Re: [FEATURE REQUEST] Custom-naming of preloaded modules

[Dirk Laurie <dirk.laurie@...>]

2017-02-17 14:25 GMT+02:00 Roberto Ierusalimschy <roberto@inf.puc-rio.br>:
>> Patch to lua.c attached. Compiles warning-free as a Lua 5.2.4 patch but
>> gives a warning for incompatible types on 5.3.4 that I can't fix. Still works,
>> though.
>
>> 261,262c261,264
>> <   lua_getglobal(L, "require");
>> <   lua_pushstring(L, name);
>> ---
>> >   char *eq = strchr(name,'=');
>> >   lua_getglobal(L, "require");
>> >   if (eq==name) lua_pushstring(L, name);
>> >   else lua_pushstring(L, eq+1);
>
> The test 'eq==name' seems weird. Wouldn't it be true only when 'name'
> starts with "="?
>
>
>> 264,265c266,269
>> <   if (status == LUA_OK)
>> <     lua_setglobal(L, name);  /* global[name] = require return */
>> ---
>> >   if (status == LUA_OK) {
>> >     if (eq==name) lua_setglobal(L, name);  /* global[name] = require return */
>> >     else lua_setglobal(L, strndup(name,eq-name));
>> >   }
>
> 'strndup' is not ANSI, and it leaks memory when used like here.

My present version is:

static int dolibrary (lua_State *L, const char *name) {
  int status;
  char *eq = strchr(name,'=');
  lua_getglobal(L, "require");
  if (eq) lua_pushstring(L, eq+1);
  else lua_pushstring(L, name);
  status = docall(L, 1, 1);  /* call 'require(name)' */
  if (status == LUA_OK) {
    if (eq) *eq = 0;
    lua_setglobal(L, name);  /* global[name] = require return */
    if (eq) *eq = '=';
  }
  return report(L, status);
}

Luiz has neither approved nor rejected the temporary modification of
a character inside a "const char*", but the compiler is happy :-)