-//===-- llvm/Global.h - Class to represent a global variable -----*- C++ -*--=//
+//===-- llvm/GlobalVariable.h - GlobalVariable class ------------*- C++ -*-===//
+//
+// The LLVM Compiler Infrastructure
+//
+// This file was developed by the LLVM research group and is distributed under
+// the University of Illinois Open Source License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
//
// This file contains the declaration of the GlobalVariable class, which
-// represents a single global variable in the VM.
+// represents a single global variable (or constant) in the VM.
//
// Global variables are constant pointers that refer to hunks of space that are
-// allocated by either the VM, or by the linker in a static compiler.
+// allocated by either the VM, or by the linker in a static compiler. A global
+// variable may have an intial value, which is copied into the executables .data
+// area. Global Constants are required to have initializers.
//
//===----------------------------------------------------------------------===//
#ifndef LLVM_GLOBAL_VARIABLE_H
#define LLVM_GLOBAL_VARIABLE_H
-#include "llvm/Value.h"
+#include "llvm/GlobalValue.h"
+
+namespace llvm {
+
class Module;
+class Constant;
+class PointerType;
+template<typename SC> struct ilist_traits;
+template<typename ValueSubClass, typename ItemParentClass, typename SymTabClass,
+ typename SubClass> class SymbolTableListTraits;
-class GlobalVariable : public Value {
- Module *Parent; // The module that contains this method
+class GlobalVariable : public GlobalValue {
+ friend class SymbolTableListTraits<GlobalVariable, Module, Module,
+ ilist_traits<GlobalVariable> >;
+ void setParent(Module *parent);
- friend class ValueHolder<GlobalVariable, Module, Module>;
- void setParent(Module *parent) { Parent = parent; }
+ GlobalVariable *Prev, *Next;
+ void setNext(GlobalVariable *N) { Next = N; }
+ void setPrev(GlobalVariable *N) { Prev = N; }
+
+ bool isConstantGlobal; // Is this a global constant?
+ Use Initializer;
public:
- GlobalVariable(const Type *Ty, const string &Name = "");
- ~GlobalVariable() {}
+ /// GlobalVariable ctor - If a parent module is specified, the global is
+ /// automatically inserted into the end of the specified modules global list.
+ ///
+ GlobalVariable(const Type *Ty, bool isConstant, LinkageTypes Linkage,
+ Constant *Initializer = 0, const std::string &Name = "",
+ Module *Parent = 0);
+
+ /// isExternal - Is this global variable lacking an initializer? If so, the
+ /// global variable is defined in some other translation unit, and is thus
+ /// externally defined here.
+ ///
+ virtual bool isExternal() const { return getNumOperands() == 0; }
- // Specialize setName to handle symbol table majik...
- virtual void setName(const string &name, SymbolTable *ST = 0);
+ /// hasInitializer - Unless a global variable isExternal(), it has an
+ /// initializer. The initializer for the global variable/constant is held by
+ /// Initializer if an initializer is specified.
+ ///
+ inline bool hasInitializer() const { return !isExternal(); }
- inline Module *getParent() { return Parent; }
- inline const Module *getParent() const { return Parent; }
+ /// getInitializer - Return the initializer for this global variable. It is
+ /// illegal to call this method if the global is external, because we cannot
+ /// tell what the value is initialized to!
+ ///
+ inline Constant *getInitializer() const {
+ assert(hasInitializer() && "GV doesn't have initializer!");
+ return reinterpret_cast<Constant*>(Initializer.get());
+ }
+ inline Constant *getInitializer() {
+ assert(hasInitializer() && "GV doesn't have initializer!");
+ return reinterpret_cast<Constant*>(Initializer.get());
+ }
+ inline void setInitializer(Constant *CPV) {
+ if (CPV == 0) {
+ if (hasInitializer()) {
+ Initializer.set(0);
+ NumOperands = 0;
+ }
+ } else {
+ if (!hasInitializer())
+ NumOperands = 1;
+ Initializer.set(CPV);
+ }
+ }
+
+ // getNext/Prev - Return the next or previous global variable in the list.
+ GlobalVariable *getNext() { return Next; }
+ const GlobalVariable *getNext() const { return Next; }
+ GlobalVariable *getPrev() { return Prev; }
+ const GlobalVariable *getPrev() const { return Prev; }
+
+ /// If the value is a global constant, its value is immutable throughout the
+ /// runtime execution of the program. Assigning a value into the constant
+ /// leads to undefined behavior.
+ ///
+ bool isConstant() const { return isConstantGlobal; }
+ void setConstant(bool Value) { isConstantGlobal = Value; }
+
+ /// removeFromParent - This method unlinks 'this' from the containing module,
+ /// but does not delete it.
+ ///
+ void removeFromParent();
+
+ /// eraseFromParent - This method unlinks 'this' from the containing module
+ /// and deletes it.
+ ///
+ void eraseFromParent();
+
+ /// Override Constant's implementation of this method so we can
+ /// replace constant initializers.
+ virtual void replaceUsesOfWithOnConstant(Value *From, Value *To,
+ bool DisableChecking = false);
+
+ virtual void print(std::ostream &OS) const;
+
+ // Methods for support type inquiry through isa, cast, and dyn_cast:
+ static inline bool classof(const GlobalVariable *) { return true; }
+ static inline bool classof(const Value *V) {
+ return V->getValueType() == Value::GlobalVariableVal;
+ }
};
+} // End llvm namespace
+
#endif