The software engineering tool used is fpt.
fpt reads a Fortran program in a similar way to a compiler. It builds an internal representation of the code and carries out a detailed static semantic analysis, identifying all of the keywords, variables and control constructs.
fpt differs from a compiler in that it can read all of the subroutines and functions which make up a program in a single pass, and can correlate information between them. It can also re-write the code and make systematic modifications to it. This facility is used in this project to engineer the emulation of real arithmetic, and to insert the run-time trace statements.
fpt is described in detail at the SimCon web site. It is available for download from the site, but the tools which support emulation of real arithmetic are currently experimental and are not present in the published version. Please contact the author if you wish to use them.