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 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.
29 There are also routines to build RETURN_STMT nodes and CASE_STMT nodes,
30 and to process initializations in declarations (since they work
31 like a strange sort of assignment). */
35 #include "coretypes.h"
45 #include "diagnostic.h"
49 static tree convert_for_assignment (tree, tree, const char *, tree, int);
50 static tree cp_pointer_int_sum (enum tree_code, tree, tree);
51 static tree rationalize_conditional_expr (enum tree_code, tree);
52 static int comp_ptr_ttypes_real (tree, tree, int);
53 static int comp_ptr_ttypes_const (tree, tree);
54 static bool comp_except_types (tree, tree, bool);
55 static bool comp_array_types (tree, tree, bool);
56 static tree common_base_type (tree, tree);
57 static tree lookup_anon_field (tree, tree);
58 static tree pointer_diff (tree, tree, tree);
59 static tree get_delta_difference (tree, tree, int);
60 static void casts_away_constness_r (tree *, tree *);
61 static bool casts_away_constness (tree, tree);
62 static void maybe_warn_about_returning_address_of_local (tree);
63 static tree lookup_destructor (tree, tree, tree);
65 /* Return the target type of TYPE, which means return T for:
66 T*, T&, T[], T (...), and otherwise, just T. */
69 target_type (tree type)
71 type = non_reference (type);
72 while (TREE_CODE (type) == POINTER_TYPE
73 || TREE_CODE (type) == ARRAY_TYPE
74 || TREE_CODE (type) == FUNCTION_TYPE
75 || TREE_CODE (type) == METHOD_TYPE
76 || TYPE_PTRMEM_P (type))
77 type = TREE_TYPE (type);
81 /* Do `exp = require_complete_type (exp);' to make sure exp
82 does not have an incomplete type. (That includes void types.)
83 Returns the error_mark_node if the VALUE does not have
84 complete type when this function returns. */
87 require_complete_type (tree value)
91 if (processing_template_decl || value == error_mark_node)
94 if (TREE_CODE (value) == OVERLOAD)
95 type = unknown_type_node;
97 type = TREE_TYPE (value);
99 /* First, detect a valid value with a complete type. */
100 if (COMPLETE_TYPE_P (type))
103 if (complete_type_or_else (type, value))
106 return error_mark_node;
109 /* Try to complete TYPE, if it is incomplete. For example, if TYPE is
110 a template instantiation, do the instantiation. Returns TYPE,
111 whether or not it could be completed, unless something goes
112 horribly wrong, in which case the error_mark_node is returned. */
115 complete_type (tree type)
117 if (type == NULL_TREE)
118 /* Rather than crash, we return something sure to cause an error
120 return error_mark_node;
122 if (type == error_mark_node || COMPLETE_TYPE_P (type))
124 else if (TREE_CODE (type) == ARRAY_TYPE && TYPE_DOMAIN (type))
126 tree t = complete_type (TREE_TYPE (type));
127 if (COMPLETE_TYPE_P (t) && ! processing_template_decl)
129 TYPE_NEEDS_CONSTRUCTING (type)
130 = TYPE_NEEDS_CONSTRUCTING (TYPE_MAIN_VARIANT (t));
131 TYPE_HAS_NONTRIVIAL_DESTRUCTOR (type)
132 = TYPE_HAS_NONTRIVIAL_DESTRUCTOR (TYPE_MAIN_VARIANT (t));
134 else if (CLASS_TYPE_P (type) && CLASSTYPE_TEMPLATE_INSTANTIATION (type))
135 instantiate_class_template (TYPE_MAIN_VARIANT (type));
140 /* Like complete_type, but issue an error if the TYPE cannot be completed.
141 VALUE is used for informative diagnostics. DIAG_TYPE indicates the type
142 of diagnostic: 0 for an error, 1 for a warning, 2 for a pedwarn.
143 Returns NULL_TREE if the type cannot be made complete. */
146 complete_type_or_diagnostic (tree type, tree value, int diag_type)
148 type = complete_type (type);
149 if (type == error_mark_node)
150 /* We already issued an error. */
152 else if (!COMPLETE_TYPE_P (type))
154 cxx_incomplete_type_diagnostic (value, type, diag_type);
161 /* Return truthvalue of whether type of EXP is instantiated. */
164 type_unknown_p (tree exp)
166 return (TREE_CODE (exp) == OVERLOAD
167 || TREE_CODE (exp) == TREE_LIST
168 || TREE_TYPE (exp) == unknown_type_node);
172 /* Return the common type of two parameter lists.
173 We assume that comptypes has already been done and returned 1;
174 if that isn't so, this may crash.
176 As an optimization, free the space we allocate if the parameter
177 lists are already common. */
180 commonparms (tree p1, tree p2)
182 tree oldargs = p1, newargs, n;
186 len = list_length (p1);
187 newargs = tree_last (p1);
189 if (newargs == void_list_node)
198 newargs = tree_cons (NULL_TREE, NULL_TREE, newargs);
203 p1 = TREE_CHAIN (p1), p2 = TREE_CHAIN (p2), n = TREE_CHAIN (n), i++)
205 if (TREE_PURPOSE (p1) && !TREE_PURPOSE (p2))
207 TREE_PURPOSE (n) = TREE_PURPOSE (p1);
210 else if (! TREE_PURPOSE (p1))
212 if (TREE_PURPOSE (p2))
214 TREE_PURPOSE (n) = TREE_PURPOSE (p2);
220 if (1 != simple_cst_equal (TREE_PURPOSE (p1), TREE_PURPOSE (p2)))
222 TREE_PURPOSE (n) = TREE_PURPOSE (p2);
224 if (TREE_VALUE (p1) != TREE_VALUE (p2))
227 TREE_VALUE (n) = merge_types (TREE_VALUE (p1), TREE_VALUE (p2));
230 TREE_VALUE (n) = TREE_VALUE (p1);
238 /* Given a type, perhaps copied for a typedef,
239 find the "original" version of it. */
241 original_type (tree t)
243 while (TYPE_NAME (t) != NULL_TREE)
245 tree x = TYPE_NAME (t);
246 if (TREE_CODE (x) != TYPE_DECL)
248 x = DECL_ORIGINAL_TYPE (x);
256 /* T1 and T2 are arithmetic or enumeration types. Return the type
257 that will result from the "usual arithmetic conversions" on T1 and
258 T2 as described in [expr]. */
261 type_after_usual_arithmetic_conversions (tree t1, tree t2)
263 enum tree_code code1 = TREE_CODE (t1);
264 enum tree_code code2 = TREE_CODE (t2);
267 /* FIXME: Attributes. */
268 my_friendly_assert (ARITHMETIC_TYPE_P (t1)
269 || TREE_CODE (t1) == COMPLEX_TYPE
270 || TREE_CODE (t1) == ENUMERAL_TYPE,
272 my_friendly_assert (ARITHMETIC_TYPE_P (t2)
273 || TREE_CODE (t2) == COMPLEX_TYPE
274 || TREE_CODE (t2) == ENUMERAL_TYPE,
277 /* In what follows, we slightly generalize the rules given in [expr] so
278 as to deal with `long long' and `complex'. First, merge the
280 attributes = (*targetm.merge_type_attributes) (t1, t2);
282 /* If one type is complex, form the common type of the non-complex
283 components, then make that complex. Use T1 or T2 if it is the
285 if (code1 == COMPLEX_TYPE || code2 == COMPLEX_TYPE)
287 tree subtype1 = code1 == COMPLEX_TYPE ? TREE_TYPE (t1) : t1;
288 tree subtype2 = code2 == COMPLEX_TYPE ? TREE_TYPE (t2) : t2;
290 = type_after_usual_arithmetic_conversions (subtype1, subtype2);
292 if (code1 == COMPLEX_TYPE && TREE_TYPE (t1) == subtype)
293 return build_type_attribute_variant (t1, attributes);
294 else if (code2 == COMPLEX_TYPE && TREE_TYPE (t2) == subtype)
295 return build_type_attribute_variant (t2, attributes);
297 return build_type_attribute_variant (build_complex_type (subtype),
301 /* If only one is real, use it as the result. */
302 if (code1 == REAL_TYPE && code2 != REAL_TYPE)
303 return build_type_attribute_variant (t1, attributes);
304 if (code2 == REAL_TYPE && code1 != REAL_TYPE)
305 return build_type_attribute_variant (t2, attributes);
307 /* Perform the integral promotions. */
308 if (code1 != REAL_TYPE)
310 t1 = type_promotes_to (t1);
311 t2 = type_promotes_to (t2);
314 /* Both real or both integers; use the one with greater precision. */
315 if (TYPE_PRECISION (t1) > TYPE_PRECISION (t2))
316 return build_type_attribute_variant (t1, attributes);
317 else if (TYPE_PRECISION (t2) > TYPE_PRECISION (t1))
318 return build_type_attribute_variant (t2, attributes);
320 /* The types are the same; no need to do anything fancy. */
321 if (TYPE_MAIN_VARIANT (t1) == TYPE_MAIN_VARIANT (t2))
322 return build_type_attribute_variant (t1, attributes);
324 if (code1 != REAL_TYPE)
326 /* If one is a sizetype, use it so size_binop doesn't blow up. */
327 if (TYPE_IS_SIZETYPE (t1) > TYPE_IS_SIZETYPE (t2))
328 return build_type_attribute_variant (t1, attributes);
329 if (TYPE_IS_SIZETYPE (t2) > TYPE_IS_SIZETYPE (t1))
330 return build_type_attribute_variant (t2, attributes);
332 /* If one is unsigned long long, then convert the other to unsigned
334 if (same_type_p (TYPE_MAIN_VARIANT (t1), long_long_unsigned_type_node)
335 || same_type_p (TYPE_MAIN_VARIANT (t2), long_long_unsigned_type_node))
336 return build_type_attribute_variant (long_long_unsigned_type_node,
338 /* If one is a long long, and the other is an unsigned long, and
339 long long can represent all the values of an unsigned long, then
340 convert to a long long. Otherwise, convert to an unsigned long
341 long. Otherwise, if either operand is long long, convert the
344 Since we're here, we know the TYPE_PRECISION is the same;
345 therefore converting to long long cannot represent all the values
346 of an unsigned long, so we choose unsigned long long in that
348 if (same_type_p (TYPE_MAIN_VARIANT (t1), long_long_integer_type_node)
349 || same_type_p (TYPE_MAIN_VARIANT (t2), long_long_integer_type_node))
351 tree t = ((TREE_UNSIGNED (t1) || TREE_UNSIGNED (t2))
352 ? long_long_unsigned_type_node
353 : long_long_integer_type_node);
354 return build_type_attribute_variant (t, attributes);
357 /* Go through the same procedure, but for longs. */
358 if (same_type_p (TYPE_MAIN_VARIANT (t1), long_unsigned_type_node)
359 || same_type_p (TYPE_MAIN_VARIANT (t2), long_unsigned_type_node))
360 return build_type_attribute_variant (long_unsigned_type_node,
362 if (same_type_p (TYPE_MAIN_VARIANT (t1), long_integer_type_node)
363 || same_type_p (TYPE_MAIN_VARIANT (t2), long_integer_type_node))
365 tree t = ((TREE_UNSIGNED (t1) || TREE_UNSIGNED (t2))
366 ? long_unsigned_type_node : long_integer_type_node);
367 return build_type_attribute_variant (t, attributes);
369 /* Otherwise prefer the unsigned one. */
370 if (TREE_UNSIGNED (t1))
371 return build_type_attribute_variant (t1, attributes);
373 return build_type_attribute_variant (t2, attributes);
377 if (same_type_p (TYPE_MAIN_VARIANT (t1), long_double_type_node)
378 || same_type_p (TYPE_MAIN_VARIANT (t2), long_double_type_node))
379 return build_type_attribute_variant (long_double_type_node,
381 if (same_type_p (TYPE_MAIN_VARIANT (t1), double_type_node)
382 || same_type_p (TYPE_MAIN_VARIANT (t2), double_type_node))
383 return build_type_attribute_variant (double_type_node,
385 if (same_type_p (TYPE_MAIN_VARIANT (t1), float_type_node)
386 || same_type_p (TYPE_MAIN_VARIANT (t2), float_type_node))
387 return build_type_attribute_variant (float_type_node,
390 /* Two floating-point types whose TYPE_MAIN_VARIANTs are none of
391 the standard C++ floating-point types. Logic earlier in this
392 function has already eliminated the possibility that
393 TYPE_PRECISION (t2) != TYPE_PRECISION (t1), so there's no
394 compelling reason to choose one or the other. */
395 return build_type_attribute_variant (t1, attributes);
399 /* Subroutine of composite_pointer_type to implement the recursive
400 case. See that function for documentation fo the parameters. */
403 composite_pointer_type_r (tree t1, tree t2, const char* location)
410 /* Determine the types pointed to by T1 and T2. */
411 if (TREE_CODE (t1) == POINTER_TYPE)
413 pointee1 = TREE_TYPE (t1);
414 pointee2 = TREE_TYPE (t2);
418 pointee1 = TYPE_PTRMEM_POINTED_TO_TYPE (t1);
419 pointee2 = TYPE_PTRMEM_POINTED_TO_TYPE (t2);
424 Otherwise, the composite pointer type is a pointer type
425 similar (_conv.qual_) to the type of one of the operands,
426 with a cv-qualification signature (_conv.qual_) that is the
427 union of the cv-qualification signatures of the operand
429 if (same_type_ignoring_top_level_qualifiers_p (pointee1, pointee2))
430 result_type = pointee1;
431 else if ((TREE_CODE (pointee1) == POINTER_TYPE
432 && TREE_CODE (pointee2) == POINTER_TYPE)
433 || (TYPE_PTR_TO_MEMBER_P (pointee1)
434 && TYPE_PTR_TO_MEMBER_P (pointee2)))
435 result_type = composite_pointer_type_r (pointee1, pointee2, location);
438 pedwarn ("%s between distinct pointer types `%T' and `%T' "
441 result_type = void_type_node;
443 result_type = cp_build_qualified_type (result_type,
444 (cp_type_quals (pointee1)
445 | cp_type_quals (pointee2)));
446 result_type = build_pointer_type (result_type);
447 /* If the original types were pointers to members, so is the
449 if (TYPE_PTR_TO_MEMBER_P (t1))
451 if (!same_type_p (TYPE_PTRMEM_CLASS_TYPE (t1),
452 TYPE_PTRMEM_CLASS_TYPE (t2)))
453 pedwarn ("%s between distinct pointer types `%T' and `%T' "
456 result_type = build_ptrmem_type (TYPE_PTRMEM_CLASS_TYPE (t1),
460 /* Merge the attributes. */
461 attributes = (*targetm.merge_type_attributes) (t1, t2);
462 return build_type_attribute_variant (result_type, attributes);
465 /* Return the composite pointer type (see [expr.rel]) for T1 and T2.
466 ARG1 and ARG2 are the values with those types. The LOCATION is a
467 string describing the current location, in case an error occurs.
469 This routine also implements the computation of a common type for
470 pointers-to-members as per [expr.eq]. */
473 composite_pointer_type (tree t1, tree t2, tree arg1, tree arg2,
474 const char* location)
481 If one operand is a null pointer constant, the composite pointer
482 type is the type of the other operand. */
483 if (null_ptr_cst_p (arg1))
485 if (null_ptr_cst_p (arg2))
492 If one of the operands has type "pointer to cv1 void*", then
493 the other has type "pointer to cv2T", and the composite pointer
494 type is "pointer to cv12 void", where cv12 is the union of cv1
497 If either type is a pointer to void, make sure it is T1. */
498 if (TREE_CODE (t2) == POINTER_TYPE && VOID_TYPE_P (TREE_TYPE (t2)))
506 /* Now, if T1 is a pointer to void, merge the qualifiers. */
507 if (TREE_CODE (t1) == POINTER_TYPE && VOID_TYPE_P (TREE_TYPE (t1)))
512 if (pedantic && TYPE_PTRFN_P (t2))
513 pedwarn ("ISO C++ forbids %s between pointer of type `void *' and pointer-to-function", location);
515 = cp_build_qualified_type (void_type_node,
516 (cp_type_quals (TREE_TYPE (t1))
517 | cp_type_quals (TREE_TYPE (t2))));
518 result_type = build_pointer_type (result_type);
519 /* Merge the attributes. */
520 attributes = (*targetm.merge_type_attributes) (t1, t2);
521 return build_type_attribute_variant (result_type, attributes);
524 /* [expr.eq] permits the application of a pointer conversion to
525 bring the pointers to a common type. */
526 if (TREE_CODE (t1) == POINTER_TYPE && TREE_CODE (t2) == POINTER_TYPE
527 && CLASS_TYPE_P (TREE_TYPE (t1))
528 && CLASS_TYPE_P (TREE_TYPE (t2))
529 && !same_type_ignoring_top_level_qualifiers_p (TREE_TYPE (t1),
532 class1 = TREE_TYPE (t1);
533 class2 = TREE_TYPE (t2);
535 if (DERIVED_FROM_P (class1, class2))
536 t2 = (build_pointer_type
537 (cp_build_qualified_type (class1, TYPE_QUALS (class2))));
538 else if (DERIVED_FROM_P (class2, class1))
539 t1 = (build_pointer_type
540 (cp_build_qualified_type (class2, TYPE_QUALS (class1))));
543 error ("%s between distinct pointer types `%T' and `%T' "
544 "lacks a cast", location, t1, t2);
545 return error_mark_node;
548 /* [expr.eq] permits the application of a pointer-to-member
549 conversion to change the class type of one of the types. */
550 else if (TYPE_PTR_TO_MEMBER_P (t1)
551 && !same_type_p (TYPE_PTRMEM_CLASS_TYPE (t1),
552 TYPE_PTRMEM_CLASS_TYPE (t2)))
554 class1 = TYPE_PTRMEM_CLASS_TYPE (t1);
555 class2 = TYPE_PTRMEM_CLASS_TYPE (t2);
557 if (DERIVED_FROM_P (class1, class2))
558 t1 = build_ptrmem_type (class2, TYPE_PTRMEM_POINTED_TO_TYPE (t1));
559 else if (DERIVED_FROM_P (class2, class1))
560 t2 = build_ptrmem_type (class1, TYPE_PTRMEM_POINTED_TO_TYPE (t2));
563 error ("%s between distinct pointer-to-member types `%T' and `%T' "
564 "lacks a cast", location, t1, t2);
565 return error_mark_node;
569 return composite_pointer_type_r (t1, t2, location);
572 /* Return the merged type of two types.
573 We assume that comptypes has already been done and returned 1;
574 if that isn't so, this may crash.
576 This just combines attributes and default arguments; any other
577 differences would cause the two types to compare unalike. */
580 merge_types (tree t1, tree t2)
582 register enum tree_code code1;
583 register enum tree_code code2;
586 /* Save time if the two types are the same. */
589 if (original_type (t1) == original_type (t2))
592 /* If one type is nonsense, use the other. */
593 if (t1 == error_mark_node)
595 if (t2 == error_mark_node)
598 /* Merge the attributes. */
599 attributes = (*targetm.merge_type_attributes) (t1, t2);
601 if (TYPE_PTRMEMFUNC_P (t1))
602 t1 = TYPE_PTRMEMFUNC_FN_TYPE (t1);
603 if (TYPE_PTRMEMFUNC_P (t2))
604 t2 = TYPE_PTRMEMFUNC_FN_TYPE (t2);
606 code1 = TREE_CODE (t1);
607 code2 = TREE_CODE (t2);
613 /* For two pointers, do this recursively on the target type. */
615 tree target = merge_types (TREE_TYPE (t1), TREE_TYPE (t2));
616 int quals = cp_type_quals (t1);
618 if (code1 == POINTER_TYPE)
619 t1 = build_pointer_type (target);
621 t1 = build_reference_type (target);
622 t1 = build_type_attribute_variant (t1, attributes);
623 t1 = cp_build_qualified_type (t1, quals);
625 if (TREE_CODE (target) == METHOD_TYPE)
626 t1 = build_ptrmemfunc_type (t1);
633 tree base = TYPE_OFFSET_BASETYPE (t1);
634 tree target = merge_types (TREE_TYPE (t1), TREE_TYPE (t2));
635 t1 = build_offset_type (base, target);
641 tree elt = merge_types (TREE_TYPE (t1), TREE_TYPE (t2));
642 /* Save space: see if the result is identical to one of the args. */
643 if (elt == TREE_TYPE (t1) && TYPE_DOMAIN (t1))
644 return build_type_attribute_variant (t1, attributes);
645 if (elt == TREE_TYPE (t2) && TYPE_DOMAIN (t2))
646 return build_type_attribute_variant (t2, attributes);
647 /* Merge the element types, and have a size if either arg has one. */
648 t1 = build_cplus_array_type
649 (elt, TYPE_DOMAIN (TYPE_DOMAIN (t1) ? t1 : t2));
654 /* Function types: prefer the one that specified arg types.
655 If both do, merge the arg types. Also merge the return types. */
657 tree valtype = merge_types (TREE_TYPE (t1), TREE_TYPE (t2));
658 tree p1 = TYPE_ARG_TYPES (t1);
659 tree p2 = TYPE_ARG_TYPES (t2);
662 /* Save space: see if the result is identical to one of the args. */
663 if (valtype == TREE_TYPE (t1) && ! p2)
664 return build_type_attribute_variant (t1, attributes);
665 if (valtype == TREE_TYPE (t2) && ! p1)
666 return build_type_attribute_variant (t2, attributes);
668 /* Simple way if one arg fails to specify argument types. */
669 if (p1 == NULL_TREE || TREE_VALUE (p1) == void_type_node)
671 rval = build_function_type (valtype, p2);
672 if ((raises = TYPE_RAISES_EXCEPTIONS (t2)))
673 rval = build_exception_variant (rval, raises);
674 return build_type_attribute_variant (rval, attributes);
676 raises = TYPE_RAISES_EXCEPTIONS (t1);
677 if (p2 == NULL_TREE || TREE_VALUE (p2) == void_type_node)
679 rval = build_function_type (valtype, p1);
681 rval = build_exception_variant (rval, raises);
682 return build_type_attribute_variant (rval, attributes);
685 rval = build_function_type (valtype, commonparms (p1, p2));
686 t1 = build_exception_variant (rval, raises);
692 /* Get this value the long way, since TYPE_METHOD_BASETYPE
693 is just the main variant of this. */
694 tree basetype = TREE_TYPE (TREE_VALUE (TYPE_ARG_TYPES (t2)));
695 tree raises = TYPE_RAISES_EXCEPTIONS (t1);
698 /* If this was a member function type, get back to the
699 original type of type member function (i.e., without
700 the class instance variable up front. */
701 t1 = build_function_type (TREE_TYPE (t1),
702 TREE_CHAIN (TYPE_ARG_TYPES (t1)));
703 t2 = build_function_type (TREE_TYPE (t2),
704 TREE_CHAIN (TYPE_ARG_TYPES (t2)));
705 t3 = merge_types (t1, t2);
706 t3 = build_cplus_method_type (basetype, TREE_TYPE (t3),
707 TYPE_ARG_TYPES (t3));
708 t1 = build_exception_variant (t3, raises);
714 return build_type_attribute_variant (t1, attributes);
717 /* Return the common type of two types.
718 We assume that comptypes has already been done and returned 1;
719 if that isn't so, this may crash.
721 This is the type for the result of most arithmetic operations
722 if the operands have the given two types. */
725 common_type (tree t1, tree t2)
727 enum tree_code code1;
728 enum tree_code code2;
730 /* If one type is nonsense, bail. */
731 if (t1 == error_mark_node || t2 == error_mark_node)
732 return error_mark_node;
734 code1 = TREE_CODE (t1);
735 code2 = TREE_CODE (t2);
737 if ((ARITHMETIC_TYPE_P (t1) || code1 == ENUMERAL_TYPE
738 || code1 == COMPLEX_TYPE)
739 && (ARITHMETIC_TYPE_P (t2) || code2 == ENUMERAL_TYPE
740 || code2 == COMPLEX_TYPE))
741 return type_after_usual_arithmetic_conversions (t1, t2);
743 else if ((TYPE_PTR_P (t1) && TYPE_PTR_P (t2))
744 || (TYPE_PTRMEM_P (t1) && TYPE_PTRMEM_P (t2))
745 || (TYPE_PTRMEMFUNC_P (t1) && TYPE_PTRMEMFUNC_P (t2)))
746 return composite_pointer_type (t1, t2, error_mark_node, error_mark_node,
752 /* Compare two exception specifier types for exactness or subsetness, if
753 allowed. Returns false for mismatch, true for match (same, or
756 [except.spec] "If a class X ... objects of class X or any class publicly
757 and unambiguously derived from X. Similarly, if a pointer type Y * ...
758 exceptions of type Y * or that are pointers to any type publicly and
759 unambiguously derived from Y. Otherwise a function only allows exceptions
760 that have the same type ..."
761 This does not mention cv qualifiers and is different to what throw
762 [except.throw] and catch [except.catch] will do. They will ignore the
763 top level cv qualifiers, and allow qualifiers in the pointer to class
766 We implement the letter of the standard. */
769 comp_except_types (tree a, tree b, bool exact)
771 if (same_type_p (a, b))
775 if (cp_type_quals (a) || cp_type_quals (b))
778 if (TREE_CODE (a) == POINTER_TYPE
779 && TREE_CODE (b) == POINTER_TYPE)
783 if (cp_type_quals (a) || cp_type_quals (b))
787 if (TREE_CODE (a) != RECORD_TYPE
788 || TREE_CODE (b) != RECORD_TYPE)
791 if (ACCESSIBLY_UNIQUELY_DERIVED_P (a, b))
797 /* Return true if TYPE1 and TYPE2 are equivalent exception specifiers.
798 If EXACT is false, T2 can be stricter than T1 (according to 15.4/7),
799 otherwise it must be exact. Exception lists are unordered, but
800 we've already filtered out duplicates. Most lists will be in order,
801 we should try to make use of that. */
804 comp_except_specs (tree t1, tree t2, bool exact)
813 if (t1 == NULL_TREE) /* T1 is ... */
814 return t2 == NULL_TREE || !exact;
815 if (!TREE_VALUE (t1)) /* t1 is EMPTY */
816 return t2 != NULL_TREE && !TREE_VALUE (t2);
817 if (t2 == NULL_TREE) /* T2 is ... */
819 if (TREE_VALUE (t1) && !TREE_VALUE (t2)) /* T2 is EMPTY, T1 is not */
822 /* Neither set is ... or EMPTY, make sure each part of T2 is in T1.
823 Count how many we find, to determine exactness. For exact matching and
824 ordered T1, T2, this is an O(n) operation, otherwise its worst case is
826 for (base = t1; t2 != NULL_TREE; t2 = TREE_CHAIN (t2))
828 for (probe = base; probe != NULL_TREE; probe = TREE_CHAIN (probe))
830 tree a = TREE_VALUE (probe);
831 tree b = TREE_VALUE (t2);
833 if (comp_except_types (a, b, exact))
835 if (probe == base && exact)
836 base = TREE_CHAIN (probe);
841 if (probe == NULL_TREE)
844 return !exact || base == NULL_TREE || length == list_length (t1);
847 /* Compare the array types T1 and T2. ALLOW_REDECLARATION is true if
848 [] can match [size]. */
851 comp_array_types (tree t1, tree t2, bool allow_redeclaration)
859 /* The type of the array elements must be the same. */
860 if (!same_type_p (TREE_TYPE (t1), TREE_TYPE (t2)))
863 d1 = TYPE_DOMAIN (t1);
864 d2 = TYPE_DOMAIN (t2);
869 /* If one of the arrays is dimensionless, and the other has a
870 dimension, they are of different types. However, it is valid to
878 declarations for an array object can specify
879 array types that differ by the presence or absence of a major
880 array bound (_dcl.array_). */
882 return allow_redeclaration;
884 /* Check that the dimensions are the same. */
885 return (cp_tree_equal (TYPE_MIN_VALUE (d1), TYPE_MIN_VALUE (d2))
886 && cp_tree_equal (TYPE_MAX_VALUE (d1), TYPE_MAX_VALUE (d2)));
889 /* Return true if T1 and T2 are related as allowed by STRICT. STRICT
890 is a bitwise-or of the COMPARE_* flags. */
893 comptypes (tree t1, tree t2, int strict)
898 /* This should never happen. */
899 my_friendly_assert (t1 != error_mark_node, 307);
901 /* Suppress errors caused by previously reported errors */
902 if (t2 == error_mark_node)
905 my_friendly_assert (TYPE_P (t1) && TYPE_P (t2), 20030623);
907 /* TYPENAME_TYPEs should be resolved if the qualifying scope is the
908 current instantiation. */
909 if (TREE_CODE (t1) == TYPENAME_TYPE)
911 tree resolved = resolve_typename_type (t1, /*only_current_p=*/true);
913 if (resolved != error_mark_node)
917 if (TREE_CODE (t2) == TYPENAME_TYPE)
919 tree resolved = resolve_typename_type (t2, /*only_current_p=*/true);
921 if (resolved != error_mark_node)
925 /* If either type is the internal version of sizetype, use the
927 if (TREE_CODE (t1) == INTEGER_TYPE && TYPE_IS_SIZETYPE (t1)
929 t1 = TYPE_DOMAIN (t1);
931 if (TREE_CODE (t2) == INTEGER_TYPE && TYPE_IS_SIZETYPE (t2)
933 t2 = TYPE_DOMAIN (t2);
935 if (TYPE_PTRMEMFUNC_P (t1))
936 t1 = TYPE_PTRMEMFUNC_FN_TYPE (t1);
937 if (TYPE_PTRMEMFUNC_P (t2))
938 t2 = TYPE_PTRMEMFUNC_FN_TYPE (t2);
940 /* Different classes of types can't be compatible. */
941 if (TREE_CODE (t1) != TREE_CODE (t2))
944 /* Qualifiers must match. */
945 if (cp_type_quals (t1) != cp_type_quals (t2))
947 if (TYPE_FOR_JAVA (t1) != TYPE_FOR_JAVA (t2))
950 /* Allow for two different type nodes which have essentially the same
951 definition. Note that we already checked for equality of the type
952 qualifiers (just above). */
954 if (TYPE_MAIN_VARIANT (t1) == TYPE_MAIN_VARIANT (t2))
957 if (!(*targetm.comp_type_attributes) (t1, t2))
960 switch (TREE_CODE (t1))
962 case TEMPLATE_TEMPLATE_PARM:
963 case BOUND_TEMPLATE_TEMPLATE_PARM:
964 if (TEMPLATE_TYPE_IDX (t1) != TEMPLATE_TYPE_IDX (t2)
965 || TEMPLATE_TYPE_LEVEL (t1) != TEMPLATE_TYPE_LEVEL (t2))
967 if (!comp_template_parms
968 (DECL_TEMPLATE_PARMS (TEMPLATE_TEMPLATE_PARM_TEMPLATE_DECL (t1)),
969 DECL_TEMPLATE_PARMS (TEMPLATE_TEMPLATE_PARM_TEMPLATE_DECL (t2))))
971 if (TREE_CODE (t1) == TEMPLATE_TEMPLATE_PARM)
973 /* Don't check inheritance. */
974 strict = COMPARE_STRICT;
979 if (TYPE_TEMPLATE_INFO (t1) && TYPE_TEMPLATE_INFO (t2)
980 && (TYPE_TI_TEMPLATE (t1) == TYPE_TI_TEMPLATE (t2)
981 || TREE_CODE (t1) == BOUND_TEMPLATE_TEMPLATE_PARM)
982 && comp_template_args (TYPE_TI_ARGS (t1), TYPE_TI_ARGS (t2)))
985 if ((strict & COMPARE_BASE) && DERIVED_FROM_P (t1, t2))
987 else if ((strict & COMPARE_DERIVED) && DERIVED_FROM_P (t2, t1))
993 if (!comptypes (TYPE_OFFSET_BASETYPE (t1), TYPE_OFFSET_BASETYPE (t2),
994 strict & ~COMPARE_REDECLARATION))
1000 return same_type_p (TREE_TYPE (t1), TREE_TYPE (t2));
1004 if (!same_type_p (TREE_TYPE (t1), TREE_TYPE (t2)))
1006 return compparms (TYPE_ARG_TYPES (t1), TYPE_ARG_TYPES (t2));
1009 /* Target types must match incl. qualifiers. */
1010 return comp_array_types (t1, t2, !!(strict & COMPARE_REDECLARATION));
1012 case TEMPLATE_TYPE_PARM:
1013 return (TEMPLATE_TYPE_IDX (t1) == TEMPLATE_TYPE_IDX (t2)
1014 && TEMPLATE_TYPE_LEVEL (t1) == TEMPLATE_TYPE_LEVEL (t2));
1017 if (!cp_tree_equal (TYPENAME_TYPE_FULLNAME (t1),
1018 TYPENAME_TYPE_FULLNAME (t2)))
1020 return same_type_p (TYPE_CONTEXT (t1), TYPE_CONTEXT (t2));
1022 case UNBOUND_CLASS_TEMPLATE:
1023 if (!cp_tree_equal (TYPE_IDENTIFIER (t1), TYPE_IDENTIFIER (t2)))
1025 return same_type_p (TYPE_CONTEXT (t1), TYPE_CONTEXT (t2));
1028 return same_type_p (TREE_TYPE (t1), TREE_TYPE (t2));
1036 /* Returns 1 if TYPE1 is at least as qualified as TYPE2. */
1039 at_least_as_qualified_p (tree type1, tree type2)
1041 int q1 = cp_type_quals (type1);
1042 int q2 = cp_type_quals (type2);
1044 /* All qualifiers for TYPE2 must also appear in TYPE1. */
1045 return (q1 & q2) == q2;
1048 /* Returns 1 if TYPE1 is more qualified than TYPE2. */
1051 more_qualified_p (tree type1, tree type2)
1053 int q1 = cp_type_quals (type1);
1054 int q2 = cp_type_quals (type2);
1056 return q1 != q2 && (q1 & q2) == q2;
1059 /* Returns 1 if TYPE1 is more cv-qualified than TYPE2, -1 if TYPE2 is
1060 more cv-qualified that TYPE1, and 0 otherwise. */
1063 comp_cv_qualification (tree type1, tree type2)
1065 int q1 = cp_type_quals (type1);
1066 int q2 = cp_type_quals (type2);
1071 if ((q1 & q2) == q2)
1073 else if ((q1 & q2) == q1)
1079 /* Returns 1 if the cv-qualification signature of TYPE1 is a proper
1080 subset of the cv-qualification signature of TYPE2, and the types
1081 are similar. Returns -1 if the other way 'round, and 0 otherwise. */
1084 comp_cv_qual_signature (tree type1, tree type2)
1086 if (comp_ptr_ttypes_real (type2, type1, -1))
1088 else if (comp_ptr_ttypes_real (type1, type2, -1))
1094 /* If two types share a common base type, return that basetype.
1095 If there is not a unique most-derived base type, this function
1096 returns ERROR_MARK_NODE. */
1099 common_base_type (tree tt1, tree tt2)
1101 tree best = NULL_TREE;
1104 /* If one is a baseclass of another, that's good enough. */
1105 if (UNIQUELY_DERIVED_FROM_P (tt1, tt2))
1107 if (UNIQUELY_DERIVED_FROM_P (tt2, tt1))
1110 /* Otherwise, try to find a unique baseclass of TT1
1111 that is shared by TT2, and follow that down. */
1112 for (i = CLASSTYPE_N_BASECLASSES (tt1)-1; i >= 0; i--)
1114 tree basetype = TYPE_BINFO_BASETYPE (tt1, i);
1115 tree trial = common_base_type (basetype, tt2);
1118 if (trial == error_mark_node)
1120 if (best == NULL_TREE)
1122 else if (best != trial)
1123 return error_mark_node;
1128 for (i = CLASSTYPE_N_BASECLASSES (tt2)-1; i >= 0; i--)
1130 tree basetype = TYPE_BINFO_BASETYPE (tt2, i);
1131 tree trial = common_base_type (tt1, basetype);
1134 if (trial == error_mark_node)
1136 if (best == NULL_TREE)
1138 else if (best != trial)
1139 return error_mark_node;
1145 /* Subroutines of `comptypes'. */
1147 /* Return true if two parameter type lists PARMS1 and PARMS2 are
1148 equivalent in the sense that functions with those parameter types
1149 can have equivalent types. The two lists must be equivalent,
1150 element by element. */
1153 compparms (tree parms1, tree parms2)
1157 /* An unspecified parmlist matches any specified parmlist
1158 whose argument types don't need default promotions. */
1160 for (t1 = parms1, t2 = parms2;
1162 t1 = TREE_CHAIN (t1), t2 = TREE_CHAIN (t2))
1164 /* If one parmlist is shorter than the other,
1165 they fail to match. */
1168 if (!same_type_p (TREE_VALUE (t2), TREE_VALUE (t1)))
1176 cxx_sizeof_or_alignof_type (tree type, enum tree_code op, int complain)
1178 enum tree_code type_code;
1180 const char *op_name;
1182 my_friendly_assert (op == SIZEOF_EXPR || op == ALIGNOF_EXPR, 20020720);
1183 if (processing_template_decl)
1184 return build_min (op, size_type_node, type);
1186 op_name = operator_name_info[(int) op].name;
1188 type = non_reference (type);
1189 type_code = TREE_CODE (type);
1191 if (type_code == METHOD_TYPE)
1193 if (complain && (pedantic || warn_pointer_arith))
1194 pedwarn ("invalid application of `%s' to a member function", op_name);
1195 value = size_one_node;
1198 value = c_sizeof_or_alignof_type (complete_type (type), op, complain);
1204 expr_sizeof (tree e)
1206 if (processing_template_decl)
1207 return build_min (SIZEOF_EXPR, size_type_node, e);
1209 if (TREE_CODE (e) == COMPONENT_REF
1210 && DECL_C_BIT_FIELD (TREE_OPERAND (e, 1)))
1211 error ("sizeof applied to a bit-field");
1212 if (is_overloaded_fn (e))
1214 pedwarn ("ISO C++ forbids applying `sizeof' to an expression of function type");
1215 return c_sizeof (char_type_node);
1217 else if (type_unknown_p (e))
1219 cxx_incomplete_type_error (e, TREE_TYPE (e));
1220 return c_sizeof (char_type_node);
1223 if (e == error_mark_node)
1226 return cxx_sizeof (TREE_TYPE (e));
1230 /* Perform the conversions in [expr] that apply when an lvalue appears
1231 in an rvalue context: the lvalue-to-rvalue, array-to-pointer, and
1232 function-to-pointer conversions.
1234 In addition manifest constants are replaced by their values. */
1237 decay_conversion (tree exp)
1240 register enum tree_code code;
1242 type = TREE_TYPE (exp);
1243 code = TREE_CODE (type);
1245 if (code == REFERENCE_TYPE)
1247 exp = convert_from_reference (exp);
1248 type = TREE_TYPE (exp);
1249 code = TREE_CODE (type);
1252 if (type == error_mark_node)
1253 return error_mark_node;
1255 if (type_unknown_p (exp))
1257 cxx_incomplete_type_error (exp, TREE_TYPE (exp));
1258 return error_mark_node;
1261 /* Constants can be used directly unless they're not loadable. */
1262 if (TREE_CODE (exp) == CONST_DECL)
1263 exp = DECL_INITIAL (exp);
1264 /* Replace a nonvolatile const static variable with its value. We
1265 don't do this for arrays, though; we want the address of the
1266 first element of the array, not the address of the first element
1267 of its initializing constant. */
1268 else if (code != ARRAY_TYPE)
1270 exp = decl_constant_value (exp);
1271 type = TREE_TYPE (exp);
1274 /* build_c_cast puts on a NOP_EXPR to make the result not an lvalue.
1275 Leave such NOP_EXPRs, since RHS is being used in non-lvalue context. */
1277 if (code == VOID_TYPE)
1279 error ("void value not ignored as it ought to be");
1280 return error_mark_node;
1282 if (code == METHOD_TYPE)
1284 error ("invalid use of non-static member function");
1285 return error_mark_node;
1287 if (code == FUNCTION_TYPE || is_overloaded_fn (exp))
1288 return build_unary_op (ADDR_EXPR, exp, 0);
1289 if (code == ARRAY_TYPE)
1294 if (TREE_CODE (exp) == INDIRECT_REF)
1295 return build_nop (build_pointer_type (TREE_TYPE (type)),
1296 TREE_OPERAND (exp, 0));
1298 if (TREE_CODE (exp) == COMPOUND_EXPR)
1300 tree op1 = decay_conversion (TREE_OPERAND (exp, 1));
1301 return build (COMPOUND_EXPR, TREE_TYPE (op1),
1302 TREE_OPERAND (exp, 0), op1);
1306 && ! (TREE_CODE (exp) == CONSTRUCTOR && TREE_STATIC (exp)))
1308 error ("invalid use of non-lvalue array");
1309 return error_mark_node;
1312 ptrtype = build_pointer_type (TREE_TYPE (type));
1314 if (TREE_CODE (exp) == VAR_DECL)
1316 /* ??? This is not really quite correct
1317 in that the type of the operand of ADDR_EXPR
1318 is not the target type of the type of the ADDR_EXPR itself.
1319 Question is, can this lossage be avoided? */
1320 adr = build1 (ADDR_EXPR, ptrtype, exp);
1321 if (!cxx_mark_addressable (exp))
1322 return error_mark_node;
1323 TREE_CONSTANT (adr) = staticp (exp);
1324 TREE_SIDE_EFFECTS (adr) = 0; /* Default would be, same as EXP. */
1327 /* This way is better for a COMPONENT_REF since it can
1328 simplify the offset for a component. */
1329 adr = build_unary_op (ADDR_EXPR, exp, 1);
1330 return cp_convert (ptrtype, adr);
1333 /* [basic.lval]: Class rvalues can have cv-qualified types; non-class
1334 rvalues always have cv-unqualified types. */
1335 if (! CLASS_TYPE_P (type))
1336 exp = cp_convert (TYPE_MAIN_VARIANT (type), exp);
1342 default_conversion (tree exp)
1344 exp = decay_conversion (exp);
1346 if (INTEGRAL_OR_ENUMERATION_TYPE_P (TREE_TYPE (exp)))
1347 exp = perform_integral_promotions (exp);
1352 /* EXPR is an expression with an integral or enumeration type.
1353 Perform the integral promotions in [conv.prom], and return the
1357 perform_integral_promotions (tree expr)
1362 type = TREE_TYPE (expr);
1363 my_friendly_assert (INTEGRAL_OR_ENUMERATION_TYPE_P (type), 20030703);
1364 promoted_type = type_promotes_to (type);
1365 if (type != promoted_type)
1366 expr = cp_convert (promoted_type, expr);
1370 /* Take the address of an inline function without setting TREE_ADDRESSABLE
1374 inline_conversion (tree exp)
1376 if (TREE_CODE (exp) == FUNCTION_DECL)
1377 exp = build1 (ADDR_EXPR, build_pointer_type (TREE_TYPE (exp)), exp);
1382 /* Returns nonzero iff exp is a STRING_CST or the result of applying
1383 decay_conversion to one. */
1386 string_conv_p (tree totype, tree exp, int warn)
1390 if (! flag_const_strings || TREE_CODE (totype) != POINTER_TYPE)
1393 t = TREE_TYPE (totype);
1394 if (!same_type_p (t, char_type_node)
1395 && !same_type_p (t, wchar_type_node))
1398 if (TREE_CODE (exp) == STRING_CST)
1400 /* Make sure that we don't try to convert between char and wchar_t. */
1401 if (!same_type_p (TYPE_MAIN_VARIANT (TREE_TYPE (TREE_TYPE (exp))), t))
1406 /* Is this a string constant which has decayed to 'const char *'? */
1407 t = build_pointer_type (build_qualified_type (t, TYPE_QUAL_CONST));
1408 if (!same_type_p (TREE_TYPE (exp), t))
1411 if (TREE_CODE (exp) != ADDR_EXPR
1412 || TREE_CODE (TREE_OPERAND (exp, 0)) != STRING_CST)
1416 /* This warning is not very useful, as it complains about printf. */
1417 if (warn && warn_write_strings)
1418 warning ("deprecated conversion from string constant to `%T'", totype);
1423 /* Given a COND_EXPR, MIN_EXPR, or MAX_EXPR in T, return it in a form that we
1424 can, for example, use as an lvalue. This code used to be in
1425 unary_complex_lvalue, but we needed it to deal with `a = (d == c) ? b : c'
1426 expressions, where we're dealing with aggregates. But now it's again only
1427 called from unary_complex_lvalue. The case (in particular) that led to
1428 this was with CODE == ADDR_EXPR, since it's not an lvalue when we'd
1432 rationalize_conditional_expr (enum tree_code code, tree t)
1434 /* For MIN_EXPR or MAX_EXPR, fold-const.c has arranged things so that
1435 the first operand is always the one to be used if both operands
1436 are equal, so we know what conditional expression this used to be. */
1437 if (TREE_CODE (t) == MIN_EXPR || TREE_CODE (t) == MAX_EXPR)
1440 build_conditional_expr (build_x_binary_op ((TREE_CODE (t) == MIN_EXPR
1441 ? LE_EXPR : GE_EXPR),
1442 TREE_OPERAND (t, 0),
1443 TREE_OPERAND (t, 1)),
1444 build_unary_op (code, TREE_OPERAND (t, 0), 0),
1445 build_unary_op (code, TREE_OPERAND (t, 1), 0));
1449 build_conditional_expr (TREE_OPERAND (t, 0),
1450 build_unary_op (code, TREE_OPERAND (t, 1), 0),
1451 build_unary_op (code, TREE_OPERAND (t, 2), 0));
1454 /* Given the TYPE of an anonymous union field inside T, return the
1455 FIELD_DECL for the field. If not found return NULL_TREE. Because
1456 anonymous unions can nest, we must also search all anonymous unions
1457 that are directly reachable. */
1460 lookup_anon_field (tree t, tree type)
1464 for (field = TYPE_FIELDS (t); field; field = TREE_CHAIN (field))
1466 if (TREE_STATIC (field))
1468 if (TREE_CODE (field) != FIELD_DECL || DECL_ARTIFICIAL (field))
1471 /* If we find it directly, return the field. */
1472 if (DECL_NAME (field) == NULL_TREE
1473 && type == TYPE_MAIN_VARIANT (TREE_TYPE (field)))
1478 /* Otherwise, it could be nested, search harder. */
1479 if (DECL_NAME (field) == NULL_TREE
1480 && ANON_AGGR_TYPE_P (TREE_TYPE (field)))
1482 tree subfield = lookup_anon_field (TREE_TYPE (field), type);
1490 /* Build an expression representing OBJECT.MEMBER. OBJECT is an
1491 expression; MEMBER is a DECL or baselink. If ACCESS_PATH is
1492 non-NULL, it indicates the path to the base used to name MEMBER.
1493 If PRESERVE_REFERENCE is true, the expression returned will have
1494 REFERENCE_TYPE if the MEMBER does. Otherwise, the expression
1495 returned will have the type referred to by the reference.
1497 This function does not perform access control; that is either done
1498 earlier by the parser when the name of MEMBER is resolved to MEMBER
1499 itself, or later when overload resolution selects one of the
1500 functions indicated by MEMBER. */
1503 build_class_member_access_expr (tree object, tree member,
1504 tree access_path, bool preserve_reference)
1508 tree result = NULL_TREE;
1510 if (object == error_mark_node || member == error_mark_node)
1511 return error_mark_node;
1513 if (TREE_CODE (member) == PSEUDO_DTOR_EXPR)
1516 my_friendly_assert (DECL_P (member) || BASELINK_P (member),
1521 The type of the first expression shall be "class object" (of a
1523 object_type = TREE_TYPE (object);
1524 if (!complete_type_or_else (object_type, object))
1525 return error_mark_node;
1526 if (!CLASS_TYPE_P (object_type))
1528 error ("request for member `%D' in `%E', which is of non-class type `%T'",
1529 member, object, object_type);
1530 return error_mark_node;
1533 /* The standard does not seem to actually say that MEMBER must be a
1534 member of OBJECT_TYPE. However, that is clearly what is
1536 if (DECL_P (member))
1538 member_scope = DECL_CLASS_CONTEXT (member);
1540 if (TREE_DEPRECATED (member))
1541 warn_deprecated_use (member);
1544 member_scope = BINFO_TYPE (BASELINK_BINFO (member));
1545 /* If MEMBER is from an anonymous aggregate, MEMBER_SCOPE will
1546 presently be the anonymous union. Go outwards until we find a
1547 type related to OBJECT_TYPE. */
1548 while (ANON_AGGR_TYPE_P (member_scope)
1549 && !same_type_ignoring_top_level_qualifiers_p (member_scope,
1551 member_scope = TYPE_CONTEXT (member_scope);
1552 if (!member_scope || !DERIVED_FROM_P (member_scope, object_type))
1554 if (TREE_CODE (member) == FIELD_DECL)
1555 error ("invalid use of nonstatic data member '%E'", member);
1557 error ("`%D' is not a member of `%T'", member, object_type);
1558 return error_mark_node;
1561 /* Transform `(a, b).x' into `(*(a, &b)).x', `(a ? b : c).x' into
1562 `(*(a ? &b : &c)).x', and so on. A COND_EXPR is only an lvalue
1563 in the frontend; only _DECLs and _REFs are lvalues in the backend. */
1565 tree temp = unary_complex_lvalue (ADDR_EXPR, object);
1567 object = build_indirect_ref (temp, NULL);
1570 /* In [expr.ref], there is an explicit list of the valid choices for
1571 MEMBER. We check for each of those cases here. */
1572 if (TREE_CODE (member) == VAR_DECL)
1574 /* A static data member. */
1576 /* If OBJECT has side-effects, they are supposed to occur. */
1577 if (TREE_SIDE_EFFECTS (object))
1578 result = build (COMPOUND_EXPR, TREE_TYPE (result), object, result);
1580 else if (TREE_CODE (member) == FIELD_DECL)
1582 /* A non-static data member. */
1587 null_object_p = (TREE_CODE (object) == INDIRECT_REF
1588 && integer_zerop (TREE_OPERAND (object, 0)));
1590 /* Convert OBJECT to the type of MEMBER. */
1591 if (!same_type_p (TYPE_MAIN_VARIANT (object_type),
1592 TYPE_MAIN_VARIANT (member_scope)))
1597 binfo = lookup_base (access_path ? access_path : object_type,
1598 member_scope, ba_ignore, &kind);
1599 if (binfo == error_mark_node)
1600 return error_mark_node;
1602 /* It is invalid to try to get to a virtual base of a
1603 NULL object. The most common cause is invalid use of
1605 if (null_object_p && kind == bk_via_virtual)
1607 error ("invalid access to non-static data member `%D' of NULL object",
1609 error ("(perhaps the `offsetof' macro was used incorrectly)");
1610 return error_mark_node;
1613 /* Convert to the base. */
1614 object = build_base_path (PLUS_EXPR, object, binfo,
1616 /* If we found the base successfully then we should be able
1617 to convert to it successfully. */
1618 my_friendly_assert (object != error_mark_node,
1622 /* Complain about other invalid uses of offsetof, even though they will
1623 give the right answer. Note that we complain whether or not they
1624 actually used the offsetof macro, since there's no way to know at this
1625 point. So we just give a warning, instead of a pedwarn. */
1626 if (null_object_p && warn_invalid_offsetof
1627 && CLASSTYPE_NON_POD_P (object_type))
1629 warning ("invalid access to non-static data member `%D' of NULL object",
1631 warning ("(perhaps the `offsetof' macro was used incorrectly)");
1634 /* If MEMBER is from an anonymous aggregate, we have converted
1635 OBJECT so that it refers to the class containing the
1636 anonymous union. Generate a reference to the anonymous union
1637 itself, and recur to find MEMBER. */
1638 if (ANON_AGGR_TYPE_P (DECL_CONTEXT (member))
1639 /* When this code is called from build_field_call, the
1640 object already has the type of the anonymous union.
1641 That is because the COMPONENT_REF was already
1642 constructed, and was then disassembled before calling
1643 build_field_call. After the function-call code is
1644 cleaned up, this waste can be eliminated. */
1645 && (!same_type_ignoring_top_level_qualifiers_p
1646 (TREE_TYPE (object), DECL_CONTEXT (member))))
1648 tree anonymous_union;
1650 anonymous_union = lookup_anon_field (TREE_TYPE (object),
1651 DECL_CONTEXT (member));
1652 object = build_class_member_access_expr (object,
1654 /*access_path=*/NULL_TREE,
1655 preserve_reference);
1658 /* Compute the type of the field, as described in [expr.ref]. */
1659 type_quals = TYPE_UNQUALIFIED;
1660 member_type = TREE_TYPE (member);
1661 if (TREE_CODE (member_type) != REFERENCE_TYPE)
1663 type_quals = (cp_type_quals (member_type)
1664 | cp_type_quals (object_type));
1666 /* A field is const (volatile) if the enclosing object, or the
1667 field itself, is const (volatile). But, a mutable field is
1668 not const, even within a const object. */
1669 if (DECL_MUTABLE_P (member))
1670 type_quals &= ~TYPE_QUAL_CONST;
1671 member_type = cp_build_qualified_type (member_type, type_quals);
1674 result = fold (build (COMPONENT_REF, member_type, object, member));
1676 /* Mark the expression const or volatile, as appropriate. Even
1677 though we've dealt with the type above, we still have to mark the
1678 expression itself. */
1679 if (type_quals & TYPE_QUAL_CONST)
1680 TREE_READONLY (result) = 1;
1681 else if (type_quals & TYPE_QUAL_VOLATILE)
1682 TREE_THIS_VOLATILE (result) = 1;
1684 else if (BASELINK_P (member))
1686 /* The member is a (possibly overloaded) member function. */
1690 /* If the MEMBER is exactly one static member function, then we
1691 know the type of the expression. Otherwise, we must wait
1692 until overload resolution has been performed. */
1693 functions = BASELINK_FUNCTIONS (member);
1694 if (TREE_CODE (functions) == FUNCTION_DECL
1695 && DECL_STATIC_FUNCTION_P (functions))
1696 type = TREE_TYPE (functions);
1698 type = unknown_type_node;
1699 /* Note that we do not convert OBJECT to the BASELINK_BINFO
1700 base. That will happen when the function is called. */
1701 result = build (COMPONENT_REF, type, object, member);
1703 else if (TREE_CODE (member) == CONST_DECL)
1705 /* The member is an enumerator. */
1707 /* If OBJECT has side-effects, they are supposed to occur. */
1708 if (TREE_SIDE_EFFECTS (object))
1709 result = build (COMPOUND_EXPR, TREE_TYPE (result),
1714 error ("invalid use of `%D'", member);
1715 return error_mark_node;
1718 if (!preserve_reference)
1721 If E2 is declared to have type "reference to T", then ... the
1722 type of E1.E2 is T. */
1723 result = convert_from_reference (result);
1728 /* Return the destructor denoted by OBJECT.SCOPE::~DTOR_NAME, or, if
1729 SCOPE is NULL, by OBJECT.~DTOR_NAME. */
1732 lookup_destructor (tree object, tree scope, tree dtor_name)
1734 tree object_type = TREE_TYPE (object);
1735 tree dtor_type = TREE_OPERAND (dtor_name, 0);
1737 if (scope && !check_dtor_name (scope, dtor_name))
1739 error ("qualified type `%T' does not match destructor name `~%T'",
1741 return error_mark_node;
1743 if (!same_type_p (dtor_type, TYPE_MAIN_VARIANT (object_type)))
1745 error ("destructor name `%T' does not match type `%T' of expression",
1746 dtor_type, object_type);
1747 return error_mark_node;
1749 if (!TYPE_HAS_DESTRUCTOR (object_type))
1750 return build (PSEUDO_DTOR_EXPR, void_type_node, object, scope,
1752 return lookup_member (object_type, complete_dtor_identifier,
1753 /*protect=*/1, /*want_type=*/false);
1756 /* This function is called by the parser to process a class member
1757 access expression of the form OBJECT.NAME. NAME is a node used by
1758 the parser to represent a name; it is not yet a DECL. It may,
1759 however, be a BASELINK where the BASELINK_FUNCTIONS is a
1760 TEMPLATE_ID_EXPR. Templates must be looked up by the parser, and
1761 there is no reason to do the lookup twice, so the parser keeps the
1765 finish_class_member_access_expr (tree object, tree name)
1770 tree access_path = NULL_TREE;
1771 tree orig_object = object;
1772 tree orig_name = name;
1774 if (object == error_mark_node || name == error_mark_node)
1775 return error_mark_node;
1777 object_type = TREE_TYPE (object);
1779 if (processing_template_decl)
1781 if (/* If OBJECT_TYPE is dependent, so is OBJECT.NAME. */
1782 dependent_type_p (object_type)
1783 /* If NAME is "f<args>", where either 'f' or 'args' is
1784 dependent, then the expression is dependent. */
1785 || (TREE_CODE (name) == TEMPLATE_ID_EXPR
1786 && dependent_template_id_p (TREE_OPERAND (name, 0),
1787 TREE_OPERAND (name, 1)))
1788 /* If NAME is "T::X" where "T" is dependent, then the
1789 expression is dependent. */
1790 || (TREE_CODE (name) == SCOPE_REF
1791 && TYPE_P (TREE_OPERAND (name, 0))
1792 && dependent_type_p (TREE_OPERAND (name, 0))))
1793 return build_min_nt (COMPONENT_REF, object, name);
1794 object = build_non_dependent_expr (object);
1797 if (TREE_CODE (object_type) == REFERENCE_TYPE)
1799 object = convert_from_reference (object);
1800 object_type = TREE_TYPE (object);
1805 The type of the first expression shall be "class object" (of a
1807 if (!complete_type_or_else (object_type, object))
1808 return error_mark_node;
1809 if (!CLASS_TYPE_P (object_type))
1811 error ("request for member `%D' in `%E', which is of non-class type `%T'",
1812 name, object, object_type);
1813 return error_mark_node;
1816 if (BASELINK_P (name))
1818 /* A member function that has already been looked up. */
1819 my_friendly_assert ((TREE_CODE (BASELINK_FUNCTIONS (name))
1820 == TEMPLATE_ID_EXPR),
1826 bool is_template_id = false;
1827 tree template_args = NULL_TREE;
1830 if (TREE_CODE (name) == TEMPLATE_ID_EXPR)
1832 is_template_id = true;
1833 template_args = TREE_OPERAND (name, 1);
1834 name = TREE_OPERAND (name, 0);
1837 if (TREE_CODE (name) == SCOPE_REF)
1839 /* A qualified name. The qualifying class or namespace `S' has
1840 already been looked up; it is either a TYPE or a
1841 NAMESPACE_DECL. The member name is either an IDENTIFIER_NODE
1842 or a BIT_NOT_EXPR. */
1843 scope = TREE_OPERAND (name, 0);
1844 name = TREE_OPERAND (name, 1);
1845 my_friendly_assert ((CLASS_TYPE_P (scope)
1846 || TREE_CODE (scope) == NAMESPACE_DECL),
1848 my_friendly_assert ((TREE_CODE (name) == IDENTIFIER_NODE
1849 || TREE_CODE (name) == BIT_NOT_EXPR),
1852 /* If SCOPE is a namespace, then the qualified name does not
1853 name a member of OBJECT_TYPE. */
1854 if (TREE_CODE (scope) == NAMESPACE_DECL)
1856 error ("`%D::%D' is not a member of `%T'",
1857 scope, name, object_type);
1858 return error_mark_node;
1861 /* Find the base of OBJECT_TYPE corresponding to SCOPE. */
1862 access_path = lookup_base (object_type, scope, ba_check, NULL);
1863 if (!access_path || access_path == error_mark_node)
1864 return error_mark_node;
1869 access_path = object_type;
1872 if (TREE_CODE (name) == BIT_NOT_EXPR)
1873 member = lookup_destructor (object, scope, name);
1876 /* Look up the member. */
1877 member = lookup_member (access_path, name, /*protect=*/1,
1878 /*want_type=*/false);
1879 if (member == NULL_TREE)
1881 error ("'%D' has no member named '%E'", object_type, name);
1882 return error_mark_node;
1884 if (member == error_mark_node)
1885 return error_mark_node;
1890 tree template = member;
1892 if (BASELINK_P (template))
1893 template = lookup_template_function (template, template_args);
1896 error ("`%D' is not a member template function", name);
1897 return error_mark_node;
1902 if (TREE_DEPRECATED (member))
1903 warn_deprecated_use (member);
1905 expr = build_class_member_access_expr (object, member, access_path,
1906 /*preserve_reference=*/false);
1907 if (processing_template_decl && expr != error_mark_node)
1908 return build_min (COMPONENT_REF, TREE_TYPE (expr), orig_object,
1913 /* Return an expression for the MEMBER_NAME field in the internal
1914 representation of PTRMEM, a pointer-to-member function. (Each
1915 pointer-to-member function type gets its own RECORD_TYPE so it is
1916 more convenient to access the fields by name than by FIELD_DECL.)
1917 This routine converts the NAME to a FIELD_DECL and then creates the
1918 node for the complete expression. */
1921 build_ptrmemfunc_access_expr (tree ptrmem, tree member_name)
1927 /* This code is a stripped down version of
1928 build_class_member_access_expr. It does not work to use that
1929 routine directly because it expects the object to be of class
1931 ptrmem_type = TREE_TYPE (ptrmem);
1932 my_friendly_assert (TYPE_PTRMEMFUNC_P (ptrmem_type), 20020804);
1933 member = lookup_member (ptrmem_type, member_name, /*protect=*/0,
1934 /*want_type=*/false);
1935 member_type = cp_build_qualified_type (TREE_TYPE (member),
1936 cp_type_quals (ptrmem_type));
1937 return fold (build (COMPONENT_REF, member_type, ptrmem, member));
1940 /* Given an expression PTR for a pointer, return an expression
1941 for the value pointed to.
1942 ERRORSTRING is the name of the operator to appear in error messages.
1944 This function may need to overload OPERATOR_FNNAME.
1945 Must also handle REFERENCE_TYPEs for C++. */
1948 build_x_indirect_ref (tree expr, const char *errorstring)
1950 tree orig_expr = expr;
1953 if (processing_template_decl)
1955 if (type_dependent_expression_p (expr))
1956 return build_min_nt (INDIRECT_REF, expr);
1957 expr = build_non_dependent_expr (expr);
1960 rval = build_new_op (INDIRECT_REF, LOOKUP_NORMAL, expr, NULL_TREE,
1963 rval = build_indirect_ref (expr, errorstring);
1965 if (processing_template_decl && rval != error_mark_node)
1966 return build_min (INDIRECT_REF, TREE_TYPE (rval), orig_expr);
1972 build_indirect_ref (tree ptr, const char *errorstring)
1974 register tree pointer, type;
1976 if (ptr == error_mark_node)
1977 return error_mark_node;
1979 if (ptr == current_class_ptr)
1980 return current_class_ref;
1982 pointer = (TREE_CODE (TREE_TYPE (ptr)) == REFERENCE_TYPE
1983 ? ptr : decay_conversion (ptr));
1984 type = TREE_TYPE (pointer);
1986 if (TYPE_PTR_P (type) || TREE_CODE (type) == REFERENCE_TYPE)
1990 If the type of the expression is "pointer to T," the type
1991 of the result is "T."
1993 We must use the canonical variant because certain parts of
1994 the back end, like fold, do pointer comparisons between
1996 tree t = canonical_type_variant (TREE_TYPE (type));
1998 if (VOID_TYPE_P (t))
2000 /* A pointer to incomplete type (other than cv void) can be
2001 dereferenced [expr.unary.op]/1 */
2002 error ("`%T' is not a pointer-to-object type", type);
2003 return error_mark_node;
2005 else if (TREE_CODE (pointer) == ADDR_EXPR
2006 && same_type_p (t, TREE_TYPE (TREE_OPERAND (pointer, 0))))
2007 /* The POINTER was something like `&x'. We simplify `*&x' to
2009 return TREE_OPERAND (pointer, 0);
2012 tree ref = build1 (INDIRECT_REF, t, pointer);
2014 /* We *must* set TREE_READONLY when dereferencing a pointer to const,
2015 so that we get the proper error message if the result is used
2016 to assign to. Also, &* is supposed to be a no-op. */
2017 TREE_READONLY (ref) = CP_TYPE_CONST_P (t);
2018 TREE_THIS_VOLATILE (ref) = CP_TYPE_VOLATILE_P (t);
2019 TREE_SIDE_EFFECTS (ref)
2020 = (TREE_THIS_VOLATILE (ref) || TREE_SIDE_EFFECTS (pointer));
2024 /* `pointer' won't be an error_mark_node if we were given a
2025 pointer to member, so it's cool to check for this here. */
2026 else if (TYPE_PTR_TO_MEMBER_P (type))
2027 error ("invalid use of `%s' on pointer to member", errorstring);
2028 else if (pointer != error_mark_node)
2031 error ("invalid type argument of `%s'", errorstring);
2033 error ("invalid type argument");
2035 return error_mark_node;
2038 /* This handles expressions of the form "a[i]", which denotes
2041 This is logically equivalent in C to *(a+i), but we may do it differently.
2042 If A is a variable or a member, we generate a primitive ARRAY_REF.
2043 This avoids forcing the array out of registers, and can work on
2044 arrays that are not lvalues (for example, members of structures returned
2047 If INDEX is of some user-defined type, it must be converted to
2048 integer type. Otherwise, to make a compatible PLUS_EXPR, it
2049 will inherit the type of the array, which will be some pointer type. */
2052 build_array_ref (tree array, tree idx)
2056 error ("subscript missing in array reference");
2057 return error_mark_node;
2060 if (TREE_TYPE (array) == error_mark_node
2061 || TREE_TYPE (idx) == error_mark_node)
2062 return error_mark_node;
2064 /* If ARRAY is a COMPOUND_EXPR or COND_EXPR, move our reference
2066 switch (TREE_CODE (array))
2070 tree value = build_array_ref (TREE_OPERAND (array, 1), idx);
2071 return build (COMPOUND_EXPR, TREE_TYPE (value),
2072 TREE_OPERAND (array, 0), value);
2076 return build_conditional_expr
2077 (TREE_OPERAND (array, 0),
2078 build_array_ref (TREE_OPERAND (array, 1), idx),
2079 build_array_ref (TREE_OPERAND (array, 2), idx));
2085 if (TREE_CODE (TREE_TYPE (array)) == ARRAY_TYPE
2086 && TREE_CODE (array) != INDIRECT_REF)
2090 /* Subscripting with type char is likely to lose
2091 on a machine where chars are signed.
2092 So warn on any machine, but optionally.
2093 Don't warn for unsigned char since that type is safe.
2094 Don't warn for signed char because anyone who uses that
2095 must have done so deliberately. */
2096 if (warn_char_subscripts
2097 && TYPE_MAIN_VARIANT (TREE_TYPE (idx)) == char_type_node)
2098 warning ("array subscript has type `char'");
2100 if (!INTEGRAL_OR_ENUMERATION_TYPE_P (TREE_TYPE (idx)))
2102 error ("array subscript is not an integer");
2103 return error_mark_node;
2106 /* Apply integral promotions *after* noticing character types.
2107 (It is unclear why we do these promotions -- the standard
2108 does not say that we should. In fact, the natual thing would
2109 seem to be to convert IDX to ptrdiff_t; we're performing
2110 pointer arithmetic.) */
2111 idx = perform_integral_promotions (idx);
2113 /* An array that is indexed by a non-constant
2114 cannot be stored in a register; we must be able to do
2115 address arithmetic on its address.
2116 Likewise an array of elements of variable size. */
2117 if (TREE_CODE (idx) != INTEGER_CST
2118 || (COMPLETE_TYPE_P (TREE_TYPE (TREE_TYPE (array)))
2119 && (TREE_CODE (TYPE_SIZE (TREE_TYPE (TREE_TYPE (array))))
2122 if (!cxx_mark_addressable (array))
2123 return error_mark_node;
2126 /* An array that is indexed by a constant value which is not within
2127 the array bounds cannot be stored in a register either; because we
2128 would get a crash in store_bit_field/extract_bit_field when trying
2129 to access a non-existent part of the register. */
2130 if (TREE_CODE (idx) == INTEGER_CST
2131 && TYPE_VALUES (TREE_TYPE (array))
2132 && ! int_fits_type_p (idx, TYPE_VALUES (TREE_TYPE (array))))
2134 if (!cxx_mark_addressable (array))
2135 return error_mark_node;
2138 if (pedantic && !lvalue_p (array))
2139 pedwarn ("ISO C++ forbids subscripting non-lvalue array");
2141 /* Note in C++ it is valid to subscript a `register' array, since
2142 it is valid to take the address of something with that
2143 storage specification. */
2147 while (TREE_CODE (foo) == COMPONENT_REF)
2148 foo = TREE_OPERAND (foo, 0);
2149 if (TREE_CODE (foo) == VAR_DECL && DECL_REGISTER (foo))
2150 warning ("subscripting array declared `register'");
2153 type = TREE_TYPE (TREE_TYPE (array));
2154 rval = build (ARRAY_REF, type, array, idx);
2155 /* Array ref is const/volatile if the array elements are
2156 or if the array is.. */
2157 TREE_READONLY (rval)
2158 |= (CP_TYPE_CONST_P (type) | TREE_READONLY (array));
2159 TREE_SIDE_EFFECTS (rval)
2160 |= (CP_TYPE_VOLATILE_P (type) | TREE_SIDE_EFFECTS (array));
2161 TREE_THIS_VOLATILE (rval)
2162 |= (CP_TYPE_VOLATILE_P (type) | TREE_THIS_VOLATILE (array));
2163 return require_complete_type (fold (rval));
2167 tree ar = default_conversion (array);
2168 tree ind = default_conversion (idx);
2170 /* Put the integer in IND to simplify error checking. */
2171 if (TREE_CODE (TREE_TYPE (ar)) == INTEGER_TYPE)
2178 if (ar == error_mark_node)
2181 if (TREE_CODE (TREE_TYPE (ar)) != POINTER_TYPE)
2183 error ("subscripted value is neither array nor pointer");
2184 return error_mark_node;
2186 if (TREE_CODE (TREE_TYPE (ind)) != INTEGER_TYPE)
2188 error ("array subscript is not an integer");
2189 return error_mark_node;
2192 return build_indirect_ref (cp_build_binary_op (PLUS_EXPR, ar, ind),
2197 /* Resolve a pointer to member function. INSTANCE is the object
2198 instance to use, if the member points to a virtual member.
2200 This used to avoid checking for virtual functions if basetype
2201 has no virtual functions, according to an earlier ANSI draft.
2202 With the final ISO C++ rules, such an optimization is
2203 incorrect: A pointer to a derived member can be static_cast
2204 to pointer-to-base-member, as long as the dynamic object
2205 later has the right member. */
2208 get_member_function_from_ptrfunc (tree *instance_ptrptr, tree function)
2210 if (TREE_CODE (function) == OFFSET_REF)
2211 function = TREE_OPERAND (function, 1);
2213 if (TYPE_PTRMEMFUNC_P (TREE_TYPE (function)))
2215 tree idx, delta, e1, e2, e3, vtbl, basetype;
2216 tree fntype = TYPE_PTRMEMFUNC_FN_TYPE (TREE_TYPE (function));
2218 tree instance_ptr = *instance_ptrptr;
2219 tree instance_save_expr = 0;
2220 if (instance_ptr == error_mark_node)
2222 if (TREE_CODE (function) == PTRMEM_CST)
2224 /* Extracting the function address from a pmf is only
2225 allowed with -Wno-pmf-conversions. It only works for
2227 e1 = build_addr_func (PTRMEM_CST_MEMBER (function));
2228 e1 = convert (fntype, e1);
2233 error ("object missing in use of `%E'", function);
2234 return error_mark_node;
2238 if (TREE_SIDE_EFFECTS (instance_ptr))
2239 instance_ptr = instance_save_expr = save_expr (instance_ptr);
2241 if (TREE_SIDE_EFFECTS (function))
2242 function = save_expr (function);
2244 /* Start by extracting all the information from the PMF itself. */
2245 e3 = PFN_FROM_PTRMEMFUNC (function);
2246 delta = build_ptrmemfunc_access_expr (function, delta_identifier);
2247 idx = build1 (NOP_EXPR, vtable_index_type, e3);
2248 switch (TARGET_PTRMEMFUNC_VBIT_LOCATION)
2250 case ptrmemfunc_vbit_in_pfn:
2251 e1 = cp_build_binary_op (BIT_AND_EXPR, idx, integer_one_node);
2252 idx = cp_build_binary_op (MINUS_EXPR, idx, integer_one_node);
2255 case ptrmemfunc_vbit_in_delta:
2256 e1 = cp_build_binary_op (BIT_AND_EXPR, delta, integer_one_node);
2257 delta = cp_build_binary_op (RSHIFT_EXPR, delta, integer_one_node);
2264 /* Convert down to the right base before using the instance. First
2266 basetype = TYPE_METHOD_BASETYPE (TREE_TYPE (fntype));
2267 basetype = lookup_base (TREE_TYPE (TREE_TYPE (instance_ptr)),
2268 basetype, ba_check, NULL);
2269 instance_ptr = build_base_path (PLUS_EXPR, instance_ptr, basetype, 1);
2270 if (instance_ptr == error_mark_node)
2271 return error_mark_node;
2272 /* ...and then the delta in the PMF. */
2273 instance_ptr = build (PLUS_EXPR, TREE_TYPE (instance_ptr),
2274 instance_ptr, delta);
2276 /* Hand back the adjusted 'this' argument to our caller. */
2277 *instance_ptrptr = instance_ptr;
2279 /* Next extract the vtable pointer from the object. */
2280 vtbl = build1 (NOP_EXPR, build_pointer_type (vtbl_ptr_type_node),
2282 vtbl = build_indirect_ref (vtbl, NULL);
2284 /* Finally, extract the function pointer from the vtable. */
2285 e2 = fold (build (PLUS_EXPR, TREE_TYPE (vtbl), vtbl, idx));
2286 e2 = build_indirect_ref (e2, NULL);
2287 TREE_CONSTANT (e2) = 1;
2289 /* When using function descriptors, the address of the
2290 vtable entry is treated as a function pointer. */
2291 if (TARGET_VTABLE_USES_DESCRIPTORS)
2292 e2 = build1 (NOP_EXPR, TREE_TYPE (e2),
2293 build_unary_op (ADDR_EXPR, e2, /*noconvert=*/1));
2295 TREE_TYPE (e2) = TREE_TYPE (e3);
2296 e1 = build_conditional_expr (e1, e2, e3);
2298 /* Make sure this doesn't get evaluated first inside one of the
2299 branches of the COND_EXPR. */
2300 if (instance_save_expr)
2301 e1 = build (COMPOUND_EXPR, TREE_TYPE (e1),
2302 instance_save_expr, e1);
2310 build_function_call (tree function, tree params)
2312 register tree fntype, fndecl;
2313 register tree coerced_params;
2315 tree name = NULL_TREE, assembler_name = NULL_TREE;
2317 tree original = function;
2319 /* build_c_cast puts on a NOP_EXPR to make the result not an lvalue.
2320 Strip such NOP_EXPRs, since FUNCTION is used in non-lvalue context. */
2321 if (TREE_CODE (function) == NOP_EXPR
2322 && TREE_TYPE (function) == TREE_TYPE (TREE_OPERAND (function, 0)))
2323 function = TREE_OPERAND (function, 0);
2325 if (TREE_CODE (function) == FUNCTION_DECL)
2327 name = DECL_NAME (function);
2328 assembler_name = DECL_ASSEMBLER_NAME (function);
2330 mark_used (function);
2333 /* Convert anything with function type to a pointer-to-function. */
2334 if (pedantic && DECL_MAIN_P (function))
2335 pedwarn ("ISO C++ forbids calling `::main' from within program");
2337 /* Differs from default_conversion by not setting TREE_ADDRESSABLE
2338 (because calling an inline function does not mean the function
2339 needs to be separately compiled). */
2341 if (DECL_INLINE (function))
2342 function = inline_conversion (function);
2344 function = build_addr_func (function);
2350 function = build_addr_func (function);
2353 if (function == error_mark_node)
2354 return error_mark_node;
2356 fntype = TREE_TYPE (function);
2358 if (TYPE_PTRMEMFUNC_P (fntype))
2360 error ("must use .* or ->* to call pointer-to-member function in `%E (...)'",
2362 return error_mark_node;
2365 is_method = (TREE_CODE (fntype) == POINTER_TYPE
2366 && TREE_CODE (TREE_TYPE (fntype)) == METHOD_TYPE);
2368 if (!((TREE_CODE (fntype) == POINTER_TYPE
2369 && TREE_CODE (TREE_TYPE (fntype)) == FUNCTION_TYPE)
2371 || TREE_CODE (function) == TEMPLATE_ID_EXPR))
2373 error ("`%E' cannot be used as a function", original);
2374 return error_mark_node;
2377 /* fntype now gets the type of function pointed to. */
2378 fntype = TREE_TYPE (fntype);
2380 /* Convert the parameters to the types declared in the
2381 function prototype, or apply default promotions. */
2383 coerced_params = convert_arguments (TYPE_ARG_TYPES (fntype),
2384 params, fndecl, LOOKUP_NORMAL);
2385 if (coerced_params == error_mark_node)
2386 return error_mark_node;
2388 /* Check for errors in format strings. */
2391 check_function_format (NULL, TYPE_ATTRIBUTES (fntype), coerced_params);
2393 /* Recognize certain built-in functions so we can make tree-codes
2394 other than CALL_EXPR. We do this when it enables fold-const.c
2395 to do something useful. */
2397 if (TREE_CODE (function) == ADDR_EXPR
2398 && TREE_CODE (TREE_OPERAND (function, 0)) == FUNCTION_DECL
2399 && DECL_BUILT_IN (TREE_OPERAND (function, 0)))
2401 result = expand_tree_builtin (TREE_OPERAND (function, 0),
2402 params, coerced_params);
2407 return build_cxx_call (function, params, coerced_params);
2410 /* Convert the actual parameter expressions in the list VALUES
2411 to the types in the list TYPELIST.
2412 If parmdecls is exhausted, or when an element has NULL as its type,
2413 perform the default conversions.
2415 NAME is an IDENTIFIER_NODE or 0. It is used only for error messages.
2417 This is also where warnings about wrong number of args are generated.
2419 Return a list of expressions for the parameters as converted.
2421 Both VALUES and the returned value are chains of TREE_LIST nodes
2422 with the elements of the list in the TREE_VALUE slots of those nodes.
2424 In C++, unspecified trailing parameters can be filled in with their
2425 default arguments, if such were specified. Do so here. */
2428 convert_arguments (tree typelist, tree values, tree fndecl, int flags)
2430 register tree typetail, valtail;
2431 register tree result = NULL_TREE;
2432 const char *called_thing = 0;
2435 /* Argument passing is always copy-initialization. */
2436 flags |= LOOKUP_ONLYCONVERTING;
2440 if (TREE_CODE (TREE_TYPE (fndecl)) == METHOD_TYPE)
2442 if (DECL_NAME (fndecl) == NULL_TREE
2443 || IDENTIFIER_HAS_TYPE_VALUE (DECL_NAME (fndecl)))
2444 called_thing = "constructor";
2446 called_thing = "member function";
2449 called_thing = "function";
2452 for (valtail = values, typetail = typelist;
2454 valtail = TREE_CHAIN (valtail), i++)
2456 register tree type = typetail ? TREE_VALUE (typetail) : 0;
2457 register tree val = TREE_VALUE (valtail);
2459 if (val == error_mark_node)
2460 return error_mark_node;
2462 if (type == void_type_node)
2466 cp_error_at ("too many arguments to %s `%+#D'", called_thing,
2468 error ("at this point in file");
2471 error ("too many arguments to function");
2472 /* In case anybody wants to know if this argument
2475 TREE_TYPE (tree_last (result)) = error_mark_node;
2479 /* build_c_cast puts on a NOP_EXPR to make the result not an lvalue.
2480 Strip such NOP_EXPRs, since VAL is used in non-lvalue context. */
2481 if (TREE_CODE (val) == NOP_EXPR
2482 && TREE_TYPE (val) == TREE_TYPE (TREE_OPERAND (val, 0))
2483 && (type == 0 || TREE_CODE (type) != REFERENCE_TYPE))
2484 val = TREE_OPERAND (val, 0);
2486 if (type == 0 || TREE_CODE (type) != REFERENCE_TYPE)
2488 if (TREE_CODE (TREE_TYPE (val)) == ARRAY_TYPE
2489 || TREE_CODE (TREE_TYPE (val)) == FUNCTION_TYPE
2490 || TREE_CODE (TREE_TYPE (val)) == METHOD_TYPE)
2491 val = decay_conversion (val);
2494 if (val == error_mark_node)
2495 return error_mark_node;
2499 /* Formal parm type is specified by a function prototype. */
2502 if (!COMPLETE_TYPE_P (complete_type (type)))
2504 error ("parameter type of called function is incomplete");
2509 parmval = convert_for_initialization
2510 (NULL_TREE, type, val, flags,
2511 "argument passing", fndecl, i);
2512 parmval = convert_for_arg_passing (type, parmval);
2515 if (parmval == error_mark_node)
2516 return error_mark_node;
2518 result = tree_cons (NULL_TREE, parmval, result);
2522 if (TREE_CODE (TREE_TYPE (val)) == REFERENCE_TYPE)
2523 val = convert_from_reference (val);
2525 if (fndecl && DECL_BUILT_IN (fndecl)
2526 && DECL_FUNCTION_CODE (fndecl) == BUILT_IN_CONSTANT_P)
2527 /* Don't do ellipsis conversion for __built_in_constant_p
2528 as this will result in spurious warnings for non-POD
2530 val = require_complete_type (val);
2532 val = convert_arg_to_ellipsis (val);
2534 result = tree_cons (NULL_TREE, val, result);
2538 typetail = TREE_CHAIN (typetail);
2541 if (typetail != 0 && typetail != void_list_node)
2543 /* See if there are default arguments that can be used */
2544 if (TREE_PURPOSE (typetail)
2545 && TREE_CODE (TREE_PURPOSE (typetail)) != DEFAULT_ARG)
2547 for (; typetail != void_list_node; ++i)
2550 = convert_default_arg (TREE_VALUE (typetail),
2551 TREE_PURPOSE (typetail),
2554 if (parmval == error_mark_node)
2555 return error_mark_node;
2557 result = tree_cons (0, parmval, result);
2558 typetail = TREE_CHAIN (typetail);
2559 /* ends with `...'. */
2560 if (typetail == NULL_TREE)
2568 cp_error_at ("too few arguments to %s `%+#D'",
2569 called_thing, fndecl);
2570 error ("at this point in file");
2573 error ("too few arguments to function");
2574 return error_mark_list;
2578 return nreverse (result);
2581 /* Build a binary-operation expression, after performing default
2582 conversions on the operands. CODE is the kind of expression to build. */
2585 build_x_binary_op (enum tree_code code, tree arg1, tree arg2)
2594 if (processing_template_decl)
2596 if (type_dependent_expression_p (arg1)
2597 || type_dependent_expression_p (arg2))
2598 return build_min_nt (code, arg1, arg2);
2599 arg1 = build_non_dependent_expr (arg1);
2600 arg2 = build_non_dependent_expr (arg2);
2603 if (code == DOTSTAR_EXPR)
2604 expr = build_m_component_ref (arg1, arg2);
2606 expr = build_new_op (code, LOOKUP_NORMAL, arg1, arg2, NULL_TREE);
2608 if (processing_template_decl && expr != error_mark_node)
2609 return build_min (code, TREE_TYPE (expr), orig_arg1, orig_arg2);
2614 /* Build a binary-operation expression without default conversions.
2615 CODE is the kind of expression to build.
2616 This function differs from `build' in several ways:
2617 the data type of the result is computed and recorded in it,
2618 warnings are generated if arg data types are invalid,
2619 special handling for addition and subtraction of pointers is known,
2620 and some optimization is done (operations on narrow ints
2621 are done in the narrower type when that gives the same result).
2622 Constant folding is also done before the result is returned.
2624 Note that the operands will never have enumeral types
2625 because either they have just had the default conversions performed
2626 or they have both just been converted to some other type in which
2627 the arithmetic is to be done.
2629 C++: must do special pointer arithmetic when implementing
2630 multiple inheritance, and deal with pointer to member functions. */
2633 build_binary_op (enum tree_code code, tree orig_op0, tree orig_op1,
2634 int convert_p ATTRIBUTE_UNUSED)
2637 register enum tree_code code0, code1;
2640 /* Expression code to give to the expression when it is built.
2641 Normally this is CODE, which is what the caller asked for,
2642 but in some special cases we change it. */
2643 register enum tree_code resultcode = code;
2645 /* Data type in which the computation is to be performed.
2646 In the simplest cases this is the common type of the arguments. */
2647 register tree result_type = NULL;
2649 /* Nonzero means operands have already been type-converted
2650 in whatever way is necessary.
2651 Zero means they need to be converted to RESULT_TYPE. */
2654 /* Nonzero means create the expression with this type, rather than
2656 tree build_type = 0;
2658 /* Nonzero means after finally constructing the expression
2659 convert it to this type. */
2660 tree final_type = 0;
2662 /* Nonzero if this is an operation like MIN or MAX which can
2663 safely be computed in short if both args are promoted shorts.
2664 Also implies COMMON.
2665 -1 indicates a bitwise operation; this makes a difference
2666 in the exact conditions for when it is safe to do the operation
2667 in a narrower mode. */
2670 /* Nonzero if this is a comparison operation;
2671 if both args are promoted shorts, compare the original shorts.
2672 Also implies COMMON. */
2673 int short_compare = 0;
2675 /* Nonzero if this is a right-shift operation, which can be computed on the
2676 original short and then promoted if the operand is a promoted short. */
2677 int short_shift = 0;
2679 /* Nonzero means set RESULT_TYPE to the common type of the args. */
2682 /* Apply default conversions. */
2686 if (code == TRUTH_AND_EXPR || code == TRUTH_ANDIF_EXPR
2687 || code == TRUTH_OR_EXPR || code == TRUTH_ORIF_EXPR
2688 || code == TRUTH_XOR_EXPR)
2690 if (!really_overloaded_fn (op0))
2691 op0 = decay_conversion (op0);
2692 if (!really_overloaded_fn (op1))
2693 op1 = decay_conversion (op1);
2697 if (!really_overloaded_fn (op0))
2698 op0 = default_conversion (op0);
2699 if (!really_overloaded_fn (op1))
2700 op1 = default_conversion (op1);
2703 /* Strip NON_LVALUE_EXPRs, etc., since we aren't using as an lvalue. */
2704 STRIP_TYPE_NOPS (op0);
2705 STRIP_TYPE_NOPS (op1);
2707 /* DTRT if one side is an overloaded function, but complain about it. */
2708 if (type_unknown_p (op0))
2710 tree t = instantiate_type (TREE_TYPE (op1), op0, tf_none);
2711 if (t != error_mark_node)
2713 pedwarn ("assuming cast to type `%T' from overloaded function",
2718 if (type_unknown_p (op1))
2720 tree t = instantiate_type (TREE_TYPE (op0), op1, tf_none);
2721 if (t != error_mark_node)
2723 pedwarn ("assuming cast to type `%T' from overloaded function",
2729 type0 = TREE_TYPE (op0);
2730 type1 = TREE_TYPE (op1);
2732 /* The expression codes of the data types of the arguments tell us
2733 whether the arguments are integers, floating, pointers, etc. */
2734 code0 = TREE_CODE (type0);
2735 code1 = TREE_CODE (type1);
2737 /* If an error was already reported for one of the arguments,
2738 avoid reporting another error. */
2740 if (code0 == ERROR_MARK || code1 == ERROR_MARK)
2741 return error_mark_node;
2746 /* Handle the pointer + int case. */
2747 if (code0 == POINTER_TYPE && code1 == INTEGER_TYPE)
2748 return cp_pointer_int_sum (PLUS_EXPR, op0, op1);
2749 else if (code1 == POINTER_TYPE && code0 == INTEGER_TYPE)
2750 return cp_pointer_int_sum (PLUS_EXPR, op1, op0);
2756 /* Subtraction of two similar pointers.
2757 We must subtract them as integers, then divide by object size. */
2758 if (code0 == POINTER_TYPE && code1 == POINTER_TYPE
2759 && same_type_ignoring_top_level_qualifiers_p (TREE_TYPE (type0),
2761 return pointer_diff (op0, op1, common_type (type0, type1));
2762 /* Handle pointer minus int. Just like pointer plus int. */
2763 else if (code0 == POINTER_TYPE && code1 == INTEGER_TYPE)
2764 return cp_pointer_int_sum (MINUS_EXPR, op0, op1);
2773 case TRUNC_DIV_EXPR:
2775 case FLOOR_DIV_EXPR:
2776 case ROUND_DIV_EXPR:
2777 case EXACT_DIV_EXPR:
2778 if ((code0 == INTEGER_TYPE || code0 == REAL_TYPE
2779 || code0 == COMPLEX_TYPE)
2780 && (code1 == INTEGER_TYPE || code1 == REAL_TYPE
2781 || code1 == COMPLEX_TYPE))
2783 if (TREE_CODE (op1) == INTEGER_CST && integer_zerop (op1))
2784 warning ("division by zero in `%E / 0'", op0);
2785 else if (TREE_CODE (op1) == REAL_CST && real_zerop (op1))
2786 warning ("division by zero in `%E / 0.'", op0);
2788 if (!(code0 == INTEGER_TYPE && code1 == INTEGER_TYPE))
2789 resultcode = RDIV_EXPR;
2791 /* When dividing two signed integers, we have to promote to int.
2792 unless we divide by a constant != -1. Note that default
2793 conversion will have been performed on the operands at this
2794 point, so we have to dig out the original type to find out if
2796 shorten = ((TREE_CODE (op0) == NOP_EXPR
2797 && TREE_UNSIGNED (TREE_TYPE (TREE_OPERAND (op0, 0))))
2798 || (TREE_CODE (op1) == INTEGER_CST
2799 && ! integer_all_onesp (op1)));
2806 case BIT_ANDTC_EXPR:
2809 if (code0 == INTEGER_TYPE && code1 == INTEGER_TYPE)
2813 case TRUNC_MOD_EXPR:
2814 case FLOOR_MOD_EXPR:
2815 if (code1 == INTEGER_TYPE && integer_zerop (op1))
2816 warning ("division by zero in `%E %% 0'", op0);
2817 else if (code1 == REAL_TYPE && real_zerop (op1))
2818 warning ("division by zero in `%E %% 0.'", op0);
2820 if (code0 == INTEGER_TYPE && code1 == INTEGER_TYPE)
2822 /* Although it would be tempting to shorten always here, that loses
2823 on some targets, since the modulo instruction is undefined if the
2824 quotient can't be represented in the computation mode. We shorten
2825 only if unsigned or if dividing by something we know != -1. */
2826 shorten = ((TREE_CODE (op0) == NOP_EXPR
2827 && TREE_UNSIGNED (TREE_TYPE (TREE_OPERAND (op0, 0))))
2828 || (TREE_CODE (op1) == INTEGER_CST
2829 && ! integer_all_onesp (op1)));
2834 case TRUTH_ANDIF_EXPR:
2835 case TRUTH_ORIF_EXPR:
2836 case TRUTH_AND_EXPR:
2838 result_type = boolean_type_node;
2841 /* Shift operations: result has same type as first operand;
2842 always convert second operand to int.
2843 Also set SHORT_SHIFT if shifting rightward. */
2846 if (code0 == INTEGER_TYPE && code1 == INTEGER_TYPE)
2848 result_type = type0;
2849 if (TREE_CODE (op1) == INTEGER_CST)
2851 if (tree_int_cst_lt (op1, integer_zero_node))
2852 warning ("right shift count is negative");
2855 if (! integer_zerop (op1))
2857 if (compare_tree_int (op1, TYPE_PRECISION (type0)) >= 0)
2858 warning ("right shift count >= width of type");
2861 /* Convert the shift-count to an integer, regardless of
2862 size of value being shifted. */
2863 if (TYPE_MAIN_VARIANT (TREE_TYPE (op1)) != integer_type_node)
2864 op1 = cp_convert (integer_type_node, op1);
2865 /* Avoid converting op1 to result_type later. */
2871 if (code0 == INTEGER_TYPE && code1 == INTEGER_TYPE)
2873 result_type = type0;
2874 if (TREE_CODE (op1) == INTEGER_CST)
2876 if (tree_int_cst_lt (op1, integer_zero_node))
2877 warning ("left shift count is negative");
2878 else if (compare_tree_int (op1, TYPE_PRECISION (type0)) >= 0)
2879 warning ("left shift count >= width of type");
2881 /* Convert the shift-count to an integer, regardless of
2882 size of value being shifted. */
2883 if (TYPE_MAIN_VARIANT (TREE_TYPE (op1)) != integer_type_node)
2884 op1 = cp_convert (integer_type_node, op1);
2885 /* Avoid converting op1 to result_type later. */
2892 if (code0 == INTEGER_TYPE && code1 == INTEGER_TYPE)
2894 result_type = type0;
2895 if (TREE_CODE (op1) == INTEGER_CST)
2897 if (tree_int_cst_lt (op1, integer_zero_node))
2898 warning ("%s rotate count is negative",
2899 (code == LROTATE_EXPR) ? "left" : "right");
2900 else if (compare_tree_int (op1, TYPE_PRECISION (type0)) >= 0)
2901 warning ("%s rotate count >= width of type",
2902 (code == LROTATE_EXPR) ? "left" : "right");
2904 /* Convert the shift-count to an integer, regardless of
2905 size of value being shifted. */
2906 if (TYPE_MAIN_VARIANT (TREE_TYPE (op1)) != integer_type_node)
2907 op1 = cp_convert (integer_type_node, op1);
2913 if (warn_float_equal && (code0 == REAL_TYPE || code1 == REAL_TYPE))
2914 warning ("comparing floating point with == or != is unsafe");
2916 build_type = boolean_type_node;
2917 if ((code0 == INTEGER_TYPE || code0 == REAL_TYPE
2918 || code0 == COMPLEX_TYPE)
2919 && (code1 == INTEGER_TYPE || code1 == REAL_TYPE
2920 || code1 == COMPLEX_TYPE))
2922 else if ((code0 == POINTER_TYPE && code1 == POINTER_TYPE)
2923 || (TYPE_PTRMEM_P (type0) && TYPE_PTRMEM_P (type1)))
2924 result_type = composite_pointer_type (type0, type1, op0, op1,
2926 else if ((code0 == POINTER_TYPE || TYPE_PTRMEM_P (type0))
2927 && null_ptr_cst_p (op1))
2928 result_type = type0;
2929 else if ((code1 == POINTER_TYPE || TYPE_PTRMEM_P (type1))
2930 && null_ptr_cst_p (op0))
2931 result_type = type1;
2932 else if (code0 == POINTER_TYPE && code1 == INTEGER_TYPE)
2934 result_type = type0;
2935 error ("ISO C++ forbids comparison between pointer and integer");
2937 else if (code0 == INTEGER_TYPE && code1 == POINTER_TYPE)
2939 result_type = type1;
2940 error ("ISO C++ forbids comparison between pointer and integer");
2942 else if (TYPE_PTRMEMFUNC_P (type0) && null_ptr_cst_p (op1))
2944 op0 = build_ptrmemfunc_access_expr (op0, pfn_identifier);
2945 op1 = cp_convert (TREE_TYPE (op0), integer_zero_node);
2946 result_type = TREE_TYPE (op0);
2948 else if (TYPE_PTRMEMFUNC_P (type1) && null_ptr_cst_p (op0))
2949 return cp_build_binary_op (code, op1, op0);
2950 else if (TYPE_PTRMEMFUNC_P (type0) && TYPE_PTRMEMFUNC_P (type1)
2951 && same_type_p (type0, type1))
2953 /* E will be the final comparison. */
2955 /* E1 and E2 are for scratch. */
2963 if (TREE_SIDE_EFFECTS (op0))
2964 op0 = save_expr (op0);
2965 if (TREE_SIDE_EFFECTS (op1))
2966 op1 = save_expr (op1);
2971 && (!op0.pfn || op0.delta == op1.delta))
2973 The reason for the `!op0.pfn' bit is that a NULL
2974 pointer-to-member is any member with a zero PFN; the
2975 DELTA field is unspecified. */
2976 pfn0 = pfn_from_ptrmemfunc (op0);
2977 pfn1 = pfn_from_ptrmemfunc (op1);
2978 delta0 = build_ptrmemfunc_access_expr (op0,
2980 delta1 = build_ptrmemfunc_access_expr (op1,
2982 e1 = cp_build_binary_op (EQ_EXPR, delta0, delta1);
2983 e2 = cp_build_binary_op (EQ_EXPR,
2985 cp_convert (TREE_TYPE (pfn0),
2986 integer_zero_node));
2987 e1 = cp_build_binary_op (TRUTH_ORIF_EXPR, e1, e2);
2988 e2 = build (EQ_EXPR, boolean_type_node, pfn0, pfn1);
2989 e = cp_build_binary_op (TRUTH_ANDIF_EXPR, e2, e1);
2990 if (code == EQ_EXPR)
2992 return cp_build_binary_op (EQ_EXPR, e, integer_zero_node);
2994 else if ((TYPE_PTRMEMFUNC_P (type0)
2995 && same_type_p (TYPE_PTRMEMFUNC_FN_TYPE (type0), type1))
2996 || (TYPE_PTRMEMFUNC_P (type1)
2997 && same_type_p (TYPE_PTRMEMFUNC_FN_TYPE (type1), type0)))
3003 if ((code0 == INTEGER_TYPE || code0 == REAL_TYPE)
3004 && (code1 == INTEGER_TYPE || code1 == REAL_TYPE))
3006 else if (code0 == POINTER_TYPE && code1 == POINTER_TYPE)
3007 result_type = composite_pointer_type (type0, type1, op0, op1,
3015 build_type = boolean_type_node;
3016 if ((code0 == INTEGER_TYPE || code0 == REAL_TYPE)
3017 && (code1 == INTEGER_TYPE || code1 == REAL_TYPE))
3019 else if (code0 == POINTER_TYPE && code1 == POINTER_TYPE)
3020 result_type = composite_pointer_type (type0, type1, op0, op1,
3022 else if (code0 == POINTER_TYPE && TREE_CODE (op1) == INTEGER_CST
3023 && integer_zerop (op1))
3024 result_type = type0;
3025 else if (code1 == POINTER_TYPE && TREE_CODE (op0) == INTEGER_CST
3026 && integer_zerop (op0))
3027 result_type = type1;
3028 else if (code0 == POINTER_TYPE && code1 == INTEGER_TYPE)
3030 result_type = type0;
3031 pedwarn ("ISO C++ forbids comparison between pointer and integer");
3033 else if (code0 == INTEGER_TYPE && code1 == POINTER_TYPE)
3035 result_type = type1;
3036 pedwarn ("ISO C++ forbids comparison between pointer and integer");
3040 case UNORDERED_EXPR:
3047 build_type = integer_type_node;
3048 if (code0 != REAL_TYPE || code1 != REAL_TYPE)
3050 error ("unordered comparison on non-floating point argument");
3051 return error_mark_node;
3060 if ((code0 == INTEGER_TYPE || code0 == REAL_TYPE || code0 == COMPLEX_TYPE)
3062 (code1 == INTEGER_TYPE || code1 == REAL_TYPE || code1 == COMPLEX_TYPE))
3064 int none_complex = (code0 != COMPLEX_TYPE && code1 != COMPLEX_TYPE);
3066 if (shorten || common || short_compare)
3067 result_type = common_type (type0, type1);
3069 /* For certain operations (which identify themselves by shorten != 0)
3070 if both args were extended from the same smaller type,
3071 do the arithmetic in that type and then extend.
3073 shorten !=0 and !=1 indicates a bitwise operation.
3074 For them, this optimization is safe only if
3075 both args are zero-extended or both are sign-extended.
3076 Otherwise, we might change the result.
3077 Eg, (short)-1 | (unsigned short)-1 is (int)-1
3078 but calculated in (unsigned short) it would be (unsigned short)-1. */
3080 if (shorten && none_complex)
3082 int unsigned0, unsigned1;
3083 tree arg0 = get_narrower (op0, &unsigned0);
3084 tree arg1 = get_narrower (op1, &unsigned1);
3085 /* UNS is 1 if the operation to be done is an unsigned one. */
3086 int uns = TREE_UNSIGNED (result_type);
3089 final_type = result_type;
3091 /* Handle the case that OP0 does not *contain* a conversion
3092 but it *requires* conversion to FINAL_TYPE. */
3094 if (op0 == arg0 && TREE_TYPE (op0) != final_type)
3095 unsigned0 = TREE_UNSIGNED (TREE_TYPE (op0));
3096 if (op1 == arg1 && TREE_TYPE (op1) != final_type)
3097 unsigned1 = TREE_UNSIGNED (TREE_TYPE (op1));
3099 /* Now UNSIGNED0 is 1 if ARG0 zero-extends to FINAL_TYPE. */
3101 /* For bitwise operations, signedness of nominal type
3102 does not matter. Consider only how operands were extended. */
3106 /* Note that in all three cases below we refrain from optimizing
3107 an unsigned operation on sign-extended args.
3108 That would not be valid. */
3110 /* Both args variable: if both extended in same way
3111 from same width, do it in that width.
3112 Do it unsigned if args were zero-extended. */
3113 if ((TYPE_PRECISION (TREE_TYPE (arg0))
3114 < TYPE_PRECISION (result_type))
3115 && (TYPE_PRECISION (TREE_TYPE (arg1))
3116 == TYPE_PRECISION (TREE_TYPE (arg0)))
3117 && unsigned0 == unsigned1
3118 && (unsigned0 || !uns))
3119 result_type = c_common_signed_or_unsigned_type
3120 (unsigned0, common_type (TREE_TYPE (arg0), TREE_TYPE (arg1)));
3121 else if (TREE_CODE (arg0) == INTEGER_CST
3122 && (unsigned1 || !uns)
3123 && (TYPE_PRECISION (TREE_TYPE (arg1))
3124 < TYPE_PRECISION (result_type))
3125 && (type = c_common_signed_or_unsigned_type
3126 (unsigned1, TREE_TYPE (arg1)),
3127 int_fits_type_p (arg0, type)))
3129 else if (TREE_CODE (arg1) == INTEGER_CST
3130 && (unsigned0 || !uns)
3131 && (TYPE_PRECISION (TREE_TYPE (arg0))
3132 < TYPE_PRECISION (result_type))
3133 && (type = c_common_signed_or_unsigned_type
3134 (unsigned0, TREE_TYPE (arg0)),
3135 int_fits_type_p (arg1, type)))
3139 /* Shifts can be shortened if shifting right. */
3144 tree arg0 = get_narrower (op0, &unsigned_arg);
3146 final_type = result_type;
3148 if (arg0 == op0 && final_type == TREE_TYPE (op0))
3149 unsigned_arg = TREE_UNSIGNED (TREE_TYPE (op0));
3151 if (TYPE_PRECISION (TREE_TYPE (arg0)) < TYPE_PRECISION (result_type)
3152 /* We can shorten only if the shift count is less than the
3153 number of bits in the smaller type size. */
3154 && compare_tree_int (op1, TYPE_PRECISION (TREE_TYPE (arg0))) < 0
3155 /* If arg is sign-extended and then unsigned-shifted,
3156 we can simulate this with a signed shift in arg's type
3157 only if the extended result is at least twice as wide
3158 as the arg. Otherwise, the shift could use up all the
3159 ones made by sign-extension and bring in zeros.
3160 We can't optimize that case at all, but in most machines
3161 it never happens because available widths are 2**N. */
3162 && (!TREE_UNSIGNED (final_type)
3164 || (((unsigned) 2 * TYPE_PRECISION (TREE_TYPE (arg0)))
3165 <= TYPE_PRECISION (result_type))))
3167 /* Do an unsigned shift if the operand was zero-extended. */
3169 = c_common_signed_or_unsigned_type (unsigned_arg,
3171 /* Convert value-to-be-shifted to that type. */
3172 if (TREE_TYPE (op0) != result_type)
3173 op0 = cp_convert (result_type, op0);
3178 /* Comparison operations are shortened too but differently.
3179 They identify themselves by setting short_compare = 1. */
3183 /* Don't write &op0, etc., because that would prevent op0
3184 from being kept in a register.
3185 Instead, make copies of the our local variables and
3186 pass the copies by reference, then copy them back afterward. */
3187 tree xop0 = op0, xop1 = op1, xresult_type = result_type;
3188 enum tree_code xresultcode = resultcode;
3190 = shorten_compare (&xop0, &xop1, &xresult_type, &xresultcode);
3192 return cp_convert (boolean_type_node, val);
3193 op0 = xop0, op1 = xop1;
3195 resultcode = xresultcode;
3198 if ((short_compare || code == MIN_EXPR || code == MAX_EXPR)
3199 && warn_sign_compare
3200 /* Do not warn until the template is instantiated; we cannot
3201 bound the ranges of the arguments until that point. */
3202 && !processing_template_decl)
3204 int op0_signed = ! TREE_UNSIGNED (TREE_TYPE (orig_op0));
3205 int op1_signed = ! TREE_UNSIGNED (TREE_TYPE (orig_op1));
3207 int unsignedp0, unsignedp1;
3208 tree primop0 = get_narrower (op0, &unsignedp0);
3209 tree primop1 = get_narrower (op1, &unsignedp1);
3211 /* Check for comparison of different enum types. */
3212 if (TREE_CODE (TREE_TYPE (orig_op0)) == ENUMERAL_TYPE
3213 && TREE_CODE (TREE_TYPE (orig_op1)) == ENUMERAL_TYPE
3214 && TYPE_MAIN_VARIANT (TREE_TYPE (orig_op0))
3215 != TYPE_MAIN_VARIANT (TREE_TYPE (orig_op1)))
3217 warning ("comparison between types `%#T' and `%#T'",
3218 TREE_TYPE (orig_op0), TREE_TYPE (orig_op1));
3221 /* Give warnings for comparisons between signed and unsigned
3222 quantities that may fail. */
3223 /* Do the checking based on the original operand trees, so that
3224 casts will be considered, but default promotions won't be. */
3226 /* Do not warn if the comparison is being done in a signed type,
3227 since the signed type will only be chosen if it can represent
3228 all the values of the unsigned type. */
3229 if (! TREE_UNSIGNED (result_type))
3231 /* Do not warn if both operands are unsigned. */
3232 else if (op0_signed == op1_signed)
3234 /* Do not warn if the signed quantity is an unsuffixed
3235 integer literal (or some static constant expression
3236 involving such literals or a conditional expression
3237 involving such literals) and it is non-negative. */
3238 else if ((op0_signed && tree_expr_nonnegative_p (orig_op0))
3239 || (op1_signed && tree_expr_nonnegative_p (orig_op1)))
3241 /* Do not warn if the comparison is an equality operation,
3242 the unsigned quantity is an integral constant and it does
3243 not use the most significant bit of result_type. */
3244 else if ((resultcode == EQ_EXPR || resultcode == NE_EXPR)
3245 && ((op0_signed && TREE_CODE (orig_op1) == INTEGER_CST
3246 && int_fits_type_p (orig_op1, c_common_signed_type
3248 || (op1_signed && TREE_CODE (orig_op0) == INTEGER_CST
3249 && int_fits_type_p (orig_op0, c_common_signed_type
3253 warning ("comparison between signed and unsigned integer expressions");
3255 /* Warn if two unsigned values are being compared in a size
3256 larger than their original size, and one (and only one) is the
3257 result of a `~' operator. This comparison will always fail.
3259 Also warn if one operand is a constant, and the constant does not
3260 have all bits set that are set in the ~ operand when it is
3263 if ((TREE_CODE (primop0) == BIT_NOT_EXPR)
3264 ^ (TREE_CODE (primop1) == BIT_NOT_EXPR))
3266 if (TREE_CODE (primop0) == BIT_NOT_EXPR)
3267 primop0 = get_narrower (TREE_OPERAND (op0, 0), &unsignedp0);
3268 if (TREE_CODE (primop1) == BIT_NOT_EXPR)
3269 primop1 = get_narrower (TREE_OPERAND (op1, 0), &unsignedp1);
3271 if (host_integerp (primop0, 0) || host_integerp (primop1, 0))
3274 HOST_WIDE_INT constant, mask;
3278 if (host_integerp (primop0, 0))
3281 unsignedp = unsignedp1;
3282 constant = tree_low_cst (primop0, 0);
3287 unsignedp = unsignedp0;
3288 constant = tree_low_cst (primop1, 0);
3291 bits = TYPE_PRECISION (TREE_TYPE (primop));
3292 if (bits < TYPE_PRECISION (result_type)
3293 && bits < HOST_BITS_PER_LONG && unsignedp)
3295 mask = (~ (HOST_WIDE_INT) 0) << bits;
3296 if ((mask & constant) != mask)
3297 warning ("comparison of promoted ~unsigned with constant");
3300 else if (unsignedp0 && unsignedp1
3301 && (TYPE_PRECISION (TREE_TYPE (primop0))
3302 < TYPE_PRECISION (result_type))
3303 && (TYPE_PRECISION (TREE_TYPE (primop1))
3304 < TYPE_PRECISION (result_type)))
3305 warning ("comparison of promoted ~unsigned with unsigned");
3310 /* At this point, RESULT_TYPE must be nonzero to avoid an error message.
3311 If CONVERTED is zero, both args will be converted to type RESULT_TYPE.
3312 Then the expression will be built.
3313 It will be given type FINAL_TYPE if that is nonzero;
3314 otherwise, it will be given type RESULT_TYPE. */
3318 error ("invalid operands of types `%T' and `%T' to binary `%O'",
3319 TREE_TYPE (orig_op0), TREE_TYPE (orig_op1), code);
3320 return error_mark_node;
3323 /* Issue warnings about peculiar, but valid, uses of NULL. */
3324 if (/* It's reasonable to use pointer values as operands of &&
3325 and ||, so NULL is no exception. */
3326 !(code == TRUTH_ANDIF_EXPR || code == TRUTH_ORIF_EXPR)
3327 && (/* If OP0 is NULL and OP1 is not a pointer, or vice versa. */
3328 (orig_op0 == null_node
3329 && TREE_CODE (TREE_TYPE (op1)) != POINTER_TYPE)
3330 /* Or vice versa. */
3331 || (orig_op1 == null_node
3332 && TREE_CODE (TREE_TYPE (op0)) != POINTER_TYPE)
3333 /* Or, both are NULL and the operation was not a comparison. */
3334 || (orig_op0 == null_node && orig_op1 == null_node
3335 && code != EQ_EXPR && code != NE_EXPR)))
3336 /* Some sort of arithmetic operation involving NULL was
3337 performed. Note that pointer-difference and pointer-addition
3338 have already been handled above, and so we don't end up here in
3340 warning ("NULL used in arithmetic");
3344 if (TREE_TYPE (op0) != result_type)
3345 op0 = cp_convert (result_type, op0);
3346 if (TREE_TYPE (op1) != result_type)
3347 op1 = cp_convert (result_type, op1);
3349 if (op0 == error_mark_node || op1 == error_mark_node)
3350 return error_mark_node;
3353 if (build_type == NULL_TREE)
3354 build_type = result_type;
3357 register tree result = build (resultcode, build_type, op0, op1);
3358 register tree folded;
3360 folded = fold (result);
3361 if (folded == result)
3362 TREE_CONSTANT (folded) = TREE_CONSTANT (op0) & TREE_CONSTANT (op1);
3363 if (final_type != 0)
3364 return cp_convert (final_type, folded);
3369 /* Return a tree for the sum or difference (RESULTCODE says which)
3370 of pointer PTROP and integer INTOP. */
3373 cp_pointer_int_sum (enum tree_code resultcode, register tree ptrop,
3374 register tree intop)
3376 tree res_type = TREE_TYPE (ptrop);
3378 /* pointer_int_sum() uses size_in_bytes() on the TREE_TYPE(res_type)
3379 in certain circumstance (when it's valid to do so). So we need
3380 to make sure it's complete. We don't need to check here, if we
3381 can actually complete it at all, as those checks will be done in
3382 pointer_int_sum() anyway. */
3383 complete_type (TREE_TYPE (res_type));
3385 return pointer_int_sum (resultcode, ptrop, fold (intop));
3388 /* Return a tree for the difference of pointers OP0 and OP1.
3389 The resulting tree has type int. */
3392 pointer_diff (register tree op0, register tree op1, register tree ptrtype)
3394 register tree result, folded;
3395 tree restype = ptrdiff_type_node;
3396 tree target_type = TREE_TYPE (ptrtype);
3398 if (!complete_type_or_else (target_type, NULL_TREE))
3399 return error_mark_node;
3401 if (pedantic || warn_pointer_arith)
3403 if (TREE_CODE (target_type) == VOID_TYPE)
3404 pedwarn ("ISO C++ forbids using pointer of type `void *' in subtraction");
3405 if (TREE_CODE (target_type) == FUNCTION_TYPE)
3406 pedwarn ("ISO C++ forbids using pointer to a function in subtraction");
3407 if (TREE_CODE (target_type) == METHOD_TYPE)
3408 pedwarn ("ISO C++ forbids using pointer to a method in subtraction");
3411 /* First do the subtraction as integers;
3412 then drop through to build the divide operator. */
3414 op0 = cp_build_binary_op (MINUS_EXPR,
3415 cp_convert (restype, op0),
3416 cp_convert (restype, op1));
3418 /* This generates an error if op1 is a pointer to an incomplete type. */
3419 if (!COMPLETE_TYPE_P (TREE_TYPE (TREE_TYPE (op1))))
3420 error ("invalid use of a pointer to an incomplete type in pointer arithmetic");
3422 op1 = (TYPE_PTROB_P (ptrtype)
3423 ? size_in_bytes (target_type)
3424 : integer_one_node);
3426 /* Do the division. */
3428 result = build (EXACT_DIV_EXPR, restype, op0, cp_convert (restype, op1));
3430 folded = fold (result);
3431 if (folded == result)
3432 TREE_CONSTANT (folded) = TREE_CONSTANT (op0) & TREE_CONSTANT (op1);
3436 /* Construct and perhaps optimize a tree representation
3437 for a unary operation. CODE, a tree_code, specifies the operation
3438 and XARG is the operand. */
3441 build_x_unary_op (enum tree_code code, tree xarg)
3443 tree orig_expr = xarg;
3447 if (processing_template_decl)
3449 if (type_dependent_expression_p (xarg))
3450 return build_min_nt (code, xarg, NULL_TREE);
3451 xarg = build_non_dependent_expr (xarg);
3456 /* & rec, on incomplete RECORD_TYPEs is the simple opr &, not an
3458 if (code == ADDR_EXPR
3459 && TREE_CODE (xarg) != TEMPLATE_ID_EXPR
3460 && ((IS_AGGR_TYPE_CODE (TREE_CODE (TREE_TYPE (xarg)))
3461 && !COMPLETE_TYPE_P (TREE_TYPE (xarg)))
3462 || (TREE_CODE (xarg) == OFFSET_REF)))
3463 /* don't look for a function */;
3465 exp = build_new_op (code, LOOKUP_NORMAL, xarg, NULL_TREE, NULL_TREE);
3466 if (!exp && code == ADDR_EXPR)
3468 /* A pointer to member-function can be formed only by saying
3470 if (!flag_ms_extensions && TREE_CODE (TREE_TYPE (xarg)) == METHOD_TYPE
3471 && (TREE_CODE (xarg) != OFFSET_REF || !PTRMEM_OK_P (xarg)))
3473 if (TREE_CODE (xarg) != OFFSET_REF)
3475 error ("invalid use of '%E' to form a pointer-to-member-function. Use a qualified-id.",
3477 return error_mark_node;
3481 error ("parenthesis around '%E' cannot be used to form a pointer-to-member-function",
3483 PTRMEM_OK_P (xarg) = 1;
3487 if (TREE_CODE (xarg) == OFFSET_REF)
3489 ptrmem = PTRMEM_OK_P (xarg);
3491 if (!ptrmem && !flag_ms_extensions
3492 && TREE_CODE (TREE_TYPE (TREE_OPERAND (xarg, 1))) == METHOD_TYPE)
3494 /* A single non-static member, make sure we don't allow a
3495 pointer-to-member. */
3496 xarg = build (OFFSET_REF, TREE_TYPE (xarg),
3497 TREE_OPERAND (xarg, 0),
3498 ovl_cons (TREE_OPERAND (xarg, 1), NULL_TREE));
3499 PTRMEM_OK_P (xarg) = ptrmem;
3502 else if (TREE_CODE (xarg) == TARGET_EXPR)
3503 warning ("taking address of temporary");
3504 exp = build_unary_op (ADDR_EXPR, xarg, 0);
3505 if (TREE_CODE (exp) == ADDR_EXPR)
3506 PTRMEM_OK_P (exp) = ptrmem;
3509 if (processing_template_decl && exp != error_mark_node)
3510 return build_min (code, TREE_TYPE (exp), orig_expr, NULL_TREE);
3514 /* Like c_common_truthvalue_conversion, but handle pointer-to-member
3515 constants, where a null value is represented by an INTEGER_CST of
3519 cp_truthvalue_conversion (tree expr)
3521 tree type = TREE_TYPE (expr);
3522 if (TYPE_PTRMEM_P (type))
3523 return build_binary_op (NE_EXPR, expr, integer_zero_node, 1);
3525 return c_common_truthvalue_conversion (expr);
3528 /* Just like cp_truthvalue_conversion, but we want a CLEANUP_POINT_EXPR. */
3531 condition_conversion (tree expr)
3534 if (processing_template_decl)
3536 t = perform_implicit_conversion (boolean_type_node, expr);
3537 t = fold (build1 (CLEANUP_POINT_EXPR, boolean_type_node, t));
3541 /* Return an ADDR_EXPR giving the address of T. This function
3542 attempts no optimizations or simplifications; it is a low-level
3546 build_address (tree t)
3550 if (error_operand_p (t) || !cxx_mark_addressable (t))
3551 return error_mark_node;
3553 addr = build1 (ADDR_EXPR,
3554 build_pointer_type (TREE_TYPE (t)),
3557 TREE_CONSTANT (addr) = 1;
3562 /* Return a NOP_EXPR converting EXPR to TYPE. */
3565 build_nop (tree type, tree expr)
3569 if (type == error_mark_node || error_operand_p (expr))
3572 nop = build1 (NOP_EXPR, type, expr);
3573 if (TREE_CONSTANT (expr))
3574 TREE_CONSTANT (nop) = 1;
3579 /* C++: Must handle pointers to members.
3581 Perhaps type instantiation should be extended to handle conversion
3582 from aggregates to types we don't yet know we want? (Or are those
3583 cases typically errors which should be reported?)
3585 NOCONVERT nonzero suppresses the default promotions
3586 (such as from short to int). */
3589 build_unary_op (enum tree_code code, tree xarg, int noconvert)
3591 /* No default_conversion here. It causes trouble for ADDR_EXPR. */
3592 register tree arg = xarg;
3593 register tree argtype = 0;
3594 const char *errstring = NULL;
3597 if (arg == error_mark_node)
3598 return error_mark_node;
3603 /* This is used for unary plus, because a CONVERT_EXPR
3604 is enough to prevent anybody from looking inside for
3605 associativity, but won't generate any code. */
3606 if (!(arg = build_expr_type_conversion
3607 (WANT_ARITH | WANT_ENUM | WANT_POINTER, arg, true)))
3608 errstring = "wrong type argument to unary plus";
3612 arg = default_conversion (arg);
3613 arg = build1 (NON_LVALUE_EXPR, TREE_TYPE (arg), arg);
3614 TREE_CONSTANT (arg) = TREE_CONSTANT (TREE_OPERAND (arg, 0));
3619 if (!(arg = build_expr_type_conversion (WANT_ARITH | WANT_ENUM, arg, true)))
3620 errstring = "wrong type argument to unary minus";
3621 else if (!noconvert && CP_INTEGRAL_TYPE_P (TREE_TYPE (arg)))
3622 arg = perform_integral_promotions (arg);
3626 if (TREE_CODE (TREE_TYPE (arg)) == COMPLEX_TYPE)
3630 arg = default_conversion (arg);
3632 else if (!(arg = build_expr_type_conversion (WANT_INT | WANT_ENUM,
3634 errstring = "wrong type argument to bit-complement";
3635 else if (!noconvert)
3636 arg = perform_integral_promotions (arg);
3640 if (!(arg = build_expr_type_conversion (WANT_ARITH | WANT_ENUM, arg, true)))
3641 errstring = "wrong type argument to abs";
3642 else if (!noconvert)
3643 arg = default_conversion (arg);
3647 /* Conjugating a real value is a no-op, but allow it anyway. */
3648 if (!(arg = build_expr_type_conversion (WANT_ARITH | WANT_ENUM, arg, true)))
3649 errstring = "wrong type argument to conjugation";
3650 else if (!noconvert)
3651 arg = default_conversion (arg);
3654 case TRUTH_NOT_EXPR:
3655 arg = perform_implicit_conversion (boolean_type_node, arg);
3656 val = invert_truthvalue (arg);
3657 if (arg != error_mark_node)
3659 errstring = "in argument to unary !";
3666 if (TREE_CODE (arg) == COMPLEX_CST)
3667 return TREE_REALPART (arg);
3668 else if (TREE_CODE (TREE_TYPE (arg)) == COMPLEX_TYPE)
3669 return fold (build1 (REALPART_EXPR, TREE_TYPE (TREE_TYPE (arg)), arg));
3674 if (TREE_CODE (arg) == COMPLEX_CST)
3675 return TREE_IMAGPART (arg);
3676 else if (TREE_CODE (TREE_TYPE (arg)) == COMPLEX_TYPE)
3677 return fold (build1 (IMAGPART_EXPR, TREE_TYPE (TREE_TYPE (arg)), arg));
3679 return cp_convert (TREE_TYPE (arg), integer_zero_node);
3681 case PREINCREMENT_EXPR:
3682 case POSTINCREMENT_EXPR:
3683 case PREDECREMENT_EXPR:
3684 case POSTDECREMENT_EXPR:
3685 /* Handle complex lvalues (when permitted)
3686 by reduction to simpler cases. */
3688 val = unary_complex_lvalue (code, arg);
3692 /* Increment or decrement the real part of the value,
3693 and don't change the imaginary part. */
3694 if (TREE_CODE (TREE_TYPE (arg)) == COMPLEX_TYPE)
3698 arg = stabilize_reference (arg);
3699 real = build_unary_op (REALPART_EXPR, arg, 1);
3700 imag = build_unary_op (IMAGPART_EXPR, arg, 1);
3701 return build (COMPLEX_EXPR, TREE_TYPE (arg),
3702 build_unary_op (code, real, 1), imag);
3705 /* Report invalid types. */
3707 if (!(arg = build_expr_type_conversion (WANT_ARITH | WANT_POINTER,
3710 if (code == PREINCREMENT_EXPR)
3711 errstring ="no pre-increment operator for type";
3712 else if (code == POSTINCREMENT_EXPR)
3713 errstring ="no post-increment operator for type";
3714 else if (code == PREDECREMENT_EXPR)
3715 errstring ="no pre-decrement operator for type";
3717 errstring ="no post-decrement operator for type";
3721 /* Report something read-only. */
3723 if (CP_TYPE_CONST_P (TREE_TYPE (arg))
3724 || TREE_READONLY (arg))
3725 readonly_error (arg, ((code == PREINCREMENT_EXPR
3726 || code == POSTINCREMENT_EXPR)
3727 ? "increment" : "decrement"),
3732 tree result_type = TREE_TYPE (arg);
3734 arg = get_unwidened (arg, 0);
3735 argtype = TREE_TYPE (arg);
3737 /* ARM $5.2.5 last annotation says this should be forbidden. */
3738 if (TREE_CODE (argtype) == ENUMERAL_TYPE)
3739 pedwarn ("ISO C++ forbids %sing an enum",
3740 (code == PREINCREMENT_EXPR || code == POSTINCREMENT_EXPR)
3741 ? "increment" : "decrement");
3743 /* Compute the increment. */
3745 if (TREE_CODE (argtype) == POINTER_TYPE)
3747 tree type = complete_type (TREE_TYPE (argtype));
3749 if (!COMPLETE_OR_VOID_TYPE_P (type))
3750 error ("cannot %s a pointer to incomplete type `%T'",
3751 ((code == PREINCREMENT_EXPR
3752 || code == POSTINCREMENT_EXPR)
3753 ? "increment" : "decrement"), TREE_TYPE (argtype));
3754 else if ((pedantic || warn_pointer_arith)
3755 && !TYPE_PTROB_P (argtype))
3756 pedwarn ("ISO C++ forbids %sing a pointer of type `%T'",
3757 ((code == PREINCREMENT_EXPR
3758 || code == POSTINCREMENT_EXPR)
3759 ? "increment" : "decrement"), argtype);
3760 inc = cxx_sizeof_nowarn (TREE_TYPE (argtype));
3763 inc = integer_one_node;
3765 inc = cp_convert (argtype, inc);
3767 /* Handle incrementing a cast-expression. */
3769 switch (TREE_CODE (arg))
3774 case FIX_TRUNC_EXPR:
3775 case FIX_FLOOR_EXPR:
3776 case FIX_ROUND_EXPR:
3779 tree incremented, modify, value, compound;
3780 if (! lvalue_p (arg) && pedantic)
3781 pedwarn ("cast to non-reference type used as lvalue");
3782 arg = stabilize_reference (arg);
3783 if (code == PREINCREMENT_EXPR || code == PREDECREMENT_EXPR)
3786 value = save_expr (arg);
3787 incremented = build (((code == PREINCREMENT_EXPR
3788 || code == POSTINCREMENT_EXPR)
3789 ? PLUS_EXPR : MINUS_EXPR),
3790 argtype, value, inc);
3792 modify = build_modify_expr (arg, NOP_EXPR, incremented);
3793 compound = build (COMPOUND_EXPR, TREE_TYPE (arg), modify, value);
3795 /* Eliminate warning about unused result of + or -. */
3796 TREE_NO_UNUSED_WARNING (compound) = 1;
3804 /* Complain about anything else that is not a true lvalue. */
3805 if (!lvalue_or_else (arg, ((code == PREINCREMENT_EXPR
3806 || code == POSTINCREMENT_EXPR)
3807 ? "increment" : "decrement")))
3808 return error_mark_node;
3810 /* Forbid using -- on `bool'. */
3811 if (TREE_TYPE (arg) == boolean_type_node)
3813 if (code == POSTDECREMENT_EXPR || code == PREDECREMENT_EXPR)
3815 error ("invalid use of `--' on bool variable `%D'", arg);
3816 return error_mark_node;
3818 val = boolean_increment (code, arg);
3821 val = build (code, TREE_TYPE (arg), arg, inc);
3823 TREE_SIDE_EFFECTS (val) = 1;
3824 return cp_convert (result_type, val);
3828 /* Note that this operation never does default_conversion
3829 regardless of NOCONVERT. */
3831 argtype = lvalue_type (arg);
3833 if (TREE_CODE (arg) == OFFSET_REF)
3836 if (TREE_CODE (argtype) == REFERENCE_TYPE)
3840 build_pointer_type (TREE_TYPE (argtype)), arg);
3841 TREE_CONSTANT (arg) = TREE_CONSTANT (TREE_OPERAND (arg, 0));
3844 else if (pedantic && DECL_MAIN_P (arg))
3846 pedwarn ("ISO C++ forbids taking address of function `::main'");
3848 /* Let &* cancel out to simplify resulting code. */
3849 if (TREE_CODE (arg) == INDIRECT_REF)
3851 /* We don't need to have `current_class_ptr' wrapped in a
3852 NON_LVALUE_EXPR node. */
3853 if (arg == current_class_ref)
3854 return current_class_ptr;
3856 arg = TREE_OPERAND (arg, 0);
3857 if (TREE_CODE (TREE_TYPE (arg)) == REFERENCE_TYPE)
3861 build_pointer_type (TREE_TYPE (TREE_TYPE (arg))), arg);
3862 TREE_CONSTANT (arg) = TREE_CONSTANT (TREE_OPERAND (arg, 0));
3864 else if (lvalue_p (arg))
3865 /* Don't let this be an lvalue. */
3866 return non_lvalue (arg);
3870 /* For &x[y], return x+y */
3871 if (TREE_CODE (arg) == ARRAY_REF)
3873 if (!cxx_mark_addressable (TREE_OPERAND (arg, 0)))
3874 return error_mark_node;
3875 return cp_build_binary_op (PLUS_EXPR, TREE_OPERAND (arg, 0),
3876 TREE_OPERAND (arg, 1));
3879 /* Uninstantiated types are all functions. Taking the
3880 address of a function is a no-op, so just return the
3883 if (TREE_CODE (arg) == IDENTIFIER_NODE
3884 && IDENTIFIER_OPNAME_P (arg))
3887 /* We don't know the type yet, so just work around the problem.
3888 We know that this will resolve to an lvalue. */
3889 return build1 (ADDR_EXPR, unknown_type_node, arg);
3892 if (TREE_CODE (arg) == COMPONENT_REF && type_unknown_p (arg)
3893 && !really_overloaded_fn (TREE_OPERAND (arg, 1)))
3895 /* They're trying to take the address of a unique non-static
3896 member function. This is ill-formed (except in MS-land),
3897 but let's try to DTRT.
3898 Note: We only handle unique functions here because we don't
3899 want to complain if there's a static overload; non-unique
3900 cases will be handled by instantiate_type. But we need to
3901 handle this case here to allow casts on the resulting PMF.
3902 We could defer this in non-MS mode, but it's easier to give
3903 a useful error here. */
3905 /* Inside constant member functions, the `this' pointer
3906 contains an extra const qualifier. TYPE_MAIN_VARIANT
3907 is used here to remove this const from the diagnostics
3908 and the created OFFSET_REF. */
3909 tree base = TYPE_MAIN_VARIANT (TREE_TYPE (TREE_OPERAND (arg, 0)));
3910 tree name = DECL_NAME (get_first_fn (TREE_OPERAND (arg, 1)));
3912 if (! flag_ms_extensions)
3914 if (current_class_type
3915 && TREE_OPERAND (arg, 0) == current_class_ref)
3916 /* An expression like &memfn. */
3917 pedwarn ("ISO C++ forbids taking the address of an unqualified"
3918 " or parenthesized non-static member function to form"
3919 " a pointer to member function. Say `&%T::%D'",
3922 pedwarn ("ISO C++ forbids taking the address of a bound member"
3923 " function to form a pointer to member function."
3927 arg = build_offset_ref (base, name, /*address_p=*/true);
3931 if (type_unknown_p (arg))
3932 return build1 (ADDR_EXPR, unknown_type_node, arg);
3934 /* Handle complex lvalues (when permitted)
3935 by reduction to simpler cases. */
3936 val = unary_complex_lvalue (code, arg);
3940 switch (TREE_CODE (arg))
3945 case FIX_TRUNC_EXPR:
3946 case FIX_FLOOR_EXPR:
3947 case FIX_ROUND_EXPR:
3949 if (! lvalue_p (arg) && pedantic)
3950 pedwarn ("ISO C++ forbids taking the address of a cast to a non-lvalue expression");
3957 /* Allow the address of a constructor if all the elements
3959 if (TREE_CODE (arg) == CONSTRUCTOR && TREE_HAS_CONSTRUCTOR (arg)
3960 && TREE_CONSTANT (arg))
3962 /* Anything not already handled and not a true memory reference
3964 else if (TREE_CODE (argtype) != FUNCTION_TYPE
3965 && TREE_CODE (argtype) != METHOD_TYPE
3966 && !non_cast_lvalue_or_else (arg, "unary `&'"))
3967 return error_mark_node;
3969 if (argtype != error_mark_node)
3970 argtype = build_pointer_type (argtype);
3975 if (TREE_CODE (arg) == COMPONENT_REF
3976 && TREE_CODE (TREE_OPERAND (arg, 1)) == BASELINK)
3977 arg = BASELINK_FUNCTIONS (TREE_OPERAND (arg, 1));
3979 if (TREE_CODE (arg) != COMPONENT_REF)
3980 addr = build_address (arg);
3981 else if (DECL_C_BIT_FIELD (TREE_OPERAND (arg, 1)))
3983 error ("attempt to take address of bit-field structure member `%D'",
3984 TREE_OPERAND (arg, 1));
3985 return error_mark_node;
3989 /* Unfortunately we cannot just build an address
3990 expression here, because we would not handle
3991 address-constant-expressions or offsetof correctly. */
3992 tree field = TREE_OPERAND (arg, 1);
3993 tree rval = build_unary_op (ADDR_EXPR, TREE_OPERAND (arg, 0), 0);
3994 tree binfo = lookup_base (TREE_TYPE (TREE_TYPE (rval)),
3995 decl_type_context (field),
3998 rval = build_base_path (PLUS_EXPR, rval, binfo, 1);
3999 rval = build_nop (argtype, rval);
4000 addr = fold (build (PLUS_EXPR, argtype, rval,
4001 cp_convert (argtype, byte_position (field))));
4004 if (TREE_CODE (argtype) == POINTER_TYPE
4005 && TREE_CODE (TREE_TYPE (argtype)) == METHOD_TYPE)
4007 build_ptrmemfunc_type (argtype);
4008 addr = build_ptrmemfunc (argtype, addr, 0);
4021 argtype = TREE_TYPE (arg);
4022 return fold (build1 (code, argtype, arg));
4025 error ("%s", errstring);
4026 return error_mark_node;
4029 /* Apply unary lvalue-demanding operator CODE to the expression ARG
4030 for certain kinds of expressions which are not really lvalues
4031 but which we can accept as lvalues.
4033 If ARG is not a kind of expression we can handle, return zero. */
4036 unary_complex_lvalue (enum tree_code code, tree arg)
4038 /* Handle (a, b) used as an "lvalue". */
4039 if (TREE_CODE (arg) == COMPOUND_EXPR)
4041 tree real_result = build_unary_op (code, TREE_OPERAND (arg, 1), 0);
4042 return build (COMPOUND_EXPR, TREE_TYPE (real_result),
4043 TREE_OPERAND (arg, 0), real_result);
4046 /* Handle (a ? b : c) used as an "lvalue". */
4047 if (TREE_CODE (arg) == COND_EXPR
4048 || TREE_CODE (arg) == MIN_EXPR || TREE_CODE (arg) == MAX_EXPR)
4049 return rationalize_conditional_expr (code, arg);
4051 /* Handle (a = b), (++a), and (--a) used as an "lvalue". */
4052 if (TREE_CODE (arg) == MODIFY_EXPR
4053 || TREE_CODE (arg) == PREINCREMENT_EXPR
4054 || TREE_CODE (arg) == PREDECREMENT_EXPR)
4056 tree lvalue = TREE_OPERAND (arg, 0);
4057 if (TREE_SIDE_EFFECTS (lvalue))
4059 lvalue = stabilize_reference (lvalue);
4060 arg = build (TREE_CODE (arg), TREE_TYPE (arg),
4061 lvalue, TREE_OPERAND (arg, 1));
4063 return unary_complex_lvalue
4064 (code, build (COMPOUND_EXPR, TREE_TYPE (lvalue), arg, lvalue));
4067 if (code != ADDR_EXPR)
4070 /* Handle (a = b) used as an "lvalue" for `&'. */
4071 if (TREE_CODE (arg) == MODIFY_EXPR
4072 || TREE_CODE (arg) == INIT_EXPR)
4074 tree real_result = build_unary_op (code, TREE_OPERAND (arg, 0), 0);
4075 arg = build (COMPOUND_EXPR, TREE_TYPE (real_result), arg, real_result);
4076 TREE_NO_UNUSED_WARNING (arg) = 1;
4080 if (TREE_CODE (TREE_TYPE (arg)) == FUNCTION_TYPE
4081 || TREE_CODE (TREE_TYPE (arg)) == METHOD_TYPE
4082 || TREE_CODE (arg) == OFFSET_REF)
4086 my_friendly_assert (TREE_CODE (arg) != SCOPE_REF, 313);
4088 if (TREE_CODE (arg) != OFFSET_REF)
4091 t = TREE_OPERAND (arg, 1);
4093 /* Check all this code for right semantics. */
4094 if (TREE_CODE (t) == FUNCTION_DECL)
4096 if (DECL_DESTRUCTOR_P (t))
4097 error ("taking address of destructor");
4098 return build_unary_op (ADDR_EXPR, t, 0);
4100 if (TREE_CODE (t) == VAR_DECL)
4101 return build_unary_op (ADDR_EXPR, t, 0);
4106 if (TREE_OPERAND (arg, 0)
4107 && ! is_dummy_object (TREE_OPERAND (arg, 0))
4108 && TREE_CODE (t) != FIELD_DECL)
4110 error ("taking address of bound pointer-to-member expression");
4111 return error_mark_node;
4113 if (!PTRMEM_OK_P (arg))
4114 return build_unary_op (code, arg, 0);
4116 if (TREE_CODE (TREE_TYPE (t)) == REFERENCE_TYPE)
4118 error ("cannot create pointer to reference member `%D'", t);
4119 return error_mark_node;
4122 type = build_ptrmem_type (DECL_FIELD_CONTEXT (t), TREE_TYPE (t));
4123 t = make_ptrmem_cst (type, TREE_OPERAND (arg, 1));
4129 /* We permit compiler to make function calls returning
4130 objects of aggregate type look like lvalues. */
4134 if (TREE_CODE (targ) == SAVE_EXPR)
4135 targ = TREE_OPERAND (targ, 0);
4137 if (TREE_CODE (targ) == CALL_EXPR && IS_AGGR_TYPE (TREE_TYPE (targ)))
4139 if (TREE_CODE (arg) == SAVE_EXPR)
4142 targ = build_cplus_new (TREE_TYPE (arg), arg);
4143 return build1 (ADDR_EXPR, build_pointer_type (TREE_TYPE (arg)), targ);
4146 if (TREE_CODE (arg) == SAVE_EXPR && TREE_CODE (targ) == INDIRECT_REF)
4147 return build (SAVE_EXPR, build_pointer_type (TREE_TYPE (arg)),
4148 TREE_OPERAND (targ, 0), current_function_decl, NULL);
4151 /* Don't let anything else be handled specially. */
4155 /* Mark EXP saying that we need to be able to take the
4156 address of it; it should not be allocated in a register.
4157 Value is true if successful.
4159 C++: we do not allow `current_class_ptr' to be addressable. */
4162 cxx_mark_addressable (tree exp)
4164 register tree x = exp;
4167 switch (TREE_CODE (x))
4174 x = TREE_OPERAND (x, 0);
4178 if (x == current_class_ptr)
4180 error ("cannot take the address of `this', which is an rvalue expression");
4181 TREE_ADDRESSABLE (x) = 1; /* so compiler doesn't die later */
4187 /* Caller should not be trying to mark initialized
4188 constant fields addressable. */
4189 my_friendly_assert (DECL_LANG_SPECIFIC (x) == 0
4190 || DECL_IN_AGGR_P (x) == 0
4192 || DECL_EXTERNAL (x), 314);
4197 if (DECL_REGISTER (x) && !TREE_ADDRESSABLE (x)
4198 && !DECL_ARTIFICIAL (x) && extra_warnings)
4199 warning ("address requested for `%D', which is declared `register'",
4201 TREE_ADDRESSABLE (x) = 1;
4202 put_var_into_stack (x, /*rescan=*/true);
4206 TREE_ADDRESSABLE (x) = 1;
4207 TREE_ADDRESSABLE (DECL_ASSEMBLER_NAME (x)) = 1;
4211 TREE_ADDRESSABLE (x) = 1;
4215 TREE_ADDRESSABLE (x) = 1;
4216 cxx_mark_addressable (TREE_OPERAND (x, 0));
4224 /* Build and return a conditional expression IFEXP ? OP1 : OP2. */
4227 build_x_conditional_expr (tree ifexp, tree op1, tree op2)
4229 tree orig_ifexp = ifexp;
4230 tree orig_op1 = op1;
4231 tree orig_op2 = op2;
4234 if (processing_template_decl)
4236 /* The standard says that the expression is type-dependent if
4237 IFEXP is type-dependent, even though the eventual type of the
4238 expression doesn't dependent on IFEXP. */
4239 if (type_dependent_expression_p (ifexp)
4240 || type_dependent_expression_p (op1)
4241 || type_dependent_expression_p (op2))
4242 return build_min_nt (COND_EXPR, ifexp, op1, op2);
4243 ifexp = build_non_dependent_expr (ifexp);
4244 op1 = build_non_dependent_expr (op1);
4245 op2 = build_non_dependent_expr (op2);
4248 expr = build_conditional_expr (ifexp, op1, op2);
4249 if (processing_template_decl && expr != error_mark_node)
4250 return build_min (COND_EXPR, TREE_TYPE (expr),
4251 orig_ifexp, orig_op1, orig_op2);
4255 /* Given a list of expressions, return a compound expression
4256 that performs them all and returns the value of the last of them. */
4258 tree build_x_compound_expr_from_list (tree list, const char *msg)
4260 tree expr = TREE_VALUE (list);
4262 if (TREE_CHAIN (list))
4265 pedwarn ("%s expression list treated as compound expression", msg);
4267 for (list = TREE_CHAIN (list); list; list = TREE_CHAIN (list))
4268 expr = build_x_compound_expr (expr, TREE_VALUE (list));
4274 /* Handle overloading of the ',' operator when needed. */
4277 build_x_compound_expr (tree op1, tree op2)
4280 tree orig_op1 = op1;
4281 tree orig_op2 = op2;
4283 if (processing_template_decl)
4285 if (type_dependent_expression_p (op1)
4286 || type_dependent_expression_p (op2))
4287 return build_min_nt (COMPOUND_EXPR, op1, op2);
4288 op1 = build_non_dependent_expr (op1);
4289 op2 = build_non_dependent_expr (op2);
4292 result = build_new_op (COMPOUND_EXPR, LOOKUP_NORMAL, op1, op2, NULL_TREE);
4295 if (! TREE_SIDE_EFFECTS (op1))
4297 /* FIXME: This test should be in the implicit cast to void
4299 /* the left-hand operand of a comma expression is like an expression
4300 statement: we should warn if it doesn't have any side-effects,
4301 unless it was explicitly cast to (void). */
4302 if (warn_unused_value
4303 && !(TREE_CODE (op1) == CONVERT_EXPR
4304 && VOID_TYPE_P (TREE_TYPE (op1))))
4305 warning("left-hand operand of comma expression has no effect");
4307 result = build_compound_expr (op1, op2);
4310 if (processing_template_decl && result != error_mark_node)
4311 return build_min (COMPOUND_EXPR, TREE_TYPE (result),
4312 orig_op1, orig_op2);
4316 /* Build a compound expression. */
4319 build_compound_expr (tree lhs, tree rhs)
4321 lhs = decl_constant_value (lhs);
4322 lhs = convert_to_void (lhs, "left-hand operand of comma");
4323 if (lhs == error_mark_node || rhs == error_mark_node)
4324 return error_mark_node;
4326 if (TREE_CODE (rhs) == TARGET_EXPR)
4328 /* If the rhs is a TARGET_EXPR, then build the compound
4329 expression inside the target_expr's initializer. This
4330 helps the compiler to eliminate unncessary temporaries. */
4331 tree init = TREE_OPERAND (rhs, 1);
4333 init = build (COMPOUND_EXPR, TREE_TYPE (init), lhs, init);
4334 TREE_OPERAND (rhs, 1) = init;
4339 return build (COMPOUND_EXPR, TREE_TYPE (rhs), lhs, rhs);
4342 /* Issue an error message if casting from SRC_TYPE to DEST_TYPE casts
4343 away constness. DESCRIPTION explains what operation is taking
4347 check_for_casting_away_constness (tree src_type, tree dest_type,
4348 const char *description)
4350 if (casts_away_constness (src_type, dest_type))
4351 error ("%s from type `%T' to type `%T' casts away constness",
4352 description, src_type, dest_type);
4355 /* Return an expression representing static_cast<TYPE>(EXPR). */
4358 build_static_cast (tree type, tree expr)
4363 if (type == error_mark_node || expr == error_mark_node)
4364 return error_mark_node;
4366 if (processing_template_decl)
4368 tree t = build_min (STATIC_CAST_EXPR, type, expr);
4372 /* build_c_cast puts on a NOP_EXPR to make the result not an lvalue.
4373 Strip such NOP_EXPRs if VALUE is being used in non-lvalue context. */
4374 if (TREE_CODE (type) != REFERENCE_TYPE
4375 && TREE_CODE (expr) == NOP_EXPR
4376 && TREE_TYPE (expr) == TREE_TYPE (TREE_OPERAND (expr, 0)))
4377 expr = TREE_OPERAND (expr, 0);
4379 intype = TREE_TYPE (expr);
4381 /* [expr.static.cast]
4383 An lvalue of type "cv1 B", where B is a class type, can be cast
4384 to type "reference to cv2 D", where D is a class derived (clause
4385 _class.derived_) from B, if a valid standard conversion from
4386 "pointer to D" to "pointer to B" exists (_conv.ptr_), cv2 is the
4387 same cv-qualification as, or greater cv-qualification than, cv1,
4388 and B is not a virtual base class of D. */
4389 /* We check this case before checking the validity of "TYPE t =
4390 EXPR;" below because for this case:
4393 struct D : public B { D(const B&); };
4395 void f() { static_cast<const D&>(b); }
4397 we want to avoid constructing a new D. The standard is not
4398 completely clear about this issue, but our interpretation is
4399 consistent with other compilers. */
4400 if (TREE_CODE (type) == REFERENCE_TYPE
4401 && CLASS_TYPE_P (TREE_TYPE (type))
4402 && CLASS_TYPE_P (intype)
4403 && real_non_cast_lvalue_p (expr)
4404 && DERIVED_FROM_P (intype, TREE_TYPE (type))
4405 && can_convert (build_pointer_type (TYPE_MAIN_VARIANT (intype)),
4406 build_pointer_type (TYPE_MAIN_VARIANT
4407 (TREE_TYPE (type))))
4408 && at_least_as_qualified_p (TREE_TYPE (type), intype))
4410 /* At this point we have checked all of the conditions except
4411 that B is not a virtual base class of D. That will be
4412 checked by build_base_path. */
4413 tree base = lookup_base (TREE_TYPE (type), intype, ba_any, NULL);
4415 /* Convert from B* to D*. */
4416 expr = build_base_path (MINUS_EXPR, build_address (expr),
4417 base, /*nonnull=*/false);
4418 /* Convert the pointer to a reference -- but then remember that
4419 there are no expressions with reference type in C++. */
4420 return convert_from_reference (build_nop (type, expr));
4423 /* [expr.static.cast]
4425 An expression e can be explicitly converted to a type T using a
4426 static_cast of the form static_cast<T>(e) if the declaration T
4427 t(e);" is well-formed, for some invented temporary variable
4429 result = perform_direct_initialization_if_possible (type, expr);
4431 return convert_from_reference (result);
4433 /* [expr.static.cast]
4435 Any expression can be explicitly converted to type cv void. */
4436 if (TREE_CODE (type) == VOID_TYPE)
4437 return convert_to_void (expr, /*implicit=*/NULL);
4439 /* [expr.static.cast]
4441 The inverse of any standard conversion sequence (clause _conv_),
4442 other than the lvalue-to-rvalue (_conv.lval_), array-to-pointer
4443 (_conv.array_), function-to-pointer (_conv.func_), and boolean
4444 (_conv.bool_) conversions, can be performed explicitly using
4445 static_cast subject to the restriction that the explicit
4446 conversion does not cast away constness (_expr.const.cast_), and
4447 the following additional rules for specific cases: */
4448 /* For reference, the conversions not excluded are: integral
4449 promotions, floating point promotion, integral conversions,
4450 floating point conversions, floating-integral conversions,
4451 pointer conversions, and pointer to member conversions. */
4452 if ((ARITHMETIC_TYPE_P (type) && ARITHMETIC_TYPE_P (intype))
4455 A value of integral _or enumeration_ type can be explicitly
4456 converted to an enumeration type. */
4457 || (INTEGRAL_OR_ENUMERATION_TYPE_P (type)
4458 && INTEGRAL_OR_ENUMERATION_TYPE_P (intype)))
4459 /* Really, build_c_cast should defer to this function rather
4460 than the other way around. */
4461 return build_c_cast (type, expr);
4462 if (TYPE_PTR_P (type) && TYPE_PTR_P (intype)
4463 && CLASS_TYPE_P (TREE_TYPE (type))
4464 && CLASS_TYPE_P (TREE_TYPE (intype))
4465 && can_convert (build_pointer_type (TYPE_MAIN_VARIANT
4466 (TREE_TYPE (intype))),
4467 build_pointer_type (TYPE_MAIN_VARIANT
4468 (TREE_TYPE (type)))))
4472 check_for_casting_away_constness (intype, type, "static_cast");
4473 base = lookup_base (TREE_TYPE (type), TREE_TYPE (intype),
4474 ba_check | ba_quiet, NULL);
4475 return build_base_path (MINUS_EXPR, expr, base, /*nonnull=*/false);
4477 if ((TYPE_PTRMEM_P (type) && TYPE_PTRMEM_P (intype))
4478 || (TYPE_PTRMEMFUNC_P (type) && TYPE_PTRMEMFUNC_P (intype)))
4485 c1 = TYPE_PTRMEM_CLASS_TYPE (intype);
4486 c2 = TYPE_PTRMEM_CLASS_TYPE (type);
4488 if (TYPE_PTRMEM_P (type))
4490 t1 = (build_ptrmem_type
4492 TYPE_MAIN_VARIANT (TYPE_PTRMEM_POINTED_TO_TYPE (intype))));
4493 t2 = (build_ptrmem_type
4495 TYPE_MAIN_VARIANT (TYPE_PTRMEM_POINTED_TO_TYPE (type))));
4502 if (can_convert (t1, t2))
4504 check_for_casting_away_constness (intype, type, "static_cast");
4505 if (TYPE_PTRMEM_P (type))
4509 if (TREE_CODE (expr) == PTRMEM_CST)
4510 expr = cplus_expand_constant (expr);
4511 delta = get_delta_difference (c1, c2, /*force=*/1);
4512 if (!integer_zerop (delta))
4513 expr = cp_build_binary_op (PLUS_EXPR,
4514 build_nop (ptrdiff_type_node, expr),
4516 return build_nop (type, expr);
4519 return build_ptrmemfunc (TYPE_PTRMEMFUNC_FN_TYPE (type), expr,
4524 /* [expr.static.cast]
4526 An rvalue of type "pointer to cv void" can be explicitly
4527 converted to a pointer to object type. A value of type pointer
4528 to object converted to "pointer to cv void" and back to the
4529 original pointer type will have its original value. */
4530 if (TREE_CODE (intype) == POINTER_TYPE
4531 && VOID_TYPE_P (TREE_TYPE (intype))
4532 && TYPE_PTROB_P (type))
4534 check_for_casting_away_constness (intype, type, "static_cast");
4535 return build_nop (type, expr);
4538 error ("invalid static_cast from type `%T' to type `%T'", intype, type);
4539 return error_mark_node;
4543 build_reinterpret_cast (tree type, tree expr)
4547 if (type == error_mark_node || expr == error_mark_node)
4548 return error_mark_node;
4550 if (processing_template_decl)
4552 tree t = build_min (REINTERPRET_CAST_EXPR, type, expr);
4556 if (TREE_CODE (type) != REFERENCE_TYPE)
4558 expr = decay_conversion (expr);
4560 /* build_c_cast puts on a NOP_EXPR to make the result not an lvalue.
4561 Strip such NOP_EXPRs if VALUE is being used in non-lvalue context. */
4562 if (TREE_CODE (expr) == NOP_EXPR
4563 && TREE_TYPE (expr) == TREE_TYPE (TREE_OPERAND (expr, 0)))
4564 expr = TREE_OPERAND (expr, 0);
4567 intype = TREE_TYPE (expr);
4569 if (TREE_CODE (type) == REFERENCE_TYPE)
4571 if (! real_lvalue_p (expr))
4573 error ("invalid reinterpret_cast of an rvalue expression of type `%T' to type `%T'", intype, type);
4574 return error_mark_node;
4576 expr = build_unary_op (ADDR_EXPR, expr, 0);
4577 if (expr != error_mark_node)
4578 expr = build_reinterpret_cast
4579 (build_pointer_type (TREE_TYPE (type)), expr);
4580 if (expr != error_mark_node)
4581 expr = build_indirect_ref (expr, 0);
4584 else if (same_type_ignoring_top_level_qualifiers_p (intype, type))
4585 return build_static_cast (type, expr);
4587 if (TYPE_PTR_P (type) && (TREE_CODE (intype) == INTEGER_TYPE
4588 || TREE_CODE (intype) == ENUMERAL_TYPE))
4590 else if (TREE_CODE (type) == INTEGER_TYPE && TYPE_PTR_P (intype))
4592 if (TYPE_PRECISION (type) < TYPE_PRECISION (intype))
4593 pedwarn ("reinterpret_cast from `%T' to `%T' loses precision",
4596 else if ((TYPE_PTRFN_P (type) && TYPE_PTRFN_P (intype))
4597 || (TYPE_PTRMEMFUNC_P (type) && TYPE_PTRMEMFUNC_P (intype)))
4599 expr = decl_constant_value (expr);
4600 return fold (build1 (NOP_EXPR, type, expr));
4602 else if ((TYPE_PTRMEM_P (type) && TYPE_PTRMEM_P (intype))
4603 || (TYPE_PTROBV_P (type) && TYPE_PTROBV_P (intype)))
4605 check_for_casting_away_constness (intype, type, "reinterpret_cast");
4606 expr = decl_constant_value (expr);
4607 return fold (build1 (NOP_EXPR, type, expr));
4609 else if ((TYPE_PTRFN_P (type) && TYPE_PTROBV_P (intype))
4610 || (TYPE_PTRFN_P (intype) && TYPE_PTROBV_P (type)))
4612 pedwarn ("ISO C++ forbids casting between pointer-to-function and pointer-to-object");
4613 expr = decl_constant_value (expr);
4614 return fold (build1 (NOP_EXPR, type, expr));
4618 error ("invalid reinterpret_cast from type `%T' to type `%T'",
4620 return error_mark_node;
4623 return cp_convert (type, expr);
4627 build_const_cast (tree type, tree expr)
4631 if (type == error_mark_node || expr == error_mark_node)
4632 return error_mark_node;
4634 if (processing_template_decl)
4636 tree t = build_min (CONST_CAST_EXPR, type, expr);
4640 if (!POINTER_TYPE_P (type))
4641 error ("invalid use of const_cast with type `%T', which is not a pointer, reference, nor a pointer-to-data-member type", type);
4642 else if (TREE_CODE (TREE_TYPE (type)) == FUNCTION_TYPE)
4644 error ("invalid use of const_cast with type `%T', which is a pointer or reference to a function type", type);
4645 return error_mark_node;
4648 if (TREE_CODE (type) != REFERENCE_TYPE)
4650 expr = decay_conversion (expr);
4652 /* build_c_cast puts on a NOP_EXPR to make the result not an lvalue.
4653 Strip such NOP_EXPRs if VALUE is being used in non-lvalue context. */
4654 if (TREE_CODE (expr) == NOP_EXPR
4655 && TREE_TYPE (expr) == TREE_TYPE (TREE_OPERAND (expr, 0)))
4656 expr = TREE_OPERAND (expr, 0);
4659 intype = TREE_TYPE (expr);
4661 if (same_type_ignoring_top_level_qualifiers_p (intype, type))
4662 return build_static_cast (type, expr);
4663 else if (TREE_CODE (type) == REFERENCE_TYPE)
4665 if (! real_lvalue_p (expr))
4667 error ("invalid const_cast of an rvalue of type `%T' to type `%T'", intype, type);
4668 return error_mark_node;
4671 if (comp_ptr_ttypes_const (TREE_TYPE (type), intype))
4673 expr = build_unary_op (ADDR_EXPR, expr, 0);
4674 expr = build1 (NOP_EXPR, type, expr);
4675 return convert_from_reference (expr);
4678 else if (((TREE_CODE (type) == POINTER_TYPE
4679 && TREE_CODE (intype) == POINTER_TYPE)
4680 || (TYPE_PTRMEM_P (type) && TYPE_PTRMEM_P (intype)))
4681 && comp_ptr_ttypes_const (TREE_TYPE (type), TREE_TYPE (intype)))
4682 return cp_convert (type, expr);
4684 error ("invalid const_cast from type `%T' to type `%T'", intype, type);
4685 return error_mark_node;
4688 /* Build an expression representing a cast to type TYPE of expression EXPR.
4690 ALLOW_NONCONVERTING is true if we should allow non-converting constructors
4691 when doing the cast. */
4694 build_c_cast (tree type, tree expr)
4696 register tree value = expr;
4699 if (type == error_mark_node || expr == error_mark_node)
4700 return error_mark_node;
4702 if (processing_template_decl)
4704 tree t = build_min (CAST_EXPR, type,
4705 tree_cons (NULL_TREE, value, NULL_TREE));
4709 /* build_c_cast puts on a NOP_EXPR to make the result not an lvalue.
4710 Strip such NOP_EXPRs if VALUE is being used in non-lvalue context. */
4711 if (TREE_CODE (type) != REFERENCE_TYPE
4712 && TREE_CODE (value) == NOP_EXPR
4713 && TREE_TYPE (value) == TREE_TYPE (TREE_OPERAND (value, 0)))
4714 value = TREE_OPERAND (value, 0);
4716 if (TREE_CODE (type) == ARRAY_TYPE)
4718 /* Allow casting from T1* to T2[] because Cfront allows it.
4719 NIHCL uses it. It is not valid ISO C++ however. */
4720 if (TREE_CODE (TREE_TYPE (expr)) == POINTER_TYPE)
4722 pedwarn ("ISO C++ forbids casting to an array type `%T'", type);
4723 type = build_pointer_type (TREE_TYPE (type));
4727 error ("ISO C++ forbids casting to an array type `%T'", type);
4728 return error_mark_node;
4732 if (TREE_CODE (type) == FUNCTION_TYPE
4733 || TREE_CODE (type) == METHOD_TYPE)
4735 error ("invalid cast to function type `%T'", type);
4736 return error_mark_node;
4739 if (TREE_CODE (type) == VOID_TYPE)
4741 /* Conversion to void does not cause any of the normal function to
4742 * pointer, array to pointer and lvalue to rvalue decays. */
4744 value = convert_to_void (value, /*implicit=*/NULL);
4748 if (!complete_type_or_else (type, NULL_TREE))
4749 return error_mark_node;
4751 /* Convert functions and arrays to pointers and
4752 convert references to their expanded types,
4753 but don't convert any other types. If, however, we are
4754 casting to a class type, there's no reason to do this: the
4755 cast will only succeed if there is a converting constructor,
4756 and the default conversions will be done at that point. In
4757 fact, doing the default conversion here is actually harmful
4761 struct S { S(const A&); };
4763 since we don't want the array-to-pointer conversion done. */
4764 if (!IS_AGGR_TYPE (type))
4766 if (TREE_CODE (TREE_TYPE (value)) == FUNCTION_TYPE
4767 || (TREE_CODE (TREE_TYPE (value)) == METHOD_TYPE
4768 /* Don't do the default conversion on a ->* expression. */
4769 && ! (TREE_CODE (type) == POINTER_TYPE
4770 && bound_pmf_p (value)))
4771 || TREE_CODE (TREE_TYPE (value)) == ARRAY_TYPE
4772 || TREE_CODE (TREE_TYPE (value)) == REFERENCE_TYPE)
4773 value = decay_conversion (value);
4775 else if (TREE_CODE (TREE_TYPE (value)) == REFERENCE_TYPE)
4776 /* However, even for class types, we still need to strip away
4777 the reference type, since the call to convert_force below
4778 does not expect the input expression to be of reference
4780 value = convert_from_reference (value);
4782 otype = TREE_TYPE (value);
4784 /* Optionally warn about potentially worrisome casts. */
4787 && TREE_CODE (type) == POINTER_TYPE
4788 && TREE_CODE (otype) == POINTER_TYPE
4789 && !at_least_as_qualified_p (TREE_TYPE (type),
4791 warning ("cast from `%T' to `%T' discards qualifiers from pointer target type",
4794 if (TREE_CODE (type) == INTEGER_TYPE
4795 && TYPE_PTR_P (otype)
4796 && TYPE_PRECISION (type) != TYPE_PRECISION (otype))
4797 warning ("cast from pointer to integer of different size");
4799 if (TYPE_PTR_P (type)
4800 && TREE_CODE (otype) == INTEGER_TYPE
4801 && TYPE_PRECISION (type) != TYPE_PRECISION (otype)
4802 /* Don't warn about converting any constant. */
4803 && !TREE_CONSTANT (value))
4804 warning ("cast to pointer from integer of different size");
4806 if (TREE_CODE (type) == REFERENCE_TYPE)
4807 value = (convert_from_reference
4808 (convert_to_reference (type, value, CONV_C_CAST,
4809 LOOKUP_COMPLAIN, NULL_TREE)));
4814 value = decl_constant_value (value);
4817 value = convert_force (type, value, CONV_C_CAST);
4819 /* Ignore any integer overflow caused by the cast. */
4820 if (TREE_CODE (value) == INTEGER_CST)
4822 TREE_OVERFLOW (value) = TREE_OVERFLOW (ovalue);
4823 TREE_CONSTANT_OVERFLOW (value) = TREE_CONSTANT_OVERFLOW (ovalue);
4827 /* Warn about possible alignment problems. Do this here when we will have
4828 instantiated any necessary template types. */
4829 if (STRICT_ALIGNMENT && warn_cast_align
4830 && TREE_CODE (type) == POINTER_TYPE
4831 && TREE_CODE (otype) == POINTER_TYPE
4832 && TREE_CODE (TREE_TYPE (otype)) != VOID_TYPE
4833 && TREE_CODE (TREE_TYPE (otype)) != FUNCTION_TYPE
4834 && COMPLETE_TYPE_P (TREE_TYPE (otype))
4835 && COMPLETE_TYPE_P (TREE_TYPE (type))
4836 && TYPE_ALIGN (TREE_TYPE (type)) > TYPE_ALIGN (TREE_TYPE (otype)))
4837 warning ("cast from `%T' to `%T' increases required alignment of target type",
4840 /* Always produce some operator for an explicit cast,
4841 so we can tell (for -pedantic) that the cast is no lvalue. */
4842 if (TREE_CODE (type) != REFERENCE_TYPE && value == expr
4843 && real_lvalue_p (value))
4844 value = non_lvalue (value);
4849 /* Build an assignment expression of lvalue LHS from value RHS.
4850 MODIFYCODE is the code for a binary operator that we use
4851 to combine the old value of LHS with RHS to get the new value.
4852 Or else MODIFYCODE is NOP_EXPR meaning do a simple assignment.
4854 C++: If MODIFYCODE is INIT_EXPR, then leave references unbashed. */
4857 build_modify_expr (tree lhs, enum tree_code modifycode, tree rhs)
4859 register tree result;
4861 tree lhstype = TREE_TYPE (lhs);
4862 tree olhstype = lhstype;
4865 /* Avoid duplicate error messages from operands that had errors. */
4866 if (lhs == error_mark_node || rhs == error_mark_node)
4867 return error_mark_node;
4869 /* Handle control structure constructs used as "lvalues". */
4870 switch (TREE_CODE (lhs))
4872 /* Handle --foo = 5; as these are valid constructs in C++ */
4873 case PREDECREMENT_EXPR:
4874 case PREINCREMENT_EXPR:
4875 if (TREE_SIDE_EFFECTS (TREE_OPERAND (lhs, 0)))
4876 lhs = build (TREE_CODE (lhs), TREE_TYPE (lhs),
4877 stabilize_reference (TREE_OPERAND (lhs, 0)),
4878 TREE_OPERAND (lhs, 1));
4879 return build (COMPOUND_EXPR, lhstype,
4881 build_modify_expr (TREE_OPERAND (lhs, 0),
4884 /* Handle (a, b) used as an "lvalue". */
4886 newrhs = build_modify_expr (TREE_OPERAND (lhs, 1),
4888 if (newrhs == error_mark_node)
4889 return error_mark_node;
4890 return build (COMPOUND_EXPR, lhstype,
4891 TREE_OPERAND (lhs, 0), newrhs);
4894 if (TREE_SIDE_EFFECTS (TREE_OPERAND (lhs, 0)))
4895 lhs = build (TREE_CODE (lhs), TREE_TYPE (lhs),
4896 stabilize_reference (TREE_OPERAND (lhs, 0)),
4897 TREE_OPERAND (lhs, 1));
4898 newrhs = build_modify_expr (TREE_OPERAND (lhs, 0), modifycode, rhs);
4899 if (newrhs == error_mark_node)
4900 return error_mark_node;
4901 return build (COMPOUND_EXPR, lhstype, lhs, newrhs);
4903 /* Handle (a ? b : c) used as an "lvalue". */
4906 /* Produce (a ? (b = rhs) : (c = rhs))
4907 except that the RHS goes through a save-expr
4908 so the code to compute it is only emitted once. */
4910 tree preeval = NULL_TREE;
4912 rhs = stabilize_expr (rhs, &preeval);
4914 /* Check this here to avoid odd errors when trying to convert
4915 a throw to the type of the COND_EXPR. */
4916 if (!lvalue_or_else (lhs, "assignment"))
4917 return error_mark_node;
4919 cond = build_conditional_expr
4920 (TREE_OPERAND (lhs, 0),
4921 build_modify_expr (cp_convert (TREE_TYPE (lhs),
4922 TREE_OPERAND (lhs, 1)),
4924 build_modify_expr (cp_convert (TREE_TYPE (lhs),
4925 TREE_OPERAND (lhs, 2)),
4928 if (cond == error_mark_node)
4930 /* Make sure the code to compute the rhs comes out
4931 before the split. */
4932 return build (COMPOUND_EXPR, TREE_TYPE (lhs), preeval, cond);
4939 if (modifycode == INIT_EXPR)
4941 if (TREE_CODE (rhs) == CONSTRUCTOR)
4943 my_friendly_assert (same_type_p (TREE_TYPE (rhs), lhstype),
4945 result = build (INIT_EXPR, lhstype, lhs, rhs);
4946 TREE_SIDE_EFFECTS (result) = 1;
4949 else if (! IS_AGGR_TYPE (lhstype))
4950 /* Do the default thing */;
4953 result = build_special_member_call (lhs, complete_ctor_identifier,
4954 build_tree_list (NULL_TREE, rhs),
4955 TYPE_BINFO (lhstype),
4957 if (result == NULL_TREE)
4958 return error_mark_node;
4964 if (TREE_CODE (lhstype) == REFERENCE_TYPE)
4966 lhs = convert_from_reference (lhs);
4967 olhstype = lhstype = TREE_TYPE (lhs);
4969 lhs = require_complete_type (lhs);
4970 if (lhs == error_mark_node)
4971 return error_mark_node;
4973 if (modifycode == NOP_EXPR)
4975 /* `operator=' is not an inheritable operator. */
4976 if (! IS_AGGR_TYPE (lhstype))
4977 /* Do the default thing */;
4980 result = build_new_op (MODIFY_EXPR, LOOKUP_NORMAL,
4981 lhs, rhs, make_node (NOP_EXPR));
4982 if (result == NULL_TREE)
4983 return error_mark_node;
4990 /* A binary op has been requested. Combine the old LHS
4991 value with the RHS producing the value we should actually
4992 store into the LHS. */
4994 my_friendly_assert (!PROMOTES_TO_AGGR_TYPE (lhstype, REFERENCE_TYPE),
4996 lhs = stabilize_reference (lhs);
4997 newrhs = cp_build_binary_op (modifycode, lhs, rhs);
4998 if (newrhs == error_mark_node)
5000 error (" in evaluation of `%Q(%#T, %#T)'", modifycode,
5001 TREE_TYPE (lhs), TREE_TYPE (rhs));
5002 return error_mark_node;
5005 /* Now it looks like a plain assignment. */
5006 modifycode = NOP_EXPR;
5008 my_friendly_assert (TREE_CODE (lhstype) != REFERENCE_TYPE, 20011220);
5009 my_friendly_assert (TREE_CODE (TREE_TYPE (newrhs)) != REFERENCE_TYPE,
5013 /* Handle a cast used as an "lvalue".
5014 We have already performed any binary operator using the value as cast.
5015 Now convert the result to the cast type of the lhs,
5016 and then true type of the lhs and store it there;
5017 then convert result back to the cast type to be the value
5018 of the assignment. */
5020 switch (TREE_CODE (lhs))
5025 case FIX_TRUNC_EXPR:
5026 case FIX_FLOOR_EXPR:
5027 case FIX_ROUND_EXPR:
5030 tree inner_lhs = TREE_OPERAND (lhs, 0);
5033 if (TREE_CODE (TREE_TYPE (newrhs)) == ARRAY_TYPE
5034 || TREE_CODE (TREE_TYPE (newrhs)) == FUNCTION_TYPE
5035 || TREE_CODE (TREE_TYPE (newrhs)) == METHOD_TYPE
5036 || TREE_CODE (TREE_TYPE (newrhs)) == OFFSET_TYPE)
5037 newrhs = decay_conversion (newrhs);
5039 /* ISO C++ 5.4/1: The result is an lvalue if T is a reference
5040 type, otherwise the result is an rvalue. */
5041 if (! lvalue_p (lhs))
5042 pedwarn ("ISO C++ forbids cast to non-reference type used as lvalue");
5044 result = build_modify_expr (inner_lhs, NOP_EXPR,
5045 cp_convert (TREE_TYPE (inner_lhs),
5046 cp_convert (lhstype, newrhs)));
5047 if (result == error_mark_node)
5049 return cp_convert (TREE_TYPE (lhs), result);
5056 /* Now we have handled acceptable kinds of LHS that are not truly lvalues.
5057 Reject anything strange now. */
5059 if (!lvalue_or_else (lhs, "assignment"))
5060 return error_mark_node;
5062 /* Warn about modifying something that is `const'. Don't warn if
5063 this is initialization. */
5064 if (modifycode != INIT_EXPR
5065 && (TREE_READONLY (lhs) || CP_TYPE_CONST_P (lhstype)
5066 /* Functions are not modifiable, even though they are
5068 || TREE_CODE (TREE_TYPE (lhs)) == FUNCTION_TYPE
5069 || TREE_CODE (TREE_TYPE (lhs)) == METHOD_TYPE
5070 /* If it's an aggregate and any field is const, then it is
5071 effectively const. */
5072 || (CLASS_TYPE_P (lhstype)
5073 && C_TYPE_FIELDS_READONLY (lhstype))))
5074 readonly_error (lhs, "assignment", 0);
5076 /* If storing into a structure or union member, it has probably been
5077 given type `int'. Compute the type that would go with the actual
5078 amount of storage the member occupies. */
5080 if (TREE_CODE (lhs) == COMPONENT_REF
5081 && (TREE_CODE (lhstype) == INTEGER_TYPE
5082 || TREE_CODE (lhstype) == REAL_TYPE
5083 || TREE_CODE (lhstype) == ENUMERAL_TYPE))
5085 lhstype = TREE_TYPE (get_unwidened (lhs, 0));
5087 /* If storing in a field that is in actuality a short or narrower
5088 than one, we must store in the field in its actual type. */
5090 if (lhstype != TREE_TYPE (lhs))
5092 lhs = copy_node (lhs);
5093 TREE_TYPE (lhs) = lhstype;
5097 /* Convert new value to destination type. */
5099 if (TREE_CODE (lhstype) == ARRAY_TYPE)
5103 if (!same_or_base_type_p (TYPE_MAIN_VARIANT (lhstype),
5104 TYPE_MAIN_VARIANT (TREE_TYPE (rhs))))
5106 error ("incompatible types in assignment of `%T' to `%T'",
5107 TREE_TYPE (rhs), lhstype);
5108 return error_mark_node;
5111 /* Allow array assignment in compiler-generated code. */
5112 if (! DECL_ARTIFICIAL (current_function_decl))
5113 pedwarn ("ISO C++ forbids assignment of arrays");
5115 from_array = TREE_CODE (TREE_TYPE (newrhs)) == ARRAY_TYPE
5116 ? 1 + (modifycode != INIT_EXPR): 0;
5117 return build_vec_init (lhs, NULL_TREE, newrhs, from_array);
5120 if (modifycode == INIT_EXPR)
5121 newrhs = convert_for_initialization (lhs, lhstype, newrhs, LOOKUP_NORMAL,
5122 "initialization", NULL_TREE, 0);
5125 /* Avoid warnings on enum bit fields. */
5126 if (TREE_CODE (olhstype) == ENUMERAL_TYPE
5127 && TREE_CODE (lhstype) == INTEGER_TYPE)
5129 newrhs = convert_for_assignment (olhstype, newrhs, "assignment",
5131 newrhs = convert_force (lhstype, newrhs, 0);
5134 newrhs = convert_for_assignment (lhstype, newrhs, "assignment",
5136 if (TREE_CODE (newrhs) == CALL_EXPR
5137 && TYPE_NEEDS_CONSTRUCTING (lhstype))
5138 newrhs = build_cplus_new (lhstype, newrhs);
5140 /* Can't initialize directly from a TARGET_EXPR, since that would
5141 cause the lhs to be constructed twice, and possibly result in
5142 accidental self-initialization. So we force the TARGET_EXPR to be
5143 expanded without a target. */
5144 if (TREE_CODE (newrhs) == TARGET_EXPR)
5145 newrhs = build (COMPOUND_EXPR, TREE_TYPE (newrhs), newrhs,
5146 TREE_OPERAND (newrhs, 0));
5149 if (newrhs == error_mark_node)
5150 return error_mark_node;
5152 result = build (modifycode == NOP_EXPR ? MODIFY_EXPR : INIT_EXPR,
5153 lhstype, lhs, newrhs);
5155 TREE_SIDE_EFFECTS (result) = 1;
5157 /* If we got the LHS in a different type for storing in,
5158 convert the result back to the nominal type of LHS
5159 so that the value we return always has the same type
5160 as the LHS argument. */
5162 if (olhstype == TREE_TYPE (result))
5164 /* Avoid warnings converting integral types back into enums
5165 for enum bit fields. */
5166 if (TREE_CODE (TREE_TYPE (result)) == INTEGER_TYPE
5167 && TREE_CODE (olhstype) == ENUMERAL_TYPE)
5169 result = build (COMPOUND_EXPR, olhstype, result, olhs);
5170 TREE_NO_UNUSED_WARNING (result) = 1;
5173 return convert_for_assignment (olhstype, result, "assignment",
5178 build_x_modify_expr (tree lhs, enum tree_code modifycode, tree rhs)
5180 if (processing_template_decl)
5181 return build_min_nt (MODOP_EXPR, lhs,
5182 build_min_nt (modifycode, NULL_TREE, NULL_TREE), rhs);
5184 if (modifycode != NOP_EXPR)
5186 tree rval = build_new_op (MODIFY_EXPR, LOOKUP_NORMAL, lhs, rhs,
5187 make_node (modifycode));
5191 return build_modify_expr (lhs, modifycode, rhs);
5195 /* Get difference in deltas for different pointer to member function
5196 types. Returns an integer constant of type PTRDIFF_TYPE_NODE. If
5197 the conversion is invalid, the constant is zero. If FORCE is true,
5198 then allow reverse conversions as well.
5200 Note that the naming of FROM and TO is kind of backwards; the return
5201 value is what we add to a TO in order to get a FROM. They are named
5202 this way because we call this function to find out how to convert from
5203 a pointer to member of FROM to a pointer to member of TO. */
5206 get_delta_difference (tree from, tree to, int force)
5212 binfo = lookup_base (to, from, ba_check, &kind);
5213 if (kind == bk_inaccessible || kind == bk_ambig)
5215 error (" in pointer to member function conversion");
5222 error_not_base_type (from, to);
5223 error (" in pointer to member conversion");
5226 binfo = lookup_base (from, to, ba_check, &kind);
5229 virt_binfo = binfo_from_vbase (binfo);
5232 /* This is a reinterpret cast, we choose to do nothing. */
5233 warning ("pointer to member cast via virtual base `%T'",
5234 BINFO_TYPE (virt_binfo));
5237 return convert_to_integer (ptrdiff_type_node,
5238 size_diffop (size_zero_node,
5239 BINFO_OFFSET (binfo)));
5242 virt_binfo = binfo_from_vbase (binfo);
5244 return convert_to_integer (ptrdiff_type_node, BINFO_OFFSET (binfo));
5246 /* This is a reinterpret cast, we choose to do nothing. */
5248 warning ("pointer to member cast via virtual base `%T'",
5249 BINFO_TYPE (virt_binfo));
5251 error ("pointer to member conversion via virtual base `%T'",
5252 BINFO_TYPE (virt_binfo));
5255 return convert_to_integer(ptrdiff_type_node, integer_zero_node);
5258 /* Return a constructor for the pointer-to-member-function TYPE using
5259 the other components as specified. */
5262 build_ptrmemfunc1 (tree type, tree delta, tree pfn)
5268 /* Pull the FIELD_DECLs out of the type. */
5269 pfn_field = TYPE_FIELDS (type);
5270 delta_field = TREE_CHAIN (pfn_field);
5272 /* Make sure DELTA has the type we want. */
5273 delta = convert_and_check (delta_type_node, delta);
5275 /* Finish creating the initializer. */
5276 u = tree_cons (pfn_field, pfn,
5277 build_tree_list (delta_field, delta));
5278 u = build_constructor (type, u);
5279 TREE_CONSTANT (u) = TREE_CONSTANT (pfn) && TREE_CONSTANT (delta);
5280 TREE_STATIC (u) = (TREE_CONSTANT (u)
5281 && (initializer_constant_valid_p (pfn, TREE_TYPE (pfn))
5283 && (initializer_constant_valid_p (delta, TREE_TYPE (delta))
5288 /* Build a constructor for a pointer to member function. It can be
5289 used to initialize global variables, local variable, or used
5290 as a value in expressions. TYPE is the POINTER to METHOD_TYPE we
5293 If FORCE is nonzero, then force this conversion, even if
5294 we would rather not do it. Usually set when using an explicit
5297 Return error_mark_node, if something goes wrong. */
5300 build_ptrmemfunc (tree type, tree pfn, int force)
5306 if (error_operand_p (pfn))
5307 return error_mark_node;
5309 pfn_type = TREE_TYPE (pfn);
5310 to_type = build_ptrmemfunc_type (type);
5312 /* Handle multiple conversions of pointer to member functions. */
5313 if (TYPE_PTRMEMFUNC_P (pfn_type))
5315 tree delta = NULL_TREE;
5316 tree npfn = NULL_TREE;
5320 && !can_convert_arg (to_type, TREE_TYPE (pfn), pfn))
5321 error ("invalid conversion to type `%T' from type `%T'",
5324 n = get_delta_difference (TYPE_PTRMEMFUNC_OBJECT_TYPE (pfn_type),
5325 TYPE_PTRMEMFUNC_OBJECT_TYPE (to_type),
5328 /* We don't have to do any conversion to convert a
5329 pointer-to-member to its own type. But, we don't want to
5330 just return a PTRMEM_CST if there's an explicit cast; that
5331 cast should make the expression an invalid template argument. */
5332 if (TREE_CODE (pfn) != PTRMEM_CST)
5334 if (same_type_p (to_type, pfn_type))
5336 else if (integer_zerop (n))
5337 return build_reinterpret_cast (to_type, pfn);
5340 if (TREE_SIDE_EFFECTS (pfn))
5341 pfn = save_expr (pfn);
5343 /* Obtain the function pointer and the current DELTA. */
5344 if (TREE_CODE (pfn) == PTRMEM_CST)
5345 expand_ptrmemfunc_cst (pfn, &delta, &npfn);
5348 npfn = build_ptrmemfunc_access_expr (pfn, pfn_identifier);
5349 delta = build_ptrmemfunc_access_expr (pfn, delta_identifier);
5352 /* Just adjust the DELTA field. */
5353 my_friendly_assert (TREE_TYPE (delta) == ptrdiff_type_node, 20030727);
5354 if (TARGET_PTRMEMFUNC_VBIT_LOCATION == ptrmemfunc_vbit_in_delta)
5355 n = cp_build_binary_op (LSHIFT_EXPR, n, integer_one_node);
5356 delta = cp_build_binary_op (PLUS_EXPR, delta, n);
5357 return build_ptrmemfunc1 (to_type, delta, npfn);
5360 /* Handle null pointer to member function conversions. */
5361 if (integer_zerop (pfn))
5363 pfn = build_c_cast (type, integer_zero_node);
5364 return build_ptrmemfunc1 (to_type,
5369 if (type_unknown_p (pfn))
5370 return instantiate_type (type, pfn, tf_error | tf_warning);
5372 fn = TREE_OPERAND (pfn, 0);
5373 my_friendly_assert (TREE_CODE (fn) == FUNCTION_DECL, 0);
5374 return make_ptrmem_cst (to_type, fn);
5377 /* Return the DELTA, IDX, PFN, and DELTA2 values for the PTRMEM_CST
5380 ??? There is no consistency as to the types returned for the above
5381 values. Some code acts as if its a sizetype and some as if its
5382 integer_type_node. */
5385 expand_ptrmemfunc_cst (tree cst, tree *delta, tree *pfn)
5387 tree type = TREE_TYPE (cst);
5388 tree fn = PTRMEM_CST_MEMBER (cst);
5389 tree ptr_class, fn_class;
5391 my_friendly_assert (TREE_CODE (fn) == FUNCTION_DECL, 0);
5393 /* The class that the function belongs to. */
5394 fn_class = DECL_CONTEXT (fn);
5396 /* The class that we're creating a pointer to member of. */
5397 ptr_class = TYPE_PTRMEMFUNC_OBJECT_TYPE (type);
5399 /* First, calculate the adjustment to the function's class. */
5400 *delta = get_delta_difference (fn_class, ptr_class, /*force=*/0);
5402 if (!DECL_VIRTUAL_P (fn))
5403 *pfn = convert (TYPE_PTRMEMFUNC_FN_TYPE (type), build_addr_func (fn));
5406 /* If we're dealing with a virtual function, we have to adjust 'this'
5407 again, to point to the base which provides the vtable entry for
5408 fn; the call will do the opposite adjustment. */
5409 tree orig_class = DECL_CONTEXT (fn);
5410 tree binfo = binfo_or_else (orig_class, fn_class);
5411 *delta = fold (build (PLUS_EXPR, TREE_TYPE (*delta),
5412 *delta, BINFO_OFFSET (binfo)));
5414 /* We set PFN to the vtable offset at which the function can be
5415 found, plus one (unless ptrmemfunc_vbit_in_delta, in which
5416 case delta is shifted left, and then incremented). */
5417 *pfn = DECL_VINDEX (fn);
5418 *pfn = fold (build (MULT_EXPR, integer_type_node, *pfn,
5419 TYPE_SIZE_UNIT (vtable_entry_type)));
5421 switch (TARGET_PTRMEMFUNC_VBIT_LOCATION)
5423 case ptrmemfunc_vbit_in_pfn:
5424 *pfn = fold (build (PLUS_EXPR, integer_type_node, *pfn,
5428 case ptrmemfunc_vbit_in_delta:
5429 *delta = fold (build (LSHIFT_EXPR, TREE_TYPE (*delta),
5430 *delta, integer_one_node));
5431 *delta = fold (build (PLUS_EXPR, TREE_TYPE (*delta),
5432 *delta, integer_one_node));
5439 *pfn = fold (build1 (NOP_EXPR, TYPE_PTRMEMFUNC_FN_TYPE (type),
5444 /* Return an expression for PFN from the pointer-to-member function
5448 pfn_from_ptrmemfunc (tree t)
5450 if (TREE_CODE (t) == PTRMEM_CST)
5455 expand_ptrmemfunc_cst (t, &delta, &pfn);
5460 return build_ptrmemfunc_access_expr (t, pfn_identifier);
5463 /* Expression EXPR is about to be implicitly converted to TYPE. Warn
5464 if this is a potentially dangerous thing to do. Returns a possibly
5468 dubious_conversion_warnings (tree type, tree expr,
5469 const char *errtype, tree fndecl, int parmnum)
5471 type = non_reference (type);
5473 /* Issue warnings about peculiar, but valid, uses of NULL. */
5474 if (ARITHMETIC_TYPE_P (type) && expr == null_node)
5477 warning ("passing NULL used for non-pointer %s %P of `%D'",
5478 errtype, parmnum, fndecl);
5480 warning ("%s to non-pointer type `%T' from NULL", errtype, type);
5483 /* Warn about assigning a floating-point type to an integer type. */
5484 if (TREE_CODE (TREE_TYPE (expr)) == REAL_TYPE
5485 && TREE_CODE (type) == INTEGER_TYPE)
5488 warning ("passing `%T' for %s %P of `%D'",
5489 TREE_TYPE (expr), errtype, parmnum, fndecl);
5491 warning ("%s to `%T' from `%T'", errtype, type, TREE_TYPE (expr));
5493 /* And warn about assigning a negative value to an unsigned
5495 else if (TREE_UNSIGNED (type) && TREE_CODE (type) != BOOLEAN_TYPE)
5497 if (TREE_CODE (expr) == INTEGER_CST
5498 && TREE_NEGATED_INT (expr))
5501 warning ("passing negative value `%E' for %s %P of `%D'",
5502 expr, errtype, parmnum, fndecl);
5504 warning ("%s of negative value `%E' to `%T'",
5505 errtype, expr, type);
5508 overflow_warning (expr);
5510 if (TREE_CONSTANT (expr))
5516 /* Convert value RHS to type TYPE as preparation for an assignment to
5517 an lvalue of type TYPE. ERRTYPE is a string to use in error
5518 messages: "assignment", "return", etc. If FNDECL is non-NULL, we
5519 are doing the conversion in order to pass the PARMNUMth argument of
5523 convert_for_assignment (tree type, tree rhs,
5524 const char *errtype, tree fndecl, int parmnum)
5526 register tree rhstype;
5527 register enum tree_code coder;
5529 /* Strip NON_LVALUE_EXPRs since we aren't using as an lvalue. */
5530 if (TREE_CODE (rhs) == NON_LVALUE_EXPR)
5531 rhs = TREE_OPERAND (rhs, 0);
5533 rhstype = TREE_TYPE (rhs);
5534 coder = TREE_CODE (rhstype);
5536 if (TREE_CODE (type) == VECTOR_TYPE && coder == VECTOR_TYPE
5537 && ((*targetm.vector_opaque_p) (type)
5538 || (*targetm.vector_opaque_p) (rhstype)))
5539 return convert (type, rhs);
5541 if (rhs == error_mark_node || rhstype == error_mark_node)
5542 return error_mark_node;
5543 if (TREE_CODE (rhs) == TREE_LIST && TREE_VALUE (rhs) == error_mark_node)
5544 return error_mark_node;
5546 rhs = dubious_conversion_warnings (type, rhs, errtype, fndecl, parmnum);
5548 /* The RHS of an assignment cannot have void type. */
5549 if (coder == VOID_TYPE)
5551 error ("void value not ignored as it ought to be");
5552 return error_mark_node;
5555 /* Simplify the RHS if possible. */
5556 if (TREE_CODE (rhs) == CONST_DECL)
5557 rhs = DECL_INITIAL (rhs);
5559 /* We do not use decl_constant_value here because of this case:
5561 const char* const s = "s";
5563 The conversion rules for a string literal are more lax than for a
5564 variable; in particular, a string literal can be converted to a
5565 "char *" but the variable "s" cannot be converted in the same
5566 way. If the conversion is allowed, the optimization should be
5567 performed while creating the converted expression. */
5571 The expression is implicitly converted (clause _conv_) to the
5572 cv-unqualified type of the left operand.
5574 We allow bad conversions here because by the time we get to this point
5575 we are committed to doing the conversion. If we end up doing a bad
5576 conversion, convert_like will complain. */
5577 if (!can_convert_arg_bad (type, rhstype, rhs))
5579 /* When -Wno-pmf-conversions is use, we just silently allow
5580 conversions from pointers-to-members to plain pointers. If
5581 the conversion doesn't work, cp_convert will complain. */
5583 && TYPE_PTR_P (type)
5584 && TYPE_PTRMEMFUNC_P (rhstype))
5585 rhs = cp_convert (strip_top_quals (type), rhs);
5588 /* If the right-hand side has unknown type, then it is an
5589 overloaded function. Call instantiate_type to get error
5591 if (rhstype == unknown_type_node)
5592 instantiate_type (type, rhs, tf_error | tf_warning);
5594 error ("cannot convert `%T' to `%T' for argument `%P' to `%D'",
5595 rhstype, type, parmnum, fndecl);
5597 error ("cannot convert `%T' to `%T' in %s", rhstype, type,
5599 return error_mark_node;
5602 return perform_implicit_conversion (strip_top_quals (type), rhs);
5605 /* Convert RHS to be of type TYPE.
5606 If EXP is nonzero, it is the target of the initialization.
5607 ERRTYPE is a string to use in error messages.
5609 Two major differences between the behavior of
5610 `convert_for_assignment' and `convert_for_initialization'
5611 are that references are bashed in the former, while
5612 copied in the latter, and aggregates are assigned in
5613 the former (operator=) while initialized in the
5616 If using constructor make sure no conversion operator exists, if one does
5617 exist, an ambiguity exists.
5619 If flags doesn't include LOOKUP_COMPLAIN, don't complain about anything. */
5622 convert_for_initialization (tree exp, tree type, tree rhs, int flags,
5623 const char *errtype, tree fndecl, int parmnum)
5625 register enum tree_code codel = TREE_CODE (type);
5626 register tree rhstype;
5627 register enum tree_code coder;
5629 /* build_c_cast puts on a NOP_EXPR to make the result not an lvalue.
5630 Strip such NOP_EXPRs, since RHS is used in non-lvalue context. */
5631 if (TREE_CODE (rhs) == NOP_EXPR
5632 && TREE_TYPE (rhs) == TREE_TYPE (TREE_OPERAND (rhs, 0))
5633 && codel != REFERENCE_TYPE)
5634 rhs = TREE_OPERAND (rhs, 0);
5636 if (rhs == error_mark_node
5637 || (TREE_CODE (rhs) == TREE_LIST && TREE_VALUE (rhs) == error_mark_node))
5638 return error_mark_node;
5640 if (TREE_CODE (TREE_TYPE (rhs)) == REFERENCE_TYPE)
5641 rhs = convert_from_reference (rhs);
5643 if ((TREE_CODE (TREE_TYPE (rhs)) == ARRAY_TYPE
5644 && TREE_CODE (type) != ARRAY_TYPE
5645 && (TREE_CODE (type) != REFERENCE_TYPE
5646 || TREE_CODE (TREE_TYPE (type)) != ARRAY_TYPE))
5647 || (TREE_CODE (TREE_TYPE (rhs)) == FUNCTION_TYPE
5648 && (TREE_CODE (type) != REFERENCE_TYPE
5649 || TREE_CODE (TREE_TYPE (type)) != FUNCTION_TYPE))
5650 || TREE_CODE (TREE_TYPE (rhs)) == METHOD_TYPE)
5651 rhs = decay_conversion (rhs);
5653 rhstype = TREE_TYPE (rhs);
5654 coder = TREE_CODE (rhstype);
5656 if (coder == ERROR_MARK)
5657 return error_mark_node;
5659 /* We accept references to incomplete types, so we can
5660 return here before checking if RHS is of complete type. */
5662 if (codel == REFERENCE_TYPE)
5664 /* This should eventually happen in convert_arguments. */
5665 int savew = 0, savee = 0;
5668 savew = warningcount, savee = errorcount;
5669 rhs = initialize_reference (type, rhs, /*decl=*/NULL_TREE);
5672 if (warningcount > savew)
5673 cp_warning_at ("in passing argument %P of `%+D'", parmnum, fndecl);
5674 else if (errorcount > savee)
5675 cp_error_at ("in passing argument %P of `%+D'", parmnum, fndecl);
5681 exp = require_complete_type (exp);
5682 if (exp == error_mark_node)
5683 return error_mark_node;
5685 rhstype = non_reference (rhstype);
5687 type = complete_type (type);
5689 if (IS_AGGR_TYPE (type))
5690 return ocp_convert (type, rhs, CONV_IMPLICIT|CONV_FORCE_TEMP, flags);
5692 return convert_for_assignment (type, rhs, errtype, fndecl, parmnum);
5695 /* Expand an ASM statement with operands, handling output operands
5696 that are not variables or INDIRECT_REFS by transforming such
5697 cases into cases that expand_asm_operands can handle.
5699 Arguments are same as for expand_asm_operands.
5701 We don't do default conversions on all inputs, because it can screw
5702 up operands that are expected to be in memory. */
5705 c_expand_asm_operands (tree string, tree outputs, tree inputs, tree clobbers,
5706 int vol, const char *filename, int line)
5708 int noutputs = list_length (outputs);
5710 /* o[I] is the place that output number I should be written. */
5711 register tree *o = alloca (noutputs * sizeof (tree));
5714 /* Record the contents of OUTPUTS before it is modified. */
5715 for (i = 0, tail = outputs; tail; tail = TREE_CHAIN (tail), i++)
5716 o[i] = TREE_VALUE (tail);
5718 /* Generate the ASM_OPERANDS insn;
5719 store into the TREE_VALUEs of OUTPUTS some trees for
5720 where the values were actually stored. */
5721 expand_asm_operands (string, outputs, inputs, clobbers, vol, filename, line);
5723 /* Copy all the intermediate outputs into the specified outputs. */
5724 for (i = 0, tail = outputs; tail; tail = TREE_CHAIN (tail), i++)
5726 if (o[i] != TREE_VALUE (tail))
5728 expand_expr (build_modify_expr (o[i], NOP_EXPR, TREE_VALUE (tail)),
5729 const0_rtx, VOIDmode, EXPAND_NORMAL);
5732 /* Restore the original value so that it's correct the next
5733 time we expand this function. */
5734 TREE_VALUE (tail) = o[i];
5736 /* Detect modification of read-only values.
5737 (Otherwise done by build_modify_expr.) */
5740 tree type = TREE_TYPE (o[i]);
5741 if (type != error_mark_node
5742 && (CP_TYPE_CONST_P (type)
5743 || (CLASS_TYPE_P (type) && C_TYPE_FIELDS_READONLY (type))))
5744 readonly_error (o[i], "modification by `asm'", 1);
5748 /* Those MODIFY_EXPRs could do autoincrements. */
5752 /* If RETVAL is the address of, or a reference to, a local variable or
5753 temporary give an appropriate warning. */
5756 maybe_warn_about_returning_address_of_local (tree retval)
5758 tree valtype = TREE_TYPE (DECL_RESULT (current_function_decl));
5759 tree whats_returned = retval;
5763 if (TREE_CODE (whats_returned) == COMPOUND_EXPR)
5764 whats_returned = TREE_OPERAND (whats_returned, 1);
5765 else if (TREE_CODE (whats_returned) == CONVERT_EXPR
5766 || TREE_CODE (whats_returned) == NON_LVALUE_EXPR
5767 || TREE_CODE (whats_returned) == NOP_EXPR)
5768 whats_returned = TREE_OPERAND (whats_returned, 0);
5773 if (TREE_CODE (whats_returned) != ADDR_EXPR)
5775 whats_returned = TREE_OPERAND (whats_returned, 0);
5777 if (TREE_CODE (valtype) == REFERENCE_TYPE)
5779 if (TREE_CODE (whats_returned) == AGGR_INIT_EXPR
5780 || TREE_CODE (whats_returned) == TARGET_EXPR)
5782 warning ("returning reference to temporary");
5785 if (TREE_CODE (whats_returned) == VAR_DECL
5786 && DECL_NAME (whats_returned)
5787 && TEMP_NAME_P (DECL_NAME (whats_returned)))
5789 warning ("reference to non-lvalue returned");
5794 if (TREE_CODE (whats_returned) == VAR_DECL
5795 && DECL_NAME (whats_returned)
5796 && DECL_FUNCTION_SCOPE_P (whats_returned)
5797 && !(TREE_STATIC (whats_returned)
5798 || TREE_PUBLIC (whats_returned)))
5800 if (TREE_CODE (valtype) == REFERENCE_TYPE)
5801 cp_warning_at ("reference to local variable `%D' returned",
5804 cp_warning_at ("address of local variable `%D' returned",
5810 /* Check that returning RETVAL from the current function is valid.
5811 Return an expression explicitly showing all conversions required to
5812 change RETVAL into the function return type, and to assign it to
5813 the DECL_RESULT for the function. */
5816 check_return_expr (tree retval)
5819 /* The type actually returned by the function, after any
5822 int fn_returns_value_p;
5824 /* A `volatile' function is one that isn't supposed to return, ever.
5825 (This is a G++ extension, used to get better code for functions
5826 that call the `volatile' function.) */
5827 if (TREE_THIS_VOLATILE (current_function_decl))
5828 warning ("function declared `noreturn' has a `return' statement");
5830 /* Check for various simple errors. */
5831 if (DECL_DESTRUCTOR_P (current_function_decl))
5834 error ("returning a value from a destructor");
5837 else if (DECL_CONSTRUCTOR_P (current_function_decl))
5839 if (in_function_try_handler)
5840 /* If a return statement appears in a handler of the
5841 function-try-block of a constructor, the program is ill-formed. */
5842 error ("cannot return from a handler of a function-try-block of a constructor");
5844 /* You can't return a value from a constructor. */
5845 error ("returning a value from a constructor");
5849 if (processing_template_decl)
5851 current_function_returns_value = 1;
5855 /* When no explicit return-value is given in a function with a named
5856 return value, the named return value is used. */
5857 result = DECL_RESULT (current_function_decl);
5858 valtype = TREE_TYPE (result);
5859 my_friendly_assert (valtype != NULL_TREE, 19990924);
5860 fn_returns_value_p = !VOID_TYPE_P (valtype);
5861 if (!retval && DECL_NAME (result) && fn_returns_value_p)
5864 /* Check for a return statement with no return value in a function
5865 that's supposed to return a value. */
5866 if (!retval && fn_returns_value_p)
5868 pedwarn ("return-statement with no value, in function returning '%T'",
5870 /* Clear this, so finish_function won't say that we reach the
5871 end of a non-void function (which we don't, we gave a
5873 current_function_returns_null = 0;
5875 /* Check for a return statement with a value in a function that
5876 isn't supposed to return a value. */
5877 else if (retval && !fn_returns_value_p)
5879 if (VOID_TYPE_P (TREE_TYPE (retval)))
5880 /* You can return a `void' value from a function of `void'
5881 type. In that case, we have to evaluate the expression for
5882 its side-effects. */
5883 finish_expr_stmt (retval);
5885 pedwarn ("return-statement with a value, in function "
5886 "returning 'void'");
5888 current_function_returns_null = 1;
5890 /* There's really no value to return, after all. */
5894 /* Remember that this function can sometimes return without a
5896 current_function_returns_null = 1;
5898 /* Remember that this function did return a value. */
5899 current_function_returns_value = 1;
5901 /* Only operator new(...) throw(), can return NULL [expr.new/13]. */
5902 if ((DECL_OVERLOADED_OPERATOR_P (current_function_decl) == NEW_EXPR
5903 || DECL_OVERLOADED_OPERATOR_P (current_function_decl) == VEC_NEW_EXPR)
5904 && !TYPE_NOTHROW_P (TREE_TYPE (current_function_decl))
5906 && null_ptr_cst_p (retval))
5907 warning ("`operator new' must not return NULL unless it is declared `throw()' (or -fcheck-new is in effect)");
5909 /* Effective C++ rule 15. See also start_function. */
5911 && DECL_NAME (current_function_decl) == ansi_assopname(NOP_EXPR)
5912 && retval != current_class_ref)
5913 warning ("`operator=' should return a reference to `*this'");
5915 /* The fabled Named Return Value optimization, as per [class.copy]/15:
5917 [...] For a function with a class return type, if the expression
5918 in the return statement is the name of a local object, and the cv-
5919 unqualified type of the local object is the same as the function
5920 return type, an implementation is permitted to omit creating the tem-
5921 porary object to hold the function return value [...]
5923 So, if this is a value-returning function that always returns the same
5924 local variable, remember it.
5926 It might be nice to be more flexible, and choose the first suitable
5927 variable even if the function sometimes returns something else, but
5928 then we run the risk of clobbering the variable we chose if the other
5929 returned expression uses the chosen variable somehow. And people expect
5930 this restriction, anyway. (jason 2000-11-19)
5932 See finish_function, genrtl_start_function, and declare_return_variable
5933 for other pieces of this optimization. */
5935 if (fn_returns_value_p && flag_elide_constructors)
5937 if (retval != NULL_TREE
5938 && (current_function_return_value == NULL_TREE
5939 || current_function_return_value == retval)
5940 && TREE_CODE (retval) == VAR_DECL
5941 && DECL_CONTEXT (retval) == current_function_decl
5942 && ! TREE_STATIC (retval)
5943 && (DECL_ALIGN (retval)
5944 >= DECL_ALIGN (DECL_RESULT (current_function_decl)))
5945 && same_type_p ((TYPE_MAIN_VARIANT
5946 (TREE_TYPE (retval))),
5948 (TREE_TYPE (TREE_TYPE (current_function_decl))))))
5949 current_function_return_value = retval;
5951 current_function_return_value = error_mark_node;
5954 /* We don't need to do any conversions when there's nothing being
5956 if (!retval || retval == error_mark_node)
5959 /* Do any required conversions. */
5960 if (retval == result || DECL_CONSTRUCTOR_P (current_function_decl))
5961 /* No conversions are required. */
5965 /* The type the function is declared to return. */
5966 tree functype = TREE_TYPE (TREE_TYPE (current_function_decl));
5968 /* First convert the value to the function's return type, then
5969 to the type of return value's location to handle the
5970 case that functype is smaller than the valtype. */
5971 retval = convert_for_initialization
5972 (NULL_TREE, functype, retval, LOOKUP_NORMAL|LOOKUP_ONLYCONVERTING,
5973 "return", NULL_TREE, 0);
5974 retval = convert (valtype, retval);
5976 /* If the conversion failed, treat this just like `return;'. */
5977 if (retval == error_mark_node)
5979 /* We can't initialize a register from a AGGR_INIT_EXPR. */
5980 else if (! current_function_returns_struct
5981 && TREE_CODE (retval) == TARGET_EXPR
5982 && TREE_CODE (TREE_OPERAND (retval, 1)) == AGGR_INIT_EXPR)
5983 retval = build (COMPOUND_EXPR, TREE_TYPE (retval), retval,
5984 TREE_OPERAND (retval, 0));
5986 maybe_warn_about_returning_address_of_local (retval);
5989 /* Actually copy the value returned into the appropriate location. */
5990 if (retval && retval != result)
5991 retval = build (INIT_EXPR, TREE_TYPE (result), result, retval);
5997 /* Returns nonzero if the pointer-type FROM can be converted to the
5998 pointer-type TO via a qualification conversion. If CONSTP is -1,
5999 then we return nonzero if the pointers are similar, and the
6000 cv-qualification signature of FROM is a proper subset of that of TO.
6002 If CONSTP is positive, then all outer pointers have been
6006 comp_ptr_ttypes_real (tree to, tree from, int constp)
6008 bool to_more_cv_qualified = false;
6010 for (; ; to = TREE_TYPE (to), from = TREE_TYPE (from))
6012 if (TREE_CODE (to) != TREE_CODE (from))
6015 if (TREE_CODE (from) == OFFSET_TYPE
6016 && !same_type_p (TYPE_OFFSET_BASETYPE (from),
6017 TYPE_OFFSET_BASETYPE (to)))
6020 /* Const and volatile mean something different for function types,
6021 so the usual checks are not appropriate. */
6022 if (TREE_CODE (to) != FUNCTION_TYPE && TREE_CODE (to) != METHOD_TYPE)
6024 if (!at_least_as_qualified_p (to, from))
6027 if (!at_least_as_qualified_p (from, to))
6031 to_more_cv_qualified = true;
6035 constp &= TYPE_READONLY (to);
6038 if (TREE_CODE (to) != POINTER_TYPE && !TYPE_PTRMEM_P (to))
6039 return ((constp >= 0 || to_more_cv_qualified)
6040 && same_type_ignoring_top_level_qualifiers_p (to, from));
6044 /* When comparing, say, char ** to char const **, this function takes
6045 the 'char *' and 'char const *'. Do not pass non-pointer/reference
6046 types to this function. */
6049 comp_ptr_ttypes (tree to, tree from)
6051 return comp_ptr_ttypes_real (to, from, 1);
6054 /* Returns 1 if to and from are (possibly multi-level) pointers to the same
6055 type or inheritance-related types, regardless of cv-quals. */
6058 ptr_reasonably_similar (tree to, tree from)
6060 for (; ; to = TREE_TYPE (to), from = TREE_TYPE (from))
6062 /* Any target type is similar enough to void. */
6063 if (TREE_CODE (to) == VOID_TYPE
6064 || TREE_CODE (from) == VOID_TYPE)
6067 if (TREE_CODE (to) != TREE_CODE (from))
6070 if (TREE_CODE (from) == OFFSET_TYPE
6071 && comptypes (TYPE_OFFSET_BASETYPE (to),
6072 TYPE_OFFSET_BASETYPE (from),
6073 COMPARE_BASE | COMPARE_DERIVED))
6076 if (TREE_CODE (to) == INTEGER_TYPE
6077 && TYPE_PRECISION (to) == TYPE_PRECISION (from))
6080 if (TREE_CODE (to) == FUNCTION_TYPE)
6083 if (TREE_CODE (to) != POINTER_TYPE)
6085 (TYPE_MAIN_VARIANT (to), TYPE_MAIN_VARIANT (from),
6086 COMPARE_BASE | COMPARE_DERIVED);
6090 /* Like comp_ptr_ttypes, for const_cast. */
6093 comp_ptr_ttypes_const (tree to, tree from)
6095 for (; ; to = TREE_TYPE (to), from = TREE_TYPE (from))
6097 if (TREE_CODE (to) != TREE_CODE (from))
6100 if (TREE_CODE (from) == OFFSET_TYPE
6101 && same_type_p (TYPE_OFFSET_BASETYPE (from),
6102 TYPE_OFFSET_BASETYPE (to)))
6105 if (TREE_CODE (to) != POINTER_TYPE)
6106 return same_type_ignoring_top_level_qualifiers_p (to, from);
6110 /* Returns the type qualifiers for this type, including the qualifiers on the
6111 elements for an array type. */
6114 cp_type_quals (tree type)
6116 type = strip_array_types (type);
6117 if (type == error_mark_node)
6118 return TYPE_UNQUALIFIED;
6119 return TYPE_QUALS (type);
6122 /* Returns nonzero if the TYPE contains a mutable member */
6125 cp_has_mutable_p (tree type)
6127 type = strip_array_types (type);
6129 return CLASS_TYPE_P (type) && CLASSTYPE_HAS_MUTABLE (type);
6132 /* Subroutine of casts_away_constness. Make T1 and T2 point at
6133 exemplar types such that casting T1 to T2 is casting away castness
6134 if and only if there is no implicit conversion from T1 to T2. */
6137 casts_away_constness_r (tree *t1, tree *t2)
6142 /* [expr.const.cast]
6144 For multi-level pointer to members and multi-level mixed pointers
6145 and pointers to members (conv.qual), the "member" aspect of a
6146 pointer to member level is ignored when determining if a const
6147 cv-qualifier has been cast away. */
6148 if (TYPE_PTRMEM_P (*t1))
6149 *t1 = build_pointer_type (TYPE_PTRMEM_POINTED_TO_TYPE (*t1));
6150 if (TYPE_PTRMEM_P (*t2))
6151 *t2 = build_pointer_type (TYPE_PTRMEM_POINTED_TO_TYPE (*t2));
6153 /* [expr.const.cast]
6155 For two pointer types:
6157 X1 is T1cv1,1 * ... cv1,N * where T1 is not a pointer type
6158 X2 is T2cv2,1 * ... cv2,M * where T2 is not a pointer type
6161 casting from X1 to X2 casts away constness if, for a non-pointer
6162 type T there does not exist an implicit conversion (clause
6165 Tcv1,(N-K+1) * cv1,(N-K+2) * ... cv1,N *
6169 Tcv2,(M-K+1) * cv2,(M-K+2) * ... cv2,M *. */
6171 if (TREE_CODE (*t1) != POINTER_TYPE
6172 || TREE_CODE (*t2) != POINTER_TYPE)
6174 *t1 = cp_build_qualified_type (void_type_node,
6175 cp_type_quals (*t1));
6176 *t2 = cp_build_qualified_type (void_type_node,
6177 cp_type_quals (*t2));
6181 quals1 = cp_type_quals (*t1);
6182 quals2 = cp_type_quals (*t2);
6183 *t1 = TREE_TYPE (*t1);
6184 *t2 = TREE_TYPE (*t2);
6185 casts_away_constness_r (t1, t2);
6186 *t1 = build_pointer_type (*t1);
6187 *t2 = build_pointer_type (*t2);
6188 *t1 = cp_build_qualified_type (*t1, quals1);
6189 *t2 = cp_build_qualified_type (*t2, quals2);
6192 /* Returns nonzero if casting from TYPE1 to TYPE2 casts away
6196 casts_away_constness (tree t1, tree t2)
6198 if (TREE_CODE (t2) == REFERENCE_TYPE)
6200 /* [expr.const.cast]
6202 Casting from an lvalue of type T1 to an lvalue of type T2
6203 using a reference cast casts away constness if a cast from an
6204 rvalue of type "pointer to T1" to the type "pointer to T2"
6205 casts away constness. */
6206 t1 = (TREE_CODE (t1) == REFERENCE_TYPE ? TREE_TYPE (t1) : t1);
6207 return casts_away_constness (build_pointer_type (t1),
6208 build_pointer_type (TREE_TYPE (t2)));
6211 if (TYPE_PTRMEM_P (t1) && TYPE_PTRMEM_P (t2))
6212 /* [expr.const.cast]
6214 Casting from an rvalue of type "pointer to data member of X
6215 of type T1" to the type "pointer to data member of Y of type
6216 T2" casts away constness if a cast from an rvalue of type
6217 "pointer to T1" to the type "pointer to T2" casts away
6219 return casts_away_constness
6220 (build_pointer_type (TYPE_PTRMEM_POINTED_TO_TYPE (t1)),
6221 build_pointer_type (TYPE_PTRMEM_POINTED_TO_TYPE (t2)));
6223 /* Casting away constness is only something that makes sense for
6224 pointer or reference types. */
6225 if (TREE_CODE (t1) != POINTER_TYPE
6226 || TREE_CODE (t2) != POINTER_TYPE)
6229 /* Top-level qualifiers don't matter. */
6230 t1 = TYPE_MAIN_VARIANT (t1);
6231 t2 = TYPE_MAIN_VARIANT (t2);
6232 casts_away_constness_r (&t1, &t2);
6233 if (!can_convert (t2, t1))
6239 /* If T is a REFERENCE_TYPE return the type to which T refers.
6240 Otherwise, return T itself. */
6243 non_reference (tree t)
6245 if (TREE_CODE (t) == REFERENCE_TYPE)