[MCJIT] Re-enable GDB registration (temporarily disabled in r222811), but check

that we actually have an object to register first.

For MachO objects, RuntimeDyld::LoadedObjectInfo::getObjectForDebug returns an
empty OwningBinary<ObjectFile> which was causing crashes in the GDB registration
code.

llvm-svn: 222812

2 files changed, 6 insertions, 0 deletions

diff --git a/llvm/lib/ExecutionEngine/MCJIT/MCJIT.cpp b/llvm/lib/ExecutionEngine/MCJIT/MCJIT.cpp
index 490fbb3df99..58cf4e5e6dd 100644
--- a/llvm/lib/ExecutionEngine/MCJIT/MCJIT.cpp
+++ b/llvm/lib/ExecutionEngine/MCJIT/MCJIT.cpp
@@ -75,6 +75,7 @@ MCJIT::MCJIT(std::unique_ptr<Module> M, std::unique_ptr<TargetMachine> tm,
 
   OwnedModules.addModule(std::move(First));
   setDataLayout(TM->getSubtargetImpl()->getDataLayout());
+  RegisterJITEventListener(JITEventListener::createGDBRegistrationListener());
 }
 
 MCJIT::~MCJIT() {
diff --git a/llvm/lib/ExecutionEngine/RuntimeDyld/GDBRegistrationListener.cpp b/llvm/lib/ExecutionEngine/RuntimeDyld/GDBRegistrationListener.cpp
index 641d3a26270..13d5672a82b 100644
--- a/llvm/lib/ExecutionEngine/RuntimeDyld/GDBRegistrationListener.cpp
+++ b/llvm/lib/ExecutionEngine/RuntimeDyld/GDBRegistrationListener.cpp
@@ -151,6 +151,11 @@ void GDBJITRegistrationListener::NotifyObjectEmitted(
                                        const RuntimeDyld::LoadedObjectInfo &L) {
 
   OwningBinary<ObjectFile> DebugObj = L.getObjectForDebug(Object);
+
+  // Bail out if debug objects aren't supported.
+  if (!DebugObj.getBinary())
+    return;
+
   const char *Buffer = DebugObj.getBinary()->getMemoryBufferRef().getBufferStart();
   size_t      Size = DebugObj.getBinary()->getMemoryBufferRef().getBufferSize();