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/IR/Constant.h"
19 #include "llvm/IR/DerivedTypes.h"
20 #include "llvm/IR/GlobalValue.h"
21 
22 namespace llvm {
23 class Comdat;
24 class Module;
25 
26 class GlobalObject : public GlobalValue {
27   GlobalObject(const GlobalObject &) = delete;
28 
29 protected:
GlobalObject(PointerType * Ty,ValueTy VTy,Use * Ops,unsigned NumOps,LinkageTypes Linkage,const Twine & Name)30   GlobalObject(PointerType *Ty, ValueTy VTy, Use *Ops, unsigned NumOps,
31                LinkageTypes Linkage, const Twine &Name)
32       : GlobalValue(Ty, VTy, Ops, NumOps, Linkage, Name), ObjComdat(nullptr) {
33     setGlobalValueSubClassData(0);
34   }
35 
36   std::string Section;     // Section to emit this into, empty means default
37   Comdat *ObjComdat;
38   static const unsigned AlignmentBits = 5;
39   static const unsigned GlobalObjectSubClassDataBits =
40       GlobalValueSubClassDataBits - AlignmentBits;
41 
42 private:
43   static const unsigned AlignmentMask = (1 << AlignmentBits) - 1;
44 
45 public:
getAlignment()46   unsigned getAlignment() const {
47     unsigned Data = getGlobalValueSubClassData();
48     unsigned AlignmentData = Data & AlignmentMask;
49     return (1u << AlignmentData) >> 1;
50   }
51   void setAlignment(unsigned Align);
52 
53   unsigned getGlobalObjectSubClassData() const;
54   void setGlobalObjectSubClassData(unsigned Val);
55 
hasSection()56   bool hasSection() const { return !StringRef(getSection()).empty(); }
getSection()57   const char *getSection() const { return Section.c_str(); }
58   void setSection(StringRef S);
59 
hasComdat()60   bool hasComdat() const { return getComdat() != nullptr; }
getComdat()61   const Comdat *getComdat() const { return ObjComdat; }
getComdat()62   Comdat *getComdat() { return ObjComdat; }
setComdat(Comdat * C)63   void setComdat(Comdat *C) { ObjComdat = C; }
64 
65   void copyAttributesFrom(const GlobalValue *Src) override;
66 
67   // Methods for support type inquiry through isa, cast, and dyn_cast:
classof(const Value * V)68   static inline bool classof(const Value *V) {
69     return V->getValueID() == Value::FunctionVal ||
70            V->getValueID() == Value::GlobalVariableVal;
71   }
72 };
73 
74 } // End llvm namespace
75 
76 #endif
77