<rdar://problem/15172417>

Added two new GDB server packets to debugserver: "QSaveRegisterState" and "QRestoreRegiterState".

"QSaveRegisterState" makes the remote GDB server save all register values and it returns a save identifier as an unsigned integer. This packet can be used prior to running expressions to save all registers.

All registers can them we later restored with "QRestoreRegiterState:SAVEID" what SAVEID is the integer identifier that was returned from the call to QSaveRegisterState.

Cleaned up redundant code in lldb_private::Thread, lldb_private::ThreadPlanCallFunction.
Moved the lldb_private::Thread::RegisterCheckpoint into its own header file and it is now in the lldb_private namespace. Trimmed down the RegisterCheckpoint class to omit stuff that wasn't used (the stack ID).

Added a few new virtual methods to lldb_private::RegisterContext that allow subclasses to efficiently save/restore register states and changed the RegisterContextGDBRemote to take advantage of these new calls.

llvm-svn: 194621

1 files changed, 19 insertions, 0 deletions

diff --git a/lldb/tools/debugserver/source/MacOSX/MachThreadList.cpp b/lldb/tools/debugserver/source/MacOSX/MachThreadList.cpp
index b5ce58d3438..adad95f2f7c 100644
--- a/lldb/tools/debugserver/source/MacOSX/MachThreadList.cpp
+++ b/lldb/tools/debugserver/source/MacOSX/MachThreadList.cpp
@@ -200,6 +200,25 @@ MachThreadList::SetRegisterContext (nub_thread_t tid, const void *buf, size_t bu
     return 0;
 }
 
+uint32_t
+MachThreadList::SaveRegisterState (nub_thread_t tid)
+{
+    MachThreadSP thread_sp (GetThreadByID (tid));
+    if (thread_sp)
+        return thread_sp->SaveRegisterState ();
+    return 0;
+}
+
+bool
+MachThreadList::RestoreRegisterState (nub_thread_t tid, uint32_t save_id)
+{
+    MachThreadSP thread_sp (GetThreadByID (tid));
+    if (thread_sp)
+        return thread_sp->RestoreRegisterState (save_id);
+    return 0;
+}
+
+
 nub_size_t
 MachThreadList::NumThreads () const
 {