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 = 2 // 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 explicit AAMDNodes(MDNode *T = nullptr, MDNode *S = nullptr,
75 : TBAA(T), Scope(S), NoAlias(N) {}
77 bool operator==(const AAMDNodes &A) const {
78 return TBAA == A.TBAA && Scope == A.Scope && NoAlias == A.NoAlias;
81 bool operator!=(const AAMDNodes &A) const { return !(*this == A); }
83 LLVM_EXPLICIT operator bool() const { return TBAA || Scope || NoAlias; }
85 /// TBAA - The tag for type-based alias analysis.
88 /// Scope - The tag for alias scope specification (used with noalias).
91 /// NoAlias - The tag specifying the noalias scope.
95 // Specialize DenseMapInfo for AAMDNodes.
97 struct DenseMapInfo<AAMDNodes> {
98 static inline AAMDNodes getEmptyKey() {
99 return AAMDNodes(DenseMapInfo<MDNode *>::getEmptyKey(), 0, 0);
101 static inline AAMDNodes getTombstoneKey() {
102 return AAMDNodes(DenseMapInfo<MDNode *>::getTombstoneKey(), 0, 0);
104 static unsigned getHashValue(const AAMDNodes &Val) {
105 return DenseMapInfo<MDNode *>::getHashValue(Val.TBAA) ^
106 DenseMapInfo<MDNode *>::getHashValue(Val.Scope) ^
107 DenseMapInfo<MDNode *>::getHashValue(Val.NoAlias);
109 static bool isEqual(const AAMDNodes &LHS, const AAMDNodes &RHS) {
116 //===----------------------------------------------------------------------===//
117 /// MDNode - a tuple of other values.
118 class MDNode : public Value, public FoldingSetNode {
119 MDNode(const MDNode &) LLVM_DELETED_FUNCTION;
120 void operator=(const MDNode &) LLVM_DELETED_FUNCTION;
121 friend class MDNodeOperand;
122 friend class LLVMContextImpl;
123 friend struct FoldingSetTrait<MDNode>;
125 /// Hash - If the MDNode is uniqued cache the hash to speed up lookup.
128 /// NumOperands - This many 'MDNodeOperand' items are co-allocated onto the
129 /// end of this MDNode.
130 unsigned NumOperands;
132 // Subclass data enums.
134 /// FunctionLocalBit - This bit is set if this MDNode is function local.
135 /// This is true when it (potentially transitively) contains a reference to
136 /// something in a function, like an argument, basicblock, or instruction.
137 FunctionLocalBit = 1 << 0,
139 /// NotUniquedBit - This is set on MDNodes that are not uniqued because they
140 /// have a null operand.
141 NotUniquedBit = 1 << 1,
143 /// DestroyFlag - This bit is set by destroy() so the destructor can assert
144 /// that the node isn't being destroyed with a plain 'delete'.
148 // FunctionLocal enums.
149 enum FunctionLocalness {
155 /// replaceOperand - Replace each instance of F from the operand list of this
157 void replaceOperand(MDNodeOperand *Op, Value *NewVal);
160 MDNode(LLVMContext &C, ArrayRef<Value*> Vals, bool isFunctionLocal);
162 static MDNode *getMDNode(LLVMContext &C, ArrayRef<Value*> Vals,
163 FunctionLocalness FL, bool Insert = true);
165 // Constructors and destructors.
166 static MDNode *get(LLVMContext &Context, ArrayRef<Value*> Vals);
167 // getWhenValsUnresolved - Construct MDNode determining function-localness
168 // from isFunctionLocal argument, not by analyzing Vals.
169 static MDNode *getWhenValsUnresolved(LLVMContext &Context,
170 ArrayRef<Value*> Vals,
171 bool isFunctionLocal);
173 static MDNode *getIfExists(LLVMContext &Context, ArrayRef<Value*> Vals);
175 /// getTemporary - Return a temporary MDNode, for use in constructing
176 /// cyclic MDNode structures. A temporary MDNode is not uniqued,
177 /// may be RAUW'd, and must be manually deleted with deleteTemporary.
178 static MDNode *getTemporary(LLVMContext &Context, ArrayRef<Value*> Vals);
180 /// deleteTemporary - Deallocate a node created by getTemporary. The
181 /// node must not have any users.
182 static void deleteTemporary(MDNode *N);
184 /// replaceOperandWith - Replace a specific operand.
185 void replaceOperandWith(unsigned i, Value *NewVal);
187 /// getOperand - Return specified operand.
188 Value *getOperand(unsigned i) const LLVM_READONLY;
190 /// getNumOperands - Return number of MDNode operands.
191 unsigned getNumOperands() const { return NumOperands; }
193 /// isFunctionLocal - Return whether MDNode is local to a function.
194 bool isFunctionLocal() const {
195 return (getSubclassDataFromValue() & FunctionLocalBit) != 0;
198 // getFunction - If this metadata is function-local and recursively has a
199 // function-local operand, return the first such operand's parent function.
200 // Otherwise, return null. getFunction() should not be used for performance-
201 // critical code because it recursively visits all the MDNode's operands.
202 const Function *getFunction() const;
204 /// Profile - calculate a unique identifier for this MDNode to collapse
206 void Profile(FoldingSetNodeID &ID) const;
208 /// Methods for support type inquiry through isa, cast, and dyn_cast:
209 static bool classof(const Value *V) {
210 return V->getValueID() == MDNodeVal;
213 /// Check whether MDNode is a vtable access.
214 bool isTBAAVtableAccess() const;
216 /// Methods for metadata merging.
217 static MDNode *concatenate(MDNode *A, MDNode *B);
218 static MDNode *intersect(MDNode *A, MDNode *B);
219 static MDNode *getMostGenericTBAA(MDNode *A, MDNode *B);
220 static AAMDNodes getMostGenericAA(const AAMDNodes &A, const AAMDNodes &B);
221 static MDNode *getMostGenericFPMath(MDNode *A, MDNode *B);
222 static MDNode *getMostGenericRange(MDNode *A, MDNode *B);
224 // destroy - Delete this node. Only when there are no uses.
227 bool isNotUniqued() const {
228 return (getSubclassDataFromValue() & NotUniquedBit) != 0;
230 void setIsNotUniqued();
232 // Shadow Value::setValueSubclassData with a private forwarding method so that
233 // any future subclasses cannot accidentally use it.
234 void setValueSubclassData(unsigned short D) {
235 Value::setValueSubclassData(D);
239 //===----------------------------------------------------------------------===//
240 /// NamedMDNode - a tuple of MDNodes. Despite its name, a NamedMDNode isn't
241 /// itself an MDNode. NamedMDNodes belong to modules, have names, and contain
242 /// lists of MDNodes.
243 class NamedMDNode : public ilist_node<NamedMDNode> {
244 friend class SymbolTableListTraits<NamedMDNode, Module>;
245 friend struct ilist_traits<NamedMDNode>;
246 friend class LLVMContextImpl;
248 NamedMDNode(const NamedMDNode &) LLVM_DELETED_FUNCTION;
252 void *Operands; // SmallVector<TrackingVH<MDNode>, 4>
254 void setParent(Module *M) { Parent = M; }
256 explicit NamedMDNode(const Twine &N);
258 template<class T1, class T2>
259 class op_iterator_impl :
260 public std::iterator<std::bidirectional_iterator_tag, T2> {
261 const NamedMDNode *Node;
263 op_iterator_impl(const NamedMDNode *N, unsigned i) : Node(N), Idx(i) { }
265 friend class NamedMDNode;
268 op_iterator_impl() : Node(nullptr), Idx(0) { }
270 bool operator==(const op_iterator_impl &o) const { return Idx == o.Idx; }
271 bool operator!=(const op_iterator_impl &o) const { return Idx != o.Idx; }
272 op_iterator_impl &operator++() {
276 op_iterator_impl operator++(int) {
277 op_iterator_impl tmp(*this);
281 op_iterator_impl &operator--() {
285 op_iterator_impl operator--(int) {
286 op_iterator_impl tmp(*this);
291 T1 operator*() const { return Node->getOperand(Idx); }
295 /// eraseFromParent - Drop all references and remove the node from parent
297 void eraseFromParent();
299 /// dropAllReferences - Remove all uses and clear node vector.
300 void dropAllReferences();
302 /// ~NamedMDNode - Destroy NamedMDNode.
305 /// getParent - Get the module that holds this named metadata collection.
306 inline Module *getParent() { return Parent; }
307 inline const Module *getParent() const { return Parent; }
309 /// getOperand - Return specified operand.
310 MDNode *getOperand(unsigned i) const;
312 /// getNumOperands - Return the number of NamedMDNode operands.
313 unsigned getNumOperands() const;
315 /// addOperand - Add metadata operand.
316 void addOperand(MDNode *M);
318 /// getName - Return a constant reference to this named metadata's name.
319 StringRef getName() const;
321 /// print - Implement operator<< on NamedMDNode.
322 void print(raw_ostream &ROS) const;
324 /// dump() - Allow printing of NamedMDNodes from the debugger.
327 // ---------------------------------------------------------------------------
328 // Operand Iterator interface...
330 typedef op_iterator_impl<MDNode*, MDNode> op_iterator;
331 op_iterator op_begin() { return op_iterator(this, 0); }
332 op_iterator op_end() { return op_iterator(this, getNumOperands()); }
334 typedef op_iterator_impl<const MDNode*, MDNode> const_op_iterator;
335 const_op_iterator op_begin() const { return const_op_iterator(this, 0); }
336 const_op_iterator op_end() const { return const_op_iterator(this, getNumOperands()); }
338 inline iterator_range<op_iterator> operands() {
339 return iterator_range<op_iterator>(op_begin(), op_end());
341 inline iterator_range<const_op_iterator> operands() const {
342 return iterator_range<const_op_iterator>(op_begin(), op_end());
346 } // end llvm namespace