swig generated code can not be compiled when option -nortti is used and %feature("director") is enabled for a c++ class

[Andreas Oberritter]

Binary package hint: swig1.3

Package: 1.3.33-2ubuntu1 (Ubuntu hardy)
Target language: Python

Swig provides the option -nortti to be used in conjunction with C++ code, which is compiled with -fno-rtti. This takes effect only if "directors" are used. It defines SWIG_DIRECTOR_NORTTI.

From the swig source code (Source/Modules/python.cxx):

#ifdef SWIG_DIRECTOR_NORTTI
/*
   When we don't use the native C++ RTTI, we implement a minimal one
   only for Directors.
*/

[...]

# define SWIG_DIRECTOR_CAST(Arg) Swig::get_rtdir(static_cast<void*>(Arg))
# define SWIG_DIRECTOR_RGTR(Arg1, Arg2) Swig::set_rtdir(static_cast<void*>(Arg1), Arg2)

#else

# define SWIG_DIRECTOR_CAST(Arg) dynamic_cast<Swig::Director*>(Arg)
# define SWIG_DIRECTOR_RGTR(Arg1, Arg2)

#endif /* SWIG_DIRECTOR_NORTTI */

The reason is that dynamic_cast<> must not be used with -fno-rtti. However, swig doesn't use the preprocessor macro defined above in one case, namely in Language::classDirectorDisown() (file: Source/Modules/lang.cxx).

You can work around this problem by applying the attached patch to swig, probably breaking other target languages.

[Daniel T Chen (crimsun)]

Is this symptom still reproducible in 8.10 or 9.04?

[Pedro Villavicencio (pedro)]

We are closing this bug report because it lacks the information we need to investigate the problem, as described in the previous comments. Please reopen it if you can give us the missing information, and don't hesitate to submit bug reports in the future. To reopen the bug report you can click on the current status, under the Status column, and change the Status back to New. Thanks again!.

[William Fulton (william-fultondesigns)]

This was reported upstream: https://sourceforge.net/tracker/index.php?func=detail&aid=2952374&group_id=1645&atid=101645. Fix applied for swig-2.0.0.