| //===-- llvm/Constant.h - Constant class definition -------------*- 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 Constant class. |
| // |
| //===----------------------------------------------------------------------===// |
| |
| #ifndef LLVM_CONSTANT_H |
| #define LLVM_CONSTANT_H |
| |
| #include "llvm/User.h" |
| |
| class Constant : public User { |
| protected: |
| inline Constant(const Type *Ty) : User(Ty, Value::ConstantVal) {} |
| ~Constant() {} |
| |
| void destroyConstantImpl(); |
| public: |
| // setName - Specialize setName to handle symbol table majik... |
| virtual void setName(const std::string &name, SymbolTable *ST = 0); |
| |
| /// Static constructor to get a '0' constant of arbitrary type... |
| /// |
| static Constant *getNullValue(const Type *Ty); |
| |
| /// isNullValue - Return true if this is the value that would be returned by |
| /// getNullValue. |
| virtual bool isNullValue() const = 0; |
| |
| virtual void print(std::ostream &O) const; |
| |
| /// isConstantExpr - Return true if this is a ConstantExpr |
| /// |
| virtual bool isConstantExpr() const { return false; } |
| |
| |
| /// destroyConstant - Called if some element of this constant is no longer |
| /// valid. At this point only other constants may be on the use_list for this |
| /// constant. Any constants on our Use list must also be destroy'd. The |
| /// implementation must be sure to remove the constant from the list of |
| /// available cached constants. Implementations should call |
| /// destroyConstantImpl as the last thing they do, to destroy all users and |
| /// delete this. |
| /// |
| /// Note that this call is only valid on non-primitive constants: You cannot |
| /// destroy an integer constant for example. This API is used to delete |
| /// constants that have ConstantPointerRef's embeded in them when the module |
| /// is deleted, and it is used by GlobalDCE to remove ConstantPointerRefs that |
| /// are unneeded, allowing globals to be DCE'd. |
| /// |
| virtual void destroyConstant() { assert(0 && "Not reached!"); } |
| |
| |
| //// Methods for support type inquiry through isa, cast, and dyn_cast: |
| static inline bool classof(const Constant *) { return true; } |
| static inline bool classof(const Value *V) { |
| return V->getValueType() == Value::ConstantVal; |
| } |
| |
| /// replaceUsesOfWithOnConstant - This method is a special form of |
| /// User::replaceUsesOfWith (which does not work on constants) that does work |
| /// on constants. Basically this method goes through the trouble of building |
| /// a new constant that is equivalent to the current one, with all uses of |
| /// From replaced with uses of To. After this construction is completed, all |
| /// of the users of 'this' are replaced to use the new constant, and then |
| /// 'this' is deleted. In general, you should not call this method, instead, |
| /// use Value::replaceAllUsesWith, which automatically dispatches to this |
| /// method as needed. |
| /// |
| virtual void replaceUsesOfWithOnConstant(Value *From, Value *To, |
| bool DisableChecking = false) { |
| // Provide a default implementation for constants (like integers) that |
| // cannot use any other values. This cannot be called at runtime, but needs |
| // to be here to avoid link errors. |
| assert(getNumOperands() == 0 && "replaceUsesOfWithOnConstant must be " |
| "implemented for all constants that have operands!"); |
| assert(0 && "Constants that do not have operands cannot be using 'From'!"); |
| } |
| |
| // WARNING: Only to be used by Bytecode & Assembly Parsers! USER CODE SHOULD |
| // NOT USE THIS!! |
| // Returns the number of uses of OldV that were replaced. |
| unsigned mutateReferences(Value* OldV, Value *NewV); |
| // END WARNING!! |
| }; |
| |
| #endif |