Minorly rework CValuesRef to make it more universal when subclassing

Allow `getPointer` to register custom disposers with `defer`

Interop/Indexer/src/main/kotlin/org/jetbrains/kotlin/native/interop/indexer/Utils.kt

@@ -184,9 +184,9 @@ internal fun CValue<CXCursor>.isLeaf(): Boolean {
     return !hasChildren
 }
 
-internal fun List<String>.toNativeStringArray(placement: NativePlacement): CArrayPointer<CPointerVar<ByteVar>> {
+internal fun List<String>.toNativeStringArray(scope: AutofreeScope): CArrayPointer<CPointerVar<ByteVar>> {
-    return placement.allocArray(this.size) { index ->
+    return scope.allocArray(this.size) { index ->
-        this.value = this@toNativeStringArray[index].cstr.getPointer(placement)
+        this.value = this@toNativeStringArray[index].cstr.getPointer(scope)
     }
 }
 

Interop/Runtime/src/main/kotlin/kotlinx/cinterop/Types.kt

@@ -70,26 +70,7 @@ abstract class CValuesRef<T : CPointed> {
      * If this reference is [CPointer], returns this pointer.
      * Otherwise copies the referenced values to [placement] and returns the pointer to the copy.
      */
-    abstract fun getPointer(placement: NativePlacement): CPointer<T>
+    abstract fun getPointer(scope: AutofreeScope): CPointer<T>
-}
-
-inline fun <T : CPointed, R> CValuesRef<T>?.usePointer(block: (CPointer<T>?) -> R): R {
-    val allocated: Boolean
-    val pointer: CPointer<T>? = if (this is CPointer<T>?) {
-        allocated = false
-        this
-    } else {
-        allocated = true
-        this!!.getPointer(nativeHeap)
-    }
-
-    return try {
-        block(pointer)
-    } finally {
-        if (allocated) {
-            nativeHeap.free(pointer.rawValue)
-        }
-    }
 }
 
 /**
@@ -100,7 +81,7 @@ abstract class CValues<T : CVariable> : CValuesRef<T>() {
     /**
      * Copies the values to [placement] and returns the pointer to the copy.
      */
-    override abstract fun getPointer(placement: NativePlacement): CPointer<T>
+    override abstract fun getPointer(scope: AutofreeScope): CPointer<T>
 
     // TODO: optimize
     override fun equals(other: Any?): Boolean {
@@ -134,7 +115,7 @@ abstract class CValues<T : CVariable> : CValuesRef<T>() {
     abstract val size: Int
 }
 
-fun <T : CVariable> CValues<T>.placeTo(placement: NativePlacement) = this.getPointer(placement)
+fun <T : CVariable> CValues<T>.placeTo(scope: AutofreeScope) = this.getPointer(scope)
 
 /**
  * The single immutable C value.
@@ -163,7 +144,7 @@ class CPointer<T : CPointed> internal constructor(val rawValue: NativePtr) : CVa
 
     override fun toString() = this.cPointerToString()
 
-    override fun getPointer(placement: NativePlacement) = this
+    override fun getPointer(scope: AutofreeScope) = this
 }
 
 /**

Interop/Runtime/src/main/kotlin/kotlinx/cinterop/Utils.kt

@@ -65,7 +65,11 @@ open class DeferScope {
     }
 }
 
-open class ArenaBase(private val parent: NativeFreeablePlacement = nativeHeap) : NativePlacement, DeferScope() {
+abstract class AutofreeScope : DeferScope(), NativePlacement {
+    override abstract fun alloc(size: Long, align: Int): NativePointed
+}
+
+open class ArenaBase(private val parent: NativeFreeablePlacement = nativeHeap) : AutofreeScope() {
 
     private var lastChunk: NativePointed? = null
 
@@ -209,8 +213,8 @@ fun NativePlacement.allocArrayOf(vararg elements: Float): CArrayPointer<FloatVar
 fun <T : CPointed> NativePlacement.allocPointerTo() = alloc<CPointerVar<T>>()
 
 fun <T : CVariable> zeroValue(size: Int, align: Int): CValue<T> = object : CValue<T>() {
-    override fun getPointer(placement: NativePlacement): CPointer<T> {
+    override fun getPointer(scope: AutofreeScope): CPointer<T> {
-        val result = placement.alloc(size, align)
+        val result = scope.alloc(size, align)
         nativeMemUtils.zeroMemory(result, size)
         return interpretCPointer(result.rawPtr)!!
     }
@@ -232,7 +236,7 @@ fun <T : CVariable> CPointed.readValues(size: Int, align: Int): CValues<T> {
     nativeMemUtils.getByteArray(this, bytes, size)
 
     return object : CValues<T>() {
-        override fun getPointer(placement: NativePlacement): CPointer<T> = placement.placeBytes(bytes, align)
+        override fun getPointer(scope: AutofreeScope): CPointer<T> = scope.placeBytes(bytes, align)
         override val size get() = bytes.size
     }
 }
@@ -244,7 +248,7 @@ fun <T : CVariable> CPointed.readValue(size: Long, align: Int): CValue<T> {
     val bytes = ByteArray(size.toInt())
     nativeMemUtils.getByteArray(this, bytes, size.toInt())
     return object : CValue<T>() {
-        override fun getPointer(placement: NativePlacement): CPointer<T> = placement.placeBytes(bytes, align)
+        override fun getPointer(scope: AutofreeScope): CPointer<T> = scope.placeBytes(bytes, align)
         override val size get() = bytes.size
     }
 }
@@ -255,7 +259,7 @@ inline fun <reified T : CStructVar> T.readValue(): CValue<T> = this.readValue(si
 
 fun CValue<*>.write(location: NativePtr) {
     // TODO: probably CValue must be redesigned.
-    val fakePlacement = object : NativePlacement {
+    val fakeScope = object : AutofreeScope() {
         var used = false
         override fun alloc(size: Long, align: Int): NativePointed {
             assert(!used)
@@ -264,8 +268,8 @@ fun CValue<*>.write(location: NativePtr) {
         }
     }
 
-    this.getPointer(fakePlacement)
+    this.getPointer(fakeScope)
-    assert(fakePlacement.used)
+    assert(fakeScope.used)
 }
 
 // TODO: optimize
@@ -302,7 +306,7 @@ inline fun <reified T : CVariable> createValues(count: Int, initializer: T.(inde
 }
 
 fun cValuesOf(vararg elements: Byte): CValues<ByteVar> = object : CValues<ByteVar>() {
-    override fun getPointer(placement: NativePlacement) = placement.allocArrayOf(elements)
+    override fun getPointer(scope: AutofreeScope) = scope.allocArrayOf(elements)
     override val size get() = 1 * elements.size
 }
 
@@ -318,7 +322,7 @@ fun cValuesOf(vararg elements: Long): CValues<LongVar> =
         createValues(elements.size) { index -> this.value = elements[index] }
 
 fun cValuesOf(vararg elements: Float): CValues<FloatVar> = object : CValues<FloatVar>() {
-    override fun getPointer(placement: NativePlacement) = placement.allocArrayOf(*elements)
+    override fun getPointer(scope: AutofreeScope) = scope.allocArrayOf(*elements)
     override val size get() = 4 * elements.size
 }
 
@@ -348,8 +352,8 @@ val String.cstr: CValues<ByteVar>
         return object : CValues<ByteVar>() {
             override val size get() = bytes.size + 1
 
-            override fun getPointer(placement: NativePlacement): CPointer<ByteVar> {
+            override fun getPointer(scope: AutofreeScope): CPointer<ByteVar> {
-                val result = placement.allocArray<ByteVar>(bytes.size + 1)
+                val result = scope.allocArray<ByteVar>(bytes.size + 1)
                 nativeMemUtils.putByteArray(bytes, result.pointed, bytes.size)
                 result[bytes.size] = 0.toByte()
                 return result
@@ -363,8 +367,8 @@ val String.wcstr: CValues<ShortVar>
         return object : CValues<ShortVar>() {
             override val size get() = 2 * (chars.size + 1)
 
-            override fun getPointer(placement: NativePlacement): CPointer<ShortVar> {
+            override fun getPointer(scope: AutofreeScope): CPointer<ShortVar> {
-                val result = placement.allocArray<ShortVar>(chars.size + 1)
+                val result = scope.allocArray<ShortVar>(chars.size + 1)
                 nativeMemUtils.putCharArray(chars, result.pointed, chars.size)
                 result[chars.size] = 0.toShort()
                 return result

Interop/Runtime/src/native/kotlin/kotlinx/cinterop/Varargs.kt

@@ -16,7 +16,7 @@ const val FFI_TYPE_KIND_POINTER: FfiTypeKind = 7
 
 private tailrec fun convertArgument(
         argument: Any?, isVariadic: Boolean, location: COpaquePointer,
-        additionalPlacement: NativePlacement
+        additionalPlacement: AutofreeScope
 ): FfiTypeKind = when (argument) {
     is CValuesRef<*>? -> {
         location.reinterpret<CPointerVar<*>>()[0] = argument?.getPointer(additionalPlacement)
@@ -96,7 +96,7 @@ inline fun <reified T  : CVariable> NativePlacement.allocFfiReturnValueBuffer(ty
 
 fun callWithVarargs(codePtr: NativePtr, returnValuePtr: NativePtr, returnTypeKind: FfiTypeKind,
                     fixedArguments: Array<out Any?>, variadicArguments: Array<out Any?>,
-                    argumentsPlacement: NativePlacement) {
+                    argumentsPlacement: AutofreeScope) {
 
     val totalArgumentsNumber = fixedArguments.size + variadicArguments.size
 

Interop/StubGenerator/src/main/kotlin/org/jetbrains/kotlin/native/interop/gen/CodeBuilders.kt

@@ -40,6 +40,14 @@ class KotlinCodeBuilder {
         lines.add("    ".repeat(nesting) + line)
     }
 
+    private var memScoped = false
+    fun pushMemScoped() {
+        if (!memScoped) {
+            memScoped = true
+            pushBlock("memScoped {")
+        }
+    }
+
     fun pushBlock(line: String, free: String = "") {
         out(line)
         freeStack.add(free)

Interop/StubGenerator/src/main/kotlin/org/jetbrains/kotlin/native/interop/gen/MappingBridgeGeneratorImpl.kt

@@ -41,9 +41,9 @@ class MappingBridgeGeneratorImpl(
 
         kotlinValues.forEachIndexed { index, (type, value) ->
             if (type.unwrapTypedefs() is RecordType) {
-                val tmpVarName = "kni$index"
+                builder.pushMemScoped()
-                builder.pushBlock("$value.usePointer { $tmpVarName ->")
+                val bridgeArgument = "$value.getPointer(memScope).rawValue"
-                bridgeArguments.add(BridgeTypedKotlinValue(BridgedType.NATIVE_PTR, "$tmpVarName.rawValue"))
+                bridgeArguments.add(BridgeTypedKotlinValue(BridgedType.NATIVE_PTR, bridgeArgument))
             } else {
                 val info = mirror(declarationMapper, type).info
                 bridgeArguments.add(BridgeTypedKotlinValue(info.bridgedType, info.argToBridged(value)))

Interop/StubGenerator/src/main/kotlin/org/jetbrains/kotlin/native/interop/gen/jvm/StubGenerator.kt

@@ -599,24 +599,22 @@ class StubGenerator(
                     }
                 }
 
-                val tmpVarName = "kniTmp$index"
-
                 val representAsValuesRef = representCFunctionParameterAsValuesRef(parameter.type)
 
                 val bridgeArgument = if (representCFunctionParameterAsString(parameter.type)) {
                     kotlinParameters.add(parameterName to KotlinTypes.string.makeNullable())
-                    bodyGenerator.pushBlock("$parameterName?.cstr.usePointer { $tmpVarName ->")
+                    bodyGenerator.pushMemScoped()
-                    tmpVarName
+                    "$parameterName?.cstr?.getPointer(memScope)"
                 } else if (representCFunctionParameterAsWString(parameter.type)) {
                     kotlinParameters.add(parameterName to KotlinTypes.string.makeNullable())
-                    bodyGenerator.pushBlock("$parameterName?.wcstr.usePointer { $tmpVarName ->")
+                    bodyGenerator.pushMemScoped()
-                    tmpVarName
+                    "$parameterName?.wcstr?.getPointer(memScope)"
                 } else if (representAsValuesRef != null) {
                     val pointedType = mirror(representAsValuesRef).pointedType
                     val parameterType = KotlinTypes.cValuesRef.typeWith(pointedType).makeNullable()
                     kotlinParameters.add(parameterName to parameterType)
-                    bodyGenerator.pushBlock("$parameterName.usePointer { $tmpVarName ->")
+                    bodyGenerator.pushMemScoped()
-                    tmpVarName
+                    "$parameterName?.getPointer(memScope)"
                 } else {
                     val mirror = mirror(parameter.type)
                     kotlinParameters.add(parameterName to mirror.argType)
@@ -640,7 +638,7 @@ class StubGenerator(
                 val returnTypeKind = getFfiTypeKind(func.returnType)
 
                 kotlinParameters.add("vararg variadicArguments" to KotlinTypes.any.makeNullable())
-                bodyGenerator.pushBlock("memScoped {")
+                bodyGenerator.pushMemScoped()
 
                 val resultVar = "kniResult"
 

runtime/src/main/kotlin/konan/internal/InteropBoxing.kt

@@ -67,7 +67,7 @@ class CPointerBox(val value: CPointer<CPointed>) : CValuesRef<CPointed>() {
 
     override fun toString() = value.toString()
 
-    override fun getPointer(placement: NativePlacement) = value.getPointer(placement)
+    override fun getPointer(scope: AutofreeScope) = value.getPointer(scope)
 }
 
 fun boxCPointer(value: CPointer<CPointed>?) = if (value != null) CPointerBox(value) else null