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/DenseMap.h"
21 #include "llvm/ADT/FoldingSet.h"
22 #include "llvm/ADT/ilist_node.h"
23 #include "llvm/ADT/iterator_range.h"
24 #include "llvm/IR/Value.h"
29 template<typename ValueSubClass, typename ItemParentClass>
30 class SymbolTableListTraits;
33 enum LLVMConstants : uint32_t {
34 DEBUG_METADATA_VERSION = 1 // Current debug info version number.
37 //===----------------------------------------------------------------------===//
38 /// MDString - a single uniqued string.
39 /// These are used to efficiently contain a byte sequence for metadata.
40 /// MDString is always unnamed.
41 class MDString : public Value {
42 virtual void anchor();
43 MDString(const MDString &) LLVM_DELETED_FUNCTION;
45 explicit MDString(LLVMContext &C);
47 static MDString *get(LLVMContext &Context, StringRef Str);
48 static MDString *get(LLVMContext &Context, const char *Str) {
49 return get(Context, Str ? StringRef(Str) : StringRef());
52 StringRef getString() const { return getName(); }
54 unsigned getLength() const { return (unsigned)getName().size(); }
56 typedef StringRef::iterator iterator;
58 /// begin() - Pointer to the first byte of the string.
59 iterator begin() const { return getName().begin(); }
61 /// end() - Pointer to one byte past the end of the string.
62 iterator end() const { return getName().end(); }
64 /// Methods for support type inquiry through isa, cast, and dyn_cast:
65 static bool classof(const Value *V) {
66 return V->getValueID() == MDStringVal;
70 /// AAMDNodes - A collection of metadata nodes that might be associated with a
71 /// memory access used by the alias-analysis infrastructure.
73 AAMDNodes(MDNode *T = nullptr, MDNode *S = nullptr, MDNode *N = nullptr)
74 : TBAA(T), Scope(S), NoAlias(N) {}
76 bool operator == (const AAMDNodes &A) const {
80 bool operator != (const AAMDNodes &A) const {
84 operator bool() const {
85 return TBAA || Scope || NoAlias;
88 /// TBAA - The tag for type-based alias analysis.
91 /// Scope - The tag for alias scope specification (used with noalias).
94 /// NoAlias - The tag specifying the noalias scope.
98 bool equals(const AAMDNodes &A) const {
99 return TBAA == A.TBAA && Scope == A.Scope && NoAlias == A.NoAlias;
103 // Specialize DenseMapInfo for AAMDNodes.
105 struct DenseMapInfo<AAMDNodes> {
106 static inline AAMDNodes getEmptyKey() {
107 return AAMDNodes(DenseMapInfo<MDNode *>::getEmptyKey(), 0, 0);
109 static inline AAMDNodes getTombstoneKey() {
110 return AAMDNodes(DenseMapInfo<MDNode *>::getTombstoneKey(), 0, 0);
112 static unsigned getHashValue(const AAMDNodes &Val) {
113 return DenseMapInfo<MDNode *>::getHashValue(Val.TBAA) ^
114 DenseMapInfo<MDNode *>::getHashValue(Val.Scope) ^
115 DenseMapInfo<MDNode *>::getHashValue(Val.NoAlias);
117 static bool isEqual(const AAMDNodes &LHS, const AAMDNodes &RHS) {
124 //===----------------------------------------------------------------------===//
125 /// MDNode - a tuple of other values.
126 class MDNode : public Value, public FoldingSetNode {
127 MDNode(const MDNode &) LLVM_DELETED_FUNCTION;
128 void operator=(const MDNode &) LLVM_DELETED_FUNCTION;
129 friend class MDNodeOperand;
130 friend class LLVMContextImpl;
131 friend struct FoldingSetTrait<MDNode>;
133 /// Hash - If the MDNode is uniqued cache the hash to speed up lookup.
136 /// NumOperands - This many 'MDNodeOperand' items are co-allocated onto the
137 /// end of this MDNode.
138 unsigned NumOperands;
140 // Subclass data enums.
142 /// FunctionLocalBit - This bit is set if this MDNode is function local.
143 /// This is true when it (potentially transitively) contains a reference to
144 /// something in a function, like an argument, basicblock, or instruction.
145 FunctionLocalBit = 1 << 0,
147 /// NotUniquedBit - This is set on MDNodes that are not uniqued because they
148 /// have a null operand.
149 NotUniquedBit = 1 << 1,
151 /// DestroyFlag - This bit is set by destroy() so the destructor can assert
152 /// that the node isn't being destroyed with a plain 'delete'.
156 // FunctionLocal enums.
157 enum FunctionLocalness {
163 /// replaceOperand - Replace each instance of F from the operand list of this
165 void replaceOperand(MDNodeOperand *Op, Value *NewVal);
168 MDNode(LLVMContext &C, ArrayRef<Value*> Vals, bool isFunctionLocal);
170 static MDNode *getMDNode(LLVMContext &C, ArrayRef<Value*> Vals,
171 FunctionLocalness FL, bool Insert = true);
173 // Constructors and destructors.
174 static MDNode *get(LLVMContext &Context, ArrayRef<Value*> Vals);
175 // getWhenValsUnresolved - Construct MDNode determining function-localness
176 // from isFunctionLocal argument, not by analyzing Vals.
177 static MDNode *getWhenValsUnresolved(LLVMContext &Context,
178 ArrayRef<Value*> Vals,
179 bool isFunctionLocal);
181 static MDNode *getIfExists(LLVMContext &Context, ArrayRef<Value*> Vals);
183 /// getTemporary - Return a temporary MDNode, for use in constructing
184 /// cyclic MDNode structures. A temporary MDNode is not uniqued,
185 /// may be RAUW'd, and must be manually deleted with deleteTemporary.
186 static MDNode *getTemporary(LLVMContext &Context, ArrayRef<Value*> Vals);
188 /// deleteTemporary - Deallocate a node created by getTemporary. The
189 /// node must not have any users.
190 static void deleteTemporary(MDNode *N);
192 /// replaceOperandWith - Replace a specific operand.
193 void replaceOperandWith(unsigned i, Value *NewVal);
195 /// getOperand - Return specified operand.
196 Value *getOperand(unsigned i) const LLVM_READONLY;
198 /// getNumOperands - Return number of MDNode operands.
199 unsigned getNumOperands() const { return NumOperands; }
201 /// isFunctionLocal - Return whether MDNode is local to a function.
202 bool isFunctionLocal() const {
203 return (getSubclassDataFromValue() & FunctionLocalBit) != 0;
206 // getFunction - If this metadata is function-local and recursively has a
207 // function-local operand, return the first such operand's parent function.
208 // Otherwise, return null. getFunction() should not be used for performance-
209 // critical code because it recursively visits all the MDNode's operands.
210 const Function *getFunction() const;
212 /// Profile - calculate a unique identifier for this MDNode to collapse
214 void Profile(FoldingSetNodeID &ID) const;
216 /// Methods for support type inquiry through isa, cast, and dyn_cast:
217 static bool classof(const Value *V) {
218 return V->getValueID() == MDNodeVal;
221 /// Check whether MDNode is a vtable access.
222 bool isTBAAVtableAccess() const;
224 /// Methods for metadata merging.
225 static MDNode *concatenate(MDNode *A, MDNode *B);
226 static MDNode *intersect(MDNode *A, MDNode *B);
227 static MDNode *getMostGenericTBAA(MDNode *A, MDNode *B);
228 static AAMDNodes getMostGenericAA(const AAMDNodes &A, const AAMDNodes &B);
229 static MDNode *getMostGenericFPMath(MDNode *A, MDNode *B);
230 static MDNode *getMostGenericRange(MDNode *A, MDNode *B);
232 // destroy - Delete this node. Only when there are no uses.
235 bool isNotUniqued() const {
236 return (getSubclassDataFromValue() & NotUniquedBit) != 0;
238 void setIsNotUniqued();
240 // Shadow Value::setValueSubclassData with a private forwarding method so that
241 // any future subclasses cannot accidentally use it.
242 void setValueSubclassData(unsigned short D) {
243 Value::setValueSubclassData(D);
247 //===----------------------------------------------------------------------===//
248 /// NamedMDNode - a tuple of MDNodes. Despite its name, a NamedMDNode isn't
249 /// itself an MDNode. NamedMDNodes belong to modules, have names, and contain
250 /// lists of MDNodes.
251 class NamedMDNode : public ilist_node<NamedMDNode> {
252 friend class SymbolTableListTraits<NamedMDNode, Module>;
253 friend struct ilist_traits<NamedMDNode>;
254 friend class LLVMContextImpl;
256 NamedMDNode(const NamedMDNode &) LLVM_DELETED_FUNCTION;
260 void *Operands; // SmallVector<TrackingVH<MDNode>, 4>
262 void setParent(Module *M) { Parent = M; }
264 explicit NamedMDNode(const Twine &N);
266 template<class T1, class T2>
267 class op_iterator_impl :
268 public std::iterator<std::bidirectional_iterator_tag, T2> {
269 const NamedMDNode *Node;
271 op_iterator_impl(const NamedMDNode *N, unsigned i) : Node(N), Idx(i) { }
273 friend class NamedMDNode;
276 op_iterator_impl() : Node(nullptr), Idx(0) { }
278 bool operator==(const op_iterator_impl &o) const { return Idx == o.Idx; }
279 bool operator!=(const op_iterator_impl &o) const { return Idx != o.Idx; }
280 op_iterator_impl &operator++() {
284 op_iterator_impl operator++(int) {
285 op_iterator_impl tmp(*this);
289 op_iterator_impl &operator--() {
293 op_iterator_impl operator--(int) {
294 op_iterator_impl tmp(*this);
299 T1 operator*() const { return Node->getOperand(Idx); }
303 /// eraseFromParent - Drop all references and remove the node from parent
305 void eraseFromParent();
307 /// dropAllReferences - Remove all uses and clear node vector.
308 void dropAllReferences();
310 /// ~NamedMDNode - Destroy NamedMDNode.
313 /// getParent - Get the module that holds this named metadata collection.
314 inline Module *getParent() { return Parent; }
315 inline const Module *getParent() const { return Parent; }
317 /// getOperand - Return specified operand.
318 MDNode *getOperand(unsigned i) const;
320 /// getNumOperands - Return the number of NamedMDNode operands.
321 unsigned getNumOperands() const;
323 /// addOperand - Add metadata operand.
324 void addOperand(MDNode *M);
326 /// getName - Return a constant reference to this named metadata's name.
327 StringRef getName() const;
329 /// print - Implement operator<< on NamedMDNode.
330 void print(raw_ostream &ROS) const;
332 /// dump() - Allow printing of NamedMDNodes from the debugger.
335 // ---------------------------------------------------------------------------
336 // Operand Iterator interface...
338 typedef op_iterator_impl<MDNode*, MDNode> op_iterator;
339 op_iterator op_begin() { return op_iterator(this, 0); }
340 op_iterator op_end() { return op_iterator(this, getNumOperands()); }
342 typedef op_iterator_impl<const MDNode*, MDNode> const_op_iterator;
343 const_op_iterator op_begin() const { return const_op_iterator(this, 0); }
344 const_op_iterator op_end() const { return const_op_iterator(this, getNumOperands()); }
346 inline iterator_range<op_iterator> operands() {
347 return iterator_range<op_iterator>(op_begin(), op_end());
349 inline iterator_range<const_op_iterator> operands() const {
350 return iterator_range<const_op_iterator>(op_begin(), op_end());
354 } // end llvm namespace