David Hedley

A Measure of Control Flow Complexity in Program Text

This paper discusses the need for measures of complexity and unstructuredness of programs. A simple language independent concept is put forward as a measure of control flow complexity in program text and is then developed for use as a measure of unstructuredness. The proposed metric is compared with other metrics, the most notable of which is the cyclomatic complexity measure. Some experience with automatic tools for obtaining these metrics is reported.

Experience with Path Analysis and Testing of Programs

There are a number of practical difficulties in performing a path testing strategy for computer programs. One problem is in deciding which paths, out of a possible infinity, to use as test cases. A hierarchy of structural test metrics is suggested to direct the choide and to monitor the coverge of test paths. Another problem is that many of the chosen paths may be infeasible in the sense that no test data can ever execute them. Experience with the use of allegations to circumvent this problem and prevent the static generation of many infeasible paths is reported.

On program analysis

Interpretation and Static Analysis David Schmidt Kansas State University Four parts:

Quantifying the test effectiveness of Algol 68 programs

In this paper we describe how a software testbed is used to determine the quality of testing of Algol 68 programs. The system monitors the execution of an Algol 68 program and obtains a run-time execution history. This history is then compared with the results of a static analysis and three levels of testing are calculated. The third level is an extension to Algol 68 of a method originally devised for analysing Fortran IV programs. The system has been used extensively in the coordination stage of the NAG Algol 68 numerical algorithms library and we quote some results obtained from an analysis of stringent tests on these library routines.

Static dataflow-aided weak mutation analysis (SDAWM)

Abstract A new static analysis methodology (known as static dataflow-aided weak mutation (SDAWM) intended for use as a preprocessor to a variable mutation system is described. The procedure is based around a marriage of existing static dataflow analysis concepts and weak mutation ideas. The (dataflow) path expression of a variable is analysed to assess what the impact of strong mutation would be if it was performed. A methodology is presented that pre-empts strong or weak mutation by removing a significant number of variable mutants statically and without actually creating them, thus saving processor time later.