JVM_IR: change parameter type computation in InlineCallableReferenceToLambda

The reference type is approximated in Psi2Ir, so we may get Nothing as
a reference type argument. Better look at the arguments of the
referenced function.

compiler/ir/backend.jvm/src/org/jetbrains/kotlin/backend/jvm/lower/InlineCallableReferenceToLambda.kt

@@ -7,6 +7,7 @@ package org.jetbrains.kotlin.backend.jvm.lower
 
 import org.jetbrains.kotlin.backend.common.FileLoweringPass
 import org.jetbrains.kotlin.backend.common.IrElementTransformerVoidWithContext
+import org.jetbrains.kotlin.backend.common.ir.allParameters
 import org.jetbrains.kotlin.backend.common.lower.createIrBuilder
 import org.jetbrains.kotlin.backend.common.lower.irBlock
 import org.jetbrains.kotlin.backend.common.phaser.makeIrFilePhase
@@ -25,7 +26,6 @@ import org.jetbrains.kotlin.ir.declarations.*
 import org.jetbrains.kotlin.ir.expressions.*
 import org.jetbrains.kotlin.ir.expressions.impl.IrFunctionReferenceImpl
 import org.jetbrains.kotlin.ir.types.IrSimpleType
-import org.jetbrains.kotlin.ir.types.IrTypeProjection
 import org.jetbrains.kotlin.ir.util.*
 import org.jetbrains.kotlin.ir.visitors.transformChildrenVoid
 import org.jetbrains.kotlin.name.Name
@@ -117,10 +117,20 @@ internal class InlineCallableReferenceToLambdaPhase(val context: JvmBackendConte
         val irBuilder = context.createJvmIrBuilder(currentScope!!.scope.scopeOwnerSymbol, expression.startOffset, expression.endOffset)
         return irBuilder.irBlock(expression, IrStatementOrigin.LAMBDA) {
 
-            val parameterTypes = (expression.type as IrSimpleType).arguments.map { (it as IrTypeProjection).type }
+            // We find the number of parameters for constructed lambda from the type of the function reference,
-            val argumentTypes = parameterTypes.dropLast(1)
+            // but the actual types have to be copied from referencedFunction; function reference argument type may be too
-
+            // specific because of approximation. See compiler/testData/codegen/box/callableReference/function/argumentTypes.kt
             val boundReceiver: Pair<IrValueParameter, IrExpression>? = expression.getArgumentsWithIr().singleOrNull()
+            val nParams = (expression.type as IrSimpleType).arguments.size - 1
+            var toDropAtStart = 0
+            if (boundReceiver != null) toDropAtStart++
+            if (referencedFunction is IrConstructor) toDropAtStart++
+            val argumentTypes = referencedFunction.allParameters.drop(toDropAtStart).take(nParams).map { parameter ->
+                parameter.type.substitute(
+                    referencedFunction.typeParameters,
+                    referencedFunction.typeParameters.indices.map { expression.getTypeArgument(it)!! }
+                )
+            }
 
             val function = buildFun {
                 setSourceRange(expression)

compiler/testData/codegen/box/callableReference/function/argumentTypes.kt

@@ -0,0 +1,12 @@
+// IGNORE_BACKEND_FIR: JVM_IR
+inline fun <TT> id(x: TT): TT = x
+inline fun <TT> String.extId(x: TT): String = this
+
+private fun <T> ff(value: T?): String {
+    // In PSI2IR, the funcref is approximated to Function1<Nothing, Pair<String, T>>
+    value?.let(::id)
+    return value?.let("OK"::extId)!!
+}
+
+fun box() = ff("arg")
+

compiler/tests/org/jetbrains/kotlin/codegen/BlackBoxCodegenTestGenerated.java

@@ -2186,6 +2186,11 @@ public class BlackBoxCodegenTestGenerated extends AbstractBlackBoxCodegenTest {
                 KotlinTestUtils.assertAllTestsPresentByMetadataWithExcluded(this.getClass(), new File("compiler/testData/codegen/box/callableReference/function"), Pattern.compile("^(.+)\\.kt$"), null, TargetBackend.JVM, true);
             }
 
+            @TestMetadata("argumentTypes.kt")
+            public void testArgumentTypes() throws Exception {
+                runTest("compiler/testData/codegen/box/callableReference/function/argumentTypes.kt");
+            }
+
             @TestMetadata("booleanNotIntrinsic.kt")
             public void testBooleanNotIntrinsic() throws Exception {
                 runTest("compiler/testData/codegen/box/callableReference/function/booleanNotIntrinsic.kt");

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

@@ -2186,6 +2186,11 @@ public class LightAnalysisModeTestGenerated extends AbstractLightAnalysisModeTes
                 KotlinTestUtils.assertAllTestsPresentByMetadataWithExcluded(this.getClass(), new File("compiler/testData/codegen/box/callableReference/function"), Pattern.compile("^(.+)\\.kt$"), null, TargetBackend.JVM, true);
             }
 
+            @TestMetadata("argumentTypes.kt")
+            public void testArgumentTypes() throws Exception {
+                runTest("compiler/testData/codegen/box/callableReference/function/argumentTypes.kt");
+            }
+
             @TestMetadata("booleanNotIntrinsic.kt")
             public void testBooleanNotIntrinsic() throws Exception {
                 runTest("compiler/testData/codegen/box/callableReference/function/booleanNotIntrinsic.kt");

compiler/tests/org/jetbrains/kotlin/codegen/ir/FirBlackBoxCodegenTestGenerated.java

@@ -2166,6 +2166,11 @@ public class FirBlackBoxCodegenTestGenerated extends AbstractFirBlackBoxCodegenT
                 KotlinTestUtils.assertAllTestsPresentByMetadataWithExcluded(this.getClass(), new File("compiler/testData/codegen/box/callableReference/function"), Pattern.compile("^(.+)\\.kt$"), null, TargetBackend.JVM_IR, true);
             }
 
+            @TestMetadata("argumentTypes.kt")
+            public void testArgumentTypes() throws Exception {
+                runTest("compiler/testData/codegen/box/callableReference/function/argumentTypes.kt");
+            }
+
             @TestMetadata("booleanNotIntrinsic.kt")
             public void testBooleanNotIntrinsic() throws Exception {
                 runTest("compiler/testData/codegen/box/callableReference/function/booleanNotIntrinsic.kt");

compiler/tests/org/jetbrains/kotlin/codegen/ir/IrBlackBoxCodegenTestGenerated.java

@@ -2166,6 +2166,11 @@ public class IrBlackBoxCodegenTestGenerated extends AbstractIrBlackBoxCodegenTes
                 KotlinTestUtils.assertAllTestsPresentByMetadataWithExcluded(this.getClass(), new File("compiler/testData/codegen/box/callableReference/function"), Pattern.compile("^(.+)\\.kt$"), null, TargetBackend.JVM_IR, true);
             }
 
+            @TestMetadata("argumentTypes.kt")
+            public void testArgumentTypes() throws Exception {
+                runTest("compiler/testData/codegen/box/callableReference/function/argumentTypes.kt");
+            }
+
             @TestMetadata("booleanNotIntrinsic.kt")
             public void testBooleanNotIntrinsic() throws Exception {
                 runTest("compiler/testData/codegen/box/callableReference/function/booleanNotIntrinsic.kt");

js/js.tests/test/org/jetbrains/kotlin/js/test/ir/semantics/IrJsCodegenBoxTestGenerated.java

@@ -1596,6 +1596,11 @@ public class IrJsCodegenBoxTestGenerated extends AbstractIrJsCodegenBoxTest {
                 KotlinTestUtils.assertAllTestsPresentByMetadataWithExcluded(this.getClass(), new File("compiler/testData/codegen/box/callableReference/function"), Pattern.compile("^(.+)\\.kt$"), null, TargetBackend.JS_IR, true);
             }
 
+            @TestMetadata("argumentTypes.kt")
+            public void testArgumentTypes() throws Exception {
+                runTest("compiler/testData/codegen/box/callableReference/function/argumentTypes.kt");
+            }
+
             @TestMetadata("booleanNotIntrinsic.kt")
             public void testBooleanNotIntrinsic() throws Exception {
                 runTest("compiler/testData/codegen/box/callableReference/function/booleanNotIntrinsic.kt");

js/js.tests/test/org/jetbrains/kotlin/js/test/semantics/JsCodegenBoxTestGenerated.java

@@ -1596,6 +1596,11 @@ public class JsCodegenBoxTestGenerated extends AbstractJsCodegenBoxTest {
                 KotlinTestUtils.assertAllTestsPresentByMetadataWithExcluded(this.getClass(), new File("compiler/testData/codegen/box/callableReference/function"), Pattern.compile("^(.+)\\.kt$"), null, TargetBackend.JS, true);
             }
 
+            @TestMetadata("argumentTypes.kt")
+            public void testArgumentTypes() throws Exception {
+                runTest("compiler/testData/codegen/box/callableReference/function/argumentTypes.kt");
+            }
+
             @TestMetadata("booleanNotIntrinsic.kt")
             public void testBooleanNotIntrinsic() throws Exception {
                 runTest("compiler/testData/codegen/box/callableReference/function/booleanNotIntrinsic.kt");