Split GlobalValue into GlobalValue and GlobalObject.

This allows code to statically accept a Function or a GlobalVariable, but
not an alias. This is already a cleanup by itself IMHO, but the main
reason for it is that it gives a lot more confidence that the refactoring to fix
the design of GlobalAlias is correct. That will be a followup patch.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@208716 91177308-0d34-0410-b5e6-96231b3b80d8

include/llvm/IR/GlobalObject.h

@@ -0,0 +1,58 @@
+//===-- 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 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) {
+    setGlobalValueSubClassData(0);
+  }
+
+  std::string Section;     // Section to emit this into, empty means default
+public:
+  unsigned getAlignment() const {
+    return (1u << getGlobalValueSubClassData()) >> 1;
+  }
+  void setAlignment(unsigned Align);
+
+  bool hasSection() const { return !getSection().empty(); }
+  const std::string &getSection() const { return Section; }
+  void setSection(StringRef S);
+
+  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