Function luaK_self

third-party/lua-5.5.0/src/lcode.c:1321–1341

** Emit SELF instruction or equivalent: the code will convert ** expression 'e' into 'e.key(e,'. */

** expression 'e' into 'e.key(e,'.
*/
void luaK_self (FuncState *fs, expdesc *e, expdesc *key) {
  int ereg, base;
  luaK_exp2anyreg(fs, e);
  ereg = e->u.info;  /* register where 'e' (the receiver) was placed */
  freeexp(fs, e);
  base = e->u.info = fs->freereg;  /* base register for op_self */
  e->k = VNONRELOC;  /* self expression has a fixed register */
  luaK_reserveregs(fs, 2);  /* method and 'self' produced by op_self */
  lua_assert(key->k == VKSTR);
  /* is method name a short string in a valid K index? */
  if (strisshr(key->u.strval) && luaK_exp2K(fs, key)) {
    /* can use 'self' opcode */
    luaK_codeABCk(fs, OP_SELF, base, ereg, key->u.info, 0);
  }
  else {  /* cannot use 'self' opcode; use move+gettable */
    luaK_exp2anyreg(fs, key);  /* put method name in a register */
    luaK_codeABC(fs, OP_MOVE, base + 1, ereg, 0);  /* copy self to base+1 */
    luaK_codeABC(fs, OP_GETTABLE, base, ereg, key->u.info);  /* get method */
  }
  freeexp(fs, key);
}


/* auxiliary function to define indexing expressions */