PR c/47931 - missing -Waddress warning for comparison with NULL

gcc/testsuite/ChangeLog:
	* c-c++-common/Waddress-2.c: New test.

From-SVN: r244331

gcc/testsuite/ChangeLog

+2017-01-11  Martin Sebor  <msebor@redhat.com>
+
+	PR c/47931
+	* c-c++-common/Waddress-2.c: New test.
+
 2017-01-11  Jakub Jelinek  <jakub@redhat.com>
 
 	PR c++/78341

gcc/testsuite/c-c++-common/Waddress-2.c

+/* PR c/47931 - missing -Waddress warning for comparison with NULL
+  { dg-do compile }
+  { dg-options "-Waddress" } */
+
+#define NULL ((void *) 0)
+
+int i;
+
+int f0 (void)
+{
+  return &i != 0;   /* { dg-warning "the address of .i. will never be NULL" } */
+}
+
+int f1 (void)
+{
+  return &i != (void *) 0;   /* { dg-warning "the address of .i. will never be NULL" } */
+}
+
+int f2 (void)
+{
+  return &i != NULL;   /* { dg-warning "the address of .i. will never be NULL" } */
+}
+
+int f3 (void)
+{
+  return &i != (int *) 0;
+}
+
+
+