Minor refactorings related to PackagePartProvider and implementations

- Document what exactly should findPackageParts return
- Make EMPTY a named object instead of a val in the companion
- Do not use JvmPackagePartProvider in tests where Empty works fine
- Add a couple default values to arguments of setupResolverForProject

compiler/builtins-serializer/src/org/jetbrains/kotlin/serialization/builtins/BuiltInsSerializer.kt

@@ -23,11 +23,9 @@ import org.jetbrains.kotlin.analyzer.ModuleContent
 import org.jetbrains.kotlin.analyzer.ModuleInfo
 import org.jetbrains.kotlin.builtins.BuiltInSerializerProtocol
 import org.jetbrains.kotlin.builtins.BuiltInsBinaryVersion
-import org.jetbrains.kotlin.builtins.DefaultBuiltIns
 import org.jetbrains.kotlin.cli.common.CLIConfigurationKeys
 import org.jetbrains.kotlin.cli.common.messages.MessageCollector
 import org.jetbrains.kotlin.cli.jvm.compiler.EnvironmentConfigFiles
-import org.jetbrains.kotlin.cli.jvm.compiler.JvmPackagePartProvider
 import org.jetbrains.kotlin.cli.jvm.compiler.KotlinCoreEnvironment
 import org.jetbrains.kotlin.cli.jvm.config.addJvmClasspathRoots
 import org.jetbrains.kotlin.config.CompilerConfiguration
@@ -38,7 +36,6 @@ import org.jetbrains.kotlin.descriptors.ClassKind
 import org.jetbrains.kotlin.descriptors.PackageFragmentDescriptor
 import org.jetbrains.kotlin.descriptors.PackageViewDescriptor
 import org.jetbrains.kotlin.name.Name
-import org.jetbrains.kotlin.resolve.CompilerEnvironment
 import org.jetbrains.kotlin.resolve.jvm.JvmAnalyzerFacade
 import org.jetbrains.kotlin.resolve.jvm.JvmPlatformParameters
 import org.jetbrains.kotlin.resolve.scopes.DescriptorKindFilter
@@ -91,10 +88,7 @@ class BuiltInsSerializer(private val dependOnOldBuiltIns: Boolean) {
                 "builtIns source",
                 ProjectContext(environment.project), listOf(builtInModule),
                 { ModuleContent(files, GlobalSearchScope.EMPTY_SCOPE) },
-                JvmPlatformParameters { throw IllegalStateException() },
+                JvmPlatformParameters { throw IllegalStateException() }
-                CompilerEnvironment,
-                builtIns = DefaultBuiltIns.Instance,
-                packagePartProviderFactory = { module, content -> JvmPackagePartProvider(environment) }
         )
 
         val moduleDescriptor = resolver.descriptorForModule(builtInModule)

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

@@ -17,6 +17,7 @@
 package org.jetbrains.kotlin.analyzer
 
 import com.intellij.psi.search.GlobalSearchScope
+import org.jetbrains.kotlin.builtins.DefaultBuiltIns
 import org.jetbrains.kotlin.builtins.KotlinBuiltIns
 import org.jetbrains.kotlin.container.ComponentProvider
 import org.jetbrains.kotlin.context.ModuleContext
@@ -31,6 +32,7 @@ import org.jetbrains.kotlin.descriptors.impl.ModuleDescriptorImpl
 import org.jetbrains.kotlin.name.FqName
 import org.jetbrains.kotlin.name.Name
 import org.jetbrains.kotlin.psi.KtFile
+import org.jetbrains.kotlin.resolve.CompilerEnvironment
 import org.jetbrains.kotlin.resolve.TargetEnvironment
 import org.jetbrains.kotlin.resolve.TargetPlatform
 import org.jetbrains.kotlin.resolve.createModule
@@ -147,10 +149,10 @@ abstract class AnalyzerFacade<in P : PlatformAnalysisParameters> {
             modules: Collection<M>,
             modulesContent: (M) -> ModuleContent,
             platformParameters: P,
-            targetEnvironment: TargetEnvironment,
+            targetEnvironment: TargetEnvironment = CompilerEnvironment,
-            builtIns: KotlinBuiltIns,
+            builtIns: KotlinBuiltIns = DefaultBuiltIns.Instance,
             delegateResolver: ResolverForProject<M> = EmptyResolverForProject(),
-            packagePartProviderFactory: (M, ModuleContent) -> PackagePartProvider = { module, content -> PackagePartProvider.EMPTY },
+            packagePartProviderFactory: (M, ModuleContent) -> PackagePartProvider = { module, content -> PackagePartProvider.Empty },
             firstDependency: M? = null
     ): ResolverForProject<M> {
         val storageManager = projectContext.storageManager

compiler/tests-common/org/jetbrains/kotlin/codegen/GenerationUtils.java

@@ -53,7 +53,7 @@ public class GenerationUtils {
     @NotNull
     public static GenerationState compileFiles(@NotNull List<KtFile> files, @Nullable KotlinCoreEnvironment environment) {
         PackagePartProvider packagePartProvider =
-                environment == null ? PackagePartProvider.Companion.getEMPTY() : new JvmPackagePartProvider(environment);
+                environment == null ? PackagePartProvider.Empty.INSTANCE : new JvmPackagePartProvider(environment);
         CompilerConfiguration configuration =
                 environment == null ? KotlinTestUtils.newConfiguration() : environment.getConfiguration();
 

compiler/tests-common/org/jetbrains/kotlin/resolve/lazy/lazyResolveTestUtils.kt

@@ -20,12 +20,10 @@ import com.intellij.openapi.project.Project
 import com.intellij.psi.search.GlobalSearchScope
 import org.jetbrains.kotlin.analyzer.ModuleContent
 import org.jetbrains.kotlin.analyzer.ModuleInfo
-import org.jetbrains.kotlin.builtins.DefaultBuiltIns
 import org.jetbrains.kotlin.container.get
 import org.jetbrains.kotlin.context.ProjectContext
 import org.jetbrains.kotlin.name.Name
 import org.jetbrains.kotlin.psi.KtFile
-import org.jetbrains.kotlin.resolve.CompilerEnvironment
 import org.jetbrains.kotlin.resolve.jvm.JvmAnalyzerFacade
 import org.jetbrains.kotlin.resolve.jvm.JvmPlatformParameters
 
@@ -40,9 +38,7 @@ fun createResolveSessionForFiles(
             "test",
             projectContext, listOf(testModule),
             { ModuleContent(syntheticFiles, GlobalSearchScope.allScope(project)) },
-            JvmPlatformParameters { testModule },
+            JvmPlatformParameters { testModule }
-            CompilerEnvironment,
-            DefaultBuiltIns.Instance
     )
     return resolverForProject.resolverForModule(testModule).componentProvider.get<ResolveSession>()
 }

compiler/tests-java8/tests/org/jetbrains/kotlin/serialization/builtins/AdditionalBuiltInsMembersSignatureListsTest.kt

@@ -54,7 +54,7 @@ class AdditionalBuiltInsMembersSignatureListsTest : KotlinTestWithEnvironment()
 
         val container = createContainerForTopDownSingleModuleAnalyzerForJvm(
                 moduleContext, CliLightClassGenerationSupport.CliBindingTrace(), providerFactory,
-                GlobalSearchScope.allScope(environment.project), PackagePartProvider.EMPTY
+                GlobalSearchScope.allScope(environment.project), PackagePartProvider.Empty
         )
 
         emptyModule.initialize(container.get<JavaDescriptorResolver>().packageFragmentProvider)

compiler/tests/org/jetbrains/kotlin/jvm/compiler/MultiModuleJavaAnalysisCustomTest.kt

@@ -24,7 +24,6 @@ import org.jetbrains.kotlin.analyzer.ModuleInfo
 import org.jetbrains.kotlin.analyzer.ResolverForProject
 import org.jetbrains.kotlin.builtins.KotlinBuiltIns
 import org.jetbrains.kotlin.cli.jvm.compiler.EnvironmentConfigFiles
-import org.jetbrains.kotlin.cli.jvm.compiler.JvmPackagePartProvider
 import org.jetbrains.kotlin.cli.jvm.compiler.KotlinCoreEnvironment
 import org.jetbrains.kotlin.config.LanguageFeature
 import org.jetbrains.kotlin.config.LanguageVersionSettings
@@ -36,7 +35,6 @@ import org.jetbrains.kotlin.name.FqName
 import org.jetbrains.kotlin.name.Name
 import org.jetbrains.kotlin.platform.JvmBuiltIns
 import org.jetbrains.kotlin.psi.KtFile
-import org.jetbrains.kotlin.resolve.CompilerEnvironment
 import org.jetbrains.kotlin.resolve.constants.EnumValue
 import org.jetbrains.kotlin.resolve.descriptorUtil.module
 import org.jetbrains.kotlin.resolve.jvm.JvmAnalyzerFacade
@@ -69,15 +67,13 @@ class MultiModuleJavaAnalysisCustomTest : KtUsefulTestCase() {
         val resolverForProject = JvmAnalyzerFacade.setupResolverForProject(
                 "test",
                 projectContext, modules,
-                { m -> ModuleContent(m.kotlinFiles, m.javaFilesScope) },
+                { module -> ModuleContent(module.kotlinFiles, module.javaFilesScope) },
                 JvmPlatformParameters {
                     javaClass ->
                     val moduleName = javaClass.name.asString().toLowerCase().first().toString()
                     modules.first { it._name == moduleName }
                 },
-                CompilerEnvironment,
+                builtIns = builtIns
-                builtIns,
-                packagePartProviderFactory = { a, b -> JvmPackagePartProvider(environment) }
         )
 
         builtIns.initialize(
@@ -113,7 +109,7 @@ class MultiModuleJavaAnalysisCustomTest : KtUsefulTestCase() {
                     "a" -> listOf(this)
                     "b" -> listOf(this, modules["a"]!!)
                     "c" -> listOf(this, modules["b"]!!, modules["a"]!!)
-                    else -> throw IllegalStateException("$_name")
+                    else -> throw IllegalStateException(_name)
                 }
             }
         }
@@ -190,7 +186,7 @@ class MultiModuleJavaAnalysisCustomTest : KtUsefulTestCase() {
         assert(!ErrorUtils.isError(referencedDescriptor)) { "Error descriptor: $referencedDescriptor" }
 
         val descriptorName = referencedDescriptor.name.asString()
-        val expectedModuleName = "<${descriptorName.toLowerCase().first().toString()}>"
+        val expectedModuleName = "<${descriptorName.toLowerCase().first()}>"
         val moduleName = referencedDescriptor.module.name.asString()
         Assert.assertEquals(
                 "Java class $descriptorName in $context should be in module $expectedModuleName, but instead was in $moduleName",

compiler/tests/org/jetbrains/kotlin/serialization/AbstractLocalClassProtoTest.kt

@@ -61,7 +61,7 @@ abstract class AbstractLocalClassProtoTest : TestCaseWithTmpdir() {
 
         val container = createContainerForTopDownSingleModuleAnalyzerForJvm(
                 moduleContext, CliLightClassGenerationSupport.NoScopeRecordCliBindingTrace(),
-                providerFactory, GlobalSearchScope.allScope(environment.project), PackagePartProvider.EMPTY
+                providerFactory, GlobalSearchScope.allScope(environment.project), PackagePartProvider.Empty
         )
         moduleContext.initializeModuleContents(container.get<JavaDescriptorResolver>().packageFragmentProvider)
 

compiler/tests/org/jetbrains/kotlin/serialization/builtins/AbstractBuiltInsWithJDKMembersTest.kt

@@ -62,7 +62,7 @@ abstract class AbstractBuiltInsWithJDKMembersTest : KotlinTestWithEnvironment()
 
         val container = createContainerForTopDownSingleModuleAnalyzerForJvm(
                 moduleContext, CliLightClassGenerationSupport.CliBindingTrace(), providerFactory,
-                GlobalSearchScope.allScope(environment.project), PackagePartProvider.EMPTY
+                GlobalSearchScope.allScope(environment.project), PackagePartProvider.Empty
         )
 
         emptyModule.initialize(container.get<JavaDescriptorResolver>().packageFragmentProvider)

core/descriptors/src/org/jetbrains/kotlin/descriptors/PackagePartProvider.kt

@@ -17,17 +17,15 @@
 package org.jetbrains.kotlin.descriptors
 
 interface PackagePartProvider {
-
     /**
-     * return package part simple names
+     * @return simple names of package parts existing in the package with the given FQ name.
+     *
+     * For example, if a file named foo.kt in package org.test is compiled to a library, PackagePartProvider for such library
+     * must return the list `["FooKt"]` for the query `"org.test"` (in case the file is not annotated with @JvmName or @JvmMultifile*)
      */
     fun findPackageParts(packageFqName: String): List<String>
 
-    companion object {
+    object Empty : PackagePartProvider {
-        val EMPTY: PackagePartProvider = object : PackagePartProvider {
+        override fun findPackageParts(packageFqName: String): List<String> = emptyList()
-            override fun findPackageParts(packageFqName: String): List<String> {
-                return emptyList()
-            }
-        }
     }
 }