Function LLVMFuzzerTestOneInput

Tests/Fuzzing/cmScriptFuzzer.cxx:91–147

}

extern "C" int LLVMFuzzerTestOneInput(uint8_t const* data, size_t size)
{
  if (size == 0 || size > kMaxInputSize) {
    return 0;
  }

#ifdef __linux__
  if (g_useMemfd) {
    // Extract fd from path and write directly
    int fd = std::atoi(g_scriptFile.c_str() + 14); // "/proc/self/fd/"
    ftruncate(fd, 0);
    lseek(fd, 0, SEEK_SET);
    if (write(fd, data, size) != static_cast<ssize_t>(size)) {
      return 0;
    }
  } else
#endif
  {
    // Write script to temp file
    FILE* fp = fopen(g_scriptFile.c_str(), "wb");
    if (!fp)
      return 0;
    fwrite(data, 1, size, fp);
    fclose(fp);
  }

  // Save CWD in case script uses file(CHDIR)
  std::string cwd = cmSystemTools::GetCurrentWorkingDirectory();

  // Create cmake instance for script mode
  cmake cm(cmState::Role::Script);
  cm.SetHomeDirectory(g_testDir);
  cm.SetHomeOutputDirectory(g_testDir);

  // Run the script
  std::vector<std::string> args;
  args.push_back("cmake");
  args.push_back("-P");
  args.push_back(g_scriptFile);

  (void)cm.Run(args, false);

  // Restore CWD before cleanup (script may have changed it via file(CHDIR))
  cmSystemTools::ChangeDirectory(cwd);

  // Cleanup temp file (memfd doesn't need cleanup)
  if (!g_useMemfd) {
    unlink(g_scriptFile.c_str());
  }

  // Clean up any files the script may have created in g_testDir
  // This prevents disk growth and non-determinism from previous iterations
  cmSystemTools::RemoveADirectory(g_testDir);
  cmSystemTools::MakeDirectory(g_testDir);

  return 0;
}