CHECK_C_SOURCE_COMPILES("
int main()
{
  __builtin_unreachable();
  return 0;
}" HAVE_BUILTIN_UNREACHABLE)

CHECK_C_SOURCE_COMPILES("
int main()
{
  __builtin_unreachable();
  return 0;
}" HAVE_BUILTIN_UNREACHABLE)

CHECK_C_SOURCE_COMPILES("
int main()
{
  __builtin_unreachable();
  return 0;
}" HAVE_BUILTIN_UNREACHABLE)

CHECK_C_SOURCE_COMPILES("
int main()
{
  __builtin_unreachable();
  return 0;
}" HAVE_BUILTIN_UNREACHABLE)

CHECK_C_SOURCE_COMPILES("
int main()
{
  __builtin_unreachable();
  return 0;
}" HAVE_BUILTIN_UNREACHABLE)

check_c_source_compiles(
  "int main(int c, char *v[]) { if (c) __builtin_unreachable(); return (int)(*v[0]); }"
  HAVE_BUILTIN_UNREACHABLE
)

CHECK_C_SOURCE_COMPILES("
int main()
{
  __builtin_unreachable();
  return 0;
}" HAVE_BUILTIN_UNREACHABLE)

CHECK_C_SOURCE_COMPILES("
int main()
{
  __builtin_unreachable();
  return 0;
}" HAVE_BUILTIN_UNREACHABLE)

CHECK_C_SOURCE_COMPILES("
int main()
{
  __builtin_unreachable();
  return 0;
}" HAVE_BUILTIN_UNREACHABLE)

CHECK_C_SOURCE_COMPILES("
int main()
{
  __builtin_unreachable();
  return 0;
}" HAVE_BUILTIN_UNREACHABLE)