Quite a few of the warnings not enabled in -Wall or -Wextra fail spuriously on good code. In combination with -Werror, new failures on perfectly fine code is frustrating for developers.
I'd rather have a couple of false positives and then selectively disable warnings (I think one can use pragmas to disable specific warnings for specific regions of code in gcc).
At least, I would like an additional flag that really does enable all warnings, say -Wabsolutelyall or something like that.
You probably don't want that, but a flag that enables all sensible messages, yet does not enable stuff that is there just for compatibility or because it's useful in some context.
It should also disable Werror, otherwise we will be claiming for some new flags in a few years.
