Re: Removing -Wunsuffixed-float-constants, -Wdouble-promotion, -Wformat-zero-length

[Simon Josefsson]

Jim Meyering <address@hidden> writes:

> Instead, how about automating the extraction of the list of
> warnings from gcc sources or from some web page?  Maybe you've
> already done something like that?
> Then we could add a rule to gnulib's Makefile that would ensure
> our list is up to date and run it periodically (albeit manually).

This is unfortunately a big mess and I do it manually.  As a result of
doing it manually, I'm pretty sure some warnings are missing and some
are repeated (due to being implied by other flags).  The problems
include:

1) The gcc manual doesn't list all warning flags.

2) The gcc --help=warnings doesn't list all warning flags, although it
   is a different subset than 1).

3) Several of the warnings mentioned by gcc --help=warnings does not
   apply to C.

4) Some warning flags imply other flags, which complicate things.
   Should the redundant flag be removed or not?  It is made even more
   complicated since this may change between gcc versions.

I think there were other problems as well.  As a result, I gave up
trying to automate it and did it manually initially just to get some
warnings enabled.

It would be nice to automate this.  I'm not sure whether to use the
manual or the source code as the canonical source, although I lean
towards using the source code.  I'm not sure how easy it would be to get
a list though, I recall that warnings were not handled uniformly within
gcc sources.

/Simon