ReturnValueIgnored: include methods defined in java.lang.Object.

PiperOrigin-RevId: 375914006
google · May 26, 2021 · e9aa66a · e9aa66a
1 parent 0a6f515
commit e9aa66a
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Showing 2 changed files with 34 additions and 1 deletion.
diff --git a/core/src/main/java/com/google/errorprone/bugpatterns/ReturnValueIgnored.java b/core/src/main/java/com/google/errorprone/bugpatterns/ReturnValueIgnored.java
@@ -281,6 +281,17 @@ private static boolean functionalMethod(ExpressionTree tree, VisitorState state)
               .onDescendantOf(PROTO_MESSAGE + ".Builder")
               .namedAnyOf("build", "buildPartial"));
 
+  private static final Matcher<ExpressionTree> OBJECT_METHODS =
+      anyOf(
+          instanceMethod()
+              .onDescendantOf("java.lang.Object")
+              .namedAnyOf("getClass", "hashCode", "clone", "toString")
+              .withParameters(),
+          instanceMethod()
+              .onDescendantOf("java.lang.Object")
+              .namedAnyOf("equals")
+              .withParameters("java.lang.Object"));
+
   private static final Matcher<? super ExpressionTree> SPECIALIZED_MATCHER =
       anyOf(
           RETURNS_SAME_TYPE,
@@ -303,12 +314,14 @@ private static boolean functionalMethod(ExpressionTree tree, VisitorState state)
   public ReturnValueIgnored(ErrorProneFlags flags) {
     boolean checkOptional = flags.getBoolean("ReturnValueIgnored:MoreOptional").orElse(true);
     boolean checkMoreMap = flags.getBoolean("ReturnValueIgnored:MoreMap").orElse(true);
+    boolean objectMethods = flags.getBoolean("ReturnValueIgnored:ObjectMethods").orElse(true);
 
     this.matcher =
         anyOf(
             SPECIALIZED_MATCHER,
             checkOptional ? MORE_OPTIONAL_METHODS : nothing(),
-            checkMoreMap ? MORE_MAP_METHODS : nothing());
+            checkMoreMap ? MORE_MAP_METHODS : nothing(),
+            objectMethods ? OBJECT_METHODS : nothing());
   }
 
   @Override

diff --git a/core/src/test/java/com/google/errorprone/bugpatterns/ReturnValueIgnoredTest.java b/core/src/test/java/com/google/errorprone/bugpatterns/ReturnValueIgnoredTest.java
@@ -550,4 +550,24 @@ public void testCollectionToArray_java8() {
             "}")
         .doTest();
   }
+
+  @Test
+  public void objectMethods() {
+    compilationHelper
+        .addSourceLines(
+            "Test.java",
+            "class Test {",
+            "  void test(Test t, Object o) {",
+            "    // BUG: Diagnostic contains:",
+            "    t.equals(o);",
+            "    // BUG: Diagnostic contains:",
+            "    o.equals(t);",
+            "    // BUG: Diagnostic contains:",
+            "    t.hashCode();",
+            "    // BUG: Diagnostic contains:",
+            "    t.getClass();",
+            "  }",
+            "}")
+        .doTest();
+  }
 }