win: Make chrome.7z generation more deterministic.

mini_installer.exe embeds chrome.7z, and chrome.7z contains timestamps
of all files in the archive. To make chrome.7z more deterministic, give
all files in it deterministic timestamps.

Bug: 330260
Change-Id: Ia251dd38177acbebdde288b86826986f441b2d4d
Reviewed-on: https://chromium-review.googlesource.com/c/1302393Reviewed-by: Gabriel Charette <gab@chromium.org>
Commit-Queue: Nico Weber <thakis@chromium.org>
Cr-Commit-Position: refs/heads/master@{#603171}

build/write_build_date_header.py

@@ -13,10 +13,10 @@ import sys
 def main():
   argument_parser = argparse.ArgumentParser()
   argument_parser.add_argument('output_file', help='The file to write to')
-  argument_parser.add_argument('timestamp')
+  argument_parser.add_argument('timestamp', type=int)
   args = argument_parser.parse_args()
 
-  date = datetime.datetime.utcfromtimestamp(int(args.timestamp))
+  date = datetime.datetime.utcfromtimestamp(args.timestamp)
   output = ('// Generated by //build/write_build_date_header.py\n'
            '#ifndef BUILD_DATE\n'
            '#define BUILD_DATE "{:%b %d %Y %H:%M:%S}"\n'

chrome/installer/mini_installer/BUILD.gn

@@ -5,6 +5,7 @@
 import("//build/config/compiler/compiler.gni")
 import("//build/config/features.gni")
 import("//build/config/ui.gni")
+import("//build/timestamp.gni")
 import("//chrome/process_version_rc_template.gni")
 import("//components/nacl/features.gni")
 import("//third_party/icu/config.gni")
@@ -146,6 +147,8 @@ template("generate_mini_installer") {
       packed_files_rc_file,
     ]
     args = [
+      "--timestamp",
+      build_timestamp,
       "--build_dir",
       rebase_path(root_out_dir, root_build_dir),
       "--staging_dir",

chrome/tools/build/win/create_installer_archive.py

@@ -94,11 +94,12 @@ def CompressUsingLZMA(build_dir, compressed_file, input_file, verbose):
   RunSystemCommand(cmd, verbose)
 
 
-def CopyAllFilesToStagingDir(config, distribution, staging_dir, build_dir,
-                             enable_hidpi):
+def CopyAllNonComponentFilesToStagingDir(config, distribution, staging_dir,
+                                         build_dir, enable_hidpi):
   """Copies the files required for installer archive.
   Copies all common files required for various distributions of Chromium and
   also files for the specific Chromium build specified by distribution.
+  Files that might be needed in a component build are copied later.
   """
   CopySectionFilesToStagingDir(config, 'GENERAL', staging_dir, build_dir)
   if distribution:
@@ -541,15 +542,27 @@ def main(options):
                                 options.output_name)
 
   # Copy the files from the build dir.
-  CopyAllFilesToStagingDir(config, options.distribution,
-                           staging_dir, options.build_dir,
-                           options.enable_hidpi)
+  CopyAllNonComponentFilesToStagingDir(config, options.distribution,
+                                       staging_dir, options.build_dir,
+                                       options.enable_hidpi)
 
   if options.component_build == '1':
     DoComponentBuildTasks(staging_dir, options.build_dir,
                           options.target_arch, options.setup_runtime_deps,
                           options.chrome_runtime_deps, current_version)
 
+  # 7za/7zr don't have a flag to set the timestamp of files in the archive
+  # (important for build reproducibility). Since everything gets copied into
+  # a staging dir, just set the on-disk mtime of everything in the staging
+  # dir instead.
+  if options.timestamp is not None:
+    timestamp_mtime_atime = (options.timestamp, options.timestamp)
+    for path, dirs, files in os.walk(staging_dir):
+      for f in files:
+        os.utime(os.path.join(path, f), timestamp_mtime_atime)
+      for d in dirs:
+        os.utime(os.path.join(path, d), timestamp_mtime_atime)
+
   version_numbers = current_version.split('.')
   current_build_number = version_numbers[2] + '.' + version_numbers[3]
   prev_build_number = ''
@@ -623,6 +636,8 @@ def _ParseOptions():
       help='Specify the target architecture for installer - this is used '
            'to determine which CRT runtime files to pull and package '
            'with the installer archive {x86|x64}.')
+  parser.add_option('--timestamp', type=int,
+      help='If set, used as timestamp for all files in the archive.')
   parser.add_option('-v', '--verbose', action='store_true', dest='verbose',
                     default=False)