ReferencesSearch finds references of data class component functions in Java code

#KT-8808 Fixed

compiler/light-classes/src/org/jetbrains/kotlin/asJava/KotlinLightParameter.java

@@ -131,4 +131,8 @@ public class KotlinLightParameter extends LightParameter implements KotlinLightE
         JetParameter origin = getOrigin();
         return origin != null ? origin.getUseScope() : GlobalSearchScope.EMPTY_SCOPE;
     }
+
+    public KotlinLightMethod getMethod() {
+        return method;
+    }
 }

idea/idea-analysis/src/org/jetbrains/kotlin/idea/search/ideaExtensions/KotlinReferencesSearcher.kt

@@ -25,12 +25,14 @@ import com.intellij.psi.search.searches.ReferencesSearch
 import com.intellij.psi.util.PsiTreeUtil
 import com.intellij.util.Processor
 import org.jetbrains.kotlin.asJava.KotlinLightMethod
+import org.jetbrains.kotlin.asJava.KotlinLightParameter
 import org.jetbrains.kotlin.asJava.LightClassUtil
 import org.jetbrains.kotlin.asJava.namedUnwrappedElement
 import org.jetbrains.kotlin.idea.JetFileType
 import org.jetbrains.kotlin.idea.references.JetSimpleNameReference
 import org.jetbrains.kotlin.idea.search.KOTLIN_NAMED_ARGUMENT_SEARCH_CONTEXT
 import org.jetbrains.kotlin.idea.search.usagesSearch.UsagesSearchLocation
+import org.jetbrains.kotlin.idea.search.usagesSearch.dataClassComponentFunction
 import org.jetbrains.kotlin.idea.search.usagesSearch.getSpecialNamesToSearch
 import org.jetbrains.kotlin.idea.stubindex.JetSourceFilterScope
 import org.jetbrains.kotlin.idea.util.ProjectRootsUtil
@@ -159,6 +161,18 @@ public class KotlinReferencesSearcher : QueryExecutorBase<PsiReference, Referenc
                         searchNamedElement(queryParameters, PsiTreeUtil.getParentOfType<JetProperty>(declaration, javaClass<JetProperty>()))
                     }
                 }
+                is KotlinLightParameter -> {
+                    val componentFunctionDescriptor = element.getOrigin()?.dataClassComponentFunction()
+                    if (componentFunctionDescriptor != null) {
+                        val containingClass = element.method.containingClass
+                        val componentFunction = containingClass?.methods?.find {
+                            it.name == componentFunctionDescriptor.name.asString() && it.parameterList.parametersCount == 0
+                        }
+                        if (componentFunction != null) {
+                            searchNamedElement(queryParameters, componentFunction)
+                        }
+                    }
+                }
             }
         }
 

idea/idea-analysis/src/org/jetbrains/kotlin/idea/search/usagesSearch/searchHelpers.kt

@@ -25,6 +25,7 @@ import com.intellij.util.Processor
 import com.intellij.util.containers.ContainerUtil
 import org.jetbrains.kotlin.asJava.LightClassUtil
 import org.jetbrains.kotlin.asJava.LightClassUtil.PropertyAccessorsPsiMethods
+import org.jetbrains.kotlin.descriptors.FunctionDescriptor
 import org.jetbrains.kotlin.descriptors.ValueParameterDescriptor
 import org.jetbrains.kotlin.idea.caches.resolve.analyze
 import org.jetbrains.kotlin.idea.references.JetSimpleNameReference
@@ -45,8 +46,7 @@ import org.jetbrains.kotlin.psi.psiUtil.getStrictParentOfType
 import org.jetbrains.kotlin.resolve.BindingContext
 import org.jetbrains.kotlin.resolve.scopes.receivers.ClassReceiver
 import org.jetbrains.kotlin.utils.addToStdlib.singletonOrEmptyList
-import java.util.ArrayList
-import java.util.Collections
+import java.util.*
 
 val isTargetUsage = (PsiReference::matchesTarget).searchFilter
 
@@ -88,7 +88,7 @@ public fun PsiNamedElement.getSpecialNamesToSearch(): List<String> {
     return when {
         name == null || !Name.isValidIdentifier(name) -> Collections.emptyList<String>()
         this is JetParameter -> {
-            val componentFunctionName = this.dataClassComponentFunctionName()
+            val componentFunctionName = this.dataClassComponentFunction()?.name
             if (componentFunctionName == null) return Collections.emptyList<String>()
 
             return listOf(componentFunctionName.asString(), JetTokens.LPAR.getValue())
@@ -97,7 +97,7 @@ public fun PsiNamedElement.getSpecialNamesToSearch(): List<String> {
     }
 }
 
-fun JetParameter.dataClassComponentFunctionName(): Name? {
+fun JetParameter.dataClassComponentFunction(): FunctionDescriptor? {
     if (!hasValOrVar()) return null
 
     // Forcing full resolve of owner class: otherwise DATA_CLASS_COMPONENT_FUNCTION won't be calculated.
@@ -107,9 +107,7 @@ fun JetParameter.dataClassComponentFunctionName(): Name? {
 
     val context = this.analyze()
     val paramDescriptor = context[BindingContext.DECLARATION_TO_DESCRIPTOR, this] as? ValueParameterDescriptor
-    return context[BindingContext.DATA_CLASS_COMPONENT_FUNCTION, paramDescriptor]?.let {
-        it.getName()
-    }
+    return context[BindingContext.DATA_CLASS_COMPONENT_FUNCTION, paramDescriptor]
 }
 
 public abstract class UsagesSearchHelper<T : PsiNamedElement> {

idea/src/org/jetbrains/kotlin/idea/inspections/UnusedSymbolInspection.kt

@@ -159,7 +159,7 @@ public class UnusedSymbolInspection : AbstractKotlinInspection() {
                 if (declaration is JetProperty && declaration.isSerializationImplicitlyUsedField()) return
                 if (isCompanionObject && (declaration as JetObjectDeclaration).hasSerializationImplicitlyUsedField()) return
                 // properties can be referred by component1/component2, which is too expensive to search, don't mark them as unused
-                if (declaration is JetParameter && declaration.dataClassComponentFunctionName() != null) return
+                if (declaration is JetParameter && declaration.dataClassComponentFunction() != null) return
 
                 // Main checks: finding reference usages && text usages
                 if (hasNonTrivialUsages(declaration)) return

idea/testData/safeDelete/deleteValueParameter/kotlinValueParameterWithJava/dataClassComponent.java

@@ -0,0 +1,7 @@
+package test;
+
+public class A {
+    public void usage(RemData p) {
+        System.out.println(p.component1());
+    }
+}

idea/testData/safeDelete/deleteValueParameter/kotlinValueParameterWithJava/dataClassComponent.kt

@@ -0,0 +1,3 @@
+package test
+
+data public class RemData(val remo<caret>vable: Int)

idea/testData/safeDelete/deleteValueParameter/kotlinValueParameterWithJava/dataClassComponent.kt.messages

@@ -0,0 +1 @@
+parameter removable has 1 usage that is not safe to delete.

idea/tests/org/jetbrains/kotlin/safeDelete/JetSafeDeleteTestGenerated.java

@@ -1081,6 +1081,12 @@ public class JetSafeDeleteTestGenerated extends AbstractJetSafeDeleteTest {
             JetTestUtils.assertAllTestsPresentByMetadata(this.getClass(), new File("idea/testData/safeDelete/deleteValueParameter/kotlinValueParameterWithJava"), Pattern.compile("^(.+)\\.kt$"), true);
         }
 
+        @TestMetadata("dataClassComponent.kt")
+        public void testDataClassComponent() throws Exception {
+            String fileName = JetTestUtils.navigationMetadata("idea/testData/safeDelete/deleteValueParameter/kotlinValueParameterWithJava/dataClassComponent.kt");
+            doValueParameterTestWithJava(fileName);
+        }
+
         @TestMetadata("hierarchyWithSafeUsages1.kt")
         public void testHierarchyWithSafeUsages1() throws Exception {
             String fileName = JetTestUtils.navigationMetadata("idea/testData/safeDelete/deleteValueParameter/kotlinValueParameterWithJava/hierarchyWithSafeUsages1.kt");