1/*
2** VM event handling.
3** Copyright (C) 2005-2021 Mike Pall. See Copyright Notice in luajit.h
4*/
5
6#include <stdio.h>
7
8#define lj_vmevent_c
9#define LUA_CORE
10
11#include "lj_obj.h"
12#include "lj_str.h"
13#include "lj_tab.h"
14#include "lj_state.h"
15#include "lj_dispatch.h"
16#include "lj_vm.h"
17#include "lj_vmevent.h"
18
19ptrdiff_t lj_vmevent_prepare(lua_State *L, VMEvent ev)
20{
21 global_State *g = G(L);
22 GCstr *s = lj_str_newlit(L, LJ_VMEVENTS_REGKEY);
23 cTValue *tv = lj_tab_getstr(tabV(registry(L)), s);
24 if (tvistab(tv)) {
25 int hash = VMEVENT_HASH(ev);
26 tv = lj_tab_getint(tabV(tv), hash);
27 if (tv && tvisfunc(tv)) {
28 lj_state_checkstack(L, LUA_MINSTACK);
29 setfuncV(L, L->top++, funcV(tv));
30 if (LJ_FR2) setnilV(L->top++);
31 return savestack(L, L->top);
32 }
33 }
34 g->vmevmask &= ~VMEVENT_MASK(ev); /* No handler: cache this fact. */
35 return 0;
36}
37
38void lj_vmevent_call(lua_State *L, ptrdiff_t argbase)
39{
40 global_State *g = G(L);
41 uint8_t oldmask = g->vmevmask;
42 uint8_t oldh = hook_save(g);
43 int status;
44 g->vmevmask = 0; /* Disable all events. */
45 hook_vmevent(g);
46 status = lj_vm_pcall(L, restorestack(L, argbase), 0+1, 0);
47 if (LJ_UNLIKELY(status)) {
48 /* Really shouldn't use stderr here, but where else to complain? */
49 L->top--;
50 fputs("VM handler failed: ", stderr);
51 fputs(tvisstr(L->top) ? strVdata(L->top) : "?", stderr);
52 fputc('\n', stderr);
53 }
54 hook_restore(g, oldh);
55 if (g->vmevmask != VMEVENT_NOCACHE)
56 g->vmevmask = oldmask; /* Restore event mask, but not if not modified. */
57}
58
59