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/* Copyright (c) 2002,2004,2005 Joerg Wunsch
Copyright (c) 2008 Dmitry Xmelkov
All rights reserved.
Redistribution and use in source and binary forms, with or without
modification, are permitted provided that the following conditions are met:
* Redistributions of source code must retain the above copyright
notice, this list of conditions and the following disclaimer.
* Redistributions in binary form must reproduce the above copyright
notice, this list of conditions and the following disclaimer in
the documentation and/or other materials provided with the
distribution.
* Neither the name of the copyright holders nor the names of
contributors may be used to endorse or promote products derived
from this software without specific prior written permission.
THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
POSSIBILITY OF SUCH DAMAGE.
*/
#include <ctype.h>
#include <limits.h>
#include <math.h>
#include <stdarg.h>
#include <stddef.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <errno.h>
#include <stdbool.h>
#define CASE_CONVERT ('a' - 'A')
#define TOLOW(c) ((c) | CASE_CONVERT)
#if defined(_HAVE_BUILTIN_MUL_OVERFLOW) && defined(_HAVE_BUILTIN_ADD_OVERFLOW) && !defined(strtoi_signed)
#define USE_OVERFLOW
#endif
static inline bool
ISSPACE(unsigned char c)
{
return ('\011' <= c && c <= '\015') || c == ' ';
}
strtoi_type
strtoi(const char *__restrict nptr, char **__restrict endptr, int ibase)
{
/* Check for invalid base value */
if ((unsigned int) ibase > 36 || ibase == 1) {
errno = EINVAL;
if (endptr)
*endptr = (char *) nptr;
return 0;
}
#define FLAG_NEG 0x1 /* Negative. Must be 1 for ucutoff below */
#define FLAG_OFLOW 0x2 /* Value overflow */
const unsigned char *s = (const unsigned char *) nptr;
strtoi_type val = 0;
unsigned char flags = 0;
unsigned char base = (unsigned char) ibase;
unsigned char i;
/* Skip leading spaces */
do {
i = *s++;
} while (ISSPACE(i));
/* Parse a leading sign */
switch (i) {
case '-':
flags = FLAG_NEG;
FALLTHROUGH;
case '+':
i = *s++;
}
/* Leading '0' digit -- check for base indication */
if (i == '0') {
if (TOLOW(*s) == 'x' && (base == 0 || base == 16)) {
base = 16;
/* Parsed the '0' */
nptr = (const char *) s;
i = s[1];
s += 2;
} else if (base == 0) {
base = 8;
}
} else if (base == 0) {
base = 10;
}
#ifndef USE_OVERFLOW
/* Compute values used to detect overflow. */
#ifdef strtoi_signed
/* works because strtoi_min = (strtoi_type) ((strtoi_utype) strtoi_max + 1) */
strtoi_utype ucutoff = (strtoi_utype) strtoi_max + flags;
strtoi_type cutoff = ucutoff / base;
unsigned cutlim = ucutoff % base;
#else
strtoi_type cutoff = strtoi_max / base;
unsigned cutlim = strtoi_max % base;
#endif
#endif
for(;;) {
/* Map digits to 0..35, non-digits above 35. */
if (i > '9')
i = TOLOW(i-1) + ('0' - 'a' + 11);
i -= '0';
/* detect invalid char */
if (i >= base)
break;
/* Add the new digit, checking for overflow */
#ifdef USE_OVERFLOW
/*
* This isn't used for signed values as it's tricky and
* generates larger code. Yes, it avoids doing the divmod
* above, but we'll assume an app doing math with signed
* values will probably end up doing a divide somewhere
*/
if (__builtin_mul_overflow(val, (strtoi_type) base, &val) ||
__builtin_add_overflow(val, (strtoi_type) i, &val))
{
flags |= FLAG_OFLOW;
}
#else
if (val > cutoff || (val == cutoff && i > cutlim))
flags |= FLAG_OFLOW;
val = val * (strtoi_type) base + i;
#endif
/* Parsed another digit */
nptr = (const char *) s;
i = *s++;
}
if (flags & FLAG_NEG)
val = -val;
if (flags & FLAG_OFLOW) {
#ifdef strtoi_signed
val = (strtoi_type) ucutoff;
#else
val = strtoi_max;
#endif
errno = ERANGE;
}
/* Mark the end of the parsed region */
if (endptr != NULL)
*endptr = (char *) nptr;
return val;
}
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