LLVM  9.0.0svn
TrackingMDRef.h
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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.
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 
36  if (&X == this)
37  return *this;
38 
39  untrack();
40  MD = X.MD;
41  retrack(X);
42  return *this;
43  }
44 
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)
86  }
87 
88  void untrack() {
89  if (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 {
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 
117  Ref = std::move(X.Ref);
118  return *this;
119  }
120 
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 
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 
155  return MD.get();
156  }
157 };
158 
159 template <class T> struct simplify_type<TypedTrackingMDRef<T>> {
160  using SimpleType = T *;
161 
163  return MD.get();
164  }
165 };
166 
167 template <class T> struct simplify_type<const TypedTrackingMDRef<T>> {
168  using SimpleType = T *;
169 
171  return MD.get();
172  }
173 };
174 
175 } // end namespace llvm
176 
177 #endif // LLVM_IR_TRACKINGMDREF_H
static SimpleType getSimplifiedValue(const TrackingMDRef &MD)
static GCMetadataPrinterRegistry::Add< ErlangGCPrinter > X("erlang", "erlang-compatible garbage collector")
TrackingMDRef & operator=(TrackingMDRef &&X)
Definition: TrackingMDRef.h:35
This class represents lattice values for constants.
Definition: AllocatorList.h:23
Tracking metadata reference.
Definition: TrackingMDRef.h:25
bool operator==(const TypedTrackingMDRef &X) const
Metadata & operator*() const
Definition: TrackingMDRef.h:60
TypedTrackingMDRef & operator=(const TypedTrackingMDRef &X)
This file contains the declarations for metadata subclasses.
Definition: BitVector.h:937
static bool track(Metadata *&MD)
Track the reference to metadata.
Definition: Metadata.h:220
The access may reference the value stored in memory.
TypedTrackingMDRef & operator=(TypedTrackingMDRef &&X)
TrackingMDRef()=default
TypedTrackingMDRef(const TypedTrackingMDRef &X)
TrackingMDRef(TrackingMDRef &&X)
Definition: TrackingMDRef.h:32
static SimpleType getSimplifiedValue(TypedTrackingMDRef< T > &MD)
Metadata * get() const
Definition: TrackingMDRef.h:57
TrackingMDRef(const TrackingMDRef &X)
Definition: TrackingMDRef.h:33
static SimpleType getSimplifiedValue(const TypedTrackingMDRef< T > &MD)
static bool retrack(Metadata *&MD, Metadata *&New)
Move tracking from one reference to another.
Definition: Metadata.h:256
Metadata * operator->() const
Definition: TrackingMDRef.h:59
Typed tracking ref.
bool operator!=(const TrackingMDRef &X) const
Definition: TrackingMDRef.h:80
bool operator!=(const TypedTrackingMDRef &X) const
TrackingMDRef & operator=(const TrackingMDRef &X)
Definition: TrackingMDRef.h:45
static void untrack(Metadata *&MD)
Stop tracking a reference to metadata.
Definition: Metadata.h:245
bool hasTrivialDestructor() const
Check whether this has a trivial destructor.
TrackingMDRef(Metadata *MD)
Definition: TrackingMDRef.h:30
bool hasTrivialDestructor() const
Check whether this has a trivial destructor.
Definition: TrackingMDRef.h:75
assert(ImpDefSCC.getReg()==AMDGPU::SCC &&ImpDefSCC.isDef())
static SimpleType getSimplifiedValue(TrackingMDRef &MD)
aarch64 promote const
void reset(Metadata *MD)
Definition: TrackingMDRef.h:66
bool operator==(const TrackingMDRef &X) const
Definition: TrackingMDRef.h:79
static bool isReplaceable(const Metadata &MD)
Check whether metadata is replaceable.
Definition: Metadata.cpp:193
Root of the metadata hierarchy.
Definition: Metadata.h:57
TypedTrackingMDRef(TypedTrackingMDRef &&X)