[Lldb-commits] [lldb] f3472ad - Add specific error messages around gdb RSP handshake failures

[Jason Molenda via lldb-commits]

Author: Jason Molenda
Date: 2021-09-09T17:02:42-07:00
New Revision: f3472ad5c5f88c3425fc54f40d3d5280258d8be5

URL: https://github.com/llvm/llvm-project/commit/f3472ad5c5f88c3425fc54f40d3d5280258d8be5
DIFF: https://github.com/llvm/llvm-project/commit/f3472ad5c5f88c3425fc54f40d3d5280258d8be5.diff

LOG: Add specific error messages around gdb RSP handshake failures

Report timeout exceeded and connection lost error messages
when sending the initial handshake packet in a gdb remote
serial protocol connection, an especially fragile time.

Differential Revision: https://reviews.llvm.org/D108888

Added: 
    

Modified: 
    lldb/source/Plugins/Process/gdb-remote/GDBRemoteCommunicationClient.cpp

Removed: 
    


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diff  --git a/lldb/source/Plugins/Process/gdb-remote/GDBRemoteCommunicationClient.cpp b/lldb/source/Plugins/Process/gdb-remote/GDBRemoteCommunicationClient.cpp
index 6dcc73c3e43d..16a27af700c6 100644
--- a/lldb/source/Plugins/Process/gdb-remote/GDBRemoteCommunicationClient.cpp
+++ b/lldb/source/Plugins/Process/gdb-remote/GDBRemoteCommunicationClient.cpp
@@ -82,6 +82,8 @@ bool GDBRemoteCommunicationClient::HandshakeWithServer(Status *error_ptr) {
 
   // Start the read thread after we send the handshake ack since if we fail to
   // send the handshake ack, there is no reason to continue...
+  std::chrono::steady_clock::time_point start_of_handshake =
+      std::chrono::steady_clock::now();
   if (SendAck()) {
     // Wait for any responses that might have been queued up in the remote
     // GDB server and flush them all
@@ -97,8 +99,24 @@ bool GDBRemoteCommunicationClient::HandshakeWithServer(Status *error_ptr) {
     if (QueryNoAckModeSupported()) {
       return true;
     } else {
-      if (error_ptr)
-        error_ptr->SetErrorString("failed to get reply to handshake packet");
+      std::chrono::steady_clock::time_point end_of_handshake =
+          std::chrono::steady_clock::now();
+      auto handshake_timeout =
+          std::chrono::duration<double>(end_of_handshake - start_of_handshake)
+              .count();
+      if (error_ptr) {
+        if (packet_result == PacketResult::ErrorDisconnected)
+          error_ptr->SetErrorString("Connection shut down by remote side "
+                                    "while waiting for reply to initial "
+                                    "handshake packet");
+        else if (packet_result == PacketResult::ErrorReplyTimeout)
+          error_ptr->SetErrorStringWithFormat(
+              "failed to get reply to handshake packet within timeout of "
+              "%.1f seconds",
+              handshake_timeout);
+        else
+          error_ptr->SetErrorString("failed to get reply to handshake packet");
+      }
     }
   } else {
     if (error_ptr)