C++ setobj2t函数代码示例

void luaV_settable (lua_State *L, const TValue *t, TValue *key, StkId val) {
  int loop;
  TValue temp;
  for (loop = 0; loop < MAXTAGLOOP; loop++) {
    const TValue *tm;
    if (ttistable(t)) {  /* `t' is a table? */
      Table *h = hvalue(t);
      TValue *oldval = luaH_set(L, h, key); /* do a primitive set */
      if (!ttisnil(oldval) ||  /* result is no nil? */
          (tm = fasttm(L, h->metatable, TM_NEWINDEX)) == NULL) { /* or no TM? */
        setobj2t(L, oldval, val);
        luaC_barriert(L, h, val);
        return;
      }
      /* else will try the tag method */
    }
    else if (ttisnil(tm = luaT_gettmbyobj(L, t, TM_NEWINDEX)))
      luaG_typeerror(L, t, "index");
    if (ttisfunction(tm)) {
      callTM(L, tm, t, key, val);
      return;
    }
    /* else repeat with `tm' */
    setobj(L, &temp, tm);  /* avoid pointing inside table (may rehash) */
    t = &temp;
  }
  luaG_runerror(L, "loop in settable");
}

void luaV_settable (lua_State *L, const TValue *t, TValue *key, StkId val) {
  int loop;
  for (loop = 0; loop < MAXTAGLOOP; loop++) {
    const TValue *tm;
    if (ttistable(t)) {  /* `t' is a table? */
      Table *h = hvalue(t);
      TValue *oldval = cast(TValue *, luaH_get(h, key));
      /* if previous value is not nil, there must be a previous entry
         in the table; moreover, a metamethod has no relevance */
      if (!ttisnil(oldval) ||
         /* previous value is nil; must check the metamethod */
         ((tm = fasttm(L, h->metatable, TM_NEWINDEX)) == NULL &&
         /* no metamethod; is there a previous entry in the table? */
         (oldval != luaO_nilobject ||
         /* no previous entry; must create one. (The next test is
            always true; we only need the assignment.) */
         (oldval = luaH_newkey(L, h, key), 1)))) {
        /* no metamethod and (now) there is an entry with given key */
        setobj2t(L, oldval, val);  /* assign new value to that entry */
        invalidateTMcache(h);
        luaC_barrierback(L, obj2gco(h), val);
        return;
      }
      /* else will try the metamethod */
    }
    else  /* not a table; check metamethod */
      if (ttisnil(tm = luaT_gettmbyobj(L, t, TM_NEWINDEX)))
        luaG_typeerror(L, t, "index");
    /* there is a metamethod */
    if (ttisfunction(tm)) {
      callTM(L, tm, t, key, val, 0);
      return;
    }
    t = tm;  /* else repeat with 'tm' */
  }

/*
** open parts of the state that may cause memory-allocation errors
*/
static void f_luaopen (lua_State *L, void *ud) {
  global_State *g = G(L);
  UNUSED(ud);
  stack_init(L, L);  /* init stack */
  init_registry(L, g);
#if LUA_FASTREF_SUPPORT
  {
    TValue n;

    sethvalue(L, &G(L)->l_refs, luaH_new(L, 1, 0));  /* refs */
	setnvalue(&n, 0);
    setobj2t(L, luaH_setnum(L, hvalue(&G(L)->l_refs), LUA_RIDX_FASTREF_FREELIST), &n);

    setnilvalue(&g->fastrefNilValue);
  }
#endif /* LUA_FASTREF_SUPPORT */
  luaS_resize(L, MINSTRTABSIZE);  /* initial size of string table */
  luaT_init(L);
  luaX_init(L);
  /* pre-create memory-error message */
  g->memerrmsg = luaS_newliteral(L, MEMERRMSG);
  luaS_fix(g->memerrmsg);  /* it should never be collected */
  g->gcrunning = 1;  /* allow gc */
  g->version = lua_version(NULL);
  luai_userstateopen(L);
}

void luaV_settable (lua_State *L, const TValue *t, TValue *key, StkId val) {
  int loop;
  for (loop = 0; loop < MAXTAGLOOP; loop++) {
    const TValue *tm;
    if (ttistable(t) || ttisrotable(t)) {  /* `t' is a table? */
      void *h = ttistable(t) ? hvalue(t) : rvalue(t);
      TValue *oldval = ttistable(t) ? luaH_set(L, (Table*)h, key) : NULL; /* do a primitive set */
      if ((oldval && !ttisnil(oldval)) ||  /* result is no nil? */
          (tm = fasttm(L, ttistable(t) ? ((Table*)h)->metatable : (Table*)luaR_getmeta(h), TM_NEWINDEX)) == NULL) { /* or no TM? */
        if(oldval) {
          setobj2t(L, oldval, val);
          luaC_barriert(L, (Table*)h, val);
        }
        return;
      }
      /* else will try the tag method */
    }
    else if (ttisnil(tm = luaT_gettmbyobj(L, t, TM_NEWINDEX)))
      luaG_typeerror(L, t, "index");
    if (ttisfunction(tm) || ttislightfunction(tm)) {
      callTM(L, tm, t, key, val);
      return;
    }
    t = tm;  /* else repeat with `tm' */ 
  }
  luaG_runerror(L, "loop in settable");
}

LUA_API void lua_rawseti (lua_State *L, int idx, int n) {
  StkId o;
  lua_lock(L);
  api_checknelems(L, 1);
  o = luaA_index(L, idx);
  api_check(L, ttistable(o));
  setobj2t(luaH_setnum(L, hvalue(o), n), L->top-1);  /* write barrier */
  L->top--;
  lua_unlock(L);
}

LUA_API void lua_rawset (lua_State *L, int idx) {
  StkId t;
  lua_lock(L);
  api_checknelems(L, 2);
  t = luaA_index(L, idx);
  api_check(L, ttistable(t));
  setobj2t(luaH_set(L, hvalue(t), L->top-2), L->top-1);  /* write barrier */
  L->top -= 2;
  lua_unlock(L);
}

LUA_API void lua_rawset (lua_State *L, int idx) {
  StkId t;
  lua_lock(L);
  api_checknelems(L, 2);
  t = index2addr(L, idx);
  api_check(L, ttistable(t), "table expected");
  setobj2t(L, luaH_set(L, hvalue(t), L->top-2), L->top-1);
  invalidateTMcache(hvalue(t));
  luaC_barrierback(L, gcvalue(t), L->top-1);
  L->top -= 2;
  lua_unlock(L);
}

LUA_API void lua_rawsetp (lua_State *L, int idx, const void *p) {
  StkId t;
  TValue k;
  lua_lock(L);
  api_checknelems(L, 1);
  t = index2addr(L, idx);
  api_check(L, ttistable(t), "table expected");
  setpvalue(&k, cast(void *, p));
  setobj2t(L, luaH_set(L, hvalue(t), &k), L->top - 1);
  luaC_barrierback(L, gcvalue(t), L->top - 1);
  L->top--;
  lua_unlock(L);
}

LUA_API void lua_rawseti (lua_State *L, int idx, int n) {
  StkId o;
  lua_lock(L);
  api_checknelems(L, 1);
  o = luaA_index(L, idx);
  api_check(L, ttistable(o));
  setobj2t(luaH_setnum(L, hvalue(o), n), L->top-1);  /* write barrier */
#if LUA_REFCOUNT
  setnilvalue(--L->top);
#else !LUA_REFCOUNT
  L->top--;
#endif LUA_REFCOUNT
  lua_unlock(L);
}

void luaV_settable (lua_State *L, const TValue *t, TValue *key, StkId val) {
  TValue tmp;
  int loop;
  for (loop = 0; loop < MAXTAGLOOP; loop++) {
    const TValue *tm;
    if (ttistable(t)) {  /* `t' is a table? */
      Table *h = hvalue(t);
      TValue *oldval = luaH_set(L, h, key); /* do a primitive set */
      if (!ttisnil(oldval) ||  /* result is no nil? */
          (tm = fasttm(L, h->metatable, TM_NEWINDEX)) == NULL) { /* or no TM? */
        setobj2t(L, oldval, val);
        luaC_barriert(L, h, val);
#if LUA_REFCOUNT
        if (ttisnil(val)) {
          Node* keyNode = luaH_getkey(h, key);
          if (keyNode) {
            luaH_removekey(L, h, keyNode);
          }
        }
#endif /* LUA_REFCOUNT */
        return;
      }
      /* else will try the tag method */
    }
    else if (ttisnil(tm = luaT_gettmbyobj(L, t, TM_NEWINDEX)))
      luaG_typeerror(L, t, "index");
    if (ttisfunction(tm)) {
      callTM(L, tm, t, key, val);
#if LUA_REFCOUNT
      {
        TValue *newval;
        if (ttistable(t)) {
          newval = luaH_set(L, hvalue(t), key);
          if (ttisnil(newval)) {
            Node* keyNode = luaH_getkey(hvalue(t), key);
            if (keyNode)
              luaH_removekey(L, hvalue(t), keyNode);
          }
        }
      }
#endif /* LUA_REFCOUNT */
      return;
    }
    setobj(L, &tmp, tm);
    t = &tmp;  /* else repeat with copy of `tm' */
  }
  luaG_runerror(L, "loop in settable");
}

LUA_API void lua_rawset (lua_State *L, int idx) {
  StkId t;
  lua_lock(L);
  api_checknelems(L, 2);
  t = luaA_index(L, idx);
  api_check(L, ttistable(t));
  setobj2t(luaH_set(L, hvalue(t), L->top-2), L->top-1);  /* write barrier */
#if LUA_REFCOUNT
  setnilvalue(--L->top);
  setnilvalue(--L->top);
#else !LUA_REFCOUNT
  L->top -= 2;
#endif LUA_REFCOUNT

  lua_unlock(L);
}

void luaV_settable (lua_State *L, const TValue *t, TValue *key, StkId val) {
  int loop;
  TValue temp;
  setnilvalue(L->top);
  L->top++;
  fixedstack(L);
  for (loop = 0; loop < MAXTAGLOOP; loop++) {
    const TValue *tm;
    if (ttistable(t) || ttisrotable(t)) {  /* `t' is a table? */
      void *h = ttistable(t) ? hvalue(t) : rvalue(t);
      TValue *oldval = ttistable(t) ? luaH_set(L, (Table*)h, key) : NULL; /* do a primitive set */
      if ((oldval && !ttisnil(oldval)) ||  /* result is no nil? */
          (tm = fasttm(L, ttistable(t) ? ((Table*)h)->metatable : (Table*)luaR_getmeta(h), TM_NEWINDEX)) == NULL) { /* or no TM? */
        if(oldval) {
          L->top--;
          unfixedstack(L);
          setobj2t(L, oldval, val);
          ((Table *)h)->flags = 0;
          luaC_barriert(L, (Table*)h, val);
        }
        return;
      }
      /* else will try the tag method */
    }
    else if (ttisnil(tm = luaT_gettmbyobj(L, t, TM_NEWINDEX)))
      luaG_typeerror(L, t, "index");
    if (ttisfunction(tm) || ttislightfunction(tm)) {
      L->top--;
      unfixedstack(L);
      callTM(L, tm, t, key, val);
      return;
    }
    /* else repeat with `tm' */
    setobj(L, &temp, tm);  /* avoid pointing inside table (may rehash) */
    t = &temp;
    setobj2s(L, L->top-1, t);  /* need to protect value from EGC. */
  }
  luaG_runerror(L, "loop in settable");
}

void vm_OP_SETLIST(lua_State *L, int a, int b, int c) {
  TValue *base = L->base;
  TValue *ra = base + a;
  int last;
  Table *h;
  fixedstack(L);
  if (b == 0) {
    b = cast_int(L->top - ra) - 1;
    L->top = L->ci->top;
  }
  runtime_check(L, ttistable(ra));
  h = hvalue(ra);
  last = ((c-1)*LFIELDS_PER_FLUSH) + b;
  if (last > h->sizearray)  /* needs more space? */
    luaH_resizearray(L, h, last);  /* pre-alloc it at once */
  for (; b > 0; b--) {
    TValue *val = ra+b;
    setobj2t(L, luaH_setnum(L, h, last--), val);
    luaC_barriert(L, h, val);
  }
  unfixedstack(L);
}

/*
** Receives table at `t', key at `key' and value at `val'.
*/
void luaV_settable (lua_State *L, const TObject *t, TObject *key, StkId val) {
  const TObject *tm;
  int loop = 0;
  do {
    if (ttistable(t)) {  /* `t' is a table? */
      Table *h = hvalue(t);
      TObject *oldval = luaH_set(L, h, key); /* do a primitive set */
      if (!ttisnil(oldval) ||  /* result is no nil? */
          (tm = fasttm(L, h->metatable, TM_NEWINDEX)) == NULL) { /* or no TM? */
        setobj2t(oldval, val);  /* write barrier */
        return;
      }
      /* else will try the tag method */
    }
    else if (ttisnil(tm = luaT_gettmbyobj(L, t, TM_NEWINDEX)))
      luaG_typeerror(L, t, "index");
    if (ttisfunction(tm)) {
      callTM(L, tm, t, key, val);
      return;
    }
    t = tm;  /* else repeat with `tm' */ 
  } while (++loop <= MAXTAGLOOP);
  luaG_runerror(L, "loop in settable");
}

//.........这里部分代码省略.........
          nresults = GETARG_C(*(ci->u.l.savedpc - 1)) - 1;
          luaD_poscall(L, nresults, ra);
          if (nresults >= 0) L->top = L->ci->top;
          goto retentry;
        }
      }
      case OP_FORLOOP: {
        lua_Number step, idx, limit;
        const TObject *plimit = ra+1;
        const TObject *pstep = ra+2;
        if (!ttisnumber(ra))
          luaG_runerror(L, "`for' initial value must be a number");
        if (!tonumber(plimit, ra+1))
          luaG_runerror(L, "`for' limit must be a number");
        if (!tonumber(pstep, ra+2))
          luaG_runerror(L, "`for' step must be a number");
        step = nvalue(pstep);
        idx = nvalue(ra) + step;  /* increment index */
        limit = nvalue(plimit);
        if (step > 0 ? idx <= limit : idx >= limit) {
          dojump(pc, GETARG_sBx(i));  /* jump back */
          chgnvalue(ra, idx);  /* update index */
        }
        break;
      }
      case OP_TFORLOOP: {
        int nvar = GETARG_C(i) + 1;
        StkId cb = ra + nvar + 2;  /* call base */
        setobjs2s(cb, ra);
        setobjs2s(cb+1, ra+1);
        setobjs2s(cb+2, ra+2);
        L->top = cb+3;  /* func. + 2 args (state and index) */
        luaD_call(L, cb, nvar);
        L->top = L->ci->top;
        ra = XRA(i) + 2;  /* final position of first result */
        cb = ra + nvar;
        do {  /* move results to proper positions */
          nvar--;
          setobjs2s(ra+nvar, cb+nvar);
        } while (nvar > 0);
        if (ttisnil(ra))  /* break loop? */
          pc++;  /* skip jump (break loop) */
        else
          dojump(pc, GETARG_sBx(*pc) + 1);  /* jump back */
        break;
      }
      case OP_TFORPREP: {  /* for compatibility only */
        if (ttistable(ra)) {
          setobjs2s(ra+1, ra);
          setobj2s(ra, luaH_getstr(hvalue(gt(L)), luaS_new(L, "next")));
        }
        dojump(pc, GETARG_sBx(i));
        break;
      }
      case OP_SETLIST:
      case OP_SETLISTO: {
        int bc;
        int n;
        Table *h;
        runtime_check(L, ttistable(ra));
        h = hvalue(ra);
        bc = GETARG_Bx(i);
        if (GET_OPCODE(i) == OP_SETLIST)
          n = (bc&(LFIELDS_PER_FLUSH-1)) + 1;
        else {
          n = L->top - ra - 1;
          L->top = L->ci->top;
        }
        bc &= ~(LFIELDS_PER_FLUSH-1);  /* bc = bc - bc%FPF */
        for (; n > 0; n--)
          setobj2t(luaH_setnum(L, h, bc+n), ra+n);  /* write barrier */
        break;
      }
      case OP_CLOSE: {
        luaF_close(L, ra);
        break;
      }
      case OP_CLOSURE: {
        Proto *p;
        Closure *ncl;
        int nup, j;
        p = cl->p->p[GETARG_Bx(i)];
        nup = p->nups;
        ncl = luaF_newLclosure(L, nup, &cl->g);
        ncl->l.p = p;
        for (j=0; j<nup; j++, pc++) {
          if (GET_OPCODE(*pc) == OP_GETUPVAL)
            ncl->l.upvals[j] = cl->upvals[GETARG_B(*pc)];
          else {
            lua_assert(GET_OPCODE(*pc) == OP_MOVE);
            ncl->l.upvals[j] = luaF_findupval(L, base + GETARG_B(*pc));
          }
        }
        setclvalue(ra, ncl);
        luaC_checkGC(L);
        break;
      }
    }
  }
}