1 //===--- ContinuationIndenter.cpp - Format C++ code -----------------------===//
2 //
3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4 // See https://llvm.org/LICENSE.txt for license information.
5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6 //
7 //===----------------------------------------------------------------------===//
8 ///
9 /// \file
10 /// This file implements the continuation indenter.
11 ///
12 //===----------------------------------------------------------------------===//
13 
14 #include "ContinuationIndenter.h"
15 #include "BreakableToken.h"
16 #include "FormatInternal.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 
23 #define DEBUG_TYPE "format-indenter"
24 
25 namespace clang {
26 namespace format {
27 
28 // Returns true if a TT_SelectorName should be indented when wrapped,
29 // false otherwise.
30 static bool shouldIndentWrappedSelectorName(const FormatStyle &Style,
31                                             LineType LineType) {
32   return Style.IndentWrappedFunctionNames || LineType == LT_ObjCMethodDecl;
33 }
34 
35 // Returns the length of everything up to the first possible line break after
36 // the ), ], } or > matching \c Tok.
37 static unsigned getLengthToMatchingParen(const FormatToken &Tok,
38                                          const std::vector<ParenState> &Stack) {
39   // Normally whether or not a break before T is possible is calculated and
40   // stored in T.CanBreakBefore. Braces, array initializers and text proto
41   // messages like `key: < ... >` are an exception: a break is possible
42   // before a closing brace R if a break was inserted after the corresponding
43   // opening brace. The information about whether or not a break is needed
44   // before a closing brace R is stored in the ParenState field
45   // S.BreakBeforeClosingBrace where S is the state that R closes.
46   //
47   // In order to decide whether there can be a break before encountered right
48   // braces, this implementation iterates over the sequence of tokens and over
49   // the paren stack in lockstep, keeping track of the stack level which visited
50   // right braces correspond to in MatchingStackIndex.
51   //
52   // For example, consider:
53   // L. <- line number
54   // 1. {
55   // 2. {1},
56   // 3. {2},
57   // 4. {{3}}}
58   //     ^ where we call this method with this token.
59   // The paren stack at this point contains 3 brace levels:
60   //  0. { at line 1, BreakBeforeClosingBrace: true
61   //  1. first { at line 4, BreakBeforeClosingBrace: false
62   //  2. second { at line 4, BreakBeforeClosingBrace: false,
63   //  where there might be fake parens levels in-between these levels.
64   // The algorithm will start at the first } on line 4, which is the matching
65   // brace of the initial left brace and at level 2 of the stack. Then,
66   // examining BreakBeforeClosingBrace: false at level 2, it will continue to
67   // the second } on line 4, and will traverse the stack downwards until it
68   // finds the matching { on level 1. Then, examining BreakBeforeClosingBrace:
69   // false at level 1, it will continue to the third } on line 4 and will
70   // traverse the stack downwards until it finds the matching { on level 0.
71   // Then, examining BreakBeforeClosingBrace: true at level 0, the algorithm
72   // will stop and will use the second } on line 4 to determine the length to
73   // return, as in this example the range will include the tokens: {3}}
74   //
75   // The algorithm will only traverse the stack if it encounters braces, array
76   // initializer squares or text proto angle brackets.
77   if (!Tok.MatchingParen)
78     return 0;
79   FormatToken *End = Tok.MatchingParen;
80   // Maintains a stack level corresponding to the current End token.
81   int MatchingStackIndex = Stack.size() - 1;
82   // Traverses the stack downwards, looking for the level to which LBrace
83   // corresponds. Returns either a pointer to the matching level or nullptr if
84   // LParen is not found in the initial portion of the stack up to
85   // MatchingStackIndex.
86   auto FindParenState = [&](const FormatToken *LBrace) -> const ParenState * {
87     while (MatchingStackIndex >= 0 && Stack[MatchingStackIndex].Tok != LBrace)
88       --MatchingStackIndex;
89     return MatchingStackIndex >= 0 ? &Stack[MatchingStackIndex] : nullptr;
90   };
91   for (; End->Next; End = End->Next) {
92     if (End->Next->CanBreakBefore)
93       break;
94     if (!End->Next->closesScope())
95       continue;
96     if (End->Next->MatchingParen &&
97         End->Next->MatchingParen->isOneOf(
98             tok::l_brace, TT_ArrayInitializerLSquare, tok::less)) {
99       const ParenState *State = FindParenState(End->Next->MatchingParen);
100       if (State && State->BreakBeforeClosingBrace)
101         break;
102     }
103   }
104   return End->TotalLength - Tok.TotalLength + 1;
105 }
106 
107 static unsigned getLengthToNextOperator(const FormatToken &Tok) {
108   if (!Tok.NextOperator)
109     return 0;
110   return Tok.NextOperator->TotalLength - Tok.TotalLength;
111 }
112 
113 // Returns \c true if \c Tok is the "." or "->" of a call and starts the next
114 // segment of a builder type call.
115 static bool startsSegmentOfBuilderTypeCall(const FormatToken &Tok) {
116   return Tok.isMemberAccess() && Tok.Previous && Tok.Previous->closesScope();
117 }
118 
119 // Returns \c true if \c Current starts a new parameter.
120 static bool startsNextParameter(const FormatToken &Current,
121                                 const FormatStyle &Style) {
122   const FormatToken &Previous = *Current.Previous;
123   if (Current.is(TT_CtorInitializerComma) &&
124       Style.BreakConstructorInitializers == FormatStyle::BCIS_BeforeComma)
125     return true;
126   if (Style.Language == FormatStyle::LK_Proto && Current.is(TT_SelectorName))
127     return true;
128   return Previous.is(tok::comma) && !Current.isTrailingComment() &&
129          ((Previous.isNot(TT_CtorInitializerComma) ||
130            Style.BreakConstructorInitializers !=
131                FormatStyle::BCIS_BeforeComma) &&
132           (Previous.isNot(TT_InheritanceComma) ||
133            Style.BreakInheritanceList != FormatStyle::BILS_BeforeComma));
134 }
135 
136 static bool opensProtoMessageField(const FormatToken &LessTok,
137                                    const FormatStyle &Style) {
138   if (LessTok.isNot(tok::less))
139     return false;
140   return Style.Language == FormatStyle::LK_TextProto ||
141          (Style.Language == FormatStyle::LK_Proto &&
142           (LessTok.NestingLevel > 0 ||
143            (LessTok.Previous && LessTok.Previous->is(tok::equal))));
144 }
145 
146 // Returns the delimiter of a raw string literal, or None if TokenText is not
147 // the text of a raw string literal. The delimiter could be the empty string.
148 // For example, the delimiter of R"deli(cont)deli" is deli.
149 static llvm::Optional<StringRef> getRawStringDelimiter(StringRef TokenText) {
150   if (TokenText.size() < 5 // The smallest raw string possible is 'R"()"'.
151       || !TokenText.startswith("R\"") || !TokenText.endswith("\""))
152     return None;
153 
154   // A raw string starts with 'R"<delimiter>(' and delimiter is ascii and has
155   // size at most 16 by the standard, so the first '(' must be among the first
156   // 19 bytes.
157   size_t LParenPos = TokenText.substr(0, 19).find_first_of('(');
158   if (LParenPos == StringRef::npos)
159     return None;
160   StringRef Delimiter = TokenText.substr(2, LParenPos - 2);
161 
162   // Check that the string ends in ')Delimiter"'.
163   size_t RParenPos = TokenText.size() - Delimiter.size() - 2;
164   if (TokenText[RParenPos] != ')')
165     return None;
166   if (!TokenText.substr(RParenPos + 1).startswith(Delimiter))
167     return None;
168   return Delimiter;
169 }
170 
171 // Returns the canonical delimiter for \p Language, or the empty string if no
172 // canonical delimiter is specified.
173 static StringRef
174 getCanonicalRawStringDelimiter(const FormatStyle &Style,
175                                FormatStyle::LanguageKind Language) {
176   for (const auto &Format : Style.RawStringFormats) {
177     if (Format.Language == Language)
178       return StringRef(Format.CanonicalDelimiter);
179   }
180   return "";
181 }
182 
183 RawStringFormatStyleManager::RawStringFormatStyleManager(
184     const FormatStyle &CodeStyle) {
185   for (const auto &RawStringFormat : CodeStyle.RawStringFormats) {
186     llvm::Optional<FormatStyle> LanguageStyle =
187         CodeStyle.GetLanguageStyle(RawStringFormat.Language);
188     if (!LanguageStyle) {
189       FormatStyle PredefinedStyle;
190       if (!getPredefinedStyle(RawStringFormat.BasedOnStyle,
191                               RawStringFormat.Language, &PredefinedStyle)) {
192         PredefinedStyle = getLLVMStyle();
193         PredefinedStyle.Language = RawStringFormat.Language;
194       }
195       LanguageStyle = PredefinedStyle;
196     }
197     LanguageStyle->ColumnLimit = CodeStyle.ColumnLimit;
198     for (StringRef Delimiter : RawStringFormat.Delimiters) {
199       DelimiterStyle.insert({Delimiter, *LanguageStyle});
200     }
201     for (StringRef EnclosingFunction : RawStringFormat.EnclosingFunctions) {
202       EnclosingFunctionStyle.insert({EnclosingFunction, *LanguageStyle});
203     }
204   }
205 }
206 
207 llvm::Optional<FormatStyle>
208 RawStringFormatStyleManager::getDelimiterStyle(StringRef Delimiter) const {
209   auto It = DelimiterStyle.find(Delimiter);
210   if (It == DelimiterStyle.end())
211     return None;
212   return It->second;
213 }
214 
215 llvm::Optional<FormatStyle>
216 RawStringFormatStyleManager::getEnclosingFunctionStyle(
217     StringRef EnclosingFunction) const {
218   auto It = EnclosingFunctionStyle.find(EnclosingFunction);
219   if (It == EnclosingFunctionStyle.end())
220     return None;
221   return It->second;
222 }
223 
224 ContinuationIndenter::ContinuationIndenter(const FormatStyle &Style,
225                                            const AdditionalKeywords &Keywords,
226                                            const SourceManager &SourceMgr,
227                                            WhitespaceManager &Whitespaces,
228                                            encoding::Encoding Encoding,
229                                            bool BinPackInconclusiveFunctions)
230     : Style(Style), Keywords(Keywords), SourceMgr(SourceMgr),
231       Whitespaces(Whitespaces), Encoding(Encoding),
232       BinPackInconclusiveFunctions(BinPackInconclusiveFunctions),
233       CommentPragmasRegex(Style.CommentPragmas), RawStringFormats(Style) {}
234 
235 LineState ContinuationIndenter::getInitialState(unsigned FirstIndent,
236                                                 unsigned FirstStartColumn,
237                                                 const AnnotatedLine *Line,
238                                                 bool DryRun) {
239   LineState State;
240   State.FirstIndent = FirstIndent;
241   if (FirstStartColumn && Line->First->NewlinesBefore == 0)
242     State.Column = FirstStartColumn;
243   else
244     State.Column = FirstIndent;
245   // With preprocessor directive indentation, the line starts on column 0
246   // since it's indented after the hash, but FirstIndent is set to the
247   // preprocessor indent.
248   if (Style.IndentPPDirectives == FormatStyle::PPDIS_AfterHash &&
249       (Line->Type == LT_PreprocessorDirective ||
250        Line->Type == LT_ImportStatement))
251     State.Column = 0;
252   State.Line = Line;
253   State.NextToken = Line->First;
254   State.Stack.push_back(ParenState(/*Tok=*/nullptr, FirstIndent, FirstIndent,
255                                    /*AvoidBinPacking=*/false,
256                                    /*NoLineBreak=*/false));
257   State.LineContainsContinuedForLoopSection = false;
258   State.NoContinuation = false;
259   State.StartOfStringLiteral = 0;
260   State.StartOfLineLevel = 0;
261   State.LowestLevelOnLine = 0;
262   State.IgnoreStackForComparison = false;
263 
264   if (Style.Language == FormatStyle::LK_TextProto) {
265     // We need this in order to deal with the bin packing of text fields at
266     // global scope.
267     State.Stack.back().AvoidBinPacking = true;
268     State.Stack.back().BreakBeforeParameter = true;
269     State.Stack.back().AlignColons = false;
270   }
271 
272   // The first token has already been indented and thus consumed.
273   moveStateToNextToken(State, DryRun, /*Newline=*/false);
274   return State;
275 }
276 
277 bool ContinuationIndenter::canBreak(const LineState &State) {
278   const FormatToken &Current = *State.NextToken;
279   const FormatToken &Previous = *Current.Previous;
280   assert(&Previous == Current.Previous);
281   if (!Current.CanBreakBefore && !(State.Stack.back().BreakBeforeClosingBrace &&
282                                    Current.closesBlockOrBlockTypeList(Style)))
283     return false;
284   // The opening "{" of a braced list has to be on the same line as the first
285   // element if it is nested in another braced init list or function call.
286   if (!Current.MustBreakBefore && Previous.is(tok::l_brace) &&
287       Previous.isNot(TT_DictLiteral) && Previous.BlockKind == BK_BracedInit &&
288       Previous.Previous &&
289       Previous.Previous->isOneOf(tok::l_brace, tok::l_paren, tok::comma))
290     return false;
291   // This prevents breaks like:
292   //   ...
293   //   SomeParameter, OtherParameter).DoSomething(
294   //   ...
295   // As they hide "DoSomething" and are generally bad for readability.
296   if (Previous.opensScope() && Previous.isNot(tok::l_brace) &&
297       State.LowestLevelOnLine < State.StartOfLineLevel &&
298       State.LowestLevelOnLine < Current.NestingLevel)
299     return false;
300   if (Current.isMemberAccess() && State.Stack.back().ContainsUnwrappedBuilder)
301     return false;
302 
303   // Don't create a 'hanging' indent if there are multiple blocks in a single
304   // statement.
305   if (Previous.is(tok::l_brace) && State.Stack.size() > 1 &&
306       State.Stack[State.Stack.size() - 2].NestedBlockInlined &&
307       State.Stack[State.Stack.size() - 2].HasMultipleNestedBlocks)
308     return false;
309 
310   // Don't break after very short return types (e.g. "void") as that is often
311   // unexpected.
312   if (Current.is(TT_FunctionDeclarationName) && State.Column < 6) {
313     if (Style.AlwaysBreakAfterReturnType == FormatStyle::RTBS_None)
314       return false;
315   }
316 
317   // If binary operators are moved to the next line (including commas for some
318   // styles of constructor initializers), that's always ok.
319   if (!Current.isOneOf(TT_BinaryOperator, tok::comma) &&
320       State.Stack.back().NoLineBreakInOperand)
321     return false;
322 
323   if (Previous.is(tok::l_square) && Previous.is(TT_ObjCMethodExpr))
324     return false;
325 
326   return !State.Stack.back().NoLineBreak;
327 }
328 
329 bool ContinuationIndenter::mustBreak(const LineState &State) {
330   const FormatToken &Current = *State.NextToken;
331   const FormatToken &Previous = *Current.Previous;
332   if (Style.BraceWrapping.BeforeLambdaBody && Current.CanBreakBefore &&
333       Current.is(TT_LambdaLBrace)) {
334     auto LambdaBodyLength = getLengthToMatchingParen(Current, State.Stack);
335     return (LambdaBodyLength > getColumnLimit(State));
336   }
337   if (Current.MustBreakBefore || Current.is(TT_InlineASMColon))
338     return true;
339   if (State.Stack.back().BreakBeforeClosingBrace &&
340       Current.closesBlockOrBlockTypeList(Style))
341     return true;
342   if (Previous.is(tok::semi) && State.LineContainsContinuedForLoopSection)
343     return true;
344   if (Style.Language == FormatStyle::LK_ObjC &&
345       Current.ObjCSelectorNameParts > 1 &&
346       Current.startsSequence(TT_SelectorName, tok::colon, tok::caret)) {
347     return true;
348   }
349   // Avoid producing inconsistent states by requiring breaks where they are not
350   // permitted for C# generic type constraints.
351   if (State.Stack.back().IsCSharpGenericTypeConstraint &&
352       Previous.isNot(TT_CSharpGenericTypeConstraintComma))
353     return false;
354   if ((startsNextParameter(Current, Style) || Previous.is(tok::semi) ||
355        (Previous.is(TT_TemplateCloser) && Current.is(TT_StartOfName) &&
356         Style.isCpp() &&
357         // FIXME: This is a temporary workaround for the case where clang-format
358         // sets BreakBeforeParameter to avoid bin packing and this creates a
359         // completely unnecessary line break after a template type that isn't
360         // line-wrapped.
361         (Previous.NestingLevel == 1 || Style.BinPackParameters)) ||
362        (Style.BreakBeforeTernaryOperators && Current.is(TT_ConditionalExpr) &&
363         Previous.isNot(tok::question)) ||
364        (!Style.BreakBeforeTernaryOperators &&
365         Previous.is(TT_ConditionalExpr))) &&
366       State.Stack.back().BreakBeforeParameter && !Current.isTrailingComment() &&
367       !Current.isOneOf(tok::r_paren, tok::r_brace))
368     return true;
369   if (((Previous.is(TT_DictLiteral) && Previous.is(tok::l_brace)) ||
370        (Previous.is(TT_ArrayInitializerLSquare) &&
371         Previous.ParameterCount > 1) ||
372        opensProtoMessageField(Previous, Style)) &&
373       Style.ColumnLimit > 0 &&
374       getLengthToMatchingParen(Previous, State.Stack) + State.Column - 1 >
375           getColumnLimit(State))
376     return true;
377 
378   const FormatToken &BreakConstructorInitializersToken =
379       Style.BreakConstructorInitializers == FormatStyle::BCIS_AfterColon
380           ? Previous
381           : Current;
382   if (BreakConstructorInitializersToken.is(TT_CtorInitializerColon) &&
383       (State.Column + State.Line->Last->TotalLength - Previous.TotalLength >
384            getColumnLimit(State) ||
385        State.Stack.back().BreakBeforeParameter) &&
386       (Style.AllowShortFunctionsOnASingleLine != FormatStyle::SFS_All ||
387        Style.BreakConstructorInitializers != FormatStyle::BCIS_BeforeColon ||
388        Style.ColumnLimit != 0))
389     return true;
390 
391   if (Current.is(TT_ObjCMethodExpr) && !Previous.is(TT_SelectorName) &&
392       State.Line->startsWith(TT_ObjCMethodSpecifier))
393     return true;
394   if (Current.is(TT_SelectorName) && !Previous.is(tok::at) &&
395       State.Stack.back().ObjCSelectorNameFound &&
396       State.Stack.back().BreakBeforeParameter)
397     return true;
398 
399   unsigned NewLineColumn = getNewLineColumn(State);
400   if (Current.isMemberAccess() && Style.ColumnLimit != 0 &&
401       State.Column + getLengthToNextOperator(Current) > Style.ColumnLimit &&
402       (State.Column > NewLineColumn ||
403        Current.NestingLevel < State.StartOfLineLevel))
404     return true;
405 
406   if (startsSegmentOfBuilderTypeCall(Current) &&
407       (State.Stack.back().CallContinuation != 0 ||
408        State.Stack.back().BreakBeforeParameter) &&
409       // JavaScript is treated different here as there is a frequent pattern:
410       //   SomeFunction(function() {
411       //     ...
412       //   }.bind(...));
413       // FIXME: We should find a more generic solution to this problem.
414       !(State.Column <= NewLineColumn &&
415         Style.Language == FormatStyle::LK_JavaScript) &&
416       !(Previous.closesScopeAfterBlock() && State.Column <= NewLineColumn))
417     return true;
418 
419   // If the template declaration spans multiple lines, force wrap before the
420   // function/class declaration
421   if (Previous.ClosesTemplateDeclaration &&
422       State.Stack.back().BreakBeforeParameter && Current.CanBreakBefore)
423     return true;
424 
425   if (State.Column <= NewLineColumn)
426     return false;
427 
428   if (Style.AlwaysBreakBeforeMultilineStrings &&
429       (NewLineColumn == State.FirstIndent + Style.ContinuationIndentWidth ||
430        Previous.is(tok::comma) || Current.NestingLevel < 2) &&
431       !Previous.isOneOf(tok::kw_return, tok::lessless, tok::at,
432                         Keywords.kw_dollar) &&
433       !Previous.isOneOf(TT_InlineASMColon, TT_ConditionalExpr) &&
434       nextIsMultilineString(State))
435     return true;
436 
437   // Using CanBreakBefore here and below takes care of the decision whether the
438   // current style uses wrapping before or after operators for the given
439   // operator.
440   if (Previous.is(TT_BinaryOperator) && Current.CanBreakBefore) {
441     // If we need to break somewhere inside the LHS of a binary expression, we
442     // should also break after the operator. Otherwise, the formatting would
443     // hide the operator precedence, e.g. in:
444     //   if (aaaaaaaaaaaaaa ==
445     //           bbbbbbbbbbbbbb && c) {..
446     // For comparisons, we only apply this rule, if the LHS is a binary
447     // expression itself as otherwise, the line breaks seem superfluous.
448     // We need special cases for ">>" which we have split into two ">" while
449     // lexing in order to make template parsing easier.
450     bool IsComparison = (Previous.getPrecedence() == prec::Relational ||
451                          Previous.getPrecedence() == prec::Equality ||
452                          Previous.getPrecedence() == prec::Spaceship) &&
453                         Previous.Previous &&
454                         Previous.Previous->isNot(TT_BinaryOperator); // For >>.
455     bool LHSIsBinaryExpr =
456         Previous.Previous && Previous.Previous->EndsBinaryExpression;
457     if ((!IsComparison || LHSIsBinaryExpr) && !Current.isTrailingComment() &&
458         Previous.getPrecedence() != prec::Assignment &&
459         State.Stack.back().BreakBeforeParameter)
460       return true;
461   } else if (Current.is(TT_BinaryOperator) && Current.CanBreakBefore &&
462              State.Stack.back().BreakBeforeParameter) {
463     return true;
464   }
465 
466   // Same as above, but for the first "<<" operator.
467   if (Current.is(tok::lessless) && Current.isNot(TT_OverloadedOperator) &&
468       State.Stack.back().BreakBeforeParameter &&
469       State.Stack.back().FirstLessLess == 0)
470     return true;
471 
472   if (Current.NestingLevel == 0 && !Current.isTrailingComment()) {
473     // Always break after "template <...>" and leading annotations. This is only
474     // for cases where the entire line does not fit on a single line as a
475     // different LineFormatter would be used otherwise.
476     if (Previous.ClosesTemplateDeclaration)
477       return Style.AlwaysBreakTemplateDeclarations != FormatStyle::BTDS_No;
478     if (Previous.is(TT_FunctionAnnotationRParen))
479       return true;
480     if (Previous.is(TT_LeadingJavaAnnotation) && Current.isNot(tok::l_paren) &&
481         Current.isNot(TT_LeadingJavaAnnotation))
482       return true;
483   }
484 
485   // If the return type spans multiple lines, wrap before the function name.
486   if (((Current.is(TT_FunctionDeclarationName) &&
487         // Don't break before a C# function when no break after return type
488         (!Style.isCSharp() ||
489          Style.AlwaysBreakAfterReturnType != FormatStyle::RTBS_None)) ||
490        (Current.is(tok::kw_operator) && !Previous.is(tok::coloncolon))) &&
491       !Previous.is(tok::kw_template) && State.Stack.back().BreakBeforeParameter)
492     return true;
493 
494   // The following could be precomputed as they do not depend on the state.
495   // However, as they should take effect only if the UnwrappedLine does not fit
496   // into the ColumnLimit, they are checked here in the ContinuationIndenter.
497   if (Style.ColumnLimit != 0 && Previous.BlockKind == BK_Block &&
498       Previous.is(tok::l_brace) && !Current.isOneOf(tok::r_brace, tok::comment))
499     return true;
500 
501   if (Current.is(tok::lessless) &&
502       ((Previous.is(tok::identifier) && Previous.TokenText == "endl") ||
503        (Previous.Tok.isLiteral() && (Previous.TokenText.endswith("\\n\"") ||
504                                      Previous.TokenText == "\'\\n\'"))))
505     return true;
506 
507   if (Previous.is(TT_BlockComment) && Previous.IsMultiline)
508     return true;
509 
510   if (State.NoContinuation)
511     return true;
512 
513   return false;
514 }
515 
516 unsigned ContinuationIndenter::addTokenToState(LineState &State, bool Newline,
517                                                bool DryRun,
518                                                unsigned ExtraSpaces) {
519   const FormatToken &Current = *State.NextToken;
520 
521   assert(!State.Stack.empty());
522   State.NoContinuation = false;
523 
524   if ((Current.is(TT_ImplicitStringLiteral) &&
525        (Current.Previous->Tok.getIdentifierInfo() == nullptr ||
526         Current.Previous->Tok.getIdentifierInfo()->getPPKeywordID() ==
527             tok::pp_not_keyword))) {
528     unsigned EndColumn =
529         SourceMgr.getSpellingColumnNumber(Current.WhitespaceRange.getEnd());
530     if (Current.LastNewlineOffset != 0) {
531       // If there is a newline within this token, the final column will solely
532       // determined by the current end column.
533       State.Column = EndColumn;
534     } else {
535       unsigned StartColumn =
536           SourceMgr.getSpellingColumnNumber(Current.WhitespaceRange.getBegin());
537       assert(EndColumn >= StartColumn);
538       State.Column += EndColumn - StartColumn;
539     }
540     moveStateToNextToken(State, DryRun, /*Newline=*/false);
541     return 0;
542   }
543 
544   unsigned Penalty = 0;
545   if (Newline)
546     Penalty = addTokenOnNewLine(State, DryRun);
547   else
548     addTokenOnCurrentLine(State, DryRun, ExtraSpaces);
549 
550   return moveStateToNextToken(State, DryRun, Newline) + Penalty;
551 }
552 
553 void ContinuationIndenter::addTokenOnCurrentLine(LineState &State, bool DryRun,
554                                                  unsigned ExtraSpaces) {
555   FormatToken &Current = *State.NextToken;
556   const FormatToken &Previous = *State.NextToken->Previous;
557   if (Current.is(tok::equal) &&
558       (State.Line->First->is(tok::kw_for) || Current.NestingLevel == 0) &&
559       State.Stack.back().VariablePos == 0) {
560     State.Stack.back().VariablePos = State.Column;
561     // Move over * and & if they are bound to the variable name.
562     const FormatToken *Tok = &Previous;
563     while (Tok && State.Stack.back().VariablePos >= Tok->ColumnWidth) {
564       State.Stack.back().VariablePos -= Tok->ColumnWidth;
565       if (Tok->SpacesRequiredBefore != 0)
566         break;
567       Tok = Tok->Previous;
568     }
569     if (Previous.PartOfMultiVariableDeclStmt)
570       State.Stack.back().LastSpace = State.Stack.back().VariablePos;
571   }
572 
573   unsigned Spaces = Current.SpacesRequiredBefore + ExtraSpaces;
574 
575   // Indent preprocessor directives after the hash if required.
576   int PPColumnCorrection = 0;
577   if (Style.IndentPPDirectives == FormatStyle::PPDIS_AfterHash &&
578       Previous.is(tok::hash) && State.FirstIndent > 0 &&
579       (State.Line->Type == LT_PreprocessorDirective ||
580        State.Line->Type == LT_ImportStatement)) {
581     Spaces += State.FirstIndent;
582 
583     // For preprocessor indent with tabs, State.Column will be 1 because of the
584     // hash. This causes second-level indents onward to have an extra space
585     // after the tabs. We avoid this misalignment by subtracting 1 from the
586     // column value passed to replaceWhitespace().
587     if (Style.UseTab != FormatStyle::UT_Never)
588       PPColumnCorrection = -1;
589   }
590 
591   if (!DryRun)
592     Whitespaces.replaceWhitespace(Current, /*Newlines=*/0, Spaces,
593                                   State.Column + Spaces + PPColumnCorrection);
594 
595   // If "BreakBeforeInheritanceComma" mode, don't break within the inheritance
596   // declaration unless there is multiple inheritance.
597   if (Style.BreakInheritanceList == FormatStyle::BILS_BeforeComma &&
598       Current.is(TT_InheritanceColon))
599     State.Stack.back().NoLineBreak = true;
600   if (Style.BreakInheritanceList == FormatStyle::BILS_AfterColon &&
601       Previous.is(TT_InheritanceColon))
602     State.Stack.back().NoLineBreak = true;
603 
604   if (Current.is(TT_SelectorName) &&
605       !State.Stack.back().ObjCSelectorNameFound) {
606     unsigned MinIndent =
607         std::max(State.FirstIndent + Style.ContinuationIndentWidth,
608                  State.Stack.back().Indent);
609     unsigned FirstColonPos = State.Column + Spaces + Current.ColumnWidth;
610     if (Current.LongestObjCSelectorName == 0)
611       State.Stack.back().AlignColons = false;
612     else if (MinIndent + Current.LongestObjCSelectorName > FirstColonPos)
613       State.Stack.back().ColonPos = MinIndent + Current.LongestObjCSelectorName;
614     else
615       State.Stack.back().ColonPos = FirstColonPos;
616   }
617 
618   // In "AlwaysBreak" mode, enforce wrapping directly after the parenthesis by
619   // disallowing any further line breaks if there is no line break after the
620   // opening parenthesis. Don't break if it doesn't conserve columns.
621   if (Style.AlignAfterOpenBracket == FormatStyle::BAS_AlwaysBreak &&
622       (Previous.isOneOf(tok::l_paren, TT_TemplateOpener, tok::l_square) ||
623        (Previous.is(tok::l_brace) && Previous.BlockKind != BK_Block &&
624         Style.Cpp11BracedListStyle)) &&
625       State.Column > getNewLineColumn(State) &&
626       (!Previous.Previous || !Previous.Previous->isOneOf(
627                                  tok::kw_for, tok::kw_while, tok::kw_switch)) &&
628       // Don't do this for simple (no expressions) one-argument function calls
629       // as that feels like needlessly wasting whitespace, e.g.:
630       //
631       //   caaaaaaaaaaaall(
632       //       caaaaaaaaaaaall(
633       //           caaaaaaaaaaaall(
634       //               caaaaaaaaaaaaaaaaaaaaaaall(aaaaaaaaaaaaaa, aaaaaaaaa))));
635       Current.FakeLParens.size() > 0 &&
636       Current.FakeLParens.back() > prec::Unknown)
637     State.Stack.back().NoLineBreak = true;
638   if (Previous.is(TT_TemplateString) && Previous.opensScope())
639     State.Stack.back().NoLineBreak = true;
640 
641   if (Style.AlignAfterOpenBracket != FormatStyle::BAS_DontAlign &&
642       !State.Stack.back().IsCSharpGenericTypeConstraint &&
643       Previous.opensScope() && Previous.isNot(TT_ObjCMethodExpr) &&
644       (Current.isNot(TT_LineComment) || Previous.BlockKind == BK_BracedInit))
645     State.Stack.back().Indent = State.Column + Spaces;
646   if (State.Stack.back().AvoidBinPacking && startsNextParameter(Current, Style))
647     State.Stack.back().NoLineBreak = true;
648   if (startsSegmentOfBuilderTypeCall(Current) &&
649       State.Column > getNewLineColumn(State))
650     State.Stack.back().ContainsUnwrappedBuilder = true;
651 
652   if (Current.is(TT_LambdaArrow) && Style.Language == FormatStyle::LK_Java)
653     State.Stack.back().NoLineBreak = true;
654   if (Current.isMemberAccess() && Previous.is(tok::r_paren) &&
655       (Previous.MatchingParen &&
656        (Previous.TotalLength - Previous.MatchingParen->TotalLength > 10)))
657     // If there is a function call with long parameters, break before trailing
658     // calls. This prevents things like:
659     //   EXPECT_CALL(SomeLongParameter).Times(
660     //       2);
661     // We don't want to do this for short parameters as they can just be
662     // indexes.
663     State.Stack.back().NoLineBreak = true;
664 
665   // Don't allow the RHS of an operator to be split over multiple lines unless
666   // there is a line-break right after the operator.
667   // Exclude relational operators, as there, it is always more desirable to
668   // have the LHS 'left' of the RHS.
669   const FormatToken *P = Current.getPreviousNonComment();
670   if (!Current.is(tok::comment) && P &&
671       (P->isOneOf(TT_BinaryOperator, tok::comma) ||
672        (P->is(TT_ConditionalExpr) && P->is(tok::colon))) &&
673       !P->isOneOf(TT_OverloadedOperator, TT_CtorInitializerComma) &&
674       P->getPrecedence() != prec::Assignment &&
675       P->getPrecedence() != prec::Relational &&
676       P->getPrecedence() != prec::Spaceship) {
677     bool BreakBeforeOperator =
678         P->MustBreakBefore || P->is(tok::lessless) ||
679         (P->is(TT_BinaryOperator) &&
680          Style.BreakBeforeBinaryOperators != FormatStyle::BOS_None) ||
681         (P->is(TT_ConditionalExpr) && Style.BreakBeforeTernaryOperators);
682     // Don't do this if there are only two operands. In these cases, there is
683     // always a nice vertical separation between them and the extra line break
684     // does not help.
685     bool HasTwoOperands =
686         P->OperatorIndex == 0 && !P->NextOperator && !P->is(TT_ConditionalExpr);
687     if ((!BreakBeforeOperator && !(HasTwoOperands && Style.AlignOperands)) ||
688         (!State.Stack.back().LastOperatorWrapped && BreakBeforeOperator))
689       State.Stack.back().NoLineBreakInOperand = true;
690   }
691 
692   State.Column += Spaces;
693   if (Current.isNot(tok::comment) && Previous.is(tok::l_paren) &&
694       Previous.Previous &&
695       (Previous.Previous->is(tok::kw_for) || Previous.Previous->isIf())) {
696     // Treat the condition inside an if as if it was a second function
697     // parameter, i.e. let nested calls have a continuation indent.
698     State.Stack.back().LastSpace = State.Column;
699     State.Stack.back().NestedBlockIndent = State.Column;
700   } else if (!Current.isOneOf(tok::comment, tok::caret) &&
701              ((Previous.is(tok::comma) &&
702                !Previous.is(TT_OverloadedOperator)) ||
703               (Previous.is(tok::colon) && Previous.is(TT_ObjCMethodExpr)))) {
704     State.Stack.back().LastSpace = State.Column;
705   } else if (Previous.is(TT_CtorInitializerColon) &&
706              Style.BreakConstructorInitializers ==
707                  FormatStyle::BCIS_AfterColon) {
708     State.Stack.back().Indent = State.Column;
709     State.Stack.back().LastSpace = State.Column;
710   } else if ((Previous.isOneOf(TT_BinaryOperator, TT_ConditionalExpr,
711                                TT_CtorInitializerColon)) &&
712              ((Previous.getPrecedence() != prec::Assignment &&
713                (Previous.isNot(tok::lessless) || Previous.OperatorIndex != 0 ||
714                 Previous.NextOperator)) ||
715               Current.StartsBinaryExpression)) {
716     // Indent relative to the RHS of the expression unless this is a simple
717     // assignment without binary expression on the RHS. Also indent relative to
718     // unary operators and the colons of constructor initializers.
719     if (Style.BreakBeforeBinaryOperators == FormatStyle::BOS_None)
720       State.Stack.back().LastSpace = State.Column;
721   } else if (Previous.is(TT_InheritanceColon)) {
722     State.Stack.back().Indent = State.Column;
723     State.Stack.back().LastSpace = State.Column;
724   } else if (Current.is(TT_CSharpGenericTypeConstraintColon)) {
725     State.Stack.back().ColonPos = State.Column;
726   } else if (Previous.opensScope()) {
727     // If a function has a trailing call, indent all parameters from the
728     // opening parenthesis. This avoids confusing indents like:
729     //   OuterFunction(InnerFunctionCall( // break
730     //       ParameterToInnerFunction))   // break
731     //       .SecondInnerFunctionCall();
732     bool HasTrailingCall = false;
733     if (Previous.MatchingParen) {
734       const FormatToken *Next = Previous.MatchingParen->getNextNonComment();
735       HasTrailingCall = Next && Next->isMemberAccess();
736     }
737     if (HasTrailingCall && State.Stack.size() > 1 &&
738         State.Stack[State.Stack.size() - 2].CallContinuation == 0)
739       State.Stack.back().LastSpace = State.Column;
740   }
741 }
742 
743 unsigned ContinuationIndenter::addTokenOnNewLine(LineState &State,
744                                                  bool DryRun) {
745   FormatToken &Current = *State.NextToken;
746   const FormatToken &Previous = *State.NextToken->Previous;
747 
748   // Extra penalty that needs to be added because of the way certain line
749   // breaks are chosen.
750   unsigned Penalty = 0;
751 
752   const FormatToken *PreviousNonComment = Current.getPreviousNonComment();
753   const FormatToken *NextNonComment = Previous.getNextNonComment();
754   if (!NextNonComment)
755     NextNonComment = &Current;
756   // The first line break on any NestingLevel causes an extra penalty in order
757   // prefer similar line breaks.
758   if (!State.Stack.back().ContainsLineBreak)
759     Penalty += 15;
760   State.Stack.back().ContainsLineBreak = true;
761 
762   Penalty += State.NextToken->SplitPenalty;
763 
764   // Breaking before the first "<<" is generally not desirable if the LHS is
765   // short. Also always add the penalty if the LHS is split over multiple lines
766   // to avoid unnecessary line breaks that just work around this penalty.
767   if (NextNonComment->is(tok::lessless) &&
768       State.Stack.back().FirstLessLess == 0 &&
769       (State.Column <= Style.ColumnLimit / 3 ||
770        State.Stack.back().BreakBeforeParameter))
771     Penalty += Style.PenaltyBreakFirstLessLess;
772 
773   State.Column = getNewLineColumn(State);
774 
775   // Indent nested blocks relative to this column, unless in a very specific
776   // JavaScript special case where:
777   //
778   //   var loooooong_name =
779   //       function() {
780   //     // code
781   //   }
782   //
783   // is common and should be formatted like a free-standing function. The same
784   // goes for wrapping before the lambda return type arrow.
785   if (!Current.is(TT_LambdaArrow) &&
786       (Style.Language != FormatStyle::LK_JavaScript ||
787        Current.NestingLevel != 0 || !PreviousNonComment ||
788        !PreviousNonComment->is(tok::equal) ||
789        !Current.isOneOf(Keywords.kw_async, Keywords.kw_function)))
790     State.Stack.back().NestedBlockIndent = State.Column;
791 
792   if (NextNonComment->isMemberAccess()) {
793     if (State.Stack.back().CallContinuation == 0)
794       State.Stack.back().CallContinuation = State.Column;
795   } else if (NextNonComment->is(TT_SelectorName)) {
796     if (!State.Stack.back().ObjCSelectorNameFound) {
797       if (NextNonComment->LongestObjCSelectorName == 0) {
798         State.Stack.back().AlignColons = false;
799       } else {
800         State.Stack.back().ColonPos =
801             (shouldIndentWrappedSelectorName(Style, State.Line->Type)
802                  ? std::max(State.Stack.back().Indent,
803                             State.FirstIndent + Style.ContinuationIndentWidth)
804                  : State.Stack.back().Indent) +
805             std::max(NextNonComment->LongestObjCSelectorName,
806                      NextNonComment->ColumnWidth);
807       }
808     } else if (State.Stack.back().AlignColons &&
809                State.Stack.back().ColonPos <= NextNonComment->ColumnWidth) {
810       State.Stack.back().ColonPos = State.Column + NextNonComment->ColumnWidth;
811     }
812   } else if (PreviousNonComment && PreviousNonComment->is(tok::colon) &&
813              PreviousNonComment->isOneOf(TT_ObjCMethodExpr, TT_DictLiteral)) {
814     // FIXME: This is hacky, find a better way. The problem is that in an ObjC
815     // method expression, the block should be aligned to the line starting it,
816     // e.g.:
817     //   [aaaaaaaaaaaaaaa aaaaaaaaa: \\ break for some reason
818     //                        ^(int *i) {
819     //                            // ...
820     //                        }];
821     // Thus, we set LastSpace of the next higher NestingLevel, to which we move
822     // when we consume all of the "}"'s FakeRParens at the "{".
823     if (State.Stack.size() > 1)
824       State.Stack[State.Stack.size() - 2].LastSpace =
825           std::max(State.Stack.back().LastSpace, State.Stack.back().Indent) +
826           Style.ContinuationIndentWidth;
827   }
828 
829   if ((PreviousNonComment &&
830        PreviousNonComment->isOneOf(tok::comma, tok::semi) &&
831        !State.Stack.back().AvoidBinPacking) ||
832       Previous.is(TT_BinaryOperator))
833     State.Stack.back().BreakBeforeParameter = false;
834   if (PreviousNonComment &&
835       PreviousNonComment->isOneOf(TT_TemplateCloser, TT_JavaAnnotation) &&
836       Current.NestingLevel == 0)
837     State.Stack.back().BreakBeforeParameter = false;
838   if (NextNonComment->is(tok::question) ||
839       (PreviousNonComment && PreviousNonComment->is(tok::question)))
840     State.Stack.back().BreakBeforeParameter = true;
841   if (Current.is(TT_BinaryOperator) && Current.CanBreakBefore)
842     State.Stack.back().BreakBeforeParameter = false;
843 
844   if (!DryRun) {
845     unsigned MaxEmptyLinesToKeep = Style.MaxEmptyLinesToKeep + 1;
846     if (Current.is(tok::r_brace) && Current.MatchingParen &&
847         // Only strip trailing empty lines for l_braces that have children, i.e.
848         // for function expressions (lambdas, arrows, etc).
849         !Current.MatchingParen->Children.empty()) {
850       // lambdas and arrow functions are expressions, thus their r_brace is not
851       // on its own line, and thus not covered by UnwrappedLineFormatter's logic
852       // about removing empty lines on closing blocks. Special case them here.
853       MaxEmptyLinesToKeep = 1;
854     }
855     unsigned Newlines =
856         std::max(1u, std::min(Current.NewlinesBefore, MaxEmptyLinesToKeep));
857     bool ContinuePPDirective =
858         State.Line->InPPDirective && State.Line->Type != LT_ImportStatement;
859     Whitespaces.replaceWhitespace(Current, Newlines, State.Column, State.Column,
860                                   ContinuePPDirective);
861   }
862 
863   if (!Current.isTrailingComment())
864     State.Stack.back().LastSpace = State.Column;
865   if (Current.is(tok::lessless))
866     // If we are breaking before a "<<", we always want to indent relative to
867     // RHS. This is necessary only for "<<", as we special-case it and don't
868     // always indent relative to the RHS.
869     State.Stack.back().LastSpace += 3; // 3 -> width of "<< ".
870 
871   State.StartOfLineLevel = Current.NestingLevel;
872   State.LowestLevelOnLine = Current.NestingLevel;
873 
874   // Any break on this level means that the parent level has been broken
875   // and we need to avoid bin packing there.
876   bool NestedBlockSpecialCase =
877       (!Style.isCpp() && Current.is(tok::r_brace) && State.Stack.size() > 1 &&
878        State.Stack[State.Stack.size() - 2].NestedBlockInlined) ||
879       (Style.Language == FormatStyle::LK_ObjC && Current.is(tok::r_brace) &&
880        State.Stack.size() > 1 && !Style.ObjCBreakBeforeNestedBlockParam);
881   if (!NestedBlockSpecialCase)
882     for (unsigned i = 0, e = State.Stack.size() - 1; i != e; ++i)
883       State.Stack[i].BreakBeforeParameter = true;
884 
885   if (PreviousNonComment &&
886       !PreviousNonComment->isOneOf(tok::comma, tok::colon, tok::semi) &&
887       (PreviousNonComment->isNot(TT_TemplateCloser) ||
888        Current.NestingLevel != 0) &&
889       !PreviousNonComment->isOneOf(
890           TT_BinaryOperator, TT_FunctionAnnotationRParen, TT_JavaAnnotation,
891           TT_LeadingJavaAnnotation) &&
892       Current.isNot(TT_BinaryOperator) && !PreviousNonComment->opensScope())
893     State.Stack.back().BreakBeforeParameter = true;
894 
895   // If we break after { or the [ of an array initializer, we should also break
896   // before the corresponding } or ].
897   if (PreviousNonComment &&
898       (PreviousNonComment->isOneOf(tok::l_brace, TT_ArrayInitializerLSquare) ||
899        opensProtoMessageField(*PreviousNonComment, Style)))
900     State.Stack.back().BreakBeforeClosingBrace = true;
901 
902   if (State.Stack.back().AvoidBinPacking) {
903     // If we are breaking after '(', '{', '<', or this is the break after a ':'
904     // to start a member initializater list in a constructor, this should not
905     // be considered bin packing unless the relevant AllowAll option is false or
906     // this is a dict/object literal.
907     bool PreviousIsBreakingCtorInitializerColon =
908         Previous.is(TT_CtorInitializerColon) &&
909         Style.BreakConstructorInitializers == FormatStyle::BCIS_AfterColon;
910     if (!(Previous.isOneOf(tok::l_paren, tok::l_brace, TT_BinaryOperator) ||
911           PreviousIsBreakingCtorInitializerColon) ||
912         (!Style.AllowAllParametersOfDeclarationOnNextLine &&
913          State.Line->MustBeDeclaration) ||
914         (!Style.AllowAllArgumentsOnNextLine &&
915          !State.Line->MustBeDeclaration) ||
916         (!Style.AllowAllConstructorInitializersOnNextLine &&
917          PreviousIsBreakingCtorInitializerColon) ||
918         Previous.is(TT_DictLiteral))
919       State.Stack.back().BreakBeforeParameter = true;
920 
921     // If we are breaking after a ':' to start a member initializer list,
922     // and we allow all arguments on the next line, we should not break
923     // before the next parameter.
924     if (PreviousIsBreakingCtorInitializerColon &&
925         Style.AllowAllConstructorInitializersOnNextLine)
926       State.Stack.back().BreakBeforeParameter = false;
927   }
928 
929   return Penalty;
930 }
931 
932 unsigned ContinuationIndenter::getNewLineColumn(const LineState &State) {
933   if (!State.NextToken || !State.NextToken->Previous)
934     return 0;
935 
936   FormatToken &Current = *State.NextToken;
937 
938   if (State.Stack.back().IsCSharpGenericTypeConstraint &&
939       Current.isNot(TT_CSharpGenericTypeConstraint))
940     return State.Stack.back().ColonPos + 2;
941 
942   const FormatToken &Previous = *Current.Previous;
943   // If we are continuing an expression, we want to use the continuation indent.
944   unsigned ContinuationIndent =
945       std::max(State.Stack.back().LastSpace, State.Stack.back().Indent) +
946       Style.ContinuationIndentWidth;
947   const FormatToken *PreviousNonComment = Current.getPreviousNonComment();
948   const FormatToken *NextNonComment = Previous.getNextNonComment();
949   if (!NextNonComment)
950     NextNonComment = &Current;
951 
952   // Java specific bits.
953   if (Style.Language == FormatStyle::LK_Java &&
954       Current.isOneOf(Keywords.kw_implements, Keywords.kw_extends))
955     return std::max(State.Stack.back().LastSpace,
956                     State.Stack.back().Indent + Style.ContinuationIndentWidth);
957 
958   if (Style.BreakBeforeBraces == FormatStyle::BS_Whitesmiths &&
959       State.Line->First->is(tok::kw_enum))
960     return (Style.IndentWidth * State.Line->First->IndentLevel) +
961            Style.IndentWidth;
962 
963   if (NextNonComment->is(tok::l_brace) && NextNonComment->BlockKind == BK_Block)
964     return Current.NestingLevel == 0 ? State.FirstIndent
965                                      : State.Stack.back().Indent;
966   if ((Current.isOneOf(tok::r_brace, tok::r_square) ||
967        (Current.is(tok::greater) &&
968         (Style.Language == FormatStyle::LK_Proto ||
969          Style.Language == FormatStyle::LK_TextProto))) &&
970       State.Stack.size() > 1) {
971     if (Current.closesBlockOrBlockTypeList(Style))
972       return State.Stack[State.Stack.size() - 2].NestedBlockIndent;
973     if (Current.MatchingParen &&
974         Current.MatchingParen->BlockKind == BK_BracedInit)
975       return State.Stack[State.Stack.size() - 2].LastSpace;
976     return State.FirstIndent;
977   }
978   // Indent a closing parenthesis at the previous level if followed by a semi,
979   // const, or opening brace. This allows indentations such as:
980   //     foo(
981   //       a,
982   //     );
983   //     int Foo::getter(
984   //         //
985   //     ) const {
986   //       return foo;
987   //     }
988   //     function foo(
989   //       a,
990   //     ) {
991   //       code(); //
992   //     }
993   if (Current.is(tok::r_paren) && State.Stack.size() > 1 &&
994       (!Current.Next ||
995        Current.Next->isOneOf(tok::semi, tok::kw_const, tok::l_brace)))
996     return State.Stack[State.Stack.size() - 2].LastSpace;
997   if (NextNonComment->is(TT_TemplateString) && NextNonComment->closesScope())
998     return State.Stack[State.Stack.size() - 2].LastSpace;
999   if (Current.is(tok::identifier) && Current.Next &&
1000       (Current.Next->is(TT_DictLiteral) ||
1001        ((Style.Language == FormatStyle::LK_Proto ||
1002          Style.Language == FormatStyle::LK_TextProto) &&
1003         Current.Next->isOneOf(tok::less, tok::l_brace))))
1004     return State.Stack.back().Indent;
1005   if (NextNonComment->is(TT_ObjCStringLiteral) &&
1006       State.StartOfStringLiteral != 0)
1007     return State.StartOfStringLiteral - 1;
1008   if (NextNonComment->isStringLiteral() && State.StartOfStringLiteral != 0)
1009     return State.StartOfStringLiteral;
1010   if (NextNonComment->is(tok::lessless) &&
1011       State.Stack.back().FirstLessLess != 0)
1012     return State.Stack.back().FirstLessLess;
1013   if (NextNonComment->isMemberAccess()) {
1014     if (State.Stack.back().CallContinuation == 0)
1015       return ContinuationIndent;
1016     return State.Stack.back().CallContinuation;
1017   }
1018   if (State.Stack.back().QuestionColumn != 0 &&
1019       ((NextNonComment->is(tok::colon) &&
1020         NextNonComment->is(TT_ConditionalExpr)) ||
1021        Previous.is(TT_ConditionalExpr)))
1022     return State.Stack.back().QuestionColumn;
1023   if (Previous.is(tok::comma) && State.Stack.back().VariablePos != 0)
1024     return State.Stack.back().VariablePos;
1025   if ((PreviousNonComment &&
1026        (PreviousNonComment->ClosesTemplateDeclaration ||
1027         PreviousNonComment->isOneOf(
1028             TT_AttributeParen, TT_AttributeSquare, TT_FunctionAnnotationRParen,
1029             TT_JavaAnnotation, TT_LeadingJavaAnnotation))) ||
1030       (!Style.IndentWrappedFunctionNames &&
1031        NextNonComment->isOneOf(tok::kw_operator, TT_FunctionDeclarationName)))
1032     return std::max(State.Stack.back().LastSpace, State.Stack.back().Indent);
1033   if (NextNonComment->is(TT_SelectorName)) {
1034     if (!State.Stack.back().ObjCSelectorNameFound) {
1035       unsigned MinIndent = State.Stack.back().Indent;
1036       if (shouldIndentWrappedSelectorName(Style, State.Line->Type))
1037         MinIndent = std::max(MinIndent,
1038                              State.FirstIndent + Style.ContinuationIndentWidth);
1039       // If LongestObjCSelectorName is 0, we are indenting the first
1040       // part of an ObjC selector (or a selector component which is
1041       // not colon-aligned due to block formatting).
1042       //
1043       // Otherwise, we are indenting a subsequent part of an ObjC
1044       // selector which should be colon-aligned to the longest
1045       // component of the ObjC selector.
1046       //
1047       // In either case, we want to respect Style.IndentWrappedFunctionNames.
1048       return MinIndent +
1049              std::max(NextNonComment->LongestObjCSelectorName,
1050                       NextNonComment->ColumnWidth) -
1051              NextNonComment->ColumnWidth;
1052     }
1053     if (!State.Stack.back().AlignColons)
1054       return State.Stack.back().Indent;
1055     if (State.Stack.back().ColonPos > NextNonComment->ColumnWidth)
1056       return State.Stack.back().ColonPos - NextNonComment->ColumnWidth;
1057     return State.Stack.back().Indent;
1058   }
1059   if (NextNonComment->is(tok::colon) && NextNonComment->is(TT_ObjCMethodExpr))
1060     return State.Stack.back().ColonPos;
1061   if (NextNonComment->is(TT_ArraySubscriptLSquare)) {
1062     if (State.Stack.back().StartOfArraySubscripts != 0)
1063       return State.Stack.back().StartOfArraySubscripts;
1064     else if (Style.isCSharp()) // C# allows `["key"] = value` inside object
1065                                // initializers.
1066       return State.Stack.back().Indent;
1067     return ContinuationIndent;
1068   }
1069 
1070   // This ensure that we correctly format ObjC methods calls without inputs,
1071   // i.e. where the last element isn't selector like: [callee method];
1072   if (NextNonComment->is(tok::identifier) && NextNonComment->FakeRParens == 0 &&
1073       NextNonComment->Next && NextNonComment->Next->is(TT_ObjCMethodExpr))
1074     return State.Stack.back().Indent;
1075 
1076   if (NextNonComment->isOneOf(TT_StartOfName, TT_PointerOrReference) ||
1077       Previous.isOneOf(tok::coloncolon, tok::equal, TT_JsTypeColon))
1078     return ContinuationIndent;
1079   if (PreviousNonComment && PreviousNonComment->is(tok::colon) &&
1080       PreviousNonComment->isOneOf(TT_ObjCMethodExpr, TT_DictLiteral))
1081     return ContinuationIndent;
1082   if (NextNonComment->is(TT_CtorInitializerComma))
1083     return State.Stack.back().Indent;
1084   if (PreviousNonComment && PreviousNonComment->is(TT_CtorInitializerColon) &&
1085       Style.BreakConstructorInitializers == FormatStyle::BCIS_AfterColon)
1086     return State.Stack.back().Indent;
1087   if (PreviousNonComment && PreviousNonComment->is(TT_InheritanceColon) &&
1088       Style.BreakInheritanceList == FormatStyle::BILS_AfterColon)
1089     return State.Stack.back().Indent;
1090   if (NextNonComment->isOneOf(TT_CtorInitializerColon, TT_InheritanceColon,
1091                               TT_InheritanceComma))
1092     return State.FirstIndent + Style.ConstructorInitializerIndentWidth;
1093   if (Previous.is(tok::r_paren) && !Current.isBinaryOperator() &&
1094       !Current.isOneOf(tok::colon, tok::comment))
1095     return ContinuationIndent;
1096   if (Current.is(TT_ProtoExtensionLSquare))
1097     return State.Stack.back().Indent;
1098   if (State.Stack.back().Indent == State.FirstIndent && PreviousNonComment &&
1099       !PreviousNonComment->isOneOf(tok::r_brace, TT_CtorInitializerComma))
1100     // Ensure that we fall back to the continuation indent width instead of
1101     // just flushing continuations left.
1102     return State.Stack.back().Indent + Style.ContinuationIndentWidth;
1103   return State.Stack.back().Indent;
1104 }
1105 
1106 static bool hasNestedBlockInlined(const FormatToken *Previous,
1107                                   const FormatToken &Current,
1108                                   const FormatStyle &Style) {
1109   if (Previous->isNot(tok::l_paren))
1110     return true;
1111   if (Previous->ParameterCount > 1)
1112     return true;
1113 
1114   // Also a nested block if contains a lambda inside function with 1 parameter
1115   return (Style.BraceWrapping.BeforeLambdaBody && Current.is(TT_LambdaLSquare));
1116 }
1117 
1118 unsigned ContinuationIndenter::moveStateToNextToken(LineState &State,
1119                                                     bool DryRun, bool Newline) {
1120   assert(State.Stack.size());
1121   const FormatToken &Current = *State.NextToken;
1122 
1123   if (Current.is(TT_CSharpGenericTypeConstraint))
1124     State.Stack.back().IsCSharpGenericTypeConstraint = true;
1125   if (Current.isOneOf(tok::comma, TT_BinaryOperator))
1126     State.Stack.back().NoLineBreakInOperand = false;
1127   if (Current.isOneOf(TT_InheritanceColon, TT_CSharpGenericTypeConstraintColon))
1128     State.Stack.back().AvoidBinPacking = true;
1129   if (Current.is(tok::lessless) && Current.isNot(TT_OverloadedOperator)) {
1130     if (State.Stack.back().FirstLessLess == 0)
1131       State.Stack.back().FirstLessLess = State.Column;
1132     else
1133       State.Stack.back().LastOperatorWrapped = Newline;
1134   }
1135   if (Current.is(TT_BinaryOperator) && Current.isNot(tok::lessless))
1136     State.Stack.back().LastOperatorWrapped = Newline;
1137   if (Current.is(TT_ConditionalExpr) && Current.Previous &&
1138       !Current.Previous->is(TT_ConditionalExpr))
1139     State.Stack.back().LastOperatorWrapped = Newline;
1140   if (Current.is(TT_ArraySubscriptLSquare) &&
1141       State.Stack.back().StartOfArraySubscripts == 0)
1142     State.Stack.back().StartOfArraySubscripts = State.Column;
1143   if (Style.BreakBeforeTernaryOperators && Current.is(tok::question))
1144     State.Stack.back().QuestionColumn = State.Column;
1145   if (!Style.BreakBeforeTernaryOperators && Current.isNot(tok::colon)) {
1146     const FormatToken *Previous = Current.Previous;
1147     while (Previous && Previous->isTrailingComment())
1148       Previous = Previous->Previous;
1149     if (Previous && Previous->is(tok::question))
1150       State.Stack.back().QuestionColumn = State.Column;
1151   }
1152   if (!Current.opensScope() && !Current.closesScope() &&
1153       !Current.is(TT_PointerOrReference))
1154     State.LowestLevelOnLine =
1155         std::min(State.LowestLevelOnLine, Current.NestingLevel);
1156   if (Current.isMemberAccess())
1157     State.Stack.back().StartOfFunctionCall =
1158         !Current.NextOperator ? 0 : State.Column;
1159   if (Current.is(TT_SelectorName))
1160     State.Stack.back().ObjCSelectorNameFound = true;
1161   if (Current.is(TT_CtorInitializerColon) &&
1162       Style.BreakConstructorInitializers != FormatStyle::BCIS_AfterColon) {
1163     // Indent 2 from the column, so:
1164     // SomeClass::SomeClass()
1165     //     : First(...), ...
1166     //       Next(...)
1167     //       ^ line up here.
1168     State.Stack.back().Indent =
1169         State.Column +
1170         (Style.BreakConstructorInitializers == FormatStyle::BCIS_BeforeComma
1171              ? 0
1172              : 2);
1173     State.Stack.back().NestedBlockIndent = State.Stack.back().Indent;
1174     if (Style.ConstructorInitializerAllOnOneLineOrOnePerLine) {
1175       State.Stack.back().AvoidBinPacking = true;
1176       State.Stack.back().BreakBeforeParameter =
1177           !Style.AllowAllConstructorInitializersOnNextLine;
1178     } else {
1179       State.Stack.back().BreakBeforeParameter = false;
1180     }
1181   }
1182   if (Current.is(TT_CtorInitializerColon) &&
1183       Style.BreakConstructorInitializers == FormatStyle::BCIS_AfterColon) {
1184     State.Stack.back().Indent =
1185         State.FirstIndent + Style.ConstructorInitializerIndentWidth;
1186     State.Stack.back().NestedBlockIndent = State.Stack.back().Indent;
1187     if (Style.ConstructorInitializerAllOnOneLineOrOnePerLine)
1188       State.Stack.back().AvoidBinPacking = true;
1189   }
1190   if (Current.is(TT_InheritanceColon))
1191     State.Stack.back().Indent =
1192         State.FirstIndent + Style.ConstructorInitializerIndentWidth;
1193   if (Current.isOneOf(TT_BinaryOperator, TT_ConditionalExpr) && Newline)
1194     State.Stack.back().NestedBlockIndent =
1195         State.Column + Current.ColumnWidth + 1;
1196   if (Current.isOneOf(TT_LambdaLSquare, TT_LambdaArrow))
1197     State.Stack.back().LastSpace = State.Column;
1198 
1199   // Insert scopes created by fake parenthesis.
1200   const FormatToken *Previous = Current.getPreviousNonComment();
1201 
1202   // Add special behavior to support a format commonly used for JavaScript
1203   // closures:
1204   //   SomeFunction(function() {
1205   //     foo();
1206   //     bar();
1207   //   }, a, b, c);
1208   if (Current.isNot(tok::comment) && Previous &&
1209       Previous->isOneOf(tok::l_brace, TT_ArrayInitializerLSquare) &&
1210       !Previous->is(TT_DictLiteral) && State.Stack.size() > 1 &&
1211       !State.Stack.back().HasMultipleNestedBlocks) {
1212     if (State.Stack[State.Stack.size() - 2].NestedBlockInlined && Newline)
1213       for (unsigned i = 0, e = State.Stack.size() - 1; i != e; ++i)
1214         State.Stack[i].NoLineBreak = true;
1215     State.Stack[State.Stack.size() - 2].NestedBlockInlined = false;
1216   }
1217   if (Previous &&
1218       (Previous->isOneOf(tok::l_paren, tok::comma, tok::colon) ||
1219        Previous->isOneOf(TT_BinaryOperator, TT_ConditionalExpr)) &&
1220       !Previous->isOneOf(TT_DictLiteral, TT_ObjCMethodExpr)) {
1221     State.Stack.back().NestedBlockInlined =
1222         !Newline && hasNestedBlockInlined(Previous, Current, Style);
1223   }
1224 
1225   moveStatePastFakeLParens(State, Newline);
1226   moveStatePastScopeCloser(State);
1227   bool AllowBreak = !State.Stack.back().NoLineBreak &&
1228                     !State.Stack.back().NoLineBreakInOperand;
1229   moveStatePastScopeOpener(State, Newline);
1230   moveStatePastFakeRParens(State);
1231 
1232   if (Current.is(TT_ObjCStringLiteral) && State.StartOfStringLiteral == 0)
1233     State.StartOfStringLiteral = State.Column + 1;
1234   if (Current.is(TT_CSharpStringLiteral) && State.StartOfStringLiteral == 0)
1235     State.StartOfStringLiteral = State.Column + 1;
1236   else if (Current.isStringLiteral() && State.StartOfStringLiteral == 0)
1237     State.StartOfStringLiteral = State.Column;
1238   else if (!Current.isOneOf(tok::comment, tok::identifier, tok::hash) &&
1239            !Current.isStringLiteral())
1240     State.StartOfStringLiteral = 0;
1241 
1242   State.Column += Current.ColumnWidth;
1243   State.NextToken = State.NextToken->Next;
1244 
1245   unsigned Penalty =
1246       handleEndOfLine(Current, State, DryRun, AllowBreak, Newline);
1247 
1248   if (Current.Role)
1249     Current.Role->formatFromToken(State, this, DryRun);
1250   // If the previous has a special role, let it consume tokens as appropriate.
1251   // It is necessary to start at the previous token for the only implemented
1252   // role (comma separated list). That way, the decision whether or not to break
1253   // after the "{" is already done and both options are tried and evaluated.
1254   // FIXME: This is ugly, find a better way.
1255   if (Previous && Previous->Role)
1256     Penalty += Previous->Role->formatAfterToken(State, this, DryRun);
1257 
1258   return Penalty;
1259 }
1260 
1261 void ContinuationIndenter::moveStatePastFakeLParens(LineState &State,
1262                                                     bool Newline) {
1263   const FormatToken &Current = *State.NextToken;
1264   const FormatToken *Previous = Current.getPreviousNonComment();
1265 
1266   // Don't add extra indentation for the first fake parenthesis after
1267   // 'return', assignments or opening <({[. The indentation for these cases
1268   // is special cased.
1269   bool SkipFirstExtraIndent =
1270       (Previous && (Previous->opensScope() ||
1271                     Previous->isOneOf(tok::semi, tok::kw_return) ||
1272                     (Previous->getPrecedence() == prec::Assignment &&
1273                      Style.AlignOperands) ||
1274                     Previous->is(TT_ObjCMethodExpr)));
1275   for (SmallVectorImpl<prec::Level>::const_reverse_iterator
1276            I = Current.FakeLParens.rbegin(),
1277            E = Current.FakeLParens.rend();
1278        I != E; ++I) {
1279     ParenState NewParenState = State.Stack.back();
1280     NewParenState.Tok = nullptr;
1281     NewParenState.ContainsLineBreak = false;
1282     NewParenState.LastOperatorWrapped = true;
1283     NewParenState.NoLineBreak =
1284         NewParenState.NoLineBreak || State.Stack.back().NoLineBreakInOperand;
1285 
1286     // Don't propagate AvoidBinPacking into subexpressions of arg/param lists.
1287     if (*I > prec::Comma)
1288       NewParenState.AvoidBinPacking = false;
1289 
1290     // Indent from 'LastSpace' unless these are fake parentheses encapsulating
1291     // a builder type call after 'return' or, if the alignment after opening
1292     // brackets is disabled.
1293     if (!Current.isTrailingComment() &&
1294         (Style.AlignOperands || *I < prec::Assignment) &&
1295         (!Previous || Previous->isNot(tok::kw_return) ||
1296          (Style.Language != FormatStyle::LK_Java && *I > 0)) &&
1297         (Style.AlignAfterOpenBracket != FormatStyle::BAS_DontAlign ||
1298          *I != prec::Comma || Current.NestingLevel == 0))
1299       NewParenState.Indent =
1300           std::max(std::max(State.Column, NewParenState.Indent),
1301                    State.Stack.back().LastSpace);
1302 
1303     // Do not indent relative to the fake parentheses inserted for "." or "->".
1304     // This is a special case to make the following to statements consistent:
1305     //   OuterFunction(InnerFunctionCall( // break
1306     //       ParameterToInnerFunction));
1307     //   OuterFunction(SomeObject.InnerFunctionCall( // break
1308     //       ParameterToInnerFunction));
1309     if (*I > prec::Unknown)
1310       NewParenState.LastSpace = std::max(NewParenState.LastSpace, State.Column);
1311     if (*I != prec::Conditional && !Current.is(TT_UnaryOperator) &&
1312         Style.AlignAfterOpenBracket != FormatStyle::BAS_DontAlign)
1313       NewParenState.StartOfFunctionCall = State.Column;
1314 
1315     // Always indent conditional expressions. Never indent expression where
1316     // the 'operator' is ',', ';' or an assignment (i.e. *I <=
1317     // prec::Assignment) as those have different indentation rules. Indent
1318     // other expression, unless the indentation needs to be skipped.
1319     if (*I == prec::Conditional ||
1320         (!SkipFirstExtraIndent && *I > prec::Assignment &&
1321          !Current.isTrailingComment()))
1322       NewParenState.Indent += Style.ContinuationIndentWidth;
1323     if ((Previous && !Previous->opensScope()) || *I != prec::Comma)
1324       NewParenState.BreakBeforeParameter = false;
1325     State.Stack.push_back(NewParenState);
1326     SkipFirstExtraIndent = false;
1327   }
1328 }
1329 
1330 void ContinuationIndenter::moveStatePastFakeRParens(LineState &State) {
1331   for (unsigned i = 0, e = State.NextToken->FakeRParens; i != e; ++i) {
1332     unsigned VariablePos = State.Stack.back().VariablePos;
1333     if (State.Stack.size() == 1) {
1334       // Do not pop the last element.
1335       break;
1336     }
1337     State.Stack.pop_back();
1338     State.Stack.back().VariablePos = VariablePos;
1339   }
1340 }
1341 
1342 void ContinuationIndenter::moveStatePastScopeOpener(LineState &State,
1343                                                     bool Newline) {
1344   const FormatToken &Current = *State.NextToken;
1345   if (!Current.opensScope())
1346     return;
1347 
1348   // Don't allow '<' or '(' in C# generic type constraints to start new scopes.
1349   if (Current.isOneOf(tok::less, tok::l_paren) &&
1350       State.Stack.back().IsCSharpGenericTypeConstraint)
1351     return;
1352 
1353   if (Current.MatchingParen && Current.BlockKind == BK_Block) {
1354     moveStateToNewBlock(State);
1355     return;
1356   }
1357 
1358   unsigned NewIndent;
1359   unsigned LastSpace = State.Stack.back().LastSpace;
1360   bool AvoidBinPacking;
1361   bool BreakBeforeParameter = false;
1362   unsigned NestedBlockIndent = std::max(State.Stack.back().StartOfFunctionCall,
1363                                         State.Stack.back().NestedBlockIndent);
1364   if (Current.isOneOf(tok::l_brace, TT_ArrayInitializerLSquare) ||
1365       opensProtoMessageField(Current, Style)) {
1366     if (Current.opensBlockOrBlockTypeList(Style)) {
1367       NewIndent = Style.IndentWidth +
1368                   std::min(State.Column, State.Stack.back().NestedBlockIndent);
1369     } else {
1370       NewIndent = State.Stack.back().LastSpace + Style.ContinuationIndentWidth;
1371     }
1372     const FormatToken *NextNoComment = Current.getNextNonComment();
1373     bool EndsInComma = Current.MatchingParen &&
1374                        Current.MatchingParen->Previous &&
1375                        Current.MatchingParen->Previous->is(tok::comma);
1376     AvoidBinPacking = EndsInComma || Current.is(TT_DictLiteral) ||
1377                       Style.Language == FormatStyle::LK_Proto ||
1378                       Style.Language == FormatStyle::LK_TextProto ||
1379                       !Style.BinPackArguments ||
1380                       (NextNoComment &&
1381                        NextNoComment->isOneOf(TT_DesignatedInitializerPeriod,
1382                                               TT_DesignatedInitializerLSquare));
1383     BreakBeforeParameter = EndsInComma;
1384     if (Current.ParameterCount > 1)
1385       NestedBlockIndent = std::max(NestedBlockIndent, State.Column + 1);
1386   } else {
1387     NewIndent = Style.ContinuationIndentWidth +
1388                 std::max(State.Stack.back().LastSpace,
1389                          State.Stack.back().StartOfFunctionCall);
1390 
1391     // Ensure that different different brackets force relative alignment, e.g.:
1392     // void SomeFunction(vector<  // break
1393     //                       int> v);
1394     // FIXME: We likely want to do this for more combinations of brackets.
1395     if (Current.is(tok::less) && Current.ParentBracket == tok::l_paren) {
1396       NewIndent = std::max(NewIndent, State.Stack.back().Indent);
1397       LastSpace = std::max(LastSpace, State.Stack.back().Indent);
1398     }
1399 
1400     bool EndsInComma =
1401         Current.MatchingParen &&
1402         Current.MatchingParen->getPreviousNonComment() &&
1403         Current.MatchingParen->getPreviousNonComment()->is(tok::comma);
1404 
1405     // If ObjCBinPackProtocolList is unspecified, fall back to BinPackParameters
1406     // for backwards compatibility.
1407     bool ObjCBinPackProtocolList =
1408         (Style.ObjCBinPackProtocolList == FormatStyle::BPS_Auto &&
1409          Style.BinPackParameters) ||
1410         Style.ObjCBinPackProtocolList == FormatStyle::BPS_Always;
1411 
1412     bool BinPackDeclaration =
1413         (State.Line->Type != LT_ObjCDecl && Style.BinPackParameters) ||
1414         (State.Line->Type == LT_ObjCDecl && ObjCBinPackProtocolList);
1415 
1416     AvoidBinPacking =
1417         (State.Stack.back().IsCSharpGenericTypeConstraint) ||
1418         (Style.Language == FormatStyle::LK_JavaScript && EndsInComma) ||
1419         (State.Line->MustBeDeclaration && !BinPackDeclaration) ||
1420         (!State.Line->MustBeDeclaration && !Style.BinPackArguments) ||
1421         (Style.ExperimentalAutoDetectBinPacking &&
1422          (Current.PackingKind == PPK_OnePerLine ||
1423           (!BinPackInconclusiveFunctions &&
1424            Current.PackingKind == PPK_Inconclusive)));
1425 
1426     if (Current.is(TT_ObjCMethodExpr) && Current.MatchingParen &&
1427         Style.ObjCBreakBeforeNestedBlockParam) {
1428       if (Style.ColumnLimit) {
1429         // If this '[' opens an ObjC call, determine whether all parameters fit
1430         // into one line and put one per line if they don't.
1431         if (getLengthToMatchingParen(Current, State.Stack) + State.Column >
1432             getColumnLimit(State))
1433           BreakBeforeParameter = true;
1434       } else {
1435         // For ColumnLimit = 0, we have to figure out whether there is or has to
1436         // be a line break within this call.
1437         for (const FormatToken *Tok = &Current;
1438              Tok && Tok != Current.MatchingParen; Tok = Tok->Next) {
1439           if (Tok->MustBreakBefore ||
1440               (Tok->CanBreakBefore && Tok->NewlinesBefore > 0)) {
1441             BreakBeforeParameter = true;
1442             break;
1443           }
1444         }
1445       }
1446     }
1447 
1448     if (Style.Language == FormatStyle::LK_JavaScript && EndsInComma)
1449       BreakBeforeParameter = true;
1450   }
1451   // Generally inherit NoLineBreak from the current scope to nested scope.
1452   // However, don't do this for non-empty nested blocks, dict literals and
1453   // array literals as these follow different indentation rules.
1454   bool NoLineBreak =
1455       Current.Children.empty() &&
1456       !Current.isOneOf(TT_DictLiteral, TT_ArrayInitializerLSquare) &&
1457       (State.Stack.back().NoLineBreak ||
1458        State.Stack.back().NoLineBreakInOperand ||
1459        (Current.is(TT_TemplateOpener) &&
1460         State.Stack.back().ContainsUnwrappedBuilder));
1461   State.Stack.push_back(
1462       ParenState(&Current, NewIndent, LastSpace, AvoidBinPacking, NoLineBreak));
1463   State.Stack.back().NestedBlockIndent = NestedBlockIndent;
1464   State.Stack.back().BreakBeforeParameter = BreakBeforeParameter;
1465   State.Stack.back().HasMultipleNestedBlocks = (Current.BlockParameterCount > 1);
1466 
1467   if (Style.BraceWrapping.BeforeLambdaBody &&
1468       Current.Next != nullptr && Current.Tok.is(tok::l_paren)) {
1469     // Search for any parameter that is a lambda
1470     FormatToken const *next = Current.Next;
1471     while (next != nullptr) {
1472       if (next->is(TT_LambdaLSquare)) {
1473         State.Stack.back().HasMultipleNestedBlocks = true;
1474         break;
1475       }
1476       next = next->Next;
1477     }
1478   }
1479 
1480   State.Stack.back().IsInsideObjCArrayLiteral =
1481       Current.is(TT_ArrayInitializerLSquare) && Current.Previous &&
1482       Current.Previous->is(tok::at);
1483 }
1484 
1485 void ContinuationIndenter::moveStatePastScopeCloser(LineState &State) {
1486   const FormatToken &Current = *State.NextToken;
1487   if (!Current.closesScope())
1488     return;
1489 
1490   // If we encounter a closing ), ], } or >, we can remove a level from our
1491   // stacks.
1492   if (State.Stack.size() > 1 &&
1493       (Current.isOneOf(tok::r_paren, tok::r_square, TT_TemplateString) ||
1494        (Current.is(tok::r_brace) && State.NextToken != State.Line->First) ||
1495        State.NextToken->is(TT_TemplateCloser) ||
1496        (Current.is(tok::greater) && Current.is(TT_DictLiteral))))
1497     State.Stack.pop_back();
1498 
1499   // Reevaluate whether ObjC message arguments fit into one line.
1500   // If a receiver spans multiple lines, e.g.:
1501   //   [[object block:^{
1502   //     return 42;
1503   //   }] a:42 b:42];
1504   // BreakBeforeParameter is calculated based on an incorrect assumption
1505   // (it is checked whether the whole expression fits into one line without
1506   // considering a line break inside a message receiver).
1507   // We check whether arguements fit after receiver scope closer (into the same
1508   // line).
1509   if (State.Stack.back().BreakBeforeParameter && Current.MatchingParen &&
1510       Current.MatchingParen->Previous) {
1511     const FormatToken &CurrentScopeOpener = *Current.MatchingParen->Previous;
1512     if (CurrentScopeOpener.is(TT_ObjCMethodExpr) &&
1513         CurrentScopeOpener.MatchingParen) {
1514       int NecessarySpaceInLine =
1515           getLengthToMatchingParen(CurrentScopeOpener, State.Stack) +
1516           CurrentScopeOpener.TotalLength - Current.TotalLength - 1;
1517       if (State.Column + Current.ColumnWidth + NecessarySpaceInLine <=
1518           Style.ColumnLimit)
1519         State.Stack.back().BreakBeforeParameter = false;
1520     }
1521   }
1522 
1523   if (Current.is(tok::r_square)) {
1524     // If this ends the array subscript expr, reset the corresponding value.
1525     const FormatToken *NextNonComment = Current.getNextNonComment();
1526     if (NextNonComment && NextNonComment->isNot(tok::l_square))
1527       State.Stack.back().StartOfArraySubscripts = 0;
1528   }
1529 }
1530 
1531 void ContinuationIndenter::moveStateToNewBlock(LineState &State) {
1532   unsigned NestedBlockIndent = State.Stack.back().NestedBlockIndent;
1533   // ObjC block sometimes follow special indentation rules.
1534   unsigned NewIndent =
1535       NestedBlockIndent + (State.NextToken->is(TT_ObjCBlockLBrace)
1536                                ? Style.ObjCBlockIndentWidth
1537                                : Style.IndentWidth);
1538   State.Stack.push_back(ParenState(State.NextToken, NewIndent,
1539                                    State.Stack.back().LastSpace,
1540                                    /*AvoidBinPacking=*/true,
1541                                    /*NoLineBreak=*/false));
1542   State.Stack.back().NestedBlockIndent = NestedBlockIndent;
1543   State.Stack.back().BreakBeforeParameter = true;
1544 }
1545 
1546 static unsigned getLastLineEndColumn(StringRef Text, unsigned StartColumn,
1547                                      unsigned TabWidth,
1548                                      encoding::Encoding Encoding) {
1549   size_t LastNewlinePos = Text.find_last_of("\n");
1550   if (LastNewlinePos == StringRef::npos) {
1551     return StartColumn +
1552            encoding::columnWidthWithTabs(Text, StartColumn, TabWidth, Encoding);
1553   } else {
1554     return encoding::columnWidthWithTabs(Text.substr(LastNewlinePos),
1555                                          /*StartColumn=*/0, TabWidth, Encoding);
1556   }
1557 }
1558 
1559 unsigned ContinuationIndenter::reformatRawStringLiteral(
1560     const FormatToken &Current, LineState &State,
1561     const FormatStyle &RawStringStyle, bool DryRun, bool Newline) {
1562   unsigned StartColumn = State.Column - Current.ColumnWidth;
1563   StringRef OldDelimiter = *getRawStringDelimiter(Current.TokenText);
1564   StringRef NewDelimiter =
1565       getCanonicalRawStringDelimiter(Style, RawStringStyle.Language);
1566   if (NewDelimiter.empty() || OldDelimiter.empty())
1567     NewDelimiter = OldDelimiter;
1568   // The text of a raw string is between the leading 'R"delimiter(' and the
1569   // trailing 'delimiter)"'.
1570   unsigned OldPrefixSize = 3 + OldDelimiter.size();
1571   unsigned OldSuffixSize = 2 + OldDelimiter.size();
1572   // We create a virtual text environment which expects a null-terminated
1573   // string, so we cannot use StringRef.
1574   std::string RawText = std::string(
1575       Current.TokenText.substr(OldPrefixSize).drop_back(OldSuffixSize));
1576   if (NewDelimiter != OldDelimiter) {
1577     // Don't update to the canonical delimiter 'deli' if ')deli"' occurs in the
1578     // raw string.
1579     std::string CanonicalDelimiterSuffix = (")" + NewDelimiter + "\"").str();
1580     if (StringRef(RawText).contains(CanonicalDelimiterSuffix))
1581       NewDelimiter = OldDelimiter;
1582   }
1583 
1584   unsigned NewPrefixSize = 3 + NewDelimiter.size();
1585   unsigned NewSuffixSize = 2 + NewDelimiter.size();
1586 
1587   // The first start column is the column the raw text starts after formatting.
1588   unsigned FirstStartColumn = StartColumn + NewPrefixSize;
1589 
1590   // The next start column is the intended indentation a line break inside
1591   // the raw string at level 0. It is determined by the following rules:
1592   //   - if the content starts on newline, it is one level more than the current
1593   //     indent, and
1594   //   - if the content does not start on a newline, it is the first start
1595   //     column.
1596   // These rules have the advantage that the formatted content both does not
1597   // violate the rectangle rule and visually flows within the surrounding
1598   // source.
1599   bool ContentStartsOnNewline = Current.TokenText[OldPrefixSize] == '\n';
1600   // If this token is the last parameter (checked by looking if it's followed by
1601   // `)` and is not on a newline, the base the indent off the line's nested
1602   // block indent. Otherwise, base the indent off the arguments indent, so we
1603   // can achieve:
1604   //
1605   // fffffffffff(1, 2, 3, R"pb(
1606   //     key1: 1  #
1607   //     key2: 2)pb");
1608   //
1609   // fffffffffff(1, 2, 3,
1610   //             R"pb(
1611   //               key1: 1  #
1612   //               key2: 2
1613   //             )pb");
1614   //
1615   // fffffffffff(1, 2, 3,
1616   //             R"pb(
1617   //               key1: 1  #
1618   //               key2: 2
1619   //             )pb",
1620   //             5);
1621   unsigned CurrentIndent =
1622       (!Newline && Current.Next && Current.Next->is(tok::r_paren))
1623           ? State.Stack.back().NestedBlockIndent
1624           : State.Stack.back().Indent;
1625   unsigned NextStartColumn = ContentStartsOnNewline
1626                                  ? CurrentIndent + Style.IndentWidth
1627                                  : FirstStartColumn;
1628 
1629   // The last start column is the column the raw string suffix starts if it is
1630   // put on a newline.
1631   // The last start column is the intended indentation of the raw string postfix
1632   // if it is put on a newline. It is determined by the following rules:
1633   //   - if the raw string prefix starts on a newline, it is the column where
1634   //     that raw string prefix starts, and
1635   //   - if the raw string prefix does not start on a newline, it is the current
1636   //     indent.
1637   unsigned LastStartColumn =
1638       Current.NewlinesBefore ? FirstStartColumn - NewPrefixSize : CurrentIndent;
1639 
1640   std::pair<tooling::Replacements, unsigned> Fixes = internal::reformat(
1641       RawStringStyle, RawText, {tooling::Range(0, RawText.size())},
1642       FirstStartColumn, NextStartColumn, LastStartColumn, "<stdin>",
1643       /*Status=*/nullptr);
1644 
1645   auto NewCode = applyAllReplacements(RawText, Fixes.first);
1646   tooling::Replacements NoFixes;
1647   if (!NewCode) {
1648     return addMultilineToken(Current, State);
1649   }
1650   if (!DryRun) {
1651     if (NewDelimiter != OldDelimiter) {
1652       // In 'R"delimiter(...', the delimiter starts 2 characters after the start
1653       // of the token.
1654       SourceLocation PrefixDelimiterStart =
1655           Current.Tok.getLocation().getLocWithOffset(2);
1656       auto PrefixErr = Whitespaces.addReplacement(tooling::Replacement(
1657           SourceMgr, PrefixDelimiterStart, OldDelimiter.size(), NewDelimiter));
1658       if (PrefixErr) {
1659         llvm::errs()
1660             << "Failed to update the prefix delimiter of a raw string: "
1661             << llvm::toString(std::move(PrefixErr)) << "\n";
1662       }
1663       // In 'R"delimiter(...)delimiter"', the suffix delimiter starts at
1664       // position length - 1 - |delimiter|.
1665       SourceLocation SuffixDelimiterStart =
1666           Current.Tok.getLocation().getLocWithOffset(Current.TokenText.size() -
1667                                                      1 - OldDelimiter.size());
1668       auto SuffixErr = Whitespaces.addReplacement(tooling::Replacement(
1669           SourceMgr, SuffixDelimiterStart, OldDelimiter.size(), NewDelimiter));
1670       if (SuffixErr) {
1671         llvm::errs()
1672             << "Failed to update the suffix delimiter of a raw string: "
1673             << llvm::toString(std::move(SuffixErr)) << "\n";
1674       }
1675     }
1676     SourceLocation OriginLoc =
1677         Current.Tok.getLocation().getLocWithOffset(OldPrefixSize);
1678     for (const tooling::Replacement &Fix : Fixes.first) {
1679       auto Err = Whitespaces.addReplacement(tooling::Replacement(
1680           SourceMgr, OriginLoc.getLocWithOffset(Fix.getOffset()),
1681           Fix.getLength(), Fix.getReplacementText()));
1682       if (Err) {
1683         llvm::errs() << "Failed to reformat raw string: "
1684                      << llvm::toString(std::move(Err)) << "\n";
1685       }
1686     }
1687   }
1688   unsigned RawLastLineEndColumn = getLastLineEndColumn(
1689       *NewCode, FirstStartColumn, Style.TabWidth, Encoding);
1690   State.Column = RawLastLineEndColumn + NewSuffixSize;
1691   // Since we're updating the column to after the raw string literal here, we
1692   // have to manually add the penalty for the prefix R"delim( over the column
1693   // limit.
1694   unsigned PrefixExcessCharacters =
1695       StartColumn + NewPrefixSize > Style.ColumnLimit
1696           ? StartColumn + NewPrefixSize - Style.ColumnLimit
1697           : 0;
1698   bool IsMultiline =
1699       ContentStartsOnNewline || (NewCode->find('\n') != std::string::npos);
1700   if (IsMultiline) {
1701     // Break before further function parameters on all levels.
1702     for (unsigned i = 0, e = State.Stack.size(); i != e; ++i)
1703       State.Stack[i].BreakBeforeParameter = true;
1704   }
1705   return Fixes.second + PrefixExcessCharacters * Style.PenaltyExcessCharacter;
1706 }
1707 
1708 unsigned ContinuationIndenter::addMultilineToken(const FormatToken &Current,
1709                                                  LineState &State) {
1710   // Break before further function parameters on all levels.
1711   for (unsigned i = 0, e = State.Stack.size(); i != e; ++i)
1712     State.Stack[i].BreakBeforeParameter = true;
1713 
1714   unsigned ColumnsUsed = State.Column;
1715   // We can only affect layout of the first and the last line, so the penalty
1716   // for all other lines is constant, and we ignore it.
1717   State.Column = Current.LastLineColumnWidth;
1718 
1719   if (ColumnsUsed > getColumnLimit(State))
1720     return Style.PenaltyExcessCharacter * (ColumnsUsed - getColumnLimit(State));
1721   return 0;
1722 }
1723 
1724 unsigned ContinuationIndenter::handleEndOfLine(const FormatToken &Current,
1725                                                LineState &State, bool DryRun,
1726                                                bool AllowBreak, bool Newline) {
1727   unsigned Penalty = 0;
1728   // Compute the raw string style to use in case this is a raw string literal
1729   // that can be reformatted.
1730   auto RawStringStyle = getRawStringStyle(Current, State);
1731   if (RawStringStyle && !Current.Finalized) {
1732     Penalty = reformatRawStringLiteral(Current, State, *RawStringStyle, DryRun,
1733                                        Newline);
1734   } else if (Current.IsMultiline && Current.isNot(TT_BlockComment)) {
1735     // Don't break multi-line tokens other than block comments and raw string
1736     // literals. Instead, just update the state.
1737     Penalty = addMultilineToken(Current, State);
1738   } else if (State.Line->Type != LT_ImportStatement) {
1739     // We generally don't break import statements.
1740     LineState OriginalState = State;
1741 
1742     // Whether we force the reflowing algorithm to stay strictly within the
1743     // column limit.
1744     bool Strict = false;
1745     // Whether the first non-strict attempt at reflowing did intentionally
1746     // exceed the column limit.
1747     bool Exceeded = false;
1748     std::tie(Penalty, Exceeded) = breakProtrudingToken(
1749         Current, State, AllowBreak, /*DryRun=*/true, Strict);
1750     if (Exceeded) {
1751       // If non-strict reflowing exceeds the column limit, try whether strict
1752       // reflowing leads to an overall lower penalty.
1753       LineState StrictState = OriginalState;
1754       unsigned StrictPenalty =
1755           breakProtrudingToken(Current, StrictState, AllowBreak,
1756                                /*DryRun=*/true, /*Strict=*/true)
1757               .first;
1758       Strict = StrictPenalty <= Penalty;
1759       if (Strict) {
1760         Penalty = StrictPenalty;
1761         State = StrictState;
1762       }
1763     }
1764     if (!DryRun) {
1765       // If we're not in dry-run mode, apply the changes with the decision on
1766       // strictness made above.
1767       breakProtrudingToken(Current, OriginalState, AllowBreak, /*DryRun=*/false,
1768                            Strict);
1769     }
1770   }
1771   if (State.Column > getColumnLimit(State)) {
1772     unsigned ExcessCharacters = State.Column - getColumnLimit(State);
1773     Penalty += Style.PenaltyExcessCharacter * ExcessCharacters;
1774   }
1775   return Penalty;
1776 }
1777 
1778 // Returns the enclosing function name of a token, or the empty string if not
1779 // found.
1780 static StringRef getEnclosingFunctionName(const FormatToken &Current) {
1781   // Look for: 'function(' or 'function<templates>(' before Current.
1782   auto Tok = Current.getPreviousNonComment();
1783   if (!Tok || !Tok->is(tok::l_paren))
1784     return "";
1785   Tok = Tok->getPreviousNonComment();
1786   if (!Tok)
1787     return "";
1788   if (Tok->is(TT_TemplateCloser)) {
1789     Tok = Tok->MatchingParen;
1790     if (Tok)
1791       Tok = Tok->getPreviousNonComment();
1792   }
1793   if (!Tok || !Tok->is(tok::identifier))
1794     return "";
1795   return Tok->TokenText;
1796 }
1797 
1798 llvm::Optional<FormatStyle>
1799 ContinuationIndenter::getRawStringStyle(const FormatToken &Current,
1800                                         const LineState &State) {
1801   if (!Current.isStringLiteral())
1802     return None;
1803   auto Delimiter = getRawStringDelimiter(Current.TokenText);
1804   if (!Delimiter)
1805     return None;
1806   auto RawStringStyle = RawStringFormats.getDelimiterStyle(*Delimiter);
1807   if (!RawStringStyle && Delimiter->empty())
1808     RawStringStyle = RawStringFormats.getEnclosingFunctionStyle(
1809         getEnclosingFunctionName(Current));
1810   if (!RawStringStyle)
1811     return None;
1812   RawStringStyle->ColumnLimit = getColumnLimit(State);
1813   return RawStringStyle;
1814 }
1815 
1816 std::unique_ptr<BreakableToken>
1817 ContinuationIndenter::createBreakableToken(const FormatToken &Current,
1818                                            LineState &State, bool AllowBreak) {
1819   unsigned StartColumn = State.Column - Current.ColumnWidth;
1820   if (Current.isStringLiteral()) {
1821     // FIXME: String literal breaking is currently disabled for C#, Java and
1822     // JavaScript, as it requires strings to be merged using "+" which we
1823     // don't support.
1824     if (Style.Language == FormatStyle::LK_Java ||
1825         Style.Language == FormatStyle::LK_JavaScript || Style.isCSharp() ||
1826         !Style.BreakStringLiterals || !AllowBreak)
1827       return nullptr;
1828 
1829     // Don't break string literals inside preprocessor directives (except for
1830     // #define directives, as their contents are stored in separate lines and
1831     // are not affected by this check).
1832     // This way we avoid breaking code with line directives and unknown
1833     // preprocessor directives that contain long string literals.
1834     if (State.Line->Type == LT_PreprocessorDirective)
1835       return nullptr;
1836     // Exempts unterminated string literals from line breaking. The user will
1837     // likely want to terminate the string before any line breaking is done.
1838     if (Current.IsUnterminatedLiteral)
1839       return nullptr;
1840     // Don't break string literals inside Objective-C array literals (doing so
1841     // raises the warning -Wobjc-string-concatenation).
1842     if (State.Stack.back().IsInsideObjCArrayLiteral) {
1843       return nullptr;
1844     }
1845 
1846     StringRef Text = Current.TokenText;
1847     StringRef Prefix;
1848     StringRef Postfix;
1849     // FIXME: Handle whitespace between '_T', '(', '"..."', and ')'.
1850     // FIXME: Store Prefix and Suffix (or PrefixLength and SuffixLength to
1851     // reduce the overhead) for each FormatToken, which is a string, so that we
1852     // don't run multiple checks here on the hot path.
1853     if ((Text.endswith(Postfix = "\"") &&
1854          (Text.startswith(Prefix = "@\"") || Text.startswith(Prefix = "\"") ||
1855           Text.startswith(Prefix = "u\"") || Text.startswith(Prefix = "U\"") ||
1856           Text.startswith(Prefix = "u8\"") ||
1857           Text.startswith(Prefix = "L\""))) ||
1858         (Text.startswith(Prefix = "_T(\"") && Text.endswith(Postfix = "\")"))) {
1859       // We need this to address the case where there is an unbreakable tail
1860       // only if certain other formatting decisions have been taken. The
1861       // UnbreakableTailLength of Current is an overapproximation is that case
1862       // and we need to be correct here.
1863       unsigned UnbreakableTailLength = (State.NextToken && canBreak(State))
1864                                            ? 0
1865                                            : Current.UnbreakableTailLength;
1866       return std::make_unique<BreakableStringLiteral>(
1867           Current, StartColumn, Prefix, Postfix, UnbreakableTailLength,
1868           State.Line->InPPDirective, Encoding, Style);
1869     }
1870   } else if (Current.is(TT_BlockComment)) {
1871     if (!Style.ReflowComments ||
1872         // If a comment token switches formatting, like
1873         // /* clang-format on */, we don't want to break it further,
1874         // but we may still want to adjust its indentation.
1875         switchesFormatting(Current)) {
1876       return nullptr;
1877     }
1878     return std::make_unique<BreakableBlockComment>(
1879         Current, StartColumn, Current.OriginalColumn, !Current.Previous,
1880         State.Line->InPPDirective, Encoding, Style, Whitespaces.useCRLF());
1881   } else if (Current.is(TT_LineComment) &&
1882              (Current.Previous == nullptr ||
1883               Current.Previous->isNot(TT_ImplicitStringLiteral))) {
1884     if (!Style.ReflowComments ||
1885         CommentPragmasRegex.match(Current.TokenText.substr(2)) ||
1886         switchesFormatting(Current))
1887       return nullptr;
1888     return std::make_unique<BreakableLineCommentSection>(
1889         Current, StartColumn, Current.OriginalColumn, !Current.Previous,
1890         /*InPPDirective=*/false, Encoding, Style);
1891   }
1892   return nullptr;
1893 }
1894 
1895 std::pair<unsigned, bool>
1896 ContinuationIndenter::breakProtrudingToken(const FormatToken &Current,
1897                                            LineState &State, bool AllowBreak,
1898                                            bool DryRun, bool Strict) {
1899   std::unique_ptr<const BreakableToken> Token =
1900       createBreakableToken(Current, State, AllowBreak);
1901   if (!Token)
1902     return {0, false};
1903   assert(Token->getLineCount() > 0);
1904   unsigned ColumnLimit = getColumnLimit(State);
1905   if (Current.is(TT_LineComment)) {
1906     // We don't insert backslashes when breaking line comments.
1907     ColumnLimit = Style.ColumnLimit;
1908   }
1909   if (Current.UnbreakableTailLength >= ColumnLimit)
1910     return {0, false};
1911   // ColumnWidth was already accounted into State.Column before calling
1912   // breakProtrudingToken.
1913   unsigned StartColumn = State.Column - Current.ColumnWidth;
1914   unsigned NewBreakPenalty = Current.isStringLiteral()
1915                                  ? Style.PenaltyBreakString
1916                                  : Style.PenaltyBreakComment;
1917   // Stores whether we intentionally decide to let a line exceed the column
1918   // limit.
1919   bool Exceeded = false;
1920   // Stores whether we introduce a break anywhere in the token.
1921   bool BreakInserted = Token->introducesBreakBeforeToken();
1922   // Store whether we inserted a new line break at the end of the previous
1923   // logical line.
1924   bool NewBreakBefore = false;
1925   // We use a conservative reflowing strategy. Reflow starts after a line is
1926   // broken or the corresponding whitespace compressed. Reflow ends as soon as a
1927   // line that doesn't get reflown with the previous line is reached.
1928   bool Reflow = false;
1929   // Keep track of where we are in the token:
1930   // Where we are in the content of the current logical line.
1931   unsigned TailOffset = 0;
1932   // The column number we're currently at.
1933   unsigned ContentStartColumn =
1934       Token->getContentStartColumn(0, /*Break=*/false);
1935   // The number of columns left in the current logical line after TailOffset.
1936   unsigned RemainingTokenColumns =
1937       Token->getRemainingLength(0, TailOffset, ContentStartColumn);
1938   // Adapt the start of the token, for example indent.
1939   if (!DryRun)
1940     Token->adaptStartOfLine(0, Whitespaces);
1941 
1942   unsigned ContentIndent = 0;
1943   unsigned Penalty = 0;
1944   LLVM_DEBUG(llvm::dbgs() << "Breaking protruding token at column "
1945                           << StartColumn << ".\n");
1946   for (unsigned LineIndex = 0, EndIndex = Token->getLineCount();
1947        LineIndex != EndIndex; ++LineIndex) {
1948     LLVM_DEBUG(llvm::dbgs()
1949                << "  Line: " << LineIndex << " (Reflow: " << Reflow << ")\n");
1950     NewBreakBefore = false;
1951     // If we did reflow the previous line, we'll try reflowing again. Otherwise
1952     // we'll start reflowing if the current line is broken or whitespace is
1953     // compressed.
1954     bool TryReflow = Reflow;
1955     // Break the current token until we can fit the rest of the line.
1956     while (ContentStartColumn + RemainingTokenColumns > ColumnLimit) {
1957       LLVM_DEBUG(llvm::dbgs() << "    Over limit, need: "
1958                               << (ContentStartColumn + RemainingTokenColumns)
1959                               << ", space: " << ColumnLimit
1960                               << ", reflown prefix: " << ContentStartColumn
1961                               << ", offset in line: " << TailOffset << "\n");
1962       // If the current token doesn't fit, find the latest possible split in the
1963       // current line so that breaking at it will be under the column limit.
1964       // FIXME: Use the earliest possible split while reflowing to correctly
1965       // compress whitespace within a line.
1966       BreakableToken::Split Split =
1967           Token->getSplit(LineIndex, TailOffset, ColumnLimit,
1968                           ContentStartColumn, CommentPragmasRegex);
1969       if (Split.first == StringRef::npos) {
1970         // No break opportunity - update the penalty and continue with the next
1971         // logical line.
1972         if (LineIndex < EndIndex - 1)
1973           // The last line's penalty is handled in addNextStateToQueue() or when
1974           // calling replaceWhitespaceAfterLastLine below.
1975           Penalty += Style.PenaltyExcessCharacter *
1976                      (ContentStartColumn + RemainingTokenColumns - ColumnLimit);
1977         LLVM_DEBUG(llvm::dbgs() << "    No break opportunity.\n");
1978         break;
1979       }
1980       assert(Split.first != 0);
1981 
1982       if (Token->supportsReflow()) {
1983         // Check whether the next natural split point after the current one can
1984         // still fit the line, either because we can compress away whitespace,
1985         // or because the penalty the excess characters introduce is lower than
1986         // the break penalty.
1987         // We only do this for tokens that support reflowing, and thus allow us
1988         // to change the whitespace arbitrarily (e.g. comments).
1989         // Other tokens, like string literals, can be broken on arbitrary
1990         // positions.
1991 
1992         // First, compute the columns from TailOffset to the next possible split
1993         // position.
1994         // For example:
1995         // ColumnLimit:     |
1996         // // Some text   that    breaks
1997         //    ^ tail offset
1998         //             ^-- split
1999         //    ^-------- to split columns
2000         //                    ^--- next split
2001         //    ^--------------- to next split columns
2002         unsigned ToSplitColumns = Token->getRangeLength(
2003             LineIndex, TailOffset, Split.first, ContentStartColumn);
2004         LLVM_DEBUG(llvm::dbgs() << "    ToSplit: " << ToSplitColumns << "\n");
2005 
2006         BreakableToken::Split NextSplit = Token->getSplit(
2007             LineIndex, TailOffset + Split.first + Split.second, ColumnLimit,
2008             ContentStartColumn + ToSplitColumns + 1, CommentPragmasRegex);
2009         // Compute the columns necessary to fit the next non-breakable sequence
2010         // into the current line.
2011         unsigned ToNextSplitColumns = 0;
2012         if (NextSplit.first == StringRef::npos) {
2013           ToNextSplitColumns = Token->getRemainingLength(LineIndex, TailOffset,
2014                                                          ContentStartColumn);
2015         } else {
2016           ToNextSplitColumns = Token->getRangeLength(
2017               LineIndex, TailOffset,
2018               Split.first + Split.second + NextSplit.first, ContentStartColumn);
2019         }
2020         // Compress the whitespace between the break and the start of the next
2021         // unbreakable sequence.
2022         ToNextSplitColumns =
2023             Token->getLengthAfterCompression(ToNextSplitColumns, Split);
2024         LLVM_DEBUG(llvm::dbgs()
2025                    << "    ContentStartColumn: " << ContentStartColumn << "\n");
2026         LLVM_DEBUG(llvm::dbgs()
2027                    << "    ToNextSplit: " << ToNextSplitColumns << "\n");
2028         // If the whitespace compression makes us fit, continue on the current
2029         // line.
2030         bool ContinueOnLine =
2031             ContentStartColumn + ToNextSplitColumns <= ColumnLimit;
2032         unsigned ExcessCharactersPenalty = 0;
2033         if (!ContinueOnLine && !Strict) {
2034           // Similarly, if the excess characters' penalty is lower than the
2035           // penalty of introducing a new break, continue on the current line.
2036           ExcessCharactersPenalty =
2037               (ContentStartColumn + ToNextSplitColumns - ColumnLimit) *
2038               Style.PenaltyExcessCharacter;
2039           LLVM_DEBUG(llvm::dbgs()
2040                      << "    Penalty excess: " << ExcessCharactersPenalty
2041                      << "\n            break : " << NewBreakPenalty << "\n");
2042           if (ExcessCharactersPenalty < NewBreakPenalty) {
2043             Exceeded = true;
2044             ContinueOnLine = true;
2045           }
2046         }
2047         if (ContinueOnLine) {
2048           LLVM_DEBUG(llvm::dbgs() << "    Continuing on line...\n");
2049           // The current line fits after compressing the whitespace - reflow
2050           // the next line into it if possible.
2051           TryReflow = true;
2052           if (!DryRun)
2053             Token->compressWhitespace(LineIndex, TailOffset, Split,
2054                                       Whitespaces);
2055           // When we continue on the same line, leave one space between content.
2056           ContentStartColumn += ToSplitColumns + 1;
2057           Penalty += ExcessCharactersPenalty;
2058           TailOffset += Split.first + Split.second;
2059           RemainingTokenColumns = Token->getRemainingLength(
2060               LineIndex, TailOffset, ContentStartColumn);
2061           continue;
2062         }
2063       }
2064       LLVM_DEBUG(llvm::dbgs() << "    Breaking...\n");
2065       // Update the ContentIndent only if the current line was not reflown with
2066       // the previous line, since in that case the previous line should still
2067       // determine the ContentIndent. Also never intent the last line.
2068       if (!Reflow)
2069         ContentIndent = Token->getContentIndent(LineIndex);
2070       LLVM_DEBUG(llvm::dbgs()
2071                  << "    ContentIndent: " << ContentIndent << "\n");
2072       ContentStartColumn = ContentIndent + Token->getContentStartColumn(
2073                                                LineIndex, /*Break=*/true);
2074 
2075       unsigned NewRemainingTokenColumns = Token->getRemainingLength(
2076           LineIndex, TailOffset + Split.first + Split.second,
2077           ContentStartColumn);
2078       if (NewRemainingTokenColumns == 0) {
2079         // No content to indent.
2080         ContentIndent = 0;
2081         ContentStartColumn =
2082             Token->getContentStartColumn(LineIndex, /*Break=*/true);
2083         NewRemainingTokenColumns = Token->getRemainingLength(
2084             LineIndex, TailOffset + Split.first + Split.second,
2085             ContentStartColumn);
2086       }
2087 
2088       // When breaking before a tab character, it may be moved by a few columns,
2089       // but will still be expanded to the next tab stop, so we don't save any
2090       // columns.
2091       if (NewRemainingTokenColumns == RemainingTokenColumns) {
2092         // FIXME: Do we need to adjust the penalty?
2093         break;
2094       }
2095       assert(NewRemainingTokenColumns < RemainingTokenColumns);
2096 
2097       LLVM_DEBUG(llvm::dbgs() << "    Breaking at: " << TailOffset + Split.first
2098                               << ", " << Split.second << "\n");
2099       if (!DryRun)
2100         Token->insertBreak(LineIndex, TailOffset, Split, ContentIndent,
2101                            Whitespaces);
2102 
2103       Penalty += NewBreakPenalty;
2104       TailOffset += Split.first + Split.second;
2105       RemainingTokenColumns = NewRemainingTokenColumns;
2106       BreakInserted = true;
2107       NewBreakBefore = true;
2108     }
2109     // In case there's another line, prepare the state for the start of the next
2110     // line.
2111     if (LineIndex + 1 != EndIndex) {
2112       unsigned NextLineIndex = LineIndex + 1;
2113       if (NewBreakBefore)
2114         // After breaking a line, try to reflow the next line into the current
2115         // one once RemainingTokenColumns fits.
2116         TryReflow = true;
2117       if (TryReflow) {
2118         // We decided that we want to try reflowing the next line into the
2119         // current one.
2120         // We will now adjust the state as if the reflow is successful (in
2121         // preparation for the next line), and see whether that works. If we
2122         // decide that we cannot reflow, we will later reset the state to the
2123         // start of the next line.
2124         Reflow = false;
2125         // As we did not continue breaking the line, RemainingTokenColumns is
2126         // known to fit after ContentStartColumn. Adapt ContentStartColumn to
2127         // the position at which we want to format the next line if we do
2128         // actually reflow.
2129         // When we reflow, we need to add a space between the end of the current
2130         // line and the next line's start column.
2131         ContentStartColumn += RemainingTokenColumns + 1;
2132         // Get the split that we need to reflow next logical line into the end
2133         // of the current one; the split will include any leading whitespace of
2134         // the next logical line.
2135         BreakableToken::Split SplitBeforeNext =
2136             Token->getReflowSplit(NextLineIndex, CommentPragmasRegex);
2137         LLVM_DEBUG(llvm::dbgs()
2138                    << "    Size of reflown text: " << ContentStartColumn
2139                    << "\n    Potential reflow split: ");
2140         if (SplitBeforeNext.first != StringRef::npos) {
2141           LLVM_DEBUG(llvm::dbgs() << SplitBeforeNext.first << ", "
2142                                   << SplitBeforeNext.second << "\n");
2143           TailOffset = SplitBeforeNext.first + SplitBeforeNext.second;
2144           // If the rest of the next line fits into the current line below the
2145           // column limit, we can safely reflow.
2146           RemainingTokenColumns = Token->getRemainingLength(
2147               NextLineIndex, TailOffset, ContentStartColumn);
2148           Reflow = true;
2149           if (ContentStartColumn + RemainingTokenColumns > ColumnLimit) {
2150             LLVM_DEBUG(llvm::dbgs()
2151                        << "    Over limit after reflow, need: "
2152                        << (ContentStartColumn + RemainingTokenColumns)
2153                        << ", space: " << ColumnLimit
2154                        << ", reflown prefix: " << ContentStartColumn
2155                        << ", offset in line: " << TailOffset << "\n");
2156             // If the whole next line does not fit, try to find a point in
2157             // the next line at which we can break so that attaching the part
2158             // of the next line to that break point onto the current line is
2159             // below the column limit.
2160             BreakableToken::Split Split =
2161                 Token->getSplit(NextLineIndex, TailOffset, ColumnLimit,
2162                                 ContentStartColumn, CommentPragmasRegex);
2163             if (Split.first == StringRef::npos) {
2164               LLVM_DEBUG(llvm::dbgs() << "    Did not find later break\n");
2165               Reflow = false;
2166             } else {
2167               // Check whether the first split point gets us below the column
2168               // limit. Note that we will execute this split below as part of
2169               // the normal token breaking and reflow logic within the line.
2170               unsigned ToSplitColumns = Token->getRangeLength(
2171                   NextLineIndex, TailOffset, Split.first, ContentStartColumn);
2172               if (ContentStartColumn + ToSplitColumns > ColumnLimit) {
2173                 LLVM_DEBUG(llvm::dbgs() << "    Next split protrudes, need: "
2174                                         << (ContentStartColumn + ToSplitColumns)
2175                                         << ", space: " << ColumnLimit);
2176                 unsigned ExcessCharactersPenalty =
2177                     (ContentStartColumn + ToSplitColumns - ColumnLimit) *
2178                     Style.PenaltyExcessCharacter;
2179                 if (NewBreakPenalty < ExcessCharactersPenalty) {
2180                   Reflow = false;
2181                 }
2182               }
2183             }
2184           }
2185         } else {
2186           LLVM_DEBUG(llvm::dbgs() << "not found.\n");
2187         }
2188       }
2189       if (!Reflow) {
2190         // If we didn't reflow into the next line, the only space to consider is
2191         // the next logical line. Reset our state to match the start of the next
2192         // line.
2193         TailOffset = 0;
2194         ContentStartColumn =
2195             Token->getContentStartColumn(NextLineIndex, /*Break=*/false);
2196         RemainingTokenColumns = Token->getRemainingLength(
2197             NextLineIndex, TailOffset, ContentStartColumn);
2198         // Adapt the start of the token, for example indent.
2199         if (!DryRun)
2200           Token->adaptStartOfLine(NextLineIndex, Whitespaces);
2201       } else {
2202         // If we found a reflow split and have added a new break before the next
2203         // line, we are going to remove the line break at the start of the next
2204         // logical line. For example, here we'll add a new line break after
2205         // 'text', and subsequently delete the line break between 'that' and
2206         // 'reflows'.
2207         //   // some text that
2208         //   // reflows
2209         // ->
2210         //   // some text
2211         //   // that reflows
2212         // When adding the line break, we also added the penalty for it, so we
2213         // need to subtract that penalty again when we remove the line break due
2214         // to reflowing.
2215         if (NewBreakBefore) {
2216           assert(Penalty >= NewBreakPenalty);
2217           Penalty -= NewBreakPenalty;
2218         }
2219         if (!DryRun)
2220           Token->reflow(NextLineIndex, Whitespaces);
2221       }
2222     }
2223   }
2224 
2225   BreakableToken::Split SplitAfterLastLine =
2226       Token->getSplitAfterLastLine(TailOffset);
2227   if (SplitAfterLastLine.first != StringRef::npos) {
2228     LLVM_DEBUG(llvm::dbgs() << "Replacing whitespace after last line.\n");
2229 
2230     // We add the last line's penalty here, since that line is going to be split
2231     // now.
2232     Penalty += Style.PenaltyExcessCharacter *
2233                (ContentStartColumn + RemainingTokenColumns - ColumnLimit);
2234 
2235     if (!DryRun)
2236       Token->replaceWhitespaceAfterLastLine(TailOffset, SplitAfterLastLine,
2237                                             Whitespaces);
2238     ContentStartColumn =
2239         Token->getContentStartColumn(Token->getLineCount() - 1, /*Break=*/true);
2240     RemainingTokenColumns = Token->getRemainingLength(
2241         Token->getLineCount() - 1,
2242         TailOffset + SplitAfterLastLine.first + SplitAfterLastLine.second,
2243         ContentStartColumn);
2244   }
2245 
2246   State.Column = ContentStartColumn + RemainingTokenColumns -
2247                  Current.UnbreakableTailLength;
2248 
2249   if (BreakInserted) {
2250     // If we break the token inside a parameter list, we need to break before
2251     // the next parameter on all levels, so that the next parameter is clearly
2252     // visible. Line comments already introduce a break.
2253     if (Current.isNot(TT_LineComment)) {
2254       for (unsigned i = 0, e = State.Stack.size(); i != e; ++i)
2255         State.Stack[i].BreakBeforeParameter = true;
2256     }
2257 
2258     if (Current.is(TT_BlockComment))
2259       State.NoContinuation = true;
2260 
2261     State.Stack.back().LastSpace = StartColumn;
2262   }
2263 
2264   Token->updateNextToken(State);
2265 
2266   return {Penalty, Exceeded};
2267 }
2268 
2269 unsigned ContinuationIndenter::getColumnLimit(const LineState &State) const {
2270   // In preprocessor directives reserve two chars for trailing " \"
2271   return Style.ColumnLimit - (State.Line->InPPDirective ? 2 : 0);
2272 }
2273 
2274 bool ContinuationIndenter::nextIsMultilineString(const LineState &State) {
2275   const FormatToken &Current = *State.NextToken;
2276   if (!Current.isStringLiteral() || Current.is(TT_ImplicitStringLiteral))
2277     return false;
2278   // We never consider raw string literals "multiline" for the purpose of
2279   // AlwaysBreakBeforeMultilineStrings implementation as they are special-cased
2280   // (see TokenAnnotator::mustBreakBefore().
2281   if (Current.TokenText.startswith("R\""))
2282     return false;
2283   if (Current.IsMultiline)
2284     return true;
2285   if (Current.getNextNonComment() &&
2286       Current.getNextNonComment()->isStringLiteral())
2287     return true; // Implicit concatenation.
2288   if (Style.ColumnLimit != 0 && Style.BreakStringLiterals &&
2289       State.Column + Current.ColumnWidth + Current.UnbreakableTailLength >
2290           Style.ColumnLimit)
2291     return true; // String will be split.
2292   return false;
2293 }
2294 
2295 } // namespace format
2296 } // namespace clang
2297