Introduce support for plugin-defined intrinsics in old JVM backend:

(Old is created first because all intrinsics emit bytecode anyway)

Provide intrinsic for serializer<T>() function so it won't
invoke typeOf() construction and KType->KSerializer conversion
making it fast and truly reflectionless

Add support for recalculating stack size in plugin-defined intrinsics
since it is needed for correct work:
Unify method for recalculating stack size with existing typeOf intrinsic

Add testdata for IR for future intrinsic in IR

plugins/kotlinx-serialization/testData/codegen/Intrinsics.ir.txt

@@ -0,0 +1,465 @@
+public final class Box$$serializer : java/lang/Object, kotlinx/serialization/internal/GeneratedSerializer {
+    private final kotlinx.serialization.internal.PluginGeneratedSerialDescriptor descriptor
+
+    private final kotlinx.serialization.KSerializer typeSerial0
+
+    private void <init>()
+
+    public void <init>(kotlinx.serialization.KSerializer typeSerial0)
+
+    public kotlinx.serialization.KSerializer[] childSerializers()
+
+    public Box deserialize(kotlinx.serialization.encoding.Decoder decoder)
+
+    public java.lang.Object deserialize(kotlinx.serialization.encoding.Decoder decoder)
+
+    public kotlinx.serialization.descriptors.SerialDescriptor getDescriptor()
+
+    private final kotlinx.serialization.KSerializer getTypeSerial0()
+
+    public void serialize(kotlinx.serialization.encoding.Encoder encoder, Box value)
+
+    public void serialize(kotlinx.serialization.encoding.Encoder encoder, java.lang.Object value)
+
+    public kotlinx.serialization.KSerializer[] typeParametersSerializers()
+}
+
+public final class Box$Companion : java/lang/Object {
+    private void <init>()
+
+    public void <init>(kotlin.jvm.internal.DefaultConstructorMarker $constructor_marker)
+
+    private final kotlinx.serialization.descriptors.SerialDescriptor get$cachedDescriptor()
+
+    public final kotlinx.serialization.KSerializer serializer(kotlinx.serialization.KSerializer typeSerial0)
+}
+
+public final class Box : java/lang/Object {
+    private final static kotlinx.serialization.descriptors.SerialDescriptor $cachedDescriptor
+
+    public final static Box$Companion Companion
+
+    private final java.lang.Object boxed
+
+    static void <clinit>()
+
+    public void <init>(java.lang.Object boxed)
+
+    public void <init>(int seen1, java.lang.Object boxed, kotlinx.serialization.internal.SerializationConstructorMarker serializationConstructorMarker)
+
+    public final static kotlinx.serialization.descriptors.SerialDescriptor access$get$cachedDescriptor$cp()
+
+    public final java.lang.Object component1()
+
+    public final Box copy(java.lang.Object boxed)
+
+    public static Box copy$default(Box p0, java.lang.Object p1, int p2, java.lang.Object p3)
+
+    public boolean equals(java.lang.Object other)
+
+    public final java.lang.Object getBoxed()
+
+    public int hashCode()
+
+    public java.lang.String toString()
+
+    public final static void write$Self(Box self, kotlinx.serialization.encoding.CompositeEncoder output, kotlinx.serialization.descriptors.SerialDescriptor serialDesc, kotlinx.serialization.KSerializer typeSerial0)
+}
+
+public final class IntrinsicsKt : java/lang/Object {
+    public final static kotlinx.serialization.KSerializer getBoxSer()
+
+    public final static kotlinx.serialization.KSerializer getSer()
+
+    public final static kotlinx.serialization.KSerializer listSer()
+
+    public final static void test() {
+        LABEL (L0)
+        LINENUMBER (28)
+          ICONST_0
+          ISTORE (0)
+        LABEL (L1)
+          LDC (LSimple;)
+          INVOKESTATIC (kotlin/jvm/internal/Reflection, typeOf, (Ljava/lang/Class;)Lkotlin/reflect/KType;)
+        LABEL (L2)
+        LINENUMBER (50)
+          INVOKESTATIC (kotlinx/serialization/SerializersKt, serializer, (Lkotlin/reflect/KType;)Lkotlinx/serialization/KSerializer;)
+          ASTORE (1)
+        LABEL (L3)
+          ICONST_0
+          ISTORE (2)
+        LABEL (L4)
+        LINENUMBER (51)
+          ALOAD (1)
+          LDC (null cannot be cast to non-null type kotlinx.serialization.KSerializer<T of kotlinx.serialization.internal.Platform_commonKt.cast>)
+          INVOKESTATIC (kotlin/jvm/internal/Intrinsics, checkNotNull, (Ljava/lang/Object;Ljava/lang/String;)V)
+        LABEL (L5)
+        LINENUMBER (50)
+          NOP
+        LABEL (L6)
+        LINENUMBER (29)
+          ICONST_0
+          ISTORE (0)
+        LABEL (L7)
+        LINENUMBER (52)
+          ICONST_0
+          ISTORE (1)
+        LABEL (L8)
+          LDC (LSimple;)
+          INVOKESTATIC (kotlin/jvm/internal/Reflection, typeOf, (Ljava/lang/Class;)Lkotlin/reflect/KType;)
+        LABEL (L9)
+        LINENUMBER (53)
+          INVOKESTATIC (kotlinx/serialization/SerializersKt, serializer, (Lkotlin/reflect/KType;)Lkotlinx/serialization/KSerializer;)
+          ASTORE (2)
+        LABEL (L10)
+          ICONST_0
+          ISTORE (3)
+        LABEL (L11)
+        LINENUMBER (54)
+          ALOAD (2)
+          LDC (null cannot be cast to non-null type kotlinx.serialization.KSerializer<T of kotlinx.serialization.internal.Platform_commonKt.cast>)
+          INVOKESTATIC (kotlin/jvm/internal/Intrinsics, checkNotNull, (Ljava/lang/Object;Ljava/lang/String;)V)
+        LABEL (L12)
+        LINENUMBER (53)
+          NOP
+        LABEL (L13)
+        LINENUMBER (52)
+          NOP
+        LABEL (L14)
+        LINENUMBER (30)
+          ICONST_0
+          ISTORE (0)
+        LABEL (L15)
+        LINENUMBER (55)
+          ICONST_0
+          ISTORE (1)
+        LABEL (L16)
+          LDC (LBox;)
+          GETSTATIC (kotlin/reflect/KTypeProjection, Companion, Lkotlin/reflect/KTypeProjection$Companion;)
+          LDC (LSimple;)
+          INVOKESTATIC (kotlin/jvm/internal/Reflection, typeOf, (Ljava/lang/Class;)Lkotlin/reflect/KType;)
+          INVOKEVIRTUAL (kotlin/reflect/KTypeProjection$Companion, invariant, (Lkotlin/reflect/KType;)Lkotlin/reflect/KTypeProjection;)
+          INVOKESTATIC (kotlin/jvm/internal/Reflection, typeOf, (Ljava/lang/Class;Lkotlin/reflect/KTypeProjection;)Lkotlin/reflect/KType;)
+        LABEL (L17)
+        LINENUMBER (56)
+          INVOKESTATIC (kotlinx/serialization/SerializersKt, serializer, (Lkotlin/reflect/KType;)Lkotlinx/serialization/KSerializer;)
+          ASTORE (2)
+        LABEL (L18)
+          ICONST_0
+          ISTORE (3)
+        LABEL (L19)
+        LINENUMBER (57)
+          ALOAD (2)
+          LDC (null cannot be cast to non-null type kotlinx.serialization.KSerializer<T of kotlinx.serialization.internal.Platform_commonKt.cast>)
+          INVOKESTATIC (kotlin/jvm/internal/Intrinsics, checkNotNull, (Ljava/lang/Object;Ljava/lang/String;)V)
+        LABEL (L20)
+        LINENUMBER (56)
+          NOP
+        LABEL (L21)
+        LINENUMBER (55)
+          NOP
+        LABEL (L22)
+        LINENUMBER (31)
+          ICONST_0
+          ISTORE (0)
+        LABEL (L23)
+        LINENUMBER (58)
+          ICONST_0
+          ISTORE (1)
+        LABEL (L24)
+          LDC (LBox;)
+          GETSTATIC (kotlin/reflect/KTypeProjection, Companion, Lkotlin/reflect/KTypeProjection$Companion;)
+          LDC (LSimple;)
+          INVOKESTATIC (kotlin/jvm/internal/Reflection, typeOf, (Ljava/lang/Class;)Lkotlin/reflect/KType;)
+          INVOKEVIRTUAL (kotlin/reflect/KTypeProjection$Companion, invariant, (Lkotlin/reflect/KType;)Lkotlin/reflect/KTypeProjection;)
+          INVOKESTATIC (kotlin/jvm/internal/Reflection, typeOf, (Ljava/lang/Class;Lkotlin/reflect/KTypeProjection;)Lkotlin/reflect/KType;)
+        LABEL (L25)
+        LINENUMBER (59)
+          INVOKESTATIC (kotlinx/serialization/SerializersKt, serializer, (Lkotlin/reflect/KType;)Lkotlinx/serialization/KSerializer;)
+          ASTORE (2)
+        LABEL (L26)
+          ICONST_0
+          ISTORE (3)
+        LABEL (L27)
+        LINENUMBER (60)
+          ALOAD (2)
+          LDC (null cannot be cast to non-null type kotlinx.serialization.KSerializer<T of kotlinx.serialization.internal.Platform_commonKt.cast>)
+          INVOKESTATIC (kotlin/jvm/internal/Intrinsics, checkNotNull, (Ljava/lang/Object;Ljava/lang/String;)V)
+        LABEL (L28)
+        LINENUMBER (59)
+          NOP
+        LABEL (L29)
+        LINENUMBER (58)
+          NOP
+        LABEL (L30)
+        LINENUMBER (32)
+          ICONST_0
+          ISTORE (0)
+        LABEL (L31)
+        LINENUMBER (61)
+          ICONST_0
+          ISTORE (1)
+        LABEL (L32)
+          LDC (Ljava/util/List;)
+          GETSTATIC (kotlin/reflect/KTypeProjection, Companion, Lkotlin/reflect/KTypeProjection$Companion;)
+          LDC (LSimple;)
+          INVOKESTATIC (kotlin/jvm/internal/Reflection, typeOf, (Ljava/lang/Class;)Lkotlin/reflect/KType;)
+          INVOKEVIRTUAL (kotlin/reflect/KTypeProjection$Companion, invariant, (Lkotlin/reflect/KType;)Lkotlin/reflect/KTypeProjection;)
+          INVOKESTATIC (kotlin/jvm/internal/Reflection, typeOf, (Ljava/lang/Class;Lkotlin/reflect/KTypeProjection;)Lkotlin/reflect/KType;)
+        LABEL (L33)
+        LINENUMBER (62)
+          INVOKESTATIC (kotlinx/serialization/SerializersKt, serializer, (Lkotlin/reflect/KType;)Lkotlinx/serialization/KSerializer;)
+          ASTORE (2)
+        LABEL (L34)
+          ICONST_0
+          ISTORE (3)
+        LABEL (L35)
+        LINENUMBER (63)
+          ALOAD (2)
+          LDC (null cannot be cast to non-null type kotlinx.serialization.KSerializer<T of kotlinx.serialization.internal.Platform_commonKt.cast>)
+          INVOKESTATIC (kotlin/jvm/internal/Intrinsics, checkNotNull, (Ljava/lang/Object;Ljava/lang/String;)V)
+        LABEL (L36)
+        LINENUMBER (62)
+          NOP
+        LABEL (L37)
+        LINENUMBER (61)
+          NOP
+        LABEL (L38)
+        LINENUMBER (34)
+          ICONST_0
+          ISTORE (0)
+        LABEL (L39)
+          LDC (LBox;)
+          GETSTATIC (kotlin/reflect/KTypeProjection, Companion, Lkotlin/reflect/KTypeProjection$Companion;)
+          LDC (Ljava/util/List;)
+          GETSTATIC (kotlin/reflect/KTypeProjection, Companion, Lkotlin/reflect/KTypeProjection$Companion;)
+          LDC (LSimple;)
+          INVOKESTATIC (kotlin/jvm/internal/Reflection, typeOf, (Ljava/lang/Class;)Lkotlin/reflect/KType;)
+          INVOKEVIRTUAL (kotlin/reflect/KTypeProjection$Companion, invariant, (Lkotlin/reflect/KType;)Lkotlin/reflect/KTypeProjection;)
+          INVOKESTATIC (kotlin/jvm/internal/Reflection, typeOf, (Ljava/lang/Class;Lkotlin/reflect/KTypeProjection;)Lkotlin/reflect/KType;)
+          INVOKEVIRTUAL (kotlin/reflect/KTypeProjection$Companion, invariant, (Lkotlin/reflect/KType;)Lkotlin/reflect/KTypeProjection;)
+          INVOKESTATIC (kotlin/jvm/internal/Reflection, typeOf, (Ljava/lang/Class;Lkotlin/reflect/KTypeProjection;)Lkotlin/reflect/KType;)
+        LABEL (L40)
+        LINENUMBER (64)
+          INVOKESTATIC (kotlinx/serialization/SerializersKt, serializer, (Lkotlin/reflect/KType;)Lkotlinx/serialization/KSerializer;)
+          ASTORE (1)
+        LABEL (L41)
+          ICONST_0
+          ISTORE (2)
+        LABEL (L42)
+        LINENUMBER (65)
+          ALOAD (1)
+          LDC (null cannot be cast to non-null type kotlinx.serialization.KSerializer<T of kotlinx.serialization.internal.Platform_commonKt.cast>)
+          INVOKESTATIC (kotlin/jvm/internal/Intrinsics, checkNotNull, (Ljava/lang/Object;Ljava/lang/String;)V)
+        LABEL (L43)
+        LINENUMBER (64)
+          NOP
+        LABEL (L44)
+        LINENUMBER (36)
+          ICONST_0
+          ISTORE (0)
+        LABEL (L45)
+        LINENUMBER (66)
+          ICONST_0
+          ISTORE (1)
+        LABEL (L46)
+          LDC (Ljava/util/List;)
+          GETSTATIC (kotlin/reflect/KTypeProjection, Companion, Lkotlin/reflect/KTypeProjection$Companion;)
+          LDC (LBox;)
+          GETSTATIC (kotlin/reflect/KTypeProjection, Companion, Lkotlin/reflect/KTypeProjection$Companion;)
+          LDC (Ljava/util/List;)
+          GETSTATIC (kotlin/reflect/KTypeProjection, Companion, Lkotlin/reflect/KTypeProjection$Companion;)
+          LDC (LSimple;)
+          INVOKESTATIC (kotlin/jvm/internal/Reflection, typeOf, (Ljava/lang/Class;)Lkotlin/reflect/KType;)
+          INVOKEVIRTUAL (kotlin/reflect/KTypeProjection$Companion, invariant, (Lkotlin/reflect/KType;)Lkotlin/reflect/KTypeProjection;)
+          INVOKESTATIC (kotlin/jvm/internal/Reflection, typeOf, (Ljava/lang/Class;Lkotlin/reflect/KTypeProjection;)Lkotlin/reflect/KType;)
+          INVOKEVIRTUAL (kotlin/reflect/KTypeProjection$Companion, invariant, (Lkotlin/reflect/KType;)Lkotlin/reflect/KTypeProjection;)
+          INVOKESTATIC (kotlin/jvm/internal/Reflection, typeOf, (Ljava/lang/Class;Lkotlin/reflect/KTypeProjection;)Lkotlin/reflect/KType;)
+          INVOKEVIRTUAL (kotlin/reflect/KTypeProjection$Companion, invariant, (Lkotlin/reflect/KType;)Lkotlin/reflect/KTypeProjection;)
+          INVOKESTATIC (kotlin/jvm/internal/Reflection, typeOf, (Ljava/lang/Class;Lkotlin/reflect/KTypeProjection;)Lkotlin/reflect/KType;)
+        LABEL (L47)
+        LINENUMBER (67)
+          INVOKESTATIC (kotlinx/serialization/SerializersKt, serializer, (Lkotlin/reflect/KType;)Lkotlinx/serialization/KSerializer;)
+          ASTORE (2)
+        LABEL (L48)
+          ICONST_0
+          ISTORE (3)
+        LABEL (L49)
+        LINENUMBER (68)
+          ALOAD (2)
+          LDC (null cannot be cast to non-null type kotlinx.serialization.KSerializer<T of kotlinx.serialization.internal.Platform_commonKt.cast>)
+          INVOKESTATIC (kotlin/jvm/internal/Intrinsics, checkNotNull, (Ljava/lang/Object;Ljava/lang/String;)V)
+        LABEL (L50)
+        LINENUMBER (67)
+          NOP
+        LABEL (L51)
+        LINENUMBER (66)
+          NOP
+        LABEL (L52)
+        LINENUMBER (38)
+          ICONST_0
+          ISTORE (0)
+        LABEL (L53)
+          GETSTATIC (java/lang/Integer, TYPE, Ljava/lang/Class;)
+          INVOKESTATIC (kotlin/jvm/internal/Reflection, typeOf, (Ljava/lang/Class;)Lkotlin/reflect/KType;)
+        LABEL (L54)
+        LINENUMBER (69)
+          INVOKESTATIC (kotlinx/serialization/SerializersKt, serializer, (Lkotlin/reflect/KType;)Lkotlinx/serialization/KSerializer;)
+          ASTORE (1)
+        LABEL (L55)
+          ICONST_0
+          ISTORE (2)
+        LABEL (L56)
+        LINENUMBER (70)
+          ALOAD (1)
+          LDC (null cannot be cast to non-null type kotlinx.serialization.KSerializer<T of kotlinx.serialization.internal.Platform_commonKt.cast>)
+          INVOKESTATIC (kotlin/jvm/internal/Intrinsics, checkNotNull, (Ljava/lang/Object;Ljava/lang/String;)V)
+        LABEL (L57)
+        LINENUMBER (69)
+          NOP
+        LABEL (L58)
+        LINENUMBER (40)
+          ICONST_0
+          ISTORE (0)
+        LABEL (L59)
+          LDC (LSerializableObject;)
+          INVOKESTATIC (kotlin/jvm/internal/Reflection, typeOf, (Ljava/lang/Class;)Lkotlin/reflect/KType;)
+        LABEL (L60)
+        LINENUMBER (71)
+          INVOKESTATIC (kotlinx/serialization/SerializersKt, serializer, (Lkotlin/reflect/KType;)Lkotlinx/serialization/KSerializer;)
+          ASTORE (1)
+        LABEL (L61)
+          ICONST_0
+          ISTORE (2)
+        LABEL (L62)
+        LINENUMBER (72)
+          ALOAD (1)
+          LDC (null cannot be cast to non-null type kotlinx.serialization.KSerializer<T of kotlinx.serialization.internal.Platform_commonKt.cast>)
+          INVOKESTATIC (kotlin/jvm/internal/Intrinsics, checkNotNull, (Ljava/lang/Object;Ljava/lang/String;)V)
+        LABEL (L63)
+        LINENUMBER (71)
+          NOP
+        LABEL (L64)
+        LINENUMBER (42)
+          ICONST_0
+          ISTORE (0)
+        LABEL (L65)
+        LINENUMBER (73)
+          ICONST_0
+          ISTORE (1)
+        LABEL (L66)
+          LDC (Ljava/util/List;)
+          GETSTATIC (kotlin/reflect/KTypeProjection, Companion, Lkotlin/reflect/KTypeProjection$Companion;)
+          LDC (Ljava/util/List;)
+          GETSTATIC (kotlin/reflect/KTypeProjection, Companion, Lkotlin/reflect/KTypeProjection$Companion;)
+          LDC (LBox;)
+          GETSTATIC (kotlin/reflect/KTypeProjection, Companion, Lkotlin/reflect/KTypeProjection$Companion;)
+          GETSTATIC (java/lang/Integer, TYPE, Ljava/lang/Class;)
+          INVOKESTATIC (kotlin/jvm/internal/Reflection, typeOf, (Ljava/lang/Class;)Lkotlin/reflect/KType;)
+          INVOKEVIRTUAL (kotlin/reflect/KTypeProjection$Companion, invariant, (Lkotlin/reflect/KType;)Lkotlin/reflect/KTypeProjection;)
+          INVOKESTATIC (kotlin/jvm/internal/Reflection, typeOf, (Ljava/lang/Class;Lkotlin/reflect/KTypeProjection;)Lkotlin/reflect/KType;)
+          INVOKEVIRTUAL (kotlin/reflect/KTypeProjection$Companion, invariant, (Lkotlin/reflect/KType;)Lkotlin/reflect/KTypeProjection;)
+          INVOKESTATIC (kotlin/jvm/internal/Reflection, typeOf, (Ljava/lang/Class;Lkotlin/reflect/KTypeProjection;)Lkotlin/reflect/KType;)
+          INVOKEVIRTUAL (kotlin/reflect/KTypeProjection$Companion, invariant, (Lkotlin/reflect/KType;)Lkotlin/reflect/KTypeProjection;)
+          INVOKESTATIC (kotlin/jvm/internal/Reflection, typeOf, (Ljava/lang/Class;Lkotlin/reflect/KTypeProjection;)Lkotlin/reflect/KType;)
+        LABEL (L67)
+        LINENUMBER (74)
+          INVOKESTATIC (kotlinx/serialization/SerializersKt, serializer, (Lkotlin/reflect/KType;)Lkotlinx/serialization/KSerializer;)
+          ASTORE (2)
+        LABEL (L68)
+          ICONST_0
+          ISTORE (3)
+        LABEL (L69)
+        LINENUMBER (75)
+          ALOAD (2)
+          LDC (null cannot be cast to non-null type kotlinx.serialization.KSerializer<T of kotlinx.serialization.internal.Platform_commonKt.cast>)
+          INVOKESTATIC (kotlin/jvm/internal/Intrinsics, checkNotNull, (Ljava/lang/Object;Ljava/lang/String;)V)
+        LABEL (L70)
+        LINENUMBER (74)
+          NOP
+        LABEL (L71)
+        LINENUMBER (73)
+          NOP
+        LABEL (L72)
+        LINENUMBER (43)
+          RETURN
+    }
+}
+
+final class SerializableObject$$cachedSerializer$delegate$1 : kotlin/jvm/internal/Lambda, kotlin/jvm/functions/Function0 {
+    public final static SerializableObject$$cachedSerializer$delegate$1 INSTANCE
+
+    static void <clinit>()
+
+    void <init>()
+
+    public final kotlinx.serialization.KSerializer invoke()
+
+    public java.lang.Object invoke()
+}
+
+public final class SerializableObject : java/lang/Object {
+    private final static kotlin.Lazy $cachedSerializer$delegate
+
+    public final static SerializableObject INSTANCE
+
+    static void <clinit>()
+
+    private void <init>()
+
+    private final kotlin.Lazy get$cachedSerializer$delegate()
+
+    public final kotlinx.serialization.KSerializer serializer()
+}
+
+public final class Simple$$serializer : java/lang/Object, kotlinx/serialization/internal/GeneratedSerializer {
+    public final static Simple$$serializer INSTANCE
+
+    private final static kotlinx.serialization.internal.PluginGeneratedSerialDescriptor descriptor
+
+    static void <clinit>()
+
+    private void <init>()
+
+    public kotlinx.serialization.KSerializer[] childSerializers()
+
+    public Simple deserialize(kotlinx.serialization.encoding.Decoder decoder)
+
+    public java.lang.Object deserialize(kotlinx.serialization.encoding.Decoder decoder)
+
+    public kotlinx.serialization.descriptors.SerialDescriptor getDescriptor()
+
+    public void serialize(kotlinx.serialization.encoding.Encoder encoder, Simple value)
+
+    public void serialize(kotlinx.serialization.encoding.Encoder encoder, java.lang.Object value)
+
+    public kotlinx.serialization.KSerializer[] typeParametersSerializers()
+}
+
+public final class Simple$Companion : java/lang/Object {
+    private void <init>()
+
+    public void <init>(kotlin.jvm.internal.DefaultConstructorMarker $constructor_marker)
+
+    public final kotlinx.serialization.KSerializer serializer()
+}
+
+public final class Simple : java/lang/Object {
+    public final static Simple$Companion Companion
+
+    private final java.lang.String firstName
+
+    private final java.lang.String lastName
+
+    static void <clinit>()
+
+    public void <init>(java.lang.String firstName, java.lang.String lastName)
+
+    public void <init>(int seen1, java.lang.String firstName, java.lang.String lastName, kotlinx.serialization.internal.SerializationConstructorMarker serializationConstructorMarker)
+
+    public final java.lang.String getFirstName()
+
+    public final java.lang.String getLastName()
+
+    public final static void write$Self(Simple self, kotlinx.serialization.encoding.CompositeEncoder output, kotlinx.serialization.descriptors.SerialDescriptor serialDesc)
+}

plugins/kotlinx-serialization/testData/codegen/Intrinsics.kt

@@ -0,0 +1,43 @@
+// CURIOUS_ABOUT test
+// WITH_STDLIB
+
+import kotlinx.serialization.*
+
+@Serializable
+class Simple(val firstName: String, val lastName: String)
+
+@Serializable
+data class Box<out T>(val boxed: T)
+
+@Serializable
+object SerializableObject {}
+
+inline fun <reified T: Any> getSer(): KSerializer<T> {
+    return serializer<T>()
+}
+
+inline fun <reified T: Any> getBoxSer(): KSerializer<Box<T>> {
+    return serializer<Box<T>>()
+}
+
+inline fun <reified T: Any> listSer(): KSerializer<List<T>> {
+    return serializer<List<T>>()
+}
+
+fun test() {
+    serializer<Simple>()
+    getSer<Simple>()
+    getSer<Box<Simple>>()
+    getBoxSer<Simple>()
+    listSer<Simple>()
+
+    serializer<Box<List<Simple>>>()
+
+    listSer<Box<List<Simple>>>()
+
+    serializer<Int>()
+
+    serializer<SerializableObject>()
+
+    listSer<List<Box<Int>>>()
+}

plugins/kotlinx-serialization/testData/codegen/Intrinsics.txt

@@ -0,0 +1,260 @@
+public final class Box$$serializer : java/lang/Object, kotlinx/serialization/internal/GeneratedSerializer {
+    private final kotlinx.serialization.descriptors.SerialDescriptor $$serialDesc
+
+    private kotlinx.serialization.KSerializer typeSerial0
+
+    private void <init>()
+
+    public void <init>(kotlinx.serialization.KSerializer typeSerial0)
+
+    public kotlinx.serialization.KSerializer[] childSerializers()
+
+    public Box deserialize(kotlinx.serialization.encoding.Decoder decoder)
+
+    public java.lang.Object deserialize(kotlinx.serialization.encoding.Decoder p0)
+
+    public kotlinx.serialization.descriptors.SerialDescriptor getDescriptor()
+
+    public void serialize(kotlinx.serialization.encoding.Encoder encoder, Box value)
+
+    public void serialize(kotlinx.serialization.encoding.Encoder p0, java.lang.Object p1)
+
+    public kotlinx.serialization.KSerializer[] typeParametersSerializers()
+}
+
+public final class Box$Companion : java/lang/Object {
+    private void <init>()
+
+    public void <init>(kotlin.jvm.internal.DefaultConstructorMarker $constructor_marker)
+
+    public final kotlinx.serialization.KSerializer serializer(kotlinx.serialization.KSerializer typeSerial0)
+}
+
+public final class Box : java/lang/Object {
+    private final static kotlinx.serialization.descriptors.SerialDescriptor $cachedDescriptor
+
+    public final static Box$Companion Companion
+
+    private final java.lang.Object boxed
+
+    static void <clinit>()
+
+    public void <init>(java.lang.Object boxed)
+
+    public void <init>(int seen1, java.lang.Object boxed, kotlinx.serialization.internal.SerializationConstructorMarker serializationConstructorMarker)
+
+    public final java.lang.Object component1()
+
+    public final Box copy(java.lang.Object boxed)
+
+    public static Box copy$default(Box p0, java.lang.Object p1, int p2, java.lang.Object p3)
+
+    public boolean equals(java.lang.Object p0)
+
+    public final java.lang.Object getBoxed()
+
+    public int hashCode()
+
+    public java.lang.String toString()
+
+    public final static void write$Self(Box self, kotlinx.serialization.encoding.CompositeEncoder output, kotlinx.serialization.descriptors.SerialDescriptor serialDesc, kotlinx.serialization.KSerializer typeSerial0)
+}
+
+public final class IntrinsicsKt : java/lang/Object {
+    public final static kotlinx.serialization.KSerializer getBoxSer()
+
+    public final static kotlinx.serialization.KSerializer getSer()
+
+    public final static kotlinx.serialization.KSerializer listSer()
+
+    public final static void test() {
+        LABEL (L0)
+        LINENUMBER (28)
+          GETSTATIC (Simple, Companion, LSimple$Companion;)
+          INVOKEVIRTUAL (Simple$Companion, serializer, ()Lkotlinx/serialization/KSerializer;)
+          POP
+        LABEL (L1)
+        LINENUMBER (29)
+          ICONST_0
+          ISTORE (0)
+        LABEL (L2)
+        LINENUMBER (44)
+          GETSTATIC (Simple, Companion, LSimple$Companion;)
+          INVOKEVIRTUAL (Simple$Companion, serializer, ()Lkotlinx/serialization/KSerializer;)
+        LABEL (L3)
+          POP
+        LABEL (L4)
+        LINENUMBER (30)
+          ICONST_0
+          ISTORE (0)
+        LABEL (L5)
+        LINENUMBER (45)
+          GETSTATIC (Box, Companion, LBox$Companion;)
+          GETSTATIC (Simple, Companion, LSimple$Companion;)
+          INVOKEVIRTUAL (Simple$Companion, serializer, ()Lkotlinx/serialization/KSerializer;)
+          INVOKEVIRTUAL (Box$Companion, serializer, (Lkotlinx/serialization/KSerializer;)Lkotlinx/serialization/KSerializer;)
+        LABEL (L6)
+          POP
+        LABEL (L7)
+        LINENUMBER (31)
+          ICONST_0
+          ISTORE (0)
+        LABEL (L8)
+        LINENUMBER (46)
+          GETSTATIC (Box, Companion, LBox$Companion;)
+          GETSTATIC (Simple, Companion, LSimple$Companion;)
+          INVOKEVIRTUAL (Simple$Companion, serializer, ()Lkotlinx/serialization/KSerializer;)
+          INVOKEVIRTUAL (Box$Companion, serializer, (Lkotlinx/serialization/KSerializer;)Lkotlinx/serialization/KSerializer;)
+        LABEL (L9)
+          POP
+        LABEL (L10)
+        LINENUMBER (32)
+          ICONST_0
+          ISTORE (0)
+        LABEL (L11)
+        LINENUMBER (47)
+          NEW (kotlinx/serialization/internal/ArrayListSerializer)
+          DUP
+          GETSTATIC (Simple, Companion, LSimple$Companion;)
+          INVOKEVIRTUAL (Simple$Companion, serializer, ()Lkotlinx/serialization/KSerializer;)
+          INVOKESPECIAL (kotlinx/serialization/internal/ArrayListSerializer, <init>, (Lkotlinx/serialization/KSerializer;)V)
+        LABEL (L12)
+          POP
+        LABEL (L13)
+        LINENUMBER (34)
+          GETSTATIC (Box, Companion, LBox$Companion;)
+          NEW (kotlinx/serialization/internal/ArrayListSerializer)
+          DUP
+          GETSTATIC (Simple$$serializer, INSTANCE, LSimple$$serializer;)
+          CHECKCAST (kotlinx/serialization/KSerializer)
+          INVOKESPECIAL (kotlinx/serialization/internal/ArrayListSerializer, <init>, (Lkotlinx/serialization/KSerializer;)V)
+          INVOKEVIRTUAL (Box$Companion, serializer, (Lkotlinx/serialization/KSerializer;)Lkotlinx/serialization/KSerializer;)
+          POP
+        LABEL (L14)
+        LINENUMBER (36)
+          ICONST_0
+          ISTORE (0)
+        LABEL (L15)
+        LINENUMBER (48)
+          NEW (kotlinx/serialization/internal/ArrayListSerializer)
+          DUP
+          GETSTATIC (Box, Companion, LBox$Companion;)
+          NEW (kotlinx/serialization/internal/ArrayListSerializer)
+          DUP
+          GETSTATIC (Simple$$serializer, INSTANCE, LSimple$$serializer;)
+          CHECKCAST (kotlinx/serialization/KSerializer)
+          INVOKESPECIAL (kotlinx/serialization/internal/ArrayListSerializer, <init>, (Lkotlinx/serialization/KSerializer;)V)
+          INVOKEVIRTUAL (Box$Companion, serializer, (Lkotlinx/serialization/KSerializer;)Lkotlinx/serialization/KSerializer;)
+          INVOKESPECIAL (kotlinx/serialization/internal/ArrayListSerializer, <init>, (Lkotlinx/serialization/KSerializer;)V)
+        LABEL (L16)
+          POP
+        LABEL (L17)
+        LINENUMBER (38)
+          GETSTATIC (kotlinx/serialization/internal/IntSerializer, INSTANCE, Lkotlinx/serialization/internal/IntSerializer;)
+          CHECKCAST (kotlinx/serialization/KSerializer)
+          POP
+        LABEL (L18)
+        LINENUMBER (40)
+          GETSTATIC (SerializableObject, INSTANCE, LSerializableObject;)
+          INVOKEVIRTUAL (SerializableObject, serializer, ()Lkotlinx/serialization/KSerializer;)
+          POP
+        LABEL (L19)
+        LINENUMBER (42)
+          ICONST_0
+          ISTORE (0)
+        LABEL (L20)
+        LINENUMBER (49)
+          NEW (kotlinx/serialization/internal/ArrayListSerializer)
+          DUP
+          NEW (kotlinx/serialization/internal/ArrayListSerializer)
+          DUP
+          NEW (Box$$serializer)
+          DUP
+          GETSTATIC (kotlinx/serialization/internal/IntSerializer, INSTANCE, Lkotlinx/serialization/internal/IntSerializer;)
+          CHECKCAST (kotlinx/serialization/KSerializer)
+          INVOKESPECIAL (Box$$serializer, <init>, (Lkotlinx/serialization/KSerializer;)V)
+          INVOKESPECIAL (kotlinx/serialization/internal/ArrayListSerializer, <init>, (Lkotlinx/serialization/KSerializer;)V)
+          INVOKESPECIAL (kotlinx/serialization/internal/ArrayListSerializer, <init>, (Lkotlinx/serialization/KSerializer;)V)
+        LABEL (L21)
+          POP
+        LABEL (L22)
+        LINENUMBER (43)
+          RETURN
+    }
+}
+
+final class SerializableObject$serializer$1 : kotlin/jvm/internal/Lambda, kotlin/jvm/functions/Function0 {
+    public final static SerializableObject$serializer$1 INSTANCE
+
+    static void <clinit>()
+
+    public void <init>()
+
+    public final kotlinx.serialization.KSerializer invoke()
+
+    public final java.lang.Object invoke()
+}
+
+public final class SerializableObject : java/lang/Object {
+    private final static kotlin.Lazy $cachedSerializer$delegate
+
+    public final static SerializableObject INSTANCE
+
+    static void <clinit>()
+
+    private void <init>()
+
+    public final kotlinx.serialization.KSerializer serializer()
+}
+
+public final class Simple$$serializer : java/lang/Object, kotlinx/serialization/internal/GeneratedSerializer {
+    private final static kotlinx.serialization.descriptors.SerialDescriptor $$serialDesc
+
+    public final static Simple$$serializer INSTANCE
+
+    static void <clinit>()
+
+    private void <init>()
+
+    public kotlinx.serialization.KSerializer[] childSerializers()
+
+    public Simple deserialize(kotlinx.serialization.encoding.Decoder decoder)
+
+    public java.lang.Object deserialize(kotlinx.serialization.encoding.Decoder p0)
+
+    public kotlinx.serialization.descriptors.SerialDescriptor getDescriptor()
+
+    public void serialize(kotlinx.serialization.encoding.Encoder encoder, Simple value)
+
+    public void serialize(kotlinx.serialization.encoding.Encoder p0, java.lang.Object p1)
+
+    public kotlinx.serialization.KSerializer[] typeParametersSerializers()
+}
+
+public final class Simple$Companion : java/lang/Object {
+    private void <init>()
+
+    public void <init>(kotlin.jvm.internal.DefaultConstructorMarker $constructor_marker)
+
+    public final kotlinx.serialization.KSerializer serializer()
+}
+
+public final class Simple : java/lang/Object {
+    public final static Simple$Companion Companion
+
+    private final java.lang.String firstName
+
+    private final java.lang.String lastName
+
+    static void <clinit>()
+
+    public void <init>(java.lang.String firstName, java.lang.String lastName)
+
+    public void <init>(int seen1, java.lang.String firstName, java.lang.String lastName, kotlinx.serialization.internal.SerializationConstructorMarker serializationConstructorMarker)
+
+    public final java.lang.String getFirstName()
+
+    public final java.lang.String getLastName()
+
+    public final static void write$Self(Simple self, kotlinx.serialization.encoding.CompositeEncoder output, kotlinx.serialization.descriptors.SerialDescriptor serialDesc)
+}