[PyKDE] exception handling problems with sip

[Jacob M. Burbach]

On Thursday 13 April 2006 5:41, Jacob M. Burbach wrote:
> On Tuesday 11 April 2006 9:29, Jacob M. Burbach wrote:
> > On Monday 10 April 2006 4:50, Jacob M. Burbach wrote:
> > > Was hesitant to post to list about this being unsure if its actually a
> > > problem with sip(the generated code look fine). But after a series of
> > > tests the problem only arises when using sip so...
> > >
> > > I'm wrapping a C++ library which makes heavy use of exceptions for its
> > > error handling, theres a base Exception class which more specific
> > > exceptions are derived from.
> > >
> > > Everything seemed to be working fine, until building the extension
> > > module without debug symbols. Without debug the exceptions were no
> > > longer caught and cause the program to abort. For some reason, when
> > > built without debug, all exceptions are then received ONLY as the base
> > > Exception class.
> > >
> > > try {
> > > 	throw SpecificException();
> > > }
> > > catch (SpecificException& sipExceptionRef) {
> > > 	// Works as expected when built with debug symbols.
> > > 	// NOT caught when built without debug symbols.
> > > 	...
> > > }
> > >
> > > I am really confused about what is going on here...
> > >
> > > I've put together a small test package containing a tiny C++ library
> > > that throws exceptions, along with the sip files to build a wrapper for
> > > it. I also included handwritten python wrapper to show that the problem
> > > is only when using sip. See the README in the package for more
> > > details...
> > >
> > > http://home.cfl.rr.com/filedump/sip_exception_testcase.tar.bz2
> > >
> > > using sip 4.4.1 and Python 2.4
> >
> > Am I really the only one to come across this problem?
> >
> > Tested: gcc-3.3 with sip-4.4.1 and python2.3
> > Tested: gcc-3.4.5 with (sip-4.4.1|sip-snapshot) and python2.4
> >
> > Same behaviour with all.
> >
> > If anyone would be willing to try the test case out and report back, or
> > can think of anything that might cause this, or anything I can try to fix
> > this I would greatly appreciate it.
>
> Well if I weren't blind I probably would have noticed that the only real
> difference in the compiler output between debug/ndebug was the addition of
> `-Wl,--version-script=Foo.exp'.
>
> After removing this bit from the Makefile the problem does go away. So I
> guess now the question is, what exactly is this flag for, and why does it
> break the module?
>

Well, if for nothing else than to document the solution. If you run into this 
problem, setting `export_all' to true in your configuration object before 
creating the makefiles will disable the problem flag.

cfg = sipconfig.Configuration()
cfg.export_all = True
SIPModuleMakefile(configuration = cfg, ...)

After browsing through `sipconfig.py' it seems this flag is for deciding which 
symbols to export, to help keep libs smaller? I wonder though if this flag 
should be enabled by default in light of these nasty side affects?