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/* Test of <stddef.h> substitute.
Copyright (C) 2009-2025 Free Software Foundation, Inc.
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, either version 3 of the License, or
(at your option) any later version.
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/>. */
/* Written by Eric Blake <ebb9@byu.net>, 2009. */
#include <config.h>
#include <stddef.h>
/* Check that appropriate types are defined. */
wchar_t a = 'c';
ptrdiff_t b = 1;
size_t c = 2;
#if !defined __cplusplus || __cplusplus >= 201103
max_align_t mat;
#endif
#if !(defined __cplusplus && defined _MSC_VER)
/* Check that NULL can be passed through varargs as a pointer type,
per POSIX 2008. */
static_assert (sizeof NULL == sizeof (void *));
#endif
/* Check that offsetof produces integer constants with correct type. */
struct d
{
char e;
char f;
};
/* Solaris 10 has a bug where offsetof is under-parenthesized, and
cannot be used as an arbitrary expression. However, since it is
unlikely to bite real code, we ignore that short-coming. */
/* static_assert (sizeof offsetof (struct d, e) == sizeof (size_t)); */
static_assert (sizeof (offsetof (struct d, e)) == sizeof (size_t));
static_assert (offsetof (struct d, f) == 1);
#if !defined __cplusplus || __cplusplus >= 201103
/* Check max_align_t's alignment. */
static_assert (alignof (double) <= alignof (max_align_t));
static_assert (alignof (int) <= alignof (max_align_t));
static_assert (alignof (long double) <= alignof (max_align_t));
static_assert (alignof (long int) <= alignof (max_align_t));
static_assert (alignof (ptrdiff_t) <= alignof (max_align_t));
static_assert (alignof (size_t) <= alignof (max_align_t));
static_assert (alignof (wchar_t) <= alignof (max_align_t));
static_assert (alignof (struct d) <= alignof (max_align_t));
# if defined __GNUC__ || defined __clang__ || defined __IBM__ALIGNOF__
static_assert (__alignof__ (double) <= __alignof__ (max_align_t));
static_assert (__alignof__ (int) <= __alignof__ (max_align_t));
static_assert (__alignof__ (long double) <= __alignof__ (max_align_t));
static_assert (__alignof__ (long int) <= __alignof__ (max_align_t));
static_assert (__alignof__ (ptrdiff_t) <= __alignof__ (max_align_t));
static_assert (__alignof__ (size_t) <= __alignof__ (max_align_t));
static_assert (__alignof__ (wchar_t) <= __alignof__ (max_align_t));
static_assert (__alignof__ (struct d) <= __alignof__ (max_align_t));
# endif
#endif
#ifndef __cplusplus
/* Test 'unreachable'. */
int test_unreachable_optimization (int x);
_Noreturn void test_unreachable_noreturn (void);
int
test_unreachable_optimization (int x)
{
/* Check that the compiler uses 'unreachable' for optimization.
This function, when compiled with optimization, should have code
equivalent to
return x + 3;
Use 'objdump --disassemble test-stddef.o' to verify this. */
if (x < 4)
unreachable ();
return (x > 1 ? x + 3 : 2 * x + 10);
}
_Noreturn void
test_unreachable_noreturn (void)
{
/* Check that the compiler's data-flow analysis recognizes 'unreachable ()'.
This function should not elicit a warning. */
unreachable ();
}
#endif
/* Test 'gl_unreachable'. */
int test_gl_unreachable_optimization (int x);
_Noreturn void test_gl_unreachable_noreturn (void);
int
test_gl_unreachable_optimization (int x)
{
/* Check that the compiler uses 'gl_unreachable' for optimization.
This function, when compiled with optimization, should have code
equivalent to
return x + 3;
Use 'objdump --disassemble test-stddef.o' to verify this. */
if (x < 4)
gl_unreachable ();
return (x > 1 ? x + 3 : 2 * x + 10);
}
_Noreturn void
test_gl_unreachable_noreturn (void)
{
/* Check that the compiler's data-flow analysis recognizes
'gl_unreachable ()'. This function should not elicit a warning. */
gl_unreachable ();
}
#include <limits.h> /* INT_MAX */
/* offsetof promotes to an unsigned integer if and only if sizes do
not fit in int. */
static_assert ((offsetof (struct d, e) < -1) == (INT_MAX < (size_t) -1));
int
main (void)
{
return 0;
}
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