//
//===----------------------------------------------------------------------===//
//
-// This class defines the interface that one who 'use's a Value must implement.
+// This class defines the interface that one who uses 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.
+// * Instructions are the largest class of Users.
// * Constants may be users of other constants (think arrays and stuff)
//
//===----------------------------------------------------------------------===//
#ifndef LLVM_USER_H
#define LLVM_USER_H
+#include "llvm/Support/ErrorHandling.h"
#include "llvm/Value.h"
namespace llvm {
+/// OperandTraits - Compile-time customization of
+/// operand-related allocators and accessors
+/// for use of the User class
+template <class>
+struct OperandTraits;
+
class User : public Value {
- User(const User &); // Do not implement
+ User(const User &) LLVM_DELETED_FUNCTION;
+ void *operator new(size_t) LLVM_DELETED_FUNCTION;
+ template <unsigned>
+ friend struct HungoffOperandTraits;
+ virtual void anchor();
protected:
- /// OperandList - This is a pointer to the array of Users for this operand.
+ /// OperandList - This is a pointer to the array of Uses for this User.
/// For nodes of fixed arity (e.g. a binary operator) this array will live
- /// embedded into the derived class. For nodes of variable arity
- /// (e.g. ConstantArrays, CallInst, PHINodes, ReturnInst etc), this memory
- /// will be dynamically allocated and should be destroyed by the classes
- /// virtual dtor.
+ /// prefixed to some derived class instance. For nodes of resizable variable
+ /// arity (e.g. PHINodes, SwitchInst etc.), this memory will be dynamically
+ /// allocated and should be destroyed by the classes' virtual dtor.
Use *OperandList;
/// NumOperands - The number of values used by this User.
///
unsigned NumOperands;
+ void *operator new(size_t s, unsigned Us);
+ User(Type *ty, unsigned vty, Use *OpList, unsigned NumOps)
+ : Value(ty, vty), OperandList(OpList), NumOperands(NumOps) {}
+ Use *allocHungoffUses(unsigned) const;
+ void dropHungoffUses() {
+ Use::zap(OperandList, OperandList + NumOperands, true);
+ OperandList = 0;
+ // Reset NumOperands so User::operator delete() does the right thing.
+ NumOperands = 0;
+ }
+public:
+ ~User() {
+ Use::zap(OperandList, OperandList + NumOperands);
+ }
+ /// operator delete - free memory allocated for User and Use objects
+ void operator delete(void *Usr);
+ /// placement delete - required by std, but never called.
+ void operator delete(void*, unsigned) {
+ llvm_unreachable("Constructor throws?");
+ }
+ /// placement delete - required by std, but never called.
+ void operator delete(void*, unsigned, bool) {
+ llvm_unreachable("Constructor throws?");
+ }
+protected:
+ template <int Idx, typename U> static Use &OpFrom(const U *that) {
+ return Idx < 0
+ ? OperandTraits<U>::op_end(const_cast<U*>(that))[Idx]
+ : OperandTraits<U>::op_begin(const_cast<U*>(that))[Idx];
+ }
+ template <int Idx> Use &Op() {
+ return OpFrom<Idx>(this);
+ }
+ template <int Idx> const Use &Op() const {
+ return OpFrom<Idx>(this);
+ }
public:
- User(const Type *Ty, unsigned vty, Use *OpList, unsigned NumOps)
- : Value(Ty, vty), OperandList(OpList), NumOperands(NumOps) {}
-
Value *getOperand(unsigned i) const {
assert(i < NumOperands && "getOperand() out of range!");
return OperandList[i];
}
void setOperand(unsigned i, Value *Val) {
assert(i < NumOperands && "setOperand() out of range!");
+ assert((!isa<Constant>((const Value*)this) ||
+ isa<GlobalValue>((const Value*)this)) &&
+ "Cannot mutate a constant with setOperand!");
OperandList[i] = Val;
}
+ const Use &getOperandUse(unsigned i) const {
+ assert(i < NumOperands && "getOperandUse() out of range!");
+ return OperandList[i];
+ }
+ Use &getOperandUse(unsigned i) {
+ assert(i < NumOperands && "getOperandUse() out of range!");
+ return OperandList[i];
+ }
+
unsigned getNumOperands() const { return NumOperands; }
// ---------------------------------------------------------------------------
inline op_iterator op_end() { return OperandList+NumOperands; }
inline const_op_iterator op_end() const { return OperandList+NumOperands; }
+ /// Convenience iterator for directly iterating over the Values in the
+ /// OperandList
+ class value_op_iterator : public std::iterator<std::forward_iterator_tag,
+ Value*> {
+ op_iterator OI;
+ public:
+ explicit value_op_iterator(Use *U) : OI(U) {}
+
+ bool operator==(const value_op_iterator &x) const {
+ return OI == x.OI;
+ }
+ bool operator!=(const value_op_iterator &x) const {
+ return !operator==(x);
+ }
+
+ /// Iterator traversal: forward iteration only
+ value_op_iterator &operator++() { // Preincrement
+ ++OI;
+ return *this;
+ }
+ value_op_iterator operator++(int) { // Postincrement
+ value_op_iterator tmp = *this; ++*this; return tmp;
+ }
+
+ /// Retrieve a pointer to the current Value.
+ Value *operator*() const {
+ return *OI;
+ }
+
+ Value *operator->() const { return operator*(); }
+ };
+
+ inline value_op_iterator value_op_begin() {
+ return value_op_iterator(op_begin());
+ }
+ inline value_op_iterator value_op_end() {
+ return value_op_iterator(op_end());
+ }
+
// dropAllReferences() - This function is in charge of "letting go" of all
// objects that this User refers to. 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
+ // references... First all references are dropped, and all use counts go to
+ // zero. Then everything is deleted for real. Note that no operations are
// valid on an object that has "dropped all references", except operator
// delete.
//
void dropAllReferences() {
- Use *OL = OperandList;
- for (unsigned i = 0, e = NumOperands; i != e; ++i)
- OL[i].set(0);
+ for (op_iterator i = op_begin(), e = op_end(); i != e; ++i)
+ i->set(0);
}
/// replaceUsesOfWith - Replaces all references to the "From" definition with
void replaceUsesOfWith(Value *From, Value *To);
// Methods for support type inquiry through isa, cast, and dyn_cast:
- static inline bool classof(const User *) { return true; }
static inline bool classof(const Value *V) {
return isa<Instruction>(V) || isa<Constant>(V);
}
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