stdio.c

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/*
 * Copyright (C) Paul Mackerras 1997.
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * as published by the Free Software Foundation; either version
 * 2 of the License, or (at your option) any later version.
 */
#include <stdarg.h>
#include <stddef.h>
#include "string.h"
#include "stdio.h"
#include "ops.h"

size_t strnlen(const char * s, size_t count)
{
    const char *sc;

    for (sc = s; count-- && *sc != '\0'; ++sc)
        /* nothing */;
    return sc - s;
}

extern unsigned int __div64_32(unsigned long long *dividend,
                   unsigned int divisor);

/* The unnecessary pointer compare is there
 * to check for type safety (n must be 64bit)
 */
# define do_div(n,base) ({                      \
    unsigned int __base = (base);                   \
    unsigned int __rem;                     \
    (void)(((typeof((n)) *)0) == ((unsigned long long *)0));    \
    if (((n) >> 32) == 0) {                     \
        __rem = (unsigned int)(n) % __base;         \
        (n) = (unsigned int)(n) / __base;           \
    } else                              \
        __rem = __div64_32(&(n), __base);           \
    __rem;                              \
 })

static int skip_atoi(const char **s)
{
    int i, c;

    for (i = 0; '0' <= (c = **s) && c <= '9'; ++*s)
        i = i*10 + c - '0';
    return i;
}

#define ZEROPAD 1       /* pad with zero */
#define SIGN    2       /* unsigned/signed long */
#define PLUS    4       /* show plus */
#define SPACE   8       /* space if plus */
#define LEFT    16      /* left justified */
#define SPECIAL 32      /* 0x */
#define LARGE   64      /* use 'ABCDEF' instead of 'abcdef' */

static char * number(char * str, unsigned long long num, int base, int size, int precision, int type)
{
    char c,sign,tmp[66];
    const char *digits="0123456789abcdefghijklmnopqrstuvwxyz";
    int i;

    if (type & LARGE)
        digits = "0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZ";
    if (type & LEFT)
        type &= ~ZEROPAD;
    if (base < 2 || base > 36)
        return 0;
    c = (type & ZEROPAD) ? '0' : ' ';
    sign = 0;
    if (type & SIGN) {
        if ((signed long long)num < 0) {
            sign = '-';
            num = - (signed long long)num;
            size--;
        } else if (type & PLUS) {
            sign = '+';
            size--;
        } else if (type & SPACE) {
            sign = ' ';
            size--;
        }
    }
    if (type & SPECIAL) {
        if (base == 16)
            size -= 2;
        else if (base == 8)
            size--;
    }
    i = 0;
    if (num == 0)
        tmp[i++]='0';
    else while (num != 0) {
        tmp[i++] = digits[do_div(num, base)];
    }
    if (i > precision)
        precision = i;
    size -= precision;
    if (!(type&(ZEROPAD+LEFT)))
        while(size-->0)
            *str++ = ' ';
    if (sign)
        *str++ = sign;
    if (type & SPECIAL) {
        if (base==8)
            *str++ = '0';
        else if (base==16) {
            *str++ = '0';
            *str++ = digits[33];
        }
    }
    if (!(type & LEFT))
        while (size-- > 0)
            *str++ = c;
    while (i < precision--)
        *str++ = '0';
    while (i-- > 0)
        *str++ = tmp[i];
    while (size-- > 0)
        *str++ = ' ';
    return str;
}

int vsprintf(char *buf, const char *fmt, va_list args)
{
    int len;
    unsigned long long num;
    int i, base;
    char * str;
    const char *s;

    int flags;      /* flags to number() */

    int field_width;    /* width of output field */
    int precision;      /* min. # of digits for integers; max
                   number of chars for from string */
    int qualifier;      /* 'h', 'l', or 'L' for integer fields */
                            /* 'z' support added 23/7/1999 S.H.    */
                /* 'z' changed to 'Z' --davidm 1/25/99 */

    
    for (str=buf ; *fmt ; ++fmt) {
        if (*fmt != '%') {
            *str++ = *fmt;
            continue;
        }
            
        /* process flags */
        flags = 0;
        repeat:
            ++fmt;      /* this also skips first '%' */
            switch (*fmt) {
                case '-': flags |= LEFT; goto repeat;
                case '+': flags |= PLUS; goto repeat;
                case ' ': flags |= SPACE; goto repeat;
                case '#': flags |= SPECIAL; goto repeat;
                case '0': flags |= ZEROPAD; goto repeat;
                }
        
        /* get field width */
        field_width = -1;
        if ('0' <= *fmt && *fmt <= '9')
            field_width = skip_atoi(&fmt);
        else if (*fmt == '*') {
            ++fmt;
            /* it's the next argument */
            field_width = va_arg(args, int);
            if (field_width < 0) {
                field_width = -field_width;
                flags |= LEFT;
            }
        }

        /* get the precision */
        precision = -1;
        if (*fmt == '.') {
            ++fmt;  
            if ('0' <= *fmt && *fmt <= '9')
                precision = skip_atoi(&fmt);
            else if (*fmt == '*') {
                ++fmt;
                /* it's the next argument */
                precision = va_arg(args, int);
            }
            if (precision < 0)
                precision = 0;
        }

        /* get the conversion qualifier */
        qualifier = -1;
        if (*fmt == 'l' && *(fmt + 1) == 'l') {
            qualifier = 'q';
            fmt += 2;
        } else if (*fmt == 'h' || *fmt == 'l' || *fmt == 'L'
            || *fmt == 'Z') {
            qualifier = *fmt;
            ++fmt;
        }

        /* default base */
        base = 10;

        switch (*fmt) {
        case 'c':
            if (!(flags & LEFT))
                while (--field_width > 0)
                    *str++ = ' ';
            *str++ = (unsigned char) va_arg(args, int);
            while (--field_width > 0)
                *str++ = ' ';
            continue;

        case 's':
            s = va_arg(args, char *);
            if (!s)
                s = "<NULL>";

            len = strnlen(s, precision);

            if (!(flags & LEFT))
                while (len < field_width--)
                    *str++ = ' ';
            for (i = 0; i < len; ++i)
                *str++ = *s++;
            while (len < field_width--)
                *str++ = ' ';
            continue;

        case 'p':
            if (field_width == -1) {
                field_width = 2*sizeof(void *);
                flags |= ZEROPAD;
            }
            str = number(str,
                (unsigned long) va_arg(args, void *), 16,
                field_width, precision, flags);
            continue;


        case 'n':
            if (qualifier == 'l') {
                long * ip = va_arg(args, long *);
                *ip = (str - buf);
            } else if (qualifier == 'Z') {
                size_t * ip = va_arg(args, size_t *);
                *ip = (str - buf);
            } else {
                int * ip = va_arg(args, int *);
                *ip = (str - buf);
            }
            continue;

        case '%':
            *str++ = '%';
            continue;

        /* integer number formats - set up the flags and "break" */
        case 'o':
            base = 8;
            break;

        case 'X':
            flags |= LARGE;
        case 'x':
            base = 16;
            break;

        case 'd':
        case 'i':
            flags |= SIGN;
        case 'u':
            break;

        default:
            *str++ = '%';
            if (*fmt)
                *str++ = *fmt;
            else
                --fmt;
            continue;
        }
        if (qualifier == 'l') {
            num = va_arg(args, unsigned long);
            if (flags & SIGN)
                num = (signed long) num;
        } else if (qualifier == 'q') {
            num = va_arg(args, unsigned long long);
            if (flags & SIGN)
                num = (signed long long) num;
        } else if (qualifier == 'Z') {
            num = va_arg(args, size_t);
        } else if (qualifier == 'h') {
            num = (unsigned short) va_arg(args, int);
            if (flags & SIGN)
                num = (signed short) num;
        } else {
            num = va_arg(args, unsigned int);
            if (flags & SIGN)
                num = (signed int) num;
        }
        str = number(str, num, base, field_width, precision, flags);
    }
    *str = '\0';
    return str-buf;
}

int sprintf(char * buf, const char *fmt, ...)
{
    va_list args;
    int i;

    va_start(args, fmt);
    i=vsprintf(buf,fmt,args);
    va_end(args);
    return i;
}

static char sprint_buf[1024];

int
printf(const char *fmt, ...)
{
    va_list args;
    int n;

    va_start(args, fmt);
    n = vsprintf(sprint_buf, fmt, args);
    va_end(args);
    if (console_ops.write)
        console_ops.write(sprint_buf, n);
    return n;
}