lldb-server: add support for binary memory reads

Summary:
This commit adds support for binary memory reads ($x) to lldb-server. It also removes the "0x"
prefix from the $x client packet, to make it more compatible with the old $m packet. This allows
us to use almost the same code for handling both packet types. I have verified that debugserver
correctly handles $x packets even without the leading "0x". I have added a test which verifies
that the stub returns the same memory contents for both kinds of memory reads ($x and $m).

Reviewers: tberghammer, jasonmolenda

Subscribers: iancottrell, lldb-commits

Differential Revision: http://reviews.llvm.org/D13695

llvm-svn: 250295

1 files changed, 15 insertions, 5 deletions

diff --git a/lldb/source/Plugins/Process/gdb-remote/GDBRemoteCommunicationServerLLGS.cpp b/lldb/source/Plugins/Process/gdb-remote/GDBRemoteCommunicationServerLLGS.cpp
index 0df7714..b0d931b 100644
--- a/lldb/source/Plugins/Process/gdb-remote/GDBRemoteCommunicationServerLLGS.cpp
+++ b/lldb/source/Plugins/Process/gdb-remote/GDBRemoteCommunicationServerLLGS.cpp
@@ -113,7 +113,7 @@ GDBRemoteCommunicationServerLLGS::RegisterPacketHandlers()
     RegisterMemberFunctionHandler(StringExtractorGDBRemote::eServerPacketType_interrupt,
                                   &GDBRemoteCommunicationServerLLGS::Handle_interrupt);
     RegisterMemberFunctionHandler(StringExtractorGDBRemote::eServerPacketType_m,
-                                  &GDBRemoteCommunicationServerLLGS::Handle_m);
+                                  &GDBRemoteCommunicationServerLLGS::Handle_memory_read);
     RegisterMemberFunctionHandler(StringExtractorGDBRemote::eServerPacketType_M,
                                   &GDBRemoteCommunicationServerLLGS::Handle_M);
     RegisterMemberFunctionHandler(StringExtractorGDBRemote::eServerPacketType_p,
@@ -164,6 +164,8 @@ GDBRemoteCommunicationServerLLGS::RegisterPacketHandlers()
                                   &GDBRemoteCommunicationServerLLGS::Handle_vCont);
     RegisterMemberFunctionHandler(StringExtractorGDBRemote::eServerPacketType_vCont_actions,
                                   &GDBRemoteCommunicationServerLLGS::Handle_vCont_actions);
+    RegisterMemberFunctionHandler(StringExtractorGDBRemote::eServerPacketType_x,
+                                  &GDBRemoteCommunicationServerLLGS::Handle_memory_read);
     RegisterMemberFunctionHandler(StringExtractorGDBRemote::eServerPacketType_Z,
                                   &GDBRemoteCommunicationServerLLGS::Handle_Z);
     RegisterMemberFunctionHandler(StringExtractorGDBRemote::eServerPacketType_z,
@@ -1975,7 +1977,7 @@ GDBRemoteCommunicationServerLLGS::Handle_interrupt (StringExtractorGDBRemote &pa
 }
 
 GDBRemoteCommunication::PacketResult
-GDBRemoteCommunicationServerLLGS::Handle_m (StringExtractorGDBRemote &packet)
+GDBRemoteCommunicationServerLLGS::Handle_memory_read(StringExtractorGDBRemote &packet)
 {
     Log *log (GetLogIfAnyCategoriesSet(LIBLLDB_LOG_PROCESS));
 
@@ -2008,7 +2010,7 @@ GDBRemoteCommunicationServerLLGS::Handle_m (StringExtractorGDBRemote &packet)
     {
         if (log)
             log->Printf ("GDBRemoteCommunicationServerLLGS::%s nothing to read: zero-length packet", __FUNCTION__);
-        return PacketResult::Success;
+        return SendOKResponse();
     }
 
     // Allocate the response buffer.
@@ -2035,8 +2037,16 @@ GDBRemoteCommunicationServerLLGS::Handle_m (StringExtractorGDBRemote &packet)
     }
 
     StreamGDBRemote response;
-    for (size_t i = 0; i < bytes_read; ++i)
-        response.PutHex8(buf[i]);
+    packet.SetFilePos(0);
+    char kind = packet.GetChar('?');
+    if (kind == 'x')
+        response.PutEscapedBytes(buf.data(), byte_count);
+    else
+    {
+        assert(kind == 'm');
+        for (size_t i = 0; i < bytes_read; ++i)
+            response.PutHex8(buf[i]);
+    }
 
     return SendPacketNoLock(response.GetData(), response.GetSize());
 }