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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_EXECUTION_ARGUMENTS_H_
#define V8_EXECUTION_ARGUMENTS_H_
#include "src/execution/clobber-registers.h"
#include "src/handles/handles.h"
#include "src/logging/runtime-call-stats-scope.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:
// Scope to temporarily change the value of an argument.
class ChangeValueScope {
public:
inline ChangeValueScope(Isolate* isolate, Arguments* args, int index,
Tagged<Object> value);
~ChangeValueScope() { *location_ = (*old_value_).ptr(); }
private:
Address* location_;
Handle<Object> old_value_;
};
Arguments(int length, Address* arguments)
: length_(length), arguments_(arguments) {
DCHECK_GE(length_, 0);
}
V8_INLINE Tagged<Object> operator[](int index) const {
return Tagged<Object>(*address_of_arg_at(index));
}
template <class S = Object>
V8_INLINE Handle<S> at(int index) const;
V8_INLINE FullObjectSlot slot_from_address_at(int index, int offset) const;
V8_INLINE int smi_value_at(int index) const;
V8_INLINE uint32_t positive_smi_value_at(int index) const;
V8_INLINE int tagged_index_value_at(int index) const;
V8_INLINE double number_value_at(int index) const;
V8_INLINE Handle<Object> atOrUndefined(Isolate* isolate, int index) const;
V8_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;
if (arguments_type == ArgumentsType::kJS) {
offset = (length_ - index - 1) * kSystemPointerSize;
}
return reinterpret_cast<Address*>(reinterpret_cast<Address>(arguments_) -
offset);
}
// Get the total number of arguments including the receiver.
V8_INLINE int length() const { return static_cast<int>(length_); }
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);
}
template <ArgumentsType T>
FullObjectSlot Arguments<T>::slot_from_address_at(int index, int offset) const {
Address* location = *reinterpret_cast<Address**>(address_of_arg_at(index));
return FullObjectSlot(location + offset);
}
#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.
#ifdef V8_RUNTIME_CALL_STATS
#define RUNTIME_ENTRY_WITH_RCS(Type, InternalType, Convert, Name) \
V8_NOINLINE static Type Stats_##Name(int args_length, Address* args_object, \
Isolate* isolate) { \
RCS_SCOPE(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)); \
}
#define TEST_AND_CALL_RCS(Name) \
if (V8_UNLIKELY(TracingFlags::is_runtime_stats_enabled())) { \
return Stats_##Name(args_length, args_object, isolate); \
}
#else // V8_RUNTIME_CALL_STATS
#define RUNTIME_ENTRY_WITH_RCS(Type, InternalType, Convert, Name)
#define TEST_AND_CALL_RCS(Name)
#endif // V8_RUNTIME_CALL_STATS
#define RUNTIME_FUNCTION_RETURNS_TYPE(Type, InternalType, Convert, Name) \
static V8_INLINE InternalType __RT_impl_##Name(RuntimeArguments args, \
Isolate* isolate); \
RUNTIME_ENTRY_WITH_RCS(Type, InternalType, Convert, Name) \
Type Name(int args_length, Address* args_object, Isolate* isolate) { \
DCHECK(isolate->context().is_null() || IsContext(isolate->context())); \
CLOBBER_DOUBLE_REGISTERS(); \
TEST_AND_CALL_RCS(Name) \
RuntimeArguments args(args_length, args_object); \
return Convert(__RT_impl_##Name(args, isolate)); \
} \
\
static InternalType __RT_impl_##Name(RuntimeArguments args, Isolate* isolate)
#ifdef DEBUG
#define BUILTIN_CONVERT_RESULT(x) (isolate->VerifyBuiltinsResult(x)).ptr()
#define BUILTIN_CONVERT_RESULT_PAIR(x) isolate->VerifyBuiltinsResult(x)
#else // DEBUG
#define BUILTIN_CONVERT_RESULT(x) (x).ptr()
#define BUILTIN_CONVERT_RESULT_PAIR(x) (x)
#endif // DEBUG
#define RUNTIME_FUNCTION(Name) \
RUNTIME_FUNCTION_RETURNS_TYPE(Address, Tagged<Object>, \
BUILTIN_CONVERT_RESULT, Name)
#define RUNTIME_FUNCTION_RETURN_PAIR(Name) \
RUNTIME_FUNCTION_RETURNS_TYPE(ObjectPair, ObjectPair, \
BUILTIN_CONVERT_RESULT_PAIR, Name)
} // namespace internal
} // namespace v8
#endif // V8_EXECUTION_ARGUMENTS_H_
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