perl: use warnings instead of -w; consistent ordering of use, etc.

Per thread at:
https://lists.gnu.org/archive/html/automake-patches/2020-08/msg00009.html

* bin/aclocal.in: use warnings instead of #!...-w;
consistent ordering of basic "use" directives,
then BEGIN block,
then standard modules in ASCII order,
then Automake:: modules (not sort),
finally use vars.
Also sort @ISA lists and use qw(...) in ASCII order.
* bin/automake.in: likewise.
* lib/Automake/ChannelDefs.pm: likewise.
* lib/Automake/Channels.pm: likewise.
* lib/Automake/Condition.pm: likewise.
* lib/Automake/Config.in: likewise.
* lib/Automake/Configure_ac.pm: likewise.
* lib/Automake/DisjConditions.pm: likewise.
* lib/Automake/FileUtils.pm: likewise.
* lib/Automake/General.pm: likewise.
* lib/Automake/Getopt.pm: likewise.
* lib/Automake/Item.pm: likewise.
* lib/Automake/ItemDef.pm: likewise.
* lib/Automake/Language.pm: likewise.
* lib/Automake/Location.pm: likewise.
* lib/Automake/Options.pm: likewise.
* lib/Automake/Rule.pm: likewise.
* lib/Automake/RuleDef.pm: likewise.
* lib/Automake/VarDef.pm: likewise.
* lib/Automake/Variable.pm: likewise.
* lib/Automake/Version.pm: likewise.
* lib/Automake/Wrap.pm: likewise.
* lib/Automake/XFile.pm: remove unnecessary imports of
Carp, DynaLoader, and File::Basename.

23 files changed, 114 insertions, 69 deletions

diff --git a/bin/aclocal.in b/bin/aclocal.in
index b61fed818..c968bd710 100644
--- a/bin/aclocal.in
+++ b/bin/aclocal.in
@@ -1,4 +1,4 @@
-#!@PERL@ -w
+#!@PERL@
 # aclocal - create aclocal.m4 by scanning configure.ac      -*- perl -*-
 # @configure_input@
 # Copyright (C) 1996-2020 Free Software Foundation, Inc.
@@ -19,13 +19,18 @@
 # Written by Tom Tromey <tromey@redhat.com>, and
 # Alexandre Duret-Lutz <adl@gnu.org>.
 
+use 5.006;
+use strict;
+use warnings FATAL => 'all';
+
 BEGIN
 {
   unshift (@INC, '@datadir@/@PACKAGE@-@APIVERSION@')
     unless $ENV{AUTOMAKE_UNINSTALLED};
 }
 
-use strict;
+use File::Basename;
+use File::Path ();
 
 use Automake::Config;
 use Automake::General;
@@ -34,8 +39,6 @@ use Automake::Channels;
 use Automake::ChannelDefs;
 use Automake::XFile;
 use Automake::FileUtils;
-use File::Basename;
-use File::Path ();
 
 # Some globals.
 
diff --git a/bin/automake.in b/bin/automake.in
index c12078711..1e4ccc8df 100644
--- a/bin/automake.in
+++ b/bin/automake.in
@@ -1,4 +1,4 @@
-#!@PERL@ -w
+#!@PERL@
 # automake - create Makefile.in from Makefile.am            -*- perl -*-
 # @configure_input@
 # Copyright (C) 1994-2020 Free Software Foundation, Inc.
@@ -22,7 +22,9 @@
 
 package Automake;
 
+use 5.006;
 use strict;
+use warnings FATAL => 'all';
 
 BEGIN
 {
@@ -39,6 +41,10 @@ BEGIN
   $ENV{'SHELL'} = '@SHELL@' if exists $ENV{'DJDIR'};
 }
 
+use Carp;
+use File::Basename;
+use File::Spec;
+
 use Automake::Config;
 BEGIN
 {
@@ -66,9 +72,6 @@ use Automake::Rule;
 use Automake::RuleDef;
 use Automake::Wrap 'makefile_wrap';
 use Automake::Language;
-use File::Basename;
-use File::Spec;
-use Carp;
 
 ## ----------------------- ##
 ## Subroutine prototypes.  ##
diff --git a/lib/Automake/ChannelDefs.pm b/lib/Automake/ChannelDefs.pm
index 2ee6dd8ef..37c5a2715 100644
--- a/lib/Automake/ChannelDefs.pm
+++ b/lib/Automake/ChannelDefs.pm
@@ -15,17 +15,6 @@
 
 package Automake::ChannelDefs;
 
-use Automake::Config;
-BEGIN
-{
-  if ($perl_threads)
-    {
-      require threads;
-      import threads;
-    }
-}
-use Automake::Channels;
-
 =head1 NAME
 
 Automake::ChannelDefs - channel definitions for Automake and helper functions
@@ -57,10 +46,22 @@ shorthand function to output on specific channels.
 
 use 5.006;
 use strict;
+use warnings FATAL => 'all';
+
 use Exporter;
 
-use vars qw (@ISA @EXPORT);
+use Automake::Channels;
+use Automake::Config;
+BEGIN
+{
+  if ($perl_threads)
+    {
+      require threads;
+      import threads;
+    }
+}
 
+use vars qw (@EXPORT @ISA);
 @ISA = qw (Exporter);
 @EXPORT = qw (&prog_error &error &fatal &verb
 	      &switch_warning &parse_WARNINGS &parse_warnings);
diff --git a/lib/Automake/Channels.pm b/lib/Automake/Channels.pm
index 5fb01f550..7cc7ffdf6 100644
--- a/lib/Automake/Channels.pm
+++ b/lib/Automake/Channels.pm
@@ -68,12 +68,13 @@ etc.) that can also be overridden on a per-message basis.
 
 use 5.006;
 use strict;
-use Exporter;
+use warnings FATAL => 'all';
+
 use Carp;
+use Exporter;
 use File::Basename;
 
-use vars qw (@ISA @EXPORT %channels $me);
-
+use vars qw (@EXPORT @ISA %channels $me);
 @ISA = qw (Exporter);
 @EXPORT = qw ($exit_code $warnings_are_errors
 	      &reset_local_duplicates &reset_global_duplicates
diff --git a/lib/Automake/Condition.pm b/lib/Automake/Condition.pm
index 764411691..072602afe 100644
--- a/lib/Automake/Condition.pm
+++ b/lib/Automake/Condition.pm
@@ -17,12 +17,14 @@ package Automake::Condition;
 
 use 5.006;
 use strict;
+use warnings FATAL => 'all';
+
 use Carp;
+use Exporter;
 
-require Exporter;
-use vars '@ISA', '@EXPORT_OK';
-@ISA = qw/Exporter/;
-@EXPORT_OK = qw/TRUE FALSE reduce_and reduce_or/;
+use vars qw (@EXPORT_OK @ISA);
+@ISA = qw (Exporter);
+@EXPORT_OK = qw (TRUE FALSE reduce_and reduce_or);
 
 =head1 NAME
 
diff --git a/lib/Automake/Config.in b/lib/Automake/Config.in
index f79b8cd40..d44e0ab94 100644
--- a/lib/Automake/Config.in
+++ b/lib/Automake/Config.in
@@ -16,10 +16,12 @@
 # along with this program.  If not, see <https://www.gnu.org/licenses/>.
 
 package Automake::Config;
-use strict;
 
 use 5.006;
-require Exporter;
+use strict;
+use warnings FATAL => 'all';
+
+use Exporter;
 
 our @ISA = qw (Exporter);
 our @EXPORT = qw ($APIVERSION $PACKAGE $PACKAGE_BUGREPORT $VERSION
diff --git a/lib/Automake/Configure_ac.pm b/lib/Automake/Configure_ac.pm
index d60191b88..0d9b465e6 100644
--- a/lib/Automake/Configure_ac.pm
+++ b/lib/Automake/Configure_ac.pm
@@ -22,12 +22,14 @@ package Automake::Configure_ac;
 
 use 5.006;
 use strict;
+use warnings FATAL => 'all';
+
 use Exporter;
-use Automake::Channels;
-use Automake::ChannelDefs;
 
-use vars qw (@ISA @EXPORT);
+use Automake::ChannelDefs;
+use Automake::Channels;
 
+use vars qw (@EXPORT @ISA);
 @ISA = qw (Exporter);
 @EXPORT = qw (&find_configure_ac &require_configure_ac);
 
diff --git a/lib/Automake/DisjConditions.pm b/lib/Automake/DisjConditions.pm
index dbe311ebc..af9d1a955 100644
--- a/lib/Automake/DisjConditions.pm
+++ b/lib/Automake/DisjConditions.pm
@@ -17,8 +17,10 @@ package Automake::DisjConditions;
 
 use 5.006;
 use strict;
+use warnings FATAL => 'all';
+
 use Carp;
-use Automake::Condition qw/TRUE FALSE/;
+use Automake::Condition qw (TRUE FALSE);
 
 =head1 NAME
 
diff --git a/lib/Automake/FileUtils.pm b/lib/Automake/FileUtils.pm
index 40e236d4d..65f9216df 100644
--- a/lib/Automake/FileUtils.pm
+++ b/lib/Automake/FileUtils.pm
@@ -36,14 +36,16 @@ This perl module provides various general purpose file handling functions.
 
 use 5.006;
 use strict;
+use warnings FATAL => 'all';
+
 use Exporter;
 use File::stat;
 use IO::File;
+
 use Automake::Channels;
 use Automake::ChannelDefs;
 
-use vars qw (@ISA @EXPORT);
-
+use vars qw (@EXPORT @ISA);
 @ISA = qw (Exporter);
 @EXPORT = qw (&contents
 	      &find_file &mtime
diff --git a/lib/Automake/General.pm b/lib/Automake/General.pm
index dbb2138b6..ea7032cd1 100644
--- a/lib/Automake/General.pm
+++ b/lib/Automake/General.pm
@@ -17,10 +17,12 @@ package Automake::General;
 
 use 5.006;
 use strict;
+use warnings FATAL => 'all';
+
 use Exporter;
 use File::Basename;
 
-use vars qw (@ISA @EXPORT);
+use vars qw (@EXPORT @ISA);
 
 @ISA = qw (Exporter);
 @EXPORT = qw (&uniq &none $me);
diff --git a/lib/Automake/Getopt.pm b/lib/Automake/Getopt.pm
index f8dc0acaf..5d7d57bae 100644
--- a/lib/Automake/Getopt.pm
+++ b/lib/Automake/Getopt.pm
@@ -33,14 +33,16 @@ line options in conformance to the GNU Coding standards.
 use 5.006;
 use strict;
 use warnings FATAL => 'all';
+
+use Carp qw (confess croak);
 use Exporter ();
 use Getopt::Long ();
-use Automake::ChannelDefs qw/fatal/;
-use Carp qw/croak confess/;
 
-use vars qw (@ISA @EXPORT);
+use Automake::ChannelDefs qw (fatal);
+
+use vars qw (@EXPORT @ISA);
 @ISA = qw (Exporter);
-@EXPORT= qw/getopt/;
+@EXPORT = qw (getopt);
 
 =item C<parse_options (%option)>
 
diff --git a/lib/Automake/Item.pm b/lib/Automake/Item.pm
index 85e114d9d..aee23e778 100644
--- a/lib/Automake/Item.pm
+++ b/lib/Automake/Item.pm
@@ -17,7 +17,10 @@ package Automake::Item;
 
 use 5.006;
 use strict;
+use warnings FATAL => 'all';
+
 use Carp;
+
 use Automake::ChannelDefs;
 use Automake::DisjConditions;
 
diff --git a/lib/Automake/ItemDef.pm b/lib/Automake/ItemDef.pm
index debcaa521..995fb11eb 100644
--- a/lib/Automake/ItemDef.pm
+++ b/lib/Automake/ItemDef.pm
@@ -17,6 +17,8 @@ package Automake::ItemDef;
 
 use 5.006;
 use strict;
+use warnings FATAL => 'all';
+
 use Carp;
 
 =head1 NAME
diff --git a/lib/Automake/Language.pm b/lib/Automake/Language.pm
index 4d5fa8056..b85e0fa54 100644
--- a/lib/Automake/Language.pm
+++ b/lib/Automake/Language.pm
@@ -17,8 +17,10 @@ package Automake::Language;
 
 use 5.006;
 use strict;
+use warnings FATAL => 'all';
 
 use Class::Struct ();
+
 Class::Struct::struct (
 	# Short name of the language (c, f77...).
 	'name' => "\$",
diff --git a/lib/Automake/Location.pm b/lib/Automake/Location.pm
index 8e4d1c79f..611cd0220 100644
--- a/lib/Automake/Location.pm
+++ b/lib/Automake/Location.pm
@@ -16,6 +16,8 @@
 package Automake::Location;
 
 use 5.006;
+use strict;
+use warnings FATAL => 'all';
 
 =head1 NAME
 
diff --git a/lib/Automake/Options.pm b/lib/Automake/Options.pm
index 59e29c583..5e20a3410 100644
--- a/lib/Automake/Options.pm
+++ b/lib/Automake/Options.pm
@@ -17,14 +17,16 @@ package Automake::Options;
 
 use 5.006;
 use strict;
+use warnings FATAL => 'all';
+
 use Exporter;
+
 use Automake::Config;
 use Automake::ChannelDefs;
 use Automake::Channels;
 use Automake::Version;
 
-use vars qw (@ISA @EXPORT);
-
+use vars qw (@EXPORT @ISA);
 @ISA = qw (Exporter);
 @EXPORT = qw (option global_option
               set_option set_global_option
diff --git a/lib/Automake/Rule.pm b/lib/Automake/Rule.pm
index 35e7b273f..0227a85d1 100644
--- a/lib/Automake/Rule.pm
+++ b/lib/Automake/Rule.pm
@@ -17,7 +17,10 @@ package Automake::Rule;
 
 use 5.006;
 use strict;
+use warnings FATAL => 'all';
+
 use Carp;
+use Exporter;
 
 use Automake::Item;
 use Automake::RuleDef;
@@ -26,9 +29,9 @@ use Automake::Channels;
 use Automake::Options;
 use Automake::Condition qw (TRUE FALSE);
 use Automake::DisjConditions;
-require Exporter;
-use vars '@ISA', '@EXPORT', '@EXPORT_OK';
-@ISA = qw/Automake::Item Exporter/;
+
+use vars qw (@EXPORT @EXPORT_OK @ISA);
+@ISA = qw (Automake::Item Exporter);
 @EXPORT = qw (reset register_suffix_rule next_in_suffix_chain
 	      suffixes rules $KNOWN_EXTENSIONS_PATTERN
 	      depend %dependencies %actions register_action
diff --git a/lib/Automake/RuleDef.pm b/lib/Automake/RuleDef.pm
index d44f10819..091a78c50 100644
--- a/lib/Automake/RuleDef.pm
+++ b/lib/Automake/RuleDef.pm
@@ -17,13 +17,16 @@ package Automake::RuleDef;
 
 use 5.006;
 use strict;
+use warnings FATAL => 'all';
+
 use Carp;
+use Exporter;
+
 use Automake::ChannelDefs;
 use Automake::ItemDef;
 
-require Exporter;
-use vars '@ISA', '@EXPORT';
-@ISA = qw/Automake::ItemDef Exporter/;
+use vars qw (@EXPORT @ISA);
+@ISA = qw (Automake::ItemDef Exporter);
 @EXPORT = qw (&RULE_AUTOMAKE &RULE_USER);
 
 =head1 NAME
diff --git a/lib/Automake/VarDef.pm b/lib/Automake/VarDef.pm
index d258a8573..adeb6e299 100644
--- a/lib/Automake/VarDef.pm
+++ b/lib/Automake/VarDef.pm
@@ -17,13 +17,16 @@ package Automake::VarDef;
 
 use 5.006;
 use strict;
+use warnings FATAL => 'all';
+
 use Carp;
+use Exporter;
+
 use Automake::ChannelDefs;
 use Automake::ItemDef;
 
-require Exporter;
-use vars '@ISA', '@EXPORT';
-@ISA = qw/Automake::ItemDef Exporter/;
+use vars qw (@ISA @EXPORT);
+@ISA = qw (Automake::ItemDef Exporter);
 @EXPORT = qw (&VAR_AUTOMAKE &VAR_CONFIGURE &VAR_MAKEFILE
 	      &VAR_ASIS &VAR_PRETTY &VAR_SILENT &VAR_SORTED);
 
diff --git a/lib/Automake/Variable.pm b/lib/Automake/Variable.pm
index 363a3e0ed..4ec0dd4b0 100644
--- a/lib/Automake/Variable.pm
+++ b/lib/Automake/Variable.pm
@@ -17,7 +17,10 @@ package Automake::Variable;
 
 use 5.006;
 use strict;
+use warnings FATAL => 'all';
+
 use Carp;
+use Exporter;
 
 use Automake::Channels;
 use Automake::ChannelDefs;
@@ -29,9 +32,8 @@ use Automake::DisjConditions;
 use Automake::General 'uniq';
 use Automake::Wrap 'makefile_wrap';
 
-require Exporter;
-use vars '@ISA', '@EXPORT', '@EXPORT_OK';
-@ISA = qw/Automake::Item Exporter/;
+use vars qw (@EXPORT @EXPORT_OK @ISA);
+@ISA = qw (Automake::Item Exporter);
 @EXPORT = qw (err_var msg_var msg_cond_var reject_var
 	      var rvar vardef rvardef
 	      variables
diff --git a/lib/Automake/Version.pm b/lib/Automake/Version.pm
index c2722c061..16cdfb699 100644
--- a/lib/Automake/Version.pm
+++ b/lib/Automake/Version.pm
@@ -17,6 +17,8 @@ package Automake::Version;
 
 use 5.006;
 use strict;
+use warnings FATAL => 'all';
+
 use Automake::ChannelDefs;
 
 =head1 NAME
diff --git a/lib/Automake/Wrap.pm b/lib/Automake/Wrap.pm
index 0640cc9a2..c821b8b99 100644
--- a/lib/Automake/Wrap.pm
+++ b/lib/Automake/Wrap.pm
@@ -17,11 +17,13 @@ package Automake::Wrap;
 
 use 5.006;
 use strict;
+use warnings FATAL => 'all';
 
-require Exporter;
-use vars '@ISA', '@EXPORT_OK';
-@ISA = qw/Exporter/;
-@EXPORT_OK = qw/wrap makefile_wrap/;
+use Exporter;
+
+use vars qw (@EXPORT_OK @ISA);
+@ISA = qw (Exporter);
+@EXPORT_OK = qw (wrap makefile_wrap);
 
 =head1 NAME
 
diff --git a/lib/Automake/XFile.pm b/lib/Automake/XFile.pm
index 7d54404f0..5284faa5d 100644
--- a/lib/Automake/XFile.pm
+++ b/lib/Automake/XFile.pm
@@ -71,23 +71,20 @@ and C<getlines> methods to translate C<\r\n> to C<\n>.
 
 use 5.006;
 use strict;
-use vars qw($VERSION @EXPORT @EXPORT_OK $AUTOLOAD @ISA);
-use Carp;
+use warnings FATAL => 'all';
+
 use Errno;
+use Exporter;
 use IO::File;
-use File::Basename;
+
 use Automake::ChannelDefs;
-use Automake::Channels qw(msg);
+use Automake::Channels qw (msg);
 use Automake::FileUtils;
 
-require Exporter;
-require DynaLoader;
-
-@ISA = qw(IO::File Exporter DynaLoader);
-
-$VERSION = "1.2";
-
+use vars qw ($AUTOLOAD @EXPORT @EXPORT_OK @ISA $VERSION);
+@ISA = qw(Exporter IO::File);
 @EXPORT = @IO::File::EXPORT;
+$VERSION = "1.2";
 
 eval {
   # Make all Fcntl O_XXX and LOCK_XXX constants available for importing