feat: special support for @composable when doing binary compatibility checks.

Author: autonomousapps

src/main/kotlin/com/autonomousapps/internal/asm.kt

@@ -9,8 +9,8 @@ import com.autonomousapps.internal.kotlin.AccessFlags
 import com.autonomousapps.internal.utils.METHOD_DESCRIPTOR_REGEX
 import com.autonomousapps.internal.utils.efficient
 import com.autonomousapps.internal.utils.genericTypes
-import com.autonomousapps.model.internal.intermediates.producer.Member
 import com.autonomousapps.model.internal.intermediates.consumer.MemberAccess
+import com.autonomousapps.model.internal.intermediates.producer.Member
 import kotlinx.metadata.jvm.Metadata
 import org.gradle.api.logging.Logger
 import java.util.SortedSet
@@ -19,7 +19,10 @@ import java.util.concurrent.atomic.AtomicReference
 private val logDebug: Boolean get() = Flags.logBytecodeDebug()
 private const val ASM_VERSION = Opcodes.ASM9
 
-/** This will collect the class name and information about annotations. */
+/**
+ * This will collect the class name and information about annotations. It is used on the "producer" side to create
+ * the [ExplodedJar][com.autonomousapps.model.internal.intermediates.producer.ExplodedJar] model, via [AnalyzedClass].
+ */
 internal class ClassNameAndAnnotationsVisitor(private val logger: Logger) : ClassVisitor(ASM_VERSION) {
 
   private lateinit var className: String
@@ -98,7 +101,7 @@ internal class ClassNameAndAnnotationsVisitor(private val logger: Logger) : Clas
 
   override fun visitMethod(
     access: Int, name: String, descriptor: String, signature: String?, exceptions: Array<out String>?
-  ): MethodVisitor? {
+  ): MethodVisitor {
     log { "- visitMethod: ${Access.fromInt(access)} descriptor=$descriptor name=$name signature=$signature" }
 
     if (!("()V" == descriptor && ("<init>" == name || "<clinit>" == name))) {
@@ -107,17 +110,17 @@ internal class ClassNameAndAnnotationsVisitor(private val logger: Logger) : Clas
       methods.add(Method(descriptor))
     }
 
+    var method: Member.Method? = null
     if (isEffectivelyPublic(access)) {
-      effectivelyPublicMethods.add(
-        Member.Method(
-          access = access,
-          name = name,
-          descriptor = descriptor,
-        )
+      method = Member.Method(
+        access = access,
+        name = name,
+        descriptor = descriptor,
       )
+      effectivelyPublicMethods.add(method)
     }
 
-    return null
+    return MethodAnalyzer(logger, effectivelyPublicMethods, method)
   }
 
   override fun visitField(
@@ -189,6 +192,43 @@ internal class ClassNameAndAnnotationsVisitor(private val logger: Logger) : Clas
       }
     }
   }
+
+  private class MethodAnalyzer(
+    private val logger: Logger,
+    private val effectivelyPublicMethods: MutableSet<Member.Method>,
+    private val method: Member.Method?,
+  ) : MethodVisitor(ASM_VERSION) {
+
+    private fun log(msgProvider: () -> String) {
+      if (!logDebug) {
+        logger.quiet(msgProvider())
+      }
+    }
+
+    override fun visitAnnotation(descriptor: String?, visible: Boolean): AnnotationVisitor? {
+      log { "MethodAnalyzer#visitAnnotation: descriptor=$descriptor visible=$visible" }
+
+      // For @Composable functions, we also add an artificial version that matches what the compose Kotlin compiler
+      // plugin generates. For example:
+      //
+      // * In source, the `isSystemInDarkTheme()` function seems to have the descriptor `()Z` (takes no arguments,
+      //   returns a boolean).
+      // * In the generated bytecode, the descriptor is `(Landroidx/compose/runtime/Composer;I)Z` (takes a Composer and
+      //   an int, returns a boolean).
+      if (descriptor == "Landroidx/compose/runtime/Composable;") {
+        effectivelyPublicMethods
+          .find { method == it }
+          ?.let { m ->
+            // remove the original
+            effectivelyPublicMethods.remove(m)
+            // and add a new version with the special property set
+            effectivelyPublicMethods.add(m.copy(special = Member.SPECIAL_COMPOSABLE))
+          }
+      }
+
+      return null
+    }
+  }
 }
 
 internal data class ClassRef(

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

@@ -188,9 +188,9 @@ internal data class BinaryClassCapability(
   /**
    * Partitions and returns artificial pair of [BinaryClasses][BinaryClass]. Non-null elements indicate relevant (to
    * [memberAccess] matching and non-matching members of this `BinaryClass`. Matching members are binary-compatible; and
-   * non-matching members have the same [name][com.autonomousapps.model.intermediates.producer.Member.name] but
-   * incompatible [descriptors][com.autonomousapps.model.intermediates.producer.Member.descriptor], and are therefore
-   * binary-incompatible.
+   * non-matching members have the same [name][com.autonomousapps.model.internal.intermediates.producer.Member.name] but
+   * incompatible [descriptors][com.autonomousapps.model.internal.intermediates.producer.Member.descriptor], and are
+   * therefore binary-incompatible.
    *
    * nb: We don't want this as a method directly in BinaryClass because it can't safely assert the prerequisite that
    * it's only called on "relevant" classes. THIS class, however, can, via findRelevantBinaryClasses.

src/main/kotlin/com/autonomousapps/model/internal/intermediates/producer/Member.kt

@@ -11,15 +11,20 @@ import dev.zacsweers.moshix.sealed.annotations.TypeLabel
  * Represents a member of a [class][BinaryClass].
  *
  * nb: Borrowing heavily from `asmUtils.kt` and similar but substantially different from
- * [MemberAccess][com.autonomousapps.model.intermediates.consumer.MemberAccess] on the consumer side.
+ * [MemberAccess][com.autonomousapps.model.internal.intermediates.consumer.MemberAccess] on the consumer side.
  */
 @JsonClass(generateAdapter = false, generator = "sealed:type")
 internal sealed class Member(
   open val access: Int,
   open val name: String,
   open val descriptor: String,
+  open val special: String?,
 ) : Comparable<Member> {
 
+  companion object {
+    const val SPECIAL_COMPOSABLE = "@Composable"
+  }
+
   internal class Printable(
     val className: String,
     val memberName: String,
@@ -51,14 +56,23 @@ internal sealed class Member(
       .compare(this, other)
   }
 
-  /** Returns true for matching name and descriptor. */
+  /**
+   * Returns true for matching name and descriptor, unless [special] == [SPECIAL_COMPOSABLE], in which case we relax the
+   * requirement that the descriptors match. `@Composable` functions get special attention from a Kotlin compiler
+   * plugin, such that the source and bytecode do not match.
+   */
   fun matches(memberAccess: MemberAccess): Boolean {
-    return name == memberAccess.name && descriptor == memberAccess.descriptor
+    return name == memberAccess.name
+      && (descriptor == memberAccess.descriptor || special == SPECIAL_COMPOSABLE)
   }
 
-  /** Returns true for matching name and non-matching descriptor. */
+  /**
+   * Returns true for matching name and non-matching descriptor, unless [special] == [SPECIAL_COMPOSABLE], in which case
+   * we can't say that [memberAccess] doesn't match.
+   */
   fun doesNotMatch(memberAccess: MemberAccess): Boolean {
-    return name == memberAccess.name && descriptor != memberAccess.descriptor
+    return name == memberAccess.name
+      && (descriptor != memberAccess.descriptor && special != SPECIAL_COMPOSABLE)
   }
 
   protected val accessFlags get() = AccessFlags(access)
@@ -78,10 +92,12 @@ internal sealed class Member(
     override val access: Int,
     override val name: String,
     override val descriptor: String,
+    override val special: String? = null,
   ) : Member(
     access = access,
     name = name,
     descriptor = descriptor,
+    special = special,
   ) {
     override val signature: String
       get() = "${accessFlags.getModifierString()} fun $name $descriptor"
@@ -93,10 +109,12 @@ internal sealed class Member(
     override val access: Int,
     override val name: String,
     override val descriptor: String,
+    override val special: String? = null,
   ) : Member(
     access = access,
     name = name,
     descriptor = descriptor,
+    special = special,
   ) {
     override val signature: String
       get() = "${accessFlags.getModifierString()} field $name $descriptor"

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

@@ -3,27 +3,11 @@
 package com.autonomousapps.tasks
 
 import com.autonomousapps.internal.utils.*
-import com.autonomousapps.model.*
+import com.autonomousapps.model.Coordinates
+import com.autonomousapps.model.DuplicateClass
 import com.autonomousapps.model.declaration.internal.Bucket
 import com.autonomousapps.model.declaration.internal.Declaration
-import com.autonomousapps.model.internal.AndroidAssetCapability
-import com.autonomousapps.model.internal.AndroidLinterCapability
-import com.autonomousapps.model.internal.AndroidManifestCapability
-import com.autonomousapps.model.internal.AndroidResCapability
-import com.autonomousapps.model.internal.AndroidResSource
-import com.autonomousapps.model.internal.AnnotationProcessorCapability
-import com.autonomousapps.model.internal.BinaryClassCapability
-import com.autonomousapps.model.internal.ClassCapability
-import com.autonomousapps.model.internal.ConstantCapability
-import com.autonomousapps.model.internal.Dependency
-import com.autonomousapps.model.internal.DependencyGraphView
-import com.autonomousapps.model.internal.InferredCapability
-import com.autonomousapps.model.internal.InlineMemberCapability
-import com.autonomousapps.model.internal.NativeLibCapability
-import com.autonomousapps.model.internal.ProjectVariant
-import com.autonomousapps.model.internal.SecurityProviderCapability
-import com.autonomousapps.model.internal.ServiceLoaderCapability
-import com.autonomousapps.model.internal.TypealiasCapability
+import com.autonomousapps.model.internal.*
 import com.autonomousapps.model.internal.intermediates.DependencyTraceReport
 import com.autonomousapps.model.internal.intermediates.DependencyTraceReport.Kind
 import com.autonomousapps.model.internal.intermediates.Reason
@@ -422,7 +406,6 @@ private class GraphVisitor(
     // Can't be incompatible if the code compiles in the context of no duplication
     if (context.duplicateClasses.isEmpty()) return
 
-    // TODO(tsr): special handling for @Composable
     val memberAccessOwners = context.project.memberAccesses.mapToSet { it.owner }
     val relevantDuplicates = context.duplicateClasses
       .filter { duplicate -> coordinates in duplicate.dependencies && duplicate.className in memberAccessOwners }
@@ -435,9 +418,9 @@ private class GraphVisitor(
     val relevantMemberAccesses = context.project.memberAccesses
       .filterToOrderedSet { access -> access.owner in relevantDuplicateClassNames }
 
-    val partitionResult = relevantMemberAccesses.mapToSet { access ->
-      binaryClassCapability.findMatchingClasses(access)
-    }.reduce()
+    val partitionResult = relevantMemberAccesses
+      .mapToSet { access -> binaryClassCapability.findMatchingClasses(access) }
+      .reduce()
     val matchingBinaryClasses = partitionResult.matchingClasses
     val nonMatchingBinaryClasses = partitionResult.nonMatchingClasses