Re: [Tuxmath-devel] tuxmath fails to compile without sdlttf

[David B. <dav...@gm...>]

Hi Tasos,

On Tue, Feb 8, 2011 at 7:29 AM, Tasos Latsas <tla...@gm...> wrote:
> Hello,
> I created pkgbuilds for the Archlinux distribution, for tuxmath [1] and
> t4k_common [2].
> t4k_common compiles fine but tuxmath fails with:
> /usr/bin/ld: cannot find -lSDL_ttf
>
> I have sdl_pango installed, I thought that it will use sdl_pango if
> present and if not then fallback to sdl_ttf. (correct me if I am wrong)

Yes, that's how it is supposed to work, and how it does work at run
time, but it looks like we are requiring SDL_ttf in the build even
though it doesn't actually get used.

> If I explicitly install sdl_ttf then tuxmath compiles and works fine but
> i can't see any links to sdl_ttf using ldd.

I think the problem is in t4k_common's pkg-config file,
t4k_common.pc.in (reproduced below).  My knowledge of pkg-config is
limited, but looking at the file it's pretty clear that I hard-coded a
dependency on SDL_ttf into the "Libs" section.   t4k_common's build
process can detect if SDL_Pango is available, but the problem comes in
with the static linking needed for the mingw-cross-env build.  For
static linking, t4k_common needs to supply all the compiler arguments
for all the dependencies, and this only works "automagically" for
dependencies that themselves have pkg-config *.pc files.  I haven't
figured out how to write a *.pc file that conditionally passes the
arguments for either SDL_Pango (plus its deps) or SDL_ttf (plus deps)
to the tuxmath linking step.  Have I confused everyone yet?

If anyone else on this list is proficient with pkg-config, help would
be appreciated.

I'm cc'ing Volker Grabsch (mingw-cross-env maintainer) in case this
issue has come up in static linking for other mingw-cross-env
packages, and because Volker seems to know this stuff really, really
well.

David Bruce



t4kcommon/t4k_common.pc.in:   --------------------------------------------------

prefix=@prefix@
exec_prefix=@exec_prefix@
libdir=@libdir@
includedir=@includedir@

Name: @PACKAGE_NAME@
Description: Tux4Kids common routines
Version: @VERSION@

# AFAICT we can only list libs with .pc files in "Requires:"
Requires: sdl >= 1.2.0 SDL_image SDL_Pango librsvg-2.0 libxml-2.0
# List libs "by hand" that don't have .pc files:
Libs: -l@PACKAGE_TARNAME@ -L${libdir} -lSDL_mixer -lSDL_ttf -lSDL_net
Cflags: -I${includedir}

# Because SDL_mixer and SDL_ttf do not have .pc files on some platforms,
# we list their static dependencies here:

Libs.private: -mwindows -L/opt/mingw-cross-env/usr/i686-pc-mingw32/lib
-lmikmod -lsmpeg -lstdc++ -lmingw32 -lSDLmain -liconv -luser32 -lgdi32
-lwinmm -ldxguid -lSDL -lpthread -lvorbisfile -lvorbis -lm -logg
-lfreetype