Build failure: -Wno-unused-const-variable DNE on old GCC

[Maciej W. Rozycki]

On Thu, 7 Jan 2016, Brian Norris wrote:

> > Perhaps most uses of -Werror without some CONFIG_<FOO> guard
> > should be removed or replaced by some other mechanism.
> 
> +1000. I'd personally like to see all one-off uses of -Werror removed.
> 
> > $ git grep -E "=\s*\-Werror" | grep -v CONFIG
> > [...]
> > arch/alpha/lib/Makefile:ccflags-y := -Werror
> > arch/alpha/mm/Makefile:ccflags-y := -Werror
> > arch/alpha/oprofile/Makefile:ccflags-y := -Werror -Wno-sign-compare
> > arch/metag/oprofile/Makefile:ccflags-y	+= -Werror
> > arch/mips/Kbuild:subdir-ccflags-y := -Werror
> 
> ^^ I always patch this one out when build-testing MIPS, since I like to
> turn up warning levels (e.g., W=1), but not kill the build entirely.

 The MIPS port switched on -Werror years ago, because people submitted 
awful code and couldn't be bothered unless the build crashed.  You're 
welcome to patch your own tree, however I maintain it was a very good 
decision, and TBH I think -Werror should be on globally.

  Maciej