CPS implementation of throw and rethrow.

pkg/compiler/lib/src/tree_ir/tree_ir_nodes.dart

Index: pkg/compiler/lib/src/tree_ir/tree_ir_nodes.dart
diff --git a/pkg/compiler/lib/src/tree_ir/tree_ir_nodes.dart b/pkg/compiler/lib/src/tree_ir/tree_ir_nodes.dart
index 2d538659ab78b9e24b48b37491313081300ad749..5d2e74669f712643e2c5ed6f2787563bf228ab1c 100644
--- a/pkg/compiler/lib/src/tree_ir/tree_ir_nodes.dart
+++ b/pkg/compiler/lib/src/tree_ir/tree_ir_nodes.dart
@@ -582,6 +582,35 @@ class Return extends Statement {
   accept1(StatementVisitor1 visitor, arg) => visitor.visitReturn(this, arg);
 }
 
+/// A throw statement.
+///
+/// In the Tree IR, throw is a statement (like JavaScript and unlike Dart).
+class Throw extends Statement {
+  Expression value;
+
+  Statement get next => null;
+  void set next(Statement s) => throw 'UNREACHABLE';
+
+  Throw(this.value);
+
+  accept(StatementVisitor visitor) => visitor.visitThrow(this);
+  accept1(StatementVisitor1 visitor, arg) => visitor.visitThrow(this, arg);
+}
+
+/// A rethrow exit from the function.
+///
+/// Rethrow can only occur nested inside a catch block.  It implicitly throws
+/// the block's caught exception value without changing the caught stack trace.
+class Rethrow extends Statement {
+  Statement get next => null;
+  void set next(Statement s) => throw 'UNREACHABLE';
+
+  Rethrow();
+
+  accept(StatementVisitor visitor) => visitor.visitRethrow(this);
+  accept1(StatementVisitor1 visitor, arg) => visitor.visitRethrow(this, arg);
+}
+
 /**
  * A conditional branch based on the true value of an [Expression].
  */
@@ -948,6 +977,8 @@ abstract class StatementVisitor<S> {
   S visitStatement(Statement node) => node.accept(this);
   S visitLabeledStatement(LabeledStatement node);
   S visitReturn(Return node);
+  S visitThrow(Throw node);
+  S visitRethrow(Rethrow node);
   S visitBreak(Break node);
   S visitContinue(Continue node);
   S visitIf(If node);
@@ -963,6 +994,8 @@ abstract class StatementVisitor1<S, A> {
   S visitStatement(Statement node, A arg) => node.accept1(this, arg);
   S visitLabeledStatement(LabeledStatement node, A arg);
   S visitReturn(Return node, A arg);
+  S visitThrow(Throw node, A arg);
+  S visitRethrow(Rethrow node, A arg);
   S visitBreak(Break node, A arg);
   S visitContinue(Continue node, A arg);
   S visitIf(If node, A arg);
@@ -1094,6 +1127,12 @@ abstract class RecursiveVisitor implements StatementVisitor, ExpressionVisitor {
     visitExpression(node.value);
   }
 
+  visitThrow(Throw node) {
+    visitExpression(node.value);
+  }
+
+  visitRethrow(Rethrow node) {}
+
   visitBreak(Break node) {}
 
   visitContinue(Continue node) {}
@@ -1273,6 +1312,13 @@ class RecursiveTransformer extends Transformer {
     return node;
   }
 
+  visitThrow(Throw node) {
+    node.value = visitExpression(node.value);
+    return node;
+  }
+
+  visitRethrow(Rethrow node) => node;
+
   visitBreak(Break node) => node;
 
   visitContinue(Continue node) => node;