mirror of
https://github.com/chromium/crashpad.git
synced 2024-12-28 15:50:26 +08:00
b666bcbe98
HandleToInt() and IntToHandle() use int, a signed type, for the 32-bit integer representation of HANDLE values. For opaque values, an unsigned type would normally be used, but in this case, signed was chosen for sign extension to work correctly. INVALID_HANDLE_VALUE is defined as ((HANDLE)(LONG_PTR)-1), and this needs to round-trip through the chosen integer representation back to the same HANDLE value. Sign extension is also recommended by https://msdn.microsoft.com/en-us/library/windows/desktop/aa384203. As suggested in https://codereview.chromium.org/1422503015/diff/1/util/win/handle.cc#newcode24 R=scottmg@chromium.org Review URL: https://codereview.chromium.org/1422023010 .
66 lines
2.5 KiB
C++
66 lines
2.5 KiB
C++
// Copyright 2015 The Crashpad Authors. All rights reserved.
|
||
//
|
||
// Licensed under the Apache License, Version 2.0 (the "License");
|
||
// you may not use this file except in compliance with the License.
|
||
// You may obtain a copy of the License at
|
||
//
|
||
// http://www.apache.org/licenses/LICENSE-2.0
|
||
//
|
||
// Unless required by applicable law or agreed to in writing, software
|
||
// distributed under the License is distributed on an "AS IS" BASIS,
|
||
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
|
||
// See the License for the specific language governing permissions and
|
||
// limitations under the License.
|
||
|
||
#ifndef CRASHPAD_UTIL_WIN_HANDLE_TO_INT_H_
|
||
#define CRASHPAD_UTIL_WIN_HANDLE_TO_INT_H_
|
||
|
||
#include <windows.h>
|
||
|
||
namespace crashpad {
|
||
|
||
//! \brief Converts a `HANDLE` to an `int`.
|
||
//!
|
||
//! `HANDLE` is a `typedef` for `void *`, but kernel `HANDLE` values aren’t
|
||
//! pointers to anything. Only 32 bits of kernel `HANDLE`s are significant, even
|
||
//! in 64-bit processes on 64-bit operating systems. See <a
|
||
//! href="https://msdn.microsoft.com/en-us/library/windows/desktop/aa384203">Interprocess
|
||
//! Communication Between 32-bit and 64-bit Applications</a>.
|
||
//!
|
||
//! This function safely converts a kernel `HANDLE` to an `int` similarly to a
|
||
//! cast operation. It checks that the operation can be performed safely, and
|
||
//! aborts execution if it cannot.
|
||
//!
|
||
//! \param[in] handle The kernel `HANDLE` to convert.
|
||
//!
|
||
//! \return An equivalent `int`, truncated (if necessary) from \a handle. If
|
||
//! truncation would have resulted in an `int` that could not be converted
|
||
//! back to \a handle, aborts execution.
|
||
//!
|
||
//! \sa IntToHandle()
|
||
int HandleToInt(HANDLE handle);
|
||
|
||
//! \brief Converts an `int` to an `HANDLE`.
|
||
//!
|
||
//! `HANDLE` is a `typedef` for `void *`, but kernel `HANDLE` values aren’t
|
||
//! pointers to anything. Only 32 bits of kernel `HANDLE`s are significant, even
|
||
//! in 64-bit processes on 64-bit operating systems. See <a
|
||
//! href="https://msdn.microsoft.com/en-us/library/windows/desktop/aa384203">Interprocess
|
||
//! Communication Between 32-bit and 64-bit Applications</a>.
|
||
//!
|
||
//! This function safely convert an `int` to a kernel `HANDLE` similarly to a
|
||
//! cast operation.
|
||
//!
|
||
//! \param[in] handle_int The `int` to convert. This must have been produced by
|
||
//! HandleToInt(), possibly in a different process.
|
||
//!
|
||
//! \return An equivalent kernel `HANDLE`, sign-extended (if necessary) from \a
|
||
//! handle_int.
|
||
//!
|
||
//! \sa HandleToInt()
|
||
HANDLE IntToHandle(int handle_int);
|
||
|
||
} // namespace crashpad
|
||
|
||
#endif // CRASHPAD_UTIL_WIN_HANDLE_TO_INT_H_
|