re PR c++/48289 (-pedantic breaks std::move)

PR c++/48289
	* pt.c (build_non_dependent_expr): Keep dereferences outside the
	NON_DEPENDENT_EXPR.

From-SVN: r171461

gcc/cp/ChangeLog

@@ -1,3 +1,9 @@
+2011-03-25  Jason Merrill  <jason@redhat.com>
+
+	PR c++/48289
+	* pt.c (build_non_dependent_expr): Keep dereferences outside the
+	NON_DEPENDENT_EXPR.
+
 2011-03-25  Kai Tietz  <ktietz@redhat.com>
 
 	* decl.c (decls_match): Replace target hook

gcc/cp/pt.c

@@ -18846,24 +18846,17 @@ build_non_dependent_expr (tree expr)
 		   TREE_OPERAND (expr, 0),
 		   build_non_dependent_expr (TREE_OPERAND (expr, 1)));
 
+  /* Keep dereferences outside the NON_DEPENDENT_EXPR so lvalue_kind
+     doesn't need to look inside.  */
+  if (TREE_CODE (expr) == INDIRECT_REF && REFERENCE_REF_P (expr))
+    return convert_from_reference (build_non_dependent_expr
+				   (TREE_OPERAND (expr, 0)));
+
   /* If the type is unknown, it can't really be non-dependent */
   gcc_assert (TREE_TYPE (expr) != unknown_type_node);
 
-  /* Otherwise, build a NON_DEPENDENT_EXPR.
-
-     REFERENCE_TYPEs are not stripped for expressions in templates
-     because doing so would play havoc with mangling.  Consider, for
-     example:
-
-       template <typename T> void f<T& g>() { g(); }
-
-     In the body of "f", the expression for "g" will have
-     REFERENCE_TYPE, even though the standard says that it should
-     not.  The reason is that we must preserve the syntactic form of
-     the expression so that mangling (say) "f<g>" inside the body of
-     "f" works out correctly.  Therefore, the REFERENCE_TYPE is
-     stripped here.  */
-  return build1 (NON_DEPENDENT_EXPR, non_reference (TREE_TYPE (expr)), expr);
+  /* Otherwise, build a NON_DEPENDENT_EXPR.  */
+  return build1 (NON_DEPENDENT_EXPR, TREE_TYPE (expr), expr);
 }
 
 /* ARGS is a vector of expressions as arguments to a function call.

gcc/testsuite/ChangeLog

@@ -1,3 +1,7 @@
+2011-03-25  Jason Merrill  <jason@redhat.com>
+
+	* g++.dg/cpp0x/move1.C: New.
+
 2011-03-25  Ira Rosen  <ira.rosen@linaro.org>
 
 	PR target/48287

gcc/testsuite/g++.dg/cpp0x/move1.C

@@ -0,0 +1,15 @@
+// { dg-options "-std=c++0x -pedantic-errors" }
+
+#include <utility>
+
+class A { };
+
+static void g ( A && ) { }
+
+template < class T > class B {
+public:
+ void f ( ) {
+  A a;
+  g ( std :: move ( a ) );
+ }
+};