SectionMemoryManager shouldn't be a JITMemoryManager. Previously, the 
EngineBuilder interface required a JITMemoryManager even if it was being used 
to construct an MCJIT. But the MCJIT actually wants a RTDyldMemoryManager. 
Consequently, the SectionMemoryManager, which is meant for MCJIT, derived 
from the JITMemoryManager and then stubbed out a bunch of JITMemoryManager 
methods that weren't relevant to the MCJIT.

This patch fixes the situation: it teaches the EngineBuilder that 
RTDyldMemoryManager is a supertype of JITMemoryManager, and that it's 
appropriate to pass a RTDyldMemoryManager instead of a JITMemoryManager if 
we're using the MCJIT. This allows us to remove the stub methods from 
SectionMemoryManager, and make SectionMemoryManager a direct subtype of 
RTDyldMemoryManager.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@181820 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/ExecutionEngine/MCJIT/MCJIT.cpp b/lib/ExecutionEngine/MCJIT/MCJIT.cpp
index 38aa547..ced5672 100644
--- a/lib/ExecutionEngine/MCJIT/MCJIT.cpp
+++ b/lib/ExecutionEngine/MCJIT/MCJIT.cpp
@@ -39,7 +39,7 @@
 
 ExecutionEngine *MCJIT::createJIT(Module *M,
                                   std::string *ErrorStr,
-                                  JITMemoryManager *JMM,
+                                  RTDyldMemoryManager *MemMgr,
                                   bool GVsWithCode,
                                   TargetMachine *TM) {
   // Try to register the program as a source of symbols to resolve against.
@@ -47,14 +47,14 @@
   // FIXME: Don't do this here.
   sys::DynamicLibrary::LoadLibraryPermanently(0, NULL);
 
-  return new MCJIT(M, TM, JMM ? JMM : new SectionMemoryManager(), GVsWithCode);
+  return new MCJIT(M, TM, MemMgr ? MemMgr : new SectionMemoryManager(),
+                   GVsWithCode);
 }
 
 MCJIT::MCJIT(Module *m, TargetMachine *tm, RTDyldMemoryManager *MM,
              bool AllocateGVsWithCode)
-  : ExecutionEngine(m), TM(tm), Ctx(0),
-    MemMgr(MM ? MM : new SectionMemoryManager()), Dyld(MemMgr),
-    IsLoaded(false), M(m), ObjCache(0)  {
+  : ExecutionEngine(m), TM(tm), Ctx(0), MemMgr(MM), Dyld(MM),
+    IsLoaded(false), M(m), ObjCache(0) {
 
   setDataLayout(TM->getDataLayout());
 }