java.lang.Class#newInstance deprecated since Java 9
http://download.java.net/java/jdk9/docs/api/java/lang/Class.html#newInstance--
```
Deprecated. This method propagates any exception thrown by the nullary constructor, including a checked exception. Use of this method effectively bypasses the compile-time exception checking that would otherwise be performed by the compiler. The Constructor.newInstance method avoids this problem by wrapping any exception thrown by the constructor in a (checked) InvocationTargetException.
The call
clazz.newInstance()
can be replaced by
clazz.getDeclaredConstructor().newInstance()
The latter sequence of calls is inferred to be able to throw the additional exception types InvocationTargetException and NoSuchMethodException. Both of these exception types are subclasses of ReflectiveOperationException.
Creates a new instance of the class represented by this Class object. The class is instantiated as if by a new expression with an empty argument list. The class is initialized if it has not already been initialized.
```
This commit addresses several concers:
* Document better the Zinc internal implementation.
* Getting the implementation ready for moving things from internal to
public APIs. This will be done in a follow-up commit.
* Removing `inputs` and `setups` from the `IncrementalCompilerUtil` as
they exist mainly to interface between Scala code and Java code. The
reality is that both Java and Scala developers can easily call the
constructors by themselves and don't learn more API methods.
* Removes unused imports, that emit stupid warnings.
* Make code more readable, especifically in the analyzing compilers for
both Java and Scala, which was hardly understandable and documented.
* Make `AnalyzingJavaCompiler` to extend `JavaCompiler` as
`AnalyzingCompiler` does for `ScalaCompiler`. In an upcoming commit,
`AnalyzingCompiler` will be renamed into `AnalyzingScalaCompiler` for
consistency reasons.
* Replace use of `sbt.util.Logger` helpers by `sbt.util.InterfaceUtil`.
This migrates the `ComponentManager` from librarymanagement, and refactors it to clarify the double caching of the compiler bridge.
The main purpose of this refactoring is to fixsbt/sbt#2539. As it stands, becaue Ivy cache directory is being used as the secondary cache of the compiled compiler bridge, it's annoying to work with the compiler bridge. Instead of using "Ivy cache", the new `ZincComponentManager` accepts `secondaryCacheDir: Option[File]`, which during test defaults to `target/zinc-components`.
Fixessbt/sbt#2539
This adds a macro-level hack to support += op for sourceGenerators and resourceGenerators using RHS of Initialize[Task[Seq[File]]].
When the types match up, the macro now calls `.taskValue` automatically.
This setting controls the maximum width of the ASCII graphs printed
by commands like `inspect tree`. Default value corresponds to the
previously hardcoded value of 40 characters.