Re: [PATCH v2 16/17] build: add option to version libs using DPDK version

[Luca Boccassi <luca.boccassi@gmail.com>]

On Tue, 2017-09-12 at 11:38 +0100, Bruce Richardson wrote:
> Normally, each library has it's own version number based on the ABI.
> Add an option to have all libs just use the DPDK version number as
> the
> .so version.
> 
> Signed-off-by: Bruce Richardson <bruce.richardson@intel.com>
> Reviewed-by: Harry van Haaren <harry.van.haaren@intel.com>
> ---
>  drivers/meson.build | 8 +++++++-
>  lib/meson.build     | 8 +++++++-
>  meson_options.txt   | 1 +
>  3 files changed, 15 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/meson.build b/drivers/meson.build
> index f19da16fb..0c251bd61 100644
> --- a/drivers/meson.build
> +++ b/drivers/meson.build
> @@ -92,6 +92,12 @@ foreach class:driver_classes
>  						depends:
> [pmdinfogen, tmp_lib])
>  			endforeach
>  
> +			if get_option('per_library_versions')
> +				so_version = '@0@.1'.format(version)
> +			else
> +				so_version = meson.project_version()
> +			endif
> +
>  			# now build the driver itself, and add to
> the drivers list
>  			lib_name = driver_name_fmt.format(name)
>  			version_map = '@0@/@1@/@2@_version.map'.form
> at(
> @@ -105,7 +111,7 @@ foreach class:driver_classes
>  				c_args: cflags,
>  				link_args: '-Wl,--version-script=' +
> version_map,
>  				link_depends: version_map,
> -				version: '@0@.1'.format(version),
> +				version: so_version,
>  				install: true,
>  				install_dir: driver_install_path)
>  
> diff --git a/lib/meson.build b/lib/meson.build
> index d814721de..36652cfe1 100644
> --- a/lib/meson.build
> +++ b/lib/meson.build
> @@ -76,6 +76,12 @@ foreach l:libraries
>  			dep_objs += [get_variable('dep_rte_' + d)]
>  		endforeach
>  
> +		if get_option('per_library_versions')
> +			so_version = '@0@.1'.format(version)
> +		else
> +			so_version = meson.project_version()
> +		endif
> +
>  		version_map = '@0@/@1@/rte_@2@_version.map'.format(
>  				meson.current_source_dir(),
> dir_name, name)
>  		libname = 'rte_' + name
> @@ -87,7 +93,7 @@ foreach l:libraries
>  				include_directories:
> include_directories(dir_name),
>  				link_args: '-Wl,--version-script=' +
> version_map,
>  				link_depends: version_map,
> -				version: '@0@.1'.format(version),
> +				version: so_version,
>  				install: true)
>  		dep = declare_dependency(link_with: lib,
>  				include_directories:
> include_directories(dir_name),
> diff --git a/meson_options.txt b/meson_options.txt
> index 9c45b8159..636226ce8 100644
> --- a/meson_options.txt
> +++ b/meson_options.txt
> @@ -6,3 +6,4 @@ option('allow_invalid_socket_id', type: 'boolean',
> value: false,
>  	description: 'allow out-of-range NUMA socket id\'s for
> platforms that don\'t report the value correctly')
>  option('enable_kmods', type: 'boolean', value: true, description:
> 'build kernel modules')
>  option('kernel_dir', type: 'string', value: '', description: 'path
> to the kernel for building kernel modules')
> +option('per_library_versions', type: 'boolean', value: true,
> description: 'true: each lib gets its own version number, false: DPDK
> version used for each lib')

Hi Bruce,

First of all thanks for implementing this option, and sorry for the
delay.

A couple of minor things:

1) The project version has 3 digits, but the ABI version should have 2
- eg: should be 17.08 but right now it's 17.08.0 - given point releases
will be ABI compatible so they must not change the ABI version. In the
packaging code we use cut to chop it off:

DPDK_ABI := $(shell echo $(DEB_VERSION_UPSTREAM) | cut -d '.'  -f1-2)

Not sure how to achieve the same in a Meson script though (can it shell
out? or are there string manipulation built-ins?), sorry - just
starting to look at it.

Right now the rte_config option allows the user to completely override
the version - I'm fine with having a single boolean provided this
change is applied, it simplifies packaging a bit, but if it's easier
for you to just accepted a version instead of a boolean it's fine as
well, as you prefer

2) When the option is true, it should not generate a symlink with the
ABI "revision", as the first digit is really not the revision, so it
does not make much sense. Worse, it will stop 2 versions being co-
installable (which was the whole point :-) ), as, eg, 17.02, 17.05 and
17.08 will all ship a libfoo.so.17 symlink. I can fix it in the
packaging, but I don't think it should be generated upstream at all
when this option is enabled.

IOW, the following is the current result:

$ ls -l debian/librte-ethdev17.08/usr/lib/x86_64-linux-gnu/
total 72
lrwxrwxrwx 1 lboccass lboccass    24 Sep 13 11:50 librte_ethdev.so.17 -> librte_ethdev.so.17.08.0
-rw-r--r-- 1 lboccass lboccass 71672 Sep 13 11:50 librte_ethdev.so.17.08.0

The expected result would be to create a single file "librte_ethdev.so.17.08" instead.

-- 
Kind regards,
Luca Boccassi