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 "FormatToken.h"
18 #include "WhitespaceManager.h"
19 #include "clang/Basic/OperatorPrecedence.h"
20 #include "clang/Basic/SourceManager.h"
21 #include "clang/Format/Format.h"
22 #include "llvm/ADT/StringSet.h"
23 #include "llvm/Support/Debug.h"
24 
25 #define DEBUG_TYPE "format-indenter"
26 
27 namespace clang {
28 namespace format {
29 
30 // Returns true if a TT_SelectorName should be indented when wrapped,
31 // false otherwise.
32 static bool shouldIndentWrappedSelectorName(const FormatStyle &Style,
33                                             LineType LineType) {
34   return Style.IndentWrappedFunctionNames || LineType == LT_ObjCMethodDecl;
35 }
36 
37 // Returns the length of everything up to the first possible line break after
38 // the ), ], } or > matching \c Tok.
39 static unsigned getLengthToMatchingParen(const FormatToken &Tok,
40                                          const std::vector<ParenState> &Stack) {
41   // Normally whether or not a break before T is possible is calculated and
42   // stored in T.CanBreakBefore. Braces, array initializers and text proto
43   // messages like `key: < ... >` are an exception: a break is possible
44   // before a closing brace R if a break was inserted after the corresponding
45   // opening brace. The information about whether or not a break is needed
46   // before a closing brace R is stored in the ParenState field
47   // S.BreakBeforeClosingBrace where S is the state that R closes.
48   //
49   // In order to decide whether there can be a break before encountered right
50   // braces, this implementation iterates over the sequence of tokens and over
51   // the paren stack in lockstep, keeping track of the stack level which visited
52   // right braces correspond to in MatchingStackIndex.
53   //
54   // For example, consider:
55   // L. <- line number
56   // 1. {
57   // 2. {1},
58   // 3. {2},
59   // 4. {{3}}}
60   //     ^ where we call this method with this token.
61   // The paren stack at this point contains 3 brace levels:
62   //  0. { at line 1, BreakBeforeClosingBrace: true
63   //  1. first { at line 4, BreakBeforeClosingBrace: false
64   //  2. second { at line 4, BreakBeforeClosingBrace: false,
65   //  where there might be fake parens levels in-between these levels.
66   // The algorithm will start at the first } on line 4, which is the matching
67   // brace of the initial left brace and at level 2 of the stack. Then,
68   // examining BreakBeforeClosingBrace: false at level 2, it will continue to
69   // the second } on line 4, and will traverse the stack downwards until it
70   // finds the matching { on level 1. Then, examining BreakBeforeClosingBrace:
71   // false at level 1, it will continue to the third } on line 4 and will
72   // traverse the stack downwards until it finds the matching { on level 0.
73   // Then, examining BreakBeforeClosingBrace: true at level 0, the algorithm
74   // will stop and will use the second } on line 4 to determine the length to
75   // return, as in this example the range will include the tokens: {3}}
76   //
77   // The algorithm will only traverse the stack if it encounters braces, array
78   // initializer squares or text proto angle brackets.
79   if (!Tok.MatchingParen)
80     return 0;
81   FormatToken *End = Tok.MatchingParen;
82   // Maintains a stack level corresponding to the current End token.
83   int MatchingStackIndex = Stack.size() - 1;
84   // Traverses the stack downwards, looking for the level to which LBrace
85   // corresponds. Returns either a pointer to the matching level or nullptr if
86   // LParen is not found in the initial portion of the stack up to
87   // MatchingStackIndex.
88   auto FindParenState = [&](const FormatToken *LBrace) -> const ParenState * {
89     while (MatchingStackIndex >= 0 && Stack[MatchingStackIndex].Tok != LBrace)
90       --MatchingStackIndex;
91     return MatchingStackIndex >= 0 ? &Stack[MatchingStackIndex] : nullptr;
92   };
93   for (; End->Next; End = End->Next) {
94     if (End->Next->CanBreakBefore)
95       break;
96     if (!End->Next->closesScope())
97       continue;
98     if (End->Next->MatchingParen &&
99         End->Next->MatchingParen->isOneOf(
100             tok::l_brace, TT_ArrayInitializerLSquare, tok::less)) {
101       const ParenState *State = FindParenState(End->Next->MatchingParen);
102       if (State && State->BreakBeforeClosingBrace)
103         break;
104     }
105   }
106   return End->TotalLength - Tok.TotalLength + 1;
107 }
108 
109 static unsigned getLengthToNextOperator(const FormatToken &Tok) {
110   if (!Tok.NextOperator)
111     return 0;
112   return Tok.NextOperator->TotalLength - Tok.TotalLength;
113 }
114 
115 // Returns \c true if \c Tok is the "." or "->" of a call and starts the next
116 // segment of a builder type call.
117 static bool startsSegmentOfBuilderTypeCall(const FormatToken &Tok) {
118   return Tok.isMemberAccess() && Tok.Previous && Tok.Previous->closesScope();
119 }
120 
121 // Returns \c true if \c Current starts a new parameter.
122 static bool startsNextParameter(const FormatToken &Current,
123                                 const FormatStyle &Style) {
124   const FormatToken &Previous = *Current.Previous;
125   if (Current.is(TT_CtorInitializerComma) &&
126       Style.BreakConstructorInitializers == FormatStyle::BCIS_BeforeComma)
127     return true;
128   if (Style.Language == FormatStyle::LK_Proto && Current.is(TT_SelectorName))
129     return true;
130   return Previous.is(tok::comma) && !Current.isTrailingComment() &&
131          ((Previous.isNot(TT_CtorInitializerComma) ||
132            Style.BreakConstructorInitializers !=
133                FormatStyle::BCIS_BeforeComma) &&
134           (Previous.isNot(TT_InheritanceComma) ||
135            Style.BreakInheritanceList != FormatStyle::BILS_BeforeComma));
136 }
137 
138 static bool opensProtoMessageField(const FormatToken &LessTok,
139                                    const FormatStyle &Style) {
140   if (LessTok.isNot(tok::less))
141     return false;
142   return Style.Language == FormatStyle::LK_TextProto ||
143          (Style.Language == FormatStyle::LK_Proto &&
144           (LessTok.NestingLevel > 0 ||
145            (LessTok.Previous && LessTok.Previous->is(tok::equal))));
146 }
147 
148 // Returns the delimiter of a raw string literal, or None if TokenText is not
149 // the text of a raw string literal. The delimiter could be the empty string.
150 // For example, the delimiter of R"deli(cont)deli" is deli.
151 static llvm::Optional<StringRef> getRawStringDelimiter(StringRef TokenText) {
152   if (TokenText.size() < 5 // The smallest raw string possible is 'R"()"'.
153       || !TokenText.startswith("R\"") || !TokenText.endswith("\""))
154     return None;
155 
156   // A raw string starts with 'R"<delimiter>(' and delimiter is ascii and has
157   // size at most 16 by the standard, so the first '(' must be among the first
158   // 19 bytes.
159   size_t LParenPos = TokenText.substr(0, 19).find_first_of('(');
160   if (LParenPos == StringRef::npos)
161     return None;
162   StringRef Delimiter = TokenText.substr(2, LParenPos - 2);
163 
164   // Check that the string ends in ')Delimiter"'.
165   size_t RParenPos = TokenText.size() - Delimiter.size() - 2;
166   if (TokenText[RParenPos] != ')')
167     return None;
168   if (!TokenText.substr(RParenPos + 1).startswith(Delimiter))
169     return None;
170   return Delimiter;
171 }
172 
173 // Returns the canonical delimiter for \p Language, or the empty string if no
174 // canonical delimiter is specified.
175 static StringRef
176 getCanonicalRawStringDelimiter(const FormatStyle &Style,
177                                FormatStyle::LanguageKind Language) {
178   for (const auto &Format : Style.RawStringFormats) {
179     if (Format.Language == Language)
180       return StringRef(Format.CanonicalDelimiter);
181   }
182   return "";
183 }
184 
185 RawStringFormatStyleManager::RawStringFormatStyleManager(
186     const FormatStyle &CodeStyle) {
187   for (const auto &RawStringFormat : CodeStyle.RawStringFormats) {
188     llvm::Optional<FormatStyle> LanguageStyle =
189         CodeStyle.GetLanguageStyle(RawStringFormat.Language);
190     if (!LanguageStyle) {
191       FormatStyle PredefinedStyle;
192       if (!getPredefinedStyle(RawStringFormat.BasedOnStyle,
193                               RawStringFormat.Language, &PredefinedStyle)) {
194         PredefinedStyle = getLLVMStyle();
195         PredefinedStyle.Language = RawStringFormat.Language;
196       }
197       LanguageStyle = PredefinedStyle;
198     }
199     LanguageStyle->ColumnLimit = CodeStyle.ColumnLimit;
200     for (StringRef Delimiter : RawStringFormat.Delimiters) {
201       DelimiterStyle.insert({Delimiter, *LanguageStyle});
202     }
203     for (StringRef EnclosingFunction : RawStringFormat.EnclosingFunctions) {
204       EnclosingFunctionStyle.insert({EnclosingFunction, *LanguageStyle});
205     }
206   }
207 }
208 
209 llvm::Optional<FormatStyle>
210 RawStringFormatStyleManager::getDelimiterStyle(StringRef Delimiter) const {
211   auto It = DelimiterStyle.find(Delimiter);
212   if (It == DelimiterStyle.end())
213     return None;
214   return It->second;
215 }
216 
217 llvm::Optional<FormatStyle>
218 RawStringFormatStyleManager::getEnclosingFunctionStyle(
219     StringRef EnclosingFunction) const {
220   auto It = EnclosingFunctionStyle.find(EnclosingFunction);
221   if (It == EnclosingFunctionStyle.end())
222     return None;
223   return It->second;
224 }
225 
226 ContinuationIndenter::ContinuationIndenter(const FormatStyle &Style,
227                                            const AdditionalKeywords &Keywords,
228                                            const SourceManager &SourceMgr,
229                                            WhitespaceManager &Whitespaces,
230                                            encoding::Encoding Encoding,
231                                            bool BinPackInconclusiveFunctions)
232     : Style(Style), Keywords(Keywords), SourceMgr(SourceMgr),
233       Whitespaces(Whitespaces), Encoding(Encoding),
234       BinPackInconclusiveFunctions(BinPackInconclusiveFunctions),
235       CommentPragmasRegex(Style.CommentPragmas), RawStringFormats(Style) {}
236 
237 LineState ContinuationIndenter::getInitialState(unsigned FirstIndent,
238                                                 unsigned FirstStartColumn,
239                                                 const AnnotatedLine *Line,
240                                                 bool DryRun) {
241   LineState State;
242   State.FirstIndent = FirstIndent;
243   if (FirstStartColumn && Line->First->NewlinesBefore == 0)
244     State.Column = FirstStartColumn;
245   else
246     State.Column = FirstIndent;
247   // With preprocessor directive indentation, the line starts on column 0
248   // since it's indented after the hash, but FirstIndent is set to the
249   // preprocessor indent.
250   if (Style.IndentPPDirectives == FormatStyle::PPDIS_AfterHash &&
251       (Line->Type == LT_PreprocessorDirective ||
252        Line->Type == LT_ImportStatement))
253     State.Column = 0;
254   State.Line = Line;
255   State.NextToken = Line->First;
256   State.Stack.push_back(ParenState(/*Tok=*/nullptr, FirstIndent, FirstIndent,
257                                    /*AvoidBinPacking=*/false,
258                                    /*NoLineBreak=*/false));
259   State.LineContainsContinuedForLoopSection = false;
260   State.NoContinuation = false;
261   State.StartOfStringLiteral = 0;
262   State.StartOfLineLevel = 0;
263   State.LowestLevelOnLine = 0;
264   State.IgnoreStackForComparison = false;
265 
266   if (Style.Language == FormatStyle::LK_TextProto) {
267     // We need this in order to deal with the bin packing of text fields at
268     // global scope.
269     State.Stack.back().AvoidBinPacking = true;
270     State.Stack.back().BreakBeforeParameter = true;
271     State.Stack.back().AlignColons = false;
272   }
273 
274   // The first token has already been indented and thus consumed.
275   moveStateToNextToken(State, DryRun, /*Newline=*/false);
276   return State;
277 }
278 
279 bool ContinuationIndenter::canBreak(const LineState &State) {
280   const FormatToken &Current = *State.NextToken;
281   const FormatToken &Previous = *Current.Previous;
282   assert(&Previous == Current.Previous);
283   if (!Current.CanBreakBefore && !(State.Stack.back().BreakBeforeClosingBrace &&
284                                    Current.closesBlockOrBlockTypeList(Style)))
285     return false;
286   // The opening "{" of a braced list has to be on the same line as the first
287   // element if it is nested in another braced init list or function call.
288   if (!Current.MustBreakBefore && Previous.is(tok::l_brace) &&
289       Previous.isNot(TT_DictLiteral) && Previous.is(BK_BracedInit) &&
290       Previous.Previous &&
291       Previous.Previous->isOneOf(tok::l_brace, tok::l_paren, tok::comma))
292     return false;
293   // This prevents breaks like:
294   //   ...
295   //   SomeParameter, OtherParameter).DoSomething(
296   //   ...
297   // As they hide "DoSomething" and are generally bad for readability.
298   if (Previous.opensScope() && Previous.isNot(tok::l_brace) &&
299       State.LowestLevelOnLine < State.StartOfLineLevel &&
300       State.LowestLevelOnLine < Current.NestingLevel)
301     return false;
302   if (Current.isMemberAccess() && State.Stack.back().ContainsUnwrappedBuilder)
303     return false;
304 
305   // Don't create a 'hanging' indent if there are multiple blocks in a single
306   // statement.
307   if (Previous.is(tok::l_brace) && State.Stack.size() > 1 &&
308       State.Stack[State.Stack.size() - 2].NestedBlockInlined &&
309       State.Stack[State.Stack.size() - 2].HasMultipleNestedBlocks)
310     return false;
311 
312   // Don't break after very short return types (e.g. "void") as that is often
313   // unexpected.
314   if (Current.is(TT_FunctionDeclarationName) && State.Column < 6) {
315     if (Style.AlwaysBreakAfterReturnType == FormatStyle::RTBS_None)
316       return false;
317   }
318 
319   // If binary operators are moved to the next line (including commas for some
320   // styles of constructor initializers), that's always ok.
321   if (!Current.isOneOf(TT_BinaryOperator, tok::comma) &&
322       State.Stack.back().NoLineBreakInOperand)
323     return false;
324 
325   if (Previous.is(tok::l_square) && Previous.is(TT_ObjCMethodExpr))
326     return false;
327 
328   return !State.Stack.back().NoLineBreak;
329 }
330 
331 bool ContinuationIndenter::mustBreak(const LineState &State) {
332   const FormatToken &Current = *State.NextToken;
333   const FormatToken &Previous = *Current.Previous;
334   if (Style.BraceWrapping.BeforeLambdaBody && Current.CanBreakBefore &&
335       Current.is(TT_LambdaLBrace) && Previous.isNot(TT_LineComment)) {
336     auto LambdaBodyLength = getLengthToMatchingParen(Current, State.Stack);
337     return (LambdaBodyLength > getColumnLimit(State));
338   }
339   if (Current.MustBreakBefore || Current.is(TT_InlineASMColon))
340     return true;
341   if (State.Stack.back().BreakBeforeClosingBrace &&
342       Current.closesBlockOrBlockTypeList(Style))
343     return true;
344   if (Previous.is(tok::semi) && State.LineContainsContinuedForLoopSection)
345     return true;
346   if (Style.Language == FormatStyle::LK_ObjC &&
347       Style.ObjCBreakBeforeNestedBlockParam &&
348       Current.ObjCSelectorNameParts > 1 &&
349       Current.startsSequence(TT_SelectorName, tok::colon, tok::caret)) {
350     return true;
351   }
352   // Avoid producing inconsistent states by requiring breaks where they are not
353   // permitted for C# generic type constraints.
354   if (State.Stack.back().IsCSharpGenericTypeConstraint &&
355       Previous.isNot(TT_CSharpGenericTypeConstraintComma))
356     return false;
357   if ((startsNextParameter(Current, Style) || Previous.is(tok::semi) ||
358        (Previous.is(TT_TemplateCloser) && Current.is(TT_StartOfName) &&
359         Style.isCpp() &&
360         // FIXME: This is a temporary workaround for the case where clang-format
361         // sets BreakBeforeParameter to avoid bin packing and this creates a
362         // completely unnecessary line break after a template type that isn't
363         // line-wrapped.
364         (Previous.NestingLevel == 1 || Style.BinPackParameters)) ||
365        (Style.BreakBeforeTernaryOperators && Current.is(TT_ConditionalExpr) &&
366         Previous.isNot(tok::question)) ||
367        (!Style.BreakBeforeTernaryOperators &&
368         Previous.is(TT_ConditionalExpr))) &&
369       State.Stack.back().BreakBeforeParameter && !Current.isTrailingComment() &&
370       !Current.isOneOf(tok::r_paren, tok::r_brace))
371     return true;
372   if (State.Stack.back().IsChainedConditional &&
373       ((Style.BreakBeforeTernaryOperators && Current.is(TT_ConditionalExpr) &&
374         Current.is(tok::colon)) ||
375        (!Style.BreakBeforeTernaryOperators && Previous.is(TT_ConditionalExpr) &&
376         Previous.is(tok::colon))))
377     return true;
378   if (((Previous.is(TT_DictLiteral) && Previous.is(tok::l_brace)) ||
379        (Previous.is(TT_ArrayInitializerLSquare) &&
380         Previous.ParameterCount > 1) ||
381        opensProtoMessageField(Previous, Style)) &&
382       Style.ColumnLimit > 0 &&
383       getLengthToMatchingParen(Previous, State.Stack) + State.Column - 1 >
384           getColumnLimit(State))
385     return true;
386 
387   const FormatToken &BreakConstructorInitializersToken =
388       Style.BreakConstructorInitializers == FormatStyle::BCIS_AfterColon
389           ? Previous
390           : Current;
391   if (BreakConstructorInitializersToken.is(TT_CtorInitializerColon) &&
392       (State.Column + State.Line->Last->TotalLength - Previous.TotalLength >
393            getColumnLimit(State) ||
394        State.Stack.back().BreakBeforeParameter) &&
395       (Style.AllowShortFunctionsOnASingleLine != FormatStyle::SFS_All ||
396        Style.BreakConstructorInitializers != FormatStyle::BCIS_BeforeColon ||
397        Style.ColumnLimit != 0))
398     return true;
399 
400   if (Current.is(TT_ObjCMethodExpr) && !Previous.is(TT_SelectorName) &&
401       State.Line->startsWith(TT_ObjCMethodSpecifier))
402     return true;
403   if (Current.is(TT_SelectorName) && !Previous.is(tok::at) &&
404       State.Stack.back().ObjCSelectorNameFound &&
405       State.Stack.back().BreakBeforeParameter &&
406       (Style.ObjCBreakBeforeNestedBlockParam ||
407        !Current.startsSequence(TT_SelectorName, tok::colon, tok::caret)))
408     return true;
409 
410   unsigned NewLineColumn = getNewLineColumn(State);
411   if (Current.isMemberAccess() && Style.ColumnLimit != 0 &&
412       State.Column + getLengthToNextOperator(Current) > Style.ColumnLimit &&
413       (State.Column > NewLineColumn ||
414        Current.NestingLevel < State.StartOfLineLevel))
415     return true;
416 
417   if (startsSegmentOfBuilderTypeCall(Current) &&
418       (State.Stack.back().CallContinuation != 0 ||
419        State.Stack.back().BreakBeforeParameter) &&
420       // JavaScript is treated different here as there is a frequent pattern:
421       //   SomeFunction(function() {
422       //     ...
423       //   }.bind(...));
424       // FIXME: We should find a more generic solution to this problem.
425       !(State.Column <= NewLineColumn && Style.isJavaScript()) &&
426       !(Previous.closesScopeAfterBlock() && State.Column <= NewLineColumn))
427     return true;
428 
429   // If the template declaration spans multiple lines, force wrap before the
430   // function/class declaration
431   if (Previous.ClosesTemplateDeclaration &&
432       State.Stack.back().BreakBeforeParameter && Current.CanBreakBefore)
433     return true;
434 
435   if (!State.Line->First->is(tok::kw_enum) && State.Column <= NewLineColumn)
436     return false;
437 
438   if (Style.AlwaysBreakBeforeMultilineStrings &&
439       (NewLineColumn == State.FirstIndent + Style.ContinuationIndentWidth ||
440        Previous.is(tok::comma) || Current.NestingLevel < 2) &&
441       !Previous.isOneOf(tok::kw_return, tok::lessless, tok::at,
442                         Keywords.kw_dollar) &&
443       !Previous.isOneOf(TT_InlineASMColon, TT_ConditionalExpr) &&
444       nextIsMultilineString(State))
445     return true;
446 
447   // Using CanBreakBefore here and below takes care of the decision whether the
448   // current style uses wrapping before or after operators for the given
449   // operator.
450   if (Previous.is(TT_BinaryOperator) && Current.CanBreakBefore) {
451     // If we need to break somewhere inside the LHS of a binary expression, we
452     // should also break after the operator. Otherwise, the formatting would
453     // hide the operator precedence, e.g. in:
454     //   if (aaaaaaaaaaaaaa ==
455     //           bbbbbbbbbbbbbb && c) {..
456     // For comparisons, we only apply this rule, if the LHS is a binary
457     // expression itself as otherwise, the line breaks seem superfluous.
458     // We need special cases for ">>" which we have split into two ">" while
459     // lexing in order to make template parsing easier.
460     bool IsComparison = (Previous.getPrecedence() == prec::Relational ||
461                          Previous.getPrecedence() == prec::Equality ||
462                          Previous.getPrecedence() == prec::Spaceship) &&
463                         Previous.Previous &&
464                         Previous.Previous->isNot(TT_BinaryOperator); // For >>.
465     bool LHSIsBinaryExpr =
466         Previous.Previous && Previous.Previous->EndsBinaryExpression;
467     if ((!IsComparison || LHSIsBinaryExpr) && !Current.isTrailingComment() &&
468         Previous.getPrecedence() != prec::Assignment &&
469         State.Stack.back().BreakBeforeParameter)
470       return true;
471   } else if (Current.is(TT_BinaryOperator) && Current.CanBreakBefore &&
472              State.Stack.back().BreakBeforeParameter) {
473     return true;
474   }
475 
476   // Same as above, but for the first "<<" operator.
477   if (Current.is(tok::lessless) && Current.isNot(TT_OverloadedOperator) &&
478       State.Stack.back().BreakBeforeParameter &&
479       State.Stack.back().FirstLessLess == 0)
480     return true;
481 
482   if (Current.NestingLevel == 0 && !Current.isTrailingComment()) {
483     // Always break after "template <...>" and leading annotations. This is only
484     // for cases where the entire line does not fit on a single line as a
485     // different LineFormatter would be used otherwise.
486     if (Previous.ClosesTemplateDeclaration)
487       return Style.AlwaysBreakTemplateDeclarations != FormatStyle::BTDS_No;
488     if (Previous.is(TT_FunctionAnnotationRParen))
489       return true;
490     if (Previous.is(TT_LeadingJavaAnnotation) && Current.isNot(tok::l_paren) &&
491         Current.isNot(TT_LeadingJavaAnnotation))
492       return true;
493   }
494 
495   if (Style.isJavaScript() && Previous.is(tok::r_paren) &&
496       Previous.is(TT_JavaAnnotation)) {
497     // Break after the closing parenthesis of TypeScript decorators before
498     // functions, getters and setters.
499     static const llvm::StringSet<> BreakBeforeDecoratedTokens = {"get", "set",
500                                                                  "function"};
501     if (BreakBeforeDecoratedTokens.contains(Current.TokenText))
502       return true;
503   }
504 
505   // If the return type spans multiple lines, wrap before the function name.
506   if (((Current.is(TT_FunctionDeclarationName) &&
507         // Don't break before a C# function when no break after return type
508         (!Style.isCSharp() ||
509          Style.AlwaysBreakAfterReturnType != FormatStyle::RTBS_None) &&
510         // Don't always break between a JavaScript `function` and the function
511         // name.
512         !Style.isJavaScript()) ||
513        (Current.is(tok::kw_operator) && !Previous.is(tok::coloncolon))) &&
514       !Previous.is(tok::kw_template) && State.Stack.back().BreakBeforeParameter)
515     return true;
516 
517   // The following could be precomputed as they do not depend on the state.
518   // However, as they should take effect only if the UnwrappedLine does not fit
519   // into the ColumnLimit, they are checked here in the ContinuationIndenter.
520   if (Style.ColumnLimit != 0 && Previous.is(BK_Block) &&
521       Previous.is(tok::l_brace) && !Current.isOneOf(tok::r_brace, tok::comment))
522     return true;
523 
524   if (Current.is(tok::lessless) &&
525       ((Previous.is(tok::identifier) && Previous.TokenText == "endl") ||
526        (Previous.Tok.isLiteral() && (Previous.TokenText.endswith("\\n\"") ||
527                                      Previous.TokenText == "\'\\n\'"))))
528     return true;
529 
530   if (Previous.is(TT_BlockComment) && Previous.IsMultiline)
531     return true;
532 
533   if (State.NoContinuation)
534     return true;
535 
536   return false;
537 }
538 
539 unsigned ContinuationIndenter::addTokenToState(LineState &State, bool Newline,
540                                                bool DryRun,
541                                                unsigned ExtraSpaces) {
542   const FormatToken &Current = *State.NextToken;
543 
544   assert(!State.Stack.empty());
545   State.NoContinuation = false;
546 
547   if ((Current.is(TT_ImplicitStringLiteral) &&
548        (Current.Previous->Tok.getIdentifierInfo() == nullptr ||
549         Current.Previous->Tok.getIdentifierInfo()->getPPKeywordID() ==
550             tok::pp_not_keyword))) {
551     unsigned EndColumn =
552         SourceMgr.getSpellingColumnNumber(Current.WhitespaceRange.getEnd());
553     if (Current.LastNewlineOffset != 0) {
554       // If there is a newline within this token, the final column will solely
555       // determined by the current end column.
556       State.Column = EndColumn;
557     } else {
558       unsigned StartColumn =
559           SourceMgr.getSpellingColumnNumber(Current.WhitespaceRange.getBegin());
560       assert(EndColumn >= StartColumn);
561       State.Column += EndColumn - StartColumn;
562     }
563     moveStateToNextToken(State, DryRun, /*Newline=*/false);
564     return 0;
565   }
566 
567   unsigned Penalty = 0;
568   if (Newline)
569     Penalty = addTokenOnNewLine(State, DryRun);
570   else
571     addTokenOnCurrentLine(State, DryRun, ExtraSpaces);
572 
573   return moveStateToNextToken(State, DryRun, Newline) + Penalty;
574 }
575 
576 void ContinuationIndenter::addTokenOnCurrentLine(LineState &State, bool DryRun,
577                                                  unsigned ExtraSpaces) {
578   FormatToken &Current = *State.NextToken;
579   const FormatToken &Previous = *State.NextToken->Previous;
580   if (Current.is(tok::equal) &&
581       (State.Line->First->is(tok::kw_for) || Current.NestingLevel == 0) &&
582       State.Stack.back().VariablePos == 0) {
583     State.Stack.back().VariablePos = State.Column;
584     // Move over * and & if they are bound to the variable name.
585     const FormatToken *Tok = &Previous;
586     while (Tok && State.Stack.back().VariablePos >= Tok->ColumnWidth) {
587       State.Stack.back().VariablePos -= Tok->ColumnWidth;
588       if (Tok->SpacesRequiredBefore != 0)
589         break;
590       Tok = Tok->Previous;
591     }
592     if (Previous.PartOfMultiVariableDeclStmt)
593       State.Stack.back().LastSpace = State.Stack.back().VariablePos;
594   }
595 
596   unsigned Spaces = Current.SpacesRequiredBefore + ExtraSpaces;
597 
598   // Indent preprocessor directives after the hash if required.
599   int PPColumnCorrection = 0;
600   if (Style.IndentPPDirectives == FormatStyle::PPDIS_AfterHash &&
601       Previous.is(tok::hash) && State.FirstIndent > 0 &&
602       (State.Line->Type == LT_PreprocessorDirective ||
603        State.Line->Type == LT_ImportStatement)) {
604     Spaces += State.FirstIndent;
605 
606     // For preprocessor indent with tabs, State.Column will be 1 because of the
607     // hash. This causes second-level indents onward to have an extra space
608     // after the tabs. We avoid this misalignment by subtracting 1 from the
609     // column value passed to replaceWhitespace().
610     if (Style.UseTab != FormatStyle::UT_Never)
611       PPColumnCorrection = -1;
612   }
613 
614   if (!DryRun)
615     Whitespaces.replaceWhitespace(Current, /*Newlines=*/0, Spaces,
616                                   State.Column + Spaces + PPColumnCorrection);
617 
618   // If "BreakBeforeInheritanceComma" mode, don't break within the inheritance
619   // declaration unless there is multiple inheritance.
620   if (Style.BreakInheritanceList == FormatStyle::BILS_BeforeComma &&
621       Current.is(TT_InheritanceColon))
622     State.Stack.back().NoLineBreak = true;
623   if (Style.BreakInheritanceList == FormatStyle::BILS_AfterColon &&
624       Previous.is(TT_InheritanceColon))
625     State.Stack.back().NoLineBreak = true;
626 
627   if (Current.is(TT_SelectorName) &&
628       !State.Stack.back().ObjCSelectorNameFound) {
629     unsigned MinIndent =
630         std::max(State.FirstIndent + Style.ContinuationIndentWidth,
631                  State.Stack.back().Indent);
632     unsigned FirstColonPos = State.Column + Spaces + Current.ColumnWidth;
633     if (Current.LongestObjCSelectorName == 0)
634       State.Stack.back().AlignColons = false;
635     else if (MinIndent + Current.LongestObjCSelectorName > FirstColonPos)
636       State.Stack.back().ColonPos = MinIndent + Current.LongestObjCSelectorName;
637     else
638       State.Stack.back().ColonPos = FirstColonPos;
639   }
640 
641   // In "AlwaysBreak" mode, enforce wrapping directly after the parenthesis by
642   // disallowing any further line breaks if there is no line break after the
643   // opening parenthesis. Don't break if it doesn't conserve columns.
644   if (Style.AlignAfterOpenBracket == FormatStyle::BAS_AlwaysBreak &&
645       (Previous.isOneOf(tok::l_paren, TT_TemplateOpener, tok::l_square) ||
646        (Previous.is(tok::l_brace) && Previous.isNot(BK_Block) &&
647         Style.Cpp11BracedListStyle)) &&
648       State.Column > getNewLineColumn(State) &&
649       (!Previous.Previous || !Previous.Previous->isOneOf(
650                                  tok::kw_for, tok::kw_while, tok::kw_switch)) &&
651       // Don't do this for simple (no expressions) one-argument function calls
652       // as that feels like needlessly wasting whitespace, e.g.:
653       //
654       //   caaaaaaaaaaaall(
655       //       caaaaaaaaaaaall(
656       //           caaaaaaaaaaaall(
657       //               caaaaaaaaaaaaaaaaaaaaaaall(aaaaaaaaaaaaaa, aaaaaaaaa))));
658       Current.FakeLParens.size() > 0 &&
659       Current.FakeLParens.back() > prec::Unknown)
660     State.Stack.back().NoLineBreak = true;
661   if (Previous.is(TT_TemplateString) && Previous.opensScope())
662     State.Stack.back().NoLineBreak = true;
663 
664   if (Style.AlignAfterOpenBracket != FormatStyle::BAS_DontAlign &&
665       !State.Stack.back().IsCSharpGenericTypeConstraint &&
666       Previous.opensScope() && Previous.isNot(TT_ObjCMethodExpr) &&
667       (Current.isNot(TT_LineComment) || Previous.is(BK_BracedInit))) {
668     State.Stack.back().Indent = State.Column + Spaces;
669     State.Stack.back().IsAligned = true;
670   }
671   if (State.Stack.back().AvoidBinPacking && startsNextParameter(Current, Style))
672     State.Stack.back().NoLineBreak = true;
673   if (startsSegmentOfBuilderTypeCall(Current) &&
674       State.Column > getNewLineColumn(State))
675     State.Stack.back().ContainsUnwrappedBuilder = true;
676 
677   if (Current.is(TT_LambdaArrow) && Style.Language == FormatStyle::LK_Java)
678     State.Stack.back().NoLineBreak = true;
679   if (Current.isMemberAccess() && Previous.is(tok::r_paren) &&
680       (Previous.MatchingParen &&
681        (Previous.TotalLength - Previous.MatchingParen->TotalLength > 10)))
682     // If there is a function call with long parameters, break before trailing
683     // calls. This prevents things like:
684     //   EXPECT_CALL(SomeLongParameter).Times(
685     //       2);
686     // We don't want to do this for short parameters as they can just be
687     // indexes.
688     State.Stack.back().NoLineBreak = true;
689 
690   // Don't allow the RHS of an operator to be split over multiple lines unless
691   // there is a line-break right after the operator.
692   // Exclude relational operators, as there, it is always more desirable to
693   // have the LHS 'left' of the RHS.
694   const FormatToken *P = Current.getPreviousNonComment();
695   if (!Current.is(tok::comment) && P &&
696       (P->isOneOf(TT_BinaryOperator, tok::comma) ||
697        (P->is(TT_ConditionalExpr) && P->is(tok::colon))) &&
698       !P->isOneOf(TT_OverloadedOperator, TT_CtorInitializerComma) &&
699       P->getPrecedence() != prec::Assignment &&
700       P->getPrecedence() != prec::Relational &&
701       P->getPrecedence() != prec::Spaceship) {
702     bool BreakBeforeOperator =
703         P->MustBreakBefore || P->is(tok::lessless) ||
704         (P->is(TT_BinaryOperator) &&
705          Style.BreakBeforeBinaryOperators != FormatStyle::BOS_None) ||
706         (P->is(TT_ConditionalExpr) && Style.BreakBeforeTernaryOperators);
707     // Don't do this if there are only two operands. In these cases, there is
708     // always a nice vertical separation between them and the extra line break
709     // does not help.
710     bool HasTwoOperands =
711         P->OperatorIndex == 0 && !P->NextOperator && !P->is(TT_ConditionalExpr);
712     if ((!BreakBeforeOperator &&
713          !(HasTwoOperands &&
714            Style.AlignOperands != FormatStyle::OAS_DontAlign)) ||
715         (!State.Stack.back().LastOperatorWrapped && BreakBeforeOperator))
716       State.Stack.back().NoLineBreakInOperand = true;
717   }
718 
719   State.Column += Spaces;
720   if (Current.isNot(tok::comment) && Previous.is(tok::l_paren) &&
721       Previous.Previous &&
722       (Previous.Previous->is(tok::kw_for) || Previous.Previous->isIf())) {
723     // Treat the condition inside an if as if it was a second function
724     // parameter, i.e. let nested calls have a continuation indent.
725     State.Stack.back().LastSpace = State.Column;
726     State.Stack.back().NestedBlockIndent = State.Column;
727   } else if (!Current.isOneOf(tok::comment, tok::caret) &&
728              ((Previous.is(tok::comma) &&
729                !Previous.is(TT_OverloadedOperator)) ||
730               (Previous.is(tok::colon) && Previous.is(TT_ObjCMethodExpr)))) {
731     State.Stack.back().LastSpace = State.Column;
732   } else if (Previous.is(TT_CtorInitializerColon) &&
733              Style.BreakConstructorInitializers ==
734                  FormatStyle::BCIS_AfterColon) {
735     State.Stack.back().Indent = State.Column;
736     State.Stack.back().LastSpace = State.Column;
737   } else if ((Previous.isOneOf(TT_BinaryOperator, TT_ConditionalExpr,
738                                TT_CtorInitializerColon)) &&
739              ((Previous.getPrecedence() != prec::Assignment &&
740                (Previous.isNot(tok::lessless) || Previous.OperatorIndex != 0 ||
741                 Previous.NextOperator)) ||
742               Current.StartsBinaryExpression)) {
743     // Indent relative to the RHS of the expression unless this is a simple
744     // assignment without binary expression on the RHS. Also indent relative to
745     // unary operators and the colons of constructor initializers.
746     if (Style.BreakBeforeBinaryOperators == FormatStyle::BOS_None)
747       State.Stack.back().LastSpace = State.Column;
748   } else if (Previous.is(TT_InheritanceColon)) {
749     State.Stack.back().Indent = State.Column;
750     State.Stack.back().LastSpace = State.Column;
751   } else if (Current.is(TT_CSharpGenericTypeConstraintColon)) {
752     State.Stack.back().ColonPos = State.Column;
753   } else if (Previous.opensScope()) {
754     // If a function has a trailing call, indent all parameters from the
755     // opening parenthesis. This avoids confusing indents like:
756     //   OuterFunction(InnerFunctionCall( // break
757     //       ParameterToInnerFunction))   // break
758     //       .SecondInnerFunctionCall();
759     bool HasTrailingCall = false;
760     if (Previous.MatchingParen) {
761       const FormatToken *Next = Previous.MatchingParen->getNextNonComment();
762       HasTrailingCall = Next && Next->isMemberAccess();
763     }
764     if (HasTrailingCall && State.Stack.size() > 1 &&
765         State.Stack[State.Stack.size() - 2].CallContinuation == 0)
766       State.Stack.back().LastSpace = State.Column;
767   }
768 }
769 
770 unsigned ContinuationIndenter::addTokenOnNewLine(LineState &State,
771                                                  bool DryRun) {
772   FormatToken &Current = *State.NextToken;
773   const FormatToken &Previous = *State.NextToken->Previous;
774 
775   // Extra penalty that needs to be added because of the way certain line
776   // breaks are chosen.
777   unsigned Penalty = 0;
778 
779   const FormatToken *PreviousNonComment = Current.getPreviousNonComment();
780   const FormatToken *NextNonComment = Previous.getNextNonComment();
781   if (!NextNonComment)
782     NextNonComment = &Current;
783   // The first line break on any NestingLevel causes an extra penalty in order
784   // prefer similar line breaks.
785   if (!State.Stack.back().ContainsLineBreak)
786     Penalty += 15;
787   State.Stack.back().ContainsLineBreak = true;
788 
789   Penalty += State.NextToken->SplitPenalty;
790 
791   // Breaking before the first "<<" is generally not desirable if the LHS is
792   // short. Also always add the penalty if the LHS is split over multiple lines
793   // to avoid unnecessary line breaks that just work around this penalty.
794   if (NextNonComment->is(tok::lessless) &&
795       State.Stack.back().FirstLessLess == 0 &&
796       (State.Column <= Style.ColumnLimit / 3 ||
797        State.Stack.back().BreakBeforeParameter))
798     Penalty += Style.PenaltyBreakFirstLessLess;
799 
800   State.Column = getNewLineColumn(State);
801 
802   // Add Penalty proportional to amount of whitespace away from FirstColumn
803   // This tends to penalize several lines that are far-right indented,
804   // and prefers a line-break prior to such a block, e.g:
805   //
806   // Constructor() :
807   //   member(value), looooooooooooooooong_member(
808   //                      looooooooooong_call(param_1, param_2, param_3))
809   // would then become
810   // Constructor() :
811   //   member(value),
812   //   looooooooooooooooong_member(
813   //       looooooooooong_call(param_1, param_2, param_3))
814   if (State.Column > State.FirstIndent)
815     Penalty +=
816         Style.PenaltyIndentedWhitespace * (State.Column - State.FirstIndent);
817 
818   // Indent nested blocks relative to this column, unless in a very specific
819   // JavaScript special case where:
820   //
821   //   var loooooong_name =
822   //       function() {
823   //     // code
824   //   }
825   //
826   // is common and should be formatted like a free-standing function. The same
827   // goes for wrapping before the lambda return type arrow.
828   if (!Current.is(TT_LambdaArrow) &&
829       (!Style.isJavaScript() || Current.NestingLevel != 0 ||
830        !PreviousNonComment || !PreviousNonComment->is(tok::equal) ||
831        !Current.isOneOf(Keywords.kw_async, Keywords.kw_function)))
832     State.Stack.back().NestedBlockIndent = State.Column;
833 
834   if (NextNonComment->isMemberAccess()) {
835     if (State.Stack.back().CallContinuation == 0)
836       State.Stack.back().CallContinuation = State.Column;
837   } else if (NextNonComment->is(TT_SelectorName)) {
838     if (!State.Stack.back().ObjCSelectorNameFound) {
839       if (NextNonComment->LongestObjCSelectorName == 0) {
840         State.Stack.back().AlignColons = false;
841       } else {
842         State.Stack.back().ColonPos =
843             (shouldIndentWrappedSelectorName(Style, State.Line->Type)
844                  ? std::max(State.Stack.back().Indent,
845                             State.FirstIndent + Style.ContinuationIndentWidth)
846                  : State.Stack.back().Indent) +
847             std::max(NextNonComment->LongestObjCSelectorName,
848                      NextNonComment->ColumnWidth);
849       }
850     } else if (State.Stack.back().AlignColons &&
851                State.Stack.back().ColonPos <= NextNonComment->ColumnWidth) {
852       State.Stack.back().ColonPos = State.Column + NextNonComment->ColumnWidth;
853     }
854   } else if (PreviousNonComment && PreviousNonComment->is(tok::colon) &&
855              PreviousNonComment->isOneOf(TT_ObjCMethodExpr, TT_DictLiteral)) {
856     // FIXME: This is hacky, find a better way. The problem is that in an ObjC
857     // method expression, the block should be aligned to the line starting it,
858     // e.g.:
859     //   [aaaaaaaaaaaaaaa aaaaaaaaa: \\ break for some reason
860     //                        ^(int *i) {
861     //                            // ...
862     //                        }];
863     // Thus, we set LastSpace of the next higher NestingLevel, to which we move
864     // when we consume all of the "}"'s FakeRParens at the "{".
865     if (State.Stack.size() > 1)
866       State.Stack[State.Stack.size() - 2].LastSpace =
867           std::max(State.Stack.back().LastSpace, State.Stack.back().Indent) +
868           Style.ContinuationIndentWidth;
869   }
870 
871   if ((PreviousNonComment &&
872        PreviousNonComment->isOneOf(tok::comma, tok::semi) &&
873        !State.Stack.back().AvoidBinPacking) ||
874       Previous.is(TT_BinaryOperator))
875     State.Stack.back().BreakBeforeParameter = false;
876   if (PreviousNonComment &&
877       PreviousNonComment->isOneOf(TT_TemplateCloser, TT_JavaAnnotation) &&
878       Current.NestingLevel == 0)
879     State.Stack.back().BreakBeforeParameter = false;
880   if (NextNonComment->is(tok::question) ||
881       (PreviousNonComment && PreviousNonComment->is(tok::question)))
882     State.Stack.back().BreakBeforeParameter = true;
883   if (Current.is(TT_BinaryOperator) && Current.CanBreakBefore)
884     State.Stack.back().BreakBeforeParameter = false;
885 
886   if (!DryRun) {
887     unsigned MaxEmptyLinesToKeep = Style.MaxEmptyLinesToKeep + 1;
888     if (Current.is(tok::r_brace) && Current.MatchingParen &&
889         // Only strip trailing empty lines for l_braces that have children, i.e.
890         // for function expressions (lambdas, arrows, etc).
891         !Current.MatchingParen->Children.empty()) {
892       // lambdas and arrow functions are expressions, thus their r_brace is not
893       // on its own line, and thus not covered by UnwrappedLineFormatter's logic
894       // about removing empty lines on closing blocks. Special case them here.
895       MaxEmptyLinesToKeep = 1;
896     }
897     unsigned Newlines =
898         std::max(1u, std::min(Current.NewlinesBefore, MaxEmptyLinesToKeep));
899     bool ContinuePPDirective =
900         State.Line->InPPDirective && State.Line->Type != LT_ImportStatement;
901     Whitespaces.replaceWhitespace(Current, Newlines, State.Column, State.Column,
902                                   State.Stack.back().IsAligned,
903                                   ContinuePPDirective);
904   }
905 
906   if (!Current.isTrailingComment())
907     State.Stack.back().LastSpace = State.Column;
908   if (Current.is(tok::lessless))
909     // If we are breaking before a "<<", we always want to indent relative to
910     // RHS. This is necessary only for "<<", as we special-case it and don't
911     // always indent relative to the RHS.
912     State.Stack.back().LastSpace += 3; // 3 -> width of "<< ".
913 
914   State.StartOfLineLevel = Current.NestingLevel;
915   State.LowestLevelOnLine = Current.NestingLevel;
916 
917   // Any break on this level means that the parent level has been broken
918   // and we need to avoid bin packing there.
919   bool NestedBlockSpecialCase =
920       (!Style.isCpp() && Current.is(tok::r_brace) && State.Stack.size() > 1 &&
921        State.Stack[State.Stack.size() - 2].NestedBlockInlined) ||
922       (Style.Language == FormatStyle::LK_ObjC && Current.is(tok::r_brace) &&
923        State.Stack.size() > 1 && !Style.ObjCBreakBeforeNestedBlockParam);
924   if (!NestedBlockSpecialCase)
925     for (unsigned i = 0, e = State.Stack.size() - 1; i != e; ++i)
926       State.Stack[i].BreakBeforeParameter = true;
927 
928   if (PreviousNonComment &&
929       !PreviousNonComment->isOneOf(tok::comma, tok::colon, tok::semi) &&
930       (PreviousNonComment->isNot(TT_TemplateCloser) ||
931        Current.NestingLevel != 0) &&
932       !PreviousNonComment->isOneOf(
933           TT_BinaryOperator, TT_FunctionAnnotationRParen, TT_JavaAnnotation,
934           TT_LeadingJavaAnnotation) &&
935       Current.isNot(TT_BinaryOperator) && !PreviousNonComment->opensScope())
936     State.Stack.back().BreakBeforeParameter = true;
937 
938   // If we break after { or the [ of an array initializer, we should also break
939   // before the corresponding } or ].
940   if (PreviousNonComment &&
941       (PreviousNonComment->isOneOf(tok::l_brace, TT_ArrayInitializerLSquare) ||
942        opensProtoMessageField(*PreviousNonComment, Style)))
943     State.Stack.back().BreakBeforeClosingBrace = true;
944 
945   if (State.Stack.back().AvoidBinPacking) {
946     // If we are breaking after '(', '{', '<', or this is the break after a ':'
947     // to start a member initializater list in a constructor, this should not
948     // be considered bin packing unless the relevant AllowAll option is false or
949     // this is a dict/object literal.
950     bool PreviousIsBreakingCtorInitializerColon =
951         Previous.is(TT_CtorInitializerColon) &&
952         Style.BreakConstructorInitializers == FormatStyle::BCIS_AfterColon;
953     if (!(Previous.isOneOf(tok::l_paren, tok::l_brace, TT_BinaryOperator) ||
954           PreviousIsBreakingCtorInitializerColon) ||
955         (!Style.AllowAllParametersOfDeclarationOnNextLine &&
956          State.Line->MustBeDeclaration) ||
957         (!Style.AllowAllArgumentsOnNextLine &&
958          !State.Line->MustBeDeclaration) ||
959         (Style.PackConstructorInitializers != FormatStyle::PCIS_NextLine &&
960          PreviousIsBreakingCtorInitializerColon) ||
961         Previous.is(TT_DictLiteral))
962       State.Stack.back().BreakBeforeParameter = true;
963 
964     // If we are breaking after a ':' to start a member initializer list,
965     // and we allow all arguments on the next line, we should not break
966     // before the next parameter.
967     if (PreviousIsBreakingCtorInitializerColon &&
968         Style.PackConstructorInitializers == FormatStyle::PCIS_NextLine)
969       State.Stack.back().BreakBeforeParameter = false;
970   }
971 
972   return Penalty;
973 }
974 
975 unsigned ContinuationIndenter::getNewLineColumn(const LineState &State) {
976   if (!State.NextToken || !State.NextToken->Previous)
977     return 0;
978 
979   FormatToken &Current = *State.NextToken;
980 
981   if (State.Stack.back().IsCSharpGenericTypeConstraint &&
982       Current.isNot(TT_CSharpGenericTypeConstraint))
983     return State.Stack.back().ColonPos + 2;
984 
985   const FormatToken &Previous = *Current.Previous;
986   // If we are continuing an expression, we want to use the continuation indent.
987   unsigned ContinuationIndent =
988       std::max(State.Stack.back().LastSpace, State.Stack.back().Indent) +
989       Style.ContinuationIndentWidth;
990   const FormatToken *PreviousNonComment = Current.getPreviousNonComment();
991   const FormatToken *NextNonComment = Previous.getNextNonComment();
992   if (!NextNonComment)
993     NextNonComment = &Current;
994 
995   // Java specific bits.
996   if (Style.Language == FormatStyle::LK_Java &&
997       Current.isOneOf(Keywords.kw_implements, Keywords.kw_extends))
998     return std::max(State.Stack.back().LastSpace,
999                     State.Stack.back().Indent + Style.ContinuationIndentWidth);
1000 
1001   if (Style.BreakBeforeBraces == FormatStyle::BS_Whitesmiths &&
1002       State.Line->First->is(tok::kw_enum))
1003     return (Style.IndentWidth * State.Line->First->IndentLevel) +
1004            Style.IndentWidth;
1005 
1006   if (NextNonComment->is(tok::l_brace) && NextNonComment->is(BK_Block))
1007     return Current.NestingLevel == 0 ? State.FirstIndent
1008                                      : State.Stack.back().Indent;
1009   if ((Current.isOneOf(tok::r_brace, tok::r_square) ||
1010        (Current.is(tok::greater) &&
1011         (Style.Language == FormatStyle::LK_Proto ||
1012          Style.Language == FormatStyle::LK_TextProto))) &&
1013       State.Stack.size() > 1) {
1014     if (Current.closesBlockOrBlockTypeList(Style))
1015       return State.Stack[State.Stack.size() - 2].NestedBlockIndent;
1016     if (Current.MatchingParen && Current.MatchingParen->is(BK_BracedInit))
1017       return State.Stack[State.Stack.size() - 2].LastSpace;
1018     return State.FirstIndent;
1019   }
1020   // Indent a closing parenthesis at the previous level if followed by a semi,
1021   // const, or opening brace. This allows indentations such as:
1022   //     foo(
1023   //       a,
1024   //     );
1025   //     int Foo::getter(
1026   //         //
1027   //     ) const {
1028   //       return foo;
1029   //     }
1030   //     function foo(
1031   //       a,
1032   //     ) {
1033   //       code(); //
1034   //     }
1035   if (Current.is(tok::r_paren) && State.Stack.size() > 1 &&
1036       (!Current.Next ||
1037        Current.Next->isOneOf(tok::semi, tok::kw_const, tok::l_brace)))
1038     return State.Stack[State.Stack.size() - 2].LastSpace;
1039   if (NextNonComment->is(TT_TemplateString) && NextNonComment->closesScope())
1040     return State.Stack[State.Stack.size() - 2].LastSpace;
1041   if (Current.is(tok::identifier) && Current.Next &&
1042       (Current.Next->is(TT_DictLiteral) ||
1043        ((Style.Language == FormatStyle::LK_Proto ||
1044          Style.Language == FormatStyle::LK_TextProto) &&
1045         Current.Next->isOneOf(tok::less, tok::l_brace))))
1046     return State.Stack.back().Indent;
1047   if (NextNonComment->is(TT_ObjCStringLiteral) &&
1048       State.StartOfStringLiteral != 0)
1049     return State.StartOfStringLiteral - 1;
1050   if (NextNonComment->isStringLiteral() && State.StartOfStringLiteral != 0)
1051     return State.StartOfStringLiteral;
1052   if (NextNonComment->is(tok::lessless) &&
1053       State.Stack.back().FirstLessLess != 0)
1054     return State.Stack.back().FirstLessLess;
1055   if (NextNonComment->isMemberAccess()) {
1056     if (State.Stack.back().CallContinuation == 0)
1057       return ContinuationIndent;
1058     return State.Stack.back().CallContinuation;
1059   }
1060   if (State.Stack.back().QuestionColumn != 0 &&
1061       ((NextNonComment->is(tok::colon) &&
1062         NextNonComment->is(TT_ConditionalExpr)) ||
1063        Previous.is(TT_ConditionalExpr))) {
1064     if (((NextNonComment->is(tok::colon) && NextNonComment->Next &&
1065           !NextNonComment->Next->FakeLParens.empty() &&
1066           NextNonComment->Next->FakeLParens.back() == prec::Conditional) ||
1067          (Previous.is(tok::colon) && !Current.FakeLParens.empty() &&
1068           Current.FakeLParens.back() == prec::Conditional)) &&
1069         !State.Stack.back().IsWrappedConditional) {
1070       // NOTE: we may tweak this slightly:
1071       //    * not remove the 'lead' ContinuationIndentWidth
1072       //    * always un-indent by the operator when
1073       //    BreakBeforeTernaryOperators=true
1074       unsigned Indent = State.Stack.back().Indent;
1075       if (Style.AlignOperands != FormatStyle::OAS_DontAlign) {
1076         Indent -= Style.ContinuationIndentWidth;
1077       }
1078       if (Style.BreakBeforeTernaryOperators &&
1079           State.Stack.back().UnindentOperator)
1080         Indent -= 2;
1081       return Indent;
1082     }
1083     return State.Stack.back().QuestionColumn;
1084   }
1085   if (Previous.is(tok::comma) && State.Stack.back().VariablePos != 0)
1086     return State.Stack.back().VariablePos;
1087   if ((PreviousNonComment &&
1088        (PreviousNonComment->ClosesTemplateDeclaration ||
1089         PreviousNonComment->isOneOf(
1090             TT_AttributeParen, TT_AttributeSquare, TT_FunctionAnnotationRParen,
1091             TT_JavaAnnotation, TT_LeadingJavaAnnotation))) ||
1092       (!Style.IndentWrappedFunctionNames &&
1093        NextNonComment->isOneOf(tok::kw_operator, TT_FunctionDeclarationName)))
1094     return std::max(State.Stack.back().LastSpace, State.Stack.back().Indent);
1095   if (NextNonComment->is(TT_SelectorName)) {
1096     if (!State.Stack.back().ObjCSelectorNameFound) {
1097       unsigned MinIndent = State.Stack.back().Indent;
1098       if (shouldIndentWrappedSelectorName(Style, State.Line->Type))
1099         MinIndent = std::max(MinIndent,
1100                              State.FirstIndent + Style.ContinuationIndentWidth);
1101       // If LongestObjCSelectorName is 0, we are indenting the first
1102       // part of an ObjC selector (or a selector component which is
1103       // not colon-aligned due to block formatting).
1104       //
1105       // Otherwise, we are indenting a subsequent part of an ObjC
1106       // selector which should be colon-aligned to the longest
1107       // component of the ObjC selector.
1108       //
1109       // In either case, we want to respect Style.IndentWrappedFunctionNames.
1110       return MinIndent +
1111              std::max(NextNonComment->LongestObjCSelectorName,
1112                       NextNonComment->ColumnWidth) -
1113              NextNonComment->ColumnWidth;
1114     }
1115     if (!State.Stack.back().AlignColons)
1116       return State.Stack.back().Indent;
1117     if (State.Stack.back().ColonPos > NextNonComment->ColumnWidth)
1118       return State.Stack.back().ColonPos - NextNonComment->ColumnWidth;
1119     return State.Stack.back().Indent;
1120   }
1121   if (NextNonComment->is(tok::colon) && NextNonComment->is(TT_ObjCMethodExpr))
1122     return State.Stack.back().ColonPos;
1123   if (NextNonComment->is(TT_ArraySubscriptLSquare)) {
1124     if (State.Stack.back().StartOfArraySubscripts != 0)
1125       return State.Stack.back().StartOfArraySubscripts;
1126     else if (Style.isCSharp()) // C# allows `["key"] = value` inside object
1127                                // initializers.
1128       return State.Stack.back().Indent;
1129     return ContinuationIndent;
1130   }
1131 
1132   // This ensure that we correctly format ObjC methods calls without inputs,
1133   // i.e. where the last element isn't selector like: [callee method];
1134   if (NextNonComment->is(tok::identifier) && NextNonComment->FakeRParens == 0 &&
1135       NextNonComment->Next && NextNonComment->Next->is(TT_ObjCMethodExpr))
1136     return State.Stack.back().Indent;
1137 
1138   if (NextNonComment->isOneOf(TT_StartOfName, TT_PointerOrReference) ||
1139       Previous.isOneOf(tok::coloncolon, tok::equal, TT_JsTypeColon))
1140     return ContinuationIndent;
1141   if (PreviousNonComment && PreviousNonComment->is(tok::colon) &&
1142       PreviousNonComment->isOneOf(TT_ObjCMethodExpr, TT_DictLiteral))
1143     return ContinuationIndent;
1144   if (NextNonComment->is(TT_CtorInitializerComma))
1145     return State.Stack.back().Indent;
1146   if (PreviousNonComment && PreviousNonComment->is(TT_CtorInitializerColon) &&
1147       Style.BreakConstructorInitializers == FormatStyle::BCIS_AfterColon)
1148     return State.Stack.back().Indent;
1149   if (PreviousNonComment && PreviousNonComment->is(TT_InheritanceColon) &&
1150       Style.BreakInheritanceList == FormatStyle::BILS_AfterColon)
1151     return State.Stack.back().Indent;
1152   if (NextNonComment->isOneOf(TT_CtorInitializerColon, TT_InheritanceColon,
1153                               TT_InheritanceComma))
1154     return State.FirstIndent + Style.ConstructorInitializerIndentWidth;
1155   if (Previous.is(tok::r_paren) && !Current.isBinaryOperator() &&
1156       !Current.isOneOf(tok::colon, tok::comment))
1157     return ContinuationIndent;
1158   if (Current.is(TT_ProtoExtensionLSquare))
1159     return State.Stack.back().Indent;
1160   if (Current.isBinaryOperator() && State.Stack.back().UnindentOperator)
1161     return State.Stack.back().Indent - Current.Tok.getLength() -
1162            Current.SpacesRequiredBefore;
1163   if (Current.isOneOf(tok::comment, TT_BlockComment, TT_LineComment) &&
1164       NextNonComment->isBinaryOperator() && State.Stack.back().UnindentOperator)
1165     return State.Stack.back().Indent - NextNonComment->Tok.getLength() -
1166            NextNonComment->SpacesRequiredBefore;
1167   if (State.Stack.back().Indent == State.FirstIndent && PreviousNonComment &&
1168       !PreviousNonComment->isOneOf(tok::r_brace, TT_CtorInitializerComma))
1169     // Ensure that we fall back to the continuation indent width instead of
1170     // just flushing continuations left.
1171     return State.Stack.back().Indent + Style.ContinuationIndentWidth;
1172   return State.Stack.back().Indent;
1173 }
1174 
1175 static bool hasNestedBlockInlined(const FormatToken *Previous,
1176                                   const FormatToken &Current,
1177                                   const FormatStyle &Style) {
1178   if (Previous->isNot(tok::l_paren))
1179     return true;
1180   if (Previous->ParameterCount > 1)
1181     return true;
1182 
1183   // Also a nested block if contains a lambda inside function with 1 parameter
1184   return (Style.BraceWrapping.BeforeLambdaBody && Current.is(TT_LambdaLSquare));
1185 }
1186 
1187 unsigned ContinuationIndenter::moveStateToNextToken(LineState &State,
1188                                                     bool DryRun, bool Newline) {
1189   assert(State.Stack.size());
1190   const FormatToken &Current = *State.NextToken;
1191 
1192   if (Current.is(TT_CSharpGenericTypeConstraint))
1193     State.Stack.back().IsCSharpGenericTypeConstraint = true;
1194   if (Current.isOneOf(tok::comma, TT_BinaryOperator))
1195     State.Stack.back().NoLineBreakInOperand = false;
1196   if (Current.isOneOf(TT_InheritanceColon, TT_CSharpGenericTypeConstraintColon))
1197     State.Stack.back().AvoidBinPacking = true;
1198   if (Current.is(tok::lessless) && Current.isNot(TT_OverloadedOperator)) {
1199     if (State.Stack.back().FirstLessLess == 0)
1200       State.Stack.back().FirstLessLess = State.Column;
1201     else
1202       State.Stack.back().LastOperatorWrapped = Newline;
1203   }
1204   if (Current.is(TT_BinaryOperator) && Current.isNot(tok::lessless))
1205     State.Stack.back().LastOperatorWrapped = Newline;
1206   if (Current.is(TT_ConditionalExpr) && Current.Previous &&
1207       !Current.Previous->is(TT_ConditionalExpr))
1208     State.Stack.back().LastOperatorWrapped = Newline;
1209   if (Current.is(TT_ArraySubscriptLSquare) &&
1210       State.Stack.back().StartOfArraySubscripts == 0)
1211     State.Stack.back().StartOfArraySubscripts = State.Column;
1212   if (Current.is(TT_ConditionalExpr) && Current.is(tok::question) &&
1213       ((Current.MustBreakBefore) ||
1214        (Current.getNextNonComment() &&
1215         Current.getNextNonComment()->MustBreakBefore)))
1216     State.Stack.back().IsWrappedConditional = true;
1217   if (Style.BreakBeforeTernaryOperators && Current.is(tok::question))
1218     State.Stack.back().QuestionColumn = State.Column;
1219   if (!Style.BreakBeforeTernaryOperators && Current.isNot(tok::colon)) {
1220     const FormatToken *Previous = Current.Previous;
1221     while (Previous && Previous->isTrailingComment())
1222       Previous = Previous->Previous;
1223     if (Previous && Previous->is(tok::question))
1224       State.Stack.back().QuestionColumn = State.Column;
1225   }
1226   if (!Current.opensScope() && !Current.closesScope() &&
1227       !Current.is(TT_PointerOrReference))
1228     State.LowestLevelOnLine =
1229         std::min(State.LowestLevelOnLine, Current.NestingLevel);
1230   if (Current.isMemberAccess())
1231     State.Stack.back().StartOfFunctionCall =
1232         !Current.NextOperator ? 0 : State.Column;
1233   if (Current.is(TT_SelectorName))
1234     State.Stack.back().ObjCSelectorNameFound = true;
1235   if (Current.is(TT_CtorInitializerColon) &&
1236       Style.BreakConstructorInitializers != FormatStyle::BCIS_AfterColon) {
1237     // Indent 2 from the column, so:
1238     // SomeClass::SomeClass()
1239     //     : First(...), ...
1240     //       Next(...)
1241     //       ^ line up here.
1242     State.Stack.back().Indent =
1243         State.Column +
1244         (Style.BreakConstructorInitializers == FormatStyle::BCIS_BeforeComma
1245              ? 0
1246              : 2);
1247     State.Stack.back().NestedBlockIndent = State.Stack.back().Indent;
1248     if (Style.PackConstructorInitializers > FormatStyle::PCIS_BinPack) {
1249       State.Stack.back().AvoidBinPacking = true;
1250       State.Stack.back().BreakBeforeParameter =
1251           Style.PackConstructorInitializers != FormatStyle::PCIS_NextLine;
1252     } else {
1253       State.Stack.back().BreakBeforeParameter = false;
1254     }
1255   }
1256   if (Current.is(TT_CtorInitializerColon) &&
1257       Style.BreakConstructorInitializers == FormatStyle::BCIS_AfterColon) {
1258     State.Stack.back().Indent =
1259         State.FirstIndent + Style.ConstructorInitializerIndentWidth;
1260     State.Stack.back().NestedBlockIndent = State.Stack.back().Indent;
1261     if (Style.PackConstructorInitializers > FormatStyle::PCIS_BinPack)
1262       State.Stack.back().AvoidBinPacking = true;
1263   }
1264   if (Current.is(TT_InheritanceColon))
1265     State.Stack.back().Indent =
1266         State.FirstIndent + Style.ConstructorInitializerIndentWidth;
1267   if (Current.isOneOf(TT_BinaryOperator, TT_ConditionalExpr) && Newline)
1268     State.Stack.back().NestedBlockIndent =
1269         State.Column + Current.ColumnWidth + 1;
1270   if (Current.isOneOf(TT_LambdaLSquare, TT_LambdaArrow))
1271     State.Stack.back().LastSpace = State.Column;
1272 
1273   // Insert scopes created by fake parenthesis.
1274   const FormatToken *Previous = Current.getPreviousNonComment();
1275 
1276   // Add special behavior to support a format commonly used for JavaScript
1277   // closures:
1278   //   SomeFunction(function() {
1279   //     foo();
1280   //     bar();
1281   //   }, a, b, c);
1282   if (Current.isNot(tok::comment) && Previous &&
1283       Previous->isOneOf(tok::l_brace, TT_ArrayInitializerLSquare) &&
1284       !Previous->is(TT_DictLiteral) && State.Stack.size() > 1 &&
1285       !State.Stack.back().HasMultipleNestedBlocks) {
1286     if (State.Stack[State.Stack.size() - 2].NestedBlockInlined && Newline)
1287       for (unsigned i = 0, e = State.Stack.size() - 1; i != e; ++i)
1288         State.Stack[i].NoLineBreak = true;
1289     State.Stack[State.Stack.size() - 2].NestedBlockInlined = false;
1290   }
1291   if (Previous && (Previous->isOneOf(TT_BinaryOperator, TT_ConditionalExpr) ||
1292                    (Previous->isOneOf(tok::l_paren, tok::comma, tok::colon) &&
1293                     !Previous->isOneOf(TT_DictLiteral, TT_ObjCMethodExpr)))) {
1294     State.Stack.back().NestedBlockInlined =
1295         !Newline && hasNestedBlockInlined(Previous, Current, Style);
1296   }
1297 
1298   moveStatePastFakeLParens(State, Newline);
1299   moveStatePastScopeCloser(State);
1300   bool AllowBreak = !State.Stack.back().NoLineBreak &&
1301                     !State.Stack.back().NoLineBreakInOperand;
1302   moveStatePastScopeOpener(State, Newline);
1303   moveStatePastFakeRParens(State);
1304 
1305   if (Current.is(TT_ObjCStringLiteral) && State.StartOfStringLiteral == 0)
1306     State.StartOfStringLiteral = State.Column + 1;
1307   if (Current.is(TT_CSharpStringLiteral) && State.StartOfStringLiteral == 0)
1308     State.StartOfStringLiteral = State.Column + 1;
1309   else if (Current.isStringLiteral() && State.StartOfStringLiteral == 0)
1310     State.StartOfStringLiteral = State.Column;
1311   else if (!Current.isOneOf(tok::comment, tok::identifier, tok::hash) &&
1312            !Current.isStringLiteral())
1313     State.StartOfStringLiteral = 0;
1314 
1315   State.Column += Current.ColumnWidth;
1316   State.NextToken = State.NextToken->Next;
1317 
1318   unsigned Penalty =
1319       handleEndOfLine(Current, State, DryRun, AllowBreak, Newline);
1320 
1321   if (Current.Role)
1322     Current.Role->formatFromToken(State, this, DryRun);
1323   // If the previous has a special role, let it consume tokens as appropriate.
1324   // It is necessary to start at the previous token for the only implemented
1325   // role (comma separated list). That way, the decision whether or not to break
1326   // after the "{" is already done and both options are tried and evaluated.
1327   // FIXME: This is ugly, find a better way.
1328   if (Previous && Previous->Role)
1329     Penalty += Previous->Role->formatAfterToken(State, this, DryRun);
1330 
1331   return Penalty;
1332 }
1333 
1334 void ContinuationIndenter::moveStatePastFakeLParens(LineState &State,
1335                                                     bool Newline) {
1336   const FormatToken &Current = *State.NextToken;
1337   if (Current.FakeLParens.empty())
1338     return;
1339 
1340   const FormatToken *Previous = Current.getPreviousNonComment();
1341 
1342   // Don't add extra indentation for the first fake parenthesis after
1343   // 'return', assignments or opening <({[. The indentation for these cases
1344   // is special cased.
1345   bool SkipFirstExtraIndent =
1346       (Previous && (Previous->opensScope() ||
1347                     Previous->isOneOf(tok::semi, tok::kw_return) ||
1348                     (Previous->getPrecedence() == prec::Assignment &&
1349                      Style.AlignOperands != FormatStyle::OAS_DontAlign) ||
1350                     Previous->is(TT_ObjCMethodExpr)));
1351   for (const auto &PrecedenceLevel : llvm::reverse(Current.FakeLParens)) {
1352     ParenState NewParenState = State.Stack.back();
1353     NewParenState.Tok = nullptr;
1354     NewParenState.ContainsLineBreak = false;
1355     NewParenState.LastOperatorWrapped = true;
1356     NewParenState.IsChainedConditional = false;
1357     NewParenState.IsWrappedConditional = false;
1358     NewParenState.UnindentOperator = false;
1359     NewParenState.NoLineBreak =
1360         NewParenState.NoLineBreak || State.Stack.back().NoLineBreakInOperand;
1361 
1362     // Don't propagate AvoidBinPacking into subexpressions of arg/param lists.
1363     if (PrecedenceLevel > prec::Comma)
1364       NewParenState.AvoidBinPacking = false;
1365 
1366     // Indent from 'LastSpace' unless these are fake parentheses encapsulating
1367     // a builder type call after 'return' or, if the alignment after opening
1368     // brackets is disabled.
1369     if (!Current.isTrailingComment() &&
1370         (Style.AlignOperands != FormatStyle::OAS_DontAlign ||
1371          PrecedenceLevel < prec::Assignment) &&
1372         (!Previous || Previous->isNot(tok::kw_return) ||
1373          (Style.Language != FormatStyle::LK_Java && PrecedenceLevel > 0)) &&
1374         (Style.AlignAfterOpenBracket != FormatStyle::BAS_DontAlign ||
1375          PrecedenceLevel != prec::Comma || Current.NestingLevel == 0)) {
1376       NewParenState.Indent =
1377           std::max(std::max(State.Column, NewParenState.Indent),
1378                    State.Stack.back().LastSpace);
1379     }
1380 
1381     if (Previous &&
1382         (Previous->getPrecedence() == prec::Assignment ||
1383          Previous->is(tok::kw_return) ||
1384          (PrecedenceLevel == prec::Conditional && Previous->is(tok::question) &&
1385           Previous->is(TT_ConditionalExpr))) &&
1386         !Newline) {
1387       // If BreakBeforeBinaryOperators is set, un-indent a bit to account for
1388       // the operator and keep the operands aligned
1389       if (Style.AlignOperands == FormatStyle::OAS_AlignAfterOperator)
1390         NewParenState.UnindentOperator = true;
1391       // Mark indentation as alignment if the expression is aligned.
1392       if (Style.AlignOperands != FormatStyle::OAS_DontAlign)
1393         NewParenState.IsAligned = true;
1394     }
1395 
1396     // Do not indent relative to the fake parentheses inserted for "." or "->".
1397     // This is a special case to make the following to statements consistent:
1398     //   OuterFunction(InnerFunctionCall( // break
1399     //       ParameterToInnerFunction));
1400     //   OuterFunction(SomeObject.InnerFunctionCall( // break
1401     //       ParameterToInnerFunction));
1402     if (PrecedenceLevel > prec::Unknown)
1403       NewParenState.LastSpace = std::max(NewParenState.LastSpace, State.Column);
1404     if (PrecedenceLevel != prec::Conditional && !Current.is(TT_UnaryOperator) &&
1405         Style.AlignAfterOpenBracket != FormatStyle::BAS_DontAlign)
1406       NewParenState.StartOfFunctionCall = State.Column;
1407 
1408     // Indent conditional expressions, unless they are chained "else-if"
1409     // conditionals. Never indent expression where the 'operator' is ',', ';' or
1410     // an assignment (i.e. *I <= prec::Assignment) as those have different
1411     // indentation rules. Indent other expression, unless the indentation needs
1412     // to be skipped.
1413     if (PrecedenceLevel == prec::Conditional && Previous &&
1414         Previous->is(tok::colon) && Previous->is(TT_ConditionalExpr) &&
1415         &PrecedenceLevel == &Current.FakeLParens.back() &&
1416         !State.Stack.back().IsWrappedConditional) {
1417       NewParenState.IsChainedConditional = true;
1418       NewParenState.UnindentOperator = State.Stack.back().UnindentOperator;
1419     } else if (PrecedenceLevel == prec::Conditional ||
1420                (!SkipFirstExtraIndent && PrecedenceLevel > prec::Assignment &&
1421                 !Current.isTrailingComment())) {
1422       NewParenState.Indent += Style.ContinuationIndentWidth;
1423     }
1424     if ((Previous && !Previous->opensScope()) || PrecedenceLevel != prec::Comma)
1425       NewParenState.BreakBeforeParameter = false;
1426     State.Stack.push_back(NewParenState);
1427     SkipFirstExtraIndent = false;
1428   }
1429 }
1430 
1431 void ContinuationIndenter::moveStatePastFakeRParens(LineState &State) {
1432   for (unsigned i = 0, e = State.NextToken->FakeRParens; i != e; ++i) {
1433     unsigned VariablePos = State.Stack.back().VariablePos;
1434     if (State.Stack.size() == 1) {
1435       // Do not pop the last element.
1436       break;
1437     }
1438     State.Stack.pop_back();
1439     State.Stack.back().VariablePos = VariablePos;
1440   }
1441 }
1442 
1443 void ContinuationIndenter::moveStatePastScopeOpener(LineState &State,
1444                                                     bool Newline) {
1445   const FormatToken &Current = *State.NextToken;
1446   if (!Current.opensScope())
1447     return;
1448 
1449   // Don't allow '<' or '(' in C# generic type constraints to start new scopes.
1450   if (Current.isOneOf(tok::less, tok::l_paren) &&
1451       State.Stack.back().IsCSharpGenericTypeConstraint)
1452     return;
1453 
1454   if (Current.MatchingParen && Current.is(BK_Block)) {
1455     moveStateToNewBlock(State);
1456     return;
1457   }
1458 
1459   unsigned NewIndent;
1460   unsigned LastSpace = State.Stack.back().LastSpace;
1461   bool AvoidBinPacking;
1462   bool BreakBeforeParameter = false;
1463   unsigned NestedBlockIndent = std::max(State.Stack.back().StartOfFunctionCall,
1464                                         State.Stack.back().NestedBlockIndent);
1465   if (Current.isOneOf(tok::l_brace, TT_ArrayInitializerLSquare) ||
1466       opensProtoMessageField(Current, Style)) {
1467     if (Current.opensBlockOrBlockTypeList(Style)) {
1468       NewIndent = Style.IndentWidth +
1469                   std::min(State.Column, State.Stack.back().NestedBlockIndent);
1470     } else {
1471       NewIndent = State.Stack.back().LastSpace + Style.ContinuationIndentWidth;
1472     }
1473     const FormatToken *NextNoComment = Current.getNextNonComment();
1474     bool EndsInComma = Current.MatchingParen &&
1475                        Current.MatchingParen->Previous &&
1476                        Current.MatchingParen->Previous->is(tok::comma);
1477     AvoidBinPacking = EndsInComma || Current.is(TT_DictLiteral) ||
1478                       Style.Language == FormatStyle::LK_Proto ||
1479                       Style.Language == FormatStyle::LK_TextProto ||
1480                       !Style.BinPackArguments ||
1481                       (NextNoComment &&
1482                        NextNoComment->isOneOf(TT_DesignatedInitializerPeriod,
1483                                               TT_DesignatedInitializerLSquare));
1484     BreakBeforeParameter = EndsInComma;
1485     if (Current.ParameterCount > 1)
1486       NestedBlockIndent = std::max(NestedBlockIndent, State.Column + 1);
1487   } else {
1488     NewIndent = Style.ContinuationIndentWidth +
1489                 std::max(State.Stack.back().LastSpace,
1490                          State.Stack.back().StartOfFunctionCall);
1491 
1492     // Ensure that different different brackets force relative alignment, e.g.:
1493     // void SomeFunction(vector<  // break
1494     //                       int> v);
1495     // FIXME: We likely want to do this for more combinations of brackets.
1496     if (Current.is(tok::less) && Current.ParentBracket == tok::l_paren) {
1497       NewIndent = std::max(NewIndent, State.Stack.back().Indent);
1498       LastSpace = std::max(LastSpace, State.Stack.back().Indent);
1499     }
1500 
1501     bool EndsInComma =
1502         Current.MatchingParen &&
1503         Current.MatchingParen->getPreviousNonComment() &&
1504         Current.MatchingParen->getPreviousNonComment()->is(tok::comma);
1505 
1506     // If ObjCBinPackProtocolList is unspecified, fall back to BinPackParameters
1507     // for backwards compatibility.
1508     bool ObjCBinPackProtocolList =
1509         (Style.ObjCBinPackProtocolList == FormatStyle::BPS_Auto &&
1510          Style.BinPackParameters) ||
1511         Style.ObjCBinPackProtocolList == FormatStyle::BPS_Always;
1512 
1513     bool BinPackDeclaration =
1514         (State.Line->Type != LT_ObjCDecl && Style.BinPackParameters) ||
1515         (State.Line->Type == LT_ObjCDecl && ObjCBinPackProtocolList);
1516 
1517     AvoidBinPacking =
1518         (State.Stack.back().IsCSharpGenericTypeConstraint) ||
1519         (Style.isJavaScript() && EndsInComma) ||
1520         (State.Line->MustBeDeclaration && !BinPackDeclaration) ||
1521         (!State.Line->MustBeDeclaration && !Style.BinPackArguments) ||
1522         (Style.ExperimentalAutoDetectBinPacking &&
1523          (Current.is(PPK_OnePerLine) ||
1524           (!BinPackInconclusiveFunctions && Current.is(PPK_Inconclusive))));
1525 
1526     if (Current.is(TT_ObjCMethodExpr) && Current.MatchingParen &&
1527         Style.ObjCBreakBeforeNestedBlockParam) {
1528       if (Style.ColumnLimit) {
1529         // If this '[' opens an ObjC call, determine whether all parameters fit
1530         // into one line and put one per line if they don't.
1531         if (getLengthToMatchingParen(Current, State.Stack) + State.Column >
1532             getColumnLimit(State))
1533           BreakBeforeParameter = true;
1534       } else {
1535         // For ColumnLimit = 0, we have to figure out whether there is or has to
1536         // be a line break within this call.
1537         for (const FormatToken *Tok = &Current;
1538              Tok && Tok != Current.MatchingParen; Tok = Tok->Next) {
1539           if (Tok->MustBreakBefore ||
1540               (Tok->CanBreakBefore && Tok->NewlinesBefore > 0)) {
1541             BreakBeforeParameter = true;
1542             break;
1543           }
1544         }
1545       }
1546     }
1547 
1548     if (Style.isJavaScript() && EndsInComma)
1549       BreakBeforeParameter = true;
1550   }
1551   // Generally inherit NoLineBreak from the current scope to nested scope.
1552   // However, don't do this for non-empty nested blocks, dict literals and
1553   // array literals as these follow different indentation rules.
1554   bool NoLineBreak =
1555       Current.Children.empty() &&
1556       !Current.isOneOf(TT_DictLiteral, TT_ArrayInitializerLSquare) &&
1557       (State.Stack.back().NoLineBreak ||
1558        State.Stack.back().NoLineBreakInOperand ||
1559        (Current.is(TT_TemplateOpener) &&
1560         State.Stack.back().ContainsUnwrappedBuilder));
1561   State.Stack.push_back(
1562       ParenState(&Current, NewIndent, LastSpace, AvoidBinPacking, NoLineBreak));
1563   State.Stack.back().NestedBlockIndent = NestedBlockIndent;
1564   State.Stack.back().BreakBeforeParameter = BreakBeforeParameter;
1565   State.Stack.back().HasMultipleNestedBlocks =
1566       (Current.BlockParameterCount > 1);
1567 
1568   if (Style.BraceWrapping.BeforeLambdaBody && Current.Next != nullptr &&
1569       Current.Tok.is(tok::l_paren)) {
1570     // Search for any parameter that is a lambda
1571     FormatToken const *next = Current.Next;
1572     while (next != nullptr) {
1573       if (next->is(TT_LambdaLSquare)) {
1574         State.Stack.back().HasMultipleNestedBlocks = true;
1575         break;
1576       }
1577       next = next->Next;
1578     }
1579   }
1580 
1581   State.Stack.back().IsInsideObjCArrayLiteral =
1582       Current.is(TT_ArrayInitializerLSquare) && Current.Previous &&
1583       Current.Previous->is(tok::at);
1584 }
1585 
1586 void ContinuationIndenter::moveStatePastScopeCloser(LineState &State) {
1587   const FormatToken &Current = *State.NextToken;
1588   if (!Current.closesScope())
1589     return;
1590 
1591   // If we encounter a closing ), ], } or >, we can remove a level from our
1592   // stacks.
1593   if (State.Stack.size() > 1 &&
1594       (Current.isOneOf(tok::r_paren, tok::r_square, TT_TemplateString) ||
1595        (Current.is(tok::r_brace) && State.NextToken != State.Line->First) ||
1596        State.NextToken->is(TT_TemplateCloser) ||
1597        (Current.is(tok::greater) && Current.is(TT_DictLiteral))))
1598     State.Stack.pop_back();
1599 
1600   // Reevaluate whether ObjC message arguments fit into one line.
1601   // If a receiver spans multiple lines, e.g.:
1602   //   [[object block:^{
1603   //     return 42;
1604   //   }] a:42 b:42];
1605   // BreakBeforeParameter is calculated based on an incorrect assumption
1606   // (it is checked whether the whole expression fits into one line without
1607   // considering a line break inside a message receiver).
1608   // We check whether arguments fit after receiver scope closer (into the same
1609   // line).
1610   if (State.Stack.back().BreakBeforeParameter && Current.MatchingParen &&
1611       Current.MatchingParen->Previous) {
1612     const FormatToken &CurrentScopeOpener = *Current.MatchingParen->Previous;
1613     if (CurrentScopeOpener.is(TT_ObjCMethodExpr) &&
1614         CurrentScopeOpener.MatchingParen) {
1615       int NecessarySpaceInLine =
1616           getLengthToMatchingParen(CurrentScopeOpener, State.Stack) +
1617           CurrentScopeOpener.TotalLength - Current.TotalLength - 1;
1618       if (State.Column + Current.ColumnWidth + NecessarySpaceInLine <=
1619           Style.ColumnLimit)
1620         State.Stack.back().BreakBeforeParameter = false;
1621     }
1622   }
1623 
1624   if (Current.is(tok::r_square)) {
1625     // If this ends the array subscript expr, reset the corresponding value.
1626     const FormatToken *NextNonComment = Current.getNextNonComment();
1627     if (NextNonComment && NextNonComment->isNot(tok::l_square))
1628       State.Stack.back().StartOfArraySubscripts = 0;
1629   }
1630 }
1631 
1632 void ContinuationIndenter::moveStateToNewBlock(LineState &State) {
1633   unsigned NestedBlockIndent = State.Stack.back().NestedBlockIndent;
1634   // ObjC block sometimes follow special indentation rules.
1635   unsigned NewIndent =
1636       NestedBlockIndent + (State.NextToken->is(TT_ObjCBlockLBrace)
1637                                ? Style.ObjCBlockIndentWidth
1638                                : Style.IndentWidth);
1639   State.Stack.push_back(ParenState(State.NextToken, NewIndent,
1640                                    State.Stack.back().LastSpace,
1641                                    /*AvoidBinPacking=*/true,
1642                                    /*NoLineBreak=*/false));
1643   State.Stack.back().NestedBlockIndent = NestedBlockIndent;
1644   State.Stack.back().BreakBeforeParameter = true;
1645 }
1646 
1647 static unsigned getLastLineEndColumn(StringRef Text, unsigned StartColumn,
1648                                      unsigned TabWidth,
1649                                      encoding::Encoding Encoding) {
1650   size_t LastNewlinePos = Text.find_last_of("\n");
1651   if (LastNewlinePos == StringRef::npos) {
1652     return StartColumn +
1653            encoding::columnWidthWithTabs(Text, StartColumn, TabWidth, Encoding);
1654   } else {
1655     return encoding::columnWidthWithTabs(Text.substr(LastNewlinePos),
1656                                          /*StartColumn=*/0, TabWidth, Encoding);
1657   }
1658 }
1659 
1660 unsigned ContinuationIndenter::reformatRawStringLiteral(
1661     const FormatToken &Current, LineState &State,
1662     const FormatStyle &RawStringStyle, bool DryRun, bool Newline) {
1663   unsigned StartColumn = State.Column - Current.ColumnWidth;
1664   StringRef OldDelimiter = *getRawStringDelimiter(Current.TokenText);
1665   StringRef NewDelimiter =
1666       getCanonicalRawStringDelimiter(Style, RawStringStyle.Language);
1667   if (NewDelimiter.empty())
1668     NewDelimiter = OldDelimiter;
1669   // The text of a raw string is between the leading 'R"delimiter(' and the
1670   // trailing 'delimiter)"'.
1671   unsigned OldPrefixSize = 3 + OldDelimiter.size();
1672   unsigned OldSuffixSize = 2 + OldDelimiter.size();
1673   // We create a virtual text environment which expects a null-terminated
1674   // string, so we cannot use StringRef.
1675   std::string RawText = std::string(
1676       Current.TokenText.substr(OldPrefixSize).drop_back(OldSuffixSize));
1677   if (NewDelimiter != OldDelimiter) {
1678     // Don't update to the canonical delimiter 'deli' if ')deli"' occurs in the
1679     // raw string.
1680     std::string CanonicalDelimiterSuffix = (")" + NewDelimiter + "\"").str();
1681     if (StringRef(RawText).contains(CanonicalDelimiterSuffix))
1682       NewDelimiter = OldDelimiter;
1683   }
1684 
1685   unsigned NewPrefixSize = 3 + NewDelimiter.size();
1686   unsigned NewSuffixSize = 2 + NewDelimiter.size();
1687 
1688   // The first start column is the column the raw text starts after formatting.
1689   unsigned FirstStartColumn = StartColumn + NewPrefixSize;
1690 
1691   // The next start column is the intended indentation a line break inside
1692   // the raw string at level 0. It is determined by the following rules:
1693   //   - if the content starts on newline, it is one level more than the current
1694   //     indent, and
1695   //   - if the content does not start on a newline, it is the first start
1696   //     column.
1697   // These rules have the advantage that the formatted content both does not
1698   // violate the rectangle rule and visually flows within the surrounding
1699   // source.
1700   bool ContentStartsOnNewline = Current.TokenText[OldPrefixSize] == '\n';
1701   // If this token is the last parameter (checked by looking if it's followed by
1702   // `)` and is not on a newline, the base the indent off the line's nested
1703   // block indent. Otherwise, base the indent off the arguments indent, so we
1704   // can achieve:
1705   //
1706   // fffffffffff(1, 2, 3, R"pb(
1707   //     key1: 1  #
1708   //     key2: 2)pb");
1709   //
1710   // fffffffffff(1, 2, 3,
1711   //             R"pb(
1712   //               key1: 1  #
1713   //               key2: 2
1714   //             )pb");
1715   //
1716   // fffffffffff(1, 2, 3,
1717   //             R"pb(
1718   //               key1: 1  #
1719   //               key2: 2
1720   //             )pb",
1721   //             5);
1722   unsigned CurrentIndent =
1723       (!Newline && Current.Next && Current.Next->is(tok::r_paren))
1724           ? State.Stack.back().NestedBlockIndent
1725           : State.Stack.back().Indent;
1726   unsigned NextStartColumn = ContentStartsOnNewline
1727                                  ? CurrentIndent + Style.IndentWidth
1728                                  : FirstStartColumn;
1729 
1730   // The last start column is the column the raw string suffix starts if it is
1731   // put on a newline.
1732   // The last start column is the intended indentation of the raw string postfix
1733   // if it is put on a newline. It is determined by the following rules:
1734   //   - if the raw string prefix starts on a newline, it is the column where
1735   //     that raw string prefix starts, and
1736   //   - if the raw string prefix does not start on a newline, it is the current
1737   //     indent.
1738   unsigned LastStartColumn =
1739       Current.NewlinesBefore ? FirstStartColumn - NewPrefixSize : CurrentIndent;
1740 
1741   std::pair<tooling::Replacements, unsigned> Fixes = internal::reformat(
1742       RawStringStyle, RawText, {tooling::Range(0, RawText.size())},
1743       FirstStartColumn, NextStartColumn, LastStartColumn, "<stdin>",
1744       /*Status=*/nullptr);
1745 
1746   auto NewCode = applyAllReplacements(RawText, Fixes.first);
1747   tooling::Replacements NoFixes;
1748   if (!NewCode) {
1749     return addMultilineToken(Current, State);
1750   }
1751   if (!DryRun) {
1752     if (NewDelimiter != OldDelimiter) {
1753       // In 'R"delimiter(...', the delimiter starts 2 characters after the start
1754       // of the token.
1755       SourceLocation PrefixDelimiterStart =
1756           Current.Tok.getLocation().getLocWithOffset(2);
1757       auto PrefixErr = Whitespaces.addReplacement(tooling::Replacement(
1758           SourceMgr, PrefixDelimiterStart, OldDelimiter.size(), NewDelimiter));
1759       if (PrefixErr) {
1760         llvm::errs()
1761             << "Failed to update the prefix delimiter of a raw string: "
1762             << llvm::toString(std::move(PrefixErr)) << "\n";
1763       }
1764       // In 'R"delimiter(...)delimiter"', the suffix delimiter starts at
1765       // position length - 1 - |delimiter|.
1766       SourceLocation SuffixDelimiterStart =
1767           Current.Tok.getLocation().getLocWithOffset(Current.TokenText.size() -
1768                                                      1 - OldDelimiter.size());
1769       auto SuffixErr = Whitespaces.addReplacement(tooling::Replacement(
1770           SourceMgr, SuffixDelimiterStart, OldDelimiter.size(), NewDelimiter));
1771       if (SuffixErr) {
1772         llvm::errs()
1773             << "Failed to update the suffix delimiter of a raw string: "
1774             << llvm::toString(std::move(SuffixErr)) << "\n";
1775       }
1776     }
1777     SourceLocation OriginLoc =
1778         Current.Tok.getLocation().getLocWithOffset(OldPrefixSize);
1779     for (const tooling::Replacement &Fix : Fixes.first) {
1780       auto Err = Whitespaces.addReplacement(tooling::Replacement(
1781           SourceMgr, OriginLoc.getLocWithOffset(Fix.getOffset()),
1782           Fix.getLength(), Fix.getReplacementText()));
1783       if (Err) {
1784         llvm::errs() << "Failed to reformat raw string: "
1785                      << llvm::toString(std::move(Err)) << "\n";
1786       }
1787     }
1788   }
1789   unsigned RawLastLineEndColumn = getLastLineEndColumn(
1790       *NewCode, FirstStartColumn, Style.TabWidth, Encoding);
1791   State.Column = RawLastLineEndColumn + NewSuffixSize;
1792   // Since we're updating the column to after the raw string literal here, we
1793   // have to manually add the penalty for the prefix R"delim( over the column
1794   // limit.
1795   unsigned PrefixExcessCharacters =
1796       StartColumn + NewPrefixSize > Style.ColumnLimit
1797           ? StartColumn + NewPrefixSize - Style.ColumnLimit
1798           : 0;
1799   bool IsMultiline =
1800       ContentStartsOnNewline || (NewCode->find('\n') != std::string::npos);
1801   if (IsMultiline) {
1802     // Break before further function parameters on all levels.
1803     for (unsigned i = 0, e = State.Stack.size(); i != e; ++i)
1804       State.Stack[i].BreakBeforeParameter = true;
1805   }
1806   return Fixes.second + PrefixExcessCharacters * Style.PenaltyExcessCharacter;
1807 }
1808 
1809 unsigned ContinuationIndenter::addMultilineToken(const FormatToken &Current,
1810                                                  LineState &State) {
1811   // Break before further function parameters on all levels.
1812   for (unsigned i = 0, e = State.Stack.size(); i != e; ++i)
1813     State.Stack[i].BreakBeforeParameter = true;
1814 
1815   unsigned ColumnsUsed = State.Column;
1816   // We can only affect layout of the first and the last line, so the penalty
1817   // for all other lines is constant, and we ignore it.
1818   State.Column = Current.LastLineColumnWidth;
1819 
1820   if (ColumnsUsed > getColumnLimit(State))
1821     return Style.PenaltyExcessCharacter * (ColumnsUsed - getColumnLimit(State));
1822   return 0;
1823 }
1824 
1825 unsigned ContinuationIndenter::handleEndOfLine(const FormatToken &Current,
1826                                                LineState &State, bool DryRun,
1827                                                bool AllowBreak, bool Newline) {
1828   unsigned Penalty = 0;
1829   // Compute the raw string style to use in case this is a raw string literal
1830   // that can be reformatted.
1831   auto RawStringStyle = getRawStringStyle(Current, State);
1832   if (RawStringStyle && !Current.Finalized) {
1833     Penalty = reformatRawStringLiteral(Current, State, *RawStringStyle, DryRun,
1834                                        Newline);
1835   } else if (Current.IsMultiline && Current.isNot(TT_BlockComment)) {
1836     // Don't break multi-line tokens other than block comments and raw string
1837     // literals. Instead, just update the state.
1838     Penalty = addMultilineToken(Current, State);
1839   } else if (State.Line->Type != LT_ImportStatement) {
1840     // We generally don't break import statements.
1841     LineState OriginalState = State;
1842 
1843     // Whether we force the reflowing algorithm to stay strictly within the
1844     // column limit.
1845     bool Strict = false;
1846     // Whether the first non-strict attempt at reflowing did intentionally
1847     // exceed the column limit.
1848     bool Exceeded = false;
1849     std::tie(Penalty, Exceeded) = breakProtrudingToken(
1850         Current, State, AllowBreak, /*DryRun=*/true, Strict);
1851     if (Exceeded) {
1852       // If non-strict reflowing exceeds the column limit, try whether strict
1853       // reflowing leads to an overall lower penalty.
1854       LineState StrictState = OriginalState;
1855       unsigned StrictPenalty =
1856           breakProtrudingToken(Current, StrictState, AllowBreak,
1857                                /*DryRun=*/true, /*Strict=*/true)
1858               .first;
1859       Strict = StrictPenalty <= Penalty;
1860       if (Strict) {
1861         Penalty = StrictPenalty;
1862         State = StrictState;
1863       }
1864     }
1865     if (!DryRun) {
1866       // If we're not in dry-run mode, apply the changes with the decision on
1867       // strictness made above.
1868       breakProtrudingToken(Current, OriginalState, AllowBreak, /*DryRun=*/false,
1869                            Strict);
1870     }
1871   }
1872   if (State.Column > getColumnLimit(State)) {
1873     unsigned ExcessCharacters = State.Column - getColumnLimit(State);
1874     Penalty += Style.PenaltyExcessCharacter * ExcessCharacters;
1875   }
1876   return Penalty;
1877 }
1878 
1879 // Returns the enclosing function name of a token, or the empty string if not
1880 // found.
1881 static StringRef getEnclosingFunctionName(const FormatToken &Current) {
1882   // Look for: 'function(' or 'function<templates>(' before Current.
1883   auto Tok = Current.getPreviousNonComment();
1884   if (!Tok || !Tok->is(tok::l_paren))
1885     return "";
1886   Tok = Tok->getPreviousNonComment();
1887   if (!Tok)
1888     return "";
1889   if (Tok->is(TT_TemplateCloser)) {
1890     Tok = Tok->MatchingParen;
1891     if (Tok)
1892       Tok = Tok->getPreviousNonComment();
1893   }
1894   if (!Tok || !Tok->is(tok::identifier))
1895     return "";
1896   return Tok->TokenText;
1897 }
1898 
1899 llvm::Optional<FormatStyle>
1900 ContinuationIndenter::getRawStringStyle(const FormatToken &Current,
1901                                         const LineState &State) {
1902   if (!Current.isStringLiteral())
1903     return None;
1904   auto Delimiter = getRawStringDelimiter(Current.TokenText);
1905   if (!Delimiter)
1906     return None;
1907   auto RawStringStyle = RawStringFormats.getDelimiterStyle(*Delimiter);
1908   if (!RawStringStyle && Delimiter->empty())
1909     RawStringStyle = RawStringFormats.getEnclosingFunctionStyle(
1910         getEnclosingFunctionName(Current));
1911   if (!RawStringStyle)
1912     return None;
1913   RawStringStyle->ColumnLimit = getColumnLimit(State);
1914   return RawStringStyle;
1915 }
1916 
1917 std::unique_ptr<BreakableToken>
1918 ContinuationIndenter::createBreakableToken(const FormatToken &Current,
1919                                            LineState &State, bool AllowBreak) {
1920   unsigned StartColumn = State.Column - Current.ColumnWidth;
1921   if (Current.isStringLiteral()) {
1922     // FIXME: String literal breaking is currently disabled for C#, Java, Json
1923     // and JavaScript, as it requires strings to be merged using "+" which we
1924     // don't support.
1925     if (Style.Language == FormatStyle::LK_Java || Style.isJavaScript() ||
1926         Style.isCSharp() || Style.isJson() || !Style.BreakStringLiterals ||
1927         !AllowBreak)
1928       return nullptr;
1929 
1930     // Don't break string literals inside preprocessor directives (except for
1931     // #define directives, as their contents are stored in separate lines and
1932     // are not affected by this check).
1933     // This way we avoid breaking code with line directives and unknown
1934     // preprocessor directives that contain long string literals.
1935     if (State.Line->Type == LT_PreprocessorDirective)
1936       return nullptr;
1937     // Exempts unterminated string literals from line breaking. The user will
1938     // likely want to terminate the string before any line breaking is done.
1939     if (Current.IsUnterminatedLiteral)
1940       return nullptr;
1941     // Don't break string literals inside Objective-C array literals (doing so
1942     // raises the warning -Wobjc-string-concatenation).
1943     if (State.Stack.back().IsInsideObjCArrayLiteral) {
1944       return nullptr;
1945     }
1946 
1947     StringRef Text = Current.TokenText;
1948     StringRef Prefix;
1949     StringRef Postfix;
1950     // FIXME: Handle whitespace between '_T', '(', '"..."', and ')'.
1951     // FIXME: Store Prefix and Suffix (or PrefixLength and SuffixLength to
1952     // reduce the overhead) for each FormatToken, which is a string, so that we
1953     // don't run multiple checks here on the hot path.
1954     if ((Text.endswith(Postfix = "\"") &&
1955          (Text.startswith(Prefix = "@\"") || Text.startswith(Prefix = "\"") ||
1956           Text.startswith(Prefix = "u\"") || Text.startswith(Prefix = "U\"") ||
1957           Text.startswith(Prefix = "u8\"") ||
1958           Text.startswith(Prefix = "L\""))) ||
1959         (Text.startswith(Prefix = "_T(\"") && Text.endswith(Postfix = "\")"))) {
1960       // We need this to address the case where there is an unbreakable tail
1961       // only if certain other formatting decisions have been taken. The
1962       // UnbreakableTailLength of Current is an overapproximation is that case
1963       // and we need to be correct here.
1964       unsigned UnbreakableTailLength = (State.NextToken && canBreak(State))
1965                                            ? 0
1966                                            : Current.UnbreakableTailLength;
1967       return std::make_unique<BreakableStringLiteral>(
1968           Current, StartColumn, Prefix, Postfix, UnbreakableTailLength,
1969           State.Line->InPPDirective, Encoding, Style);
1970     }
1971   } else if (Current.is(TT_BlockComment)) {
1972     if (!Style.ReflowComments ||
1973         // If a comment token switches formatting, like
1974         // /* clang-format on */, we don't want to break it further,
1975         // but we may still want to adjust its indentation.
1976         switchesFormatting(Current)) {
1977       return nullptr;
1978     }
1979     return std::make_unique<BreakableBlockComment>(
1980         Current, StartColumn, Current.OriginalColumn, !Current.Previous,
1981         State.Line->InPPDirective, Encoding, Style, Whitespaces.useCRLF());
1982   } else if (Current.is(TT_LineComment) &&
1983              (Current.Previous == nullptr ||
1984               Current.Previous->isNot(TT_ImplicitStringLiteral))) {
1985     bool RegularComments = [&]() {
1986       for (const FormatToken *T = &Current; T && T->is(TT_LineComment);
1987            T = T->Next) {
1988         if (!(T->TokenText.startswith("//") || T->TokenText.startswith("#")))
1989           return false;
1990       }
1991       return true;
1992     }();
1993     if (!Style.ReflowComments ||
1994         CommentPragmasRegex.match(Current.TokenText.substr(2)) ||
1995         switchesFormatting(Current) || !RegularComments)
1996       return nullptr;
1997     return std::make_unique<BreakableLineCommentSection>(
1998         Current, StartColumn, /*InPPDirective=*/false, Encoding, Style);
1999   }
2000   return nullptr;
2001 }
2002 
2003 std::pair<unsigned, bool>
2004 ContinuationIndenter::breakProtrudingToken(const FormatToken &Current,
2005                                            LineState &State, bool AllowBreak,
2006                                            bool DryRun, bool Strict) {
2007   std::unique_ptr<const BreakableToken> Token =
2008       createBreakableToken(Current, State, AllowBreak);
2009   if (!Token)
2010     return {0, false};
2011   assert(Token->getLineCount() > 0);
2012   unsigned ColumnLimit = getColumnLimit(State);
2013   if (Current.is(TT_LineComment)) {
2014     // We don't insert backslashes when breaking line comments.
2015     ColumnLimit = Style.ColumnLimit;
2016   }
2017   if (ColumnLimit == 0) {
2018     // To make the rest of the function easier set the column limit to the
2019     // maximum, if there should be no limit.
2020     ColumnLimit = std::numeric_limits<decltype(ColumnLimit)>::max();
2021   }
2022   if (Current.UnbreakableTailLength >= ColumnLimit)
2023     return {0, false};
2024   // ColumnWidth was already accounted into State.Column before calling
2025   // breakProtrudingToken.
2026   unsigned StartColumn = State.Column - Current.ColumnWidth;
2027   unsigned NewBreakPenalty = Current.isStringLiteral()
2028                                  ? Style.PenaltyBreakString
2029                                  : Style.PenaltyBreakComment;
2030   // Stores whether we intentionally decide to let a line exceed the column
2031   // limit.
2032   bool Exceeded = false;
2033   // Stores whether we introduce a break anywhere in the token.
2034   bool BreakInserted = Token->introducesBreakBeforeToken();
2035   // Store whether we inserted a new line break at the end of the previous
2036   // logical line.
2037   bool NewBreakBefore = false;
2038   // We use a conservative reflowing strategy. Reflow starts after a line is
2039   // broken or the corresponding whitespace compressed. Reflow ends as soon as a
2040   // line that doesn't get reflown with the previous line is reached.
2041   bool Reflow = false;
2042   // Keep track of where we are in the token:
2043   // Where we are in the content of the current logical line.
2044   unsigned TailOffset = 0;
2045   // The column number we're currently at.
2046   unsigned ContentStartColumn =
2047       Token->getContentStartColumn(0, /*Break=*/false);
2048   // The number of columns left in the current logical line after TailOffset.
2049   unsigned RemainingTokenColumns =
2050       Token->getRemainingLength(0, TailOffset, ContentStartColumn);
2051   // Adapt the start of the token, for example indent.
2052   if (!DryRun)
2053     Token->adaptStartOfLine(0, Whitespaces);
2054 
2055   unsigned ContentIndent = 0;
2056   unsigned Penalty = 0;
2057   LLVM_DEBUG(llvm::dbgs() << "Breaking protruding token at column "
2058                           << StartColumn << ".\n");
2059   for (unsigned LineIndex = 0, EndIndex = Token->getLineCount();
2060        LineIndex != EndIndex; ++LineIndex) {
2061     LLVM_DEBUG(llvm::dbgs()
2062                << "  Line: " << LineIndex << " (Reflow: " << Reflow << ")\n");
2063     NewBreakBefore = false;
2064     // If we did reflow the previous line, we'll try reflowing again. Otherwise
2065     // we'll start reflowing if the current line is broken or whitespace is
2066     // compressed.
2067     bool TryReflow = Reflow;
2068     // Break the current token until we can fit the rest of the line.
2069     while (ContentStartColumn + RemainingTokenColumns > ColumnLimit) {
2070       LLVM_DEBUG(llvm::dbgs() << "    Over limit, need: "
2071                               << (ContentStartColumn + RemainingTokenColumns)
2072                               << ", space: " << ColumnLimit
2073                               << ", reflown prefix: " << ContentStartColumn
2074                               << ", offset in line: " << TailOffset << "\n");
2075       // If the current token doesn't fit, find the latest possible split in the
2076       // current line so that breaking at it will be under the column limit.
2077       // FIXME: Use the earliest possible split while reflowing to correctly
2078       // compress whitespace within a line.
2079       BreakableToken::Split Split =
2080           Token->getSplit(LineIndex, TailOffset, ColumnLimit,
2081                           ContentStartColumn, CommentPragmasRegex);
2082       if (Split.first == StringRef::npos) {
2083         // No break opportunity - update the penalty and continue with the next
2084         // logical line.
2085         if (LineIndex < EndIndex - 1)
2086           // The last line's penalty is handled in addNextStateToQueue() or when
2087           // calling replaceWhitespaceAfterLastLine below.
2088           Penalty += Style.PenaltyExcessCharacter *
2089                      (ContentStartColumn + RemainingTokenColumns - ColumnLimit);
2090         LLVM_DEBUG(llvm::dbgs() << "    No break opportunity.\n");
2091         break;
2092       }
2093       assert(Split.first != 0);
2094 
2095       if (Token->supportsReflow()) {
2096         // Check whether the next natural split point after the current one can
2097         // still fit the line, either because we can compress away whitespace,
2098         // or because the penalty the excess characters introduce is lower than
2099         // the break penalty.
2100         // We only do this for tokens that support reflowing, and thus allow us
2101         // to change the whitespace arbitrarily (e.g. comments).
2102         // Other tokens, like string literals, can be broken on arbitrary
2103         // positions.
2104 
2105         // First, compute the columns from TailOffset to the next possible split
2106         // position.
2107         // For example:
2108         // ColumnLimit:     |
2109         // // Some text   that    breaks
2110         //    ^ tail offset
2111         //             ^-- split
2112         //    ^-------- to split columns
2113         //                    ^--- next split
2114         //    ^--------------- to next split columns
2115         unsigned ToSplitColumns = Token->getRangeLength(
2116             LineIndex, TailOffset, Split.first, ContentStartColumn);
2117         LLVM_DEBUG(llvm::dbgs() << "    ToSplit: " << ToSplitColumns << "\n");
2118 
2119         BreakableToken::Split NextSplit = Token->getSplit(
2120             LineIndex, TailOffset + Split.first + Split.second, ColumnLimit,
2121             ContentStartColumn + ToSplitColumns + 1, CommentPragmasRegex);
2122         // Compute the columns necessary to fit the next non-breakable sequence
2123         // into the current line.
2124         unsigned ToNextSplitColumns = 0;
2125         if (NextSplit.first == StringRef::npos) {
2126           ToNextSplitColumns = Token->getRemainingLength(LineIndex, TailOffset,
2127                                                          ContentStartColumn);
2128         } else {
2129           ToNextSplitColumns = Token->getRangeLength(
2130               LineIndex, TailOffset,
2131               Split.first + Split.second + NextSplit.first, ContentStartColumn);
2132         }
2133         // Compress the whitespace between the break and the start of the next
2134         // unbreakable sequence.
2135         ToNextSplitColumns =
2136             Token->getLengthAfterCompression(ToNextSplitColumns, Split);
2137         LLVM_DEBUG(llvm::dbgs()
2138                    << "    ContentStartColumn: " << ContentStartColumn << "\n");
2139         LLVM_DEBUG(llvm::dbgs()
2140                    << "    ToNextSplit: " << ToNextSplitColumns << "\n");
2141         // If the whitespace compression makes us fit, continue on the current
2142         // line.
2143         bool ContinueOnLine =
2144             ContentStartColumn + ToNextSplitColumns <= ColumnLimit;
2145         unsigned ExcessCharactersPenalty = 0;
2146         if (!ContinueOnLine && !Strict) {
2147           // Similarly, if the excess characters' penalty is lower than the
2148           // penalty of introducing a new break, continue on the current line.
2149           ExcessCharactersPenalty =
2150               (ContentStartColumn + ToNextSplitColumns - ColumnLimit) *
2151               Style.PenaltyExcessCharacter;
2152           LLVM_DEBUG(llvm::dbgs()
2153                      << "    Penalty excess: " << ExcessCharactersPenalty
2154                      << "\n            break : " << NewBreakPenalty << "\n");
2155           if (ExcessCharactersPenalty < NewBreakPenalty) {
2156             Exceeded = true;
2157             ContinueOnLine = true;
2158           }
2159         }
2160         if (ContinueOnLine) {
2161           LLVM_DEBUG(llvm::dbgs() << "    Continuing on line...\n");
2162           // The current line fits after compressing the whitespace - reflow
2163           // the next line into it if possible.
2164           TryReflow = true;
2165           if (!DryRun)
2166             Token->compressWhitespace(LineIndex, TailOffset, Split,
2167                                       Whitespaces);
2168           // When we continue on the same line, leave one space between content.
2169           ContentStartColumn += ToSplitColumns + 1;
2170           Penalty += ExcessCharactersPenalty;
2171           TailOffset += Split.first + Split.second;
2172           RemainingTokenColumns = Token->getRemainingLength(
2173               LineIndex, TailOffset, ContentStartColumn);
2174           continue;
2175         }
2176       }
2177       LLVM_DEBUG(llvm::dbgs() << "    Breaking...\n");
2178       // Update the ContentIndent only if the current line was not reflown with
2179       // the previous line, since in that case the previous line should still
2180       // determine the ContentIndent. Also never intent the last line.
2181       if (!Reflow)
2182         ContentIndent = Token->getContentIndent(LineIndex);
2183       LLVM_DEBUG(llvm::dbgs()
2184                  << "    ContentIndent: " << ContentIndent << "\n");
2185       ContentStartColumn = ContentIndent + Token->getContentStartColumn(
2186                                                LineIndex, /*Break=*/true);
2187 
2188       unsigned NewRemainingTokenColumns = Token->getRemainingLength(
2189           LineIndex, TailOffset + Split.first + Split.second,
2190           ContentStartColumn);
2191       if (NewRemainingTokenColumns == 0) {
2192         // No content to indent.
2193         ContentIndent = 0;
2194         ContentStartColumn =
2195             Token->getContentStartColumn(LineIndex, /*Break=*/true);
2196         NewRemainingTokenColumns = Token->getRemainingLength(
2197             LineIndex, TailOffset + Split.first + Split.second,
2198             ContentStartColumn);
2199       }
2200 
2201       // When breaking before a tab character, it may be moved by a few columns,
2202       // but will still be expanded to the next tab stop, so we don't save any
2203       // columns.
2204       if (NewRemainingTokenColumns >= RemainingTokenColumns) {
2205         // FIXME: Do we need to adjust the penalty?
2206         break;
2207       }
2208 
2209       LLVM_DEBUG(llvm::dbgs() << "    Breaking at: " << TailOffset + Split.first
2210                               << ", " << Split.second << "\n");
2211       if (!DryRun)
2212         Token->insertBreak(LineIndex, TailOffset, Split, ContentIndent,
2213                            Whitespaces);
2214 
2215       Penalty += NewBreakPenalty;
2216       TailOffset += Split.first + Split.second;
2217       RemainingTokenColumns = NewRemainingTokenColumns;
2218       BreakInserted = true;
2219       NewBreakBefore = true;
2220     }
2221     // In case there's another line, prepare the state for the start of the next
2222     // line.
2223     if (LineIndex + 1 != EndIndex) {
2224       unsigned NextLineIndex = LineIndex + 1;
2225       if (NewBreakBefore)
2226         // After breaking a line, try to reflow the next line into the current
2227         // one once RemainingTokenColumns fits.
2228         TryReflow = true;
2229       if (TryReflow) {
2230         // We decided that we want to try reflowing the next line into the
2231         // current one.
2232         // We will now adjust the state as if the reflow is successful (in
2233         // preparation for the next line), and see whether that works. If we
2234         // decide that we cannot reflow, we will later reset the state to the
2235         // start of the next line.
2236         Reflow = false;
2237         // As we did not continue breaking the line, RemainingTokenColumns is
2238         // known to fit after ContentStartColumn. Adapt ContentStartColumn to
2239         // the position at which we want to format the next line if we do
2240         // actually reflow.
2241         // When we reflow, we need to add a space between the end of the current
2242         // line and the next line's start column.
2243         ContentStartColumn += RemainingTokenColumns + 1;
2244         // Get the split that we need to reflow next logical line into the end
2245         // of the current one; the split will include any leading whitespace of
2246         // the next logical line.
2247         BreakableToken::Split SplitBeforeNext =
2248             Token->getReflowSplit(NextLineIndex, CommentPragmasRegex);
2249         LLVM_DEBUG(llvm::dbgs()
2250                    << "    Size of reflown text: " << ContentStartColumn
2251                    << "\n    Potential reflow split: ");
2252         if (SplitBeforeNext.first != StringRef::npos) {
2253           LLVM_DEBUG(llvm::dbgs() << SplitBeforeNext.first << ", "
2254                                   << SplitBeforeNext.second << "\n");
2255           TailOffset = SplitBeforeNext.first + SplitBeforeNext.second;
2256           // If the rest of the next line fits into the current line below the
2257           // column limit, we can safely reflow.
2258           RemainingTokenColumns = Token->getRemainingLength(
2259               NextLineIndex, TailOffset, ContentStartColumn);
2260           Reflow = true;
2261           if (ContentStartColumn + RemainingTokenColumns > ColumnLimit) {
2262             LLVM_DEBUG(llvm::dbgs()
2263                        << "    Over limit after reflow, need: "
2264                        << (ContentStartColumn + RemainingTokenColumns)
2265                        << ", space: " << ColumnLimit
2266                        << ", reflown prefix: " << ContentStartColumn
2267                        << ", offset in line: " << TailOffset << "\n");
2268             // If the whole next line does not fit, try to find a point in
2269             // the next line at which we can break so that attaching the part
2270             // of the next line to that break point onto the current line is
2271             // below the column limit.
2272             BreakableToken::Split Split =
2273                 Token->getSplit(NextLineIndex, TailOffset, ColumnLimit,
2274                                 ContentStartColumn, CommentPragmasRegex);
2275             if (Split.first == StringRef::npos) {
2276               LLVM_DEBUG(llvm::dbgs() << "    Did not find later break\n");
2277               Reflow = false;
2278             } else {
2279               // Check whether the first split point gets us below the column
2280               // limit. Note that we will execute this split below as part of
2281               // the normal token breaking and reflow logic within the line.
2282               unsigned ToSplitColumns = Token->getRangeLength(
2283                   NextLineIndex, TailOffset, Split.first, ContentStartColumn);
2284               if (ContentStartColumn + ToSplitColumns > ColumnLimit) {
2285                 LLVM_DEBUG(llvm::dbgs() << "    Next split protrudes, need: "
2286                                         << (ContentStartColumn + ToSplitColumns)
2287                                         << ", space: " << ColumnLimit);
2288                 unsigned ExcessCharactersPenalty =
2289                     (ContentStartColumn + ToSplitColumns - ColumnLimit) *
2290                     Style.PenaltyExcessCharacter;
2291                 if (NewBreakPenalty < ExcessCharactersPenalty) {
2292                   Reflow = false;
2293                 }
2294               }
2295             }
2296           }
2297         } else {
2298           LLVM_DEBUG(llvm::dbgs() << "not found.\n");
2299         }
2300       }
2301       if (!Reflow) {
2302         // If we didn't reflow into the next line, the only space to consider is
2303         // the next logical line. Reset our state to match the start of the next
2304         // line.
2305         TailOffset = 0;
2306         ContentStartColumn =
2307             Token->getContentStartColumn(NextLineIndex, /*Break=*/false);
2308         RemainingTokenColumns = Token->getRemainingLength(
2309             NextLineIndex, TailOffset, ContentStartColumn);
2310         // Adapt the start of the token, for example indent.
2311         if (!DryRun)
2312           Token->adaptStartOfLine(NextLineIndex, Whitespaces);
2313       } else {
2314         // If we found a reflow split and have added a new break before the next
2315         // line, we are going to remove the line break at the start of the next
2316         // logical line. For example, here we'll add a new line break after
2317         // 'text', and subsequently delete the line break between 'that' and
2318         // 'reflows'.
2319         //   // some text that
2320         //   // reflows
2321         // ->
2322         //   // some text
2323         //   // that reflows
2324         // When adding the line break, we also added the penalty for it, so we
2325         // need to subtract that penalty again when we remove the line break due
2326         // to reflowing.
2327         if (NewBreakBefore) {
2328           assert(Penalty >= NewBreakPenalty);
2329           Penalty -= NewBreakPenalty;
2330         }
2331         if (!DryRun)
2332           Token->reflow(NextLineIndex, Whitespaces);
2333       }
2334     }
2335   }
2336 
2337   BreakableToken::Split SplitAfterLastLine =
2338       Token->getSplitAfterLastLine(TailOffset);
2339   if (SplitAfterLastLine.first != StringRef::npos) {
2340     LLVM_DEBUG(llvm::dbgs() << "Replacing whitespace after last line.\n");
2341 
2342     // We add the last line's penalty here, since that line is going to be split
2343     // now.
2344     Penalty += Style.PenaltyExcessCharacter *
2345                (ContentStartColumn + RemainingTokenColumns - ColumnLimit);
2346 
2347     if (!DryRun)
2348       Token->replaceWhitespaceAfterLastLine(TailOffset, SplitAfterLastLine,
2349                                             Whitespaces);
2350     ContentStartColumn =
2351         Token->getContentStartColumn(Token->getLineCount() - 1, /*Break=*/true);
2352     RemainingTokenColumns = Token->getRemainingLength(
2353         Token->getLineCount() - 1,
2354         TailOffset + SplitAfterLastLine.first + SplitAfterLastLine.second,
2355         ContentStartColumn);
2356   }
2357 
2358   State.Column = ContentStartColumn + RemainingTokenColumns -
2359                  Current.UnbreakableTailLength;
2360 
2361   if (BreakInserted) {
2362     // If we break the token inside a parameter list, we need to break before
2363     // the next parameter on all levels, so that the next parameter is clearly
2364     // visible. Line comments already introduce a break.
2365     if (Current.isNot(TT_LineComment)) {
2366       for (unsigned i = 0, e = State.Stack.size(); i != e; ++i)
2367         State.Stack[i].BreakBeforeParameter = true;
2368     }
2369 
2370     if (Current.is(TT_BlockComment))
2371       State.NoContinuation = true;
2372 
2373     State.Stack.back().LastSpace = StartColumn;
2374   }
2375 
2376   Token->updateNextToken(State);
2377 
2378   return {Penalty, Exceeded};
2379 }
2380 
2381 unsigned ContinuationIndenter::getColumnLimit(const LineState &State) const {
2382   // In preprocessor directives reserve two chars for trailing " \"
2383   return Style.ColumnLimit - (State.Line->InPPDirective ? 2 : 0);
2384 }
2385 
2386 bool ContinuationIndenter::nextIsMultilineString(const LineState &State) {
2387   const FormatToken &Current = *State.NextToken;
2388   if (!Current.isStringLiteral() || Current.is(TT_ImplicitStringLiteral))
2389     return false;
2390   // We never consider raw string literals "multiline" for the purpose of
2391   // AlwaysBreakBeforeMultilineStrings implementation as they are special-cased
2392   // (see TokenAnnotator::mustBreakBefore().
2393   if (Current.TokenText.startswith("R\""))
2394     return false;
2395   if (Current.IsMultiline)
2396     return true;
2397   if (Current.getNextNonComment() &&
2398       Current.getNextNonComment()->isStringLiteral())
2399     return true; // Implicit concatenation.
2400   if (Style.ColumnLimit != 0 && Style.BreakStringLiterals &&
2401       State.Column + Current.ColumnWidth + Current.UnbreakableTailLength >
2402           Style.ColumnLimit)
2403     return true; // String will be split.
2404   return false;
2405 }
2406 
2407 } // namespace format
2408 } // namespace clang
2409