[lldb] [gdb-remote] Implement the vRun packet

Implement the simpler vRun packet and prefer it over the A packet.
Unlike the latter, it tranmits command-line arguments without redundant
indices and lengths.  This also improves GDB compatibility since modern
versions of gdbserver do not implement the A packet at all.

Make qLaunchSuccess not obligatory when using vRun.  It is not
implemented by gdbserver, and since vRun returns the stop reason,
we can assume it to be successful.

Differential Revision: https://reviews.llvm.org/D107931

1 files changed, 35 insertions, 0 deletions

diff --git a/lldb/source/Plugins/Process/gdb-remote/GDBRemoteCommunicationServerLLGS.cpp b/lldb/source/Plugins/Process/gdb-remote/GDBRemoteCommunicationServerLLGS.cpp
index 3b8ed86..1ad838b 100644
--- a/lldb/source/Plugins/Process/gdb-remote/GDBRemoteCommunicationServerLLGS.cpp
+++ b/lldb/source/Plugins/Process/gdb-remote/GDBRemoteCommunicationServerLLGS.cpp
@@ -183,6 +183,9 @@ void GDBRemoteCommunicationServerLLGS::RegisterPacketHandlers() {
       StringExtractorGDBRemote::eServerPacketType_vCont_actions,
       &GDBRemoteCommunicationServerLLGS::Handle_vCont_actions);
   RegisterMemberFunctionHandler(
+      StringExtractorGDBRemote::eServerPacketType_vRun,
+      &GDBRemoteCommunicationServerLLGS::Handle_vRun);
+  RegisterMemberFunctionHandler(
       StringExtractorGDBRemote::eServerPacketType_x,
       &GDBRemoteCommunicationServerLLGS::Handle_memory_read);
   RegisterMemberFunctionHandler(StringExtractorGDBRemote::eServerPacketType_Z,
@@ -3256,6 +3259,38 @@ GDBRemoteCommunicationServerLLGS::Handle_vAttachOrWait(
 }
 
 GDBRemoteCommunication::PacketResult
+GDBRemoteCommunicationServerLLGS::Handle_vRun(
+    StringExtractorGDBRemote &packet) {
+  Log *log(GetLogIfAnyCategoriesSet(LIBLLDB_LOG_PROCESS));
+
+  llvm::StringRef s = packet.GetStringRef();
+  if (!s.consume_front("vRun;"))
+    return SendErrorResponse(8);
+
+  llvm::SmallVector<llvm::StringRef, 16> argv;
+  s.split(argv, ';');
+
+  for (llvm::StringRef hex_arg : argv) {
+    StringExtractor arg_ext{hex_arg};
+    std::string arg;
+    arg_ext.GetHexByteString(arg);
+    m_process_launch_info.GetArguments().AppendArgument(arg);
+    LLDB_LOGF(log, "LLGSPacketHandler::%s added arg: \"%s\"", __FUNCTION__,
+              arg.c_str());
+  }
+
+  if (!argv.empty()) {
+    m_process_launch_info.GetExecutableFile().SetFile(
+        m_process_launch_info.GetArguments()[0].ref(), FileSpec::Style::native);
+    m_process_launch_error = LaunchProcess();
+    if (m_process_launch_error.Success())
+      return SendStopReasonForState(m_current_process->GetState());
+    LLDB_LOG(log, "failed to launch exe: {0}", m_process_launch_error);
+  }
+  return SendErrorResponse(8);
+}
+
+GDBRemoteCommunication::PacketResult
 GDBRemoteCommunicationServerLLGS::Handle_D(StringExtractorGDBRemote &packet) {
   StopSTDIOForwarding();