################################################################################
##
## $Revision: 32 $
## $Author: mhx $
## $Date: 2009/01/18 14:10:54 +0100 $
##
################################################################################
##
## Version 3.x, Copyright (C) 2004-2009, Marcus Holland-Moritz.
## Version 2.x, Copyright (C) 2001, Paul Marquess.
## Version 1.x, Copyright (C) 1999, Kenneth Albanowski.
##
## This program is free software; you can redistribute it and/or
## modify it under the same terms as Perl itself.
##
################################################################################
=provides
=dontwarn
NEED_function
NEED_function_GLOBAL
NEED_variable
NEED_variable_GLOBAL
DPPP_NAMESPACE
=implementation
=pod
=head1 NAME
ppport.h - Perl/Pollution/Portability version __VERSION__
=head1 SYNOPSIS
perl ppport.h [options] [source files]
Searches current directory for files if no [source files] are given
--help show short help
--version show version
--patch=file write one patch file with changes
--copy=suffix write changed copies with suffix
--diff=program use diff program and options
--compat-version=version provide compatibility with Perl version
--cplusplus accept C++ comments
--quiet don't output anything except fatal errors
--nodiag don't show diagnostics
--nohints don't show hints
--nochanges don't suggest changes
--nofilter don't filter input files
--strip strip all script and doc functionality from
ppport.h
--list-provided list provided API
--list-unsupported list unsupported API
--api-info=name show Perl API portability information
=head1 COMPATIBILITY
This version of F<ppport.h> is designed to support operation with Perl
installations back to __MIN_PERL__, and has been tested up to __MAX_PERL__.
=head1 OPTIONS
=head2 --help
Display a brief usage summary.
=head2 --version
Display the version of F<ppport.h>.
=head2 --patch=I<file>
If this option is given, a single patch file will be created if
any changes are suggested. This requires a working diff program
to be installed on your system.
=head2 --copy=I<suffix>
If this option is given, a copy of each file will be saved with
the given suffix that contains the suggested changes. This does
not require any external programs. Note that this does not
automagially add a dot between the original filename and the
suffix. If you want the dot, you have to include it in the option
argument.
If neither C<--patch> or C<--copy> are given, the default is to
simply print the diffs for each file. This requires either
C<Text::Diff> or a C<diff> program to be installed.
=head2 --diff=I<program>
Manually set the diff program and options to use. The default
is to use C<Text::Diff>, when installed, and output unified
context diffs.
=head2 --compat-version=I<version>
Tell F<ppport.h> to check for compatibility with the given
Perl version. The default is to check for compatibility with Perl
version __MIN_PERL__. You can use this option to reduce the output
of F<ppport.h> if you intend to be backward compatible only
down to a certain Perl version.
=head2 --cplusplus
Usually, F<ppport.h> will detect C++ style comments and
replace them with C style comments for portability reasons.
Using this option instructs F<ppport.h> to leave C++
comments untouched.
=head2 --quiet
Be quiet. Don't print anything except fatal errors.
=head2 --nodiag
Don't output any diagnostic messages. Only portability
alerts will be printed.
=head2 --nohints
Don't output any hints. Hints often contain useful portability
notes. Warnings will still be displayed.
=head2 --nochanges
Don't suggest any changes. Only give diagnostic output and hints
unless these are also deactivated.
=head2 --nofilter
Don't filter the list of input files. By default, files not looking
like source code (i.e. not *.xs, *.c, *.cc, *.cpp or *.h) are skipped.
=head2 --strip
Strip all script and documentation functionality from F<ppport.h>.
This reduces the size of F<ppport.h> dramatically and may be useful
if you want to include F<ppport.h> in smaller modules without
increasing their distribution size too much.
The stripped F<ppport.h> will have a C<--unstrip> option that allows
you to undo the stripping, but only if an appropriate C<Devel::PPPort>
module is installed.
=head2 --list-provided
Lists the API elements for which compatibility is provided by
F<ppport.h>. Also lists if it must be explicitly requested,
if it has dependencies, and if there are hints or warnings for it.
=head2 --list-unsupported
Lists the API elements that are known not to be supported by
F<ppport.h> and below which version of Perl they probably
won't be available or work.
=head2 --api-info=I<name>
Show portability information for API elements matching I<name>.
If I<name> is surrounded by slashes, it is interpreted as a regular
expression.
=head1 DESCRIPTION
In order for a Perl extension (XS) module to be as portable as possible
across differing versions of Perl itself, certain steps need to be taken.
=over 4
=item *
Including this header is the first major one. This alone will give you
access to a large part of the Perl API that hasn't been available in
earlier Perl releases. Use
perl ppport.h --list-provided
to see which API elements are provided by ppport.h.
=item *
You should avoid using deprecated parts of the API. For example, using
global Perl variables without the C<PL_> prefix is deprecated. Also,
some API functions used to have a C<perl_> prefix. Using this form is
also deprecated. You can safely use the supported API, as F<ppport.h>
will provide wrappers for older Perl versions.
=item *
If you use one of a few functions or variables that were not present in
earlier versions of Perl, and that can't be provided using a macro, you
have to explicitly request support for these functions by adding one or
more C<#define>s in your source code before the inclusion of F<ppport.h>.
These functions or variables will be marked C<explicit> in the list shown
by C<--list-provided>.
Depending on whether you module has a single or multiple files that
use such functions or variables, you want either C<static> or global
variants.
For a C<static> function or variable (used only in a single source
file), use:
#define NEED_function
#define NEED_variable
For a global function or variable (used in multiple source files),
use:
#define NEED_function_GLOBAL
#define NEED_variable_GLOBAL
Note that you mustn't have more than one global request for the
same function or variable in your project.
__EXPLICIT_API__
To avoid namespace conflicts, you can change the namespace of the
explicitly exported functions / variables using the C<DPPP_NAMESPACE>
macro. Just C<#define> the macro before including C<ppport.h>:
#define DPPP_NAMESPACE MyOwnNamespace_
#include "ppport.h"
The default namespace is C<DPPP_>.
=back
The good thing is that most of the above can be checked by running
F<ppport.h> on your source code. See the next section for
details.
=head1 EXAMPLES
To verify whether F<ppport.h> is needed for your module, whether you
should make any changes to your code, and whether any special defines
should be used, F<ppport.h> can be run as a Perl script to check your
source code. Simply say:
perl ppport.h
The result will usually be a list of patches suggesting changes
that should at least be acceptable, if not necessarily the most
efficient solution, or a fix for all possible problems.
If you know that your XS module uses features only available in
newer Perl releases, if you're aware that it uses C++ comments,
and if you want all suggestions as a single patch file, you could
use something like this:
perl ppport.h --compat-version=5.6.0 --cplusplus --patch=test.diff
If you only want your code to be scanned without any suggestions
for changes, use:
perl ppport.h --nochanges
You can specify a different C<diff> program or options, using
the C<--diff> option:
perl ppport.h --diff='diff -C 10'
This would output context diffs with 10 lines of context.
If you want to create patched copies of your files instead, use:
perl ppport.h --copy=.new
To display portability information for the C<newSVpvn> function,
use:
perl ppport.h --api-info=newSVpvn
Since the argument to C<--api-info> can be a regular expression,
you can use
perl ppport.h --api-info=/_nomg$/
to display portability information for all C<_nomg> functions or
perl ppport.h --api-info=/./
to display information for all known API elements.
=head1 BUGS
If this version of F<ppport.h> is causing failure during
the compilation of this module, please check if newer versions
of either this module or C<Devel::PPPort> are available on CPAN
before sending a bug report.
If F<ppport.h> was generated using the latest version of
C<Devel::PPPort> and is causing failure of this module, please
file a bug report using the CPAN Request Tracker at L<http://rt.cpan.org/>.
Please include the following information:
=over 4
=item 1.
The complete output from running "perl -V"
=item 2.
This file.
=item 3.
The name and version of the module you were trying to build.
=item 4.
A full log of the build that failed.
=item 5.
Any other information that you think could be relevant.
=back
For the latest version of this code, please get the C<Devel::PPPort>
module from CPAN.
=head1 COPYRIGHT
Version 3.x, Copyright (c) 2004-2009, Marcus Holland-Moritz.
Version 2.x, Copyright (C) 2001, Paul Marquess.
Version 1.x, Copyright (C) 1999, Kenneth Albanowski.
This program is free software; you can redistribute it and/or
modify it under the same terms as Perl itself.
=head1 SEE ALSO
See L<Devel::PPPort>.
=cut