1 /**
2 * This file has no copyright assigned and is placed in the Public Domain.
3 * This file is part of the mingw-w64 runtime package.
4 * No warranty is given; refer to the file DISCLAIMER.PD within this package.
5 */
6 /*
7 This source code was extracted from the Q8 package created and
8 placed in the PUBLIC DOMAIN by Doug Gwyn <gwyn@arl.mil>
9 last edit: 1999/11/05 gwyn@arl.mil
10
11 Implements subclause 7.8.2 of ISO/IEC 9899:1999 (E).
12
13 This particular implementation requires the matching <inttypes.h>.
14 It also assumes that character codes for A..Z and a..z are in
15 contiguous ascending order; this is true for ASCII but not EBCDIC.
16 */
17 #include <stdlib.h>
18 #include <errno.h>
19 #include <ctype.h>
20 #include <inttypes.h>
21
22 /* Helper macros */
23
24 /* convert digit character to number, in any base */
25 #define ToNumber(c) (isdigit(c) ? (c) - '0' : \
26 isupper(c) ? (c) - 'A' + 10 : \
27 islower(c) ? (c) - 'a' + 10 : \
28 -1 /* "invalid" flag */ \
29 )
30 /* validate converted digit character for specific base */
31 #define valid(n, b) ((n) >= 0 && (n) < (b))
32
33 uintmax_t
strtoumax(nptr,endptr,base)34 strtoumax(nptr, endptr, base)
35 register const char * __restrict__ nptr;
36 char ** __restrict__ endptr;
37 register int base;
38 {
39 register uintmax_t accum; /* accumulates converted value */
40 register uintmax_t next; /* for computing next value of accum */
41 register int n; /* numeral from digit character */
42 int minus; /* set iff minus sign seen (yes!) */
43 int toobig; /* set iff value overflows */
44
45 if ( endptr != NULL )
46 *endptr = (char *)nptr; /* in case no conversion's performed */
47
48 if ( base < 0 || base == 1 || base > 36 )
49 {
50 errno = EDOM;
51 return 0; /* unspecified behavior */
52 }
53
54 /* skip initial, possibly empty sequence of white-space characters */
55
56 while ( isspace(*nptr) )
57 ++nptr;
58
59 /* process subject sequence: */
60
61 /* optional sign (yes!) */
62
63 if ( (minus = *nptr == '-') || *nptr == '+' )
64 ++nptr;
65
66 if ( base == 0 )
67 {
68 if ( *nptr == '0' )
69 {
70 if ( nptr[1] == 'X' || nptr[1] == 'x' )
71 base = 16;
72 else
73 base = 8;
74 }
75 else
76 base = 10;
77 }
78
79 /* optional "0x" or "0X" for base 16 */
80
81 if ( base == 16 && *nptr == '0' && (nptr[1] == 'X' || nptr[1] == 'x') )
82 nptr += 2; /* skip past this prefix */
83
84 /* check whether there is at least one valid digit */
85
86 n = ToNumber(*nptr);
87 ++nptr;
88
89 if ( !valid(n, base) )
90 return 0; /* subject seq. not of expected form */
91
92 accum = n;
93
94 for ( toobig = 0; n = ToNumber(*nptr), valid(n, base); ++nptr )
95 if ( accum > UINTMAX_MAX / base + 1 /* major wrap-around */
96 || (next = base * accum + n) < accum /* minor wrap-around */
97 )
98 toobig = 1; /* but keep scanning */
99 else
100 accum = next;
101
102 if ( endptr != NULL )
103 *endptr = (char *)nptr; /* points to first not-valid-digit */
104
105 if ( toobig )
106 {
107 errno = ERANGE;
108 return UINTMAX_MAX;
109 }
110 else
111 return minus ? -accum : accum; /* (yes!) */
112 }
113
114 unsigned long long __attribute__ ((alias ("strtoumax")))
115 strtoull (const char* __restrict__ nptr, char ** __restrict__ endptr, int base);
116