gcc/testsuite/gcc.dg/format/attr-6.c

   1 /* Test for format attributes: test default attributes are applied
   2    to implicit declarations.  */
   3 /* Origin: Joseph Myers <jsm28@cam.ac.uk> */
   4 /* { dg-do compile } */
   5 /* { dg-options "-std=gnu89 -Wformat" } */
   6
   7 /* We can't #include "format.h" here.  */
   8
   9 /* Technically, none of the format functions should be implicitly declared;
  10    either the implicit type is wrong, the function has variable arguments
  11    or it requires a type declared in a header.  However, some bad programming
  12    practice uses implicit declarations of some of these functions.
  13
  14    Note that printf is not used in this test because of the declaration
  15    of it as a built-in function.  */
  16
  17 void
  18 foo (const char *s, int *p)
  19 {
  20   scanf("%ld", p); /* { dg-warning "format" "implicit scanf" } */
  21 }