1 //===-- llvm/GlobalObject.h - Class to represent global objects -*- 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 // This represents an independent object. That is, a function or a global 11 // variable, but not an alias. 12 // 13 //===----------------------------------------------------------------------===// 14 15 #ifndef LLVM_IR_GLOBALOBJECT_H 16 #define LLVM_IR_GLOBALOBJECT_H 17 18 #include "llvm/ADT/StringRef.h" 19 #include "llvm/IR/GlobalValue.h" 20 #include "llvm/IR/Value.h" 21 #include <string> 22 #include <utility> 23 24 namespace llvm { 25 26 class Comdat; 27 class MDNode; 28 class Metadata; 29 30 class GlobalObject : public GlobalValue { 31 protected: 32 GlobalObject(Type *Ty, ValueTy VTy, Use *Ops, unsigned NumOps, 33 LinkageTypes Linkage, const Twine &Name, 34 unsigned AddressSpace = 0) GlobalValue(Ty,VTy,Ops,NumOps,Linkage,Name,AddressSpace)35 : GlobalValue(Ty, VTy, Ops, NumOps, Linkage, Name, AddressSpace), 36 ObjComdat(nullptr) { 37 setGlobalValueSubClassData(0); 38 } 39 40 std::string Section; // Section to emit this into, empty means default 41 Comdat *ObjComdat; 42 enum { 43 LastAlignmentBit = 4, 44 HasMetadataHashEntryBit, 45 46 GlobalObjectBits, 47 }; 48 static const unsigned GlobalObjectSubClassDataBits = 49 GlobalValueSubClassDataBits - GlobalObjectBits; 50 51 private: 52 static const unsigned AlignmentBits = LastAlignmentBit + 1; 53 static const unsigned AlignmentMask = (1 << AlignmentBits) - 1; 54 static const unsigned GlobalObjectMask = (1 << GlobalObjectBits) - 1; 55 56 public: 57 GlobalObject(const GlobalObject &) = delete; 58 getAlignment()59 unsigned getAlignment() const { 60 unsigned Data = getGlobalValueSubClassData(); 61 unsigned AlignmentData = Data & AlignmentMask; 62 return (1u << AlignmentData) >> 1; 63 } 64 void setAlignment(unsigned Align); 65 66 unsigned getGlobalObjectSubClassData() const; 67 void setGlobalObjectSubClassData(unsigned Val); 68 hasSection()69 bool hasSection() const { return !getSection().empty(); } getSection()70 StringRef getSection() const { return Section; } 71 void setSection(StringRef S); 72 hasComdat()73 bool hasComdat() const { return getComdat() != nullptr; } getComdat()74 const Comdat *getComdat() const { return ObjComdat; } getComdat()75 Comdat *getComdat() { return ObjComdat; } setComdat(Comdat * C)76 void setComdat(Comdat *C) { ObjComdat = C; } 77 78 /// Check if this has any metadata. hasMetadata()79 bool hasMetadata() const { return hasMetadataHashEntry(); } 80 81 /// Get the current metadata attachments for the given kind, if any. 82 /// 83 /// These functions require that the function have at most a single attachment 84 /// of the given kind, and return \c nullptr if such an attachment is missing. 85 /// @{ 86 MDNode *getMetadata(unsigned KindID) const; 87 MDNode *getMetadata(StringRef Kind) const; 88 /// @} 89 90 /// Appends all attachments with the given ID to \c MDs in insertion order. 91 /// If the global has no attachments with the given ID, or if ID is invalid, 92 /// leaves MDs unchanged. 93 /// @{ 94 void getMetadata(unsigned KindID, SmallVectorImpl<MDNode *> &MDs) const; 95 void getMetadata(StringRef Kind, SmallVectorImpl<MDNode *> &MDs) const; 96 /// @} 97 98 /// Set a particular kind of metadata attachment. 99 /// 100 /// Sets the given attachment to \c MD, erasing it if \c MD is \c nullptr or 101 /// replacing it if it already exists. 102 /// @{ 103 void setMetadata(unsigned KindID, MDNode *MD); 104 void setMetadata(StringRef Kind, MDNode *MD); 105 /// @} 106 107 /// Add a metadata attachment. 108 /// @{ 109 void addMetadata(unsigned KindID, MDNode &MD); 110 void addMetadata(StringRef Kind, MDNode &MD); 111 /// @} 112 113 /// Appends all attachments for the global to \c MDs, sorting by attachment 114 /// ID. Attachments with the same ID appear in insertion order. 115 void 116 getAllMetadata(SmallVectorImpl<std::pair<unsigned, MDNode *>> &MDs) const; 117 118 /// Erase all metadata attachments with the given kind. 119 void eraseMetadata(unsigned KindID); 120 121 /// Copy metadata from Src, adjusting offsets by Offset. 122 void copyMetadata(const GlobalObject *Src, unsigned Offset); 123 124 void addTypeMetadata(unsigned Offset, Metadata *TypeID); 125 126 void copyAttributesFrom(const GlobalValue *Src) override; 127 128 // Methods for support type inquiry through isa, cast, and dyn_cast: classof(const Value * V)129 static inline bool classof(const Value *V) { 130 return V->getValueID() == Value::FunctionVal || 131 V->getValueID() == Value::GlobalVariableVal; 132 } 133 134 void clearMetadata(); 135 136 private: hasMetadataHashEntry()137 bool hasMetadataHashEntry() const { 138 return getGlobalValueSubClassData() & (1 << HasMetadataHashEntryBit); 139 } setHasMetadataHashEntry(bool HasEntry)140 void setHasMetadataHashEntry(bool HasEntry) { 141 unsigned Mask = 1 << HasMetadataHashEntryBit; 142 setGlobalValueSubClassData((~Mask & getGlobalValueSubClassData()) | 143 (HasEntry ? Mask : 0u)); 144 } 145 }; 146 147 } // end namespace llvm 148 149 #endif // LLVM_IR_GLOBALOBJECT_H 150