xref: /freebsd/contrib/llvm-project/clang/lib/Format/ContinuationIndenter.cpp (revision a521f2116473fbd8c09db395518f060a27d02334)
1 //===--- ContinuationIndenter.cpp - Format C++ code -----------------------===//
2 //
3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4 // See https://llvm.org/LICENSE.txt for license information.
5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6 //
7 //===----------------------------------------------------------------------===//
8 ///
9 /// \file
10 /// This file implements the continuation indenter.
11 ///
12 //===----------------------------------------------------------------------===//
13 
14 #include "ContinuationIndenter.h"
15 #include "BreakableToken.h"
16 #include "FormatInternal.h"
17 #include "WhitespaceManager.h"
18 #include "clang/Basic/OperatorPrecedence.h"
19 #include "clang/Basic/SourceManager.h"
20 #include "clang/Format/Format.h"
21 #include "llvm/Support/Debug.h"
22 
23 #define DEBUG_TYPE "format-indenter"
24 
25 namespace clang {
26 namespace format {
27 
28 // Returns true if a TT_SelectorName should be indented when wrapped,
29 // false otherwise.
30 static bool shouldIndentWrappedSelectorName(const FormatStyle &Style,
31                                             LineType LineType) {
32   return Style.IndentWrappedFunctionNames || LineType == LT_ObjCMethodDecl;
33 }
34 
35 // Returns the length of everything up to the first possible line break after
36 // the ), ], } or > matching \c Tok.
37 static unsigned getLengthToMatchingParen(const FormatToken &Tok,
38                                          const std::vector<ParenState> &Stack) {
39   // Normally whether or not a break before T is possible is calculated and
40   // stored in T.CanBreakBefore. Braces, array initializers and text proto
41   // messages like `key: < ... >` are an exception: a break is possible
42   // before a closing brace R if a break was inserted after the corresponding
43   // opening brace. The information about whether or not a break is needed
44   // before a closing brace R is stored in the ParenState field
45   // S.BreakBeforeClosingBrace where S is the state that R closes.
46   //
47   // In order to decide whether there can be a break before encountered right
48   // braces, this implementation iterates over the sequence of tokens and over
49   // the paren stack in lockstep, keeping track of the stack level which visited
50   // right braces correspond to in MatchingStackIndex.
51   //
52   // For example, consider:
53   // L. <- line number
54   // 1. {
55   // 2. {1},
56   // 3. {2},
57   // 4. {{3}}}
58   //     ^ where we call this method with this token.
59   // The paren stack at this point contains 3 brace levels:
60   //  0. { at line 1, BreakBeforeClosingBrace: true
61   //  1. first { at line 4, BreakBeforeClosingBrace: false
62   //  2. second { at line 4, BreakBeforeClosingBrace: false,
63   //  where there might be fake parens levels in-between these levels.
64   // The algorithm will start at the first } on line 4, which is the matching
65   // brace of the initial left brace and at level 2 of the stack. Then,
66   // examining BreakBeforeClosingBrace: false at level 2, it will continue to
67   // the second } on line 4, and will traverse the stack downwards until it
68   // finds the matching { on level 1. Then, examining BreakBeforeClosingBrace:
69   // false at level 1, it will continue to the third } on line 4 and will
70   // traverse the stack downwards until it finds the matching { on level 0.
71   // Then, examining BreakBeforeClosingBrace: true at level 0, the algorithm
72   // will stop and will use the second } on line 4 to determine the length to
73   // return, as in this example the range will include the tokens: {3}}
74   //
75   // The algorithm will only traverse the stack if it encounters braces, array
76   // initializer squares or text proto angle brackets.
77   if (!Tok.MatchingParen)
78     return 0;
79   FormatToken *End = Tok.MatchingParen;
80   // Maintains a stack level corresponding to the current End token.
81   int MatchingStackIndex = Stack.size() - 1;
82   // Traverses the stack downwards, looking for the level to which LBrace
83   // corresponds. Returns either a pointer to the matching level or nullptr if
84   // LParen is not found in the initial portion of the stack up to
85   // MatchingStackIndex.
86   auto FindParenState = [&](const FormatToken *LBrace) -> const ParenState * {
87     while (MatchingStackIndex >= 0 && Stack[MatchingStackIndex].Tok != LBrace)
88       --MatchingStackIndex;
89     return MatchingStackIndex >= 0 ? &Stack[MatchingStackIndex] : nullptr;
90   };
91   for (; End->Next; End = End->Next) {
92     if (End->Next->CanBreakBefore)
93       break;
94     if (!End->Next->closesScope())
95       continue;
96     if (End->Next->MatchingParen &&
97         End->Next->MatchingParen->isOneOf(
98             tok::l_brace, TT_ArrayInitializerLSquare, tok::less)) {
99       const ParenState *State = FindParenState(End->Next->MatchingParen);
100       if (State && State->BreakBeforeClosingBrace)
101         break;
102     }
103   }
104   return End->TotalLength - Tok.TotalLength + 1;
105 }
106 
107 static unsigned getLengthToNextOperator(const FormatToken &Tok) {
108   if (!Tok.NextOperator)
109     return 0;
110   return Tok.NextOperator->TotalLength - Tok.TotalLength;
111 }
112 
113 // Returns \c true if \c Tok is the "." or "->" of a call and starts the next
114 // segment of a builder type call.
115 static bool startsSegmentOfBuilderTypeCall(const FormatToken &Tok) {
116   return Tok.isMemberAccess() && Tok.Previous && Tok.Previous->closesScope();
117 }
118 
119 // Returns \c true if \c Current starts a new parameter.
120 static bool startsNextParameter(const FormatToken &Current,
121                                 const FormatStyle &Style) {
122   const FormatToken &Previous = *Current.Previous;
123   if (Current.is(TT_CtorInitializerComma) &&
124       Style.BreakConstructorInitializers == FormatStyle::BCIS_BeforeComma)
125     return true;
126   if (Style.Language == FormatStyle::LK_Proto && Current.is(TT_SelectorName))
127     return true;
128   return Previous.is(tok::comma) && !Current.isTrailingComment() &&
129          ((Previous.isNot(TT_CtorInitializerComma) ||
130            Style.BreakConstructorInitializers !=
131                FormatStyle::BCIS_BeforeComma) &&
132           (Previous.isNot(TT_InheritanceComma) ||
133            Style.BreakInheritanceList != FormatStyle::BILS_BeforeComma));
134 }
135 
136 static bool opensProtoMessageField(const FormatToken &LessTok,
137                                    const FormatStyle &Style) {
138   if (LessTok.isNot(tok::less))
139     return false;
140   return Style.Language == FormatStyle::LK_TextProto ||
141          (Style.Language == FormatStyle::LK_Proto &&
142           (LessTok.NestingLevel > 0 ||
143            (LessTok.Previous && LessTok.Previous->is(tok::equal))));
144 }
145 
146 // Returns the delimiter of a raw string literal, or None if TokenText is not
147 // the text of a raw string literal. The delimiter could be the empty string.
148 // For example, the delimiter of R"deli(cont)deli" is deli.
149 static llvm::Optional<StringRef> getRawStringDelimiter(StringRef TokenText) {
150   if (TokenText.size() < 5 // The smallest raw string possible is 'R"()"'.
151       || !TokenText.startswith("R\"") || !TokenText.endswith("\""))
152     return None;
153 
154   // A raw string starts with 'R"<delimiter>(' and delimiter is ascii and has
155   // size at most 16 by the standard, so the first '(' must be among the first
156   // 19 bytes.
157   size_t LParenPos = TokenText.substr(0, 19).find_first_of('(');
158   if (LParenPos == StringRef::npos)
159     return None;
160   StringRef Delimiter = TokenText.substr(2, LParenPos - 2);
161 
162   // Check that the string ends in ')Delimiter"'.
163   size_t RParenPos = TokenText.size() - Delimiter.size() - 2;
164   if (TokenText[RParenPos] != ')')
165     return None;
166   if (!TokenText.substr(RParenPos + 1).startswith(Delimiter))
167     return None;
168   return Delimiter;
169 }
170 
171 // Returns the canonical delimiter for \p Language, or the empty string if no
172 // canonical delimiter is specified.
173 static StringRef
174 getCanonicalRawStringDelimiter(const FormatStyle &Style,
175                                FormatStyle::LanguageKind Language) {
176   for (const auto &Format : Style.RawStringFormats) {
177     if (Format.Language == Language)
178       return StringRef(Format.CanonicalDelimiter);
179   }
180   return "";
181 }
182 
183 RawStringFormatStyleManager::RawStringFormatStyleManager(
184     const FormatStyle &CodeStyle) {
185   for (const auto &RawStringFormat : CodeStyle.RawStringFormats) {
186     llvm::Optional<FormatStyle> LanguageStyle =
187         CodeStyle.GetLanguageStyle(RawStringFormat.Language);
188     if (!LanguageStyle) {
189       FormatStyle PredefinedStyle;
190       if (!getPredefinedStyle(RawStringFormat.BasedOnStyle,
191                               RawStringFormat.Language, &PredefinedStyle)) {
192         PredefinedStyle = getLLVMStyle();
193         PredefinedStyle.Language = RawStringFormat.Language;
194       }
195       LanguageStyle = PredefinedStyle;
196     }
197     LanguageStyle->ColumnLimit = CodeStyle.ColumnLimit;
198     for (StringRef Delimiter : RawStringFormat.Delimiters) {
199       DelimiterStyle.insert({Delimiter, *LanguageStyle});
200     }
201     for (StringRef EnclosingFunction : RawStringFormat.EnclosingFunctions) {
202       EnclosingFunctionStyle.insert({EnclosingFunction, *LanguageStyle});
203     }
204   }
205 }
206 
207 llvm::Optional<FormatStyle>
208 RawStringFormatStyleManager::getDelimiterStyle(StringRef Delimiter) const {
209   auto It = DelimiterStyle.find(Delimiter);
210   if (It == DelimiterStyle.end())
211     return None;
212   return It->second;
213 }
214 
215 llvm::Optional<FormatStyle>
216 RawStringFormatStyleManager::getEnclosingFunctionStyle(
217     StringRef EnclosingFunction) const {
218   auto It = EnclosingFunctionStyle.find(EnclosingFunction);
219   if (It == EnclosingFunctionStyle.end())
220     return None;
221   return It->second;
222 }
223 
224 ContinuationIndenter::ContinuationIndenter(const FormatStyle &Style,
225                                            const AdditionalKeywords &Keywords,
226                                            const SourceManager &SourceMgr,
227                                            WhitespaceManager &Whitespaces,
228                                            encoding::Encoding Encoding,
229                                            bool BinPackInconclusiveFunctions)
230     : Style(Style), Keywords(Keywords), SourceMgr(SourceMgr),
231       Whitespaces(Whitespaces), Encoding(Encoding),
232       BinPackInconclusiveFunctions(BinPackInconclusiveFunctions),
233       CommentPragmasRegex(Style.CommentPragmas), RawStringFormats(Style) {}
234 
235 LineState ContinuationIndenter::getInitialState(unsigned FirstIndent,
236                                                 unsigned FirstStartColumn,
237                                                 const AnnotatedLine *Line,
238                                                 bool DryRun) {
239   LineState State;
240   State.FirstIndent = FirstIndent;
241   if (FirstStartColumn && Line->First->NewlinesBefore == 0)
242     State.Column = FirstStartColumn;
243   else
244     State.Column = FirstIndent;
245   // With preprocessor directive indentation, the line starts on column 0
246   // since it's indented after the hash, but FirstIndent is set to the
247   // preprocessor indent.
248   if (Style.IndentPPDirectives == FormatStyle::PPDIS_AfterHash &&
249       (Line->Type == LT_PreprocessorDirective ||
250        Line->Type == LT_ImportStatement))
251     State.Column = 0;
252   State.Line = Line;
253   State.NextToken = Line->First;
254   State.Stack.push_back(ParenState(/*Tok=*/nullptr, FirstIndent, FirstIndent,
255                                    /*AvoidBinPacking=*/false,
256                                    /*NoLineBreak=*/false));
257   State.LineContainsContinuedForLoopSection = false;
258   State.NoContinuation = false;
259   State.StartOfStringLiteral = 0;
260   State.StartOfLineLevel = 0;
261   State.LowestLevelOnLine = 0;
262   State.IgnoreStackForComparison = false;
263 
264   if (Style.Language == FormatStyle::LK_TextProto) {
265     // We need this in order to deal with the bin packing of text fields at
266     // global scope.
267     State.Stack.back().AvoidBinPacking = true;
268     State.Stack.back().BreakBeforeParameter = true;
269     State.Stack.back().AlignColons = false;
270   }
271 
272   // The first token has already been indented and thus consumed.
273   moveStateToNextToken(State, DryRun, /*Newline=*/false);
274   return State;
275 }
276 
277 bool ContinuationIndenter::canBreak(const LineState &State) {
278   const FormatToken &Current = *State.NextToken;
279   const FormatToken &Previous = *Current.Previous;
280   assert(&Previous == Current.Previous);
281   if (!Current.CanBreakBefore && !(State.Stack.back().BreakBeforeClosingBrace &&
282                                    Current.closesBlockOrBlockTypeList(Style)))
283     return false;
284   // The opening "{" of a braced list has to be on the same line as the first
285   // element if it is nested in another braced init list or function call.
286   if (!Current.MustBreakBefore && Previous.is(tok::l_brace) &&
287       Previous.isNot(TT_DictLiteral) && Previous.BlockKind == BK_BracedInit &&
288       Previous.Previous &&
289       Previous.Previous->isOneOf(tok::l_brace, tok::l_paren, tok::comma))
290     return false;
291   // This prevents breaks like:
292   //   ...
293   //   SomeParameter, OtherParameter).DoSomething(
294   //   ...
295   // As they hide "DoSomething" and are generally bad for readability.
296   if (Previous.opensScope() && Previous.isNot(tok::l_brace) &&
297       State.LowestLevelOnLine < State.StartOfLineLevel &&
298       State.LowestLevelOnLine < Current.NestingLevel)
299     return false;
300   if (Current.isMemberAccess() && State.Stack.back().ContainsUnwrappedBuilder)
301     return false;
302 
303   // Don't create a 'hanging' indent if there are multiple blocks in a single
304   // statement.
305   if (Previous.is(tok::l_brace) && State.Stack.size() > 1 &&
306       State.Stack[State.Stack.size() - 2].NestedBlockInlined &&
307       State.Stack[State.Stack.size() - 2].HasMultipleNestedBlocks)
308     return false;
309 
310   // Don't break after very short return types (e.g. "void") as that is often
311   // unexpected.
312   if (Current.is(TT_FunctionDeclarationName) && State.Column < 6) {
313     if (Style.AlwaysBreakAfterReturnType == FormatStyle::RTBS_None)
314       return false;
315   }
316 
317   // If binary operators are moved to the next line (including commas for some
318   // styles of constructor initializers), that's always ok.
319   if (!Current.isOneOf(TT_BinaryOperator, tok::comma) &&
320       State.Stack.back().NoLineBreakInOperand)
321     return false;
322 
323   if (Previous.is(tok::l_square) && Previous.is(TT_ObjCMethodExpr))
324     return false;
325 
326   return !State.Stack.back().NoLineBreak;
327 }
328 
329 bool ContinuationIndenter::mustBreak(const LineState &State) {
330   const FormatToken &Current = *State.NextToken;
331   const FormatToken &Previous = *Current.Previous;
332   if (Style.BraceWrapping.BeforeLambdaBody && Current.CanBreakBefore &&
333       Current.is(TT_LambdaLBrace) && Previous.isNot(TT_LineComment)) {
334     auto LambdaBodyLength = getLengthToMatchingParen(Current, State.Stack);
335     return (LambdaBodyLength > getColumnLimit(State));
336   }
337   if (Current.MustBreakBefore || Current.is(TT_InlineASMColon))
338     return true;
339   if (State.Stack.back().BreakBeforeClosingBrace &&
340       Current.closesBlockOrBlockTypeList(Style))
341     return true;
342   if (Previous.is(tok::semi) && State.LineContainsContinuedForLoopSection)
343     return true;
344   if (Style.Language == FormatStyle::LK_ObjC &&
345       Style.ObjCBreakBeforeNestedBlockParam &&
346       Current.ObjCSelectorNameParts > 1 &&
347       Current.startsSequence(TT_SelectorName, tok::colon, tok::caret)) {
348     return true;
349   }
350   // Avoid producing inconsistent states by requiring breaks where they are not
351   // permitted for C# generic type constraints.
352   if (State.Stack.back().IsCSharpGenericTypeConstraint &&
353       Previous.isNot(TT_CSharpGenericTypeConstraintComma))
354     return false;
355   if ((startsNextParameter(Current, Style) || Previous.is(tok::semi) ||
356        (Previous.is(TT_TemplateCloser) && Current.is(TT_StartOfName) &&
357         Style.isCpp() &&
358         // FIXME: This is a temporary workaround for the case where clang-format
359         // sets BreakBeforeParameter to avoid bin packing and this creates a
360         // completely unnecessary line break after a template type that isn't
361         // line-wrapped.
362         (Previous.NestingLevel == 1 || Style.BinPackParameters)) ||
363        (Style.BreakBeforeTernaryOperators && Current.is(TT_ConditionalExpr) &&
364         Previous.isNot(tok::question)) ||
365        (!Style.BreakBeforeTernaryOperators &&
366         Previous.is(TT_ConditionalExpr))) &&
367       State.Stack.back().BreakBeforeParameter && !Current.isTrailingComment() &&
368       !Current.isOneOf(tok::r_paren, tok::r_brace))
369     return true;
370   if (State.Stack.back().IsChainedConditional &&
371       ((Style.BreakBeforeTernaryOperators && Current.is(TT_ConditionalExpr) &&
372         Current.is(tok::colon)) ||
373        (!Style.BreakBeforeTernaryOperators && Previous.is(TT_ConditionalExpr) &&
374         Previous.is(tok::colon))))
375     return true;
376   if (((Previous.is(TT_DictLiteral) && Previous.is(tok::l_brace)) ||
377        (Previous.is(TT_ArrayInitializerLSquare) &&
378         Previous.ParameterCount > 1) ||
379        opensProtoMessageField(Previous, Style)) &&
380       Style.ColumnLimit > 0 &&
381       getLengthToMatchingParen(Previous, State.Stack) + State.Column - 1 >
382           getColumnLimit(State))
383     return true;
384 
385   const FormatToken &BreakConstructorInitializersToken =
386       Style.BreakConstructorInitializers == FormatStyle::BCIS_AfterColon
387           ? Previous
388           : Current;
389   if (BreakConstructorInitializersToken.is(TT_CtorInitializerColon) &&
390       (State.Column + State.Line->Last->TotalLength - Previous.TotalLength >
391            getColumnLimit(State) ||
392        State.Stack.back().BreakBeforeParameter) &&
393       (Style.AllowShortFunctionsOnASingleLine != FormatStyle::SFS_All ||
394        Style.BreakConstructorInitializers != FormatStyle::BCIS_BeforeColon ||
395        Style.ColumnLimit != 0))
396     return true;
397 
398   if (Current.is(TT_ObjCMethodExpr) && !Previous.is(TT_SelectorName) &&
399       State.Line->startsWith(TT_ObjCMethodSpecifier))
400     return true;
401   if (Current.is(TT_SelectorName) && !Previous.is(tok::at) &&
402       State.Stack.back().ObjCSelectorNameFound &&
403       State.Stack.back().BreakBeforeParameter)
404     return true;
405 
406   unsigned NewLineColumn = getNewLineColumn(State);
407   if (Current.isMemberAccess() && Style.ColumnLimit != 0 &&
408       State.Column + getLengthToNextOperator(Current) > Style.ColumnLimit &&
409       (State.Column > NewLineColumn ||
410        Current.NestingLevel < State.StartOfLineLevel))
411     return true;
412 
413   if (startsSegmentOfBuilderTypeCall(Current) &&
414       (State.Stack.back().CallContinuation != 0 ||
415        State.Stack.back().BreakBeforeParameter) &&
416       // JavaScript is treated different here as there is a frequent pattern:
417       //   SomeFunction(function() {
418       //     ...
419       //   }.bind(...));
420       // FIXME: We should find a more generic solution to this problem.
421       !(State.Column <= NewLineColumn &&
422         Style.Language == FormatStyle::LK_JavaScript) &&
423       !(Previous.closesScopeAfterBlock() && State.Column <= NewLineColumn))
424     return true;
425 
426   // If the template declaration spans multiple lines, force wrap before the
427   // function/class declaration
428   if (Previous.ClosesTemplateDeclaration &&
429       State.Stack.back().BreakBeforeParameter && Current.CanBreakBefore)
430     return true;
431 
432   if (!State.Line->First->is(tok::kw_enum) && State.Column <= NewLineColumn)
433     return false;
434 
435   if (Style.AlwaysBreakBeforeMultilineStrings &&
436       (NewLineColumn == State.FirstIndent + Style.ContinuationIndentWidth ||
437        Previous.is(tok::comma) || Current.NestingLevel < 2) &&
438       !Previous.isOneOf(tok::kw_return, tok::lessless, tok::at,
439                         Keywords.kw_dollar) &&
440       !Previous.isOneOf(TT_InlineASMColon, TT_ConditionalExpr) &&
441       nextIsMultilineString(State))
442     return true;
443 
444   // Using CanBreakBefore here and below takes care of the decision whether the
445   // current style uses wrapping before or after operators for the given
446   // operator.
447   if (Previous.is(TT_BinaryOperator) && Current.CanBreakBefore) {
448     // If we need to break somewhere inside the LHS of a binary expression, we
449     // should also break after the operator. Otherwise, the formatting would
450     // hide the operator precedence, e.g. in:
451     //   if (aaaaaaaaaaaaaa ==
452     //           bbbbbbbbbbbbbb && c) {..
453     // For comparisons, we only apply this rule, if the LHS is a binary
454     // expression itself as otherwise, the line breaks seem superfluous.
455     // We need special cases for ">>" which we have split into two ">" while
456     // lexing in order to make template parsing easier.
457     bool IsComparison = (Previous.getPrecedence() == prec::Relational ||
458                          Previous.getPrecedence() == prec::Equality ||
459                          Previous.getPrecedence() == prec::Spaceship) &&
460                         Previous.Previous &&
461                         Previous.Previous->isNot(TT_BinaryOperator); // For >>.
462     bool LHSIsBinaryExpr =
463         Previous.Previous && Previous.Previous->EndsBinaryExpression;
464     if ((!IsComparison || LHSIsBinaryExpr) && !Current.isTrailingComment() &&
465         Previous.getPrecedence() != prec::Assignment &&
466         State.Stack.back().BreakBeforeParameter)
467       return true;
468   } else if (Current.is(TT_BinaryOperator) && Current.CanBreakBefore &&
469              State.Stack.back().BreakBeforeParameter) {
470     return true;
471   }
472 
473   // Same as above, but for the first "<<" operator.
474   if (Current.is(tok::lessless) && Current.isNot(TT_OverloadedOperator) &&
475       State.Stack.back().BreakBeforeParameter &&
476       State.Stack.back().FirstLessLess == 0)
477     return true;
478 
479   if (Current.NestingLevel == 0 && !Current.isTrailingComment()) {
480     // Always break after "template <...>" and leading annotations. This is only
481     // for cases where the entire line does not fit on a single line as a
482     // different LineFormatter would be used otherwise.
483     if (Previous.ClosesTemplateDeclaration)
484       return Style.AlwaysBreakTemplateDeclarations != FormatStyle::BTDS_No;
485     if (Previous.is(TT_FunctionAnnotationRParen))
486       return true;
487     if (Previous.is(TT_LeadingJavaAnnotation) && Current.isNot(tok::l_paren) &&
488         Current.isNot(TT_LeadingJavaAnnotation))
489       return true;
490   }
491 
492   // If the return type spans multiple lines, wrap before the function name.
493   if (((Current.is(TT_FunctionDeclarationName) &&
494         // Don't break before a C# function when no break after return type
495         (!Style.isCSharp() ||
496          Style.AlwaysBreakAfterReturnType != FormatStyle::RTBS_None)) ||
497        (Current.is(tok::kw_operator) && !Previous.is(tok::coloncolon))) &&
498       !Previous.is(tok::kw_template) && State.Stack.back().BreakBeforeParameter)
499     return true;
500 
501   // The following could be precomputed as they do not depend on the state.
502   // However, as they should take effect only if the UnwrappedLine does not fit
503   // into the ColumnLimit, they are checked here in the ContinuationIndenter.
504   if (Style.ColumnLimit != 0 && Previous.BlockKind == BK_Block &&
505       Previous.is(tok::l_brace) && !Current.isOneOf(tok::r_brace, tok::comment))
506     return true;
507 
508   if (Current.is(tok::lessless) &&
509       ((Previous.is(tok::identifier) && Previous.TokenText == "endl") ||
510        (Previous.Tok.isLiteral() && (Previous.TokenText.endswith("\\n\"") ||
511                                      Previous.TokenText == "\'\\n\'"))))
512     return true;
513 
514   if (Previous.is(TT_BlockComment) && Previous.IsMultiline)
515     return true;
516 
517   if (State.NoContinuation)
518     return true;
519 
520   return false;
521 }
522 
523 unsigned ContinuationIndenter::addTokenToState(LineState &State, bool Newline,
524                                                bool DryRun,
525                                                unsigned ExtraSpaces) {
526   const FormatToken &Current = *State.NextToken;
527 
528   assert(!State.Stack.empty());
529   State.NoContinuation = false;
530 
531   if ((Current.is(TT_ImplicitStringLiteral) &&
532        (Current.Previous->Tok.getIdentifierInfo() == nullptr ||
533         Current.Previous->Tok.getIdentifierInfo()->getPPKeywordID() ==
534             tok::pp_not_keyword))) {
535     unsigned EndColumn =
536         SourceMgr.getSpellingColumnNumber(Current.WhitespaceRange.getEnd());
537     if (Current.LastNewlineOffset != 0) {
538       // If there is a newline within this token, the final column will solely
539       // determined by the current end column.
540       State.Column = EndColumn;
541     } else {
542       unsigned StartColumn =
543           SourceMgr.getSpellingColumnNumber(Current.WhitespaceRange.getBegin());
544       assert(EndColumn >= StartColumn);
545       State.Column += EndColumn - StartColumn;
546     }
547     moveStateToNextToken(State, DryRun, /*Newline=*/false);
548     return 0;
549   }
550 
551   unsigned Penalty = 0;
552   if (Newline)
553     Penalty = addTokenOnNewLine(State, DryRun);
554   else
555     addTokenOnCurrentLine(State, DryRun, ExtraSpaces);
556 
557   return moveStateToNextToken(State, DryRun, Newline) + Penalty;
558 }
559 
560 void ContinuationIndenter::addTokenOnCurrentLine(LineState &State, bool DryRun,
561                                                  unsigned ExtraSpaces) {
562   FormatToken &Current = *State.NextToken;
563   const FormatToken &Previous = *State.NextToken->Previous;
564   if (Current.is(tok::equal) &&
565       (State.Line->First->is(tok::kw_for) || Current.NestingLevel == 0) &&
566       State.Stack.back().VariablePos == 0) {
567     State.Stack.back().VariablePos = State.Column;
568     // Move over * and & if they are bound to the variable name.
569     const FormatToken *Tok = &Previous;
570     while (Tok && State.Stack.back().VariablePos >= Tok->ColumnWidth) {
571       State.Stack.back().VariablePos -= Tok->ColumnWidth;
572       if (Tok->SpacesRequiredBefore != 0)
573         break;
574       Tok = Tok->Previous;
575     }
576     if (Previous.PartOfMultiVariableDeclStmt)
577       State.Stack.back().LastSpace = State.Stack.back().VariablePos;
578   }
579 
580   unsigned Spaces = Current.SpacesRequiredBefore + ExtraSpaces;
581 
582   // Indent preprocessor directives after the hash if required.
583   int PPColumnCorrection = 0;
584   if (Style.IndentPPDirectives == FormatStyle::PPDIS_AfterHash &&
585       Previous.is(tok::hash) && State.FirstIndent > 0 &&
586       (State.Line->Type == LT_PreprocessorDirective ||
587        State.Line->Type == LT_ImportStatement)) {
588     Spaces += State.FirstIndent;
589 
590     // For preprocessor indent with tabs, State.Column will be 1 because of the
591     // hash. This causes second-level indents onward to have an extra space
592     // after the tabs. We avoid this misalignment by subtracting 1 from the
593     // column value passed to replaceWhitespace().
594     if (Style.UseTab != FormatStyle::UT_Never)
595       PPColumnCorrection = -1;
596   }
597 
598   if (!DryRun)
599     Whitespaces.replaceWhitespace(Current, /*Newlines=*/0, Spaces,
600                                   State.Column + Spaces + PPColumnCorrection);
601 
602   // If "BreakBeforeInheritanceComma" mode, don't break within the inheritance
603   // declaration unless there is multiple inheritance.
604   if (Style.BreakInheritanceList == FormatStyle::BILS_BeforeComma &&
605       Current.is(TT_InheritanceColon))
606     State.Stack.back().NoLineBreak = true;
607   if (Style.BreakInheritanceList == FormatStyle::BILS_AfterColon &&
608       Previous.is(TT_InheritanceColon))
609     State.Stack.back().NoLineBreak = true;
610 
611   if (Current.is(TT_SelectorName) &&
612       !State.Stack.back().ObjCSelectorNameFound) {
613     unsigned MinIndent =
614         std::max(State.FirstIndent + Style.ContinuationIndentWidth,
615                  State.Stack.back().Indent);
616     unsigned FirstColonPos = State.Column + Spaces + Current.ColumnWidth;
617     if (Current.LongestObjCSelectorName == 0)
618       State.Stack.back().AlignColons = false;
619     else if (MinIndent + Current.LongestObjCSelectorName > FirstColonPos)
620       State.Stack.back().ColonPos = MinIndent + Current.LongestObjCSelectorName;
621     else
622       State.Stack.back().ColonPos = FirstColonPos;
623   }
624 
625   // In "AlwaysBreak" mode, enforce wrapping directly after the parenthesis by
626   // disallowing any further line breaks if there is no line break after the
627   // opening parenthesis. Don't break if it doesn't conserve columns.
628   if (Style.AlignAfterOpenBracket == FormatStyle::BAS_AlwaysBreak &&
629       (Previous.isOneOf(tok::l_paren, TT_TemplateOpener, tok::l_square) ||
630        (Previous.is(tok::l_brace) && Previous.BlockKind != BK_Block &&
631         Style.Cpp11BracedListStyle)) &&
632       State.Column > getNewLineColumn(State) &&
633       (!Previous.Previous || !Previous.Previous->isOneOf(
634                                  tok::kw_for, tok::kw_while, tok::kw_switch)) &&
635       // Don't do this for simple (no expressions) one-argument function calls
636       // as that feels like needlessly wasting whitespace, e.g.:
637       //
638       //   caaaaaaaaaaaall(
639       //       caaaaaaaaaaaall(
640       //           caaaaaaaaaaaall(
641       //               caaaaaaaaaaaaaaaaaaaaaaall(aaaaaaaaaaaaaa, aaaaaaaaa))));
642       Current.FakeLParens.size() > 0 &&
643       Current.FakeLParens.back() > prec::Unknown)
644     State.Stack.back().NoLineBreak = true;
645   if (Previous.is(TT_TemplateString) && Previous.opensScope())
646     State.Stack.back().NoLineBreak = true;
647 
648   if (Style.AlignAfterOpenBracket != FormatStyle::BAS_DontAlign &&
649       !State.Stack.back().IsCSharpGenericTypeConstraint &&
650       Previous.opensScope() && Previous.isNot(TT_ObjCMethodExpr) &&
651       (Current.isNot(TT_LineComment) || Previous.BlockKind == BK_BracedInit)) {
652     State.Stack.back().Indent = State.Column + Spaces;
653     State.Stack.back().IsAligned = true;
654   }
655   if (State.Stack.back().AvoidBinPacking && startsNextParameter(Current, Style))
656     State.Stack.back().NoLineBreak = true;
657   if (startsSegmentOfBuilderTypeCall(Current) &&
658       State.Column > getNewLineColumn(State))
659     State.Stack.back().ContainsUnwrappedBuilder = true;
660 
661   if (Current.is(TT_LambdaArrow) && Style.Language == FormatStyle::LK_Java)
662     State.Stack.back().NoLineBreak = true;
663   if (Current.isMemberAccess() && Previous.is(tok::r_paren) &&
664       (Previous.MatchingParen &&
665        (Previous.TotalLength - Previous.MatchingParen->TotalLength > 10)))
666     // If there is a function call with long parameters, break before trailing
667     // calls. This prevents things like:
668     //   EXPECT_CALL(SomeLongParameter).Times(
669     //       2);
670     // We don't want to do this for short parameters as they can just be
671     // indexes.
672     State.Stack.back().NoLineBreak = true;
673 
674   // Don't allow the RHS of an operator to be split over multiple lines unless
675   // there is a line-break right after the operator.
676   // Exclude relational operators, as there, it is always more desirable to
677   // have the LHS 'left' of the RHS.
678   const FormatToken *P = Current.getPreviousNonComment();
679   if (!Current.is(tok::comment) && P &&
680       (P->isOneOf(TT_BinaryOperator, tok::comma) ||
681        (P->is(TT_ConditionalExpr) && P->is(tok::colon))) &&
682       !P->isOneOf(TT_OverloadedOperator, TT_CtorInitializerComma) &&
683       P->getPrecedence() != prec::Assignment &&
684       P->getPrecedence() != prec::Relational &&
685       P->getPrecedence() != prec::Spaceship) {
686     bool BreakBeforeOperator =
687         P->MustBreakBefore || P->is(tok::lessless) ||
688         (P->is(TT_BinaryOperator) &&
689          Style.BreakBeforeBinaryOperators != FormatStyle::BOS_None) ||
690         (P->is(TT_ConditionalExpr) && Style.BreakBeforeTernaryOperators);
691     // Don't do this if there are only two operands. In these cases, there is
692     // always a nice vertical separation between them and the extra line break
693     // does not help.
694     bool HasTwoOperands =
695         P->OperatorIndex == 0 && !P->NextOperator && !P->is(TT_ConditionalExpr);
696     if ((!BreakBeforeOperator &&
697          !(HasTwoOperands &&
698            Style.AlignOperands != FormatStyle::OAS_DontAlign)) ||
699         (!State.Stack.back().LastOperatorWrapped && BreakBeforeOperator))
700       State.Stack.back().NoLineBreakInOperand = true;
701   }
702 
703   State.Column += Spaces;
704   if (Current.isNot(tok::comment) && Previous.is(tok::l_paren) &&
705       Previous.Previous &&
706       (Previous.Previous->is(tok::kw_for) || Previous.Previous->isIf())) {
707     // Treat the condition inside an if as if it was a second function
708     // parameter, i.e. let nested calls have a continuation indent.
709     State.Stack.back().LastSpace = State.Column;
710     State.Stack.back().NestedBlockIndent = State.Column;
711   } else if (!Current.isOneOf(tok::comment, tok::caret) &&
712              ((Previous.is(tok::comma) &&
713                !Previous.is(TT_OverloadedOperator)) ||
714               (Previous.is(tok::colon) && Previous.is(TT_ObjCMethodExpr)))) {
715     State.Stack.back().LastSpace = State.Column;
716   } else if (Previous.is(TT_CtorInitializerColon) &&
717              Style.BreakConstructorInitializers ==
718                  FormatStyle::BCIS_AfterColon) {
719     State.Stack.back().Indent = State.Column;
720     State.Stack.back().LastSpace = State.Column;
721   } else if ((Previous.isOneOf(TT_BinaryOperator, TT_ConditionalExpr,
722                                TT_CtorInitializerColon)) &&
723              ((Previous.getPrecedence() != prec::Assignment &&
724                (Previous.isNot(tok::lessless) || Previous.OperatorIndex != 0 ||
725                 Previous.NextOperator)) ||
726               Current.StartsBinaryExpression)) {
727     // Indent relative to the RHS of the expression unless this is a simple
728     // assignment without binary expression on the RHS. Also indent relative to
729     // unary operators and the colons of constructor initializers.
730     if (Style.BreakBeforeBinaryOperators == FormatStyle::BOS_None)
731       State.Stack.back().LastSpace = State.Column;
732   } else if (Previous.is(TT_InheritanceColon)) {
733     State.Stack.back().Indent = State.Column;
734     State.Stack.back().LastSpace = State.Column;
735   } else if (Current.is(TT_CSharpGenericTypeConstraintColon)) {
736     State.Stack.back().ColonPos = State.Column;
737   } else if (Previous.opensScope()) {
738     // If a function has a trailing call, indent all parameters from the
739     // opening parenthesis. This avoids confusing indents like:
740     //   OuterFunction(InnerFunctionCall( // break
741     //       ParameterToInnerFunction))   // break
742     //       .SecondInnerFunctionCall();
743     bool HasTrailingCall = false;
744     if (Previous.MatchingParen) {
745       const FormatToken *Next = Previous.MatchingParen->getNextNonComment();
746       HasTrailingCall = Next && Next->isMemberAccess();
747     }
748     if (HasTrailingCall && State.Stack.size() > 1 &&
749         State.Stack[State.Stack.size() - 2].CallContinuation == 0)
750       State.Stack.back().LastSpace = State.Column;
751   }
752 }
753 
754 unsigned ContinuationIndenter::addTokenOnNewLine(LineState &State,
755                                                  bool DryRun) {
756   FormatToken &Current = *State.NextToken;
757   const FormatToken &Previous = *State.NextToken->Previous;
758 
759   // Extra penalty that needs to be added because of the way certain line
760   // breaks are chosen.
761   unsigned Penalty = 0;
762 
763   const FormatToken *PreviousNonComment = Current.getPreviousNonComment();
764   const FormatToken *NextNonComment = Previous.getNextNonComment();
765   if (!NextNonComment)
766     NextNonComment = &Current;
767   // The first line break on any NestingLevel causes an extra penalty in order
768   // prefer similar line breaks.
769   if (!State.Stack.back().ContainsLineBreak)
770     Penalty += 15;
771   State.Stack.back().ContainsLineBreak = true;
772 
773   Penalty += State.NextToken->SplitPenalty;
774 
775   // Breaking before the first "<<" is generally not desirable if the LHS is
776   // short. Also always add the penalty if the LHS is split over multiple lines
777   // to avoid unnecessary line breaks that just work around this penalty.
778   if (NextNonComment->is(tok::lessless) &&
779       State.Stack.back().FirstLessLess == 0 &&
780       (State.Column <= Style.ColumnLimit / 3 ||
781        State.Stack.back().BreakBeforeParameter))
782     Penalty += Style.PenaltyBreakFirstLessLess;
783 
784   State.Column = getNewLineColumn(State);
785 
786   // Indent nested blocks relative to this column, unless in a very specific
787   // JavaScript special case where:
788   //
789   //   var loooooong_name =
790   //       function() {
791   //     // code
792   //   }
793   //
794   // is common and should be formatted like a free-standing function. The same
795   // goes for wrapping before the lambda return type arrow.
796   if (!Current.is(TT_LambdaArrow) &&
797       (Style.Language != FormatStyle::LK_JavaScript ||
798        Current.NestingLevel != 0 || !PreviousNonComment ||
799        !PreviousNonComment->is(tok::equal) ||
800        !Current.isOneOf(Keywords.kw_async, Keywords.kw_function)))
801     State.Stack.back().NestedBlockIndent = State.Column;
802 
803   if (NextNonComment->isMemberAccess()) {
804     if (State.Stack.back().CallContinuation == 0)
805       State.Stack.back().CallContinuation = State.Column;
806   } else if (NextNonComment->is(TT_SelectorName)) {
807     if (!State.Stack.back().ObjCSelectorNameFound) {
808       if (NextNonComment->LongestObjCSelectorName == 0) {
809         State.Stack.back().AlignColons = false;
810       } else {
811         State.Stack.back().ColonPos =
812             (shouldIndentWrappedSelectorName(Style, State.Line->Type)
813                  ? std::max(State.Stack.back().Indent,
814                             State.FirstIndent + Style.ContinuationIndentWidth)
815                  : State.Stack.back().Indent) +
816             std::max(NextNonComment->LongestObjCSelectorName,
817                      NextNonComment->ColumnWidth);
818       }
819     } else if (State.Stack.back().AlignColons &&
820                State.Stack.back().ColonPos <= NextNonComment->ColumnWidth) {
821       State.Stack.back().ColonPos = State.Column + NextNonComment->ColumnWidth;
822     }
823   } else if (PreviousNonComment && PreviousNonComment->is(tok::colon) &&
824              PreviousNonComment->isOneOf(TT_ObjCMethodExpr, TT_DictLiteral)) {
825     // FIXME: This is hacky, find a better way. The problem is that in an ObjC
826     // method expression, the block should be aligned to the line starting it,
827     // e.g.:
828     //   [aaaaaaaaaaaaaaa aaaaaaaaa: \\ break for some reason
829     //                        ^(int *i) {
830     //                            // ...
831     //                        }];
832     // Thus, we set LastSpace of the next higher NestingLevel, to which we move
833     // when we consume all of the "}"'s FakeRParens at the "{".
834     if (State.Stack.size() > 1)
835       State.Stack[State.Stack.size() - 2].LastSpace =
836           std::max(State.Stack.back().LastSpace, State.Stack.back().Indent) +
837           Style.ContinuationIndentWidth;
838   }
839 
840   if ((PreviousNonComment &&
841        PreviousNonComment->isOneOf(tok::comma, tok::semi) &&
842        !State.Stack.back().AvoidBinPacking) ||
843       Previous.is(TT_BinaryOperator))
844     State.Stack.back().BreakBeforeParameter = false;
845   if (PreviousNonComment &&
846       PreviousNonComment->isOneOf(TT_TemplateCloser, TT_JavaAnnotation) &&
847       Current.NestingLevel == 0)
848     State.Stack.back().BreakBeforeParameter = false;
849   if (NextNonComment->is(tok::question) ||
850       (PreviousNonComment && PreviousNonComment->is(tok::question)))
851     State.Stack.back().BreakBeforeParameter = true;
852   if (Current.is(TT_BinaryOperator) && Current.CanBreakBefore)
853     State.Stack.back().BreakBeforeParameter = false;
854 
855   if (!DryRun) {
856     unsigned MaxEmptyLinesToKeep = Style.MaxEmptyLinesToKeep + 1;
857     if (Current.is(tok::r_brace) && Current.MatchingParen &&
858         // Only strip trailing empty lines for l_braces that have children, i.e.
859         // for function expressions (lambdas, arrows, etc).
860         !Current.MatchingParen->Children.empty()) {
861       // lambdas and arrow functions are expressions, thus their r_brace is not
862       // on its own line, and thus not covered by UnwrappedLineFormatter's logic
863       // about removing empty lines on closing blocks. Special case them here.
864       MaxEmptyLinesToKeep = 1;
865     }
866     unsigned Newlines =
867         std::max(1u, std::min(Current.NewlinesBefore, MaxEmptyLinesToKeep));
868     bool ContinuePPDirective =
869         State.Line->InPPDirective && State.Line->Type != LT_ImportStatement;
870     Whitespaces.replaceWhitespace(Current, Newlines, State.Column, State.Column,
871                                   State.Stack.back().IsAligned,
872                                   ContinuePPDirective);
873   }
874 
875   if (!Current.isTrailingComment())
876     State.Stack.back().LastSpace = State.Column;
877   if (Current.is(tok::lessless))
878     // If we are breaking before a "<<", we always want to indent relative to
879     // RHS. This is necessary only for "<<", as we special-case it and don't
880     // always indent relative to the RHS.
881     State.Stack.back().LastSpace += 3; // 3 -> width of "<< ".
882 
883   State.StartOfLineLevel = Current.NestingLevel;
884   State.LowestLevelOnLine = Current.NestingLevel;
885 
886   // Any break on this level means that the parent level has been broken
887   // and we need to avoid bin packing there.
888   bool NestedBlockSpecialCase =
889       (!Style.isCpp() && Current.is(tok::r_brace) && State.Stack.size() > 1 &&
890        State.Stack[State.Stack.size() - 2].NestedBlockInlined) ||
891       (Style.Language == FormatStyle::LK_ObjC && Current.is(tok::r_brace) &&
892        State.Stack.size() > 1 && !Style.ObjCBreakBeforeNestedBlockParam);
893   if (!NestedBlockSpecialCase)
894     for (unsigned i = 0, e = State.Stack.size() - 1; i != e; ++i)
895       State.Stack[i].BreakBeforeParameter = true;
896 
897   if (PreviousNonComment &&
898       !PreviousNonComment->isOneOf(tok::comma, tok::colon, tok::semi) &&
899       (PreviousNonComment->isNot(TT_TemplateCloser) ||
900        Current.NestingLevel != 0) &&
901       !PreviousNonComment->isOneOf(
902           TT_BinaryOperator, TT_FunctionAnnotationRParen, TT_JavaAnnotation,
903           TT_LeadingJavaAnnotation) &&
904       Current.isNot(TT_BinaryOperator) && !PreviousNonComment->opensScope())
905     State.Stack.back().BreakBeforeParameter = true;
906 
907   // If we break after { or the [ of an array initializer, we should also break
908   // before the corresponding } or ].
909   if (PreviousNonComment &&
910       (PreviousNonComment->isOneOf(tok::l_brace, TT_ArrayInitializerLSquare) ||
911        opensProtoMessageField(*PreviousNonComment, Style)))
912     State.Stack.back().BreakBeforeClosingBrace = true;
913 
914   if (State.Stack.back().AvoidBinPacking) {
915     // If we are breaking after '(', '{', '<', or this is the break after a ':'
916     // to start a member initializater list in a constructor, this should not
917     // be considered bin packing unless the relevant AllowAll option is false or
918     // this is a dict/object literal.
919     bool PreviousIsBreakingCtorInitializerColon =
920         Previous.is(TT_CtorInitializerColon) &&
921         Style.BreakConstructorInitializers == FormatStyle::BCIS_AfterColon;
922     if (!(Previous.isOneOf(tok::l_paren, tok::l_brace, TT_BinaryOperator) ||
923           PreviousIsBreakingCtorInitializerColon) ||
924         (!Style.AllowAllParametersOfDeclarationOnNextLine &&
925          State.Line->MustBeDeclaration) ||
926         (!Style.AllowAllArgumentsOnNextLine &&
927          !State.Line->MustBeDeclaration) ||
928         (!Style.AllowAllConstructorInitializersOnNextLine &&
929          PreviousIsBreakingCtorInitializerColon) ||
930         Previous.is(TT_DictLiteral))
931       State.Stack.back().BreakBeforeParameter = true;
932 
933     // If we are breaking after a ':' to start a member initializer list,
934     // and we allow all arguments on the next line, we should not break
935     // before the next parameter.
936     if (PreviousIsBreakingCtorInitializerColon &&
937         Style.AllowAllConstructorInitializersOnNextLine)
938       State.Stack.back().BreakBeforeParameter = false;
939   }
940 
941   return Penalty;
942 }
943 
944 unsigned ContinuationIndenter::getNewLineColumn(const LineState &State) {
945   if (!State.NextToken || !State.NextToken->Previous)
946     return 0;
947 
948   FormatToken &Current = *State.NextToken;
949 
950   if (State.Stack.back().IsCSharpGenericTypeConstraint &&
951       Current.isNot(TT_CSharpGenericTypeConstraint))
952     return State.Stack.back().ColonPos + 2;
953 
954   const FormatToken &Previous = *Current.Previous;
955   // If we are continuing an expression, we want to use the continuation indent.
956   unsigned ContinuationIndent =
957       std::max(State.Stack.back().LastSpace, State.Stack.back().Indent) +
958       Style.ContinuationIndentWidth;
959   const FormatToken *PreviousNonComment = Current.getPreviousNonComment();
960   const FormatToken *NextNonComment = Previous.getNextNonComment();
961   if (!NextNonComment)
962     NextNonComment = &Current;
963 
964   // Java specific bits.
965   if (Style.Language == FormatStyle::LK_Java &&
966       Current.isOneOf(Keywords.kw_implements, Keywords.kw_extends))
967     return std::max(State.Stack.back().LastSpace,
968                     State.Stack.back().Indent + Style.ContinuationIndentWidth);
969 
970   if (Style.BreakBeforeBraces == FormatStyle::BS_Whitesmiths &&
971       State.Line->First->is(tok::kw_enum))
972     return (Style.IndentWidth * State.Line->First->IndentLevel) +
973            Style.IndentWidth;
974 
975   if (NextNonComment->is(tok::l_brace) && NextNonComment->BlockKind == BK_Block)
976     return Current.NestingLevel == 0 ? State.FirstIndent
977                                      : State.Stack.back().Indent;
978   if ((Current.isOneOf(tok::r_brace, tok::r_square) ||
979        (Current.is(tok::greater) &&
980         (Style.Language == FormatStyle::LK_Proto ||
981          Style.Language == FormatStyle::LK_TextProto))) &&
982       State.Stack.size() > 1) {
983     if (Current.closesBlockOrBlockTypeList(Style))
984       return State.Stack[State.Stack.size() - 2].NestedBlockIndent;
985     if (Current.MatchingParen &&
986         Current.MatchingParen->BlockKind == BK_BracedInit)
987       return State.Stack[State.Stack.size() - 2].LastSpace;
988     return State.FirstIndent;
989   }
990   // Indent a closing parenthesis at the previous level if followed by a semi,
991   // const, or opening brace. This allows indentations such as:
992   //     foo(
993   //       a,
994   //     );
995   //     int Foo::getter(
996   //         //
997   //     ) const {
998   //       return foo;
999   //     }
1000   //     function foo(
1001   //       a,
1002   //     ) {
1003   //       code(); //
1004   //     }
1005   if (Current.is(tok::r_paren) && State.Stack.size() > 1 &&
1006       (!Current.Next ||
1007        Current.Next->isOneOf(tok::semi, tok::kw_const, tok::l_brace)))
1008     return State.Stack[State.Stack.size() - 2].LastSpace;
1009   if (NextNonComment->is(TT_TemplateString) && NextNonComment->closesScope())
1010     return State.Stack[State.Stack.size() - 2].LastSpace;
1011   if (Current.is(tok::identifier) && Current.Next &&
1012       (Current.Next->is(TT_DictLiteral) ||
1013        ((Style.Language == FormatStyle::LK_Proto ||
1014          Style.Language == FormatStyle::LK_TextProto) &&
1015         Current.Next->isOneOf(tok::less, tok::l_brace))))
1016     return State.Stack.back().Indent;
1017   if (NextNonComment->is(TT_ObjCStringLiteral) &&
1018       State.StartOfStringLiteral != 0)
1019     return State.StartOfStringLiteral - 1;
1020   if (NextNonComment->isStringLiteral() && State.StartOfStringLiteral != 0)
1021     return State.StartOfStringLiteral;
1022   if (NextNonComment->is(tok::lessless) &&
1023       State.Stack.back().FirstLessLess != 0)
1024     return State.Stack.back().FirstLessLess;
1025   if (NextNonComment->isMemberAccess()) {
1026     if (State.Stack.back().CallContinuation == 0)
1027       return ContinuationIndent;
1028     return State.Stack.back().CallContinuation;
1029   }
1030   if (State.Stack.back().QuestionColumn != 0 &&
1031       ((NextNonComment->is(tok::colon) &&
1032         NextNonComment->is(TT_ConditionalExpr)) ||
1033        Previous.is(TT_ConditionalExpr))) {
1034     if (((NextNonComment->is(tok::colon) && NextNonComment->Next &&
1035           !NextNonComment->Next->FakeLParens.empty() &&
1036           NextNonComment->Next->FakeLParens.back() == prec::Conditional) ||
1037          (Previous.is(tok::colon) && !Current.FakeLParens.empty() &&
1038           Current.FakeLParens.back() == prec::Conditional)) &&
1039         !State.Stack.back().IsWrappedConditional) {
1040       // NOTE: we may tweak this slightly:
1041       //    * not remove the 'lead' ContinuationIndentWidth
1042       //    * always un-indent by the operator when
1043       //    BreakBeforeTernaryOperators=true
1044       unsigned Indent = State.Stack.back().Indent;
1045       if (Style.AlignOperands != FormatStyle::OAS_DontAlign) {
1046         Indent -= Style.ContinuationIndentWidth;
1047       }
1048       if (Style.BreakBeforeTernaryOperators &&
1049           State.Stack.back().UnindentOperator)
1050         Indent -= 2;
1051       return Indent;
1052     }
1053     return State.Stack.back().QuestionColumn;
1054   }
1055   if (Previous.is(tok::comma) && State.Stack.back().VariablePos != 0)
1056     return State.Stack.back().VariablePos;
1057   if ((PreviousNonComment &&
1058        (PreviousNonComment->ClosesTemplateDeclaration ||
1059         PreviousNonComment->isOneOf(
1060             TT_AttributeParen, TT_AttributeSquare, TT_FunctionAnnotationRParen,
1061             TT_JavaAnnotation, TT_LeadingJavaAnnotation))) ||
1062       (!Style.IndentWrappedFunctionNames &&
1063        NextNonComment->isOneOf(tok::kw_operator, TT_FunctionDeclarationName)))
1064     return std::max(State.Stack.back().LastSpace, State.Stack.back().Indent);
1065   if (NextNonComment->is(TT_SelectorName)) {
1066     if (!State.Stack.back().ObjCSelectorNameFound) {
1067       unsigned MinIndent = State.Stack.back().Indent;
1068       if (shouldIndentWrappedSelectorName(Style, State.Line->Type))
1069         MinIndent = std::max(MinIndent,
1070                              State.FirstIndent + Style.ContinuationIndentWidth);
1071       // If LongestObjCSelectorName is 0, we are indenting the first
1072       // part of an ObjC selector (or a selector component which is
1073       // not colon-aligned due to block formatting).
1074       //
1075       // Otherwise, we are indenting a subsequent part of an ObjC
1076       // selector which should be colon-aligned to the longest
1077       // component of the ObjC selector.
1078       //
1079       // In either case, we want to respect Style.IndentWrappedFunctionNames.
1080       return MinIndent +
1081              std::max(NextNonComment->LongestObjCSelectorName,
1082                       NextNonComment->ColumnWidth) -
1083              NextNonComment->ColumnWidth;
1084     }
1085     if (!State.Stack.back().AlignColons)
1086       return State.Stack.back().Indent;
1087     if (State.Stack.back().ColonPos > NextNonComment->ColumnWidth)
1088       return State.Stack.back().ColonPos - NextNonComment->ColumnWidth;
1089     return State.Stack.back().Indent;
1090   }
1091   if (NextNonComment->is(tok::colon) && NextNonComment->is(TT_ObjCMethodExpr))
1092     return State.Stack.back().ColonPos;
1093   if (NextNonComment->is(TT_ArraySubscriptLSquare)) {
1094     if (State.Stack.back().StartOfArraySubscripts != 0)
1095       return State.Stack.back().StartOfArraySubscripts;
1096     else if (Style.isCSharp()) // C# allows `["key"] = value` inside object
1097                                // initializers.
1098       return State.Stack.back().Indent;
1099     return ContinuationIndent;
1100   }
1101 
1102   // This ensure that we correctly format ObjC methods calls without inputs,
1103   // i.e. where the last element isn't selector like: [callee method];
1104   if (NextNonComment->is(tok::identifier) && NextNonComment->FakeRParens == 0 &&
1105       NextNonComment->Next && NextNonComment->Next->is(TT_ObjCMethodExpr))
1106     return State.Stack.back().Indent;
1107 
1108   if (NextNonComment->isOneOf(TT_StartOfName, TT_PointerOrReference) ||
1109       Previous.isOneOf(tok::coloncolon, tok::equal, TT_JsTypeColon))
1110     return ContinuationIndent;
1111   if (PreviousNonComment && PreviousNonComment->is(tok::colon) &&
1112       PreviousNonComment->isOneOf(TT_ObjCMethodExpr, TT_DictLiteral))
1113     return ContinuationIndent;
1114   if (NextNonComment->is(TT_CtorInitializerComma))
1115     return State.Stack.back().Indent;
1116   if (PreviousNonComment && PreviousNonComment->is(TT_CtorInitializerColon) &&
1117       Style.BreakConstructorInitializers == FormatStyle::BCIS_AfterColon)
1118     return State.Stack.back().Indent;
1119   if (PreviousNonComment && PreviousNonComment->is(TT_InheritanceColon) &&
1120       Style.BreakInheritanceList == FormatStyle::BILS_AfterColon)
1121     return State.Stack.back().Indent;
1122   if (NextNonComment->isOneOf(TT_CtorInitializerColon, TT_InheritanceColon,
1123                               TT_InheritanceComma))
1124     return State.FirstIndent + Style.ConstructorInitializerIndentWidth;
1125   if (Previous.is(tok::r_paren) && !Current.isBinaryOperator() &&
1126       !Current.isOneOf(tok::colon, tok::comment))
1127     return ContinuationIndent;
1128   if (Current.is(TT_ProtoExtensionLSquare))
1129     return State.Stack.back().Indent;
1130   if (Current.isBinaryOperator() && State.Stack.back().UnindentOperator)
1131     return State.Stack.back().Indent - Current.Tok.getLength() -
1132            Current.SpacesRequiredBefore;
1133   if (Current.isOneOf(tok::comment, TT_BlockComment, TT_LineComment) &&
1134       NextNonComment->isBinaryOperator() && State.Stack.back().UnindentOperator)
1135     return State.Stack.back().Indent - NextNonComment->Tok.getLength() -
1136            NextNonComment->SpacesRequiredBefore;
1137   if (State.Stack.back().Indent == State.FirstIndent && PreviousNonComment &&
1138       !PreviousNonComment->isOneOf(tok::r_brace, TT_CtorInitializerComma))
1139     // Ensure that we fall back to the continuation indent width instead of
1140     // just flushing continuations left.
1141     return State.Stack.back().Indent + Style.ContinuationIndentWidth;
1142   return State.Stack.back().Indent;
1143 }
1144 
1145 static bool hasNestedBlockInlined(const FormatToken *Previous,
1146                                   const FormatToken &Current,
1147                                   const FormatStyle &Style) {
1148   if (Previous->isNot(tok::l_paren))
1149     return true;
1150   if (Previous->ParameterCount > 1)
1151     return true;
1152 
1153   // Also a nested block if contains a lambda inside function with 1 parameter
1154   return (Style.BraceWrapping.BeforeLambdaBody && Current.is(TT_LambdaLSquare));
1155 }
1156 
1157 unsigned ContinuationIndenter::moveStateToNextToken(LineState &State,
1158                                                     bool DryRun, bool Newline) {
1159   assert(State.Stack.size());
1160   const FormatToken &Current = *State.NextToken;
1161 
1162   if (Current.is(TT_CSharpGenericTypeConstraint))
1163     State.Stack.back().IsCSharpGenericTypeConstraint = true;
1164   if (Current.isOneOf(tok::comma, TT_BinaryOperator))
1165     State.Stack.back().NoLineBreakInOperand = false;
1166   if (Current.isOneOf(TT_InheritanceColon, TT_CSharpGenericTypeConstraintColon))
1167     State.Stack.back().AvoidBinPacking = true;
1168   if (Current.is(tok::lessless) && Current.isNot(TT_OverloadedOperator)) {
1169     if (State.Stack.back().FirstLessLess == 0)
1170       State.Stack.back().FirstLessLess = State.Column;
1171     else
1172       State.Stack.back().LastOperatorWrapped = Newline;
1173   }
1174   if (Current.is(TT_BinaryOperator) && Current.isNot(tok::lessless))
1175     State.Stack.back().LastOperatorWrapped = Newline;
1176   if (Current.is(TT_ConditionalExpr) && Current.Previous &&
1177       !Current.Previous->is(TT_ConditionalExpr))
1178     State.Stack.back().LastOperatorWrapped = Newline;
1179   if (Current.is(TT_ArraySubscriptLSquare) &&
1180       State.Stack.back().StartOfArraySubscripts == 0)
1181     State.Stack.back().StartOfArraySubscripts = State.Column;
1182   if (Current.is(TT_ConditionalExpr) && Current.is(tok::question) &&
1183       ((Current.MustBreakBefore) ||
1184        (Current.getNextNonComment() &&
1185         Current.getNextNonComment()->MustBreakBefore)))
1186     State.Stack.back().IsWrappedConditional = true;
1187   if (Style.BreakBeforeTernaryOperators && Current.is(tok::question))
1188     State.Stack.back().QuestionColumn = State.Column;
1189   if (!Style.BreakBeforeTernaryOperators && Current.isNot(tok::colon)) {
1190     const FormatToken *Previous = Current.Previous;
1191     while (Previous && Previous->isTrailingComment())
1192       Previous = Previous->Previous;
1193     if (Previous && Previous->is(tok::question))
1194       State.Stack.back().QuestionColumn = State.Column;
1195   }
1196   if (!Current.opensScope() && !Current.closesScope() &&
1197       !Current.is(TT_PointerOrReference))
1198     State.LowestLevelOnLine =
1199         std::min(State.LowestLevelOnLine, Current.NestingLevel);
1200   if (Current.isMemberAccess())
1201     State.Stack.back().StartOfFunctionCall =
1202         !Current.NextOperator ? 0 : State.Column;
1203   if (Current.is(TT_SelectorName))
1204     State.Stack.back().ObjCSelectorNameFound = true;
1205   if (Current.is(TT_CtorInitializerColon) &&
1206       Style.BreakConstructorInitializers != FormatStyle::BCIS_AfterColon) {
1207     // Indent 2 from the column, so:
1208     // SomeClass::SomeClass()
1209     //     : First(...), ...
1210     //       Next(...)
1211     //       ^ line up here.
1212     State.Stack.back().Indent =
1213         State.Column +
1214         (Style.BreakConstructorInitializers == FormatStyle::BCIS_BeforeComma
1215              ? 0
1216              : 2);
1217     State.Stack.back().NestedBlockIndent = State.Stack.back().Indent;
1218     if (Style.ConstructorInitializerAllOnOneLineOrOnePerLine) {
1219       State.Stack.back().AvoidBinPacking = true;
1220       State.Stack.back().BreakBeforeParameter =
1221           !Style.AllowAllConstructorInitializersOnNextLine;
1222     } else {
1223       State.Stack.back().BreakBeforeParameter = false;
1224     }
1225   }
1226   if (Current.is(TT_CtorInitializerColon) &&
1227       Style.BreakConstructorInitializers == FormatStyle::BCIS_AfterColon) {
1228     State.Stack.back().Indent =
1229         State.FirstIndent + Style.ConstructorInitializerIndentWidth;
1230     State.Stack.back().NestedBlockIndent = State.Stack.back().Indent;
1231     if (Style.ConstructorInitializerAllOnOneLineOrOnePerLine)
1232       State.Stack.back().AvoidBinPacking = true;
1233   }
1234   if (Current.is(TT_InheritanceColon))
1235     State.Stack.back().Indent =
1236         State.FirstIndent + Style.ConstructorInitializerIndentWidth;
1237   if (Current.isOneOf(TT_BinaryOperator, TT_ConditionalExpr) && Newline)
1238     State.Stack.back().NestedBlockIndent =
1239         State.Column + Current.ColumnWidth + 1;
1240   if (Current.isOneOf(TT_LambdaLSquare, TT_LambdaArrow))
1241     State.Stack.back().LastSpace = State.Column;
1242 
1243   // Insert scopes created by fake parenthesis.
1244   const FormatToken *Previous = Current.getPreviousNonComment();
1245 
1246   // Add special behavior to support a format commonly used for JavaScript
1247   // closures:
1248   //   SomeFunction(function() {
1249   //     foo();
1250   //     bar();
1251   //   }, a, b, c);
1252   if (Current.isNot(tok::comment) && Previous &&
1253       Previous->isOneOf(tok::l_brace, TT_ArrayInitializerLSquare) &&
1254       !Previous->is(TT_DictLiteral) && State.Stack.size() > 1 &&
1255       !State.Stack.back().HasMultipleNestedBlocks) {
1256     if (State.Stack[State.Stack.size() - 2].NestedBlockInlined && Newline)
1257       for (unsigned i = 0, e = State.Stack.size() - 1; i != e; ++i)
1258         State.Stack[i].NoLineBreak = true;
1259     State.Stack[State.Stack.size() - 2].NestedBlockInlined = false;
1260   }
1261   if (Previous &&
1262       (Previous->isOneOf(tok::l_paren, tok::comma, tok::colon) ||
1263        Previous->isOneOf(TT_BinaryOperator, TT_ConditionalExpr)) &&
1264       !Previous->isOneOf(TT_DictLiteral, TT_ObjCMethodExpr)) {
1265     State.Stack.back().NestedBlockInlined =
1266         !Newline && hasNestedBlockInlined(Previous, Current, Style);
1267   }
1268 
1269   moveStatePastFakeLParens(State, Newline);
1270   moveStatePastScopeCloser(State);
1271   bool AllowBreak = !State.Stack.back().NoLineBreak &&
1272                     !State.Stack.back().NoLineBreakInOperand;
1273   moveStatePastScopeOpener(State, Newline);
1274   moveStatePastFakeRParens(State);
1275 
1276   if (Current.is(TT_ObjCStringLiteral) && State.StartOfStringLiteral == 0)
1277     State.StartOfStringLiteral = State.Column + 1;
1278   if (Current.is(TT_CSharpStringLiteral) && State.StartOfStringLiteral == 0)
1279     State.StartOfStringLiteral = State.Column + 1;
1280   else if (Current.isStringLiteral() && State.StartOfStringLiteral == 0)
1281     State.StartOfStringLiteral = State.Column;
1282   else if (!Current.isOneOf(tok::comment, tok::identifier, tok::hash) &&
1283            !Current.isStringLiteral())
1284     State.StartOfStringLiteral = 0;
1285 
1286   State.Column += Current.ColumnWidth;
1287   State.NextToken = State.NextToken->Next;
1288 
1289   unsigned Penalty =
1290       handleEndOfLine(Current, State, DryRun, AllowBreak, Newline);
1291 
1292   if (Current.Role)
1293     Current.Role->formatFromToken(State, this, DryRun);
1294   // If the previous has a special role, let it consume tokens as appropriate.
1295   // It is necessary to start at the previous token for the only implemented
1296   // role (comma separated list). That way, the decision whether or not to break
1297   // after the "{" is already done and both options are tried and evaluated.
1298   // FIXME: This is ugly, find a better way.
1299   if (Previous && Previous->Role)
1300     Penalty += Previous->Role->formatAfterToken(State, this, DryRun);
1301 
1302   return Penalty;
1303 }
1304 
1305 void ContinuationIndenter::moveStatePastFakeLParens(LineState &State,
1306                                                     bool Newline) {
1307   const FormatToken &Current = *State.NextToken;
1308   const FormatToken *Previous = Current.getPreviousNonComment();
1309 
1310   // Don't add extra indentation for the first fake parenthesis after
1311   // 'return', assignments or opening <({[. The indentation for these cases
1312   // is special cased.
1313   bool SkipFirstExtraIndent =
1314       (Previous && (Previous->opensScope() ||
1315                     Previous->isOneOf(tok::semi, tok::kw_return) ||
1316                     (Previous->getPrecedence() == prec::Assignment &&
1317                      Style.AlignOperands != FormatStyle::OAS_DontAlign) ||
1318                     Previous->is(TT_ObjCMethodExpr)));
1319   for (SmallVectorImpl<prec::Level>::const_reverse_iterator
1320            I = Current.FakeLParens.rbegin(),
1321            E = Current.FakeLParens.rend();
1322        I != E; ++I) {
1323     ParenState NewParenState = State.Stack.back();
1324     NewParenState.Tok = nullptr;
1325     NewParenState.ContainsLineBreak = false;
1326     NewParenState.LastOperatorWrapped = true;
1327     NewParenState.IsChainedConditional = false;
1328     NewParenState.IsWrappedConditional = false;
1329     NewParenState.UnindentOperator = false;
1330     NewParenState.NoLineBreak =
1331         NewParenState.NoLineBreak || State.Stack.back().NoLineBreakInOperand;
1332 
1333     // Don't propagate AvoidBinPacking into subexpressions of arg/param lists.
1334     if (*I > prec::Comma)
1335       NewParenState.AvoidBinPacking = false;
1336 
1337     // Indent from 'LastSpace' unless these are fake parentheses encapsulating
1338     // a builder type call after 'return' or, if the alignment after opening
1339     // brackets is disabled.
1340     if (!Current.isTrailingComment() &&
1341         (Style.AlignOperands != FormatStyle::OAS_DontAlign ||
1342          *I < prec::Assignment) &&
1343         (!Previous || Previous->isNot(tok::kw_return) ||
1344          (Style.Language != FormatStyle::LK_Java && *I > 0)) &&
1345         (Style.AlignAfterOpenBracket != FormatStyle::BAS_DontAlign ||
1346          *I != prec::Comma || Current.NestingLevel == 0)) {
1347       NewParenState.Indent =
1348           std::max(std::max(State.Column, NewParenState.Indent),
1349                    State.Stack.back().LastSpace);
1350     }
1351 
1352     // If BreakBeforeBinaryOperators is set, un-indent a bit to account for
1353     // the operator and keep the operands aligned
1354     if (Style.AlignOperands == FormatStyle::OAS_AlignAfterOperator &&
1355         Previous &&
1356         (Previous->getPrecedence() == prec::Assignment ||
1357          Previous->is(tok::kw_return) ||
1358          (*I == prec::Conditional && Previous->is(tok::question) &&
1359           Previous->is(TT_ConditionalExpr))) &&
1360         !Newline)
1361       NewParenState.UnindentOperator = true;
1362 
1363     // Do not indent relative to the fake parentheses inserted for "." or "->".
1364     // This is a special case to make the following to statements consistent:
1365     //   OuterFunction(InnerFunctionCall( // break
1366     //       ParameterToInnerFunction));
1367     //   OuterFunction(SomeObject.InnerFunctionCall( // break
1368     //       ParameterToInnerFunction));
1369     if (*I > prec::Unknown)
1370       NewParenState.LastSpace = std::max(NewParenState.LastSpace, State.Column);
1371     if (*I != prec::Conditional && !Current.is(TT_UnaryOperator) &&
1372         Style.AlignAfterOpenBracket != FormatStyle::BAS_DontAlign)
1373       NewParenState.StartOfFunctionCall = State.Column;
1374 
1375     // Indent conditional expressions, unless they are chained "else-if"
1376     // conditionals. Never indent expression where the 'operator' is ',', ';' or
1377     // an assignment (i.e. *I <= prec::Assignment) as those have different
1378     // indentation rules. Indent other expression, unless the indentation needs
1379     // to be skipped.
1380     if (*I == prec::Conditional && Previous && Previous->is(tok::colon) &&
1381         Previous->is(TT_ConditionalExpr) && I == Current.FakeLParens.rbegin() &&
1382         !State.Stack.back().IsWrappedConditional) {
1383       NewParenState.IsChainedConditional = true;
1384       NewParenState.UnindentOperator = State.Stack.back().UnindentOperator;
1385     } else if (*I == prec::Conditional ||
1386                (!SkipFirstExtraIndent && *I > prec::Assignment &&
1387                 !Current.isTrailingComment())) {
1388       NewParenState.Indent += Style.ContinuationIndentWidth;
1389     }
1390     if ((Previous && !Previous->opensScope()) || *I != prec::Comma)
1391       NewParenState.BreakBeforeParameter = false;
1392     State.Stack.push_back(NewParenState);
1393     SkipFirstExtraIndent = false;
1394   }
1395 }
1396 
1397 void ContinuationIndenter::moveStatePastFakeRParens(LineState &State) {
1398   for (unsigned i = 0, e = State.NextToken->FakeRParens; i != e; ++i) {
1399     unsigned VariablePos = State.Stack.back().VariablePos;
1400     if (State.Stack.size() == 1) {
1401       // Do not pop the last element.
1402       break;
1403     }
1404     State.Stack.pop_back();
1405     State.Stack.back().VariablePos = VariablePos;
1406   }
1407 }
1408 
1409 void ContinuationIndenter::moveStatePastScopeOpener(LineState &State,
1410                                                     bool Newline) {
1411   const FormatToken &Current = *State.NextToken;
1412   if (!Current.opensScope())
1413     return;
1414 
1415   // Don't allow '<' or '(' in C# generic type constraints to start new scopes.
1416   if (Current.isOneOf(tok::less, tok::l_paren) &&
1417       State.Stack.back().IsCSharpGenericTypeConstraint)
1418     return;
1419 
1420   if (Current.MatchingParen && Current.BlockKind == BK_Block) {
1421     moveStateToNewBlock(State);
1422     return;
1423   }
1424 
1425   unsigned NewIndent;
1426   unsigned LastSpace = State.Stack.back().LastSpace;
1427   bool AvoidBinPacking;
1428   bool BreakBeforeParameter = false;
1429   unsigned NestedBlockIndent = std::max(State.Stack.back().StartOfFunctionCall,
1430                                         State.Stack.back().NestedBlockIndent);
1431   if (Current.isOneOf(tok::l_brace, TT_ArrayInitializerLSquare) ||
1432       opensProtoMessageField(Current, Style)) {
1433     if (Current.opensBlockOrBlockTypeList(Style)) {
1434       NewIndent = Style.IndentWidth +
1435                   std::min(State.Column, State.Stack.back().NestedBlockIndent);
1436     } else {
1437       NewIndent = State.Stack.back().LastSpace + Style.ContinuationIndentWidth;
1438     }
1439     const FormatToken *NextNoComment = Current.getNextNonComment();
1440     bool EndsInComma = Current.MatchingParen &&
1441                        Current.MatchingParen->Previous &&
1442                        Current.MatchingParen->Previous->is(tok::comma);
1443     AvoidBinPacking = EndsInComma || Current.is(TT_DictLiteral) ||
1444                       Style.Language == FormatStyle::LK_Proto ||
1445                       Style.Language == FormatStyle::LK_TextProto ||
1446                       !Style.BinPackArguments ||
1447                       (NextNoComment &&
1448                        NextNoComment->isOneOf(TT_DesignatedInitializerPeriod,
1449                                               TT_DesignatedInitializerLSquare));
1450     BreakBeforeParameter = EndsInComma;
1451     if (Current.ParameterCount > 1)
1452       NestedBlockIndent = std::max(NestedBlockIndent, State.Column + 1);
1453   } else {
1454     NewIndent = Style.ContinuationIndentWidth +
1455                 std::max(State.Stack.back().LastSpace,
1456                          State.Stack.back().StartOfFunctionCall);
1457 
1458     // Ensure that different different brackets force relative alignment, e.g.:
1459     // void SomeFunction(vector<  // break
1460     //                       int> v);
1461     // FIXME: We likely want to do this for more combinations of brackets.
1462     if (Current.is(tok::less) && Current.ParentBracket == tok::l_paren) {
1463       NewIndent = std::max(NewIndent, State.Stack.back().Indent);
1464       LastSpace = std::max(LastSpace, State.Stack.back().Indent);
1465     }
1466 
1467     bool EndsInComma =
1468         Current.MatchingParen &&
1469         Current.MatchingParen->getPreviousNonComment() &&
1470         Current.MatchingParen->getPreviousNonComment()->is(tok::comma);
1471 
1472     // If ObjCBinPackProtocolList is unspecified, fall back to BinPackParameters
1473     // for backwards compatibility.
1474     bool ObjCBinPackProtocolList =
1475         (Style.ObjCBinPackProtocolList == FormatStyle::BPS_Auto &&
1476          Style.BinPackParameters) ||
1477         Style.ObjCBinPackProtocolList == FormatStyle::BPS_Always;
1478 
1479     bool BinPackDeclaration =
1480         (State.Line->Type != LT_ObjCDecl && Style.BinPackParameters) ||
1481         (State.Line->Type == LT_ObjCDecl && ObjCBinPackProtocolList);
1482 
1483     AvoidBinPacking =
1484         (State.Stack.back().IsCSharpGenericTypeConstraint) ||
1485         (Style.Language == FormatStyle::LK_JavaScript && EndsInComma) ||
1486         (State.Line->MustBeDeclaration && !BinPackDeclaration) ||
1487         (!State.Line->MustBeDeclaration && !Style.BinPackArguments) ||
1488         (Style.ExperimentalAutoDetectBinPacking &&
1489          (Current.PackingKind == PPK_OnePerLine ||
1490           (!BinPackInconclusiveFunctions &&
1491            Current.PackingKind == PPK_Inconclusive)));
1492 
1493     if (Current.is(TT_ObjCMethodExpr) && Current.MatchingParen &&
1494         Style.ObjCBreakBeforeNestedBlockParam) {
1495       if (Style.ColumnLimit) {
1496         // If this '[' opens an ObjC call, determine whether all parameters fit
1497         // into one line and put one per line if they don't.
1498         if (getLengthToMatchingParen(Current, State.Stack) + State.Column >
1499             getColumnLimit(State))
1500           BreakBeforeParameter = true;
1501       } else {
1502         // For ColumnLimit = 0, we have to figure out whether there is or has to
1503         // be a line break within this call.
1504         for (const FormatToken *Tok = &Current;
1505              Tok && Tok != Current.MatchingParen; Tok = Tok->Next) {
1506           if (Tok->MustBreakBefore ||
1507               (Tok->CanBreakBefore && Tok->NewlinesBefore > 0)) {
1508             BreakBeforeParameter = true;
1509             break;
1510           }
1511         }
1512       }
1513     }
1514 
1515     if (Style.Language == FormatStyle::LK_JavaScript && EndsInComma)
1516       BreakBeforeParameter = true;
1517   }
1518   // Generally inherit NoLineBreak from the current scope to nested scope.
1519   // However, don't do this for non-empty nested blocks, dict literals and
1520   // array literals as these follow different indentation rules.
1521   bool NoLineBreak =
1522       Current.Children.empty() &&
1523       !Current.isOneOf(TT_DictLiteral, TT_ArrayInitializerLSquare) &&
1524       (State.Stack.back().NoLineBreak ||
1525        State.Stack.back().NoLineBreakInOperand ||
1526        (Current.is(TT_TemplateOpener) &&
1527         State.Stack.back().ContainsUnwrappedBuilder));
1528   State.Stack.push_back(
1529       ParenState(&Current, NewIndent, LastSpace, AvoidBinPacking, NoLineBreak));
1530   State.Stack.back().NestedBlockIndent = NestedBlockIndent;
1531   State.Stack.back().BreakBeforeParameter = BreakBeforeParameter;
1532   State.Stack.back().HasMultipleNestedBlocks =
1533       (Current.BlockParameterCount > 1);
1534 
1535   if (Style.BraceWrapping.BeforeLambdaBody && Current.Next != nullptr &&
1536       Current.Tok.is(tok::l_paren)) {
1537     // Search for any parameter that is a lambda
1538     FormatToken const *next = Current.Next;
1539     while (next != nullptr) {
1540       if (next->is(TT_LambdaLSquare)) {
1541         State.Stack.back().HasMultipleNestedBlocks = true;
1542         break;
1543       }
1544       next = next->Next;
1545     }
1546   }
1547 
1548   State.Stack.back().IsInsideObjCArrayLiteral =
1549       Current.is(TT_ArrayInitializerLSquare) && Current.Previous &&
1550       Current.Previous->is(tok::at);
1551 }
1552 
1553 void ContinuationIndenter::moveStatePastScopeCloser(LineState &State) {
1554   const FormatToken &Current = *State.NextToken;
1555   if (!Current.closesScope())
1556     return;
1557 
1558   // If we encounter a closing ), ], } or >, we can remove a level from our
1559   // stacks.
1560   if (State.Stack.size() > 1 &&
1561       (Current.isOneOf(tok::r_paren, tok::r_square, TT_TemplateString) ||
1562        (Current.is(tok::r_brace) && State.NextToken != State.Line->First) ||
1563        State.NextToken->is(TT_TemplateCloser) ||
1564        (Current.is(tok::greater) && Current.is(TT_DictLiteral))))
1565     State.Stack.pop_back();
1566 
1567   // Reevaluate whether ObjC message arguments fit into one line.
1568   // If a receiver spans multiple lines, e.g.:
1569   //   [[object block:^{
1570   //     return 42;
1571   //   }] a:42 b:42];
1572   // BreakBeforeParameter is calculated based on an incorrect assumption
1573   // (it is checked whether the whole expression fits into one line without
1574   // considering a line break inside a message receiver).
1575   // We check whether arguements fit after receiver scope closer (into the same
1576   // line).
1577   if (State.Stack.back().BreakBeforeParameter && Current.MatchingParen &&
1578       Current.MatchingParen->Previous) {
1579     const FormatToken &CurrentScopeOpener = *Current.MatchingParen->Previous;
1580     if (CurrentScopeOpener.is(TT_ObjCMethodExpr) &&
1581         CurrentScopeOpener.MatchingParen) {
1582       int NecessarySpaceInLine =
1583           getLengthToMatchingParen(CurrentScopeOpener, State.Stack) +
1584           CurrentScopeOpener.TotalLength - Current.TotalLength - 1;
1585       if (State.Column + Current.ColumnWidth + NecessarySpaceInLine <=
1586           Style.ColumnLimit)
1587         State.Stack.back().BreakBeforeParameter = false;
1588     }
1589   }
1590 
1591   if (Current.is(tok::r_square)) {
1592     // If this ends the array subscript expr, reset the corresponding value.
1593     const FormatToken *NextNonComment = Current.getNextNonComment();
1594     if (NextNonComment && NextNonComment->isNot(tok::l_square))
1595       State.Stack.back().StartOfArraySubscripts = 0;
1596   }
1597 }
1598 
1599 void ContinuationIndenter::moveStateToNewBlock(LineState &State) {
1600   unsigned NestedBlockIndent = State.Stack.back().NestedBlockIndent;
1601   // ObjC block sometimes follow special indentation rules.
1602   unsigned NewIndent =
1603       NestedBlockIndent + (State.NextToken->is(TT_ObjCBlockLBrace)
1604                                ? Style.ObjCBlockIndentWidth
1605                                : Style.IndentWidth);
1606   State.Stack.push_back(ParenState(State.NextToken, NewIndent,
1607                                    State.Stack.back().LastSpace,
1608                                    /*AvoidBinPacking=*/true,
1609                                    /*NoLineBreak=*/false));
1610   State.Stack.back().NestedBlockIndent = NestedBlockIndent;
1611   State.Stack.back().BreakBeforeParameter = true;
1612 }
1613 
1614 static unsigned getLastLineEndColumn(StringRef Text, unsigned StartColumn,
1615                                      unsigned TabWidth,
1616                                      encoding::Encoding Encoding) {
1617   size_t LastNewlinePos = Text.find_last_of("\n");
1618   if (LastNewlinePos == StringRef::npos) {
1619     return StartColumn +
1620            encoding::columnWidthWithTabs(Text, StartColumn, TabWidth, Encoding);
1621   } else {
1622     return encoding::columnWidthWithTabs(Text.substr(LastNewlinePos),
1623                                          /*StartColumn=*/0, TabWidth, Encoding);
1624   }
1625 }
1626 
1627 unsigned ContinuationIndenter::reformatRawStringLiteral(
1628     const FormatToken &Current, LineState &State,
1629     const FormatStyle &RawStringStyle, bool DryRun, bool Newline) {
1630   unsigned StartColumn = State.Column - Current.ColumnWidth;
1631   StringRef OldDelimiter = *getRawStringDelimiter(Current.TokenText);
1632   StringRef NewDelimiter =
1633       getCanonicalRawStringDelimiter(Style, RawStringStyle.Language);
1634   if (NewDelimiter.empty() || OldDelimiter.empty())
1635     NewDelimiter = OldDelimiter;
1636   // The text of a raw string is between the leading 'R"delimiter(' and the
1637   // trailing 'delimiter)"'.
1638   unsigned OldPrefixSize = 3 + OldDelimiter.size();
1639   unsigned OldSuffixSize = 2 + OldDelimiter.size();
1640   // We create a virtual text environment which expects a null-terminated
1641   // string, so we cannot use StringRef.
1642   std::string RawText = std::string(
1643       Current.TokenText.substr(OldPrefixSize).drop_back(OldSuffixSize));
1644   if (NewDelimiter != OldDelimiter) {
1645     // Don't update to the canonical delimiter 'deli' if ')deli"' occurs in the
1646     // raw string.
1647     std::string CanonicalDelimiterSuffix = (")" + NewDelimiter + "\"").str();
1648     if (StringRef(RawText).contains(CanonicalDelimiterSuffix))
1649       NewDelimiter = OldDelimiter;
1650   }
1651 
1652   unsigned NewPrefixSize = 3 + NewDelimiter.size();
1653   unsigned NewSuffixSize = 2 + NewDelimiter.size();
1654 
1655   // The first start column is the column the raw text starts after formatting.
1656   unsigned FirstStartColumn = StartColumn + NewPrefixSize;
1657 
1658   // The next start column is the intended indentation a line break inside
1659   // the raw string at level 0. It is determined by the following rules:
1660   //   - if the content starts on newline, it is one level more than the current
1661   //     indent, and
1662   //   - if the content does not start on a newline, it is the first start
1663   //     column.
1664   // These rules have the advantage that the formatted content both does not
1665   // violate the rectangle rule and visually flows within the surrounding
1666   // source.
1667   bool ContentStartsOnNewline = Current.TokenText[OldPrefixSize] == '\n';
1668   // If this token is the last parameter (checked by looking if it's followed by
1669   // `)` and is not on a newline, the base the indent off the line's nested
1670   // block indent. Otherwise, base the indent off the arguments indent, so we
1671   // can achieve:
1672   //
1673   // fffffffffff(1, 2, 3, R"pb(
1674   //     key1: 1  #
1675   //     key2: 2)pb");
1676   //
1677   // fffffffffff(1, 2, 3,
1678   //             R"pb(
1679   //               key1: 1  #
1680   //               key2: 2
1681   //             )pb");
1682   //
1683   // fffffffffff(1, 2, 3,
1684   //             R"pb(
1685   //               key1: 1  #
1686   //               key2: 2
1687   //             )pb",
1688   //             5);
1689   unsigned CurrentIndent =
1690       (!Newline && Current.Next && Current.Next->is(tok::r_paren))
1691           ? State.Stack.back().NestedBlockIndent
1692           : State.Stack.back().Indent;
1693   unsigned NextStartColumn = ContentStartsOnNewline
1694                                  ? CurrentIndent + Style.IndentWidth
1695                                  : FirstStartColumn;
1696 
1697   // The last start column is the column the raw string suffix starts if it is
1698   // put on a newline.
1699   // The last start column is the intended indentation of the raw string postfix
1700   // if it is put on a newline. It is determined by the following rules:
1701   //   - if the raw string prefix starts on a newline, it is the column where
1702   //     that raw string prefix starts, and
1703   //   - if the raw string prefix does not start on a newline, it is the current
1704   //     indent.
1705   unsigned LastStartColumn =
1706       Current.NewlinesBefore ? FirstStartColumn - NewPrefixSize : CurrentIndent;
1707 
1708   std::pair<tooling::Replacements, unsigned> Fixes = internal::reformat(
1709       RawStringStyle, RawText, {tooling::Range(0, RawText.size())},
1710       FirstStartColumn, NextStartColumn, LastStartColumn, "<stdin>",
1711       /*Status=*/nullptr);
1712 
1713   auto NewCode = applyAllReplacements(RawText, Fixes.first);
1714   tooling::Replacements NoFixes;
1715   if (!NewCode) {
1716     return addMultilineToken(Current, State);
1717   }
1718   if (!DryRun) {
1719     if (NewDelimiter != OldDelimiter) {
1720       // In 'R"delimiter(...', the delimiter starts 2 characters after the start
1721       // of the token.
1722       SourceLocation PrefixDelimiterStart =
1723           Current.Tok.getLocation().getLocWithOffset(2);
1724       auto PrefixErr = Whitespaces.addReplacement(tooling::Replacement(
1725           SourceMgr, PrefixDelimiterStart, OldDelimiter.size(), NewDelimiter));
1726       if (PrefixErr) {
1727         llvm::errs()
1728             << "Failed to update the prefix delimiter of a raw string: "
1729             << llvm::toString(std::move(PrefixErr)) << "\n";
1730       }
1731       // In 'R"delimiter(...)delimiter"', the suffix delimiter starts at
1732       // position length - 1 - |delimiter|.
1733       SourceLocation SuffixDelimiterStart =
1734           Current.Tok.getLocation().getLocWithOffset(Current.TokenText.size() -
1735                                                      1 - OldDelimiter.size());
1736       auto SuffixErr = Whitespaces.addReplacement(tooling::Replacement(
1737           SourceMgr, SuffixDelimiterStart, OldDelimiter.size(), NewDelimiter));
1738       if (SuffixErr) {
1739         llvm::errs()
1740             << "Failed to update the suffix delimiter of a raw string: "
1741             << llvm::toString(std::move(SuffixErr)) << "\n";
1742       }
1743     }
1744     SourceLocation OriginLoc =
1745         Current.Tok.getLocation().getLocWithOffset(OldPrefixSize);
1746     for (const tooling::Replacement &Fix : Fixes.first) {
1747       auto Err = Whitespaces.addReplacement(tooling::Replacement(
1748           SourceMgr, OriginLoc.getLocWithOffset(Fix.getOffset()),
1749           Fix.getLength(), Fix.getReplacementText()));
1750       if (Err) {
1751         llvm::errs() << "Failed to reformat raw string: "
1752                      << llvm::toString(std::move(Err)) << "\n";
1753       }
1754     }
1755   }
1756   unsigned RawLastLineEndColumn = getLastLineEndColumn(
1757       *NewCode, FirstStartColumn, Style.TabWidth, Encoding);
1758   State.Column = RawLastLineEndColumn + NewSuffixSize;
1759   // Since we're updating the column to after the raw string literal here, we
1760   // have to manually add the penalty for the prefix R"delim( over the column
1761   // limit.
1762   unsigned PrefixExcessCharacters =
1763       StartColumn + NewPrefixSize > Style.ColumnLimit
1764           ? StartColumn + NewPrefixSize - Style.ColumnLimit
1765           : 0;
1766   bool IsMultiline =
1767       ContentStartsOnNewline || (NewCode->find('\n') != std::string::npos);
1768   if (IsMultiline) {
1769     // Break before further function parameters on all levels.
1770     for (unsigned i = 0, e = State.Stack.size(); i != e; ++i)
1771       State.Stack[i].BreakBeforeParameter = true;
1772   }
1773   return Fixes.second + PrefixExcessCharacters * Style.PenaltyExcessCharacter;
1774 }
1775 
1776 unsigned ContinuationIndenter::addMultilineToken(const FormatToken &Current,
1777                                                  LineState &State) {
1778   // Break before further function parameters on all levels.
1779   for (unsigned i = 0, e = State.Stack.size(); i != e; ++i)
1780     State.Stack[i].BreakBeforeParameter = true;
1781 
1782   unsigned ColumnsUsed = State.Column;
1783   // We can only affect layout of the first and the last line, so the penalty
1784   // for all other lines is constant, and we ignore it.
1785   State.Column = Current.LastLineColumnWidth;
1786 
1787   if (ColumnsUsed > getColumnLimit(State))
1788     return Style.PenaltyExcessCharacter * (ColumnsUsed - getColumnLimit(State));
1789   return 0;
1790 }
1791 
1792 unsigned ContinuationIndenter::handleEndOfLine(const FormatToken &Current,
1793                                                LineState &State, bool DryRun,
1794                                                bool AllowBreak, bool Newline) {
1795   unsigned Penalty = 0;
1796   // Compute the raw string style to use in case this is a raw string literal
1797   // that can be reformatted.
1798   auto RawStringStyle = getRawStringStyle(Current, State);
1799   if (RawStringStyle && !Current.Finalized) {
1800     Penalty = reformatRawStringLiteral(Current, State, *RawStringStyle, DryRun,
1801                                        Newline);
1802   } else if (Current.IsMultiline && Current.isNot(TT_BlockComment)) {
1803     // Don't break multi-line tokens other than block comments and raw string
1804     // literals. Instead, just update the state.
1805     Penalty = addMultilineToken(Current, State);
1806   } else if (State.Line->Type != LT_ImportStatement) {
1807     // We generally don't break import statements.
1808     LineState OriginalState = State;
1809 
1810     // Whether we force the reflowing algorithm to stay strictly within the
1811     // column limit.
1812     bool Strict = false;
1813     // Whether the first non-strict attempt at reflowing did intentionally
1814     // exceed the column limit.
1815     bool Exceeded = false;
1816     std::tie(Penalty, Exceeded) = breakProtrudingToken(
1817         Current, State, AllowBreak, /*DryRun=*/true, Strict);
1818     if (Exceeded) {
1819       // If non-strict reflowing exceeds the column limit, try whether strict
1820       // reflowing leads to an overall lower penalty.
1821       LineState StrictState = OriginalState;
1822       unsigned StrictPenalty =
1823           breakProtrudingToken(Current, StrictState, AllowBreak,
1824                                /*DryRun=*/true, /*Strict=*/true)
1825               .first;
1826       Strict = StrictPenalty <= Penalty;
1827       if (Strict) {
1828         Penalty = StrictPenalty;
1829         State = StrictState;
1830       }
1831     }
1832     if (!DryRun) {
1833       // If we're not in dry-run mode, apply the changes with the decision on
1834       // strictness made above.
1835       breakProtrudingToken(Current, OriginalState, AllowBreak, /*DryRun=*/false,
1836                            Strict);
1837     }
1838   }
1839   if (State.Column > getColumnLimit(State)) {
1840     unsigned ExcessCharacters = State.Column - getColumnLimit(State);
1841     Penalty += Style.PenaltyExcessCharacter * ExcessCharacters;
1842   }
1843   return Penalty;
1844 }
1845 
1846 // Returns the enclosing function name of a token, or the empty string if not
1847 // found.
1848 static StringRef getEnclosingFunctionName(const FormatToken &Current) {
1849   // Look for: 'function(' or 'function<templates>(' before Current.
1850   auto Tok = Current.getPreviousNonComment();
1851   if (!Tok || !Tok->is(tok::l_paren))
1852     return "";
1853   Tok = Tok->getPreviousNonComment();
1854   if (!Tok)
1855     return "";
1856   if (Tok->is(TT_TemplateCloser)) {
1857     Tok = Tok->MatchingParen;
1858     if (Tok)
1859       Tok = Tok->getPreviousNonComment();
1860   }
1861   if (!Tok || !Tok->is(tok::identifier))
1862     return "";
1863   return Tok->TokenText;
1864 }
1865 
1866 llvm::Optional<FormatStyle>
1867 ContinuationIndenter::getRawStringStyle(const FormatToken &Current,
1868                                         const LineState &State) {
1869   if (!Current.isStringLiteral())
1870     return None;
1871   auto Delimiter = getRawStringDelimiter(Current.TokenText);
1872   if (!Delimiter)
1873     return None;
1874   auto RawStringStyle = RawStringFormats.getDelimiterStyle(*Delimiter);
1875   if (!RawStringStyle && Delimiter->empty())
1876     RawStringStyle = RawStringFormats.getEnclosingFunctionStyle(
1877         getEnclosingFunctionName(Current));
1878   if (!RawStringStyle)
1879     return None;
1880   RawStringStyle->ColumnLimit = getColumnLimit(State);
1881   return RawStringStyle;
1882 }
1883 
1884 std::unique_ptr<BreakableToken>
1885 ContinuationIndenter::createBreakableToken(const FormatToken &Current,
1886                                            LineState &State, bool AllowBreak) {
1887   unsigned StartColumn = State.Column - Current.ColumnWidth;
1888   if (Current.isStringLiteral()) {
1889     // FIXME: String literal breaking is currently disabled for C#, Java and
1890     // JavaScript, as it requires strings to be merged using "+" which we
1891     // don't support.
1892     if (Style.Language == FormatStyle::LK_Java ||
1893         Style.Language == FormatStyle::LK_JavaScript || Style.isCSharp() ||
1894         !Style.BreakStringLiterals || !AllowBreak)
1895       return nullptr;
1896 
1897     // Don't break string literals inside preprocessor directives (except for
1898     // #define directives, as their contents are stored in separate lines and
1899     // are not affected by this check).
1900     // This way we avoid breaking code with line directives and unknown
1901     // preprocessor directives that contain long string literals.
1902     if (State.Line->Type == LT_PreprocessorDirective)
1903       return nullptr;
1904     // Exempts unterminated string literals from line breaking. The user will
1905     // likely want to terminate the string before any line breaking is done.
1906     if (Current.IsUnterminatedLiteral)
1907       return nullptr;
1908     // Don't break string literals inside Objective-C array literals (doing so
1909     // raises the warning -Wobjc-string-concatenation).
1910     if (State.Stack.back().IsInsideObjCArrayLiteral) {
1911       return nullptr;
1912     }
1913 
1914     StringRef Text = Current.TokenText;
1915     StringRef Prefix;
1916     StringRef Postfix;
1917     // FIXME: Handle whitespace between '_T', '(', '"..."', and ')'.
1918     // FIXME: Store Prefix and Suffix (or PrefixLength and SuffixLength to
1919     // reduce the overhead) for each FormatToken, which is a string, so that we
1920     // don't run multiple checks here on the hot path.
1921     if ((Text.endswith(Postfix = "\"") &&
1922          (Text.startswith(Prefix = "@\"") || Text.startswith(Prefix = "\"") ||
1923           Text.startswith(Prefix = "u\"") || Text.startswith(Prefix = "U\"") ||
1924           Text.startswith(Prefix = "u8\"") ||
1925           Text.startswith(Prefix = "L\""))) ||
1926         (Text.startswith(Prefix = "_T(\"") && Text.endswith(Postfix = "\")"))) {
1927       // We need this to address the case where there is an unbreakable tail
1928       // only if certain other formatting decisions have been taken. The
1929       // UnbreakableTailLength of Current is an overapproximation is that case
1930       // and we need to be correct here.
1931       unsigned UnbreakableTailLength = (State.NextToken && canBreak(State))
1932                                            ? 0
1933                                            : Current.UnbreakableTailLength;
1934       return std::make_unique<BreakableStringLiteral>(
1935           Current, StartColumn, Prefix, Postfix, UnbreakableTailLength,
1936           State.Line->InPPDirective, Encoding, Style);
1937     }
1938   } else if (Current.is(TT_BlockComment)) {
1939     if (!Style.ReflowComments ||
1940         // If a comment token switches formatting, like
1941         // /* clang-format on */, we don't want to break it further,
1942         // but we may still want to adjust its indentation.
1943         switchesFormatting(Current)) {
1944       return nullptr;
1945     }
1946     return std::make_unique<BreakableBlockComment>(
1947         Current, StartColumn, Current.OriginalColumn, !Current.Previous,
1948         State.Line->InPPDirective, Encoding, Style, Whitespaces.useCRLF());
1949   } else if (Current.is(TT_LineComment) &&
1950              (Current.Previous == nullptr ||
1951               Current.Previous->isNot(TT_ImplicitStringLiteral))) {
1952     if (!Style.ReflowComments ||
1953         CommentPragmasRegex.match(Current.TokenText.substr(2)) ||
1954         switchesFormatting(Current))
1955       return nullptr;
1956     return std::make_unique<BreakableLineCommentSection>(
1957         Current, StartColumn, Current.OriginalColumn, !Current.Previous,
1958         /*InPPDirective=*/false, Encoding, Style);
1959   }
1960   return nullptr;
1961 }
1962 
1963 std::pair<unsigned, bool>
1964 ContinuationIndenter::breakProtrudingToken(const FormatToken &Current,
1965                                            LineState &State, bool AllowBreak,
1966                                            bool DryRun, bool Strict) {
1967   std::unique_ptr<const BreakableToken> Token =
1968       createBreakableToken(Current, State, AllowBreak);
1969   if (!Token)
1970     return {0, false};
1971   assert(Token->getLineCount() > 0);
1972   unsigned ColumnLimit = getColumnLimit(State);
1973   if (Current.is(TT_LineComment)) {
1974     // We don't insert backslashes when breaking line comments.
1975     ColumnLimit = Style.ColumnLimit;
1976   }
1977   if (Current.UnbreakableTailLength >= ColumnLimit)
1978     return {0, false};
1979   // ColumnWidth was already accounted into State.Column before calling
1980   // breakProtrudingToken.
1981   unsigned StartColumn = State.Column - Current.ColumnWidth;
1982   unsigned NewBreakPenalty = Current.isStringLiteral()
1983                                  ? Style.PenaltyBreakString
1984                                  : Style.PenaltyBreakComment;
1985   // Stores whether we intentionally decide to let a line exceed the column
1986   // limit.
1987   bool Exceeded = false;
1988   // Stores whether we introduce a break anywhere in the token.
1989   bool BreakInserted = Token->introducesBreakBeforeToken();
1990   // Store whether we inserted a new line break at the end of the previous
1991   // logical line.
1992   bool NewBreakBefore = false;
1993   // We use a conservative reflowing strategy. Reflow starts after a line is
1994   // broken or the corresponding whitespace compressed. Reflow ends as soon as a
1995   // line that doesn't get reflown with the previous line is reached.
1996   bool Reflow = false;
1997   // Keep track of where we are in the token:
1998   // Where we are in the content of the current logical line.
1999   unsigned TailOffset = 0;
2000   // The column number we're currently at.
2001   unsigned ContentStartColumn =
2002       Token->getContentStartColumn(0, /*Break=*/false);
2003   // The number of columns left in the current logical line after TailOffset.
2004   unsigned RemainingTokenColumns =
2005       Token->getRemainingLength(0, TailOffset, ContentStartColumn);
2006   // Adapt the start of the token, for example indent.
2007   if (!DryRun)
2008     Token->adaptStartOfLine(0, Whitespaces);
2009 
2010   unsigned ContentIndent = 0;
2011   unsigned Penalty = 0;
2012   LLVM_DEBUG(llvm::dbgs() << "Breaking protruding token at column "
2013                           << StartColumn << ".\n");
2014   for (unsigned LineIndex = 0, EndIndex = Token->getLineCount();
2015        LineIndex != EndIndex; ++LineIndex) {
2016     LLVM_DEBUG(llvm::dbgs()
2017                << "  Line: " << LineIndex << " (Reflow: " << Reflow << ")\n");
2018     NewBreakBefore = false;
2019     // If we did reflow the previous line, we'll try reflowing again. Otherwise
2020     // we'll start reflowing if the current line is broken or whitespace is
2021     // compressed.
2022     bool TryReflow = Reflow;
2023     // Break the current token until we can fit the rest of the line.
2024     while (ContentStartColumn + RemainingTokenColumns > ColumnLimit) {
2025       LLVM_DEBUG(llvm::dbgs() << "    Over limit, need: "
2026                               << (ContentStartColumn + RemainingTokenColumns)
2027                               << ", space: " << ColumnLimit
2028                               << ", reflown prefix: " << ContentStartColumn
2029                               << ", offset in line: " << TailOffset << "\n");
2030       // If the current token doesn't fit, find the latest possible split in the
2031       // current line so that breaking at it will be under the column limit.
2032       // FIXME: Use the earliest possible split while reflowing to correctly
2033       // compress whitespace within a line.
2034       BreakableToken::Split Split =
2035           Token->getSplit(LineIndex, TailOffset, ColumnLimit,
2036                           ContentStartColumn, CommentPragmasRegex);
2037       if (Split.first == StringRef::npos) {
2038         // No break opportunity - update the penalty and continue with the next
2039         // logical line.
2040         if (LineIndex < EndIndex - 1)
2041           // The last line's penalty is handled in addNextStateToQueue() or when
2042           // calling replaceWhitespaceAfterLastLine below.
2043           Penalty += Style.PenaltyExcessCharacter *
2044                      (ContentStartColumn + RemainingTokenColumns - ColumnLimit);
2045         LLVM_DEBUG(llvm::dbgs() << "    No break opportunity.\n");
2046         break;
2047       }
2048       assert(Split.first != 0);
2049 
2050       if (Token->supportsReflow()) {
2051         // Check whether the next natural split point after the current one can
2052         // still fit the line, either because we can compress away whitespace,
2053         // or because the penalty the excess characters introduce is lower than
2054         // the break penalty.
2055         // We only do this for tokens that support reflowing, and thus allow us
2056         // to change the whitespace arbitrarily (e.g. comments).
2057         // Other tokens, like string literals, can be broken on arbitrary
2058         // positions.
2059 
2060         // First, compute the columns from TailOffset to the next possible split
2061         // position.
2062         // For example:
2063         // ColumnLimit:     |
2064         // // Some text   that    breaks
2065         //    ^ tail offset
2066         //             ^-- split
2067         //    ^-------- to split columns
2068         //                    ^--- next split
2069         //    ^--------------- to next split columns
2070         unsigned ToSplitColumns = Token->getRangeLength(
2071             LineIndex, TailOffset, Split.first, ContentStartColumn);
2072         LLVM_DEBUG(llvm::dbgs() << "    ToSplit: " << ToSplitColumns << "\n");
2073 
2074         BreakableToken::Split NextSplit = Token->getSplit(
2075             LineIndex, TailOffset + Split.first + Split.second, ColumnLimit,
2076             ContentStartColumn + ToSplitColumns + 1, CommentPragmasRegex);
2077         // Compute the columns necessary to fit the next non-breakable sequence
2078         // into the current line.
2079         unsigned ToNextSplitColumns = 0;
2080         if (NextSplit.first == StringRef::npos) {
2081           ToNextSplitColumns = Token->getRemainingLength(LineIndex, TailOffset,
2082                                                          ContentStartColumn);
2083         } else {
2084           ToNextSplitColumns = Token->getRangeLength(
2085               LineIndex, TailOffset,
2086               Split.first + Split.second + NextSplit.first, ContentStartColumn);
2087         }
2088         // Compress the whitespace between the break and the start of the next
2089         // unbreakable sequence.
2090         ToNextSplitColumns =
2091             Token->getLengthAfterCompression(ToNextSplitColumns, Split);
2092         LLVM_DEBUG(llvm::dbgs()
2093                    << "    ContentStartColumn: " << ContentStartColumn << "\n");
2094         LLVM_DEBUG(llvm::dbgs()
2095                    << "    ToNextSplit: " << ToNextSplitColumns << "\n");
2096         // If the whitespace compression makes us fit, continue on the current
2097         // line.
2098         bool ContinueOnLine =
2099             ContentStartColumn + ToNextSplitColumns <= ColumnLimit;
2100         unsigned ExcessCharactersPenalty = 0;
2101         if (!ContinueOnLine && !Strict) {
2102           // Similarly, if the excess characters' penalty is lower than the
2103           // penalty of introducing a new break, continue on the current line.
2104           ExcessCharactersPenalty =
2105               (ContentStartColumn + ToNextSplitColumns - ColumnLimit) *
2106               Style.PenaltyExcessCharacter;
2107           LLVM_DEBUG(llvm::dbgs()
2108                      << "    Penalty excess: " << ExcessCharactersPenalty
2109                      << "\n            break : " << NewBreakPenalty << "\n");
2110           if (ExcessCharactersPenalty < NewBreakPenalty) {
2111             Exceeded = true;
2112             ContinueOnLine = true;
2113           }
2114         }
2115         if (ContinueOnLine) {
2116           LLVM_DEBUG(llvm::dbgs() << "    Continuing on line...\n");
2117           // The current line fits after compressing the whitespace - reflow
2118           // the next line into it if possible.
2119           TryReflow = true;
2120           if (!DryRun)
2121             Token->compressWhitespace(LineIndex, TailOffset, Split,
2122                                       Whitespaces);
2123           // When we continue on the same line, leave one space between content.
2124           ContentStartColumn += ToSplitColumns + 1;
2125           Penalty += ExcessCharactersPenalty;
2126           TailOffset += Split.first + Split.second;
2127           RemainingTokenColumns = Token->getRemainingLength(
2128               LineIndex, TailOffset, ContentStartColumn);
2129           continue;
2130         }
2131       }
2132       LLVM_DEBUG(llvm::dbgs() << "    Breaking...\n");
2133       // Update the ContentIndent only if the current line was not reflown with
2134       // the previous line, since in that case the previous line should still
2135       // determine the ContentIndent. Also never intent the last line.
2136       if (!Reflow)
2137         ContentIndent = Token->getContentIndent(LineIndex);
2138       LLVM_DEBUG(llvm::dbgs()
2139                  << "    ContentIndent: " << ContentIndent << "\n");
2140       ContentStartColumn = ContentIndent + Token->getContentStartColumn(
2141                                                LineIndex, /*Break=*/true);
2142 
2143       unsigned NewRemainingTokenColumns = Token->getRemainingLength(
2144           LineIndex, TailOffset + Split.first + Split.second,
2145           ContentStartColumn);
2146       if (NewRemainingTokenColumns == 0) {
2147         // No content to indent.
2148         ContentIndent = 0;
2149         ContentStartColumn =
2150             Token->getContentStartColumn(LineIndex, /*Break=*/true);
2151         NewRemainingTokenColumns = Token->getRemainingLength(
2152             LineIndex, TailOffset + Split.first + Split.second,
2153             ContentStartColumn);
2154       }
2155 
2156       // When breaking before a tab character, it may be moved by a few columns,
2157       // but will still be expanded to the next tab stop, so we don't save any
2158       // columns.
2159       if (NewRemainingTokenColumns == RemainingTokenColumns) {
2160         // FIXME: Do we need to adjust the penalty?
2161         break;
2162       }
2163       assert(NewRemainingTokenColumns < RemainingTokenColumns);
2164 
2165       LLVM_DEBUG(llvm::dbgs() << "    Breaking at: " << TailOffset + Split.first
2166                               << ", " << Split.second << "\n");
2167       if (!DryRun)
2168         Token->insertBreak(LineIndex, TailOffset, Split, ContentIndent,
2169                            Whitespaces);
2170 
2171       Penalty += NewBreakPenalty;
2172       TailOffset += Split.first + Split.second;
2173       RemainingTokenColumns = NewRemainingTokenColumns;
2174       BreakInserted = true;
2175       NewBreakBefore = true;
2176     }
2177     // In case there's another line, prepare the state for the start of the next
2178     // line.
2179     if (LineIndex + 1 != EndIndex) {
2180       unsigned NextLineIndex = LineIndex + 1;
2181       if (NewBreakBefore)
2182         // After breaking a line, try to reflow the next line into the current
2183         // one once RemainingTokenColumns fits.
2184         TryReflow = true;
2185       if (TryReflow) {
2186         // We decided that we want to try reflowing the next line into the
2187         // current one.
2188         // We will now adjust the state as if the reflow is successful (in
2189         // preparation for the next line), and see whether that works. If we
2190         // decide that we cannot reflow, we will later reset the state to the
2191         // start of the next line.
2192         Reflow = false;
2193         // As we did not continue breaking the line, RemainingTokenColumns is
2194         // known to fit after ContentStartColumn. Adapt ContentStartColumn to
2195         // the position at which we want to format the next line if we do
2196         // actually reflow.
2197         // When we reflow, we need to add a space between the end of the current
2198         // line and the next line's start column.
2199         ContentStartColumn += RemainingTokenColumns + 1;
2200         // Get the split that we need to reflow next logical line into the end
2201         // of the current one; the split will include any leading whitespace of
2202         // the next logical line.
2203         BreakableToken::Split SplitBeforeNext =
2204             Token->getReflowSplit(NextLineIndex, CommentPragmasRegex);
2205         LLVM_DEBUG(llvm::dbgs()
2206                    << "    Size of reflown text: " << ContentStartColumn
2207                    << "\n    Potential reflow split: ");
2208         if (SplitBeforeNext.first != StringRef::npos) {
2209           LLVM_DEBUG(llvm::dbgs() << SplitBeforeNext.first << ", "
2210                                   << SplitBeforeNext.second << "\n");
2211           TailOffset = SplitBeforeNext.first + SplitBeforeNext.second;
2212           // If the rest of the next line fits into the current line below the
2213           // column limit, we can safely reflow.
2214           RemainingTokenColumns = Token->getRemainingLength(
2215               NextLineIndex, TailOffset, ContentStartColumn);
2216           Reflow = true;
2217           if (ContentStartColumn + RemainingTokenColumns > ColumnLimit) {
2218             LLVM_DEBUG(llvm::dbgs()
2219                        << "    Over limit after reflow, need: "
2220                        << (ContentStartColumn + RemainingTokenColumns)
2221                        << ", space: " << ColumnLimit
2222                        << ", reflown prefix: " << ContentStartColumn
2223                        << ", offset in line: " << TailOffset << "\n");
2224             // If the whole next line does not fit, try to find a point in
2225             // the next line at which we can break so that attaching the part
2226             // of the next line to that break point onto the current line is
2227             // below the column limit.
2228             BreakableToken::Split Split =
2229                 Token->getSplit(NextLineIndex, TailOffset, ColumnLimit,
2230                                 ContentStartColumn, CommentPragmasRegex);
2231             if (Split.first == StringRef::npos) {
2232               LLVM_DEBUG(llvm::dbgs() << "    Did not find later break\n");
2233               Reflow = false;
2234             } else {
2235               // Check whether the first split point gets us below the column
2236               // limit. Note that we will execute this split below as part of
2237               // the normal token breaking and reflow logic within the line.
2238               unsigned ToSplitColumns = Token->getRangeLength(
2239                   NextLineIndex, TailOffset, Split.first, ContentStartColumn);
2240               if (ContentStartColumn + ToSplitColumns > ColumnLimit) {
2241                 LLVM_DEBUG(llvm::dbgs() << "    Next split protrudes, need: "
2242                                         << (ContentStartColumn + ToSplitColumns)
2243                                         << ", space: " << ColumnLimit);
2244                 unsigned ExcessCharactersPenalty =
2245                     (ContentStartColumn + ToSplitColumns - ColumnLimit) *
2246                     Style.PenaltyExcessCharacter;
2247                 if (NewBreakPenalty < ExcessCharactersPenalty) {
2248                   Reflow = false;
2249                 }
2250               }
2251             }
2252           }
2253         } else {
2254           LLVM_DEBUG(llvm::dbgs() << "not found.\n");
2255         }
2256       }
2257       if (!Reflow) {
2258         // If we didn't reflow into the next line, the only space to consider is
2259         // the next logical line. Reset our state to match the start of the next
2260         // line.
2261         TailOffset = 0;
2262         ContentStartColumn =
2263             Token->getContentStartColumn(NextLineIndex, /*Break=*/false);
2264         RemainingTokenColumns = Token->getRemainingLength(
2265             NextLineIndex, TailOffset, ContentStartColumn);
2266         // Adapt the start of the token, for example indent.
2267         if (!DryRun)
2268           Token->adaptStartOfLine(NextLineIndex, Whitespaces);
2269       } else {
2270         // If we found a reflow split and have added a new break before the next
2271         // line, we are going to remove the line break at the start of the next
2272         // logical line. For example, here we'll add a new line break after
2273         // 'text', and subsequently delete the line break between 'that' and
2274         // 'reflows'.
2275         //   // some text that
2276         //   // reflows
2277         // ->
2278         //   // some text
2279         //   // that reflows
2280         // When adding the line break, we also added the penalty for it, so we
2281         // need to subtract that penalty again when we remove the line break due
2282         // to reflowing.
2283         if (NewBreakBefore) {
2284           assert(Penalty >= NewBreakPenalty);
2285           Penalty -= NewBreakPenalty;
2286         }
2287         if (!DryRun)
2288           Token->reflow(NextLineIndex, Whitespaces);
2289       }
2290     }
2291   }
2292 
2293   BreakableToken::Split SplitAfterLastLine =
2294       Token->getSplitAfterLastLine(TailOffset);
2295   if (SplitAfterLastLine.first != StringRef::npos) {
2296     LLVM_DEBUG(llvm::dbgs() << "Replacing whitespace after last line.\n");
2297 
2298     // We add the last line's penalty here, since that line is going to be split
2299     // now.
2300     Penalty += Style.PenaltyExcessCharacter *
2301                (ContentStartColumn + RemainingTokenColumns - ColumnLimit);
2302 
2303     if (!DryRun)
2304       Token->replaceWhitespaceAfterLastLine(TailOffset, SplitAfterLastLine,
2305                                             Whitespaces);
2306     ContentStartColumn =
2307         Token->getContentStartColumn(Token->getLineCount() - 1, /*Break=*/true);
2308     RemainingTokenColumns = Token->getRemainingLength(
2309         Token->getLineCount() - 1,
2310         TailOffset + SplitAfterLastLine.first + SplitAfterLastLine.second,
2311         ContentStartColumn);
2312   }
2313 
2314   State.Column = ContentStartColumn + RemainingTokenColumns -
2315                  Current.UnbreakableTailLength;
2316 
2317   if (BreakInserted) {
2318     // If we break the token inside a parameter list, we need to break before
2319     // the next parameter on all levels, so that the next parameter is clearly
2320     // visible. Line comments already introduce a break.
2321     if (Current.isNot(TT_LineComment)) {
2322       for (unsigned i = 0, e = State.Stack.size(); i != e; ++i)
2323         State.Stack[i].BreakBeforeParameter = true;
2324     }
2325 
2326     if (Current.is(TT_BlockComment))
2327       State.NoContinuation = true;
2328 
2329     State.Stack.back().LastSpace = StartColumn;
2330   }
2331 
2332   Token->updateNextToken(State);
2333 
2334   return {Penalty, Exceeded};
2335 }
2336 
2337 unsigned ContinuationIndenter::getColumnLimit(const LineState &State) const {
2338   // In preprocessor directives reserve two chars for trailing " \"
2339   return Style.ColumnLimit - (State.Line->InPPDirective ? 2 : 0);
2340 }
2341 
2342 bool ContinuationIndenter::nextIsMultilineString(const LineState &State) {
2343   const FormatToken &Current = *State.NextToken;
2344   if (!Current.isStringLiteral() || Current.is(TT_ImplicitStringLiteral))
2345     return false;
2346   // We never consider raw string literals "multiline" for the purpose of
2347   // AlwaysBreakBeforeMultilineStrings implementation as they are special-cased
2348   // (see TokenAnnotator::mustBreakBefore().
2349   if (Current.TokenText.startswith("R\""))
2350     return false;
2351   if (Current.IsMultiline)
2352     return true;
2353   if (Current.getNextNonComment() &&
2354       Current.getNextNonComment()->isStringLiteral())
2355     return true; // Implicit concatenation.
2356   if (Style.ColumnLimit != 0 && Style.BreakStringLiterals &&
2357       State.Column + Current.ColumnWidth + Current.UnbreakableTailLength >
2358           Style.ColumnLimit)
2359     return true; // String will be split.
2360   return false;
2361 }
2362 
2363 } // namespace format
2364 } // namespace clang
2365