runtime.cc.svn-base

Google浏览器V8内核代码

      // global object add the property locally.  We take special
      // precautions to always add it as a local property even in case
      // of callbacks in the prototype chain (this rules out using
      // SetProperty).  Also, we must use the handle-based version to
      // avoid GC issues.
      AddProperty(global, name, value, attributes);
    }
  }
  // Done.
  return Heap::undefined_value();
}


static Object* Runtime_DeclareContextSlot(Arguments args) {
  HandleScope scope;
  ASSERT(args.length() == 5);

  // args[0] is result (TOS)
  CONVERT_ARG_CHECKED(Context, context, 1);
  Handle<String> name(String::cast(args[2]));
  PropertyAttributes mode =
      static_cast<PropertyAttributes>(Smi::cast(args[3])->value());
  ASSERT(mode == READ_ONLY || mode == NONE);
  Handle<Object> initial_value(args[4]);

  // Declarations are always done in the function context.
  context = Handle<Context>(context->fcontext());

  int index;
  PropertyAttributes attributes;
  ContextLookupFlags flags = DONT_FOLLOW_CHAINS;
  Handle<Object> context_obj =
      context->Lookup(name, flags, &index, &attributes);

  if (attributes != ABSENT) {
    // The name was declared before; check for conflicting
    // re-declarations: This is similar to the code in parser.cc in
    // the AstBuildingParser::Declare function.
    if (((attributes & READ_ONLY) != 0) || (mode == READ_ONLY)) {
      // Functions are not read-only.
      ASSERT(mode != READ_ONLY || initial_value->IsTheHole());
      const char* type = ((attributes & READ_ONLY) != 0) ? "const" : "var";
      return ThrowRedeclarationError(type, name);
    }

    // Initialize it if necessary.
    if (*initial_value != NULL) {
      if (index >= 0) {
        // The variable or constant context slot should always be in
        // the function context; not in any outer context nor in the
        // arguments object.
        ASSERT(context_obj.is_identical_to(context));
        if (((attributes & READ_ONLY) == 0) ||
            context->get(index)->IsTheHole()) {
          context->set(index, *initial_value);
        }
      } else {
        // Slow case: The property is not in the FixedArray part of the context.
        Handle<JSObject> context_ext = Handle<JSObject>::cast(context_obj);
        SetProperty(context_ext, name, initial_value, mode);
      }
    }
    return args[0];  // return TOS
  }

  // The property is not in the function context. It needs to be "declared"
  // in the function context's extension context, or in the global context.
  Handle<JSObject> context_ext;
  if (context->extension() != NULL) {
    // The function context's extension context exists - use it.
    context_ext = Handle<JSObject>(context->extension());
  } else {
    // The function context's extension context does not exists - allocate it.
    context_ext = Factory::NewJSObject(Top::context_extension_function());
    // And store it in the extension slot.
    context->set_extension(*context_ext);
  }
  ASSERT(*context_ext != NULL);

  // Declare the property by setting it to the initial value if provided,
  // or undefined, and use the correct mode (e.g. READ_ONLY attribute for
  // constant declarations).
  ASSERT(!context_ext->HasLocalProperty(*name));
  Handle<Object> value(Heap::undefined_value());
  if (*initial_value != NULL) value = initial_value;
  SetProperty(context_ext, name, value, mode);
  ASSERT(context_ext->GetLocalPropertyAttribute(*name) == mode);
  return args[0];  // return TOS
}


static Object* Runtime_InitializeVarGlobal(Arguments args) {
  NoHandleAllocation nha;

  // Determine if we need to assign to the variable if it already
  // exists (based on the number of arguments).
  RUNTIME_ASSERT(args.length() == 1 || args.length() == 2);
  bool assign = args.length() == 2;

  CONVERT_ARG_CHECKED(String, name, 0);
  GlobalObject* global = Top::context()->global();

  // According to ECMA-262, section 12.2, page 62, the property must
  // not be deletable.
  PropertyAttributes attributes = DONT_DELETE;

  // Lookup the property locally in the global object. If it isn't
  // there, we add the property and take special precautions to always
  // add it as a local property even in case of callbacks in the
  // prototype chain (this rules out using SetProperty).
  LookupResult lookup;
  global->LocalLookup(*name, &lookup);
  if (!lookup.IsProperty()) {
    Object* value = (assign) ? args[1] : Heap::undefined_value();
    return global->AddProperty(*name, value, attributes);
  }

  // Determine if this is a redeclaration of something read-only.
  if (lookup.IsReadOnly()) {
    return ThrowRedeclarationError("const", name);
  }

  // Determine if this is a redeclaration of an intercepted read-only
  // property and figure out if the property exists at all.
  bool found = true;
  PropertyType type = lookup.type();
  if (type == INTERCEPTOR) {
    PropertyAttributes intercepted = global->GetPropertyAttribute(*name);
    if (intercepted == ABSENT) {
      // The interceptor claims the property isn't there. We need to
      // make sure to introduce it.
      found = false;
    } else if ((intercepted & READ_ONLY) != 0) {
      // The property is present, but read-only. Since we're trying to
      // overwrite it with a variable declaration we must throw a
      // re-declaration error.
      return ThrowRedeclarationError("const", name);
    }
    // Restore global object from context (in case of GC).
    global = Top::context()->global();
  }

  if (found && !assign) {
    // The global property is there and we're not assigning any value
    // to it. Just return.
    return Heap::undefined_value();
  }

  // Assign the value (or undefined) to the property.
  Object* value = (assign) ? args[1] : Heap::undefined_value();
  return global->SetProperty(&lookup, *name, value, attributes);
}


static Object* Runtime_InitializeConstGlobal(Arguments args) {
  // All constants are declared with an initial value. The name
  // of the constant is the first argument and the initial value
  // is the second.
  RUNTIME_ASSERT(args.length() == 2);
  CONVERT_ARG_CHECKED(String, name, 0);
  Handle<Object> value = args.at<Object>(1);

  // Get the current global object from top.
  GlobalObject* global = Top::context()->global();

  // According to ECMA-262, section 12.2, page 62, the property must
  // not be deletable. Since it's a const, it must be READ_ONLY too.
  PropertyAttributes attributes =
      static_cast<PropertyAttributes>(DONT_DELETE | READ_ONLY);

  // Lookup the property locally in the global object. If it isn't
  // there, we add the property and take special precautions to always
  // add it as a local property even in case of callbacks in the
  // prototype chain (this rules out using SetProperty).
  LookupResult lookup;
  global->LocalLookup(*name, &lookup);
  if (!lookup.IsProperty()) {
    return global->AddProperty(*name, *value, attributes);
  }

  // Determine if this is a redeclaration of something not
  // read-only. In case the result is hidden behind an interceptor we
  // need to ask it for the property attributes.
  if (!lookup.IsReadOnly()) {
    if (lookup.type() != INTERCEPTOR) {
      return ThrowRedeclarationError("var", name);
    }

    PropertyAttributes intercepted = global->GetPropertyAttribute(*name);

    // Throw re-declaration error if the intercepted property is present
    // but not read-only.
    if (intercepted != ABSENT && (intercepted & READ_ONLY) == 0) {
      return ThrowRedeclarationError("var", name);
    }

    // Restore global object from context (in case of GC) and continue
    // with setting the value because the property is either absent or
    // read-only. We also have to do redo the lookup.
    global = Top::context()->global();

    // BUG 1213579: Handle the case where we have to set a read-only
    // property through an interceptor and only do it if it's
    // uninitialized, e.g. the hole. Nirk...
    global->SetProperty(*name, *value, attributes);
    return *value;
  }

  // Set the value, but only we're assigning the initial value to a
  // constant. For now, we determine this by checking if the
  // current value is the hole.
  PropertyType type = lookup.type();
  if (type == FIELD) {
    FixedArray* properties = global->properties();
    int index = lookup.GetFieldIndex();
    if (properties->get(index)->IsTheHole()) {
      properties->set(index, *value);
    }
  } else if (type == NORMAL) {
    Dictionary* dictionary = global->property_dictionary();
    int entry = lookup.GetDictionaryEntry();
    if (dictionary->ValueAt(entry)->IsTheHole()) {
      dictionary->ValueAtPut(entry, *value);
    }
  } else {
    // Ignore re-initialization of constants that have already been
    // assigned a function value.
    ASSERT(lookup.IsReadOnly() && type == CONSTANT_FUNCTION);
  }

  // Use the set value as the result of the operation.
  return *value;
}


static Object* Runtime_InitializeConstContextSlot(Arguments args) {
  HandleScope scope;
  ASSERT(args.length() == 3);

  Handle<Object> value(args[0]);
  ASSERT(!value->IsTheHole());
  CONVERT_ARG_CHECKED(Context, context, 1);
  Handle<String> name(String::cast(args[2]));

  // Initializations are always done in the function context.
  context = Handle<Context>(context->fcontext());

  int index;
  PropertyAttributes attributes;
  ContextLookupFlags flags = DONT_FOLLOW_CHAINS;
  Handle<Object> context_obj =
      context->Lookup(name, flags, &index, &attributes);

  // The property should always be present. It is always declared
  // before being initialized through DeclareContextSlot.
  ASSERT(attributes != ABSENT && (attributes & READ_ONLY) != 0);

  // If the slot is in the context, we set it but only if it hasn't
  // been set before.
  if (index >= 0) {
    // The constant context slot should always be in the function
    // context; not in any outer context nor in the arguments object.
    ASSERT(context_obj.is_identical_to(context));
    if (context->get(index)->IsTheHole()) {
      context->set(index, *value);
    }
    return *value;
  }

  // Otherwise, the slot must be in a JS object extension.
  Handle<JSObject> context_ext(JSObject::cast(*context_obj));

  // We must initialize the value only if it wasn't initialized
  // before, e.g. for const declarations in a loop. The property has
  // the hole value if it wasn't initialized yet. NOTE: We cannot use
  // GetProperty() to get the current value as it 'unholes' the value.
  LookupResult lookup;
  context_ext->LocalLookupRealNamedProperty(*name, &lookup);
  ASSERT(lookup.IsProperty());  // the property was declared
  ASSERT(lookup.IsReadOnly());  // and it was declared as read-only

  PropertyType type = lookup.type();
  if (type == FIELD) {
    FixedArray* properties = context_ext->properties();
    int index = lookup.GetFieldIndex();
    if (properties->get(index)->IsTheHole()) {
      properties->set(index, *value);
    }
  } else if (type == NORMAL) {
    Dictionary* dictionary = context_ext->property_dictionary();
    int entry = lookup.GetDictionaryEntry();
    if (dictionary->ValueAt(entry)->IsTheHole()) {
      dictionary->ValueAtPut(entry, *value);
    }
  } else {
    // We should not reach here. Any real, named property should be
    // either a field or a dictionary slot.
    UNREACHABLE();
  }
  return *value;
}


static Object* Runtime_RegExpExec(Arguments args) {
  HandleScope scope;
  ASSERT(args.length() == 3);
  CONVERT_CHECKED(JSRegExp, raw_regexp, args[0]);
  Handle<JSRegExp> regexp(raw_regexp);
  CONVERT_CHECKED(String, raw_subject, args[1]);
  Handle<String> subject(raw_subject);
  Handle<Object> index(args[2]);
  ASSERT(index->IsNumber());
  return *RegExpImpl::JsreExec(regexp, subject, index);
}


static Object* Runtime_RegExpExecGlobal(Arguments args) {
  HandleScope scope;
  ASSERT(args.length() == 2);
  CONVERT_CHECKED(JSRegExp, raw_regexp, args[0]);
  Handle<JSRegExp> regexp(raw_regexp);
  CONVERT_CHECKED(String, raw_subject, args[1]);
  Handle<String> subject(raw_subject);
  return *RegExpImpl::JsreExecGlobal(regexp, subject);
}


static Object* Runtime_MaterializeRegExpLiteral(Arguments args) {
  HandleScope scope;
  ASSERT(args.length() == 4);
  CONVERT_ARG_CHECKED(FixedArray, literals, 0);
  int index = Smi::cast(args[1])->value();
  Handle<String> pattern = args.at<String>(2);
  Handle<String> flags = args.at<String>(3);

  // Get the RegExp function from the literals array.  This is the
  // RegExp function from the context in which the function was
  // created.  We do not use the RegExp function from the current
  // global context because this might be the RegExp function from
  // another context which we should not have access to.
  Handle<JSFunction> constructor =
      Handle<JSFunction>(
          JSFunction::GlobalContextFromLiterals(*literals)->regexp_function());
  // Compute the regular expression literal.
  bool has_pending_exception;
  Handle<Object> regexp =
      RegExpImpl::CreateRegExpLiteral(constructor, pattern, flags,
                                      &has_pending_exception);
  if (has_pending_exception) {
    ASSERT(Top::has_pending_exception());
    return Failure::Exception();
  }
  literals->set(index, *regexp);
  return *regexp;
}


static Object* Runtime_FunctionGetName(Arguments args) {
  NoHandleAllocation ha;
  ASSERT(args.length() == 1);

  CONVERT_CHECKED(JSFunction, f, args[0]);
  return f->shared()->name();
}


static Object* Runtime_FunctionSetName(Arguments args) {
  NoHandleAllocation ha;
  ASSERT(args.length() == 2);

  CONVERT_CHECKED(JSFunction, f, args[0]);
  CONVERT_CHECKED(String, name, args[1]);
  f->shared()->set_name(name);
  return Heap::undefined_value();
}


static Object* Runtime_FunctionGetScript(Arguments args) {
  HandleScope scope;
  ASSERT(args.length() == 1);

  CONVERT_CHECKED(JSFunction, fun, args[0]);
  Handle<Object> script = Handle<Object>(fun->shared()->script());
  if (!script->IsScript()) return Heap::undefined_value();

  return *GetScriptWrapper(Handle<Script>::cast(script));
}


static Object* Runtime_FunctionGetSourceCode(Arguments args) {
  NoHandleAllocation ha;
  ASSERT(args.length() == 1);

  CONVERT_CHECKED(JSFunction, f, args[0]);