Re: Texinfo 6.7 released

[Gavin Smith]

> Maybe that's what we should do here as well.  'free' is a macro
> expanded into something implemented inside Perl, right?  And asprintf
> comes from Gnulib on MS-Windows, right?  So we have that problem I
> mentioned with allocation and free that come from different libraries.

Yes, that makes sense.

> I needed to add dTHX to 'init', or it wouldn't compile.

Didn't it compile before?

> So it looks like it indeed crashes when calling 'free' on storage
> allocated by asprintf.  With that in mind, I modified api.c as below:
>
> --- ./tp/Texinfo/XS/parsetexi/api.c.~1~ 2019-08-25 20:11:45.000000000 +0300
> +++ ./tp/Texinfo/XS/parsetexi/api.c     2019-09-28 10:50:13.319625000 +0300
> @@ -56,7 +56,8 @@ find_locales_dir (char *builddir)
>
>    dTHX;
>
> -  asprintf (&s, "%s/LocaleData", builddir);
> +  s = malloc (strlen (builddir) + strlen ("/LocaleData") + 1);
> +  sprintf (s, "%s/LocaleData", builddir);
>    dir = opendir (s);
>    if (!dir)
>      {
>
>
> and the problem went away.

Would you like to commit that change?

I don't know of a good way to avoid using the Perl version of free.
You could have "#undef free" followed by "#define free PerlMem_free",
but this would break if perl changes the way that it overrides "free".

> If this is the right fix, then I think we
> cannot use Gnulib's asprintf in Parsetexi, and there are a couple of
> other places with the same problem, which we need to fix as well,
> right?

Hopefully not: only if Perl headers are included in a file should
there be problems. I believe you successfully built and used the
Parsetexi module before on MS-Windows when asprintf was used in other
files.

I deliberately limited where the Perl headers were included: for
example, in tree_types.h a field of a struct is declared as a void
pointer rather than the Perl type it should be. The files where there
could be problems are api.c and Parsetexi.xs: it shouldn't be too hard
to avoid using asprintf there (or other functions which use the real
version of malloc).