GetSystemWow64Directory2W

// api-ms-win-core-wow64-l1-1-1.dll  (Unicode / -W)
#include <windows.h>

DWORD GetSystemWow64Directory2W(
    LPWSTR lpBuffer,   // optional
    DWORD uSize,
    IMAGE_FILE_MACHINE ImageFileMachineType
);

<DllImport("api-ms-win-core-wow64-l1-1-1.dll", CharSet:=CharSet.Unicode, SetLastError:=True, ExactSpelling:=True)>
Public Shared Function GetSystemWow64Directory2W(
    <MarshalAs(UnmanagedType.LPWStr)> lpBuffer As System.Text.StringBuilder,   ' LPWSTR optional, out
    uSize As UInteger,   ' DWORD
    ImageFileMachineType As UShort   ' IMAGE_FILE_MACHINE
) As UInteger
End Function

' lpBuffer : LPWSTR optional, out
' uSize : DWORD
' ImageFileMachineType : IMAGE_FILE_MACHINE
Declare PtrSafe Function GetSystemWow64Directory2W Lib "api-ms-win-core-wow64-l1-1-1" ( _
    ByVal lpBuffer As LongPtr, _
    ByVal uSize As Long, _
    ByVal ImageFileMachineType As Integer) As Long
' Unicode(W): 文字列は ByVal As LongPtr とし StrPtr(unicodeStr) を渡す
' VBA7前提(PtrSafe)。32bit Office では LongPtr→Long。Integer=16bit / Long=32bit / LongLong=64bit。

import ctypes
from ctypes import wintypes

GetSystemWow64Directory2W = ctypes.windll.LoadLibrary("api-ms-win-core-wow64-l1-1-1.dll").GetSystemWow64Directory2W
GetSystemWow64Directory2W.restype = wintypes.DWORD
GetSystemWow64Directory2W.argtypes = [
    wintypes.LPWSTR,  # lpBuffer : LPWSTR optional, out
    wintypes.DWORD,  # uSize : DWORD
    ctypes.c_ushort,  # ImageFileMachineType : IMAGE_FILE_MACHINE
]
# GetLastError: use ctypes.GetLastError() (or ctypes.WinDLL(use_last_error=True))

require 'fiddle'
require 'fiddle/import'

lib = Fiddle.dlopen('api-ms-win-core-wow64-l1-1-1.dll')
GetSystemWow64Directory2W = Fiddle::Function.new(
  lib['GetSystemWow64Directory2W'],
  [
    Fiddle::TYPE_VOIDP,  # lpBuffer : LPWSTR optional, out
    -Fiddle::TYPE_INT,  # uSize : DWORD
    -Fiddle::TYPE_SHORT,  # ImageFileMachineType : IMAGE_FILE_MACHINE
  ],
  -Fiddle::TYPE_INT)
# Wide strings: pass str.encode("UTF-16LE") + "\x00\x00"

#[link(name = "api-ms-win-core-wow64-l1-1-1")]
extern "system" {
    fn GetSystemWow64Directory2W(
        lpBuffer: *mut u16,  // LPWSTR optional, out
        uSize: u32,  // DWORD
        ImageFileMachineType: u16  // IMAGE_FILE_MACHINE
    ) -> u32;
}
// crates: windows-sys provides ready-made bindings for this API.

$sig = @"
[DllImport("api-ms-win-core-wow64-l1-1-1.dll", CharSet = CharSet.Unicode, SetLastError = true)]
public static extern uint GetSystemWow64Directory2W([MarshalAs(UnmanagedType.LPWStr)] System.Text.StringBuilder lpBuffer, uint uSize, ushort ImageFileMachineType);
"@
$api = Add-Type -MemberDefinition $sig -Name 'api-ms-win-core-wow64-l1-1-1_GetSystemWow64Directory2W' -Namespace Win32 -PassThru
# $api::GetSystemWow64Directory2W(lpBuffer, uSize, ImageFileMachineType)

#uselib "api-ms-win-core-wow64-l1-1-1.dll"
#func global GetSystemWow64Directory2W "GetSystemWow64Directory2W" wptr, wptr, wptr
; GetSystemWow64Directory2W varptr(lpBuffer), uSize, ImageFileMachineType   ; 戻り値は stat
; lpBuffer : LPWSTR optional, out -> "wptr"
; uSize : DWORD -> "wptr"
; ImageFileMachineType : IMAGE_FILE_MACHINE -> "wptr"
; ※HSP3.7は #func のため戻り値はシステム変数 stat に格納されます。

#uselib "api-ms-win-core-wow64-l1-1-1.dll"
#cfunc global GetSystemWow64Directory2W "GetSystemWow64Directory2W" var, int, int
; res = GetSystemWow64Directory2W(lpBuffer, uSize, ImageFileMachineType)
; lpBuffer : LPWSTR optional, out -> "var"
; uSize : DWORD -> "int"
; ImageFileMachineType : IMAGE_FILE_MACHINE -> "int"
; ※出力/バッファ引数は var 方式(変数を直接渡す)。varptr 方式にも切替可。

; DWORD GetSystemWow64Directory2W(LPWSTR lpBuffer, DWORD uSize, IMAGE_FILE_MACHINE ImageFileMachineType)
#uselib "api-ms-win-core-wow64-l1-1-1.dll"
#cfunc global GetSystemWow64Directory2W "GetSystemWow64Directory2W" var, int, int
; res = GetSystemWow64Directory2W(lpBuffer, uSize, ImageFileMachineType)
; lpBuffer : LPWSTR optional, out -> "var"
; uSize : DWORD -> "int"
; ImageFileMachineType : IMAGE_FILE_MACHINE -> "int"
; ※出力/バッファ引数は var 方式(変数を直接渡す)。varptr 方式にも切替可。

import (
	"golang.org/x/sys/windows"
	"unsafe"
)

var (
	api_ms_win_core_wow64_l1_1_1 = windows.NewLazySystemDLL("api-ms-win-core-wow64-l1-1-1.dll")
	procGetSystemWow64Directory2W = api_ms_win_core_wow64_l1_1_1.NewProc("GetSystemWow64Directory2W")
)

// lpBuffer (LPWSTR optional, out), uSize (DWORD), ImageFileMachineType (IMAGE_FILE_MACHINE)
r1, _, err := procGetSystemWow64Directory2W.Call(
	uintptr(lpBuffer),
	uintptr(uSize),
	uintptr(ImageFileMachineType),
)
_ = err  // syscall.Errno (valid when the call sets last-error)
_ = r1   // DWORD

function GetSystemWow64Directory2W(
  lpBuffer: PWideChar;   // LPWSTR optional, out
  uSize: DWORD;   // DWORD
  ImageFileMachineType: Word   // IMAGE_FILE_MACHINE
): DWORD; stdcall;
  external 'api-ms-win-core-wow64-l1-1-1.dll' name 'GetSystemWow64Directory2W';

result := DllCall("api-ms-win-core-wow64-l1-1-1\GetSystemWow64Directory2W"
    , "Ptr", lpBuffer   ; LPWSTR optional, out
    , "UInt", uSize   ; DWORD
    , "UShort", ImageFileMachineType   ; IMAGE_FILE_MACHINE
    , "UInt")   ; return: DWORD

●GetSystemWow64Directory2W(lpBuffer, uSize, ImageFileMachineType) = DLL("api-ms-win-core-wow64-l1-1-1.dll", "dword GetSystemWow64Directory2W(char*, dword, int)")
# 呼び出し: GetSystemWow64Directory2W(lpBuffer, uSize, ImageFileMachineType)
# lpBuffer : LPWSTR optional, out -> "char*"
# uSize : DWORD -> "dword"
# ImageFileMachineType : IMAGE_FILE_MACHINE -> "int"
# なでしこ1は32bit・ANSI(Shift_JIS)。文字列=char*(ANSI)、ポインタ/ハンドル=void*(4byte)。
# ※-W(Unicode)関数。なでしこ1はANSIのため -A 版の利用を推奨。