[Buildroot] [git commit branch/2021.05.x] python: use system libffi for host-python

[Peter Korsgaard]

commit: https://git.buildroot.net/buildroot/commit/?id=73abb0297e6f1339770506e706be3d85f0374a98
branch: https://git.buildroot.net/buildroot/commit/?id=refs/heads/2021.05.x

python2 contains a bundled copy of libffi which is currently out of sync with
the latest libffi release. There is an option to use a system libffi, buildroot
already uses it for the target python2 build and for python3. In python3, the
bundled copy doesn't exist anymore and the system-provided libffi is required.

The bundled copy currently fails to build on aarch64 host due to a missing
definition of AARCH64_CALL_CONTEXT_SIZE. This define was removed from the
headers in recent libffi releases and the host compiler might be including the
system headers before the bundled headers.

To solve this and since buildroot already relies on system libffi for target
python2 and python3 anyway, switch host python2 to use system libffi.

Signed-off-by: Erico Nunes <nunes.erico at gmail.com>
Reviewed-by: Christian Stewart <christian at paral.in>
Signed-off-by: Yann E. MORIN <yann.morin.1998 at free.fr>
(cherry picked from commit b31f7bc9587170855cd99769db87a5fb32b6724b)
Signed-off-by: Peter Korsgaard <peter at korsgaard.com>
---
 package/python/python.mk | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/package/python/python.mk b/package/python/python.mk
index f4f9f8563b..ae99f382f9 100644
--- a/package/python/python.mk
+++ b/package/python/python.mk
@@ -24,6 +24,7 @@ HOST_PYTHON_CONF_OPTS += \
 	--disable-sqlite3 \
 	--disable-tk \
 	--with-expat=system \
+	--with-system-ffi \
 	--disable-curses \
 	--disable-codecs-cjk \
 	--disable-nis \
@@ -56,7 +57,7 @@ HOST_PYTHON_MAKE = $(MAKE1)
 
 PYTHON_DEPENDENCIES = host-python libffi $(TARGET_NLS_DEPENDENCIES)
 
-HOST_PYTHON_DEPENDENCIES = host-expat host-zlib
+HOST_PYTHON_DEPENDENCIES = host-expat host-libffi host-zlib
 
 ifeq ($(BR2_PACKAGE_HOST_PYTHON_SSL),y)
 HOST_PYTHON_DEPENDENCIES += host-openssl