denoland-deno/src/binding.cc

/*
Copyright 2018 Ryan Dahl <ry@tinyclouds.org>. All rights reserved.

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.
*/
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <string>

#include "third_party/v8/include/libplatform/libplatform.h"
#include "third_party/v8/include/v8.h"
#include "third_party/v8/src/base/logging.h"

#include "deno.h"
#include "internal.h"

namespace deno {

// Extracts a C string from a v8::V8 Utf8Value.
const char* ToCString(const v8::String::Utf8Value& value) {
  return *value ? *value : "<string conversion failed>";
}

static inline v8::Local<v8::String> v8_str(const char* x) {
  return v8::String::NewFromUtf8(v8::Isolate::GetCurrent(), x,
                                 v8::NewStringType::kNormal)
      .ToLocalChecked();
}

void HandleException(v8::Local<v8::Context> context,
                     v8::Local<v8::Value> exception) {
  auto* isolate = context->GetIsolate();
  Deno* d = static_cast<Deno*>(isolate->GetData(0));
  v8::HandleScope handle_scope(isolate);
  v8::Context::Scope context_scope(context);

  auto message = v8::Exception::CreateMessage(isolate, exception);
  auto onerrorStr = v8::String::NewFromUtf8(isolate, "onerror");
  auto onerror = context->Global()->Get(onerrorStr);
  auto stack_trace = message->GetStackTrace();
  auto line =
      v8::Integer::New(isolate, message->GetLineNumber(context).FromJust());
  auto column =
      v8::Integer::New(isolate, message->GetStartColumn(context).FromJust());

  if (onerror->IsFunction()) {
    // window.onerror is set so we try to handle the exception in javascript.
    auto func = v8::Local<v8::Function>::Cast(onerror);
    v8::Local<v8::Value> args[5];
    args[0] = exception->ToString();
    args[1] = message->GetScriptResourceName();
    args[2] = line;
    args[3] = column;
    args[4] = exception;
    func->Call(context->Global(), 5, args);
    /* message, source, lineno, colno, error */
  } else if (!stack_trace.IsEmpty()) {
    // No javascript onerror handler, but we do have a stack trace. Format it
    // into a string and add to last_exception.
    std::string msg;
    v8::String::Utf8Value exceptionStr(isolate, exception);
    msg += ToCString(exceptionStr);
    msg += "\n";

    for (int i = 0; i < stack_trace->GetFrameCount(); ++i) {
      auto frame = stack_trace->GetFrame(i);
      v8::String::Utf8Value script_name(isolate, frame->GetScriptName());
      int l = frame->GetLineNumber();
      int c = frame->GetColumn();
      char buf[512];
      snprintf(buf, sizeof(buf), "%s %d:%d\n", ToCString(script_name), l, c);
      msg += buf;
    }
    d->last_exception = msg;
  } else {
    // No javascript onerror handler, no stack trace. Format the little info we
    // have into a string and add to last_exception.
    v8::String::Utf8Value exceptionStr(isolate, exception);
    v8::String::Utf8Value script_name(isolate,
                                      message->GetScriptResourceName());
    v8::String::Utf8Value line_str(isolate, line);
    v8::String::Utf8Value col_str(isolate, column);
    char buf[512];
    snprintf(buf, sizeof(buf), "%s\n%s %s:%s\n", ToCString(exceptionStr),
             ToCString(script_name), ToCString(line_str), ToCString(col_str));
    d->last_exception = std::string(buf);
  }
}

/*
bool AbortOnUncaughtExceptionCallback(v8::Isolate* isolate) {
  return true;
}

void MessageCallback2(Local<Message> message, v8::Local<v8::Value> data) {
  printf("MessageCallback2\n\n");
}

void FatalErrorCallback2(const char* location, const char* message) {
  printf("FatalErrorCallback2\n");
}
*/

void ExitOnPromiseRejectCallback(
    v8::PromiseRejectMessage promise_reject_message) {
  auto* isolate = v8::Isolate::GetCurrent();
  Deno* d = static_cast<Deno*>(isolate->GetData(0));
  DCHECK_EQ(d->isolate, isolate);
  v8::HandleScope handle_scope(d->isolate);
  auto exception = promise_reject_message.GetValue();
  auto context = d->context.Get(d->isolate);
  HandleException(context, exception);
}

void Print(const v8::FunctionCallbackInfo<v8::Value>& args) {
  CHECK_EQ(args.Length(), 1);
  auto* isolate = args.GetIsolate();
  v8::HandleScope handle_scope(isolate);
  v8::String::Utf8Value str(isolate, args[0]);
  const char* cstr = ToCString(str);
  printf("%s\n", cstr);
  fflush(stdout);
}

static v8::Local<v8::Uint8Array> ImportBuf(v8::Isolate* isolate, deno_buf buf) {
  auto ab = v8::ArrayBuffer::New(
      isolate, reinterpret_cast<void*>(buf.alloc_ptr), buf.alloc_len,
      v8::ArrayBufferCreationMode::kInternalized);
  auto view =
      v8::Uint8Array::New(ab, buf.data_ptr - buf.alloc_ptr, buf.data_len);
  return view;
}

static deno_buf ExportBuf(v8::Isolate* isolate,
                          v8::Local<v8::ArrayBufferView> view) {
  auto ab = view->Buffer();
  auto contents = ab->Externalize();

  deno_buf buf;
  buf.alloc_ptr = reinterpret_cast<uint8_t*>(contents.Data());
  buf.alloc_len = contents.ByteLength();
  buf.data_ptr = buf.alloc_ptr + view->ByteOffset();
  buf.data_len = view->ByteLength();

  // Prevent JS from modifying buffer contents after exporting.
  ab->Neuter();

  return buf;
}

static void FreeBuf(deno_buf buf) { free(buf.alloc_ptr); }

// Sets the recv callback.
void Recv(const v8::FunctionCallbackInfo<v8::Value>& args) {
  v8::Isolate* isolate = args.GetIsolate();
  Deno* d = reinterpret_cast<Deno*>(isolate->GetData(0));
  DCHECK_EQ(d->isolate, isolate);

  v8::HandleScope handle_scope(isolate);

  if (!d->recv.IsEmpty()) {
    isolate->ThrowException(v8_str("deno.recv already called."));
    return;
  }

  v8::Local<v8::Value> v = args[0];
  CHECK(v->IsFunction());
  v8::Local<v8::Function> func = v8::Local<v8::Function>::Cast(v);

  d->recv.Reset(isolate, func);
}

void Send(const v8::FunctionCallbackInfo<v8::Value>& args) {
  v8::Isolate* isolate = args.GetIsolate();
  Deno* d = static_cast<Deno*>(isolate->GetData(0));
  DCHECK_EQ(d->isolate, isolate);

  v8::Locker locker(d->isolate);
  v8::EscapableHandleScope handle_scope(isolate);

  CHECK_EQ(args.Length(), 1);
  v8::Local<v8::Value> ab_v = args[0];
  CHECK(ab_v->IsArrayBufferView());
  auto buf = ExportBuf(isolate, v8::Local<v8::ArrayBufferView>::Cast(ab_v));

  DCHECK_EQ(d->currentArgs, nullptr);
  d->currentArgs = &args;

  d->cb(d, buf);

  // Buffer is only valid until the end of the callback.
  // TODO(piscisaureus):
  //   It's possible that data in the buffer is needed after the callback
  //   returns, e.g. when the handler offloads work to a thread pool, therefore
  //   make the callback responsible for releasing the buffer.
  FreeBuf(buf);

  d->currentArgs = nullptr;
}

bool Execute(v8::Local<v8::Context> context, const char* js_filename,
             const char* js_source) {
  auto* isolate = context->GetIsolate();
  v8::Isolate::Scope isolate_scope(isolate);
  v8::HandleScope handle_scope(isolate);

  v8::Context::Scope context_scope(context);

  v8::TryCatch try_catch(isolate);

  auto name = v8_str(js_filename);
  auto source = v8_str(js_source);

  v8::ScriptOrigin origin(name);

  auto script = v8::Script::Compile(context, source, &origin);

  if (script.IsEmpty()) {
    DCHECK(try_catch.HasCaught());
    HandleException(context, try_catch.Exception());
    return false;
  }

  auto result = script.ToLocalChecked()->Run(context);

  if (result.IsEmpty()) {
    DCHECK(try_catch.HasCaught());
    HandleException(context, try_catch.Exception());
    return false;
  }

  return true;
}

void InitializeContext(v8::Isolate* isolate, v8::Local<v8::Context> context,
                       const char* js_filename, const char* js_source) {
  v8::HandleScope handle_scope(isolate);
  v8::Context::Scope context_scope(context);

  auto global = context->Global();

  auto deno_val = v8::Object::New(isolate);
  CHECK(global->Set(context, deno::v8_str("deno"), deno_val).FromJust());

  auto print_tmpl = v8::FunctionTemplate::New(isolate, Print);
  auto print_val = print_tmpl->GetFunction(context).ToLocalChecked();
  CHECK(deno_val->Set(context, deno::v8_str("print"), print_val).FromJust());

  auto recv_tmpl = v8::FunctionTemplate::New(isolate, Recv);
  auto recv_val = recv_tmpl->GetFunction(context).ToLocalChecked();
  CHECK(deno_val->Set(context, deno::v8_str("recv"), recv_val).FromJust());

  auto send_tmpl = v8::FunctionTemplate::New(isolate, Send);
  auto send_val = send_tmpl->GetFunction(context).ToLocalChecked();
  CHECK(deno_val->Set(context, deno::v8_str("send"), send_val).FromJust());

  bool r = Execute(context, js_filename, js_source);
  CHECK(r);
}

void AddIsolate(Deno* d, v8::Isolate* isolate) {
  d->isolate = isolate;
  // Leaving this code here because it will probably be useful later on, but
  // disabling it now as I haven't got tests for the desired behavior.
  // d->isolate->SetCaptureStackTraceForUncaughtExceptions(true);
  // d->isolate->SetAbortOnUncaughtExceptionCallback(AbortOnUncaughtExceptionCallback);
  // d->isolate->AddMessageListener(MessageCallback2);
  // d->isolate->SetFatalErrorHandler(FatalErrorCallback2);
  d->isolate->SetPromiseRejectCallback(deno::ExitOnPromiseRejectCallback);
  d->isolate->SetData(0, d);
}

}  // namespace deno

extern "C" {

void deno_init() {
  // v8::V8::InitializeICUDefaultLocation(argv[0]);
  // v8::V8::InitializeExternalStartupData(argv[0]);
  auto* p = v8::platform::CreateDefaultPlatform();
  v8::V8::InitializePlatform(p);
  v8::V8::Initialize();
}

const char* deno_v8_version() { return v8::V8::GetVersion(); }

// TODO(ry) Remove these when we call deno_reply_start from Rust.
static char** global_argv;
static int global_argc;
char** deno_argv() { return global_argv; }
int deno_argc() { return global_argc; }

void deno_set_flags(int* argc, char** argv) {
  v8::V8::SetFlagsFromCommandLine(argc, argv, true);
  // TODO(ry) Remove these when we call deno_reply_start from Rust.
  global_argc = *argc;
  global_argv = reinterpret_cast<char**>(malloc(*argc * sizeof(char*)));
  for (int i = 0; i < *argc; i++) {
    global_argv[i] = strdup(argv[i]);
  }
}

const char* deno_last_exception(Deno* d) { return d->last_exception.c_str(); }

int deno_execute(Deno* d, const char* js_filename, const char* js_source) {
  auto* isolate = d->isolate;
  v8::Locker locker(isolate);
  v8::Isolate::Scope isolate_scope(isolate);
  v8::HandleScope handle_scope(isolate);
  auto context = d->context.Get(d->isolate);
  return deno::Execute(context, js_filename, js_source) ? 1 : 0;
}

int deno_send(Deno* d, deno_buf buf) {
  v8::Locker locker(d->isolate);
  v8::Isolate::Scope isolate_scope(d->isolate);
  v8::HandleScope handle_scope(d->isolate);

  auto context = d->context.Get(d->isolate);
  v8::Context::Scope context_scope(context);

  v8::TryCatch try_catch(d->isolate);

  auto recv = d->recv.Get(d->isolate);
  if (recv.IsEmpty()) {
    d->last_exception = "deno.recv has not been called.";
    return 0;
  }

  v8::Local<v8::Value> args[1];
  args[0] = deno::ImportBuf(d->isolate, buf);
  recv->Call(context->Global(), 1, args);

  if (try_catch.HasCaught()) {
    deno::HandleException(context, try_catch.Exception());
    return 0;
  }

  return 1;
}

void deno_set_response(Deno* d, deno_buf buf) {
  auto ab = deno::ImportBuf(d->isolate, buf);
  d->currentArgs->GetReturnValue().Set(ab);
}

void deno_delete(Deno* d) {
  d->isolate->Dispose();
  delete d;
}

void deno_terminate_execution(Deno* d) { d->isolate->TerminateExecution(); }

}  // extern "C"