The minimum Perl version was raised to 5.8.0 from 5.6.0 in commit
3a9802d601 (but not documented as
such until e8c2d79ec4, and not
actually *enforced* by our own configure script until, er, now)
in order to use Time::HiRes::stat.
Unfortunately, while the Time::HiRes *module* was added in 5.8.0, it
did not export a ‘stat’ function until 5.8.9. More precisely, this
feature was added to Time::HiRes in version 1.92 of that module; Perl
core 5.8.8 shipped Time::HiRes 1.86, 5.8.9 shipped 1.9715. The only
system I have convenient access to, that has older Perls installed,
offers me a choice of 5.8.8 or 5.10.1, so the new requirement means
I cannot test with 5.8.x anymore.
Per https://perldoc.perl.org/perlhist the release history of these
versions of Perl is, in chronological order,
5.8.0 2002-Jul-18
5.8.8 2006-Jan-31
5.10.0 2007-Dec-18
5.8.9 2008-Dec-14 <-- almost a year later than 5.10.0
5.10.1 2009-Aug-22
5.12.0 2010-Apr-12
Per https://perldoc.perl.org/perl5101delta the differences between
5.10.0 and 5.10.1 are small, and do not make me worry about
accidentally introducing code that works on my test boxes but not for
our users, unlike the gulf between 5.8.x and 5.10.x.
Requiring 5.10 will mean that we have access to Digest::SHA, the //
and //= operators, the regexp \K escape, and ‘state’ variables
(lexical scope, persistent value) all of which I can think
of uses for (but none of them are actually used in this patch).
Putting it all together, I think a requirement bump to version 5.10.0
is justified. We are already chopping off the trailing edge at 2006
due to the requirement for M4 1.4.8 (/de facto/ since 2.70) and late
2007 is still 15 years ago.
This patch also makes configure search $PATH for executables named
‘perl5*’ and ‘perl-5.*’ if bare ‘perl’ is too old. To do this, it
introduces a helper macro AClocal_PATH_PROG_GLOBS_FEATURE_CHECK, which
I would *like* to promote to a new Autoconf feature, but I got stuck
on quoting issues — see comments in m4/perl-time-hires.m4.
* NEWS: Document requirement for Perl 5.10.
* m4/perl-time-hires.m4: New file.
* configure.ac: Use AC_PATH_PERL_WITH_TIME_HIRES_STAT to probe for
perl.
* build-aux/fetch.pl (fetch): For .pm files fetched from Automake,
rewrite “use 5.006” to “use 5.010”.
* build-aux/help-extract.pl
* lib/Autom4te/C4che.pm
* lib/Autom4te/ChannelDefs.pm
* lib/Autom4te/Channels.pm
* lib/Autom4te/Config.pm
* lib/Autom4te/Configure_ac.pm
* lib/Autom4te/FileUtils.pm
* lib/Autom4te/General.pm
* lib/Autom4te/Getopt.pm
* lib/Autom4te/Request.pm
* lib/Autom4te/XFile.pm
* tests/mktests.pl: Change “use 5.006” to “use 5.010”.
61901a1a14