Function luaY_parser

third-party/lua-5.3.5/src/lparser.c:1626–1649

LClosure *luaY_parser (lua_State *L, ZIO *z, Mbuffer *buff,
                       Dyndata *dyd, const char *name, int firstchar) {
  LexState lexstate;
  FuncState funcstate;
  LClosure *cl = luaF_newLclosure(L, 1);  /* create main closure */
  setclLvalue(L, L->top, cl);  /* anchor it (to avoid being collected) */
  luaD_inctop(L);
  lexstate.h = luaH_new(L);  /* create table for scanner */
  sethvalue(L, L->top, lexstate.h);  /* anchor it */
  luaD_inctop(L);
  funcstate.f = cl->p = luaF_newproto(L);
  funcstate.f->source = luaS_new(L, name);  /* create and anchor TString */
  lua_assert(iswhite(funcstate.f));  /* do not need barrier here */
  lexstate.buff = buff;
  lexstate.dyd = dyd;
  dyd->actvar.n = dyd->gt.n = dyd->label.n = 0;
  luaX_setinput(L, &lexstate, z, funcstate.f->source, firstchar);
  mainfunc(&lexstate, &funcstate);
  lua_assert(!funcstate.prev && funcstate.nups == 1 && !lexstate.fs);
  /* all scopes should be correctly finished */
  lua_assert(dyd->actvar.n == 0 && dyd->gt.n == 0 && dyd->label.n == 0);
  L->top--;  /* remove scanner's table */
  return cl;  /* closure is on the stack, too */
}