Qt: Implement GDB server

src/duckstation-qt/gdbconnection.cpp

@@ -0,0 +1,82 @@
+#include "gdbconnection.h"
+#include "qthostinterface.h"
+#include "common/log.h"
+#include "core/gdb_protocol.h"
+Log_SetChannel(GDBConnection);
+
+GDBConnection::GDBConnection(QObject *parent, int descriptor)
+  : QThread(parent), m_descriptor(descriptor)
+{
+  Log_InfoPrintf("(%u) Accepted new connection on GDB server", m_descriptor);
+
+  connect(&m_socket, &QTcpSocket::readyRead, this, &GDBConnection::receivedData);
+  connect(&m_socket, &QTcpSocket::disconnected, this, &GDBConnection::gotDisconnected);
+
+  if (m_socket.setSocketDescriptor(m_descriptor)) {
+    QtHostInterface::GetInstance()->pauseSystem(true, true);
+  }
+  else {
+    Log_ErrorPrintf("(%u) Failed to set socket descriptor: %s", m_descriptor, m_socket.errorString().toUtf8().constData());
+  }
+}
+
+void GDBConnection::gotDisconnected()
+{
+  Log_InfoPrintf("(%u) Client disconnected", m_descriptor);
+  this->exit(0);
+}
+
+void GDBConnection::receivedData()
+{
+  qint64 bytesRead;
+  char buffer[256];
+
+  while ((bytesRead = m_socket.read(buffer, sizeof(buffer))) > 0) {
+    for (char c : std::string_view(buffer, bytesRead)) {
+      m_readBuffer.push_back(c);
+
+      if (GDBProtocol::IsPacketInterrupt(m_readBuffer)) {
+        Log_DebugPrintf("(%u) > Interrupt request", m_descriptor);
+        QtHostInterface::GetInstance()->pauseSystem(true, true);
+        m_readBuffer.erase();
+      }
+      else if (GDBProtocol::IsPacketContinue(m_readBuffer)) {
+        Log_DebugPrintf("(%u) > Continue request", m_descriptor);
+        QtHostInterface::GetInstance()->pauseSystem(false, false);
+        m_readBuffer.erase();
+      }
+      else if (GDBProtocol::IsPacketComplete(m_readBuffer)) {
+        Log_DebugPrintf("(%u) > %s", m_descriptor, m_readBuffer.c_str());
+        writePacket(GDBProtocol::ProcessPacket(m_readBuffer));
+        m_readBuffer.erase();
+      }
+    }
+  }
+  if (bytesRead == -1) {
+    Log_ErrorPrintf("(%u) Failed to read from socket: %s", m_descriptor, m_socket.errorString().toUtf8().constData());
+  }
+}
+
+void GDBConnection::onEmulationPaused(bool paused)
+{
+  if (paused) {
+    if (m_seen_resume) {
+      m_seen_resume = false;
+      // Generate a stop reply packet, insert '?' command to generate it.
+      writePacket(GDBProtocol::ProcessPacket("$?#3f"));
+    }
+  }
+  else {
+    m_seen_resume = true;
+    // Send ack, in case GDB sent a continue request.
+    writePacket("+");
+  }
+}
+
+void GDBConnection::writePacket(std::string_view packet)
+{
+  Log_DebugPrintf("(%u) < %*s", m_descriptor, packet.length(), packet.data());
+  if (m_socket.write(packet.data(), packet.length()) == -1) {
+    Log_ErrorPrintf("(%u) Failed to write to socket: %s", m_descriptor, m_socket.errorString().toUtf8().constData());
+  }
+}