Usually we handle DR1558 substitution near the top of tsubst, but in this
case while substituting TYPENAME_TYPE we were passing an alias
specialization to tsubst_aggr_type, which ignored its aliasness.
Tested x86_64-pc-linux-gnu, applying to trunk.
PR c++/103057
gcc/cp/ChangeLog:
* pt.cc (tsubst_aggr_type): Call tsubst for alias template
specialization.
gcc/testsuite/ChangeLog:
* g++.dg/cpp0x/alias-decl-void1.C: New test.
---
gcc/cp/pt.cc | 8 ++++++++
gcc/testsuite/g++.dg/cpp0x/alias-decl-void1.C | 18 ++++++++++++++++++
2 files changed, 26 insertions(+)
create mode 100644 gcc/testsuite/g++.dg/cpp0x/alias-decl-void1.C
diff --git a/gcc/cp/pt.cc b/gcc/cp/pt.cc
index 8f50b9c4d3c..6fbda676527 100644
--- a/gcc/cp/pt.cc
+++ b/gcc/cp/pt.cc
@@ -13585,6 +13585,14 @@ tsubst_aggr_type (tree t,
if (t == NULL_TREE)
return NULL_TREE;
+ /* If T is an alias template specialization, we want to substitute that
+ rather than strip it, especially if it's dependent_alias_template_spec_p.
+ It should be OK not to handle entering_scope in this case, since
+ DECL_CONTEXT will never be an alias template specialization. We only get
+ here with an alias when tsubst calls us for TYPENAME_TYPE. */
+ if (alias_template_specialization_p (t, nt_transparent))
+ return tsubst (t, args, complain, in_decl);
+
switch (TREE_CODE (t))
{
case RECORD_TYPE:
diff --git a/gcc/testsuite/g++.dg/cpp0x/alias-decl-void1.C
b/gcc/testsuite/g++.dg/cpp0x/alias-decl-void1.C
new file mode 100644
index 00000000000..accc1a45abc
--- /dev/null
+++ b/gcc/testsuite/g++.dg/cpp0x/alias-decl-void1.C
@@ -0,0 +1,18 @@
+// PR c++/103057
+// { dg-do compile { target c++11 } }
+
+template <class T> struct A { };
+template <class T> struct B { using type = A<T>; };
+template <class T> struct C {
+ using type = typename T::foo; // { dg-error "int" }
+};
+template <class T> using L = B<void>;
+
+template <class T>
+typename L<typename C<T>::type>::type
+f(T) { };
+
+int main()
+{
+ f(42); // { dg-error "no match" }
+}
base-commit: fe5cee6f62a0b229d9d51616b7490331d39b5ddd
prerequisite-patch-id: c7ab4056fcbd782232c8dc091597602ecd4a7a48
--
2.27.0
