Warning: Configuration logfiles contain indications of -Wimplicit-function-declaration; check that features were not accidentally disabled:

[Michael Newman]

When upgrading MacPorts this morning I noticed the following message wizzing by:

Warning: Configuration logfiles contain indications of -Wimplicit-function-declaration; check that features were not accidentally disabled:

This right after:

--->  Configuring xorg-libxcb

I've never seen "Wimplicit" used before and wondered what it meant. When I searched I got:

Your search - -Wimplicit - did not match any documents.

Can someone please explain what this warning is about and just what "Wimplicit" means?

Mike Newman
Korat, Thailand