1 files changed, 28 insertions, 0 deletions
diff --git a/gcc/testsuite/gcc.dg/format/attr-5.c b/gcc/testsuite/gcc.dg/format/attr-5.c
new file mode 100644
index 000000000..36b119896
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/format/attr-5.c
@@ -0,0 +1,28 @@
+/* Test for format attributes: test default attributes are silently ignored
+   when a function is redeclared in an inappropriate manner.  */
+/* Origin: Joseph Myers <jsm28@cam.ac.uk> */
+/* { dg-do compile } */
+/* { dg-options "-std=gnu99 -Wformat" } */
+
+/* We can't #include "format.h" here.  */
+
+/* This scanf declaration is static, so can't be the system function.  */
+static int scanf(const char *restrict, ...);
+
+/* This sscanf declaration doesn't have variable arguments, so isn't
+   compatible with a format attribute.  */
+extern int sscanf(const char *restrict, const char *restrict, int *); /* { dg-warning "conflict" "conflict" } */
+
+void
+foo (const char *s, int *p)
+{
+  scanf("%ld", p); /* { dg-bogus "format" "static" } */
+  sscanf(s, "%ld", p); /* { dg-bogus "format" "wrong type" } */
+}
+
+/* Dummy definition of scanf.  */
+static int
+scanf (const char *restrict fmt, ...)
+{
+  return 0;
+}