fix cpp task labels and ensure they can be run

[elaihau]

This pull request fixes the following problems:

• cpp task labels are displayed as "undefined: xxxx" and it is wrong
• Theia always fails to run tasks defined in cpp extension. When they are started from the "Run Task", users either get "launch config not found" error, or an exception that says "Error attaching to terminal".

fixed #6204

How to test

1. define cpp build task(s) in the preference editor
2. open the "Terminal -> Run Task" from top menu bar and check if the task label(s) are correct
3. start the defined cpp build task(s) to check if they can be run

Review checklist

• as an author, I have thoroughly tested my changes and carefully followed the review guidelines

[vince-fugnitto]

It works well for me, I do not see undefined as a title any longer, and the tasks themselves can now execute successfully! 👍 I verified existing tasks in tasks/test-resources and they work correctly as well.

I'll let @lmcbout try it out as well.

[lmcbout]

Question 1:
When I run a task from "tasks.json" you ask for the "problem matcher" configuration, then you adjust it in the "tasks.json" file. So for the next run, no question asked.
When I create a task from the preference ( cpp.buildConfigurations ), it is created as a "Detected task", but when calling "Terminal -> Run task", you keep asking which "problem matcher" to use, you don't save the information inside the preference setting, is it supposed to work like this ?

Question 2:
From the "Quick menu item" for the detected task, you have the "settings button" at the end of the line, but nothing happen for the detected task when selecting it, is it normal? For a task define in "tasks.json", you open the file "tasks.json" so should we open the preference setting for the detected task ?

[vince-fugnitto]

Question 1:
When I run a task from "tasks.json" you ask for the "problem matcher" configuration, then you adjust it in the "tasks.json" file. So for the next run, no question asked.
When I create a task from the preference ( cpp.buildConfigurations ), it is created as a "Detected task", but when calling "Terminal -> Run task", you keep asking which "problem matcher" to use, you don't save the information inside the preference setting, is it supposed to work like this ?

This is only true for the cpp build config. Other detected tasks do not behave the same way and their problemMatcher preference is stored in their respective tasks.json. I'm not sure what we can do differently only for the cppBuildConfigurations. Ideally I would have liked to separate the preference into it's own file and do more custom changes.

Question 2:
From the "Quick menu item" for the detected task, you have the "settings button" at the end of the line, but nothing happen for the detected task when selecting it, is it normal? For a task define in "tasks.json", you open the file "tasks.json" so should we open the preference setting for the detected task ?

I believe this is correct, the detected task is already defined in the settings.json which can support tasks. Correct me if I'm wrong @elaihau. The difference is that other detected tasks do not act the same way, but for the cpp extension, things are different.

[elaihau]

Hi @lmcbout, thank you for the review!

cpp tasks are different from others in nature: unlike the regular detected tasks that we know which root fold they come from, cpp tasks are defined in preference and not bound to any root folders. If you take a closer look at the GIF I attached to the “how to test” session, you would find the “directory” property was set “/home/elaihau/dev”, a folder that is not even part of my workspace.

I understand that it is more consistent to save the user-chosen problem matchers somewhere so users don’t get prompted every time the task is started, but unfortunately I really have no idea where could that information be kept.
Do you have any suggestions?

[lmcbout]

@elaihau I have no suggestion for the moment, but we should keep it in mind.