[libcamera-devel,v4,1/3] meson: Shared Object version handling

17591 diff mbox series

The libcamera project is not yet ready to declare ABI nor API stability,
but it will benefit the community to be able to provide more regular
release cycles to determine 'versioned' points of history.

Ideally, these releases will be made at any ABI breakage, but can be
made at arbitary time based points along the way.

To support releases which may not be ABI stable, declare the soversion
of both the libcamera and libcamera-base library to be dependant upon
both the major minor and patch component of the project version.

As part of this, introduce a new 'Versions' summary section to highlight
the different version components that may become apparent within any
given build.

Reviewed-by: Jacopo Mondi <jacopo@jmondi.org>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Kieran Bingham <kieran.bingham@ideasonboard.com>

---

v4:
 - Use EXCLUDE_SYMLINKS
 - Reduce redundant information from Versions summary
 - -nvm appended when the sources do not match the project version.
 - Fixed the update of the libcamera source version from the project
   version in event of mismatch

v3:
 - fix typo
 - Use libcamera_version directly for SONAME.
 - Fix ordering of EXCLUDE_PATTERNS
 - Use meson.project_version() in the event the git versions
   are incorrect.
 - No need to present libcamera_version anymore
   - Guaranteed to be the same as 'project_version'

 Documentation/Doxyfile.in      |  2 ++
 meson.build                    | 32 ++++++++++++++++++++++++++++++++
 src/libcamera/base/meson.build |  1 +
 src/libcamera/meson.build      |  1 +
 4 files changed, 36 insertions(+)

On Thu, Oct 13, 2022 at 10:59:55AM +0100, Kieran Bingham wrote:
> The libcamera project is not yet ready to declare ABI nor API stability,
> but it will benefit the community to be able to provide more regular
> release cycles to determine 'versioned' points of history.
> 
> Ideally, these releases will be made at any ABI breakage, but can be
> made at arbitary time based points along the way.
> 
> To support releases which may not be ABI stable, declare the soversion
> of both the libcamera and libcamera-base library to be dependant upon
> both the major minor and patch component of the project version.
> 
> As part of this, introduce a new 'Versions' summary section to highlight
> the different version components that may become apparent within any
> given build.

Let's also document why EXCLUDE_SYMLINKS is added:

Bumping versions may leave dangling libcamera.so.* symlinks in build
directories. This will confuse Doxygen which will print during its
directory scanning phase a warning that the symlink can't be read. As we
don't need Doxygen to follow symlinks, disable it with EXCLUDE_SYMLINKS.

> Reviewed-by: Jacopo Mondi <jacopo@jmondi.org>
> Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
> Signed-off-by: Kieran Bingham <kieran.bingham@ideasonboard.com>
> 
> ---
> 
> v4:
>  - Use EXCLUDE_SYMLINKS
>  - Reduce redundant information from Versions summary
>  - -nvm appended when the sources do not match the project version.
>  - Fixed the update of the libcamera source version from the project
>    version in event of mismatch
> 
> v3:
>  - fix typo
>  - Use libcamera_version directly for SONAME.
>  - Fix ordering of EXCLUDE_PATTERNS
>  - Use meson.project_version() in the event the git versions
>    are incorrect.
>  - No need to present libcamera_version anymore
>    - Guaranteed to be the same as 'project_version'
> 
>  Documentation/Doxyfile.in      |  2 ++
>  meson.build                    | 32 ++++++++++++++++++++++++++++++++
>  src/libcamera/base/meson.build |  1 +
>  src/libcamera/meson.build      |  1 +
>  4 files changed, 36 insertions(+)
> 
> diff --git a/Documentation/Doxyfile.in b/Documentation/Doxyfile.in
> index 88dfcddaebf6..e4f0cd426d39 100644
> --- a/Documentation/Doxyfile.in
> +++ b/Documentation/Doxyfile.in
> @@ -66,6 +66,8 @@ EXCLUDE_SYMBOLS        = libcamera::BoundMethodArgs \
>                           *::details \
>                           std::*
>  
> +EXCLUDE_SYMLINKS       = YES
> +
>  HTML_OUTPUT            = api-html
>  
>  GENERATE_LATEX         = NO
> diff --git a/meson.build b/meson.build
> index 2c6173b4f97e..9b0966cb04c9 100644
> --- a/meson.build
> +++ b/meson.build
> @@ -26,6 +26,38 @@ endif
>  
>  libcamera_version = libcamera_git_version.split('+')[0]
>  
> +# A shallow clone, or a clone without a reachable tag equivalent to the
> +# meson.project_version() could leave the project in a mis-described state.
> +# Produce a warning in this event, and fix to a best effort.
> +if libcamera_version != meson.project_version()
> +    warning('The sources disagree about the version: '
> +            + libcamera_version + ' != ' + meson.project_version())
> +
> +    summary({'libcamera git version' : libcamera_git_version,
> +             'Source version match' : false,
> +            },
> +            bool_yn : true, section : 'Versions')
> +
> +    libcamera_git_version = libcamera_git_version.replace(libcamera_version,
> +                                                          meson.project_version())
> +    libcamera_version = meson.project_version()
> +
> +    # Append a marker to show we have modified this version string
> +    libcamera_git_version += '-nvm'
> +endif
> +
> +# Until we make ABI compatible releases, the full libcamera version is used as
> +# the soname. No ABI/API compatibility is guaranteed between releases. (x.x.x)

s/. (x.x.x)/(x.x.x)./ ?

You could also write x.y.z.

Same below.

> +#
> +# When automatic ABI based detection is used to increment the version, this

s/is used/will be used/

Other than this, this looks good to me.

> +# will bump the minor number. (x.x)
> +#
> +# When we declare a stable ABI/API we will provide a 1.0 release and the
> +# soversion at that point will be the 'major' release value. (x)
> +libcamera_soversion = libcamera_version
> +
> +summary({ 'Sources': libcamera_git_version, }, section : 'Versions')
> +
>  # This script generates the .tarball-version file on a 'meson dist' command.
>  meson.add_dist_script('utils/run-dist.sh')
>  
> diff --git a/src/libcamera/base/meson.build b/src/libcamera/base/meson.build
> index 7a75914ab2a8..7a7fd7e4ca87 100644
> --- a/src/libcamera/base/meson.build
> +++ b/src/libcamera/base/meson.build
> @@ -51,6 +51,7 @@ libcamera_base_args = [ '-DLIBCAMERA_BASE_PRIVATE' ]
>  libcamera_base_lib = shared_library('libcamera-base',
>                                      [libcamera_base_sources, libcamera_base_headers],
>                                      version : libcamera_version,
> +                                    soversion : libcamera_soversion,
>                                      name_prefix : '',
>                                      install : true,
>                                      cpp_args : libcamera_base_args,
> diff --git a/src/libcamera/meson.build b/src/libcamera/meson.build
> index 7fcbb2ddc9e7..5f39d2e2c60a 100644
> --- a/src/libcamera/meson.build
> +++ b/src/libcamera/meson.build
> @@ -161,6 +161,7 @@ libcamera_deps = [
>  libcamera = shared_library('libcamera',
>                             libcamera_sources,
>                             version : libcamera_version,
> +                           soversion : libcamera_soversion,
>                             name_prefix : '',
>                             install : true,
>                             include_directories : includes,