[analyzer/ffi] Stop non-const warnings on ..ref

Closes: #44782

TEST=pkg/analyzer/test/src/diagnostics/non_constant_type_argument_test.dart

Change-Id: I434b9e68fb07e37cad03b1418897ea2295f81fc7
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/181204
Commit-Queue: Daco Harkes <[email protected]>
Auto-Submit: Daco Harkes <[email protected]>
Reviewed-by: Samuel Rawlins <[email protected]>
Reviewed-by: Siva Annamalai <[email protected]>

Author: dcharkes

pkg/analyzer/lib/src/generated/ffi_verifier.dart

@@ -775,7 +775,7 @@ class FfiVerifier extends RecursiveAstVisitor<void> {
   }
 
   void _validateRefIndexed(IndexExpression node) {
-    DartType targetType = node.target?.staticType;
+    DartType targetType = node.realTarget?.staticType;
     if (!_isValidFfiNativeType(targetType, false, true)) {
       final AstNode errorNode = node;
       _errorReporter.reportErrorForNode(
@@ -795,7 +795,7 @@ class FfiVerifier extends RecursiveAstVisitor<void> {
   }
 
   void _validateRefPropertyAccess(PropertyAccess node) {
-    DartType targetType = node.target?.staticType;
+    DartType targetType = node.realTarget?.staticType;
     if (!_isValidFfiNativeType(targetType, false, true)) {
       final AstNode errorNode = node;
       _errorReporter.reportErrorForNode(

pkg/analyzer/lib/src/test_utilities/mock_sdk.dart

@@ -661,6 +661,8 @@ class Double extends NativeType {
 }
 
 class Pointer<T extends NativeType> extends NativeType {
+  external factory Pointer.fromAddress(int ptr);
+
   static Pointer<NativeFunction<T>> fromFunction<T extends Function>(
       @DartRepresentationOf("T") Function f,
       [Object exceptionalReturn]) {}
@@ -685,6 +687,12 @@ abstract class NativeFunction<T extends Function> extends NativeType {}
 class DartRepresentationOf {
   const DartRepresentationOf(String nativeType);
 }
+
+extension StructPointer<T extends Struct> on Pointer<T> {
+  external T get ref;
+
+  external T operator [](int index);
+}
 ''',
   )
 ]);

pkg/analyzer/test/src/diagnostics/non_constant_type_argument_test.dart

@@ -9,10 +9,52 @@ import '../dart/resolution/context_collection_resolution.dart';
 
 main() {
   defineReflectiveSuite(() {
+    defineReflectiveTests(NonConstantTypeArgumentNoWarningTest);
+    defineReflectiveTests(NonConstantTypeArgumentNoWarningTest2);
     defineReflectiveTests(NonConstantTypeArgumentTest);
+    defineReflectiveTests(NonConstantTypeArgumentWarningTest);
   });
 }
 
+@reflectiveTest
+class NonConstantTypeArgumentNoWarningTest extends PubPackageResolutionTest {
+  test_asFunction_R() async {
+    await assertNoErrorsInCode(r'''
+import 'dart:ffi';
+
+class MyStruct extends Struct {
+  @Uint8()
+  int myField;
+}
+
+void main(){
+  final pointer = Pointer<MyStruct>.fromAddress(0);
+  pointer.ref.myField = 1;
+}
+''');
+  }
+}
+
+@reflectiveTest
+class NonConstantTypeArgumentNoWarningTest2 extends PubPackageResolutionTest {
+  test_asFunction_R() async {
+    await assertNoErrorsInCode(r'''
+import 'dart:ffi';
+
+class MyStruct extends Struct {
+  @Uint8()
+  int myField;
+}
+
+void main(){
+  final pointer = Pointer<MyStruct>.fromAddress(0)
+    ..ref.myField = 1;
+  print(pointer);
+}
+''');
+  }
+}
+
 @reflectiveTest
 class NonConstantTypeArgumentTest extends PubPackageResolutionTest {
   test_asFunction_R() async {
@@ -29,3 +71,15 @@ class C<R extends int Function(int)> {
     ]);
   }
 }
+
+@reflectiveTest
+class NonConstantTypeArgumentWarningTest extends PubPackageResolutionTest {
+  test_asFunction_R() async {
+    await assertErrorsInCode(r'''
+import 'dart:ffi';
+
+T genericRef<T extends Struct>(Pointer<T> p) =>
+    p.ref;
+''', [error(FfiCode.NON_CONSTANT_TYPE_ARGUMENT_WARNING, 72, 5)]);
+  }
+}

pkg/analyzer/test/src/diagnostics/subtype_of_ffi_class_test.dart

@@ -75,7 +75,9 @@ class C extends Int8 {}
   test_Pointer() async {
     await assertErrorsInCode(r'''
 import 'dart:ffi';
-class C extends Pointer {}
+class C extends Pointer {
+  external factory C();
+}
 ''', [
       error(FfiCode.SUBTYPE_OF_FFI_CLASS_IN_EXTENDS, 35, 7),
     ]);

tests/ffi/structs_test.dart

@@ -24,6 +24,7 @@ void main() {
     testBareStruct();
     testTypeTest();
     testUtf8();
+    testDotDotRef();
   }
 }
 
@@ -135,3 +136,10 @@ void testUtf8() {
   Expect.equals(test, Utf8.fromUtf8(medium));
   calloc.free(medium);
 }
+
+void testDotDotRef() {
+  final pointer = calloc<Coordinate>()
+    ..ref.x = 1
+    ..ref.y = 1;
+  calloc.free(pointer);
+}

tests/ffi_2/structs_test.dart

@@ -24,6 +24,7 @@ void main() {
     testBareStruct();
     testTypeTest();
     testUtf8();
+    testDotDotRef();
   }
 }
 
@@ -135,3 +136,10 @@ void testUtf8() {
   Expect.equals(test, Utf8.fromUtf8(medium));
   calloc.free(medium);
 }
+
+void testDotDotRef() {
+  final pointer = calloc<Coordinate>()
+    ..ref.x = 1
+    ..ref.y = 1;
+  calloc.free(pointer);
+}