Dagger: Cycles between @Module.subcomponents and @Subcomponent.modules

[ZacSweers]

Trying to incorporate the new android tooling in the RC, get this now:

An annotation processor threw an uncaught exception.
Consult the following stack trace for details.
java.lang.StackOverflowError
        at java.security.AccessController.doPrivileged(Native Method)
        at sun.reflect.annotation.AnnotationParser.annotationForMap(AnnotationParser.java:303)
        at com.sun.tools.javac.model.AnnotationProxyMaker.generateAnnotation(AnnotationProxyMaker.java:89)
        at com.sun.tools.javac.model.AnnotationProxyMaker.generateAnnotation(AnnotationProxyMaker.java:81)
        at com.sun.tools.javac.code.AnnoConstruct.getAnnotation(AnnoConstruct.java:185)
        at dagger.internal.codegen.MapKeys.unwrapValue(MapKeys.java:76)
        at dagger.internal.codegen.Key$Factory.mapKeyType(Key.java:495)
        at dagger.internal.codegen.Key$Factory.bindingMethodKeyType(Key.java:468)
        at dagger.internal.codegen.Key$Factory.forBindingMethod(Key.java:421)
        at dagger.internal.codegen.Key$Factory.forBindsMethod(Key.java:385)
        at dagger.internal.codegen.DelegateDeclaration$Factory.create(DelegateDeclaration.java:73)
        at dagger.internal.codegen.ModuleDescriptor$Factory.create(ModuleDescriptor.java:175)
        at dagger.internal.codegen.ComponentDescriptor$Factory.create(ComponentDescriptor.java:502)
        at dagger.internal.codegen.ComponentDescriptor$Factory.create(ComponentDescriptor.java:519)
        at 
.......

I can't share a reproducible case at the moment, but some context around what I was doing:

• Basically following the website documentation for setting up activity injection, and creating my own version of fragment injection (basically the same thing, but not for injecting fragments but something similar)

[JonathanMerritt]

Considering that you're using a customized setup, and the error seems to imply it is caused by it.

I would assume no one will be able to help you without at least posting the custom code you're using.

Was this same setup working on rc1?

[ZacSweers]

It's also an RC build, where the previous one's android artifact was hosed, so I don't think it hurts to surface feedback sooner rather than later in case it looks relevant to recent changes.

I can't share the case here, publicly, but I've also contacted @ronshapiro separately about adding someone onto the private project to peek at the code.

[ronshapiro]

Definitely appreciate you filing the issue. From the looks of it so far, this appears to be either a javac issue, or a previous bug in the dagger compiler that was exposed now. @hzsweers can you try to peel off a few layers and see if we can get something close to a reproducible bug, even if you don't know what's going on?

Here are a few guesses:

• the code is failing when analyzing a @Binds method. is your @MapKey in a different compilation unit, and if so, does it have at least @Retention(CLASS) or RUNTIME?
• Can you post a sanitzed version of your @MapKey? Is it possible it's malformed?

If you patch the Dagger compiler, you could pretty easily print out the method that this is failing on and that will give a lot more clues (unless you already know which one it is).

Are you seeing this error 100% of the time? I presume this is with your Buck setup?

It's not super clear to me where this is actually stack-overflowing. Do you see the repetition in part of the stack trace you didn't post?

[ZacSweers]

Will do on the points. To touch on the others -
this is actually just vanilla gradle, happens with error prone on and off. Single module

This is the line that overflows, sorry I cut it off a bit too soon:

at dagger.internal.codegen.ComponentDescriptor$Factory.create(ComponentDescriptor.java:519)

[steffandroid]

I've experienced this as well. Here's an example project which reproduces the issue:

https://github.com/steffandroid/DaggerStackOverflowExample

[ronshapiro]

Thanks for posting that example. It seems that you have a cycle: MainModule has subcomponents = MainComponent.class and MainComponent has modules = MainModule.class.

[steffandroid]

D'oh! Thanks.

[ZacSweers]

Yep same issue for me!

[ronshapiro]

Reopening this so that we can make sure to have better reporting around cycles like this