Backport of commit 052aff95782fefe9c63566471063e8b20836bfb8 Author: Joseph Myers Date: Wed Jan 23 00:42:51 2013 +0000 Make bits/wchar.h correct for all architectures (bug 15036). 2013-01-23 Joseph Myers [BZ #15036] * bits/wchar.h (__WCHAR_MAX): Define based on __WCHAR_MAX__, or based on [L'\0' - 1 > 0] if [!__WCHAR_MAX__]. (__WCHAR_MIN): Likewise, using __WCHAR_MIN__. * sysdeps/unix/sysv/linux/x86/bits/wchar.h: Remove. diff -ruNp glibc-2.17-c758a686/bits/wchar.h glibc-2.17-c758a686/bits/wchar.h --- glibc-2.17-c758a686/bits/wchar.h 2012-12-24 22:02:13.000000000 -0500 +++ glibc-2.17-c758a686/bits/wchar.h 2014-03-27 14:53:45.940914030 -0400 @@ -19,7 +19,31 @@ #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 */