perf tools: Add support to install perf python extension

Adding install-python_ext target to install python extension related
files.  Installation directory is governed by python distutils package
and follows the DESTDIR variable settings.

Also moving python extension build output into '$(O)python_ext_build'
directory and making it configurable via PYTHON_EXTBUILD variable.

Keeping the '$(O)python/perf.so' file, so it could be used for testing
as of until now.

Cc: Ingo Molnar <mingo@elte.hu>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/20110722113307.GA1931@jolsa.brq.redhat.com
Signed-off-by: Jiri Olsa <jolsa@redhat.com>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

tools/perf/util/setup.py

@@ -3,9 +3,27 @@
 from distutils.core import setup, Extension
 from os import getenv
 
+from distutils.command.build_ext   import build_ext   as _build_ext
+from distutils.command.install_lib import install_lib as _install_lib
+
+class build_ext(_build_ext):
+    def finalize_options(self):
+        _build_ext.finalize_options(self)
+        self.build_lib  = build_lib
+        self.build_temp = build_tmp
+
+class install_lib(_install_lib):
+    def finalize_options(self):
+        _install_lib.finalize_options(self)
+        self.build_dir = build_lib
+
+
 cflags = ['-fno-strict-aliasing', '-Wno-write-strings']
 cflags += getenv('CFLAGS', '').split()
 
+build_lib = getenv('PYTHON_EXTBUILD_LIB')
+build_tmp = getenv('PYTHON_EXTBUILD_TMP')
+
 perf = Extension('perf',
 		  sources = ['util/python.c', 'util/ctype.c', 'util/evlist.c',
 			     'util/evsel.c', 'util/cpumap.c', 'util/thread_map.c',
@@ -21,4 +39,5 @@ setup(name='perf',
       author_email='acme@redhat.com',
       license='GPLv2',
       url='http://perf.wiki.kernel.org',
-      ext_modules=[perf])
+      ext_modules=[perf],
+      cmdclass={'build_ext': build_ext, 'install_lib': install_lib})