-Wdeprecated-clean: Fix cases of violating the rule of 5 in ways that are deprecated in C++11

Various value handles needed to be copy constructible and copy
assignable (mostly for their use in DenseMap). But to avoid an API that
might allow accidental slicing, make these members protected in the base
class and make derived classes final (the special members become
implicitly public there - but disallowing further derived classes that
might be sliced to the intermediate type).

Might be worth having a warning a bit like -Wnon-virtual-dtor that
catches public move/copy assign/ctors in classes with virtual functions.
(suppressable in the same way - by making them protected in the base,
and making the derived classes final) Could be fancier and only diagnose
them when they're actually called, potentially.

Also allow a few default implementations where custom implementations
(especially with non-standard return types) were implemented.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@243909 91177308-0d34-0410-b5e6-96231b3b80d8

include/llvm/Analysis/AliasSetTracker.h

@@ -286,7 +286,7 @@ inline raw_ostream& operator<<(raw_ostream &OS, const AliasSet &AS) {
 class AliasSetTracker {
   /// CallbackVH - A CallbackVH to arrange for AliasSetTracker to be
   /// notified whenever a Value is deleted.
-  class ASTCallbackVH : public CallbackVH {
+  class ASTCallbackVH final : public CallbackVH {
     AliasSetTracker *AST;
     void deleted() override;
     void allUsesReplacedWith(Value *) override;

include/llvm/Analysis/AssumptionCache.h

@@ -140,7 +140,7 @@ public:
 class AssumptionCacheTracker : public ImmutablePass {
   /// A callback value handle applied to function objects, which we use to
   /// delete our cache of intrinsics for a function when it is deleted.
-  class FunctionCallbackVH : public CallbackVH {
+  class FunctionCallbackVH final : public CallbackVH {
     AssumptionCacheTracker *ACT;
     void deleted() override;
 

include/llvm/Analysis/IVUsers.h

@@ -34,7 +34,7 @@ class DataLayout;
 /// The Expr member keeps track of the expression, User is the actual user
 /// instruction of the operand, and 'OperandValToReplace' is the operand of
 /// the User that is the use.
-class IVStrideUse : public CallbackVH, public ilist_node<IVStrideUse> {
+class IVStrideUse final : public CallbackVH, public ilist_node<IVStrideUse> {
   friend class IVUsers;
 public:
   IVStrideUse(IVUsers *P, Instruction* U, Value *O)

include/llvm/Analysis/ScalarEvolution.h

@@ -210,7 +210,7 @@ namespace llvm {
   private:
     /// SCEVCallbackVH - A CallbackVH to arrange for ScalarEvolution to be
     /// notified whenever a Value is deleted.
-    class SCEVCallbackVH : public CallbackVH {
+    class SCEVCallbackVH final : public CallbackVH {
       ScalarEvolution *SE;
       void deleted() override;
       void allUsesReplacedWith(Value *New) override;

include/llvm/Analysis/ScalarEvolutionExpressions.h

@@ -404,7 +404,7 @@ namespace llvm {
   /// value, and only represent it as its LLVM Value.  This is the "bottom"
   /// value for the analysis.
   ///
-  class SCEVUnknown : public SCEV, private CallbackVH {
+  class SCEVUnknown final : public SCEV, private CallbackVH {
     friend class ScalarEvolution;
 
     // Implement CallbackVH.

include/llvm/IR/ValueHandle.h

@@ -52,13 +52,21 @@ protected:
     Weak
   };
 
+  ValueHandleBase(const ValueHandleBase &RHS)
+      : ValueHandleBase(RHS.PrevPair.getInt(), RHS) {}
+
+  ValueHandleBase(HandleBaseKind Kind, const ValueHandleBase &RHS)
+      : PrevPair(nullptr, Kind), Next(nullptr), V(RHS.V) {
+    if (isValid(V))
+      AddToExistingUseList(RHS.getPrevPtr());
+  }
+
 private:
   PointerIntPair<ValueHandleBase**, 2, HandleBaseKind> PrevPair;
   ValueHandleBase *Next;
 
   Value* V;
 
-  ValueHandleBase(const ValueHandleBase&) = delete;
 public:
   explicit ValueHandleBase(HandleBaseKind Kind)
     : PrevPair(nullptr, Kind), Next(nullptr), V(nullptr) {}
@@ -67,11 +75,7 @@ public:
     if (isValid(V))
       AddToUseList();
   }
-  ValueHandleBase(HandleBaseKind Kind, const ValueHandleBase &RHS)
-    : PrevPair(nullptr, Kind), Next(nullptr), V(RHS.V) {
-    if (isValid(V))
-      AddToExistingUseList(RHS.getPrevPtr());
-  }
+
   ~ValueHandleBase() {
     if (isValid(V))
       RemoveFromUseList();
@@ -145,6 +149,8 @@ public:
   WeakVH(const WeakVH &RHS)
     : ValueHandleBase(Weak, RHS) {}
 
+  WeakVH &operator=(const WeakVH &RHS) = default;
+
   Value *operator=(Value *RHS) {
     return ValueHandleBase::operator=(RHS);
   }
@@ -314,7 +320,6 @@ class TrackingVH : public ValueHandleBase {
 public:
   TrackingVH() : ValueHandleBase(Tracking) {}
   TrackingVH(ValueTy *P) : ValueHandleBase(Tracking, GetAsValue(P)) {}
-  TrackingVH(const TrackingVH &RHS) : ValueHandleBase(Tracking, RHS) {}
 
   operator ValueTy*() const {
     return getValPtr();
@@ -324,10 +329,6 @@ public:
     setValPtr(RHS);
     return getValPtr();
   }
-  ValueTy *operator=(const TrackingVH<ValueTy> &RHS) {
-    setValPtr(RHS.getValPtr());
-    return getValPtr();
-  }
 
   ValueTy *operator->() const { return getValPtr(); }
   ValueTy &operator*() const { return *getValPtr(); }
@@ -344,10 +345,9 @@ public:
 class CallbackVH : public ValueHandleBase {
   virtual void anchor();
 protected:
-  CallbackVH(const CallbackVH &RHS)
-    : ValueHandleBase(Callback, RHS) {}
-
-  virtual ~CallbackVH() {}
+  ~CallbackVH() = default;
+  CallbackVH(const CallbackVH &) = default;
+  CallbackVH &operator=(const CallbackVH &) = default;
 
   void setValPtr(Value *P) {
     ValueHandleBase::operator=(P);

include/llvm/IR/ValueMap.h

@@ -214,8 +214,8 @@ private:
 
 // This CallbackVH updates its ValueMap when the contained Value changes,
 // according to the user's preferences expressed through the Config object.
-template<typename KeyT, typename ValueT, typename Config>
-class ValueMapCallbackVH : public CallbackVH {
+template <typename KeyT, typename ValueT, typename Config>
+class ValueMapCallbackVH final : public CallbackVH {
   friend class ValueMap<KeyT, ValueT, Config>;
   friend struct DenseMapInfo<ValueMapCallbackVH>;
   typedef ValueMap<KeyT, ValueT, Config> ValueMapT;

lib/Analysis/CFLAliasAnalysis.cpp

@@ -153,15 +153,13 @@ struct FunctionInfo {
 
 struct CFLAliasAnalysis;
 
-struct FunctionHandle : public CallbackVH {
+struct FunctionHandle final : public CallbackVH {
   FunctionHandle(Function *Fn, CFLAliasAnalysis *CFLAA)
       : CallbackVH(Fn), CFLAA(CFLAA) {
     assert(Fn != nullptr);
     assert(CFLAA != nullptr);
   }
 
-  ~FunctionHandle() override {}
-
   void deleted() override { removeSelfFromCache(); }
   void allUsesReplacedWith(Value *) override { removeSelfFromCache(); }
 

lib/Analysis/LazyValueInfo.cpp

@@ -295,7 +295,7 @@ raw_ostream &operator<<(raw_ostream &OS, const LVILatticeVal &Val) {
 namespace {
   /// A callback value handle updates the cache when values are erased.
   class LazyValueInfoCache;
-  struct LVIValueHandle : public CallbackVH {
+  struct LVIValueHandle final : public CallbackVH {
     LazyValueInfoCache *Parent;
 
     LVIValueHandle(Value *V, LazyValueInfoCache *P)

lib/CodeGen/MachineModuleInfo.cpp

@@ -35,7 +35,7 @@ char MachineModuleInfo::ID = 0;
 MachineModuleInfoImpl::~MachineModuleInfoImpl() {}
 
 namespace llvm {
-class MMIAddrLabelMapCallbackPtr : CallbackVH {
+class MMIAddrLabelMapCallbackPtr final : CallbackVH {
   MMIAddrLabelMap *Map;
 public:
   MMIAddrLabelMapCallbackPtr() : Map(nullptr) {}

lib/ExecutionEngine/ExecutionEngine.cpp

@@ -95,7 +95,7 @@ ExecutionEngine::~ExecutionEngine() {
 namespace {
 /// \brief Helper class which uses a value handler to automatically deletes the
 /// memory block when the GlobalVariable is destroyed.
-class GVMemoryBlock : public CallbackVH {
+class GVMemoryBlock final : public CallbackVH {
   GVMemoryBlock(const GlobalVariable *GV)
     : CallbackVH(const_cast<GlobalVariable*>(GV)) {}
 

unittests/IR/ValueHandleTest.cpp

@@ -29,7 +29,7 @@ protected:
   }
 };
 
-class ConcreteCallbackVH : public CallbackVH {
+class ConcreteCallbackVH final : public CallbackVH {
 public:
   ConcreteCallbackVH(Value *V) : CallbackVH(V) {}
 };
@@ -235,7 +235,7 @@ TEST_F(ValueHandle, CallbackVH_Comparisons) {
 }
 
 TEST_F(ValueHandle, CallbackVH_CallbackOnDeletion) {
-  class RecordingVH : public CallbackVH {
+  class RecordingVH final : public CallbackVH {
   public:
     int DeletedCalls;
     int AURWCalls;
@@ -261,7 +261,7 @@ TEST_F(ValueHandle, CallbackVH_CallbackOnDeletion) {
 }
 
 TEST_F(ValueHandle, CallbackVH_CallbackOnRAUW) {
-  class RecordingVH : public CallbackVH {
+  class RecordingVH final : public CallbackVH {
   public:
     int DeletedCalls;
     Value *AURWArgument;
@@ -291,7 +291,7 @@ TEST_F(ValueHandle, CallbackVH_CallbackOnRAUW) {
 }
 
 TEST_F(ValueHandle, CallbackVH_DeletionCanRAUW) {
-  class RecoveringVH : public CallbackVH {
+  class RecoveringVH final : public CallbackVH {
   public:
     int DeletedCalls;
     Value *AURWArgument;
@@ -339,7 +339,7 @@ TEST_F(ValueHandle, DestroyingOtherVHOnSameValueDoesntBreakIteration) {
   // arrangement of other VHs so that the bad behavior would be
   // triggered in whichever order callbacks run.
 
-  class DestroyingVH : public CallbackVH {
+  class DestroyingVH final : public CallbackVH {
   public:
     std::unique_ptr<WeakVH> ToClear[2];
     DestroyingVH(Value *V) {
@@ -384,7 +384,7 @@ TEST_F(ValueHandle, AssertingVHCheckedLast) {
   // Value deletion, the CallbackVH should get a chance to do so
   // before the AssertingVHs assert.
 
-  class ClearingVH : public CallbackVH {
+  class ClearingVH final : public CallbackVH {
   public:
     AssertingVH<Value> *ToClear[2];
     ClearingVH(Value *V,