Prune some internal objects' prototypes.

src/messages.js

Index: src/messages.js
diff --git a/src/messages.js b/src/messages.js
index a6305072b73b080da8403ff2477dda71d8d69555..8ea31eaadb74d169c1afcd47f9f29b51a770b7da 100644
--- a/src/messages.js
+++ b/src/messages.js
@@ -1,4 +1,4 @@
-// Copyright 2006-2008 the V8 project authors. All rights reserved.
+// Copyright 2011 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
@@ -57,7 +57,7 @@ function FormatString(format, message) {
   for (var i = 0; i < format.length; i++) {
     var str = format[i];
     for (arg_num = 0; arg_num < kReplacementMarkers.length; arg_num++) {
-      if (format[i] !== kReplacementMarkers[arg_num]) continue;
+      if (str !== kReplacementMarkers[arg_num]) continue;
       try {
         str = ToDetailString(args[arg_num]);
       } catch (e) {
@@ -100,7 +100,8 @@ function ToStringCheckErrorObject(obj) {
 
 
 function ToDetailString(obj) {
-  if (obj != null && IS_OBJECT(obj) && obj.toString === $Object.prototype.toString) {
+  if (obj != null && IS_OBJECT(obj) &&
+      obj.toString === $Object.prototype.toString) {
     var constructor = obj.constructor;
     if (!constructor) return ToStringCheckErrorObject(obj);
     var constructorName = constructor.name;
@@ -560,6 +561,7 @@ function SourceLocation(script, position, line, column, start, end) {
   this.end = end;
 }
 
+SourceLocation.prototype.__proto__ = null;
 
 const kLineLengthLimit = 78;
 
@@ -649,6 +651,7 @@ function SourceSlice(script, from_line, to_line, from_position, to_position) {
   this.to_position = to_position;
 }
 
+SourceSlice.prototype.__proto__ = null;
 
 /**
  * Get the source text for a SourceSlice
@@ -716,23 +719,28 @@ function CallSite(receiver, fun, pos) {
   this.pos = pos;
 }
 
+CallSite.prototype.__proto__ = null;
+
 CallSite.prototype.getThis = function () {
   return this.receiver;
 };
 
 CallSite.prototype.getTypeName = function () {
   var constructor = this.receiver.constructor;
-  if (!constructor)
+  if (!constructor) {
     return %_CallFunction(this.receiver, ObjectToString);
+  }
   var constructorName = constructor.name;
-  if (!constructorName)
+  if (!constructorName) {
     return %_CallFunction(this.receiver, ObjectToString);
+  }
   return constructorName;
 };
 
 CallSite.prototype.isToplevel = function () {
-  if (this.receiver == null)
+  if (this.receiver == null) {
     return true;
+  }
   return IS_GLOBAL(this.receiver);
 };
 
@@ -765,8 +773,9 @@ CallSite.prototype.getFunctionName = function () {
   }
   // Maybe this is an evaluation?
   var script = %FunctionGetScript(this.fun);
-  if (script && script.compilation_type == COMPILATION_TYPE_EVAL)
+  if (script && script.compilation_type == COMPILATION_TYPE_EVAL) {
     return "eval";
+  }
   return null;
 };
 
@@ -788,13 +797,15 @@ CallSite.prototype.getMethodName = function () {
         this.receiver.__lookupSetter__(prop) === this.fun ||
         (!this.receiver.__lookupGetter__(prop) && this.receiver[prop] === this.fun)) {
       // If we find more than one match bail out to avoid confusion.
-      if (name)
+      if (name) {
         return null;
+      }
       name = prop;
     }
   }
-  if (name)
+  if (name) {
     return name;
+  }
   return null;
 };
 
@@ -804,8 +815,9 @@ CallSite.prototype.getFileName = function () {
 };
 
 CallSite.prototype.getLineNumber = function () {
-  if (this.pos == -1)
+  if (this.pos == -1) {
     return null;
+  }
   var script = %FunctionGetScript(this.fun);
   var location = null;
   if (script) {
@@ -815,8 +827,9 @@ CallSite.prototype.getLineNumber = function () {
 };
 
 CallSite.prototype.getColumnNumber = function () {
-  if (this.pos == -1)
+  if (this.pos == -1) {
     return null;
+  }
   var script = %FunctionGetScript(this.fun);
   var location = null;
   if (script) {
@@ -836,15 +849,17 @@ CallSite.prototype.getPosition = function () {
 
 CallSite.prototype.isConstructor = function () {
   var constructor = this.receiver ? this.receiver.constructor : null;
-  if (!constructor)
+  if (!constructor) {
     return false;
+  }
   return this.fun === constructor;
 };
 
 function FormatEvalOrigin(script) {
   var sourceURL = script.nameOrSourceURL();
-  if (sourceURL)
+  if (sourceURL) {
     return sourceURL;
+  }
 
   var eval_origin = "eval at ";
   if (script.eval_from_function_name) {
@@ -1042,8 +1057,9 @@ function DefineError(f) {
 function captureStackTrace(obj, cons_opt) {
   var stackTraceLimit = $Error.stackTraceLimit;
   if (!stackTraceLimit || !IS_NUMBER(stackTraceLimit)) return;
-  if (stackTraceLimit < 0 || stackTraceLimit > 10000)
+  if (stackTraceLimit < 0 || stackTraceLimit > 10000) {
     stackTraceLimit = 10000;
+  }
   var raw_stack = %CollectStackTrace(cons_opt
                                      ? cons_opt
                                      : captureStackTrace, stackTraceLimit);
@@ -1117,8 +1133,10 @@ function errorToString() {
   } catch(e) {
     // If this error message was encountered already return the empty
     // string for it instead of recursively formatting it.
-    if (isCyclicErrorMarker(e)) return '';
-    else throw e;
+    if (isCyclicErrorMarker(e)) {
+      return '';
+    }
+    throw e;
   }
 }