Add new serialization runtime packages

encoding and descriptors. Rename ContextSerializer to Contextual.
Unify getClassFrom*Package functions.

plugins/kotlin-serialization/kotlin-serialization-compiler/src/org/jetbrains/kotlinx/serialization/compiler/backend/jvm/JVMCodegenUtil.kt

@@ -42,14 +42,14 @@ import org.jetbrains.org.objectweb.asm.Type
 import org.jetbrains.org.objectweb.asm.commons.InstructionAdapter
 
 // todo: extract packages constants too?
-internal val descType = Type.getObjectType("kotlinx/serialization/$SERIAL_DESCRIPTOR_CLASS")
+internal val descType = Type.getObjectType("kotlinx/serialization/descriptors/$SERIAL_DESCRIPTOR_CLASS")
 internal val descImplType = Type.getObjectType("kotlinx/serialization/internal/$SERIAL_DESCRIPTOR_CLASS_IMPL")
 internal val descriptorForEnumsType = Type.getObjectType("kotlinx/serialization/internal/$SERIAL_DESCRIPTOR_FOR_ENUM")
 internal val generatedSerializerType = Type.getObjectType("kotlinx/serialization/internal/${SerialEntityNames.GENERATED_SERIALIZER_CLASS}")
-internal val kOutputType = Type.getObjectType("kotlinx/serialization/$STRUCTURE_ENCODER_CLASS")
-internal val encoderType = Type.getObjectType("kotlinx/serialization/$ENCODER_CLASS")
-internal val decoderType = Type.getObjectType("kotlinx/serialization/$DECODER_CLASS")
-internal val kInputType = Type.getObjectType("kotlinx/serialization/$STRUCTURE_DECODER_CLASS")
+internal val kOutputType = Type.getObjectType("kotlinx/serialization/encoding/$STRUCTURE_ENCODER_CLASS")
+internal val encoderType = Type.getObjectType("kotlinx/serialization/encoding/$ENCODER_CLASS")
+internal val decoderType = Type.getObjectType("kotlinx/serialization/encoding/$DECODER_CLASS")
+internal val kInputType = Type.getObjectType("kotlinx/serialization/encoding/$STRUCTURE_DECODER_CLASS")
 
 
 internal val kSerialSaverType = Type.getObjectType("kotlinx/serialization/$SERIAL_SAVER_CLASS")

plugins/kotlin-serialization/kotlin-serialization-compiler/src/org/jetbrains/kotlinx/serialization/compiler/resolve/NamingConventions.kt

@@ -11,7 +11,11 @@ import org.jetbrains.kotlin.name.Name
 object SerializationPackages {
     internal val packageFqName = FqName("kotlinx.serialization")
     internal val internalPackageFqName = FqName("kotlinx.serialization.internal")
+    internal val encodingPackageFqName = FqName("kotlinx.serialization.encoding")
+    internal val descriptorsPackageFqName = FqName("kotlinx.serialization.descriptors")
     internal val builtinsPackageFqName = FqName("kotlinx.serialization.builtins")
+
+    val allPublicPackages = listOf(packageFqName, encodingPackageFqName, descriptorsPackageFqName, builtinsPackageFqName)
 }
 
 object SerializationAnnotations {
@@ -89,7 +93,7 @@ object SpecialBuiltins {
     const val enumSerializer = "EnumSerializer"
     const val polymorphicSerializer = "PolymorphicSerializer"
     const val sealedSerializer = "SealedClassSerializer"
-    const val contextSerializer = "ContextSerializer"
+    const val contextSerializer = "ContextualSerializer"
     const val nullableSerializer = "NullableSerializer"
 }
 

plugins/kotlin-serialization/kotlin-serialization-compiler/src/org/jetbrains/kotlinx/serialization/compiler/resolve/SearchUtils.kt

@@ -18,6 +18,7 @@ import org.jetbrains.kotlin.resolve.descriptorUtil.module
 import org.jetbrains.kotlin.resolve.lazy.descriptors.LazyAnnotationDescriptor
 import org.jetbrains.kotlin.types.KotlinType
 import org.jetbrains.kotlin.types.KotlinTypeFactory
+import org.jetbrains.kotlin.utils.addToStdlib.firstNotNullResult
 
 internal fun ClassConstructorDescriptor.isSerializationCtor(): Boolean {
     /*kind == CallableMemberDescriptor.Kind.SYNTHESIZED does not work because DeserializedClassConstructorDescriptor loses its kind*/
@@ -72,32 +73,28 @@ internal fun getInternalPackageFqn(classSimpleName: String): FqName =
     SerializationPackages.internalPackageFqName.child(Name.identifier(classSimpleName))
 
 internal fun ModuleDescriptor.getClassFromInternalSerializationPackage(classSimpleName: String) =
-    getFromPackage(SerializationPackages.internalPackageFqName, classSimpleName)
+    requireNotNull(
+        findClassAcrossModuleDependencies(
+            ClassId(
+                SerializationPackages.internalPackageFqName,
+                Name.identifier(classSimpleName)
+            )
+        )
+    ) { "Can't locate class $classSimpleName from package ${SerializationPackages.internalPackageFqName}" }
 
 internal fun getSerializationPackageFqn(classSimpleName: String): FqName =
     SerializationPackages.packageFqName.child(Name.identifier(classSimpleName))
 
 internal fun ModuleDescriptor.getClassFromSerializationPackage(classSimpleName: String) =
-    getFromPackage(SerializationPackages.packageFqName, classSimpleName)
-
-private fun ModuleDescriptor.getFromPackage(packageFqName: FqName, classSimpleName: String) = requireNotNull(
-    findClassAcrossModuleDependencies(
-        ClassId(
-            packageFqName,
+    SerializationPackages.allPublicPackages.firstNotNullResult { pkg ->
+        module.findClassAcrossModuleDependencies(ClassId(
+            pkg,
             Name.identifier(classSimpleName)
-        )
-    )
-) { "Can't locate class $classSimpleName from package $packageFqName" }
+        ))
+    } ?: throw IllegalArgumentException("Can't locate class $classSimpleName")
 
 internal fun ClassDescriptor.getClassFromSerializationPackage(classSimpleName: String) =
-    requireNotNull(
-        module.findClassAcrossModuleDependencies(
-            ClassId(
-                SerializationPackages.packageFqName,
-                Name.identifier(classSimpleName)
-            )
-        )
-    ) { "Can't locate class $classSimpleName" }
+    module.getClassFromSerializationPackage(classSimpleName)
 
 internal fun ClassDescriptor.getClassFromInternalSerializationPackage(classSimpleName: String) =
     module.getClassFromInternalSerializationPackage(classSimpleName)