Example #1
0
void CommaSeparatedList::precomputeFormattingInfos(const FormatToken *Token) {
  // FIXME: At some point we might want to do this for other lists, too.
  if (!Token->MatchingParen || Token->isNot(tok::l_brace))
    return;

  FormatToken *ItemBegin = Token->Next;
  SmallVector<bool, 8> MustBreakBeforeItem;

  // The lengths of an item if it is put at the end of the line. This includes
  // trailing comments which are otherwise ignored for column alignment.
  SmallVector<unsigned, 8> EndOfLineItemLength;

  for (unsigned i = 0, e = Commas.size() + 1; i != e; ++i) {
    // Skip comments on their own line.
    while (ItemBegin->HasUnescapedNewline && ItemBegin->isTrailingComment())
      ItemBegin = ItemBegin->Next;

    MustBreakBeforeItem.push_back(ItemBegin->MustBreakBefore);
    const FormatToken *ItemEnd = NULL;
    if (i == Commas.size()) {
      ItemEnd = Token->MatchingParen;
      const FormatToken *NonCommentEnd = ItemEnd->getPreviousNonComment();
      ItemLengths.push_back(CodePointsBetween(ItemBegin, NonCommentEnd));
      if (Style.Cpp11BracedListStyle) {
        // In Cpp11 braced list style, the } and possibly other subsequent
        // tokens will need to stay on a line with the last element.
        while (ItemEnd->Next && !ItemEnd->Next->CanBreakBefore)
          ItemEnd = ItemEnd->Next;
      } else {
        // In other braced lists styles, the "}" can be wrapped to the new line.
        ItemEnd = Token->MatchingParen->Previous;
      }
    } else {
      ItemEnd = Commas[i];
      // The comma is counted as part of the item when calculating the length.
      ItemLengths.push_back(CodePointsBetween(ItemBegin, ItemEnd));
      // Consume trailing comments so the are included in EndOfLineItemLength.
      if (ItemEnd->Next && !ItemEnd->Next->HasUnescapedNewline &&
          ItemEnd->Next->isTrailingComment())
        ItemEnd = ItemEnd->Next;
    }
    EndOfLineItemLength.push_back(CodePointsBetween(ItemBegin, ItemEnd));
    // If there is a trailing comma in the list, the next item will start at the
    // closing brace. Don't create an extra item for this.
    if (ItemEnd->getNextNonComment() == Token->MatchingParen)
      break;
    ItemBegin = ItemEnd->Next;
  }

  // We can never place more than ColumnLimit / 3 items in a row (because of the
  // spaces and the comma).
  for (unsigned Columns = 1; Columns <= Style.ColumnLimit / 3; ++Columns) {
    ColumnFormat Format;
    Format.Columns = Columns;
    Format.ColumnSizes.resize(Columns);
    Format.LineCount = 0;
    bool HasRowWithSufficientColumns = false;
    unsigned Column = 0;
    for (unsigned i = 0, e = ItemLengths.size(); i != e; ++i) {
      if (MustBreakBeforeItem[i] || Column == Columns) {
        ++Format.LineCount;
        Column = 0;
      }
      if (Column == Columns - 1)
        HasRowWithSufficientColumns = true;
      unsigned length =
          (Column == Columns - 1) ? EndOfLineItemLength[i] : ItemLengths[i];
      Format.ColumnSizes[Column] =
          std::max(Format.ColumnSizes[Column], length);
      ++Column;
    }
    // If all rows are terminated early (e.g. by trailing comments), we don't
    // need to look further.
    if (!HasRowWithSufficientColumns)
      break;
    Format.TotalWidth = Columns - 1; // Width of the N-1 spaces.
    for (unsigned i = 0; i < Columns; ++i) {
      Format.TotalWidth += Format.ColumnSizes[i];
    }

    // Ignore layouts that are bound to violate the column limit.
    if (Format.TotalWidth > Style.ColumnLimit)
      continue;

    Formats.push_back(Format);
  }
}
Example #2
0
void CommaSeparatedList::precomputeFormattingInfos(const FormatToken *Token) {
  // FIXME: At some point we might want to do this for other lists, too.
  if (!Token->MatchingParen || Token->isNot(tok::l_brace))
    return;

  // In C++11 braced list style, we should not format in columns unless they
  // have many items (20 or more) or we allow bin-packing of function call
  // arguments.
  if (Style.Cpp11BracedListStyle && !Style.BinPackArguments &&
      Commas.size() < 19)
    return;

  // Column format doesn't really make sense if we don't align after brackets.
  if (!Style.AlignAfterOpenBracket)
    return;

  FormatToken *ItemBegin = Token->Next;
  while (ItemBegin->isTrailingComment())
    ItemBegin = ItemBegin->Next;
  SmallVector<bool, 8> MustBreakBeforeItem;

  // The lengths of an item if it is put at the end of the line. This includes
  // trailing comments which are otherwise ignored for column alignment.
  SmallVector<unsigned, 8> EndOfLineItemLength;

  bool HasSeparatingComment = false;
  for (unsigned i = 0, e = Commas.size() + 1; i != e; ++i) {
    // Skip comments on their own line.
    while (ItemBegin->HasUnescapedNewline && ItemBegin->isTrailingComment()) {
      ItemBegin = ItemBegin->Next;
      HasSeparatingComment = i > 0;
    }

    MustBreakBeforeItem.push_back(ItemBegin->MustBreakBefore);
    if (ItemBegin->is(tok::l_brace))
      HasNestedBracedList = true;
    const FormatToken *ItemEnd = nullptr;
    if (i == Commas.size()) {
      ItemEnd = Token->MatchingParen;
      const FormatToken *NonCommentEnd = ItemEnd->getPreviousNonComment();
      ItemLengths.push_back(CodePointsBetween(ItemBegin, NonCommentEnd));
      if (Style.Cpp11BracedListStyle) {
        // In Cpp11 braced list style, the } and possibly other subsequent
        // tokens will need to stay on a line with the last element.
        while (ItemEnd->Next && !ItemEnd->Next->CanBreakBefore)
          ItemEnd = ItemEnd->Next;
      } else {
        // In other braced lists styles, the "}" can be wrapped to the new line.
        ItemEnd = Token->MatchingParen->Previous;
      }
    } else {
      ItemEnd = Commas[i];
      // The comma is counted as part of the item when calculating the length.
      ItemLengths.push_back(CodePointsBetween(ItemBegin, ItemEnd));

      // Consume trailing comments so the are included in EndOfLineItemLength.
      if (ItemEnd->Next && !ItemEnd->Next->HasUnescapedNewline &&
          ItemEnd->Next->isTrailingComment())
        ItemEnd = ItemEnd->Next;
    }
    EndOfLineItemLength.push_back(CodePointsBetween(ItemBegin, ItemEnd));
    // If there is a trailing comma in the list, the next item will start at the
    // closing brace. Don't create an extra item for this.
    if (ItemEnd->getNextNonComment() == Token->MatchingParen)
      break;
    ItemBegin = ItemEnd->Next;
  }

  // Don't use column layout for nested lists, lists with few elements and in
  // presence of separating comments.
  if (Token->NestingLevel != 0 || Commas.size() < 5 || HasSeparatingComment)
    return;

  // We can never place more than ColumnLimit / 3 items in a row (because of the
  // spaces and the comma).
  unsigned MaxItems = Style.ColumnLimit / 3;
  std::vector<unsigned> MinSizeInColumn;
  MinSizeInColumn.reserve(MaxItems);
  for (unsigned Columns = 1; Columns <= MaxItems; ++Columns) {
    ColumnFormat Format;
    Format.Columns = Columns;
    Format.ColumnSizes.resize(Columns);
    MinSizeInColumn.assign(Columns, UINT_MAX);
    Format.LineCount = 1;
    bool HasRowWithSufficientColumns = false;
    unsigned Column = 0;
    for (unsigned i = 0, e = ItemLengths.size(); i != e; ++i) {
      assert(i < MustBreakBeforeItem.size());
      if (MustBreakBeforeItem[i] || Column == Columns) {
        ++Format.LineCount;
        Column = 0;
      }
      if (Column == Columns - 1)
        HasRowWithSufficientColumns = true;
      unsigned Length =
          (Column == Columns - 1) ? EndOfLineItemLength[i] : ItemLengths[i];
      Format.ColumnSizes[Column] = std::max(Format.ColumnSizes[Column], Length);
      MinSizeInColumn[Column] = std::min(MinSizeInColumn[Column], Length);
      ++Column;
    }
    // If all rows are terminated early (e.g. by trailing comments), we don't
    // need to look further.
    if (!HasRowWithSufficientColumns)
      break;
    Format.TotalWidth = Columns - 1; // Width of the N-1 spaces.

    for (unsigned i = 0; i < Columns; ++i)
      Format.TotalWidth += Format.ColumnSizes[i];

    // Don't use this Format, if the difference between the longest and shortest
    // element in a column exceeds a threshold to avoid excessive spaces.
    if ([&] {
          for (unsigned i = 0; i < Columns - 1; ++i)
            if (Format.ColumnSizes[i] - MinSizeInColumn[i] > 10)
              return true;
          return false;
        }())
      continue;

    // Ignore layouts that are bound to violate the column limit.
    if (Format.TotalWidth > Style.ColumnLimit)
      continue;

    Formats.push_back(Format);
  }
}