psi2ir: fix nullability assertion generation for platform types

Incorporate PR from Steven Schäfer into IrType-based implicit cast
insertion (commit 17b925636e8717e7648c5d7b792c6ab4d18f776d).

NB this still uses originalKotlinType to determine if the type was
nullability flexible. It is somewhat error-prone and something we want
to get rid of. However, it boils down to some design questions related
to implicit null checks in Kotlin - e.g., it might be Ok to just treat
nullability flexible type `T!` as `T?` in IR, generate null checks for
all usages of type `T?` where a non-null type is expected, and later
eliminate the null checks that are redundant according to the (quite
conservative) criterion in the redundant null check elimination.

compiler/fir/fir2ir/tests/org/jetbrains/kotlin/fir/Fir2IrTextTestGenerated.java

@@ -1606,6 +1606,11 @@ public class Fir2IrTextTestGenerated extends AbstractFir2IrTextTest {
             KotlinTestUtils.assertAllTestsPresentByMetadata(this.getClass(), new File("compiler/testData/ir/irText/types"), Pattern.compile("^(.+)\\.kt$"), TargetBackend.ANY, true);
         }
 
+        @TestMetadata("explicitEqualsAndCompareToCallsOnPlatformTypeReceiver.kt")
+        public void testExplicitEqualsAndCompareToCallsOnPlatformTypeReceiver() throws Exception {
+            runTest("compiler/testData/ir/irText/types/explicitEqualsAndCompareToCallsOnPlatformTypeReceiver.kt");
+        }
+
         @TestMetadata("intersectionType1_NI.kt")
         public void testIntersectionType1_NI() throws Exception {
             runTest("compiler/testData/ir/irText/types/intersectionType1_NI.kt");
@@ -1640,5 +1645,10 @@ public class Fir2IrTextTestGenerated extends AbstractFir2IrTextTest {
         public void testLocalVariableOfIntersectionType_NI() throws Exception {
             runTest("compiler/testData/ir/irText/types/localVariableOfIntersectionType_NI.kt");
         }
+
+        @TestMetadata("nullabilityAssertionOnExtensionReceiver.kt")
+        public void testNullabilityAssertionOnExtensionReceiver() throws Exception {
+            runTest("compiler/testData/ir/irText/types/nullabilityAssertionOnExtensionReceiver.kt");
+        }
     }
 }

compiler/ir/ir.psi2ir/src/org/jetbrains/kotlin/psi2ir/transformations/InsertImplicitCasts.kt

@@ -26,6 +26,7 @@ import org.jetbrains.kotlin.ir.expressions.impl.IrTypeOperatorCallImpl
 import org.jetbrains.kotlin.ir.symbols.IrConstructorSymbol
 import org.jetbrains.kotlin.ir.symbols.IrTypeParameterSymbol
 import org.jetbrains.kotlin.ir.types.*
+import org.jetbrains.kotlin.ir.types.impl.makeTypeIntersection
 import org.jetbrains.kotlin.ir.types.impl.makeTypeProjection
 import org.jetbrains.kotlin.ir.types.impl.originalKotlinType
 import org.jetbrains.kotlin.ir.util.TypeTranslator
@@ -37,7 +38,6 @@ import org.jetbrains.kotlin.psi2ir.generators.GeneratorExtensions
 import org.jetbrains.kotlin.types.KotlinType
 import org.jetbrains.kotlin.types.isDynamic
 import org.jetbrains.kotlin.types.isNullabilityFlexible
-import org.jetbrains.kotlin.types.typeUtil.makeNotNullable
 
 fun insertImplicitCasts(element: IrElement, context: GeneratorContext) {
     element.transformChildren(
@@ -111,10 +111,12 @@ open class InsertImplicitCasts(
             val dTypeParameters = getDeclarationSideTypeParameters(declaration)
             val cTypeParameters = getTypeSideTypeParameters(declaration)
             val typeArguments = getTypeArguments(expression, dTypeParameters)
-            val dispatchReceiver = declaration.dispatchReceiverParameter
-            val extensionReceiver = declaration.extensionReceiverParameter
-            this.dispatchReceiver = this.dispatchReceiver?.cast(dispatchReceiver?.type?.substitute(dTypeParameters + cTypeParameters, typeArguments))
-            this.extensionReceiver = this.extensionReceiver?.cast(extensionReceiver?.type?.substitute(dTypeParameters + cTypeParameters, typeArguments))
+            dispatchReceiver = dispatchReceiver?.cast(
+                declaration.dispatchReceiverParameter?.type?.substitute(dTypeParameters + cTypeParameters, typeArguments)
+            )
+            extensionReceiver = extensionReceiver?.cast(
+                declaration.extensionReceiverParameter?.type?.substitute(dTypeParameters + cTypeParameters, typeArguments)
+            )
         }
     }
 
@@ -123,8 +125,12 @@ open class InsertImplicitCasts(
         val dTypeParameters = getDeclarationSideTypeParameters(declaration)
         val cTypeParameters = getTypeSideTypeParameters(declaration)
         val typeArguments = getTypeArguments(this, dTypeParameters)
-        dispatchReceiver = dispatchReceiver?.cast(declaration.dispatchReceiverParameter?.type?.substitute(dTypeParameters + cTypeParameters, typeArguments))
-        extensionReceiver = extensionReceiver?.cast(declaration.extensionReceiverParameter?.type?.substitute(dTypeParameters + cTypeParameters, typeArguments))
+        dispatchReceiver = dispatchReceiver?.cast(
+            declaration.dispatchReceiverParameter?.type?.substitute(dTypeParameters + cTypeParameters, typeArguments)
+        )
+        extensionReceiver = extensionReceiver?.cast(
+            declaration.extensionReceiverParameter?.type?.substitute(dTypeParameters + cTypeParameters, typeArguments)
+        )
     }
 
     override fun visitMemberAccess(expression: IrMemberAccessExpression): IrExpression =
@@ -314,7 +320,7 @@ open class InsertImplicitCasts(
     }
 
     private fun IrExpression.implicitNonNull(valueType: IrType, expectedType: IrType): IrExpression {
-        val notNullValueType = valueType.makeNotNull()
+        val notNullValueType = valueType.getRepresentableUpperBound().makeNotNull()
         return implicitCast(notNullValueType, IrTypeOperator.IMPLICIT_NOTNULL).cast(expectedType)
     }
 
@@ -352,9 +358,13 @@ open class InsertImplicitCasts(
 
     private fun IrType.isBuiltInIntegerType(): Boolean =
         isByte() || isShort() || isInt() || isLong() ||
-                isUByte() ||
-                isUShort() ||
-                isUInt() ||
-                isULong()
+                isUByte() || isUShort() || isUInt() || isULong()
+
+    private fun IrType.getRepresentableUpperBound(): IrType {
+        if (this !is IrSimpleType) return this
+        val classifier = this.classifier as? IrTypeParameterSymbol ?: return this
+        val superTypes = classifier.owner.superTypes
+        return makeTypeIntersection(superTypes)
+    }
 }
 

compiler/ir/ir.tree/src/org/jetbrains/kotlin/ir/util/TypeTranslator.kt

@@ -57,11 +57,11 @@ class TypeTranslator(
         typeParametersResolver.resolveScopedTypeParameter(typeParameterDescriptor)
             ?: symbolTable.referenceTypeParameter(typeParameterDescriptor)
 
-    fun translateType(ktType: KotlinType): IrType =
-        translateType(ktType, Variance.INVARIANT).type
+    fun translateType(kotlinType: KotlinType): IrType =
+        translateType(kotlinType, kotlinType, Variance.INVARIANT).type
 
-    private fun translateType(ktType: KotlinType, variance: Variance): IrTypeProjection {
-        val approximatedType = LegacyTypeApproximation().approximate(ktType)
+    private fun translateType(originalKotlinType: KotlinType, kotlinType: KotlinType, variance: Variance): IrTypeProjection {
+        val approximatedType = LegacyTypeApproximation().approximate(kotlinType)
 
         when {
             approximatedType.isError ->
@@ -69,7 +69,7 @@ class TypeTranslator(
             approximatedType.isDynamic() ->
                 return IrDynamicTypeImpl(approximatedType, translateTypeAnnotations(approximatedType.annotations), variance)
             approximatedType.isFlexible() ->
-                return translateType(approximatedType.upperIfFlexible(), variance)
+                return translateType(originalKotlinType, approximatedType.upperIfFlexible(), variance)
         }
 
         val ktTypeConstructor = approximatedType.constructor
@@ -77,7 +77,7 @@ class TypeTranslator(
             ?: throw AssertionError("No descriptor for type $approximatedType")
 
         return IrSimpleTypeBuilder().apply {
-            kotlinType = approximatedType
+            this.kotlinType = originalKotlinType
             hasQuestionMark = approximatedType.isMarkedNullable
             this.variance = variance
             when (ktTypeDescriptor) {
@@ -140,6 +140,6 @@ class TypeTranslator(
             if (it.isStarProjection)
                 IrStarProjectionImpl
             else
-                translateType(it.type, it.projectionKind)
+                translateType(it.type, it.type, it.projectionKind)
         }
 }

compiler/testData/ir/irText/expressions/coercionToUnit.txt

@@ -36,7 +36,8 @@ FILE fqName:<root> fileName:/coercionToUnit.kt
             BRANCH
               if: CONST Boolean type=kotlin.Boolean value=true
               then: CALL 'public open fun println (x: kotlin.String?): kotlin.Unit declared in java.io.PrintStream' type=kotlin.Unit origin=null
-                $this: GET_VAR 'val tmp0_safe_receiver: java.io.PrintStream? [val] declared in <root>.test3' type=java.io.PrintStream? origin=null
+                $this: TYPE_OP type=java.io.PrintStream origin=IMPLICIT_NOTNULL typeOperand=java.io.PrintStream
+                  GET_VAR 'val tmp0_safe_receiver: java.io.PrintStream? [val] declared in <root>.test3' type=java.io.PrintStream? origin=null
                 x: CONST String type=kotlin.String value="Hello,"
       TYPE_OP type=kotlin.Unit origin=IMPLICIT_COERCION_TO_UNIT typeOperand=kotlin.Unit
         BLOCK type=kotlin.Unit? origin=SAFE_CALL
@@ -51,5 +52,6 @@ FILE fqName:<root> fileName:/coercionToUnit.kt
             BRANCH
               if: CONST Boolean type=kotlin.Boolean value=true
               then: CALL 'public open fun println (x: kotlin.String?): kotlin.Unit declared in java.io.PrintStream' type=kotlin.Unit origin=null
-                $this: GET_VAR 'val tmp1_safe_receiver: java.io.PrintStream? [val] declared in <root>.test3' type=java.io.PrintStream? origin=null
+                $this: TYPE_OP type=java.io.PrintStream origin=IMPLICIT_NOTNULL typeOperand=java.io.PrintStream
+                  GET_VAR 'val tmp1_safe_receiver: java.io.PrintStream? [val] declared in <root>.test3' type=java.io.PrintStream? origin=null
                 x: CONST String type=kotlin.String value="world!"

compiler/testData/ir/irText/expressions/implicitCastOnPlatformType.txt

@@ -2,5 +2,6 @@ FILE fqName:<root> fileName:/implicitCastOnPlatformType.kt
   FUN name:test visibility:public modality:FINAL <> () returnType:kotlin.String 
     BLOCK_BODY
       RETURN type=kotlin.Nothing from='public final fun test (): kotlin.String declared in <root>'
-        CALL 'public open fun getProperty (key: kotlin.String?): kotlin.String? declared in java.lang.System' type=kotlin.String? origin=null
-          key: CONST String type=kotlin.String value="test"
+        TYPE_OP type=kotlin.String origin=IMPLICIT_NOTNULL typeOperand=kotlin.String
+          CALL 'public open fun getProperty (key: kotlin.String?): kotlin.String? declared in java.lang.System' type=kotlin.String? origin=null
+            key: CONST String type=kotlin.String value="test"

compiler/testData/ir/irText/expressions/jvmStaticFieldReference.txt

@@ -2,14 +2,16 @@ FILE fqName:<root> fileName:/jvmStaticFieldReference.kt
   FUN name:testFun visibility:public modality:FINAL <> () returnType:kotlin.Unit 
     BLOCK_BODY
       CALL 'public open fun println (x: kotlin.String?): kotlin.Unit declared in java.io.PrintStream' type=kotlin.Unit origin=null
-        $this: GET_FIELD 'FIELD IR_EXTERNAL_JAVA_DECLARATION_STUB name:out type:java.io.PrintStream? visibility:public [final,static] ' type=java.io.PrintStream? origin=GET_PROPERTY
+        $this: TYPE_OP type=java.io.PrintStream origin=IMPLICIT_NOTNULL typeOperand=java.io.PrintStream
+          GET_FIELD 'FIELD IR_EXTERNAL_JAVA_DECLARATION_STUB name:out type:java.io.PrintStream? visibility:public [final,static] ' type=java.io.PrintStream? origin=GET_PROPERTY
         x: CONST String type=kotlin.String value="testFun"
   PROPERTY name:testProp visibility:public modality:FINAL [var] 
     FUN name:<get-testProp> visibility:public modality:FINAL <> () returnType:kotlin.Any 
       correspondingProperty: PROPERTY name:testProp visibility:public modality:FINAL [var] 
       BLOCK_BODY
         CALL 'public open fun println (x: kotlin.String?): kotlin.Unit declared in java.io.PrintStream' type=kotlin.Unit origin=null
-          $this: GET_FIELD 'FIELD IR_EXTERNAL_JAVA_DECLARATION_STUB name:out type:java.io.PrintStream? visibility:public [final,static] ' type=java.io.PrintStream? origin=GET_PROPERTY
+          $this: TYPE_OP type=java.io.PrintStream origin=IMPLICIT_NOTNULL typeOperand=java.io.PrintStream
+            GET_FIELD 'FIELD IR_EXTERNAL_JAVA_DECLARATION_STUB name:out type:java.io.PrintStream? visibility:public [final,static] ' type=java.io.PrintStream? origin=GET_PROPERTY
           x: CONST String type=kotlin.String value="testProp/get"
         RETURN type=kotlin.Nothing from='public final fun <get-testProp> (): kotlin.Any declared in <root>'
           CONST Int type=kotlin.Int value=42
@@ -18,7 +20,8 @@ FILE fqName:<root> fileName:/jvmStaticFieldReference.kt
       VALUE_PARAMETER name:value index:0 type:kotlin.Any 
       BLOCK_BODY
         CALL 'public open fun println (x: kotlin.String?): kotlin.Unit declared in java.io.PrintStream' type=kotlin.Unit origin=null
-          $this: GET_FIELD 'FIELD IR_EXTERNAL_JAVA_DECLARATION_STUB name:out type:java.io.PrintStream? visibility:public [final,static] ' type=java.io.PrintStream? origin=GET_PROPERTY
+          $this: TYPE_OP type=java.io.PrintStream origin=IMPLICIT_NOTNULL typeOperand=java.io.PrintStream
+            GET_FIELD 'FIELD IR_EXTERNAL_JAVA_DECLARATION_STUB name:out type:java.io.PrintStream? visibility:public [final,static] ' type=java.io.PrintStream? origin=GET_PROPERTY
           x: CONST String type=kotlin.String value="testProp/set"
   CLASS CLASS name:TestClass modality:FINAL visibility:public superTypes:[kotlin.Any]
     $this: VALUE_PARAMETER INSTANCE_RECEIVER name:<this> type:<root>.TestClass 
@@ -34,7 +37,8 @@ FILE fqName:<root> fileName:/jvmStaticFieldReference.kt
               if: CONST Boolean type=kotlin.Boolean value=true
               then: BLOCK type=kotlin.Int origin=null
                 CALL 'public open fun println (x: kotlin.String?): kotlin.Unit declared in java.io.PrintStream' type=kotlin.Unit origin=null
-                  $this: GET_FIELD 'FIELD IR_EXTERNAL_JAVA_DECLARATION_STUB name:out type:java.io.PrintStream? visibility:public [final,static] ' type=java.io.PrintStream? origin=GET_PROPERTY
+                  $this: TYPE_OP type=java.io.PrintStream origin=IMPLICIT_NOTNULL typeOperand=java.io.PrintStream
+                    GET_FIELD 'FIELD IR_EXTERNAL_JAVA_DECLARATION_STUB name:out type:java.io.PrintStream? visibility:public [final,static] ' type=java.io.PrintStream? origin=GET_PROPERTY
                   x: CONST String type=kotlin.String value="TestClass/test"
                 CONST Int type=kotlin.Int value=42
       FUN DEFAULT_PROPERTY_ACCESSOR name:<get-test> visibility:public modality:FINAL <> ($this:<root>.TestClass) returnType:kotlin.Int 
@@ -47,7 +51,8 @@ FILE fqName:<root> fileName:/jvmStaticFieldReference.kt
     ANONYMOUS_INITIALIZER isStatic=false
       BLOCK_BODY
         CALL 'public open fun println (x: kotlin.String?): kotlin.Unit declared in java.io.PrintStream' type=kotlin.Unit origin=null
-          $this: GET_FIELD 'FIELD IR_EXTERNAL_JAVA_DECLARATION_STUB name:out type:java.io.PrintStream? visibility:public [final,static] ' type=java.io.PrintStream? origin=GET_PROPERTY
+          $this: TYPE_OP type=java.io.PrintStream origin=IMPLICIT_NOTNULL typeOperand=java.io.PrintStream
+            GET_FIELD 'FIELD IR_EXTERNAL_JAVA_DECLARATION_STUB name:out type:java.io.PrintStream? visibility:public [final,static] ' type=java.io.PrintStream? origin=GET_PROPERTY
           x: CONST String type=kotlin.String value="TestClass/init"
     FUN FAKE_OVERRIDE name:equals visibility:public modality:OPEN <> ($this:kotlin.Any, other:kotlin.Any?) returnType:kotlin.Boolean 
       overridden:

compiler/testData/ir/irText/expressions/sam/samConversionsWithSmartCasts.txt

@@ -106,9 +106,10 @@ FILE fqName:<root> fileName:/samConversionsWithSmartCasts.kt
       CALL 'public open fun run1 (r: java.lang.Runnable?): kotlin.Unit declared in <root>.J' type=kotlin.Unit origin=null
         $this: CONSTRUCTOR_CALL 'public constructor <init> () [primary] declared in <root>.J' type=<root>.J origin=null
         r: TYPE_OP type=java.lang.Runnable? origin=SAM_CONVERSION typeOperand=java.lang.Runnable?
-          CALL 'public open fun id <T> (x: T of <root>.J.id?): T of <root>.J.id? declared in <root>.J' type=kotlin.Function0<kotlin.Unit>? origin=null
-            <T>: kotlin.Function0<kotlin.Unit>?
-            x: GET_VAR 'a: kotlin.Function0<kotlin.Unit> declared in <root>.test8' type=kotlin.Function0<kotlin.Unit> origin=null
+          TYPE_OP type=kotlin.Function0<kotlin.Unit> origin=IMPLICIT_NOTNULL typeOperand=kotlin.Function0<kotlin.Unit>
+            CALL 'public open fun id <T> (x: T of <root>.J.id?): T of <root>.J.id? declared in <root>.J' type=kotlin.Function0<kotlin.Unit>? origin=null
+              <T>: kotlin.Function0<kotlin.Unit>?
+              x: GET_VAR 'a: kotlin.Function0<kotlin.Unit> declared in <root>.test8' type=kotlin.Function0<kotlin.Unit> origin=null
   FUN name:test9 visibility:public modality:FINAL <> () returnType:kotlin.Unit 
     BLOCK_BODY
       CALL 'public open fun run1 (r: java.lang.Runnable?): kotlin.Unit declared in <root>.J' type=kotlin.Unit origin=null

compiler/testData/ir/irText/types/explicitEqualsAndCompareToCallsOnPlatformTypeReceiver.fir.txt

@@ -0,0 +1,31 @@
+FILE fqName:<root> fileName:/explicitEqualsAndCompareToCallsOnPlatformTypeReceiver.kt
+  FUN name:testPlatformEqualsPlatform visibility:public modality:FINAL <> () returnType:IrErrorType
+    BLOCK_BODY
+      RETURN type=kotlin.Nothing from='public final fun testPlatformEqualsPlatform (): IrErrorType declared in <root>'
+        ERROR_CALL 'Unresolved reference: <Ambiguity: equals, [kotlin/Any.equals, kotlin/Any.equals]>#' type=IrErrorType
+          CALL 'public open fun null0 (): kotlin.Double? declared in <root>.JavaClass' type=kotlin.Double? origin=null
+  FUN name:testPlatformEqualsKotlin visibility:public modality:FINAL <> () returnType:IrErrorType
+    BLOCK_BODY
+      RETURN type=kotlin.Nothing from='public final fun testPlatformEqualsKotlin (): IrErrorType declared in <root>'
+        ERROR_CALL 'Unresolved reference: <Ambiguity: equals, [kotlin/Any.equals, kotlin/Any.equals]>#' type=IrErrorType
+          CONST Double type=kotlin.Double value=0.0
+  FUN name:testKotlinEqualsPlatform visibility:public modality:FINAL <> () returnType:IrErrorType
+    BLOCK_BODY
+      RETURN type=kotlin.Nothing from='public final fun testKotlinEqualsPlatform (): IrErrorType declared in <root>'
+        ERROR_CALL 'Unresolved reference: <Ambiguity: equals, [kotlin/Any.equals, kotlin/Any.equals]>#' type=IrErrorType
+          CALL 'public open fun null0 (): kotlin.Double? declared in <root>.JavaClass' type=kotlin.Double? origin=null
+  FUN name:testPlatformCompareToPlatform visibility:public modality:FINAL <> () returnType:IrErrorType
+    BLOCK_BODY
+      RETURN type=kotlin.Nothing from='public final fun testPlatformCompareToPlatform (): IrErrorType declared in <root>'
+        ERROR_CALL 'Unresolved reference: <Ambiguity: compareTo, [kotlin/Double.compareTo, kotlin/Double.compareTo, kotlin/Double.compareTo, kotlin/Double.compareTo, kotlin/Double.compareTo, kotlin/Double.compareTo, kotlin/Comparable.compareTo]>#' type=IrErrorType
+          CALL 'public open fun null0 (): kotlin.Double? declared in <root>.JavaClass' type=kotlin.Double? origin=null
+  FUN name:testPlatformCompareToKotlin visibility:public modality:FINAL <> () returnType:IrErrorType
+    BLOCK_BODY
+      RETURN type=kotlin.Nothing from='public final fun testPlatformCompareToKotlin (): IrErrorType declared in <root>'
+        ERROR_CALL 'Unresolved reference: <Ambiguity: compareTo, [kotlin/Double.compareTo, kotlin/Double.compareTo, kotlin/Double.compareTo, kotlin/Double.compareTo, kotlin/Double.compareTo, kotlin/Double.compareTo, kotlin/Comparable.compareTo]>#' type=IrErrorType
+          CONST Double type=kotlin.Double value=0.0
+  FUN name:testKotlinCompareToPlatform visibility:public modality:FINAL <> () returnType:IrErrorType
+    BLOCK_BODY
+      RETURN type=kotlin.Nothing from='public final fun testKotlinCompareToPlatform (): IrErrorType declared in <root>'
+        ERROR_CALL 'Unresolved reference: <Ambiguity: compareTo, [kotlin/Double.compareTo, kotlin/Double.compareTo, kotlin/Double.compareTo, kotlin/Double.compareTo, kotlin/Double.compareTo, kotlin/Double.compareTo, kotlin/Comparable.compareTo]>#' type=IrErrorType
+          CALL 'public open fun null0 (): kotlin.Double? declared in <root>.JavaClass' type=kotlin.Double? origin=null

compiler/testData/ir/irText/types/explicitEqualsAndCompareToCallsOnPlatformTypeReceiver.kt

@@ -0,0 +1,28 @@
+// FILE: explicitEqualsAndCompareToCallsOnPlatformTypeReceiver.kt
+
+fun JavaClass.testPlatformEqualsPlatform() =
+    null0().equals(null0())
+
+fun JavaClass.testPlatformEqualsKotlin() =
+    null0().equals(0.0)
+
+fun JavaClass.testKotlinEqualsPlatform() =
+    0.0.equals(null0())
+
+fun JavaClass.testPlatformCompareToPlatform() =
+    null0().compareTo(null0())
+
+fun JavaClass.testPlatformCompareToKotlin() =
+    null0().compareTo(0.0)
+
+fun JavaClass.testKotlinCompareToPlatform() =
+    0.0.compareTo(null0())
+
+// FILE: JavaClass.java
+
+public class JavaClass {
+    public Double null0(){
+        return null;
+    }
+
+}

compiler/testData/ir/irText/types/explicitEqualsAndCompareToCallsOnPlatformTypeReceiver.txt

@@ -0,0 +1,57 @@
+FILE fqName:<root> fileName:/explicitEqualsAndCompareToCallsOnPlatformTypeReceiver.kt
+  FUN name:testPlatformEqualsPlatform visibility:public modality:FINAL <> ($receiver:<root>.JavaClass) returnType:kotlin.Boolean
+    $receiver: VALUE_PARAMETER name:<this> type:<root>.JavaClass
+    BLOCK_BODY
+      RETURN type=kotlin.Nothing from='public final fun testPlatformEqualsPlatform (): kotlin.Boolean declared in <root>'
+        CALL 'public open fun equals (other: kotlin.Any?): kotlin.Boolean declared in kotlin.Double' type=kotlin.Boolean origin=null
+          $this: TYPE_OP type=kotlin.Double origin=IMPLICIT_NOTNULL typeOperand=kotlin.Double
+            CALL 'public open fun null0 (): kotlin.Double? declared in <root>.JavaClass' type=kotlin.Double? origin=null
+              $this: GET_VAR '<this>: <root>.JavaClass declared in <root>.testPlatformEqualsPlatform' type=<root>.JavaClass origin=null
+          other: CALL 'public open fun null0 (): kotlin.Double? declared in <root>.JavaClass' type=kotlin.Double? origin=null
+            $this: GET_VAR '<this>: <root>.JavaClass declared in <root>.testPlatformEqualsPlatform' type=<root>.JavaClass origin=null
+  FUN name:testPlatformEqualsKotlin visibility:public modality:FINAL <> ($receiver:<root>.JavaClass) returnType:kotlin.Boolean
+    $receiver: VALUE_PARAMETER name:<this> type:<root>.JavaClass
+    BLOCK_BODY
+      RETURN type=kotlin.Nothing from='public final fun testPlatformEqualsKotlin (): kotlin.Boolean declared in <root>'
+        CALL 'public open fun equals (other: kotlin.Any?): kotlin.Boolean declared in kotlin.Double' type=kotlin.Boolean origin=null
+          $this: TYPE_OP type=kotlin.Double origin=IMPLICIT_NOTNULL typeOperand=kotlin.Double
+            CALL 'public open fun null0 (): kotlin.Double? declared in <root>.JavaClass' type=kotlin.Double? origin=null
+              $this: GET_VAR '<this>: <root>.JavaClass declared in <root>.testPlatformEqualsKotlin' type=<root>.JavaClass origin=null
+          other: CONST Double type=kotlin.Double value=0.0
+  FUN name:testKotlinEqualsPlatform visibility:public modality:FINAL <> ($receiver:<root>.JavaClass) returnType:kotlin.Boolean
+    $receiver: VALUE_PARAMETER name:<this> type:<root>.JavaClass
+    BLOCK_BODY
+      RETURN type=kotlin.Nothing from='public final fun testKotlinEqualsPlatform (): kotlin.Boolean declared in <root>'
+        CALL 'public open fun equals (other: kotlin.Any?): kotlin.Boolean declared in kotlin.Double' type=kotlin.Boolean origin=null
+          $this: CONST Double type=kotlin.Double value=0.0
+          other: CALL 'public open fun null0 (): kotlin.Double? declared in <root>.JavaClass' type=kotlin.Double? origin=null
+            $this: GET_VAR '<this>: <root>.JavaClass declared in <root>.testKotlinEqualsPlatform' type=<root>.JavaClass origin=null
+  FUN name:testPlatformCompareToPlatform visibility:public modality:FINAL <> ($receiver:<root>.JavaClass) returnType:kotlin.Int
+    $receiver: VALUE_PARAMETER name:<this> type:<root>.JavaClass
+    BLOCK_BODY
+      RETURN type=kotlin.Nothing from='public final fun testPlatformCompareToPlatform (): kotlin.Int declared in <root>'
+        CALL 'public open fun compareTo (other: kotlin.Double): kotlin.Int declared in kotlin.Double' type=kotlin.Int origin=null
+          $this: TYPE_OP type=kotlin.Double origin=IMPLICIT_NOTNULL typeOperand=kotlin.Double
+            CALL 'public open fun null0 (): kotlin.Double? declared in <root>.JavaClass' type=kotlin.Double? origin=null
+              $this: GET_VAR '<this>: <root>.JavaClass declared in <root>.testPlatformCompareToPlatform' type=<root>.JavaClass origin=null
+          other: TYPE_OP type=kotlin.Double origin=IMPLICIT_NOTNULL typeOperand=kotlin.Double
+            CALL 'public open fun null0 (): kotlin.Double? declared in <root>.JavaClass' type=kotlin.Double? origin=null
+              $this: GET_VAR '<this>: <root>.JavaClass declared in <root>.testPlatformCompareToPlatform' type=<root>.JavaClass origin=null
+  FUN name:testPlatformCompareToKotlin visibility:public modality:FINAL <> ($receiver:<root>.JavaClass) returnType:kotlin.Int
+    $receiver: VALUE_PARAMETER name:<this> type:<root>.JavaClass
+    BLOCK_BODY
+      RETURN type=kotlin.Nothing from='public final fun testPlatformCompareToKotlin (): kotlin.Int declared in <root>'
+        CALL 'public open fun compareTo (other: kotlin.Double): kotlin.Int declared in kotlin.Double' type=kotlin.Int origin=null
+          $this: TYPE_OP type=kotlin.Double origin=IMPLICIT_NOTNULL typeOperand=kotlin.Double
+            CALL 'public open fun null0 (): kotlin.Double? declared in <root>.JavaClass' type=kotlin.Double? origin=null
+              $this: GET_VAR '<this>: <root>.JavaClass declared in <root>.testPlatformCompareToKotlin' type=<root>.JavaClass origin=null
+          other: CONST Double type=kotlin.Double value=0.0
+  FUN name:testKotlinCompareToPlatform visibility:public modality:FINAL <> ($receiver:<root>.JavaClass) returnType:kotlin.Int
+    $receiver: VALUE_PARAMETER name:<this> type:<root>.JavaClass
+    BLOCK_BODY
+      RETURN type=kotlin.Nothing from='public final fun testKotlinCompareToPlatform (): kotlin.Int declared in <root>'
+        CALL 'public open fun compareTo (other: kotlin.Double): kotlin.Int declared in kotlin.Double' type=kotlin.Int origin=null
+          $this: CONST Double type=kotlin.Double value=0.0
+          other: TYPE_OP type=kotlin.Double origin=IMPLICIT_NOTNULL typeOperand=kotlin.Double
+            CALL 'public open fun null0 (): kotlin.Double? declared in <root>.JavaClass' type=kotlin.Double? origin=null
+              $this: GET_VAR '<this>: <root>.JavaClass declared in <root>.testKotlinCompareToPlatform' type=<root>.JavaClass origin=null

compiler/testData/ir/irText/types/nullabilityAssertionOnExtensionReceiver.fir.txt

@@ -0,0 +1,31 @@
+FILE fqName:<root> fileName:/nullabilityAssertionOnExtensionReceiver.kt
+  FUN name:extension visibility:public modality:FINAL <> () returnType:kotlin.Unit
+    BLOCK_BODY
+  CLASS CLASS name:C modality:FINAL visibility:public superTypes:[kotlin.Any]
+    $this: VALUE_PARAMETER INSTANCE_RECEIVER name:<this> type:<root>.C
+    CONSTRUCTOR visibility:public <> () returnType:<root>.C [primary]
+      BLOCK_BODY
+        DELEGATING_CONSTRUCTOR_CALL 'public constructor <init> () [primary] declared in kotlin.Any'
+        INSTANCE_INITIALIZER_CALL classDescriptor='CLASS CLASS name:C modality:FINAL visibility:public superTypes:[kotlin.Any]'
+    FUN name:memberExtension visibility:public modality:FINAL <> ($this:<root>.C) returnType:kotlin.Unit
+      $this: VALUE_PARAMETER name:<this> type:<root>.C
+      BLOCK_BODY
+    FUN FAKE_OVERRIDE name:equals visibility:public modality:OPEN <> ($this:kotlin.Any, other:kotlin.Any?) returnType:kotlin.Boolean
+      overridden:
+        public open fun equals (other: kotlin.Any?): kotlin.Boolean declared in kotlin.Any
+      $this: VALUE_PARAMETER name:<this> type:kotlin.Any
+      VALUE_PARAMETER name:other index:0 type:kotlin.Any?
+    FUN FAKE_OVERRIDE name:hashCode visibility:public modality:OPEN <> ($this:kotlin.Any) returnType:kotlin.Int
+      overridden:
+        public open fun hashCode (): kotlin.Int declared in kotlin.Any
+      $this: VALUE_PARAMETER name:<this> type:kotlin.Any
+    FUN FAKE_OVERRIDE name:toString visibility:public modality:OPEN <> ($this:kotlin.Any) returnType:kotlin.String
+      overridden:
+        public open fun toString (): kotlin.String declared in kotlin.Any
+      $this: VALUE_PARAMETER name:<this> type:kotlin.Any
+  FUN name:testExt visibility:public modality:FINAL <> () returnType:kotlin.Unit
+    BLOCK_BODY
+      CALL 'public final fun extension (): kotlin.Unit declared in <root>' type=kotlin.Unit origin=null
+  FUN name:testMemberExt visibility:public modality:FINAL <> () returnType:kotlin.Unit
+    BLOCK_BODY
+      CALL 'public final fun memberExtension (): kotlin.Unit declared in <root>.C' type=kotlin.Unit origin=null

compiler/testData/ir/irText/types/nullabilityAssertionOnExtensionReceiver.kt

@@ -0,0 +1,20 @@
+// FILE: nullabilityAssertionOnExtensionReceiver.kt
+
+fun String.extension() {}
+
+class C {
+    fun String.memberExtension() {}
+}
+
+fun testExt() {
+    J.s().extension()
+}
+
+fun C.testMemberExt() {
+    J.s().memberExtension()
+}
+
+// FILE: J.java
+public class J {
+    public static String s() { return null; }
+}

compiler/testData/ir/irText/types/nullabilityAssertionOnExtensionReceiver.txt

@@ -0,0 +1,39 @@
+FILE fqName:<root> fileName:/nullabilityAssertionOnExtensionReceiver.kt
+  FUN name:extension visibility:public modality:FINAL <> ($receiver:kotlin.String) returnType:kotlin.Unit
+    $receiver: VALUE_PARAMETER name:<this> type:kotlin.String
+    BLOCK_BODY
+  CLASS CLASS name:C modality:FINAL visibility:public superTypes:[kotlin.Any]
+    $this: VALUE_PARAMETER INSTANCE_RECEIVER name:<this> type:<root>.C
+    CONSTRUCTOR visibility:public <> () returnType:<root>.C [primary]
+      BLOCK_BODY
+        DELEGATING_CONSTRUCTOR_CALL 'public constructor <init> () [primary] declared in kotlin.Any'
+        INSTANCE_INITIALIZER_CALL classDescriptor='CLASS CLASS name:C modality:FINAL visibility:public superTypes:[kotlin.Any]'
+    FUN name:memberExtension visibility:public modality:FINAL <> ($this:<root>.C, $receiver:kotlin.String) returnType:kotlin.Unit
+      $this: VALUE_PARAMETER name:<this> type:<root>.C
+      $receiver: VALUE_PARAMETER name:<this> type:kotlin.String
+      BLOCK_BODY
+    FUN FAKE_OVERRIDE name:equals visibility:public modality:OPEN <> ($this:kotlin.Any, other:kotlin.Any?) returnType:kotlin.Boolean
+      overridden:
+        public open fun equals (other: kotlin.Any?): kotlin.Boolean declared in kotlin.Any
+      $this: VALUE_PARAMETER name:<this> type:kotlin.Any
+      VALUE_PARAMETER name:other index:0 type:kotlin.Any?
+    FUN FAKE_OVERRIDE name:hashCode visibility:public modality:OPEN <> ($this:kotlin.Any) returnType:kotlin.Int
+      overridden:
+        public open fun hashCode (): kotlin.Int declared in kotlin.Any
+      $this: VALUE_PARAMETER name:<this> type:kotlin.Any
+    FUN FAKE_OVERRIDE name:toString visibility:public modality:OPEN <> ($this:kotlin.Any) returnType:kotlin.String
+      overridden:
+        public open fun toString (): kotlin.String declared in kotlin.Any
+      $this: VALUE_PARAMETER name:<this> type:kotlin.Any
+  FUN name:testExt visibility:public modality:FINAL <> () returnType:kotlin.Unit
+    BLOCK_BODY
+      CALL 'public final fun extension (): kotlin.Unit declared in <root>' type=kotlin.Unit origin=null
+        $receiver: TYPE_OP type=kotlin.String origin=IMPLICIT_NOTNULL typeOperand=kotlin.String
+          CALL 'public open fun s (): kotlin.String? declared in <root>.J' type=kotlin.String? origin=null
+  FUN name:testMemberExt visibility:public modality:FINAL <> ($receiver:<root>.C) returnType:kotlin.Unit
+    $receiver: VALUE_PARAMETER name:<this> type:<root>.C
+    BLOCK_BODY
+      CALL 'public final fun memberExtension (): kotlin.Unit declared in <root>.C' type=kotlin.Unit origin=null
+        $this: GET_VAR '<this>: <root>.C declared in <root>.testMemberExt' type=<root>.C origin=null
+        $receiver: TYPE_OP type=kotlin.String origin=IMPLICIT_NOTNULL typeOperand=kotlin.String
+          CALL 'public open fun s (): kotlin.String? declared in <root>.J' type=kotlin.String? origin=null

compiler/tests/org/jetbrains/kotlin/ir/IrTextTestCaseGenerated.java

@@ -1606,6 +1606,11 @@ public class IrTextTestCaseGenerated extends AbstractIrTextTestCase {
             KotlinTestUtils.assertAllTestsPresentByMetadata(this.getClass(), new File("compiler/testData/ir/irText/types"), Pattern.compile("^(.+)\\.kt$"), TargetBackend.ANY, true);
         }
 
+        @TestMetadata("explicitEqualsAndCompareToCallsOnPlatformTypeReceiver.kt")
+        public void testExplicitEqualsAndCompareToCallsOnPlatformTypeReceiver() throws Exception {
+            runTest("compiler/testData/ir/irText/types/explicitEqualsAndCompareToCallsOnPlatformTypeReceiver.kt");
+        }
+
         @TestMetadata("intersectionType1_NI.kt")
         public void testIntersectionType1_NI() throws Exception {
             runTest("compiler/testData/ir/irText/types/intersectionType1_NI.kt");
@@ -1640,5 +1645,10 @@ public class IrTextTestCaseGenerated extends AbstractIrTextTestCase {
         public void testLocalVariableOfIntersectionType_NI() throws Exception {
             runTest("compiler/testData/ir/irText/types/localVariableOfIntersectionType_NI.kt");
         }
+
+        @TestMetadata("nullabilityAssertionOnExtensionReceiver.kt")
+        public void testNullabilityAssertionOnExtensionReceiver() throws Exception {
+            runTest("compiler/testData/ir/irText/types/nullabilityAssertionOnExtensionReceiver.kt");
+        }
     }
 }