Handle O reply packets during qRcmd
Summary:
Gdb servers like openocd may send many $O reply packets for the client to output during a qRcmd command sequence. Currently, lldb interprets the first O packet as an unexpected response. Besides generating no output, this causes lldb to get out of sync with future commands because it continues reading O packets from the first command as response to subsequent commands.
This patch handles any O packets during an qRcmd, treating the first non-O packet as the true response.
Preliminary discussion at http://lists.llvm.org/pipermail/lldb-dev/2018-January/013078.html
Reviewers: clayborg
Reviewed By: clayborg
Subscribers: labath, lldb-commits
Differential Revision: https://reviews.llvm.org/D41745
Patch by Owen Shaw <llvm@owenpshaw.net>
llvm-svn: 322190
diff --git a/lldb/source/Plugins/Process/gdb-remote/GDBRemoteClientBase.cpp b/lldb/source/Plugins/Process/gdb-remote/GDBRemoteClientBase.cpp
index 4d4a4f8..62b8845 100644
--- a/lldb/source/Plugins/Process/gdb-remote/GDBRemoteClientBase.cpp
+++ b/lldb/source/Plugins/Process/gdb-remote/GDBRemoteClientBase.cpp
@@ -177,6 +177,30 @@
}
GDBRemoteCommunication::PacketResult
+GDBRemoteClientBase::SendPacketAndReceiveResponseWithOutputSupport(
+ llvm::StringRef payload, StringExtractorGDBRemote &response,
+ bool send_async,
+ llvm::function_ref<void(llvm::StringRef)> output_callback) {
+ Lock lock(*this, send_async);
+ if (!lock) {
+ if (Log *log =
+ ProcessGDBRemoteLog::GetLogIfAllCategoriesSet(GDBR_LOG_PROCESS))
+ log->Printf("GDBRemoteClientBase::%s failed to get mutex, not sending "
+ "packet '%.*s' (send_async=%d)",
+ __FUNCTION__, int(payload.size()), payload.data(),
+ send_async);
+ return PacketResult::ErrorSendFailed;
+ }
+
+ PacketResult packet_result = SendPacketNoLock(payload);
+ if (packet_result != PacketResult::Success)
+ return packet_result;
+
+ return ReadPacketWithOutputSupport(response, GetPacketTimeout(), true,
+ output_callback);
+}
+
+GDBRemoteCommunication::PacketResult
GDBRemoteClientBase::SendPacketAndWaitForResponseNoLock(
llvm::StringRef payload, StringExtractorGDBRemote &response) {
PacketResult packet_result = SendPacketNoLock(payload);
diff --git a/lldb/source/Plugins/Process/gdb-remote/GDBRemoteClientBase.h b/lldb/source/Plugins/Process/gdb-remote/GDBRemoteClientBase.h
index 2646405..3d84ce0 100644
--- a/lldb/source/Plugins/Process/gdb-remote/GDBRemoteClientBase.h
+++ b/lldb/source/Plugins/Process/gdb-remote/GDBRemoteClientBase.h
@@ -48,6 +48,11 @@
StringExtractorGDBRemote &response,
bool send_async);
+ PacketResult SendPacketAndReceiveResponseWithOutputSupport(
+ llvm::StringRef payload, StringExtractorGDBRemote &response,
+ bool send_async,
+ llvm::function_ref<void(llvm::StringRef)> output_callback);
+
bool SendvContPacket(llvm::StringRef payload,
StringExtractorGDBRemote &response);
diff --git a/lldb/source/Plugins/Process/gdb-remote/GDBRemoteCommunication.cpp b/lldb/source/Plugins/Process/gdb-remote/GDBRemoteCommunication.cpp
index 18d9631..dd57dd1 100644
--- a/lldb/source/Plugins/Process/gdb-remote/GDBRemoteCommunication.cpp
+++ b/lldb/source/Plugins/Process/gdb-remote/GDBRemoteCommunication.cpp
@@ -275,6 +275,23 @@
}
GDBRemoteCommunication::PacketResult
+GDBRemoteCommunication::ReadPacketWithOutputSupport(
+ StringExtractorGDBRemote &response, Timeout<std::micro> timeout,
+ bool sync_on_timeout,
+ llvm::function_ref<void(llvm::StringRef)> output_callback) {
+ auto result = ReadPacket(response, timeout, sync_on_timeout);
+ while (result == PacketResult::Success && response.IsNormalResponse() &&
+ response.PeekChar() == 'O') {
+ response.GetChar();
+ std::string output;
+ if (response.GetHexByteString(output))
+ output_callback(output);
+ result = ReadPacket(response, timeout, sync_on_timeout);
+ }
+ return result;
+}
+
+GDBRemoteCommunication::PacketResult
GDBRemoteCommunication::ReadPacket(StringExtractorGDBRemote &response,
Timeout<std::micro> timeout,
bool sync_on_timeout) {
diff --git a/lldb/source/Plugins/Process/gdb-remote/GDBRemoteCommunication.h b/lldb/source/Plugins/Process/gdb-remote/GDBRemoteCommunication.h
index ecc9386..ddd2212 100644
--- a/lldb/source/Plugins/Process/gdb-remote/GDBRemoteCommunication.h
+++ b/lldb/source/Plugins/Process/gdb-remote/GDBRemoteCommunication.h
@@ -232,6 +232,11 @@
PacketResult ReadPacket(StringExtractorGDBRemote &response,
Timeout<std::micro> timeout, bool sync_on_timeout);
+ PacketResult ReadPacketWithOutputSupport(
+ StringExtractorGDBRemote &response, Timeout<std::micro> timeout,
+ bool sync_on_timeout,
+ llvm::function_ref<void(llvm::StringRef)> output_callback);
+
// Pop a packet from the queue in a thread safe manner
PacketResult PopPacketFromQueue(StringExtractorGDBRemote &response,
Timeout<std::micro> timeout);
diff --git a/lldb/source/Plugins/Process/gdb-remote/ProcessGDBRemote.cpp b/lldb/source/Plugins/Process/gdb-remote/ProcessGDBRemote.cpp
index 44efcbe..78399b7 100644
--- a/lldb/source/Plugins/Process/gdb-remote/ProcessGDBRemote.cpp
+++ b/lldb/source/Plugins/Process/gdb-remote/ProcessGDBRemote.cpp
@@ -5145,10 +5145,11 @@
bool send_async = true;
StringExtractorGDBRemote response;
- process->GetGDBRemote().SendPacketAndWaitForResponse(
- packet.GetString(), response, send_async);
- result.SetStatus(eReturnStatusSuccessFinishResult);
Stream &output_strm = result.GetOutputStream();
+ process->GetGDBRemote().SendPacketAndReceiveResponseWithOutputSupport(
+ packet.GetString(), response, send_async,
+ [&output_strm](llvm::StringRef output) { output_strm << output; });
+ result.SetStatus(eReturnStatusSuccessFinishResult);
output_strm.Printf(" packet: %s\n", packet.GetData());
const std::string &response_str = response.GetStringRef();