On 02/25/2013 06:25 PM, Jason Merrill wrote:
On 02/25/2013 06:24 PM, Jason Merrill wrote:
I think my preference would be to avoid calling fixed_type_or_null at
all when we're in a template. I already changed
resolves_to_fixed_type_p that way, now we need to fix build_vtbl_ref_1.
Oops, now I see the discussion on the PR. I'll take a look.
I'm applying this patch. When we're in fold_non_dependent_expr we care
about doing the right thing for possible constant-expressions, but a
virtual function call can't be part of a constant-expression, so we
don't need to worry about virtual lookup.
Tested x86_64-pc-linux-gnu, applying to trunk.
commit 8d561a71fbe141ad4d5b4f1ff9160e4f4c81a061
Author: Jason Merrill <ja...@redhat.com>
Date: Tue Feb 26 10:06:31 2013 -0500
PR c++/56243
* call.c (build_over_call): Avoid virtual lookup in a template.
diff --git a/gcc/cp/call.c b/gcc/cp/call.c
index 7c41421..4eb38ec 100644
--- a/gcc/cp/call.c
+++ b/gcc/cp/call.c
@@ -7033,7 +7033,10 @@ build_over_call (struct z_candidate *cand, int flags, tsubst_flags_t complain)
if (!already_used)
mark_used (fn);
- if (DECL_VINDEX (fn) && (flags & LOOKUP_NONVIRTUAL) == 0)
+ if (DECL_VINDEX (fn) && (flags & LOOKUP_NONVIRTUAL) == 0
+ /* Don't mess with virtual lookup in fold_non_dependent_expr; virtual
+ functions can't be constexpr. */
+ && !in_template_function ())
{
tree t;
tree binfo = lookup_base (TREE_TYPE (TREE_TYPE (argarray[0])),
diff --git a/gcc/testsuite/g++.dg/template/virtual4.C b/gcc/testsuite/g++.dg/template/virtual4.C
new file mode 100644
index 0000000..a2c7420b
--- /dev/null
+++ b/gcc/testsuite/g++.dg/template/virtual4.C
@@ -0,0 +1,30 @@
+// PR c++/56243
+
+struct A
+{
+ virtual int String ();
+};
+
+struct F: A { };
+
+struct G
+{
+ F value;
+};
+
+struct D
+{
+ template <int>
+ void Verify()
+ {
+ G x;
+ F& name = x.value;
+ name.String();
+ }
+};
+
+int main()
+{
+ D d;
+ d.Verify<42>();
+}
