Smart debian/rules parser for dh.

This parser is based on the output which make -p emits. It's a bit
more slower due to the need to run make itself but it is not dumb.

Signed-off-by: Modestas Vainius <modestas@vainius.eu>

1 files changed, 22 insertions, 6 deletions

diff --git a/dh b/dh
index 4191d0be..25ca87de 100755
--- a/dh
+++ b/dh
@@ -503,17 +503,33 @@ my $rules_parsed;
 sub rules_explicit_target {
 	# Checks if a specified target exists as an explicit target
 	# in debian/rules. 
-	# Currently this is accomplished via a stupid makefile parser.
 	my $target=shift;
+	my $processing_targets = 0;
+	my $not_a_target = 0;
 	
 	if (! $rules_parsed) {	
-		open(IN, "<debian/rules") || warning("dh cannot read debian/rules: $!");
-		while (<IN>) {
-			if (/^([a-zA-Z_]+):/) {
-				$targets{$1}=1;
+		open(MAKE, "make -Rrnpsf debian/rules debhelper-fail-me 2>/dev/null |");
+		while (<MAKE>) {
+			if ($processing_targets) {
+				if (/^# Not a target:/) {
+					$not_a_target = 1;
+				} else {
+					if (!$not_a_target && /^([^#:]+)::?/ && !exists $targets{$1}) {
+						# Target is defined.
+						# NOTE: if it is a depenency of .PHONY it will be
+						# defined too but that's ok.
+						$targets{$1} = 1;
+					}
+					# "Not a target:" is always followed by a target name,
+					# so resetting this one here is safe.
+					$not_a_target = 0;
+				}
+			} elsif (/^# Files$/) {
+				$processing_targets = 1;
 			}
 		}
-		close IN;
+		close MAKE;
+		$rules_parsed = 1;
 	}
 
 	return exists $targets{$target};