##### http://autoconf-archive.cryp.to/ac_jni_include_dir.html
#
# SYNOPSIS
#
#   AC_JNI_INCLUDE_DIR
#
# DESCRIPTION
#
#   AC_JNI_INCLUDE_DIR finds include directories needed for compiling
#   programs using the JNI interface.
#
#   JNI include directories are usually in the java distribution This
#   is deduced from the value of JAVAC. When this macro completes, a
#   list of directories is left in the variable JNI_INCLUDE_DIRS.
#
#   Example usage follows:
#
#       AC_JNI_INCLUDE_DIR
#
#       for JNI_INCLUDE_DIR in $JNI_INCLUDE_DIRS
#       do
#               CPPFLAGS="$CPPFLAGS -I$JNI_INCLUDE_DIR"
#       done
#
#   If you want to force a specific compiler:
#
#   - at the configure.in level, set JAVAC=yourcompiler before calling
#   AC_JNI_INCLUDE_DIR
#
#   - at the configure level, setenv JAVAC
#
#   Note: This macro can work with the autoconf M4 macros for Java
#   programs. This particular macro is not part of the original set of
#   macros.
#
# LAST MODIFICATION
#
#   2006-05-27
#
# COPYLEFT
#
#   Copyright (c) 2006 Don Anderson <dda@sleepycat.com>
#
#   Copying and distribution of this file, with or without
#   modification, are permitted in any medium without royalty provided
#   the copyright notice and this notice are preserved.

AC_DEFUN([AC_JNI_INCLUDE_DIR],[

JNI_INCLUDE_DIRS=""

test "x$JAVAC" = x && AC_MSG_ERROR(['\$JAVAC' undefined])
AC_PATH_PROG(_ACJNI_JAVAC, $JAVAC, no)
test "x$_ACJNI_JAVAC" = xno && AC_MSG_ERROR([$JAVAC could not be found in path])

_ACJNI_FOLLOW_SYMLINKS("$_ACJNI_JAVAC")
_JTOPDIR=`echo "$_ACJNI_FOLLOWED" | sed -e 's://*:/:g' -e 's:/[[^/]]*$::'`
case "$host_os" in
        darwin*)        _JTOPDIR=`echo "$_JTOPDIR" | sed -e 's:/[[^/]]*$::'`
                        _JINC="$_JTOPDIR/Headers";;
        *)              _JINC="$_JTOPDIR/include";;
esac
if test -f "$_JINC/jni.h"; then
        JNI_INCLUDE_DIRS="$JNI_INCLUDE_DIRS $_JINC"
else
        _JTOPDIR=`echo "$_JTOPDIR" | sed -e 's:/[[^/]]*$::'`
        if test -f "$_JTOPDIR/include/jni.h"; then
                JNI_INCLUDE_DIRS="$JNI_INCLUDE_DIRS $_JTOPDIR/include"
        else
                AC_MSG_ERROR([cannot find java include files])
        fi
fi

# get the likely subdirectories for system specific java includes
case "$host_os" in
bsdi*)          _JNI_INC_SUBDIRS="bsdos";;
linux*)         _JNI_INC_SUBDIRS="linux genunix";;
osf*)           _JNI_INC_SUBDIRS="alpha";;
solaris*)       _JNI_INC_SUBDIRS="solaris";;
mingw*)			_JNI_INC_SUBDIRS="win32";;
cygwin*)		_JNI_INC_SUBDIRS="win32";;
*)              _JNI_INC_SUBDIRS="genunix";;
esac

# add any subdirectories that are present
for JINCSUBDIR in $_JNI_INC_SUBDIRS
do
        if test -d "$_JTOPDIR/include/$JINCSUBDIR"; then
                JNI_INCLUDE_DIRS="$JNI_INCLUDE_DIRS $_JTOPDIR/include/$JINCSUBDIR"
        fi
done
])

# _ACJNI_FOLLOW_SYMLINKS <path>
# Follows symbolic links on <path>,
# finally setting variable _ACJNI_FOLLOWED
# --------------------
AC_DEFUN([_ACJNI_FOLLOW_SYMLINKS],[
# find the include directory relative to the javac executable
_cur="$1"
while ls -ld "$_cur" 2>/dev/null | grep " -> " >/dev/null; do
        AC_MSG_CHECKING(symlink for $_cur)
        _slink=`ls -ld "$_cur" | sed 's/.* -> //'`
        case "$_slink" in
        /*) _cur="$_slink";;
        # 'X' avoids triggering unwanted echo options.
        *) _cur=`echo "X$_cur" | sed -e 's/^X//' -e 's:[[^/]]*$::'`"$_slink";;
        esac
        AC_MSG_RESULT($_cur)
done
_ACJNI_FOLLOWED="$_cur"
])# _ACJNI