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Diffstat (limited to 'chromium/v8/include/v8-primitive.h')
| -rw-r--r-- | chromium/v8/include/v8-primitive.h | 858 |
1 files changed, 858 insertions, 0 deletions
diff --git a/chromium/v8/include/v8-primitive.h b/chromium/v8/include/v8-primitive.h new file mode 100644 index 00000000000..59d959da057 --- /dev/null +++ b/chromium/v8/include/v8-primitive.h @@ -0,0 +1,858 @@ +// Copyright 2021 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 INCLUDE_V8_PRIMITIVE_H_ +#define INCLUDE_V8_PRIMITIVE_H_ + +#include "v8-data.h" // NOLINT(build/include_directory) +#include "v8-internal.h" // NOLINT(build/include_directory) +#include "v8-local-handle.h" // NOLINT(build/include_directory) +#include "v8-value.h" // NOLINT(build/include_directory) +#include "v8config.h" // NOLINT(build/include_directory) + +namespace v8 { + +class Context; +class Isolate; +class String; + +namespace internal { +class ExternalString; +class ScopedExternalStringLock; +} // namespace internal + +/** + * The superclass of primitive values. See ECMA-262 4.3.2. + */ +class V8_EXPORT Primitive : public Value {}; + +/** + * A primitive boolean value (ECMA-262, 4.3.14). Either the true + * or false value. + */ +class V8_EXPORT Boolean : public Primitive { + public: + bool Value() const; + V8_INLINE static Boolean* Cast(v8::Data* data) { +#ifdef V8_ENABLE_CHECKS + CheckCast(data); +#endif + return static_cast<Boolean*>(data); + } + + V8_INLINE static Local<Boolean> New(Isolate* isolate, bool value); + + private: + static void CheckCast(v8::Data* that); +}; + +/** + * An array to hold Primitive values. This is used by the embedder to + * pass host defined options to the ScriptOptions during compilation. + * + * This is passed back to the embedder as part of + * HostImportModuleDynamicallyCallback for module loading. + */ +class V8_EXPORT PrimitiveArray { + public: + static Local<PrimitiveArray> New(Isolate* isolate, int length); + int Length() const; + void Set(Isolate* isolate, int index, Local<Primitive> item); + Local<Primitive> Get(Isolate* isolate, int index); +}; + +/** + * A superclass for symbols and strings. + */ +class V8_EXPORT Name : public Primitive { + public: + /** + * Returns the identity hash for this object. The current implementation + * uses an inline property on the object to store the identity hash. + * + * The return value will never be 0. Also, it is not guaranteed to be + * unique. + */ + int GetIdentityHash(); + + V8_INLINE static Name* Cast(Data* data) { +#ifdef V8_ENABLE_CHECKS + CheckCast(data); +#endif + return static_cast<Name*>(data); + } + + private: + static void CheckCast(Data* that); +}; + +/** + * A flag describing different modes of string creation. + * + * Aside from performance implications there are no differences between the two + * creation modes. + */ +enum class NewStringType { + /** + * Create a new string, always allocating new storage memory. + */ + kNormal, + + /** + * Acts as a hint that the string should be created in the + * old generation heap space and be deduplicated if an identical string + * already exists. + */ + kInternalized +}; + +/** + * A JavaScript string value (ECMA-262, 4.3.17). + */ +class V8_EXPORT String : public Name { + public: + static constexpr int kMaxLength = + internal::kApiSystemPointerSize == 4 ? (1 << 28) - 16 : (1 << 29) - 24; + + enum Encoding { + UNKNOWN_ENCODING = 0x1, + TWO_BYTE_ENCODING = 0x0, + ONE_BYTE_ENCODING = 0x8 + }; + /** + * Returns the number of characters (UTF-16 code units) in this string. + */ + int Length() const; + + /** + * Returns the number of bytes in the UTF-8 encoded + * representation of this string. + */ + int Utf8Length(Isolate* isolate) const; + + /** + * Returns whether this string is known to contain only one byte data, + * i.e. ISO-8859-1 code points. + * Does not read the string. + * False negatives are possible. + */ + bool IsOneByte() const; + + /** + * Returns whether this string contain only one byte data, + * i.e. ISO-8859-1 code points. + * Will read the entire string in some cases. + */ + bool ContainsOnlyOneByte() const; + + /** + * Write the contents of the string to an external buffer. + * If no arguments are given, expects the buffer to be large + * enough to hold the entire string and NULL terminator. Copies + * the contents of the string and the NULL terminator into the + * buffer. + * + * WriteUtf8 will not write partial UTF-8 sequences, preferring to stop + * before the end of the buffer. + * + * Copies up to length characters into the output buffer. + * Only null-terminates if there is enough space in the buffer. + * + * \param buffer The buffer into which the string will be copied. + * \param start The starting position within the string at which + * copying begins. + * \param length The number of characters to copy from the string. For + * WriteUtf8 the number of bytes in the buffer. + * \param nchars_ref The number of characters written, can be NULL. + * \param options Various options that might affect performance of this or + * subsequent operations. + * \return The number of characters copied to the buffer excluding the null + * terminator. For WriteUtf8: The number of bytes copied to the buffer + * including the null terminator (if written). + */ + enum WriteOptions { + NO_OPTIONS = 0, + HINT_MANY_WRITES_EXPECTED = 1, + NO_NULL_TERMINATION = 2, + PRESERVE_ONE_BYTE_NULL = 4, + // Used by WriteUtf8 to replace orphan surrogate code units with the + // unicode replacement character. Needs to be set to guarantee valid UTF-8 + // output. + REPLACE_INVALID_UTF8 = 8 + }; + + // 16-bit character codes. + int Write(Isolate* isolate, uint16_t* buffer, int start = 0, int length = -1, + int options = NO_OPTIONS) const; + // One byte characters. + int WriteOneByte(Isolate* isolate, uint8_t* buffer, int start = 0, + int length = -1, int options = NO_OPTIONS) const; + // UTF-8 encoded characters. + int WriteUtf8(Isolate* isolate, char* buffer, int length = -1, + int* nchars_ref = nullptr, int options = NO_OPTIONS) const; + + /** + * A zero length string. + */ + V8_INLINE static Local<String> Empty(Isolate* isolate); + + /** + * Returns true if the string is external. + */ + bool IsExternal() const; + + /** + * Returns true if the string is both external and two-byte. + */ + bool IsExternalTwoByte() const; + + /** + * Returns true if the string is both external and one-byte. + */ + bool IsExternalOneByte() const; + + class V8_EXPORT ExternalStringResourceBase { + public: + virtual ~ExternalStringResourceBase() = default; + + /** + * If a string is cacheable, the value returned by + * ExternalStringResource::data() may be cached, otherwise it is not + * expected to be stable beyond the current top-level task. + */ + virtual bool IsCacheable() const { return true; } + + // Disallow copying and assigning. + ExternalStringResourceBase(const ExternalStringResourceBase&) = delete; + void operator=(const ExternalStringResourceBase&) = delete; + + protected: + ExternalStringResourceBase() = default; + + /** + * Internally V8 will call this Dispose method when the external string + * resource is no longer needed. The default implementation will use the + * delete operator. This method can be overridden in subclasses to + * control how allocated external string resources are disposed. + */ + virtual void Dispose() { delete this; } + + /** + * For a non-cacheable string, the value returned by + * |ExternalStringResource::data()| has to be stable between |Lock()| and + * |Unlock()|, that is the string must behave as is |IsCacheable()| returned + * true. + * + * These two functions must be thread-safe, and can be called from anywhere. + * They also must handle lock depth, in the sense that each can be called + * several times, from different threads, and unlocking should only happen + * when the balance of Lock() and Unlock() calls is 0. + */ + virtual void Lock() const {} + + /** + * Unlocks the string. + */ + virtual void Unlock() const {} + + private: + friend class internal::ExternalString; + friend class v8::String; + friend class internal::ScopedExternalStringLock; + }; + + /** + * An ExternalStringResource is a wrapper around a two-byte string + * buffer that resides outside V8's heap. Implement an + * ExternalStringResource to manage the life cycle of the underlying + * buffer. Note that the string data must be immutable. + */ + class V8_EXPORT ExternalStringResource : public ExternalStringResourceBase { + public: + /** + * Override the destructor to manage the life cycle of the underlying + * buffer. + */ + ~ExternalStringResource() override = default; + + /** + * The string data from the underlying buffer. If the resource is cacheable + * then data() must return the same value for all invocations. + */ + virtual const uint16_t* data() const = 0; + + /** + * The length of the string. That is, the number of two-byte characters. + */ + virtual size_t length() const = 0; + + /** + * Returns the cached data from the underlying buffer. This method can be + * called only for cacheable resources (i.e. IsCacheable() == true) and only + * after UpdateDataCache() was called. + */ + const uint16_t* cached_data() const { + CheckCachedDataInvariants(); + return cached_data_; + } + + /** + * Update {cached_data_} with the data from the underlying buffer. This can + * be called only for cacheable resources. + */ + void UpdateDataCache(); + + protected: + ExternalStringResource() = default; + + private: + void CheckCachedDataInvariants() const; + + const uint16_t* cached_data_ = nullptr; + }; + + /** + * An ExternalOneByteStringResource is a wrapper around an one-byte + * string buffer that resides outside V8's heap. Implement an + * ExternalOneByteStringResource to manage the life cycle of the + * underlying buffer. Note that the string data must be immutable + * and that the data must be Latin-1 and not UTF-8, which would require + * special treatment internally in the engine and do not allow efficient + * indexing. Use String::New or convert to 16 bit data for non-Latin1. + */ + + class V8_EXPORT ExternalOneByteStringResource + : public ExternalStringResourceBase { + public: + /** + * Override the destructor to manage the life cycle of the underlying + * buffer. + */ + ~ExternalOneByteStringResource() override = default; + + /** + * The string data from the underlying buffer. If the resource is cacheable + * then data() must return the same value for all invocations. + */ + virtual const char* data() const = 0; + + /** The number of Latin-1 characters in the string.*/ + virtual size_t length() const = 0; + + /** + * Returns the cached data from the underlying buffer. If the resource is + * uncacheable or if UpdateDataCache() was not called before, it has + * undefined behaviour. + */ + const char* cached_data() const { + CheckCachedDataInvariants(); + return cached_data_; + } + + /** + * Update {cached_data_} with the data from the underlying buffer. This can + * be called only for cacheable resources. + */ + void UpdateDataCache(); + + protected: + ExternalOneByteStringResource() = default; + + private: + void CheckCachedDataInvariants() const; + + const char* cached_data_ = nullptr; + }; + + /** + * If the string is an external string, return the ExternalStringResourceBase + * regardless of the encoding, otherwise return NULL. The encoding of the + * string is returned in encoding_out. + */ + V8_INLINE ExternalStringResourceBase* GetExternalStringResourceBase( + Encoding* encoding_out) const; + + /** + * Get the ExternalStringResource for an external string. Returns + * NULL if IsExternal() doesn't return true. + */ + V8_INLINE ExternalStringResource* GetExternalStringResource() const; + + /** + * Get the ExternalOneByteStringResource for an external one-byte string. + * Returns NULL if IsExternalOneByte() doesn't return true. + */ + const ExternalOneByteStringResource* GetExternalOneByteStringResource() const; + + V8_INLINE static String* Cast(v8::Data* data) { +#ifdef V8_ENABLE_CHECKS + CheckCast(data); +#endif + return static_cast<String*>(data); + } + + /** + * Allocates a new string from a UTF-8 literal. This is equivalent to calling + * String::NewFromUtf(isolate, "...").ToLocalChecked(), but without the check + * overhead. + * + * When called on a string literal containing '\0', the inferred length is the + * length of the input array minus 1 (for the final '\0') and not the value + * returned by strlen. + **/ + template <int N> + static V8_WARN_UNUSED_RESULT Local<String> NewFromUtf8Literal( + Isolate* isolate, const char (&literal)[N], + NewStringType type = NewStringType::kNormal) { + static_assert(N <= kMaxLength, "String is too long"); + return NewFromUtf8Literal(isolate, literal, type, N - 1); + } + + /** Allocates a new string from UTF-8 data. Only returns an empty value when + * length > kMaxLength. **/ + static V8_WARN_UNUSED_RESULT MaybeLocal<String> NewFromUtf8( + Isolate* isolate, const char* data, + NewStringType type = NewStringType::kNormal, int length = -1); + + /** Allocates a new string from Latin-1 data. Only returns an empty value + * when length > kMaxLength. **/ + static V8_WARN_UNUSED_RESULT MaybeLocal<String> NewFromOneByte( + Isolate* isolate, const uint8_t* data, + NewStringType type = NewStringType::kNormal, int length = -1); + + /** Allocates a new string from UTF-16 data. Only returns an empty value when + * length > kMaxLength. **/ + static V8_WARN_UNUSED_RESULT MaybeLocal<String> NewFromTwoByte( + Isolate* isolate, const uint16_t* data, + NewStringType type = NewStringType::kNormal, int length = -1); + + /** + * Creates a new string by concatenating the left and the right strings + * passed in as parameters. + */ + static Local<String> Concat(Isolate* isolate, Local<String> left, + Local<String> right); + + /** + * Creates a new external string using the data defined in the given + * resource. When the external string is no longer live on V8's heap the + * resource will be disposed by calling its Dispose method. The caller of + * this function should not otherwise delete or modify the resource. Neither + * should the underlying buffer be deallocated or modified except through the + * destructor of the external string resource. + */ + static V8_WARN_UNUSED_RESULT MaybeLocal<String> NewExternalTwoByte( + Isolate* isolate, ExternalStringResource* resource); + + /** + * Associate an external string resource with this string by transforming it + * in place so that existing references to this string in the JavaScript heap + * will use the external string resource. The external string resource's + * character contents need to be equivalent to this string. + * Returns true if the string has been changed to be an external string. + * The string is not modified if the operation fails. See NewExternal for + * information on the lifetime of the resource. + */ + bool MakeExternal(ExternalStringResource* resource); + + /** + * Creates a new external string using the one-byte data defined in the given + * resource. When the external string is no longer live on V8's heap the + * resource will be disposed by calling its Dispose method. The caller of + * this function should not otherwise delete or modify the resource. Neither + * should the underlying buffer be deallocated or modified except through the + * destructor of the external string resource. + */ + static V8_WARN_UNUSED_RESULT MaybeLocal<String> NewExternalOneByte( + Isolate* isolate, ExternalOneByteStringResource* resource); + + /** + * Associate an external string resource with this string by transforming it + * in place so that existing references to this string in the JavaScript heap + * will use the external string resource. The external string resource's + * character contents need to be equivalent to this string. + * Returns true if the string has been changed to be an external string. + * The string is not modified if the operation fails. See NewExternal for + * information on the lifetime of the resource. + */ + bool MakeExternal(ExternalOneByteStringResource* resource); + + /** + * Returns true if this string can be made external. + */ + bool CanMakeExternal() const; + + /** + * Returns true if the strings values are equal. Same as JS ==/===. + */ + bool StringEquals(Local<String> str) const; + + /** + * Converts an object to a UTF-8-encoded character array. Useful if + * you want to print the object. If conversion to a string fails + * (e.g. due to an exception in the toString() method of the object) + * then the length() method returns 0 and the * operator returns + * NULL. + */ + class V8_EXPORT Utf8Value { + public: + Utf8Value(Isolate* isolate, Local<v8::Value> obj); + ~Utf8Value(); + char* operator*() { return str_; } + const char* operator*() const { return str_; } + int length() const { return length_; } + + // Disallow copying and assigning. + Utf8Value(const Utf8Value&) = delete; + void operator=(const Utf8Value&) = delete; + + private: + char* str_; + int length_; + }; + + /** + * Converts an object to a two-byte (UTF-16-encoded) string. + * If conversion to a string fails (eg. due to an exception in the toString() + * method of the object) then the length() method returns 0 and the * operator + * returns NULL. + */ + class V8_EXPORT Value { + public: + Value(Isolate* isolate, Local<v8::Value> obj); + ~Value(); + uint16_t* operator*() { return str_; } + const uint16_t* operator*() const { return str_; } + int length() const { return length_; } + + // Disallow copying and assigning. + Value(const Value&) = delete; + void operator=(const Value&) = delete; + + private: + uint16_t* str_; + int length_; + }; + + private: + void VerifyExternalStringResourceBase(ExternalStringResourceBase* v, + Encoding encoding) const; + void VerifyExternalStringResource(ExternalStringResource* val) const; + ExternalStringResource* GetExternalStringResourceSlow() const; + ExternalStringResourceBase* GetExternalStringResourceBaseSlow( + String::Encoding* encoding_out) const; + + static Local<v8::String> NewFromUtf8Literal(Isolate* isolate, + const char* literal, + NewStringType type, int length); + + static void CheckCast(v8::Data* that); +}; + +// Zero-length string specialization (templated string size includes +// terminator). +template <> +inline V8_WARN_UNUSED_RESULT Local<String> String::NewFromUtf8Literal( + Isolate* isolate, const char (&literal)[1], NewStringType type) { + return String::Empty(isolate); +} + +/** + * Interface for iterating through all external resources in the heap. + */ +class V8_EXPORT ExternalResourceVisitor { + public: + virtual ~ExternalResourceVisitor() = default; + virtual void VisitExternalString(Local<String> string) {} +}; + +/** + * A JavaScript symbol (ECMA-262 edition 6) + */ +class V8_EXPORT Symbol : public Name { + public: + /** + * Returns the description string of the symbol, or undefined if none. + */ + V8_DEPRECATE_SOON("Use Symbol::Description(isolate)") + Local<Value> Description() const; + Local<Value> Description(Isolate* isolate) const; + + /** + * Create a symbol. If description is not empty, it will be used as the + * description. + */ + static Local<Symbol> New(Isolate* isolate, + Local<String> description = Local<String>()); + + /** + * Access global symbol registry. + * Note that symbols created this way are never collected, so + * they should only be used for statically fixed properties. + * Also, there is only one global name space for the descriptions used as + * keys. + * To minimize the potential for clashes, use qualified names as keys. + */ + static Local<Symbol> For(Isolate* isolate, Local<String> description); + + /** + * Retrieve a global symbol. Similar to |For|, but using a separate + * registry that is not accessible by (and cannot clash with) JavaScript code. + */ + static Local<Symbol> ForApi(Isolate* isolate, Local<String> description); + + // Well-known symbols + static Local<Symbol> GetAsyncIterator(Isolate* isolate); + static Local<Symbol> GetHasInstance(Isolate* isolate); + static Local<Symbol> GetIsConcatSpreadable(Isolate* isolate); + static Local<Symbol> GetIterator(Isolate* isolate); + static Local<Symbol> GetMatch(Isolate* isolate); + static Local<Symbol> GetReplace(Isolate* isolate); + static Local<Symbol> GetSearch(Isolate* isolate); + static Local<Symbol> GetSplit(Isolate* isolate); + static Local<Symbol> GetToPrimitive(Isolate* isolate); + static Local<Symbol> GetToStringTag(Isolate* isolate); + static Local<Symbol> GetUnscopables(Isolate* isolate); + + V8_INLINE static Symbol* Cast(Data* data) { +#ifdef V8_ENABLE_CHECKS + CheckCast(data); +#endif + return static_cast<Symbol*>(data); + } + + private: + Symbol(); + static void CheckCast(Data* that); +}; + +/** + * A JavaScript number value (ECMA-262, 4.3.20) + */ +class V8_EXPORT Number : public Primitive { + public: + double Value() const; + static Local<Number> New(Isolate* isolate, double value); + V8_INLINE static Number* Cast(v8::Data* data) { +#ifdef V8_ENABLE_CHECKS + CheckCast(data); +#endif + return static_cast<Number*>(data); + } + + private: + Number(); + static void CheckCast(v8::Data* that); +}; + +/** + * A JavaScript value representing a signed integer. + */ +class V8_EXPORT Integer : public Number { + public: + static Local<Integer> New(Isolate* isolate, int32_t value); + static Local<Integer> NewFromUnsigned(Isolate* isolate, uint32_t value); + int64_t Value() const; + V8_INLINE static Integer* Cast(v8::Data* data) { +#ifdef V8_ENABLE_CHECKS + CheckCast(data); +#endif + return static_cast<Integer*>(data); + } + + private: + Integer(); + static void CheckCast(v8::Data* that); +}; + +/** + * A JavaScript value representing a 32-bit signed integer. + */ +class V8_EXPORT Int32 : public Integer { + public: + int32_t Value() const; + V8_INLINE static Int32* Cast(v8::Data* data) { +#ifdef V8_ENABLE_CHECKS + CheckCast(data); +#endif + return static_cast<Int32*>(data); + } + + private: + Int32(); + static void CheckCast(v8::Data* that); +}; + +/** + * A JavaScript value representing a 32-bit unsigned integer. + */ +class V8_EXPORT Uint32 : public Integer { + public: + uint32_t Value() const; + V8_INLINE static Uint32* Cast(v8::Data* data) { +#ifdef V8_ENABLE_CHECKS + CheckCast(data); +#endif + return static_cast<Uint32*>(data); + } + + private: + Uint32(); + static void CheckCast(v8::Data* that); +}; + +/** + * A JavaScript BigInt value (https://tc39.github.io/proposal-bigint) + */ +class V8_EXPORT BigInt : public Primitive { + public: + static Local<BigInt> New(Isolate* isolate, int64_t value); + static Local<BigInt> NewFromUnsigned(Isolate* isolate, uint64_t value); + /** + * Creates a new BigInt object using a specified sign bit and a + * specified list of digits/words. + * The resulting number is calculated as: + * + * (-1)^sign_bit * (words[0] * (2^64)^0 + words[1] * (2^64)^1 + ...) + */ + static MaybeLocal<BigInt> NewFromWords(Local<Context> context, int sign_bit, + int word_count, const uint64_t* words); + + /** + * Returns the value of this BigInt as an unsigned 64-bit integer. + * If `lossless` is provided, it will reflect whether the return value was + * truncated or wrapped around. In particular, it is set to `false` if this + * BigInt is negative. + */ + uint64_t Uint64Value(bool* lossless = nullptr) const; + + /** + * Returns the value of this BigInt as a signed 64-bit integer. + * If `lossless` is provided, it will reflect whether this BigInt was + * truncated or not. + */ + int64_t Int64Value(bool* lossless = nullptr) const; + + /** + * Returns the number of 64-bit words needed to store the result of + * ToWordsArray(). + */ + int WordCount() const; + + /** + * Writes the contents of this BigInt to a specified memory location. + * `sign_bit` must be provided and will be set to 1 if this BigInt is + * negative. + * `*word_count` has to be initialized to the length of the `words` array. + * Upon return, it will be set to the actual number of words that would + * be needed to store this BigInt (i.e. the return value of `WordCount()`). + */ + void ToWordsArray(int* sign_bit, int* word_count, uint64_t* words) const; + + V8_INLINE static BigInt* Cast(v8::Data* data) { +#ifdef V8_ENABLE_CHECKS + CheckCast(data); +#endif + return static_cast<BigInt*>(data); + } + + private: + BigInt(); + static void CheckCast(v8::Data* that); +}; + +Local<String> String::Empty(Isolate* isolate) { + using S = internal::Address; + using I = internal::Internals; + I::CheckInitialized(isolate); + S* slot = I::GetRoot(isolate, I::kEmptyStringRootIndex); + return Local<String>(reinterpret_cast<String*>(slot)); +} + +String::ExternalStringResource* String::GetExternalStringResource() const { + using A = internal::Address; + using I = internal::Internals; + A obj = *reinterpret_cast<const A*>(this); + + ExternalStringResource* result; + if (I::IsExternalTwoByteString(I::GetInstanceType(obj))) { + internal::Isolate* isolate = I::GetIsolateForHeapSandbox(obj); + A value = + I::ReadExternalPointerField(isolate, obj, I::kStringResourceOffset, + internal::kExternalStringResourceTag); + result = reinterpret_cast<String::ExternalStringResource*>(value); + } else { + result = GetExternalStringResourceSlow(); + } +#ifdef V8_ENABLE_CHECKS + VerifyExternalStringResource(result); +#endif + return result; +} + +String::ExternalStringResourceBase* String::GetExternalStringResourceBase( + String::Encoding* encoding_out) const { + using A = internal::Address; + using I = internal::Internals; + A obj = *reinterpret_cast<const A*>(this); + int type = I::GetInstanceType(obj) & I::kFullStringRepresentationMask; + *encoding_out = static_cast<Encoding>(type & I::kStringEncodingMask); + ExternalStringResourceBase* resource; + if (type == I::kExternalOneByteRepresentationTag || + type == I::kExternalTwoByteRepresentationTag) { + internal::Isolate* isolate = I::GetIsolateForHeapSandbox(obj); + A value = + I::ReadExternalPointerField(isolate, obj, I::kStringResourceOffset, + internal::kExternalStringResourceTag); + resource = reinterpret_cast<ExternalStringResourceBase*>(value); + } else { + resource = GetExternalStringResourceBaseSlow(encoding_out); + } +#ifdef V8_ENABLE_CHECKS + VerifyExternalStringResourceBase(resource, *encoding_out); +#endif + return resource; +} + +// --- Statics --- + +V8_INLINE Local<Primitive> Undefined(Isolate* isolate) { + using S = internal::Address; + using I = internal::Internals; + I::CheckInitialized(isolate); + S* slot = I::GetRoot(isolate, I::kUndefinedValueRootIndex); + return Local<Primitive>(reinterpret_cast<Primitive*>(slot)); +} + +V8_INLINE Local<Primitive> Null(Isolate* isolate) { + using S = internal::Address; + using I = internal::Internals; + I::CheckInitialized(isolate); + S* slot = I::GetRoot(isolate, I::kNullValueRootIndex); + return Local<Primitive>(reinterpret_cast<Primitive*>(slot)); +} + +V8_INLINE Local<Boolean> True(Isolate* isolate) { + using S = internal::Address; + using I = internal::Internals; + I::CheckInitialized(isolate); + S* slot = I::GetRoot(isolate, I::kTrueValueRootIndex); + return Local<Boolean>(reinterpret_cast<Boolean*>(slot)); +} + +V8_INLINE Local<Boolean> False(Isolate* isolate) { + using S = internal::Address; + using I = internal::Internals; + I::CheckInitialized(isolate); + S* slot = I::GetRoot(isolate, I::kFalseValueRootIndex); + return Local<Boolean>(reinterpret_cast<Boolean*>(slot)); +} + +Local<Boolean> Boolean::New(Isolate* isolate, bool value) { + return value ? True(isolate) : False(isolate); +} + +} // namespace v8 + +#endif // INCLUDE_V8_PRIMITIVE_H_ |