Re: [pygccxml-development] [ANN] Py++ based ctypes code generator

[Gustavo C. <gjc...@gm...>]

2009/1/20 Roman Yakovenko <rom...@gm...>

> Hello.
>
> I would like to announce a new code generator for ctypes package.
>
> The new code generator is integrated with Py++ package and reuse most
> of its infrastructure:
> * GCC-XML - generates an XML description of a C++ program from GCC's
> internal representation
> * pygccxml - powerful and simple Python package to work GCCXML generated
> file.
> * Py++ design, code and utilities
> * It was build with future ( ctypes-cpp ) functionality in mind.
> * It has cross-platform ( Windows XP and Linux Ubuntu 8.10 ) unit tests
>
> How it works:
>
> 1. Using pygccxml, the source files are parsed ( using pygccxml ) and
> in-memory description of the code is created
> 2. .dll, .map or .so file is parsed ( pygccxml ) and exported symbols
> list is created
> 3. Using decorated and undecorated names, mapping between declarations
> and exported symbols is created.
> 4. The exported symbols and the mapping are used to:
>   * define for what declarations the code should be generated
>   * find out function calling convention
> 5. The last step - the code is generated
>
> Supported functionality:
>
> * shared libraries, that were compiled using C or C++ compiler
> * free functions, including variable number of arguments
> * [global|member] [named|anonymous] variables
> * [named|anonymous|opaque|nested]  structures
> * enumerations
> * typedefs
>
> Examples:
>
>    Is it useful? - Yes. I created example, which generates code for
> GMP( http://gmplib.org/ ) library. The following link (
>
> http://pygccxml.svn.sourceforge.net/viewvc/pygccxml/pyplusplus_dev/examples/gmplib_dev/
> ) will take you to the example.
>    * dev - directory, which contains code generator source code
>    * pygmplib - directory, which contains generated code - Python
> package, which provides access to GMP lib functionality
>    * test.py - Python script - tester.
>
> Want to try?
>    Windows users:
>        http://sourceforge.net/project/showfiles.php?group_id=118209
> contains few packages
>        * ctypes code generator - stand alone executable, which
> generates code for a .dll file
>        * gccxml-setup - gccxml setup file
>    Linux users:
>        Sorry, no binaries :-(
>        * you need to check-out( http://gccxml.org/HTML/Download.html
> ) and build gccxml ( http://gccxml.org/HTML/Install.html )
>        * you need to check-out Py++ and pygccxml (
> http://sourceforge.net/svn/?group_id=118209 )
>        * wrap_library.py (
> http://pygccxml.svn.sourceforge.net/viewvc/pygccxml/pyplusplus_dev/scripts/
> ) is the script, which generates code for .so file.
>
> Your feedback is welcome.


This is potentially very useful!  Generated Python code can be shipped with
any project and is (almost) platform independent without need for
compilation; you just run Python code.

However I have to wonder how (if) do you support C++ calling conventions.
Things like:
   - How to pass the 'this' parameter to call methods;
   - Function/method overloading.

I have followed the path of C++ code generation precisely because of the
difficulty of calling C++ code via libffi, or else I would probably have
contributed to the gobject-introspection and pybank projects.  I thought
ctypes did not support C++?

Cheers,

-- 
Gustavo J. A. M. Carneiro
INESC Porto, Telecommunications and Multimedia Unit
"The universe is always one step beyond logic." -- Frank Herbert