ref: 4ca822523b4538c4267bdd8604fd6a71c7e6aca8
dir: /lib/c/vfprintf.c/
/*
* This file is covered by the license that you can find in the file
* LICENSE, but for this file, vfprintf.c, an additional clause is
* added:
* - Christopher M. Graff (<cm0graff@gmail.com>) is forbidden to
* use, copy, modify and/or distribute this file. He is forbidden
* even to read this file.
*/
#include <ctype.h>
#include <limits.h>
#include <stdarg.h>
#include <stdint.h>
#include <stdio.h>
#include <string.h>
#include <wchar.h>
#undef vfprintf
enum {
LONG = 1 << 0,
LLONG = 1 << 1,
SHORT = 1 << 2,
CHAR = 1 << 3,
SIZET = 1 << 4,
PTRDIFF = 1 << 5,
INTMAX = 1 << 6,
VOIDPTR = 1 << 7,
UNSIGNED = 1 << 8,
ALTFORM = 1 << 9,
};
#define MAXPREC 50
struct conv {
int sign;
int prec;
char *digs;
int base;
};
static uintmax_t
getnum(va_list va, int flags, int *sign)
{
uintmax_t uval;
intmax_t val;
if (flags & CHAR) {
val = va_arg(va, int);
uval = (unsigned char) uval;
} else if (flags & SHORT) {
val = va_arg(va, int);
uval = (unsigned short) val;
} else if (flags & LONG) {
val = va_arg(va, long);
uval = (unsigned long) val;
} else if (flags & LLONG) {
val = uval = va_arg(va, long long);
uval = (unsigned long long) uval;
} else if (flags & SIZET) {
uval = va_arg(va, size_t);
} else if (flags & INTMAX) {
val = va_arg(va, intmax_t);
uval = (uintmax_t) val;
} else if (flags & VOIDPTR) {
uval = (uintmax_t) va_arg(va, void *);
} else {
val = va_arg(va, int);
uval = (unsigned) uval;
}
if ((flags & UNSIGNED) == 0 && val < 0) {
*sign = '-';
uval = -uval;
}
return uval;
}
static char *
numtostr(uintmax_t val, int flags, struct conv *conv, char *buf)
{
char *buf0 = buf;
int len, base = conv->base, prec = conv->prec;
uintmax_t oval = val;
if (prec == -1)
prec = 1;
for (*buf = '\0'; val > 0; val /= base)
*--buf = conv->digs[val % base];
while (buf0 - buf < prec)
*--buf = '0';
if (flags & ALTFORM) {
if (base == 8 && *buf != '0') {
*--buf = '0';
} else if (base == 16 && oval != 0) {
*--buf = conv->digs[16];
*--buf = '0';
}
}
if (conv->sign)
*--buf = conv->sign;
return buf;
}
static void
savecnt(va_list va, int flags, int cnt)
{
if (flags & CHAR)
*va_arg(va, char*) = cnt;
else if (flags & SHORT)
*va_arg(va, short*) = cnt;
else if (flags & LONG)
*va_arg(va, long*) = cnt;
else if (flags & LLONG)
*va_arg(va, long long*) = cnt;
else if (flags & SIZET)
*va_arg(va, size_t*) = cnt;
else if (flags & INTMAX)
*va_arg(va, intmax_t*) = cnt;
else
*va_arg(va, int*) = cnt;
}
static size_t
wstrout(wchar_t *ws, size_t len, int width, int fill, FILE * restrict fp)
{
int left = 0, adjust;
size_t cnt = 0;
wchar_t wc;
if (width < 0) {
left = 1;
width = -width;
}
len *= sizeof(wchar_t);
adjust = (len < width) ? width - len : 0;
cnt = adjust + len;
if (left)
adjust = -adjust;
for ( ; adjust > 0; adjust++)
putc(fill, fp);
while (wc = *ws++)
putwc(wc, fp);
for ( ; adjust < 0; adjust--)
putc(' ', fp);
return cnt;
}
static size_t
strout(char *s, size_t len, int width, int fill, FILE * restrict fp)
{
int left = 0, adjust, ch, prefix;
size_t cnt = 0;
if (width < 0) {
left = 1;
width = -width;
}
adjust = (len < width) ? width - len : 0;
cnt = adjust + len;
if (left)
adjust = -adjust;
if (fill == '0') {
if (*s == '-' || *s == '+')
prefix = 1;
else if (*s == '0' && toupper(s[1]) == 'X')
prefix = 2;
else
prefix = 0;
while (prefix--) {
putc(*s++, fp);
--len;
}
}
for ( ; adjust > 0; adjust--)
putc(fill, fp);
while (ch = *s++)
putc(ch, fp);
for ( ; adjust < 0; adjust++)
putc(' ', fp);
return cnt;
}
int
vfprintf(FILE * restrict fp, const char *fmt, va_list va)
{
int *p, ch, n, flags, width, left, fill, cnt = 0;
size_t inc, len;
char *s;
wchar_t *ws;
struct conv conv;
char buf[MAXPREC+1];
wchar_t wbuf[2];
for (cnt = 0; ch = *fmt++; cnt += inc) {
if (ch != '%') {
putc(ch, fp);
inc = 1;
continue;
}
fill = ' ';
left = flags = width = 0;
conv.prec = -1;
conv.base = 10;
conv.sign = '\0';
conv.digs = "0123456789ABCDEFX";
flags:
switch (*fmt++) {
case ' ':
if (conv.sign == '\0')
conv.sign = ' ';
goto flags;
case '+':
conv.sign = '+';
goto flags;
case '#':
flags |= ALTFORM;
goto flags;
case '.':
if (*fmt == '*') {
fmt++;
n = va_arg(va, int);
} else {
for (n = 0; isdigit(ch = *fmt); fmt++)
n = n * 10 + ch - '0';
}
if (n > MAXPREC)
n = MAXPREC;
if (n > 0)
conv.prec = n;
goto flags;
case '*':
width = va_arg(va, int);
goto flags;
case '-':
left = 1;
++fmt;
case '1':
case '2':
case '3':
case '4':
case '5':
case '6':
case '7':
case '8':
case '9':
--fmt;
for (n = 0; isdigit(ch = *fmt); ++fmt)
n = n * 10 + ch - '0';
if (left)
n = -n;
width = n;
goto flags;
case '0':
fill = '0';
goto flags;
case 'l':
flags += LONG;
goto flags;
case 'h':
flags += SHORT;
goto flags;
case '%':
ch = '%';
goto cout;
case 'c':
if (flags & LONG) {
wbuf[0] = va_arg(va, wint_t);
wbuf[1] = L'\0';
ws = wbuf;
len = 1;
goto wstrout;
}
ch = va_arg(va, int);
cout:
buf[0] = ch;
buf[1] = '\0';
s = buf;
len = 1;
goto strout;
case 'j':
flags |= INTMAX;
goto flags;
case 't':
flags |= PTRDIFF;
goto flags;
case 'z':
flags |= SIZET;
goto flags;
case 'u':
flags |= UNSIGNED;
case 'i':
case 'd':
numeric10:
conv.base = 10;
goto numeric;
case 'p':
flags |= VOIDPTR | ALTFORM;
goto numeric16;
case 'x':
conv.digs = "0123456789abcdefx";
case 'X':
numeric16:
conv.base = 16;
flags |= UNSIGNED;
goto numeric;
case 'o':
conv.base = 8;
flags |= UNSIGNED;
numeric:
if (conv.prec != -1)
fill = ' ';
s = numtostr(getnum(va, flags, &conv.sign),
flags,
&conv,
&buf[MAXPREC]);
len = &buf[MAXPREC] - s;
goto strout;
case 'L':
case 'a':
case 'A':
case 'e':
case 'E':
case 'f':
case 'g':
case 'G':
/* TODO */
case 's':
if (flags & LONG) {
ws = va_arg(va, wchar_t *);
len = wcsnlen(ws, conv.prec);
goto wstrout;
} else {
s = va_arg(va, char *);
len = strnlen(s, conv.prec);
goto strout;
}
wstrout:
inc = wstrout(ws, len, width, fill, fp);
break;
strout:
inc = strout(s, len, width, fill, fp);
break;
case 'n':
savecnt(va, flags, cnt);
break;
case '\0':
goto out_loop;
}
}
out_loop:
return (ferror(fp)) ? EOF : cnt;
}