| // 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. |
| |
| library vm.transformations.ffi_definitions; |
| |
| import 'dart:math' as math; |
| |
| import 'package:front_end/src/api_unstable/vm.dart' |
| show |
| templateFfiFieldAnnotation, |
| templateFfiFieldNoAnnotation, |
| templateFfiTypeMismatch, |
| templateFfiFieldInitializer, |
| templateFfiStructGeneric; |
| |
| import 'package:kernel/ast.dart' hide MapEntry; |
| import 'package:kernel/class_hierarchy.dart' show ClassHierarchy; |
| import 'package:kernel/core_types.dart'; |
| import 'package:kernel/library_index.dart' show LibraryIndex; |
| import 'package:kernel/reference_from_index.dart'; |
| import 'package:kernel/target/changed_structure_notifier.dart'; |
| import 'package:kernel/target/targets.dart' show DiagnosticReporter; |
| import 'package:kernel/type_environment.dart' show SubtypeCheckMode; |
| |
| import 'ffi.dart'; |
| |
| /// Checks and elaborates the dart:ffi structs and fields. |
| /// |
| /// Input: |
| /// class Coord extends Struct { |
| /// @Double() |
| /// double x; |
| /// |
| /// @Double() |
| /// double y; |
| /// |
| /// Coord next; |
| /// } |
| /// |
| /// Output: |
| /// class Coord extends Struct { |
| /// Coord.#fromPointer(Pointer<Coord> coord) : super._(coord); |
| /// |
| /// Pointer<Double> get _xPtr => addressOf.cast(); |
| /// set x(double v) => _xPtr.store(v); |
| /// double get x => _xPtr.load(); |
| /// |
| /// Pointer<Double> get _yPtr => addressOf.offsetBy(...).cast(); |
| /// set y(double v) => _yPtr.store(v); |
| /// double get y => _yPtr.load(); |
| /// |
| /// ffi.Pointer<Coordinate> get _nextPtr => addressof.offsetBy(...).cast(); |
| /// set next(Coordinate v) => _nextPtr.store(v); |
| /// Coordinate get next => _nextPtr.load(); |
| /// |
| /// static final int #sizeOf = 24; |
| /// } |
| ReplacedMembers transformLibraries( |
| Component component, |
| CoreTypes coreTypes, |
| ClassHierarchy hierarchy, |
| List<Library> libraries, |
| DiagnosticReporter diagnosticReporter, |
| ReferenceFromIndex referenceFromIndex, |
| ChangedStructureNotifier changedStructureNotifier) { |
| final LibraryIndex index = |
| LibraryIndex(component, const ["dart:ffi", "dart:core"]); |
| if (!index.containsLibrary("dart:ffi")) { |
| // TODO: This check doesn't make sense: "dart:ffi" is always loaded/created |
| // for the VM target. |
| // If dart:ffi is not loaded, do not do the transformation. |
| return ReplacedMembers({}, {}); |
| } |
| if (index.tryGetClass('dart:ffi', 'NativeFunction') == null) { |
| // If dart:ffi is not loaded (for real): do not do the transformation. |
| return ReplacedMembers({}, {}); |
| } |
| final transformer = new _FfiDefinitionTransformer(index, coreTypes, hierarchy, |
| diagnosticReporter, referenceFromIndex, changedStructureNotifier); |
| libraries.forEach(transformer.visitLibrary); |
| return ReplacedMembers( |
| transformer.replacedGetters, transformer.replacedSetters); |
| } |
| |
| /// Checks and elaborates the dart:ffi structs and fields. |
| class _FfiDefinitionTransformer extends FfiTransformer { |
| final LibraryIndex index; |
| |
| Map<Field, Procedure> replacedGetters = {}; |
| Map<Field, Procedure> replacedSetters = {}; |
| |
| ChangedStructureNotifier changedStructureNotifier; |
| |
| IndexedLibrary currentLibraryIndex; |
| |
| _FfiDefinitionTransformer( |
| this.index, |
| CoreTypes coreTypes, |
| ClassHierarchy hierarchy, |
| DiagnosticReporter diagnosticReporter, |
| ReferenceFromIndex referenceFromIndex, |
| this.changedStructureNotifier) |
| : super(index, coreTypes, hierarchy, diagnosticReporter, |
| referenceFromIndex) {} |
| |
| @override |
| visitLibrary(Library node) { |
| currentLibraryIndex = referenceFromIndex?.lookupLibrary(node); |
| return super.visitLibrary(node); |
| } |
| |
| @override |
| visitExtension(Extension node) { |
| // The extension and it's members are only metadata. |
| return node; |
| } |
| |
| @override |
| visitClass(Class node) { |
| if (!hierarchy.isSubclassOf(node, structClass) || node == structClass) { |
| return node; |
| } |
| |
| _checkStructClass(node); |
| |
| // Struct objects are manufactured in the VM by 'allocate' and 'load'. |
| _makeEntryPoint(node); |
| |
| var indexedClass = currentLibraryIndex?.lookupIndexedClass(node.name); |
| _checkConstructors(node, indexedClass); |
| final bool fieldsValid = _checkFieldAnnotations(node); |
| |
| if (fieldsValid) { |
| final structSize = _replaceFields(node, indexedClass); |
| _replaceSizeOfMethod(node, structSize, indexedClass); |
| changedStructureNotifier?.registerClassMemberChange(node); |
| } |
| |
| return node; |
| } |
| |
| void _checkStructClass(Class node) { |
| if (node.typeParameters.length > 0) { |
| diagnosticReporter.report( |
| templateFfiStructGeneric.withArguments(node.name), |
| node.fileOffset, |
| 1, |
| node.location.file); |
| } |
| |
| if (node.supertype?.classNode != structClass) { |
| // Not a struct, but extends a struct. The error will be emitted by |
| // _FfiUseSiteTransformer. |
| return; |
| } |
| } |
| |
| bool _isPointerType(DartType type) { |
| return env.isSubtypeOf( |
| type, |
| InterfaceType(pointerClass, Nullability.legacy, [ |
| InterfaceType(nativeTypesClasses[NativeType.kNativeType.index], |
| Nullability.legacy) |
| ]), |
| SubtypeCheckMode.ignoringNullabilities); |
| } |
| |
| /// Returns members of [node] that correspond to struct fields. |
| /// |
| /// Note that getters and setters that originate from an external field have |
| /// the same `fileOffset`, we always returns getters first. |
| List<Member> _structFieldMembers(Class node) { |
| final externalGetterSetters = [...node.procedures] |
| ..retainWhere((p) => p.isExternal && (p.isGetter || p.isSetter)); |
| final structMembers = [...node.fields, ...externalGetterSetters] |
| ..sort((m1, m2) { |
| if (m1.fileOffset == m2.fileOffset) { |
| // Getter and setter have same offset, getter comes first. |
| return (m1 as Procedure).isGetter ? -1 : 1; |
| } |
| return m1.fileOffset - m2.fileOffset; |
| }); |
| return structMembers; |
| } |
| |
| DartType _structFieldMemberType(Member member) { |
| if (member is Field) { |
| return member.type; |
| } |
| final Procedure p = member; |
| if (p.isGetter) { |
| return p.function.returnType; |
| } |
| return p.function.positionalParameters.single.type; |
| } |
| |
| bool _checkFieldAnnotations(Class node) { |
| bool success = true; |
| final membersWithAnnotations = _structFieldMembers(node) |
| ..retainWhere((m) => (m is Field) || (m is Procedure && m.isGetter)); |
| for (final Member f in membersWithAnnotations) { |
| if (f is Field) { |
| if (f.initializer is! NullLiteral) { |
| diagnosticReporter.report( |
| templateFfiFieldInitializer.withArguments(f.name.text), |
| f.fileOffset, |
| f.name.text.length, |
| f.fileUri); |
| } |
| } |
| final nativeTypeAnnos = _getNativeTypeAnnotations(f).toList(); |
| final type = _structFieldMemberType(f); |
| if (_isPointerType(type)) { |
| if (nativeTypeAnnos.length != 0) { |
| diagnosticReporter.report( |
| templateFfiFieldNoAnnotation.withArguments(f.name.text), |
| f.fileOffset, |
| f.name.text.length, |
| f.fileUri); |
| } |
| } else if (nativeTypeAnnos.length != 1) { |
| diagnosticReporter.report( |
| templateFfiFieldAnnotation.withArguments(f.name.text), |
| f.fileOffset, |
| f.name.text.length, |
| f.fileUri); |
| } else { |
| final DartType nativeType = InterfaceType( |
| nativeTypesClasses[_getFieldType(nativeTypeAnnos.first).index], |
| Nullability.legacy); |
| // TODO(dartbug.com/37271): Support structs inside structs. |
| final DartType shouldBeDartType = convertNativeTypeToDartType( |
| nativeType, /*allowStructs=*/ false, /*allowHandle=*/ false); |
| if (shouldBeDartType == null || |
| !env.isSubtypeOf(type, shouldBeDartType, |
| SubtypeCheckMode.ignoringNullabilities)) { |
| diagnosticReporter.report( |
| templateFfiTypeMismatch.withArguments(type, shouldBeDartType, |
| nativeType, node.enclosingLibrary.isNonNullableByDefault), |
| f.fileOffset, |
| 1, |
| f.location.file); |
| success = false; |
| } |
| } |
| } |
| return success; |
| } |
| |
| void _checkConstructors(Class node, IndexedClass indexedClass) { |
| final toRemove = <Initializer>[]; |
| |
| // Constructors cannot have initializers because initializers refer to |
| // fields, and the fields were replaced with getter/setter pairs. |
| for (final Constructor c in node.constructors) { |
| for (final Initializer i in c.initializers) { |
| if (i is FieldInitializer) { |
| toRemove.add(i); |
| diagnosticReporter.report( |
| templateFfiFieldInitializer.withArguments(i.field.name.text), |
| i.fileOffset, |
| 1, |
| i.location.file); |
| } |
| } |
| } |
| // Remove initializers referring to fields to prevent cascading errors. |
| for (final Initializer i in toRemove) { |
| i.remove(); |
| } |
| |
| // Add a constructor which 'load' can use. |
| // C.#fromPointer(Pointer<Void> address) : super.fromPointer(address); |
| final VariableDeclaration pointer = new VariableDeclaration("#pointer"); |
| final name = Name("#fromPointer"); |
| final referenceFrom = indexedClass?.lookupConstructor(name.text); |
| final Constructor ctor = Constructor( |
| FunctionNode(EmptyStatement(), positionalParameters: [pointer]), |
| name: name, |
| initializers: [ |
| SuperInitializer(structFromPointer, Arguments([VariableGet(pointer)])) |
| ], |
| fileUri: node.fileUri, |
| reference: referenceFrom?.reference) |
| ..fileOffset = node.fileOffset |
| ..isNonNullableByDefault = node.enclosingLibrary.isNonNullableByDefault; |
| _makeEntryPoint(ctor); |
| node.addConstructor(ctor); |
| } |
| |
| /// Computes the field offsets (for all ABIs) in the struct and replaces the |
| /// fields with getters and setters using these offsets. |
| /// |
| /// Returns the total size of the struct (for all ABIs). |
| Map<Abi, int> _replaceFields(Class node, IndexedClass indexedClass) { |
| final classes = <Class>[]; |
| final types = <NativeType>[]; |
| final fields = <int, Field>{}; |
| final getters = <int, Procedure>{}; |
| final setters = <int, Procedure>{}; |
| |
| int i = 0; |
| for (final Member m in _structFieldMembers(node)) { |
| final dartType = _structFieldMemberType(m); |
| |
| NativeType nativeType; |
| Class clazz; |
| if (_isPointerType(dartType)) { |
| nativeType = NativeType.kPointer; |
| clazz = pointerClass; |
| } else { |
| final nativeTypeAnnos = _getNativeTypeAnnotations(m).toList(); |
| if (nativeTypeAnnos.length == 1) { |
| clazz = nativeTypeAnnos.first; |
| nativeType = _getFieldType(clazz); |
| } |
| } |
| |
| if ((m is Field || (m is Procedure && m.isGetter)) && |
| nativeType != null) { |
| types.add(nativeType); |
| classes.add(clazz); |
| if (m is Field) { |
| fields[i] = m; |
| } |
| if (m is Procedure) { |
| getters[i] = m; |
| } |
| i++; |
| } |
| if (m is Procedure && m.isSetter) { |
| final index = i - 1; // The corresponding getter's index. |
| if (getters.containsKey(index)) { |
| setters[i - 1] = m; |
| } |
| } |
| } |
| |
| _annoteStructWithFields(node, classes); |
| |
| final sizeAndOffsets = <Abi, SizeAndOffsets>{}; |
| for (final Abi abi in Abi.values) { |
| sizeAndOffsets[abi] = _calculateSizeAndOffsets(types, abi); |
| } |
| |
| for (final i in fields.keys) { |
| final fieldOffsets = sizeAndOffsets |
| .map((Abi abi, SizeAndOffsets v) => MapEntry(abi, v.offsets[i])); |
| final methods = _generateMethodsForField( |
| fields[i], types[i], fieldOffsets, indexedClass); |
| methods.forEach((p) => node.addProcedure(p)); |
| } |
| |
| for (final Field f in fields.values) { |
| f.remove(); |
| } |
| |
| for (final i in getters.keys) { |
| final fieldOffsets = sizeAndOffsets |
| .map((Abi abi, SizeAndOffsets v) => MapEntry(abi, v.offsets[i])); |
| Procedure getter = getters[i]; |
| getter.function.body = _generateGetterStatement( |
| getter.function.returnType, |
| types[i], |
| getter.fileOffset, |
| fieldOffsets); |
| getter.isExternal = false; |
| } |
| |
| for (final i in setters.keys) { |
| final fieldOffsets = sizeAndOffsets |
| .map((Abi abi, SizeAndOffsets v) => MapEntry(abi, v.offsets[i])); |
| Procedure setter = setters[i]; |
| setter.function.body = _generateSetterStatement( |
| setter.function.positionalParameters.single.type, |
| types[i], |
| setter.fileOffset, |
| fieldOffsets, |
| setter.function.positionalParameters.single); |
| setter.isExternal = false; |
| } |
| |
| return sizeAndOffsets.map((k, v) => MapEntry(k, v.size)); |
| } |
| |
| void _annoteStructWithFields(Class node, List<Class> fieldTypes) { |
| final types = fieldTypes.map((Class c) { |
| List<DartType> typeArg = const []; |
| if (c == pointerClass) { |
| typeArg = [ |
| InterfaceType(pointerClass.superclass, Nullability.nonNullable) |
| ]; |
| } |
| return TypeLiteralConstant( |
| InterfaceType(c, Nullability.nonNullable, typeArg)); |
| }).toList(); |
| |
| node.addAnnotation(ConstantExpression( |
| InstanceConstant(pragmaClass.reference, [], { |
| pragmaName.getterReference: StringConstant("vm:ffi:struct-fields"), |
| // TODO(dartbug.com/38158): Wrap list in class to be able to encode |
| // more information when needed. |
| pragmaOptions.getterReference: ListConstant( |
| InterfaceType(typeClass, Nullability.nonNullable), types) |
| }), |
| InterfaceType(pragmaClass, Nullability.nonNullable, []))); |
| } |
| |
| /// Expression that queries VM internals at runtime to figure out on which ABI |
| /// we are. |
| Expression _runtimeBranchOnLayout(Map<Abi, int> values) { |
| return MethodInvocation( |
| ConstantExpression( |
| ListConstant(InterfaceType(intClass, Nullability.legacy), [ |
| IntConstant(values[Abi.wordSize64]), |
| IntConstant(values[Abi.wordSize32Align32]), |
| IntConstant(values[Abi.wordSize32Align64]) |
| ]), |
| InterfaceType(listClass, Nullability.legacy, |
| [InterfaceType(intClass, Nullability.legacy)])), |
| Name("[]"), |
| Arguments([StaticInvocation(abiMethod, Arguments([]))]), |
| listElementAt); |
| } |
| |
| Statement _generateGetterStatement(DartType dartType, NativeType type, |
| int fileOffset, Map<Abi, int> offsets) { |
| final bool isPointer = type == NativeType.kPointer; |
| |
| // Sample output: |
| // int get x => _loadInt8(pointer, offset); |
| // |
| // Treat Pointer fields different to get correct behavior without casts: |
| // Pointer<Int8> get x => |
| // _fromAddress<Int8>(_loadIntPtr(pointer, offset)); |
| final loadMethod = isPointer |
| ? loadMethods[NativeType.kIntptr] |
| : optimizedTypes.contains(type) |
| ? loadMethods[type] |
| : loadStructMethod; |
| Expression getterReturnValue = StaticInvocation( |
| loadMethod, |
| Arguments([ |
| PropertyGet(ThisExpression(), addressOfField.name, addressOfField) |
| ..fileOffset = fileOffset, |
| _runtimeBranchOnLayout(offsets) |
| ])) |
| ..fileOffset = fileOffset; |
| if (isPointer) { |
| final typeArg = (dartType as InterfaceType).typeArguments.single; |
| getterReturnValue = StaticInvocation( |
| fromAddressInternal, Arguments([getterReturnValue], types: [typeArg])) |
| ..fileOffset = fileOffset; |
| } |
| return ReturnStatement(getterReturnValue); |
| } |
| |
| Statement _generateSetterStatement(DartType dartType, NativeType type, |
| int fileOffset, Map<Abi, int> offsets, VariableDeclaration argument) { |
| final bool isPointer = type == NativeType.kPointer; |
| |
| // Sample output: |
| // set x(int v) => _storeInt8(pointer, offset, v); |
| // |
| // Treat Pointer fields different to get correct behavior without casts: |
| // set x(Pointer<Int8> v) => |
| // _storeIntPtr(pointer, offset, (v as Pointer<Int8>).address); |
| final storeMethod = |
| isPointer ? storeMethods[NativeType.kIntptr] : storeMethods[type]; |
| Expression argumentExpression = VariableGet(argument) |
| ..fileOffset = fileOffset; |
| if (isPointer) { |
| argumentExpression = |
| PropertyGet(argumentExpression, addressGetter.name, addressGetter) |
| ..fileOffset = fileOffset; |
| } |
| return ReturnStatement(StaticInvocation( |
| storeMethod, |
| Arguments([ |
| PropertyGet(ThisExpression(), addressOfField.name, addressOfField) |
| ..fileOffset = fileOffset, |
| _runtimeBranchOnLayout(offsets), |
| argumentExpression |
| ])) |
| ..fileOffset = fileOffset); |
| } |
| |
| List<Procedure> _generateMethodsForField(Field field, NativeType type, |
| Map<Abi, int> offsets, IndexedClass indexedClass) { |
| final getterStatement = |
| _generateGetterStatement(field.type, type, field.fileOffset, offsets); |
| final Procedure getter = Procedure(field.name, ProcedureKind.Getter, |
| FunctionNode(getterStatement, returnType: field.type), |
| fileUri: field.fileUri, |
| reference: |
| indexedClass?.lookupProcedureNotSetter(field.name.text)?.reference) |
| ..fileOffset = field.fileOffset |
| ..isNonNullableByDefault = field.isNonNullableByDefault; |
| |
| Procedure setter = null; |
| if (!field.isFinal) { |
| final VariableDeclaration argument = |
| VariableDeclaration('#v', type: field.type) |
| ..fileOffset = field.fileOffset; |
| final setterStatement = _generateSetterStatement( |
| field.type, type, field.fileOffset, offsets, argument); |
| setter = Procedure( |
| field.name, |
| ProcedureKind.Setter, |
| FunctionNode(setterStatement, |
| returnType: VoidType(), positionalParameters: [argument]), |
| fileUri: field.fileUri, |
| reference: |
| indexedClass?.lookupProcedureSetter(field.name.text)?.reference) |
| ..fileOffset = field.fileOffset |
| ..isNonNullableByDefault = field.isNonNullableByDefault; |
| } |
| |
| replacedGetters[field] = getter; |
| replacedSetters[field] = setter; |
| |
| return [getter, if (setter != null) setter]; |
| } |
| |
| /// Sample output: |
| /// static int #sizeOf() => 24; |
| void _replaceSizeOfMethod( |
| Class struct, Map<Abi, int> sizes, IndexedClass indexedClass) { |
| var name = Name("#sizeOf"); |
| var lookupField = indexedClass?.lookupField(name.text); |
| final Field sizeOf = Field(name, |
| isStatic: true, |
| isFinal: true, |
| initializer: _runtimeBranchOnLayout(sizes), |
| type: InterfaceType(intClass, Nullability.legacy), |
| fileUri: struct.fileUri, |
| getterReference: lookupField?.getterReference, |
| setterReference: lookupField?.setterReference) |
| ..fileOffset = struct.fileOffset; |
| _makeEntryPoint(sizeOf); |
| struct.addField(sizeOf); |
| } |
| |
| int _sizeInBytes(NativeType type, Abi abi) { |
| final int size = nativeTypeSizes[type.index]; |
| if (size == WORD_SIZE) { |
| return wordSize[abi]; |
| } |
| return size; |
| } |
| |
| int _alignmentOf(NativeType type, Abi abi) { |
| final int alignment = nonSizeAlignment[abi][type]; |
| if (alignment != null) return alignment; |
| return _sizeInBytes(type, abi); |
| } |
| |
| int _alignOffset(int offset, int alignment) { |
| final int remainder = offset % alignment; |
| if (remainder != 0) { |
| offset -= remainder; |
| offset += alignment; |
| } |
| return offset; |
| } |
| |
| // TODO(37271): Support nested structs. |
| SizeAndOffsets _calculateSizeAndOffsets(List<NativeType> types, Abi abi) { |
| int offset = 0; |
| final offsets = <int>[]; |
| for (final NativeType t in types) { |
| final int size = _sizeInBytes(t, abi); |
| final int alignment = _alignmentOf(t, abi); |
| offset = _alignOffset(offset, alignment); |
| offsets.add(offset); |
| offset += size; |
| } |
| final int minimumAlignment = 1; |
| final sizeAlignment = types |
| .map((t) => _alignmentOf(t, abi)) |
| .followedBy([minimumAlignment]).reduce(math.max); |
| final int size = _alignOffset(offset, sizeAlignment); |
| return SizeAndOffsets(size, offsets); |
| } |
| |
| void _makeEntryPoint(Annotatable node) { |
| node.addAnnotation(ConstantExpression( |
| InstanceConstant(pragmaClass.reference, [], { |
| pragmaName.getterReference: StringConstant("vm:entry-point"), |
| pragmaOptions.getterReference: NullConstant() |
| }), |
| InterfaceType(pragmaClass, Nullability.legacy, []))); |
| } |
| |
| NativeType _getFieldType(Class c) { |
| final fieldType = getType(c); |
| |
| if (fieldType == NativeType.kVoid) { |
| // Fields cannot have Void types. |
| return null; |
| } |
| return fieldType; |
| } |
| |
| Iterable<Class> _getNativeTypeAnnotations(Member node) { |
| return node.annotations |
| .whereType<ConstantExpression>() |
| .map((expr) => expr.constant) |
| .whereType<InstanceConstant>() |
| .map((constant) => constant.classNode) |
| .where((klass) => _getFieldType(klass) != null); |
| } |
| } |
| |
| class SizeAndOffsets { |
| /// Size of the entire struct. |
| final int size; |
| |
| /// Offset in bytes for each field, indexed by field number. |
| final List<int> offsets; |
| |
| SizeAndOffsets(this.size, this.offsets); |
| } |