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

lib/ExecutionEngine/ExecutionEngine.cpp

@@ -14,6 +14,7 @@
 
 #define DEBUG_TYPE "jit"
 #include "llvm/ExecutionEngine/ExecutionEngine.h"
+#include "llvm/ExecutionEngine/JITMemoryManager.h"
 #include "llvm/ADT/SmallString.h"
 #include "llvm/ADT/Statistic.h"
 #include "llvm/ExecutionEngine/GenericValue.h"
@@ -47,7 +48,7 @@ ExecutionEngine *(*ExecutionEngine::JITCtor)(
 ExecutionEngine *(*ExecutionEngine::MCJITCtor)(
   Module *M,
   std::string *ErrorStr,
-  JITMemoryManager *JMM,
+  RTDyldMemoryManager *MCJMM,
   bool GVsWithCode,
   TargetMachine *TM) = 0;
 ExecutionEngine *(*ExecutionEngine::InterpCtor)(Module *M,
@@ -455,10 +456,12 @@ ExecutionEngine *EngineBuilder::create(TargetMachine *TM) {
   if (sys::DynamicLibrary::LoadLibraryPermanently(0, ErrorStr))
     return 0;
 
+  assert(!(JMM && MCJMM));
+  
   // If the user specified a memory manager but didn't specify which engine to
   // create, we assume they only want the JIT, and we fail if they only want
   // the interpreter.
-  if (JMM) {
+  if (JMM || MCJMM) {
     if (WhichEngine & EngineKind::JIT)
       WhichEngine = EngineKind::JIT;
     else {
@@ -467,6 +470,14 @@ ExecutionEngine *EngineBuilder::create(TargetMachine *TM) {
       return 0;
     }
   }
+  
+  if (MCJMM && ! UseMCJIT) {
+    if (ErrorStr)
+      *ErrorStr =
+        "Cannot create a legacy JIT with a runtime dyld memory "
+        "manager.";
+    return 0;
+  }
 
   // Unless the interpreter was explicitly selected or the JIT is not linked,
   // try making a JIT.
@@ -480,7 +491,7 @@ ExecutionEngine *EngineBuilder::create(TargetMachine *TM) {
 
     if (UseMCJIT && ExecutionEngine::MCJITCtor) {
       ExecutionEngine *EE =
-        ExecutionEngine::MCJITCtor(M, ErrorStr, JMM,
+        ExecutionEngine::MCJITCtor(M, ErrorStr, MCJMM ? MCJMM : JMM,
                                    AllocateGVsWithCode, TheTM.take());
       if (EE) return EE;
     } else if (ExecutionEngine::JITCtor) {

lib/ExecutionEngine/MCJIT/MCJIT.cpp

@@ -39,7 +39,7 @@ extern "C" void LLVMLinkInMCJIT() {
 
 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 @@ ExecutionEngine *MCJIT::createJIT(Module *M,
   // 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());
 }

lib/ExecutionEngine/MCJIT/MCJIT.h

@@ -98,7 +98,7 @@ public:
 
   static ExecutionEngine *createJIT(Module *M,
                                     std::string *ErrorStr,
-                                    JITMemoryManager *JMM,
+                                    RTDyldMemoryManager *MemMgr,
                                     bool GVsWithCode,
                                     TargetMachine *TM);