Fully support try/catch.

frog/leg/ssa/codegen.dart

 // Copyright (c) 2012, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 class SsaCodeGeneratorTask extends CompilerTask {
   SsaCodeGeneratorTask(Compiler compiler) : super(compiler);
   String get name() => 'SSA code generator';
 
   String generate(WorkItem work, HGraph graph) {
     return measure(() {
@@ skipping 341 matching lines @@
 
   visitTry(HTry node) {
     addIndentation();
     buffer.add('try {\n');
     indent++;
     List<HBasicBlock> successors = node.block.successors;
     visitBasicBlock(successors[0]);
     indent--;
 
     if (node.finallyBlock != successors[1]) {
+      // Printing the catch part.
       addIndentation();
-      buffer.add('} catch (e) {\n');
+      String name = temporary(node.exception);
+      parameterNames[node.exception.element] = name;
+      buffer.add('} catch ($name) {\n');
       indent++;
+      visitBasicBlock(successors[1]);
+      parameterNames.remove(node.exception.element);
+      indent--;
     }
 
-    for (int i = 1; i < successors.length - 1; i++) {
-      // TODO(ngeoffray): add the type check.
-      visitBasicBlock(successors[i]);
-    }
-
-    if (node.finallyBlock == null) {
-      // TODO(ngeoffray): add the type check.
-      visitBasicBlock(successors[successors.length - 1]);
-    } else {
+    if (node.finallyBlock != null) {
       addIndentation();
       buffer.add('} finally {\n');
       indent++;
       visitBasicBlock(node.finallyBlock);
     }
     indent--;
     addIndentation();
     buffer.add('}\n');
   }
 
@@ skipping 406 matching lines @@
     if (node.typeExpression.name == const SourceString('Object')) {
       // TODO(ahe): This probably belongs in the constant folder.
       if (node.expression.generateAtUseSite()) {
         buffer.add('((');
         visit(node.expression);
         buffer.add('), true)');
       } else {
         buffer.add('true');
       }
     } else {
-      buffer.add('((');
+      buffer.add('(!!(');
       use(node.expression);
       buffer.add(').');
       buffer.add(compiler.namer.operatorIs(node.typeExpression));
-      buffer.add(' === true)');
+      buffer.add(')');
     }
   }
 }
 
 class SsaOptimizedCodeGenerator extends SsaCodeGenerator {
   final List<HTypeGuard> guards;
   int state = 0;
 
   SsaOptimizedCodeGenerator(compiler, work, buffer, parameters, parameterNames)
     : super(compiler, work, buffer, parameters, parameterNames),
@@ skipping 331 matching lines @@
       startBailoutSwitch();
     }
   }
 
   void endElse(HIf node) {
     if (node.elseBlock.hasBailouts()) {
       endBailoutSwitch();
     }
   }
 }