Re: feature requests: $(__FILE__) and $(__LINE__) textual macros

[Basile Starynkevitch]

On 1/27/24 20:11, Paul Smith wrote:
> On Sat, 2024-01-27 at 18:06 +0100, Basile Starynkevitch wrote:
> > For non-trivial GNUmakefile-s on Linux it would be nice to have a
> > $(__FILE__) and $(__LINE__) textual macros of GNU make.
>
> It would be great if you could provide examples where these would be
> useful, especially examples that are not already covered by the output
> of the -p option to GNU Make.

make -p don't show (unfortunately) the line number in makefiles. 
Alternatively, a runtime option for make -p (perhaps 
--show-line-numbers) would be nice.
> I'm not saying we shouldn't introduce these, although I think you
> misunderstand how tricky it would be to use them (for example, if you
> set:
>
>      FOO = $(__LINE__)

This would be expanded at Makefile parsing time. Not at function 
invocation time.

If I started to implement it, I would add

  FT_ENTRY ("__LINE__",           0,  0,  0,  func__LINE__),

in GNU make's  src/function.c file.


and probably func__LINE__ would return some ebuf->floc.lineno


For
  FT_ENTRY ("__FILE__",           0,  0,  0,  func__FILE__),

I guess func__FILE__ would return some ebuf->floc.filenm

So my intuition is that this feature is easy to implement.

Sorry, English is not my native language, but I was thinking of 
$(__FILE__) and $(__LINE__) being implemented as close as possible to 
the GNU make parsing code.

Thanks for your email.

Regards
--
Basile Starynkevitch             <basile@starynkevitch.net>
(only mine opinions / les opinions sont miennes uniquement)
92340 Bourg-la-Reine, France
web page: starynkevitch.net/Basile/
See https://github.com/RefPerSys/RefPerSys