Unused symbol: remove forced "used" from actual declarations

Now we really check whether actual declaration has usages
(in expect or actual code) or not
Related to KT-17512
Related to KT-15666

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

@@ -50,7 +50,9 @@ import org.jetbrains.kotlin.idea.imports.importableFqName
 import org.jetbrains.kotlin.idea.quickfix.RemoveUnusedFunctionParameterFix
 import org.jetbrains.kotlin.idea.references.mainReference
 import org.jetbrains.kotlin.idea.references.resolveMainReferenceToDescriptors
+import org.jetbrains.kotlin.idea.search.ideaExtensions.KotlinReferencesSearchParameters
 import org.jetbrains.kotlin.idea.search.isCheapEnoughToSearchConsideringOperators
+import org.jetbrains.kotlin.idea.search.projectScope
 import org.jetbrains.kotlin.idea.search.usagesSearch.dataClassComponentFunction
 import org.jetbrains.kotlin.idea.search.usagesSearch.getAccessorNames
 import org.jetbrains.kotlin.idea.search.usagesSearch.getClassNameForCompanionObject
@@ -190,7 +192,8 @@ class UnusedSymbolInspection : AbstractKotlinInspection() {
     }
 
     private fun hasNonTrivialUsages(declaration: KtNamedDeclaration, descriptor: DeclarationDescriptor? = null): Boolean {
-        val psiSearchHelper = PsiSearchHelper.SERVICE.getInstance(declaration.project)
+        val project = declaration.project
+        val psiSearchHelper = PsiSearchHelper.SERVICE.getInstance(project)
 
         val useScope = declaration.useScope
         val restrictedScope = if (useScope is GlobalSearchScope) {
@@ -206,14 +209,18 @@ class UnusedSymbolInspection : AbstractKotlinInspection() {
                 }
             }
 
-            if (zeroOccurrences) {
+            if (zeroOccurrences && !declaration.hasActualModifier()) {
                 if (declaration is KtObjectDeclaration && declaration.isCompanion()) {
                     // go on: companion object can be used only in containing class
                 } else {
                     return false
                 }
             }
-            KotlinSourceFilterScope.projectSources(useScope, declaration.project)
+            if (declaration.hasActualModifier()) {
+                KotlinSourceFilterScope.projectSources(project.projectScope(), project)
+            } else {
+                KotlinSourceFilterScope.projectSources(useScope, project)
+            }
         } else useScope
 
         return (declaration is KtObjectDeclaration && declaration.isCompanion() &&
@@ -221,7 +228,6 @@ class UnusedSymbolInspection : AbstractKotlinInspection() {
                 hasReferences(declaration, descriptor, restrictedScope) ||
                 hasOverrides(declaration, restrictedScope) ||
                 hasFakeOverrides(declaration, restrictedScope) ||
-                isPlatformImplementation(declaration) ||
                 hasPlatformImplementations(declaration, descriptor)
     }
 
@@ -267,7 +273,8 @@ class UnusedSymbolInspection : AbstractKotlinInspection() {
             return false
         }
 
-        val referenceUsed: Boolean by lazy { !ReferencesSearch.search(declaration, useScope).forEach(::checkReference) }
+        val searchParameters = KotlinReferencesSearchParameters(declaration, useScope)
+        val referenceUsed: Boolean by lazy { !ReferencesSearch.search(searchParameters).forEach(::checkReference) }
 
         if (descriptor is FunctionDescriptor &&
             DescriptorUtils.getAnnotationByFqName(descriptor.annotations, JvmFileClassUtil.JVM_NAME) != null
@@ -278,9 +285,11 @@ class UnusedSymbolInspection : AbstractKotlinInspection() {
         if (declaration is KtCallableDeclaration && !declaration.hasModifier(KtTokens.INTERNAL_KEYWORD)) {
             val lightMethods = declaration.toLightMethods()
             if (lightMethods.isNotEmpty()) {
-                return lightMethods.any { method ->
+                val lightMethodsUsed = lightMethods.any { method ->
                     !MethodReferencesSearch.search(method).forEach(::checkReference)
                 }
+                if (lightMethodsUsed) return true
+                if (!declaration.hasActualModifier()) return false
             }
         }
 
@@ -319,9 +328,6 @@ class UnusedSymbolInspection : AbstractKotlinInspection() {
         }
     }
 
-    private fun isPlatformImplementation(declaration: KtNamedDeclaration) =
-        declaration.hasActualModifier()
-
     private fun hasPlatformImplementations(declaration: KtNamedDeclaration, descriptor: DeclarationDescriptor?): Boolean {
         if (!declaration.hasExpectModifier()) return false
 

idea/testData/inspections/unusedSymbol/class/headerImpl.kt

@@ -1,9 +1,9 @@
 // No "unused symbol" should be reported here
-
 expect class My
 
+// But this should be reported
 actual class My
 
-// But this should be reported
+// And this too
 expect val bar: String
 

idea/testData/inspections/unusedSymbol/class/inspectionData/expected.xml

@@ -63,6 +63,14 @@
     <problem_class severity="WARNING" attribute_key="NOT_USED_ELEMENT_ATTRIBUTES">Unused symbol</problem_class>
     <description>Class 'Some' is never used</description>
   </problem>
+  <problem>
+    <file>headerImpl.kt</file>
+    <line>5</line>
+    <module>light_idea_test_case</module>
+    <entry_point TYPE="file" FQNAME="temp:///src/headerImpl.kt" />
+    <problem_class severity="WARNING" attribute_key="NOT_USED_ELEMENT_ATTRIBUTES">Unused symbol</problem_class>
+    <description>Class 'My' is never used</description>
+  </problem>
   <problem>
     <file>headerImpl.kt</file>
     <line>8</line>

idea/testData/multiModuleQuickFix/safeDeleteForbiddenFromActual/common/common.kt

@@ -0,0 +1,7 @@
+expect class My constructor() {
+    fun foo()
+}
+
+fun test() {
+    My().foo()
+}

idea/testData/multiModuleQuickFix/safeDeleteForbiddenFromActual/common/common.kt.after

@@ -0,0 +1,7 @@
+expect class My constructor() {
+    fun foo()
+}
+
+fun test() {
+    My().foo()
+}

idea/testData/multiModuleQuickFix/safeDeleteForbiddenFromActual/jvm/jvm.kt

@@ -0,0 +1,8 @@
+// "Safe delete 'foo'" "false"
+// TOOL: org.jetbrains.kotlin.idea.inspections.UnusedSymbolInspection
+// ACTION: Convert member to extension
+// ACTION: Move to companion object
+
+actual class My {
+    actual fun <caret>foo() {}
+}

idea/testData/multiModuleQuickFix/safeDeleteForbiddenFromActual/jvm/jvm.kt.after

@@ -0,0 +1,8 @@
+// "Safe delete 'foo'" "false"
+// TOOL: org.jetbrains.kotlin.idea.inspections.UnusedSymbolInspection
+// ACTION: Convert member to extension
+// ACTION: Move to companion object
+
+actual class My {
+    actual fun foo() {}
+}

idea/testData/multiModuleQuickFix/safeDeleteFromActual/common/common.kt

@@ -0,0 +1,4 @@
+expect class My constructor() {
+    // TODO: also should be deleted (KT-15666)
+    fun foo()
+}

idea/testData/multiModuleQuickFix/safeDeleteFromActual/common/common.kt.after

@@ -0,0 +1,4 @@
+expect class My constructor() {
+    // TODO: also should be deleted (KT-15666)
+    fun foo()
+}

idea/testData/multiModuleQuickFix/safeDeleteFromActual/jvm/jvm.kt

@@ -0,0 +1,6 @@
+// "Safe delete 'foo'" "true"
+// TOOL: org.jetbrains.kotlin.idea.inspections.UnusedSymbolInspection
+
+actual class My {
+    actual fun <caret>foo() {}
+}

idea/testData/multiModuleQuickFix/safeDeleteFromActual/jvm/jvm.kt.after

@@ -0,0 +1,5 @@
+// "Safe delete 'foo'" "true"
+// TOOL: org.jetbrains.kotlin.idea.inspections.UnusedSymbolInspection
+
+actual class My {
+}

idea/tests/org/jetbrains/kotlin/idea/quickfix/AbstractQuickFixMultiModuleTest.kt

@@ -23,7 +23,7 @@ import org.jetbrains.kotlin.test.InTextDirectivesUtils
 import org.jetbrains.kotlin.test.KotlinTestUtils
 import java.io.File
 
-abstract class AbstractQuickFixMultiModuleTest : AbstractMultiModuleTest() {
+abstract class AbstractQuickFixMultiModuleTest : AbstractMultiModuleTest(), QuickFixTest {
 
     override fun getTestDataPath() = PluginTestCaseBase.getTestDataPathBase() + "/multiModuleQuickFix/"
 
@@ -34,10 +34,12 @@ abstract class AbstractQuickFixMultiModuleTest : AbstractMultiModuleTest() {
 
     private fun doQuickFixTest() {
         val actionFile = project.findFileWithCaret()
-        configureByExistingFile(actionFile.virtualFile!!)
+        val virtualFile = actionFile.virtualFile!!
-
+        configureByExistingFile(virtualFile)
         val actionFileText = actionFile.text
         val actionFileName = actionFile.name
+        val inspections = parseInspectionsToEnable(virtualFile.path, actionFileText).toTypedArray()
+        enableInspectionTools(*inspections)
 
         CommandProcessor.getInstance().executeCommand(project, {
             try {

idea/tests/org/jetbrains/kotlin/idea/quickfix/AbstractQuickFixTest.kt

@@ -18,19 +18,18 @@ package org.jetbrains.kotlin.idea.quickfix
 
 import com.intellij.codeInsight.daemon.quickFix.ActionHint
 import com.intellij.codeInsight.intention.IntentionAction
-import com.intellij.codeInspection.InspectionProfileEntry
-import com.intellij.codeInspection.LocalInspectionTool
 import com.intellij.codeInspection.SuppressableProblemGroup
 import com.intellij.openapi.command.CommandProcessor
 import com.intellij.openapi.util.io.FileUtil
 import com.intellij.openapi.util.text.StringUtil
 import com.intellij.openapi.vfs.CharsetToolkit
 import com.intellij.rt.execution.junit.FileComparisonFailure
-import com.intellij.testFramework.*
+import com.intellij.testFramework.LightPlatformTestCase
+import com.intellij.testFramework.LightProjectDescriptor
+import com.intellij.testFramework.UsefulTestCase
 import com.intellij.util.ui.UIUtil
 import junit.framework.TestCase
 import org.jetbrains.kotlin.idea.facet.KotlinFacet
-import org.jetbrains.kotlin.idea.quickfix.utils.findInspectionFile
 import org.jetbrains.kotlin.idea.test.*
 import org.jetbrains.kotlin.psi.KtFile
 import org.jetbrains.kotlin.test.InTextDirectivesUtils
@@ -38,13 +37,13 @@ import org.junit.Assert
 import java.io.File
 import java.io.IOException
 
-abstract class AbstractQuickFixTest : KotlinLightCodeInsightFixtureTestCase() {
+abstract class AbstractQuickFixTest : KotlinLightCodeInsightFixtureTestCase(), QuickFixTest {
     @Throws(Exception::class)
     protected fun doTest(beforeFileName: String) {
         val beforeFileText = FileUtil.loadFile(File(beforeFileName))
         configureCompilerOptions(beforeFileText, project, module)
 
-        val inspections = parceInspectionsToEnable(beforeFileName, beforeFileText).toTypedArray()
+        val inspections = parseInspectionsToEnable(beforeFileName, beforeFileText).toTypedArray()
 
         try {
             myFixture.enableInspections(*inspections)
@@ -171,31 +170,6 @@ abstract class AbstractQuickFixTest : KotlinLightCodeInsightFixtureTestCase() {
         }
     }
 
-    private fun parceInspectionsToEnable(beforeFileName: String, beforeFileText: String): List<InspectionProfileEntry> {
-        val toolsStrings = InTextDirectivesUtils.findListWithPrefixes(beforeFileText, "TOOL:")
-        if (toolsStrings.isNotEmpty()) {
-            val inspections =  toolsStrings.map { toolFqName ->
-                try {
-                    val aClass = Class.forName(toolFqName)
-                    return@map aClass.newInstance() as LocalInspectionTool
-                }
-                catch (e: Exception) {
-                    throw IllegalArgumentException("Failed to create inspection for key '$toolFqName'", e)
-                }
-            }
-            return inspections
-        }
-
-        val inspectionFile = findInspectionFile(File(beforeFileName).parentFile)
-        if (inspectionFile != null) {
-            val className = FileUtil.loadFile(inspectionFile).trim { it <= ' ' }
-            val inspectionClass = Class.forName(className) as Class<InspectionProfileEntry>
-            return InspectionTestUtil.instantiateTools(listOf<Class<out InspectionProfileEntry>>(inspectionClass))
-        }
-
-        return emptyList()
-    }
-
     @Throws(ClassNotFoundException::class)
     private fun checkForUnexpectedActions() {
         val text = myFixture.editor.document.text

idea/tests/org/jetbrains/kotlin/idea/quickfix/AbstractQuickFixTest.kt.172

@@ -18,8 +18,6 @@ package org.jetbrains.kotlin.idea.quickfix
 
 import com.intellij.codeInsight.daemon.quickFix.ActionHint
 import com.intellij.codeInsight.intention.IntentionAction
-import com.intellij.codeInspection.InspectionProfileEntry
-import com.intellij.codeInspection.LocalInspectionTool
 import com.intellij.codeInspection.SuppressableProblemGroup
 import com.intellij.openapi.command.CommandProcessor
 import com.intellij.openapi.util.io.FileUtil
@@ -30,7 +28,6 @@ import com.intellij.testFramework.*
 import com.intellij.util.ui.UIUtil
 import junit.framework.TestCase
 import org.jetbrains.kotlin.idea.facet.KotlinFacet
-import org.jetbrains.kotlin.idea.quickfix.utils.findInspectionFile
 import org.jetbrains.kotlin.idea.test.*
 import org.jetbrains.kotlin.psi.KtFile
 import org.jetbrains.kotlin.test.InTextDirectivesUtils
@@ -38,13 +35,13 @@ import org.junit.Assert
 import java.io.File
 import java.io.IOException
 
-abstract class AbstractQuickFixTest : KotlinLightCodeInsightFixtureTestCase() {
+abstract class AbstractQuickFixTest : KotlinLightCodeInsightFixtureTestCase(), QuickFixTest {
     @Throws(Exception::class)
     protected fun doTest(beforeFileName: String) {
         val beforeFileText = FileUtil.loadFile(File(beforeFileName))
         configureCompilerOptions(beforeFileText, project, module)
 
-        val inspections = parceInspectionsToEnable(beforeFileName, beforeFileText).toTypedArray()
+        val inspections = parseInspectionsToEnable(beforeFileName, beforeFileText).toTypedArray()
 
         try {
             myFixture.enableInspections(*inspections)
@@ -156,31 +153,6 @@ abstract class AbstractQuickFixTest : KotlinLightCodeInsightFixtureTestCase() {
         }
     }
 
-    private fun parceInspectionsToEnable(beforeFileName: String, beforeFileText: String): List<InspectionProfileEntry> {
-        val toolsStrings = InTextDirectivesUtils.findListWithPrefixes(beforeFileText, "TOOL:")
-        if (toolsStrings.isNotEmpty()) {
-            val inspections =  toolsStrings.map { toolFqName ->
-                try {
-                    val aClass = Class.forName(toolFqName)
-                    return@map aClass.newInstance() as LocalInspectionTool
-                }
-                catch (e: Exception) {
-                    throw IllegalArgumentException("Failed to create inspection for key '$toolFqName'", e)
-                }
-            }
-            return inspections
-        }
-
-        val inspectionFile = findInspectionFile(File(beforeFileName).parentFile)
-        if (inspectionFile != null) {
-            val className = FileUtil.loadFile(inspectionFile).trim { it <= ' ' }
-            val inspectionClass = Class.forName(className) as Class<InspectionProfileEntry>
-            return InspectionTestUtil.instantiateTools(listOf<Class<out InspectionProfileEntry>>(inspectionClass))
-        }
-
-        return emptyList()
-    }
-
     @Throws(ClassNotFoundException::class)
     private fun checkForUnexpectedActions() {
         val text = myFixture.editor.document.text

idea/tests/org/jetbrains/kotlin/idea/quickfix/QuickFixMultiModuleTestGenerated.java

@@ -334,6 +334,16 @@ public class QuickFixMultiModuleTestGenerated extends AbstractQuickFixMultiModul
         runTest("idea/testData/multiModuleQuickFix/property/");
     }
 
+    @TestMetadata("safeDeleteForbiddenFromActual")
+    public void testSafeDeleteForbiddenFromActual() throws Exception {
+        runTest("idea/testData/multiModuleQuickFix/safeDeleteForbiddenFromActual/");
+    }
+
+    @TestMetadata("safeDeleteFromActual")
+    public void testSafeDeleteFromActual() throws Exception {
+        runTest("idea/testData/multiModuleQuickFix/safeDeleteFromActual/");
+    }
+
     @TestMetadata("sealed")
     public void testSealed() throws Exception {
         runTest("idea/testData/multiModuleQuickFix/sealed/");

idea/tests/org/jetbrains/kotlin/idea/quickfix/QuickFixTest.kt

@@ -0,0 +1,39 @@
+/*
+ * Copyright 2010-2018 JetBrains s.r.o. 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.idea.quickfix
+
+import com.intellij.codeInspection.InspectionProfileEntry
+import com.intellij.codeInspection.LocalInspectionTool
+import com.intellij.openapi.util.io.FileUtil
+import com.intellij.testFramework.InspectionTestUtil
+import org.jetbrains.kotlin.idea.quickfix.utils.findInspectionFile
+import org.jetbrains.kotlin.test.InTextDirectivesUtils
+import java.io.File
+
+interface QuickFixTest {
+    fun parseInspectionsToEnable(beforeFileName: String, beforeFileText: String): List<InspectionProfileEntry> {
+        val toolsStrings = InTextDirectivesUtils.findListWithPrefixes(beforeFileText, "TOOL:")
+        if (toolsStrings.isNotEmpty()) {
+            return toolsStrings.map { toolFqName ->
+                try {
+                    val aClass = Class.forName(toolFqName)
+                    return@map aClass.newInstance() as LocalInspectionTool
+                } catch (e: Exception) {
+                    throw IllegalArgumentException("Failed to create inspection for key '$toolFqName'", e)
+                }
+            }
+        }
+
+        val inspectionFile = findInspectionFile(File(beforeFileName).parentFile)
+        if (inspectionFile != null) {
+            val className = FileUtil.loadFile(inspectionFile).trim { it <= ' ' }
+            val inspectionClass = Class.forName(className) as Class<InspectionProfileEntry>
+            return InspectionTestUtil.instantiateTools(listOf<Class<out InspectionProfileEntry>>(inspectionClass))
+        }
+
+        return emptyList()
+    }
+}