llvm-6502/include/llvm/IR/GlobalObject.h
David Majnemer c8a1169c93 IR: Add COMDATs to the IR
This new IR facility allows us to represent the object-file semantic of
a COMDAT group.

COMDATs allow us to tie together sections and make the inclusion of one
dependent on another. This is required to implement features like MS
ABI VFTables and optimizing away certain kinds of initialization in C++.

This functionality is only representable in COFF and ELF, Mach-O has no
similar mechanism.

Differential Revision: http://reviews.llvm.org/D4178

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@211920 91177308-0d34-0410-b5e6-96231b3b80d8
2014-06-27 18:19:56 +00:00

65 lines
2.0 KiB
C++

//===-- llvm/GlobalObject.h - Class to represent a global object *- C++ -*-===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// This represents an independent object. That is, a function or a global
// variable, but not an alias.
//
//===----------------------------------------------------------------------===//
#ifndef LLVM_IR_GLOBALOBJECT_H
#define LLVM_IR_GLOBALOBJECT_H
#include "llvm/IR/Constant.h"
#include "llvm/IR/DerivedTypes.h"
#include "llvm/IR/GlobalValue.h"
namespace llvm {
class Comdat;
class Module;
class GlobalObject : public GlobalValue {
GlobalObject(const GlobalObject &) LLVM_DELETED_FUNCTION;
protected:
GlobalObject(Type *Ty, ValueTy VTy, Use *Ops, unsigned NumOps,
LinkageTypes Linkage, const Twine &Name)
: GlobalValue(Ty, VTy, Ops, NumOps, Linkage, Name), ObjComdat(nullptr) {
setGlobalValueSubClassData(0);
}
std::string Section; // Section to emit this into, empty means default
Comdat *ObjComdat;
public:
unsigned getAlignment() const {
return (1u << getGlobalValueSubClassData()) >> 1;
}
void setAlignment(unsigned Align);
bool hasSection() const { return !StringRef(getSection()).empty(); }
const char *getSection() const { return Section.c_str(); }
void setSection(StringRef S);
bool hasComdat() const { return getComdat() != nullptr; }
const Comdat *getComdat() const { return ObjComdat; }
Comdat *getComdat() { return ObjComdat; }
void setComdat(Comdat *C) { ObjComdat = C; }
void copyAttributesFrom(const GlobalValue *Src) override;
// Methods for support type inquiry through isa, cast, and dyn_cast:
static inline bool classof(const Value *V) {
return V->getValueID() == Value::FunctionVal ||
V->getValueID() == Value::GlobalVariableVal;
}
};
} // End llvm namespace
#endif