From 81ab23434402703603b7f99ca036f21c27c9c100 Mon Sep 17 00:00:00 2001
From: Lang Hames <lhames@gmail.com>
Date: Mon, 2 Feb 2015 04:32:17 +0000
Subject: [PATCH 1/1] [Orc] Make the ObjectLinkingLayer take ownership of
 object files until finalization time.

As currently implemented, RuntimeDyldELF requires the original object
file to be avaible when relocations are being resolved. This patch
ensures that the ObjectLinkingLayer preserves it until then. In the
future RuntimeDyldELF should be rewritten to remove this requirement, at
which point this patch can be reverted.

Regression test cases for Orc (which include coverage of this bug) will
be committed shortly.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@227778 91177308-0d34-0410-b5e6-96231b3b80d8
---
 .../llvm/ExecutionEngine/Orc/IRCompileLayer.h |  7 ++++++-
 .../ExecutionEngine/Orc/ObjectLinkingLayer.h  | 20 +++++++++++++++++++
 2 files changed, 26 insertions(+), 1 deletion(-)

diff --git a/include/llvm/ExecutionEngine/Orc/IRCompileLayer.h b/include/llvm/ExecutionEngine/Orc/IRCompileLayer.h
index f81af6fb7d0..e16ff8d3a39 100644
--- a/include/llvm/ExecutionEngine/Orc/IRCompileLayer.h
+++ b/include/llvm/ExecutionEngine/Orc/IRCompileLayer.h
@@ -76,7 +76,12 @@ public:
       Buffers.push_back(std::move(Buffer));
     }
 
-    return BaseLayer.addObjectSet(std::move(Objects), std::move(MM));
+    ModuleSetHandleT H =
+      BaseLayer.addObjectSet(Objects, std::move(MM));
+
+    BaseLayer.takeOwnershipOfBuffers(H, std::move(Buffers));
+
+    return H;
   }
 
   /// @brief Remove the module set associated with the handle H.
diff --git a/include/llvm/ExecutionEngine/Orc/ObjectLinkingLayer.h b/include/llvm/ExecutionEngine/Orc/ObjectLinkingLayer.h
index 03b43aa3272..957fec40ad3 100644
--- a/include/llvm/ExecutionEngine/Orc/ObjectLinkingLayer.h
+++ b/include/llvm/ExecutionEngine/Orc/ObjectLinkingLayer.h
@@ -61,6 +61,7 @@ protected:
       RTDyld->resolveRelocations();
       RTDyld->registerEHFrames();
       MM->finalizeMemory();
+      OwnedBuffers.clear();
       State = Finalized;
     }
 
@@ -70,10 +71,19 @@ protected:
       RTDyld->mapSectionAddress(LocalAddress, TargetAddress);
     }
 
+    void takeOwnershipOfBuffer(std::unique_ptr<MemoryBuffer> B) {
+      OwnedBuffers.push_back(std::move(B));
+    }
+
   private:
     std::unique_ptr<RTDyldMemoryManager> MM;
     std::unique_ptr<RuntimeDyld> RTDyld;
     enum { Raw, Finalizing, Finalized } State;
+
+    // FIXME: This ownership hack only exists because RuntimeDyldELF still
+    //        wants to be able to inspect the original object when resolving
+    //        relocations. As soon as that can be fixed this should be removed.
+    std::vector<std::unique_ptr<MemoryBuffer>> OwnedBuffers;
   };
 
   typedef std::list<LinkedObjectSet> LinkedObjectSetListT;
@@ -81,6 +91,16 @@ protected:
 public:
   /// @brief Handle to a set of loaded objects.
   typedef LinkedObjectSetListT::iterator ObjSetHandleT;
+
+  // Ownership hack.
+  // FIXME: Remove this as soon as RuntimeDyldELF can apply relocations without
+  //        referencing the original object.
+  template <typename OwningMBSet>
+  void takeOwnershipOfBuffers(ObjSetHandleT H, OwningMBSet MBs) {
+    for (auto &MB : MBs)
+      H->takeOwnershipOfBuffer(std::move(MB));
+  }
+
 };
 
 /// @brief Default (no-op) action to perform when loading objects.
-- 
2.34.1