Switch scoped_ptr.h to a compatible google3 implementation.

This is Chromium's base/memory/scoped_ptr.h at r98718, which split off
from the google3 version at a later point than Breakpad's copy. It is a
drop in replacement and the only changes are:
- removal of WARN_UNUSED_RESULT.
- moving it into the google_breakpad namespace.

BUG=534
R=mark@chromium.org

Review URL: https://breakpad.appspot.com/964002

git-svn-id: http://google-breakpad.googlecode.com/svn/trunk@1265 4c0a9323-5329-0410-9bdc-e9ce6186880e
This commit is contained in:
thestig@chromium.org 2013-12-18 19:49:55 +00:00
parent 6199766d99
commit 15873e0016

View file

@ -1,231 +1,285 @@
// (C) Copyright Greg Colvin and Beman Dawes 1998, 1999.
// Copyright (c) 2001, 2002 Peter Dimov
// Copyright 2013 Google Inc. All Rights Reserved.
//
// Permission to copy, use, modify, sell and distribute this software
// is granted provided this copyright notice appears in all copies.
// This software is provided "as is" without express or implied
// warranty, and with no claim as to its suitability for any purpose.
// Redistribution and use in source and binary forms, with or without
// modification, are permitted provided that the following conditions are
// met:
//
// See http://www.boost.org/libs/smart_ptr/scoped_ptr.htm for documentation.
// * Redistributions of source code must retain the above copyright
// notice, this list of conditions and the following disclaimer.
// * Redistributions in binary form must reproduce the above
// copyright notice, this list of conditions and the following disclaimer
// in the documentation and/or other materials provided with the
// distribution.
// * Neither the name of Google Inc. nor the names of its
// contributors may be used to endorse or promote products derived from
// this software without specific prior written permission.
//
// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
// scoped_ptr mimics a built-in pointer except that it guarantees deletion
// of the object pointed to, either on destruction of the scoped_ptr or via
// an explicit reset(). scoped_ptr is a simple solution for simple needs;
// use shared_ptr or std::auto_ptr if your needs are more complex.
// *** NOTE ***
// If your scoped_ptr is a class member of class FOO pointing to a
// forward declared type BAR (as shown below), then you MUST use a non-inlined
// version of the destructor. The destructor of a scoped_ptr (called from
// FOO's destructor) must have a complete definition of BAR in order to
// destroy it. Example:
// Scopers help you manage ownership of a pointer, helping you easily manage the
// a pointer within a scope, and automatically destroying the pointer at the
// end of a scope. There are two main classes you will use, which correspond
// to the operators new/delete and new[]/delete[].
//
// -- foo.h --
// class BAR;
// Example usage (scoped_ptr):
// {
// scoped_ptr<Foo> foo(new Foo("wee"));
// } // foo goes out of scope, releasing the pointer with it.
//
// class FOO {
// public:
// FOO();
// ~FOO(); // Required for sources that instantiate class FOO to compile!
//
// private:
// scoped_ptr<BAR> bar_;
// };
// {
// scoped_ptr<Foo> foo; // No pointer managed.
// foo.reset(new Foo("wee")); // Now a pointer is managed.
// foo.reset(new Foo("wee2")); // Foo("wee") was destroyed.
// foo.reset(new Foo("wee3")); // Foo("wee2") was destroyed.
// foo->Method(); // Foo::Method() called.
// foo.get()->Method(); // Foo::Method() called.
// SomeFunc(foo.release()); // SomeFunc takes ownership, foo no longer
// // manages a pointer.
// foo.reset(new Foo("wee4")); // foo manages a pointer again.
// foo.reset(); // Foo("wee4") destroyed, foo no longer
// // manages a pointer.
// } // foo wasn't managing a pointer, so nothing was destroyed.
//
// -- foo.cc --
// #include "foo.h"
// FOO::~FOO() {} // Empty, but must be non-inlined to FOO's class definition.
// scoped_ptr_malloc added by Google
// When one of these goes out of scope, instead of doing a delete or
// delete[], it calls free(). scoped_ptr_malloc<char> is likely to see
// much more use than any other specializations.
// release() added by Google
// Use this to conditionally transfer ownership of a heap-allocated object
// to the caller, usually on method success.
// Example usage (scoped_array):
// {
// scoped_array<Foo> foo(new Foo[100]);
// foo.get()->Method(); // Foo::Method on the 0th element.
// foo[10].Method(); // Foo::Method on the 10th element.
// }
#ifndef COMMON_SCOPED_PTR_H_
#define COMMON_SCOPED_PTR_H_
#include <cstddef> // for std::ptrdiff_t
#include <assert.h> // for assert
#include <stdlib.h> // for free() decl
// This is an implementation designed to match the anticipated future TR2
// implementation of the scoped_ptr class, and its closely-related brethren,
// scoped_array, scoped_ptr_malloc.
#include <assert.h>
#include <stddef.h>
#include <stdlib.h>
namespace google_breakpad {
template <typename T>
// A scoped_ptr<T> is like a T*, except that the destructor of scoped_ptr<T>
// automatically deletes the pointer it holds (if any).
// That is, scoped_ptr<T> owns the T object that it points to.
// Like a T*, a scoped_ptr<T> may hold either NULL or a pointer to a T object.
// Also like T*, scoped_ptr<T> is thread-compatible, and once you
// dereference it, you get the threadsafety guarantees of T.
//
// The size of a scoped_ptr is small:
// sizeof(scoped_ptr<C>) == sizeof(C*)
template <class C>
class scoped_ptr {
private:
T* ptr;
scoped_ptr(scoped_ptr const &);
scoped_ptr & operator=(scoped_ptr const &);
public:
typedef T element_type;
// The element type
typedef C element_type;
explicit scoped_ptr(T* p = 0): ptr(p) {}
// Constructor. Defaults to initializing with NULL.
// There is no way to create an uninitialized scoped_ptr.
// The input parameter must be allocated with new.
explicit scoped_ptr(C* p = NULL) : ptr_(p) { }
// Destructor. If there is a C object, delete it.
// We don't need to test ptr_ == NULL because C++ does that for us.
~scoped_ptr() {
typedef char type_must_be_complete[sizeof(T)];
delete ptr;
enum { type_must_be_complete = sizeof(C) };
delete ptr_;
}
void reset(T* p = 0) {
typedef char type_must_be_complete[sizeof(T)];
if (ptr != p) {
delete ptr;
ptr = p;
// Reset. Deletes the current owned object, if any.
// Then takes ownership of a new object, if given.
// this->reset(this->get()) works.
void reset(C* p = NULL) {
if (p != ptr_) {
enum { type_must_be_complete = sizeof(C) };
delete ptr_;
ptr_ = p;
}
}
T& operator*() const {
assert(ptr != 0);
return *ptr;
// Accessors to get the owned object.
// operator* and operator-> will assert() if there is no current object.
C& operator*() const {
assert(ptr_ != NULL);
return *ptr_;
}
C* operator->() const {
assert(ptr_ != NULL);
return ptr_;
}
C* get() const { return ptr_; }
// Comparison operators.
// These return whether two scoped_ptr refer to the same object, not just to
// two different but equal objects.
bool operator==(C* p) const { return ptr_ == p; }
bool operator!=(C* p) const { return ptr_ != p; }
// Swap two scoped pointers.
void swap(scoped_ptr& p2) {
C* tmp = ptr_;
ptr_ = p2.ptr_;
p2.ptr_ = tmp;
}
T* operator->() const {
assert(ptr != 0);
return ptr;
}
bool operator==(T* p) const {
return ptr == p;
}
bool operator!=(T* p) const {
return ptr != p;
}
T* get() const {
return ptr;
}
void swap(scoped_ptr & b) {
T* tmp = b.ptr;
b.ptr = ptr;
ptr = tmp;
}
T* release() {
T* tmp = ptr;
ptr = 0;
return tmp;
// Release a pointer.
// The return value is the current pointer held by this object.
// If this object holds a NULL pointer, the return value is NULL.
// After this operation, this object will hold a NULL pointer,
// and will not own the object any more.
C* release() {
C* retVal = ptr_;
ptr_ = NULL;
return retVal;
}
private:
C* ptr_;
// no reason to use these: each scoped_ptr should have its own object
template <typename U> bool operator==(scoped_ptr<U> const& p) const;
template <typename U> bool operator!=(scoped_ptr<U> const& p) const;
// Forbid comparison of scoped_ptr types. If C2 != C, it totally doesn't
// make sense, and if C2 == C, it still doesn't make sense because you should
// never have the same object owned by two different scoped_ptrs.
template <class C2> bool operator==(scoped_ptr<C2> const& p2) const;
template <class C2> bool operator!=(scoped_ptr<C2> const& p2) const;
// Disallow evil constructors
scoped_ptr(const scoped_ptr&);
void operator=(const scoped_ptr&);
};
template<typename T> inline
void swap(scoped_ptr<T>& a, scoped_ptr<T>& b) {
a.swap(b);
// Free functions
template <class C>
void swap(scoped_ptr<C>& p1, scoped_ptr<C>& p2) {
p1.swap(p2);
}
template<typename T> inline
bool operator==(T* p, const scoped_ptr<T>& b) {
return p == b.get();
template <class C>
bool operator==(C* p1, const scoped_ptr<C>& p2) {
return p1 == p2.get();
}
template<typename T> inline
bool operator!=(T* p, const scoped_ptr<T>& b) {
return p != b.get();
template <class C>
bool operator!=(C* p1, const scoped_ptr<C>& p2) {
return p1 != p2.get();
}
// scoped_array extends scoped_ptr to arrays. Deletion of the array pointed to
// is guaranteed, either on destruction of the scoped_array or via an explicit
// reset(). Use shared_array or std::vector if your needs are more complex.
template<typename T>
// scoped_array<C> is like scoped_ptr<C>, except that the caller must allocate
// with new [] and the destructor deletes objects with delete [].
//
// As with scoped_ptr<C>, a scoped_array<C> either points to an object
// or is NULL. A scoped_array<C> owns the object that it points to.
// scoped_array<T> is thread-compatible, and once you index into it,
// the returned objects have only the threadsafety guarantees of T.
//
// Size: sizeof(scoped_array<C>) == sizeof(C*)
template <class C>
class scoped_array {
private:
T* ptr;
scoped_array(scoped_array const &);
scoped_array & operator=(scoped_array const &);
public:
typedef T element_type;
// The element type
typedef C element_type;
explicit scoped_array(T* p = 0) : ptr(p) {}
// Constructor. Defaults to intializing with NULL.
// There is no way to create an uninitialized scoped_array.
// The input parameter must be allocated with new [].
explicit scoped_array(C* p = NULL) : array_(p) { }
// Destructor. If there is a C object, delete it.
// We don't need to test ptr_ == NULL because C++ does that for us.
~scoped_array() {
typedef char type_must_be_complete[sizeof(T)];
delete[] ptr;
enum { type_must_be_complete = sizeof(C) };
delete[] array_;
}
void reset(T* p = 0) {
typedef char type_must_be_complete[sizeof(T)];
if (ptr != p) {
delete [] ptr;
ptr = p;
// Reset. Deletes the current owned object, if any.
// Then takes ownership of a new object, if given.
// this->reset(this->get()) works.
void reset(C* p = NULL) {
if (p != array_) {
enum { type_must_be_complete = sizeof(C) };
delete[] array_;
array_ = p;
}
}
T& operator[](std::ptrdiff_t i) const {
assert(ptr != 0);
// Get one element of the current object.
// Will assert() if there is no current object, or index i is negative.
C& operator[](ptrdiff_t i) const {
assert(i >= 0);
return ptr[i];
assert(array_ != NULL);
return array_[i];
}
bool operator==(T* p) const {
return ptr == p;
// Get a pointer to the zeroth element of the current object.
// If there is no current object, return NULL.
C* get() const {
return array_;
}
bool operator!=(T* p) const {
return ptr != p;
// Comparison operators.
// These return whether two scoped_array refer to the same object, not just to
// two different but equal objects.
bool operator==(C* p) const { return array_ == p; }
bool operator!=(C* p) const { return array_ != p; }
// Swap two scoped arrays.
void swap(scoped_array& p2) {
C* tmp = array_;
array_ = p2.array_;
p2.array_ = tmp;
}
T* get() const {
return ptr;
}
void swap(scoped_array & b) {
T* tmp = b.ptr;
b.ptr = ptr;
ptr = tmp;
}
T* release() {
T* tmp = ptr;
ptr = 0;
return tmp;
// Release an array.
// The return value is the current pointer held by this object.
// If this object holds a NULL pointer, the return value is NULL.
// After this operation, this object will hold a NULL pointer,
// and will not own the object any more.
C* release() {
C* retVal = array_;
array_ = NULL;
return retVal;
}
private:
C* array_;
// no reason to use these: each scoped_array should have its own object
template <typename U> bool operator==(scoped_array<U> const& p) const;
template <typename U> bool operator!=(scoped_array<U> const& p) const;
// Forbid comparison of different scoped_array types.
template <class C2> bool operator==(scoped_array<C2> const& p2) const;
template <class C2> bool operator!=(scoped_array<C2> const& p2) const;
// Disallow evil constructors
scoped_array(const scoped_array&);
void operator=(const scoped_array&);
};
template<class T> inline
void swap(scoped_array<T>& a, scoped_array<T>& b) {
a.swap(b);
// Free functions
template <class C>
void swap(scoped_array<C>& p1, scoped_array<C>& p2) {
p1.swap(p2);
}
template<typename T> inline
bool operator==(T* p, const scoped_array<T>& b) {
return p == b.get();
template <class C>
bool operator==(C* p1, const scoped_array<C>& p2) {
return p1 == p2.get();
}
template<typename T> inline
bool operator!=(T* p, const scoped_array<T>& b) {
return p != b.get();
template <class C>
bool operator!=(C* p1, const scoped_array<C>& p2) {
return p1 != p2.get();
}
// This class wraps the c library function free() in a class that can be
// passed as a template argument to scoped_ptr_malloc below.
class ScopedPtrMallocFree {
@ -238,95 +292,110 @@ class ScopedPtrMallocFree {
// scoped_ptr_malloc<> is similar to scoped_ptr<>, but it accepts a
// second template argument, the functor used to free the object.
template<typename T, typename FreeProc = ScopedPtrMallocFree>
template<class C, class FreeProc = ScopedPtrMallocFree>
class scoped_ptr_malloc {
private:
T* ptr;
scoped_ptr_malloc(scoped_ptr_malloc const &);
scoped_ptr_malloc & operator=(scoped_ptr_malloc const &);
public:
typedef T element_type;
// The element type
typedef C element_type;
explicit scoped_ptr_malloc(T* p = 0): ptr(p) {}
// Constructor. Defaults to initializing with NULL.
// There is no way to create an uninitialized scoped_ptr.
// The input parameter must be allocated with an allocator that matches the
// Free functor. For the default Free functor, this is malloc, calloc, or
// realloc.
explicit scoped_ptr_malloc(C* p = NULL): ptr_(p) {}
// Destructor. If there is a C object, call the Free functor.
~scoped_ptr_malloc() {
typedef char type_must_be_complete[sizeof(T)];
free_((void*) ptr);
reset();
}
void reset(T* p = 0) {
typedef char type_must_be_complete[sizeof(T)];
if (ptr != p) {
free_((void*) ptr);
ptr = p;
// Reset. Calls the Free functor on the current owned object, if any.
// Then takes ownership of a new object, if given.
// this->reset(this->get()) works.
void reset(C* p = NULL) {
if (ptr_ != p) {
FreeProc free_proc;
free_proc(ptr_);
ptr_ = p;
}
}
T& operator*() const {
assert(ptr != 0);
return *ptr;
// Get the current object.
// operator* and operator-> will cause an assert() failure if there is
// no current object.
C& operator*() const {
assert(ptr_ != NULL);
return *ptr_;
}
T* operator->() const {
assert(ptr != 0);
return ptr;
C* operator->() const {
assert(ptr_ != NULL);
return ptr_;
}
bool operator==(T* p) const {
return ptr == p;
C* get() const {
return ptr_;
}
bool operator!=(T* p) const {
return ptr != p;
// Comparison operators.
// These return whether a scoped_ptr_malloc and a plain pointer refer
// to the same object, not just to two different but equal objects.
// For compatibility with the boost-derived implementation, these
// take non-const arguments.
bool operator==(C* p) const {
return ptr_ == p;
}
T* get() const {
return ptr;
bool operator!=(C* p) const {
return ptr_ != p;
}
// Swap two scoped pointers.
void swap(scoped_ptr_malloc & b) {
T* tmp = b.ptr;
b.ptr = ptr;
ptr = tmp;
C* tmp = b.ptr_;
b.ptr_ = ptr_;
ptr_ = tmp;
}
T* release() {
T* tmp = ptr;
ptr = 0;
// Release a pointer.
// The return value is the current pointer held by this object.
// If this object holds a NULL pointer, the return value is NULL.
// After this operation, this object will hold a NULL pointer,
// and will not own the object any more.
C* release() {
C* tmp = ptr_;
ptr_ = NULL;
return tmp;
}
private:
C* ptr_;
// no reason to use these: each scoped_ptr_malloc should have its own object
template <typename U, typename GP>
bool operator==(scoped_ptr_malloc<U, GP> const& p) const;
template <typename U, typename GP>
bool operator!=(scoped_ptr_malloc<U, GP> const& p) const;
template <class C2, class GP>
bool operator==(scoped_ptr_malloc<C2, GP> const& p) const;
template <class C2, class GP>
bool operator!=(scoped_ptr_malloc<C2, GP> const& p) const;
static FreeProc const free_;
// Disallow evil constructors
scoped_ptr_malloc(const scoped_ptr_malloc&);
void operator=(const scoped_ptr_malloc&);
};
template<typename T, typename FP>
FP const scoped_ptr_malloc<T,FP>::free_ = FP();
template<typename T, typename FP> inline
void swap(scoped_ptr_malloc<T,FP>& a, scoped_ptr_malloc<T,FP>& b) {
template<class C, class FP> inline
void swap(scoped_ptr_malloc<C, FP>& a, scoped_ptr_malloc<C, FP>& b) {
a.swap(b);
}
template<typename T, typename FP> inline
bool operator==(T* p, const scoped_ptr_malloc<T,FP>& b) {
template<class C, class FP> inline
bool operator==(C* p, const scoped_ptr_malloc<C, FP>& b) {
return p == b.get();
}
template<typename T, typename FP> inline
bool operator!=(T* p, const scoped_ptr_malloc<T,FP>& b) {
template<class C, class FP> inline
bool operator!=(C* p, const scoped_ptr_malloc<C, FP>& b) {
return p != b.get();
}