Function luaL_traceback

lib/lua/src/lauxlib.c:132–165

LUALIB_API void luaL_traceback (lua_State *L, lua_State *L1,
                                const char *msg, int level) {
  luaL_Buffer b;
  lua_Debug ar;
  int last = lastlevel(L1);
  int limit2show = (last - level > LEVELS1 + LEVELS2) ? LEVELS1 : -1;
  luaL_buffinit(L, &b);
  if (msg) {
    luaL_addstring(&b, msg);
    luaL_addchar(&b, '\n');
  }
  luaL_addstring(&b, "stack traceback:");
  while (lua_getstack(L1, level++, &ar)) {
    if (limit2show-- == 0) {  /* too many levels? */
      int n = last - level - LEVELS2 + 1;  /* number of levels to skip */
      lua_pushfstring(L, "\n\t...\t(skipping %d levels)", n);
      luaL_addvalue(&b);  /* add warning about skip */
      level += n;  /* and skip to last levels */
    }
    else {
      lua_getinfo(L1, "Slnt", &ar);
      if (ar.currentline <= 0)
        lua_pushfstring(L, "\n\t%s: in ", ar.short_src);
      else
        lua_pushfstring(L, "\n\t%s:%d: in ", ar.short_src, ar.currentline);
      luaL_addvalue(&b);
      pushfuncname(L, &ar);
      luaL_addvalue(&b);
      if (ar.istailcall)
        luaL_addstring(&b, "\n\t(...tail calls...)");
    }
  }
  luaL_pushresult(&b);
}

/* }====================================================== */