K2 scripting: add initial scripting support to K2 frontend

compiler/fir/semantics/src/org/jetbrains/kotlin/fir/declarations/ScriptScopes.kt

@@ -0,0 +1,33 @@
+/*
+ * Copyright 2010-2022 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.fir.declarations
+
+import org.jetbrains.kotlin.fir.labelName
+import org.jetbrains.kotlin.fir.resolve.SessionHolder
+import org.jetbrains.kotlin.fir.resolve.calls.ImplicitReceiverValueForScript
+import org.jetbrains.kotlin.fir.scopes.FirScope
+import org.jetbrains.kotlin.fir.scopes.impl.FirScriptDeclarationsScope
+import org.jetbrains.kotlin.fir.types.ConeKotlinType
+import org.jetbrains.kotlin.fir.types.coneType
+
+class TowerElementsForScript(
+    val implicitReceivers: List<ImplicitReceiverValueForScript>,
+    val staticScope: FirScope?,
+)
+
+fun SessionHolder.collectTowerDataElementsForScript(owner: FirScript): TowerElementsForScript {
+    val contextReceivers = owner.contextReceivers.mapIndexed { index, receiver ->
+        ImplicitReceiverValueForScript(
+            owner.symbol, receiver.typeRef.coneType, receiver.labelName, session, scopeSession,
+            contextReceiverNumber = index,
+        )
+    }
+
+    return TowerElementsForScript(
+        contextReceivers,
+        FirScriptDeclarationsScope(session, owner),
+    )
+}

compiler/fir/semantics/src/org/jetbrains/kotlin/fir/resolve/dfa/cfg/CFGNode.kt

@@ -303,6 +303,20 @@ class AnonymousObjectExpressionExitNode(owner: ControlFlowGraph, override val fi
     }
 }
 
+// ----------------------------------- Scripts ------------------------------------------
+
+class ScriptEnterNode(owner: ControlFlowGraph, override val fir: FirScript, level: Int, id: Int) : CFGNode<FirScript>(owner, level, id) {
+    override fun <R, D> accept(visitor: ControlFlowGraphVisitor<R, D>, data: D): R {
+        return visitor.visitScriptEnterNode(this, data)
+    }
+}
+
+class ScriptExitNode(owner: ControlFlowGraph, override val fir: FirScript, level: Int, id: Int) : CFGNode<FirScript>(owner, level, id) {
+    override fun <R, D> accept(visitor: ControlFlowGraphVisitor<R, D>, data: D): R {
+        return visitor.visitScriptExitNode(this, data)
+    }
+}
+
 // ----------------------------------- Initialization -----------------------------------
 
 class PartOfClassInitializationNode(owner: ControlFlowGraph, override val fir: FirControlFlowGraphOwner, level: Int, id: Int) : CFGNodeWithCfgOwner<FirControlFlowGraphOwner>(owner, level, id) {

compiler/fir/semantics/src/org/jetbrains/kotlin/fir/resolve/dfa/cfg/CFGNodeRenderer.kt

@@ -112,6 +112,9 @@ fun CFGNode<*>.render(): String =
                 is AnonymousObjectExitNode -> "Exit anonymous object"
                 is AnonymousObjectExpressionExitNode -> "Exit anonymous object expression"
 
+                is ScriptEnterNode -> "Enter class ${fir.name}"
+                is ScriptExitNode -> "Exit class ${fir.name}"
+
                 is ContractDescriptionEnterNode -> "Enter contract description"
 
                 is EnterDefaultArgumentsNode -> "Enter default value of ${fir.name}"

compiler/fir/semantics/src/org/jetbrains/kotlin/fir/resolve/dfa/cfg/ControlFlowGraphVisitor.kt

@@ -80,6 +80,16 @@ abstract class ControlFlowGraphVisitor<out R, in D> {
         return visitNode(node, data)
     }
 
+    // ----------------------------------- Scripts ------------------------------------------
+
+    open fun visitScriptEnterNode(node: ScriptEnterNode, data: D): R {
+        return visitNode(node, data)
+    }
+
+    open fun visitScriptExitNode(node: ScriptExitNode, data: D): R {
+        return visitNode(node, data)
+    }
+
     // ----------------------------------- Initialization -----------------------------------
 
     open fun visitPartOfClassInitializationNode(node: PartOfClassInitializationNode, data: D): R {