From 94b938bb290a231694e5721368023bd6693bb2ed Mon Sep 17 00:00:00 2001 From: Som Snytt Date: Thu, 15 Sep 2016 23:16:40 -0700 Subject: SI-8040 Warn unused flags Introduce `-Ywarn-unused:x,y,z` and exploit `-Ywarn-unused:patvars`. Although the tree attachment for shielding patvars from warnings is not structural, sneaking the settings flag into the reflection internal TreeGen is awkward. Add test to ensure isolation of patvars warning from others. `-Ywarn-unused-import` is an alias for `-Ywarn-unused:imports`. `-Xlint:unused` is an alias for `-Ywarn-unused`, but not enabled yet. The help text advises to use `-Ywarn-unused`. The future can decide if `-Xlint:unused-imports` is warranted. --- src/reflect/scala/reflect/internal/TreeGen.scala | 10 ++++++++-- 1 file changed, 8 insertions(+), 2 deletions(-) (limited to 'src/reflect/scala/reflect/internal/TreeGen.scala') diff --git a/src/reflect/scala/reflect/internal/TreeGen.scala b/src/reflect/scala/reflect/internal/TreeGen.scala index 373758d0a5..ade9ee84ac 100644 --- a/src/reflect/scala/reflect/internal/TreeGen.scala +++ b/src/reflect/scala/reflect/internal/TreeGen.scala @@ -899,8 +899,8 @@ abstract class TreeGen { case Ident(name) if treeInfo.isVarPattern(tree) && name != nme.WILDCARD => atPos(tree.pos) { val b = Bind(name, atPos(tree.pos.focus) (Ident(nme.WILDCARD))) - if (forFor) b updateAttachment AtBoundIdentifierAttachment - else b + if (!forFor && isPatVarWarnable) b + else b updateAttachment AtBoundIdentifierAttachment } case Typed(id @ Ident(name), tpt) if treeInfo.isVarPattern(id) && name != nme.WILDCARD => atPos(tree.pos.withPoint(id.pos.point)) { @@ -922,7 +922,13 @@ abstract class TreeGen { tree } } + + /** Can be overridden to depend on settings.warnUnusedPatvars. */ + def isPatVarWarnable: Boolean = true + + /** Not in for comprehensions, whether to warn unused pat vars depends on flag. */ object patvarTransformer extends PatvarTransformer(forFor = false) + /** Tag pat vars in for comprehensions. */ object patvarTransformerForFor extends PatvarTransformer(forFor = true) -- cgit v1.2.3