定义子过程的伪指令: PROC、ENDP ; Test9_1.asm .386 .model flat, stdcall include Windows.inc include kernel32.inc include masm32.inc include debug.inc includelib kernel32.lib includelib masm32.lib includelib debug.lib .code ;子过程 proc1: proc1 proc PrintText ''proc1'' proc1 endp ;子过程 proc2: proc2 proc PrintText ''proc2'' proc2 endp ;子过程 proc3: proc3 proc PrintText ''proc3'' proc3 endp ret end proc1 ;end 后面的 proc1 是入口的子过程名; 这也就是指定主过程. ;可以把 end proc1 分别换做 end proc2 和 end proc3 尝试, ;如果这是一个供其他程序调用的代码文件, 那么 end 后面就不需要指定.
模仿 C 语言的样子, 以后的程序结构应该这样: ; Test9_2.asm .386 .model flat, stdcall include Windows.inc include kernel32.inc include masm32.inc include debug.inc includelib kernel32.lib includelib masm32.lib includelib debug.lib .data szText db ''Hello World!'', 0DH, 0AH, 0 .code main proc PrintString szText ;Hello World! ret main endp end main
局部变量要用 local 声明, 和全局变量区别不小: ; Test9_3.asm .386 .model flat, stdcall include windows.inc include kernel32.inc include masm32.inc include debug.inc includelib kernel32.lib includelib masm32.lib includelib debug.lib .code main proc ;局部变量中的类型不能使用缩写 LOCAL v1: dword ;可用逗号间隔写在一行 LOCAL v2: dword, v3: dword ;不指定类型时默认 DWORD(在 Win32 下) LOCAL v4 ;数组 LOCAL v5[3]: dword ;在手动初始化前, 局部变量中都是些垃圾值: PrintDec v1 PrintDec v2 PrintDec v3 PrintDec v4 mov eax, v5[0] PrintDec eax ret main endp end main
调用子过程: ; Test9_4.asm .386 .model flat, stdcall include windows.inc include kernel32.inc include masm32.inc include debug.inc includelib kernel32.lib includelib masm32.lib includelib debug.lib .code ; proc1 proc PrintDec 1 ret proc1 endp ; proc2 proc PrintDec 2 ret proc2 endp ; main proc PrintDec 0 call proc2 call proc1 ret main endp end main ;注释: ;最后一行 end main 决定了子过程将被率先调用, 这样它就成了主过程 ;然后主过程又通过 call 指令顺序调用了 proc2、proc1 ;这样最后的显示结果将是: 0 / 2 / 1 ;子过程应该用 ret 指令返回
一个求和函数的例子: ; Test9_5.asm .386 .model flat, stdcall include windows.inc include kernel32.inc include masm32.inc include debug.inc includelib kernel32.lib includelib masm32.lib includelib debug.lib .code ;求和的函数, 函数返回值在 eax sum proc v1: dword, v2: dword mov eax, v1 add eax, v2 ret sum endp ; main proc invoke sum, 11, 22 PrintDec eax ;33 ret main endp end main (责任编辑:admin)
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