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_IR_METADATA_H 17 #define LLVM_IR_METADATA_H 18 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" 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 &) LLVM_DELETED_FUNCTION; 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 bool classof(const Value *V) { 63 return V->getValueID() == MDStringVal; 64 } 65 }; 66 67 68 class MDNodeOperand; 69 70 //===----------------------------------------------------------------------===// 71 /// MDNode - a tuple of other values. 72 class MDNode : public Value, public FoldingSetNode { 73 MDNode(const MDNode &) LLVM_DELETED_FUNCTION; 74 void operator=(const MDNode &) LLVM_DELETED_FUNCTION; 75 friend class MDNodeOperand; 76 friend class LLVMContextImpl; 77 friend struct FoldingSetTrait<MDNode>; 78 79 /// Hash - If the MDNode is uniqued cache the hash to speed up lookup. 80 unsigned Hash; 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 /// replaceOperandWith - Replace a specific operand. 139 void replaceOperandWith(unsigned i, Value *NewVal); 140 141 /// getOperand - Return specified operand. 142 Value *getOperand(unsigned i) const; 143 144 /// getNumOperands - Return number of MDNode operands. 145 unsigned getNumOperands() const { return NumOperands; } 146 147 /// isFunctionLocal - Return whether MDNode is local to a function. 148 bool isFunctionLocal() const { 149 return (getSubclassDataFromValue() & FunctionLocalBit) != 0; 150 } 151 152 // getFunction - If this metadata is function-local and recursively has a 153 // function-local operand, return the first such operand's parent function. 154 // Otherwise, return null. getFunction() should not be used for performance- 155 // critical code because it recursively visits all the MDNode's operands. 156 const Function *getFunction() const; 157 158 /// Profile - calculate a unique identifier for this MDNode to collapse 159 /// duplicates 160 void Profile(FoldingSetNodeID &ID) const; 161 162 /// Methods for support type inquiry through isa, cast, and dyn_cast: 163 static bool classof(const Value *V) { 164 return V->getValueID() == MDNodeVal; 165 } 166 167 /// 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); 171 private: 172 // destroy - Delete this node. Only when there are no uses. 173 void destroy(); 174 175 bool isNotUniqued() const { 176 return (getSubclassDataFromValue() & NotUniquedBit) != 0; 177 } 178 void setIsNotUniqued(); 179 180 // 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); 184 } 185 }; 186 187 //===----------------------------------------------------------------------===// 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; 195 friend class Module; 196 NamedMDNode(const NamedMDNode &) LLVM_DELETED_FUNCTION; 197 198 std::string Name; 199 Module *Parent; 200 void *Operands; // SmallVector<TrackingVH<MDNode>, 4> 201 202 void setParent(Module *M) { Parent = M; } 203 204 explicit NamedMDNode(const Twine &N); 205 206 public: 207 /// eraseFromParent - Drop all references and remove the node from parent 208 /// module. 209 void eraseFromParent(); 210 211 /// dropAllReferences - Remove all uses and clear node vector. 212 void dropAllReferences(); 213 214 /// ~NamedMDNode - Destroy NamedMDNode. 215 ~NamedMDNode(); 216 217 /// getParent - Get the module that holds this named metadata collection. 218 inline Module *getParent() { return Parent; } 219 inline const Module *getParent() const { return Parent; } 220 221 /// getOperand - Return specified operand. 222 MDNode *getOperand(unsigned i) const; 223 224 /// getNumOperands - Return the number of NamedMDNode operands. 225 unsigned getNumOperands() const; 226 227 /// addOperand - Add metadata operand. 228 void addOperand(MDNode *M); 229 230 /// getName - Return a constant reference to this named metadata's name. 231 StringRef getName() const; 232 233 /// print - Implement operator<< on NamedMDNode. 234 void print(raw_ostream &ROS, AssemblyAnnotationWriter *AAW = 0) const; 235 236 /// dump() - Allow printing of NamedMDNodes from the debugger. 237 void dump() const; 238 }; 239 240 } // end llvm namespace 241 242 #endif 243
