Check if all used modules are use'ed

[Sewi]

Dear Monks,

Is there any (script|module|etc.) which reads a Perl script and complains about every module being used in the source but not imported using "use Module;"?

Sample:

use My::Foo; # Foo is using My::Bar

$x = My::Bar->new;

Perl will run this source without complaining - until every usage of My::Bar and the "use My::Bar" are removed from Foo.pm.

Thanks

[Corion]

I would assume that Module::Scandeps can do that. Alternatively, if you are worried about implicit loading of modules, I would just grep for everything that looks like a class name (/\b(\w+(?:'|::)(?:\w+(?:'|::)?)*/), and see where else that shows up. Note that use $module isn't sufficient, as there are many other "loader-style" modules, like if.

[Sewi]

scandeps doesn't work:

scandeps -e 'print $Foo::Bar::x'
No modules found!

and

use File::Spec::Unix; print $Foo::Bar::x; Bar::Baz->new'
'File::Spec::Unix' => '3.33',

[Anonymous Monk]

scandeps isn't lint :)

$ perl -MO=Xref -e " print $Foo::Bar::x "  | perl -ne " $f++ if /Subro
+utine..main/; print if $f "
-e syntax OK
  Subroutine (main)
    Package Foo::Bar
      $x                1

[JavaFan]

No, there is not such a script.

Take the following code, which module is used, but not imported?

#!/usr/bin/perl

use strict;
use warnings;
my $class1 = $ARGV[rand @ARGV];
my $class2 = $ARGV[rand @ARGV];
$class1 =~ s{::}{/}g;
require "$class1.pm";
$class2->method();
__END__

Even if you know the arguments, you still don't know which module is going to be used, and whether it's used without being required.

[Sewi]

Finding all special cases would require a package/namespace list from a running task.

Any solution finding the basic things would be ok as there are very few (if any) code pieces with dynamic dependencies in this project.

[Tux]

Not the way you describe the wish, but I've had enormous help of Devel::TraceUse which will show - when the program finishes - a list of modules actually loaded with their versions.

[CountZero]

Just run the program through its paces and see if you get any errors. Of course your test suite will discover such errors quickly.

I am more worried about modules "use"d but never used, because that is a waste of memory, processing power and time.

[Sewi]

All web scripte are running in a persistant interpreter (mod_perl/FastCGI), every module is used sooner or later.

Problems start when a script is called which doesn't use a used module and no other script has pre-loaded (use'd) the module before.