sdcc/device/lib/wcstoul.c

   1 /*---------------------------------------------------------------------
   2    wcstoul() - convert a wide string to a unsigned long int and return it
   3
   4    Copyright (C) 2018-2023, Philipp Klaus Krause . krauseph@informatik.uni-freiburg.de
   5                  2023, Benedikt Freisen . b.freisen@gmx.net
   6
   7    This library is free software; you can redistribute it and/or modify it
   8    under the terms of the GNU General Public License as published by the
   9    Free Software Foundation; either version 2, or (at your option) any
  10    later version.
  11
  12    This library is distributed in the hope that it will be useful,
  13    but WITHOUT ANY WARRANTY; without even the implied warranty of
  14    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15    GNU General Public License for more details.
  16
  17    You should have received a copy of the GNU General Public License
  18    along with this library; see the file COPYING. If not, write to the
  19    Free Software Foundation, 51 Franklin Street, Fifth Floor, Boston,
  20    MA 02110-1301, USA.
  21
  22    As a special exception, if you link this library with other files,
  23    some of which are compiled with SDCC, to produce an executable,
  24    this library does not by itself cause the resulting executable to
  25    be covered by the GNU General Public License. This exception does
  26    not however invalidate any other reasons why the executable file
  27    might be covered by the GNU General Public License.
  28 -------------------------------------------------------------------------*/
  29
  30 #include <stdlib.h>
  31
  32 #include <stdbool.h>
  33 #include <ctype.h>
  34 #include <string.h>
  35 #if !defined(__SDCC_pic14) && !defined(__SDCC_pic16)
  36 #include <stdckdint.h>
  37 #endif
  38 #include <limits.h>
  39 #include <errno.h>
  40 #include <wchar.h>
  41
  42 static signed char _isdigit(const wchar_t c, unsigned char base)
  43 {
  44   unsigned char v;
  45
  46   if (c >= L'0' && c <= L'9')
  47     v = c - L'0';
  48   else if (c >= L'a' && c <= L'z')
  49     v = c - L'a' + 10;
  50   else if (c >= L'A' && c <= L'Z')
  51     v = c - L'A' + 10;
  52   else
  53     return (-1);
  54
  55   if (v >= base)
  56     return (-1);
  57
  58   return (v);
  59 }
  60
  61 // NOTE for maintenance: strtoull, wcstoul and wcstoull have been derived from strtoul
  62
  63 unsigned long int wcstoul(const wchar_t *nptr, wchar_t **endptr, int base)
  64 {
  65   const wchar_t *ptr = nptr;
  66   unsigned long int ret;
  67   bool range_error = false;
  68   bool neg = false;
  69   unsigned char b = base;
  70
  71   while (iswblank (*ptr))
  72     ptr++;
  73
  74   // Handle sign.
  75   switch(*ptr)
  76     {
  77     case L'-':
  78       neg = true;
  79     case L'+':
  80       ptr++;
  81     }
  82
  83   // base not specified.
  84   if (!b)
  85     {
  86       if (!wcsncmp (ptr, L"0x", 2) || !wcsncmp (ptr, L"0X", 2))
  87         {
  88           b = 16;
  89           ptr += 2;
  90         }
  91       else if (!wcsncmp (ptr, L"0b", 2) || !wcsncmp (ptr, L"0B", 2))
  92         {
  93           b = 2;
  94           ptr += 2;
  95         }
  96       else if (*ptr == L'0')
  97         {
  98           b = 8;
  99           ptr++;
 100         }
 101       else
 102         b = 10;
 103     }
 104   // Handle optional hex prefix.
 105   else if (b == 16 && (!wcsncmp (ptr, L"0x", 2) || !wcsncmp (ptr, L"0X", 2)))
 106     ptr += 2;
 107   else if (b == 2 && (!wcsncmp (ptr, L"0b", 2) || !wcsncmp (ptr, L"0B", 2)))
 108     ptr += 2;
 109
 110   // Empty sequence conversion error
 111   if (_isdigit (*ptr, b) < 0)
 112     {
 113       if (endptr)
 114         *endptr = (wchar_t*)nptr;
 115       return (0);
 116     }
 117
 118   for (ret = 0;; ptr++)
 119     {
 120       signed char digit = _isdigit (*ptr, b);
 121
 122       if (digit < 0)
 123         break;
 124
 125 #if !defined(__SDCC_pic14) && !defined(__SDCC_pic16)
 126       range_error |= ckd_mul (&ret, ret, b);
 127       range_error |= ckd_add (&ret, ret, digit);
 128 #else
 129       unsigned long int oldret = ret;
 130       ret *= b;
 131       if (ret < oldret)
 132         range_error = true;
 133       ret += (unsigned char)digit;
 134 #warning INEXACT RANGE ERROR CHECK WILL NOT REPORT ALL OVERFLOWS (fix by implementing ckd_mul support)
 135 #endif
 136     }
 137
 138   if (endptr)
 139     *endptr = (wchar_t*)ptr;
 140
 141   if (range_error)
 142     {
 143       errno = ERANGE;
 144       return (ULONG_MAX);
 145     }
 146
 147   return (neg ? -ret : ret);
 148 }
 149