Allow to use deterministic mtime in jar

mesonbuild/scripts/depfixer.py

@@ -4,6 +4,7 @@
 from __future__ import annotations
 
 
+import datetime
 import sys
 import os
 import stat
@@ -532,7 +533,20 @@ def fix_jar(fname: str) -> None:
     # special-casing for the manifest file, so we can re-add it as a normal
     # archive member.  This puts the manifest at the end of the jar rather
     # than the beginning, but the spec doesn't forbid that.
-    subprocess.check_call(['jar', 'ufM', fname, 'META-INF/MANIFEST.MF'])
+    source_date_epoch = os.environ.get('SOURCE_DATE_EPOCH')
+    if source_date_epoch:
+        # We want to adjust mtime for deterministic .jar file results:
+        source_date_epoch = max(int(source_date_epoch), 315529202) # zip cannot represent earlier timestamps
+        formatted_date = datetime.datetime.fromtimestamp(source_date_epoch, datetime.timezone.utc).isoformat()
+        # One cannot mix --date with old style bunched options and other jar
+        # variants seem to not understand new-style options,
+        # so we need some duplication here for maximum compatibility
+        cmd = ['jar', f'--date={formatted_date}', '-u', '-M', '-f']
+    else:
+        cmd = ['jar', 'ufM']
+
+    cmd.extend([fname, 'META-INF/MANIFEST.MF'])
+    subprocess.check_call(cmd)
 
 def fix_rpath(fname: str, rpath_dirs_to_remove: T.Set[bytes], new_rpath: T.Union[str, bytes], final_path: str, install_name_mappings: T.Dict[str, str], verbose: bool = True) -> None:
     global INSTALL_NAME_TOOL  # pylint: disable=global-statement

unittests/baseplatformtests.py

@@ -91,6 +91,7 @@ def setUpClass(cls) -> None:
         cls.unit_test_dir = os.path.join(src_root, 'test cases/unit')
         cls.rewrite_test_dir = os.path.join(src_root, 'test cases/rewrite')
         cls.linuxlike_test_dir = os.path.join(src_root, 'test cases/linuxlike')
+        cls.java_test_dir = os.path.join(src_root, 'test cases/java')
         cls.objc_test_dir = os.path.join(src_root, 'test cases/objc')
         cls.objcpp_test_dir = os.path.join(src_root, 'test cases/objcpp')
         cls.darwin_test_dir = os.path.join(src_root, 'test cases/darwin')

unittests/linuxliketests.py

@@ -9,6 +9,7 @@
 import os
 import shutil
 import hashlib
+import zipfile
 from unittest import mock, skipUnless, SkipTest
 from glob import glob
 from pathlib import Path
@@ -2013,6 +2014,20 @@ def test_rust_staticlib_rlib_deps(self):
         for param in linker['parameters']:
             self.assertNotIn('liblib.rlib', param)
 
+    def test_jar_manifest_mtime(self):
+        '''
+        Test that jar creation can use SOURCE_DATE_EPOCH for mtime
+        '''
+        testdir = os.path.join(self.java_test_dir, '1 basic')
+        self.init(testdir)
+        self.build()
+        self.install(override_envvars={'SOURCE_DATE_EPOCH': '1770700000'})
+        jarfile = f'{self.installdir}/usr/bin/myprog.jar'
+        # check mtime in created .jar file
+        with zipfile.ZipFile(jarfile) as zip:
+            dt = zip.getinfo('META-INF/MANIFEST.MF').date_time
+            self.assertEqual(dt, (2026, 2, 10, 5, 6, 40))
+
     def test_sanitizers(self):
         testdir = os.path.join(self.unit_test_dir, '129 sanitizers')