[llvm-dev] Invalid Signature of orc::RTDyldObjectLinkingLayer::NotifyLoadedFtor

[Stefan Gränitz via llvm-dev]

Hi all, hi Lang

It's a little late to report issues for release_50, but I just found
that thing while porting my JitFromScratch examples to 5.0.
This is a really nifty detail, but (if I'm not mistaken) the function
signature of RTDyldObjectLinkingLayer::NotifyLoadedFtor is incorrect:

$ grep -h -r -A 1 "using NotifyLoadedFtor"
./include/llvm/ExecutionEngine/Orc/RTDyldObjectLinkingLayer.h
  using NotifyLoadedFtor = std::function<void(ObjHandleT, const
ObjectPtr &Obj,
                                              const LoadedObjectInfo &)>;
                                                    ^^^^^^^^^^^^^^^^
It refers to llvm::LoadedObjectInfo base class in llvm/DebugInfo/DIContext.h
instead of   llvm::RuntimeDyld::LoadedObjectInfo in
llvm/ExecutionEngine/RuntimeDyld.h

I think it should actually use the derived
RuntimeDyld::LoadedObjectInfo, as this is what listeners expect:

$ grep -h -r -A 1 "NotifyObjectEmitted("
./include/llvm/ExecutionEngine/JITEventListener.h
  virtual void NotifyObjectEmitted(const object::ObjectFile &Obj,
                                   const RuntimeDyld::LoadedObjectInfo
&L) {}

It doesn't break OrcMCJITReplacement as it duplicates the issue and the
Info parameter remains unused:

$ grep -h -r -A 4 -B 2 "const LoadedObjectInfo &Info"
./lib/ExecutionEngine/Orc/OrcMCJITReplacement.h
    void operator()(RTDyldObjectLinkingLayerBase::ObjHandleT H,
                    const RTDyldObjectLinkingLayer::ObjectPtr &Obj,
                    const LoadedObjectInfo &Info) const {
      M.UnfinalizedSections[H] =
std::move(M.SectionsAllocatedSinceLastLoad);
      M.SectionsAllocatedSinceLastLoad = SectionAddrSet();
      M.MemMgr->notifyObjectLoaded(&M, *Obj->getBinary());
    }

OrcLazyJIT in lli on the other hand doesn't make use of the
notification.It can however be reproducedthere too:

diff --git a/tools/lli/OrcLazyJIT.h b/tools/lli/OrcLazyJIT.h
index 47a2acc4d7e..41a7c99413b 100644
--- a/tools/lli/OrcLazyJIT.h
+++ b/tools/lli/OrcLazyJIT.h
@@ -62,7 +62,11 @@ public:
              bool InlineStubs)
       : TM(std::move(TM)), DL(this->TM->createDataLayout()),
        CCMgr(std::move(CCMgr)),
-       ObjectLayer([]() { return
std::make_shared<SectionMemoryManager>(); }),
+       ObjectLayer([]() { return
std::make_shared<SectionMemoryManager>(); },
+              [this](llvm::orc::RTDyldObjectLinkingLayerBase::ObjHandleT,
+                     const
llvm::orc::RTDyldObjectLinkingLayerBase::ObjectPtr &obj,
+                     const llvm::RuntimeDyld::LoadedObjectInfo &info) {
+              }),
         CompileLayer(ObjectLayer, orc::SimpleCompiler(*this->TM)),
         IRDumpLayer(CompileLayer, createDebugDumper()),
         CODLayer(IRDumpLayer, extractSingleFunction, *this->CCMgr,

Diagnostic message:
error: no matching constructor for initialization of 'ObjLayerT' (aka
'llvm::orc::RTDyldObjectLinkingLayer')
        ObjectLayer([]() { return
std::make_shared<SectionMemoryManager>(); },
        ^          
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
In file included from /llvm50/llvm/tools/lli/OrcLazyJIT.cpp:10:
In file included from /llvm50/llvm/tools/lli/OrcLazyJIT.h:28:
/llvm50/llvm/include/llvm/ExecutionEngine/Orc/RTDyldObjectLinkingLayer.h:237:3:
note: candidate constructor not viable: no known conversion from
'(lambda at /llvm50/llvm/tools/lli/OrcLazyJIT.h:66:15)' to
'NotifyLoadedFtor' (aka 'function<void ([...], [...], const
llvm::LoadedObjectInfo &)>') for 2nd argument


Can it still be fixed? The patch is a 13 character one-liner:

diff --git a/include/llvm/ExecutionEngine/Orc/RTDyldObjectLinkingLayer.h
b/include/llvm/ExecutionEngine/Orc/RTDyldObjectLinkingLayer.h
index e1016ef95f0..fcf00fbc462 100644
--- a/include/llvm/ExecutionEngine/Orc/RTDyldObjectLinkingLayer.h
+++ b/include/llvm/ExecutionEngine/Orc/RTDyldObjectLinkingLayer.h
@@ -100,7 +100,7 @@ public:
 
   /// @brief Functor for receiving object-loaded notifications.
   using NotifyLoadedFtor = std::function<void(ObjHandleT, const
ObjectPtr &Obj,
-                                              const LoadedObjectInfo &)>;
+                                              const
RuntimeDyld::LoadedObjectInfo &)>;
 
   /// @brief Functor for receiving finalization notifications.
   using NotifyFinalizedFtor = std::function<void(ObjHandleT)>;
diff --git a/tools/lli/OrcLazyJIT.h b/tools/lli/OrcLazyJIT.h
index 47a2acc4d7e..41a7c99413b 100644

Opinions?

Cheers,
Stefan

-- 
https://weliveindetail.github.io/blog/
https://cryptup.org/pub/stefan.graenitz@gmail.com