[FIR] JavaTypeParameterStack: allow nullable return from get

It is not always possible to have the correct mapping,
at least on the Analysis API side

^KT-66530 Fixed

analysis/analysis-api-fir/tests-gen/org/jetbrains/kotlin/analysis/api/fir/test/cases/generated/cases/components/psiTypeProvider/FirIdeDependentAnalysisSourceModuleAnalysisApiKtTypeByPsiTypeProviderTestGenerated.java

@@ -57,6 +57,24 @@ public class FirIdeDependentAnalysisSourceModuleAnalysisApiKtTypeByPsiTypeProvid
     runTest("analysis/analysis-api/testData/components/psiTypeProvider/psiType/asKtType/extends.kt");
   }
 
+  @Test
+  @TestMetadata("methodTypeParameterWithKotlinUseSite.kt")
+  public void testMethodTypeParameterWithKotlinUseSite() {
+    runTest("analysis/analysis-api/testData/components/psiTypeProvider/psiType/asKtType/methodTypeParameterWithKotlinUseSite.kt");
+  }
+
+  @Test
+  @TestMetadata("methodTypeParameterWithMethodUseSite.kt")
+  public void testMethodTypeParameterWithMethodUseSite() {
+    runTest("analysis/analysis-api/testData/components/psiTypeProvider/psiType/asKtType/methodTypeParameterWithMethodUseSite.kt");
+  }
+
+  @Test
+  @TestMetadata("methodTypeParameterWithTypeParameterUseSite.kt")
+  public void testMethodTypeParameterWithTypeParameterUseSite() {
+    runTest("analysis/analysis-api/testData/components/psiTypeProvider/psiType/asKtType/methodTypeParameterWithTypeParameterUseSite.kt");
+  }
+
   @Test
   @TestMetadata("methodTypeParameters.kt")
   public void testMethodTypeParameters() {
@@ -81,6 +99,18 @@ public class FirIdeDependentAnalysisSourceModuleAnalysisApiKtTypeByPsiTypeProvid
     runTest("analysis/analysis-api/testData/components/psiTypeProvider/psiType/asKtType/primitive.kt");
   }
 
+  @Test
+  @TestMetadata("typeParameterWithKotlinUseSite.kt")
+  public void testTypeParameterWithKotlinUseSite() {
+    runTest("analysis/analysis-api/testData/components/psiTypeProvider/psiType/asKtType/typeParameterWithKotlinUseSite.kt");
+  }
+
+  @Test
+  @TestMetadata("typeParameterWithMethodUseSite.kt")
+  public void testTypeParameterWithMethodUseSite() {
+    runTest("analysis/analysis-api/testData/components/psiTypeProvider/psiType/asKtType/typeParameterWithMethodUseSite.kt");
+  }
+
   @Test
   @TestMetadata("typeParameters.kt")
   public void testTypeParameters() {

analysis/analysis-api-fir/tests-gen/org/jetbrains/kotlin/analysis/api/fir/test/cases/generated/cases/components/psiTypeProvider/FirIdeNormalAnalysisSourceModuleAnalysisApiKtTypeByPsiTypeProviderTestGenerated.java

@@ -57,6 +57,24 @@ public class FirIdeNormalAnalysisSourceModuleAnalysisApiKtTypeByPsiTypeProviderT
     runTest("analysis/analysis-api/testData/components/psiTypeProvider/psiType/asKtType/extends.kt");
   }
 
+  @Test
+  @TestMetadata("methodTypeParameterWithKotlinUseSite.kt")
+  public void testMethodTypeParameterWithKotlinUseSite() {
+    runTest("analysis/analysis-api/testData/components/psiTypeProvider/psiType/asKtType/methodTypeParameterWithKotlinUseSite.kt");
+  }
+
+  @Test
+  @TestMetadata("methodTypeParameterWithMethodUseSite.kt")
+  public void testMethodTypeParameterWithMethodUseSite() {
+    runTest("analysis/analysis-api/testData/components/psiTypeProvider/psiType/asKtType/methodTypeParameterWithMethodUseSite.kt");
+  }
+
+  @Test
+  @TestMetadata("methodTypeParameterWithTypeParameterUseSite.kt")
+  public void testMethodTypeParameterWithTypeParameterUseSite() {
+    runTest("analysis/analysis-api/testData/components/psiTypeProvider/psiType/asKtType/methodTypeParameterWithTypeParameterUseSite.kt");
+  }
+
   @Test
   @TestMetadata("methodTypeParameters.kt")
   public void testMethodTypeParameters() {
@@ -81,6 +99,18 @@ public class FirIdeNormalAnalysisSourceModuleAnalysisApiKtTypeByPsiTypeProviderT
     runTest("analysis/analysis-api/testData/components/psiTypeProvider/psiType/asKtType/primitive.kt");
   }
 
+  @Test
+  @TestMetadata("typeParameterWithKotlinUseSite.kt")
+  public void testTypeParameterWithKotlinUseSite() {
+    runTest("analysis/analysis-api/testData/components/psiTypeProvider/psiType/asKtType/typeParameterWithKotlinUseSite.kt");
+  }
+
+  @Test
+  @TestMetadata("typeParameterWithMethodUseSite.kt")
+  public void testTypeParameterWithMethodUseSite() {
+    runTest("analysis/analysis-api/testData/components/psiTypeProvider/psiType/asKtType/typeParameterWithMethodUseSite.kt");
+  }
+
   @Test
   @TestMetadata("typeParameters.kt")
   public void testTypeParameters() {

analysis/analysis-api-impl-base/tests/org/jetbrains/kotlin/analysis/api/impl/base/test/cases/components/psiTypeProvider/AbstractAnalysisApiKtTypeByPsiTypeProviderTest.kt

@@ -5,13 +5,13 @@
 
 package org.jetbrains.kotlin.analysis.api.impl.base.test.cases.components.psiTypeProvider
 
-import com.intellij.psi.PsiJavaFile
+import com.intellij.psi.PsiElement
 import com.intellij.psi.PsiMethod
-import com.intellij.psi.util.PsiTreeUtil
 import org.jetbrains.kotlin.analysis.test.framework.base.AbstractAnalysisApiBasedTest
 import org.jetbrains.kotlin.analysis.test.framework.project.structure.ktModuleProvider
 import org.jetbrains.kotlin.analysis.test.framework.services.expressionMarkerProvider
 import org.jetbrains.kotlin.analysis.test.framework.utils.executeOnPooledThreadInReadAction
+import org.jetbrains.kotlin.analysis.utils.printer.parentOfType
 import org.jetbrains.kotlin.psi.KtFile
 import org.jetbrains.kotlin.test.model.TestModule
 import org.jetbrains.kotlin.test.services.TestServices
@@ -21,19 +21,14 @@ import org.jetbrains.kotlin.types.Variance
 
 abstract class AbstractAnalysisApiKtTypeByPsiTypeProviderTest : AbstractAnalysisApiBasedTest() {
     override fun doTestByMainFile(mainFile: KtFile, mainModule: TestModule, testServices: TestServices) {
-        val psiMethod = testServices.moduleStructure.modules.map { module ->
+        val (psiMethod, useSitePosition) = getTestDataContext(testServices)
-            val psiFiles = testServices.ktModuleProvider.getModuleFiles(module).filterIsInstance<PsiJavaFile>()
-            val javaFile = psiFiles.first()
-            val offset = testServices.expressionMarkerProvider.getCaretPosition(javaFile)
-            PsiTreeUtil.getParentOfType(javaFile.findElementAt(offset), PsiMethod::class.java)
-        }.single()!!
 
         val actual = buildString {
             executeOnPooledThreadInReadAction {
                 analyseForTest(mainFile) {
                     val returnType = psiMethod.returnType
                     testServices.assertions.assertNotNull(returnType)
-                    val asKtTypeSuper = returnType!!.asKtType(psiMethod)!!
+                    val asKtTypeSuper = returnType!!.asKtType(useSitePosition ?: psiMethod)!!
                     appendLine("PsiType: $returnType")
                     appendLine("KtType: ${asKtTypeSuper.render(position = Variance.OUT_VARIANCE)}")
                 }
@@ -43,3 +38,29 @@ abstract class AbstractAnalysisApiKtTypeByPsiTypeProviderTest : AbstractAnalysis
         testServices.assertions.assertEqualsToTestDataFileSibling(actual)
     }
 }
+
+private data class TestDataContext(val targetMethod: PsiMethod, val useSitePosition: PsiElement?)
+
+private fun getTestDataContext(testServices: TestServices): TestDataContext {
+    var psiMethod: PsiMethod? = null
+    var useSitePosition: PsiElement? = null
+
+    testServices.moduleStructure.modules.forEach { module ->
+        val psiFiles = testServices.ktModuleProvider.getModuleFiles(module)
+        for (psiFile in psiFiles) {
+            val targetOffset = testServices.expressionMarkerProvider.getCaretPositionOrNull(psiFile)
+            if (targetOffset != null) {
+                if (psiMethod != null) error("Only one target method is expected")
+                psiMethod = psiFile.findElementAt(targetOffset)?.parentOfType<PsiMethod>(withSelf = true)
+            }
+
+            val useSiteOffset = testServices.expressionMarkerProvider.getCaretPositionOrNull(psiFile, caretTag = "useSite")
+            if (useSiteOffset != null) {
+                if (useSitePosition != null) error("Only one target method is expected")
+                useSitePosition = psiFile.findElementAt(useSiteOffset)?.parentOfType<PsiElement>(withSelf = true)
+            }
+        }
+    }
+
+    return TestDataContext(psiMethod ?: error("Target method is not found"), useSitePosition)
+}

analysis/analysis-api-standalone/tests-gen/org/jetbrains/kotlin/analysis/api/standalone/fir/test/cases/generated/cases/components/psiTypeProvider/FirStandaloneNormalAnalysisSourceModuleAnalysisApiKtTypeByPsiTypeProviderTestGenerated.java

@@ -57,6 +57,24 @@ public class FirStandaloneNormalAnalysisSourceModuleAnalysisApiKtTypeByPsiTypePr
     runTest("analysis/analysis-api/testData/components/psiTypeProvider/psiType/asKtType/extends.kt");
   }
 
+  @Test
+  @TestMetadata("methodTypeParameterWithKotlinUseSite.kt")
+  public void testMethodTypeParameterWithKotlinUseSite() {
+    runTest("analysis/analysis-api/testData/components/psiTypeProvider/psiType/asKtType/methodTypeParameterWithKotlinUseSite.kt");
+  }
+
+  @Test
+  @TestMetadata("methodTypeParameterWithMethodUseSite.kt")
+  public void testMethodTypeParameterWithMethodUseSite() {
+    runTest("analysis/analysis-api/testData/components/psiTypeProvider/psiType/asKtType/methodTypeParameterWithMethodUseSite.kt");
+  }
+
+  @Test
+  @TestMetadata("methodTypeParameterWithTypeParameterUseSite.kt")
+  public void testMethodTypeParameterWithTypeParameterUseSite() {
+    runTest("analysis/analysis-api/testData/components/psiTypeProvider/psiType/asKtType/methodTypeParameterWithTypeParameterUseSite.kt");
+  }
+
   @Test
   @TestMetadata("methodTypeParameters.kt")
   public void testMethodTypeParameters() {
@@ -81,6 +99,18 @@ public class FirStandaloneNormalAnalysisSourceModuleAnalysisApiKtTypeByPsiTypePr
     runTest("analysis/analysis-api/testData/components/psiTypeProvider/psiType/asKtType/primitive.kt");
   }
 
+  @Test
+  @TestMetadata("typeParameterWithKotlinUseSite.kt")
+  public void testTypeParameterWithKotlinUseSite() {
+    runTest("analysis/analysis-api/testData/components/psiTypeProvider/psiType/asKtType/typeParameterWithKotlinUseSite.kt");
+  }
+
+  @Test
+  @TestMetadata("typeParameterWithMethodUseSite.kt")
+  public void testTypeParameterWithMethodUseSite() {
+    runTest("analysis/analysis-api/testData/components/psiTypeProvider/psiType/asKtType/typeParameterWithMethodUseSite.kt");
+  }
+
   @Test
   @TestMetadata("typeParameters.kt")
   public void testTypeParameters() {

analysis/analysis-api/testData/components/psiTypeProvider/psiType/asKtType/methodTypeParameterWithKotlinUseSite.kt

@@ -0,0 +1,9 @@
+// FILE: KotlinClass.kt
+class Kotlin<caret_useSite>Class
+
+// FILE: A.java
+class JavaClass {
+    <TYPE> TYPE ma<caret>terialize() {
+        return null;
+    }
+}

analysis/analysis-api/testData/components/psiTypeProvider/psiType/asKtType/methodTypeParameterWithKotlinUseSite.txt

@@ -0,0 +1,2 @@
+PsiType: PsiType:TYPE
+KtType: TYPE

analysis/analysis-api/testData/components/psiTypeProvider/psiType/asKtType/methodTypeParameterWithMethodUseSite.kt

@@ -0,0 +1,9 @@
+// FILE: KotlinClass.kt
+class KotlinClass
+
+// FILE: A.java
+class JavaClass {
+    <TYPE> TYPE ma<caret>teria<caret_useSite>lize() {
+        return null;
+    }
+}

analysis/analysis-api/testData/components/psiTypeProvider/psiType/asKtType/methodTypeParameterWithMethodUseSite.txt

@@ -0,0 +1,2 @@
+PsiType: PsiType:TYPE
+KtType: TYPE?

analysis/analysis-api/testData/components/psiTypeProvider/psiType/asKtType/methodTypeParameterWithTypeParameterUseSite.kt

@@ -0,0 +1,9 @@
+// FILE: KotlinClass.kt
+class KotlinClass
+
+// FILE: A.java
+class JavaClass {
+    <TY<caret_useSite>PE> TYPE ma<caret>terialize() {
+        return null;
+    }
+}

analysis/analysis-api/testData/components/psiTypeProvider/psiType/asKtType/methodTypeParameterWithTypeParameterUseSite.txt

@@ -0,0 +1,2 @@
+PsiType: PsiType:TYPE
+KtType: TYPE

analysis/analysis-api/testData/components/psiTypeProvider/psiType/asKtType/typeParameterWithKotlinUseSite.kt

@@ -0,0 +1,7 @@
+// FILE: KotlinClass.kt
+class Kotlin<caret_useSite>Class
+
+// FILE: A.java
+public interface A<T> {
+    T f<caret>oo();
+}

analysis/analysis-api/testData/components/psiTypeProvider/psiType/asKtType/typeParameterWithKotlinUseSite.txt

@@ -0,0 +1,2 @@
+PsiType: PsiType:T
+KtType: T

analysis/analysis-api/testData/components/psiTypeProvider/psiType/asKtType/typeParameterWithMethodUseSite.kt

@@ -0,0 +1,7 @@
+// FILE: KotlinClass.kt
+class KotlinClass
+
+// FILE: A.java
+public interface A<T> {
+    T f<caret>o<caret_useSite>o();
+}

analysis/analysis-api/testData/components/psiTypeProvider/psiType/asKtType/typeParameterWithMethodUseSite.txt

@@ -0,0 +1,2 @@
+PsiType: PsiType:T
+KtType: T?

compiler/fir/java/src/org/jetbrains/kotlin/fir/java/JavaTypeConversion.kt

@@ -1,5 +1,5 @@
 /*
- * Copyright 2010-2021 JetBrains s.r.o. and Kotlin Programming Language contributors.
+ * Copyright 2010-2024 JetBrains s.r.o. and Kotlin Programming Language contributors.
  * Use of this source code is governed by the Apache 2.0 license that can be found in the license/LICENSE.txt file.
  */
 
@@ -10,6 +10,7 @@ import org.jetbrains.kotlin.fir.FirSession
 import org.jetbrains.kotlin.fir.diagnostics.ConeSimpleDiagnostic
 import org.jetbrains.kotlin.fir.diagnostics.DiagnosticKind
 import org.jetbrains.kotlin.fir.java.enhancement.readOnlyToMutable
+import org.jetbrains.kotlin.fir.resolve.diagnostics.ConeUnresolvedNameError
 import org.jetbrains.kotlin.fir.resolve.toFirRegularClassSymbol
 import org.jetbrains.kotlin.fir.types.*
 import org.jetbrains.kotlin.fir.types.builder.buildResolvedTypeRef
@@ -214,7 +215,11 @@ private fun JavaClassifierType.toConeKotlinTypeForFlexibleBound(
 
         is JavaTypeParameter -> {
             val symbol = javaTypeParameterStack[classifier]
-            ConeTypeParameterTypeImpl(symbol.toLookupTag(), isNullable = lowerBound != null, attributes)
+            if (symbol != null) {
+                ConeTypeParameterTypeImpl(symbol.toLookupTag(), isNullable = lowerBound != null, attributes)
+            } else {
+                ConeErrorType(ConeUnresolvedNameError(classifier.name))
+            }
         }
 
         null -> {

compiler/fir/java/src/org/jetbrains/kotlin/fir/java/MutableJavaTypeParameterStack.kt

@@ -1,5 +1,5 @@
 /*
- * Copyright 2010-2023 JetBrains s.r.o. and Kotlin Programming Language contributors.
+ * Copyright 2010-2024 JetBrains s.r.o. and Kotlin Programming Language contributors.
  * Use of this source code is governed by the Apache 2.0 license that can be found in the license/LICENSE.txt file.
  */
 
@@ -19,9 +19,8 @@ class MutableJavaTypeParameterStack : JavaTypeParameterStack() {
         typeParameterMap += javaTypeParameterStack.typeParameterMap
     }
 
-    override operator fun get(javaTypeParameter: JavaTypeParameter): FirTypeParameterSymbol {
+    override operator fun get(javaTypeParameter: JavaTypeParameter): FirTypeParameterSymbol? {
         return typeParameterMap[javaTypeParameter]
-            ?: throw IllegalArgumentException("Cannot find Java type parameter $javaTypeParameter in stack")
     }
 
     override operator fun iterator(): Iterator<Map.Entry<JavaTypeParameter, FirTypeParameterSymbol>> {
@@ -31,14 +30,14 @@ class MutableJavaTypeParameterStack : JavaTypeParameterStack() {
     fun snapshot(): JavaTypeParameterStack {
         val snapshot = typeParameterMap.toMap()
         return object : JavaTypeParameterStack() {
-            override fun get(javaTypeParameter: JavaTypeParameter): FirTypeParameterSymbol = snapshot.getValue(javaTypeParameter)
+            override fun get(javaTypeParameter: JavaTypeParameter): FirTypeParameterSymbol? = snapshot[javaTypeParameter]
             override fun iterator(): Iterator<Map.Entry<JavaTypeParameter, FirTypeParameterSymbol>> = snapshot.iterator()
         }
     }
 }
 
 abstract class JavaTypeParameterStack : Iterable<Map.Entry<JavaTypeParameter, FirTypeParameterSymbol>> {
-    abstract operator fun get(javaTypeParameter: JavaTypeParameter): FirTypeParameterSymbol
+    abstract operator fun get(javaTypeParameter: JavaTypeParameter): FirTypeParameterSymbol?
 
     companion object {
         val EMPTY: JavaTypeParameterStack = MutableJavaTypeParameterStack()