scripts: Use the state keyword

This moves the variables closer to the block they are being used in. And
protects them from external access.

debian/changelog

@@ -8,6 +8,7 @@ dpkg (1.18.1) UNRELEASED; urgency=low
   * Perl modules:
     - Add missing strict and warnings pragmas for submodules.
     - Use non-destructive substitutions inside map.
+    - Use the state keyword to simplify the code.
 
   [ Updated programs translations ]
   * German (Sven Joachim).

scripts/Dpkg/Arch.pm

@@ -17,6 +17,7 @@ package Dpkg::Arch;
 
 use strict;
 use warnings;
+use feature qw(state);
 
 our $VERSION = '0.01';
 our @EXPORT_OK = qw(
@@ -59,31 +60,31 @@ my %abibits;
 my %debtriplet_to_debarch;
 my %debarch_to_debtriplet;
 
+sub get_raw_build_arch()
 {
-    my $build_arch;
-    my $host_arch;
-    my $gcc_host_gnu_type;
+    state $build_arch;
 
-    sub get_raw_build_arch()
-    {
-	return $build_arch if defined $build_arch;
+    return $build_arch if defined $build_arch;
 
-	# Note: We *always* require an installed dpkg when inferring the
-	# build architecture. The bootstrapping case is handled by
-	# dpkg-architecture itself, by avoiding computing the DEB_BUILD_
-	# variables when they are not requested.
+    # Note: We *always* require an installed dpkg when inferring the
+    # build architecture. The bootstrapping case is handled by
+    # dpkg-architecture itself, by avoiding computing the DEB_BUILD_
+    # variables when they are not requested.
 
-	$build_arch = `dpkg --print-architecture`;
-	syserr('dpkg --print-architecture failed') if $? >> 8;
+    $build_arch = `dpkg --print-architecture`;
+    syserr('dpkg --print-architecture failed') if $? >> 8;
 
-	chomp $build_arch;
-	return $build_arch;
-    }
+    chomp $build_arch;
+    return $build_arch;
+}
 
-    sub get_build_arch()
-    {
-	return Dpkg::BuildEnv::get('DEB_BUILD_ARCH') || get_raw_build_arch();
-    }
+sub get_build_arch()
+{
+    return Dpkg::BuildEnv::get('DEB_BUILD_ARCH') || get_raw_build_arch();
+}
+
+{
+    my $gcc_host_gnu_type;
 
     sub get_gcc_host_gnu_type()
     {
@@ -101,6 +102,8 @@ my %debarch_to_debtriplet;
 
     sub get_raw_host_arch()
     {
+        state $host_arch;
+
 	return $host_arch if defined $host_arch;
 
 	$gcc_host_gnu_type = get_gcc_host_gnu_type();
@@ -128,11 +131,11 @@ my %debarch_to_debtriplet;
 
 	return $host_arch;
     }
+}
 
-    sub get_host_arch()
-    {
-	return Dpkg::BuildEnv::get('DEB_HOST_ARCH') || get_raw_host_arch();
-    }
+sub get_host_arch()
+{
+    return Dpkg::BuildEnv::get('DEB_HOST_ARCH') || get_raw_host_arch();
 }
 
 sub get_valid_arches()

scripts/Dpkg/Shlibs.pm

@@ -18,6 +18,7 @@ package Dpkg::Shlibs;
 
 use strict;
 use warnings;
+use feature qw(state);
 
 our $VERSION = '0.02';
 our @EXPORT_OK = qw(
@@ -48,9 +49,9 @@ use constant DEFAULT_MULTILIB_PATH =>
 my @librarypaths;
 my $librarypaths_init;
 
-my %visited;
 sub parse_ldso_conf {
     my $file = shift;
+    state %visited;
     local $_;
 
     open my $fh, '<', $file or syserr(g_('cannot open %s'), $file);

scripts/Dpkg/Shlibs/Objdump.pm

@@ -17,6 +17,7 @@ package Dpkg::Shlibs::Objdump;
 
 use strict;
 use warnings;
+use feature qw(state);
 
 our $VERSION = '0.01';
 
@@ -82,41 +83,39 @@ sub has_object {
     return exists $self->{objects}{$objid};
 }
 
-{
-    my %format; # Cache of result
-    sub get_format {
-	my ($file, $objdump) = @_;
+sub get_format {
+    my ($file, $objdump) = @_;
+    state %format;
 
-	$objdump //= $OBJDUMP;
+    $objdump //= $OBJDUMP;
 
-	if (exists $format{$file}) {
-	    return $format{$file};
-	} else {
-	    my ($output, %opts, $pid, $res);
-	    local $_;
+    if (exists $format{$file}) {
+        return $format{$file};
+    } else {
+        my ($output, %opts, $pid, $res);
+        local $_;
 
-	    if ($objdump ne 'objdump') {
-		$opts{error_to_file} = '/dev/null';
-	    }
-	    $pid = spawn(exec => [ $objdump, '-a', '--', $file ],
-			 env => { LC_ALL => 'C' },
-			 to_pipe => \$output, %opts);
-	    while (<$output>) {
-		chomp;
-		if (/^\s*\S+:\s*file\s+format\s+(\S+)\s*$/) {
-		    $format{$file} = $1;
-		    $res = $format{$file};
-		    last;
-		}
-	    }
-	    close($output);
-	    wait_child($pid, nocheck => 1);
-	    if ($?) {
-		subprocerr('objdump') if $objdump eq 'objdump';
-		$res = get_format($file, 'objdump');
-	    }
-	    return $res;
-	}
+        if ($objdump ne 'objdump') {
+            $opts{error_to_file} = '/dev/null';
+        }
+        $pid = spawn(exec => [ $objdump, '-a', '--', $file ],
+                     env => { LC_ALL => 'C' },
+                     to_pipe => \$output, %opts);
+        while (<$output>) {
+            chomp;
+            if (/^\s*\S+:\s*file\s+format\s+(\S+)\s*$/) {
+                $format{$file} = $1;
+                $res = $format{$file};
+                last;
+            }
+        }
+        close($output);
+        wait_child($pid, nocheck => 1);
+        if ($?) {
+            subprocerr('objdump') if $objdump eq 'objdump';
+            $res = get_format($file, 'objdump');
+        }
+        return $res;
     }
 }
 

scripts/Dpkg/Vendor.pm

@@ -17,6 +17,7 @@ package Dpkg::Vendor;
 
 use strict;
 use warnings;
+use feature qw(state);
 
 our $VERSION = '1.01';
 our @EXPORT_OK = qw(
@@ -87,9 +88,9 @@ if there's no file for the given vendor.
 
 =cut
 
-my %VENDOR_CACHE;
 sub get_vendor_info(;$) {
     my $vendor = shift || 'default';
+    state %VENDOR_CACHE;
     return $VENDOR_CACHE{$vendor} if exists $VENDOR_CACHE{$vendor};
 
     my $file = get_vendor_file($vendor);
@@ -148,9 +149,9 @@ object.
 
 =cut
 
-my %OBJECT_CACHE;
 sub get_vendor_object {
     my $vendor = shift || get_current_vendor() || 'Default';
+    state %OBJECT_CACHE;
     return $OBJECT_CACHE{$vendor} if exists $OBJECT_CACHE{$vendor};
 
     my ($obj, @names);