Rip out reporting indirection from CompilationUnit

Inline the forwarders from CompilationUnit, which should not affect behavior.
Since all forwarders lead to global.reporter, don't first navigate
to a compilation unit, only to then forward back to global.reporter.

The cleanup in the previous commits revealed a ton of confusion
regarding how to report an error.

This was a mechanical search/replace, which has low potential for messing
things up, since the list of available methods are disjoint between
`reporter` and `currentRun.reporting`. The changes involving `typer.context`
were done previously.

Essentially, there are three ways to report:
  - via typer.context, so that reporting can be silenced (buffered)
  - via global.currentRun.reporting, which summarizes (e.g., deprecation)
  - via global.reporter, which is (mostly) stateless and straightforward.

Ideally, these should all just go through `global.currentRun.reporting`,
with the typing context changing that reporter to buffer where necessary.

After the refactor, these are the ways in which we report (outside of typer):
  - reporter.comment
  - reporter.echo
  - reporter.error
  - reporter.warning
  - currentRun.reporting.deprecationWarning
  - currentRun.reporting.incompleteHandled
  - currentRun.reporting.incompleteInputError
  - currentRun.reporting.inlinerWarning
  - currentRun.reporting.uncheckedWarning

Before:
  - c.cunit.error
  - c.enclosingUnit.deprecationWarning
  - context.unit.error
  - context.unit.warning
  - csymCompUnit.warning
  - cunit.error
  - cunit.warning
  - currentClass.cunit.warning
  - currentIClazz.cunit.inlinerWarning
  - currentRun.currentUnit.error
  - currentRun.reporting
  - currentUnit.deprecationWarning
  - currentUnit.error
  - currentUnit.warning
  - getContext.unit.warning
  - getCurrentCUnit.error
  - global.currentUnit.uncheckedWarning
  - global.currentUnit.warning
  - global.reporter
  - icls.cunit.warning
  - item.cunit.warning
  - reporter.comment
  - reporter.echo
  - reporter.error
  - reporter.warning
  - reporting.deprecationWarning
  - reporting.incompleteHandled
  - reporting.incompleteInputError
  - reporting.inlinerWarning
  - reporting.uncheckedWarning
  - typer.context.unit.warning
  - unit.deprecationWarning
  - unit.echo
  - unit.error
  - unit.incompleteHandled
  - unit.incompleteInputError
  - unit.uncheckedWarning
  - unit.warning
  - v1.cunit.warning

All these methods ended up calling a method on `global.reporter`
or on `global.currentRun.reporting` (their interfaces are disjoint).

Also clean up `TypeDiagnostics`: inline nearly-single-use private methods.

1 files changed, 5 insertions, 5 deletions

diff --git a/src/compiler/scala/tools/nsc/transform/UnCurry.scala b/src/compiler/scala/tools/nsc/transform/UnCurry.scala
index d77c6b54a9..2209aac00f 100644
--- a/src/compiler/scala/tools/nsc/transform/UnCurry.scala
+++ b/src/compiler/scala/tools/nsc/transform/UnCurry.scala
@@ -93,7 +93,7 @@ abstract class UnCurry extends InfoTransform
     override def transform(tree: Tree): Tree = (
       try postTransform(mainTransform(tree))
       catch { case ex: TypeError =>
-        unit.error(ex.pos, ex.msg)
+        reporter.error(ex.pos, ex.msg)
         debugStack(ex)
         EmptyTree
       }
@@ -174,7 +174,7 @@ abstract class UnCurry extends InfoTransform
           cdef <- catches
           if catchesThrowable(cdef) && !isSyntheticCase(cdef)
         } {
-          unit.warning(body.pos, "catch block may intercept non-local return from " + meth)
+          reporter.warning(body.pos, "catch block may intercept non-local return from " + meth)
         }
 
         Block(List(keyDef), tryCatch)
@@ -706,10 +706,10 @@ abstract class UnCurry extends InfoTransform
      */
     private def saveRepeatedParams(dd: DefDef): Unit =
       if (dd.symbol.isConstructor)
-        unit.error(dd.symbol.pos, "A constructor cannot be annotated with a `varargs` annotation.")
+        reporter.error(dd.symbol.pos, "A constructor cannot be annotated with a `varargs` annotation.")
       else treeInfo.repeatedParams(dd) match {
         case Nil  =>
-          unit.error(dd.symbol.pos, "A method without repeated parameters cannot be annotated with the `varargs` annotation.")
+          reporter.error(dd.symbol.pos, "A method without repeated parameters cannot be annotated with the `varargs` annotation.")
         case reps =>
           repeatedParams(dd.symbol) = reps
       }
@@ -782,7 +782,7 @@ abstract class UnCurry extends InfoTransform
 
       // check if the method with that name and those arguments already exists in the template
       currentClass.info.member(forwsym.name).alternatives.find(s => s != forwsym && s.tpe.matches(forwsym.tpe)) match {
-        case Some(s) => unit.error(dd.symbol.pos,
+        case Some(s) => reporter.error(dd.symbol.pos,
                                    "A method with a varargs annotation produces a forwarder method with the same signature "
                                    + s.tpe + " as an existing method.")
         case None =>