| # |
| # SPDX-License-Identifier: GPL-2.0-only |
| # |
| import os |
| import subprocess |
| import bb |
| |
| # For reproducible builds, this code sets the default SOURCE_DATE_EPOCH in each |
| # component's build environment. The format is number of seconds since the |
| # system epoch. |
| # |
| # Upstream components (generally) respect this environment variable, |
| # using it in place of the "current" date and time. |
| # See https://reproducible-builds.org/specs/source-date-epoch/ |
| # |
| # The default value of SOURCE_DATE_EPOCH comes from the function |
| # get_source_date_epoch_value which reads from the SDE_FILE, or if the file |
| # is not available will use the fallback of SOURCE_DATE_EPOCH_FALLBACK. |
| # |
| # The SDE_FILE is normally constructed from the function |
| # create_source_date_epoch_stamp which is typically added as a postfuncs to |
| # the do_unpack task. If a recipe does NOT have do_unpack, it should be added |
| # to a task that runs after the source is available and before the |
| # do_deploy_source_date_epoch task is executed. |
| # |
| # If a recipe wishes to override the default behavior it should set it's own |
| # SOURCE_DATE_EPOCH or override the do_deploy_source_date_epoch_stamp task |
| # with recipe-specific functionality to write the appropriate |
| # SOURCE_DATE_EPOCH into the SDE_FILE. |
| # |
| # SOURCE_DATE_EPOCH is intended to be a reproducible value. This value should |
| # be reproducible for anyone who builds the same revision from the same |
| # sources. |
| # |
| # There are 4 ways the create_source_date_epoch_stamp function determines what |
| # becomes SOURCE_DATE_EPOCH: |
| # |
| # 1. Use the value from __source_date_epoch.txt file if this file exists. |
| # This file was most likely created in the previous build by one of the |
| # following methods 2,3,4. |
| # Alternatively, it can be provided by a recipe via SRC_URI. |
| # |
| # If the file does not exist: |
| # |
| # 2. If there is a git checkout, use the last git commit timestamp. |
| # Git does not preserve file timestamps on checkout. |
| # |
| # 3. Use the mtime of "known" files such as NEWS, CHANGLELOG, ... |
| # This works for well-kept repositories distributed via tarball. |
| # |
| # 4. Use the modification time of the youngest file in the source tree, if |
| # there is one. |
| # This will be the newest file from the distribution tarball, if any. |
| # |
| # 5. Fall back to a fixed timestamp (SOURCE_DATE_EPOCH_FALLBACK). |
| # |
| # Once the value is determined, it is stored in the recipe's SDE_FILE. |
| |
| def get_source_date_epoch_from_known_files(d, sourcedir): |
| source_date_epoch = None |
| newest_file = None |
| known_files = set(["NEWS", "ChangeLog", "Changelog", "CHANGES"]) |
| for file in known_files: |
| filepath = os.path.join(sourcedir, file) |
| if os.path.isfile(filepath): |
| mtime = int(os.lstat(filepath).st_mtime) |
| # There may be more than one "known_file" present, if so, use the youngest one |
| if not source_date_epoch or mtime > source_date_epoch: |
| source_date_epoch = mtime |
| newest_file = filepath |
| if newest_file: |
| bb.debug(1, "SOURCE_DATE_EPOCH taken from: %s" % newest_file) |
| return source_date_epoch |
| |
| def find_git_folder(d, sourcedir): |
| # First guess: WORKDIR/git |
| # This is the default git fetcher unpack path |
| workdir = d.getVar('WORKDIR') |
| gitpath = os.path.join(workdir, "git/.git") |
| if os.path.isdir(gitpath): |
| return gitpath |
| |
| # Second guess: ${S} |
| gitpath = os.path.join(sourcedir, ".git") |
| if os.path.isdir(gitpath): |
| return gitpath |
| |
| # Perhaps there was a subpath or destsuffix specified. |
| # Go looking in the WORKDIR |
| exclude = set(["build", "image", "license-destdir", "patches", "pseudo", |
| "recipe-sysroot", "recipe-sysroot-native", "sysroot-destdir", "temp"]) |
| for root, dirs, files in os.walk(workdir, topdown=True): |
| dirs[:] = [d for d in dirs if d not in exclude] |
| if '.git' in dirs: |
| return os.path.join(root, ".git") |
| |
| bb.warn("Failed to find a git repository in WORKDIR: %s" % workdir) |
| return None |
| |
| def get_source_date_epoch_from_git(d, sourcedir): |
| if not "git://" in d.getVar('SRC_URI') and not "gitsm://" in d.getVar('SRC_URI'): |
| return None |
| |
| gitpath = find_git_folder(d, sourcedir) |
| if not gitpath: |
| return None |
| |
| # Check that the repository has a valid HEAD; it may not if subdir is used |
| # in SRC_URI |
| p = subprocess.run(['git', '--git-dir', gitpath, 'rev-parse', 'HEAD'], stdout=subprocess.PIPE, stderr=subprocess.STDOUT) |
| if p.returncode != 0: |
| bb.debug(1, "%s does not have a valid HEAD: %s" % (gitpath, p.stdout.decode('utf-8'))) |
| return None |
| |
| bb.debug(1, "git repository: %s" % gitpath) |
| p = subprocess.run(['git', '--git-dir', gitpath, 'log', '-1', '--pretty=%ct'], check=True, stdout=subprocess.PIPE) |
| return int(p.stdout.decode('utf-8')) |
| |
| def get_source_date_epoch_from_youngest_file(d, sourcedir): |
| if sourcedir == d.getVar('WORKDIR'): |
| # These sources are almost certainly not from a tarball |
| return None |
| |
| # Do it the hard way: check all files and find the youngest one... |
| source_date_epoch = None |
| newest_file = None |
| for root, dirs, files in os.walk(sourcedir, topdown=True): |
| files = [f for f in files if not f[0] == '.'] |
| |
| for fname in files: |
| filename = os.path.join(root, fname) |
| try: |
| mtime = int(os.lstat(filename).st_mtime) |
| except ValueError: |
| mtime = 0 |
| if not source_date_epoch or mtime > source_date_epoch: |
| source_date_epoch = mtime |
| newest_file = filename |
| |
| if newest_file: |
| bb.debug(1, "Newest file found: %s" % newest_file) |
| return source_date_epoch |
| |
| def fixed_source_date_epoch(d): |
| bb.debug(1, "No tarball or git repo found to determine SOURCE_DATE_EPOCH") |
| source_date_epoch = d.getVar('SOURCE_DATE_EPOCH_FALLBACK') |
| if source_date_epoch: |
| bb.debug(1, "Using SOURCE_DATE_EPOCH_FALLBACK") |
| return int(source_date_epoch) |
| return 0 |
| |
| def get_source_date_epoch(d, sourcedir): |
| return ( |
| get_source_date_epoch_from_git(d, sourcedir) or |
| get_source_date_epoch_from_youngest_file(d, sourcedir) or |
| fixed_source_date_epoch(d) # Last resort |
| ) |
| |
| def epochfile_read(epochfile, d): |
| cached, efile = d.getVar('__CACHED_SOURCE_DATE_EPOCH') or (None, None) |
| if cached and efile == epochfile: |
| return cached |
| |
| if cached and epochfile != efile: |
| bb.debug(1, "Epoch file changed from %s to %s" % (efile, epochfile)) |
| |
| source_date_epoch = int(d.getVar('SOURCE_DATE_EPOCH_FALLBACK')) |
| try: |
| with open(epochfile, 'r') as f: |
| s = f.read() |
| try: |
| source_date_epoch = int(s) |
| except ValueError: |
| bb.warn("SOURCE_DATE_EPOCH value '%s' is invalid. Reverting to SOURCE_DATE_EPOCH_FALLBACK" % s) |
| source_date_epoch = int(d.getVar('SOURCE_DATE_EPOCH_FALLBACK')) |
| bb.debug(1, "SOURCE_DATE_EPOCH: %d" % source_date_epoch) |
| except FileNotFoundError: |
| bb.debug(1, "Cannot find %s. SOURCE_DATE_EPOCH will default to %d" % (epochfile, source_date_epoch)) |
| |
| d.setVar('__CACHED_SOURCE_DATE_EPOCH', (str(source_date_epoch), epochfile)) |
| return str(source_date_epoch) |
| |
| def epochfile_write(source_date_epoch, epochfile, d): |
| |
| bb.debug(1, "SOURCE_DATE_EPOCH: %d" % source_date_epoch) |
| bb.utils.mkdirhier(os.path.dirname(epochfile)) |
| |
| tmp_file = "%s.new" % epochfile |
| with open(tmp_file, 'w') as f: |
| f.write(str(source_date_epoch)) |
| os.rename(tmp_file, epochfile) |