From b34aa0e563976b0cc084a35f43a69730662a712a Mon Sep 17 00:00:00 2001
From: Jason Zaugg <jzaugg@gmail.com>
Date: Sat, 15 Feb 2014 12:59:03 +0100
Subject: [PATCH] using compat._ to plug source compatibility breakages

This commit makes the code source compatible across Scala 2.10.3
and https://github.com/scala/scala/pull/3452, which is proposed
for inclusion in Scala 2.11.0-RC1.

We only strictly need the incremental compiler to build on Scala
2.11, as that is integrated into the IDE. But we gain valuable
insight into compiler regressions by building *all* of SBT with
2.11.

We only got there recently (the 0.13 branch of SBT now fully cross
compiles with 2.10.3 and 2.11.0-SNAPSHOT), and this aims to keep
things that way.

Once 2.10 support is dropped, SBT macros will be able to exploit
the new reflection APIs in 2.11 to avoid the need for casting
to compiler internals, which aren't governed by binary compatibility.
This has been prototyped by @xeno-by: https://github.com/sbt/sbt/pull/1121
---
 util/appmacro/src/main/scala/sbt/appmacro/ContextUtil.scala   | 4 ++++
 util/appmacro/src/main/scala/sbt/appmacro/KListBuilder.scala  | 4 ++++
 util/appmacro/src/main/scala/sbt/appmacro/TupleNBuilder.scala | 4 ++++
 3 files changed, 12 insertions(+)

diff --git a/util/appmacro/src/main/scala/sbt/appmacro/ContextUtil.scala b/util/appmacro/src/main/scala/sbt/appmacro/ContextUtil.scala
index 381674e47..c0c849fab 100644
--- a/util/appmacro/src/main/scala/sbt/appmacro/ContextUtil.scala
+++ b/util/appmacro/src/main/scala/sbt/appmacro/ContextUtil.scala
@@ -32,12 +32,16 @@ object ContextUtil {
 	def unexpectedTree[C <: Context](tree: C#Tree): Nothing = sys.error("Unexpected macro application tree (" + tree.getClass + "): " + tree)
 }
 
+// TODO 2.11 Remove this after dropping 2.10.x support.
+private object HasCompat { val compat = ??? }; import HasCompat._
+
 /** Utility methods for macros.  Several methods assume that the context's universe is a full compiler (`scala.tools.nsc.Global`).
 * This is not thread safe due to the underlying Context and related data structures not being thread safe.
 * Use `ContextUtil[c.type](c)` to construct. */
 final class ContextUtil[C <: Context](val ctx: C)
 {
 		import ctx.universe.{Apply=>ApplyTree,_}
+		import compat._
 
 	val powerContext = ctx.asInstanceOf[reflect.macros.runtime.Context]
 	val global: powerContext.universe.type = powerContext.universe
diff --git a/util/appmacro/src/main/scala/sbt/appmacro/KListBuilder.scala b/util/appmacro/src/main/scala/sbt/appmacro/KListBuilder.scala
index 81d3be06f..d9dbebe42 100644
--- a/util/appmacro/src/main/scala/sbt/appmacro/KListBuilder.scala
+++ b/util/appmacro/src/main/scala/sbt/appmacro/KListBuilder.scala
@@ -9,11 +9,15 @@ package appmacro
 /** A `TupleBuilder` that uses a KList as the tuple representation.*/
 object KListBuilder extends TupleBuilder
 {
+	// TODO 2.11 Remove this after dropping 2.10.x support.
+	private object HasCompat { val compat = ??? }; import HasCompat._
+
 	def make(c: Context)(mt: c.Type, inputs: Inputs[c.universe.type]): BuilderResult[c.type] = new BuilderResult[c.type]
 	{
 		val ctx: c.type = c
 		val util = ContextUtil[c.type](c)
 			import c.universe.{Apply=>ApplyTree,_}
+			import compat._
 			import util._
 
 		val knilType = c.typeOf[KNil]
diff --git a/util/appmacro/src/main/scala/sbt/appmacro/TupleNBuilder.scala b/util/appmacro/src/main/scala/sbt/appmacro/TupleNBuilder.scala
index 871932b20..28fa581a4 100644
--- a/util/appmacro/src/main/scala/sbt/appmacro/TupleNBuilder.scala
+++ b/util/appmacro/src/main/scala/sbt/appmacro/TupleNBuilder.scala
@@ -14,10 +14,14 @@ object TupleNBuilder extends TupleBuilder
 	final val MaxInputs = 11
 	final val TupleMethodName = "tuple"
 
+	// TODO 2.11 Remove this after dropping 2.10.x support.
+	private object HasCompat { val compat = ??? }; import HasCompat._
+
 	def make(c: Context)(mt: c.Type, inputs: Inputs[c.universe.type]): BuilderResult[c.type] = new BuilderResult[c.type]
 	{
 		val util = ContextUtil[c.type](c)
 			import c.universe.{Apply=>ApplyTree,_}
+			import compat._
 			import util._
 
 		val global: Global = c.universe.asInstanceOf[Global]