Avoid descriptors usage in IrFunction flag calculation

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

@@ -258,13 +258,18 @@ public class AsmUtil {
             return specialCase;
         }
         Visibility visibility = descriptor.getVisibility();
-        Integer defaultMapping = visibilityToAccessFlag.get(visibility);
+        Integer defaultMapping = getVisibilityAccessFlag(visibility);
         if (defaultMapping == null) {
             throw new IllegalStateException(visibility + " is not a valid visibility in backend for " + DescriptorRenderer.DEBUG_TEXT.render(descriptor));
         }
         return defaultMapping;
     }
 
+    @Nullable
+    public static Integer getVisibilityAccessFlag(Visibility visibility) {
+        return visibilityToAccessFlag.get(visibility);
+    }
+
     /*
         Use this method to get visibility flag for class to define it in byte code (v.defineClass method).
         For other cases use getVisibilityAccessFlag(MemberDescriptor descriptor)

compiler/ir/backend.common/src/org/jetbrains/kotlin/ir/util/IrUtils.kt

@@ -27,9 +27,11 @@ import org.jetbrains.kotlin.ir.declarations.impl.IrTypeParameterImpl
 import org.jetbrains.kotlin.ir.declarations.impl.IrValueParameterImpl
 import org.jetbrains.kotlin.ir.expressions.*
 import org.jetbrains.kotlin.ir.symbols.*
+import org.jetbrains.kotlin.name.FqName
 import org.jetbrains.kotlin.name.Name
 import org.jetbrains.kotlin.psi.psiUtil.endOffset
 import org.jetbrains.kotlin.psi.psiUtil.startOffset
+import org.jetbrains.kotlin.resolve.descriptorUtil.fqNameSafe
 import org.jetbrains.kotlin.resolve.source.PsiSourceElement
 import org.jetbrains.kotlin.types.KotlinType
 
@@ -276,4 +278,11 @@ val IrClass.isEnumClass get() = kind == ClassKind.ENUM_CLASS
 val IrClass.isEnumEntry get() = kind == ClassKind.ENUM_ENTRY
 val IrClass.isInterface get() = kind == ClassKind.INTERFACE
 val IrClass.isClass get() = kind == ClassKind.CLASS
-val IrClass.isObject get() = kind == ClassKind.OBJECT
+val IrClass.isObject get() = kind == ClassKind.OBJECT
+
+val IrDeclaration.parentAsClass get() = parent as IrClass
+
+fun IrAnnotationContainer.hasAnnotation(name: FqName) =
+    annotations.any {
+        it.symbol.owner.parentAsClass.descriptor.fqNameSafe == name
+    }

compiler/ir/backend.jvm/src/org/jetbrains/kotlin/backend/jvm/codegen/FunctionCodegen.kt

@@ -18,13 +18,14 @@ package org.jetbrains.kotlin.backend.jvm.codegen
 
 import org.jetbrains.kotlin.backend.common.lower.DECLARATION_ORIGIN_FUNCTION_FOR_DEFAULT_PARAMETER
 import org.jetbrains.kotlin.backend.jvm.descriptors.JvmDescriptorWithExtraFlags
-import org.jetbrains.kotlin.backend.common.lower.InitializersLowering
 import org.jetbrains.kotlin.codegen.*
 import org.jetbrains.kotlin.codegen.FunctionCodegen
 import org.jetbrains.kotlin.codegen.state.GenerationState
+import org.jetbrains.kotlin.descriptors.Modality
 import org.jetbrains.kotlin.ir.declarations.IrClass
 import org.jetbrains.kotlin.ir.declarations.IrConstructor
 import org.jetbrains.kotlin.ir.declarations.IrFunction
+import org.jetbrains.kotlin.ir.declarations.IrSimpleFunction
 import org.jetbrains.kotlin.ir.util.dump
 import org.jetbrains.kotlin.ir.util.isAnnotationClass
 import org.jetbrains.kotlin.psi.KtParameter
@@ -77,15 +78,26 @@ open class FunctionCodegen(private val irFunction: IrFunction, private val class
             }
         }
 
-        var flags = AsmUtil.getMethodAsmFlags(descriptor, OwnerKind.IMPLEMENTATION, state).or(if (isStatic) Opcodes.ACC_STATIC else 0).xor(
-            if (classCodegen.irClass.isAnnotationClass) Opcodes.ACC_FINAL else 0/*TODO*/
-        ).or(if (descriptor is JvmDescriptorWithExtraFlags) descriptor.extraFlags else 0)
-
-        if (classCodegen.irClass.isJvmInterface && InitializersLowering.clinitName == irFunction.name) {
-            //reset abstract flag for <clinit>
-            flags = flags.xor(Opcodes.ACC_ABSTRACT)
+        val visibility = AsmUtil.getVisibilityAccessFlag(irFunction.visibility) ?: error("Unmapped visibility ${irFunction.visibility}")
+        val staticFlag = if (isStatic) Opcodes.ACC_STATIC else 0
+        val varargFlag = if (irFunction.valueParameters.any { it.varargElementType != null }) Opcodes.ACC_VARARGS else 0
+        val deprecation = 0 //TODO
+        val bridgeFlag = 0 //TODO
+        val modalityFlag = when ((irFunction as? IrSimpleFunction)?.modality) {
+            Modality.FINAL -> if (!classCodegen.irClass.isAnnotationClass) Opcodes.ACC_FINAL else 0
+            Modality.ABSTRACT -> Opcodes.ACC_ABSTRACT
+            else -> if (classCodegen.irClass.isJvmInterface) Opcodes.ACC_ABSTRACT else 0 //TODO transform interface modality on lowering to DefaultImpls
         }
-        return flags
+        val nativeFlag = if (irFunction.isExternal) Opcodes.ACC_NATIVE else 0
+
+        return visibility or
+                modalityFlag or
+                staticFlag or
+                varargFlag or
+                deprecation or
+                nativeFlag or
+                bridgeFlag or
+                (if (descriptor is JvmDescriptorWithExtraFlags) descriptor.extraFlags else 0)
     }
 
     protected open fun createMethod(flags: Int, signature: JvmMethodGenericSignature): MethodVisitor {

compiler/ir/backend.jvm/src/org/jetbrains/kotlin/backend/jvm/codegen/irCodegenUtils.kt

@@ -11,14 +11,15 @@ import org.jetbrains.kotlin.ir.declarations.IrConstructor
 import org.jetbrains.kotlin.ir.declarations.IrFunction
 import org.jetbrains.kotlin.ir.declarations.IrSymbolOwner
 import org.jetbrains.kotlin.ir.symbols.IrSymbol
-import org.jetbrains.kotlin.ir.util.isAnnotationClass
-import org.jetbrains.kotlin.ir.util.isInterface
+import org.jetbrains.kotlin.ir.util.*
+import org.jetbrains.kotlin.resolve.annotations.JVM_STATIC_ANNOTATION_FQ_NAME
 import org.jetbrains.org.objectweb.asm.Type
 
 class IrFrameMap : FrameMapBase<IrSymbol>()
 
 internal val IrFunction.isStatic
-    get() = this.dispatchReceiverParameter == null && this !is IrConstructor
+    get() = (this.dispatchReceiverParameter == null && this !is IrConstructor) ||
+            (parentAsClass.isObject && this.hasAnnotation(JVM_STATIC_ANNOTATION_FQ_NAME)) //TODO add lowering
 
 fun IrFrameMap.enter(irDeclaration: IrSymbolOwner, type: Type): Int {
     return enter(irDeclaration.symbol, type)

compiler/ir/backend.jvm/src/org/jetbrains/kotlin/backend/jvm/lower/InterfaceLowering.kt

@@ -69,6 +69,7 @@ class InterfaceLowering(val state: GenerationState) : IrElementTransformerVoid()
                     createDefaultImplFunDescriptor(defaultImplsDescriptor, descriptor, interfaceDescriptor, state.typeMapper)
                 members.add(functionDescriptorImpl.createFunctionAndMapVariables(it, it.visibility))
                 it.body = null
+                //TODO reset modality to abstract
             }
         }