#ifndef LLVM_GLOBALVALUE_H
#define LLVM_GLOBALVALUE_H
-#include "llvm/User.h"
+#include "llvm/Constant.h"
+
+namespace llvm {
+
class PointerType;
class Module;
-class GlobalValue : public User {
+class GlobalValue : public Constant {
GlobalValue(const GlobalValue &); // do not implement
public:
enum LinkageTypes {
LinkOnceLinkage, // Keep one copy of named function when linking (inline)
WeakLinkage, // Keep one copy of named function when linking (weak)
AppendingLinkage, // Special purpose, only applies to global arrays
- InternalLinkage // Rename collisions when linking (static functions)
+ InternalLinkage, // Rename collisions when linking (static functions)
+ GhostLinkage // Stand-in functions for streaming fns from BC files
};
protected:
GlobalValue(const Type *Ty, ValueTy vty, LinkageTypes linkage,
const std::string &name = "")
- : User(Ty, vty, name), Linkage(linkage), Parent(0) {}
+ : Constant(Ty, vty, name), Linkage(linkage), Parent(0) { }
LinkageTypes Linkage; // The linkage of this global
Module *Parent;
public:
- ~GlobalValue() {}
+ ~GlobalValue() {
+ removeDeadConstantUsers(); // remove any dead constants using this.
+ }
+
+ /// If the usage is empty (except transitively dead constants), then this
+ /// global value can can be safely deleted since the destructor will
+ /// delete the dead constants as well.
+ /// @brief Determine if the usage of this global value is empty except
+ /// for transitively dead constants.
+ bool use_empty_except_constants();
/// getType - Global values are always pointers.
inline const PointerType *getType() const {
- return (const PointerType*)User::getType();
+ return reinterpret_cast<const PointerType*>(User::getType());
}
bool hasExternalLinkage() const { return Linkage == ExternalLinkage; }
void setLinkage(LinkageTypes LT) { Linkage = LT; }
LinkageTypes getLinkage() const { return Linkage; }
+ /// hasNotBeenReadFromBytecode - If a module provider is being used to lazily
+ /// stream in functions from disk, this method can be used to check to see if
+ /// the function has been read in yet or not. Unless you are working on the
+ /// JIT or something else that streams stuff in lazily, you don't need to
+ /// worry about this.
+ bool hasNotBeenReadFromBytecode() const { return Linkage == GhostLinkage; }
+
+ /// Override from Constant class. No GlobalValue's are null values so this
+ /// always returns false.
+ virtual bool isNullValue() const { return false; }
+
+ /// Override from Constant class.
+ virtual void destroyConstant();
+
/// isExternal - Return true if the primary definition of this global value is
/// outside of the current translation unit...
virtual bool isExternal() const = 0;
inline Module *getParent() { return Parent; }
inline const Module *getParent() const { return Parent; }
+ /// removeDeadConstantUsers - If there are any dead constant users dangling
+ /// off of this global value, remove them. This method is useful for clients
+ /// that want to check to see if a global is unused, but don't want to deal
+ /// with potentially dead constants hanging off of the globals.
+ ///
+ /// This method tries to make the global dead. If it detects a user that
+ /// would prevent it from becoming completely dead, it gives up early,
+ /// potentially leaving some dead constant users around.
+ void removeDeadConstantUsers();
+
// Methods for support type inquiry through isa, cast, and dyn_cast:
static inline bool classof(const GlobalValue *T) { return true; }
static inline bool classof(const Value *V) {
}
};
+} // End llvm namespace
+
#endif