re PR c++/51554 (ICE in cp/semantics.c:cxx_eval_indirect_ref with -Wall)

	PR c++/51554
	* semantics.c (cxx_eval_indirect_ref): Fix sanity check.

From-SVN: r182346

gcc/cp/ChangeLog

 2011-12-14  Jason Merrill  <jason@redhat.com>
 
+	PR c++/51554
+	* semantics.c (cxx_eval_indirect_ref): Fix sanity check.
+
 	PR c++/51248
 	* decl.c (copy_type_enum): Also update variants.
 	(finish_enum): Allow variants of complete enums.

gcc/cp/semantics.c

@@ -7329,9 +7329,15 @@ cxx_eval_indirect_ref (const constexpr_call *call, tree t,
     {
       tree sub = op0;
       STRIP_NOPS (sub);
-      if (TREE_CODE (sub) == ADDR_EXPR
-	  || TREE_CODE (sub) == POINTER_PLUS_EXPR)
+      if (TREE_CODE (sub) == POINTER_PLUS_EXPR)
 	{
+	  sub = TREE_OPERAND (sub, 0);
+	  STRIP_NOPS (sub);
+	}
+      if (TREE_CODE (sub) == ADDR_EXPR)
+	{
+	  /* We couldn't fold to a constant value.  Make sure it's not
+	     something we should have been able to fold.  */
 	  gcc_assert (!same_type_ignoring_top_level_qualifiers_p
 		      (TREE_TYPE (TREE_TYPE (sub)), TREE_TYPE (t)));
 	  /* DR 1188 says we don't have to deal with this.  */

gcc/testsuite/ChangeLog

 2011-12-14  Jason Merrill  <jason@redhat.com>
 
+	PR c++/51554
+	* g++.dg/init/constant1.C: New.
+
 	PR c++/51248
 	* g++.dg/other/enum2.C: New.
 

gcc/testsuite/g++.dg/init/constant1.C

+// PR c++/51554
+
+typedef unsigned char uint8;
+typedef unsigned int uint32;
+
+const uint32 XX[] = { 1, 3, 7 };
+
+const uint8 V[] = {
+  *(((const uint8*)&XX[0]) + 0),
+  *(((const uint8*)&XX[0]) + 1),
+  *(((const uint8*)&XX[0]) + 2),
+  *(((const uint8*)&XX[0]) + 3),
+  *(((const uint8*)&XX[1]) + 0),
+  *(((const uint8*)&XX[1]) + 1),
+  *(((const uint8*)&XX[1]) + 2),
+  *(((const uint8*)&XX[1]) + 3),
+};