Psi2Ir: fix usage of flexible vararg type after approximation

This only affects JVM IR, and this is similar to how this was done in
the old JVM backend in `CallBasedArgumentGenerator.generateVararg`.

 #KT-52146 Fixed

compiler/fir/fir2ir/tests-gen/org/jetbrains/kotlin/test/runners/codegen/FirBlackBoxCodegenTestGenerated.java

@@ -48371,6 +48371,12 @@ public class FirBlackBoxCodegenTestGenerated extends AbstractFirBlackBoxCodegenT
             runTest("compiler/testData/codegen/box/vararg/kt46092.kt");
         }
 
+        @Test
+        @TestMetadata("kt52146_samWithSelfTypeAndStarProjection.kt")
+        public void testKt52146_samWithSelfTypeAndStarProjection() throws Exception {
+            runTest("compiler/testData/codegen/box/vararg/kt52146_samWithSelfTypeAndStarProjection.kt");
+        }
+
         @Test
         @TestMetadata("kt581.kt")
         public void testKt581() throws Exception {

compiler/ir/ir.psi2ir/src/org/jetbrains/kotlin/psi2ir/generators/ArgumentsGenerationUtils.kt

@@ -299,6 +299,11 @@ private fun StatementGenerator.generateReceiverForCalleeImportedFromObject(
     }
 }
 
+private fun StatementGenerator.computeVarargType(type: KotlinType): IrType =
+    // Vararg type loaded from Java can be flexible, and have `Nothing` as lower bound after approximation. (See KT-52146.)
+    // Its upper bound should always have the form `Array<out T>`, though.
+    type.upperIfFlexible().toIrType()
+
 private fun StatementGenerator.generateVarargExpressionUsing(
     varargArgument: VarargValueArgument,
     valueParameter: ValueParameterDescriptor,
@@ -319,7 +324,7 @@ private fun StatementGenerator.generateVarargExpressionUsing(
     val varargElementType =
         valueParameter.varargElementType ?: throw AssertionError("Vararg argument for non-vararg parameter $valueParameter")
 
-    val irVararg = IrVarargImpl(varargStartOffset, varargEndOffset, valueParameter.type.toIrType(), varargElementType.toIrType())
+    val irVararg = IrVarargImpl(varargStartOffset, varargEndOffset, computeVarargType(valueParameter.type), varargElementType.toIrType())
 
     for (varargElementArgument in varargArgument.arguments) {
         val ktArgumentExpression = varargElementArgument.getArgumentExpression()
@@ -714,7 +719,7 @@ fun StatementGenerator.generateSamConversionForValueArgumentsIfRequired(call: Ca
 
                 IrVarargImpl(
                     originalArgument.startOffset, originalArgument.endOffset,
-                    substitutedVarargType.toIrType(),
+                    computeVarargType(substitutedVarargType),
                     irSamType
                 ).apply {
                     originalArgument.elements.mapIndexedTo(elements) { index, element ->

compiler/testData/codegen/box/vararg/kt52146_samWithSelfTypeAndStarProjection.kt

@@ -0,0 +1,27 @@
+// TARGET_BACKEND: JVM
+// FULL_JDK
+// JVM_TARGET: 1.8
+// FILE: J.java
+
+import java.util.function.*;
+
+public class J<SELF extends J<SELF, ACTUAL>, ACTUAL> {
+    public final SELF satisfies(Consumer<? super ACTUAL>... c) {
+        return null;
+    }
+}
+
+// FILE: box.kt
+
+import java.util.function.*
+
+fun test(j: J<*, *>) {
+    j.satisfies(Consumer { it is CharSequence })
+    j.satisfies({ it is CharSequence })
+}
+
+fun box(): String {
+    class K : J<K, String>()
+    test(K())
+    return "OK"
+}

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

@@ -21,7 +21,7 @@ FILE fqName:<root> fileName:/arrayAsVarargAfterSamArgument.kt
                 BLOCK_BODY
                   RETURN type=kotlin.Nothing from='local final fun <anonymous> (): kotlin.Unit declared in <root>.test'
                     GET_OBJECT 'CLASS IR_EXTERNAL_DECLARATION_STUB OBJECT name:Unit modality:FINAL visibility:public superTypes:[kotlin.Any]' type=kotlin.Unit
-          strs: VARARG type=@[FlexibleNullability] kotlin.Array<out @[FlexibleNullability] kotlin.String?>? varargElementType=@[FlexibleNullability] kotlin.String?
+          strs: VARARG type=kotlin.Array<out @[FlexibleNullability] kotlin.String?>? varargElementType=@[FlexibleNullability] kotlin.String?
             SPREAD_ELEMENT
               GET_VAR 'arr: kotlin.Array<kotlin.String> declared in <root>.test' type=kotlin.Array<kotlin.String> origin=null
       TYPE_OP type=kotlin.Unit origin=IMPLICIT_COERCION_TO_UNIT typeOperand=kotlin.Unit
@@ -33,13 +33,13 @@ FILE fqName:<root> fileName:/arrayAsVarargAfterSamArgument.kt
         CALL 'public open fun foo1 (r: @[FlexibleNullability] java.lang.Runnable?, vararg strs: @[FlexibleNullability] kotlin.String?): @[FlexibleNullability] kotlin.String? declared in <root>.Test' type=@[FlexibleNullability] kotlin.String? origin=null
           r: TYPE_OP type=@[FlexibleNullability] java.lang.Runnable? origin=SAM_CONVERSION typeOperand=@[FlexibleNullability] java.lang.Runnable?
             GET_VAR 'fn: kotlin.Function0<kotlin.Unit> declared in <root>.test' type=kotlin.Function0<kotlin.Unit> origin=null
-          strs: VARARG type=@[FlexibleNullability] kotlin.Array<out @[FlexibleNullability] kotlin.String?>? varargElementType=@[FlexibleNullability] kotlin.String?
+          strs: VARARG type=kotlin.Array<out @[FlexibleNullability] kotlin.String?>? varargElementType=@[FlexibleNullability] kotlin.String?
             SPREAD_ELEMENT
               GET_VAR 'arr: kotlin.Array<kotlin.String> declared in <root>.test' type=kotlin.Array<kotlin.String> origin=null
       TYPE_OP type=kotlin.Unit origin=IMPLICIT_COERCION_TO_UNIT typeOperand=kotlin.Unit
         CALL 'public open fun foo1 (r: @[FlexibleNullability] java.lang.Runnable?, vararg strs: @[FlexibleNullability] kotlin.String?): @[FlexibleNullability] kotlin.String? declared in <root>.Test' type=@[FlexibleNullability] kotlin.String? origin=null
           r: GET_VAR 'r: java.lang.Runnable declared in <root>.test' type=java.lang.Runnable origin=null
-          strs: VARARG type=@[FlexibleNullability] kotlin.Array<out @[FlexibleNullability] kotlin.String?>? varargElementType=@[FlexibleNullability] kotlin.String?
+          strs: VARARG type=kotlin.Array<out @[FlexibleNullability] kotlin.String?>? varargElementType=@[FlexibleNullability] kotlin.String?
             CONST String type=kotlin.String value=""
       TYPE_OP type=kotlin.Unit origin=IMPLICIT_COERCION_TO_UNIT typeOperand=kotlin.Unit
         CALL 'public open fun foo1 (r: @[FlexibleNullability] java.lang.Runnable?, vararg strs: @[FlexibleNullability] kotlin.String?): @[FlexibleNullability] kotlin.String? declared in <root>.Test' type=@[FlexibleNullability] kotlin.String? origin=null
@@ -50,13 +50,13 @@ FILE fqName:<root> fileName:/arrayAsVarargAfterSamArgument.kt
         CALL 'public open fun foo1 (r: @[FlexibleNullability] java.lang.Runnable?, vararg strs: @[FlexibleNullability] kotlin.String?): @[FlexibleNullability] kotlin.String? declared in <root>.Test' type=@[FlexibleNullability] kotlin.String? origin=null
           r: TYPE_OP type=@[FlexibleNullability] java.lang.Runnable? origin=SAM_CONVERSION typeOperand=@[FlexibleNullability] java.lang.Runnable?
             GET_VAR 'fn: kotlin.Function0<kotlin.Unit> declared in <root>.test' type=kotlin.Function0<kotlin.Unit> origin=null
-          strs: VARARG type=@[FlexibleNullability] kotlin.Array<out @[FlexibleNullability] kotlin.String?>? varargElementType=@[FlexibleNullability] kotlin.String?
+          strs: VARARG type=kotlin.Array<out @[FlexibleNullability] kotlin.String?>? varargElementType=@[FlexibleNullability] kotlin.String?
             SPREAD_ELEMENT
               GET_VAR 'arr: kotlin.Array<kotlin.String> declared in <root>.test' type=kotlin.Array<kotlin.String> origin=null
       TYPE_OP type=kotlin.Unit origin=IMPLICIT_COERCION_TO_UNIT typeOperand=kotlin.Unit
         CALL 'public open fun foo1 (r: @[FlexibleNullability] java.lang.Runnable?, vararg strs: @[FlexibleNullability] kotlin.String?): @[FlexibleNullability] kotlin.String? declared in <root>.Test' type=@[FlexibleNullability] kotlin.String? origin=null
           r: GET_VAR 'r: java.lang.Runnable declared in <root>.test' type=java.lang.Runnable origin=null
-          strs: VARARG type=@[FlexibleNullability] kotlin.Array<out @[FlexibleNullability] kotlin.String?>? varargElementType=@[FlexibleNullability] kotlin.String?
+          strs: VARARG type=kotlin.Array<out @[FlexibleNullability] kotlin.String?>? varargElementType=@[FlexibleNullability] kotlin.String?
             SPREAD_ELEMENT
               GET_VAR 'arr: kotlin.Array<kotlin.String> declared in <root>.test' type=kotlin.Array<kotlin.String> origin=null
       VAR name:i1 type:<root>.Test [val]
@@ -76,7 +76,7 @@ FILE fqName:<root> fileName:/arrayAsVarargAfterSamArgument.kt
                 BLOCK_BODY
                   RETURN type=kotlin.Nothing from='local final fun <anonymous> (): kotlin.Unit declared in <root>.test'
                     GET_OBJECT 'CLASS IR_EXTERNAL_DECLARATION_STUB OBJECT name:Unit modality:FINAL visibility:public superTypes:[kotlin.Any]' type=kotlin.Unit
-          strs: VARARG type=@[FlexibleNullability] kotlin.Array<out @[FlexibleNullability] kotlin.String?>? varargElementType=@[FlexibleNullability] kotlin.String?
+          strs: VARARG type=kotlin.Array<out @[FlexibleNullability] kotlin.String?>? varargElementType=@[FlexibleNullability] kotlin.String?
             SPREAD_ELEMENT
               GET_VAR 'arr: kotlin.Array<kotlin.String> declared in <root>.test' type=kotlin.Array<kotlin.String> origin=null
       VAR name:i3 type:<root>.Test [val]
@@ -103,7 +103,7 @@ FILE fqName:<root> fileName:/arrayAsVarargAfterSamArgument.kt
                 BLOCK_BODY
                   RETURN type=kotlin.Nothing from='local final fun <anonymous> (): kotlin.Unit declared in <root>.test'
                     GET_OBJECT 'CLASS IR_EXTERNAL_DECLARATION_STUB OBJECT name:Unit modality:FINAL visibility:public superTypes:[kotlin.Any]' type=kotlin.Unit
-          strs: VARARG type=@[FlexibleNullability] kotlin.Array<out @[FlexibleNullability] kotlin.String?>? varargElementType=@[FlexibleNullability] kotlin.String?
+          strs: VARARG type=kotlin.Array<out @[FlexibleNullability] kotlin.String?>? varargElementType=@[FlexibleNullability] kotlin.String?
             CONST String type=kotlin.String value=""
       VAR name:i5 type:<root>.Test [val]
         CONSTRUCTOR_CALL 'public constructor <init> (r1: @[FlexibleNullability] java.lang.Runnable?, r2: @[FlexibleNullability] java.lang.Runnable?, vararg strs: @[FlexibleNullability] kotlin.String?) declared in <root>.Test' type=<root>.Test origin=null
@@ -119,7 +119,7 @@ FILE fqName:<root> fileName:/arrayAsVarargAfterSamArgument.kt
                 BLOCK_BODY
                   RETURN type=kotlin.Nothing from='local final fun <anonymous> (): kotlin.Unit declared in <root>.test'
                     GET_OBJECT 'CLASS IR_EXTERNAL_DECLARATION_STUB OBJECT name:Unit modality:FINAL visibility:public superTypes:[kotlin.Any]' type=kotlin.Unit
-          strs: VARARG type=@[FlexibleNullability] kotlin.Array<out @[FlexibleNullability] kotlin.String?>? varargElementType=@[FlexibleNullability] kotlin.String?
+          strs: VARARG type=kotlin.Array<out @[FlexibleNullability] kotlin.String?>? varargElementType=@[FlexibleNullability] kotlin.String?
             SPREAD_ELEMENT
               GET_VAR 'arr: kotlin.Array<kotlin.String> declared in <root>.test' type=kotlin.Array<kotlin.String> origin=null
       VAR name:i6 type:<root>.Test [val]
@@ -131,7 +131,7 @@ FILE fqName:<root> fileName:/arrayAsVarargAfterSamArgument.kt
                 BLOCK_BODY
                   RETURN type=kotlin.Nothing from='local final fun <anonymous> (): kotlin.Unit declared in <root>.test'
                     GET_OBJECT 'CLASS IR_EXTERNAL_DECLARATION_STUB OBJECT name:Unit modality:FINAL visibility:public superTypes:[kotlin.Any]' type=kotlin.Unit
-          strs: VARARG type=@[FlexibleNullability] kotlin.Array<out @[FlexibleNullability] kotlin.String?>? varargElementType=@[FlexibleNullability] kotlin.String?
+          strs: VARARG type=kotlin.Array<out @[FlexibleNullability] kotlin.String?>? varargElementType=@[FlexibleNullability] kotlin.String?
             SPREAD_ELEMENT
               GET_VAR 'arr: kotlin.Array<kotlin.String> declared in <root>.test' type=kotlin.Array<kotlin.String> origin=null
       TYPE_OP type=kotlin.Unit origin=IMPLICIT_COERCION_TO_UNIT typeOperand=kotlin.Unit
@@ -160,7 +160,7 @@ FILE fqName:<root> fileName:/arrayAsVarargAfterSamArgument.kt
                 BLOCK_BODY
                   RETURN type=kotlin.Nothing from='local final fun <anonymous> (): kotlin.Unit declared in <root>.test'
                     GET_OBJECT 'CLASS IR_EXTERNAL_DECLARATION_STUB OBJECT name:Unit modality:FINAL visibility:public superTypes:[kotlin.Any]' type=kotlin.Unit
-          strs: VARARG type=@[FlexibleNullability] kotlin.Array<out @[FlexibleNullability] kotlin.String?>? varargElementType=@[FlexibleNullability] kotlin.String?
+          strs: VARARG type=kotlin.Array<out @[FlexibleNullability] kotlin.String?>? varargElementType=@[FlexibleNullability] kotlin.String?
             CONST String type=kotlin.String value=""
       TYPE_OP type=kotlin.Unit origin=IMPLICIT_COERCION_TO_UNIT typeOperand=kotlin.Unit
         CALL 'public open fun foo2 (r1: @[FlexibleNullability] java.lang.Runnable?, r2: @[FlexibleNullability] java.lang.Runnable?, vararg strs: @[FlexibleNullability] kotlin.String?): @[FlexibleNullability] kotlin.String? declared in <root>.Test' type=@[FlexibleNullability] kotlin.String? origin=null
@@ -177,7 +177,7 @@ FILE fqName:<root> fileName:/arrayAsVarargAfterSamArgument.kt
                 BLOCK_BODY
                   RETURN type=kotlin.Nothing from='local final fun <anonymous> (): kotlin.Unit declared in <root>.test'
                     GET_OBJECT 'CLASS IR_EXTERNAL_DECLARATION_STUB OBJECT name:Unit modality:FINAL visibility:public superTypes:[kotlin.Any]' type=kotlin.Unit
-          strs: VARARG type=@[FlexibleNullability] kotlin.Array<out @[FlexibleNullability] kotlin.String?>? varargElementType=@[FlexibleNullability] kotlin.String?
+          strs: VARARG type=kotlin.Array<out @[FlexibleNullability] kotlin.String?>? varargElementType=@[FlexibleNullability] kotlin.String?
             SPREAD_ELEMENT
               GET_VAR 'arr: kotlin.Array<kotlin.String> declared in <root>.test' type=kotlin.Array<kotlin.String> origin=null
       TYPE_OP type=kotlin.Unit origin=IMPLICIT_COERCION_TO_UNIT typeOperand=kotlin.Unit
@@ -190,6 +190,6 @@ FILE fqName:<root> fileName:/arrayAsVarargAfterSamArgument.kt
                 BLOCK_BODY
                   RETURN type=kotlin.Nothing from='local final fun <anonymous> (): kotlin.Unit declared in <root>.test'
                     GET_OBJECT 'CLASS IR_EXTERNAL_DECLARATION_STUB OBJECT name:Unit modality:FINAL visibility:public superTypes:[kotlin.Any]' type=kotlin.Unit
-          strs: VARARG type=@[FlexibleNullability] kotlin.Array<out @[FlexibleNullability] kotlin.String?>? varargElementType=@[FlexibleNullability] kotlin.String?
+          strs: VARARG type=kotlin.Array<out @[FlexibleNullability] kotlin.String?>? varargElementType=@[FlexibleNullability] kotlin.String?
             SPREAD_ELEMENT
               GET_VAR 'arr: kotlin.Array<kotlin.String> declared in <root>.test' type=kotlin.Array<kotlin.String> origin=null

compiler/tests-common-new/tests-gen/org/jetbrains/kotlin/test/runners/codegen/BlackBoxCodegenTestGenerated.java

@@ -47783,6 +47783,12 @@ public class BlackBoxCodegenTestGenerated extends AbstractBlackBoxCodegenTest {
             runTest("compiler/testData/codegen/box/vararg/kt46092.kt");
         }
 
+        @Test
+        @TestMetadata("kt52146_samWithSelfTypeAndStarProjection.kt")
+        public void testKt52146_samWithSelfTypeAndStarProjection() throws Exception {
+            runTest("compiler/testData/codegen/box/vararg/kt52146_samWithSelfTypeAndStarProjection.kt");
+        }
+
         @Test
         @TestMetadata("kt581.kt")
         public void testKt581() throws Exception {

compiler/tests-common-new/tests-gen/org/jetbrains/kotlin/test/runners/codegen/IrBlackBoxCodegenTestGenerated.java

@@ -48371,6 +48371,12 @@ public class IrBlackBoxCodegenTestGenerated extends AbstractIrBlackBoxCodegenTes
             runTest("compiler/testData/codegen/box/vararg/kt46092.kt");
         }
 
+        @Test
+        @TestMetadata("kt52146_samWithSelfTypeAndStarProjection.kt")
+        public void testKt52146_samWithSelfTypeAndStarProjection() throws Exception {
+            runTest("compiler/testData/codegen/box/vararg/kt52146_samWithSelfTypeAndStarProjection.kt");
+        }
+
         @Test
         @TestMetadata("kt581.kt")
         public void testKt581() throws Exception {

compiler/tests-gen/org/jetbrains/kotlin/codegen/LightAnalysisModeTestGenerated.java

@@ -38875,6 +38875,11 @@ public class LightAnalysisModeTestGenerated extends AbstractLightAnalysisModeTes
             runTest("compiler/testData/codegen/box/vararg/kt46092.kt");
         }
 
+        @TestMetadata("kt52146_samWithSelfTypeAndStarProjection.kt")
+        public void testKt52146_samWithSelfTypeAndStarProjection() throws Exception {
+            runTest("compiler/testData/codegen/box/vararg/kt52146_samWithSelfTypeAndStarProjection.kt");
+        }
+
         @TestMetadata("kt581.kt")
         public void testKt581() throws Exception {
             runTest("compiler/testData/codegen/box/vararg/kt581.kt");