Fix PR c++/66786 (ICE with nested lambdas in variable template)

gcc/cp/ChangeLog:

	PR c++/66786
	* pt.c (template_class_depth): Given a lambda type, iterate
	into its LAMBDA_TYPE_EXTRA_SCOPE field instead of its
	TYPE_CONTEXT.  Given a VAR_DECL, iterate into its
	CP_DECL_CONTEXT.

gcc/testsuite/ChangeLog:

	PR c++/66786
	* g++.dg/cpp1y/var-templ48.C: New test.
	* g++.dg/cpp1y/var-templ49.C: New test.

From-SVN: r233997

gcc/cp/ChangeLog

+2016-03-05  Patrick Palka  <ppalka@gcc.gnu.org>
+
+	PR c++/66786
+	* pt.c (template_class_depth): Given a lambda type, iterate
+	into its LAMBDA_TYPE_EXTRA_SCOPE field instead of its
+	TYPE_CONTEXT.  Given a VAR_DECL, iterate into its
+	CP_DECL_CONTEXT.
+
 2016-03-04  Jason Merrill  <jason@redhat.com>
 
 	PR c++/69203

gcc/cp/pt.c

@@ -370,16 +370,20 @@ template_class_depth (tree type)
 {
   int depth;
 
-  for (depth = 0;
-       type && TREE_CODE (type) != NAMESPACE_DECL;
-       type = (TREE_CODE (type) == FUNCTION_DECL)
-	 ? CP_DECL_CONTEXT (type) : CP_TYPE_CONTEXT (type))
+  for (depth = 0; type && TREE_CODE (type) != NAMESPACE_DECL; )
     {
       tree tinfo = get_template_info (type);
 
       if (tinfo && PRIMARY_TEMPLATE_P (TI_TEMPLATE (tinfo))
 	  && uses_template_parms (INNERMOST_TEMPLATE_ARGS (TI_ARGS (tinfo))))
 	++depth;
+
+      if (VAR_OR_FUNCTION_DECL_P (type))
+	type = CP_DECL_CONTEXT (type);
+      else if (LAMBDA_TYPE_P (type))
+	type = LAMBDA_TYPE_EXTRA_SCOPE (type);
+      else
+	type = CP_TYPE_CONTEXT (type);
     }
 
   return depth;

gcc/testsuite/ChangeLog

+2016-03-05  Patrick Palka  <ppalka@gcc.gnu.org>
+
+	PR c++/66786
+	* g++.dg/cpp1y/var-templ48.C: New test.
+	* g++.dg/cpp1y/var-templ49.C: New test.
+
 2016-03-04  Eric Botcazou  <ebotcazou@adacore.com>
 
 	* g++.dg/Wno-frame-address.C: Skip on IA-64.

gcc/testsuite/g++.dg/cpp1y/var-templ48.C

+// PR c++/66786
+// { dg-do compile { target c++14 } }
+
+template <typename... T> auto list = [](T... xs) { [=](auto f) { f(xs...); }; };
+int main() { list<int>(0); }

gcc/testsuite/g++.dg/cpp1y/var-templ49.C

+// PR c++/66786
+// { dg-do compile { target c++14 } }
+
+int f (int, bool);
+
+template <typename>
+auto list = [](auto... xs) { return [=](auto f, auto... ys) { return f(xs..., ys...); }; };
+
+const int &a = list<int>(0)(f, true);