FIR: introduce Java vs Kotlin class conflicts checker #KT-44441 Fixed

analysis/low-level-api-fir/src/org/jetbrains/kotlin/analysis/low/level/api/fir/sessions/LLFirSessionFactory.kt

@@ -29,6 +29,7 @@ import org.jetbrains.kotlin.fir.analysis.checkersComponent
 import org.jetbrains.kotlin.fir.analysis.extensions.additionalCheckers
 import org.jetbrains.kotlin.fir.backend.jvm.FirJvmTypeMapper
 import org.jetbrains.kotlin.fir.extensions.*
+import org.jetbrains.kotlin.fir.java.JavaSymbolProvider
 import org.jetbrains.kotlin.fir.resolve.providers.FirDependenciesSymbolProvider
 import org.jetbrains.kotlin.fir.resolve.providers.FirProvider
 import org.jetbrains.kotlin.fir.resolve.providers.FirSymbolProvider
@@ -120,6 +121,7 @@ internal object LLFirSessionFactory {
                     }
             }
 
+            val javaSymbolProvider = createJavaSymbolProvider(this, moduleData, project, contentScope)
             register(
                 FirSymbolProvider::class,
                 LLFirModuleWithDependenciesSymbolProvider(
@@ -128,10 +130,11 @@ internal object LLFirSessionFactory {
                     providers = listOfNotNull(
                         provider.symbolProvider,
                         switchableExtensionDeclarationsSymbolProvider,
-                        createJavaSymbolProvider(this, moduleData, project, contentScope)
+                        javaSymbolProvider,
                     ),
                 )
             )
+            register(JavaSymbolProvider::class, javaSymbolProvider)
 
             register(FirDependenciesSymbolProvider::class, dependencyProvider)
             register(FirJvmTypeMapper::class, FirJvmTypeMapper(this))
@@ -210,6 +213,7 @@ internal object LLFirSessionFactory {
                 )
             }
 
+            val javaSymbolProvider = createJavaSymbolProvider(this, moduleData, project, contentScope)
             register(
                 FirSymbolProvider::class,
                 LLFirModuleWithDependenciesSymbolProvider(
@@ -217,10 +221,11 @@ internal object LLFirSessionFactory {
                     dependencyProvider,
                     providers = listOf(
                         provider.symbolProvider,
-                        createJavaSymbolProvider(this, moduleData, project, contentScope),
+                        javaSymbolProvider,
                     ),
                 )
             )
+            register(JavaSymbolProvider::class, javaSymbolProvider)
 
             register(FirDependenciesSymbolProvider::class, dependencyProvider)
             register(FirJvmTypeMapper::class, FirJvmTypeMapper(this))

compiler/fir/checkers/checkers.jvm/src/org/jetbrains/kotlin/fir/analysis/jvm/checkers/JvmDeclarationCheckers.kt

@@ -28,7 +28,8 @@ object JvmDeclarationCheckers : DeclarationCheckers() {
     override val regularClassCheckers: Set<FirRegularClassChecker>
         get() = setOf(
             FirJvmRecordChecker,
-            FirJvmInlineApplicabilityChecker
+            FirJvmInlineApplicabilityChecker,
+            FirJvmConflictsChecker,
         )
 
     override val propertyCheckers: Set<FirPropertyChecker>

compiler/fir/checkers/checkers.jvm/src/org/jetbrains/kotlin/fir/analysis/jvm/checkers/declaration/FirJvmConflictsChecker.kt

@@ -0,0 +1,24 @@
+/*
+ * Copyright 2010-2022 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.
+ */
+
+package org.jetbrains.kotlin.fir.analysis.jvm.checkers.declaration
+
+import org.jetbrains.kotlin.diagnostics.DiagnosticReporter
+import org.jetbrains.kotlin.diagnostics.reportOn
+import org.jetbrains.kotlin.fir.analysis.checkers.context.CheckerContext
+import org.jetbrains.kotlin.fir.analysis.checkers.declaration.FirRegularClassChecker
+import org.jetbrains.kotlin.fir.analysis.diagnostics.FirErrors
+import org.jetbrains.kotlin.fir.declarations.FirRegularClass
+import org.jetbrains.kotlin.fir.declarations.utils.classId
+import org.jetbrains.kotlin.fir.java.javaSymbolProvider
+
+object FirJvmConflictsChecker : FirRegularClassChecker() {
+    override fun check(declaration: FirRegularClass, context: CheckerContext, reporter: DiagnosticReporter) {
+        val javaSymbol = context.session.javaSymbolProvider.getClassLikeSymbolByClassId(declaration.classId) ?: return
+        reporter.reportOn(
+            declaration.source, FirErrors.PACKAGE_OR_CLASSIFIER_REDECLARATION, listOf(declaration.symbol, javaSymbol), context
+        )
+    }
+}

compiler/fir/entrypoint/src/org/jetbrains/kotlin/fir/session/ComponentsContainers.kt

@@ -5,9 +5,6 @@
 
 package org.jetbrains.kotlin.fir.session
 
-import com.intellij.psi.PsiFile
-import org.jetbrains.kotlin.KtNodeTypes
-import org.jetbrains.kotlin.KtPsiSourceElement
 import org.jetbrains.kotlin.KtSourceElement
 import org.jetbrains.kotlin.config.JvmAnalysisFlags
 import org.jetbrains.kotlin.config.LanguageVersionSettings
@@ -30,7 +27,6 @@ import org.jetbrains.kotlin.fir.resolve.calls.ConeCallConflictResolverFactory
 import org.jetbrains.kotlin.fir.resolve.calls.FirSyntheticNamesProvider
 import org.jetbrains.kotlin.fir.resolve.calls.jvm.JvmCallConflictResolverFactory
 import org.jetbrains.kotlin.fir.resolve.inference.InferenceComponents
-import org.jetbrains.kotlin.fir.resolve.providers.firProvider
 import org.jetbrains.kotlin.fir.resolve.providers.impl.FirQualifierResolverImpl
 import org.jetbrains.kotlin.fir.resolve.providers.impl.FirTypeResolverImpl
 import org.jetbrains.kotlin.fir.resolve.transformers.FirPhaseCheckingPhaseManager

compiler/fir/entrypoint/src/org/jetbrains/kotlin/fir/session/FirSessionFactory.kt

@@ -197,6 +197,7 @@ object FirSessionFactory {
 
             val dependenciesSymbolProvider = FirDependenciesSymbolProviderImpl(this)
             val generatedSymbolsProvider = FirSwitchableExtensionDeclarationsSymbolProvider.create(this)
+            val javaSymbolProvider = JavaSymbolProvider(this, projectEnvironment.getFirJavaFacade(this, moduleData, javaSourcesScope))
             register(
                 FirSymbolProvider::class,
                 FirCompositeSymbolProvider(
@@ -206,12 +207,13 @@ object FirSessionFactory {
                         *(incrementalCompilationContext?.previousFirSessionsSymbolProviders?.toTypedArray() ?: emptyArray()),
                         symbolProviderForBinariesFromIncrementalCompilation,
                         generatedSymbolsProvider,
-                        JavaSymbolProvider(this, projectEnvironment.getFirJavaFacade(this, moduleData, javaSourcesScope)),
+                        javaSymbolProvider,
                         dependenciesSymbolProvider,
                         optionalAnnotationClassesProviderForBinariesFromIncrementalCompilation,
                     )
                 )
             )
+            register(JavaSymbolProvider::class, javaSymbolProvider)
 
             generatedSymbolsProvider?.let { register(FirSwitchableExtensionDeclarationsSymbolProvider::class, it) }
 

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

@@ -57,3 +57,6 @@ class JavaSymbolProvider(
     @OptIn(FirSymbolProviderInternals::class)
     override fun getTopLevelPropertySymbolsTo(destination: MutableList<FirPropertySymbol>, packageFqName: FqName, name: Name) {}
 }
+
+val FirSession.javaSymbolProvider: JavaSymbolProvider by FirSession.sessionComponentAccessor()
+

compiler/testData/diagnostics/foreignAnnotationsTests/java8Tests/jsr305/overrideWithTypeUseInClasspath.fir.kt

@@ -0,0 +1,89 @@
+// SOURCE_RETENTION_ANNOTATIONS
+// !DIAGNOSTICS: -UNUSED_VARIABLE -UNUSED_PARAMETER
+// JSR305_GLOBAL_REPORT: strict
+
+// FILE: spr/Nullable.java
+package spr;
+
+import java.lang.annotation.Documented;
+import java.lang.annotation.ElementType;
+import java.lang.annotation.Retention;
+import java.lang.annotation.RetentionPolicy;
+import java.lang.annotation.Target;
+import javax.annotation.Nonnull;
+import javax.annotation.meta.TypeQualifierNickname;
+import javax.annotation.meta.When;
+
+@Target({ElementType.TYPE_USE})
+@Retention(RetentionPolicy.RUNTIME)
+@Documented
+@Nonnull(when = When.MAYBE)
+@TypeQualifierNickname
+public @interface Nullable {
+}
+
+// FILE: spr/NotNull.java
+package spr;
+
+import java.lang.annotation.Documented;
+import java.lang.annotation.ElementType;
+import java.lang.annotation.Retention;
+import java.lang.annotation.RetentionPolicy;
+import java.lang.annotation.Target;
+import javax.annotation.Nonnull;
+import javax.annotation.meta.TypeQualifierNickname;
+import javax.annotation.meta.When;
+
+@Target({ElementType.METHOD, ElementType.PARAMETER})
+@Retention(RetentionPolicy.RUNTIME)
+@Documented
+@Nonnull
+@TypeQualifierNickname
+public @interface NotNull {
+}
+
+
+// FILE: J1.java
+
+import spr.*;
+
+public interface J1<T> {
+    @Nullable
+    T getFoo();
+}
+
+// FILE: J2.java
+
+import spr.*;
+
+public class J2 implements J1<String> {
+    @NotNull
+    public String getFoo() { return ""; }
+}
+
+
+// FILE: Nonnull.kt
+package spr
+import javax.annotation.meta.TypeQualifierNickname
+import javax.annotation.Nonnull;
+
+// This is a crucial part: NotNull defined in Java has no TYPE_USE target, so it has been applied only to the method
+// While on use-site (main.kt) spr.NotNull shall be resolved to Kotlin version with TYPE among target
+// So, even while our annotation is type use, we still should consider situation when it's applied to the method/parameter, but not to type
+@Target(
+    AnnotationTarget.FUNCTION,
+    AnnotationTarget.PROPERTY_GETTER,
+    AnnotationTarget.PROPERTY_SETTER,
+    AnnotationTarget.VALUE_PARAMETER,
+    AnnotationTarget.TYPE,
+)
+@Retention(AnnotationRetention.RUNTIME)
+@Nonnull
+@TypeQualifierNickname
+annotation class <!PACKAGE_OR_CLASSIFIER_REDECLARATION!>NotNull<!>
+
+// FILE: main.kt
+
+fun bar(j2: J2) {
+    j2.foo.length // `j2.foo` is not nullable
+}

compiler/testData/diagnostics/foreignAnnotationsTests/java8Tests/jsr305/overrideWithTypeUseInClasspath.kt

@@ -1,4 +1,4 @@
-// FIR_IDENTICAL
+// SOURCE_RETENTION_ANNOTATIONS
 // !DIAGNOSTICS: -UNUSED_VARIABLE -UNUSED_PARAMETER
 // JSR305_GLOBAL_REPORT: strict
 

compiler/testData/diagnostics/foreignAnnotationsTests/java8Tests/jsr305/overrideWithTypeUseInClasspathWithArray.fir.kt

@@ -0,0 +1,89 @@
+// SOURCE_RETENTION_ANNOTATIONS
+// !DIAGNOSTICS: -UNUSED_VARIABLE -UNUSED_PARAMETER
+// JSR305_GLOBAL_REPORT: strict
+// !LANGUAGE: +TypeEnhancementImprovementsInStrictMode
+
+// FILE: spr/Nullable.java
+package spr;
+
+import java.lang.annotation.Documented;
+import java.lang.annotation.ElementType;
+import java.lang.annotation.Retention;
+import java.lang.annotation.RetentionPolicy;
+import java.lang.annotation.Target;
+import javax.annotation.Nonnull;
+import javax.annotation.meta.TypeQualifierNickname;
+import javax.annotation.meta.When;
+
+@Target({ElementType.TYPE_USE})
+@Retention(RetentionPolicy.RUNTIME)
+@Documented
+@Nonnull(when = When.MAYBE)
+@TypeQualifierNickname
+public @interface Nullable {
+}
+
+// FILE: spr/NotNull.java
+package spr;
+
+import java.lang.annotation.Documented;
+import java.lang.annotation.ElementType;
+import java.lang.annotation.Retention;
+import java.lang.annotation.RetentionPolicy;
+import java.lang.annotation.Target;
+import javax.annotation.Nonnull;
+import javax.annotation.meta.TypeQualifierNickname;
+import javax.annotation.meta.When;
+
+@Target({ElementType.METHOD, ElementType.PARAMETER})
+@Retention(RetentionPolicy.RUNTIME)
+@Documented
+@Nonnull
+@TypeQualifierNickname
+public @interface NotNull {
+}
+
+
+// FILE: J1.java
+
+import spr.*;
+
+public interface J1<T> {
+    T @Nullable [] getFoo();
+}
+
+// FILE: J2.java
+
+import spr.*;
+
+public class J2 implements J1<String> {
+    @NotNull
+    public String[] getFoo() { return null; }
+}
+
+
+// FILE: Nonnull.kt
+package spr
+import javax.annotation.meta.TypeQualifierNickname
+import javax.annotation.Nonnull;
+
+// This is a crucial part: NotNull defined in Java has no TYPE_USE target, so it has been applied only to the method
+// While on use-site (main.kt) spr.NotNull shall be resolved to Kotlin version with TYPE among target
+// So, even while our annotation is type use, we still should consider situation when it's applied to the method/parameter, but not to type
+@Target(
+    AnnotationTarget.FUNCTION,
+    AnnotationTarget.PROPERTY_GETTER,
+    AnnotationTarget.PROPERTY_SETTER,
+    AnnotationTarget.VALUE_PARAMETER,
+    AnnotationTarget.TYPE,
+)
+@Retention(AnnotationRetention.RUNTIME)
+@Nonnull
+@TypeQualifierNickname
+annotation class <!PACKAGE_OR_CLASSIFIER_REDECLARATION!>NotNull<!>
+
+// FILE: main.kt
+
+fun bar(j2: J2) {
+    j2.foo<!UNSAFE_CALL!>.<!>get(0).length // `j2.foo` is not nullable
+}

compiler/testData/diagnostics/foreignAnnotationsTests/java8Tests/jsr305/overrideWithTypeUseInClasspathWithArray.kt

@@ -1,4 +1,3 @@
-// FIR_IDENTICAL
 // SOURCE_RETENTION_ANNOTATIONS
 // !DIAGNOSTICS: -UNUSED_VARIABLE -UNUSED_PARAMETER
 // JSR305_GLOBAL_REPORT: strict

compiler/testData/diagnostics/tests/j+k/brokenCode/classDuplicates.fir.kt

@@ -0,0 +1,13 @@
+// FILE: Hello.kt
+private class <!PACKAGE_OR_CLASSIFIER_REDECLARATION!>Hello<!>()
+{
+    val a = 4
+}
+
+fun test() {
+    // no exception is thrown (see KT-3897)
+    Hello().a
+}
+
+// FILE: Hello.java
+public class Hello {}

compiler/testData/diagnostics/tests/j+k/brokenCode/classDuplicates.kt

@@ -1,4 +1,3 @@
-// FIR_IDENTICAL
 // FILE: Hello.kt
 private class Hello()
 {