Generate get-targeted annotations on annotation constructor parameters

This change would also make NotNull annotations to be generated on
non-primitive annotation methods, but we skip this deliberately because
annotation methods never return null on JVM anyway

 #KT-25287 Fixed

compiler/backend/src/org/jetbrains/kotlin/codegen/AnnotationCodegen.java

@@ -29,6 +29,7 @@ import org.jetbrains.kotlin.load.java.JvmAnnotationNames;
 import org.jetbrains.kotlin.name.FqName;
 import org.jetbrains.kotlin.name.Name;
 import org.jetbrains.kotlin.resolve.AnnotationChecker;
+import org.jetbrains.kotlin.resolve.DescriptorUtils;
 import org.jetbrains.kotlin.resolve.checkers.ExpectedActualDeclarationChecker;
 import org.jetbrains.kotlin.resolve.constants.*;
 import org.jetbrains.kotlin.resolve.descriptorUtil.DescriptorUtilsKt;
@@ -166,10 +167,17 @@ public abstract class AnnotationCodegen {
             if (isInvisibleFromTheOutside(descriptor)) return;
             if (descriptor instanceof ValueParameterDescriptor && isInvisibleFromTheOutside(descriptor.getContainingDeclaration())) return;
 
+            // No need to annotate annotation methods since they're always non-null
+            if (descriptor instanceof PropertyGetterDescriptor &&
+                DescriptorUtils.isAnnotationClass(descriptor.getContainingDeclaration())) {
+                return;
+            }
+
             if (returnType != null && !AsmUtil.isPrimitive(returnType)) {
                 generateNullabilityAnnotation(descriptor.getReturnType(), annotationDescriptorsAlreadyPresent);
             }
         }
+
         if (unwrapped instanceof ClassDescriptor) {
             ClassDescriptor classDescriptor = (ClassDescriptor) unwrapped;
             if (classDescriptor.getKind() == ClassKind.ANNOTATION_CLASS) {

compiler/backend/src/org/jetbrains/kotlin/codegen/FunctionCodegen.java

@@ -232,7 +232,7 @@ public class FunctionCodegen {
             v.getSerializationBindings().put(METHOD_FOR_FUNCTION, CodegenUtilKt.unwrapFrontendVersion(functionDescriptor), asmMethod);
         }
 
-        generateMethodAnnotations(functionDescriptor, asmMethod, mv);
+        generateMethodAnnotations(functionDescriptor, asmMethod, mv, memberCodegen, typeMapper);
 
         generateParameterAnnotations(functionDescriptor, mv, jvmSignature);
         GenerateJava8ParameterNamesKt.generateParameterNames(functionDescriptor, mv, jvmSignature, state, (flags & ACC_SYNTHETIC) != 0);
@@ -474,14 +474,6 @@ public class FunctionCodegen {
         );
     }
 
-    private void generateMethodAnnotations(
-            @NotNull FunctionDescriptor functionDescriptor,
-            Method asmMethod,
-            MethodVisitor mv
-    ) {
-        generateMethodAnnotations(functionDescriptor, asmMethod, mv, memberCodegen, typeMapper);
-    }
-
     public static void generateMethodAnnotations(
             @NotNull FunctionDescriptor functionDescriptor,
             Method asmMethod,

compiler/backend/src/org/jetbrains/kotlin/codegen/PropertyCodegen.java

@@ -266,15 +266,20 @@ public class PropertyCodegen {
             @Nullable FunctionDescriptor expectedAnnotationConstructor
     ) {
         JvmMethodGenericSignature signature = typeMapper.mapAnnotationParameterSignature(descriptor);
-        String name = parameter.getName();
+        Method asmMethod = signature.getAsmMethod();
-        if (name == null) return;
         MethodVisitor mv = v.newMethod(
-                JvmDeclarationOriginKt.OtherOrigin(parameter, descriptor), ACC_PUBLIC | ACC_ABSTRACT, name,
+                JvmDeclarationOriginKt.OtherOrigin(parameter, descriptor),
-                signature.getAsmMethod().getDescriptor(),
+                ACC_PUBLIC | ACC_ABSTRACT,
+                asmMethod.getName(),
+                asmMethod.getDescriptor(),
                 signature.getGenericsSignature(),
                 null
         );
 
+        PropertyGetterDescriptor getter = descriptor.getGetter();
+        assert getter != null : "Annotation property should have a getter: " + descriptor;
+        FunctionCodegen.generateMethodAnnotations(getter, asmMethod, mv, memberCodegen, typeMapper);
+
         KtExpression defaultValue = loadAnnotationArgumentDefaultValue(parameter, descriptor, expectedAnnotationConstructor);
         if (defaultValue != null) {
             ConstantValue<?> constant = ExpressionCodegen.getCompileTimeConstant(

compiler/testData/codegen/box/annotations/annotatedAnnotationParameter.kt

@@ -0,0 +1,18 @@
+// TARGET_BACKEND: JVM
+// WITH_RUNTIME
+
+import kotlin.test.assertEquals
+
+annotation class Name(val value: String)
+
+annotation class Anno(
+    @get:Name("O") val o: String,
+    @get:Name("K") val k: String
+)
+
+fun box(): String {
+    val ms = Anno::class.java.declaredMethods
+
+    return (ms.single { it.name == "o" }.annotations.single() as Name).value +
+           (ms.single { it.name == "k" }.annotations.single() as Name).value
+}

compiler/tests/org/jetbrains/kotlin/codegen/BlackBoxCodegenTestGenerated.java

@@ -41,6 +41,11 @@ public class BlackBoxCodegenTestGenerated extends AbstractBlackBoxCodegenTest {
             KotlinTestUtils.assertAllTestsPresentByMetadata(this.getClass(), new File("compiler/testData/codegen/box/annotations"), Pattern.compile("^(.+)\\.kt$"), TargetBackend.JVM, true);
         }
 
+        @TestMetadata("annotatedAnnotationParameter.kt")
+        public void testAnnotatedAnnotationParameter() throws Exception {
+            runTest("compiler/testData/codegen/box/annotations/annotatedAnnotationParameter.kt");
+        }
+
         @TestMetadata("annotatedEnumEntry.kt")
         public void testAnnotatedEnumEntry() throws Exception {
             runTest("compiler/testData/codegen/box/annotations/annotatedEnumEntry.kt");

compiler/tests/org/jetbrains/kotlin/codegen/LightAnalysisModeTestGenerated.java

@@ -46,6 +46,11 @@ public class LightAnalysisModeTestGenerated extends AbstractLightAnalysisModeTes
             KotlinTestUtils.assertAllTestsPresentByMetadata(this.getClass(), new File("compiler/testData/codegen/box/annotations"), Pattern.compile("^(.+)\\.kt$"), TargetBackend.JVM, true);
         }
 
+        @TestMetadata("annotatedAnnotationParameter.kt")
+        public void testAnnotatedAnnotationParameter() throws Exception {
+            runTest("compiler/testData/codegen/box/annotations/annotatedAnnotationParameter.kt");
+        }
+
         @TestMetadata("annotatedEnumEntry.kt")
         public void testAnnotatedEnumEntry() throws Exception {
             runTest("compiler/testData/codegen/box/annotations/annotatedEnumEntry.kt");

compiler/tests/org/jetbrains/kotlin/codegen/ir/IrBlackBoxCodegenTestGenerated.java

@@ -41,6 +41,11 @@ public class IrBlackBoxCodegenTestGenerated extends AbstractIrBlackBoxCodegenTes
             KotlinTestUtils.assertAllTestsPresentByMetadata(this.getClass(), new File("compiler/testData/codegen/box/annotations"), Pattern.compile("^(.+)\\.kt$"), TargetBackend.JVM_IR, true);
         }
 
+        @TestMetadata("annotatedAnnotationParameter.kt")
+        public void testAnnotatedAnnotationParameter() throws Exception {
+            runTest("compiler/testData/codegen/box/annotations/annotatedAnnotationParameter.kt");
+        }
+
         @TestMetadata("annotatedEnumEntry.kt")
         public void testAnnotatedEnumEntry() throws Exception {
             runTest("compiler/testData/codegen/box/annotations/annotatedEnumEntry.kt");