NAME

    Alien::Base::Wrapper - Compiler and linker wrapper for Alien

VERSION

    version 0.04

SYNOPSIS

    From the command line:

     % perl -MAlien::Base::Wrapper=Alien::Foo,Alien::Bar -e cc -- -o foo.o -c foo.c
     % perl -MAlien::Base::Wrapper=Alien::Foo,Alien::Bar -e ld -- -o foo foo.o

    From Makefile.PL (non-dynamic):

     use ExtUtils::MakeMaker;
     use Alien::Base::Wrapper qw( Alien::Foo Alien::Bar !export );
     
     WriteMakefile(
       'NAME'              => 'Foo::XS',
       'VERSION_FROM'      => 'lib/Foo/XS.pm',
       'CONFIGURE_REQUIRES => {
         'ExtUtils::MakeMaker' => 6.52,
         'Alien::Foo'          => 0,
         'Alien::Bar'          => 0,
       },
       Alien::Base::Wrapper->mm_args,
     );

    From Makefile.PL (dynamic):

     use Devel::CheckLib qw( check_lib );
     use ExtUtils::MakeMaker 6.52;
     
     my @mm_args;
     my @libs;
     my %build_requires;
     
     if(check_lib( lib => [ 'foo' ] )
     {
       push @mm_args, LIBS => [ '-lfoo' ];
     }
     else
     {
       push @mm_args,
         CC => '$(FULLPERL) -MAlien::Base::Wrapper=Alien::Foo -e cc --',
         LD => '$(FULLPERL) -MAlien::Base::Wrapper=Alien::Foo -e ld --',
         BUILD_REQUIRES => {
           'Alien::Foo'           => 0,
           'Alien::Base::Wrapper' => 0,
         }
       ;
     }
    
     WriteMakefile(
       'NAME'         => 'Foo::XS',
       'VERSION_FROM' => 'lib/Foo/XS.pm',
       'CONFIGURE_REQUIRES => {
         'ExtUtils::MakeMaker' => 6.52,
       },
       @mm_args,
     );

DESCRIPTION

    This module acts as a wrapper around one or more Alien modules. It is
    designed to work with Alien::Base based aliens, but it should work with
    any Alien which uses the same essential API.

    In the first example (from the command line), this class acts as a
    wrapper around the compiler and linker that Perl is configured to use.
    It takes the normal compiler and linker flags and adds the flags
    provided by the Aliens specified, and then executes the command. It
    will print the command to the console so that you can see exactly what
    is happening.

    In the second example (from Makefile.PL non-dynamic), this class is
    used to generate the appropriate ExtUtils::MakeMaker (EUMM) arguments
    needed to WriteMakefile.

    In the third example (from Makefile.PL dynamic), we do a quick check to
    see if the simple linker flag -lfoo will work, if so we use that. If
    not, we use a wrapper around the compiler and linker that will use the
    alien flags that are known at build time. The problem that this form
    attempts to solve is that compiler and linker flags typically need to
    be determined at configure time, when a distribution is installed,
    meaning if you are going to use an Alien module then it needs to be a
    configure prerequisite, even if the library is already installed and
    easily detected on the operating system.

    The author of this module believes that the third (from Makefile.PL
    dynamic) form is somewhat unnecessary. Alien modules based on
    Alien::Base have a few prerequisites, but they are well maintained and
    reliable, so while there is a small cost in terms of extra
    dependencies, the overall reliability thanks to reduced overall
    complexity.

FUNCTIONS

 cc

     % perl -MAlien::Base::Wrapper=Alien::Foo -e cc -- cflags

    Invoke the C compiler with the appropriate flags from Alien::Foo and
    what is provided on the command line.

 ld

     % perl -MAlien::Base::Wrapper=Alien::Foo -e ld -- ldflags

    Invoke the linker with the appropriate flags from Alien::Foo and what
    is provided on the command line.

 mm_args

     my %args = Alien::Base::Wrapper->mm_args;

    Returns arguments that you can pass into WriteMakefile to compile/link
    against the specified Aliens.

 mb_args

     my %args = Alien::Base::Wrapper->mb_args;

    Returns arguments that you can pass into the constructor to
    Module::Build.

ENVIRONMENT

    Alien::Base::Wrapper responds to these environment variables:

    ALIEN_BASE_WRAPPER_QUIET

      If set to true, do not print the command before executing

SEE ALSO

    Alien::Base, Alien::Base

AUTHOR

    Graham Ollis <plicease@cpan.org>

COPYRIGHT AND LICENSE

    This software is copyright (c) 2017 by Graham Ollis.

    This is free software; you can redistribute it and/or modify it under
    the same terms as the Perl 5 programming language system itself.

