C++ setsvalue2s函数代码示例

int luaV_tostring (lua_State *L, StkId obj) {
  if (!ttisnumber(obj))
    return 0;
  else {
    char s[LUAI_MAXNUMBER2STR];
    lua_Number n = nvalue(obj);
    int l = lua_number2str(s, n);
    setsvalue2s(L, obj, luaS_newlstr(L, s, l));
    return 1;
  }
}

LUA_API int lua_getglobal (lua_State *L, const char *name) {
  Table *reg = hvalue(&G(L)->l_registry);
  const TValue *gt;  /* global table */
  lua_lock(L);
  gt = luaH_getint(reg, LUA_RIDX_GLOBALS);
  setsvalue2s(L, L->top, luaS_new(L, name));
  api_incr_top(L);
  luaV_gettable(L, gt, L->top - 1, L->top - 1);
  lua_unlock(L);
  return ttnov(L->top - 1);
}

LUA_API void lua_setfield (lua_State *L, int idx, const char *k) {
  StkId t;
  lua_lock(L);
  api_checknelems(L, 1);
  t = index2addr(L, idx);
  api_checkvalidindex(L, t);
  setsvalue2s(L, L->top++, luaS_new(L, k));
  luaV_settable(L, t, L->top - 1, L->top - 2);
  L->top -= 2;  /* pop value and key */
  lua_unlock(L);
}

LUA_API void lua_setglobal (lua_State *L, const char *var) {
  Table *reg = hvalue(&G(L)->l_registry);
  const TValue *gt;  /* global table */
  lua_lock(L);
  api_checknelems(L, 1);
  gt = luaH_getint(reg, LUA_RIDX_GLOBALS);
  setsvalue2s(L, L->top++, luaS_new(L, var));
  luaV_settable(L, gt, L->top - 1, L->top - 2);
  L->top -= 2;  /* pop value and key */
  lua_unlock(L);
}

void luaD_seterrorobj (lua_State *L, int errcode, StkId oldtop) {
  switch (errcode) {
    case LUA_ERRMEM: {
      ptrdiff_t oldtopr = savestack(L, oldtop);
      setsvalue2s(L, restorestack(L, oldtopr), luaS_newliteral(L, MEMERRMSG));
      break;
    }
    case LUA_ERRERR: {
      ptrdiff_t oldtopr = savestack(L, oldtop);
      setsvalue2s(L, restorestack(L, oldtopr), luaS_newliteral(L, "error in error handling"));
      break;
    }
    case LUA_ERRSYNTAX:
    case LUA_ERRRUN: {
      setobjs2s(L, oldtop, L->top - 1);  /* error message on current top */
      break;
    }
  }
  L->top = oldtop + 1;
}

int ICACHE_FLASH_ATTR luaV_tostring (lua_State *L, StkId obj) {
  if (!ttisnumber(obj))
    return 0;
  else {
    char s[LUAI_MAXNUMBER2STR];
    lua_Number n = nvalue(obj);
    lua_number2str(s, n);
    setsvalue2s(L, obj, luaS_new(L, s));
    return 1;
  }
}

/* this function handles only `%d', `%c', %f, %p, and `%s' formats */
const char *luaO_pushvfstring (lua_State *L, const char *fmt, va_list argp) {
  int n = 0;
  for (;;) {
    const char *e = strchr(fmt, '%');
    if (e == NULL) break;
    setsvalue2s(L, L->top, luaS_newlstr(L, fmt, e-fmt));
    incr_top(L);
    switch (*(e+1)) {
      case 's': {
        const char *s = va_arg(argp, char *);
        if (s == NULL) s = "(null)";
        pushstr(L, s, strlen(s));
        break;
      }
      case 'c': {
        char buff;
        buff = cast(char, va_arg(argp, int));
        pushstr(L, &buff, 1);
        break;
      }
      case 'd': {
        setnvalue(L->top, cast_num(va_arg(argp, int)));
        incr_top(L);
        break;
      }
      case 'f': {
      	// Floats passed through ... are promoted to doubles...
        setnvalue(L->top, cast_num(va_arg(argp, double)));
        incr_top(L);
        break;
      }
      case 'p': {
        char buff[4*sizeof(void *) + 8]; /* should be enough space for a `%p' */
        int l = sprintf(buff, "%p", va_arg(argp, void *));
        pushstr(L, buff, l);
        break;
      }
      case '%': {
        pushstr(L, "%", 1);
        break;
      }
      default: {
        luaG_runerror(L,
            "invalid option " LUA_QL("%%%c") " to " LUA_QL("lua_pushfstring"),
            *(e + 1));
      }
    }
    n += 2;
    fmt = e+2;
  }
  pushstr(L, fmt, strlen(fmt));
  if (n > 0) luaV_concat(L, n + 1);
  return svalue(L->top - 1);
}

int luaV_tostring (lua_State *L, StkId obj) {
  if (!ttisnumber(obj))
    return 0;
  else {
    char s[LUAI_MAXNUMBER2STR];
    ptrdiff_t objr = savestack(L, obj);
    lua_Number n = nvalue(obj);
    lua_number2str(s, n);
    setsvalue2s(L, restorestack(L, objr), luaS_new(L, s));
    return 1;
  }
}

void luaV_concat (lua_State *L, int total) {
  lua_assert(total >= 2);
  do {
    StkId top = L->top;
    int n = 2;  /* number of elements handled in this pass (at least 2) */
    if (!(ttisstring(top-2) || ttisnumber(top-2)) || !tostring(L, top-1)) {
      if (!call_binTM(L, top-2, top-1, top-2, TM_CONCAT))
        luaG_concaterror(L, top-2, top-1);
    }
    else if (tsvalue(top-1)->len == 0)  /* second operand is empty? */
      (void)tostring(L, top - 2);  /* result is first operand */
    else if (ttisstring(top-2) && tsvalue(top-2)->len == 0) {
      setsvalue2s(L, top-2, rawtsvalue(top-1));  /* result is second op. */
    }
    else {
      /* at least two non-empty string values; get as many as possible */
      size_t tl = tsvalue(top-1)->len;
      char *buffer;
      int i;
      /* collect total length */
      for (i = 1; i < total && tostring(L, top-i-1); i++) {
        size_t l = tsvalue(top-i-1)->len;
        if (l >= (MAX_SIZET/sizeof(char)) - tl)
          luaG_runerror(L, "string length overflow");
        tl += l;
      }
      buffer = luaZ_openspace(L, &G(L)->buff, tl);
      tl = 0;
      n = i;
      do {  /* concat all strings */
        size_t l = tsvalue(top-i)->len;
        memcpy(buffer+tl, svalue(top-i), l * sizeof(char));
        tl += l;
      } while (--i > 0);
      setsvalue2s(L, top-n, luaS_newlstr(L, buffer, tl));
    }
    total -= n-1;  /* got 'n' strings to create 1 new */
    L->top -= n-1;  /* popped 'n' strings and pushed one */
  } while (total > 1);  /* repeat until only 1 result left */
}

/*
** t[k] = value at the top of the stack (where 'k' is a string)
*/
static void auxsetstr (lua_State *L, const TValue *t, const char *k) {
  const TValue *slot;
  TString *str = luaS_new(L, k);
  api_checknelems(L, 1);
  if (luaV_fastset(L, t, str, slot, luaH_getstr, L->top - 1))
    L->top--;  /* pop value */
  else {
    setsvalue2s(L, L->top, str);  /* push 'str' (to make it a TValue) */
    api_incr_top(L);
    luaV_finishset(L, t, L->top - 1, L->top - 2, slot);
    L->top -= 2;  /* pop value and key */
  }
  lua_unlock(L);  /* lock done by caller */
}

LUA_API const char *lua_pushstring (lua_State *L, const char *s) {
  lua_lock(L);
  if (s == NULL)
    setnilvalue(L->top);
  else {
    TString *ts;
    luaC_checkGC(L);
    ts = luaS_new(L, s);
    setsvalue2s(L, L->top, ts);
    s = getstr(ts);  /* internal copy's address */
  }
  api_incr_top(L);
  lua_unlock(L);
  return s;
}

static int auxgetstr (lua_State *L, const TValue *t, const char *k) {
  const TValue *slot;
  TString *str = luaS_new(L, k);
  if (luaV_fastget(L, t, str, slot, luaH_getstr)) {
    setobj2s(L, L->top, slot);
    api_incr_top(L);
  }
  else {
    setsvalue2s(L, L->top, str);
    api_incr_top(L);
    luaV_finishget(L, t, L->top - 1, L->top - 1, slot);
  }
  lua_unlock(L);
  return ttnov(L->top - 1);
}

LUA_API const char *lua_pushstring (lua_State *L, const char *s) {
  if (s == NULL) {
    lua_pushnil(L);
    return NULL;
  }
  else {
    TString *ts;
    lua_lock(L);
    luaC_checkGC(L);
    ts = luaS_new(L, s);
    setsvalue2s(L, L->top, ts);
    api_incr_top(L);
    lua_unlock(L);
    return getstr(ts);
  }
}

LUA_API const char *LUA_pushstring (LUA_State *L, const char *s) {
  if (s == NULL) {
    LUA_pushnil(L);
    return NULL;
  }
  else {
    TString *ts;
    LUA_lock(L);
    LUAC_checkGC(L);
    ts = LUAS_new(L, s);
    setsvalue2s(L, L->top, ts);
    api_incr_top(L);
    LUA_unlock(L);
    return getstr(ts);
  }
}

int luaG_ordererror (lua_State *L, const TValue *p1, const TValue *p2) {
  //logt("luaG_ordererror");
  const char *t1 = luaT_typenames[ttype(p1)];
  const char *t2 = luaT_typenames[ttype(p2)];
#if 0
  // This does not cause a crash on Symbian.
  setsvalue2s(L, L->top, luaS_new(L, "dummy message"));
  incr_top(L);
  luaD_throw(L, LUA_ERRRUN);
#else
  if (t1[2] == t2[2])
    luaG_runerror_m(L, "attempt to compare two %s values", t1);
  else
    luaG_runerror_m(L, "attempt to compare %s with %s", t1, t2);
#endif
  return 0;
}