Sema: Fix cycle between closure type computation and EmittedMembersRequest #33750
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
…quest EmittedMembersRequest needs a stable order for synthesized members to ensure that vtable layout is computed consistently across frontend jobs. This used to use the mangled name as the sort key. However, the mangling includes the type of all outer contexts, and if an outer type is a closure, we would need to compute the type of the closure. Computing the type of a closure might require type checking its body though, which would in turn type check the local class, which would invoke EmittedMembersRequest, introducing a cycle. Instead, let's use the DeclName and string-ified type as the sort key. This is simpler to compute than th mangled name, and breaks the cycle. Fixes <rdar://problem/67842221>.
|
@swift-ci Please smoke test |
|
@swift-ci Please test source compatibility |
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Outdated suggestions cannot be applied.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.
EmittedMembersRequest needs a stable order for synthesized members
to ensure that vtable layout is computed consistently across frontend
jobs. This used to use the mangled name as the sort key.
However, the mangling includes the type of all outer contexts, and if
an outer type is a closure, we would need to compute the type of the
closure. Computing the type of a closure might require type checking
its body though, which would in turn type check the local class, which
would invoke EmittedMembersRequest, introducing a cycle.
Instead, let's use the DeclName and string-ified type as the sort key.
This is simpler to compute than th mangled name, and breaks the cycle.
Fixes rdar://problem/67842221.