re PR c++/42277 (decltype error in template)

	PR c++/42277
	* semantics.c (finish_decltype_type): Don't assume that op1 of a
	COMPONENT_REF is always the field.
	* g++.dg/cpp0x/decltype20.C: New.

From-SVN: r155002

gcc/cp/ChangeLog

+2009-12-04  Jason Merrill  <jason@redhat.com>
+
+	PR c++/42277
+	* semantics.c (finish_decltype_type): Defer handling of decltype
+	of a non-dependent COMPONENT_REF in a template.
+
 2009-12-04  Dodji Seketeli  <dodji@redhat.com>
 
 	PR c++/42218

gcc/cp/semantics.c

@@ -4777,7 +4777,13 @@ finish_decltype_type (tree expr, bool id_expression_or_member_access_p)
       return error_mark_node;
     }
 
-  if (type_dependent_expression_p (expr))
+  if (type_dependent_expression_p (expr)
+      /* In a template, a COMPONENT_REF has an IDENTIFIER_NODE for op1 even
+	 if it isn't dependent, so that we can check access control at
+	 instantiation time, so defer the decltype as well (PR 42277).  */
+      || (id_expression_or_member_access_p
+	  && processing_template_decl
+	  && TREE_CODE (expr) == COMPONENT_REF))
     {
       if (id_expression_or_member_access_p)
 	{

gcc/testsuite/ChangeLog

+2009-12-04  Jason Merrill  <jason@redhat.com>
+
+	PR c++/42277
+	* g++.dg/cpp0x/decltype20.C: New.
+
 2009-12-04  David Daney  <ddaney@caviumnetworks.com>
 
 	PR rtl-optimization/42164

gcc/testsuite/g++.dg/cpp0x/decltype20.C

+// PR c++/42277
+// { dg-options -std=c++0x }
+
+struct S { int s; };
+template <int N>
+void foo ()
+{
+  S s;
+  decltype (s.s) i;
+}