Call toString() within known class, during string concatenation type narrowing

^KT-53119 Improved

Merge-request: KT-MR-6755
Merged-by: Vladimir Sukharev <Vladimir.Sukharev@jetbrains.com>

kotlin-native/backend.native/compiler/ir/backend.native/src/org/jetbrains/kotlin/backend/konan/lower/StringConcatenationTypeNarrowing.kt

@@ -19,6 +19,7 @@ import org.jetbrains.kotlin.ir.util.functions
 import org.jetbrains.kotlin.ir.util.shallowCopy
 import org.jetbrains.kotlin.ir.visitors.transformChildrenVoid
 import org.jetbrains.kotlin.name.Name
+import org.jetbrains.kotlin.util.OperatorNameConventions
 
 /**
  * This pass replaces calls to:
@@ -134,9 +135,15 @@ internal class StringConcatenationTypeNarrowing(val context: Context) : FileLowe
     private fun buildNonNullableArgToString(argument: IrExpression): IrExpression {
         return if (argument.type.isString() || argument.type.isNullableString())
             argument
-        else builder
+        else {
-                .irCall(context.ir.symbols.memberToString, context.irBuiltIns.stringType, valueArgumentsCount = 1, typeArgumentsCount = 0)
+            val calleeOrNull = argument.type.classOrNull?.owner?.functions?.singleOrNull {
-                .apply { dispatchReceiver = argument }
+                it.name == OperatorNameConventions.TO_STRING && it.valueParameters.isEmpty()
+            }?.symbol
+            val callee = calleeOrNull ?: context.ir.symbols.memberToString  // defaults to `Any.toString()`
+            builder
+                    .irCall(callee, callee.owner.returnType, valueArgumentsCount = 0, typeArgumentsCount = 0)
+                    .apply { dispatchReceiver = argument }
+        }
     }
 
     /**

kotlin-native/backend.native/tests/codegen/stringConcatenationTypeNarrowing/kt53119_append_generated.kt

@@ -59,6 +59,40 @@ fun maybeAnyString(maybeAny1: Any?, string: String): String {
 
 data class Foo(val bar: Int)
 
+// CHECK-LABEL: define %struct.ObjHeader* @"kfun:codegen.stringConcatenationTypeNarrowing.kt53119_append_generated#maybeAnyFoo
+// CHECK: %struct.ObjHeader* @"kfun:kotlin.text.StringBuilder#append(kotlin.String?)
+// CHECK: %struct.ObjHeader* @"kfun:kotlin.text.StringBuilder#append(kotlin.String)
+// CHECK-NOT: %struct.ObjHeader* @"kfun:kotlin.text.StringBuilder#append
+// CHECK: %struct.ObjHeader* @"kfun:codegen.stringConcatenationTypeNarrowing.kt53119_append_generated.Foo#toString(){}kotlin.String"
+// CHECK-NOT: Foo#toString(){}kotlin.String
+// CHECK: %struct.ObjHeader* @"kfun:kotlin.text.StringBuilder#append(kotlin.String?)
+// CHECK-NOT: %struct.ObjHeader* @"kfun:kotlin.text.StringBuilder#append
+
+// CHECK: %struct.ObjHeader* @"kfun:codegen.stringConcatenationTypeNarrowing.kt53119_append_generated.Foo#toString(){}kotlin.String"
+// CHECK-NOT: Foo#toString(){}kotlin.String"
+
+// CHECK-NOT: %struct.ObjHeader* @"kfun:kotlin.text.StringBuilder#append
+// CHECK: ret %struct.ObjHeader*
+
+fun maybeAnyFoo(maybeAny: Any?, foo: Foo): String {
+    return "$maybeAny,$foo"
+}
+// CHECK-LABEL: define %struct.ObjHeader* @"kfun:codegen.stringConcatenationTypeNarrowing.kt53119_append_generated#maybeAnyMaybeFoo
+// CHECK: %struct.ObjHeader* @"kfun:kotlin.text.StringBuilder#append(kotlin.String?)
+// CHECK: %struct.ObjHeader* @"kfun:kotlin.text.StringBuilder#append(kotlin.String)
+// CHECK: %struct.ObjHeader* @"kfun:kotlin.text.StringBuilder#append(kotlin.String?)
+// CHECK-NOT: %struct.ObjHeader* @"kfun:kotlin.text.StringBuilder#append
+
+// CHECK: %struct.ObjHeader* @"kfun:codegen.stringConcatenationTypeNarrowing.kt53119_append_generated.Foo#toString(){}kotlin.String"
+// CHECK: %struct.ObjHeader* @"kfun:codegen.stringConcatenationTypeNarrowing.kt53119_append_generated.Foo#toString(){}kotlin.String"
+// CHECK-NOT: Foo#toString(){}kotlin.String"
+
+// CHECK-NOT: %struct.ObjHeader* @"kfun:kotlin.text.StringBuilder#append
+// CHECK: ret %struct.ObjHeader*
+
+fun maybeAnyMaybeFoo(maybeAny: Any?, foo: Foo?): String {
+    return "$maybeAny,$foo"
+}
 @Test
 fun runTest() {
     val foo = Foo(42)
@@ -68,4 +102,8 @@ fun runTest() {
     println(maybeAnyMaybeString(null, null))
     println(maybeAnyString(foo, "bar"))
     println(maybeAnyString(null, "bar"))
+    println(maybeAnyFoo(foo, foo))
+    println(maybeAnyFoo(null, foo))
+    println(maybeAnyMaybeFoo(foo, foo))
+    println(maybeAnyMaybeFoo(foo, null))
 }

kotlin-native/backend.native/tests/codegen/stringConcatenationTypeNarrowing/kt53119_append_generated.out

@@ -4,3 +4,7 @@ Foo(bar=42),bar
 null,null
 Foo(bar=42),bar
 null,bar
+Foo(bar=42),Foo(bar=42)
+null,Foo(bar=42)
+Foo(bar=42),Foo(bar=42)
+Foo(bar=42),null

kotlin-native/backend.native/tests/codegen/stringConcatenationTypeNarrowing/kt53119_append_manual.kt

@@ -67,6 +67,21 @@ fun appendString(str: String): String {
 
 data class Foo(val bar: Int)
 
+// CHECK-LABEL: define %struct.ObjHeader* @"kfun:codegen.stringConcatenationTypeNarrowing.kt53119_append_manual#appendFoo(codegen.stringConcatenationTypeNarrowing.kt53119_append_manual.Foo)
+// CHECK: %struct.ObjHeader* @"kfun:codegen.stringConcatenationTypeNarrowing.kt53119_append_manual.Foo#toString(){}kotlin.String"
+// CHECK-NOT: Foo#toString(){}kotlin.String"
+// CHECK: %struct.ObjHeader* @"kfun:kotlin.text.StringBuilder#append(kotlin.String?)
+
+// CHECK-NOT: Foo#toString(){}kotlin.String"
+// CHECK-NOT: %struct.ObjHeader* @"kfun:kotlin.text.StringBuilder#append
+// CHECK: ret %struct.ObjHeader*
+
+fun appendFoo(foo: Foo): String {
+    val sb = kotlin.text.StringBuilder()
+    sb.append(foo)
+    return sb.toString()
+}
+
 @Test
 fun runTest() {
     val foo = Foo(42)
@@ -76,4 +91,5 @@ fun runTest() {
     println(appendMaybeString("foo"))
     println(appendMaybeString(null))
     println(appendString("foo"))
+    println(appendFoo(foo))
 }

kotlin-native/backend.native/tests/codegen/stringConcatenationTypeNarrowing/kt53119_append_manual.out

@@ -4,3 +4,4 @@ Foo(bar=42)
 foo
 null
 foo
+Foo(bar=42)

kotlin-native/backend.native/tests/codegen/stringConcatenationTypeNarrowing/kt53119_plus_extension.kt

@@ -77,6 +77,43 @@ fun generatedPlusExtensionString(maybeStr: String?, str: String): String {
 
 data class Foo(val bar: Int)
 
+// CHECK-LABEL: define %struct.ObjHeader* @"kfun:codegen.stringConcatenationTypeNarrowing.kt53119_plus_extension#generatedPlusExtensionFoo
+// CHECK-NOT: kfun:kotlin.String#plus(kotlin.Any?)
+
+// CHECK: call %struct.ObjHeader* @"kfun:codegen.stringConcatenationTypeNarrowing.kt53119_plus_extension.Foo#toString(){}kotlin.String"
+// CHECK-NOT: Foo#toString(){}kotlin.String
+
+// CHECK: call %struct.ObjHeader* @Kotlin_String_plusImpl
+// CHECK-NOT: call %struct.ObjHeader* @Kotlin_String_plusImpl
+
+// CHECK-NOT: call %struct.ObjHeader* @"kfun:kotlin.String#toString(){}kotlin.String"
+// CHECK-NOT: kfun:kotlin.String#plus(kotlin.Any?)
+
+// CHECK: ret %struct.ObjHeader*
+
+fun generatedPlusExtensionFoo(maybeStr: String?, foo: Foo): String {
+    return "$maybeStr$foo"
+}
+
+// CHECK-LABEL: define %struct.ObjHeader* @"kfun:codegen.stringConcatenationTypeNarrowing.kt53119_plus_extension#generatedPlusExtensionMaybeFoo
+// CHECK-NOT: kfun:kotlin.String#plus(kotlin.Any?)
+
+// CHECK: call %struct.ObjHeader* @Kotlin_String_plusImpl
+// CHECK-NOT: call %struct.ObjHeader* @Kotlin_String_plusImpl
+// CHECK-NOT: call %struct.ObjHeader* @"kfun:kotlin.String#toString(){}kotlin.String"
+
+// CHECK: call %struct.ObjHeader* @"kfun:codegen.stringConcatenationTypeNarrowing.kt53119_plus_extension.Foo#toString(){}kotlin.String"
+// CHECK-NOT: Foo#toString(){}kotlin.String
+
+// CHECK-NOT: call %struct.ObjHeader* @"kfun:kotlin.String#toString(){}kotlin.String"
+// CHECK-NOT: kfun:kotlin.String#plus(kotlin.Any?)
+
+// CHECK: ret %struct.ObjHeader*
+
+fun generatedPlusExtensionMaybeFoo(maybeStr: String?, foo: Foo?): String {
+    return "$maybeStr$foo"
+}
+
 @Test
 fun runTest() {
     val foo = Foo(42)
@@ -88,4 +125,7 @@ fun runTest() {
     println(generatedPlusExtensionAny(null, null))
     println(generatedPlusExtensionString("foo", "bar"))
     println(generatedPlusExtensionString(null, "bar"))
+    println(generatedPlusExtensionFoo(null, Foo(42)))
+    println(generatedPlusExtensionMaybeFoo("foo", Foo(42)))
+    println(generatedPlusExtensionMaybeFoo("foo", null))
 }

kotlin-native/backend.native/tests/codegen/stringConcatenationTypeNarrowing/kt53119_plus_extension.out

@@ -6,3 +6,6 @@ fooFoo(bar=42)
 nullnull
 foobar
 nullbar
+nullFoo(bar=42)
+fooFoo(bar=42)
+foonull

kotlin-native/backend.native/tests/codegen/stringConcatenationTypeNarrowing/kt53119_plus_member.kt

@@ -68,6 +68,33 @@ fun generatedPlusMemberString(str1: String, str2: String): String {
 
 data class Foo(val bar: Int)
 
+// CHECK-LABEL: define %struct.ObjHeader* @"kfun:codegen.stringConcatenationTypeNarrowing.kt53119_plus_member#manualPlusMemberFoo
+// CHECK-NOT: kfun:kotlin.String#plus(kotlin.Any?)
+// CHECK call %struct.ObjHeader* @"kfun:codegen.stringConcatenationTypeNarrowing.kt53119_plus_member.Foo#toString(){}kotlin.String"
+// CHECK-NOT Foo#toString(){}kotlin.String
+
+// CHECK: call %struct.ObjHeader* @Kotlin_String_plusImpl
+// CHECK-NOT: kfun:kotlin.String#plus(kotlin.Any?)
+// CHECK-NOT: Foo#toString(){}kotlin.String"
+
+// CHECK: ret %struct.ObjHeader*
+fun manualPlusMemberFoo(str1: String, foo: Foo): kotlin.String =
+        str1 + foo
+
+// CHECK-LABEL: define %struct.ObjHeader* @"kfun:codegen.stringConcatenationTypeNarrowing.kt53119_plus_member#manualPlusMemberMaybeFoo
+// CHECK-NOT: kfun:kotlin.String#plus(kotlin.Any?)
+// CHECK call %struct.ObjHeader* @"kfun:codegen.stringConcatenationTypeNarrowing.kt53119_plus_member.Foo#toString(){}kotlin.String"
+// CHECK-NOT Foo#toString(){}kotlin.String
+
+// CHECK: call %struct.ObjHeader* @Kotlin_String_plusImpl
+// CHECK: call %struct.ObjHeader* @"kfun:codegen.stringConcatenationTypeNarrowing.kt53119_plus_member.Foo#toString
+// CHECK-NOT: kfun:kotlin.String#plus(kotlin.Any?)
+// CHECK-NOT: Foo#toString(){}kotlin.String"
+
+// CHECK: ret %struct.ObjHeader*
+fun manualPlusMemberMaybeFoo(str1: String, foo: Foo?): kotlin.String =
+        str1 + foo
+
 @Test
 fun runTest() {
     val foo = Foo(42)
@@ -77,4 +104,7 @@ fun runTest() {
     println(generatedPlusMemberAny("foo", null))
     println(generatedPlusMemberAny("foo", foo))
     println(generatedPlusMemberString("foo", "bar"))
+    println(manualPlusMemberFoo("foo", Foo(42)))
+    println(manualPlusMemberMaybeFoo("foo", Foo(42)))
+    println(manualPlusMemberMaybeFoo("foo", null))
 }

kotlin-native/backend.native/tests/codegen/stringConcatenationTypeNarrowing/kt53119_plus_member.out

@@ -4,3 +4,6 @@ foobar
 foonull
 fooFoo(bar=42)
 foobar
+fooFoo(bar=42)
+fooFoo(bar=42)
+foonull