1 //===-- llvm/GlobalObject.h - Class to represent global objects -*- 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 //===----------------------------------------------------------------------===//
10 // This represents an independent object. That is, a function or a global
11 // variable, but not an alias.
13 //===----------------------------------------------------------------------===//
15 #ifndef LLVM_IR_GLOBALOBJECT_H
16 #define LLVM_IR_GLOBALOBJECT_H
18 #include "llvm/ADT/StringRef.h"
19 #include "llvm/IR/GlobalValue.h"
20 #include "llvm/IR/Value.h"
30 class GlobalObject : public GlobalValue {
32 GlobalObject(Type *Ty, ValueTy VTy, Use *Ops, unsigned NumOps,
33 LinkageTypes Linkage, const Twine &Name,
34 unsigned AddressSpace = 0)
35 : GlobalValue(Ty, VTy, Ops, NumOps, Linkage, Name, AddressSpace),
37 setGlobalValueSubClassData(0);
43 HasMetadataHashEntryBit,
44 HasSectionHashEntryBit,
48 static const unsigned GlobalObjectSubClassDataBits =
49 GlobalValueSubClassDataBits - GlobalObjectBits;
52 static const unsigned AlignmentBits = LastAlignmentBit + 1;
53 static const unsigned AlignmentMask = (1 << AlignmentBits) - 1;
54 static const unsigned GlobalObjectMask = (1 << GlobalObjectBits) - 1;
57 GlobalObject(const GlobalObject &) = delete;
59 unsigned getAlignment() const {
60 unsigned Data = getGlobalValueSubClassData();
61 unsigned AlignmentData = Data & AlignmentMask;
62 return (1u << AlignmentData) >> 1;
64 void setAlignment(unsigned Align);
66 unsigned getGlobalObjectSubClassData() const {
67 unsigned ValueData = getGlobalValueSubClassData();
68 return ValueData >> GlobalObjectBits;
71 void setGlobalObjectSubClassData(unsigned Val) {
72 unsigned OldData = getGlobalValueSubClassData();
73 setGlobalValueSubClassData((OldData & GlobalObjectMask) |
74 (Val << GlobalObjectBits));
75 assert(getGlobalObjectSubClassData() == Val && "representation error");
78 /// Check if this global has a custom object file section.
80 /// This is more efficient than calling getSection() and checking for an empty
82 bool hasSection() const {
83 return getGlobalValueSubClassData() & (1 << HasSectionHashEntryBit);
86 /// Get the custom section of this global if it has one.
88 /// If this global does not have a custom section, this will be empty and the
89 /// default object file section (.text, .data, etc) will be used.
90 StringRef getSection() const {
91 return hasSection() ? getSectionImpl() : StringRef();
94 /// Change the section for this global.
96 /// Setting the section to the empty string tells LLVM to choose an
97 /// appropriate default object file section.
98 void setSection(StringRef S);
100 bool hasComdat() const { return getComdat() != nullptr; }
101 const Comdat *getComdat() const { return ObjComdat; }
102 Comdat *getComdat() { return ObjComdat; }
103 void setComdat(Comdat *C) { ObjComdat = C; }
105 /// Check if this has any metadata.
106 bool hasMetadata() const { return hasMetadataHashEntry(); }
108 /// Get the current metadata attachments for the given kind, if any.
110 /// These functions require that the function have at most a single attachment
111 /// of the given kind, and return \c nullptr if such an attachment is missing.
113 MDNode *getMetadata(unsigned KindID) const;
114 MDNode *getMetadata(StringRef Kind) const;
117 /// Appends all attachments with the given ID to \c MDs in insertion order.
118 /// If the global has no attachments with the given ID, or if ID is invalid,
119 /// leaves MDs unchanged.
121 void getMetadata(unsigned KindID, SmallVectorImpl<MDNode *> &MDs) const;
122 void getMetadata(StringRef Kind, SmallVectorImpl<MDNode *> &MDs) const;
125 /// Set a particular kind of metadata attachment.
127 /// Sets the given attachment to \c MD, erasing it if \c MD is \c nullptr or
128 /// replacing it if it already exists.
130 void setMetadata(unsigned KindID, MDNode *MD);
131 void setMetadata(StringRef Kind, MDNode *MD);
134 /// Add a metadata attachment.
136 void addMetadata(unsigned KindID, MDNode &MD);
137 void addMetadata(StringRef Kind, MDNode &MD);
140 /// Appends all attachments for the global to \c MDs, sorting by attachment
141 /// ID. Attachments with the same ID appear in insertion order.
143 getAllMetadata(SmallVectorImpl<std::pair<unsigned, MDNode *>> &MDs) const;
145 /// Erase all metadata attachments with the given kind.
146 void eraseMetadata(unsigned KindID);
148 /// Copy metadata from Src, adjusting offsets by Offset.
149 void copyMetadata(const GlobalObject *Src, unsigned Offset);
151 void addTypeMetadata(unsigned Offset, Metadata *TypeID);
154 void copyAttributesFrom(const GlobalObject *Src);
157 // Methods for support type inquiry through isa, cast, and dyn_cast:
158 static bool classof(const Value *V) {
159 return V->getValueID() == Value::FunctionVal ||
160 V->getValueID() == Value::GlobalVariableVal;
163 void clearMetadata();
166 void setGlobalObjectFlag(unsigned Bit, bool Val) {
167 unsigned Mask = 1 << Bit;
168 setGlobalValueSubClassData((~Mask & getGlobalValueSubClassData()) |
172 bool hasMetadataHashEntry() const {
173 return getGlobalValueSubClassData() & (1 << HasMetadataHashEntryBit);
175 void setHasMetadataHashEntry(bool HasEntry) {
176 setGlobalObjectFlag(HasMetadataHashEntryBit, HasEntry);
179 StringRef getSectionImpl() const;
182 } // end namespace llvm
184 #endif // LLVM_IR_GLOBALOBJECT_H