fortran maintenance tools

Hi,

For the past 10 or so years I've been working on other people's
Fortran codes, mostly to parallelize and optimize. These codes evolve,
they're not created. That and the fact that they're in the 100k-200k
line size means they're too big for me to understand and I just hate
modifying them because I'm afraid of screwing things up. Needless to
say, I constantly have to do things like figure out where values come
from or will be used, rewrite a loop nest so it will pipeline on an
Itanium, put code around every subroutine call to collect performance
information, or pull out a large section of code from a ridiculously
large subroutine and turn it into its own subroutine. It's the usual
maintenance on large programs where performance is important. I do it
all the time, but I'd like help doing it faster. What I'd like is an
interactive tool that would help me with this. It would help me
understand such programs and help me make changes in a systematic
way. By systematic I mean it can check to make sure I haven't violated
certain assertions or, better yet, can make the changes for me. I want
something that's interactive and also has abilities found in a
compiler.

I haven't seen anything like this. There are tools that show call
graphs, will do pretty printing, and even some documentation, but I
haven't even found anything that will show data flow information, not
to mention something that can modify code.

So, I'm thinking of building something. I've built compiler tools
before so I have a certain amount of code already available. But this
is still anything but trivial. The question I have is would anyone
else be interested in it?

Matt

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