sub generate_traceevent_regex()

in trace/postprocess/trace-pagealloc-postprocess.pl [91:128]

• 32 lines of code
• 7 McCabe index (conditional complexity)

sub generate_traceevent_regex {
	my $event = shift;
	my $default = shift;
	my $regex;

	# Read the event format or use the default
	if (!open (FORMAT, "/sys/kernel/debug/tracing/events/$event/format")) {
		$regex = $default;
	} else {
		my $line;
		while (!eof(FORMAT)) {
			$line = <FORMAT>;
			if ($line =~ /^print fmt:\s"(.*)",.*/) {
				$regex = $1;
				$regex =~ s/%p/\([0-9a-f]*\)/g;
				$regex =~ s/%d/\([-0-9]*\)/g;
				$regex =~ s/%lu/\([0-9]*\)/g;
			}
		}
	}

	# Verify fields are in the right order
	my $tuple;
	foreach $tuple (split /\s/, $regex) {
		my ($key, $value) = split(/=/, $tuple);
		my $expected = shift;
		if ($key ne $expected) {
			print("WARNING: Format not as expected '$key' != '$expected'");
			$regex =~ s/$key=\((.*)\)/$key=$1/;
		}
	}

	if (defined shift) {
		die("Fewer fields than expected in format");
	}

	return $regex;
}