// Copyright Joyent, Inc. and other Node contributors.

//

// Permission is hereby granted, free of charge, to any person obtaining a

// copy of this software and associated documentation files (the

// "Software"), to deal in the Software without restriction, including

// without limitation the rights to use, copy, modify, merge, publish,

// distribute, sublicense, and/or sell copies of the Software, and to permit

// persons to whom the Software is furnished to do so, subject to the

// following conditions:

//

// The above copyright notice and this permission notice shall be included

// in all copies or substantial portions of the Software.

//

// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS

// OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF

// MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN

// NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM,

// DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR

// OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE

// USE OR OTHER DEALINGS IN THE SOFTWARE.

#ifndef SRC_UTIL_H_

#define SRC_UTIL_H_

#if defined(NODE_WANT_INTERNALS) && NODE_WANT_INTERNALS

#include "v8.h"

#include "node.h"

#include <climits>

#include <cstddef>

#include <cstdio>

#include <cstdlib>

#include <cstring>

#include <array>

#include <limits>

#include <memory>

#include <string>

#include <string_view>

#include <type_traits>

#include <set>

#include <unordered_map>

#include <utility>

#include <vector>

#ifdef __GNUC__

#define MUST_USE_RESULT __attribute__((warn_unused_result))

#else

#define MUST_USE_RESULT

#endif

namespace node {

// Maybe remove kPathSeparator when cpp17 is ready

#ifdef _WIN32

    constexpr char kPathSeparator = '\\';

/* MAX_PATH is in characters, not bytes. Make sure we have enough headroom. */

#define PATH_MAX_BYTES (MAX_PATH * 4)

#else

    constexpr char kPathSeparator = '/';

#define PATH_MAX_BYTES (PATH_MAX)

#endif

// These should be used in our code as opposed to the native

// versions as they abstract out some platform and or

// compiler version specific functionality

// malloc(0) and realloc(ptr, 0) have implementation-defined behavior in

// that the standard allows them to either return a unique pointer or a

// nullptr for zero-sized allocation requests.  Normalize by always using

// a nullptr.

template <typename T>

inline T* UncheckedRealloc(T* pointer, size_t n);

template <typename T>

inline T* UncheckedMalloc(size_t n);

template <typename T>

inline T* UncheckedCalloc(size_t n);

// Same things, but aborts immediately instead of returning nullptr when

// no memory is available.

template <typename T>

inline T* Realloc(T* pointer, size_t n);

template <typename T>

inline T* Malloc(size_t n);

template <typename T>

inline T* Calloc(size_t n);

inline char* Malloc(size_t n);

inline char* Calloc(size_t n);

inline char* UncheckedMalloc(size_t n);

inline char* UncheckedCalloc(size_t n);

template <typename T>

inline T MultiplyWithOverflowCheck(T a, T b);

namespace per_process {

// Tells whether the per-process V8::Initialize() is called and

// if it is safe to call v8::Isolate::TryGetCurrent().

extern bool v8_initialized;

}  // namespace per_process

// Used by the allocation functions when allocation fails.

// Thin wrapper around v8::Isolate::LowMemoryNotification() that checks

// whether V8 is initialized.

void LowMemoryNotification();

// The reason that Assert() takes a struct argument instead of individual

// const char*s is to ease instruction cache pressure in calls from CHECK.

struct AssertionInfo {

  const char* file_line;  // filename:line

  const char* message;

  const char* function;

};

[[noreturn]] void NODE_EXTERN_PRIVATE Assert(const AssertionInfo& info);

[[noreturn]] void NODE_EXTERN_PRIVATE Abort();

void DumpBacktrace(FILE* fp);

// Windows 8+ does not like abort() in Release mode

#ifdef _WIN32

#define ABORT_NO_BACKTRACE() _exit(134)

#else

#define ABORT_NO_BACKTRACE() abort()

#endif

#define ABORT() node::Abort()

#define ERROR_AND_ABORT(expr)                                                 \

  do {                                                                        \

    /* Make sure that this struct does not end up in inline code, but      */ \

    /* rather in a read-only data section when modifying this code.        */ \

    static const node::AssertionInfo args = {                                 \

      __FILE__ ":" STRINGIFY(__LINE__), #expr, PRETTY_FUNCTION_NAME           \

    };                                                                        \

    node::Assert(args);                                                       \

  } while (0)

#ifdef __GNUC__

#define LIKELY(expr) __builtin_expect(!!(expr), 1)

#define UNLIKELY(expr) __builtin_expect(!!(expr), 0)

#define PRETTY_FUNCTION_NAME __PRETTY_FUNCTION__

#else

#define LIKELY(expr) expr

#define UNLIKELY(expr) expr

#define PRETTY_FUNCTION_NAME ""

#endif

#define STRINGIFY_(x) #x

#define STRINGIFY(x) STRINGIFY_(x)

#define CHECK(expr)                                                           \

  do {                                                                        \

    if (UNLIKELY(!(expr))) {                                                  \

      ERROR_AND_ABORT(expr);                                                  \

    }                                                                         \

  } while (0)

#define CHECK_EQ(a, b) CHECK((a) == (b))

#define CHECK_GE(a, b) CHECK((a) >= (b))

#define CHECK_GT(a, b) CHECK((a) > (b))

#define CHECK_LE(a, b) CHECK((a) <= (b))

#define CHECK_LT(a, b) CHECK((a) < (b))

#define CHECK_NE(a, b) CHECK((a) != (b))

#define CHECK_NULL(val) CHECK((val) == nullptr)

#define CHECK_NOT_NULL(val) CHECK((val) != nullptr)

#define CHECK_IMPLIES(a, b) CHECK(!(a) || (b))

#ifdef DEBUG

  #define DCHECK(expr) CHECK(expr)

  #define DCHECK_EQ(a, b) CHECK((a) == (b))

  #define DCHECK_GE(a, b) CHECK((a) >= (b))

  #define DCHECK_GT(a, b) CHECK((a) > (b))

  #define DCHECK_LE(a, b) CHECK((a) <= (b))

  #define DCHECK_LT(a, b) CHECK((a) < (b))

  #define DCHECK_NE(a, b) CHECK((a) != (b))

  #define DCHECK_NULL(val) CHECK((val) == nullptr)

  #define DCHECK_NOT_NULL(val) CHECK((val) != nullptr)

  #define DCHECK_IMPLIES(a, b) CHECK(!(a) || (b))

#else

  #define DCHECK(expr)

  #define DCHECK_EQ(a, b)

  #define DCHECK_GE(a, b)

  #define DCHECK_GT(a, b)

  #define DCHECK_LE(a, b)

  #define DCHECK_LT(a, b)

  #define DCHECK_NE(a, b)

  #define DCHECK_NULL(val)

  #define DCHECK_NOT_NULL(val)

  #define DCHECK_IMPLIES(a, b)

#endif

#define UNREACHABLE(...)                                                      \

  ERROR_AND_ABORT("Unreachable code reached" __VA_OPT__(": ") __VA_ARGS__)

// ECMA262 20.1.2.6 Number.MAX_SAFE_INTEGER (2^53-1)

constexpr int64_t kMaxSafeJsInteger = 9007199254740991;

inline bool IsSafeJsInt(v8::Local<v8::Value> v);

// TAILQ-style intrusive list node.

template <typename T>

class ListNode;

// TAILQ-style intrusive list head.

template <typename T, ListNode<T> (T::*M)>

class ListHead;

template <typename T>

class ListNode {

 public:

  inline ListNode();

  inline ~ListNode();

  inline void Remove();

  inline bool IsEmpty() const;

  ListNode(const ListNode&) = delete;

  ListNode& operator=(const ListNode&) = delete;

 private:

  template <typename U, ListNode<U> (U::*M)> friend class ListHead;

  friend int GenDebugSymbols();

  ListNode* prev_;

  ListNode* next_;

};

template <typename T, ListNode<T> (T::*M)>

class ListHead {

 public:

  class Iterator {

   public:

    inline T* operator*() const;

    inline const Iterator& operator++();

    inline bool operator!=(const Iterator& that) const;

   private:

    friend class ListHead;

    inline explicit Iterator(ListNode<T>* node);

    ListNode<T>* node_;

  };

  inline ~ListHead();

  inline void PushBack(T* element);

  inline void PushFront(T* element);

  inline bool IsEmpty() const;

  inline T* PopFront();

  inline Iterator begin() const;

  inline Iterator end() const;

  ListHead(const ListHead&) = delete;

  ListHead& operator=(const ListHead&) = delete;

 private:

  friend int GenDebugSymbols();

  ListNode<T> head_;

};

// The helper is for doing safe downcasts from base types to derived types.

template <typename Inner, typename Outer>

class ContainerOfHelper {

 public:

  inline ContainerOfHelper(Inner Outer::*field, Inner* pointer);

  template <typename TypeName>

  inline operator TypeName*() const;

 private:

  Outer* const pointer_;

};

// Calculate the address of the outer (i.e. embedding) struct from

// the interior pointer to a data member.

template <typename Inner, typename Outer>

constexpr ContainerOfHelper<Inner, Outer> ContainerOf(Inner Outer::*field,

                                                      Inner* pointer);

// Convenience wrapper around v8::String::NewFromOneByte().

inline v8::Local<v8::String> OneByteString(v8::Isolate* isolate,

                                           const char* data,

                                           int length = -1);

// For the people that compile with -funsigned-char.

inline v8::Local<v8::String> OneByteString(v8::Isolate* isolate,

                                           const signed char* data,

                                           int length = -1);

inline v8::Local<v8::String> OneByteString(v8::Isolate* isolate,

                                           const unsigned char* data,

                                           int length = -1);

// Used to be a macro, hence the uppercase name.

template <int N>

    v8::Isolate* isolate,

    const char(&data)[N]) {

}

template <std::size_t N>

    v8::Isolate* isolate,

    const std::array<char, N>& arr) {

}

// Swaps bytes in place. nbytes is the number of bytes to swap and must be a

// multiple of the word size (checked by function).

inline void SwapBytes16(char* data, size_t nbytes);

inline void SwapBytes32(char* data, size_t nbytes);

inline void SwapBytes64(char* data, size_t nbytes);

// tolower() is locale-sensitive.  Use ToLower() instead.

inline char ToLower(char c);

inline std::string ToLower(const std::string& in);

// toupper() is locale-sensitive.  Use ToUpper() instead.

inline char ToUpper(char c);

inline std::string ToUpper(const std::string& in);

// strcasecmp() is locale-sensitive.  Use StringEqualNoCase() instead.

inline bool StringEqualNoCase(const char* a, const char* b);

// strncasecmp() is locale-sensitive.  Use StringEqualNoCaseN() instead.

inline bool StringEqualNoCaseN(const char* a, const char* b, size_t length);

template <typename T, size_t N>

}

template <typename T, size_t N>

constexpr size_t strsize(const T (&)[N]) {

  return N - 1;

}

// Allocates an array of member type T. For up to kStackStorageSize items,

// the stack is used, otherwise malloc().

template <typename T, size_t kStackStorageSize = 1024>

class MaybeStackBuffer {

 public:

  }

  }

  // operator* for compatibility with `v8::String::(Utf8)Value`

  }

  }

  }

  }

  }

  // Current maximum capacity of the buffer with which SetLength() can be used

  // without first calling AllocateSufficientStorage().

  }

  // Make sure enough space for `storage` entries is available.

  // This method can be called multiple times throughout the lifetime of the

  // buffer, but once this has been called Invalidate() cannot be used.

  // Content of the buffer in the range [0, length()) is preserved.

    }

    // capacity() returns how much memory is actually available.

    // capacity() returns how much memory is actually available.

    // T() is 0 for integer types, nullptr for pointers, etc.

  // Make dereferencing this object return nullptr.

  // This method can be called multiple times throughout the lifetime of the

  // buffer, but once this has been called AllocateSufficientStorage() cannot

  // be used.

  // If the buffer is stored in the heap rather than on the stack.

  }

  // If Invalidate() has been called.

  }

  // Release ownership of the malloc'd buffer.

  // Note: This does not free the buffer.

    // Default to a zero-length, null-terminated buffer.

 private:

  size_t length_;

  // capacity of the malloc'ed buf_

  size_t capacity_;

  T* buf_;

  T buf_st_[kStackStorageSize];

};

// Provides access to an ArrayBufferView's storage, either the original,

// or for small data, a copy of it. This object's lifetime is bound to the

// original ArrayBufferView's lifetime.

template <typename T, size_t kStackStorageSize = 64>

class ArrayBufferViewContents {

 public:

  explicit inline ArrayBufferViewContents(v8::Local<v8::Value> value);

  explicit inline ArrayBufferViewContents(v8::Local<v8::Object> value);

  explicit inline ArrayBufferViewContents(v8::Local<v8::ArrayBufferView> abv);

  inline void Read(v8::Local<v8::ArrayBufferView> abv);

 private:

  T stack_storage_[kStackStorageSize];

  T* data_ = nullptr;

  size_t length_ = 0;

};

class Utf8Value : public MaybeStackBuffer<char> {

 public:

  explicit Utf8Value(v8::Isolate* isolate, v8::Local<v8::Value> value);

  }

};

class TwoByteValue : public MaybeStackBuffer<uint16_t> {

 public:

  explicit TwoByteValue(v8::Isolate* isolate, v8::Local<v8::Value> value);

};

class BufferValue : public MaybeStackBuffer<char> {

 public:

  explicit BufferValue(v8::Isolate* isolate, v8::Local<v8::Value> value);

  inline std::string ToString() const { return std::string(out(), length()); }

};

#define SPREAD_BUFFER_ARG(val, name)                                          \

  CHECK((val)->IsArrayBufferView());                                          \

  v8::Local<v8::ArrayBufferView> name = (val).As<v8::ArrayBufferView>();      \

  std::shared_ptr<v8::BackingStore> name##_bs =                               \

      name->Buffer()->GetBackingStore();                                      \

  const size_t name##_offset = name->ByteOffset();                            \

  const size_t name##_length = name->ByteLength();                            \

  char* const name##_data =                                                   \

      static_cast<char*>(name##_bs->Data()) + name##_offset;                  \

  if (name##_length > 0)                                                      \

    CHECK_NE(name##_data, nullptr);

// Use this when a variable or parameter is unused in order to explicitly

// silence a compiler warning about that.

template <typename Fn>

struct OnScopeLeaveImpl {

  Fn fn_;

  bool active_;

  OnScopeLeaveImpl(const OnScopeLeaveImpl& other) = delete;

  OnScopeLeaveImpl& operator=(const OnScopeLeaveImpl& other) = delete;

  OnScopeLeaveImpl(OnScopeLeaveImpl&& other)

    : fn_(std::move(other.fn_)), active_(other.active_) {

    other.active_ = false;

  }

  OnScopeLeaveImpl& operator=(OnScopeLeaveImpl&& other) {

    if (this == &other) return *this;

    this->~OnScopeLeave();

    new (this)OnScopeLeaveImpl(std::move(other));

    return *this;

  }

};

// Run a function when exiting the current scope. Used like this:

// auto on_scope_leave = OnScopeLeave([&] {

//   // ... run some code ...

// });

template <typename Fn>

}

// Simple RAII wrapper for contiguous data that uses malloc()/free().

template <typename T>

struct MallocedBuffer {

  T* data;

  size_t size;

  T* release() {

    T* ret = data;

    data = nullptr;

    return ret;

  }

  void Truncate(size_t new_size) {

    CHECK(new_size <= size);

    size = new_size;

  }

  void Realloc(size_t new_size) {

    Truncate(new_size);

    data = UncheckedRealloc(data, new_size);

  }

  }

  MallocedBuffer(const MallocedBuffer&) = delete;

  MallocedBuffer& operator=(const MallocedBuffer&) = delete;

};

template <typename T>

class NonCopyableMaybe {

 public:

      : empty_(false),

  }

  }

  }

  }

 private:

  bool empty_;

  T value_;

};

// Test whether some value can be called with ().

template <typename T, typename = void>

struct is_callable : std::is_function<T> { };

template <typename T>

struct is_callable<T, typename std::enable_if<

    std::is_same<decltype(void(&T::operator())), void>::value

    >::type> : std::true_type { };

template <typename T, void (*function)(T*)>

struct FunctionDeleter {

  typedef std::unique_ptr<T, FunctionDeleter> Pointer;

};

template <typename T, void (*function)(T*)>

using DeleteFnPtr = typename FunctionDeleter<T, function>::Pointer;

std::vector<std::string> SplitString(const std::string& in, char delim);

inline v8::MaybeLocal<v8::Value> ToV8Value(v8::Local<v8::Context> context,

                                           std::string_view str,

                                           v8::Isolate* isolate = nullptr);

template <typename T, typename test_for_number =

    typename std::enable_if<std::numeric_limits<T>::is_specialized, bool>::type>

inline v8::MaybeLocal<v8::Value> ToV8Value(v8::Local<v8::Context> context,

                                           const T& number,

                                           v8::Isolate* isolate = nullptr);

template <typename T>

inline v8::MaybeLocal<v8::Value> ToV8Value(v8::Local<v8::Context> context,

                                           const std::vector<T>& vec,

                                           v8::Isolate* isolate = nullptr);

template <typename T>

inline v8::MaybeLocal<v8::Value> ToV8Value(v8::Local<v8::Context> context,

                                           const std::set<T>& set,

                                           v8::Isolate* isolate = nullptr);

template <typename T, typename U>

inline v8::MaybeLocal<v8::Value> ToV8Value(v8::Local<v8::Context> context,

                                           const std::unordered_map<T, U>& map,

                                           v8::Isolate* isolate = nullptr);

// These macros expects a `Isolate* isolate` and a `Local<Context> context`

// to be in the scope.

#define READONLY_PROPERTY(obj, name, value)                                    \

  do {                                                                         \

    obj->DefineOwnProperty(                                                    \

           context, FIXED_ONE_BYTE_STRING(isolate, name), value, v8::ReadOnly) \

        .Check();                                                              \

  } while (0)

#define READONLY_DONT_ENUM_PROPERTY(obj, name, var)                            \

  do {                                                                         \

    obj->DefineOwnProperty(                                                    \

           context,                                                            \

           OneByteString(isolate, name),                                       \

           var,                                                                \

           static_cast<v8::PropertyAttribute>(v8::ReadOnly | v8::DontEnum))    \

        .Check();                                                              \

  } while (0)

#define READONLY_FALSE_PROPERTY(obj, name)                                     \

  READONLY_PROPERTY(obj, name, v8::False(isolate))

#define READONLY_TRUE_PROPERTY(obj, name)                                      \

  READONLY_PROPERTY(obj, name, v8::True(isolate))

#define READONLY_STRING_PROPERTY(obj, name, str)                               \

  READONLY_PROPERTY(obj, name, ToV8Value(context, str).ToLocalChecked())

// Variation on NODE_DEFINE_CONSTANT that sets a String value.

#define NODE_DEFINE_STRING_CONSTANT(target, name, constant)                    \

  do {                                                                         \

    v8::Isolate* isolate = target->GetIsolate();                               \

    v8::Local<v8::String> constant_name =                                      \

        v8::String::NewFromUtf8(isolate, name).ToLocalChecked();               \

    v8::Local<v8::String> constant_value =                                     \

        v8::String::NewFromUtf8(isolate, constant).ToLocalChecked();           \

    v8::PropertyAttribute constant_attributes =                                \

        static_cast<v8::PropertyAttribute>(v8::ReadOnly | v8::DontDelete);     \

    target                                                                     \

        ->DefineOwnProperty(isolate->GetCurrentContext(),                      \

                            constant_name,                                     \

                            constant_value,                                    \

                            constant_attributes)                               \

        .Check();                                                              \

  } while (0)

enum Endianness {

  kLittleEndian,  // _Not_ LITTLE_ENDIAN, clashes with endian.h.

  kBigEndian

};

  // Constant-folded by the compiler.

  const union {

    uint8_t u8[2];

    uint16_t u16;

}

}

}

// Round up a to the next highest multiple of b.

template <typename T>

}

// Align ptr to an `alignment`-bytes boundary.

template <typename T, typename U>

  return reinterpret_cast<T*>(

}

class SlicedArguments : public MaybeStackBuffer<v8::Local<v8::Value>> {

 public:

  inline explicit SlicedArguments(

      const v8::FunctionCallbackInfo<v8::Value>& args, size_t start = 0);

};

// Convert a v8::PersistentBase, e.g. v8::Global, to a Local, with an extra

// optimization for strong persistent handles.

class PersistentToLocal {

 public:

  // If persistent.IsWeak() == false, then do not call persistent.Reset()

  // while the returned Local<T> is still in scope, it will destroy the

  // reference to the object.

  template <class TypeName>

      v8::Isolate* isolate,

      const v8::PersistentBase<TypeName>& persistent) {

    } else {

    }

  }

  // Unchecked conversion from a non-weak Persistent<T> to Local<T>,

  // use with care!

  //

  // Do not call persistent.Reset() while the returned Local<T> is still in

  // scope, it will destroy the reference to the object.

  template <class TypeName>

      const v8::PersistentBase<TypeName>& persistent) {

    DCHECK(!persistent.IsWeak());

    return *reinterpret_cast<v8::Local<TypeName>*>(

  }

  template <class TypeName>

      v8::Isolate* isolate,

      const v8::PersistentBase<TypeName>& persistent) {

  }

};

// Can be used as a key for std::unordered_map when lookup performance is more

// important than size and the keys are statically used to avoid redundant hash

// computations.

class FastStringKey {

 public:

  constexpr explicit FastStringKey(const char* name);

  struct Hash {

    constexpr size_t operator()(const FastStringKey& key) const;

  };

  constexpr bool operator==(const FastStringKey& other) const;

  constexpr const char* c_str() const;

 private:

  static constexpr size_t HashImpl(const char* str);

  const char* name_;

  size_t cached_hash_;

};

// Like std::static_pointer_cast but for unique_ptr with the default deleter.

template <typename T, typename U>

}

#define MAYBE_FIELD_PTR(ptr, field) ptr == nullptr ? nullptr : &(ptr->field)

// Returns a non-zero code if it fails to open or read the file,

// aborts if it fails to close the file.

int ReadFileSync(std::string* result, const char* path);

}  // namespace node

#endif  // defined(NODE_WANT_INTERNALS) && NODE_WANT_INTERNALS

#endif  // SRC_UTIL_H_