Don't report errors for writes to @NullUnmarked fields (#1102)

Fixes #1101
uber · Dec 19, 2024 · b7dad0c · b7dad0c
1 parent 41c7c55
commit b7dad0c
Show file tree

Hide file tree

Showing 3 changed files with 50 additions and 1 deletion.
diff --git a/nullaway/src/main/java/com/uber/nullaway/NullAway.java b/nullaway/src/main/java/com/uber/nullaway/NullAway.java
@@ -485,6 +485,11 @@ public Description matchAssignment(AssignmentTree tree, VisitorState state) {
     if (lhsType != null && lhsType.isPrimitive()) {
       doUnboxingCheck(state, tree.getExpression());
     }
+    Symbol assigned = ASTHelpers.getSymbol(tree.getVariable());
+    if (assigned != null && codeAnnotationInfo.isSymbolUnannotated(assigned, config, handler)) {
+      // assigning to symbol that is unannotated
+      return Description.NO_MATCH;
+    }
     // generics check
     if (lhsType != null && config.isJSpecifyMode()) {
       GenericsChecks.checkTypeParameterNullnessForAssignability(tree, this, state);
@@ -508,7 +513,6 @@ public Description matchAssignment(AssignmentTree tree, VisitorState state) {
       }
     }
 
-    Symbol assigned = ASTHelpers.getSymbol(tree.getVariable());
     if (assigned == null || assigned.getKind() != ElementKind.FIELD) {
       // not a field of nullable type
       return Description.NO_MATCH;

diff --git a/nullaway/src/test/java/com/uber/nullaway/jspecify/GenericsTests.java b/nullaway/src/test/java/com/uber/nullaway/jspecify/GenericsTests.java
@@ -2045,6 +2045,30 @@ public void issue1093() {
         .doTest();
   }
 
+  @Test
+  public void nullUnmarkedGenericField() {
+    makeHelper()
+        .addSourceLines(
+            "Test.java",
+            "package com.unannotated;",
+            "import org.jspecify.annotations.*;",
+            "import java.util.function.Function;",
+            "public class Test {",
+            "  static Function<@Nullable String, @Nullable String> foo;",
+            "  @NullMarked",
+            "  static class Inner {",
+            "    static @Nullable Function<@Nullable String, @Nullable String> bar;",
+            "    void bar(Function<String,String> f) {",
+            "      // no error since foo is in @NullUnmarked code",
+            "      foo = f;",
+            "      // BUG: Diagnostic contains: Cannot assign from type Function<String, String>",
+            "      bar = f;",
+            "    }",
+            "  }",
+            "}")
+        .doTest();
+  }
+
   private CompilationTestHelper makeHelper() {
     return makeTestHelperWithArgs(
         Arrays.asList(

diff --git a/nullaway/src/test/java/com/uber/nullaway/jspecify/NullMarkednessTests.java b/nullaway/src/test/java/com/uber/nullaway/jspecify/NullMarkednessTests.java
@@ -1173,4 +1173,25 @@ public void nullUnmarkedOnConstructorSuppressesInitializerWarnings() {
             "}")
         .doTest();
   }
+
+  @Test
+  public void writeToNullUnmarkedField() {
+    defaultCompilationHelper
+        .addSourceLines(
+            "Test.java",
+            "package com.unannotated;",
+            "import org.jspecify.annotations.NullMarked;",
+            "public class Test {",
+            "    static Object foo;",
+            "    @NullMarked",
+            "    static class Inner {",
+            "        String bar() {",
+            "            // expecting no errors since foo is in @NullUnmarked code",
+            "            foo = null;",
+            "            return foo.toString();",
+            "        }",
+            "    }",
+            "}")
+        .doTest();
+  }
 }