[4diac-dev] Planned IEC 61499 type hash changes in Eclipse 4diac 3.5

[Alois Zoitl <alois.zoitl@xxxxxx>]

Hi all,

I would like to give you an early heads-up about a planned change to the IEC 61499 type hash algorithm in Eclipse 4diac IDE.

During our work on IEC 61499 XSDs and investigations into recently discovered bugs, we identified several issues in the current algorithm used to detect functional or structural mismatches between 4diac IDE and 4diac FORTE.

Addressing these issues requires backward-incompatible changes to the resulting hash values. To avoid multiple incompatible updates, we plan to collect all known and foreseeable hash-related changes and introduce them together with an algorithm version bump in Eclipse 4diac 3.5.

What does this mean for users?

• No action is required at this time.
• With 4diac IDE 3.5, hash values may change even for unmodified IEC 61499 types, depending on the features they use.
• FB types will therefore need to be re-exported to ensure consistency between 4diac IDE and 4diac FORTE.

We are also introducing regression tests to prevent unintended hash changes before the planned update.

We have created a planning issue to coordinate the changes and keep everyone informed: https://github.com/eclipse-4diac/4diac-ide/issues/3175

Please feel free to comment on the issue if you have questions, concerns, or additional cases we should consider. You can also subscribe to the issue to follow further developments.

Cheers,
The Eclipse 4diac Team