fix issue 1472 (#1478)

CHANGELOG.md

@@ -10,6 +10,7 @@ Currently the versioning policy of this project follows [Semantic Versioning v2.
 - Inconsistency in the description of `DLS_DEAD_LOCAL_INCREMENT_IN_RETURN`, `VO_VOLATILE_INCREMENT` and `QF_QUESTIONABLE_FOR_LOOP` ([#1470](https://github.com/spotbugs/spotbugs/issues/1470))
 - Should issue warning for SecureRandom object created and used only once ([#1464](https://github.com/spotbugs/spotbugs/issues/1464))
 - False positive OBL_UNSATIFIED_OBLIGATION with try with resources ([#79](https://github.com/spotbugs/spotbugs/issues/79))
+- `SA_LOCAL_SELF_COMPUTATION` bug  ([#1472](https://github.com/spotbugs/spotbugs/issues/1472))
 
 ## 4.2.2 - 2021-03-03
 

spotbugs-tests/src/test/java/edu/umd/cs/findbugs/detect/Issue1472Test.java

@@ -0,0 +1,24 @@
+package edu.umd.cs.findbugs.detect;
+
+import edu.umd.cs.findbugs.AbstractIntegrationTest;
+import edu.umd.cs.findbugs.test.matcher.BugInstanceMatcher;
+import edu.umd.cs.findbugs.test.matcher.BugInstanceMatcherBuilder;
+import org.junit.Test;
+
+import static edu.umd.cs.findbugs.test.CountMatcher.containsExactly;
+import static org.junit.Assert.assertThat;
+
+
+/**
+ * @see <a href="https://github.com/spotbugs/spotbugs/issues/1472">GitHub issue #1472</a>
+ */
+public class Issue1472Test extends AbstractIntegrationTest {
+    @Test
+    public void test() {
+        performAnalysis("ghIssues/Issue1472.class");
+        BugInstanceMatcher bugTypeMatcher = new BugInstanceMatcherBuilder()
+                .bugType("SA_LOCAL_SELF_COMPUTATION")
+                .build();
+        assertThat(getBugCollection(), containsExactly(4, bugTypeMatcher));
+    }
+}

spotbugs/src/main/java/edu/umd/cs/findbugs/detect/FindSelfComparison.java

@@ -322,7 +322,7 @@ private void checkForSelfOperation(int opCode, String op) {
                 bugAccumulator.accumulateBug(bug, this);
             }
 
-            else if (opCode == Const.IXOR && item0.sameValue(item1)) {
+            else if (item0.sameValue(item1)) {
                 LocalVariableAnnotation localVariableAnnotation = LocalVariableAnnotation.getLocalVariableAnnotation(this, item0);
                 if (localVariableAnnotation != null) {
                     bugAccumulator.accumulateBug(

spotbugsTestCases/src/java/ghIssues/Issue1472.java

@@ -0,0 +1,23 @@
+package ghIssues;
+
+public class Issue1472 {
+    int testSA_LOCAL_SELF_COMPUTATION(){
+        int flags = 1;
+        return flags ^ flags; // expeected SA_LOCAL_SELF_COMPUTATION
+    }
+
+    int testSA_LOCAL_SELF_COMPUTATION1(){
+        int flags = 1;
+        return flags & flags; //  expeected SA_LOCAL_SELF_COMPUTATION
+    }
+
+    int testSA_LOCAL_SELF_COMPUTATION2(){
+        int flags = 1;
+        return flags - flags; //  expeected SA_LOCAL_SELF_COMPUTATION
+    }
+
+    int testSA_LOCAL_SELF_COMPUTATION3(){
+        int flags = 1;
+        return flags | flags; //  expeected SA_LOCAL_SELF_COMPUTATION
+    }
+}