| //===--- WhitespaceManager.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 This file implements WhitespaceManager class. |
| /// |
| //===----------------------------------------------------------------------===// |
| |
| #include "WhitespaceManager.h" |
| #include "llvm/ADT/STLExtras.h" |
| |
| namespace clang { |
| namespace format { |
| |
| bool WhitespaceManager::Change::IsBeforeInFile:: |
| operator()(const Change &C1, const Change &C2) const { |
| return SourceMgr.isBeforeInTranslationUnit( |
| C1.OriginalWhitespaceRange.getBegin(), |
| C2.OriginalWhitespaceRange.getBegin()); |
| } |
| |
| WhitespaceManager::Change::Change( |
| bool CreateReplacement, const SourceRange &OriginalWhitespaceRange, |
| unsigned IndentLevel, int Spaces, unsigned StartOfTokenColumn, |
| unsigned NewlinesBefore, StringRef PreviousLinePostfix, |
| StringRef CurrentLinePrefix, tok::TokenKind Kind, bool ContinuesPPDirective) |
| : CreateReplacement(CreateReplacement), |
| OriginalWhitespaceRange(OriginalWhitespaceRange), |
| StartOfTokenColumn(StartOfTokenColumn), NewlinesBefore(NewlinesBefore), |
| PreviousLinePostfix(PreviousLinePostfix), |
| CurrentLinePrefix(CurrentLinePrefix), Kind(Kind), |
| ContinuesPPDirective(ContinuesPPDirective), IndentLevel(IndentLevel), |
| Spaces(Spaces), IsTrailingComment(false), TokenLength(0), |
| PreviousEndOfTokenColumn(0), EscapedNewlineColumn(0), |
| StartOfBlockComment(nullptr), IndentationOffset(0) {} |
| |
| void WhitespaceManager::reset() { |
| Changes.clear(); |
| Replaces.clear(); |
| } |
| |
| void WhitespaceManager::replaceWhitespace(FormatToken &Tok, unsigned Newlines, |
| unsigned IndentLevel, unsigned Spaces, |
| unsigned StartOfTokenColumn, |
| bool InPPDirective) { |
| if (Tok.Finalized) |
| return; |
| Tok.Decision = (Newlines > 0) ? FD_Break : FD_Continue; |
| Changes.push_back(Change(true, Tok.WhitespaceRange, IndentLevel, Spaces, |
| StartOfTokenColumn, Newlines, "", "", |
| Tok.Tok.getKind(), InPPDirective && !Tok.IsFirst)); |
| } |
| |
| void WhitespaceManager::addUntouchableToken(const FormatToken &Tok, |
| bool InPPDirective) { |
| if (Tok.Finalized) |
| return; |
| Changes.push_back(Change(false, Tok.WhitespaceRange, /*IndentLevel=*/0, |
| /*Spaces=*/0, Tok.OriginalColumn, Tok.NewlinesBefore, |
| "", "", Tok.Tok.getKind(), |
| InPPDirective && !Tok.IsFirst)); |
| } |
| |
| void WhitespaceManager::replaceWhitespaceInToken( |
| const FormatToken &Tok, unsigned Offset, unsigned ReplaceChars, |
| StringRef PreviousPostfix, StringRef CurrentPrefix, bool InPPDirective, |
| unsigned Newlines, unsigned IndentLevel, int Spaces) { |
| if (Tok.Finalized) |
| return; |
| SourceLocation Start = Tok.getStartOfNonWhitespace().getLocWithOffset(Offset); |
| Changes.push_back(Change( |
| true, SourceRange(Start, Start.getLocWithOffset(ReplaceChars)), |
| IndentLevel, Spaces, std::max(0, Spaces), Newlines, PreviousPostfix, |
| CurrentPrefix, |
| // If we don't add a newline this change doesn't start a comment. Thus, |
| // when we align line comments, we don't need to treat this change as one. |
| // FIXME: We still need to take this change in account to properly |
| // calculate the new length of the comment and to calculate the changes |
| // for which to do the alignment when aligning comments. |
| Tok.is(TT_LineComment) && Newlines > 0 ? tok::comment : tok::unknown, |
| InPPDirective && !Tok.IsFirst)); |
| } |
| |
| const tooling::Replacements &WhitespaceManager::generateReplacements() { |
| if (Changes.empty()) |
| return Replaces; |
| |
| std::sort(Changes.begin(), Changes.end(), Change::IsBeforeInFile(SourceMgr)); |
| calculateLineBreakInformation(); |
| alignTrailingComments(); |
| alignEscapedNewlines(); |
| generateChanges(); |
| |
| return Replaces; |
| } |
| |
| void WhitespaceManager::calculateLineBreakInformation() { |
| Changes[0].PreviousEndOfTokenColumn = 0; |
| for (unsigned i = 1, e = Changes.size(); i != e; ++i) { |
| unsigned OriginalWhitespaceStart = |
| SourceMgr.getFileOffset(Changes[i].OriginalWhitespaceRange.getBegin()); |
| unsigned PreviousOriginalWhitespaceEnd = SourceMgr.getFileOffset( |
| Changes[i - 1].OriginalWhitespaceRange.getEnd()); |
| Changes[i - 1].TokenLength = OriginalWhitespaceStart - |
| PreviousOriginalWhitespaceEnd + |
| Changes[i].PreviousLinePostfix.size() + |
| Changes[i - 1].CurrentLinePrefix.size(); |
| |
| Changes[i].PreviousEndOfTokenColumn = |
| Changes[i - 1].StartOfTokenColumn + Changes[i - 1].TokenLength; |
| |
| Changes[i - 1].IsTrailingComment = |
| (Changes[i].NewlinesBefore > 0 || Changes[i].Kind == tok::eof) && |
| Changes[i - 1].Kind == tok::comment; |
| } |
| // FIXME: The last token is currently not always an eof token; in those |
| // cases, setting TokenLength of the last token to 0 is wrong. |
| Changes.back().TokenLength = 0; |
| Changes.back().IsTrailingComment = Changes.back().Kind == tok::comment; |
| |
| const WhitespaceManager::Change *LastBlockComment = nullptr; |
| for (auto &Change : Changes) { |
| Change.StartOfBlockComment = nullptr; |
| Change.IndentationOffset = 0; |
| if (Change.Kind == tok::comment) { |
| LastBlockComment = &Change; |
| } else if (Change.Kind == tok::unknown) { |
| if ((Change.StartOfBlockComment = LastBlockComment)) |
| Change.IndentationOffset = |
| Change.StartOfTokenColumn - |
| Change.StartOfBlockComment->StartOfTokenColumn; |
| } else { |
| LastBlockComment = nullptr; |
| } |
| } |
| } |
| |
| void WhitespaceManager::alignTrailingComments() { |
| unsigned MinColumn = 0; |
| unsigned MaxColumn = UINT_MAX; |
| unsigned StartOfSequence = 0; |
| bool BreakBeforeNext = false; |
| unsigned Newlines = 0; |
| for (unsigned i = 0, e = Changes.size(); i != e; ++i) { |
| if (Changes[i].StartOfBlockComment) |
| continue; |
| Newlines += Changes[i].NewlinesBefore; |
| if (!Changes[i].IsTrailingComment) |
| continue; |
| |
| unsigned ChangeMinColumn = Changes[i].StartOfTokenColumn; |
| unsigned ChangeMaxColumn = Style.ColumnLimit - Changes[i].TokenLength; |
| if (i + 1 != e && Changes[i + 1].ContinuesPPDirective) |
| ChangeMaxColumn -= 2; |
| // If this comment follows an } in column 0, it probably documents the |
| // closing of a namespace and we don't want to align it. |
| bool FollowsRBraceInColumn0 = i > 0 && Changes[i].NewlinesBefore == 0 && |
| Changes[i - 1].Kind == tok::r_brace && |
| Changes[i - 1].StartOfTokenColumn == 0; |
| bool WasAlignedWithStartOfNextLine = false; |
| if (Changes[i].NewlinesBefore == 1) { // A comment on its own line. |
| unsigned CommentColumn = SourceMgr.getSpellingColumnNumber( |
| Changes[i].OriginalWhitespaceRange.getEnd()); |
| for (unsigned j = i + 1; j != e; ++j) { |
| if (Changes[j].Kind != tok::comment) { // Skip over comments. |
| unsigned NextColumn = SourceMgr.getSpellingColumnNumber( |
| Changes[j].OriginalWhitespaceRange.getEnd()); |
| // The start of the next token was previously aligned with the |
| // start of this comment. |
| WasAlignedWithStartOfNextLine = |
| CommentColumn == NextColumn || |
| CommentColumn == NextColumn + Style.IndentWidth; |
| break; |
| } |
| } |
| } |
| if (!Style.AlignTrailingComments || FollowsRBraceInColumn0) { |
| alignTrailingComments(StartOfSequence, i, MinColumn); |
| MinColumn = ChangeMinColumn; |
| MaxColumn = ChangeMinColumn; |
| StartOfSequence = i; |
| } else if (BreakBeforeNext || Newlines > 1 || |
| (ChangeMinColumn > MaxColumn || ChangeMaxColumn < MinColumn) || |
| // Break the comment sequence if the previous line did not end |
| // in a trailing comment. |
| (Changes[i].NewlinesBefore == 1 && i > 0 && |
| !Changes[i - 1].IsTrailingComment) || |
| WasAlignedWithStartOfNextLine) { |
| alignTrailingComments(StartOfSequence, i, MinColumn); |
| MinColumn = ChangeMinColumn; |
| MaxColumn = ChangeMaxColumn; |
| StartOfSequence = i; |
| } else { |
| MinColumn = std::max(MinColumn, ChangeMinColumn); |
| MaxColumn = std::min(MaxColumn, ChangeMaxColumn); |
| } |
| BreakBeforeNext = |
| (i == 0) || (Changes[i].NewlinesBefore > 1) || |
| // Never start a sequence with a comment at the beginning of |
| // the line. |
| (Changes[i].NewlinesBefore == 1 && StartOfSequence == i); |
| Newlines = 0; |
| } |
| alignTrailingComments(StartOfSequence, Changes.size(), MinColumn); |
| } |
| |
| void WhitespaceManager::alignTrailingComments(unsigned Start, unsigned End, |
| unsigned Column) { |
| for (unsigned i = Start; i != End; ++i) { |
| int Shift = 0; |
| if (Changes[i].IsTrailingComment) { |
| Shift = Column - Changes[i].StartOfTokenColumn; |
| } |
| if (Changes[i].StartOfBlockComment) { |
| Shift = Changes[i].IndentationOffset + |
| Changes[i].StartOfBlockComment->StartOfTokenColumn - |
| Changes[i].StartOfTokenColumn; |
| } |
| assert(Shift >= 0); |
| Changes[i].Spaces += Shift; |
| if (i + 1 != End) |
| Changes[i + 1].PreviousEndOfTokenColumn += Shift; |
| Changes[i].StartOfTokenColumn += Shift; |
| } |
| } |
| |
| void WhitespaceManager::alignEscapedNewlines() { |
| unsigned MaxEndOfLine = |
| Style.AlignEscapedNewlinesLeft ? 0 : Style.ColumnLimit; |
| unsigned StartOfMacro = 0; |
| for (unsigned i = 1, e = Changes.size(); i < e; ++i) { |
| Change &C = Changes[i]; |
| if (C.NewlinesBefore > 0) { |
| if (C.ContinuesPPDirective) { |
| MaxEndOfLine = std::max(C.PreviousEndOfTokenColumn + 2, MaxEndOfLine); |
| } else { |
| alignEscapedNewlines(StartOfMacro + 1, i, MaxEndOfLine); |
| MaxEndOfLine = Style.AlignEscapedNewlinesLeft ? 0 : Style.ColumnLimit; |
| StartOfMacro = i; |
| } |
| } |
| } |
| alignEscapedNewlines(StartOfMacro + 1, Changes.size(), MaxEndOfLine); |
| } |
| |
| void WhitespaceManager::alignEscapedNewlines(unsigned Start, unsigned End, |
| unsigned Column) { |
| for (unsigned i = Start; i < End; ++i) { |
| Change &C = Changes[i]; |
| if (C.NewlinesBefore > 0) { |
| assert(C.ContinuesPPDirective); |
| if (C.PreviousEndOfTokenColumn + 1 > Column) |
| C.EscapedNewlineColumn = 0; |
| else |
| C.EscapedNewlineColumn = Column; |
| } |
| } |
| } |
| |
| void WhitespaceManager::generateChanges() { |
| for (unsigned i = 0, e = Changes.size(); i != e; ++i) { |
| const Change &C = Changes[i]; |
| if (i > 0) { |
| assert(Changes[i - 1].OriginalWhitespaceRange.getBegin() != |
| C.OriginalWhitespaceRange.getBegin() && |
| "Generating two replacements for the same location"); |
| } |
| if (C.CreateReplacement) { |
| std::string ReplacementText = C.PreviousLinePostfix; |
| if (C.ContinuesPPDirective) |
| appendNewlineText(ReplacementText, C.NewlinesBefore, |
| C.PreviousEndOfTokenColumn, C.EscapedNewlineColumn); |
| else |
| appendNewlineText(ReplacementText, C.NewlinesBefore); |
| appendIndentText(ReplacementText, C.IndentLevel, std::max(0, C.Spaces), |
| C.StartOfTokenColumn - std::max(0, C.Spaces)); |
| ReplacementText.append(C.CurrentLinePrefix); |
| storeReplacement(C.OriginalWhitespaceRange, ReplacementText); |
| } |
| } |
| } |
| |
| void WhitespaceManager::storeReplacement(const SourceRange &Range, |
| StringRef Text) { |
| unsigned WhitespaceLength = SourceMgr.getFileOffset(Range.getEnd()) - |
| SourceMgr.getFileOffset(Range.getBegin()); |
| // Don't create a replacement, if it does not change anything. |
| if (StringRef(SourceMgr.getCharacterData(Range.getBegin()), |
| WhitespaceLength) == Text) |
| return; |
| Replaces.insert(tooling::Replacement( |
| SourceMgr, CharSourceRange::getCharRange(Range), Text)); |
| } |
| |
| void WhitespaceManager::appendNewlineText(std::string &Text, |
| unsigned Newlines) { |
| for (unsigned i = 0; i < Newlines; ++i) |
| Text.append(UseCRLF ? "\r\n" : "\n"); |
| } |
| |
| void WhitespaceManager::appendNewlineText(std::string &Text, unsigned Newlines, |
| unsigned PreviousEndOfTokenColumn, |
| unsigned EscapedNewlineColumn) { |
| if (Newlines > 0) { |
| unsigned Offset = |
| std::min<int>(EscapedNewlineColumn - 1, PreviousEndOfTokenColumn); |
| for (unsigned i = 0; i < Newlines; ++i) { |
| Text.append(std::string(EscapedNewlineColumn - Offset - 1, ' ')); |
| Text.append(UseCRLF ? "\\\r\n" : "\\\n"); |
| Offset = 0; |
| } |
| } |
| } |
| |
| void WhitespaceManager::appendIndentText(std::string &Text, |
| unsigned IndentLevel, unsigned Spaces, |
| unsigned WhitespaceStartColumn) { |
| switch (Style.UseTab) { |
| case FormatStyle::UT_Never: |
| Text.append(std::string(Spaces, ' ')); |
| break; |
| case FormatStyle::UT_Always: { |
| unsigned FirstTabWidth = |
| Style.TabWidth - WhitespaceStartColumn % Style.TabWidth; |
| // Indent with tabs only when there's at least one full tab. |
| if (FirstTabWidth + Style.TabWidth <= Spaces) { |
| Spaces -= FirstTabWidth; |
| Text.append("\t"); |
| } |
| Text.append(std::string(Spaces / Style.TabWidth, '\t')); |
| Text.append(std::string(Spaces % Style.TabWidth, ' ')); |
| break; |
| } |
| case FormatStyle::UT_ForIndentation: |
| if (WhitespaceStartColumn == 0) { |
| unsigned Indentation = IndentLevel * Style.IndentWidth; |
| // This happens, e.g. when a line in a block comment is indented less than |
| // the first one. |
| if (Indentation > Spaces) |
| Indentation = Spaces; |
| unsigned Tabs = Indentation / Style.TabWidth; |
| Text.append(std::string(Tabs, '\t')); |
| Spaces -= Tabs * Style.TabWidth; |
| } |
| Text.append(std::string(Spaces, ' ')); |
| break; |
| } |
| } |
| |
| } // namespace format |
| } // namespace clang |
