[java-highlighting] IDEA-284251 Better unreachable statement highlighting

GitOrigin-RevId: 738ac8d77fdf9000f2cb8c791a7ed3bfbddafca7

java/java-psi-impl/src/com/intellij/psi/controlFlow/ControlFlowUtil.java

@@ -1182,8 +1182,8 @@ public final class ControlFlowUtil {
     @Nullable
     private static PsiElement getUnreachableExpressionParent(@Nullable PsiElement element) {
       if (element instanceof PsiExpression) {
-        final PsiElement expression = PsiTreeUtil.findFirstParent(element, e -> !(e.getParent() instanceof PsiParenthesizedExpression));
-        if (expression != null) {
+        PsiElement expression = PsiTreeUtil.findFirstParent(element, e -> !(e.getParent() instanceof PsiParenthesizedExpression));
+        while (expression != null) {
           final PsiElement parent = expression.getParent();
           if (parent instanceof PsiExpressionStatement) {
             return getUnreachableStatementParent(parent);
@@ -1194,6 +1194,11 @@ public final class ControlFlowUtil {
               parent instanceof PsiForeachStatement && ((PsiForeachStatement)parent).getIteratedValue() == expression) {
             return parent;
           }
+          if (parent instanceof PsiExpression) {
+            expression = parent;
+          } else {
+            break;
+          }
         }
       }
       return null;

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

@@ -11,12 +11,43 @@ class WithCondition {
   }
 
   void testIf2(boolean b) {
+    return;
+    <error descr="Unreachable statement">if</error> (b == true) {
+      System.out.println("Never");
+    }
+    else {
+      System.out.println("Never ever");
+    }
+  }
+
+  void testIf3(boolean b) {
     return;
     <error descr="Unreachable statement">if</error> ((b)) {
       System.out.println("Never");
     }
   }
 
+  void testIf4() {
+    return;
+    <error descr="Unreachable statement">if</error> (Math.abs(1) > 2) {
+      System.out.println();
+    }
+  }
+
+  void testIf5() {
+    return;
+    <error descr="Unreachable statement">if</error> (new int[] {1,2,3}.length == 3) {
+      System.out.println();
+    }
+  }
+
+  void testIf6(boolean b, boolean c, boolean d) {
+    return;
+    <error descr="Unreachable statement">if</error> (b ? c : d) {
+      System.out.println();
+    }
+  }
+
   void testSwitch(int b) {
     return;
     <error descr="Unreachable statement">switch</error> (b) {
@@ -25,6 +56,14 @@ class WithCondition {
     }
   }
 
+  void testSwitch2(int b) {
+    return;
+    <error descr="Unreachable statement">switch</error> (b+1) {
+      case 1:
+        System.out.println("Never");
+    }
+  }
+
   void testFor1(int b) {
     return;
     <error descr="Unreachable statement">for</error> (int i = 0; i < b; i++) {
@@ -77,6 +116,13 @@ class WithCondition {
     }
   }
 
+  void testWhile2(boolean b) {
+    return;
+    <error descr="Unreachable statement">while</error> (!b) {
+      System.out.println("Never");
+    }
+  }
+
   void testDoWhile1(boolean b) {
     return;
     <error descr="Unreachable statement">do</error> System.out.println("Never");
@@ -90,4 +136,9 @@ class WithCondition {
     }
     while (b);
   }
+
+  int testReturn() {
+    return 1;
+    <error descr="Unreachable statement">return 2;</error>
+  }
 }