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dart/monorepo//9d605c5e5035fccaf6d195193bc9c2e503cfac8d
commit
9d605c5e5035fccaf6d195193bc9c2e503cfac8d
[log]
author
Elliott Brooks <21270878+elliette@users.noreply.github.com>
Tue Nov 26 13:22:23 2024 -0800
committer
dart-internal-monorepo <dart-internal-monorepo@dart-ci-internal.iam.gserviceaccount.com>
Tue Nov 26 13:29:58 2024 -0800
tree
c2274710568902ef197605b647fd51b49f2af011
parent
d51be77e0329c03417f50fe709f05c2ecd8acac0 [diff]
[Widget Inspector] Fix stack overflow error for Flutter web when requesting a large widget tree (#159454)

Fixes https://github.com/flutter/devtools/issues/8553

Context:

A Flutter web customer with a large widget tree was getting a stack
overflow error when they toggled on "show implementation widgets" in the
Flutter DevTools Inspector. This is because building the JSON tree
recursively was hitting Chrome's stack limit.

This PR creates the JSON tree **iteratively** if the `getRootWidgetTree`
service extension is called with `fullDetails = false` (which is what
DevTools uses to fetch the widget tree).

For all other instances of creating a widget JSON map (for example, when
fetching widget properties) the recursive implementation is used. This
allows properties provided by subclasses implementing `toJsonMap` to be
included in the response.

Note: Because with this change `toJsonMap` is only called when
`fullDetails = true` and `toJsonMapIterative` is only called when
`fullDetails = false`, this PR partially reverts the changes in
https://github.com/flutter/flutter/pull/157309.
https://dart.googlesource.com/external/github.com/flutter/flutter/+/21bea32f6620e0f08e9e16fc31617fd88c20a902
2 files changed
tree: c2274710568902ef197605b647fd51b49f2af011
  1. ci/
  2. tools/
  3. .gitignore
  4. commits.json
  5. DEPS
  6. OWNERS
  7. README.md
README.md

Monorepo

A gclient solution for checking out Dart and Flutter source trees

Monorepo is:

  • Optimized for Tip-of-Tree testing: The Monorepo DEPS used to check out Dart and Flutter dependencies comes from the Flutter engine DEPS with updated dependencies from Dart.

Checking out Monorepo

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

Building Flutter engine

Flutter's instructions for building the engine are at Compiling the engine

They can be followed closely, with a few changes:

  • Googlers working on Dart do not need to switch to Fuchsia's Goma RBE, except for Windows. The GOMA_DIR enviroment variable can just point to the .cipd_bin directory in a depot_tools installation, and just goma_ctl ensure_start is sufficient.
  • The --no-prebuilt-dart-sdk option has to be added to every gn command, so that the build is set up to build and use a local Dart SDK.
  • The --full-dart-sdk option must be added to gn for the host build target if you will be building web or desktop apps.

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

Building Flutter apps

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

Testing

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

Troubleshooting

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.

Windows

  • On Windows, gclient sync needs to be run in an administrator session, because some installed dependencies create symlinks.