v8-print-hello.cpp

// Copyright 2015 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.

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

#include "libplatform/libplatform.h"
#include "v8-context.h"
#include "v8-initialization.h"
#include "v8-isolate.h"
#include "v8-local-handle.h"
#include "v8-primitive.h"
#include "v8-script.h"
#include "v8.h"

void Print(const v8::FunctionCallbackInfo<v8::Value> &args)
{
  bool first = true;
  for (int i = 0; i < args.Length(); i++)
  {
    v8::HandleScope handle_scope(args.GetIsolate());
    if (first)
    {
      first = false;
    }
    else
    {
      printf(" ");
    }
    v8::String::Utf8Value str(args.GetIsolate(), args[i]);

    printf("%s", *str);
  }
  printf("\n");
  fflush(stdout);
}

v8::Local<v8::Context> CreateContext(v8::Isolate *isolate)
{
  // Create a template for the global object.
  v8::Local<v8::ObjectTemplate> global = v8::ObjectTemplate::New(isolate);
  // Bind the global 'print' function to the C++ Print callback.

  global->Set(isolate, "print", v8::FunctionTemplate::New(isolate, Print));

  // Create a new context.
  return v8::Context::New(isolate, NULL, global);
}

int main(int argc, char *argv[])
{
  // Initialize V8.
  v8::V8::InitializeICUDefaultLocation(argv[0]);
  v8::V8::InitializeExternalStartupData(argv[0]);
  std::unique_ptr<v8::Platform> platform = v8::platform::NewDefaultPlatform();
  v8::V8::InitializePlatform(platform.get());
  v8::V8::Initialize();

  // Create a new Isolate and make it the current one.
  v8::Isolate::CreateParams create_params;
  create_params.array_buffer_allocator =
      v8::ArrayBuffer::Allocator::NewDefaultAllocator();
  v8::Isolate *isolate = v8::Isolate::New(create_params);
  {
    v8::Isolate::Scope isolate_scope(isolate);

    // Create a stack-allocated handle scope.
    v8::HandleScope handle_scope(isolate);
    
    // Create a new context.
    v8::Local<v8::Context> context = CreateContext(isolate);
    
    // Enter the context for compiling and running the hello world script.
    v8::Context::Scope context_scope(context);

    {
      // Create a string containing the JavaScript source code.
      v8::Local<v8::String> source =
          v8::String::NewFromUtf8Literal(isolate, "print('Hello, World!...');");

      // Compile the source code.
      v8::Local<v8::Script> script =
          v8::Script::Compile(context, source).ToLocalChecked();

      // Run the script to get the result.
      v8::Local<v8::Value> result = script->Run(context).ToLocalChecked();

      // Convert the result to an UTF8 string and print it.
      v8::String::Utf8Value utf8(isolate, result);
      // printf("%s\n", *utf8);
    }
  }

  // Dispose the isolate and tear down V8.
  isolate->Dispose();
  v8::V8::Dispose();
  v8::V8::DisposePlatform();
  delete create_params.array_buffer_allocator;
  return 0;
}