From: Malcolm Beattie <mbeattie@sable.ox.ac.uk>
Date: Mon, 15 Sep 1997 14:09:11 +0000 (+0000)
Subject: Add undefined-subs option to Lint.pm.
X-Git-Url: http://git.shadowcat.co.uk/gitweb/gitweb.cgi?a=commitdiff_plain;h=2938739d2e019a7e34b70a9c71ba3903201f6d6d;p=p5sagit%2Fp5-mst-13.2.git

Add undefined-subs option to Lint.pm.

p4raw-id: //depot/perlext/Compiler@65
---

diff --git a/B/Lint.pm b/B/Lint.pm
index 3b4ea7e..d9659f9 100644
--- a/B/Lint.pm
+++ b/B/Lint.pm
@@ -67,6 +67,15 @@ lives in a non-current package but begins with an underscore ("_").
 Warnings aren't issued for the special case of the single character
 name "_" by itself (e.g. $_ and @_).
 
+=item B<undefined-subs>
+
+This option warns whenever an undefined subroutine is invoked.
+This option will only catch explicitly invoked subroutines such
+as C<foo()> and not indirect invocations such as C<&$subref()>
+or C<$obj-E<gt>meth()>. Note that some programs or modules delay
+definition of subs until runtime by means of the AUTOLOAD
+mechanism.
+
 =item B<all>
 
 Turn all warnings on.
@@ -129,7 +138,7 @@ my %valid_check;
 BEGIN {
     map($valid_check{$_}++,
 	qw(context implicit_read implicit_write dollar_underscore
-	   private_names));
+	   private_names undefined_subs));
 }
 
 # Debugging options
@@ -239,6 +248,17 @@ sub B::GVOP::lint {
 	    warning('Illegal reference to private name %s', $gv->NAME);
 	}
     }
+    if ($check{undefined_subs}) {
+	if ($op->ppaddr eq "pp_gv" && $op->next->ppaddr eq "pp_entersub") {
+	    my $gv = $op->gv;
+	    my $subname = $gv->STASH->NAME . "::" . $gv->NAME;
+	    no strict 'refs';
+	    if (!defined(&$subname)) {
+		$subname =~ s/^main:://;
+		warning('Undefined subroutine %s called', $subname);
+	    }
+	}
+    }
 }
 
 sub B::GV::lintcv {