Wednesday, 29 July 2009

Delphi Generics

Generics was or is one of the flagship features of Delphi 2009. Probably up there with unicode. Unfortunately, I don’t think the time was been put into the feature that it deserves. It feels like a badly implemented third party component. There doesn’t seem to be much in the way of communication with the ide. Code completion doesn’t work with generics. Same with class completion. Why not? Refactoring falls over as well.

This was all annoying, but we could almost live with it. Unfortunately we’ve now got a problem, which means we can’t use generics at all. Most of our automated testing is done with Automated QA’s Test Complete. Since we’ve moved to Delphi 2009, we’ve had a major problem, in that the debug information from our Delphi application was not being read properly from Test Complete 7. Here’s my question about it on Stack Overflow. Automated were baffled. We tried writing small test applications, but we couldn’t reproduce the problem. There was something about our application, Test Complete didn’t like. After months of investigation, we finally came to the conclusion that generics was the problem. Luckily, we had actually refactored some of our code to use generics, so it was easy to go back to the previous version. And hey presto, Test Complete is now totally happy.

Automated are now looking at it. I wonder if it’s a Test Complete problem, or is it generics messing up the debug information in the executable?

1 comment:

Eric said...

Generics in D2009 can still end up messing up the compiler codegen (even after SP3), chances are it can mess up your debug information too, or that the issue that are caught are actual ones (not incorrect code from your part, but incorrect code generation by the compiler)