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virtualbox/include/iprt/assertcompile.h
Daniel Baumann df1bda4fe9
Adding upstream version 7.0.20-dfsg.
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
2025-06-22 09:56:04 +02:00

263 lines
9.5 KiB
C

/** @file
* IPRT - Compile Time Assertions.
*/
/*
* Copyright (C) 2006-2023 Oracle and/or its affiliates.
*
* This file is part of VirtualBox base platform packages, as
* available from https://www.virtualbox.org.
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation, in version 3 of the
* License.
*
* This program is distributed in the hope that it will be useful, but
* WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, see <https://www.gnu.org/licenses>.
*
* The contents of this file may alternatively be used under the terms
* of the Common Development and Distribution License Version 1.0
* (CDDL), a copy of it is provided in the "COPYING.CDDL" file included
* in the VirtualBox distribution, in which case the provisions of the
* CDDL are applicable instead of those of the GPL.
*
* You may elect to license modified versions of this file under the
* terms and conditions of either the GPL or the CDDL or both.
*
* SPDX-License-Identifier: GPL-3.0-only OR CDDL-1.0
*/
#ifndef IPRT_INCLUDED_assertcompile_h
#define IPRT_INCLUDED_assertcompile_h
#ifndef RT_WITHOUT_PRAGMA_ONCE
# pragma once
#endif
#include <iprt/cdefs.h>
/** @defgroup grp_rt_assert_compile Compile time assertions
* @ingroup grp_rt
*
* These assertions are used to check structure sizes, member/size alignments
* and similar compile time expressions.
*
* @remarks As you might have noticed, the AssertCompile macros don't follow the
* coding guidelines wrt to macros supposedly being all uppercase and
* underscored. For various reasons they don't, and nobody has
* complained yet.
*
* @{
*/
/**
* RTASSERTTYPE is the type the AssertCompile() macro redefines.
* It has no other function and shouldn't be used.
* Visual C++ uses this.
*/
typedef int RTASSERTTYPE[1];
/**
* RTASSERTVAR is the type the AssertCompile() macro redefines.
* It has no other function and shouldn't be used.
*
* GCC and IBM VisualAge C/C++ uses this. GCC doesn't technicaly need this
* global scope one as it declares it for each use, however things get
* complicated in C++ code where most GCC and clang versions gets upset by mixed
* "C" and "C++" versions of the symbol when using inside and outside
* RT_C_DECLS_BEGIN/END. The GCC 3.3.x and 3.4.x versions we use, OTOH will
* always complain about unused RTASSERTVAR for each AssertCompileNS use in a
* function if we declare it globally, so we don't do it for those, but we do
* for 4.x+ to prevent linkage confusion.
*/
#if !defined(__cplusplus) || !defined(__GNUC__)
extern int RTASSERTVAR[1];
#elif RT_GNUC_PREREQ(4, 0) || defined(__clang_major__) /* Not sure when they fixed the global scoping __unused__/whatever problem. */
RT_C_DECLS_BEGIN
extern int RTASSERTVAR[1];
RT_C_DECLS_END
#endif
/** @def RTASSERT_HAVE_STATIC_ASSERT
* Indicates that the compiler implements static_assert(expr, msg).
*/
#ifdef _MSC_VER
# if _MSC_VER >= 1600 && defined(__cplusplus)
# define RTASSERT_HAVE_STATIC_ASSERT
# endif
#endif
#if defined(__GNUC__) && defined(__GXX_EXPERIMENTAL_CXX0X__)
# define RTASSERT_HAVE_STATIC_ASSERT
#endif
#if RT_CLANG_PREREQ(6, 0)
# if __has_feature(cxx_static_assert) || __has_feature(c_static_assert)
# define RTASSERT_HAVE_STATIC_ASSERT
# endif
#endif
#ifdef DOXYGEN_RUNNING
# define RTASSERT_HAVE_STATIC_ASSERT
#endif
/** @def AssertCompileNS
* Asserts that a compile-time expression is true. If it's not break the build.
*
* This differs from AssertCompile in that it accepts some more expressions
* than what C++0x allows - NS = Non-standard.
*
* @param expr Expression which should be true.
*/
#ifdef __GNUC__
# define AssertCompileNS(expr) AssertCompileNS2(expr,RTASSERTVAR)
# define AssertCompileNS2(expr,a_VarName) extern int a_VarName[ 1 ] __attribute__((__unused__)), \
a_VarName[(expr) ? 1 : 0] __attribute__((__unused__))
#elif defined(__IBMC__) || defined(__IBMCPP__)
# define AssertCompileNS(expr) extern int RTASSERTVAR[(expr) ? 1 : 0]
#else
# define AssertCompileNS(expr) typedef int RTASSERTTYPE[(expr) ? 1 : 0]
#endif
/** @def AssertCompile
* Asserts that a C++0x compile-time expression is true. If it's not break the
* build.
* @param expr Expression which should be true.
*/
#ifdef RTASSERT_HAVE_STATIC_ASSERT
# ifdef __cplusplus
# define AssertCompile(expr) static_assert(!!(expr), #expr)
# else
# define AssertCompile(expr) _Static_assert(!!(expr), #expr)
# endif
#else
# define AssertCompile(expr) AssertCompileNS(expr)
#endif
/** @def RTASSERT_OFFSET_OF()
* A offsetof() macro suitable for compile time assertions.
* Both GCC v4 and VisualAge for C++ v3.08 has trouble using RT_OFFSETOF.
*/
#if defined(__GNUC__)
# if __GNUC__ >= 4
# define RTASSERT_OFFSET_OF(a_Type, a_Member) __builtin_offsetof(a_Type, a_Member)
# else
# define RTASSERT_OFFSET_OF(a_Type, a_Member) RT_OFFSETOF(a_Type, a_Member)
# endif
#elif (defined(__IBMC__) || defined(__IBMCPP__)) && defined(RT_OS_OS2)
# define RTASSERT_OFFSET_OF(a_Type, a_Member) __offsetof(a_Type, a_Member)
#elif (defined(__WATCOMC__) && defined(__cplusplus))
# define RTASSERT_OFFSET_OF(a_Type, a_Member) __offsetof(a_Type, a_Member)
#else
# define RTASSERT_OFFSET_OF(a_Type, a_Member) RT_OFFSETOF(a_Type, a_Member)
#endif
/** @def AssertCompileSize
* Asserts a size at compile.
* @param type The type.
* @param size The expected type size.
*/
#define AssertCompileSize(type, size) \
AssertCompile(sizeof(type) == (size))
/** @def AssertCompileSizeAlignment
* Asserts a size alignment at compile.
* @param type The type.
* @param align The size alignment to assert.
*/
#define AssertCompileSizeAlignment(type, align) \
AssertCompile(!(sizeof(type) & ((align) - 1)))
/** @def AssertCompileMemberSize
* Asserts a member offset alignment at compile.
* @param type The type.
* @param member The member.
* @param size The member size to assert.
*/
#define AssertCompileMemberSize(type, member, size) \
AssertCompile(RT_SIZEOFMEMB(type, member) == (size))
/** @def AssertCompileMemberSizeAlignment
* Asserts a member size alignment at compile.
* @param type The type.
* @param member The member.
* @param align The member size alignment to assert.
*/
#define AssertCompileMemberSizeAlignment(type, member, align) \
AssertCompile(!(RT_SIZEOFMEMB(type, member) & ((align) - 1)))
/** @def AssertCompileMemberAlignment
* Asserts a member offset alignment at compile.
* @param type The type.
* @param member The member.
* @param align The member offset alignment to assert.
*/
#define AssertCompileMemberAlignment(type, member, align) \
AssertCompile(!(RTASSERT_OFFSET_OF(type, member) & ((align) - 1)))
/** @def AssertCompileMemberOffset
* Asserts an offset of a structure member at compile.
* @param type The type.
* @param member The member.
* @param off The expected offset.
*/
#define AssertCompileMemberOffset(type, member, off) \
AssertCompile(RTASSERT_OFFSET_OF(type, member) == (off))
/** @def AssertCompile2MemberOffsets
* Asserts that two (sub-structure) members in union have the same offset.
* @param type The type.
* @param member1 The first member.
* @param member2 The second member.
*/
#define AssertCompile2MemberOffsets(type, member1, member2) \
AssertCompile(RTASSERT_OFFSET_OF(type, member1) == RTASSERT_OFFSET_OF(type, member2))
/** @def AssertCompileAdjacentMembers
* Asserts that two structure members are adjacent.
* @param type The type.
* @param member1 The first member.
* @param member2 The second member.
*/
#define AssertCompileAdjacentMembers(type, member1, member2) \
AssertCompile(RTASSERT_OFFSET_OF(type, member1) + RT_SIZEOFMEMB(type, member1) == RTASSERT_OFFSET_OF(type, member2))
/** @def AssertCompileMembersAtSameOffset
* Asserts that members of two different structures are at the same offset.
* @param type1 The first type.
* @param member1 The first member.
* @param type2 The second type.
* @param member2 The second member.
*/
#define AssertCompileMembersAtSameOffset(type1, member1, type2, member2) \
AssertCompile(RTASSERT_OFFSET_OF(type1, member1) == RTASSERT_OFFSET_OF(type2, member2))
/** @def AssertCompileMembersSameSize
* Asserts that members of two different structures have the same size.
* @param type1 The first type.
* @param member1 The first member.
* @param type2 The second type.
* @param member2 The second member.
*/
#define AssertCompileMembersSameSize(type1, member1, type2, member2) \
AssertCompile(RT_SIZEOFMEMB(type1, member1) == RT_SIZEOFMEMB(type2, member2))
/** @def AssertCompileMembersSameSizeAndOffset
* Asserts that members of two different structures have the same size and are
* at the same offset.
* @param type1 The first type.
* @param member1 The first member.
* @param type2 The second type.
* @param member2 The second member.
*/
#define AssertCompileMembersSameSizeAndOffset(type1, member1, type2, member2) \
AssertCompile( RTASSERT_OFFSET_OF(type1, member1) == RTASSERT_OFFSET_OF(type2, member2) \
&& RT_SIZEOFMEMB(type1, member1) == RT_SIZEOFMEMB(type2, member2))
/** @} */
#endif /* !IPRT_INCLUDED_assertcompile_h */