An Embedded Error Recovery and Debugging Mechanism for Scripting Language Extensions

In recent years, scripting languages such as Perl, Python, and Tcl have become popular development tools for the creation of sophisticated application software. One of the most useful features of these languages is their ability to easily interact with compiled languages such as C and C++. Although this mixed language approach has many benefits, one of the greatest drawbacks is the complexity of debugging that results from using interpreted and compiled code in the same application. In part, this is due to the fact that scripting language interpreters are unable to recover from catastrophic errors in compiled extension code. Moreover, traditional C/C++ debuggers do not provide a satisfactory degree of integration with interpreted languages. This paper describes an experimental system in which fatal extension errors such as segmentation faults, bus errors, and failed assertions are handled as scripting language exceptions. This system, which has been implemented as a general purpose shared library, requires no modifications to the target scripting language, introduces no performance penalty, and simplifies the debugging of mixed interpreted-compiled application software.