[libcamera-devel] [RFC 2/2] build: Add a "version_sha" meson build option

[Naushir Patuck]

This build option can be used to override the SHA value in the version string
generated by utils/gen-version.sh.

An override is needed if distributions make libcamera builds outside of the
upstream git tree. In these cases, the user can then use the correct SHA value
of the upstream tree instead of the local downstream build tree.

Signed-off-by: Naushir Patuck <naush at raspberrypi.com>
---
 meson.build               | 4 +++-
 meson_options.txt         | 5 +++++
 src/libcamera/meson.build | 3 ++-
 3 files changed, 10 insertions(+), 2 deletions(-)

diff --git a/meson.build b/meson.build
index a49c484fe64e..cea6ca78cfa0 100644
--- a/meson.build
+++ b/meson.build
@@ -16,8 +16,10 @@ project('libcamera', 'c', 'cpp',
 # only. If the source tree isn't under git control, or if it matches the last
 # git version tag, the build metadata (e.g. +211-c94a24f4) is omitted from
 # libcamera_git_version.
+version_sha_override = get_option('version_sha')
 libcamera_git_version = run_command('utils/gen-version.sh',
-                                    meson.build_root()).stdout().strip()
+                                    meson.build_root(),
+                                    version_sha_override).stdout().strip()
 if libcamera_git_version == ''
     libcamera_git_version = meson.project_version()
 endif
diff --git a/meson_options.txt b/meson_options.txt
index 2c80ad8b5e0b..96db8de4cdeb 100644
--- a/meson_options.txt
+++ b/meson_options.txt
@@ -58,3 +58,8 @@ option('v4l2',
         type : 'boolean',
         value : false,
         description : 'Compile the V4L2 compatibility layer')
+
+option('version_sha',
+        type : 'string',
+        value : '',
+        description : 'Custom version sha string to use')
diff --git a/src/libcamera/meson.build b/src/libcamera/meson.build
index 243dd3c180eb..94cded2ce6c3 100644
--- a/src/libcamera/meson.build
+++ b/src/libcamera/meson.build
@@ -93,9 +93,10 @@ endforeach
 
 libcamera_sources += control_sources
 
+version_sha_override = get_option('version_sha')
 gen_version = meson.source_root() / 'utils' / 'gen-version.sh'
 
-version_cpp = vcs_tag(command : [gen_version, meson.build_root()],
+version_cpp = vcs_tag(command : [gen_version, meson.build_root(), version_sha_override],
                       input : 'version.cpp.in',
                       output : 'version.cpp',
                       fallback : meson.project_version())
-- 
2.25.1