+/// RemoveFromUseList - Remove this ValueHandle from its current use list.
+void ValueHandleBase::RemoveFromUseList() {
+ assert(VP && VP->HasValueHandle && "Pointer doesn't have a use list!");
+
+ // Unlink this from its use list.
+ ValueHandleBase **PrevPtr = getPrevPtr();
+ assert(*PrevPtr == this && "List invariant broken");
+
+ *PrevPtr = Next;
+ if (Next) {
+ assert(Next->getPrevPtr() == &Next && "List invariant broken");
+ Next->setPrevPtr(PrevPtr);
+ return;
+ }
+
+ // If the Next pointer was null, then it is possible that this was the last
+ // ValueHandle watching VP. If so, delete its entry from the ValueHandles
+ // map.
+ sys::SmartScopedWriter<true> Writer(&*ValueHandlesLock);
+ ValueHandlesTy &Handles = *ValueHandles;
+ if (Handles.isPointerIntoBucketsArray(PrevPtr)) {
+ Handles.erase(VP);
+ VP->HasValueHandle = false;
+ }
+}
+
+
+void ValueHandleBase::ValueIsDeleted(Value *V) {
+ assert(V->HasValueHandle && "Should only be called if ValueHandles present");
+
+ // Get the linked list base, which is guaranteed to exist since the
+ // HasValueHandle flag is set.
+ ValueHandlesLock->reader_acquire();
+ ValueHandleBase *Entry = (*ValueHandles)[V];
+ ValueHandlesLock->reader_release();
+ assert(Entry && "Value bit set but no entries exist");
+
+ while (Entry) {
+ // Advance pointer to avoid invalidation.
+ ValueHandleBase *ThisNode = Entry;
+ Entry = Entry->Next;
+
+ switch (ThisNode->getKind()) {
+ case Assert:
+#ifndef NDEBUG // Only in -g mode...
+ cerr << "While deleting: " << *V->getType() << " %" << V->getNameStr()
+ << "\n";
+#endif
+ cerr << "An asserting value handle still pointed to this value!\n";
+ abort();
+ case Weak:
+ // Weak just goes to null, which will unlink it from the list.
+ ThisNode->operator=(0);
+ break;
+ case Callback:
+ // Forward to the subclass's implementation.
+ static_cast<CallbackVH*>(ThisNode)->deleted();
+ break;
+ }
+ }
+
+ // All callbacks and weak references should be dropped by now.
+ assert(!V->HasValueHandle && "All references to V were not removed?");
+}
+
+
+void ValueHandleBase::ValueIsRAUWd(Value *Old, Value *New) {
+ assert(Old->HasValueHandle &&"Should only be called if ValueHandles present");
+ assert(Old != New && "Changing value into itself!");
+
+ // Get the linked list base, which is guaranteed to exist since the
+ // HasValueHandle flag is set.
+ ValueHandlesLock->reader_acquire();
+ ValueHandleBase *Entry = (*ValueHandles)[Old];
+ ValueHandlesLock->reader_release();
+ assert(Entry && "Value bit set but no entries exist");
+
+ while (Entry) {
+ // Advance pointer to avoid invalidation.
+ ValueHandleBase *ThisNode = Entry;
+ Entry = Entry->Next;
+
+ switch (ThisNode->getKind()) {
+ case Assert:
+ // Asserting handle does not follow RAUW implicitly.
+ break;
+ case Weak:
+ // Weak goes to the new value, which will unlink it from Old's list.
+ ThisNode->operator=(New);
+ break;
+ case Callback:
+ // Forward to the subclass's implementation.
+ static_cast<CallbackVH*>(ThisNode)->allUsesReplacedWith(New);
+ break;
+ }
+ }
+}
+
+/// ~CallbackVH. Empty, but defined here to avoid emitting the vtable
+/// more than once.
+CallbackVH::~CallbackVH() {}
+
+