fix: generate supergraph just once per variant (source set).

src/main/kotlin/com/autonomousapps/internal/graph/supers/SuperClassGraphBuilder.kt

@@ -3,6 +3,7 @@ package com.autonomousapps.internal.graph.supers
 import com.autonomousapps.internal.graph.newGraphBuilder
 import com.autonomousapps.model.Coordinates
 import com.autonomousapps.model.internal.BinaryClassCapability
+import com.autonomousapps.model.internal.Dependency
 import com.autonomousapps.visitor.GraphViewVisitor
 import com.google.common.graph.Graph
 
@@ -42,10 +43,10 @@ internal class SuperClassGraphBuilder {
 
   companion object {
     /** Builds a graph from child classes up through super classes and interfaces, up to `java.lang.Object`. */
-    fun of(context: GraphViewVisitor.Context): Graph<SuperNode> {
+    fun of(dependencies: Set<Dependency>): Graph<SuperNode> {
       val builder = SuperClassGraphBuilder()
 
-      context.dependencies.forEach { dep ->
+      dependencies.forEach { dep ->
         dep.findCapability<BinaryClassCapability>()?.let { capability ->
           capability.binaryClasses.map { bin ->
             val from = SuperNode(bin.className).apply {

src/main/kotlin/com/autonomousapps/model/internal/ProjectVariant.kt

@@ -3,14 +3,11 @@
 package com.autonomousapps.model.internal
 
 import com.autonomousapps.internal.unsafeLazy
-import com.autonomousapps.internal.utils.flatMapToOrderedSet
-import com.autonomousapps.internal.utils.flatMapToSet
-import com.autonomousapps.internal.utils.fromJson
-import com.autonomousapps.model.internal.CodeSource.Kind
+import com.autonomousapps.internal.utils.*
 import com.autonomousapps.model.Coordinates
 import com.autonomousapps.model.ProjectCoordinates
 import com.autonomousapps.model.declaration.Variant
-import com.autonomousapps.model.internal.intermediates.consumer.MemberAccess
+import com.autonomousapps.model.internal.CodeSource.Kind
 import com.squareup.moshi.JsonClass
 import org.gradle.api.file.Directory
 
@@ -86,6 +83,22 @@ internal data class ProjectVariant(
     usedNonAnnotationClasses - exposedClasses
   }
 
+  /**
+   * The set of super classes and interfaces not available from [codeSource] (therefore "external" to "this" module).
+   */
+  val externalSupers: Set<String> by unsafeLazy {
+    val supers = codeSource.mapNotNullToOrderedSet { src -> src.superClass }
+    val interfaces = codeSource.flatMapToOrderedSet { src -> src.interfaces }
+    // These are all the super classes and interfaces in "this" module
+    val localClasses = codeSource.mapToOrderedSet { src -> src.className }
+    // These super classes and interfaces are not available from "this" module, so must come from dependencies.
+    val externalSupers = supers - localClasses
+    val externalInterfaces = interfaces - localClasses
+    val externals = externalSupers + externalInterfaces
+
+    externals
+  }
+
   val androidResSource: List<AndroidResSource> by unsafeLazy {
     sources.filterIsInstance<AndroidResSource>()
   }

src/main/kotlin/com/autonomousapps/tasks/ComputeUsagesTask.kt

@@ -5,7 +5,6 @@ package com.autonomousapps.tasks
 import com.autonomousapps.graph.Graphs.parents
 import com.autonomousapps.graph.Graphs.reachableNodes
 import com.autonomousapps.graph.Graphs.root
-import com.autonomousapps.internal.graph.supers.SuperClassGraphHolder
 import com.autonomousapps.internal.graph.supers.SuperNode
 import com.autonomousapps.internal.utils.*
 import com.autonomousapps.model.Coordinates
@@ -122,8 +121,6 @@ private class GraphVisitor(
   private val kapt: Boolean,
 ) : GraphViewVisitor {
 
-  private lateinit var superClassGraphHolder: SuperClassGraphHolder
-
   val report: DependencyTraceReport get() = reportBuilder.build()
 
   private val reportBuilder = DependencyTraceReport.Builder(
@@ -134,7 +131,6 @@ private class GraphVisitor(
 
   override fun visit(dependency: Dependency, context: GraphViewVisitor.Context) {
     val dependencyCoordinates = dependency.coordinates
-    superClassGraphHolder = SuperClassGraphHolder(context)
 
     var isAnnotationProcessor = false
     var isAnnotationProcessorCandidate = false
@@ -371,16 +367,15 @@ private class GraphVisitor(
     }
   }
 
-  // TODO(tsr): consider providing an opt-out or even an opt-in for this (very expensive) analysis.
   private fun isForMissingSuperclass(
     coordinates: Coordinates,
     capability: BinaryClassCapability,
     context: GraphViewVisitor.Context,
   ): Boolean {
-    val superGraph = superClassGraphHolder.superGraph
+    val superGraph = context.superGraph
 
     // collect all the dependencies associated with external supers
-    val requiredExternalClasses = superClassGraphHolder.externals.asSequence()
+    val requiredExternalClasses = context.project.externalSupers.asSequence()
       .flatMap { external -> superGraph.reachableNodes(false) { it.className == external } }
       .mapNotNull { node ->
         val deps = node.deps.filterToOrderedSet { dep ->

src/main/kotlin/com/autonomousapps/visitor/GraphViewReader.kt

@@ -2,11 +2,15 @@
 // SPDX-License-Identifier: Apache-2.0
 package com.autonomousapps.visitor
 
+import com.autonomousapps.internal.graph.supers.SuperClassGraphBuilder
+import com.autonomousapps.internal.graph.supers.SuperNode
+import com.autonomousapps.internal.unsafeLazy
+import com.autonomousapps.model.DuplicateClass
+import com.autonomousapps.model.declaration.internal.Declaration
 import com.autonomousapps.model.internal.Dependency
 import com.autonomousapps.model.internal.DependencyGraphView
-import com.autonomousapps.model.DuplicateClass
 import com.autonomousapps.model.internal.ProjectVariant
-import com.autonomousapps.model.declaration.internal.Declaration
+import com.google.common.graph.Graph
 
 internal class GraphViewReader(
   private val project: ProjectVariant,
@@ -30,4 +34,9 @@ internal class DefaultContext(
   override val graph: DependencyGraphView,
   override val declarations: Set<Declaration>,
   override val duplicateClasses: Set<DuplicateClass>,
-) : GraphViewVisitor.Context
+) : GraphViewVisitor.Context {
+
+  override val superGraph: Graph<SuperNode> by unsafeLazy {
+    SuperClassGraphBuilder.of(dependencies)
+  }
+}

src/main/kotlin/com/autonomousapps/visitor/GraphViewVisitor.kt

@@ -2,11 +2,13 @@
 // SPDX-License-Identifier: Apache-2.0
 package com.autonomousapps.visitor
 
+import com.autonomousapps.internal.graph.supers.SuperNode
 import com.autonomousapps.model.internal.Dependency
 import com.autonomousapps.model.internal.DependencyGraphView
 import com.autonomousapps.model.DuplicateClass
 import com.autonomousapps.model.internal.ProjectVariant
 import com.autonomousapps.model.declaration.internal.Declaration
+import com.google.common.graph.Graph
 
 internal interface GraphViewVisitor {
   fun visit(dependency: Dependency, context: Context)
@@ -17,5 +19,8 @@ internal interface GraphViewVisitor {
     val graph: DependencyGraphView
     val declarations: Set<Declaration>
     val duplicateClasses: Set<DuplicateClass>
+
+    /** Graph from child classes up through super classes and interfaces, up to `java/lang/Object`. */
+    val superGraph: Graph<SuperNode>
   }
 }