Recognize AutoValue extension generated code in ClassInitializationDeadlock and AutoValueSubclassLeaked

core/src/main/java/com/google/errorprone/bugpatterns/AutoValueSubclassLeaked.java

@@ -39,6 +39,7 @@
 import com.sun.tools.javac.code.Symbol;
 import com.sun.tools.javac.code.Symbol.ClassSymbol;
 import com.sun.tools.javac.code.Type;
+import java.util.regex.Pattern;
 
 /** Matches {@code AutoValue_} uses outside the containing file. */
 @BugPattern(
@@ -55,6 +56,8 @@
 public final class AutoValueSubclassLeaked extends BugChecker
     implements CompilationUnitTreeMatcher {
 
+  private static final Pattern AUTO_VALUE_PREFIX = Pattern.compile("\\$*AutoValue_.*");
+
   @Override
   public Description matchCompilationUnit(CompilationUnitTree tree, VisitorState state) {
     ImmutableSet<Type> autoValueClassesFromThisFile = findAutoValueClasses(tree, state);
@@ -91,7 +94,7 @@ public Void visitIdentifier(IdentifierTree identifierTree, Void unused) {
       private void handle(Tree tree) {
         Symbol symbol = getSymbol(tree);
         if (symbol instanceof ClassSymbol
-            && symbol.getSimpleName().toString().startsWith("AutoValue_")
+            && AUTO_VALUE_PREFIX.matcher(symbol.getSimpleName().toString()).matches()
             && autoValueClassesFromThisFile.stream()
                 .noneMatch(av -> isSubtype(symbol.type, av, state))) {
           state.reportMatch(describeMatch(tree));

core/src/main/java/com/google/errorprone/bugpatterns/ClassInitializationDeadlock.java

@@ -48,11 +48,15 @@
 import com.sun.tools.javac.code.Symbol.ClassSymbol;
 import com.sun.tools.javac.code.Type;
 import com.sun.tools.javac.code.Types;
+import java.util.regex.Pattern;
 import javax.lang.model.element.ElementKind;
 
 /** See the summary. */
 @BugPattern(summary = "Possible class initialization deadlock", severity = WARNING)
 public class ClassInitializationDeadlock extends BugChecker implements BugChecker.ClassTreeMatcher {
+
+  private static final Pattern AUTO_VALUE_PREFIX = Pattern.compile("\\$*AutoValue_.*");
+
   @Override
   public Description matchClass(ClassTree tree, VisitorState state) {
     ClassSymbol classSymbol = getSymbol(tree);
@@ -211,7 +215,7 @@ boolean nonPrivateInstantiator(ClassSymbol use) {
       // methods), it can't be directly instantiated outside the current file.
       return false;
     }
-    if (use.getSimpleName().toString().startsWith("AutoValue_")) {
+    if (AUTO_VALUE_PREFIX.matcher(use.getSimpleName().toString()).matches()) {
       // AutoValue generated code is necessarily package-private, but should only be  accessed
       // within the declaration of the corresponding base class. See also the discussion of
       // AutoValue in

core/src/test/java/com/google/errorprone/bugpatterns/AutoValueSubclassLeakedTest.java

@@ -124,4 +124,33 @@ public void generatedCode() {
             "}")
         .doTest();
   }
+
+  @Test
+  public void positiveAutoValueExtension() {
+    helper
+        .addSourceLines(
+            "$$AutoValue_Foo.java", //
+            "package test;",
+            "class $$AutoValue_Foo extends Test.Foo {",
+            "}")
+        .addSourceLines(
+            "Test.java",
+            "package test;",
+            "import com.google.auto.value.AutoValue;",
+            "class Test {",
+            "  @AutoValue",
+            "  abstract static class Foo {",
+            "  }",
+            "}")
+        .addSourceLines(
+            "Bar.java",
+            "package test;",
+            "class Bar {",
+            "  public static Test.Foo create() {",
+            "    // BUG: Diagnostic contains:",
+            "    return new $$AutoValue_Foo();",
+            "  }",
+            "}")
+        .doTest();
+  }
 }

core/src/test/java/com/google/errorprone/bugpatterns/ClassInitializationDeadlockTest.java

@@ -309,4 +309,21 @@ public void nonNestedSubclass() {
             "class B extends A {}")
         .doTest();
   }
+
+  @Test
+  public void negativeAutoValueExtension() {
+    testHelper
+        .addSourceLines(
+            "$$AutoValue_Foo.java", //
+            "class $$AutoValue_Foo extends Foo {",
+            "}")
+        .addSourceLines(
+            "A.java",
+            "import com.google.auto.value.AutoValue;",
+            "@AutoValue",
+            "abstract class Foo {",
+            "  private static final Foo FOO = new $$AutoValue_Foo();",
+            "}")
+        .doTest();
+  }
 }