Generate synthetic unbox method for each wrapper of inline class

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

@@ -83,6 +83,7 @@ public abstract class ClassBodyCodegen extends MemberCodegen<KtPureClassOrObject
             generateConstructors();
             generateDefaultImplsIfNeeded();
             generateErasedInlineClassIfNeeded();
+            generateUnboxMethodForInlineClass();
         }
 
         // Generate _declared_ companions
@@ -148,6 +149,8 @@ public abstract class ClassBodyCodegen extends MemberCodegen<KtPureClassOrObject
 
     protected void generateErasedInlineClassIfNeeded() {}
 
+    protected void generateUnboxMethodForInlineClass() {}
+
     private static boolean shouldProcessFirst(KtDeclaration declaration) {
         return !(declaration instanceof KtProperty || declaration instanceof KtNamedFunction);
     }

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

@@ -241,7 +241,8 @@ public class FunctionCodegen {
                 isClass(containingDeclaration) &&
                 ((ClassDescriptor) containingDeclaration).isInline() &&
                 contextKind != OwnerKind.ERASED_INLINE_CLASS &&
-                functionDescriptor instanceof SimpleFunctionDescriptor;
+                functionDescriptor instanceof SimpleFunctionDescriptor &&
+                origin.getOriginKind() != JvmDeclarationOriginKind.UNBOX_METHOD_OF_INLINE_CLASS;
 
         if (isOpenSuspendInClass) {
             generateOpenMethodInSuspendClass(

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

@@ -36,10 +36,7 @@ import org.jetbrains.kotlin.name.Name;
 import org.jetbrains.kotlin.platform.JavaToKotlinClassMap;
 import org.jetbrains.kotlin.platform.JavaToKotlinClassMap.PlatformMutabilityMapping;
 import org.jetbrains.kotlin.psi.*;
-import org.jetbrains.kotlin.resolve.BindingContext;
-import org.jetbrains.kotlin.resolve.DelegationResolver;
-import org.jetbrains.kotlin.resolve.DescriptorToSourceUtils;
-import org.jetbrains.kotlin.resolve.DescriptorUtils;
+import org.jetbrains.kotlin.resolve.*;
 import org.jetbrains.kotlin.resolve.calls.callUtil.CallUtilKt;
 import org.jetbrains.kotlin.resolve.calls.model.ResolvedCall;
 import org.jetbrains.kotlin.resolve.calls.model.VariableAsFunctionResolvedCall;
@@ -251,6 +248,35 @@ public class ImplementationBodyCodegen extends ClassBodyCodegen {
         new ErasedInlineClassBodyCodegen((KtClass) myClass, erasedInlineClassContext, builder, state, this).generate();
     }
 
+    @Override
+    protected void generateUnboxMethodForInlineClass() {
+        if (!(myClass instanceof KtClass)) return;
+        if (!descriptor.isInline()) return;
+
+        Type ownerType = typeMapper.mapClass(descriptor);
+        ValueParameterDescriptor inlinedValue = InlineClassesUtilsKt.underlyingRepresentation(this.descriptor);
+        if (inlinedValue == null) return;
+
+        Type valueType = typeMapper.mapType(inlinedValue.getType());
+        SimpleFunctionDescriptor functionDescriptor = InlineClassDescriptorResolver.INSTANCE.createUnboxFunctionDescriptor(this.descriptor);
+        assert functionDescriptor != null : "FunctionDescriptor for unbox method should be not null during codegen";
+
+        functionCodegen.generateMethod(
+                JvmDeclarationOriginKt.UnboxMethodOfInlineClass(functionDescriptor), functionDescriptor,
+                new FunctionGenerationStrategy.CodegenBased(state) {
+                    @Override
+                    public void doGenerateBody(
+                            @NotNull ExpressionCodegen codegen, @NotNull JvmMethodSignature signature
+                    ) {
+                        InstructionAdapter iv = codegen.v;
+                        iv.load(0, OBJECT_TYPE);
+                        iv.getfield(ownerType.getInternalName(), inlinedValue.getName().asString(), valueType.getDescriptor());
+                        iv.areturn(valueType);
+                    }
+                }
+        );
+    }
+
     @Override
     protected void generateKotlinMetadataAnnotation() {
         generateKotlinClassMetadataAnnotation(descriptor, false);

compiler/frontend.java/src/org/jetbrains/kotlin/resolve/jvm/diagnostics/JvmDeclarationOrigin.kt

@@ -30,7 +30,8 @@ enum class JvmDeclarationOriginKind {
     SYNTHETIC, // this means that there's no proper descriptor for this jvm declaration,
     COLLECTION_STUB,
     AUGMENTED_BUILTIN_API,
-    ERASED_INLINE_CLASS
+    ERASED_INLINE_CLASS,
+    UNBOX_METHOD_OF_INLINE_CLASS
 }
 
 class JvmDeclarationOrigin(
@@ -83,3 +84,6 @@ fun AugmentedBuiltInApi(descriptor: CallableDescriptor): JvmDeclarationOrigin =
 
 fun ErasedInlineClassOrigin(element: PsiElement?, descriptor: ClassDescriptor): JvmDeclarationOrigin =
     JvmDeclarationOrigin(ERASED_INLINE_CLASS, element, descriptor)
+
+fun UnboxMethodOfInlineClass(descriptor: FunctionDescriptor): JvmDeclarationOrigin =
+    JvmDeclarationOrigin(UNBOX_METHOD_OF_INLINE_CLASS, null, descriptor)

compiler/testData/codegen/bytecodeListing/inlineClasses/shapeOfInlineClassWithPrimitive.txt

@@ -14,4 +14,5 @@ public final class Foo {
     public final method extension(@org.jetbrains.annotations.NotNull p0: java.lang.Object, @org.jetbrains.annotations.NotNull p1: java.lang.String): void
     public final method getL(): long
     public final method param(p0: double): void
+    public final method unbox(): long
 }