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| author | Rich Felker <dalias@aerifal.cx> | 2014-07-01 18:27:19 -0400 |
|---|---|---|
| committer | Rich Felker <dalias@aerifal.cx> | 2014-07-28 00:27:58 -0400 |
| commit | 726df5a8bc03a30afdb123edfeae5da180b77f79 (patch) | |
| tree | dfcc41ca95d10a8f151dd4f688153cff405a64ac /src | |
| parent | 37eb19e0908697e8ef810cf350a52d2009959f1a (diff) | |
| download | musl-726df5a8bc03a30afdb123edfeae5da180b77f79.tar.gz | |
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')
| -rw-r--r-- | src/multibyte/mbrtowc.c | 3 | ||||
| -rw-r--r-- | src/multibyte/mbtowc.c | 3 |
2 files changed, 4 insertions, 2 deletions
diff --git a/src/multibyte/mbrtowc.c b/src/multibyte/mbrtowc.c index 35e834ee..e7b36540 100644 --- a/src/multibyte/mbrtowc.c +++ b/src/multibyte/mbrtowc.c @@ -14,6 +14,7 @@ size_t mbrtowc(wchar_t *restrict wc, const char *restrict src, size_t n, mbstate unsigned c; const unsigned char *s = (const void *)src; const unsigned N = n; + wchar_t dummy; if (!st) st = (void *)&internal_state; c = *(unsigned *)st; @@ -21,7 +22,7 @@ size_t mbrtowc(wchar_t *restrict wc, const char *restrict src, size_t n, mbstate if (!s) { if (c) goto ilseq; return 0; - } else if (!wc) wc = (void *)&wc; + } else if (!wc) wc = &dummy; if (!n) return -2; if (!c) { 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; |