[Expect/Actual] Introduce ModuleStructureOracle

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

@@ -107,7 +107,8 @@ fun createContainerForBodyResolve(
     platform: TargetPlatform,
     statementFilter: StatementFilter,
     analyzerServices: PlatformDependentAnalyzerServices,
-    languageVersionSettings: LanguageVersionSettings
+    languageVersionSettings: LanguageVersionSettings,
+    moduleStructureOracle: ModuleStructureOracle
 ): StorageComponentContainer = createContainer("BodyResolve", analyzerServices) {
     configureModule(moduleContext, platform, analyzerServices, bindingTrace, languageVersionSettings)
 
@@ -117,6 +118,7 @@ fun createContainerForBodyResolve(
     useImpl<AnnotationResolverImpl>()
 
     useImpl<BodyResolver>()
+    useInstance(moduleStructureOracle)
 }
 
 fun createContainerForLazyBodyResolve(
@@ -126,7 +128,8 @@ fun createContainerForLazyBodyResolve(
     platform: TargetPlatform,
     bodyResolveCache: BodyResolveCache,
     analyzerServices: PlatformDependentAnalyzerServices,
-    languageVersionSettings: LanguageVersionSettings
+    languageVersionSettings: LanguageVersionSettings,
+    moduleStructureOracle: ModuleStructureOracle
 ): StorageComponentContainer = createContainer("LazyBodyResolve", analyzerServices) {
     configureModule(moduleContext, platform, analyzerServices, bindingTrace, languageVersionSettings)
 
@@ -136,6 +139,7 @@ fun createContainerForLazyBodyResolve(
     useImpl<AnnotationResolverImpl>()
     useImpl<LazyTopDownAnalyzer>()
     useImpl<BasicAbsentDescriptorHandler>()
+    useInstance(moduleStructureOracle)
 }
 
 fun createContainerForLazyLocalClassifierAnalyzer(

compiler/frontend/src/org/jetbrains/kotlin/resolve/CompilerEnvironment.kt

@@ -27,5 +27,6 @@ object CompilerEnvironment : TargetEnvironment("Compiler") {
         container.useInstance(BodyResolveCache.ThrowException)
         container.useImpl<CompilerLocalDescriptorResolver>()
         container.useImpl<BasicAbsentDescriptorHandler>()
+        container.useInstance(ModuleStructureOracle.SingleModule)
     }
 }

compiler/frontend/src/org/jetbrains/kotlin/resolve/ModuleStructureOracle.kt

@@ -0,0 +1,34 @@
+/*
+ * Copyright 2010-2019 JetBrains s.r.o. Use of this source code is governed by the Apache 2.0 license
+ * that can be found in the license/LICENSE.txt file.
+ */
+
+package org.jetbrains.kotlin.resolve
+
+import org.jetbrains.kotlin.descriptors.ModuleDescriptor
+
+interface ModuleStructureOracle {
+    // May be faster than `findAllImplementingModules(module).isNotEmpty()`
+    fun hasImplementingModules(module: ModuleDescriptor): Boolean
+
+    fun findAllReversedDependsOnPaths(module: ModuleDescriptor): List<ModulePath>
+
+    fun findAllDependsOnPaths(module: ModuleDescriptor): List<ModulePath>
+
+    /**
+     * Works like all sources are effectively in one module.
+     *
+     * This is the mode CLI currently operates in.
+     */
+    object SingleModule : ModuleStructureOracle {
+        override fun hasImplementingModules(module: ModuleDescriptor): Boolean = false
+
+        override fun findAllReversedDependsOnPaths(module: ModuleDescriptor): List<ModulePath> = listOf(ModulePath(module))
+
+        override fun findAllDependsOnPaths(module: ModuleDescriptor): List<ModulePath> = listOf(ModulePath(module))
+    }
+}
+
+class ModulePath(val nodes: List<ModuleDescriptor>) {
+    constructor(vararg nodes: ModuleDescriptor) : this(nodes.toList())
+}