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 //===----------------------------------------------------------------------===//
19 #include "llvm/User.h"
20 #include "llvm/Type.h"
21 #include "llvm/OperandTraits.h"
22 #include "llvm/ADT/SmallVector.h"
23 #include "llvm/ADT/ilist_node.h"
24 #include "llvm/Support/ErrorHandling.h"
25 #include "llvm/Support/ValueHandle.h"
30 template<class ConstantClass, class TypeClass, class ValType>
31 struct ConstantCreator;
33 //===----------------------------------------------------------------------===//
34 // MetadataBase - A base class for MDNode, MDString and NamedMDNode.
35 class MetadataBase : public User {
37 /// ReservedSpace - The number of operands actually allocated. NumOperands is
38 /// the number actually in use.
39 unsigned ReservedSpace;
42 MetadataBase(const Type *Ty, unsigned scid)
43 : User(Ty, scid, NULL, 0), ReservedSpace(0) {}
45 void resizeOperands(unsigned NumOps);
47 /// isNullValue - Return true if this is the value that would be returned by
48 /// getNullValue. This always returns false because getNullValue will never
50 virtual bool isNullValue() const {
54 /// Methods for support type inquiry through isa, cast, and dyn_cast:
55 static inline bool classof(const MetadataBase *) { return true; }
56 static bool classof(const Value *V) {
57 return V->getValueID() == MDStringVal || V->getValueID() == MDNodeVal
58 || V->getValueID() == NamedMDNodeVal;
62 //===----------------------------------------------------------------------===//
63 /// MDString - a single uniqued string.
64 /// These are used to efficiently contain a byte sequence for metadata.
65 /// MDString is always unnamd.
66 class MDString : public MetadataBase {
67 MDString(const MDString &); // DO NOT IMPLEMENT
68 void *operator new(size_t, unsigned); // DO NOT IMPLEMENT
69 unsigned getNumOperands(); // DO NOT IMPLEMENT
73 explicit MDString(LLVMContext &C, const char *begin, unsigned l)
74 : MetadataBase(Type::getMetadataTy(C), Value::MDStringVal), Str(begin, l) {}
77 // Do not allocate any space for operands.
78 void *operator new(size_t s) {
79 return User::operator new(s, 0);
81 static MDString *get(LLVMContext &Context, const StringRef &Str);
83 StringRef getString() const { return Str; }
85 unsigned length() const { return Str.size(); }
87 /// begin() - Pointer to the first byte of the string.
89 const char *begin() const { return Str.begin(); }
91 /// end() - Pointer to one byte past the end of the string.
93 const char *end() const { return Str.end(); }
95 /// Methods for support type inquiry through isa, cast, and dyn_cast:
96 static inline bool classof(const MDString *) { return true; }
97 static bool classof(const Value *V) {
98 return V->getValueID() == MDStringVal;
102 //===----------------------------------------------------------------------===//
103 /// MDNode - a tuple of other values.
104 /// These contain a list of the values that represent the metadata.
105 /// MDNode is always unnamed.
106 class MDNode : public MetadataBase {
107 MDNode(const MDNode &); // DO NOT IMPLEMENT
108 void *operator new(size_t, unsigned); // DO NOT IMPLEMENT
109 // getNumOperands - Make this only available for private uses.
110 unsigned getNumOperands() { return User::getNumOperands(); }
112 SmallVector<WeakVH, 4> Node;
114 friend struct ConstantCreator<MDNode, Type, std::vector<Value*> >;
116 explicit MDNode(LLVMContext &C, Value*const* Vals, unsigned NumVals);
118 // Do not allocate any space for operands.
119 void *operator new(size_t s) {
120 return User::operator new(s, 0);
122 // Constructors and destructors.
123 static MDNode *get(LLVMContext &Context,
124 Value* const* Vals, unsigned NumVals);
126 /// dropAllReferences - Remove all uses and clear node vector.
127 void dropAllReferences();
129 /// ~MDNode - Destroy MDNode.
132 /// getElement - Return specified element.
133 Value *getElement(unsigned i) const {
134 assert (getNumElements() > i && "Invalid element number!");
138 /// getNumElements - Return number of MDNode elements.
139 unsigned getNumElements() const {
144 typedef SmallVectorImpl<WeakVH>::const_iterator const_elem_iterator;
145 typedef SmallVectorImpl<WeakVH>::iterator elem_iterator;
146 /// elem_empty - Return true if MDNode is empty.
147 bool elem_empty() const { return Node.empty(); }
148 const_elem_iterator elem_begin() const { return Node.begin(); }
149 const_elem_iterator elem_end() const { return Node.end(); }
150 elem_iterator elem_begin() { return Node.begin(); }
151 elem_iterator elem_end() { return Node.end(); }
153 /// isNullValue - Return true if this is the value that would be returned by
154 /// getNullValue. This always returns false because getNullValue will never
155 /// produce metadata.
156 virtual bool isNullValue() const {
160 virtual void replaceUsesOfWithOnConstant(Value *From, Value *To, Use *U) {
161 llvm_unreachable("This should never be called because MDNodes have no ops");
164 /// Methods for support type inquiry through isa, cast, and dyn_cast:
165 static inline bool classof(const MDNode *) { return true; }
166 static bool classof(const Value *V) {
167 return V->getValueID() == MDNodeVal;
171 //===----------------------------------------------------------------------===//
172 /// WeakMetadataVH - a weak value handle for metadata.
173 class WeakMetadataVH : public WeakVH {
175 WeakMetadataVH() : WeakVH() {}
176 WeakMetadataVH(MetadataBase *M) : WeakVH(M) {}
177 WeakMetadataVH(const WeakMetadataVH &RHS) : WeakVH(RHS) {}
179 operator Value*() const {
180 llvm_unreachable("WeakMetadataVH only handles Metadata");
183 operator MetadataBase*() const {
184 return dyn_cast_or_null<MetadataBase>(getValPtr());
188 //===----------------------------------------------------------------------===//
189 /// NamedMDNode - a tuple of other metadata.
190 /// NamedMDNode is always named. All NamedMDNode element has a type of metadata.
191 template<typename ValueSubClass, typename ItemParentClass>
192 class SymbolTableListTraits;
194 class NamedMDNode : public MetadataBase, public ilist_node<NamedMDNode> {
195 friend class SymbolTableListTraits<NamedMDNode, Module>;
196 friend class LLVMContextImpl;
198 NamedMDNode(const NamedMDNode &); // DO NOT IMPLEMENT
199 void *operator new(size_t, unsigned); // DO NOT IMPLEMENT
200 // getNumOperands - Make this only available for private uses.
201 unsigned getNumOperands() { return User::getNumOperands(); }
204 SmallVector<WeakMetadataVH, 4> Node;
205 typedef SmallVectorImpl<WeakMetadataVH>::iterator elem_iterator;
208 explicit NamedMDNode(LLVMContext &C, const Twine &N, MetadataBase*const* Vals,
209 unsigned NumVals, Module *M = 0);
211 // Do not allocate any space for operands.
212 void *operator new(size_t s) {
213 return User::operator new(s, 0);
215 static NamedMDNode *Create(LLVMContext &C, const Twine &N,
216 MetadataBase*const*MDs,
217 unsigned NumMDs, Module *M = 0) {
218 return new NamedMDNode(C, N, MDs, NumMDs, M);
221 static NamedMDNode *Create(const NamedMDNode *NMD, Module *M = 0);
223 /// eraseFromParent - Drop all references and remove the node from parent
225 void eraseFromParent();
227 /// dropAllReferences - Remove all uses and clear node vector.
228 void dropAllReferences();
230 /// ~NamedMDNode - Destroy NamedMDNode.
233 /// getParent - Get the module that holds this named metadata collection.
234 inline Module *getParent() { return Parent; }
235 inline const Module *getParent() const { return Parent; }
236 void setParent(Module *M) { Parent = M; }
238 /// getElement - Return specified element.
239 MetadataBase *getElement(unsigned i) const {
240 assert (getNumElements() > i && "Invalid element number!");
244 /// getNumElements - Return number of NamedMDNode elements.
245 unsigned getNumElements() const {
249 /// addElement - Add metadata element.
250 void addElement(MetadataBase *M) {
252 OperandList[NumOperands++] = M;
253 Node.push_back(WeakMetadataVH(M));
256 typedef SmallVectorImpl<WeakMetadataVH>::const_iterator const_elem_iterator;
257 bool elem_empty() const { return Node.empty(); }
258 const_elem_iterator elem_begin() const { return Node.begin(); }
259 const_elem_iterator elem_end() const { return Node.end(); }
260 elem_iterator elem_begin() { return Node.begin(); }
261 elem_iterator elem_end() { return Node.end(); }
263 /// isNullValue - Return true if this is the value that would be returned by
264 /// getNullValue. This always returns false because getNullValue will never
265 /// produce metadata.
266 virtual bool isNullValue() const {
270 virtual void replaceUsesOfWithOnConstant(Value *From, Value *To, Use *U) {
272 "This should never be called because NamedMDNodes have no ops");
275 /// Methods for support type inquiry through isa, cast, and dyn_cast:
276 static inline bool classof(const NamedMDNode *) { return true; }
277 static bool classof(const Value *V) {
278 return V->getValueID() == NamedMDNodeVal;
282 } // end llvm namespace