dnl From msw.
dnl
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_INCLUDES
AC_DEFUN([AM_CHECK_PYTHON_HEADERS],
[AC_REQUIRE([AM_PATH_PYTHON])
AC_MSG_CHECKING(for headers required to compile python extensions)
dnl deduce PYTHON_INCLUDES
py_prefix=`$PYTHON -c "import sys; print sys.prefix"`
py_exec_prefix=`$PYTHON -c "import sys; print sys.exec_prefix"`
PYTHON_INCLUDES="-I${py_prefix}/include/python${PYTHON_VERSION}"
if test "$py_prefix" != "$py_exec_prefix"; then
  PYTHON_INCLUDES="$PYTHON_INCLUDES -I${py_exec_prefix}/include/python${PYTHON_VERSION}"
fi
AC_SUBST(PYTHON_INCLUDES)
dnl check if the headers exist:
save_CPPFLAGS="$CPPFLAGS"
CPPFLAGS="$CPPFLAGS $PYTHON_INCLUDES"
AC_TRY_CPP([#include <Python.h>],dnl
[AC_MSG_RESULT(found)
$1],dnl
[AC_MSG_RESULT(not found)
$2])
CPPFLAGS="$save_CPPFLAGS"
])

dnl From ac-archive.
dnl
dnl @synopsis AC_CHECK_CC_OPT(flag, cachevarname)
dnl 
dnl AC_CHECK_CC_OPT(-fvomit-frame,vomitframe)
dnl would show a message as like 
dnl "checking wether gcc accepts -fvomit-frame ... no"
dnl and sets the shell-variable $vomitframe to either "-fvomit-frame"
dnl or (in this case) just a simple "". In many cases you would then call 
dnl AC_SUBST(_fvomit_frame_,$vomitframe) to create a substitution that
dnl could be fed as "CFLAGS = @_funsigned_char_@ @_fvomit_frame_@
dnl
dnl in consequence this function is much more general than their 
dnl specific counterparts like ac_cxx_rtti.m4 that will test for
dnl -fno-rtti -fno-exceptions
dnl 
dnl @version $Id$
dml @author  Guido Draheim <guidod@gmx.de>

AC_DEFUN(AC_CHECK_CC_OPT,
[AC_CACHE_CHECK(whether ${CC-cc} accepts [$1], [$2],
[AC_SUBST($2)
echo 'void f(){}' > conftest.c
if test -z "`${CC-cc} -c $1 conftest.c 2>&1`"; then
  $2="$1"
else
  $2=""
fi
rm -f conftest*
])])