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| -rw-r--r-- | docs/wchar_and_locale.txt | 114 |
1 files changed, 114 insertions, 0 deletions
diff --git a/docs/wchar_and_locale.txt b/docs/wchar_and_locale.txt new file mode 100644 index 000000000..67605e0bc --- /dev/null +++ b/docs/wchar_and_locale.txt @@ -0,0 +1,114 @@ + User-configurable + +UCLIBC_HAS_CTYPE_TABLES + Make toupper etc work thru translation tables + and isalhum etc thru lookup tables. Help says: + "While the non-table versions are often smaller when building + statically linked apps, they work only in stub locale mode." + + "stub locale mode" is when !UCLIBC_HAS_LOCALE I presume, + when we are permanently in POSIX/C locale. + +UCLIBC_HAS_CTYPE_SIGNED + Handle sign-extended chars. I.e. if you want + toupper((char)0xa0) => toupper(0xffffffa0) => still works correctly, + as if toupper(0xa0) was called. + +UCLIBC_HAS_CTYPE_UNSAFE/CHECKED/ENFORCED + Do not check ctype function argument's range/check it and return + error/check it and abort(). Help says: + NOTE: This only affects the 'ctype' _functions_. It does not affect + the macro implementations. [so what happens to macros?] + [examples?] + +UCLIBC_HAS_WCHAR + Wide character support. I assume all those wchar_t types and functions + +UCLIBC_HAS_LOCALE/XLOCALE + Support locale / extended locale + +UCLIBC_PREGENERATED_LOCALE_DATA + Not recommended + + + uclibc internal machinery + +__LOCALE_C_ONLY + #defined if !UCLIBC_HAS_LOCALE + +__NO_CTYPE + #defined only by some .c files. Prevents ctype macros to be #defined + (those w/o underscores. __ctype() macros will still be defined). + Looks like user is expected to never mess with defining it. + +__UCLIBC_DO_XLOCALE + #defined only by some .c files. Looks like user is expected to never + mess with defining it. + +__XL_NPP(N) - "add _l suffix if locale support is on" + #defined to N ## _l if __UCLIBC_HAS_XLOCALE__ && __UCLIBC_DO_XLOCALE, + else #defined to just N. + +__CTYPE_HAS_8_BIT_LOCALES +__CTYPE_HAS_UTF_8_LOCALES + Depends on contents of extra/locale/LOCALES data file. Looks like + both will be set if UCLIBC_HAS_LOCALE and extra/locale/LOCALES + is not edited. + +__WCHAR_ENABLED + locale_mmap.h defines it unconditionally, extra/locale/gen_ldc.c + defines it too with a warning, and _then_ includes locale_mmap.h. + Makefile seems to prevent the warning in gen_ldc.c: + ifeq ($(UCLIBC_HAS_WCHAR),y) + BUILD_CFLAGS-gen_wc8bit += -DDO_WIDE_CHAR=1 + BUILD_CFLAGS-gen_ldc += -D__WCHAR_ENABLED=1 + endif + A mess. Why they can't just use __UCLIBC_HAS_WCHAR__? + +__WCHAR_REPLACEMENT_CHAR + Never defined (dead code???) + + + + Actual ctype macros are a bloody mess! + +ctype.h +... +... +#define __isctype(c, type) \ + ((__UCLIBC_CTYPE_B)[(int) (c)] & (__ctype_mask_t) type) + +#define __isascii(c) (((c) & ~0x7f) == 0) /* If C is a 7 bit value. */ +#define __toascii(c) ((c) & 0x7f) /* Mask off high bits. */ +#define __isdigit_char(C) (((unsigned char)((C) - '0')) <= 9) +#define __isdigit_int(C) (((unsigned int)((C) - '0')) <= 9) + +# define isalnum(c) __isctype((c), _ISalnum) +# define isalpha(c) __isctype((c), _ISalpha) + +# if __GNUC__ >= 2 && defined __OPTIMIZE__ && !defined __cplusplus +# define tolower(c) __tobody (c, tolower, __UCLIBC_CTYPE_TOLOWER, (c)) +# define toupper(c) __tobody (c, toupper, __UCLIBC_CTYPE_TOUPPER, (c)) +# endif /* Optimizing gcc */ + +# if defined __USE_SVID || defined __USE_MISC || defined __USE_XOPEN +# define isascii(c) __isascii (c) +# define toascii(c) __toascii (c) +# define _tolower(c) ((int) (__UCLIBC_CTYPE_TOLOWER)[(int) (c)]) +# define _toupper(c) ((int) (__UCLIBC_CTYPE_TOUPPER)[(int) (c)]) +# endif +... +... + +bits/uClibc_ctype.h +... +... +#define __tolower(c) __body(tolower,c) +#define __toupper(c) __body(toupper,c) + +#define _toupper(c) ((c) ^ 0x20) +#define _tolower(c) ((c) | 0x20) +... +... + +WTF?! We have (at least) TWO DIFFERENT _tolower's? |