Re: Perl compilation/link flags for building XSParagraph

[Eli Zaretskii]

> From: Gavin Smith <address@hidden>
> Date: Wed, 14 Sep 2016 19:14:39 +0100
> Cc: Texinfo <address@hidden>
> 
> What comes to mind is to use another variable PERL_EXT_CC which would
> be set in the same way as CC, assuming that is a valid trick to use
> with libtool. configure.ac could check if PERL_EXT_CC is defined, and
> if it is, use its value as the value of CC instead of using the
> compiler that Perl says it needs.

Yes, but that is dangerous, since we should really heed to what Perl
says.  It also requires to run Perl by hand, to get the compiler
command, and then use it in PERL_EXT_CC.  OTOH, adding switches that
don't contradict what Perl requires should be harmless.

> > Bottom line, I think that the XSParagraph configure script should
> > append the value of PERL_EXT_LDFLAGS to the value of CC it uses when
> > it builds the libtool script, because otherwise most values of that
> > variable will have no effect.  Not sure if the same problem exists
> > with PERL_EXT_CFLAGS and PERL_EXT_CPPFLAGS.
> 
> Wouldn't this reasoning also apply if LDFLAGS was being set directly
> by the user, not via PERL_EXT_LDFLAGS? But it is not standard practice
> AFAIK always to append LDFLAGS to CC when using libtool.

I think it isn't standard because libtool will ignore most switches.

If you are asking specifically in the context of Texinfo and Perl
extensions, then it seems to me that LDFLAGS cannot be used here for
the same reason CC cannot: Perl might require different switches than
when linking, say, the stand-alone Info reader.