[FIR IDE] LC Add KtFileSymbol and fix facade annotations

idea/idea-frontend-api/src/org/jetbrains/kotlin/idea/frontend/api/KtAnalysisSession.kt

@@ -121,6 +121,8 @@ abstract class KtAnalysisSession(final override val token: ValidityToken) : Vali
 
     fun KtPropertyAccessor.getPropertyAccessorSymbol(): KtPropertyAccessorSymbol = symbolProvider.getPropertyAccessorSymbol(this)
 
+    fun KtFile.getFileSymbol(): KtFileSymbol = symbolProvider.getFileSymbol(this)
+
     /**
      * @return symbol with specified [this@getClassOrObjectSymbolByClassId] or `null` in case such symbol is not found
      */

idea/idea-frontend-api/src/org/jetbrains/kotlin/idea/frontend/api/symbols/KtFileSymbol.kt

@@ -0,0 +1,13 @@
+/*
+ * Copyright 2010-2020 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.idea.frontend.api.symbols
+
+import org.jetbrains.kotlin.idea.frontend.api.symbols.markers.KtAnnotatedSymbol
+import org.jetbrains.kotlin.idea.frontend.api.symbols.pointers.KtSymbolPointer
+
+abstract class KtFileSymbol : KtAnnotatedSymbol {
+    abstract override fun createPointer(): KtSymbolPointer<KtFileSymbol>
+}

idea/idea-frontend-api/src/org/jetbrains/kotlin/idea/frontend/api/symbols/KtSymbolProvider.kt

@@ -30,6 +30,7 @@ abstract class KtSymbolProvider : KtAnalysisSessionComponent() {
     }
 
     abstract fun getParameterSymbol(psi: KtParameter): KtParameterSymbol
+    abstract fun getFileSymbol(psi: KtFile): KtFileSymbol
     abstract fun getFunctionSymbol(psi: KtNamedFunction): KtFunctionSymbol
     abstract fun getConstructorSymbol(psi: KtConstructor<*>): KtConstructorSymbol
     abstract fun getTypeParameterSymbol(psi: KtTypeParameter): KtTypeParameterSymbol

idea/idea-frontend-fir/src/org/jetbrains/kotlin/idea/asJava/annotations/annotationsUtils.kt

@@ -16,6 +16,7 @@ import org.jetbrains.kotlin.fir.expressions.*
 import org.jetbrains.kotlin.fir.references.FirNamedReference
 import org.jetbrains.kotlin.idea.frontend.api.fir.symbols.KtFirSymbol
 import org.jetbrains.kotlin.idea.frontend.api.fir.utils.mapAnnotationParameters
+import org.jetbrains.kotlin.idea.frontend.api.symbols.KtFileSymbol
 import org.jetbrains.kotlin.idea.frontend.api.symbols.KtPropertySymbol
 import org.jetbrains.kotlin.idea.frontend.api.symbols.markers.KtAnnotatedSymbol
 import org.jetbrains.kotlin.idea.frontend.api.symbols.markers.KtSimpleConstantValue
@@ -24,6 +25,9 @@ import org.jetbrains.kotlin.psi.KtFile
 internal fun KtAnnotatedSymbol.hasJvmSyntheticAnnotation(annotationUseSiteTarget: AnnotationUseSiteTarget? = null): Boolean =
     hasAnnotation("kotlin/jvm/JvmSynthetic", annotationUseSiteTarget)
 
+internal fun KtFileSymbol.hasJvmMultifileClassAnnotation(): Boolean =
+    hasAnnotation("kotlin/jvm/JvmMultifileClass", AnnotationUseSiteTarget.FILE)
+
 internal fun KtAnnotatedSymbol.getJvmNameFromAnnotation(annotationUseSiteTarget: AnnotationUseSiteTarget? = null): String? {
     val annotation = annotations.firstOrNull {
         val siteTarget = it.useSiteTarget
@@ -121,10 +125,3 @@ internal fun KtAnnotatedSymbol.computeAnnotations(
 
     return result
 }
-
-internal fun KtFile.hasJvmMultifileClassAnnotation(): Boolean = this.annotationEntries
-    .filter {
-        it.useSiteTarget?.getAnnotationUseSiteTarget() == AnnotationUseSiteTarget.FILE
-    }.any {
-        it.shortName?.asString() == "JvmMultifileClass"
-    }

idea/idea-frontend-fir/src/org/jetbrains/kotlin/idea/asJava/classes/FirLightClassForFacade.kt

@@ -20,6 +20,7 @@ import org.jetbrains.kotlin.asJava.classes.lazyPub
 import org.jetbrains.kotlin.asJava.elements.FakeFileForLightClass
 import org.jetbrains.kotlin.asJava.elements.KtLightField
 import org.jetbrains.kotlin.asJava.elements.KtLightMethod
+import org.jetbrains.kotlin.descriptors.annotations.AnnotationUseSiteTarget
 import org.jetbrains.kotlin.idea.KotlinLanguage
 import org.jetbrains.kotlin.idea.asJava.classes.createField
 import org.jetbrains.kotlin.idea.asJava.classes.createMethods
@@ -51,14 +52,28 @@ class FirLightClassForFacade(
 
     override val clsDelegate: PsiClass get() = invalidAccess()
 
+    private val fileSymbols by lazyPub {
+        files.map { ktFile ->
+            analyze(ktFile) {
+                ktFile.getFileSymbol()
+            }
+        }
+    }
+
     private val _modifierList: PsiModifierList by lazyPub {
         if (multiFileClass)
             return@lazyPub LightModifierList(manager, KotlinLanguage.INSTANCE, PsiModifier.PUBLIC, PsiModifier.FINAL)
 
         val modifiers = setOf(PsiModifier.PUBLIC, PsiModifier.FINAL)
 
-        //TODO make annotations for file site
+        val annotations = fileSymbols.flatMap {
-        val annotations: List<PsiAnnotation> = emptyList()
+            it.computeAnnotations(
+                this@FirLightClassForFacade,
+                NullabilityType.Unknown,
+                AnnotationUseSiteTarget.FILE,
+                includeAnnotationsWithoutSite = false
+            )
+        }
 
         FirLightClassModifierList(this@FirLightClassForFacade, modifiers, annotations)
     }
@@ -95,7 +110,7 @@ class FirLightClassForFacade(
     }
 
     private val multiFileClass: Boolean by lazyPub {
-        files.size > 1 || files.any { it.hasJvmMultifileClassAnnotation() }
+        files.size > 1 || fileSymbols.any { it.hasJvmMultifileClassAnnotation() }
     }
 
     private fun loadFieldsFromFile(

idea/idea-frontend-fir/src/org/jetbrains/kotlin/idea/frontend/api/fir/KtSymbolByFirBuilder.kt

@@ -40,6 +40,7 @@ internal class KtSymbolByFirBuilder private constructor(
     override val token: ValidityToken,
     val withReadOnlyCaching: Boolean,
     private val symbolsCache: BuilderCache<FirDeclaration, KtSymbol>,
+    private val filesCache: BuilderCache<FirFile, KtFileSymbol>,
     private val typesCache: BuilderCache<ConeKotlinType, KtType>
 ) : ValidityTokenOwner {
     private val resolveState by weakRef(resolveState)
@@ -56,7 +57,8 @@ internal class KtSymbolByFirBuilder private constructor(
         resolveState = resolveState,
         withReadOnlyCaching = false,
         symbolsCache = BuilderCache(),
-        typesCache = BuilderCache()
+        typesCache = BuilderCache(),
+        filesCache = BuilderCache(),
     )
 
 
@@ -68,7 +70,8 @@ internal class KtSymbolByFirBuilder private constructor(
             resolveState = newResolveState,
             withReadOnlyCaching = true,
             symbolsCache = symbolsCache.createReadOnlyCopy(),
-            typesCache = typesCache.createReadOnlyCopy()
+            typesCache = typesCache.createReadOnlyCopy(),
+            filesCache = filesCache.createReadOnlyCopy(),
         )
     }
 
@@ -139,6 +142,8 @@ internal class KtSymbolByFirBuilder private constructor(
     fun buildAnonymousFunctionSymbol(fir: FirAnonymousFunction) =
         symbolsCache.cache(fir) { KtFirAnonymousFunctionSymbol(fir, resolveState, token, this) }
 
+    fun buildFileSymbol(fir: FirFile) = filesCache.cache(fir) { KtFirFileSymbol(fir, resolveState, token, this) }
+
     fun buildVariableSymbol(fir: FirProperty): KtVariableSymbol = symbolsCache.cache(fir) {
         when {
             fir.isLocal -> KtFirLocalVariableSymbol(fir, resolveState, token, this)

idea/idea-frontend-fir/src/org/jetbrains/kotlin/idea/frontend/api/fir/symbols/KtFirFileSymbol.kt

@@ -0,0 +1,40 @@
+/*
+ * Copyright 2010-2020 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.idea.frontend.api.fir.symbols
+
+import com.intellij.psi.PsiElement
+import org.jetbrains.kotlin.fir.declarations.FirFile
+import org.jetbrains.kotlin.fir.declarations.FirResolvePhase
+import org.jetbrains.kotlin.idea.fir.findPsi
+import org.jetbrains.kotlin.idea.fir.low.level.api.api.FirModuleResolveState
+import org.jetbrains.kotlin.idea.frontend.api.ValidityToken
+import org.jetbrains.kotlin.idea.frontend.api.fir.KtSymbolByFirBuilder
+import org.jetbrains.kotlin.idea.frontend.api.fir.utils.convertAnnotation
+import org.jetbrains.kotlin.idea.frontend.api.fir.utils.firRef
+import org.jetbrains.kotlin.idea.frontend.api.symbols.KtFileSymbol
+import org.jetbrains.kotlin.idea.frontend.api.symbols.markers.KtAnnotationCall
+import org.jetbrains.kotlin.idea.frontend.api.symbols.pointers.KtPsiBasedSymbolPointer
+import org.jetbrains.kotlin.idea.frontend.api.symbols.pointers.KtSymbolPointer
+
+internal class KtFirFileSymbol(
+    fir: FirFile,
+    resolveState: FirModuleResolveState,
+    override val token: ValidityToken,
+    private val builder: KtSymbolByFirBuilder
+) : KtFileSymbol(), KtFirSymbol<FirFile> {
+
+    override val firRef = firRef(fir, resolveState)
+    override val psi: PsiElement? by firRef.withFirAndCache {  fir -> fir.findPsi(fir.session) }
+
+    override fun createPointer(): KtSymbolPointer<KtFileSymbol> {
+        KtPsiBasedSymbolPointer.createForSymbolFromSource(this)?.let { return it }
+        TODO("Creating pointers for files from library is not supported yet")
+    }
+
+    override val annotations: List<KtAnnotationCall> by firRef.withFirAndCache(FirResolvePhase.TYPES) {
+        convertAnnotation(it)
+    }
+}

idea/idea-frontend-fir/src/org/jetbrains/kotlin/idea/frontend/api/fir/symbols/KtFirSymbolProvider.kt

@@ -9,6 +9,7 @@ import org.jetbrains.kotlin.fir.declarations.*
 import org.jetbrains.kotlin.fir.resolve.providers.FirSymbolProvider
 import org.jetbrains.kotlin.fir.symbols.impl.FirRegularClassSymbol
 import org.jetbrains.kotlin.idea.fir.low.level.api.api.FirModuleResolveState
+import org.jetbrains.kotlin.idea.fir.low.level.api.api.getFirFile
 import org.jetbrains.kotlin.idea.fir.low.level.api.api.getOrBuildFirOfType
 import org.jetbrains.kotlin.idea.fir.low.level.api.api.withFirDeclarationOfType
 import org.jetbrains.kotlin.idea.frontend.api.KtAnalysisSession
@@ -38,6 +39,10 @@ internal class KtFirSymbolProvider(
         }
     }
 
+    override fun getFileSymbol(psi: KtFile): KtFileSymbol = withValidityAssertion {
+        firSymbolBuilder.buildFileSymbol(psi.getFirFile(resolveState))
+    }
+
     override fun getFunctionSymbol(psi: KtNamedFunction): KtFunctionSymbol = withValidityAssertion {
         psi.withFirDeclarationOfType<FirSimpleFunction, KtFunctionSymbol>(resolveState) {
             firSymbolBuilder.buildFunctionSymbol(it)