SI-6963 Add version to -Xmigration

Adds an optional version parameter to the -Xmigration compiler setting.
Doing -Xmigration without version number behaves as it used to by
dumping every possible migration warning.

This commit adds a ScalaVersion class (plus ancillary stuff), and a
ScalaVersionSetting.

11 files changed, 71 insertions, 6 deletions

diff --git a/test/files/neg/t6963.check b/test/files/neg/t6963.check
deleted file mode 100644
index 41cb796b0b..0000000000
--- a/test/files/neg/t6963.check
+++ /dev/null
@@ -1,2 +0,0 @@
-error: -Xmigration is deprecated: This setting is no longer useful and will be removed. Please remove it from your build.
-one error found
diff --git a/test/files/neg/t6963.flags b/test/files/neg/t6963.flags
deleted file mode 100644
index 0b6d71496a..0000000000
--- a/test/files/neg/t6963.flags
+++ /dev/null
@@ -1 +0,0 @@
--Xmigration -deprecation -Xfatal-warnings
\ No newline at end of file
diff --git a/test/files/neg/t6963.scala b/test/files/neg/t6963.scala
deleted file mode 100644
index 4da52764f5..0000000000
--- a/test/files/neg/t6963.scala
+++ /dev/null
@@ -1,3 +0,0 @@
-
-object test {
-}
diff --git a/test/files/neg/t6963a.check b/test/files/neg/t6963a.check
new file mode 100644
index 0000000000..159896fd10
--- /dev/null
+++ b/test/files/neg/t6963a.check
@@ -0,0 +1,5 @@
+t6963a.scala:4: error: method scanRight in trait TraversableLike has changed semantics in version 2.9.0:
+The behavior of `scanRight` has changed. The previous behavior can be reproduced with scanRight.reverse.
+  List(1,2,3,4,5).scanRight(0)(_+_)
+                  ^
+one error found
diff --git a/test/files/neg/t6963a.flags b/test/files/neg/t6963a.flags
new file mode 100644
index 0000000000..4c61ed9430
--- /dev/null
+++ b/test/files/neg/t6963a.flags
@@ -0,0 +1 @@
+-Xfatal-warnings -Xmigration:2.7
diff --git a/test/files/neg/t6963a.scala b/test/files/neg/t6963a.scala
new file mode 100644
index 0000000000..b3366b2557
--- /dev/null
+++ b/test/files/neg/t6963a.scala
@@ -0,0 +1,5 @@
+object Test {
+  import scala.collection.mutable._
+  
+  List(1,2,3,4,5).scanRight(0)(_+_)
+}
diff --git a/test/files/neg/t6963b.check b/test/files/neg/t6963b.check
new file mode 100644
index 0000000000..7e205a41d0
--- /dev/null
+++ b/test/files/neg/t6963b.check
@@ -0,0 +1,13 @@
+t6963b.scala:2: error: An Array will no longer match as Seq[_].
+  def f1(x: Any) = x.isInstanceOf[Seq[_]]
+                                 ^
+t6963b.scala:4: error: An Array will no longer match as Seq[_].
+    case _: Seq[_]  => true
+          ^
+t6963b.scala:16: error: An Array will no longer match as Seq[_].
+    case (Some(_: Seq[_]), Nil, _)        => 1
+                ^
+t6963b.scala:17: error: An Array will no longer match as Seq[_].
+    case (None, List(_: List[_], _), _)   => 2
+                    ^
+four errors found
diff --git a/test/files/neg/t6963b.flags b/test/files/neg/t6963b.flags
new file mode 100644
index 0000000000..83caa2b147
--- /dev/null
+++ b/test/files/neg/t6963b.flags
@@ -0,0 +1 @@
+-Xmigration:2.7 -Xfatal-warnings
\ No newline at end of file
diff --git a/test/files/neg/t6963b.scala b/test/files/neg/t6963b.scala
new file mode 100644
index 0000000000..3cfa8f0dca
--- /dev/null
+++ b/test/files/neg/t6963b.scala
@@ -0,0 +1,20 @@
+object Test {
+  def f1(x: Any) = x.isInstanceOf[Seq[_]]
+  def f2(x: Any) = x match {
+    case _: Seq[_]  => true
+    case _          => false
+  }
+
+  def f3(x: Any) = x match {
+    case _: Array[_]  => true
+    case _            => false
+  }
+  
+  def f4(x: Any) = x.isInstanceOf[Traversable[_]]
+  
+  def f5(x1: Any, x2: Any, x3: AnyRef) = (x1, x2, x3) match {
+    case (Some(_: Seq[_]), Nil, _)        => 1
+    case (None, List(_: List[_], _), _)   => 2
+    case _                                => 3
+  }
+}
diff --git a/test/files/pos/t6963c.flags b/test/files/pos/t6963c.flags
new file mode 100644
index 0000000000..4d6e04914f
--- /dev/null
+++ b/test/files/pos/t6963c.flags
@@ -0,0 +1 @@
+-Xmigration:2.9 -Xfatal-warnings
\ No newline at end of file
diff --git a/test/files/pos/t6963c.scala b/test/files/pos/t6963c.scala
new file mode 100644
index 0000000000..0b6b5c757f
--- /dev/null
+++ b/test/files/pos/t6963c.scala
@@ -0,0 +1,25 @@
+object Test {
+  def f1(x: Any) = x.isInstanceOf[Seq[_]]
+  def f2(x: Any) = x match {
+    case _: Seq[_]  => true
+    case _          => false
+  }
+
+  def f3(x: Any) = x match {
+    case _: Array[_]  => true
+    case _            => false
+  }
+  
+  def f4(x: Any) = x.isInstanceOf[Traversable[_]]
+  
+  def f5(x1: Any, x2: Any, x3: AnyRef) = (x1, x2, x3) match {
+    case (Some(_: Seq[_]), Nil, _)        => 1
+    case (None, List(_: List[_], _), _)   => 2
+    case _                                => 3
+  }
+
+  def f5: Unit = {
+    import scala.collection.mutable._
+    List(1,2,3,4,5).scanRight(0)(_+_)
+  }
+}