On 5/30/18 8:09 AM, DigitalDesigns wrote:
Seriously stupid bug here!
I had an enum an static this() { } (empty, forgot why I added it) one
module and an struct in another module that converted values from the
enum. I imported only that enum and guess what?!?! Cycle dependency!
removed the static this() { } and worked!
The cycle dependency checking code is far too ignorant.
It is ignorant. It only checks for the presence of static constructors,
not what they do. This is as designed -- there are too many ways for
dependencies to leak between modules that it's really really hard to
make it check real dependencies.
It just blindly
checks without any rationale. Someone said this was because phobos had a
bug in it so the cycles were checked, maybe it's time to address that
issue rather than breaking code arbitrarily?
I don't know what was said, but the cycle code was very broken
originally. A few years ago, I fixed it, and then it was re-broken by
accident, and I re-fixed it.
It should work properly now. But that has nothing to do with adding an
empty static ctor, it had to do with properly detecting cycles.
The cycle detection functions as designed. You can disable it via DRT
flags, but this means that there is no guarantee that they run in the
proper order. The compiler would have to build a much more sophisticated
dependency tree in order to do anything more clever, but I doubt it
would ever be able to be perfect in detecting which things truly depend
on one another.
-Steve
