3

假设我有这个代码：

Local<Script> script = Script::Compile(String::New("x1 = 1;"), String::New("main.js"));
printf("before run\n");
script->Run();
printf("after run\n");

上下文是之前创建和输入的。
这段代码的输出是：

before run
after run

正如预期的那样。source但是，如果将一些包含语法错误（例如， ）的javascript 代码放入其中，".x11 = 1"则输出为：

main.js:0: Uncaught SyntaxError: Unexpected token .
before execution.
Segmentation fault (core dumped)

如果编译有错误，也许我不应该打电话Run，但如何检查呢？

另外：（来自Getting Starget 的代码 - Chrome V8 + 有语法错误的代码 = 相同的东西）

#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.  

Handle<String> source = String::New(".>make.some.syntax.errors<");  

// Compile the source code.  

Handle<Script> script = Script::Compile(source);  

// Run the script to get the result.  

Handle<Value> result = script->Run(); 

// The persistent handle needs to be eventually disposed.  

persistent_context.Dispose();  

// Convert the result to an ASCII string and print it.  

String::AsciiValue ascii(result);  

printf("%s\n", *ascii);  

return 0;

}
4

2 回答 2

1

经过一段时间的头痛后，我找到了解决方法。

当脚本编译失败时，它不会返回任何内容v8::Handle。因此，在这种情况下，script.IsEmpty()返回 true。

为了说明这一点，我对 Google 的 Hello World 代码进行了一些修改：

#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.  

Handle<String> source = String::New(".>no.matter.what.code.is<");  

// Compile the source code.  

Handle<Script> script = Script::Compile(source);  
if(!script.IsEmpty()) // is script compiled ?
{
  // Run the script to get the result.  

  Handle<Value> result = script->Run(); 

  // Convert the result to an ASCII string and print it.  
  String::AsciiValue ascii(result);  

  printf("%s\n", *ascii);  
}

// The persistent handle needs to be eventually disposed.  

persistent_context.Dispose();      

return 0;

}
于 2013-10-27T15:38:38.473 回答
0

基于samples/process.cc的v8源代码：

  // catch any exceptions the script might throw.
  TryCatch try_catch(GetIsolate());

  // Compile the script and check for errors.
  Local<Script> compiled_script;
  if (!Script::Compile(context, script).ToLocal(&compiled_script)) {
    String::Utf8Value error(GetIsolate(), try_catch.Exception());
    Log(*error);
    // The script failed to compile; bail out.
    return false;
  }

  // Run the script!
  Local<Value> result;
  if (!compiled_script->Run(context).ToLocal(&result)) {
    // The TryCatch above is still in effect and will have caught the error.
    String::Utf8Value error(GetIsolate(), try_catch.Exception());
    Log(*error);
    // Running the script failed; bail out.
    return false;
  }

我希望这会有所帮助。

于 2020-03-08T03:09:30.377 回答