diff options
Diffstat (limited to 'sysdeps/x86/tst-ldbl-nonnormal-printf.c')
-rw-r--r-- | sysdeps/x86/tst-ldbl-nonnormal-printf.c | 52 |
1 files changed, 52 insertions, 0 deletions
diff --git a/sysdeps/x86/tst-ldbl-nonnormal-printf.c b/sysdeps/x86/tst-ldbl-nonnormal-printf.c new file mode 100644 index 0000000000..54381ece0b --- /dev/null +++ b/sysdeps/x86/tst-ldbl-nonnormal-printf.c @@ -0,0 +1,52 @@ +/* Test printf with x86-specific non-normal long double value. + Copyright (C) 2020 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 + <https://www.gnu.org/licenses/>. */ + +#include <stdio.h> +#include <string.h> +#include <support/check.h> + +/* Fill the stack with non-zero values. This makes a crash in + snprintf more likely. */ +static void __attribute__ ((noinline, noclone)) +fill_stack (void) +{ + char buffer[65536]; + memset (buffer, 0xc0, sizeof (buffer)); + asm ("" ::: "memory"); +} + +static int +do_test (void) +{ + fill_stack (); + + long double value; + memcpy (&value, "\x00\x04\x00\x00\x00\x00\x00\x00\x00\x04", 10); + + char buf[30]; + int ret = snprintf (buf, sizeof (buf), "%Lg", value); + TEST_COMPARE (ret, strlen (buf)); + if (strcmp (buf, "nan") != 0) + /* If snprintf does not recognize the non-normal number as a NaN, + it has added the missing explicit MSB. */ + TEST_COMPARE_STRING (buf, "3.02201e-4624"); + return 0; +} + +#include <support/test-driver.c> |