[UCRT] Import Microsoft.Windows.SDK.CRTSource version 10.0.22621.3

Imported from https://www.nuget.org/packages/Microsoft.Windows.SDK.CRTSource/10.0.22621.3
License: MIT

sdk/lib/ucrt/convert/mbtowc.cpp

@@ -0,0 +1,153 @@
+/***
+*mbtowc.c - Convert multibyte char to wide char.
+*
+*       Copyright (c) Microsoft Corporation. All rights reserved.
+*
+*Purpose:
+*       Convert a multibyte character into the equivalent wide character.
+*
+*******************************************************************************/
+#include <corecrt_internal_mbstring.h>
+#include <corecrt_internal_ptd_propagation.h>
+#include <locale.h>
+#include <stdlib.h>
+#include <wchar.h>
+
+using namespace __crt_mbstring;
+
+/***
+*int mbtowc() - Convert multibyte char to wide character.
+*
+*Purpose:
+*       Convert a multi-byte character into the equivalent wide character,
+*       according to the LC_CTYPE category of the current locale.
+*       [ANSI].
+*
+*       NOTE:  Currently, the C libraries support the "C" locale only.
+*              Non-C locale support now available under _INTL switch.
+*Entry:
+*       wchar_t  *pwc = pointer to destination wide character
+*       const char *s = pointer to multibyte character
+*       size_t      n = maximum length of multibyte character to consider
+*
+*Exit:
+*       If s = nullptr, returns 0, indicating we only use state-independent
+*       character encodings.
+*       If s != nullptr, returns:  0 (if *s = null char)
+*                               -1 (if the next n or fewer bytes not valid mbc)
+*                               number of bytes comprising converted mbc
+*
+*Exceptions:
+*       If errors are encountered, -1 is returned and errno is set to EILSEQ.
+*
+*******************************************************************************/
+
+extern "C" int __cdecl _mbtowc_internal(
+    wchar_t *              pwc,
+    const char *           s,
+    size_t                 n,
+    __crt_cached_ptd_host& ptd
+    )
+{
+    static mbstate_t internal_state{};
+    if (!s || n == 0)
+    {
+        /* indicate do not have state-dependent encodings,
+        handle zero length string */
+        internal_state = {};
+        return 0;
+    }
+
+    if (!*s)
+    {
+        /* handle NULL char */
+        if (pwc)
+        {
+            *pwc = 0;
+        }
+        return 0;
+    }
+
+    const _locale_t locale = ptd.get_locale();
+
+    if (locale->locinfo->_public._locale_lc_codepage == CP_UTF8)
+    {
+        int result = static_cast<int>(__mbrtowc_utf8(pwc, s, n, &internal_state, ptd));
+        if (result < 0)
+            result = -1;
+        return result;
+    }
+
+    _ASSERTE(locale->locinfo->_public._locale_mb_cur_max == 1 ||
+             locale->locinfo->_public._locale_mb_cur_max == 2);
+
+    if (locale->locinfo->locale_name[LC_CTYPE] == nullptr)
+    {
+        if (pwc)
+        {
+            *pwc = (wchar_t) (unsigned char) *s;
+        }
+        return sizeof(char);
+    }
+
+    if (_isleadbyte_fast_internal((unsigned char) *s, locale))
+    {
+        _ASSERTE(locale->locinfo->_public._locale_lc_codepage != CP_UTF8 && L"UTF-8 isn't supported in this _mbtowc_l function yet!!!");
+
+        /* multi-byte char */
+        // If this is a lead byte, then the codepage better be a multibyte codepage
+        _ASSERTE(locale->locinfo->_public._locale_mb_cur_max > 1);
+
+        if ((locale->locinfo->_public._locale_mb_cur_max <= 1) || ((int) n < locale->locinfo->_public._locale_mb_cur_max) ||
+            (__acrt_MultiByteToWideChar(locale->locinfo->_public._locale_lc_codepage,
+            MB_PRECOMPOSED | MB_ERR_INVALID_CHARS,
+            s,
+            locale->locinfo->_public._locale_mb_cur_max,
+            pwc,
+            (pwc) ? 1 : 0) == 0))
+        {
+            /* validate high byte of mbcs char */
+            if ((n < (size_t) locale->locinfo->_public._locale_mb_cur_max) || (!*(s + 1)))
+            {
+                ptd.get_errno().set(EILSEQ);
+                return -1;
+            }
+        }
+        return locale->locinfo->_public._locale_mb_cur_max;
+    }
+    else {
+        /* single byte char */
+        if (__acrt_MultiByteToWideChar(locale->locinfo->_public._locale_lc_codepage,
+            MB_PRECOMPOSED | MB_ERR_INVALID_CHARS,
+            s,
+            1,
+            pwc,
+            (pwc) ? 1 : 0) == 0)
+        {
+            ptd.get_errno().set(EILSEQ);
+            return -1;
+        }
+        return sizeof(char);
+    }
+}
+
+extern "C" int __cdecl _mbtowc_l(
+    wchar_t  *pwc,
+    const char *s,
+    size_t n,
+    _locale_t plocinfo
+    )
+{
+    __crt_cached_ptd_host ptd(plocinfo);
+    return _mbtowc_internal(pwc, s, n, ptd);
+}
+
+extern "C" int __cdecl mbtowc(
+    wchar_t  *pwc,
+    const char *s,
+    size_t n
+    )
+{
+    __crt_cached_ptd_host ptd;
+    return _mbtowc_internal(pwc, s, n, ptd);
+}