/* Step 2: the whole compiler inside a C binary, and what it costs to start.
 *
 * The startup number is measured around caml_startup itself, not with time(1)
 * on the process -- what a merged dev build would pay is the runtime coming up
 * and every module initialiser running, not exec and dynamic linking, which it
 * pays today anyway. */
#include <caml/callback.h>
#include <caml/alloc.h>
#include <caml/mlvalues.h>
#include <stdio.h>
#include <time.h>

#ifndef FLANSRC
#define FLANSRC "test/programs/edn.flan"
#endif

static double ms_since(struct timespec a) {
  struct timespec b;
  clock_gettime(CLOCK_MONOTONIC, &b);
  return (b.tv_sec - a.tv_sec) * 1e3 + (b.tv_nsec - a.tv_nsec) / 1e6;
}

static const value *need(const char *n) {
  const value *f = caml_named_value(n);
  if (!f) fprintf(stderr, "spike: %s not registered\n", n);
  return f;
}

int main(int argc, char **argv) {
  struct timespec t0;
  const char *src = argc > 1 ? argv[1] : FLANSRC;
  const value *f;

  clock_gettime(CLOCK_MONOTONIC, &t0);
  caml_startup(argv);
  printf("caml_startup (runtime + every module initialiser): %.3f ms\n", ms_since(t0));

  f = need("spike_footprint");
  if (f) printf("linked-module footprint: %s\n", String_val(caml_callback(*f, Val_unit)));

  f = need("spike_compile");
  if (f) {
    clock_gettime(CLOCK_MONOTONIC, &t0);
    printf("%s\n", String_val(caml_callback(*f, caml_copy_string(src))));
    printf("first in-process compile (read+parse+check+emit): %.3f ms\n", ms_since(t0));

    clock_gettime(CLOCK_MONOTONIC, &t0);
    caml_callback(*f, caml_copy_string(src));
    printf("second, warm: %.3f ms\n", ms_since(t0));
  }

  printf("spike: C main() still owns the process\n");
  return 0;
}