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llvm-6502/include/llvm/ADT/OwningPtr.h
David Blaikie 453f4f0130 Use only explicit bool conversion operators
BitVector/SmallBitVector::reference::operator bool remain implicit since
they model more exactly a bool, rather than something else that can be
boolean tested.

The most common (non-buggy) case are where such objects are used as
return expressions in bool-returning functions or as boolean function
arguments. In those cases I've used (& added if necessary) a named
function to provide the equivalent (or sometimes negative, depending on
convenient wording) test.

One behavior change (YAMLParser) was made, though no test case is
included as I'm not sure how to reach that code path. Essentially any
comparison of llvm::yaml::document_iterators would be invalid if neither
iterator was at the end.

This helped uncover a couple of bugs in Clang - test cases provided for
those in a separate commit along with similar changes to `operator bool`
instances in Clang.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@181868 91177308-0d34-0410-b5e6-96231b3b80d8
2013-05-15 07:36:59 +00:00

154 lines
3.9 KiB
C++

//===- llvm/ADT/OwningPtr.h - Smart ptr that owns the pointee ---*- C++ -*-===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// This file defines and implements the OwningPtr class.
//
//===----------------------------------------------------------------------===//
#ifndef LLVM_ADT_OWNINGPTR_H
#define LLVM_ADT_OWNINGPTR_H
#include "llvm/Support/Compiler.h"
#include <cassert>
#include <cstddef>
namespace llvm {
/// OwningPtr smart pointer - OwningPtr mimics a built-in pointer except that it
/// guarantees deletion of the object pointed to, either on destruction of the
/// OwningPtr or via an explicit reset(). Once created, ownership of the
/// pointee object can be taken away from OwningPtr by using the take method.
template<class T>
class OwningPtr {
OwningPtr(OwningPtr const &) LLVM_DELETED_FUNCTION;
OwningPtr &operator=(OwningPtr const &) LLVM_DELETED_FUNCTION;
T *Ptr;
public:
explicit OwningPtr(T *P = 0) : Ptr(P) {}
#if LLVM_HAS_RVALUE_REFERENCES
OwningPtr(OwningPtr &&Other) : Ptr(Other.take()) {}
OwningPtr &operator=(OwningPtr &&Other) {
reset(Other.take());
return *this;
}
#endif
~OwningPtr() {
delete Ptr;
}
/// reset - Change the current pointee to the specified pointer. Note that
/// calling this with any pointer (including a null pointer) deletes the
/// current pointer.
void reset(T *P = 0) {
if (P == Ptr) return;
T *Tmp = Ptr;
Ptr = P;
delete Tmp;
}
/// take - Reset the owning pointer to null and return its pointer. This does
/// not delete the pointer before returning it.
T *take() {
T *Tmp = Ptr;
Ptr = 0;
return Tmp;
}
T &operator*() const {
assert(Ptr && "Cannot dereference null pointer");
return *Ptr;
}
T *operator->() const { return Ptr; }
T *get() const { return Ptr; }
LLVM_EXPLICIT operator bool() const { return Ptr != 0; }
bool operator!() const { return Ptr == 0; }
bool isValid() const { return Ptr != 0; }
void swap(OwningPtr &RHS) {
T *Tmp = RHS.Ptr;
RHS.Ptr = Ptr;
Ptr = Tmp;
}
};
template<class T>
inline void swap(OwningPtr<T> &a, OwningPtr<T> &b) {
a.swap(b);
}
/// OwningArrayPtr smart pointer - OwningArrayPtr provides the same
/// functionality as OwningPtr, except that it works for array types.
template<class T>
class OwningArrayPtr {
OwningArrayPtr(OwningArrayPtr const &) LLVM_DELETED_FUNCTION;
OwningArrayPtr &operator=(OwningArrayPtr const &) LLVM_DELETED_FUNCTION;
T *Ptr;
public:
explicit OwningArrayPtr(T *P = 0) : Ptr(P) {}
#if LLVM_HAS_RVALUE_REFERENCES
OwningArrayPtr(OwningArrayPtr &&Other) : Ptr(Other.take()) {}
OwningArrayPtr &operator=(OwningArrayPtr &&Other) {
reset(Other.take());
return *this;
}
#endif
~OwningArrayPtr() {
delete [] Ptr;
}
/// reset - Change the current pointee to the specified pointer. Note that
/// calling this with any pointer (including a null pointer) deletes the
/// current pointer.
void reset(T *P = 0) {
if (P == Ptr) return;
T *Tmp = Ptr;
Ptr = P;
delete [] Tmp;
}
/// take - Reset the owning pointer to null and return its pointer. This does
/// not delete the pointer before returning it.
T *take() {
T *Tmp = Ptr;
Ptr = 0;
return Tmp;
}
T &operator[](std::ptrdiff_t i) const {
assert(Ptr && "Cannot dereference null pointer");
return Ptr[i];
}
T *get() const { return Ptr; }
LLVM_EXPLICIT operator bool() const { return Ptr != 0; }
bool operator!() const { return Ptr == 0; }
void swap(OwningArrayPtr &RHS) {
T *Tmp = RHS.Ptr;
RHS.Ptr = Ptr;
Ptr = Tmp;
}
};
template<class T>
inline void swap(OwningArrayPtr<T> &a, OwningArrayPtr<T> &b) {
a.swap(b);
}
} // end namespace llvm
#endif