Add stacktrace paging support to debug adapter

package.json

@@ -496,6 +496,11 @@
                 ],
                 "description": "Delve Api Version to use. Default value is 2.",
                 "default": 2
+              },
+              "stackTraceDepth": {
+                "type": "number",
+                "description": "Maximum depth of stack trace collected from Delve",
+                "default": 20
               }
             }
           }

src/debugAdapter/goDebug.ts

@@ -210,6 +210,8 @@ interface LaunchRequestArguments extends DebugProtocol.LaunchRequestArguments {
 	dlvLoadConfig?: LoadConfig;
 	/** Delve Version */
 	apiVersion: number;
+	/** Delve maximum stack trace depth */
+	stackTraceDepth: number;
 }
 
 process.on('uncaughtException', (err: any) => {
@@ -258,6 +260,7 @@ class Delve {
 	noDebug: boolean;
 	isApiV1: boolean;
 	dlvEnv: any;
+	stackTraceDepth: number;
 
 	constructor(remotePath: string, port: number, host: string, program: string, launchArgs: LaunchRequestArguments) {
 		this.program = normalizePath(program);
@@ -268,6 +271,7 @@ class Delve {
 		} else if (typeof launchArgs['useApiV1'] === 'boolean') {
 			this.isApiV1 = launchArgs['useApiV1'];
 		}
+		this.stackTraceDepth = launchArgs.stackTraceDepth;
 		let mode = launchArgs.mode;
 		let dlvCwd = dirname(program);
 		let isProgramDirectory = false;
@@ -770,7 +774,8 @@ class GoDebugSession extends DebugSession {
 
 	protected stackTraceRequest(response: DebugProtocol.StackTraceResponse, args: DebugProtocol.StackTraceArguments): void {
 		verbose('StackTraceRequest');
-		let stackTraceIn = { id: args.threadId, depth: args.levels };
+		// delve does not support frame paging, so we ask for a large depth
+		let stackTraceIn = { id: args.threadId, depth: this.delve.stackTraceDepth };
 		if (!this.delve.isApiV1) {
 			Object.assign(stackTraceIn, { full: false, cfg: this.delve.loadConfig });
 		}
@@ -793,7 +798,13 @@ class GoDebugSession extends DebugSession {
 					0
 				)
 			);
-			response.body = { stackFrames };
+			if (args.startFrame > 0) {
+				stackFrames = stackFrames.slice(args.startFrame);
+			}
+			if (args.levels > 0) {
+				stackFrames = stackFrames.slice(0, args.levels);
+			}
+			response.body = { stackFrames, totalFrames: locations.length };
 			this.sendResponse(response);
 			verbose('StackTraceResponse');
 		});