Hi everyone 👋 😄 . New to meta-programming and wanted to make sure if this is the best resource to learn about KSP? Thank you!

Hi, I created a simple processor and a JVM library module that uses it. But when I try to apply it to either an Android library or Android application I get gradle configuration errors. Is there any Android examples out there?

Hi. Is ksp still tied to jvm or is it finally mpp? Also is it in the same niche of tooling as arrow-meta?

@Zac Sweers can you give me a reproduce repo for your

CompilationErrorException

use case?

How can I get annotations from a property?

data class Sample(
    @Json(name = "full_name") val fullName: String
)

// in KSP
KSClassDeclaration.getAllProperties().forEach {
    it.annotations // => empty list
}

KSP just came across my radar. At first glance, it looks like an awesome tool to support the development of Kotlin related LSP clients and servers, for which I am working on both. The answer to this question will be telling: given a hello world program that contains

println("Hello World")

can KSP easily access the declaration of "println"? I.e. can KSP drill into the runtime jar file, extract the definition/declaration of standard language symbols and provide those to an interested tool leveraging KSP?

would you be up for making SymbolProcessor.onFinish have a no-op default implementation? I find I never implement it in the processors I've written

another qq - I saw the new test configurations followed kapt's

<config>Test

naming convention rather than the conventional

test<config>

convention used everywhere else. Was there a specific reason for this? If not - would you be open to changing it? This is always a huge headache when repo maintainers try to automatically manage some configurations for tests and have to add special rules for kapt's backward naming

I'm looking at making a PR for sealedSubclasses. It looks fairly simple, the only hard part is making sure it works with incremental. I can kind of eyeball how other APIs support it, but I'd be curious if there's any docs/guidelines for it. I could also start with a PR of what I have and continue in there if that's easier, let me know

How would I get the class of a KSPropertyDeclaration? I can see

it.type.resolve()

is a

KSType

, and I see

isAssignableFrom(KSType)

but still not sure how to compare it to a

KClass

like

Module::class.java

we've shipped first version of Room that supports KSP: https://developer.android.com/jetpack/androidx/releases/room#2.3.0-beta02

Suppose a code like this:

class Outer<T> {
    inner class Inner
}

val foo: Outer<String>.Inner
    get() = TODO()

Is there a way to get the type argument

String

from

KSPropertyDeclaration.type

of the property

foo

? I tried

fooPropertyDeclaration.type.resolve().declaration.parentDeclaration?.typeParameters?.get(0)

, but it was

T

, not

String

.

Hi, here is my planned change to how KSP should handle exceptions https://github.com/google/ksp/pull/321 (you can ignore the code change and only look at the document change on

SymbolProcessor

. I’d like to open up for discussion and hear back from you on how you think about this exception handling on how it can impact your developing experience (in good way or bad way). Mainly I would like feedbacks on whether other processors should continue processing when one processor throws an exception.

Is there any equivalent in KSP for

javax.lang.model.element.PackageElement

? As far as I can tell there isn’t a

KSAnnotated

representation of a package (potentially because package-info.java is not used in kotlin?) I have a javac processor that looks up annotations on package elements and am wondering how KSP handles that. Similarly, does KSP provide any way to resolve the package by name? In javac we can do

Elements.getPackageElement(CharSequence)

to get a package, which then provides access to all elements in that package (including elements from other modules). We have used this to enable a single module to aggregate the generated files of other modules, by putting them all in the same package. I’m trying to figure out how to translate this to KSP

Hello, guys, I am wondering what are the practical differences of incremental processing to processors, and if I need to make anything specific to assure that a processor I created is incremental. After reading some documentation regarding KAPT, It seems to me that as long as the only code that change is internal code inside methods, symbol processing will not kick in. But as soon as there’s some other kind of change, the entire processing will be done from square one. I was wondering if that’s the case, or if it would mean symbol processing would only process symbols that changed (i.e.: new/modified annotated classes), while caching symbols that have been previously successfully processed, and passing the cached data down to processors along with what’s new.

👋 Am I understanding correctly that KSP only works with one Gradle module? So a symbol processor cannot process annotated classes from other Gradle modules?

I'm happy to hear that you liked it. Btw, you didn't need to copy that, it is already in gmaven, we just don't advertise it as a standalone library. There is always an option that we might make it more visible but this ksp-room project had enough many moving pieces and i didn't want to add more complexity.

We are also considering using it for dagger but the apis are haavily optimized for kotlin and most of dagger is in Java so may not work well.

ah no I meant in kotlinpoet directly, as another artifact. To cover some simple cases of KS* types to KotlinPoet

Would be great to have all of it out of the box

This is what we have: https://cs.android.com/androidx/platform/frameworks/support/+/androidx-main:room/compiler-processing/src/main/java/androidx/room/compiler/processing/ksp/KSTypeExt.kt

ok i talked w/ AndoridX folks and got the buy in to ship the testing artifact. We'll annotate them w/ some requires opt in though and will still NOT advertise (so no API stability, release notes etc, for now). as things progress, we can consider upgrading it to a real library if it becomes useful for many libraries. meanwhile, i highligy recommend proguarding it. Idk if javaap or KSP does any classloader isolation

https://cs.android.com/androidx/platform/frameworks/support/+/androidx-main:room/compiler-processing-testing/ it provides some APIs to run the same processing test w/ all 3 backends (javaap, ksp, kapt)

Does Compose use KSP?

Hi everyone, I’m currently searching for a way to simply test a KSP processor - any recommendations? (I already googled a little to find any library / way to simply test a KSP processor).

Hi, here is our biweekly release for KSP: https://github.com/google/ksp/releases/tag/1.4.30-1.0.0-alpha05 Highlights • synthetic property accessors now can be correctly created for abstract classes, align with compiler behavior. • Removed 

findAnnotationFromUseSiteTarget()

 function, consolidate its functionality into KSP internal logic. Behavior change • KSP now handles annotation use site targets internally for property accessors (namely 

@get:Anno

, 

@set:Anno

). ◦ property accessors will have corresponding targeted annotations from their receiver properties ◦ annotations with 

@get:

 and 

@set:

 targets will not appear in property’s annotation list.

for those who wants to play w/ Room's abstraction, i added a super simple README that should help you find your way around. https://github.com/androidx/androidx/tree/androidx-main/room/compiler-processing

What is a recommended way to write simple test to KSP plugin? I've played with

"com.github.tschuchortdev:kotlin-compile-testing

a little bit, but not success yet. It works well with kotlinc plugins, even debugging is possible ...

I'm having a problem with compiler testing. For some reason, it does not detect KSP generated files. They have been successfully generated and it's possible to browse to them throught the file system, but they're not reported on the compilation result. It looks like it's looking for kapt generated stuff instead. Here's how I'm running it: <inside thread>