Begin forwarded message:
> From: Joseph Reichman <reichman...@gmail.com> > Date: April 23, 2019 at 10:48:07 AM EDT > To: Martin Ward <mar...@gkc.org.uk> > Subject: Re: Sysadata symbol and literal cross reference record type x’44’ > re-post from IBMMAIN > > I work for the IRS and the tax processing code is HUGE and OLD Assembler > > I’m on a team doing the documentation in the hope of one day having it in > Java > > I am in charge of tracing the code obviously self modified code has issues > Normally a breakpoint on self modified code abends > However some one found code that was modified ( a CLC bytes 4 & 5 ) that > obviously didn’t blow up but the debugger when retrying the instruction with > a breakpoint used the originally 6 bytes of the CLC which produced different > results > If I could up from identify it would be helpful > Obviously I could write code when looking at the sysadata was looking maybe > the group has an idea > > Thanks > > > >>> On Apr 23, 2019, at 10:36 AM, Martin Ward <mar...@gkc.org.uk> wrote: >>> >>> On 22/04/19 22:38, Joseph Reichman wrote: >>> To be more clear this goes back to the original problem of tracing a >>> 14 cesct huge piece of code I am wondering if I can identify what >>> instructions are modified >> >> Software Migrations Ltd. (the company I work for) offers a migration >> service to convert assembler code into functionally equivalent, >> structured, efficient and maintainable C or COBOL code. >> The process is totally automated but custimisable for each project. >> >> Therefore we have to be able to detect and translate any >> self-modifying code in the listing, wherever possible. We have seen some >> quite dramatic improvements in performance when migrating assembler >> code which does a lot of instruction modification! >> >> (Note that the thoretical problem of determining whether a particular >> program is self-modifying or not is, like the Halting Problem, >> non-computable. But in practice, all examples of self-modifying code >> we have encountered can be detected and translated.) >> >> Let me know if you would like to pursue this option. >> >> -- >> Martin >> >> Dr Martin Ward | Email: mar...@gkc.org.uk | http://www.gkc.org.uk >> G.K.Chesterton site: http://www.gkc.org.uk/gkc | Erdos number: 4
