[Orc] Refactor ObjectLinkingLayer::addObjectSet to defer loading objects until

they're needed.

Prior to this patch objects were loaded (via RuntimeDyld::loadObject) when they
were added to the ObjectLinkingLayer, but were not relocated and finalized until
a symbol address was requested. In the interim, another object could be loaded
and finalized with the same memory manager, causing relocation/finalization of
the first object to fail (as the first finalization call may have marked the
allocated memory for the first object read-only).

By deferring the loadObject call (and subsequent memory allocations) until an
object file is needed we can avoid prematurely finalizing memory.

llvm-svn: 258185

1 files changed, 17 insertions, 7 deletions

diff --git a/llvm/lib/ExecutionEngine/Orc/OrcMCJITReplacement.h b/llvm/lib/ExecutionEngine/Orc/OrcMCJITReplacement.h
index 2ab70a9fee8..896c184d440 100644
--- a/llvm/lib/ExecutionEngine/Orc/OrcMCJITReplacement.h
+++ b/llvm/lib/ExecutionEngine/Orc/OrcMCJITReplacement.h
@@ -178,11 +178,10 @@ public:
   }
 
   void addObjectFile(object::OwningBinary<object::ObjectFile> O) override {
-    std::unique_ptr<object::ObjectFile> Obj;
-    std::unique_ptr<MemoryBuffer> Buf;
-    std::tie(Obj, Buf) = O.takeBinary();
-    std::vector<std::unique_ptr<object::ObjectFile>> Objs;
-    Objs.push_back(std::move(Obj));
+    std::vector<std::unique_ptr<object::OwningBinary<object::ObjectFile>>> Objs;
+    Objs.push_back(
+      llvm::make_unique<object::OwningBinary<object::ObjectFile>>(
+        std::move(O)));
     ObjectLayer.addObjectSet(std::move(Objs), &MemMgr, &Resolver);
   }
 
@@ -284,12 +283,12 @@ private:
 
   class NotifyObjectLoadedT {
   public:
-    typedef std::vector<std::unique_ptr<object::ObjectFile>> ObjListT;
     typedef std::vector<std::unique_ptr<RuntimeDyld::LoadedObjectInfo>>
         LoadedObjInfoListT;
 
     NotifyObjectLoadedT(OrcMCJITReplacement &M) : M(M) {}
 
+    template <typename ObjListT>
     void operator()(ObjectLinkingLayerBase::ObjSetHandleT H,
                     const ObjListT &Objects,
                     const LoadedObjInfoListT &Infos) const {
@@ -298,10 +297,21 @@ private:
       assert(Objects.size() == Infos.size() &&
              "Incorrect number of Infos for Objects.");
       for (unsigned I = 0; I < Objects.size(); ++I)
-        M.MemMgr.notifyObjectLoaded(&M, *Objects[I]);
+        M.MemMgr.notifyObjectLoaded(&M, getObject(*Objects[I]));
     }
 
   private:
+
+    static const object::ObjectFile& getObject(const object::ObjectFile &Obj) {
+      return Obj;
+    }
+
+    template <typename ObjT>
+    static const object::ObjectFile&
+    getObject(const object::OwningBinary<ObjT> &Obj) {
+      return *Obj.getBinary();
+    }
+
     OrcMCJITReplacement &M;
   };