Mercurial > gnulib
view tests/null-ptr.h @ 40158:383f7a766b7c
test-framework-sh: Improve maintainability.
* tests/init.sh: Clarify what belongs together. Reorder definitions.
author | Bruno Haible <bruno@clisp.org> |
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date | Sun, 27 Jan 2019 16:55:27 +0100 |
parents | b06060465f09 |
children |
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/* Return a NULL pointer, without letting the compiler know it. Copyright (C) 2017-2019 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/>. */ #include <stdlib.h> /* Return NULL. Usual compilers are not able to infer something about the return value. */ static void * null_ptr (void) { unsigned int x = rand (); unsigned int y = x * x; if (y & 2) return (void *) -1; else return (void *) 0; } /* If you want to know why this always returns NULL, read https://en.wikipedia.org/wiki/Quadratic_residue#Prime_power_modulus . */