Attach debugger to existing process?

Support
1

Moved from GitHub:

Is this feature supported?

2

Dear Adrian,

it is possible to start an application from Xcode and attach a JDWP debugger after it launched.

For simulator:

  1. Open the Xcode project
  2. Open the Scheme editor
  3. In the “Run” section go to the “Arguments” tab and add the following arg:
-Xrunjdwp:transport=dt_socket,server=y,suspend=y,address=5005

(if you don’t want the application to wait for the debugger to connect, then use suspend=n)
4. Launch the application from Xcode
5. Create a “Remote” run configuration in Android Studio
6. Set it up to connect to the port specified above (5005)

Note: when using suspend=y, JDWP needs to connect quickly (less than about 30s), otherwise iOS might kill the app.

For devices:

  1. Do the same as for the simulator until (including) step 4.
  2. Open terminal and type
cd ~/.moe/moe-sdk-1.1.0/tools/
java -jar ios-device.jar --debug=5005
  1. Continue from step 5.

If you need the other way around, attaching Xcode to an already running MOE application (which was launched from MOE’s launcher), that is unsupported.

2 Likes
3

Is it possible to attach debugger to the app started from the Java IDE?

4

No, you should start the app from Xcode with custom command line args to wait for the Java debugger to attach.

The other way around is currently unsupported.

EDIT: I assumed, that you wanted to attach an Xcode debugger to the running process. To attach a Java debugger, you would have to make sure that the Java debugger is initialized (e.g. change the main.cpp accordingly), but it does not wait for a debugger to attach, only listen for connections on a specified port.

Then you could attach to that port using a remote debugger configuration.
For debugging on devices, you will have to set up a port proxy, like above.

5

Thank you Gergely. I am looking for the Java debugger.
Could you please enlighten me a bit more on changing main.cpp for initializing Java debugger?

6

As far as I understand this needs to be in the command line before JVM starts:
-Xrunjdwp:transport=dt_socket,server=y,suspend=y,address=5005

7

Right, that code is called from the IDE plugin, so I have to modify the argv passed to moevm in main.cpp below. Unfortunately that is beyond my C/C++ skills… :confused:

int main(int argc, char *argv[]) {
    return moevm(argc, argv);
}
8

Here is a sample

http://cpp.sh/8klf

1 Like
9

Actually, this should work from IDE run config program arguments, but it does not now. I created an issue to track this:

https://github.com/multi-os-engine/multi-os-engine/issues/85

This only relates to launching from Java IDE. Launching from Xcode like this works as intended.

10

I see there were some changes in 1.3.0 on this respect.

How’s the best way to use the debugger for an iOS app as of today?

Thanks in advance,