// 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/objects.h" #include "src/tracing/trace-event.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) { DCHECK_GE(length_, 0); } Object*& operator[] (int index) { DCHECK_GE(index, 0); DCHECK_LT(static_cast<uint32_t>(index), static_cast<uint32_t>(length_)); return *(reinterpret_cast<Object**>(reinterpret_cast<intptr_t>(arguments_) - index * kPointerSize)); } template <class S = Object> 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::ToInt((*this)[index]); } 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_; } Object** lowest_address() { return &this->operator[](length() - 1); } Object** highest_address() { return &this->operator[](0); } private: intptr_t length_; Object** arguments_; }; 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 // TODO(cbruni): add global flag to check whether any tracing events have been // enabled. #define RUNTIME_FUNCTION_RETURNS_TYPE(Type, Name) \ static V8_INLINE Type __RT_impl_##Name(Arguments args, Isolate* isolate); \ \ V8_NOINLINE static Type Stats_##Name(int args_length, Object** args_object, \ Isolate* isolate) { \ RuntimeCallTimerScope timer(isolate, RuntimeCallCounterId::k##Name); \ TRACE_EVENT0(TRACE_DISABLED_BY_DEFAULT("v8.runtime"), \ "V8.Runtime_" #Name); \ Arguments args(args_length, args_object); \ return __RT_impl_##Name(args, isolate); \ } \ \ Type Name(int args_length, Object** args_object, Isolate* isolate) { \ DCHECK(isolate->context() == nullptr || isolate->context()->IsContext()); \ CLOBBER_DOUBLE_REGISTERS(); \ if (V8_UNLIKELY(FLAG_runtime_stats)) { \ return Stats_##Name(args_length, args_object, isolate); \ } \ 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) } // namespace internal } // namespace v8 #endif // V8_ARGUMENTS_H_