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c3317f9be6
gecko/js/public/Value.h
Jason Orendorff c3317f9be6 Bug 645416, part 1 - Add an enum for symbols to JSValueType. r=nbp. 
JSVAL_TYPE_SYMBOL is inserted between STRING and NULL, rather than added at the
end, in order to preserve all the inequality relations on JSValueTypes used
throughout Value.h. (Search the header for the operators < > <= >=.)

Otherwise, this pretty much just works. Some details of Ion snapshot layout
had to change to accommodate 4-bit types.

--HG--
extra : rebase_source : e3141e6a9ee32ef563dab43a4942a9e67d234865
2014-06-23 10:55:51 -05:00

1921 lines
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/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 4 -*-
* vim: set ts=8 sts=4 et sw=4 tw=99:
* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
* file, You can obtain one at http://mozilla.org/MPL/2.0/. */
/* JS::Value implementation. */
#ifndef js_Value_h
#define js_Value_h
#include "mozilla/Attributes.h"
#include "mozilla/FloatingPoint.h"
#include "mozilla/Likely.h"
#include <limits> /* for std::numeric_limits */
#include "js-config.h"
#include "jstypes.h"
#include "js/Anchor.h"
#include "js/GCAPI.h"
#include "js/RootingAPI.h"
#include "js/Utility.h"
namespace JS { class Value; }
/* JS::Value can store a full int32_t. */
#define JSVAL_INT_BITS 32
#define JSVAL_INT_MIN ((int32_t)0x80000000)
#define JSVAL_INT_MAX ((int32_t)0x7fffffff)
/*
* Try to get jsvals 64-bit aligned. We could almost assert that all values are
* aligned, but MSVC and GCC occasionally break alignment.
*/
#if defined(__GNUC__) || defined(__xlc__) || defined(__xlC__)
# define JSVAL_ALIGNMENT __attribute__((aligned (8)))
#elif defined(_MSC_VER)
/*
* Structs can be aligned with MSVC, but not if they are used as parameters,
* so we just don't try to align.
*/
# define JSVAL_ALIGNMENT
#elif defined(__SUNPRO_C) || defined(__SUNPRO_CC)
# define JSVAL_ALIGNMENT
#elif defined(__HP_cc) || defined(__HP_aCC)
# define JSVAL_ALIGNMENT
#endif
#if defined(JS_PUNBOX64)
# define JSVAL_TAG_SHIFT 47
#endif
/*
* We try to use enums so that printing a jsval_layout in the debugger shows
* nice symbolic type tags, however we can only do this when we can force the
* underlying type of the enum to be the desired size.
*/
#if !defined(__SUNPRO_CC) && !defined(__xlC__)
#if defined(_MSC_VER)
# define JS_ENUM_HEADER(id, type) enum id : type
# define JS_ENUM_FOOTER(id)
#else
# define JS_ENUM_HEADER(id, type) enum id
# define JS_ENUM_FOOTER(id) __attribute__((packed))
#endif
/* Remember to propagate changes to the C defines below. */
JS_ENUM_HEADER(JSValueType, uint8_t)
{
JSVAL_TYPE_DOUBLE = 0x00,
JSVAL_TYPE_INT32 = 0x01,
JSVAL_TYPE_UNDEFINED = 0x02,
JSVAL_TYPE_BOOLEAN = 0x03,
JSVAL_TYPE_MAGIC = 0x04,
JSVAL_TYPE_STRING = 0x05,
JSVAL_TYPE_SYMBOL = 0x06,
JSVAL_TYPE_NULL = 0x07,
JSVAL_TYPE_OBJECT = 0x08,
/* These never appear in a jsval; they are only provided as an out-of-band value. */
JSVAL_TYPE_UNKNOWN = 0x20,
JSVAL_TYPE_MISSING = 0x21
} JS_ENUM_FOOTER(JSValueType);
JS_STATIC_ASSERT(sizeof(JSValueType) == 1);
#if defined(JS_NUNBOX32)
/* Remember to propagate changes to the C defines below. */
JS_ENUM_HEADER(JSValueTag, uint32_t)
{
JSVAL_TAG_CLEAR = 0xFFFFFF80,
JSVAL_TAG_INT32 = JSVAL_TAG_CLEAR | JSVAL_TYPE_INT32,
JSVAL_TAG_UNDEFINED = JSVAL_TAG_CLEAR | JSVAL_TYPE_UNDEFINED,
JSVAL_TAG_STRING = JSVAL_TAG_CLEAR | JSVAL_TYPE_STRING,
JSVAL_TAG_BOOLEAN = JSVAL_TAG_CLEAR | JSVAL_TYPE_BOOLEAN,
JSVAL_TAG_MAGIC = JSVAL_TAG_CLEAR | JSVAL_TYPE_MAGIC,
JSVAL_TAG_NULL = JSVAL_TAG_CLEAR | JSVAL_TYPE_NULL,
JSVAL_TAG_OBJECT = JSVAL_TAG_CLEAR | JSVAL_TYPE_OBJECT
} JS_ENUM_FOOTER(JSValueTag);
JS_STATIC_ASSERT(sizeof(JSValueTag) == 4);
#elif defined(JS_PUNBOX64)
/* Remember to propagate changes to the C defines below. */
JS_ENUM_HEADER(JSValueTag, uint32_t)
{
JSVAL_TAG_MAX_DOUBLE = 0x1FFF0,
JSVAL_TAG_INT32 = JSVAL_TAG_MAX_DOUBLE | JSVAL_TYPE_INT32,
JSVAL_TAG_UNDEFINED = JSVAL_TAG_MAX_DOUBLE | JSVAL_TYPE_UNDEFINED,
JSVAL_TAG_STRING = JSVAL_TAG_MAX_DOUBLE | JSVAL_TYPE_STRING,
JSVAL_TAG_BOOLEAN = JSVAL_TAG_MAX_DOUBLE | JSVAL_TYPE_BOOLEAN,
JSVAL_TAG_MAGIC = JSVAL_TAG_MAX_DOUBLE | JSVAL_TYPE_MAGIC,
JSVAL_TAG_NULL = JSVAL_TAG_MAX_DOUBLE | JSVAL_TYPE_NULL,
JSVAL_TAG_OBJECT = JSVAL_TAG_MAX_DOUBLE | JSVAL_TYPE_OBJECT
} JS_ENUM_FOOTER(JSValueTag);
JS_STATIC_ASSERT(sizeof(JSValueTag) == sizeof(uint32_t));
JS_ENUM_HEADER(JSValueShiftedTag, uint64_t)
{
JSVAL_SHIFTED_TAG_MAX_DOUBLE = ((((uint64_t)JSVAL_TAG_MAX_DOUBLE) << JSVAL_TAG_SHIFT) | 0xFFFFFFFF),
JSVAL_SHIFTED_TAG_INT32 = (((uint64_t)JSVAL_TAG_INT32) << JSVAL_TAG_SHIFT),
JSVAL_SHIFTED_TAG_UNDEFINED = (((uint64_t)JSVAL_TAG_UNDEFINED) << JSVAL_TAG_SHIFT),
JSVAL_SHIFTED_TAG_STRING = (((uint64_t)JSVAL_TAG_STRING) << JSVAL_TAG_SHIFT),
JSVAL_SHIFTED_TAG_BOOLEAN = (((uint64_t)JSVAL_TAG_BOOLEAN) << JSVAL_TAG_SHIFT),
JSVAL_SHIFTED_TAG_MAGIC = (((uint64_t)JSVAL_TAG_MAGIC) << JSVAL_TAG_SHIFT),
JSVAL_SHIFTED_TAG_NULL = (((uint64_t)JSVAL_TAG_NULL) << JSVAL_TAG_SHIFT),
JSVAL_SHIFTED_TAG_OBJECT = (((uint64_t)JSVAL_TAG_OBJECT) << JSVAL_TAG_SHIFT)
} JS_ENUM_FOOTER(JSValueShiftedTag);
JS_STATIC_ASSERT(sizeof(JSValueShiftedTag) == sizeof(uint64_t));
#endif
#else /* !defined(__SUNPRO_CC) && !defined(__xlC__) */
typedef uint8_t JSValueType;
#define JSVAL_TYPE_DOUBLE ((uint8_t)0x00)
#define JSVAL_TYPE_INT32 ((uint8_t)0x01)
#define JSVAL_TYPE_UNDEFINED ((uint8_t)0x02)
#define JSVAL_TYPE_BOOLEAN ((uint8_t)0x03)
#define JSVAL_TYPE_MAGIC ((uint8_t)0x04)
#define JSVAL_TYPE_STRING ((uint8_t)0x05)
#define JSVAL_TYPE_NULL ((uint8_t)0x06)
#define JSVAL_TYPE_OBJECT ((uint8_t)0x07)
#define JSVAL_TYPE_UNKNOWN ((uint8_t)0x20)
#if defined(JS_NUNBOX32)
typedef uint32_t JSValueTag;
#define JSVAL_TAG_CLEAR ((uint32_t)(0xFFFFFF80))
#define JSVAL_TAG_INT32 ((uint32_t)(JSVAL_TAG_CLEAR | JSVAL_TYPE_INT32))
#define JSVAL_TAG_UNDEFINED ((uint32_t)(JSVAL_TAG_CLEAR | JSVAL_TYPE_UNDEFINED))
#define JSVAL_TAG_STRING ((uint32_t)(JSVAL_TAG_CLEAR | JSVAL_TYPE_STRING))
#define JSVAL_TAG_BOOLEAN ((uint32_t)(JSVAL_TAG_CLEAR | JSVAL_TYPE_BOOLEAN))
#define JSVAL_TAG_MAGIC ((uint32_t)(JSVAL_TAG_CLEAR | JSVAL_TYPE_MAGIC))
#define JSVAL_TAG_NULL ((uint32_t)(JSVAL_TAG_CLEAR | JSVAL_TYPE_NULL))
#define JSVAL_TAG_OBJECT ((uint32_t)(JSVAL_TAG_CLEAR | JSVAL_TYPE_OBJECT))
#elif defined(JS_PUNBOX64)
typedef uint32_t JSValueTag;
#define JSVAL_TAG_MAX_DOUBLE ((uint32_t)(0x1FFF0))
#define JSVAL_TAG_INT32 (uint32_t)(JSVAL_TAG_MAX_DOUBLE | JSVAL_TYPE_INT32)
#define JSVAL_TAG_UNDEFINED (uint32_t)(JSVAL_TAG_MAX_DOUBLE | JSVAL_TYPE_UNDEFINED)
#define JSVAL_TAG_STRING (uint32_t)(JSVAL_TAG_MAX_DOUBLE | JSVAL_TYPE_STRING)
#define JSVAL_TAG_BOOLEAN (uint32_t)(JSVAL_TAG_MAX_DOUBLE | JSVAL_TYPE_BOOLEAN)
#define JSVAL_TAG_MAGIC (uint32_t)(JSVAL_TAG_MAX_DOUBLE | JSVAL_TYPE_MAGIC)
#define JSVAL_TAG_NULL (uint32_t)(JSVAL_TAG_MAX_DOUBLE | JSVAL_TYPE_NULL)
#define JSVAL_TAG_OBJECT (uint32_t)(JSVAL_TAG_MAX_DOUBLE | JSVAL_TYPE_OBJECT)
typedef uint64_t JSValueShiftedTag;
#define JSVAL_SHIFTED_TAG_MAX_DOUBLE ((((uint64_t)JSVAL_TAG_MAX_DOUBLE) << JSVAL_TAG_SHIFT) | 0xFFFFFFFF)
#define JSVAL_SHIFTED_TAG_INT32 (((uint64_t)JSVAL_TAG_INT32) << JSVAL_TAG_SHIFT)
#define JSVAL_SHIFTED_TAG_UNDEFINED (((uint64_t)JSVAL_TAG_UNDEFINED) << JSVAL_TAG_SHIFT)
#define JSVAL_SHIFTED_TAG_STRING (((uint64_t)JSVAL_TAG_STRING) << JSVAL_TAG_SHIFT)
#define JSVAL_SHIFTED_TAG_BOOLEAN (((uint64_t)JSVAL_TAG_BOOLEAN) << JSVAL_TAG_SHIFT)
#define JSVAL_SHIFTED_TAG_MAGIC (((uint64_t)JSVAL_TAG_MAGIC) << JSVAL_TAG_SHIFT)
#define JSVAL_SHIFTED_TAG_NULL (((uint64_t)JSVAL_TAG_NULL) << JSVAL_TAG_SHIFT)
#define JSVAL_SHIFTED_TAG_OBJECT (((uint64_t)JSVAL_TAG_OBJECT) << JSVAL_TAG_SHIFT)
#endif /* JS_PUNBOX64 */
#endif /* !defined(__SUNPRO_CC) && !defined(__xlC__) */
#define JSVAL_LOWER_INCL_TYPE_OF_OBJ_OR_NULL_SET JSVAL_TYPE_NULL
#define JSVAL_UPPER_EXCL_TYPE_OF_PRIMITIVE_SET JSVAL_TYPE_OBJECT
#define JSVAL_UPPER_INCL_TYPE_OF_NUMBER_SET JSVAL_TYPE_INT32
#define JSVAL_LOWER_INCL_TYPE_OF_PTR_PAYLOAD_SET JSVAL_TYPE_MAGIC
#if defined(JS_NUNBOX32)
#define JSVAL_TYPE_TO_TAG(type) ((JSValueTag)(JSVAL_TAG_CLEAR | (type)))
#define JSVAL_LOWER_INCL_TAG_OF_OBJ_OR_NULL_SET JSVAL_TAG_NULL
#define JSVAL_UPPER_EXCL_TAG_OF_PRIMITIVE_SET JSVAL_TAG_OBJECT
#define JSVAL_UPPER_INCL_TAG_OF_NUMBER_SET JSVAL_TAG_INT32
#define JSVAL_LOWER_INCL_TAG_OF_GCTHING_SET JSVAL_TAG_STRING
#elif defined(JS_PUNBOX64)
#define JSVAL_PAYLOAD_MASK 0x00007FFFFFFFFFFFLL
#define JSVAL_TAG_MASK 0xFFFF800000000000LL
#define JSVAL_TYPE_TO_TAG(type) ((JSValueTag)(JSVAL_TAG_MAX_DOUBLE | (type)))
#define JSVAL_TYPE_TO_SHIFTED_TAG(type) (((uint64_t)JSVAL_TYPE_TO_TAG(type)) << JSVAL_TAG_SHIFT)
#define JSVAL_LOWER_INCL_TAG_OF_OBJ_OR_NULL_SET JSVAL_TAG_NULL
#define JSVAL_UPPER_EXCL_TAG_OF_PRIMITIVE_SET JSVAL_TAG_OBJECT
#define JSVAL_UPPER_INCL_TAG_OF_NUMBER_SET JSVAL_TAG_INT32
#define JSVAL_LOWER_INCL_TAG_OF_GCTHING_SET JSVAL_TAG_STRING
#define JSVAL_LOWER_INCL_SHIFTED_TAG_OF_OBJ_OR_NULL_SET JSVAL_SHIFTED_TAG_NULL
#define JSVAL_UPPER_EXCL_SHIFTED_TAG_OF_PRIMITIVE_SET JSVAL_SHIFTED_TAG_OBJECT
#define JSVAL_UPPER_EXCL_SHIFTED_TAG_OF_NUMBER_SET JSVAL_SHIFTED_TAG_UNDEFINED
#define JSVAL_LOWER_INCL_SHIFTED_TAG_OF_GCTHING_SET JSVAL_SHIFTED_TAG_STRING
#endif /* JS_PUNBOX64 */
typedef enum JSWhyMagic
{
JS_ELEMENTS_HOLE, /* a hole in a native object's elements */
JS_NATIVE_ENUMERATE, /* indicates that a custom enumerate hook forwarded
* to JS_EnumerateState, which really means the object can be
* enumerated like a native object. */
JS_NO_ITER_VALUE, /* there is not a pending iterator value */
JS_GENERATOR_CLOSING, /* exception value thrown when closing a generator */
JS_NO_CONSTANT, /* compiler sentinel value */
JS_THIS_POISON, /* used in debug builds to catch tracing errors */
JS_ARG_POISON, /* used in debug builds to catch tracing errors */
JS_SERIALIZE_NO_NODE, /* an empty subnode in the AST serializer */
JS_LAZY_ARGUMENTS, /* lazy arguments value on the stack */
JS_OPTIMIZED_ARGUMENTS, /* optimized-away 'arguments' value */
JS_IS_CONSTRUCTING, /* magic value passed to natives to indicate construction */
JS_OVERWRITTEN_CALLEE, /* arguments.callee has been overwritten */
JS_BLOCK_NEEDS_CLONE, /* value of static block object slot */
JS_HASH_KEY_EMPTY, /* see class js::HashableValue */
JS_ION_ERROR, /* error while running Ion code */
JS_ION_BAILOUT, /* missing recover instruction result */
JS_OPTIMIZED_OUT, /* optimized out slot */
JS_GENERIC_MAGIC /* for local use */
} JSWhyMagic;
#if defined(IS_LITTLE_ENDIAN)
# if defined(JS_NUNBOX32)
typedef union jsval_layout
{
uint64_t asBits;
struct {
union {
int32_t i32;
uint32_t u32;
uint32_t boo; // Don't use |bool| -- it must be four bytes.
JSString *str;
JSObject *obj;
js::gc::Cell *cell;
void *ptr;
JSWhyMagic why;
size_t word;
uintptr_t uintptr;
} payload;
JSValueTag tag;
} s;
double asDouble;
void *asPtr;
} JSVAL_ALIGNMENT jsval_layout;
# elif defined(JS_PUNBOX64)
typedef union jsval_layout
{
uint64_t asBits;
#if !defined(_WIN64)
/* MSVC does not pack these correctly :-( */
struct {
uint64_t payload47 : 47;
JSValueTag tag : 17;
} debugView;
#endif
struct {
union {
int32_t i32;
uint32_t u32;
JSWhyMagic why;
} payload;
} s;
double asDouble;
void *asPtr;
size_t asWord;
uintptr_t asUIntPtr;
} JSVAL_ALIGNMENT jsval_layout;
# endif /* JS_PUNBOX64 */
#else /* defined(IS_LITTLE_ENDIAN) */
# if defined(JS_NUNBOX32)
typedef union jsval_layout
{
uint64_t asBits;
struct {
JSValueTag tag;
union {
int32_t i32;
uint32_t u32;
uint32_t boo; // Don't use |bool| -- it must be four bytes.
JSString *str;
JSObject *obj;
js::gc::Cell *cell;
void *ptr;
JSWhyMagic why;
size_t word;
uintptr_t uintptr;
} payload;
} s;
double asDouble;
void *asPtr;
} JSVAL_ALIGNMENT jsval_layout;
# elif defined(JS_PUNBOX64)
typedef union jsval_layout
{
uint64_t asBits;
struct {
JSValueTag tag : 17;
uint64_t payload47 : 47;
} debugView;
struct {
uint32_t padding;
union {
int32_t i32;
uint32_t u32;
JSWhyMagic why;
} payload;
} s;
double asDouble;
void *asPtr;
size_t asWord;
uintptr_t asUIntPtr;
} JSVAL_ALIGNMENT jsval_layout;
# endif /* JS_PUNBOX64 */
#endif /* defined(IS_LITTLE_ENDIAN) */
JS_STATIC_ASSERT(sizeof(jsval_layout) == 8);
/*
* For codesize purposes on some platforms, it's important that the
* compiler know that JS::Values constructed from constant values can be
* folded to constant bit patterns at compile time, rather than
* constructed at runtime. Doing this requires a fair amount of C++11
* features, which are not supported on all of our compilers. Set up
* some defines and helper macros in an attempt to confine the ugliness
* here, rather than scattering it all about the file. The important
* features are:
*
* - constexpr;
* - defaulted functions;
* - C99-style designated initializers.
*/
#if defined(__clang__)
# if __has_feature(cxx_constexpr) && __has_feature(cxx_defaulted_functions)
# define JS_VALUE_IS_CONSTEXPR
# endif
#elif defined(__GNUC__)
/*
* We need 4.5 for defaulted functions, 4.6 for constexpr, 4.7 because 4.6
* doesn't understand |(X) { .field = ... }| syntax, and 4.7.3 because
* versions prior to that have bugs in the C++ front-end that cause crashes.
*/
# if MOZ_GCC_VERSION_AT_LEAST(4, 7, 3)
# define JS_VALUE_IS_CONSTEXPR
# endif
#endif
#if defined(JS_VALUE_IS_CONSTEXPR)
# define JS_RETURN_LAYOUT_FROM_BITS(BITS) \
return (jsval_layout) { .asBits = (BITS) }
# define JS_VALUE_CONSTEXPR MOZ_CONSTEXPR
# define JS_VALUE_CONSTEXPR_VAR MOZ_CONSTEXPR_VAR
#else
# define JS_RETURN_LAYOUT_FROM_BITS(BITS) \
jsval_layout l; \
l.asBits = (BITS); \
return l;
# define JS_VALUE_CONSTEXPR
# define JS_VALUE_CONSTEXPR_VAR const
#endif
#if defined(JS_NUNBOX32)
/*
* N.B. GCC, in some but not all cases, chooses to emit signed comparison of
* JSValueTag even though its underlying type has been forced to be uint32_t.
* Thus, all comparisons should explicitly cast operands to uint32_t.
*/
static inline JS_VALUE_CONSTEXPR jsval_layout
BUILD_JSVAL(JSValueTag tag, uint32_t payload)
{
JS_RETURN_LAYOUT_FROM_BITS((((uint64_t)(uint32_t)tag) << 32) | payload);
}
static inline bool
JSVAL_IS_DOUBLE_IMPL(jsval_layout l)
{
return (uint32_t)l.s.tag <= (uint32_t)JSVAL_TAG_CLEAR;
}
static inline jsval_layout
DOUBLE_TO_JSVAL_IMPL(double d)
{
jsval_layout l;
l.asDouble = d;
MOZ_ASSERT(JSVAL_IS_DOUBLE_IMPL(l));
return l;
}
static inline bool
JSVAL_IS_INT32_IMPL(jsval_layout l)
{
return l.s.tag == JSVAL_TAG_INT32;
}
static inline int32_t
JSVAL_TO_INT32_IMPL(jsval_layout l)
{
return l.s.payload.i32;
}
static inline JS_VALUE_CONSTEXPR jsval_layout
INT32_TO_JSVAL_IMPL(int32_t i)
{
#if defined(JS_VALUE_IS_CONSTEXPR)
return BUILD_JSVAL(JSVAL_TAG_INT32, i);
#else
jsval_layout l;
l.s.tag = JSVAL_TAG_INT32;
l.s.payload.i32 = i;
return l;
#endif
}
static inline bool
JSVAL_IS_NUMBER_IMPL(jsval_layout l)
{
JSValueTag tag = l.s.tag;
MOZ_ASSERT(tag != JSVAL_TAG_CLEAR);
return (uint32_t)tag <= (uint32_t)JSVAL_UPPER_INCL_TAG_OF_NUMBER_SET;
}
static inline bool
JSVAL_IS_UNDEFINED_IMPL(jsval_layout l)
{
return l.s.tag == JSVAL_TAG_UNDEFINED;
}
static inline bool
JSVAL_IS_STRING_IMPL(jsval_layout l)
{
return l.s.tag == JSVAL_TAG_STRING;
}
static inline jsval_layout
STRING_TO_JSVAL_IMPL(JSString *str)
{
jsval_layout l;
MOZ_ASSERT(uintptr_t(str) > 0x1000);
l.s.tag = JSVAL_TAG_STRING;
l.s.payload.str = str;
return l;
}
static inline JSString *
JSVAL_TO_STRING_IMPL(jsval_layout l)
{
return l.s.payload.str;
}
static inline bool
JSVAL_IS_BOOLEAN_IMPL(jsval_layout l)
{
return l.s.tag == JSVAL_TAG_BOOLEAN;
}
static inline bool
JSVAL_TO_BOOLEAN_IMPL(jsval_layout l)
{
return l.s.payload.boo;
}
static inline jsval_layout
BOOLEAN_TO_JSVAL_IMPL(bool b)
{
jsval_layout l;
l.s.tag = JSVAL_TAG_BOOLEAN;
l.s.payload.boo = b;
return l;
}
static inline bool
JSVAL_IS_MAGIC_IMPL(jsval_layout l)
{
return l.s.tag == JSVAL_TAG_MAGIC;
}
static inline bool
JSVAL_IS_OBJECT_IMPL(jsval_layout l)
{
return l.s.tag == JSVAL_TAG_OBJECT;
}
static inline bool
JSVAL_IS_PRIMITIVE_IMPL(jsval_layout l)
{
return (uint32_t)l.s.tag < (uint32_t)JSVAL_UPPER_EXCL_TAG_OF_PRIMITIVE_SET;
}
static inline bool
JSVAL_IS_OBJECT_OR_NULL_IMPL(jsval_layout l)
{
MOZ_ASSERT((uint32_t)l.s.tag <= (uint32_t)JSVAL_TAG_OBJECT);
return (uint32_t)l.s.tag >= (uint32_t)JSVAL_LOWER_INCL_TAG_OF_OBJ_OR_NULL_SET;
}
static inline JSObject *
JSVAL_TO_OBJECT_IMPL(jsval_layout l)
{
return l.s.payload.obj;
}
static inline jsval_layout
OBJECT_TO_JSVAL_IMPL(JSObject *obj)
{
jsval_layout l;
MOZ_ASSERT(uintptr_t(obj) > 0x1000 || uintptr_t(obj) == 0x42);
l.s.tag = JSVAL_TAG_OBJECT;
l.s.payload.obj = obj;
return l;
}
static inline bool
JSVAL_IS_NULL_IMPL(jsval_layout l)
{
return l.s.tag == JSVAL_TAG_NULL;
}
static inline jsval_layout
PRIVATE_PTR_TO_JSVAL_IMPL(void *ptr)
{
jsval_layout l;
MOZ_ASSERT(((uint32_t)ptr & 1) == 0);
l.s.tag = (JSValueTag)0;
l.s.payload.ptr = ptr;
MOZ_ASSERT(JSVAL_IS_DOUBLE_IMPL(l));
return l;
}
static inline void *
JSVAL_TO_PRIVATE_PTR_IMPL(jsval_layout l)
{
return l.s.payload.ptr;
}
static inline bool
JSVAL_IS_GCTHING_IMPL(jsval_layout l)
{
/* gcc sometimes generates signed < without explicit casts. */
return (uint32_t)l.s.tag >= (uint32_t)JSVAL_LOWER_INCL_TAG_OF_GCTHING_SET;
}
static inline js::gc::Cell *
JSVAL_TO_GCTHING_IMPL(jsval_layout l)
{
return l.s.payload.cell;
}
static inline bool
JSVAL_IS_TRACEABLE_IMPL(jsval_layout l)
{
return l.s.tag == JSVAL_TAG_STRING || l.s.tag == JSVAL_TAG_OBJECT;
}
static inline uint32_t
JSVAL_TRACE_KIND_IMPL(jsval_layout l)
{
return (uint32_t)(bool)JSVAL_IS_STRING_IMPL(l);
}
static inline bool
JSVAL_IS_SPECIFIC_INT32_IMPL(jsval_layout l, int32_t i32)
{
return l.s.tag == JSVAL_TAG_INT32 && l.s.payload.i32 == i32;
}
static inline bool
JSVAL_IS_SPECIFIC_BOOLEAN_IMPL(jsval_layout l, bool b)
{
return (l.s.tag == JSVAL_TAG_BOOLEAN) && (l.s.payload.boo == uint32_t(b));
}
static inline jsval_layout
MAGIC_TO_JSVAL_IMPL(JSWhyMagic why)
{
jsval_layout l;
l.s.tag = JSVAL_TAG_MAGIC;
l.s.payload.why = why;
return l;
}
static inline jsval_layout
MAGIC_UINT32_TO_JSVAL_IMPL(uint32_t payload)
{
jsval_layout l;
l.s.tag = JSVAL_TAG_MAGIC;
l.s.payload.u32 = payload;
return l;
}
static inline bool
JSVAL_SAME_TYPE_IMPL(jsval_layout lhs, jsval_layout rhs)
{
JSValueTag ltag = lhs.s.tag, rtag = rhs.s.tag;
return ltag == rtag || (ltag < JSVAL_TAG_CLEAR && rtag < JSVAL_TAG_CLEAR);
}
static inline JSValueType
JSVAL_EXTRACT_NON_DOUBLE_TYPE_IMPL(jsval_layout l)
{
uint32_t type = l.s.tag & 0xF;
MOZ_ASSERT(type > JSVAL_TYPE_DOUBLE);
return (JSValueType)type;
}
#elif defined(JS_PUNBOX64)
static inline JS_VALUE_CONSTEXPR jsval_layout
BUILD_JSVAL(JSValueTag tag, uint64_t payload)
{
JS_RETURN_LAYOUT_FROM_BITS((((uint64_t)(uint32_t)tag) << JSVAL_TAG_SHIFT) | payload);
}
static inline bool
JSVAL_IS_DOUBLE_IMPL(jsval_layout l)
{
return l.asBits <= JSVAL_SHIFTED_TAG_MAX_DOUBLE;
}
static inline jsval_layout
DOUBLE_TO_JSVAL_IMPL(double d)
{
jsval_layout l;
l.asDouble = d;
MOZ_ASSERT(l.asBits <= JSVAL_SHIFTED_TAG_MAX_DOUBLE);
return l;
}
static inline bool
JSVAL_IS_INT32_IMPL(jsval_layout l)
{
return (uint32_t)(l.asBits >> JSVAL_TAG_SHIFT) == JSVAL_TAG_INT32;
}
static inline int32_t
JSVAL_TO_INT32_IMPL(jsval_layout l)
{
return (int32_t)l.asBits;
}
static inline JS_VALUE_CONSTEXPR jsval_layout
INT32_TO_JSVAL_IMPL(int32_t i32)
{
JS_RETURN_LAYOUT_FROM_BITS(((uint64_t)(uint32_t)i32) | JSVAL_SHIFTED_TAG_INT32);
}
static inline bool
JSVAL_IS_NUMBER_IMPL(jsval_layout l)
{
return l.asBits < JSVAL_UPPER_EXCL_SHIFTED_TAG_OF_NUMBER_SET;
}
static inline bool
JSVAL_IS_UNDEFINED_IMPL(jsval_layout l)
{
return l.asBits == JSVAL_SHIFTED_TAG_UNDEFINED;
}
static inline bool
JSVAL_IS_STRING_IMPL(jsval_layout l)
{
return (uint32_t)(l.asBits >> JSVAL_TAG_SHIFT) == JSVAL_TAG_STRING;
}
static inline jsval_layout
STRING_TO_JSVAL_IMPL(JSString *str)
{
jsval_layout l;
uint64_t strBits = (uint64_t)str;
MOZ_ASSERT(uintptr_t(str) > 0x1000);
MOZ_ASSERT((strBits >> JSVAL_TAG_SHIFT) == 0);
l.asBits = strBits | JSVAL_SHIFTED_TAG_STRING;
return l;
}
static inline JSString *
JSVAL_TO_STRING_IMPL(jsval_layout l)
{
return (JSString *)(l.asBits & JSVAL_PAYLOAD_MASK);
}
static inline bool
JSVAL_IS_BOOLEAN_IMPL(jsval_layout l)
{
return (uint32_t)(l.asBits >> JSVAL_TAG_SHIFT) == JSVAL_TAG_BOOLEAN;
}
static inline bool
JSVAL_TO_BOOLEAN_IMPL(jsval_layout l)
{
return (bool)(l.asBits & JSVAL_PAYLOAD_MASK);
}
static inline jsval_layout
BOOLEAN_TO_JSVAL_IMPL(bool b)
{
jsval_layout l;
l.asBits = ((uint64_t)(uint32_t)b) | JSVAL_SHIFTED_TAG_BOOLEAN;
return l;
}
static inline bool
JSVAL_IS_MAGIC_IMPL(jsval_layout l)
{
return (l.asBits >> JSVAL_TAG_SHIFT) == JSVAL_TAG_MAGIC;
}
static inline bool
JSVAL_IS_PRIMITIVE_IMPL(jsval_layout l)
{
return l.asBits < JSVAL_UPPER_EXCL_SHIFTED_TAG_OF_PRIMITIVE_SET;
}
static inline bool
JSVAL_IS_OBJECT_IMPL(jsval_layout l)
{
MOZ_ASSERT((l.asBits >> JSVAL_TAG_SHIFT) <= JSVAL_TAG_OBJECT);
return l.asBits >= JSVAL_SHIFTED_TAG_OBJECT;
}
static inline bool
JSVAL_IS_OBJECT_OR_NULL_IMPL(jsval_layout l)
{
MOZ_ASSERT((l.asBits >> JSVAL_TAG_SHIFT) <= JSVAL_TAG_OBJECT);
return l.asBits >= JSVAL_LOWER_INCL_SHIFTED_TAG_OF_OBJ_OR_NULL_SET;
}
static inline JSObject *
JSVAL_TO_OBJECT_IMPL(jsval_layout l)
{
uint64_t ptrBits = l.asBits & JSVAL_PAYLOAD_MASK;
MOZ_ASSERT((ptrBits & 0x7) == 0);
return (JSObject *)ptrBits;
}
static inline jsval_layout
OBJECT_TO_JSVAL_IMPL(JSObject *obj)
{
jsval_layout l;
uint64_t objBits = (uint64_t)obj;
MOZ_ASSERT(uintptr_t(obj) > 0x1000 || uintptr_t(obj) == 0x42);
MOZ_ASSERT((objBits >> JSVAL_TAG_SHIFT) == 0);
l.asBits = objBits | JSVAL_SHIFTED_TAG_OBJECT;
return l;
}
static inline bool
JSVAL_IS_NULL_IMPL(jsval_layout l)
{
return l.asBits == JSVAL_SHIFTED_TAG_NULL;
}
static inline bool
JSVAL_IS_GCTHING_IMPL(jsval_layout l)
{
return l.asBits >= JSVAL_LOWER_INCL_SHIFTED_TAG_OF_GCTHING_SET;
}
static inline js::gc::Cell *
JSVAL_TO_GCTHING_IMPL(jsval_layout l)
{
uint64_t ptrBits = l.asBits & JSVAL_PAYLOAD_MASK;
MOZ_ASSERT((ptrBits & 0x7) == 0);
return reinterpret_cast<js::gc::Cell *>(ptrBits);
}
static inline bool
JSVAL_IS_TRACEABLE_IMPL(jsval_layout l)
{
return JSVAL_IS_GCTHING_IMPL(l) && !JSVAL_IS_NULL_IMPL(l);
}
static inline uint32_t
JSVAL_TRACE_KIND_IMPL(jsval_layout l)
{
return (uint32_t)(bool)!(JSVAL_IS_OBJECT_IMPL(l));
}
static inline jsval_layout
PRIVATE_PTR_TO_JSVAL_IMPL(void *ptr)
{
jsval_layout l;
uint64_t ptrBits = (uint64_t)ptr;
MOZ_ASSERT((ptrBits & 1) == 0);
l.asBits = ptrBits >> 1;
MOZ_ASSERT(JSVAL_IS_DOUBLE_IMPL(l));
return l;
}
static inline void *
JSVAL_TO_PRIVATE_PTR_IMPL(jsval_layout l)
{
MOZ_ASSERT((l.asBits & 0x8000000000000000LL) == 0);
return (void *)(l.asBits << 1);
}
static inline bool
JSVAL_IS_SPECIFIC_INT32_IMPL(jsval_layout l, int32_t i32)
{
return l.asBits == (((uint64_t)(uint32_t)i32) | JSVAL_SHIFTED_TAG_INT32);
}
static inline bool
JSVAL_IS_SPECIFIC_BOOLEAN_IMPL(jsval_layout l, bool b)
{
return l.asBits == (((uint64_t)(uint32_t)b) | JSVAL_SHIFTED_TAG_BOOLEAN);
}
static inline jsval_layout
MAGIC_TO_JSVAL_IMPL(JSWhyMagic why)
{
jsval_layout l;
l.asBits = ((uint64_t)(uint32_t)why) | JSVAL_SHIFTED_TAG_MAGIC;
return l;
}
static inline jsval_layout
MAGIC_UINT32_TO_JSVAL_IMPL(uint32_t payload)
{
jsval_layout l;
l.asBits = ((uint64_t)payload) | JSVAL_SHIFTED_TAG_MAGIC;
return l;
}
static inline bool
JSVAL_SAME_TYPE_IMPL(jsval_layout lhs, jsval_layout rhs)
{
uint64_t lbits = lhs.asBits, rbits = rhs.asBits;
return (lbits <= JSVAL_SHIFTED_TAG_MAX_DOUBLE && rbits <= JSVAL_SHIFTED_TAG_MAX_DOUBLE) ||
(((lbits ^ rbits) & 0xFFFF800000000000LL) == 0);
}
static inline JSValueType
JSVAL_EXTRACT_NON_DOUBLE_TYPE_IMPL(jsval_layout l)
{
uint64_t type = (l.asBits >> JSVAL_TAG_SHIFT) & 0xF;
MOZ_ASSERT(type > JSVAL_TYPE_DOUBLE);
return (JSValueType)type;
}
#endif /* JS_PUNBOX64 */
static inline jsval_layout JSVAL_TO_IMPL(JS::Value v);
static inline JS_VALUE_CONSTEXPR JS::Value IMPL_TO_JSVAL(jsval_layout l);
namespace JS {
static inline JS_VALUE_CONSTEXPR JS::Value UndefinedValue();
/**
* Returns a generic quiet NaN value, with all payload bits set to zero.
*
* Among other properties, this NaN's bit pattern conforms to JS::Value's
* bit pattern restrictions.
*/
static MOZ_ALWAYS_INLINE double
GenericNaN()
{
return mozilla::SpecificNaN<double>(0, 0x8000000000000ULL);
}
/* MSVC with PGO miscompiles this function. */
#if defined(_MSC_VER)
# pragma optimize("g", off)
#endif
static inline double
CanonicalizeNaN(double d)
{
if (MOZ_UNLIKELY(mozilla::IsNaN(d)))
return GenericNaN();
return d;
}
#if defined(_MSC_VER)
# pragma optimize("", on)
#endif
/*
* JS::Value is the interface for a single JavaScript Engine value. A few
* general notes on JS::Value:
*
* - JS::Value has setX() and isX() members for X in
*
* { Int32, Double, String, Boolean, Undefined, Null, Object, Magic }
*
* JS::Value also contains toX() for each of the non-singleton types.
*
* - Magic is a singleton type whose payload contains either a JSWhyMagic "reason" for
* the magic value or a uint32_t value. By providing JSWhyMagic values when
* creating and checking for magic values, it is possible to assert, at
* runtime, that only magic values with the expected reason flow through a
* particular value. For example, if cx->exception has a magic value, the
* reason must be JS_GENERATOR_CLOSING.
*
* - The JS::Value operations are preferred. The JSVAL_* operations remain for
* compatibility; they may be removed at some point. These operations mostly
* provide similar functionality. But there are a few key differences. One
* is that JS::Value gives null a separate type.
* Also, to help prevent mistakenly boxing a nullable JSObject* as an object,
* Value::setObject takes a JSObject&. (Conversely, Value::toObject returns a
* JSObject&.) A convenience member Value::setObjectOrNull is provided.
*
* - JSVAL_VOID is the same as the singleton value of the Undefined type.
*
* - Note that JS::Value is 8 bytes on 32 and 64-bit architectures. Thus, on
* 32-bit user code should avoid copying jsval/JS::Value as much as possible,
* preferring to pass by const Value &.
*/
class Value
{
public:
/*
* N.B. the default constructor leaves Value unitialized. Adding a default
* constructor prevents Value from being stored in a union.
*/
#if defined(JS_VALUE_IS_CONSTEXPR)
Value() = default;
Value(const Value& v) = default;
#endif
/*** Mutators ***/
void setNull() {
data.asBits = BUILD_JSVAL(JSVAL_TAG_NULL, 0).asBits;
}
void setUndefined() {
data.asBits = BUILD_JSVAL(JSVAL_TAG_UNDEFINED, 0).asBits;
}
void setInt32(int32_t i) {
data = INT32_TO_JSVAL_IMPL(i);
}
int32_t &getInt32Ref() {
MOZ_ASSERT(isInt32());
return data.s.payload.i32;
}
void setDouble(double d) {
data = DOUBLE_TO_JSVAL_IMPL(d);
}
void setNaN() {
setDouble(GenericNaN());
}
double &getDoubleRef() {
MOZ_ASSERT(isDouble());
return data.asDouble;
}
void setString(JSString *str) {
MOZ_ASSERT(!IsPoisonedPtr(str));
data = STRING_TO_JSVAL_IMPL(str);
}
void setObject(JSObject &obj) {
MOZ_ASSERT(!IsPoisonedPtr(&obj));
data = OBJECT_TO_JSVAL_IMPL(&obj);
}
void setBoolean(bool b) {
data = BOOLEAN_TO_JSVAL_IMPL(b);
}
void setMagic(JSWhyMagic why) {
data = MAGIC_TO_JSVAL_IMPL(why);
}
void setMagicUint32(uint32_t payload) {
data = MAGIC_UINT32_TO_JSVAL_IMPL(payload);
}
bool setNumber(uint32_t ui) {
if (ui > JSVAL_INT_MAX) {
setDouble((double)ui);
return false;
} else {
setInt32((int32_t)ui);
return true;
}
}
bool setNumber(double d) {
int32_t i;
if (mozilla::NumberIsInt32(d, &i)) {
setInt32(i);
return true;
}
setDouble(d);
return false;
}
void setObjectOrNull(JSObject *arg) {
if (arg)
setObject(*arg);
else
setNull();
}
void swap(Value &rhs) {
uint64_t tmp = rhs.data.asBits;
rhs.data.asBits = data.asBits;
data.asBits = tmp;
}
/*** Value type queries ***/
bool isUndefined() const {
return JSVAL_IS_UNDEFINED_IMPL(data);
}
bool isNull() const {
return JSVAL_IS_NULL_IMPL(data);
}
bool isNullOrUndefined() const {
return isNull() || isUndefined();
}
bool isInt32() const {
return JSVAL_IS_INT32_IMPL(data);
}
bool isInt32(int32_t i32) const {
return JSVAL_IS_SPECIFIC_INT32_IMPL(data, i32);
}
bool isDouble() const {
return JSVAL_IS_DOUBLE_IMPL(data);
}
bool isNumber() const {
return JSVAL_IS_NUMBER_IMPL(data);
}
bool isString() const {
return JSVAL_IS_STRING_IMPL(data);
}
bool isObject() const {
return JSVAL_IS_OBJECT_IMPL(data);
}
bool isPrimitive() const {
return JSVAL_IS_PRIMITIVE_IMPL(data);
}
bool isObjectOrNull() const {
return JSVAL_IS_OBJECT_OR_NULL_IMPL(data);
}
bool isGCThing() const {
return JSVAL_IS_GCTHING_IMPL(data);
}
bool isBoolean() const {
return JSVAL_IS_BOOLEAN_IMPL(data);
}
bool isTrue() const {
return JSVAL_IS_SPECIFIC_BOOLEAN_IMPL(data, true);
}
bool isFalse() const {
return JSVAL_IS_SPECIFIC_BOOLEAN_IMPL(data, false);
}
bool isMagic() const {
return JSVAL_IS_MAGIC_IMPL(data);
}
bool isMagic(JSWhyMagic why) const {
MOZ_ASSERT_IF(isMagic(), data.s.payload.why == why);
return JSVAL_IS_MAGIC_IMPL(data);
}
bool isMarkable() const {
return JSVAL_IS_TRACEABLE_IMPL(data);
}
JSGCTraceKind gcKind() const {
MOZ_ASSERT(isMarkable());
return JSGCTraceKind(JSVAL_TRACE_KIND_IMPL(data));
}
JSWhyMagic whyMagic() const {
MOZ_ASSERT(isMagic());
return data.s.payload.why;
}
uint32_t magicUint32() const {
MOZ_ASSERT(isMagic());
return data.s.payload.u32;
}
/*** Comparison ***/
bool operator==(const Value &rhs) const {
return data.asBits == rhs.data.asBits;
}
bool operator!=(const Value &rhs) const {
return data.asBits != rhs.data.asBits;
}
friend inline bool SameType(const Value &lhs, const Value &rhs);
/*** Extract the value's typed payload ***/
int32_t toInt32() const {
MOZ_ASSERT(isInt32());
return JSVAL_TO_INT32_IMPL(data);
}
double toDouble() const {
MOZ_ASSERT(isDouble());
return data.asDouble;
}
double toNumber() const {
MOZ_ASSERT(isNumber());
return isDouble() ? toDouble() : double(toInt32());
}
JSString *toString() const {
MOZ_ASSERT(isString());
return JSVAL_TO_STRING_IMPL(data);
}
JSObject &toObject() const {
MOZ_ASSERT(isObject());
return *JSVAL_TO_OBJECT_IMPL(data);
}
JSObject *toObjectOrNull() const {
MOZ_ASSERT(isObjectOrNull());
return JSVAL_TO_OBJECT_IMPL(data);
}
js::gc::Cell *toGCThing() const {
MOZ_ASSERT(isGCThing());
return JSVAL_TO_GCTHING_IMPL(data);
}
bool toBoolean() const {
MOZ_ASSERT(isBoolean());
return JSVAL_TO_BOOLEAN_IMPL(data);
}
uint32_t payloadAsRawUint32() const {
MOZ_ASSERT(!isDouble());
return data.s.payload.u32;
}
uint64_t asRawBits() const {
return data.asBits;
}
JSValueType extractNonDoubleType() const {
return JSVAL_EXTRACT_NON_DOUBLE_TYPE_IMPL(data);
}
/*
* Private API
*
* Private setters/getters allow the caller to read/write arbitrary types
* that fit in the 64-bit payload. It is the caller's responsibility, after
* storing to a value with setPrivateX to read only using getPrivateX.
* Privates values are given a type which ensures they are not marked.
*/
void setPrivate(void *ptr) {
data = PRIVATE_PTR_TO_JSVAL_IMPL(ptr);
}
void *toPrivate() const {
MOZ_ASSERT(JSVAL_IS_DOUBLE_IMPL(data));
return JSVAL_TO_PRIVATE_PTR_IMPL(data);
}
void setPrivateUint32(uint32_t ui) {
MOZ_ASSERT(uint32_t(int32_t(ui)) == ui);
setInt32(int32_t(ui));
}
uint32_t toPrivateUint32() const {
return uint32_t(toInt32());
}
/*
* An unmarked value is just a void* cast as a Value. Thus, the Value is
* not safe for GC and must not be marked. This API avoids raw casts
* and the ensuing strict-aliasing warnings.
*/
void setUnmarkedPtr(void *ptr) {
data.asPtr = ptr;
}
void *toUnmarkedPtr() const {
return data.asPtr;
}
const size_t *payloadWord() const {
#if defined(JS_NUNBOX32)
return &data.s.payload.word;
#elif defined(JS_PUNBOX64)
return &data.asWord;
#endif
}
const uintptr_t *payloadUIntPtr() const {
#if defined(JS_NUNBOX32)
return &data.s.payload.uintptr;
#elif defined(JS_PUNBOX64)
return &data.asUIntPtr;
#endif
}
#if !defined(_MSC_VER) && !defined(__sparc)
// Value must be POD so that MSVC will pass it by value and not in memory
// (bug 689101); the same is true for SPARC as well (bug 737344). More
// precisely, we don't want Value return values compiled as out params.
private:
#endif
jsval_layout data;
private:
#if defined(JS_VALUE_IS_CONSTEXPR)
MOZ_IMPLICIT JS_VALUE_CONSTEXPR Value(jsval_layout layout) : data(layout) {}
#endif
void staticAssertions() {
JS_STATIC_ASSERT(sizeof(JSValueType) == 1);
JS_STATIC_ASSERT(sizeof(JSValueTag) == 4);
JS_STATIC_ASSERT(sizeof(JSWhyMagic) <= 4);
JS_STATIC_ASSERT(sizeof(Value) == 8);
}
friend jsval_layout (::JSVAL_TO_IMPL)(Value);
friend Value JS_VALUE_CONSTEXPR (::IMPL_TO_JSVAL)(jsval_layout l);
friend Value JS_VALUE_CONSTEXPR (JS::UndefinedValue)();
};
inline bool
IsPoisonedValue(const Value &v)
{
if (v.isString())
return IsPoisonedPtr(v.toString());
if (v.isObject())
return IsPoisonedPtr(&v.toObject());
return false;
}
inline bool
IsOptimizedPlaceholderMagicValue(const Value &v)
{
if (v.isMagic()) {
MOZ_ASSERT(v.whyMagic() == JS_OPTIMIZED_ARGUMENTS || v.whyMagic() == JS_OPTIMIZED_OUT);
return true;
}
return false;
}
static MOZ_ALWAYS_INLINE void
ExposeValueToActiveJS(const Value &v)
{
if (v.isMarkable())
ExposeGCThingToActiveJS(v.toGCThing(), v.gcKind());
}
/************************************************************************/
static inline Value
NullValue()
{
Value v;
v.setNull();
return v;
}
static inline JS_VALUE_CONSTEXPR Value
UndefinedValue()
{
#if defined(JS_VALUE_IS_CONSTEXPR)
return Value(BUILD_JSVAL(JSVAL_TAG_UNDEFINED, 0));
#else
JS::Value v;
v.setUndefined();
return v;
#endif
}
static inline Value
Int32Value(int32_t i32)
{
Value v;
v.setInt32(i32);
return v;
}
static inline Value
DoubleValue(double dbl)
{
Value v;
v.setDouble(dbl);
return v;
}
static inline Value
DoubleNaNValue()
{
Value v;
v.setNaN();
return v;
}
static inline Value
Float32Value(float f)
{
Value v;
v.setDouble(f);
return v;
}
static inline Value
StringValue(JSString *str)
{
Value v;
v.setString(str);
return v;
}
static inline Value
BooleanValue(bool boo)
{
Value v;
v.setBoolean(boo);
return v;
}
static inline Value
TrueValue()
{
Value v;
v.setBoolean(true);
return v;
}
static inline Value
FalseValue()
{
Value v;
v.setBoolean(false);
return v;
}
static inline Value
ObjectValue(JSObject &obj)
{
Value v;
v.setObject(obj);
return v;
}
static inline Value
ObjectValueCrashOnTouch()
{
Value v;
v.setObject(*reinterpret_cast<JSObject *>(0x42));
return v;
}
static inline Value
MagicValue(JSWhyMagic why)
{
Value v;
v.setMagic(why);
return v;
}
static inline Value
MagicValueUint32(uint32_t payload)
{
Value v;
v.setMagicUint32(payload);
return v;
}
static inline Value
NumberValue(float f)
{
Value v;
v.setNumber(f);
return v;
}
static inline Value
NumberValue(double dbl)
{
Value v;
v.setNumber(dbl);
return v;
}
static inline Value
NumberValue(int8_t i)
{
return Int32Value(i);
}
static inline Value
NumberValue(uint8_t i)
{
return Int32Value(i);
}
static inline Value
NumberValue(int16_t i)
{
return Int32Value(i);
}
static inline Value
NumberValue(uint16_t i)
{
return Int32Value(i);
}
static inline Value
NumberValue(int32_t i)
{
return Int32Value(i);
}
static inline Value
NumberValue(uint32_t i)
{
Value v;
v.setNumber(i);
return v;
}
namespace detail {
template <bool Signed>
class MakeNumberValue
{
public:
template<typename T>
static inline Value create(const T t)
{
Value v;
if (JSVAL_INT_MIN <= t && t <= JSVAL_INT_MAX)
v.setInt32(int32_t(t));
else
v.setDouble(double(t));
return v;
}
};
template <>
class MakeNumberValue<false>
{
public:
template<typename T>
static inline Value create(const T t)
{
Value v;
if (t <= JSVAL_INT_MAX)
v.setInt32(int32_t(t));
else
v.setDouble(double(t));
return v;
}
};
} // namespace detail
template <typename T>
static inline Value
NumberValue(const T t)
{
MOZ_ASSERT(T(double(t)) == t, "value creation would be lossy");
return detail::MakeNumberValue<std::numeric_limits<T>::is_signed>::create(t);
}
static inline Value
ObjectOrNullValue(JSObject *obj)
{
Value v;
v.setObjectOrNull(obj);
return v;
}
static inline Value
PrivateValue(void *ptr)
{
Value v;
v.setPrivate(ptr);
return v;
}
static inline Value
PrivateUint32Value(uint32_t ui)
{
Value v;
v.setPrivateUint32(ui);
return v;
}
inline bool
SameType(const Value &lhs, const Value &rhs)
{
return JSVAL_SAME_TYPE_IMPL(lhs.data, rhs.data);
}
} // namespace JS
/************************************************************************/
#ifdef JSGC_GENERATIONAL
namespace JS {
JS_PUBLIC_API(void) HeapValuePostBarrier(Value *valuep);
JS_PUBLIC_API(void) HeapValueRelocate(Value *valuep);
}
#endif
namespace js {
template <> struct GCMethods<const JS::Value>
{
static JS::Value initial() { return JS::UndefinedValue(); }
static bool poisoned(const JS::Value &v) { return JS::IsPoisonedValue(v); }
};
template <> struct GCMethods<JS::Value>
{
static JS::Value initial() { return JS::UndefinedValue(); }
static bool poisoned(const JS::Value &v) { return JS::IsPoisonedValue(v); }
static bool needsPostBarrier(const JS::Value &v) {
return v.isObject() && gc::IsInsideNursery(reinterpret_cast<gc::Cell*>(&v.toObject()));
}
#ifdef JSGC_GENERATIONAL
static void postBarrier(JS::Value *v) { JS::HeapValuePostBarrier(v); }
static void relocate(JS::Value *v) { JS::HeapValueRelocate(v); }
#endif
};
template <class Outer> class MutableValueOperations;
/*
* A class designed for CRTP use in implementing the non-mutating parts of the
* Value interface in Value-like classes. Outer must be a class inheriting
* ValueOperations<Outer> with a visible extract() method returning the
* const Value* abstracted by Outer.
*/
template <class Outer>
class ValueOperations
{
friend class MutableValueOperations<Outer>;
const JS::Value * value() const { return static_cast<const Outer*>(this)->extract(); }
public:
bool isUndefined() const { return value()->isUndefined(); }
bool isNull() const { return value()->isNull(); }
bool isBoolean() const { return value()->isBoolean(); }
bool isTrue() const { return value()->isTrue(); }
bool isFalse() const { return value()->isFalse(); }
bool isNumber() const { return value()->isNumber(); }
bool isInt32() const { return value()->isInt32(); }
bool isDouble() const { return value()->isDouble(); }
bool isString() const { return value()->isString(); }
bool isObject() const { return value()->isObject(); }
bool isMagic() const { return value()->isMagic(); }
bool isMagic(JSWhyMagic why) const { return value()->isMagic(why); }
bool isMarkable() const { return value()->isMarkable(); }
bool isPrimitive() const { return value()->isPrimitive(); }
bool isGCThing() const { return value()->isGCThing(); }
bool isNullOrUndefined() const { return value()->isNullOrUndefined(); }
bool isObjectOrNull() const { return value()->isObjectOrNull(); }
bool toBoolean() const { return value()->toBoolean(); }
double toNumber() const { return value()->toNumber(); }
int32_t toInt32() const { return value()->toInt32(); }
double toDouble() const { return value()->toDouble(); }
JSString *toString() const { return value()->toString(); }
JSObject &toObject() const { return value()->toObject(); }
JSObject *toObjectOrNull() const { return value()->toObjectOrNull(); }
void *toGCThing() const { return value()->toGCThing(); }
uint64_t asRawBits() const { return value()->asRawBits(); }
JSValueType extractNonDoubleType() const { return value()->extractNonDoubleType(); }
uint32_t toPrivateUint32() const { return value()->toPrivateUint32(); }
JSWhyMagic whyMagic() const { return value()->whyMagic(); }
uint32_t magicUint32() const { return value()->magicUint32(); }
};
/*
* A class designed for CRTP use in implementing all the mutating parts of the
* Value interface in Value-like classes. Outer must be a class inheriting
* MutableValueOperations<Outer> with visible extractMutable() and extract()
* methods returning the const Value* and Value* abstracted by Outer.
*/
template <class Outer>
class MutableValueOperations : public ValueOperations<Outer>
{
JS::Value * value() { return static_cast<Outer*>(this)->extractMutable(); }
public:
void setNull() { value()->setNull(); }
void setUndefined() { value()->setUndefined(); }
void setInt32(int32_t i) { value()->setInt32(i); }
void setDouble(double d) { value()->setDouble(d); }
void setNaN() { setDouble(JS::GenericNaN()); }
void setBoolean(bool b) { value()->setBoolean(b); }
void setMagic(JSWhyMagic why) { value()->setMagic(why); }
bool setNumber(uint32_t ui) { return value()->setNumber(ui); }
bool setNumber(double d) { return value()->setNumber(d); }
void setString(JSString *str) { this->value()->setString(str); }
void setObject(JSObject &obj) { this->value()->setObject(obj); }
void setObjectOrNull(JSObject *arg) { this->value()->setObjectOrNull(arg); }
};
/*
* Augment the generic Heap<T> interface when T = Value with
* type-querying, value-extracting, and mutating operations.
*/
template <>
class HeapBase<JS::Value> : public ValueOperations<JS::Heap<JS::Value> >
{
typedef JS::Heap<JS::Value> Outer;
friend class ValueOperations<Outer>;
const JS::Value * extract() const { return static_cast<const Outer*>(this)->address(); }
void setBarriered(const JS::Value &v) {
static_cast<JS::Heap<JS::Value> *>(this)->set(v);
}
public:
void setNull() { setBarriered(JS::NullValue()); }
void setUndefined() { setBarriered(JS::UndefinedValue()); }
void setInt32(int32_t i) { setBarriered(JS::Int32Value(i)); }
void setDouble(double d) { setBarriered(JS::DoubleValue(d)); }
void setNaN() { setDouble(JS::GenericNaN()); }
void setBoolean(bool b) { setBarriered(JS::BooleanValue(b)); }
void setMagic(JSWhyMagic why) { setBarriered(JS::MagicValue(why)); }
void setString(JSString *str) { setBarriered(JS::StringValue(str)); }
void setObject(JSObject &obj) { setBarriered(JS::ObjectValue(obj)); }
bool setNumber(uint32_t ui) {
if (ui > JSVAL_INT_MAX) {
setDouble((double)ui);
return false;
} else {
setInt32((int32_t)ui);
return true;
}
}
bool setNumber(double d) {
int32_t i;
if (mozilla::NumberIsInt32(d, &i)) {
setInt32(i);
return true;
}
setDouble(d);
return false;
}
void setObjectOrNull(JSObject *arg) {
if (arg)
setObject(*arg);
else
setNull();
}
};
/*
* Augment the generic Handle<T> interface when T = Value with type-querying
* and value-extracting operations.
*/
template <>
class HandleBase<JS::Value> : public ValueOperations<JS::Handle<JS::Value> >
{
friend class ValueOperations<JS::Handle<JS::Value> >;
const JS::Value * extract() const {
return static_cast<const JS::Handle<JS::Value>*>(this)->address();
}
};
/*
* Augment the generic MutableHandle<T> interface when T = Value with
* type-querying, value-extracting, and mutating operations.
*/
template <>
class MutableHandleBase<JS::Value> : public MutableValueOperations<JS::MutableHandle<JS::Value> >
{
friend class ValueOperations<JS::MutableHandle<JS::Value> >;
const JS::Value * extract() const {
return static_cast<const JS::MutableHandle<JS::Value>*>(this)->address();
}
friend class MutableValueOperations<JS::MutableHandle<JS::Value> >;
JS::Value * extractMutable() {
return static_cast<JS::MutableHandle<JS::Value>*>(this)->address();
}
};
/*
* Augment the generic Rooted<T> interface when T = Value with type-querying,
* value-extracting, and mutating operations.
*/
template <>
class RootedBase<JS::Value> : public MutableValueOperations<JS::Rooted<JS::Value> >
{
friend class ValueOperations<JS::Rooted<JS::Value> >;
const JS::Value * extract() const {
return static_cast<const JS::Rooted<JS::Value>*>(this)->address();
}
friend class MutableValueOperations<JS::Rooted<JS::Value> >;
JS::Value * extractMutable() {
return static_cast<JS::Rooted<JS::Value>*>(this)->address();
}
};
} // namespace js
inline jsval_layout
JSVAL_TO_IMPL(JS::Value v)
{
return v.data;
}
inline JS_VALUE_CONSTEXPR JS::Value
IMPL_TO_JSVAL(jsval_layout l)
{
#if defined(JS_VALUE_IS_CONSTEXPR)
return JS::Value(l);
#else
JS::Value v;
v.data = l;
return v;
#endif
}
namespace JS {
#ifndef __GNUC__
/*
* The default assignment operator for |struct C| has the signature:
*
* C& C::operator=(const C&)
*
* And in particular requires implicit conversion of |this| to type |C| for the
* return value. But |volatile C| cannot thus be converted to |C|, so just
* doing |sink = hold| as in the non-specialized version would fail to compile.
* Do the assignment on asBits instead, since I don't think we want to give
* jsval_layout an assignment operator returning |volatile jsval_layout|.
*/
template<>
inline Anchor<Value>::~Anchor()
{
volatile uint64_t bits;
bits = JSVAL_TO_IMPL(hold).asBits;
}
#endif
#ifdef JS_DEBUG
namespace detail {
struct ValueAlignmentTester { char c; JS::Value v; };
static_assert(sizeof(ValueAlignmentTester) == 16,
"JS::Value must be 16-byte-aligned");
struct LayoutAlignmentTester { char c; jsval_layout l; };
static_assert(sizeof(LayoutAlignmentTester) == 16,
"jsval_layout must be 16-byte-aligned");
} // namespace detail
#endif /* JS_DEBUG */
} // namespace JS
/*
* JS::Value and jsval are the same type; jsval is the old name, kept around
* for backwards compatibility along with all the JSVAL_* operations below.
* jsval_layout is an implementation detail and should not be used externally.
*/
typedef JS::Value jsval;
static_assert(sizeof(jsval_layout) == sizeof(JS::Value),
"jsval_layout and JS::Value must have identical layouts");
/************************************************************************/
static inline JS_VALUE_CONSTEXPR jsval
INT_TO_JSVAL(int32_t i)
{
return IMPL_TO_JSVAL(INT32_TO_JSVAL_IMPL(i));
}
static inline JS_VALUE_CONSTEXPR jsval
DOUBLE_TO_JSVAL(double d)
{
/*
* This is a manually inlined version of:
* d = JS_CANONICALIZE_NAN(d);
* return IMPL_TO_JSVAL(DOUBLE_TO_JSVAL_IMPL(d));
* because GCC from XCode 3.1.4 miscompiles the above code.
*/
#if defined(JS_VALUE_IS_CONSTEXPR)
return IMPL_TO_JSVAL(MOZ_UNLIKELY(d != d)
? (jsval_layout) { .asBits = 0x7FF8000000000000LL }
: (jsval_layout) { .asDouble = d });
#else
jsval_layout l;
if (MOZ_UNLIKELY(d != d))
l.asBits = 0x7FF8000000000000LL;
else
l.asDouble = d;
return IMPL_TO_JSVAL(l);
#endif
}
static inline JS_VALUE_CONSTEXPR jsval
UINT_TO_JSVAL(uint32_t i)
{
return (i <= JSVAL_INT_MAX
? INT_TO_JSVAL((int32_t)i)
: DOUBLE_TO_JSVAL((double)i));
}
static inline jsval
STRING_TO_JSVAL(JSString *str)
{
return IMPL_TO_JSVAL(STRING_TO_JSVAL_IMPL(str));
}
static inline jsval
OBJECT_TO_JSVAL(JSObject *obj)
{
if (obj)
return IMPL_TO_JSVAL(OBJECT_TO_JSVAL_IMPL(obj));
return IMPL_TO_JSVAL(BUILD_JSVAL(JSVAL_TAG_NULL, 0));
}
static inline jsval
BOOLEAN_TO_JSVAL(bool b)
{
return IMPL_TO_JSVAL(BOOLEAN_TO_JSVAL_IMPL(b));
}
/* To be GC-safe, privates are tagged as doubles. */
static inline jsval
PRIVATE_TO_JSVAL(void *ptr)
{
return IMPL_TO_JSVAL(PRIVATE_PTR_TO_JSVAL_IMPL(ptr));
}
// JS constants. For efficiency, prefer predicates (e.g. v.isNull()) and
// constructing values from scratch (e.g. Int32Value(0)). These constants are
// stored in memory and initialized at startup, so testing against them and
// using them requires memory loads and will be correspondingly slow.
extern JS_PUBLIC_DATA(const jsval) JSVAL_NULL;
extern JS_PUBLIC_DATA(const jsval) JSVAL_ZERO;
extern JS_PUBLIC_DATA(const jsval) JSVAL_ONE;
extern JS_PUBLIC_DATA(const jsval) JSVAL_FALSE;
extern JS_PUBLIC_DATA(const jsval) JSVAL_TRUE;
extern JS_PUBLIC_DATA(const jsval) JSVAL_VOID;
namespace JS {
extern JS_PUBLIC_DATA(const HandleValue) NullHandleValue;
extern JS_PUBLIC_DATA(const HandleValue) UndefinedHandleValue;
extern JS_PUBLIC_DATA(const HandleValue) TrueHandleValue;
extern JS_PUBLIC_DATA(const HandleValue) FalseHandleValue;
}
#undef JS_VALUE_IS_CONSTEXPR
#undef JS_RETURN_LAYOUT_FROM_BITS
#endif /* js_Value_h */
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