Do not look at host headers/libraries in cross-compile mode

When we are cross-compiling, setup.py should never look in /usr or
/usr/local to find headers or libraries. A later patch adds a
mechanism to tell setup.py to look in a specific directory for headers
and libraries.

Patch first written by Thomas Petazzoni
<thomas.petazzoni@free-electrons.com> for python2.7, and then ported
to python3.3 by Maxime Ripard <maxime.ripard@free-electrons.com>

Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
---
 setup.py |   23 +++++------------------
 1 file changed, 5 insertions(+), 18 deletions(-)

Index: Python-3.3.0/setup.py
===================================================================
--- Python-3.3.0.orig/setup.py
+++ Python-3.3.0/setup.py
@@ -447,10 +447,8 @@
         if not cross_compiling:
             add_dir_to_list(self.compiler.library_dirs, '/usr/local/lib')
             add_dir_to_list(self.compiler.include_dirs, '/usr/local/include')
-        # only change this for cross builds for 3.3, issues on Mageia
-        if cross_compiling:
             self.add_gcc_paths()
-        self.add_multiarch_paths()
+            self.add_multiarch_paths()
 
         # Add paths specified in the environment variables LDFLAGS and
         # CPPFLAGS for header and library files.
@@ -458,10 +456,7 @@
         # directly since an inconsistently reproducible issue comes up where
         # the environment variable is not set even though the value were passed
         # into configure and stored in the Makefile (issue found on OS X 10.3).
-        for env_var, arg_name, dir_list in (
-                ('LDFLAGS', '-R', self.compiler.runtime_library_dirs),
-                ('LDFLAGS', '-L', self.compiler.library_dirs),
-                ('CPPFLAGS', '-I', self.compiler.include_dirs)):
+        for env_var, arg_name, dir_list in ():
             env_val = sysconfig.get_config_var(env_var)
             if env_val:
                 # To prevent optparse from raising an exception about any
@@ -486,17 +481,6 @@
                     for directory in reversed(options.dirs):
                         add_dir_to_list(dir_list, directory)
 
-        if os.path.normpath(sys.base_prefix) != '/usr' \
-                and not sysconfig.get_config_var('PYTHONFRAMEWORK'):
-            # OSX note: Don't add LIBDIR and INCLUDEDIR to building a framework
-            # (PYTHONFRAMEWORK is set) to avoid # linking problems when
-            # building a framework with different architectures than
-            # the one that is currently installed (issue #7473)
-            add_dir_to_list(self.compiler.library_dirs,
-                            sysconfig.get_config_var("LIBDIR"))
-            add_dir_to_list(self.compiler.include_dirs,
-                            sysconfig.get_config_var("INCLUDEDIR"))
-
         # lib_dirs and inc_dirs are used to search for files;
         # if a file is found in one of those directories, it can
         # be assumed that no additional -I,-L directives are needed.
@@ -506,6 +490,9 @@
                 '/lib', '/usr/lib',
                 ]
             inc_dirs = self.compiler.include_dirs + ['/usr/include']
+        else:
+            lib_dirs = self.compiler.library_dirs
+            inc_dirs = self.compiler.include_dirs
         exts = []
         missing = []