SONARJAVA-5573 Properly distinguish type parameter annotations from annotations that are applied on the symbol.

- Ensure that the SymbolMetadata.annotation() interface returns exactly the same content

- Create a new SymbolMetadata.symbolAnnotation() to filter out type parameter annotations. This is used by the nullability computation.

Author: GabrielFleischer

java-checks-test-sources/default/src/main/java/annotations/nullability/no_default/NullabilityOfParametrizedTypes.java

@@ -0,0 +1,33 @@
+package annotations.nullability.no_default;
+
+
+import java.util.List;
+import java.util.Map;
+import org.jspecify.annotations.NonNull;
+import org.jspecify.annotations.Nullable;
+
+/**
+ * This check ensures that type parameters and nested annotations are properly handled by JSymbolMetadata
+ */
+public class NullabilityOfParametrizedTypes {
+
+  public Map<Object, Object> id1000_type_NO_ANNOTATION_level_PACKAGE;
+  public List<Object> id1001_type_NO_ANNOTATION_level_PACKAGE;
+
+  public Map<Object, @Nullable Object> id1002_type_NO_ANNOTATION_level_PACKAGE;
+  public List<@Nullable Object> id1003_type_NO_ANNOTATION_level_PACKAGE;
+
+  public Map<Object, @NonNull Object> id1004_type_NO_ANNOTATION_level_PACKAGE;
+  public List<@NonNull Object> id1005_type_NO_ANNOTATION_level_PACKAGE;
+
+  public Map<Object, @org.eclipse.jdt.annotation.Nullable Object> id1006_type_NO_ANNOTATION_level_PACKAGE;
+  public List<@org.eclipse.jdt.annotation.Nullable Object> id1007_type_NO_ANNOTATION_level_PACKAGE;
+
+  public Map.@Nullable Entry<@NonNull Object, @NonNull Object> id1008_type_STRONG_NULLABLE_level_VARIABLE;
+
+  public List<@Nullable Object> id1009_type_NO_ANNOTATION_level_PACKAGE(
+    Map<Object, @NonNull Object> id10010_type_NO_ANNOTATION_level_PACKAGE
+  ) {
+    return List.of();
+  }
+}

java-frontend/src/main/java/org/sonar/java/model/JSymbol.java

@@ -383,29 +383,41 @@ private SymbolMetadata convertMetadata() {
         return new JSymbolMetadata(sema, this, sema.resolvePackageAnnotations(binding.getName()));
       case IBinding.VARIABLE:
         ITypeBinding type = ((IVariableBinding) binding).getType();
-        return new JSymbolMetadata(
-          sema,
-          this,
-          type == null ? new IAnnotationBinding[0] : getAnnotations(type),
-          binding.getAnnotations());
+        if (type == null) {
+          return new JSymbolMetadata(sema, this, binding.getAnnotations());
+        }
+        return convertMetadata(type);
       case IBinding.METHOD:
         ITypeBinding returnType = ((IMethodBinding) binding).getReturnType();
         // In rare circumstances, when the semantic information is incomplete, returnType can be null.
         if (returnType == null) {
           return Symbols.EMPTY_METADATA;
         }
-        return new JSymbolMetadata(sema, this, getAnnotations(returnType), binding.getAnnotations());
+        return convertMetadata(returnType);
       default:
         return new JSymbolMetadata(sema, this, binding.getAnnotations());
     }
   }
 
-  private static IAnnotationBinding[] getAnnotations(ITypeBinding type) {
+  private SymbolMetadata convertMetadata(ITypeBinding type) {
+    var symbolAnnotations = new IAnnotationBinding[binding.getAnnotations().length + type.getTypeAnnotations().length];
+    System.arraycopy(binding.getAnnotations(), 0, symbolAnnotations, 0, binding.getAnnotations().length);
+    System.arraycopy(type.getTypeAnnotations(), 0, symbolAnnotations, binding.getAnnotations().length, type.getTypeAnnotations().length);
+
+    var parameterAnnotations = getParamAnnotations(type);
+
+    return new JSymbolMetadata(
+      sema,
+      this,
+      symbolAnnotations, parameterAnnotations
+    );
+  }
+
+  private static IAnnotationBinding[] getParamAnnotations(ITypeBinding type) {
     List<IAnnotationBinding> iAnnotationBindings = new ArrayList<>();
     for (ITypeBinding typeArgument : type.getTypeArguments()) {
       Collections.addAll(iAnnotationBindings, typeArgument.getTypeAnnotations());
     }
-    Collections.addAll(iAnnotationBindings, type.getTypeAnnotations());
     return iAnnotationBindings.toArray(new IAnnotationBinding[0]);
   }
 

java-frontend/src/main/java/org/sonar/java/model/JSymbolMetadata.java

@@ -48,26 +48,34 @@ final class JSymbolMetadata implements SymbolMetadata {
   private final JSema sema;
   private final Symbol symbol;
   private final IAnnotationBinding[] annotationBindings;
+  private final IAnnotationBinding[] symbolAnnotation;
 
   /**
    * Cache for {@link #annotations()}.
    */
   private List<AnnotationInstance> annotations;
 
+  /**
+   * Cache for {@link #symbolAnnotations()}.
+   */
+  private List<AnnotationInstance> symbolAnnotations;
+
   private final Map<NullabilityTarget, NullabilityData> nullabilityCache = new EnumMap<>(NullabilityTarget.class);
 
   JSymbolMetadata(JSema sema, Symbol symbol, IAnnotationBinding[] annotationBindings) {
     this.sema = Objects.requireNonNull(sema);
     this.symbol = symbol;
+    this.symbolAnnotation = annotationBindings;
     this.annotationBindings = annotationBindings;
   }
 
-  JSymbolMetadata(JSema sema, Symbol symbol, IAnnotationBinding[] typeAnnotationBindings, IAnnotationBinding[] annotationBindings) {
+  JSymbolMetadata(JSema sema, Symbol symbol, IAnnotationBinding[] symbolAnnotation, IAnnotationBinding[] paramAnnotations) {
     this.sema = Objects.requireNonNull(sema);
     this.symbol = symbol;
-    this.annotationBindings = new IAnnotationBinding[typeAnnotationBindings.length + annotationBindings.length];
-    System.arraycopy(typeAnnotationBindings, 0, this.annotationBindings, 0, typeAnnotationBindings.length);
-    System.arraycopy(annotationBindings, 0, this.annotationBindings, typeAnnotationBindings.length, annotationBindings.length);
+    this.symbolAnnotation = symbolAnnotation;
+    this.annotationBindings = new IAnnotationBinding[symbolAnnotation.length + paramAnnotations.length];
+    System.arraycopy(symbolAnnotation, 0, this.annotationBindings, 0, symbolAnnotation.length);
+    System.arraycopy(paramAnnotations, 0, this.annotationBindings, symbolAnnotation.length, paramAnnotations.length);
   }
 
   private static NullabilityData[] forEachLevel(Function<NullabilityLevel, NullabilityData> initializer) {
@@ -92,6 +100,16 @@ public List<AnnotationInstance> annotations() {
     return annotations;
   }
 
+  @Override
+  public List<AnnotationInstance> symbolAnnotations() {
+    if (symbolAnnotations == null) {
+      symbolAnnotations = Arrays.stream(symbolAnnotation)
+        .map(sema::annotation)
+        .collect(Collectors.toList());
+    }
+    return symbolAnnotations;
+  }
+
   @Override
   public final boolean isAnnotatedWith(String fullyQualifiedName) {
     for (AnnotationInstance a : annotations()) {

java-frontend/src/main/java/org/sonar/java/model/JSymbolMetadataNullabilityHelper.java

@@ -317,7 +317,7 @@ private static NullabilityData getNullabilityData(SymbolMetadata metadata,
     TypesForAnnotations typeForAnnotations) {
     NullabilityType nullabilityType = NullabilityType.NO_ANNOTATION;
     AnnotationInstance annotationInstance = null;
-    for (AnnotationInstance annotation : metadata.annotations()) {
+    for (AnnotationInstance annotation : metadata.symbolAnnotations()) {
       NullabilityType typeFromAnnotation = typeForAnnotations.getTypeFromAnnotation(annotation);
       if (typeFromAnnotation.ordinal() > nullabilityType.ordinal()) {
         nullabilityType = typeFromAnnotation;

java-frontend/src/main/java/org/sonar/java/model/JVariableSymbol.java

@@ -98,8 +98,7 @@ static class ParameterPlaceholderSymbol extends Symbols.DefaultSymbol implements
       metadata = new JSymbolMetadata(
         sema,
         this,
-        typeBinding.getTypeAnnotations(),
-        owner.getParameterAnnotations(index)
+        owner.getParameterAnnotations(index), typeBinding.getTypeAnnotations()
       );
     }
 

java-frontend/src/main/java/org/sonar/java/model/Symbols.java

@@ -59,6 +59,11 @@ public List<AnnotationInstance> annotations() {
       return Collections.emptyList();
     }
 
+    @Override
+    public List<AnnotationInstance> symbolAnnotations() {
+      return Collections.emptyList();
+    }
+
     @Override
     public NullabilityData nullabilityData() {
       return JSymbolMetadata.unknownNullabilityAt(NullabilityLevel.UNKNOWN);

java-frontend/src/main/java/org/sonar/plugins/java/api/semantic/SymbolMetadata.java

@@ -44,11 +44,17 @@ public interface SymbolMetadata {
   List<AnnotationValue> valuesForAnnotation(String fullyQualifiedNameOfAnnotation);
 
   /**
-   * The list of annotations found on this symbol.
+   * The list of all annotations found on this symbol, including annotations that are present on the parametrized types.
    * @return A list of {@link AnnotationInstance}
    */
   List<AnnotationInstance> annotations();
 
+  /**
+   * The list of annotations that applies exactly on this symbol.
+   * @return A list of {@link AnnotationInstance}
+   */
+  List<AnnotationInstance> symbolAnnotations();
+
   /**
    * @return the nullability definition for metadata() of:
    * - fields

java-frontend/src/test/java/org/sonar/java/model/JSymbolMetadataTest.java

@@ -185,6 +185,13 @@ void variable_level_nullability() throws IOException {
     );
   }
 
+  @Test
+  void parametrized_type_level_nullability() throws IOException {
+    assertNullability(
+      NULLABILITY_SOURCE_DIR.resolve(Paths.get("no_default", "NullabilityOfParametrizedTypes.java"))
+    );
+  }
+
   @Test
   void unsupported_nullability() throws IOException {
     assertNullability(