node/src/node_internals.h

// 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_NODE_INTERNALS_H_
#define SRC_NODE_INTERNALS_H_

#if defined(NODE_WANT_INTERNALS) && NODE_WANT_INTERNALS

#include "node.h"
#include "util.h"
#include "util-inl.h"
#include "uv.h"
#include "v8.h"
#include "tracing/trace_event.h"

#include <stdint.h>
#include <stdlib.h>

#include <string>

struct sockaddr;

// 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);                               \
    v8::Local<v8::String> constant_value =                                    \
        v8::String::NewFromUtf8(isolate, constant);                           \
    v8::PropertyAttribute constant_attributes =                               \
        static_cast<v8::PropertyAttribute>(v8::ReadOnly | v8::DontDelete);    \
    target->DefineOwnProperty(isolate->GetCurrentContext(),                   \
                              constant_name,                                  \
                              constant_value,                                 \
                              constant_attributes).FromJust();                \
  } while (0)

namespace node {

// Set in node.cc by ParseArgs with the value of --openssl-config.
// Used in node_crypto.cc when initializing OpenSSL.
extern std::string openssl_config;

// Set in node.cc by ParseArgs when --preserve-symlinks is used.
// Used in node_config.cc to set a constant on process.binding('config')
// that is used by lib/module.js
extern bool config_preserve_symlinks;

// Set in node.cc by ParseArgs when --expose-internals or --expose_internals is
// used.
// Used in node_config.cc to set a constant on process.binding('config')
// that is used by lib/internal/bootstrap_node.js
extern bool config_expose_internals;

// Set in node.cc by ParseArgs when --redirect-warnings= is used.
// Used to redirect warning output to a file rather than sending
// it to stderr.
extern std::string config_warning_file;  // NOLINT(runtime/string)

// Set in node.cc by ParseArgs when --pending-deprecation or
// NODE_PENDING_DEPRECATION is used
extern bool config_pending_deprecation;

// Tells whether it is safe to call v8::Isolate::GetCurrent().
extern bool v8_initialized;

// Forward declaration
class Environment;

// 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>
inline v8::Local<TypeName> PersistentToLocal(
    v8::Isolate* isolate,
    const v8::Persistent<TypeName>& persistent);

// Call with valid HandleScope and while inside Context scope.
v8::Local<v8::Value> MakeCallback(Environment* env,
                                   v8::Local<v8::Object> recv,
                                   const char* method,
                                   int argc = 0,
                                   v8::Local<v8::Value>* argv = nullptr);

// Call with valid HandleScope and while inside Context scope.
v8::Local<v8::Value> MakeCallback(Environment* env,
                                   v8::Local<v8::Object> recv,
                                   v8::Local<v8::String> symbol,
                                   int argc = 0,
                                   v8::Local<v8::Value>* argv = nullptr);

// Call with valid HandleScope and while inside Context scope.
v8::Local<v8::Value> MakeCallback(Environment* env,
                                   v8::Local<v8::Value> recv,
                                   v8::Local<v8::Function> callback,
                                   int argc = 0,
                                   v8::Local<v8::Value>* argv = nullptr);

// Convert a struct sockaddr to a { address: '1.2.3.4', port: 1234 } JS object.
// Sets address and port properties on the info object and returns it.
// If |info| is omitted, a new object is returned.
v8::Local<v8::Object> AddressToJS(
    Environment* env,
    const sockaddr* addr,
    v8::Local<v8::Object> info = v8::Local<v8::Object>());

template <typename T, int (*F)(const typename T::HandleType*, sockaddr*, int*)>
void GetSockOrPeerName(const v8::FunctionCallbackInfo<v8::Value>& args) {
  T* const wrap = Unwrap<T>(args.Holder());
  if (wrap == nullptr)
    return args.GetReturnValue().Set(UV_EBADF);
  CHECK(args[0]->IsObject());
  sockaddr_storage storage;
  int addrlen = sizeof(storage);
  sockaddr* const addr = reinterpret_cast<sockaddr*>(&storage);
  const int err = F(&wrap->handle_, addr, &addrlen);
  if (err == 0)
    AddressToJS(wrap->env(), addr, args[0].As<v8::Object>());
  args.GetReturnValue().Set(err);
}

void SignalExit(int signo);
#ifdef __POSIX__
void RegisterSignalHandler(int signal,
                           void (*handler)(int signal),
                           bool reset_handler = false);
#endif

bool SafeGetenv(const char* key, std::string* text);

template <typename T, size_t N>
constexpr size_t arraysize(const T(&)[N]) { return N; }

#ifndef ROUND_UP
# define ROUND_UP(a, b) ((a) % (b) ? ((a) + (b)) - ((a) % (b)) : (a))
#endif

#ifdef __GNUC__
# define MUST_USE_RESULT __attribute__((warn_unused_result))
#else
# define MUST_USE_RESULT
#endif

bool IsExceptionDecorated(Environment* env, v8::Local<v8::Value> er);

enum ErrorHandlingMode { FATAL_ERROR, CONTEXTIFY_ERROR };
void AppendExceptionLine(Environment* env,
                         v8::Local<v8::Value> er,
                         v8::Local<v8::Message> message,
                         enum ErrorHandlingMode mode);

NO_RETURN void FatalError(const char* location, const char* message);

void ProcessEmitWarning(Environment* env, const char* fmt, ...);

void FillStatsArray(double* fields, const uv_stat_t* s);

void SetupProcessObject(Environment* env,
                        int argc,
                        const char* const* argv,
                        int exec_argc,
                        const char* const* exec_argv);

enum Endianness {
  kLittleEndian,  // _Not_ LITTLE_ENDIAN, clashes with endian.h.
  kBigEndian
};

inline enum Endianness GetEndianness() {
  // Constant-folded by the compiler.
  const union {
    uint8_t u8[2];
    uint16_t u16;
  } u = {
    { 1, 0 }
  };
  return u.u16 == 1 ? kLittleEndian : kBigEndian;
}

inline bool IsLittleEndian() {
  return GetEndianness() == kLittleEndian;
}

inline bool IsBigEndian() {
  return GetEndianness() == kBigEndian;
}

class ArrayBufferAllocator : public v8::ArrayBuffer::Allocator {
 public:
  inline uint32_t* zero_fill_field() { return &zero_fill_field_; }

  virtual void* Allocate(size_t size);  // Defined in src/node.cc
  virtual void* AllocateUninitialized(size_t size)
    { return node::UncheckedMalloc(size); }
  virtual void Free(void* data, size_t) { free(data); }

 private:
  uint32_t zero_fill_field_ = 1;  // Boolean but exposed as uint32 to JS land.
};

// Clear any domain and/or uncaughtException handlers to force the error's
// propagation and shutdown the process. Use this to force the process to exit
// by clearing all callbacks that could handle the error.
void ClearFatalExceptionHandlers(Environment* env);

namespace Buffer {
v8::MaybeLocal<v8::Object> Copy(Environment* env, const char* data, size_t len);
v8::MaybeLocal<v8::Object> New(Environment* env, size_t size);
// Takes ownership of |data|.
v8::MaybeLocal<v8::Object> New(Environment* env,
                               char* data,
                               size_t length,
                               void (*callback)(char* data, void* hint),
                               void* hint);
// Takes ownership of |data|.  Must allocate |data| with malloc() or realloc()
// because ArrayBufferAllocator::Free() deallocates it again with free().
// Mixing operator new and free() is undefined behavior so don't do that.
v8::MaybeLocal<v8::Object> New(Environment* env, char* data, size_t length);

// Construct a Buffer from a MaybeStackBuffer (and also its subclasses like
// Utf8Value and TwoByteValue).
// If |buf| is invalidated, an empty MaybeLocal is returned, and nothing is
// changed.
// If |buf| contains actual data, this method takes ownership of |buf|'s
// underlying buffer. However, |buf| itself can be reused even after this call,
// but its capacity, if increased through AllocateSufficientStorage, is not
// guaranteed to stay the same.
template <typename T>
static v8::MaybeLocal<v8::Object> New(Environment* env,
                                      MaybeStackBuffer<T>* buf) {
  v8::MaybeLocal<v8::Object> ret;
  char* src = reinterpret_cast<char*>(buf->out());
  const size_t len_in_bytes = buf->length() * sizeof(buf->out()[0]);

  if (buf->IsAllocated())
    ret = New(env, src, len_in_bytes);
  else if (!buf->IsInvalidated())
    ret = Copy(env, src, len_in_bytes);

  if (ret.IsEmpty())
    return ret;

  if (buf->IsAllocated())
    buf->Release();

  return ret;
}
}  // namespace Buffer

}  // namespace node

#endif  // defined(NODE_WANT_INTERNALS) && NODE_WANT_INTERNALS

#endif  // SRC_NODE_INTERNALS_H_