565 lines
12 KiB
C
565 lines
12 KiB
C
// SPDX-License-Identifier: GPL-2.0-only
|
|
/* -*- linux-c -*- ------------------------------------------------------- *
|
|
*
|
|
* Copyright (C) 1991, 1992 Linus Torvalds
|
|
* Copyright 2007 rPath, Inc. - All Rights Reserved
|
|
*
|
|
* ----------------------------------------------------------------------- */
|
|
|
|
/*
|
|
* Oh, it's a waste of space, but oh-so-yummy for debugging.
|
|
*/
|
|
|
|
#include <stdarg.h>
|
|
|
|
#include <linux/compiler.h>
|
|
#include <linux/ctype.h>
|
|
#include <linux/kernel.h>
|
|
#include <linux/limits.h>
|
|
#include <linux/string.h>
|
|
#include <linux/types.h>
|
|
|
|
static
|
|
int skip_atoi(const char **s)
|
|
{
|
|
int i = 0;
|
|
|
|
while (isdigit(**s))
|
|
i = i * 10 + *((*s)++) - '0';
|
|
return i;
|
|
}
|
|
|
|
/*
|
|
* put_dec_full4 handles numbers in the range 0 <= r < 10000.
|
|
* The multiplier 0xccd is round(2^15/10), and the approximation
|
|
* r/10 == (r * 0xccd) >> 15 is exact for all r < 16389.
|
|
*/
|
|
static
|
|
void put_dec_full4(char *end, unsigned int r)
|
|
{
|
|
int i;
|
|
|
|
for (i = 0; i < 3; i++) {
|
|
unsigned int q = (r * 0xccd) >> 15;
|
|
*--end = '0' + (r - q * 10);
|
|
r = q;
|
|
}
|
|
*--end = '0' + r;
|
|
}
|
|
|
|
/* put_dec is copied from lib/vsprintf.c with small modifications */
|
|
|
|
/*
|
|
* Call put_dec_full4 on x % 10000, return x / 10000.
|
|
* The approximation x/10000 == (x * 0x346DC5D7) >> 43
|
|
* holds for all x < 1,128,869,999. The largest value this
|
|
* helper will ever be asked to convert is 1,125,520,955.
|
|
* (second call in the put_dec code, assuming n is all-ones).
|
|
*/
|
|
static
|
|
unsigned int put_dec_helper4(char *end, unsigned int x)
|
|
{
|
|
unsigned int q = (x * 0x346DC5D7ULL) >> 43;
|
|
|
|
put_dec_full4(end, x - q * 10000);
|
|
return q;
|
|
}
|
|
|
|
/* Based on code by Douglas W. Jones found at
|
|
* <http://www.cs.uiowa.edu/~jones/bcd/decimal.html#sixtyfour>
|
|
* (with permission from the author).
|
|
* Performs no 64-bit division and hence should be fast on 32-bit machines.
|
|
*/
|
|
static
|
|
char *put_dec(char *end, unsigned long long n)
|
|
{
|
|
unsigned int d3, d2, d1, q, h;
|
|
char *p = end;
|
|
|
|
d1 = ((unsigned int)n >> 16); /* implicit "& 0xffff" */
|
|
h = (n >> 32);
|
|
d2 = (h ) & 0xffff;
|
|
d3 = (h >> 16); /* implicit "& 0xffff" */
|
|
|
|
/* n = 2^48 d3 + 2^32 d2 + 2^16 d1 + d0
|
|
= 281_4749_7671_0656 d3 + 42_9496_7296 d2 + 6_5536 d1 + d0 */
|
|
q = 656 * d3 + 7296 * d2 + 5536 * d1 + ((unsigned int)n & 0xffff);
|
|
q = put_dec_helper4(p, q);
|
|
p -= 4;
|
|
|
|
q += 7671 * d3 + 9496 * d2 + 6 * d1;
|
|
q = put_dec_helper4(p, q);
|
|
p -= 4;
|
|
|
|
q += 4749 * d3 + 42 * d2;
|
|
q = put_dec_helper4(p, q);
|
|
p -= 4;
|
|
|
|
q += 281 * d3;
|
|
q = put_dec_helper4(p, q);
|
|
p -= 4;
|
|
|
|
put_dec_full4(p, q);
|
|
p -= 4;
|
|
|
|
/* strip off the extra 0's we printed */
|
|
while (p < end && *p == '0')
|
|
++p;
|
|
|
|
return p;
|
|
}
|
|
|
|
static
|
|
char *number(char *end, unsigned long long num, int base, char locase)
|
|
{
|
|
/*
|
|
* locase = 0 or 0x20. ORing digits or letters with 'locase'
|
|
* produces same digits or (maybe lowercased) letters
|
|
*/
|
|
|
|
/* we are called with base 8, 10 or 16, only, thus don't need "G..." */
|
|
static const char digits[16] = "0123456789ABCDEF"; /* "GHIJKLMNOPQRSTUVWXYZ"; */
|
|
|
|
switch (base) {
|
|
case 10:
|
|
if (num != 0)
|
|
end = put_dec(end, num);
|
|
break;
|
|
case 8:
|
|
for (; num != 0; num >>= 3)
|
|
*--end = '0' + (num & 07);
|
|
break;
|
|
case 16:
|
|
for (; num != 0; num >>= 4)
|
|
*--end = digits[num & 0xf] | locase;
|
|
break;
|
|
default:
|
|
unreachable();
|
|
};
|
|
|
|
return end;
|
|
}
|
|
|
|
#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 SMALL 32 /* Must be 32 == 0x20 */
|
|
#define SPECIAL 64 /* 0x */
|
|
#define WIDE 128 /* UTF-16 string */
|
|
|
|
static
|
|
int get_flags(const char **fmt)
|
|
{
|
|
int flags = 0;
|
|
|
|
do {
|
|
switch (**fmt) {
|
|
case '-':
|
|
flags |= LEFT;
|
|
break;
|
|
case '+':
|
|
flags |= PLUS;
|
|
break;
|
|
case ' ':
|
|
flags |= SPACE;
|
|
break;
|
|
case '#':
|
|
flags |= SPECIAL;
|
|
break;
|
|
case '0':
|
|
flags |= ZEROPAD;
|
|
break;
|
|
default:
|
|
return flags;
|
|
}
|
|
++(*fmt);
|
|
} while (1);
|
|
}
|
|
|
|
static
|
|
int get_int(const char **fmt, va_list *ap)
|
|
{
|
|
if (isdigit(**fmt))
|
|
return skip_atoi(fmt);
|
|
if (**fmt == '*') {
|
|
++(*fmt);
|
|
/* it's the next argument */
|
|
return va_arg(*ap, int);
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
static
|
|
unsigned long long get_number(int sign, int qualifier, va_list *ap)
|
|
{
|
|
if (sign) {
|
|
switch (qualifier) {
|
|
case 'L':
|
|
return va_arg(*ap, long long);
|
|
case 'l':
|
|
return va_arg(*ap, long);
|
|
case 'h':
|
|
return (short)va_arg(*ap, int);
|
|
case 'H':
|
|
return (signed char)va_arg(*ap, int);
|
|
default:
|
|
return va_arg(*ap, int);
|
|
};
|
|
} else {
|
|
switch (qualifier) {
|
|
case 'L':
|
|
return va_arg(*ap, unsigned long long);
|
|
case 'l':
|
|
return va_arg(*ap, unsigned long);
|
|
case 'h':
|
|
return (unsigned short)va_arg(*ap, int);
|
|
case 'H':
|
|
return (unsigned char)va_arg(*ap, int);
|
|
default:
|
|
return va_arg(*ap, unsigned int);
|
|
}
|
|
}
|
|
}
|
|
|
|
static
|
|
char get_sign(long long *num, int flags)
|
|
{
|
|
if (!(flags & SIGN))
|
|
return 0;
|
|
if (*num < 0) {
|
|
*num = -(*num);
|
|
return '-';
|
|
}
|
|
if (flags & PLUS)
|
|
return '+';
|
|
if (flags & SPACE)
|
|
return ' ';
|
|
return 0;
|
|
}
|
|
|
|
static
|
|
size_t utf16s_utf8nlen(const u16 *s16, size_t maxlen)
|
|
{
|
|
size_t len, clen;
|
|
|
|
for (len = 0; len < maxlen && *s16; len += clen) {
|
|
u16 c0 = *s16++;
|
|
|
|
/* First, get the length for a BMP character */
|
|
clen = 1 + (c0 >= 0x80) + (c0 >= 0x800);
|
|
if (len + clen > maxlen)
|
|
break;
|
|
/*
|
|
* If this is a high surrogate, and we're already at maxlen, we
|
|
* can't include the character if it's a valid surrogate pair.
|
|
* Avoid accessing one extra word just to check if it's valid
|
|
* or not.
|
|
*/
|
|
if ((c0 & 0xfc00) == 0xd800) {
|
|
if (len + clen == maxlen)
|
|
break;
|
|
if ((*s16 & 0xfc00) == 0xdc00) {
|
|
++s16;
|
|
++clen;
|
|
}
|
|
}
|
|
}
|
|
|
|
return len;
|
|
}
|
|
|
|
static
|
|
u32 utf16_to_utf32(const u16 **s16)
|
|
{
|
|
u16 c0, c1;
|
|
|
|
c0 = *(*s16)++;
|
|
/* not a surrogate */
|
|
if ((c0 & 0xf800) != 0xd800)
|
|
return c0;
|
|
/* invalid: low surrogate instead of high */
|
|
if (c0 & 0x0400)
|
|
return 0xfffd;
|
|
c1 = **s16;
|
|
/* invalid: missing low surrogate */
|
|
if ((c1 & 0xfc00) != 0xdc00)
|
|
return 0xfffd;
|
|
/* valid surrogate pair */
|
|
++(*s16);
|
|
return (0x10000 - (0xd800 << 10) - 0xdc00) + (c0 << 10) + c1;
|
|
}
|
|
|
|
#define PUTC(c) \
|
|
do { \
|
|
if (pos < size) \
|
|
buf[pos] = (c); \
|
|
++pos; \
|
|
} while (0);
|
|
|
|
int vsnprintf(char *buf, size_t size, const char *fmt, va_list ap)
|
|
{
|
|
/* The maximum space required is to print a 64-bit number in octal */
|
|
char tmp[(sizeof(unsigned long long) * 8 + 2) / 3];
|
|
char *tmp_end = &tmp[ARRAY_SIZE(tmp)];
|
|
long long num;
|
|
int base;
|
|
const char *s;
|
|
size_t len, pos;
|
|
char sign;
|
|
|
|
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', 'hh', 'l' or 'll' for integer fields */
|
|
|
|
va_list args;
|
|
|
|
/*
|
|
* We want to pass our input va_list to helper functions by reference,
|
|
* but there's an annoying edge case. If va_list was originally passed
|
|
* to us by value, we could just pass &ap down to the helpers. This is
|
|
* the case on, for example, X86_32.
|
|
* However, on X86_64 (and possibly others), va_list is actually a
|
|
* size-1 array containing a structure. Our function parameter ap has
|
|
* decayed from T[1] to T*, and &ap has type T** rather than T(*)[1],
|
|
* which is what will be expected by a function taking a va_list *
|
|
* parameter.
|
|
* One standard way to solve this mess is by creating a copy in a local
|
|
* variable of type va_list and then passing a pointer to that local
|
|
* copy instead, which is what we do here.
|
|
*/
|
|
va_copy(args, ap);
|
|
|
|
for (pos = 0; *fmt; ++fmt) {
|
|
if (*fmt != '%' || *++fmt == '%') {
|
|
PUTC(*fmt);
|
|
continue;
|
|
}
|
|
|
|
/* process flags */
|
|
flags = get_flags(&fmt);
|
|
|
|
/* get field width */
|
|
field_width = get_int(&fmt, &args);
|
|
if (field_width < 0) {
|
|
field_width = -field_width;
|
|
flags |= LEFT;
|
|
}
|
|
|
|
if (flags & LEFT)
|
|
flags &= ~ZEROPAD;
|
|
|
|
/* get the precision */
|
|
precision = -1;
|
|
if (*fmt == '.') {
|
|
++fmt;
|
|
precision = get_int(&fmt, &args);
|
|
if (precision >= 0)
|
|
flags &= ~ZEROPAD;
|
|
}
|
|
|
|
/* get the conversion qualifier */
|
|
qualifier = -1;
|
|
if (*fmt == 'h' || *fmt == 'l') {
|
|
qualifier = *fmt;
|
|
++fmt;
|
|
if (qualifier == *fmt) {
|
|
qualifier -= 'a'-'A';
|
|
++fmt;
|
|
}
|
|
}
|
|
|
|
sign = 0;
|
|
|
|
switch (*fmt) {
|
|
case 'c':
|
|
flags &= LEFT;
|
|
s = tmp;
|
|
if (qualifier == 'l') {
|
|
((u16 *)tmp)[0] = (u16)va_arg(args, unsigned int);
|
|
((u16 *)tmp)[1] = L'\0';
|
|
precision = INT_MAX;
|
|
goto wstring;
|
|
} else {
|
|
tmp[0] = (unsigned char)va_arg(args, int);
|
|
precision = len = 1;
|
|
}
|
|
goto output;
|
|
|
|
case 's':
|
|
flags &= LEFT;
|
|
if (precision < 0)
|
|
precision = INT_MAX;
|
|
s = va_arg(args, void *);
|
|
if (!s)
|
|
s = precision < 6 ? "" : "(null)";
|
|
else if (qualifier == 'l') {
|
|
wstring:
|
|
flags |= WIDE;
|
|
precision = len = utf16s_utf8nlen((const u16 *)s, precision);
|
|
goto output;
|
|
}
|
|
precision = len = strnlen(s, precision);
|
|
goto output;
|
|
|
|
/* integer number formats - set up the flags and "break" */
|
|
case 'o':
|
|
base = 8;
|
|
break;
|
|
|
|
case 'p':
|
|
if (precision < 0)
|
|
precision = 2 * sizeof(void *);
|
|
fallthrough;
|
|
case 'x':
|
|
flags |= SMALL;
|
|
fallthrough;
|
|
case 'X':
|
|
base = 16;
|
|
break;
|
|
|
|
case 'd':
|
|
case 'i':
|
|
flags |= SIGN;
|
|
fallthrough;
|
|
case 'u':
|
|
flags &= ~SPECIAL;
|
|
base = 10;
|
|
break;
|
|
|
|
default:
|
|
/*
|
|
* Bail out if the conversion specifier is invalid.
|
|
* There's probably a typo in the format string and the
|
|
* remaining specifiers are unlikely to match up with
|
|
* the arguments.
|
|
*/
|
|
goto fail;
|
|
}
|
|
if (*fmt == 'p') {
|
|
num = (unsigned long)va_arg(args, void *);
|
|
} else {
|
|
num = get_number(flags & SIGN, qualifier, &args);
|
|
}
|
|
|
|
sign = get_sign(&num, flags);
|
|
if (sign)
|
|
--field_width;
|
|
|
|
s = number(tmp_end, num, base, flags & SMALL);
|
|
len = tmp_end - s;
|
|
/* default precision is 1 */
|
|
if (precision < 0)
|
|
precision = 1;
|
|
/* precision is minimum number of digits to print */
|
|
if (precision < len)
|
|
precision = len;
|
|
if (flags & SPECIAL) {
|
|
/*
|
|
* For octal, a leading 0 is printed only if necessary,
|
|
* i.e. if it's not already there because of the
|
|
* precision.
|
|
*/
|
|
if (base == 8 && precision == len)
|
|
++precision;
|
|
/*
|
|
* For hexadecimal, the leading 0x is skipped if the
|
|
* output is empty, i.e. both the number and the
|
|
* precision are 0.
|
|
*/
|
|
if (base == 16 && precision > 0)
|
|
field_width -= 2;
|
|
else
|
|
flags &= ~SPECIAL;
|
|
}
|
|
/*
|
|
* For zero padding, increase the precision to fill the field
|
|
* width.
|
|
*/
|
|
if ((flags & ZEROPAD) && field_width > precision)
|
|
precision = field_width;
|
|
|
|
output:
|
|
/* Calculate the padding necessary */
|
|
field_width -= precision;
|
|
/* Leading padding with ' ' */
|
|
if (!(flags & LEFT))
|
|
while (field_width-- > 0)
|
|
PUTC(' ');
|
|
/* sign */
|
|
if (sign)
|
|
PUTC(sign);
|
|
/* 0x/0X for hexadecimal */
|
|
if (flags & SPECIAL) {
|
|
PUTC('0');
|
|
PUTC( 'X' | (flags & SMALL));
|
|
}
|
|
/* Zero padding and excess precision */
|
|
while (precision-- > len)
|
|
PUTC('0');
|
|
/* Actual output */
|
|
if (flags & WIDE) {
|
|
const u16 *ws = (const u16 *)s;
|
|
|
|
while (len-- > 0) {
|
|
u32 c32 = utf16_to_utf32(&ws);
|
|
u8 *s8;
|
|
size_t clen;
|
|
|
|
if (c32 < 0x80) {
|
|
PUTC(c32);
|
|
continue;
|
|
}
|
|
|
|
/* Number of trailing octets */
|
|
clen = 1 + (c32 >= 0x800) + (c32 >= 0x10000);
|
|
|
|
len -= clen;
|
|
s8 = (u8 *)&buf[pos];
|
|
|
|
/* Avoid writing partial character */
|
|
PUTC('\0');
|
|
pos += clen;
|
|
if (pos >= size)
|
|
continue;
|
|
|
|
/* Set high bits of leading octet */
|
|
*s8 = (0xf00 >> 1) >> clen;
|
|
/* Write trailing octets in reverse order */
|
|
for (s8 += clen; clen; --clen, c32 >>= 6)
|
|
*s8-- = 0x80 | (c32 & 0x3f);
|
|
/* Set low bits of leading octet */
|
|
*s8 |= c32;
|
|
}
|
|
} else {
|
|
while (len-- > 0)
|
|
PUTC(*s++);
|
|
}
|
|
/* Trailing padding with ' ' */
|
|
while (field_width-- > 0)
|
|
PUTC(' ');
|
|
}
|
|
fail:
|
|
va_end(args);
|
|
|
|
if (size)
|
|
buf[min(pos, size-1)] = '\0';
|
|
|
|
return pos;
|
|
}
|
|
|
|
int snprintf(char *buf, size_t size, const char *fmt, ...)
|
|
{
|
|
va_list args;
|
|
int i;
|
|
|
|
va_start(args, fmt);
|
|
i = vsnprintf(buf, size, fmt, args);
|
|
va_end(args);
|
|
return i;
|
|
}
|