tools: add repo-version to print a package version from git references

Co-authored-by: slipher <slipher@protonmail.com>

Author: illwieckz

.gitignore

@@ -20,6 +20,7 @@ build
 *.dylib
 *.so
 *.a
+__pycache__
 
 #ignore editor temporary files
 .*.swp

tools/git-compute-version/GitComputeVersion.py

@@ -0,0 +1,161 @@
+#! /usr/bin/env python3
+
+# Daemon BSD Source Code
+# Copyright (c) 2024-2026, Daemon Developers
+# All rights reserved.
+#
+# Redistribution and use in source and binary forms, with or without
+# modification, are permitted provided that the following conditions are met:
+#  * Redistributions of source code must retain the above copyright
+#    notice, this list of conditions and the following disclaimer.
+#  * Redistributions in binary form must reproduce the above copyright
+#    notice, this list of conditions and the following disclaimer in the
+#    documentation and/or other materials provided with the distribution.
+#  * Neither the name of the <organization> nor the
+#    names of its contributors may be used to endorse or promote products
+#    derived from this software without specific prior written permission.
+#
+# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
+# ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
+# WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+# DISCLAIMED. IN NO EVENT SHALL <COPYRIGHT HOLDER> BE LIABLE FOR ANY
+# DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
+# (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
+# LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
+# ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+# (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
+# SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+import datetime
+import os.path
+import subprocess
+import sys
+import time
+
+class GitComputeVersion():
+	git_short_ref_length = 7
+
+	def __init__(self, source_dir, allows_stray, is_quiet, is_local):
+		if not os.path.isdir(source_dir):
+			raise(ValueError, "not a directory")
+
+		self.process_stderr = None
+
+		if is_quiet:
+			self.process_stderr = subprocess.DEVNULL
+
+		self.is_local = is_local
+
+		self.source_dir_realpath = os.path.realpath(source_dir)
+
+		self.git_command_list = ["git", "-C", self.source_dir_realpath]
+
+		# Test that Git is available and working.
+		self.runGitCommand(["-v"])
+
+		self.allows_stray = allows_stray
+
+	def runGitCommand(self, command_list):
+		command_list = self.git_command_list + command_list
+
+		process = subprocess.run(command_list,
+			stdout=subprocess.PIPE, stderr=self.process_stderr, text=True, check=True)
+
+		return process.stdout.rstrip()
+
+	def getDateString(self, timestamp):
+		return datetime.datetime.fromtimestamp(timestamp, datetime.UTC).strftime('%Y%m%d-%H%M%S')
+
+	def isGitDirty(self):
+		if self.is_local:
+			lookup_dir_arg = [self.source_dir_realpath]
+		else:
+			lookup_dir_arg = []
+
+		git_status_porcelain_string = self.runGitCommand(
+			["status", "--porcelain", "--"] + lookup_dir_arg)
+
+		return git_status_porcelain_string != ""
+
+	def getVersionString(self):
+		# Fallback version string for stray repositories (not tracked by git yet).
+		tag_string="0"
+		date_string="-" + self.getDateString(time.time())
+		ref_string=""
+		dirt_string="+stray"
+
+		# Git returns an error if the directory is not a Git repository or it has no
+		# commits. It also may return an error if the repo is broken somehow. We fail
+		# to distinguish these cases and assume it is not a Git repository.
+		try:
+			git_last_commit_string = self.runGitCommand(
+				["rev-parse", "HEAD", "--"])
+		except subprocess.CalledProcessError:
+			if not self.allows_stray:
+				raise
+			return tag_string + date_string + ref_string + dirt_string
+
+		# Now we know we must use a Git-based version string.
+		dirt_string = ""
+
+		# Git prints the current commit reference.
+		git_last_commit_short_string = git_last_commit_string[:self.git_short_ref_length]
+		ref_string = "-" + git_last_commit_short_string
+
+		# Git prints the current commit date.
+		git_last_commit_timestamp_string = self.runGitCommand(
+			["log", "-1", "--pretty=format:%ct"])
+		date_string = "-" + self.getDateString(int(git_last_commit_timestamp_string))
+
+		# Git prints the most recent tag, or a commit hash if there is no tag at all.
+		git_closest_tag_string = self.runGitCommand(
+			["describe", "--always", "--tags", "--abbrev=0", "--match", "v[0-9]*"])
+
+		# If a tag is found:
+		if git_closest_tag_string[0] == "v":
+			git_closest_tag_version_string = git_closest_tag_string[1:]
+			tag_string = git_closest_tag_version_string
+
+			# Git prints a version string that is equal to the most recent tag
+			# if the most recent tag is on the current commit.
+			git_describe_tag_string = self.runGitCommand(
+				["describe", "--tags", "--match", "v[0-9]*"])
+			git_describe_version_string = git_describe_tag_string[1:]
+
+			if git_closest_tag_version_string == git_describe_version_string:
+				# Do not write current commit reference and date in version
+				# string if the tag is on the current commit.
+				date_string = ""
+				ref_string = ""
+
+		if self.isGitDirty():
+			# Write the dirty flag in version string if not everything in
+			# the Git repository is properly committed.
+			dirt_string = "+dirty"
+
+		return tag_string + date_string + ref_string + dirt_string
+
+def getVersionString(source_dir, allows_stray=False, is_quiet=False, is_local=False):
+	return GitComputeVersion(source_dir, allows_stray, is_quiet, is_local).getVersionString()
+
+def main():
+	import argparse
+
+	def existing_dir(path):
+		if not os.path.isdir(path):
+			raise argparse.ArgumentTypeError(f"{path} is not an existing directory")
+		return path
+
+	parser = argparse.ArgumentParser(description="Print repository version string")
+
+	parser.add_argument("-s", "--stray", dest="allows_stray", help="allows stray repositories not tracked by Git", action="store_true")
+	parser.add_argument("-q", "--quiet", dest="is_quiet", help="silence Git errors", action="store_true")
+	parser.add_argument("-l", "--local", dest="is_local", help="look for dirtiness in given directory only, not in whole repository", action="store_true")
+	parser.add_argument(dest="source_dir", nargs="?", metavar="DIRNAME", type=existing_dir, default=".", help="repository path")
+
+	args = parser.parse_args()
+
+	print(getVersionString(args.source_dir, allows_stray=args.allows_stray, is_quiet=args.is_quiet, is_local=args.is_local))
+
+if __name__ == "__main__":
+	main()

tools/git-compute-version/git-compute-version

@@ -0,0 +1,3 @@
+#! /usr/bin/env python3
+from GitComputeVersion import main
+main()