Update widget location tracking to use the new generalized api by schultek · Pull Request #189725 · flutter/flutter

schultek · 2026-07-20T14:21:37Z

This refactors Flutters widget tracking setup to use the new generalized CreationLocation API introduced in dart-lang/sdk@9e8fdef

CC @dcharkes

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This pull request migrates widget creation tracking from the custom internal _Location and _HasCreationLocation implementations to the standard developer.CreationLocation API. It updates WidgetInspectorService to use developer.CreationLocation.of() and replaces the --track-widget-creation compiler flag with --track-creation-locations across the Flutter tools and associated tests. There are no review comments to address, and I have no additional feedback to provide.

dcharkes · 2026-07-21T07:19:04Z

https://flutter-dashboard.appspot.com/#/presubmit?repo=flutter&pr=189725&sha=3528464e42a786cb9afead6dac8598f981aaa1b6&job=Linux%20tool_tests_general

https://logs.chromium.org/logs/flutter/buildbucket/cr-buildbucket/8675749755251589137/+/u/run_test.dart_for_tool_tests_shard_and_subshard_general/stdout

From the looks if it, we just need to update a bunch of test expectations:

00:02 +167 -1: test/general.shard/compile_incremental_test.dart: incremental compile single dart compile abnormally terminates [E]
  Expected: throws <Instance of 'ToolExit'>
    Actual: <Instance of 'Future<CompilerOutput?>'>
     Which: threw TestFailure:<Expected: [
                              'Artifact.engineDartAotRuntime',
                              'Artifact.frontendServerSnapshotForEngineDartSdk',
                              '--sdk-root',
                              'sdkroot/',
                              '--incremental',
                              '--target=flutter',
                              '--experimental-emit-debug-metadata',
                              '--output-dill',
                              '/build/',
                              '--packages',
                              '.dart_tool/package_config.json',
                              '-Ddart.vm.profile=false',
                              '-Ddart.vm.product=false',
                              '--enable-asserts',
                              '--track-widget-creation',
                              '--initialize-from-dill',
                              'build/98469b79d3a7ca103e61af5819c93b8c.cache.dill.track.dill',
                              '--verbosity=error'
                            ]
                    Actual: [
                              'Artifact.engineDartAotRuntime',
                              'Artifact.frontendServerSnapshotForEngineDartSdk',
                              '--sdk-root',
                              'sdkroot/',
                              '--incremental',
                              '--target=flutter',
                              '--experimental-emit-debug-metadata',
                              '--output-dill',
                              '/build/',
                              '--packages',
                              '.dart_tool/package_config.json',
                              '-Ddart.vm.profile=false',
                              '-Ddart.vm.product=false',
                              '--enable-asserts',
                              '--track-creation-locations',
                              '--initialize-from-dill',
                              'build/98469b79d3a7ca103e61af5819c93b8c.cache.dill.track.dill',
                              '--verbosity=error'
                            ]
                     Which: at location [14] is '--track-creation-locations' instead of '--track-widget-creation'
                  >

dcharkes

Thanks @schultek 🙏 LGTM

elliette · 2026-07-21T20:00:16Z

          for (final Object dartDefine in dartDefines) '-D$dartDefine',
          ...buildModeOptions(buildMode, dartDefines),
-          if (trackWidgetCreation) '--track-widget-creation',
+          if (trackWidgetCreation) '--track-creation-locations',


This flag (and --no-track-widget-creation) are used in tests, and should be migrated as well. For example:

flutter/dev/bots/suite_runners/run_framework_tests.dart

Line 18 in fd873b1

'--track-widget-creation',

I only changed the flags passed directly to the compiler invocation. The --track-widget-creation flag of the flutter tool stays as is so there aren't any user-visible changes to the cli flags.

elliette · 2026-07-21T20:16:16Z

 ///  * [StatelessWidget], for widgets that always build the same way given a
 ///    particular configuration and ambient state.
 @immutable
+@pragma('track-creation-locations')


To confirm, I assume this requires the --track-widget-location or --track-creation-locations flags and therefore will be a no-op in release mode? This seems safe to me. However, since this is a change to Widget I think a lead should review. FYI @Piinks @justinmc

Yes this has no effect in release mode.

Agreed about release mode, and typically I might be concerned about performance in dev mode, but is this just replacing what used to be hardcoded in the Dart SDK (code)?

// Legacy Case: Check for widget class. if (_isSubclassOfWidget(clazz)) {

In which case it should have no real performance cost at all, even in dev mode. @dcharkes can you confirm?

justinmc

LGTM if I can get @dcharkes or someone from the Dart team to confirm that we don't have to worry about dev mode performance loss.

justinmc · 2026-07-24T20:44:09Z

 ///  * [StatelessWidget], for widgets that always build the same way given a
 ///    particular configuration and ambient state.
 @immutable
+@pragma('track-creation-locations')


Agreed about release mode, and typically I might be concerned about performance in dev mode, but is this just replacing what used to be hardcoded in the Dart SDK (code)?

// Legacy Case: Check for widget class. if (_isSubclassOfWidget(clazz)) {

In which case it should have no real performance cost at all, even in dev mode. @dcharkes can you confirm?

dcharkes · 2026-07-24T20:49:03Z

LGTM if I can get @dcharkes or someone from the Dart team to confirm that we don't have to worry about dev mode performance loss.

Agreed about release mode, and typically I might be concerned about performance in dev mode, but is this just replacing what used to be hardcoded in the Dart SDK (code)?
    // Legacy Case: Check for widget class.
    if (_isSubclassOfWidget(clazz)) {
In which case it should have no real performance cost at all, even in dev mode. @dcharkes can you confirm?

Yes, this is just replacing the hardcoded thing in the SDK!

justinmc

LGTM 👍 . Thanks @dcharkes for confirming. The failure was due to the PR being out of date, so I've rebased it.

…12393) Manual roll requested by [email protected] flutter/flutter@2a230d1...2757a77 2026-07-29 [email protected] Roll Skia from 3ae9e364d30b to 0f35bba4945c (2 revisions) (flutter/flutter#190215) 2026-07-29 [email protected] [web] Fix deferred loading with wasm (flutter/flutter#190140) 2026-07-29 [email protected] Roll Dart SDK from 1bbaacba6a5a to 43f7de5f4977 (1 revision) (flutter/flutter#190211) 2026-07-29 [email protected] Roll Skia from 119cae396625 to 3ae9e364d30b (6 revisions) (flutter/flutter#190208) 2026-07-29 [email protected] [Win32] Ignore mouse move events without capture when dragging (flutter/flutter#190029) 2026-07-29 [email protected] Roll Dart SDK from 49c637261348 to 1bbaacba6a5a (7 revisions) (flutter/flutter#190196) 2026-07-29 [email protected] Roll Skia from 30ad01017a46 to 119cae396625 (2 revisions) (flutter/flutter#190183) 2026-07-29 [email protected] Fix NestedScrollView example crash when switching tabs on desktop (flutter/flutter#186993) 2026-07-29 [email protected] Roll Fuchsia Linux SDK from OZkZC_2CZ_G5rbMIS... to J8rVTlBnjnUpuHYk3... (flutter/flutter#190174) 2026-07-29 [email protected] Update widget location tracking to use the new generalized api (flutter/flutter#189725) 2026-07-29 [email protected] Avoid unnecessary work in `BoxDecoration` and `RenderPhysicalModel` (flutter/flutter#187891) 2026-07-29 [email protected] Fix web context-menu client lifecycle in SelectableRegion (flutter/flutter#189587) 2026-07-29 [email protected] Roll Skia from 70733f74d415 to 30ad01017a46 (2 revisions) (flutter/flutter#190173) 2026-07-29 [email protected] Manual roll of Dart from 28e63ac22d8d to 49c637261348 (flutter/flutter#190158) If this roll has caused a breakage, revert this CL and stop the roller using the controls here: https://autoroll.skia.org/r/flutter-packages Please CC [email protected],[email protected] on the revert to ensure that a human is aware of the problem. To file a bug in Packages: https://github.com/flutter/flutter/issues/new/choose To report a problem with the AutoRoller itself, please file a bug: https://issues.skia.org/issues/new?component=1389291&template=1850622 Documentation for the AutoRoller is here: https://skia.googlesource.com/buildbot/+doc/main/autoroll/README.md

schultek requested a review from elliette July 20, 2026 14:21

flutter-dashboard Bot added the CICD Run CI/CD label Jul 20, 2026

github-actions Bot added tool Affects the "flutter" command-line tool. See also t: labels. framework flutter/packages/flutter repository. See also f: labels. labels Jul 20, 2026

gemini-code-assist Bot reviewed Jul 20, 2026

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dcharkes previously approved these changes Jul 21, 2026

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schultek dismissed dcharkes’s stale review via f4808df July 21, 2026 07:53

elliette reviewed Jul 21, 2026

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schultek requested review from dcharkes and elliette July 22, 2026 07:30

dcharkes approved these changes Jul 22, 2026

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justinmc reviewed Jul 24, 2026

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schultek added 3 commits July 28, 2026 15:43

refactor: widget location tracking using pragma api

f814c4c

fix compile_incremental test

aa08d68

use const widget for tracking detection

fbf8c96

justinmc force-pushed the refactor/widget-location-tracking branch from a058830 to fbf8c96 Compare July 28, 2026 22:43

justinmc approved these changes Jul 28, 2026

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justinmc added the autosubmit Merge PR when tree becomes green via auto submit App label Jul 28, 2026

auto-submit Bot added this pull request to the merge queue Jul 29, 2026

Merged via the queue into flutter:master with commit e47832b Jul 29, 2026
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flutter-dashboard Bot removed the autosubmit Merge PR when tree becomes green via auto submit App label Jul 29, 2026

schultek deleted the refactor/widget-location-tracking branch July 29, 2026 07:26

engine-flutter-autoroll mentioned this pull request Aug 7, 2026

Manual roll Flutter from 2a230d1e8037 to 2757a77a73df (14 revisions) flutter/packages#12393

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schultek commented Jul 20, 2026

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elliette Jul 21, 2026 •

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