Files

124 lines
4.7 KiB
C

/**
* WinPR: Windows Portable Runtime
* Cast macros
*
* Copyright 2024 Armin Novak <anovak@thincast.com>
* Copyright 2024 Thincast Technologies GmbH
*
* 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.
*/
#pragma once
#include <stdint.h>
#include <winpr/assert-api.h>
/**
* @brief C++ safe cast macro
* @since version 3.10.1
*/
#ifdef __cplusplus
#define WINPR_CXX_COMPAT_CAST(t, val) static_cast<t>(val)
#else
#define WINPR_CXX_COMPAT_CAST(t, val) (t)(val)
#endif
#if defined(__GNUC__) || defined(__clang__)
/**
* @brief A macro to do dirty casts. Do not use without a good justification!
* @param ptr The pointer to cast
* @param dstType The data type to cast to
* @return The casted pointer
* @since version 3.9.0
*/
#define WINPR_REINTERPRET_CAST(ptr, srcType, dstType) \
__extension__({ \
union \
{ \
srcType src; \
dstType dst; \
} cnv; \
WINPR_STATIC_ASSERT(sizeof(srcType) == sizeof(dstType)); \
cnv.src = ptr; \
cnv.dst; \
})
/**
* @brief A macro to do dirty casts. Do not use without a good justification!
* @param ptr The pointer to cast
* @param dstType The data type to cast to
* @return The casted pointer
* @since version 3.9.0
*/
#define WINPR_CAST_CONST_PTR_AWAY(ptr, dstType) \
__extension__({ \
union \
{ \
__typeof(ptr) src; \
dstType dst; \
} cnv; \
cnv.src = ptr; \
cnv.dst; \
})
/**
* @brief A macro to do function pointer casts. Do not use without a good justification!
* @param ptr The pointer to cast
* @param dstType The data type to cast to
* @return The casted pointer
* @since version 3.9.0
*/
#define WINPR_FUNC_PTR_CAST(ptr, dstType) \
__extension__({ \
union \
{ \
__typeof(ptr) src; \
dstType dst; \
} cnv; \
WINPR_STATIC_ASSERT(sizeof(dstType) == sizeof(__typeof(ptr))); \
cnv.src = ptr; \
cnv.dst; \
})
#else
#define WINPR_REINTERPRET_CAST(ptr, srcType, dstType) (dstType) ptr
#define WINPR_CAST_CONST_PTR_AWAY(ptr, dstType) (dstType) ptr
#define WINPR_FUNC_PTR_CAST(ptr, dstType) (dstType)(uintptr_t) ptr
#endif
#if defined(__GNUC__) || defined(__clang__)
/**
* @brief A macro to do checked integer casts.
* will check if the value does change by casting to and from the target type and comparing the
* values. will also check if the sign of a value changes during conversion.
*
* @param type the type to cast to
* @param var the integer of unknown type to cast
* @return The casted integer
* @since version 3.10.1
*/
#define WINPR_ASSERTING_INT_CAST(type, ivar) \
__extension__({ \
__typeof(ivar) var = ivar; \
WINPR_ASSERT((var) == \
WINPR_CXX_COMPAT_CAST(__typeof(var), WINPR_CXX_COMPAT_CAST(type, (var)))); \
WINPR_ASSERT((((var) > 0) && (WINPR_CXX_COMPAT_CAST(type, (var)) > 0)) || \
(((var) <= 0) && WINPR_CXX_COMPAT_CAST(type, (var)) <= 0)); \
WINPR_CXX_COMPAT_CAST(type, (var)); \
})
#else
#define WINPR_ASSERTING_INT_CAST(type, var) WINPR_CXX_COMPAT_CAST(type, var)
#endif