[CC'd to dbi-dev@perl.org for discussion] On Tue, Sep 25, 2012 at 09:55:17PM +0200, Max Maischein wrote: > Hello Tim, > > I was looking at DynaLoader and AutoLoader, and found that some > old(er) versions of DynaLoader used AutoLoader, like the one > distributed with 5.10. Having an AUTOLOAD subroutine strikes me as > an ugly idea, and the easiest fix that works backwards for DBI > seemed to me to eliminate the inheritance from DynaLoader. That way, > DynaLoader can still inherit from AutoLoader (in old versions), but > the inheritance stops there.
> I've attached two patches that eliminate the inheritance from > DynaLoader and from Exporter. I hope eliminating the inheritance > from DynaLoader finds your approval. Eliminating the inheritance > from Exporter is somewhat more controversial as I use a feature of > Exporter that came into being only with Exporter 5.57, which is core > since 5.8.3. This would bump the minimum "pristine core" requirement > of DBI from 5.8.1 to 5.8.3, which you may or may not like. I think > eliminating unneccessary inheritance is a nice goal, but not at the > price of bumping the minimum Perl version. If you have other reasons > to raise the minimum Exporter version or don't see that as an > impediment. Maybe most people use CPAN to install DBI anyway and > thus don't care if a higher version of Exporter is a prerequisite. > > I've made my changes against DBI 1.622, because for some reason the > SVN checkout did fail cloning several times and then didn't pass > tests at all. On the upside, I built in a directory with whitespace > in the path and the build still worked. All tests still pass on my > machine with the changes. > > Anyway, I hope my changes to how DBI uses DynaLoader are in the > spirit of you like DynaLoader to be used. > > Thanks for writing and maintaining DBI, > -max Thanks Max. For the Exporter change, I don't have a strong opinion on bumping to minimum requirement to 5.8.3, but others might. For the DynaLoader change, I suspect it would break "static linking" (perl Makefile.PL LINKTYPE=static) which some people/environments may rely on. Tim. > >From 359091f215fcbd235a871898e42a23b9e438a4a4 Mon Sep 17 00:00:00 2001 > From: Max Maischein <cor...@corion.net> > Date: Tue, 25 Sep 2012 21:33:23 +0200 > Subject: [PATCH 2/2] Eliminate inheritance from Exporter. > > This requires Exporter 5.57, which came into core with Perl 5.8.3. > Currently, DBI only requires 5.8.1, so this may be undesireable. > --- > DBI.pm | 3 +-- > 1 files changed, 1 insertions(+), 2 deletions(-) > > diff --git a/DBI.pm b/DBI.pm > index badb6fd..acc6dda 100644 > --- a/DBI.pm > +++ b/DBI.pm > @@ -156,10 +156,9 @@ L<http://search.cpan.org/search?query=DBI&mode=all>. > > use Carp(); > use DynaLoader (); > -use Exporter (); > +use Exporter 'import'; > > BEGIN { > -@ISA = qw(Exporter); > *dl_load_flags = \&DynaLoader::dl_load_flags; > > # Make some utility functions available if asked for > -- > 1.6.5.1.1367.gcd48 > > >From 5cb368816753c526895a68aa411711e33675ac3a Mon Sep 17 00:00:00 2001 > From: Max Maischein <cor...@corion.net> > Date: Tue, 25 Sep 2012 21:32:19 +0200 > Subject: [PATCH 1/2] Eliminate inheritance from DynaLoader > > --- > DBI.pm | 7 ++++--- > 1 files changed, 4 insertions(+), 3 deletions(-) > > diff --git a/DBI.pm b/DBI.pm > index 9b39b14..badb6fd 100644 > --- a/DBI.pm > +++ b/DBI.pm > @@ -159,7 +159,8 @@ use DynaLoader (); > use Exporter (); > > BEGIN { > -@ISA = qw(Exporter DynaLoader); > +@ISA = qw(Exporter); > + *dl_load_flags = \&DynaLoader::dl_load_flags; > > # Make some utility functions available if asked for > @EXPORT = (); # we export nothing by default > @@ -251,12 +252,12 @@ $DBI::stderr = 2_000_000_000; # a very round number > below 2**31 > # then you haven't installed the DBI correctly. Read the README > # then install it again. > if ( $ENV{DBI_PUREPERL} ) { > - eval { bootstrap DBI } if $ENV{DBI_PUREPERL} == 1; > + eval { __PACKAGE__->DynaLoader::bootstrap( $VERSION ) } if > $ENV{DBI_PUREPERL} == 1; > require DBI::PurePerl if $@ or $ENV{DBI_PUREPERL} >= 2; > $DBI::PurePerl ||= 0; # just to silence "only used once" warnings > } > else { > - bootstrap DBI; > + __PACKAGE__->DynaLoader::bootstrap( $VERSION ); > } > > $EXPORT_TAGS{preparse_flags} = [ grep { /^DBIpp_\w\w_/ } keys > %{__PACKAGE__."::"} ]; > -- > 1.6.5.1.1367.gcd48 >
