Re: [Libexif-devel] Error handling

[Joerg H. <jo...@de...>]

On Tue, May 18, 2004 at 07:20:07AM +0200, Lutz Müller wrote:

> 
> > Why do I have to return a struct when no error occurred?
> 
> I thought about something like that:
> 
> int
> main (...) {
>     int i1, i2;
>     ExifError e = {0, ""};
> 
>     /* Calling a function without error checking */
>     exif_function (i1, i2, NULL);
> 
>     /* Calling a function with error checking */
>     exif_function (i1, i2, &e);
>     if (e.id != 0) 
>         printf ("Error %i occurred: %s.\n", e.id, e.msg);
> }

That would be much work to do; I think at this moment it would be easier to
work with return values. The errors I want to catch with this approach are
relativly "simple" errors like error return values of libc-calls (malloc,
realloc) and possibly invalid (NULL) arguments. Look at the points in
functions where at this moment we just do a simple "return". Most times
it's enough to distinct between "error occured" and "no error".

There we don't need a highly-sophisticated concept how we want to do our
error handling. We just need to detect them. On higher levels a solution
like your proposal would be ok, but on the bottom level it's kind of overkill.

Joerg

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