100 lines
3.5 KiB
C
100 lines
3.5 KiB
C
/* Test of <stddef.h> substitute.
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Copyright (C) 2009-2025 Free Software Foundation, Inc.
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This program is free software: you can redistribute it and/or modify
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it under the terms of the GNU General Public License as published by
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the Free Software Foundation, either version 3 of the License, or
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(at your option) any later version.
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This program is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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GNU General Public License for more details.
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You should have received a copy of the GNU General Public License
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along with this program. If not, see <https://www.gnu.org/licenses/>. */
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/* Written by Eric Blake <ebb9@byu.net>, 2009. */
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#include <config.h>
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#include <stddef.h>
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/* Check that appropriate types are defined. */
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wchar_t a = 'c';
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ptrdiff_t b = 1;
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size_t c = 2;
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max_align_t mat;
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/* Check that NULL can be passed through varargs as a pointer type,
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per POSIX 2008. */
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static_assert (sizeof NULL == sizeof (void *));
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/* Check that offsetof produces integer constants with correct type. */
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struct d
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{
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char e;
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char f;
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};
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/* Solaris 10 has a bug where offsetof is under-parenthesized, and
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cannot be used as an arbitrary expression. However, since it is
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unlikely to bite real code, we ignore that short-coming. */
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/* static_assert (sizeof offsetof (struct d, e) == sizeof (size_t)); */
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static_assert (sizeof (offsetof (struct d, e)) == sizeof (size_t));
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static_assert (offsetof (struct d, f) == 1);
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/* Check max_align_t's alignment. */
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static_assert (alignof (double) <= alignof (max_align_t));
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static_assert (alignof (int) <= alignof (max_align_t));
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static_assert (alignof (long double) <= alignof (max_align_t));
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static_assert (alignof (long int) <= alignof (max_align_t));
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static_assert (alignof (ptrdiff_t) <= alignof (max_align_t));
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static_assert (alignof (size_t) <= alignof (max_align_t));
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static_assert (alignof (wchar_t) <= alignof (max_align_t));
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static_assert (alignof (struct d) <= alignof (max_align_t));
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#if defined __GNUC__ || defined __clang__ || defined __IBM__ALIGNOF__
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static_assert (__alignof__ (double) <= __alignof__ (max_align_t));
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static_assert (__alignof__ (int) <= __alignof__ (max_align_t));
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static_assert (__alignof__ (long double) <= __alignof__ (max_align_t));
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static_assert (__alignof__ (long int) <= __alignof__ (max_align_t));
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static_assert (__alignof__ (ptrdiff_t) <= __alignof__ (max_align_t));
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static_assert (__alignof__ (size_t) <= __alignof__ (max_align_t));
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static_assert (__alignof__ (wchar_t) <= __alignof__ (max_align_t));
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static_assert (__alignof__ (struct d) <= __alignof__ (max_align_t));
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#endif
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int test_unreachable_optimization (int x);
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_Noreturn void test_unreachable_noreturn (void);
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int
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test_unreachable_optimization (int x)
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{
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/* Check that the compiler uses 'unreachable' for optimization.
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This function, when compiled with optimization, should have code
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equivalent to
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return x + 3;
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Use 'objdump --disassemble test-stddef.o' to verify this. */
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if (x < 4)
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unreachable ();
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return (x > 1 ? x + 3 : 2 * x + 10);
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}
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_Noreturn void
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test_unreachable_noreturn (void)
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{
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/* Check that the compiler's data-flow analysis recognizes 'unreachable ()'.
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This function should not elicit a warning. */
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unreachable ();
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}
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#include <limits.h> /* INT_MAX */
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/* offsetof promotes to an unsigned integer if and only if sizes do
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not fit in int. */
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static_assert ((offsetof (struct d, e) < -1) == (INT_MAX < (size_t) -1));
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int
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main (void)
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{
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return 0;
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}
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