[Lldb-commits] [lldb] [lldb-dap] Refactoring lldb-dap port listening mode to allow multiple connections. (PR #116392)

[John Harrison via lldb-commits]

================
@@ -32,35 +34,44 @@ using namespace lldb_dap;
 
 namespace lldb_dap {
 
-DAP::DAP(llvm::StringRef path, ReplMode repl_mode)
-    : debug_adaptor_path(path), broadcaster("lldb-dap"),
-      exception_breakpoints(), focus_tid(LLDB_INVALID_THREAD_ID),
-      stop_at_entry(false), is_attach(false),
+DAP::DAP(llvm::StringRef path, llvm::raw_ostream *log, ReplMode repl_mode,
+         std::vector<std::string> pre_init_commands)
+    : debug_adaptor_path(path), broadcaster("lldb-dap"), log(log),
+      exception_breakpoints(), pre_init_commands(pre_init_commands),
+      focus_tid(LLDB_INVALID_THREAD_ID), stop_at_entry(false), is_attach(false),
       enable_auto_variable_summaries(false),
       enable_synthetic_child_debugging(false),
       display_extended_backtrace(false),
       restarting_process_id(LLDB_INVALID_PROCESS_ID),
       configuration_done_sent(false), waiting_for_run_in_terminal(false),
       progress_event_reporter(
           [&](const ProgressEvent &event) { SendJSON(event.ToJSON()); }),
-      reverse_request_seq(0), repl_mode(repl_mode) {
-  const char *log_file_path = getenv("LLDBDAP_LOG");
-#if defined(_WIN32)
-  // Windows opens stdout and stdin in text mode which converts \n to 13,10
-  // while the value is just 10 on Darwin/Linux. Setting the file mode to binary
-  // fixes this.
-  int result = _setmode(fileno(stdout), _O_BINARY);
-  assert(result);
-  result = _setmode(fileno(stdin), _O_BINARY);
-  UNUSED_IF_ASSERT_DISABLED(result);
-  assert(result);
-#endif
-  if (log_file_path)
-    log.reset(new std::ofstream(log_file_path));
-}
+      reverse_request_seq(0), repl_mode(repl_mode) {}
 
 DAP::~DAP() = default;
 
+llvm::Error DAP::ConfigureIO(int out_fd, int err_fd) {
+  llvm::Expected<int> new_stdout_fd =
+      RedirectFd(out_fd, [this](llvm::StringRef data) {
+        SendOutput(OutputType::Stdout, data);
+      });
----------------
ashgti wrote:

Adjusted the RedirectFD to clean up once the DAP object is not used anymore. This includes making a best effort to use `dup2` to revert the FD redirects.


As for stderr handling, in server mode it no longer setups a redirect on stderr to the current connection. When I allocate the SBDebugger I also configure the OutputFile and ErrorFile handles to pipes that forward to that specific connection.

This does mean that if we are running in a server mode and some part of lldb (or llvm/clang/etc.) print directly to stderr then it wouldn't be associated with the debug session, but I think that would be an issue for other users of the SBDebugger API. 

I know that Xcode also has a helper `lldb-rpc-server` that is a similar configuration to the lldb-dap server mode. When a debug session starts in Xcode it starts an `lldb-rpc-server` that hosts all the SBDebugger instances. So a single version of Xcode will have 1 instance of `lldb-rpc-server` running at a time and that instance is used to run each debug session for each Xcode window. But my overall point with this is that if there are parts of the stack that are not respecting the SBDebugger's OutputFile and ErrorFile it would also show up in Xcode.



https://github.com/llvm/llvm-project/pull/116392