Graham Ollis 🔥🐉

NAME

FFI::Platypus::Lang::Pascal - Documentation and tools for using Platypus with the Free Pascal programming language

SYNOPSIS

Free Pascal:

 { compile and link with: fpc mylib.pas }
 
 Library MyLib;
 
 Function Add(A: Integer; B: Integer): Integer; Cdecl;
 Begin
   Add := A + B;
 End;
 
 Exports
   Add;
 
 End.

Perl:

 use FFI::Platypus;
 
 my $ffi = FFI::Platypus->new;
 $ffi->lang('Pascal');
 $ffi->lib('./libmylib.so');
 
 $ffi->attach(
   Add => ['Integer','Integer'] => 'Integer'
 );
 
 print Add(1,2), "\n";

DESCRIPTION

This modules provides native types and demangling for the Free Pascal Programming language when used with FFI::Platypus.

This module provides these types (case sensitive):

Byte
ShortInt
SmallInt
Word
Integer

This is an alias for SmallInt (which is appropriate for Free Pascal's default mode)

Cardinal
LongInt
LongWord
Int64
QWord
Boolean
ByteBool
WordBool
LongBool
Single
Double

The following types are not (yet) supported:

Extended
Comp
Currency
ShortString

This module also has some support for demangled functions and overloading, if you are using a dynamic library constructed from units via ppumove.

You may also use Module::Build::FFI::Pascal to bundle Free Pascal code with your distribution.

CAVEATS

I've been experimenting with Free Pascal 2.6.0 while working on this module.

name mangling

If you compile one or more Pascal Units and link them using ppumove, they symbols in the resulting dynamic library will include mangled Pascal names. This module has at least some support for such names.

For example, suppose you had this Pascal Unit:

 Unit Add;
 
 Interface
 
 Function Add( A: SmallInt; B: SmallInt) : SmallInt; Cdecl;
 Function Add( A: Real;    B: Real)      : Real; Cdecl;
 
 Implementation
 
 Function Add( A: SmallInt; B: SmallInt) : SmallInt; Cdecl;
 Begin
   Add := A + B;
 End;
 
 Function Add( A: real; B: real) : real; Cdecl;
 Begin
   Add := A + B;
 End;
 
 End.

On Linux, you could compile and link this into a shared object with these commands:

 fpc add.pas
 gcc -o add.so -shared add.o

And you could then use it from Perl:

 use FFI::Platypus;
 
 my $ffi = FFI::Platypus->new;
 $ffi->lang('Pascal');
 $ffi->lib('./add.so');
 
 $ffi->attach(
   ['Add.Add(SmallInt,SmallInt):SmallInt' => 'Add'] => ['SmallInt','SmallInt'] => 'SmallInt'
 );
 
 print Add(1,2), "\n";

When attaching the function you have to specify the argument and return types because the Add function is overloaded and is ambiguous without it. If there were just one Add function, then you could attach it like this:

 $ffi->attach('Add' => ['SmallInt','SmallInt'] => 'SmallInt');

The downside to using a shared library constructed from Pascal Units in this way is that the resulting dynamic library does not include the Pascal standard library so very simple capabilities such as IO and ShortString are not available. It is recommended instead to use a Pascal Library (possibly linked with one or more Pascal Units), as inthe "SYNOPSIS" at the top.

METHODS

Generally you will not use this class directly, instead interacting with the FFI::Platypus instance. However, the public methods used by Platypus are documented here.

native_type_map

 my $hashref = FFI::Platypus::Lang::Pascal->native_type_map;

This returns a hash reference containing the native aliases for the Free Pascal programming languages. That is the keys are native C++ types and the values are libffi native types.

Types are in camel case. For example use ShortInt, not Shortint or SHORTINT.

mangler

 my $mangler = FFI::Platypus::Lang::Pascal->mangler($ffi->libs);
 # prints ADD_ADD$SMALLINT$SMALLINT$$SMALLINT
 print $mangler->("add(smallint,smallint):smallint");

Returns a subroutine reference that will "mangle" C++ names.

EXAMPLES

See the above "SYNOPSIS" or the examples directory that came with this distribution.

SUPPORT

If something does not work as advertised, or the way that you think it should, or if you have a feature request, please open an issue on this project's GitHub issue tracker:

https://github.com/Perl5-FFI/FFI-Platypus-Lang-Pascal/issues

This project's GitHub issue tracker listed above is not Write-Only. If you want to contribute then feel free to browse through the existing issues and see if there is something you feel you might be good at and take a whack at the problem. I frequently open issues myself that I hope will be accomplished by someone in the future but do not have time to immediately implement myself.

Another good area to help out in is documentation. I try to make sure that there is good document coverage, that is there should be documentation describing all the public features and warnings about common pitfalls, but an outsider's or alternate view point on such things would be welcome; if you see something confusing or lacks sufficient detail I encourage documentation only pull requests to improve things.

CONTRIBUTING

If you have implemented a new feature or fixed a bug then you may make a pull reequest on this project's GitHub repository:

https://github.com/Perl5-FFI/FFI-Platypus-Lang-Pascal/pulls

SEE ALSO

FFI::Platypus

The Core Platypus documentation.

Module::Build::FFI::Pascal

Bundle Free Pascal with your FFI / Perl extension.

AUTHOR

Graham Ollis <plicease@cpan.org>

COPYRIGHT AND LICENSE

This software is copyright (c) 2015 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.