Remove decoys from Compose compiler

Decoys are no longer supported / required for JS compilation.

Relnote: Decoy support for JS target is removed from Compose compiler

plugins/compose/compiler-hosted/integration-tests/src/jvmTest/kotlin/androidx/compose/compiler/plugins/kotlin/facade/KotlinCompilerFacade.kt

@@ -118,7 +118,7 @@ abstract class KotlinCompilerFacade(val environment: KotlinCoreEnvironment) {
                 disposable, configuration, EnvironmentConfigFiles.JVM_CONFIG_FILES
             )
 
-            ComposePluginRegistrar.checkCompilerVersion(configuration)
+            ComposePluginRegistrar.checkCompilerConfiguration(configuration)
 
             environment.project.registerExtensions(configuration)
 

plugins/compose/compiler-hosted/src/main/java/androidx/compose/compiler/plugins/kotlin/ComposeIrGenerationExtension.kt

@@ -20,37 +20,25 @@ import androidx.compose.compiler.plugins.kotlin.analysis.FqNameMatcher
 import androidx.compose.compiler.plugins.kotlin.analysis.StabilityInferencer
 import androidx.compose.compiler.plugins.kotlin.k1.ComposeDescriptorSerializerContext
 import androidx.compose.compiler.plugins.kotlin.lower.*
-import androidx.compose.compiler.plugins.kotlin.lower.decoys.CreateDecoysTransformer
-import androidx.compose.compiler.plugins.kotlin.lower.decoys.RecordDecoySignaturesTransformer
-import androidx.compose.compiler.plugins.kotlin.lower.decoys.SubstituteDecoyCallsTransformer
 import androidx.compose.compiler.plugins.kotlin.lower.hiddenfromobjc.AddHiddenFromObjCLowering
 import org.jetbrains.kotlin.backend.common.extensions.IrGenerationExtension
 import org.jetbrains.kotlin.backend.common.extensions.IrPluginContext
-import org.jetbrains.kotlin.backend.common.serialization.DeclarationTable
-import org.jetbrains.kotlin.backend.common.serialization.signature.IdSignatureFactory
-import org.jetbrains.kotlin.backend.common.serialization.signature.PublicIdSignatureComputer
 import org.jetbrains.kotlin.backend.common.validateIr
-import org.jetbrains.kotlin.cli.common.messages.CompilerMessageSeverity
 import org.jetbrains.kotlin.cli.common.messages.MessageCollector
 import org.jetbrains.kotlin.config.IrVerificationMode
-import org.jetbrains.kotlin.descriptors.ClassDescriptor
-import org.jetbrains.kotlin.ir.backend.js.lower.serialization.ir.JsGlobalDeclarationTable
-import org.jetbrains.kotlin.ir.backend.js.lower.serialization.ir.JsManglerIr
 import org.jetbrains.kotlin.ir.declarations.IrModuleFragment
 import org.jetbrains.kotlin.ir.visitors.acceptVoid
 import org.jetbrains.kotlin.platform.isJs
 import org.jetbrains.kotlin.platform.isWasm
 import org.jetbrains.kotlin.platform.jvm.isJvm
 import org.jetbrains.kotlin.platform.konan.isNative
-import org.jetbrains.kotlin.resolve.descriptorUtil.fqNameSafe
 
 class ComposeIrGenerationExtension(
     @Suppress("unused") private val liveLiteralsEnabled: Boolean = false,
     @Suppress("unused") private val liveLiteralsV2Enabled: Boolean = false,
     private val generateFunctionKeyMetaClasses: Boolean = false,
     private val sourceInformationEnabled: Boolean = true,
     private val traceMarkersEnabled: Boolean = true,
-    private val decoysEnabled: Boolean = false,
     private val metricsDestination: String? = null,
     private val reportsDestination: String? = null,
     private val irVerificationMode: IrVerificationMode = IrVerificationMode.NONE,
@@ -176,50 +164,13 @@ class ComposeIrGenerationExtension(
             featureFlags,
         ).lower(moduleFragment)
 
-        val mangler = when {
-            pluginContext.platform.isJs() -> JsManglerIr
-            else -> null
-        }
-
-        val idSignatureBuilder = when {
-            pluginContext.platform.isJs() -> IdSignatureFactory(
-                PublicIdSignatureComputer(mangler!!),
-                DeclarationTable(JsGlobalDeclarationTable(pluginContext.irBuiltIns))
-            )
-            else -> null
-        }
-        if (decoysEnabled) {
-            require(idSignatureBuilder != null) {
-                "decoys are not supported for ${pluginContext.platform}"
-            }
-
-            CreateDecoysTransformer(
-                pluginContext,
-                symbolRemapper,
-                idSignatureBuilder,
-                stabilityInferencer,
-                metrics,
-                featureFlags,
-            ).lower(moduleFragment)
-
-            SubstituteDecoyCallsTransformer(
-                pluginContext,
-                symbolRemapper,
-                idSignatureBuilder,
-                stabilityInferencer,
-                metrics,
-                featureFlags,
-            ).lower(moduleFragment)
-        }
-
         // transform all composable functions to have an extra synthetic composer
         // parameter. this will also transform all types and calls to include the extra
         // parameter.
         ComposerParamTransformer(
             pluginContext,
             symbolRemapper,
             stabilityInferencer,
-            decoysEnabled,
             metrics,
             featureFlags,
         ).lower(moduleFragment)
@@ -234,7 +185,7 @@ class ComposeIrGenerationExtension(
 
         // transform calls to the currentComposer to just use the local parameter from the
         // previous transform
-        ComposerIntrinsicTransformer(pluginContext, decoysEnabled).lower(moduleFragment)
+        ComposerIntrinsicTransformer(pluginContext).lower(moduleFragment)
 
         ComposableFunctionBodyTransformer(
             pluginContext,
@@ -246,22 +197,6 @@ class ComposeIrGenerationExtension(
             featureFlags,
         ).lower(moduleFragment)
 
-        if (decoysEnabled) {
-            require(idSignatureBuilder != null) {
-                "decoys are not supported for ${pluginContext.platform}"
-            }
-
-            RecordDecoySignaturesTransformer(
-                pluginContext,
-                symbolRemapper,
-                idSignatureBuilder,
-                metrics,
-                mangler!!,
-                stabilityInferencer,
-                featureFlags,
-            ).lower(moduleFragment)
-        }
-
         if (isKlibTarget) {
             KlibAssignableParamTransformer(
                 pluginContext,
@@ -277,9 +212,7 @@ class ComposeIrGenerationExtension(
                 pluginContext,
                 symbolRemapper,
                 metrics,
-                idSignatureBuilder,
                 stabilityInferencer,
-                decoysEnabled,
                 featureFlags,
             ).lower(moduleFragment)
         }

plugins/compose/compiler-hosted/src/main/java/androidx/compose/compiler/plugins/kotlin/ComposePlugin.kt

@@ -531,7 +531,7 @@ class ComposePluginRegistrar : CompilerPluginRegistrar() {
         get() = true
 
     override fun ExtensionStorage.registerExtensions(configuration: CompilerConfiguration) {
-        if (checkCompilerVersion(configuration)) {
+        if (checkCompilerConfiguration(configuration)) {
             val usesK2 = configuration.languageVersionSettings.languageVersion.usesK2
             val descriptorSerializerContext =
                 if (usesK2) null
@@ -553,7 +553,7 @@ class ComposePluginRegistrar : CompilerPluginRegistrar() {
     }
 
     companion object {
-        fun checkCompilerVersion(configuration: CompilerConfiguration): Boolean {
+        fun checkCompilerConfiguration(configuration: CompilerConfiguration): Boolean {
             val msgCollector = configuration.messageCollector
             val suppressKotlinVersionCheck = configuration.get(ComposeConfiguration.SUPPRESS_KOTLIN_VERSION_COMPATIBILITY_CHECK)
             if (suppressKotlinVersionCheck != null) {
@@ -568,7 +568,7 @@ class ComposePluginRegistrar : CompilerPluginRegistrar() {
             if (decoysEnabled) {
                 msgCollector.report(
                     CompilerMessageSeverity.ERROR,
-                    "Decoys generation should be disabled for Compose Multiplatform projects"
+                    "Decoys generation is no longer supported by the Compose compiler."
                 )
                 return false
             }
@@ -635,9 +635,6 @@ class ComposePluginRegistrar : CompilerPluginRegistrar() {
                 ComposeConfiguration.NON_SKIPPING_GROUP_OPTIMIZATION_ENABLED_KEY,
                 FeatureFlag.OptimizeNonSkippingGroups.default
             )
-            val decoysEnabled = configuration.getBoolean(
-                ComposeConfiguration.DECOYS_ENABLED_KEY,
-            )
             val metricsDestination = configuration.get(
                 ComposeConfiguration.METRICS_DESTINATION_KEY,
                 ""
@@ -714,7 +711,6 @@ class ComposePluginRegistrar : CompilerPluginRegistrar() {
                 generateFunctionKeyMetaClasses = generateFunctionKeyMetaClasses,
                 sourceInformationEnabled = sourceInformationEnabled,
                 traceMarkersEnabled = traceMarkersEnabled,
-                decoysEnabled = decoysEnabled,
                 metricsDestination = metricsDestination,
                 reportsDestination = reportsDestination,
                 irVerificationMode = irVerificationMode,

plugins/compose/compiler-hosted/src/main/java/androidx/compose/compiler/plugins/kotlin/lower/AbstractComposeLowering.kt

@@ -20,17 +20,16 @@ package androidx.compose.compiler.plugins.kotlin.lower
 
 import androidx.compose.compiler.plugins.kotlin.*
 import androidx.compose.compiler.plugins.kotlin.analysis.*
-import androidx.compose.compiler.plugins.kotlin.lower.decoys.copyWithNewTypeParams
 import androidx.compose.compiler.plugins.kotlin.lower.hiddenfromobjc.hiddenFromObjCClassId
 import org.jetbrains.kotlin.GeneratedDeclarationKey
 import org.jetbrains.kotlin.backend.common.extensions.IrPluginContext
 import org.jetbrains.kotlin.backend.common.lower.DeclarationIrBuilder
 import org.jetbrains.kotlin.backend.jvm.ir.isInlineClassType
 import org.jetbrains.kotlin.builtins.PrimitiveType
-import org.jetbrains.kotlin.descriptors.ClassDescriptor
 import org.jetbrains.kotlin.descriptors.DescriptorVisibilities
 import org.jetbrains.kotlin.fir.declarations.utils.klibSourceFile
 import org.jetbrains.kotlin.fir.lazy.Fir2IrLazyClass
+import org.jetbrains.kotlin.ir.IrElement
 import org.jetbrains.kotlin.ir.IrStatement
 import org.jetbrains.kotlin.ir.ObsoleteDescriptorBasedAPI
 import org.jetbrains.kotlin.ir.UNDEFINED_OFFSET
@@ -50,6 +49,7 @@ import org.jetbrains.kotlin.ir.types.impl.IrSimpleTypeImpl
 import org.jetbrains.kotlin.ir.types.impl.IrStarProjectionImpl
 import org.jetbrains.kotlin.ir.util.*
 import org.jetbrains.kotlin.ir.visitors.IrElementTransformerVoid
+import org.jetbrains.kotlin.ir.visitors.acceptVoid
 import org.jetbrains.kotlin.ir.visitors.transformChildrenVoid
 import org.jetbrains.kotlin.library.metadata.DeserializedSourceFile
 import org.jetbrains.kotlin.load.kotlin.computeJvmDescriptor
@@ -1577,3 +1577,28 @@ inline fun <T> includeFileNameInExceptionTrace(file: IrFile, body: () -> T): T {
 
 fun FqName.topLevelName() =
     asString().substringBefore(".")
+
+internal inline fun <reified T : IrElement> T.copyWithNewTypeParams(
+    source: IrFunction,
+    target: IrFunction
+): T {
+    val typeParamsAwareSymbolRemapper = object : DeepCopySymbolRemapper() {
+        init {
+            for ((orig, new) in source.typeParameters.zip(target.typeParameters)) {
+                typeParameters[orig.symbol] = new.symbol
+            }
+        }
+    }
+    val typeRemapper = DeepCopyTypeRemapper(typeParamsAwareSymbolRemapper)
+    val typeParamRemapper = object : TypeRemapper by typeRemapper {
+        override fun remapType(type: IrType): IrType {
+            return typeRemapper.remapType(type.remapTypeParameters(source, target))
+        }
+    }
+
+    val deepCopy = DeepCopyPreservingMetadata(typeParamsAwareSymbolRemapper, typeParamRemapper)
+    typeRemapper.deepCopy = deepCopy
+
+    acceptVoid(typeParamsAwareSymbolRemapper)
+    return transform(deepCopy, null).patchDeclarationParents(target) as T
+}

plugins/compose/compiler-hosted/src/main/java/androidx/compose/compiler/plugins/kotlin/lower/ComposableFunctionBodyTransformer.kt

@@ -21,7 +21,6 @@ package androidx.compose.compiler.plugins.kotlin.lower
 import androidx.compose.compiler.plugins.kotlin.*
 import androidx.compose.compiler.plugins.kotlin.analysis.*
 import androidx.compose.compiler.plugins.kotlin.lower.ComposerParamTransformer.ComposeDefaultValueStubOrigin
-import androidx.compose.compiler.plugins.kotlin.lower.decoys.DecoyFqNames
 import org.jetbrains.kotlin.backend.common.FileLoweringPass
 import org.jetbrains.kotlin.backend.common.extensions.IrPluginContext
 import org.jetbrains.kotlin.backend.common.lower.DeclarationIrBuilder
@@ -2871,8 +2870,7 @@ class ComposableFunctionBodyTransformer(
                     visitNormalComposableCall(expression)
                 }
             }
-            ComposeFqNames.key,
-            DecoyFqNames.key -> visitKeyCall(expression)
+            ComposeFqNames.key -> visitKeyCall(expression)
             else -> visitNormalComposableCall(expression)
         }
     }

plugins/compose/compiler-hosted/src/main/java/androidx/compose/compiler/plugins/kotlin/lower/ComposableTypeRemapper.kt

@@ -20,7 +20,6 @@ package androidx.compose.compiler.plugins.kotlin.lower
 
 import androidx.compose.compiler.plugins.kotlin.hasComposableAnnotation
 import androidx.compose.compiler.plugins.kotlin.isComposableAnnotation
-import androidx.compose.compiler.plugins.kotlin.lower.decoys.isDecoy
 import org.jetbrains.kotlin.backend.common.extensions.IrPluginContext
 import org.jetbrains.kotlin.backend.common.extensions.IrPluginContextImpl
 import org.jetbrains.kotlin.backend.common.peek
@@ -96,7 +95,7 @@ internal class DeepCopyIrTreeWithRemappedComposableTypes(
                 // so we potentially need to update composable types for it.
                 // if the function is in the current module, it should be updated eventually
                 // by this deep copy pass.
-                if (overriddenFn.needsComposableRemapping() && !overriddenFn.isDecoy()) {
+                if (overriddenFn.needsComposableRemapping()) {
                     overriddenFn.remapTypes(typeRemapper)
                 }
             }
@@ -412,7 +411,7 @@ class ComposerTypeRemapper(
         if (!name.startsWith("Function")) return false
         val packageFqName = cls.owner.packageFqName
         return packageFqName == StandardNames.BUILT_INS_PACKAGE_FQ_NAME ||
-            packageFqName == KotlinFunctionsBuiltInsPackageFqName
+                packageFqName == KotlinFunctionsBuiltInsPackageFqName
     }
 
     private fun IrType.isComposableFunction(): Boolean {
@@ -422,10 +421,6 @@ class ComposerTypeRemapper(
     override fun remapType(type: IrType): IrType {
         if (type !is IrSimpleType) return type
         if (!type.isComposableFunction()) return underlyingRemapType(type)
-        // do not convert types for decoys
-        if (scopeStack.peek()?.isDecoy() == true) {
-            return underlyingRemapType(type)
-        }
 
         val oldIrArguments = type.arguments
         val realParams = oldIrArguments.size - 1
@@ -442,8 +437,8 @@ class ComposerTypeRemapper(
         }
         val newIrArguments =
             oldIrArguments.subList(0, oldIrArguments.size - 1) +
-                extraArgs +
-                oldIrArguments.last()
+                    extraArgs +
+                    oldIrArguments.last()
 
         val newArgSize = oldIrArguments.size - 1 + extraArgs.size
         val functionCls = context.function(newArgSize)

plugins/compose/compiler-hosted/src/main/java/androidx/compose/compiler/plugins/kotlin/lower/ComposerIntrinsicTransformer.kt

@@ -19,7 +19,6 @@
 package androidx.compose.compiler.plugins.kotlin.lower
 
 import androidx.compose.compiler.plugins.kotlin.ComposeFqNames
-import androidx.compose.compiler.plugins.kotlin.lower.decoys.DecoyFqNames
 import org.jetbrains.kotlin.backend.common.FileLoweringPass
 import org.jetbrains.kotlin.backend.common.extensions.IrPluginContext
 import org.jetbrains.kotlin.ir.declarations.IrFile
@@ -35,7 +34,6 @@ import org.jetbrains.kotlin.name.FqName
 
 class ComposerIntrinsicTransformer(
     val context: IrPluginContext,
-    private val decoysEnabled: Boolean
 ) :
     IrElementTransformerVoid(),
     FileLoweringPass,
@@ -45,11 +43,7 @@ class ComposerIntrinsicTransformer(
 
     // get-currentComposer gets transformed as decoy, as the getter now has additional params
     private fun currentComposerFqName(): FqName =
-        if (decoysEnabled) {
-            DecoyFqNames.CurrentComposerIntrinsic
-        } else {
-            ComposeFqNames.CurrentComposerIntrinsic
-        }
+        ComposeFqNames.CurrentComposerIntrinsic
 
     override fun lower(module: IrModuleFragment) {
         module.transformChildrenVoid(this)
@@ -65,7 +59,7 @@ class ComposerIntrinsicTransformer(
             // to this call is the composer itself. We just replace this expression with the
             // argument expression and we are good.
             val expectedArgumentsCount = 1 + // composer parameter
-                1 // changed parameter
+                    1 // changed parameter
             assert(expression.valueArgumentsCount == expectedArgumentsCount) {
                 """
                     Composer call doesn't match expected argument count: