Migrate rust hook to deps and create sync_deps.py

After someone runs upload_revision.py, triggers the packager bots,
and manually copies the packages to prod, they will now run
sync_deps.py to update the DEPS file. After doing that they can
trigger a CQ run to test the new packages.

Bug: b/338612245
Change-Id: Ie95efbf2049e651192d52ca7531c20125b3dd537
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/5536220
Reviewed-by: Hans Wennborg <hans@chromium.org>
Commit-Queue: Josip Sokcevic <sokcevic@chromium.org>
Cr-Commit-Position: refs/heads/main@{#1304616}

DEPS

@@ -540,6 +540,7 @@ allowed_hosts = [
 
    # TODO(337061377): Move into a separate allowed gcs bucket list.
   'chromium-ads-detection',
+  'chromium-browser-clang',
   'chromium-clang-format',
   'chromium-nodejs',
   'chromium-tfhub-models',
@@ -713,6 +714,41 @@ deps = {
       },
     ],
   },
+  # Update prebuilt Rust toolchain.
+  'src/third_party/rust-toolchain': {
+    'dep_type': 'gcs',
+    'bucket': 'chromium-browser-clang',
+    'objects': [
+      {
+        'object_name': 'Linux_x64/rust-toolchain-32dd3795bce8b347fda786529cf5e42a813e0b7d-2-llvmorg-19-init-10646-g084e2b53.tar.xz',
+        'sha256sum': 'e7e236fe6e61b7a41ba6b1e4bc64e91119359cdddce268597c6328b9fea8d76d',
+        'size_bytes': 151082700,
+        'generation': 1715715529295267,
+        'condition': 'host_os == "linux" and non_git_source',
+      },
+      {
+        'object_name': 'Mac/rust-toolchain-32dd3795bce8b347fda786529cf5e42a813e0b7d-2-llvmorg-19-init-10646-g084e2b53.tar.xz',
+        'sha256sum': '3860d592e7f6a853aa06a00642f4110132c7af7f2b91d7bdd399d00dbd5177f6',
+        'size_bytes': 143827372,
+        'generation': 1715715530889094,
+        'condition': 'host_os == "mac" and host_cpu == "x64"',
+      },
+      {
+        'object_name': 'Mac_arm64/rust-toolchain-32dd3795bce8b347fda786529cf5e42a813e0b7d-2-llvmorg-19-init-10646-g084e2b53.tar.xz',
+        'sha256sum': '333dfb93cb0d944acb1ed9f0c44aba9dfdb4e7cd2c660758014338bea37ce8da',
+        'size_bytes': 135183068,
+        'generation': 1715715532458630,
+        'condition': 'host_os == "mac" and host_cpu == "arm64"',
+      },
+      {
+        'object_name': 'Win/rust-toolchain-32dd3795bce8b347fda786529cf5e42a813e0b7d-2-llvmorg-19-init-10646-g084e2b53.tar.xz',
+        'sha256sum': 'f610825518d0f3b6f1e9d2772065165b5bcac3302448a53ac89b3684bae7dbd2',
+        'size_bytes': 206423884,
+        'generation': 1715715534082072,
+        'condition': 'host_os == "win"',
+      },
+    ],
+  },
   'src/third_party/clang-format/script':
     Var('chromium_git') +
     '/external/github.com/llvm/llvm-project/clang/tools/clang-format.git@' +
@@ -4904,12 +4940,6 @@ hooks = [
     'condition': 'not llvm_force_head_revision',
     'action': ['vpython3', 'src/tools/clang/scripts/update.py'],
   },
-  {
-    # Update prebuilt Rust toolchain.
-    'name': 'rust-toolchain',
-    'pattern': '.',
-    'action': ['vpython3', 'src/tools/rust/update_rust.py'],
-  },
   {
     # Build the clang toolchain from tip-of-tree.
     # Note: On Win, this should run after win_toolchain, as it may use it.

docs/updating_clang.md

@@ -26,6 +26,7 @@ An archive of all packages built so far is at https://is.gd/chromeclang
 	successfully finished, run
 	[go/chrome-promote-clang](https://goto.google.com/chrome-promote-clang)
 	on the new Clang package name.
+1.  Run `tools/clang/scripts/sync_deps.py` to update the deps entries in DEPS.
 1.  Run an exhaustive set of try jobs to test the new compiler. The CL
     description created previously by upload_revision.py includes
     `Cq-Include-Trybots:` lines for all needed bots, so it's sufficient to just
@@ -83,4 +84,4 @@ tools/clang/scripts/update.py --package your-package-name
 ```
 
 [an example of adding a new package](https://chromium-review.googlesource.com/c/chromium/src/+/5463029)
-[example bug]: https://crbug.com/335730441
+[example bug]: https://crbug.com/335730441

tools/clang/scripts/sync_deps.py

@@ -0,0 +1,78 @@
+#!/usr/bin/env python3
+# Copyright 2024 The Chromium Authors
+# Use of this source code is governed by a BSD-style license that can be
+# found in the LICENSE file.
+"""This script syncs the Clang and Rust revisions defined in update.py
+and update_rust.py with the deps entries in DEPS."""
+
+import argparse
+import hashlib
+import re
+import os
+import subprocess
+import sys
+import tempfile
+
+from update import DownloadUrl, CDS_URL, CLANG_REVISION
+
+sys.path.append(
+    os.path.join(os.path.dirname(os.path.abspath(__file__)), '..', '..',
+                 'rust'))
+from update_rust import RUST_REVISION, RUST_SUB_REVISION
+
+
+def GetDepsObjectInfo(object_name: str) -> str:
+  url = f'{CDS_URL}/{object_name}'
+  describe_url = f'gs://chromium-browser-clang/{object_name}'
+  output = subprocess.check_output(['gsutil.py', 'stat',
+                                    describe_url]).decode("utf-8")
+  # Output looks like:
+  # ``
+  # gs://bucket/path:
+  #     Creation time:          Wed, 15 May 2024 13:36:30 GMT
+  #     Update time:            Wed, 15 May 2024 13:36:30 GMT
+  #     Storage class:          STANDARD
+  #     Cache-Control:          public, max-age=31536000,no-transform
+  #     Content-Encoding:       gzip
+  #     Content-Length:         5766650
+  #     Content-Type:           application/octet-stream
+  #     Hash (crc32c):          E8z0Sg==
+  #     Hash (md5):             E/XAhJhhpd5+08cdO17CFA==
+  #     ETag:                   COvj8aXjj4YDEAE=
+  #     Generation:             1715780189975019
+  #     Metageneration:         1
+  generation = re.search('Generation:\s+([0-9]+)', output).group(1)
+  size_bytes = re.search('Content-Length:\s+([0-9]+)', output).group(1)
+  with tempfile.NamedTemporaryFile() as f:
+    DownloadUrl(url, f)
+    f.seek(0)
+    sha256sum = hashlib.file_digest(f, 'sha256').hexdigest()
+
+  return f'{object_name},{sha256sum},{size_bytes},{generation}'
+
+
+def GetRustObjectNames() -> list:
+  object_names = []
+  for host_os in ['Linux_x64', 'Mac', 'Mac_arm64', 'Win']:
+    rust_version = (f'{RUST_REVISION}-{RUST_SUB_REVISION}')
+    clang_revision = CLANG_REVISION
+    object_name = f'{host_os}/rust-toolchain-{rust_version}-{clang_revision}'
+    object_names.append(f'{object_name}.tar.xz')
+  return object_names
+
+
+def main():
+  rust_object_infos = [
+      GetDepsObjectInfo(o) for o in sorted(GetRustObjectNames())
+  ]
+
+  rust_object_infos_string = '?'.join(rust_object_infos)
+  rust_deps_entry_path = 'src/third_party/rust-toolchain'
+  rust_setdep_string = f'{rust_deps_entry_path}@{rust_object_infos_string}'
+
+  rust_setdep_args = ['gclient', 'setdep', f'--revision={rust_setdep_string}']
+  subprocess.run(rust_setdep_args)
+
+
+if __name__ == '__main__':
+  sys.exit(main())