[vm/ffi] Tests for aliasing
Issue: https://github.com/dart-lang/sdk/issues/36247
Change-Id: I81f4cb1d34bc25efe6bc4c2d14615356ac52262f
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/106906
Commit-Queue: Daco Harkes <dacoharkes@google.com>
Auto-Submit: Daco Harkes <dacoharkes@google.com>
Reviewed-by: Martin Kustermann <kustermann@google.com>
diff --git a/tests/ffi/aliasing_test.dart b/tests/ffi/aliasing_test.dart
new file mode 100644
index 0000000..0cb2f17
--- /dev/null
+++ b/tests/ffi/aliasing_test.dart
@@ -0,0 +1,218 @@
+// 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.
+//
+// Dart test programing for testing that optimizations do wrongly assume loads
+// from and stores to C memory are not aliased.
+//
+// SharedObjects=ffi_test_functions
+// VMOptions=--deterministic --optimization-counter-threshold=50 --enable-inlining-annotations
+
+library FfiTest;
+
+import 'dart:ffi';
+
+import "package:expect/expect.dart";
+
+import 'dylib_utils.dart';
+
+void main() {
+ for (int i = 0; i < 100; ++i) {
+ testNonAlias();
+ testAliasCast();
+ testAliasCast2();
+ testAliasOffsetBy();
+ testAliasOffsetBy2();
+ testAliasElementAt();
+ testAliasElementAt2();
+ testAliasFromAddress();
+ testAliasFromAddress2();
+ testAliasFromAddressViaMemory();
+ testAliasFromAddressViaMemory2();
+ testAliasFromAddressViaNativeFunction();
+ testAliasFromAddressViaNativeFunction2();
+ testPartialOverlap();
+ }
+}
+
+void testNonAlias() {
+ final source = allocate<Int64>();
+ source.store(42);
+ final int a = source.load();
+ source.store(1984);
+ // alias.load() should be re-executed, as we wrote to alias.
+ Expect.notEquals(a, source.load<int>());
+ source.free();
+}
+
+void testAliasCast() {
+ final source = allocate<Int64>();
+ final alias = source.cast<Pointer<Int8>>().cast<Pointer<Int64>>();
+ source.store(42);
+ final int a = source.load();
+ alias.store(1984);
+ // source.load() should be re-executed, we wrote alias which aliases source.
+ Expect.notEquals(a, source.load<int>());
+ source.free();
+}
+
+void testAliasCast2() {
+ final source = allocate<Int64>();
+ final alias = source.cast<Pointer<Int16>>().cast<Pointer<Int64>>();
+ final alias2 = source.cast<Pointer<Int8>>().cast<Pointer<Int64>>();
+ alias.store(42);
+ final int a = alias.load();
+ alias2.store(1984);
+ // alias.load() should be re-executed, we wrote alias2 which aliases alias.
+ Expect.notEquals(a, alias.load<int>());
+ source.free();
+}
+
+void testAliasOffsetBy() {
+ final source = allocate<Int64>(count: 2);
+ final alias = source.offsetBy(8).offsetBy(-8);
+ source.store(42);
+ final int a = source.load();
+ alias.store(1984);
+ // source.load() should be re-executed, we wrote alias which aliases source.
+ Expect.notEquals(a, source.load<int>());
+ source.free();
+}
+
+void testAliasOffsetBy2() {
+ final source = allocate<Int64>(count: 3);
+ final alias = source.offsetBy(16).offsetBy(-16);
+ final alias2 = source.offsetBy(8).offsetBy(-8);
+ alias.store(42);
+ final int a = alias.load();
+ alias2.store(1984);
+ // alias.load() should be re-executed, we wrote alias2 which aliases alias.
+ Expect.notEquals(a, alias.load<int>());
+ source.free();
+}
+
+void testAliasElementAt() {
+ final source = allocate<Int64>(count: 2);
+ final alias = source.elementAt(1).elementAt(-1);
+ source.store(42);
+ final int a = source.load();
+ alias.store(1984);
+ // source.load() should be re-executed, we wrote alias which aliases source.
+ Expect.notEquals(a, source.load<int>());
+ source.free();
+}
+
+void testAliasElementAt2() {
+ final source = allocate<Int64>(count: 3);
+ final alias = source.elementAt(2).elementAt(-2);
+ final alias2 = source.elementAt(1).elementAt(-1);
+ alias.store(42);
+ final int a = alias.load();
+ alias2.store(1984);
+ // alias.load() should be re-executed, we wrote alias2 which aliases alias.
+ Expect.notEquals(a, alias.load<int>());
+ source.free();
+}
+
+void testAliasFromAddress() {
+ final source = allocate<Int64>();
+ final alias = fromAddress<Pointer<Int64>>(source.address);
+ source.store(42);
+ final int a = source.load();
+ alias.store(1984);
+ // source.load() should be re-executed, we wrote alias which aliases source.
+ Expect.notEquals(a, source.load<int>());
+ source.free();
+}
+
+void testAliasFromAddress2() {
+ final source = allocate<Int64>();
+ final alias = fromAddress<Pointer<Int64>>(source.address);
+ final alias2 = fromAddress<Pointer<Int64>>(source.address);
+ alias.store(42);
+ final int a = alias.load();
+ alias2.store(1984);
+ // alias.load() should be re-executed, we wrote alias2 which aliases alias.
+ Expect.notEquals(a, alias.load<int>());
+ source.free();
+}
+
+void testAliasFromAddressViaMemory() {
+ final helper = allocate<IntPtr>();
+ final source = allocate<Int64>();
+ helper.store(source.address);
+ final alias = fromAddress<Pointer<Int64>>(helper.load());
+ source.store(42);
+ final int a = source.load();
+ alias.store(1984);
+ // source.load() should be re-executed, we wrote alias which aliases source.
+ Expect.notEquals(a, source.load<int>());
+ helper.free();
+ source.free();
+}
+
+void testAliasFromAddressViaMemory2() {
+ final helper = allocate<IntPtr>();
+ final source = allocate<Int64>();
+ helper.store(source.address);
+ final alias = fromAddress<Pointer<Int64>>(helper.load());
+ final alias2 = fromAddress<Pointer<Int64>>(helper.load());
+ alias.store(42);
+ final int a = alias.load();
+ alias2.store(1984);
+ // alias.load() should be re-executed, we wrote alias2 which aliases alias.
+ Expect.notEquals(a, alias.load<int>());
+ helper.free();
+ source.free();
+}
+
+typedef NativeQuadOpSigned = Int64 Function(Int8, Int16, Int32, Int64);
+typedef QuadOp = int Function(int, int, int, int);
+
+DynamicLibrary ffiTestFunctions = dlopenPlatformSpecific("ffi_test_functions");
+
+QuadOp intComputation = ffiTestFunctions
+ .lookupFunction<NativeQuadOpSigned, QuadOp>("IntComputation");
+
+void testAliasFromAddressViaNativeFunction() {
+ final source = allocate<Int64>();
+ final alias =
+ fromAddress<Pointer<Int64>>(intComputation(0, 0, 0, source.address));
+ source.store(42);
+ final int a = source.load();
+ alias.store(1984);
+ // source.load() should be re-executed, we wrote alias which aliases source.
+ Expect.notEquals(a, source.load<int>());
+ source.free();
+}
+
+void testAliasFromAddressViaNativeFunction2() {
+ final source = allocate<Int64>();
+ final alias =
+ fromAddress<Pointer<Int64>>(intComputation(0, 0, 0, source.address));
+ final alias2 =
+ fromAddress<Pointer<Int64>>(intComputation(0, 0, 0, source.address));
+ alias.store(42);
+ final int a = alias.load();
+ alias2.store(1984);
+ // alias.load() should be re-executed, we wrote alias2 which aliases alias.
+ Expect.notEquals(a, alias.load<int>());
+ source.free();
+}
+
+// TODO(dacoharkes): Replace with @pragma annotations once available.
+const NeverInline = 'NeverInline';
+
+@NeverInline
+Pointer<Int8> makeDerived(Pointer<Int64> source) =>
+ source.offsetBy(7).cast<Pointer<Int8>>();
+
+testPartialOverlap() {
+ final source = allocate<Int64>(count: 2);
+ final derived = makeDerived(source);
+ source.store(0x1122334455667788);
+ final int value = source.load();
+ derived.store(0xaa);
+ Expect.notEquals(value, source.load<int>());
+ source.free();
+}
