Allow private methods to inherit default annotations from package or …

…class scope (#1222)

* refs #374: reproduce reported problem

* allow private methods to inherit default annotations

Remove the restriction that a method must not be private in order to
inherit default annotations from package or class scope.

Resolves #374.

* bump year in license header

* add a comment in changelog as per the PR template

* ./gradlew spotlessApply

* address pr comments

- fix copyright attribution
- move entry in changelog

Co-authored-by: Ritee <chenh0510@qq.com>

CHANGELOG.md

@@ -8,6 +8,7 @@ Currently the versioning policy of this project follows [Semantic Versioning v2.
 ### Fixed
 * [A meaningless exception data from `SAXBugCollectionHandler`](https://lgtm.com/projects/g/spotbugs/spotbugs/rev/a77ab08634687b7791e902636996ab6184462693)
 * Use URI for files instead of converting string to URI each time. Fixes tests on Windows.
+* Allow private methods to inherit default annotations from package or class scope. ([#374](https://github.com/spotbugs/spotbugs/issues/374))
 
 ### Added
 * Implement [issue 390](https://github.com/spotbugs/spotbugs/issues/390) as a detector, `DontAssertInstanceofInTests`, which reports bugs of type `JUA_DONT_ASSERT_INSTANCEOF_IN_TESTS`.

spotbugs-tests/src/test/java/edu/umd/cs/findbugs/detect/Issue374Test.java

@@ -0,0 +1,46 @@
+/*
+ * Contributions to SpotBugs
+ * Copyright (C) 2020, ritchan
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+ */
+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/374">GitHub issue</a>
+ */
+public class Issue374Test extends AbstractIntegrationTest {
+    @Test
+    public void test() {
+        performAnalysis(
+                "ghIssues/issue374/package-info.class",
+                "ghIssues/issue374/ClassLevel.class",
+                "ghIssues/issue374/MethodLevel.class",
+                "ghIssues/issue374/PackageLevel.class");
+        BugInstanceMatcher matcher = new BugInstanceMatcherBuilder()
+                .bugType("NP_PARAMETER_MUST_BE_NONNULL_BUT_MARKED_AS_NULLABLE")
+                .build();
+        assertThat(getBugCollection(), containsExactly(3, matcher));
+    }
+}

spotbugs/src/main/java/edu/umd/cs/findbugs/ba/jsr305/TypeQualifierApplications.java

@@ -986,11 +986,6 @@ private static TypeQualifierAnnotation computeEffectiveTypeQualifierAnnotation(T
             // default annotations
         }
 
-        /** private methods don't inherit from class or package scope */
-        if (xmethod.isPrivate()) {
-            stopAtMethodScope = true;
-        }
-
         boolean stopAtClassScope = false;
 
         if (!xmethod.isPublic() && !xmethod.isProtected() && (xmethod.isStatic() || "<init>".equals(xmethod.getName()))) {

spotbugsTestCases/src/java/ghIssues/issue374/ClassLevel.java

@@ -0,0 +1,19 @@
+package ghIssues.issue374;
+
+import javax.annotation.Nullable;
+import javax.annotation.ParametersAreNonnullByDefault;
+
+@ParametersAreNonnullByDefault
+public class ClassLevel {
+    public String method() {
+        return methodNullable(null);
+    }
+
+    private String methodNullable(@Nullable final String test) {
+        return methodNonNull(test);
+    }
+
+    private String methodNonNull(final String test) {
+        return test;
+    }
+}

spotbugsTestCases/src/java/ghIssues/issue374/MethodLevel.java

@@ -0,0 +1,19 @@
+package ghIssues.issue374;
+
+import javax.annotation.Nullable;
+import javax.annotation.ParametersAreNonnullByDefault;
+
+public class MethodLevel {
+    public String method() {
+        return methodNullable(null);
+    }
+
+    private String methodNullable(@Nullable final String test) {
+        return methodNonNull(test);
+    }
+
+    @ParametersAreNonnullByDefault
+    private String methodNonNull(final String test) {
+        return test;
+    }
+}

spotbugsTestCases/src/java/ghIssues/issue374/PackageLevel.java

@@ -0,0 +1,17 @@
+package ghIssues.issue374;
+
+import javax.annotation.Nullable;
+
+public class PackageLevel {
+    public String method() {
+        return methodNullable(null);
+    }
+
+    private String methodNullable(@Nullable final String test) {
+        return methodNonNull(test);
+    }
+
+    private String methodNonNull(final String test) {
+        return test;
+    }
+}

spotbugsTestCases/src/java/ghIssues/issue374/package-info.java

@@ -0,0 +1,5 @@
+/*
+ * An example to reproduce problem at https://github.com/spotbugs/spotbugs/issues/374
+ */
+@javax.annotation.ParametersAreNonnullByDefault
+package ghIssues.issue374;