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"
18 #include "llvm/Support/Casting.h"
22 /// \brief Tracking metadata reference.
24 /// This class behaves like \a TrackingVH, but for metadata.
29 TrackingMDRef() : MD(nullptr) {}
30 explicit TrackingMDRef(Metadata *MD) : MD(MD) { track(); }
32 TrackingMDRef(TrackingMDRef &&X) : MD(X.MD) { retrack(X); }
33 TrackingMDRef(const TrackingMDRef &X) : MD(X.MD) { track(); }
34 TrackingMDRef &operator=(TrackingMDRef &&X) {
43 TrackingMDRef &operator=(const TrackingMDRef &X) {
52 ~TrackingMDRef() { untrack(); }
54 Metadata *get() const { return MD; }
55 operator Metadata *() const { return get(); }
56 Metadata *operator->() const { return get(); }
57 Metadata &operator*() const { return *get(); }
63 void reset(Metadata *MD) {
69 /// \brief Check whether this has a trivial destructor.
71 /// If \c MD isn't replaceable, the destructor will be a no-op.
72 bool hasTrivialDestructor() const {
73 return !MD || !MetadataTracking::isReplaceable(*MD);
76 bool operator==(const TrackingMDRef &X) const { return MD == X.MD; }
77 bool operator!=(const TrackingMDRef &X) const { return MD != X.MD; }
82 MetadataTracking::track(MD);
86 MetadataTracking::untrack(MD);
88 void retrack(TrackingMDRef &X) {
89 assert(MD == X.MD && "Expected values to match");
91 MetadataTracking::retrack(X.MD, MD);
97 /// \brief Typed tracking ref.
99 /// Track refererences of a particular type. It's useful to use this for \a
100 /// MDNode and \a ValueAsMetadata.
101 template <class T> class TypedTrackingMDRef {
105 TypedTrackingMDRef() {}
106 explicit TypedTrackingMDRef(T *MD) : Ref(static_cast<Metadata *>(MD)) {}
108 TypedTrackingMDRef(TypedTrackingMDRef &&X) : Ref(std::move(X.Ref)) {}
109 TypedTrackingMDRef(const TypedTrackingMDRef &X) : Ref(X.Ref) {}
110 TypedTrackingMDRef &operator=(TypedTrackingMDRef &&X) {
111 Ref = std::move(X.Ref);
114 TypedTrackingMDRef &operator=(const TypedTrackingMDRef &X) {
119 T *get() const { return (T *)Ref.get(); }
120 operator T *() const { return get(); }
121 T *operator->() const { return get(); }
122 T &operator*() const { return *get(); }
124 bool operator==(const TypedTrackingMDRef &X) const { return Ref == X.Ref; }
125 bool operator!=(const TypedTrackingMDRef &X) const { return Ref != X.Ref; }
127 void reset() { Ref.reset(); }
128 void reset(T *MD) { Ref.reset(static_cast<Metadata *>(MD)); }
130 /// \brief Check whether this has a trivial destructor.
131 bool hasTrivialDestructor() const { return Ref.hasTrivialDestructor(); }
134 typedef TypedTrackingMDRef<MDNode> TrackingMDNodeRef;
135 typedef TypedTrackingMDRef<ValueAsMetadata> TrackingValueAsMetadataRef;
137 // Expose the underlying metadata to casting.
138 template <> struct simplify_type<TrackingMDRef> {
139 typedef Metadata *SimpleType;
140 static SimpleType getSimplifiedValue(TrackingMDRef &MD) { return MD.get(); }
143 template <> struct simplify_type<const TrackingMDRef> {
144 typedef Metadata *SimpleType;
145 static SimpleType getSimplifiedValue(const TrackingMDRef &MD) {
150 template <class T> struct simplify_type<TypedTrackingMDRef<T>> {
151 typedef T *SimpleType;
152 static SimpleType getSimplifiedValue(TypedTrackingMDRef<T> &MD) {
157 template <class T> struct simplify_type<const TypedTrackingMDRef<T>> {
158 typedef T *SimpleType;
159 static SimpleType getSimplifiedValue(const TypedTrackingMDRef<T> &MD) {
164 } // end namespace llvm