Warnings

[Simon Marlow]

Ian Lynagh wrote:

> I'd go for plain old -Wall, personally.
> 
> How much is this style of name shadowing used in GHC? Do people think it
> is desirable?

Personally I like to use shadowing and I think -fwarn-name-shadowing is 
overkill, but there are cases where it can catch real bugs.  Take this as a 
vote against rather than a veto; I'll go with the majority.

I really like the idea of having -Werror for validate.  It'll only apply to 
the modules for which we've turned on warnings, and the number of those 
will grow over time.  We might want this only for stage2, otherwise we're 
at the mercy of buggy warnings in earlier compilers, though.

Cheers,
	Simon