Re: should make elide the difference between "dir" and "dir/"?

[David Boyce]

Thanks but just to be clear(er), I'm not looking for help solving a problem
of my own, just suggesting that it might make sense for GNU make to ignore
a trailing "/" when comparing directory names just as it already ignores a
leading "./".

Thanks for the pointer to the library, though. Looks like lots of good
stuff.

David

On Fri, Oct 8, 2021 at 1:43 AM Mark Piffer <mark.piffer@gmail.com> wrote:

> The GNUmake table toolkit has an extension to the wildcard function, maybe
> this could help you:
> https://github.com/markpiffer/gmtt#call-wildcard-reclist-of-globs
>
>
> Am So., 3. Okt. 2021 um 22:51 Uhr schrieb David Boyce <
> david.s.boyce@gmail.com>:
>
>> It's documented that make implements a special case to treat pathnames
>> "foobar" and "./foobar" as identical even though comparisons are usually
>> lexical, but I notice that it doesn't do the same with trailing slashes on
>> directory names. For instance in the test case below the target depends on
>> its parent directory $(@D) which comes out as "foo". We've supplied a rule
>> for making it but due to the behavior of the $(dir ...) function that
>> comes
>> out as "foo/" which doesn't match. This can be "fixed" with the patsubst
>> function but life would be more convenient and less mysterious if make
>> recognized them as the same. Has this been considered in the past?
>>
>> The obvious concern is that we don't know a priori whether a target is a
>> directory or file. However, since "foo/" is illegal for anything but a
>> directory it seems harmless to assume directory. This matching could also
>> be made to apply exclusively to order-only prerequisites which is where
>> directories should be anyway.
>>
>> David
>>
>> $ cat Makefile
>> .SECONDEXPANSION:
>>
>> target := foo/bar
>>
>> $(target): $$(@D)
>> touch $@
>>
>> $(dir $(target)):
>> mkdir -p $@
>>
>> $ make
>> make: *** No rule to make target 'foo', needed by 'foo/bar'.  Stop.
>>
>