sdk/tests/ffi/extension_methods_test.dart

// Copyright (c) 2019, the Dart project authors.  Please see the AUTHORS file
// for details. All rights reserved. Use of this source code is governed by a
// BSD-style license that can be found in the LICENSE file.

// SharedObjects=ffi_test_functions

import 'dart:ffi';

import 'package:expect/expect.dart';
import 'package:ffi/ffi.dart';

import 'dylib_utils.dart';

void main(List<String> arguments) {
  // Force dlopen so @Native lookups in DynamicLibrary.process() succeed.
  dlopenGlobalPlatformSpecific('ffi_test_functions');

  for (var i = 0; i < 100; i++) {
    testStoreLoad();
    testReifiedGeneric();
    testCompoundLoadAndStore();
    testCompoundRefWithFinalizer();
  }
  print('done');
}

void testStoreLoad() {
  final p = calloc<Int8>(2);
  p.value = 10;
  Expect.equals(10, p.value);
  p[1] = 20;
  Expect.equals(20, p[1]);
  if (sizeOf<IntPtr>() == 4) {
    // Test round tripping.
    Expect.equals(20, (p + 0x100000001).value);
    Expect.equals(20, p[0x100000001]);
  }

  // Test negative index.
  final pUseNegative = p + 1;
  Expect.equals(10, pUseNegative[-1]);

  // Test negative index using operators
  final pUseNegative1 = p + 1;
  Expect.equals(10, pUseNegative1[-1]);

  final p1 = calloc<Double>(2);
  p1.value = 10.0;
  Expect.approxEquals(10.0, p1.value);
  p1[1] = 20.0;
  Expect.approxEquals(20.0, p1[1]);
  calloc.free(p1);

  final p2 = calloc<Pointer<Int8>>(2);
  p2.value = p;
  Expect.equals(p, p2.value);
  p2[1] = p;
  Expect.equals(p, p2[1]);
  calloc.free(p2);
  calloc.free(p);

  final p3 = calloc<Foo>();
  Foo foo = p3.ref;
  foo.a = 1;
  Expect.equals(1, foo.a);
  calloc.free(p3);

  final p4 = calloc<Foo>(2);
  Foo src = p4[1];
  src.a = 2;
  p4.ref = src;
  Foo dst = p4.ref;
  Expect.equals(2, dst.a);
  calloc.free(p4);
}

void testReifiedGeneric() {
  final p = calloc<Pointer<Int8>>();
  Pointer<Pointer<NativeType>> p2 = p;
  Expect.isTrue(p2.value is Pointer<Int8>);
  calloc.free(p);
}

void testCompoundLoadAndStore() {
  final foos = calloc<Foo>(10);
  final reference = foos.ref..a = 10;

  for (var i = 1; i < 9; i++) {
    foos[i] = reference;
    Expect.isTrue(foos[i].a == 10);

    (foos + i).ref = reference;
    Expect.isTrue((foos + i).ref.a == 10);
  }

  for (var i = 1; i < 9; i++) {
    foos[i] = reference;
    Expect.isTrue(foos[i].a == 10);

    (foos + i).ref = reference;
    Expect.isTrue((foos + i).ref.a == 10);
  }

  final bars = calloc<Bar>(10);
  bars[0].foo = reference;

  for (var i = 1; i < 9; i++) {
    bars[i] = bars[0];
    Expect.isTrue((bars + i).ref.foo.a == 10);
    Expect.isTrue((bars + i).ref.foo.a == 10);
  }

  calloc.free(foos);
  calloc.free(bars);
}

void testCompoundRefWithFinalizer() {
  final vec4 = Struct.create<Vec4>();
  vec4
    ..x = 1.2
    ..y = 3.4
    ..z = 5.6
    ..w = 7.8;
  final result = twiddleVec4Components(vec4);
  Expect.equals(3.4, result.x);
  Expect.equals(5.6, result.y);
  Expect.equals(7.8, result.z);
  Expect.equals(1.2, result.w);
}

Vec4 twiddleVec4Components(Vec4 input) {
  final result = calloc<Vec4>();
  nativeTwiddleVec4Components(input, result);
  return result.refWithFinalizer(calloc.nativeFree);
}

@Native<Void Function(Vec4, Pointer<Vec4>)>(
  symbol: 'TwiddleVec4Components',
  isLeaf: true,
)
external void nativeTwiddleVec4Components(Vec4 input, Pointer<Vec4> result);

final class Foo extends Struct {
  @Int8()
  external int a;
}

final class Bar extends Union {
  external Foo foo;
  @Int32()
  external int baz;
}

final class Vec4 extends Struct {
  @Double()
  external double x;
  @Double()
  external double y;
  @Double()
  external double z;
  @Double()
  external double w;
}