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| Rev | Author | Line No. | Line | 
|---|---|---|---|
| 14 | pmbaty | 1 | //===- llvm/IR/TrackingMDRef.h - Tracking Metadata references ---*- C++ -*-===// | 
| 2 | // | ||
| 3 | // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. | ||
| 4 | // See https://llvm.org/LICENSE.txt for license information. | ||
| 5 | // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception | ||
| 6 | // | ||
| 7 | //===----------------------------------------------------------------------===// | ||
| 8 | // | ||
| 9 | // References to metadata that track RAUW. | ||
| 10 | // | ||
| 11 | //===----------------------------------------------------------------------===// | ||
| 12 | |||
| 13 | #ifndef LLVM_IR_TRACKINGMDREF_H | ||
| 14 | #define LLVM_IR_TRACKINGMDREF_H | ||
| 15 | |||
| 16 | #include "llvm/IR/Metadata.h" | ||
| 17 | #include <algorithm> | ||
| 18 | #include <cassert> | ||
| 19 | |||
| 20 | namespace llvm { | ||
| 21 | |||
| 22 | /// Tracking metadata reference. | ||
| 23 | /// | ||
| 24 | /// This class behaves like \a TrackingVH, but for metadata. | ||
| 25 | class TrackingMDRef { | ||
| 26 | Metadata *MD = nullptr; | ||
| 27 | |||
| 28 | public: | ||
| 29 | TrackingMDRef() = default; | ||
| 30 | explicit TrackingMDRef(Metadata *MD) : MD(MD) { track(); } | ||
| 31 | |||
| 32 | TrackingMDRef(TrackingMDRef &&X) : MD(X.MD) { retrack(X); } | ||
| 33 | TrackingMDRef(const TrackingMDRef &X) : MD(X.MD) { track(); } | ||
| 34 | |||
| 35 | TrackingMDRef &operator=(TrackingMDRef &&X) { | ||
| 36 | if (&X == this) | ||
| 37 | return *this; | ||
| 38 | |||
| 39 | untrack(); | ||
| 40 | MD = X.MD; | ||
| 41 | retrack(X); | ||
| 42 | return *this; | ||
| 43 |   } | ||
| 44 | |||
| 45 | TrackingMDRef &operator=(const TrackingMDRef &X) { | ||
| 46 | if (&X == this) | ||
| 47 | return *this; | ||
| 48 | |||
| 49 | untrack(); | ||
| 50 | MD = X.MD; | ||
| 51 | track(); | ||
| 52 | return *this; | ||
| 53 |   } | ||
| 54 | |||
| 55 | ~TrackingMDRef() { untrack(); } | ||
| 56 | |||
| 57 | Metadata *get() const { return MD; } | ||
| 58 | operator Metadata *() const { return get(); } | ||
| 59 | Metadata *operator->() const { return get(); } | ||
| 60 | Metadata &operator*() const { return *get(); } | ||
| 61 | |||
| 62 | void reset() { | ||
| 63 | untrack(); | ||
| 64 | MD = nullptr; | ||
| 65 |   } | ||
| 66 | void reset(Metadata *MD) { | ||
| 67 | untrack(); | ||
| 68 | this->MD = MD; | ||
| 69 | track(); | ||
| 70 |   } | ||
| 71 | |||
| 72 |   /// Check whether this has a trivial destructor. | ||
| 73 |   /// | ||
| 74 |   /// If \c MD isn't replaceable, the destructor will be a no-op. | ||
| 75 | bool hasTrivialDestructor() const { | ||
| 76 | return !MD || !MetadataTracking::isReplaceable(*MD); | ||
| 77 |   } | ||
| 78 | |||
| 79 | bool operator==(const TrackingMDRef &X) const { return MD == X.MD; } | ||
| 80 | bool operator!=(const TrackingMDRef &X) const { return MD != X.MD; } | ||
| 81 | |||
| 82 | private: | ||
| 83 | void track() { | ||
| 84 | if (MD) | ||
| 85 | MetadataTracking::track(MD); | ||
| 86 |   } | ||
| 87 | |||
| 88 | void untrack() { | ||
| 89 | if (MD) | ||
| 90 | MetadataTracking::untrack(MD); | ||
| 91 |   } | ||
| 92 | |||
| 93 | void retrack(TrackingMDRef &X) { | ||
| 94 | assert(MD == X.MD && "Expected values to match"); | ||
| 95 | if (X.MD) { | ||
| 96 | MetadataTracking::retrack(X.MD, MD); | ||
| 97 | X.MD = nullptr; | ||
| 98 |     } | ||
| 99 |   } | ||
| 100 | }; | ||
| 101 | |||
| 102 | /// Typed tracking ref. | ||
| 103 | /// | ||
| 104 | /// Track refererences of a particular type.  It's useful to use this for \a | ||
| 105 | /// MDNode and \a ValueAsMetadata. | ||
| 106 | template <class T> class TypedTrackingMDRef { | ||
| 107 |   TrackingMDRef Ref; | ||
| 108 | |||
| 109 | public: | ||
| 110 | TypedTrackingMDRef() = default; | ||
| 111 | explicit TypedTrackingMDRef(T *MD) : Ref(static_cast<Metadata *>(MD)) {} | ||
| 112 | |||
| 113 | TypedTrackingMDRef(TypedTrackingMDRef &&X) : Ref(std::move(X.Ref)) {} | ||
| 114 | TypedTrackingMDRef(const TypedTrackingMDRef &X) : Ref(X.Ref) {} | ||
| 115 | |||
| 116 | TypedTrackingMDRef &operator=(TypedTrackingMDRef &&X) { | ||
| 117 | Ref = std::move(X.Ref); | ||
| 118 | return *this; | ||
| 119 |   } | ||
| 120 | |||
| 121 | TypedTrackingMDRef &operator=(const TypedTrackingMDRef &X) { | ||
| 122 | Ref = X.Ref; | ||
| 123 | return *this; | ||
| 124 |   } | ||
| 125 | |||
| 126 | T *get() const { return (T *)Ref.get(); } | ||
| 127 | operator T *() const { return get(); } | ||
| 128 | T *operator->() const { return get(); } | ||
| 129 | T &operator*() const { return *get(); } | ||
| 130 | |||
| 131 | bool operator==(const TypedTrackingMDRef &X) const { return Ref == X.Ref; } | ||
| 132 | bool operator!=(const TypedTrackingMDRef &X) const { return Ref != X.Ref; } | ||
| 133 | |||
| 134 | void reset() { Ref.reset(); } | ||
| 135 | void reset(T *MD) { Ref.reset(static_cast<Metadata *>(MD)); } | ||
| 136 | |||
| 137 |   /// Check whether this has a trivial destructor. | ||
| 138 | bool hasTrivialDestructor() const { return Ref.hasTrivialDestructor(); } | ||
| 139 | }; | ||
| 140 | |||
| 141 | using TrackingMDNodeRef = TypedTrackingMDRef<MDNode>; | ||
| 142 | using TrackingValueAsMetadataRef = TypedTrackingMDRef<ValueAsMetadata>; | ||
| 143 | |||
| 144 | // Expose the underlying metadata to casting. | ||
| 145 | template <> struct simplify_type<TrackingMDRef> { | ||
| 146 | using SimpleType = Metadata *; | ||
| 147 | |||
| 148 | static SimpleType getSimplifiedValue(TrackingMDRef &MD) { return MD.get(); } | ||
| 149 | }; | ||
| 150 | |||
| 151 | template <> struct simplify_type<const TrackingMDRef> { | ||
| 152 | using SimpleType = Metadata *; | ||
| 153 | |||
| 154 | static SimpleType getSimplifiedValue(const TrackingMDRef &MD) { | ||
| 155 | return MD.get(); | ||
| 156 |   } | ||
| 157 | }; | ||
| 158 | |||
| 159 | template <class T> struct simplify_type<TypedTrackingMDRef<T>> { | ||
| 160 | using SimpleType = T *; | ||
| 161 | |||
| 162 | static SimpleType getSimplifiedValue(TypedTrackingMDRef<T> &MD) { | ||
| 163 | return MD.get(); | ||
| 164 |   } | ||
| 165 | }; | ||
| 166 | |||
| 167 | template <class T> struct simplify_type<const TypedTrackingMDRef<T>> { | ||
| 168 | using SimpleType = T *; | ||
| 169 | |||
| 170 | static SimpleType getSimplifiedValue(const TypedTrackingMDRef<T> &MD) { | ||
| 171 | return MD.get(); | ||
| 172 |   } | ||
| 173 | }; | ||
| 174 | |||
| 175 | } // end namespace llvm | ||
| 176 | |||
| 177 | #endif // LLVM_IR_TRACKINGMDREF_H |