[4.0] [Type checker] Check type equality even for argument tuples in Swift 4. #10447
Conversation
This file contains 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
Replace a where Type-pointer-equality check with what it intended, i.e., match up ParenTypes at the top level and perform a deeper equality comparison of the underlying types. Fixes SR-5166 / rdar://problem/32666189. (cherry picked from commit a570a5a)
|
@swift-ci please test |
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Outdated suggestions cannot be applied.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.
Explanation: In Swift 4 mode, comparisons of single-parameter, unlabeled functions could fail when the parameter types were different spellings of the same type. This manifested in nonsensical failures with protocol conformance checking, but could happen in a number of places.
Scope: Obviously-correct code that works in Swift 3.2 mode would fail (or produce weird results) in Swift 4 mode. We've only pinned a single SR/radar on this bug, but I highly suspect that there are others.
Radar: SR-5166 / rdar://problem/32666189.
Risk: Fairly low; the change is localized to Swift 4 mode and "obviously" an improvement of what we previously had.
Testing: New test + normal compiler regression testing.