[cfe][analyzer] Add metadata parser

This adds a shared metadata parser to be used for macros. The parser
create a new AST which supports unresolved ASTs and delayed AST resolution.
An id-test is added for the generated AST from both CFE and analyzer.

Change-Id: Ie51817493fa6e668727a7af3a55cd22e2be722b3
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/391100
Reviewed-by: Konstantin Shcheglov <[email protected]>
Reviewed-by: Jens Johansen <[email protected]>
Commit-Queue: Johnni Winther <[email protected]>

Author: johnniwinther

pkg/_fe_analyzer_shared/analysis_options_no_lints.yaml

@@ -20,3 +20,4 @@ analyzer:
     - test/inference/inferred_type_arguments/data/**
     - test/inference/inferred_variable_types/data/**
     - test/inheritance/data/**
+    - test/metadata/data/**

pkg/_fe_analyzer_shared/lib/src/metadata/arguments.dart

@@ -0,0 +1,49 @@
+// Copyright (c) 2024, 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 'expressions.dart';
+import 'proto.dart';
+
+/// Superclass for named and position arguments.
+// TODO(johnniwinther): Merge subclasses into one class?
+sealed class Argument {
+  /// Returns the [Argument] corresponding to this [Argument] in
+  /// which all [UnresolvedIdentifier]s have been resolved within their scope.
+  ///
+  /// If this didn't create a new [Argument], `null` is returned.
+  Argument? resolve();
+}
+
+class PositionalArgument extends Argument {
+  final Expression expression;
+
+  PositionalArgument(this.expression);
+
+  @override
+  String toString() => 'PositionalArgument($expression)';
+
+  @override
+  Argument? resolve() {
+    Expression? newExpression = expression.resolve();
+    return newExpression == null ? null : new PositionalArgument(newExpression);
+  }
+}
+
+class NamedArgument extends Argument {
+  final String name;
+  final Expression expression;
+
+  NamedArgument(this.name, this.expression);
+
+  @override
+  String toString() => 'NamedArgument($name,$expression)';
+
+  @override
+  Argument? resolve() {
+    Expression? newExpression = expression.resolve();
+    return newExpression == null
+        ? null
+        : new NamedArgument(name, newExpression);
+  }
+}

pkg/_fe_analyzer_shared/lib/src/metadata/ast.dart

@@ -0,0 +1,13 @@
+// Copyright (c) 2024, 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.
+
+export 'arguments.dart';
+export 'elements.dart';
+export 'expressions.dart';
+export 'formal_parameters.dart';
+export 'proto.dart';
+export 'record_fields.dart';
+export 'references.dart';
+export 'string_literal_parts.dart';
+export 'type_annotations.dart';

pkg/_fe_analyzer_shared/lib/src/metadata/elements.dart

@@ -0,0 +1,104 @@
+// Copyright (c) 2024, 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 'expressions.dart';
+import 'proto.dart';
+
+/// Superclass for collection elements.
+sealed class Element {
+  /// Returns the [Element] corresponding to this [Element] in
+  /// which all [UnresolvedIdentifier]s have been resolved within their scope.
+  ///
+  /// If this didn't create a new [Element], `null` is returned.
+  Element? resolve();
+}
+
+class ExpressionElement extends Element {
+  final Expression expression;
+  final bool isNullAware;
+
+  ExpressionElement(this.expression, {required this.isNullAware});
+
+  @override
+  String toString() =>
+      'ExpressionElement($expression,isNullAware=$isNullAware)';
+
+  @override
+  Element? resolve() {
+    Expression? newExpression = expression.resolve();
+    return newExpression == null
+        ? null
+        : new ExpressionElement(newExpression, isNullAware: isNullAware);
+  }
+}
+
+class MapEntryElement extends Element {
+  final Expression key;
+  final Expression value;
+  final bool isNullAwareKey;
+  final bool isNullAwareValue;
+
+  MapEntryElement(this.key, this.value,
+      {required this.isNullAwareKey, required this.isNullAwareValue});
+
+  @override
+  String toString() => 'MapEntryElement($key,$value,'
+      'isNullAwareKey=$isNullAwareValue,isNullAwareValue=$isNullAwareValue)';
+
+  @override
+  Element? resolve() {
+    Expression? newKey = key.resolve();
+    Expression? newValue = value.resolve();
+    return newKey == null && newValue == null
+        ? null
+        : new MapEntryElement(newKey ?? key, newValue ?? value,
+            isNullAwareKey: isNullAwareKey, isNullAwareValue: isNullAwareValue);
+  }
+}
+
+class SpreadElement extends Element {
+  final Expression expression;
+  final bool isNullAware;
+
+  SpreadElement(this.expression, {required this.isNullAware});
+
+  @override
+  String toString() => 'SpreadElement($expression,isNullAware=$isNullAware)';
+
+  @override
+  Element? resolve() {
+    Expression? newExpression = expression.resolve();
+    return newExpression == null
+        ? null
+        : new SpreadElement(newExpression, isNullAware: isNullAware);
+  }
+}
+
+class IfElement extends Element {
+  final Expression condition;
+  final Element then;
+  final Element? otherwise;
+
+  IfElement(this.condition, this.then, [this.otherwise]);
+
+  @override
+  String toString() => 'IfElement($condition,$then,$otherwise)';
+
+  @override
+  Element? resolve() {
+    Expression? newCondition = condition.resolve();
+    Element? newThen = then.resolve();
+    Element? newOtherwise = otherwise?.resolve();
+    if (otherwise != null) {
+      return newCondition == null && newThen == null && newOtherwise == null
+          ? null
+          : new IfElement(newCondition ?? condition, newThen ?? then,
+              newOtherwise ?? otherwise);
+    } else {
+      return newCondition == null && newThen == null
+          ? null
+          : new IfElement(newCondition ?? condition, newThen ?? then);
+    }
+  }
+}