Re: build problems with wxGTK 3.0

[Ethan A M. <sf...@us...>]

On Thursday, 19 June, 2014 22:27:46 Mojca Miklavec wrote:
> On Thu, Jun 19, 2014 at 9:31 PM, Ethan A Merritt

> >> So please also check whether wxWidgets are using gtk2 or gtk3 before
> >> calling pkg-config to supply build flags.
> >
> > That's a chicken-or-egg dilemma.
> > wx-config is supposed to tell us the version, but we need the version in
> > order to call the correct wx-config.
> 
> I don't see any chicken here ;)
> 
> Once gnuplot calls
>     WX_CXXFLAGS="`$WX_CONFIG --cxxflags
> it already knows which $WX_CONFIG it is calling.
> 
> The problematic line is only
>     PKG_CHECK_MODULES(GTK, [gtk+-2.0], have_gtk=yes, have_gtk=no)
> 
> Gnuplot should run
>     "$WX_CONFIG" --basename | <grep something>
> before asking for gtk+-2.0.

On linux (at least on my machines) there are two different wx-configs,
one for wx2 and one for wx3.   You need to pick up the version from somewhere
before you even know which one to run.

> Here's what FileZilla does for example:
>     http://svn.filezilla-project.org/filezilla/FileZilla3/trunk/configure.ac?view=markup
> 
>     if echo "`$WX_CONFIG_WITH_ARGS --basename`" | grep -i gtk2 >
> /dev/null 2>&1; then
>       PKG_CHECK_MODULES(LIBGTK, gtk+-2.0,, [
>         AC_MSG_ERROR([gtk+-2.0 was not found ...])
>       ])
>     fi
>     if echo "`$WX_CONFIG_WITH_ARGS --basename`" | grep -i gtk3 >
> /dev/null 2>&1; then
>       PKG_CHECK_MODULES(LIBGTK, gtk+-3.0,, [
>         AC_MSG_ERROR([gtk+-3.0 was not found ...])
>       ])
>     fi

So what happens if both are installed?

> > I suppose we can add configuration options --with-gtk={ gtk2 | gtk3 }
> 
> No, please don't. The user has zero influence on that and that is only
> going to lead into problems. Gnuplot should automatically determine
> whether wxWidgets are using GTK and if so, which version. wx-config
> --basename return wx_gtk2* or wx_gtk3* ("*" can be different endings
> based on other characteristics of the installation).

There's your chicken.

> > but that won't make the gtk3 build actually work, because we already
> > know it doesn't report the correct set of libraries that are needed.
> 
> The problem above is unrelated. Adding extra flags is slightly
> different that preventing the user to even compile gnuplot (by adding
> incompatible flags).
> 
> 
> >> > 1037c1037,1038
> >> > <     if expr ${WXWIDGETS_VERSION} \> 2.8 >/dev/null; then
> >> > ---
> >> >>     if expr ${WXWIDGETS_VERSION} \> 2.8 >/dev/null && \
> >> >>       ${WX_CONFIG} --basename | grep 'wx_gtk' >/dev/null 2>&1; then
> >>
> >> Yes, checking for wx_gtk should help, even though I believe that some
> >> package (either gtk or wxwidgets) should suggest the proper flag.
> >
> > But that is exactly the problem!
> 
> I'm not saying that this is ideal. Just saying that this is better
> than the current situation where you add X11 unconditionally; it would
> help to eliminate problems at least in the cases where wxWidgets is
> not even based on GTK.
> 
> (But then again it is probably a lot easier to add compiler flags than
> to remove them.)
> 
> > Yes, gtk and/or wxWidgets should declare what support libraries are
> > required.  That is what `wx-config --libs`   is supposed to do.
> > But it doesn't.
> 
> I would ask the wxWidgets developers for advice.
> 
> Mojca