Added an option to "process detach" to keep the process stopped, if the process plugin (or in the
case of ProcessGDBRemote the stub we are talking to) know how to do that.

rdar://problem/13680832


git-svn-id: https://llvm.org/svn/llvm-project/lldb/trunk@180831 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/source/Plugins/Process/gdb-remote/GDBRemoteCommunicationClient.cpp b/source/Plugins/Process/gdb-remote/GDBRemoteCommunicationClient.cpp
index 9351b93..6657c2c 100644
--- a/source/Plugins/Process/gdb-remote/GDBRemoteCommunicationClient.cpp
+++ b/source/Plugins/Process/gdb-remote/GDBRemoteCommunicationClient.cpp
@@ -52,6 +52,7 @@
     m_supports_alloc_dealloc_memory (eLazyBoolCalculate),
     m_supports_memory_region_info  (eLazyBoolCalculate),
     m_supports_watchpoint_support_info  (eLazyBoolCalculate),
+    m_supports_detach_stay_stopped (eLazyBoolCalculate),
     m_watchpoints_trigger_after_instruction(eLazyBoolCalculate),
     m_attach_or_wait_reply(eLazyBoolCalculate),
     m_prepare_for_reg_writing_reply (eLazyBoolCalculate),
@@ -1396,10 +1397,48 @@
     return false;
 }
 
-bool
-GDBRemoteCommunicationClient::Detach ()
+Error
+GDBRemoteCommunicationClient::Detach (bool keep_stopped)
 {
-    return SendPacket ("D", 1) > 0;
+    Error error;
+    
+    if (keep_stopped)
+    {
+        if (m_supports_detach_stay_stopped == eLazyBoolCalculate)
+        {
+            char packet[64];
+            const int packet_len = ::snprintf(packet, sizeof(packet), "qSupportsDetachAndStayStopped:");
+            assert (packet_len < sizeof(packet));
+            StringExtractorGDBRemote response;
+            if (SendPacketAndWaitForResponse (packet, packet_len, response, false))
+            {
+                m_supports_detach_stay_stopped = eLazyBoolYes;        
+            }
+            else
+            {
+                m_supports_detach_stay_stopped = eLazyBoolNo;
+            }
+        }
+
+        if (m_supports_detach_stay_stopped == eLazyBoolNo)
+        {
+            error.SetErrorString("Stays stopped not supported by this target.");
+            return error;
+        }
+        else
+        {
+            size_t num_sent = SendPacket ("D1", 2);
+            if (num_sent == 0)
+                error.SetErrorString ("Sending extended disconnect packet failed.");
+        }
+    }
+    else
+    {
+        size_t num_sent = SendPacket ("D", 1);
+        if (num_sent == 0)
+            error.SetErrorString ("Sending disconnect packet failed.");
+    }
+    return error;
 }
 
 Error