[ORC] Add a pair of ORC layers that forward object-layer operations via RPC.

This patch introduces RemoteObjectClientLayer and RemoteObjectServerLayer,
which can be used to forward ORC object-layer operations from a JIT stack in
the client to a JIT stack (consisting only of object-layers) in the server.

This is a new way to support remote-JITing in LLVM. The previous approach
(supported by OrcRemoteTargetClient and OrcRemoteTargetServer) used a
remote-mapping memory manager that sat "beneath" the JIT stack and sent
fully-relocated binary blobs to the server. The main advantage of the new
approach is that relocatable objects can be cached on the server and re-used
(if the code that they represent hasn't changed), whereas fully-relocated blobs
can not (since the addresses they have been permanently bound to will change
from run to run).

llvm-svn: 312511

1 files changed, 2 insertions, 0 deletions

diff --git a/llvm/lib/ExecutionEngine/Orc/OrcError.cpp b/llvm/lib/ExecutionEngine/Orc/OrcError.cpp
index df2d320e0f7..c218cb9a523 100644
--- a/llvm/lib/ExecutionEngine/Orc/OrcError.cpp
+++ b/llvm/lib/ExecutionEngine/Orc/OrcError.cpp
@@ -54,6 +54,8 @@ public:
     case OrcErrorCode::UnknownErrorCodeFromRemote:
       return "Unknown error returned from remote RPC function "
              "(Use StringError to get error message)";
+    case OrcErrorCode::UnknownResourceHandle:
+      return "Unknown resource handle";
     }
     llvm_unreachable("Unhandled error code");
   }