Jason Zaugg

Improve performance of Analysis deserialization.

1

We have been looking at ways to improve the performance of analysis deserialization. In large builds this can be a major factor in the responsiveness of the build when Zinc...

Using Java Mission control, take a heap dump of a running SBT build. The resulting UI includes the JOverflow analysis of opportunities to reduce footprint. `ClassLike.savedAnnotations` contains duplicate strings for...

Could apiHash be computed as an unordered hash of the name hashes?

2

```scala val apiHash: HashAPI.Hash = HashAPI(classApi) val nameHashes = (new xsbt.api.NameHashing(options.useOptimizedSealed())).nameHashes(classApi) classApi.definitionType match { case d @ (DefinitionType.ClassDef | DefinitionType.Trait) => val extraApiHash = { if (d != DefinitionType.Trait) apiHash...

LookupImpl.lookupAnalysis is O(N) wrt classpath length

3

In projects with long classpaths, I've seen this show up in profiles, as called by `memberRef` => `binaryDependency` => `externalDependency` => `getExternalApi`. https://github.com/sbt/zinc/blob/b125d8295cea2c0afc3c3686c1853edf93c4c934/zinc/src/main/scala/sbt/internal/inc/LookupImpl.scala#L43 Could we maintain an index of the...

Under compilation of class that transitively extends trait which has had private field renamed

1

Steps to reproduce in: https://github.com/retronym/zinc-test ``` $ git checkout 2d6edfb && sbt clean compile && git checkout 90072a9 && sbt compile c/console Previous HEAD position was 90072a9 Rename private trait...

``` [error] An exception has been thrown while trying to dump an api diff. [error] scala.MatchError: TraitPrivateMembersModified(a.A) (of class sbt.internal.inc.TraitPrivateMembersModified) [error] at sbt.internal.inc.IncrementalCommon.$anonfun$logApiChanges$1(IncrementalCommon.scala:156) [error] at sbt.internal.inc.IncrementalCommon.$anonfun$logApiChanges$1$adapted(IncrementalCommon.scala:156) [error] at scala.collection.immutable.Set$Set1.foreach(Set.scala:95) [error]...

Refactor Zinc into a compiler plugin?

2

Subclassing `Global` should be a method of last resort when customizing `scalac`, as two such customizations are unable to compose. Could `zinc` be refactored into a compiler plugin? ## Phase...

## Reproduction steps ```scala object repro { trait ScenarioParam { type Builder null) ^ test/files/pos/stabilizer-cyclic.scala:43: error: cyclic aliasing or subtyping involving type Builder stabilizer.m1(x => null) ^ test/files/pos/stabilizer-cyclic.scala:46: error: cyclic...

Array.apply optimization in Cleanup can currently CCE and could be extended to generic (not `<: AnyRef`) arrays

3

The current optimization is unsound: ``` scala> def foo[T : reflect.ClassTag](t: T) = Array.apply[T](t); foo[String]("") def foo[T](t: T)(implicit evidence$1: scala.reflect.ClassTag[T]): Array[T] val res13: Array[String] = Array("") scala> def foo[T