From 1ac4e9755ad5a7c0a2042848e9620ecb949a69a6 Mon Sep 17 00:00:00 2001
From: Mikhail Zarechenskiy <mikhail.zarechenskiy@jetbrains.com>
Date: Mon, 5 Feb 2018 03:46:00 +0300
Subject: [PATCH] Generate synthetic `unbox` method for each wrapper of inline
 class

---
 .../kotlin/codegen/ClassBodyCodegen.java      |  3 ++
 .../kotlin/codegen/FunctionCodegen.java       |  3 +-
 .../codegen/ImplementationBodyCodegen.java    | 34 ++++++++++++++++---
 .../jvm/diagnostics/JvmDeclarationOrigin.kt   |  6 +++-
 .../shapeOfInlineClassWithPrimitive.txt       |  1 +
 5 files changed, 41 insertions(+), 6 deletions(-)

diff --git a/compiler/backend/src/org/jetbrains/kotlin/codegen/ClassBodyCodegen.java b/compiler/backend/src/org/jetbrains/kotlin/codegen/ClassBodyCodegen.java
index b1cfc81d0bc..d562522ceaa 100644
--- a/compiler/backend/src/org/jetbrains/kotlin/codegen/ClassBodyCodegen.java
+++ b/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);
     }
diff --git a/compiler/backend/src/org/jetbrains/kotlin/codegen/FunctionCodegen.java b/compiler/backend/src/org/jetbrains/kotlin/codegen/FunctionCodegen.java
index e0e8b3a1ade..5dba959bde9 100644
--- a/compiler/backend/src/org/jetbrains/kotlin/codegen/FunctionCodegen.java
+++ b/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(
diff --git a/compiler/backend/src/org/jetbrains/kotlin/codegen/ImplementationBodyCodegen.java b/compiler/backend/src/org/jetbrains/kotlin/codegen/ImplementationBodyCodegen.java
index 5fa4cb3e698..a8102952d6d 100644
--- a/compiler/backend/src/org/jetbrains/kotlin/codegen/ImplementationBodyCodegen.java
+++ b/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);
diff --git a/compiler/frontend.java/src/org/jetbrains/kotlin/resolve/jvm/diagnostics/JvmDeclarationOrigin.kt b/compiler/frontend.java/src/org/jetbrains/kotlin/resolve/jvm/diagnostics/JvmDeclarationOrigin.kt
index 036646f94e1..160d70df623 100644
--- a/compiler/frontend.java/src/org/jetbrains/kotlin/resolve/jvm/diagnostics/JvmDeclarationOrigin.kt
+++ b/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)
diff --git a/compiler/testData/codegen/bytecodeListing/inlineClasses/shapeOfInlineClassWithPrimitive.txt b/compiler/testData/codegen/bytecodeListing/inlineClasses/shapeOfInlineClassWithPrimitive.txt
index 3bd9ab7fb09..94d688d8843 100644
--- a/compiler/testData/codegen/bytecodeListing/inlineClasses/shapeOfInlineClassWithPrimitive.txt
+++ b/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
 }