Applications of symbolic evaluation

Symbolic evaluation is a program analysis method that represents a program's computations and domain by symbolic expressions. In this paper a general functional model of a program is first presented. Then, three related methods of symbolic evaluation, which create this functional description from a program, are described: path-dependent symbolic evaluation provides a representation of a specified path; dynamic symbolic evaluation, which is more restrictive but less costly than path-dependent symbolic evaluation, is a data-dependent method; and global symbolic evaluation, which is the most general yet most costly method, captures the functional behavior of an entire program when successful. All three methods have been implemented in experimental systems. Some of the major implementation concerns, which include effectively representing loops, determining path feasibility, dealing with compound data structures, and handling routine invocations, are explained. The remainder of the paper surveys the range of applications to which symbolic evaluation techniques are being applied. The current and potential role of symbolic evaluation in verification, testing, debugging, optimization, and software development is explored.