FIR IDE: Add KtCallableSymbol abstraction

- It should incapsulate callable symbols like functions, properties
and constructors

Co-authored-by: Ilya Kirillov <ilya.kirillov@jetbrains.com>

idea/idea-frontend-api/src/org/jetbrains/kotlin/idea/frontend/api/scopes/KtScope.kt

@@ -16,7 +16,7 @@ interface KtScope : ValidityOwner {
 
 
     fun getAllSymbols(): Sequence<KtSymbol>
-    fun getCallableSymbols(): Sequence<KtSymbol>
+    fun getCallableSymbols(): Sequence<KtCallableSymbol>
     fun getClassClassLikeSymbols(): Sequence<KtClassLikeSymbol>
 
     fun containsName(name: Name): Boolean

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

@@ -0,0 +1,8 @@
+/*
+ * 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
+
+abstract class KtCallableSymbol : KtSymbol

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

@@ -7,7 +7,7 @@ package org.jetbrains.kotlin.idea.frontend.api.symbols
 
 import org.jetbrains.kotlin.name.FqName
 
-sealed class KtFunctionLikeSymbol : KtTypedSymbol, KtSymbolWithKind {
+sealed class KtFunctionLikeSymbol : KtCallableSymbol(), KtTypedSymbol, KtSymbolWithKind {
     abstract val valueParameters: List<KtParameterSymbol>
 }
 

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

@@ -7,7 +7,7 @@ package org.jetbrains.kotlin.idea.frontend.api.symbols
 
 import org.jetbrains.kotlin.name.FqName
 
-abstract class KtVariableLikeSymbol : KtTypedSymbol, KtNamedSymbol, KtSymbolWithKind
+abstract class KtVariableLikeSymbol : KtCallableSymbol(), KtTypedSymbol, KtNamedSymbol, KtSymbolWithKind
 
 abstract class KtEnumEntrySymbol : KtVariableLikeSymbol() {
     final override val symbolKind: KtSymbolKind get() = KtSymbolKind.MEMBER

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

@@ -29,6 +29,9 @@ interface KtPossibleExtensionSymbol {
     val receiverType: KtType?
 }
 
+val KtCallableSymbol.isExtension: Boolean
+    get() = (this as? KtPossibleExtensionSymbol)?.isExtension == true
+
 interface KtSymbolWithTypeParameters {
     val typeParameters: List<KtTypeParameterSymbol>
 }

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

@@ -32,10 +32,7 @@ import org.jetbrains.kotlin.idea.frontend.api.fir.types.KtFirIntersectionType
 import org.jetbrains.kotlin.idea.frontend.api.fir.types.KtFirTypeArgumentWithVariance
 import org.jetbrains.kotlin.idea.frontend.api.fir.types.KtFirTypeParameterType
 import org.jetbrains.kotlin.idea.frontend.api.fir.utils.weakRef
-import org.jetbrains.kotlin.idea.frontend.api.symbols.KtClassLikeSymbol
+import org.jetbrains.kotlin.idea.frontend.api.symbols.*
-import org.jetbrains.kotlin.idea.frontend.api.symbols.KtSymbol
-import org.jetbrains.kotlin.idea.frontend.api.symbols.KtTypeParameterSymbol
-import org.jetbrains.kotlin.idea.frontend.api.symbols.KtVariableSymbol
 import org.jetbrains.kotlin.idea.frontend.api.types.KtType
 import org.jetbrains.kotlin.idea.stubindex.PackageIndexUtil
 import org.jetbrains.kotlin.name.FqName
@@ -72,6 +69,9 @@ internal class KtSymbolByFirBuilder(
         }
     }
 
+    // TODO Handle all relevant cases
+    fun buildCallableSymbol(fir: FirCallableDeclaration<*>): KtCallableSymbol = buildSymbol(fir) as KtCallableSymbol
+
     fun buildClassLikeSymbol(fir: FirClassLikeDeclaration<*>): KtClassLikeSymbol = when (fir) {
         is FirRegularClass -> buildClassSymbol(fir)
         is FirTypeAlias -> buildTypeAliasSymbol(fir)

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

@@ -9,6 +9,7 @@ import org.jetbrains.kotlin.idea.frontend.api.ValidityOwner
 import org.jetbrains.kotlin.idea.frontend.api.ValidityOwnerByValidityToken
 import org.jetbrains.kotlin.idea.frontend.api.scopes.KtCompositeScope
 import org.jetbrains.kotlin.idea.frontend.api.scopes.KtScope
+import org.jetbrains.kotlin.idea.frontend.api.symbols.KtCallableSymbol
 import org.jetbrains.kotlin.idea.frontend.api.symbols.KtClassLikeSymbol
 import org.jetbrains.kotlin.idea.frontend.api.symbols.KtSymbol
 import org.jetbrains.kotlin.idea.frontend.api.withValidityAssertion
@@ -45,7 +46,7 @@ class KtFirCompositeScope(
         }
     }
 
-    override fun getCallableSymbols(): Sequence<KtSymbol> = withValidityAssertion {
+    override fun getCallableSymbols(): Sequence<KtCallableSymbol> = withValidityAssertion {
         sequence {
             subScopes.forEach { yieldAll(it.getCallableSymbols()) }
         }

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

@@ -16,6 +16,7 @@ import org.jetbrains.kotlin.fir.symbols.PossiblyFirFakeOverrideSymbol
 import org.jetbrains.kotlin.fir.symbols.impl.FirPropertySymbol
 import org.jetbrains.kotlin.idea.frontend.api.fir.KtSymbolByFirBuilder
 import org.jetbrains.kotlin.idea.frontend.api.scopes.KtScope
+import org.jetbrains.kotlin.idea.frontend.api.symbols.KtCallableSymbol
 import org.jetbrains.kotlin.idea.frontend.api.symbols.KtClassLikeSymbol
 import org.jetbrains.kotlin.idea.frontend.api.symbols.KtSymbol
 import org.jetbrains.kotlin.idea.frontend.api.withValidityAssertion
@@ -48,10 +49,10 @@ internal abstract class KtFirDelegatingScope(private val builder: KtSymbolByFirB
         }
     }
 
-    override fun getCallableSymbols(): Sequence<KtSymbol> = withValidityAssertion {
+    override fun getCallableSymbols(): Sequence<KtCallableSymbol> = withValidityAssertion {
         sequence {
             firScope.getCallableNames().forEach { name ->
-                val callables = mutableListOf<KtSymbol>()
+                val callables = mutableListOf<KtCallableSymbol>()
                 firScope.processFunctionsByName(name) { firSymbol ->
                     (firSymbol.fir as? FirSimpleFunction)?.let { fir ->
                         callables.add(builder.buildFunctionSymbol(fir, firSymbol.realDeclarationOrigin()))
@@ -62,7 +63,7 @@ internal abstract class KtFirDelegatingScope(private val builder: KtSymbolByFirB
                         firSymbol is FirPropertySymbol && firSymbol.isFakeOverride -> {
                             builder.buildVariableSymbol(firSymbol.fir, firSymbol.realDeclarationOrigin())
                         }
-                        else -> builder.buildSymbol(firSymbol.fir)
+                        else -> builder.buildCallableSymbol(firSymbol.fir)
                     }
                     callables.add(symbol)
                 }