1 /***
2 *wcsicmp.cpp - contains case-insensitive wide string comp routine _wcsicmp
3 *
4 * Copyright (c) Microsoft Corporation. All rights reserved.
5 *
6 *Purpose:
7 * contains _wcsicmp()
8 *
9 *******************************************************************************/
10 #include <corecrt_internal.h>
11 #include <ctype.h>
12 #include <locale.h>
13 #include <string.h>
14
15 #pragma warning(disable:__WARNING_POTENTIAL_BUFFER_OVERFLOW_NULLTERMINATED) // 26018 Prefast can't see that we are checking for terminal nul.
16
17 /***
18 *int _wcsicmp(lhs, rhs) - compare wide-character strings, ignore case
19 *
20 *Purpose:
21 * _wcsicmp performs a case-insensitive wchar_t string comparision.
22 * _wcsicmp is independent of locale.
23 *
24 *Entry:
25 * wchar_t *lhs, *rhs - strings to compare
26 *
27 *Return:
28 * Returns <0 if lhs < rhs
29 * Returns 0 if lhs = rhs
30 * Returns >0 if lhs > rhs
31 * Returns _NLSCMPERROR if something went wrong
32 * This range of return values may differ from other *cmp/*coll functions.
33 *
34 *Exceptions:
35 * Input parameters are validated. Refer to the validation section of the function.
36 *
37 *******************************************************************************/
38
_wcsicmp_l(wchar_t const * const lhs,wchar_t const * const rhs,_locale_t const plocinfo)39 extern "C" int __cdecl _wcsicmp_l (
40 wchar_t const * const lhs,
41 wchar_t const * const rhs,
42 _locale_t const plocinfo
43 )
44 {
45 /* validation section */
46 _VALIDATE_RETURN(lhs != nullptr, EINVAL, _NLSCMPERROR);
47 _VALIDATE_RETURN(rhs != nullptr, EINVAL, _NLSCMPERROR);
48
49 _LocaleUpdate _loc_update(plocinfo);
50
51 // This check is still worth doing for wide but not narrow because
52 // we need to consult the UTF-16 ctype map for towlower operations.
53 if (_loc_update.GetLocaleT()->locinfo->locale_name[LC_CTYPE] == nullptr)
54 {
55 return __ascii_wcsicmp(lhs, rhs);
56 }
57
58 unsigned short const * lhs_ptr = reinterpret_cast<unsigned short const *>(lhs);
59 unsigned short const * rhs_ptr = reinterpret_cast<unsigned short const *>(rhs);
60
61 int result;
62 int lhs_value;
63 int rhs_value;
64 do
65 {
66 lhs_value = _towlower_internal(*lhs_ptr++, _loc_update.GetLocaleT());
67 rhs_value = _towlower_internal(*rhs_ptr++, _loc_update.GetLocaleT());
68 result = lhs_value - rhs_value;
69 }
70 while (result == 0 && lhs_value != 0);
71
72 return result;
73 }
74
__ascii_wcsicmp(wchar_t const * const lhs,wchar_t const * const rhs)75 extern "C" int __cdecl __ascii_wcsicmp(
76 wchar_t const * const lhs,
77 wchar_t const * const rhs
78 )
79 {
80 unsigned short const * lhs_ptr = reinterpret_cast<unsigned short const *>(lhs);
81 unsigned short const * rhs_ptr = reinterpret_cast<unsigned short const *>(rhs);
82
83 int result;
84 int lhs_value;
85 int rhs_value;
86 do
87 {
88 lhs_value = __ascii_towlower(*lhs_ptr++);
89 rhs_value = __ascii_towlower(*rhs_ptr++);
90 result = lhs_value - rhs_value;
91 }
92 while (result == 0 && lhs_value != 0);
93
94 return result;
95 }
96
_wcsicmp(wchar_t const * const lhs,wchar_t const * const rhs)97 extern "C" int __cdecl _wcsicmp(
98 wchar_t const * const lhs,
99 wchar_t const * const rhs
100 )
101 {
102 if (!__acrt_locale_changed())
103 {
104 /* validation section */
105 _VALIDATE_RETURN(lhs != nullptr, EINVAL, _NLSCMPERROR);
106 _VALIDATE_RETURN(rhs != nullptr, EINVAL, _NLSCMPERROR);
107
108 return __ascii_wcsicmp(lhs, rhs);
109 }
110
111 return _wcsicmp_l(lhs, rhs, nullptr);
112 }
113