On Fri, Apr 05, 2019 at 04:16:14PM +0000, David Laight wrote: > From: Luis Ressel > > Sent: 05 April 2019 17:06 > > On Fri, Apr 05, 2019 at 09:39:26AM -0500, Josh Poimboeuf wrote: > > > > > Hm, I would actually argue the reverse. Warnings are generally bad and > > > -Werror is useful for ensuring that we don't have any. For warnings > > > that don't provide value, we just disable those individual warnings. > > > > Sure, during development it's an excellent idea to investigate compiler > > warnings, and -Werror can be useful for that. But the Linux kernel is > > built by countless users in wildly varying environments, and it's almost > > a given that someone will use a compiler that'll complain about a valid > > part of your code whose style it considers bad. > > > > As an example, the warning that's breaking the build for me is -Wundef > > complaining about several "#if UNDEFINED_IDENTIFIER" constructs in the > > libelf headers. (I agree with gcc in considering this bad style, but > > it's perfectly valid C, and there probably wasn't a warning about it > > back when this header was written.) > > In which case you should be looking at a way of removing -Wundef > not removing -Werror. Agreed. > FWIW I had to update libelf.so from version 0.153 to 0.165 in > order for the amd64 orc unwinder code in objtool to not generate > corrupt output files. > That is an Ubuntu 13.04 system - nothing like 10 years old. Ah. It would be great if we had a patch to fail the build for old versions of elfutils-libelf as well. -- Josh
