A compiler takes source, breaks it into tokens, does further analysis, and produces a tree, and a symbol table. These are further processed into actual executable.
If you preserve all of the source code, including comments and whitespaces, you can work backwards from the syntactic tree and symbol tables to recreate the original source, losslessly. Once this step is up and running, it should be possible to directly edit the symbol table (as long as duplicates are forbidden), and make a refactoring compiler.
The next logical step is to then allow for the refactoring of code segments into new subroutines, etc. A completed Refactoring Compiler should be able to save all the information necessary for recreating the source of a program, in the executable file.
