Enable name hashing incremental compilation by default.

[gkossakowski]

This commit changes the default value of IncOptions.nameHashing to be set to true. It means, the improved incremental compilation algorithm known as "name hashing" will be enabled by default.

In order to disable it, users should add this to their sbt configuration:

  incOptions := incOptions.value.withNameHashing(false)

Number of tests has been cleaned up as part of this change. All tests that were marked as name hashing specific are removed. The list includes:

• constants-name-hashing
• import-class-name-hashing
• java-static-name-hashing
• macro-name-hashing
• struct-name-hashing

We'll keep just regular version of those tests. The tests will just exercise the default algorithm: name hashing. This is the first step towards phasing out of the old incremental compilation algorithm.

Apart from that, a few tests changed its status due to enabling name hashing algorithm.

The constants test has been marked pending due to issue described in #1543.

The import-class test has been marked as passing because name hashing tracks dependencies introduced by import statements correctly, now.

The macro test has been marked as pending due to issue described in #1544.

The struct test has been marked as pending due to issue described in #1545.

The java-static has been slightly modified to exercise just static field and not run into the same issue as with constants test.

There are no other known issues related to name hashing so we conclude that name hashing is ready to be enabled by default for all sbt, Scala IDE and zinc users.

[gkossakowski]

Review by @eed3si9n

I hope we can still merge this into 0.13.6. However, I won't mind merging it into some other release if you decide I'm late to the game.

[typesafe-tools]

Can one of the admins verify this patch?

[eed3si9n]

Let's do it!

[eed3si9n]

@gkossakowski I hit the merge button too quickly.
I am now seeing errors in other builds that I suspect is related to this merge. See https://travis-ci.org/sbt/sbt/builds/33265884

[info] java.lang.UnsupportedOperationException: The `++` operation is not supported for relations with different values of `nameHashing` flag.
[info]  at sbt.inc.MRelationsDefaultImpl.$plus$plus(Relations.scala:364)
[info]  at sbt.inc.MAnalysis.$plus$plus(Analysis.scala:141)
[info]  at Build$$anonfun$root$8$$anonfun$apply$1.apply(Build.scala:7)
[info]  at Build$$anonfun$root$8$$anonfun$apply$1.apply(Build.scala:7)
[info]  at scala.collection.LinearSeqOptimized$class.foldLeft(LinearSeqOptimized.scala:111)
[info]  at scala.collection.immutable.List.foldLeft(List.scala:84)
[info]  at scala.collection.TraversableOnce$class.$div$colon(TraversableOnce.scala:138)
[info]  at scala.collection.AbstractTraversable.$div$colon(Traversable.scala:105)
[info]  at Build$$anonfun$root$8.apply(Build.scala:7)
[info]  at Build$$anonfun$root$8.apply(Build.scala:7)
[info]  at scala.Function1$$anonfun$compose$1.apply(Function1.scala:47)
[info]  at sbt.$tilde$greater$$anonfun$$u2219$1.apply(TypeFunctions.scala:40)
[info]  at sbt.std.Transform$$anon$4.work(System.scala:63)
[info]  at sbt.Execute$$anonfun$submit$1$$anonfun$apply$1.apply(Execute.scala:226)
[info]  at sbt.Execute$$anonfun$submit$1$$anonfun$apply$1.apply(Execute.scala:226)
[info]  at sbt.ErrorHandling$.wideConvert(ErrorHandling.scala:17)
[info]  at sbt.Execute.work(Execute.scala:235)
[info]  at sbt.Execute$$anonfun$submit$1.apply(Execute.scala:226)
[info]  at sbt.Execute$$anonfun$submit$1.apply(Execute.scala:226)
[info]  at sbt.ConcurrentRestrictions$$anon$4$$anonfun$1.apply(ConcurrentRestrictions.scala:159)
[info]  at sbt.CompletionService$$anon$2.call(CompletionService.scala:28)
[info]  at java.util.concurrent.FutureTask$Sync.innerRun(FutureTask.java:334)
[info]  at java.util.concurrent.FutureTask.run(FutureTask.java:166)
[info]  at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:471)
[info]  at java.util.concurrent.FutureTask$Sync.innerRun(FutureTask.java:334)
[info]  at java.util.concurrent.FutureTask.run(FutureTask.java:166)
[info]  at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1146)
[info]  at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:615)
[info]  at java.lang.Thread.run(Thread.java:701)

[info] java.lang.AssertionError: assertion failed: Name hashing and Ant-style cannot be enabled at the same time.
[info]  at scala.Predef$.assert(Predef.scala:179)
[info]  at sbt.inc.IncOptions.<init>(IncOptions.scala:96)
[info]  at sbt.inc.IncOptions.withAntStyle(IncOptions.scala:144)
[info]  at $b6aa51793996a2cedafc$$anonfun$$sbtdef$1.apply(/tmp/sbt_fdbbb777/inc-ant-style/build.sbt:3)
[info]  at $b6aa51793996a2cedafc$$anonfun$$sbtdef$1.apply(/tmp/sbt_fdbbb777/inc-ant-style/build.sbt:3)
[info]  at scala.Function1$$anonfun$compose$1.apply(Function1.scala:47)
[info]  at sbt.$tilde$greater$$anonfun$$u2219$1.apply(TypeFunctions.scala:40)
[info]  at sbt.std.Transform$$anon$4.work(System.scala:63)
[info]  at sbt.Execute$$anonfun$submit$1$$anonfun$apply$1.apply(Execute.scala:226)
[info]  at sbt.Execute$$anonfun$submit$1$$anonfun$apply$1.apply(Execute.scala:226)
[info]  at sbt.ErrorHandling$.wideConvert(ErrorHandling.scala:17)
[info]  at sbt.Execute.work(Execute.scala:235)
[info]  at sbt.Execute$$anonfun$submit$1.apply(Execute.scala:226)
[info]  at sbt.Execute$$anonfun$submit$1.apply(Execute.scala:226)
[info]  at sbt.ConcurrentRestrictions$$anon$4$$anonfun$1.apply(ConcurrentRestrictions.scala:159)
[info]  at sbt.CompletionService$$anon$2.call(CompletionService.scala:28)
[info]  at java.util.concurrent.FutureTask$Sync.innerRun(FutureTask.java:334)
[info]  at java.util.concurrent.FutureTask.run(FutureTask.java:166)
[info]  at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:471)
[info]  at java.util.concurrent.FutureTask$Sync.innerRun(FutureTask.java:334)
[info]  at java.util.concurrent.FutureTask.run(FutureTask.java:166)
[info]  at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1146)
[info]  at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:615)
[info]  at java.lang.Thread.run(Thread.java:701)

[gkossakowski]

Sorry for missing those tests. I thought that only source-dependencies would be affected by enabling name hashing.