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ffi/target/release/build/mlua-sys-6a99a2ae50f12319/out/luajit-build/build/src/lj_err.c  view on Meta::CPAN

/* -- Internal frame unwinding -------------------------------------------- */

/* Unwind Lua stack and move error message to new top. */
LJ_NOINLINE static void unwindstack(lua_State *L, TValue *top)
{
  lj_func_closeuv(L, top);
  if (top < L->top-1) {
    copyTV(L, top, L->top-1);
    L->top = top+1;
  }
  lj_state_relimitstack(L);
}

/* Unwind until stop frame. Optionally cleanup frames. */
static void *err_unwind(lua_State *L, void *stopcf, int errcode)
{
  TValue *frame = L->base-1;
  void *cf = L->cframe;
  while (cf) {
    int32_t nres = cframe_nres(cframe_raw(cf));
    if (nres < 0) {  /* C frame without Lua frame? */
      TValue *top = restorestack(L, -nres);
      if (frame < top) {  /* Frame reached? */
	if (errcode) {
	  L->base = frame+1;
	  L->cframe = cframe_prev(cf);
	  unwindstack(L, top);
	}
	return cf;
      }
    }
    if (frame <= tvref(L->stack)+LJ_FR2)
      break;
    switch (frame_typep(frame)) {
    case FRAME_LUA:  /* Lua frame. */
    case FRAME_LUAP:
      frame = frame_prevl(frame);
      break;
    case FRAME_C:  /* C frame. */
    unwind_c:
#if LJ_UNWIND_EXT
      if (errcode) {
	L->base = frame_prevd(frame) + 1;
	L->cframe = cframe_prev(cf);
	unwindstack(L, frame - LJ_FR2);
      } else if (cf != stopcf) {
	cf = cframe_prev(cf);
	frame = frame_prevd(frame);
	break;
      }
      return NULL;  /* Continue unwinding. */
#else
      UNUSED(stopcf);
      cf = cframe_prev(cf);
      frame = frame_prevd(frame);
      break;
#endif
    case FRAME_CP:  /* Protected C frame. */
      if (cframe_canyield(cf)) {  /* Resume? */
	if (errcode) {
	  hook_leave(G(L));  /* Assumes nobody uses coroutines inside hooks. */
	  L->cframe = NULL;
	  L->status = (uint8_t)errcode;
	}
	return cf;
      }
      if (errcode) {
	L->base = frame_prevd(frame) + 1;
	L->cframe = cframe_prev(cf);
	unwindstack(L, frame - LJ_FR2);
      }
      return cf;
    case FRAME_CONT:  /* Continuation frame. */
      if (frame_iscont_fficb(frame))
	goto unwind_c;
      /* fallthrough */
    case FRAME_VARG:  /* Vararg frame. */
      frame = frame_prevd(frame);
      break;
    case FRAME_PCALL:  /* FF pcall() frame. */
    case FRAME_PCALLH:  /* FF pcall() frame inside hook. */
      if (errcode) {
	global_State *g;
	if (errcode == LUA_YIELD) {
	  frame = frame_prevd(frame);
	  break;
	}
	g = G(L);
	setgcref(g->cur_L, obj2gco(L));
	if (frame_typep(frame) == FRAME_PCALL)
	  hook_leave(g);
	L->base = frame_prevd(frame) + 1;
	L->cframe = cf;
	unwindstack(L, L->base);
      }
      return (void *)((intptr_t)cf | CFRAME_UNWIND_FF);
    }
  }
  /* No C frame. */
  if (errcode) {
    L->base = tvref(L->stack)+1+LJ_FR2;
    L->cframe = NULL;
    unwindstack(L, L->base);
    if (G(L)->panic)
      G(L)->panic(L);
    exit(EXIT_FAILURE);
  }
  return L;  /* Anything non-NULL will do. */
}

/* -- External frame unwinding -------------------------------------------- */

#if LJ_ABI_WIN

/*
** Someone in Redmond owes me several days of my life. A lot of this is
** undocumented or just plain wrong on MSDN. Some of it can be gathered
** from 3rd party docs or must be found by trial-and-error. They really
** don't want you to write your own language-specific exception handler
** or to interact gracefully with MSVC. :-(
*/