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 MDString(const MDString &); // DO NOT IMPLEMENT 40 41 StringRef Str; 42 explicit MDString(LLVMContext &C, StringRef S); 43 44 public: 45 static MDString *get(LLVMContext &Context, StringRef Str); 46 static MDString *get(LLVMContext &Context, const char *Str) { 47 return get(Context, Str ? StringRef(Str) : StringRef()); 48 } 49 50 StringRef getString() const { return Str; } 51 52 unsigned getLength() const { return (unsigned)Str.size(); } 53 54 typedef StringRef::iterator iterator; 55 56 /// begin() - Pointer to the first byte of the string. 57 /// 58 iterator begin() const { return Str.begin(); } 59 60 /// end() - Pointer to one byte past the end of the string. 61 /// 62 iterator end() const { return Str.end(); } 63 64 /// Methods for support type inquiry through isa, cast, and dyn_cast: 65 static inline bool classof(const MDString *) { return true; } 66 static bool classof(const Value *V) { 67 return V->getValueID() == MDStringVal; 68 } 69 }; 70 71 72 class MDNodeOperand; 73 74 //===----------------------------------------------------------------------===// 75 /// MDNode - a tuple of other values. 76 class MDNode : public Value, public FoldingSetNode { 77 MDNode(const MDNode &); // DO NOT IMPLEMENT 78 void operator=(const MDNode &); // DO NOT IMPLEMENT 79 friend class MDNodeOperand; 80 friend class LLVMContextImpl; 81 82 /// NumOperands - This many 'MDNodeOperand' items are co-allocated onto the 83 /// end of this MDNode. 84 unsigned NumOperands; 85 86 // Subclass data enums. 87 enum { 88 /// FunctionLocalBit - This bit is set if this MDNode is function local. 89 /// This is true when it (potentially transitively) contains a reference to 90 /// something in a function, like an argument, basicblock, or instruction. 91 FunctionLocalBit = 1 << 0, 92 93 /// NotUniquedBit - This is set on MDNodes that are not uniqued because they 94 /// have a null operand. 95 NotUniquedBit = 1 << 1, 96 97 /// DestroyFlag - This bit is set by destroy() so the destructor can assert 98 /// that the node isn't being destroyed with a plain 'delete'. 99 DestroyFlag = 1 << 2 100 }; 101 102 // FunctionLocal enums. 103 enum FunctionLocalness { 104 FL_Unknown = -1, 105 FL_No = 0, 106 FL_Yes = 1 107 }; 108 109 /// replaceOperand - Replace each instance of F from the operand list of this 110 /// node with T. 111 void replaceOperand(MDNodeOperand *Op, Value *NewVal); 112 ~MDNode(); 113 114 MDNode(LLVMContext &C, ArrayRef<Value*> Vals, bool isFunctionLocal); 115 116 static MDNode *getMDNode(LLVMContext &C, ArrayRef<Value*> Vals, 117 FunctionLocalness FL, bool Insert = true); 118 public: 119 // Constructors and destructors. 120 static MDNode *get(LLVMContext &Context, ArrayRef<Value*> Vals); 121 // getWhenValsUnresolved - Construct MDNode determining function-localness 122 // from isFunctionLocal argument, not by analyzing Vals. 123 static MDNode *getWhenValsUnresolved(LLVMContext &Context, 124 ArrayRef<Value*> Vals, 125 bool isFunctionLocal); 126 127 static MDNode *getIfExists(LLVMContext &Context, ArrayRef<Value*> Vals); 128 129 /// getTemporary - Return a temporary MDNode, for use in constructing 130 /// cyclic MDNode structures. A temporary MDNode is not uniqued, 131 /// may be RAUW'd, and must be manually deleted with deleteTemporary. 132 static MDNode *getTemporary(LLVMContext &Context, ArrayRef<Value*> Vals); 133 134 /// deleteTemporary - Deallocate a node created by getTemporary. The 135 /// node must not have any users. 136 static void deleteTemporary(MDNode *N); 137 138 /// getOperand - Return specified operand. 139 Value *getOperand(unsigned i) const; 140 141 /// getNumOperands - Return number of MDNode operands. 142 unsigned getNumOperands() const { return NumOperands; } 143 144 /// isFunctionLocal - Return whether MDNode is local to a function. 145 bool isFunctionLocal() const { 146 return (getSubclassDataFromValue() & FunctionLocalBit) != 0; 147 } 148 149 // 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; 154 155 /// Profile - calculate a unique identifier for this MDNode to collapse 156 /// duplicates 157 void Profile(FoldingSetNodeID &ID) const; 158 159 /// Methods for support type inquiry through isa, cast, and dyn_cast: 160 static inline bool classof(const MDNode *) { return true; } 161 static bool classof(const Value *V) { 162 return V->getValueID() == MDNodeVal; 163 } 164 private: 165 // destroy - Delete this node. Only when there are no uses. 166 void destroy(); 167 168 bool isNotUniqued() const { 169 return (getSubclassDataFromValue() & NotUniquedBit) != 0; 170 } 171 void setIsNotUniqued(); 172 173 // Shadow Value::setValueSubclassData with a private forwarding method so that 174 // any future subclasses cannot accidentally use it. 175 void setValueSubclassData(unsigned short D) { 176 Value::setValueSubclassData(D); 177 } 178 }; 179 180 //===----------------------------------------------------------------------===// 181 /// NamedMDNode - a tuple of MDNodes. Despite its name, a NamedMDNode isn't 182 /// itself an MDNode. NamedMDNodes belong to modules, have names, and contain 183 /// lists of MDNodes. 184 class NamedMDNode : public ilist_node<NamedMDNode> { 185 friend class SymbolTableListTraits<NamedMDNode, Module>; 186 friend struct ilist_traits<NamedMDNode>; 187 friend class LLVMContextImpl; 188 friend class Module; 189 NamedMDNode(const NamedMDNode &); // DO NOT IMPLEMENT 190 191 std::string Name; 192 Module *Parent; 193 void *Operands; // SmallVector<TrackingVH<MDNode>, 4> 194 195 void setParent(Module *M) { Parent = M; } 196 197 explicit NamedMDNode(const Twine &N); 198 199 public: 200 /// eraseFromParent - Drop all references and remove the node from parent 201 /// module. 202 void eraseFromParent(); 203 204 /// dropAllReferences - Remove all uses and clear node vector. 205 void dropAllReferences(); 206 207 /// ~NamedMDNode - Destroy NamedMDNode. 208 ~NamedMDNode(); 209 210 /// getParent - Get the module that holds this named metadata collection. 211 inline Module *getParent() { return Parent; } 212 inline const Module *getParent() const { return Parent; } 213 214 /// getOperand - Return specified operand. 215 MDNode *getOperand(unsigned i) const; 216 217 /// getNumOperands - Return the number of NamedMDNode operands. 218 unsigned getNumOperands() const; 219 220 /// addOperand - Add metadata operand. 221 void addOperand(MDNode *M); 222 223 /// getName - Return a constant reference to this named metadata's name. 224 StringRef getName() const; 225 226 /// print - Implement operator<< on NamedMDNode. 227 void print(raw_ostream &ROS, AssemblyAnnotationWriter *AAW = 0) const; 228 }; 229 230 } // end llvm namespace 231 232 #endif 233
