PR c++/51289 - ICE with alias template for bound template template parm

gcc/cp/

	PR c++/51289
	* cp-tree.h (TYPE_TEMPLATE_INFO): Rewrite this accessor macro to
	better support aliased types.
	(TYPE_ALIAS_P): Don't crash on TYPE_NAME nodes that are not
	TYPE_DECL.
	* pt.c (find_parameter_packs_r): Handle types aliases.
	(push_template_decl_real): Check for bare parameter packs in the
	underlying type of an alias template.

gcc/PR51289/gcc/testsuite/

	PR c++/51289
	* g++.dg/cpp0x/alias-decl-17.C: New test.

From-SVN: r182170

5 files changed, 73 insertions, 11 deletions

diff --git a/gcc/cp/ChangeLog b/gcc/cp/ChangeLog
index 14e65c0..3698349 100644
--- a/gcc/cp/ChangeLog
+++ b/gcc/cp/ChangeLog
@@ -1,3 +1,14 @@
+2011-12-09  Dodji Seketeli  <dodji@redhat.com>
+
+	PR c++/51289
+	* cp-tree.h (TYPE_TEMPLATE_INFO): Rewrite this accessor macro to
+	better support aliased types.
+	(TYPE_ALIAS_P): Don't crash on TYPE_NAME nodes that are not
+	TYPE_DECL.
+	* pt.c (find_parameter_packs_r): Handle types aliases.
+	(push_template_decl_real): Check for bare parameter packs in the
+	underlying type of an alias template.
+
 2011-12-08  Jason Merrill  <jason@redhat.com>
 
 	PR c++/51318
diff --git a/gcc/cp/cp-tree.h b/gcc/cp/cp-tree.h
index 87cb8b6..955d0eb 100644
--- a/gcc/cp/cp-tree.h
+++ b/gcc/cp/cp-tree.h
@@ -2555,6 +2555,7 @@ extern void decl_shadowed_for_var_insert (tree, tree);
 #define TYPE_ALIAS_P(NODE)			\
   (TYPE_P (NODE)				\
    && TYPE_NAME (NODE)				\
+   && TREE_CODE (TYPE_NAME (NODE)) == TYPE_DECL	\
    && TYPE_DECL_ALIAS_P (TYPE_NAME (NODE)))
 
 /* For a class type: if this structure has many fields, we'll sort them
@@ -2607,17 +2608,24 @@ extern void decl_shadowed_for_var_insert (tree, tree);
   (LANG_TYPE_CLASS_CHECK (BOUND_TEMPLATE_TEMPLATE_PARM_TYPE_CHECK (NODE)) \
    ->template_info)
 
-/* Template information for an ENUMERAL_, RECORD_, or UNION_TYPE.  */
+/* Template information for an ENUMERAL_, RECORD_, UNION_TYPE, or
+   BOUND_TEMPLATE_TEMPLATE_PARM type.  Note that if NODE is a
+   specialization of an alias template, this accessor returns the
+   template info for the alias template, not the one (if any) for the
+   template of the underlying type.  */
 #define TYPE_TEMPLATE_INFO(NODE)					\
-  (TREE_CODE (NODE) == ENUMERAL_TYPE					\
-   ? ENUM_TEMPLATE_INFO (NODE) :					\
-   (TREE_CODE (NODE) == BOUND_TEMPLATE_TEMPLATE_PARM			\
-    ? TEMPLATE_TEMPLATE_PARM_TEMPLATE_INFO (NODE) :			\
-    ((CLASS_TYPE_P (NODE) && !TYPE_ALIAS_P (NODE))			\
-     ? CLASSTYPE_TEMPLATE_INFO (NODE)					\
-     : ((TYPE_NAME (NODE) && DECL_LANG_SPECIFIC (TYPE_NAME (NODE)))	\
-	? (DECL_TEMPLATE_INFO (TYPE_NAME (NODE)))			\
-	: NULL_TREE))))
+  (TYPE_ALIAS_P (NODE)							\
+   ? ((TYPE_NAME (NODE) && DECL_LANG_SPECIFIC (TYPE_NAME (NODE)))	\
+      ? DECL_TEMPLATE_INFO (TYPE_NAME (NODE))				\
+      : NULL_TREE)							\
+   : ((TREE_CODE (NODE) == ENUMERAL_TYPE)				\
+      ? ENUM_TEMPLATE_INFO (NODE)					\
+      : ((TREE_CODE (NODE) == BOUND_TEMPLATE_TEMPLATE_PARM)		\
+	 ? TEMPLATE_TEMPLATE_PARM_TEMPLATE_INFO (NODE)			\
+	 : (CLASS_TYPE_P (NODE)						\
+	    ? CLASSTYPE_TEMPLATE_INFO (NODE)				\
+	    : NULL_TREE))))
+
 
 /* Set the template information for an ENUMERAL_, RECORD_, or
    UNION_TYPE to VAL.  */
diff --git a/gcc/cp/pt.c b/gcc/cp/pt.c
index 296cd54..bb5aa0c 100644
--- a/gcc/cp/pt.c
+++ b/gcc/cp/pt.c
@@ -2976,6 +2976,20 @@ find_parameter_packs_r (tree *tp, int *walk_subtrees, void* data)
     (struct find_parameter_pack_data*)data;
   bool parameter_pack_p = false;
 
+  /* Handle type aliases/typedefs.  */
+  if (TYPE_P (t)
+      && TYPE_NAME (t)
+      && TREE_CODE (TYPE_NAME (t)) == TYPE_DECL
+      && TYPE_DECL_ALIAS_P (TYPE_NAME (t)))
+    {
+      if (TYPE_TEMPLATE_INFO (t))
+	cp_walk_tree (&TYPE_TI_ARGS (t),
+		      &find_parameter_packs_r,
+		      ppd, ppd->visited);
+      *walk_subtrees = 0;
+      return NULL_TREE;
+    }
+
   /* Identify whether this is a parameter pack or not.  */
   switch (TREE_CODE (t))
     {
@@ -4905,7 +4919,10 @@ push_template_decl_real (tree decl, bool is_friend)
       if (check_for_bare_parameter_packs (TYPE_RAISES_EXCEPTIONS (type)))
 	TYPE_RAISES_EXCEPTIONS (type) = NULL_TREE;
     }
-  else if (check_for_bare_parameter_packs (TREE_TYPE (decl)))
+  else if (check_for_bare_parameter_packs ((TREE_CODE (decl) == TYPE_DECL
+					    && TYPE_DECL_ALIAS_P (decl))
+					   ? DECL_ORIGINAL_TYPE (decl)
+					   : TREE_TYPE (decl)))
     {
       TREE_TYPE (decl) = error_mark_node;
       return error_mark_node;
diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog
index 3a97bf7..2430c7f 100644
--- a/gcc/testsuite/ChangeLog
+++ b/gcc/testsuite/ChangeLog
@@ -1,3 +1,8 @@
+2011-12-09  Dodji Seketeli  <dodji@redhat.com>
+
+	PR c++/51289
+	* g++.dg/cpp0x/alias-decl-17.C: New test.
+
 2011-12-09  Michael Meissner  <meissner@the-meissners.org>
 
 	* gcc.target/powerpc/recip-5.c: Disable running on any system that
diff --git a/gcc/testsuite/g++.dg/cpp0x/alias-decl-17.C b/gcc/testsuite/g++.dg/cpp0x/alias-decl-17.C
new file mode 100644
index 0000000..41b1c95
--- /dev/null
+++ b/gcc/testsuite/g++.dg/cpp0x/alias-decl-17.C
@@ -0,0 +1,21 @@
+// Origin PR c++/51289
+// { dg-options "-std=c++11" }
+
+template<typename a, template <typename, typename> class b>
+struct foo {
+  template <typename t>
+  using type = b<a, t>;
+  template <typename t>
+  b<a, t> funca() {}
+
+  template <typename t>
+  type<t> funcb() {}
+};
+
+// This is an additional test, to emit an error message when using
+// unexpanded parameter packs in an alias declaration.
+template <class ... T>
+struct S {};
+
+template<class ... T>
+using A = S<T>; // { dg-error "parameter packs not expanded" }