Downstream distributors can use this to mark a version with their
preferred version information, like a Linux distribution package version
or the Steam revision it was built to be bundled into, or just to mark
it with the vendor it was built by or the environment it's intended to
be used in.
For instance, in Debian I'd use this by configuring with:
--enable-vendor-info="${DEB_VENDOR} ${DEB_VERSION}"
to get a SDL_REVISION like:
release-2.24.1-0-ga1d1946dc (Debian 2.24.1+dfsg-2)
which gives a Debian user enough information to track down the patches
and build-time configuration that were used for package revision 2.
In Autotools and CMake, this is a configure-time option like any other,
and will go into both SDL_REVISION (via SDL_revision.h) and
SDL_GetRevision().
In other build systems (MSVC, Xcode, etc.), defining the
SDL_VENDOR_INFO macro will get it into the output of SDL_GetRevision(),
although not SDL_REVISION.
Resolves: https://github.com/libsdl-org/SDL/issues/6418
Signed-off-by: Simon McVittie <smcv@collabora.com>
Instead of using a URL and git sha1, this uses `git describe` to
describe the version relative to the nearest previous git tag, which
gives a better indication of whether this is a release, a prerelease,
a slightly patched prerelease, or a long way after the last release
during active development.
This serves two purposes: it makes those APIs more informative, and it
also puts this information into the binary in a form that is easy to
screen-scrape using strings(1). For instance, if the bundled version of
SDL in a game has this, we can see at a glance what version it is.
It's also shorter than using the web address of the origin git
repository and the full git commit sha1.
Also write the computed version into a file ./VERSION in `make dist`
tarballs, so that when we build from a tarball on a system that doesn't
have git available, we still get the version details.
For the Perforce code path in showrev.sh, output the version number
followed by the Perforce revision, in a format reminiscent of
`git describe` (with p instead of g to indicate Perforce).
For the code path with no VCS available at all, put a suffix on the
version number to indicate that this is just a guess (we can't know
whether this SDL version is actually a git snapshot or has been
patched locally or similar).
Resolves: https://github.com/libsdl-org/SDL/issues/6418
Signed-off-by: Simon McVittie <smcv@collabora.com>
