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bc1d4143ae
* tests/null-ptr.h: New file. * tests/test-canonicalize.c: Include null-ptr.h. (null_ptr): Remove function. * tests/test-canonicalize-lgpl.c: Likewise. * tests/test-memmem.c: Likewise. * tests/test-ptsname_r.c: Likewise. * modules/canonicalize-tests (Files): Add tests/null-ptr.h. * modules/canonicalize-lgpl-tests: Likewise. * modules/memmem-tests: Likewise. * modules/ptsname_r-tests: Likewise. Reported by Jim Meyering.
34 lines
1.1 KiB
C
34 lines
1.1 KiB
C
/* Return a NULL pointer, without letting the compiler know it.
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Copyright (C) 2017 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 <http://www.gnu.org/licenses/>. */
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#include <stdlib.h>
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/* Return NULL.
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Usual compilers are not able to infer something about the return value. */
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static void *
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null_ptr (void)
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{
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unsigned int x = rand ();
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unsigned int y = x * x;
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if (y & 2)
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return (void *) -1;
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else
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return (void *) 0;
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}
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/* If you want to know why this always returns NULL, read
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https://en.wikipedia.org/wiki/Quadratic_residue#Prime_power_modulus . */
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