MASM(x64)のサンプル

環境

• Windows 11 Pro
• Visual Studio Community 2022

hello, world

devasm.bat

@echo off
set vcdir=C:\Program Files\Microsoft Visual Studio\2022\Community\VC\Tools\MSVC\14.41.34120
path %path%;%vcdir%\bin\Hostx64\x64
set lib=%lib%;C:\Program Files (x86)\Windows Kits\10\Lib\10.0.22621.0\um\x64
prompt $e[33m$p$g$e[m
cmd

fig1.asm

; ml64 /c /Fl fig1.asm
; link /entry:start /subsystem:console fig1.obj

includelib kernel32

STD_OUTPUT_HANDLE equ -11

extern	ExitProcess :proc
extern	GetStdHandle :proc
extern	WriteConsoleA :proc

.const
msg	db	'hello, world',0dh,0ah
len	equ	$ - msg

.code
public start
start:
	sub	rsp, 56
	mov	ecx, STD_OUTPUT_HANDLE
	call	GetStdHandle

	mov	qword ptr [rsp+32], 0
	xor	r9d, r9d
	mov	r8d, len
	lea	rdx, offset msg
	mov	rcx, rax
	call	WriteConsoleA

	xor	ecx, ecx
	call	ExitProcess
end

Cコンパイラで/FAオプションを付けてアセンブリリスト（.cod）を出力すると参考になる。

fig2.c

// cl /MD /FAsc /O2 fig2.c
const char msg[7] = "hello\r\n";

int main(void)
{
	void *h = GetStdHandle(-11);
	WriteConsoleA(h, msg, 7, 0, 0);
	ExitProcess(0);
}

MASMからCライブラリ関数を呼ぶ

fig3.asm

; ml64 /c /Fl fig3.asm
; cl /MD fig3.obj

includelib msvcrt
includelib legacy_stdio_definitions

extern	printf :proc

.const
msg	db	'hello, %d',0ah,0

.code
main proc
	sub	rsp, 40

	mov	edx, 42
	lea	rcx, offset msg
	call	printf

	xor	eax, eax
	add	rsp, 40
	ret
main endp
end

Cからアセンブリ関数を呼ぶ

fig4.c

// cl /MD fig4.c fig4a.obj

#include <stdio.h>

int hoge(int);

int main(void)
{
	printf("%d\n", hoge(42));
}

fig4a.asm

; ml64 /c fig4a.asm

.code
hoge proc
	mov	eax, ecx
	add	eax, eax
	ret
hoge endp
end