Serialize constant initializers.

pkg/analyzer/lib/src/summary/summarize_const_expr.dart

+// Copyright (c) 2016, 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 serialization.summarize_const_expr;
+
+import 'package:analyzer/src/generated/ast.dart';
+import 'package:analyzer/src/generated/scanner.dart';
+import 'package:analyzer/src/summary/format.dart';
+
+/**
+ * Instances of this class keep track of intermediate state during
+ * serialization of a single constant [Expression].
+ */
+abstract class AbstractConstExprSerializer {
+  /**
+   * See [UnlinkedConstBuilder.operations].
+   */
+  final List<UnlinkedConstOperation> operations = <UnlinkedConstOperation>[];
+
+  /**
+   * See [UnlinkedConstBuilder.ints].
+   */
+  final List<int> ints = <int>[];
+
+  /**
+   * See [UnlinkedConstBuilder.doubles].
+   */
+  final List<double> doubles = <double>[];
+
+  /**
+   * See [UnlinkedConstBuilder.strings].
+   */
+  final List<String> strings = <String>[];
+
+  /**
+   * See [UnlinkedConstBuilder.references].
+   */
+  final List<UnlinkedTypeRefBuilder> references = <UnlinkedTypeRefBuilder>[];
+
+  /**
+   * Serialize the given [expr] expression into this serializer state.
+   */
+  void serialize(Expression expr) {
+    if (expr is IntegerLiteral) {
+      _pushInt(expr.value);
+    } else if (expr is DoubleLiteral) {
+      operations.add(UnlinkedConstOperation.pushDouble);
+      doubles.add(expr.value);
+    } else if (expr is BooleanLiteral) {
+      if (expr.value) {
+        operations.add(UnlinkedConstOperation.pushTrue);
+      } else {
+        operations.add(UnlinkedConstOperation.pushFalse);
+      }
+    } else if (expr is StringLiteral) {
+      _serializeString(expr);
+    } else if (expr is SymbolLiteral) {
+      strings.add(expr.components.map((token) => token.lexeme).join('.'));
+      operations.add(UnlinkedConstOperation.pushString);
+      operations.add(UnlinkedConstOperation.makeSymbol);
+    } else if (expr is NullLiteral) {
+      operations.add(UnlinkedConstOperation.pushNull);
+    } else if (expr is Identifier) {
+      references.add(serializeIdentifier(expr));
+    } else if (expr is InstanceCreationExpression) {
+      _serializeInstanceCreation(expr);
+    } else if (expr is ListLiteral) {
+      _serializeListLiteral(expr);
+    } else if (expr is MapLiteral) {
+      _serializeMapLiteral(expr);
+    } else if (expr is MethodInvocation) {
+      String name = expr.methodName.name;
+      if (name != 'identical') {
+        throw new _ConstExprSerializationError(
+            'Only "identity" function invocation is allowed.');
+      }
+      if (expr.argumentList == null ||
+          expr.argumentList.arguments.length != 2) {
+        throw new _ConstExprSerializationError(
+            'The function "identity" requires exactly 2 arguments.');
+      }
+      expr.argumentList.arguments.forEach(serialize);
+      operations.add(UnlinkedConstOperation.identical);
+    } else if (expr is BinaryExpression) {
+      _serializeBinaryExpression(expr);
+    } else if (expr is ConditionalExpression) {
+      serialize(expr.condition);
+      serialize(expr.thenExpression);
+      serialize(expr.elseExpression);
+      operations.add(UnlinkedConstOperation.conditional);
+    } else if (expr is PrefixExpression) {
+      _serializePrefixExpression(expr);
+    } else if (expr is PropertyAccess && expr.propertyName.name == 'length') {
+      serialize(expr.target);
+      operations.add(UnlinkedConstOperation.length);
+    } else if (expr is ParenthesizedExpression) {
+      serialize(expr.expression);
+    } else {
+      throw new _ConstExprSerializationError('Unknown expression type: $expr');
+    }
+  }
+
+  /**
+   * Return [UnlinkedTypeRefBuilder] that corresponds to the given [identifier].
+   */
+  UnlinkedTypeRefBuilder serializeIdentifier(Identifier identifier);
+
+  /**
+   * Return [UnlinkedTypeRefBuilder] that corresponds to the given [type].
+   */
+  UnlinkedTypeRefBuilder serializeType(TypeName type);
+
+  /**
+   * Return the [UnlinkedConstBuilder] that corresponds to the state of this
+   * serializer.
+   */
+  UnlinkedConstBuilder toBuilder() {
+    return new UnlinkedConstBuilder(
+        operations: operations,
+        ints: ints,
+        doubles: doubles,
+        strings: strings,
+        references: references);
+  }
+
+  void _pushInt(int value) {
+    // TODO(scheglov) add support for arbitrary precision ints
+    assert(value.abs() < (2 << 31));
+    ints.add(value & 0xFFFFFFFF);
+    operations.add(UnlinkedConstOperation.pushInt);
+  }
+
+  void _serializeBinaryExpression(BinaryExpression expr) {
+    serialize(expr.leftOperand);
+    serialize(expr.rightOperand);
+    TokenType operator = expr.operator.type;
+    if (operator == TokenType.EQ_EQ) {
+      operations.add(UnlinkedConstOperation.equal);
+    } else if (operator == TokenType.BANG_EQ) {
+      operations.add(UnlinkedConstOperation.equal);
+      operations.add(UnlinkedConstOperation.not);
+    } else if (operator == TokenType.AMPERSAND_AMPERSAND) {
+      operations.add(UnlinkedConstOperation.and);
+    } else if (operator == TokenType.BAR_BAR) {
+      operations.add(UnlinkedConstOperation.or);
+    } else if (operator == TokenType.CARET) {
+      operations.add(UnlinkedConstOperation.bitXor);
+    } else if (operator == TokenType.AMPERSAND) {
+      operations.add(UnlinkedConstOperation.bitAnd);
+    } else if (operator == TokenType.BAR) {
+      operations.add(UnlinkedConstOperation.bitOr);
+    } else if (operator == TokenType.GT_GT) {
+      operations.add(UnlinkedConstOperation.bitShiftRight);
+    } else if (operator == TokenType.LT_LT) {
+      operations.add(UnlinkedConstOperation.bitShiftLeft);
+    } else if (operator == TokenType.PLUS) {
+      operations.add(UnlinkedConstOperation.add);
+    } else if (operator == TokenType.MINUS) {
+      operations.add(UnlinkedConstOperation.subtract);
+    } else if (operator == TokenType.STAR) {
+      operations.add(UnlinkedConstOperation.multiply);
+    } else if (operator == TokenType.SLASH) {
+      operations.add(UnlinkedConstOperation.divide);
+    } else if (operator == TokenType.TILDE_SLASH) {
+      operations.add(UnlinkedConstOperation.floorDivide);
+    } else if (operator == TokenType.GT) {
+      operations.add(UnlinkedConstOperation.greater);
+    } else if (operator == TokenType.LT) {
+      operations.add(UnlinkedConstOperation.less);
+    } else if (operator == TokenType.GT_EQ) {
+      operations.add(UnlinkedConstOperation.greaterEqual);
+    } else if (operator == TokenType.LT_EQ) {
+      operations.add(UnlinkedConstOperation.lessEqual);
+    } else if (operator == TokenType.PERCENT) {
+      operations.add(UnlinkedConstOperation.modulo);
+    } else {
+      throw new _ConstExprSerializationError('Unknown operator: $operator');
+    }
+  }
+
+  void _serializeInstanceCreation(InstanceCreationExpression expr) {
+    ConstructorName constructor = expr.constructorName;
+    List<Expression> arguments = expr.argumentList.arguments;
+    arguments.forEach(serialize);
+    operations.add(UnlinkedConstOperation.invokeConstructor);
+    references.add(serializeType(constructor.type));
+    if (constructor.name != null) {
+      strings.add(constructor.name.name);
+    } else {
+      strings.add('');
+    }
+    // TODO(scheglov) named arguments?
+    ints.add(arguments.length);
+  }
+
+  void _serializeListLiteral(ListLiteral expr) {
+    List<Expression> elements = expr.elements;
+    elements.forEach(serialize);
+    TypeName typeArgument;
+    if (expr.typeArguments != null &&
+        expr.typeArguments.arguments.length == 1) {
+      typeArgument = expr.typeArguments.arguments[0];
+    }
+    references.add(serializeType(typeArgument));
+    ints.add(elements.length);
+    operations.add(UnlinkedConstOperation.makeList);
+  }
+
+  void _serializeMapLiteral(MapLiteral expr) {
+    for (MapLiteralEntry entry in expr.entries) {
+      serialize(entry.key);
+      serialize(entry.value);
+    }
+    TypeName keyTypeArgument;
+    TypeName valueTypeArgument;
+    if (expr.typeArguments != null &&
+        expr.typeArguments.arguments.length == 2) {
+      keyTypeArgument = expr.typeArguments.arguments[0];
+      valueTypeArgument = expr.typeArguments.arguments[1];
+    }
+    references.add(serializeType(keyTypeArgument));
+    references.add(serializeType(valueTypeArgument));
+    ints.add(expr.entries.length);
+    operations.add(UnlinkedConstOperation.makeMap);
+  }
+
+  void _serializePrefixExpression(PrefixExpression expr) {
+    serialize(expr.operand);
+    TokenType operator = expr.operator.type;
+    if (operator == TokenType.BANG) {
+      operations.add(UnlinkedConstOperation.not);
+    } else if (operator == TokenType.MINUS) {
+      operations.add(UnlinkedConstOperation.negate);
+    } else if (operator == TokenType.TILDE) {
+      operations.add(UnlinkedConstOperation.complement);
+    } else {
+      throw new _ConstExprSerializationError('Unknown operator: $operator');
+    }
+  }
+
+  void _serializeString(StringLiteral expr) {
+    if (expr is AdjacentStrings) {
+      if (expr.strings.every((string) => string is SimpleStringLiteral)) {
+        operations.add(UnlinkedConstOperation.pushString);
+        strings.add(expr.stringValue);
+      } else {
+        expr.strings.forEach(_serializeString);
+        operations.add(UnlinkedConstOperation.concatenate);
+        ints.add(expr.strings.length);
+      }
+    } else if (expr is SimpleStringLiteral) {
+      operations.add(UnlinkedConstOperation.pushString);
+      strings.add(expr.value);
+    } else {
+      StringInterpolation interpolation = expr as StringInterpolation;
+      for (InterpolationElement element in interpolation.elements) {
+        if (element is InterpolationString) {
+          operations.add(UnlinkedConstOperation.pushString);
+          strings.add(element.value);
+        } else {
+          serialize((element as InterpolationExpression).expression);
+        }
+      }
+      operations.add(UnlinkedConstOperation.concatenate);
+      ints.add(interpolation.elements.length);
+    }
+  }
+}
+
+/**
+ * Error that describes a problem during a constant expression serialization.
+ */
+class _ConstExprSerializationError {
+  final String message;
+
+  _ConstExprSerializationError(this.message);
+
+  @override
+  String toString() => message;
+}