Move dart2js from sdk/lib/_internal/compiler to pkg/compiler

sdk/lib/_internal/compiler/implementation/dart_backend/tree_ir_tracer.dart

-// Copyright (c) 2014, 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 tree_ir_tracer;
-
-import 'dart:async' show EventSink;
-import '../tracer.dart';
-import 'tree_ir_nodes.dart';
-
-class Block {
-  Label label;
-  int index;
-  /// Mixed list of [Statement] and [Block].
-  /// A [Block] represents a synthetic goto statement.
-  final List statements = [];
-  final List<Block> predecessors = <Block>[];
-  final List<Block> successors = <Block>[];
-
-  String get name => 'B$index';
-
-  Block([this.label]);
-
-  void addEdgeTo(Block successor) {
-    successors.add(successor);
-    successor.predecessors.add(this);
-  }
-}
-
-class BlockCollector extends StatementVisitor {
-  // Accumulate a list of blocks.  The current block is the last block in
-  // the list.
-  final List<Block> blocks = [new Block()..index = 0];
-
-  // Map tree [Label]s (break or continue targets) and [Statement]s
-  // (if targets) to blocks.
-  final Map<Label, Block> breakTargets = <Label, Block>{};
-  final Map<Label, Block> continueTargets = <Label, Block>{};
-  final Map<Statement, Block> ifTargets = <Statement, Block>{};
-
-  void _addStatement(Statement statement) {
-    blocks.last.statements.add(statement);
-  }
-  void _addGotoStatement(Block target) {
-    blocks.last.statements.add(target);
-  }
-
-  void _addBlock(Block block) {
-    block.index = blocks.length;
-    blocks.add(block);
-  }
-
-  void collect(FunctionDefinition function) {
-    visitStatement(function.body);
-  }
-
-  visitLabeledStatement(LabeledStatement node) {
-    Block target = new Block(node.label);
-    breakTargets[node.label] = target;
-    visitStatement(node.body);
-    _addBlock(target);
-    visitStatement(node.next);
-  }
-
-  visitAssign(Assign node) {
-    _addStatement(node);
-    visitStatement(node.next);
-  }
-
-  visitReturn(Return node) {
-    _addStatement(node);
-  }
-
-  visitBreak(Break node) {
-    _addStatement(node);
-    blocks.last.addEdgeTo(breakTargets[node.target]);
-  }
-
-  visitContinue(Continue node) {
-    _addStatement(node);
-    blocks.last.addEdgeTo(continueTargets[node.target]);
-  }
-
-  visitIf(If node) {
-    _addStatement(node);
-    Block thenTarget = new Block();
-    Block elseTarget = new Block();
-    ifTargets[node.thenStatement] = thenTarget;
-    ifTargets[node.elseStatement] = elseTarget;
-    blocks.last.addEdgeTo(thenTarget);
-    blocks.last.addEdgeTo(elseTarget);
-    _addBlock(thenTarget);
-    visitStatement(node.thenStatement);
-    _addBlock(elseTarget);
-    visitStatement(node.elseStatement);
-  }
-
-  visitWhileTrue(WhileTrue node) {
-    Block continueTarget = new Block();
-    _addGotoStatement(continueTarget);
-
-    continueTargets[node.label] = continueTarget;
-    blocks.last.addEdgeTo(continueTarget);
-    _addBlock(continueTarget);
-    _addStatement(node);
-    visitStatement(node.body);
-  }
-
-  visitWhileCondition(WhileCondition node) {
-    Block whileBlock = new Block();
-    _addGotoStatement(whileBlock);
-
-    _addBlock(whileBlock);
-    _addStatement(node);
-    whileBlock.statements.add(node);
-    blocks.last.addEdgeTo(whileBlock);
-
-    Block bodyBlock = new Block();
-    Block nextBlock = new Block();
-    whileBlock.addEdgeTo(bodyBlock);
-    whileBlock.addEdgeTo(nextBlock);
-
-    continueTargets[node.label] = bodyBlock;
-    _addBlock(bodyBlock);
-    visitStatement(node.body);
-
-    _addBlock(nextBlock);
-    visitStatement(node.next);
-
-    ifTargets[node.body] = bodyBlock;
-    ifTargets[node.next] = nextBlock;
-  }
-
-  visitExpressionStatement(ExpressionStatement node) {
-    _addStatement(node);
-    visitStatement(node.next);
-  }
-
-  visitFunctionDeclaration(FunctionDeclaration node) {
-    _addStatement(node);
-    visitStatement(node.next);
-  }
-}
-
-class TreeTracer extends TracerUtil with StatementVisitor {
-  final EventSink<String> output;
-
-  TreeTracer(this.output);
-
-  Names names;
-  BlockCollector collector;
-  int statementCounter;
-
-  void traceGraph(String name, FunctionDefinition function) {
-    names = new Names();
-    statementCounter = 0;
-    collector = new BlockCollector();
-    collector.collect(function);
-    tag("cfg", () {
-      printProperty("name", name);
-      int blockCounter = 0;
-      collector.blocks.forEach(printBlock);
-    });
-    names = null;
-  }
-
-  void printBlock(Block block) {
-    tag("block", () {
-      printProperty("name", block.name);
-      printProperty("from_bci", -1);
-      printProperty("to_bci", -1);
-      printProperty("predecessors", block.predecessors.map((b) => b.name));
-      printProperty("successors", block.successors.map((b) => b.name));
-      printEmptyProperty("xhandlers");
-      printEmptyProperty("flags");
-      tag("states", () {
-        tag("locals", () {
-          printProperty("size", 0);
-          printProperty("method", "None");
-        });
-      });
-      tag("HIR", () {
-        if (block.label != null) {
-          printStatement(null,
-              "Label ${block.name}, useCount=${block.label.useCount}");
-        }
-        block.statements.forEach(visitBlockMember);
-      });
-    });
-  }
-
-  void visitBlockMember(member) {
-    if (member is Block) {
-      printStatement(null, "goto block B${member.name}");
-    } else {
-      assert(member is Statement);
-      visitStatement(member);
-    }
-  }
-
-  void printStatement(String name, String contents) {
-    int bci = 0;
-    int uses = 0;
-    if (name == null) {
-      name = 'x${statementCounter++}';
-    }
-    addIndent();
-    add("$bci $uses $name $contents <|@\n");
-  }
-
-  visitLabeledStatement(LabeledStatement node) {
-    // These do not get added to a block's list of statements.
-  }
-
-  visitAssign(Assign node) {
-    String name = names.varName(node.variable);
-    String rhs = expr(node.definition);
-    String extra = node.hasExactlyOneUse ? "[single-use]" : "";
-    printStatement(null, "assign $name = $rhs $extra");
-  }
-
-  visitReturn(Return node) {
-    printStatement(null, "return ${expr(node.value)}");
-  }
-
-  visitBreak(Break node) {
-    printStatement(null, "break ${collector.breakTargets[node.target].name}");
-  }
-
-  visitContinue(Continue node) {
-    printStatement(null,
-        "continue ${collector.continueTargets[node.target].name}");
-  }
-
-  visitIf(If node) {
-    String condition = expr(node.condition);
-    String thenTarget = collector.ifTargets[node.thenStatement].name;
-    String elseTarget = collector.ifTargets[node.elseStatement].name;
-    printStatement(null, "if $condition then $thenTarget else $elseTarget");
-  }
-
-  visitWhileTrue(WhileTrue node) {
-    printStatement(null, "while true do");
-  }
-
-  visitWhileCondition(WhileCondition node) {
-    String bodyTarget = collector.ifTargets[node.body].name;
-    String nextTarget = collector.ifTargets[node.next].name;
-    printStatement(null, "while ${expr(node.condition)}");
-    printStatement(null, "do $bodyTarget");
-    printStatement(null, "then $nextTarget" );
-  }
-
-  visitExpressionStatement(ExpressionStatement node) {
-    printStatement(null, expr(node.expression));
-  }
-
-  visitFunctionDeclaration(FunctionDeclaration node) {
-    printStatement(null, 'function ${node.definition.element.name}');
-  }
-
-  String expr(Expression e) {
-    return e.accept(new SubexpressionVisitor(names));
-  }
-}
-
-class SubexpressionVisitor extends ExpressionVisitor<String> {
-  Names names;
-
-  SubexpressionVisitor(this.names);
-
-  String visitVariable(Variable node) {
-    return names.varName(node);
-  }
-
-  String formatArguments(Invoke node) {
-    List<String> args = new List<String>();
-    int positionalArgumentCount = node.selector.positionalArgumentCount;
-    for (int i = 0; i < positionalArgumentCount; ++i) {
-      args.add(node.arguments[i].accept(this));
-    }
-    for (int i = 0; i < node.selector.namedArgumentCount; ++i) {
-      String name = node.selector.namedArguments[i];
-      String arg = node.arguments[positionalArgumentCount + i].accept(this);
-      args.add("$name: $arg");
-    }
-    return args.join(', ');
-  }
-
-  String visitInvokeStatic(InvokeStatic node) {
-    String head = node.target.name;
-    String args = formatArguments(node);
-    return "$head($args)";
-  }
-
-  String visitInvokeMethod(InvokeMethod node) {
-    String receiver = node.receiver.accept(this);
-    String name = node.selector.name;
-    String args = formatArguments(node);
-    return "$receiver.$name($args)";
-  }
-
-  String visitInvokeSuperMethod(InvokeSuperMethod node) {
-    String name = node.selector.name;
-    String args = formatArguments(node);
-    return "super.$name($args)";
-  }
-
-  String visitInvokeConstructor(InvokeConstructor node) {
-    String callName;
-    if (node.target.name.isEmpty) {
-      callName = '${node.type}';
-    } else {
-      callName = '${node.type}.${node.target.name}';
-    }
-    String args = formatArguments(node);
-    String keyword = node.constant != null ? 'const' : 'new';
-    return "$keyword $callName($args)";
-  }
-
-  String visitConcatenateStrings(ConcatenateStrings node) {
-    String args = node.arguments.map(visitExpression).join(', ');
-    return "concat [$args]";
-  }
-
-  String visitLiteralList(LiteralList node) {
-    String values = node.values.map(visitExpression).join(', ');
-    return "list [$values]";
-  }
-
-  String visitLiteralMap(LiteralMap node) {
-    List<String> entries = new List<String>();
-    node.entries.forEach((LiteralMapEntry entry) {
-      String key = visitExpression(entry.key);
-      String value = visitExpression(entry.value);
-      entries.add("$key: $value");
-    });
-    return "map [${entries.join(', ')}]";
-  }
-
-  String visitConstant(Constant node) {
-    return "${node.value}";
-  }
-
-  String visitThis(This node) {
-    return "this";
-  }
-
-  String visitReifyTypeVar(ReifyTypeVar node) {
-    return "typevar [${node.typeVariable.name}]";
-  }
-
-  bool usesInfixNotation(Expression node) {
-    return node is Conditional || node is LogicalOperator;
-  }
-
-  String visitConditional(Conditional node) {
-    String condition = visitExpression(node.condition);
-    String thenExpr = visitExpression(node.thenExpression);
-    String elseExpr = visitExpression(node.elseExpression);
-    return "$condition ? $thenExpr : $elseExpr";
-  }
-
-  String visitLogicalOperator(LogicalOperator node) {
-    String left = visitExpression(node.left);
-    String right = visitExpression(node.right);
-    if (usesInfixNotation(node.left)) {
-      left = "($left)";
-    }
-    if (usesInfixNotation(node.right)) {
-      right = "($right)";
-    }
-    return "$left ${node.operator} $right";
-  }
-
-  String visitTypeOperator(TypeOperator node) {
-    String receiver = visitExpression(node.receiver);
-    String type = "${node.type}";
-    return "TypeOperator $receiver ${node.operator} $type";
-  }
-
-  String visitNot(Not node) {
-    String operand = visitExpression(node.operand);
-    if (usesInfixNotation(node.operand)) {
-      operand = '($operand)';
-    }
-    return '!$operand';
-  }
-
-  String visitFunctionExpression(FunctionExpression node) {
-    return "function ${node.definition.element.name}";
-  }
-
-}
-
-/**
- * Invents (and remembers) names for Variables that do not have an associated
- * identifier.
- *
- * In case a variable is named v0, v1, etc, it may be assigned a different
- * name to avoid clashing with a previously synthesized variable name.
- */
-class Names {
-  final Map<Variable, String> _names = {};
-  final Set<String> _usedNames = new Set();
-  int _counter = 0;
-
-  String varName(Variable v) {
-    String name = _names[v];
-    if (name == null) {
-      String prefix = v.element == null ? 'v' : '${v.element.name}_';
-      while (name == null || _usedNames.contains(name)) {
-        name = "$prefix${_counter++}";
-      }
-      _names[v] = name;
-      _usedNames.add(name);
-    }
-    return name;
-  }
-}