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glibc/stdlib/strtold_nan.c

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Refactor strtod parsing of NaN payloads. The nan* functions handle their string argument by constructing a NAN(...) string on the stack as a VLA and passing it to strtod functions. This approach has problems discussed in bug 16961 and bug 16962: the stack usage is unbounded, and it gives incorrect results in certain cases where the argument is not a valid n-char-sequence. The natural fix for both issues is to refactor the NaN payload parsing out of strtod into a separate function that the nan* functions can call directly, so that no temporary string needs constructing on the stack at all. This patch does that refactoring in preparation for fixing those bugs (but without actually using the new functions from nan* - which will also require exporting them from libc at version GLIBC_PRIVATE). This patch is not intended to change any user-visible behavior, so no tests are added (fixes for the above bugs will of course add tests for them). This patch builds on my recent fixes for strtol and strtod issues in Turkish locales. Given those fixes, the parsing of NaN payloads is locale-independent; thus, the new functions do not need to take a locale_t argument. Tested for x86_64, x86, mips64 and powerpc. * stdlib/strtod_nan.c: New file. * stdlib/strtod_nan_double.h: Likewise. * stdlib/strtod_nan_float.h: Likewise. * stdlib/strtod_nan_main.c: Likewise. * stdlib/strtod_nan_narrow.h: Likewise. * stdlib/strtod_nan_wide.h: Likewise. * stdlib/strtof_nan.c: Likewise. * stdlib/strtold_nan.c: Likewise. * sysdeps/ieee754/ldbl-128/strtod_nan_ldouble.h: Likewise. * sysdeps/ieee754/ldbl-128ibm/strtod_nan_ldouble.h: Likewise. * sysdeps/ieee754/ldbl-96/strtod_nan_ldouble.h: Likewise. * wcsmbs/wcstod_nan.c: Likewise. * wcsmbs/wcstof_nan.c: Likewise. * wcsmbs/wcstold_nan.c: Likewise. * stdlib/Makefile (routines): Add strtof_nan, strtod_nan and strtold_nan. * wcsmbs/Makefile (routines): Add wcstod_nan, wcstold_nan and wcstof_nan. * include/stdlib.h (__strtof_nan): Declare and use libc_hidden_proto. (__strtod_nan): Likewise. (__strtold_nan): Likewise. (__wcstof_nan): Likewise. (__wcstod_nan): Likewise. (__wcstold_nan): Likewise. * include/wchar.h (____wcstoull_l_internal): Declare. * stdlib/strtod_l.c: Do not include <ieee754.h>. (____strtoull_l_internal): Remove declaration. (STRTOF_NAN): Define macro. (SET_MANTISSA): Remove macro. (STRTOULL): Likewise. (____STRTOF_INTERNAL): Use STRTOF_NAN to parse NaN payload. * stdlib/strtof_l.c (____strtoull_l_internal): Remove declaration. (STRTOF_NAN): Define macro. (SET_MANTISSA): Remove macro. * sysdeps/ieee754/ldbl-128/strtold_l.c (STRTOF_NAN): Define macro. (SET_MANTISSA): Remove macro. * sysdeps/ieee754/ldbl-128ibm/strtold_l.c (STRTOF_NAN): Define macro. (SET_MANTISSA): Remove macro. * sysdeps/ieee754/ldbl-64-128/strtold_l.c (STRTOF_NAN): Define macro. (SET_MANTISSA): Remove macro. * sysdeps/ieee754/ldbl-96/strtold_l.c (STRTOF_NAN): Define macro. (SET_MANTISSA): Remove macro. * wcsmbs/wcstod_l.c (____wcstoull_l_internal): Remove declaration. * wcsmbs/wcstof_l.c (____wcstoull_l_internal): Likewise. * wcsmbs/wcstold_l.c (____wcstoull_l_internal): Likewise.
2015-11-25 06:24:52 +08:00
/* Convert string for NaN payload to corresponding NaN. Narrow
strings, long double.
Update copyright dates with scripts/update-copyrights.
2016-01-05 00:05:18 +08:00
Copyright (C) 2015-2016 Free Software Foundation, Inc.
Refactor strtod parsing of NaN payloads. The nan* functions handle their string argument by constructing a NAN(...) string on the stack as a VLA and passing it to strtod functions. This approach has problems discussed in bug 16961 and bug 16962: the stack usage is unbounded, and it gives incorrect results in certain cases where the argument is not a valid n-char-sequence. The natural fix for both issues is to refactor the NaN payload parsing out of strtod into a separate function that the nan* functions can call directly, so that no temporary string needs constructing on the stack at all. This patch does that refactoring in preparation for fixing those bugs (but without actually using the new functions from nan* - which will also require exporting them from libc at version GLIBC_PRIVATE). This patch is not intended to change any user-visible behavior, so no tests are added (fixes for the above bugs will of course add tests for them). This patch builds on my recent fixes for strtol and strtod issues in Turkish locales. Given those fixes, the parsing of NaN payloads is locale-independent; thus, the new functions do not need to take a locale_t argument. Tested for x86_64, x86, mips64 and powerpc. * stdlib/strtod_nan.c: New file. * stdlib/strtod_nan_double.h: Likewise. * stdlib/strtod_nan_float.h: Likewise. * stdlib/strtod_nan_main.c: Likewise. * stdlib/strtod_nan_narrow.h: Likewise. * stdlib/strtod_nan_wide.h: Likewise. * stdlib/strtof_nan.c: Likewise. * stdlib/strtold_nan.c: Likewise. * sysdeps/ieee754/ldbl-128/strtod_nan_ldouble.h: Likewise. * sysdeps/ieee754/ldbl-128ibm/strtod_nan_ldouble.h: Likewise. * sysdeps/ieee754/ldbl-96/strtod_nan_ldouble.h: Likewise. * wcsmbs/wcstod_nan.c: Likewise. * wcsmbs/wcstof_nan.c: Likewise. * wcsmbs/wcstold_nan.c: Likewise. * stdlib/Makefile (routines): Add strtof_nan, strtod_nan and strtold_nan. * wcsmbs/Makefile (routines): Add wcstod_nan, wcstold_nan and wcstof_nan. * include/stdlib.h (__strtof_nan): Declare and use libc_hidden_proto. (__strtod_nan): Likewise. (__strtold_nan): Likewise. (__wcstof_nan): Likewise. (__wcstod_nan): Likewise. (__wcstold_nan): Likewise. * include/wchar.h (____wcstoull_l_internal): Declare. * stdlib/strtod_l.c: Do not include <ieee754.h>. (____strtoull_l_internal): Remove declaration. (STRTOF_NAN): Define macro. (SET_MANTISSA): Remove macro. (STRTOULL): Likewise. (____STRTOF_INTERNAL): Use STRTOF_NAN to parse NaN payload. * stdlib/strtof_l.c (____strtoull_l_internal): Remove declaration. (STRTOF_NAN): Define macro. (SET_MANTISSA): Remove macro. * sysdeps/ieee754/ldbl-128/strtold_l.c (STRTOF_NAN): Define macro. (SET_MANTISSA): Remove macro. * sysdeps/ieee754/ldbl-128ibm/strtold_l.c (STRTOF_NAN): Define macro. (SET_MANTISSA): Remove macro. * sysdeps/ieee754/ldbl-64-128/strtold_l.c (STRTOF_NAN): Define macro. (SET_MANTISSA): Remove macro. * sysdeps/ieee754/ldbl-96/strtold_l.c (STRTOF_NAN): Define macro. (SET_MANTISSA): Remove macro. * wcsmbs/wcstod_l.c (____wcstoull_l_internal): Remove declaration. * wcsmbs/wcstof_l.c (____wcstoull_l_internal): Likewise. * wcsmbs/wcstold_l.c (____wcstoull_l_internal): Likewise.
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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>
/* This function is unused if long double and double have the same
representation. */
#ifndef __NO_LONG_DOUBLE_MATH
# include <strtod_nan_narrow.h>
# include <strtod_nan_ldouble.h>
# define STRTOD_NAN __strtold_nan
# include <strtod_nan_main.c>
#endif
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