FermaT Transformation System

The FermaT Transformation System is a powerful industrial-strength program transformation system based on the WSL language.

FermaT has been used successfully in several major assembler to C migration projects: each project involved converting over half a million lines of hand-written assembler code to efficient and maintainable C code.

FermaT is available as free software under the GNU General Public License (GPL).

An example of a program transformation is Semantic Slicing. Consider the following WSL program:

total:= 0;i := 0;evens := 0;noevens := 0;odds := 0;noodds := 0;n := n0;WHILE i <= n DO evenflag := A [i] MOD 2; evenflag := 0; IF FALSE THEN evens := evens + A [i] ; noevens := noevens + 1 ELSE odds := odds + A [i] ; noodds := noodds + 1 FI; total := total + A [i] ; i := i + 1 OD;IF noevens <> 0 THEN meaneven := evens/noevens ELSE meaneven := 0 FI;IF noodds <> 0 THEN meanodd := odds/noodds ELSE meanodd := 0 FI;mean := total/(n+1);evendifference := ABS(meaneven - mean);odddifference := ABS(meanodd-mean)

Suppose we are interested in the final value of the variable evendifference. Save the program as a text file test-1.wsl and run the transformation:

dotrans test-1.wsl test-2.wsl Semantic_Slice data=evendifference

This generates the output file test-2.wsl:

evendifference := ABS(REDUCE("+", A [0..n0] ) / (n0 + 1))

See [http://www.cse.dmu.ac.uk/~mward/martin/papers/csmr2005-t.pdf this paper] for more information about semantic slicing.

[http://www.cse.dmu.ac.uk/~mward/fermat.html Download FermaT here]