openvswitch: python: rework host and target dependency

Open vSwitch needs to run python on build machine to make build-time
required files.  python-six library is only required by the openvswitch
python library on target machine, not a build dependency.

We override host PYTHONPATH by overriding it in MAKE_VARS.  This way we
can remove 0003-override-pythonpath-via-make-vars.patch

This also fixes shebang wrongly pointing to python on host

Signed-off-by: Yousong Zhou <yszhou4tech@gmail.com>

net/openvswitch/Makefile

@@ -22,14 +22,14 @@ PKG_SOURCE:=$(PKG_NAME)-$(PKG_VERSION).tar.gz
 PKG_SOURCE_URL:=http://openvswitch.org/releases/
 PKG_HASH:=8d1c439e26d7044f0ec823c7fef1b00b7c6465da0b83a7d0cf3191ed1dc43893
 
-PKG_BUILD_DEPENDS:=python/host python-six/host
-PKG_CONFIG_DEPENDS:=CONFIG_PACKAGE_openvswitch-python
+PKG_BUILD_DEPENDS:=python/host
 
 PKG_BUILD_PARALLEL:=1
 PKG_FIXUP:=autoreconf
 PKG_INSTALL:=1
 
 include $(INCLUDE_DIR)/package.mk
+include ../../lang/python/python-host.mk
 include ../../lang/python/python-package.mk
 
 define Package/openvswitch/Default
@@ -155,12 +155,12 @@ CONFIGURE_VARS += \
 	ovs_cv_flake8=no \
 	ovs_cv_python3=no \
 	ovs_cv_sphinx=no \
+	ovs_cv_python=$(PYTHON) \
+	ovs_cv_python_host=$(HOST_PYTHON_BIN) \
 	KARCH=$(LINUX_KARCH)
 
-MAKE_FLAGS += \
-	ARCH="$(LINUX_KARCH)" \
-	PYTHONPATH="$(HOST_PYTHONPATH)" \
-	PYTHON="$(HOST_PYTHON_BIN)"
+MAKE_VARS += PYTHONPATH="$(HOST_PYTHONPATH)"
+MAKE_FLAGS += ARCH="$(LINUX_KARCH)"
 
 define OvsBinUtility
   define Package/openvswitch-$(2)

net/openvswitch/patches/0003-override-pythonpath-via-make-vars.patch

@@ -1,26 +0,0 @@
-diff --git a/Makefile.am b/Makefile.am
-index a4dd7b8..099a3c1 100644
---- a/Makefile.am
-+++ b/Makefile.am
-@@ -53,7 +53,7 @@ endif
- # foo/__init__.py into an (older) version with plain foo.py, since
- # foo/__init__.pyc will cause Python to ignore foo.py.
- run_python = \
--	PYTHONPATH=$(top_srcdir)/python$(psep)$$PYTHONPATH \
-+	PYTHONPATH=$(top_srcdir)/python$(psep)$(PYTHONPATH) \
- 	PYTHONDONTWRITEBYTECODE=yes $(PYTHON)
- 
- ALL_LOCAL =
-diff --git a/Makefile.in b/Makefile.in
-index 8df66e2..98b54bf 100644
---- a/Makefile.in
-+++ b/Makefile.in
-@@ -1654,7 +1654,7 @@ AM_CFLAGS = -Wstrict-prototypes $(WARNING_FLAGS) $(OVS_CFLAGS) \
- # foo/__init__.py into an (older) version with plain foo.py, since
- # foo/__init__.pyc will cause Python to ignore foo.py.
- run_python = \
--	PYTHONPATH=$(top_srcdir)/python$(psep)$$PYTHONPATH \
-+	PYTHONPATH=$(top_srcdir)/python$(psep)$(PYTHONPATH) \
- 	PYTHONDONTWRITEBYTECODE=yes $(PYTHON)
- 
- 

net/openvswitch/patches/0003-python-separate-host-target-python-for-cross-compile.patch

@@ -0,0 +1,59 @@
+From dd52bf474a8c03a3b7a5d73229b64971d76adafd Mon Sep 17 00:00:00 2001
+From: Yousong Zhou <yszhou4tech@gmail.com>
+Date: Wed, 28 Feb 2018 13:42:44 +0800
+Subject: [PATCH] python: separate host/target python for cross-compile
+
+At the moment, python-six is a requirement for openvswitch python
+library on target machine.
+
+Signed-off-by: Yousong Zhou <yszhou4tech@gmail.com>
+---
+ Makefile.am       |  2 +-
+ m4/openvswitch.m4 | 12 ++++--------
+ 2 files changed, 5 insertions(+), 9 deletions(-)
+
+diff --git a/Makefile.am b/Makefile.am
+index 31d6331..4b9e8d4 100644
+--- a/Makefile.am
++++ b/Makefile.am
+@@ -59,7 +59,7 @@ endif
+ # foo/__init__.pyc will cause Python to ignore foo.py.
+ run_python = \
+ 	PYTHONPATH=$(top_srcdir)/python$(psep)$$PYTHONPATH \
+-	PYTHONDONTWRITEBYTECODE=yes $(PYTHON)
++	PYTHONDONTWRITEBYTECODE=yes $(PYTHON_HOST)
+ 
+ ALL_LOCAL =
+ BUILT_SOURCES =
+diff --git a/m4/openvswitch.m4 b/m4/openvswitch.m4
+index 00ffad3..52f207b 100644
+--- a/m4/openvswitch.m4
++++ b/m4/openvswitch.m4
+@@ -347,20 +347,16 @@ else:
+    if test $ovs_cv_python = no; then
+      AC_MSG_ERROR([cannot find python 2.7 or higher.])
+    fi
+-   AM_MISSING_PROG([PYTHON], [python])
++   AC_SUBST([PYTHON])
+    PYTHON=$ovs_cv_python
++   AM_MISSING_PROG([PYTHON_HOST], [python])
++   PYTHON_HOST=$ovs_cv_python_host
+ 
+    # HAVE_PYTHON is always true.  (Python has not always been a build
+    # requirement, so this variable is now obsolete.)
+    AC_SUBST([HAVE_PYTHON])
+    HAVE_PYTHON=yes
+-   AM_CONDITIONAL([HAVE_PYTHON], [test "$HAVE_PYTHON" = yes])
+-
+-   AC_MSG_CHECKING([whether $PYTHON has six library])
+-   if ! $PYTHON -c 'import six ; six.moves.range' >&AS_MESSAGE_LOG_FD 2>&1; then
+-     AC_MSG_ERROR([Missing Python six library or version too old.])
+-   fi
+-   AC_MSG_RESULT([yes])])
++   AM_CONDITIONAL([HAVE_PYTHON], [test "$HAVE_PYTHON" = yes])])
+ 
+ dnl Checks for Python 3.x, x >= 4.
+ AC_DEFUN([OVS_CHECK_PYTHON3],
+-- 
+1.8.3.1
+