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+//===-- llvm/User.h - User class definition ----------------------*- C++ -*--=//
+//
+// This class defines the interface that one who 'use's a Value must implement.
+// Each instance of the Value class keeps track of what User's have handles
+// to it.
+//
+// * Instructions are the largest class of User's.
+// * Constants may be users of other constants (think arrays and stuff)
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_USER_H
+#define LLVM_USER_H
+
+#include "llvm/Value.h"
+
+class User : public Value {
+ User(const User &); // Do not implement
+public:
+ User(const Type *Ty, ValueTy vty, const string &name = "");
+ virtual ~User() {}
+
+ // if i > the number of operands, then getOperand() returns 0, and setOperand
+ // returns false. setOperand() may also return false if the operand is of
+ // the wrong type.
+ //
+ virtual Value *getOperand(unsigned i) = 0;
+ virtual const Value *getOperand(unsigned i) const = 0;
+ virtual bool setOperand(unsigned i, Value *Val) = 0;
+
+ // dropAllReferences() - This virtual function should be overridden to "let
+ // go" of all references that this user is maintaining. This allows one to
+ // 'delete' a whole class at a time, even though there may be circular
+ // references... first all references are dropped, and all use counts go to
+ // zero. Then everything is delete'd for real. Note that no operations are
+ // valid on an object that has "dropped all references", except operator
+ // delete.
+ //
+ virtual void dropAllReferences() = 0;
+
+ // replaceUsesOfWith - Replaces all references to the "From" definition with
+ // references to the "To" definition. (defined in Value.cpp)
+ //
+ void replaceUsesOfWith(Value *From, Value *To);
+};
+
+#endif