;功能:查找32位之间的赋值语句是否有语法错误,如果没有就输出,如果有就输出错误;
;为了减少情况判断;特意规定mov后面的第一个参数必须为寄存器。
;赋值语句中32位赋值和16位、8位等情况的赋值语法完全相同,
;所以这里只判断32位赋值的情况,并且假设这里的内存操作数一定是写对的
;用str1来存储要判断的语句,用str2来存储内存操作数的类型。
include irvine32.inc
.data
i dword 1;

c1 byte "改语法不正确:",0;
c2 byte "相等",0;
c3 byte "该语法正确",0;
c4 byte "寄存器的名字写错了:",0;
c5 byte "内存操作数错了:",0;
c6 byte "mov写错:",0;
c7 byte "“,”写错了:",0;

str1 byte "mvo edx,offset sdr",0
str2 byte "sdr qword ?",0;
str3 byte 20 dup(?),0;

k1 byte "mov",0;
k2 byte "eax,ebx,ecx,edx,ebp,esp,esi,edi";
k3 byte "offset ",0;
k4 byte "dword ptr ",0;
.code
main proc


;判断“,”是否正确;
mov edi,offset str3;
mov esi,offset str1;
add esi,7;
movsb;

mov al,byte ptr str3;
cmp  al,',';
jne quit1                    ;不是‘,’则报错;

;判断mov;
cld;                        先取前三个字符;
mov edi,offset str3;
mov esi,offset str1;
mov ecx,3;
rep movsb;

cld;                        判断前三个字符是否为"mov"
mov esi,offset k1;
mov edi,offset str3;
mov ecx,3;
repe cmpsb;

je  L1;
jmp quit2                  ;不是mov报错


L1:
;判断第一个参数是否寄存器;
                           ;取中间3个字符
 mov edi,offset str3;
 mov esi,offset str1;
 add esi,4;
 mov ecx,3;
 rep movsb;

 mov edx,offset str3;
 mov esi,offset k2;

 L2:                       ;循环判断是否是寄存器
         cld;
         cmp i,9;
         je L3;            ;判断完了还不是寄存器,跳出循环;

     push esi;
     mov edi,offset str3;
     mov ecx,3;
     repe cmpsb;
     je L3;              判断出是寄存器了,跳出循环
     pop esi;
     inc i;
     add esi,4;
     jmp L2;

 L3:

        cmp i,9;            判断跳出循环的原因是什么,是找到了还是没找到;
        je  quit3;           没找到报错

        mov eax,lengthof str1
        sub eax,9;
        cmp eax,3;
        jne n1;             判断第二个数如果不是3个字符,则应该为内存操作数;
                            ;16、8的寄存器的情况不予考虑。

        ;判断第2个数是不是寄存器
        mov i,1;
        mov edi,offset str3;
        mov esi,offset str1;
        add esi,8;
        mov ecx,3;
        rep movsb;

        mov esi,offset k2;
        L4:
                cld;
                cmp i,9;
                je L5;
            push esi;
            mov edi,offset str3;
            mov ecx,3;
            repe cmpsb;
            je L5;
            pop esi;
            inc i;
            add esi,4;
            jmp L4;
            L5:
            cmp i,9;
                je  n1
         ;第二变量的变量名长度为三个字节可能是32位寄存器也可能是内存操作数
         mov edx,offset c3;
         call writestring;
         call crlf;
         jmp next;

  ;判断是否是取地址;
n1:
  mov edi,offset str3;
  mov esi,offset str1;
  add esi,8;
  mov ecx,7;
  rep movsb;

  cld;                        判断
  mov esi,offset k3;
  mov edi,offset str3;
  mov ecx,7;
  repe cmpsb;
  jne  n2;
          mov eax,lengthof str1;     判断后面有没有内存操作数
      cmp eax,16;
          je quit4;
          mov edx,offset c3;
           call writestring;
           call crlf;
         jmp next;

   ;判断是否是类型转换成32位的可是必须是高的才能转成低的;
 n2:
     mov edi,offset str3;
     mov esi,offset str1;
     add esi,8;
     mov ecx,10;
     rep movsb;
     ;mov edx,offset str3;
     ;call writestring;
     ;call crlf;
     cld;                        判断
     mov esi,offset k4;
     mov edi,offset str3;
     mov ecx,10;
     repe cmpsb;
     jne  n3;
             mov eax,lengthof str1;     判断后面有没有内存操作数
         cmp eax,19;
             je quit4;

             mov eax,lengthof str1;     判断后面的内存操作数是不是不低于32位的;
         sub eax,18;
         ;call writeint;
         ;call crlf;
         mov esi,offset str2;
         add esi,eax;
         mov al, byte ptr [esi];
             cmp al,'d';
             je b1;
             cmp al,'q';
             jne quit4;

          b1:
             mov edx,offset c3;
              call writestring;
              call crlf;
         jmp next;
 n3:
  ;判断如果有常量的字节数是否为32位;
    mov ebx,lengthof str1;
    sub ebx,8;
    mov edi,offset str1;
    add edi,8;
    mov al,' ';
    mov ecx,ebx
    repne scasb;           扫描是否变量名中含有空格,有的话,报错;
    jz  quit4;

  mov ebx,lengthof str2;

  mov eax,lengthof str1
  sub eax,8;

  cmp ebx,eax;
  jna  quit4;              变量名的长度比定义的还长,报错;

  mov edi,offset str3;
  mov esi,offset str2;
  add esi,eax;
  movsb;
  mov al, byte ptr str3;
  cmp al,'d';
  jne  quit4;
          mov edx,offset c3;
          call writestring;
          call crlf;
          jmp next;
quit1:;","不对时,输出提示语;
    mov edx,offset c7;
    call writestring;
    call crlf;
    jmp next;
quit2:;"mov"不对时,输出提示语;
    mov edx,offset c6;
    call writestring;
    call crlf;
    jmp next;
quit3:;寄存器不对时,输出提示语;
    mov edx,offset c4;
    call writestring;
        call crlf;
        jmp next;
quit4:;内存操作数不对时,输出提示语;
    mov edx,offset c5;
    call writestring;
        call crlf;

next:
exit
main endp
end main

posted on 2013-02-25 19:08  叶城宇  阅读(156)  评论(0编辑  收藏  举报