[CSOptimizer] Skip ?? if it's involved in optional chain with unres…
#85451
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
Contributor
Author
|
@swift-ci please test |
Contributor
Author
|
@swift-ci please test source compatibility |
…olved result type `??` operator is overloaded on optionality of its result. When the first argument matches exactly, the ranking is going to be skewed towards selecting an overload choice that returns a non-optional type. This is not always correct i.e. when operator is involved in optional chaining. To avoid producing an incorrect favoring, let's skip the this disjunction when constraints associated with result type indicate that it should be optional. Simply adding it as a binding won't work because if the second argument is non-optional the overload that returns `T?` would still have a lower score. Resolves: rdar://164201746
xedin
force-pushed
the
rdar-164201746
branch
from
c7d82b5 to
a01692a
Compare
Contributor
Author
|
@swift-ci please test |
Contributor
Author
|
@swift-ci please test source compatibility |
1 similar comment
Contributor
Author
|
@swift-ci please test source compatibility |
Contributor
Author
|
Source compatibility suite is failing because of UPASS'ing projects. |
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
1 participant
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Outdated suggestions cannot be applied.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.
…olved result type
??operator is overloaded on optionality of its result. When the first argument matches exactly, the ranking is going to be skewed towards selecting an overload choice that returns a non-optional type. This is not always correct i.e. when operator is involved in optional chaining. To avoid producing an incorrect favoring, let's skip the this disjunction when constraints associated with result type indicate that it should be optional.Simply adding it as a binding won't work because if the second argument is non-optional the overload that returns
T?would still have a lower score.Resolves: rdar://164201746