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/ArrayRef.h"
21 #include "llvm/ADT/FoldingSet.h"
22 #include "llvm/ADT/ilist_node.h"
29 template <typename T> class SmallVectorImpl;
30 template<typename ValueSubClass, typename ItemParentClass>
31 class SymbolTableListTraits;
34 //===----------------------------------------------------------------------===//
35 /// MDString - a single uniqued string.
36 /// These are used to efficiently contain a byte sequence for metadata.
37 /// MDString is always unnamed.
38 class MDString : public Value {
39 MDString(const MDString &); // DO NOT IMPLEMENT
42 explicit MDString(LLVMContext &C, StringRef S);
45 static MDString *get(LLVMContext &Context, StringRef Str);
46 static MDString *get(LLVMContext &Context, const char *Str) {
47 return get(Context, Str ? StringRef(Str) : StringRef());
50 StringRef getString() const { return Str; }
52 unsigned getLength() const { return (unsigned)Str.size(); }
54 typedef StringRef::iterator iterator;
56 /// begin() - Pointer to the first byte of the string.
58 iterator begin() const { return Str.begin(); }
60 /// end() - Pointer to one byte past the end of the string.
62 iterator end() const { return Str.end(); }
64 /// Methods for support type inquiry through isa, cast, and dyn_cast:
65 static inline bool classof(const MDString *) { return true; }
66 static bool classof(const Value *V) {
67 return V->getValueID() == MDStringVal;
74 //===----------------------------------------------------------------------===//
75 /// MDNode - a tuple of other values.
76 class MDNode : public Value, public FoldingSetNode {
77 MDNode(const MDNode &); // DO NOT IMPLEMENT
78 void operator=(const MDNode &); // DO NOT IMPLEMENT
79 friend class MDNodeOperand;
80 friend class LLVMContextImpl;
82 /// NumOperands - This many 'MDNodeOperand' items are co-allocated onto the
83 /// end of this MDNode.
86 // Subclass data enums.
88 /// FunctionLocalBit - This bit is set if this MDNode is function local.
89 /// This is true when it (potentially transitively) contains a reference to
90 /// something in a function, like an argument, basicblock, or instruction.
91 FunctionLocalBit = 1 << 0,
93 /// NotUniquedBit - This is set on MDNodes that are not uniqued because they
94 /// have a null operand.
95 NotUniquedBit = 1 << 1,
97 /// DestroyFlag - This bit is set by destroy() so the destructor can assert
98 /// that the node isn't being destroyed with a plain 'delete'.
102 // FunctionLocal enums.
103 enum FunctionLocalness {
109 /// replaceOperand - Replace each instance of F from the operand list of this
111 void replaceOperand(MDNodeOperand *Op, Value *NewVal);
114 MDNode(LLVMContext &C, ArrayRef<Value*> Vals, bool isFunctionLocal);
116 static MDNode *getMDNode(LLVMContext &C, ArrayRef<Value*> Vals,
117 FunctionLocalness FL, bool Insert = true);
119 // Constructors and destructors.
120 static MDNode *get(LLVMContext &Context, ArrayRef<Value*> Vals);
121 // getWhenValsUnresolved - Construct MDNode determining function-localness
122 // from isFunctionLocal argument, not by analyzing Vals.
123 static MDNode *getWhenValsUnresolved(LLVMContext &Context,
124 ArrayRef<Value*> Vals,
125 bool isFunctionLocal);
127 static MDNode *getIfExists(LLVMContext &Context, ArrayRef<Value*> Vals);
129 /// getTemporary - Return a temporary MDNode, for use in constructing
130 /// cyclic MDNode structures. A temporary MDNode is not uniqued,
131 /// may be RAUW'd, and must be manually deleted with deleteTemporary.
132 static MDNode *getTemporary(LLVMContext &Context, ArrayRef<Value*> Vals);
134 /// deleteTemporary - Deallocate a node created by getTemporary. The
135 /// node must not have any users.
136 static void deleteTemporary(MDNode *N);
138 /// getOperand - Return specified operand.
139 Value *getOperand(unsigned i) const;
141 /// getNumOperands - Return number of MDNode operands.
142 unsigned getNumOperands() const { return NumOperands; }
144 /// isFunctionLocal - Return whether MDNode is local to a function.
145 bool isFunctionLocal() const {
146 return (getSubclassDataFromValue() & FunctionLocalBit) != 0;
149 // getFunction - If this metadata is function-local and recursively has a
150 // function-local operand, return the first such operand's parent function.
151 // Otherwise, return null. getFunction() should not be used for performance-
152 // critical code because it recursively visits all the MDNode's operands.
153 const Function *getFunction() const;
155 /// Profile - calculate a unique identifier for this MDNode to collapse
157 void Profile(FoldingSetNodeID &ID) const;
159 /// Methods for support type inquiry through isa, cast, and dyn_cast:
160 static inline bool classof(const MDNode *) { return true; }
161 static bool classof(const Value *V) {
162 return V->getValueID() == MDNodeVal;
165 // destroy - Delete this node. Only when there are no uses.
168 bool isNotUniqued() const {
169 return (getSubclassDataFromValue() & NotUniquedBit) != 0;
171 void setIsNotUniqued();
173 // Shadow Value::setValueSubclassData with a private forwarding method so that
174 // any future subclasses cannot accidentally use it.
175 void setValueSubclassData(unsigned short D) {
176 Value::setValueSubclassData(D);
180 //===----------------------------------------------------------------------===//
181 /// NamedMDNode - a tuple of MDNodes. Despite its name, a NamedMDNode isn't
182 /// itself an MDNode. NamedMDNodes belong to modules, have names, and contain
183 /// lists of MDNodes.
184 class NamedMDNode : public ilist_node<NamedMDNode> {
185 friend class SymbolTableListTraits<NamedMDNode, Module>;
186 friend struct ilist_traits<NamedMDNode>;
187 friend class LLVMContextImpl;
189 NamedMDNode(const NamedMDNode &); // DO NOT IMPLEMENT
193 void *Operands; // SmallVector<TrackingVH<MDNode>, 4>
195 void setParent(Module *M) { Parent = M; }
197 explicit NamedMDNode(const Twine &N);
200 /// eraseFromParent - Drop all references and remove the node from parent
202 void eraseFromParent();
204 /// dropAllReferences - Remove all uses and clear node vector.
205 void dropAllReferences();
207 /// ~NamedMDNode - Destroy NamedMDNode.
210 /// getParent - Get the module that holds this named metadata collection.
211 inline Module *getParent() { return Parent; }
212 inline const Module *getParent() const { return Parent; }
214 /// getOperand - Return specified operand.
215 MDNode *getOperand(unsigned i) const;
217 /// getNumOperands - Return the number of NamedMDNode operands.
218 unsigned getNumOperands() const;
220 /// addOperand - Add metadata operand.
221 void addOperand(MDNode *M);
223 /// getName - Return a constant reference to this named metadata's name.
224 StringRef getName() const;
226 /// print - Implement operator<< on NamedMDNode.
227 void print(raw_ostream &ROS, AssemblyAnnotationWriter *AAW = 0) const;
229 /// dump() - Allow printing of NamedMDNodes from the debugger.
233 } // end llvm namespace