Revising the MCJIT ObjectCache interface to allow subclasses to avoid retaining references to returned objects

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@185221 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/unittests/ExecutionEngine/MCJIT/MCJITObjectCacheTest.cpp b/unittests/ExecutionEngine/MCJIT/MCJITObjectCacheTest.cpp
index 32fc292..2cc045b 100644
--- a/unittests/ExecutionEngine/MCJIT/MCJITObjectCacheTest.cpp
+++ b/unittests/ExecutionEngine/MCJIT/MCJITObjectCacheTest.cpp
@@ -45,6 +45,16 @@
     ObjMap[ModuleID] = copyBuffer(Obj);
   }
 
+  virtual MemoryBuffer* getObject(const Module* M) {
+    const MemoryBuffer* BufferFound = getObjectInternal(M);
+    ModulesLookedUp.insert(M->getModuleIdentifier());
+    if (!BufferFound)
+      return NULL;
+    // Our test cache wants to maintain ownership of its object buffers
+    // so we make a copy here for the execution engine.
+    return MemoryBuffer::getMemBufferCopy(BufferFound->getBuffer());
+  }
+
   // Test-harness-specific functions
   bool wereDuplicatesInserted() { return DuplicateInserted; }
 
@@ -62,13 +72,6 @@
     return it->second;
   }
 
-protected:
-  virtual const MemoryBuffer* getObject(const Module* M) {
-    const MemoryBuffer* BufferFound = getObjectInternal(M);
-    ModulesLookedUp.insert(M->getModuleIdentifier());
-    return BufferFound;
-  }
-
 private:
   MemoryBuffer *copyBuffer(const MemoryBuffer *Buf) {
     // Create a local copy of the buffer.