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// Copyright 2006-2008 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.
#include "v8.h"
#include "accessors.h"
#include "execution.h"
#include "factory.h"
#include "scopeinfo.h"
#include "top.h"
#include "zone-inl.h"
namespace v8 {
namespace internal {
template <class C>
static C* FindInPrototypeChain(Object* obj, bool* found_it) {
ASSERT(!*found_it);
while (!Is<C>(obj)) {
if (obj == Heap::null_value()) return NULL;
obj = obj->GetPrototype();
}
*found_it = true;
return C::cast(obj);
}
// Entry point that never should be called.
Object* Accessors::IllegalSetter(JSObject*, Object*, void*) {
UNREACHABLE();
return NULL;
}
Object* Accessors::IllegalGetAccessor(Object* object, void*) {
UNREACHABLE();
return object;
}
Object* Accessors::ReadOnlySetAccessor(JSObject*, Object* value, void*) {
// According to ECMA-262, section 8.6.2.2, page 28, setting
// read-only properties must be silently ignored.
return value;
}
//
// Accessors::ArrayLength
//
Object* Accessors::ArrayGetLength(Object* object, void*) {
// Traverse the prototype chain until we reach an array.
bool found_it = false;
JSArray* holder = FindInPrototypeChain<JSArray>(object, &found_it);
if (!found_it) return Smi::FromInt(0);
return holder->length();
}
// The helper function will 'flatten' Number objects.
Object* Accessors::FlattenNumber(Object* value) {
if (value->IsNumber() || !value->IsJSValue()) return value;
JSValue* wrapper = JSValue::cast(value);
ASSERT(
Top::context()->global_context()->number_function()->has_initial_map());
Map* number_map =
Top::context()->global_context()->number_function()->initial_map();
if (wrapper->map() == number_map) return wrapper->value();
return value;
}
Object* Accessors::ArraySetLength(JSObject* object, Object* value, void*) {
value = FlattenNumber(value);
// Need to call methods that may trigger GC.
HandleScope scope;
// Protect raw pointers.
Handle<JSObject> object_handle(object);
Handle<Object> value_handle(value);
bool has_exception;
Handle<Object> uint32_v = Execution::ToUint32(value_handle, &has_exception);
if (has_exception) return Failure::Exception();
Handle<Object> number_v = Execution::ToNumber(value_handle, &has_exception);
if (has_exception) return Failure::Exception();
// Restore raw pointers,
object = *object_handle;
value = *value_handle;
if (uint32_v->Number() == number_v->Number()) {
if (object->IsJSArray()) {
return JSArray::cast(object)->SetElementsLength(*uint32_v);
} else {
// This means one of the object's prototypes is a JSArray and
// the object does not have a 'length' property.
// Calling SetProperty causes an infinite loop.
return object->IgnoreAttributesAndSetLocalProperty(Heap::length_symbol(),
value, NONE);
}
}
return Top::Throw(*Factory::NewRangeError("invalid_array_length",
HandleVector<Object>(NULL, 0)));
}
const AccessorDescriptor Accessors::ArrayLength = {
ArrayGetLength,
ArraySetLength,
0
};
//
// Accessors::StringLength
//
Object* Accessors::StringGetLength(Object* object, void*) {
Object* value = object;
if (object->IsJSValue()) value = JSValue::cast(object)->value();
if (value->IsString()) return Smi::FromInt(String::cast(value)->length());
// If object is not a string we return 0 to be compatible with WebKit.
// Note: Firefox returns the length of ToString(object).
return Smi::FromInt(0);
}
const AccessorDescriptor Accessors::StringLength = {
StringGetLength,
IllegalSetter,
0
};
//
// Accessors::ScriptSource
//
Object* Accessors::ScriptGetSource(Object* object, void*) {
Object* script = JSValue::cast(object)->value();
return Script::cast(script)->source();
}
const AccessorDescriptor Accessors::ScriptSource = {
ScriptGetSource,
IllegalSetter,
0
};
//
// Accessors::ScriptName
//
Object* Accessors::ScriptGetName(Object* object, void*) {
Object* script = JSValue::cast(object)->value();
return Script::cast(script)->name();
}
const AccessorDescriptor Accessors::ScriptName = {
ScriptGetName,
IllegalSetter,
0
};
//
// Accessors::ScriptId
//
Object* Accessors::ScriptGetId(Object* object, void*) {
Object* script = JSValue::cast(object)->value();
return Script::cast(script)->id();
}
const AccessorDescriptor Accessors::ScriptId = {
ScriptGetId,
IllegalSetter,
0
};
//
// Accessors::ScriptLineOffset
//
Object* Accessors::ScriptGetLineOffset(Object* object, void*) {
Object* script = JSValue::cast(object)->value();
return Script::cast(script)->line_offset();
}
const AccessorDescriptor Accessors::ScriptLineOffset = {
ScriptGetLineOffset,
IllegalSetter,
0
};
//
// Accessors::ScriptColumnOffset
//
Object* Accessors::ScriptGetColumnOffset(Object* object, void*) {
Object* script = JSValue::cast(object)->value();
return Script::cast(script)->column_offset();
}
const AccessorDescriptor Accessors::ScriptColumnOffset = {
ScriptGetColumnOffset,
IllegalSetter,
0
};
//
// Accessors::ScriptData
//
Object* Accessors::ScriptGetData(Object* object, void*) {
Object* script = JSValue::cast(object)->value();
return Script::cast(script)->data();
}
const AccessorDescriptor Accessors::ScriptData = {
ScriptGetData,
IllegalSetter,
0
};
//
// Accessors::ScriptType
//
Object* Accessors::ScriptGetType(Object* object, void*) {
Object* script = JSValue::cast(object)->value();
return Script::cast(script)->type();
}
const AccessorDescriptor Accessors::ScriptType = {
ScriptGetType,
IllegalSetter,
0
};
//
// Accessors::ScriptCompilationType
//
Object* Accessors::ScriptGetCompilationType(Object* object, void*) {
Object* script = JSValue::cast(object)->value();
return Script::cast(script)->compilation_type();
}
const AccessorDescriptor Accessors::ScriptCompilationType = {
ScriptGetCompilationType,
IllegalSetter,
0
};
//
// Accessors::ScriptGetLineEnds
//
Object* Accessors::ScriptGetLineEnds(Object* object, void*) {
HandleScope scope;
Handle<Script> script(Script::cast(JSValue::cast(object)->value()));
InitScriptLineEnds(script);
ASSERT(script->line_ends()->IsFixedArray());
Handle<FixedArray> line_ends(FixedArray::cast(script->line_ends()));
Handle<FixedArray> copy = Factory::CopyFixedArray(line_ends);
Handle<JSArray> js_array = Factory::NewJSArrayWithElements(copy);
return *js_array;
}
const AccessorDescriptor Accessors::ScriptLineEnds = {
ScriptGetLineEnds,
IllegalSetter,
0
};
//
// Accessors::ScriptGetContextData
//
Object* Accessors::ScriptGetContextData(Object* object, void*) {
Object* script = JSValue::cast(object)->value();
return Script::cast(script)->context_data();
}
const AccessorDescriptor Accessors::ScriptContextData = {
ScriptGetContextData,
IllegalSetter,
0
};
//
// Accessors::ScriptGetEvalFromScript
//
Object* Accessors::ScriptGetEvalFromScript(Object* object, void*) {
Object* script = JSValue::cast(object)->value();
if (!Script::cast(script)->eval_from_shared()->IsUndefined()) {
Handle<SharedFunctionInfo> eval_from_shared(
SharedFunctionInfo::cast(Script::cast(script)->eval_from_shared()));
if (eval_from_shared->script()->IsScript()) {
Handle<Script> eval_from_script(Script::cast(eval_from_shared->script()));
return *GetScriptWrapper(eval_from_script);
}
}
return Heap::undefined_value();
}
const AccessorDescriptor Accessors::ScriptEvalFromScript = {
ScriptGetEvalFromScript,
IllegalSetter,
0
};
//
// Accessors::ScriptGetEvalFromScriptPosition
//
Object* Accessors::ScriptGetEvalFromScriptPosition(Object* object, void*) {
HandleScope scope;
Handle<Script> script(Script::cast(JSValue::cast(object)->value()));
// If this is not a script compiled through eval there is no eval position.
int compilation_type = Smi::cast(script->compilation_type())->value();
if (compilation_type != Script::COMPILATION_TYPE_EVAL) {
return Heap::undefined_value();
}
// Get the function from where eval was called and find the source position
// from the instruction offset.
Handle<Code> code(SharedFunctionInfo::cast(
script->eval_from_shared())->code());
return Smi::FromInt(code->SourcePosition(code->instruction_start() +
script->eval_from_instructions_offset()->value()));
}
const AccessorDescriptor Accessors::ScriptEvalFromScriptPosition = {
ScriptGetEvalFromScriptPosition,
IllegalSetter,
0
};
//
// Accessors::ScriptGetEvalFromFunctionName
//
Object* Accessors::ScriptGetEvalFromFunctionName(Object* object, void*) {
Object* script = JSValue::cast(object)->value();
Handle<SharedFunctionInfo> shared(SharedFunctionInfo::cast(
Script::cast(script)->eval_from_shared()));
// Find the name of the function calling eval.
if (!shared->name()->IsUndefined()) {
return shared->name();
} else {
return shared->inferred_name();
}
}
const AccessorDescriptor Accessors::ScriptEvalFromFunctionName = {
ScriptGetEvalFromFunctionName,
IllegalSetter,
0
};
//
// Accessors::FunctionPrototype
//
Object* Accessors::FunctionGetPrototype(Object* object, void*) {
bool found_it = false;
JSFunction* function = FindInPrototypeChain<JSFunction>(object, &found_it);
if (!found_it) return Heap::undefined_value();
if (!function->has_prototype()) {
Object* prototype = Heap::AllocateFunctionPrototype(function);
if (prototype->IsFailure()) return prototype;
Object* result = function->SetPrototype(prototype);
if (result->IsFailure()) return result;
}
return function->prototype();
}
Object* Accessors::FunctionSetPrototype(JSObject* object,
Object* value,
void*) {
bool found_it = false;
JSFunction* function = FindInPrototypeChain<JSFunction>(object, &found_it);
if (!found_it) return Heap::undefined_value();
if (function->has_initial_map()) {
// If the function has allocated the initial map
// replace it with a copy containing the new prototype.
Object* new_map = function->initial_map()->CopyDropTransitions();
if (new_map->IsFailure()) return new_map;
function->set_initial_map(Map::cast(new_map));
}
Object* prototype = function->SetPrototype(value);
if (prototype->IsFailure()) return prototype;
ASSERT(function->prototype() == value);
return function;
}
const AccessorDescriptor Accessors::FunctionPrototype = {
FunctionGetPrototype,
FunctionSetPrototype,
0
};
//
// Accessors::FunctionLength
//
Object* Accessors::FunctionGetLength(Object* object, void*) {
bool found_it = false;
JSFunction* function = FindInPrototypeChain<JSFunction>(object, &found_it);
if (!found_it) return Smi::FromInt(0);
// Check if already compiled.
if (!function->is_compiled()) {
// If the function isn't compiled yet, the length is not computed
// correctly yet. Compile it now and return the right length.
HandleScope scope;
Handle<SharedFunctionInfo> shared(function->shared());
if (!CompileLazyShared(shared, KEEP_EXCEPTION)) {
return Failure::Exception();
}
return Smi::FromInt(shared->length());
} else {
return Smi::FromInt(function->shared()->length());
}
}
const AccessorDescriptor Accessors::FunctionLength = {
FunctionGetLength,
ReadOnlySetAccessor,
0
};
//
// Accessors::FunctionName
//
Object* Accessors::FunctionGetName(Object* object, void*) {
bool found_it = false;
JSFunction* holder = FindInPrototypeChain<JSFunction>(object, &found_it);
if (!found_it) return Heap::undefined_value();
return holder->shared()->name();
}
const AccessorDescriptor Accessors::FunctionName = {
FunctionGetName,
ReadOnlySetAccessor,
0
};
//
// Accessors::FunctionArguments
//
Object* Accessors::FunctionGetArguments(Object* object, void*) {
HandleScope scope;
bool found_it = false;
JSFunction* holder = FindInPrototypeChain<JSFunction>(object, &found_it);
if (!found_it) return Heap::undefined_value();
Handle<JSFunction> function(holder);
// Find the top invocation of the function by traversing frames.
for (JavaScriptFrameIterator it; !it.done(); it.Advance()) {
// Skip all frames that aren't invocations of the given function.
JavaScriptFrame* frame = it.frame();
if (frame->function() != *function) continue;
// If there is an arguments variable in the stack, we return that.
int index = ScopeInfo<>::StackSlotIndex(frame->code(),
Heap::arguments_symbol());
if (index >= 0) {
Handle<Object> arguments = Handle<Object>(frame->GetExpression(index));
if (!arguments->IsTheHole()) return *arguments;
}
// If there isn't an arguments variable in the stack, we need to
// find the frame that holds the actual arguments passed to the
// function on the stack.
it.AdvanceToArgumentsFrame();
frame = it.frame();
// Get the number of arguments and construct an arguments object
// mirror for the right frame.
const int length = frame->GetProvidedParametersCount();
Handle<JSObject> arguments = Factory::NewArgumentsObject(function, length);
Handle<FixedArray> array = Factory::NewFixedArray(length);
// Copy the parameters to the arguments object.
ASSERT(array->length() == length);
for (int i = 0; i < length; i++) array->set(i, frame->GetParameter(i));
arguments->set_elements(*array);
// Return the freshly allocated arguments object.
return *arguments;
}
// No frame corresponding to the given function found. Return null.
return Heap::null_value();
}
const AccessorDescriptor Accessors::FunctionArguments = {
FunctionGetArguments,
ReadOnlySetAccessor,
0
};
//
// Accessors::FunctionCaller
//
Object* Accessors::FunctionGetCaller(Object* object, void*) {
HandleScope scope;
bool found_it = false;
JSFunction* holder = FindInPrototypeChain<JSFunction>(object, &found_it);
if (!found_it) return Heap::undefined_value();
Handle<JSFunction> function(holder);
// Find the top invocation of the function by traversing frames.
for (JavaScriptFrameIterator it; !it.done(); it.Advance()) {
// Skip all frames that aren't invocations of the given function.
if (it.frame()->function() != *function) continue;
// Once we have found the frame, we need to go to the caller
// frame. This may require skipping through a number of top-level
// frames, e.g. frames for scripts not functions.
while (true) {
it.Advance();
if (it.done()) return Heap::null_value();
JSFunction* caller = JSFunction::cast(it.frame()->function());
if (!caller->shared()->is_toplevel()) return caller;
}
}
// No frame corresponding to the given function found. Return null.
return Heap::null_value();
}
const AccessorDescriptor Accessors::FunctionCaller = {
FunctionGetCaller,
ReadOnlySetAccessor,
0
};
//
// Accessors::ObjectPrototype
//
Object* Accessors::ObjectGetPrototype(Object* receiver, void*) {
Object* current = receiver->GetPrototype();
while (current->IsJSObject() &&
JSObject::cast(current)->map()->is_hidden_prototype()) {
current = current->GetPrototype();
}
return current;
}
Object* Accessors::ObjectSetPrototype(JSObject* receiver,
Object* value,
void*) {
const bool skip_hidden_prototypes = true;
// To be consistent with other Set functions, return the value.
return receiver->SetPrototype(value, skip_hidden_prototypes);
}
const AccessorDescriptor Accessors::ObjectPrototype = {
ObjectGetPrototype,
ObjectSetPrototype,
0
};
} } // namespace v8::internal