| commit | b32a2e252dd77f4436b5b7f902e721a2795e31a0 | [log] [tgz] |
|---|---|---|
| author | Paul Berry <paulberry@google.com> | Mon Jun 02 13:57:11 2025 -0700 |
| committer | dart-internal-monorepo <dart-internal-monorepo@dart-ci-internal.iam.gserviceaccount.com> | Mon Jun 02 13:58:06 2025 -0700 |
| tree | b2d9384ec0eeabc742f3881336179cd42b1ffa3a | |
| parent | 1417f744250fa7d8f84d25f753166fdd828a69a2 [diff] |
[flow analysis] Fix layering of type promotions in try/finally. A tricky part of the implementation of flow analysis is the handling of try/finally statements. Although promotions are tracked separately in the `try` and `finally` blocks, promotions from both blocks need to be merged together at the conclusion of the finally block. This creates an ambiguity, because each type in a promotion chain is required to be a subtype of the previous, and hence multiple promotions of the same variable are inherently ordered. The ambiguity is: when the promotions from the `try` and `finally` block are merged, which promotions should be applied first? In discussion with the language team, we've decided that the promotions from the `try` block should be applied first, because that matches the order of code execution. This change makes the behavior of flow analysis more uniform, which should make it easier to reason about and maintain. In practice, the difference in behavior is quite subtle, and I don't expect users to notice. However, to be on the safe side, the change in behavior is conditioned on the `sound-flow-analysis` flag, so it will only take effect when the user deliberately upgrades to language version 3.9, and it will not affect already-published packages. A test in google3 showed that no internal code would be broken by force-enabling this change. Fixes https://github.com/dart-lang/language/issues/4382. Change-Id: I0e9f6db808a964e0b4325d3020654a9f2be273a2 Bug: https://github.com/dart-lang/language/issues/4382 Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/432001 Reviewed-by: Konstantin Shcheglov <scheglov@google.com> Commit-Queue: Paul Berry <paulberry@google.com> https://dart.googlesource.com/sdk/+/9f0e5229fa1cf0769da9d84896670a2e93e229ce
Monorepo is:
With depot_tools installed and on your path, create a directory for your monorepo checkout and run these commands to create a gclient solution in that directory:
mkdir monorepo cd monorepo gclient config --unmanaged https://dart.googlesource.com/monorepo gclient sync -D
This gives you a checkout in the monorepo directory that contains:
monorepo/ DEPS - the DEPS used for this gclient checkout commits.json - the pinned commits for Dart, flutter/engine, and flutter/flutter tools/ - scripts used to create monorepo DEPS engine/src/ - the flutter/buildroot repo flutter/ - the flutter/engine repo out/ - the build directory, where Flutter engine builds are created third_party/ - Flutter dependencies checked out by DEPS dart/ - the Dart SDK checkout. third_party - Dart dependencies, also used by Flutter flutter/ - the flutter/flutter repo
Flutter's instructions for building the engine are at Compiling the engine
They can be followed closely, with a few changes:
goma_ctl ensure_start is sufficient.Example build commands that work on linux:
MONOREPO_PATH=$PWD if [[ ! $PATH =~ (^|:)$MONOREPO_PATH/flutter/bin(:|$) ]]; then PATH=$MONOREPO_PATH/flutter/bin:$PATH fi export GOMA_DIR=$(dirname $(command -v gclient))/.cipd_bin goma_ctl ensure_start pushd engine/src flutter/tools/gn --goma --no-prebuilt-dart-sdk --unoptimized --full-dart-sdk autoninja -C out/host_debug_unopt popd
The Flutter commands used to build and run apps will use the locally built Flutter engine and Dart SDK, instead of the one downloaded by the Flutter tool, if the --local-engine option is provided.
For example, to build and run the Flutter spinning square sample on the web platform,
MONOREPO_PATH=$PWD cd flutter/examples/layers flutter --local-engine=host_debug_unopt \ -d chrome run widgets/spinning_square.dart cd $MONOREPO_PATH
To build for desktop, specify the desktop platform device in flutter run as -d macos or -d linux or -d windows. You may also need to run the command
flutter create --platforms=windows,macos,linux
on existing apps, such as sample apps. New apps created with flutter create already include these support files. Details of desktop support are at Desktop Support for Flutter
Tests in the Flutter source tree can be run with the flutter test command, run in the directory of a package containing tests. For example:
MONOREPO_PATH=$PWD cd flutter/packages/flutter flutter test --local-engine=host_debug_unopt cd $MONOREPO_PATH
Please file an issue or email the dart-engprod team with any problems with or questions about using monorepo.
We will update this documentation to address them.
flutter commands may download the engine and Dart SDK files for the configured channel, even though they will be using the local engine and its SDK.gclient sync needs to be run in an administrator session, because some installed dependencies create symlinks.