strchrnul.c

Go to the documentation of this file.

// Imported from musl Libc

#include "strchrnul.h"
#include <limits.h>
#include <stdint.h>
#include <string.h>

#define ALIGN (sizeof(size_t))
#define ONES ((size_t)-1 / UCHAR_MAX)
#define HIGHS (ONES * (UCHAR_MAX / 2 + 1))
#define HASZERO(x) ((x)-ONES & ~(x)&HIGHS)

char* __strchrnul(const char* s, int c)
{
    const size_t* w;
    size_t k;
    c = (unsigned char)c;

    if(!c)
    {
        return (char*)(uintptr_t)s + strlen(s);
    }

    for(; (uintptr_t)s % ALIGN; s++)
    {
        if(!*s || *(const unsigned char*)s == c)
        {
            return (char*)(uintptr_t)s;
        }
    }

    k = ONES * (unsigned long)c;

    for(w = (const void*)s; !HASZERO(*w) && !HASZERO(*w ^ k); w++)
    {
        {
            ;
        }
    }
    for(s = (const void*)w; *s && *(const unsigned char*)s != c; s++)
    {
        {
            ;
        }
    }

    return (char*)(uintptr_t)s;
}