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_IR_METADATA_H
17 #define LLVM_IR_METADATA_H
19 #include "llvm/ADT/ArrayRef.h"
20 #include "llvm/ADT/FoldingSet.h"
21 #include "llvm/ADT/ilist_node.h"
22 #include "llvm/IR/Value.h"
27 template<typename ValueSubClass, typename ItemParentClass>
28 class SymbolTableListTraits;
31 //===----------------------------------------------------------------------===//
32 /// MDString - a single uniqued string.
33 /// These are used to efficiently contain a byte sequence for metadata.
34 /// MDString is always unnamed.
35 class MDString : public Value {
36 virtual void anchor();
37 MDString(const MDString &) LLVM_DELETED_FUNCTION;
39 explicit MDString(LLVMContext &C);
41 static MDString *get(LLVMContext &Context, StringRef Str);
42 static MDString *get(LLVMContext &Context, const char *Str) {
43 return get(Context, Str ? StringRef(Str) : StringRef());
46 StringRef getString() const { return getName(); }
48 unsigned getLength() const { return (unsigned)getName().size(); }
50 typedef StringRef::iterator iterator;
52 /// begin() - Pointer to the first byte of the string.
53 iterator begin() const { return getName().begin(); }
55 /// end() - Pointer to one byte past the end of the string.
56 iterator end() const { return getName().end(); }
58 /// Methods for support type inquiry through isa, cast, and dyn_cast:
59 static bool classof(const Value *V) {
60 return V->getValueID() == MDStringVal;
67 //===----------------------------------------------------------------------===//
68 /// MDNode - a tuple of other values.
69 class MDNode : public Value, public FoldingSetNode {
70 MDNode(const MDNode &) LLVM_DELETED_FUNCTION;
71 void operator=(const MDNode &) LLVM_DELETED_FUNCTION;
72 friend class MDNodeOperand;
73 friend class LLVMContextImpl;
74 friend struct FoldingSetTrait<MDNode>;
76 /// Hash - If the MDNode is uniqued cache the hash to speed up lookup.
79 /// NumOperands - This many 'MDNodeOperand' items are co-allocated onto the
80 /// end of this MDNode.
83 // Subclass data enums.
85 /// FunctionLocalBit - This bit is set if this MDNode is function local.
86 /// This is true when it (potentially transitively) contains a reference to
87 /// something in a function, like an argument, basicblock, or instruction.
88 FunctionLocalBit = 1 << 0,
90 /// NotUniquedBit - This is set on MDNodes that are not uniqued because they
91 /// have a null operand.
92 NotUniquedBit = 1 << 1,
94 /// DestroyFlag - This bit is set by destroy() so the destructor can assert
95 /// that the node isn't being destroyed with a plain 'delete'.
99 // FunctionLocal enums.
100 enum FunctionLocalness {
106 /// replaceOperand - Replace each instance of F from the operand list of this
108 void replaceOperand(MDNodeOperand *Op, Value *NewVal);
111 MDNode(LLVMContext &C, ArrayRef<Value*> Vals, bool isFunctionLocal);
113 static MDNode *getMDNode(LLVMContext &C, ArrayRef<Value*> Vals,
114 FunctionLocalness FL, bool Insert = true);
116 // Constructors and destructors.
117 static MDNode *get(LLVMContext &Context, ArrayRef<Value*> Vals);
118 // getWhenValsUnresolved - Construct MDNode determining function-localness
119 // from isFunctionLocal argument, not by analyzing Vals.
120 static MDNode *getWhenValsUnresolved(LLVMContext &Context,
121 ArrayRef<Value*> Vals,
122 bool isFunctionLocal);
124 static MDNode *getIfExists(LLVMContext &Context, ArrayRef<Value*> Vals);
126 /// getTemporary - Return a temporary MDNode, for use in constructing
127 /// cyclic MDNode structures. A temporary MDNode is not uniqued,
128 /// may be RAUW'd, and must be manually deleted with deleteTemporary.
129 static MDNode *getTemporary(LLVMContext &Context, ArrayRef<Value*> Vals);
131 /// deleteTemporary - Deallocate a node created by getTemporary. The
132 /// node must not have any users.
133 static void deleteTemporary(MDNode *N);
135 /// replaceOperandWith - Replace a specific operand.
136 void replaceOperandWith(unsigned i, Value *NewVal);
138 /// getOperand - Return specified operand.
139 Value *getOperand(unsigned i) const LLVM_READONLY;
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 bool classof(const Value *V) {
161 return V->getValueID() == MDNodeVal;
164 /// Check whether MDNode is a vtable access.
165 bool isTBAAVtableAccess() const;
167 /// Methods for metadata merging.
168 static MDNode *getMostGenericTBAA(MDNode *A, MDNode *B);
169 static MDNode *getMostGenericFPMath(MDNode *A, MDNode *B);
170 static MDNode *getMostGenericRange(MDNode *A, MDNode *B);
172 // destroy - Delete this node. Only when there are no uses.
175 bool isNotUniqued() const {
176 return (getSubclassDataFromValue() & NotUniquedBit) != 0;
178 void setIsNotUniqued();
180 // Shadow Value::setValueSubclassData with a private forwarding method so that
181 // any future subclasses cannot accidentally use it.
182 void setValueSubclassData(unsigned short D) {
183 Value::setValueSubclassData(D);
187 //===----------------------------------------------------------------------===//
188 /// NamedMDNode - a tuple of MDNodes. Despite its name, a NamedMDNode isn't
189 /// itself an MDNode. NamedMDNodes belong to modules, have names, and contain
190 /// lists of MDNodes.
191 class NamedMDNode : public ilist_node<NamedMDNode> {
192 friend class SymbolTableListTraits<NamedMDNode, Module>;
193 friend struct ilist_traits<NamedMDNode>;
194 friend class LLVMContextImpl;
196 NamedMDNode(const NamedMDNode &) LLVM_DELETED_FUNCTION;
200 void *Operands; // SmallVector<TrackingVH<MDNode>, 4>
202 void setParent(Module *M) { Parent = M; }
204 explicit NamedMDNode(const Twine &N);
207 /// eraseFromParent - Drop all references and remove the node from parent
209 void eraseFromParent();
211 /// dropAllReferences - Remove all uses and clear node vector.
212 void dropAllReferences();
214 /// ~NamedMDNode - Destroy NamedMDNode.
217 /// getParent - Get the module that holds this named metadata collection.
218 inline Module *getParent() { return Parent; }
219 inline const Module *getParent() const { return Parent; }
221 /// getOperand - Return specified operand.
222 MDNode *getOperand(unsigned i) const;
224 /// getNumOperands - Return the number of NamedMDNode operands.
225 unsigned getNumOperands() const;
227 /// addOperand - Add metadata operand.
228 void addOperand(MDNode *M);
230 /// getName - Return a constant reference to this named metadata's name.
231 StringRef getName() const;
233 /// print - Implement operator<< on NamedMDNode.
234 void print(raw_ostream &ROS, AssemblyAnnotationWriter *AAW = 0) const;
236 /// dump() - Allow printing of NamedMDNodes from the debugger.
240 } // end llvm namespace