1 //===-- llvm/Constant.h - Constant class definition --------------*- C++ -*--=//
3 // This file contains the declaration of the Constant class.
5 //===----------------------------------------------------------------------===//
7 #ifndef LLVM_CONSTANT_H
8 #define LLVM_CONSTANT_H
10 #include "llvm/User.h"
12 class Constant : public User {
14 inline Constant(const Type *Ty) : User(Ty, Value::ConstantVal) {}
17 void destroyConstantImpl();
19 // Specialize setName to handle symbol table majik...
20 virtual void setName(const std::string &name, SymbolTable *ST = 0);
22 // Static constructor to get a '0' constant of arbitrary type...
23 static Constant *getNullValue(const Type *Ty);
25 // isNullValue - Return true if this is the value that would be returned by
27 virtual bool isNullValue() const = 0;
29 virtual void print(std::ostream &O) const;
31 // isConstantExpr - Return true if this is a ConstantExpr
32 virtual bool isConstantExpr() const { return false; }
35 // destroyConstant - Called if some element of this constant is no longer
36 // valid. At this point only other constants may be on the use_list for this
37 // constant. Any constants on our Use list must also be destroy'd. The
38 // implementation must be sure to remove the constant from the list of
39 // available cached constants. Implementations should call
40 // destroyConstantImpl as the last thing they do, to destroy all users and
43 // Note that this call is only valid on non-primitive constants: You cannot
44 // destroy an integer constant for example. This API is used to delete
45 // constants that have ConstantPointerRef's embeded in them when the module is
46 // deleted, and it is used by GlobalDCE to remove ConstantPointerRefs that are
47 // unneeded, allowing globals to be DCE'd.
49 virtual void destroyConstant() { assert(0 && "Not reached!"); }
52 // Methods for support type inquiry through isa, cast, and dyn_cast:
53 static inline bool classof(const Constant *) { return true; }
54 static inline bool classof(const Value *V) {
55 return V->getValueType() == Value::ConstantVal;
58 // WARNING: Only to be used by Bytecode & Assembly Parsers! USER CODE SHOULD
60 // Returns the number of uses of OldV that were replaced.
61 virtual unsigned mutateReferences(Value* OldV, Value *NewV) { return 0; }