Class used in text is not unused.

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

@@ -31,6 +31,9 @@ import org.jetbrains.kotlin.idea.JetBundle
 import com.intellij.codeInspection.ProblemHighlightType
 import com.intellij.codeInspection.deadCode.UnusedDeclarationInspection
 import org.jetbrains.kotlin.asJava.LightClassUtil
+import org.jetbrains.kotlin.idea.findUsages.handlers.KotlinFindClassUsagesHandler
+import com.intellij.psi.search.GlobalSearchScope
+import org.jetbrains.kotlin.idea.findUsages.KotlinFindUsagesHandlerFactory
 
 public class UnusedSymbolInspection : AbstractKotlinInspection() {
     private val javaInspection = UnusedDeclarationInspection()
@@ -45,8 +48,10 @@ public class UnusedSymbolInspection : AbstractKotlinInspection() {
                 val lightClass = LightClassUtil.getPsiClass(klass)
                 if (lightClass != null && javaInspection.isEntryPoint(lightClass)) return
 
+                val classUseScope = klass.getUseScope()
+
                 val usagesSearchHelper = KotlinClassFindUsagesOptions(holder.getProject()).toClassHelper()
-                val request = usagesSearchHelper.newRequest(UsagesSearchTarget(klass, klass.getUseScope()))
+                val request = usagesSearchHelper.newRequest(UsagesSearchTarget(klass, classUseScope))
                 val query = UsagesSearch.search(request)
 
                 var foundNonTrivialUsage = false
@@ -61,6 +66,16 @@ public class UnusedSymbolInspection : AbstractKotlinInspection() {
                     }
                 })
 
+                // Finding text usages
+                if (classUseScope is GlobalSearchScope) {
+                    val findClassUsagesHandler = KotlinFindClassUsagesHandler(klass, KotlinFindUsagesHandlerFactory(klass.getProject()))
+                    findClassUsagesHandler.processUsagesInText(
+                            klass,
+                            { foundNonTrivialUsage = true; false },
+                            classUseScope
+                    )
+                }
+
                 if (!foundNonTrivialUsage) {
                     holder.registerProblem(
                             klass.getNameIdentifier(),

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

@@ -23,4 +23,12 @@
     <problem_class severity="WARNING" attribute_key="NOT_USED_ELEMENT_ATTRIBUTES">Unused Symbol</problem_class>
     <description>Class 'Local' is never used</description>
   </problem>
+  <problem>
+    <file>usedInTextByShortName.kt</file>
+    <line>3</line>
+    <module>light_idea_test_case</module>
+    <entry_point TYPE="file" FQNAME="temp:///src/usedInTextByShortName.kt" />
+    <problem_class severity="WARNING" attribute_key="NOT_USED_ELEMENT_ATTRIBUTES">Unused Symbol</problem_class>
+    <description>Class 'UsedInTextByShortName' is never used</description>
+  </problem>
 </problems>

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

@@ -0,0 +1,3 @@
+package foo
+
+class UsedInTextOnly

idea/testData/inspections/unusedSymbol/class/usedInText.txt

@@ -0,0 +1 @@
+foo.UsedInTextOnly

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

@@ -0,0 +1,3 @@
+package foo
+
+class UsedInTextByShortName

idea/testData/inspections/unusedSymbol/class/usedInTextByShortName.txt

@@ -0,0 +1 @@
+UsedInTextByShortName

idea/tests/org/jetbrains/kotlin/idea/codeInsight/AbstractJetInspectionTest.kt

@@ -53,11 +53,15 @@ public abstract class AbstractJetInspectionTest: LightCodeInsightFixtureTestCase
             setTestDataPath("${JetTestUtils.getHomeDirectory()}/$srcDir")
 
             val psiFiles = srcDir
-                    .listFiles { it.getName().endsWith(".kt") }!!
+                    .listFiles { it.getName().endsWith(".kt") || it.getName().endsWith(".txt") }!!
                     .map {
                         file ->
                         val text = FileUtil.loadFile(file, true)
-                        val fileText = if (text.startsWith("package")) text else "package ${file.getName().trimTrailing(".kt")};$text"
+                        val fileText =
+                                if (text.startsWith("package") || !file.getName().endsWith(".kt"))
+                                    text
+                                else
+                                    "package ${file.getName().trimTrailing(".kt")};$text"
                         configureByText(file.getName(), fileText)!!
                     }