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      1 //===--- ContinuationIndenter.cpp - Format C++ code -----------------------===//
      2 //
      3 //                     The LLVM Compiler Infrastructure
      4 //
      5 // This file is distributed under the University of Illinois Open Source
      6 // License. See LICENSE.TXT for details.
      7 //
      8 //===----------------------------------------------------------------------===//
      9 ///
     10 /// \file
     11 /// \brief This file implements the continuation indenter.
     12 ///
     13 //===----------------------------------------------------------------------===//
     14 
     15 #include "BreakableToken.h"
     16 #include "ContinuationIndenter.h"
     17 #include "WhitespaceManager.h"
     18 #include "clang/Basic/OperatorPrecedence.h"
     19 #include "clang/Basic/SourceManager.h"
     20 #include "clang/Format/Format.h"
     21 #include "llvm/Support/Debug.h"
     22 #include <string>
     23 
     24 #define DEBUG_TYPE "format-formatter"
     25 
     26 namespace clang {
     27 namespace format {
     28 
     29 // Returns the length of everything up to the first possible line break after
     30 // the ), ], } or > matching \c Tok.
     31 static unsigned getLengthToMatchingParen(const FormatToken &Tok) {
     32   if (!Tok.MatchingParen)
     33     return 0;
     34   FormatToken *End = Tok.MatchingParen;
     35   while (End->Next && !End->Next->CanBreakBefore) {
     36     End = End->Next;
     37   }
     38   return End->TotalLength - Tok.TotalLength + 1;
     39 }
     40 
     41 // Returns \c true if \c Tok is the "." or "->" of a call and starts the next
     42 // segment of a builder type call.
     43 static bool startsSegmentOfBuilderTypeCall(const FormatToken &Tok) {
     44   return Tok.isMemberAccess() && Tok.Previous && Tok.Previous->closesScope();
     45 }
     46 
     47 // Returns \c true if \c Current starts a new parameter.
     48 static bool startsNextParameter(const FormatToken &Current,
     49                                 const FormatStyle &Style) {
     50   const FormatToken &Previous = *Current.Previous;
     51   if (Current.Type == TT_CtorInitializerComma &&
     52       Style.BreakConstructorInitializersBeforeComma)
     53     return true;
     54   return Previous.is(tok::comma) && !Current.isTrailingComment() &&
     55          (Previous.Type != TT_CtorInitializerComma ||
     56           !Style.BreakConstructorInitializersBeforeComma);
     57 }
     58 
     59 ContinuationIndenter::ContinuationIndenter(const FormatStyle &Style,
     60                                            SourceManager &SourceMgr,
     61                                            WhitespaceManager &Whitespaces,
     62                                            encoding::Encoding Encoding,
     63                                            bool BinPackInconclusiveFunctions)
     64     : Style(Style), SourceMgr(SourceMgr), Whitespaces(Whitespaces),
     65       Encoding(Encoding),
     66       BinPackInconclusiveFunctions(BinPackInconclusiveFunctions),
     67       CommentPragmasRegex(Style.CommentPragmas) {}
     68 
     69 LineState ContinuationIndenter::getInitialState(unsigned FirstIndent,
     70                                                 const AnnotatedLine *Line,
     71                                                 bool DryRun) {
     72   LineState State;
     73   State.FirstIndent = FirstIndent;
     74   State.Column = FirstIndent;
     75   State.Line = Line;
     76   State.NextToken = Line->First;
     77   State.Stack.push_back(ParenState(FirstIndent, Line->Level, FirstIndent,
     78                                    /*AvoidBinPacking=*/false,
     79                                    /*NoLineBreak=*/false));
     80   State.LineContainsContinuedForLoopSection = false;
     81   State.StartOfStringLiteral = 0;
     82   State.StartOfLineLevel = 0;
     83   State.LowestLevelOnLine = 0;
     84   State.IgnoreStackForComparison = false;
     85 
     86   // The first token has already been indented and thus consumed.
     87   moveStateToNextToken(State, DryRun, /*Newline=*/false);
     88   return State;
     89 }
     90 
     91 bool ContinuationIndenter::canBreak(const LineState &State) {
     92   const FormatToken &Current = *State.NextToken;
     93   const FormatToken &Previous = *Current.Previous;
     94   assert(&Previous == Current.Previous);
     95   if (!Current.CanBreakBefore && !(State.Stack.back().BreakBeforeClosingBrace &&
     96                                    Current.closesBlockTypeList(Style)))
     97     return false;
     98   // The opening "{" of a braced list has to be on the same line as the first
     99   // element if it is nested in another braced init list or function call.
    100   if (!Current.MustBreakBefore && Previous.is(tok::l_brace) &&
    101       Previous.Type != TT_DictLiteral && Previous.BlockKind == BK_BracedInit &&
    102       Previous.Previous &&
    103       Previous.Previous->isOneOf(tok::l_brace, tok::l_paren, tok::comma))
    104     return false;
    105   // This prevents breaks like:
    106   //   ...
    107   //   SomeParameter, OtherParameter).DoSomething(
    108   //   ...
    109   // As they hide "DoSomething" and are generally bad for readability.
    110   if (Previous.opensScope() && Previous.isNot(tok::l_brace) &&
    111       State.LowestLevelOnLine < State.StartOfLineLevel)
    112     return false;
    113   if (Current.isMemberAccess() && State.Stack.back().ContainsUnwrappedBuilder)
    114     return false;
    115 
    116   // Don't create a 'hanging' indent if there are multiple blocks in a single
    117   // statement.
    118   if (Style.Language == FormatStyle::LK_JavaScript &&
    119       Previous.is(tok::l_brace) && State.Stack.size() > 1 &&
    120       State.Stack[State.Stack.size() - 2].JSFunctionInlined &&
    121       State.Stack[State.Stack.size() - 2].HasMultipleNestedBlocks)
    122     return false;
    123 
    124   return !State.Stack.back().NoLineBreak;
    125 }
    126 
    127 bool ContinuationIndenter::mustBreak(const LineState &State) {
    128   const FormatToken &Current = *State.NextToken;
    129   const FormatToken &Previous = *Current.Previous;
    130   if (Current.MustBreakBefore || Current.Type == TT_InlineASMColon)
    131     return true;
    132   if (State.Stack.back().BreakBeforeClosingBrace &&
    133       Current.closesBlockTypeList(Style))
    134     return true;
    135   if (Previous.is(tok::semi) && State.LineContainsContinuedForLoopSection)
    136     return true;
    137   if ((startsNextParameter(Current, Style) || Previous.is(tok::semi) ||
    138        (Style.BreakBeforeTernaryOperators &&
    139         (Current.is(tok::question) || (Current.Type == TT_ConditionalExpr &&
    140                                        Previous.isNot(tok::question)))) ||
    141        (!Style.BreakBeforeTernaryOperators &&
    142         (Previous.is(tok::question) || Previous.Type == TT_ConditionalExpr))) &&
    143       State.Stack.back().BreakBeforeParameter && !Current.isTrailingComment() &&
    144       !Current.isOneOf(tok::r_paren, tok::r_brace))
    145     return true;
    146   if (Style.AlwaysBreakBeforeMultilineStrings &&
    147       State.Column > State.Stack.back().Indent && // Breaking saves columns.
    148       !Previous.isOneOf(tok::kw_return, tok::lessless, tok::at) &&
    149       Previous.Type != TT_InlineASMColon &&
    150       Previous.Type != TT_ConditionalExpr && nextIsMultilineString(State))
    151     return true;
    152   if (((Previous.Type == TT_DictLiteral && Previous.is(tok::l_brace)) ||
    153        Previous.Type == TT_ArrayInitializerLSquare) &&
    154       Style.ColumnLimit > 0 &&
    155       getLengthToMatchingParen(Previous) + State.Column > getColumnLimit(State))
    156     return true;
    157   if (Current.Type == TT_CtorInitializerColon &&
    158       ((Style.AllowShortFunctionsOnASingleLine != FormatStyle::SFS_All) ||
    159        Style.BreakConstructorInitializersBeforeComma || Style.ColumnLimit != 0))
    160     return true;
    161 
    162   if (State.Column < getNewLineColumn(State))
    163     return false;
    164   if (!Style.BreakBeforeBinaryOperators) {
    165     // If we need to break somewhere inside the LHS of a binary expression, we
    166     // should also break after the operator. Otherwise, the formatting would
    167     // hide the operator precedence, e.g. in:
    168     //   if (aaaaaaaaaaaaaa ==
    169     //           bbbbbbbbbbbbbb && c) {..
    170     // For comparisons, we only apply this rule, if the LHS is a binary
    171     // expression itself as otherwise, the line breaks seem superfluous.
    172     // We need special cases for ">>" which we have split into two ">" while
    173     // lexing in order to make template parsing easier.
    174     //
    175     // FIXME: We'll need something similar for styles that break before binary
    176     // operators.
    177     bool IsComparison = (Previous.getPrecedence() == prec::Relational ||
    178                          Previous.getPrecedence() == prec::Equality) &&
    179                         Previous.Previous &&
    180                         Previous.Previous->Type != TT_BinaryOperator; // For >>.
    181     bool LHSIsBinaryExpr =
    182         Previous.Previous && Previous.Previous->EndsBinaryExpression;
    183     if (Previous.Type == TT_BinaryOperator &&
    184         (!IsComparison || LHSIsBinaryExpr) &&
    185         Current.Type != TT_BinaryOperator && // For >>.
    186         !Current.isTrailingComment() && !Previous.is(tok::lessless) &&
    187         Previous.getPrecedence() != prec::Assignment &&
    188         State.Stack.back().BreakBeforeParameter)
    189       return true;
    190   }
    191 
    192   // Same as above, but for the first "<<" operator.
    193   if (Current.is(tok::lessless) && Current.Type != TT_OverloadedOperator &&
    194       State.Stack.back().BreakBeforeParameter &&
    195       State.Stack.back().FirstLessLess == 0)
    196     return true;
    197 
    198   if (Current.Type == TT_SelectorName &&
    199       State.Stack.back().ObjCSelectorNameFound &&
    200       State.Stack.back().BreakBeforeParameter)
    201     return true;
    202   if (Previous.ClosesTemplateDeclaration && Current.NestingLevel == 0 &&
    203       !Current.isTrailingComment())
    204     return true;
    205 
    206   // If the return type spans multiple lines, wrap before the function name.
    207   if ((Current.Type == TT_FunctionDeclarationName ||
    208        Current.is(tok::kw_operator)) &&
    209       State.Stack.back().BreakBeforeParameter)
    210     return true;
    211 
    212   if (startsSegmentOfBuilderTypeCall(Current) &&
    213       (State.Stack.back().CallContinuation != 0 ||
    214        (State.Stack.back().BreakBeforeParameter &&
    215         State.Stack.back().ContainsUnwrappedBuilder)))
    216     return true;
    217 
    218   // The following could be precomputed as they do not depend on the state.
    219   // However, as they should take effect only if the UnwrappedLine does not fit
    220   // into the ColumnLimit, they are checked here in the ContinuationIndenter.
    221   if (Style.ColumnLimit != 0 && Previous.BlockKind == BK_Block &&
    222       Previous.is(tok::l_brace) && !Current.isOneOf(tok::r_brace, tok::comment))
    223     return true;
    224 
    225   return false;
    226 }
    227 
    228 unsigned ContinuationIndenter::addTokenToState(LineState &State, bool Newline,
    229                                                bool DryRun,
    230                                                unsigned ExtraSpaces) {
    231   const FormatToken &Current = *State.NextToken;
    232 
    233   assert(!State.Stack.empty());
    234   if ((Current.Type == TT_ImplicitStringLiteral &&
    235        (Current.Previous->Tok.getIdentifierInfo() == nullptr ||
    236         Current.Previous->Tok.getIdentifierInfo()->getPPKeywordID() ==
    237             tok::pp_not_keyword))) {
    238     // FIXME: Is this correct?
    239     int WhitespaceLength = SourceMgr.getSpellingColumnNumber(
    240                                State.NextToken->WhitespaceRange.getEnd()) -
    241                            SourceMgr.getSpellingColumnNumber(
    242                                State.NextToken->WhitespaceRange.getBegin());
    243     State.Column += WhitespaceLength;
    244     moveStateToNextToken(State, DryRun, /*Newline=*/false);
    245     return 0;
    246   }
    247 
    248   unsigned Penalty = 0;
    249   if (Newline)
    250     Penalty = addTokenOnNewLine(State, DryRun);
    251   else
    252     addTokenOnCurrentLine(State, DryRun, ExtraSpaces);
    253 
    254   return moveStateToNextToken(State, DryRun, Newline) + Penalty;
    255 }
    256 
    257 void ContinuationIndenter::addTokenOnCurrentLine(LineState &State, bool DryRun,
    258                                                  unsigned ExtraSpaces) {
    259   FormatToken &Current = *State.NextToken;
    260   const FormatToken &Previous = *State.NextToken->Previous;
    261   if (Current.is(tok::equal) &&
    262       (State.Line->First->is(tok::kw_for) || Current.NestingLevel == 0) &&
    263       State.Stack.back().VariablePos == 0) {
    264     State.Stack.back().VariablePos = State.Column;
    265     // Move over * and & if they are bound to the variable name.
    266     const FormatToken *Tok = &Previous;
    267     while (Tok && State.Stack.back().VariablePos >= Tok->ColumnWidth) {
    268       State.Stack.back().VariablePos -= Tok->ColumnWidth;
    269       if (Tok->SpacesRequiredBefore != 0)
    270         break;
    271       Tok = Tok->Previous;
    272     }
    273     if (Previous.PartOfMultiVariableDeclStmt)
    274       State.Stack.back().LastSpace = State.Stack.back().VariablePos;
    275   }
    276 
    277   unsigned Spaces = Current.SpacesRequiredBefore + ExtraSpaces;
    278 
    279   if (!DryRun)
    280     Whitespaces.replaceWhitespace(Current, /*Newlines=*/0, /*IndentLevel=*/0,
    281                                   Spaces, State.Column + Spaces);
    282 
    283   if (Current.Type == TT_SelectorName &&
    284       !State.Stack.back().ObjCSelectorNameFound) {
    285     if (Current.LongestObjCSelectorName == 0)
    286       State.Stack.back().AlignColons = false;
    287     else if (State.Stack.back().Indent + Current.LongestObjCSelectorName >
    288              State.Column + Spaces + Current.ColumnWidth)
    289       State.Stack.back().ColonPos =
    290           State.Stack.back().Indent + Current.LongestObjCSelectorName;
    291     else
    292       State.Stack.back().ColonPos = State.Column + Spaces + Current.ColumnWidth;
    293   }
    294 
    295   if (Previous.opensScope() && Previous.Type != TT_ObjCMethodExpr &&
    296       (Current.Type != TT_LineComment || Previous.BlockKind == BK_BracedInit))
    297     State.Stack.back().Indent = State.Column + Spaces;
    298   if (State.Stack.back().AvoidBinPacking && startsNextParameter(Current, Style))
    299     State.Stack.back().NoLineBreak = true;
    300   if (startsSegmentOfBuilderTypeCall(Current))
    301     State.Stack.back().ContainsUnwrappedBuilder = true;
    302 
    303   State.Column += Spaces;
    304   if (Current.isNot(tok::comment) && Previous.is(tok::l_paren) &&
    305       Previous.Previous && Previous.Previous->isOneOf(tok::kw_if, tok::kw_for))
    306     // Treat the condition inside an if as if it was a second function
    307     // parameter, i.e. let nested calls have a continuation indent.
    308     State.Stack.back().LastSpace = State.Column;
    309   else if (!Current.isOneOf(tok::comment, tok::caret) &&
    310            (Previous.is(tok::comma) ||
    311             (Previous.is(tok::colon) && Previous.Type == TT_ObjCMethodExpr)))
    312     State.Stack.back().LastSpace = State.Column;
    313   else if ((Previous.Type == TT_BinaryOperator ||
    314             Previous.Type == TT_ConditionalExpr ||
    315             Previous.Type == TT_CtorInitializerColon) &&
    316            ((Previous.getPrecedence() != prec::Assignment &&
    317              (Previous.isNot(tok::lessless) || Previous.OperatorIndex != 0 ||
    318               !Previous.LastOperator)) ||
    319             Current.StartsBinaryExpression))
    320     // Always indent relative to the RHS of the expression unless this is a
    321     // simple assignment without binary expression on the RHS. Also indent
    322     // relative to unary operators and the colons of constructor initializers.
    323     State.Stack.back().LastSpace = State.Column;
    324   else if (Previous.Type == TT_InheritanceColon) {
    325     State.Stack.back().Indent = State.Column;
    326     State.Stack.back().LastSpace = State.Column;
    327   } else if (Previous.opensScope()) {
    328     // If a function has a trailing call, indent all parameters from the
    329     // opening parenthesis. This avoids confusing indents like:
    330     //   OuterFunction(InnerFunctionCall( // break
    331     //       ParameterToInnerFunction))   // break
    332     //       .SecondInnerFunctionCall();
    333     bool HasTrailingCall = false;
    334     if (Previous.MatchingParen) {
    335       const FormatToken *Next = Previous.MatchingParen->getNextNonComment();
    336       HasTrailingCall = Next && Next->isMemberAccess();
    337     }
    338     if (HasTrailingCall &&
    339         State.Stack[State.Stack.size() - 2].CallContinuation == 0)
    340       State.Stack.back().LastSpace = State.Column;
    341   }
    342 }
    343 
    344 unsigned ContinuationIndenter::addTokenOnNewLine(LineState &State,
    345                                                  bool DryRun) {
    346   FormatToken &Current = *State.NextToken;
    347   const FormatToken &Previous = *State.NextToken->Previous;
    348 
    349   // Extra penalty that needs to be added because of the way certain line
    350   // breaks are chosen.
    351   unsigned Penalty = 0;
    352 
    353   const FormatToken *PreviousNonComment = Current.getPreviousNonComment();
    354   const FormatToken *NextNonComment = Previous.getNextNonComment();
    355   if (!NextNonComment)
    356     NextNonComment = &Current;
    357   // The first line break on any NestingLevel causes an extra penalty in order
    358   // prefer similar line breaks.
    359   if (!State.Stack.back().ContainsLineBreak)
    360     Penalty += 15;
    361   State.Stack.back().ContainsLineBreak = true;
    362 
    363   Penalty += State.NextToken->SplitPenalty;
    364 
    365   // Breaking before the first "<<" is generally not desirable if the LHS is
    366   // short. Also always add the penalty if the LHS is split over mutliple lines
    367   // to avoid unnecessary line breaks that just work around this penalty.
    368   if (NextNonComment->is(tok::lessless) &&
    369       State.Stack.back().FirstLessLess == 0 &&
    370       (State.Column <= Style.ColumnLimit / 3 ||
    371        State.Stack.back().BreakBeforeParameter))
    372     Penalty += Style.PenaltyBreakFirstLessLess;
    373 
    374   State.Column = getNewLineColumn(State);
    375   if (NextNonComment->isMemberAccess()) {
    376     if (State.Stack.back().CallContinuation == 0)
    377       State.Stack.back().CallContinuation = State.Column;
    378   } else if (NextNonComment->Type == TT_SelectorName) {
    379     if (!State.Stack.back().ObjCSelectorNameFound) {
    380       if (NextNonComment->LongestObjCSelectorName == 0) {
    381         State.Stack.back().AlignColons = false;
    382       } else {
    383         State.Stack.back().ColonPos =
    384             State.Stack.back().Indent + NextNonComment->LongestObjCSelectorName;
    385       }
    386     } else if (State.Stack.back().AlignColons &&
    387                State.Stack.back().ColonPos <= NextNonComment->ColumnWidth) {
    388       State.Stack.back().ColonPos = State.Column + NextNonComment->ColumnWidth;
    389     }
    390   } else if (PreviousNonComment && PreviousNonComment->is(tok::colon) &&
    391              (PreviousNonComment->Type == TT_ObjCMethodExpr ||
    392               PreviousNonComment->Type == TT_DictLiteral)) {
    393     // FIXME: This is hacky, find a better way. The problem is that in an ObjC
    394     // method expression, the block should be aligned to the line starting it,
    395     // e.g.:
    396     //   [aaaaaaaaaaaaaaa aaaaaaaaa: \\ break for some reason
    397     //                        ^(int *i) {
    398     //                            // ...
    399     //                        }];
    400     // Thus, we set LastSpace of the next higher NestingLevel, to which we move
    401     // when we consume all of the "}"'s FakeRParens at the "{".
    402     if (State.Stack.size() > 1)
    403       State.Stack[State.Stack.size() - 2].LastSpace =
    404           std::max(State.Stack.back().LastSpace, State.Stack.back().Indent) +
    405           Style.ContinuationIndentWidth;
    406   }
    407 
    408   if ((Previous.isOneOf(tok::comma, tok::semi) &&
    409        !State.Stack.back().AvoidBinPacking) ||
    410       Previous.Type == TT_BinaryOperator)
    411     State.Stack.back().BreakBeforeParameter = false;
    412   if (Previous.Type == TT_TemplateCloser && Current.NestingLevel == 0)
    413     State.Stack.back().BreakBeforeParameter = false;
    414   if (NextNonComment->is(tok::question) ||
    415       (PreviousNonComment && PreviousNonComment->is(tok::question)))
    416     State.Stack.back().BreakBeforeParameter = true;
    417 
    418   if (!DryRun) {
    419     unsigned Newlines = std::max(
    420         1u, std::min(Current.NewlinesBefore, Style.MaxEmptyLinesToKeep + 1));
    421     Whitespaces.replaceWhitespace(Current, Newlines,
    422                                   State.Stack.back().IndentLevel, State.Column,
    423                                   State.Column, State.Line->InPPDirective);
    424   }
    425 
    426   if (!Current.isTrailingComment())
    427     State.Stack.back().LastSpace = State.Column;
    428   State.StartOfLineLevel = Current.NestingLevel;
    429   State.LowestLevelOnLine = Current.NestingLevel;
    430 
    431   // Any break on this level means that the parent level has been broken
    432   // and we need to avoid bin packing there.
    433   bool JavaScriptFormat = Style.Language == FormatStyle::LK_JavaScript &&
    434                           Current.is(tok::r_brace) &&
    435                           State.Stack.size() > 1 &&
    436                           State.Stack[State.Stack.size() - 2].JSFunctionInlined;
    437   if (!JavaScriptFormat) {
    438     for (unsigned i = 0, e = State.Stack.size() - 1; i != e; ++i) {
    439       State.Stack[i].BreakBeforeParameter = true;
    440     }
    441   }
    442 
    443   if (PreviousNonComment &&
    444       !PreviousNonComment->isOneOf(tok::comma, tok::semi) &&
    445       PreviousNonComment->Type != TT_TemplateCloser &&
    446       PreviousNonComment->Type != TT_BinaryOperator &&
    447       Current.Type != TT_BinaryOperator && !PreviousNonComment->opensScope())
    448     State.Stack.back().BreakBeforeParameter = true;
    449 
    450   // If we break after { or the [ of an array initializer, we should also break
    451   // before the corresponding } or ].
    452   if (PreviousNonComment &&
    453       (PreviousNonComment->is(tok::l_brace) ||
    454        PreviousNonComment->Type == TT_ArrayInitializerLSquare))
    455     State.Stack.back().BreakBeforeClosingBrace = true;
    456 
    457   if (State.Stack.back().AvoidBinPacking) {
    458     // If we are breaking after '(', '{', '<', this is not bin packing
    459     // unless AllowAllParametersOfDeclarationOnNextLine is false or this is a
    460     // dict/object literal.
    461     if (!(Previous.isOneOf(tok::l_paren, tok::l_brace) ||
    462           Previous.Type == TT_BinaryOperator) ||
    463         (!Style.AllowAllParametersOfDeclarationOnNextLine &&
    464          State.Line->MustBeDeclaration) ||
    465         Previous.Type == TT_DictLiteral)
    466       State.Stack.back().BreakBeforeParameter = true;
    467   }
    468 
    469   return Penalty;
    470 }
    471 
    472 unsigned ContinuationIndenter::getNewLineColumn(const LineState &State) {
    473   if (!State.NextToken || !State.NextToken->Previous)
    474     return 0;
    475   FormatToken &Current = *State.NextToken;
    476   const FormatToken &Previous = *State.NextToken->Previous;
    477   // If we are continuing an expression, we want to use the continuation indent.
    478   unsigned ContinuationIndent =
    479       std::max(State.Stack.back().LastSpace, State.Stack.back().Indent) +
    480       Style.ContinuationIndentWidth;
    481   const FormatToken *PreviousNonComment = Current.getPreviousNonComment();
    482   const FormatToken *NextNonComment = Previous.getNextNonComment();
    483   if (!NextNonComment)
    484     NextNonComment = &Current;
    485   if (NextNonComment->is(tok::l_brace) && NextNonComment->BlockKind == BK_Block)
    486     return Current.NestingLevel == 0 ? State.FirstIndent
    487                                      : State.Stack.back().Indent;
    488   if (Current.isOneOf(tok::r_brace, tok::r_square)) {
    489     if (State.Stack.size() > 1 &&
    490         State.Stack[State.Stack.size() - 2].JSFunctionInlined)
    491       return State.FirstIndent;
    492     if (Current.closesBlockTypeList(Style) ||
    493         (Current.MatchingParen &&
    494          Current.MatchingParen->BlockKind == BK_BracedInit))
    495       return State.Stack[State.Stack.size() - 2].LastSpace;
    496     else
    497       return State.FirstIndent;
    498   }
    499   if (Current.is(tok::identifier) && Current.Next &&
    500       Current.Next->Type == TT_DictLiteral)
    501     return State.Stack.back().Indent;
    502   if (NextNonComment->isStringLiteral() && State.StartOfStringLiteral != 0)
    503     return State.StartOfStringLiteral;
    504   if (NextNonComment->is(tok::lessless) &&
    505       State.Stack.back().FirstLessLess != 0)
    506     return State.Stack.back().FirstLessLess;
    507   if (NextNonComment->isMemberAccess()) {
    508     if (State.Stack.back().CallContinuation == 0) {
    509       return ContinuationIndent;
    510     } else {
    511       return State.Stack.back().CallContinuation;
    512     }
    513   }
    514   if (State.Stack.back().QuestionColumn != 0 &&
    515       ((NextNonComment->is(tok::colon) &&
    516         NextNonComment->Type == TT_ConditionalExpr) ||
    517        Previous.Type == TT_ConditionalExpr))
    518     return State.Stack.back().QuestionColumn;
    519   if (Previous.is(tok::comma) && State.Stack.back().VariablePos != 0)
    520     return State.Stack.back().VariablePos;
    521   if ((PreviousNonComment && (PreviousNonComment->ClosesTemplateDeclaration ||
    522                               PreviousNonComment->Type == TT_AttributeParen)) ||
    523       (!Style.IndentWrappedFunctionNames &&
    524        (NextNonComment->is(tok::kw_operator) ||
    525         NextNonComment->Type == TT_FunctionDeclarationName)))
    526     return std::max(State.Stack.back().LastSpace, State.Stack.back().Indent);
    527   if (NextNonComment->Type == TT_SelectorName) {
    528     if (!State.Stack.back().ObjCSelectorNameFound) {
    529       if (NextNonComment->LongestObjCSelectorName == 0) {
    530         return State.Stack.back().Indent;
    531       } else {
    532         return State.Stack.back().Indent +
    533                NextNonComment->LongestObjCSelectorName -
    534                NextNonComment->ColumnWidth;
    535       }
    536     } else if (!State.Stack.back().AlignColons) {
    537       return State.Stack.back().Indent;
    538     } else if (State.Stack.back().ColonPos > NextNonComment->ColumnWidth) {
    539       return State.Stack.back().ColonPos - NextNonComment->ColumnWidth;
    540     } else {
    541       return State.Stack.back().Indent;
    542     }
    543   }
    544   if (NextNonComment->Type == TT_ArraySubscriptLSquare) {
    545     if (State.Stack.back().StartOfArraySubscripts != 0)
    546       return State.Stack.back().StartOfArraySubscripts;
    547     else
    548       return ContinuationIndent;
    549   }
    550   if (NextNonComment->Type == TT_StartOfName ||
    551       Previous.isOneOf(tok::coloncolon, tok::equal)) {
    552     return ContinuationIndent;
    553   }
    554   if (PreviousNonComment && PreviousNonComment->is(tok::colon) &&
    555       (PreviousNonComment->Type == TT_ObjCMethodExpr ||
    556        PreviousNonComment->Type == TT_DictLiteral))
    557     return ContinuationIndent;
    558   if (NextNonComment->Type == TT_CtorInitializerColon)
    559     return State.FirstIndent + Style.ConstructorInitializerIndentWidth;
    560   if (NextNonComment->Type == TT_CtorInitializerComma)
    561     return State.Stack.back().Indent;
    562   if (State.Stack.back().Indent == State.FirstIndent && PreviousNonComment &&
    563       PreviousNonComment->isNot(tok::r_brace))
    564     // Ensure that we fall back to the continuation indent width instead of
    565     // just flushing continuations left.
    566     return State.Stack.back().Indent + Style.ContinuationIndentWidth;
    567   return State.Stack.back().Indent;
    568 }
    569 
    570 unsigned ContinuationIndenter::moveStateToNextToken(LineState &State,
    571                                                     bool DryRun, bool Newline) {
    572   assert(State.Stack.size());
    573   const FormatToken &Current = *State.NextToken;
    574 
    575   if (Current.Type == TT_InheritanceColon)
    576     State.Stack.back().AvoidBinPacking = true;
    577   if (Current.is(tok::lessless) && Current.Type != TT_OverloadedOperator) {
    578     if (State.Stack.back().FirstLessLess == 0)
    579       State.Stack.back().FirstLessLess = State.Column;
    580     else
    581       State.Stack.back().LastOperatorWrapped = Newline;
    582   }
    583   if ((Current.Type == TT_BinaryOperator && Current.isNot(tok::lessless)) ||
    584       Current.Type == TT_ConditionalExpr)
    585     State.Stack.back().LastOperatorWrapped = Newline;
    586   if (Current.Type == TT_ArraySubscriptLSquare &&
    587       State.Stack.back().StartOfArraySubscripts == 0)
    588     State.Stack.back().StartOfArraySubscripts = State.Column;
    589   if ((Current.is(tok::question) && Style.BreakBeforeTernaryOperators) ||
    590       (Current.getPreviousNonComment() && Current.isNot(tok::colon) &&
    591        Current.getPreviousNonComment()->is(tok::question) &&
    592        !Style.BreakBeforeTernaryOperators))
    593     State.Stack.back().QuestionColumn = State.Column;
    594   if (!Current.opensScope() && !Current.closesScope())
    595     State.LowestLevelOnLine =
    596         std::min(State.LowestLevelOnLine, Current.NestingLevel);
    597   if (Current.isMemberAccess())
    598     State.Stack.back().StartOfFunctionCall =
    599         Current.LastOperator ? 0 : State.Column + Current.ColumnWidth;
    600   if (Current.Type == TT_SelectorName)
    601     State.Stack.back().ObjCSelectorNameFound = true;
    602   if (Current.Type == TT_CtorInitializerColon) {
    603     // Indent 2 from the column, so:
    604     // SomeClass::SomeClass()
    605     //     : First(...), ...
    606     //       Next(...)
    607     //       ^ line up here.
    608     State.Stack.back().Indent =
    609         State.Column + (Style.BreakConstructorInitializersBeforeComma ? 0 : 2);
    610     if (Style.ConstructorInitializerAllOnOneLineOrOnePerLine)
    611       State.Stack.back().AvoidBinPacking = true;
    612     State.Stack.back().BreakBeforeParameter = false;
    613   }
    614 
    615   // In ObjC method declaration we align on the ":" of parameters, but we need
    616   // to ensure that we indent parameters on subsequent lines by at least our
    617   // continuation indent width.
    618   if (Current.Type == TT_ObjCMethodSpecifier)
    619     State.Stack.back().Indent += Style.ContinuationIndentWidth;
    620 
    621   // Insert scopes created by fake parenthesis.
    622   const FormatToken *Previous = Current.getPreviousNonComment();
    623 
    624   // Add special behavior to support a format commonly used for JavaScript
    625   // closures:
    626   //   SomeFunction(function() {
    627   //     foo();
    628   //     bar();
    629   //   }, a, b, c);
    630   if (Style.Language == FormatStyle::LK_JavaScript) {
    631     if (Current.isNot(tok::comment) && Previous && Previous->is(tok::l_brace) &&
    632         State.Stack.size() > 1) {
    633       if (State.Stack[State.Stack.size() - 2].JSFunctionInlined && Newline) {
    634         for (unsigned i = 0, e = State.Stack.size() - 1; i != e; ++i) {
    635           State.Stack[i].NoLineBreak = true;
    636         }
    637       }
    638       State.Stack[State.Stack.size() - 2].JSFunctionInlined = false;
    639     }
    640     if (Current.TokenText == "function")
    641       State.Stack.back().JSFunctionInlined = !Newline;
    642   }
    643 
    644   moveStatePastFakeLParens(State, Newline);
    645   moveStatePastScopeOpener(State, Newline);
    646   moveStatePastScopeCloser(State);
    647   moveStatePastFakeRParens(State);
    648 
    649   if (Current.isStringLiteral() && State.StartOfStringLiteral == 0) {
    650     State.StartOfStringLiteral = State.Column;
    651   } else if (!Current.isOneOf(tok::comment, tok::identifier, tok::hash) &&
    652              !Current.isStringLiteral()) {
    653     State.StartOfStringLiteral = 0;
    654   }
    655 
    656   State.Column += Current.ColumnWidth;
    657   State.NextToken = State.NextToken->Next;
    658   unsigned Penalty = breakProtrudingToken(Current, State, DryRun);
    659   if (State.Column > getColumnLimit(State)) {
    660     unsigned ExcessCharacters = State.Column - getColumnLimit(State);
    661     Penalty += Style.PenaltyExcessCharacter * ExcessCharacters;
    662   }
    663 
    664   if (Current.Role)
    665     Current.Role->formatFromToken(State, this, DryRun);
    666   // If the previous has a special role, let it consume tokens as appropriate.
    667   // It is necessary to start at the previous token for the only implemented
    668   // role (comma separated list). That way, the decision whether or not to break
    669   // after the "{" is already done and both options are tried and evaluated.
    670   // FIXME: This is ugly, find a better way.
    671   if (Previous && Previous->Role)
    672     Penalty += Previous->Role->formatAfterToken(State, this, DryRun);
    673 
    674   return Penalty;
    675 }
    676 
    677 void ContinuationIndenter::moveStatePastFakeLParens(LineState &State,
    678                                                     bool Newline) {
    679   const FormatToken &Current = *State.NextToken;
    680   const FormatToken *Previous = Current.getPreviousNonComment();
    681 
    682   // Don't add extra indentation for the first fake parenthesis after
    683   // 'return', assignments or opening <({[. The indentation for these cases
    684   // is special cased.
    685   bool SkipFirstExtraIndent =
    686       (Previous && (Previous->opensScope() || Previous->is(tok::kw_return) ||
    687                     Previous->getPrecedence() == prec::Assignment ||
    688                     Previous->Type == TT_ObjCMethodExpr));
    689   for (SmallVectorImpl<prec::Level>::const_reverse_iterator
    690            I = Current.FakeLParens.rbegin(),
    691            E = Current.FakeLParens.rend();
    692        I != E; ++I) {
    693     ParenState NewParenState = State.Stack.back();
    694     NewParenState.ContainsLineBreak = false;
    695 
    696     // Indent from 'LastSpace' unless this the fake parentheses encapsulating a
    697     // builder type call after 'return'. If such a call is line-wrapped, we
    698     // commonly just want to indent from the start of the line.
    699     if (!Previous || Previous->isNot(tok::kw_return) || *I > 0)
    700       NewParenState.Indent =
    701           std::max(std::max(State.Column, NewParenState.Indent),
    702                    State.Stack.back().LastSpace);
    703 
    704     // Don't allow the RHS of an operator to be split over multiple lines unless
    705     // there is a line-break right after the operator.
    706     // Exclude relational operators, as there, it is always more desirable to
    707     // have the LHS 'left' of the RHS.
    708     if (Previous && Previous->getPrecedence() > prec::Assignment &&
    709         (Previous->Type == TT_BinaryOperator ||
    710          Previous->Type == TT_ConditionalExpr) &&
    711         Previous->getPrecedence() != prec::Relational) {
    712       bool BreakBeforeOperator = Previous->is(tok::lessless) ||
    713                                  (Previous->Type == TT_BinaryOperator &&
    714                                   Style.BreakBeforeBinaryOperators) ||
    715                                  (Previous->Type == TT_ConditionalExpr &&
    716                                   Style.BreakBeforeTernaryOperators);
    717       if ((!Newline && !BreakBeforeOperator) ||
    718           (!State.Stack.back().LastOperatorWrapped && BreakBeforeOperator))
    719         NewParenState.NoLineBreak = true;
    720     }
    721 
    722     // Do not indent relative to the fake parentheses inserted for "." or "->".
    723     // This is a special case to make the following to statements consistent:
    724     //   OuterFunction(InnerFunctionCall( // break
    725     //       ParameterToInnerFunction));
    726     //   OuterFunction(SomeObject.InnerFunctionCall( // break
    727     //       ParameterToInnerFunction));
    728     if (*I > prec::Unknown)
    729       NewParenState.LastSpace = std::max(NewParenState.LastSpace, State.Column);
    730     NewParenState.StartOfFunctionCall = State.Column;
    731 
    732     // Always indent conditional expressions. Never indent expression where
    733     // the 'operator' is ',', ';' or an assignment (i.e. *I <=
    734     // prec::Assignment) as those have different indentation rules. Indent
    735     // other expression, unless the indentation needs to be skipped.
    736     if (*I == prec::Conditional ||
    737         (!SkipFirstExtraIndent && *I > prec::Assignment &&
    738          !Style.BreakBeforeBinaryOperators))
    739       NewParenState.Indent += Style.ContinuationIndentWidth;
    740     if ((Previous && !Previous->opensScope()) || *I > prec::Comma)
    741       NewParenState.BreakBeforeParameter = false;
    742     State.Stack.push_back(NewParenState);
    743     SkipFirstExtraIndent = false;
    744   }
    745 }
    746 
    747 // Remove the fake r_parens after 'Tok'.
    748 static void consumeRParens(LineState& State, const FormatToken &Tok) {
    749   for (unsigned i = 0, e = Tok.FakeRParens; i != e; ++i) {
    750     unsigned VariablePos = State.Stack.back().VariablePos;
    751     assert(State.Stack.size() > 1);
    752     if (State.Stack.size() == 1) {
    753       // Do not pop the last element.
    754       break;
    755     }
    756     State.Stack.pop_back();
    757     State.Stack.back().VariablePos = VariablePos;
    758   }
    759 }
    760 
    761 // Returns whether 'Tok' opens or closes a scope requiring special handling
    762 // of the subsequent fake r_parens.
    763 //
    764 // For example, if this is an l_brace starting a nested block, we pretend (wrt.
    765 // to indentation) that we already consumed the corresponding r_brace. Thus, we
    766 // remove all ParenStates caused by fake parentheses that end at the r_brace.
    767 // The net effect of this is that we don't indent relative to the l_brace, if
    768 // the nested block is the last parameter of a function. This formats:
    769 //
    770 //   SomeFunction(a, [] {
    771 //     f();  // break
    772 //   });
    773 //
    774 // instead of:
    775 //   SomeFunction(a, [] {
    776 //                     f();  // break
    777 //                   });
    778 static bool fakeRParenSpecialCase(const LineState &State) {
    779   const FormatToken &Tok = *State.NextToken;
    780   if (!Tok.MatchingParen)
    781     return false;
    782   const FormatToken *Left = &Tok;
    783   if (Tok.isOneOf(tok::r_brace, tok::r_square))
    784     Left = Tok.MatchingParen;
    785   return !State.Stack.back().HasMultipleNestedBlocks &&
    786          Left->isOneOf(tok::l_brace, tok::l_square) &&
    787          (Left->BlockKind == BK_Block ||
    788           Left->Type == TT_ArrayInitializerLSquare ||
    789           Left->Type == TT_DictLiteral);
    790 }
    791 
    792 void ContinuationIndenter::moveStatePastFakeRParens(LineState &State) {
    793   // Don't remove FakeRParens attached to r_braces that surround nested blocks
    794   // as they will have been removed early (see above).
    795   if (fakeRParenSpecialCase(State))
    796     return;
    797 
    798   consumeRParens(State, *State.NextToken);
    799 }
    800 
    801 void ContinuationIndenter::moveStatePastScopeOpener(LineState &State,
    802                                                     bool Newline) {
    803   const FormatToken &Current = *State.NextToken;
    804   if (!Current.opensScope())
    805     return;
    806 
    807   if (Current.MatchingParen && Current.BlockKind == BK_Block) {
    808     moveStateToNewBlock(State);
    809     return;
    810   }
    811 
    812   unsigned NewIndent;
    813   unsigned NewIndentLevel = State.Stack.back().IndentLevel;
    814   bool AvoidBinPacking;
    815   bool BreakBeforeParameter = false;
    816   if (Current.is(tok::l_brace) || Current.Type == TT_ArrayInitializerLSquare) {
    817     if (fakeRParenSpecialCase(State))
    818       consumeRParens(State, *Current.MatchingParen);
    819 
    820     NewIndent = State.Stack.back().LastSpace;
    821     if (Current.opensBlockTypeList(Style)) {
    822       NewIndent += Style.IndentWidth;
    823       NewIndent = std::min(State.Column + 2, NewIndent);
    824       ++NewIndentLevel;
    825     } else {
    826       NewIndent += Style.ContinuationIndentWidth;
    827       NewIndent = std::min(State.Column + 1, NewIndent);
    828     }
    829     const FormatToken *NextNoComment = Current.getNextNonComment();
    830     AvoidBinPacking = Current.Type == TT_ArrayInitializerLSquare ||
    831                       Current.Type == TT_DictLiteral ||
    832                       Style.Language == FormatStyle::LK_Proto ||
    833                       !Style.BinPackParameters ||
    834                       (NextNoComment &&
    835                        NextNoComment->Type == TT_DesignatedInitializerPeriod);
    836   } else {
    837     NewIndent = Style.ContinuationIndentWidth +
    838                 std::max(State.Stack.back().LastSpace,
    839                          State.Stack.back().StartOfFunctionCall);
    840     AvoidBinPacking = !Style.BinPackParameters ||
    841                       (Style.ExperimentalAutoDetectBinPacking &&
    842                        (Current.PackingKind == PPK_OnePerLine ||
    843                         (!BinPackInconclusiveFunctions &&
    844                          Current.PackingKind == PPK_Inconclusive)));
    845     // If this '[' opens an ObjC call, determine whether all parameters fit
    846     // into one line and put one per line if they don't.
    847     if (Current.Type == TT_ObjCMethodExpr && Style.ColumnLimit != 0 &&
    848         getLengthToMatchingParen(Current) + State.Column >
    849             getColumnLimit(State))
    850       BreakBeforeParameter = true;
    851   }
    852   bool NoLineBreak = State.Stack.back().NoLineBreak ||
    853                      (Current.Type == TT_TemplateOpener &&
    854                       State.Stack.back().ContainsUnwrappedBuilder);
    855   State.Stack.push_back(ParenState(NewIndent, NewIndentLevel,
    856                                    State.Stack.back().LastSpace,
    857                                    AvoidBinPacking, NoLineBreak));
    858   State.Stack.back().BreakBeforeParameter = BreakBeforeParameter;
    859   State.Stack.back().HasMultipleNestedBlocks = Current.BlockParameterCount > 1;
    860 }
    861 
    862 void ContinuationIndenter::moveStatePastScopeCloser(LineState &State) {
    863   const FormatToken &Current = *State.NextToken;
    864   if (!Current.closesScope())
    865     return;
    866 
    867   // If we encounter a closing ), ], } or >, we can remove a level from our
    868   // stacks.
    869   if (State.Stack.size() > 1 &&
    870       (Current.isOneOf(tok::r_paren, tok::r_square) ||
    871        (Current.is(tok::r_brace) && State.NextToken != State.Line->First) ||
    872        State.NextToken->Type == TT_TemplateCloser))
    873     State.Stack.pop_back();
    874 
    875   if (Current.is(tok::r_square)) {
    876     // If this ends the array subscript expr, reset the corresponding value.
    877     const FormatToken *NextNonComment = Current.getNextNonComment();
    878     if (NextNonComment && NextNonComment->isNot(tok::l_square))
    879       State.Stack.back().StartOfArraySubscripts = 0;
    880   }
    881 }
    882 
    883 void ContinuationIndenter::moveStateToNewBlock(LineState &State) {
    884   // If we have already found more than one lambda introducers on this level, we
    885   // opt out of this because similarity between the lambdas is more important.
    886   if (fakeRParenSpecialCase(State))
    887     consumeRParens(State, *State.NextToken->MatchingParen);
    888 
    889   // For some reason, ObjC blocks are indented like continuations.
    890   unsigned NewIndent = State.Stack.back().LastSpace +
    891                        (State.NextToken->Type == TT_ObjCBlockLBrace
    892                             ? Style.ContinuationIndentWidth
    893                             : Style.IndentWidth);
    894   State.Stack.push_back(ParenState(
    895       NewIndent, /*NewIndentLevel=*/State.Stack.back().IndentLevel + 1,
    896       State.Stack.back().LastSpace, /*AvoidBinPacking=*/true,
    897       State.Stack.back().NoLineBreak));
    898   State.Stack.back().BreakBeforeParameter = true;
    899 }
    900 
    901 unsigned ContinuationIndenter::addMultilineToken(const FormatToken &Current,
    902                                                  LineState &State) {
    903   // Break before further function parameters on all levels.
    904   for (unsigned i = 0, e = State.Stack.size(); i != e; ++i)
    905     State.Stack[i].BreakBeforeParameter = true;
    906 
    907   unsigned ColumnsUsed = State.Column;
    908   // We can only affect layout of the first and the last line, so the penalty
    909   // for all other lines is constant, and we ignore it.
    910   State.Column = Current.LastLineColumnWidth;
    911 
    912   if (ColumnsUsed > getColumnLimit(State))
    913     return Style.PenaltyExcessCharacter * (ColumnsUsed - getColumnLimit(State));
    914   return 0;
    915 }
    916 
    917 static bool getRawStringLiteralPrefixPostfix(StringRef Text, StringRef &Prefix,
    918                                              StringRef &Postfix) {
    919   if (Text.startswith(Prefix = "R\"") || Text.startswith(Prefix = "uR\"") ||
    920       Text.startswith(Prefix = "UR\"") || Text.startswith(Prefix = "u8R\"") ||
    921       Text.startswith(Prefix = "LR\"")) {
    922     size_t ParenPos = Text.find('(');
    923     if (ParenPos != StringRef::npos) {
    924       StringRef Delimiter =
    925           Text.substr(Prefix.size(), ParenPos - Prefix.size());
    926       Prefix = Text.substr(0, ParenPos + 1);
    927       Postfix = Text.substr(Text.size() - 2 - Delimiter.size());
    928       return Postfix.front() == ')' && Postfix.back() == '"' &&
    929              Postfix.substr(1).startswith(Delimiter);
    930     }
    931   }
    932   return false;
    933 }
    934 
    935 unsigned ContinuationIndenter::breakProtrudingToken(const FormatToken &Current,
    936                                                     LineState &State,
    937                                                     bool DryRun) {
    938   // Don't break multi-line tokens other than block comments. Instead, just
    939   // update the state.
    940   if (Current.Type != TT_BlockComment && Current.IsMultiline)
    941     return addMultilineToken(Current, State);
    942 
    943   // Don't break implicit string literals.
    944   if (Current.Type == TT_ImplicitStringLiteral)
    945     return 0;
    946 
    947   if (!Current.isStringLiteral() && !Current.is(tok::comment))
    948     return 0;
    949 
    950   std::unique_ptr<BreakableToken> Token;
    951   unsigned StartColumn = State.Column - Current.ColumnWidth;
    952   unsigned ColumnLimit = getColumnLimit(State);
    953 
    954   if (Current.isStringLiteral()) {
    955     // Don't break string literals inside preprocessor directives (except for
    956     // #define directives, as their contents are stored in separate lines and
    957     // are not affected by this check).
    958     // This way we avoid breaking code with line directives and unknown
    959     // preprocessor directives that contain long string literals.
    960     if (State.Line->Type == LT_PreprocessorDirective)
    961       return 0;
    962     // Exempts unterminated string literals from line breaking. The user will
    963     // likely want to terminate the string before any line breaking is done.
    964     if (Current.IsUnterminatedLiteral)
    965       return 0;
    966 
    967     StringRef Text = Current.TokenText;
    968     StringRef Prefix;
    969     StringRef Postfix;
    970     bool IsNSStringLiteral = false;
    971     // FIXME: Handle whitespace between '_T', '(', '"..."', and ')'.
    972     // FIXME: Store Prefix and Suffix (or PrefixLength and SuffixLength to
    973     // reduce the overhead) for each FormatToken, which is a string, so that we
    974     // don't run multiple checks here on the hot path.
    975     if (Text.startswith("\"") && Current.Previous &&
    976         Current.Previous->is(tok::at)) {
    977       IsNSStringLiteral = true;
    978       Prefix = "@\"";
    979     }
    980     if ((Text.endswith(Postfix = "\"") &&
    981          (IsNSStringLiteral || Text.startswith(Prefix = "\"") ||
    982           Text.startswith(Prefix = "u\"") || Text.startswith(Prefix = "U\"") ||
    983           Text.startswith(Prefix = "u8\"") ||
    984           Text.startswith(Prefix = "L\""))) ||
    985         (Text.startswith(Prefix = "_T(\"") && Text.endswith(Postfix = "\")")) ||
    986         getRawStringLiteralPrefixPostfix(Text, Prefix, Postfix)) {
    987       Token.reset(new BreakableStringLiteral(
    988           Current, State.Line->Level, StartColumn, Prefix, Postfix,
    989           State.Line->InPPDirective, Encoding, Style));
    990     } else {
    991       return 0;
    992     }
    993   } else if (Current.Type == TT_BlockComment && Current.isTrailingComment()) {
    994     if (CommentPragmasRegex.match(Current.TokenText.substr(2)))
    995       return 0;
    996     Token.reset(new BreakableBlockComment(
    997         Current, State.Line->Level, StartColumn, Current.OriginalColumn,
    998         !Current.Previous, State.Line->InPPDirective, Encoding, Style));
    999   } else if (Current.Type == TT_LineComment &&
   1000              (Current.Previous == nullptr ||
   1001               Current.Previous->Type != TT_ImplicitStringLiteral)) {
   1002     if (CommentPragmasRegex.match(Current.TokenText.substr(2)))
   1003       return 0;
   1004     Token.reset(new BreakableLineComment(Current, State.Line->Level,
   1005                                          StartColumn, /*InPPDirective=*/false,
   1006                                          Encoding, Style));
   1007     // We don't insert backslashes when breaking line comments.
   1008     ColumnLimit = Style.ColumnLimit;
   1009   } else {
   1010     return 0;
   1011   }
   1012   if (Current.UnbreakableTailLength >= ColumnLimit)
   1013     return 0;
   1014 
   1015   unsigned RemainingSpace = ColumnLimit - Current.UnbreakableTailLength;
   1016   bool BreakInserted = false;
   1017   unsigned Penalty = 0;
   1018   unsigned RemainingTokenColumns = 0;
   1019   for (unsigned LineIndex = 0, EndIndex = Token->getLineCount();
   1020        LineIndex != EndIndex; ++LineIndex) {
   1021     if (!DryRun)
   1022       Token->replaceWhitespaceBefore(LineIndex, Whitespaces);
   1023     unsigned TailOffset = 0;
   1024     RemainingTokenColumns =
   1025         Token->getLineLengthAfterSplit(LineIndex, TailOffset, StringRef::npos);
   1026     while (RemainingTokenColumns > RemainingSpace) {
   1027       BreakableToken::Split Split =
   1028           Token->getSplit(LineIndex, TailOffset, ColumnLimit);
   1029       if (Split.first == StringRef::npos) {
   1030         // The last line's penalty is handled in addNextStateToQueue().
   1031         if (LineIndex < EndIndex - 1)
   1032           Penalty += Style.PenaltyExcessCharacter *
   1033                      (RemainingTokenColumns - RemainingSpace);
   1034         break;
   1035       }
   1036       assert(Split.first != 0);
   1037       unsigned NewRemainingTokenColumns = Token->getLineLengthAfterSplit(
   1038           LineIndex, TailOffset + Split.first + Split.second, StringRef::npos);
   1039 
   1040       // We can remove extra whitespace instead of breaking the line.
   1041       if (RemainingTokenColumns + 1 - Split.second <= RemainingSpace) {
   1042         RemainingTokenColumns = 0;
   1043         if (!DryRun)
   1044           Token->replaceWhitespace(LineIndex, TailOffset, Split, Whitespaces);
   1045         break;
   1046       }
   1047 
   1048       // When breaking before a tab character, it may be moved by a few columns,
   1049       // but will still be expanded to the next tab stop, so we don't save any
   1050       // columns.
   1051       if (NewRemainingTokenColumns == RemainingTokenColumns)
   1052         break;
   1053 
   1054       assert(NewRemainingTokenColumns < RemainingTokenColumns);
   1055       if (!DryRun)
   1056         Token->insertBreak(LineIndex, TailOffset, Split, Whitespaces);
   1057       Penalty += Current.SplitPenalty;
   1058       unsigned ColumnsUsed =
   1059           Token->getLineLengthAfterSplit(LineIndex, TailOffset, Split.first);
   1060       if (ColumnsUsed > ColumnLimit) {
   1061         Penalty += Style.PenaltyExcessCharacter * (ColumnsUsed - ColumnLimit);
   1062       }
   1063       TailOffset += Split.first + Split.second;
   1064       RemainingTokenColumns = NewRemainingTokenColumns;
   1065       BreakInserted = true;
   1066     }
   1067   }
   1068 
   1069   State.Column = RemainingTokenColumns;
   1070 
   1071   if (BreakInserted) {
   1072     // If we break the token inside a parameter list, we need to break before
   1073     // the next parameter on all levels, so that the next parameter is clearly
   1074     // visible. Line comments already introduce a break.
   1075     if (Current.Type != TT_LineComment) {
   1076       for (unsigned i = 0, e = State.Stack.size(); i != e; ++i)
   1077         State.Stack[i].BreakBeforeParameter = true;
   1078     }
   1079 
   1080     Penalty += Current.isStringLiteral() ? Style.PenaltyBreakString
   1081                                          : Style.PenaltyBreakComment;
   1082 
   1083     State.Stack.back().LastSpace = StartColumn;
   1084   }
   1085   return Penalty;
   1086 }
   1087 
   1088 unsigned ContinuationIndenter::getColumnLimit(const LineState &State) const {
   1089   // In preprocessor directives reserve two chars for trailing " \"
   1090   return Style.ColumnLimit - (State.Line->InPPDirective ? 2 : 0);
   1091 }
   1092 
   1093 bool ContinuationIndenter::nextIsMultilineString(const LineState &State) {
   1094   const FormatToken &Current = *State.NextToken;
   1095   if (!Current.isStringLiteral() || Current.Type == TT_ImplicitStringLiteral)
   1096     return false;
   1097   // We never consider raw string literals "multiline" for the purpose of
   1098   // AlwaysBreakBeforeMultilineStrings implementation as they are special-cased
   1099   // (see TokenAnnotator::mustBreakBefore().
   1100   if (Current.TokenText.startswith("R\""))
   1101     return false;
   1102   if (Current.IsMultiline)
   1103     return true;
   1104   if (Current.getNextNonComment() &&
   1105       Current.getNextNonComment()->isStringLiteral())
   1106     return true; // Implicit concatenation.
   1107   if (State.Column + Current.ColumnWidth + Current.UnbreakableTailLength >
   1108       Style.ColumnLimit)
   1109     return true; // String will be split.
   1110   return false;
   1111 }
   1112 
   1113 } // namespace format
   1114 } // namespace clang
   1115