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/Erasure.scala b/src/compiler/scala/tools/nsc/transform/Erasure.scala
index 2f2142027f..ec4deb6be0 100644
--- a/src/compiler/scala/tools/nsc/transform/Erasure.scala
+++ b/src/compiler/scala/tools/nsc/transform/Erasure.scala
@@ -488,7 +488,7 @@ abstract class Erasure extends AddInterfaces
         ||  (checkBridgeOverrides(member, other, bridge) match {
               case Nil => true
               case es if member.owner.isAnonymousClass => resolveAnonymousBridgeClash(member, bridge); true
-              case es => for ((pos, msg) <- es) unit.error(pos, msg); false
+              case es => for ((pos, msg) <- es) reporter.error(pos, msg); false
             })
       )
 
@@ -724,7 +724,7 @@ abstract class Erasure extends AddInterfaces
         )
         val when = if (exitingRefchecks(lowType matches highType)) "" else " after erasure: " + exitingPostErasure(highType)
 
-        unit.error(pos,
+        reporter.error(pos,
           s"""|$what:
               |${exitingRefchecks(highString)} and
               |${exitingRefchecks(lowString)}
@@ -865,7 +865,7 @@ abstract class Erasure extends AddInterfaces
           fn match {
             case TypeApply(sel @ Select(qual, name), List(targ)) =>
               if (qual.tpe != null && isPrimitiveValueClass(qual.tpe.typeSymbol) && targ.tpe != null && targ.tpe <:< AnyRefTpe)
-                unit.error(sel.pos, "isInstanceOf cannot test if value types are references.")
+                reporter.error(sel.pos, "isInstanceOf cannot test if value types are references.")
 
               def mkIsInstanceOf(q: () => Tree)(tp: Type): Tree =
                 Apply(
@@ -952,7 +952,7 @@ abstract class Erasure extends AddInterfaces
                     case nme.length => nme.array_length
                     case nme.update => nme.array_update
                     case nme.clone_ => nme.array_clone
-                    case _          => unit.error(tree.pos, "Unexpected array member, no translation exists.") ; nme.NO_NAME
+                    case _          => reporter.error(tree.pos, "Unexpected array member, no translation exists.") ; nme.NO_NAME
                   }
                   gen.mkRuntimeCall(arrayMethodName, qual :: args)
                 }
@@ -1055,7 +1055,7 @@ abstract class Erasure extends AddInterfaces
             qual match {
               case Super(_, _) =>
                 // Insert a cast here at your peril -- see SI-5162.
-                unit.error(tree.pos, s"Unable to access ${tree.symbol.fullLocationString} with a super reference.")
+                reporter.error(tree.pos, s"Unable to access ${tree.symbol.fullLocationString} with a super reference.")
                 tree
               case _ =>
                 // Todo: Figure out how qual.tpe could be null in the check above (it does appear in build where SwingWorker.this