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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/. */
/*
* PR assertion checker.
*/
#ifndef jsutil_h
#define jsutil_h
#include "mozilla/Assertions.h"
#include "mozilla/Compiler.h"
#include "mozilla/GuardObjects.h"
#include "mozilla/PodOperations.h"
#include <limits.h>
#include "js/Utility.h"
#include "js/Value.h"
#include "js-confdefs.h"
#define JS_ALWAYS_TRUE(expr) MOZ_ALWAYS_TRUE(expr)
#define JS_ALWAYS_FALSE(expr) MOZ_ALWAYS_FALSE(expr)
#if defined(JS_DEBUG)
# define JS_DIAGNOSTICS_ASSERT(expr) MOZ_ASSERT(expr)
#elif defined(JS_CRASH_DIAGNOSTICS)
# define JS_DIAGNOSTICS_ASSERT(expr) do { if (MOZ_UNLIKELY(!(expr))) MOZ_CRASH(); } while(0)
#else
# define JS_DIAGNOSTICS_ASSERT(expr) ((void) 0)
#endif
static MOZ_ALWAYS_INLINE void*
js_memcpy(void* dst_, const void* src_, size_t len)
{
char* dst = (char*) dst_;
const char* src = (const char*) src_;
MOZ_ASSERT_IF(dst >= src, (size_t) (dst - src) >= len);
MOZ_ASSERT_IF(src >= dst, (size_t) (src - dst) >= len);
return memcpy(dst, src, len);
}
namespace js {
template <class T>
struct AlignmentTestStruct
{
char c;
T t;
};
/* This macro determines the alignment requirements of a type. */
#define JS_ALIGNMENT_OF(t_) \
(sizeof(js::AlignmentTestStruct<t_>) - sizeof(t_))
template <class T>
class AlignedPtrAndFlag
{
uintptr_t bits;
public:
AlignedPtrAndFlag(T* t, bool aFlag) {
MOZ_ASSERT((uintptr_t(t) & 1) == 0);
bits = uintptr_t(t) | uintptr_t(aFlag);
}
T* ptr() const {
return (T*)(bits & ~uintptr_t(1));
}
bool flag() const {
return (bits & 1) != 0;
}
void setPtr(T* t) {
MOZ_ASSERT((uintptr_t(t) & 1) == 0);
bits = uintptr_t(t) | uintptr_t(flag());
}
void setFlag() {
bits |= 1;
}
void unsetFlag() {
bits &= ~uintptr_t(1);
}
void set(T* t, bool aFlag) {
MOZ_ASSERT((uintptr_t(t) & 1) == 0);
bits = uintptr_t(t) | aFlag;
}
};
template <class T>
static inline void
Reverse(T* beg, T* end)
{
while (beg != end) {
if (--end == beg)
return;
T tmp = *beg;
*beg = *end;
*end = tmp;
++beg;
}
}
template <class T>
static inline T*
Find(T* beg, T* end, const T& v)
{
for (T* p = beg; p != end; ++p) {
if (*p == v)
return p;
}
return end;
}
template <class Container>
static inline typename Container::ElementType*
Find(Container& c, const typename Container::ElementType& v)
{
return Find(c.begin(), c.end(), v);
}
template <typename InputIterT, typename CallableT>
void
ForEach(InputIterT begin, InputIterT end, CallableT f)
{
for (; begin != end; ++begin)
f(*begin);
}
template <class T>
static inline T
Min(T t1, T t2)
{
return t1 < t2 ? t1 : t2;
}
template <class T>
static inline T
Max(T t1, T t2)
{
return t1 > t2 ? t1 : t2;
}
/* Allows a const variable to be initialized after its declaration. */
template <class T>
static T&
InitConst(const T& t)
{
return const_cast<T&>(t);
}
template <class T, class U>
MOZ_ALWAYS_INLINE T&
ImplicitCast(U& u)
{
T& t = u;
return t;
}
template<typename T>
class MOZ_RAII AutoScopedAssign
{
public:
AutoScopedAssign(T* addr, const T& value
MOZ_GUARD_OBJECT_NOTIFIER_PARAM)
: addr_(addr), old(*addr_)
{
MOZ_GUARD_OBJECT_NOTIFIER_INIT;
*addr_ = value;
}
~AutoScopedAssign() { *addr_ = old; }
private:
MOZ_DECL_USE_GUARD_OBJECT_NOTIFIER
T* addr_;
T old;
};
template <typename T>
static inline bool
IsPowerOfTwo(T t)
{
return t && !(t & (t - 1));
}
template <typename T, typename U>
static inline U
ComputeByteAlignment(T bytes, U alignment)
{
MOZ_ASSERT(IsPowerOfTwo(alignment));
return (alignment - (bytes % alignment)) % alignment;
}
template <typename T, typename U>
static inline T
AlignBytes(T bytes, U alignment)
{
return bytes + ComputeByteAlignment(bytes, alignment);
}
static MOZ_ALWAYS_INLINE size_t
UnsignedPtrDiff(const void* bigger, const void* smaller)
{
return size_t(bigger) - size_t(smaller);
}
/*****************************************************************************/
/* A bit array is an array of bits represented by an array of words (size_t). */
static const size_t BitArrayElementBits = sizeof(size_t) * CHAR_BIT;
static inline unsigned
NumWordsForBitArrayOfLength(size_t length)
{
return (length + (BitArrayElementBits - 1)) / BitArrayElementBits;
}
static inline unsigned
BitArrayIndexToWordIndex(size_t length, size_t bitIndex)
{
unsigned wordIndex = bitIndex / BitArrayElementBits;
MOZ_ASSERT(wordIndex < length);
return wordIndex;
}
static inline size_t
BitArrayIndexToWordMask(size_t i)
{
return size_t(1) << (i % BitArrayElementBits);
}
static inline bool
IsBitArrayElementSet(size_t* array, size_t length, size_t i)
{
return array[BitArrayIndexToWordIndex(length, i)] & BitArrayIndexToWordMask(i);
}
static inline bool
IsAnyBitArrayElementSet(size_t* array, size_t length)
{
unsigned numWords = NumWordsForBitArrayOfLength(length);
for (unsigned i = 0; i < numWords; ++i) {
if (array[i])
return true;
}
return false;
}
static inline void
SetBitArrayElement(size_t* array, size_t length, size_t i)
{
array[BitArrayIndexToWordIndex(length, i)] |= BitArrayIndexToWordMask(i);
}
static inline void
ClearBitArrayElement(size_t* array, size_t length, size_t i)
{
array[BitArrayIndexToWordIndex(length, i)] &= ~BitArrayIndexToWordMask(i);
}
static inline void
ClearAllBitArrayElements(size_t* array, size_t length)
{
for (unsigned i = 0; i < length; ++i)
array[i] = 0;
}
} /* namespace js */
namespace mozilla {
/**
* Set the first |aNElem| T elements in |aDst| to |aSrc|.
*/
template<typename T>
static MOZ_ALWAYS_INLINE void
PodSet(T* aDst, T aSrc, size_t aNElem)
{
for (const T* dstend = aDst + aNElem; aDst < dstend; ++aDst)
*aDst = aSrc;
}
} /* namespace mozilla */
static inline void*
Poison(void* ptr, uint8_t value, size_t num)
{
static bool disablePoison = bool(js_sb_getenv("JSGC_DISABLE_POISONING"));
if (disablePoison)
return ptr;
// Without a valid Value tag, a poisoned Value may look like a valid
// floating point number. To ensure that we crash more readily when
// observing a poisoned Value, we make the poison an invalid ObjectValue.
// Unfortunately, this adds about 2% more overhead, so we can only enable
// it in debug.
#if defined(DEBUG)
uintptr_t obj;
memset(&obj, value, sizeof(obj));
# if defined(JS_PUNBOX64)
obj = obj & ((uintptr_t(1) << JSVAL_TAG_SHIFT) - 1);
# endif
const jsval_layout layout = OBJECT_TO_JSVAL_IMPL((JSObject*)obj);
size_t value_count = num / sizeof(jsval_layout);
size_t byte_count = num % sizeof(jsval_layout);
mozilla::PodSet((jsval_layout*)ptr, layout, value_count);
if (byte_count) {
uint8_t* bytes = static_cast<uint8_t*>(ptr);
uint8_t* end = bytes + num;
mozilla::PodSet(end - byte_count, value, byte_count);
}
#else // !DEBUG
memset(ptr, value, num);
#endif // !DEBUG
return ptr;
}
/* Crash diagnostics by default in debug and on nightly channel. */
#if (defined(DEBUG) || defined(NIGHTLY_BUILD)) && !defined(MOZ_ASAN)
# define JS_CRASH_DIAGNOSTICS 1
#endif
/* Enable poisoning in crash-diagnostics and zeal builds. */
#if defined(JS_CRASH_DIAGNOSTICS) || defined(JS_GC_ZEAL)
# define JS_POISON(p, val, size) Poison(p, val, size)
#else
# define JS_POISON(p, val, size) ((void) 0)
#endif
/* Enable even more poisoning in purely debug builds. */
#if defined(DEBUG)
# define JS_EXTRA_POISON(p, val, size) Poison(p, val, size)
#else
# define JS_EXTRA_POISON(p, val, size) ((void) 0)
#endif
/* Basic stats */
#ifdef DEBUG
# define JS_BASIC_STATS 1
#endif
#ifdef JS_BASIC_STATS
# include <stdio.h>
typedef struct JSBasicStats {
uint32_t num;
uint32_t max;
double sum;
double sqsum;
uint32_t logscale; /* logarithmic scale: 0 (linear), 2, 10 */
uint32_t hist[11];
} JSBasicStats;
# define JS_INIT_STATIC_BASIC_STATS {0,0,0,0,0,{0,0,0,0,0,0,0,0,0,0,0}}
# define JS_BASIC_STATS_INIT(bs) memset((bs), 0, sizeof(JSBasicStats))
# define JS_BASIC_STATS_ACCUM(bs,val) \
JS_BasicStatsAccum(bs, val)
# define JS_MeanAndStdDevBS(bs,sigma) \
JS_MeanAndStdDev((bs)->num, (bs)->sum, (bs)->sqsum, sigma)
extern void
JS_BasicStatsAccum(JSBasicStats* bs, uint32_t val);
extern double
JS_MeanAndStdDev(uint32_t num, double sum, double sqsum, double* sigma);
extern void
JS_DumpBasicStats(JSBasicStats* bs, const char* title, FILE* fp);
extern void
JS_DumpHistogram(JSBasicStats* bs, FILE* fp);
#else
# define JS_BASIC_STATS_ACCUM(bs,val)
#endif
/* A jsbitmap_t is a long integer that can be used for bitmaps. */
typedef size_t jsbitmap;
#define JS_BITMAP_NBITS (sizeof(jsbitmap) * CHAR_BIT)
#define JS_TEST_BIT(_map,_bit) ((_map)[(_bit)/JS_BITMAP_NBITS] & \
(jsbitmap(1)<<((_bit)%JS_BITMAP_NBITS)))
#define JS_SET_BIT(_map,_bit) ((_map)[(_bit)/JS_BITMAP_NBITS] |= \
(jsbitmap(1)<<((_bit)%JS_BITMAP_NBITS)))
#define JS_CLEAR_BIT(_map,_bit) ((_map)[(_bit)/JS_BITMAP_NBITS] &= \
~(jsbitmap(1)<<((_bit)%JS_BITMAP_NBITS)))
/* Wrapper for various macros to stop warnings coming from their expansions. */
#if defined(__clang__)
# define JS_SILENCE_UNUSED_VALUE_IN_EXPR(expr) \
JS_BEGIN_MACRO \
_Pragma("clang diagnostic push") \
/* If these _Pragmas cause warnings for you, try disabling ccache. */ \
_Pragma("clang diagnostic ignored \"-Wunused-value\"") \
{ expr; } \
_Pragma("clang diagnostic pop") \
JS_END_MACRO
#elif MOZ_IS_GCC
# define JS_SILENCE_UNUSED_VALUE_IN_EXPR(expr) \
JS_BEGIN_MACRO \
_Pragma("GCC diagnostic push") \
_Pragma("GCC diagnostic ignored \"-Wunused-but-set-variable\"") \
expr; \
_Pragma("GCC diagnostic pop") \
JS_END_MACRO
#endif
#if !defined(JS_SILENCE_UNUSED_VALUE_IN_EXPR)
# define JS_SILENCE_UNUSED_VALUE_IN_EXPR(expr) \
JS_BEGIN_MACRO \
expr; \
JS_END_MACRO
#endif
#endif /* jsutil_h */