[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/misc/chdir.cpp

@@ -0,0 +1,109 @@
+/***
+*chdir.c - change directory
+*
+*       Copyright (c) Microsoft Corporation. All rights reserved.
+*
+*Purpose:
+*       This file has the _chdir() function - change current directory.
+*
+*******************************************************************************/
+
+#include <direct.h>
+#include <corecrt_internal_traits.h>
+#include <corecrt_internal_win32_buffer.h>
+#include <malloc.h>
+#include <stdlib.h>
+
+/***
+*int _chdir(path) - change current directory
+*
+*Purpose:
+*       Changes the current working directory to that given in path.
+*
+*Entry:
+*       _TSCHAR *path - directory to change to
+*
+*Exit:
+*       returns 0 if successful,
+*       returns -1 and sets errno if unsuccessful
+*
+*Exceptions:
+*
+*******************************************************************************/
+template <typename Character>
+_Success_(return == 0)
+static int __cdecl set_cwd_environment_variable(_In_z_ Character const* const path) throw()
+{
+    typedef __crt_char_traits<Character> traits;
+
+    // If the path is a UNC name, no need to update:
+    if ((path[0] == '\\' || path[0] == '/') && path[0] == path[1])
+        return 0;
+
+#pragma warning(suppress:28931) // unused assignment of variable drive_letter
+    Character const drive_letter = static_cast<Character>(toupper(static_cast<char>(path[0])));
+    Character const name[] = { '=', drive_letter, ':', '\0' };
+
+    if (traits::set_environment_variable(name, path))
+        return 0;
+
+    __acrt_errno_map_os_error(GetLastError());
+    return -1;
+}
+
+
+
+template <typename Character>
+_Success_(return == 0)
+static int __cdecl common_chdir(_In_z_ Character const* const path) throw()
+{
+    typedef __crt_char_traits<Character> traits;
+
+    _VALIDATE_CLEAR_OSSERR_RETURN(path != nullptr, EINVAL, -1);
+
+    if (!traits::set_current_directory(path))
+    {
+        __acrt_errno_map_os_error(GetLastError());
+        return -1;
+    }
+
+    // If the new current directory path is not a UNC path, we must update the
+    // OS environment variable specifying the current full current directory,
+    // build the environment variable string, and call SetEnvironmentVariable().
+    // We need to do this because the SetCurrentDirectory() API does not update
+    // the environment variables, and other functions (fullpath, spawn, etc.)
+    // need them to be set.
+    //
+    // If associated with a 'drive', the current directory should have the
+    // form of the example below:
+    //
+    //     D:\nt\private\mytests
+    //
+    // So that the environment variable should be of the form:
+    //
+    //     =D:=D:\nt\private\mytests
+
+    Character buffer_initial_storage[MAX_PATH + 1];
+    __crt_internal_win32_buffer<Character> current_directory_buffer(buffer_initial_storage);
+
+    errno_t const err = traits::get_current_directory(current_directory_buffer);
+
+    if (err != 0) {
+        // Appropriate error already set
+        return -1;
+    }
+
+    return set_cwd_environment_variable(current_directory_buffer.data());
+}
+
+
+
+extern "C" int __cdecl _chdir(char const* const path)
+{
+    return common_chdir(path);
+}
+
+extern "C" int __cdecl _wchdir(wchar_t const* const path)
+{
+    return common_chdir(path);
+}