On Fri, Apr 05, 2019 at 06:05:50PM +0200, Luis Ressel wrote: > 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. Maybe so, but objtool only supports two compilers: GCC and clang. And only one version of libelf ;-) > 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.) I consider that a good thing, because I *want* the build to be broken when somebody uses a bad version of libelf. A patch to produce a more useful error message (e.g., "bad version of libelf") would be welcome of course. If/when we get to the point where there's a valid use case for warnings in the objtool build, I would consider this patch. But we don't seem to be there yet. -- Josh
