On Fri, 14 Sep 2012, Jason Merrill wrote:
On 09/14/2012 11:03 AM, Marc Glisse wrote:
I wanted to use decltype(x<x) to find an integer vector type of the same
size as x, and then actually be able to use it. Being opaque, it refuses
to be initialized (cp/decl.c:5550). Maybe decltype (and others?) could
return non-opaque types?
That sounds like the right answer.
Hello,
does the attached make sense? It passes booststrap+testsuite, but with
vectors that doesn't prove much...
2012-09-17 Marc Glisse <marc.gli...@inria.fr>
PR c++/54581
gcc/cp/
* semantics.c (finish_decltype_type): Make vectors not opaque.
gcc/testsuite/
* g++.dg/cpp0x/decltype-54581.C: New testcase.
--
Marc GlisseIndex: cp/semantics.c
===================================================================
--- cp/semantics.c (revision 191341)
+++ cp/semantics.c (working copy)
@@ -5305,20 +5305,25 @@ finish_decltype_type (tree expr, bool id
/* If the expression is just "this", we want the
cv-unqualified pointer for the "this" type. */
type = TYPE_MAIN_VARIANT (TREE_TYPE (expr));
else
{
/* Otherwise, where T is the type of e, if e is an lvalue,
decltype(e) is defined as T&; if an xvalue, T&&; otherwise, T. */
cp_lvalue_kind clk = lvalue_kind (expr);
type = unlowered_expr_type (expr);
gcc_assert (TREE_CODE (type) != REFERENCE_TYPE);
+
+ /* For vector types, pick a non-opaque variant. */
+ if (TREE_CODE (type) == VECTOR_TYPE)
+ type = cp_build_qualified_type (TYPE_MAIN_VARIANT (type),
+ cp_type_quals (type));
if (clk != clk_none && !(clk & clk_class))
type = cp_build_reference_type (type, (clk & clk_rvalueref));
}
}
return type;
}
/* Called from trait_expr_value to evaluate either __has_nothrow_assign or
__has_nothrow_copy, depending on assign_p. */
Index: testsuite/g++.dg/cpp0x/decltype-54581.C
===================================================================
--- testsuite/g++.dg/cpp0x/decltype-54581.C (revision 0)
+++ testsuite/g++.dg/cpp0x/decltype-54581.C (revision 0)
@@ -0,0 +1,28 @@
+/* { dg-do compile } */
+/* { dg-options "-std=gnu++11 -Wall" } */
+
+typedef float v4f __attribute__((vector_size(4*sizeof(float))));
+
+template <class T> void eat (T&&) {}
+
+void test1 ()
+{
+ v4f x = {0,1,2,3};
+ typedef decltype (x < x) v4i;
+ v4i y = {4,5,6,7}; // v4i is not opaque
+ eat (y);
+}
+
+template<class V>
+void test2 ()
+{
+ V x = {0,1,2,3};
+ typedef decltype (x < x) v4i;
+ v4i y = {4,5,6,7}; // v4i is not opaque
+ eat (y);
+}
+
+int main(){
+ test1();
+ test2<v4f>();
+}
Property changes on: testsuite/g++.dg/cpp0x/decltype-54581.C
___________________________________________________________________
Added: svn:eol-style
+ native
Added: svn:keywords
+ Author Date Id Revision URL
