Illegal Dalvik identifier inspection

idea/kotlin-android-plugin/src/org/jetbrains/kotlin/android/androidUtil.kt

@@ -0,0 +1,25 @@
+/*
+ * Copyright 2010-2016 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.android
+
+import com.intellij.psi.PsiElement
+import org.jetbrains.android.facet.AndroidFacet
+
+fun PsiElement.getAndroidFacetForFile(): AndroidFacet? {
+    val file = containingFile ?: return null
+    return AndroidFacet.getInstance(file)
+}

idea/kotlin-android-plugin/src/org/jetbrains/kotlin/android/inspection/IllegalIdentifierInspection.kt

@@ -0,0 +1,89 @@
+/*
+ * Copyright 2010-2016 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.android.inspection
+
+import com.intellij.codeInsight.FileModificationService
+import com.intellij.codeInspection.*
+import com.intellij.ide.DataManager
+import com.intellij.openapi.application.ApplicationManager
+import com.intellij.openapi.fileEditor.FileEditorManager
+import com.intellij.openapi.project.Project
+import com.intellij.psi.PsiElement
+import com.intellij.psi.PsiElementVisitor
+import com.intellij.refactoring.rename.RenameHandlerRegistry
+import org.jetbrains.kotlin.android.getAndroidFacetForFile
+import org.jetbrains.kotlin.idea.inspections.AbstractKotlinInspection
+import org.jetbrains.kotlin.lexer.KtTokens
+import org.jetbrains.kotlin.psi.*
+
+class IllegalIdentifierInspection : AbstractKotlinInspection() {
+    override fun buildVisitor(holder: ProblemsHolder, isOnTheFly: Boolean, session: LocalInspectionToolSession): PsiElementVisitor {
+        return object : KtVisitorVoid() {
+            override fun visitElement(element: PsiElement) {
+                if (element.node.elementType != KtTokens.IDENTIFIER) return
+
+                val text = element.text
+                // '`' can't be escaped now
+                if (!text.startsWith('`') || !text.endsWith('`')) return
+
+                val unquotedName = KtPsiUtil.unquoteIdentifier(text)
+                // This is already an error
+                if (unquotedName.isEmpty()) return
+
+                if (!unquotedName.all { isValidDalvikCharacter(it) } && checkAndroidFacet(element)) {
+                    holder.registerProblem(element,
+                                           "Identifier not allowed in Android projects",
+                                           ProblemHighlightType.GENERIC_ERROR,
+                                           RenameIdentifierFix())
+                }
+            }
+
+            fun checkAndroidFacet(element: PsiElement): Boolean {
+                return element.getAndroidFacetForFile() != null || ApplicationManager.getApplication().isUnitTestMode
+            }
+
+            // https://source.android.com/devices/tech/dalvik/dex-format.html#string-syntax
+            fun isValidDalvikCharacter(c: Char) = when (c) {
+                in 'A'..'Z' -> true
+                in 'a'..'z' -> true
+                in '0'..'9' -> true
+                '$', '-', '_' -> true
+                in '\u00a1' .. '\u1fff' -> true
+                in '\u2010' .. '\u2027' -> true
+                in '\u2030' .. '\ud7ff' -> true
+                in '\ue000' .. '\uffef' -> true
+                else -> false
+            }
+        }
+    }
+
+    class RenameIdentifierFix : LocalQuickFix {
+        override fun getName() = "Rename"
+        override fun getFamilyName() = name
+
+        override fun applyFix(project: Project, descriptor: ProblemDescriptor) {
+            val element = descriptor.psiElement ?: return
+            val file = element.containingFile ?: return
+            if (!FileModificationService.getInstance().prepareFileForWrite(file)) return
+            val editorManager = FileEditorManager.getInstance(project)
+            val editor = editorManager.getSelectedEditor(file.virtualFile) ?: return
+            val dataContext = DataManager.getInstance().getDataContext(editor.component)
+            val renameHandler = RenameHandlerRegistry.getInstance().getRenameHandler(dataContext)
+            renameHandler?.invoke(project, arrayOf(element), dataContext);
+        }
+    }
+}

idea/kotlin-android-plugin/src/org/jetbrains/kotlin/android/navigation/KotlinAndroidGotoDeclarationHandler.java

@@ -21,7 +21,6 @@ import com.intellij.codeInsight.navigation.actions.GotoDeclarationHandler;
 import com.intellij.openapi.actionSystem.DataContext;
 import com.intellij.openapi.editor.Editor;
 import com.intellij.psi.PsiElement;
-import com.intellij.psi.PsiFile;
 import com.intellij.psi.xml.XmlElement;
 import org.jetbrains.android.dom.AndroidAttributeValue;
 import org.jetbrains.android.dom.manifest.Manifest;
@@ -35,6 +34,7 @@ import org.jetbrains.android.util.AndroidResourceUtil;
 import org.jetbrains.android.util.AndroidUtils;
 import org.jetbrains.annotations.NotNull;
 import org.jetbrains.annotations.Nullable;
+import org.jetbrains.kotlin.android.AndroidUtilKt;
 import org.jetbrains.kotlin.psi.KtSimpleNameExpression;
 
 import java.util.ArrayList;
@@ -51,12 +51,7 @@ public class KotlinAndroidGotoDeclarationHandler implements GotoDeclarationHandl
             return null;
         }
 
-        PsiFile file = referenceExpression.getContainingFile();
-        if (file == null) {
-            return null;
-        }
-
-        AndroidFacet facet = AndroidFacet.getInstance(file);
+        AndroidFacet facet = AndroidUtilKt.getAndroidFacetForFile(referenceExpression);
         if (facet == null) {
             return null;
         }

idea/src/META-INF/android.xml

@@ -7,6 +7,12 @@
         <psi.treeChangePreprocessor implementation="org.jetbrains.kotlin.android.synthetic.idea.AndroidPsiTreeChangePreprocessor"/>
         <errorHandler implementation="org.jetbrains.kotlin.plugin.android.AndroidExtensionsReportSubmitter"/>
         <gotoDeclarationHandler implementation="org.jetbrains.kotlin.android.synthetic.idea.AndroidGotoDeclarationHandler"/>
+
+        <localInspection implementationClass="org.jetbrains.kotlin.android.inspection.IllegalIdentifierInspection"
+                         displayName="Illegal Android Identifier"
+                         groupName="Kotlin"
+                         enabledByDefault="true"
+                         level="ERROR"/>
     </extensions>
 
     <extensions defaultExtensionNs="org.jetbrains.kotlin">

idea/testData/inspections/androidIllegalIdentifiers/inspectionData/expected.xml

@@ -0,0 +1,46 @@
+<problems>
+    <problem>
+        <file>temp:///src/test.kt</file>
+        <line>7</line>
+        <module>light_idea_test_case</module>
+        <entry_point TYPE="file" FQNAME="temp:///src/test.kt" />
+        <problem_class severity="WARNING" attribute_key="WARNING_ATTRIBUTES">Illegal Android Identifier</problem_class>
+        <description>Illegal Android Identifier</description>
+    </problem>
+
+    <problem>
+        <file>temp:///src/test.kt</file>
+        <line>8</line>
+        <module>light_idea_test_case</module>
+        <entry_point TYPE="file" FQNAME="temp:///src/test.kt" />
+        <problem_class severity="WARNING" attribute_key="WARNING_ATTRIBUTES">Illegal Android Identifier</problem_class>
+        <description>Illegal Android Identifier</description>
+    </problem>
+
+    <problem>
+        <file>temp:///src/test.kt</file>
+        <line>9</line>
+        <module>light_idea_test_case</module>
+        <entry_point TYPE="file" FQNAME="temp:///src/test.kt" />
+        <problem_class severity="WARNING" attribute_key="WARNING_ATTRIBUTES">Illegal Android Identifier</problem_class>
+        <description>Illegal Android Identifier</description>
+    </problem>
+
+    <problem>
+        <file>temp:///src/test.kt</file>
+        <line>10</line>
+        <module>light_idea_test_case</module>
+        <entry_point TYPE="file" FQNAME="temp:///src/test.kt" />
+        <problem_class severity="WARNING" attribute_key="WARNING_ATTRIBUTES">Illegal Android Identifier</problem_class>
+        <description>Illegal Android Identifier</description>
+    </problem>
+
+    <problem>
+        <file>temp:///src/test.kt</file>
+        <line>11</line>
+        <module>light_idea_test_case</module>
+        <entry_point TYPE="file" FQNAME="temp:///src/test.kt" />
+        <problem_class severity="WARNING" attribute_key="WARNING_ATTRIBUTES">Illegal Android Identifier</problem_class>
+        <description>Illegal Android Identifier</description>
+    </problem>
+</problems>

idea/testData/inspections/androidIllegalIdentifiers/inspectionData/inspections.test

@@ -0,0 +1 @@
+// INSPECTION_CLASS: org.jetbrains.kotlin.android.inspection.IllegalIdentifierInspection

idea/testData/inspections/androidIllegalIdentifiers/test.kt

@@ -0,0 +1,11 @@
+val `Kotlin` = 0
+val `Котлин` = 0
+val `ことりん` = 0
+val `§＊！｀` = 0
+val `0a0b0c` = 0
+val `$a-b_c` = 0
+val `with space` = 0 //illegal
+val `a+b` = 0 //illegal
+val `#` = 0 //illegal
+val `!` = 0 //illegal
+val `()` = 0 //illegal

idea/tests/org/jetbrains/kotlin/idea/codeInsight/InspectionTestGenerated.java

@@ -106,6 +106,12 @@ public class InspectionTestGenerated extends AbstractInspectionTest {
             KotlinTestUtils.assertAllTestsPresentInSingleGeneratedClass(this.getClass(), new File("idea/testData/inspections"), Pattern.compile("^(inspections\\.test)$"));
         }
 
+        @TestMetadata("androidIllegalIdentifiers/inspectionData/inspections.test")
+        public void testAndroidIllegalIdentifiers_inspectionData_Inspections_test() throws Exception {
+            String fileName = KotlinTestUtils.navigationMetadata("idea/testData/inspections/androidIllegalIdentifiers/inspectionData/inspections.test");
+            doTest(fileName);
+        }
+
         @TestMetadata("conflictingExtensionProperty/inspectionData/inspections.test")
         public void testConflictingExtensionProperty_inspectionData_Inspections_test() throws Exception {
             String fileName = KotlinTestUtils.navigationMetadata("idea/testData/inspections/conflictingExtensionProperty/inspectionData/inspections.test");