[Lldb-commits] [lldb] [lldb-dap] Updating RequestHandler to encode/decode arguments and response. (PR #130090)

[John Harrison via lldb-commits]

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@@ -57,235 +68,288 @@ class RequestHandler {
   DAP &dap;
 };
 
-class AttachRequestHandler : public RequestHandler {
-public:
-  using RequestHandler::RequestHandler;
+/// Base class for handling DAP requests. Handlers should declare their
+/// arguments and response body types like:
+///
+/// class MyRequestHandler : public RequestHandler<Arguments, ResponseBody> {
+///   ....
+/// };
+template <typename Args, typename Body>
+class RequestHandler : public BaseRequestHandler {
+  using BaseRequestHandler::BaseRequestHandler;
+
+  void operator()(const llvm::json::Object &request) const override {
+    /* no-op, the other overload handles json coding. */
+  }
+
+  void operator()(const protocol::Request &request) const override {
+    protocol::Response response;
+    response.request_seq = request.seq;
+    response.command = request.command;
+    Args arguments;
+    llvm::json::Path::Root root;
+    if (request.rawArguments &&
+        !fromJSON(request.rawArguments, arguments, root)) {
+      std::string parseFailure;
+      llvm::raw_string_ostream OS(parseFailure);
+      root.printErrorContext(request.rawArguments, OS);
+      response.success = false;
+      response.message = parseFailure;
----------------
ashgti wrote:

I have a FIXME for addressing this, but to minimize the changes I kept this mostly backwards compatible with the current approach.

I can follow up this PR with a `DAPError` type for enhanced error reporting.

https://github.com/llvm/llvm-project/pull/130090