修改函数hook的js去打印参数值

对于之前的需求：frida-trace时，打印其中特定的某个ObjC函数的参数

之前不知道如何解决，后来参考这里，突然想到：

倒是可以借助其所说的，对于frida-trace自动为每个类的函数，所生成的js文件：

• 位置：__handlers__/{ClassName}/{FunctionName}.js

去修改js代码，加上打印对应的args的代码，即可打印对应参数值了。

举例

-[AAAccountManager addAccount:]

frida-trace为函数-[AAAccountManager addAccount:]自动生成的：

• js文件
  • /Users/crifan/dev/dev_root/iosReverse/AppleStore/AuthKit_akd/dynamicDebug/frida/scripts/__handlers__/AAAccountManager/addAccount_.js
    • 

• 完整js代码

  /*
  * Auto-generated by Frida. Please modify to match the signature of -[AAAccountManager addAccount:].
  * This stub is currently auto-generated from manpages when available.
  *
  * For full API reference, see: https://frida.re/docs/javascript-api/
  */
  
  {
    /**
      * Called synchronously when about to call -[AAAccountManager addAccount:].
    *
    * @this {object} - Object allowing you to store state for use in onLeave.
    * @param {function} log - Call this function with a string to be presented to the user.
    * @param {array} args - Function arguments represented as an array of NativePointer objects.
    * For example use args[0].readUtf8String() if the first argument is a pointer to a C string encoded as UTF-8.
    * It is also possible to modify arguments by assigning a NativePointer object to an element of this array.
    * @param {object} state - Object allowing you to keep state across function calls.
    * Only one JavaScript function will execute at a time, so do not worry about race-conditions.
    * However, do not use this to store function arguments across onEnter/onLeave, but instead
    * use "this" which is an object for keeping state local to an invocation.
    */
    onEnter(log, args, state) {
      log(`-[AAAccountManager addAccount:${args[2]}]`);
    },
  
    /**
      * Called synchronously when about to return from -[AAAccountManager addAccount:].
    *
    * See onEnter for details.
    *
    * @this {object} - Object allowing you to access state stored in onEnter.
    * @param {function} log - Call this function with a string to be presented to the user.
    * @param {NativePointer} retval - Return value represented as a NativePointer object.
    * @param {object} state - Object allowing you to keep state across function calls.
    */
    onLeave(log, retval, state) {
    }
  }
  

可以拷贝把其中的：

log(`-[AAAccountManager addAccount:${args[2]}]`);

改为：

log(`-[AAAccountManager addAccount:${new ObjC.Object(args[2])}]`);

就可以：打印出ObjC对象的信息了，而不仅仅是：ptr=NativePointer的指针的字符串