summaryrefslogtreecommitdiff
path: root/src/multibyte/mbrtowc.c
AgeCommit message (Collapse)AuthorFilesLines
2016-06-21remove comments on copyright status from UTF-8 implementation filesRich Felker1-6/+0
despite clarifications made to the COPYRIGHT file in commit f0a61399330bae42beeb27d6ecd05570b3382a60, there continues to be confusion about whether the permissions granted actually apply to all files. I am the sole author of these files and clearly intend, and have always intended, for the grant of permission to apply to them.
2015-06-16byte-based C locale, phase 1: multibyte character handling functionsRich Felker1-0/+2
this patch makes the functions which work directly on multibyte characters treat the high bytes as individual abstract code units rather than as multibyte sequences when MB_CUR_MAX is 1. since MB_CUR_MAX is presently defined as a constant 4, all of the new code added is dead code, and optimizing compilers' code generation should not be affected at all. a future commit will activate the new code. as abstract code units, bytes 0x80 to 0xff are represented by wchar_t values 0xdf80 to 0xdfff, at the end of the surrogates range. this ensures that they will never be misinterpreted as Unicode characters, and that all wctype functions return false for these "characters" without needing locale-specific logic. a high range outside of Unicode such as 0x7fffff80 to 0x7fffffff was also considered, but since C11's char16_t also needs to be able to represent conversions of these bytes, the surrogate range was the natural choice.
2014-07-01fix aliasing violations in mbtowc and mbrtowcRich Felker1-1/+2
these functions were setting wc to point to wchar_t aliasing itself as a "cheap" way to support null wc arguments. doing so was anything but cheap, since even without the aliasing violation, it would limit the compiler's ability to optimize. making wc point to a dummy object is equally easy and does not suffer from the above problems.
2013-12-12include cleanups: remove unused headers and add feature test macrosSzabolcs Nagy1-3/+0
2013-04-08mbrtowc: do not leave mbstate_t in permanent-fail state after EILSEQRich Felker1-1/+1
the standard is clear that the old behavior is conforming: "In this case, [EILSEQ] shall be stored in errno and the conversion state is undefined." however, the specification of mbrtowc has one peculiarity when the source argument is a null pointer: in this case, it's required to behave as mbrtowc(NULL, "", 1, ps). no motivation is provided for this requirement, but the natural one that comes to mind is that the intent is to reset the mbstate_t object. for stateful encodings, such behavior is actually specified: "If the corresponding wide character is the null wide character, the resulting state described shall be the initial conversion state." but in the case of UTF-8 where the mbstate_t object contains a partially-decoded character rather than a shift state, a subsequent '\0' byte indicates that the previous partial character is incomplete and thus an illegal sequence. naturally, applications using their own mbstate_t object should clear it themselves after an error, but the standard presently provides no way to clear the builtin mbstate_t object used when the ps argument is a null pointer. I suspect this issue may be addressed in the future by specifying that a null source argument resets the state, as this seems to have been the intent all along. for what it's worth, this change also slightly reduces code size.
2013-04-08optimize mbrtowcRich Felker1-3/+2
this simple change, in my measurements, makes about a 7% performance improvement. at first glance this change would seem like a compiler-specific hack, since the modified code is not even used. however, I suspect the reason is that I'm eliminating a second path into the main body of the code, allowing the compiler more flexibility to optimize the normal (hot) path into the main body. so even if it weren't for the measurable (and quite notable) difference in performance, I think the change makes sense.
2012-09-06use restrict everywhere it's required by c99 and/or posix 2008Rich Felker1-1/+1
to deal with the fact that the public headers may be used with pre-c99 compilers, __restrict is used in place of restrict, and defined appropriately for any supported compiler. we also avoid the form [restrict] since older versions of gcc rejected it due to a bug in the original c99 standard, and instead use the form *restrict.
2011-03-25fix all implicit conversion between signed/unsigned pointersRich Felker1-1/+1
sadly the C language does not specify any such implicit conversion, so this is not a matter of just fixing warnings (as gcc treats it) but actual errors. i would like to revisit a number of these changes and possibly revise the types used to reduce the number of casts required.
2011-02-13cleanup multibyte stuff to remove ugly casts, sanitize the ptr align castsRich Felker1-4/+4
2011-02-12initial check-in, version 0.5.0v0.5.0Rich Felker1-0/+58