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 virtual void anchor();
40 MDString(const MDString &); // DO NOT IMPLEMENT
42 explicit MDString(LLVMContext &C);
44 static MDString *get(LLVMContext &Context, StringRef Str);
45 static MDString *get(LLVMContext &Context, const char *Str) {
46 return get(Context, Str ? StringRef(Str) : StringRef());
49 StringRef getString() const { return getName(); }
51 unsigned getLength() const { return (unsigned)getName().size(); }
53 typedef StringRef::iterator iterator;
55 /// begin() - Pointer to the first byte of the string.
56 iterator begin() const { return getName().begin(); }
58 /// end() - Pointer to one byte past the end of the string.
59 iterator end() const { return getName().end(); }
61 /// Methods for support type inquiry through isa, cast, and dyn_cast:
62 static inline bool classof(const MDString *) { return true; }
63 static bool classof(const Value *V) {
64 return V->getValueID() == MDStringVal;
71 //===----------------------------------------------------------------------===//
72 /// MDNode - a tuple of other values.
73 class MDNode : public Value, public FoldingSetNode {
74 MDNode(const MDNode &); // DO NOT IMPLEMENT
75 void operator=(const MDNode &); // DO NOT IMPLEMENT
76 friend class MDNodeOperand;
77 friend class LLVMContextImpl;
78 friend struct FoldingSetTrait<MDNode>;
80 /// Hash - If the MDNode is uniqued cache the hash to speed up lookup.
83 /// NumOperands - This many 'MDNodeOperand' items are co-allocated onto the
84 /// end of this MDNode.
87 // Subclass data enums.
89 /// FunctionLocalBit - This bit is set if this MDNode is function local.
90 /// This is true when it (potentially transitively) contains a reference to
91 /// something in a function, like an argument, basicblock, or instruction.
92 FunctionLocalBit = 1 << 0,
94 /// NotUniquedBit - This is set on MDNodes that are not uniqued because they
95 /// have a null operand.
96 NotUniquedBit = 1 << 1,
98 /// DestroyFlag - This bit is set by destroy() so the destructor can assert
99 /// that the node isn't being destroyed with a plain 'delete'.
103 // FunctionLocal enums.
104 enum FunctionLocalness {
110 /// replaceOperand - Replace each instance of F from the operand list of this
112 void replaceOperand(MDNodeOperand *Op, Value *NewVal);
115 MDNode(LLVMContext &C, ArrayRef<Value*> Vals, bool isFunctionLocal);
117 static MDNode *getMDNode(LLVMContext &C, ArrayRef<Value*> Vals,
118 FunctionLocalness FL, bool Insert = true);
120 // Constructors and destructors.
121 static MDNode *get(LLVMContext &Context, ArrayRef<Value*> Vals);
122 // getWhenValsUnresolved - Construct MDNode determining function-localness
123 // from isFunctionLocal argument, not by analyzing Vals.
124 static MDNode *getWhenValsUnresolved(LLVMContext &Context,
125 ArrayRef<Value*> Vals,
126 bool isFunctionLocal);
128 static MDNode *getIfExists(LLVMContext &Context, ArrayRef<Value*> Vals);
130 /// getTemporary - Return a temporary MDNode, for use in constructing
131 /// cyclic MDNode structures. A temporary MDNode is not uniqued,
132 /// may be RAUW'd, and must be manually deleted with deleteTemporary.
133 static MDNode *getTemporary(LLVMContext &Context, ArrayRef<Value*> Vals);
135 /// deleteTemporary - Deallocate a node created by getTemporary. The
136 /// node must not have any users.
137 static void deleteTemporary(MDNode *N);
139 /// replaceOperandWith - Replace a specific operand.
140 void replaceOperandWith(unsigned i, Value *NewVal);
142 /// getOperand - Return specified operand.
143 Value *getOperand(unsigned i) const;
145 /// getNumOperands - Return number of MDNode operands.
146 unsigned getNumOperands() const { return NumOperands; }
148 /// isFunctionLocal - Return whether MDNode is local to a function.
149 bool isFunctionLocal() const {
150 return (getSubclassDataFromValue() & FunctionLocalBit) != 0;
153 // getFunction - If this metadata is function-local and recursively has a
154 // function-local operand, return the first such operand's parent function.
155 // Otherwise, return null. getFunction() should not be used for performance-
156 // critical code because it recursively visits all the MDNode's operands.
157 const Function *getFunction() const;
159 /// Profile - calculate a unique identifier for this MDNode to collapse
161 void Profile(FoldingSetNodeID &ID) const;
163 /// Methods for support type inquiry through isa, cast, and dyn_cast:
164 static inline bool classof(const MDNode *) { return true; }
165 static bool classof(const Value *V) {
166 return V->getValueID() == MDNodeVal;
169 /// Methods for metadata merging.
170 static MDNode *getMostGenericTBAA(MDNode *A, MDNode *B);
171 static MDNode *getMostGenericFPMath(MDNode *A, MDNode *B);
172 static MDNode *getMostGenericRange(MDNode *A, MDNode *B);
174 // destroy - Delete this node. Only when there are no uses.
177 bool isNotUniqued() const {
178 return (getSubclassDataFromValue() & NotUniquedBit) != 0;
180 void setIsNotUniqued();
182 // Shadow Value::setValueSubclassData with a private forwarding method so that
183 // any future subclasses cannot accidentally use it.
184 void setValueSubclassData(unsigned short D) {
185 Value::setValueSubclassData(D);
189 //===----------------------------------------------------------------------===//
190 /// NamedMDNode - a tuple of MDNodes. Despite its name, a NamedMDNode isn't
191 /// itself an MDNode. NamedMDNodes belong to modules, have names, and contain
192 /// lists of MDNodes.
193 class NamedMDNode : public ilist_node<NamedMDNode> {
194 friend class SymbolTableListTraits<NamedMDNode, Module>;
195 friend struct ilist_traits<NamedMDNode>;
196 friend class LLVMContextImpl;
198 NamedMDNode(const NamedMDNode &); // DO NOT IMPLEMENT
202 void *Operands; // SmallVector<TrackingVH<MDNode>, 4>
204 void setParent(Module *M) { Parent = M; }
206 explicit NamedMDNode(const Twine &N);
209 /// eraseFromParent - Drop all references and remove the node from parent
211 void eraseFromParent();
213 /// dropAllReferences - Remove all uses and clear node vector.
214 void dropAllReferences();
216 /// ~NamedMDNode - Destroy NamedMDNode.
219 /// getParent - Get the module that holds this named metadata collection.
220 inline Module *getParent() { return Parent; }
221 inline const Module *getParent() const { return Parent; }
223 /// getOperand - Return specified operand.
224 MDNode *getOperand(unsigned i) const;
226 /// getNumOperands - Return the number of NamedMDNode operands.
227 unsigned getNumOperands() const;
229 /// addOperand - Add metadata operand.
230 void addOperand(MDNode *M);
232 /// getName - Return a constant reference to this named metadata's name.
233 StringRef getName() const;
235 /// print - Implement operator<< on NamedMDNode.
236 void print(raw_ostream &ROS, AssemblyAnnotationWriter *AAW = 0) const;
238 /// dump() - Allow printing of NamedMDNodes from the debugger.
242 } // end llvm namespace