[pygobject] use improved python.m4 macros to search for Python headers and libs

[Dieter Verfaillie <dieterv src gnome org>]

commit 4671f5397003f376f00830e3fd1c214de594619f
Author: Dieter Verfaillie <dieterv optionexplicit be>
Date:   Fri Sep 9 14:55:01 2011 +0200

    use improved python.m4 macros to search for Python headers and libs
    
    https://bugzilla.gnome.org/show_bug.cgi?id=658652

 configure.ac |    3 ++-
 m4/python.m4 |   47 +++++++++++++++++++++++++++++++++++++----------
 2 files changed, 39 insertions(+), 11 deletions(-)
---
diff --git a/configure.ac b/configure.ac
index b50a3b1..b589a3f 100644
--- a/configure.ac
+++ b/configure.ac
@@ -101,7 +101,8 @@ if test $build_py3k = true ; then
 			  [AC_MSG_ERROR(too old)])
 fi
 
-AM_CHECK_PYTHON_HEADERS(,[AC_MSG_ERROR(could not find Python headers)])
+AM_CHECK_PYTHON_HEADERS(, AC_MSG_ERROR([Python headers not found]))
+AM_CHECK_PYTHON_LIBS(, AC_MSG_ERROR([Python libs not found]))
 
 AC_MSG_CHECKING([for PySignal_SetWakeupFd in Python.h])
 old_CPPFLAGS=$CPPFLAGS
diff --git a/m4/python.m4 b/m4/python.m4
index 523e45a..968b9a6 100644
--- a/m4/python.m4
+++ b/m4/python.m4
@@ -43,16 +43,18 @@ AC_DEFUN([AM_CHECK_PYTHON_HEADERS],
 [AC_REQUIRE([AM_PATH_PYTHON])
 AC_MSG_CHECKING(for headers required to compile python extensions)
 dnl deduce PYTHON_INCLUDES
-py_prefix=`$PYTHON -c "import sys; sys.stdout.write(sys.prefix)"`
-py_exec_prefix=`$PYTHON -c "import sys; sys.stdout.write(sys.exec_prefix)"`
-PYTHON_CONFIG=`which $PYTHON`-config
-if test -x "$PYTHON_CONFIG"; then
-PYTHON_INCLUDES=`$PYTHON_CONFIG --includes 2>/dev/null`
-else
-PYTHON_INCLUDES="-I${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
+if test "x$PYTHON_INCLUDES" == x; then
+  PYTHON_CONFIG=`which $PYTHON`-config
+  if test -x "$PYTHON_CONFIG"; then
+    PYTHON_INCLUDES=`$PYTHON_CONFIG --includes 2>/dev/null`
+  else
+    py_prefix=`$PYTHON -c "import sys; sys.stdout.write(sys.prefix)"`
+    py_exec_prefix=`$PYTHON -c "import sys; sys.stdout.write(sys.exec_prefix)"`
+    PYTHON_INCLUDES="-I${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
+  fi
 fi
 AC_SUBST(PYTHON_INCLUDES)
 dnl check if the headers exist:
@@ -66,6 +68,31 @@ $2])
 CPPFLAGS="$save_CPPFLAGS"
 ])
 
+dnl a macro to check for ability to embed python
+dnl  AM_CHECK_PYTHON_LIBS([ACTION-IF-POSSIBLE], [ACTION-IF-NOT-POSSIBLE])
+dnl function also defines PYTHON_LIBS
+AC_DEFUN([AM_CHECK_PYTHON_LIBS],
+[AC_REQUIRE([AM_CHECK_PYTHON_HEADERS])
+AC_MSG_CHECKING(for libraries required to embed python)
+dnl deduce PYTHON_LIBS
+py_exec_prefix=`$PYTHON -c "import sys; print sys.exec_prefix"`
+if test "x$PYTHON_LIBS" == x; then
+	PYTHON_LIBS="-L${py_prefix}/lib -lpython${PYTHON_VERSION}"
+fi
+if test "x$PYTHON_LIB_LOC" == x; then
+	PYTHON_LIB_LOC="${py_prefix}/lib"
+fi
+AC_SUBST(PYTHON_LIBS)
+AC_SUBST(PYTHON_LIB_LOC)
+dnl check if the headers exist:
+save_LIBS="$LIBS"
+LIBS="$LIBS $PYTHON_LIBS"
+AC_TRY_LINK_FUNC(Py_Initialize, dnl
+         [LIBS="$save_LIBS"; AC_MSG_RESULT(yes); $1], dnl
+         [LIBS="$save_LIBS"; AC_MSG_RESULT(no); $2])
+
+])
+
 # JD_PYTHON_CHECK_VERSION(PROG, VERSION, [ACTION-IF-TRUE], [ACTION-IF-FALSE])
 # ---------------------------------------------------------------------------
 # Run ACTION-IF-TRUE if the Python interpreter PROG has version >= VERSION.