When detecting subtyping loops remember problematic cases on the way out #11124
+37
−12
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
The test causes a subtyping test that loops, which is caught by existing infrastructure (LogPendingSubTypesThreshold). However, before reaching the threshold the subtyping check branches off into two equal cases at every iteration. For details, see the bug report. To avoid having to reach the threshold on every one of these branches, remember the problematic subtyping tests on teh way back.
dwijnand
reviewed
Sep 12, 2025
| try { | ||
| pendingSubTypes += p | ||
| isSubType1(tp1, tp2, depth) | ||
| } finally { | ||
| pendingSubTypes -= p | ||
| } | ||
| } else if (!knownFalseSubTypes.isEmpty && knownFalseSubTypes.get(tp1).contains(tp2)) { |
There was a problem hiding this comment.
Should we avoid the option allocation with getOrElse?
There was a problem hiding this comment.
The option allocation is only when there's an entry, which is rare. And with getOrElse there's a Function allocation, no?
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Outdated suggestions cannot be applied.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.
The test causes a subtyping test that loops, which is caught by existing infrastructure (LogPendingSubTypesThreshold). However, before reaching the threshold the subtyping check branches off into two equal cases at every iteration. For details, see the bug report.
To avoid having to reach the threshold on every one of these branches, remember the problematic subtyping tests on the way back.
Fixes scala/bug#13119