Re: bug while wrapping const char arrays without an explicitly defined size

David Beazley wrote:

> Marcelo Matus writes:
> > >Where is SWIG_FromCharArray() coming from?   I don't remember that
> > >function being part of the SWIG API (I sure didn't write it anyways).
> > >
> > >SWIG developers:   Is there some reason the normal PyObject API
> > >functions are not being used here???
> > >
> > >  
> > >
> > 
> > Most of the PyObject API functions don't check for NULL pointers, and
> > if you pass one, python crashes. Also, internally python uses
> > 'int' for size, which means if you have a very large binary string
> > python can't handle it.
> > 
> > The extra SWIG_XXX methods check for null when needed and
> > return you a plain pointer (not a python string) if the array size
> > is larger than INT_MAX.
> > 
>
> IMHO, both of these problems sound like issues that can be resolved
> using user-defined typemaps and are not necessary for SWIG's default
> behavior.
>
>  

probably the very large strings could have special typemaps,
but the checking of NULL should be there since is not uncommon
to pass or return a NULL value for char*.

In fact, the NULL check is in the 1.3.21, but is inside the typemaps, in
some cases, in other cases the check was missing.

The other thing I forgot, if you get a swig pointer, like

_012234_p_char

that you create using carrays (or other form), then in

 void test_case(char * in);

the old 1.3.21 passes you the string "_012234_p_char", and not
the pointer 0x01234.

all these little differences or features of C++/python/swig
can be added to the typemaps, or in the SWIG_XXX methods.
I like the later better since the code generated is shorter
and more consistent (you are sure the same checks are performed
in the in,out,varin,directorout,... typemaps where you use
the SWIG_XXX methods).

Marcelo

PS: Anyway, the reported problem was not related to the SWIG_XXX
methods, but to the fact that I added the 'char [ANY]' forms, but
I forgot to add the 'char []' form to the  typemaps.


> -- Dave
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>  

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