Re: Can't compile Dillo 3.0.3

On Sat, May 18, 2013 at 09:59:18PM +0200, Sebastian Geerken wrote:
> On Sat, May 18, Johannes Hofmann wrote:
> > On Sat, May 18, 2013 at 08:23:34PM +0200, Sebastian Geerken wrote:
> > > On Sat, May 18, Johannes Hofmann wrote:
> > > > On Sat, May 18, 2013 at 02:47:56PM +0200, Sebastian Geerken wrote:
> > > > > [...]
> > > > > 
> > > > > X11 is needed in src/xembed.cc. It seems that on most systems it is
> > > > > linked indirectly, (src/dillo -> libfltk.so -> libX11.so), on others
> > > > > not, so that an additional "-lX11" is necessary. Should we add it
> > > > > generally? It does not harm; we have only to care about other systems
> > > > > than X11.
> > > > 
> > > > Could we check for libX11 in configure and link explicitely against
> > > > it if available but not fail otherwise?
> > > > That way dillo should still compile on OSX.
> > > 
> > > I thought of this. The code is included in "#ifdef X_PROTOCOL", so
> > > making "-lX11" depend on this X_PROTOCOL should be save; however, I've
> > > not found where X_PROTOCOL is defined.
> > 
> > That comes from the fltk headers depending on whether fltk was built
> > with X11 backend or not.
> 
> Do not find it, strange.

Sorry, it's not in the fltk headers, but via fltk headers. It's
defined in X11/X.h.

> 
> > I don't see how we could get that information at configure time.
> > Maybe some fltk-config option?
> 
> See attached patch for an incomplete implementation. On my system, it
> says "checking whether to link to X11... yes", on OSX it should say
> "... no".
> 
> Unfortunately, AC_RUN_IFELSE is incompatible with cross compiling.
> Perhaps, something with AC_COMPILE_IFELSE could also work.
> 
> Sebastian
> 

> diff -r 2a024fd43fe8 configure.ac
> --- a/configure.ac	Sat May 18 21:27:59 2013 +0200
> +++ b/configure.ac	Sat May 18 21:58:45 2013 +0200
> @@ -124,6 +124,28 @@
>           AC_MSG_ERROR(FLTK 1.3 required; fltk-config not found)
>  esac
>  
> +dnl -----------------------------------
> +dnl Test for X11 (only on some systems)
> +dnl -----------------------------------
> +AC_MSG_CHECKING([whether to link to X11])
> +AC_LANG_PUSH([C++])
> +old_libs=$LIBS
> +old_cxxflags=$CXXFLAGS
> +LIBS=$LIBFLTK_LIBS
> +CXXFLAGS=$LIBFLTK_CXXFLAGS
> +AC_RUN_IFELSE([AC_LANG_PROGRAM([[
> +#define FL_INTERNALS
> +#include <FL/x.H>
> +]],[[
> +#ifdef X_PROTOCOL
> +   return 0;
> +#else
> +   return 1;
> +#endif
> +]])], [AC_MSG_RESULT(yes)] ,[AC_MSG_RESULT(no)])
> +CXXFLAGS=$old_cxxflags
> +LIBS=$old_libs
> +AC_LANG_POP([C++])
>  
>  dnl ----------------
>  dnl Test for libjpeg

Ah that's cool. It's good to base the decision for linking and the
ifdef in the code on the same thing.
I can test it on OSX on tuesday.

  Johannes