Add debug strings to frontend scopes-related structures

Such as:
- PackageFragmentProviders, and, in particular,
CompositePackageFragmentProviders
- JavaPackageFragments
- Scopes produced by those providers

The rationale is that a lot of frontend-facing bugs (like red code) are
easily recognizeable in resolution. But at that point you just see a
bunch of scopes, without meaningful toStrings, you don't know who has
produced them, and what's exactly wrong.

With this commit it should make debugging slightly easier: now at least
you'll be able to see that "this scope is a scope of package fragment
for foo.bar of module baz" and decide whether the declaration should or
should not have been resolved from such scope.

compiler/cli/src/org/jetbrains/kotlin/cli/jvm/compiler/TopDownAnalyzerFacadeForJVM.kt

@@ -209,7 +209,8 @@ object TopDownAnalyzerFacadeForJVM {
                         moduleClassResolver.compiledCodeResolver.packageFragmentProvider,
                         dependenciesContainer.get<JvmBuiltInsPackageFragmentProvider>(),
                         dependenciesContainer.get<OptionalAnnotationPackageFragmentProvider>()
-                    )
+                    ),
+                    "CompositeProvider@TopDownAnalyzerForJvm for dependencies ${dependenciesContext.module}"
                 )
             )
             dependenciesContext.module
@@ -283,7 +284,8 @@ object TopDownAnalyzerFacadeForJVM {
                 listOf(
                     container.get<KotlinCodeAnalyzer>().packageFragmentProvider,
                     container.get<OptionalAnnotationPackageFragmentProvider>()
-                ) + additionalProviders
+                ) + additionalProviders,
+                "CompositeProvider@TopDownAnalzyerForJvm for $module"
             )
         )
 

compiler/frontend.java/src/org/jetbrains/kotlin/load/kotlin/incremental/IncrementalPackageFragmentProvider.kt

@@ -104,8 +104,9 @@ class IncrementalPackageFragmentProvider(
                             JvmPackagePartSource(
                                 partName, facadeName, packageProto, nameResolver, knownJvmBinaryClass = jvmBinaryClass
                             ),
-                            deserializationComponents, classNames = { emptyList() }
-                        )
+                            deserializationComponents,
+                            "scope for IncrementalMultifileClassPackageFragment for facadeName=$facadeName, packageFqName=$packageFqName, part $partName",
+                        ) { emptyList() }
                     }
                 }
             )

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

@@ -133,6 +133,9 @@ class JvmResolverForModuleFactory(
                     )
                 }
 
-        return ResolverForModule(CompositePackageFragmentProvider(providersForModule), container)
+        return ResolverForModule(
+            CompositePackageFragmentProvider(providersForModule, "CompositeProvider@JvmResolver for $moduleDescriptor"),
+            container
+        )
     }
 }

compiler/frontend/src/org/jetbrains/kotlin/analyzer/AbstractResolverForProject.kt

@@ -269,6 +269,10 @@ private class DelegatingPackageFragmentProvider<M : ModuleInfo>(
 
         return !packageOracle.packageExists(fqName) && fqName !in syntheticFilePackages
     }
+
+    override fun toString(): String {
+        return "DelegatingProvider for $module in ${resolverForProject.name}"
+    }
 }
 
 private object DiagnoseUnknownModuleInfoReporter {

compiler/frontend/src/org/jetbrains/kotlin/analyzer/common/CommonResolverForModuleFactory.kt

@@ -112,7 +112,10 @@ class CommonResolverForModuleFactory(
                     container.get<MetadataPackageFragmentProvider>()
                 )
 
-        return ResolverForModule(CompositePackageFragmentProvider(packageFragmentProviders), container)
+        return ResolverForModule(
+            CompositePackageFragmentProvider(packageFragmentProviders, "CompositeProvider@CommonResolver for $moduleDescriptor"),
+            container
+        )
     }
 
     companion object {

compiler/tests-common-new/tests/org/jetbrains/kotlin/test/frontend/classic/ClassicFrontendFacade.kt

@@ -225,7 +225,8 @@ class ClassicFrontendFacade(
                 listOf(
                     container.get<KotlinCodeAnalyzer>().packageFragmentProvider,
                     container.get<JavaDescriptorResolver>().packageFragmentProvider
-                )
+                ),
+                "CompositeProvider@ClassicFrontendFacade for $moduleDescriptor"
             )
         )
 

compiler/tests-common/tests/org/jetbrains/kotlin/checkers/AbstractDiagnosticsTest.kt

@@ -437,7 +437,8 @@ abstract class AbstractDiagnosticsTest : BaseDiagnosticsTest() {
                 listOf(
                     container.get<KotlinCodeAnalyzer>().packageFragmentProvider,
                     container.get<JavaDescriptorResolver>().packageFragmentProvider
-                )
+                ),
+                "CompositeProvider@AbstractDiagnosticsTest for $moduleDescriptor"
             )
         )
 

compiler/util-klib-metadata/src/org/jetbrains/kotlin/library/metadata/KlibMetadataPackageFragment.kt

@@ -94,10 +94,9 @@ abstract class KlibMetadataPackageFragment(
             nameResolver,
             KlibMetadataVersion.INSTANCE,
             /* containerSource = */ null,
-            components
-        ) {
-            loadClassNames()
-        }
+            components,
+            "scope for $this"
+        ) { loadClassNames() }
     }
 
     override fun getMemberScope(): DeserializedPackageMemberScope = _memberScope

compiler/util-klib-metadata/src/org/jetbrains/kotlin/library/metadata/impl/KlibMetadataModuleDescriptorFactoryImpl.kt

@@ -183,7 +183,10 @@ class KlibMetadataModuleDescriptorFactoryImpl(
         }
 
         return compositePackageFragmentAddend?.let {
-            CompositePackageFragmentProvider(listOf(it, provider))
+            CompositePackageFragmentProvider(
+                listOf(it, provider),
+                "CompositeProvider@KlibMetadataModuleDescriptorFactory for $moduleDescriptor"
+            )
         } ?: provider
     }
 

core/descriptors.jvm/src/org/jetbrains/kotlin/load/java/lazy/LazyJavaPackageFragmentProvider.kt

@@ -52,4 +52,6 @@ class LazyJavaPackageFragmentProvider(
 
     override fun getSubPackagesOf(fqName: FqName, nameFilter: (Name) -> Boolean) =
         getPackageFragment(fqName)?.getSubPackageFqNames().orEmpty()
+
+    override fun toString(): String = "LazyJavaPackageFragmentProvider of module ${c.components.module}"
 }

core/descriptors.jvm/src/org/jetbrains/kotlin/load/java/lazy/descriptors/JvmPackageScope.kt

@@ -103,4 +103,6 @@ class JvmPackageScope(
     override fun recordLookup(name: Name, location: LookupLocation) {
         c.components.lookupTracker.record(location, packageFragment, name)
     }
+
+    override fun toString(): String = "scope for $packageFragment"
 }

core/descriptors.jvm/src/org/jetbrains/kotlin/load/java/lazy/descriptors/LazyJavaPackageFragment.kt

@@ -35,7 +35,7 @@ import org.jetbrains.kotlin.storage.getValue
 
 class LazyJavaPackageFragment(
     outerContext: LazyJavaResolverContext,
-    private val jPackage: JavaPackage
+    private val jPackage: JavaPackage,
 ) : PackageFragmentDescriptorImpl(outerContext.module, jPackage.fqName) {
     private val c = outerContext.childForClassOrPackage(this)
 
@@ -86,7 +86,7 @@ class LazyJavaPackageFragment(
 
     override fun getMemberScope() = scope
 
-    override fun toString() = "Lazy Java package fragment: $fqName"
+    override fun toString() = "Lazy Java package fragment: $fqName of module ${c.components.module}"
 
     override fun getSource(): SourceElement = KotlinJvmBinaryPackageSourceElement(this)
 }

core/descriptors.jvm/src/org/jetbrains/kotlin/load/kotlin/DeserializedDescriptorResolver.kt

@@ -70,7 +70,8 @@ class DeserializedDescriptorResolver {
             kotlinClass.abiStability
         )
         return DeserializedPackageMemberScope(
-            descriptor, packageProto, nameResolver, kotlinClass.classHeader.metadataVersion, source, components
+            descriptor, packageProto, nameResolver, kotlinClass.classHeader.metadataVersion, source, components,
+            "scope for $source in $descriptor"
         ) {
             // All classes are included into Java scope
             emptyList()

core/descriptors.runtime/src/org/jetbrains/kotlin/descriptors/runtime/components/RuntimeModuleData.kt

@@ -92,7 +92,12 @@ class RuntimeModuleData private constructor(
             )
 
             module.setDependencies(module)
-            module.initialize(CompositePackageFragmentProvider(listOf(javaDescriptorResolver.packageFragmentProvider, builtinsProvider)))
+            module.initialize(
+                CompositePackageFragmentProvider(
+                    listOf(javaDescriptorResolver.packageFragmentProvider, builtinsProvider),
+                    "CompositeProvider@RuntimeModuleData for $module"
+                )
+            )
 
             return RuntimeModuleData(
                 deserializationComponentsForJava.components,

core/descriptors/src/org/jetbrains/kotlin/descriptors/impl/CompositePackageFragmentProvider.kt

@@ -22,7 +22,8 @@ import java.util.*
 import org.jetbrains.kotlin.name.Name
 
 class CompositePackageFragmentProvider(// can be modified from outside
-    private val providers: List<PackageFragmentProvider>
+    private val providers: List<PackageFragmentProvider>,
+    private val debugName: String
 ) : PackageFragmentProviderOptimized {
 
     init {
@@ -55,4 +56,6 @@ class CompositePackageFragmentProvider(// can be modified from outside
         }
         return result
     }
+
+    override fun toString(): String = debugName
 }

core/descriptors/src/org/jetbrains/kotlin/descriptors/impl/ModuleDescriptorImpl.kt

@@ -101,9 +101,12 @@ class ModuleDescriptorImpl @JvmOverloads constructor(
                 "Dependency module ${dependency.id} was not initialized by the time contents of dependent module ${this.id} were queried"
             }
         }
-        CompositePackageFragmentProvider(dependenciesDescriptors.map {
-            it.packageFragmentProviderForModuleContent!!
-        })
+        CompositePackageFragmentProvider(
+            dependenciesDescriptors.map {
+                it.packageFragmentProviderForModuleContent!!
+            },
+            "CompositeProvider@ModuleDescriptor for $name"
+        )
     }
 
     private val isInitialized: Boolean

core/descriptors/src/org/jetbrains/kotlin/descriptors/impl/PackageFragmentDescriptorImpl.kt

@@ -22,12 +22,16 @@ import org.jetbrains.kotlin.descriptors.PackageFragmentDescriptor
 import org.jetbrains.kotlin.descriptors.SourceElement
 import org.jetbrains.kotlin.descriptors.annotations.Annotations
 import org.jetbrains.kotlin.name.FqName
+import org.jetbrains.kotlin.resolve.descriptorUtil.module
 
 abstract class PackageFragmentDescriptorImpl(
         module: ModuleDescriptor,
         final override val fqName: FqName
 ) : DeclarationDescriptorNonRootImpl(module, Annotations.EMPTY, fqName.shortNameOrSpecial(), SourceElement.NO_SOURCE),
         PackageFragmentDescriptor {
+    // Not inlined in order to not capture ref on 'module'
+    private val debugString: String = "package $fqName of $module"
+
     override fun <R, D> accept(visitor: DeclarationDescriptorVisitor<R, D>, data: D): R =
             visitor.visitPackageFragmentDescriptor(this, data)
 
@@ -39,5 +43,5 @@ abstract class PackageFragmentDescriptorImpl(
         return SourceElement.NO_SOURCE
     }
 
-    override fun toString(): String = "package $fqName"
+    override fun toString(): String = debugString
 }

core/descriptors/src/org/jetbrains/kotlin/descriptors/impl/SubpackagesScope.kt

@@ -66,4 +66,6 @@ open class SubpackagesScope(private val moduleDescriptor: ModuleDescriptor, priv
         p.popIndent()
         p.println("}")
     }
+
+    override fun toString(): String = "subpackages of $fqName from $moduleDescriptor"
 }

core/deserialization/src/org/jetbrains/kotlin/serialization/deserialization/DeserializedPackageFragmentImpl.kt

@@ -49,12 +49,13 @@ abstract class DeserializedPackageFragmentImpl(
         _proto = null
         _memberScope = DeserializedPackageMemberScope(
             this, proto.`package`, nameResolver, metadataVersion, containerSource, components,
-            classNames = {
-                classDataFinder.allClassIds.filter { classId ->
-                    !classId.isNestedClass && classId !in ClassDeserializer.BLACK_LIST
-                }.map { it.shortClassName }
-            }
-        )
+            "scope of $this"
+        ) {
+            classDataFinder.allClassIds.filter { classId ->
+                !classId.isNestedClass && classId !in ClassDeserializer.BLACK_LIST
+            }.map { it.shortClassName }
+        }
+
     }
 
     override fun getMemberScope(): MemberScope = _memberScope

core/deserialization/src/org/jetbrains/kotlin/serialization/deserialization/MetadataPackageFragmentProvider.kt

@@ -110,10 +110,18 @@ class MetadataPackageFragment(
             val stream = finder.findMetadata(ClassId(fqName, Name.identifier(partName))) ?: continue
             val (proto, nameResolver, version) = readProto(stream)
 
-            scopes.add(DeserializedPackageMemberScope(
-                this, proto.`package`, nameResolver, version, containerSource = null, components = components,
-                classNames = { emptyList() }
-            ))
+            scopes.add(
+                DeserializedPackageMemberScope(
+                    this,
+                    proto.`package`,
+                    nameResolver,
+                    version,
+                    containerSource = null,
+                    components = components,
+                    debugName = "scope with top-level callables and type aliases (no classes) for package part $partName of $this",
+                    classNames = { emptyList() },
+                )
+            )
         }
 
         // Also add the deserialized scope that can load all classes from this package
@@ -121,7 +129,9 @@ class MetadataPackageFragment(
             this, ProtoBuf.Package.getDefaultInstance(),
             NameResolverImpl(ProtoBuf.StringTable.getDefaultInstance(), ProtoBuf.QualifiedNameTable.getDefaultInstance()),
             BuiltInsBinaryVersion.INSTANCE, // Exact version does not matter here
-            containerSource = null, components = components, classNames = { emptyList() }
+            containerSource = null, components = components,
+            debugName = "scope for all classes of $this",
+            classNames = { emptyList() },
         ) {
             override fun hasClass(name: Name): Boolean = hasTopLevelClass(name)
             override fun definitelyDoesNotContainName(name: Name) = false
@@ -129,7 +139,7 @@ class MetadataPackageFragment(
             override fun getNonDeclaredClassifierNames(): Set<Name>? = null
         })
 
-        return ChainedMemberScope.create("Metadata scope", scopes)
+        return ChainedMemberScope.create(".kotlin_metadata parts scope of $this", scopes)
     }
 
     override fun getMemberScope() = memberScope()

core/deserialization/src/org/jetbrains/kotlin/serialization/deserialization/builtins/BuiltInsPackageFragmentImpl.kt

@@ -10,6 +10,7 @@ import org.jetbrains.kotlin.descriptors.ModuleDescriptor
 import org.jetbrains.kotlin.metadata.ProtoBuf
 import org.jetbrains.kotlin.metadata.builtins.BuiltInsBinaryVersion
 import org.jetbrains.kotlin.name.FqName
+import org.jetbrains.kotlin.resolve.descriptorUtil.module
 import org.jetbrains.kotlin.serialization.deserialization.DeserializedPackageFragmentImpl
 import org.jetbrains.kotlin.storage.StorageManager
 import java.io.InputStream
@@ -52,4 +53,6 @@ class BuiltInsPackageFragmentImpl private constructor(
             return BuiltInsPackageFragmentImpl(fqName, storageManager, module, proto, version, isFallback)
         }
     }
+
+    override fun toString(): String = "builtins package fragment for $fqName from $module"
 }

core/deserialization/src/org/jetbrains/kotlin/serialization/deserialization/descriptors/DeserializedPackageMemberScope.kt

@@ -39,7 +39,8 @@ open class DeserializedPackageMemberScope(
     metadataVersion: BinaryVersion,
     containerSource: DeserializedContainerSource?,
     components: DeserializationComponents,
-    classNames: () -> Collection<Name>
+    private val debugName: String,
+    classNames: () -> Collection<Name>,
 ) : DeserializedMemberScope(
     components.createContext(
         packageDescriptor, nameResolver, TypeTable(proto.typeTable),
@@ -74,4 +75,6 @@ open class DeserializedPackageMemberScope(
     override fun addEnumEntryDescriptors(result: MutableCollection<DeclarationDescriptor>, nameFilter: (Name) -> Boolean) {
         // Do nothing
     }
+
+    override fun toString(): String = debugName
 }

idea/idea-analysis/src/org/jetbrains/kotlin/caches/resolve/CompositeResolverForModuleFactory.kt

@@ -112,7 +112,13 @@ class CompositeResolverForModuleFactory(
             yieldAll(getNativeProvidersIfAny(moduleInfo, container))
         }.toList()
 
-        return ResolverForModule(CompositePackageFragmentProvider(packageFragmentProviders), container)
+        return ResolverForModule(
+            CompositePackageFragmentProvider(
+                packageFragmentProviders,
+                "CompositeProvider@CompositeResolver for $moduleDescriptor"
+            ),
+            container
+        )
     }
 
     private fun getCommonProvidersIfAny(

idea/idea-analysis/src/org/jetbrains/kotlin/caches/resolve/JsResolverForModuleFactory.kt

@@ -66,7 +66,10 @@ class JsResolverForModuleFactory(
         val libraryProviders = createPackageFragmentProvider(moduleInfo, container, moduleContext, moduleDescriptor)
 
         if (libraryProviders.isNotEmpty()) {
-            packageFragmentProvider = CompositePackageFragmentProvider(listOf(packageFragmentProvider) + libraryProviders)
+            packageFragmentProvider = CompositePackageFragmentProvider(
+                listOf(packageFragmentProvider) + libraryProviders,
+                "CompositeProvider@JsResolver for $moduleDescriptor"
+            )
         }
 
         return ResolverForModule(packageFragmentProvider, container)

idea/idea-analysis/src/org/jetbrains/kotlin/idea/caches/lightClasses/IDELightClassContexts.kt

@@ -403,7 +403,12 @@ internal object IDELightClassContexts {
 
 
         val resolveSession = container.get<ResolveSession>()
-        moduleDescriptor.initialize(CompositePackageFragmentProvider(listOf(resolveSession.packageFragmentProvider)))
+        moduleDescriptor.initialize(
+            CompositePackageFragmentProvider(
+                listOf(resolveSession.packageFragmentProvider),
+                "CompositeProvider@IDELightClassContexts for $moduleDescriptor"
+            )
+        )
         return resolveSession
     }
 

idea/idea-analysis/src/org/jetbrains/kotlin/idea/decompiler/classFile/DeserializerForClassfileDecompiler.kt

@@ -85,10 +85,12 @@ class DeserializerForClassfileDecompiler(
             return emptyList()
         }
         val (nameResolver, packageProto) = JvmProtoBufUtil.readPackageDataFrom(annotationData, strings)
+        val dummyPackageFragment = createDummyPackageFragment(header.packageName?.let(::FqName) ?: facadeFqName.parent())
         val membersScope = DeserializedPackageMemberScope(
-            createDummyPackageFragment(header.packageName?.let(::FqName) ?: facadeFqName.parent()),
+            dummyPackageFragment,
             packageProto, nameResolver, header.metadataVersion,
-            JvmPackagePartSource(binaryClassForPackageClass, packageProto, nameResolver), deserializationComponents
+            JvmPackagePartSource(binaryClassForPackageClass, packageProto, nameResolver), deserializationComponents,
+            "scope of dummyPackageFragment ${dummyPackageFragment.fqName} in module $moduleDescriptor @DeserializerForClassfileDecompiler"
         ) { emptyList() }
         return membersScope.getContributedDescriptors().toList()
     }

idea/idea-analysis/src/org/jetbrains/kotlin/idea/decompiler/common/KotlinMetadataDeserializerForDecompiler.kt

@@ -55,9 +55,12 @@ class KotlinMetadataDeserializerForDecompiler(
             "Was called for $facadeFqName; only members of $directoryPackageFqName package are expected."
         }
 
+        val dummyPackageFragment = createDummyPackageFragment(facadeFqName)
         val membersScope = DeserializedPackageMemberScope(
-            createDummyPackageFragment(facadeFqName), proto.`package`, nameResolver, metadataVersion, containerSource = null,
-            components = deserializationComponents
+            dummyPackageFragment, proto.`package`, nameResolver, metadataVersion, containerSource = null,
+            components = deserializationComponents,
+            debugName = "scope of dummyPackageFragment ${dummyPackageFragment.fqName} in module " +
+                    "${deserializationComponents.moduleDescriptor} @KotlinMetadataDeserializerForDecompiler"
         ) { emptyList() }
 
         return membersScope.getContributedDescriptors().toList()

idea/idea-analysis/src/org/jetbrains/kotlin/idea/klib/KlibMetadataDeserializerForDecompiler.kt

@@ -60,8 +60,11 @@ class KlibMetadataDeserializerForDecompiler(
             nameResolver,
             KlibMetadataVersion.INSTANCE,
             containerSource = null,
-            components = deserializationComponents
-        ) { emptyList() }
+            components = deserializationComponents,
+            classNames = { emptyList() },
+            debugName = "scope of dummyPackageFragment $facadeFqName in ${deserializationComponents.moduleDescriptor} " +
+                    "@KlibMetadataDeserializerForDecompiler"
+        )
 
         return membersScope.getContributedDescriptors().toList()
     }

idea/idea-native/src/org/jetbrains/kotlin/ide/konan/NativePlatformKindResolution.kt

@@ -136,7 +136,8 @@ class NativePlatformKindResolution : IdePlatformKindResolution {
                     functionInterfacePackageFragmentProvider(storageManager, builtInsModule),
                     (metadataFactories.DefaultDeserializedDescriptorFactory as KlibMetadataModuleDescriptorFactoryImpl)
                         .createForwardDeclarationHackPackagePartProvider(storageManager, builtInsModule)
-                )
+                ),
+                "CompositeProvider@NativeBuiltins for $builtInsModule"
             )
         )
 

idea/idea-native/src/org/jetbrains/kotlin/ide/konan/analyzer/NativeResolverForModuleFactory.kt

@@ -66,7 +66,10 @@ class NativeResolverForModuleFactory(
             )
 
         if (klibPackageFragmentProvider != null) {
-            packageFragmentProvider = CompositePackageFragmentProvider(listOf(packageFragmentProvider, klibPackageFragmentProvider))
+            packageFragmentProvider = CompositePackageFragmentProvider(
+                listOf(packageFragmentProvider, klibPackageFragmentProvider),
+                "CompositeProvider@NativeResolver for $moduleDescriptor"
+            )
         }
 
         return ResolverForModule(packageFragmentProvider, container)

js/js.frontend/src/org/jetbrains/kotlin/frontend/js/di/injection.kt

@@ -66,7 +66,9 @@ fun createContainerForJS(
         val packagePartProviders = mutableListOf(get<KotlinCodeAnalyzer>().packageFragmentProvider)
         val moduleDescriptor = get<ModuleDescriptorImpl>()
         packagePartProviders += additionalPackages
-        moduleDescriptor.initialize(CompositePackageFragmentProvider(packagePartProviders))
+        moduleDescriptor.initialize(
+            CompositePackageFragmentProvider(packagePartProviders, "CompositeProvider@createContainerForJS for $moduleDescriptor")
+        )
     }
     return storageComponentContainer
 }

kotlin-native/backend.native/compiler/ir/backend.native/src/org/jetbrains/kotlin/backend/konan/injection.kt

@@ -43,6 +43,11 @@ fun createTopDownAnalyzerProviderForKonan(
         val packagePartProviders = mutableListOf(get<KotlinCodeAnalyzer>().packageFragmentProvider)
         val moduleDescriptor = get<ModuleDescriptorImpl>()
         packagePartProviders += additionalPackages
-        moduleDescriptor.initialize(CompositePackageFragmentProvider(packagePartProviders))
+        moduleDescriptor.initialize(
+                CompositePackageFragmentProvider(
+                        packagePartProviders,
+                        "CompositeProvider@createTopDownAnalyzerProviderForKonan for module ${moduleContext.module}"
+                )
+        )
     }
 }