[cfe] Introduce Kernel AST node for the closure expreiment

Part of #61572

Change-Id: Iee3c2a223f4c44f5528016082cf3a068b401d87d
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/454061
Reviewed-by: Alexander Markov <alexmarkov@google.com>
Reviewed-by: Johnni Winther <johnniwinther@google.com>
Commit-Queue: Chloe Stefantsova <cstefantsova@google.com>

Author: chloestefantsova

pkg/front_end/lib/src/kernel/hierarchy/mixin_inferrer.dart

@@ -10,7 +10,7 @@ import 'package:kernel/type_algebra.dart';
 
 import '../../base/messages.dart'
     show Message, codeMixinInferenceNoMatchingClass;
-import '../../base/problems.dart' show unexpected, unsupported;
+import '../../base/problems.dart' show unexpected, unimplemented, unsupported;
 import '../../source/source_class_builder.dart';
 import '../../type_inference/type_schema.dart';
 
@@ -223,6 +223,15 @@ class BuilderMixinInferrer {
       classBuilder.fileUri,
     );
   }
+
+  // Coverage-ignore(suite): Not run.
+  Never reportUnimplementedProblem(String operation) {
+    return unimplemented(
+      operation,
+      classBuilder.fileOffset,
+      classBuilder.fileUri,
+    );
+  }
 }
 
 class _MixinInferenceSolution {
@@ -447,6 +456,22 @@ class _MixinInferenceSolution {
         } else {
           return <TypeParameter, DartType>{};
         }
+      case FunctionTypeParameterType():
+        // Coverage-ignore(suite): Not run.
+        // Type variable types are currently an experiment aren't fully
+        // implemented.
+        return unsupportedErrorReporter.reportUnimplementedProblem(
+          "_MixinInferenceSolution._solveForEquality"
+          "(${type1.runtimeType}, ${type2.runtimeType})",
+        );
+      case ClassTypeParameterType():
+        // Coverage-ignore(suite): Not run.
+        // Class type parameter types are currently an experiment aren't fully
+        // implemented.
+        return unsupportedErrorReporter.reportUnimplementedProblem(
+          "_MixinInferenceSolution._solveForEquality"
+          "(${type1.runtimeType}, ${type2.runtimeType})",
+        );
       case RecordType():
         // Coverage-ignore(suite): Not run.
         if (type2 is! RecordType) {

pkg/front_end/lib/src/kernel/internal_ast.dart

@@ -398,7 +398,7 @@ class Cascade extends InternalExpression {
       printer.newLine();
     }
     printer.write('} => ');
-    printer.write(printer.getVariableName(variable));
+    printer.write(printer.getVariableDeclarationName(variable));
   }
 }
 

pkg/front_end/lib/src/type_inference/inference_visitor.dart

@@ -26,7 +26,7 @@ import '../base/compiler_context.dart';
 import '../base/messages.dart';
 import '../base/problems.dart'
     as problems
-    show internalProblem, unhandled, unsupported;
+    show internalProblem, unhandled, unimplemented, unsupported;
 import '../base/uri_offset.dart';
 import '../builder/library_builder.dart';
 import '../dill/dill_library_builder.dart';
@@ -1100,6 +1100,20 @@ class InferenceVisitorImpl extends InferenceVisitorBase
           return _isIncompatibleWithAwait(type.parameter.bound);
         case IntersectionType():
           return _isIncompatibleWithAwait(type.right);
+        case FunctionTypeParameterType():
+          // Coverage-ignore(suite): Not run.
+          return problems.unimplemented(
+            "_isIncompatibleWithAwait(FunctionTypeParameterType)",
+            -1,
+            fileUri,
+          );
+        case ClassTypeParameterType():
+          // Coverage-ignore(suite): Not run.
+          return problems.unimplemented(
+            "_isIncompatibleWithAwait(ClassTypeParameterType)",
+            -1,
+            fileUri,
+          );
         case DynamicType():
         case VoidType():
         case FutureOrType():

pkg/front_end/test/spell_checking_list_common.txt

@@ -948,6 +948,7 @@ distinct
 distinction
 distinguish
 distinguishes
+distinguishing
 divide
 division
 divisor
@@ -1084,6 +1085,7 @@ enumeration
 enumerations
 enums
 environment
+environments
 equal
 equalities
 equality
@@ -1129,6 +1131,7 @@ examined
 examining
 example
 examples
+exceed
 exceeded
 except
 exception
@@ -2953,6 +2956,7 @@ spending
 split
 splits
 splitter
+spot
 spread
 spreadable
 spreads
@@ -3461,6 +3465,7 @@ visiting
 visitor
 visitor's
 visual
+visually
 vm
 void
 vowel

pkg/front_end/tool/ast_model.dart

@@ -148,6 +148,8 @@ const Map<String?, Map<String, FieldRule?>> _fieldRuleMap = {
   'VariablePattern': {'variable': FieldRule(isDeclaration: true)},
   'PatternSwitchCase': {'jointVariables': FieldRule(isDeclaration: true)},
   'PatternSwitchStatement': {'cases': FieldRule(isDeclaration: true)},
+  'TypeVariable': {'parameter': FieldRule(isDeclaration: false)},
+  'ClassTypeParameterType': {'parameter': FieldRule(isDeclaration: false)},
 };
 
 /// Data that determines exceptions to how fields are used.

pkg/kernel/lib/ast.dart

@@ -124,3 +124,4 @@ part 'src/ast/patterns.dart';
 part 'src/ast/statements.dart';
 part 'src/ast/typedefs.dart';
 part 'src/ast/types.dart';
+part 'src/ast/variables.dart';

pkg/kernel/lib/src/ast/expressions.dart

@@ -242,7 +242,7 @@ class VariableGet extends Expression {
 
   @override
   void toTextInternal(AstPrinter printer) {
-    printer.write(printer.getVariableName(variable));
+    printer.write(printer.getVariableDeclarationName(variable));
     if (promotedType != null) {
       printer.write('{');
       printer.writeType(promotedType!);
@@ -301,7 +301,7 @@ class VariableSet extends Expression {
 
   @override
   void toTextInternal(AstPrinter printer) {
-    printer.write(printer.getVariableName(variable));
+    printer.write(printer.getVariableDeclarationName(variable));
     printer.write(' = ');
     printer.writeExpression(value);
   }
@@ -2211,7 +2211,7 @@ class LocalFunctionInvocation extends InvocationExpression {
 
   @override
   void toTextInternal(AstPrinter printer) {
-    printer.write(printer.getVariableName(variable));
+    printer.write(printer.getVariableDeclarationName(variable));
     printer.writeArguments(arguments);
   }
 }
@@ -4764,10 +4764,13 @@ class Let extends Expression {
   }
 }
 
-class BlockExpression extends Expression {
+class BlockExpression extends Expression implements ScopeProvider {
   Block body;
   Expression value;
 
+  @override
+  Scope? scope;
+
   BlockExpression(this.body, this.value) {
     body.parent = this;
     value.parent = this;
@@ -5101,3 +5104,112 @@ class TypedefTearOff extends Expression {
     printer.write(")");
   }
 }
+
+/// [VariableRead] nodes are the replacement for the VariableGet nodes.
+///
+/// Despite of the  name, [VariableRead] can't read [TypeVariable]s,
+/// which are also [Variable]s.
+class VariableRead extends Expression {
+  final ExpressionVariable variable;
+
+  VariableRead({required this.variable});
+
+  @override
+  R accept<R>(ExpressionVisitor<R> v) {
+    // TODO(cstefantsova): Implement accept.
+    throw UnimplementedError();
+  }
+
+  @override
+  R accept1<R, A>(ExpressionVisitor1<R, A> v, A arg) {
+    // TODO(cstefantsova): Implement accept1.
+    throw UnimplementedError();
+  }
+
+  @override
+  DartType getStaticTypeInternal(StaticTypeContext context) {
+    // TODO(cstefantsova): Implement getStaticTypeInternal.
+    throw UnimplementedError();
+  }
+
+  @override
+  void transformChildren(Transformer v) {
+    // TODO(cstefantsova): Implement transformChildren.
+  }
+
+  @override
+  void transformOrRemoveChildren(RemovingTransformer v) {
+    // TODO(cstefantsova): Implement transformOrRemoveChildren.
+  }
+
+  @override
+  void visitChildren(Visitor v) {
+    // TODO(cstefantsova): Implement visitChildren.
+  }
+
+  @override
+  String toString() {
+    return "VariableRead(${toStringInternal()})";
+  }
+
+  @override
+  void toTextInternal(AstPrinter printer) {
+    printer.write(printer.getVariableName(variable));
+  }
+}
+
+/// [VariableWrite] nodes are the replacement for the VariableSet nodes.
+///
+/// Despite of the  name, [VariableWrite] can't write into
+/// [TypeVariable]s, which are also [Variable]s.
+class VariableWrite extends Expression {
+  final ExpressionVariable variable;
+  final Expression value;
+
+  VariableWrite({required this.variable, required this.value});
+
+  @override
+  R accept<R>(ExpressionVisitor<R> v) {
+    // TODO(cstefantsova): Implement accept.
+    throw UnimplementedError();
+  }
+
+  @override
+  R accept1<R, A>(ExpressionVisitor1<R, A> v, A arg) {
+    // TODO(cstefantsova): Implement accept1.
+    throw UnimplementedError();
+  }
+
+  @override
+  DartType getStaticTypeInternal(StaticTypeContext context) {
+    // TODO(cstefantsova): Implement getStaticTypeInternal.
+    throw UnimplementedError();
+  }
+
+  @override
+  void transformChildren(Transformer v) {
+    // TODO(cstefantsova): Implement transformChildren.
+  }
+
+  @override
+  void transformOrRemoveChildren(RemovingTransformer v) {
+    // TODO(cstefantsova): Implement transformOrRemoveChildren.
+  }
+
+  @override
+  void visitChildren(Visitor v) {
+    // TODO(cstefantsova): Implement visitChildren.
+  }
+
+  @override
+  String toString() {
+    return "VariableWrite(${toStringInternal()})";
+  }
+
+  @override
+  void toTextInternal(AstPrinter printer) {
+    printer.write(printer.getVariableName(variable));
+    printer.write(' = ');
+    printer.writeExpression(value);
+  }
+}

pkg/kernel/lib/src/ast/functions.dart

@@ -12,7 +12,7 @@ part of '../../ast.dart';
 ///
 /// This may occur in a procedure, constructor, function expression, or local
 /// function declaration.
-class FunctionNode extends TreeNode {
+class FunctionNode extends TreeNode implements ScopeProvider {
   /// End offset in the source file it comes from. Valid values are from 0 and
   /// up, or -1 ([TreeNode.noOffset]) if the file end offset is not available
   /// (this is the default if none is specifically set).
@@ -44,6 +44,9 @@ class FunctionNode extends TreeNode {
   DartType returnType; // Not null.
   Statement? _body;
 
+  @override
+  Scope? scope;
+
   /// The emitted value of non-sync functions
   ///
   /// For `async` functions [emittedValueType] is the future value type, that