Test templates and a test template framework are introduced as useful concepts in specification-based testing The framework can be defined using any model-based specification notation and used to derive tests from model-based specificationsin this paper, it is demonstrated using the Z notation. The framework formally defines test data sets and their relation to the operations in a specification and to other test data sets, providing structure to the testing process. Flexibility is preserved, so that many testing strategies can be used. Important application areas of the framework are discussed, including refinement of test data, regression testing, and test oracles.

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Precision and scz: ability are two desirable, yet often conflicting, features of data-flow analyses. This paper reports on a case study of the modification., ide-effects problem for C in the presence of pointers from the pers 9ective of contrasting the flow and context sensitivity of the solul ion procedure with respect to precision and scatability. The res~ Its show that the cost of precision of flow-and context-sensitive analysis is not always prohibitive, and that the precision of flow-a= d context-insensitive analysis is substantially better than worst-ca~ e estimates and can be sufficient for certain applications. Program characteristics that affect the performance of dataflow analysis are ~dentified.

Precision and scalability are two desirable, yet often conflicting, features of data-flow analyses. This paper reports on a case study of the modification---ide-effects problem for C in the presence of pointers from the perspective of contrasting the flow and context sensitivity of the solution procedure with respect to precision and scalability. The results show that the cost of precision of flow- and context-sensitive analysis is not always prohibitive, and that the precision of flow- and context-insensitive analysis is substantially better than worst-case estimates and can be sufficient for certain applications. Program characteristics that affect the performance of data-flow analysis are identified.

The first interprocedural modification side-effects analysis for C (MOD C ) that obtains better than worst-case precision on programs with general-purpose pointer usage is presented with empirical results. The analysis consists of an algorithm schema corresponding to a family of MOD C algorithms with two independent phases: one for determining pointer-induced aliases and a subsequent one for propagating interprocedural side effects. These MOD C algorithms are parameterized by the aliasing method used. The empirical results compare the performance of two dissimilar MOD C algorithms: MOD C (FSAlias) uses a flow-sensitive, calling-context-sensitive interprocedural alias analysis; MOD C (FIAlias) uses a flow-insensitive, calling-context-insensitive alias analysis which is much faster, but less accurate. These two algorithms were profiled on 45 programs ranging in size from 250 to 30,000 lines of C code, and the results demonstrate dramatically the possible costprecision trade-offs. This first comparative implementation of MOD C analyses offers insight into the differences between flow-/context-sensitive and flow-/context-insensitive analyses. The analysis cost versus precision trade-offs in side-effect information obtained are reported. The results show surprisingly that the precision of flow-sensitive side-effect analysis is not always prohibitive in cost, and that the precision of flow-insensitive analysis is substantially better than worst-case estimates and seems sufficient for certain applications. On average MOD C (FSAlias) for procedures and calls is in the range of 20% more precise than MOD C (FIAlias); however, the performance was found to be at least an order of magnitude slower than MOD C (FIAlias).