Sadly my attempt to make some aliast template construction immutable
doesn't always apply. Reverting that patch and I guess more work needed
on modules :(
nathan
--
Nathan Sidwell
2020-05-27 Nathan Sidwell <nat...@acm.org>
PR c++/95263, revert 74744bb1f2847b5b9ce3e97e0fec9c23bb0e499f
* pt.c (lookup_template_class_1): Restore alias template mutation.
diff --git i/gcc/cp/pt.c w/gcc/cp/pt.c
index c17a038c6d0..4d9651acee6 100644
--- i/gcc/cp/pt.c
+++ w/gcc/cp/pt.c
@@ -10062,21 +10062,8 @@ lookup_template_class_1 (tree d1, tree arglist, tree in_decl, tree context,
}
}
- /* Build template info for the new specialization. This can
- overwrite the existing TEMPLATE_INFO for T (that points to
- its instantiated TEMPLATE_DECL), with this one that points to
- the most general template, but that's what we want. */
-
- if (TYPE_ALIAS_P (t))
- {
- /* This should already have been constructed during
- instantiation of the alias decl. */
- tree ti = DECL_TEMPLATE_INFO (TYPE_NAME (t));
- gcc_checking_assert (template_args_equal (TI_ARGS (ti), arglist)
- && TI_TEMPLATE (ti) == found);
- }
- else
- SET_TYPE_TEMPLATE_INFO (t, build_template_info (found, arglist));
+ // Build template info for the new specialization.
+ SET_TYPE_TEMPLATE_INFO (t, build_template_info (found, arglist));
elt.spec = t;
slot = type_specializations->find_slot_with_hash (&elt, hash, INSERT);
diff --git c/gcc/testsuite/g++.dg/template/pr95263.C w/gcc/testsuite/g++.dg/template/pr95263.C
new file mode 100644
index 00000000000..08a1b8730c0
--- /dev/null
+++ w/gcc/testsuite/g++.dg/template/pr95263.C
@@ -0,0 +1,23 @@
+// { dg-do compile { target c++11 } }
+// PR C++/95263
+// ICE on alias template instantiation
+
+template <typename> class TPL {
+ template <int> using INT = int;
+};
+
+template <typename T> class Klass
+{
+public:
+ template <int I> using ALIAS = typename TPL<T>::INT<I>;
+
+ template <int> static void FUNC (); // OK
+
+ template <int I, typename> static ALIAS<I> FUNC (); // SFINAE ICE
+};
+
+void Fn ()
+{
+ Klass<int>::FUNC<0> ();
+}
+
