[kernel][Contexts] Move initializer from VariableInitialization to Variable

This is a step back towards the end goal of separating Variable its initializer. This is done in order to normalize the encoding between the old and the new variable model, such that the split can be perform in both the old and new model simultaneously.

TEST=existing

Change-Id: I3ad6595613c06812d95dff3cabbca6eb05dc1c98
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/505000
Reviewed-by: Alexander Markov <alexmarkov@google.com>
Reviewed-by: Martin Kustermann <kustermann@google.com>
Commit-Queue: Johnni Winther <johnniwinther@google.com>
Reviewed-by: Chloe Stefantsova <cstefantsova@google.com>

pkg/dart2wasm/lib/await_transformer.dart

@@ -349,12 +349,14 @@ class _AwaitTransformer extends Transformer {
       VariableStatement decl = stmt.variables[i];
       temps.add(Variable(null, type: decl.variable.type, isSynthesized: true));
       loopBody.add(decl);
-      if (decl.initializer != null) {
+      if (decl.variable.initializer != null) {
         initializers.addAll(initEffects[i]);
         initializers.add(
-          ExpressionStatement(VariableSet(decl.variable, decl.initializer!)),
+          ExpressionStatement(
+            VariableSet(decl.variable, decl.variable.initializer!),
+          ),
         );
-        decl.initializer = null;
+        decl.variable.initializer = null;
       }
       updates.add(
         ExpressionStatement(

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

@@ -3405,6 +3405,7 @@ class BodyBuilderImpl extends StackListenerImpl
           isLate: isLate,
           isWildcard: isWildcard,
           fileOffset: identifier.nameOffset,
+          initializer: initializer,
         ),
         forSyntheticToken: identifier.token.isSynthetic,
         isImplicitlyTyped: currentLocalVariableType == null,
@@ -3412,7 +3413,7 @@ class BodyBuilderImpl extends StackListenerImpl
       );
       variableInitialization = intern.createVariableInitialization(
         variable: internalVariable.asVariableDeclaration,
-        initializer: initializer,
+
         hasDeclaredInitializer: initializer != null,
         fileOffset: offsetForToken(equalsToken),
       );
@@ -8354,7 +8355,7 @@ class BodyBuilderImpl extends StackListenerImpl
     if (lvalue is VariableInitialization) {
       // Variable initializers are not supported. An error has already been
       // reported by the parser.
-      lvalue.initializer = null;
+      lvalue.variable.initializer = null;
       lvalue.hasDeclaredInitializer = false;
       // Late for-in variables are not supported. An error has already been
       // reported by the parser.

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

@@ -606,6 +606,7 @@ LocalVariable createLocalVariable({
   bool isLate = false,
   bool isWildcard = false,
   required int fileOffset,
+  Expression? initializer,
 }) {
   return new LocalVariable(
     cosmeticName: cosmeticName,
@@ -614,6 +615,7 @@ LocalVariable createLocalVariable({
     isConst: isConst,
     isLate: isLate,
     isWildcard: isWildcard,
+    initializer: initializer,
   )..fileOffset = fileOffset;
 }
 
@@ -1212,13 +1214,11 @@ InternalVariableGet createVariableGet(
 
 VariableInitialization createVariableInitialization({
   required Variable variable,
-  required Expression? initializer,
   required bool hasDeclaredInitializer,
   required int fileOffset,
 }) {
   return new VariableInitialization(
     variable: variable,
-    initializer: initializer,
     hasDeclaredInitializer: hasDeclaredInitializer,
   )..fileOffset = fileOffset;
 }

pkg/kernel/lib/clone.dart

@@ -755,6 +755,7 @@ class CloneVisitorNotMembers
       new LocalVariable(
           cosmeticName: node.cosmeticName,
           type: visitOptionalType(node.type),
+          initializer: cloneOptional(node.initializer),
         )
         ..flags = node.flags
         ..annotations = _cloneAnnotations(node)
@@ -769,6 +770,7 @@ class CloneVisitorNotMembers
       SyntheticVariable(
           cosmeticName: node.cosmeticName,
           type: visitType(node.type),
+          initializer: cloneOptional(node.initializer),
         )
         ..flags = node.flags
         ..annotations = _cloneAnnotations(node)
@@ -816,14 +818,8 @@ class CloneVisitorNotMembers
 
   @override
   TreeNode visitVariableInitialization(VariableInitialization node) {
-    return new VariableInitialization(
-        variable: clone(node.variable),
-        initializer: cloneOptional(node.initializer),
-      )
-      ..flags = node.flags
-      ..annotations = cloneAnnotations && !node.annotations.isEmpty
-          ? node.annotations.map(clone).toList()
-          : const <Expression>[];
+    return new VariableInitialization(variable: clone(node.variable))
+      ..flags = node.flags;
   }
 
   @override

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

@@ -1464,9 +1464,6 @@ abstract class VariableStatement extends Statement {
   /// The declared variable.
   abstract final Variable variable;
 
-  /// The declared initializer, if any.
-  abstract Expression? initializer;
-
   factory VariableStatement(Variable variable) = LegacyVariableStatement;
 }
 
@@ -1480,14 +1477,6 @@ class LegacyVariableStatement extends Statement implements VariableStatement {
     variable.parent = this;
   }
 
-  @override
-  Expression? get initializer => variable.initializer;
-
-  @override
-  void set initializer(Expression? value) {
-    variable.initializer = value;
-  }
-
   @override
   R accept<R>(StatementVisitor<R> v) => v.visitLegacyVariableStatement(this);
 
@@ -1593,9 +1582,6 @@ class VariableInitialization extends Statement
   @override
   Variable variable;
 
-  @override
-  Expression? initializer;
-
   /// Contexts of the variables captured by the late variable initializer.
   ///
   /// If [variable] isn't `late`, [capturedContexts] should be `null`.
@@ -1604,7 +1590,6 @@ class VariableInitialization extends Statement
 
   VariableInitialization({
     required this.variable,
-    required this.initializer,
     bool hasDeclaredInitializer = false,
   }) {
     variable.variableInitialization = this;
@@ -1642,29 +1627,17 @@ class VariableInitialization extends Statement
   @override
   void transformChildren(Transformer v) {
     variable = v.transform(variable)..parent = this;
-    v.transformList(annotations, this);
-    if (initializer != null) {
-      initializer = v.transform(initializer!);
-      initializer?.parent = this;
-    }
   }
 
   @override
   void transformOrRemoveChildren(RemovingTransformer v) {
     variable = v.transformOrRemove(variable, cannotRemoveSentinel)!
       ..parent = this;
-    v.transformExpressionList(annotations, this);
-    if (initializer != null) {
-      initializer = v.transformOrRemoveExpression(initializer!);
-      initializer?.parent = this;
-    }
   }
 
   @override
   void visitChildren(Visitor v) {
     variable.accept(v);
-    visitList(annotations, v);
-    initializer?.accept(v);
   }
 
   @override
@@ -1675,23 +1648,10 @@ class VariableInitialization extends Statement
   @override
   void toTextInternal(AstPrinter printer) {
     printer.write(printer.getVariableName(variable));
-    if (initializer case var initializer?) {
+    if (variable.initializer case var initializer?) {
       printer.write(' := ');
       printer.writeExpression(initializer);
     }
     printer.write(';');
   }
-
-  List<Expression> annotations = const <Expression>[];
-
-  void addAnnotation(Expression node) {
-    if (annotations.isEmpty) {
-      annotations = <Expression>[];
-    }
-    annotations.add(node..parent = this);
-  }
-
-  void clearAnnotations() {
-    annotations = const <Expression>[];
-  }
 }

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

@@ -27,7 +27,7 @@ sealed class VariableBase extends TreeNode implements Annotatable {
 /// implementations of the sealed class [Variable]. It's not supposed
 /// to be used as a type annotation, but purely for declaring the class
 /// hierarchy.
-abstract interface class IVariable implements TreeNode {
+abstract interface class IVariable implements TreeNode, Annotatable {
   abstract DartType type;
   abstract String? cosmeticName;
   abstract VariableInitialization? variableInitialization;
@@ -723,6 +723,10 @@ class LocalVariable extends Variable {
 
   VariableContext? _context;
 
+  @override
+  // TODO(johnniwinther): Remove this.
+  Expression? initializer;
+
   LocalVariable({
     this.cosmeticName,
     required DartType? type,
@@ -730,12 +734,14 @@ class LocalVariable extends Variable {
     bool isConst = false,
     bool isLate = false,
     bool isWildcard = false,
+    this.initializer,
   }) : type = type ?? const DynamicType(),
        super.empty() {
     this.isFinal = isFinal;
     this.isConst = isConst;
     this.isLate = isLate;
     this.isWildcard = isWildcard;
+    this.initializer?.parent = this;
   }
 
   @override
@@ -897,7 +903,7 @@ class LocalVariable extends Variable {
   bool get isAssignable {
     if (isConst) return false;
     if (isFinal) {
-      if (isLate) return variableInitialization?.initializer == null;
+      if (isLate) return initializer == null;
       return false;
     }
     return true;
@@ -911,13 +917,28 @@ class LocalVariable extends Variable {
       v.visitLocalVariable(this, arg);
 
   @override
-  void transformChildren(Transformer v) {}
+  void transformChildren(Transformer v) {
+    v.transformList(annotations, this);
+    if (initializer != null) {
+      initializer = v.transform(initializer!);
+      initializer?.parent = this;
+    }
+  }
 
   @override
-  void transformOrRemoveChildren(RemovingTransformer v) {}
+  void transformOrRemoveChildren(RemovingTransformer v) {
+    v.transformExpressionList(annotations, this);
+    if (initializer != null) {
+      initializer = v.transformOrRemoveExpression(initializer!);
+      initializer?.parent = this;
+    }
+  }
 
   @override
-  void visitChildren(Visitor v) {}
+  void visitChildren(Visitor v) {
+    visitList(annotations, v);
+    initializer?.accept(v);
+  }
 
   @override
   String toString() {
@@ -929,20 +950,6 @@ class LocalVariable extends Variable {
     printer.writeExpressionVariable(this);
   }
 
-  @override
-  Expression? get initializer => variableInitialization?.initializer;
-
-  @override
-  void set initializer(Expression? value) {
-    if (value != null && variableInitialization == null) {
-      throw new StateError(
-        "Attempt to assign initializer to variable "
-        "without an initialization node.",
-      );
-    }
-    variableInitialization!.initializer = value;
-  }
-
   @override
   String? get name => cosmeticName;
 
@@ -1241,13 +1248,19 @@ class CatchVariable extends Variable {
       v.visitCatchVariable(this, arg);
 
   @override
-  void transformChildren(Transformer v) {}
+  void transformChildren(Transformer v) {
+    v.transformList(annotations, this);
+  }
 
   @override
-  void transformOrRemoveChildren(RemovingTransformer v) {}
+  void transformOrRemoveChildren(RemovingTransformer v) {
+    v.transformExpressionList(annotations, this);
+  }
 
   @override
-  void visitChildren(Visitor v) {}
+  void visitChildren(Visitor v) {
+    visitList(annotations, v);
+  }
 
   @override
   String toString() {
@@ -1623,13 +1636,19 @@ class PositionalParameter extends FunctionParameter {
       v.visitPositionalParameter(this, arg);
 
   @override
-  void transformChildren(Transformer v) {}
+  void transformChildren(Transformer v) {
+    v.transformList(annotations, this);
+  }
 
   @override
-  void transformOrRemoveChildren(RemovingTransformer v) {}
+  void transformOrRemoveChildren(RemovingTransformer v) {
+    v.transformExpressionList(annotations, this);
+  }
 
   @override
-  void visitChildren(Visitor v) {}
+  void visitChildren(Visitor v) {
+    visitList(annotations, v);
+  }
 
   @override
   String toString() {
@@ -1784,13 +1803,19 @@ class NamedParameter extends FunctionParameter {
       v.visitNamedParameter(this, arg);
 
   @override
-  void transformChildren(Transformer v) {}
+  void transformChildren(Transformer v) {
+    v.transformList(annotations, this);
+  }
 
   @override
-  void transformOrRemoveChildren(RemovingTransformer v) {}
+  void transformOrRemoveChildren(RemovingTransformer v) {
+    v.transformExpressionList(annotations, this);
+  }
 
   @override
-  void visitChildren(Visitor v) {}
+  void visitChildren(Visitor v) {
+    visitList(annotations, v);
+  }
 
   @override
   String toString() {
@@ -2053,13 +2078,19 @@ class ThisVariable extends Variable {
       v.visitThisVariable(this, arg);
 
   @override
-  void transformChildren(Transformer v) {}
+  void transformChildren(Transformer v) {
+    v.transformList(annotations, this);
+  }
 
   @override
-  void transformOrRemoveChildren(RemovingTransformer v) {}
+  void transformOrRemoveChildren(RemovingTransformer v) {
+    v.transformExpressionList(annotations, this);
+  }
 
   @override
-  void visitChildren(Visitor v) {}
+  void visitChildren(Visitor v) {
+    visitList(annotations, v);
+  }
 
   @override
   String toString() {
@@ -2177,7 +2208,14 @@ class SyntheticVariable extends Variable {
 
   VariableContext? _context;
 
-  SyntheticVariable({this.cosmeticName, required this.type}) : super.empty();
+  @override
+  // TODO(johnniwinther): Remove this.
+  Expression? initializer;
+
+  SyntheticVariable({this.cosmeticName, required this.type, this.initializer})
+    : super.empty() {
+    this.initializer?.parent = this;
+  }
 
   @override
   VariableContext? get context {
@@ -2343,13 +2381,28 @@ class SyntheticVariable extends Variable {
       v.visitSyntheticVariable(this, arg);
 
   @override
-  void transformChildren(Transformer v) {}
+  void transformChildren(Transformer v) {
+    v.transformList(annotations, this);
+    if (initializer != null) {
+      initializer = v.transform(initializer!);
+      initializer?.parent = this;
+    }
+  }
 
   @override
-  void transformOrRemoveChildren(RemovingTransformer v) {}
+  void transformOrRemoveChildren(RemovingTransformer v) {
+    v.transformExpressionList(annotations, this);
+    if (initializer != null) {
+      initializer = v.transformOrRemoveExpression(initializer!);
+      initializer?.parent = this;
+    }
+  }
 
   @override
-  void visitChildren(Visitor v) {}
+  void visitChildren(Visitor v) {
+    visitList(annotations, v);
+    initializer?.accept(v);
+  }
 
   @override
   String toString() {
@@ -2359,20 +2412,6 @@ class SyntheticVariable extends Variable {
   @override
   bool get isAssignable => !isConst && !isFinal;
 
-  @override
-  Expression? get initializer => variableInitialization?.initializer;
-
-  @override
-  void set initializer(Expression? value) {
-    if (value != null && variableInitialization == null) {
-      throw new StateError(
-        "Attempt to assign initializer to variable "
-        "without an initialization node.",
-      );
-    }
-    variableInitialization!.initializer = value;
-  }
-
   @override
   String? get name => cosmeticName;
 

pkg/kernel/lib/src/equivalence.dart

@@ -5965,18 +5965,12 @@ class EquivalenceStrategy {
     if (!checkVariableInitialization_variable(visitor, node, other)) {
       result = visitor.resultOnInequivalence;
     }
-    if (!checkVariableInitialization_initializer(visitor, node, other)) {
-      result = visitor.resultOnInequivalence;
-    }
     if (!checkVariableInitialization_capturedContexts(visitor, node, other)) {
       result = visitor.resultOnInequivalence;
     }
     if (!checkVariableInitialization_flags(visitor, node, other)) {
       result = visitor.resultOnInequivalence;
     }
-    if (!checkVariableInitialization_annotations(visitor, node, other)) {
-      result = visitor.resultOnInequivalence;
-    }
     if (!checkVariableInitialization_fileOffset(visitor, node, other)) {
       result = visitor.resultOnInequivalence;
     }
@@ -6127,6 +6121,9 @@ class EquivalenceStrategy {
     if (!checkLocalVariable_context(visitor, node, other)) {
       result = visitor.resultOnInequivalence;
     }
+    if (!checkLocalVariable_initializer(visitor, node, other)) {
+      result = visitor.resultOnInequivalence;
+    }
     if (!checkLocalVariable_binaryOffsetNoTag(visitor, node, other)) {
       result = visitor.resultOnInequivalence;
     }
@@ -6323,6 +6320,9 @@ class EquivalenceStrategy {
     if (!checkSyntheticVariable_context(visitor, node, other)) {
       result = visitor.resultOnInequivalence;
     }
+    if (!checkSyntheticVariable_initializer(visitor, node, other)) {
+      result = visitor.resultOnInequivalence;
+    }
     if (!checkSyntheticVariable_binaryOffsetNoTag(visitor, node, other)) {
       result = visitor.resultOnInequivalence;
     }
@@ -13326,18 +13326,6 @@ class EquivalenceStrategy {
     return visitor.checkNodes(node.variable, other.variable, 'variable');
   }
 
-  bool checkVariableInitialization_initializer(
-    EquivalenceVisitor visitor,
-    VariableInitialization node,
-    VariableInitialization other,
-  ) {
-    return visitor.checkNodes(
-      node.initializer,
-      other.initializer,
-      'initializer',
-    );
-  }
-
   bool checkVariableInitialization_capturedContexts(
     EquivalenceVisitor visitor,
     VariableInitialization node,
@@ -13361,19 +13349,6 @@ class EquivalenceStrategy {
     return visitor.checkValues(node.flags, other.flags, 'flags');
   }
 
-  bool checkVariableInitialization_annotations(
-    EquivalenceVisitor visitor,
-    VariableInitialization node,
-    VariableInitialization other,
-  ) {
-    return visitor.checkLists(
-      node.annotations,
-      other.annotations,
-      visitor.checkNodes,
-      'annotations',
-    );
-  }
-
   bool checkVariableInitialization_fileOffset(
     EquivalenceVisitor visitor,
     VariableInitialization node,
@@ -13644,6 +13619,18 @@ class EquivalenceStrategy {
     return checkVariableContext(visitor, node.context, other.context);
   }
 
+  bool checkLocalVariable_initializer(
+    EquivalenceVisitor visitor,
+    LocalVariable node,
+    LocalVariable other,
+  ) {
+    return visitor.checkNodes(
+      node.initializer,
+      other.initializer,
+      'initializer',
+    );
+  }
+
   bool checkLocalVariable_binaryOffsetNoTag(
     EquivalenceVisitor visitor,
     LocalVariable node,
@@ -14114,6 +14101,18 @@ class EquivalenceStrategy {
     return checkVariableContext(visitor, node.context, other.context);
   }
 
+  bool checkSyntheticVariable_initializer(
+    EquivalenceVisitor visitor,
+    SyntheticVariable node,
+    SyntheticVariable other,
+  ) {
+    return visitor.checkNodes(
+      node.initializer,
+      other.initializer,
+      'initializer',
+    );
+  }
+
   bool checkSyntheticVariable_binaryOffsetNoTag(
     EquivalenceVisitor visitor,
     SyntheticVariable node,

pkg/kernel/lib/text/ast_to_text.dart

@@ -2846,7 +2846,6 @@ class Printer extends VisitorDefault<void> with VisitorVoidMixin {
     if (node is VariableInitialization) {
       if (showOffsets) writeWord("[${node.fileOffset}]");
       if (showMetadata) writeMetadata(node);
-      writeAnnotationList(node.annotations, separateLines: false);
       writeModifier(node.isErroneouslyInitialized, 'erroneously-initialized');
       bool hasImplicitInitializer =
           variable.initializer is NullLiteral ||

pkg/kernel/lib/type_checker.dart

@@ -1276,9 +1276,9 @@ class TypeCheckingVisitor
   }
 
   void _handleVariableStatement(VariableStatement node) {
-    if (node.initializer != null) {
-      node.initializer = checkExpressionAndAssignability(
-        node.initializer!,
+    if (node.variable.initializer != null) {
+      node.variable.initializer = checkExpressionAndAssignability(
+        node.variable.initializer!,
         node.variable.type,
       );
     }

pkg/vm/lib/modular/transformations/for_in_lowering.dart

@@ -301,11 +301,9 @@ class ForInLowering {
       final variable = SyntheticVariable(
         cosmeticName: ForInVariables.syncForIterator,
         type: type,
-      );
-      final initialization = VariableInitialization(
-        variable: variable,
         initializer: initializer,
       );
+      final initialization = VariableInitialization(variable: variable);
       return (variable, initialization);
     } else {
       final variableAndInitialization = Variable(
@@ -325,14 +323,12 @@ class ForInLowering {
     required Variable variable,
     required Expression initializer,
   }) {
+    initializer.parent = variable;
+    variable..initializer = initializer;
     if (isClosureContextLoweringEnabled) {
-      return VariableInitialization(
-        variable: variable,
-        initializer: initializer,
-      )..fileOffset = variable.fileOffset;
+      return VariableInitialization(variable: variable)
+        ..fileOffset = variable.fileOffset;
     } else {
-      initializer.parent = variable;
-      variable..initializer = initializer;
       return VariableStatement(variable)..fileOffset = variable.fileOffset;
     }
   }