--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/gcc/testsuite/gcc.dg/Walways-true-1.c	Fri Oct 27 22:46:09 2017 +0900
@@ -0,0 +1,57 @@
+/* Test -Waddress for testing an address against NULL.
+   Origin: Ian Lance Taylor <iant@google.com>.  */
+
+/* { dg-do compile } */
+/* { dg-options "-Waddress -fshow-column" } */
+
+extern int foo (int);
+
+int i;
+
+void
+bar (int a)
+{
+ lab:
+  if (foo)	/* { dg-warning "7:always evaluate as" "correct warning" } */
+    foo (0);
+  if (foo (1))
+    ;
+  if (&i)	/* { dg-warning "7:always evaluate as" "correct warning" } */
+    foo (2);
+  if (i)
+    foo (3);
+  if (&a)	/* { dg-warning "7:always evaluate as" "correct warning" } */
+    foo (4);
+  if (a)
+    foo (5);
+  if (&&lab)	/* { dg-warning "7:always evaluate as" "correct warning" } */
+    foo (6);
+  if (foo == 0)	/* { dg-warning "11:the comparison will always evaluate as 'false'" "correct warning" } */
+    foo (7);
+  if (foo (1) == 0)
+    foo (8);
+  if (&i == 0)	/* { dg-warning "10:the comparison will always evaluate as 'false'" "correct warning" } */
+    foo (9);
+  if (i == 0)
+    foo (10);
+  if (&a == 0)	/* { dg-warning "10:the comparison will always evaluate as 'false'" "correct warning" } */
+    foo (11);
+  if (a == 0)
+    foo (12);
+  if (&&lab == 0) /* { dg-warning "13:the comparison will always evaluate as 'false'" "correct warning" } */
+    foo (13);
+  if (0 == foo)	/* { dg-warning "9:the comparison will always evaluate as 'false'" "correct warning" } */
+    foo (14);
+  if (0 == foo (1))
+    foo (15);
+  if (0 == &i)	/* { dg-warning "9:the comparison will always evaluate as 'false'" "correct warning" } */
+    foo (16);
+  if (0 == i)
+    foo (17);
+  if (0 == &a)	/* { dg-warning "9:the comparison will always evaluate as 'false'" "correct warning" } */
+    foo (18);
+  if (0 == a)
+    foo (19);
+  if (0 == &&lab) /* { dg-warning "9:the comparison will always evaluate as 'false'" "correct warning" } */
+    foo (20);
+}