build problems with wxGTK 3.0

[Mojca M. <moj...@gm...>]

On Thu, Jun 19, 2014 at 10:05 AM, Jun T. wrote:
> On 2014/06/17, at 4:43, Ethan A Merritt wrote:
>> So I have changed gnuplot's autoconfigure script to add -lX11
>> itself if it sees that the newer wxWidgets is being used.
>
> This causes a problem on my Mac (and maybe on other systems);
> the linker dies saying "-lX11 can't be found".
> (OS X 10.8 / no X11 installed / wxWidgets=svn HEAD)

Confirmed. You shouldn't unconditionally link to X11 (in particular
not on Mac). The check for wx_gtk should be better, but then again gtk
also works with quartz on OS X. Honestly I don't expect people to use
wxGTK 3.0 with quartz on Macs when they can use Cocoa (unless maybe
with wxGTK 2.8 to get support for old software that hasn't been ported
to 3.0, but then again wxWidgets 2.8 won't work with GTK/quartz
without quite a bit of patching).

I wanted to test gnuplot with wxGTK 3.0 on Mac, but it didn't work at
all because I have it linked against gtk 3.0 and gnuplot fails because
it has a fixed idea that wxGTK is using GTK+ 2:

if test "${enable_wxwidgets_ok}" = yes ; then
  WX_CXXFLAGS="`$WX_CONFIG --cxxflags | sed 's/-fno-exceptions//'`
$CAIROPANGO_CFLAGS"
  WX_LIBS="`$WX_CONFIG --libs` $CAIROPANGO_LIBS"

  dnl Check for fork(), used for the 'persist' effect
  AC_FUNC_FORK

  dnl Check for gtk (raise/lower tweaks)
  PKG_CHECK_MODULES(GTK, [gtk+-2.0], have_gtk=yes, have_gtk=no)
  if  test "${have_gtk}" = yes ; then
    AC_DEFINE(HAVE_GTK, 1, [Define to use gtk/gdk tweaks])
    WX_CXXFLAGS="$WX_CXXFLAGS $GTK_CFLAGS"
    WX_LIBS="$WX_LIBS $GTK_LIBS"
  fi

  dnl The user can force single-threaded mode
  AC_ARG_WITH(wx-single-threaded, dnl
  [--with-wx-single-threaded   do not use multithreaded wxgtk even if
available],
  WX_CXXFLAGS="$WX_CXXFLAGS -DWXT_MONOTHREADED",~
  )

  dnl Check for gtk>2.8 for direct rendering to screen
  PKG_CHECK_MODULES(GTK28, [gtk+-2.0 >= 2.8.0], have_gtk28=yes, have_gtk28=no)
  if  test "${have_gtk28}" = yes ; then
    AC_DEFINE(HAVE_GTK28, 1, [Define to use gtk+ functions to handle cairo])
  fi


and then the build fails with

In file included from ../../src/wxterminal/wxt_gui.cpp:97:
In file included from ../../src/wxterminal/wxt_gui.h:183:
In file included from /opt/local/include/gtk-2.0/gdk/gdk.h:32:
In file included from /opt/local/include/gtk-2.0/gdk/gdkapplaunchcontext.h:31:
In file included from /opt/local/include/gtk-2.0/gdk/gdkscreen.h:32:
/opt/local/include/gtk-2.0/gdk/gdktypes.h:114:39: error: typedef
redefinition with different types ('struct _GdkDrawable' vs 'struct
_GdkWindow')
typedef struct _GdkDrawable           GdkWindow;
                                      ^
/path/to/wxGTK/3.0/include/wx-3.0/wx/defs.h:3412:31: note: previous
definition is here
    typedef struct _GdkWindow GdkWindow;
                              ^
1 error generated.


So please also check whether wxWidgets are using gtk2 or gtk3 before
calling pkg-config to supply build flags.

> The following may be a possible fix, but not tested at all on Linux.
>
>
> Index: configure.in
> ===================================================================
> RCS file: /cvsroot/gnuplot/gnuplot/configure.in,v
> retrieving revision 1.368
> diff -r1.368 configure.in
> 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.

Mojca