1 files changed, 33 insertions, 14 deletions

diff --git a/lldb/source/Plugins/Process/gdb-remote/ThreadGDBRemote.cpp b/lldb/source/Plugins/Process/gdb-remote/ThreadGDBRemote.cpp
index 091feb9e649..b8108bfd383 100644
--- a/lldb/source/Plugins/Process/gdb-remote/ThreadGDBRemote.cpp
+++ b/lldb/source/Plugins/Process/gdb-remote/ThreadGDBRemote.cpp
@@ -37,7 +37,8 @@ ThreadGDBRemote::ThreadGDBRemote (ProcessGDBRemote &process, lldb::tid_t tid) :
     Thread(process, tid),
     m_thread_name (),
     m_dispatch_queue_name (),
-    m_thread_dispatch_qaddr (LLDB_INVALID_ADDRESS)
+    m_thread_dispatch_qaddr (LLDB_INVALID_ADDRESS),
+    m_thread_stop_reason_stop_id (0)
 {
 //    ProcessGDBRemoteLog::LogIf(GDBR_LOG_THREAD | GDBR_LOG_VERBOSE, "ThreadGDBRemote::ThreadGDBRemote ( pid = %i, tid = 0x%4.4x, )", m_process.GetID(), GetID());
     ProcessGDBRemoteLog::LogIf(GDBR_LOG_THREAD, "%p: ThreadGDBRemote::ThreadGDBRemote (pid = %i, tid = 0x%4.4x)", this, m_process.GetID(), GetID());
@@ -116,14 +117,18 @@ ThreadGDBRemote::WillResume (StateType resume_state)
 void
 ThreadGDBRemote::RefreshStateAfterStop()
 {
-    // Invalidate all registers in our register context
-    GetRegisterContext()->Invalidate();
+    // Invalidate all registers in our register context. We don't set "force" to
+    // true because the stop reply packet might have had some register values
+    // that were expedited and these will already be copied into the register
+    // context by the time this function gets called. The GDBRemoteRegisterContext
+    // class has been made smart enough to detect when it needs to invalidate
+    // which registers are valid by putting hooks in the register read and 
+    // register supply functions where they check the process stop ID and do
+    // the right thing.
+    const bool force = false;
+    GetRegisterContext()->InvalidateIfNeeded (force);
 }
 
-// Whether to use the new native unwinder (UnwindLLDB) or the libunwind-remote based unwinder for
-// stack walks on i386/x86_64
-#define USE_NATIVE_UNWINDER
-
 Unwind *
 ThreadGDBRemote::GetUnwinder ()
 {
@@ -132,11 +137,7 @@ ThreadGDBRemote::GetUnwinder ()
         const ArchSpec target_arch (GetProcess().GetTarget().GetArchitecture ());
         if (target_arch == ArchSpec("x86_64") ||  target_arch == ArchSpec("i386"))
         {
-#if defined (USE_NATIVE_UNWINDER)
             m_unwinder_ap.reset (new UnwindLLDB (*this));
-#else
-            m_unwinder_ap.reset (new UnwindLibUnwind (*this, GetGDBProcess().GetLibUnwindAddressSpace()));
-#endif
         }
         else
         {
@@ -198,6 +199,14 @@ ThreadGDBRemote::CreateRegisterContextForFrame (StackFrame *frame)
     return reg_ctx_sp;
 }
 
+void
+ThreadGDBRemote::PrivateSetRegisterValue (uint32_t reg, StringExtractor &response)
+{
+    GDBRemoteRegisterContext *gdb_reg_ctx = static_cast<GDBRemoteRegisterContext *>(GetRegisterContext ().get());
+    assert (gdb_reg_ctx);
+    gdb_reg_ctx->PrivateSetRegisterValue (reg, response);
+}
+
 bool
 ThreadGDBRemote::SaveFrameZeroState (RegisterCheckpoint &checkpoint)
 {
@@ -217,7 +226,7 @@ ThreadGDBRemote::RestoreSaveFrameZero (const RegisterCheckpoint &checkpoint)
     if (frame_sp)
     {
         bool ret = frame_sp->GetRegisterContext()->WriteAllRegisterValues (checkpoint.GetData());
-        frame_sp->GetRegisterContext()->Invalidate();
+        frame_sp->GetRegisterContext()->InvalidateIfNeeded(true);
         ClearStackFrames();
         return ret;
     }
@@ -227,8 +236,19 @@ ThreadGDBRemote::RestoreSaveFrameZero (const RegisterCheckpoint &checkpoint)
 lldb::StopInfoSP
 ThreadGDBRemote::GetPrivateStopReason ()
 {
-    if (m_actual_stop_info_sp.get() == NULL || m_actual_stop_info_sp->IsValid() == false)
+    const uint32_t process_stop_id = GetProcess().GetStopID();
+    if (m_thread_stop_reason_stop_id != process_stop_id ||
+        (m_actual_stop_info_sp && !m_actual_stop_info_sp->IsValid()))
     {
+        // If GetGDBProcess().SetThreadStopInfo() doesn't find a stop reason
+        // for this thread, then m_actual_stop_info_sp will not ever contain
+        // a valid stop reason and the "m_actual_stop_info_sp->IsValid() == false"
+        // check will never be able to tell us if we have the correct stop info
+        // for this thread and we will continually send qThreadStopInfo packets
+        // down to the remote GDB server, so we need to keep our own notion
+        // of the stop ID that m_actual_stop_info_sp is valid for (even if it
+        // contains nothing). We use m_thread_stop_reason_stop_id for this below.
+        m_thread_stop_reason_stop_id = process_stop_id;
         m_actual_stop_info_sp.reset();
 
         char packet[256];
@@ -236,7 +256,6 @@ ThreadGDBRemote::GetPrivateStopReason ()
         StringExtractorGDBRemote stop_packet;
         if (GetGDBProcess().GetGDBRemote().SendPacketAndWaitForResponse(packet, stop_packet, 1, false))
         {
-            std::string copy(stop_packet.GetStringRef());
             GetGDBProcess().SetThreadStopInfo (stop_packet);
         }
     }