#include #include #include volatile int should_optimize; int __attribute__((noinline)) __fprintf_chk (FILE *f, int flag, const char *fmt, ...) { va_list ap; int ret; #ifdef __OPTIMIZE__ if (should_optimize) abort (); #endif should_optimize = 1; va_start (ap, fmt); ret = vfprintf (f, fmt, ap); va_end (ap); return ret; } int main (void) { #define test(ret, opt, args...) \ should_optimize = opt; \ __fprintf_chk (stdout, 1, args); \ if (!should_optimize) \ abort (); \ should_optimize = 0; \ if (__fprintf_chk (stdout, 1, args) != ret) \ abort (); \ if (!should_optimize) \ abort (); test (5, 1, "hello"); test (6, 1, "hello\n"); test (1, 1, "a"); test (0, 1, ""); test (5, 1, "%s", "hello"); test (6, 1, "%s", "hello\n"); test (1, 1, "%s", "a"); test (0, 1, "%s", ""); test (1, 1, "%c", 'x'); test (7, 0, "%s\n", "hello\n"); test (2, 0, "%d\n", 0); return 0; }