Commit 58fc93fb by Jason Merrill Committed by Jason Merrill

re PR c++/51406 ([c++0x] Incorrect result of static_cast to rvalue reference to base class.)

	PR c++/51406
	PR c++/51161
	* typeck.c (build_static_cast_1): Fix cast of lvalue to
	base rvalue reference.

From-SVN: r182322
parent c990877a
2011-12-13 Jason Merrill <jason@redhat.com>
PR c++/51406
PR c++/51161
* typeck.c (build_static_cast_1): Fix cast of lvalue to
base rvalue reference.
2011-12-13 Paolo Carlini <paolo.carlini@oracle.com> 2011-12-13 Paolo Carlini <paolo.carlini@oracle.com>
PR c++/51464 PR c++/51464
......
...@@ -5856,12 +5856,22 @@ build_static_cast_1 (tree type, tree expr, bool c_cast_p, ...@@ -5856,12 +5856,22 @@ build_static_cast_1 (tree type, tree expr, bool c_cast_p,
cv2 T2 if cv2 T2 is reference-compatible with cv1 T1 (8.5.3)." */ cv2 T2 if cv2 T2 is reference-compatible with cv1 T1 (8.5.3)." */
if (TREE_CODE (type) == REFERENCE_TYPE if (TREE_CODE (type) == REFERENCE_TYPE
&& TYPE_REF_IS_RVALUE (type) && TYPE_REF_IS_RVALUE (type)
&& lvalue_or_rvalue_with_address_p (expr) && real_lvalue_p (expr)
&& reference_related_p (TREE_TYPE (type), intype) && reference_related_p (TREE_TYPE (type), intype)
&& (c_cast_p || at_least_as_qualified_p (TREE_TYPE (type), intype))) && (c_cast_p || at_least_as_qualified_p (TREE_TYPE (type), intype)))
{ {
expr = build_typed_address (expr, type); /* Handle the lvalue case here by casting to lvalue reference and
return convert_from_reference (expr); then changing it to an rvalue reference. Casting an xvalue to
rvalue reference will be handled by the main code path. */
tree lref = cp_build_reference_type (TREE_TYPE (type), false);
result = (perform_direct_initialization_if_possible
(lref, expr, c_cast_p, complain));
result = cp_fold_convert (type, result);
/* Make sure we don't fold back down to a named rvalue reference,
because that would be an lvalue. */
if (DECL_P (result))
result = build1 (NON_LVALUE_EXPR, type, result);
return convert_from_reference (result);
} }
/* Resolve overloaded address here rather than once in /* Resolve overloaded address here rather than once in
......
2011-12-13 Jason Merrill <jason@redhat.com>
PR c++/51406
PR c++/51161
* g++.dg/cpp0x/rv-cast3.C: New.
* g++.dg/cpp0x/rv-cast4.C: New.
2011-12-13 Paolo Carlini <paolo.carlini@oracle.com> 2011-12-13 Paolo Carlini <paolo.carlini@oracle.com>
PR c++/51464 PR c++/51464
......
// PR c++/51406
// { dg-do run { target c++11 } }
extern "C" int printf(const char *,...);
extern "C" void abort();
struct A { int a; A() : a(1) {} };
struct B { int b; B() : b(2) {} };
struct X : A, B {};
int main() {
X x;
int a=static_cast<A&&>(x).a;
int b=static_cast<B&&>(x).b;
// printf ("%d %d\n", a, b);
if (a!=1 || b!=2) abort();
}
// PR c++/51161
// { dg-do compile { target c++11 } }
struct A{};
struct B : A{};
struct C : A{};
struct D : B, C{};
int main()
{
D d;
static_cast<A &&>(d); // { dg-error "ambiguous" }
}
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