Lock the prototype of internal classes.

src/messages.js

 // 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:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 114 matching lines @@
   e.type = type;
   e.arguments = args;
   return e;
 }
 
 
 /**
  * Setup the Script function and constructor.
  */
 %FunctionSetInstanceClassName(Script, 'Script');
-%SetProperty(Script.prototype, 'constructor', Script, DONT_ENUM);
+%SetProperty(Script.prototype, 'constructor', Script,
+             DONT_ENUM | DONT_DELETE | READ_ONLY);
 %SetCode(Script, function(x) {
   // Script objects can only be created by the VM.
   throw new $Error("Not supported");
 });
 
 
 // Helper functions; called from the runtime system.
 function FormatMessage(message) {
   if (kMessages === 0) {
     kMessages = {
@@ skipping 98 matching lines @@
       strict_reserved_word:         ["Use of future reserved word in strict mode"],
       strict_delete:                ["Delete of an unqualified identifier in strict mode."],
       strict_delete_property:       ["Cannot delete property '", "%0", "' of ", "%1"],
       strict_const:                 ["Use of const in strict mode."],
       strict_function:              ["In strict mode code, functions can only be declared at top level or immediately within another function." ],
       strict_read_only_property:    ["Cannot assign to read only property '", "%0", "' of ", "%1"],
       strict_cannot_assign:         ["Cannot assign to read only '", "%0", "' in strict mode"],
       strict_poison_pill:           ["'caller', 'callee', and 'arguments' properties may not be accessed on strict mode functions or the arguments objects for calls to them"],
       strict_caller:                ["Illegal access to a strict mode caller function."],
       unprotected_let:              ["Illegal let declaration in unprotected statement context."],
+      __proto__: null
     };
   }
   var message_type = %MessageGetType(message);
   var format = kMessages[message_type];
   if (!format) return "<unknown message " + message_type + ">";
   return FormatString(format, message);
 }
 
 
 function GetLineNumber(message) {
@@ skipping 46 matching lines @@
 function MakeError(type, args) {
   return MakeGenericError($Error, type, args);
 }
 
 /**
  * Find a line number given a specific source position.
  * @param {number} position The source position.
  * @return {number} 0 if input too small, -1 if input too large,
        else the line number.
  */
-Script.prototype.lineFromPosition = function(position) {
+function ScriptLineFromPosition(position) {
   var lower = 0;
   var upper = this.lineCount() - 1;
   var line_ends = this.line_ends;
 
   // We'll never find invalid positions so bail right away.
   if (position > line_ends[upper]) {
     return -1;
   }
 
   // This means we don't have to safe-guard indexing line_ends[i - 1].
@@ skipping 18 matching lines @@
 }
 
 /**
  * Get information on a specific source position.
  * @param {number} position The source position
  * @param {boolean} include_resource_offset Set to true to have the resource
  *     offset added to the location
  * @return {SourceLocation}
  *     If line is negative or not in the source null is returned.
  */
-Script.prototype.locationFromPosition = function (position,
-                                                  include_resource_offset) {
+function ScriptLocationFromPosition(position,
+                                    include_resource_offset) {
   var line = this.lineFromPosition(position);
   if (line == -1) return null;
 
   // Determine start, end and column.
   var line_ends = this.line_ends;
   var start = line == 0 ? 0 : line_ends[line - 1] + 1;
   var end = line_ends[line];
-  if (end > 0 && %_CallFunction(this.source, end - 1, StringCharAt) == '\r') end--;
+  if (end > 0 && %_CallFunction(this.source, end - 1, StringCharAt) == '\r') {
+    end--;
+  }
   var column = position - start;
 
   // Adjust according to the offset within the resource.
   if (include_resource_offset) {
     line += this.line_offset;
     if (line == this.line_offset) {
       column += this.column_offset;
     }
   }
 
   return new SourceLocation(this, position, line, column, start, end);
 };
 
 
 /**
  * Get information on a specific source line and column possibly offset by a
  * fixed source position. This function is used to find a source position from
  * a line and column position. The fixed source position offset is typically
  * used to find a source position in a function based on a line and column in
  * the source for the function alone. The offset passed will then be the
  * start position of the source for the function within the full script source.
  * @param {number} opt_line The line within the source. Default value is 0
  * @param {number} opt_column The column in within the line. Default value is 0
  * @param {number} opt_offset_position The offset from the begining of the
- *     source from where the line and column calculation starts. Default value is 0
+ *     source from where the line and column calculation starts.
+ *     Default value is 0
  * @return {SourceLocation}
  *     If line is negative or not in the source null is returned.
  */
-Script.prototype.locationFromLine = function (opt_line, opt_column, opt_offset_position) {
+function ScriptLocationFromLine(opt_line, opt_column, opt_offset_position) {
   // Default is the first line in the script. Lines in the script is relative
   // to the offset within the resource.
   var line = 0;
   if (!IS_UNDEFINED(opt_line)) {
     line = opt_line - this.line_offset;
   }
 
   // Default is first column. If on the first line add the offset within the
   // resource.
   var column = opt_column || 0;
@@ skipping 21 matching lines @@
 /**
  * Get a slice of source code from the script. The boundaries for the slice is
  * specified in lines.
  * @param {number} opt_from_line The first line (zero bound) in the slice.
  *     Default is 0
  * @param {number} opt_to_column The last line (zero bound) in the slice (non
  *     inclusive). Default is the number of lines in the script
  * @return {SourceSlice} The source slice or null of the parameters where
  *     invalid
  */
-Script.prototype.sourceSlice = function (opt_from_line, opt_to_line) {
+function ScriptSourceSlice(opt_from_line, opt_to_line) {
   var from_line = IS_UNDEFINED(opt_from_line) ? this.line_offset : opt_from_line;
   var to_line = IS_UNDEFINED(opt_to_line) ? this.line_offset + this.lineCount() : opt_to_line
 
   // Adjust according to the offset within the resource.
   from_line -= this.line_offset;
   to_line -= this.line_offset;
   if (from_line < 0) from_line = 0;
   if (to_line > this.lineCount()) to_line = this.lineCount();
 
   // Check parameters.
   if (from_line >= this.lineCount() ||
       to_line < 0 ||
       from_line > to_line) {
     return null;
   }
 
   var line_ends = this.line_ends;
   var from_position = from_line == 0 ? 0 : line_ends[from_line - 1] + 1;
   var to_position = to_line == 0 ? 0 : line_ends[to_line - 1] + 1;
 
   // Return a source slice with line numbers re-adjusted to the resource.
   return new SourceSlice(this, from_line + this.line_offset, to_line + this.line_offset,
                          from_position, to_position);
 }
 
 
-Script.prototype.sourceLine = function (opt_line) {
+function ScriptSourceLine(opt_line) {
   // Default is the first line in the script. Lines in the script are relative
   // to the offset within the resource.
   var line = 0;
   if (!IS_UNDEFINED(opt_line)) {
     line = opt_line - this.line_offset;
   }
 
   // Check parameter.
   if (line < 0 || this.lineCount() <= line) {
     return null;
   }
 
   // Return the source line.
   var line_ends = this.line_ends;
   var start = line == 0 ? 0 : line_ends[line - 1] + 1;
   var end = line_ends[line];
   return %_CallFunction(this.source, start, end, StringSubstring);
 }
 
 
 /**
  * Returns the number of source lines.
  * @return {number}
  *     Number of source lines.
  */
-Script.prototype.lineCount = function() {
+function ScriptLineCount() {
   // Return number of source lines.
   return this.line_ends.length;
 };
 
 
 /**
  * Returns the name of script if available, contents of sourceURL comment
  * otherwise. See
  * http://fbug.googlecode.com/svn/branches/firebug1.1/docs/ReleaseNotes_1.1.txt
  * for details on using //@ sourceURL comment to identify scritps that don't
  * have name.
  *
  * @return {?string} script name if present, value for //@ sourceURL comment
  * otherwise.
  */
-Script.prototype.nameOrSourceURL = function() {
-  if (this.name)
+function ScriptNameOrSourceURL() {
+  if (this.name) {
     return this.name;
+  }
   // TODO(608): the spaces in a regexp below had to be escaped as \040
   // because this file is being processed by js2c whose handling of spaces
   // in regexps is broken. Also, ['"] are excluded from allowed URLs to
   // avoid matches against sources that invoke evals with sourceURL.
   // A better solution would be to detect these special comments in
   // the scanner/parser.
   var source = ToString(this.source);
   var sourceUrlPos = %StringIndexOf(source, "sourceURL=", 0);
   if (sourceUrlPos > 4) {
     var sourceUrlPattern =
         /\/\/@[\040\t]sourceURL=[\040\t]*([^\s\'\"]*)[\040\t]*$/gm;
     // Don't reuse lastMatchInfo here, so we create a new array with room
     // for four captures (array with length one longer than the index
     // of the fourth capture, where the numbering is zero-based).
     var matchInfo = new InternalArray(CAPTURE(3) + 1);
     var match =
         %_RegExpExec(sourceUrlPattern, source, sourceUrlPos - 4, matchInfo);
     if (match) {
       return SubString(source, matchInfo[CAPTURE(2)], matchInfo[CAPTURE(3)]);
     }
   }
   return this.name;
 }
 
 
+SetupLockedPrototype(Script,
+  $Array("source", "name", "line_ends", "line_offset", "column_offset"),
+  $Array(
+    "lineFromPosition", ScriptLineFromPosition,
+    "locationFromPosition", ScriptLocationFromPosition,
+    "locationFromLine", ScriptLocationFromLine,
+    "sourceSlice", ScriptSourceSlice,
+    "sourceLine", ScriptSourceLine,
+    "lineCount", ScriptLineCount,
+    "nameOrSourceURL", ScriptNameOrSourceURL
+  )
+);
+
+
 /**
  * Class for source location. A source location is a position within some
  * source with the following properties:
  *   script   : script object for the source
  *   line     : source line number
  *   column   : source column within the line
  *   position : position within the source
  *   start    : position of start of source context (inclusive)
  *   end      : position of end of source context (not inclusive)
  * Source text for the source context is the character interval [start, end[. In
@@ skipping 10 matching lines @@
  */
 function SourceLocation(script, position, line, column, start, end) {
   this.script = script;
   this.position = position;
   this.line = line;
   this.column = column;
   this.start = start;
   this.end = end;
 }
 
-SourceLocation.prototype.__proto__ = null;
-
 const kLineLengthLimit = 78;
 
 /**
  * Restrict source location start and end positions to make the source slice
  * no more that a certain number of characters wide.
  * @param {number} opt_limit The with limit of the source text with a default
  *     of 78
  * @param {number} opt_before The number of characters to prefer before the
  *     position with a default value of 10 less that the limit
  */
-SourceLocation.prototype.restrict = function (opt_limit, opt_before) {
+function SourceLocationRestrict(opt_limit, opt_before) {
   // Find the actual limit to use.
   var limit;
   var before;
   if (!IS_UNDEFINED(opt_limit)) {
     limit = opt_limit;
   } else {
     limit = kLineLengthLimit;
   }
   if (!IS_UNDEFINED(opt_before)) {
     before = opt_before;
@@ skipping 26 matching lines @@
     }
   }
 };
 
 
 /**
  * Get the source text for a SourceLocation
  * @return {String}
  *     Source text for this location.
  */
-SourceLocation.prototype.sourceText = function () {
+function SourceLocationSourceText() {
   return %_CallFunction(this.script.source, this.start, this.end, StringSubstring);
 };
 
 
+SetupLockedPrototype(SourceLocation,
+  $Array("script", "position", "line", "column", "start", "end"),
+  $Array(
+    "restrict", SourceLocationRestrict,
+    "sourceText", SourceLocationSourceText
+  )
+);
+
+
 /**
  * Class for a source slice. A source slice is a part of a script source with
  * the following properties:
  *   script        : script object for the source
  *   from_line     : line number for the first line in the slice
  *   to_line       : source line number for the last line in the slice
  *   from_position : position of the first character in the slice
  *   to_position   : position of the last character in the slice
  * The to_line and to_position are not included in the slice, that is the lines
  * in the slice are [from_line, to_line[. Likewise the characters in the slice
  * are [from_position, to_position[.
  * @param {Script} script The Script object for the source slice
  * @param {number} from_line
  * @param {number} to_line
  * @param {number} from_position
  * @param {number} to_position
  * @constructor
  */
 function SourceSlice(script, from_line, to_line, from_position, to_position) {
   this.script = script;
   this.from_line = from_line;
   this.to_line = to_line;
   this.from_position = from_position;
   this.to_position = to_position;
 }
 
-SourceSlice.prototype.__proto__ = null;
-
 /**
  * Get the source text for a SourceSlice
  * @return {String} Source text for this slice. The last line will include
  *     the line terminating characters (if any)
  */
-SourceSlice.prototype.sourceText = function () {
+function SourceSliceSourceText() {
   return %_CallFunction(this.script.source,
                         this.from_position,
                         this.to_position,
                         StringSubstring);
 };
 
+SetupLockedPrototype(SourceSlice,
+  $Array("script", "from_line", "to_line", "from_position", "to_position"),
+  $Array("sourceText", SourceSliceSourceText)
+);
+
 
 // Returns the offset of the given position within the containing
 // line.
 function GetPositionInLine(message) {
   var script = %MessageGetScript(message);
   var start_position = %MessageGetStartPosition(message);
   var location = script.locationFromPosition(start_position, false);
   if (location == null) return -1;
   location.restrict();
   return start_position - location.start;
@@ skipping 34 matching lines @@
   desc = ToPropertyDescriptor(desc);
   DefineOwnProperty(obj, name, desc, true);
 }
 
 function CallSite(receiver, fun, pos) {
   this.receiver = receiver;
   this.fun = fun;
   this.pos = pos;
 }
 
-CallSite.prototype.__proto__ = null;
-
-CallSite.prototype.getThis = function () {
+function CallSiteGetThis() {
   return this.receiver;
 };
 
-CallSite.prototype.getTypeName = function () {
+function CallSiteGetTypeName() {
   var constructor = this.receiver.constructor;
   if (!constructor) {
     return %_CallFunction(this.receiver, ObjectToString);
   }
   var constructorName = constructor.name;
   if (!constructorName) {
     return %_CallFunction(this.receiver, ObjectToString);
   }
   return constructorName;
 };
 
-CallSite.prototype.isToplevel = function () {
+function CallSiteIsToplevel() {
   if (this.receiver == null) {
     return true;
   }
   return IS_GLOBAL(this.receiver);
 };
 
-CallSite.prototype.isEval = function () {
+function CallSiteIsEval() {
   var script = %FunctionGetScript(this.fun);
   return script && script.compilation_type == COMPILATION_TYPE_EVAL;
 };
 
-CallSite.prototype.getEvalOrigin = function () {
+function CallSiteGetEvalOrigin() {
   var script = %FunctionGetScript(this.fun);
   return FormatEvalOrigin(script);
 };
 
-CallSite.prototype.getScriptNameOrSourceURL = function () {
+function CallSiteGetScriptNameOrSourceURL() {
   var script = %FunctionGetScript(this.fun);
   return script ? script.nameOrSourceURL() : null;
 };
 
-CallSite.prototype.getFunction = function () {
+function CallSiteGetFunction() {
   return this.fun;
 };
 
-CallSite.prototype.getFunctionName = function () {
+function CallSiteGetFunctionName() {
   // See if the function knows its own name
   var name = this.fun.name;
   if (name) {
     return name;
   } else {
     return %FunctionGetInferredName(this.fun);
   }
   // Maybe this is an evaluation?
   var script = %FunctionGetScript(this.fun);
   if (script && script.compilation_type == COMPILATION_TYPE_EVAL) {
     return "eval";
   }
   return null;
 };
 
-CallSite.prototype.getMethodName = function () {
+function CallSiteGetMethodName() {
   // See if we can find a unique property on the receiver that holds
   // this function.
   var ownName = this.fun.name;
   if (ownName && this.receiver &&
       (%_CallFunction(this.receiver, ownName, ObjectLookupGetter) === this.fun ||
        %_CallFunction(this.receiver, ownName, ObjectLookupSetter) === this.fun ||
        this.receiver[ownName] === this.fun)) {
     // To handle DontEnum properties we guess that the method has
     // the same name as the function.
     return ownName;
   }
   var name = null;
   for (var prop in this.receiver) {
     if (this.receiver.__lookupGetter__(prop) === this.fun ||
         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) {
         return null;
       }
       name = prop;
     }
   }
   if (name) {
     return name;
   }
   return null;
 };
 
-CallSite.prototype.getFileName = function () {
+function CallSiteGetFileName() {
   var script = %FunctionGetScript(this.fun);
   return script ? script.name : null;
 };
 
-CallSite.prototype.getLineNumber = function () {
+function CallSiteGetLineNumber() {
   if (this.pos == -1) {
     return null;
   }
   var script = %FunctionGetScript(this.fun);
   var location = null;
   if (script) {
     location = script.locationFromPosition(this.pos, true);
   }
   return location ? location.line + 1 : null;
 };
 
-CallSite.prototype.getColumnNumber = function () {
+function CallSiteGetColumnNumber() {
   if (this.pos == -1) {
     return null;
   }
   var script = %FunctionGetScript(this.fun);
   var location = null;
   if (script) {
     location = script.locationFromPosition(this.pos, true);
   }
   return location ? location.column + 1: null;
 };
 
-CallSite.prototype.isNative = function () {
+function CallSiteIsNative() {
   var script = %FunctionGetScript(this.fun);
   return script ? (script.type == TYPE_NATIVE) : false;
 };
 
-CallSite.prototype.getPosition = function () {
+function CallSiteGetPosition() {
   return this.pos;
 };
 
-CallSite.prototype.isConstructor = function () {
+function CallSiteIsConstructor() {
   var constructor = this.receiver ? this.receiver.constructor : null;
   if (!constructor) {
     return false;
   }
   return this.fun === constructor;
 };
 
+SetupLockedPrototype(CallSite, $Array("receiver", "fun", "pos"), $Array(
+  "getThis", CallSiteGetThis,
+  "getTypeName", CallSiteGetTypeName,
+  "isToplevel", CallSiteIsToplevel,
+  "isEval", CallSiteIsEval,
+  "getEvalOrigin", CallSiteGetEvalOrigin,
+  "getScriptNameOrSourceURL", CallSiteGetScriptNameOrSourceURL,
+  "getFunction", CallSiteGetFunction,
+  "getFunctionName", CallSiteGetFunctionName,
+  "getMethodName", CallSiteGetMethodName,
+  "getFileName", CallSiteGetFileName,
+  "getLineNumber", CallSiteGetLineNumber,
+  "getColumnNumber", CallSiteGetColumnNumber,
+  "isNative", CallSiteIsNative,
+  "getPosition", CallSiteGetPosition,
+  "isConstructor", CallSiteIsConstructor
+));
+
+
 function FormatEvalOrigin(script) {
   var sourceURL = script.nameOrSourceURL();
   if (sourceURL) {
     return sourceURL;
   }
 
   var eval_origin = "eval at ";
   if (script.eval_from_function_name) {
     eval_origin += script.eval_from_function_name;
   } else {
@@ skipping 122 matching lines @@
     frames.push(new CallSite(recv, fun, pos));
   }
   if (IS_FUNCTION($Error.prepareStackTrace)) {
     return $Error.prepareStackTrace(error, frames);
   } else {
     return FormatStackTrace(error, frames);
   }
 }
 
 function DefineError(f) {
+  %AssertIsBootstrapping();
   // Store the error function in both the global object
   // and the runtime object. The function is fetched
   // from the runtime object when throwing errors from
   // within the runtime system to avoid strange side
   // effects when overwriting the error functions from
   // user code.
   var name = f.name;
   %SetProperty(global, name, f, DONT_ENUM);
   this['$' + name] = f;
   // Configure the error function.
@@ skipping 67 matching lines @@
 this.DefineError(function RangeError() { });
 this.DefineError(function SyntaxError() { });
 this.DefineError(function ReferenceError() { });
 this.DefineError(function EvalError() { });
 this.DefineError(function URIError() { });
 
 $Error.captureStackTrace = captureStackTrace;
 
 // Setup extra properties of the Error.prototype object.
 function setErrorMessage() {
+  %AssertIsBootstrapping();
   var desc = {value: '',
               enumerable: false,
               configurable: true,
               writable: true };
   DefineOwnProperty($Error.prototype,
                     'message',
                     ToPropertyDescriptor(desc),
                     true);
 
 }
@@ skipping 42 matching lines @@
     throw e;
   }
 }
 
 
 InstallFunctions($Error.prototype, DONT_ENUM, ['toString', errorToString]);
 
 // Boilerplate for exceptions for stack overflows. Used from
 // Isolate::StackOverflow().
 const kStackOverflowBoilerplate = MakeRangeError('stack_overflow', []);