Add lldb-gdbserver support for Linux x86_64.

This change brings in lldb-gdbserver (llgs) specifically for Linux x86_64.
(More architectures coming soon).

Not every debugserver option is covered yet.  Currently
the lldb-gdbserver command line can start unattached,
start attached to a pid (process-name attach not supported yet),
or accept lldb attaching and launching a process or connecting
by process id.

The history of this large change can be found here:
https://github.com/tfiala/lldb/tree/dev-tfiala-native-protocol-linux-x86_64

Until mid/late April, I was not sharing the work and continued
to rebase it off of head (developed via id tfiala@google.com).  I switched over to
user todd.fiala@gmail.com in the middle, and once I went to github, I did
merges rather than rebasing so I could share with others.

llvm-svn: 212069

lldb/source/Host/common/NativeThreadProtocol.cpp

@@ -0,0 +1,97 @@
+//===-- NativeThreadProtocol.cpp --------------------------------*- C++ -*-===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+#include "NativeThreadProtocol.h"
+
+#include "NativeProcessProtocol.h"
+#include "lldb/Target/NativeRegisterContext.h"
+#include "SoftwareBreakpoint.h"
+
+using namespace lldb;
+using namespace lldb_private;
+
+NativeThreadProtocol::NativeThreadProtocol (NativeProcessProtocol *process, lldb::tid_t tid) :
+    m_process_wp (process->shared_from_this ()),
+    m_tid (tid)
+{
+}
+
+Error
+NativeThreadProtocol::ReadRegister (uint32_t reg, RegisterValue &reg_value)
+{
+    NativeRegisterContextSP register_context_sp = GetRegisterContext ();
+    if (!register_context_sp)
+        return Error ("no register context");
+
+    const RegisterInfo *const reg_info = register_context_sp->GetRegisterInfoAtIndex (reg);
+    if (!reg_info)
+        return Error ("no register info for reg num %" PRIu32, reg);
+
+    return register_context_sp->ReadRegister (reg_info, reg_value);;
+}
+
+Error
+NativeThreadProtocol::WriteRegister (uint32_t reg, const RegisterValue &reg_value)
+{
+    NativeRegisterContextSP register_context_sp = GetRegisterContext ();
+    if (!register_context_sp)
+        return Error ("no register context");
+
+    const RegisterInfo *const reg_info = register_context_sp->GetRegisterInfoAtIndex (reg);
+    if (!reg_info)
+        return Error ("no register info for reg num %" PRIu32, reg);
+
+    return register_context_sp->WriteRegister (reg_info, reg_value);
+}
+
+Error
+NativeThreadProtocol::SaveAllRegisters (lldb::DataBufferSP &data_sp)
+{
+    NativeRegisterContextSP register_context_sp = GetRegisterContext ();
+    if (!register_context_sp)
+        return Error ("no register context");
+    return register_context_sp->WriteAllRegisterValues (data_sp);
+}
+
+Error
+NativeThreadProtocol::RestoreAllRegisters (lldb::DataBufferSP &data_sp)
+{
+    NativeRegisterContextSP register_context_sp = GetRegisterContext ();
+    if (!register_context_sp)
+        return Error ("no register context");
+    return register_context_sp->ReadAllRegisterValues (data_sp);
+}
+
+NativeProcessProtocolSP
+NativeThreadProtocol::GetProcess ()
+{
+    return m_process_wp.lock ();
+}
+
+uint32_t
+NativeThreadProtocol::TranslateStopInfoToGdbSignal (const ThreadStopInfo &stop_info) const
+{
+    // Default: no translation.  Do the real translation where there
+    // is access to the host signal numbers.
+    switch (stop_info.reason)
+    {
+        case eStopReasonSignal:
+            return stop_info.details.signal.signo;
+            break;
+
+        case eStopReasonException:
+            // FIXME verify the way to specify pass-thru here.
+            return static_cast<uint32_t> (stop_info.details.exception.type);
+            break;
+
+        default:
+            assert (0 && "unexpected stop_info.reason found");
+            return 0;
+    }
+}