This and other RFCs are available on the web at http://dev.perl.org/rfc/ =head1 TITLE linkable output mode =head1 VERSION Maintainer: David Nicol <[EMAIL PROTECTED]> Date: 17 Aug 2000 Last Modified: 20 Sep 2000 Mailing List: [EMAIL PROTECTED] Number: 121 Version: 2 Status: Frozen =head1 changes Addition of sentences concerning "perl without perl" =head1 ABSTRACT Perl5 offers a clunky interface for those who wish to call perl subroutines from within C programs. Herein is suggested a vastly simplified application programmer's interface: a C< -o > command line switch identical to that used in C compilers to produce a linkable object file. =head1 DESCRIPTION Two command line switches, -o and -oh, are added to perl6's invocation syntax. Perl invoked with the -o switch does not run its program, but rather pukes out an "object file" same way gcc would if given a file full of C code. Perl invoked with the -oh switch does not run its program, but rather pukes out a "header file" suitable for inclusion into a C program, containing the correct linkage definitions for the object file created by the -o switch. The resulting object file must be linked with the perl library to work. The point is, the perl internals are effectively hidden from the programmer who wishes to use a feature available in perl from within a C program. Also, it becomes easier to generate a "stand-alone" deliverable which will work without a full Perl intallation, by linking the output of C< perl -o > into a simple main() and delivering the resulting linked binary along with a perl shared object library. Or by just doing something like this: perl -o deliverme.o deliverme.pl ld deliverme.o -o deliverme =head1 IMPLEMENTATION Given a nonprototyped subroutine, C<perl6 -o> will generate suitable wrapper code for all subroutines in the input file, as described in the L<perlcall> and L<perlembed> perldoc pages, and then pass this code (via a temporary file) to the same C compiler that was used to build perl. Given a perl6 subroutine with a fully described prototype, which amounts to a C struct structure, that structure (with its names if any) can be used as the parameter types of the resulting function call. A restricted return type described in terms of basic C data types can function as a C function return type. Perl functions that are already using restricted parameter lists and restricted return types are effectively doing their own type conversions, except between SV{STRING} and char*, but allowing C access to the SV{STRING} data type and functions can't be anything but good. Furthermore, the porting team will need to get very chummy with the linking system on the platform. =head1 REFERENCES my imagination perldoc perlembed perldoc perlcall
