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Diffstat (limited to 'contrib/perl5/ext/B/O.pm')
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diff --git a/contrib/perl5/ext/B/O.pm b/contrib/perl5/ext/B/O.pm deleted file mode 100644 index 2ef91ed..0000000 --- a/contrib/perl5/ext/B/O.pm +++ /dev/null @@ -1,86 +0,0 @@ -package O; -use B qw(minus_c save_BEGINs); -use Carp; - -sub import { - my ($class, $backend, @options) = @_; - eval "use B::$backend ()"; - if ($@) { - croak "use of backend $backend failed: $@"; - } - my $compilesub = &{"B::${backend}::compile"}(@options); - if (ref($compilesub) eq "CODE") { - minus_c; - save_BEGINs; - eval 'CHECK { &$compilesub() }'; - } else { - die $compilesub; - } -} - -1; - -__END__ - -=head1 NAME - -O - Generic interface to Perl Compiler backends - -=head1 SYNOPSIS - - perl -MO=Backend[,OPTIONS] foo.pl - -=head1 DESCRIPTION - -This is the module that is used as a frontend to the Perl Compiler. - -=head1 CONVENTIONS - -Most compiler backends use the following conventions: OPTIONS -consists of a comma-separated list of words (no white-space). -The C<-v> option usually puts the backend into verbose mode. -The C<-ofile> option generates output to B<file> instead of -stdout. The C<-D> option followed by various letters turns on -various internal debugging flags. See the documentation for the -desired backend (named C<B::Backend> for the example above) to -find out about that backend. - -=head1 IMPLEMENTATION - -This section is only necessary for those who want to write a -compiler backend module that can be used via this module. - -The command-line mentioned in the SYNOPSIS section corresponds to -the Perl code - - use O ("Backend", OPTIONS); - -The C<import> function which that calls loads in the appropriate -C<B::Backend> module and calls the C<compile> function in that -package, passing it OPTIONS. That function is expected to return -a sub reference which we'll call CALLBACK. Next, the "compile-only" -flag is switched on (equivalent to the command-line option C<-c>) -and a CHECK block is registered which calls CALLBACK. Thus the main -Perl program mentioned on the command-line is read in, parsed and -compiled into internal syntax tree form. Since the C<-c> flag is -set, the program does not start running (excepting BEGIN blocks of -course) but the CALLBACK function registered by the compiler -backend is called. - -In summary, a compiler backend module should be called "B::Foo" -for some foo and live in the appropriate directory for that name. -It should define a function called C<compile>. When the user types - - perl -MO=Foo,OPTIONS foo.pl - -that function is called and is passed those OPTIONS (split on -commas). It should return a sub ref to the main compilation function. -After the user's program is loaded and parsed, that returned sub ref -is invoked which can then go ahead and do the compilation, usually by -making use of the C<B> module's functionality. - -=head1 AUTHOR - -Malcolm Beattie, C<mbeattie@sable.ox.ac.uk> - -=cut |