Dealias for unused param check #23256
Merged
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
som-snytt
force-pushed
the
issue/23250-warn-aliased-param-type
branch
from
047d302 to
17a1b3f
Compare
tgodzik
reviewed
May 30, 2025
| trait ConfiguredCodec[T] | ||
| object ConfiguredCodec: | ||
| inline final def derived[A](using conf: Configuration)(using inline mirror: Mirror.Of[A]): ConfiguredCodec[A] = // warn // warn | ||
| inline final def derived[A](using conf: Configuration)(using inline mirror: Mirror.Of[A]): ConfiguredCodec[A] = |
There was a problem hiding this comment.
These warning seemed valid, neither mirror nor conf is actually used.
There was a problem hiding this comment.
Is that a consequence of In addition, take an abstract type as not warnable, unless it has an upper bound that is warnable (has non-universal members). ?
There was a problem hiding this comment.
Yes, Mirror doesn't have terms to use. Also Of is an alias so warned previously.
som-snytt
force-pushed
the
issue/23250-warn-aliased-param-type
branch
from
17a1b3f to
c052463
Compare
|
Tweaked to use |
tgodzik
pushed a commit
to scala/scala3-lts
that referenced
this pull request
Jun 19, 2025
Fixes scala#23250 The check for "unused implicit parameter" considers the type of the parameter, but it should dealias first. In addition, take an abstract type as not warnable, unless it has an upper bound that is warnable (has non-universal members). Note that `isSingleton` dealiases. There was an ancient (OG) typo of `&` for `&&` which has gone unfixed despite other edits. The right operand was always just an instanceof. Not sure if the previous idiom saves an opcode, but now it looks like other code nearby. [Cherry-picked 2d18655]
tgodzik
pushed a commit
to scala/scala3-lts
that referenced
this pull request
Jun 20, 2025
Fixes scala#23250 The check for "unused implicit parameter" considers the type of the parameter, but it should dealias first. In addition, take an abstract type as not warnable, unless it has an upper bound that is warnable (has non-universal members). Note that `isSingleton` dealiases. There was an ancient (OG) typo of `&` for `&&` which has gone unfixed despite other edits. The right operand was always just an instanceof. Not sure if the previous idiom saves an opcode, but now it looks like other code nearby. [Cherry-picked 2d18655]
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
3 participants
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.
Fixes #23250
The check for "unused implicit parameter" considers the type of the parameter, but it should dealias first.
In addition, take an abstract type as not warnable, unless it has an upper bound that is warnable (has non-universal members).
Note that
isSingletondealiases.There was an ancient (OG) typo of
&for&&which has gone unfixed despite other edits. The right operand was always just an instanceof. Not sure if the previous idiom saves an opcode, but now it looks like other code nearby.