Stop supporting onDebug:type activation event

[isidorn]

Stop support for onDebug:type

Currently the C++ extension seems to be the only extension getting activated by onDebug:type event. Since we added this event we have introduced alternative ways for extensions to be activated so there is possibly a better way to achieve what the C++ extension needs here.

@pieandcakes could you please clarify how you useonDebug:type in your extension. So we could potentially adivse to use a different solution

fyi @weinand

related #33258

[isidorn]

@pieandcakes ping regarding this issue

[roblourens]

@ramya-rao-a and I noticed that the current state is actually not that great for the Go extension. It contributes a debugger and a language server, so activating is a heavy operation that ideally would only happen when Go files are detected. But now it happens when a debug session of any type is started.

Most debug extensions probably just contribute debuggers, so vscode-go may be an oddball. Any thoughts on how to mitigate this?

microsoft/vscode-go#1324

[testforstephen]

@isidorn @weinand @aeschli
Got similar perf issue for java debugger. When user is debugging non-java project, also activate java language server and debugger extension.
See the issue microsoft/vscode-java-debug#142

[weinand]

@aeschli fyi

[isidorn]

I understand the issue. Thanks for letting us know @roblourens @testforstephen
I do not see this as a critical issue, so I suggest to try to fix this in November. Options:

• introduce new activation event "onDebugSession:type" which would fire everytime a session of that type is about to start. Basically would behave like the old event

Suggestions are also welcome. Once we come to the conclusion I can open a new issue for November to track this.

[weinand]

I've created #37918 to track this.

[weinand]

@isidorn activating on a specific type only would miss the case of collecting all registered DebugConfigurationProviders for the "initialLaunchConfigs" functionality.