create-checkpoints should handle "latest-trace"

Create checkpoints command need the actual trace dir resolved, so we let `TraceReader` handle that for us.

Author: theIDinside

src/CreateCheckpointsCommand.cc

@@ -96,6 +96,10 @@ int CreateCheckpointsCommand::run(std::vector<std::string>& args) {
     return 1;
   }
 
+  if (trace_dir.empty()) {
+    trace_dir = real_path(resolve_trace_name(""));
+  }
+
   auto verified_frames_to_checkpoint_at =
       CreateCheckpointsCommand::find_events_to_checkpoint(trace_dir, flags);
   if (verified_frames_to_checkpoint_at.empty()) {
@@ -108,6 +112,7 @@ int CreateCheckpointsCommand::run(std::vector<std::string>& args) {
 static bool create_persistent_checkpoint_dir(const string& trace_dir,
                                              FrameTime time) {
   string checkpoint_dir = trace_dir + "/checkpoint-" + std::to_string(time);
+  LOG(debug) << "create checkpoint dir " << checkpoint_dir;
   if (mkdir(checkpoint_dir.c_str(), 0755) == 0) {
     return true;
   }
@@ -119,6 +124,7 @@ int CreateCheckpointsCommand::run_main(
     const std::vector<FrameTime>& verified_events) {
   DEBUG_ASSERT(!verified_events.empty() &&
                "No events provided to checkpoint at.");
+  LOG(debug) << "creating " << verified_events.size() << " persistent checkpoints";
   ReplaySession::Flags session_flags{};
   ReplayTimeline timeline{ ReplaySession::create(trace_dir, session_flags) };
   auto& reader = timeline.current_session().trace_reader();
@@ -141,7 +147,8 @@ int CreateCheckpointsCommand::run_main(
       timeline.remove_explicit_checkpoint(mark);
       LOG(debug) << "Serialized checkpoint at event " << evt;
     } else {
-      FATAL() << "Stopped at wrong event";
+      FATAL() << "Stopped at wrong event: expected=" << evt
+              << " stopped at=" << session.trace_reader().time();
     }
   }
 
@@ -153,6 +160,7 @@ int CreateCheckpointsCommand::run_main(
 std::vector<FrameTime> CreateCheckpointsCommand::find_events_to_checkpoint(
     const std::string& trace_dir, const CreateCheckpointsFlags& flags) {
   TraceReader reader{ trace_dir };
+  LOG(debug) << "find events to checkpoint in " << trace_dir;
   std::vector<FrameTime> events;
   auto total = 0ul;