SI-7622 Clean Up Phase Assembly

Let optimiser components and continuations plugin opt-out
when required flags are not set.

Wasted time on a whitespace error in check file, so let
--debug dump the processed check file and its diff.

1 files changed, 40 insertions, 0 deletions

diff --git a/test/files/neg/t7622-cyclic-dependency/ThePlugin.scala b/test/files/neg/t7622-cyclic-dependency/ThePlugin.scala
new file mode 100644
index 0000000000..7a905ae32d
--- /dev/null
+++ b/test/files/neg/t7622-cyclic-dependency/ThePlugin.scala
@@ -0,0 +1,40 @@
+package scala.test.plugins
+
+import scala.tools.nsc
+import nsc.Global
+import nsc.Phase
+import nsc.plugins.Plugin
+import nsc.plugins.PluginComponent
+
+class ThePlugin(val global: Global) extends Plugin {
+  import global._
+
+  val name = "cyclicdependency"
+  val description = "Declares two phases that have a cyclic dependency"
+  val components = List[PluginComponent](thePhase1,thePhase2)
+  
+  private object thePhase1 extends PluginComponent {
+    val global = ThePlugin.this.global
+
+    val runsAfter = List[String]("tailcalls","cyclicdependency2")
+
+    val phaseName = ThePlugin.this.name + "1"
+
+    def newPhase(prev: Phase) = new ThePhase(prev, phaseName)
+  }
+  
+  private object thePhase2 extends PluginComponent {
+    val global = ThePlugin.this.global
+
+    val runsAfter = List[String]("dce","cyclicdependency1")
+
+    val phaseName = ThePlugin.this.name + "2"
+
+    def newPhase(prev: Phase) = new ThePhase(prev, phaseName)
+  }
+  
+  private class ThePhase(prev: Phase, val name: String) extends Phase(prev) {
+    def run {}
+  }
+}
+