Decompiler: Introduce DeserializerForDecompiler

Component which can "resolve" descriptors without project
It builds dummy descriptors for dependencies which are enough to build decompiled text

compiler/frontend/serialization/src/org/jetbrains/jet/descriptors/serialization/ClassId.java

@@ -22,6 +22,12 @@ import org.jetbrains.jet.lang.resolve.name.FqNameUnsafe;
 import org.jetbrains.jet.lang.resolve.name.Name;
 
 public final class ClassId {
+
+    @NotNull
+    public static ClassId topLevel(@NotNull FqName topLevelFqName) {
+        return new ClassId(topLevelFqName.parent(), FqNameUnsafe.topLevel(topLevelFqName.shortName()));
+    }
+
     private final FqName packageFqName;
     private final FqNameUnsafe relativeClassName;
 
@@ -55,6 +61,7 @@ public final class ClassId {
         return relativeClassName.parent().isRoot();
     }
 
+    @NotNull
     public FqNameUnsafe asSingleFqName() {
         if (packageFqName.isRoot()) return relativeClassName;
         return new FqNameUnsafe(packageFqName.asString() + "." + relativeClassName.asString());

compiler/frontend/serialization/src/org/jetbrains/jet/descriptors/serialization/DescriptorFinder.java

@@ -18,6 +18,7 @@ package org.jetbrains.jet.descriptors.serialization;
 
 import org.jetbrains.annotations.NotNull;
 import org.jetbrains.annotations.Nullable;
+import org.jetbrains.annotations.ReadOnly;
 import org.jetbrains.jet.lang.descriptors.ClassDescriptor;
 import org.jetbrains.jet.lang.resolve.name.FqName;
 import org.jetbrains.jet.lang.resolve.name.Name;
@@ -43,6 +44,7 @@ public interface DescriptorFinder {
     @Nullable
     ClassDescriptor findClass(@NotNull ClassId classId);
 
+    @ReadOnly
     @NotNull
     Collection<Name> getClassNames(@NotNull FqName packageName);
 }

idea/src/org/jetbrains/jet/plugin/libraries/DeserializerForDecompiler.kt

@@ -0,0 +1,188 @@
+/*
+ * Copyright 2010-2014 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.jet.plugin.libraries
+
+import org.jetbrains.jet.descriptors.serialization.ClassId
+import org.jetbrains.jet.descriptors.serialization.DescriptorFinder
+import org.jetbrains.jet.descriptors.serialization.JavaProtoBufUtil
+import org.jetbrains.jet.descriptors.serialization.descriptors.DeserializedClassDescriptor
+import org.jetbrains.jet.lang.descriptors.*
+import org.jetbrains.jet.lang.descriptors.impl.MutablePackageFragmentDescriptor
+import org.jetbrains.jet.lang.resolve.kotlin.KotlinJvmBinaryClass
+import org.jetbrains.jet.lang.resolve.name.FqName
+import org.jetbrains.jet.lang.resolve.name.Name
+import org.jetbrains.jet.lang.types.ErrorUtils
+import org.jetbrains.jet.storage.LockBasedStorageManager
+import java.util.Collections
+import org.jetbrains.jet.lang.resolve.java.resolver.DescriptorResolverUtils
+import com.intellij.openapi.vfs.VirtualFile
+import org.jetbrains.jet.lang.resolve.kotlin.KotlinBinaryClassCache
+import org.jetbrains.jet.lang.resolve.kotlin.DeserializedResolverUtils
+import org.jetbrains.jet.descriptors.serialization.descriptors.DeserializedPackageMemberScope
+import org.jetbrains.jet.lang.resolve.kotlin.AnnotationDescriptorDeserializer
+import org.jetbrains.jet.lang.resolve.java.resolver.ErrorReporter
+import org.jetbrains.jet.lang.types.ErrorUtils.getErrorModule
+import org.jetbrains.jet.lang.types.error.MissingDependencyErrorClassDescriptor
+import org.jetbrains.jet.lang.resolve.java.PackageClassUtils
+import com.intellij.openapi.diagnostic.Logger
+import org.jetbrains.jet.lang.resolve.kotlin.KotlinClassFinder
+import org.jetbrains.jet.lang.resolve.name.FqNameUnsafe
+
+public fun DeserializerForDecompiler(classFile: VirtualFile): DeserializerForDecompiler {
+    val kotlinClass = KotlinBinaryClassCache.getKotlinBinaryClass(classFile)
+    val classFqName = kotlinClass.getClassName().getFqNameForClassNameWithoutDollars()
+    val packageFqName = classFqName.parent()
+    return DeserializerForDecompiler(classFile.getParent()!!, packageFqName)
+}
+
+public class DeserializerForDecompiler(val packageDirectory: VirtualFile, val directoryPackageFqName: FqName) : ResolverForDecompiler {
+
+    override fun resolveClass(classFqName: FqName) = classes(classFqName.toClassId())
+
+    override fun resolveDeclarationsInPackage(packageFqName: FqName): Collection<DeclarationDescriptor> {
+        assert(packageFqName == directoryPackageFqName, "Was called for $packageFqName but only $directoryPackageFqName is expected.")
+        val packageClassFqName = PackageClassUtils.getPackageClassFqName(packageFqName)
+        val binaryClassForPackageClass = localClassFinder.findKotlinClass(packageClassFqName)
+        val annotationData = binaryClassForPackageClass?.getClassHeader()?.getAnnotationData()
+        if (annotationData == null) {
+            LOG.error("Could not read annotation data for $packageFqName from ${binaryClassForPackageClass?.getClassName()}")
+            return Collections.emptyList()
+        }
+        val membersScope = DeserializedPackageMemberScope(
+                storageManager,
+                createDummyPackageFragment(packageFqName),
+                annotationDeserializer,
+                descriptorFinder,
+                JavaProtoBufUtil.readPackageDataFrom(annotationData)
+        )
+        return membersScope.getAllDescriptors()
+    }
+
+    private val localClassFinder = object: KotlinClassFinder {
+        override fun findKotlinClass(fqName: FqName) = findKotlinClass(fqName.toClassId())
+
+        fun findKotlinClass(classId: ClassId): KotlinJvmBinaryClass? {
+            if (classId.getPackageFqName() != directoryPackageFqName) {
+                return null
+            }
+            val segments = DeserializedResolverUtils.kotlinFqNameToJavaFqName(classId.getRelativeClassName()).pathSegments()
+            val targetName = segments.makeString("$", postfix = ".class")
+            val virtualFile = packageDirectory.findChild(targetName)
+            if (virtualFile != null && DecompiledUtils.isKotlinCompiledFile(virtualFile)) {
+                return KotlinBinaryClassCache.getKotlinBinaryClass(virtualFile)
+            }
+            return null
+        }
+    }
+    private val storageManager = LockBasedStorageManager.NO_LOCKS
+    private val classes = storageManager.createMemoizedFunctionWithNullableValues {
+        (classId: ClassId) ->
+        resolveClassByClassId(classId)
+    }
+
+    private val annotationDeserializer = AnnotationDescriptorDeserializer(storageManager);
+    {
+        annotationDeserializer.setClassResolver {
+            fqName ->
+            classes(fqName.toClassId())
+        }
+        annotationDeserializer.setKotlinClassFinder(localClassFinder)
+        annotationDeserializer.setErrorReporter(LOGGING_REPORTER)
+    }
+
+    private val descriptorFinder = object : DescriptorFinder {
+        override fun findClass(classId: ClassId): ClassDescriptor? {
+            return classes(classId)
+        }
+
+        override fun getClassNames(packageName: FqName): Collection<Name> {
+            return Collections.emptyList()
+        }
+    }
+
+    private val packageFragmentProvider = object : PackageFragmentProvider {
+        override fun getPackageFragments(fqName: FqName): List<PackageFragmentDescriptor> {
+            return listOf(createDummyPackageFragment(fqName))
+        }
+
+        override fun getSubPackagesOf(fqName: FqName): Collection<FqName> {
+            throw UnsupportedOperationException("This method is not supposed to be called.")
+        }
+    }
+
+    private fun createDummyPackageFragment(fqName: FqName): MutablePackageFragmentDescriptor {
+        return MutablePackageFragmentDescriptor(ErrorUtils.getErrorModule(), fqName)
+    }
+
+    private fun resolveClassByClassId(classId: ClassId): ClassDescriptor? {
+        val fullFqName = classId.asSingleFqName()
+        if (fullFqName.isSafe()) {
+            val fromBuiltIns = DescriptorResolverUtils.getKotlinBuiltinClassDescriptor(fullFqName.toSafe())
+            if (fromBuiltIns != null) {
+                return fromBuiltIns
+            }
+        }
+        val binaryClass = localClassFinder.findKotlinClass(classId)
+        if (binaryClass != null) {
+            return deserializeBinaryClass(binaryClass)
+        }
+        assert(fullFqName.isSafe(), "Safe fq name expected here, got $fullFqName instead")
+        return MissingDependencyErrorClassDescriptor(fullFqName.toSafe())
+    }
+
+    private fun deserializeBinaryClass(kotlinClass: KotlinJvmBinaryClass): ClassDescriptor {
+        val data = kotlinClass.getClassHeader()?.getAnnotationData()
+        if (data == null) {
+            LOG.error("Annotation data missing for ${kotlinClass.getClassName()}")
+        }
+        val classData = JavaProtoBufUtil.readClassDataFrom(data!!)
+        return DeserializedClassDescriptor(storageManager, annotationDeserializer, descriptorFinder, packageFragmentProvider,
+                                           classData.getNameResolver(), classData.getClassProto())
+    }
+
+    // we need a "magic" way to obtain ClassId from FqName
+    // the idea behind this function is that we need accurate class ids only for "neighbouring" classes (inner classes, class object, etc)
+    // for all others we can build any ClassId since it will resolve to MissingDependencyErrorClassDescriptor which only stores fqName
+    private fun FqName.toClassId(): ClassId {
+        val segments = pathSegments()
+        val packageSegmentsCount = directoryPackageFqName.pathSegments().size
+        if (segments.size <= packageSegmentsCount) {
+            return ClassId.topLevel(this)
+        }
+        val packageFqName = FqName.fromSegments(segments.subList(0, packageSegmentsCount) map { it.asString() })
+        if (packageFqName == directoryPackageFqName) {
+            return ClassId(packageFqName, FqNameUnsafe.fromSegments(segments.subList(packageSegmentsCount, segments.size)))
+        }
+        return ClassId.topLevel(this)
+    }
+
+    class object {
+        private val LOG = Logger.getInstance(javaClass<DeserializerForDecompiler>())
+
+        private object LOGGING_REPORTER: ErrorReporter {
+            override fun reportAnnotationLoadingError(message: String, exception: Exception?) {
+                LOG.error(message, exception)
+            }
+            override fun reportCannotInferVisibility(descriptor: CallableMemberDescriptor) {
+                LOG.error("Could not infer visibility for $descriptor")
+            }
+            override fun reportIncompatibleAbiVersion(kotlinClass: KotlinJvmBinaryClass, actualVersion: Int) {
+                LOG.error("Incompatible ABI version for class ${kotlinClass.getClassName()}, actual version: $actualVersion")
+            }
+        }
+    }
+}