1 //===- llvm/IR/TrackingMDRef.h - Tracking Metadata references ---*- C++ -*-===//
3 // The LLVM Compiler Infrastructure
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
8 //===----------------------------------------------------------------------===//
10 // References to metadata that track RAUW.
12 //===----------------------------------------------------------------------===//
14 #ifndef LLVM_IR_TRACKINGMDREF_H
15 #define LLVM_IR_TRACKINGMDREF_H
17 #include "llvm/IR/Metadata.h"
23 /// Tracking metadata reference.
25 /// This class behaves like \a TrackingVH, but for metadata.
27 Metadata *MD = nullptr;
30 TrackingMDRef() = default;
31 explicit TrackingMDRef(Metadata *MD) : MD(MD) { track(); }
33 TrackingMDRef(TrackingMDRef &&X) : MD(X.MD) { retrack(X); }
34 TrackingMDRef(const TrackingMDRef &X) : MD(X.MD) { track(); }
36 TrackingMDRef &operator=(TrackingMDRef &&X) {
46 TrackingMDRef &operator=(const TrackingMDRef &X) {
56 ~TrackingMDRef() { untrack(); }
58 Metadata *get() const { return MD; }
59 operator Metadata *() const { return get(); }
60 Metadata *operator->() const { return get(); }
61 Metadata &operator*() const { return *get(); }
67 void reset(Metadata *MD) {
73 /// Check whether this has a trivial destructor.
75 /// If \c MD isn't replaceable, the destructor will be a no-op.
76 bool hasTrivialDestructor() const {
77 return !MD || !MetadataTracking::isReplaceable(*MD);
80 bool operator==(const TrackingMDRef &X) const { return MD == X.MD; }
81 bool operator!=(const TrackingMDRef &X) const { return MD != X.MD; }
86 MetadataTracking::track(MD);
91 MetadataTracking::untrack(MD);
94 void retrack(TrackingMDRef &X) {
95 assert(MD == X.MD && "Expected values to match");
97 MetadataTracking::retrack(X.MD, MD);
103 /// Typed tracking ref.
105 /// Track refererences of a particular type. It's useful to use this for \a
106 /// MDNode and \a ValueAsMetadata.
107 template <class T> class TypedTrackingMDRef {
111 TypedTrackingMDRef() = default;
112 explicit TypedTrackingMDRef(T *MD) : Ref(static_cast<Metadata *>(MD)) {}
114 TypedTrackingMDRef(TypedTrackingMDRef &&X) : Ref(std::move(X.Ref)) {}
115 TypedTrackingMDRef(const TypedTrackingMDRef &X) : Ref(X.Ref) {}
117 TypedTrackingMDRef &operator=(TypedTrackingMDRef &&X) {
118 Ref = std::move(X.Ref);
122 TypedTrackingMDRef &operator=(const TypedTrackingMDRef &X) {
127 T *get() const { return (T *)Ref.get(); }
128 operator T *() const { return get(); }
129 T *operator->() const { return get(); }
130 T &operator*() const { return *get(); }
132 bool operator==(const TypedTrackingMDRef &X) const { return Ref == X.Ref; }
133 bool operator!=(const TypedTrackingMDRef &X) const { return Ref != X.Ref; }
135 void reset() { Ref.reset(); }
136 void reset(T *MD) { Ref.reset(static_cast<Metadata *>(MD)); }
138 /// Check whether this has a trivial destructor.
139 bool hasTrivialDestructor() const { return Ref.hasTrivialDestructor(); }
142 using TrackingMDNodeRef = TypedTrackingMDRef<MDNode>;
143 using TrackingValueAsMetadataRef = TypedTrackingMDRef<ValueAsMetadata>;
145 // Expose the underlying metadata to casting.
146 template <> struct simplify_type<TrackingMDRef> {
147 using SimpleType = Metadata *;
149 static SimpleType getSimplifiedValue(TrackingMDRef &MD) { return MD.get(); }
152 template <> struct simplify_type<const TrackingMDRef> {
153 using SimpleType = Metadata *;
155 static SimpleType getSimplifiedValue(const TrackingMDRef &MD) {
160 template <class T> struct simplify_type<TypedTrackingMDRef<T>> {
161 using SimpleType = T *;
163 static SimpleType getSimplifiedValue(TypedTrackingMDRef<T> &MD) {
168 template <class T> struct simplify_type<const TypedTrackingMDRef<T>> {
169 using SimpleType = T *;
171 static SimpleType getSimplifiedValue(const TypedTrackingMDRef<T> &MD) {
176 } // end namespace llvm
178 #endif // LLVM_IR_TRACKINGMDREF_H