summaryrefslogtreecommitdiff
path: root/src/multibyte
AgeCommit message (Collapse)AuthorFilesLines
2014-12-18fix return value computation in one code path of wcsnrtombsRich Felker1-1/+1
the affected code was wrongly counting characters instead of bytes.
2014-11-15implement a private state for the uchar.h functionsJens Gustedt3-0/+6
The C standard is imperative on that: 7.28.1 ... If ps is a null pointer, each function uses its own internal mbstate_t object instead, which is initialized at program startup to the initial conversion state; and these functions are also not supposed to implicitly use the state of the wchar.h functions: 7.29.6.3 ... The implementation behaves as if no library function calls these functions with a null pointer for ps. Previously this resulted in two bugs. - The functions c16rtomb and mbrtoc16 would crash when called with ps set to null. - The function mbrtoc32 used the private state of mbrtowc, which it is not allowed to do.
2014-10-13implement uchar.h (C11 UTF-16/32 conversion) interfacesRich Felker4-0/+79
2014-07-01fix aliasing violations in mbtowc and mbrtowcRich Felker2-2/+4
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.
2014-06-02fix incorrect end pointer in some cases when wcsrtombs stops earlyRich Felker1-7/+15
when wcsrtombs stopped due to hitting zero remaining space in the output buffer, it was wrongly clearing the position pointer as if it had completed the conversion successfully. this commit rearranges the code somewhat to make a clear separation between the cases of ending due to running out of output buffer space, and ending due to reaching the end of input or an illegal sequence in the input. the new branches have been arranged with the hope of optimizing more common cases, too.
2013-12-12include cleanups: remove unused headers and add feature test macrosSzabolcs Nagy13-51/+3
2013-09-27fix buffer overflow in mbsrtowcsRich Felker1-1/+1
issue reported by Michael Forney: "If wn becomes 0 after processing a chunk of 4, mbsrtowcs currently continues on, wrapping wn around to -1, causing the rest of the string to be processed. This resulted in buffer overruns if there was only space in ws for wn wide characters." the original patch submitted added an additional check for !wn after the loop; to avoid extra branching, I instead just changed the wn>=4 check to wn>=5 to ensure that at least one slot remains after the word-at-a-time loop runs. this should not slow down the tail processing on real-world usage, since an extra slot that can't be processed in the word-at-a-time loop is needed for the null termination anyway.
2013-06-29fix failure of mbsrtowcs to record stop position when dest is fullRich Felker1-1/+4
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.
2013-04-08implement mbtowc directly, not as a wrapper for mbrtowcRich Felker1-5/+39
the interface contract for mbtowc admits a much faster implementation than mbrtowc can achieve; wrapping mbrtowc with an extra call frame only made the situation worse. since the regex implementation uses mbtowc already, this change should improve regex performance too. it may be possible to improve performance in other places internally by switching from mbrtowc to mbtowc.
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.
2013-04-08fix out-of-bounds access in UTF-8 decodingRich Felker1-1/+1
SA and SB are used as the lowest and highest valid starter bytes, but the value of SB was one-past the last valid starter. this caused access past the end of the state table when the illegal byte '\xf5' was encountered in a starter position. the error did not show up in full-character decoding tests, since the bogus state read from just past the table was unlikely to admit any continuation bytes as valid, but would have shown up had we tested feeding '\xf5' to the byte-at-a-time decoding in mbrtowc: it would cause the funtion to wrongly return -2 rather than -1. I may eventually go back and remove all references to SA and SB, replacing them with the values; this would make the code more transparent, I think. the original motivation for using macros was to allow misguided users of the code to redefine them for the purpose of enlarging the set of accepted sequences past the end of Unicode...
2013-04-04cleanup wcstombsRich Felker1-12/+1
remove redundant headers and comments; this file is completely trivial now. also, avoid temp var.
2013-04-04cleanup mbstowcs wrapperRich Felker1-10/+0
remove unneeded headers. this file is utterly trivial now and there's no sense in having a comment to state that it's in the public domain.
2013-04-04minor optimization to mbstowcsRich Felker1-2/+1
there is no need to zero-fill an mbstate_t object in the caller; mbsrtowcs will automatically treat a null pointer as the initial state.
2013-04-04fix incorrect range checks in wcsrtombsRich Felker1-3/+3
negative values of wchar_t need to be treated in the non-ASCII case so that they can properly generate EILSEQ rather than getting truncated to 8bit values and stored in the output.
2013-04-04overhaul mbsrtowcsRich Felker1-69/+64
these changes fix at least two bugs: - misaligned access to the input as uint32_t for vectorized ASCII test - incorrect src pointer after stopping on EILSEQ in addition, the text of the standard makes it unclear whether the mbstate_t object is to be modified when the destination pointer is null; previously it was cleared either way; now, it's only cleared when the destination is non-null. this change may need revisiting, but it should not affect most applications, since calling mbsrtowcs with non-zero state can only happen when the head of the string was already processed with mbrtowc. finally, these changes shave about 20% size off the function and seem to improve performance by 1-5%.
2012-09-06use restrict everywhere it's required by c99 and/or posix 2008Rich Felker10-11/+12
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.
2012-05-26fix failure of mbsinit(0) (not UB; required to return nonzero)Rich Felker1-1/+1
issue reported by Richard Pennington; slightly simpler fix applied
2012-05-02fix longstanding exit logic bugs in mbsnrtowcs and wcsnrtombsRich Felker2-4/+9
these are POSIX 2008 (previously GNU extension) functions that are rarely used. apparently they had never been tested before, since the end-of-string logic was completely missing. mbsnrtowcs is used by modern versions of bash for its glob implementation, and and this bug was causing tab completion to hang in an infinite loop.
2012-02-24new attempt at working around the gcc 3 visibility bugRich Felker1-0/+4
since gcc is failing to generate the necessary ".hidden" directive in the output asm, generate it explicitly with an __asm__ statement...
2012-02-24remove useless attribute visibility from definitionsRich Felker1-1/+1
this was a failed attempt at working around the gcc 3 visibility bug affecting x86_64. subsequent patch will address it with an ugly but working hack.
2012-02-23cleanup and work around visibility bug in gcc 3 that affects x86_64Rich Felker2-6/+4
in gcc 3, the visibility attribute must be placed on both the declaration and on the definition. if it's omitted from the definition, the compiler fails to emit the ".hidden" directive in the assembly, and the linker will either generate textrels (if supported, such as on i386) or refuse to link (on targets where certain types of textrels are forbidden or impossible without further assumptions about memory layout, such as on x86_64). this patch also unifies the decision about when to use visibility into libc.h and makes the visibility in the utf-8 state machine tables based on libc.h rather than a duplicate test.
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.
2011-02-27cleanup utf-8 multibyte code, use visibility if possibleRich Felker3-84/+5
this code was written independently of musl, with support for a the backwards, nonstandard "31-bit unicode" some libraries/apps might want. unfortunately the extra code (inside #ifdef) makes the source harder to read and makes code that should be simple look complex, so i'm removing it. anyone who wants to use the old code can find it in the history or from elsewhere. also, change the visibility of the __fsmu8 state machine table to hidden, if supported. this should improve performance slightly in shared-library builds.
2011-02-21remove sample utf-8 code that's not part of the standard libraryRich Felker1-47/+0
2011-02-13cleanup multibyte stuff to remove ugly casts, sanitize the ptr align castsRich Felker3-27/+27
2011-02-12initial check-in, version 0.5.0v0.5.0Rich Felker18-0/+694