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// strtol() and strtoul(), renamed to avoid conflicts.

//

// API:

//

// - PyOS_strtol(): convert string to C long integer.

// - PyOS_strtoul(): convert string to C unsigned long integer.

#include "Python.h"

#include "pycore_long.h" // _PyLong_DigitValue

/* strtol and strtoul, renamed to avoid conflicts */

#ifdef HAVE_ERRNO_H

# include <errno.h> // errno

#endif

/* Static overflow check values for bases 2 through 36.

* smallmax[base] is the largest unsigned long i such that

* i * base doesn't overflow unsigned long.

*/

static const unsigned long smallmax[] = {

0, /* bases 0 and 1 are invalid */

0,

ULONG_MAX / 2,

ULONG_MAX / 3,

ULONG_MAX / 4,

ULONG_MAX / 5,

ULONG_MAX / 6,

ULONG_MAX / 7,

ULONG_MAX / 8,

ULONG_MAX / 9,

ULONG_MAX / 10,

ULONG_MAX / 11,

ULONG_MAX / 12,

ULONG_MAX / 13,

ULONG_MAX / 14,

ULONG_MAX / 15,

ULONG_MAX / 16,

ULONG_MAX / 17,

ULONG_MAX / 18,

ULONG_MAX / 19,

ULONG_MAX / 20,

ULONG_MAX / 21,

ULONG_MAX / 22,

ULONG_MAX / 23,

ULONG_MAX / 24,

ULONG_MAX / 25,

ULONG_MAX / 26,

ULONG_MAX / 27,

ULONG_MAX / 28,

ULONG_MAX / 29,

ULONG_MAX / 30,

ULONG_MAX / 31,

ULONG_MAX / 32,

ULONG_MAX / 33,

ULONG_MAX / 34,

ULONG_MAX / 35,

ULONG_MAX / 36,

};

/* maximum digits that can't ever overflow for bases 2 through 36,

* calculated by [int(math.floor(math.log(2**32, i))) for i in range(2, 37)].

* Note that this is pessimistic if sizeof(long) > 4.

*/

#if SIZEOF_LONG == 4

static const int digitlimit[] = {

0, 0, 32, 20, 16, 13, 12, 11, 10, 10, /* 0 - 9 */

9, 9, 8, 8, 8, 8, 8, 7, 7, 7, /* 10 - 19 */

7, 7, 7, 7, 6, 6, 6, 6, 6, 6, /* 20 - 29 */

6, 6, 6, 6, 6, 6, 6}; /* 30 - 36 */

#elif SIZEOF_LONG == 8

/* [int(math.floor(math.log(2**64, i))) for i in range(2, 37)] */

static const int digitlimit[] = {

0, 0, 64, 40, 32, 27, 24, 22, 21, 20, /* 0 - 9 */

19, 18, 17, 17, 16, 16, 16, 15, 15, 15, /* 10 - 19 */

14, 14, 14, 14, 13, 13, 13, 13, 13, 13, /* 20 - 29 */

13, 12, 12, 12, 12, 12, 12}; /* 30 - 36 */

#else

# error "Need table for SIZEOF_LONG"

#endif

/*

** strtoul

** This is a general purpose routine for converting

** an ascii string to an integer in an arbitrary base.

** Leading white space is ignored. If 'base' is zero

** it looks for a leading 0b, 0o or 0x to tell which

** base. If these are absent it defaults to 10.

** Base must be 0 or between 2 and 36 (inclusive).

** If 'ptr' is non-NULL it will contain a pointer to

** the end of the scan.

** Errors due to bad pointers will probably result in

** exceptions - we don't check for them.

*/

unsigned long

PyOS_strtoul(const char *str, char **ptr, int base)

{

unsigned long result = 0; /* return value of the function */

int c; /* current input character */

int ovlimit; /* required digits to overflow */

/* skip leading white space */

while (*str && Py_ISSPACE(*str))

++str;

/* check for leading 0b, 0o or 0x for auto-base or base 16 */

switch (base) {

case 0: /* look for leading 0b, 0o or 0x */

if (*str == '0') {

++str;

if (*str == 'x' || *str == 'X') {

/* there must be at least one digit after 0x */

if (_PyLong_DigitValue[Py_CHARMASK(str[1])] >= 16) {

if (ptr)

*ptr = (char *)str;

return 0;

}

++str;

base = 16;

} else if (*str == 'o' || *str == 'O') {

/* there must be at least one digit after 0o */

if (_PyLong_DigitValue[Py_CHARMASK(str[1])] >= 8) {

if (ptr)

*ptr = (char *)str;

return 0;

}

++str;

base = 8;

} else if (*str == 'b' || *str == 'B') {

/* there must be at least one digit after 0b */

if (_PyLong_DigitValue[Py_CHARMASK(str[1])] >= 2) {

if (ptr)

*ptr = (char *)str;

return 0;

}

++str;

base = 2;

} else {

/* skip all zeroes... */

while (*str == '0')

++str;

while (Py_ISSPACE(*str))

++str;

if (ptr)

*ptr = (char *)str;

return 0;

}

}

else

base = 10;

break;

/* even with explicit base, skip leading 0? prefix */

case 16:

if (*str == '0') {

++str;

if (*str == 'x' || *str == 'X') {

/* there must be at least one digit after 0x */

if (_PyLong_DigitValue[Py_CHARMASK(str[1])] >= 16) {

if (ptr)

*ptr = (char *)str;

return 0;

}

++str;

}

}

break;

case 8:

if (*str == '0') {

++str;

if (*str == 'o' || *str == 'O') {

/* there must be at least one digit after 0o */

if (_PyLong_DigitValue[Py_CHARMASK(str[1])] >= 8) {

if (ptr)

*ptr = (char *)str;

return 0;

}

++str;

}

}

break;

case 2:

if(*str == '0') {

++str;

if (*str == 'b' || *str == 'B') {

/* there must be at least one digit after 0b */

if (_PyLong_DigitValue[Py_CHARMASK(str[1])] >= 2) {

if (ptr)

*ptr = (char *)str;

return 0;

}

++str;

}

}

break;

}

/* catch silly bases */

if (base < 2 || base > 36) {

if (ptr)

*ptr = (char *)str;

return 0;

}

/* skip leading zeroes */

while (*str == '0')

++str;

/* base is guaranteed to be in [2, 36] at this point */

ovlimit = digitlimit[base];

/* do the conversion until non-digit character encountered */

while ((c = _PyLong_DigitValue[Py_CHARMASK(*str)]) < base) {

if (ovlimit > 0) /* no overflow check required */

result = result * base + c;

else { /* requires overflow check */

unsigned long temp_result;

if (ovlimit < 0) /* guaranteed overflow */

goto overflowed;

/* there could be an overflow */

/* check overflow just from shifting */

if (result > smallmax[base])

goto overflowed;

result *= base;

/* check overflow from the digit's value */

temp_result = result + c;

if (temp_result < result)

goto overflowed;

result = temp_result;

}

++str;

--ovlimit;

}

/* set pointer to point to the last character scanned */

if (ptr)

*ptr = (char *)str;

return result;

overflowed:

if (ptr) {

/* spool through remaining digit characters */

while (_PyLong_DigitValue[Py_CHARMASK(*str)] < base)

++str;

*ptr = (char *)str;

}

errno = ERANGE;

return (unsigned long)-1;

}

/* Checking for overflow in PyOS_strtol is a PITA; see comments

* about PY_ABS_LONG_MIN in longobject.c.

*/

#define PY_ABS_LONG_MIN (0-(unsigned long)LONG_MIN)

long

PyOS_strtol(const char *str, char **ptr, int base)

{

long result;

unsigned long uresult;

char sign;

while (*str && Py_ISSPACE(*str))

str++;

sign = *str;

if (sign == '+' || sign == '-')

str++;

uresult = PyOS_strtoul(str, ptr, base);

if (uresult <= (unsigned long)LONG_MAX) {

result = (long)uresult;

if (sign == '-')

result = -result;

}

else if (sign == '-' && uresult == PY_ABS_LONG_MIN) {

result = LONG_MIN;

}

else {

errno = ERANGE;

result = LONG_MAX;

}

return result;

}