The ‘Completeness’ of the pascal test suite

The British Standards Institution aided by the National Physical Laboratory (NPL) are setting up the framework for a national service which will validate Pascal compilers against the requirements of the ISO Standard for Pascal.1 The basis of this service is the Pascal Compiler Validation Suite,2 a large collection of test programs (produced jointly by NPL and the University of Tasmania) which were derived directly from the Standard, Naturally, the Suite must be as searching as possible, and Ideally all features of the language should be exercised by the Suite. This paper describes an investigation into the ‘completeness’ of the Suite; note that ‘completeness’ is not used in any formal sense throughout the paper. The investigation is carried out by passing the entire Suite through a model implementation of Pascal, the Standard Pascal Static Checker,3 to determine whether any parts of this implementation do not get exercised by the Suite. Further tests are then written to exercise these parts. A by‐product of this work is a tool which produces an execution profile for a Pascal program; this paper describes the function of the tool.