// 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_UTILS_H_
#define V8_UTILS_H_
#include <limits.h>
#include <stdlib.h>
#include <string.h>
#include <cmath>
#include "include/v8.h"
#include "src/allocation.h"
#include "src/base/bits.h"
#include "src/base/logging.h"
#include "src/base/macros.h"
#include "src/base/platform/platform.h"
#include "src/globals.h"
#include "src/list.h"
#include "src/vector.h"
namespace v8 {
namespace internal {
// ----------------------------------------------------------------------------
// General helper functions
// Same as strcmp, but can handle NULL arguments.
inline bool CStringEquals(const char* s1, const char* s2) {
return (s1 == s2) || (s1 != NULL && s2 != NULL && strcmp(s1, s2) == 0);
}
// X must be a power of 2. Returns the number of trailing zeros.
inline int WhichPowerOf2(uint32_t x) {
DCHECK(base::bits::IsPowerOfTwo32(x));
int bits = 0;
#ifdef DEBUG
int original_x = x;
#endif
if (x >= 0x10000) {
bits += 16;
x >>= 16;
}
if (x >= 0x100) {
bits += 8;
x >>= 8;
}
if (x >= 0x10) {
bits += 4;
x >>= 4;
}
switch (x) {
default: UNREACHABLE();
case 8: bits++; // Fall through.
case 4: bits++; // Fall through.
case 2: bits++; // Fall through.
case 1: break;
}
DCHECK_EQ(1 << bits, original_x);
return bits;
return 0;
}
inline int MostSignificantBit(uint32_t x) {
static const int msb4[] = {0, 1, 2, 2, 3, 3, 3, 3, 4, 4, 4, 4, 4, 4, 4, 4};
int nibble = 0;
if (x & 0xffff0000) {
nibble += 16;
x >>= 16;
}
if (x & 0xff00) {
nibble += 8;
x >>= 8;
}
if (x & 0xf0) {
nibble += 4;
x >>= 4;
}
return nibble + msb4[x];
}
// The C++ standard leaves the semantics of '>>' undefined for
// negative signed operands. Most implementations do the right thing,
// though.
inline int ArithmeticShiftRight(int x, int s) {
return x >> s;
}
template <typename T>
int Compare(const T& a, const T& b) {
if (a == b)
return 0;
else if (a < b)
return -1;
else
return 1;
}
template <typename T>
int PointerValueCompare(const T* a, const T* b) {
return Compare<T>(*a, *b);
}
// Compare function to compare the object pointer value of two
// handlified objects. The handles are passed as pointers to the
// handles.
template<typename T> class Handle; // Forward declaration.
template <typename T>
int HandleObjectPointerCompare(const Handle<T>* a, const Handle<T>* b) {
return Compare<T*>(*(*a), *(*b));
}
template <typename T, typename U>
inline bool IsAligned(T value, U alignment) {
return (value & (alignment - 1)) == 0;
}
// Returns true if (addr + offset) is aligned.
inline bool IsAddressAligned(Address addr,
intptr_t alignment,
int offset = 0) {
intptr_t offs = OffsetFrom(addr + offset);
return IsAligned(offs, alignment);
}
// Returns the maximum of the two parameters.
template <typename T>
T Max(T a, T b) {
return a < b ? b : a;
}
// Returns the minimum of the two parameters.
template <typename T>
T Min(T a, T b) {
return a < b ? a : b;
}
// Returns the absolute value of its argument.
template <typename T>
T Abs(T a) {
return a < 0 ? -a : a;
}
// Floor(-0.0) == 0.0
inline double Floor(double x) {
#ifdef _MSC_VER
if (x == 0) return x; // Fix for issue 3477.
#endif
return std::floor(x);
}
// TODO(svenpanne) Clean up the whole power-of-2 mess.
inline int32_t WhichPowerOf2Abs(int32_t x) {
return (x == kMinInt) ? 31 : WhichPowerOf2(Abs(x));
}
// Obtains the unsigned type corresponding to T
// available in C++11 as std::make_unsigned
template<typename T>
struct make_unsigned {
typedef T type;
};
// Template specializations necessary to have make_unsigned work
template<> struct make_unsigned<int32_t> {
typedef uint32_t type;
};
template<> struct make_unsigned<int64_t> {
typedef uint64_t type;
};
// ----------------------------------------------------------------------------
// BitField is a help template for encoding and decode bitfield with
// unsigned content.
template<class T, int shift, int size, class U>
class BitFieldBase {
public:
// A type U mask of bit field. To use all bits of a type U of x bits
// in a bitfield without compiler warnings we have to compute 2^x
// without using a shift count of x in the computation.
static const U kOne = static_cast<U>(1U);
static const U kMask = ((kOne << shift) << size) - (kOne << shift);
static const U kShift = shift;
static const U kSize = size;
static const U kNext = kShift + kSize;
// Value for the field with all bits set.
static const T kMax = static_cast<T>((1U << size) - 1);
// Tells whether the provided value fits into the bit field.
static bool is_valid(T value) {
return (static_cast<U>(value) & ~static_cast<U>(kMax)) == 0;
}
// Returns a type U with the bit field value encoded.
static U encode(T value) {
DCHECK(is_valid(value));
return static_cast<U>(value) << shift;
}
// Returns a type U with the bit field value updated.
static U update(U previous, T value) {
return (previous & ~kMask) | encode(value);
}
// Extracts the bit field from the value.
static T decode(U value) {
return static_cast<T>((value & kMask) >> shift);
}
};
template<class T, int shift, int size>
class BitField : public BitFieldBase<T, shift, size, uint32_t> { };
template<class T, int shift, int size>
class BitField64 : public BitFieldBase<T, shift, size, uint64_t> { };
// ----------------------------------------------------------------------------
// Hash function.
static const uint32_t kZeroHashSeed = 0;
// Thomas Wang, Integer Hash Functions.
// http://www.concentric.net/~Ttwang/tech/inthash.htm
inline uint32_t ComputeIntegerHash(uint32_t key, uint32_t seed) {
uint32_t hash = key;
hash = hash ^ seed;
hash = ~hash + (hash << 15); // hash = (hash << 15) - hash - 1;
hash = hash ^ (hash >> 12);
hash = hash + (hash << 2);
hash = hash ^ (hash >> 4);
hash = hash * 2057; // hash = (hash + (hash << 3)) + (hash << 11);
hash = hash ^ (hash >> 16);
return hash;
}
inline uint32_t ComputeLongHash(uint64_t key) {
uint64_t hash = key;
hash = ~hash + (hash << 18); // hash = (hash << 18) - hash - 1;
hash = hash ^ (hash >> 31);
hash = hash * 21; // hash = (hash + (hash << 2)) + (hash << 4);
hash = hash ^ (hash >> 11);
hash = hash + (hash << 6);
hash = hash ^ (hash >> 22);
return static_cast<uint32_t>(hash);
}
inline uint32_t ComputePointerHash(void* ptr) {
return ComputeIntegerHash(
static_cast<uint32_t>(reinterpret_cast<intptr_t>(ptr)),
v8::internal::kZeroHashSeed);
}
// ----------------------------------------------------------------------------
// Generated memcpy/memmove
// Initializes the codegen support that depends on CPU features. This is
// called after CPU initialization.
void init_memcopy_functions();
#if defined(V8_TARGET_ARCH_IA32) || defined(V8_TARGET_ARCH_X87)
// Limit below which the extra overhead of the MemCopy function is likely
// to outweigh the benefits of faster copying.
const int kMinComplexMemCopy = 64;
// Copy memory area. No restrictions.
void MemMove(void* dest, const void* src, size_t size);
typedef void (*MemMoveFunction)(void* dest, const void* src, size_t size);
// Keep the distinction of "move" vs. "copy" for the benefit of other
// architectures.
V8_INLINE void MemCopy(void* dest, const void* src, size_t size) {
MemMove(dest, src, size);
}
#elif defined(V8_HOST_ARCH_ARM)
typedef void (*MemCopyUint8Function)(uint8_t* dest, const uint8_t* src,
size_t size);
extern MemCopyUint8Function memcopy_uint8_function;
V8_INLINE void MemCopyUint8Wrapper(uint8_t* dest, const uint8_t* src,
size_t chars) {
memcpy(dest, src, chars);
}
// For values < 16, the assembler function is slower than the inlined C code.
const int kMinComplexMemCopy = 16;
V8_INLINE void MemCopy(void* dest, const void* src, size_t size) {
(*memcopy_uint8_function)(reinterpret_cast<uint8_t*>(dest),
reinterpret_cast<const uint8_t*>(src), size);
}
V8_INLINE void MemMove(void* dest, const void* src, size_t size) {
memmove(dest, src, size);
}
typedef void (*MemCopyUint16Uint8Function)(uint16_t* dest, const uint8_t* src,
size_t size);
extern MemCopyUint16Uint8Function memcopy_uint16_uint8_function;
void MemCopyUint16Uint8Wrapper(uint16_t* dest, const uint8_t* src,
size_t chars);
// For values < 12, the assembler function is slower than the inlined C code.
const int kMinComplexConvertMemCopy = 12;
V8_INLINE void MemCopyUint16Uint8(uint16_t* dest, const uint8_t* src,
size_t size) {
(*memcopy_uint16_uint8_function)(dest, src, size);
}
#elif defined(V8_HOST_ARCH_MIPS)
typedef void (*MemCopyUint8Function)(uint8_t* dest, const uint8_t* src,
size_t size);
extern MemCopyUint8Function memcopy_uint8_function;
V8_INLINE void MemCopyUint8Wrapper(uint8_t* dest, const uint8_t* src,
size_t chars) {
memcpy(dest, src, chars);
}
// For values < 16, the assembler function is slower than the inlined C code.
const int kMinComplexMemCopy = 16;
V8_INLINE void MemCopy(void* dest, const void* src, size_t size) {
(*memcopy_uint8_function)(reinterpret_cast<uint8_t*>(dest),
reinterpret_cast<const uint8_t*>(src), size);
}
V8_INLINE void MemMove(void* dest, const void* src, size_t size) {
memmove(dest, src, size);
}
#else
// Copy memory area to disjoint memory area.
V8_INLINE void MemCopy(void* dest, const void* src, size_t size) {
memcpy(dest, src, size);
}
V8_INLINE void MemMove(void* dest, const void* src, size_t size) {
memmove(dest, src, size);
}
const int kMinComplexMemCopy = 16 * kPointerSize;
#endif // V8_TARGET_ARCH_IA32
// ----------------------------------------------------------------------------
// Miscellaneous
// A static resource holds a static instance that can be reserved in
// a local scope using an instance of Access. Attempts to re-reserve
// the instance will cause an error.
template <typename T>
class StaticResource {
public:
StaticResource() : is_reserved_(false) {}
private:
template <typename S> friend class Access;
T instance_;
bool is_reserved_;
};
// Locally scoped access to a static resource.
template <typename T>
class Access {
public:
explicit Access(StaticResource<T>* resource)
: resource_(resource)
, instance_(&resource->instance_) {
DCHECK(!resource->is_reserved_);
resource->is_reserved_ = true;
}
~Access() {
resource_->is_reserved_ = false;
resource_ = NULL;
instance_ = NULL;
}
T* value() { return instance_; }
T* operator -> () { return instance_; }
private:
StaticResource<T>* resource_;
T* instance_;
};
// A pointer that can only be set once and doesn't allow NULL values.
template<typename T>
class SetOncePointer {
public:
SetOncePointer() : pointer_(NULL) { }
bool is_set() const { return pointer_ != NULL; }
T* get() const {
DCHECK(pointer_ != NULL);
return pointer_;
}
void set(T* value) {
DCHECK(pointer_ == NULL && value != NULL);
pointer_ = value;
}
private:
T* pointer_;
};
template <typename T, int kSize>
class EmbeddedVector : public Vector<T> {
public:
EmbeddedVector() : Vector<T>(buffer_, kSize) { }
explicit EmbeddedVector(T initial_value) : Vector<T>(buffer_, kSize) {
for (int i = 0; i < kSize; ++i) {
buffer_[i] = initial_value;
}
}
// When copying, make underlying Vector to reference our buffer.
EmbeddedVector(const EmbeddedVector& rhs)
: Vector<T>(rhs) {
MemCopy(buffer_, rhs.buffer_, sizeof(T) * kSize);
this->set_start(buffer_);
}
EmbeddedVector& operator=(const EmbeddedVector& rhs) {
if (this == &rhs) return *this;
Vector<T>::operator=(rhs);
MemCopy(buffer_, rhs.buffer_, sizeof(T) * kSize);
this->set_start(buffer_);
return *this;
}
private:
T buffer_[kSize];
};
/*
* A class that collects values into a backing store.
* Specialized versions of the class can allow access to the backing store
* in different ways.
* There is no guarantee that the backing store is contiguous (and, as a
* consequence, no guarantees that consecutively added elements are adjacent
* in memory). The collector may move elements unless it has guaranteed not
* to.
*/
template <typename T, int growth_factor = 2, int max_growth = 1 * MB>
class Collector {
public:
explicit Collector(int initial_capacity = kMinCapacity)
: index_(0), size_(0) {
current_chunk_ = Vector<T>::New(initial_capacity);
}
virtual ~Collector() {
// Free backing store (in reverse allocation order).
current_chunk_.Dispose();
for (int i = chunks_.length() - 1; i >= 0; i--) {
chunks_.at(i).Dispose();
}
}
// Add a single element.
inline void Add(T value) {
if (index_ >= current_chunk_.length()) {
Grow(1);
}
current_chunk_[index_] = value;
index_++;
size_++;
}
// Add a block of contiguous elements and return a Vector backed by the
// memory area.
// A basic Collector will keep this vector valid as long as the Collector
// is alive.
inline Vector<T> AddBlock(int size, T initial_value) {
DCHECK(size > 0);
if (size > current_chunk_.length() - index_) {
Grow(size);
}
T* position = current_chunk_.start() + index_;
index_ += size;
size_ += size;
for (int i = 0; i < size; i++) {
position[i] = initial_value;
}
return Vector<T>(position, size);
}
// Add a contiguous block of elements and return a vector backed
// by the added block.
// A basic Collector will keep this vector valid as long as the Collector
// is alive.
inline Vector<T> AddBlock(Vector<const T> source) {
if (source.length() > current_chunk_.length() - index_) {
Grow(source.length());
}
T* position = current_chunk_.start() + index_;
index_ += source.length();
size_ += source.length();
for (int i = 0; i < source.length(); i++) {
position[i] = source[i];
}
return Vector<T>(position, source.length());
}
// Write the contents of the collector into the provided vector.
void WriteTo(Vector<T> destination) {
DCHECK(size_ <= destination.length());
int position = 0;
for (int i = 0; i < chunks_.length(); i++) {
Vector<T> chunk = chunks_.at(i);
for (int j = 0; j < chunk.length(); j++) {
destination[position] = chunk[j];
position++;
}
}
for (int i = 0; i < index_; i++) {
destination[position] = current_chunk_[i];
position++;
}
}
// Allocate a single contiguous vector, copy all the collected
// elements to the vector, and return it.
// The caller is responsible for freeing the memory of the returned
// vector (e.g., using Vector::Dispose).
Vector<T> ToVector() {
Vector<T> new_store = Vector<T>::New(size_);
WriteTo(new_store);
return new_store;
}
// Resets the collector to be empty.
virtual void Reset();
// Total number of elements added to collector so far.
inline int size() { return size_; }
protected:
static const int kMinCapacity = 16;
List<Vector<T> > chunks_;
Vector<T> current_chunk_; // Block of memory currently being written into.
int index_; // Current index in current chunk.
int size_; // Total number of elements in collector.
// Creates a new current chunk, and stores the old chunk in the chunks_ list.
void Grow(int min_capacity) {
DCHECK(growth_factor > 1);
int new_capacity;
int current_length = current_chunk_.length();
if (current_length < kMinCapacity) {
// The collector started out as empty.
new_capacity = min_capacity * growth_factor;
if (new_capacity < kMinCapacity) new_capacity = kMinCapacity;
} else {
int growth = current_length * (growth_factor - 1);
if (growth > max_growth) {
growth = max_growth;
}
new_capacity = current_length + growth;
if (new_capacity < min_capacity) {
new_capacity = min_capacity + growth;
}
}
NewChunk(new_capacity);
DCHECK(index_ + min_capacity <= current_chunk_.length());
}
// Before replacing the current chunk, give a subclass the option to move
// some of the current data into the new chunk. The function may update
// the current index_ value to represent data no longer in the current chunk.
// Returns the initial index of the new chunk (after copied data).
virtual void NewChunk(int new_capacity) {
Vector<T> new_chunk = Vector<T>::New(new_capacity);
if (index_ > 0) {
chunks_.Add(current_chunk_.SubVector(0, index_));
} else {
current_chunk_.Dispose();
}
current_chunk_ = new_chunk;
index_ = 0;
}
};
/*
* A collector that allows sequences of values to be guaranteed to
* stay consecutive.
* If the backing store grows while a sequence is active, the current
* sequence might be moved, but after the sequence is ended, it will
* not move again.
* NOTICE: Blocks allocated using Collector::AddBlock(int) can move
* as well, if inside an active sequence where another element is added.
*/
template <typename T, int growth_factor = 2, int max_growth = 1 * MB>
class SequenceCollector : public Collector<T, growth_factor, max_growth> {
public:
explicit SequenceCollector(int initial_capacity)
: Collector<T, growth_factor, max_growth>(initial_capacity),
sequence_start_(kNoSequence) { }
virtual ~SequenceCollector() {}
void StartSequence() {
DCHECK(sequence_start_ == kNoSequence);
sequence_start_ = this->index_;
}
Vector<T> EndSequence() {
DCHECK(sequence_start_ != kNoSequence);
int sequence_start = sequence_start_;
sequence_start_ = kNoSequence;
if (sequence_start == this->index_) return Vector<T>();
return this->current_chunk_.SubVector(sequence_start, this->index_);
}
// Drops the currently added sequence, and all collected elements in it.
void DropSequence() {
DCHECK(sequence_start_ != kNoSequence);
int sequence_length = this->index_ - sequence_start_;
this->index_ = sequence_start_;
this->size_ -= sequence_length;
sequence_start_ = kNoSequence;
}
virtual void Reset() {
sequence_start_ = kNoSequence;
this->Collector<T, growth_factor, max_growth>::Reset();
}
private:
static const int kNoSequence = -1;
int sequence_start_;
// Move the currently active sequence to the new chunk.
virtual void NewChunk(int new_capacity) {
if (sequence_start_ == kNoSequence) {
// Fall back on default behavior if no sequence has been started.
this->Collector<T, growth_factor, max_growth>::NewChunk(new_capacity);
return;
}
int sequence_length = this->index_ - sequence_start_;
Vector<T> new_chunk = Vector<T>::New(sequence_length + new_capacity);
DCHECK(sequence_length < new_chunk.length());
for (int i = 0; i < sequence_length; i++) {
new_chunk[i] = this->current_chunk_[sequence_start_ + i];
}
if (sequence_start_ > 0) {
this->chunks_.Add(this->current_chunk_.SubVector(0, sequence_start_));
} else {
this->current_chunk_.Dispose();
}
this->current_chunk_ = new_chunk;
this->index_ = sequence_length;
sequence_start_ = 0;
}
};
// Compare 8bit/16bit chars to 8bit/16bit chars.
template <typename lchar, typename rchar>
inline int CompareCharsUnsigned(const lchar* lhs,
const rchar* rhs,
int chars) {
const lchar* limit = lhs + chars;
if (sizeof(*lhs) == sizeof(char) && sizeof(*rhs) == sizeof(char)) {
// memcmp compares byte-by-byte, yielding wrong results for two-byte
// strings on little-endian systems.
return memcmp(lhs, rhs, chars);
}
while (lhs < limit) {
int r = static_cast<int>(*lhs) - static_cast<int>(*rhs);
if (r != 0) return r;
++lhs;
++rhs;
}
return 0;
}
template<typename lchar, typename rchar>
inline int CompareChars(const lchar* lhs, const rchar* rhs, int chars) {
DCHECK(sizeof(lchar) <= 2);
DCHECK(sizeof(rchar) <= 2);
if (sizeof(lchar) == 1) {
if (sizeof(rchar) == 1) {
return CompareCharsUnsigned(reinterpret_cast<const uint8_t*>(lhs),
reinterpret_cast<const uint8_t*>(rhs),
chars);
} else {
return CompareCharsUnsigned(reinterpret_cast<const uint8_t*>(lhs),
reinterpret_cast<const uint16_t*>(rhs),
chars);
}
} else {
if (sizeof(rchar) == 1) {
return CompareCharsUnsigned(reinterpret_cast<const uint16_t*>(lhs),
reinterpret_cast<const uint8_t*>(rhs),
chars);
} else {
return CompareCharsUnsigned(reinterpret_cast<const uint16_t*>(lhs),
reinterpret_cast<const uint16_t*>(rhs),
chars);
}
}
}
// Calculate 10^exponent.
inline int TenToThe(int exponent) {
DCHECK(exponent <= 9);
DCHECK(exponent >= 1);
int answer = 10;
for (int i = 1; i < exponent; i++) answer *= 10;
return answer;
}
template<typename ElementType, int NumElements>
class EmbeddedContainer {
public:
EmbeddedContainer() : elems_() { }
int length() const { return NumElements; }
const ElementType& operator[](int i) const {
DCHECK(i < length());
return elems_[i];
}
ElementType& operator[](int i) {
DCHECK(i < length());
return elems_[i];
}
private:
ElementType elems_[NumElements];
};
template<typename ElementType>
class EmbeddedContainer<ElementType, 0> {
public:
int length() const { return 0; }
const ElementType& operator[](int i) const {
UNREACHABLE();
static ElementType t = 0;
return t;
}
ElementType& operator[](int i) {
UNREACHABLE();
static ElementType t = 0;
return t;
}
};
// Helper class for building result strings in a character buffer. The
// purpose of the class is to use safe operations that checks the
// buffer bounds on all operations in debug mode.
// This simple base class does not allow formatted output.
class SimpleStringBuilder {
public:
// Create a string builder with a buffer of the given size. The
// buffer is allocated through NewArray<char> and must be
// deallocated by the caller of Finalize().
explicit SimpleStringBuilder(int size);
SimpleStringBuilder(char* buffer, int size)
: buffer_(buffer, size), position_(0) { }
~SimpleStringBuilder() { if (!is_finalized()) Finalize(); }
int size() const { return buffer_.length(); }
// Get the current position in the builder.
int position() const {
DCHECK(!is_finalized());
return position_;
}
// Reset the position.
void Reset() { position_ = 0; }
// Add a single character to the builder. It is not allowed to add
// 0-characters; use the Finalize() method to terminate the string
// instead.
void AddCharacter(char c) {
DCHECK(c != '\0');
DCHECK(!is_finalized() && position_ < buffer_.length());
buffer_[position_++] = c;
}
// Add an entire string to the builder. Uses strlen() internally to
// compute the length of the input string.
void AddString(const char* s);
// Add the first 'n' characters of the given string 's' to the
// builder. The input string must have enough characters.
void AddSubstring(const char* s, int n);
// Add character padding to the builder. If count is non-positive,
// nothing is added to the builder.
void AddPadding(char c, int count);
// Add the decimal representation of the value.
void AddDecimalInteger(int value);
// Finalize the string by 0-terminating it and returning the buffer.
char* Finalize();
protected:
Vector<char> buffer_;
int position_;
bool is_finalized() const { return position_ < 0; }
private:
DISALLOW_IMPLICIT_CONSTRUCTORS(SimpleStringBuilder);
};
// A poor man's version of STL's bitset: A bit set of enums E (without explicit
// values), fitting into an integral type T.
template <class E, class T = int>
class EnumSet {
public:
explicit EnumSet(T bits = 0) : bits_(bits) {}
bool IsEmpty() const { return bits_ == 0; }
bool Contains(E element) const { return (bits_ & Mask(element)) != 0; }
bool ContainsAnyOf(const EnumSet& set) const {
return (bits_ & set.bits_) != 0;
}
void Add(E element) { bits_ |= Mask(element); }
void Add(const EnumSet& set) { bits_ |= set.bits_; }
void Remove(E element) { bits_ &= ~Mask(element); }
void Remove(const EnumSet& set) { bits_ &= ~set.bits_; }
void RemoveAll() { bits_ = 0; }
void Intersect(const EnumSet& set) { bits_ &= set.bits_; }
T ToIntegral() const { return bits_; }
bool operator==(const EnumSet& set) { return bits_ == set.bits_; }
bool operator!=(const EnumSet& set) { return bits_ != set.bits_; }
EnumSet<E, T> operator|(const EnumSet& set) const {
return EnumSet<E, T>(bits_ | set.bits_);
}
private:
T Mask(E element) const {
// The strange typing in DCHECK is necessary to avoid stupid warnings, see:
// http://gcc.gnu.org/bugzilla/show_bug.cgi?id=43680
DCHECK(static_cast<int>(element) < static_cast<int>(sizeof(T) * CHAR_BIT));
return static_cast<T>(1) << element;
}
T bits_;
};
// Bit field extraction.
inline uint32_t unsigned_bitextract_32(int msb, int lsb, uint32_t x) {
return (x >> lsb) & ((1 << (1 + msb - lsb)) - 1);
}
inline uint64_t unsigned_bitextract_64(int msb, int lsb, uint64_t x) {
return (x >> lsb) & ((static_cast<uint64_t>(1) << (1 + msb - lsb)) - 1);
}
inline int32_t signed_bitextract_32(int msb, int lsb, int32_t x) {
return (x << (31 - msb)) >> (lsb + 31 - msb);
}
inline int signed_bitextract_64(int msb, int lsb, int x) {
// TODO(jbramley): This is broken for big bitfields.
return (x << (63 - msb)) >> (lsb + 63 - msb);
}
// Check number width.
inline bool is_intn(int64_t x, unsigned n) {
DCHECK((0 < n) && (n < 64));
int64_t limit = static_cast<int64_t>(1) << (n - 1);
return (-limit <= x) && (x < limit);
}
inline bool is_uintn(int64_t x, unsigned n) {
DCHECK((0 < n) && (n < (sizeof(x) * kBitsPerByte)));
return !(x >> n);
}
template <class T>
inline T truncate_to_intn(T x, unsigned n) {
DCHECK((0 < n) && (n < (sizeof(x) * kBitsPerByte)));
return (x & ((static_cast<T>(1) << n) - 1));
}
#define INT_1_TO_63_LIST(V) \
V(1) V(2) V(3) V(4) V(5) V(6) V(7) V(8) \
V(9) V(10) V(11) V(12) V(13) V(14) V(15) V(16) \
V(17) V(18) V(19) V(20) V(21) V(22) V(23) V(24) \
V(25) V(26) V(27) V(28) V(29) V(30) V(31) V(32) \
V(33) V(34) V(35) V(36) V(37) V(38) V(39) V(40) \
V(41) V(42) V(43) V(44) V(45) V(46) V(47) V(48) \
V(49) V(50) V(51) V(52) V(53) V(54) V(55) V(56) \
V(57) V(58) V(59) V(60) V(61) V(62) V(63)
#define DECLARE_IS_INT_N(N) \
inline bool is_int##N(int64_t x) { return is_intn(x, N); }
#define DECLARE_IS_UINT_N(N) \
template <class T> \
inline bool is_uint##N(T x) { return is_uintn(x, N); }
#define DECLARE_TRUNCATE_TO_INT_N(N) \
template <class T> \
inline T truncate_to_int##N(T x) { return truncate_to_intn(x, N); }
INT_1_TO_63_LIST(DECLARE_IS_INT_N)
INT_1_TO_63_LIST(DECLARE_IS_UINT_N)
INT_1_TO_63_LIST(DECLARE_TRUNCATE_TO_INT_N)
#undef DECLARE_IS_INT_N
#undef DECLARE_IS_UINT_N
#undef DECLARE_TRUNCATE_TO_INT_N
class TypeFeedbackId {
public:
explicit TypeFeedbackId(int id) : id_(id) { }
int ToInt() const { return id_; }
static TypeFeedbackId None() { return TypeFeedbackId(kNoneId); }
bool IsNone() const { return id_ == kNoneId; }
private:
static const int kNoneId = -1;
int id_;
};
class BailoutId {
public:
explicit BailoutId(int id) : id_(id) { }
int ToInt() const { return id_; }
static BailoutId None() { return BailoutId(kNoneId); }
static BailoutId FunctionEntry() { return BailoutId(kFunctionEntryId); }
static BailoutId Declarations() { return BailoutId(kDeclarationsId); }
static BailoutId FirstUsable() { return BailoutId(kFirstUsableId); }
static BailoutId StubEntry() { return BailoutId(kStubEntryId); }
bool IsNone() const { return id_ == kNoneId; }
bool operator==(const BailoutId& other) const { return id_ == other.id_; }
bool operator!=(const BailoutId& other) const { return id_ != other.id_; }
private:
static const int kNoneId = -1;
// Using 0 could disguise errors.
static const int kFunctionEntryId = 2;
// This AST id identifies the point after the declarations have been visited.
// We need it to capture the environment effects of declarations that emit
// code (function declarations).
static const int kDeclarationsId = 3;
// Every FunctionState starts with this id.
static const int kFirstUsableId = 4;
// Every compiled stub starts with this id.
static const int kStubEntryId = 5;
int id_;
};
template <class C>
class ContainerPointerWrapper {
public:
typedef typename C::iterator iterator;
typedef typename C::reverse_iterator reverse_iterator;
explicit ContainerPointerWrapper(C* container) : container_(container) {}
iterator begin() { return container_->begin(); }
iterator end() { return container_->end(); }
reverse_iterator rbegin() { return container_->rbegin(); }
reverse_iterator rend() { return container_->rend(); }
private:
C* container_;
};
// ----------------------------------------------------------------------------
// I/O support.
#if __GNUC__ >= 4
// On gcc we can ask the compiler to check the types of %d-style format
// specifiers and their associated arguments. TODO(erikcorry) fix this
// so it works on MacOSX.
#if defined(__MACH__) && defined(__APPLE__)
#define PRINTF_CHECKING
#define FPRINTF_CHECKING
#define PRINTF_METHOD_CHECKING
#define FPRINTF_METHOD_CHECKING
#else // MacOsX.
#define PRINTF_CHECKING __attribute__ ((format (printf, 1, 2)))
#define FPRINTF_CHECKING __attribute__ ((format (printf, 2, 3)))
#define PRINTF_METHOD_CHECKING __attribute__ ((format (printf, 2, 3)))
#define FPRINTF_METHOD_CHECKING __attribute__ ((format (printf, 3, 4)))
#endif
#else
#define PRINTF_CHECKING
#define FPRINTF_CHECKING
#define PRINTF_METHOD_CHECKING
#define FPRINTF_METHOD_CHECKING
#endif
// Our version of printf().
void PRINTF_CHECKING PrintF(const char* format, ...);
void FPRINTF_CHECKING PrintF(FILE* out, const char* format, ...);
// Prepends the current process ID to the output.
void PRINTF_CHECKING PrintPID(const char* format, ...);
// Safe formatting print. Ensures that str is always null-terminated.
// Returns the number of chars written, or -1 if output was truncated.
int FPRINTF_CHECKING SNPrintF(Vector<char> str, const char* format, ...);
int VSNPrintF(Vector<char> str, const char* format, va_list args);
void StrNCpy(Vector<char> dest, const char* src, size_t n);
// Our version of fflush.
void Flush(FILE* out);
inline void Flush() {
Flush(stdout);
}
// Read a line of characters after printing the prompt to stdout. The resulting
// char* needs to be disposed off with DeleteArray by the caller.
char* ReadLine(const char* prompt);
// Read and return the raw bytes in a file. the size of the buffer is returned
// in size.
// The returned buffer must be freed by the caller.
byte* ReadBytes(const char* filename, int* size, bool verbose = true);
// Append size chars from str to the file given by filename.
// The file is overwritten. Returns the number of chars written.
int AppendChars(const char* filename,
const char* str,
int size,
bool verbose = true);
// Write size chars from str to the file given by filename.
// The file is overwritten. Returns the number of chars written.
int WriteChars(const char* filename,
const char* str,
int size,
bool verbose = true);
// Write size bytes to the file given by filename.
// The file is overwritten. Returns the number of bytes written.
int WriteBytes(const char* filename,
const byte* bytes,
int size,
bool verbose = true);
// Write the C code
// const char* <varname> = "<str>";
// const int <varname>_len = <len>;
// to the file given by filename. Only the first len chars are written.
int WriteAsCFile(const char* filename, const char* varname,
const char* str, int size, bool verbose = true);
// ----------------------------------------------------------------------------
// Data structures
template <typename T>
inline Vector< Handle<Object> > HandleVector(v8::internal::Handle<T>* elms,
int length) {
return Vector< Handle<Object> >(
reinterpret_cast<v8::internal::Handle<Object>*>(elms), length);
}
// ----------------------------------------------------------------------------
// Memory
// Copies words from |src| to |dst|. The data spans must not overlap.
template <typename T>
inline void CopyWords(T* dst, const T* src, size_t num_words) {
STATIC_ASSERT(sizeof(T) == kPointerSize);
// TODO(mvstanton): disabled because mac builds are bogus failing on this
// assert. They are doing a signed comparison. Investigate in
// the morning.
// DCHECK(Min(dst, const_cast<T*>(src)) + num_words <=
// Max(dst, const_cast<T*>(src)));
DCHECK(num_words > 0);
// Use block copying MemCopy if the segment we're copying is
// enough to justify the extra call/setup overhead.
static const size_t kBlockCopyLimit = 16;
if (num_words < kBlockCopyLimit) {
do {
num_words--;
*dst++ = *src++;
} while (num_words > 0);
} else {
MemCopy(dst, src, num_words * kPointerSize);
}
}
// Copies words from |src| to |dst|. No restrictions.
template <typename T>
inline void MoveWords(T* dst, const T* src, size_t num_words) {
STATIC_ASSERT(sizeof(T) == kPointerSize);
DCHECK(num_words > 0);
// Use block copying MemCopy if the segment we're copying is
// enough to justify the extra call/setup overhead.
static const size_t kBlockCopyLimit = 16;
if (num_words < kBlockCopyLimit &&
((dst < src) || (dst >= (src + num_words * kPointerSize)))) {
T* end = dst + num_words;
do {
num_words--;
*dst++ = *src++;
} while (num_words > 0);
} else {
MemMove(dst, src, num_words * kPointerSize);
}
}
// Copies data from |src| to |dst|. The data spans must not overlap.
template <typename T>
inline void CopyBytes(T* dst, const T* src, size_t num_bytes) {
STATIC_ASSERT(sizeof(T) == 1);
DCHECK(Min(dst, const_cast<T*>(src)) + num_bytes <=
Max(dst, const_cast<T*>(src)));
if (num_bytes == 0) return;
// Use block copying MemCopy if the segment we're copying is
// enough to justify the extra call/setup overhead.
static const int kBlockCopyLimit = kMinComplexMemCopy;
if (num_bytes < static_cast<size_t>(kBlockCopyLimit)) {
do {
num_bytes--;
*dst++ = *src++;
} while (num_bytes > 0);
} else {
MemCopy(dst, src, num_bytes);
}
}
template <typename T, typename U>
inline void MemsetPointer(T** dest, U* value, int counter) {
#ifdef DEBUG
T* a = NULL;
U* b = NULL;
a = b; // Fake assignment to check assignability.
USE(a);
#endif // DEBUG
#if V8_HOST_ARCH_IA32
#define STOS "stosl"
#elif V8_HOST_ARCH_X64
#if V8_HOST_ARCH_32_BIT
#define STOS "addr32 stosl"
#else
#define STOS "stosq"
#endif
#endif
#if defined(__native_client__)
// This STOS sequence does not validate for x86_64 Native Client.
// Here we #undef STOS to force use of the slower C version.
// TODO(bradchen): Profile V8 and implement a faster REP STOS
// here if the profile indicates it matters.
#undef STOS
#endif
#if defined(MEMORY_SANITIZER)
// MemorySanitizer does not understand inline assembly.
#undef STOS
#endif
#if defined(__GNUC__) && defined(STOS)
asm volatile(
"cld;"
"rep ; " STOS
: "+&c" (counter), "+&D" (dest)
: "a" (value)
: "memory", "cc");
#else
for (int i = 0; i < counter; i++) {
dest[i] = value;
}
#endif
#undef STOS
}
// Simple support to read a file into a 0-terminated C-string.
// The returned buffer must be freed by the caller.
// On return, *exits tells whether the file existed.
Vector<const char> ReadFile(const char* filename,
bool* exists,
bool verbose = true);
Vector<const char> ReadFile(FILE* file,
bool* exists,
bool verbose = true);
template <typename sourcechar, typename sinkchar>
INLINE(static void CopyCharsUnsigned(sinkchar* dest,
const sourcechar* src,
int chars));
#if defined(V8_HOST_ARCH_ARM)
INLINE(void CopyCharsUnsigned(uint8_t* dest, const uint8_t* src, int chars));
INLINE(void CopyCharsUnsigned(uint16_t* dest, const uint8_t* src, int chars));
INLINE(void CopyCharsUnsigned(uint16_t* dest, const uint16_t* src, int chars));
#elif defined(V8_HOST_ARCH_MIPS)
INLINE(void CopyCharsUnsigned(uint8_t* dest, const uint8_t* src, int chars));
INLINE(void CopyCharsUnsigned(uint16_t* dest, const uint16_t* src, int chars));
#endif
// Copy from 8bit/16bit chars to 8bit/16bit chars.
template <typename sourcechar, typename sinkchar>
INLINE(void CopyChars(sinkchar* dest, const sourcechar* src, int chars));
template<typename sourcechar, typename sinkchar>
void CopyChars(sinkchar* dest, const sourcechar* src, int chars) {
DCHECK(sizeof(sourcechar) <= 2);
DCHECK(sizeof(sinkchar) <= 2);
if (sizeof(sinkchar) == 1) {
if (sizeof(sourcechar) == 1) {
CopyCharsUnsigned(reinterpret_cast<uint8_t*>(dest),
reinterpret_cast<const uint8_t*>(src),
chars);
} else {
CopyCharsUnsigned(reinterpret_cast<uint8_t*>(dest),
reinterpret_cast<const uint16_t*>(src),
chars);
}
} else {
if (sizeof(sourcechar) == 1) {
CopyCharsUnsigned(reinterpret_cast<uint16_t*>(dest),
reinterpret_cast<const uint8_t*>(src),
chars);
} else {
CopyCharsUnsigned(reinterpret_cast<uint16_t*>(dest),
reinterpret_cast<const uint16_t*>(src),
chars);
}
}
}
template <typename sourcechar, typename sinkchar>
void CopyCharsUnsigned(sinkchar* dest, const sourcechar* src, int chars) {
sinkchar* limit = dest + chars;
if ((sizeof(*dest) == sizeof(*src)) &&
(chars >= static_cast<int>(kMinComplexMemCopy / sizeof(*dest)))) {
MemCopy(dest, src, chars * sizeof(*dest));
} else {
while (dest < limit) *dest++ = static_cast<sinkchar>(*src++);
}
}
#if defined(V8_HOST_ARCH_ARM)
void CopyCharsUnsigned(uint8_t* dest, const uint8_t* src, int chars) {
switch (static_cast<unsigned>(chars)) {
case 0:
break;
case 1:
*dest = *src;
break;
case 2:
memcpy(dest, src, 2);
break;
case 3:
memcpy(dest, src, 3);
break;
case 4:
memcpy(dest, src, 4);
break;
case 5:
memcpy(dest, src, 5);
break;
case 6:
memcpy(dest, src, 6);
break;
case 7:
memcpy(dest, src, 7);
break;
case 8:
memcpy(dest, src, 8);
break;
case 9:
memcpy(dest, src, 9);
break;
case 10:
memcpy(dest, src, 10);
break;
case 11:
memcpy(dest, src, 11);
break;
case 12:
memcpy(dest, src, 12);
break;
case 13:
memcpy(dest, src, 13);
break;
case 14:
memcpy(dest, src, 14);
break;
case 15:
memcpy(dest, src, 15);
break;
default:
MemCopy(dest, src, chars);
break;
}
}
void CopyCharsUnsigned(uint16_t* dest, const uint8_t* src, int chars) {
if (chars >= kMinComplexConvertMemCopy) {
MemCopyUint16Uint8(dest, src, chars);
} else {
MemCopyUint16Uint8Wrapper(dest, src, chars);
}
}
void CopyCharsUnsigned(uint16_t* dest, const uint16_t* src, int chars) {
switch (static_cast<unsigned>(chars)) {
case 0:
break;
case 1:
*dest = *src;
break;
case 2:
memcpy(dest, src, 4);
break;
case 3:
memcpy(dest, src, 6);
break;
case 4:
memcpy(dest, src, 8);
break;
case 5:
memcpy(dest, src, 10);
break;
case 6:
memcpy(dest, src, 12);
break;
case 7:
memcpy(dest, src, 14);
break;
default:
MemCopy(dest, src, chars * sizeof(*dest));
break;
}
}
#elif defined(V8_HOST_ARCH_MIPS)
void CopyCharsUnsigned(uint8_t* dest, const uint8_t* src, int chars) {
if (chars < kMinComplexMemCopy) {
memcpy(dest, src, chars);
} else {
MemCopy(dest, src, chars);
}
}
void CopyCharsUnsigned(uint16_t* dest, const uint16_t* src, int chars) {
if (chars < kMinComplexMemCopy) {
memcpy(dest, src, chars * sizeof(*dest));
} else {
MemCopy(dest, src, chars * sizeof(*dest));
}
}
#endif
class StringBuilder : public SimpleStringBuilder {
public:
explicit StringBuilder(int size) : SimpleStringBuilder(size) { }
StringBuilder(char* buffer, int size) : SimpleStringBuilder(buffer, size) { }
// Add formatted contents to the builder just like printf().
void AddFormatted(const char* format, ...);
// Add formatted contents like printf based on a va_list.
void AddFormattedList(const char* format, va_list list);
private:
DISALLOW_IMPLICIT_CONSTRUCTORS(StringBuilder);
};
bool DoubleToBoolean(double d);
template <typename Stream>
bool StringToArrayIndex(Stream* stream, uint32_t* index) {
uint16_t ch = stream->GetNext();
// If the string begins with a '0' character, it must only consist
// of it to be a legal array index.
if (ch == '0') {
*index = 0;
return !stream->HasMore();
}
// Convert string to uint32 array index; character by character.
int d = ch - '0';
if (d < 0 || d > 9) return false;
uint32_t result = d;
while (stream->HasMore()) {
d = stream->GetNext() - '0';
if (d < 0 || d > 9) return false;
// Check that the new result is below the 32 bit limit.
if (result > 429496729U - ((d > 5) ? 1 : 0)) return false;
result = (result * 10) + d;
}
*index = result;
return true;
}
// Returns current value of top of the stack. Works correctly with ASAN.
DISABLE_ASAN
inline uintptr_t GetCurrentStackPosition() {
// Takes the address of the limit variable in order to find out where
// the top of stack is right now.
uintptr_t limit = reinterpret_cast<uintptr_t>(&limit);
return limit;
}
} // namespace internal
} // namespace v8
#endif // V8_UTILS_H_