Re: [pygccxml-development] Py++ typedef handling

[Roman Y. <rom...@gm...>]

On Thu, Apr 23, 2009 at 8:01 PM, Patrick Hartling
<pat...@pr...> wrote:
> I have asked a couple of questions about typedef handling in the past, and I
> have yet another one: is there anything that I can do to force Py++ to use
> the typedefs from the original code in function default argument values and
> in instance method return types?

I guess, it is possible to attach "pretty name" to a type and use it
for code generation, but this is a huge change.

> What I see is that the typedef gets used in
> some places but not others. I haven't identified a pattern to this yet, but
> I am sure that there is one.

Yes: http://pygccxml.svn.sourceforge.net/viewvc/pygccxml/pyplusplus_dev/pyplusplus/decl_wrappers/decl_wrapper.py?revision=1664&view=markup

Take a look on "_get_alias" method.

> I have attached code that demonstrates the behavior that I see. test.cpp was
> generated on Windows using Py++ 1.0 and GCC-XML (emulating Visual C++ 9.0)
> built from its CVS repository as of April 21, 2009. I have added comments to
> the generated test.cpp where I see unexpected behavior. From looking at the
> output generated by GCC-XML, I think I understand how the typedef
> information used in template parameters gets lost, and that is unfortunate.
> Maybe there is some room to improve GCC-XML in this area.

It is very difficult. A year or two ago I tried to add something
similar to GCCXML ad got lost in GCC code. May be you will have more
luck.

> In case it matters, the use of 64-bit integers in the example is deliberate.
> Our code uses 64-bit types, and we use typedefs to mask the variation in the
> type declaration depending on operating system and bit width of the binary
> output. 64-bit integers are not the only type that has caused us problems,
> but this is the one that crops up most consistently.

You can do few tricks, before Py++ starts working:
* rename classes and types
* construct new types and typedefs

It is not a nice way. If your code has some coding convention or other
rules you can rely on, it should not be too difficult.

Take a look on http://pygccxml.svn.sourceforge.net/viewvc/pygccxml/pyplusplus_dev/examples/pyboost_dev/dev/date_time/generate_code.py?revision=1428&view=markup
file.
It contains code that does exactly this.

Let me know if you need more help.

-- 
Roman Yakovenko
C++ Python language binding
http://www.language-binding.net/