[vm/ffi] Pointer.asExternalTypedData to extension method

Issue: #38610

Change-Id: Ib07f50b23e3be2bce2d7b973c0f0196884397952
Cq-Include-Trybots: luci.dart.try:vm-ffi-android-debug-arm-try,vm-ffi-android-debug-arm64-try,app-kernel-linux-debug-x64-try,vm-kernel-linux-debug-ia32-try,vm-dartkb-linux-debug-simarm64-try,vm-kernel-win-debug-x64-try,vm-kernel-win-debug-ia32-try,vm-dartkb-linux-debug-x64-try,vm-kernel-precomp-linux-debug-x64-try,vm-dartkb-linux-release-x64-abi-try,vm-kernel-precomp-android-release-arm64-try,vm-kernel-asan-linux-release-x64-try,vm-kernel-linux-release-simarm-try,vm-kernel-linux-release-simarm64-try,vm-kernel-precomp-android-release-arm_x64-try,vm-kernel-reload-mac-release-simdbc64-try,vm-kernel-precomp-obfuscate-linux-release-x64-try,vm-kernel-reload-rollback-linux-debug-x64-try,vm-kernel-precomp-mac-release-simarm_x64-try
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/121384
Commit-Queue: Daco Harkes <[email protected]>
Reviewed-by: Martin Kustermann <[email protected]>

Author: dcharkes

runtime/tools/ffi/sdk_lib_ffi_generator.dart

@@ -15,19 +15,19 @@ import 'package:args/args.dart';
 // Configuration.
 //
 
-const Map<String, String> nativeToDartType = {
-  "Int8": "int",
-  "Int16": "int",
-  "Int32": "int",
-  "Int64": "int",
-  "Uint8": "int",
-  "Uint16": "int",
-  "Uint32": "int",
-  "Uint64": "int",
-  "IntPtr": "int",
-  "Float": "double",
-  "Double": "double",
-};
+const configuration = [
+  Config("Int8", "int", "Int8List", 1),
+  Config("Int16", "int", "Int16List", 2),
+  Config("Int32", "int", "Int32List", 4),
+  Config("Int64", "int", "Int64List", 8),
+  Config("Uint8", "int", "Uint8List", 1),
+  Config("Uint16", "int", "Uint16List", 2),
+  Config("Uint32", "int", "Uint32List", 4),
+  Config("Uint64", "int", "Uint64List", 8),
+  Config("IntPtr", "int", kDoNotEmit, kIntPtrElementSize),
+  Config("Float", "double", "Float32List", 4),
+  Config("Double", "double", "Float64List", 8),
+];
 
 //
 // Generator.
@@ -41,13 +41,11 @@ main(List<String> arguments) {
   generate(path, "ffi_patch.g.dart", generatePatchExtension);
 }
 
-void generate(Uri path, String fileName,
-    Function(StringBuffer, String, String) generator) {
+void generate(
+    Uri path, String fileName, Function(StringBuffer, Config) generator) {
   final buffer = StringBuffer();
   generateHeader(buffer);
-  nativeToDartType.forEach((String nativeType, String dartType) {
-    generator(buffer, nativeType, dartType);
-  });
+  configuration.forEach((Config c) => generator(buffer, c));
   generateFooter(buffer);
 
   final fullPath = path.resolve(fileName).path;
@@ -73,8 +71,12 @@ void generateHeader(StringBuffer buffer) {
   buffer.write(header);
 }
 
-void generatePublicExtension(
-    StringBuffer buffer, String nativeType, String dartType) {
+void generatePublicExtension(StringBuffer buffer, Config config) {
+  final nativeType = config.nativeType;
+  final dartType = config.dartType;
+  final typedListType = config.typedListType;
+  final elementSize = config.elementSize;
+
   final storeTrunctateInt = """
   /// Note that ints which do not fit in `$nativeType` are truncated.
 """;
@@ -92,6 +94,19 @@ void generatePublicExtension(
 
   final loadSignExtend = _isInt(nativeType) ? loadSignExtendInt : "";
 
+  final asTypedList = typedListType == kDoNotEmit
+      ? ""
+      : """
+  /// Creates a typed list view backed by memory in the address space.
+  ///
+  /// The returned view will allow access to the memory range from `address`
+  /// to `address + ${elementSize > 1 ? '$elementSize * ' : ''}length`.
+  ///
+  /// The user has to ensure the memory range is accessible while using the
+  /// returned list.
+  external $typedListType asTypedList(int length);
+""";
+
   // TODO(dartdoc-bug): Use [] instead of ``, once issue
   // https://github.com/dart-lang/dartdoc/issues/2039 is fixed.
   buffer.write("""
@@ -124,13 +139,25 @@ $loadSignExtend  ///
 $storeTruncate  ///
   /// Note that `address` needs to be aligned to the size of `$nativeType`.
   external void operator []=(int index, $dartType value);
+
+$asTypedList
 }
 
 """);
 }
 
-void generatePatchExtension(
-    StringBuffer buffer, String nativeType, String dartType) {
+void generatePatchExtension(StringBuffer buffer, Config config) {
+  final nativeType = config.nativeType;
+  final dartType = config.dartType;
+  final typedListType = config.typedListType;
+
+  final asTypedList = typedListType == kDoNotEmit
+      ? ""
+      : """
+  @patch
+  $typedListType asTypedList(int elements) => _asExternalTypedData(this, elements);
+""";
+
   buffer.write("""
 extension ${nativeType}Pointer on Pointer<$nativeType> {
  @patch
@@ -144,6 +171,8 @@ extension ${nativeType}Pointer on Pointer<$nativeType> {
 
   @patch
   operator []=(int index, $dartType value) => _store$nativeType(this, index, value);
+
+$asTypedList
 }
 
 """);
@@ -185,3 +214,15 @@ Uri dartfmtPath() {
   // pinned fully supports extension methods.
   return Uri.parse("dartfmt");
 }
+
+class Config {
+  final String nativeType;
+  final String dartType;
+  final String typedListType;
+  final int elementSize;
+  const Config(
+      this.nativeType, this.dartType, this.typedListType, this.elementSize);
+}
+
+const String kDoNotEmit = "donotemit";
+const int kIntPtrElementSize = -1;

sdk/lib/_internal/vm/lib/ffi_patch.dart

@@ -5,7 +5,7 @@
 // All imports must be in all FFI patch files to not depend on the order
 // the patches are applied.
 import "dart:_internal" show patch;
-import 'dart:typed_data' show TypedData;
+import 'dart:typed_data';
 
 const Map<Type, int> _knownSizes = {
   Int8: 1,
@@ -268,6 +268,9 @@ extension Int8Pointer on Pointer<Int8> {
 
   @patch
   operator []=(int index, int value) => _storeInt8(this, index, value);
+
+  @patch
+  Int8List asTypedList(int elements) => _asExternalTypedData(this, elements);
 }
 
 extension Int16Pointer on Pointer<Int16> {
@@ -282,6 +285,9 @@ extension Int16Pointer on Pointer<Int16> {
 
   @patch
   operator []=(int index, int value) => _storeInt16(this, index, value);
+
+  @patch
+  Int16List asTypedList(int elements) => _asExternalTypedData(this, elements);
 }
 
 extension Int32Pointer on Pointer<Int32> {
@@ -296,6 +302,9 @@ extension Int32Pointer on Pointer<Int32> {
 
   @patch
   operator []=(int index, int value) => _storeInt32(this, index, value);
+
+  @patch
+  Int32List asTypedList(int elements) => _asExternalTypedData(this, elements);
 }
 
 extension Int64Pointer on Pointer<Int64> {
@@ -310,6 +319,9 @@ extension Int64Pointer on Pointer<Int64> {
 
   @patch
   operator []=(int index, int value) => _storeInt64(this, index, value);
+
+  @patch
+  Int64List asTypedList(int elements) => _asExternalTypedData(this, elements);
 }
 
 extension Uint8Pointer on Pointer<Uint8> {
@@ -324,6 +336,9 @@ extension Uint8Pointer on Pointer<Uint8> {
 
   @patch
   operator []=(int index, int value) => _storeUint8(this, index, value);
+
+  @patch
+  Uint8List asTypedList(int elements) => _asExternalTypedData(this, elements);
 }
 
 extension Uint16Pointer on Pointer<Uint16> {
@@ -338,6 +353,9 @@ extension Uint16Pointer on Pointer<Uint16> {
 
   @patch
   operator []=(int index, int value) => _storeUint16(this, index, value);
+
+  @patch
+  Uint16List asTypedList(int elements) => _asExternalTypedData(this, elements);
 }
 
 extension Uint32Pointer on Pointer<Uint32> {
@@ -352,6 +370,9 @@ extension Uint32Pointer on Pointer<Uint32> {
 
   @patch
   operator []=(int index, int value) => _storeUint32(this, index, value);
+
+  @patch
+  Uint32List asTypedList(int elements) => _asExternalTypedData(this, elements);
 }
 
 extension Uint64Pointer on Pointer<Uint64> {
@@ -366,6 +387,9 @@ extension Uint64Pointer on Pointer<Uint64> {
 
   @patch
   operator []=(int index, int value) => _storeUint64(this, index, value);
+
+  @patch
+  Uint64List asTypedList(int elements) => _asExternalTypedData(this, elements);
 }
 
 extension IntPtrPointer on Pointer<IntPtr> {
@@ -394,6 +418,9 @@ extension FloatPointer on Pointer<Float> {
 
   @patch
   operator []=(int index, double value) => _storeFloat(this, index, value);
+
+  @patch
+  Float32List asTypedList(int elements) => _asExternalTypedData(this, elements);
 }
 
 extension DoublePointer on Pointer<Double> {
@@ -408,6 +435,9 @@ extension DoublePointer on Pointer<Double> {
 
   @patch
   operator []=(int index, double value) => _storeDouble(this, index, value);
+
+  @patch
+  Float64List asTypedList(int elements) => _asExternalTypedData(this, elements);
 }
 
 //