dlr - Dynamic Library Redux

Project home: http://github.com/TheMarkitecht/dlr

Legal stuff: see below.

Introduction:

dlr is an extension for Jim Tcl, the small-footprint Tcl interpreter.

dlr may be easily pronounced as "dealer". It makes deals between Jim and native code.

dlr binds your Jim scripts to libffi (Foreign Function Interface). It lets your Jim scripts dynamically call a shared object library (.so file) of your choosing, without writing any C/C++ code if you don't want to.

Features of This Version:

Concise syntax for declaring native functions and structs.
Supports struct types. But not nested structs, yet.
Can automatically extract actual size and offset information for each struct member, as built by the current host's compiler (works with gcc or clang).
Supports calling only one direction: from script to native code.
Supports GObject Introspection for calling GTK+ 3 GUI toolkit, and other libraries built on GNOME GObject. See gizmo project
Lightweight, small footprint. No dependencies other than Jim and libffi.
Creates the thinnest possible C wrapper around libffi, for maximum simplicity, and future portability. The surrounding features are implemented in a script package.
Extensible packing/unpacking framework in the script package. That supports fast dispatch, and selective implementation of certain type conversions entirely in C, if needed for your app.
Automatically generated code is kept separate, in the auto/ directory, while handwritten binding scripts are kept in the script/ directory.
Ultra-simple build process. Native source for dlr is just one .c file.
Works with Jim's package require command.
Automatically adapts to various machine word sizes and endianness.
Designed for Jim 0.79 on GNU/Linux for amd64 architecture (includes Intel CPU's).
Tested on Debian 10.0 with libffi6-3.2.1-9.
Might work well on ARM too. It has passed tests there before. Drop me a line if you've tried it!

Requirements:

Jim 0.79 or later
libffi (tested with libffi6-3.2.1-9)
gcc (tested with gcc 8.3.0)

Building:

See build script.

Future Direction:

Improve UTF8 support. Currently UTF8 is treated as ASCII.
Expand the packing/unpacking framework in the script package, for unions etc.
Test on ARM embedded systems.
Support callbacks from native code to script.
Supply a binding for a practical GUI toolkit, likely GTK+3. << this is in progress; see gizmo project
Speed improvements?
Maybe let the script package generate C code to speed up your call, after your call is known to work well.

Legal stuff:

"dlr" - Dynamic Library Redux
Copyright 2020 Mark Hubbard, a.k.a. "TheMarkitecht"
http://www.TheMarkitecht.com

Project home:  http://github.com/TheMarkitecht/dlr
dlr is an extension for Jim Tcl (http://jim.tcl.tk/)
dlr may be easily pronounced as "dealer".

This file is part of dlr.

dlr is free software: you can redistribute it and/or modify
it under the terms of the GNU Lesser General Public License as published by
the Free Software Foundation, either version 3 of the License, or
(at your option) any later version.

dlr is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
GNU Lesser General Public License for more details.

You should have received a copy of the GNU Lesser General Public License
along with dlr.  If not, see <https://www.gnu.org/licenses/>.

See COPYING.LESSER and COPYING.

Contact:

Send donations, praise, curses, and the occasional question to: Mark-ate-TheMarkitecht-dote-com

Final Word:

I hope you enjoy this software. If you enhance it, port it to another environment, or just use it in your project etc., by all means let me know.

- TheMarkitecht