Introduce a way to configure incremental compiler itself instead
of underlying Java/Scala compiler.
Specific list of changes in this commit:
* Add a method to `xsbti.compile.Setup` that returns incremental
compiler options as a `java.util.Map<String, String>`. We considered
statis interface instead of a `Map` but based on mailing
list feedback we decided that it's not the best way to go because
static interface is hard to evolve it by adding new options.
* Since passing `java.util.Map<String, String>` not very convenient
we convert it immediately to `sbt.inc.IncOptions`
* Add options argument to various methods/classes that implement
incremental compilation so in the end options reach
`sbt.inc.IncOptions` object
* Add `incOptions` task that allows users to configure incremental
compiler options in their build files. Default implementation of
that tasks returns just `IncOptions.DEFAULT`
* Both system property `xsbt.inc.debug` and `IncOptions.relationsDebug`
trigger debugging of relations now. In the near future, we should
deprecate use of `xsbt.inc.debug`.
Some methods take a lot of arguments and I'm about to add one more
which will make them too long for easy reading.
This change is changes code formatting only. That's done on purpose
to make it easier to review other changes.
Let's consider compile/inc/src/main/scala/sbt/CompileSetup.scala.
There are multiple Output types, and according to Eclipse importing
xsbti.compile.Output within the package sbt does not work because the
import is shadowed by sbt.Output.
However, compilation proceeds just fine within SBT. Reproducing the
example however gives the same warning, if the files are in the same
project. The problem here is probably that the shadowing Output
is declared in the same package but in another project, and that seems
to give different results in Eclipse and SBT, but relying on
that looks fragile.
Reading the spec is inconclusive since it doesn't match with Scalac's
behavior — see
https://groups.google.com/d/topic/scala-internals/-Rquc2HBYLk/discussion .
ForkTests has the same behavior as CompileSetup.
Grzegorz Kossakowski
Mark Harrah
Paolo G. Giarrusso