VarI8FromDec

// OLEAUT32.dll
#include <windows.h>

HRESULT VarI8FromDec(
    const DECIMAL* pdecIn,
    LONGLONG* pi64Out
);

<DllImport("OLEAUT32.dll", ExactSpelling:=True)>
Public Shared Function VarI8FromDec(
    pdecIn As IntPtr,   ' DECIMAL*
    <Out> ByRef pi64Out As Long   ' LONGLONG* out
) As Integer
End Function

' pdecIn : DECIMAL*
' pi64Out : LONGLONG* out
Declare PtrSafe Function VarI8FromDec Lib "oleaut32" ( _
    ByVal pdecIn As LongPtr, _
    ByRef pi64Out As LongLong) As Long
' VBA7前提(PtrSafe)。32bit Office では LongPtr→Long。Integer=16bit / Long=32bit / LongLong=64bit。

import ctypes
from ctypes import wintypes

VarI8FromDec = ctypes.windll.oleaut32.VarI8FromDec
VarI8FromDec.restype = ctypes.c_int
VarI8FromDec.argtypes = [
    ctypes.c_void_p,  # pdecIn : DECIMAL*
    ctypes.POINTER(ctypes.c_longlong),  # pi64Out : LONGLONG* out
]

require 'fiddle'
require 'fiddle/import'

lib = Fiddle.dlopen('OLEAUT32.dll')
VarI8FromDec = Fiddle::Function.new(
  lib['VarI8FromDec'],
  [
    Fiddle::TYPE_VOIDP,  # pdecIn : DECIMAL*
    Fiddle::TYPE_VOIDP,  # pi64Out : LONGLONG* out
  ],
  Fiddle::TYPE_INT)

#[link(name = "oleaut32")]
extern "system" {
    fn VarI8FromDec(
        pdecIn: *const DECIMAL,  // DECIMAL*
        pi64Out: *mut i64  // LONGLONG* out
    ) -> i32;
}
// crates: windows-sys provides ready-made bindings for this API.

$sig = @"
[DllImport("OLEAUT32.dll")]
public static extern int VarI8FromDec(IntPtr pdecIn, out long pi64Out);
"@
$api = Add-Type -MemberDefinition $sig -Name 'OLEAUT32_VarI8FromDec' -Namespace Win32 -PassThru
# $api::VarI8FromDec(pdecIn, pi64Out)

#uselib "OLEAUT32.dll"
#func global VarI8FromDec "VarI8FromDec" sptr, sptr
; VarI8FromDec varptr(pdecIn), varptr(pi64Out)   ; 戻り値は stat
; pdecIn : DECIMAL* -> "sptr"
; pi64Out : LONGLONG* out -> "sptr"
; ※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。

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

var (
	oleaut32 = windows.NewLazySystemDLL("OLEAUT32.dll")
	procVarI8FromDec = oleaut32.NewProc("VarI8FromDec")
)

// pdecIn (DECIMAL*), pi64Out (LONGLONG* out)
r1, _, err := procVarI8FromDec.Call(
	uintptr(pdecIn),
	uintptr(pi64Out),
)
_ = err  // syscall.Errno (valid when the call sets last-error)
_ = r1   // HRESULT

function VarI8FromDec(
  pdecIn: Pointer;   // DECIMAL*
  pi64Out: Pointer   // LONGLONG* out
): Integer; stdcall;
  external 'OLEAUT32.dll' name 'VarI8FromDec';

result := DllCall("OLEAUT32\VarI8FromDec"
    , "Ptr", pdecIn   ; DECIMAL*
    , "Ptr", pi64Out   ; LONGLONG* out
    , "Int")   ; return: HRESULT

●VarI8FromDec(pdecIn, pi64Out) = DLL("OLEAUT32.dll", "int VarI8FromDec(void*, void*)")
# 呼び出し: VarI8FromDec(pdecIn, pi64Out)
# pdecIn : DECIMAL* -> "void*"
# pi64Out : LONGLONG* out -> "void*"
# 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)。

const std = @import("std");

extern "oleaut32" fn VarI8FromDec(
    pdecIn: [*c]DECIMAL, // DECIMAL*
    pi64Out: [*c]i64 // LONGLONG* out
) callconv(std.os.windows.WINAPI) i32;

proc VarI8FromDec(
    pdecIn: ptr DECIMAL,  # DECIMAL*
    pi64Out: ptr int64  # LONGLONG* out
): int32 {.importc: "VarI8FromDec", stdcall, dynlib: "OLEAUT32.dll".}

pragma(lib, "oleaut32");
extern(Windows)
int VarI8FromDec(
    DECIMAL* pdecIn,   // DECIMAL*
    long* pi64Out   // LONGLONG* out
);

ccall((:VarI8FromDec, "OLEAUT32.dll"), stdcall, Int32,
      (Ptr{DECIMAL}, Ptr{Int64}),
      pdecIn, pi64Out)
# pdecIn : DECIMAL* -> Ptr{DECIMAL}
# pi64Out : LONGLONG* out -> Ptr{Int64}
# stdcall は 32bit のみ意味を持つ(x64 では無視)。

local ffi = require("ffi")
ffi.cdef[[
int32_t VarI8FromDec(
    void* pdecIn,
    int64_t* pi64Out);
]]
local oleaut32 = ffi.load("oleaut32")
-- oleaut32.VarI8FromDec(pdecIn, pi64Out)
-- pdecIn : DECIMAL*
-- pi64Out : LONGLONG* out
-- 構造体/GUIDへのポインタは cdef が通るよう void* で表記(実型は各引数コメント参照)。値渡し構造体・enum は対応する typedef を cdef に追加すること。

const koffi = require('koffi');
const lib = koffi.load('OLEAUT32.dll');
const VarI8FromDec = lib.func('__stdcall', 'VarI8FromDec', 'int32_t', ['void *', 'int64_t *']);
// VarI8FromDec(pdecIn, pi64Out)
// pdecIn : DECIMAL* -> 'void *'
// pi64Out : LONGLONG* out -> 'int64_t *'
// 出力ポインタは koffi.out(...) で包む。構造体は koffi.struct で定義。

const lib = Deno.dlopen("OLEAUT32.dll", {
  VarI8FromDec: { parameters: ["pointer", "pointer"], result: "i32" },
});
// lib.symbols.VarI8FromDec(pdecIn, pi64Out)
// pdecIn : DECIMAL* -> "pointer"
// pi64Out : LONGLONG* out -> "pointer"
// 文字列引数は "buffer"(NUL 終端のバイト列を Uint8Array で渡す)。
// 値渡し構造体は { struct: [ ...field types... ] } を使用。

<?php
$ffi = FFI::cdef(<<<C
int32_t VarI8FromDec(
    void* pdecIn,
    int64_t* pi64Out);
C, "OLEAUT32.dll");
// $ffi->VarI8FromDec(pdecIn, pi64Out);
// pdecIn : DECIMAL*
// pi64Out : LONGLONG* out
// 構造体/GUIDへのポインタは cdef が通るよう void* で表記(実型は各引数コメント参照)。値渡し構造体・enum は対応する typedef を cdef に追加すること。
// WINAPI(stdcall): x64 では呼出規約が統一されるため問題なし。x86 では __stdcall 対応のラッパが必要な場合あり。

import com.sun.jna.*;
import com.sun.jna.ptr.*;
import com.sun.jna.win32.StdCallLibrary;
import com.sun.jna.win32.W32APIOptions;

public interface Oleaut32 extends StdCallLibrary {
    Oleaut32 INSTANCE = Native.load("oleaut32", Oleaut32.class);
    int VarI8FromDec(
        Pointer pdecIn,   // DECIMAL*
        LongByReference pi64Out   // LONGLONG* out
    );
}

@[Link("oleaut32")]
lib LibOLEAUT32
  fun VarI8FromDec = VarI8FromDec(
    pdecIn : DECIMAL*,   # DECIMAL*
    pi64Out : Int64*   # LONGLONG* out
  ) : Int32
end
# 構造体/GUID/enum は lib 内に対応する型定義が必要。
# 呼出規約: x64 は規約統一のため OK。x86(32bit)は WINAPI=stdcall だが Crystal の fun に stdcall 付与構文がなく非対応。

import 'dart:ffi';
import 'package:ffi/ffi.dart';

typedef VarI8FromDecNative = Int32 Function(Pointer<Void>, Pointer<Int64>);
typedef VarI8FromDecDart = int Function(Pointer<Void>, Pointer<Int64>);
final VarI8FromDec = DynamicLibrary.open('OLEAUT32.dll')
    .lookupFunction<VarI8FromDecNative, VarI8FromDecDart>('VarI8FromDec');
// pdecIn : DECIMAL* -> Pointer<Void>
// pi64Out : LONGLONG* out -> Pointer<Int64>
// 文字列は package:ffi の "...".toNativeUtf16()/toNativeUtf8() で変換。

{$mode objfpc}{$H+}
function VarI8FromDec(
  pdecIn: Pointer;   // DECIMAL*
  pi64Out: Pointer   // LONGLONG* out
): Integer; stdcall;
  external 'OLEAUT32.dll' name 'VarI8FromDec';

import Foreign
import Foreign.C.Types
import Foreign.C.String

foreign import stdcall safe "VarI8FromDec"
  c_VarI8FromDec :: Ptr () -> Ptr Int64 -> IO Int32
-- pdecIn : DECIMAL* -> Ptr ()
-- pi64Out : LONGLONG* out -> Ptr Int64
-- 要 GHC(Windows)。stdcall は x64 では ccall として扱われる。ブロックする API は safe 呼び出し推奨。

open Ctypes
open Foreign

let vari8fromdec =
  foreign "VarI8FromDec"
    ((ptr void) @-> (ptr int64_t) @-> returning int32_t)
(* pdecIn : DECIMAL* -> (ptr void) *)
(* pi64Out : LONGLONG* out -> (ptr int64_t) *)
(* foreign は cdecl 前提。x64 Windows では WINAPI と一致。構造体は ctypes structure を定義のこと。 *)

(cffi:define-foreign-library oleaut32 (t "OLEAUT32.dll"))
(cffi:use-foreign-library oleaut32)

(cffi:defcfun ("VarI8FromDec" var-i8-from-dec :convention :stdcall) :int32
  (pdec-in :pointer)   ; DECIMAL*
  (pi64-out :pointer))   ; LONGLONG* out
; isize/usize(INT_PTR/SIZE_T)は x64 前提で :int64/:uint64。x86 では :int32/:uint32。

use Win32::API;
my $VarI8FromDec = Win32::API::More->new('OLEAUT32',
    'int VarI8FromDec(LPVOID pdecIn, LPVOID pi64Out)');
# my $ret = $VarI8FromDec->Call($pdecIn, $pi64Out);
# pdecIn : DECIMAL* -> LPVOID
# pi64Out : LONGLONG* out -> LPVOID
# 値渡し構造体は pack() した文字列、または Win32::API::Struct を使用。