Issue 3752. Support for @override annotations (as structured doc comments)

compiler/java/com/google/dart/compiler/parser/CommentPreservingParser.java

-// Copyright (c) 2012, 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.
-
-package com.google.dart.compiler.parser;
-
-import com.google.dart.compiler.DartCompilerListener;
-import com.google.dart.compiler.DartSource;
-import com.google.dart.compiler.Source;
-import com.google.dart.compiler.ast.ASTVisitor;
-import com.google.dart.compiler.ast.DartComment;
-import com.google.dart.compiler.ast.DartDeclaration;
-import com.google.dart.compiler.ast.DartField;
-import com.google.dart.compiler.ast.DartMethodDefinition;
-import com.google.dart.compiler.ast.DartNode;
-import com.google.dart.compiler.ast.DartUnit;
-import com.google.dart.compiler.common.SourceInfo;
-import com.google.dart.compiler.metrics.CompilerMetrics;
-import com.google.dart.compiler.util.DartSourceString;
-
-import java.util.ArrayList;
-import java.util.Collections;
-import java.util.Comparator;
-import java.util.List;
-
-/**
- * A parser for Dart that records comment positions.
- */
-public class CommentPreservingParser extends DartParser {
-
-  private static class CommentParserContext extends DartScannerParserContext {
-
-    private List<int[]> commentLocs;
-    private String source;
-
-    CommentParserContext(Source source, String code,
-        DartCompilerListener listener) {
-      super(source, code, listener);
-      this.source = code;
-    }
-
-    CommentParserContext(Source source, String code,
-        DartCompilerListener listener, CompilerMetrics metrics) {
-      super(source, code, listener, metrics);
-      this.source = code;
-    }
-
-    List<int[]> getCommentLocs() {
-      return commentLocs;
-    }
-
-    @Override
-    protected DartScanner createScanner(String sourceCode) {
-      commentLocs = new ArrayList<int[]>();
-      return this.new CommentScanner(sourceCode);
-    }
-
-    private class CommentScanner extends DartScanner {
-
-      CommentScanner(String sourceCode) {
-        super(sourceCode);
-      }
-
-      @Override
-      protected void recordCommentLocation(int start, int stop, int line, int col) {
-        int size = commentLocs.size();
-        if (size > 0) {
-          // the parser may re-scan lookahead tokens
-          // fortunately, comments are always scanned as comments
-          int[] loc = commentLocs.get(size - 1);
-          if (start <= loc[0] && stop <= loc[1]) {
-            return;
-          }
-        }
-        commentLocs.add(new int[]{start, stop, line, col});
-      }
-    }
-  }
-
-  /**
-   * Create a parsing context for the comment-recording parser.
-   */
-  public static CommentParserContext createContext(Source source, String code,
-      DartCompilerListener listener) {
-    return new CommentParserContext(source, code, listener);
-  }
-
-  /**
-   * Create a parsing context for the comment-recording parser.
-   */
-  public static CommentParserContext createContext(Source source, String code,
-      DartCompilerListener listener, CompilerMetrics metrics) {
-    return new CommentParserContext(source, code, listener, metrics);
-  }
-
-  private CommentParserContext context;
-  private boolean onlyDartDoc;
-
-  /**
-   * Create a parser on the given <code>code</code> that records comment locations.
-   */
-  public CommentPreservingParser(String code) {
-    this(code, null, false);
-  }
-
-  /**
-   * Create a parser on the given <code>code</code> that records some comment
-   * locations. If <code>onlyDartDoc</code> is <code>true</code> then only
-   * DartDoc comments will be recorded, otherwise all comments will be recorded.
-   * The given <code>listener</code> will be used to inform clients of errors.
-   */
-  public CommentPreservingParser(String code, DartCompilerListener listener,
-      boolean onlyDartDoc) {
-    this(createContext(null, code, listener), onlyDartDoc);
-  }
-
-  /**
-   * Create a parser with the given parsing context <code>context</code>.
-   * If <code>onlyDartDoc</code> is <code>true</code> then only
-   * DartDoc comments will be recorded, otherwise all comments will be recorded.
-   */
-  public CommentPreservingParser(ParserContext context,
-      boolean onlyDartDoc) {
-    super(context, onlyDartDoc);
-    this.context = (CommentParserContext) context;
-    this.onlyDartDoc = onlyDartDoc;
-  }
-
-  @Override
-  public DartUnit parseUnit(DartSource input) {
-    DartUnit unit = super.parseUnit(input);
-
-    String sourceString = context.source;
-    Source source = new DartSourceString(null, sourceString);
-
-    for (int[] loc : context.getCommentLocs()) {
-      DartComment.Style style = getCommentStyle(sourceString, loc[0]);
-      if (!onlyDartDoc || style == DartComment.Style.DART_DOC) {
-        unit.getComments().add(new DartComment(source, loc[0], loc[1] - loc[0], loc[2], loc[3], style));
-      }
-    }
-
-    List<DartComment> comments = unit.getComments();
-
-    if (comments != null) {
-      assignDartComments(unit, comments);
-    }
-
-    return unit;
-  }
-
-  private void assignDartComments(DartUnit unit, List<DartComment> comments) {
-    // Collect the AST nodes in a list.
-    final List<DartNode> astNodes = new ArrayList<DartNode>();
-    unit.accept(new ASTVisitor<DartNode>() {
-      @Override
-      public DartNode visitDeclaration(DartDeclaration<?> node) {
-        astNodes.add(node);
-        return super.visitNode(node);
-      }
-    });
-
-    // Collect all the nodes in one list.
-    List<DartNode> nodes = new ArrayList<DartNode>();
-
-    nodes.addAll(comments);
-    nodes.addAll(astNodes);
-
-    // Sort the nodes by their position in the source file.
-    Collections.sort(nodes, new Comparator<DartNode>() {
-      @Override
-      public int compare(DartNode node1, DartNode node2) {
-        return node1.getSourceInfo().getOffset() - node2.getSourceInfo().getOffset();
-      }
-    });
-
-    // Assign dart docs to their associated DartDeclarations.
-    for (int i = 0; i < nodes.size(); i++) {
-      DartNode node = nodes.get(i);
-
-      if (node instanceof DartComment) {
-        DartComment comment = (DartComment)node;
-
-        if (comment.isDartDoc() && (i + 1 < nodes.size())) {
-          DartNode next = nodes.get(i + 1);
-
-          if (next instanceof DartDeclaration) {
-            DartDeclaration<?> decl = (DartDeclaration<?>)next;
-
-            if (!commentContainedBySibling(comment, decl)) {
-              // Dartc creates both a DartField and a DartMethodDefinition for getters and setters.
-              // They have the same source location; we want to assign the dartdoc to the method
-              // definition and not the field.
-              if (i + 2 < nodes.size()) {
-                decl = adjustDartdocTarget(next, nodes.get(i + 2));
-              }
-              
-              decl.setDartDoc(comment);
-            }
-          }
-        }
-      }
-    }
-  }
-
-  private DartDeclaration<?> adjustDartdocTarget(DartNode currentNode, DartNode nextNode) {
-    if (currentNode instanceof DartField && nextNode instanceof DartMethodDefinition) {
-      if (currentNode.getSourceInfo().equals(nextNode.getSourceInfo())) {
-        return (DartDeclaration<?>)nextNode;
-      }
-    }
-    
-    return (DartDeclaration<?>)currentNode;
-  }
-
-  private boolean commentContainedBySibling(DartComment comment, DartDeclaration<?> node) {
-    for (DartNode child : getChildren(node.getParent())) {
-      if (child != node && !(child instanceof DartComment)) {
-        if (isContainedBy(comment, child)) {
-          return true;
-        }
-      }
-    }
-
-    return false;
-  }
-
-  private List<DartNode> getChildren(DartNode parent) {
-    final List<DartNode> children = new ArrayList<DartNode>();
-
-    parent.visitChildren(new ASTVisitor<DartNode>() {
-      @Override
-      public DartNode visitNode(DartNode node) {
-        children.add(node);
-        return null;
-      }
-    });
-
-    return children;
-  }
-
-  private static boolean isContainedBy(DartNode node, DartNode containedByNode) {
-    SourceInfo nodeSource = node.getSourceInfo();
-    SourceInfo containedBySource = containedByNode.getSourceInfo();
-    int nodeEnd = nodeSource.getOffset() + nodeSource.getLength();
-    int containedByEnd = containedBySource.getOffset() + containedBySource.getLength();
-    return nodeSource.getOffset() >= containedBySource.getOffset()
-        && nodeEnd <= containedByEnd;
-  }
-
-  /**
-   * Return the style of the comment in the given string.
-   *
-   * @param sourceString the source containing the comment
-   * @param commentStart the location of the comment in the source
-   *
-   * @return the style of the comment in the given string
-   */
-  private DartComment.Style getCommentStyle(String sourceString, int commentStart) {
-    if (sourceString.charAt(commentStart + 1) == '/') {
-      return DartComment.Style.END_OF_LINE;
-    } else if (sourceString.charAt(commentStart + 2) == '*') {
-      return DartComment.Style.DART_DOC;
-    }
-    return DartComment.Style.BLOCK;
-  }
-}