Do not highlight extension methods' bodies

java/java-impl/src/com/intellij/codeInsight/daemon/impl/analysis/HighlightMethodUtil.java

@@ -838,14 +838,19 @@ public class HighlightMethodUtil {
     return null;
   }
 
-
+  @Nullable
   static HighlightInfo checkMethodCanHaveBody(PsiMethod method) {
     if (method.getBody() == null) return null;
     PsiClass aClass = method.getContainingClass();
 
     String message = null;
     if (aClass != null && aClass.isInterface()) {
-      message = JavaErrorMessages.message("interface.methods.cannot.have.body");
+      if (!PsiUtil.isExtensionMethod(method)) {
+        message = JavaErrorMessages.message("interface.methods.cannot.have.body");
+      }
+      else {
+        return HighlightUtil.checkExtensionMethodsFeature(method);
+      }
     }
     else if (method.hasModifierProperty(PsiModifier.ABSTRACT)) {
       message = JavaErrorMessages.message("abstract.methods.cannot.have.a.body");
@@ -853,21 +858,19 @@ public class HighlightMethodUtil {
     else if (method.hasModifierProperty(PsiModifier.NATIVE)) {
       message = JavaErrorMessages.message("native.methods.cannot.have.a.body");
     }
+    if (message == null) return null;
 
-    if (message != null) {
-      TextRange textRange = HighlightNamesUtil.getMethodDeclarationTextRange(method);
-      HighlightInfo info = HighlightInfo.createHighlightInfo(HighlightInfoType.ERROR, textRange, message);
-      QuickFixAction.registerQuickFixAction(info, new DeleteMethodBodyFix(method));
-      if (method.hasModifierProperty(PsiModifier.ABSTRACT) && aClass != null && !aClass.isInterface()) {
-        IntentionAction fix = QUICK_FIX_FACTORY.createModifierListFix(method, PsiModifier.ABSTRACT, false, false);
-        QuickFixAction.registerQuickFixAction(info, fix);
-      }
-      return info;
+    TextRange textRange = HighlightNamesUtil.getMethodDeclarationTextRange(method);
+    HighlightInfo info = HighlightInfo.createHighlightInfo(HighlightInfoType.ERROR, textRange, message);
+    QuickFixAction.registerQuickFixAction(info, new DeleteMethodBodyFix(method));
+    if (method.hasModifierProperty(PsiModifier.ABSTRACT) && aClass != null && !aClass.isInterface()) {
+      IntentionAction fix = QUICK_FIX_FACTORY.createModifierListFix(method, PsiModifier.ABSTRACT, false, false);
+      QuickFixAction.registerQuickFixAction(info, fix);
     }
-    return null;
+    return info;
   }
 
-
+  @Nullable
   static HighlightInfo checkConstructorCallMustBeFirstStatement(PsiReferenceExpression expression) {
     PsiElement methodCall = expression.getParent();
     if (!HighlightUtil.isSuperOrThisMethodCall(methodCall)) return null;

java/java-impl/src/com/intellij/codeInsight/daemon/impl/analysis/HighlightUtil.java

@@ -2481,7 +2481,8 @@ public class HighlightUtil {
     VARARGS(LanguageLevel.JDK_1_5, "feature.varargs"),
     DIAMOND_TYPES(LanguageLevel.JDK_1_7, "feature.diamond.types"),
     MULTI_CATCH(LanguageLevel.JDK_1_7, "feature.multi.catch"),
-    TRY_WITH_RESOURCES(LanguageLevel.JDK_1_7, "feature.try.with.resources");
+    TRY_WITH_RESOURCES(LanguageLevel.JDK_1_7, "feature.try.with.resources"),
+    EXTENSION_METHODS(LanguageLevel.JDK_1_8, "feature.extension.methods");
 
     private final LanguageLevel level;
     private final String key;
@@ -2544,4 +2545,9 @@ public class HighlightUtil {
   public static HighlightInfo checkTryWithResourcesFeature(final PsiResourceVariable resourceVariable) {
     return checkFeature(resourceVariable.getParent(), Feature.TRY_WITH_RESOURCES);
   }
+
+  @Nullable
+  public static HighlightInfo checkExtensionMethodsFeature(final PsiMethod method) {
+    return checkFeature(method, Feature.EXTENSION_METHODS);
+  }
 }

java/java-psi-api/src/com/intellij/psi/util/PsiUtil.java

@@ -318,7 +318,9 @@ public final class PsiUtil extends PsiUtilCore {
   @PsiModifier.ModifierConstant
   @Nullable
   public static String getAccessModifier(int accessLevel) {
-    return accessLevel > accessModifiers.length ? null : accessModifiers[accessLevel - 1];
+    @SuppressWarnings("UnnecessaryLocalVariable") @PsiModifier.ModifierConstant
+    final String modifier = accessLevel > accessModifiers.length ? null : accessModifiers[accessLevel - 1];
+    return modifier;
   }
 
   private static final String[] accessModifiers = {
@@ -952,4 +954,12 @@ public final class PsiUtil extends PsiUtilCore {
   public static boolean isIgnoredName(@Nullable final String name) {
     return "ignore".equals(name) || "ignored".equals(name);
   }
+
+  public static boolean isExtensionMethod(@Nullable final PsiMethod method) {
+    if (method == null) return false;
+    final PsiCodeBlock body = method.getBody();
+    if (body == null) return false;
+    final PsiElement previous = PsiTreeUtil.skipSiblingsBackward(body, PsiComment.class, PsiWhiteSpace.class);
+    return isJavaToken(previous, JavaTokenType.DEFAULT_KEYWORD);
+  }
 }

java/java-psi-impl/src/messages/JavaErrorMessages.properties

@@ -349,6 +349,7 @@ feature.static.imports=Static imports
 feature.for.each=For-each loops
 feature.varargs=Variable arity methods
 feature.diamond.types=Diamond types
-feature.try.with.resources=Try-with-resources
 feature.multi.catch=Multi-catches
+feature.try.with.resources=Try-with-resources
+feature.extension.methods=Extension methods
 insufficient.language.level={0} are not supported at this language level

java/java-tests/testData/codeInsight/daemonCodeAnalyzer/advHighlighting/UnsupportedFeatures.java

@@ -38,4 +38,8 @@ class UnsupportedFeatures {
 
     try <error descr="Try-with-resources are not supported at this language level">(Reader r = new FileReader("/dev/null"))</error> { }
   }
+
+  interface I {
+    <error descr="Extension methods are not supported at this language level">void m() default { }</error>
+  }
 }

java/java-tests/testData/codeInsight/daemonCodeAnalyzer/advHighlighting7/ExtensionMethods.java

@@ -0,0 +1,21 @@
+/*
+ * Copyright 2000-2012 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.
+ */
+class C {
+  interface I {
+    <error descr="Interface methods cannot have body">void m1()</error> { }
+    void m2() default { }
+  }
+}

java/java-tests/testSrc/com/intellij/codeInsight/daemon/LightAdvHighlightingJdk7Test.java

@@ -57,126 +57,36 @@ public class LightAdvHighlightingJdk7Test extends LightDaemonAnalyzerTestCase {
     };
   }
 
-  public void testAllJava15Features() throws Exception {
-    doTest(false, false);
-  }
-
-  public void testEnumSyntheticMethods() throws Exception {
-    doTest(false, false);
-  }
-
-  public void testDuplicateAnnotations() throws Exception {
-    doTest(false, false);
-  }
-
-  public void testSwitchByString() throws Exception {
-    doTest(false, false);
-  }
-
-  public void testSwitchByInaccessibleEnum() throws Exception {
-    doTest(false, false);
-  }
-
-  public void testDiamondPos1() throws Exception {
-    doTest(false, false);
-  }
-
-  public void testDiamondPos2() throws Exception {
-    doTest(false, false);
-  }
-
-  public void testDiamondPos3() throws Exception {
-    doTest(false, false);
-  }
-
-  public void testDiamondPos4() throws Exception {
-    doTest(false, false);
-  }
-
-  public void testDiamondPos5() throws Exception {
-    doTest(false, false);
-  }
-
-
-  public void testDiamondPos6() throws Exception {
-    doTest(false, false);
-  }
-
-  public void testDiamondPos7() throws Exception {
-    doTest(false, false);
-  }
-
-  public void testDiamondNeg15() throws Exception {
-    doTest(false, false);
-  }
-
-  public void testDiamondPos9() throws Exception {
-    doTest(false, false);
-  }
-
-  public void testDiamondNeg1() throws Exception {
-    doTest(false, false);
-  }
-
-  public void testDiamondNeg2() throws Exception {
-    doTest(false, false);
-  }
-
-  public void testDiamondNeg3() throws Exception {
-    doTest(false, false);
-  }
-
-  public void testDiamondNeg4() throws Exception {
-    doTest(false, false);
-  }
-
-  public void testDiamondNeg5() throws Exception {
-    doTest(false, false);
-  }
-
-  public void testDiamondNeg6() throws Exception {
-    doTest(false, false);
-  }
-
-  public void testDiamondNeg7() throws Exception {
-    doTest(false, false);
-  }
-
-  public void testDiamondNeg8() throws Exception {
-    doTest(false, false);
-  }
-
-  public void testDiamondNeg9() throws Exception {
-    doTest(false, false);
-  }
-
-  public void testDiamondNeg10() throws Exception {
-    doTest(false, false);
-  }
-
-  public void testDiamondNeg11() throws Exception {
-    doTest(false, false);
-  }
-
-  public void testDiamondNeg12() throws Exception {
-    doTest(false, false);
-  }
-
-  public void testDiamondNeg13() throws Exception {
-    doTest(false, false);
-  }
-
-  public void testDiamondNeg14() throws Exception {
-    doTest(false, false);
-  }
-
-  public void testDiamondMisc() throws Exception {
-    doTest(false, false);
-  }
-
-  public void testHighlightInaccessibleFromClassModifierList() throws Exception {
-    doTest(false, false);
-  }
+  public void testAllJava15Features() throws Exception { doTest(false, false); }
+  public void testEnumSyntheticMethods() throws Exception { doTest(false, false); }
+  public void testDuplicateAnnotations() throws Exception { doTest(false, false); }
+  public void testSwitchByString() throws Exception { doTest(false, false); }
+  public void testSwitchByInaccessibleEnum() throws Exception { doTest(false, false); }
+  public void testDiamondPos1() throws Exception { doTest(false, false); }
+  public void testDiamondPos2() throws Exception { doTest(false, false); }
+  public void testDiamondPos3() throws Exception { doTest(false, false); }
+  public void testDiamondPos4() throws Exception { doTest(false, false); }
+  public void testDiamondPos5() throws Exception { doTest(false, false); }
+  public void testDiamondPos6() throws Exception { doTest(false, false); }
+  public void testDiamondPos7() throws Exception { doTest(false, false); }
+  public void testDiamondNeg15() throws Exception { doTest(false, false); }
+  public void testDiamondPos9() throws Exception { doTest(false, false); }
+  public void testDiamondNeg1() throws Exception { doTest(false, false); }
+  public void testDiamondNeg2() throws Exception { doTest(false, false); }
+  public void testDiamondNeg3() throws Exception { doTest(false, false); }
+  public void testDiamondNeg4() throws Exception { doTest(false, false); }
+  public void testDiamondNeg5() throws Exception { doTest(false, false); }
+  public void testDiamondNeg6() throws Exception { doTest(false, false); }
+  public void testDiamondNeg7() throws Exception { doTest(false, false); }
+  public void testDiamondNeg8() throws Exception { doTest(false, false); }
+  public void testDiamondNeg9() throws Exception { doTest(false, false); }
+  public void testDiamondNeg10() throws Exception { doTest(false, false); }
+  public void testDiamondNeg11() throws Exception { doTest(false, false); }
+  public void testDiamondNeg12() throws Exception { doTest(false, false); }
+  public void testDiamondNeg13() throws Exception { doTest(false, false); }
+  public void testDiamondNeg14() throws Exception { doTest(false, false); }
+  public void testDiamondMisc() throws Exception { doTest(false, false); }
+  public void testHighlightInaccessibleFromClassModifierList() throws Exception { doTest(false, false); }
 
   public void testDynamicallyAddIgnoredAnnotations() throws Exception {
     ExtensionPoint<EntryPoint> point = Extensions.getRootArea().getExtensionPoint(ExtensionPoints.DEAD_CODE_TOOL);
@@ -242,46 +152,21 @@ public class LightAdvHighlightingJdk7Test extends LightDaemonAnalyzerTestCase {
     }
   }
 
-  public void testNumericLiterals() throws Exception {
-    doTest(false, false);
-  }
-
-  public void testMultiCatch() throws Exception {
-    doTest(false, false);
-  }
-
-  public void testTryWithResources() throws Exception {
-    doTest(false, false);
-  }
+  public void testNumericLiterals() throws Exception { doTest(false, false); }
+  public void testMultiCatch() throws Exception { doTest(false, false); }
+  public void testTryWithResources() throws Exception { doTest(false, false); }
 
   public void testTryWithResourcesWarn() throws Exception {
     enableInspectionTool(new DefUseInspection());
     doTest(true, false);
   }
 
-  public void testSafeVarargsApplicability() throws Exception {
-    doTest(true, false);
-  }
-
-  public void testUncheckedGenericsArrayCreation() throws Exception {
-    doTest(true, false);
-  }
-
-  public void testPreciseRethrow() throws Exception {
-    doTest(false, false);
-  }
-
-  public void testImprovedCatchAnalysis() throws Exception {
-    doTest(true, false);
-  }
-
-  public void testJavacQuirks() throws Exception {
-    doTest(true, false);
-  }
-
-  public void testPolymorphicTypeCast() throws Exception {
-    doTest(true, false);
-  }
+  public void testSafeVarargsApplicability() throws Exception { doTest(true, false); }
+  public void testUncheckedGenericsArrayCreation() throws Exception { doTest(true, false); }
+  public void testPreciseRethrow() throws Exception { doTest(false, false); }
+  public void testImprovedCatchAnalysis() throws Exception { doTest(true, false); }
+  public void testJavacQuirks() throws Exception { doTest(true, false); }
+  public void testPolymorphicTypeCast() throws Exception { doTest(true, false); }
 
   public void testErasureClashConfusion() throws Exception {
     enableInspectionTool(new UnusedDeclarationInspection());
@@ -293,16 +178,9 @@ public class LightAdvHighlightingJdk7Test extends LightDaemonAnalyzerTestCase {
     doTest(true, false);
   }
 
-  public void testSuperBound() throws Exception {
-    doTest(false, false);
-  }
-
-  public void testExtendsBound() throws Exception {
-    doTest(false, false);
-  }
-
+  public void testSuperBound() throws Exception { doTest(false, false); }
+  public void testExtendsBound() throws Exception { doTest(false, false); }
   public void testIDEA84533() throws Exception { doTest(false, false); }
-  
-  public void testClassLiteral() throws Exception { doTest(false, false);}
+  public void testClassLiteral() throws Exception { doTest(false, false); }
+  public void testExtensionMethods() throws Exception { doTest(false, false); }
 }
-