| // 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 | |
| #if defined(__sgi) && !defined(_SGI_MP_SOURCE) | |
| # define _SGI_MP_SOURCE | |
| #endif | |
| /* 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; | |
| } |