, arg2);
2684 arg1 = build_non_dependent_expr (arg1);
2685 arg2 = build_non_dependent_expr (arg2);
2688 if (code == DOTSTAR_EXPR)
2689 expr = build_m_component_ref (arg1, arg2);
2691 expr = build_new_op (code, LOOKUP_NORMAL, arg1, arg2, NULL_TREE,
2694 if (processing_template_decl && expr != error_mark_node)
2695 return build_min_non_dep (code, expr, orig_arg1, orig_arg2);
2700 /* Build a binary-operation expression without default conversions.
2701 CODE is the kind of expression to build.
2702 This function differs from `build' in several ways:
2703 the data type of the result is computed and recorded in it,
2704 warnings are generated if arg data types are invalid,
2705 special handling for addition and subtraction of pointers is known,
2706 and some optimization is done (operations on narrow ints
2707 are done in the narrower type when that gives the same result).
2708 Constant folding is also done before the result is returned.
2710 Note that the operands will never have enumeral types
2711 because either they have just had the default conversions performed
2712 or they have both just been converted to some other type in which
2713 the arithmetic is to be done.
2715 C++: must do special pointer arithmetic when implementing
2716 multiple inheritance, and deal with pointer to member functions. */
2719 build_binary_op (enum tree_code code, tree orig_op0, tree orig_op1,
2720 int convert_p ATTRIBUTE_UNUSED)
2723 enum tree_code code0, code1;
2726 /* Expression code to give to the expression when it is built.
2727 Normally this is CODE, which is what the caller asked for,
2728 but in some special cases we change it. */
2729 enum tree_code resultcode = code;
2731 /* Data type in which the computation is to be performed.
2732 In the simplest cases this is the common type of the arguments. */
2733 tree result_type = NULL;
2735 /* Nonzero means operands have already been type-converted
2736 in whatever way is necessary.
2737 Zero means they need to be converted to RESULT_TYPE. */
2740 /* Nonzero means create the expression with this type, rather than
2742 tree build_type = 0;
2744 /* Nonzero means after finally constructing the expression
2745 convert it to this type. */
2746 tree final_type = 0;
2748 /* Nonzero if this is an operation like MIN or MAX which can
2749 safely be computed in short if both args are promoted shorts.
2750 Also implies COMMON.
2751 -1 indicates a bitwise operation; this makes a difference
2752 in the exact conditions for when it is safe to do the operation
2753 in a narrower mode. */
2756 /* Nonzero if this is a comparison operation;
2757 if both args are promoted shorts, compare the original shorts.
2758 Also implies COMMON. */
2759 int short_compare = 0;
2761 /* Nonzero if this is a right-shift operation, which can be computed on the
2762 original short and then promoted if the operand is a promoted short. */
2763 int short_shift = 0;
2765 /* Nonzero means set RESULT_TYPE to the common type of the args. */
2768 /* Apply default conversions. */
2772 if (code == TRUTH_AND_EXPR || code == TRUTH_ANDIF_EXPR
2773 || code == TRUTH_OR_EXPR || code == TRUTH_ORIF_EXPR
2774 || code == TRUTH_XOR_EXPR)
2776 if (!really_overloaded_fn (op0))
2777 op0 = decay_conversion (op0);
2778 if (!really_overloaded_fn (op1))
2779 op1 = decay_conversion (op1);
2783 if (!really_overloaded_fn (op0))
2784 op0 = default_conversion (op0);
2785 if (!really_overloaded_fn (op1))
2786 op1 = default_conversion (op1);
2789 /* Strip NON_LVALUE_EXPRs, etc., since we aren't using as an lvalue. */
2790 STRIP_TYPE_NOPS (op0);
2791 STRIP_TYPE_NOPS (op1);
2793 /* DTRT if one side is an overloaded function, but complain about it. */
2794 if (type_unknown_p (op0))
2796 tree t = instantiate_type (TREE_TYPE (op1), op0, tf_none);
2797 if (t != error_mark_node)
2799 pedwarn ("assuming cast to type `%T' from overloaded function",
2804 if (type_unknown_p (op1))
2806 tree t = instantiate_type (TREE_TYPE (op0), op1, tf_none);
2807 if (t != error_mark_node)
2809 pedwarn ("assuming cast to type `%T' from overloaded function",
2815 type0 = TREE_TYPE (op0);
2816 type1 = TREE_TYPE (op1);
2818 /* The expression codes of the data types of the arguments tell us
2819 whether the arguments are integers, floating, pointers, etc. */
2820 code0 = TREE_CODE (type0);
2821 code1 = TREE_CODE (type1);
2823 /* If an error was already reported for one of the arguments,
2824 avoid reporting another error. */
2826 if (code0 == ERROR_MARK || code1 == ERROR_MARK)
2827 return error_mark_node;
2832 /* Handle the pointer + int case. */
2833 if (code0 == POINTER_TYPE && code1 == INTEGER_TYPE)
2834 return cp_pointer_int_sum (PLUS_EXPR, op0, op1);
2835 else if (code1 == POINTER_TYPE && code0 == INTEGER_TYPE)
2836 return cp_pointer_int_sum (PLUS_EXPR, op1, op0);
2842 /* Subtraction of two similar pointers.
2843 We must subtract them as integers, then divide by object size. */
2844 if (code0 == POINTER_TYPE && code1 == POINTER_TYPE
2845 && same_type_ignoring_top_level_qualifiers_p (TREE_TYPE (type0),
2847 return pointer_diff (op0, op1, common_type (type0, type1));
2848 /* Handle pointer minus int. Just like pointer plus int. */
2849 else if (code0 == POINTER_TYPE && code1 == INTEGER_TYPE)
2850 return cp_pointer_int_sum (MINUS_EXPR, op0, op1);
2859 case TRUNC_DIV_EXPR:
2861 case FLOOR_DIV_EXPR:
2862 case ROUND_DIV_EXPR:
2863 case EXACT_DIV_EXPR:
2864 if ((code0 == INTEGER_TYPE || code0 == REAL_TYPE
2865 || code0 == COMPLEX_TYPE || code0 == VECTOR_TYPE)
2866 && (code1 == INTEGER_TYPE || code1 == REAL_TYPE
2867 || code1 == COMPLEX_TYPE || code1 == VECTOR_TYPE))
2869 if (TREE_CODE (op1) == INTEGER_CST && integer_zerop (op1))
2870 warning ("division by zero in `%E / 0'", op0);
2871 else if (TREE_CODE (op1) == REAL_CST && real_zerop (op1))
2872 warning ("division by zero in `%E / 0.'", op0);
2874 if (code0 == COMPLEX_TYPE || code0 == VECTOR_TYPE)
2875 code0 = TREE_CODE (TREE_TYPE (TREE_TYPE (op0)));
2876 if (code1 == COMPLEX_TYPE || code1 == VECTOR_TYPE)
2877 code1 = TREE_CODE (TREE_TYPE (TREE_TYPE (op1)));
2879 if (!(code0 == INTEGER_TYPE && code1 == INTEGER_TYPE))
2880 resultcode = RDIV_EXPR;
2882 /* When dividing two signed integers, we have to promote to int.
2883 unless we divide by a constant != -1. Note that default
2884 conversion will have been performed on the operands at this
2885 point, so we have to dig out the original type to find out if
2887 shorten = ((TREE_CODE (op0) == NOP_EXPR
2888 && TYPE_UNSIGNED (TREE_TYPE (TREE_OPERAND (op0, 0))))
2889 || (TREE_CODE (op1) == INTEGER_CST
2890 && ! integer_all_onesp (op1)));
2899 if (code0 == INTEGER_TYPE && code1 == INTEGER_TYPE)
2903 case TRUNC_MOD_EXPR:
2904 case FLOOR_MOD_EXPR:
2905 if (code1 == INTEGER_TYPE && integer_zerop (op1))
2906 warning ("division by zero in `%E %% 0'", op0);
2907 else if (code1 == REAL_TYPE && real_zerop (op1))
2908 warning ("division by zero in `%E %% 0.'", op0);
2910 if (code0 == INTEGER_TYPE && code1 == INTEGER_TYPE)
2912 /* Although it would be tempting to shorten always here, that loses
2913 on some targets, since the modulo instruction is undefined if the
2914 quotient can't be represented in the computation mode. We shorten
2915 only if unsigned or if dividing by something we know != -1. */
2916 shorten = ((TREE_CODE (op0) == NOP_EXPR
2917 && TYPE_UNSIGNED (TREE_TYPE (TREE_OPERAND (op0, 0))))
2918 || (TREE_CODE (op1) == INTEGER_CST
2919 && ! integer_all_onesp (op1)));
2924 case TRUTH_ANDIF_EXPR:
2925 case TRUTH_ORIF_EXPR:
2926 case TRUTH_AND_EXPR:
2928 result_type = boolean_type_node;
2931 /* Shift operations: result has same type as first operand;
2932 always convert second operand to int.
2933 Also set SHORT_SHIFT if shifting rightward. */
2936 if (code0 == INTEGER_TYPE && code1 == INTEGER_TYPE)
2938 result_type = type0;
2939 if (TREE_CODE (op1) == INTEGER_CST)
2941 if (tree_int_cst_lt (op1, integer_zero_node))
2942 warning ("right shift count is negative");
2945 if (! integer_zerop (op1))
2947 if (compare_tree_int (op1, TYPE_PRECISION (type0)) >= 0)
2948 warning ("right shift count >= width of type");
2951 /* Convert the shift-count to an integer, regardless of
2952 size of value being shifted. */
2953 if (TYPE_MAIN_VARIANT (TREE_TYPE (op1)) != integer_type_node)
2954 op1 = cp_convert (integer_type_node, op1);
2955 /* Avoid converting op1 to result_type later. */
2961 if (code0 == INTEGER_TYPE && code1 == INTEGER_TYPE)
2963 result_type = type0;
2964 if (TREE_CODE (op1) == INTEGER_CST)
2966 if (tree_int_cst_lt (op1, integer_zero_node))
2967 warning ("left shift count is negative");
2968 else if (compare_tree_int (op1, TYPE_PRECISION (type0)) >= 0)
2969 warning ("left shift count >= width of type");
2971 /* Convert the shift-count to an integer, regardless of
2972 size of value being shifted. */
2973 if (TYPE_MAIN_VARIANT (TREE_TYPE (op1)) != integer_type_node)
2974 op1 = cp_convert (integer_type_node, op1);
2975 /* Avoid converting op1 to result_type later. */
2982 if (code0 == INTEGER_TYPE && code1 == INTEGER_TYPE)
2984 result_type = type0;
2985 if (TREE_CODE (op1) == INTEGER_CST)
2987 if (tree_int_cst_lt (op1, integer_zero_node))
2988 warning ("%s rotate count is negative",
2989 (code == LROTATE_EXPR) ? "left" : "right");
2990 else if (compare_tree_int (op1, TYPE_PRECISION (type0)) >= 0)
2991 warning ("%s rotate count >= width of type",
2992 (code == LROTATE_EXPR) ? "left" : "right");
2994 /* Convert the shift-count to an integer, regardless of
2995 size of value being shifted. */
2996 if (TYPE_MAIN_VARIANT (TREE_TYPE (op1)) != integer_type_node)
2997 op1 = cp_convert (integer_type_node, op1);
3003 if (warn_float_equal && (code0 == REAL_TYPE || code1 == REAL_TYPE))
3004 warning ("comparing floating point with == or != is unsafe");
3006 build_type = boolean_type_node;
3007 if ((code0 == INTEGER_TYPE || code0 == REAL_TYPE
3008 || code0 == COMPLEX_TYPE)
3009 && (code1 == INTEGER_TYPE || code1 == REAL_TYPE
3010 || code1 == COMPLEX_TYPE))
3012 else if ((code0 == POINTER_TYPE && code1 == POINTER_TYPE)
3013 || (TYPE_PTRMEM_P (type0) && TYPE_PTRMEM_P (type1)))
3014 result_type = composite_pointer_type (type0, type1, op0, op1,
3016 else if ((code0 == POINTER_TYPE || TYPE_PTRMEM_P (type0))
3017 && null_ptr_cst_p (op1))
3018 result_type = type0;
3019 else if ((code1 == POINTER_TYPE || TYPE_PTRMEM_P (type1))
3020 && null_ptr_cst_p (op0))
3021 result_type = type1;
3022 else if (code0 == POINTER_TYPE && code1 == INTEGER_TYPE)
3024 result_type = type0;
3025 error ("ISO C++ forbids comparison between pointer and integer");
3027 else if (code0 == INTEGER_TYPE && code1 == POINTER_TYPE)
3029 result_type = type1;
3030 error ("ISO C++ forbids comparison between pointer and integer");
3032 else if (TYPE_PTRMEMFUNC_P (type0) && null_ptr_cst_p (op1))
3034 op0 = build_ptrmemfunc_access_expr (op0, pfn_identifier);
3035 op1 = cp_convert (TREE_TYPE (op0), integer_zero_node);
3036 result_type = TREE_TYPE (op0);
3038 else if (TYPE_PTRMEMFUNC_P (type1) && null_ptr_cst_p (op0))
3039 return cp_build_binary_op (code, op1, op0);
3040 else if (TYPE_PTRMEMFUNC_P (type0) && TYPE_PTRMEMFUNC_P (type1)
3041 && same_type_p (type0, type1))
3043 /* E will be the final comparison. */
3045 /* E1 and E2 are for scratch. */
3053 if (TREE_SIDE_EFFECTS (op0))
3054 op0 = save_expr (op0);
3055 if (TREE_SIDE_EFFECTS (op1))
3056 op1 = save_expr (op1);
3061 && (!op0.pfn || op0.delta == op1.delta))
3063 The reason for the `!op0.pfn' bit is that a NULL
3064 pointer-to-member is any member with a zero PFN; the
3065 DELTA field is unspecified. */
3066 pfn0 = pfn_from_ptrmemfunc (op0);
3067 pfn1 = pfn_from_ptrmemfunc (op1);
3068 delta0 = build_ptrmemfunc_access_expr (op0,
3070 delta1 = build_ptrmemfunc_access_expr (op1,
3072 e1 = cp_build_binary_op (EQ_EXPR, delta0, delta1);
3073 e2 = cp_build_binary_op (EQ_EXPR,
3075 cp_convert (TREE_TYPE (pfn0),
3076 integer_zero_node));
3077 e1 = cp_build_binary_op (TRUTH_ORIF_EXPR, e1, e2);
3078 e2 = build2 (EQ_EXPR, boolean_type_node, pfn0, pfn1);
3079 e = cp_build_binary_op (TRUTH_ANDIF_EXPR, e2, e1);
3080 if (code == EQ_EXPR)
3082 return cp_build_binary_op (EQ_EXPR, e, integer_zero_node);
3084 else if ((TYPE_PTRMEMFUNC_P (type0)
3085 && same_type_p (TYPE_PTRMEMFUNC_FN_TYPE (type0), type1))
3086 || (TYPE_PTRMEMFUNC_P (type1)
3087 && same_type_p (TYPE_PTRMEMFUNC_FN_TYPE (type1), type0)))
3093 if ((code0 == INTEGER_TYPE || code0 == REAL_TYPE)
3094 && (code1 == INTEGER_TYPE || code1 == REAL_TYPE))
3096 else if (code0 == POINTER_TYPE && code1 == POINTER_TYPE)
3097 result_type = composite_pointer_type (type0, type1, op0, op1,
3105 build_type = boolean_type_node;
3106 if ((code0 == INTEGER_TYPE || code0 == REAL_TYPE)
3107 && (code1 == INTEGER_TYPE || code1 == REAL_TYPE))
3109 else if (code0 == POINTER_TYPE && code1 == POINTER_TYPE)
3110 result_type = composite_pointer_type (type0, type1, op0, op1,
3112 else if (code0 == POINTER_TYPE && TREE_CODE (op1) == INTEGER_CST
3113 && integer_zerop (op1))
3114 result_type = type0;
3115 else if (code1 == POINTER_TYPE && TREE_CODE (op0) == INTEGER_CST
3116 && integer_zerop (op0))
3117 result_type = type1;
3118 else if (code0 == POINTER_TYPE && code1 == INTEGER_TYPE)
3120 result_type = type0;
3121 pedwarn ("ISO C++ forbids comparison between pointer and integer");
3123 else if (code0 == INTEGER_TYPE && code1 == POINTER_TYPE)
3125 result_type = type1;
3126 pedwarn ("ISO C++ forbids comparison between pointer and integer");
3130 case UNORDERED_EXPR:
3137 build_type = integer_type_node;
3138 if (code0 != REAL_TYPE || code1 != REAL_TYPE)
3140 error ("unordered comparison on non-floating point argument");
3141 return error_mark_node;
3150 if ((code0 == INTEGER_TYPE || code0 == REAL_TYPE || code0 == COMPLEX_TYPE)
3152 (code1 == INTEGER_TYPE || code1 == REAL_TYPE || code1 == COMPLEX_TYPE))
3154 int none_complex = (code0 != COMPLEX_TYPE && code1 != COMPLEX_TYPE);
3156 if (shorten || common || short_compare)
3157 result_type = common_type (type0, type1);
3159 /* For certain operations (which identify themselves by shorten != 0)
3160 if both args were extended from the same smaller type,
3161 do the arithmetic in that type and then extend.
3163 shorten !=0 and !=1 indicates a bitwise operation.
3164 For them, this optimization is safe only if
3165 both args are zero-extended or both are sign-extended.
3166 Otherwise, we might change the result.
3167 Eg, (short)-1 | (unsigned short)-1 is (int)-1
3168 but calculated in (unsigned short) it would be (unsigned short)-1. */
3170 if (shorten && none_complex)
3172 int unsigned0, unsigned1;
3173 tree arg0 = get_narrower (op0, &unsigned0);
3174 tree arg1 = get_narrower (op1, &unsigned1);
3175 /* UNS is 1 if the operation to be done is an unsigned one. */
3176 int uns = TYPE_UNSIGNED (result_type);
3179 final_type = result_type;
3181 /* Handle the case that OP0 does not *contain* a conversion
3182 but it *requires* conversion to FINAL_TYPE. */
3184 if (op0 == arg0 && TREE_TYPE (op0) != final_type)
3185 unsigned0 = TYPE_UNSIGNED (TREE_TYPE (op0));
3186 if (op1 == arg1 && TREE_TYPE (op1) != final_type)
3187 unsigned1 = TYPE_UNSIGNED (TREE_TYPE (op1));
3189 /* Now UNSIGNED0 is 1 if ARG0 zero-extends to FINAL_TYPE. */
3191 /* For bitwise operations, signedness of nominal type
3192 does not matter. Consider only how operands were extended. */
3196 /* Note that in all three cases below we refrain from optimizing
3197 an unsigned operation on sign-extended args.
3198 That would not be valid. */
3200 /* Both args variable: if both extended in same way
3201 from same width, do it in that width.
3202 Do it unsigned if args were zero-extended. */
3203 if ((TYPE_PRECISION (TREE_TYPE (arg0))
3204 < TYPE_PRECISION (result_type))
3205 && (TYPE_PRECISION (TREE_TYPE (arg1))
3206 == TYPE_PRECISION (TREE_TYPE (arg0)))
3207 && unsigned0 == unsigned1
3208 && (unsigned0 || !uns))
3209 result_type = c_common_signed_or_unsigned_type
3210 (unsigned0, common_type (TREE_TYPE (arg0), TREE_TYPE (arg1)));
3211 else if (TREE_CODE (arg0) == INTEGER_CST
3212 && (unsigned1 || !uns)
3213 && (TYPE_PRECISION (TREE_TYPE (arg1))
3214 < TYPE_PRECISION (result_type))
3215 && (type = c_common_signed_or_unsigned_type
3216 (unsigned1, TREE_TYPE (arg1)),
3217 int_fits_type_p (arg0, type)))
3219 else if (TREE_CODE (arg1) == INTEGER_CST
3220 && (unsigned0 || !uns)
3221 && (TYPE_PRECISION (TREE_TYPE (arg0))
3222 < TYPE_PRECISION (result_type))
3223 && (type = c_common_signed_or_unsigned_type
3224 (unsigned0, TREE_TYPE (arg0)),
3225 int_fits_type_p (arg1, type)))
3229 /* Shifts can be shortened if shifting right. */
3234 tree arg0 = get_narrower (op0, &unsigned_arg);
3236 final_type = result_type;
3238 if (arg0 == op0 && final_type == TREE_TYPE (op0))
3239 unsigned_arg = TYPE_UNSIGNED (TREE_TYPE (op0));
3241 if (TYPE_PRECISION (TREE_TYPE (arg0)) < TYPE_PRECISION (result_type)
3242 /* We can shorten only if the shift count is less than the
3243 number of bits in the smaller type size. */
3244 && compare_tree_int (op1, TYPE_PRECISION (TREE_TYPE (arg0))) < 0
3245 /* If arg is sign-extended and then unsigned-shifted,
3246 we can simulate this with a signed shift in arg's type
3247 only if the extended result is at least twice as wide
3248 as the arg. Otherwise, the shift could use up all the
3249 ones made by sign-extension and bring in zeros.
3250 We can't optimize that case at all, but in most machines
3251 it never happens because available widths are 2**N. */
3252 && (!TYPE_UNSIGNED (final_type)
3254 || (((unsigned) 2 * TYPE_PRECISION (TREE_TYPE (arg0)))
3255 <= TYPE_PRECISION (result_type))))
3257 /* Do an unsigned shift if the operand was zero-extended. */
3259 = c_common_signed_or_unsigned_type (unsigned_arg,
3261 /* Convert value-to-be-shifted to that type. */
3262 if (TREE_TYPE (op0) != result_type)
3263 op0 = cp_convert (result_type, op0);
3268 /* Comparison operations are shortened too but differently.
3269 They identify themselves by setting short_compare = 1. */
3273 /* Don't write &op0, etc., because that would prevent op0
3274 from being kept in a register.
3275 Instead, make copies of the our local variables and
3276 pass the copies by reference, then copy them back afterward. */
3277 tree xop0 = op0, xop1 = op1, xresult_type = result_type;
3278 enum tree_code xresultcode = resultcode;
3280 = shorten_compare (&xop0, &xop1, &xresult_type, &xresultcode);
3282 return cp_convert (boolean_type_node, val);
3283 op0 = xop0, op1 = xop1;
3285 resultcode = xresultcode;
3288 if ((short_compare || code == MIN_EXPR || code == MAX_EXPR)
3289 && warn_sign_compare
3290 /* Do not warn until the template is instantiated; we cannot
3291 bound the ranges of the arguments until that point. */
3292 && !processing_template_decl)
3294 int op0_signed = !TYPE_UNSIGNED (TREE_TYPE (orig_op0));
3295 int op1_signed = !TYPE_UNSIGNED (TREE_TYPE (orig_op1));
3297 int unsignedp0, unsignedp1;
3298 tree primop0 = get_narrower (op0, &unsignedp0);
3299 tree primop1 = get_narrower (op1, &unsignedp1);
3301 /* Check for comparison of different enum types. */
3302 if (TREE_CODE (TREE_TYPE (orig_op0)) == ENUMERAL_TYPE
3303 && TREE_CODE (TREE_TYPE (orig_op1)) == ENUMERAL_TYPE
3304 && TYPE_MAIN_VARIANT (TREE_TYPE (orig_op0))
3305 != TYPE_MAIN_VARIANT (TREE_TYPE (orig_op1)))
3307 warning ("comparison between types `%#T' and `%#T'",
3308 TREE_TYPE (orig_op0), TREE_TYPE (orig_op1));
3311 /* Give warnings for comparisons between signed and unsigned
3312 quantities that may fail. */
3313 /* Do the checking based on the original operand trees, so that
3314 casts will be considered, but default promotions won't be. */
3316 /* Do not warn if the comparison is being done in a signed type,
3317 since the signed type will only be chosen if it can represent
3318 all the values of the unsigned type. */
3319 if (!TYPE_UNSIGNED (result_type))
3321 /* Do not warn if both operands are unsigned. */
3322 else if (op0_signed == op1_signed)
3324 /* Do not warn if the signed quantity is an unsuffixed
3325 integer literal (or some static constant expression
3326 involving such literals or a conditional expression
3327 involving such literals) and it is non-negative. */
3328 else if ((op0_signed && tree_expr_nonnegative_p (orig_op0))
3329 || (op1_signed && tree_expr_nonnegative_p (orig_op1)))
3331 /* Do not warn if the comparison is an equality operation,
3332 the unsigned quantity is an integral constant and it does
3333 not use the most significant bit of result_type. */
3334 else if ((resultcode == EQ_EXPR || resultcode == NE_EXPR)
3335 && ((op0_signed && TREE_CODE (orig_op1) == INTEGER_CST
3336 && int_fits_type_p (orig_op1, c_common_signed_type
3338 || (op1_signed && TREE_CODE (orig_op0) == INTEGER_CST
3339 && int_fits_type_p (orig_op0, c_common_signed_type
3343 warning ("comparison between signed and unsigned integer expressions");
3345 /* Warn if two unsigned values are being compared in a size
3346 larger than their original size, and one (and only one) is the
3347 result of a `~' operator. This comparison will always fail.
3349 Also warn if one operand is a constant, and the constant does not
3350 have all bits set that are set in the ~ operand when it is
3353 if ((TREE_CODE (primop0) == BIT_NOT_EXPR)
3354 ^ (TREE_CODE (primop1) == BIT_NOT_EXPR))
3356 if (TREE_CODE (primop0) == BIT_NOT_EXPR)
3357 primop0 = get_narrower (TREE_OPERAND (op0, 0), &unsignedp0);
3358 if (TREE_CODE (primop1) == BIT_NOT_EXPR)
3359 primop1 = get_narrower (TREE_OPERAND (op1, 0), &unsignedp1);
3361 if (host_integerp (primop0, 0) || host_integerp (primop1, 0))
3364 HOST_WIDE_INT constant, mask;
3368 if (host_integerp (primop0, 0))
3371 unsignedp = unsignedp1;
3372 constant = tree_low_cst (primop0, 0);
3377 unsignedp = unsignedp0;
3378 constant = tree_low_cst (primop1, 0);
3381 bits = TYPE_PRECISION (TREE_TYPE (primop));
3382 if (bits < TYPE_PRECISION (result_type)
3383 && bits < HOST_BITS_PER_LONG && unsignedp)
3385 mask = (~ (HOST_WIDE_INT) 0) << bits;
3386 if ((mask & constant) != mask)
3387 warning ("comparison of promoted ~unsigned with constant");
3390 else if (unsignedp0 && unsignedp1
3391 && (TYPE_PRECISION (TREE_TYPE (primop0))
3392 < TYPE_PRECISION (result_type))
3393 && (TYPE_PRECISION (TREE_TYPE (primop1))
3394 < TYPE_PRECISION (result_type)))
3395 warning ("comparison of promoted ~unsigned with unsigned");
3400 /* At this point, RESULT_TYPE must be nonzero to avoid an error message.
3401 If CONVERTED is zero, both args will be converted to type RESULT_TYPE.
3402 Then the expression will be built.
3403 It will be given type FINAL_TYPE if that is nonzero;
3404 otherwise, it will be given type RESULT_TYPE. */
3408 error ("invalid operands of types `%T' and `%T' to binary `%O'",
3409 TREE_TYPE (orig_op0), TREE_TYPE (orig_op1), code);
3410 return error_mark_node;
3413 /* Issue warnings about peculiar, but valid, uses of NULL. */
3414 if (/* It's reasonable to use pointer values as operands of &&
3415 and ||, so NULL is no exception. */
3416 !(code == TRUTH_ANDIF_EXPR || code == TRUTH_ORIF_EXPR)
3417 && (/* If OP0 is NULL and OP1 is not a pointer, or vice versa. */
3418 (orig_op0 == null_node
3419 && TREE_CODE (TREE_TYPE (op1)) != POINTER_TYPE)
3420 /* Or vice versa. */
3421 || (orig_op1 == null_node
3422 && TREE_CODE (TREE_TYPE (op0)) != POINTER_TYPE)
3423 /* Or, both are NULL and the operation was not a comparison. */
3424 || (orig_op0 == null_node && orig_op1 == null_node
3425 && code != EQ_EXPR && code != NE_EXPR)))
3426 /* Some sort of arithmetic operation involving NULL was
3427 performed. Note that pointer-difference and pointer-addition
3428 have already been handled above, and so we don't end up here in
3430 warning ("NULL used in arithmetic");
3434 if (TREE_TYPE (op0) != result_type)
3435 op0 = cp_convert (result_type, op0);
3436 if (TREE_TYPE (op1) != result_type)
3437 op1 = cp_convert (result_type, op1);
3439 if (op0 == error_mark_node || op1 == error_mark_node)
3440 return error_mark_node;
3443 if (build_type == NULL_TREE)
3444 build_type = result_type;
3447 tree result = fold (build2 (resultcode, build_type, op0, op1));
3448 if (final_type != 0)
3449 result = cp_convert (final_type, result);
3454 /* Return a tree for the sum or difference (RESULTCODE says which)
3455 of pointer PTROP and integer INTOP. */
3458 cp_pointer_int_sum (enum tree_code resultcode, tree ptrop, tree intop)
3460 tree res_type = TREE_TYPE (ptrop);
3462 /* pointer_int_sum() uses size_in_bytes() on the TREE_TYPE(res_type)
3463 in certain circumstance (when it's valid to do so). So we need
3464 to make sure it's complete. We don't need to check here, if we
3465 can actually complete it at all, as those checks will be done in
3466 pointer_int_sum() anyway. */
3467 complete_type (TREE_TYPE (res_type));
3469 return pointer_int_sum (resultcode, ptrop, fold (intop));
3472 /* Return a tree for the difference of pointers OP0 and OP1.
3473 The resulting tree has type int. */
3476 pointer_diff (tree op0, tree op1, tree ptrtype)
3479 tree restype = ptrdiff_type_node;
3480 tree target_type = TREE_TYPE (ptrtype);
3482 if (!complete_type_or_else (target_type, NULL_TREE))
3483 return error_mark_node;
3485 if (pedantic || warn_pointer_arith)
3487 if (TREE_CODE (target_type) == VOID_TYPE)
3488 pedwarn ("ISO C++ forbids using pointer of type `void *' in subtraction");
3489 if (TREE_CODE (target_type) == FUNCTION_TYPE)
3490 pedwarn ("ISO C++ forbids using pointer to a function in subtraction");
3491 if (TREE_CODE (target_type) == METHOD_TYPE)
3492 pedwarn ("ISO C++ forbids using pointer to a method in subtraction");
3495 /* First do the subtraction as integers;
3496 then drop through to build the divide operator. */
3498 op0 = cp_build_binary_op (MINUS_EXPR,
3499 cp_convert (restype, op0),
3500 cp_convert (restype, op1));
3502 /* This generates an error if op1 is a pointer to an incomplete type. */
3503 if (!COMPLETE_TYPE_P (TREE_TYPE (TREE_TYPE (op1))))
3504 error ("invalid use of a pointer to an incomplete type in pointer arithmetic");
3506 op1 = (TYPE_PTROB_P (ptrtype)
3507 ? size_in_bytes (target_type)
3508 : integer_one_node);
3510 /* Do the division. */
3512 result = build2 (EXACT_DIV_EXPR, restype, op0, cp_convert (restype, op1));
3513 return fold (result);
3516 /* Construct and perhaps optimize a tree representation
3517 for a unary operation. CODE, a tree_code, specifies the operation
3518 and XARG is the operand. */
3521 build_x_unary_op (enum tree_code code, tree xarg)
3523 tree orig_expr = xarg;
3527 if (processing_template_decl)
3529 if (type_dependent_expression_p (xarg))
3530 return build_min_nt (code, xarg, NULL_TREE);
3532 /* For non-dependent pointer-to-member, the SCOPE_REF will be
3533 processed during template substitution. Just compute the
3534 right type here and build an ADDR_EXPR around it for
3536 if (code == ADDR_EXPR && TREE_CODE (xarg) == SCOPE_REF)
3539 if (TREE_TYPE (xarg) == unknown_type_node)
3540 type = unknown_type_node;
3541 else if (TREE_CODE (TREE_TYPE (xarg)) == FUNCTION_TYPE)
3542 type = build_pointer_type (TREE_TYPE (xarg));
3544 type = build_ptrmem_type (TREE_OPERAND (xarg, 0),
3546 return build_min (code, type, xarg, NULL_TREE);
3549 xarg = build_non_dependent_expr (xarg);
3554 /* [expr.unary.op] says:
3556 The address of an object of incomplete type can be taken.
3558 (And is just the ordinary address operator, not an overloaded
3559 "operator &".) However, if the type is a template
3560 specialization, we must complete the type at this point so that
3561 an overloaded "operator &" will be available if required. */
3562 if (code == ADDR_EXPR
3563 && TREE_CODE (xarg) != TEMPLATE_ID_EXPR
3564 && ((CLASS_TYPE_P (TREE_TYPE (xarg))
3565 && !COMPLETE_TYPE_P (complete_type (TREE_TYPE (xarg))))
3566 || (TREE_CODE (xarg) == OFFSET_REF)))
3567 /* Don't look for a function. */;
3569 exp = build_new_op (code, LOOKUP_NORMAL, xarg, NULL_TREE, NULL_TREE,
3570 /*overloaded_p=*/NULL);
3571 if (!exp && code == ADDR_EXPR)
3573 /* A pointer to member-function can be formed only by saying
3575 if (!flag_ms_extensions && TREE_CODE (TREE_TYPE (xarg)) == METHOD_TYPE
3576 && (TREE_CODE (xarg) != OFFSET_REF || !PTRMEM_OK_P (xarg)))
3578 if (TREE_CODE (xarg) != OFFSET_REF)
3580 error ("invalid use of '%E' to form a pointer-to-member-function. Use a qualified-id.",
3582 return error_mark_node;
3586 error ("parenthesis around '%E' cannot be used to form a pointer-to-member-function",
3588 PTRMEM_OK_P (xarg) = 1;
3592 if (TREE_CODE (xarg) == OFFSET_REF)
3594 ptrmem = PTRMEM_OK_P (xarg);
3596 if (!ptrmem && !flag_ms_extensions
3597 && TREE_CODE (TREE_TYPE (TREE_OPERAND (xarg, 1))) == METHOD_TYPE)
3599 /* A single non-static member, make sure we don't allow a
3600 pointer-to-member. */
3601 xarg = build2 (OFFSET_REF, TREE_TYPE (xarg),
3602 TREE_OPERAND (xarg, 0),
3603 ovl_cons (TREE_OPERAND (xarg, 1), NULL_TREE));
3604 PTRMEM_OK_P (xarg) = ptrmem;
3607 else if (TREE_CODE (xarg) == TARGET_EXPR)
3608 warning ("taking address of temporary");
3609 exp = build_unary_op (ADDR_EXPR, xarg, 0);
3610 if (TREE_CODE (exp) == ADDR_EXPR)
3611 PTRMEM_OK_P (exp) = ptrmem;
3614 if (processing_template_decl && exp != error_mark_node)
3615 return build_min_non_dep (code, exp, orig_expr,
3616 /*For {PRE,POST}{INC,DEC}REMENT_EXPR*/NULL_TREE);
3620 /* Like c_common_truthvalue_conversion, but handle pointer-to-member
3621 constants, where a null value is represented by an INTEGER_CST of
3625 cp_truthvalue_conversion (tree expr)
3627 tree type = TREE_TYPE (expr);
3628 if (TYPE_PTRMEM_P (type))
3629 return build_binary_op (NE_EXPR, expr, integer_zero_node, 1);
3631 return c_common_truthvalue_conversion (expr);
3634 /* Just like cp_truthvalue_conversion, but we want a CLEANUP_POINT_EXPR. */
3637 condition_conversion (tree expr)
3640 if (processing_template_decl)
3642 t = perform_implicit_conversion (boolean_type_node, expr);
3643 t = fold (build1 (CLEANUP_POINT_EXPR, boolean_type_node, t));
3647 /* Return an ADDR_EXPR giving the address of T. This function
3648 attempts no optimizations or simplifications; it is a low-level
3652 build_address (tree t)
3656 if (error_operand_p (t) || !cxx_mark_addressable (t))
3657 return error_mark_node;
3659 addr = build1 (ADDR_EXPR, build_pointer_type (TREE_TYPE (t)), t);
3664 /* Return a NOP_EXPR converting EXPR to TYPE. */
3667 build_nop (tree type, tree expr)
3669 if (type == error_mark_node || error_operand_p (expr))
3671 return build1 (NOP_EXPR, type, expr);
3674 /* C++: Must handle pointers to members.
3676 Perhaps type instantiation should be extended to handle conversion
3677 from aggregates to types we don't yet know we want? (Or are those
3678 cases typically errors which should be reported?)
3680 NOCONVERT nonzero suppresses the default promotions
3681 (such as from short to int). */
3684 build_unary_op (enum tree_code code, tree xarg, int noconvert)
3686 /* No default_conversion here. It causes trouble for ADDR_EXPR. */
3689 const char *errstring = NULL;
3692 if (arg == error_mark_node)
3693 return error_mark_node;
3698 /* This is used for unary plus, because a CONVERT_EXPR
3699 is enough to prevent anybody from looking inside for
3700 associativity, but won't generate any code. */
3701 if (!(arg = build_expr_type_conversion
3702 (WANT_ARITH | WANT_ENUM | WANT_POINTER, arg, true)))
3703 errstring = "wrong type argument to unary plus";
3707 arg = default_conversion (arg);
3708 arg = build1 (NON_LVALUE_EXPR, TREE_TYPE (arg), arg);
3713 if (!(arg = build_expr_type_conversion (WANT_ARITH | WANT_ENUM, arg, true)))
3714 errstring = "wrong type argument to unary minus";
3715 else if (!noconvert && CP_INTEGRAL_TYPE_P (TREE_TYPE (arg)))
3716 arg = perform_integral_promotions (arg);
3720 if (TREE_CODE (TREE_TYPE (arg)) == COMPLEX_TYPE)
3724 arg = default_conversion (arg);
3726 else if (!(arg = build_expr_type_conversion (WANT_INT | WANT_ENUM,
3728 errstring = "wrong type argument to bit-complement";
3729 else if (!noconvert)
3730 arg = perform_integral_promotions (arg);
3734 if (!(arg = build_expr_type_conversion (WANT_ARITH | WANT_ENUM, arg, true)))
3735 errstring = "wrong type argument to abs";
3736 else if (!noconvert)
3737 arg = default_conversion (arg);
3741 /* Conjugating a real value is a no-op, but allow it anyway. */
3742 if (!(arg = build_expr_type_conversion (WANT_ARITH | WANT_ENUM, arg, true)))
3743 errstring = "wrong type argument to conjugation";
3744 else if (!noconvert)
3745 arg = default_conversion (arg);
3748 case TRUTH_NOT_EXPR:
3749 arg = perform_implicit_conversion (boolean_type_node, arg);
3750 val = invert_truthvalue (arg);
3751 if (arg != error_mark_node)
3753 errstring = "in argument to unary !";
3760 if (TREE_CODE (arg) == COMPLEX_CST)
3761 return TREE_REALPART (arg);
3762 else if (TREE_CODE (TREE_TYPE (arg)) == COMPLEX_TYPE)
3763 return fold (build1 (REALPART_EXPR, TREE_TYPE (TREE_TYPE (arg)), arg));
3768 if (TREE_CODE (arg) == COMPLEX_CST)
3769 return TREE_IMAGPART (arg);
3770 else if (TREE_CODE (TREE_TYPE (arg)) == COMPLEX_TYPE)
3771 return fold (build1 (IMAGPART_EXPR, TREE_TYPE (TREE_TYPE (arg)), arg));
3773 return cp_convert (TREE_TYPE (arg), integer_zero_node);
3775 case PREINCREMENT_EXPR:
3776 case POSTINCREMENT_EXPR:
3777 case PREDECREMENT_EXPR:
3778 case POSTDECREMENT_EXPR:
3779 /* Handle complex lvalues (when permitted)
3780 by reduction to simpler cases. */
3782 val = unary_complex_lvalue (code, arg);
3786 /* Increment or decrement the real part of the value,
3787 and don't change the imaginary part. */
3788 if (TREE_CODE (TREE_TYPE (arg)) == COMPLEX_TYPE)
3792 arg = stabilize_reference (arg);
3793 real = build_unary_op (REALPART_EXPR, arg, 1);
3794 imag = build_unary_op (IMAGPART_EXPR, arg, 1);
3795 return build2 (COMPLEX_EXPR, TREE_TYPE (arg),
3796 build_unary_op (code, real, 1), imag);
3799 /* Report invalid types. */
3801 if (!(arg = build_expr_type_conversion (WANT_ARITH | WANT_POINTER,
3804 if (code == PREINCREMENT_EXPR)
3805 errstring ="no pre-increment operator for type";
3806 else if (code == POSTINCREMENT_EXPR)
3807 errstring ="no post-increment operator for type";
3808 else if (code == PREDECREMENT_EXPR)
3809 errstring ="no pre-decrement operator for type";
3811 errstring ="no post-decrement operator for type";
3815 /* Report something read-only. */
3817 if (CP_TYPE_CONST_P (TREE_TYPE (arg))
3818 || TREE_READONLY (arg))
3819 readonly_error (arg, ((code == PREINCREMENT_EXPR
3820 || code == POSTINCREMENT_EXPR)
3821 ? "increment" : "decrement"),
3826 tree result_type = TREE_TYPE (arg);
3828 arg = get_unwidened (arg, 0);
3829 argtype = TREE_TYPE (arg);
3831 /* ARM $5.2.5 last annotation says this should be forbidden. */
3832 if (TREE_CODE (argtype) == ENUMERAL_TYPE)
3833 pedwarn ("ISO C++ forbids %sing an enum",
3834 (code == PREINCREMENT_EXPR || code == POSTINCREMENT_EXPR)
3835 ? "increment" : "decrement");
3837 /* Compute the increment. */
3839 if (TREE_CODE (argtype) == POINTER_TYPE)
3841 tree type = complete_type (TREE_TYPE (argtype));
3843 if (!COMPLETE_OR_VOID_TYPE_P (type))
3844 error ("cannot %s a pointer to incomplete type `%T'",
3845 ((code == PREINCREMENT_EXPR
3846 || code == POSTINCREMENT_EXPR)
3847 ? "increment" : "decrement"), TREE_TYPE (argtype));
3848 else if ((pedantic || warn_pointer_arith)
3849 && !TYPE_PTROB_P (argtype))
3850 pedwarn ("ISO C++ forbids %sing a pointer of type `%T'",
3851 ((code == PREINCREMENT_EXPR
3852 || code == POSTINCREMENT_EXPR)
3853 ? "increment" : "decrement"), argtype);
3854 inc = cxx_sizeof_nowarn (TREE_TYPE (argtype));
3857 inc = integer_one_node;
3859 inc = cp_convert (argtype, inc);
3861 /* Handle incrementing a cast-expression. */
3863 switch (TREE_CODE (arg))
3868 case FIX_TRUNC_EXPR:
3869 case FIX_FLOOR_EXPR:
3870 case FIX_ROUND_EXPR:
3873 tree incremented, modify, value, compound;
3874 if (! lvalue_p (arg) && pedantic)
3875 pedwarn ("cast to non-reference type used as lvalue");
3876 arg = stabilize_reference (arg);
3877 if (code == PREINCREMENT_EXPR || code == PREDECREMENT_EXPR)
3880 value = save_expr (arg);
3881 incremented = build2 (((code == PREINCREMENT_EXPR
3882 || code == POSTINCREMENT_EXPR)
3883 ? PLUS_EXPR : MINUS_EXPR),
3884 argtype, value, inc);
3886 modify = build_modify_expr (arg, NOP_EXPR, incremented);
3887 compound = build2 (COMPOUND_EXPR, TREE_TYPE (arg),
3890 /* Eliminate warning about unused result of + or -. */
3891 TREE_NO_WARNING (compound) = 1;
3899 /* Complain about anything else that is not a true lvalue. */
3900 if (!lvalue_or_else (arg, ((code == PREINCREMENT_EXPR
3901 || code == POSTINCREMENT_EXPR)
3902 ? "increment" : "decrement")))
3903 return error_mark_node;
3905 /* Forbid using -- on `bool'. */
3906 if (TREE_TYPE (arg) == boolean_type_node)
3908 if (code == POSTDECREMENT_EXPR || code == PREDECREMENT_EXPR)
3910 error ("invalid use of `--' on bool variable `%D'", arg);
3911 return error_mark_node;
3913 val = boolean_increment (code, arg);
3916 val = build2 (code, TREE_TYPE (arg), arg, inc);
3918 TREE_SIDE_EFFECTS (val) = 1;
3919 return cp_convert (result_type, val);
3923 /* Note that this operation never does default_conversion
3924 regardless of NOCONVERT. */
3926 argtype = lvalue_type (arg);
3928 if (TREE_CODE (arg) == OFFSET_REF)
3931 if (TREE_CODE (argtype) == REFERENCE_TYPE)
3933 tree type = build_pointer_type (TREE_TYPE (argtype));
3934 arg = build1 (CONVERT_EXPR, type, arg);
3937 else if (pedantic && DECL_MAIN_P (arg))
3939 pedwarn ("ISO C++ forbids taking address of function `::main'");
3941 /* Let &* cancel out to simplify resulting code. */
3942 if (TREE_CODE (arg) == INDIRECT_REF)
3944 /* We don't need to have `current_class_ptr' wrapped in a
3945 NON_LVALUE_EXPR node. */
3946 if (arg == current_class_ref)
3947 return current_class_ptr;
3949 arg = TREE_OPERAND (arg, 0);
3950 if (TREE_CODE (TREE_TYPE (arg)) == REFERENCE_TYPE)
3952 tree type = build_pointer_type (TREE_TYPE (TREE_TYPE (arg)));
3953 arg = build1 (CONVERT_EXPR, type, arg);
3955 else if (lvalue_p (arg))
3956 /* Don't let this be an lvalue. */
3957 return non_lvalue (arg);
3961 /* For &x[y], return x+y. But, in a template, ARG may be an
3962 ARRAY_REF representing a non-dependent expression. In that
3963 case, there may be an overloaded "operator []" that will be
3964 chosen at instantiation time; we must not try to optimize
3966 if (TREE_CODE (arg) == ARRAY_REF && !processing_template_decl)
3968 if (!cxx_mark_addressable (TREE_OPERAND (arg, 0)))
3969 return error_mark_node;
3970 return cp_build_binary_op (PLUS_EXPR, TREE_OPERAND (arg, 0),
3971 TREE_OPERAND (arg, 1));
3974 /* Uninstantiated types are all functions. Taking the
3975 address of a function is a no-op, so just return the
3978 if (TREE_CODE (arg) == IDENTIFIER_NODE
3979 && IDENTIFIER_OPNAME_P (arg))
3982 /* We don't know the type yet, so just work around the problem.
3983 We know that this will resolve to an lvalue. */
3984 return build1 (ADDR_EXPR, unknown_type_node, arg);
3987 if (TREE_CODE (arg) == COMPONENT_REF && type_unknown_p (arg)
3988 && !really_overloaded_fn (TREE_OPERAND (arg, 1)))
3990 /* They're trying to take the address of a unique non-static
3991 member function. This is ill-formed (except in MS-land),
3992 but let's try to DTRT.
3993 Note: We only handle unique functions here because we don't
3994 want to complain if there's a static overload; non-unique
3995 cases will be handled by instantiate_type. But we need to
3996 handle this case here to allow casts on the resulting PMF.
3997 We could defer this in non-MS mode, but it's easier to give
3998 a useful error here. */
4000 /* Inside constant member functions, the `this' pointer
4001 contains an extra const qualifier. TYPE_MAIN_VARIANT
4002 is used here to remove this const from the diagnostics
4003 and the created OFFSET_REF. */
4004 tree base = TYPE_MAIN_VARIANT (TREE_TYPE (TREE_OPERAND (arg, 0)));
4005 tree name = DECL_NAME (get_first_fn (TREE_OPERAND (arg, 1)));
4007 if (! flag_ms_extensions)
4009 if (current_class_type
4010 && TREE_OPERAND (arg, 0) == current_class_ref)
4011 /* An expression like &memfn. */
4012 pedwarn ("ISO C++ forbids taking the address of an unqualified"
4013 " or parenthesized non-static member function to form"
4014 " a pointer to member function. Say `&%T::%D'",
4017 pedwarn ("ISO C++ forbids taking the address of a bound member"
4018 " function to form a pointer to member function."
4022 arg = build_offset_ref (base, name, /*address_p=*/true);
4026 if (type_unknown_p (arg))
4027 return build1 (ADDR_EXPR, unknown_type_node, arg);
4029 /* Handle complex lvalues (when permitted)
4030 by reduction to simpler cases. */
4031 val = unary_complex_lvalue (code, arg);
4035 switch (TREE_CODE (arg))
4040 case FIX_TRUNC_EXPR:
4041 case FIX_FLOOR_EXPR:
4042 case FIX_ROUND_EXPR:
4044 if (! lvalue_p (arg) && pedantic)
4045 pedwarn ("ISO C++ forbids taking the address of a cast to a non-lvalue expression");
4049 arg = OVL_CURRENT (arg);
4056 /* Allow the address of a constructor if all the elements
4058 if (TREE_CODE (arg) == CONSTRUCTOR && TREE_HAS_CONSTRUCTOR (arg)
4059 && TREE_CONSTANT (arg))
4061 /* Anything not already handled and not a true memory reference
4063 else if (TREE_CODE (argtype) != FUNCTION_TYPE
4064 && TREE_CODE (argtype) != METHOD_TYPE
4065 && !lvalue_or_else (arg, "unary `&'"))
4066 return error_mark_node;
4068 if (argtype != error_mark_node)
4069 argtype = build_pointer_type (argtype);
4074 if (TREE_CODE (arg) != COMPONENT_REF
4075 /* Inside a template, we are processing a non-dependent
4076 expression so we can just form an ADDR_EXPR with the
4078 || processing_template_decl)
4079 addr = build_address (arg);
4080 else if (TREE_CODE (TREE_OPERAND (arg, 1)) == BASELINK)
4082 tree fn = BASELINK_FUNCTIONS (TREE_OPERAND (arg, 1));
4084 /* We can only get here with a single static member
4086 gcc_assert (TREE_CODE (fn) == FUNCTION_DECL
4087 && DECL_STATIC_FUNCTION_P (fn));
4089 addr = build_address (fn);
4090 if (TREE_SIDE_EFFECTS (TREE_OPERAND (arg, 0)))
4091 /* Do not lose object's side effects. */
4092 addr = build2 (COMPOUND_EXPR, TREE_TYPE (addr),
4093 TREE_OPERAND (arg, 0), addr);
4095 else if (DECL_C_BIT_FIELD (TREE_OPERAND (arg, 1)))
4097 error ("attempt to take address of bit-field structure member `%D'",
4098 TREE_OPERAND (arg, 1));
4099 return error_mark_node;
4103 /* Unfortunately we cannot just build an address
4104 expression here, because we would not handle
4105 address-constant-expressions or offsetof correctly. */
4106 tree field = TREE_OPERAND (arg, 1);
4107 tree rval = build_unary_op (ADDR_EXPR, TREE_OPERAND (arg, 0), 0);
4108 tree binfo = lookup_base (TREE_TYPE (TREE_TYPE (rval)),
4109 decl_type_context (field),
4112 rval = build_base_path (PLUS_EXPR, rval, binfo, 1);
4113 rval = build_nop (argtype, rval);
4114 addr = fold (build2 (PLUS_EXPR, argtype, rval,
4115 cp_convert (argtype,
4116 byte_position (field))));
4119 if (TREE_CODE (argtype) == POINTER_TYPE
4120 && TREE_CODE (TREE_TYPE (argtype)) == METHOD_TYPE)
4122 build_ptrmemfunc_type (argtype);
4123 addr = build_ptrmemfunc (argtype, addr, 0);
4136 argtype = TREE_TYPE (arg);
4137 return fold (build1 (code, argtype, arg));
4140 error ("%s", errstring);
4141 return error_mark_node;
4144 /* Apply unary lvalue-demanding operator CODE to the expression ARG
4145 for certain kinds of expressions which are not really lvalues
4146 but which we can accept as lvalues.
4148 If ARG is not a kind of expression we can handle, return zero. */
4151 unary_complex_lvalue (enum tree_code code, tree arg)
4153 /* Handle (a, b) used as an "lvalue". */
4154 if (TREE_CODE (arg) == COMPOUND_EXPR)
4156 tree real_result = build_unary_op (code, TREE_OPERAND (arg, 1), 0);
4157 return build2 (COMPOUND_EXPR, TREE_TYPE (real_result),
4158 TREE_OPERAND (arg, 0), real_result);
4161 /* Handle (a ? b : c) used as an "lvalue". */
4162 if (TREE_CODE (arg) == COND_EXPR
4163 || TREE_CODE (arg) == MIN_EXPR || TREE_CODE (arg) == MAX_EXPR)
4164 return rationalize_conditional_expr (code, arg);
4166 /* Handle (a = b), (++a), and (--a) used as an "lvalue". */
4167 if (TREE_CODE (arg) == MODIFY_EXPR
4168 || TREE_CODE (arg) == PREINCREMENT_EXPR
4169 || TREE_CODE (arg) == PREDECREMENT_EXPR)
4171 tree lvalue = TREE_OPERAND (arg, 0);
4172 if (TREE_SIDE_EFFECTS (lvalue))
4174 lvalue = stabilize_reference (lvalue);
4175 arg = build2 (TREE_CODE (arg), TREE_TYPE (arg),
4176 lvalue, TREE_OPERAND (arg, 1));
4178 return unary_complex_lvalue
4179 (code, build2 (COMPOUND_EXPR, TREE_TYPE (lvalue), arg, lvalue));
4182 if (code != ADDR_EXPR)
4185 /* Handle (a = b) used as an "lvalue" for `&'. */
4186 if (TREE_CODE (arg) == MODIFY_EXPR
4187 || TREE_CODE (arg) == INIT_EXPR)
4189 tree real_result = build_unary_op (code, TREE_OPERAND (arg, 0), 0);
4190 arg = build2 (COMPOUND_EXPR, TREE_TYPE (real_result),
4192 TREE_NO_WARNING (arg) = 1;
4196 if (TREE_CODE (TREE_TYPE (arg)) == FUNCTION_TYPE
4197 || TREE_CODE (TREE_TYPE (arg)) == METHOD_TYPE
4198 || TREE_CODE (arg) == OFFSET_REF)
4202 gcc_assert (TREE_CODE (arg) != SCOPE_REF);
4204 if (TREE_CODE (arg) != OFFSET_REF)
4207 t = TREE_OPERAND (arg, 1);
4209 /* Check all this code for right semantics. */
4210 if (TREE_CODE (t) == FUNCTION_DECL)
4212 if (DECL_DESTRUCTOR_P (t))
4213 error ("taking address of destructor");
4214 return build_unary_op (ADDR_EXPR, t, 0);
4216 if (TREE_CODE (t) == VAR_DECL)
4217 return build_unary_op (ADDR_EXPR, t, 0);
4222 if (TREE_OPERAND (arg, 0)
4223 && ! is_dummy_object (TREE_OPERAND (arg, 0))
4224 && TREE_CODE (t) != FIELD_DECL)
4226 error ("taking address of bound pointer-to-member expression");
4227 return error_mark_node;
4229 if (!PTRMEM_OK_P (arg))
4230 return build_unary_op (code, arg, 0);
4232 if (TREE_CODE (TREE_TYPE (t)) == REFERENCE_TYPE)
4234 error ("cannot create pointer to reference member `%D'", t);
4235 return error_mark_node;
4238 type = build_ptrmem_type (context_for_name_lookup (t),
4240 t = make_ptrmem_cst (type, TREE_OPERAND (arg, 1));
4246 /* We permit compiler to make function calls returning
4247 objects of aggregate type look like lvalues. */
4251 if (TREE_CODE (targ) == SAVE_EXPR)
4252 targ = TREE_OPERAND (targ, 0);
4254 if (TREE_CODE (targ) == CALL_EXPR && IS_AGGR_TYPE (TREE_TYPE (targ)))
4256 if (TREE_CODE (arg) == SAVE_EXPR)
4259 targ = build_cplus_new (TREE_TYPE (arg), arg);
4260 return build1 (ADDR_EXPR, build_pointer_type (TREE_TYPE (arg)), targ);
4263 if (TREE_CODE (arg) == SAVE_EXPR && TREE_CODE (targ) == INDIRECT_REF)
4264 return build3 (SAVE_EXPR, build_pointer_type (TREE_TYPE (arg)),
4265 TREE_OPERAND (targ, 0), current_function_decl, NULL);
4268 /* Don't let anything else be handled specially. */
4272 /* Mark EXP saying that we need to be able to take the
4273 address of it; it should not be allocated in a register.
4274 Value is true if successful.
4276 C++: we do not allow `current_class_ptr' to be addressable. */
4279 cxx_mark_addressable (tree exp)
4284 switch (TREE_CODE (x))
4291 x = TREE_OPERAND (x, 0);
4295 if (x == current_class_ptr)
4297 error ("cannot take the address of `this', which is an rvalue expression");
4298 TREE_ADDRESSABLE (x) = 1; /* so compiler doesn't die later. */
4304 /* Caller should not be trying to mark initialized
4305 constant fields addressable. */
4306 gcc_assert (DECL_LANG_SPECIFIC (x) == 0
4307 || DECL_IN_AGGR_P (x) == 0
4309 || DECL_EXTERNAL (x));
4314 if (DECL_REGISTER (x) && !TREE_ADDRESSABLE (x)
4315 && !DECL_ARTIFICIAL (x) && extra_warnings)
4316 warning ("address requested for `%D', which is declared `register'",
4318 TREE_ADDRESSABLE (x) = 1;
4322 TREE_ADDRESSABLE (x) = 1;
4326 TREE_ADDRESSABLE (x) = 1;
4330 TREE_ADDRESSABLE (x) = 1;
4331 cxx_mark_addressable (TREE_OPERAND (x, 0));
4339 /* Build and return a conditional expression IFEXP ? OP1 : OP2. */
4342 build_x_conditional_expr (tree ifexp, tree op1, tree op2)
4344 tree orig_ifexp = ifexp;
4345 tree orig_op1 = op1;
4346 tree orig_op2 = op2;
4349 if (processing_template_decl)
4351 /* The standard says that the expression is type-dependent if
4352 IFEXP is type-dependent, even though the eventual type of the
4353 expression doesn't dependent on IFEXP. */
4354 if (type_dependent_expression_p (ifexp)
4355 /* As a GNU extension, the middle operand may be omitted. */
4356 || (op1 && type_dependent_expression_p (op1))
4357 || type_dependent_expression_p (op2))
4358 return build_min_nt (COND_EXPR, ifexp, op1, op2);
4359 ifexp = build_non_dependent_expr (ifexp);
4361 op1 = build_non_dependent_expr (op1);
4362 op2 = build_non_dependent_expr (op2);
4365 expr = build_conditional_expr (ifexp, op1, op2);
4366 if (processing_template_decl && expr != error_mark_node)
4367 return build_min_non_dep (COND_EXPR, expr,
4368 orig_ifexp, orig_op1, orig_op2);
4372 /* Given a list of expressions, return a compound expression
4373 that performs them all and returns the value of the last of them. */
4375 tree build_x_compound_expr_from_list (tree list, const char *msg)
4377 tree expr = TREE_VALUE (list);
4379 if (TREE_CHAIN (list))
4382 pedwarn ("%s expression list treated as compound expression", msg);
4384 for (list = TREE_CHAIN (list); list; list = TREE_CHAIN (list))
4385 expr = build_x_compound_expr (expr, TREE_VALUE (list));
4391 /* Handle overloading of the ',' operator when needed. */
4394 build_x_compound_expr (tree op1, tree op2)
4397 tree orig_op1 = op1;
4398 tree orig_op2 = op2;
4400 if (processing_template_decl)
4402 if (type_dependent_expression_p (op1)
4403 || type_dependent_expression_p (op2))
4404 return build_min_nt (COMPOUND_EXPR, op1, op2);
4405 op1 = build_non_dependent_expr (op1);
4406 op2 = build_non_dependent_expr (op2);
4409 result = build_new_op (COMPOUND_EXPR, LOOKUP_NORMAL, op1, op2, NULL_TREE,
4410 /*overloaded_p=*/NULL);
4412 result = build_compound_expr (op1, op2);
4414 if (processing_template_decl && result != error_mark_node)
4415 return build_min_non_dep (COMPOUND_EXPR, result, orig_op1, orig_op2);
4420 /* Build a compound expression. */
4423 build_compound_expr (tree lhs, tree rhs)
4425 lhs = decl_constant_value (lhs);
4426 lhs = convert_to_void (lhs, "left-hand operand of comma");
4428 if (lhs == error_mark_node || rhs == error_mark_node)
4429 return error_mark_node;
4431 if (TREE_CODE (rhs) == TARGET_EXPR)
4433 /* If the rhs is a TARGET_EXPR, then build the compound
4434 expression inside the target_expr's initializer. This
4435 helps the compiler to eliminate unnecessary temporaries. */
4436 tree init = TREE_OPERAND (rhs, 1);
4438 init = build2 (COMPOUND_EXPR, TREE_TYPE (init), lhs, init);
4439 TREE_OPERAND (rhs, 1) = init;
4444 return build2 (COMPOUND_EXPR, TREE_TYPE (rhs), lhs, rhs);
4447 /* Issue an error message if casting from SRC_TYPE to DEST_TYPE casts
4448 away constness. DESCRIPTION explains what operation is taking
4452 check_for_casting_away_constness (tree src_type, tree dest_type,
4453 const char *description)
4455 if (casts_away_constness (src_type, dest_type))
4456 error ("%s from type `%T' to type `%T' casts away constness",
4457 description, src_type, dest_type);
4460 /* Return an expression representing static_cast<TYPE>(EXPR). */
4463 build_static_cast (tree type, tree expr)
4468 if (type == error_mark_node || expr == error_mark_node)
4469 return error_mark_node;
4471 if (processing_template_decl)
4473 expr = build_min (STATIC_CAST_EXPR, type, expr);
4474 /* We don't know if it will or will not have side effects. */
4475 TREE_SIDE_EFFECTS (expr) = 1;
4479 /* build_c_cast puts on a NOP_EXPR to make the result not an lvalue.
4480 Strip such NOP_EXPRs if VALUE is being used in non-lvalue context. */
4481 if (TREE_CODE (type) != REFERENCE_TYPE
4482 && TREE_CODE (expr) == NOP_EXPR
4483 && TREE_TYPE (expr) == TREE_TYPE (TREE_OPERAND (expr, 0)))
4484 expr = TREE_OPERAND (expr, 0);
4486 intype = TREE_TYPE (expr);
4488 /* [expr.static.cast]
4490 An lvalue of type "cv1 B", where B is a class type, can be cast
4491 to type "reference to cv2 D", where D is a class derived (clause
4492 _class.derived_) from B, if a valid standard conversion from
4493 "pointer to D" to "pointer to B" exists (_conv.ptr_), cv2 is the
4494 same cv-qualification as, or greater cv-qualification than, cv1,
4495 and B is not a virtual base class of D. */
4496 /* We check this case before checking the validity of "TYPE t =
4497 EXPR;" below because for this case:
4500 struct D : public B { D(const B&); };
4502 void f() { static_cast<const D&>(b); }
4504 we want to avoid constructing a new D. The standard is not
4505 completely clear about this issue, but our interpretation is
4506 consistent with other compilers. */
4507 if (TREE_CODE (type) == REFERENCE_TYPE
4508 && CLASS_TYPE_P (TREE_TYPE (type))
4509 && CLASS_TYPE_P (intype)
4510 && real_lvalue_p (expr)
4511 && DERIVED_FROM_P (intype, TREE_TYPE (type))
4512 && can_convert (build_pointer_type (TYPE_MAIN_VARIANT (intype)),
4513 build_pointer_type (TYPE_MAIN_VARIANT
4514 (TREE_TYPE (type))))
4515 && at_least_as_qualified_p (TREE_TYPE (type), intype))
4517 /* There is a standard conversion from "D*" to "B*" even if "B"
4518 is ambiguous or inaccessible. Therefore, we ask lookup_base
4519 to check these conditions. */
4520 tree base = lookup_base (TREE_TYPE (type), intype, ba_check, NULL);
4522 /* Convert from "B*" to "D*". This function will check that "B"
4523 is not a virtual base of "D". */
4524 expr = build_base_path (MINUS_EXPR, build_address (expr),
4525 base, /*nonnull=*/false);
4526 /* Convert the pointer to a reference -- but then remember that
4527 there are no expressions with reference type in C++. */
4528 return convert_from_reference (build_nop (type, expr));
4531 /* [expr.static.cast]
4533 An expression e can be explicitly converted to a type T using a
4534 static_cast of the form static_cast<T>(e) if the declaration T
4535 t(e);" is well-formed, for some invented temporary variable
4537 result = perform_direct_initialization_if_possible (type, expr);
4540 result = convert_from_reference (result);
4541 /* [expr.static.cast]
4543 If T is a reference type, the result is an lvalue; otherwise,
4544 the result is an rvalue. */
4545 if (TREE_CODE (type) != REFERENCE_TYPE
4546 && real_lvalue_p (result))
4547 result = build1 (NON_LVALUE_EXPR, TREE_TYPE (result), result);
4551 /* [expr.static.cast]
4553 Any expression can be explicitly converted to type cv void. */
4554 if (TREE_CODE (type) == VOID_TYPE)
4555 return convert_to_void (expr, /*implicit=*/NULL);
4557 /* [expr.static.cast]
4559 The inverse of any standard conversion sequence (clause _conv_),
4560 other than the lvalue-to-rvalue (_conv.lval_), array-to-pointer
4561 (_conv.array_), function-to-pointer (_conv.func_), and boolean
4562 (_conv.bool_) conversions, can be performed explicitly using
4563 static_cast subject to the restriction that the explicit
4564 conversion does not cast away constness (_expr.const.cast_), and
4565 the following additional rules for specific cases: */
4566 /* For reference, the conversions not excluded are: integral
4567 promotions, floating point promotion, integral conversions,
4568 floating point conversions, floating-integral conversions,
4569 pointer conversions, and pointer to member conversions. */
4570 if ((ARITHMETIC_TYPE_P (type) && ARITHMETIC_TYPE_P (intype))
4573 A value of integral _or enumeration_ type can be explicitly
4574 converted to an enumeration type. */
4575 || (INTEGRAL_OR_ENUMERATION_TYPE_P (type)
4576 && INTEGRAL_OR_ENUMERATION_TYPE_P (intype)))
4577 /* Really, build_c_cast should defer to this function rather
4578 than the other way around. */
4579 return build_c_cast (type, expr);
4581 if (TYPE_PTR_P (type) && TYPE_PTR_P (intype)
4582 && CLASS_TYPE_P (TREE_TYPE (type))
4583 && CLASS_TYPE_P (TREE_TYPE (intype))
4584 && can_convert (build_pointer_type (TYPE_MAIN_VARIANT
4585 (TREE_TYPE (intype))),
4586 build_pointer_type (TYPE_MAIN_VARIANT
4587 (TREE_TYPE (type)))))
4591 check_for_casting_away_constness (intype, type, "static_cast");
4592 base = lookup_base (TREE_TYPE (type), TREE_TYPE (intype), ba_check,
4594 return build_base_path (MINUS_EXPR, expr, base, /*nonnull=*/false);
4597 if ((TYPE_PTRMEM_P (type) && TYPE_PTRMEM_P (intype))
4598 || (TYPE_PTRMEMFUNC_P (type) && TYPE_PTRMEMFUNC_P (intype)))
4605 c1 = TYPE_PTRMEM_CLASS_TYPE (intype);
4606 c2 = TYPE_PTRMEM_CLASS_TYPE (type);
4608 if (TYPE_PTRMEM_P (type))
4610 t1 = (build_ptrmem_type
4612 TYPE_MAIN_VARIANT (TYPE_PTRMEM_POINTED_TO_TYPE (intype))));
4613 t2 = (build_ptrmem_type
4615 TYPE_MAIN_VARIANT (TYPE_PTRMEM_POINTED_TO_TYPE (type))));
4622 if (can_convert (t1, t2))
4624 check_for_casting_away_constness (intype, type, "static_cast");
4625 if (TYPE_PTRMEM_P (type))
4629 if (TREE_CODE (expr) == PTRMEM_CST)
4630 expr = cplus_expand_constant (expr);
4631 delta = get_delta_difference (c1, c2, /*force=*/1);
4632 if (!integer_zerop (delta))
4633 expr = cp_build_binary_op (PLUS_EXPR,
4634 build_nop (ptrdiff_type_node, expr),
4636 return build_nop (type, expr);
4639 return build_ptrmemfunc (TYPE_PTRMEMFUNC_FN_TYPE (type), expr,
4644 /* [expr.static.cast]
4646 An rvalue of type "pointer to cv void" can be explicitly
4647 converted to a pointer to object type. A value of type pointer
4648 to object converted to "pointer to cv void" and back to the
4649 original pointer type will have its original value. */
4650 if (TREE_CODE (intype) == POINTER_TYPE
4651 && VOID_TYPE_P (TREE_TYPE (intype))
4652 && TYPE_PTROB_P (type))
4654 check_for_casting_away_constness (intype, type, "static_cast");
4655 return build_nop (type, expr);
4658 error ("invalid static_cast from type `%T' to type `%T'", intype, type);
4659 return error_mark_node;
4663 build_reinterpret_cast (tree type, tree expr)
4667 if (type == error_mark_node || expr == error_mark_node)
4668 return error_mark_node;
4670 if (processing_template_decl)
4672 tree t = build_min (REINTERPRET_CAST_EXPR, type, expr);
4674 if (!TREE_SIDE_EFFECTS (t)
4675 && type_dependent_expression_p (expr))
4676 /* There might turn out to be side effects inside expr. */
4677 TREE_SIDE_EFFECTS (t) = 1;
4681 if (TREE_CODE (type) != REFERENCE_TYPE)
4683 expr = decay_conversion (expr);
4685 /* build_c_cast puts on a NOP_EXPR to make the result not an lvalue.
4686 Strip such NOP_EXPRs if VALUE is being used in non-lvalue context. */
4687 if (TREE_CODE (expr) == NOP_EXPR
4688 && TREE_TYPE (expr) == TREE_TYPE (TREE_OPERAND (expr, 0)))
4689 expr = TREE_OPERAND (expr, 0);
4692 intype = TREE_TYPE (expr);
4694 if (TREE_CODE (type) == REFERENCE_TYPE)
4696 if (! real_lvalue_p (expr))
4698 error ("invalid reinterpret_cast of an rvalue expression of type `%T' to type `%T'", intype, type);
4699 return error_mark_node;
4701 expr = build_unary_op (ADDR_EXPR, expr, 0);
4702 if (expr != error_mark_node)
4703 expr = build_reinterpret_cast
4704 (build_pointer_type (TREE_TYPE (type)), expr);
4705 if (expr != error_mark_node)
4706 expr = build_indirect_ref (expr, 0);
4709 else if (same_type_ignoring_top_level_qualifiers_p (intype, type))
4710 return build_static_cast (type, expr);
4712 if (TYPE_PTR_P (type) && (TREE_CODE (intype) == INTEGER_TYPE
4713 || TREE_CODE (intype) == ENUMERAL_TYPE))
4715 else if (TREE_CODE (type) == INTEGER_TYPE && TYPE_PTR_P (intype))
4717 if (TYPE_PRECISION (type) < TYPE_PRECISION (intype))
4718 pedwarn ("reinterpret_cast from `%T' to `%T' loses precision",
4721 else if ((TYPE_PTRFN_P (type) && TYPE_PTRFN_P (intype))
4722 || (TYPE_PTRMEMFUNC_P (type) && TYPE_PTRMEMFUNC_P (intype)))
4724 expr = decl_constant_value (expr);
4725 return fold (build1 (NOP_EXPR, type, expr));
4727 else if ((TYPE_PTRMEM_P (type) && TYPE_PTRMEM_P (intype))
4728 || (TYPE_PTROBV_P (type) && TYPE_PTROBV_P (intype)))
4730 check_for_casting_away_constness (intype, type, "reinterpret_cast");
4731 expr = decl_constant_value (expr);
4732 return fold (build1 (NOP_EXPR, type, expr));
4734 else if ((TYPE_PTRFN_P (type) && TYPE_PTROBV_P (intype))
4735 || (TYPE_PTRFN_P (intype) && TYPE_PTROBV_P (type)))
4737 pedwarn ("ISO C++ forbids casting between pointer-to-function and pointer-to-object");
4738 expr = decl_constant_value (expr);
4739 return fold (build1 (NOP_EXPR, type, expr));
4743 error ("invalid reinterpret_cast from type `%T' to type `%T'",
4745 return error_mark_node;
4748 return cp_convert (type, expr);
4752 build_const_cast (tree type, tree expr)
4756 if (type == error_mark_node || expr == error_mark_node)
4757 return error_mark_node;
4759 if (processing_template_decl)
4761 tree t = build_min (CONST_CAST_EXPR, type, expr);
4763 if (!TREE_SIDE_EFFECTS (t)
4764 && type_dependent_expression_p (expr))
4765 /* There might turn out to be side effects inside expr. */
4766 TREE_SIDE_EFFECTS (t) = 1;
4770 if (!POINTER_TYPE_P (type) && !TYPE_PTRMEM_P (type))
4771 error ("invalid use of const_cast with type `%T', which is not a pointer, reference, nor a pointer-to-data-member type", type);
4772 else if (TREE_CODE (TREE_TYPE (type)) == FUNCTION_TYPE)
4774 error ("invalid use of const_cast with type `%T', which is a pointer or reference to a function type", type);
4775 return error_mark_node;
4778 if (TREE_CODE (type) != REFERENCE_TYPE)
4780 expr = decay_conversion (expr);
4782 /* build_c_cast puts on a NOP_EXPR to make the result not an lvalue.
4783 Strip such NOP_EXPRs if VALUE is being used in non-lvalue context. */
4784 if (TREE_CODE (expr) == NOP_EXPR
4785 && TREE_TYPE (expr) == TREE_TYPE (TREE_OPERAND (expr, 0)))
4786 expr = TREE_OPERAND (expr, 0);
4789 intype = TREE_TYPE (expr);
4791 if (same_type_ignoring_top_level_qualifiers_p (intype, type))
4792 return build_static_cast (type, expr);
4793 else if (TREE_CODE (type) == REFERENCE_TYPE)
4795 if (! real_lvalue_p (expr))
4797 error ("invalid const_cast of an rvalue of type `%T' to type `%T'", intype, type);
4798 return error_mark_node;
4801 if (comp_ptr_ttypes_const (TREE_TYPE (type), intype))
4803 expr = build_unary_op (ADDR_EXPR, expr, 0);
4804 expr = build1 (NOP_EXPR, type, expr);
4805 return convert_from_reference (expr);
4808 else if (((TREE_CODE (type) == POINTER_TYPE
4809 && TREE_CODE (intype) == POINTER_TYPE)
4810 || (TYPE_PTRMEM_P (type) && TYPE_PTRMEM_P (intype)))
4811 && comp_ptr_ttypes_const (TREE_TYPE (type), TREE_TYPE (intype)))
4812 return cp_convert (type, expr);
4814 error ("invalid const_cast from type `%T' to type `%T'", intype, type);
4815 return error_mark_node;
4818 /* Build an expression representing a cast to type TYPE of expression EXPR.
4820 ALLOW_NONCONVERTING is true if we should allow non-converting constructors
4821 when doing the cast. */
4824 build_c_cast (tree type, tree expr)
4829 if (type == error_mark_node || expr == error_mark_node)
4830 return error_mark_node;
4832 if (processing_template_decl)
4834 tree t = build_min (CAST_EXPR, type,
4835 tree_cons (NULL_TREE, value, NULL_TREE));
4836 /* We don't know if it will or will not have side effects. */
4837 TREE_SIDE_EFFECTS (t) = 1;
4841 /* build_c_cast puts on a NOP_EXPR to make the result not an lvalue.
4842 Strip such NOP_EXPRs if VALUE is being used in non-lvalue context. */
4843 if (TREE_CODE (type) != REFERENCE_TYPE
4844 && TREE_CODE (value) == NOP_EXPR
4845 && TREE_TYPE (value) == TREE_TYPE (TREE_OPERAND (value, 0)))
4846 value = TREE_OPERAND (value, 0);
4848 if (TREE_CODE (type) == ARRAY_TYPE)
4850 /* Allow casting from T1* to T2[] because Cfront allows it.
4851 NIHCL uses it. It is not valid ISO C++ however. */
4852 if (TREE_CODE (TREE_TYPE (expr)) == POINTER_TYPE)
4854 pedwarn ("ISO C++ forbids casting to an array type `%T'", type);
4855 type = build_pointer_type (TREE_TYPE (type));
4859 error ("ISO C++ forbids casting to an array type `%T'", type);
4860 return error_mark_node;
4864 if (TREE_CODE (type) == FUNCTION_TYPE
4865 || TREE_CODE (type) == METHOD_TYPE)
4867 error ("invalid cast to function type `%T'", type);
4868 return error_mark_node;
4871 if (TREE_CODE (type) == VOID_TYPE)
4873 /* Conversion to void does not cause any of the normal function to
4874 * pointer, array to pointer and lvalue to rvalue decays. */
4876 value = convert_to_void (value, /*implicit=*/NULL);
4880 if (!complete_type_or_else (type, NULL_TREE))
4881 return error_mark_node;
4883 /* Convert functions and arrays to pointers and
4884 convert references to their expanded types,
4885 but don't convert any other types. If, however, we are
4886 casting to a class type, there's no reason to do this: the
4887 cast will only succeed if there is a converting constructor,
4888 and the default conversions will be done at that point. In
4889 fact, doing the default conversion here is actually harmful
4893 struct S { S(const A&); };
4895 since we don't want the array-to-pointer conversion done. */
4896 if (!IS_AGGR_TYPE (type))
4898 if (TREE_CODE (TREE_TYPE (value)) == FUNCTION_TYPE
4899 || (TREE_CODE (TREE_TYPE (value)) == METHOD_TYPE
4900 /* Don't do the default conversion on a ->* expression. */
4901 && ! (TREE_CODE (type) == POINTER_TYPE
4902 && bound_pmf_p (value)))
4903 || TREE_CODE (TREE_TYPE (value)) == ARRAY_TYPE
4904 || TREE_CODE (TREE_TYPE (value)) == REFERENCE_TYPE)
4905 value = decay_conversion (value);
4907 else if (TREE_CODE (TREE_TYPE (value)) == REFERENCE_TYPE)
4908 /* However, even for class types, we still need to strip away
4909 the reference type, since the call to convert_force below
4910 does not expect the input expression to be of reference
4912 value = convert_from_reference (value);
4914 otype = TREE_TYPE (value);
4916 /* Optionally warn about potentially worrisome casts. */
4919 && TREE_CODE (type) == POINTER_TYPE
4920 && TREE_CODE (otype) == POINTER_TYPE
4921 && !at_least_as_qualified_p (TREE_TYPE (type),
4923 warning ("cast from `%T' to `%T' discards qualifiers from pointer target type",
4926 if (TREE_CODE (type) == INTEGER_TYPE
4927 && TYPE_PTR_P (otype)
4928 && TYPE_PRECISION (type) != TYPE_PRECISION (otype))
4929 warning ("cast from pointer to integer of different size");
4931 if (TYPE_PTR_P (type)
4932 && TREE_CODE (otype) == INTEGER_TYPE
4933 && TYPE_PRECISION (type) != TYPE_PRECISION (otype)
4934 /* Don't warn about converting any constant. */
4935 && !TREE_CONSTANT (value))
4936 warning ("cast to pointer from integer of different size");
4938 if (TREE_CODE (type) == REFERENCE_TYPE)
4939 value = (convert_from_reference
4940 (convert_to_reference (type, value, CONV_C_CAST,
4941 LOOKUP_COMPLAIN, NULL_TREE)));
4946 value = decl_constant_value (value);
4949 value = convert_force (type, value, CONV_C_CAST);
4951 /* Ignore any integer overflow caused by the cast. */
4952 if (TREE_CODE (value) == INTEGER_CST)
4954 TREE_OVERFLOW (value) = TREE_OVERFLOW (ovalue);
4956 if (TREE_CODE_CLASS (TREE_CODE (ovalue)) == 'c')
4957 TREE_CONSTANT_OVERFLOW (value) = TREE_CONSTANT_OVERFLOW (ovalue);
4961 /* Warn about possible alignment problems. Do this here when we will have
4962 instantiated any necessary template types. */
4963 if (STRICT_ALIGNMENT && warn_cast_align
4964 && TREE_CODE (type) == POINTER_TYPE
4965 && TREE_CODE (otype) == POINTER_TYPE
4966 && TREE_CODE (TREE_TYPE (otype)) != VOID_TYPE
4967 && TREE_CODE (TREE_TYPE (otype)) != FUNCTION_TYPE
4968 && COMPLETE_TYPE_P (TREE_TYPE (otype))
4969 && COMPLETE_TYPE_P (TREE_TYPE (type))
4970 && TYPE_ALIGN (TREE_TYPE (type)) > TYPE_ALIGN (TREE_TYPE (otype)))
4971 warning ("cast from `%T' to `%T' increases required alignment of target type",
4974 /* Always produce some operator for an explicit cast,
4975 so we can tell (for -pedantic) that the cast is no lvalue. */
4976 if (TREE_CODE (type) != REFERENCE_TYPE && value == expr
4977 && real_lvalue_p (value))
4978 value = non_lvalue (value);
4983 /* Build an assignment expression of lvalue LHS from value RHS.
4984 MODIFYCODE is the code for a binary operator that we use
4985 to combine the old value of LHS with RHS to get the new value.
4986 Or else MODIFYCODE is NOP_EXPR meaning do a simple assignment.
4988 C++: If MODIFYCODE is INIT_EXPR, then leave references unbashed. */
4991 build_modify_expr (tree lhs, enum tree_code modifycode, tree rhs)
4995 tree lhstype = TREE_TYPE (lhs);
4996 tree olhstype = lhstype;
4997 tree olhs = NULL_TREE;
4998 bool plain_assign = (modifycode == NOP_EXPR);
5000 /* Avoid duplicate error messages from operands that had errors. */
5001 if (lhs == error_mark_node || rhs == error_mark_node)
5002 return error_mark_node;
5004 /* Handle control structure constructs used as "lvalues". */
5005 switch (TREE_CODE (lhs))
5007 /* Handle --foo = 5; as these are valid constructs in C++. */
5008 case PREDECREMENT_EXPR:
5009 case PREINCREMENT_EXPR:
5010 if (TREE_SIDE_EFFECTS (TREE_OPERAND (lhs, 0)))
5011 lhs = build2 (TREE_CODE (lhs), TREE_TYPE (lhs),
5012 stabilize_reference (TREE_OPERAND (lhs, 0)),
5013 TREE_OPERAND (lhs, 1));
5014 return build2 (COMPOUND_EXPR, lhstype,
5016 build_modify_expr (TREE_OPERAND (lhs, 0),
5019 /* Handle (a, b) used as an "lvalue". */
5021 newrhs = build_modify_expr (TREE_OPERAND (lhs, 1),
5023 if (newrhs == error_mark_node)
5024 return error_mark_node;
5025 return build2 (COMPOUND_EXPR, lhstype,
5026 TREE_OPERAND (lhs, 0), newrhs);
5029 if (TREE_SIDE_EFFECTS (TREE_OPERAND (lhs, 0)))
5030 lhs = build2 (TREE_CODE (lhs), TREE_TYPE (lhs),
5031 stabilize_reference (TREE_OPERAND (lhs, 0)),
5032 TREE_OPERAND (lhs, 1));
5033 newrhs = build_modify_expr (TREE_OPERAND (lhs, 0), modifycode, rhs);
5034 if (newrhs == error_mark_node)
5035 return error_mark_node;
5036 return build2 (COMPOUND_EXPR, lhstype, lhs, newrhs);
5038 /* Handle (a ? b : c) used as an "lvalue". */
5041 /* Produce (a ? (b = rhs) : (c = rhs))
5042 except that the RHS goes through a save-expr
5043 so the code to compute it is only emitted once. */
5045 tree preeval = NULL_TREE;
5047 rhs = stabilize_expr (rhs, &preeval);
5049 /* Check this here to avoid odd errors when trying to convert
5050 a throw to the type of the COND_EXPR. */
5051 if (!lvalue_or_else (lhs, "assignment"))
5052 return error_mark_node;
5054 cond = build_conditional_expr
5055 (TREE_OPERAND (lhs, 0),
5056 build_modify_expr (cp_convert (TREE_TYPE (lhs),
5057 TREE_OPERAND (lhs, 1)),
5059 build_modify_expr (cp_convert (TREE_TYPE (lhs),
5060 TREE_OPERAND (lhs, 2)),
5063 if (cond == error_mark_node)
5065 /* Make sure the code to compute the rhs comes out
5066 before the split. */
5068 cond = build2 (COMPOUND_EXPR, TREE_TYPE (lhs), preeval, cond);
5076 if (modifycode == INIT_EXPR)
5078 if (TREE_CODE (rhs) == CONSTRUCTOR)
5080 if (! same_type_p (TREE_TYPE (rhs), lhstype))
5081 /* Call convert to generate an error; see PR 11063. */
5082 rhs = convert (lhstype, rhs);
5083 result = build2 (INIT_EXPR, lhstype, lhs, rhs);
5084 TREE_SIDE_EFFECTS (result) = 1;
5087 else if (! IS_AGGR_TYPE (lhstype))
5088 /* Do the default thing. */;
5091 result = build_special_member_call (lhs, complete_ctor_identifier,
5092 build_tree_list (NULL_TREE, rhs),
5093 lhstype, LOOKUP_NORMAL);
5094 if (result == NULL_TREE)
5095 return error_mark_node;
5101 if (TREE_CODE (lhstype) == REFERENCE_TYPE)
5103 lhs = convert_from_reference (lhs);
5104 olhstype = lhstype = TREE_TYPE (lhs);
5106 lhs = require_complete_type (lhs);
5107 if (lhs == error_mark_node)
5108 return error_mark_node;
5110 if (modifycode == NOP_EXPR)
5112 /* `operator=' is not an inheritable operator. */
5113 if (! IS_AGGR_TYPE (lhstype))
5114 /* Do the default thing. */;
5117 result = build_new_op (MODIFY_EXPR, LOOKUP_NORMAL,
5118 lhs, rhs, make_node (NOP_EXPR),
5119 /*overloaded_p=*/NULL);
5120 if (result == NULL_TREE)
5121 return error_mark_node;
5128 /* A binary op has been requested. Combine the old LHS
5129 value with the RHS producing the value we should actually
5130 store into the LHS. */
5132 gcc_assert (!PROMOTES_TO_AGGR_TYPE (lhstype, REFERENCE_TYPE));
5133 lhs = stabilize_reference (lhs);
5134 newrhs = cp_build_binary_op (modifycode, lhs, rhs);
5135 if (newrhs == error_mark_node)
5137 error (" in evaluation of `%Q(%#T, %#T)'", modifycode,
5138 TREE_TYPE (lhs), TREE_TYPE (rhs));
5139 return error_mark_node;
5142 /* Now it looks like a plain assignment. */
5143 modifycode = NOP_EXPR;
5145 gcc_assert (TREE_CODE (lhstype) != REFERENCE_TYPE);
5146 gcc_assert (TREE_CODE (TREE_TYPE (newrhs)) != REFERENCE_TYPE);
5149 /* The left-hand side must be an lvalue. */
5150 if (!lvalue_or_else (lhs, "assignment"))
5151 return error_mark_node;
5153 /* Warn about modifying something that is `const'. Don't warn if
5154 this is initialization. */
5155 if (modifycode != INIT_EXPR
5156 && (TREE_READONLY (lhs) || CP_TYPE_CONST_P (lhstype)
5157 /* Functions are not modifiable, even though they are
5159 || TREE_CODE (TREE_TYPE (lhs)) == FUNCTION_TYPE
5160 || TREE_CODE (TREE_TYPE (lhs)) == METHOD_TYPE
5161 /* If it's an aggregate and any field is const, then it is
5162 effectively const. */
5163 || (CLASS_TYPE_P (lhstype)
5164 && C_TYPE_FIELDS_READONLY (lhstype))))
5165 readonly_error (lhs, "assignment", 0);
5167 /* If storing into a structure or union member, it has probably been
5168 given type `int'. Compute the type that would go with the actual
5169 amount of storage the member occupies. */
5171 if (TREE_CODE (lhs) == COMPONENT_REF
5172 && (TREE_CODE (lhstype) == INTEGER_TYPE
5173 || TREE_CODE (lhstype) == REAL_TYPE
5174 || TREE_CODE (lhstype) == ENUMERAL_TYPE))
5176 lhstype = TREE_TYPE (get_unwidened (lhs, 0));
5178 /* If storing in a field that is in actuality a short or narrower
5179 than one, we must store in the field in its actual type. */
5181 if (lhstype != TREE_TYPE (lhs))
5183 /* Avoid warnings converting integral types back into enums for
5185 if (TREE_CODE (lhstype) == INTEGER_TYPE
5186 && TREE_CODE (olhstype) == ENUMERAL_TYPE)
5188 if (TREE_SIDE_EFFECTS (lhs))
5189 lhs = stabilize_reference (lhs);
5192 lhs = copy_node (lhs);
5193 TREE_TYPE (lhs) = lhstype;
5197 /* Convert new value to destination type. */
5199 if (TREE_CODE (lhstype) == ARRAY_TYPE)
5203 if (!same_or_base_type_p (TYPE_MAIN_VARIANT (lhstype),
5204 TYPE_MAIN_VARIANT (TREE_TYPE (rhs))))
5206 error ("incompatible types in assignment of `%T' to `%T'",
5207 TREE_TYPE (rhs), lhstype);
5208 return error_mark_node;
5211 /* Allow array assignment in compiler-generated code. */
5212 if (! DECL_ARTIFICIAL (current_function_decl))
5213 pedwarn ("ISO C++ forbids assignment of arrays");
5215 from_array = TREE_CODE (TREE_TYPE (newrhs)) == ARRAY_TYPE
5216 ? 1 + (modifycode != INIT_EXPR): 0;
5217 return build_vec_init (lhs, NULL_TREE, newrhs, from_array);
5220 if (modifycode == INIT_EXPR)
5221 newrhs = convert_for_initialization (lhs, lhstype, newrhs, LOOKUP_NORMAL,
5222 "initialization", NULL_TREE, 0);
5225 /* Avoid warnings on enum bit fields. */
5226 if (TREE_CODE (olhstype) == ENUMERAL_TYPE
5227 && TREE_CODE (lhstype) == INTEGER_TYPE)
5229 newrhs = convert_for_assignment (olhstype, newrhs, "assignment",
5231 newrhs = convert_force (lhstype, newrhs, 0);
5234 newrhs = convert_for_assignment (lhstype, newrhs, "assignment",
5236 if (TREE_CODE (newrhs) == CALL_EXPR
5237 && TYPE_NEEDS_CONSTRUCTING (lhstype))
5238 newrhs = build_cplus_new (lhstype, newrhs);
5240 /* Can't initialize directly from a TARGET_EXPR, since that would
5241 cause the lhs to be constructed twice, and possibly result in
5242 accidental self-initialization. So we force the TARGET_EXPR to be
5243 expanded without a target. */
5244 if (TREE_CODE (newrhs) == TARGET_EXPR)
5245 newrhs = build2 (COMPOUND_EXPR, TREE_TYPE (newrhs), newrhs,
5246 TREE_OPERAND (newrhs, 0));
5249 if (newrhs == error_mark_node)
5250 return error_mark_node;
5252 result = build2 (modifycode == NOP_EXPR ? MODIFY_EXPR : INIT_EXPR,
5253 lhstype, lhs, newrhs);
5255 TREE_SIDE_EFFECTS (result) = 1;
5257 TREE_NO_WARNING (result) = 1;
5259 /* If we got the LHS in a different type for storing in,
5260 convert the result back to the nominal type of LHS
5261 so that the value we return always has the same type
5262 as the LHS argument. */
5264 if (olhstype == TREE_TYPE (result))
5268 result = build2 (COMPOUND_EXPR, olhstype, result, olhs);
5269 TREE_NO_WARNING (result) = 1;
5272 return convert_for_assignment (olhstype, result, "assignment",
5277 build_x_modify_expr (tree lhs, enum tree_code modifycode, tree rhs)
5279 if (processing_template_decl)
5280 return build_min_nt (MODOP_EXPR, lhs,
5281 build_min_nt (modifycode, NULL_TREE, NULL_TREE), rhs);
5283 if (modifycode != NOP_EXPR)
5285 tree rval = build_new_op (MODIFY_EXPR, LOOKUP_NORMAL, lhs, rhs,
5286 make_node (modifycode),
5287 /*overloaded_p=*/NULL);
5290 TREE_NO_WARNING (rval) = 1;
5294 return build_modify_expr (lhs, modifycode, rhs);
5298 /* Get difference in deltas for different pointer to member function
5299 types. Returns an integer constant of type PTRDIFF_TYPE_NODE. If
5300 the conversion is invalid, the constant is zero. If FORCE is true,
5301 then allow reverse conversions as well.
5303 Note that the naming of FROM and TO is kind of backwards; the return
5304 value is what we add to a TO in order to get a FROM. They are named
5305 this way because we call this function to find out how to convert from
5306 a pointer to member of FROM to a pointer to member of TO. */
5309 get_delta_difference (tree from, tree to, int force)
5316 /* Assume no conversion is required. */
5317 result = integer_zero_node;
5318 binfo = lookup_base (to, from, ba_check, &kind);
5319 if (kind == bk_inaccessible || kind == bk_ambig)
5320 error (" in pointer to member function conversion");
5325 error_not_base_type (from, to);
5326 error (" in pointer to member conversion");
5330 binfo = lookup_base (from, to, ba_check, &kind);
5333 virt_binfo = binfo_from_vbase (binfo);
5335 /* This is a reinterpret cast, we choose to do nothing. */
5336 warning ("pointer to member cast via virtual base `%T'",
5337 BINFO_TYPE (virt_binfo));
5339 result = size_diffop (size_zero_node, BINFO_OFFSET (binfo));
5345 virt_binfo = binfo_from_vbase (binfo);
5347 result = BINFO_OFFSET (binfo);
5350 /* This is a reinterpret cast, we choose to do nothing. */
5352 warning ("pointer to member cast via virtual base `%T'",
5353 BINFO_TYPE (virt_binfo));
5355 error ("pointer to member conversion via virtual base `%T'",
5356 BINFO_TYPE (virt_binfo));
5360 return fold (convert_to_integer (ptrdiff_type_node, result));
5363 /* Return a constructor for the pointer-to-member-function TYPE using
5364 the other components as specified. */
5367 build_ptrmemfunc1 (tree type, tree delta, tree pfn)
5373 /* Pull the FIELD_DECLs out of the type. */
5374 pfn_field = TYPE_FIELDS (type);
5375 delta_field = TREE_CHAIN (pfn_field);
5377 /* Make sure DELTA has the type we want. */
5378 delta = convert_and_check (delta_type_node, delta);
5380 /* Finish creating the initializer. */
5381 u = tree_cons (pfn_field, pfn,
5382 build_tree_list (delta_field, delta));
5383 u = build_constructor (type, u);
5384 TREE_CONSTANT (u) = TREE_CONSTANT (pfn) & TREE_CONSTANT (delta);
5385 TREE_INVARIANT (u) = TREE_INVARIANT (pfn) & TREE_INVARIANT (delta);
5386 TREE_STATIC (u) = (TREE_CONSTANT (u)
5387 && (initializer_constant_valid_p (pfn, TREE_TYPE (pfn))
5389 && (initializer_constant_valid_p (delta, TREE_TYPE (delta))
5394 /* Build a constructor for a pointer to member function. It can be
5395 used to initialize global variables, local variable, or used
5396 as a value in expressions. TYPE is the POINTER to METHOD_TYPE we
5399 If FORCE is nonzero, then force this conversion, even if
5400 we would rather not do it. Usually set when using an explicit
5403 Return error_mark_node, if something goes wrong. */
5406 build_ptrmemfunc (tree type, tree pfn, int force)
5412 if (error_operand_p (pfn))
5413 return error_mark_node;
5415 pfn_type = TREE_TYPE (pfn);
5416 to_type = build_ptrmemfunc_type (type);
5418 /* Handle multiple conversions of pointer to member functions. */
5419 if (TYPE_PTRMEMFUNC_P (pfn_type))
5421 tree delta = NULL_TREE;
5422 tree npfn = NULL_TREE;
5426 && !can_convert_arg (to_type, TREE_TYPE (pfn), pfn))
5427 error ("invalid conversion to type `%T' from type `%T'",
5430 n = get_delta_difference (TYPE_PTRMEMFUNC_OBJECT_TYPE (pfn_type),
5431 TYPE_PTRMEMFUNC_OBJECT_TYPE (to_type),
5434 /* We don't have to do any conversion to convert a
5435 pointer-to-member to its own type. But, we don't want to
5436 just return a PTRMEM_CST if there's an explicit cast; that
5437 cast should make the expression an invalid template argument. */
5438 if (TREE_CODE (pfn) != PTRMEM_CST)
5440 if (same_type_p (to_type, pfn_type))
5442 else if (integer_zerop (n))
5443 return build_reinterpret_cast (to_type, pfn);
5446 if (TREE_SIDE_EFFECTS (pfn))
5447 pfn = save_expr (pfn);
5449 /* Obtain the function pointer and the current DELTA. */
5450 if (TREE_CODE (pfn) == PTRMEM_CST)
5451 expand_ptrmemfunc_cst (pfn, &delta, &npfn);
5454 npfn = build_ptrmemfunc_access_expr (pfn, pfn_identifier);
5455 delta = build_ptrmemfunc_access_expr (pfn, delta_identifier);
5458 /* Just adjust the DELTA field. */
5459 gcc_assert (same_type_ignoring_top_level_qualifiers_p
5460 (TREE_TYPE (delta), ptrdiff_type_node));
5461 if (TARGET_PTRMEMFUNC_VBIT_LOCATION == ptrmemfunc_vbit_in_delta)
5462 n = cp_build_binary_op (LSHIFT_EXPR, n, integer_one_node);
5463 delta = cp_build_binary_op (PLUS_EXPR, delta, n);
5464 return build_ptrmemfunc1 (to_type, delta, npfn);
5467 /* Handle null pointer to member function conversions. */
5468 if (integer_zerop (pfn))
5470 pfn = build_c_cast (type, integer_zero_node);
5471 return build_ptrmemfunc1 (to_type,
5476 if (type_unknown_p (pfn))
5477 return instantiate_type (type, pfn, tf_error | tf_warning);
5479 fn = TREE_OPERAND (pfn, 0);
5480 gcc_assert (TREE_CODE (fn) == FUNCTION_DECL);
5481 return make_ptrmem_cst (to_type, fn);
5484 /* Return the DELTA, IDX, PFN, and DELTA2 values for the PTRMEM_CST
5487 ??? There is no consistency as to the types returned for the above
5488 values. Some code acts as if it were a sizetype and some as if it were
5489 integer_type_node. */
5492 expand_ptrmemfunc_cst (tree cst, tree *delta, tree *pfn)
5494 tree type = TREE_TYPE (cst);
5495 tree fn = PTRMEM_CST_MEMBER (cst);
5496 tree ptr_class, fn_class;
5498 gcc_assert (TREE_CODE (fn) == FUNCTION_DECL);
5500 /* The class that the function belongs to. */
5501 fn_class = DECL_CONTEXT (fn);
5503 /* The class that we're creating a pointer to member of. */
5504 ptr_class = TYPE_PTRMEMFUNC_OBJECT_TYPE (type);
5506 /* First, calculate the adjustment to the function's class. */
5507 *delta = get_delta_difference (fn_class, ptr_class, /*force=*/0);
5509 if (!DECL_VIRTUAL_P (fn))
5510 *pfn = convert (TYPE_PTRMEMFUNC_FN_TYPE (type), build_addr_func (fn));
5513 /* If we're dealing with a virtual function, we have to adjust 'this'
5514 again, to point to the base which provides the vtable entry for
5515 fn; the call will do the opposite adjustment. */
5516 tree orig_class = DECL_CONTEXT (fn);
5517 tree binfo = binfo_or_else (orig_class, fn_class);
5518 *delta = fold (build2 (PLUS_EXPR, TREE_TYPE (*delta),
5519 *delta, BINFO_OFFSET (binfo)));
5521 /* We set PFN to the vtable offset at which the function can be
5522 found, plus one (unless ptrmemfunc_vbit_in_delta, in which
5523 case delta is shifted left, and then incremented). */
5524 *pfn = DECL_VINDEX (fn);
5525 *pfn = fold (build2 (MULT_EXPR, integer_type_node, *pfn,
5526 TYPE_SIZE_UNIT (vtable_entry_type)));
5528 switch (TARGET_PTRMEMFUNC_VBIT_LOCATION)
5530 case ptrmemfunc_vbit_in_pfn:
5531 *pfn = fold (build2 (PLUS_EXPR, integer_type_node, *pfn,
5535 case ptrmemfunc_vbit_in_delta:
5536 *delta = fold (build2 (LSHIFT_EXPR, TREE_TYPE (*delta),
5537 *delta, integer_one_node));
5538 *delta = fold (build2 (PLUS_EXPR, TREE_TYPE (*delta),
5539 *delta, integer_one_node));
5546 *pfn = fold (build1 (NOP_EXPR, TYPE_PTRMEMFUNC_FN_TYPE (type),
5551 /* Return an expression for PFN from the pointer-to-member function
5555 pfn_from_ptrmemfunc (tree t)
5557 if (TREE_CODE (t) == PTRMEM_CST)
5562 expand_ptrmemfunc_cst (t, &delta, &pfn);
5567 return build_ptrmemfunc_access_expr (t, pfn_identifier);
5570 /* Expression EXPR is about to be implicitly converted to TYPE. Warn
5571 if this is a potentially dangerous thing to do. Returns a possibly
5575 dubious_conversion_warnings (tree type, tree expr,
5576 const char *errtype, tree fndecl, int parmnum)
5578 type = non_reference (type);
5580 /* Issue warnings about peculiar, but valid, uses of NULL. */
5581 if (ARITHMETIC_TYPE_P (type) && expr == null_node)
5584 warning ("passing NULL used for non-pointer %s %P of `%D'",
5585 errtype, parmnum, fndecl);
5587 warning ("%s to non-pointer type `%T' from NULL", errtype, type);
5590 /* Warn about assigning a floating-point type to an integer type. */
5591 if (TREE_CODE (TREE_TYPE (expr)) == REAL_TYPE
5592 && TREE_CODE (type) == INTEGER_TYPE)
5595 warning ("passing `%T' for %s %P of `%D'",
5596 TREE_TYPE (expr), errtype, parmnum, fndecl);
5598 warning ("%s to `%T' from `%T'", errtype, type, TREE_TYPE (expr));
5600 /* And warn about assigning a negative value to an unsigned
5602 else if (TYPE_UNSIGNED (type) && TREE_CODE (type) != BOOLEAN_TYPE)
5604 if (TREE_CODE (expr) == INTEGER_CST && TREE_NEGATED_INT (expr))
5607 warning ("passing negative value `%E' for %s %P of `%D'",
5608 expr, errtype, parmnum, fndecl);
5610 warning ("%s of negative value `%E' to `%T'",
5611 errtype, expr, type);
5614 overflow_warning (expr);
5616 if (TREE_CONSTANT (expr))
5622 /* Convert value RHS to type TYPE as preparation for an assignment to
5623 an lvalue of type TYPE. ERRTYPE is a string to use in error
5624 messages: "assignment", "return", etc. If FNDECL is non-NULL, we
5625 are doing the conversion in order to pass the PARMNUMth argument of
5629 convert_for_assignment (tree type, tree rhs,
5630 const char *errtype, tree fndecl, int parmnum)
5633 enum tree_code coder;
5635 /* Strip NON_LVALUE_EXPRs since we aren't using as an lvalue. */
5636 if (TREE_CODE (rhs) == NON_LVALUE_EXPR)
5637 rhs = TREE_OPERAND (rhs, 0);
5639 rhstype = TREE_TYPE (rhs);
5640 coder = TREE_CODE (rhstype);
5642 if (TREE_CODE (type) == VECTOR_TYPE && coder == VECTOR_TYPE
5643 && vector_types_convertible_p (type, rhstype))
5644 return convert (type, rhs);
5646 if (rhs == error_mark_node || rhstype == error_mark_node)
5647 return error_mark_node;
5648 if (TREE_CODE (rhs) == TREE_LIST && TREE_VALUE (rhs) == error_mark_node)
5649 return error_mark_node;
5651 /* The RHS of an assignment cannot have void type. */
5652 if (coder == VOID_TYPE)
5654 error ("void value not ignored as it ought to be");
5655 return error_mark_node;
5658 /* Simplify the RHS if possible. */
5659 if (TREE_CODE (rhs) == CONST_DECL)
5660 rhs = DECL_INITIAL (rhs);
5662 /* We do not use decl_constant_value here because of this case:
5664 const char* const s = "s";
5666 The conversion rules for a string literal are more lax than for a
5667 variable; in particular, a string literal can be converted to a
5668 "char *" but the variable "s" cannot be converted in the same
5669 way. If the conversion is allowed, the optimization should be
5670 performed while creating the converted expression. */
5674 The expression is implicitly converted (clause _conv_) to the
5675 cv-unqualified type of the left operand.
5677 We allow bad conversions here because by the time we get to this point
5678 we are committed to doing the conversion. If we end up doing a bad
5679 conversion, convert_like will complain. */
5680 if (!can_convert_arg_bad (type, rhstype, rhs))
5682 /* When -Wno-pmf-conversions is use, we just silently allow
5683 conversions from pointers-to-members to plain pointers. If
5684 the conversion doesn't work, cp_convert will complain. */
5686 && TYPE_PTR_P (type)
5687 && TYPE_PTRMEMFUNC_P (rhstype))
5688 rhs = cp_convert (strip_top_quals (type), rhs);
5691 /* If the right-hand side has unknown type, then it is an
5692 overloaded function. Call instantiate_type to get error
5694 if (rhstype == unknown_type_node)
5695 instantiate_type (type, rhs, tf_error | tf_warning);
5697 error ("cannot convert `%T' to `%T' for argument `%P' to `%D'",
5698 rhstype, type, parmnum, fndecl);
5700 error ("cannot convert `%T' to `%T' in %s", rhstype, type,
5702 return error_mark_node;
5705 return perform_implicit_conversion (strip_top_quals (type), rhs);
5708 /* Convert RHS to be of type TYPE.
5709 If EXP is nonzero, it is the target of the initialization.
5710 ERRTYPE is a string to use in error messages.
5712 Two major differences between the behavior of
5713 `convert_for_assignment' and `convert_for_initialization'
5714 are that references are bashed in the former, while
5715 copied in the latter, and aggregates are assigned in
5716 the former (operator=) while initialized in the
5719 If using constructor make sure no conversion operator exists, if one does
5720 exist, an ambiguity exists.
5722 If flags doesn't include LOOKUP_COMPLAIN, don't complain about anything. */
5725 convert_for_initialization (tree exp, tree type, tree rhs, int flags,
5726 const char *errtype, tree fndecl, int parmnum)
5728 enum tree_code codel = TREE_CODE (type);
5730 enum tree_code coder;
5732 /* build_c_cast puts on a NOP_EXPR to make the result not an lvalue.
5733 Strip such NOP_EXPRs, since RHS is used in non-lvalue context. */
5734 if (TREE_CODE (rhs) == NOP_EXPR
5735 && TREE_TYPE (rhs) == TREE_TYPE (TREE_OPERAND (rhs, 0))
5736 && codel != REFERENCE_TYPE)
5737 rhs = TREE_OPERAND (rhs, 0);
5739 if (rhs == error_mark_node
5740 || (TREE_CODE (rhs) == TREE_LIST && TREE_VALUE (rhs) == error_mark_node))
5741 return error_mark_node;
5743 if (TREE_CODE (TREE_TYPE (rhs)) == REFERENCE_TYPE)
5744 rhs = convert_from_reference (rhs);
5746 if ((TREE_CODE (TREE_TYPE (rhs)) == ARRAY_TYPE
5747 && TREE_CODE (type) != ARRAY_TYPE
5748 && (TREE_CODE (type) != REFERENCE_TYPE
5749 || TREE_CODE (TREE_TYPE (type)) != ARRAY_TYPE))
5750 || (TREE_CODE (TREE_TYPE (rhs)) == FUNCTION_TYPE
5751 && (TREE_CODE (type) != REFERENCE_TYPE
5752 || TREE_CODE (TREE_TYPE (type)) != FUNCTION_TYPE))
5753 || TREE_CODE (TREE_TYPE (rhs)) == METHOD_TYPE)
5754 rhs = decay_conversion (rhs);
5756 rhstype = TREE_TYPE (rhs);
5757 coder = TREE_CODE (rhstype);
5759 if (coder == ERROR_MARK)
5760 return error_mark_node;
5762 /* We accept references to incomplete types, so we can
5763 return here before checking if RHS is of complete type. */
5765 if (codel == REFERENCE_TYPE)
5767 /* This should eventually happen in convert_arguments. */
5768 int savew = 0, savee = 0;
5771 savew = warningcount, savee = errorcount;
5772 rhs = initialize_reference (type, rhs, /*decl=*/NULL_TREE,
5776 if (warningcount > savew)
5777 cp_warning_at ("in passing argument %P of `%+D'", parmnum, fndecl);
5778 else if (errorcount > savee)
5779 cp_error_at ("in passing argument %P of `%+D'", parmnum, fndecl);
5785 exp = require_complete_type (exp);
5786 if (exp == error_mark_node)
5787 return error_mark_node;
5789 rhstype = non_reference (rhstype);
5791 type = complete_type (type);
5793 if (IS_AGGR_TYPE (type))
5794 return ocp_convert (type, rhs, CONV_IMPLICIT|CONV_FORCE_TEMP, flags);
5796 return convert_for_assignment (type, rhs, errtype, fndecl, parmnum);
5799 /* If RETVAL is the address of, or a reference to, a local variable or
5800 temporary give an appropriate warning. */
5803 maybe_warn_about_returning_address_of_local (tree retval)
5805 tree valtype = TREE_TYPE (DECL_RESULT (current_function_decl));
5806 tree whats_returned = retval;
5810 if (TREE_CODE (whats_returned) == COMPOUND_EXPR)
5811 whats_returned = TREE_OPERAND (whats_returned, 1);
5812 else if (TREE_CODE (whats_returned) == CONVERT_EXPR
5813 || TREE_CODE (whats_returned) == NON_LVALUE_EXPR
5814 || TREE_CODE (whats_returned) == NOP_EXPR)
5815 whats_returned = TREE_OPERAND (whats_returned, 0);
5820 if (TREE_CODE (whats_returned) != ADDR_EXPR)
5822 whats_returned = TREE_OPERAND (whats_returned, 0);
5824 if (TREE_CODE (valtype) == REFERENCE_TYPE)
5826 if (TREE_CODE (whats_returned) == AGGR_INIT_EXPR
5827 || TREE_CODE (whats_returned) == TARGET_EXPR)
5829 warning ("returning reference to temporary");
5832 if (TREE_CODE (whats_returned) == VAR_DECL
5833 && DECL_NAME (whats_returned)
5834 && TEMP_NAME_P (DECL_NAME (whats_returned)))
5836 warning ("reference to non-lvalue returned");
5841 if (DECL_P (whats_returned)
5842 && DECL_NAME (whats_returned)
5843 && DECL_FUNCTION_SCOPE_P (whats_returned)
5844 && !(TREE_STATIC (whats_returned)
5845 || TREE_PUBLIC (whats_returned)))
5847 if (TREE_CODE (valtype) == REFERENCE_TYPE)
5848 cp_warning_at ("reference to local variable `%D' returned",
5851 cp_warning_at ("address of local variable `%D' returned",
5857 /* Check that returning RETVAL from the current function is valid.
5858 Return an expression explicitly showing all conversions required to
5859 change RETVAL into the function return type, and to assign it to
5860 the DECL_RESULT for the function. */
5863 check_return_expr (tree retval)
5866 /* The type actually returned by the function, after any
5869 int fn_returns_value_p;
5871 /* A `volatile' function is one that isn't supposed to return, ever.
5872 (This is a G++ extension, used to get better code for functions
5873 that call the `volatile' function.) */
5874 if (TREE_THIS_VOLATILE (current_function_decl))
5875 warning ("function declared `noreturn' has a `return' statement");
5877 /* Check for various simple errors. */
5878 if (DECL_DESTRUCTOR_P (current_function_decl))
5881 error ("returning a value from a destructor");
5884 else if (DECL_CONSTRUCTOR_P (current_function_decl))
5886 if (in_function_try_handler)
5887 /* If a return statement appears in a handler of the
5888 function-try-block of a constructor, the program is ill-formed. */
5889 error ("cannot return from a handler of a function-try-block of a constructor");
5891 /* You can't return a value from a constructor. */
5892 error ("returning a value from a constructor");
5896 if (processing_template_decl)
5898 current_function_returns_value = 1;
5902 /* When no explicit return-value is given in a function with a named
5903 return value, the named return value is used. */
5904 result = DECL_RESULT (current_function_decl);
5905 valtype = TREE_TYPE (result);
5906 gcc_assert (valtype != NULL_TREE);
5907 fn_returns_value_p = !VOID_TYPE_P (valtype);
5908 if (!retval && DECL_NAME (result) && fn_returns_value_p)
5911 /* Check for a return statement with no return value in a function
5912 that's supposed to return a value. */
5913 if (!retval && fn_returns_value_p)
5915 pedwarn ("return-statement with no value, in function returning '%T'",
5917 /* Clear this, so finish_function won't say that we reach the
5918 end of a non-void function (which we don't, we gave a
5920 current_function_returns_null = 0;
5922 /* Check for a return statement with a value in a function that
5923 isn't supposed to return a value. */
5924 else if (retval && !fn_returns_value_p)
5926 if (VOID_TYPE_P (TREE_TYPE (retval)))
5927 /* You can return a `void' value from a function of `void'
5928 type. In that case, we have to evaluate the expression for
5929 its side-effects. */
5930 finish_expr_stmt (retval);
5932 pedwarn ("return-statement with a value, in function "
5933 "returning 'void'");
5935 current_function_returns_null = 1;
5937 /* There's really no value to return, after all. */
5941 /* Remember that this function can sometimes return without a
5943 current_function_returns_null = 1;
5945 /* Remember that this function did return a value. */
5946 current_function_returns_value = 1;
5948 /* Only operator new(...) throw(), can return NULL [expr.new/13]. */
5949 if ((DECL_OVERLOADED_OPERATOR_P (current_function_decl) == NEW_EXPR
5950 || DECL_OVERLOADED_OPERATOR_P (current_function_decl) == VEC_NEW_EXPR)
5951 && !TYPE_NOTHROW_P (TREE_TYPE (current_function_decl))
5953 && null_ptr_cst_p (retval))
5954 warning ("`operator new' must not return NULL unless it is declared `throw()' (or -fcheck-new is in effect)");
5956 /* Effective C++ rule 15. See also start_function. */
5958 && DECL_NAME (current_function_decl) == ansi_assopname(NOP_EXPR))
5962 /* The function return type must be a reference to the current
5964 if (TREE_CODE (valtype) == REFERENCE_TYPE
5965 && same_type_ignoring_top_level_qualifiers_p
5966 (TREE_TYPE (valtype), TREE_TYPE (current_class_ref)))
5968 /* Returning '*this' is obviously OK. */
5969 if (retval == current_class_ref)
5971 /* If we are calling a function whose return type is the same of
5972 the current class reference, it is ok. */
5973 else if (TREE_CODE (retval) == INDIRECT_REF
5974 && TREE_CODE (TREE_OPERAND (retval, 0)) == CALL_EXPR)
5979 warning ("`operator=' should return a reference to `*this'");
5982 /* The fabled Named Return Value optimization, as per [class.copy]/15:
5984 [...] For a function with a class return type, if the expression
5985 in the return statement is the name of a local object, and the cv-
5986 unqualified type of the local object is the same as the function
5987 return type, an implementation is permitted to omit creating the tem-
5988 porary object to hold the function return value [...]
5990 So, if this is a value-returning function that always returns the same
5991 local variable, remember it.
5993 It might be nice to be more flexible, and choose the first suitable
5994 variable even if the function sometimes returns something else, but
5995 then we run the risk of clobbering the variable we chose if the other
5996 returned expression uses the chosen variable somehow. And people expect
5997 this restriction, anyway. (jason 2000-11-19)
5999 See finish_function and finalize_nrv for the rest of this optimization. */
6001 if (fn_returns_value_p && flag_elide_constructors)
6003 if (retval != NULL_TREE
6004 && (current_function_return_value == NULL_TREE
6005 || current_function_return_value == retval)
6006 && TREE_CODE (retval) == VAR_DECL
6007 && DECL_CONTEXT (retval) == current_function_decl
6008 && ! TREE_STATIC (retval)
6009 && (DECL_ALIGN (retval)
6010 >= DECL_ALIGN (DECL_RESULT (current_function_decl)))
6011 && same_type_p ((TYPE_MAIN_VARIANT
6012 (TREE_TYPE (retval))),
6014 (TREE_TYPE (TREE_TYPE (current_function_decl))))))
6015 current_function_return_value = retval;
6017 current_function_return_value = error_mark_node;
6020 /* We don't need to do any conversions when there's nothing being
6022 if (!retval || retval == error_mark_node)
6025 /* Do any required conversions. */
6026 if (retval == result || DECL_CONSTRUCTOR_P (current_function_decl))
6027 /* No conversions are required. */
6031 /* The type the function is declared to return. */
6032 tree functype = TREE_TYPE (TREE_TYPE (current_function_decl));
6034 /* First convert the value to the function's return type, then
6035 to the type of return value's location to handle the
6036 case that functype is smaller than the valtype. */
6037 retval = convert_for_initialization
6038 (NULL_TREE, functype, retval, LOOKUP_NORMAL|LOOKUP_ONLYCONVERTING,
6039 "return", NULL_TREE, 0);
6040 retval = convert (valtype, retval);
6042 /* If the conversion failed, treat this just like `return;'. */
6043 if (retval == error_mark_node)
6045 /* We can't initialize a register from a AGGR_INIT_EXPR. */
6046 else if (! current_function_returns_struct
6047 && TREE_CODE (retval) == TARGET_EXPR
6048 && TREE_CODE (TREE_OPERAND (retval, 1)) == AGGR_INIT_EXPR)
6049 retval = build2 (COMPOUND_EXPR, TREE_TYPE (retval), retval,
6050 TREE_OPERAND (retval, 0));
6052 maybe_warn_about_returning_address_of_local (retval);
6055 /* Actually copy the value returned into the appropriate location. */
6056 if (retval && retval != result)
6057 retval = build2 (INIT_EXPR, TREE_TYPE (result), result, retval);
6063 /* Returns nonzero if the pointer-type FROM can be converted to the
6064 pointer-type TO via a qualification conversion. If CONSTP is -1,
6065 then we return nonzero if the pointers are similar, and the
6066 cv-qualification signature of FROM is a proper subset of that of TO.
6068 If CONSTP is positive, then all outer pointers have been
6072 comp_ptr_ttypes_real (tree to, tree from, int constp)
6074 bool to_more_cv_qualified = false;
6076 for (; ; to = TREE_TYPE (to), from = TREE_TYPE (from))
6078 if (TREE_CODE (to) != TREE_CODE (from))
6081 if (TREE_CODE (from) == OFFSET_TYPE
6082 && !same_type_p (TYPE_OFFSET_BASETYPE (from),
6083 TYPE_OFFSET_BASETYPE (to)))
6086 /* Const and volatile mean something different for function types,
6087 so the usual checks are not appropriate. */
6088 if (TREE_CODE (to) != FUNCTION_TYPE && TREE_CODE (to) != METHOD_TYPE)
6090 if (!at_least_as_qualified_p (to, from))
6093 if (!at_least_as_qualified_p (from, to))
6097 to_more_cv_qualified = true;
6101 constp &= TYPE_READONLY (to);
6104 if (TREE_CODE (to) != POINTER_TYPE && !TYPE_PTRMEM_P (to))
6105 return ((constp >= 0 || to_more_cv_qualified)
6106 && same_type_ignoring_top_level_qualifiers_p (to, from));
6110 /* When comparing, say, char ** to char const **, this function takes
6111 the 'char *' and 'char const *'. Do not pass non-pointer/reference
6112 types to this function. */
6115 comp_ptr_ttypes (tree to, tree from)
6117 return comp_ptr_ttypes_real (to, from, 1);
6120 /* Returns 1 if to and from are (possibly multi-level) pointers to the same
6121 type or inheritance-related types, regardless of cv-quals. */
6124 ptr_reasonably_similar (tree to, tree from)
6126 for (; ; to = TREE_TYPE (to), from = TREE_TYPE (from))
6128 /* Any target type is similar enough to void. */
6129 if (TREE_CODE (to) == VOID_TYPE
6130 || TREE_CODE (from) == VOID_TYPE)
6133 if (TREE_CODE (to) != TREE_CODE (from))
6136 if (TREE_CODE (from) == OFFSET_TYPE
6137 && comptypes (TYPE_OFFSET_BASETYPE (to),
6138 TYPE_OFFSET_BASETYPE (from),
6139 COMPARE_BASE | COMPARE_DERIVED))
6142 if (TREE_CODE (to) == INTEGER_TYPE
6143 && TYPE_PRECISION (to) == TYPE_PRECISION (from))
6146 if (TREE_CODE (to) == FUNCTION_TYPE)
6149 if (TREE_CODE (to) != POINTER_TYPE)
6151 (TYPE_MAIN_VARIANT (to), TYPE_MAIN_VARIANT (from),
6152 COMPARE_BASE | COMPARE_DERIVED);
6156 /* Like comp_ptr_ttypes, for const_cast. */
6159 comp_ptr_ttypes_const (tree to, tree from)
6161 for (; ; to = TREE_TYPE (to), from = TREE_TYPE (from))
6163 if (TREE_CODE (to) != TREE_CODE (from))
6166 if (TREE_CODE (from) == OFFSET_TYPE
6167 && same_type_p (TYPE_OFFSET_BASETYPE (from),
6168 TYPE_OFFSET_BASETYPE (to)))
6171 if (TREE_CODE (to) != POINTER_TYPE)
6172 return same_type_ignoring_top_level_qualifiers_p (to, from);
6176 /* Returns the type qualifiers for this type, including the qualifiers on the
6177 elements for an array type. */
6180 cp_type_quals (tree type)
6182 type = strip_array_types (type);
6183 if (type == error_mark_node)
6184 return TYPE_UNQUALIFIED;
6185 return TYPE_QUALS (type);
6188 /* Returns nonzero if the TYPE contains a mutable member. */
6191 cp_has_mutable_p (tree type)
6193 type = strip_array_types (type);
6195 return CLASS_TYPE_P (type) && CLASSTYPE_HAS_MUTABLE (type);
6198 /* Subroutine of casts_away_constness. Make T1 and T2 point at
6199 exemplar types such that casting T1 to T2 is casting away castness
6200 if and only if there is no implicit conversion from T1 to T2. */
6203 casts_away_constness_r (tree *t1, tree *t2)
6208 /* [expr.const.cast]
6210 For multi-level pointer to members and multi-level mixed pointers
6211 and pointers to members (conv.qual), the "member" aspect of a
6212 pointer to member level is ignored when determining if a const
6213 cv-qualifier has been cast away. */
6214 if (TYPE_PTRMEM_P (*t1))
6215 *t1 = build_pointer_type (TYPE_PTRMEM_POINTED_TO_TYPE (*t1));
6216 if (TYPE_PTRMEM_P (*t2))
6217 *t2 = build_pointer_type (TYPE_PTRMEM_POINTED_TO_TYPE (*t2));
6219 /* [expr.const.cast]
6221 For two pointer types:
6223 X1 is T1cv1,1 * ... cv1,N * where T1 is not a pointer type
6224 X2 is T2cv2,1 * ... cv2,M * where T2 is not a pointer type
6227 casting from X1 to X2 casts away constness if, for a non-pointer
6228 type T there does not exist an implicit conversion (clause
6231 Tcv1,(N-K+1) * cv1,(N-K+2) * ... cv1,N *
6235 Tcv2,(M-K+1) * cv2,(M-K+2) * ... cv2,M *. */
6237 if (TREE_CODE (*t1) != POINTER_TYPE
6238 || TREE_CODE (*t2) != POINTER_TYPE)
6240 *t1 = cp_build_qualified_type (void_type_node,
6241 cp_type_quals (*t1));
6242 *t2 = cp_build_qualified_type (void_type_node,
6243 cp_type_quals (*t2));
6247 quals1 = cp_type_quals (*t1);
6248 quals2 = cp_type_quals (*t2);
6249 *t1 = TREE_TYPE (*t1);
6250 *t2 = TREE_TYPE (*t2);
6251 casts_away_constness_r (t1, t2);
6252 *t1 = build_pointer_type (*t1);
6253 *t2 = build_pointer_type (*t2);
6254 *t1 = cp_build_qualified_type (*t1, quals1);
6255 *t2 = cp_build_qualified_type (*t2, quals2);
6258 /* Returns nonzero if casting from TYPE1 to TYPE2 casts away
6262 casts_away_constness (tree t1, tree t2)
6264 if (TREE_CODE (t2) == REFERENCE_TYPE)
6266 /* [expr.const.cast]
6268 Casting from an lvalue of type T1 to an lvalue of type T2
6269 using a reference cast casts away constness if a cast from an
6270 rvalue of type "pointer to T1" to the type "pointer to T2"
6271 casts away constness. */
6272 t1 = (TREE_CODE (t1) == REFERENCE_TYPE ? TREE_TYPE (t1) : t1);
6273 return casts_away_constness (build_pointer_type (t1),
6274 build_pointer_type (TREE_TYPE (t2)));
6277 if (TYPE_PTRMEM_P (t1) && TYPE_PTRMEM_P (t2))
6278 /* [expr.const.cast]
6280 Casting from an rvalue of type "pointer to data member of X
6281 of type T1" to the type "pointer to data member of Y of type
6282 T2" casts away constness if a cast from an rvalue of type
6283 "pointer to T1" to the type "pointer to T2" casts away
6285 return casts_away_constness
6286 (build_pointer_type (TYPE_PTRMEM_POINTED_TO_TYPE (t1)),
6287 build_pointer_type (TYPE_PTRMEM_POINTED_TO_TYPE (t2)));
6289 /* Casting away constness is only something that makes sense for
6290 pointer or reference types. */
6291 if (TREE_CODE (t1) != POINTER_TYPE
6292 || TREE_CODE (t2) != POINTER_TYPE)
6295 /* Top-level qualifiers don't matter. */
6296 t1 = TYPE_MAIN_VARIANT (t1);
6297 t2 = TYPE_MAIN_VARIANT (t2);
6298 casts_away_constness_r (&t1, &t2);
6299 if (!can_convert (t2, t1))
6305 /* If T is a REFERENCE_TYPE return the type to which T refers.
6306 Otherwise, return T itself. */
6309 non_reference (tree t)
6311 if (TREE_CODE (t) == REFERENCE_TYPE)