1 files changed, 22 insertions, 0 deletions
diff --git a/gcc/testsuite/gcc.dg/format/attr-6.c b/gcc/testsuite/gcc.dg/format/attr-6.c
new file mode 100644
index 000000000..0f683223d
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/format/attr-6.c
@@ -0,0 +1,22 @@
+/* Test for format attributes: test default attributes are applied
+   to implicit declarations.  */
+/* Origin: Joseph Myers <jsm28@cam.ac.uk> */
+/* { dg-do compile } */
+/* { dg-options "-std=gnu89 -Wformat" } */
+
+/* We can't #include "format.h" here.  */
+
+/* Technically, none of the format functions should be implicitly declared;
+   either the implicit type is wrong, the function has variable arguments
+   or it requires a type declared in a header.  However, some bad programming
+   practice uses implicit declarations of some of these functions.
+
+   Note that printf is not used in this test because of the declaration
+   of it as a built-in function.  */
+
+void
+foo (const char *s, int *p)
+{
+  scanf("%ld", p); /* { dg-warning "format" "implicit scanf" } */
+  /* { dg-warning "implicit" "implicit decl warning" { target *-*-* } 20 } */
+}