java8: static method with body is allowed in interface (IDEA-100334)

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

@@ -853,21 +853,24 @@ public class HighlightMethodUtil {
   @Nullable
   static HighlightInfo checkMethodCanHaveBody(PsiMethod method) {
     PsiClass aClass = method.getContainingClass();
-    boolean hasBody = method.getBody() == null;
+    boolean hasNoBody = method.getBody() == null;
     boolean isInterface = aClass != null && aClass.isInterface();
     boolean isExtension = method.hasModifierProperty(PsiModifier.DEFAULT);
+    boolean isStatic = method.hasModifierProperty(PsiModifier.STATIC);
 
     String message = null;
-    if (hasBody) {
+    if (hasNoBody) {
       if (isExtension) {
         message = JavaErrorMessages.message("extension.method.should.have.a.body");
+      } else if (isInterface && isStatic) {
+        message = "Static methods in interfaces should have a body";
       }
     }
     else if (isInterface) {
-      if (!isExtension) {
+      if (!isExtension && !isStatic) {
         message = JavaErrorMessages.message("interface.methods.cannot.have.body");
       }
-      else {
+      else if (isExtension) {
         return HighlightUtil.checkExtensionMethodsFeature(method);
       }
     }
@@ -884,7 +887,7 @@ public class HighlightMethodUtil {
 
     TextRange textRange = HighlightNamesUtil.getMethodDeclarationTextRange(method);
     HighlightInfo info = HighlightInfo.createHighlightInfo(HighlightInfoType.ERROR, textRange, message);
-    if (hasBody) {
+    if (hasNoBody) {
       QuickFixAction.registerQuickFixAction(info, new DeleteMethodBodyFix(method));
     }
     if (method.hasModifierProperty(PsiModifier.ABSTRACT) && isInterface) {

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

@@ -161,7 +161,13 @@ public class HighlightUtil extends HighlightUtilBase {
 
     Set<String> incompatibles = incompatibleModifiersHash.get(modifier);
     if (incompatibles == null) return null;
+    final boolean level8OrHigher = PsiUtil.isLanguageLevel8OrHigher(modifierList);
     for (@PsiModifier.ModifierConstant String incompatible : incompatibles) {
+      if (level8OrHigher) {
+        if (modifier.equals(PsiModifier.STATIC) && incompatible.equals(PsiModifier.ABSTRACT)){
+          continue;
+        }
+      }
       if (modifierList.hasModifierProperty(incompatible)) {
         return incompatible;
       }

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

@@ -50,7 +50,7 @@ class D {
 }
 
 interface IllegalMods {
-  <error descr="Illegal combination of modifiers: 'static' and 'abstract'">static</error> void m1();
+  <error descr="Static methods in interfaces should have a body">static void m1()</error>;
   <error descr="Illegal combination of modifiers: 'static' and 'default'">static</error> void m2() default { }
   <error descr="Illegal combination of modifiers: 'static' and 'default'">static</error> <error descr="Illegal combination of modifiers: 'default' and 'static'">default</error> void m3() { }
 

java/java-tests/testData/codeInsight/daemonCodeAnalyzer/lambda/interfaceMethods/staticMethod.java

@@ -0,0 +1,4 @@
+interface Foo {
+  public static void bar1() {}
+  public <error descr="Illegal combination of modifiers: 'abstract' and 'static'">abstract</error> static void bar2() {}
+}

java/java-tests/testSrc/com/intellij/codeInsight/daemon/lambda/Interface8MethodsHighlightingTest.java

@@ -0,0 +1,31 @@
+/*
+ * Copyright 2000-2013 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 com.intellij.codeInsight.daemon.lambda;
+
+import com.intellij.codeInsight.daemon.LightDaemonAnalyzerTestCase;
+import org.jetbrains.annotations.NonNls;
+
+public class Interface8MethodsHighlightingTest extends LightDaemonAnalyzerTestCase {
+  @NonNls static final String BASE_PATH = "/codeInsight/daemonCodeAnalyzer/lambda/interfaceMethods";
+
+  public void testStaticMethod() throws Exception {
+    doTest();
+  }
+
+  private void doTest() throws Exception {
+    doTest(BASE_PATH + "/" + getTestName(false) + ".java", false, false);
+  }
+}

java/java-tests/testSrc/com/intellij/codeInsight/daemon/quickFix/ModifierTest.java

@@ -1,5 +1,7 @@
 package com.intellij.codeInsight.daemon.quickFix;
 
+import com.intellij.pom.java.LanguageLevel;
+
 public class ModifierTest extends LightQuickFixTestCase {
   public void test() throws Exception { doAllTests(); }
 
@@ -7,4 +9,9 @@ public class ModifierTest extends LightQuickFixTestCase {
   protected String getBasePath() {
     return "/codeInsight/daemonCodeAnalyzer/quickFix/modifier";
   }
+
+  @Override
+  protected LanguageLevel getLanguageLevel() {
+    return LanguageLevel.JDK_1_7;
+  }
 }