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Hi Ranier,

I suggest you thoroughly test your changes and benchmark them before suggesting changes to the Lua source code, some won't give you any performance gains (and are likely even slower), and some others are plain wrong.



On 16/11/20 09:37, Ranier Vilela wrote:
Em dom., 15 de nov. de 2020 às 22:17, Andrew Gierth < <>> escreveu:

    >>>>> "Ranier" == Ranier Vilela <
    <>> writes:

     Ranier> -  if (strcmp(ar.namewhat, "method") == 0) {
     Ranier> +  if (strncmp(ar.namewhat, "method", 6) == 0) {

    That's obviously completely wrong, since it would then match any
    _starting with_ "method".

I still want to hear the Lua Team.
But if that is really the case, it is simple to resolve and continue to avoid calling strlen over and over again.
+if (strncmp(ar.namewhat, "method\0", 7) == 0) {

    All your other examples of strncmp are wrong for the same reason.

Same above.

     Ranier> 4. Avoid strlen at lua_pushstring, with a constant "k".

     Ranier> -    lua_pushstring(L, "k");
     Ranier> +    lua_pushlstring(L, "k", 1);

    This really isn't likely to be worth it.


     Ranier> 5. fgets returns char * pointer which needs to be compared to
     Ranier> NULL, not 0.

    0 is a valid way to say "the null pointer".

And that talks about NULL.
In addition, in Lua fgets it is used against NULL.
See at:
File lua.c:
         fgets (b, LUA_MAXINPUT, stdin)! = NULL) / * get line * /

     Ranier> Strchr is it's more efficient than strcmp.

    It also does something completely different, which is not applicable

Basically, it does a search for '-', which strchr is much more efficient.
In addition, strchr is used elsewhere in the code to do the same.

Ranier Vilela