Stop running pub get at gclient sync time and fix build bugs

mojo/public/dart/third_party/analyzer/lib/src/generated/incremental_scanner.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 engine.incremental_scanner;
+
+import "dart:math" as math;
+
+import 'package:analyzer/src/generated/engine.dart';
+
+import 'error.dart';
+import 'scanner.dart';
+import 'source.dart';
+import 'utilities_collection.dart' show TokenMap;
+
+/**
+ * An `IncrementalScanner` is a scanner that scans a subset of a string and
+ * inserts the resulting tokens into the middle of an existing token stream.
+ */
+class IncrementalScanner {
+  /**
+   * The source being scanned.
+   */
+  final Source source;
+
+  /**
+   * The reader used to access the characters in the source.
+   */
+  final CharacterReader reader;
+
+  /**
+   * The error listener that will be informed of any errors that are found
+   * during the scan.
+   *
+   * TODO(brianwilkerson) Replace this with a list of errors so that we can
+   * update the errors.
+   */
+  final AnalysisErrorListener errorListener;
+
+  final AnalysisOptions _options;
+
+  /**
+   * A map from tokens that were copied to the copies of the tokens.
+   */
+  TokenMap _tokenMap = new TokenMap();
+
+  /**
+   * The token immediately to the left of the range of tokens that were
+   * modified.
+   */
+  Token leftToken;
+
+  /**
+   * The token immediately to the right of the range of tokens that were
+   * modified.
+   */
+  Token rightToken;
+
+  /**
+   * A flag indicating whether there were any non-comment tokens changed (other
+   * than having their position updated) as a result of the modification.
+   */
+  bool hasNonWhitespaceChange = false;
+
+  /**
+   * Initialize a newly created scanner to scan characters within the given
+   * [source]. The content of the source can be read using the given [reader].
+   * Any errors that are found will be reported to the given [errorListener].
+   * [_options] will determine how scanning is to be performed.
+   */
+  IncrementalScanner(
+      this.source, this.reader, this.errorListener, this._options);
+
+  /**
+   * Return a map from tokens that were copied to the copies of the tokens.
+   *
+   * @return a map from tokens that were copied to the copies of the tokens
+   */
+  TokenMap get tokenMap => _tokenMap;
+
+  /**
+   * Given the [stream] of tokens scanned from the original source, the modified
+   * source (the result of replacing one contiguous range of characters with
+   * another string of characters), and a specification of the modification that
+   * was made, update the token stream to reflect the modified source. Return
+   * the first token in the updated token stream.
+   *
+   * The [stream] is expected to be the first non-EOF token in the token stream.
+   *
+   * The modification is specified by the [index] of the first character in both
+   * the original and modified source that was affected by the modification, the
+   * number of characters removed from the original source (the [removedLength])
+   * and the number of characters added to the modified source (the
+   * [insertedLength]).
+   */
+  Token rescan(Token stream, int index, int removedLength, int insertedLength) {
+    Token leftEof = stream.previous;
+    //
+    // Compute the delta between the character index of characters after the
+    // modified region in the original source and the index of the corresponding
+    // character in the modified source.
+    //
+    int delta = insertedLength - removedLength;
+    //
+    // Skip past the tokens whose end is less than the replacement start. (If
+    // the replacement start is equal to the end of an existing token, then it
+    // means that the existing token might have been modified, so we need to
+    // rescan it.)
+    //
+    while (stream.type != TokenType.EOF && stream.end < index) {
+      _tokenMap.put(stream, stream);
+      stream = stream.next;
+    }
+    Token oldFirst = stream;
+    Token oldLeftToken = stream.previous;
+    leftToken = oldLeftToken;
+    //
+    // Skip past tokens until we find a token whose offset is greater than the
+    // end of the removed region. (If the end of the removed region is equal to
+    // the beginning of an existing token, then it means that the existing token
+    // might have been modified, so we need to rescan it.)
+    //
+    int removedEnd = index + (removedLength == 0 ? 0 : removedLength - 1);
+    while (stream.type != TokenType.EOF && stream.offset <= removedEnd) {
+      stream = stream.next;
+    }
+    //
+    // Figure out which region of characters actually needs to be re-scanned.
+    //
+    Token oldLast;
+    Token oldRightToken;
+    if (stream.type != TokenType.EOF && removedEnd + 1 == stream.offset) {
+      oldLast = stream;
+      stream = stream.next;
+      oldRightToken = stream;
+    } else {
+      oldLast = stream.previous;
+      oldRightToken = stream;
+    }
+    //
+    // Compute the range of characters that are known to need to be rescanned.
+    // If the index is within an existing token, then we need to start at the
+    // beginning of the token.
+    //
+    int scanStart = math.max(oldLeftToken.end, 0);
+    int scanEnd = oldRightToken.offset + delta;
+    //
+    // Rescan the characters that need to be rescanned.
+    //
+    Token replacementStart = _scanRange(scanStart, scanEnd);
+    oldLeftToken.setNext(replacementStart);
+    Token replacementEnd = _findEof(replacementStart).previous;
+    replacementEnd.setNext(stream);
+    //
+    // Apply the delta to the tokens after the last new token.
+    //
+    _updateOffsets(stream, delta);
+    rightToken = stream;
+    //
+    // If the index is immediately after an existing token and the inserted
+    // characters did not change that original token, then adjust the leftToken
+    // to be the next token. For example, in "a; c;" --> "a;b c;", the leftToken
+    // was ";", but this code advances it to "b" since "b" is the first new
+    // token.
+    //
+    Token newFirst = leftToken.next;
+    while (!identical(newFirst, rightToken) &&
+        !identical(oldFirst, oldRightToken) &&
+        newFirst.type != TokenType.EOF &&
+        _equalTokens(oldFirst, newFirst)) {
+      _tokenMap.put(oldFirst, newFirst);
+      oldLeftToken = oldFirst;
+      oldFirst = oldFirst.next;
+      leftToken = newFirst;
+      newFirst = newFirst.next;
+    }
+    Token newLast = rightToken.previous;
+    while (!identical(newLast, leftToken) &&
+        !identical(oldLast, oldLeftToken) &&
+        newLast.type != TokenType.EOF &&
+        _equalTokens(oldLast, newLast)) {
+      _tokenMap.put(oldLast, newLast);
+      oldRightToken = oldLast;
+      oldLast = oldLast.previous;
+      rightToken = newLast;
+      newLast = newLast.previous;
+    }
+    hasNonWhitespaceChange = !identical(leftToken.next, rightToken) ||
+        !identical(oldLeftToken.next, oldRightToken);
+    //
+    // TODO(brianwilkerson) Begin tokens are not getting associated with the
+    // corresponding end tokens (because the end tokens have not been copied
+    // when we're copying the begin tokens). This could have implications for
+    // parsing.
+    // TODO(brianwilkerson) Update the lineInfo.
+    //
+    return leftEof.next;
+  }
+
+  /**
+   * Return `true` if the [oldToken] and the [newToken] are equal to each other.
+   * For the purposes of the incremental scanner, two tokens are equal if they
+   * have the same type and lexeme.
+   */
+  bool _equalTokens(Token oldToken, Token newToken) =>
+      oldToken.type == newToken.type &&
+          oldToken.length == newToken.length &&
+          oldToken.lexeme == newToken.lexeme;
+
+  /**
+   * Given a [token], return the EOF token that follows the token.
+   */
+  Token _findEof(Token token) {
+    while (token.type != TokenType.EOF) {
+      token = token.next;
+    }
+    return token;
+  }
+
+  /**
+   * Scan the token between the [start] (inclusive) and [end] (exclusive)
+   * offsets.
+   */
+  Token _scanRange(int start, int end) {
+    Scanner scanner = new Scanner(
+        source, new CharacterRangeReader(reader, start, end), errorListener);
+    return scanner.tokenize();
+  }
+
+  /**
+   * Update the offsets of every token from the given [token] to the end of the
+   * stream by adding the given [delta].
+   */
+  void _updateOffsets(Token token, int delta) {
+    while (token.type != TokenType.EOF) {
+      _tokenMap.put(token, token);
+      token.offset += delta;
+      Token comment = token.precedingComments;
+      while (comment != null) {
+        comment.offset += delta;
+        comment = comment.next;
+      }
+      token = token.next;
+    }
+    _tokenMap.put(token, token);
+    token.offset += delta;
+  }
+}