// 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_EXECUTION_ARGUMENTS_H_ #define V8_EXECUTION_ARGUMENTS_H_ #include "src/handles/handles.h" #include "src/logging/counters.h" #include "src/objects/objects.h" #include "src/objects/slots.h" #include "src/tracing/trace-event.h" #include "src/utils/allocation.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. template <ArgumentsType arguments_type> class Arguments { public: Arguments(int length, Address* arguments) : length_(length), arguments_(arguments) { DCHECK_GE(length_, 0); } Object operator[](int index) const { return Object(*address_of_arg_at(index)); } template <class S = Object> inline Handle<S> at(int index) const; inline int smi_at(int index) const; inline int tagged_index_at(int index) const; inline double number_at(int index) const; inline void set_at(int index, Object value) { *address_of_arg_at(index) = value.ptr(); } inline FullObjectSlot slot_at(int index) const { return FullObjectSlot(address_of_arg_at(index)); } inline Address* address_of_arg_at(int index) const { DCHECK_LE(static_cast<uint32_t>(index), static_cast<uint32_t>(length_)); uintptr_t offset = index * kSystemPointerSize; #ifdef V8_REVERSE_JSARGS if (arguments_type == ArgumentsType::kJS) { offset = (length_ - index - 1) * kSystemPointerSize; } #endif return reinterpret_cast<Address*>(reinterpret_cast<Address>(arguments_) - offset); } // Get the total number of arguments including the receiver. int length() const { return static_cast<int>(length_); } // Arguments on the stack are in reverse order (compared to an array). FullObjectSlot first_slot() const { int index = length() - 1; #ifdef V8_REVERSE_JSARGS if (arguments_type == ArgumentsType::kJS) index = 0; #endif return slot_at(index); } FullObjectSlot last_slot() const { int index = 0; #ifdef V8_REVERSE_JSARGS if (arguments_type == ArgumentsType::kJS) index = length() - 1; #endif return slot_at(index); } private: intptr_t length_; Address* arguments_; }; template <ArgumentsType T> template <class S> Handle<S> Arguments<T>::at(int index) const { Handle<Object> obj = Handle<Object>(address_of_arg_at(index)); return Handle<S>::cast(obj); } 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, InternalType, Convert, Name) \ static V8_INLINE InternalType __RT_impl_##Name(RuntimeArguments args, \ Isolate* isolate); \ \ V8_NOINLINE static Type Stats_##Name(int args_length, Address* args_object, \ Isolate* isolate) { \ RuntimeCallTimerScope timer(isolate, RuntimeCallCounterId::k##Name); \ TRACE_EVENT0(TRACE_DISABLED_BY_DEFAULT("v8.runtime"), \ "V8.Runtime_" #Name); \ RuntimeArguments args(args_length, args_object); \ return Convert(__RT_impl_##Name(args, isolate)); \ } \ \ Type Name(int args_length, Address* args_object, Isolate* isolate) { \ DCHECK(isolate->context().is_null() || isolate->context().IsContext()); \ CLOBBER_DOUBLE_REGISTERS(); \ if (V8_UNLIKELY(TracingFlags::is_runtime_stats_enabled())) { \ return Stats_##Name(args_length, args_object, isolate); \ } \ RuntimeArguments args(args_length, args_object); \ return Convert(__RT_impl_##Name(args, isolate)); \ } \ \ static InternalType __RT_impl_##Name(RuntimeArguments args, Isolate* isolate) #define CONVERT_OBJECT(x) (x).ptr() #define CONVERT_OBJECTPAIR(x) (x) #define RUNTIME_FUNCTION(Name) \ RUNTIME_FUNCTION_RETURNS_TYPE(Address, Object, CONVERT_OBJECT, Name) #define RUNTIME_FUNCTION_RETURN_PAIR(Name) \ RUNTIME_FUNCTION_RETURNS_TYPE(ObjectPair, ObjectPair, CONVERT_OBJECTPAIR, \ Name) } // namespace internal } // namespace v8 #endif // V8_EXECUTION_ARGUMENTS_H_