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

David Beazley wrote:

> Oren Miller writes:
> > Using the latest CVS version:
> > 
> > If I have a char array defined like this:
> > 
> >   const char BeginString_FIX44[8] = "FIX.4.4";
> > 
> > The wrapper for this is generated correctly like so:
> > 
> > static PyObject *_wrap_BeginString_FIX44_get() {
> >      PyObject *pyobj;
> > 
> >      pyobj = SWIG_FromCharArray(FIX::BeginString_FIX44, 8);
> >      return pyobj;
> > }
> > 
> > However, if it is defined like so:
> > 
> >   const char BeginString_FIX44[] = "FIX.4.4";
> > 
> > This gets generated:
> > 
> > static PyObject *_wrap_BeginString_FIX44_get() {
> >      PyObject *pyobj;
> > 
> >      pyobj = SWIG_FromCharArray(FIX::BeginString_FIX44, );
> >      return pyobj;
> > }
> > 
> > As you can see the size is missing which of course results in 
> > compilation errors.  It would seem to me in this case Swig should count 
> > up the characters in the string and place the value as the second 
> > parameter to FromCharArray.  I'd be happy to try to create a patch but 
> > am not familiar with the source and would need someone to point me to 
> > the module where this generation occurs.  Thanks.
> > 
>
> 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.


> -- Dave
>
>
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>  

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