install-build-deps: add rust toolchain support

Also adds rust formatting support as it demonstrates how to
use the installed toolchain.

Author: dreveman

.gitignore

@@ -1,6 +1,7 @@
 .aider*
 .android_config
 .cache
+.cargo
 .ccls
 .ccls-cache
 .clangd

buildtools/.gitignore

@@ -39,6 +39,7 @@ buildtools_hash_revision_for_cache_on_ci.txt
 /open_csd/
 /pigweed/
 /protobuf/
+/rustup/
 /sqlglot/
 /sqlite_src/
 /sqlite/

contrib/rust-sdk/.gitignore

@@ -0,0 +1,2 @@
+debug
+target

python/tools/code_format_all.py

@@ -20,6 +20,7 @@
 from code_format_gn import GnFormat
 from code_format_python import Yapf
 from code_format_sql import SqlGlot
+from code_format_rust import RustFormat
 from code_format_ui import UI_CODE_FORMATTERS
 
 if __name__ == '__main__':
@@ -28,5 +29,6 @@
       GnFormat(),
       Yapf(),
       SqlGlot(),
+      RustFormat(),
   ] + UI_CODE_FORMATTERS
   sys.exit(run_code_formatters(formatters))

python/tools/code_format_rust.py

@@ -0,0 +1,50 @@
+#!/usr/bin/env python3
+# Copyright (C) 2025 The Android Open Source Project
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#      http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+import os
+import sys
+
+from code_format_utils import ROOT_DIR, CodeFormatterBase, run_code_formatters
+
+RUSTUP_HOME = os.path.join(ROOT_DIR, 'buildtools/rustup')
+CARGO_HOME = os.path.join(ROOT_DIR, '.cargo')
+
+
+class RustFormat(CodeFormatterBase):
+
+  def __init__(self):
+    super().__init__(name='rustfmt', exts=['.rs'])
+
+  def run_formatter(self, repo_root: str, check_only: bool, files: list[str]):
+    tool = '.cargo/bin/rustfmt'
+    if not os.path.exists(tool):
+      err = f'Cannot find {tool}\nRun tools/install-build-deps --rust-toolchain'
+      print(err, file=sys.stderr)
+      return 127
+    cmd = [tool, '--edition', '2024', '--unstable-features', '--skip-children']
+    if check_only:
+      cmd += ['--check']
+    cmd += files
+    env = os.environ.copy()
+    env['RUSTUP_HOME'] = RUSTUP_HOME
+    env['CARGO_HOME'] = CARGO_HOME
+    return self.check_call(cmd, env=env)
+
+  def print_fix_hint(self):
+    print('Run tools/format-rust-sources to fix', file=sys.stderr)
+
+
+if __name__ == '__main__':
+  sys.exit(run_code_formatters([RustFormat()]))

python/tools/code_format_utils.py

@@ -91,9 +91,9 @@ def build_file_list(args):
     cmd = ['git', 'diff', '--name-only', '--diff-filter=crd', upstream_branch]
     return subprocess.check_output(cmd, text=True).strip().splitlines()
 
-  def check_call(self, cmd, **kwargs):
+  def check_call(self, cmd, env=None, **kwargs):
     try:
-      subprocess.check_call(cmd, **kwargs)
+      subprocess.check_call(cmd, env=env, **kwargs)
       return 0
     except subprocess.CalledProcessError as ex:
       print('`%s` returned %d' % (' '.join(cmd)[:128], ex.returncode))

tools/format-rust-sources

@@ -0,0 +1,18 @@
+#!/usr/bin/env bash
+# Copyright (C) 2025 The Android Open Source Project
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#      http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+set -eu
+ROOT_DIR="$(dirname $(cd -P ${BASH_SOURCE[0]%/*}; pwd))"
+exec /usr/bin/env python3 $ROOT_DIR/python/tools/code_format_rust.py "$@"

tools/install-build-deps

@@ -495,6 +495,14 @@ BIGTRACE_DEPS = [
                '6c3e8482f7b4e3b307bb42afbb85fd8771da86b8', 'all', 'all', True)
 ]
 
+# Dependencies to build Rust SDK.
+BUILD_DEPS_RUST = [
+    Dependency(
+        'buildtools/rustup/rustup-init.sh', 'https://sh.rustup.rs',
+        '17247e4bcacf6027ec2e11c79a72c494c9af69ac8d1abcc1b271fa4375a106c2',
+        'all', 'all'),
+]
+
 # Sysroots required to cross-compile Linux targets (linux-arm{,64}).
 # These are taken from Chromium's build/linux/sysroot_scripts/sysroots.json.
 BUILD_DEPS_LINUX_CROSS_SYSROOTS = [
@@ -513,7 +521,7 @@ BUILD_DEPS_LINUX_CROSS_SYSROOTS = [
 ALL_DEPS = (
     BUILD_DEPS_HOST + BUILD_DEPS_BAZEL + BUILD_DEPS_ANDROID +
     BUILD_DEPS_LINUX_CROSS_SYSROOTS + TEST_DEPS_ANDROID +
-    EMULATOR_DEPS_ANDROID + UI_DEPS)
+    EMULATOR_DEPS_ANDROID + UI_DEPS + BUILD_DEPS_RUST)
 
 ROOT_DIR = os.path.dirname(os.path.dirname(os.path.abspath(__file__)))
 UI_DIR = os.path.join(ROOT_DIR, 'ui')
@@ -526,6 +534,11 @@ PYTHON_VENV_BIN_DIR = os.path.join(
 PYTHON_STATUS_FILE = os.path.join(PYTHON_VENV_DIR, '.last_install')
 PYTHON_REQUIREMENTS = os.path.join(ROOT_DIR, 'python', 'requirements.txt')
 TEST_DATA_SCRIPT = os.path.join(TOOLS_DIR, 'test_data')
+RUST_TOOLCHAIN = os.environ.get("RUST_TOOLCHAIN", "nightly-2025-01-03")
+RUSTUP_HOME = os.path.join(ROOT_DIR, 'buildtools/rustup')
+RUSTUP_INIT_FILE = os.path.join(RUSTUP_HOME, 'rustup-init.sh')
+CARGO_HOME = os.path.join(ROOT_DIR, '.cargo')
+RUSTUP_FILE = os.path.join(CARGO_HOME, 'bin/rustup')
 
 
 def CheckCallRetry(*args, **kwargs):
@@ -693,6 +706,55 @@ def CheckNodeModules():
   return expected == actual
 
 
+def InstallRustToolchain(force_clean=False):
+  if force_clean:
+    logging.info('Clearing %s', RUSTUP_HOME)
+    subprocess.check_call(
+        ['git', 'clean', '-qxffd', RUSTUP_HOME, '--exclude=rustup-init.sh'],
+        cwd=ROOT_DIR)
+    logging.info('Clearing %s', CARGO_HOME)
+    subprocess.check_call(['git', 'clean', '-qxffd', CARGO_HOME], cwd=ROOT_DIR)
+
+  cmd = [
+      'sh', RUSTUP_INIT_FILE, '-y', f'--default-toolchain={RUST_TOOLCHAIN}',
+      '--no-modify-path', '--profile=minimal', '--component=rustfmt,clippy'
+  ]
+  env = os.environ.copy()
+  env['RUSTUP_HOME'] = RUSTUP_HOME
+  env['CARGO_HOME'] = CARGO_HOME
+  logging.info(f'Installing rust toolchain using `{" ".join(cmd)}`')
+  subprocess.check_call(cmd, cwd=ROOT_DIR, env=env)
+
+
+def CheckRustToolchain():
+  """Returns True if the toolchain is up-to-date.
+
+  Checks if Rust toolchains are up to date using `rustup check`
+  and returns True if up to date, False otherwise.
+  """
+  if not os.path.exists(RUSTUP_FILE):
+    return False
+
+  # Run rustup check and capture its output and exit code.
+  env = os.environ.copy()
+  env['RUSTUP_HOME'] = RUSTUP_HOME
+  env['CARGO_HOME'] = CARGO_HOME
+  result = subprocess.run([RUSTUP_FILE, "check"],
+                          capture_output=True,
+                          text=True,
+                          check=False)
+  if result.returncode == 0:
+    if "update available" not in result.stdout.lower(
+    ) and "update available" not in result.stderr.lower():
+      return True
+  logging.info("rustup check stdout:")
+  logging.info(result.stdout)
+  logging.info("rustup check stderr:")
+  logging.info(result.stderr)
+  logging.info(f"rustup check exit code: {result.returncode}")
+  return False
+
+
 def CheckPythonVenv():
   """Returns True if the python venv is up-to-date."""
   if not os.path.exists(PYTHON_STATUS_FILE):
@@ -799,6 +861,10 @@ def Main():
       default=GetArch(),
       choices=['arm64', 'x64'],
       help='Override the autodetected build CPU architecture')
+  parser.add_argument(
+      '--rust-toolchain',
+      action='store_true',
+      help='Rust toolchain to build Rust SDK')
   args = parser.parse_args()
   if args.verify:
     CheckHashes()
@@ -830,8 +896,11 @@ def Main():
   # TODO(b/360084012) Change the arg name to bigtrace
   if args.grpc:
     deps += BIGTRACE_DEPS
+  if args.rust_toolchain:
+    deps += BUILD_DEPS_RUST
   deps_updated = False
   nodejs_updated = False
+  rustup_updated = False
 
   for old_dir in CLEANUP_OLD_DIRS:
     RmtreeIfExists(os.path.join(ROOT_DIR, old_dir))
@@ -877,6 +946,8 @@ def Main():
       shutil.move(download_path, local_path)
       if 'nodejs' in dep.target_folder:
         nodejs_updated = True
+      if 'rustup' in dep.target_folder:
+        rustup_updated = True
 
     assert (HashLocalFile(local_path) == dep.checksum)
 
@@ -935,6 +1006,12 @@ def Main():
     elif venv_needs_update:
       InstallPythonVenv()
 
+  if args.rust_toolchain:
+    if args.check_only:
+      deps_updated |= not CheckRustToolchain()
+    else:
+      InstallRustToolchain(force_clean=rustup_updated)
+
   # Install the pre-push hook if the .git/hooks directory exists and it's a
   # non check-only invocation. Not on windows (symlinks are not supported
   # there).