1 files changed, 19 insertions, 6 deletions
diff --git a/python/scripts/precompile_python.py b/python/scripts/precompile_python.py
index e12e7d24c..aa1a5df53 100644
--- a/python/scripts/precompile_python.py
+++ b/python/scripts/precompile_python.py
@@ -16,6 +16,7 @@
 import argparse
 import py_compile
 import os
+import sys
 import shutil
 import tempfile
 import zipfile
@@ -23,22 +24,34 @@ import zipfile
 # This file needs to support both python 2 and 3.
 
 
-def process_one_file(name, inf, outzip):
-    if not name.endswith('.py'):
-        outzip.writestr(name, inf.read())
+def process_one_file(name, infile, outzip):
+    # Create a ZipInfo instance with a fixed date to ensure a deterministic output.
+    # Date was chosen to be the same as
+    # https://cs.android.com/android/platform/superproject/main/+/main:build/soong/jar/jar.go;l=36;drc=2863e4535eb65e15f955dc8ed48fa99b1d2a1db5
+    info = zipfile.ZipInfo(filename=name, date_time=(2008, 1, 1, 0, 0, 0))
+
+    if not info.filename.endswith('.py'):
+        outzip.writestr(info, infile.read())
         return
 
     # Unfortunately py_compile requires the input/output files to be written
     # out to disk.
     with tempfile.NamedTemporaryFile(prefix="Soong_precompile_", delete=False) as tmp:
-        shutil.copyfileobj(inf, tmp)
+        shutil.copyfileobj(infile, tmp)
         in_name = tmp.name
     with tempfile.NamedTemporaryFile(prefix="Soong_precompile_", delete=False) as tmp:
         out_name = tmp.name
     try:
-        py_compile.compile(in_name, out_name, name, doraise=True)
+        # Ensure a deterministic .pyc output by using the hash rather than the timestamp.
+        # Only works on Python 3.7+
+        # See https://docs.python.org/3/library/py_compile.html#py_compile.PycInvalidationMode
+        if sys.version_info >= (3, 7):
+            py_compile.compile(in_name, out_name, info.filename, doraise=True, invalidation_mode=py_compile.PycInvalidationMode.CHECKED_HASH)
+        else:
+            py_compile.compile(in_name, out_name, info.filename, doraise=True)
         with open(out_name, 'rb') as f:
-            outzip.writestr(name + 'c', f.read())
+            info.filename = info.filename + 'c'
+            outzip.writestr(info, f.read())
     finally:
         os.remove(in_name)
         os.remove(out_name)