[Lldb-commits] [lldb] Initial step in targets DAP support (PR #86623)

[Walter Erquinigo via lldb-commits]

================
@@ -3180,14 +3180,159 @@ void request_stepIn(const llvm::json::Object &request) {
   llvm::json::Object response;
   FillResponse(request, response);
   auto arguments = request.getObject("arguments");
+
+  std::string step_in_target;
+  uint64_t target_id = GetUnsigned(arguments, "targetId", 0);
+  auto it = g_dap.step_in_targets.find(target_id);
+  if (it != g_dap.step_in_targets.end())
+    step_in_target = it->second;
+
+  const bool single_thread = GetBoolean(arguments, "singleThread", false);
+  lldb::RunMode run_mode =
+      single_thread ? lldb::eOnlyThisThread : lldb::eOnlyDuringStepping;
   lldb::SBThread thread = g_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.
     g_dap.focus_tid = thread.GetThreadID();
-    thread.StepInto();
+    thread.StepInto(step_in_target.c_str(), run_mode);
+  } else {
+    response["success"] = llvm::json::Value(false);
+  }
+  g_dap.SendJSON(llvm::json::Value(std::move(response)));
+}
+
+// "StepInTargetsRequest": {
+//   "allOf": [ { "$ref": "#/definitions/Request" }, {
+//     "type": "object",
+//     "description": "This request retrieves the possible step-in targets for
+//     the specified stack frame.\nThese targets can be used in the `stepIn`
+//     request.\nClients should only call this request if the corresponding
+//     capability `supportsStepInTargetsRequest` is true.", "properties": {
+//       "command": {
+//         "type": "string",
+//         "enum": [ "stepInTargets" ]
+//       },
+//       "arguments": {
+//         "$ref": "#/definitions/StepInTargetsArguments"
+//       }
+//     },
+//     "required": [ "command", "arguments"  ]
+//   }]
+// },
+// "StepInTargetsArguments": {
+//   "type": "object",
+//   "description": "Arguments for `stepInTargets` request.",
+//   "properties": {
+//     "frameId": {
+//       "type": "integer",
+//       "description": "The stack frame for which to retrieve the possible
+//       step-in targets."
+//     }
+//   },
+//   "required": [ "frameId" ]
+// },
+// "StepInTargetsResponse": {
+//   "allOf": [ { "$ref": "#/definitions/Response" }, {
+//     "type": "object",
+//     "description": "Response to `stepInTargets` request.",
+//     "properties": {
+//       "body": {
+//         "type": "object",
+//         "properties": {
+//           "targets": {
+//             "type": "array",
+//             "items": {
+//               "$ref": "#/definitions/StepInTarget"
+//             },
+//             "description": "The possible step-in targets of the specified
+//             source location."
+//           }
+//         },
+//         "required": [ "targets" ]
+//       }
+//     },
+//     "required": [ "body" ]
+//   }]
+// }
+void request_stepInTargets(const llvm::json::Object &request) {
+  llvm::json::Object response;
+  FillResponse(request, response);
+  auto arguments = request.getObject("arguments");
+
+  g_dap.step_in_targets.clear();
+  lldb::SBFrame frame = g_dap.GetLLDBFrame(*arguments);
+  if (frame.IsValid()) {
+    lldb::SBAddress pc_addr = frame.GetPCAddress();
+    lldb::addr_t line_end_addr = pc_addr.GetLineEntry()
+                                     .GetSameLineContiguousAddressRangeEnd(
+                                         /*include_inlined_functions=*/true)
+                                     .GetLoadAddress(g_dap.target);
+
+    int max_inst_count = line_end_addr - pc_addr.GetLoadAddress(g_dap.target);
+    lldb::SBInstructionList insts =
+        g_dap.target.ReadInstructions(pc_addr, max_inst_count);
----------------
walter-erquinigo wrote:

Please write a new `ReadInstructions` API that is range based. Internally you can use `Disassembler::DisassembleRange`.
That way you'll decode only the minimum necessary instructions.

https://github.com/llvm/llvm-project/pull/86623