re PR c++/60182 (g++ segfault within template expansion using "using" aliasing)

	PR c++/60182
	* pt.c (unify): Ignore alias templates when deducing a template
	template parameter.

From-SVN: r208177

gcc/cp/ChangeLog

 2014-02-26  Jason Merrill  <jason@redhat.com>
 
+	PR c++/60182
+	* pt.c (unify): Ignore alias templates when deducing a template
+	template parameter.
+
 	PR c++/60345
 	Revert:
 	DR 1571

gcc/cp/pt.c

@@ -17390,9 +17390,11 @@ unify (tree tparms, tree targs, tree parm, tree arg, int strict,
 	  if (TREE_CODE (arg) != BOUND_TEMPLATE_TEMPLATE_PARM
 	      && !CLASSTYPE_SPECIALIZATION_OF_PRIMARY_TEMPLATE_P (arg))
 	    return unify_template_deduction_failure (explain_p, parm, arg);
-
 	  {
 	    tree parmvec = TYPE_TI_ARGS (parm);
+	    /* An alias template name is never deduced.  */
+	    if (TYPE_ALIAS_P (arg))
+	      arg = strip_typedefs (arg);
 	    tree argvec = INNERMOST_TEMPLATE_ARGS (TYPE_TI_ARGS (arg));
 	    tree full_argvec = add_to_template_args (targs, argvec);
 	    tree parm_parms 

gcc/testsuite/g++.dg/cpp0x/alias-decl-41.C

+// PR c++/60182
+// { dg-require-effective-target c++11 }
+
+class B {};
+template <typename> using __allocator_base = B;
+template <typename> class F : __allocator_base<int> {};
+class C {};
+template <typename, typename = F<int> > class G : C {};
+template <typename> class D;
+class A {
+  using Container = G<D<char>>;
+  A();
+  A(D<char> const &);
+  Container m_elements;
+};
+template <template <class, class> class C, class A = F<D<int>>>
+void doSomething(C<D<char>, A> &);
+A::A(D<char> const &) : A() { doSomething(m_elements); }