From 3d09158395364662315bd034e0a2939c730e113e Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?L=C3=A1zaro=20Clapp?= <lazaro@uber.com>
Date: Mon, 12 Sep 2022 21:23:38 -0400
Subject: [PATCH] Fix for querying for generated code w/ .class expressions.
 (#655)

Follow up to #654, very similar situation, but on a different `CodeAnnotationInfo` (i.e `isGenerated`).

This version of the issue only shows up under `-XepOpt:NullAway:TreatGeneratedAsUnannotated=true` so it wasn't caught by our earlier test (or our internal Android codebase).
---
 .../com/uber/nullaway/CodeAnnotationInfo.java | 13 ++++-
 .../uber/nullaway/NullAwayJSpecifyTests.java  | 51 ++++++++++++++++++-
 2 files changed, 61 insertions(+), 3 deletions(-)

diff --git a/nullaway/src/main/java/com/uber/nullaway/CodeAnnotationInfo.java b/nullaway/src/main/java/com/uber/nullaway/CodeAnnotationInfo.java
index 849d3e938d..55de1b66a5 100644
--- a/nullaway/src/main/java/com/uber/nullaway/CodeAnnotationInfo.java
+++ b/nullaway/src/main/java/com/uber/nullaway/CodeAnnotationInfo.java
@@ -106,8 +106,17 @@ private static boolean fromAnnotatedPackage(
    *     {@code @Generated}; false otherwise
    */
   public boolean isGenerated(Symbol symbol, Config config) {
-    Symbol.ClassSymbol outermostClassSymbol =
-        get(castToNonNull(ASTHelpers.enclosingClass(symbol)), config).outermostClassSymbol;
+    Symbol.ClassSymbol classSymbol = ASTHelpers.enclosingClass(symbol);
+    if (classSymbol == null) {
+      Preconditions.checkArgument(
+          isClassFieldOfPrimitiveType(
+              symbol), // One known case where this can happen: int.class, void.class, etc.
+          String.format(
+              "Unexpected symbol passed to CodeAnnotationInfo.isGenerated(...) with null enclosing class: %s",
+              symbol));
+      return false;
+    }
+    Symbol.ClassSymbol outermostClassSymbol = get(classSymbol, config).outermostClassSymbol;
     return ASTHelpers.hasDirectAnnotationWithSimpleName(outermostClassSymbol, "Generated");
   }
 
diff --git a/nullaway/src/test/java/com/uber/nullaway/NullAwayJSpecifyTests.java b/nullaway/src/test/java/com/uber/nullaway/NullAwayJSpecifyTests.java
index 166da7262e..0e653b4576 100644
--- a/nullaway/src/test/java/com/uber/nullaway/NullAwayJSpecifyTests.java
+++ b/nullaway/src/test/java/com/uber/nullaway/NullAwayJSpecifyTests.java
@@ -1049,7 +1049,7 @@ public void nullMarkedStaticImports() {
   }
 
   @Test
-  public void dotClassSanityTest() {
+  public void dotClassSanityTest1() {
     // Check that we do not crash while determining the nullmarked-ness of primitive.class (e.g.
     // int.class)
     makeTestHelperWithArgs(
@@ -1064,6 +1064,7 @@ public void dotClassSanityTest() {
             "package com.uber;",
             "import com.example.jspecify.future.annotations.NullMarked;",
             "import org.jspecify.nullness.Nullable;",
+            "import java.lang.reflect.Field;",
             "@NullMarked",
             "public class Test {",
             "  public void takesClass(Class c) {",
@@ -1078,6 +1079,54 @@ public void dotClassSanityTest() {
             "    // NEEDED TO TRIGGER DATAFLOW:",
             "    return flag ? Test.class : new Object();",
             "  }",
+            "  public boolean test2(Field field) {",
+            "    if (field.getType() == int.class || field.getType() == Integer.class) {",
+            "      return true;",
+            "    }",
+            "    return false;",
+            "  }",
+            "}")
+        .doTest();
+  }
+
+  @Test
+  public void dotClassSanityTest2() {
+    // Check that we do not crash while determining the nullmarked-ness of primitive.class (e.g.
+    // int.class)
+    makeTestHelperWithArgs(
+            Arrays.asList(
+                "-d",
+                temporaryFolder.getRoot().getAbsolutePath(),
+                // Flag is required for now, but might no longer be need with @NullMarked!
+                "-XepOpt:NullAway:AnnotatedPackages=com.uber.dontcare",
+                "-XepOpt:NullAway:AcknowledgeRestrictiveAnnotations=true",
+                "-XepOpt:NullAway:TreatGeneratedAsUnannotated=true"))
+        .addSourceLines(
+            "Test.java",
+            "package com.uber;",
+            "import com.example.jspecify.future.annotations.NullMarked;",
+            "import org.jspecify.nullness.Nullable;",
+            "import java.lang.reflect.Field;",
+            "@NullMarked",
+            "public class Test {",
+            "  public void takesClass(Class c) {",
+            "  }",
+            "  public Object test(boolean flag) {",
+            "    takesClass(Test.class);",
+            "    takesClass(String.class);",
+            "    takesClass(int.class);",
+            "    takesClass(boolean.class);",
+            "    takesClass(float.class);",
+            "    takesClass(void.class);",
+            "    // NEEDED TO TRIGGER DATAFLOW:",
+            "    return flag ? Test.class : new Object();",
+            "  }",
+            "  public boolean test2(Field field) {",
+            "    if (field.getType() == int.class || field.getType() == Integer.class) {",
+            "      return true;",
+            "    }",
+            "    return false;",
+            "  }",
             "}")
         .doTest();
   }