Fix classpath when source set has no metadata compilations by adam-enko · Pull Request #4296 · Kotlin/dokka

adam-enko · 2025-10-14T15:28:00Z

This PR contains a fix for two situations where a source set's classpath does not contain the required KMP klibs for Dokka to resolve symbols in the source set's code.

Fix 'bamboo' source sets.

If an intermediate source set only has one actual KMP target this is informally known as a 'bamboo' source set (because, unlike a 'tree', a bamboo does not have branches).

For example, windowsMain and mingwMain only have one target: mingwX64Main.

In KotlinAdapter an intermediate source set does not have any primaryCompilations.
If an intermediate source set only has a single 'associated compilation' then it will be considered as a 'bamboo' source set. The single 'associated compilation' is the actual target compilation. and DGP will use the classpath of actual target.

Fixes #3386

Workaround no metadata compilations for shared Wasm source sets (workaround for KT-80551)

KGP registers metadata compilations for source sets that have multiple native compilations, but not for multiple wasm source sets.

This PR works around this by using an internal KGP function to register the metadata compilation for shared wasm source sets.

Workaround for:

Stop adding source directories to classpath

For some reason DGPv2 adds source directories to the classpath. I didn't dig into the reason, but it seems to have no purpose. So I just removed this:

https://github.com/Kotlin/dokka/blob/v2.1.0/dokka-runners/dokka-gradle-plugin/src/main/kotlin/adapters/KotlinAdapter.kt#L204-L206

Fix and update kotlin-multiplatform-example

Update kotlin-multiplatform-example to be compilable (it wasn't compilable before!)
Add 'webMain' test.

whyoleg

Please take a look on the comment in KotlinAdapter

examples/gradle-v2/kotlin-multiplatform-example/build.gradle.kts

dokka-runners/dokka-gradle-plugin/src/main/kotlin/adapters/KotlinAdapter.kt

adam-enko · 2025-11-26T17:12:21Z

I've discussed more with @abdulowork and we think we've found a better workaround. We can use IdeMultiplatformImport to get the same data that IJ uses.

I'll have another attempt...

adam-enko · 2025-12-15T10:52:54Z

Unfortunately while IdeMultiplatformImport returns the required klibs, it doesn't seem to be very stable. The KGP task that uses IdeMultiplatformImport disables CC and caching. In DGP it triggers lots of warnings when used with AGP:

Configuration 'jvmCompileClasspath' was resolved during configuration time.
This is a build performance and scalability issue.
See https://github.com/gradle/gradle/issues/2298

Investigations are ongoing...

### Fix 'bamboo' source sets. If an intermediate source set only has one actual KMP target this is informally known as a 'bamboo' source set (because, unlike a 'tree', a bamboo does not have branches). For example, `windowsMain` and `mingwMain` only have one target: `mingwX64Main`. In `KotlinAdapter` an intermediate source set does not have any `primaryCompilations`. If an intermediate source set only has a single 'associated compilation' then it will be considered as a 'bamboo' source set. The single 'associated compilation' is the actual target compilation. and DGP will use the classpath of actual target. ### Workaround no metadata compilations for shared Wasm source sets (workaround for KT-80551) KGP registers metadata compilations for source sets that have multiple native compilations, but _not_ for multiple wasm source sets. This PR works around this by using an `internal` KGP function to register the metadata compilation for shared wasm source sets. Workaround for: - https://youtrack.jetbrains.com/issue/KT-80551 - #4116 ### Stop adding source directories to classpath For some reason DGPv2 adds source directories to the classpath. I didn't dig into the reason, but it seems to have no purpose. So I just removed this: https://github.com/Kotlin/dokka/blob/v2.1.0/dokka-runners/dokka-gradle-plugin/src/main/kotlin/adapters/KotlinAdapter.kt#L204-L206

…pilable before!) - Add 'webMain' source set.

…dates

whyoleg

Overall, the changes appear to be fine, and the workaround for the problem seems quite isolated.
The only thing that bothers me is that it looks like the fix on the KGP side - just compiling wasmJs + wasmWasi as if it were wasmWasi + native, e.g., via metadata compilation - might have been easier :)

dokka-runners/dokka-gradle-plugin/src/main/kotlin/adapters/KotlinAdapter.kt

...unners/dokka-gradle-plugin/src/main/kotlin/adapters/TransformedMetadataDependencyProvider.kt

…()` in separate file to avoid file-level `internal` suppression, and add failure handling inside `map {}`.

adam-enko · 2026-01-08T09:40:38Z

Failing tests are due to the year change, and are fixed by #4406

…ations

whyoleg

Nice! Thanks for the hard work on finding how to fix this on Dokka side!

adam-enko added the runner: Gradle plugin An issue/PR related to Dokka's Gradle plugin label Oct 14, 2025

adam-enko changed the base branch from master to adam/support-agp-kotlin-builtin October 14, 2025 15:28

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adam-enko force-pushed the adam/support-agp-kotlin-builtin branch from 12c2bb1 to 4dd9e43 Compare November 5, 2025 09:26

adam-enko force-pushed the adam/fix-classpath-without-metadata-compilations branch from 4cddab4 to 685f09b Compare November 6, 2025 17:03

adam-enko force-pushed the adam/support-agp-kotlin-builtin branch from d2b6dd7 to 747573f Compare November 10, 2025 17:38

adam-enko self-assigned this Nov 10, 2025

adam-enko force-pushed the adam/fix-classpath-without-metadata-compilations branch from 685f09b to 62d4bff Compare November 10, 2025 18:02

adam-enko mentioned this pull request Nov 24, 2025

KGP IT: test example projects can be assembled #4368

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adam-enko force-pushed the adam/fix-classpath-without-metadata-compilations branch from d249aa3 to ab74561 Compare November 24, 2025 18:36

adam-enko changed the base branch from adam/support-agp-kotlin-builtin to master November 24, 2025 18:37

adam-enko requested review from ALikhachev and whyoleg November 25, 2025 08:04

adam-enko marked this pull request as ready for review November 25, 2025 08:04

whyoleg requested changes Nov 26, 2025

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adam-enko force-pushed the adam/fix-classpath-without-metadata-compilations branch from 452538e to 55e4830 Compare November 26, 2025 15:07

adam-enko marked this pull request as draft November 26, 2025 17:12

adam-enko added 6 commits December 18, 2025 11:42

Test project with custom shared Wasm source set

a50c0af

fix code warnings

26fc02b

test v2 examples are compilable

c4819f2

- Update kotlin-multiplatform-example to be compilable (it wasn't com…

f690132

…pilable before!) - Add 'webMain' source set.

update test data to reflect fixes and kotlin-multiplatform-example up…

c49cefc

…dates

adam-enko force-pushed the adam/fix-classpath-without-metadata-compilations branch from 54135fe to c49cefc Compare December 18, 2025 10:43

formatting

bedb0d6

adam-enko marked this pull request as ready for review December 18, 2025 16:38

adam-enko requested a review from antohaby December 18, 2025 16:38

whyoleg self-requested a review December 22, 2025 10:40

whyoleg reviewed Dec 22, 2025

View reviewed changes

add wrapper for `locateOrRegisterMetadataDependencyTransformationTask…

66b02f1

…()` in separate file to avoid file-level `internal` suppression, and add failure handling inside `map {}`.

adam-enko added 3 commits January 8, 2026 10:41

Merge branch 'master' into adam/fix-classpath-without-metadata-compil…

440bee1

…ations

clarify bamboo sources set handling

c01bdcd

Merge branch 'master' into adam/fix-classpath-without-metadata-compil…

c3b555b

…ations

whyoleg approved these changes Jan 8, 2026

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whyoleg linked an issue Jan 8, 2026 that may be closed by this pull request

[K2] kotlinx-io: Error classes on Wasm platform #4116

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adam-enko merged commit d67cf0c into master Jan 8, 2026
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adam-enko deleted the adam/fix-classpath-without-metadata-compilations branch January 8, 2026 16:09

vmishenev mentioned this pull request Jan 20, 2026

Split package (cross module) links not working #4364

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Fix classpath when source set has no metadata compilations#4296

Fix classpath when source set has no metadata compilations#4296
adam-enko merged 11 commits intomasterfrom
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adam-enko commented Oct 14, 2025 •

edited by whyoleg

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adam-enko commented Oct 14, 2025 • edited by whyoleg Loading Uh oh! There was an error while loading. Please reload this page.

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Fix 'bamboo' source sets.

Workaround no metadata compilations for shared Wasm source sets (workaround for KT-80551)

Stop adding source directories to classpath

Fix and update kotlin-multiplatform-example

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adam-enko commented Oct 14, 2025 •

edited by whyoleg

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