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"
21 /// \brief Tracking metadata reference.
23 /// This class behaves like \a TrackingVH, but for metadata.
28 TrackingMDRef() : MD(nullptr) {}
29 explicit TrackingMDRef(Metadata *MD) : MD(MD) { track(); }
31 TrackingMDRef(TrackingMDRef &&X) : MD(X.MD) { retrack(X); }
32 TrackingMDRef(const TrackingMDRef &X) : MD(X.MD) { track(); }
33 TrackingMDRef &operator=(TrackingMDRef &&X) {
42 TrackingMDRef &operator=(const TrackingMDRef &X) {
51 ~TrackingMDRef() { untrack(); }
53 Metadata *get() const { return MD; }
54 operator Metadata *() const { return get(); }
55 Metadata *operator->() const { return get(); }
56 Metadata &operator*() const { return *get(); }
62 void reset(Metadata *MD) {
68 /// \brief Check whether this has a trivial destructor.
70 /// If \c MD isn't replaceable, the destructor will be a no-op.
71 bool hasTrivialDestructor() const {
72 return !MD || !MetadataTracking::isReplaceable(*MD);
75 bool operator==(const TrackingMDRef &X) const { return MD == X.MD; }
76 bool operator!=(const TrackingMDRef &X) const { return MD != X.MD; }
81 MetadataTracking::track(MD);
85 MetadataTracking::untrack(MD);
87 void retrack(TrackingMDRef &X) {
88 assert(MD == X.MD && "Expected values to match");
90 MetadataTracking::retrack(X.MD, MD);
96 /// \brief Typed tracking ref.
98 /// Track refererences of a particular type. It's useful to use this for \a
99 /// MDNode and \a ValueAsMetadata.
100 template <class T> class TypedTrackingMDRef {
104 TypedTrackingMDRef() {}
105 explicit TypedTrackingMDRef(T *MD) : Ref(static_cast<Metadata *>(MD)) {}
107 TypedTrackingMDRef(TypedTrackingMDRef &&X) : Ref(std::move(X.Ref)) {}
108 TypedTrackingMDRef(const TypedTrackingMDRef &X) : Ref(X.Ref) {}
109 TypedTrackingMDRef &operator=(TypedTrackingMDRef &&X) {
110 Ref = std::move(X.Ref);
113 TypedTrackingMDRef &operator=(const TypedTrackingMDRef &X) {
118 T *get() const { return (T *)Ref.get(); }
119 operator T *() const { return get(); }
120 T *operator->() const { return get(); }
121 T &operator*() const { return *get(); }
123 bool operator==(const TypedTrackingMDRef &X) const { return Ref == X.Ref; }
124 bool operator!=(const TypedTrackingMDRef &X) const { return Ref != X.Ref; }
126 void reset() { Ref.reset(); }
127 void reset(T *MD) { Ref.reset(static_cast<Metadata *>(MD)); }
129 /// \brief Check whether this has a trivial destructor.
130 bool hasTrivialDestructor() const { return Ref.hasTrivialDestructor(); }
133 typedef TypedTrackingMDRef<MDNode> TrackingMDNodeRef;
134 typedef TypedTrackingMDRef<ValueAsMetadata> TrackingValueAsMetadataRef;
136 // Expose the underlying metadata to casting.
137 template <> struct simplify_type<TrackingMDRef> {
138 typedef Metadata *SimpleType;
139 static SimpleType getSimplifiedValue(TrackingMDRef &MD) { return MD.get(); }
142 template <> struct simplify_type<const TrackingMDRef> {
143 typedef Metadata *SimpleType;
144 static SimpleType getSimplifiedValue(const TrackingMDRef &MD) {
149 template <class T> struct simplify_type<TypedTrackingMDRef<T>> {
150 typedef T *SimpleType;
151 static SimpleType getSimplifiedValue(TypedTrackingMDRef<T> &MD) {
156 template <class T> struct simplify_type<const TypedTrackingMDRef<T>> {
157 typedef T *SimpleType;
158 static SimpleType getSimplifiedValue(const TypedTrackingMDRef<T> &MD) {
163 } // end namespace llvm