[Buildroot] [PATCH v6 2/4] package/python-numpy: fixup numpy distutils for cross compilation

[Jagan Teki <jagan@amarulasolutions.com>]

From: Esben Haabendal <esben@geanix.com>

Fix problems using the numpy distutils extension for cross compilation,
so that linking with npymath library will use target library when building
target packages.

Signed-off-by: Esben Haabendal <esben@geanix.com>
Signed-off-by: Jagan Teki <jagan@amarulasolutions.com>
---
Changes for v6:
- drop python2 staging directory

 package/python-numpy/python-numpy.mk | 17 +++++++++++++++++
 1 file changed, 17 insertions(+)

diff --git a/package/python-numpy/python-numpy.mk b/package/python-numpy/python-numpy.mk
index 6d4cd22e62..18d9f40887 100644
--- a/package/python-numpy/python-numpy.mk
+++ b/package/python-numpy/python-numpy.mk
@@ -32,6 +32,23 @@ define PYTHON_NUMPY_CONFIGURE_CMDS
 	echo "include_dirs = $(STAGING_DIR)/usr/include" >> $(@D)/site.cfg
 endef
 
+# The numpy distutils extensions are not very cross friendly.  It comes with
+# it's own pkg-config look-alike, which we are patching to allow overriding
+# where it locates the configuration files.  This allows us to use fixed up
+# target configuration files, which we make sure includes full path to the
+# target staging area, so that when building for target, we actually use the
+# target libraries.  Without this, target builds using numpy distutils
+# extensions (such as fx. python-scipy) will use the host libraries, which
+# obviously will not work.
+PYTHON_NUMPY_STAGING_DIR = $(STAGING_DIR)/usr/lib/python$(PYTHON3_VERSION_MAJOR)/site-packages/numpy
+PYTHON_NUMPY_NPY_PKG_CONFIG_PATH=$(PYTHON_NUMPY_STAGING_DIR)/core/lib/npy-pkg-config
+define PYTHON_NUMPY_FIXUP_NPY_PKG_CONFIG_FILES
+	sed -e '/^pkgdir=/d' \
+	    -e '/^prefix=/i pkgdir=$(PYTHON_NUMPY_STAGING_DIR)/core' \
+	    -i $(PYTHON_NUMPY_NPY_PKG_CONFIG_PATH)/npymath.ini
+endef
+PYTHON_NUMPY_POST_INSTALL_STAGING_HOOKS += PYTHON_NUMPY_FIXUP_NPY_PKG_CONFIG_FILES
+
 # Some package may include few headers from NumPy, so let's install it
 # in the staging area.
 PYTHON_NUMPY_INSTALL_STAGING = YES
-- 
2.17.1