autonomousapps/dependency-analysis-gradle-plugin

Kotlin removes unreachable bytecode causing DAGP to think a dependency is unused

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#1,429 opened on Apr 30, 2025

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Description

Plugin version 2.17.0

Gradle version 8.14

JDK version 17

(Optional) Kotlin and Kotlin Gradle Plugin (KGP) version 2.1.20

Describe the bug Kotlin optimizes out unreachable bytecode like if (false) so if a usage of a dependency is inside of that block, DAGP considers it unused and will remove it. Removing it causes a compilation failure.

To Reproduce Steps to reproduce the behavior:

  1. In the attached project, :app:fixDependencies removes the dependency on :utils
  2. Running :app:assemble will have a compilation error because the dependency was removed

Expected behavior The :utils dependency should not be removed by fixDependencies and should be reported in build health as being used.

dagp-if-false-repro.zip

Contributor guide

Research direction
Investigate how the dependency analysis gradle plugin scans bytecode. Look for handling of dead code blocks like `if(false)` and understand how Kotlin compiler optimizations affect unreachable bytecode. Propose a change to consider dependencies used inside dead code as still used.
Tech stack
kotlin
Domain
build systemdevtools
Issue type
Bug
DifficultyEstimated implementation difficulty for a new contributor, from 1 for very small changes to 5 for expert-level work.
3
Estimated timeA rough time range for an experienced contributor to investigate, implement, test, and prepare a pull request.
Half day
Activity statusHow available the issue appears right now: fresh, active, stale, blocked, or waiting on maintainer input.
Active
ClarityHow clearly the issue explains the expected change, acceptance criteria, and next step.
Clear
Prerequisites
KotlinGradle
Newbie friendlinessA 1-100 score estimating how approachable this issue is for first-time contributors.
70