node.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_H_
#define SRC_NODE_H_

#ifdef _WIN32
# ifndef BUILDING_NODE_EXTENSION
#  define NODE_EXTERN __declspec(dllexport)
# else
#  define NODE_EXTERN __declspec(dllimport)
# endif
#else
# define NODE_EXTERN __attribute__((visibility("default")))
#endif

// Declarations annotated with NODE_EXTERN_PRIVATE do not form part of
// the public API. They are implementation details that can and will
// change between releases, even in semver patch releases. Do not use
// any such symbol in external code.
#ifdef NODE_SHARED_MODE
#define NODE_EXTERN_PRIVATE NODE_EXTERN
#else
#define NODE_EXTERN_PRIVATE
#endif

#ifdef BUILDING_NODE_EXTENSION
# undef BUILDING_V8_SHARED
# undef BUILDING_UV_SHARED
# define USING_V8_SHARED 1
# define USING_UV_SHARED 1
#endif

// This should be defined in make system.
// See issue https://github.com/nodejs/node-v0.x-archive/issues/1236
#if defined(__MINGW32__) || defined(_MSC_VER)
#ifndef _WIN32_WINNT
# define _WIN32_WINNT 0x0600  // Windows Server 2008
#endif

#ifndef NOMINMAX
# define NOMINMAX
#endif

#endif

#if defined(_MSC_VER)
#define PATH_MAX MAX_PATH
#endif

#ifdef _WIN32
#define SIGQUIT 3
#define SIGKILL 9
#endif

#include "v8.h"  // NOLINT(build/include_order)

#include "v8-platform.h"  // NOLINT(build/include_order)
#include "node_version.h"  // NODE_MODULE_VERSION

#include "node_api_types.h"  //  napi_addon_register_func

#include <functional>
#include <memory>
#include <optional>
#include <ostream>

// We cannot use __POSIX__ in this header because that's only defined when
// building Node.js.
#ifndef _WIN32
#include <signal.h>
#endif  // _WIN32

#define NODE_MAKE_VERSION(major, minor, patch)                                \
  ((major) * 0x1000 + (minor) * 0x100 + (patch))

#ifdef __clang__
# define NODE_CLANG_AT_LEAST(major, minor, patch)                             \
  (NODE_MAKE_VERSION(major, minor, patch) <=                                  \
      NODE_MAKE_VERSION(__clang_major__, __clang_minor__, __clang_patchlevel__))
#else
# define NODE_CLANG_AT_LEAST(major, minor, patch) (0)
#endif

#ifdef __GNUC__
# define NODE_GNUC_AT_LEAST(major, minor, patch)                              \
  (NODE_MAKE_VERSION(major, minor, patch) <=                                  \
      NODE_MAKE_VERSION(__GNUC__, __GNUC_MINOR__, __GNUC_PATCHLEVEL__))
#else
# define NODE_GNUC_AT_LEAST(major, minor, patch) (0)
#endif

#if defined(NODE_WANT_INTERNALS) && NODE_WANT_INTERNALS
# define NODE_DEPRECATED(message, declarator) declarator
#else  // NODE_WANT_INTERNALS
#define NODE_DEPRECATED(message, declarator) [[deprecated(message)]] declarator
#endif

// Forward-declare libuv loop
struct uv_loop_s;
struct napi_module;
struct ssl_ctx_st;  // Forward declaration of SSL_CTX for OpenSSL.

// Forward-declare these functions now to stop MSVS from becoming
// terminally confused when it's done in node_internals.h
namespace node {

struct SnapshotData;

namespace tracing {

class TracingController;

}

NODE_EXTERN v8::Local<v8::Value> ErrnoException(v8::Isolate* isolate,
                                                int errorno,
                                                const char* syscall = nullptr,
                                                const char* message = nullptr,
                                                const char* path = nullptr);
NODE_EXTERN v8::Local<v8::Value> UVException(v8::Isolate* isolate,
                                             int errorno,
                                             const char* syscall = nullptr,
                                             const char* message = nullptr,
                                             const char* path = nullptr,
                                             const char* dest = nullptr);

NODE_DEPRECATED("Use ErrnoException(isolate, ...)",
                inline v8::Local<v8::Value> ErrnoException(
      int errorno,
      const char* syscall = nullptr,
      const char* message = nullptr,
      const char* path = nullptr) {
  return ErrnoException(v8::Isolate::GetCurrent(),
                        errorno,
                        syscall,
                        message,
                        path);
})

NODE_DEPRECATED("Use UVException(isolate, ...)",
                inline v8::Local<v8::Value> UVException(int errorno,
                                        const char* syscall = nullptr,
                                        const char* message = nullptr,
                                        const char* path = nullptr) {
  return UVException(v8::Isolate::GetCurrent(),
                     errorno,
                     syscall,
                     message,
                     path);
})

}  // namespace node

#include <cassert>
#include <cstdint>

#ifndef NODE_STRINGIFY
# define NODE_STRINGIFY(n) NODE_STRINGIFY_HELPER(n)
# define NODE_STRINGIFY_HELPER(n) #n
#endif

#ifdef _WIN32
#if !defined(_SSIZE_T_) && !defined(_SSIZE_T_DEFINED)
typedef intptr_t ssize_t;
# define _SSIZE_T_
# define _SSIZE_T_DEFINED
#endif
#else  // !_WIN32
# include <sys/types.h>  // size_t, ssize_t
#endif  // _WIN32


namespace node {

class IsolateData;
class Environment;
class MultiIsolatePlatform;
class InitializationResultImpl;

namespace ProcessInitializationFlags {
enum Flags : uint32_t {
  kNoFlags = 0,
  // Enable stdio inheritance, which is disabled by default.
  // This flag is also implied by kNoStdioInitialization.
  kEnableStdioInheritance = 1 << 0,
  // Disable reading the NODE_OPTIONS environment variable.
  kDisableNodeOptionsEnv = 1 << 1,
  // Do not parse CLI options.
  kDisableCLIOptions = 1 << 2,
  // Do not initialize ICU.
  kNoICU = 1 << 3,
  // Do not modify stdio file descriptor or TTY state.
  kNoStdioInitialization = 1 << 4,
  // Do not register Node.js-specific signal handlers, reset other signal
  // handlers to default state, or replace the calling thread's signal mask
  // (without this flag, POSIX builds with the inspector set it to block
  // SIGUSR1 and nothing else).
  kNoDefaultSignalHandling = 1 << 5,
  // Do not perform V8 initialization.
  kNoInitializeV8 = 1 << 6,
  // Do not initialize a default Node.js-provided V8 platform instance.
  kNoInitializeNodeV8Platform = 1 << 7,
  // Do not initialize OpenSSL config.
  kNoInitOpenSSL = 1 << 8,
  // Do not initialize Node.js debugging based on environment variables.
  kNoParseGlobalDebugVariables = 1 << 9,
  // Do not adjust OS resource limits for this process.
  kNoAdjustResourceLimits = 1 << 10,
  // Legacy flag for not mapping code segments into large pages for this
  // process. The feature is no longer supported so this is just a no-op.
  kNoUseLargePages = 1 << 11,
  // Skip printing output for --help, --version, --v8-options.
  kNoPrintHelpOrVersionOutput = 1 << 12,
  // Do not perform cppgc initialization. If set, the embedder must call
  // cppgc::InitializeProcess() before creating a Node.js environment
  // and call cppgc::ShutdownProcess() before process shutdown.
  kNoInitializeCppgc = 1 << 13,
  // Initialize the process for predictable snapshot generation.
  kGeneratePredictableSnapshot = 1 << 14,
  // Do not serialize a code cache for builtins that had to be compiled without
  // one. By default such caches are kept so that worker threads created later
  // start faster; an embedder that supplies an EmbedderBuiltinCodeCache or
  // never creates workers only pays for the serialization.
  kNoHarvestBuiltinCodeCache = 1 << 15,

  // Emulate the behavior of InitializeNodeWithArgs() when passing
  // a flags argument to the InitializeOncePerProcess() replacement
  // function.
  kLegacyInitializeNodeWithArgsBehavior =
      kNoStdioInitialization | kNoDefaultSignalHandling | kNoInitializeV8 |
      kNoInitializeNodeV8Platform | kNoInitOpenSSL |
      kNoParseGlobalDebugVariables | kNoAdjustResourceLimits |
      kNoUseLargePages | kNoPrintHelpOrVersionOutput | kNoInitializeCppgc,
};
}  // namespace ProcessInitializationFlags
namespace ProcessFlags = ProcessInitializationFlags;  // Legacy alias.

namespace StopFlags {
enum Flags : uint32_t {
  kNoFlags = 0,
  // Do not explicitly terminate the Isolate
  // when exiting the Environment.
  kDoNotTerminateIsolate = 1 << 0,
};
}  // namespace StopFlags

class NODE_EXTERN InitializationResult {
 public:
  virtual ~InitializationResult() = default;

  // Returns a suggested process exit code.
  virtual int exit_code() const = 0;

  // Returns 'true' if initialization was aborted early due to errors.
  virtual bool early_return() const = 0;

  // Returns the parsed list of non-Node.js arguments.
  virtual const std::vector<std::string>& args() const = 0;

  // Returns the parsed list of Node.js arguments.
  virtual const std::vector<std::string>& exec_args() const = 0;

  // Returns an array of errors. Note that these may be warnings
  // whose existence does not imply a non-zero exit code.
  virtual const std::vector<std::string>& errors() const = 0;

  // If kNoInitializeNodeV8Platform was not specified, the global Node.js
  // platform instance.
  virtual MultiIsolatePlatform* platform() const = 0;

 private:
  InitializationResult() = default;
  friend class InitializationResultImpl;
};

// TODO(addaleax): Officially deprecate this and replace it with something
// better suited for a public embedder API.
NODE_EXTERN int Start(int argc, char* argv[]);

// Tear down Node.js while it is running (there are active handles
// in the loop and / or actively executing JavaScript code).
NODE_EXTERN int Stop(Environment* env,
                     StopFlags::Flags flags = StopFlags::kNoFlags);

// Set up per-process state needed to run Node.js. This will consume arguments
// from args, and return information about the initialization success,
// including the arguments split into argv/exec_argv, a list of potential
// errors encountered during initialization, and a potential suggested
// exit code.
NODE_EXTERN std::shared_ptr<InitializationResult> InitializeOncePerProcess(
    const std::vector<std::string>& args,
    ProcessInitializationFlags::Flags flags =
        ProcessInitializationFlags::kNoFlags);
// Undoes the initialization performed by InitializeOncePerProcess(),
// where cleanup is necessary.
NODE_EXTERN void TearDownOncePerProcess();
// Convenience overload for specifying multiple flags without having
// to worry about casts.
inline std::shared_ptr<InitializationResult> InitializeOncePerProcess(
    const std::vector<std::string>& args,
    std::initializer_list<ProcessInitializationFlags::Flags> list) {
  uint64_t flags_accum = ProcessInitializationFlags::kNoFlags;
  for (const auto flag : list) flags_accum |= static_cast<uint64_t>(flag);
  return InitializeOncePerProcess(
      args, static_cast<ProcessInitializationFlags::Flags>(flags_accum));
}

enum OptionEnvvarSettings {
  // Allow the options to be set via the environment variable, like
  // `NODE_OPTIONS`.
  kAllowedInEnvvar = 0,
  // Disallow the options to be set via the environment variable, like
  // `NODE_OPTIONS`.
  kDisallowedInEnvvar = 1,
};

// Process the arguments and set up the per-process options.
// If the `settings` is set as OptionEnvvarSettings::kAllowedInEnvvar, the
// options that are allowed in the environment variable are processed. Options
// that are disallowed to be set via environment variable are processed as
// errors.
// Otherwise all the options that are disallowed (and those are allowed) to be
// set via environment variable are processed.
NODE_EXTERN int ProcessGlobalArgs(std::vector<std::string>* args,
                      std::vector<std::string>* exec_args,
                      std::vector<std::string>* errors,
                      OptionEnvvarSettings settings);

class NodeArrayBufferAllocator;

// An ArrayBuffer::Allocator class with some Node.js-specific tweaks. If you do
// not have to use another allocator, using this class is recommended:
// - It supports Buffer.allocUnsafe() and Buffer.allocUnsafeSlow() with
//   uninitialized memory.
// - It supports transferring, rather than copying, ArrayBuffers when using
//   MessagePorts.
class NODE_EXTERN ArrayBufferAllocator : public v8::ArrayBuffer::Allocator {
 public:
  // If `always_debug` is true, create an ArrayBuffer::Allocator instance
  // that performs additional integrity checks (e.g. make sure that only memory
  // that was allocated by the it is also freed by it).
  // This can also be set using the --debug-arraybuffer-allocations flag.
  static std::unique_ptr<ArrayBufferAllocator> Create(
      bool always_debug = false);

 private:
  virtual NodeArrayBufferAllocator* GetImpl() = 0;

  friend class IsolateData;
};

// Legacy equivalents for ArrayBufferAllocator::Create().
NODE_EXTERN ArrayBufferAllocator* CreateArrayBufferAllocator();
NODE_EXTERN void FreeArrayBufferAllocator(ArrayBufferAllocator* allocator);

class NODE_EXTERN IsolatePlatformDelegate {
 public:
  virtual std::shared_ptr<v8::TaskRunner> GetForegroundTaskRunner() = 0;
  virtual bool IdleTasksEnabled() = 0;
};

class NODE_EXTERN MultiIsolatePlatform : public v8::Platform {
 public:
  ~MultiIsolatePlatform() override = default;
  // Returns true if work was dispatched or executed. New tasks that are
  // posted during flushing of the queue are postponed until the next
  // flushing.
  virtual bool FlushForegroundTasks(v8::Isolate* isolate) = 0;
  virtual void DrainTasks(v8::Isolate* isolate) = 0;

  // This needs to be called between the calls to `Isolate::Allocate()` and
  // `Isolate::Initialize()`, so that initialization can already start
  // using the platform.
  // When using `NewIsolate()`, this is taken care of by that function.
  // This function may only be called once per `Isolate`.
  virtual void RegisterIsolate(v8::Isolate* isolate,
                               struct uv_loop_s* loop) = 0;
  // This method can be used when an application handles task scheduling on its
  // own through `IsolatePlatformDelegate`. Upon registering an isolate with
  // this overload any other method in this class with the exception of
  // `UnregisterIsolate` *must not* be used on that isolate.
  virtual void RegisterIsolate(v8::Isolate* isolate,
                               IsolatePlatformDelegate* delegate) = 0;

  // This function may only be called once per `Isolate`, and discard any
  // pending delayed tasks scheduled for that isolate.
  // This needs to be called right after calling `Isolate::Dispose()`.
  virtual void UnregisterIsolate(v8::Isolate* isolate) = 0;
  // This disposes, unregisters and frees up an isolate that's allocated using
  // v8::Isolate::Allocate() in the correct order to prevent race conditions.
  void DisposeIsolate(v8::Isolate* isolate);

  // The platform should call the passed function once all state associated
  // with the given isolate has been cleaned up. This can, but does not have to,
  // happen asynchronously.
  virtual void AddIsolateFinishedCallback(v8::Isolate* isolate,
                                          void (*callback)(void*),
                                          void* data) = 0;

  static std::unique_ptr<MultiIsolatePlatform> Create(
      int thread_pool_size,
      v8::TracingController* tracing_controller = nullptr,
      v8::PageAllocator* page_allocator = nullptr);
};

enum IsolateSettingsFlags {
  MESSAGE_LISTENER_WITH_ERROR_LEVEL = 1 << 0,
  DETAILED_SOURCE_POSITIONS_FOR_PROFILING = 1 << 1,
  SHOULD_NOT_SET_PROMISE_REJECTION_CALLBACK = 1 << 2,
  SHOULD_NOT_SET_PREPARE_STACK_TRACE_CALLBACK = 1 << 3,
  SHOULD_NOT_SET_WASM_STREAMING_CALLBACK = 1 << 4,
  ALLOW_MODIFY_CODE_GENERATION_FROM_STRINGS_CALLBACK = 0, /* legacy no-op */
};

struct IsolateSettings {
  uint64_t flags = MESSAGE_LISTENER_WITH_ERROR_LEVEL |
      DETAILED_SOURCE_POSITIONS_FOR_PROFILING;
  v8::MicrotasksPolicy policy = v8::MicrotasksPolicy::kExplicit;

  // Error handling callbacks
  v8::Isolate::AbortOnUncaughtExceptionCallback
      should_abort_on_uncaught_exception_callback = nullptr;
  v8::FatalErrorCallback fatal_error_callback = nullptr;
  v8::OOMErrorCallback oom_error_callback = nullptr;
  v8::PrepareStackTraceCallback prepare_stack_trace_callback = nullptr;

  // Miscellaneous callbacks
  v8::PromiseRejectCallback promise_reject_callback = nullptr;
  v8::AllowWasmCodeGenerationCallback
      allow_wasm_code_generation_callback = nullptr;
  v8::ModifyCodeGenerationFromStringsCallback2
      modify_code_generation_from_strings_callback = nullptr;

  // When the settings is passed to NewIsolate():
  // - If cpp_heap is not nullptr, this CppHeap will be used to create
  //   the isolate and its ownership will be passed to V8.
  // - If this is nullptr, Node.js will create a CppHeap that will be
  //   owned by V8.
  //
  // When the settings is passed to SetIsolateUpForNode():
  // cpp_heap will be ignored. Embedders must ensure that the
  // v8::Isolate has a CppHeap attached while it's still used by
  // Node.js, for example using v8::CreateParams.
  //
  // See https://issues.chromium.org/issues/42203693. In future version
  // of V8, this CppHeap will be created by V8 if not provided.
  v8::CppHeap* cpp_heap = nullptr;
};

// Represents a startup snapshot blob, e.g. created by passing
// --node-snapshot-main=entry.js to the configure script at build time,
// or by running Node.js with the --build-snapshot option.
//
// If used, the snapshot *must* have been built with the same Node.js
// version and V8 flags as the version that is currently running, and will
// be rejected otherwise.
// The same EmbedderSnapshotData instance *must* be passed to both
// `NewIsolate()` and `CreateIsolateData()`. The first `Environment` instance
// should be created with an empty `context` argument and will then
// use the main context included in the snapshot blob. It can be retrieved
// using `GetMainContext()`. `LoadEnvironment` can receive an empty
// `StartExecutionCallback` in this case.
// If V8 was configured with the shared-readonly-heap option, it requires
// all snapshots used to create `Isolate` instances to be identical.
// This option *must* be unset by embedders who wish to use the startup
// feature during the build step by passing the --disable-shared-readonly-heap
// flag to the configure script.
//
// The snapshot *must* be kept alive during the execution of the Isolate
// that was created using it.
//
// Snapshots are an *experimental* feature. In particular, the embedder API
// exposed through this class is subject to change or removal between Node.js
// versions, including possible API and ABI breakage.
class EmbedderSnapshotData {
 public:
  struct DeleteSnapshotData {
    void operator()(const EmbedderSnapshotData*) const;
  };
  using Pointer =
      std::unique_ptr<const EmbedderSnapshotData, DeleteSnapshotData>;

  // Return an EmbedderSnapshotData object that refers to the built-in
  // snapshot of Node.js. This can have been configured through e.g.
  // --node-snapshot-main=entry.js.
  static Pointer BuiltinSnapshotData();

  // Return an EmbedderSnapshotData object that is based on an input file.
  // Calling this method will consume but not close the FILE* handle.
  // The FILE* handle can be closed immediately following this call.
  // If the snapshot is invalid, this returns an empty pointer.
  static Pointer FromFile(FILE* in);
  static Pointer FromBlob(const std::vector<char>& in);
  static Pointer FromBlob(std::string_view in);

  // Write this EmbedderSnapshotData object to an output file.
  // Calling this method will not close the FILE* handle.
  // The FILE* handle can be closed immediately following this call.
  void ToFile(FILE* out) const;
  std::vector<char> ToBlob() const;

  // Returns whether custom snapshots can be used. Currently, this always
  // returns false since V8 enforces shared readonly-heap.
  static bool CanUseCustomSnapshotPerIsolate();

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

 protected:
  EmbedderSnapshotData(const SnapshotData* impl, bool owns_impl);

 private:
  const SnapshotData* impl_;
  bool owns_impl_;
  friend struct SnapshotData;
  friend class CommonEnvironmentSetup;
};

// Overriding IsolateSettings may produce unexpected behavior
// in Node.js core functionality, so proceed at your own risk.
NODE_EXTERN void SetIsolateUpForNode(v8::Isolate* isolate,
                                     const IsolateSettings& settings);

// Set a number of callbacks for the `isolate`, in particular the Node.js
// uncaught exception listener.
NODE_EXTERN void SetIsolateUpForNode(v8::Isolate* isolate);

// Creates a new isolate with Node.js-specific settings.
// This is a convenience method equivalent to using SetIsolateCreateParams(),
// Isolate::Allocate(), MultiIsolatePlatform::RegisterIsolate(),
// Isolate::Initialize(), and SetIsolateUpForNode().
NODE_EXTERN v8::Isolate* NewIsolate(
    ArrayBufferAllocator* allocator,
    struct uv_loop_s* event_loop,
    MultiIsolatePlatform* platform,
    const EmbedderSnapshotData* snapshot_data = nullptr,
    const IsolateSettings& settings = {});
NODE_EXTERN v8::Isolate* NewIsolate(
    std::shared_ptr<ArrayBufferAllocator> allocator,
    struct uv_loop_s* event_loop,
    MultiIsolatePlatform* platform,
    const EmbedderSnapshotData* snapshot_data = nullptr,
    const IsolateSettings& settings = {});

// Creates a new context with Node.js-specific tweaks.
// Call `RegisterContext` after the context been created to register
// the context with Node.js specific setups like the inspector.
NODE_EXTERN v8::Local<v8::Context> NewContext(
    v8::Isolate* isolate,
    v8::Local<v8::ObjectTemplate> object_template =
        v8::Local<v8::ObjectTemplate>());

// Runs Node.js-specific tweaks on an already constructed context
// Return value indicates success of operation
NODE_EXTERN v8::Maybe<bool> InitializeContext(v8::Local<v8::Context> context);

// Associate the context with the given Environment. This registers the context
// as known to Node.js, makes it available to the inspector. This also registers
// Node.js promise hooks on the context.
NODE_EXTERN void RegisterContext(Environment* env,
                                 v8::Local<v8::Context> context,
                                 std::string_view name = "",
                                 std::string_view origin = "");
// Unregister the context. Call this when the embedder finished all work with
// this context.
NODE_EXTERN void UnregisterContext(Environment* env,
                                   v8::Local<v8::Context> context);

// If `platform` is passed, it will be used to register new Worker instances.
// It can be `nullptr`, in which case creating new Workers inside of
// Environments that use this `IsolateData` will not work.
NODE_EXTERN IsolateData* CreateIsolateData(
    v8::Isolate* isolate,
    struct uv_loop_s* loop,
    MultiIsolatePlatform* platform = nullptr,
    ArrayBufferAllocator* allocator = nullptr,
    const EmbedderSnapshotData* snapshot_data = nullptr);
NODE_EXTERN void FreeIsolateData(IsolateData* isolate_data);

struct ThreadId {
  uint64_t id = static_cast<uint64_t>(-1);
};
NODE_EXTERN ThreadId AllocateEnvironmentThreadId();

namespace EnvironmentFlags {
enum Flags : uint64_t {
  kNoFlags = 0,
  // Use the default behaviour for Node.js instances.
  kDefaultFlags = 1 << 0,
  // Controls whether this Environment is allowed to affect per-process state
  // (e.g. cwd, process title, uid, etc.).
  // This is set when using kDefaultFlags.
  kOwnsProcessState = 1 << 1,
  // Set if this Environment instance is associated with the global inspector
  // handling code (i.e. listening on SIGUSR1).
  // This is set when using kDefaultFlags.
  kOwnsInspector = 1 << 2,
  // Set if Node.js should not run its own esm loader. This is needed by some
  // embedders, because it's possible for the Node.js esm loader to conflict
  // with another one in an embedder environment, e.g. Blink's in Chromium.
  kNoRegisterESMLoader = 1 << 3,
  // Set this flag to make Node.js track "raw" file descriptors, i.e. managed
  // by fs.open() and fs.close(), and close them during FreeEnvironment().
  kTrackUnmanagedFds = 1 << 4,
  // Set this flag to force hiding console windows when spawning child
  // processes. This is usually used when embedding Node.js in GUI programs on
  // Windows.
  kHideConsoleWindows = 1 << 5,
  // Set this flag to disable loading native addons via `process.dlopen`.
  // This environment flag is especially important for worker threads
  // so that a worker thread can't load a native addon even if `execArgv`
  // is overwritten and `--no-addons` is not specified but was specified
  // for this Environment instance.
  kNoNativeAddons = 1 << 6,
  // Set this flag to disable searching modules from global paths like
  // $HOME/.node_modules and $NODE_PATH. This is used by standalone apps that
  // do not expect to have their behaviors changed because of globally
  // installed modules.
  kNoGlobalSearchPaths = 1 << 7,
  // Do not export browser globals like setTimeout, console, etc.
  kNoBrowserGlobals = 1 << 8,
  // Controls whether or not the Environment should call V8Inspector::create().
  // This control is needed by embedders who may not want to initialize the V8
  // inspector in situations where one has already been created,
  // e.g. Blink's in Chromium.
  kNoCreateInspector = 1 << 9,
  // Controls whether or not the InspectorAgent for this Environment should
  // call StartDebugSignalHandler. This control is needed by embedders who may
  // not want to allow other processes to start the V8 inspector.
  kNoStartDebugSignalHandler = 1 << 10,
  // Controls whether the InspectorAgent created for this Environment waits for
  // Inspector frontend events during the Environment creation. It's used to
  // call node::Stop(env) on a Worker thread that is waiting for the events.
  kNoWaitForInspectorFrontend = 1 << 11,
  // Set this flag to exempt process._linkedBinding() from the permission
  // model's addon scope (--allow-addons): linked bindings are compiled into
  // the executable by the embedder, unlike addons loaded from the file system
  // through process.dlopen(), which stays gated. Inherited by worker threads.
  kNoAddonPermissionForLinkedBindings = 1 << 12
};
}  // namespace EnvironmentFlags

enum class SnapshotFlags : uint32_t {
  kDefault = 0,
  // Whether code cache should be generated as part of the snapshot.
  // Code cache reduces the time spent on compiling functions included
  // in the snapshot at the expense of a bigger snapshot size and
  // potentially breaking portability of the snapshot.
  kWithoutCodeCache = 1 << 0,
};

struct SnapshotConfig {
  SnapshotFlags flags = SnapshotFlags::kDefault;

  // When builder_script_path is std::nullopt, the snapshot is generated as a
  // built-in snapshot instead of a custom one, and it's expected that the
  // built-in snapshot only contains states that reproduce in every run of the
  // application. The event loop won't be run when generating a built-in
  // snapshot, so asynchronous operations should be avoided.
  //
  // When builder_script_path is an std::string, it should match args[1]
  // passed to CreateForSnapshotting(). The embedder is also expected to use
  // LoadEnvironment() to run a script matching this path. In that case the
  // snapshot is generated as a custom snapshot and the event loop is run, so
  // the snapshot builder can execute asynchronous operations as long as they
  // are run to completion when the snapshot is taken.
  std::optional<std::string> builder_script_path;

  // A V8 startup blob (as produced by V8's mksnapshot) to build the snapshot
  // on top of, instead of setting up the V8 heap from scratch. Needed when
  // the V8 that Node.js is linked against can only deserialize (external
  // startup data), and to keep the result on the same read-only heap lineage
  // as the embedder's other isolates. Caller-owned; must outlive the setup.
  const v8::StartupData* base_blob = nullptr;
};

struct InspectorParentHandle {
  virtual ~InspectorParentHandle() = default;
};

// Code cache for the built-in JavaScript of Environments that are bootstrapped
// rather than deserialized from a snapshot; see SetBuiltinCodeCache().
class NODE_EXTERN EmbedderBuiltinCodeCache {
 public:
  struct Entry {
    std::string id;  // e.g. "internal/bootstrap/node"
    std::unique_ptr<v8::ScriptCompiler::CachedData> data;
  };
  explicit EmbedderBuiltinCodeCache(std::vector<Entry> entries);
  ~EmbedderBuiltinCodeCache();

  // Compiles every built-in module in `context`, which must come from
  // NewContext(), and returns their code caches; empty on failure.
  static std::vector<Entry> Generate(v8::Local<v8::Context> context);

  v8::ScriptCompiler::CachedData::CompatibilityCheckResult CompatibilityCheck(
      v8::Isolate* isolate) const;

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

  struct Impl;

 private:
  std::unique_ptr<Impl> impl_;
  friend NODE_EXTERN v8::ScriptCompiler::CachedData::CompatibilityCheckResult
  SetBuiltinCodeCache(IsolateData*, const EmbedderBuiltinCodeCache*);
};

// Environments created from `isolate_data` afterwards start with `cache`'s
// entries (they share its buffers; `cache` itself may be freed after the call);
// nullptr clears it. Returns the result of `cache->CompatibilityCheck()` and
// leaves `isolate_data` unchanged unless that is kSuccess.
NODE_EXTERN v8::ScriptCompiler::CachedData::CompatibilityCheckResult
SetBuiltinCodeCache(IsolateData* isolate_data,
                    const EmbedderBuiltinCodeCache* cache);

// TODO(addaleax): Maybe move per-Environment options parsing here.
// Returns nullptr when the Environment cannot be created e.g. there are
// pending JavaScript exceptions.
// `context` may be empty if an `EmbedderSnapshotData` instance was provided
// to `NewIsolate()` and `CreateIsolateData()`.
NODE_EXTERN Environment* CreateEnvironment(
    IsolateData* isolate_data,
    v8::Local<v8::Context> context,
    const std::vector<std::string>& args,
    const std::vector<std::string>& exec_args,
    EnvironmentFlags::Flags flags = EnvironmentFlags::kDefaultFlags,
    ThreadId thread_id = {} /* allocates a thread id automatically */,
    std::unique_ptr<InspectorParentHandle> inspector_parent_handle = {},
    std::string_view thread_name = {});

// Returns a handle that can be passed to `LoadEnvironment()`, making the
// child Environment accessible to the inspector as if it were a Node.js Worker.
// `child_thread_id` can be created using `AllocateEnvironmentThreadId()`
// and then later passed on to `CreateEnvironment()` to create the child
// Environment, together with the inspector handle.
// This method should not be called while the parent Environment is active
// on another thread.
NODE_EXTERN std::unique_ptr<InspectorParentHandle> GetInspectorParentHandle(
    Environment* parent_env,
    ThreadId child_thread_id,
    const char* child_url);

NODE_EXTERN std::unique_ptr<InspectorParentHandle> GetInspectorParentHandle(
    Environment* parent_env,
    ThreadId child_thread_id,
    const char* child_url,
    const char* name);

NODE_EXTERN std::unique_ptr<InspectorParentHandle> GetInspectorParentHandle(
    Environment* parent_env,
    ThreadId child_thread_id,
    std::string_view child_url,
    std::string_view name);

struct StartExecutionCallbackInfo {
  v8::Local<v8::Object> process_object;
  v8::Local<v8::Function> native_require;
  v8::Local<v8::Function> run_cjs;
};

enum class ModuleFormat : uint8_t {
  kCommonJS,
  kModule,  // i.e. ES Module/SourceTextModule
  // TODO(joyeecheung): support TypeScriptModule, TypeScriptCommonJS
};

// Information passed to embedder callbacks during environment startup.
// This class is created by Node.js and passed to the embedder's callback.
// The layout is opaque to allow future additions without breaking ABI.
class NODE_EXTERN StartExecutionCallbackInfoWithModule {
 public:
  StartExecutionCallbackInfoWithModule();
  ~StartExecutionCallbackInfoWithModule();

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

  Environment* env() const;
  v8::Local<v8::Object> process_object() const;
  v8::Local<v8::Function> native_require() const;
  v8::Local<v8::Function> run_module() const;

  void set_env(Environment* env);
  void set_process_object(v8::Local<v8::Object> process_object);
  void set_native_require(v8::Local<v8::Function> native_require);
  void set_run_module(v8::Local<v8::Function> run_module);

 private:
  struct Impl;
  std::unique_ptr<Impl> impl_;
};

using StartExecutionCallback =
    std::function<v8::MaybeLocal<v8::Value>(const StartExecutionCallbackInfo&)>;
using StartExecutionCallbackWithModule =
    std::function<v8::MaybeLocal<v8::Value>(
        const StartExecutionCallbackInfoWithModule&)>;
using EmbedderPreloadCallback =
    std::function<void(Environment* env,
                       v8::Local<v8::Value> process,
                       v8::Local<v8::Value> require)>;

// Run initialization for the environment.
//
// The |preload| function, usually used by embedders to inject scripts,
// will be run by Node.js before Node.js executes the entry point.
// The function is guaranteed to run before the user land module loader running
// any user code, so it is safe to assume that at this point, no user code has
// been run yet.
// The function will be executed with preload(process, require), and the passed
// require function has access to internal Node.js modules. There is no
// stability guarantee about the internals exposed to the internal require
// function. Expect breakages when updating Node.js versions if the embedder
// imports internal modules with the internal require function.
// Worker threads created in the environment will also respect The |preload|
// function, so make sure the function is thread-safe.
NODE_EXTERN v8::MaybeLocal<v8::Value> LoadEnvironment(
    Environment* env,
    StartExecutionCallback cb,
    EmbedderPreloadCallback preload = nullptr);

NODE_EXTERN v8::MaybeLocal<v8::Value> LoadEnvironment(
    Environment* env,
    StartExecutionCallbackWithModule cb,
    EmbedderPreloadCallback preload = nullptr);

NODE_EXTERN v8::MaybeLocal<v8::Value> LoadEnvironment(
    Environment* env,
    std::string_view main_script_source_utf8,
    EmbedderPreloadCallback preload = nullptr);

// Data for specifying an entry point script for LoadEnvironment().
// This class uses an opaque layout to allow future additions without
// breaking ABI. Use the setter methods to configure the entry point.
class NODE_EXTERN ModuleData {
 public:
  ModuleData();
  ~ModuleData();

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

  void set_source(std::string_view source);
  void set_format(ModuleFormat format);
  void set_resource_name(std::string_view name);

  std::string_view source() const;
  ModuleFormat format() const;
  std::string_view resource_name() const;

 private:
  struct Impl;
  std::unique_ptr<Impl> impl_;
};

NODE_EXTERN v8::MaybeLocal<v8::Value> LoadEnvironment(
    Environment* env,
    const ModuleData* entry_point,
    EmbedderPreloadCallback preload = nullptr);

// Runs `env`'s event loop until its handles have closed, with JavaScript
// execution disallowed on the isolate; see doc/api/embedding.md if that loop
// is shared with other Environments.
NODE_EXTERN void FreeEnvironment(Environment* env);

// Set a callback that is called when process.exit() is called from JS,
// overriding the default handler.
// It receives the Environment* instance and the exit code as arguments.
// This could e.g. call Stop(env); in order to terminate execution and stop
// the event loop.
// The default handler disposes of the global V8 platform instance, if one is
// being used, and calls exit().
NODE_EXTERN void SetProcessExitHandler(
    Environment* env,
    std::function<void(Environment*, int)>&& handler);
NODE_EXTERN void DefaultProcessExitHandler(Environment* env, int exit_code);

// Sets a process-global handler invoked when Node.js programmatically aborts.
// Nullable strings representing the location and reason for the abort may or
// may not be passed as a parameter to the handler. The handler should not
// return, but node will ensure that the process exits after the handler is
// called regardless of whether or not it returns. Passing nullptr restores the
// default handler. This is process-global and may be invoked before any Isolate
// or Environment exists.
using AbortHandler = void (*)(const char* location, const char* message);
NODE_EXTERN void SetAbortHandler(AbortHandler handler);

// This may return nullptr if context is not associated with a Node instance.
NODE_EXTERN Environment* GetCurrentEnvironment(v8::Local<v8::Context> context);
NODE_EXTERN IsolateData* GetEnvironmentIsolateData(Environment* env);
NODE_EXTERN ArrayBufferAllocator* GetArrayBufferAllocator(IsolateData* data);
// This is mostly useful for Environment* instances that were created through
// a snapshot and have a main context that was read from that snapshot.
NODE_EXTERN v8::Local<v8::Context> GetMainContext(Environment* env);

[[noreturn]] NODE_EXTERN void OnFatalError(const char* location,
                                           const char* message);
NODE_EXTERN void PromiseRejectCallback(v8::PromiseRejectMessage message);
NODE_EXTERN bool AllowWasmCodeGenerationCallback(v8::Local<v8::Context> context,
                                            v8::Local<v8::String>);
NODE_EXTERN bool ShouldAbortOnUncaughtException(v8::Isolate* isolate);
NODE_EXTERN v8::MaybeLocal<v8::Value> PrepareStackTraceCallback(
    v8::Local<v8::Context> context,
    v8::Local<v8::Value> exception,
    v8::Local<v8::Array> trace);

// Writes a diagnostic report to a file. If filename is not provided, the
// default filename includes the date, time, PID, and a sequence number.
// The report's JavaScript stack trace is taken from err, if present.
// If isolate is nullptr, no information about the JavaScript environment
// is included in the report.
// Returns the filename of the written report.
NODE_EXTERN std::string TriggerNodeReport(v8::Isolate* isolate,
                                          std::string_view message,
                                          std::string_view trigger,
                                          std::string_view filename,
                                          v8::Local<v8::Value> error);
NODE_EXTERN std::string TriggerNodeReport(Environment* env,
                                          std::string_view message,
                                          std::string_view trigger,
                                          std::string_view filename,
                                          v8::Local<v8::Value> error);
NODE_EXTERN void GetNodeReport(v8::Isolate* isolate,
                               std::string_view message,
                               std::string_view trigger,
                               v8::Local<v8::Value> error,
                               std::ostream& out);
NODE_EXTERN void GetNodeReport(Environment* env,
                               std::string_view message,
                               std::string_view trigger,
                               v8::Local<v8::Value> error,
                               std::ostream& out);

// This returns the MultiIsolatePlatform used for an Environment or IsolateData
// instance, if one exists.
NODE_EXTERN MultiIsolatePlatform* GetMultiIsolatePlatform(Environment* env);
NODE_EXTERN MultiIsolatePlatform* GetMultiIsolatePlatform(IsolateData* env);

// Get/set the currently active tracing controller. Using
// MultiIsolatePlatform::Create() will implicitly set this by default. This is
// global and should be initialized along with the v8::Platform instance that is
// being used. `controller` is allowed to be `nullptr`. This is used for tracing
// events from Node.js itself. V8 uses the tracing controller returned from the
// active `v8::Platform` instance.
NODE_EXTERN v8::TracingController* GetTracingController();
NODE_EXTERN void SetTracingController(v8::TracingController* controller);

// Run `process.emit('beforeExit')` as it would usually happen when Node.js is
// run in standalone mode.
NODE_EXTERN v8::Maybe<bool> EmitProcessBeforeExit(Environment* env);
// Run `process.emit('exit')` as it would usually happen when Node.js is run
// in standalone mode. The return value corresponds to the exit code.
NODE_EXTERN v8::Maybe<int> EmitProcessExit(Environment* env);

// Runs hooks added through `AtExit()`. This is part of `FreeEnvironment()`,
// so calling it manually is typically not necessary.
NODE_EXTERN void RunAtExit(Environment* env);

// This may return nullptr if the current v8::Context is not associated
// with a Node instance.
NODE_EXTERN struct uv_loop_s* GetCurrentEventLoop(v8::Isolate* isolate);

// Runs the main loop for a given Environment. This roughly performs the
// following steps:
// 1. Call uv_run() on the event loop until it is drained.
// 2. Call platform->DrainTasks() on the associated platform/isolate.
//   3. If the event loop is alive again, go to Step 1.
// 4. Call EmitProcessBeforeExit().
//   5. If the event loop is alive again, go to Step 1.
// 6. Call EmitProcessExit() and forward the return value.