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//asm source code note 1.4_do_while循环的实现

29: 30:   int FnDo(int a, int b) 31:   { //保存基址和栈顶 004010F0   push        ebp 004010F1   mov         ebp,esp //开辟内部变量空间, 变量有2个 004010F3   sub         esp,48h 004010F6   push        ebx 004010F7   push        esi 004010F8   push        edi 004010F9   lea         edi,[ebp-48h] 004010FC   mov         ecx,12h 00401101   mov         eax,0CCCCCCCCh 00401106   rep stos    dword ptr [edi] //[ebp - 8] = 内部变量2 (var2) //[ebp - 4] = 内部变量1 (var1) //[ebp + 0] = 函数入口ebp //[ebp + 4] = 函数返回地址 //[ebp + 8] = 函数形参1 (para1) //[ebp + 0xc] = 函数形参2 (para2) 32:       int c = a + b; //var1 = para1 + para2; 00401108   mov         eax,dword ptr [ebp+8] 0040110B   add         eax,dword ptr [ebp+0Ch] 0040110E   mov         dword ptr [ebp-4],eax 33:       int i = 0; //var2 = 0; 00401111   mov         dword ptr [ebp-8],0 34: 35:       do 36:       { 37:           c = c + i; //var1 = var1 + var2; loop1: 00401118   mov         ecx,dword ptr [ebp-4] 0040111B   add         ecx,dword ptr [ebp-8] 0040111E   mov         dword ptr [ebp-4],ecx 38:       } while (++i < 50); //var2 += 1; 00401121   mov         edx,dword ptr [ebp-8] 00401124   add         edx,1 00401127   mov         dword ptr [ebp-8],edx //if(var2 < 0x32) //    goto loop1; 0040112A   cmp         dword ptr [ebp-8],32h 0040112E   jl          FnDo+28h (00401118) 39: 40:       return c; //return var1; 00401130   mov         eax,dword ptr [ebp-4] 41:   } //恢复堆栈，返回 00401133   pop         edi 00401134   pop         esi 00401135   pop         ebx 00401136   mov         esp,ebp 00401138   pop         ebp 00401139   ret //把伪代码整理一下,如下: Function(para1, para2) {     var1;     var2;     [var1] = [para1] + [para2];     [var2] = 0; loop1:     [var1] = [var1] + [var2];     [var2] += 1;     if([var2] < 0x32)     {         goto loop1;     }     return [var1]; } //把伪代码整理成c语言源码 DWORD Function(DWORD dwPara1, DWORD dwPara2) {     DWORD dwVar1 = dwPara1 + dwPara2;     DWORD dwVar2 = 0;     do     {         dwVar1 = dwVar1 + dwVar2;     }while(++dwVar2 < 0x32);     return dwVar1; } //原版的代码 int FnDo(int a, int b) {     int c = a + b;     int i = 0;         do     {         c = c + i;     } while (++i < 50);     return c; } //经过asm to c, 逆向后的源码与原版源码的区别如下: //实现的功能一样 //函数形参和变量的类型看不出来了，都变成了DWORD //形参和变量的含义看不出来了，需要根据上下文进行进一步整理

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