re PR c++/47687 ([C++0x] Crash on a lambda returning a lambda (using std::function))

	PR c++/47687
	* pt.c (dependent_type_p_r): Avoid infinite recursion.

From-SVN: r174354

gcc/cp/ChangeLog

 2011-05-27  Jason Merrill  <jason@redhat.com>
 
+	PR c++/47687
+	* pt.c (dependent_type_p_r): Avoid infinite recursion.
+
 	PR c++/48284
 	* error.c (dump_expr) [COMPONENT_REF]: Use pp_cxx_dot
 	with INDIRECT_REF of REFERENCE_TYPE.

gcc/cp/pt.c

@@ -18260,8 +18260,15 @@ dependent_type_p_r (tree type)
   scope = TYPE_CONTEXT (type);
   if (scope && TYPE_P (scope))
     return dependent_type_p (scope);
-  else if (scope && TREE_CODE (scope) == FUNCTION_DECL)
-    return type_dependent_expression_p (scope);
+  /* Don't use type_dependent_expression_p here, as it can lead
+     to infinite recursion trying to determine whether a lambda
+     nested in a lambda is dependent (c++/47687).  */
+  else if (scope && TREE_CODE (scope) == FUNCTION_DECL
+	   && DECL_LANG_SPECIFIC (scope)
+	   && DECL_TEMPLATE_INFO (scope)
+	   && (any_dependent_template_arguments_p
+	       (INNERMOST_TEMPLATE_ARGS (DECL_TI_ARGS (scope)))))
+    return true;
 
   /* Other types are non-dependent.  */
   return false;

gcc/testsuite/ChangeLog

 2011-05-27  Jason Merrill  <jason@redhat.com>
 
+	* g++.dg/cpp0x/lambda/lambda-nested4.C: New.
+
 	* g++.dg/cpp0x/error6.C: New.
 
 	* g++.dg/cpp0x/error5.C: New.

gcc/testsuite/g++.dg/cpp0x/lambda/lambda-nested4.C

+// PR c++/47687
+// { dg-options -std=c++0x }
+
+template <class T> struct A { };
+
+auto inl = []{ return []{}; }();
+typedef decltype(inl) inlt;
+
+A<inlt> a;