[vm/ffi] Support inline arrays in Structs

Adds support for single dimension inline arrays in structs. Multi-
dimensional arrays will be supported in a future CL.

This CL adds:
- CFE static error checks for inline arrays.
- CFE transformations for inline arrays.
- VM consumption of inline array fields for NativeType.
- Test generator support for inline arrays + generated tests.

Previous CLs added support for inline arrays in:
- analyzer https://dart-review.googlesource.com/c/sdk/+/183684
  - updated in this CL to new API.
- ABI calculation https://dart-review.googlesource.com/c/sdk/+/183682

Closes: #35763

Open issue: #45101

CFE transformations are tested with expectation files:
TEST=pkg/front_end/testcases/(.*)/ffi_struct_inline_array.dart

Trampolines and CArray API are tested with end-to-end Dart tests:
TEST=tests/ffi(_2)/(.*)by_value(.*)test.dart
TEST=tests/ffi(_2)/inline_array_test.dart

Compile-time errors (both CFE and analyzer) are tested in:
TEST=tests/ffi(_2)/vmspecific_static_checks_test.dart

Change-Id: I014c0e4153f1b885638adce80de6ab3cac8e6bb2
Cq-Include-Trybots: luci.dart.try:dart-sdk-linux-try,dart-sdk-mac-try,dart-sdk-win-try,vm-ffi-android-debug-arm-try,vm-ffi-android-debug-arm64-try,vm-kernel-asan-linux-release-x64-try,vm-kernel-mac-debug-x64-try,vm-kernel-linux-debug-ia32-try,vm-kernel-linux-debug-x64-try,vm-kernel-nnbd-linux-debug-x64-try,vm-kernel-nnbd-linux-debug-ia32-try,vm-kernel-nnbd-mac-release-x64-try,vm-kernel-nnbd-win-debug-x64-try,vm-kernel-precomp-linux-debug-x64-try,vm-kernel-precomp-linux-debug-simarm_x64-try,vm-kernel-precomp-nnbd-linux-debug-x64-try,vm-kernel-precomp-win-release-x64-try,vm-kernel-reload-linux-debug-x64-try,vm-kernel-reload-rollback-linux-debug-x64-try,vm-kernel-win-debug-x64-try,vm-kernel-win-debug-ia32-try,vm-precomp-ffi-qemu-linux-release-arm-try,vm-kernel-precomp-obfuscate-linux-release-x64-try,vm-kernel-msan-linux-release-x64-try,vm-kernel-precomp-msan-linux-release-x64-try,vm-kernel-precomp-android-release-arm_x64-try,analyzer-analysis-server-linux-try
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/183640
Commit-Queue: Daco Harkes <dacoharkes@google.com>
Reviewed-by: Martin Kustermann <kustermann@google.com>
Reviewed-by: Clement Skau <cskau@google.com>

pkg/_fe_analyzer_shared/lib/src/messages/codes_generated.dart

@@ -3903,6 +3903,28 @@ Message _withArgumentsFfiNotStatic(String name) {
       arguments: {'name': name});
 }
 
+// DO NOT EDIT. THIS FILE IS GENERATED. SEE TOP OF FILE.
+const Template<Message Function(String name)> templateFfiSizeAnnotation =
+    const Template<Message Function(String name)>(
+        messageTemplate:
+            r"""Field '#name' must have exactly one 'Array' annotation.""",
+        withArguments: _withArgumentsFfiSizeAnnotation);
+
+// DO NOT EDIT. THIS FILE IS GENERATED. SEE TOP OF FILE.
+const Code<Message Function(String name)> codeFfiSizeAnnotation =
+    const Code<Message Function(String name)>(
+  "FfiSizeAnnotation",
+);
+
+// DO NOT EDIT. THIS FILE IS GENERATED. SEE TOP OF FILE.
+Message _withArgumentsFfiSizeAnnotation(String name) {
+  if (name.isEmpty) throw 'No name provided';
+  name = demangleMixinApplicationName(name);
+  return new Message(codeFfiSizeAnnotation,
+      message: """Field '${name}' must have exactly one 'Array' annotation.""",
+      arguments: {'name': name});
+}
+
 // DO NOT EDIT. THIS FILE IS GENERATED. SEE TOP OF FILE.
 const Template<Message Function(String name)> templateFfiStructGeneric =
     const Template<Message Function(String name)>(

pkg/analyzer/lib/src/dart/error/ffi_code.dart

@@ -44,7 +44,7 @@ class FfiCode extends AnalyzerErrorCode {
    */
   static const FfiCode EXTRA_SIZE_ANNOTATION_CARRAY = FfiCode(
       name: 'EXTRA_SIZE_ANNOTATION_CARRAY',
-      message: "'CArray's must have exactly one 'CArraySize' annotation.",
+      message: "'Array's must have exactly one 'Array' annotation.",
       correction: "Try removing the extra annotation.");
 
   /**
@@ -94,10 +94,10 @@ class FfiCode extends AnalyzerErrorCode {
       name: 'INVALID_FIELD_TYPE_IN_STRUCT',
       message:
           "Fields in struct classes can't have the type '{0}'. They can only "
-          "be declared as 'int', 'double', 'CArray', 'Pointer', or subtype of "
+          "be declared as 'int', 'double', 'Array', 'Pointer', or subtype of "
           "'Struct'.",
       correction:
-          "Try using 'int', 'double', 'CArray', 'Pointer', or subtype of "
+          "Try using 'int', 'double', 'Array', 'Pointer', or subtype of "
           "'Struct'.");
 
   /**
@@ -146,8 +146,8 @@ class FfiCode extends AnalyzerErrorCode {
    */
   static const FfiCode MISSING_SIZE_ANNOTATION_CARRAY = FfiCode(
       name: 'MISSING_SIZE_ANNOTATION_CARRAY',
-      message: "'CArray's must have exactly one 'CArraySize' annotation.",
-      correction: "Try adding a 'CArraySize' annotation.");
+      message: "'Array's must have exactly one 'Array' annotation.",
+      correction: "Try adding a 'Array' annotation.");
 
   /**
    * Parameters:

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

@@ -18,7 +18,7 @@ class FfiVerifier extends RecursiveAstVisitor<void> {
   static const _allocatorClassName = 'Allocator';
   static const _allocateExtensionMethodName = 'call';
   static const _allocatorExtensionName = 'AllocatorAlloc';
-  static const _cArrayClassName = 'CArray';
+  static const _cArrayClassName = 'Array';
   static const _dartFfiLibraryName = 'dart.ffi';
   static const _opaqueClassName = 'Opaque';
 
@@ -159,7 +159,7 @@ class FfiVerifier extends RecursiveAstVisitor<void> {
     if (element is MethodElement) {
       var enclosingElement = element.enclosingElement;
       if (enclosingElement.isNativeStructPointerExtension ||
-          enclosingElement.isNativeStructCArrayExtension) {
+          enclosingElement.isNativeStructArrayExtension) {
         if (element.name == '[]') {
           _validateRefIndexed(node);
         }
@@ -279,7 +279,7 @@ class FfiVerifier extends RecursiveAstVisitor<void> {
   bool _isValidFfiNativeType(DartType? nativeType,
       {bool allowVoid = false,
       bool allowEmptyStruct = false,
-      bool allowCArray = false}) {
+      bool allowArray = false}) {
     if (nativeType is InterfaceType) {
       // Is it a primitive integer/double type (or ffi.Void if we allow it).
       final primitiveType = _primitiveNativeType(nativeType);
@@ -310,7 +310,7 @@ class FfiVerifier extends RecursiveAstVisitor<void> {
       if (nativeType.isOpaqueSubtype) {
         return true;
       }
-      if (allowCArray && nativeType.isCArray) {
+      if (allowArray && nativeType.isArray) {
         return _isValidFfiNativeType(nativeType.typeArguments.single,
             allowVoid: false, allowEmptyStruct: false);
       }
@@ -550,7 +550,7 @@ class FfiVerifier extends RecursiveAstVisitor<void> {
         _validateAnnotations(fieldType, annotations, _PrimitiveDartType.double);
       } else if (declaredType.isPointer) {
         _validateNoAnnotations(annotations);
-      } else if (declaredType.isCArray) {
+      } else if (declaredType.isArray) {
         final typeArg = (declaredType as InterfaceType).typeArguments.single;
         if (!_isSized(typeArg)) {
           _errorReporter.reportErrorForNode(FfiCode.NON_SIZED_TYPE_ARGUMENT,
@@ -663,7 +663,7 @@ class FfiVerifier extends RecursiveAstVisitor<void> {
   void _validateRefIndexed(IndexExpression node) {
     var targetType = node.realTarget.staticType;
     if (!_isValidFfiNativeType(targetType,
-        allowVoid: false, allowEmptyStruct: true, allowCArray: true)) {
+        allowVoid: false, allowEmptyStruct: true, allowArray: true)) {
       final AstNode errorNode = node;
       _errorReporter.reportErrorForNode(
           FfiCode.NON_CONSTANT_TYPE_ARGUMENT, errorNode, ['[]']);
@@ -714,7 +714,7 @@ class FfiVerifier extends RecursiveAstVisitor<void> {
       final element = annotation.element;
       return element is ConstructorElement &&
           element.ffiClass != null &&
-          element.enclosingElement.name == 'CArraySize';
+          element.enclosingElement.name == 'Array';
     }).toList();
 
     if (ffiSizeAnnotations.isEmpty) {
@@ -766,10 +766,10 @@ extension on Element? {
         element.isFfiExtension;
   }
 
-  bool get isNativeStructCArrayExtension {
+  bool get isNativeStructArrayExtension {
     final element = this;
     return element is ExtensionElement &&
-        element.name == 'StructCArray' &&
+        element.name == 'StructArray' &&
         element.isFfiExtension;
   }
 
@@ -821,7 +821,7 @@ extension on ClassElement {
         return false;
       } else if (declaredType.isStructSubtype) {
         return false;
-      } else if (declaredType.isCArray) {
+      } else if (declaredType.isArray) {
         return false;
       }
     }
@@ -840,8 +840,8 @@ extension on ExtensionElement {
 }
 
 extension on DartType {
-  /// Return `true` if this represents the class `CArray`.
-  bool get isCArray {
+  /// Return `true` if this represents the class `Array`.
+  bool get isArray {
     final self = this;
     if (self is InterfaceType) {
       final element = self.element;

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

@@ -690,12 +690,8 @@ class DartRepresentationOf {
   const DartRepresentationOf(String nativeType);
 }
 
-class CArray<T extends NativeType> extends NativeType {}
-
-class CArraySize {
-  final int numberOfElements;
-
-  const CArraySize(this.numberOfElements);
+class Array<T extends NativeType> extends NativeType {
+  external const factory Array(int dimension1);
 }
 
 extension StructPointer<T extends Struct> on Pointer<T> {

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

@@ -9,19 +9,19 @@ import '../dart/resolution/context_collection_resolution.dart';
 
 main() {
   defineReflectiveSuite(() {
-    defineReflectiveTests(ExtraSizeAnnotationCArray);
+    defineReflectiveTests(ExtraSizeAnnotationArray);
   });
 }
 
 @reflectiveTest
-class ExtraSizeAnnotationCArray extends PubPackageResolutionTest {
+class ExtraSizeAnnotationArray extends PubPackageResolutionTest {
   test_one() async {
     await assertNoErrorsInCode(r'''
 import 'dart:ffi';
 
 class C extends Struct {
-  @CArraySize(8)
-  CArray<Uint8> a0;
+  @Array(8)
+  Array<Uint8> a0;
 }
 ''');
   }
@@ -31,12 +31,12 @@ class C extends Struct {
 import 'dart:ffi';
 
 class C extends Struct {
-  @CArraySize(8)
-  @CArraySize(8)
-  CArray<Uint8> a0;
+  @Array(8)
+  @Array(8)
+  Array<Uint8> a0;
 }
 ''', [
-      error(FfiCode.EXTRA_SIZE_ANNOTATION_CARRAY, 64, 14),
+      error(FfiCode.EXTRA_SIZE_ANNOTATION_CARRAY, 59, 9),
     ]);
   }
 }

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

@@ -9,19 +9,19 @@ import '../dart/resolution/context_collection_resolution.dart';
 
 main() {
   defineReflectiveSuite(() {
-    defineReflectiveTests(MissingSizeAnnotationCArray);
+    defineReflectiveTests(MissingSizeAnnotationArray);
   });
 }
 
 @reflectiveTest
-class MissingSizeAnnotationCArray extends PubPackageResolutionTest {
+class MissingSizeAnnotationArray extends PubPackageResolutionTest {
   test_one() async {
     await assertNoErrorsInCode(r'''
 import 'dart:ffi';
 
 class C extends Struct {
-  @CArraySize(8)
-  CArray<Uint8> a0;
+  @Array(8)
+  Array<Uint8> a0;
 }
 ''');
   }
@@ -31,10 +31,10 @@ class C extends Struct {
 import 'dart:ffi';
 
 class C extends Struct {
-  CArray<Uint8> a0;
+  Array<Uint8> a0;
 }
 ''', [
-      error(FfiCode.MISSING_SIZE_ANNOTATION_CARRAY, 47, 13),
+      error(FfiCode.MISSING_SIZE_ANNOTATION_CARRAY, 47, 12),
     ]);
   }
 }

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

@@ -20,8 +20,8 @@ class NonSizedTypeArgument extends PubPackageResolutionTest {
 import 'dart:ffi';
 
 class C extends Struct {
-  @CArraySize(8)
-  CArray<Uint8> a0;
+  @Array(8)
+  Array<Uint8> a0;
 }
 ''');
   }
@@ -31,11 +31,11 @@ class C extends Struct {
 import 'dart:ffi';
 
 class C extends Struct {
-  @CArraySize(8)
-  CArray<CArray<Uint8>> a0;
+  @Array(8)
+  Array<Array<Uint8>> a0;
 }
 ''', [
-      error(FfiCode.NON_SIZED_TYPE_ARGUMENT, 64, 21),
+      error(FfiCode.NON_SIZED_TYPE_ARGUMENT, 59, 19),
     ]);
   }
 }

pkg/front_end/lib/src/api_unstable/vm.dart

@@ -64,6 +64,7 @@ export '../fasta/fasta_codes.dart'
         templateFfiFieldNoAnnotation,
         templateFfiFieldNull,
         templateFfiNotStatic,
+        templateFfiSizeAnnotation,
         templateFfiStructGeneric,
         templateFfiTypeInvalid,
         templateFfiTypeMismatch;

pkg/front_end/messages.status

@@ -329,6 +329,7 @@ FfiFieldInitializer/analyzerCode: Fail
 FfiFieldNoAnnotation/analyzerCode: Fail
 FfiFieldNull/analyzerCode: Fail
 FfiNotStatic/analyzerCode: Fail
+FfiSizeAnnotation/analyzerCode: Fail
 FfiStructAnnotation/analyzerCode: Fail
 FfiStructGeneric/analyzerCode: Fail
 FfiTypeInvalid/analyzerCode: Fail

pkg/front_end/messages.yaml

@@ -4263,6 +4263,11 @@ FfiExtendsOrImplementsSealedClass:
   template: "Class '#name' cannot be extended or implemented."
   external: test/ffi_test.dart
 
+FfiSizeAnnotation:
+  # Used by dart:ffi
+  template: "Field '#name' must have exactly one 'Array' annotation."
+  external: test/ffi_test.dart
+
 FfiStructGeneric:
   # Used by dart:ffi
   template: "Struct '#name' should not be generic."

pkg/front_end/testcases/nnbd/ffi_struct_inline_array.dart

@@ -0,0 +1,14 @@
+// Copyright (c) 2021, 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.
+
+import 'dart:ffi';
+
+import "package:ffi/ffi.dart";
+
+class StructInlineArray extends Struct {
+  @Array(8)
+  external Array<Uint8> a0;
+}
+
+main() {}

pkg/front_end/testcases/nnbd/ffi_struct_inline_array.dart.strong.expect

@@ -0,0 +1,27 @@
+library /*isNonNullableByDefault*/;
+import self as self;
+import "dart:ffi" as ffi;
+
+import "dart:ffi";
+import "package:ffi/ffi.dart";
+
+class StructInlineArray extends ffi::Struct {
+  synthetic constructor •() → self::StructInlineArray
+    : super ffi::Struct::•()
+    ;
+  @#C2
+  external get a0() → ffi::Array<ffi::Uint8>;
+  @#C2
+  external set a0(ffi::Array<ffi::Uint8> #externalFieldValue) → void;
+}
+static method main() → dynamic {}
+
+constants  {
+  #C1 = 8
+  #C2 = ffi::_ArraySize<ffi::NativeType> {dimension1:#C1}
+}
+
+
+Constructor coverage from constants:
+org-dartlang-testcase:///ffi_struct_inline_array.dart:
+- _ArraySize. (from org-dartlang-sdk:///sdk/lib/ffi/ffi.dart:107:9)