I suspect (but don't know for sure) that your "bombs my machine" problem is due to the cyclic nature of:
run script ... load module ... run B::Xref ... run script ... load module ... run B::Xref ... ad infinitum.
There's some other (potential) issues, which include: you're currently finding all modules using @ARGV, not just the ones loaded before your module; splitting the output from B::Xref on whitespace when pathnames may contain whitespace; portability of /dev/null; assuming modules have a .pm extension.
I created module PM::1082204::Log::Reproducible in ~/tmp/PM/1082204/Log/.
This is intended to mirror your Log::Reproducible.
Here's some notes:
-
I've used a BEGIN block, instead of a subroutine called from import(), so that there's no reliance on import() being called and the @ARGV checks are done first.
-
I've taken the code from the beginning of the calling script (up to, but not including, the use Log::Reproducible) and saved to a File::Temp temporary file.
B::Xref operates on this temporary file which fixes the cyclic/infinite loop issue mentioned above.
-
I've used IPC::Open3 to deal with the /dev/null issue: STDERR output is accessible from <CERR> but that filehandle isn't read.
-
B::Xref discards a leading './' in the filename path but retains instances of embedded '/./'.
I've handled this (e.g. /^(?:\.[\\\/]?)?(.*)$/) but there may be better ways to do this.
-
There's quite a few tweaks I could envisage you making to this; the code here should at least provide a framework as a starting point.
Here's the PM::1082204::Log::Reproducible code:
package PM::1082204::Log::Reproducible;
use 5.010;
use strict;
use warnings;
use autodie;
use File::Temp ();
use IPC::Open3;
BEGIN {
my $code = do { open my $fh, '<', $0; local $/; <$fh> };
my ($code_to_test) = $code =~ /(\A .*?) use \s+ @{[__PACKAGE__]}/s
+x;
my ($temp_fh, $temp_filename) = File::Temp::tempfile();
print $temp_fh $code_to_test;
local(*CIN, *COUT, *CERR);
my $cmd = "$^X -MO=Xref,-r $temp_filename";
my $pid = open3(\*CIN, \*COUT, \*CERR, $cmd);
my $re = '(?:' . join('|' => map { /^(?:\.[\\\/]?)?(.*)$/; "\Q$1"
+} @INC)
. ')[\\\/]?(\S+?)(?:\.\S+)?\s';
my %argv_modules;
for (<COUT>) {
next unless /\@\s+ARGV/;
(my $module) = /$re/;
$module =~ s{[\\\/]}{::}g;
++$argv_modules{$module};
}
waitpid $pid, 0;
my @warn_modules = sort keys %argv_modules;
if (@warn_modules) {
warn "WARNING:\n",
"Modules using'\@ARGV' before " . __PACKAGE__ . " loaded:\
+n";
warn "\t$_\n" for @warn_modules;
}
}
1;
In addition, the Qwerty module, in ~/tmp/PM/1082204/Log/X X/, tests for pathnames with whitespace:
package Qwerty;
use 5.010;
use strict;
use warnings;
sub xxx {
say "ARGV not empty." if @ARGV;
}
1;
And, the ModuleWithoutPmExtension, in ~/tmp/, tests pretty much what it says:
package ModuleWithoutPmExtension;
sub test {
print "I'm ", __PACKAGE__, "\n";
print "\@ARGV has elements.\n" if @ARGV;
}
1;
I ran the tests from ~/tmp.
Here's pm_1082204_b_xref.pl:
#!/usr/bin/env perl
use strict;
use warnings;
BEGIN {
require 'ModuleWithoutPmExtension';
ModuleWithoutPmExtension::test();
}
use lib './../tmp/./PM/1082204/Log/X X';
use Qwerty;
{
use Getopt::Long;
use PM::1082204::Log::Reproducible;
}
use Getopt::Std;
Output:
I'm ModuleWithoutPmExtension
WARNING:
Modules using'@ARGV' before PM::1082204::Log::Reproducible loaded:
Getopt::Long
ModuleWithoutPmExtension
Qwerty
Getopt::Std isn't in the list.
If you load it earlier in the code, it does appear in the list.
