ac_prog_javah

AC_PROG_JAVAH tests the availability of the javah header generator and looks for the jni.h header file. If available, JAVAH is set to the full path of javah and CPPFLAGS is updated accordingly.

AC_DEFUN([AC_PROG_JAVAH],[
AC_REQUIRE([AC_CANONICAL_SYSTEM])dnl
AC_REQUIRE([AC_PROG_CPP])dnl
AC_PATH_PROG(JAVAH,javah)
if test x"`eval 'echo $ac_cv_path_JAVAH'`" != x ; then
  AC_TRY_CPP([#include <jni.h>],,[
    ac_save_CPPFLAGS="$CPPFLAGS"
changequote(, )dnl
    ac_dir=`echo $ac_cv_path_JAVAH | sed 's,\(.*\)/[^/]*/[^/]*$,\1/include,'`
    ac_machdep=`echo $build_os | sed 's,[-0-9].*,,' | sed 's,cygwin,win32,'`
changequote([, ])dnl
    CPPFLAGS="$ac_save_CPPFLAGS -I$ac_dir -I$ac_dir/$ac_machdep"
    AC_TRY_CPP([#include <jni.h>],
               ac_save_CPPFLAGS="$CPPFLAGS",
               AC_MSG_WARN([unable to include <jni.h>]))
    CPPFLAGS="$ac_save_CPPFLAGS"])
fi])