[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/towupper.cpp

@@ -0,0 +1,105 @@
+/***
+*towupper.cpp - convert wide character to upper case
+*
+*       Copyright (c) Microsoft Corporation. All rights reserved.
+*
+*Purpose:
+*       Defines towupper().
+*
+*******************************************************************************/
+#include <corecrt_internal.h>
+#include <ctype.h>
+#include <locale.h>
+
+/***
+*wint_t _towupper_l(c, ptloci) - convert wide character to upper case
+*
+*Purpose:
+*       Multi-thread function only! Non-locking version of towupper.
+*
+*Entry:
+*
+*Exit:
+*
+*Exceptions:
+*
+*******************************************************************************/
+
+extern "C" wint_t __cdecl _towupper_l(
+        wint_t const c,
+        _locale_t const plocinfo
+        )
+{
+    if (c == WEOF)
+    {
+        return c;
+    }
+
+    _LocaleUpdate _loc_update(plocinfo);
+    auto const locinfo = _loc_update.GetLocaleT()->locinfo;
+
+    if (locinfo->_public._locale_lc_codepage == CP_UTF8)
+    {
+        // For 128 <= c < 256, the toupper map would consider the wide character as it is in UTF-8, not UTF-16.
+        // Below 128, UTF-8 and UTF-16 have the same encodings, so we can use the table.
+        if (c < 128)
+        {
+            return _towupper_fast_internal(static_cast<unsigned char>(c), _loc_update.GetLocaleT());
+        }
+    }
+    else
+    {
+        // For 128 <= c < 256, the toupper map will consider the wide character as it would be in the current narrow code page,
+        // which can lead to unexpected behavior. This behavior is maintained for backwards compatibility.
+        if (c < 256)
+        {
+            return _towupper_fast_internal(static_cast<unsigned char>(c), _loc_update.GetLocaleT());
+        }
+
+        if (locinfo->locale_name[LC_CTYPE] == nullptr)
+        {
+            // If the locale is C, then the only characters that would be transformed are <256
+            // and have been processed already.
+            return c;
+        }
+    }
+
+    wint_t widechar;
+    if (0 == __acrt_LCMapStringW(
+                locinfo->locale_name[LC_CTYPE],
+                LCMAP_UPPERCASE,
+                (LPCWSTR)&c,
+                1,
+                (LPWSTR)&widechar,
+                1))
+    {
+        return c;
+    }
+
+    return widechar;
+}
+
+/***
+*wint_t towupper(c) - convert wide character to upper case
+*
+*Purpose:
+*       towupper() returns the uppercase equivalent of its argument
+*
+*Entry:
+*       c - wint_t value of character to be converted
+*
+*Exit:
+*       if c is a lower case letter, returns wint_t value of upper case
+*       representation of c. otherwise, it returns c.
+*
+*Exceptions:
+*
+*******************************************************************************/
+
+extern "C" wint_t __cdecl towupper (
+        wint_t c
+        )
+{
+
+    return _towupper_l(c, nullptr);
+}