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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-19 16:58:41 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-19 16:58:41 +0000 |
commit | e1908ae95dd4c9d19ee4dfabfc8bf8a7f85943fe (patch) | |
tree | f5cc731bedcac0fb7fe14d952e4581e749f8bb87 /gnulib-tests/null-ptr.h | |
parent | Initial commit. (diff) | |
download | coreutils-e1908ae95dd4c9d19ee4dfabfc8bf8a7f85943fe.tar.xz coreutils-e1908ae95dd4c9d19ee4dfabfc8bf8a7f85943fe.zip |
Adding upstream version 9.4.upstream/9.4upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'gnulib-tests/null-ptr.h')
-rw-r--r-- | gnulib-tests/null-ptr.h | 33 |
1 files changed, 33 insertions, 0 deletions
diff --git a/gnulib-tests/null-ptr.h b/gnulib-tests/null-ptr.h new file mode 100644 index 0000000..e951b61 --- /dev/null +++ b/gnulib-tests/null-ptr.h @@ -0,0 +1,33 @@ +/* Return a NULL pointer, without letting the compiler know it. + Copyright (C) 2017-2023 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 . */ |