Proposal to add debugConsoleMode to StartDebuggingRequestArguments #575
Description
In #574 I have added a proposal for the field "debugConsoleMode" inside StartDebuggingRequestArguments. This specifies if a new debug console window should be created or the output should be merged with the parent session's console.
In VSCode, there is already support for merging the console output with the parent debugging session. Only this functionality is not exposed via the DAP. microsoft/vscode#80673
The particular use case I am chasing is being able to start debug sessions for inferior/subprocesses for a gdb instance. In my DAP implementation I can open a new port for each newly spawned subprocess. Subsequently using StartDebuggingRequest I can make VSCode attach to it and the UI will nicely show that parent+child processes are being debugged.
Gdb is capable of attaching to the new subprocess without starting a new gdb instance, however, the default behavior for VSCode is to open a new debug console which is left unused since no new debugger has been started.
Being able to set debugConsoleMode to "mergeWithParent", it becomes possible to combine the consoles, such that only one console per gdb instance is shown in VSCode. Solving the issue of having unused consoles in the UI.
Future work could include improvements to the ability to disambiguate commands for specific inferior subprocesses. I think it would be nice to lift the requirement of opening a port for each subprocess in my implementation, for instance, by specifying an optional debug session ID in each RPC message.