Re: [PATCH] Add new 'AM_PROG_AR' macro, triggering the 'ar-lib' script.

[Peter Rosin]

Den 2010-09-21 12:46 skrev Stefano Lattarini:
> Hi Peter.
> 
> On Tuesday 21 September 2010, Peter Rosin wrote:
>> Den 2010-09-17 11:58 skrev Stefano Lattarini:
>>> Or what about doing somethins similar to what gcc does, and add a
>>> new `-Wextra' category whose warnings are *not* enabled by
>>> `-Wall', but which, when enabled, still causes `automake
>>> -Werror' to fail?  This (assuming your warning will become an
>>> "extra" one) would also have the positive collateral effect of
>>> not forcing you to change *any* existing test.  WDYT?
>>
>> I'm not too thrilled if there would be no sign of a needed
>> AM_PROG_AR when "automake -Wall" is used.
> The fact is, IIUC (and please correct me if I don't), the ar-lib
> wrapper is required only when building on Windows with Microsoft
> developement tools.

Correct.

> Now, many projects might not care at all to support this building 
> environment, while still wanting to use `-Wall' to catch common 
> pitfalls; in this scenario, a warning triggered by `-Wall' about 
> missing AM_PROG_AR would be just an annoyance.  Worse again, the
> use of `-Wall -Werror' would *force* the use of AM_PROG_AR and
> ar-lib, and the developers of aforementioned projects might see
> this forced additions as useless bloat.

Aha, but now you are taking the position that the only way to not
have it invisible is if it doesn't show up with -Wall and that
it doesn't trip up -Wall -Werror.  What is the problem with
inventing a new warning class that prints an informational
messages but that doesn't trigger -Werror?  Then you could have
the -Wextra option that turns the informational messages into
"real" warnings that trigger -Werror (and -Wno-extra would
silence the messages altogether).  Or something.

I.e. four states: silence, info, warning, error.

> On the other hand, if we add a new warning class (say `-Wwin32'
> or `-Wwindows-portability') we'd allow the developers interested
> in porting to Windows to enable the relevant warnings (for now
> only the warning about missing AM_PROG_AR, but new ones can be
> added in the future), without hassling the developers interested
> in supporting only "true" Unix platforms.

I don't like the special casing of Windows at all.  Would you have
suggested it for any other platform?  -Wextra is much better.

>> I'm not sure if anybody will ever add AM_PROG_AR without a
>> poke if it's that invisible.
> Hmmm... you have a point here, but I still hold my position.
> Maybe we should point clearly to the new `-Wwindows-portability'
> warning class in key places of the Automake manual (with proper
> examples)?  Or even add a whole new section about "building on
> Windows"?

I'm not sure in what manual that section should be in though.
I don't think having it spread out in all of autotools is the
most helpful way to do it.

Cheers,
Peter