| //===--- BreakableToken.cpp - Format C++ code -----------------------------===// |
| // |
| // The LLVM Compiler Infrastructure |
| // |
| // This file is distributed under the University of Illinois Open Source |
| // License. See LICENSE.TXT for details. |
| // |
| //===----------------------------------------------------------------------===// |
| /// |
| /// \file |
| /// \brief Contains implementation of BreakableToken class and classes derived |
| /// from it. |
| /// |
| //===----------------------------------------------------------------------===// |
| |
| #define DEBUG_TYPE "format-token-breaker" |
| |
| #include "BreakableToken.h" |
| #include "clang/Format/Format.h" |
| #include "llvm/ADT/STLExtras.h" |
| #include "llvm/Support/Debug.h" |
| #include <algorithm> |
| |
| namespace clang { |
| namespace format { |
| namespace { |
| |
| BreakableToken::Split getCommentSplit(StringRef Text, |
| unsigned ContentStartColumn, |
| unsigned ColumnLimit, |
| encoding::Encoding Encoding) { |
| if (ColumnLimit <= ContentStartColumn + 1) |
| return BreakableToken::Split(StringRef::npos, 0); |
| |
| unsigned MaxSplit = ColumnLimit - ContentStartColumn + 1; |
| unsigned MaxSplitBytes = 0; |
| |
| for (unsigned NumChars = 0; |
| NumChars < MaxSplit && MaxSplitBytes < Text.size(); ++NumChars) |
| MaxSplitBytes += |
| encoding::getCodePointNumBytes(Text[MaxSplitBytes], Encoding); |
| |
| StringRef::size_type SpaceOffset = Text.rfind(' ', MaxSplitBytes); |
| if (SpaceOffset == StringRef::npos || |
| // Don't break at leading whitespace. |
| Text.find_last_not_of(' ', SpaceOffset) == StringRef::npos) { |
| // Make sure that we don't break at leading whitespace that |
| // reaches past MaxSplit. |
| StringRef::size_type FirstNonWhitespace = Text.find_first_not_of(" "); |
| if (FirstNonWhitespace == StringRef::npos) |
| // If the comment is only whitespace, we cannot split. |
| return BreakableToken::Split(StringRef::npos, 0); |
| SpaceOffset = |
| Text.find(' ', std::max<unsigned>(MaxSplitBytes, FirstNonWhitespace)); |
| } |
| if (SpaceOffset != StringRef::npos && SpaceOffset != 0) { |
| StringRef BeforeCut = Text.substr(0, SpaceOffset).rtrim(); |
| StringRef AfterCut = Text.substr(SpaceOffset).ltrim(); |
| return BreakableToken::Split(BeforeCut.size(), |
| AfterCut.begin() - BeforeCut.end()); |
| } |
| return BreakableToken::Split(StringRef::npos, 0); |
| } |
| |
| BreakableToken::Split getStringSplit(StringRef Text, |
| unsigned ContentStartColumn, |
| unsigned ColumnLimit, |
| encoding::Encoding Encoding) { |
| // FIXME: Reduce unit test case. |
| if (Text.empty()) |
| return BreakableToken::Split(StringRef::npos, 0); |
| if (ColumnLimit <= ContentStartColumn) |
| return BreakableToken::Split(StringRef::npos, 0); |
| unsigned MaxSplit = |
| std::min<unsigned>(ColumnLimit - ContentStartColumn, |
| encoding::getCodePointCount(Text, Encoding) - 1); |
| StringRef::size_type SpaceOffset = 0; |
| StringRef::size_type SlashOffset = 0; |
| StringRef::size_type SplitPoint = 0; |
| for (unsigned Chars = 0;;) { |
| unsigned Advance; |
| if (Text[0] == '\\') { |
| Advance = encoding::getEscapeSequenceLength(Text); |
| Chars += Advance; |
| } else { |
| Advance = encoding::getCodePointNumBytes(Text[0], Encoding); |
| Chars += 1; |
| } |
| |
| if (Chars > MaxSplit) |
| break; |
| |
| if (Text[0] == ' ') |
| SpaceOffset = SplitPoint; |
| if (Text[0] == '/') |
| SlashOffset = SplitPoint; |
| |
| SplitPoint += Advance; |
| Text = Text.substr(Advance); |
| } |
| |
| if (SpaceOffset != 0) |
| return BreakableToken::Split(SpaceOffset + 1, 0); |
| if (SlashOffset != 0) |
| return BreakableToken::Split(SlashOffset + 1, 0); |
| if (SplitPoint != 0) |
| return BreakableToken::Split(SplitPoint, 0); |
| return BreakableToken::Split(StringRef::npos, 0); |
| } |
| |
| } // namespace |
| |
| unsigned BreakableSingleLineToken::getLineCount() const { return 1; } |
| |
| unsigned BreakableSingleLineToken::getLineLengthAfterSplit( |
| unsigned LineIndex, unsigned Offset, StringRef::size_type Length) const { |
| return StartColumn + Prefix.size() + Postfix.size() + |
| encoding::getCodePointCount(Line.substr(Offset, Length), Encoding); |
| } |
| |
| void BreakableSingleLineToken::insertBreak(unsigned LineIndex, |
| unsigned TailOffset, Split Split, |
| bool InPPDirective, |
| WhitespaceManager &Whitespaces) { |
| Whitespaces.breakToken(Tok, Prefix.size() + TailOffset + Split.first, |
| Split.second, Postfix, Prefix, InPPDirective, |
| StartColumn); |
| } |
| |
| BreakableSingleLineToken::BreakableSingleLineToken(const FormatToken &Tok, |
| unsigned StartColumn, |
| StringRef Prefix, |
| StringRef Postfix, |
| encoding::Encoding Encoding) |
| : BreakableToken(Tok, Encoding), StartColumn(StartColumn), Prefix(Prefix), |
| Postfix(Postfix) { |
| assert(Tok.TokenText.startswith(Prefix) && Tok.TokenText.endswith(Postfix)); |
| Line = Tok.TokenText.substr( |
| Prefix.size(), Tok.TokenText.size() - Prefix.size() - Postfix.size()); |
| } |
| |
| BreakableStringLiteral::BreakableStringLiteral(const FormatToken &Tok, |
| unsigned StartColumn, |
| encoding::Encoding Encoding) |
| : BreakableSingleLineToken(Tok, StartColumn, "\"", "\"", Encoding) {} |
| |
| BreakableToken::Split |
| BreakableStringLiteral::getSplit(unsigned LineIndex, unsigned TailOffset, |
| unsigned ColumnLimit) const { |
| return getStringSplit(Line.substr(TailOffset), StartColumn + 2, ColumnLimit, |
| Encoding); |
| } |
| |
| static StringRef getLineCommentPrefix(StringRef Comment) { |
| const char *KnownPrefixes[] = { "/// ", "///", "// ", "//" }; |
| for (size_t i = 0, e = llvm::array_lengthof(KnownPrefixes); i != e; ++i) |
| if (Comment.startswith(KnownPrefixes[i])) |
| return KnownPrefixes[i]; |
| return ""; |
| } |
| |
| BreakableLineComment::BreakableLineComment(const FormatToken &Token, |
| unsigned StartColumn, |
| encoding::Encoding Encoding) |
| : BreakableSingleLineToken(Token, StartColumn, |
| getLineCommentPrefix(Token.TokenText), "", |
| Encoding) {} |
| |
| BreakableToken::Split |
| BreakableLineComment::getSplit(unsigned LineIndex, unsigned TailOffset, |
| unsigned ColumnLimit) const { |
| return getCommentSplit(Line.substr(TailOffset), StartColumn + Prefix.size(), |
| ColumnLimit, Encoding); |
| } |
| |
| BreakableBlockComment::BreakableBlockComment( |
| const FormatStyle &Style, const FormatToken &Token, unsigned StartColumn, |
| unsigned OriginalStartColumn, bool FirstInLine, encoding::Encoding Encoding) |
| : BreakableToken(Token, Encoding) { |
| StringRef TokenText(Token.TokenText); |
| assert(TokenText.startswith("/*") && TokenText.endswith("*/")); |
| TokenText.substr(2, TokenText.size() - 4).split(Lines, "\n"); |
| |
| int IndentDelta = StartColumn - OriginalStartColumn; |
| bool NeedsStar = true; |
| LeadingWhitespace.resize(Lines.size()); |
| StartOfLineColumn.resize(Lines.size()); |
| if (Lines.size() == 1 && !FirstInLine) { |
| // Comments for which FirstInLine is false can start on arbitrary column, |
| // and available horizontal space can be too small to align consecutive |
| // lines with the first one. |
| // FIXME: We could, probably, align them to current indentation level, but |
| // now we just wrap them without stars. |
| NeedsStar = false; |
| } |
| StartOfLineColumn[0] = StartColumn + 2; |
| for (size_t i = 1; i < Lines.size(); ++i) { |
| adjustWhitespace(Style, i, IndentDelta); |
| if (Lines[i].empty()) |
| // If the last line is empty, the closing "*/" will have a star. |
| NeedsStar = NeedsStar && i + 1 == Lines.size(); |
| else |
| NeedsStar = NeedsStar && Lines[i][0] == '*'; |
| } |
| Decoration = NeedsStar ? "* " : ""; |
| IndentAtLineBreak = StartOfLineColumn[0] + 1; |
| for (size_t i = 1; i < Lines.size(); ++i) { |
| if (Lines[i].empty()) { |
| if (!NeedsStar && i + 1 != Lines.size()) |
| // For all but the last line (which always ends in */), set the |
| // start column to 0 if they're empty, so we do not insert |
| // trailing whitespace anywhere. |
| StartOfLineColumn[i] = 0; |
| continue; |
| } |
| if (NeedsStar) { |
| // The first line already excludes the star. |
| // For all other lines, adjust the line to exclude the star and |
| // (optionally) the first whitespace. |
| int Offset = Lines[i].startswith("* ") ? 2 : 1; |
| StartOfLineColumn[i] += Offset; |
| Lines[i] = Lines[i].substr(Offset); |
| LeadingWhitespace[i] += Offset; |
| } |
| IndentAtLineBreak = std::min<int>(IndentAtLineBreak, StartOfLineColumn[i]); |
| } |
| IndentAtLineBreak = std::max<unsigned>(IndentAtLineBreak, Decoration.size()); |
| DEBUG({ |
| for (size_t i = 0; i < Lines.size(); ++i) { |
| llvm::dbgs() << i << " |" << Lines[i] << "| " << LeadingWhitespace[i] |
| << "\n"; |
| } |
| }); |
| } |
| |
| void BreakableBlockComment::adjustWhitespace(const FormatStyle &Style, |
| unsigned LineIndex, |
| int IndentDelta) { |
| // Calculate the end of the non-whitespace text in the previous line. |
| size_t EndOfPreviousLine = Lines[LineIndex - 1].find_last_not_of(" \\\t"); |
| if (EndOfPreviousLine == StringRef::npos) |
| EndOfPreviousLine = 0; |
| else |
| ++EndOfPreviousLine; |
| // Calculate the start of the non-whitespace text in the current line. |
| size_t StartOfLine = Lines[LineIndex].find_first_not_of(" \t"); |
| if (StartOfLine == StringRef::npos) |
| StartOfLine = Lines[LineIndex].size(); |
| |
| // Adjust Lines to only contain relevant text. |
| Lines[LineIndex - 1] = Lines[LineIndex - 1].substr(0, EndOfPreviousLine); |
| Lines[LineIndex] = Lines[LineIndex].substr(StartOfLine); |
| // Adjust LeadingWhitespace to account all whitespace between the lines |
| // to the current line. |
| LeadingWhitespace[LineIndex] = |
| Lines[LineIndex].begin() - Lines[LineIndex - 1].end(); |
| |
| // FIXME: We currently count tabs as 1 character. To solve this, we need to |
| // get the correct indentation width of the start of the comment, which |
| // requires correct counting of the tab expansions before the comment, and |
| // a configurable tab width. Since the current implementation only breaks |
| // if leading tabs are intermixed with spaces, that is not a high priority. |
| |
| // Adjust the start column uniformly accross all lines. |
| StartOfLineColumn[LineIndex] = std::max<int>(0, StartOfLine + IndentDelta); |
| } |
| |
| unsigned BreakableBlockComment::getLineCount() const { return Lines.size(); } |
| |
| unsigned BreakableBlockComment::getLineLengthAfterSplit( |
| unsigned LineIndex, unsigned Offset, StringRef::size_type Length) const { |
| return getContentStartColumn(LineIndex, Offset) + |
| encoding::getCodePointCount(Lines[LineIndex].substr(Offset, Length), |
| Encoding) + |
| // The last line gets a "*/" postfix. |
| (LineIndex + 1 == Lines.size() ? 2 : 0); |
| } |
| |
| BreakableToken::Split |
| BreakableBlockComment::getSplit(unsigned LineIndex, unsigned TailOffset, |
| unsigned ColumnLimit) const { |
| return getCommentSplit(Lines[LineIndex].substr(TailOffset), |
| getContentStartColumn(LineIndex, TailOffset), |
| ColumnLimit, Encoding); |
| } |
| |
| void BreakableBlockComment::insertBreak(unsigned LineIndex, unsigned TailOffset, |
| Split Split, bool InPPDirective, |
| WhitespaceManager &Whitespaces) { |
| StringRef Text = Lines[LineIndex].substr(TailOffset); |
| StringRef Prefix = Decoration; |
| if (LineIndex + 1 == Lines.size() && |
| Text.size() == Split.first + Split.second) { |
| // For the last line we need to break before "*/", but not to add "* ". |
| Prefix = ""; |
| } |
| |
| unsigned BreakOffsetInToken = |
| Text.data() - Tok.TokenText.data() + Split.first; |
| unsigned CharsToRemove = Split.second; |
| assert(IndentAtLineBreak >= Decoration.size()); |
| Whitespaces.breakToken(Tok, BreakOffsetInToken, CharsToRemove, "", Prefix, |
| InPPDirective, IndentAtLineBreak - Decoration.size()); |
| } |
| |
| void |
| BreakableBlockComment::replaceWhitespaceBefore(unsigned LineIndex, |
| unsigned InPPDirective, |
| WhitespaceManager &Whitespaces) { |
| if (LineIndex == 0) |
| return; |
| StringRef Prefix = Decoration; |
| if (Lines[LineIndex].empty()) { |
| if (LineIndex + 1 == Lines.size()) { |
| // If the last line is empty, we don't need a prefix, as the */ will line |
| // up with the decoration (if it exists). |
| Prefix = ""; |
| } else if (!Decoration.empty()) { |
| // For other empty lines, if we do have a decoration, adapt it to not |
| // contain a trailing whitespace. |
| Prefix = Prefix.substr(0, 1); |
| } |
| } else { |
| if (StartOfLineColumn[LineIndex] == 1) { |
| // This lines starts immediately after the decorating *. |
| Prefix = Prefix.substr(0, 1); |
| } |
| } |
| |
| unsigned WhitespaceOffsetInToken = |
| Lines[LineIndex].data() - Tok.TokenText.data() - |
| LeadingWhitespace[LineIndex]; |
| assert(StartOfLineColumn[LineIndex] >= Prefix.size()); |
| Whitespaces.breakToken( |
| Tok, WhitespaceOffsetInToken, LeadingWhitespace[LineIndex], "", Prefix, |
| InPPDirective, StartOfLineColumn[LineIndex] - Prefix.size()); |
| } |
| |
| unsigned |
| BreakableBlockComment::getContentStartColumn(unsigned LineIndex, |
| unsigned TailOffset) const { |
| // If we break, we always break at the predefined indent. |
| if (TailOffset != 0) |
| return IndentAtLineBreak; |
| return StartOfLineColumn[LineIndex]; |
| } |
| |
| } // namespace format |
| } // namespace clang |
