Use an explicit 'this' parameter instead of 'This' nodes.

pkg/compiler/lib/src/cps_ir/cps_ir_nodes_sexpr.dart

Index: pkg/compiler/lib/src/cps_ir/cps_ir_nodes_sexpr.dart
diff --git a/pkg/compiler/lib/src/cps_ir/cps_ir_nodes_sexpr.dart b/pkg/compiler/lib/src/cps_ir/cps_ir_nodes_sexpr.dart
index 34cd076d3c0941f0a6eec0baa1e8520d82735286..9a3bd3e376ae78e5a948bd4f027655a4f291a59c 100644
--- a/pkg/compiler/lib/src/cps_ir/cps_ir_nodes_sexpr.dart
+++ b/pkg/compiler/lib/src/cps_ir/cps_ir_nodes_sexpr.dart
@@ -46,11 +46,15 @@ class SExpressionStringifier extends Indentation implements Visitor<String> {
     return decorator(node, s);
   }
 
+  String visitThisParameter(Parameter thisParameter) {
+    return thisParameter == null ? '' : visit(thisParameter) + ' ';
+  }

[asgerf, 2015/03/18 13:28:25]

I think we try to avoid `visitXXX` names for methods that don't actually
override a visitor method.

[sra1, 2015/03/19 10:42:51]

Done.

   String visitFunctionDefinition(FunctionDefinition node) {
     String name = node.element.name;
+    String thisName = visitThisParameter(node.thisParameter);
     String parameters = node.parameters.map(visit).join(' ');
     String body = visit(node.body);
-    return '$indentation(FunctionDefinition $name ($parameters) return\n'
+    return '$indentation(FunctionDefinition $name $thisName($parameters) return\n'

[asgerf, 2015/03/18 13:28:25]

Long line

[sra1, 2015/03/19 10:42:51]

Done.

         '$body)';
   }
 
@@ -68,6 +72,7 @@ class SExpressionStringifier extends Indentation implements Visitor<String> {
   String visitConstructorDefinition(ConstructorDefinition node) {
     String name = node.element.name;
     if (name != '') name = '$name ';
+    String thisName = visitThisParameter(node.thisParameter);
     String parameters = node.parameters.map(visit).join(' ');
     if (node.body != null) {
       String initializers = indentBlock(() {
@@ -80,10 +85,10 @@ class SExpressionStringifier extends Indentation implements Visitor<String> {
         });
       });
       String body = visit(node.body);
-      return '$indentation(ConstructorDefinition $name($parameters) return'
+      return '$indentation(ConstructorDefinition $name$thisName($parameters) return'

[asgerf, 2015/03/18 13:28:25]

Long line

[sra1, 2015/03/19 10:42:51]

Done.

           ' (\n$initializers)\n$body)';
     } else {
-      return '$indentation(ConstructorDefinition $name($parameters) return)';
+      return '$indentation(ConstructorDefinition $name$thisName($parameters) return)';
     }
   }
 
@@ -443,7 +448,9 @@ class _Namer {
   }
 
   String getName(Node node) {
-    assert(_names.containsKey(node));
-    return _names[node];
+    //assert(_names.containsKey(node));
+    //return _names[node];
+    if (_names.containsKey(node)) return _names[node];
+    return '<<${node}>>';

[asgerf, 2015/03/18 13:28:25]

It's not clear if this is leftover debugging code or intentional. In any case,
there shouldn't be outcommented code.

[sra1, 2015/03/19 10:42:51]

I have reverted this change, and added a TODO to make the printer produce
something for malformed terms to assist in the debugging of malformed terms.

   }
 }