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 "ContinuationIndenter.h"
16 #include "BreakableToken.h"
17 #include "FormatInternal.h"
18 #include "WhitespaceManager.h"
19 #include "clang/Basic/OperatorPrecedence.h"
20 #include "clang/Basic/SourceManager.h"
21 #include "clang/Format/Format.h"
22 #include "llvm/Support/Debug.h"
23 
24 #define DEBUG_TYPE "format-indenter"
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 static unsigned getLengthToNextOperator(const FormatToken &Tok) {
42   if (!Tok.NextOperator)
43     return 0;
44   return Tok.NextOperator->TotalLength - Tok.TotalLength;
45 }
46 
47 // Returns \c true if \c Tok is the "." or "->" of a call and starts the next
48 // segment of a builder type call.
49 static bool startsSegmentOfBuilderTypeCall(const FormatToken &Tok) {
50   return Tok.isMemberAccess() && Tok.Previous && Tok.Previous->closesScope();
51 }
52 
53 // Returns \c true if \c Current starts a new parameter.
54 static bool startsNextParameter(const FormatToken &Current,
55                                 const FormatStyle &Style) {
56   const FormatToken &Previous = *Current.Previous;
57   if (Current.is(TT_CtorInitializerComma) &&
58       Style.BreakConstructorInitializers == FormatStyle::BCIS_BeforeComma)
59     return true;
60   if (Style.Language == FormatStyle::LK_Proto && Current.is(TT_SelectorName))
61     return true;
62   return Previous.is(tok::comma) && !Current.isTrailingComment() &&
63          ((Previous.isNot(TT_CtorInitializerComma) ||
64            Style.BreakConstructorInitializers !=
65                FormatStyle::BCIS_BeforeComma) &&
66           (Previous.isNot(TT_InheritanceComma) ||
67            !Style.BreakBeforeInheritanceComma));
68 }
69 
70 static bool opensProtoMessageField(const FormatToken &LessTok,
71                                    const FormatStyle &Style) {
72   if (LessTok.isNot(tok::less))
73     return false;
74   return Style.Language == FormatStyle::LK_TextProto ||
75          (Style.Language == FormatStyle::LK_Proto &&
76           (LessTok.NestingLevel > 0 ||
77            (LessTok.Previous && LessTok.Previous->is(tok::equal))));
78 }
79 
80 // Returns the delimiter of a raw string literal, or None if TokenText is not
81 // the text of a raw string literal. The delimiter could be the empty string.
82 // For example, the delimiter of R"deli(cont)deli" is deli.
83 static llvm::Optional<StringRef> getRawStringDelimiter(StringRef TokenText) {
84   if (TokenText.size() < 5 // The smallest raw string possible is 'R"()"'.
85       || !TokenText.startswith("R\"") || !TokenText.endswith("\""))
86     return None;
87 
88   // A raw string starts with 'R"<delimiter>(' and delimiter is ascii and has
89   // size at most 16 by the standard, so the first '(' must be among the first
90   // 19 bytes.
91   size_t LParenPos = TokenText.substr(0, 19).find_first_of('(');
92   if (LParenPos == StringRef::npos)
93     return None;
94   StringRef Delimiter = TokenText.substr(2, LParenPos - 2);
95 
96   // Check that the string ends in ')Delimiter"'.
97   size_t RParenPos = TokenText.size() - Delimiter.size() - 2;
98   if (TokenText[RParenPos] != ')')
99     return None;
100   if (!TokenText.substr(RParenPos + 1).startswith(Delimiter))
101     return None;
102   return Delimiter;
103 }
104 
105 RawStringFormatStyleManager::RawStringFormatStyleManager(
106     const FormatStyle &CodeStyle) {
107   for (const auto &RawStringFormat : CodeStyle.RawStringFormats) {
108     FormatStyle Style;
109     if (!getPredefinedStyle(RawStringFormat.BasedOnStyle,
110                             RawStringFormat.Language, &Style)) {
111       Style = getLLVMStyle();
112       Style.Language = RawStringFormat.Language;
113     }
114     Style.ColumnLimit = CodeStyle.ColumnLimit;
115     DelimiterStyle.insert({RawStringFormat.Delimiter, Style});
116   }
117 }
118 
119 llvm::Optional<FormatStyle>
120 RawStringFormatStyleManager::get(StringRef Delimiter) const {
121   auto It = DelimiterStyle.find(Delimiter);
122   if (It == DelimiterStyle.end())
123     return None;
124   return It->second;
125 }
126 
127 ContinuationIndenter::ContinuationIndenter(const FormatStyle &Style,
128                                            const AdditionalKeywords &Keywords,
129                                            const SourceManager &SourceMgr,
130                                            WhitespaceManager &Whitespaces,
131                                            encoding::Encoding Encoding,
132                                            bool BinPackInconclusiveFunctions)
133     : Style(Style), Keywords(Keywords), SourceMgr(SourceMgr),
134       Whitespaces(Whitespaces), Encoding(Encoding),
135       BinPackInconclusiveFunctions(BinPackInconclusiveFunctions),
136       CommentPragmasRegex(Style.CommentPragmas), RawStringFormats(Style) {}
137 
138 LineState ContinuationIndenter::getInitialState(unsigned FirstIndent,
139                                                 unsigned FirstStartColumn,
140                                                 const AnnotatedLine *Line,
141                                                 bool DryRun) {
142   LineState State;
143   State.FirstIndent = FirstIndent;
144   if (FirstStartColumn && Line->First->NewlinesBefore == 0)
145     State.Column = FirstStartColumn;
146   else
147     State.Column = FirstIndent;
148   // With preprocessor directive indentation, the line starts on column 0
149   // since it's indented after the hash, but FirstIndent is set to the
150   // preprocessor indent.
151   if (Style.IndentPPDirectives == FormatStyle::PPDIS_AfterHash &&
152       (Line->Type == LT_PreprocessorDirective ||
153        Line->Type == LT_ImportStatement))
154     State.Column = 0;
155   State.Line = Line;
156   State.NextToken = Line->First;
157   State.Stack.push_back(ParenState(FirstIndent, FirstIndent,
158                                    /*AvoidBinPacking=*/false,
159                                    /*NoLineBreak=*/false));
160   State.LineContainsContinuedForLoopSection = false;
161   State.NoContinuation = false;
162   State.StartOfStringLiteral = 0;
163   State.StartOfLineLevel = 0;
164   State.LowestLevelOnLine = 0;
165   State.IgnoreStackForComparison = false;
166 
167   if (Style.Language == FormatStyle::LK_TextProto) {
168     // We need this in order to deal with the bin packing of text fields at
169     // global scope.
170     State.Stack.back().AvoidBinPacking = true;
171     State.Stack.back().BreakBeforeParameter = true;
172   }
173 
174   // The first token has already been indented and thus consumed.
175   moveStateToNextToken(State, DryRun, /*Newline=*/false);
176   return State;
177 }
178 
179 bool ContinuationIndenter::canBreak(const LineState &State) {
180   const FormatToken &Current = *State.NextToken;
181   const FormatToken &Previous = *Current.Previous;
182   assert(&Previous == Current.Previous);
183   if (!Current.CanBreakBefore && !(State.Stack.back().BreakBeforeClosingBrace &&
184                                    Current.closesBlockOrBlockTypeList(Style)))
185     return false;
186   // The opening "{" of a braced list has to be on the same line as the first
187   // element if it is nested in another braced init list or function call.
188   if (!Current.MustBreakBefore && Previous.is(tok::l_brace) &&
189       Previous.isNot(TT_DictLiteral) && Previous.BlockKind == BK_BracedInit &&
190       Previous.Previous &&
191       Previous.Previous->isOneOf(tok::l_brace, tok::l_paren, tok::comma))
192     return false;
193   // This prevents breaks like:
194   //   ...
195   //   SomeParameter, OtherParameter).DoSomething(
196   //   ...
197   // As they hide "DoSomething" and are generally bad for readability.
198   if (Previous.opensScope() && Previous.isNot(tok::l_brace) &&
199       State.LowestLevelOnLine < State.StartOfLineLevel &&
200       State.LowestLevelOnLine < Current.NestingLevel)
201     return false;
202   if (Current.isMemberAccess() && State.Stack.back().ContainsUnwrappedBuilder)
203     return false;
204 
205   // Don't create a 'hanging' indent if there are multiple blocks in a single
206   // statement.
207   if (Previous.is(tok::l_brace) && State.Stack.size() > 1 &&
208       State.Stack[State.Stack.size() - 2].NestedBlockInlined &&
209       State.Stack[State.Stack.size() - 2].HasMultipleNestedBlocks)
210     return false;
211 
212   // Don't break after very short return types (e.g. "void") as that is often
213   // unexpected.
214   if (Current.is(TT_FunctionDeclarationName) && State.Column < 6) {
215     if (Style.AlwaysBreakAfterReturnType == FormatStyle::RTBS_None)
216       return false;
217   }
218 
219   // If binary operators are moved to the next line (including commas for some
220   // styles of constructor initializers), that's always ok.
221   if (!Current.isOneOf(TT_BinaryOperator, tok::comma) &&
222       State.Stack.back().NoLineBreakInOperand)
223     return false;
224 
225   return !State.Stack.back().NoLineBreak;
226 }
227 
228 bool ContinuationIndenter::mustBreak(const LineState &State) {
229   const FormatToken &Current = *State.NextToken;
230   const FormatToken &Previous = *Current.Previous;
231   if (Current.MustBreakBefore || Current.is(TT_InlineASMColon))
232     return true;
233   if (State.Stack.back().BreakBeforeClosingBrace &&
234       Current.closesBlockOrBlockTypeList(Style))
235     return true;
236   if (Previous.is(tok::semi) && State.LineContainsContinuedForLoopSection)
237     return true;
238   if ((startsNextParameter(Current, Style) || Previous.is(tok::semi) ||
239        (Previous.is(TT_TemplateCloser) && Current.is(TT_StartOfName) &&
240         Style.isCpp() &&
241         // FIXME: This is a temporary workaround for the case where clang-format
242         // sets BreakBeforeParameter to avoid bin packing and this creates a
243         // completely unnecessary line break after a template type that isn't
244         // line-wrapped.
245         (Previous.NestingLevel == 1 || Style.BinPackParameters)) ||
246        (Style.BreakBeforeTernaryOperators && Current.is(TT_ConditionalExpr) &&
247         Previous.isNot(tok::question)) ||
248        (!Style.BreakBeforeTernaryOperators &&
249         Previous.is(TT_ConditionalExpr))) &&
250       State.Stack.back().BreakBeforeParameter && !Current.isTrailingComment() &&
251       !Current.isOneOf(tok::r_paren, tok::r_brace))
252     return true;
253   if (((Previous.is(TT_DictLiteral) && Previous.is(tok::l_brace)) ||
254        (Previous.is(TT_ArrayInitializerLSquare) &&
255         Previous.ParameterCount > 1) ||
256        opensProtoMessageField(Previous, Style)) &&
257       Style.ColumnLimit > 0 &&
258       getLengthToMatchingParen(Previous) + State.Column - 1 >
259           getColumnLimit(State))
260     return true;
261 
262   const FormatToken &BreakConstructorInitializersToken =
263       Style.BreakConstructorInitializers == FormatStyle::BCIS_AfterColon
264           ? Previous
265           : Current;
266   if (BreakConstructorInitializersToken.is(TT_CtorInitializerColon) &&
267       (State.Column + State.Line->Last->TotalLength - Previous.TotalLength >
268            getColumnLimit(State) ||
269        State.Stack.back().BreakBeforeParameter) &&
270       (Style.AllowShortFunctionsOnASingleLine != FormatStyle::SFS_All ||
271        Style.BreakConstructorInitializers != FormatStyle::BCIS_BeforeColon ||
272        Style.ColumnLimit != 0))
273     return true;
274 
275   if (Current.is(TT_ObjCMethodExpr) && !Previous.is(TT_SelectorName) &&
276       State.Line->startsWith(TT_ObjCMethodSpecifier))
277     return true;
278   if (Current.is(TT_SelectorName) && State.Stack.back().ObjCSelectorNameFound &&
279       State.Stack.back().BreakBeforeParameter)
280     return true;
281 
282   unsigned NewLineColumn = getNewLineColumn(State);
283   if (Current.isMemberAccess() && Style.ColumnLimit != 0 &&
284       State.Column + getLengthToNextOperator(Current) > Style.ColumnLimit &&
285       (State.Column > NewLineColumn ||
286        Current.NestingLevel < State.StartOfLineLevel))
287     return true;
288 
289   if (startsSegmentOfBuilderTypeCall(Current) &&
290       (State.Stack.back().CallContinuation != 0 ||
291        State.Stack.back().BreakBeforeParameter) &&
292       // JavaScript is treated different here as there is a frequent pattern:
293       //   SomeFunction(function() {
294       //     ...
295       //   }.bind(...));
296       // FIXME: We should find a more generic solution to this problem.
297       !(State.Column <= NewLineColumn &&
298         Style.Language == FormatStyle::LK_JavaScript))
299     return true;
300 
301   if (State.Column <= NewLineColumn)
302     return false;
303 
304   if (Style.AlwaysBreakBeforeMultilineStrings &&
305       (NewLineColumn == State.FirstIndent + Style.ContinuationIndentWidth ||
306        Previous.is(tok::comma) || Current.NestingLevel < 2) &&
307       !Previous.isOneOf(tok::kw_return, tok::lessless, tok::at) &&
308       !Previous.isOneOf(TT_InlineASMColon, TT_ConditionalExpr) &&
309       nextIsMultilineString(State))
310     return true;
311 
312   // Using CanBreakBefore here and below takes care of the decision whether the
313   // current style uses wrapping before or after operators for the given
314   // operator.
315   if (Previous.is(TT_BinaryOperator) && Current.CanBreakBefore) {
316     // If we need to break somewhere inside the LHS of a binary expression, we
317     // should also break after the operator. Otherwise, the formatting would
318     // hide the operator precedence, e.g. in:
319     //   if (aaaaaaaaaaaaaa ==
320     //           bbbbbbbbbbbbbb && c) {..
321     // For comparisons, we only apply this rule, if the LHS is a binary
322     // expression itself as otherwise, the line breaks seem superfluous.
323     // We need special cases for ">>" which we have split into two ">" while
324     // lexing in order to make template parsing easier.
325     bool IsComparison = (Previous.getPrecedence() == prec::Relational ||
326                          Previous.getPrecedence() == prec::Equality) &&
327                         Previous.Previous &&
328                         Previous.Previous->isNot(TT_BinaryOperator); // For >>.
329     bool LHSIsBinaryExpr =
330         Previous.Previous && Previous.Previous->EndsBinaryExpression;
331     if ((!IsComparison || LHSIsBinaryExpr) && !Current.isTrailingComment() &&
332         Previous.getPrecedence() != prec::Assignment &&
333         State.Stack.back().BreakBeforeParameter)
334       return true;
335   } else if (Current.is(TT_BinaryOperator) && Current.CanBreakBefore &&
336              State.Stack.back().BreakBeforeParameter) {
337     return true;
338   }
339 
340   // Same as above, but for the first "<<" operator.
341   if (Current.is(tok::lessless) && Current.isNot(TT_OverloadedOperator) &&
342       State.Stack.back().BreakBeforeParameter &&
343       State.Stack.back().FirstLessLess == 0)
344     return true;
345 
346   if (Current.NestingLevel == 0 && !Current.isTrailingComment()) {
347     // Always break after "template <...>" and leading annotations. This is only
348     // for cases where the entire line does not fit on a single line as a
349     // different LineFormatter would be used otherwise.
350     if (Previous.ClosesTemplateDeclaration)
351       return true;
352     if (Previous.is(TT_FunctionAnnotationRParen))
353       return true;
354     if (Previous.is(TT_LeadingJavaAnnotation) && Current.isNot(tok::l_paren) &&
355         Current.isNot(TT_LeadingJavaAnnotation))
356       return true;
357   }
358 
359   // If the return type spans multiple lines, wrap before the function name.
360   if ((Current.is(TT_FunctionDeclarationName) ||
361        (Current.is(tok::kw_operator) && !Previous.is(tok::coloncolon))) &&
362       !Previous.is(tok::kw_template) && State.Stack.back().BreakBeforeParameter)
363     return true;
364 
365   // The following could be precomputed as they do not depend on the state.
366   // However, as they should take effect only if the UnwrappedLine does not fit
367   // into the ColumnLimit, they are checked here in the ContinuationIndenter.
368   if (Style.ColumnLimit != 0 && Previous.BlockKind == BK_Block &&
369       Previous.is(tok::l_brace) && !Current.isOneOf(tok::r_brace, tok::comment))
370     return true;
371 
372   if (Current.is(tok::lessless) &&
373       ((Previous.is(tok::identifier) && Previous.TokenText == "endl") ||
374        (Previous.Tok.isLiteral() && (Previous.TokenText.endswith("\\n\"") ||
375                                      Previous.TokenText == "\'\\n\'"))))
376     return true;
377 
378   if (Previous.is(TT_BlockComment) && Previous.IsMultiline)
379     return true;
380 
381   if (State.NoContinuation)
382     return true;
383 
384   return false;
385 }
386 
387 unsigned ContinuationIndenter::addTokenToState(LineState &State, bool Newline,
388                                                bool DryRun,
389                                                unsigned ExtraSpaces) {
390   const FormatToken &Current = *State.NextToken;
391 
392   assert(!State.Stack.empty());
393   State.NoContinuation = false;
394 
395   if ((Current.is(TT_ImplicitStringLiteral) &&
396        (Current.Previous->Tok.getIdentifierInfo() == nullptr ||
397         Current.Previous->Tok.getIdentifierInfo()->getPPKeywordID() ==
398             tok::pp_not_keyword))) {
399     unsigned EndColumn =
400         SourceMgr.getSpellingColumnNumber(Current.WhitespaceRange.getEnd());
401     if (Current.LastNewlineOffset != 0) {
402       // If there is a newline within this token, the final column will solely
403       // determined by the current end column.
404       State.Column = EndColumn;
405     } else {
406       unsigned StartColumn =
407           SourceMgr.getSpellingColumnNumber(Current.WhitespaceRange.getBegin());
408       assert(EndColumn >= StartColumn);
409       State.Column += EndColumn - StartColumn;
410     }
411     moveStateToNextToken(State, DryRun, /*Newline=*/false);
412     return 0;
413   }
414 
415   unsigned Penalty = 0;
416   if (Newline)
417     Penalty = addTokenOnNewLine(State, DryRun);
418   else
419     addTokenOnCurrentLine(State, DryRun, ExtraSpaces);
420 
421   return moveStateToNextToken(State, DryRun, Newline) + Penalty;
422 }
423 
424 void ContinuationIndenter::addTokenOnCurrentLine(LineState &State, bool DryRun,
425                                                  unsigned ExtraSpaces) {
426   FormatToken &Current = *State.NextToken;
427   const FormatToken &Previous = *State.NextToken->Previous;
428   if (Current.is(tok::equal) &&
429       (State.Line->First->is(tok::kw_for) || Current.NestingLevel == 0) &&
430       State.Stack.back().VariablePos == 0) {
431     State.Stack.back().VariablePos = State.Column;
432     // Move over * and & if they are bound to the variable name.
433     const FormatToken *Tok = &Previous;
434     while (Tok && State.Stack.back().VariablePos >= Tok->ColumnWidth) {
435       State.Stack.back().VariablePos -= Tok->ColumnWidth;
436       if (Tok->SpacesRequiredBefore != 0)
437         break;
438       Tok = Tok->Previous;
439     }
440     if (Previous.PartOfMultiVariableDeclStmt)
441       State.Stack.back().LastSpace = State.Stack.back().VariablePos;
442   }
443 
444   unsigned Spaces = Current.SpacesRequiredBefore + ExtraSpaces;
445 
446   // Indent preprocessor directives after the hash if required.
447   int PPColumnCorrection = 0;
448   if (Style.IndentPPDirectives == FormatStyle::PPDIS_AfterHash &&
449       Previous.is(tok::hash) && State.FirstIndent > 0 &&
450       (State.Line->Type == LT_PreprocessorDirective ||
451        State.Line->Type == LT_ImportStatement)) {
452     Spaces += State.FirstIndent;
453 
454     // For preprocessor indent with tabs, State.Column will be 1 because of the
455     // hash. This causes second-level indents onward to have an extra space
456     // after the tabs. We avoid this misalignment by subtracting 1 from the
457     // column value passed to replaceWhitespace().
458     if (Style.UseTab != FormatStyle::UT_Never)
459       PPColumnCorrection = -1;
460   }
461 
462   if (!DryRun)
463     Whitespaces.replaceWhitespace(Current, /*Newlines=*/0, Spaces,
464                                   State.Column + Spaces + PPColumnCorrection);
465 
466   // If "BreakBeforeInheritanceComma" mode, don't break within the inheritance
467   // declaration unless there is multiple inheritance.
468   if (Style.BreakBeforeInheritanceComma && Current.is(TT_InheritanceColon))
469     State.Stack.back().NoLineBreak = true;
470 
471   if (Current.is(TT_SelectorName) &&
472       !State.Stack.back().ObjCSelectorNameFound) {
473     unsigned MinIndent =
474         std::max(State.FirstIndent + Style.ContinuationIndentWidth,
475                  State.Stack.back().Indent);
476     unsigned FirstColonPos = State.Column + Spaces + Current.ColumnWidth;
477     if (Current.LongestObjCSelectorName == 0)
478       State.Stack.back().AlignColons = false;
479     else if (MinIndent + Current.LongestObjCSelectorName > FirstColonPos)
480       State.Stack.back().ColonPos = MinIndent + Current.LongestObjCSelectorName;
481     else
482       State.Stack.back().ColonPos = FirstColonPos;
483   }
484 
485   // In "AlwaysBreak" mode, enforce wrapping directly after the parenthesis by
486   // disallowing any further line breaks if there is no line break after the
487   // opening parenthesis. Don't break if it doesn't conserve columns.
488   if (Style.AlignAfterOpenBracket == FormatStyle::BAS_AlwaysBreak &&
489       Previous.isOneOf(tok::l_paren, TT_TemplateOpener, tok::l_square) &&
490       State.Column > getNewLineColumn(State) &&
491       (!Previous.Previous || !Previous.Previous->isOneOf(
492                                  tok::kw_for, tok::kw_while, tok::kw_switch)) &&
493       // Don't do this for simple (no expressions) one-argument function calls
494       // as that feels like needlessly wasting whitespace, e.g.:
495       //
496       //   caaaaaaaaaaaall(
497       //       caaaaaaaaaaaall(
498       //           caaaaaaaaaaaall(
499       //               caaaaaaaaaaaaaaaaaaaaaaall(aaaaaaaaaaaaaa, aaaaaaaaa))));
500       Current.FakeLParens.size() > 0 &&
501       Current.FakeLParens.back() > prec::Unknown)
502     State.Stack.back().NoLineBreak = true;
503   if (Previous.is(TT_TemplateString) && Previous.opensScope())
504     State.Stack.back().NoLineBreak = true;
505 
506   if (Style.AlignAfterOpenBracket != FormatStyle::BAS_DontAlign &&
507       Previous.opensScope() && Previous.isNot(TT_ObjCMethodExpr) &&
508       (Current.isNot(TT_LineComment) || Previous.BlockKind == BK_BracedInit))
509     State.Stack.back().Indent = State.Column + Spaces;
510   if (State.Stack.back().AvoidBinPacking && startsNextParameter(Current, Style))
511     State.Stack.back().NoLineBreak = true;
512   if (startsSegmentOfBuilderTypeCall(Current) &&
513       State.Column > getNewLineColumn(State))
514     State.Stack.back().ContainsUnwrappedBuilder = true;
515 
516   if (Current.is(TT_LambdaArrow) && Style.Language == FormatStyle::LK_Java)
517     State.Stack.back().NoLineBreak = true;
518   if (Current.isMemberAccess() && Previous.is(tok::r_paren) &&
519       (Previous.MatchingParen &&
520        (Previous.TotalLength - Previous.MatchingParen->TotalLength > 10)))
521     // If there is a function call with long parameters, break before trailing
522     // calls. This prevents things like:
523     //   EXPECT_CALL(SomeLongParameter).Times(
524     //       2);
525     // We don't want to do this for short parameters as they can just be
526     // indexes.
527     State.Stack.back().NoLineBreak = true;
528 
529   // Don't allow the RHS of an operator to be split over multiple lines unless
530   // there is a line-break right after the operator.
531   // Exclude relational operators, as there, it is always more desirable to
532   // have the LHS 'left' of the RHS.
533   const FormatToken *P = Current.getPreviousNonComment();
534   if (!Current.is(tok::comment) && P &&
535       (P->isOneOf(TT_BinaryOperator, tok::comma) ||
536        (P->is(TT_ConditionalExpr) && P->is(tok::colon))) &&
537       !P->isOneOf(TT_OverloadedOperator, TT_CtorInitializerComma) &&
538       P->getPrecedence() != prec::Assignment &&
539       P->getPrecedence() != prec::Relational) {
540     bool BreakBeforeOperator =
541         P->MustBreakBefore || P->is(tok::lessless) ||
542         (P->is(TT_BinaryOperator) &&
543          Style.BreakBeforeBinaryOperators != FormatStyle::BOS_None) ||
544         (P->is(TT_ConditionalExpr) && Style.BreakBeforeTernaryOperators);
545     // Don't do this if there are only two operands. In these cases, there is
546     // always a nice vertical separation between them and the extra line break
547     // does not help.
548     bool HasTwoOperands =
549         P->OperatorIndex == 0 && !P->NextOperator && !P->is(TT_ConditionalExpr);
550     if ((!BreakBeforeOperator && !(HasTwoOperands && Style.AlignOperands)) ||
551         (!State.Stack.back().LastOperatorWrapped && BreakBeforeOperator))
552       State.Stack.back().NoLineBreakInOperand = true;
553   }
554 
555   State.Column += Spaces;
556   if (Current.isNot(tok::comment) && Previous.is(tok::l_paren) &&
557       Previous.Previous &&
558       (Previous.Previous->isOneOf(tok::kw_if, tok::kw_for) ||
559        Previous.Previous->endsSequence(tok::kw_constexpr, tok::kw_if))) {
560     // Treat the condition inside an if as if it was a second function
561     // parameter, i.e. let nested calls have a continuation indent.
562     State.Stack.back().LastSpace = State.Column;
563     State.Stack.back().NestedBlockIndent = State.Column;
564   } else if (!Current.isOneOf(tok::comment, tok::caret) &&
565              ((Previous.is(tok::comma) &&
566                !Previous.is(TT_OverloadedOperator)) ||
567               (Previous.is(tok::colon) && Previous.is(TT_ObjCMethodExpr)))) {
568     State.Stack.back().LastSpace = State.Column;
569   } else if (Previous.is(TT_CtorInitializerColon) &&
570              Style.BreakConstructorInitializers ==
571                  FormatStyle::BCIS_AfterColon) {
572     State.Stack.back().Indent = State.Column;
573     State.Stack.back().LastSpace = State.Column;
574   } else if ((Previous.isOneOf(TT_BinaryOperator, TT_ConditionalExpr,
575                                TT_CtorInitializerColon)) &&
576              ((Previous.getPrecedence() != prec::Assignment &&
577                (Previous.isNot(tok::lessless) || Previous.OperatorIndex != 0 ||
578                 Previous.NextOperator)) ||
579               Current.StartsBinaryExpression)) {
580     // Indent relative to the RHS of the expression unless this is a simple
581     // assignment without binary expression on the RHS. Also indent relative to
582     // unary operators and the colons of constructor initializers.
583     State.Stack.back().LastSpace = State.Column;
584   } else if (Previous.is(TT_InheritanceColon)) {
585     State.Stack.back().Indent = State.Column;
586     State.Stack.back().LastSpace = State.Column;
587   } else if (Previous.opensScope()) {
588     // If a function has a trailing call, indent all parameters from the
589     // opening parenthesis. This avoids confusing indents like:
590     //   OuterFunction(InnerFunctionCall( // break
591     //       ParameterToInnerFunction))   // break
592     //       .SecondInnerFunctionCall();
593     bool HasTrailingCall = false;
594     if (Previous.MatchingParen) {
595       const FormatToken *Next = Previous.MatchingParen->getNextNonComment();
596       HasTrailingCall = Next && Next->isMemberAccess();
597     }
598     if (HasTrailingCall && State.Stack.size() > 1 &&
599         State.Stack[State.Stack.size() - 2].CallContinuation == 0)
600       State.Stack.back().LastSpace = State.Column;
601   }
602 }
603 
604 unsigned ContinuationIndenter::addTokenOnNewLine(LineState &State,
605                                                  bool DryRun) {
606   FormatToken &Current = *State.NextToken;
607   const FormatToken &Previous = *State.NextToken->Previous;
608 
609   // Extra penalty that needs to be added because of the way certain line
610   // breaks are chosen.
611   unsigned Penalty = 0;
612 
613   const FormatToken *PreviousNonComment = Current.getPreviousNonComment();
614   const FormatToken *NextNonComment = Previous.getNextNonComment();
615   if (!NextNonComment)
616     NextNonComment = &Current;
617   // The first line break on any NestingLevel causes an extra penalty in order
618   // prefer similar line breaks.
619   if (!State.Stack.back().ContainsLineBreak)
620     Penalty += 15;
621   State.Stack.back().ContainsLineBreak = true;
622 
623   Penalty += State.NextToken->SplitPenalty;
624 
625   // Breaking before the first "<<" is generally not desirable if the LHS is
626   // short. Also always add the penalty if the LHS is split over multiple lines
627   // to avoid unnecessary line breaks that just work around this penalty.
628   if (NextNonComment->is(tok::lessless) &&
629       State.Stack.back().FirstLessLess == 0 &&
630       (State.Column <= Style.ColumnLimit / 3 ||
631        State.Stack.back().BreakBeforeParameter))
632     Penalty += Style.PenaltyBreakFirstLessLess;
633 
634   State.Column = getNewLineColumn(State);
635 
636   // Indent nested blocks relative to this column, unless in a very specific
637   // JavaScript special case where:
638   //
639   //   var loooooong_name =
640   //       function() {
641   //     // code
642   //   }
643   //
644   // is common and should be formatted like a free-standing function. The same
645   // goes for wrapping before the lambda return type arrow.
646   if (!Current.is(TT_LambdaArrow) &&
647       (Style.Language != FormatStyle::LK_JavaScript ||
648        Current.NestingLevel != 0 || !PreviousNonComment ||
649        !PreviousNonComment->is(tok::equal) ||
650        !Current.isOneOf(Keywords.kw_async, Keywords.kw_function)))
651     State.Stack.back().NestedBlockIndent = State.Column;
652 
653   if (NextNonComment->isMemberAccess()) {
654     if (State.Stack.back().CallContinuation == 0)
655       State.Stack.back().CallContinuation = State.Column;
656   } else if (NextNonComment->is(TT_SelectorName)) {
657     if (!State.Stack.back().ObjCSelectorNameFound) {
658       if (NextNonComment->LongestObjCSelectorName == 0) {
659         State.Stack.back().AlignColons = false;
660       } else {
661         State.Stack.back().ColonPos =
662             (Style.IndentWrappedFunctionNames
663                  ? std::max(State.Stack.back().Indent,
664                             State.FirstIndent + Style.ContinuationIndentWidth)
665                  : State.Stack.back().Indent) +
666             NextNonComment->LongestObjCSelectorName;
667       }
668     } else if (State.Stack.back().AlignColons &&
669                State.Stack.back().ColonPos <= NextNonComment->ColumnWidth) {
670       State.Stack.back().ColonPos = State.Column + NextNonComment->ColumnWidth;
671     }
672   } else if (PreviousNonComment && PreviousNonComment->is(tok::colon) &&
673              PreviousNonComment->isOneOf(TT_ObjCMethodExpr, TT_DictLiteral)) {
674     // FIXME: This is hacky, find a better way. The problem is that in an ObjC
675     // method expression, the block should be aligned to the line starting it,
676     // e.g.:
677     //   [aaaaaaaaaaaaaaa aaaaaaaaa: \\ break for some reason
678     //                        ^(int *i) {
679     //                            // ...
680     //                        }];
681     // Thus, we set LastSpace of the next higher NestingLevel, to which we move
682     // when we consume all of the "}"'s FakeRParens at the "{".
683     if (State.Stack.size() > 1)
684       State.Stack[State.Stack.size() - 2].LastSpace =
685           std::max(State.Stack.back().LastSpace, State.Stack.back().Indent) +
686           Style.ContinuationIndentWidth;
687   }
688 
689   if ((PreviousNonComment &&
690        PreviousNonComment->isOneOf(tok::comma, tok::semi) &&
691        !State.Stack.back().AvoidBinPacking) ||
692       Previous.is(TT_BinaryOperator))
693     State.Stack.back().BreakBeforeParameter = false;
694   if (Previous.isOneOf(TT_TemplateCloser, TT_JavaAnnotation) &&
695       Current.NestingLevel == 0)
696     State.Stack.back().BreakBeforeParameter = false;
697   if (NextNonComment->is(tok::question) ||
698       (PreviousNonComment && PreviousNonComment->is(tok::question)))
699     State.Stack.back().BreakBeforeParameter = true;
700   if (Current.is(TT_BinaryOperator) && Current.CanBreakBefore)
701     State.Stack.back().BreakBeforeParameter = false;
702 
703   if (!DryRun) {
704     unsigned Newlines = std::max(
705         1u, std::min(Current.NewlinesBefore, Style.MaxEmptyLinesToKeep + 1));
706     bool ContinuePPDirective =
707         State.Line->InPPDirective && State.Line->Type != LT_ImportStatement;
708     Whitespaces.replaceWhitespace(Current, Newlines, State.Column, State.Column,
709                                   ContinuePPDirective);
710   }
711 
712   if (!Current.isTrailingComment())
713     State.Stack.back().LastSpace = State.Column;
714   if (Current.is(tok::lessless))
715     // If we are breaking before a "<<", we always want to indent relative to
716     // RHS. This is necessary only for "<<", as we special-case it and don't
717     // always indent relative to the RHS.
718     State.Stack.back().LastSpace += 3; // 3 -> width of "<< ".
719 
720   State.StartOfLineLevel = Current.NestingLevel;
721   State.LowestLevelOnLine = Current.NestingLevel;
722 
723   // Any break on this level means that the parent level has been broken
724   // and we need to avoid bin packing there.
725   bool NestedBlockSpecialCase =
726       !Style.isCpp() && Current.is(tok::r_brace) && State.Stack.size() > 1 &&
727       State.Stack[State.Stack.size() - 2].NestedBlockInlined;
728   if (!NestedBlockSpecialCase)
729     for (unsigned i = 0, e = State.Stack.size() - 1; i != e; ++i)
730       State.Stack[i].BreakBeforeParameter = true;
731 
732   if (PreviousNonComment &&
733       !PreviousNonComment->isOneOf(tok::comma, tok::colon, tok::semi) &&
734       (PreviousNonComment->isNot(TT_TemplateCloser) ||
735        Current.NestingLevel != 0) &&
736       !PreviousNonComment->isOneOf(
737           TT_BinaryOperator, TT_FunctionAnnotationRParen, TT_JavaAnnotation,
738           TT_LeadingJavaAnnotation) &&
739       Current.isNot(TT_BinaryOperator) && !PreviousNonComment->opensScope())
740     State.Stack.back().BreakBeforeParameter = true;
741 
742   // If we break after { or the [ of an array initializer, we should also break
743   // before the corresponding } or ].
744   if (PreviousNonComment &&
745       (PreviousNonComment->isOneOf(tok::l_brace, TT_ArrayInitializerLSquare) ||
746        opensProtoMessageField(*PreviousNonComment, Style)))
747     State.Stack.back().BreakBeforeClosingBrace = true;
748 
749   if (State.Stack.back().AvoidBinPacking) {
750     // If we are breaking after '(', '{', '<', this is not bin packing
751     // unless AllowAllParametersOfDeclarationOnNextLine is false or this is a
752     // dict/object literal.
753     if (!Previous.isOneOf(tok::l_paren, tok::l_brace, TT_BinaryOperator) ||
754         (!Style.AllowAllParametersOfDeclarationOnNextLine &&
755          State.Line->MustBeDeclaration) ||
756         Previous.is(TT_DictLiteral))
757       State.Stack.back().BreakBeforeParameter = true;
758   }
759 
760   return Penalty;
761 }
762 
763 unsigned ContinuationIndenter::getNewLineColumn(const LineState &State) {
764   if (!State.NextToken || !State.NextToken->Previous)
765     return 0;
766   FormatToken &Current = *State.NextToken;
767   const FormatToken &Previous = *Current.Previous;
768   // If we are continuing an expression, we want to use the continuation indent.
769   unsigned ContinuationIndent =
770       std::max(State.Stack.back().LastSpace, State.Stack.back().Indent) +
771       Style.ContinuationIndentWidth;
772   const FormatToken *PreviousNonComment = Current.getPreviousNonComment();
773   const FormatToken *NextNonComment = Previous.getNextNonComment();
774   if (!NextNonComment)
775     NextNonComment = &Current;
776 
777   // Java specific bits.
778   if (Style.Language == FormatStyle::LK_Java &&
779       Current.isOneOf(Keywords.kw_implements, Keywords.kw_extends))
780     return std::max(State.Stack.back().LastSpace,
781                     State.Stack.back().Indent + Style.ContinuationIndentWidth);
782 
783   if (NextNonComment->is(tok::l_brace) && NextNonComment->BlockKind == BK_Block)
784     return Current.NestingLevel == 0 ? State.FirstIndent
785                                      : State.Stack.back().Indent;
786   if ((Current.isOneOf(tok::r_brace, tok::r_square) ||
787        (Current.is(tok::greater) &&
788         (Style.Language == FormatStyle::LK_Proto ||
789          Style.Language == FormatStyle::LK_TextProto))) &&
790       State.Stack.size() > 1) {
791     if (Current.closesBlockOrBlockTypeList(Style))
792       return State.Stack[State.Stack.size() - 2].NestedBlockIndent;
793     if (Current.MatchingParen &&
794         Current.MatchingParen->BlockKind == BK_BracedInit)
795       return State.Stack[State.Stack.size() - 2].LastSpace;
796     return State.FirstIndent;
797   }
798   // Indent a closing parenthesis at the previous level if followed by a semi or
799   // opening brace. This allows indentations such as:
800   //     foo(
801   //       a,
802   //     );
803   //     function foo(
804   //       a,
805   //     ) {
806   //       code(); //
807   //     }
808   if (Current.is(tok::r_paren) && State.Stack.size() > 1 &&
809       (!Current.Next || Current.Next->isOneOf(tok::semi, tok::l_brace)))
810     return State.Stack[State.Stack.size() - 2].LastSpace;
811   if (NextNonComment->is(TT_TemplateString) && NextNonComment->closesScope())
812     return State.Stack[State.Stack.size() - 2].LastSpace;
813   if (Current.is(tok::identifier) && Current.Next &&
814       (Current.Next->is(TT_DictLiteral) ||
815        ((Style.Language == FormatStyle::LK_Proto ||
816          Style.Language == FormatStyle::LK_TextProto) &&
817         Current.Next->isOneOf(TT_TemplateOpener, tok::l_brace))))
818     return State.Stack.back().Indent;
819   if (NextNonComment->is(TT_ObjCStringLiteral) &&
820       State.StartOfStringLiteral != 0)
821     return State.StartOfStringLiteral - 1;
822   if (NextNonComment->isStringLiteral() && State.StartOfStringLiteral != 0)
823     return State.StartOfStringLiteral;
824   if (NextNonComment->is(tok::lessless) &&
825       State.Stack.back().FirstLessLess != 0)
826     return State.Stack.back().FirstLessLess;
827   if (NextNonComment->isMemberAccess()) {
828     if (State.Stack.back().CallContinuation == 0)
829       return ContinuationIndent;
830     return State.Stack.back().CallContinuation;
831   }
832   if (State.Stack.back().QuestionColumn != 0 &&
833       ((NextNonComment->is(tok::colon) &&
834         NextNonComment->is(TT_ConditionalExpr)) ||
835        Previous.is(TT_ConditionalExpr)))
836     return State.Stack.back().QuestionColumn;
837   if (Previous.is(tok::comma) && State.Stack.back().VariablePos != 0)
838     return State.Stack.back().VariablePos;
839   if ((PreviousNonComment &&
840        (PreviousNonComment->ClosesTemplateDeclaration ||
841         PreviousNonComment->isOneOf(
842             TT_AttributeParen, TT_FunctionAnnotationRParen, TT_JavaAnnotation,
843             TT_LeadingJavaAnnotation))) ||
844       (!Style.IndentWrappedFunctionNames &&
845        NextNonComment->isOneOf(tok::kw_operator, TT_FunctionDeclarationName)))
846     return std::max(State.Stack.back().LastSpace, State.Stack.back().Indent);
847   if (NextNonComment->is(TT_SelectorName)) {
848     if (!State.Stack.back().ObjCSelectorNameFound) {
849       if (NextNonComment->LongestObjCSelectorName == 0)
850         return State.Stack.back().Indent;
851       return (Style.IndentWrappedFunctionNames
852                   ? std::max(State.Stack.back().Indent,
853                              State.FirstIndent + Style.ContinuationIndentWidth)
854                   : State.Stack.back().Indent) +
855              NextNonComment->LongestObjCSelectorName -
856              NextNonComment->ColumnWidth;
857     }
858     if (!State.Stack.back().AlignColons)
859       return State.Stack.back().Indent;
860     if (State.Stack.back().ColonPos > NextNonComment->ColumnWidth)
861       return State.Stack.back().ColonPos - NextNonComment->ColumnWidth;
862     return State.Stack.back().Indent;
863   }
864   if (NextNonComment->is(tok::colon) && NextNonComment->is(TT_ObjCMethodExpr))
865     return State.Stack.back().ColonPos;
866   if (NextNonComment->is(TT_ArraySubscriptLSquare)) {
867     if (State.Stack.back().StartOfArraySubscripts != 0)
868       return State.Stack.back().StartOfArraySubscripts;
869     return ContinuationIndent;
870   }
871 
872   // This ensure that we correctly format ObjC methods calls without inputs,
873   // i.e. where the last element isn't selector like: [callee method];
874   if (NextNonComment->is(tok::identifier) && NextNonComment->FakeRParens == 0 &&
875       NextNonComment->Next && NextNonComment->Next->is(TT_ObjCMethodExpr))
876     return State.Stack.back().Indent;
877 
878   if (NextNonComment->isOneOf(TT_StartOfName, TT_PointerOrReference) ||
879       Previous.isOneOf(tok::coloncolon, tok::equal, TT_JsTypeColon))
880     return ContinuationIndent;
881   if (PreviousNonComment && PreviousNonComment->is(tok::colon) &&
882       PreviousNonComment->isOneOf(TT_ObjCMethodExpr, TT_DictLiteral))
883     return ContinuationIndent;
884   if (NextNonComment->is(TT_CtorInitializerComma))
885     return State.Stack.back().Indent;
886   if (PreviousNonComment && PreviousNonComment->is(TT_CtorInitializerColon) &&
887       Style.BreakConstructorInitializers == FormatStyle::BCIS_AfterColon)
888     return State.Stack.back().Indent;
889   if (NextNonComment->isOneOf(TT_CtorInitializerColon, TT_InheritanceColon,
890                               TT_InheritanceComma))
891     return State.FirstIndent + Style.ConstructorInitializerIndentWidth;
892   if (Previous.is(tok::r_paren) && !Current.isBinaryOperator() &&
893       !Current.isOneOf(tok::colon, tok::comment))
894     return ContinuationIndent;
895   if (State.Stack.back().Indent == State.FirstIndent && PreviousNonComment &&
896       PreviousNonComment->isNot(tok::r_brace))
897     // Ensure that we fall back to the continuation indent width instead of
898     // just flushing continuations left.
899     return State.Stack.back().Indent + Style.ContinuationIndentWidth;
900   return State.Stack.back().Indent;
901 }
902 
903 unsigned ContinuationIndenter::moveStateToNextToken(LineState &State,
904                                                     bool DryRun, bool Newline) {
905   assert(State.Stack.size());
906   const FormatToken &Current = *State.NextToken;
907 
908   if (Current.isOneOf(tok::comma, TT_BinaryOperator))
909     State.Stack.back().NoLineBreakInOperand = false;
910   if (Current.is(TT_InheritanceColon))
911     State.Stack.back().AvoidBinPacking = true;
912   if (Current.is(tok::lessless) && Current.isNot(TT_OverloadedOperator)) {
913     if (State.Stack.back().FirstLessLess == 0)
914       State.Stack.back().FirstLessLess = State.Column;
915     else
916       State.Stack.back().LastOperatorWrapped = Newline;
917   }
918   if (Current.is(TT_BinaryOperator) && Current.isNot(tok::lessless))
919     State.Stack.back().LastOperatorWrapped = Newline;
920   if (Current.is(TT_ConditionalExpr) && Current.Previous &&
921       !Current.Previous->is(TT_ConditionalExpr))
922     State.Stack.back().LastOperatorWrapped = Newline;
923   if (Current.is(TT_ArraySubscriptLSquare) &&
924       State.Stack.back().StartOfArraySubscripts == 0)
925     State.Stack.back().StartOfArraySubscripts = State.Column;
926   if (Style.BreakBeforeTernaryOperators && Current.is(tok::question))
927     State.Stack.back().QuestionColumn = State.Column;
928   if (!Style.BreakBeforeTernaryOperators && Current.isNot(tok::colon)) {
929     const FormatToken *Previous = Current.Previous;
930     while (Previous && Previous->isTrailingComment())
931       Previous = Previous->Previous;
932     if (Previous && Previous->is(tok::question))
933       State.Stack.back().QuestionColumn = State.Column;
934   }
935   if (!Current.opensScope() && !Current.closesScope() &&
936       !Current.is(TT_PointerOrReference))
937     State.LowestLevelOnLine =
938         std::min(State.LowestLevelOnLine, Current.NestingLevel);
939   if (Current.isMemberAccess())
940     State.Stack.back().StartOfFunctionCall =
941         !Current.NextOperator ? 0 : State.Column;
942   if (Current.is(TT_SelectorName)) {
943     State.Stack.back().ObjCSelectorNameFound = true;
944     if (Style.IndentWrappedFunctionNames) {
945       State.Stack.back().Indent =
946           State.FirstIndent + Style.ContinuationIndentWidth;
947     }
948   }
949   if (Current.is(TT_CtorInitializerColon) &&
950       Style.BreakConstructorInitializers != FormatStyle::BCIS_AfterColon) {
951     // Indent 2 from the column, so:
952     // SomeClass::SomeClass()
953     //     : First(...), ...
954     //       Next(...)
955     //       ^ line up here.
956     State.Stack.back().Indent =
957         State.Column +
958         (Style.BreakConstructorInitializers == FormatStyle::BCIS_BeforeComma
959              ? 0
960              : 2);
961     State.Stack.back().NestedBlockIndent = State.Stack.back().Indent;
962     if (Style.ConstructorInitializerAllOnOneLineOrOnePerLine)
963       State.Stack.back().AvoidBinPacking = true;
964     State.Stack.back().BreakBeforeParameter = false;
965   }
966   if (Current.is(TT_CtorInitializerColon) &&
967       Style.BreakConstructorInitializers == FormatStyle::BCIS_AfterColon) {
968     State.Stack.back().Indent =
969         State.FirstIndent + Style.ConstructorInitializerIndentWidth;
970     State.Stack.back().NestedBlockIndent = State.Stack.back().Indent;
971     if (Style.ConstructorInitializerAllOnOneLineOrOnePerLine)
972       State.Stack.back().AvoidBinPacking = true;
973   }
974   if (Current.is(TT_InheritanceColon))
975     State.Stack.back().Indent =
976         State.FirstIndent + Style.ContinuationIndentWidth;
977   if (Current.isOneOf(TT_BinaryOperator, TT_ConditionalExpr) && Newline)
978     State.Stack.back().NestedBlockIndent =
979         State.Column + Current.ColumnWidth + 1;
980   if (Current.isOneOf(TT_LambdaLSquare, TT_LambdaArrow))
981     State.Stack.back().LastSpace = State.Column;
982 
983   // Insert scopes created by fake parenthesis.
984   const FormatToken *Previous = Current.getPreviousNonComment();
985 
986   // Add special behavior to support a format commonly used for JavaScript
987   // closures:
988   //   SomeFunction(function() {
989   //     foo();
990   //     bar();
991   //   }, a, b, c);
992   if (Current.isNot(tok::comment) && Previous &&
993       Previous->isOneOf(tok::l_brace, TT_ArrayInitializerLSquare) &&
994       !Previous->is(TT_DictLiteral) && State.Stack.size() > 1) {
995     if (State.Stack[State.Stack.size() - 2].NestedBlockInlined && Newline)
996       for (unsigned i = 0, e = State.Stack.size() - 1; i != e; ++i)
997         State.Stack[i].NoLineBreak = true;
998     State.Stack[State.Stack.size() - 2].NestedBlockInlined = false;
999   }
1000   if (Previous &&
1001       (Previous->isOneOf(tok::l_paren, tok::comma, tok::colon) ||
1002        Previous->isOneOf(TT_BinaryOperator, TT_ConditionalExpr)) &&
1003       !Previous->isOneOf(TT_DictLiteral, TT_ObjCMethodExpr)) {
1004     State.Stack.back().NestedBlockInlined =
1005         !Newline &&
1006         (Previous->isNot(tok::l_paren) || Previous->ParameterCount > 1);
1007   }
1008 
1009   moveStatePastFakeLParens(State, Newline);
1010   moveStatePastScopeCloser(State);
1011   bool AllowBreak = !State.Stack.back().NoLineBreak &&
1012                     !State.Stack.back().NoLineBreakInOperand;
1013   moveStatePastScopeOpener(State, Newline);
1014   moveStatePastFakeRParens(State);
1015 
1016   if (Current.is(TT_ObjCStringLiteral) && State.StartOfStringLiteral == 0)
1017     State.StartOfStringLiteral = State.Column + 1;
1018   else if (Current.isStringLiteral() && State.StartOfStringLiteral == 0)
1019     State.StartOfStringLiteral = State.Column;
1020   else if (!Current.isOneOf(tok::comment, tok::identifier, tok::hash) &&
1021            !Current.isStringLiteral())
1022     State.StartOfStringLiteral = 0;
1023 
1024   State.Column += Current.ColumnWidth;
1025   State.NextToken = State.NextToken->Next;
1026 
1027   unsigned Penalty =
1028       handleEndOfLine(Current, State, DryRun, AllowBreak);
1029 
1030   if (Current.Role)
1031     Current.Role->formatFromToken(State, this, DryRun);
1032   // If the previous has a special role, let it consume tokens as appropriate.
1033   // It is necessary to start at the previous token for the only implemented
1034   // role (comma separated list). That way, the decision whether or not to break
1035   // after the "{" is already done and both options are tried and evaluated.
1036   // FIXME: This is ugly, find a better way.
1037   if (Previous && Previous->Role)
1038     Penalty += Previous->Role->formatAfterToken(State, this, DryRun);
1039 
1040   return Penalty;
1041 }
1042 
1043 void ContinuationIndenter::moveStatePastFakeLParens(LineState &State,
1044                                                     bool Newline) {
1045   const FormatToken &Current = *State.NextToken;
1046   const FormatToken *Previous = Current.getPreviousNonComment();
1047 
1048   // Don't add extra indentation for the first fake parenthesis after
1049   // 'return', assignments or opening <({[. The indentation for these cases
1050   // is special cased.
1051   bool SkipFirstExtraIndent =
1052       (Previous && (Previous->opensScope() ||
1053                     Previous->isOneOf(tok::semi, tok::kw_return) ||
1054                     (Previous->getPrecedence() == prec::Assignment &&
1055                      Style.AlignOperands) ||
1056                     Previous->is(TT_ObjCMethodExpr)));
1057   for (SmallVectorImpl<prec::Level>::const_reverse_iterator
1058            I = Current.FakeLParens.rbegin(),
1059            E = Current.FakeLParens.rend();
1060        I != E; ++I) {
1061     ParenState NewParenState = State.Stack.back();
1062     NewParenState.ContainsLineBreak = false;
1063     NewParenState.LastOperatorWrapped = true;
1064     NewParenState.NoLineBreak =
1065         NewParenState.NoLineBreak || State.Stack.back().NoLineBreakInOperand;
1066 
1067     // Don't propagate AvoidBinPacking into subexpressions of arg/param lists.
1068     if (*I > prec::Comma)
1069       NewParenState.AvoidBinPacking = false;
1070 
1071     // Indent from 'LastSpace' unless these are fake parentheses encapsulating
1072     // a builder type call after 'return' or, if the alignment after opening
1073     // brackets is disabled.
1074     if (!Current.isTrailingComment() &&
1075         (Style.AlignOperands || *I < prec::Assignment) &&
1076         (!Previous || Previous->isNot(tok::kw_return) ||
1077          (Style.Language != FormatStyle::LK_Java && *I > 0)) &&
1078         (Style.AlignAfterOpenBracket != FormatStyle::BAS_DontAlign ||
1079          *I != prec::Comma || Current.NestingLevel == 0))
1080       NewParenState.Indent =
1081           std::max(std::max(State.Column, NewParenState.Indent),
1082                    State.Stack.back().LastSpace);
1083 
1084     // Do not indent relative to the fake parentheses inserted for "." or "->".
1085     // This is a special case to make the following to statements consistent:
1086     //   OuterFunction(InnerFunctionCall( // break
1087     //       ParameterToInnerFunction));
1088     //   OuterFunction(SomeObject.InnerFunctionCall( // break
1089     //       ParameterToInnerFunction));
1090     if (*I > prec::Unknown)
1091       NewParenState.LastSpace = std::max(NewParenState.LastSpace, State.Column);
1092     if (*I != prec::Conditional && !Current.is(TT_UnaryOperator) &&
1093         Style.AlignAfterOpenBracket != FormatStyle::BAS_DontAlign)
1094       NewParenState.StartOfFunctionCall = State.Column;
1095 
1096     // Always indent conditional expressions. Never indent expression where
1097     // the 'operator' is ',', ';' or an assignment (i.e. *I <=
1098     // prec::Assignment) as those have different indentation rules. Indent
1099     // other expression, unless the indentation needs to be skipped.
1100     if (*I == prec::Conditional ||
1101         (!SkipFirstExtraIndent && *I > prec::Assignment &&
1102          !Current.isTrailingComment()))
1103       NewParenState.Indent += Style.ContinuationIndentWidth;
1104     if ((Previous && !Previous->opensScope()) || *I != prec::Comma)
1105       NewParenState.BreakBeforeParameter = false;
1106     State.Stack.push_back(NewParenState);
1107     SkipFirstExtraIndent = false;
1108   }
1109 }
1110 
1111 void ContinuationIndenter::moveStatePastFakeRParens(LineState &State) {
1112   for (unsigned i = 0, e = State.NextToken->FakeRParens; i != e; ++i) {
1113     unsigned VariablePos = State.Stack.back().VariablePos;
1114     if (State.Stack.size() == 1) {
1115       // Do not pop the last element.
1116       break;
1117     }
1118     State.Stack.pop_back();
1119     State.Stack.back().VariablePos = VariablePos;
1120   }
1121 }
1122 
1123 void ContinuationIndenter::moveStatePastScopeOpener(LineState &State,
1124                                                     bool Newline) {
1125   const FormatToken &Current = *State.NextToken;
1126   if (!Current.opensScope())
1127     return;
1128 
1129   if (Current.MatchingParen && Current.BlockKind == BK_Block) {
1130     moveStateToNewBlock(State);
1131     return;
1132   }
1133 
1134   unsigned NewIndent;
1135   unsigned LastSpace = State.Stack.back().LastSpace;
1136   bool AvoidBinPacking;
1137   bool BreakBeforeParameter = false;
1138   unsigned NestedBlockIndent = std::max(State.Stack.back().StartOfFunctionCall,
1139                                         State.Stack.back().NestedBlockIndent);
1140   if (Current.isOneOf(tok::l_brace, TT_ArrayInitializerLSquare) ||
1141       opensProtoMessageField(Current, Style)) {
1142     if (Current.opensBlockOrBlockTypeList(Style)) {
1143       NewIndent = Style.IndentWidth +
1144                   std::min(State.Column, State.Stack.back().NestedBlockIndent);
1145     } else {
1146       NewIndent = State.Stack.back().LastSpace + Style.ContinuationIndentWidth;
1147     }
1148     const FormatToken *NextNoComment = Current.getNextNonComment();
1149     bool EndsInComma = Current.MatchingParen &&
1150                        Current.MatchingParen->Previous &&
1151                        Current.MatchingParen->Previous->is(tok::comma);
1152     AvoidBinPacking = EndsInComma || Current.is(TT_DictLiteral) ||
1153                       Style.Language == FormatStyle::LK_Proto ||
1154                       Style.Language == FormatStyle::LK_TextProto ||
1155                       !Style.BinPackArguments ||
1156                       (NextNoComment &&
1157                        NextNoComment->isOneOf(TT_DesignatedInitializerPeriod,
1158                                               TT_DesignatedInitializerLSquare));
1159     BreakBeforeParameter = EndsInComma;
1160     if (Current.ParameterCount > 1)
1161       NestedBlockIndent = std::max(NestedBlockIndent, State.Column + 1);
1162   } else {
1163     NewIndent = Style.ContinuationIndentWidth +
1164                 std::max(State.Stack.back().LastSpace,
1165                          State.Stack.back().StartOfFunctionCall);
1166 
1167     // Ensure that different different brackets force relative alignment, e.g.:
1168     // void SomeFunction(vector<  // break
1169     //                       int> v);
1170     // FIXME: We likely want to do this for more combinations of brackets.
1171     // Verify that it is wanted for ObjC, too.
1172     if (Current.is(tok::less) && Current.ParentBracket == tok::l_paren) {
1173       NewIndent = std::max(NewIndent, State.Stack.back().Indent);
1174       LastSpace = std::max(LastSpace, State.Stack.back().Indent);
1175     }
1176 
1177     bool EndsInComma =
1178         Current.MatchingParen &&
1179         Current.MatchingParen->getPreviousNonComment() &&
1180         Current.MatchingParen->getPreviousNonComment()->is(tok::comma);
1181 
1182     AvoidBinPacking =
1183         (Style.Language == FormatStyle::LK_JavaScript && EndsInComma) ||
1184         (State.Line->MustBeDeclaration && !Style.BinPackParameters) ||
1185         (!State.Line->MustBeDeclaration && !Style.BinPackArguments) ||
1186         (Style.ExperimentalAutoDetectBinPacking &&
1187          (Current.PackingKind == PPK_OnePerLine ||
1188           (!BinPackInconclusiveFunctions &&
1189            Current.PackingKind == PPK_Inconclusive)));
1190 
1191     if (Current.is(TT_ObjCMethodExpr) && Current.MatchingParen) {
1192       if (Style.ColumnLimit) {
1193         // If this '[' opens an ObjC call, determine whether all parameters fit
1194         // into one line and put one per line if they don't.
1195         if (getLengthToMatchingParen(Current) + State.Column >
1196             getColumnLimit(State))
1197           BreakBeforeParameter = true;
1198       } else {
1199         // For ColumnLimit = 0, we have to figure out whether there is or has to
1200         // be a line break within this call.
1201         for (const FormatToken *Tok = &Current;
1202              Tok && Tok != Current.MatchingParen; Tok = Tok->Next) {
1203           if (Tok->MustBreakBefore ||
1204               (Tok->CanBreakBefore && Tok->NewlinesBefore > 0)) {
1205             BreakBeforeParameter = true;
1206             break;
1207           }
1208         }
1209       }
1210     }
1211 
1212     if (Style.Language == FormatStyle::LK_JavaScript && EndsInComma)
1213       BreakBeforeParameter = true;
1214   }
1215   // Generally inherit NoLineBreak from the current scope to nested scope.
1216   // However, don't do this for non-empty nested blocks, dict literals and
1217   // array literals as these follow different indentation rules.
1218   bool NoLineBreak =
1219       Current.Children.empty() &&
1220       !Current.isOneOf(TT_DictLiteral, TT_ArrayInitializerLSquare) &&
1221       (State.Stack.back().NoLineBreak ||
1222        State.Stack.back().NoLineBreakInOperand ||
1223        (Current.is(TT_TemplateOpener) &&
1224         State.Stack.back().ContainsUnwrappedBuilder));
1225   State.Stack.push_back(
1226       ParenState(NewIndent, LastSpace, AvoidBinPacking, NoLineBreak));
1227   State.Stack.back().NestedBlockIndent = NestedBlockIndent;
1228   State.Stack.back().BreakBeforeParameter = BreakBeforeParameter;
1229   State.Stack.back().HasMultipleNestedBlocks = Current.BlockParameterCount > 1;
1230 }
1231 
1232 void ContinuationIndenter::moveStatePastScopeCloser(LineState &State) {
1233   const FormatToken &Current = *State.NextToken;
1234   if (!Current.closesScope())
1235     return;
1236 
1237   // If we encounter a closing ), ], } or >, we can remove a level from our
1238   // stacks.
1239   if (State.Stack.size() > 1 &&
1240       (Current.isOneOf(tok::r_paren, tok::r_square, TT_TemplateString) ||
1241        (Current.is(tok::r_brace) && State.NextToken != State.Line->First) ||
1242        State.NextToken->is(TT_TemplateCloser)))
1243     State.Stack.pop_back();
1244 
1245   if (Current.is(tok::r_square)) {
1246     // If this ends the array subscript expr, reset the corresponding value.
1247     const FormatToken *NextNonComment = Current.getNextNonComment();
1248     if (NextNonComment && NextNonComment->isNot(tok::l_square))
1249       State.Stack.back().StartOfArraySubscripts = 0;
1250   }
1251 }
1252 
1253 void ContinuationIndenter::moveStateToNewBlock(LineState &State) {
1254   unsigned NestedBlockIndent = State.Stack.back().NestedBlockIndent;
1255   // ObjC block sometimes follow special indentation rules.
1256   unsigned NewIndent =
1257       NestedBlockIndent + (State.NextToken->is(TT_ObjCBlockLBrace)
1258                                ? Style.ObjCBlockIndentWidth
1259                                : Style.IndentWidth);
1260   State.Stack.push_back(ParenState(NewIndent, State.Stack.back().LastSpace,
1261                                    /*AvoidBinPacking=*/true,
1262                                    /*NoLineBreak=*/false));
1263   State.Stack.back().NestedBlockIndent = NestedBlockIndent;
1264   State.Stack.back().BreakBeforeParameter = true;
1265 }
1266 
1267 static unsigned getLastLineEndColumn(StringRef Text, unsigned StartColumn,
1268                                      unsigned TabWidth,
1269                                      encoding::Encoding Encoding) {
1270   size_t LastNewlinePos = Text.find_last_of("\n");
1271   if (LastNewlinePos == StringRef::npos) {
1272     return StartColumn +
1273            encoding::columnWidthWithTabs(Text, StartColumn, TabWidth, Encoding);
1274   } else {
1275     return encoding::columnWidthWithTabs(Text.substr(LastNewlinePos),
1276                                          /*StartColumn=*/0, TabWidth, Encoding);
1277   }
1278 }
1279 
1280 unsigned ContinuationIndenter::reformatRawStringLiteral(
1281     const FormatToken &Current, LineState &State,
1282     const FormatStyle &RawStringStyle, bool DryRun) {
1283   unsigned StartColumn = State.Column - Current.ColumnWidth;
1284   auto Delimiter = *getRawStringDelimiter(Current.TokenText);
1285   // The text of a raw string is between the leading 'R"delimiter(' and the
1286   // trailing 'delimiter)"'.
1287   unsigned PrefixSize = 3 + Delimiter.size();
1288   unsigned SuffixSize = 2 + Delimiter.size();
1289 
1290   // The first start column is the column the raw text starts.
1291   unsigned FirstStartColumn = StartColumn + PrefixSize;
1292 
1293   // The next start column is the intended indentation a line break inside
1294   // the raw string at level 0. It is determined by the following rules:
1295   //   - if the content starts on newline, it is one level more than the current
1296   //     indent, and
1297   //   - if the content does not start on a newline, it is the first start
1298   //     column.
1299   // These rules have the advantage that the formatted content both does not
1300   // violate the rectangle rule and visually flows within the surrounding
1301   // source.
1302   bool ContentStartsOnNewline = Current.TokenText[PrefixSize] == '\n';
1303   unsigned NextStartColumn = ContentStartsOnNewline
1304                                  ? State.Stack.back().Indent + Style.IndentWidth
1305                                  : FirstStartColumn;
1306 
1307   // The last start column is the column the raw string suffix starts if it is
1308   // put on a newline.
1309   // The last start column is the intended indentation of the raw string postfix
1310   // if it is put on a newline. It is determined by the following rules:
1311   //   - if the raw string prefix starts on a newline, it is the column where
1312   //     that raw string prefix starts, and
1313   //   - if the raw string prefix does not start on a newline, it is the current
1314   //     indent.
1315   unsigned LastStartColumn = Current.NewlinesBefore
1316                                  ? FirstStartColumn - PrefixSize
1317                                  : State.Stack.back().Indent;
1318 
1319   std::string RawText =
1320       Current.TokenText.substr(PrefixSize).drop_back(SuffixSize);
1321 
1322   std::pair<tooling::Replacements, unsigned> Fixes = internal::reformat(
1323       RawStringStyle, RawText, {tooling::Range(0, RawText.size())},
1324       FirstStartColumn, NextStartColumn, LastStartColumn, "<stdin>",
1325       /*Status=*/nullptr);
1326 
1327   auto NewCode = applyAllReplacements(RawText, Fixes.first);
1328   tooling::Replacements NoFixes;
1329   if (!NewCode) {
1330     State.Column += Current.ColumnWidth;
1331     return 0;
1332   }
1333   if (!DryRun) {
1334     SourceLocation OriginLoc =
1335         Current.Tok.getLocation().getLocWithOffset(PrefixSize);
1336     for (const tooling::Replacement &Fix : Fixes.first) {
1337       auto Err = Whitespaces.addReplacement(tooling::Replacement(
1338           SourceMgr, OriginLoc.getLocWithOffset(Fix.getOffset()),
1339           Fix.getLength(), Fix.getReplacementText()));
1340       if (Err) {
1341         llvm::errs() << "Failed to reformat raw string: "
1342                      << llvm::toString(std::move(Err)) << "\n";
1343       }
1344     }
1345   }
1346   unsigned RawLastLineEndColumn = getLastLineEndColumn(
1347       *NewCode, FirstStartColumn, Style.TabWidth, Encoding);
1348   State.Column = RawLastLineEndColumn + SuffixSize;
1349   return Fixes.second;
1350 }
1351 
1352 unsigned ContinuationIndenter::addMultilineToken(const FormatToken &Current,
1353                                                  LineState &State) {
1354   // Break before further function parameters on all levels.
1355   for (unsigned i = 0, e = State.Stack.size(); i != e; ++i)
1356     State.Stack[i].BreakBeforeParameter = true;
1357 
1358   unsigned ColumnsUsed = State.Column;
1359   // We can only affect layout of the first and the last line, so the penalty
1360   // for all other lines is constant, and we ignore it.
1361   State.Column = Current.LastLineColumnWidth;
1362 
1363   if (ColumnsUsed > getColumnLimit(State))
1364     return Style.PenaltyExcessCharacter * (ColumnsUsed - getColumnLimit(State));
1365   return 0;
1366 }
1367 
1368 unsigned ContinuationIndenter::handleEndOfLine(const FormatToken &Current,
1369                                                LineState &State, bool DryRun,
1370                                                bool AllowBreak) {
1371   unsigned Penalty = 0;
1372   // Compute the raw string style to use in case this is a raw string literal
1373   // that can be reformatted.
1374   auto RawStringStyle = getRawStringStyle(Current, State);
1375   if (RawStringStyle) {
1376     Penalty = reformatRawStringLiteral(Current, State, *RawStringStyle, DryRun);
1377   } else if (Current.IsMultiline && Current.isNot(TT_BlockComment)) {
1378     // Don't break multi-line tokens other than block comments and raw string
1379     // literals. Instead, just update the state.
1380     Penalty = addMultilineToken(Current, State);
1381   } else if (State.Line->Type != LT_ImportStatement) {
1382     // We generally don't break import statements.
1383     Penalty = breakProtrudingToken(Current, State, AllowBreak, DryRun);
1384   }
1385   if (State.Column > getColumnLimit(State)) {
1386     unsigned ExcessCharacters = State.Column - getColumnLimit(State);
1387     Penalty += Style.PenaltyExcessCharacter * ExcessCharacters;
1388   }
1389   return Penalty;
1390 }
1391 
1392 llvm::Optional<FormatStyle>
1393 ContinuationIndenter::getRawStringStyle(const FormatToken &Current,
1394                                         const LineState &State) {
1395   if (!Current.isStringLiteral())
1396     return None;
1397   auto Delimiter = getRawStringDelimiter(Current.TokenText);
1398   if (!Delimiter)
1399     return None;
1400   auto RawStringStyle = RawStringFormats.get(*Delimiter);
1401   if (!RawStringStyle)
1402     return None;
1403   RawStringStyle->ColumnLimit = getColumnLimit(State);
1404   return RawStringStyle;
1405 }
1406 
1407 std::unique_ptr<BreakableToken> ContinuationIndenter::createBreakableToken(
1408     const FormatToken &Current, LineState &State, bool AllowBreak) {
1409   unsigned StartColumn = State.Column - Current.ColumnWidth;
1410   if (Current.isStringLiteral()) {
1411     // FIXME: String literal breaking is currently disabled for Java and JS, as
1412     // it requires strings to be merged using "+" which we don't support.
1413     if (Style.Language == FormatStyle::LK_Java ||
1414         Style.Language == FormatStyle::LK_JavaScript ||
1415         !Style.BreakStringLiterals ||
1416         !AllowBreak)
1417       return nullptr;
1418 
1419     // Don't break string literals inside preprocessor directives (except for
1420     // #define directives, as their contents are stored in separate lines and
1421     // are not affected by this check).
1422     // This way we avoid breaking code with line directives and unknown
1423     // preprocessor directives that contain long string literals.
1424     if (State.Line->Type == LT_PreprocessorDirective)
1425       return nullptr;
1426     // Exempts unterminated string literals from line breaking. The user will
1427     // likely want to terminate the string before any line breaking is done.
1428     if (Current.IsUnterminatedLiteral)
1429       return nullptr;
1430 
1431     StringRef Text = Current.TokenText;
1432     StringRef Prefix;
1433     StringRef Postfix;
1434     // FIXME: Handle whitespace between '_T', '(', '"..."', and ')'.
1435     // FIXME: Store Prefix and Suffix (or PrefixLength and SuffixLength to
1436     // reduce the overhead) for each FormatToken, which is a string, so that we
1437     // don't run multiple checks here on the hot path.
1438     if ((Text.endswith(Postfix = "\"") &&
1439          (Text.startswith(Prefix = "@\"") || Text.startswith(Prefix = "\"") ||
1440           Text.startswith(Prefix = "u\"") || Text.startswith(Prefix = "U\"") ||
1441           Text.startswith(Prefix = "u8\"") ||
1442           Text.startswith(Prefix = "L\""))) ||
1443         (Text.startswith(Prefix = "_T(\"") && Text.endswith(Postfix = "\")"))) {
1444       return llvm::make_unique<BreakableStringLiteral>(
1445           Current, StartColumn, Prefix, Postfix, State.Line->InPPDirective,
1446           Encoding, Style);
1447     }
1448   } else if (Current.is(TT_BlockComment)) {
1449     if (!Style.ReflowComments ||
1450         // If a comment token switches formatting, like
1451         // /* clang-format on */, we don't want to break it further,
1452         // but we may still want to adjust its indentation.
1453         switchesFormatting(Current)) {
1454       return nullptr;
1455     }
1456     return llvm::make_unique<BreakableBlockComment>(
1457         Current, StartColumn, Current.OriginalColumn, !Current.Previous,
1458         State.Line->InPPDirective, Encoding, Style);
1459   } else if (Current.is(TT_LineComment) &&
1460              (Current.Previous == nullptr ||
1461               Current.Previous->isNot(TT_ImplicitStringLiteral))) {
1462     if (!Style.ReflowComments ||
1463         CommentPragmasRegex.match(Current.TokenText.substr(2)) ||
1464         switchesFormatting(Current))
1465       return nullptr;
1466     return llvm::make_unique<BreakableLineCommentSection>(
1467         Current, StartColumn, Current.OriginalColumn, !Current.Previous,
1468         /*InPPDirective=*/false, Encoding, Style);
1469   }
1470   return nullptr;
1471 }
1472 
1473 unsigned ContinuationIndenter::breakProtrudingToken(const FormatToken &Current,
1474                                                     LineState &State,
1475                                                     bool AllowBreak,
1476                                                     bool DryRun) {
1477   std::unique_ptr<BreakableToken> Token =
1478       createBreakableToken(Current, State, AllowBreak);
1479   if (!Token)
1480     return 0;
1481   unsigned ColumnLimit = getColumnLimit(State);
1482   unsigned StartColumn = State.Column - Current.ColumnWidth;
1483   if (Current.is(TT_LineComment)) {
1484     // We don't insert backslashes when breaking line comments.
1485     ColumnLimit = Style.ColumnLimit;
1486   }
1487   if (Current.UnbreakableTailLength >= ColumnLimit)
1488     return 0;
1489 
1490   unsigned RemainingSpace = ColumnLimit - Current.UnbreakableTailLength;
1491   bool BreakInserted = false;
1492   // We use a conservative reflowing strategy. Reflow starts after a line is
1493   // broken or the corresponding whitespace compressed. Reflow ends as soon as a
1494   // line that doesn't get reflown with the previous line is reached.
1495   bool ReflowInProgress = false;
1496   unsigned Penalty = 0;
1497   unsigned RemainingTokenColumns = 0;
1498   unsigned TailOffset = 0;
1499   for (unsigned LineIndex = 0, EndIndex = Token->getLineCount();
1500        LineIndex != EndIndex; ++LineIndex) {
1501     BreakableToken::Split SplitBefore(StringRef::npos, 0);
1502     if (ReflowInProgress) {
1503       SplitBefore = Token->getSplitBefore(LineIndex, RemainingTokenColumns,
1504                                           RemainingSpace, CommentPragmasRegex);
1505     }
1506     ReflowInProgress = SplitBefore.first != StringRef::npos;
1507     TailOffset =
1508         ReflowInProgress ? (SplitBefore.first + SplitBefore.second) : 0;
1509     BreakInserted = BreakInserted || Token->introducesBreakBefore(LineIndex);
1510     if (!DryRun)
1511       Token->replaceWhitespaceBefore(LineIndex, RemainingTokenColumns,
1512                                      RemainingSpace, SplitBefore, Whitespaces);
1513     RemainingTokenColumns = Token->getLineLengthAfterSplitBefore(
1514         LineIndex, TailOffset, RemainingTokenColumns, ColumnLimit, SplitBefore);
1515     while (RemainingTokenColumns > RemainingSpace) {
1516       BreakableToken::Split Split = Token->getSplit(
1517           LineIndex, TailOffset, ColumnLimit, CommentPragmasRegex);
1518       if (Split.first == StringRef::npos) {
1519         // The last line's penalty is handled in addNextStateToQueue().
1520         if (LineIndex < EndIndex - 1)
1521           Penalty += Style.PenaltyExcessCharacter *
1522                      (RemainingTokenColumns - RemainingSpace);
1523         break;
1524       }
1525       assert(Split.first != 0);
1526 
1527       // Check if compressing the whitespace range will bring the line length
1528       // under the limit. If that is the case, we perform whitespace compression
1529       // instead of inserting a line break.
1530       unsigned RemainingTokenColumnsAfterCompression =
1531           Token->getLineLengthAfterCompression(RemainingTokenColumns, Split);
1532       if (RemainingTokenColumnsAfterCompression <= RemainingSpace) {
1533         RemainingTokenColumns = RemainingTokenColumnsAfterCompression;
1534         ReflowInProgress = true;
1535         if (!DryRun)
1536           Token->compressWhitespace(LineIndex, TailOffset, Split, Whitespaces);
1537         break;
1538       }
1539 
1540       unsigned NewRemainingTokenColumns = Token->getLineLengthAfterSplit(
1541           LineIndex, TailOffset + Split.first + Split.second, StringRef::npos);
1542 
1543       // When breaking before a tab character, it may be moved by a few columns,
1544       // but will still be expanded to the next tab stop, so we don't save any
1545       // columns.
1546       if (NewRemainingTokenColumns == RemainingTokenColumns)
1547         break;
1548 
1549       assert(NewRemainingTokenColumns < RemainingTokenColumns);
1550       if (!DryRun)
1551         Token->insertBreak(LineIndex, TailOffset, Split, Whitespaces);
1552       Penalty += Current.SplitPenalty;
1553       unsigned ColumnsUsed =
1554           Token->getLineLengthAfterSplit(LineIndex, TailOffset, Split.first);
1555       if (ColumnsUsed > ColumnLimit) {
1556         Penalty += Style.PenaltyExcessCharacter * (ColumnsUsed - ColumnLimit);
1557       }
1558       TailOffset += Split.first + Split.second;
1559       RemainingTokenColumns = NewRemainingTokenColumns;
1560       ReflowInProgress = true;
1561       BreakInserted = true;
1562     }
1563   }
1564 
1565   BreakableToken::Split SplitAfterLastLine =
1566       Token->getSplitAfterLastLine(TailOffset, ColumnLimit);
1567   if (SplitAfterLastLine.first != StringRef::npos) {
1568     if (!DryRun)
1569       Token->replaceWhitespaceAfterLastLine(TailOffset, SplitAfterLastLine,
1570                                             Whitespaces);
1571     RemainingTokenColumns = Token->getLineLengthAfterSplitAfterLastLine(
1572         TailOffset, SplitAfterLastLine);
1573   }
1574 
1575   State.Column = RemainingTokenColumns;
1576 
1577   if (BreakInserted) {
1578     // If we break the token inside a parameter list, we need to break before
1579     // the next parameter on all levels, so that the next parameter is clearly
1580     // visible. Line comments already introduce a break.
1581     if (Current.isNot(TT_LineComment)) {
1582       for (unsigned i = 0, e = State.Stack.size(); i != e; ++i)
1583         State.Stack[i].BreakBeforeParameter = true;
1584     }
1585 
1586     if (Current.is(TT_BlockComment))
1587       State.NoContinuation = true;
1588 
1589     Penalty += Current.isStringLiteral() ? Style.PenaltyBreakString
1590                                          : Style.PenaltyBreakComment;
1591 
1592     State.Stack.back().LastSpace = StartColumn;
1593   }
1594 
1595   Token->updateNextToken(State);
1596 
1597   return Penalty;
1598 }
1599 
1600 unsigned ContinuationIndenter::getColumnLimit(const LineState &State) const {
1601   // In preprocessor directives reserve two chars for trailing " \"
1602   return Style.ColumnLimit - (State.Line->InPPDirective ? 2 : 0);
1603 }
1604 
1605 bool ContinuationIndenter::nextIsMultilineString(const LineState &State) {
1606   const FormatToken &Current = *State.NextToken;
1607   if (!Current.isStringLiteral() || Current.is(TT_ImplicitStringLiteral))
1608     return false;
1609   // We never consider raw string literals "multiline" for the purpose of
1610   // AlwaysBreakBeforeMultilineStrings implementation as they are special-cased
1611   // (see TokenAnnotator::mustBreakBefore().
1612   if (Current.TokenText.startswith("R\""))
1613     return false;
1614   if (Current.IsMultiline)
1615     return true;
1616   if (Current.getNextNonComment() &&
1617       Current.getNextNonComment()->isStringLiteral())
1618     return true; // Implicit concatenation.
1619   if (Style.ColumnLimit != 0 &&
1620       State.Column + Current.ColumnWidth + Current.UnbreakableTailLength >
1621           Style.ColumnLimit)
1622     return true; // String will be split.
1623   return false;
1624 }
1625 
1626 } // namespace format
1627 } // namespace clang
1628