[PATCH v2 06/11] meson: wire up generation of distribution archive

From: Patrick Steinhardt <ps@pks.im>
Date: Jan 14, 2025, 11:56 UTC
Message-ID: <20250114-b4-pks-meson-additions-v2-6-8d7ec676cfd9@pks.im>
In-Reply-To: <20250114-b4-pks-meson-additions-v2-0-8d7ec676cfd9@pks.im>

Meson knows to generate distribution archives via `meson dist`. In addition to generating the archive itself, this target also knows to compile and execute tests from that archive, which helps to ensure that the result is an adequate drop-in replacement for the versioned project.

While this already works as-is, one omission is that we don't propagate the commit that this is built from into the resulting archive. This can be fixed though by adding a distribution script that propagates the version into the "version" file, which GIT-VERSION-GEN knows to read if present.

Use GIT-VERSION-GEN to populate that file. As the script is executed in the build directory, not in the directory where we generate the archive, we have adapt it to honor the "MESON_DIST_ROOT" environment variable.

Signed-off-by: Patrick Steinhardt <ps@pks.im>
---
 GIT-VERSION-GEN |  4 ++++
 meson.build     | 12 ++++++++++++
 2 files changed, 16 insertions(+)

diff --git a/GIT-VERSION-GEN b/GIT-VERSION-GEN
index 9d201a98fd2766911544225c62159cbfe8dff5fe..f6764555ce6fd46ca4ddbaebb3b48809707e60f8 100755
--- a/GIT-VERSION-GEN
+++ b/GIT-VERSION-GEN
@@ -28,6 +28,10 @@ case "$2" in
 esac
 
 OUTPUT="$3"
+if test -n "$OUTPUT" && test -n "$MESON_DIST_ROOT"
+then
+    OUTPUT="$MESON_DIST_ROOT/$OUTPUT"
+fi
 
 # Protect us from reading Git version information outside of the Git directory
 # in case it is not a repository itself, but embedded in an unrelated
diff --git a/meson.build b/meson.build
index ab4f229436d3070de692a24c3a196a79d214b46f..5d074134195e5689d08da5597f0859d9623d014e 100644
--- a/meson.build
+++ b/meson.build
@@ -1947,6 +1947,18 @@ devenv.set('GIT_BUILD_DIR', meson.current_build_dir())
 devenv.prepend('PATH', meson.current_build_dir() / 'bin-wrappers')
 meson.add_devenv(devenv)
 
+# Generate the 'version' file in the distribution tarball. This is used via
+# `meson dist -C <builddir>` to populate the source archive with the Git
+# version that the archive is being generated from. GIT-VERSION-GEN knows to
+# pick up this file.
+meson.add_dist_script(
+  shell,
+  meson.current_source_dir() / 'GIT-VERSION-GEN',
+  meson.current_source_dir(),
+  '--format=@GIT_VERSION@',
+  'version',
+)
+
 summary({
   'curl': curl.found(),
   'expat': expat.found(),

-- 
2.48.0.257.gd3603152ad.dirty