[SE-0470] Prohibit isolated conformances in dynamic casts that can't safely use them #80337
Conversation
This file contains hidden or bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
…mances" flag When performing a dynamic cast to an existential type that satisfies (Metatype)Sendable, it is unsafe to allow isolated conformances of any kind to satisfy protocol requirements for the existential. Identify these cases and mark the corresponding cast instructions with a new flag, `[prohibit_isolated_conformances]` that will be used to indicate to the runtime that isolated conformances need to be rejected.
Certain dynamic casts cannot work safely with isolated conformances, regardless of what executor the code runs on. For such cases, reject all attempts to conform to the type.
DougGregor
requested review from
ktoso,
mikeash,
al45tair,
xymus,
eeckstein,
jckarter and
rjmccall
as code owners
|
@swift-ci please smoke test |
|
@swift-ci please smoke test |
|
@swift-ci please smoke test macOS |
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
Add this suggestion to a batch that can be applied as a single commit.
This suggestion is invalid because no changes were made to the code.
Suggestions cannot be applied while the pull request is closed.
Suggestions cannot be applied while viewing a subset of changes.
Only one suggestion per line can be applied in a batch.
Add this suggestion to a batch that can be applied as a single commit.
Applying suggestions on deleted lines is not supported.
You must change the existing code in this line in order to create a valid suggestion.
Outdated suggestions cannot be applied.
This suggestion has been applied or marked resolved.
Suggestions cannot be applied from pending reviews.
Suggestions cannot be applied on multi-line comments.
Suggestions cannot be applied while the pull request is queued to merge.
Suggestion cannot be applied right now. Please check back later.
When performing a dynamic cast to an existential type that satisfies (Metatype)Sendable, it is unsafe to allow isolated conformances of any kind to satisfy protocol requirements for the existential. Identify these cases and mark the corresponding cast instructions in SIL with a new flag,
[prohibit_isolated_conformances]that will be used to indicate to theruntime that isolated conformances need to be rejected. Update the runtime to respect this flag, in which case it rejects all attempts to use an isolated conformance.