/* Return bytecode position for function/frame or NO_BCPOS. */
static BCPos debug_framepc(lua_State *L, GCfunc *fn, cTValue *nextframe)
{
const BCIns *ins;
GCproto *pt;
BCPos pos;
lua_assert(fn->c.gct == ~LJ_TFUNC || fn->c.gct == ~LJ_TTHREAD);
if (!isluafunc(fn)) { /* Cannot derive a PC for non-Lua functions. */
return NO_BCPOS;
} else if (nextframe == NULL) { /* Lua function on top. */
void *cf = cframe_raw(L->cframe);
if (cf == NULL || (char *)cframe_pc(cf) == (char *)cframe_L(cf))
return NO_BCPOS;
ins = cframe_pc(cf); /* Only happens during error/hook handling. */
} else {
if (frame_islua(nextframe)) {
ins = frame_pc(nextframe);
} else if (frame_iscont(nextframe)) {
ins = frame_contpc(nextframe);
} else {
/* Lua function below errfunc/gc/hook: find cframe to get the PC. */
void *cf = cframe_raw(L->cframe);
TValue *f = L->base-1;
for (;;) {
if (cf == NULL)
return NO_BCPOS;
while (cframe_nres(cf) < 0) {
if (f >= restorestack(L, -cframe_nres(cf)))
break;
cf = cframe_raw(cframe_prev(cf));
if (cf == NULL)
return NO_BCPOS;
}
if (f < nextframe)
break;
if (frame_islua(f)) {
f = frame_prevl(f);
} else {
if (frame_isc(f) || (LJ_HASFFI && frame_iscont(f) &&
(f-1)->u32.lo == LJ_CONT_FFI_CALLBACK))
cf = cframe_raw(cframe_prev(cf));
f = frame_prevd(f);
}
}
ins = cframe_pc(cf);
}
}
pt = funcproto(fn);
pos = proto_bcpos(pt, ins) - 1;
#if LJ_HASJIT
if (pos > pt->sizebc) { /* Undo the effects of lj_trace_exit for JLOOP. */
GCtrace *T = (GCtrace *)((char *)(ins-1) - offsetof(GCtrace, startins));
lua_assert(bc_isret(bc_op(ins[-1])));
pos = proto_bcpos(pt, mref(T->startpc, const BCIns));
}
/* Instruction dispatch. Used by instr/line/return hooks or when recording. */
void LJ_FASTCALL lj_dispatch_ins(lua_State *L, const BCIns *pc)
{
GCfunc *fn = curr_func(L);
GCproto *pt = funcproto(fn);
void *cf = cframe_raw(L->cframe);
const BCIns *oldpc = cframe_pc(cf);
global_State *g = G(L);
BCReg slots;
setcframe_pc(cf, pc);
slots = cur_topslot(pt, pc, cframe_multres_n(cf));
L->top = L->base + slots; /* Fix top. */
#if LJ_HASJIT
{
jit_State *J = G2J(g);
if (J->state != LJ_TRACE_IDLE) {
J->L = L;
lj_trace_ins(J, pc-1); /* The interpreter bytecode PC is offset by 1. */
}
}
#endif
if ((g->hookmask & LUA_MASKCOUNT) && g->hookcount == 0) {
g->hookcount = g->hookcstart;
callhook(L, LUA_HOOKCOUNT, -1);
L->top = L->base + slots; /* Fix top again. */
}
if ((g->hookmask & LUA_MASKLINE)) {
BCPos npc = proto_bcpos(pt, pc) - 1;
BCPos opc = proto_bcpos(pt, oldpc) - 1;
BCLine line = proto_line(pt, npc);
if (pc <= oldpc || opc >= pt->sizebc || line != proto_line(pt, opc)) {
callhook(L, LUA_HOOKLINE, line);
L->top = L->base + slots; /* Fix top again. */
}
}
if ((g->hookmask & LUA_MASKRET) && bc_isret(bc_op(pc[-1])))
callhook(L, LUA_HOOKRET, -1);
}