diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index 2257112c707..da2340a6fea 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,8 @@
+Sat Oct  9 23:16:01 1999  Ken Raeburn  <raeburn@mit.edu>
+
+	* c-common.c (check_format_info): Warn if format string isn't a
+	string literal.
+
 Sat Oct  9 23:04:02 1999  Jonathan Larmour  <jlarmour@cygnus.co.uk>
 
 	* configure.in (arm*-*-*): Don't let autoconf remove brackets
diff --git a/gcc/c-common.c b/gcc/c-common.c
index afdea93853a..3e9d962bde9 100644
--- a/gcc/c-common.c
+++ b/gcc/c-common.c
@@ -1488,10 +1488,20 @@ check_format_info (info, params)
       return;
     }
   if (TREE_CODE (format_tree) != ADDR_EXPR)
-    return;
+    {
+      /* The user may get multiple warnings if the supplied argument
+	 isn't even a string pointer.  */
+      warning ("format not a string literal, argument types not checked");
+      return;
+    }
   format_tree = TREE_OPERAND (format_tree, 0);
   if (TREE_CODE (format_tree) != STRING_CST)
-    return;
+    {
+      /* The user may get multiple warnings if the supplied argument
+	 isn't even a string pointer.  */
+      warning ("format not a string literal, argument types not checked");
+      return;
+    }
   format_chars = TREE_STRING_POINTER (format_tree);
   format_length = TREE_STRING_LENGTH (format_tree);
   if (format_length <= 1)