[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/string/wcstok_s.cpp

@@ -0,0 +1,83 @@
+//
+// wcstok_s.cpp
+//
+//      Copyright (c) Microsoft Corporation.  All rights reserved.
+//
+// Defines wcstok_s(), which tokenizes a string via repeated calls.  See strtok()
+// for more details.  This more secure function uses a caller-provided context
+// instead of the thread-local tokenization state.
+//
+#include <corecrt_internal_securecrt.h>
+#include <string.h>
+
+
+
+// This common implementation is used by both strtok() and strtok_s()
+extern "C" wchar_t* __cdecl __acrt_wcstok_s_novalidation(
+    _Inout_opt_z_                 wchar_t*       string,
+    _In_z_                        wchar_t const* control,
+    _Inout_ _Deref_prepost_opt_z_ wchar_t**      context
+    )
+{
+    // If string is null, set the iterator to the saved pointer (i.e., continue
+    // breaking tokens out of the string from the last strtok call):
+    wchar_t* string_it = string != nullptr
+        ? string
+        : *context;
+
+
+    // Find beginning of token (skip over leading delimiters). Note that
+    // there is no token iff this loop sets string to point to the terminal
+    // null (*string == '\0')
+    while (*string_it)
+    {
+        wchar_t const* control_it = control;
+        for (; *control_it && *control_it != *string_it; ++control_it)
+        {
+        }
+
+        if (!*control_it)
+            break;
+
+        ++string_it;
+    }
+
+    wchar_t* const token_first = string_it;
+
+    // Find the end of the token.  If it is not the end of the string, put a
+    // null character there:
+    for (; *string_it; ++string_it)
+    {
+        wchar_t const* control_it = control;
+        for (; *control_it && *control_it != *string_it; ++control_it)
+        {
+        }
+
+        if (*control_it)
+        {
+            *string_it++ = '\0';
+            break;
+        }
+    }
+
+    // Update the saved pointer:
+    *context = string_it;
+
+    // Determine if a token has been found.
+    return string_it != token_first ? token_first : nullptr;
+}
+
+
+
+extern "C" wchar_t* __cdecl wcstok_s(
+    wchar_t*       const string,
+    wchar_t const* const control,
+    wchar_t**      const context
+    )
+{
+    _VALIDATE_POINTER_ERROR_RETURN(context, EINVAL, nullptr);
+    _VALIDATE_POINTER_ERROR_RETURN(control, EINVAL, nullptr);
+    _VALIDATE_CONDITION_ERROR_RETURN(string != nullptr || *context != nullptr, EINVAL, nullptr);
+
+    return __acrt_wcstok_s_novalidation(string, control, context);
+}