[AA] Add expectForActual

#KT-54864

Merge-request: KT-MR-8222
Merged-by: Vladimir Dolzhenko <Vladimir.Dolzhenko@jetbrains.com>

analysis/analysis-api/src/org/jetbrains/kotlin/analysis/api/KtAnalysisSession.kt

@@ -54,6 +54,7 @@ public abstract class KtAnalysisSession(final override val token: KtLifetimeToke
     KtSymbolDeclarationRendererMixIn,
     KtVisibilityCheckerMixIn,
     KtMemberSymbolProviderMixin,
+    KtMultiplatformInfoProviderMixin,
     KtInheritorsProviderMixIn,
     KtTypeCreatorMixIn,
     KtAnalysisScopeProviderMixIn,
@@ -136,6 +137,9 @@ public abstract class KtAnalysisSession(final override val token: KtLifetimeToke
     internal val inheritorsProvider: KtInheritorsProvider get() = inheritorsProviderImpl
     protected abstract val inheritorsProviderImpl: KtInheritorsProvider
 
+    internal val multiplatformInfoProvider: KtMultiplatformInfoProvider get() = multiplatformInfoProviderImpl
+    protected abstract val multiplatformInfoProviderImpl: KtMultiplatformInfoProvider
+
     internal val symbolInfoProvider: KtSymbolInfoProvider get() = symbolInfoProviderImpl
     protected abstract val symbolInfoProviderImpl: KtSymbolInfoProvider
 

analysis/analysis-api/src/org/jetbrains/kotlin/analysis/api/components/KtMultiplatformInfoProvider.kt

@@ -0,0 +1,23 @@
+/*
+ * Copyright 2010-2023 JetBrains s.r.o. and Kotlin Programming Language contributors.
+ * 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.analysis.api.components
+
+import org.jetbrains.kotlin.analysis.api.lifetime.withValidityAssertion
+import org.jetbrains.kotlin.analysis.api.symbols.KtDeclarationSymbol
+
+public abstract class KtMultiplatformInfoProvider : KtAnalysisSessionComponent() {
+    public abstract fun getExpectForActual(actual: KtDeclarationSymbol): KtDeclarationSymbol?
+}
+
+public interface KtMultiplatformInfoProviderMixin : KtAnalysisSessionMixIn {
+
+    /**
+     * Gives expect symbol for the actual one if it is available.
+     **/
+    public fun KtDeclarationSymbol.getExpectForActual(): KtDeclarationSymbol? =
+        withValidityAssertion { analysisSession.multiplatformInfoProvider.getExpectForActual(this) }
+
+}

analysis/analysis-api/src/org/jetbrains/kotlin/analysis/api/symbols/KtDeclarationSymbol.kt

@@ -10,6 +10,6 @@ import org.jetbrains.kotlin.analysis.api.symbols.markers.KtSymbolWithTypeParamet
 
 /**
  * Represents a symbol of declaration which can be directly expressed in source code.
- * Eg, classes, type parameters or functions ar [KtDeclarationSymbol], but files and packages are not
+ * Eg, classes, type parameters or functions are [KtDeclarationSymbol], but files and packages are not
  */
 public sealed interface KtDeclarationSymbol : KtSymbol, KtSymbolWithTypeParameters, KtAnnotatedSymbol

analysis/analysis-api/testData/components/multiplatformInfoProvider/expectForActual/actual_object.descriptors.txt

@@ -0,0 +1 @@
+expected symbol: null

analysis/analysis-api/testData/components/multiplatformInfoProvider/expectForActual/actual_object.kt

@@ -0,0 +1,16 @@
+// !LANGUAGE: +MultiPlatformProjects
+// MODULE: commonMain
+// FILE: Common.kt
+
+package sample
+expect object Platform {
+    val name: String
+}
+
+// MODULE: androidMain(commonMain)
+// FILE: JvmAndroid.kt
+
+package sample
+actual object <caret>Platform {
+    actual val name: String = "JVM"
+}

analysis/analysis-api/testData/components/multiplatformInfoProvider/expectForActual/actual_object.txt

@@ -0,0 +1 @@
+expected symbol: Common.kt : object Platform