Add fasta-based summary generation code.

pkg/analyzer/lib/src/summary/fasta/expression_serializer.dart

+// Copyright (c) 2017, 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.
+
+/// Algorithm to serialize expressions into the format used by summaries.
+library summary.src.expression_serializer;
+
+import 'model.dart';
+import 'package:front_end/src/fasta/scanner/token_constants.dart';
+
+/// Visitor over the minimal expression AST to convert them into stack-like
+/// expressions used in the summary format.
+class Serializer extends RecursiveVisitor {
+  UnlinkedExprBuilder expression;
+  final Scope scope;
+  final bool forConst;
+
+  Serializer(this.scope, this.forConst);
+
+  run(Expression root) {
+    expression = new UnlinkedExprBuilder(
+        isValidConst: forConst,
+        operations: [],
+        assignmentOperators: [],
+        ints: [],
+        doubles: [],
+        strings: [],
+        references: []);
+    root.accept(this);
+    expression.references.forEach((r) => (r as LazyEntityRef).expand());
+    return expression;
+  }
+
+  handleRef(Ref n, {push: true}) {
+    var ref = n.prefix == null
+        ? new LazyEntityRef(n.name, scope)
+        : new NestedLazyEntityRef(
+            handleRef(n.prefix, push: false), n.name, scope);
+    if (push) {
+      expression.references.add(ref);
+      expression.operations.add(UnlinkedExprOperation.pushReference);
+    }
+    return ref;
+  }
+
+  handleNull(NullLiteral n) {
+    expression.operations.add(UnlinkedExprOperation.pushNull);
+  }
+
+  handleBool(BoolLiteral n) {
+    expression.operations.add(n.value
+        ? UnlinkedExprOperation.pushTrue
+        : UnlinkedExprOperation.pushFalse);
+  }
+
+  handleInt(IntLiteral n) {
+    var ints = expression.ints;
+    var operations = expression.operations;
+    int value = n.value;
+    assert(value >= 0);
+    if (value >= (1 << 32)) {
+      int numOfComponents = 0;
+      expression.ints.add(numOfComponents);
+      void pushComponents(int value) {
+        if (value >= (1 << 32)) {
+          pushComponents(value >> 32);
+        }
+        numOfComponents++;
+        ints.add(value & 0xFFFFFFFF);
+      }
+      pushComponents(value);
+      ints[ints.length - 1 - numOfComponents] = numOfComponents;
+      operations.add(UnlinkedExprOperation.pushLongInt);
+    } else {
+      operations.add(UnlinkedExprOperation.pushInt);
+      ints.add(value);
+    }
+  }
+
+  handleDouble(DoubleLiteral n) {
+    expression.operations.add(UnlinkedExprOperation.pushDouble);
+    expression.doubles.add(n.value);
+  }
+
+  handleType(TypeRef n) {
+    var t = handleRef(n.name, push: false);
+    var args = n.typeArguments ?? [];
+    t.typeArguments = args.map((a) => handleType(a)).toList();
+    return t;
+  }
+
+  handleList(ListLiteral n) {
+    expression.ints.add(n.values.length);
+    if (n.elementType == null) {
+      expression.operations.add(UnlinkedExprOperation.makeUntypedList);
+    } else {
+      handleType(n.elementType);
+      expression.operations.add(UnlinkedExprOperation.makeTypedList);
+    }
+  }
+
+  handleMap(MapLiteral n) {
+    expression.ints.add(n.values.length);
+    if (n.types.isEmpty) {
+      expression.operations.add(UnlinkedExprOperation.makeUntypedMap);
+    } else {
+      n.types.forEach(handleType);
+      expression.operations.add(UnlinkedExprOperation.makeTypedMap);
+    }
+  }
+
+  handleString(StringLiteral n) {
+    expression.strings.add(n.value);
+    expression.operations.add(UnlinkedExprOperation.pushString);
+  }
+
+  handleSymbol(SymbolLiteral n) {
+    expression.strings.add(n.value);
+    expression.operations.add(UnlinkedExprOperation.makeSymbol);
+  }
+
+  handleAs(As n) {
+    throw new UnimplementedError(); // TODO(paulberry): fix the code below.
+    // handleType(a.type);
+    // expression.operations.add(UnlinkedExprOperation.typeCast);
+  }
+
+  handleIs(Is n) {
+    throw new UnimplementedError(); // TODO(paulberry): fix the code below.
+    // handleType(i.type);
+    // expression.operations.add(UnlinkedExprOperation.typeCheck);
+  }
+
+  handleUnary(Unary n) {
+    expression.operations.add(_unaryOpFor(n.operator));
+  }
+
+  handleBinary(Binary n){
+    expression.operations.add(_binaryOpFor(n.operator));
+  }
+
+  handleLoad(Load n){
+    expression.strings.add(n.name);
+    expression.operations.add(UnlinkedExprOperation.extractProperty);
+  }
+
+  handleIdentical(Identical n){
+    expression.references.add(handleRef(new Ref('identical'), push: false));
+    expression.ints.add(0);
+    expression.ints.add(2);
+    expression.ints.add(0);
+    expression.operations.add(UnlinkedExprOperation.invokeMethodRef);
+  }
+
+  handleConditional(Conditional n) {
+    expression.operations.add(UnlinkedExprOperation.conditional);
+  }
+
+  handleConstCreation(ConstCreation n) {
+    var ctor = n.constructor;
+    var type = handleType(ctor.type);
+    if (ctor.name != null) {
+      throw new UnimplementedError(); // TODO(paulberry): fix the code below.
+      //var classRef = handleRef(ctor.type.name, push: false);
+      //var top = scope.top;
+      //var ref = new LazyEntityRef(ctor.name, top)
+      //  ..reference = (scope.serializeReference(classRef.reference, ctor.name))
+      //  ..typeArguments = type.typeArguments
+      //  ..wasExpanded = true;
+      //expression.references.add(ref);
+    } else {
+      expression.references.add(type);
+    }
+    expression.ints.add(n.namedArgs.length);
+    expression.ints.add(n.positionalArgs.length);
+    expression.strings.addAll(n.namedArgs.map((a) => a.name));
+    expression.operations.add(UnlinkedExprOperation.invokeConstructor);
+  }
+
+  handleInvalid(Invalid n) {
+    expression.isValidConst = false;
+    throw new UnimplementedError(); // TODO(paulberry): fix the code below.
+    // expression.operations.add(UnlinkedExprOperation.pushInvalidor);
+  }
+
+  handleOpaque(Opaque n) {
+    if (n.type != null) {
+      handleType(n.type);
+      expression.operations.add(UnlinkedExprOperation.pushTypedAbstract);
+    } else {
+      expression.operations.add(UnlinkedExprOperation.pushUntypedAbstract);
+    }
+  }
+
+  handleOpaqueOp(OpaqueOp n) {
+    // nothing to do, recursive visitor serialized subexpression.
+  }
+}
+
+/// Translate a parser unary operation into an operation in the summary format.
+UnlinkedExprOperation _unaryOpFor(int operatorKind) {
+  switch (operatorKind) {
+    case BANG_TOKEN: return UnlinkedExprOperation.not;
+    case MINUS_TOKEN: return UnlinkedExprOperation.negate;
+    default:
+      throw "Unhandled operator kind $operatorKind";
+  }
+}
+
+/// Translate a parser binary operation into an operation in the summary format.
+UnlinkedExprOperation _binaryOpFor(int operatorKind) {
+  switch (operatorKind) {
+    case AMPERSAND_TOKEN: return UnlinkedExprOperation.bitAnd;
+    case AMPERSAND_AMPERSAND_TOKEN: return UnlinkedExprOperation.and;
+    case BANG_EQ_TOKEN: return UnlinkedExprOperation.notEqual;
+    case BAR_TOKEN: return UnlinkedExprOperation.bitOr;
+    case BAR_BAR_TOKEN: return UnlinkedExprOperation.or;
+    case CARET_TOKEN: return UnlinkedExprOperation.bitXor;
+    case EQ_EQ_TOKEN: return UnlinkedExprOperation.equal;
+    case GT_TOKEN: return UnlinkedExprOperation.greater;
+    case GT_EQ_TOKEN: return UnlinkedExprOperation.greaterEqual;
+    case GT_GT_TOKEN: return UnlinkedExprOperation.bitShiftRight;
+    case LT_TOKEN: return UnlinkedExprOperation.less;
+    case LT_EQ_TOKEN: return UnlinkedExprOperation.lessEqual;
+    case LT_LT_TOKEN: return UnlinkedExprOperation.bitShiftLeft;
+    case MINUS_TOKEN: return UnlinkedExprOperation.subtract;
+    case PERCENT_TOKEN: return UnlinkedExprOperation.modulo;
+    case PERIOD_TOKEN: return UnlinkedExprOperation.extractProperty;
+    case PLUS_TOKEN: return UnlinkedExprOperation.add;
+    case QUESTION_QUESTION_TOKEN: return UnlinkedExprOperation.ifNull;
+    case SLASH_TOKEN: return UnlinkedExprOperation.divide;
+    case STAR_TOKEN: return UnlinkedExprOperation.multiply;
+    case TILDE_SLASH_TOKEN: return UnlinkedExprOperation.floorDivide;
+    default:
+      throw "Unhandled openratorKind $operatorKind";
+  }
+}