[weak vtables] Remove a bunch of weak vtables

This patch removes most of the trivial cases of weak vtables by pinning them to
a single object file. The memory leaks in this version have been fixed. Thanks
Alexey for pointing them out.

Differential Revision: http://llvm-reviews.chandlerc.com/D2068

Reviewed by Andy

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@195064 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 3 insertions, 2 deletions

diff --git a/include/llvm/Support/ValueHandle.h b/include/llvm/Support/ValueHandle.h
index b49341c3ff..bc02ba31b9 100644
--- a/include/llvm/Support/ValueHandle.h
+++ b/include/llvm/Support/ValueHandle.h
@@ -339,6 +339,7 @@ public:
 /// rearrange itself when the pointer changes).  Unlike ValueHandleBase, this
 /// class has a vtable and a virtual destructor.
 class CallbackVH : public ValueHandleBase {
+  virtual void anchor();
 protected:
   CallbackVH(const CallbackVH &RHS)
     : ValueHandleBase(Callback, RHS) {}
@@ -365,13 +366,13 @@ public:
   ///
   /// All implementations must remove the reference from this object to the
   /// Value that's being destroyed.
-  virtual void deleted();
+  virtual void deleted() { setValPtr(NULL); }
 
   /// Called when this->getValPtr()->replaceAllUsesWith(new_value) is called,
   /// _before_ any of the uses have actually been replaced.  If WeakVH were
   /// implemented as a CallbackVH, it would use this method to call
   /// setValPtr(new_value).  AssertingVH would do nothing in this method.
-  virtual void allUsesReplacedWith(Value *);
+  virtual void allUsesReplacedWith(Value *) {}
 };
 
 } // End llvm namespace