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// 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-inl.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> 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_; }
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 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, &RuntimeCallStats::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(TRACE_EVENT_RUNTIME_CALL_STATS_TRACING_ENABLED() || \
FLAG_runtime_call_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)
#define RUNTIME_FUNCTION_RETURN_TRIPLE(Name) \
RUNTIME_FUNCTION_RETURNS_TYPE(ObjectTriple, Name)
} // namespace internal
} // namespace v8
#endif // V8_ARGUMENTS_H_