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author | Rich Felker <dalias@aerifal.cx> | 2014-07-01 18:27:19 -0400 |
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committer | Rich Felker <dalias@aerifal.cx> | 2014-07-28 00:27:58 -0400 |
commit | 726df5a8bc03a30afdb123edfeae5da180b77f79 (patch) | |
tree | dfcc41ca95d10a8f151dd4f688153cff405a64ac /src/multibyte/mbtowc.c | |
parent | 37eb19e0908697e8ef810cf350a52d2009959f1a (diff) | |
download | musl-726df5a8bc03a30afdb123edfeae5da180b77f79.tar.gz musl-726df5a8bc03a30afdb123edfeae5da180b77f79.tar.xz musl-726df5a8bc03a30afdb123edfeae5da180b77f79.zip |
fix aliasing violations in mbtowc and mbrtowc
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. (cherry picked from commit e89cfe51d2001af08fc2a13e5133ba8157f90beb)
Diffstat (limited to 'src/multibyte/mbtowc.c')
-rw-r--r-- | src/multibyte/mbtowc.c | 3 |
1 files changed, 2 insertions, 1 deletions
diff --git a/src/multibyte/mbtowc.c b/src/multibyte/mbtowc.c index 6710637a..803d2213 100644 --- a/src/multibyte/mbtowc.c +++ b/src/multibyte/mbtowc.c @@ -12,10 +12,11 @@ int mbtowc(wchar_t *restrict wc, const char *restrict src, size_t n) { unsigned c; const unsigned char *s = (const void *)src; + wchar_t dummy; if (!s) return 0; if (!n) goto ilseq; - if (!wc) wc = (void *)&wc; + if (!wc) wc = &dummy; if (*s < 0x80) return !!(*wc = *s); if (*s-SA > SB-SA) goto ilseq; |