1 //===-- llvm/Metadata.h - Metadata definitions ------------------*- C++ -*-===// 2 // 3 // The LLVM Compiler Infrastructure 4 // 5 // This file is distributed under the University of Illinois Open Source 6 // License. See LICENSE.TXT for details. 7 // 8 //===----------------------------------------------------------------------===// 9 // 10 /// @file 11 /// This file contains the declarations for metadata subclasses. 12 /// They represent the different flavors of metadata that live in LLVM. 13 // 14 //===----------------------------------------------------------------------===// 15 16 #ifndef LLVM_METADATA_H 17 #define LLVM_METADATA_H 18 19 #include "llvm/Value.h" 20 #include "llvm/ADT/ArrayRef.h" 21 #include "llvm/ADT/FoldingSet.h" 22 #include "llvm/ADT/ilist_node.h" 23 24 namespace llvm { 25 class Constant; 26 class Instruction; 27 class LLVMContext; 28 class Module; 29 template <typename T> class SmallVectorImpl; 30 template<typename ValueSubClass, typename ItemParentClass> 31 class SymbolTableListTraits; 32 33 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 41 42 explicit MDString(LLVMContext &C); 43 public: 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()); 47 } 48 49 StringRef getString() const { return getName(); } 50 51 unsigned getLength() const { return (unsigned)getName().size(); } 52 53 typedef StringRef::iterator iterator; 54 55 /// begin() - Pointer to the first byte of the string. 56 iterator begin() const { return getName().begin(); } 57 58 /// end() - Pointer to one byte past the end of the string. 59 iterator end() const { return getName().end(); } 60 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; 65 } 66 }; 67 68 69 class MDNodeOperand; 70 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>; 79 80 /// Hash - If the MDNode is uniqued cache the hash to speed up lookup. 81 unsigned Hash; 82 83 /// NumOperands - This many 'MDNodeOperand' items are co-allocated onto the 84 /// end of this MDNode. 85 unsigned NumOperands; 86 87 // Subclass data enums. 88 enum { 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, 93 94 /// NotUniquedBit - This is set on MDNodes that are not uniqued because they 95 /// have a null operand. 96 NotUniquedBit = 1 << 1, 97 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'. 100 DestroyFlag = 1 << 2 101 }; 102 103 // FunctionLocal enums. 104 enum FunctionLocalness { 105 FL_Unknown = -1, 106 FL_No = 0, 107 FL_Yes = 1 108 }; 109 110 /// replaceOperand - Replace each instance of F from the operand list of this 111 /// node with T. 112 void replaceOperand(MDNodeOperand *Op, Value *NewVal); 113 ~MDNode(); 114 115 MDNode(LLVMContext &C, ArrayRef<Value*> Vals, bool isFunctionLocal); 116 117 static MDNode *getMDNode(LLVMContext &C, ArrayRef<Value*> Vals, 118 FunctionLocalness FL, bool Insert = true); 119 public: 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); 127 128 static MDNode *getIfExists(LLVMContext &Context, ArrayRef<Value*> Vals); 129 130 /// 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); 134 135 /// deleteTemporary - Deallocate a node created by getTemporary. The 136 /// node must not have any users. 137 static void deleteTemporary(MDNode *N); 138 139 /// replaceOperandWith - Replace a specific operand. 140 void replaceOperandWith(unsigned i, Value *NewVal); 141 142 /// getOperand - Return specified operand. 143 Value *getOperand(unsigned i) const; 144 145 /// getNumOperands - Return number of MDNode operands. 146 unsigned getNumOperands() const { return NumOperands; } 147 148 /// isFunctionLocal - Return whether MDNode is local to a function. 149 bool isFunctionLocal() const { 150 return (getSubclassDataFromValue() & FunctionLocalBit) != 0; 151 } 152 153 // 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; 158 159 /// Profile - calculate a unique identifier for this MDNode to collapse 160 /// duplicates 161 void Profile(FoldingSetNodeID &ID) const; 162 163 /// 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; 167 } 168 169 /// 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); 173 private: 174 // destroy - Delete this node. Only when there are no uses. 175 void destroy(); 176 177 bool isNotUniqued() const { 178 return (getSubclassDataFromValue() & NotUniquedBit) != 0; 179 } 180 void setIsNotUniqued(); 181 182 // 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); 186 } 187 }; 188 189 //===----------------------------------------------------------------------===// 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; 197 friend class Module; 198 NamedMDNode(const NamedMDNode &); // DO NOT IMPLEMENT 199 200 std::string Name; 201 Module *Parent; 202 void *Operands; // SmallVector<TrackingVH<MDNode>, 4> 203 204 void setParent(Module *M) { Parent = M; } 205 206 explicit NamedMDNode(const Twine &N); 207 208 public: 209 /// eraseFromParent - Drop all references and remove the node from parent 210 /// module. 211 void eraseFromParent(); 212 213 /// dropAllReferences - Remove all uses and clear node vector. 214 void dropAllReferences(); 215 216 /// ~NamedMDNode - Destroy NamedMDNode. 217 ~NamedMDNode(); 218 219 /// getParent - Get the module that holds this named metadata collection. 220 inline Module *getParent() { return Parent; } 221 inline const Module *getParent() const { return Parent; } 222 223 /// getOperand - Return specified operand. 224 MDNode *getOperand(unsigned i) const; 225 226 /// getNumOperands - Return the number of NamedMDNode operands. 227 unsigned getNumOperands() const; 228 229 /// addOperand - Add metadata operand. 230 void addOperand(MDNode *M); 231 232 /// getName - Return a constant reference to this named metadata's name. 233 StringRef getName() const; 234 235 /// print - Implement operator<< on NamedMDNode. 236 void print(raw_ostream &ROS, AssemblyAnnotationWriter *AAW = 0) const; 237 238 /// dump() - Allow printing of NamedMDNodes from the debugger. 239 void dump() const; 240 }; 241 242 } // end llvm namespace 243 244 #endif 245
