1 //===-- llvm/Metadata.h - Metadata definitions ------------------*- 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 //===----------------------------------------------------------------------===//
11 /// This file contains the declarations for metadata subclasses.
12 /// They represent the different flavors of metadata that live in LLVM.
14 //===----------------------------------------------------------------------===//
16 #ifndef LLVM_METADATA_H
17 #define LLVM_METADATA_H
19 #include "llvm/Value.h"
20 #include "llvm/ADT/FoldingSet.h"
21 #include "llvm/ADT/ilist_node.h"
28 template <typename T> class SmallVectorImpl;
30 //===----------------------------------------------------------------------===//
31 // MetadataBase - A base class for MDNode, MDString and NamedMDNode.
32 class MetadataBase : public Value {
34 MetadataBase(const Type *Ty, unsigned scid)
39 /// Methods for support type inquiry through isa, cast, and dyn_cast:
40 static inline bool classof(const MetadataBase *) { return true; }
41 static bool classof(const Value *V) {
42 return V->getValueID() == MDStringVal || V->getValueID() == MDNodeVal
43 || V->getValueID() == NamedMDNodeVal;
47 //===----------------------------------------------------------------------===//
48 /// MDString - a single uniqued string.
49 /// These are used to efficiently contain a byte sequence for metadata.
50 /// MDString is always unnamd.
51 class MDString : public MetadataBase {
52 MDString(const MDString &); // DO NOT IMPLEMENT
56 explicit MDString(LLVMContext &C, StringRef S);
59 static MDString *get(LLVMContext &Context, StringRef Str);
60 static MDString *get(LLVMContext &Context, const char *Str);
62 StringRef getString() const { return Str; }
64 unsigned getLength() const { return (unsigned)Str.size(); }
66 typedef StringRef::iterator iterator;
68 /// begin() - Pointer to the first byte of the string.
70 iterator begin() const { return Str.begin(); }
72 /// end() - Pointer to one byte past the end of the string.
74 iterator end() const { return Str.end(); }
76 /// Methods for support type inquiry through isa, cast, and dyn_cast:
77 static inline bool classof(const MDString *) { return true; }
78 static bool classof(const Value *V) {
79 return V->getValueID() == MDStringVal;
86 //===----------------------------------------------------------------------===//
87 /// MDNode - a tuple of other values.
88 class MDNode : public MetadataBase, public FoldingSetNode {
89 MDNode(const MDNode &); // DO NOT IMPLEMENT
90 void operator=(const MDNode &); // DO NOT IMPLEMENT
91 friend class MDNodeElement;
93 /// NumOperands - This many 'MDNodeElement' items are co-allocated onto the
94 /// end of this MDNode.
97 // Subclass data enums.
99 /// FunctionLocalBit - This bit is set if this MDNode is function local.
100 /// This is true when it (potentially transitively) contains a reference to
101 /// something in a function, like an argument, basicblock, or instruction.
102 FunctionLocalBit = 1 << 0,
104 /// NotUniquedBit - This is set on MDNodes that are not uniqued because they
105 /// have a null perand.
106 NotUniquedBit = 1 << 1,
108 /// DestroyFlag - This bit is set by destroy() so the destructor can assert
109 /// that the node isn't being destroyed with a plain 'delete'.
113 // Replace each instance of F from the element list of this node with T.
114 void replaceElement(MDNodeElement *Op, Value *NewVal);
118 explicit MDNode(LLVMContext &C, Value *const *Vals, unsigned NumVals,
119 bool isFunctionLocal);
121 // Constructors and destructors.
122 static MDNode *get(LLVMContext &Context, Value *const *Vals, unsigned NumVals,
123 bool isFunctionLocal = false);
125 /// getElement - Return specified element.
126 Value *getElement(unsigned i) const;
128 /// getNumElements - Return number of MDNode elements.
129 unsigned getNumElements() const { return NumOperands; }
131 /// isFunctionLocal - Return whether MDNode is local to a function.
132 /// Note: MDNodes are designated as function-local when created, and keep
133 /// that designation even if their operands are modified to no longer
134 /// refer to function-local IR.
135 bool isFunctionLocal() const {
136 return (getSubclassDataFromValue() & FunctionLocalBit) != 0;
139 // destroy - Delete this node. Only when there are no uses.
142 /// Profile - calculate a unique identifier for this MDNode to collapse
144 void Profile(FoldingSetNodeID &ID) const;
146 /// Methods for support type inquiry through isa, cast, and dyn_cast:
147 static inline bool classof(const MDNode *) { return true; }
148 static bool classof(const Value *V) {
149 return V->getValueID() == MDNodeVal;
152 bool isNotUniqued() const {
153 return (getSubclassDataFromValue() & NotUniquedBit) != 0;
155 void setIsNotUniqued() {
156 setValueSubclassData(getSubclassDataFromValue() | NotUniquedBit);
159 // Shadow Value::setValueSubclassData with a private forwarding method so that
160 // any future subclasses cannot accidentally use it.
161 void setValueSubclassData(unsigned short D) {
162 Value::setValueSubclassData(D);
166 //===----------------------------------------------------------------------===//
167 /// NamedMDNode - a tuple of other metadata.
168 /// NamedMDNode is always named. All NamedMDNode element has a type of metadata.
169 template<typename ValueSubClass, typename ItemParentClass>
170 class SymbolTableListTraits;
172 class NamedMDNode : public MetadataBase, public ilist_node<NamedMDNode> {
173 friend class SymbolTableListTraits<NamedMDNode, Module>;
174 friend class LLVMContextImpl;
176 NamedMDNode(const NamedMDNode &); // DO NOT IMPLEMENT
179 void *Operands; // SmallVector<TrackingVH<MetadataBase>, 4>
181 void setParent(Module *M) { Parent = M; }
183 explicit NamedMDNode(LLVMContext &C, const Twine &N, MetadataBase*const *Vals,
184 unsigned NumVals, Module *M = 0);
186 static NamedMDNode *Create(LLVMContext &C, const Twine &N,
187 MetadataBase *const *MDs,
188 unsigned NumMDs, Module *M = 0) {
189 return new NamedMDNode(C, N, MDs, NumMDs, M);
192 static NamedMDNode *Create(const NamedMDNode *NMD, Module *M = 0);
194 /// eraseFromParent - Drop all references and remove the node from parent
196 void eraseFromParent();
198 /// dropAllReferences - Remove all uses and clear node vector.
199 void dropAllReferences();
201 /// ~NamedMDNode - Destroy NamedMDNode.
204 /// getParent - Get the module that holds this named metadata collection.
205 inline Module *getParent() { return Parent; }
206 inline const Module *getParent() const { return Parent; }
208 /// getElement - Return specified element.
209 MetadataBase *getElement(unsigned i) const;
211 /// getNumElements - Return number of NamedMDNode elements.
212 unsigned getNumElements() const;
214 /// addElement - Add metadata element.
215 void addElement(MetadataBase *M);
217 /// Methods for support type inquiry through isa, cast, and dyn_cast:
218 static inline bool classof(const NamedMDNode *) { return true; }
219 static bool classof(const Value *V) {
220 return V->getValueID() == NamedMDNodeVal;
224 } // end llvm namespace