[PATCH v2 02/11] GIT-VERSION-GEN: allow running without input and output files

From

Patrick Steinhardt <ps@pks.im>

Date

Jan 14, 2025, 11:56 UTC

Message-ID

<20250114-b4-pks-meson-additions-v2-2-8d7ec676cfd9@pks.im>

In-Reply-To

<20250114-b4-pks-meson-additions-v2-0-8d7ec676cfd9@pks.im>

  - We only want to compute the version without anything else, but don't
    have an input file that would match that exact format. While we
    could of course introduce a new file just for that usecase, it feels
    suboptimal to add another file every time we want to have a slightly
    different format for versioned data.

  - The computed version needs to be read from stdout so that Meson can
    wire it up for the project.

Signed-off-by: Patrick Steinhardt <ps@pks.im>
---
 GIT-VERSION-GEN | 44 +++++++++++++++++++++++++++++---------------
 1 file changed, 29 insertions(+), 15 deletions(-)

diff --git a/GIT-VERSION-GEN b/GIT-VERSION-GEN
index b8b683b9337e5771e14a2cfb84022a11489bb432..9d201a98fd2766911544225c62159cbfe8dff5fe 100755
--- a/GIT-VERSION-GEN
+++ b/GIT-VERSION-GEN
@@ -5,21 +5,29 @@ DEF_VER=v2.48.0
 LF='
 '
 
-if test "$#" -ne 3
+if test "$#" -lt 2 || test "$#" -gt 3
 then
-    echo >&2 "USAGE: $0 <SOURCE_DIR> <INPUT> <OUTPUT>"
+    echo >&2 "USAGE: $0 <SOURCE_DIR> (--format=<STRING>|<INPUT>) [<OUTPUT>]"
     exit 1
 fi
 
 SOURCE_DIR="$1"
-INPUT="$2"
-OUTPUT="$3"
 
-if ! test -f "$INPUT"
-then
-	echo >&2 "Input is not a file: $INPUT"
-	exit 1
-fi
+case "$2" in
+--format=*)
+	INPUT="${2#--format=}"
+	;;
+*)
+	if ! test -f "$2"
+	then
+		echo >&2 "Input is not a file: $2"
+		exit 1
+	fi
+	INPUT=$(cat "$2")
+	;;
+esac
+
+OUTPUT="$3"
 
 # 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
@@ -74,19 +82,25 @@ read GIT_MAJOR_VERSION GIT_MINOR_VERSION GIT_MICRO_VERSION GIT_PATCH_LEVEL trail
 $(echo "$GIT_VERSION" 0 0 0 0 | tr '.a-zA-Z-' ' ')
 EOF
 
-sed -e "s|@GIT_VERSION@|$GIT_VERSION|" \
+REPLACED=$(printf "%s" "$INPUT" | sed -e "s|@GIT_VERSION@|$GIT_VERSION|" \
 	-e "s|@GIT_MAJOR_VERSION@|$GIT_MAJOR_VERSION|" \
 	-e "s|@GIT_MINOR_VERSION@|$GIT_MINOR_VERSION|" \
 	-e "s|@GIT_MICRO_VERSION@|$GIT_MICRO_VERSION|" \
 	-e "s|@GIT_PATCH_LEVEL@|$GIT_PATCH_LEVEL|" \
 	-e "s|@GIT_BUILT_FROM_COMMIT@|$GIT_BUILT_FROM_COMMIT|" \
 	-e "s|@GIT_USER_AGENT@|$GIT_USER_AGENT|" \
-	-e "s|@GIT_DATE@|$GIT_DATE|" \
-	"$INPUT" >"$OUTPUT".$$+
+	-e "s|@GIT_DATE@|$GIT_DATE|"
+)
 
-if ! test -f "$OUTPUT" || ! cmp "$OUTPUT".$$+ "$OUTPUT" >/dev/null
+if test -z "$OUTPUT"
 then
-	mv "$OUTPUT".$$+ "$OUTPUT"
+	printf "%s\n" "$REPLACED"
 else
-	rm "$OUTPUT".$$+
+	printf "%s\n" "$REPLACED" >"$OUTPUT".$$+
+	if ! test -f "$OUTPUT" || ! cmp "$OUTPUT".$$+ "$OUTPUT" >/dev/null
+	then
+		mv "$OUTPUT".$$+ "$OUTPUT"
+	else
+		rm "$OUTPUT".$$+
+	fi
 fi

-- 
2.48.0.257.gd3603152ad.dirty