src/runtime/runtime-utils.h

// Copyright 2014 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_RUNTIME_RUNTIME_UTILS_H_
#define V8_RUNTIME_RUNTIME_UTILS_H_

#include "src/base/logging.h"
#include "src/globals.h"
#include "src/runtime/runtime.h"

namespace v8 {
namespace internal {

// Cast the given object to a value of the specified type and store
// it in a variable with the given name.  If the object is not of the
// expected type we crash safely.
#define CONVERT_ARG_CHECKED(Type, name, index) \
  CHECK(args[index]->Is##Type());              \
  Type* name = Type::cast(args[index]);

#define CONVERT_ARG_HANDLE_CHECKED(Type, name, index) \
  CHECK(args[index]->Is##Type());                     \
  Handle<Type> name = args.at<Type>(index);

#define CONVERT_NUMBER_ARG_HANDLE_CHECKED(name, index) \
  CHECK(args[index]->IsNumber());                      \
  Handle<Object> name = args.at(index);

// Cast the given object to a boolean and store it in a variable with
// the given name.  If the object is not a boolean we crash safely.
#define CONVERT_BOOLEAN_ARG_CHECKED(name, index) \
  CHECK(args[index]->IsBoolean());               \
  bool name = args[index]->IsTrue(isolate);

// Cast the given argument to a Smi and store its value in an int variable
// with the given name.  If the argument is not a Smi we crash safely.
#define CONVERT_SMI_ARG_CHECKED(name, index) \
  CHECK(args[index]->IsSmi());               \
  int name = args.smi_at(index);

// Cast the given argument to a double and store it in a variable with
// the given name.  If the argument is not a number (as opposed to
// the number not-a-number) we crash safely.
#define CONVERT_DOUBLE_ARG_CHECKED(name, index) \
  CHECK(args[index]->IsNumber());               \
  double name = args.number_at(index);

// Cast the given argument to a size_t and store its value in a variable with
// the given name.  If the argument is not a size_t we crash safely.
#define CONVERT_SIZE_ARG_CHECKED(name, index)    \
  CHECK(args[index]->IsNumber());                \
  Handle<Object> name##_object = args.at(index); \
  size_t name = 0;                               \
  CHECK(TryNumberToSize(*name##_object, &name));

// Call the specified converter on the object *comand store the result in
// a variable of the specified type with the given name.  If the
// object is not a Number we crash safely.
#define CONVERT_NUMBER_CHECKED(type, name, Type, obj) \
  CHECK(obj->IsNumber());                             \
  type name = NumberTo##Type(obj);

// Cast the given argument to PropertyDetails and store its value in a
// variable with the given name.  If the argument is not a Smi we crash safely.
#define CONVERT_PROPERTY_DETAILS_CHECKED(name, index) \
  CHECK(args[index]->IsSmi());                        \
  PropertyDetails name = PropertyDetails(Smi::cast(args[index]));

// Assert that the given argument has a valid value for a LanguageMode
// and store it in a LanguageMode variable with the given name.
#define CONVERT_LANGUAGE_MODE_ARG_CHECKED(name, index) \
  CHECK(args[index]->IsNumber());                      \
  int32_t __tmp_##name = 0;                            \
  CHECK(args[index]->ToInt32(&__tmp_##name));          \
  CHECK(is_valid_language_mode(__tmp_##name));         \
  LanguageMode name = static_cast<LanguageMode>(__tmp_##name);

// Assert that the given argument is a number within the Int32 range
// and convert it to int32_t.  If the argument is not an Int32 we crash safely.
#define CONVERT_INT32_ARG_CHECKED(name, index) \
  CHECK(args[index]->IsNumber());              \
  int32_t name = 0;                            \
  CHECK(args[index]->ToInt32(&name));

// Assert that the given argument is a number within the Uint32 range
// and convert it to uint32_t.  If the argument is not an Uint32 call
// IllegalOperation and return.
#define CONVERT_UINT32_ARG_CHECKED(name, index) \
  CHECK(args[index]->IsNumber());               \
  uint32_t name = 0;                            \
  CHECK(args[index]->ToUint32(&name));

// Cast the given argument to PropertyAttributes and store its value in a
// variable with the given name.  If the argument is not a Smi or the
// enum value is out of range, we crash safely.
#define CONVERT_PROPERTY_ATTRIBUTES_CHECKED(name, index)                    \
  CHECK(args[index]->IsSmi());                                              \
  CHECK_EQ(args.smi_at(index) & ~(READ_ONLY | DONT_ENUM | DONT_DELETE), 0); \
  PropertyAttributes name = static_cast<PropertyAttributes>(args.smi_at(index));

// A mechanism to return a pair of Object pointers in registers (if possible).
// How this is achieved is calling convention-dependent.
// All currently supported x86 compiles uses calling conventions that are cdecl
// variants where a 64-bit value is returned in two 32-bit registers
// (edx:eax on ia32, r1:r0 on ARM).
// In AMD-64 calling convention a struct of two pointers is returned in rdx:rax.
// In Win64 calling convention, a struct of two pointers is returned in memory,
// allocated by the caller, and passed as a pointer in a hidden first parameter.
#ifdef V8_HOST_ARCH_64_BIT
struct ObjectPair {
  Object* x;
  Object* y;
};


static inline ObjectPair MakePair(Object* x, Object* y) {
  ObjectPair result = {x, y};
  // Pointers x and y returned in rax and rdx, in AMD-x64-abi.
  // In Win64 they are assigned to a hidden first argument.
  return result;
}
#elif V8_TARGET_ARCH_X64 && V8_TARGET_ARCH_32_BIT
// For x32 a 128-bit struct return is done as rax and rdx from the ObjectPair
// are used in generated code. An alternative is using uint64_t and modifying
// generated code.
struct ObjectPair {
  Object* x;
  uint32_t x_upper;
  Object* y;
  uint32_t y_upper;
};


static inline ObjectPair MakePair(Object* x, Object* y) {
  ObjectPair result = {x, 0, y, 0};
  // Pointers x and y returned in rax and rdx, in x32-abi.
  return result;
}
#else
typedef uint64_t ObjectPair;
static inline ObjectPair MakePair(Object* x, Object* y) {
#if defined(V8_TARGET_LITTLE_ENDIAN)
  return reinterpret_cast<uint32_t>(x) |
         (reinterpret_cast<ObjectPair>(y) << 32);
#elif defined(V8_TARGET_BIG_ENDIAN)
  return reinterpret_cast<uint32_t>(y) |
         (reinterpret_cast<ObjectPair>(x) << 32);
#else
#error Unknown endianness
#endif
}
#endif

}  // namespace internal
}  // namespace v8

#endif  // V8_RUNTIME_RUNTIME_UTILS_H_