Do not call make for noop overrides.

1) Detect if target is noop when parsing debian/rules.
2) If override target is noop, do not call make for it.

diff --git a/dh b/dh
index 862dc25b7c2757037246bd0ad98c11d5dc3e80bd..b407148b9f5ee6e9dad7ecef376bf11b81915bf6 100755 (executable)
--- a/dh
+++ b/dh
@@ -540,30 +540,44 @@ sub run {
        # Check for override targets in debian/rules and
        # run them instead of running the command directly.
        my $override_command;
-       if (rules_explicit_target("override_".$command)) {
+       my $has_explicit_target = rules_explicit_target("override_".$command);
+       if (defined $has_explicit_target) {
                $override_command=$command;
-               # This passes the options through to commands called
-               # inside the target.
-               $ENV{DH_INTERNAL_OPTIONS}=join("\x1e", @options);
-               $command="debian/rules";
-               @options="override_".$override_command;
+               # Check if target isn't noop
+               if ($has_explicit_target) {
+                       # This passes the options through to commands called
+                       # inside the target.
+                       $ENV{DH_INTERNAL_OPTIONS}=join("\x1e", @options);
+                       $command="debian/rules";
+                       @options="override_".$override_command;
+               }
+               else {
+                       $command = undef;
+               }
        }
        else {
                # Pass additional command options if any
                unshift @options, @{$command_opts{$command}} if exists $command_opts{$command};
        }
 
-       # 3 space indent lines the command being run up under the 
-       # sequence name after "dh ".
-       print "   ".escape_shell($command, @options)."\n";
+       if (defined $command) {
+               # 3 space indent lines the command being run up under the 
+               # sequence name after "dh ".
+               print "   ".escape_shell($command, @options)."\n";
+       }
+       else {
+               print "   ", "# Skipping ", $override_command, " - empty override", "\n";
+       }
 
        if (! $dh{NO_ACT}) {
-               my $ret=system($command, @options);
-               if ($ret >> 8 != 0) {
-                       exit $ret >> 8;
-               }
-               elsif ($ret) {
-                       exit 1;
+               if (defined $command) {
+                       my $ret=system($command, @options);
+                       if ($ret >> 8 != 0) {
+                               exit $ret >> 8;
+                       }
+                       elsif ($ret) {
+                               exit 1;
+                       }
                }
 
                if (defined $override_command) {
@@ -589,11 +603,14 @@ my $rules_parsed;
 sub rules_explicit_target {
        # Checks if a specified target exists as an explicit target
        # in debian/rules. 
+       # undef is returned if target does not exist, 0 if target is noop
+       # and 1 if target has dependencies or executes commands.
        my $target=shift;
-       
-       if (! $rules_parsed) {  
+
+       if (! $rules_parsed) {
                my $processing_targets = 0;
                my $not_a_target = 0;
+               my $current_target;
                open(MAKE, "LC_ALL=C make -Rrnpsf debian/rules debhelper-fail-me 2>/dev/null |");
                while (<MAKE>) {
                        if ($processing_targets) {
@@ -601,12 +618,26 @@ sub rules_explicit_target {
                                        $not_a_target = 1;
                                }
                                else {
-                                       if (!$not_a_target && /^([^#:]+)::?/) {
-                                               # Target is defined.
-                                               # NOTE: if it is a depenency
-                                               # of .PHONY it will be
-                                               # defined too but that's ok.
-                                               $targets{$1} = 1;
+                                       if (!$not_a_target && /^([^#:]+)::?\s*(.*)$/) {
+                                               # Target is defined. NOTE: if it is a depenency of
+                                               # .PHONY it will be defined too but that's ok.
+                                               # $2 contains target dependencies if any.
+                                               $current_target = $1;
+                                               $targets{$current_target} = ($2) ? 1 : 0;
+                                       }
+                                       else {
+                                               if (defined $current_target) {
+                                                       if (/^#/) {
+                                                               # Check if target has commands to execute
+                                                               if (/^#\s*commands to execute/) {
+                                                                       $targets{$current_target} = 1;
+                                                               }
+                                                       }
+                                                       else {
+                                                               # Target parsed.
+                                                               $current_target = undef;
+                                                       }
+                                               }
                                        }
                                        # "Not a target:" is always followed by
                                        # a target name, so resetting this one
@@ -621,7 +652,7 @@ sub rules_explicit_target {
                $rules_parsed = 1;
        }
 
-       return exists $targets{$target};
+       return (exists $targets{$target}) ? $targets{$target} : undef;
 }
 
 }