silly assignment: ignore non-trivial casts involving primitives (IDEA-146830)

java/java-analysis-impl/src/com/intellij/codeInspection/sillyAssignment/SillyAssignmentInspectionBase.java

@@ -96,28 +96,45 @@ public class SillyAssignmentInspectionBase extends BaseJavaBatchLocalInspectionT
     PsiExpression lExpression = assignment.getLExpression();
     PsiExpression rExpression = assignment.getRExpression();
     if (rExpression == null) return;
+
     lExpression = PsiUtil.deparenthesizeExpression(lExpression);
-    rExpression = PsiUtil.deparenthesizeExpression(rExpression);
     if (!(lExpression instanceof PsiReferenceExpression)) return;
+    PsiReferenceExpression lRef = (PsiReferenceExpression)lExpression;
+    final PsiVariable variable = (PsiVariable)lRef.resolve();
+    if (variable == null) return;
+
+    rExpression = deparenthesizeRExpr(rExpression, variable);
+
     PsiReferenceExpression rRef;
     if (!(rExpression instanceof PsiReferenceExpression)) {
       if (!(rExpression instanceof PsiAssignmentExpression)) return;
       final PsiAssignmentExpression rAssignmentExpression = (PsiAssignmentExpression)rExpression;
-      final PsiExpression assignee = PsiUtil.deparenthesizeExpression(rAssignmentExpression.getLExpression());
+      final PsiExpression assignee = deparenthesizeRExpr(rAssignmentExpression.getLExpression(), variable);
       if (!(assignee instanceof PsiReferenceExpression)) return;
       rRef = (PsiReferenceExpression)assignee;
     } else {
       rRef = (PsiReferenceExpression)rExpression;
     }
-    PsiReferenceExpression lRef = (PsiReferenceExpression)lExpression;
     PsiManager manager = assignment.getManager();
     if (!sameInstanceReferences(lRef, rRef, manager)) return;
-    final PsiVariable variable = (PsiVariable)lRef.resolve();
-    if (variable == null) return;
     holder.registerProblem(assignment, InspectionsBundle.message("assignment.to.itself.problem.descriptor", variable.getName()),
                            ProblemHighlightType.LIKE_UNUSED_SYMBOL, createRemoveAssignmentFix());
   }
 
+  private static PsiExpression deparenthesizeRExpr(PsiExpression rExpression, PsiVariable variable) {
+    rExpression = PsiUtil.skipParenthesizedExprDown(rExpression);
+    if (rExpression instanceof PsiTypeCastExpression) {
+      final PsiTypeElement castTypeElement = ((PsiTypeCastExpression)rExpression).getCastType();
+      if (castTypeElement != null &&
+          castTypeElement.getType() instanceof PsiPrimitiveType &&
+          variable.getType().equalsToText(CommonClassNames.JAVA_LANG_OBJECT)) {
+        return rExpression;
+      }
+      return PsiUtil.deparenthesizeExpression(rExpression);
+    }
+    return rExpression;
+  }
+
   protected LocalQuickFix createRemoveAssignmentFix() {
     return null;
   }

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

@@ -21,6 +21,9 @@ class a {
     <warning descr="Variable 'i' is assigned to itself">i = i</warning>;
     <warning descr="Variable 'i' is assigned to itself">i = (int)i</warning>;
     <warning descr="Variable 'o' is assigned to itself">o = ((Object)(o))</warning>;
+    Object o1 = <warning descr="Variable 'o' is assigned to itself">o = ((Object)(o))</warning>;
+    System.out.println(o1);
+    o = (double)o;
   }
   void f4() {
     fpanel.getSize().height = this.fpanel.getSize().height; // not silly. Are you sure you can bet getSize() has no side effects? 

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

@@ -148,7 +148,10 @@ public class LightAdvHighlightingTest extends LightDaemonAnalyzerTestCase {
   public void testUnclosedBlockComment() { doTest(false, false); }
   public void testUnclosedComment() { doTest(false, false); }
   public void testUnclosedDecl() { doTest(false, false); }
-  public void testSillyAssignment() { doTest(true, false); }
+  public void testSillyAssignment() {
+    LanguageLevelProjectExtension.getInstance(getJavaFacade().getProject()).setLanguageLevel(LanguageLevel.JDK_1_7);
+    doTest(true, false);
+  }
   public void testTernary() { doTest(false, false); }
   public void testDuplicateClass() { doTest(false, false); }
   public void testCatchType() { doTest(false, false); }