Re: ABI Compatibility (was Re: Installation woes for the average user...)

[Richard Frith-Macdonald]

On 20 May 2009, at 12:29, David Chisnall wrote:

> In fact, this link appears to directly contradict itself:
>
> > The library (SONAME) versions is changed when the major or minor  
> > version number of a release changes, but not the subminor number.
>
>
> and
>
> > The minor version number is changed (and therefore the library  
> > version) when we break backward compatibility

In what way does that contradict itsself?

major number changed implies soname changed
minor number changed implies soname changed
subminor number changed does not imply soname changed

backward compatibility broken, implies minor number changed, which  
implies soname changed

> This does not appear to be what really happens.

I guess appearances can be deceptive.

> The minor version number is changed with each new release.

Not so. For example, we have base 1.19.0 and 1.19.1 and we have base  
1.16.0 and 1.16.1 and 1.16.3 and 1.16.4 and 1.16.5

I suppose there is a tendency to only notice when new releases have  
new soname versions, and not notice when they don't.