C error handling coding-style [closed]

问题:

In the case of the following code structure:

int function_sequence(...)
{
    f1(...);
    f2(...);
    f3(...);
    f4(...);
    f5(...);
    return SUCCESS;
}

Which way of the error handling is more acceptable?

This:

int function_sequence(...)
{
    if(f1(...)){
         // Error handling
         return ERROR;
    }

    if(f2(...)){
         // Error handling
         return ERROR;
    }

    ...

    return SUCCESS;
}

Or this:

int function_sequence(...)
{
    if(f1(...)){
        goto error;
    }

    if(f2(...)){
        goto error;
    }

    ...

    return SUCCESS;

error:
    // Error handling
    return ERROR;
}

回答1:

For C, I prefer your second option.

Further, it's useful to do gradual cleanup (free allocated memory and so on), like in Linux kernel:

int function_sequence(...)
{
    if(f1(...)){
        goto error1;
    }

    if(f2(...)){
        goto error2;
    }

    ...

    return SUCCESS;

error2:
    cleanup2();

error1:
    cleanup1();

    // Error handling
    return ERROR;
}

回答2:

int function_sequence(...)
{
    if (f1(...) && f2(...) && f3(...)  && f4(...) && f5(...)) 
        return SUCCESS;
    else
        return ERROR;
}

回答3:

If it's an exceptional thing that makes the function not work, throw an exception.

If you have reason to stick to a return code, you can use

if ( f1() && f2() && .... )
    return SUCCESS;
else
    return ERROR;

Execution will stop after the first false or 0 is encountered, so the effects are pretty much the same as your version.

Some libraries return 0 on success (heh, even C++'s main does so). So you might want

if ( !f1() &&.... )

or a simple

return f1() && f2() &&.... ;

回答4:

This is what i normally use

int function_sequence(...)
{
    if(f1(...)){
        goto error1;
    }

    if(f2(...)){
        goto error2;
    }

    return SUCCESS;
}

error1:
    // Error 1 handling
    return -eerno1;

error2:
    // Error 2 handling
    return -eerno2;

//end of main

回答5:

The way i like to do is the following in c langage :

int function_sequence(...)
{
    int res=0;

    if(f1(...)){
        goto ENDF;
    }

    if(f2(...)){
        goto ENDF;
    }

    ...

    res = 1;

ENDF:
   if(res ==0)
   {
      //Error handling
   } 

   //Success and Error stuff to do (like free...).

    return res;
}

So there is only one return, and sometimes there is some actions to do in both : error and success (such as free...).

I guess my point of view can be discussed.

回答6:

In C, I'd use the third option:

int function_sequence(...)
{
    bool ok = true;
    if (ok) ok = f1(...);
    if (ok) ok = f2(...);
    if (ok) ok = f3(...);
    if (ok) ok = f4(...);
    if (ok) ok = f5(...);

    if (!ok) error_handling();

    cleanup();  // Your example didn't have this, but it's often here.

    return ok ? SUCCESS : ERROR;
}