More descriptive error for unknown perlio layers.

Subject: [PATCHES Bleadperl] Re: PerlIO - what all of you can all do.
Message-Id: <p04320401b632c4c3335b@[192.168.1.4]>

p4raw-id: //depot/perl@7650

diff --git a/perlio.c b/perlio.c
index 73e463a..e350fef 100644 (file)
--- a/perlio.c
+++ b/perlio.c
@@ -385,7 +385,7 @@ PerlIO_default_layer(I32 n)
            av_push(PerlIO_layer_av,SvREFCNT_inc(layer));
           }
          else
-          Perl_warn(aTHX_ "Unknown layer %.*s",(e-s),s);
+          Perl_warn(aTHX_ "perlio: unknown layer \"%.*s\"",(e-s),s);
          s = e;
         }
       }

diff --git a/pod/perldiag.pod b/pod/perldiag.pod
index 2fe63ba..9baf175 100644 (file)
--- a/pod/perldiag.pod
+++ b/pod/perldiag.pod
@@ -2584,6 +2584,15 @@ the problem, however, you will get the same error message each time
 you run Perl.  How to really fix the problem can be found in
 L<perllocale> section B<LOCALE PROBLEMS>.
 
+=item perlio: unknown layer "%s"
+
+(S) An attempt was made to push an unknown layer onto the Perl I/O
+system.  (Layers take care of transforming data between external and
+internal representations.)  Note that some layers, such as C<mmap>,
+are not supported in all environments.  If your program didn't
+explicitly request the failing operation, it may be the result of the
+value of the environment variable PERLIO.
+
 =item Permission denied
 
 (F) The setuid emulator in suidperl decided you were up to no good.