Re: [RFC PATCH]: autom4te: report subsecond timestamp support in --version

[Jacob Bachmeyer]

Zack Weinberg wrote:
> The Automake test suite wants this in order to know if it’s safe to
> reduce the length of various delays for the purpose of ensuring files
> in autom4te.cache are newer than the corresponding source files.
>
> * lib/Autom4te/FileUtils.pm: Provide (but do not export) a flag
>   $subsecond_mtime, indicating whether the ‘mtime’ function reports
>   modification time with precision greater than one second.
>   Reorganize commentary and import logic for clarity.  Add
>   configuration for emacs’ perl-mode to the bottom of the file.
>   

Now that I have seen the actual patch, yes, this test should be 
accurate.  The test in the main autom4te script will also work, even if 
there is a mismatch between the script and its library, since Perl 
accepts a fully-qualified variable name even if that variable has never 
been declared; its value is undef, which is falsish in Boolean context.

> * bin/autom4te.in ($version): If $Autom4te::FileUtils::subsecond_mtime
>   is true, add the text “ (subsecond timestamps supported)” to the
>   first line of --version output.
>   

This appears to be misaligned with the GNU Coding Standards, which 
states:  "The first line is meant to be easy for a program to parse; the 
version number proper starts after the last space."

Perhaps the best option would be to conditionally add a line "This 
autom4te supports subsecond timestamps." after the license notice?


-- Jacob