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| author | Joseph Myers <joseph@codesourcery.com> | 2018-06-12 16:57:26 +0000 |
|---|---|---|
| committer | Joseph Myers <joseph@codesourcery.com> | 2018-06-12 16:57:26 +0000 |
| commit | 48b12ed54ceb605ec3566249c0387612fd9c0ced (patch) | |
| tree | 43a7f68212ad2c7597718969d1dd77e31188cee8 /math/test-nan-const.c | |
| parent | cb8f6affed52d81819037b2f5d6f3a089abb8811 (diff) | |
| download | glibc-48b12ed54ceb605ec3566249c0387612fd9c0ced.tar.gz | |
Do not use const attribute for nan functions (bug 23277).
As in https://gcc.gnu.org/bugzilla/show_bug.cgi?id=86113 for
__builtin_nan, bits/mathcalls.h wrongly declares the nan function with
the __const__ attribute. Because the function reads memory pointed to
by an argument, it's only pure, not const. This patch removes the
incorrect attribute and adds a testcase for the bug. No __pure__
attribute is added to replace the incorrect __const__ one, since that
would introduce problems when using GCC versions that have the
incorrect built-in __const__ attribute and warn for the combination of
those two attributes.
Tested for x86_64.
[BZ #23277]
* math/bits/mathcalls.h [__USE_ISOC99] (nan): Do not use __const__
attribute.
* math/test-nan-const.c: New file.
* math/Makefile (tests): Add test-nan-const.
(CFLAGS-test-nan-const.c): New variable.
Diffstat (limited to 'math/test-nan-const.c')
| -rw-r--r-- | math/test-nan-const.c | 32 |
1 files changed, 32 insertions, 0 deletions
diff --git a/math/test-nan-const.c b/math/test-nan-const.c new file mode 100644 index 0000000000..f7bba9eeb6 --- /dev/null +++ b/math/test-nan-const.c @@ -0,0 +1,32 @@ +/* Test nan functions do not have const attribute. Bug 23277. + Copyright (C) 2018 Free Software Foundation, Inc. + This file is part of the GNU C Library. + + The GNU C Library is free software; you can redistribute it and/or + modify it under the terms of the GNU Lesser General Public + License as published by the Free Software Foundation; either + version 2.1 of the License, or (at your option) any later version. + + The GNU C Library 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 + Lesser General Public License for more details. + + You should have received a copy of the GNU Lesser General Public + License along with the GNU C Library; if not, see + <http://www.gnu.org/licenses/>. */ + +#include <math.h> +#include <string.h> + +static int +do_test (void) +{ + char buf[2] = { '2', 0 }; + float a = nanf (buf); + buf[0] = '3'; + float b = nanf (buf); + return memcmp (&a, &b, sizeof (float)) == 0; +} + +#include <support/test-driver.c> |