commit e4c4d0f839ce4998a46ac3997aea2668d3edd48f
author MarkZ <markzipan@google.com> Tue Mar 11 10:31:19 2025 -0700
committer Commit Queue <dart-scoped@luci-project-accounts.iam.gserviceaccount.com> Tue Mar 11 10:31:19 2025 -0700
tree 822c621761293dcca03d18283af706e0843b91e0
parent 5ec6de2ec9ff898fe8f14cb5832cbf22c664e312

[ddc] Overhauling tearoff equality and identity.

Hot reload requires DDC to update how its tearoffs are represented. Tearoffs obey the following conventions:
* Instance tearoffs are never identical
* Tearoffs with the same object target and name have the same hash code (even if they resolve to different functions across hot reloads)
* Two separate tearoffs of the same member are equal

To support this, tearoff equality must not depend on the bound object and method but a composite of the bound object, torn off member name, and the exact class/object from which the member was torn off.

Notable changes:
* Methods' immediately bound targets are emitted with member signatures. This is required to determine the bound targets for instance and dynamic tearoffs. Bound targets are identified by `libraryUri:class` strings.
* `applyMixin` passes in a 'true' bound target. This is because mixin applications' members are considered children of their 'on' class (not the mixed in class) wrt equality/hashCode.
* `bind` is modified to pass in its 'true' bound object to support mixins' super getters.
* `tearoff` and `staticTearoff` are modified to accept a bound target string (only required for static tearoffs, as they are bound at tearoff-creation-time).
* Static tearoffs avoid using their bound object for hashcode and equality, as these libraries may be wrapped in proxy objects.
* Tearoff equality and hashCode are updated to consider bound object, bound name, and its bound method's immediate target.
* 'noSuchMethod' and 'toString' methods are always accessed through their extension property during signature lookups.


Change-Id: Ica5501b6860c605db50aa945bafb6802a7317511
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/406723
Reviewed-by: Nate Biggs <natebiggs@google.com>
Reviewed-by: Nicholas Shahan <nshahan@google.com>
Commit-Queue: Mark Zhou <markzipan@google.com>