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      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:
     30   GlobalObject(Type *Ty, ValueTy VTy, Use *Ops, unsigned NumOps,
     31                LinkageTypes Linkage, const Twine &Name,
     32                unsigned AddressSpace = 0)
     33       : GlobalValue(Ty, VTy, Ops, NumOps, Linkage, Name, AddressSpace),
     34         ObjComdat(nullptr) {
     35     setGlobalValueSubClassData(0);
     36   }
     37 
     38   std::string Section;     // Section to emit this into, empty means default
     39   Comdat *ObjComdat;
     40   static const unsigned AlignmentBits = 5;
     41   static const unsigned GlobalObjectSubClassDataBits =
     42       GlobalValueSubClassDataBits - AlignmentBits;
     43 
     44 private:
     45   static const unsigned AlignmentMask = (1 << AlignmentBits) - 1;
     46 
     47 public:
     48   unsigned getAlignment() const {
     49     unsigned Data = getGlobalValueSubClassData();
     50     unsigned AlignmentData = Data & AlignmentMask;
     51     return (1u << AlignmentData) >> 1;
     52   }
     53   void setAlignment(unsigned Align);
     54 
     55   unsigned getGlobalObjectSubClassData() const;
     56   void setGlobalObjectSubClassData(unsigned Val);
     57 
     58   bool hasSection() const { return !StringRef(getSection()).empty(); }
     59   const char *getSection() const { return Section.c_str(); }
     60   void setSection(StringRef S);
     61 
     62   bool hasComdat() const { return getComdat() != nullptr; }
     63   const Comdat *getComdat() const { return ObjComdat; }
     64   Comdat *getComdat() { return ObjComdat; }
     65   void setComdat(Comdat *C) { ObjComdat = C; }
     66 
     67   void copyAttributesFrom(const GlobalValue *Src) override;
     68 
     69   // Methods for support type inquiry through isa, cast, and dyn_cast:
     70   static inline bool classof(const Value *V) {
     71     return V->getValueID() == Value::FunctionVal ||
     72            V->getValueID() == Value::GlobalVariableVal;
     73   }
     74 };
     75 
     76 } // End llvm namespace
     77 
     78 #endif
     79