Re: Link time optimization 'bug' report.

[Gé Weijers <ge@...>]

On Fri, Jun 12, 2020 at 11:20 Roberto Ierusalimschy <roberto@inf.puc-rio.br> wrote:

 

The compiler only detects this instance, but Lua has had lots of
instances like that for a long time. The problem is that we have a
tagged union, and some tags don't need the union, and therefore don't
use it. In 5.4 that includes booleans, but nil is like that since
the beginning.  Whenever we copy a nil TValue, we are accessing an
uninitialized value_ field.

I figured as much, but I did not want to assume my analysis was correct. I quoted 'bug' intentionally.

Thanks for the explanation.

Gé