build: Preserve upstream git versioning using meson dist

When distributions build and package libcamera libraries, they may not
necessarily run the build in the upstream source tree. In these cases, the git
SHA1 versioning information will be lost.

This change addresses that problem by requiring package managers to run
'meson dist' to create a tarball of the source files and build from there.
On runing 'meson dist', the utils/run-dist.sh script will create a
.tarball-version file in the release tarball with the version string generated
from the existing utils/gen-version.sh script.

The utils/gen-version.sh script has been updated to check for the presence of
this .tarball-version file and read the version string from it instead of
creating one.

Signed-off-by: Naushir Patuck <naush@raspberrypi.com>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>

1 files changed, 9 insertions, 0 deletions

diff --git a/utils/gen-version.sh b/utils/gen-version.sh
index d0048179..eb7c7268 100755
--- a/utils/gen-version.sh
+++ b/utils/gen-version.sh
@@ -6,6 +6,15 @@
 build_dir="$1"
 src_dir="$2"
 
+# If .tarball-version exists, output the version string from the file and exit.
+# This file is auto-generated on a 'meson dist' command from the run-dist.sh
+# script.
+if [ -n "$src_dir" ] && [ -f "$src_dir"/.tarball-version ]
+then
+	cat "$src_dir"/.tarball-version
+	exit 0
+fi
+
 # Bail out if the directory isn't under git control
 git_dir=$(git rev-parse --git-dir 2>&1) || exit 1