m4 macro for boost

[gelbeiche]

Hi,
I try to integrate the boost libs (http://www.boost.org) in 
a C++ project which uses GNU build tools (autoconf/automake).
Unfortunately boost does not support an official m4 macro for
the libs(BTW, the boost people use bjam to build their libs).
I wrote my own macro but I'm a newbie so I would be glad if someone
could give some advice how to improve it. 
The boost lib itself is very cool ;-) so I wonder if someone has
already a solution.
I tested the macro under Linux(SuSE distr.) and cygwin.
I'm happy about every useful comment and I would like to extend it.
Here it is:

AC_DEFUN([AX_PATH_BOOST], 
[
        AC_ARG_WITH([boost], 
                        AC_HELP_STRING([--with-boost=DIR], 
                                                   [use boost (default is NO) , 
specify the root directory for boost library (optional)]), [
                if test "$withval" = "no"; then 
                        want_boost="no"
                elif test "$withval" = "yes"; then
                        want_boost="yes"        
                        ac_boost_path=""
                else
                        want_boost="yes"        
                        ac_boost_path="$withval"
                fi
        ],[want_boost="no"])

        if test "x$want_boost" = "xyes"; then
                boost_lib_version_req=ifelse([$1], ,1.20.0,$1)
                boost_lib_version_req_shorten=`expr $boost_lib_version_req : 
'\([[0-9]]*\.[[0-9]]*\)'`
                boost_lib_version_req_major=`expr $boost_lib_version_req : 
'\([[0-9]]*\)'`
                boost_lib_version_req_minor=`expr $boost_lib_version_req : 
'[[0-9]]*\.\([[0-9]]*\)'`
                boost_lib_version_req_sub_minor=`expr $boost_lib_version_req : 
'[[0-9]]*\.[[0-9]]*\.\([[0-9]]*\)'`
                if test "x$boost_lib_version_req_sub_minor" = "x" ; then 
                        boost_lib_version_req_sub_minor="0"     
        fi
                WANT_BOOST_VERSION=`expr $boost_lib_version_req_major \* 100000 
\+  $boost_lib_version_req_minor \* 100 \+ $boost_lib_version_req_sub_minor`
                AC_MSG_CHECKING(for boostlib >= $boost_lib_version_req)
                succeeded=no

                dnl first we check the system location for boost libraries
                dnl this location ist chosen if boost libraries are installed 
with the --layout=system option
                dnl or if you install boost with RPM
                if test "$ac_boost_path" != ""; then    
                        BOOST_LDFLAGS="-L$ac_boost_path/lib"    
                        BOOST_CPPFLAGS="-I$ac_boost_path/include"
                else
                        for ac_boost_path_tmp in /usr /usr/local /opt ; do
                                if test -d "$ac_boost_path_tmp/include/boost" 
&& test -r "$ac_boost_path_tmp/include/boost"; then
                                        
BOOST_LDFLAGS="-L$ac_boost_path_tmp/lib"        
                                        
BOOST_CPPFLAGS="-I$ac_boost_path_tmp/include"
                                        break;
                                fi
                        done
        
                fi
                CPPFLAGS_SAVED="$CPPFLAGS"
                CPPFLAGS="$CPPFLAGS $BOOST_CPPFLAGS"
                export CPPFLAGS
                
                LDFLAGS_SAVED="$LDFLAGS"
                LDFLAGS="$LDFLAGS $BOOST_LDFLAGS"
                export LDFLAGS

        AC_TRY_COMPILE(
        [
#include <boost/version.hpp>
],
       [
#if BOOST_VERSION >= $WANT_BOOST_VERSION
// Everything is okay
#else
#  error Boost version is too old
#endif

                ],
        [
         AC_MSG_RESULT(yes ($_version))
                 succeeded=yes  
                 found_system=yes
         ifelse([$2], , :, [$2])
       ],
       [
       ])

                dnl if we found no boost with system layout we search for boost 
libraries
                dnl built and installed without the --layout=system option or 
for a staged(not installed) version
                
                if test "x$succeeded" != "xyes"; then
                        _version=0      
                        if test "$ac_boost_path" != ""; then    
                                BOOST_LDFLAGS="-L$ac_boost_path/lib"    
                                if test -d "$ac_boost_path" && test -r 
"$ac_boost_path"; then
                                        for i in `ls -d 
$ac_boost_path/include/boost-* 2>/dev/null`; do
                                                _version_tmp=`echo $i | sed 
"s#$ac_boost_path##" | sed 's/\/include\/boost-//' | sed 's/_/./'`
                                                V_CHECK=`expr $_version_tmp \> 
$_version`
                                                if test "$V_CHECK" = "1" ; then
                                                        _version=$_version_tmp
                                                fi
                                                VERSION_UNDERSCORE=`echo 
$_version | sed 's/\./_/'`
                                                
BOOST_CPPFLAGS="-I$ac_boost_path/include/boost-$VERSION_UNDERSCORE"
                                        done
                                fi
                        else
                                for ac_boost_path in /usr /usr/local /opt ; do
                                        if test -d "$ac_boost_path" && test -r 
"$ac_boost_path"; then
                                                for i in `ls -d 
$ac_boost_path/include/boost-* 2>/dev/null`; do
                                                        _version_tmp=`echo $i | 
sed "s#$ac_boost_path##" | sed 's/\/include\/boost-//' | sed 's/_/./'`
                                                        V_CHECK=`expr 
$_version_tmp \> $_version`
                                                        if test "$V_CHECK" = 
"1" ; then
                                                                
_version=$_version_tmp
                                                                
best_path=$ac_boost_path
                                                        fi      
                                                done
                                        fi
                                done

                                VERSION_UNDERSCORE=`echo $_version | sed 
's/\./_/'`
                                
BOOST_CPPFLAGS="-I$best_path/include/boost-$VERSION_UNDERSCORE"
                                BOOST_LDFLAGS="-L$best_path/lib"

                        if test "x$BOOST_ROOT" != "x"; then
                                        if test -d "$BOOST_ROOT" && test -r 
"$BOOST_ROOT"; then
                                                version_dir=`expr //$BOOST_ROOT 
: '.*/\(.*\)'`
                                                stage_version=`echo 
$version_dir | sed 's/boost_//' | sed 's/_/./g'`
                                                stage_version_shorten=`expr 
$stage_version : '\([[0-9]]*\.[[0-9]]*\)'`
                                                V_CHECK=`expr 
$stage_version_shorten \>\= $_version`    
                                                if test "$V_CHECK" = "1" ; then
                                                        AC_MSG_NOTICE(We will 
use a staged boost library from $BOOST_ROOT)
                                                        
BOOST_CPPFLAGS="-I$BOOST_ROOT"
                                                        
BOOST_LDFLAGS="-L$BOOST_ROOT/stage/lib"
                                                fi
                                        fi
                        fi
                        fi

                        CPPFLAGS="$CPPFLAGS $BOOST_CPPFLAGS"
                        export CPPFLAGS
                        LDFLAGS="$LDFLAGS $BOOST_LDFLAGS"
                        export LDFLAGS

                AC_TRY_COMPILE(
                [
#include <boost/version.hpp>
],
       [
#if BOOST_VERSION >= $WANT_BOOST_VERSION
// Everything is okay
#else
#  error Boost version is too old
#endif

                ],
        [
         AC_MSG_RESULT(yes ($_version))
                 succeeded=yes  
         ifelse([$2], , :, [$2])
       ],
       [
         AC_MSG_RESULT(no ($_version))
         ifelse([$3], , :, [$3])
       ])
                fi

                if test "$succeeded" != "yes" ; then
                        if test "$_version" = "0" ; then
                                AC_MSG_ERROR('We could not detect the boost 
libraries.
                        If you have a staged boost library (still not 
installed) 
                        please specify \$BOOST_ROOT in your environment and do 
not 
                        give a PATH to --with-boost option')
                        else
                                AC_MSG_ERROR('Your boost libraries seems to old 
(version $_version). 
                           We need at least $boost_lib_version_shorten')        
                        fi
                else
                        AC_MSG_NOTICE(BOOST_CPPFLAGS: $BOOST_CPPFLAGS)
                        AC_MSG_NOTICE(BOOST_LDFLAGS: $BOOST_LDFLAGS)
                        AC_SUBST(BOOST_CPPFLAGS)        
                        AC_SUBST(BOOST_LDFLAGS)         
                        AC_DEFINE(HAVE_BOOST,,[define if the Boost library is 
available])

                        AC_CACHE_CHECK(whether the Boost::Filesystem library is 
available,
                                                   ax_cv_boost_filesystem,
                                                [AC_LANG_SAVE
                         AC_LANG_CPLUSPLUS
                         AC_COMPILE_IFELSE(AC_LANG_PROGRAM([[#include 
<boost/filesystem/path.hpp>]],
                                   [[using namespace boost::filesystem;
                                   path my_path( "foo/bar/data.txt" );
                                   return 0;]]),
                                               ax_cv_boost_filesystem=yes, 
ax_cv_boost_filesystem=no)
                                                                AC_LANG_RESTORE
                        ])
                        if test "$ax_cv_boost_filesystem" = "yes"; then
                                AC_DEFINE(HAVE_BOOST_FILESYSTEM,,[define if the 
Boost::FILESYSTEM library is available])
                                for ax_lib in boost_filesystem 
boost_filesystem-$CC boost_filesystem-$CC-mt boost_filesystem-$CC-mt-s ; do
                                    AC_CHECK_LIB($ax_lib, main, 
[BOOST_FILESYSTEM_LIB="-l$ax_lib" AC_SUBST(BOOST_FILESYSTEM_LIB) 
link_filesystem="yes" break], [link_filesystem="no"])
                                done
                                if test "x$link_filesystem" = "xno"; then
                                        AC_MSG_NOTICE(Could not link against 
$ax_lib !)
                                fi
                        fi

                        AC_CACHE_CHECK(whether the Boost::Program_Options 
library is available,
                                                   ax_cv_boost_program_options,
                                                [AC_LANG_SAVE
                         AC_LANG_CPLUSPLUS
                         AC_COMPILE_IFELSE(AC_LANG_PROGRAM([[#include 
<boost/program_options.hpp>]],
                                   
[[boost::program_options::options_description generic("Generic options");
                                   return 0;]]),
                   ax_cv_boost_program_options=yes, 
ax_cv_boost_program_options=no)
                         AC_LANG_RESTORE
                        ])
                        if test "$ax_cv_boost_program_options" = yes; then
                                AC_DEFINE(HAVE_BOOST_PROGRAM_OPTIONS,,[define 
if the Boost::PROGRAM_OPTIONS library is available])
                                for ax_lib in boost_program_options 
boost_program_options-$CC boost_program_options-$CC-mt 
boost_program_options-$CC-mt-s ; do
                                    AC_CHECK_LIB($ax_lib, main, 
[BOOST_PROGRAM_OPTIONS_LIB="-l$ax_lib" AC_SUBST(BOOST_PROGRAM_OPTIONS_LIB) 
link_program_options="yes" break], [link_program_options="no"])
                                done
                                if test "x$link_program_options="no"" = "xno"; 
then
                                        AC_MSG_NOTICE(Could not link against 
$ax_lib !)
                                fi
                        fi

                fi
        fi
])