-//===-- llvm/Constant.h - Constant class definition --------------*- C++ -*--=//
+//===-- 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.
//
#include "llvm/User.h"
+namespace llvm {
+
class Constant : public User {
protected:
inline Constant(const Type *Ty) : User(Ty, Value::ConstantVal) {}
void destroyConstantImpl();
public:
- // Specialize setName to handle symbol table majik...
+ // 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 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.
+ /// 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
+ /// 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.
- //
+ /// 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:
+ //// 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.
- virtual unsigned mutateReferences(Value* OldV, Value *NewV) { return 0; }
+ unsigned mutateReferences(Value* OldV, Value *NewV);
// END WARNING!!
};
+} // End llvm namespace
+
#endif