From b12d7b6db12b0830f021df5058b347f030feac70 Mon Sep 17 00:00:00 2001
From: Jeffery To <jeffery.to@gmail.com>
Date: Thu, 19 Nov 2015 00:34:14 +0800
Subject: [PATCH] python: add capability to install python packages for the
 host

Some python packages (e.g. cffi) compile one or more shared libraries
as part of their setup process. When these packages are setup
dependencies of other packages (e.g. cryptography), these packages (and
their shared libraries) will need to be loaded on the host system.

This adds a makefile, similar to python-package.mk, to simplify
installing python packages on the host.

Signed-off-by: Jeffery To <jeffery.to@gmail.com>
---
 lang/python/Makefile             |  5 ++-
 lang/python/files/python-host.mk | 53 ++++++++++++++++++++++++++++++++
 2 files changed, 57 insertions(+), 1 deletion(-)
 create mode 100644 lang/python/files/python-host.mk

diff --git a/lang/python/Makefile b/lang/python/Makefile
index 698f4bee6..29e93a037 100644
--- a/lang/python/Makefile
+++ b/lang/python/Makefile
@@ -138,7 +138,10 @@ define Build/InstallDev
 	$(INSTALL_DIR) $(STAGING_DIR)/mk/
 	$(INSTALL_DIR) $(1)/usr/include/ $(1)/usr/lib/ $(1)/usr/lib/pkgconfig
 	$(INSTALL_DIR) $(1)/usr/lib/python$(PYTHON_VERSION)/
-	$(INSTALL_DATA) ./files/python-package.mk $(STAGING_DIR)/mk/
+	$(INSTALL_DATA) \
+		./files/python-package.mk \
+		./files/python-host.mk \
+		$(STAGING_DIR)/mk/
 	$(CP) \
 		$(PKG_INSTALL_DIR)/usr/include/python$(PYTHON_VERSION) \
 		$(1)/usr/include/
diff --git a/lang/python/files/python-host.mk b/lang/python/files/python-host.mk
new file mode 100644
index 000000000..ed0ef4159
--- /dev/null
+++ b/lang/python/files/python-host.mk
@@ -0,0 +1,53 @@
+#
+# Copyright (C) 2015 OpenWrt.org
+#
+# This is free software, licensed under the GNU General Public License v2.
+# See /LICENSE for more information.
+#
+
+HOST_PYTHON_INC_DIR:=$(STAGING_DIR_HOST)/include/python$(PYTHON_VERSION)
+
+HOST_PYTHON_PKG_DIR:=/lib/python$(PYTHON_VERSION)/site-packages
+
+HOST_PYTHONPATH:=$(HOST_PYTHON_LIB_DIR):$(STAGING_DIR_HOST)/$(HOST_PYTHON_PKG_DIR)
+define HostHostPython
+	(	export PYTHONPATH="$(HOST_PYTHONPATH)"; \
+		export PYTHONOPTIMIZE=""; \
+		export PYTHONDONTWRITEBYTECODE=1; \
+		export _python_sysroot="$(STAGING_DIR_HOST)"; \
+		export _python_prefix=""; \
+		export _python_exec_prefix=""; \
+		$(1) \
+		$(HOST_PYTHON_BIN) $(2); \
+	)
+endef
+
+# These configure args are needed in detection of path to Python header files
+# using autotools.
+HOST_CONFIGURE_ARGS += \
+	_python_sysroot="$(STAGING_DIR_HOST)" \
+	_python_prefix="" \
+	_python_exec_prefix=""
+
+# $(1) => build subdir
+# $(2) => additional arguments to setup.py
+# $(3) => additional variables
+define Build/Compile/HostPyMod
+	$(call HostHostPython, \
+		cd $(HOST_BUILD_DIR)/$(strip $(1)); \
+		CC="$(HOSTCC)" \
+		CCSHARED="$(HOSTCC) $(HOST_FPIC)" \
+		CXX="$(HOSTCXX)" \
+		LD="$(HOSTCC)" \
+		LDSHARED="$(HOSTCC) -shared" \
+		CFLAGS="$(HOST_CFLAGS)" \
+		CPPFLAGS="$(HOST_CPPFLAGS) -I$(HOST_PYTHON_INC_DIR)" \
+		LDFLAGS="$(HOST_LDFLAGS) -lpython$(PYTHON_VERSION)" \
+		_PYTHON_HOST_PLATFORM=linux2 \
+		__PYVENV_LAUNCHER__="/usr/bin/$(PYTHON)" \
+		$(3) \
+		, \
+		./setup.py $(2) \
+	)
+endef
+