ADFA-5195: Generate R8 keep rules for the published plugin ABI

app/build.gradle.kts

@@ -517,53 +517,140 @@ tasks.register<Zip>("createPluginArtifactsZip") {
 // Merges the API surface plugins already compile against (plugin-api + common +
 // eventbus-events + idetooltips) into one coordinate. The three add-ons are
 // v7/v8-flavored (unlike plugin-api); their classes are ABI-neutral so v8 is used.
-tasks.register<Jar>("assemblePluginApiFatJar") {
-	dependsOn(
-		":plugin-api:assembleRelease",
-		":common:assembleV8Release",
-		":eventbus-events:assembleV8Release",
-		":idetooltips:assembleV8Release",
-	)
-	archiveFileName.set("plugin-api-1.0.0.jar")
-	destinationDirectory.set(layout.buildDirectory.dir("plugin-maven-repo-staging"))
-	duplicatesStrategy = DuplicatesStrategy.EXCLUDE
-
-	from(
-		zipTree(
-			project(":plugin-api")
-				.layout.buildDirectory
-				.file("intermediates/aar_main_jar/release/syncReleaseLibJars/classes.jar")
-				.get()
-				.asFile,
-		),
-	)
-	from(
-		zipTree(
-			project(":common")
-				.layout.buildDirectory
-				.file("intermediates/aar_main_jar/v8Release/syncV8ReleaseLibJars/classes.jar")
-				.get()
-				.asFile,
-		),
-	)
-	from(
-		zipTree(
-			project(":eventbus-events")
-				.layout.buildDirectory
-				.file("intermediates/aar_main_jar/v8Release/syncV8ReleaseLibJars/classes.jar")
-				.get()
-				.asFile,
-		),
-	)
-	from(
-		zipTree(
-			project(":idetooltips")
-				.layout.buildDirectory
-				.file("intermediates/aar_main_jar/v8Release/syncV8ReleaseLibJars/classes.jar")
-				.get()
-				.asFile,
-		),
-	)
+val pluginApiFatJar =
+	tasks.register<Jar>("assemblePluginApiFatJar") {
+		dependsOn(
+			":plugin-api:assembleRelease",
+			":common:assembleV8Release",
+			":eventbus-events:assembleV8Release",
+			":idetooltips:assembleV8Release",
+		)
+		archiveFileName.set("plugin-api-1.0.0.jar")
+		destinationDirectory.set(layout.buildDirectory.dir("plugin-maven-repo-staging"))
+		duplicatesStrategy = DuplicatesStrategy.EXCLUDE
+
+		from(
+			zipTree(
+				project(":plugin-api")
+					.layout.buildDirectory
+					.file("intermediates/aar_main_jar/release/syncReleaseLibJars/classes.jar")
+					.get()
+					.asFile,
+			),
+		)
+		from(
+			zipTree(
+				project(":common")
+					.layout.buildDirectory
+					.file("intermediates/aar_main_jar/v8Release/syncV8ReleaseLibJars/classes.jar")
+					.get()
+					.asFile,
+			),
+		)
+		from(
+			zipTree(
+				project(":eventbus-events")
+					.layout.buildDirectory
+					.file("intermediates/aar_main_jar/v8Release/syncV8ReleaseLibJars/classes.jar")
+					.get()
+					.asFile,
+			),
+		)
+		from(
+			zipTree(
+				project(":idetooltips")
+					.layout.buildDirectory
+					.file("intermediates/aar_main_jar/v8Release/syncV8ReleaseLibJars/classes.jar")
+					.get()
+					.asFile,
+			),
+		)
+	}
+
+// Plugins load through DexClassLoader, so R8 never sees a reference to the ABI
+// they call. Emitting one -keep per class in the fat jar published above makes
+// the rules exactly the published ABI, so they cannot drift as classes move
+// between the four merged modules.
+abstract class GeneratePluginApiKeepRules : DefaultTask() {
+	@get:InputFile
+	abstract val fatJar: RegularFileProperty
+
+	// Module path -> a class that module must contribute. The fat jar merges four
+	// hardcoded AGP intermediate paths with DuplicatesStrategy.EXCLUDE, so a path
+	// that stops resolving (AGP layout change, dropped from(...)) drops that
+	// module's classes silently instead of failing.
+	@get:Input
+	abstract val sentinelClasses: MapProperty<String, String>
+
+	@get:OutputFile
+	abstract val keepRules: RegularFileProperty
+
+	@TaskAction
+	fun generate() {
+		val jar = fatJar.get().asFile
+		val classes =
+			ZipFile(jar).use { zip ->
+				zip
+					.entries()
+					.asSequence()
+					.map { it.name }
+					.filter { it.endsWith(".class") }
+					.map { it.removeSuffix(".class").replace('/', '.') }
+					.sorted()
+					.toList()
+			}
+
+		check(classes.isNotEmpty()) {
+			"$jar holds no classes; generating keep rules from it would ship the plugin ABI unprotected."
+		}
+
+		val present = classes.toSet()
+		val missing = sentinelClasses.get().filterValues { it !in present }
+		check(missing.isEmpty()) {
+			missing.entries.joinToString(
+				prefix = "$jar is missing whole modules, so their ABI would ship unprotected: ",
+			) { "${it.key} (no ${it.value})" }
+		}
+
+		val header =
+			"""
+			# Generated by :app:generatePluginApiKeepRules -- do not edit.
+			# One -keep per class in the published plugin-api fat jar: plugins resolve the
+			# ABI parent-first through DexClassLoader, which R8 cannot see.
+			#
+			# These cover the ABI only. Plugins also resolve kotlin.** from the app's dex,
+			# which app/proguard-rules.pro keeps separately (ADFA-5156).
+
+			""".trimIndent()
+
+		val file = keepRules.get().asFile
+		file.parentFile.mkdirs()
+		file.writeText(
+			classes.joinToString("\n", prefix = header, postfix = "\n") { "-keep class $it { *; }" },
+		)
+		logger.lifecycle("Wrote ${classes.size} plugin-ABI keep rules to ${file.absolutePath}")
+	}
+}
+
+val pluginApiKeepRules =
+	tasks.register<GeneratePluginApiKeepRules>("generatePluginApiKeepRules") {
+		fatJar.set(pluginApiFatJar.flatMap { it.archiveFile })
+		sentinelClasses.set(
+			mapOf(
+				":plugin-api" to "com.itsaky.androidide.plugins.IPlugin",
+				":common" to "com.itsaky.androidide.utils.Environment",
+				":eventbus-events" to "com.itsaky.androidide.eventbus.events.Event",
+				":idetooltips" to "com.itsaky.androidide.idetooltips.IDETooltipItem",
+			),
+		)
+		keepRules.set(layout.buildDirectory.file("generated/proguard/plugin-api-keep.pro"))
+	}
+
+// proguardFiles (not dependsOn) so Gradle infers the dependency for every
+// consumer: R8 and lint both read this list, and wiring only R8 fails validation
+// in a real release build. Debug variants stay off the fat jar entirely.
+androidComponents.onVariants(androidComponents.selector().withBuildType("release")) { variant ->
+	variant.proguardFiles.add(pluginApiKeepRules.flatMap { it.keepRules })
 }
 
 // Dependency-free POM for the fat plugin-api coordinate: it is compile-only/provided,

app/proguard-rules.pro

@@ -193,16 +193,25 @@
 -keep class io.sentry.** { *; }
 -dontwarn io.sentry.**
 
-# ADFA-5156: TEMPORARY ROLLBACK of the R8 shrinking re-enabled in ADFA-3604.
-# Plugins load parent-first through a stock DexClassLoader, so they resolve
-# kotlin.** from the app's dex rather than their own bundled stdlib. R8 cannot
-# see plugin call sites, so it strips every stdlib member the IDE itself does
-# not call and plugins die with NoSuchMethodError at runtime (Sketch to UI:
-# ArraysKt.maxOrNull([F)). With -dontobfuscate and -dontoptimize already set,
-# this restores R8 to a pass-through and returns the release build to the
-# configuration shipped before ADFA-3604. Revert once ADFA-5156 lands a
-# targeted fix (keep rules for kotlin.**/kotlinx.coroutines.**).
--dontshrink
+# ADFA-5156: plugins load parent-first through a stock DexClassLoader, so they
+# resolve kotlin.** from the app's dex rather than their own bundled stdlib. R8
+# cannot see plugin call sites, so it strips every stdlib member the IDE itself
+# does not call and plugins die with NoSuchMethodError at runtime (Sketch to UI:
+# ArraysKt.maxOrNull([F)). ADFA-5156 first fixed this with -dontshrink, which
+# made R8 a pass-through over the whole app to protect one library; ADFA-5195
+# replaced it with the targeted keeps below, restoring dead-code removal
+# everywhere else.
+#
+# ADFA-5164 narrows this: freeze the stdlib subset plugins may rely on and have
+# plugins bundle the rest. Until then the whole stdlib is the contract, so these
+# stay broad -- and note the keeps further up cover only kotlin.reflect,
+# kotlin.script and kotlinx.coroutines.internal, not kotlin.collections/text/io/
+# sequences, which is the hole maxOrNull([F) fell through.
+-keep class kotlin.** { *; }
+-keep class kotlinx.coroutines.** { *; }
+
+-keep class com.google.firebase.** { *; }
+-keep class com.google.android.gms.** { *; }
 
 ## Plugin SPI
 ## Plugins are loaded dynamically via DexClassLoader, so R8 cannot see their