Don't peer at the identifiers on the LHS of assignments in AlreadyChe…

…cked. You need really weird circumstances to trigger this. Note the `if (false)` in the test, which renders `a` effectively final despite it having an assignment. PiperOrigin-RevId: 584910485
google · Nov 24, 2023 · 5c875ad · 5c875ad
1 parent 83d2ed5
commit 5c875ad
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Showing 2 changed files with 27 additions and 2 deletions.
diff --git a/core/src/main/java/com/google/errorprone/bugpatterns/AlreadyChecked.java b/core/src/main/java/com/google/errorprone/bugpatterns/AlreadyChecked.java
@@ -32,10 +32,12 @@
 import com.google.errorprone.bugpatterns.threadsafety.ConstantExpressions.ConstantExpression;
 import com.google.errorprone.bugpatterns.threadsafety.ConstantExpressions.Truthiness;
 import com.google.errorprone.matchers.Description;
+import com.sun.source.tree.AssignmentTree;
 import com.sun.source.tree.BlockTree;
 import com.sun.source.tree.CompilationUnitTree;
 import com.sun.source.tree.ConditionalExpressionTree;
 import com.sun.source.tree.ExpressionTree;
+import com.sun.source.tree.IdentifierTree;
 import com.sun.source.tree.IfTree;
 import com.sun.source.tree.LambdaExpressionTree;
 import com.sun.source.tree.MethodInvocationTree;
@@ -78,11 +80,9 @@ private final class IfScanner extends SuppressibleTreePathScanner<Void, Void> {
 
     private final Multiset<ConstantExpression> truths = HashMultiset.create();
     private final Multiset<ConstantExpression> falsehoods = HashMultiset.create();
-    private final VisitorState state;
 
     private IfScanner(VisitorState state) {
       super(state);
-      this.state = state;
     }
 
     @Override
@@ -210,6 +210,13 @@ public Void scan(Tree tree, Void unused) {
           || !isSameType(getType(tree), state.getSymtab().booleanType, state)) {
         return super.scan(tree, null);
       }
+
+      if (tree instanceof IdentifierTree
+          && getCurrentPath().getLeaf() instanceof AssignmentTree
+          && ((AssignmentTree) getCurrentPath().getLeaf()).getVariable().equals(tree)) {
+        return super.scan(tree, null);
+      }
+
       constantExpressions
           .constantExpression((ExpressionTree) tree, state)
           .ifPresent(

diff --git a/core/src/test/java/com/google/errorprone/bugpatterns/AlreadyCheckedTest.java b/core/src/test/java/com/google/errorprone/bugpatterns/AlreadyCheckedTest.java
@@ -516,4 +516,22 @@ public void i3914() {
             "}")
         .doTest();
   }
+
+  @Test
+  public void b312047923() {
+    helper
+        .addSourceLines(
+            "Test.java",
+            "class Test {",
+            "  void test() {",
+            "    boolean a = true;",
+            "    loop: while (true) {",
+            "      if (false && a) {",
+            "        a = false;",
+            "      } else {}",
+            "    }",
+            "  }",
+            "}")
+        .doTest();
+  }
 }