Building libstdc++-v3 and -WError

[Benjamin Kosnik]

> In the (what now seems ancient) GLIBCPP_ENABLE_DEBUG entry for acinclude.m4,
> I wrote a comment, "Perhaps --enable-maintainer-mode should automatically
> turn this on?".

indeed

Perhaps --enable-maintainer-mode should also turn on -Werror? I like that 
approach too.

> I realize that none of this is in the intention of the maint-mode flag
> either -- and bkoz's message makes me wonder if I fully understand the
> intention of debug_flags now -- but I personally would prefer a single
> setting which signifies, "I am one of the maintainers / I am paranoid
> about this build / I enjoy pain" to turn on all of these switches.
> 

well this only shows with -O2, and --enable-debug explicitly sets -O0 -ggdb

> The reasoning is that if you're enabling maintainence of dependancies,
> and a debug build, and a no-optimization build, you're probably interested
> in the related flags as well, like -W*.  If you're not interested in one
> of the above, you're probably not interested in any of the above.

yeah probably. problem being that optimization setting, warning as error 
setting, debugging format are all in play.... at some point there will 
probably be other things too. (looks like --gc-sections...)


it now seems like removing -Werror is a good idea. 

-benjamin