| // 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_UTILS_H_ |
| #define V8_UTILS_UTILS_H_ |
| |
| #include <limits.h> |
| #include <stdlib.h> |
| #include <string.h> |
| #include <cmath> |
| #include <string> |
| #include <type_traits> |
| |
| #include "include/v8.h" |
| #include "src/base/bits.h" |
| #include "src/base/compiler-specific.h" |
| #include "src/base/logging.h" |
| #include "src/base/macros.h" |
| #include "src/base/platform/platform.h" |
| #include "src/base/v8-fallthrough.h" |
| #include "src/common/globals.h" |
| #include "src/third_party/siphash/halfsiphash.h" |
| #include "src/utils/allocation.h" |
| #include "src/utils/vector.h" |
| |
| #if defined(V8_OS_AIX) |
| #include <fenv.h> // NOLINT(build/c++11) |
| #endif |
| |
| namespace v8 { |
| namespace internal { |
| |
| // ---------------------------------------------------------------------------- |
| // General helper functions |
| |
| // Returns the value (0 .. 15) of a hexadecimal character c. |
| // If c is not a legal hexadecimal character, returns a value < 0. |
| inline int HexValue(uc32 c) { |
| c -= '0'; |
| if (static_cast<unsigned>(c) <= 9) return c; |
| c = (c | 0x20) - ('a' - '0'); // detect 0x11..0x16 and 0x31..0x36. |
| if (static_cast<unsigned>(c) <= 5) return c + 10; |
| return -1; |
| } |
| |
| inline char HexCharOfValue(int value) { |
| DCHECK(0 <= value && value <= 16); |
| if (value < 10) return value + '0'; |
| return value - 10 + 'A'; |
| } |
| |
| inline int BoolToInt(bool b) { return b ? 1 : 0; } |
| |
| // Checks if value is in range [lower_limit, higher_limit] using a single |
| // branch. |
| template <typename T, typename U> |
| inline constexpr bool IsInRange(T value, U lower_limit, U higher_limit) { |
| #if V8_CAN_HAVE_DCHECK_IN_CONSTEXPR |
| DCHECK(lower_limit <= higher_limit); |
| #endif |
| STATIC_ASSERT(sizeof(U) <= sizeof(T)); |
| using unsigned_T = typename std::make_unsigned<T>::type; |
| // Use static_cast to support enum classes. |
| return static_cast<unsigned_T>(static_cast<unsigned_T>(value) - |
| static_cast<unsigned_T>(lower_limit)) <= |
| static_cast<unsigned_T>(static_cast<unsigned_T>(higher_limit) - |
| static_cast<unsigned_T>(lower_limit)); |
| } |
| |
| // Checks if [index, index+length) is in range [0, max). Note that this check |
| // works even if {index+length} would wrap around. |
| inline constexpr bool IsInBounds(size_t index, size_t length, size_t max) { |
| return length <= max && index <= (max - length); |
| } |
| |
| // Checks if [index, index+length) is in range [0, max). If not, {length} is |
| // clamped to its valid range. Note that this check works even if |
| // {index+length} would wrap around. |
| template <typename T> |
| inline bool ClampToBounds(T index, T* length, T max) { |
| if (index > max) { |
| *length = 0; |
| return false; |
| } |
| T avail = max - index; |
| bool oob = *length > avail; |
| if (oob) *length = avail; |
| return !oob; |
| } |
| |
| // X must be a power of 2. Returns the number of trailing zeros. |
| template <typename T, |
| typename = typename std::enable_if<std::is_integral<T>::value>::type> |
| inline int WhichPowerOf2(T x) { |
| DCHECK(base::bits::IsPowerOfTwo(x)); |
| int bits = 0; |
| #ifdef DEBUG |
| const T original_x = x; |
| #endif |
| constexpr int max_bits = sizeof(T) * 8; |
| static_assert(max_bits <= 64, "integral types are not bigger than 64 bits"); |
| // Avoid shifting by more than the bit width of x to avoid compiler warnings. |
| #define CHECK_BIGGER(s) \ |
| if (max_bits > s && x >= T{1} << (max_bits > s ? s : 0)) { \ |
| bits += s; \ |
| x >>= max_bits > s ? s : 0; \ |
| } |
| CHECK_BIGGER(32) |
| CHECK_BIGGER(16) |
| CHECK_BIGGER(8) |
| CHECK_BIGGER(4) |
| #undef CHECK_BIGGER |
| switch (x) { |
| default: |
| UNREACHABLE(); |
| case 8: |
| bits++; |
| V8_FALLTHROUGH; |
| case 4: |
| bits++; |
| V8_FALLTHROUGH; |
| case 2: |
| bits++; |
| V8_FALLTHROUGH; |
| case 1: |
| break; |
| } |
| DCHECK_EQ(T{1} << bits, original_x); |
| return bits; |
| } |
| |
| 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]; |
| } |
| |
| template <typename T> |
| static T ArithmeticShiftRight(T x, int shift) { |
| DCHECK_LE(0, shift); |
| if (x < 0) { |
| // Right shift of signed values is implementation defined. Simulate a |
| // true arithmetic right shift by adding leading sign bits. |
| using UnsignedT = typename std::make_unsigned<T>::type; |
| UnsignedT mask = ~(static_cast<UnsignedT>(~0) >> shift); |
| return (static_cast<UnsignedT>(x) >> shift) | mask; |
| } else { |
| return x >> shift; |
| } |
| } |
| |
| 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; |
| } |
| |
| // 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)); |
| } |
| |
| // Returns the maximum of the two parameters. |
| template <typename T> |
| constexpr T Max(T a, T b) { |
| return a < b ? b : a; |
| } |
| |
| // Returns the minimum of the two parameters. |
| template <typename T> |
| constexpr T Min(T a, T b) { |
| return a < b ? a : b; |
| } |
| |
| // Returns the maximum of the two parameters according to JavaScript semantics. |
| template <typename T> |
| T JSMax(T x, T y) { |
| if (std::isnan(x)) return x; |
| if (std::isnan(y)) return y; |
| if (std::signbit(x) < std::signbit(y)) return x; |
| return x > y ? x : y; |
| } |
| |
| // Returns the maximum of the two parameters according to JavaScript semantics. |
| template <typename T> |
| T JSMin(T x, T y) { |
| if (std::isnan(x)) return x; |
| if (std::isnan(y)) return y; |
| if (std::signbit(x) < std::signbit(y)) return y; |
| return x > y ? y : x; |
| } |
| |
| // Returns the absolute value of its argument. |
| template <typename T, |
| typename = typename std::enable_if<std::is_signed<T>::value>::type> |
| typename std::make_unsigned<T>::type Abs(T a) { |
| // This is a branch-free implementation of the absolute value function and is |
| // described in Warren's "Hacker's Delight", chapter 2. It avoids undefined |
| // behavior with the arithmetic negation operation on signed values as well. |
| using unsignedT = typename std::make_unsigned<T>::type; |
| unsignedT x = static_cast<unsignedT>(a); |
| unsignedT y = static_cast<unsignedT>(a >> (sizeof(T) * 8 - 1)); |
| return (x ^ y) - y; |
| } |
| |
| // Returns the negative absolute value of its argument. |
| template <typename T, |
| typename = typename std::enable_if<std::is_signed<T>::value>::type> |
| T Nabs(T a) { |
| return a < 0 ? a : -a; |
| } |
| |
| inline double Modulo(double x, double y) { |
| #if defined(V8_OS_WIN) |
| // Workaround MS fmod bugs. ECMA-262 says: |
| // dividend is finite and divisor is an infinity => result equals dividend |
| // dividend is a zero and divisor is nonzero finite => result equals dividend |
| if (!(std::isfinite(x) && (!std::isfinite(y) && !std::isnan(y))) && |
| !(x == 0 && (y != 0 && std::isfinite(y)))) { |
| double result = fmod(x, y); |
| // Workaround MS bug in VS CRT in some OS versions, https://crbug.com/915045 |
| // fmod(-17, +/-1) should equal -0.0 but now returns 0.0. |
| if (x < 0 && result == 0) result = -0.0; |
| x = result; |
| } |
| return x; |
| #elif defined(V8_OS_AIX) |
| // AIX raises an underflow exception for (Number.MIN_VALUE % Number.MAX_VALUE) |
| feclearexcept(FE_ALL_EXCEPT); |
| double result = std::fmod(x, y); |
| int exception = fetestexcept(FE_UNDERFLOW); |
| return (exception ? x : result); |
| #else |
| return std::fmod(x, y); |
| #endif |
| } |
| |
| template <typename T> |
| T SaturateAdd(T a, T b) { |
| if (std::is_signed<T>::value) { |
| if (a > 0 && b > 0) { |
| if (a > std::numeric_limits<T>::max() - b) { |
| return std::numeric_limits<T>::max(); |
| } |
| } else if (a < 0 && b < 0) { |
| if (a < std::numeric_limits<T>::min() - b) { |
| return std::numeric_limits<T>::min(); |
| } |
| } |
| } else { |
| CHECK(std::is_unsigned<T>::value); |
| if (a > std::numeric_limits<T>::max() - b) { |
| return std::numeric_limits<T>::max(); |
| } |
| } |
| return a + b; |
| } |
| |
| template <typename T> |
| T SaturateSub(T a, T b) { |
| if (std::is_signed<T>::value) { |
| if (a >= 0 && b < 0) { |
| if (a > std::numeric_limits<T>::max() + b) { |
| return std::numeric_limits<T>::max(); |
| } |
| } else if (a < 0 && b > 0) { |
| if (a < std::numeric_limits<T>::min() + b) { |
| return std::numeric_limits<T>::min(); |
| } |
| } |
| } else { |
| CHECK(std::is_unsigned<T>::value); |
| if (a < b) { |
| return static_cast<T>(0); |
| } |
| } |
| return a - b; |
| } |
| |
| // ---------------------------------------------------------------------------- |
| // BitField is a help template for encoding and decode bitfield with |
| // unsigned content. |
| |
| template <class T, int shift, int size, class U = uint32_t> |
| class BitField { |
| public: |
| STATIC_ASSERT(std::is_unsigned<U>::value); |
| STATIC_ASSERT(shift < 8 * sizeof(U)); // Otherwise shifts by {shift} are UB. |
| STATIC_ASSERT(size < 8 * sizeof(U)); // Otherwise shifts by {size} are UB. |
| STATIC_ASSERT(shift + size <= 8 * sizeof(U)); |
| |
| using FieldType = T; |
| |
| // 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 constexpr U kShift = shift; |
| static constexpr U kSize = size; |
| static constexpr U kMask = ((U{1} << kShift) << kSize) - (U{1} << kShift); |
| static constexpr U kNext = kShift + kSize; |
| static constexpr U kNumValues = U{1} << kSize; |
| |
| // Value for the field with all bits set. |
| static constexpr T kMax = static_cast<T>(kNumValues - 1); |
| |
| // Tells whether the provided value fits into the bit field. |
| static constexpr 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 constexpr U encode(T value) { |
| #if V8_CAN_HAVE_DCHECK_IN_CONSTEXPR |
| DCHECK(is_valid(value)); |
| #endif |
| return static_cast<U>(value) << kShift; |
| } |
| |
| // Returns a type U with the bit field value updated. |
| static constexpr U update(U previous, T value) { |
| return (previous & ~kMask) | encode(value); |
| } |
| |
| // Extracts the bit field from the value. |
| static constexpr T decode(U value) { |
| return static_cast<T>((value & kMask) >> kShift); |
| } |
| }; |
| |
| template <class T, int shift, int size> |
| using BitField8 = BitField<T, shift, size, uint8_t>; |
| |
| template <class T, int shift, int size> |
| using BitField16 = BitField<T, shift, size, uint16_t>; |
| |
| template <class T, int shift, int size> |
| using BitField64 = BitField<T, shift, size, uint64_t>; |
| |
| // Helper macros for defining a contiguous sequence of bit fields. Example: |
| // (backslashes at the ends of respective lines of this multi-line macro |
| // definition are omitted here to please the compiler) |
| // |
| // #define MAP_BIT_FIELD1(V, _) |
| // V(IsAbcBit, bool, 1, _) |
| // V(IsBcdBit, bool, 1, _) |
| // V(CdeBits, int, 5, _) |
| // V(DefBits, MutableMode, 1, _) |
| // |
| // DEFINE_BIT_FIELDS(MAP_BIT_FIELD1) |
| // or |
| // DEFINE_BIT_FIELDS_64(MAP_BIT_FIELD1) |
| // |
| #define DEFINE_BIT_FIELD_RANGE_TYPE(Name, Type, Size, _) \ |
| k##Name##Start, k##Name##End = k##Name##Start + Size - 1, |
| |
| #define DEFINE_BIT_RANGES(LIST_MACRO) \ |
| struct LIST_MACRO##_Ranges { \ |
| enum { LIST_MACRO(DEFINE_BIT_FIELD_RANGE_TYPE, _) kBitsCount }; \ |
| }; |
| |
| #define DEFINE_BIT_FIELD_TYPE(Name, Type, Size, RangesName) \ |
| using Name = BitField<Type, RangesName::k##Name##Start, Size>; |
| |
| #define DEFINE_BIT_FIELD_64_TYPE(Name, Type, Size, RangesName) \ |
| using Name = BitField64<Type, RangesName::k##Name##Start, Size>; |
| |
| #define DEFINE_BIT_FIELDS(LIST_MACRO) \ |
| DEFINE_BIT_RANGES(LIST_MACRO) \ |
| LIST_MACRO(DEFINE_BIT_FIELD_TYPE, LIST_MACRO##_Ranges) |
| |
| #define DEFINE_BIT_FIELDS_64(LIST_MACRO) \ |
| DEFINE_BIT_RANGES(LIST_MACRO) \ |
| LIST_MACRO(DEFINE_BIT_FIELD_64_TYPE, LIST_MACRO##_Ranges) |
| |
| // ---------------------------------------------------------------------------- |
| // BitSetComputer is a help template for encoding and decoding information for |
| // a variable number of items in an array. |
| // |
| // To encode boolean data in a smi array you would use: |
| // using BoolComputer = BitSetComputer<bool, 1, kSmiValueSize, uint32_t>; |
| // |
| template <class T, int kBitsPerItem, int kBitsPerWord, class U> |
| class BitSetComputer { |
| public: |
| static const int kItemsPerWord = kBitsPerWord / kBitsPerItem; |
| static const int kMask = (1 << kBitsPerItem) - 1; |
| |
| // The number of array elements required to embed T information for each item. |
| static int word_count(int items) { |
| if (items == 0) return 0; |
| return (items - 1) / kItemsPerWord + 1; |
| } |
| |
| // The array index to look at for item. |
| static int index(int base_index, int item) { |
| return base_index + item / kItemsPerWord; |
| } |
| |
| // Extract T data for a given item from data. |
| static T decode(U data, int item) { |
| return static_cast<T>((data >> shift(item)) & kMask); |
| } |
| |
| // Return the encoding for a store of value for item in previous. |
| static U encode(U previous, int item, T value) { |
| int shift_value = shift(item); |
| int set_bits = (static_cast<int>(value) << shift_value); |
| return (previous & ~(kMask << shift_value)) | set_bits; |
| } |
| |
| static int shift(int item) { return (item % kItemsPerWord) * kBitsPerItem; } |
| }; |
| |
| // Helper macros for defining a contiguous sequence of field offset constants. |
| // Example: (backslashes at the ends of respective lines of this multi-line |
| // macro definition are omitted here to please the compiler) |
| // |
| // #define MAP_FIELDS(V) |
| // V(kField1Offset, kTaggedSize) |
| // V(kField2Offset, kIntSize) |
| // V(kField3Offset, kIntSize) |
| // V(kField4Offset, kSystemPointerSize) |
| // V(kSize, 0) |
| // |
| // DEFINE_FIELD_OFFSET_CONSTANTS(HeapObject::kHeaderSize, MAP_FIELDS) |
| // |
| #define DEFINE_ONE_FIELD_OFFSET(Name, Size) Name, Name##End = Name + (Size)-1, |
| |
| #define DEFINE_FIELD_OFFSET_CONSTANTS(StartOffset, LIST_MACRO) \ |
| enum { \ |
| LIST_MACRO##_StartOffset = StartOffset - 1, \ |
| LIST_MACRO(DEFINE_ONE_FIELD_OFFSET) \ |
| }; |
| |
| // Size of the field defined by DEFINE_FIELD_OFFSET_CONSTANTS |
| #define FIELD_SIZE(Name) (Name##End + 1 - Name) |
| |
| // Compare two offsets with static cast |
| #define STATIC_ASSERT_FIELD_OFFSETS_EQUAL(Offset1, Offset2) \ |
| STATIC_ASSERT(static_cast<int>(Offset1) == Offset2) |
| // ---------------------------------------------------------------------------- |
| // Hash function. |
| |
| static const uint64_t kZeroHashSeed = 0; |
| |
| // Thomas Wang, Integer Hash Functions. |
| // http://www.concentric.net/~Ttwang/tech/inthash.htm` |
| inline uint32_t ComputeUnseededHash(uint32_t key) { |
| uint32_t hash = key; |
| 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 & 0x3fffffff; |
| } |
| |
| 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 & 0x3fffffff); |
| } |
| |
| inline uint32_t ComputeSeededHash(uint32_t key, uint64_t seed) { |
| #ifdef V8_USE_SIPHASH |
| return halfsiphash(key, seed); |
| #else |
| return ComputeLongHash(static_cast<uint64_t>(key) ^ seed); |
| #endif // V8_USE_SIPHASH |
| } |
| |
| inline uint32_t ComputePointerHash(void* ptr) { |
| return ComputeUnseededHash( |
| static_cast<uint32_t>(reinterpret_cast<intptr_t>(ptr))); |
| } |
| |
| inline uint32_t ComputeAddressHash(Address address) { |
| return ComputeUnseededHash(static_cast<uint32_t>(address & 0xFFFFFFFFul)); |
| } |
| |
| // ---------------------------------------------------------------------------- |
| // Miscellaneous |
| |
| // Memory offset for lower and higher bits in a 64 bit integer. |
| #if defined(V8_TARGET_LITTLE_ENDIAN) |
| static const int kInt64LowerHalfMemoryOffset = 0; |
| static const int kInt64UpperHalfMemoryOffset = 4; |
| #elif defined(V8_TARGET_BIG_ENDIAN) |
| static const int kInt64LowerHalfMemoryOffset = 4; |
| static const int kInt64UpperHalfMemoryOffset = 0; |
| #endif // V8_TARGET_LITTLE_ENDIAN |
| |
| // 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_ = nullptr; |
| instance_ = nullptr; |
| } |
| |
| 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() = default; |
| |
| bool is_set() const { return pointer_ != nullptr; } |
| |
| T* get() const { |
| DCHECK_NOT_NULL(pointer_); |
| return pointer_; |
| } |
| |
| void set(T* value) { |
| DCHECK(pointer_ == nullptr && value != nullptr); |
| pointer_ = value; |
| } |
| |
| SetOncePointer& operator=(T* value) { |
| set(value); |
| return *this; |
| } |
| |
| bool operator==(std::nullptr_t) const { return pointer_ == nullptr; } |
| bool operator!=(std::nullptr_t) const { return pointer_ != nullptr; } |
| |
| private: |
| T* pointer_ = nullptr; |
| }; |
| |
| // Compare 8bit/16bit chars to 8bit/16bit chars. |
| template <typename lchar, typename rchar> |
| inline int CompareCharsUnsigned(const lchar* lhs, const rchar* rhs, |
| size_t 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, size_t chars) { |
| DCHECK_LE(sizeof(lchar), 2); |
| DCHECK_LE(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_LE(exponent, 9); |
| DCHECK_GE(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_NE(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 0-terminated 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); |
| }; |
| |
| // 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)); |
| } |
| |
| // clang-format off |
| #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) |
| // clang-format on |
| |
| #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 |
| |
| // clang-format off |
| #define INT_0_TO_127_LIST(V) \ |
| V(0) 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) V(64) V(65) V(66) V(67) V(68) V(69) \ |
| V(70) V(71) V(72) V(73) V(74) V(75) V(76) V(77) V(78) V(79) \ |
| V(80) V(81) V(82) V(83) V(84) V(85) V(86) V(87) V(88) V(89) \ |
| V(90) V(91) V(92) V(93) V(94) V(95) V(96) V(97) V(98) V(99) \ |
| V(100) V(101) V(102) V(103) V(104) V(105) V(106) V(107) V(108) V(109) \ |
| V(110) V(111) V(112) V(113) V(114) V(115) V(116) V(117) V(118) V(119) \ |
| V(120) V(121) V(122) V(123) V(124) V(125) V(126) V(127) |
| // clang-format on |
| |
| class FeedbackSlot { |
| public: |
| FeedbackSlot() : id_(kInvalidSlot) {} |
| explicit FeedbackSlot(int id) : id_(id) {} |
| |
| int ToInt() const { return id_; } |
| |
| static FeedbackSlot Invalid() { return FeedbackSlot(); } |
| bool IsInvalid() const { return id_ == kInvalidSlot; } |
| |
| bool operator==(FeedbackSlot that) const { return this->id_ == that.id_; } |
| bool operator!=(FeedbackSlot that) const { return !(*this == that); } |
| |
| friend size_t hash_value(FeedbackSlot slot) { return slot.ToInt(); } |
| V8_EXPORT_PRIVATE friend std::ostream& operator<<(std::ostream& os, |
| FeedbackSlot); |
| |
| private: |
| static const int kInvalidSlot = -1; |
| |
| int id_; |
| }; |
| |
| V8_EXPORT_PRIVATE std::ostream& operator<<(std::ostream& os, FeedbackSlot); |
| |
| class BailoutId { |
| public: |
| explicit BailoutId(int id) : id_(id) {} |
| int ToInt() const { return id_; } |
| |
| static BailoutId None() { return BailoutId(kNoneId); } |
| |
| // Special bailout id support for deopting into the {JSConstructStub} stub. |
| // The following hard-coded deoptimization points are supported by the stub: |
| // - {ConstructStubCreate} maps to {construct_stub_create_deopt_pc_offset}. |
| // - {ConstructStubInvoke} maps to {construct_stub_invoke_deopt_pc_offset}. |
| static BailoutId ConstructStubCreate() { return BailoutId(1); } |
| static BailoutId ConstructStubInvoke() { return BailoutId(2); } |
| bool IsValidForConstructStub() const { |
| return id_ == ConstructStubCreate().ToInt() || |
| id_ == ConstructStubInvoke().ToInt(); |
| } |
| |
| 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_; } |
| friend size_t hash_value(BailoutId); |
| V8_EXPORT_PRIVATE friend std::ostream& operator<<(std::ostream&, BailoutId); |
| |
| private: |
| friend class Builtins; |
| |
| static const int kNoneId = -1; |
| |
| // Using 0 could disguise errors. |
| // Builtin continuations bailout ids start here. If you need to add a |
| // non-builtin BailoutId, add it before this id so that this Id has the |
| // highest number. |
| static const int kFirstBuiltinContinuationId = 1; |
| |
| int id_; |
| }; |
| |
| // ---------------------------------------------------------------------------- |
| // I/O support. |
| |
| // Our version of printf(). |
| V8_EXPORT_PRIVATE void PRINTF_FORMAT(1, 2) PrintF(const char* format, ...); |
| void PRINTF_FORMAT(2, 3) PrintF(FILE* out, const char* format, ...); |
| |
| // Prepends the current process ID to the output. |
| void PRINTF_FORMAT(1, 2) PrintPID(const char* format, ...); |
| |
| // Prepends the current process ID and given isolate pointer to the output. |
| void PRINTF_FORMAT(2, 3) PrintIsolate(void* isolate, 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. |
| V8_EXPORT_PRIVATE int PRINTF_FORMAT(2, 3) |
| SNPrintF(Vector<char> str, const char* format, ...); |
| V8_EXPORT_PRIVATE int PRINTF_FORMAT(2, 0) |
| 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); |
| |
| // 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); |
| |
| // Simple support to read a file into std::string. |
| // On return, *exits tells whether the file existed. |
| V8_EXPORT_PRIVATE std::string ReadFile(const char* filename, bool* exists, |
| bool verbose = true); |
| V8_EXPORT_PRIVATE std::string ReadFile(FILE* file, bool* exists, |
| bool verbose = true); |
| |
| 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 PRINTF_FORMAT(2, 3) AddFormatted(const char* format, ...); |
| |
| // Add formatted contents like printf based on a va_list. |
| void PRINTF_FORMAT(2, 0) AddFormattedList(const char* format, va_list list); |
| |
| private: |
| DISALLOW_IMPLICIT_CONSTRUCTORS(StringBuilder); |
| }; |
| |
| bool DoubleToBoolean(double d); |
| |
| template <typename Char> |
| bool TryAddIndexChar(uint32_t* index, Char c); |
| |
| template <typename Stream> |
| bool StringToArrayIndex(Stream* stream, uint32_t* index); |
| |
| // Returns the current stack top. Works correctly with ASAN and SafeStack. |
| // GetCurrentStackPosition() should not be inlined, because it works on stack |
| // frames if it were inlined into a function with a huge stack frame it would |
| // return an address significantly above the actual current stack position. |
| V8_EXPORT_PRIVATE V8_NOINLINE uintptr_t GetCurrentStackPosition(); |
| |
| static inline uint16_t ByteReverse16(uint16_t value) { |
| #if V8_HAS_BUILTIN_BSWAP16 |
| return __builtin_bswap16(value); |
| #else |
| return value << 8 | (value >> 8 & 0x00FF); |
| #endif |
| } |
| |
| static inline uint32_t ByteReverse32(uint32_t value) { |
| #if V8_HAS_BUILTIN_BSWAP32 |
| return __builtin_bswap32(value); |
| #else |
| return value << 24 | ((value << 8) & 0x00FF0000) | |
| ((value >> 8) & 0x0000FF00) | ((value >> 24) & 0x00000FF); |
| #endif |
| } |
| |
| static inline uint64_t ByteReverse64(uint64_t value) { |
| #if V8_HAS_BUILTIN_BSWAP64 |
| return __builtin_bswap64(value); |
| #else |
| size_t bits_of_v = sizeof(value) * kBitsPerByte; |
| return value << (bits_of_v - 8) | |
| ((value << (bits_of_v - 24)) & 0x00FF000000000000) | |
| ((value << (bits_of_v - 40)) & 0x0000FF0000000000) | |
| ((value << (bits_of_v - 56)) & 0x000000FF00000000) | |
| ((value >> (bits_of_v - 56)) & 0x00000000FF000000) | |
| ((value >> (bits_of_v - 40)) & 0x0000000000FF0000) | |
| ((value >> (bits_of_v - 24)) & 0x000000000000FF00) | |
| ((value >> (bits_of_v - 8)) & 0x00000000000000FF); |
| #endif |
| } |
| |
| template <typename V> |
| static inline V ByteReverse(V value) { |
| size_t size_of_v = sizeof(value); |
| switch (size_of_v) { |
| case 1: |
| return value; |
| case 2: |
| return static_cast<V>(ByteReverse16(static_cast<uint16_t>(value))); |
| case 4: |
| return static_cast<V>(ByteReverse32(static_cast<uint32_t>(value))); |
| case 8: |
| return static_cast<V>(ByteReverse64(static_cast<uint64_t>(value))); |
| default: |
| UNREACHABLE(); |
| } |
| } |
| |
| V8_EXPORT_PRIVATE bool PassesFilter(Vector<const char> name, |
| Vector<const char> filter); |
| |
| // Zap the specified area with a specific byte pattern. This currently defaults |
| // to int3 on x64 and ia32. On other architectures this will produce unspecified |
| // instruction sequences. |
| // TODO(jgruber): Better support for other architectures. |
| V8_INLINE void ZapCode(Address addr, size_t size_in_bytes) { |
| static constexpr int kZapByte = 0xCC; |
| std::memset(reinterpret_cast<void*>(addr), kZapByte, size_in_bytes); |
| } |
| |
| } // namespace internal |
| } // namespace v8 |
| |
| #endif // V8_UTILS_UTILS_H_ |