Fix a threaded LLVM bug due the need for operator= on reference counted AttrListImpl's. It might
be possible to implement this very carefully to allow a lock-free implementation while still
avoiding illegal interleavings, but I haven't been able to figure one out.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@114046 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/VMCore/Attributes.cpp b/lib/VMCore/Attributes.cpp
index a000aee..3422faf 100644
--- a/lib/VMCore/Attributes.cpp
+++ b/lib/VMCore/Attributes.cpp
@@ -195,6 +195,7 @@
}
const AttrListPtr &AttrListPtr::operator=(const AttrListPtr &RHS) {
+ sys::SmartScopedLock<true> Lock(*ALMutex);
if (AttrList == RHS.AttrList) return *this;
if (AttrList) AttrList->DropRef();
AttrList = RHS.AttrList;