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

[Basile Starynkevitch]

On 1/27/24 20:27, Basile Starynkevitch wrote:
> 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

[...]

The issue is of course to find the relation between ebuf (which is a 
local parameter in GNU make source read.c) and the functions in 
function.c....

My guess is that since GNU make is itself a serial (non-threaded) 
program, that relation should be simple to find.

Should I have to find it, I would use gdb breakpoint facilities.

Thanks for reading.

Regards.

NB I might perhaps implement such a feature if (and only if) I don't 
have any copyright assigment to find. In my GCC contributing experience 
fifteen years ago, that administrative step was really painful. I am too 
old to start such nightmares again.

--
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