compiler-rt/test/fuzzer/SwitchTest.cpp

   1 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
   2 // See https://llvm.org/LICENSE.txt for license information.
   3 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
   4
   5 // Simple test for a fuzzer. The fuzzer must find the interesting switch value.
   6 #include <cstddef>
   7 #include <cstdint>
   8 #include <cstdio>
   9 #include <cstdlib>
  10 #include <cstring>
  11
  12 static volatile int Sink;
  13
  14 template<class T>
  15 bool Switch(const uint8_t *Data, size_t Size) {
  16   T X;
  17   if (Size < sizeof(X)) return false;
  18   memcpy(&X, Data, sizeof(X));
  19   switch (X) {
  20     case 1: Sink = __LINE__; break;
  21     case 101: Sink = __LINE__; break;
  22     case 1001: Sink = __LINE__; break;
  23     case 10001: Sink = __LINE__; break;
  24     case 100001: Sink = __LINE__; break;
  25     case 1000001: Sink = __LINE__; break;
  26     case 10000001: Sink = __LINE__; break;
  27     case 100000001: return true;
  28   }
  29   return false;
  30 }
  31
  32 bool ShortSwitch(const uint8_t *Data, size_t Size) {
  33   short X;
  34   if (Size < sizeof(short)) return false;
  35   memcpy(&X, Data, sizeof(short));
  36   switch(X) {
  37     case 42: Sink = __LINE__; break;
  38     case 402: Sink = __LINE__; break;
  39     case 4002: Sink = __LINE__; break;
  40     case 5002: Sink = __LINE__; break;
  41     case 7002: Sink = __LINE__; break;
  42     case 9002: Sink = __LINE__; break;
  43     case 14002: Sink = __LINE__; break;
  44     case 21402: return true;
  45   }
  46   return false;
  47 }
  48
  49 extern "C" int LLVMFuzzerTestOneInput(const uint8_t *Data, size_t Size) {
  50   if (Size >= 4  && Switch<int>(Data, Size) &&
  51       Size >= 12 && Switch<uint64_t>(Data + 4, Size - 4) &&
  52       Size >= 14 && ShortSwitch(Data + 12, 2)
  53     ) {
  54     fprintf(stderr, "BINGO; Found the target, exiting\n");
  55     exit(1);
  56   }
  57   return 0;
  58 }
  59