--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/gcc/testsuite/gcc.dg/uninit-A-O0.c	Fri Oct 27 22:46:09 2017 +0900
@@ -0,0 +1,117 @@
+/* Inspired by part of java/parse.y.
+   May be a real bug in CSE. */
+
+/* { dg-do compile } */
+/* { dg-options "-Wall" } */
+
+struct tree
+{
+    struct tree *car, *cdr, *wfl;
+    int code;
+    struct { unsigned int renp:1;
+      unsigned int rtnp:1;
+      unsigned int rpnp:1; } flags;
+};
+typedef struct tree *tree;
+#define NULL_TREE ((tree)0)
+
+/* Codes */
+enum
+{
+    CALL_EXPR, NEW_ARRAY_EXPR, NEW_CLASS_EXPR, CONVERT_EXPR,
+    ARRAY_REF, CONDITIONAL_EXPR, STRING_CST, EXPR_WITH_FILE_LOCATION
+};
+
+/* Flags */
+#define RESOLVE_EXPRESSION_NAME_P(t) ((t)->flags.renp)
+#define RESOLVE_TYPE_NAME_P(t) ((t)->flags.rtnp)
+#define RESOLVE_PACKAGE_NAME_P(t) ((t)->flags.rpnp)
+
+/* Macros */
+#define EXPR_WFL_QUALIFICATION(t) ((t)->wfl)
+#define QUAL_WFL(t) ((t)->wfl)
+#define EXPR_WFL_NODE(t) ((t)->wfl)
+#define TREE_CODE(t) ((t)->code)
+#define TREE_OPERAND(t,x) ((t)->car)
+#define CLASSTYPE_SUPER(t) ((t)->car)
+#define IDENTIFIER_LOCAL_VALUE(t) ((t)->car)
+#define TREE_CHAIN(t) ((t)->cdr)
+#define QUAL_RESOLUTION(t) ((t)->cdr)
+
+extern tree current_class, this_identifier_node;
+extern tree super_identifier_node, length_identifier_node;
+
+tree resolve_and_layout (tree, tree);
+tree lookup_field_wrapper (tree, tree);
+
+void
+qualify_ambiguous_name (id)
+     tree id;
+{
+  tree qual, qual_wfl, decl;
+  tree name;	 /* { dg-bogus "name" "uninitialized variable warning" } */
+  tree ptr_type; /* { dg-bogus "ptr_type" "uninitialized variable warning" } */
+  int again, new_array_found = 0;
+  int super_found = 0, this_found = 0;
+
+  qual = EXPR_WFL_QUALIFICATION (id);
+  do {
+    qual_wfl = QUAL_WFL (qual);
+    switch (TREE_CODE (qual_wfl))
+      {
+      case CALL_EXPR:
+	qual_wfl = TREE_OPERAND (qual_wfl, 0);
+	if (TREE_CODE (qual_wfl) != EXPR_WITH_FILE_LOCATION)
+	  {
+	    qual = EXPR_WFL_QUALIFICATION (qual_wfl);
+	    qual_wfl = QUAL_WFL (qual);
+	  }
+	break;
+      case NEW_ARRAY_EXPR:
+	qual = TREE_CHAIN (qual);
+	new_array_found = again = 1;
+	continue;
+      case NEW_CLASS_EXPR:
+      case CONVERT_EXPR:
+	qual_wfl = TREE_OPERAND (qual_wfl, 0);
+	break;
+      case ARRAY_REF:
+	while (TREE_CODE (qual_wfl) == ARRAY_REF)
+	  qual_wfl = TREE_OPERAND (qual_wfl, 0);
+	break;
+      default:
+	break;
+      }
+
+    name = EXPR_WFL_NODE (qual_wfl);
+    ptr_type = current_class;
+    again = 0;
+
+  } while (again);
+
+  /* If you put straightforward uses of name and ptr_type here
+     instead of the if-else sequence below, the warnings go away.
+     Therefore I suspect a real bug. */
+  
+  if (!this_found && !super_found && (decl = IDENTIFIER_LOCAL_VALUE (name)))
+    {
+      RESOLVE_EXPRESSION_NAME_P (qual_wfl) = 1;
+      QUAL_RESOLUTION (qual) = decl;
+    }
+  else if ((decl = lookup_field_wrapper (ptr_type, name))
+	   || (new_array_found && name == length_identifier_node))
+    {
+      RESOLVE_EXPRESSION_NAME_P (qual_wfl) = 1;
+      QUAL_RESOLUTION (qual) = (new_array_found ? NULL_TREE : decl);
+    }
+  else if ((decl = resolve_and_layout (name, NULL_TREE)))
+    {
+      RESOLVE_TYPE_NAME_P (qual_wfl) = 1;
+      QUAL_RESOLUTION (qual) = decl;
+    }
+  else if (TREE_CODE (QUAL_WFL (qual)) == CALL_EXPR
+	   || TREE_CODE (QUAL_WFL (qual)) == ARRAY_REF)
+    RESOLVE_EXPRESSION_NAME_P (qual_wfl) = 1;
+  else 
+    RESOLVE_PACKAGE_NAME_P (qual_wfl) = 1;
+}