Topic: Upgrading to 2.24 from 2.13

I have just installed version 2.24 over the top of version 2.13. It all seemed to go well, but on trying to run a program which has run without problems on the old system, it starts, but then hangs up with no indication of what has happened.

It is straight forward Fortran code and is a series of lengthy numerical calculations. There is a main segment and three subroutines. The program builds and launches without indicating any compilation errors, so have I missed something in the installation process.

I have performed the cleaning process as required.

Is the new Fortran 95 compiler less tollerant than the older Fortran 77 compiler. Looking at one of the subroutines, which I have used for years, I see there are several Arithmetic IF statements. I know these are supossed to be obsolete in Fortran 95, if this is the problem, then why is there no compilation error being indicated.

Has anyone any ideas please?

David Clarke.

2 Reply by davidb (edited by davidb 2015-09-25 17:42:52)

Re: Upgrading to 2.24 from 2.13

I don't think this is because of your "over the top" install. I have always done that and not had any real problems.

This sounds like there is a bug in your program that is being exposed by the newer version of gfortran that is part of Simply Fortran.

I would try running with debug and all diagnostics turned on so you can see the line where the error occurs.
You could also try a different compiler that offers run-time undefined variable checking (which gfortran doesn't do) which will really help to find any problems in the code.

--
David
  • jeff
  • Administrator
  • Offline

Re: Upgrading to 2.24 from 2.13

David is probably correct in his diagnosis.   Without seeing the code, I can't make any real guess as to why the program hangs.  The compiler in 2.24 versus 2.13 is incrementally improved, so I doubt that the problem is a compiler incompatibility.  The compiler does fully support the Fortran 77 standard.  Possibly you had been lucky with the earlier compiler.

As David suggested, try enabling runtime diagnostics from the Fortran tab in Project Options, Clean, and re-Build your project.  It might reveal some issues in your code.

If you'd like me to have a look at the problem, you can, of course, email me the offending Fortran code at support@approximatrix.com.  That way I might be able to narrow down the issue.

Jeff Armstrong
Approximatrix, LLC

Re: Upgrading to 2.24 from 2.13

I am pleased to tell you that my problem is now resolved. I revised the offending Subroutine, taking care to observe the modern rules concerning IF statements and not using the old fashioned Arthmetic IF. Everything then worked as before when using Version 2.13. I took the time to insert Comments in between pieces of code to describe what was happening, since I had forgotten and I do not want to have to figure it out again.

It would be helpfull to be able to sent the results on Console Pane directly to the printer.

The original subroutine was written for a Ferranti Pegasus computer in Autocode about half a century ago. Incidently the Ferranti Pegasus had valves (vaccuum tubes) in it. The code was rewritten in Fortran 4 for an ICL 1904 main frame. It had a short life in Quick Basic during DOS days, but has been lying dormant now for about 10 years. I found Simply Fortran last year and now everything is up and running once more.

Many thanks to DavidB and Jeff for their help and encouragement.

David Clarke