Gnulib needed in AC_CHECK_HEADERS

[Sylvain Beucler]

Hi,

I'm cross-compiling an SDL application for i586-mingw32mscv.  I
imported the alloca module from Gnulib, as a dependency of strcasestr.


When checking for SDL.h,

  AC_CHECK_HEADERS(SDL.h SDL_rotozoom.h SDL_framerate.h SDL_image.h,
    [], AC_MSG_ERROR([Could not find necessary SDL libs headers]))

../configure fails checking for SDL.h, because SDL.h (more exactly
SDL_stdinc.h), seeing HAVE_ALLOCA set, tries to include <alloca.h>,
and fails (mingw doesn't have alloca.h).


However at that point the Gnulib include path is not set (the
documentation recommends to do so in Makefile.am, not as early as
configure.ac).


Moreover, I can't find a way to specify $top_srcdir and $top_builddir
in configure.ac, apparently those variables are not available there.

  CPPFLAGS="$CPPFLAGS -I${top_srcdir}/gnulib/lib -I${top_builddir}/gnulib/lib"
  => -I/gnulib/lib -I/gnulib/lib


How would you deal with this?

I can move gl_INIT after AC_CHECK_HEADERS, but it doesn't seem right -
I do have alloca.h now, right? :)

-- 
Sylvain