Decompilation support

- class header reader for KotlinMultifileClass, KotlinMultifileClassPart
- proper implClassName for multifile class members

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

@@ -27,10 +27,7 @@ import org.jetbrains.annotations.Nullable;
 import org.jetbrains.kotlin.backend.common.bridges.Bridge;
 import org.jetbrains.kotlin.backend.common.bridges.BridgesPackage;
 import org.jetbrains.kotlin.codegen.annotation.AnnotatedWithOnlyTargetedAnnotations;
-import org.jetbrains.kotlin.codegen.context.CodegenContext;
+import org.jetbrains.kotlin.codegen.context.*;
-import org.jetbrains.kotlin.codegen.context.MethodContext;
-import org.jetbrains.kotlin.codegen.context.PackageContext;
-import org.jetbrains.kotlin.codegen.context.PackageFacadeContext;
 import org.jetbrains.kotlin.codegen.optimization.OptimizationMethodVisitor;
 import org.jetbrains.kotlin.codegen.state.GenerationState;
 import org.jetbrains.kotlin.codegen.state.JetTypeMapper;
@@ -163,15 +160,11 @@ public class FunctionCodegen {
                                        jvmSignature.getGenericsSignature(),
                                        getThrownExceptions(functionDescriptor, typeMapper));
 
-        if (owner instanceof PackageFacadeContext) {
+        String implClassName = CodegenContextUtil.getImplClassNameByOwnerIfRequired(owner);
-            Type ownerType = ((PackageFacadeContext) owner).getDelegateToClassType();
+        if (implClassName != null) {
-            v.getSerializationBindings().put(IMPL_CLASS_NAME_FOR_CALLABLE, functionDescriptor, shortNameByAsmType(ownerType));
+            v.getSerializationBindings().put(IMPL_CLASS_NAME_FOR_CALLABLE, functionDescriptor, implClassName);
         }
-        else {
+        if (CodegenContextUtil.isImplClassOwner(owner)) {
-            if (owner instanceof PackageContext) {
-                Type ownerType = ((PackageContext) owner).getPackagePartType();
-                v.getSerializationBindings().put(IMPL_CLASS_NAME_FOR_CALLABLE, functionDescriptor, shortNameByAsmType(ownerType));
-            }
             v.getSerializationBindings().put(METHOD_FOR_FUNCTION, functionDescriptor, asmMethod);
         }
 

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

@@ -110,15 +110,12 @@ public class PropertyCodegen {
         assert kind == OwnerKind.PACKAGE || kind == OwnerKind.IMPLEMENTATION || kind == OwnerKind.TRAIT_IMPL
                 : "Generating property with a wrong kind (" + kind + "): " + descriptor;
 
-        if (context instanceof PackageFacadeContext) {
+        Type implClassType = CodegenContextUtil.getImplClassTypeByOwnerIfRequired(context);
-            Type ownerType = ((PackageFacadeContext) context).getDelegateToClassType();
+        if (implClassType != null) {
-            v.getSerializationBindings().put(IMPL_CLASS_NAME_FOR_CALLABLE, descriptor, shortNameByAsmType(ownerType));
+            v.getSerializationBindings().put(IMPL_CLASS_NAME_FOR_CALLABLE, descriptor, shortNameByAsmType(implClassType));
         }
-        else {
+
-            if (context instanceof PackageContext) {
+        if (CodegenContextUtil.isImplClassOwner(context)) {
-                Type ownerType = ((PackageContext) context).getPackagePartType();
-                v.getSerializationBindings().put(IMPL_CLASS_NAME_FOR_CALLABLE, descriptor, shortNameByAsmType(ownerType));
-            }
             assert declaration != null : "Declaration is null for different context: " + context;
 
             boolean hasBackingField = hasBackingField(declaration, descriptor);

compiler/backend/src/org/jetbrains/kotlin/codegen/context/CodegenContextUtil.kt

@@ -0,0 +1,41 @@
+/*
+ * Copyright 2010-2015 JetBrains s.r.o.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.jetbrains.kotlin.codegen.context
+
+import org.jetbrains.kotlin.codegen.AsmUtil
+import org.jetbrains.org.objectweb.asm.Type
+
+
+public object CodegenContextUtil {
+    public @JvmStatic fun getImplClassTypeByOwnerIfRequired(owner: CodegenContext<*>): Type? =
+            when (owner) {
+                is PackageFacadeContext ->
+                        owner.delegateToClassType
+                is PackageContext ->
+                        owner.packagePartType
+                is MultifileClassOrPartContext ->
+                        owner.filePartType
+                else ->
+                        null
+            }
+
+    public @JvmStatic fun getImplClassNameByOwnerIfRequired(owner: CodegenContext<*>): String? =
+            getImplClassTypeByOwnerIfRequired(owner)?.let{ AsmUtil.shortNameByAsmType(it) }
+
+    public @JvmStatic fun isImplClassOwner(owner: CodegenContext<*>): Boolean =
+            !(owner is PackageFacadeContext || owner is MultifileClassContext)
+}

compiler/backend/src/org/jetbrains/kotlin/codegen/context/MultifileClassContext.java

@@ -21,26 +21,14 @@ import org.jetbrains.kotlin.descriptors.DeclarationDescriptor;
 import org.jetbrains.kotlin.descriptors.PackageFragmentDescriptor;
 import org.jetbrains.org.objectweb.asm.Type;
 
-public class MultifileClassContext extends FieldOwnerContext<PackageFragmentDescriptor> {
+public class MultifileClassContext extends MultifileClassOrPartContext {
-    private final Type multifileClassType;
-    private final Type filePartType;
-
     public MultifileClassContext(
             PackageFragmentDescriptor descriptor,
             CodegenContext parent,
             Type multifileClassType,
             Type filePartType
     ) {
-        super(descriptor, OwnerKind.PACKAGE, parent, null, null, null);
+        super(descriptor, parent, multifileClassType, filePartType);
-        this.multifileClassType = multifileClassType;
-        this.filePartType = filePartType;
     }
 
-    public Type getMultifileClassType() {
-        return multifileClassType;
-    }
-
-    public Type getFilePartType() {
-        return filePartType;
-    }
 }

compiler/backend/src/org/jetbrains/kotlin/codegen/context/MultifileClassOrPartContext.java

@@ -0,0 +1,45 @@
+/*
+ * Copyright 2010-2015 JetBrains s.r.o.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.jetbrains.kotlin.codegen.context;
+
+import org.jetbrains.kotlin.codegen.OwnerKind;
+import org.jetbrains.kotlin.descriptors.PackageFragmentDescriptor;
+import org.jetbrains.org.objectweb.asm.Type;
+
+public class MultifileClassOrPartContext extends FieldOwnerContext<PackageFragmentDescriptor> {
+    private final Type multifileClassType;
+    private final Type filePartType;
+
+    public MultifileClassOrPartContext(
+            PackageFragmentDescriptor descriptor,
+            CodegenContext parent,
+            Type multifileClassType,
+            Type filePartType
+    ) {
+        super(descriptor, OwnerKind.PACKAGE, parent, null, null, null);
+        this.multifileClassType = multifileClassType;
+        this.filePartType = filePartType;
+    }
+
+    public Type getMultifileClassType() {
+        return multifileClassType;
+    }
+
+    public Type getFilePartType() {
+        return filePartType;
+    }
+}

compiler/backend/src/org/jetbrains/kotlin/codegen/context/MultifileClassPartContext.java

@@ -21,26 +21,14 @@ import org.jetbrains.kotlin.descriptors.DeclarationDescriptor;
 import org.jetbrains.kotlin.descriptors.PackageFragmentDescriptor;
 import org.jetbrains.org.objectweb.asm.Type;
 
-public class MultifileClassPartContext extends FieldOwnerContext<PackageFragmentDescriptor> {
+public class MultifileClassPartContext extends MultifileClassOrPartContext {
-    private final Type multifileClassType;
-    private final Type filePartType;
-
     public MultifileClassPartContext(
             PackageFragmentDescriptor descriptor,
             CodegenContext parent,
             Type multifileClassType,
             Type filePartType
     ) {
-        super(descriptor, OwnerKind.PACKAGE, parent, null, null, null);
+        super(descriptor, parent, multifileClassType, filePartType);
-        this.multifileClassType = multifileClassType;
-        this.filePartType = filePartType;
     }
 
-    public Type getMultifileClassType() {
-        return multifileClassType;
-    }
-
-    public Type getFilePartType() {
-        return filePartType;
-    }
 }

core/descriptor.loader.java/src/org/jetbrains/kotlin/load/kotlin/AbstractBinaryClassAnnotationAndConstantLoader.kt

@@ -226,7 +226,8 @@ public abstract class AbstractBinaryClassAnnotationAndConstantLoader<A : Any, C
             nameResolver: NameResolver
     ): KotlinJvmBinaryClass? {
         if (proto.hasExtension(implClassName)) {
-            return kotlinClassFinder.findKotlinClass(ClassId(packageFqName, nameResolver.getName(proto.getExtension(implClassName))))
+            val implClassName = nameResolver.getName(proto.getExtension(implClassName))
+            return kotlinClassFinder.findKotlinClass(ClassId(packageFqName, implClassName))
         }
         return null
     }

core/descriptor.loader.java/src/org/jetbrains/kotlin/load/kotlin/header/ReadKotlinClassHeaderAnnotationVisitor.java

@@ -120,6 +120,10 @@ public class ReadKotlinClassHeaderAnnotationVisitor implements AnnotationVisitor
                     return new PackageHeaderReader();
                 case FILE_FACADE:
                     return new FileFacadeHeaderReader();
+                case MULTIFILE_CLASS:
+                    return new MultifileClassHeaderReader();
+                case MULTIFILE_CLASS_PART:
+                    return new MultifileClassPartHeaderReader();
                 case SYNTHETIC_CLASS:
                     return new SyntheticClassHeaderReader();
                 default:
@@ -259,6 +263,18 @@ public class ReadKotlinClassHeaderAnnotationVisitor implements AnnotationVisitor
         }
     }
 
+    private class MultifileClassHeaderReader extends HeaderAnnotationArgumentVisitor {
+        public MultifileClassHeaderReader() {
+            super(JvmClassName.byFqNameWithoutInnerClasses(KOTLIN_MULTIFILE_CLASS));
+        }
+    }
+
+    private class MultifileClassPartHeaderReader extends HeaderAnnotationArgumentVisitor {
+        public MultifileClassPartHeaderReader() {
+            super(JvmClassName.byFqNameWithoutInnerClasses(KOTLIN_MULTIFILE_CLASS_PART));
+        }
+    }
+
     private class SyntheticClassHeaderReader extends HeaderAnnotationArgumentVisitor {
         public SyntheticClassHeaderReader() {
             super(KotlinSyntheticClass.CLASS_NAME);

idea/idea-analysis/src/org/jetbrains/kotlin/idea/decompiler/DecompiledUtils.kt

@@ -21,10 +21,15 @@ import com.intellij.openapi.util.Key
 import com.intellij.openapi.vfs.VirtualFile
 import com.intellij.psi.ClassFileViewProvider
 import org.jetbrains.kotlin.idea.caches.JarUserDataManager
+import org.jetbrains.kotlin.idea.decompiler.textBuilder.DirectoryBasedClassFinder
 import org.jetbrains.kotlin.load.java.JvmAnnotationNames.KotlinClass
 import org.jetbrains.kotlin.load.java.JvmAnnotationNames.KotlinSyntheticClass
 import org.jetbrains.kotlin.load.kotlin.KotlinBinaryClassCache
+import org.jetbrains.kotlin.load.kotlin.KotlinJvmBinaryClass
 import org.jetbrains.kotlin.load.kotlin.header.KotlinClassHeader
+import org.jetbrains.kotlin.name.ClassId
+import org.jetbrains.kotlin.name.FqName
+import org.jetbrains.kotlin.name.Name
 
 /**
  * Checks if this file is a compiled Kotlin class file (not necessarily ABI-compatible with the current plugin)
@@ -83,3 +88,27 @@ public object HasCompiledKotlinInJar : JarUserDataManager.JarBooleanPropertyCoun
     fun isInNoKotlinJar(file: VirtualFile): Boolean =
             JarUserDataManager.hasFileWithProperty(HasCompiledKotlinInJar, file) == false
 }
+
+public class ReadMultifileClassException(message: String): RuntimeException(message)
+
+public fun findMultifileClassParts(file: VirtualFile, multifileClass: KotlinJvmBinaryClass): List<KotlinJvmBinaryClass> {
+    val result = arrayListOf<KotlinClassHeader>()
+    val packageFqName = multifileClass.classId.packageFqName
+    val partsFinder = DirectoryBasedClassFinder(file.parent!!, packageFqName)
+    val partNames = multifileClass.classHeader.filePartClassNames ?: return emptyList()
+    return partNames.map {
+        partsFinder.findKotlinClass(ClassId(packageFqName, Name.identifier(it)))
+    }.filterNotNull()
+}
+
+@Throws(ReadMultifileClassException::class)
+public fun readMultifileClassPartHeaders(file: VirtualFile, multifileClass: KotlinJvmBinaryClass): List<KotlinClassHeader> {
+    val classId = multifileClass.classId
+    val classHeader = multifileClass.classHeader
+    if (classHeader.filePartClassNames == null) {
+        throw ReadMultifileClassException("Multifile class $classId has no filePartClassNames or wrong ABI version: ${classHeader.version}")
+    }
+    else {
+        return findMultifileClassParts(file, multifileClass).map { it.classHeader }
+    }
+}

idea/idea-analysis/src/org/jetbrains/kotlin/idea/decompiler/stubBuilder/KotlinClsStubBuilder.kt

@@ -22,7 +22,9 @@ import com.intellij.psi.compiled.ClsStubBuilder
 import com.intellij.psi.impl.compiled.ClassFileStubBuilder
 import com.intellij.psi.stubs.PsiFileStub
 import com.intellij.util.indexing.FileContent
+import org.jetbrains.kotlin.idea.decompiler.ReadMultifileClassException
 import org.jetbrains.kotlin.idea.decompiler.isKotlinInternalCompiledFile
+import org.jetbrains.kotlin.idea.decompiler.readMultifileClassPartHeaders
 import org.jetbrains.kotlin.idea.decompiler.textBuilder.DirectoryBasedClassFinder
 import org.jetbrains.kotlin.idea.decompiler.textBuilder.DirectoryBasedDataFinder
 import org.jetbrains.kotlin.idea.decompiler.textBuilder.LoggingErrorReporter
@@ -83,32 +85,20 @@ public open class KotlinClsStubBuilder : ClsStubBuilder() {
             header.isCompatibleMultifileClassKind() -> {
                 val packageData = JvmProtoBufUtil.readPackageDataFrom(annotationData)
                 val context = components.createContext(packageData.nameResolver, packageFqName)
-                val partHeaders = readMultifileClassPartHeaders(file, header, packageFqName)
+                val partHeaders =
-                partHeaders?.let {
+                    try {
-                    createMultifileClassStub(it, classId.asSingleFqName(), context)
+                        readMultifileClassPartHeaders(file, kotlinBinaryClass)
-                }
+                    }
+                    catch (e: ReadMultifileClassException) {
+                        LOG.error(e.getMessage())
+                        return null
+                    }
+                createMultifileClassStub(partHeaders, classId.asSingleFqName(), context)
             }
             else -> throw IllegalStateException("Should have processed " + file.getPath() + " with header $header")
         }
     }
 
-    private fun readMultifileClassPartHeaders(file: VirtualFile, header: KotlinClassHeader, packageFqName: FqName): List<KotlinClassHeader>? {
-        val result = arrayListOf<KotlinClassHeader>()
-        val partsFinder = DirectoryBasedClassFinder(file.parent!!, packageFqName)
-        val partNames = header.filePartClassNames
-        if (partNames != null) {
-            for (partName in partNames) {
-                val partClass = partsFinder.findKotlinClass(ClassId.topLevel(packageFqName.child(Name.identifier(partName))))
-                if (partClass == null) {
-                    LOG.error("Missing part class: $packageFqName.$partName")
-                    return null
-                }
-                result.add(partClass.classHeader)
-            }
-        }
-        return result
-    }
-
     private fun createStubBuilderComponents(file: VirtualFile, packageFqName: FqName): ClsStubBuilderComponents {
         val classFinder = DirectoryBasedClassFinder(file.getParent()!!, packageFqName)
         val classDataFinder = DirectoryBasedDataFinder(classFinder, LOG)

idea/idea-analysis/src/org/jetbrains/kotlin/idea/decompiler/textBuilder/DecompiledTextFactory.kt

@@ -19,12 +19,16 @@ package org.jetbrains.kotlin.idea.decompiler.textBuilder
 import com.intellij.openapi.util.TextRange
 import com.intellij.openapi.vfs.VirtualFile
 import org.jetbrains.kotlin.descriptors.*
+import org.jetbrains.kotlin.idea.decompiler.ReadMultifileClassException
+import org.jetbrains.kotlin.idea.decompiler.findMultifileClassParts
 import org.jetbrains.kotlin.idea.decompiler.navigation.JsMetaFileUtils
+import org.jetbrains.kotlin.idea.decompiler.readMultifileClassPartHeaders
 import org.jetbrains.kotlin.load.java.JvmAbi
 import org.jetbrains.kotlin.load.kotlin.KotlinBinaryClassCache
 import org.jetbrains.kotlin.load.kotlin.PackageClassUtils
 import org.jetbrains.kotlin.load.kotlin.header.isCompatibleClassKind
 import org.jetbrains.kotlin.load.kotlin.header.isCompatibleFileFacadeKind
+import org.jetbrains.kotlin.load.kotlin.header.isCompatibleMultifileClassKind
 import org.jetbrains.kotlin.load.kotlin.header.isCompatiblePackageFacadeKind
 import org.jetbrains.kotlin.name.FqName
 import org.jetbrains.kotlin.renderer.DescriptorRenderer
@@ -47,6 +51,12 @@ public val INCOMPATIBLE_ABI_VERSION_COMMENT: String =
         "// Current compiler ABI version is $CURRENT_ABI_VERSION_MARKER\n" +
         "// File ABI version is $FILE_ABI_VERSION_MARKER"
 
+private val REASON = "REASON"
+public val FILE_CANT_BE_DECOMPILED_DUE_TO_ERRORS: String =
+        "// This class file has inconsistent Kotlin meta-information and can't be decompiled.\n" +
+        "//\n" +
+        "// $REASON"
+
 public fun buildDecompiledText(
         classFile: VirtualFile,
         resolver: ResolverForDecompiler = DeserializerForDecompiler(classFile)
@@ -70,6 +80,11 @@ public fun buildDecompiledText(
             buildDecompiledText(packageFqName, ArrayList(resolver.resolveDeclarationsInFacade(classId.asSingleFqName())))
         classHeader.isCompatibleClassKind() ->
             buildDecompiledText(packageFqName, listOf(resolver.resolveTopLevelClass(classId)).filterNotNull())
+        classHeader.isCompatibleMultifileClassKind() -> {
+            val partClasses = findMultifileClassParts(classFile, kotlinClass)
+            val partMembers = partClasses.flatMap { partClass -> resolver.resolveDeclarationsInFacade(partClass.classId.asSingleFqName()) }
+            buildDecompiledText(packageFqName, partMembers)
+        }
         else ->
             throw UnsupportedOperationException("Unknown header kind: ${classHeader.kind} ${classHeader.isCompatibleAbiVersion}")
     }

idea/testData/decompiler/decompiledTextJvm/MultifileClass.expected.kt

@@ -0,0 +1,12 @@
+// IntelliJ API Decompiler stub source generated from a class file
+// Implementation of methods is not available
+
+package test
+
+public val p: kotlin.Int /* compiled code */
+
+public fun f(): kotlin.Unit { /* compiled code */ }
+
+private var i: kotlin.Int /* compiled code */
+
+public fun kotlin.Int.plus(i: kotlin.Int /* = compiled code */): kotlin.Int { /* compiled code */ }

idea/testData/decompiler/decompiledTextJvm/MultifileClass/MultifileClass.kt

@@ -0,0 +1,10 @@
+@file:JvmName("MultifileClass")
+@file:JvmMultifileClass
+package test
+
+private var i = 2
+
+fun Int.plus(i: Int = 1) = this + i
+
+class ShouldNotBeVisible1
+interface ShouldNotBeVisible2

idea/testData/decompiler/decompiledTextJvm/MultifileClass/andSomeMore.kt

@@ -0,0 +1,6 @@
+@file:JvmName("MultifileClass")
+@file:JvmMultifileClass
+package test
+
+fun f() {}
+val p = 3

idea/tests/org/jetbrains/kotlin/idea/decompiler/textBuilder/JvmDecompiledTextTestGenerated.java

@@ -35,6 +35,12 @@ public class JvmDecompiledTextTestGenerated extends AbstractJvmDecompiledTextTes
         JetTestUtils.assertAllTestsPresentByMetadata(this.getClass(), new File("idea/testData/decompiler/decompiledTextJvm"), Pattern.compile("^([^\\.]+)$"), true);
     }
 
+    @TestMetadata("MultifileClass")
+    public void testMultifileClass() throws Exception {
+        String fileName = JetTestUtils.navigationMetadata("idea/testData/decompiler/decompiledTextJvm/MultifileClass/");
+        doTest(fileName);
+    }
+
     @TestMetadata("TestKt")
     public void testTestKt() throws Exception {
         String fileName = JetTestUtils.navigationMetadata("idea/testData/decompiler/decompiledTextJvm/TestKt/");