We suggest an approach to the development of software testing and debugging 
automation tools based on precise program behavior models. The program behavior 
model is defined as a set of events (event trace) with two binary relations over 
events -- precedence and inclusion, and represents the temporal relationship 
between actions. A language for the computations over event traces is developed 
that provides a basis for assertion checking, debugging queries, execution 
profiles, and performance measurements.

The approach is nondestructive, since assertion texts are separated from the 
target program source code and can be maintained independently. Assertions can 
both capture  the dynamic properties of a particular target program and can 
formalize the general knowledge of typical bugs and debugging strategies. An 
event grammar provides a sound basis for assertion language implementation via 
target program automatic instrumentation. Event grammars may be designed for 
sequential as well as for parallel programs, and the suggested approach can be 
adjusted to a variety of programming languages.

The experience with assertion checker prototypes based on event traces and 
implementation issues are briefly discussed.
 
Keywords. 

Program behavior models, events, event grammars, software testing and debugging 
automation