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.is(BK_BracedInit) &&
288       Previous.Previous &&
289       Previous.Previous->isOneOf(tok::l_brace, tok::l_paren, tok::comma))
290     return false;
291   // This prevents breaks like:
292   //   ...
293   //   SomeParameter, OtherParameter).DoSomething(
294   //   ...
295   // As they hide "DoSomething" and are generally bad for readability.
296   if (Previous.opensScope() && Previous.isNot(tok::l_brace) &&
297       State.LowestLevelOnLine < State.StartOfLineLevel &&
298       State.LowestLevelOnLine < Current.NestingLevel)
299     return false;
300   if (Current.isMemberAccess() && State.Stack.back().ContainsUnwrappedBuilder)
301     return false;
302 
303   // Don't create a 'hanging' indent if there are multiple blocks in a single
304   // statement.
305   if (Previous.is(tok::l_brace) && State.Stack.size() > 1 &&
306       State.Stack[State.Stack.size() - 2].NestedBlockInlined &&
307       State.Stack[State.Stack.size() - 2].HasMultipleNestedBlocks)
308     return false;
309 
310   // Don't break after very short return types (e.g. "void") as that is often
311   // unexpected.
312   if (Current.is(TT_FunctionDeclarationName) && State.Column < 6) {
313     if (Style.AlwaysBreakAfterReturnType == FormatStyle::RTBS_None)
314       return false;
315   }
316 
317   // If binary operators are moved to the next line (including commas for some
318   // styles of constructor initializers), that's always ok.
319   if (!Current.isOneOf(TT_BinaryOperator, tok::comma) &&
320       State.Stack.back().NoLineBreakInOperand)
321     return false;
322 
323   if (Previous.is(tok::l_square) && Previous.is(TT_ObjCMethodExpr))
324     return false;
325 
326   return !State.Stack.back().NoLineBreak;
327 }
328 
329 bool ContinuationIndenter::mustBreak(const LineState &State) {
330   const FormatToken &Current = *State.NextToken;
331   const FormatToken &Previous = *Current.Previous;
332   if (Style.BraceWrapping.BeforeLambdaBody && Current.CanBreakBefore &&
333       Current.is(TT_LambdaLBrace) && Previous.isNot(TT_LineComment)) {
334     auto LambdaBodyLength = getLengthToMatchingParen(Current, State.Stack);
335     return (LambdaBodyLength > getColumnLimit(State));
336   }
337   if (Current.MustBreakBefore || Current.is(TT_InlineASMColon))
338     return true;
339   if (State.Stack.back().BreakBeforeClosingBrace &&
340       Current.closesBlockOrBlockTypeList(Style))
341     return true;
342   if (Previous.is(tok::semi) && State.LineContainsContinuedForLoopSection)
343     return true;
344   if (Style.Language == FormatStyle::LK_ObjC &&
345       Style.ObjCBreakBeforeNestedBlockParam &&
346       Current.ObjCSelectorNameParts > 1 &&
347       Current.startsSequence(TT_SelectorName, tok::colon, tok::caret)) {
348     return true;
349   }
350   // Avoid producing inconsistent states by requiring breaks where they are not
351   // permitted for C# generic type constraints.
352   if (State.Stack.back().IsCSharpGenericTypeConstraint &&
353       Previous.isNot(TT_CSharpGenericTypeConstraintComma))
354     return false;
355   if ((startsNextParameter(Current, Style) || Previous.is(tok::semi) ||
356        (Previous.is(TT_TemplateCloser) && Current.is(TT_StartOfName) &&
357         Style.isCpp() &&
358         // FIXME: This is a temporary workaround for the case where clang-format
359         // sets BreakBeforeParameter to avoid bin packing and this creates a
360         // completely unnecessary line break after a template type that isn't
361         // line-wrapped.
362         (Previous.NestingLevel == 1 || Style.BinPackParameters)) ||
363        (Style.BreakBeforeTernaryOperators && Current.is(TT_ConditionalExpr) &&
364         Previous.isNot(tok::question)) ||
365        (!Style.BreakBeforeTernaryOperators &&
366         Previous.is(TT_ConditionalExpr))) &&
367       State.Stack.back().BreakBeforeParameter && !Current.isTrailingComment() &&
368       !Current.isOneOf(tok::r_paren, tok::r_brace))
369     return true;
370   if (State.Stack.back().IsChainedConditional &&
371       ((Style.BreakBeforeTernaryOperators && Current.is(TT_ConditionalExpr) &&
372         Current.is(tok::colon)) ||
373        (!Style.BreakBeforeTernaryOperators && Previous.is(TT_ConditionalExpr) &&
374         Previous.is(tok::colon))))
375     return true;
376   if (((Previous.is(TT_DictLiteral) && Previous.is(tok::l_brace)) ||
377        (Previous.is(TT_ArrayInitializerLSquare) &&
378         Previous.ParameterCount > 1) ||
379        opensProtoMessageField(Previous, Style)) &&
380       Style.ColumnLimit > 0 &&
381       getLengthToMatchingParen(Previous, State.Stack) + State.Column - 1 >
382           getColumnLimit(State))
383     return true;
384 
385   const FormatToken &BreakConstructorInitializersToken =
386       Style.BreakConstructorInitializers == FormatStyle::BCIS_AfterColon
387           ? Previous
388           : Current;
389   if (BreakConstructorInitializersToken.is(TT_CtorInitializerColon) &&
390       (State.Column + State.Line->Last->TotalLength - Previous.TotalLength >
391            getColumnLimit(State) ||
392        State.Stack.back().BreakBeforeParameter) &&
393       (Style.AllowShortFunctionsOnASingleLine != FormatStyle::SFS_All ||
394        Style.BreakConstructorInitializers != FormatStyle::BCIS_BeforeColon ||
395        Style.ColumnLimit != 0))
396     return true;
397 
398   if (Current.is(TT_ObjCMethodExpr) && !Previous.is(TT_SelectorName) &&
399       State.Line->startsWith(TT_ObjCMethodSpecifier))
400     return true;
401   if (Current.is(TT_SelectorName) && !Previous.is(tok::at) &&
402       State.Stack.back().ObjCSelectorNameFound &&
403       State.Stack.back().BreakBeforeParameter &&
404       (Style.ObjCBreakBeforeNestedBlockParam ||
405        !Current.startsSequence(TT_SelectorName, tok::colon, tok::caret)))
406     return true;
407 
408   unsigned NewLineColumn = getNewLineColumn(State);
409   if (Current.isMemberAccess() && Style.ColumnLimit != 0 &&
410       State.Column + getLengthToNextOperator(Current) > Style.ColumnLimit &&
411       (State.Column > NewLineColumn ||
412        Current.NestingLevel < State.StartOfLineLevel))
413     return true;
414 
415   if (startsSegmentOfBuilderTypeCall(Current) &&
416       (State.Stack.back().CallContinuation != 0 ||
417        State.Stack.back().BreakBeforeParameter) &&
418       // JavaScript is treated different here as there is a frequent pattern:
419       //   SomeFunction(function() {
420       //     ...
421       //   }.bind(...));
422       // FIXME: We should find a more generic solution to this problem.
423       !(State.Column <= NewLineColumn &&
424         Style.Language == FormatStyle::LK_JavaScript) &&
425       !(Previous.closesScopeAfterBlock() && State.Column <= NewLineColumn))
426     return true;
427 
428   // If the template declaration spans multiple lines, force wrap before the
429   // function/class declaration
430   if (Previous.ClosesTemplateDeclaration &&
431       State.Stack.back().BreakBeforeParameter && Current.CanBreakBefore)
432     return true;
433 
434   if (!State.Line->First->is(tok::kw_enum) && State.Column <= NewLineColumn)
435     return false;
436 
437   if (Style.AlwaysBreakBeforeMultilineStrings &&
438       (NewLineColumn == State.FirstIndent + Style.ContinuationIndentWidth ||
439        Previous.is(tok::comma) || Current.NestingLevel < 2) &&
440       !Previous.isOneOf(tok::kw_return, tok::lessless, tok::at,
441                         Keywords.kw_dollar) &&
442       !Previous.isOneOf(TT_InlineASMColon, TT_ConditionalExpr) &&
443       nextIsMultilineString(State))
444     return true;
445 
446   // Using CanBreakBefore here and below takes care of the decision whether the
447   // current style uses wrapping before or after operators for the given
448   // operator.
449   if (Previous.is(TT_BinaryOperator) && Current.CanBreakBefore) {
450     // If we need to break somewhere inside the LHS of a binary expression, we
451     // should also break after the operator. Otherwise, the formatting would
452     // hide the operator precedence, e.g. in:
453     //   if (aaaaaaaaaaaaaa ==
454     //           bbbbbbbbbbbbbb && c) {..
455     // For comparisons, we only apply this rule, if the LHS is a binary
456     // expression itself as otherwise, the line breaks seem superfluous.
457     // We need special cases for ">>" which we have split into two ">" while
458     // lexing in order to make template parsing easier.
459     bool IsComparison = (Previous.getPrecedence() == prec::Relational ||
460                          Previous.getPrecedence() == prec::Equality ||
461                          Previous.getPrecedence() == prec::Spaceship) &&
462                         Previous.Previous &&
463                         Previous.Previous->isNot(TT_BinaryOperator); // For >>.
464     bool LHSIsBinaryExpr =
465         Previous.Previous && Previous.Previous->EndsBinaryExpression;
466     if ((!IsComparison || LHSIsBinaryExpr) && !Current.isTrailingComment() &&
467         Previous.getPrecedence() != prec::Assignment &&
468         State.Stack.back().BreakBeforeParameter)
469       return true;
470   } else if (Current.is(TT_BinaryOperator) && Current.CanBreakBefore &&
471              State.Stack.back().BreakBeforeParameter) {
472     return true;
473   }
474 
475   // Same as above, but for the first "<<" operator.
476   if (Current.is(tok::lessless) && Current.isNot(TT_OverloadedOperator) &&
477       State.Stack.back().BreakBeforeParameter &&
478       State.Stack.back().FirstLessLess == 0)
479     return true;
480 
481   if (Current.NestingLevel == 0 && !Current.isTrailingComment()) {
482     // Always break after "template <...>" and leading annotations. This is only
483     // for cases where the entire line does not fit on a single line as a
484     // different LineFormatter would be used otherwise.
485     if (Previous.ClosesTemplateDeclaration)
486       return Style.AlwaysBreakTemplateDeclarations != FormatStyle::BTDS_No;
487     if (Previous.is(TT_FunctionAnnotationRParen))
488       return true;
489     if (Previous.is(TT_LeadingJavaAnnotation) && Current.isNot(tok::l_paren) &&
490         Current.isNot(TT_LeadingJavaAnnotation))
491       return true;
492   }
493 
494   // If the return type spans multiple lines, wrap before the function name.
495   if (((Current.is(TT_FunctionDeclarationName) &&
496         // Don't break before a C# function when no break after return type
497         (!Style.isCSharp() ||
498          Style.AlwaysBreakAfterReturnType != FormatStyle::RTBS_None)) ||
499        (Current.is(tok::kw_operator) && !Previous.is(tok::coloncolon))) &&
500       !Previous.is(tok::kw_template) && State.Stack.back().BreakBeforeParameter)
501     return true;
502 
503   // The following could be precomputed as they do not depend on the state.
504   // However, as they should take effect only if the UnwrappedLine does not fit
505   // into the ColumnLimit, they are checked here in the ContinuationIndenter.
506   if (Style.ColumnLimit != 0 && Previous.is(BK_Block) &&
507       Previous.is(tok::l_brace) && !Current.isOneOf(tok::r_brace, tok::comment))
508     return true;
509 
510   if (Current.is(tok::lessless) &&
511       ((Previous.is(tok::identifier) && Previous.TokenText == "endl") ||
512        (Previous.Tok.isLiteral() && (Previous.TokenText.endswith("\\n\"") ||
513                                      Previous.TokenText == "\'\\n\'"))))
514     return true;
515 
516   if (Previous.is(TT_BlockComment) && Previous.IsMultiline)
517     return true;
518 
519   if (State.NoContinuation)
520     return true;
521 
522   return false;
523 }
524 
525 unsigned ContinuationIndenter::addTokenToState(LineState &State, bool Newline,
526                                                bool DryRun,
527                                                unsigned ExtraSpaces) {
528   const FormatToken &Current = *State.NextToken;
529 
530   assert(!State.Stack.empty());
531   State.NoContinuation = false;
532 
533   if ((Current.is(TT_ImplicitStringLiteral) &&
534        (Current.Previous->Tok.getIdentifierInfo() == nullptr ||
535         Current.Previous->Tok.getIdentifierInfo()->getPPKeywordID() ==
536             tok::pp_not_keyword))) {
537     unsigned EndColumn =
538         SourceMgr.getSpellingColumnNumber(Current.WhitespaceRange.getEnd());
539     if (Current.LastNewlineOffset != 0) {
540       // If there is a newline within this token, the final column will solely
541       // determined by the current end column.
542       State.Column = EndColumn;
543     } else {
544       unsigned StartColumn =
545           SourceMgr.getSpellingColumnNumber(Current.WhitespaceRange.getBegin());
546       assert(EndColumn >= StartColumn);
547       State.Column += EndColumn - StartColumn;
548     }
549     moveStateToNextToken(State, DryRun, /*Newline=*/false);
550     return 0;
551   }
552 
553   unsigned Penalty = 0;
554   if (Newline)
555     Penalty = addTokenOnNewLine(State, DryRun);
556   else
557     addTokenOnCurrentLine(State, DryRun, ExtraSpaces);
558 
559   return moveStateToNextToken(State, DryRun, Newline) + Penalty;
560 }
561 
562 void ContinuationIndenter::addTokenOnCurrentLine(LineState &State, bool DryRun,
563                                                  unsigned ExtraSpaces) {
564   FormatToken &Current = *State.NextToken;
565   const FormatToken &Previous = *State.NextToken->Previous;
566   if (Current.is(tok::equal) &&
567       (State.Line->First->is(tok::kw_for) || Current.NestingLevel == 0) &&
568       State.Stack.back().VariablePos == 0) {
569     State.Stack.back().VariablePos = State.Column;
570     // Move over * and & if they are bound to the variable name.
571     const FormatToken *Tok = &Previous;
572     while (Tok && State.Stack.back().VariablePos >= Tok->ColumnWidth) {
573       State.Stack.back().VariablePos -= Tok->ColumnWidth;
574       if (Tok->SpacesRequiredBefore != 0)
575         break;
576       Tok = Tok->Previous;
577     }
578     if (Previous.PartOfMultiVariableDeclStmt)
579       State.Stack.back().LastSpace = State.Stack.back().VariablePos;
580   }
581 
582   unsigned Spaces = Current.SpacesRequiredBefore + ExtraSpaces;
583 
584   // Indent preprocessor directives after the hash if required.
585   int PPColumnCorrection = 0;
586   if (Style.IndentPPDirectives == FormatStyle::PPDIS_AfterHash &&
587       Previous.is(tok::hash) && State.FirstIndent > 0 &&
588       (State.Line->Type == LT_PreprocessorDirective ||
589        State.Line->Type == LT_ImportStatement)) {
590     Spaces += State.FirstIndent;
591 
592     bool isPragmaLine =
593         State.Line->First->startsSequence(tok::hash, tok::pp_pragma);
594     // If indenting pragmas remove the extra space for the #.
595     if (Style.IndentPragmas && isPragmaLine)
596       Spaces--;
597 
598     // For preprocessor indent with tabs, State.Column will be 1 because of the
599     // hash. This causes second-level indents onward to have an extra space
600     // after the tabs. We avoid this misalignment by subtracting 1 from the
601     // column value passed to replaceWhitespace().
602     if (Style.UseTab != FormatStyle::UT_Never)
603       PPColumnCorrection = -1;
604   }
605 
606   if (!DryRun)
607     Whitespaces.replaceWhitespace(Current, /*Newlines=*/0, Spaces,
608                                   State.Column + Spaces + PPColumnCorrection);
609 
610   // If "BreakBeforeInheritanceComma" mode, don't break within the inheritance
611   // declaration unless there is multiple inheritance.
612   if (Style.BreakInheritanceList == FormatStyle::BILS_BeforeComma &&
613       Current.is(TT_InheritanceColon))
614     State.Stack.back().NoLineBreak = true;
615   if (Style.BreakInheritanceList == FormatStyle::BILS_AfterColon &&
616       Previous.is(TT_InheritanceColon))
617     State.Stack.back().NoLineBreak = true;
618 
619   if (Current.is(TT_SelectorName) &&
620       !State.Stack.back().ObjCSelectorNameFound) {
621     unsigned MinIndent =
622         std::max(State.FirstIndent + Style.ContinuationIndentWidth,
623                  State.Stack.back().Indent);
624     unsigned FirstColonPos = State.Column + Spaces + Current.ColumnWidth;
625     if (Current.LongestObjCSelectorName == 0)
626       State.Stack.back().AlignColons = false;
627     else if (MinIndent + Current.LongestObjCSelectorName > FirstColonPos)
628       State.Stack.back().ColonPos = MinIndent + Current.LongestObjCSelectorName;
629     else
630       State.Stack.back().ColonPos = FirstColonPos;
631   }
632 
633   // In "AlwaysBreak" mode, enforce wrapping directly after the parenthesis by
634   // disallowing any further line breaks if there is no line break after the
635   // opening parenthesis. Don't break if it doesn't conserve columns.
636   if (Style.AlignAfterOpenBracket == FormatStyle::BAS_AlwaysBreak &&
637       (Previous.isOneOf(tok::l_paren, TT_TemplateOpener, tok::l_square) ||
638        (Previous.is(tok::l_brace) && Previous.isNot(BK_Block) &&
639         Style.Cpp11BracedListStyle)) &&
640       State.Column > getNewLineColumn(State) &&
641       (!Previous.Previous || !Previous.Previous->isOneOf(
642                                  tok::kw_for, tok::kw_while, tok::kw_switch)) &&
643       // Don't do this for simple (no expressions) one-argument function calls
644       // as that feels like needlessly wasting whitespace, e.g.:
645       //
646       //   caaaaaaaaaaaall(
647       //       caaaaaaaaaaaall(
648       //           caaaaaaaaaaaall(
649       //               caaaaaaaaaaaaaaaaaaaaaaall(aaaaaaaaaaaaaa, aaaaaaaaa))));
650       Current.FakeLParens.size() > 0 &&
651       Current.FakeLParens.back() > prec::Unknown)
652     State.Stack.back().NoLineBreak = true;
653   if (Previous.is(TT_TemplateString) && Previous.opensScope())
654     State.Stack.back().NoLineBreak = true;
655 
656   if (Style.AlignAfterOpenBracket != FormatStyle::BAS_DontAlign &&
657       !State.Stack.back().IsCSharpGenericTypeConstraint &&
658       Previous.opensScope() && Previous.isNot(TT_ObjCMethodExpr) &&
659       (Current.isNot(TT_LineComment) || Previous.is(BK_BracedInit))) {
660     State.Stack.back().Indent = State.Column + Spaces;
661     State.Stack.back().IsAligned = true;
662   }
663   if (State.Stack.back().AvoidBinPacking && startsNextParameter(Current, Style))
664     State.Stack.back().NoLineBreak = true;
665   if (startsSegmentOfBuilderTypeCall(Current) &&
666       State.Column > getNewLineColumn(State))
667     State.Stack.back().ContainsUnwrappedBuilder = true;
668 
669   if (Current.is(TT_LambdaArrow) && Style.Language == FormatStyle::LK_Java)
670     State.Stack.back().NoLineBreak = true;
671   if (Current.isMemberAccess() && Previous.is(tok::r_paren) &&
672       (Previous.MatchingParen &&
673        (Previous.TotalLength - Previous.MatchingParen->TotalLength > 10)))
674     // If there is a function call with long parameters, break before trailing
675     // calls. This prevents things like:
676     //   EXPECT_CALL(SomeLongParameter).Times(
677     //       2);
678     // We don't want to do this for short parameters as they can just be
679     // indexes.
680     State.Stack.back().NoLineBreak = true;
681 
682   // Don't allow the RHS of an operator to be split over multiple lines unless
683   // there is a line-break right after the operator.
684   // Exclude relational operators, as there, it is always more desirable to
685   // have the LHS 'left' of the RHS.
686   const FormatToken *P = Current.getPreviousNonComment();
687   if (!Current.is(tok::comment) && P &&
688       (P->isOneOf(TT_BinaryOperator, tok::comma) ||
689        (P->is(TT_ConditionalExpr) && P->is(tok::colon))) &&
690       !P->isOneOf(TT_OverloadedOperator, TT_CtorInitializerComma) &&
691       P->getPrecedence() != prec::Assignment &&
692       P->getPrecedence() != prec::Relational &&
693       P->getPrecedence() != prec::Spaceship) {
694     bool BreakBeforeOperator =
695         P->MustBreakBefore || P->is(tok::lessless) ||
696         (P->is(TT_BinaryOperator) &&
697          Style.BreakBeforeBinaryOperators != FormatStyle::BOS_None) ||
698         (P->is(TT_ConditionalExpr) && Style.BreakBeforeTernaryOperators);
699     // Don't do this if there are only two operands. In these cases, there is
700     // always a nice vertical separation between them and the extra line break
701     // does not help.
702     bool HasTwoOperands =
703         P->OperatorIndex == 0 && !P->NextOperator && !P->is(TT_ConditionalExpr);
704     if ((!BreakBeforeOperator &&
705          !(HasTwoOperands &&
706            Style.AlignOperands != FormatStyle::OAS_DontAlign)) ||
707         (!State.Stack.back().LastOperatorWrapped && BreakBeforeOperator))
708       State.Stack.back().NoLineBreakInOperand = true;
709   }
710 
711   State.Column += Spaces;
712   if (Current.isNot(tok::comment) && Previous.is(tok::l_paren) &&
713       Previous.Previous &&
714       (Previous.Previous->is(tok::kw_for) || Previous.Previous->isIf())) {
715     // Treat the condition inside an if as if it was a second function
716     // parameter, i.e. let nested calls have a continuation indent.
717     State.Stack.back().LastSpace = State.Column;
718     State.Stack.back().NestedBlockIndent = State.Column;
719   } else if (!Current.isOneOf(tok::comment, tok::caret) &&
720              ((Previous.is(tok::comma) &&
721                !Previous.is(TT_OverloadedOperator)) ||
722               (Previous.is(tok::colon) && Previous.is(TT_ObjCMethodExpr)))) {
723     State.Stack.back().LastSpace = State.Column;
724   } else if (Previous.is(TT_CtorInitializerColon) &&
725              Style.BreakConstructorInitializers ==
726                  FormatStyle::BCIS_AfterColon) {
727     State.Stack.back().Indent = State.Column;
728     State.Stack.back().LastSpace = State.Column;
729   } else if ((Previous.isOneOf(TT_BinaryOperator, TT_ConditionalExpr,
730                                TT_CtorInitializerColon)) &&
731              ((Previous.getPrecedence() != prec::Assignment &&
732                (Previous.isNot(tok::lessless) || Previous.OperatorIndex != 0 ||
733                 Previous.NextOperator)) ||
734               Current.StartsBinaryExpression)) {
735     // Indent relative to the RHS of the expression unless this is a simple
736     // assignment without binary expression on the RHS. Also indent relative to
737     // unary operators and the colons of constructor initializers.
738     if (Style.BreakBeforeBinaryOperators == FormatStyle::BOS_None)
739       State.Stack.back().LastSpace = State.Column;
740   } else if (Previous.is(TT_InheritanceColon)) {
741     State.Stack.back().Indent = State.Column;
742     State.Stack.back().LastSpace = State.Column;
743   } else if (Current.is(TT_CSharpGenericTypeConstraintColon)) {
744     State.Stack.back().ColonPos = State.Column;
745   } else if (Previous.opensScope()) {
746     // If a function has a trailing call, indent all parameters from the
747     // opening parenthesis. This avoids confusing indents like:
748     //   OuterFunction(InnerFunctionCall( // break
749     //       ParameterToInnerFunction))   // break
750     //       .SecondInnerFunctionCall();
751     bool HasTrailingCall = false;
752     if (Previous.MatchingParen) {
753       const FormatToken *Next = Previous.MatchingParen->getNextNonComment();
754       HasTrailingCall = Next && Next->isMemberAccess();
755     }
756     if (HasTrailingCall && State.Stack.size() > 1 &&
757         State.Stack[State.Stack.size() - 2].CallContinuation == 0)
758       State.Stack.back().LastSpace = State.Column;
759   }
760 }
761 
762 unsigned ContinuationIndenter::addTokenOnNewLine(LineState &State,
763                                                  bool DryRun) {
764   FormatToken &Current = *State.NextToken;
765   const FormatToken &Previous = *State.NextToken->Previous;
766 
767   // Extra penalty that needs to be added because of the way certain line
768   // breaks are chosen.
769   unsigned Penalty = 0;
770 
771   const FormatToken *PreviousNonComment = Current.getPreviousNonComment();
772   const FormatToken *NextNonComment = Previous.getNextNonComment();
773   if (!NextNonComment)
774     NextNonComment = &Current;
775   // The first line break on any NestingLevel causes an extra penalty in order
776   // prefer similar line breaks.
777   if (!State.Stack.back().ContainsLineBreak)
778     Penalty += 15;
779   State.Stack.back().ContainsLineBreak = true;
780 
781   Penalty += State.NextToken->SplitPenalty;
782 
783   // Breaking before the first "<<" is generally not desirable if the LHS is
784   // short. Also always add the penalty if the LHS is split over multiple lines
785   // to avoid unnecessary line breaks that just work around this penalty.
786   if (NextNonComment->is(tok::lessless) &&
787       State.Stack.back().FirstLessLess == 0 &&
788       (State.Column <= Style.ColumnLimit / 3 ||
789        State.Stack.back().BreakBeforeParameter))
790     Penalty += Style.PenaltyBreakFirstLessLess;
791 
792   State.Column = getNewLineColumn(State);
793 
794   // Add Penalty proportional to amount of whitespace away from FirstColumn
795   // This tends to penalize several lines that are far-right indented,
796   // and prefers a line-break prior to such a block, e.g:
797   //
798   // Constructor() :
799   //   member(value), looooooooooooooooong_member(
800   //                      looooooooooong_call(param_1, param_2, param_3))
801   // would then become
802   // Constructor() :
803   //   member(value),
804   //   looooooooooooooooong_member(
805   //       looooooooooong_call(param_1, param_2, param_3))
806   if (State.Column > State.FirstIndent)
807     Penalty +=
808         Style.PenaltyIndentedWhitespace * (State.Column - State.FirstIndent);
809 
810   // Indent nested blocks relative to this column, unless in a very specific
811   // JavaScript special case where:
812   //
813   //   var loooooong_name =
814   //       function() {
815   //     // code
816   //   }
817   //
818   // is common and should be formatted like a free-standing function. The same
819   // goes for wrapping before the lambda return type arrow.
820   if (!Current.is(TT_LambdaArrow) &&
821       (Style.Language != FormatStyle::LK_JavaScript ||
822        Current.NestingLevel != 0 || !PreviousNonComment ||
823        !PreviousNonComment->is(tok::equal) ||
824        !Current.isOneOf(Keywords.kw_async, Keywords.kw_function)))
825     State.Stack.back().NestedBlockIndent = State.Column;
826 
827   if (NextNonComment->isMemberAccess()) {
828     if (State.Stack.back().CallContinuation == 0)
829       State.Stack.back().CallContinuation = State.Column;
830   } else if (NextNonComment->is(TT_SelectorName)) {
831     if (!State.Stack.back().ObjCSelectorNameFound) {
832       if (NextNonComment->LongestObjCSelectorName == 0) {
833         State.Stack.back().AlignColons = false;
834       } else {
835         State.Stack.back().ColonPos =
836             (shouldIndentWrappedSelectorName(Style, State.Line->Type)
837                  ? std::max(State.Stack.back().Indent,
838                             State.FirstIndent + Style.ContinuationIndentWidth)
839                  : State.Stack.back().Indent) +
840             std::max(NextNonComment->LongestObjCSelectorName,
841                      NextNonComment->ColumnWidth);
842       }
843     } else if (State.Stack.back().AlignColons &&
844                State.Stack.back().ColonPos <= NextNonComment->ColumnWidth) {
845       State.Stack.back().ColonPos = State.Column + NextNonComment->ColumnWidth;
846     }
847   } else if (PreviousNonComment && PreviousNonComment->is(tok::colon) &&
848              PreviousNonComment->isOneOf(TT_ObjCMethodExpr, TT_DictLiteral)) {
849     // FIXME: This is hacky, find a better way. The problem is that in an ObjC
850     // method expression, the block should be aligned to the line starting it,
851     // e.g.:
852     //   [aaaaaaaaaaaaaaa aaaaaaaaa: \\ break for some reason
853     //                        ^(int *i) {
854     //                            // ...
855     //                        }];
856     // Thus, we set LastSpace of the next higher NestingLevel, to which we move
857     // when we consume all of the "}"'s FakeRParens at the "{".
858     if (State.Stack.size() > 1)
859       State.Stack[State.Stack.size() - 2].LastSpace =
860           std::max(State.Stack.back().LastSpace, State.Stack.back().Indent) +
861           Style.ContinuationIndentWidth;
862   }
863 
864   if ((PreviousNonComment &&
865        PreviousNonComment->isOneOf(tok::comma, tok::semi) &&
866        !State.Stack.back().AvoidBinPacking) ||
867       Previous.is(TT_BinaryOperator))
868     State.Stack.back().BreakBeforeParameter = false;
869   if (PreviousNonComment &&
870       PreviousNonComment->isOneOf(TT_TemplateCloser, TT_JavaAnnotation) &&
871       Current.NestingLevel == 0)
872     State.Stack.back().BreakBeforeParameter = false;
873   if (NextNonComment->is(tok::question) ||
874       (PreviousNonComment && PreviousNonComment->is(tok::question)))
875     State.Stack.back().BreakBeforeParameter = true;
876   if (Current.is(TT_BinaryOperator) && Current.CanBreakBefore)
877     State.Stack.back().BreakBeforeParameter = false;
878 
879   if (!DryRun) {
880     unsigned MaxEmptyLinesToKeep = Style.MaxEmptyLinesToKeep + 1;
881     if (Current.is(tok::r_brace) && Current.MatchingParen &&
882         // Only strip trailing empty lines for l_braces that have children, i.e.
883         // for function expressions (lambdas, arrows, etc).
884         !Current.MatchingParen->Children.empty()) {
885       // lambdas and arrow functions are expressions, thus their r_brace is not
886       // on its own line, and thus not covered by UnwrappedLineFormatter's logic
887       // about removing empty lines on closing blocks. Special case them here.
888       MaxEmptyLinesToKeep = 1;
889     }
890     unsigned Newlines =
891         std::max(1u, std::min(Current.NewlinesBefore, MaxEmptyLinesToKeep));
892     bool ContinuePPDirective =
893         State.Line->InPPDirective && State.Line->Type != LT_ImportStatement;
894     Whitespaces.replaceWhitespace(Current, Newlines, State.Column, State.Column,
895                                   State.Stack.back().IsAligned,
896                                   ContinuePPDirective);
897   }
898 
899   if (!Current.isTrailingComment())
900     State.Stack.back().LastSpace = State.Column;
901   if (Current.is(tok::lessless))
902     // If we are breaking before a "<<", we always want to indent relative to
903     // RHS. This is necessary only for "<<", as we special-case it and don't
904     // always indent relative to the RHS.
905     State.Stack.back().LastSpace += 3; // 3 -> width of "<< ".
906 
907   State.StartOfLineLevel = Current.NestingLevel;
908   State.LowestLevelOnLine = Current.NestingLevel;
909 
910   // Any break on this level means that the parent level has been broken
911   // and we need to avoid bin packing there.
912   bool NestedBlockSpecialCase =
913       (!Style.isCpp() && Current.is(tok::r_brace) && State.Stack.size() > 1 &&
914        State.Stack[State.Stack.size() - 2].NestedBlockInlined) ||
915       (Style.Language == FormatStyle::LK_ObjC && Current.is(tok::r_brace) &&
916        State.Stack.size() > 1 && !Style.ObjCBreakBeforeNestedBlockParam);
917   if (!NestedBlockSpecialCase)
918     for (unsigned i = 0, e = State.Stack.size() - 1; i != e; ++i)
919       State.Stack[i].BreakBeforeParameter = true;
920 
921   if (PreviousNonComment &&
922       !PreviousNonComment->isOneOf(tok::comma, tok::colon, tok::semi) &&
923       (PreviousNonComment->isNot(TT_TemplateCloser) ||
924        Current.NestingLevel != 0) &&
925       !PreviousNonComment->isOneOf(
926           TT_BinaryOperator, TT_FunctionAnnotationRParen, TT_JavaAnnotation,
927           TT_LeadingJavaAnnotation) &&
928       Current.isNot(TT_BinaryOperator) && !PreviousNonComment->opensScope())
929     State.Stack.back().BreakBeforeParameter = true;
930 
931   // If we break after { or the [ of an array initializer, we should also break
932   // before the corresponding } or ].
933   if (PreviousNonComment &&
934       (PreviousNonComment->isOneOf(tok::l_brace, TT_ArrayInitializerLSquare) ||
935        opensProtoMessageField(*PreviousNonComment, Style)))
936     State.Stack.back().BreakBeforeClosingBrace = true;
937 
938   if (State.Stack.back().AvoidBinPacking) {
939     // If we are breaking after '(', '{', '<', or this is the break after a ':'
940     // to start a member initializater list in a constructor, this should not
941     // be considered bin packing unless the relevant AllowAll option is false or
942     // this is a dict/object literal.
943     bool PreviousIsBreakingCtorInitializerColon =
944         Previous.is(TT_CtorInitializerColon) &&
945         Style.BreakConstructorInitializers == FormatStyle::BCIS_AfterColon;
946     if (!(Previous.isOneOf(tok::l_paren, tok::l_brace, TT_BinaryOperator) ||
947           PreviousIsBreakingCtorInitializerColon) ||
948         (!Style.AllowAllParametersOfDeclarationOnNextLine &&
949          State.Line->MustBeDeclaration) ||
950         (!Style.AllowAllArgumentsOnNextLine &&
951          !State.Line->MustBeDeclaration) ||
952         (!Style.AllowAllConstructorInitializersOnNextLine &&
953          PreviousIsBreakingCtorInitializerColon) ||
954         Previous.is(TT_DictLiteral))
955       State.Stack.back().BreakBeforeParameter = true;
956 
957     // If we are breaking after a ':' to start a member initializer list,
958     // and we allow all arguments on the next line, we should not break
959     // before the next parameter.
960     if (PreviousIsBreakingCtorInitializerColon &&
961         Style.AllowAllConstructorInitializersOnNextLine)
962       State.Stack.back().BreakBeforeParameter = false;
963   }
964 
965   return Penalty;
966 }
967 
968 unsigned ContinuationIndenter::getNewLineColumn(const LineState &State) {
969   if (!State.NextToken || !State.NextToken->Previous)
970     return 0;
971 
972   FormatToken &Current = *State.NextToken;
973 
974   if (State.Stack.back().IsCSharpGenericTypeConstraint &&
975       Current.isNot(TT_CSharpGenericTypeConstraint))
976     return State.Stack.back().ColonPos + 2;
977 
978   const FormatToken &Previous = *Current.Previous;
979   // If we are continuing an expression, we want to use the continuation indent.
980   unsigned ContinuationIndent =
981       std::max(State.Stack.back().LastSpace, State.Stack.back().Indent) +
982       Style.ContinuationIndentWidth;
983   const FormatToken *PreviousNonComment = Current.getPreviousNonComment();
984   const FormatToken *NextNonComment = Previous.getNextNonComment();
985   if (!NextNonComment)
986     NextNonComment = &Current;
987 
988   // Java specific bits.
989   if (Style.Language == FormatStyle::LK_Java &&
990       Current.isOneOf(Keywords.kw_implements, Keywords.kw_extends))
991     return std::max(State.Stack.back().LastSpace,
992                     State.Stack.back().Indent + Style.ContinuationIndentWidth);
993 
994   if (Style.BreakBeforeBraces == FormatStyle::BS_Whitesmiths &&
995       State.Line->First->is(tok::kw_enum))
996     return (Style.IndentWidth * State.Line->First->IndentLevel) +
997            Style.IndentWidth;
998 
999   if (NextNonComment->is(tok::l_brace) && NextNonComment->is(BK_Block))
1000     return Current.NestingLevel == 0 ? State.FirstIndent
1001                                      : State.Stack.back().Indent;
1002   if ((Current.isOneOf(tok::r_brace, tok::r_square) ||
1003        (Current.is(tok::greater) &&
1004         (Style.Language == FormatStyle::LK_Proto ||
1005          Style.Language == FormatStyle::LK_TextProto))) &&
1006       State.Stack.size() > 1) {
1007     if (Current.closesBlockOrBlockTypeList(Style))
1008       return State.Stack[State.Stack.size() - 2].NestedBlockIndent;
1009     if (Current.MatchingParen && Current.MatchingParen->is(BK_BracedInit))
1010       return State.Stack[State.Stack.size() - 2].LastSpace;
1011     return State.FirstIndent;
1012   }
1013   // Indent a closing parenthesis at the previous level if followed by a semi,
1014   // const, or opening brace. This allows indentations such as:
1015   //     foo(
1016   //       a,
1017   //     );
1018   //     int Foo::getter(
1019   //         //
1020   //     ) const {
1021   //       return foo;
1022   //     }
1023   //     function foo(
1024   //       a,
1025   //     ) {
1026   //       code(); //
1027   //     }
1028   if (Current.is(tok::r_paren) && State.Stack.size() > 1 &&
1029       (!Current.Next ||
1030        Current.Next->isOneOf(tok::semi, tok::kw_const, tok::l_brace)))
1031     return State.Stack[State.Stack.size() - 2].LastSpace;
1032   if (NextNonComment->is(TT_TemplateString) && NextNonComment->closesScope())
1033     return State.Stack[State.Stack.size() - 2].LastSpace;
1034   if (Current.is(tok::identifier) && Current.Next &&
1035       (Current.Next->is(TT_DictLiteral) ||
1036        ((Style.Language == FormatStyle::LK_Proto ||
1037          Style.Language == FormatStyle::LK_TextProto) &&
1038         Current.Next->isOneOf(tok::less, tok::l_brace))))
1039     return State.Stack.back().Indent;
1040   if (NextNonComment->is(TT_ObjCStringLiteral) &&
1041       State.StartOfStringLiteral != 0)
1042     return State.StartOfStringLiteral - 1;
1043   if (NextNonComment->isStringLiteral() && State.StartOfStringLiteral != 0)
1044     return State.StartOfStringLiteral;
1045   if (NextNonComment->is(tok::lessless) &&
1046       State.Stack.back().FirstLessLess != 0)
1047     return State.Stack.back().FirstLessLess;
1048   if (NextNonComment->isMemberAccess()) {
1049     if (State.Stack.back().CallContinuation == 0)
1050       return ContinuationIndent;
1051     return State.Stack.back().CallContinuation;
1052   }
1053   if (State.Stack.back().QuestionColumn != 0 &&
1054       ((NextNonComment->is(tok::colon) &&
1055         NextNonComment->is(TT_ConditionalExpr)) ||
1056        Previous.is(TT_ConditionalExpr))) {
1057     if (((NextNonComment->is(tok::colon) && NextNonComment->Next &&
1058           !NextNonComment->Next->FakeLParens.empty() &&
1059           NextNonComment->Next->FakeLParens.back() == prec::Conditional) ||
1060          (Previous.is(tok::colon) && !Current.FakeLParens.empty() &&
1061           Current.FakeLParens.back() == prec::Conditional)) &&
1062         !State.Stack.back().IsWrappedConditional) {
1063       // NOTE: we may tweak this slightly:
1064       //    * not remove the 'lead' ContinuationIndentWidth
1065       //    * always un-indent by the operator when
1066       //    BreakBeforeTernaryOperators=true
1067       unsigned Indent = State.Stack.back().Indent;
1068       if (Style.AlignOperands != FormatStyle::OAS_DontAlign) {
1069         Indent -= Style.ContinuationIndentWidth;
1070       }
1071       if (Style.BreakBeforeTernaryOperators &&
1072           State.Stack.back().UnindentOperator)
1073         Indent -= 2;
1074       return Indent;
1075     }
1076     return State.Stack.back().QuestionColumn;
1077   }
1078   if (Previous.is(tok::comma) && State.Stack.back().VariablePos != 0)
1079     return State.Stack.back().VariablePos;
1080   if ((PreviousNonComment &&
1081        (PreviousNonComment->ClosesTemplateDeclaration ||
1082         PreviousNonComment->isOneOf(
1083             TT_AttributeParen, TT_AttributeSquare, TT_FunctionAnnotationRParen,
1084             TT_JavaAnnotation, TT_LeadingJavaAnnotation))) ||
1085       (!Style.IndentWrappedFunctionNames &&
1086        NextNonComment->isOneOf(tok::kw_operator, TT_FunctionDeclarationName)))
1087     return std::max(State.Stack.back().LastSpace, State.Stack.back().Indent);
1088   if (NextNonComment->is(TT_SelectorName)) {
1089     if (!State.Stack.back().ObjCSelectorNameFound) {
1090       unsigned MinIndent = State.Stack.back().Indent;
1091       if (shouldIndentWrappedSelectorName(Style, State.Line->Type))
1092         MinIndent = std::max(MinIndent,
1093                              State.FirstIndent + Style.ContinuationIndentWidth);
1094       // If LongestObjCSelectorName is 0, we are indenting the first
1095       // part of an ObjC selector (or a selector component which is
1096       // not colon-aligned due to block formatting).
1097       //
1098       // Otherwise, we are indenting a subsequent part of an ObjC
1099       // selector which should be colon-aligned to the longest
1100       // component of the ObjC selector.
1101       //
1102       // In either case, we want to respect Style.IndentWrappedFunctionNames.
1103       return MinIndent +
1104              std::max(NextNonComment->LongestObjCSelectorName,
1105                       NextNonComment->ColumnWidth) -
1106              NextNonComment->ColumnWidth;
1107     }
1108     if (!State.Stack.back().AlignColons)
1109       return State.Stack.back().Indent;
1110     if (State.Stack.back().ColonPos > NextNonComment->ColumnWidth)
1111       return State.Stack.back().ColonPos - NextNonComment->ColumnWidth;
1112     return State.Stack.back().Indent;
1113   }
1114   if (NextNonComment->is(tok::colon) && NextNonComment->is(TT_ObjCMethodExpr))
1115     return State.Stack.back().ColonPos;
1116   if (NextNonComment->is(TT_ArraySubscriptLSquare)) {
1117     if (State.Stack.back().StartOfArraySubscripts != 0)
1118       return State.Stack.back().StartOfArraySubscripts;
1119     else if (Style.isCSharp()) // C# allows `["key"] = value` inside object
1120                                // initializers.
1121       return State.Stack.back().Indent;
1122     return ContinuationIndent;
1123   }
1124 
1125   // This ensure that we correctly format ObjC methods calls without inputs,
1126   // i.e. where the last element isn't selector like: [callee method];
1127   if (NextNonComment->is(tok::identifier) && NextNonComment->FakeRParens == 0 &&
1128       NextNonComment->Next && NextNonComment->Next->is(TT_ObjCMethodExpr))
1129     return State.Stack.back().Indent;
1130 
1131   if (NextNonComment->isOneOf(TT_StartOfName, TT_PointerOrReference) ||
1132       Previous.isOneOf(tok::coloncolon, tok::equal, TT_JsTypeColon))
1133     return ContinuationIndent;
1134   if (PreviousNonComment && PreviousNonComment->is(tok::colon) &&
1135       PreviousNonComment->isOneOf(TT_ObjCMethodExpr, TT_DictLiteral))
1136     return ContinuationIndent;
1137   if (NextNonComment->is(TT_CtorInitializerComma))
1138     return State.Stack.back().Indent;
1139   if (PreviousNonComment && PreviousNonComment->is(TT_CtorInitializerColon) &&
1140       Style.BreakConstructorInitializers == FormatStyle::BCIS_AfterColon)
1141     return State.Stack.back().Indent;
1142   if (PreviousNonComment && PreviousNonComment->is(TT_InheritanceColon) &&
1143       Style.BreakInheritanceList == FormatStyle::BILS_AfterColon)
1144     return State.Stack.back().Indent;
1145   if (NextNonComment->isOneOf(TT_CtorInitializerColon, TT_InheritanceColon,
1146                               TT_InheritanceComma))
1147     return State.FirstIndent + Style.ConstructorInitializerIndentWidth;
1148   if (Previous.is(tok::r_paren) && !Current.isBinaryOperator() &&
1149       !Current.isOneOf(tok::colon, tok::comment))
1150     return ContinuationIndent;
1151   if (Current.is(TT_ProtoExtensionLSquare))
1152     return State.Stack.back().Indent;
1153   if (Current.isBinaryOperator() && State.Stack.back().UnindentOperator)
1154     return State.Stack.back().Indent - Current.Tok.getLength() -
1155            Current.SpacesRequiredBefore;
1156   if (Current.isOneOf(tok::comment, TT_BlockComment, TT_LineComment) &&
1157       NextNonComment->isBinaryOperator() && State.Stack.back().UnindentOperator)
1158     return State.Stack.back().Indent - NextNonComment->Tok.getLength() -
1159            NextNonComment->SpacesRequiredBefore;
1160   if (State.Stack.back().Indent == State.FirstIndent && PreviousNonComment &&
1161       !PreviousNonComment->isOneOf(tok::r_brace, TT_CtorInitializerComma))
1162     // Ensure that we fall back to the continuation indent width instead of
1163     // just flushing continuations left.
1164     return State.Stack.back().Indent + Style.ContinuationIndentWidth;
1165   return State.Stack.back().Indent;
1166 }
1167 
1168 static bool hasNestedBlockInlined(const FormatToken *Previous,
1169                                   const FormatToken &Current,
1170                                   const FormatStyle &Style) {
1171   if (Previous->isNot(tok::l_paren))
1172     return true;
1173   if (Previous->ParameterCount > 1)
1174     return true;
1175 
1176   // Also a nested block if contains a lambda inside function with 1 parameter
1177   return (Style.BraceWrapping.BeforeLambdaBody && Current.is(TT_LambdaLSquare));
1178 }
1179 
1180 unsigned ContinuationIndenter::moveStateToNextToken(LineState &State,
1181                                                     bool DryRun, bool Newline) {
1182   assert(State.Stack.size());
1183   const FormatToken &Current = *State.NextToken;
1184 
1185   if (Current.is(TT_CSharpGenericTypeConstraint))
1186     State.Stack.back().IsCSharpGenericTypeConstraint = true;
1187   if (Current.isOneOf(tok::comma, TT_BinaryOperator))
1188     State.Stack.back().NoLineBreakInOperand = false;
1189   if (Current.isOneOf(TT_InheritanceColon, TT_CSharpGenericTypeConstraintColon))
1190     State.Stack.back().AvoidBinPacking = true;
1191   if (Current.is(tok::lessless) && Current.isNot(TT_OverloadedOperator)) {
1192     if (State.Stack.back().FirstLessLess == 0)
1193       State.Stack.back().FirstLessLess = State.Column;
1194     else
1195       State.Stack.back().LastOperatorWrapped = Newline;
1196   }
1197   if (Current.is(TT_BinaryOperator) && Current.isNot(tok::lessless))
1198     State.Stack.back().LastOperatorWrapped = Newline;
1199   if (Current.is(TT_ConditionalExpr) && Current.Previous &&
1200       !Current.Previous->is(TT_ConditionalExpr))
1201     State.Stack.back().LastOperatorWrapped = Newline;
1202   if (Current.is(TT_ArraySubscriptLSquare) &&
1203       State.Stack.back().StartOfArraySubscripts == 0)
1204     State.Stack.back().StartOfArraySubscripts = State.Column;
1205   if (Current.is(TT_ConditionalExpr) && Current.is(tok::question) &&
1206       ((Current.MustBreakBefore) ||
1207        (Current.getNextNonComment() &&
1208         Current.getNextNonComment()->MustBreakBefore)))
1209     State.Stack.back().IsWrappedConditional = true;
1210   if (Style.BreakBeforeTernaryOperators && Current.is(tok::question))
1211     State.Stack.back().QuestionColumn = State.Column;
1212   if (!Style.BreakBeforeTernaryOperators && Current.isNot(tok::colon)) {
1213     const FormatToken *Previous = Current.Previous;
1214     while (Previous && Previous->isTrailingComment())
1215       Previous = Previous->Previous;
1216     if (Previous && Previous->is(tok::question))
1217       State.Stack.back().QuestionColumn = State.Column;
1218   }
1219   if (!Current.opensScope() && !Current.closesScope() &&
1220       !Current.is(TT_PointerOrReference))
1221     State.LowestLevelOnLine =
1222         std::min(State.LowestLevelOnLine, Current.NestingLevel);
1223   if (Current.isMemberAccess())
1224     State.Stack.back().StartOfFunctionCall =
1225         !Current.NextOperator ? 0 : State.Column;
1226   if (Current.is(TT_SelectorName))
1227     State.Stack.back().ObjCSelectorNameFound = true;
1228   if (Current.is(TT_CtorInitializerColon) &&
1229       Style.BreakConstructorInitializers != FormatStyle::BCIS_AfterColon) {
1230     // Indent 2 from the column, so:
1231     // SomeClass::SomeClass()
1232     //     : First(...), ...
1233     //       Next(...)
1234     //       ^ line up here.
1235     State.Stack.back().Indent =
1236         State.Column +
1237         (Style.BreakConstructorInitializers == FormatStyle::BCIS_BeforeComma
1238              ? 0
1239              : 2);
1240     State.Stack.back().NestedBlockIndent = State.Stack.back().Indent;
1241     if (Style.ConstructorInitializerAllOnOneLineOrOnePerLine) {
1242       State.Stack.back().AvoidBinPacking = true;
1243       State.Stack.back().BreakBeforeParameter =
1244           !Style.AllowAllConstructorInitializersOnNextLine;
1245     } else {
1246       State.Stack.back().BreakBeforeParameter = false;
1247     }
1248   }
1249   if (Current.is(TT_CtorInitializerColon) &&
1250       Style.BreakConstructorInitializers == FormatStyle::BCIS_AfterColon) {
1251     State.Stack.back().Indent =
1252         State.FirstIndent + Style.ConstructorInitializerIndentWidth;
1253     State.Stack.back().NestedBlockIndent = State.Stack.back().Indent;
1254     if (Style.ConstructorInitializerAllOnOneLineOrOnePerLine)
1255       State.Stack.back().AvoidBinPacking = true;
1256   }
1257   if (Current.is(TT_InheritanceColon))
1258     State.Stack.back().Indent =
1259         State.FirstIndent + Style.ConstructorInitializerIndentWidth;
1260   if (Current.isOneOf(TT_BinaryOperator, TT_ConditionalExpr) && Newline)
1261     State.Stack.back().NestedBlockIndent =
1262         State.Column + Current.ColumnWidth + 1;
1263   if (Current.isOneOf(TT_LambdaLSquare, TT_LambdaArrow))
1264     State.Stack.back().LastSpace = State.Column;
1265 
1266   // Insert scopes created by fake parenthesis.
1267   const FormatToken *Previous = Current.getPreviousNonComment();
1268 
1269   // Add special behavior to support a format commonly used for JavaScript
1270   // closures:
1271   //   SomeFunction(function() {
1272   //     foo();
1273   //     bar();
1274   //   }, a, b, c);
1275   if (Current.isNot(tok::comment) && Previous &&
1276       Previous->isOneOf(tok::l_brace, TT_ArrayInitializerLSquare) &&
1277       !Previous->is(TT_DictLiteral) && State.Stack.size() > 1 &&
1278       !State.Stack.back().HasMultipleNestedBlocks) {
1279     if (State.Stack[State.Stack.size() - 2].NestedBlockInlined && Newline)
1280       for (unsigned i = 0, e = State.Stack.size() - 1; i != e; ++i)
1281         State.Stack[i].NoLineBreak = true;
1282     State.Stack[State.Stack.size() - 2].NestedBlockInlined = false;
1283   }
1284   if (Previous &&
1285       (Previous->isOneOf(tok::l_paren, tok::comma, tok::colon) ||
1286        Previous->isOneOf(TT_BinaryOperator, TT_ConditionalExpr)) &&
1287       !Previous->isOneOf(TT_DictLiteral, TT_ObjCMethodExpr)) {
1288     State.Stack.back().NestedBlockInlined =
1289         !Newline && hasNestedBlockInlined(Previous, Current, Style);
1290   }
1291 
1292   moveStatePastFakeLParens(State, Newline);
1293   moveStatePastScopeCloser(State);
1294   bool AllowBreak = !State.Stack.back().NoLineBreak &&
1295                     !State.Stack.back().NoLineBreakInOperand;
1296   moveStatePastScopeOpener(State, Newline);
1297   moveStatePastFakeRParens(State);
1298 
1299   if (Current.is(TT_ObjCStringLiteral) && State.StartOfStringLiteral == 0)
1300     State.StartOfStringLiteral = State.Column + 1;
1301   if (Current.is(TT_CSharpStringLiteral) && State.StartOfStringLiteral == 0)
1302     State.StartOfStringLiteral = State.Column + 1;
1303   else if (Current.isStringLiteral() && State.StartOfStringLiteral == 0)
1304     State.StartOfStringLiteral = State.Column;
1305   else if (!Current.isOneOf(tok::comment, tok::identifier, tok::hash) &&
1306            !Current.isStringLiteral())
1307     State.StartOfStringLiteral = 0;
1308 
1309   State.Column += Current.ColumnWidth;
1310   State.NextToken = State.NextToken->Next;
1311 
1312   unsigned Penalty =
1313       handleEndOfLine(Current, State, DryRun, AllowBreak, Newline);
1314 
1315   if (Current.Role)
1316     Current.Role->formatFromToken(State, this, DryRun);
1317   // If the previous has a special role, let it consume tokens as appropriate.
1318   // It is necessary to start at the previous token for the only implemented
1319   // role (comma separated list). That way, the decision whether or not to break
1320   // after the "{" is already done and both options are tried and evaluated.
1321   // FIXME: This is ugly, find a better way.
1322   if (Previous && Previous->Role)
1323     Penalty += Previous->Role->formatAfterToken(State, this, DryRun);
1324 
1325   return Penalty;
1326 }
1327 
1328 void ContinuationIndenter::moveStatePastFakeLParens(LineState &State,
1329                                                     bool Newline) {
1330   const FormatToken &Current = *State.NextToken;
1331   const FormatToken *Previous = Current.getPreviousNonComment();
1332 
1333   // Don't add extra indentation for the first fake parenthesis after
1334   // 'return', assignments or opening <({[. The indentation for these cases
1335   // is special cased.
1336   bool SkipFirstExtraIndent =
1337       (Previous && (Previous->opensScope() ||
1338                     Previous->isOneOf(tok::semi, tok::kw_return) ||
1339                     (Previous->getPrecedence() == prec::Assignment &&
1340                      Style.AlignOperands != FormatStyle::OAS_DontAlign) ||
1341                     Previous->is(TT_ObjCMethodExpr)));
1342   for (SmallVectorImpl<prec::Level>::const_reverse_iterator
1343            I = Current.FakeLParens.rbegin(),
1344            E = Current.FakeLParens.rend();
1345        I != E; ++I) {
1346     ParenState NewParenState = State.Stack.back();
1347     NewParenState.Tok = nullptr;
1348     NewParenState.ContainsLineBreak = false;
1349     NewParenState.LastOperatorWrapped = true;
1350     NewParenState.IsChainedConditional = false;
1351     NewParenState.IsWrappedConditional = false;
1352     NewParenState.UnindentOperator = false;
1353     NewParenState.NoLineBreak =
1354         NewParenState.NoLineBreak || State.Stack.back().NoLineBreakInOperand;
1355 
1356     // Don't propagate AvoidBinPacking into subexpressions of arg/param lists.
1357     if (*I > prec::Comma)
1358       NewParenState.AvoidBinPacking = false;
1359 
1360     // Indent from 'LastSpace' unless these are fake parentheses encapsulating
1361     // a builder type call after 'return' or, if the alignment after opening
1362     // brackets is disabled.
1363     if (!Current.isTrailingComment() &&
1364         (Style.AlignOperands != FormatStyle::OAS_DontAlign ||
1365          *I < prec::Assignment) &&
1366         (!Previous || Previous->isNot(tok::kw_return) ||
1367          (Style.Language != FormatStyle::LK_Java && *I > 0)) &&
1368         (Style.AlignAfterOpenBracket != FormatStyle::BAS_DontAlign ||
1369          *I != prec::Comma || Current.NestingLevel == 0)) {
1370       NewParenState.Indent =
1371           std::max(std::max(State.Column, NewParenState.Indent),
1372                    State.Stack.back().LastSpace);
1373     }
1374 
1375     if (Previous &&
1376         (Previous->getPrecedence() == prec::Assignment ||
1377          Previous->is(tok::kw_return) ||
1378          (*I == prec::Conditional && Previous->is(tok::question) &&
1379           Previous->is(TT_ConditionalExpr))) &&
1380         !Newline) {
1381       // If BreakBeforeBinaryOperators is set, un-indent a bit to account for
1382       // the operator and keep the operands aligned
1383       if (Style.AlignOperands == FormatStyle::OAS_AlignAfterOperator)
1384         NewParenState.UnindentOperator = true;
1385       // Mark indentation as alignment if the expression is aligned.
1386       if (Style.AlignOperands != FormatStyle::OAS_DontAlign)
1387         NewParenState.IsAligned = true;
1388     }
1389 
1390     // Do not indent relative to the fake parentheses inserted for "." or "->".
1391     // This is a special case to make the following to statements consistent:
1392     //   OuterFunction(InnerFunctionCall( // break
1393     //       ParameterToInnerFunction));
1394     //   OuterFunction(SomeObject.InnerFunctionCall( // break
1395     //       ParameterToInnerFunction));
1396     if (*I > prec::Unknown)
1397       NewParenState.LastSpace = std::max(NewParenState.LastSpace, State.Column);
1398     if (*I != prec::Conditional && !Current.is(TT_UnaryOperator) &&
1399         Style.AlignAfterOpenBracket != FormatStyle::BAS_DontAlign)
1400       NewParenState.StartOfFunctionCall = State.Column;
1401 
1402     // Indent conditional expressions, unless they are chained "else-if"
1403     // conditionals. Never indent expression where the 'operator' is ',', ';' or
1404     // an assignment (i.e. *I <= prec::Assignment) as those have different
1405     // indentation rules. Indent other expression, unless the indentation needs
1406     // to be skipped.
1407     if (*I == prec::Conditional && Previous && Previous->is(tok::colon) &&
1408         Previous->is(TT_ConditionalExpr) && I == Current.FakeLParens.rbegin() &&
1409         !State.Stack.back().IsWrappedConditional) {
1410       NewParenState.IsChainedConditional = true;
1411       NewParenState.UnindentOperator = State.Stack.back().UnindentOperator;
1412     } else if (*I == prec::Conditional ||
1413                (!SkipFirstExtraIndent && *I > prec::Assignment &&
1414                 !Current.isTrailingComment())) {
1415       NewParenState.Indent += Style.ContinuationIndentWidth;
1416     }
1417     if ((Previous && !Previous->opensScope()) || *I != prec::Comma)
1418       NewParenState.BreakBeforeParameter = false;
1419     State.Stack.push_back(NewParenState);
1420     SkipFirstExtraIndent = false;
1421   }
1422 }
1423 
1424 void ContinuationIndenter::moveStatePastFakeRParens(LineState &State) {
1425   for (unsigned i = 0, e = State.NextToken->FakeRParens; i != e; ++i) {
1426     unsigned VariablePos = State.Stack.back().VariablePos;
1427     if (State.Stack.size() == 1) {
1428       // Do not pop the last element.
1429       break;
1430     }
1431     State.Stack.pop_back();
1432     State.Stack.back().VariablePos = VariablePos;
1433   }
1434 }
1435 
1436 void ContinuationIndenter::moveStatePastScopeOpener(LineState &State,
1437                                                     bool Newline) {
1438   const FormatToken &Current = *State.NextToken;
1439   if (!Current.opensScope())
1440     return;
1441 
1442   // Don't allow '<' or '(' in C# generic type constraints to start new scopes.
1443   if (Current.isOneOf(tok::less, tok::l_paren) &&
1444       State.Stack.back().IsCSharpGenericTypeConstraint)
1445     return;
1446 
1447   if (Current.MatchingParen && Current.is(BK_Block)) {
1448     moveStateToNewBlock(State);
1449     return;
1450   }
1451 
1452   unsigned NewIndent;
1453   unsigned LastSpace = State.Stack.back().LastSpace;
1454   bool AvoidBinPacking;
1455   bool BreakBeforeParameter = false;
1456   unsigned NestedBlockIndent = std::max(State.Stack.back().StartOfFunctionCall,
1457                                         State.Stack.back().NestedBlockIndent);
1458   if (Current.isOneOf(tok::l_brace, TT_ArrayInitializerLSquare) ||
1459       opensProtoMessageField(Current, Style)) {
1460     if (Current.opensBlockOrBlockTypeList(Style)) {
1461       NewIndent = Style.IndentWidth +
1462                   std::min(State.Column, State.Stack.back().NestedBlockIndent);
1463     } else {
1464       NewIndent = State.Stack.back().LastSpace + Style.ContinuationIndentWidth;
1465     }
1466     const FormatToken *NextNoComment = Current.getNextNonComment();
1467     bool EndsInComma = Current.MatchingParen &&
1468                        Current.MatchingParen->Previous &&
1469                        Current.MatchingParen->Previous->is(tok::comma);
1470     AvoidBinPacking = EndsInComma || Current.is(TT_DictLiteral) ||
1471                       Style.Language == FormatStyle::LK_Proto ||
1472                       Style.Language == FormatStyle::LK_TextProto ||
1473                       !Style.BinPackArguments ||
1474                       (NextNoComment &&
1475                        NextNoComment->isOneOf(TT_DesignatedInitializerPeriod,
1476                                               TT_DesignatedInitializerLSquare));
1477     BreakBeforeParameter = EndsInComma;
1478     if (Current.ParameterCount > 1)
1479       NestedBlockIndent = std::max(NestedBlockIndent, State.Column + 1);
1480   } else {
1481     NewIndent = Style.ContinuationIndentWidth +
1482                 std::max(State.Stack.back().LastSpace,
1483                          State.Stack.back().StartOfFunctionCall);
1484 
1485     // Ensure that different different brackets force relative alignment, e.g.:
1486     // void SomeFunction(vector<  // break
1487     //                       int> v);
1488     // FIXME: We likely want to do this for more combinations of brackets.
1489     if (Current.is(tok::less) && Current.ParentBracket == tok::l_paren) {
1490       NewIndent = std::max(NewIndent, State.Stack.back().Indent);
1491       LastSpace = std::max(LastSpace, State.Stack.back().Indent);
1492     }
1493 
1494     bool EndsInComma =
1495         Current.MatchingParen &&
1496         Current.MatchingParen->getPreviousNonComment() &&
1497         Current.MatchingParen->getPreviousNonComment()->is(tok::comma);
1498 
1499     // If ObjCBinPackProtocolList is unspecified, fall back to BinPackParameters
1500     // for backwards compatibility.
1501     bool ObjCBinPackProtocolList =
1502         (Style.ObjCBinPackProtocolList == FormatStyle::BPS_Auto &&
1503          Style.BinPackParameters) ||
1504         Style.ObjCBinPackProtocolList == FormatStyle::BPS_Always;
1505 
1506     bool BinPackDeclaration =
1507         (State.Line->Type != LT_ObjCDecl && Style.BinPackParameters) ||
1508         (State.Line->Type == LT_ObjCDecl && ObjCBinPackProtocolList);
1509 
1510     AvoidBinPacking =
1511         (State.Stack.back().IsCSharpGenericTypeConstraint) ||
1512         (Style.Language == FormatStyle::LK_JavaScript && EndsInComma) ||
1513         (State.Line->MustBeDeclaration && !BinPackDeclaration) ||
1514         (!State.Line->MustBeDeclaration && !Style.BinPackArguments) ||
1515         (Style.ExperimentalAutoDetectBinPacking &&
1516          (Current.is(PPK_OnePerLine) ||
1517           (!BinPackInconclusiveFunctions && Current.is(PPK_Inconclusive))));
1518 
1519     if (Current.is(TT_ObjCMethodExpr) && Current.MatchingParen &&
1520         Style.ObjCBreakBeforeNestedBlockParam) {
1521       if (Style.ColumnLimit) {
1522         // If this '[' opens an ObjC call, determine whether all parameters fit
1523         // into one line and put one per line if they don't.
1524         if (getLengthToMatchingParen(Current, State.Stack) + State.Column >
1525             getColumnLimit(State))
1526           BreakBeforeParameter = true;
1527       } else {
1528         // For ColumnLimit = 0, we have to figure out whether there is or has to
1529         // be a line break within this call.
1530         for (const FormatToken *Tok = &Current;
1531              Tok && Tok != Current.MatchingParen; Tok = Tok->Next) {
1532           if (Tok->MustBreakBefore ||
1533               (Tok->CanBreakBefore && Tok->NewlinesBefore > 0)) {
1534             BreakBeforeParameter = true;
1535             break;
1536           }
1537         }
1538       }
1539     }
1540 
1541     if (Style.Language == FormatStyle::LK_JavaScript && EndsInComma)
1542       BreakBeforeParameter = true;
1543   }
1544   // Generally inherit NoLineBreak from the current scope to nested scope.
1545   // However, don't do this for non-empty nested blocks, dict literals and
1546   // array literals as these follow different indentation rules.
1547   bool NoLineBreak =
1548       Current.Children.empty() &&
1549       !Current.isOneOf(TT_DictLiteral, TT_ArrayInitializerLSquare) &&
1550       (State.Stack.back().NoLineBreak ||
1551        State.Stack.back().NoLineBreakInOperand ||
1552        (Current.is(TT_TemplateOpener) &&
1553         State.Stack.back().ContainsUnwrappedBuilder));
1554   State.Stack.push_back(
1555       ParenState(&Current, NewIndent, LastSpace, AvoidBinPacking, NoLineBreak));
1556   State.Stack.back().NestedBlockIndent = NestedBlockIndent;
1557   State.Stack.back().BreakBeforeParameter = BreakBeforeParameter;
1558   State.Stack.back().HasMultipleNestedBlocks =
1559       (Current.BlockParameterCount > 1);
1560 
1561   if (Style.BraceWrapping.BeforeLambdaBody && Current.Next != nullptr &&
1562       Current.Tok.is(tok::l_paren)) {
1563     // Search for any parameter that is a lambda
1564     FormatToken const *next = Current.Next;
1565     while (next != nullptr) {
1566       if (next->is(TT_LambdaLSquare)) {
1567         State.Stack.back().HasMultipleNestedBlocks = true;
1568         break;
1569       }
1570       next = next->Next;
1571     }
1572   }
1573 
1574   State.Stack.back().IsInsideObjCArrayLiteral =
1575       Current.is(TT_ArrayInitializerLSquare) && Current.Previous &&
1576       Current.Previous->is(tok::at);
1577 }
1578 
1579 void ContinuationIndenter::moveStatePastScopeCloser(LineState &State) {
1580   const FormatToken &Current = *State.NextToken;
1581   if (!Current.closesScope())
1582     return;
1583 
1584   // If we encounter a closing ), ], } or >, we can remove a level from our
1585   // stacks.
1586   if (State.Stack.size() > 1 &&
1587       (Current.isOneOf(tok::r_paren, tok::r_square, TT_TemplateString) ||
1588        (Current.is(tok::r_brace) && State.NextToken != State.Line->First) ||
1589        State.NextToken->is(TT_TemplateCloser) ||
1590        (Current.is(tok::greater) && Current.is(TT_DictLiteral))))
1591     State.Stack.pop_back();
1592 
1593   // Reevaluate whether ObjC message arguments fit into one line.
1594   // If a receiver spans multiple lines, e.g.:
1595   //   [[object block:^{
1596   //     return 42;
1597   //   }] a:42 b:42];
1598   // BreakBeforeParameter is calculated based on an incorrect assumption
1599   // (it is checked whether the whole expression fits into one line without
1600   // considering a line break inside a message receiver).
1601   // We check whether arguements fit after receiver scope closer (into the same
1602   // line).
1603   if (State.Stack.back().BreakBeforeParameter && Current.MatchingParen &&
1604       Current.MatchingParen->Previous) {
1605     const FormatToken &CurrentScopeOpener = *Current.MatchingParen->Previous;
1606     if (CurrentScopeOpener.is(TT_ObjCMethodExpr) &&
1607         CurrentScopeOpener.MatchingParen) {
1608       int NecessarySpaceInLine =
1609           getLengthToMatchingParen(CurrentScopeOpener, State.Stack) +
1610           CurrentScopeOpener.TotalLength - Current.TotalLength - 1;
1611       if (State.Column + Current.ColumnWidth + NecessarySpaceInLine <=
1612           Style.ColumnLimit)
1613         State.Stack.back().BreakBeforeParameter = false;
1614     }
1615   }
1616 
1617   if (Current.is(tok::r_square)) {
1618     // If this ends the array subscript expr, reset the corresponding value.
1619     const FormatToken *NextNonComment = Current.getNextNonComment();
1620     if (NextNonComment && NextNonComment->isNot(tok::l_square))
1621       State.Stack.back().StartOfArraySubscripts = 0;
1622   }
1623 }
1624 
1625 void ContinuationIndenter::moveStateToNewBlock(LineState &State) {
1626   unsigned NestedBlockIndent = State.Stack.back().NestedBlockIndent;
1627   // ObjC block sometimes follow special indentation rules.
1628   unsigned NewIndent =
1629       NestedBlockIndent + (State.NextToken->is(TT_ObjCBlockLBrace)
1630                                ? Style.ObjCBlockIndentWidth
1631                                : Style.IndentWidth);
1632   State.Stack.push_back(ParenState(State.NextToken, NewIndent,
1633                                    State.Stack.back().LastSpace,
1634                                    /*AvoidBinPacking=*/true,
1635                                    /*NoLineBreak=*/false));
1636   State.Stack.back().NestedBlockIndent = NestedBlockIndent;
1637   State.Stack.back().BreakBeforeParameter = true;
1638 }
1639 
1640 static unsigned getLastLineEndColumn(StringRef Text, unsigned StartColumn,
1641                                      unsigned TabWidth,
1642                                      encoding::Encoding Encoding) {
1643   size_t LastNewlinePos = Text.find_last_of("\n");
1644   if (LastNewlinePos == StringRef::npos) {
1645     return StartColumn +
1646            encoding::columnWidthWithTabs(Text, StartColumn, TabWidth, Encoding);
1647   } else {
1648     return encoding::columnWidthWithTabs(Text.substr(LastNewlinePos),
1649                                          /*StartColumn=*/0, TabWidth, Encoding);
1650   }
1651 }
1652 
1653 unsigned ContinuationIndenter::reformatRawStringLiteral(
1654     const FormatToken &Current, LineState &State,
1655     const FormatStyle &RawStringStyle, bool DryRun, bool Newline) {
1656   unsigned StartColumn = State.Column - Current.ColumnWidth;
1657   StringRef OldDelimiter = *getRawStringDelimiter(Current.TokenText);
1658   StringRef NewDelimiter =
1659       getCanonicalRawStringDelimiter(Style, RawStringStyle.Language);
1660   if (NewDelimiter.empty() || OldDelimiter.empty())
1661     NewDelimiter = OldDelimiter;
1662   // The text of a raw string is between the leading 'R"delimiter(' and the
1663   // trailing 'delimiter)"'.
1664   unsigned OldPrefixSize = 3 + OldDelimiter.size();
1665   unsigned OldSuffixSize = 2 + OldDelimiter.size();
1666   // We create a virtual text environment which expects a null-terminated
1667   // string, so we cannot use StringRef.
1668   std::string RawText = std::string(
1669       Current.TokenText.substr(OldPrefixSize).drop_back(OldSuffixSize));
1670   if (NewDelimiter != OldDelimiter) {
1671     // Don't update to the canonical delimiter 'deli' if ')deli"' occurs in the
1672     // raw string.
1673     std::string CanonicalDelimiterSuffix = (")" + NewDelimiter + "\"").str();
1674     if (StringRef(RawText).contains(CanonicalDelimiterSuffix))
1675       NewDelimiter = OldDelimiter;
1676   }
1677 
1678   unsigned NewPrefixSize = 3 + NewDelimiter.size();
1679   unsigned NewSuffixSize = 2 + NewDelimiter.size();
1680 
1681   // The first start column is the column the raw text starts after formatting.
1682   unsigned FirstStartColumn = StartColumn + NewPrefixSize;
1683 
1684   // The next start column is the intended indentation a line break inside
1685   // the raw string at level 0. It is determined by the following rules:
1686   //   - if the content starts on newline, it is one level more than the current
1687   //     indent, and
1688   //   - if the content does not start on a newline, it is the first start
1689   //     column.
1690   // These rules have the advantage that the formatted content both does not
1691   // violate the rectangle rule and visually flows within the surrounding
1692   // source.
1693   bool ContentStartsOnNewline = Current.TokenText[OldPrefixSize] == '\n';
1694   // If this token is the last parameter (checked by looking if it's followed by
1695   // `)` and is not on a newline, the base the indent off the line's nested
1696   // block indent. Otherwise, base the indent off the arguments indent, so we
1697   // can achieve:
1698   //
1699   // fffffffffff(1, 2, 3, R"pb(
1700   //     key1: 1  #
1701   //     key2: 2)pb");
1702   //
1703   // fffffffffff(1, 2, 3,
1704   //             R"pb(
1705   //               key1: 1  #
1706   //               key2: 2
1707   //             )pb");
1708   //
1709   // fffffffffff(1, 2, 3,
1710   //             R"pb(
1711   //               key1: 1  #
1712   //               key2: 2
1713   //             )pb",
1714   //             5);
1715   unsigned CurrentIndent =
1716       (!Newline && Current.Next && Current.Next->is(tok::r_paren))
1717           ? State.Stack.back().NestedBlockIndent
1718           : State.Stack.back().Indent;
1719   unsigned NextStartColumn = ContentStartsOnNewline
1720                                  ? CurrentIndent + Style.IndentWidth
1721                                  : FirstStartColumn;
1722 
1723   // The last start column is the column the raw string suffix starts if it is
1724   // put on a newline.
1725   // The last start column is the intended indentation of the raw string postfix
1726   // if it is put on a newline. It is determined by the following rules:
1727   //   - if the raw string prefix starts on a newline, it is the column where
1728   //     that raw string prefix starts, and
1729   //   - if the raw string prefix does not start on a newline, it is the current
1730   //     indent.
1731   unsigned LastStartColumn =
1732       Current.NewlinesBefore ? FirstStartColumn - NewPrefixSize : CurrentIndent;
1733 
1734   std::pair<tooling::Replacements, unsigned> Fixes = internal::reformat(
1735       RawStringStyle, RawText, {tooling::Range(0, RawText.size())},
1736       FirstStartColumn, NextStartColumn, LastStartColumn, "<stdin>",
1737       /*Status=*/nullptr);
1738 
1739   auto NewCode = applyAllReplacements(RawText, Fixes.first);
1740   tooling::Replacements NoFixes;
1741   if (!NewCode) {
1742     return addMultilineToken(Current, State);
1743   }
1744   if (!DryRun) {
1745     if (NewDelimiter != OldDelimiter) {
1746       // In 'R"delimiter(...', the delimiter starts 2 characters after the start
1747       // of the token.
1748       SourceLocation PrefixDelimiterStart =
1749           Current.Tok.getLocation().getLocWithOffset(2);
1750       auto PrefixErr = Whitespaces.addReplacement(tooling::Replacement(
1751           SourceMgr, PrefixDelimiterStart, OldDelimiter.size(), NewDelimiter));
1752       if (PrefixErr) {
1753         llvm::errs()
1754             << "Failed to update the prefix delimiter of a raw string: "
1755             << llvm::toString(std::move(PrefixErr)) << "\n";
1756       }
1757       // In 'R"delimiter(...)delimiter"', the suffix delimiter starts at
1758       // position length - 1 - |delimiter|.
1759       SourceLocation SuffixDelimiterStart =
1760           Current.Tok.getLocation().getLocWithOffset(Current.TokenText.size() -
1761                                                      1 - OldDelimiter.size());
1762       auto SuffixErr = Whitespaces.addReplacement(tooling::Replacement(
1763           SourceMgr, SuffixDelimiterStart, OldDelimiter.size(), NewDelimiter));
1764       if (SuffixErr) {
1765         llvm::errs()
1766             << "Failed to update the suffix delimiter of a raw string: "
1767             << llvm::toString(std::move(SuffixErr)) << "\n";
1768       }
1769     }
1770     SourceLocation OriginLoc =
1771         Current.Tok.getLocation().getLocWithOffset(OldPrefixSize);
1772     for (const tooling::Replacement &Fix : Fixes.first) {
1773       auto Err = Whitespaces.addReplacement(tooling::Replacement(
1774           SourceMgr, OriginLoc.getLocWithOffset(Fix.getOffset()),
1775           Fix.getLength(), Fix.getReplacementText()));
1776       if (Err) {
1777         llvm::errs() << "Failed to reformat raw string: "
1778                      << llvm::toString(std::move(Err)) << "\n";
1779       }
1780     }
1781   }
1782   unsigned RawLastLineEndColumn = getLastLineEndColumn(
1783       *NewCode, FirstStartColumn, Style.TabWidth, Encoding);
1784   State.Column = RawLastLineEndColumn + NewSuffixSize;
1785   // Since we're updating the column to after the raw string literal here, we
1786   // have to manually add the penalty for the prefix R"delim( over the column
1787   // limit.
1788   unsigned PrefixExcessCharacters =
1789       StartColumn + NewPrefixSize > Style.ColumnLimit
1790           ? StartColumn + NewPrefixSize - Style.ColumnLimit
1791           : 0;
1792   bool IsMultiline =
1793       ContentStartsOnNewline || (NewCode->find('\n') != std::string::npos);
1794   if (IsMultiline) {
1795     // Break before further function parameters on all levels.
1796     for (unsigned i = 0, e = State.Stack.size(); i != e; ++i)
1797       State.Stack[i].BreakBeforeParameter = true;
1798   }
1799   return Fixes.second + PrefixExcessCharacters * Style.PenaltyExcessCharacter;
1800 }
1801 
1802 unsigned ContinuationIndenter::addMultilineToken(const FormatToken &Current,
1803                                                  LineState &State) {
1804   // Break before further function parameters on all levels.
1805   for (unsigned i = 0, e = State.Stack.size(); i != e; ++i)
1806     State.Stack[i].BreakBeforeParameter = true;
1807 
1808   unsigned ColumnsUsed = State.Column;
1809   // We can only affect layout of the first and the last line, so the penalty
1810   // for all other lines is constant, and we ignore it.
1811   State.Column = Current.LastLineColumnWidth;
1812 
1813   if (ColumnsUsed > getColumnLimit(State))
1814     return Style.PenaltyExcessCharacter * (ColumnsUsed - getColumnLimit(State));
1815   return 0;
1816 }
1817 
1818 unsigned ContinuationIndenter::handleEndOfLine(const FormatToken &Current,
1819                                                LineState &State, bool DryRun,
1820                                                bool AllowBreak, bool Newline) {
1821   unsigned Penalty = 0;
1822   // Compute the raw string style to use in case this is a raw string literal
1823   // that can be reformatted.
1824   auto RawStringStyle = getRawStringStyle(Current, State);
1825   if (RawStringStyle && !Current.Finalized) {
1826     Penalty = reformatRawStringLiteral(Current, State, *RawStringStyle, DryRun,
1827                                        Newline);
1828   } else if (Current.IsMultiline && Current.isNot(TT_BlockComment)) {
1829     // Don't break multi-line tokens other than block comments and raw string
1830     // literals. Instead, just update the state.
1831     Penalty = addMultilineToken(Current, State);
1832   } else if (State.Line->Type != LT_ImportStatement) {
1833     // We generally don't break import statements.
1834     LineState OriginalState = State;
1835 
1836     // Whether we force the reflowing algorithm to stay strictly within the
1837     // column limit.
1838     bool Strict = false;
1839     // Whether the first non-strict attempt at reflowing did intentionally
1840     // exceed the column limit.
1841     bool Exceeded = false;
1842     std::tie(Penalty, Exceeded) = breakProtrudingToken(
1843         Current, State, AllowBreak, /*DryRun=*/true, Strict);
1844     if (Exceeded) {
1845       // If non-strict reflowing exceeds the column limit, try whether strict
1846       // reflowing leads to an overall lower penalty.
1847       LineState StrictState = OriginalState;
1848       unsigned StrictPenalty =
1849           breakProtrudingToken(Current, StrictState, AllowBreak,
1850                                /*DryRun=*/true, /*Strict=*/true)
1851               .first;
1852       Strict = StrictPenalty <= Penalty;
1853       if (Strict) {
1854         Penalty = StrictPenalty;
1855         State = StrictState;
1856       }
1857     }
1858     if (!DryRun) {
1859       // If we're not in dry-run mode, apply the changes with the decision on
1860       // strictness made above.
1861       breakProtrudingToken(Current, OriginalState, AllowBreak, /*DryRun=*/false,
1862                            Strict);
1863     }
1864   }
1865   if (State.Column > getColumnLimit(State)) {
1866     unsigned ExcessCharacters = State.Column - getColumnLimit(State);
1867     Penalty += Style.PenaltyExcessCharacter * ExcessCharacters;
1868   }
1869   return Penalty;
1870 }
1871 
1872 // Returns the enclosing function name of a token, or the empty string if not
1873 // found.
1874 static StringRef getEnclosingFunctionName(const FormatToken &Current) {
1875   // Look for: 'function(' or 'function<templates>(' before Current.
1876   auto Tok = Current.getPreviousNonComment();
1877   if (!Tok || !Tok->is(tok::l_paren))
1878     return "";
1879   Tok = Tok->getPreviousNonComment();
1880   if (!Tok)
1881     return "";
1882   if (Tok->is(TT_TemplateCloser)) {
1883     Tok = Tok->MatchingParen;
1884     if (Tok)
1885       Tok = Tok->getPreviousNonComment();
1886   }
1887   if (!Tok || !Tok->is(tok::identifier))
1888     return "";
1889   return Tok->TokenText;
1890 }
1891 
1892 llvm::Optional<FormatStyle>
1893 ContinuationIndenter::getRawStringStyle(const FormatToken &Current,
1894                                         const LineState &State) {
1895   if (!Current.isStringLiteral())
1896     return None;
1897   auto Delimiter = getRawStringDelimiter(Current.TokenText);
1898   if (!Delimiter)
1899     return None;
1900   auto RawStringStyle = RawStringFormats.getDelimiterStyle(*Delimiter);
1901   if (!RawStringStyle && Delimiter->empty())
1902     RawStringStyle = RawStringFormats.getEnclosingFunctionStyle(
1903         getEnclosingFunctionName(Current));
1904   if (!RawStringStyle)
1905     return None;
1906   RawStringStyle->ColumnLimit = getColumnLimit(State);
1907   return RawStringStyle;
1908 }
1909 
1910 std::unique_ptr<BreakableToken>
1911 ContinuationIndenter::createBreakableToken(const FormatToken &Current,
1912                                            LineState &State, bool AllowBreak) {
1913   unsigned StartColumn = State.Column - Current.ColumnWidth;
1914   if (Current.isStringLiteral()) {
1915     // FIXME: String literal breaking is currently disabled for C#, Java and
1916     // JavaScript, as it requires strings to be merged using "+" which we
1917     // don't support.
1918     if (Style.Language == FormatStyle::LK_Java ||
1919         Style.Language == FormatStyle::LK_JavaScript || Style.isCSharp() ||
1920         !Style.BreakStringLiterals || !AllowBreak)
1921       return nullptr;
1922 
1923     // Don't break string literals inside preprocessor directives (except for
1924     // #define directives, as their contents are stored in separate lines and
1925     // are not affected by this check).
1926     // This way we avoid breaking code with line directives and unknown
1927     // preprocessor directives that contain long string literals.
1928     if (State.Line->Type == LT_PreprocessorDirective)
1929       return nullptr;
1930     // Exempts unterminated string literals from line breaking. The user will
1931     // likely want to terminate the string before any line breaking is done.
1932     if (Current.IsUnterminatedLiteral)
1933       return nullptr;
1934     // Don't break string literals inside Objective-C array literals (doing so
1935     // raises the warning -Wobjc-string-concatenation).
1936     if (State.Stack.back().IsInsideObjCArrayLiteral) {
1937       return nullptr;
1938     }
1939 
1940     StringRef Text = Current.TokenText;
1941     StringRef Prefix;
1942     StringRef Postfix;
1943     // FIXME: Handle whitespace between '_T', '(', '"..."', and ')'.
1944     // FIXME: Store Prefix and Suffix (or PrefixLength and SuffixLength to
1945     // reduce the overhead) for each FormatToken, which is a string, so that we
1946     // don't run multiple checks here on the hot path.
1947     if ((Text.endswith(Postfix = "\"") &&
1948          (Text.startswith(Prefix = "@\"") || Text.startswith(Prefix = "\"") ||
1949           Text.startswith(Prefix = "u\"") || Text.startswith(Prefix = "U\"") ||
1950           Text.startswith(Prefix = "u8\"") ||
1951           Text.startswith(Prefix = "L\""))) ||
1952         (Text.startswith(Prefix = "_T(\"") && Text.endswith(Postfix = "\")"))) {
1953       // We need this to address the case where there is an unbreakable tail
1954       // only if certain other formatting decisions have been taken. The
1955       // UnbreakableTailLength of Current is an overapproximation is that case
1956       // and we need to be correct here.
1957       unsigned UnbreakableTailLength = (State.NextToken && canBreak(State))
1958                                            ? 0
1959                                            : Current.UnbreakableTailLength;
1960       return std::make_unique<BreakableStringLiteral>(
1961           Current, StartColumn, Prefix, Postfix, UnbreakableTailLength,
1962           State.Line->InPPDirective, Encoding, Style);
1963     }
1964   } else if (Current.is(TT_BlockComment)) {
1965     if (!Style.ReflowComments ||
1966         // If a comment token switches formatting, like
1967         // /* clang-format on */, we don't want to break it further,
1968         // but we may still want to adjust its indentation.
1969         switchesFormatting(Current)) {
1970       return nullptr;
1971     }
1972     return std::make_unique<BreakableBlockComment>(
1973         Current, StartColumn, Current.OriginalColumn, !Current.Previous,
1974         State.Line->InPPDirective, Encoding, Style, Whitespaces.useCRLF());
1975   } else if (Current.is(TT_LineComment) &&
1976              (Current.Previous == nullptr ||
1977               Current.Previous->isNot(TT_ImplicitStringLiteral))) {
1978     if (!Style.ReflowComments ||
1979         CommentPragmasRegex.match(Current.TokenText.substr(2)) ||
1980         switchesFormatting(Current))
1981       return nullptr;
1982     return std::make_unique<BreakableLineCommentSection>(
1983         Current, StartColumn, Current.OriginalColumn, !Current.Previous,
1984         /*InPPDirective=*/false, Encoding, Style);
1985   }
1986   return nullptr;
1987 }
1988 
1989 std::pair<unsigned, bool>
1990 ContinuationIndenter::breakProtrudingToken(const FormatToken &Current,
1991                                            LineState &State, bool AllowBreak,
1992                                            bool DryRun, bool Strict) {
1993   std::unique_ptr<const BreakableToken> Token =
1994       createBreakableToken(Current, State, AllowBreak);
1995   if (!Token)
1996     return {0, false};
1997   assert(Token->getLineCount() > 0);
1998   unsigned ColumnLimit = getColumnLimit(State);
1999   if (Current.is(TT_LineComment)) {
2000     // We don't insert backslashes when breaking line comments.
2001     ColumnLimit = Style.ColumnLimit;
2002   }
2003   if (Current.UnbreakableTailLength >= ColumnLimit)
2004     return {0, false};
2005   // ColumnWidth was already accounted into State.Column before calling
2006   // breakProtrudingToken.
2007   unsigned StartColumn = State.Column - Current.ColumnWidth;
2008   unsigned NewBreakPenalty = Current.isStringLiteral()
2009                                  ? Style.PenaltyBreakString
2010                                  : Style.PenaltyBreakComment;
2011   // Stores whether we intentionally decide to let a line exceed the column
2012   // limit.
2013   bool Exceeded = false;
2014   // Stores whether we introduce a break anywhere in the token.
2015   bool BreakInserted = Token->introducesBreakBeforeToken();
2016   // Store whether we inserted a new line break at the end of the previous
2017   // logical line.
2018   bool NewBreakBefore = false;
2019   // We use a conservative reflowing strategy. Reflow starts after a line is
2020   // broken or the corresponding whitespace compressed. Reflow ends as soon as a
2021   // line that doesn't get reflown with the previous line is reached.
2022   bool Reflow = false;
2023   // Keep track of where we are in the token:
2024   // Where we are in the content of the current logical line.
2025   unsigned TailOffset = 0;
2026   // The column number we're currently at.
2027   unsigned ContentStartColumn =
2028       Token->getContentStartColumn(0, /*Break=*/false);
2029   // The number of columns left in the current logical line after TailOffset.
2030   unsigned RemainingTokenColumns =
2031       Token->getRemainingLength(0, TailOffset, ContentStartColumn);
2032   // Adapt the start of the token, for example indent.
2033   if (!DryRun)
2034     Token->adaptStartOfLine(0, Whitespaces);
2035 
2036   unsigned ContentIndent = 0;
2037   unsigned Penalty = 0;
2038   LLVM_DEBUG(llvm::dbgs() << "Breaking protruding token at column "
2039                           << StartColumn << ".\n");
2040   for (unsigned LineIndex = 0, EndIndex = Token->getLineCount();
2041        LineIndex != EndIndex; ++LineIndex) {
2042     LLVM_DEBUG(llvm::dbgs()
2043                << "  Line: " << LineIndex << " (Reflow: " << Reflow << ")\n");
2044     NewBreakBefore = false;
2045     // If we did reflow the previous line, we'll try reflowing again. Otherwise
2046     // we'll start reflowing if the current line is broken or whitespace is
2047     // compressed.
2048     bool TryReflow = Reflow;
2049     // Break the current token until we can fit the rest of the line.
2050     while (ContentStartColumn + RemainingTokenColumns > ColumnLimit) {
2051       LLVM_DEBUG(llvm::dbgs() << "    Over limit, need: "
2052                               << (ContentStartColumn + RemainingTokenColumns)
2053                               << ", space: " << ColumnLimit
2054                               << ", reflown prefix: " << ContentStartColumn
2055                               << ", offset in line: " << TailOffset << "\n");
2056       // If the current token doesn't fit, find the latest possible split in the
2057       // current line so that breaking at it will be under the column limit.
2058       // FIXME: Use the earliest possible split while reflowing to correctly
2059       // compress whitespace within a line.
2060       BreakableToken::Split Split =
2061           Token->getSplit(LineIndex, TailOffset, ColumnLimit,
2062                           ContentStartColumn, CommentPragmasRegex);
2063       if (Split.first == StringRef::npos) {
2064         // No break opportunity - update the penalty and continue with the next
2065         // logical line.
2066         if (LineIndex < EndIndex - 1)
2067           // The last line's penalty is handled in addNextStateToQueue() or when
2068           // calling replaceWhitespaceAfterLastLine below.
2069           Penalty += Style.PenaltyExcessCharacter *
2070                      (ContentStartColumn + RemainingTokenColumns - ColumnLimit);
2071         LLVM_DEBUG(llvm::dbgs() << "    No break opportunity.\n");
2072         break;
2073       }
2074       assert(Split.first != 0);
2075 
2076       if (Token->supportsReflow()) {
2077         // Check whether the next natural split point after the current one can
2078         // still fit the line, either because we can compress away whitespace,
2079         // or because the penalty the excess characters introduce is lower than
2080         // the break penalty.
2081         // We only do this for tokens that support reflowing, and thus allow us
2082         // to change the whitespace arbitrarily (e.g. comments).
2083         // Other tokens, like string literals, can be broken on arbitrary
2084         // positions.
2085 
2086         // First, compute the columns from TailOffset to the next possible split
2087         // position.
2088         // For example:
2089         // ColumnLimit:     |
2090         // // Some text   that    breaks
2091         //    ^ tail offset
2092         //             ^-- split
2093         //    ^-------- to split columns
2094         //                    ^--- next split
2095         //    ^--------------- to next split columns
2096         unsigned ToSplitColumns = Token->getRangeLength(
2097             LineIndex, TailOffset, Split.first, ContentStartColumn);
2098         LLVM_DEBUG(llvm::dbgs() << "    ToSplit: " << ToSplitColumns << "\n");
2099 
2100         BreakableToken::Split NextSplit = Token->getSplit(
2101             LineIndex, TailOffset + Split.first + Split.second, ColumnLimit,
2102             ContentStartColumn + ToSplitColumns + 1, CommentPragmasRegex);
2103         // Compute the columns necessary to fit the next non-breakable sequence
2104         // into the current line.
2105         unsigned ToNextSplitColumns = 0;
2106         if (NextSplit.first == StringRef::npos) {
2107           ToNextSplitColumns = Token->getRemainingLength(LineIndex, TailOffset,
2108                                                          ContentStartColumn);
2109         } else {
2110           ToNextSplitColumns = Token->getRangeLength(
2111               LineIndex, TailOffset,
2112               Split.first + Split.second + NextSplit.first, ContentStartColumn);
2113         }
2114         // Compress the whitespace between the break and the start of the next
2115         // unbreakable sequence.
2116         ToNextSplitColumns =
2117             Token->getLengthAfterCompression(ToNextSplitColumns, Split);
2118         LLVM_DEBUG(llvm::dbgs()
2119                    << "    ContentStartColumn: " << ContentStartColumn << "\n");
2120         LLVM_DEBUG(llvm::dbgs()
2121                    << "    ToNextSplit: " << ToNextSplitColumns << "\n");
2122         // If the whitespace compression makes us fit, continue on the current
2123         // line.
2124         bool ContinueOnLine =
2125             ContentStartColumn + ToNextSplitColumns <= ColumnLimit;
2126         unsigned ExcessCharactersPenalty = 0;
2127         if (!ContinueOnLine && !Strict) {
2128           // Similarly, if the excess characters' penalty is lower than the
2129           // penalty of introducing a new break, continue on the current line.
2130           ExcessCharactersPenalty =
2131               (ContentStartColumn + ToNextSplitColumns - ColumnLimit) *
2132               Style.PenaltyExcessCharacter;
2133           LLVM_DEBUG(llvm::dbgs()
2134                      << "    Penalty excess: " << ExcessCharactersPenalty
2135                      << "\n            break : " << NewBreakPenalty << "\n");
2136           if (ExcessCharactersPenalty < NewBreakPenalty) {
2137             Exceeded = true;
2138             ContinueOnLine = true;
2139           }
2140         }
2141         if (ContinueOnLine) {
2142           LLVM_DEBUG(llvm::dbgs() << "    Continuing on line...\n");
2143           // The current line fits after compressing the whitespace - reflow
2144           // the next line into it if possible.
2145           TryReflow = true;
2146           if (!DryRun)
2147             Token->compressWhitespace(LineIndex, TailOffset, Split,
2148                                       Whitespaces);
2149           // When we continue on the same line, leave one space between content.
2150           ContentStartColumn += ToSplitColumns + 1;
2151           Penalty += ExcessCharactersPenalty;
2152           TailOffset += Split.first + Split.second;
2153           RemainingTokenColumns = Token->getRemainingLength(
2154               LineIndex, TailOffset, ContentStartColumn);
2155           continue;
2156         }
2157       }
2158       LLVM_DEBUG(llvm::dbgs() << "    Breaking...\n");
2159       // Update the ContentIndent only if the current line was not reflown with
2160       // the previous line, since in that case the previous line should still
2161       // determine the ContentIndent. Also never intent the last line.
2162       if (!Reflow)
2163         ContentIndent = Token->getContentIndent(LineIndex);
2164       LLVM_DEBUG(llvm::dbgs()
2165                  << "    ContentIndent: " << ContentIndent << "\n");
2166       ContentStartColumn = ContentIndent + Token->getContentStartColumn(
2167                                                LineIndex, /*Break=*/true);
2168 
2169       unsigned NewRemainingTokenColumns = Token->getRemainingLength(
2170           LineIndex, TailOffset + Split.first + Split.second,
2171           ContentStartColumn);
2172       if (NewRemainingTokenColumns == 0) {
2173         // No content to indent.
2174         ContentIndent = 0;
2175         ContentStartColumn =
2176             Token->getContentStartColumn(LineIndex, /*Break=*/true);
2177         NewRemainingTokenColumns = Token->getRemainingLength(
2178             LineIndex, TailOffset + Split.first + Split.second,
2179             ContentStartColumn);
2180       }
2181 
2182       // When breaking before a tab character, it may be moved by a few columns,
2183       // but will still be expanded to the next tab stop, so we don't save any
2184       // columns.
2185       if (NewRemainingTokenColumns == RemainingTokenColumns) {
2186         // FIXME: Do we need to adjust the penalty?
2187         break;
2188       }
2189       assert(NewRemainingTokenColumns < RemainingTokenColumns);
2190 
2191       LLVM_DEBUG(llvm::dbgs() << "    Breaking at: " << TailOffset + Split.first
2192                               << ", " << Split.second << "\n");
2193       if (!DryRun)
2194         Token->insertBreak(LineIndex, TailOffset, Split, ContentIndent,
2195                            Whitespaces);
2196 
2197       Penalty += NewBreakPenalty;
2198       TailOffset += Split.first + Split.second;
2199       RemainingTokenColumns = NewRemainingTokenColumns;
2200       BreakInserted = true;
2201       NewBreakBefore = true;
2202     }
2203     // In case there's another line, prepare the state for the start of the next
2204     // line.
2205     if (LineIndex + 1 != EndIndex) {
2206       unsigned NextLineIndex = LineIndex + 1;
2207       if (NewBreakBefore)
2208         // After breaking a line, try to reflow the next line into the current
2209         // one once RemainingTokenColumns fits.
2210         TryReflow = true;
2211       if (TryReflow) {
2212         // We decided that we want to try reflowing the next line into the
2213         // current one.
2214         // We will now adjust the state as if the reflow is successful (in
2215         // preparation for the next line), and see whether that works. If we
2216         // decide that we cannot reflow, we will later reset the state to the
2217         // start of the next line.
2218         Reflow = false;
2219         // As we did not continue breaking the line, RemainingTokenColumns is
2220         // known to fit after ContentStartColumn. Adapt ContentStartColumn to
2221         // the position at which we want to format the next line if we do
2222         // actually reflow.
2223         // When we reflow, we need to add a space between the end of the current
2224         // line and the next line's start column.
2225         ContentStartColumn += RemainingTokenColumns + 1;
2226         // Get the split that we need to reflow next logical line into the end
2227         // of the current one; the split will include any leading whitespace of
2228         // the next logical line.
2229         BreakableToken::Split SplitBeforeNext =
2230             Token->getReflowSplit(NextLineIndex, CommentPragmasRegex);
2231         LLVM_DEBUG(llvm::dbgs()
2232                    << "    Size of reflown text: " << ContentStartColumn
2233                    << "\n    Potential reflow split: ");
2234         if (SplitBeforeNext.first != StringRef::npos) {
2235           LLVM_DEBUG(llvm::dbgs() << SplitBeforeNext.first << ", "
2236                                   << SplitBeforeNext.second << "\n");
2237           TailOffset = SplitBeforeNext.first + SplitBeforeNext.second;
2238           // If the rest of the next line fits into the current line below the
2239           // column limit, we can safely reflow.
2240           RemainingTokenColumns = Token->getRemainingLength(
2241               NextLineIndex, TailOffset, ContentStartColumn);
2242           Reflow = true;
2243           if (ContentStartColumn + RemainingTokenColumns > ColumnLimit) {
2244             LLVM_DEBUG(llvm::dbgs()
2245                        << "    Over limit after reflow, need: "
2246                        << (ContentStartColumn + RemainingTokenColumns)
2247                        << ", space: " << ColumnLimit
2248                        << ", reflown prefix: " << ContentStartColumn
2249                        << ", offset in line: " << TailOffset << "\n");
2250             // If the whole next line does not fit, try to find a point in
2251             // the next line at which we can break so that attaching the part
2252             // of the next line to that break point onto the current line is
2253             // below the column limit.
2254             BreakableToken::Split Split =
2255                 Token->getSplit(NextLineIndex, TailOffset, ColumnLimit,
2256                                 ContentStartColumn, CommentPragmasRegex);
2257             if (Split.first == StringRef::npos) {
2258               LLVM_DEBUG(llvm::dbgs() << "    Did not find later break\n");
2259               Reflow = false;
2260             } else {
2261               // Check whether the first split point gets us below the column
2262               // limit. Note that we will execute this split below as part of
2263               // the normal token breaking and reflow logic within the line.
2264               unsigned ToSplitColumns = Token->getRangeLength(
2265                   NextLineIndex, TailOffset, Split.first, ContentStartColumn);
2266               if (ContentStartColumn + ToSplitColumns > ColumnLimit) {
2267                 LLVM_DEBUG(llvm::dbgs() << "    Next split protrudes, need: "
2268                                         << (ContentStartColumn + ToSplitColumns)
2269                                         << ", space: " << ColumnLimit);
2270                 unsigned ExcessCharactersPenalty =
2271                     (ContentStartColumn + ToSplitColumns - ColumnLimit) *
2272                     Style.PenaltyExcessCharacter;
2273                 if (NewBreakPenalty < ExcessCharactersPenalty) {
2274                   Reflow = false;
2275                 }
2276               }
2277             }
2278           }
2279         } else {
2280           LLVM_DEBUG(llvm::dbgs() << "not found.\n");
2281         }
2282       }
2283       if (!Reflow) {
2284         // If we didn't reflow into the next line, the only space to consider is
2285         // the next logical line. Reset our state to match the start of the next
2286         // line.
2287         TailOffset = 0;
2288         ContentStartColumn =
2289             Token->getContentStartColumn(NextLineIndex, /*Break=*/false);
2290         RemainingTokenColumns = Token->getRemainingLength(
2291             NextLineIndex, TailOffset, ContentStartColumn);
2292         // Adapt the start of the token, for example indent.
2293         if (!DryRun)
2294           Token->adaptStartOfLine(NextLineIndex, Whitespaces);
2295       } else {
2296         // If we found a reflow split and have added a new break before the next
2297         // line, we are going to remove the line break at the start of the next
2298         // logical line. For example, here we'll add a new line break after
2299         // 'text', and subsequently delete the line break between 'that' and
2300         // 'reflows'.
2301         //   // some text that
2302         //   // reflows
2303         // ->
2304         //   // some text
2305         //   // that reflows
2306         // When adding the line break, we also added the penalty for it, so we
2307         // need to subtract that penalty again when we remove the line break due
2308         // to reflowing.
2309         if (NewBreakBefore) {
2310           assert(Penalty >= NewBreakPenalty);
2311           Penalty -= NewBreakPenalty;
2312         }
2313         if (!DryRun)
2314           Token->reflow(NextLineIndex, Whitespaces);
2315       }
2316     }
2317   }
2318 
2319   BreakableToken::Split SplitAfterLastLine =
2320       Token->getSplitAfterLastLine(TailOffset);
2321   if (SplitAfterLastLine.first != StringRef::npos) {
2322     LLVM_DEBUG(llvm::dbgs() << "Replacing whitespace after last line.\n");
2323 
2324     // We add the last line's penalty here, since that line is going to be split
2325     // now.
2326     Penalty += Style.PenaltyExcessCharacter *
2327                (ContentStartColumn + RemainingTokenColumns - ColumnLimit);
2328 
2329     if (!DryRun)
2330       Token->replaceWhitespaceAfterLastLine(TailOffset, SplitAfterLastLine,
2331                                             Whitespaces);
2332     ContentStartColumn =
2333         Token->getContentStartColumn(Token->getLineCount() - 1, /*Break=*/true);
2334     RemainingTokenColumns = Token->getRemainingLength(
2335         Token->getLineCount() - 1,
2336         TailOffset + SplitAfterLastLine.first + SplitAfterLastLine.second,
2337         ContentStartColumn);
2338   }
2339 
2340   State.Column = ContentStartColumn + RemainingTokenColumns -
2341                  Current.UnbreakableTailLength;
2342 
2343   if (BreakInserted) {
2344     // If we break the token inside a parameter list, we need to break before
2345     // the next parameter on all levels, so that the next parameter is clearly
2346     // visible. Line comments already introduce a break.
2347     if (Current.isNot(TT_LineComment)) {
2348       for (unsigned i = 0, e = State.Stack.size(); i != e; ++i)
2349         State.Stack[i].BreakBeforeParameter = true;
2350     }
2351 
2352     if (Current.is(TT_BlockComment))
2353       State.NoContinuation = true;
2354 
2355     State.Stack.back().LastSpace = StartColumn;
2356   }
2357 
2358   Token->updateNextToken(State);
2359 
2360   return {Penalty, Exceeded};
2361 }
2362 
2363 unsigned ContinuationIndenter::getColumnLimit(const LineState &State) const {
2364   // In preprocessor directives reserve two chars for trailing " \"
2365   return Style.ColumnLimit - (State.Line->InPPDirective ? 2 : 0);
2366 }
2367 
2368 bool ContinuationIndenter::nextIsMultilineString(const LineState &State) {
2369   const FormatToken &Current = *State.NextToken;
2370   if (!Current.isStringLiteral() || Current.is(TT_ImplicitStringLiteral))
2371     return false;
2372   // We never consider raw string literals "multiline" for the purpose of
2373   // AlwaysBreakBeforeMultilineStrings implementation as they are special-cased
2374   // (see TokenAnnotator::mustBreakBefore().
2375   if (Current.TokenText.startswith("R\""))
2376     return false;
2377   if (Current.IsMultiline)
2378     return true;
2379   if (Current.getNextNonComment() &&
2380       Current.getNextNonComment()->isStringLiteral())
2381     return true; // Implicit concatenation.
2382   if (Style.ColumnLimit != 0 && Style.BreakStringLiterals &&
2383       State.Column + Current.ColumnWidth + Current.UnbreakableTailLength >
2384           Style.ColumnLimit)
2385     return true; // String will be split.
2386   return false;
2387 }
2388 
2389 } // namespace format
2390 } // namespace clang
2391