Re: Autoconf fails test 4 with m4-1.4.7a

[Eric Blake]

Ralf Wildenhues <Ralf.Wildenhues <at> gmx.de> writes:

Hi Ralf, and thanks for the report.

> 
> With current Autoconf HEAD (and 2.60, FWIW), and M4 branch-1_4,
> I get a failure of Autoconf's test 4 on my GNU/Linux system.
> 
>  configure.ac:13:TRACE2:active::ACTIVE
> -configure.ac:19:TRACE1:foo bar:bar foo
> +configure.ac:16:TRACE1:foo bar:bar foo

This was an intentional behavior change in M4 1.4.7a.  From the NEWS file:

* Warnings and errors issued during macro expansion are now consistently
  reported at the line where the macro name was detected, rather than
  where the close parenthesis resides.  Text wrapped by `m4wrap' now
  remembers the location that was in effect when m4wrap was invoked,
  rather than changing to line 0 and the empty string for a file.  The
  macros `__line__' and `__file__' now work correctly even as the last
  token in an included file.


But yes, this means that trace output for any macro that spanned multiple lines 
in the input file between the open and close parentheses now reports a 
different value in the trace output.  Therefore, I claim that autotest should 
somehow normalize the line number to be tolerant of the difference between M4 
1.4.7 and the soon-to-be-released 1.4.8.

If I get some time, I will look at patching autoconf test 4, but anyone else is 
welcome to beat me to it.

-- 
Eric Blake