/src/Python-3.8.3/Python/mystrtoul.c

Source

#include "Python.h"

#if defined(__sgi) && !defined(_SGI_MP_SOURCE)
#define _SGI_MP_SOURCE
#endif

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


#include <ctype.h>
#ifdef HAVE_ERRNO_H
#include <errno.h>
#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(Py_CHARMASK(*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(Py_CHARMASK(*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(Py_CHARMASK(*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;
}

Coverage Report

Created: 2025-10-27 06:40

Line	Count	Source
1
2		#include "Python.h"
3
4		#if defined(__sgi) && !defined(_SGI_MP_SOURCE)
5		#define _SGI_MP_SOURCE
6		#endif
7
8		/* strtol and strtoul, renamed to avoid conflicts */
9
10
11		#include <ctype.h>
12		#ifdef HAVE_ERRNO_H
13		#include <errno.h>
14		#endif
15
16		/* Static overflow check values for bases 2 through 36.
17		* smallmax[base] is the largest unsigned long i such that
18		* i * base doesn't overflow unsigned long.
19		*/
20		static const unsigned long smallmax[] = {
21		0, /* bases 0 and 1 are invalid */
22		0,
23		ULONG_MAX / 2,
24		ULONG_MAX / 3,
25		ULONG_MAX / 4,
26		ULONG_MAX / 5,
27		ULONG_MAX / 6,
28		ULONG_MAX / 7,
29		ULONG_MAX / 8,
30		ULONG_MAX / 9,
31		ULONG_MAX / 10,
32		ULONG_MAX / 11,
33		ULONG_MAX / 12,
34		ULONG_MAX / 13,
35		ULONG_MAX / 14,
36		ULONG_MAX / 15,
37		ULONG_MAX / 16,
38		ULONG_MAX / 17,
39		ULONG_MAX / 18,
40		ULONG_MAX / 19,
41		ULONG_MAX / 20,
42		ULONG_MAX / 21,
43		ULONG_MAX / 22,
44		ULONG_MAX / 23,
45		ULONG_MAX / 24,
46		ULONG_MAX / 25,
47		ULONG_MAX / 26,
48		ULONG_MAX / 27,
49		ULONG_MAX / 28,
50		ULONG_MAX / 29,
51		ULONG_MAX / 30,
52		ULONG_MAX / 31,
53		ULONG_MAX / 32,
54		ULONG_MAX / 33,
55		ULONG_MAX / 34,
56		ULONG_MAX / 35,
57		ULONG_MAX / 36,
58		};
59
60		/* maximum digits that can't ever overflow for bases 2 through 36,
61		* calculated by [int(math.floor(math.log(2**32, i))) for i in range(2, 37)].
62		* Note that this is pessimistic if sizeof(long) > 4.
63		*/
64		#if SIZEOF_LONG == 4
65		static const int digitlimit[] = {
66		0, 0, 32, 20, 16, 13, 12, 11, 10, 10, /* 0 - 9 */
67		9, 9, 8, 8, 8, 8, 8, 7, 7, 7, /* 10 - 19 */
68		7, 7, 7, 7, 6, 6, 6, 6, 6, 6, /* 20 - 29 */
69		6, 6, 6, 6, 6, 6, 6}; /* 30 - 36 */
70		#elif SIZEOF_LONG == 8
71		/* [int(math.floor(math.log(2*64, i))) for i in range(2, 37)] /
72		static const int digitlimit[] = {
73		0, 0, 64, 40, 32, 27, 24, 22, 21, 20, /* 0 - 9 */
74		19, 18, 17, 17, 16, 16, 16, 15, 15, 15, /* 10 - 19 */
75		14, 14, 14, 14, 13, 13, 13, 13, 13, 13, /* 20 - 29 */
76		13, 12, 12, 12, 12, 12, 12}; /* 30 - 36 */
77		#else
78		#error "Need table for SIZEOF_LONG"
79		#endif
80
81		/*
82		** strtoul
83		** This is a general purpose routine for converting
84		** an ascii string to an integer in an arbitrary base.
85		** Leading white space is ignored. If 'base' is zero
86		** it looks for a leading 0b, 0o or 0x to tell which
87		** base. If these are absent it defaults to 10.
88		** Base must be 0 or between 2 and 36 (inclusive).
89		** If 'ptr' is non-NULL it will contain a pointer to
90		** the end of the scan.
91		** Errors due to bad pointers will probably result in
92		** exceptions - we don't check for them.
93		*/
94		unsigned long
95		PyOS_strtoul(const char str, char *ptr, int base)
96	30	{
97	30	unsigned long result = 0; /* return value of the function */
98	30	int c; /* current input character */
99	30	int ovlimit; /* required digits to overflow */
100
101		/* skip leading white space */
102	30	while (str && Py_ISSPACE(Py_CHARMASK(str)))
103	0	++str;
104
105		/* check for leading 0b, 0o or 0x for auto-base or base 16 */
106	30	switch (base) {
107	30	case 0: /* look for leading 0b, 0o or 0x */
108	30	if (*str == '0') {
109	14	++str;
110	14	if (str == 'x' \|\| str == 'X') {
111		/* there must be at least one digit after 0x */
112	0	if (_PyLong_DigitValue[Py_CHARMASK(str[1])] >= 16) {
113	0	if (ptr)
114	0	ptr = (char )str;
115	0	return 0;
116	0	}
117	0	++str;
118	0	base = 16;
119	14	} else if (str == 'o' \|\| str == 'O') {
120		/* there must be at least one digit after 0o */
121	0	if (_PyLong_DigitValue[Py_CHARMASK(str[1])] >= 8) {
122	0	if (ptr)
123	0	ptr = (char )str;
124	0	return 0;
125	0	}
126	0	++str;
127	0	base = 8;
128	14	} else if (str == 'b' \|\| str == 'B') {
129		/* there must be at least one digit after 0b */
130	0	if (_PyLong_DigitValue[Py_CHARMASK(str[1])] >= 2) {
131	0	if (ptr)
132	0	ptr = (char )str;
133	0	return 0;
134	0	}
135	0	++str;
136	0	base = 2;
137	14	} else {
138		/* skip all zeroes... */
139	14	while (*str == '0')
140	0	++str;
141	14	while (Py_ISSPACE(Py_CHARMASK(*str)))
142	0	++str;
143	14	if (ptr)
144	14	ptr = (char )str;
145	14	return 0;
146	14	}
147	14	}
148	16	else
149	16	base = 10;
150	16	break;
151
152		/* even with explicit base, skip leading 0? prefix */
153	16	case 16:
154	0	if (*str == '0') {
155	0	++str;
156	0	if (str == 'x' \|\| str == 'X') {
157		/* there must be at least one digit after 0x */
158	0	if (_PyLong_DigitValue[Py_CHARMASK(str[1])] >= 16) {
159	0	if (ptr)
160	0	ptr = (char )str;
161	0	return 0;
162	0	}
163	0	++str;
164	0	}
165	0	}
166	0	break;
167	0	case 8:
168	0	if (*str == '0') {
169	0	++str;
170	0	if (str == 'o' \|\| str == 'O') {
171		/* there must be at least one digit after 0o */
172	0	if (_PyLong_DigitValue[Py_CHARMASK(str[1])] >= 8) {
173	0	if (ptr)
174	0	ptr = (char )str;
175	0	return 0;
176	0	}
177	0	++str;
178	0	}
179	0	}
180	0	break;
181	0	case 2:
182	0	if(*str == '0') {
183	0	++str;
184	0	if (str == 'b' \|\| str == 'B') {
185		/* there must be at least one digit after 0b */
186	0	if (_PyLong_DigitValue[Py_CHARMASK(str[1])] >= 2) {
187	0	if (ptr)
188	0	ptr = (char )str;
189	0	return 0;
190	0	}
191	0	++str;
192	0	}
193	0	}
194	0	break;
195	30	}
196
197		/* catch silly bases */
198	16	if (base < 2 \|\| base > 36) {
199	0	if (ptr)
200	0	ptr = (char )str;
201	0	return 0;
202	0	}
203
204		/* skip leading zeroes */
205	16	while (*str == '0')
206	0	++str;
207
208		/* base is guaranteed to be in [2, 36] at this point */
209	16	ovlimit = digitlimit[base];
210
211		/* do the conversion until non-digit character encountered */
212	44	while ((c = _PyLong_DigitValue[Py_CHARMASK(*str)]) < base) {
213	28	if (ovlimit > 0) /* no overflow check required */
214	28	result = result * base + c;
215	0	else { /* requires overflow check */
216	0	unsigned long temp_result;
217
218	0	if (ovlimit < 0) /* guaranteed overflow */
219	0	goto overflowed;
220
221		/* there could be an overflow */
222		/* check overflow just from shifting */
223	0	if (result > smallmax[base])
224	0	goto overflowed;
225
226	0	result *= base;
227
228		/* check overflow from the digit's value */
229	0	temp_result = result + c;
230	0	if (temp_result < result)
231	0	goto overflowed;
232
233	0	result = temp_result;
234	0	}
235
236	28	++str;
237	28	--ovlimit;
238	28	}
239
240		/* set pointer to point to the last character scanned */
241	16	if (ptr)
242	16	ptr = (char )str;
243
244	16	return result;
245
246	0	overflowed:
247	0	if (ptr) {
248		/* spool through remaining digit characters */
249	0	while (_PyLong_DigitValue[Py_CHARMASK(*str)] < base)
250	0	++str;
251	0	ptr = (char )str;
252	0	}
253	0	errno = ERANGE;
254	0	return (unsigned long)-1;
255	16	}
256
257		/* Checking for overflow in PyOS_strtol is a PITA; see comments
258		* about PY_ABS_LONG_MIN in longobject.c.
259		*/
260	0	#define PY_ABS_LONG_MIN (0-(unsigned long)LONG_MIN)
261
262		long
263		PyOS_strtol(const char str, char *ptr, int base)
264	16	{
265	16	long result;
266	16	unsigned long uresult;
267	16	char sign;
268
269	16	while (str && Py_ISSPACE(Py_CHARMASK(str)))
270	0	str++;
271
272	16	sign = *str;
273	16	if (sign == '+' \|\| sign == '-')
274	0	str++;
275
276	16	uresult = PyOS_strtoul(str, ptr, base);
277
278	16	if (uresult <= (unsigned long)LONG_MAX) {
279	16	result = (long)uresult;
280	16	if (sign == '-')
281	0	result = -result;
282	16	}
283	0	else if (sign == '-' && uresult == PY_ABS_LONG_MIN) {
284	0	result = LONG_MIN;
285	0	}
286	0	else {
287	0	errno = ERANGE;
288		result = LONG_MAX;
289	0	}
290	16	return result;
291	16	}