ReactOS 0.4.15-dev-8413-gc1c91f2
wcstol.c
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1/*
2 * COPYRIGHT: See COPYING in the top level directory
3 * PROJECT: ReactOS system libraries
4 * FILE: lib/sdk/crt/string/wcstol.c
5 * PURPOSE: Unknown
6 * PROGRAMER: Unknown
7 * UPDATE HISTORY:
8 * 25/11/05: Added license header
9 */
10
11#include <precomp.h>
12/*
13 * @implemented
14 */
15long
17wcstol(const wchar_t *nptr, wchar_t **endptr, int base)
18{
19 const wchar_t *s = nptr;
20 long acc;
21 int c;
22 unsigned long cutoff;
23 int neg = 0, any, cutlim;
24
25 /*
26 * Skip white space and pick up leading +/- sign if any.
27 * If base is 0, allow 0x for hex and 0 for octal, else
28 * assume decimal; if base is already 16, allow 0x.
29 */
30 do {
31 c = *s++;
32 } while (iswctype(c, _SPACE));
33 if (c == '-')
34 {
35 neg = 1;
36 c = *s++;
37 }
38 else if (c == L'+')
39 c = *s++;
40 if ((base == 0 || base == 16) &&
41 c == L'0' && (*s == L'x' || *s == L'X'))
42 {
43 c = s[1];
44 s += 2;
45 base = 16;
46 }
47 if (base == 0)
48 base = c == L'0' ? 8 : 10;
49
50 /*
51 * Compute the cutoff value between legal numbers and illegal
52 * numbers. That is the largest legal value, divided by the
53 * base. An input number that is greater than this value, if
54 * followed by a legal input character, is too big. One that
55 * is equal to this value may be valid or not; the limit
56 * between valid and invalid numbers is then based on the last
57 * digit. For instance, if the range for longs is
58 * [-2147483648..2147483647] and the input base is 10,
59 * cutoff will be set to 214748364 and cutlim to either
60 * 7 (neg==0) or 8 (neg==1), meaning that if we have accumulated
61 * a value > 214748364, or equal but the next digit is > 7 (or 8),
62 * the number is too big, and we will return a range error.
63 *
64 * Set any if any `digits' consumed; make it negative to indicate
65 * overflow.
66 */
67 cutoff = neg ? ((unsigned long)LONG_MAX+1) : LONG_MAX;
68 cutlim = cutoff % (unsigned long)base;
69 cutoff /= (unsigned long)base;
70 for (acc = 0, any = 0;; c = *s++)
71 {
72 if (iswctype(c, _DIGIT))
73 c -= L'0';
74 else if (iswctype(c, _ALPHA))
75 c -= iswctype(c, _UPPER) ? L'A' - 10 : L'a' - 10;
76 else
77 break;
78 if (c >= base)
79 break;
80 if (any < 0 || (unsigned long)acc > cutoff || (acc == cutoff && c > cutlim))
81 any = -1;
82 else
83 {
84 any = 1;
85 acc *= base;
86 acc += c;
87 }
88 }
89 if (any < 0)
90 {
91 acc = neg ? LONG_MIN : LONG_MAX;
92 }
93 else if (neg)
94 acc = 0-acc;
95 if (endptr != 0)
96 *endptr = any ? (wchar_t *)((size_t)(s - 1)) : (wchar_t *)((size_t)nptr);
97 return acc;
98}
#define CDECL
Definition: compat.h:29
int __cdecl iswctype(wint_t wc, wctype_t wctypeFlags)
Definition: freeldr.c:100
GLdouble s
Definition: gl.h:2039
const GLubyte * c
Definition: glext.h:8905
#define _SPACE
Definition: ctype.h:68
#define _ALPHA
Definition: ctype.h:76
#define _UPPER
Definition: ctype.h:65
#define _DIGIT
Definition: ctype.h:67
#define LONG_MAX
Definition: limits.h:43
#define LONG_MIN
Definition: limits.h:42
#define c
Definition: ke_i.h:80
#define L(x)
Definition: ntvdm.h:50
#define long
Definition: qsort.c:33
long CDECL wcstol(const wchar_t *nptr, wchar_t **endptr, int base)
Definition: wcstol.c:17