## this one is commonly used with AM_PATH_PYTHONDIR ...
dnl AM_CHECK_PYMOD(MODNAME [,SYMBOL [,ACTION-IF-FOUND [,ACTION-IF-NOT-FOUND]]])
dnl Check if a module containing a given symbol is visible to python.
AC_DEFUN(AM_CHECK_PYMOD,
[AC_REQUIRE([AM_PATH_PYTHON])
py_mod_var=`echo $1['_']$2 | sed 'y%./+-%__p_%'`
AC_MSG_CHECKING(for ifelse([$2],[],,[$2 in ])python module $1)
AC_CACHE_VAL(py_cv_mod_$py_mod_var, [
ifelse([$2],[], [prog="
import sys
try:
        import $1
except ImportError:
        sys.exit(1)
except:
        sys.exit(0)
sys.exit(0)"], [prog="
import $1
$1.$2"])
if $PYTHON -c "$prog" 1>&AC_FD_CC 2>&AC_FD_CC
  then
    eval "py_cv_mod_$py_mod_var=yes"
  else
    eval "py_cv_mod_$py_mod_var=no"
  fi
])
py_val=`eval "echo \`echo '$py_cv_mod_'$py_mod_var\`"`
if test "x$py_val" != xno; then
  AC_MSG_RESULT(yes)
  ifelse([$3], [],, [$3
])dnl
else
  AC_MSG_RESULT(no)
  ifelse([$4], [],, [$4
])dnl
fi
])

dnl a macro to check for ability to create python extensions
dnl  AM_CHECK_PYTHON_HEADERS([ACTION-IF-POSSIBLE], [ACTION-IF-NOT-POSSIBLE])
dnl function also defines PYTHON_CFLAGS
AC_DEFUN([AM_CHECK_PYTHON_HEADERS],
[AC_REQUIRE([AM_PATH_PYTHON])
AC_MSG_CHECKING(for headers required to compile python extensions)
dnl deduce PYTHON_CFLAGS

if test  "x$PYTHON_CFLAGS" = "x"  ; then
   py_prefix=`$PYTHON -c "import sys; print sys.prefix"`
   py_exec_prefix=`$PYTHON -c "import sys; print sys.exec_prefix"`

   PYTHON_CFLAGS="-I${py_prefix}/include/python${PYTHON_VERSION}"


   if test "$py_prefix" != "$py_exec_prefix"; then
      PYTHON_CFLAGS="$PYTHON_CFLAGS -I${py_exec_prefix}/include/python${PYTHON_VERSION}"
   fi
fi

if test  "x$PYTHON_LIBS" = "x" ; then
   python_link=`$PYTHON -c "import distutils.sysconfig ; print distutils.sysconfig.get_config_var(\"LIBRARY\")" | sed -e "s%lib\(.*\)\.[[a-zA-Z]]*$%-l\1%"`

   python_libdir=`$PYTHON -c "import distutils.sysconfig ; print distutils.sysconfig.get_config_var(\"LIBDIR\")"`

   PYTHON_LIBS="-L${python_libdir} ${python_link}"
fi

AC_SUBST(PYTHON_CFLAGS)
AC_SUBST(PYTHON_LIBS)

dnl check if the headers exist:
save_CPPFLAGS="$CPPFLAGS"
CPPFLAGS="$CPPFLAGS $PYTHON_CFLAGS"
AC_TRY_CPP([#include <Python.h>],dnl
[AC_MSG_RESULT(found)
$1],dnl
[AC_MSG_RESULT(not found)
$2])
CPPFLAGS="$save_CPPFLAGS"
])

dnl
dnl JH_ADD_CFLAG(FLAG)
dnl checks whether the C compiler supports the given flag, and if so, adds
dnl it to $CFLAGS.  If the flag is already present in the list, then the
dnl check is not performed.
AC_DEFUN([JH_ADD_CFLAG],
[
case " $CFLAGS " in
*@<:@\	\ @:>@$1@<:@\	\ @:>@*)
  ;;
*)
  save_CFLAGS="$CFLAGS"
  CFLAGS="$CFLAGS $1"
  AC_MSG_CHECKING([whether [$]CC understands $1])
  AC_TRY_COMPILE([], [], [jh_has_option=yes], [jh_has_option=no])
  AC_MSG_RESULT($jh_has_option)
  if test $jh_has_option = no; then
    CFLAGS="$save_CFLAGS"
  fi
  ;;
esac])

# Check for binary relocation support.
# Written by Hongli Lai
# http://autopackage.org/

AC_DEFUN([AM_BINRELOC],
[
	AC_ARG_ENABLE(binreloc,
		[  --enable-binreloc       compile with binary relocation support
                          (default=enable when available)],
		enable_binreloc=$enableval,enable_binreloc=auto)

	AC_ARG_ENABLE(binreloc-threads,
		[  --enable-binreloc-threads      compile binary relocation with threads support
	                         (default=yes)],
		enable_binreloc_threads=$enableval,enable_binreloc_threads=yes)

	BINRELOC_CFLAGS=
	BINRELOC_LIBS=
	if test "x$enable_binreloc" = "xauto"; then
		AC_CHECK_FILE([/proc/self/maps])
		AC_CACHE_CHECK([whether everything is installed to the same prefix],
			       [br_cv_valid_prefixes], [
				if test "$bindir" = '${exec_prefix}/bin' -a "$sbindir" = '${exec_prefix}/sbin' -a \
					"$datadir" = '${prefix}/share' -a "$libdir" = '${exec_prefix}/lib' -a \
					"$libexecdir" = '${exec_prefix}/libexec' -a "$sysconfdir" = '${prefix}/etc'
				then
					br_cv_valid_prefixes=yes
				else
					br_cv_valid_prefixes=no
				fi
				])
	fi
	AC_CACHE_CHECK([whether binary relocation support should be enabled],
		       [br_cv_binreloc],
		       [if test "x$enable_binreloc" = "xyes"; then
		       	       br_cv_binreloc=yes
		       elif test "x$enable_binreloc" = "xauto"; then
			       if test "x$br_cv_valid_prefixes" = "xyes" -a \
			       	       "x$ac_cv_file__proc_self_maps" = "xyes"; then
				       br_cv_binreloc=yes
			       else
				       br_cv_binreloc=no
			       fi
		       else
			       br_cv_binreloc=no
		       fi])

	if test "x$br_cv_binreloc" = "xyes"; then
		BINRELOC_CFLAGS="-DENABLE_BINRELOC"
		AC_DEFINE(ENABLE_BINRELOC,,[Use binary relocation?])
		if test "x$enable_binreloc_threads" = "xyes"; then
			AC_CHECK_LIB([pthread], [pthread_getspecific])
		fi

		AC_CACHE_CHECK([whether binary relocation should use threads],
			       [br_cv_binreloc_threads],
			       [if test "x$enable_binreloc_threads" = "xyes"; then
					if test "x$ac_cv_lib_pthread_pthread_getspecific" = "xyes"; then
						br_cv_binreloc_threads=yes
					else
						br_cv_binreloc_threads=no
					fi
			        else
					br_cv_binreloc_threads=no
				fi])

		if test "x$br_cv_binreloc_threads" = "xyes"; then
			BINRELOC_LIBS="-lpthread"
			AC_DEFINE(BR_PTHREAD,1,[Include pthread support for binary relocation?])
		else
			BINRELOC_CFLAGS="$BINRELOC_CFLAGS -DBR_PTHREADS=0"
			AC_DEFINE(BR_PTHREAD,0,[Include pthread support for binary relocation?])
		fi
	fi
	AC_SUBST(BINRELOC_CFLAGS)
	AC_SUBST(BINRELOC_LIBS)
])