[lldb/Reproducers] Support multiple GDB remotes

When running the test suite with always capture on, a handful of tests
are failing because they have multiple targets and therefore multiple
GDB remote connections. The current reproducer infrastructure is capable
of dealing with that.

This patch reworks the GDB remote provider to support multiple GDB
remote connections, similar to how the reproducers support shadowing
multiple command interpreter inputs. The provider now keeps a list of
packet recorders which deal with a single GDB remote connection. During
replay we rely on the order of creation to match the number of packets
to the GDB remote connection.

Differential revision: https://reviews.llvm.org/D71105

1 files changed, 17 insertions, 14 deletions

diff --git a/lldb/source/Plugins/Process/gdb-remote/ProcessGDBRemote.cpp b/lldb/source/Plugins/Process/gdb-remote/ProcessGDBRemote.cpp
index dfef06aa6ea..95f3d1fcc53 100644
--- a/lldb/source/Plugins/Process/gdb-remote/ProcessGDBRemote.cpp
+++ b/lldb/source/Plugins/Process/gdb-remote/ProcessGDBRemote.cpp
@@ -279,12 +279,9 @@ ProcessGDBRemote::ProcessGDBRemote(lldb::TargetSP target_sp,
                                    "async thread did exit");
 
   if (repro::Generator *g = repro::Reproducer::Instance().GetGenerator()) {
-    repro::ProcessGDBRemoteProvider &provider =
-        g->GetOrCreate<repro::ProcessGDBRemoteProvider>();
-    // Set the history stream to the stream owned by the provider.
-    m_gdb_comm.SetHistoryStream(provider.GetHistoryStream());
-    // Make sure to clear the stream again when we're finished.
-    provider.SetCallback([&]() { m_gdb_comm.SetHistoryStream(nullptr); });
+    repro::GDBRemoteProvider &provider =
+        g->GetOrCreate<repro::GDBRemoteProvider>();
+    m_gdb_comm.SetPacketRecorder(provider.GetNewPacketRecorder());
   }
 
   Log *log(ProcessGDBRemoteLog::GetLogIfAllCategoriesSet(GDBR_LOG_ASYNC));
@@ -3362,17 +3359,20 @@ Status ProcessGDBRemote::ConnectToReplayServer(repro::Loader *loader) {
   if (!loader)
     return Status("No loader provided.");
 
-  // Construct replay history path.
-  FileSpec history_file =
-      loader->GetFile<repro::ProcessGDBRemoteProvider::Info>();
-  if (!history_file)
-    return Status("No provider for gdb-remote.");
+  static std::unique_ptr<repro::MultiLoader<repro::GDBRemoteProvider>>
+      multi_loader = repro::MultiLoader<repro::GDBRemoteProvider>::Create(
+          repro::Reproducer::Instance().GetLoader());
 
-  // Enable replay mode.
-  m_replay_mode = true;
+  if (!multi_loader)
+    return Status("No gdb remote provider found.");
+
+  llvm::Optional<std::string> history_file = multi_loader->GetNextFile();
+  if (!history_file)
+    return Status("No gdb remote packet log found.");
 
   // Load replay history.
-  if (auto error = m_gdb_replay_server.LoadReplayHistory(history_file))
+  if (auto error =
+          m_gdb_replay_server.LoadReplayHistory(FileSpec(*history_file)))
     return Status("Unable to load replay history");
 
   // Make a local connection.
@@ -3380,6 +3380,9 @@ Status ProcessGDBRemote::ConnectToReplayServer(repro::Loader *loader) {
                                                           m_gdb_replay_server))
     return Status("Unable to connect to replay server");
 
+  // Enable replay mode.
+  m_replay_mode = true;
+
   // Start server thread.
   m_gdb_replay_server.StartAsyncThread();