Properly handle when commands are not unsupported in the GDB remote clients.

Prior to this fix we would often call SendPacketAndWaitForResponse() which
returns the number of bytes in the response. The UNSUPPORTED response in the
GDB remote protocol is zero bytes and we were checking for it inside an if
statement:

if (SendPacketAndWaitForResponse(...))
{
    if (response.IsUnsupportedResponse())
    {
        // UNSUPPORTED...
        // This will never happen...
    }
}

We now handle is properly as:

if (SendPacketAndWaitForResponse(...))
{
}
else
{
    // UNSUPPORTED...
}

llvm-svn: 131393

1 files changed, 49 insertions, 55 deletions

diff --git a/lldb/source/Plugins/Process/gdb-remote/GDBRemoteCommunicationClient.cpp b/lldb/source/Plugins/Process/gdb-remote/GDBRemoteCommunicationClient.cpp
index fdd3fe2591b..f4e67022fc6 100644
--- a/lldb/source/Plugins/Process/gdb-remote/GDBRemoteCommunicationClient.cpp
+++ b/lldb/source/Plugins/Process/gdb-remote/GDBRemoteCommunicationClient.cpp
@@ -810,11 +810,7 @@ GDBRemoteCommunicationClient::GetHostInfo (bool force)
         StringExtractorGDBRemote response;
         if (SendPacketAndWaitForResponse ("qHostInfo", response, false))
         {
-            if (response.IsUnsupportedResponse())
-            {
-                return false;
-            }
-            else if (response.IsNormalResponse())
+            if (response.IsNormalResponse())
             {
                 std::string name;
                 std::string value;
@@ -1031,11 +1027,13 @@ GDBRemoteCommunicationClient::AllocateMemory (size_t size, uint32_t permissions)
         StringExtractorGDBRemote response;
         if (SendPacketAndWaitForResponse (packet, packet_len, response, false))
         {
-            if (response.IsUnsupportedResponse())
-                m_supports_alloc_dealloc_memory = eLazyBoolNo;
-            else if (!response.IsErrorResponse())
+            if (!response.IsErrorResponse())
                 return response.GetHexMaxU64(false, LLDB_INVALID_ADDRESS);
         }
+        else
+        {
+            m_supports_alloc_dealloc_memory = eLazyBoolNo;
+        }
     }
     return LLDB_INVALID_ADDRESS;
 }
@@ -1054,8 +1052,10 @@ GDBRemoteCommunicationClient::DeallocateMemory (addr_t addr)
         {
             if (response.IsOKResponse())
                 return true;
-            else if (response.IsUnsupportedResponse())
-                m_supports_alloc_dealloc_memory = eLazyBoolNo;
+        }
+        else
+        {
+            m_supports_alloc_dealloc_memory = eLazyBoolNo;
         }
     }
     return false;
@@ -1241,14 +1241,13 @@ GDBRemoteCommunicationClient::GetProcessInfo (lldb::pid_t pid, ProcessInstanceIn
         StringExtractorGDBRemote response;
         if (SendPacketAndWaitForResponse (packet, packet_len, response, false))
         {
-            if (response.IsUnsupportedResponse())
-            {
-                m_supports_qProcessInfoPID = false;
-                return false;
-            }
-
             return DecodeProcessInfoResponse (response, process_info);
         }
+        else
+        {
+            m_supports_qProcessInfoPID = false;
+            return false;
+        }
     }
     return false;
 }
@@ -1332,12 +1331,6 @@ GDBRemoteCommunicationClient::FindProcesses (const ProcessInstanceInfoMatch &mat
         StringExtractorGDBRemote response;
         if (SendPacketAndWaitForResponse (packet.GetData(), packet.GetSize(), response, false))
         {
-            if (response.IsUnsupportedResponse())
-            {
-                m_supports_qfProcessInfo = false;
-                return 0;
-            }
-
             do
             {
                 ProcessInstanceInfo process_info;
@@ -1348,6 +1341,11 @@ GDBRemoteCommunicationClient::FindProcesses (const ProcessInstanceInfoMatch &mat
                 response.SetFilePos(0);
             } while (SendPacketAndWaitForResponse ("qsProcessInfo", strlen ("qsProcessInfo"), response, false));
         }
+        else
+        {
+            m_supports_qfProcessInfo = false;
+            return 0;
+        }
     }
     return process_infos.GetSize();
     
@@ -1364,12 +1362,6 @@ GDBRemoteCommunicationClient::GetUserName (uint32_t uid, std::string &name)
         StringExtractorGDBRemote response;
         if (SendPacketAndWaitForResponse (packet, packet_len, response, false))
         {
-            if (response.IsUnsupportedResponse())
-            {
-                m_supports_qUserName = false;
-                return false;
-            }
-                
             if (response.IsNormalResponse())
             {
                 // Make sure we parsed the right number of characters. The response is
@@ -1379,6 +1371,11 @@ GDBRemoteCommunicationClient::GetUserName (uint32_t uid, std::string &name)
                     return true;
             }
         }
+        else
+        {
+            m_supports_qUserName = false;
+            return false;
+        }        
     }
     return false;
 
@@ -1395,12 +1392,6 @@ GDBRemoteCommunicationClient::GetGroupName (uint32_t gid, std::string &name)
         StringExtractorGDBRemote response;
         if (SendPacketAndWaitForResponse (packet, packet_len, response, false))
         {
-            if (response.IsUnsupportedResponse())
-            {
-                m_supports_qGroupName = false;
-                return false;
-            }
-            
             if (response.IsNormalResponse())
             {
                 // Make sure we parsed the right number of characters. The response is
@@ -1410,6 +1401,11 @@ GDBRemoteCommunicationClient::GetGroupName (uint32_t gid, std::string &name)
                     return true;
             }
         }
+        else
+        {
+            m_supports_qGroupName = false;
+            return false;
+        }
     }
     return false;
 }
@@ -1488,12 +1484,7 @@ GDBRemoteCommunicationClient::SendSpeedTestPacket (uint32_t send_size, uint32_t
     }
 
     StringExtractorGDBRemote response;
-    if (SendPacketAndWaitForResponse (packet.GetData(), packet.GetSize(), response, false))
-    {
-        if (response.IsUnsupportedResponse())
-            return false;
-        return true;
-    }
+    return SendPacketAndWaitForResponse (packet.GetData(), packet.GetSize(), response, false) > 0;
     return false;
 }
 
@@ -1588,13 +1579,15 @@ GDBRemoteCommunicationClient::GetThreadStopInfo (uint32_t tid, StringExtractorGD
         assert (packet_len < sizeof(packet));
         if (SendPacketAndWaitForResponse(packet, packet_len, response, false))
         {
-            if (response.IsUnsupportedResponse())
-                m_supports_qThreadStopInfo = false;
-            else if (response.IsNormalResponse())
+            if (response.IsNormalResponse())
                 return true;
             else
                 return false;
         }
+        else
+        {
+            m_supports_qThreadStopInfo = false;
+        }
     }
     if (SetCurrentThread (tid))
         return GetStopReply (response);
@@ -1630,20 +1623,21 @@ GDBRemoteCommunicationClient::SendGDBStoppointTypePacket (GDBStoppointType type,
     {
         if (response.IsOKResponse())
             return 0;
-        if (response.IsUnsupportedResponse())
-        {
-            switch (type)
-            {
-                case eBreakpointSoftware:   m_supports_z0 = false; break;
-                case eBreakpointHardware:   m_supports_z1 = false; break;
-                case eWatchpointWrite:      m_supports_z2 = false; break;
-                case eWatchpointRead:       m_supports_z3 = false; break;
-                case eWatchpointReadWrite:  m_supports_z4 = false; break;
-                default:                    break;
-            }
-        }
         else if (response.IsErrorResponse())
             return response.GetError();
     }
+    else
+    {
+        switch (type)
+        {
+            case eBreakpointSoftware:   m_supports_z0 = false; break;
+            case eBreakpointHardware:   m_supports_z1 = false; break;
+            case eWatchpointWrite:      m_supports_z2 = false; break;
+            case eWatchpointRead:       m_supports_z3 = false; break;
+            case eWatchpointReadWrite:  m_supports_z4 = false; break;
+            default:                    break;
+        }
+    }
+
     return UINT8_MAX;
 }