1 files changed, 49 insertions, 0 deletions
diff --git a/src/compiler/scala/tools/nsc/backend/icode/ExceptionHandlers.scala b/src/compiler/scala/tools/nsc/backend/icode/ExceptionHandlers.scala
new file mode 100644
index 0000000000..126e20ebef
--- /dev/null
+++ b/src/compiler/scala/tools/nsc/backend/icode/ExceptionHandlers.scala
@@ -0,0 +1,49 @@
+/* NSC -- new scala compiler
+ * Copyright 2005 LAMP/EPFL
+ * @author  Martin Odersky
+ */
+
+// $Id$
+
+package scala.tools.nsc.backend.icode;
+
+import scala.collection.mutable.HashMap;
+import scala.collection.mutable.HashSet;
+
+/**
+ * Exception handlers are pieces of code that `handle' exceptions on
+ * the covered basic blocks. Since Scala's exception handling uses
+ * pattern matching instead of just class names to identify handlers,
+ * all our handlers will catch `Throwable' and rely on proper ordering
+ * in the generated code to preserve nesting.
+ */
+trait ExceptionHandlers: ICodes {
+  import global.{Symbol, NoSymbol};
+
+  class ExceptionHandler(val method: IMethod, label: String, val cls: Symbol) {
+    private var coveredBlocks: List[BasicBlock] = Nil;
+    private var _startBlock: BasicBlock = _;
+    var finalizer: Finalizer = _;
+
+    def setStartBlock(b: BasicBlock) = _startBlock = b;
+    def startBlock = _startBlock;
+
+    def addBlock(b: BasicBlock): ExceptionHandler = {
+      coveredBlocks = b :: coveredBlocks;
+      this
+    }
+
+    def covered: List[BasicBlock] = coveredBlocks;
+
+    override def toString() = "exh_" + label + "(" + cls.simpleName + ")";
+  }
+
+  class Finalizer(method: IMethod, label: String) extends ExceptionHandler(method, label, NoSymbol) {
+    override def toString() = "finalizer_" + label;
+  }
+
+  object NoFinalizer extends Finalizer(null, "<no finalizer>") {
+    override def startBlock: BasicBlock = error("NoFinalizer cannot have a start block.");
+    override def setStartBlock(b: BasicBlock): Unit = error("NoFinalizer cannot have a start block.");
+  }
+}