#include <setjmp.h>

// Note that `sigsetjmp` and `siglongjmp` are used here where possible to
// explicitly pass a 0 argument to `sigsetjmp` that we don't need to preserve
// the process signal mask. This should make this call a bit faster b/c it
// doesn't need to touch the kernel signal handling routines.
#ifdef CFG_TARGET_OS_windows
#define platform_setjmp(buf) setjmp(buf)
#define platform_longjmp(buf, arg) longjmp(buf, arg)
#define platform_jmp_buf jmp_buf
#else
#define platform_setjmp(buf) sigsetjmp(buf, 0)
#define platform_longjmp(buf, arg) siglongjmp(buf, arg)
#define platform_jmp_buf sigjmp_buf
#endif

int RegisterSetjmp(
    void **buf_storage,
    void (*body)(void*, void*),
    void *payload,
    void *callee) {
  platform_jmp_buf buf;
  if (platform_setjmp(buf) != 0) {
    return 0;
  }
  *buf_storage = &buf;
  body(payload, callee);
  return 1;
}

void Unwind(void *JmpBuf) {
  platform_jmp_buf *buf = (platform_jmp_buf*) JmpBuf;
  platform_longjmp(*buf, 1);
}