1 //===-- llvm/Constant.h - Constant class definition -------------*- C++ -*-===//
3 // The LLVM Compiler Infrastructure
5 // This file was developed by the LLVM research group and is distributed under
6 // the University of Illinois Open Source License. See LICENSE.TXT for details.
8 //===----------------------------------------------------------------------===//
10 // This file contains the declaration of the Constant class.
12 //===----------------------------------------------------------------------===//
14 #ifndef LLVM_CONSTANT_H
15 #define LLVM_CONSTANT_H
17 #include "llvm/User.h"
21 class Constant : public User {
22 void operator=(const Constant &); // Do not implement
23 Constant(const Constant &); // Do not implement
25 Constant(const Type *Ty, ValueTy vty, Use *Ops, unsigned NumOps,
26 const std::string& Name = "")
27 : User(Ty, vty, Ops, NumOps, Name) {}
29 void destroyConstantImpl();
31 /// Static constructor to get a '0' constant of arbitrary type...
33 static Constant *getNullValue(const Type *Ty);
35 /// isNullValue - Return true if this is the value that would be returned by
37 virtual bool isNullValue() const = 0;
39 virtual void print(std::ostream &O) const;
41 // Specialize get/setOperand for Constant's as their operands are always
43 Constant *getOperand(unsigned i) {
44 return static_cast<Constant*>(User::getOperand(i));
46 const Constant *getOperand(unsigned i) const {
47 return static_cast<const Constant*>(User::getOperand(i));
49 void setOperand(unsigned i, Constant *C) {
50 User::setOperand(i, C);
53 /// destroyConstant - Called if some element of this constant is no longer
54 /// valid. At this point only other constants may be on the use_list for this
55 /// constant. Any constants on our Use list must also be destroy'd. The
56 /// implementation must be sure to remove the constant from the list of
57 /// available cached constants. Implementations should call
58 /// destroyConstantImpl as the last thing they do, to destroy all users and
60 virtual void destroyConstant() { assert(0 && "Not reached!"); }
62 //// Methods for support type inquiry through isa, cast, and dyn_cast:
63 static inline bool classof(const Constant *) { return true; }
64 static inline bool classof(const GlobalValue *) { return true; }
65 static inline bool classof(const Value *V) {
66 return V->getValueType() >= ConstantFirstVal &&
67 V->getValueType() <= ConstantLastVal;
70 /// replaceUsesOfWithOnConstant - This method is a special form of
71 /// User::replaceUsesOfWith (which does not work on constants) that does work
72 /// on constants. Basically this method goes through the trouble of building
73 /// a new constant that is equivalent to the current one, with all uses of
74 /// From replaced with uses of To. After this construction is completed, all
75 /// of the users of 'this' are replaced to use the new constant, and then
76 /// 'this' is deleted. In general, you should not call this method, instead,
77 /// use Value::replaceAllUsesWith, which automatically dispatches to this
80 virtual void replaceUsesOfWithOnConstant(Value *, Value *, Use *) {
81 // Provide a default implementation for constants (like integers) that
82 // cannot use any other values. This cannot be called at runtime, but needs
83 // to be here to avoid link errors.
84 assert(getNumOperands() == 0 && "replaceUsesOfWithOnConstant must be "
85 "implemented for all constants that have operands!");
86 assert(0 && "Constants that do not have operands cannot be using 'From'!");
89 /// clearAllValueMaps - This method frees all internal memory used by the
90 /// constant subsystem, which can be used in environments where this memory
91 /// is otherwise reported as a leak.
92 static void clearAllValueMaps();
94 /// getStringValue - Turn an LLVM constant pointer that eventually points to a
95 /// global into a string value. Return an empty string if we can't do it.
96 /// Parameter Chop determines if the result is chopped at the first null
99 std::string getStringValue(bool Chop = true, unsigned Offset = 0);
102 } // End llvm namespace