package:gnuradio: move to python3

From: Gwenhael Goavec-Merou <gwenhael.goavec-merou@trabucayre.com>

gnuradio 3.8.0.0 support both python2 and python3 but python2 is EOL, so move
explicitly to python3.
- depends on python3 to avoid issues with mako at the build time
- add full path to python3 interpreter
- by default gnuradio install python libraries in dist-packages. To force
  installation in site-packages add GR_PYTHON_DIR in CONF_OPTS
- when python support is enabled python-six is mandatory at runtime

Signed-off-by: Gwenhael Goavec-Merou <gwenhael.goavec-merou@trabucayre.com>
---
 package/gnuradio/Config.in   | 7 ++++---
 package/gnuradio/gnuradio.mk | 4 +++-
 2 files changed, 7 insertions(+), 4 deletions(-)

On 05/09/2019 15:40, Gwenhael Goavec-Merou wrote:
> From: Gwenhael Goavec-Merou <gwenhael.goavec-merou@trabucayre.com>
> 
> gnuradio 3.8.0.0 support both python2 and python3 but python2 is EOL, so move
> explicitly to python3.

 python2 is not quite EOL yet :-)

 So I think removing python2 support is a bit premature. That said, if it's
simpler to not support python2, by all means go ahead. But then it should be
explained in the commit message that it's too difficult to support both, and why.

> - depends on python3 to avoid issues with mako at the build time

 What issue is that? There are three possibilities:

BR2_PACKAGE_PYTHON is selected -> host-python-mako will be built for python2
BR2_PACKAGE_PYTHON3 is selected -> host-python-mako will be biult for python3
Neither is selected -> host-python-mako will be built for python2

So I think you only need to have a dependency like:

$(if $(BR2_PACKAGE_PYTHON3),host-python3,host-python)

cfr. libsigrok.


> - add full path to python3 interpreter
> - by default gnuradio install python libraries in dist-packages. To force
>   installation in site-packages add GR_PYTHON_DIR in CONF_OPTS
> - when python support is enabled python-six is mandatory at runtime
> 
> Signed-off-by: Gwenhael Goavec-Merou <gwenhael.goavec-merou@trabucayre.com>
> ---
>  package/gnuradio/Config.in   | 7 ++++---
>  package/gnuradio/gnuradio.mk | 4 +++-
>  2 files changed, 7 insertions(+), 4 deletions(-)
> 
> diff --git a/package/gnuradio/Config.in b/package/gnuradio/Config.in
> index f07bd3d976..85728fa870 100644
> --- a/package/gnuradio/Config.in
> +++ b/package/gnuradio/Config.in
> @@ -1,6 +1,6 @@
>  comment "gnuradio needs a toolchain w/ C++, NPTL, wchar, dynamic library"
>  	depends on BR2_USE_MMU
> -	depends on !BR2_PACKAGE_PYTHON3
> +	depends on !BR2_PACKAGE_PYTHON
>  	depends on !BR2_INSTALL_LIBSTDCPP || !BR2_USE_WCHAR || \
>  		!BR2_TOOLCHAIN_HAS_THREADS_NPTL || BR2_STATIC_LIBS
>  
> @@ -11,7 +11,7 @@ config BR2_PACKAGE_GNURADIO
>  	depends on BR2_TOOLCHAIN_HAS_THREADS_NPTL
>  	depends on BR2_USE_MMU # use fork()
>  	depends on BR2_USE_WCHAR # boost
> -	depends on !BR2_PACKAGE_PYTHON3
> +	depends on !BR2_PACKAGE_PYTHON
>  	select BR2_PACKAGE_BOOST
>  	select BR2_PACKAGE_BOOST_ATOMIC
>  	select BR2_PACKAGE_BOOST_DATE_TIME
> @@ -61,11 +61,12 @@ config BR2_PACKAGE_GNURADIO_FEC
>  
>  config BR2_PACKAGE_GNURADIO_PYTHON
>  	bool "python support"
> -	depends on BR2_PACKAGE_PYTHON
> +	depends on BR2_PACKAGE_PYTHON3
>  	depends on BR2_PACKAGE_PYTHON_NUMPY_ARCH_SUPPORTS
>  	depends on BR2_TOOLCHAIN_USES_GLIBC || BR2_TOOLCHAIN_USES_MUSL # python-numpy
>  	select BR2_PACKAGE_BOOST_PYTHON
>  	select BR2_PACKAGE_PYTHON_NUMPY # runtime
> +	select BR2_PACKAGE_PYTHON_SIX # runtime
>  	help
>  	  Enable python component
>  
> diff --git a/package/gnuradio/gnuradio.mk b/package/gnuradio/gnuradio.mk
> index 162d0c0311..9bdc7dd5fb 100644
> --- a/package/gnuradio/gnuradio.mk
> +++ b/package/gnuradio/gnuradio.mk
> @@ -25,6 +25,7 @@ GNURADIO_DEPENDENCIES += orc
>  endif
>  
>  GNURADIO_CONF_OPTS = \
> +	-DPYTHON_EXECUTABLE=$(HOST_DIR)/bin/python$(PYTHON3_VERSION_MAJOR)m \

 Why does $(HOST_DIR)/bin/python not work? If python3 is enabled on the target,
then $(HOST_DIR)/bin/python will be a symlink to python3.

>  	-DENABLE_DEFAULT=OFF \
>  	-DENABLE_VOLK=ON \
>  	-DENABLE_GNURADIO_RUNTIME=ON \
> @@ -118,8 +119,9 @@ GNURADIO_CONF_OPTS += -DENABLE_GR_FILTER=OFF
>  endif
>  
>  ifeq ($(BR2_PACKAGE_GNURADIO_PYTHON),y)
> -GNURADIO_DEPENDENCIES += python
> +GNURADIO_DEPENDENCIES += python3 python-six

 If python-six is runtime, it shouldn't be added here.


 Regards,
 Arnout


>  GNURADIO_CONF_OPTS += -DENABLE_PYTHON=ON
> +GNURADIO_CONF_OPTS += -DGR_PYTHON_DIR=/usr/lib/python$(PYTHON3_VERSION_MAJOR)/site-packages
>  else
>  GNURADIO_CONF_OPTS += -DENABLE_PYTHON=OFF
>  endif
>