Technically an API break

Matt Caswell matt at
Thu May 7 15:41:39 UTC 2020

On 07/05/2020 16:02, Brian Smith wrote:
> This kind of change might cause memory unsafety issues unless the
> application is recompiled. At least, it's worth investigating that.
> On most platforms the ABI of a function that returns `void` and one that
> returns `int` is the same, from the perspective of a caller that doesn't
> expect or use the return value. I seem to vaguely remember in the past
> that there was at least one common platform where that isn't true
> though. Unfortunately I cannot remember which one it is. I also don't
> remember if it is problematic to change from "int" to "void" or "void"
> to "int" or both.
> Anyway, my point is that you should consider this an ABI-breaking
> change, not just an API breaking one.

Yes - thanks for that Brian. Actually though this change is targeted
only at the master branch (which will become OpenSSL 3.0). That is a
major release and is already ABI breaking - so recompilation is already
a requirement. Actually as a major release we are allowed to be API
breaking too, but we are trying to keep that to a minimum.


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