// Copyright 2012 the V8 project authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
#ifndef V8_ARGUMENTS_H_
#define V8_ARGUMENTS_H_
#include "src/allocation.h"
#include "src/isolate.h"
namespace v8 {
namespace internal {
// Arguments provides access to runtime call parameters.
//
// It uses the fact that the instance fields of Arguments
// (length_, arguments_) are "overlayed" with the parameters
// (no. of parameters, and the parameter pointer) passed so
// that inside the C++ function, the parameters passed can
// be accessed conveniently:
//
// Object* Runtime_function(Arguments args) {
// ... use args[i] here ...
// }
//
// Note that length_ (whose value is in the integer range) is defined
// as intptr_t to provide endian-neutrality on 64-bit archs.
class Arguments BASE_EMBEDDED {
public:
Arguments(int length, Object** arguments)
: length_(length), arguments_(arguments) { }
Object*& operator[] (int index) {
DCHECK(0 <= index && index < length_);
return *(reinterpret_cast<Object**>(reinterpret_cast<intptr_t>(arguments_) -
index * kPointerSize));
}
template <class S> Handle<S> at(int index) {
Object** value = &((*this)[index]);
// This cast checks that the object we're accessing does indeed have the
// expected type.
S::cast(*value);
return Handle<S>(reinterpret_cast<S**>(value));
}
int smi_at(int index) {
return Smi::cast((*this)[index])->value();
}
double number_at(int index) {
return (*this)[index]->Number();
}
// Get the total number of arguments including the receiver.
int length() const { return static_cast<int>(length_); }
Object** arguments() { return arguments_; }
private:
intptr_t length_;
Object** arguments_;
};
// For each type of callback, we have a list of arguments
// They are used to generate the Call() functions below
// These aren't included in the list as they have duplicate signatures
// F(NamedPropertyEnumeratorCallback, ...)
#define FOR_EACH_CALLBACK_TABLE_MAPPING_0(F) \
F(IndexedPropertyEnumeratorCallback, v8::Array) \
#define FOR_EACH_CALLBACK_TABLE_MAPPING_1(F) \
F(NamedPropertyGetterCallback, v8::Value, v8::Local<v8::String>) \
F(AccessorNameGetterCallback, v8::Value, v8::Local<v8::Name>) \
F(NamedPropertyQueryCallback, \
v8::Integer, \
v8::Local<v8::String>) \
F(NamedPropertyDeleterCallback, \
v8::Boolean, \
v8::Local<v8::String>) \
F(IndexedPropertyGetterCallback, \
v8::Value, \
uint32_t) \
F(IndexedPropertyQueryCallback, \
v8::Integer, \
uint32_t) \
F(IndexedPropertyDeleterCallback, \
v8::Boolean, \
uint32_t) \
#define FOR_EACH_CALLBACK_TABLE_MAPPING_2(F) \
F(NamedPropertySetterCallback, \
v8::Value, \
v8::Local<v8::String>, \
v8::Local<v8::Value>) \
F(IndexedPropertySetterCallback, \
v8::Value, \
uint32_t, \
v8::Local<v8::Value>) \
#define FOR_EACH_CALLBACK_TABLE_MAPPING_2_VOID_RETURN(F) \
F(AccessorNameSetterCallback, \
void, \
v8::Local<v8::Name>, \
v8::Local<v8::Value>) \
// Custom arguments replicate a small segment of stack that can be
// accessed through an Arguments object the same way the actual stack
// can.
template<int kArrayLength>
class CustomArgumentsBase : public Relocatable {
public:
virtual inline void IterateInstance(ObjectVisitor* v) {
v->VisitPointers(values_, values_ + kArrayLength);
}
protected:
inline Object** begin() { return values_; }
explicit inline CustomArgumentsBase(Isolate* isolate)
: Relocatable(isolate) {}
Object* values_[kArrayLength];
};
template<typename T>
class CustomArguments : public CustomArgumentsBase<T::kArgsLength> {
public:
static const int kReturnValueOffset = T::kReturnValueIndex;
typedef CustomArgumentsBase<T::kArgsLength> Super;
~CustomArguments() {
this->begin()[kReturnValueOffset] =
reinterpret_cast<Object*>(kHandleZapValue);
}
protected:
explicit inline CustomArguments(Isolate* isolate) : Super(isolate) {}
template<typename V>
v8::Handle<V> GetReturnValue(Isolate* isolate);
inline Isolate* isolate() {
return reinterpret_cast<Isolate*>(this->begin()[T::kIsolateIndex]);
}
};
class PropertyCallbackArguments
: public CustomArguments<PropertyCallbackInfo<Value> > {
public:
typedef PropertyCallbackInfo<Value> T;
typedef CustomArguments<T> Super;
static const int kArgsLength = T::kArgsLength;
static const int kThisIndex = T::kThisIndex;
static const int kHolderIndex = T::kHolderIndex;
static const int kDataIndex = T::kDataIndex;
static const int kReturnValueDefaultValueIndex =
T::kReturnValueDefaultValueIndex;
static const int kIsolateIndex = T::kIsolateIndex;
PropertyCallbackArguments(Isolate* isolate,
Object* data,
Object* self,
JSObject* holder)
: Super(isolate) {
Object** values = this->begin();
values[T::kThisIndex] = self;
values[T::kHolderIndex] = holder;
values[T::kDataIndex] = data;
values[T::kIsolateIndex] = reinterpret_cast<Object*>(isolate);
// Here the hole is set as default value.
// It cannot escape into js as it's remove in Call below.
values[T::kReturnValueDefaultValueIndex] =
isolate->heap()->the_hole_value();
values[T::kReturnValueIndex] = isolate->heap()->the_hole_value();
DCHECK(values[T::kHolderIndex]->IsHeapObject());
DCHECK(values[T::kIsolateIndex]->IsSmi());
}
/*
* The following Call functions wrap the calling of all callbacks to handle
* calling either the old or the new style callbacks depending on which one
* has been registered.
* For old callbacks which return an empty handle, the ReturnValue is checked
* and used if it's been set to anything inside the callback.
* New style callbacks always use the return value.
*/
#define WRITE_CALL_0(Function, ReturnValue) \
v8::Handle<ReturnValue> Call(Function f); \
#define WRITE_CALL_1(Function, ReturnValue, Arg1) \
v8::Handle<ReturnValue> Call(Function f, Arg1 arg1); \
#define WRITE_CALL_2(Function, ReturnValue, Arg1, Arg2) \
v8::Handle<ReturnValue> Call(Function f, Arg1 arg1, Arg2 arg2); \
#define WRITE_CALL_2_VOID(Function, ReturnValue, Arg1, Arg2) \
void Call(Function f, Arg1 arg1, Arg2 arg2); \
FOR_EACH_CALLBACK_TABLE_MAPPING_0(WRITE_CALL_0)
FOR_EACH_CALLBACK_TABLE_MAPPING_1(WRITE_CALL_1)
FOR_EACH_CALLBACK_TABLE_MAPPING_2(WRITE_CALL_2)
FOR_EACH_CALLBACK_TABLE_MAPPING_2_VOID_RETURN(WRITE_CALL_2_VOID)
#undef WRITE_CALL_0
#undef WRITE_CALL_1
#undef WRITE_CALL_2
#undef WRITE_CALL_2_VOID
};
class FunctionCallbackArguments
: public CustomArguments<FunctionCallbackInfo<Value> > {
public:
typedef FunctionCallbackInfo<Value> T;
typedef CustomArguments<T> Super;
static const int kArgsLength = T::kArgsLength;
static const int kHolderIndex = T::kHolderIndex;
static const int kDataIndex = T::kDataIndex;
static const int kReturnValueDefaultValueIndex =
T::kReturnValueDefaultValueIndex;
static const int kIsolateIndex = T::kIsolateIndex;
static const int kCalleeIndex = T::kCalleeIndex;
static const int kContextSaveIndex = T::kContextSaveIndex;
FunctionCallbackArguments(internal::Isolate* isolate,
internal::Object* data,
internal::JSFunction* callee,
internal::Object* holder,
internal::Object** argv,
int argc,
bool is_construct_call)
: Super(isolate),
argv_(argv),
argc_(argc),
is_construct_call_(is_construct_call) {
Object** values = begin();
values[T::kDataIndex] = data;
values[T::kCalleeIndex] = callee;
values[T::kHolderIndex] = holder;
values[T::kContextSaveIndex] = isolate->heap()->the_hole_value();
values[T::kIsolateIndex] = reinterpret_cast<internal::Object*>(isolate);
// Here the hole is set as default value.
// It cannot escape into js as it's remove in Call below.
values[T::kReturnValueDefaultValueIndex] =
isolate->heap()->the_hole_value();
values[T::kReturnValueIndex] = isolate->heap()->the_hole_value();
DCHECK(values[T::kCalleeIndex]->IsJSFunction());
DCHECK(values[T::kHolderIndex]->IsHeapObject());
DCHECK(values[T::kIsolateIndex]->IsSmi());
}
/*
* The following Call function wraps the calling of all callbacks to handle
* calling either the old or the new style callbacks depending on which one
* has been registered.
* For old callbacks which return an empty handle, the ReturnValue is checked
* and used if it's been set to anything inside the callback.
* New style callbacks always use the return value.
*/
v8::Handle<v8::Value> Call(FunctionCallback f);
private:
internal::Object** argv_;
int argc_;
bool is_construct_call_;
};
double ClobberDoubleRegisters(double x1, double x2, double x3, double x4);
#ifdef DEBUG
#define CLOBBER_DOUBLE_REGISTERS() ClobberDoubleRegisters(1, 2, 3, 4);
#else
#define CLOBBER_DOUBLE_REGISTERS()
#endif
#define DECLARE_RUNTIME_FUNCTION(Name) \
Object* Name(int args_length, Object** args_object, Isolate* isolate)
#define RUNTIME_FUNCTION_RETURNS_TYPE(Type, Name) \
static INLINE(Type __RT_impl_##Name(Arguments args, Isolate* isolate)); \
Type Name(int args_length, Object** args_object, Isolate* isolate) { \
CLOBBER_DOUBLE_REGISTERS(); \
Arguments args(args_length, args_object); \
return __RT_impl_##Name(args, isolate); \
} \
static Type __RT_impl_##Name(Arguments args, Isolate* isolate)
#define RUNTIME_FUNCTION(Name) RUNTIME_FUNCTION_RETURNS_TYPE(Object*, Name)
#define RUNTIME_FUNCTION_RETURN_PAIR(Name) \
RUNTIME_FUNCTION_RETURNS_TYPE(ObjectPair, Name)
#define RUNTIME_ARGUMENTS(isolate, args) \
args.length(), args.arguments(), isolate
} } // namespace v8::internal
#endif // V8_ARGUMENTS_H_