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https://github.com/fluencelabs/musl
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16675df793
this could actually cause rare crashes in the case where a short string is located at the end of a page and the following page is not readable, and in fact this was seen in gcc compiling certain files.
27 lines
631 B
C
27 lines
631 B
C
#include <string.h>
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#include <stdlib.h>
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#include <stdint.h>
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#include <limits.h>
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#define ALIGN (sizeof(size_t)-1)
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#define ONES ((size_t)-1/UCHAR_MAX)
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#define HIGHS (ONES * (UCHAR_MAX/2+1))
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#define HASZERO(x) ((x)-ONES & ~(x) & HIGHS)
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char *strchr(const char *s, int c)
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{
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size_t *w, k;
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c = (unsigned char)c;
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if (!c) return (char *)s + strlen(s);
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for (; ((uintptr_t)s & ALIGN); s++)
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if (*(unsigned char *)s == c) return (char *)s;
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else if (!*s) return 0;
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k = ONES * c;
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for (w = (void *)s; !HASZERO(*w) && !HASZERO(*w^k); w++);
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for (s = (void *)w; *s; s++)
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if (*(unsigned char *)s == c) return (char *)s;
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return 0;
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}
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