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