vscode.debug API should provide the current thread/stack frame ids

Currently the vscode.debug API provides a way to send custom events to debug adapters. But it is missing one fairly important thing - there is no way to know what the current thread id / frame id is. So a debug adapter could maybe guess. But it feels like there should really be a way to query this.

[PaDebug]

@elazarcoh What do I need to do to write the API proposal?

I would propose extending the debug namespace by an event which fires when the user selected a different stack frame in the call stack window. For example:

export namespace debug {

/**
 * An event which fires when the user selected a different stack frame in the call stack window.
 */
export const onDidChangeSelectedStackFrame: Event<StackFrame>;

}

The interface StackFrame consists of two properties: frameId and associated threadId. This would provide enough information to update the thread and stack frame in the Debug Adapter via custom request.

export interface StackFrame {

/**
 * Id of the associated thread (DAP id).
 */
readonly threadId: number;

/**
 * Id of the stack frame (DAP id).
 */
readonly frameId: number;

}

What do you think about this?

[weinand]

@elazarcoh you can start just here. Please study some existing API items with the “api-proposal” label to learn how API proposals look like.