static const char *getobjname (lua_State *L, StkId obj, const char **name) {
StkId func = aux_stackedfunction(L, 0, obj);
if (!isLmark(func))
return NULL; /* not an active Lua function */
else {
Proto *p = infovalue(func)->func->f.l;
int pc = currentpc(func);
int stackpos = obj - (func+1); /* func+1 == function base */
Instruction i = luaG_symbexec(p, pc, stackpos);
LUA_ASSERT(pc != -1, "function must be active");
switch (GET_OPCODE(i)) {
case OP_GETGLOBAL: {
*name = p->kstr[GETARG_U(i)]->str;
return "global";
}
case OP_GETLOCAL: {
*name = luaF_getlocalname(p, GETARG_U(i)+1, pc);
LUA_ASSERT(*name, "local must exist");
return "local";
}
case OP_PUSHSELF:
case OP_GETDOTTED: {
*name = p->kstr[GETARG_U(i)]->str;
return "field";
}
default:
return NULL; /* no useful name found */
}
}
}
static const char *
getobjname(CallInfo * ci, int stackpos, const char **name)
{
if (isLua(ci)) { /* a Lua function? */
Proto *p = ci_func(ci)->l.p;
int pc = currentpc(ci);
Instruction i;
*name = luaF_getlocalname(p, stackpos + 1, pc);
if (*name) /* is a local? */
return "local";
i = luaG_symbexec(p, pc, stackpos); /* try symbolic execution */
lua_assert(pc != -1);
switch (GET_OPCODE(i)) {
case OP_GETGLOBAL:
{
int g = GETARG_Bx(i); /* global index */
lua_assert(ttisstring(&p->k[g]));
*name = svalue(&p->k[g]);
return "global";
}
case OP_MOVE:
{
int a = GETARG_A(i);
int b = GETARG_B(i); /* move from `b' to `a' */
if (b < a)
return getobjname(ci, b, name); /* get name for `b' */
break;
}
case OP_GETTABLE:
{
int k = GETARG_C(i); /* key index */
*name = kname(p, k);
return "field";
}
case OP_SELF:
{
int k = GETARG_C(i); /* key index */
*name = kname(p, k);
return "method";
}
default:
break;
}
}
return NULL; /* no useful name found */
}
int luaG_checkcode (const Proto *pt) {
return luaG_symbexec(pt, pt->sizecode, NO_REG);
}