[lldb-dap] Migrating the 'stepOut' request to use typed RequestHandler. (#137362)

This moves the 'stepOut' request to the typed RequestHandler.

Author: ashgti

lldb/tools/lldb-dap/Handler/RequestHandler.h

@@ -331,11 +331,12 @@ class StepInTargetsRequestHandler : public LegacyRequestHandler {
   void operator()(const llvm::json::Object &request) const override;
 };
 
-class StepOutRequestHandler : public LegacyRequestHandler {
+class StepOutRequestHandler : public RequestHandler<protocol::StepOutArguments,
+                                                    protocol::StepOutResponse> {
 public:
-  using LegacyRequestHandler::LegacyRequestHandler;
+  using RequestHandler::RequestHandler;
   static llvm::StringLiteral GetCommand() { return "stepOut"; }
-  void operator()(const llvm::json::Object &request) const override;
+  llvm::Error Run(const protocol::StepOutArguments &args) const override;
 };
 
 class SetBreakpointsRequestHandler : public LegacyRequestHandler {

lldb/tools/lldb-dap/Handler/StepOutRequestHandler.cpp

@@ -8,62 +8,36 @@
 
 #include "DAP.h"
 #include "EventHelper.h"
-#include "JSONUtils.h"
+#include "Protocol/ProtocolRequests.h"
 #include "RequestHandler.h"
+#include "llvm/Support/Error.h"
+
+using namespace llvm;
+using namespace lldb_dap::protocol;
 
 namespace lldb_dap {
 
-// "StepOutRequest": {
-//   "allOf": [ { "$ref": "#/definitions/Request" }, {
-//     "type": "object",
-//     "description": "StepOut request; value of command field is 'stepOut'. The
-//     request starts the debuggee to run again for one step. The debug adapter
-//     first sends the StepOutResponse and then a StoppedEvent (event type
-//     'step') after the step has completed.", "properties": {
-//       "command": {
-//         "type": "string",
-//         "enum": [ "stepOut" ]
-//       },
-//       "arguments": {
-//         "$ref": "#/definitions/StepOutArguments"
-//       }
-//     },
-//     "required": [ "command", "arguments"  ]
-//   }]
-// },
-// "StepOutArguments": {
-//   "type": "object",
-//   "description": "Arguments for 'stepOut' request.",
-//   "properties": {
-//     "threadId": {
-//       "type": "integer",
-//       "description": "Execute 'stepOut' for this thread."
-//     }
-//   },
-//   "required": [ "threadId" ]
-// },
-// "StepOutResponse": {
-//   "allOf": [ { "$ref": "#/definitions/Response" }, {
-//     "type": "object",
-//     "description": "Response to 'stepOut' request. This is just an
-//     acknowledgement, so no body field is required."
-//   }]
-// }
-void StepOutRequestHandler::operator()(
-    const llvm::json::Object &request) const {
-  llvm::json::Object response;
-  FillResponse(request, response);
-  const auto *arguments = request.getObject("arguments");
-  lldb::SBThread thread = dap.GetLLDBThread(*arguments);
-  if (thread.IsValid()) {
-    // Remember the thread ID that caused the resume so we can set the
-    // "threadCausedFocus" boolean value in the "stopped" events.
-    dap.focus_tid = thread.GetThreadID();
-    thread.StepOut();
-  } else {
-    response["success"] = llvm::json::Value(false);
-  }
-  dap.SendJSON(llvm::json::Value(std::move(response)));
+/// The request resumes the given thread to step out (return) from a
+/// function/method and allows all other threads to run freely by resuming
+/// them.
+///
+/// If the debug adapter supports single thread execution (see capability
+/// `supportsSingleThreadExecutionRequests`), setting the `singleThread`
+/// argument to true prevents other suspended threads from resuming.
+///
+/// The debug adapter first sends the response and then a `stopped` event (with
+/// reason `step`) after the step has completed."
+Error StepOutRequestHandler::Run(const StepOutArguments &arguments) const {
+  lldb::SBThread thread = dap.GetLLDBThread(arguments.threadId);
+  if (!thread.IsValid())
+    return make_error<DAPError>("invalid thread");
+
+  // Remember the thread ID that caused the resume so we can set the
+  // "threadCausedFocus" boolean value in the "stopped" events.
+  dap.focus_tid = thread.GetThreadID();
+  thread.StepOut();
+
+  return Error::success();
 }
 
 } // namespace lldb_dap

lldb/tools/lldb-dap/Protocol/ProtocolRequests.cpp

@@ -293,4 +293,12 @@ bool fromJSON(const llvm::json::Value &Params, StepInArguments &SIA,
          OM.mapOptional("granularity", SIA.granularity);
 }
 
+bool fromJSON(const llvm::json::Value &Params, StepOutArguments &SOA,
+              llvm::json::Path P) {
+  json::ObjectMapper OM(Params, P);
+  return OM && OM.map("threadId", SOA.threadId) &&
+         OM.mapOptional("singleThread", SOA.singleThread) &&
+         OM.mapOptional("granularity", SOA.granularity);
+}
+
 } // namespace lldb_dap::protocol

lldb/tools/lldb-dap/Protocol/ProtocolRequests.h

@@ -358,6 +358,25 @@ bool fromJSON(const llvm::json::Value &, StepInArguments &, llvm::json::Path);
 /// body field is required.
 using StepInResponse = VoidResponse;
 
+/// Arguments for `stepOut` request.
+struct StepOutArguments {
+  /// Specifies the thread for which to resume execution for one step-out (of
+  /// the given granularity).
+  uint64_t threadId = LLDB_INVALID_THREAD_ID;
+
+  /// If this flag is true, all other suspended threads are not resumed.
+  std::optional<bool> singleThread;
+
+  /// Stepping granularity. If no granularity is specified, a granularity of
+  /// `statement` is assumed.
+  SteppingGranularity granularity = eSteppingGranularityStatement;
+};
+bool fromJSON(const llvm::json::Value &, StepOutArguments &, llvm::json::Path);
+
+/// Response to `stepOut` request. This is just an acknowledgement, so no
+/// body field is required.
+using StepOutResponse = VoidResponse;
+
 } // namespace lldb_dap::protocol
 
 #endif