[uclibc-ng-devel] Re: [PATCH] libc/sysdeps/linux/common/bits/wchar.h: resync with glibc, fix build issue with gcc 12

The current definition of __WCHAR_MIN and __WCHAR_MAX are only correct when wchar_t is an int. This is not the case on ARM/AArch64 where wchar_t is an unsigned int, or some other architectures where wchar_t is a long. The current incorrect definition causes a build issue for example when building mpd, which uses boost, with gcc 12.x: In file included from /home/thomas/buildroot/aarch64/host/aarch64-buildroot-linux-uclibc/sysroot/usr/include/boost/integer.hpp:20, from /home/thomas/buildroot/aarch64/host/aarch64-buildroot-linux-uclibc/sysroot/usr/include/boost/crc.hpp:42, from ../src/storage/StorageState.cxx:43: /home/thomas/buildroot/aarch64/host/aarch64-buildroot-linux-uclibc/sysroot/usr/include/boost/integer_traits.hpp:105:69: error: narrowing conversion of ‘-2147483648’ from ‘int’ to ‘wchar_t’ [-Wnarrowing] 105 | public detail::integer_traits_base<wchar_t, WCHAR_MIN, WCHAR_MAX> | ^ This issue was fixed in glibc in 2013, see bug report https://sourceware.org/bugzilla/show_bug.cgi?id=15036, and upstream commit https://sourceware.org/git/?p=glibc.git;a=commit;h=052aff95782fefe9c6356647…. Since the i386-specific definition of __WCHAR_MIN and __WCHAR_MAX was also removed at the same time in glibc, we do the same as part of this commit. Reported-by: Clément Ramirez &lt;clement.ramirez(a)bootlin.com&gt; With-some-useful-help-from: Paul Kocialkowski &lt;paul.kocialkowski(a)bootlin.com&gt; Signed-off-by: Thomas Petazzoni &lt;thomas.petazzoni(a)bootlin.com&gt; --- libc/sysdeps/linux/common/bits/wchar.h | 32 ++++++++++++++++++++++---- libc/sysdeps/linux/i386/bits/wchar.h | 25 -------------------- 2 files changed, 28 insertions(+), 29 deletions(-) delete mode 100644 libc/sysdeps/linux/i386/bits/wchar.h diff --git a/libc/sysdeps/linux/common/bits/wchar.h b/libc/sysdeps/linux/common/bits/wchar.h index a3ff5319e..50c7ef37b 100644 --- a/libc/sysdeps/linux/common/bits/wchar.h +++ b/libc/sysdeps/linux/common/bits/wchar.h @@ -1,5 +1,5 @@ /* wchar_t type related definitions. - Copyright (C) 2000 Free Software Foundation, Inc. + Copyright (C) 2000-2022 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 @@ -14,12 +14,36 @@ 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/>. */ + <https://www.gnu.org/licenses/>. */ #ifndef _BITS_WCHAR_H #define _BITS_WCHAR_H 1 -#define __WCHAR_MIN (-2147483647 - 1) -#define __WCHAR_MAX (2147483647) +/* The fallback definitions, for when __WCHAR_MAX__ or __WCHAR_MIN__ + are not defined, give the right value and type as long as both int + and wchar_t are 32-bit types. Adding L'\0' to a constant value + ensures that the type is correct; it is necessary to use (L'\0' + + 0) rather than just L'\0' so that the type in C++ is the promoted + version of wchar_t rather than the distinct wchar_t type itself. + Because wchar_t in preprocessor #if expressions is treated as + intmax_t or uintmax_t, the expression (L'\0' - 1) would have the + wrong value for WCHAR_MAX in such expressions and so cannot be used + to define __WCHAR_MAX in the unsigned case. */ + +#ifdef __WCHAR_MAX__ +# define __WCHAR_MAX __WCHAR_MAX__ +#elif L'\0' - 1 > 0 +# define __WCHAR_MAX (0xffffffffu + L'\0') +#else +# define __WCHAR_MAX (0x7fffffff + L'\0') +#endif + +#ifdef __WCHAR_MIN__ +# define __WCHAR_MIN __WCHAR_MIN__ +#elif L'\0' - 1 > 0 +# define __WCHAR_MIN (L'\0' + 0) +#else +# define __WCHAR_MIN (-__WCHAR_MAX - 1) +#endif #endif /* bits/wchar.h */ diff --git a/libc/sysdeps/linux/i386/bits/wchar.h b/libc/sysdeps/linux/i386/bits/wchar.h deleted file mode 100644 index b94fc7a3f..000000000 --- a/libc/sysdeps/linux/i386/bits/wchar.h +++ /dev/null @@ -1,25 +0,0 @@ -/* wchar_t type related definitions. - Copyright (C) 2000 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/>. */ - -#ifndef _BITS_WCHAR_H -#define _BITS_WCHAR_H 1 - -#define __WCHAR_MIN (-2147483647l - 1l) -#define __WCHAR_MAX (2147483647l) - -#endif /* bits/wchar.h */ -- 2.41.0 _______________________________________________ devel mailing list -- devel(a)uclibc-ng.org To unsubscribe send an email to devel-leave(a)uclibc-ng.org