foo.cc: In function 'int cal(int, int)':
foo.cc:5:5: error: expected '(' before '{' token
     {
     ^
foo.cc:6:9: error: 'mov' was not declared in this scope
         mov eax,a;
         ^~~
foo.cc:7:13: error: expected ';' before 'ebx'
         mov ebx,b;
             ^~~
foo.cc:8:9: error: 'add' was not declared in this scope
         add eax,ebx;
         ^~~
foo.cc:10:1: warning: no return statement in function returning non-void [-Wreturn-type]
 }
 ^
foo.cc: In function 'int main()':
foo.cc:14:10: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
     scanf("%d%d",&a,&b);
     ~~~~~^~~~~~~~~~~~~~

自豪的采用HydroJudge(https://github.com/hydro-dev/Hydro)进行评测。