1 // This file is distributed under the University of Illinois Open Source
2 // License. See LICENSE.TXT for details.
3 
4 // Find ABCxxFxUxZxxx... (2048+ bytes, 'x' is any byte)
5 #include <assert.h>
6 #include <cstddef>
7 #include <cstdint>
8 #include <cstdlib>
9 #include <cstring>
10 #include <cstdio>
11 
12 const size_t N = 2048;
13 typedef const uint8_t *IN;
14 
15 static volatile int one = 1;
16 
17 extern "C" {
18 __attribute__((noinline)) void bad() {
19   fprintf(stderr, "BINGO\n");
20   if (one)
21     abort();
22 }
23 
24 __attribute__((noinline)) void f0(IN in) {
25   uint32_t x = in[5] + 251 * in[7] + 251 * 251 * in[9];
26   if (x == 'F' + 251 * 'U' + 251 * 251 * 'Z')
27     bad();
28 }
29 
30 __attribute__((noinline)) void fC(IN in) { if (in[2] == 'C') f0(in); }
31 __attribute__((noinline)) void fB(IN in) { if (in[1] == 'B') fC(in); }
32 __attribute__((noinline)) void fA(IN in) { if (in[0] == 'A') fB(in); }
33 
34 } // extern "C"
35 
36 extern "C" int LLVMFuzzerTestOneInput(const uint8_t *Data, size_t Size) {
37   if (Size < N) return 0;
38   fA((IN)Data);
39   return 0;
40 }
41