当我尝试在V8 - JavaScript中编译c++时，出现了许多错误

Many erros when i try compile c++ in V8 - JavaScript

本文关键字：c++ 错误 许多 编译 V8 JavaScript      更新时间：2023-09-26

我试着使用:

git clone git://github.com/v8/v8.git v8 && cd v8 or svn checkout http://v8.googlecode.com/svn/trunk/ v8

使用填词:

make dependencies
sudo apt-get install apt-file;
sudo apt-get install libc6-dev-i368 lib32stdc++6;

当我尝试编译一个简单的文件为:

int main(int argc, char* argv[]) {
  // Create a string containing the JavaScript source code.
  String source = String::New("'Hello' + ', World'");
  // Compile the source code.
  Script script = Script::Compile(source);
  // Run the script to get the result.
  Value result = script->Run();
  // Convert the result to an ASCII string and print it.
  String::AsciiValue ascii(result);
  printf("%s'n", *ascii);
  return 0;
}

命令使用:

g++ test.cpp -Ideps/v8/include -Ldeps/v8/ -lv8 -lpthread

我得到以下错误输出:

v8/src/
test.cpp: Na função ‘int main(int, char**)’:
test.cpp:4:3: error: ‘String’ was not declared in this scope
test.cpp:4:10: error: expected ‘;’ before ‘source’
test.cpp:7:3: error: ‘Script’ was not declared in this scope
test.cpp:7:10: error: expected ‘;’ before ‘script’
test.cpp:10:3: error: ‘Value’ was not declared in this scope
test.cpp:10:9: error: expected ‘;’ before ‘result’
test.cpp:13:3: error: ‘String’ is not a class or namespace
test.cpp:13:22: error: expected ‘;’ before ‘ascii’
test.cpp:14:19: error: ‘ascii’ was not declared in this scope
test.cpp:14:24: error: ‘printf’ was not declared in this scope

有什么问题吗?有人能给我指个正确的方向吗?

根据@Sim的回答，以下是工作版本。

#include "v8.h"
using namespace v8;

int main(int argc, char* argv[]) 
{
  // Get the default Isolate created at startup.
  Isolate* isolate = Isolate::GetCurrent();
  // Create a stack-allocated handle scope.
  HandleScope handle_scope(isolate);
  // Create a new context.
  Handle<Context> context = Context::New(isolate);
  // Here's how you could create a Persistent handle to the context, if needed.
  Persistent<Context> persistent_context(isolate, context);
  // Enter the created context for compiling and
  // running the hello world script. 
  Context::Scope context_scope(context);
  // Create a string containing the JavaScript source code.
  Local<String> source = String::New("'Hello' + ', World'");
  // Compile the source code.
  Local<Script> script = Script::Compile(source);
  // Run the script to get the result.
  Local<Value> result = script->Run();
  // Convert the result to an ASCII string and print it.
  String::AsciiValue ascii(result);
  printf("%s'n", *ascii);
  return 0;
}

要编译和运行它，假设../include中有v8头文件，../lib中有v8库

g++ -L../lib -I../include hello.cc -o a.out -lv8_base.x64 -lv8_snapshot -lpthread && ./a.out

您尝试编译的c++代码是V8"入门"指南中的部分示例("伪代码")。它不能像现在这样工作。下面同一文档中说明了运行该程序所需的操作:

  1. 包含V8 .h头文件，并将项目链接到静态(或共享)V8库。
  2. 导入v8命名空间(using namespace v8);
  3. 获取默认隔离(Isolate::GetCurrent())的引用/指针。
  4. 为本地句柄创建一个HandleScope
  5. 创建并进入V8执行上下文。
  6. 只有这样你才能使用类似于上面的代码。

详细信息请参考V8入门指南

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