Introduce inspection to detect vals might be marked as const

So #KT-20644 Fixed
2017-12-07 17:36:13 +03:00
parent 4ec20ad595
commit 70b7e5eb68
20 changed files with 222 additions and 0 deletions
@@ -0,0 +1,6 @@
+<html>
+<body>
+This inspection reports object and top-level <code>val</code> that might be declared as <code>const</code>
+for better performance and Java interoperability.
+</body>
+</html>
@@ -2712,6 +2712,15 @@
                     cleanupTool="true"
    />

+    <localInspection implementationClass="org.jetbrains.kotlin.idea.inspections.MayBeConstantInspection"
+                     displayName="Might be 'const'"
+                     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 +1,69 @@
+/*
+ * Copyright 2010-2017 JetBrains s.r.o.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.jetbrains.kotlin.idea.inspections
+
+import com.intellij.codeInspection.IntentionWrapper
+import com.intellij.codeInspection.ProblemHighlightType
+import com.intellij.codeInspection.ProblemsHolder
+import com.intellij.psi.PsiElementVisitor
+import org.jetbrains.kotlin.descriptors.VariableDescriptor
+import org.jetbrains.kotlin.idea.caches.resolve.analyze
+import org.jetbrains.kotlin.idea.quickfix.AddConstModifierFix
+import org.jetbrains.kotlin.lexer.KtTokens
+import org.jetbrains.kotlin.psi.KtClass
+import org.jetbrains.kotlin.psi.KtProperty
+import org.jetbrains.kotlin.psi.KtVisitorVoid
+import org.jetbrains.kotlin.psi.psiUtil.containingClassOrObject
+import org.jetbrains.kotlin.resolve.BindingContext
+import org.jetbrains.kotlin.resolve.constants.evaluate.ConstantExpressionEvaluator
+import org.jetbrains.kotlin.resolve.constants.evaluate.isStandaloneOnlyConstant
+import org.jetbrains.kotlin.resolve.jvm.annotations.hasJvmFieldAnnotation
+import org.jetbrains.kotlin.resolve.lazy.BodyResolveMode
+
+class MayBeConstantInspection : AbstractKotlinInspection() {
+    override fun buildVisitor(holder: ProblemsHolder, isOnTheFly: Boolean): PsiElementVisitor {
+        return object : KtVisitorVoid() {
+            override fun visitProperty(property: KtProperty) {
+                super.visitProperty(property)
+
+                if (property.isLocal || property.isVar) return
+                val initializer = property.initializer ?: return
+                if (property.hasModifier(KtTokens.CONST_KEYWORD)) return
+                // Top-level or object only
+                if (property.containingClassOrObject is KtClass) return
+
+                // For some reason constant evaluation does not work for property.analyze()
+                val context = initializer.analyze(BodyResolveMode.PARTIAL)
+                val propertyDescriptor = context[BindingContext.DECLARATION_TO_DESCRIPTOR, property] as? VariableDescriptor ?: return
+                val withJvmField = propertyDescriptor.hasJvmFieldAnnotation()
+                if (property.annotationEntries.isNotEmpty() && !withJvmField) return
+
+                val initializerValue = ConstantExpressionEvaluator.getConstant(
+                        initializer, context
+                )?.toConstantValue(propertyDescriptor.type) ?: return
+                if (initializerValue.isStandaloneOnlyConstant()) return
+
+                holder.registerProblem(
+                        property.nameIdentifier ?: property,
+                        if (withJvmField) "'const' might be used instead of '@JvmField'" else "Might be 'const'",
+                        ProblemHighlightType.GENERIC_ERROR_OR_WARNING,
+                        IntentionWrapper(AddConstModifierFix(property), property.containingFile)
+                )
+            }
+        }
+    }
+}
@@ -0,0 +1 @@
+org.jetbrains.kotlin.idea.inspections.MayBeConstantInspection
@@ -0,0 +1,9 @@
+// WITH_RUNTIME
+
+const val y = 0
+
+class Your {
+    companion object {
+        @JvmField val <caret>z = y + 3
+    }
+}
@@ -0,0 +1,9 @@
+// WITH_RUNTIME
+
+const val y = 0
+
+class Your {
+    companion object {
+        const val z = y + 3
+    }
+}
@@ -0,0 +1,5 @@
+class Your {
+    companion object {
+        val <caret>IMPORTANT = 2 * 2
+    }
+}
@@ -0,0 +1,5 @@
+class Your {
+    companion object {
+        const val IMPORTANT = 2 * 2
+    }
+}
@@ -0,0 +1,4 @@
+// PROBLEM: none
+// WITH_RUNTIME
+
+const val <caret>x = 13
@@ -0,0 +1,3 @@
+// PROBLEM: none
+
+val <caret>withGetter get() = 42
@@ -0,0 +1,6 @@
+// PROBLEM: none
+// WITH_RUNTIME
+
+class My {
+    @JvmField val <caret>x = 13
+}
@@ -0,0 +1,6 @@
+// PROBLEM: none
+// WITH_RUNTIME
+
+annotation class A
+
+@A val <caret>x = 55
@@ -0,0 +1,5 @@
+// WITH_RUNTIME
+
+object O {
+    @JvmField val <caret>s = "He" + "llo"
+}
@@ -0,0 +1,5 @@
+// WITH_RUNTIME
+
+object O {
+    const val s = "He" + "llo"
+}
@@ -0,0 +1,3 @@
+// WITH_RUNTIME
+
+@JvmField val <caret>x = 1
@@ -0,0 +1,3 @@
+// WITH_RUNTIME
+
+const val x = 1
@@ -0,0 +1 @@
+val <caret>x = 1
@@ -0,0 +1 @@
+const val x = 1
@@ -0,0 +1,3 @@
+// PROBLEM: none
+
+var <caret>n = 1
@@ -1281,6 +1281,75 @@ public class LocalInspectionTestGenerated extends AbstractLocalInspectionTest {
        }
    }

+    @TestMetadata("idea/testData/inspectionsLocal/mayBeConstant")
+    @TestDataPath("$PROJECT_ROOT")
+    @RunWith(JUnit3RunnerWithInners.class)
+    public static class MayBeConstant extends AbstractLocalInspectionTest {
+        public void testAllFilesPresentInMayBeConstant() throws Exception {
+            KotlinTestUtils.assertAllTestsPresentByMetadata(this.getClass(), new File("idea/testData/inspectionsLocal/mayBeConstant"), Pattern.compile("^([\\w\\-_]+)\\.kt$"), TargetBackend.ANY, true);
+        }
+
+        @TestMetadata("cascadeConst.kt")
+        public void testCascadeConst() throws Exception {
+            String fileName = KotlinTestUtils.navigationMetadata("idea/testData/inspectionsLocal/mayBeConstant/cascadeConst.kt");
+            doTest(fileName);
+        }
+
+        @TestMetadata("companion.kt")
+        public void testCompanion() throws Exception {
+            String fileName = KotlinTestUtils.navigationMetadata("idea/testData/inspectionsLocal/mayBeConstant/companion.kt");
+            doTest(fileName);
+        }
+
+        @TestMetadata("const.kt")
+        public void testConst() throws Exception {
+            String fileName = KotlinTestUtils.navigationMetadata("idea/testData/inspectionsLocal/mayBeConstant/const.kt");
+            doTest(fileName);
+        }
+
+        @TestMetadata("getter.kt")
+        public void testGetter() throws Exception {
+            String fileName = KotlinTestUtils.navigationMetadata("idea/testData/inspectionsLocal/mayBeConstant/getter.kt");
+            doTest(fileName);
+        }
+
+        @TestMetadata("inClass.kt")
+        public void testInClass() throws Exception {
+            String fileName = KotlinTestUtils.navigationMetadata("idea/testData/inspectionsLocal/mayBeConstant/inClass.kt");
+            doTest(fileName);
+        }
+
+        @TestMetadata("nonJvmFieldAnnotated.kt")
+        public void testNonJvmFieldAnnotated() throws Exception {
+            String fileName = KotlinTestUtils.navigationMetadata("idea/testData/inspectionsLocal/mayBeConstant/nonJvmFieldAnnotated.kt");
+            doTest(fileName);
+        }
+
+        @TestMetadata("object.kt")
+        public void testObject() throws Exception {
+            String fileName = KotlinTestUtils.navigationMetadata("idea/testData/inspectionsLocal/mayBeConstant/object.kt");
+            doTest(fileName);
+        }
+
+        @TestMetadata("simple.kt")
+        public void testSimple() throws Exception {
+            String fileName = KotlinTestUtils.navigationMetadata("idea/testData/inspectionsLocal/mayBeConstant/simple.kt");
+            doTest(fileName);
+        }
+
+        @TestMetadata("simplest.kt")
+        public void testSimplest() throws Exception {
+            String fileName = KotlinTestUtils.navigationMetadata("idea/testData/inspectionsLocal/mayBeConstant/simplest.kt");
+            doTest(fileName);
+        }
+
+        @TestMetadata("var.kt")
+        public void testVar() throws Exception {
+            String fileName = KotlinTestUtils.navigationMetadata("idea/testData/inspectionsLocal/mayBeConstant/var.kt");
+            doTest(fileName);
+        }
+    }
+
    @TestMetadata("idea/testData/inspectionsLocal/memberVisibilityCanBePrivate")
    @TestDataPath("$PROJECT_ROOT")
    @RunWith(JUnit3RunnerWithInners.class)
				`@@ -0,0 +1 @@`
				`org.jetbrains.kotlin.idea.inspections.MayBeConstantInspection`