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