[FIR2IR] Use signature composer to read external callables

compiler/fir/fir2ir/src/org/jetbrains/kotlin/fir/backend/Fir2IrDeclarationStorage.kt

@@ -874,6 +874,11 @@ class Fir2IrDeclarationStorage(
             is FirSimpleFunction, is FirAnonymousFunction -> {
                 getCachedIrFunction(firDeclaration)?.let { return it.symbol }
                 val irParent = findIrParent(firDeclaration)
+                symbolTable.referenceSimpleFunctionIfAny(signatureComposer.composeSignature(firDeclaration))?.let { irFunctionSymbol ->
+                    val irFunction = irFunctionSymbol.owner
+                    functionCache[firDeclaration] = irFunction
+                    return irFunctionSymbol
+                }
                 val parentOrigin = (irParent as? IrDeclaration)?.origin ?: IrDeclarationOrigin.DEFINED
                 createIrFunction(firDeclaration, irParent, origin = parentOrigin).apply {
                     setAndModifyParent(irParent)
@@ -891,6 +896,11 @@ class Fir2IrDeclarationStorage(
             is FirProperty -> {
                 propertyCache[fir]?.let { return it.symbol }
                 val irParent = findIrParent(fir)
+                symbolTable.referencePropertyIfAny(signatureComposer.composeSignature(fir))?.let { irPropertySymbol ->
+                    val irProperty = irPropertySymbol.owner
+                    propertyCache[fir] = irProperty
+                    return irPropertySymbol
+                }
                 val parentOrigin = (irParent as? IrDeclaration)?.origin ?: IrDeclarationOrigin.DEFINED
                 createIrProperty(fir, irParent, origin = parentOrigin).apply {
                     setAndModifyParent(irParent)

compiler/ir/ir.tree/src/org/jetbrains/kotlin/ir/util/SymbolTable.kt

@@ -633,6 +633,9 @@ open class SymbolTable(
     override fun referenceProperty(descriptor: PropertyDescriptor): IrPropertySymbol =
         propertySymbolTable.referenced(descriptor) { createPropertySymbol(descriptor) }
 
+    fun referencePropertyIfAny(sig: IdSignature): IrPropertySymbol? =
+        propertySymbolTable.get(sig)
+
     override fun referencePropertyFromLinker(descriptor: PropertyDescriptor, sig: IdSignature): IrPropertySymbol =
         propertySymbolTable.run {
             if (sig.isPublic) referenced(sig) { IrPropertyPublicSymbolImpl(descriptor, sig) }
@@ -718,6 +721,9 @@ open class SymbolTable(
     override fun referenceSimpleFunction(descriptor: FunctionDescriptor) =
         simpleFunctionSymbolTable.referenced(descriptor) { createSimpleFunctionSymbol(descriptor) }
 
+    fun referenceSimpleFunctionIfAny(sig: IdSignature): IrSimpleFunctionSymbol? =
+        simpleFunctionSymbolTable.get(sig)
+
     override fun referenceSimpleFunctionFromLinker(descriptor: FunctionDescriptor, sig: IdSignature): IrSimpleFunctionSymbol {
         return simpleFunctionSymbolTable.run {
             if (sig.isPublic) referenced(sig) { IrSimpleFunctionPublicSymbolImpl(descriptor, sig) } else

compiler/testData/ir/irText/types/nullChecks/enhancedNullabilityInForLoop.fir.txt

@@ -6,27 +6,27 @@ FILE fqName:<root> fileName:/enhancedNullabilityInForLoop.kt
     BLOCK_BODY
       BLOCK type=kotlin.Unit origin=FOR_LOOP
         VAR FOR_LOOP_ITERATOR name:tmp_0 type:kotlin.collections.MutableIterator<<root>.P?> [val]
-          CALL 'public abstract fun iterator (): kotlin.collections.MutableIterator<E of kotlin.collections.MutableList> [operator] declared in kotlin.collections.MutableList' type=kotlin.collections.MutableIterator<<root>.P?> origin=FOR_LOOP_ITERATOR
+          CALL 'public abstract fun iterator (): kotlin.collections.MutableIterator<E of kotlin.collections.MutableList> [fake_override,operator] declared in kotlin.collections.MutableList' type=kotlin.collections.MutableIterator<<root>.P?> origin=FOR_LOOP_ITERATOR
             $this: CALL 'public open fun listOfNotNull (): kotlin.collections.List<<root>.P?>? declared in <root>.J' type=kotlin.collections.List<<root>.P?>? origin=null
         WHILE label=null origin=FOR_LOOP_INNER_WHILE
           condition: CALL 'public abstract fun hasNext (): kotlin.Boolean [operator] declared in kotlin.collections.Iterator' type=kotlin.Boolean origin=FOR_LOOP_HAS_NEXT
             $this: GET_VAR 'val tmp_0: kotlin.collections.MutableIterator<<root>.P?> [val] declared in <root>.testForInListUnused' type=kotlin.collections.MutableIterator<<root>.P?> origin=null
           body: BLOCK type=kotlin.Unit origin=FOR_LOOP_INNER_WHILE
             VAR FOR_LOOP_VARIABLE name:x type:<root>.P? [val]
-              CALL 'public abstract fun next (): T of kotlin.collections.MutableIterator [operator] declared in kotlin.collections.MutableIterator' type=<root>.P? origin=FOR_LOOP_NEXT
+              CALL 'public abstract fun next (): T of kotlin.collections.MutableIterator [fake_override,operator] declared in kotlin.collections.MutableIterator' type=<root>.P? origin=FOR_LOOP_NEXT
                 $this: GET_VAR 'val tmp_0: kotlin.collections.MutableIterator<<root>.P?> [val] declared in <root>.testForInListUnused' type=kotlin.collections.MutableIterator<<root>.P?> origin=null
   FUN name:testForInListDestructured visibility:public modality:FINAL <> () returnType:kotlin.Unit
     BLOCK_BODY
       BLOCK type=kotlin.Unit origin=FOR_LOOP
         VAR FOR_LOOP_ITERATOR name:tmp_1 type:kotlin.collections.MutableIterator<<root>.P?> [val]
-          CALL 'public abstract fun iterator (): kotlin.collections.MutableIterator<E of kotlin.collections.MutableList> [operator] declared in kotlin.collections.MutableList' type=kotlin.collections.MutableIterator<<root>.P?> origin=FOR_LOOP_ITERATOR
+          CALL 'public abstract fun iterator (): kotlin.collections.MutableIterator<E of kotlin.collections.MutableList> [fake_override,operator] declared in kotlin.collections.MutableList' type=kotlin.collections.MutableIterator<<root>.P?> origin=FOR_LOOP_ITERATOR
             $this: CALL 'public open fun listOfNotNull (): kotlin.collections.List<<root>.P?>? declared in <root>.J' type=kotlin.collections.List<<root>.P?>? origin=null
         WHILE label=null origin=FOR_LOOP_INNER_WHILE
           condition: CALL 'public abstract fun hasNext (): kotlin.Boolean [operator] declared in kotlin.collections.Iterator' type=kotlin.Boolean origin=FOR_LOOP_HAS_NEXT
             $this: GET_VAR 'val tmp_1: kotlin.collections.MutableIterator<<root>.P?> [val] declared in <root>.testForInListDestructured' type=kotlin.collections.MutableIterator<<root>.P?> origin=null
           body: BLOCK type=kotlin.Unit origin=FOR_LOOP_INNER_WHILE
             VAR FOR_LOOP_VARIABLE name:<destruct> type:<root>.P? [val]
-              CALL 'public abstract fun next (): T of kotlin.collections.MutableIterator [operator] declared in kotlin.collections.MutableIterator' type=<root>.P? origin=FOR_LOOP_NEXT
+              CALL 'public abstract fun next (): T of kotlin.collections.MutableIterator [fake_override,operator] declared in kotlin.collections.MutableIterator' type=<root>.P? origin=FOR_LOOP_NEXT
                 $this: GET_VAR 'val tmp_1: kotlin.collections.MutableIterator<<root>.P?> [val] declared in <root>.testForInListDestructured' type=kotlin.collections.MutableIterator<<root>.P?> origin=null
             VAR name:x type:kotlin.Int [val]
               CALL 'public final fun component1 (): kotlin.Int declared in <root>.P' type=kotlin.Int origin=null
@@ -37,14 +37,14 @@ FILE fqName:<root> fileName:/enhancedNullabilityInForLoop.kt
   FUN name:testDesugaredForInList visibility:public modality:FINAL <> () returnType:kotlin.Unit
     BLOCK_BODY
       VAR name:iterator type:kotlin.collections.MutableIterator<<root>.P?> [val]
-        CALL 'public abstract fun iterator (): kotlin.collections.MutableIterator<E of kotlin.collections.MutableList> [operator] declared in kotlin.collections.MutableList' type=kotlin.collections.MutableIterator<<root>.P?> origin=null
+        CALL 'public abstract fun iterator (): kotlin.collections.MutableIterator<E of kotlin.collections.MutableList> [fake_override,operator] declared in kotlin.collections.MutableList' type=kotlin.collections.MutableIterator<<root>.P?> origin=null
           $this: CALL 'public open fun listOfNotNull (): kotlin.collections.List<<root>.P?>? declared in <root>.J' type=kotlin.collections.List<<root>.P?>? origin=null
       WHILE label=null origin=WHILE_LOOP
         condition: CALL 'public abstract fun hasNext (): kotlin.Boolean [operator] declared in kotlin.collections.Iterator' type=kotlin.Boolean origin=null
           $this: GET_VAR 'val iterator: kotlin.collections.MutableIterator<<root>.P?> [val] declared in <root>.testDesugaredForInList' type=kotlin.collections.MutableIterator<<root>.P?> origin=null
         body: BLOCK type=kotlin.Unit origin=WHILE_LOOP
           VAR name:x type:<root>.P? [val]
-            CALL 'public abstract fun next (): T of kotlin.collections.MutableIterator [operator] declared in kotlin.collections.MutableIterator' type=<root>.P? origin=null
+            CALL 'public abstract fun next (): T of kotlin.collections.MutableIterator [fake_override,operator] declared in kotlin.collections.MutableIterator' type=<root>.P? origin=null
               $this: GET_VAR 'val iterator: kotlin.collections.MutableIterator<<root>.P?> [val] declared in <root>.testDesugaredForInList' type=kotlin.collections.MutableIterator<<root>.P?> origin=null
   FUN name:testForInArrayUnused visibility:public modality:FINAL <> (j:<root>.J) returnType:kotlin.Unit
     VALUE_PARAMETER name:j index:0 type:<root>.J
@@ -65,14 +65,14 @@ FILE fqName:<root> fileName:/enhancedNullabilityInForLoop.kt
     BLOCK_BODY
       BLOCK type=kotlin.Unit origin=FOR_LOOP
         VAR FOR_LOOP_ITERATOR name:tmp_3 type:kotlin.collections.MutableIterator<<root>.P?> [val]
-          CALL 'public abstract fun iterator (): kotlin.collections.MutableIterator<E of kotlin.collections.MutableList> [operator] declared in kotlin.collections.MutableList' type=kotlin.collections.MutableIterator<<root>.P?> origin=FOR_LOOP_ITERATOR
+          CALL 'public abstract fun iterator (): kotlin.collections.MutableIterator<E of kotlin.collections.MutableList> [fake_override,operator] declared in kotlin.collections.MutableList' type=kotlin.collections.MutableIterator<<root>.P?> origin=FOR_LOOP_ITERATOR
             $this: CALL 'public open fun listOfNotNull (): kotlin.collections.List<<root>.P?>? declared in <root>.J' type=kotlin.collections.List<<root>.P?>? origin=null
         WHILE label=null origin=FOR_LOOP_INNER_WHILE
           condition: CALL 'public abstract fun hasNext (): kotlin.Boolean [operator] declared in kotlin.collections.Iterator' type=kotlin.Boolean origin=FOR_LOOP_HAS_NEXT
             $this: GET_VAR 'val tmp_3: kotlin.collections.MutableIterator<<root>.P?> [val] declared in <root>.testForInListUse' type=kotlin.collections.MutableIterator<<root>.P?> origin=null
           body: BLOCK type=kotlin.Unit origin=FOR_LOOP_INNER_WHILE
             VAR FOR_LOOP_VARIABLE name:x type:<root>.P? [val]
-              CALL 'public abstract fun next (): T of kotlin.collections.MutableIterator [operator] declared in kotlin.collections.MutableIterator' type=<root>.P? origin=FOR_LOOP_NEXT
+              CALL 'public abstract fun next (): T of kotlin.collections.MutableIterator [fake_override,operator] declared in kotlin.collections.MutableIterator' type=<root>.P? origin=FOR_LOOP_NEXT
                 $this: GET_VAR 'val tmp_3: kotlin.collections.MutableIterator<<root>.P?> [val] declared in <root>.testForInListUse' type=kotlin.collections.MutableIterator<<root>.P?> origin=null
             CALL 'public final fun use (s: <root>.P): kotlin.Unit declared in <root>' type=kotlin.Unit origin=null
               s: GET_VAR 'val x: <root>.P? [val] declared in <root>.testForInListUse' type=<root>.P? origin=null