Add Guava 31+ support by treating @ParametricNullness as @nullable (#629

)

Guava versions from 31.0 onwards do away with annotating methods as
returning or taking `@Nullable` if nullability depends on the type
parameter. Instead adopting JSpecify semantics for precise handling
of type parameters.

For compatibility (with Kotlin, among other tools), Guava still marks
such returns and arguments specially as `@ParametricNullness`.
    
While imprecise, we can handle Guava as annotated code to at least the
same level as we did previously, by treating `@ParametricNullness` as
an alias for `@Nullable`, until we have full type parameter / generics
support within NullAway.
    
To test this change without bumping our own Guava dependency, we
introduce a new test target: `:guava-recent-unit-tests`.
    
Additionally, since there are actually multiple instances of
`@ParametricNullness` in Guava (one per subpackage), we hard-code
a check for `com.google.common.*.ParametricNullness` in our core
`isNullableAnnotation(...)` check.

An alternative would be to extend `-XepOpt:NullAway:CustomNullableAnnotations`
to allow simple names or regular expressions, but that would make
the mechanism more costly in common case.

See also: #628, google/guava#6126

code-coverage-report/build.gradle

@@ -91,5 +91,6 @@ dependencies {
     implementation project(':nullaway')
     implementation project(':jar-infer:jar-infer-lib')
     implementation project(':jar-infer:nullaway-integration-test')
+    implementation project(':guava-recent-unit-tests')
     implementation project(':jdk17-unit-tests')
 }

guava-recent-unit-tests/build.gradle

@@ -0,0 +1,55 @@
+/*
+ * Copyright (C) 2022. Uber Technologies
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *    http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+plugins {
+    id 'java-library'
+    id 'nullaway.jacoco-conventions'
+}
+
+// We need this separate build target to test newer versions of Guava
+// (e.g. 31+) than that which NullAway currently depends on.
+
+dependencies {
+    testImplementation project(":nullaway")
+    testImplementation deps.test.junit4
+    testImplementation(deps.build.errorProneTestHelpers) {
+        exclude group: "junit", module: "junit"
+    }
+    testImplementation deps.build.jsr305Annotations
+    testImplementation "com.google.guava:guava:31.1-jre"
+}
+
+test {
+    maxHeapSize = "1024m"
+    if (!JavaVersion.current().java9Compatible) {
+        jvmArgs "-Xbootclasspath/p:${configurations.errorproneJavac.asPath}"
+    } else {
+        // to expose necessary JDK types on JDK 16+; see https://errorprone.info/docs/installation#java-9-and-newer
+        jvmArgs += [
+                "--add-exports=jdk.compiler/com.sun.tools.javac.api=ALL-UNNAMED",
+                "--add-exports=jdk.compiler/com.sun.tools.javac.file=ALL-UNNAMED",
+                "--add-exports=jdk.compiler/com.sun.tools.javac.main=ALL-UNNAMED",
+                "--add-exports=jdk.compiler/com.sun.tools.javac.model=ALL-UNNAMED",
+                "--add-exports=jdk.compiler/com.sun.tools.javac.parser=ALL-UNNAMED",
+                "--add-exports=jdk.compiler/com.sun.tools.javac.processing=ALL-UNNAMED",
+                "--add-exports=jdk.compiler/com.sun.tools.javac.tree=ALL-UNNAMED",
+                "--add-exports=jdk.compiler/com.sun.tools.javac.util=ALL-UNNAMED",
+                "--add-opens=jdk.compiler/com.sun.tools.javac.code=ALL-UNNAMED",
+                "--add-opens=jdk.compiler/com.sun.tools.javac.comp=ALL-UNNAMED",
+                // Accessed by Lombok tests
+                "--add-opens=jdk.compiler/com.sun.tools.javac.jvm=ALL-UNNAMED",
+        ]
+    }
+}

guava-recent-unit-tests/src/test/java/com/uber/nullaway/guava/NullAwayGuavaParametricNullnessTests.java

@@ -0,0 +1,92 @@
+/*
+ * Copyright (c) 2022 Uber Technologies, Inc.
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ */
+
+import com.google.errorprone.CompilationTestHelper;
+import com.uber.nullaway.NullAway;
+import java.util.Arrays;
+import org.junit.Before;
+import org.junit.Rule;
+import org.junit.Test;
+import org.junit.rules.TemporaryFolder;
+
+public class NullAwayGuavaParametricNullnessTests {
+  @Rule public final TemporaryFolder temporaryFolder = new TemporaryFolder();
+
+  private CompilationTestHelper defaultCompilationHelper;
+
+  @Before
+  public void setup() {
+    defaultCompilationHelper =
+        CompilationTestHelper.newInstance(NullAway.class, getClass())
+            .setArgs(
+                Arrays.asList(
+                    "-d",
+                    temporaryFolder.getRoot().getAbsolutePath(),
+                    "-XepOpt:NullAway:AnnotatedPackages=com.uber,com.google.common"));
+  }
+
+  @Test
+  public void testFutureCallbackParametricNullness() {
+    defaultCompilationHelper
+        .addSourceLines(
+            "Test.java",
+            "package com.uber;",
+            "import com.google.common.util.concurrent.FutureCallback;",
+            "import javax.annotation.Nullable;",
+            "class Test {",
+            "    public static <T> FutureCallback<T> wrapFutureCallback(FutureCallback<T> futureCallback) {",
+            "        return new FutureCallback<T>() {",
+            "            @Override",
+            "            public void onSuccess(@Nullable T result) {",
+            "                futureCallback.onSuccess(result);",
+            "            }",
+            "            @Override",
+            "            public void onFailure(Throwable throwable) {",
+            "                futureCallback.onFailure(throwable);",
+            "            }",
+            "        };",
+            "    }",
+            "}")
+        .doTest();
+  }
+
+  @Test
+  public void testIterableParametricNullness() {
+    defaultCompilationHelper
+        .addSourceLines(
+            "Test.java",
+            "package com.uber;",
+            "import com.google.common.collect.ImmutableList;",
+            "import com.google.common.collect.Iterables;",
+            "import javax.annotation.Nullable;",
+            "class Test {",
+            "    public static String test1() {",
+            "        // BUG: Diagnostic contains: returning @Nullable expression",
+            "        return Iterables.getFirst(ImmutableList.<String>of(), null);",
+            "    }",
+            "    public static @Nullable String test2() {",
+            "        return Iterables.getFirst(ImmutableList.<String>of(), null);",
+            "    }",
+            "}")
+        .doTest();
+  }
+}

nullaway/src/main/java/com/uber/nullaway/Nullness.java

@@ -156,6 +156,12 @@ public static boolean isNullableAnnotation(String annotName, Config config) {
         || annotName.endsWith(".checkerframework.checker.nullness.compatqual.NullableDecl")
         // matches javax.annotation.CheckForNull and edu.umd.cs.findbugs.annotations.CheckForNull
         || annotName.endsWith(".CheckForNull")
+        // matches any of the multiple @ParametricNullness annotations used within Guava
+        // (see https://github.com/google/guava/issues/6126)
+        // We check the simple name first and the package prefix second for boolean short
+        // circuiting, as Guava includes
+        // many annotations
+        || (annotName.endsWith(".ParametricNullness") && annotName.startsWith("com.google.common."))
         || (config.acknowledgeAndroidRecent()
             && annotName.equals("androidx.annotation.RecentlyNullable"))
         || config.isCustomNullableAnnotation(annotName);

settings.gradle

@@ -22,6 +22,7 @@ include ':jar-infer:jar-infer-cli'
 include ':jar-infer:test-java-lib-jarinfer'
 include ':jar-infer:nullaway-integration-test'
 include ':jmh'
+include ':guava-recent-unit-tests'
 include ':jdk17-unit-tests'
 
 // The following modules require JDK 11 and fail during Gradle configuration on JDK 8