On 11/17/2017 12:12 PM, Wilco Dijkstra wrote: > GCC currently defaults to -fcommon. This is an optional C feature dating > back to early C implementations. On many targets this means global variable > accesses having an unnecessary codesize and performance penalty in C code > (the same source generates better code when built as C++). Given there isn't > a lot of software that really requires this (mostly it's accidentally > forgetting to > use 'extern' in a header), it is about time to change the default. > > What do people think? I presume someone with access to distro source code > and a fast build machine could try and see how many packages fail to get an > idea how feasible it is. We could keep defaulting to -fcommon with -std=c89 > if necessary. > > 2017-11-17 Wilco Dijkstra <wdijk...@arm.com> > > * common.opt (fcommon): Change init to 1. > * doc/invoke.texi (-fcommon): Update documentation. I'd tentatively support this -- meaning I'd be willing to ack it as long as we all agree that if it causes significant problems during the mass rebuilds done by the distros (typically during Dec-Feb) that we'd revert.
It'd need a release note as well. Jeff
