Introduce inspection for unused main parameter #KT-26999 Fixed

2018-10-30 18:39:20 +03:00
parent ad44118605
commit 318d6e7111
11 changed files with 113 additions and 2 deletions
@@ -671,8 +671,18 @@ class ControlFlowInformationProvider private constructor(
                val mainFunctionDetector = MainFunctionDetector(trace.bindingContext, languageVersionSettings)
                val isMain = owner is KtNamedFunction && mainFunctionDetector.isMain(owner)
                val functionName = functionDescriptor.name
-                if (isMain && !languageVersionSettings.supportsFeature(LanguageFeature.WarningOnMainUnusedParameter)
-                    || functionDescriptor.isOverridableOrOverrides
+                if (isMain) {
+                    when {
+                        !languageVersionSettings.supportsFeature(LanguageFeature.ExtendedMainConvention) -> {
+                            return
+                        }
+                        !languageVersionSettings.supportsFeature(LanguageFeature.WarningOnMainUnusedParameter) -> {
+                            trace.record(UNUSED_MAIN_PARAMETER, element)
+                            return
+                        }
+                    }
+                }
+                if (functionDescriptor.isOverridableOrOverrides
                    || owner.hasModifier(KtTokens.OVERRIDE_KEYWORD)
                    || OperatorNameConventions.GET_VALUE == functionName
                    || OperatorNameConventions.SET_VALUE == functionName
@@ -103,6 +103,7 @@ public interface BindingContext {
    WritableSlice<KtExpression, DataFlowInfo> DATAFLOW_INFO_AFTER_CONDITION = Slices.createSimpleSlice();
    WritableSlice<VariableDescriptor, DataFlowValue> BOUND_INITIALIZER_VALUE = Slices.createSimpleSlice();
    WritableSlice<KtExpression, LeakingThisDescriptor> LEAKING_THIS = Slices.createSimpleSlice();
+    WritableSlice<KtParameter, Boolean> UNUSED_MAIN_PARAMETER = Slices.createSimpleSlice();

    /**
     * A qualifier corresponds to a receiver expression (if any). For 'A.B' qualifier is recorded for 'A'.
@@ -0,0 +1,5 @@
+<html>
+<body>
+This inspection reports an unused main function parameter which is not necessary since Kotlin 1.3.
+</body>
+</html>
@@ -3075,6 +3075,15 @@
                     language="kotlin"
    />

+    <localInspection implementationClass="org.jetbrains.kotlin.idea.inspections.UnusedMainParameterInspection"
+                     displayName="Main parameter is not necessary"
+                     groupPath="Kotlin"
+                     groupName="Style issues"
+                     enabledByDefault="true"
+                     level="WEAK WARNING"
+                     language="kotlin"
+    />
+
    <referenceImporter implementation="org.jetbrains.kotlin.idea.quickfix.KotlinReferenceImporter"/>

    <fileType.fileViewProviderFactory filetype="KJSM" implementationClass="com.intellij.psi.ClassFileViewProviderFactory"/>
@@ -0,0 +1,35 @@
+/*
+ * 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.inspections
+
+import com.intellij.codeInspection.IntentionWrapper
+import com.intellij.codeInspection.LocalInspectionToolSession
+import com.intellij.codeInspection.ProblemHighlightType
+import com.intellij.codeInspection.ProblemsHolder
+import org.jetbrains.kotlin.idea.caches.resolve.analyzeWithContent
+import org.jetbrains.kotlin.idea.quickfix.RemoveUnusedFunctionParameterFix
+import org.jetbrains.kotlin.psi.KtNamedFunction
+import org.jetbrains.kotlin.psi.KtParameter
+import org.jetbrains.kotlin.psi.parameterVisitor
+import org.jetbrains.kotlin.resolve.BindingContext.UNUSED_MAIN_PARAMETER
+
+class UnusedMainParameterInspection : AbstractKotlinInspection() {
+
+    override fun buildVisitor(holder: ProblemsHolder, isOnTheFly: Boolean, session: LocalInspectionToolSession) =
+        parameterVisitor(fun(parameter: KtParameter) {
+            val function = parameter.ownerFunction as? KtNamedFunction ?: return
+            if (function.name != "main") return
+            val context = function.analyzeWithContent()
+            if (context[UNUSED_MAIN_PARAMETER, parameter] == true) {
+                holder.registerProblem(
+                    parameter,
+                    "Since Kotlin 1.3 main parameter is not necessary",
+                    ProblemHighlightType.LIKE_UNUSED_SYMBOL,
+                    IntentionWrapper(RemoveUnusedFunctionParameterFix(parameter), parameter.containingFile)
+                )
+            }
+        })
+}
@@ -0,0 +1 @@
+org.jetbrains.kotlin.idea.inspections.UnusedMainParameterInspection
@@ -0,0 +1,6 @@
+// PROBLEM: none
+// LANGUAGE_VERSION: 1.4
+
+fun main(<caret>args: Array<String>) {
+
+}
@@ -0,0 +1,6 @@
+// PROBLEM: none
+// LANGUAGE_VERSION: 1.2
+
+fun main(<caret>args: Array<String>) {
+
+}
@@ -0,0 +1,5 @@
+// LANGUAGE_VERSION: 1.3
+
+fun main(<caret>args: Array<String>) {
+
+}
@@ -0,0 +1,5 @@
+// LANGUAGE_VERSION: 1.3
+
+fun main() {
+
+}
@@ -6468,6 +6468,34 @@ public class LocalInspectionTestGenerated extends AbstractLocalInspectionTest {
        }
    }

+    @TestMetadata("idea/testData/inspectionsLocal/unusedMainParameter")
+    @TestDataPath("$PROJECT_ROOT")
+    @RunWith(JUnit3RunnerWithInners.class)
+    public static class UnusedMainParameter extends AbstractLocalInspectionTest {
+        private void runTest(String testDataFilePath) throws Exception {
+            KotlinTestUtils.runTest(this::doTest, TargetBackend.ANY, testDataFilePath);
+        }
+
+        public void testAllFilesPresentInUnusedMainParameter() throws Exception {
+            KotlinTestUtils.assertAllTestsPresentByMetadata(this.getClass(), new File("idea/testData/inspectionsLocal/unusedMainParameter"), Pattern.compile("^([\\w\\-_]+)\\.(kt|kts)$"), TargetBackend.ANY, true);
+        }
+
+        @TestMetadata("future.kt")
+        public void testFuture() throws Exception {
+            runTest("idea/testData/inspectionsLocal/unusedMainParameter/future.kt");
+        }
+
+        @TestMetadata("legacy.kt")
+        public void testLegacy() throws Exception {
+            runTest("idea/testData/inspectionsLocal/unusedMainParameter/legacy.kt");
+        }
+
+        @TestMetadata("simple.kt")
+        public void testSimple() throws Exception {
+            runTest("idea/testData/inspectionsLocal/unusedMainParameter/simple.kt");
+        }
+    }
+
    @TestMetadata("idea/testData/inspectionsLocal/unusedReceiverParameter")
    @TestDataPath("$PROJECT_ROOT")
    @RunWith(JUnit3RunnerWithInners.class)
				`@@ -0,0 +1 @@`
				`org.jetbrains.kotlin.idea.inspections.UnusedMainParameterInspection`