[IR][JS][Wasm] Use unified lowering to remove expect declarations

ExpectDeclarationsRemoveLowering uses an overkill method to remove expect declarations: 
it transforms declarations with ExpectDeclarationRemover(symbolTable, doRemove=true).
In contrast, Native version of this removing, ExpectDeclarationsRemoving, uses simplest way to remove top-level declarations.
In this MR, this approach is used for all Klib backends.

^KT-73063 Fixed

Merge-request: KT-MR-19026
Merged-by: Vladimir Sukharev <Vladimir.Sukharev@jetbrains.com>

compiler/ir/backend.common/src/org/jetbrains/kotlin/backend/common/lower/ExpectDeclarationsRemoveLowering.kt

@@ -5,17 +5,29 @@
 
 package org.jetbrains.kotlin.backend.common.lower
 
-import org.jetbrains.kotlin.backend.common.DeclarationTransformer
-import org.jetbrains.kotlin.ir.declarations.IrDeclaration
-import org.jetbrains.kotlin.ir.util.ReferenceSymbolTable
+import org.jetbrains.kotlin.backend.common.FileLoweringPass
+import org.jetbrains.kotlin.backend.common.LoweringContext
+import org.jetbrains.kotlin.ir.declarations.*
 
 /**
- * This pass removes all declarations with `isExpect == true`.
+ * This pass removes all declarations with `isExpect == true`, which usually come as unactualized optional expectations, like
+ * - when compiling Native stdlib cache: the following comes from `libraries/stdlib/common/src/kotlin/JsAnnotationsH.kt`
+ *      @OptionalExpectation public expect annotation class JsName(val name: String)
+ * - when compiling WASM: the following comes from `libraries/stdlib/common/src/kotlin/JsAnnotationsH.kt`
+ *      @OptionalExpectation public expect annotation class JsFileName(val name: String)
+ * - when compiling JS: the following comes from `libraries/stdlib/common/src/kotlin/JvmAnnotationsH.kt`
+ *      @OptionalExpectation public expect annotation class JvmMultifileClass()
  */
-class ExpectDeclarationsRemoveLowering(symbolTable: ReferenceSymbolTable) : DeclarationTransformer {
-    private val remover = ExpectDeclarationRemover(symbolTable, true)
-
-    override fun transformFlat(declaration: IrDeclaration): List<IrDeclaration>? {
-        return remover.transformFlat(declaration)
+class ExpectDeclarationsRemoveLowering(val context: LoweringContext) : FileLoweringPass {
+    override fun lower(irFile: IrFile) {
+        // All declarations with `isExpect == true` are nested into a top-level declaration with `isExpect == true`.
+        irFile.declarations.removeAll {
+            when (it) {
+                is IrClass -> it.isExpect
+                is IrFunction -> it.isExpect
+                is IrProperty -> it.isExpect
+                else -> false
+            }
+        }
     }
 }

compiler/ir/backend.js/src/org/jetbrains/kotlin/ir/backend/js/JsLoweringPhases.kt

@@ -135,9 +135,7 @@ private val annotationInstantiationLowering = makeIrModulePhase(
 )
 
 private val expectDeclarationsRemovingPhase = makeIrModulePhase(
-    { context: JsIrBackendContext ->
-        ExpectDeclarationsRemoveLowering(context.symbolTable)
-    },
+    ::ExpectDeclarationsRemoveLowering,
     name = "ExpectDeclarationsRemoving",
 )
 

compiler/ir/backend.wasm/src/org/jetbrains/kotlin/backend/wasm/WasmLoweringPhases.kt

@@ -51,9 +51,7 @@ private val generateTestsIC = makeIrModulePhase(
 )
 
 private val expectDeclarationsRemovingPhase = makeIrModulePhase(
-    { context: WasmBackendContext ->
-        ExpectDeclarationsRemoveLowering(context.symbolTable)
-    },
+    ::ExpectDeclarationsRemoveLowering,
     name = "ExpectDeclarationsRemoving",
 )
 

kotlin-native/backend.native/compiler/ir/backend.native/src/org/jetbrains/kotlin/backend/konan/driver/phases/NativeLoweringPhases.kt

@@ -128,7 +128,7 @@ internal val functionsWithoutBoundCheck = createSimpleNamedCompilerPhase<Context
 )
 
 private val removeExpectDeclarationsPhase = createFileLoweringPhase(
-        ::ExpectDeclarationsRemoving,
+        ::ExpectDeclarationsRemoveLowering,
         name = "RemoveExpectDeclarations",
 )
 

kotlin-native/backend.native/compiler/ir/backend.native/src/org/jetbrains/kotlin/backend/konan/lower/ExpectDeclarationsRemoving.kt → kotlin-native/backend.native/compiler/ir/backend.native/src/org/jetbrains/kotlin/backend/konan/lower/ExpectToActualDefaultValueCopier.kt

@@ -5,8 +5,6 @@
 
 package org.jetbrains.kotlin.backend.konan.lower
 
-import org.jetbrains.kotlin.backend.common.FileLoweringPass
-import org.jetbrains.kotlin.backend.konan.Context
 import org.jetbrains.kotlin.backend.konan.descriptors.isExpectMember
 import org.jetbrains.kotlin.backend.konan.descriptors.propertyIfAccessor
 import org.jetbrains.kotlin.backend.konan.ir.ModuleIndex
@@ -28,24 +26,6 @@ import org.jetbrains.kotlin.resolve.descriptorUtil.module
 import org.jetbrains.kotlin.resolve.multiplatform.OptionalAnnotationUtil
 import org.jetbrains.kotlin.resolve.multiplatform.findCompatibleActualsForExpected
 
-/**
- * This pass removes all declarations with `isExpect == true`.
- * Note: org.jetbrains.kotlin.backend.common.lower.ExpectDeclarationsRemoving is copy of this lower.
- */
-internal class ExpectDeclarationsRemoving(val context: Context) : FileLoweringPass {
-    override fun lower(irFile: IrFile) {
-        // All declarations with `isExpect == true` are nested into a top-level declaration with `isExpect == true`.
-        irFile.declarations.removeAll {
-            when (it) {
-                is IrClass -> it.isExpect
-                is IrFunction -> it.isExpect
-                is IrProperty -> it.isExpect
-                else -> false
-            }
-        }
-    }
-}
-
 @OptIn(ObsoleteDescriptorBasedAPI::class)
 internal class ExpectToActualDefaultValueCopier(private val irModule: IrModuleFragment, private val irBuiltIns: IrBuiltIns) {