Add JarInfer models for Android SDK 31 (Android 12) (#532)

Generated based on AOSP tag android-12.0.0_r21.

This required minor changes to the RELEASING.md process and our
scripts, to account for changes in AOSP's build output structure.

Additionally, this PR includes a minor fix for the JarInfer
driver, which moves return-value inference code to the same
try-catch block for Wala IR generation errors as the parameter
nullability inference code, as well as a small refactoring  and
clarification of the parameter nullability inference code.

RELEASING.md

@@ -5,7 +5,7 @@
  2. Get a copy of the AOSP `framework_intermediates` for the corresponding Android version.
     2a. At Uber? http://t.uber.com/aosp_framework_intermediate
     2b. Elsewhere? You can still build the corresponding AOSP version and look for
-        out/target/common/obj/JAVA_LIBRARIES/framework_intermediates/**
+        out/target/common/obj/JAVA_LIBRARIES/**
  3. (first time) `cp jar-infer/scripts/android-jar.conf.template jar-infer/scripts/android-jar.conf`
  4. Set the correct paths and versions in `android-jar.conf`
  5. `rm jar-infer/android-jarinfer-models-sdk28/src/main/resources/jarinfer.astubx` (for SDK 28)

jar-infer/android-jarinfer-models-sdk31/build.gradle

@@ -0,0 +1,14 @@
+plugins {
+    id "java-library"
+}
+
+sourceCompatibility = 1.8
+
+repositories {
+    mavenCentral()
+}
+
+dependencies {
+}
+
+apply plugin: 'com.vanniktech.maven.publish'

jar-infer/android-jarinfer-models-sdk31/gradle.properties

@@ -0,0 +1,19 @@
+#
+# Copyright (C) 2021. 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.
+#
+
+POM_NAME=JarInferAndroidModelsSDK31
+POM_ARTIFACT_ID=android-jarinfer-models-sdk31
+POM_PACKAGING=jar

jar-infer/jar-infer-lib/src/main/java/com/uber/nullaway/jarinfer/DefinitelyDerefedParamsDriver.java

@@ -33,6 +33,7 @@
 import com.ibm.wala.ipa.cha.ClassHierarchyException;
 import com.ibm.wala.ipa.cha.ClassHierarchyFactory;
 import com.ibm.wala.ipa.cha.IClassHierarchy;
+import com.ibm.wala.shrikeCT.InvalidClassFileException;
 import com.ibm.wala.ssa.IR;
 import com.ibm.wala.ssa.ISSABasicBlock;
 import com.ibm.wala.ssa.SSAInstruction;
@@ -206,6 +207,14 @@ public MethodParamAnnotations run(
     return nonnullParams;
   }
 
+  // Check if a method includes any dereferences at all at the bytecode level
+  private boolean bytecodeHasAnyDereferences(IMethod mtd) throws InvalidClassFileException {
+    // A dereference is either a field access (o.f) or a method call (o.m())
+    return !CodeScanner.getFieldsRead(mtd).isEmpty()
+        || !CodeScanner.getFieldsWritten(mtd).isEmpty()
+        || !CodeScanner.getCallSites(mtd).isEmpty();
+  }
+
   private void analyzeFile(String pkgName, String inPath, boolean includeNonPublicClasses)
       throws IOException, ClassHierarchyException {
     InputStream jarIS = null;
@@ -246,13 +255,16 @@ private void analyzeFile(String pkgName, String inPath, boolean includeNonPublic
               Preconditions.checkNotNull(mtd, "method not found");
               DefinitelyDerefedParams analysisDriver = null;
               String sign = "";
-              // Parameter analysis
-              if (mtd.getNumberOfParameters() > (mtd.isStatic() ? 0 : 1)) {
-                // Skip methods by looking at bytecode
-                try {
-                  if (!CodeScanner.getFieldsRead(mtd).isEmpty()
-                      || !CodeScanner.getFieldsWritten(mtd).isEmpty()
-                      || !CodeScanner.getCallSites(mtd).isEmpty()) {
+              try {
+                // Parameter analysis
+                if (mtd.getNumberOfParameters() > (mtd.isStatic() ? 0 : 1)) {
+                  // For inferring parameter nullability, our criteria is based on finding
+                  // unchecked dereferences of that parameter. We perform a quick bytecode
+                  // check and skip methods containing no dereferences (i.e. method calls
+                  // or field accesses) at all, avoiding the expensive IR/CFG generation
+                  // step for these methods.
+                  // Note that this doesn't apply to inferring return value nullability.
+                  if (bytecodeHasAnyDereferences(mtd)) {
                     analysisDriver = getAnalysisDriver(mtd, options, cache);
                     Set<Integer> result = analysisDriver.analyze();
                     sign = getSignature(mtd);
@@ -265,14 +277,15 @@ private void analyzeFile(String pkgName, String inPath, boolean includeNonPublic
                           "Inferred Nonnull param for method: " + sign + " = " + result.toString());
                     }
                   }
-                } catch (Exception e) {
-                  LOG(
-                      DEBUG,
-                      "DEBUG",
-                      "Exception while scanning bytecodes for " + mtd + " " + e.getMessage());
                 }
+                // Return value analysis
+                analyzeReturnValue(options, cache, mtd, analysisDriver, sign);
+              } catch (Exception e) {
+                LOG(
+                    DEBUG,
+                    "DEBUG",
+                    "Exception while scanning bytecodes for " + mtd + " " + e.getMessage());
               }
-              analyzeReturnValue(options, cache, mtd, analysisDriver, sign);
             }
           }
         }

jar-infer/scripts/android-jar.py

@@ -20,7 +20,9 @@
 
 ### Finding android libraries ###
 print "> Finding android libraries..."
-cmd = "find " + ajars_dir + " -name \"*.jar\""
+# Since SDK 31, the directory structure mixes classes.jar and classes-header.jar files, we use
+# only the former, as classes-header.jar files are missing methods' bytecode.
+cmd = "find " + ajars_dir + " -name \"*.jar\" | grep -v classes-header.jar"
 ajars = subprocess.Popen(cmd, stdout=subprocess.PIPE, shell=True).stdout.read().splitlines()
 for ajar in ajars:
   cmd = "jar tvf " + ajar + " | grep \"\.class$\" | awk '{print $8}'"

settings.gradle

@@ -24,6 +24,7 @@ include ':compile-bench'
 include ':jar-infer:android-jarinfer-models-sdk28'
 include ':jar-infer:android-jarinfer-models-sdk29'
 include ':jar-infer:android-jarinfer-models-sdk30'
+include ':jar-infer:android-jarinfer-models-sdk31'
 include ':jar-infer:jar-infer-lib'
 include ':jar-infer:jar-infer-cli'
 include ':jar-infer:test-java-lib-jarinfer'