Initial import.

1 files changed, 1350 insertions, 0 deletions

diff --git a/chromium/v8/src/messages.js b/chromium/v8/src/messages.js
new file mode 100644
index 00000000000..2debbf86540
--- /dev/null
+++ b/chromium/v8/src/messages.js
@@ -0,0 +1,1350 @@
+// Copyright 2012 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
+//       with the distribution.
+//     * Neither the name of Google Inc. nor the names of its
+//       contributors may be used to endorse or promote products derived
+//       from this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+// -------------------------------------------------------------------
+
+var kMessages = {
+  // Error
+  cyclic_proto:                  ["Cyclic __proto__ value"],
+  code_gen_from_strings:         ["%0"],
+  generator_running:             ["Generator is already running"],
+  generator_finished:            ["Generator has already finished"],
+  // TypeError
+  unexpected_token:              ["Unexpected token ", "%0"],
+  unexpected_token_number:       ["Unexpected number"],
+  unexpected_token_string:       ["Unexpected string"],
+  unexpected_token_identifier:   ["Unexpected identifier"],
+  unexpected_reserved:           ["Unexpected reserved word"],
+  unexpected_strict_reserved:    ["Unexpected strict mode reserved word"],
+  unexpected_eos:                ["Unexpected end of input"],
+  malformed_regexp:              ["Invalid regular expression: /", "%0", "/: ", "%1"],
+  unterminated_regexp:           ["Invalid regular expression: missing /"],
+  regexp_flags:                  ["Cannot supply flags when constructing one RegExp from another"],
+  incompatible_method_receiver:  ["Method ", "%0", " called on incompatible receiver ", "%1"],
+  invalid_lhs_in_assignment:     ["Invalid left-hand side in assignment"],
+  invalid_lhs_in_for_in:         ["Invalid left-hand side in for-in"],
+  invalid_lhs_in_postfix_op:     ["Invalid left-hand side expression in postfix operation"],
+  invalid_lhs_in_prefix_op:      ["Invalid left-hand side expression in prefix operation"],
+  multiple_defaults_in_switch:   ["More than one default clause in switch statement"],
+  newline_after_throw:           ["Illegal newline after throw"],
+  redeclaration:                 ["%0", " '", "%1", "' has already been declared"],
+  no_catch_or_finally:           ["Missing catch or finally after try"],
+  unknown_label:                 ["Undefined label '", "%0", "'"],
+  uncaught_exception:            ["Uncaught ", "%0"],
+  stack_trace:                   ["Stack Trace:\n", "%0"],
+  called_non_callable:           ["%0", " is not a function"],
+  undefined_method:              ["Object ", "%1", " has no method '", "%0", "'"],
+  property_not_function:         ["Property '", "%0", "' of object ", "%1", " is not a function"],
+  cannot_convert_to_primitive:   ["Cannot convert object to primitive value"],
+  not_constructor:               ["%0", " is not a constructor"],
+  not_defined:                   ["%0", " is not defined"],
+  non_object_property_load:      ["Cannot read property '", "%0", "' of ", "%1"],
+  non_object_property_store:     ["Cannot set property '", "%0", "' of ", "%1"],
+  non_object_property_call:      ["Cannot call method '", "%0", "' of ", "%1"],
+  with_expression:               ["%0", " has no properties"],
+  illegal_invocation:            ["Illegal invocation"],
+  no_setter_in_callback:         ["Cannot set property ", "%0", " of ", "%1", " which has only a getter"],
+  apply_non_function:            ["Function.prototype.apply was called on ", "%0", ", which is a ", "%1", " and not a function"],
+  apply_wrong_args:              ["Function.prototype.apply: Arguments list has wrong type"],
+  invalid_in_operator_use:       ["Cannot use 'in' operator to search for '", "%0", "' in ", "%1"],
+  instanceof_function_expected:  ["Expecting a function in instanceof check, but got ", "%0"],
+  instanceof_nonobject_proto:    ["Function has non-object prototype '", "%0", "' in instanceof check"],
+  undefined_or_null_to_object:   ["Cannot convert undefined or null to object"],
+  reduce_no_initial:             ["Reduce of empty array with no initial value"],
+  getter_must_be_callable:       ["Getter must be a function: ", "%0"],
+  setter_must_be_callable:       ["Setter must be a function: ", "%0"],
+  value_and_accessor:            ["Invalid property.  A property cannot both have accessors and be writable or have a value, ", "%0"],
+  proto_object_or_null:          ["Object prototype may only be an Object or null"],
+  property_desc_object:          ["Property description must be an object: ", "%0"],
+  redefine_disallowed:           ["Cannot redefine property: ", "%0"],
+  define_disallowed:             ["Cannot define property:", "%0", ", object is not extensible."],
+  non_extensible_proto:          ["%0", " is not extensible"],
+  handler_non_object:            ["Proxy.", "%0", " called with non-object as handler"],
+  proto_non_object:              ["Proxy.", "%0", " called with non-object as prototype"],
+  trap_function_expected:        ["Proxy.", "%0", " called with non-function for '", "%1", "' trap"],
+  handler_trap_missing:          ["Proxy handler ", "%0", " has no '", "%1", "' trap"],
+  handler_trap_must_be_callable: ["Proxy handler ", "%0", " has non-callable '", "%1", "' trap"],
+  handler_returned_false:        ["Proxy handler ", "%0", " returned false from '", "%1", "' trap"],
+  handler_returned_undefined:    ["Proxy handler ", "%0", " returned undefined from '", "%1", "' trap"],
+  proxy_prop_not_configurable:   ["Proxy handler ", "%0", " returned non-configurable descriptor for property '", "%2", "' from '", "%1", "' trap"],
+  proxy_non_object_prop_names:   ["Trap '", "%1", "' returned non-object ", "%0"],
+  proxy_repeated_prop_name:      ["Trap '", "%1", "' returned repeated property name '", "%2", "'"],
+  invalid_weakmap_key:           ["Invalid value used as weak map key"],
+  invalid_weakset_value:         ["Invalid value used in weak set"],
+  not_date_object:               ["this is not a Date object."],
+  observe_non_object:            ["Object.", "%0", " cannot ", "%0", " non-object"],
+  observe_non_function:          ["Object.", "%0", " cannot deliver to non-function"],
+  observe_callback_frozen:       ["Object.observe cannot deliver to a frozen function object"],
+  observe_invalid_accept:        ["Object.observe accept must be an array of strings."],
+  observe_type_non_string:       ["Invalid changeRecord with non-string 'type' property"],
+  observe_perform_non_string:    ["Invalid non-string changeType"],
+  observe_perform_non_function:  ["Cannot perform non-function"],
+  observe_notify_non_notifier:   ["notify called on non-notifier object"],
+  proto_poison_pill:             ["Generic use of __proto__ accessor not allowed"],
+  not_typed_array:               ["this is not a typed array."],
+  invalid_argument:              ["invalid_argument"],
+  data_view_not_array_buffer:    ["First argument to DataView constructor must be an ArrayBuffer"],
+  constructor_not_function:      ["Constructor ", "%0", " requires 'new'"],
+  // RangeError
+  invalid_array_length:          ["Invalid array length"],
+  invalid_array_buffer_length:   ["Invalid array buffer length"],
+  invalid_typed_array_offset:    ["Start offset is too large:"],
+  invalid_typed_array_length:    ["Invalid typed array length"],
+  invalid_typed_array_alignment: ["%0", "of", "%1", "should be a multiple of", "%3"],
+  typed_array_set_source_too_large:
+                                 ["Source is too large"],
+  typed_array_set_negative_offset:
+                                 ["Start offset is negative"],
+  invalid_data_view_offset:      ["Start offset is outside the bounds of the buffer"],
+  invalid_data_view_length:      ["Invalid data view length"],
+  invalid_data_view_accessor_offset:
+                                 ["Offset is outside the bounds of the DataView"],
+
+  stack_overflow:                ["Maximum call stack size exceeded"],
+  invalid_time_value:            ["Invalid time value"],
+  invalid_count_value:           ["Invalid count value"],
+  // SyntaxError
+  paren_in_arg_string:           ["Function arg string contains parenthesis"],
+  not_isvar:                     ["builtin %IS_VAR: not a variable"],
+  single_function_literal:       ["Single function literal required"],
+  invalid_regexp_flags:          ["Invalid flags supplied to RegExp constructor '", "%0", "'"],
+  invalid_regexp:                ["Invalid RegExp pattern /", "%0", "/"],
+  illegal_break:                 ["Illegal break statement"],
+  illegal_continue:              ["Illegal continue statement"],
+  illegal_return:                ["Illegal return statement"],
+  illegal_let:                   ["Illegal let declaration outside extended mode"],
+  error_loading_debugger:        ["Error loading debugger"],
+  no_input_to_regexp:            ["No input to ", "%0"],
+  invalid_json:                  ["String '", "%0", "' is not valid JSON"],
+  circular_structure:            ["Converting circular structure to JSON"],
+  called_on_non_object:          ["%0", " called on non-object"],
+  called_on_null_or_undefined:   ["%0", " called on null or undefined"],
+  array_indexof_not_defined:     ["Array.getIndexOf: Argument undefined"],
+  object_not_extensible:         ["Can't add property ", "%0", ", object is not extensible"],
+  illegal_access:                ["Illegal access"],
+  invalid_preparser_data:        ["Invalid preparser data for function ", "%0"],
+  strict_mode_with:              ["Strict mode code may not include a with statement"],
+  strict_catch_variable:         ["Catch variable may not be eval or arguments in strict mode"],
+  too_many_arguments:            ["Too many arguments in function call (only 32766 allowed)"],
+  too_many_parameters:           ["Too many parameters in function definition (only 32766 allowed)"],
+  too_many_variables:            ["Too many variables declared (only 131071 allowed)"],
+  strict_param_name:             ["Parameter name eval or arguments is not allowed in strict mode"],
+  strict_param_dupe:             ["Strict mode function may not have duplicate parameter names"],
+  strict_var_name:               ["Variable name may not be eval or arguments in strict mode"],
+  strict_function_name:          ["Function name may not be eval or arguments in strict mode"],
+  strict_octal_literal:          ["Octal literals are not allowed in strict mode."],
+  strict_duplicate_property:     ["Duplicate data property in object literal not allowed in strict mode"],
+  accessor_data_property:        ["Object literal may not have data and accessor property with the same name"],
+  accessor_get_set:              ["Object literal may not have multiple get/set accessors with the same name"],
+  strict_lhs_assignment:         ["Assignment to eval or arguments is not allowed in strict mode"],
+  strict_lhs_postfix:            ["Postfix increment/decrement may not have eval or arguments operand in strict mode"],
+  strict_lhs_prefix:             ["Prefix increment/decrement may not have eval or arguments operand in strict mode"],
+  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."],
+  unprotected_const:             ["Illegal const declaration in unprotected statement context."],
+  cant_prevent_ext_external_array_elements: ["Cannot prevent extension of an object with external array elements"],
+  redef_external_array_element:  ["Cannot redefine a property of an object with external array elements"],
+  harmony_const_assign:          ["Assignment to constant variable."],
+  symbol_to_string:              ["Conversion from symbol to string"],
+  invalid_module_path:           ["Module does not export '", "%0", "', or export is not itself a module"],
+  module_type_error:             ["Module '", "%0", "' used improperly"],
+  module_export_undefined:       ["Export '", "%0", "' is not defined in module"]
+};
+
+
+function FormatString(format, args) {
+  var result = "";
+  var arg_num = 0;
+  for (var i = 0; i < format.length; i++) {
+    var str = format[i];
+    if (str.length == 2 && %_StringCharCodeAt(str, 0) == 0x25) {
+      // Two-char string starts with "%".
+      var arg_num = (%_StringCharCodeAt(str, 1) - 0x30) >>> 0;
+      if (arg_num < 4) {
+        // str is one of %0, %1, %2 or %3.
+        try {
+          str = NoSideEffectToString(args[arg_num]);
+        } catch (e) {
+          if (%IsJSModule(args[arg_num]))
+            str = "module";
+          else if (IS_SPEC_OBJECT(args[arg_num]))
+            str = "object";
+          else
+            str = "#<error>";
+        }
+      }
+    }
+    result += str;
+  }
+  return result;
+}
+
+
+function NoSideEffectToString(obj) {
+  if (IS_STRING(obj)) return obj;
+  if (IS_NUMBER(obj)) return %_NumberToString(obj);
+  if (IS_BOOLEAN(obj)) return x ? 'true' : 'false';
+  if (IS_UNDEFINED(obj)) return 'undefined';
+  if (IS_NULL(obj)) return 'null';
+  if (IS_FUNCTION(obj)) return  %_CallFunction(obj, FunctionToString);
+  if (IS_OBJECT(obj) && %GetDataProperty(obj, "toString") === ObjectToString) {
+    var constructor = %GetDataProperty(obj, "constructor");
+    if (typeof constructor == "function") {
+      var constructorName = constructor.name;
+      if (IS_STRING(constructorName) && constructorName !== "") {
+        return "#<" + constructorName + ">";
+      }
+    }
+  }
+  if (CanBeSafelyTreatedAsAnErrorObject(obj)) {
+    return %_CallFunction(obj, ErrorToString);
+  }
+  return %_CallFunction(obj, ObjectToString);
+}
+
+// To determine whether we can safely stringify an object using ErrorToString
+// without the risk of side-effects, we need to check whether the object is
+// either an instance of a native error type (via '%_ClassOf'), or has $Error
+// in its prototype chain and hasn't overwritten 'toString' with something
+// strange and unusual.
+function CanBeSafelyTreatedAsAnErrorObject(obj) {
+  switch (%_ClassOf(obj)) {
+    case 'Error':
+    case 'EvalError':
+    case 'RangeError':
+    case 'ReferenceError':
+    case 'SyntaxError':
+    case 'TypeError':
+    case 'URIError':
+      return true;
+  }
+
+  var objToString = %GetDataProperty(obj, "toString");
+  return obj instanceof $Error && objToString === ErrorToString;
+}
+
+
+// When formatting internally created error messages, do not
+// invoke overwritten error toString methods but explicitly use
+// the error to string method. This is to avoid leaking error
+// objects between script tags in a browser setting.
+function ToStringCheckErrorObject(obj) {
+  if (CanBeSafelyTreatedAsAnErrorObject(obj)) {
+    return %_CallFunction(obj, ErrorToString);
+  } else {
+    return ToString(obj);
+  }
+}
+
+
+function ToDetailString(obj) {
+  if (obj != null && IS_OBJECT(obj) && obj.toString === ObjectToString) {
+    var constructor = obj.constructor;
+    if (typeof constructor == "function") {
+      var constructorName = constructor.name;
+      if (IS_STRING(constructorName) && constructorName !== "") {
+        return "#<" + constructorName + ">";
+      }
+    }
+  }
+  return ToStringCheckErrorObject(obj);
+}
+
+
+function MakeGenericError(constructor, type, args) {
+  if (IS_UNDEFINED(args)) args = [];
+  return new constructor(FormatMessage(type, args));
+}
+
+
+/**
+ * Set up the Script function and constructor.
+ */
+%FunctionSetInstanceClassName(Script, 'Script');
+%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 $Error("Not supported");
+});
+
+
+// Helper functions; called from the runtime system.
+function FormatMessage(type, args) {
+  var format = kMessages[type];
+  if (!format) return "<unknown message " + type + ">";
+  return FormatString(format, args);
+}
+
+
+function GetLineNumber(message) {
+  var start_position = %MessageGetStartPosition(message);
+  if (start_position == -1) return kNoLineNumberInfo;
+  var script = %MessageGetScript(message);
+  var location = script.locationFromPosition(start_position, true);
+  if (location == null) return kNoLineNumberInfo;
+  return location.line + 1;
+}
+
+
+// Returns the source code line containing the given source
+// position, or the empty string if the position is invalid.
+function GetSourceLine(message) {
+  var script = %MessageGetScript(message);
+  var start_position = %MessageGetStartPosition(message);
+  var location = script.locationFromPosition(start_position, true);
+  if (location == null) return "";
+  location.restrict();
+  return location.sourceText();
+}
+
+
+function MakeTypeError(type, args) {
+  return MakeGenericError($TypeError, type, args);
+}
+
+
+function MakeRangeError(type, args) {
+  return MakeGenericError($RangeError, type, args);
+}
+
+
+function MakeSyntaxError(type, args) {
+  return MakeGenericError($SyntaxError, type, args);
+}
+
+
+function MakeReferenceError(type, args) {
+  return MakeGenericError($ReferenceError, type, args);
+}
+
+
+function MakeEvalError(type, args) {
+  return MakeGenericError($EvalError, type, args);
+}
+
+
+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.
+ */
+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].
+  if (position <= line_ends[0]) {
+    return 0;
+  }
+
+  // Binary search to find line # from position range.
+  while (upper >= 1) {
+    var i = (lower + upper) >> 1;
+
+    if (position > line_ends[i]) {
+      lower = i + 1;
+    } else if (position <= line_ends[i - 1]) {
+      upper = i - 1;
+    } else {
+      return i;
+    }
+  }
+
+  return -1;
+}
+
+/**
+ * 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.
+ */
+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--;
+  }
+  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
+ * @return {SourceLocation}
+ *     If line is negative or not in the source null is returned.
+ */
+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;
+  if (line == 0) {
+    column -= this.column_offset;
+  }
+
+  var offset_position = opt_offset_position || 0;
+  if (line < 0 || column < 0 || offset_position < 0) return null;
+  if (line == 0) {
+    return this.locationFromPosition(offset_position + column, false);
+  } else {
+    // Find the line where the offset position is located.
+    var offset_line = this.lineFromPosition(offset_position);
+
+    if (offset_line == -1 || offset_line + line >= this.lineCount()) {
+      return null;
+    }
+
+    return this.locationFromPosition(
+        this.line_ends[offset_line + line - 1] + 1 + column);  // line > 0 here.
+  }
+}
+
+
+/**
+ * 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
+ */
+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);
+}
+
+
+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.
+ */
+function ScriptLineCount() {
+  // Return number of source lines.
+  return this.line_ends.length;
+}
+
+
+/**
+ * If sourceURL comment is available and script starts at zero returns sourceURL
+ * comment contents. Otherwise, script name is returned. See
+ * http://fbug.googlecode.com/svn/branches/firebug1.1/docs/ReleaseNotes_1.1.txt
+ * and Source Map Revision 3 proposal for details on using //# sourceURL and
+ * deprecated //@ sourceURL comment to identify scripts that don't have name.
+ *
+ * @return {?string} script name if present, value for //# sourceURL or
+ * deprecated //@ sourceURL comment otherwise.
+ */
+function ScriptNameOrSourceURL() {
+  if (this.line_offset > 0 || this.column_offset > 0) {
+    return this.name;
+  }
+
+  // The result is cached as on long scripts it takes noticable time to search
+  // for the sourceURL.
+  if (this.hasCachedNameOrSourceURL) {
+    return this.cachedNameOrSourceURL;
+  }
+  this.hasCachedNameOrSourceURL = true;
+
+  // 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);
+  this.cachedNameOrSourceURL = this.name;
+  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) {
+      this.cachedNameOrSourceURL =
+          %_SubString(source, matchInfo[CAPTURE(2)], matchInfo[CAPTURE(3)]);
+    }
+  }
+  return this.cachedNameOrSourceURL;
+}
+
+
+SetUpLockedPrototype(Script,
+  $Array("source", "name", "line_ends", "line_offset", "column_offset",
+         "cachedNameOrSourceURL", "hasCachedNameOrSourceURL" ),
+  $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 most cases end will point to a newline character.
+ * It might point just past the final position of the source if the last
+ * source line does not end with a newline character.
+ * @param {Script} script The Script object for which this is a location
+ * @param {number} position Source position for the location
+ * @param {number} line The line number for the location
+ * @param {number} column The column within the line for the location
+ * @param {number} start Source position for start of source context
+ * @param {number} end Source position for end of source context
+ * @constructor
+ */
+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;
+}
+
+var 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
+ */
+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;
+  } else {
+    // If no before is specified center for small limits and perfer more source
+    // before the the position that after for longer limits.
+    if (limit <= 20) {
+      before = $floor(limit / 2);
+    } else {
+      before = limit - 10;
+    }
+  }
+  if (before >= limit) {
+    before = limit - 1;
+  }
+
+  // If the [start, end[ interval is too big we restrict
+  // it in one or both ends. We make sure to always produce
+  // restricted intervals of maximum allowed size.
+  if (this.end - this.start > limit) {
+    var start_limit = this.position - before;
+    var end_limit = this.position + limit - before;
+    if (this.start < start_limit && end_limit < this.end) {
+      this.start = start_limit;
+      this.end = end_limit;
+    } else if (this.start < start_limit) {
+      this.start = this.end - limit;
+    } else {
+      this.end = this.start + limit;
+    }
+  }
+}
+
+
+/**
+ * Get the source text for a SourceLocation
+ * @return {String}
+ *     Source text for this location.
+ */
+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;
+}
+
+/**
+ * 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)
+ */
+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;
+}
+
+
+function GetStackTraceLine(recv, fun, pos, isGlobal) {
+  return new CallSite(recv, fun, pos, false).toString();
+}
+
+// ----------------------------------------------------------------------------
+// Error implementation
+
+var CallSiteReceiverKey = %CreateSymbol("receiver");
+var CallSiteFunctionKey = %CreateSymbol("function");
+var CallSitePositionKey = %CreateSymbol("position");
+var CallSiteStrictModeKey = %CreateSymbol("strict mode");
+
+function CallSite(receiver, fun, pos, strict_mode) {
+  this[CallSiteReceiverKey] = receiver;
+  this[CallSiteFunctionKey] = fun;
+  this[CallSitePositionKey] = pos;
+  this[CallSiteStrictModeKey] = strict_mode;
+}
+
+function CallSiteGetThis() {
+  return this[CallSiteStrictModeKey] ? void 0 : this[CallSiteReceiverKey];
+}
+
+function CallSiteGetTypeName() {
+  return GetTypeName(this[CallSiteReceiverKey], false);
+}
+
+function CallSiteIsToplevel() {
+  if (this[CallSiteReceiverKey] == null) {
+    return true;
+  }
+  return IS_GLOBAL(this[CallSiteReceiverKey]);
+}
+
+function CallSiteIsEval() {
+  var script = %FunctionGetScript(this[CallSiteFunctionKey]);
+  return script && script.compilation_type == COMPILATION_TYPE_EVAL;
+}
+
+function CallSiteGetEvalOrigin() {
+  var script = %FunctionGetScript(this[CallSiteFunctionKey]);
+  return FormatEvalOrigin(script);
+}
+
+function CallSiteGetScriptNameOrSourceURL() {
+  var script = %FunctionGetScript(this[CallSiteFunctionKey]);
+  return script ? script.nameOrSourceURL() : null;
+}
+
+function CallSiteGetFunction() {
+  return this[CallSiteStrictModeKey] ? void 0 : this[CallSiteFunctionKey];
+}
+
+function CallSiteGetFunctionName() {
+  // See if the function knows its own name
+  var name = this[CallSiteFunctionKey].name;
+  if (name) {
+    return name;
+  }
+  name = %FunctionGetInferredName(this[CallSiteFunctionKey]);
+  if (name) {
+    return name;
+  }
+  // Maybe this is an evaluation?
+  var script = %FunctionGetScript(this[CallSiteFunctionKey]);
+  if (script && script.compilation_type == COMPILATION_TYPE_EVAL) {
+    return "eval";
+  }
+  return null;
+}
+
+function CallSiteGetMethodName() {
+  // See if we can find a unique property on the receiver that holds
+  // this function.
+  var receiver = this[CallSiteReceiverKey];
+  var fun = this[CallSiteFunctionKey];
+  var ownName = fun.name;
+  if (ownName && receiver &&
+      (%_CallFunction(receiver, ownName, ObjectLookupGetter) === fun ||
+       %_CallFunction(receiver, ownName, ObjectLookupSetter) === fun ||
+       (IS_OBJECT(receiver) && %GetDataProperty(receiver, ownName) === 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 receiver) {
+    if (%_CallFunction(receiver, prop, ObjectLookupGetter) === fun ||
+        %_CallFunction(receiver, prop, ObjectLookupSetter) === fun ||
+        (IS_OBJECT(receiver) && %GetDataProperty(receiver, prop) === 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;
+}
+
+function CallSiteGetFileName() {
+  var script = %FunctionGetScript(this[CallSiteFunctionKey]);
+  return script ? script.name : null;
+}
+
+function CallSiteGetLineNumber() {
+  if (this[CallSitePositionKey] == -1) {
+    return null;
+  }
+  var script = %FunctionGetScript(this[CallSiteFunctionKey]);
+  var location = null;
+  if (script) {
+    location = script.locationFromPosition(this[CallSitePositionKey], true);
+  }
+  return location ? location.line + 1 : null;
+}
+
+function CallSiteGetColumnNumber() {
+  if (this[CallSitePositionKey] == -1) {
+    return null;
+  }
+  var script = %FunctionGetScript(this[CallSiteFunctionKey]);
+  var location = null;
+  if (script) {
+    location = script.locationFromPosition(this[CallSitePositionKey], true);
+  }
+  return location ? location.column + 1: null;
+}
+
+function CallSiteIsNative() {
+  var script = %FunctionGetScript(this[CallSiteFunctionKey]);
+  return script ? (script.type == TYPE_NATIVE) : false;
+}
+
+function CallSiteGetPosition() {
+  return this[CallSitePositionKey];
+}
+
+function CallSiteIsConstructor() {
+  var receiver = this[CallSiteReceiverKey];
+  var constructor = (receiver != null && IS_OBJECT(receiver))
+                        ? %GetDataProperty(receiver, "constructor") : null;
+  if (!constructor) return false;
+  return this[CallSiteFunctionKey] === constructor;
+}
+
+function CallSiteToString() {
+  var fileName;
+  var fileLocation = "";
+  if (this.isNative()) {
+    fileLocation = "native";
+  } else {
+    if (this.isEval()) {
+      fileName = this.getScriptNameOrSourceURL();
+      if (!fileName) {
+        fileLocation = this.getEvalOrigin();
+        fileLocation += ", ";  // Expecting source position to follow.
+      }
+    } else {
+      fileName = this.getFileName();
+    }
+
+    if (fileName) {
+      fileLocation += fileName;
+    } else {
+      // Source code does not originate from a file and is not native, but we
+      // can still get the source position inside the source string, e.g. in
+      // an eval string.
+      fileLocation += "<anonymous>";
+    }
+    var lineNumber = this.getLineNumber();
+    if (lineNumber != null) {
+      fileLocation += ":" + lineNumber;
+      var columnNumber = this.getColumnNumber();
+      if (columnNumber) {
+        fileLocation += ":" + columnNumber;
+      }
+    }
+  }
+
+  var line = "";
+  var functionName = this.getFunctionName();
+  var addSuffix = true;
+  var isConstructor = this.isConstructor();
+  var isMethodCall = !(this.isToplevel() || isConstructor);
+  if (isMethodCall) {
+    var typeName = GetTypeName(this[CallSiteReceiverKey], true);
+    var methodName = this.getMethodName();
+    if (functionName) {
+      if (typeName &&
+          %_CallFunction(functionName, typeName, StringIndexOf) != 0) {
+        line += typeName + ".";
+      }
+      line += functionName;
+      if (methodName &&
+          (%_CallFunction(functionName, "." + methodName, StringIndexOf) !=
+           functionName.length - methodName.length - 1)) {
+        line += " [as " + methodName + "]";
+      }
+    } else {
+      line += typeName + "." + (methodName || "<anonymous>");
+    }
+  } else if (isConstructor) {
+    line += "new " + (functionName || "<anonymous>");
+  } else if (functionName) {
+    line += functionName;
+  } else {
+    line += fileLocation;
+    addSuffix = false;
+  }
+  if (addSuffix) {
+    line += " (" + fileLocation + ")";
+  }
+  return line;
+}
+
+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,
+  "toString", CallSiteToString
+));
+
+
+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 {
+    eval_origin +=  "<anonymous>";
+  }
+
+  var eval_from_script = script.eval_from_script;
+  if (eval_from_script) {
+    if (eval_from_script.compilation_type == COMPILATION_TYPE_EVAL) {
+      // eval script originated from another eval.
+      eval_origin += " (" + FormatEvalOrigin(eval_from_script) + ")";
+    } else {
+      // eval script originated from "real" source.
+      if (eval_from_script.name) {
+        eval_origin += " (" + eval_from_script.name;
+        var location = eval_from_script.locationFromPosition(
+            script.eval_from_script_position, true);
+        if (location) {
+          eval_origin += ":" + (location.line + 1);
+          eval_origin += ":" + (location.column + 1);
+        }
+        eval_origin += ")";
+      } else {
+        eval_origin += " (unknown source)";
+      }
+    }
+  }
+
+  return eval_origin;
+}
+
+
+function FormatErrorString(error) {
+  try {
+    return %_CallFunction(error, ErrorToString);
+  } catch (e) {
+    try {
+      return "<error: " + e + ">";
+    } catch (ee) {
+      return "<error>";
+    }
+  }
+}
+
+
+function GetStackFrames(raw_stack) {
+  var frames = new InternalArray();
+  var non_strict_frames = raw_stack[0];
+  for (var i = 1; i < raw_stack.length; i += 4) {
+    var recv = raw_stack[i];
+    var fun = raw_stack[i + 1];
+    var code = raw_stack[i + 2];
+    var pc = raw_stack[i + 3];
+    var pos = %FunctionGetPositionForOffset(code, pc);
+    non_strict_frames--;
+    frames.push(new CallSite(recv, fun, pos, (non_strict_frames < 0)));
+  }
+  return frames;
+}
+
+
+// Flag to prevent recursive call of Error.prepareStackTrace.
+var formatting_custom_stack_trace = false;
+
+
+function FormatStackTrace(obj, error_string, frames) {
+  if (IS_FUNCTION($Error.prepareStackTrace) && !formatting_custom_stack_trace) {
+    var array = [];
+    %MoveArrayContents(frames, array);
+    formatting_custom_stack_trace = true;
+    var stack_trace = void 0;
+    try {
+      stack_trace = $Error.prepareStackTrace(obj, array);
+    } catch (e) {
+      throw e;  // The custom formatting function threw.  Rethrow.
+    } finally {
+      formatting_custom_stack_trace = false;
+    }
+    return stack_trace;
+  }
+
+  var lines = new InternalArray();
+  lines.push(error_string);
+  for (var i = 0; i < frames.length; i++) {
+    var frame = frames[i];
+    var line;
+    try {
+      line = frame.toString();
+    } catch (e) {
+      try {
+        line = "<error: " + e + ">";
+      } catch (ee) {
+        // Any code that reaches this point is seriously nasty!
+        line = "<error>";
+      }
+    }
+    lines.push("    at " + line);
+  }
+  return %_CallFunction(lines, "\n", ArrayJoin);
+}
+
+
+function GetTypeName(receiver, requireConstructor) {
+  var constructor = receiver.constructor;
+  if (!constructor) {
+    return requireConstructor ? null :
+        %_CallFunction(receiver, ObjectToString);
+  }
+  var constructorName = constructor.name;
+  if (!constructorName) {
+    return requireConstructor ? null :
+        %_CallFunction(receiver, ObjectToString);
+  }
+  return constructorName;
+}
+
+
+function captureStackTrace(obj, cons_opt) {
+  var stackTraceLimit = $Error.stackTraceLimit;
+  if (!stackTraceLimit || !IS_NUMBER(stackTraceLimit)) return;
+  if (stackTraceLimit < 0 || stackTraceLimit > 10000) {
+    stackTraceLimit = 10000;
+  }
+  var stack = %CollectStackTrace(obj,
+                                 cons_opt ? cons_opt : captureStackTrace,
+                                 stackTraceLimit);
+
+  var error_string = FormatErrorString(obj);
+  // The holder of this getter ('obj') may not be the receiver ('this').
+  // When this getter is called the first time, we use the context values to
+  // format a stack trace string and turn this accessor pair into a data
+  // property (on the holder).
+  var getter = function() {
+    // Stack is still a raw array awaiting to be formatted.
+    var result = FormatStackTrace(obj, error_string, GetStackFrames(stack));
+    // Turn this accessor into a data property.
+    %DefineOrRedefineDataProperty(obj, 'stack', result, NONE);
+    // Release context values.
+    stack = error_string = void 0;
+    return result;
+  };
+
+  // Set the 'stack' property on the receiver.  If the receiver is the same as
+  // holder of this setter, the accessor pair is turned into a data property.
+  var setter = function(v) {
+    // Set data property on the receiver (not necessarily holder).
+    %DefineOrRedefineDataProperty(this, 'stack', v, NONE);
+    if (this === obj) {
+      // Release context values if holder is the same as the receiver.
+      stack = error_string = void 0;
+    }
+  };
+
+  %DefineOrRedefineAccessorProperty(obj, 'stack', getter, setter, DONT_ENUM);
+}
+
+
+function SetUpError() {
+  // Define special error type constructors.
+
+  var DefineError = function(f) {
+    // 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);
+    %SetProperty(builtins, '$' + name, f, DONT_ENUM | DONT_DELETE | READ_ONLY);
+    // Configure the error function.
+    if (name == 'Error') {
+      // The prototype of the Error object must itself be an error.
+      // However, it can't be an instance of the Error object because
+      // it hasn't been properly configured yet.  Instead we create a
+      // special not-a-true-error-but-close-enough object.
+      var ErrorPrototype = function() {};
+      %FunctionSetPrototype(ErrorPrototype, $Object.prototype);
+      %FunctionSetInstanceClassName(ErrorPrototype, 'Error');
+      %FunctionSetPrototype(f, new ErrorPrototype());
+    } else {
+      %FunctionSetPrototype(f, new $Error());
+    }
+    %FunctionSetInstanceClassName(f, 'Error');
+    %SetProperty(f.prototype, 'constructor', f, DONT_ENUM);
+    %SetProperty(f.prototype, "name", name, DONT_ENUM);
+    %SetCode(f, function(m) {
+      if (%_IsConstructCall()) {
+        // Define all the expected properties directly on the error
+        // object. This avoids going through getters and setters defined
+        // on prototype objects.
+        %IgnoreAttributesAndSetProperty(this, 'stack', void 0, DONT_ENUM);
+        if (!IS_UNDEFINED(m)) {
+          %IgnoreAttributesAndSetProperty(
+            this, 'message', ToString(m), DONT_ENUM);
+        }
+        captureStackTrace(this, f);
+      } else {
+        return new f(m);
+      }
+    });
+    %SetNativeFlag(f);
+  };
+
+  DefineError(function Error() { });
+  DefineError(function TypeError() { });
+  DefineError(function RangeError() { });
+  DefineError(function SyntaxError() { });
+  DefineError(function ReferenceError() { });
+  DefineError(function EvalError() { });
+  DefineError(function URIError() { });
+}
+
+SetUpError();
+
+$Error.captureStackTrace = captureStackTrace;
+
+%SetProperty($Error.prototype, 'message', '', DONT_ENUM);
+
+// Global list of error objects visited during ErrorToString. This is
+// used to detect cycles in error toString formatting.
+var visited_errors = new InternalArray();
+var cyclic_error_marker = new $Object();
+
+function GetPropertyWithoutInvokingMonkeyGetters(error, name) {
+  // Climb the prototype chain until we find the holder.
+  while (error && !%HasLocalProperty(error, name)) {
+    error = %GetPrototype(error);
+  }
+  if (error === null) return void 0;
+  if (!IS_OBJECT(error)) return error[name];
+  // If the property is an accessor on one of the predefined errors that can be
+  // generated statically by the compiler, don't touch it. This is to address
+  // http://code.google.com/p/chromium/issues/detail?id=69187
+  var desc = %GetOwnProperty(error, name);
+  if (desc && desc[IS_ACCESSOR_INDEX]) {
+    var isName = name === "name";
+    if (error === $ReferenceError.prototype)
+      return isName ? "ReferenceError" : void 0;
+    if (error === $SyntaxError.prototype)
+      return isName ? "SyntaxError" : void 0;
+    if (error === $TypeError.prototype)
+      return isName ? "TypeError" : void 0;
+  }
+  // Otherwise, read normally.
+  return error[name];
+}
+
+function ErrorToStringDetectCycle(error) {
+  if (!%PushIfAbsent(visited_errors, error)) throw cyclic_error_marker;
+  try {
+    var name = GetPropertyWithoutInvokingMonkeyGetters(error, "name");
+    name = IS_UNDEFINED(name) ? "Error" : TO_STRING_INLINE(name);
+    var message = GetPropertyWithoutInvokingMonkeyGetters(error, "message");
+    message = IS_UNDEFINED(message) ? "" : TO_STRING_INLINE(message);
+    if (name === "") return message;
+    if (message === "") return name;
+    return name + ": " + message;
+  } finally {
+    visited_errors.length = visited_errors.length - 1;
+  }
+}
+
+function ErrorToString() {
+  if (!IS_SPEC_OBJECT(this)) {
+    throw MakeTypeError("called_on_non_object", ["Error.prototype.toString"]);
+  }
+
+  try {
+    return ErrorToStringDetectCycle(this);
+  } catch(e) {
+    // If this error message was encountered already return the empty
+    // string for it instead of recursively formatting it.
+    if (e === cyclic_error_marker) {
+      return '';
+    }
+    throw e;
+  }
+}
+
+
+InstallFunctions($Error.prototype, DONT_ENUM, ['toString', ErrorToString]);
+
+// Boilerplate for exceptions for stack overflows. Used from
+// Isolate::StackOverflow().
+function SetUpStackOverflowBoilerplate() {
+  var boilerplate = MakeRangeError('stack_overflow', []);
+
+  var error_string = boilerplate.name + ": " + boilerplate.message;
+
+  // The raw stack trace is stored as a hidden property on the holder of this
+  // getter, which may not be the same as the receiver.  Find the holder to
+  // retrieve the raw stack trace and then turn this accessor pair into a
+  // data property.
+  var getter = function() {
+    var holder = this;
+    while (!IS_ERROR(holder)) {
+      holder = %GetPrototype(holder);
+      if (IS_NULL(holder)) return MakeSyntaxError('illegal_access', []);
+    }
+    var stack = %GetAndClearOverflowedStackTrace(holder);
+    // We may not have captured any stack trace.
+    if (IS_UNDEFINED(stack)) return stack;
+
+    var result = FormatStackTrace(holder, error_string, GetStackFrames(stack));
+    // Replace this accessor with a data property.
+    %DefineOrRedefineDataProperty(holder, 'stack', result, NONE);
+    return result;
+  };
+
+  // Set the 'stack' property on the receiver.  If the receiver is the same as
+  // holder of this setter, the accessor pair is turned into a data property.
+  var setter = function(v) {
+    %DefineOrRedefineDataProperty(this, 'stack', v, NONE);
+    // Tentatively clear the hidden property. If the receiver is the same as
+    // holder, we release the raw stack trace this way.
+    %GetAndClearOverflowedStackTrace(this);
+  };
+
+  %DefineOrRedefineAccessorProperty(
+      boilerplate, 'stack', getter, setter, DONT_ENUM);
+
+  return boilerplate;
+}
+
+var kStackOverflowBoilerplate = SetUpStackOverflowBoilerplate();