1 //===--- TokenAnnotator.cpp - Format C++ code -----------------------------===//
2 //
3 //                     The LLVM Compiler Infrastructure
4 //
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
7 //
8 //===----------------------------------------------------------------------===//
9 ///
10 /// \file
11 /// \brief This file implements a token annotator, i.e. creates
12 /// \c AnnotatedTokens out of \c FormatTokens with required extra information.
13 ///
14 //===----------------------------------------------------------------------===//
15 
16 #include "TokenAnnotator.h"
17 #include "clang/Basic/SourceManager.h"
18 #include "llvm/ADT/SmallPtrSet.h"
19 #include "llvm/Support/Debug.h"
20 
21 #define DEBUG_TYPE "format-token-annotator"
22 
23 namespace clang {
24 namespace format {
25 
26 namespace {
27 
28 /// \brief A parser that gathers additional information about tokens.
29 ///
30 /// The \c TokenAnnotator tries to match parenthesis and square brakets and
31 /// store a parenthesis levels. It also tries to resolve matching "<" and ">"
32 /// into template parameter lists.
33 class AnnotatingParser {
34 public:
35   AnnotatingParser(const FormatStyle &Style, AnnotatedLine &Line,
36                    const AdditionalKeywords &Keywords)
37       : Style(Style), Line(Line), CurrentToken(Line.First), AutoFound(false),
38         Keywords(Keywords) {
39     Contexts.push_back(Context(tok::unknown, 1, /*IsExpression=*/false));
40     resetTokenMetadata(CurrentToken);
41   }
42 
43 private:
44   bool parseAngle() {
45     if (!CurrentToken)
46       return false;
47     FormatToken *Left = CurrentToken->Previous;
48     Left->ParentBracket = Contexts.back().ContextKind;
49     ScopedContextCreator ContextCreator(*this, tok::less, 10);
50 
51     // If this angle is in the context of an expression, we need to be more
52     // hesitant to detect it as opening template parameters.
53     bool InExprContext = Contexts.back().IsExpression;
54 
55     Contexts.back().IsExpression = false;
56     // If there's a template keyword before the opening angle bracket, this is a
57     // template parameter, not an argument.
58     Contexts.back().InTemplateArgument =
59         Left->Previous && Left->Previous->Tok.isNot(tok::kw_template);
60 
61     if (Style.Language == FormatStyle::LK_Java &&
62         CurrentToken->is(tok::question))
63       next();
64 
65     while (CurrentToken) {
66       if (CurrentToken->is(tok::greater)) {
67         Left->MatchingParen = CurrentToken;
68         CurrentToken->MatchingParen = Left;
69         CurrentToken->Type = TT_TemplateCloser;
70         next();
71         return true;
72       }
73       if (CurrentToken->is(tok::question) &&
74           Style.Language == FormatStyle::LK_Java) {
75         next();
76         continue;
77       }
78       if (CurrentToken->isOneOf(tok::r_paren, tok::r_square, tok::r_brace) ||
79           (CurrentToken->isOneOf(tok::colon, tok::question) && InExprContext))
80         return false;
81       // If a && or || is found and interpreted as a binary operator, this set
82       // of angles is likely part of something like "a < b && c > d". If the
83       // angles are inside an expression, the ||/&& might also be a binary
84       // operator that was misinterpreted because we are parsing template
85       // parameters.
86       // FIXME: This is getting out of hand, write a decent parser.
87       if (CurrentToken->Previous->isOneOf(tok::pipepipe, tok::ampamp) &&
88           CurrentToken->Previous->is(TT_BinaryOperator) &&
89           Contexts[Contexts.size() - 2].IsExpression &&
90           !Line.startsWith(tok::kw_template))
91         return false;
92       updateParameterCount(Left, CurrentToken);
93       if (!consumeToken())
94         return false;
95     }
96     return false;
97   }
98 
99   bool parseParens(bool LookForDecls = false) {
100     if (!CurrentToken)
101       return false;
102     FormatToken *Left = CurrentToken->Previous;
103     Left->ParentBracket = Contexts.back().ContextKind;
104     ScopedContextCreator ContextCreator(*this, tok::l_paren, 1);
105 
106     // FIXME: This is a bit of a hack. Do better.
107     Contexts.back().ColonIsForRangeExpr =
108         Contexts.size() == 2 && Contexts[0].ColonIsForRangeExpr;
109 
110     bool StartsObjCMethodExpr = false;
111     if (CurrentToken->is(tok::caret)) {
112       // (^ can start a block type.
113       Left->Type = TT_ObjCBlockLParen;
114     } else if (FormatToken *MaybeSel = Left->Previous) {
115       // @selector( starts a selector.
116       if (MaybeSel->isObjCAtKeyword(tok::objc_selector) && MaybeSel->Previous &&
117           MaybeSel->Previous->is(tok::at)) {
118         StartsObjCMethodExpr = true;
119       }
120     }
121 
122     if (Left->Previous &&
123         (Left->Previous->isOneOf(tok::kw_static_assert, tok::kw_decltype,
124                                  tok::kw_if, tok::kw_while, tok::l_paren,
125                                  tok::comma) ||
126          Left->Previous->is(TT_BinaryOperator))) {
127       // static_assert, if and while usually contain expressions.
128       Contexts.back().IsExpression = true;
129     } else if (Left->Previous && Left->Previous->is(tok::r_square) &&
130                Left->Previous->MatchingParen &&
131                Left->Previous->MatchingParen->is(TT_LambdaLSquare)) {
132       // This is a parameter list of a lambda expression.
133       Contexts.back().IsExpression = false;
134     } else if (Line.InPPDirective &&
135                (!Left->Previous ||
136                 !Left->Previous->isOneOf(tok::identifier,
137                                          TT_OverloadedOperator))) {
138       Contexts.back().IsExpression = true;
139     } else if (Contexts[Contexts.size() - 2].CaretFound) {
140       // This is the parameter list of an ObjC block.
141       Contexts.back().IsExpression = false;
142     } else if (Left->Previous && Left->Previous->is(tok::kw___attribute)) {
143       Left->Type = TT_AttributeParen;
144     } else if (Left->Previous && Left->Previous->is(TT_ForEachMacro)) {
145       // The first argument to a foreach macro is a declaration.
146       Contexts.back().IsForEachMacro = true;
147       Contexts.back().IsExpression = false;
148     } else if (Left->Previous && Left->Previous->MatchingParen &&
149                Left->Previous->MatchingParen->is(TT_ObjCBlockLParen)) {
150       Contexts.back().IsExpression = false;
151     }
152 
153     if (StartsObjCMethodExpr) {
154       Contexts.back().ColonIsObjCMethodExpr = true;
155       Left->Type = TT_ObjCMethodExpr;
156     }
157 
158     bool MightBeFunctionType = CurrentToken->isOneOf(tok::star, tok::amp);
159     bool HasMultipleLines = false;
160     bool HasMultipleParametersOnALine = false;
161     bool MightBeObjCForRangeLoop =
162         Left->Previous && Left->Previous->is(tok::kw_for);
163     while (CurrentToken) {
164       // LookForDecls is set when "if (" has been seen. Check for
165       // 'identifier' '*' 'identifier' followed by not '=' -- this
166       // '*' has to be a binary operator but determineStarAmpUsage() will
167       // categorize it as an unary operator, so set the right type here.
168       if (LookForDecls && CurrentToken->Next) {
169         FormatToken *Prev = CurrentToken->getPreviousNonComment();
170         if (Prev) {
171           FormatToken *PrevPrev = Prev->getPreviousNonComment();
172           FormatToken *Next = CurrentToken->Next;
173           if (PrevPrev && PrevPrev->is(tok::identifier) &&
174               Prev->isOneOf(tok::star, tok::amp, tok::ampamp) &&
175               CurrentToken->is(tok::identifier) && Next->isNot(tok::equal)) {
176             Prev->Type = TT_BinaryOperator;
177             LookForDecls = false;
178           }
179         }
180       }
181 
182       if (CurrentToken->Previous->is(TT_PointerOrReference) &&
183           CurrentToken->Previous->Previous->isOneOf(tok::l_paren,
184                                                     tok::coloncolon))
185         MightBeFunctionType = true;
186       if (CurrentToken->Previous->is(TT_BinaryOperator))
187         Contexts.back().IsExpression = true;
188       if (CurrentToken->is(tok::r_paren)) {
189         if (MightBeFunctionType && CurrentToken->Next &&
190             (CurrentToken->Next->is(tok::l_paren) ||
191              (CurrentToken->Next->is(tok::l_square) &&
192               !Contexts.back().IsExpression)))
193           Left->Type = TT_FunctionTypeLParen;
194         Left->MatchingParen = CurrentToken;
195         CurrentToken->MatchingParen = Left;
196 
197         if (StartsObjCMethodExpr) {
198           CurrentToken->Type = TT_ObjCMethodExpr;
199           if (Contexts.back().FirstObjCSelectorName) {
200             Contexts.back().FirstObjCSelectorName->LongestObjCSelectorName =
201                 Contexts.back().LongestObjCSelectorName;
202           }
203         }
204 
205         if (Left->is(TT_AttributeParen))
206           CurrentToken->Type = TT_AttributeParen;
207         if (Left->Previous && Left->Previous->is(TT_JavaAnnotation))
208           CurrentToken->Type = TT_JavaAnnotation;
209         if (Left->Previous && Left->Previous->is(TT_LeadingJavaAnnotation))
210           CurrentToken->Type = TT_LeadingJavaAnnotation;
211 
212         if (!HasMultipleLines)
213           Left->PackingKind = PPK_Inconclusive;
214         else if (HasMultipleParametersOnALine)
215           Left->PackingKind = PPK_BinPacked;
216         else
217           Left->PackingKind = PPK_OnePerLine;
218 
219         next();
220         return true;
221       }
222       if (CurrentToken->isOneOf(tok::r_square, tok::r_brace))
223         return false;
224 
225       if (CurrentToken->is(tok::l_brace))
226         Left->Type = TT_Unknown; // Not TT_ObjCBlockLParen
227       if (CurrentToken->is(tok::comma) && CurrentToken->Next &&
228           !CurrentToken->Next->HasUnescapedNewline &&
229           !CurrentToken->Next->isTrailingComment())
230         HasMultipleParametersOnALine = true;
231       if (CurrentToken->isOneOf(tok::kw_const, tok::kw_auto) ||
232           CurrentToken->isSimpleTypeSpecifier())
233         Contexts.back().IsExpression = false;
234       if (CurrentToken->isOneOf(tok::semi, tok::colon))
235         MightBeObjCForRangeLoop = false;
236       if (MightBeObjCForRangeLoop && CurrentToken->is(Keywords.kw_in))
237         CurrentToken->Type = TT_ObjCForIn;
238       // When we discover a 'new', we set CanBeExpression to 'false' in order to
239       // parse the type correctly. Reset that after a comma.
240       if (CurrentToken->is(tok::comma))
241         Contexts.back().CanBeExpression = true;
242 
243       FormatToken *Tok = CurrentToken;
244       if (!consumeToken())
245         return false;
246       updateParameterCount(Left, Tok);
247       if (CurrentToken && CurrentToken->HasUnescapedNewline)
248         HasMultipleLines = true;
249     }
250     return false;
251   }
252 
253   bool parseSquare() {
254     if (!CurrentToken)
255       return false;
256 
257     // A '[' could be an index subscript (after an identifier or after
258     // ')' or ']'), it could be the start of an Objective-C method
259     // expression, or it could the start of an Objective-C array literal.
260     FormatToken *Left = CurrentToken->Previous;
261     Left->ParentBracket = Contexts.back().ContextKind;
262     FormatToken *Parent = Left->getPreviousNonComment();
263     bool StartsObjCMethodExpr =
264         Style.Language == FormatStyle::LK_Cpp &&
265         Contexts.back().CanBeExpression && Left->isNot(TT_LambdaLSquare) &&
266         CurrentToken->isNot(tok::l_brace) &&
267         (!Parent ||
268          Parent->isOneOf(tok::colon, tok::l_square, tok::l_paren,
269                          tok::kw_return, tok::kw_throw) ||
270          Parent->isUnaryOperator() ||
271          Parent->isOneOf(TT_ObjCForIn, TT_CastRParen) ||
272          getBinOpPrecedence(Parent->Tok.getKind(), true, true) > prec::Unknown);
273     bool ColonFound = false;
274 
275     unsigned BindingIncrease = 1;
276     if (Left->is(TT_Unknown)) {
277       if (StartsObjCMethodExpr) {
278         Left->Type = TT_ObjCMethodExpr;
279       } else if (Style.Language == FormatStyle::LK_JavaScript && Parent &&
280                  Contexts.back().ContextKind == tok::l_brace &&
281                  Parent->isOneOf(tok::l_brace, tok::comma)) {
282         Left->Type = TT_JsComputedPropertyName;
283       } else if (Parent &&
284                  Parent->isOneOf(tok::at, tok::equal, tok::comma, tok::l_paren,
285                                  tok::l_square, tok::question, tok::colon,
286                                  tok::kw_return)) {
287         Left->Type = TT_ArrayInitializerLSquare;
288       } else {
289         BindingIncrease = 10;
290         Left->Type = TT_ArraySubscriptLSquare;
291       }
292     }
293 
294     ScopedContextCreator ContextCreator(*this, tok::l_square, BindingIncrease);
295     Contexts.back().IsExpression = true;
296     Contexts.back().ColonIsObjCMethodExpr = StartsObjCMethodExpr;
297 
298     while (CurrentToken) {
299       if (CurrentToken->is(tok::r_square)) {
300         if (CurrentToken->Next && CurrentToken->Next->is(tok::l_paren) &&
301             Left->is(TT_ObjCMethodExpr)) {
302           // An ObjC method call is rarely followed by an open parenthesis.
303           // FIXME: Do we incorrectly label ":" with this?
304           StartsObjCMethodExpr = false;
305           Left->Type = TT_Unknown;
306         }
307         if (StartsObjCMethodExpr && CurrentToken->Previous != Left) {
308           CurrentToken->Type = TT_ObjCMethodExpr;
309           // determineStarAmpUsage() thinks that '*' '[' is allocating an
310           // array of pointers, but if '[' starts a selector then '*' is a
311           // binary operator.
312           if (Parent && Parent->is(TT_PointerOrReference))
313             Parent->Type = TT_BinaryOperator;
314         }
315         Left->MatchingParen = CurrentToken;
316         CurrentToken->MatchingParen = Left;
317         if (Contexts.back().FirstObjCSelectorName) {
318           Contexts.back().FirstObjCSelectorName->LongestObjCSelectorName =
319               Contexts.back().LongestObjCSelectorName;
320           if (Left->BlockParameterCount > 1)
321             Contexts.back().FirstObjCSelectorName->LongestObjCSelectorName = 0;
322         }
323         next();
324         return true;
325       }
326       if (CurrentToken->isOneOf(tok::r_paren, tok::r_brace))
327         return false;
328       if (CurrentToken->is(tok::colon)) {
329         if (Left->is(TT_ArraySubscriptLSquare)) {
330           Left->Type = TT_ObjCMethodExpr;
331           StartsObjCMethodExpr = true;
332           Contexts.back().ColonIsObjCMethodExpr = true;
333           if (Parent && Parent->is(tok::r_paren))
334             Parent->Type = TT_CastRParen;
335         }
336         ColonFound = true;
337       }
338       if (CurrentToken->is(tok::comma) && Left->is(TT_ObjCMethodExpr) &&
339           !ColonFound)
340         Left->Type = TT_ArrayInitializerLSquare;
341       FormatToken *Tok = CurrentToken;
342       if (!consumeToken())
343         return false;
344       updateParameterCount(Left, Tok);
345     }
346     return false;
347   }
348 
349   bool parseBrace() {
350     if (CurrentToken) {
351       FormatToken *Left = CurrentToken->Previous;
352       Left->ParentBracket = Contexts.back().ContextKind;
353 
354       if (Contexts.back().CaretFound)
355         Left->Type = TT_ObjCBlockLBrace;
356       Contexts.back().CaretFound = false;
357 
358       ScopedContextCreator ContextCreator(*this, tok::l_brace, 1);
359       Contexts.back().ColonIsDictLiteral = true;
360       if (Left->BlockKind == BK_BracedInit)
361         Contexts.back().IsExpression = true;
362 
363       while (CurrentToken) {
364         if (CurrentToken->is(tok::r_brace)) {
365           Left->MatchingParen = CurrentToken;
366           CurrentToken->MatchingParen = Left;
367           next();
368           return true;
369         }
370         if (CurrentToken->isOneOf(tok::r_paren, tok::r_square))
371           return false;
372         updateParameterCount(Left, CurrentToken);
373         if (CurrentToken->isOneOf(tok::colon, tok::l_brace)) {
374           FormatToken *Previous = CurrentToken->getPreviousNonComment();
375           if (((CurrentToken->is(tok::colon) &&
376                 (!Contexts.back().ColonIsDictLiteral ||
377                  Style.Language != FormatStyle::LK_Cpp)) ||
378                Style.Language == FormatStyle::LK_Proto) &&
379               Previous->Tok.getIdentifierInfo())
380             Previous->Type = TT_SelectorName;
381           if (CurrentToken->is(tok::colon) ||
382               Style.Language == FormatStyle::LK_JavaScript)
383             Left->Type = TT_DictLiteral;
384         }
385         if (!consumeToken())
386           return false;
387       }
388     }
389     return true;
390   }
391 
392   void updateParameterCount(FormatToken *Left, FormatToken *Current) {
393     if (Current->is(tok::l_brace) && !Current->is(TT_DictLiteral))
394       ++Left->BlockParameterCount;
395     if (Current->is(tok::comma)) {
396       ++Left->ParameterCount;
397       if (!Left->Role)
398         Left->Role.reset(new CommaSeparatedList(Style));
399       Left->Role->CommaFound(Current);
400     } else if (Left->ParameterCount == 0 && Current->isNot(tok::comment)) {
401       Left->ParameterCount = 1;
402     }
403   }
404 
405   bool parseConditional() {
406     while (CurrentToken) {
407       if (CurrentToken->is(tok::colon)) {
408         CurrentToken->Type = TT_ConditionalExpr;
409         next();
410         return true;
411       }
412       if (!consumeToken())
413         return false;
414     }
415     return false;
416   }
417 
418   bool parseTemplateDeclaration() {
419     if (CurrentToken && CurrentToken->is(tok::less)) {
420       CurrentToken->Type = TT_TemplateOpener;
421       next();
422       if (!parseAngle())
423         return false;
424       if (CurrentToken)
425         CurrentToken->Previous->ClosesTemplateDeclaration = true;
426       return true;
427     }
428     return false;
429   }
430 
431   bool consumeToken() {
432     FormatToken *Tok = CurrentToken;
433     next();
434     switch (Tok->Tok.getKind()) {
435     case tok::plus:
436     case tok::minus:
437       if (!Tok->Previous && Line.MustBeDeclaration)
438         Tok->Type = TT_ObjCMethodSpecifier;
439       break;
440     case tok::colon:
441       if (!Tok->Previous)
442         return false;
443       // Colons from ?: are handled in parseConditional().
444       if (Style.Language == FormatStyle::LK_JavaScript) {
445         if (Contexts.back().ColonIsForRangeExpr || // colon in for loop
446             (Contexts.size() == 1 &&               // switch/case labels
447              !Line.First->isOneOf(tok::kw_enum, tok::kw_case)) ||
448             Contexts.back().ContextKind == tok::l_paren ||  // function params
449             Contexts.back().ContextKind == tok::l_square || // array type
450             (Contexts.size() == 1 &&
451              Line.MustBeDeclaration)) { // method/property declaration
452           Tok->Type = TT_JsTypeColon;
453           break;
454         }
455       }
456       if (Contexts.back().ColonIsDictLiteral) {
457         Tok->Type = TT_DictLiteral;
458       } else if (Contexts.back().ColonIsObjCMethodExpr ||
459                  Line.startsWith(TT_ObjCMethodSpecifier)) {
460         Tok->Type = TT_ObjCMethodExpr;
461         Tok->Previous->Type = TT_SelectorName;
462         if (Tok->Previous->ColumnWidth >
463             Contexts.back().LongestObjCSelectorName) {
464           Contexts.back().LongestObjCSelectorName = Tok->Previous->ColumnWidth;
465         }
466         if (!Contexts.back().FirstObjCSelectorName)
467           Contexts.back().FirstObjCSelectorName = Tok->Previous;
468       } else if (Contexts.back().ColonIsForRangeExpr) {
469         Tok->Type = TT_RangeBasedForLoopColon;
470       } else if (CurrentToken && CurrentToken->is(tok::numeric_constant)) {
471         Tok->Type = TT_BitFieldColon;
472       } else if (Contexts.size() == 1 &&
473                  !Line.First->isOneOf(tok::kw_enum, tok::kw_case)) {
474         if (Tok->Previous->is(tok::r_paren))
475           Tok->Type = TT_CtorInitializerColon;
476         else
477           Tok->Type = TT_InheritanceColon;
478       } else if (Tok->Previous->is(tok::identifier) && Tok->Next &&
479                  Tok->Next->isOneOf(tok::r_paren, tok::comma)) {
480         // This handles a special macro in ObjC code where selectors including
481         // the colon are passed as macro arguments.
482         Tok->Type = TT_ObjCMethodExpr;
483       } else if (Contexts.back().ContextKind == tok::l_paren) {
484         Tok->Type = TT_InlineASMColon;
485       }
486       break;
487     case tok::kw_if:
488     case tok::kw_while:
489       if (CurrentToken && CurrentToken->is(tok::l_paren)) {
490         next();
491         if (!parseParens(/*LookForDecls=*/true))
492           return false;
493       }
494       break;
495     case tok::kw_for:
496       Contexts.back().ColonIsForRangeExpr = true;
497       next();
498       if (!parseParens())
499         return false;
500       break;
501     case tok::l_paren:
502       // When faced with 'operator()()', the kw_operator handler incorrectly
503       // marks the first l_paren as a OverloadedOperatorLParen. Here, we make
504       // the first two parens OverloadedOperators and the second l_paren an
505       // OverloadedOperatorLParen.
506       if (Tok->Previous &&
507           Tok->Previous->is(tok::r_paren) &&
508           Tok->Previous->MatchingParen &&
509           Tok->Previous->MatchingParen->is(TT_OverloadedOperatorLParen)) {
510         Tok->Previous->Type = TT_OverloadedOperator;
511         Tok->Previous->MatchingParen->Type = TT_OverloadedOperator;
512         Tok->Type = TT_OverloadedOperatorLParen;
513       }
514 
515       if (!parseParens())
516         return false;
517       if (Line.MustBeDeclaration && Contexts.size() == 1 &&
518           !Contexts.back().IsExpression && !Line.startsWith(TT_ObjCProperty) &&
519           (!Tok->Previous ||
520            !Tok->Previous->isOneOf(tok::kw_decltype, tok::kw___attribute,
521                                    TT_LeadingJavaAnnotation)))
522         Line.MightBeFunctionDecl = true;
523       break;
524     case tok::l_square:
525       if (!parseSquare())
526         return false;
527       break;
528     case tok::l_brace:
529       if (!parseBrace())
530         return false;
531       break;
532     case tok::less:
533       if (!NonTemplateLess.count(Tok) &&
534           (!Tok->Previous ||
535            (!Tok->Previous->Tok.isLiteral() &&
536             !(Tok->Previous->is(tok::r_paren) && Contexts.size() > 1))) &&
537           parseAngle()) {
538         Tok->Type = TT_TemplateOpener;
539       } else {
540         Tok->Type = TT_BinaryOperator;
541         NonTemplateLess.insert(Tok);
542         CurrentToken = Tok;
543         next();
544       }
545       break;
546     case tok::r_paren:
547     case tok::r_square:
548       return false;
549     case tok::r_brace:
550       // Lines can start with '}'.
551       if (Tok->Previous)
552         return false;
553       break;
554     case tok::greater:
555       Tok->Type = TT_BinaryOperator;
556       break;
557     case tok::kw_operator:
558       while (CurrentToken &&
559              !CurrentToken->isOneOf(tok::l_paren, tok::semi, tok::r_paren)) {
560         if (CurrentToken->isOneOf(tok::star, tok::amp))
561           CurrentToken->Type = TT_PointerOrReference;
562         consumeToken();
563         if (CurrentToken && CurrentToken->Previous->is(TT_BinaryOperator))
564           CurrentToken->Previous->Type = TT_OverloadedOperator;
565       }
566       if (CurrentToken) {
567         CurrentToken->Type = TT_OverloadedOperatorLParen;
568         if (CurrentToken->Previous->is(TT_BinaryOperator))
569           CurrentToken->Previous->Type = TT_OverloadedOperator;
570       }
571       break;
572     case tok::question:
573       if (Style.Language == FormatStyle::LK_JavaScript && Tok->Next &&
574           Tok->Next->isOneOf(tok::semi, tok::comma, tok::colon, tok::r_paren,
575                              tok::r_brace)) {
576         // Question marks before semicolons, colons, etc. indicate optional
577         // types (fields, parameters), e.g.
578         //   function(x?: string, y?) {...}
579         //   class X { y?; }
580         Tok->Type = TT_JsTypeOptionalQuestion;
581         break;
582       }
583       // Declarations cannot be conditional expressions, this can only be part
584       // of a type declaration.
585       if (Line.MustBeDeclaration &&
586           Style.Language == FormatStyle::LK_JavaScript)
587         break;
588       parseConditional();
589       break;
590     case tok::kw_template:
591       parseTemplateDeclaration();
592       break;
593     case tok::comma:
594       if (Contexts.back().InCtorInitializer)
595         Tok->Type = TT_CtorInitializerComma;
596       else if (Contexts.back().FirstStartOfName &&
597                (Contexts.size() == 1 || Line.startsWith(tok::kw_for))) {
598         Contexts.back().FirstStartOfName->PartOfMultiVariableDeclStmt = true;
599         Line.IsMultiVariableDeclStmt = true;
600       }
601       if (Contexts.back().IsForEachMacro)
602         Contexts.back().IsExpression = true;
603       break;
604     default:
605       break;
606     }
607     return true;
608   }
609 
610   void parseIncludeDirective() {
611     if (CurrentToken && CurrentToken->is(tok::less)) {
612       next();
613       while (CurrentToken) {
614         if (CurrentToken->isNot(tok::comment) || CurrentToken->Next)
615           CurrentToken->Type = TT_ImplicitStringLiteral;
616         next();
617       }
618     }
619   }
620 
621   void parseWarningOrError() {
622     next();
623     // We still want to format the whitespace left of the first token of the
624     // warning or error.
625     next();
626     while (CurrentToken) {
627       CurrentToken->Type = TT_ImplicitStringLiteral;
628       next();
629     }
630   }
631 
632   void parsePragma() {
633     next(); // Consume "pragma".
634     if (CurrentToken &&
635         CurrentToken->isOneOf(Keywords.kw_mark, Keywords.kw_option)) {
636       bool IsMark = CurrentToken->is(Keywords.kw_mark);
637       next(); // Consume "mark".
638       next(); // Consume first token (so we fix leading whitespace).
639       while (CurrentToken) {
640         if (IsMark || CurrentToken->Previous->is(TT_BinaryOperator))
641           CurrentToken->Type = TT_ImplicitStringLiteral;
642         next();
643       }
644     }
645   }
646 
647   LineType parsePreprocessorDirective() {
648     LineType Type = LT_PreprocessorDirective;
649     next();
650     if (!CurrentToken)
651       return Type;
652     if (CurrentToken->Tok.is(tok::numeric_constant)) {
653       CurrentToken->SpacesRequiredBefore = 1;
654       return Type;
655     }
656     // Hashes in the middle of a line can lead to any strange token
657     // sequence.
658     if (!CurrentToken->Tok.getIdentifierInfo())
659       return Type;
660     switch (CurrentToken->Tok.getIdentifierInfo()->getPPKeywordID()) {
661     case tok::pp_include:
662     case tok::pp_include_next:
663     case tok::pp_import:
664       next();
665       parseIncludeDirective();
666       Type = LT_ImportStatement;
667       break;
668     case tok::pp_error:
669     case tok::pp_warning:
670       parseWarningOrError();
671       break;
672     case tok::pp_pragma:
673       parsePragma();
674       break;
675     case tok::pp_if:
676     case tok::pp_elif:
677       Contexts.back().IsExpression = true;
678       parseLine();
679       break;
680     default:
681       break;
682     }
683     while (CurrentToken)
684       next();
685     return Type;
686   }
687 
688 public:
689   LineType parseLine() {
690     NonTemplateLess.clear();
691     if (CurrentToken->is(tok::hash))
692       return parsePreprocessorDirective();
693 
694     // Directly allow to 'import <string-literal>' to support protocol buffer
695     // definitions (code.google.com/p/protobuf) or missing "#" (either way we
696     // should not break the line).
697     IdentifierInfo *Info = CurrentToken->Tok.getIdentifierInfo();
698     if ((Style.Language == FormatStyle::LK_Java &&
699          CurrentToken->is(Keywords.kw_package)) ||
700         (Info && Info->getPPKeywordID() == tok::pp_import &&
701          CurrentToken->Next &&
702          CurrentToken->Next->isOneOf(tok::string_literal, tok::identifier,
703                                      tok::kw_static))) {
704       next();
705       parseIncludeDirective();
706       return LT_ImportStatement;
707     }
708 
709     // If this line starts and ends in '<' and '>', respectively, it is likely
710     // part of "#define <a/b.h>".
711     if (CurrentToken->is(tok::less) && Line.Last->is(tok::greater)) {
712       parseIncludeDirective();
713       return LT_ImportStatement;
714     }
715 
716     // In .proto files, top-level options are very similar to import statements
717     // and should not be line-wrapped.
718     if (Style.Language == FormatStyle::LK_Proto && Line.Level == 0 &&
719         CurrentToken->is(Keywords.kw_option)) {
720       next();
721       if (CurrentToken && CurrentToken->is(tok::identifier))
722         return LT_ImportStatement;
723     }
724 
725     bool KeywordVirtualFound = false;
726     bool ImportStatement = false;
727     while (CurrentToken) {
728       if (CurrentToken->is(tok::kw_virtual))
729         KeywordVirtualFound = true;
730       if (isImportStatement(*CurrentToken))
731         ImportStatement = true;
732       if (!consumeToken())
733         return LT_Invalid;
734     }
735     if (KeywordVirtualFound)
736       return LT_VirtualFunctionDecl;
737     if (ImportStatement)
738       return LT_ImportStatement;
739 
740     if (Line.startsWith(TT_ObjCMethodSpecifier)) {
741       if (Contexts.back().FirstObjCSelectorName)
742         Contexts.back().FirstObjCSelectorName->LongestObjCSelectorName =
743             Contexts.back().LongestObjCSelectorName;
744       return LT_ObjCMethodDecl;
745     }
746 
747     return LT_Other;
748   }
749 
750 private:
751   bool isImportStatement(const FormatToken &Tok) {
752     // FIXME: Closure-library specific stuff should not be hard-coded but be
753     // configurable.
754     return Style.Language == FormatStyle::LK_JavaScript &&
755            Tok.TokenText == "goog" && Tok.Next && Tok.Next->is(tok::period) &&
756            Tok.Next->Next && (Tok.Next->Next->TokenText == "module" ||
757                               Tok.Next->Next->TokenText == "provide" ||
758                               Tok.Next->Next->TokenText == "require" ||
759                               Tok.Next->Next->TokenText == "setTestOnly") &&
760            Tok.Next->Next->Next && Tok.Next->Next->Next->is(tok::l_paren);
761   }
762 
763   void resetTokenMetadata(FormatToken *Token) {
764     if (!Token)
765       return;
766 
767     // Reset token type in case we have already looked at it and then
768     // recovered from an error (e.g. failure to find the matching >).
769     if (!CurrentToken->isOneOf(TT_LambdaLSquare, TT_ForEachMacro,
770                                TT_FunctionLBrace, TT_ImplicitStringLiteral,
771                                TT_InlineASMBrace, TT_JsFatArrow, TT_LambdaArrow,
772                                TT_RegexLiteral))
773       CurrentToken->Type = TT_Unknown;
774     CurrentToken->Role.reset();
775     CurrentToken->MatchingParen = nullptr;
776     CurrentToken->FakeLParens.clear();
777     CurrentToken->FakeRParens = 0;
778   }
779 
780   void next() {
781     if (CurrentToken) {
782       CurrentToken->NestingLevel = Contexts.size() - 1;
783       CurrentToken->BindingStrength = Contexts.back().BindingStrength;
784       modifyContext(*CurrentToken);
785       determineTokenType(*CurrentToken);
786       CurrentToken = CurrentToken->Next;
787     }
788 
789     resetTokenMetadata(CurrentToken);
790   }
791 
792   /// \brief A struct to hold information valid in a specific context, e.g.
793   /// a pair of parenthesis.
794   struct Context {
795     Context(tok::TokenKind ContextKind, unsigned BindingStrength,
796             bool IsExpression)
797         : ContextKind(ContextKind), BindingStrength(BindingStrength),
798           IsExpression(IsExpression) {}
799 
800     tok::TokenKind ContextKind;
801     unsigned BindingStrength;
802     bool IsExpression;
803     unsigned LongestObjCSelectorName = 0;
804     bool ColonIsForRangeExpr = false;
805     bool ColonIsDictLiteral = false;
806     bool ColonIsObjCMethodExpr = false;
807     FormatToken *FirstObjCSelectorName = nullptr;
808     FormatToken *FirstStartOfName = nullptr;
809     bool CanBeExpression = true;
810     bool InTemplateArgument = false;
811     bool InCtorInitializer = false;
812     bool CaretFound = false;
813     bool IsForEachMacro = false;
814   };
815 
816   /// \brief Puts a new \c Context onto the stack \c Contexts for the lifetime
817   /// of each instance.
818   struct ScopedContextCreator {
819     AnnotatingParser &P;
820 
821     ScopedContextCreator(AnnotatingParser &P, tok::TokenKind ContextKind,
822                          unsigned Increase)
823         : P(P) {
824       P.Contexts.push_back(Context(ContextKind,
825                                    P.Contexts.back().BindingStrength + Increase,
826                                    P.Contexts.back().IsExpression));
827     }
828 
829     ~ScopedContextCreator() { P.Contexts.pop_back(); }
830   };
831 
832   void modifyContext(const FormatToken &Current) {
833     if (Current.getPrecedence() == prec::Assignment &&
834         !Line.First->isOneOf(tok::kw_template, tok::kw_using) &&
835         (!Current.Previous || Current.Previous->isNot(tok::kw_operator))) {
836       Contexts.back().IsExpression = true;
837       if (!Line.startsWith(TT_UnaryOperator)) {
838         for (FormatToken *Previous = Current.Previous;
839              Previous && Previous->Previous &&
840              !Previous->Previous->isOneOf(tok::comma, tok::semi);
841              Previous = Previous->Previous) {
842           if (Previous->isOneOf(tok::r_square, tok::r_paren)) {
843             Previous = Previous->MatchingParen;
844             if (!Previous)
845               break;
846           }
847           if (Previous->opensScope())
848             break;
849           if (Previous->isOneOf(TT_BinaryOperator, TT_UnaryOperator) &&
850               Previous->isOneOf(tok::star, tok::amp, tok::ampamp) &&
851               Previous->Previous && Previous->Previous->isNot(tok::equal))
852             Previous->Type = TT_PointerOrReference;
853         }
854       }
855     } else if (Current.is(tok::lessless) &&
856                (!Current.Previous || !Current.Previous->is(tok::kw_operator))) {
857       Contexts.back().IsExpression = true;
858     } else if (Current.isOneOf(tok::kw_return, tok::kw_throw)) {
859       Contexts.back().IsExpression = true;
860     } else if (Current.is(TT_TrailingReturnArrow)) {
861       Contexts.back().IsExpression = false;
862     } else if (Current.is(TT_LambdaArrow) || Current.is(Keywords.kw_assert)) {
863       Contexts.back().IsExpression = Style.Language == FormatStyle::LK_Java;
864     } else if (Current.is(tok::l_paren) && !Line.MustBeDeclaration &&
865                !Line.InPPDirective &&
866                (!Current.Previous ||
867                 Current.Previous->isNot(tok::kw_decltype))) {
868       bool ParametersOfFunctionType =
869           Current.Previous && Current.Previous->is(tok::r_paren) &&
870           Current.Previous->MatchingParen &&
871           Current.Previous->MatchingParen->is(TT_FunctionTypeLParen);
872       bool IsForOrCatch = Current.Previous &&
873                           Current.Previous->isOneOf(tok::kw_for, tok::kw_catch);
874       Contexts.back().IsExpression = !ParametersOfFunctionType && !IsForOrCatch;
875     } else if (Current.isOneOf(tok::r_paren, tok::greater, tok::comma)) {
876       for (FormatToken *Previous = Current.Previous;
877            Previous && Previous->isOneOf(tok::star, tok::amp);
878            Previous = Previous->Previous)
879         Previous->Type = TT_PointerOrReference;
880       if (Line.MustBeDeclaration)
881         Contexts.back().IsExpression = Contexts.front().InCtorInitializer;
882     } else if (Current.Previous &&
883                Current.Previous->is(TT_CtorInitializerColon)) {
884       Contexts.back().IsExpression = true;
885       Contexts.back().InCtorInitializer = true;
886     } else if (Current.is(tok::kw_new)) {
887       Contexts.back().CanBeExpression = false;
888     } else if (Current.isOneOf(tok::semi, tok::exclaim)) {
889       // This should be the condition or increment in a for-loop.
890       Contexts.back().IsExpression = true;
891     }
892   }
893 
894   void determineTokenType(FormatToken &Current) {
895     if (!Current.is(TT_Unknown))
896       // The token type is already known.
897       return;
898 
899     // Line.MightBeFunctionDecl can only be true after the parentheses of a
900     // function declaration have been found. In this case, 'Current' is a
901     // trailing token of this declaration and thus cannot be a name.
902     if (Current.is(Keywords.kw_instanceof)) {
903       Current.Type = TT_BinaryOperator;
904     } else if (isStartOfName(Current) &&
905                (!Line.MightBeFunctionDecl || Current.NestingLevel != 0)) {
906       Contexts.back().FirstStartOfName = &Current;
907       Current.Type = TT_StartOfName;
908     } else if (Current.isOneOf(tok::kw_auto, tok::kw___auto_type)) {
909       AutoFound = true;
910     } else if (Current.is(tok::arrow) &&
911                Style.Language == FormatStyle::LK_Java) {
912       Current.Type = TT_LambdaArrow;
913     } else if (Current.is(tok::arrow) && AutoFound && Line.MustBeDeclaration &&
914                Current.NestingLevel == 0) {
915       Current.Type = TT_TrailingReturnArrow;
916     } else if (Current.isOneOf(tok::star, tok::amp, tok::ampamp)) {
917       Current.Type =
918           determineStarAmpUsage(Current, Contexts.back().CanBeExpression &&
919                                              Contexts.back().IsExpression,
920                                 Contexts.back().InTemplateArgument);
921     } else if (Current.isOneOf(tok::minus, tok::plus, tok::caret)) {
922       Current.Type = determinePlusMinusCaretUsage(Current);
923       if (Current.is(TT_UnaryOperator) && Current.is(tok::caret))
924         Contexts.back().CaretFound = true;
925     } else if (Current.isOneOf(tok::minusminus, tok::plusplus)) {
926       Current.Type = determineIncrementUsage(Current);
927     } else if (Current.isOneOf(tok::exclaim, tok::tilde)) {
928       Current.Type = TT_UnaryOperator;
929     } else if (Current.is(tok::question)) {
930       if (Style.Language == FormatStyle::LK_JavaScript &&
931           Line.MustBeDeclaration) {
932         // In JavaScript, `interface X { foo?(): bar; }` is an optional method
933         // on the interface, not a ternary expression.
934         Current.Type = TT_JsTypeOptionalQuestion;
935       } else {
936         Current.Type = TT_ConditionalExpr;
937       }
938     } else if (Current.isBinaryOperator() &&
939                (!Current.Previous || Current.Previous->isNot(tok::l_square))) {
940       Current.Type = TT_BinaryOperator;
941     } else if (Current.is(tok::comment)) {
942       if (Current.TokenText.startswith("/*")) {
943         if (Current.TokenText.endswith("*/"))
944           Current.Type = TT_BlockComment;
945         else
946           // The lexer has for some reason determined a comment here. But we
947           // cannot really handle it, if it isn't properly terminated.
948           Current.Tok.setKind(tok::unknown);
949       } else {
950         Current.Type = TT_LineComment;
951       }
952     } else if (Current.is(tok::r_paren)) {
953       if (rParenEndsCast(Current))
954         Current.Type = TT_CastRParen;
955       if (Current.MatchingParen && Current.Next &&
956           !Current.Next->isBinaryOperator() &&
957           !Current.Next->isOneOf(tok::semi, tok::colon, tok::l_brace))
958         if (FormatToken *BeforeParen = Current.MatchingParen->Previous)
959           if (BeforeParen->is(tok::identifier) &&
960               BeforeParen->TokenText == BeforeParen->TokenText.upper() &&
961               (!BeforeParen->Previous ||
962                BeforeParen->Previous->ClosesTemplateDeclaration))
963             Current.Type = TT_FunctionAnnotationRParen;
964     } else if (Current.is(tok::at) && Current.Next) {
965       if (Current.Next->isStringLiteral()) {
966         Current.Type = TT_ObjCStringLiteral;
967       } else {
968         switch (Current.Next->Tok.getObjCKeywordID()) {
969         case tok::objc_interface:
970         case tok::objc_implementation:
971         case tok::objc_protocol:
972           Current.Type = TT_ObjCDecl;
973           break;
974         case tok::objc_property:
975           Current.Type = TT_ObjCProperty;
976           break;
977         default:
978           break;
979         }
980       }
981     } else if (Current.is(tok::period)) {
982       FormatToken *PreviousNoComment = Current.getPreviousNonComment();
983       if (PreviousNoComment &&
984           PreviousNoComment->isOneOf(tok::comma, tok::l_brace))
985         Current.Type = TT_DesignatedInitializerPeriod;
986       else if (Style.Language == FormatStyle::LK_Java && Current.Previous &&
987                Current.Previous->isOneOf(TT_JavaAnnotation,
988                                          TT_LeadingJavaAnnotation)) {
989         Current.Type = Current.Previous->Type;
990       }
991     } else if (Current.isOneOf(tok::identifier, tok::kw_const) &&
992                Current.Previous &&
993                !Current.Previous->isOneOf(tok::equal, tok::at) &&
994                Line.MightBeFunctionDecl && Contexts.size() == 1) {
995       // Line.MightBeFunctionDecl can only be true after the parentheses of a
996       // function declaration have been found.
997       Current.Type = TT_TrailingAnnotation;
998     } else if ((Style.Language == FormatStyle::LK_Java ||
999                 Style.Language == FormatStyle::LK_JavaScript) &&
1000                Current.Previous) {
1001       if (Current.Previous->is(tok::at) &&
1002           Current.isNot(Keywords.kw_interface)) {
1003         const FormatToken &AtToken = *Current.Previous;
1004         const FormatToken *Previous = AtToken.getPreviousNonComment();
1005         if (!Previous || Previous->is(TT_LeadingJavaAnnotation))
1006           Current.Type = TT_LeadingJavaAnnotation;
1007         else
1008           Current.Type = TT_JavaAnnotation;
1009       } else if (Current.Previous->is(tok::period) &&
1010                  Current.Previous->isOneOf(TT_JavaAnnotation,
1011                                            TT_LeadingJavaAnnotation)) {
1012         Current.Type = Current.Previous->Type;
1013       }
1014     }
1015   }
1016 
1017   /// \brief Take a guess at whether \p Tok starts a name of a function or
1018   /// variable declaration.
1019   ///
1020   /// This is a heuristic based on whether \p Tok is an identifier following
1021   /// something that is likely a type.
1022   bool isStartOfName(const FormatToken &Tok) {
1023     if (Tok.isNot(tok::identifier) || !Tok.Previous)
1024       return false;
1025 
1026     if (Tok.Previous->isOneOf(TT_LeadingJavaAnnotation, Keywords.kw_instanceof))
1027       return false;
1028 
1029     // Skip "const" as it does not have an influence on whether this is a name.
1030     FormatToken *PreviousNotConst = Tok.Previous;
1031     while (PreviousNotConst && PreviousNotConst->is(tok::kw_const))
1032       PreviousNotConst = PreviousNotConst->Previous;
1033 
1034     if (!PreviousNotConst)
1035       return false;
1036 
1037     bool IsPPKeyword = PreviousNotConst->is(tok::identifier) &&
1038                        PreviousNotConst->Previous &&
1039                        PreviousNotConst->Previous->is(tok::hash);
1040 
1041     if (PreviousNotConst->is(TT_TemplateCloser))
1042       return PreviousNotConst && PreviousNotConst->MatchingParen &&
1043              PreviousNotConst->MatchingParen->Previous &&
1044              PreviousNotConst->MatchingParen->Previous->isNot(tok::period) &&
1045              PreviousNotConst->MatchingParen->Previous->isNot(tok::kw_template);
1046 
1047     if (PreviousNotConst->is(tok::r_paren) && PreviousNotConst->MatchingParen &&
1048         PreviousNotConst->MatchingParen->Previous &&
1049         PreviousNotConst->MatchingParen->Previous->is(tok::kw_decltype))
1050       return true;
1051 
1052     return (!IsPPKeyword &&
1053             PreviousNotConst->isOneOf(tok::identifier, tok::kw_auto)) ||
1054            PreviousNotConst->is(TT_PointerOrReference) ||
1055            PreviousNotConst->isSimpleTypeSpecifier();
1056   }
1057 
1058   /// \brief Determine whether ')' is ending a cast.
1059   bool rParenEndsCast(const FormatToken &Tok) {
1060     // C-style casts are only used in C++ and Java.
1061     if (Style.Language != FormatStyle::LK_Cpp &&
1062         Style.Language != FormatStyle::LK_Java)
1063       return false;
1064 
1065     // Empty parens aren't casts and there are no casts at the end of the line.
1066     if (Tok.Previous == Tok.MatchingParen || !Tok.Next || !Tok.MatchingParen)
1067       return false;
1068 
1069     FormatToken *LeftOfParens = Tok.MatchingParen->getPreviousNonComment();
1070     if (LeftOfParens) {
1071       // If there is an opening parenthesis left of the current parentheses,
1072       // look past it as these might be chained casts.
1073       if (LeftOfParens->is(tok::r_paren)) {
1074         if (!LeftOfParens->MatchingParen ||
1075             !LeftOfParens->MatchingParen->Previous)
1076           return false;
1077         LeftOfParens = LeftOfParens->MatchingParen->Previous;
1078       }
1079 
1080       // If there is an identifier (or with a few exceptions a keyword) right
1081       // before the parentheses, this is unlikely to be a cast.
1082       if (LeftOfParens->Tok.getIdentifierInfo() &&
1083           !LeftOfParens->isOneOf(Keywords.kw_in, tok::kw_return, tok::kw_case,
1084                                  tok::kw_delete))
1085         return false;
1086 
1087       // Certain other tokens right before the parentheses are also signals that
1088       // this cannot be a cast.
1089       if (LeftOfParens->isOneOf(tok::at, tok::r_square, TT_OverloadedOperator,
1090                                 TT_TemplateCloser))
1091         return false;
1092     }
1093 
1094     if (Tok.Next->is(tok::question))
1095       return false;
1096 
1097     // As Java has no function types, a "(" after the ")" likely means that this
1098     // is a cast.
1099     if (Style.Language == FormatStyle::LK_Java && Tok.Next->is(tok::l_paren))
1100       return true;
1101 
1102     // If a (non-string) literal follows, this is likely a cast.
1103     if (Tok.Next->isNot(tok::string_literal) &&
1104         (Tok.Next->Tok.isLiteral() ||
1105          Tok.Next->isOneOf(tok::kw_sizeof, tok::kw_alignof)))
1106       return true;
1107 
1108     // Heuristically try to determine whether the parentheses contain a type.
1109     bool ParensAreType =
1110         !Tok.Previous ||
1111         Tok.Previous->isOneOf(TT_PointerOrReference, TT_TemplateCloser) ||
1112         Tok.Previous->isSimpleTypeSpecifier();
1113     bool ParensCouldEndDecl =
1114         Tok.Next->isOneOf(tok::equal, tok::semi, tok::l_brace, tok::greater);
1115     if (ParensAreType && !ParensCouldEndDecl &&
1116         (Contexts.size() > 1 && Contexts[Contexts.size() - 2].IsExpression))
1117       return true;
1118 
1119     // At this point, we heuristically assume that there are no casts at the
1120     // start of the line. We assume that we have found most cases where there
1121     // are by the logic above, e.g. "(void)x;".
1122     if (!LeftOfParens)
1123       return false;
1124 
1125     // If the following token is an identifier, this is a cast. All cases where
1126     // this can be something else are handled above.
1127     if (Tok.Next->is(tok::identifier))
1128       return true;
1129 
1130     if (!Tok.Next->Next)
1131       return false;
1132 
1133     // If the next token after the parenthesis is a unary operator, assume
1134     // that this is cast, unless there are unexpected tokens inside the
1135     // parenthesis.
1136     bool NextIsUnary =
1137         Tok.Next->isUnaryOperator() || Tok.Next->isOneOf(tok::amp, tok::star);
1138     if (!NextIsUnary || Tok.Next->is(tok::plus) ||
1139         !Tok.Next->Next->isOneOf(tok::identifier, tok::numeric_constant))
1140       return false;
1141     // Search for unexpected tokens.
1142     for (FormatToken *Prev = Tok.Previous; Prev != Tok.MatchingParen;
1143          Prev = Prev->Previous) {
1144       if (!Prev->isOneOf(tok::kw_const, tok::identifier, tok::coloncolon))
1145         return false;
1146     }
1147     return true;
1148   }
1149 
1150   /// \brief Return the type of the given token assuming it is * or &.
1151   TokenType determineStarAmpUsage(const FormatToken &Tok, bool IsExpression,
1152                                   bool InTemplateArgument) {
1153     if (Style.Language == FormatStyle::LK_JavaScript)
1154       return TT_BinaryOperator;
1155 
1156     const FormatToken *PrevToken = Tok.getPreviousNonComment();
1157     if (!PrevToken)
1158       return TT_UnaryOperator;
1159 
1160     const FormatToken *NextToken = Tok.getNextNonComment();
1161     if (!NextToken ||
1162         NextToken->isOneOf(tok::arrow, Keywords.kw_final,
1163                            Keywords.kw_override) ||
1164         (NextToken->is(tok::l_brace) && !NextToken->getNextNonComment()))
1165       return TT_PointerOrReference;
1166 
1167     if (PrevToken->is(tok::coloncolon))
1168       return TT_PointerOrReference;
1169 
1170     if (PrevToken->isOneOf(tok::l_paren, tok::l_square, tok::l_brace,
1171                            tok::comma, tok::semi, tok::kw_return, tok::colon,
1172                            tok::equal, tok::kw_delete, tok::kw_sizeof) ||
1173         PrevToken->isOneOf(TT_BinaryOperator, TT_ConditionalExpr,
1174                            TT_UnaryOperator, TT_CastRParen))
1175       return TT_UnaryOperator;
1176 
1177     if (NextToken->is(tok::l_square) && NextToken->isNot(TT_LambdaLSquare))
1178       return TT_PointerOrReference;
1179     if (NextToken->is(tok::kw_operator) && !IsExpression)
1180       return TT_PointerOrReference;
1181     if (NextToken->isOneOf(tok::comma, tok::semi))
1182       return TT_PointerOrReference;
1183 
1184     if (PrevToken->is(tok::r_paren) && PrevToken->MatchingParen &&
1185         PrevToken->MatchingParen->Previous &&
1186         PrevToken->MatchingParen->Previous->isOneOf(tok::kw_typeof,
1187                                                     tok::kw_decltype))
1188       return TT_PointerOrReference;
1189 
1190     if (PrevToken->Tok.isLiteral() ||
1191         PrevToken->isOneOf(tok::r_paren, tok::r_square, tok::kw_true,
1192                            tok::kw_false, tok::r_brace) ||
1193         NextToken->Tok.isLiteral() ||
1194         NextToken->isOneOf(tok::kw_true, tok::kw_false) ||
1195         NextToken->isUnaryOperator() ||
1196         // If we know we're in a template argument, there are no named
1197         // declarations. Thus, having an identifier on the right-hand side
1198         // indicates a binary operator.
1199         (InTemplateArgument && NextToken->Tok.isAnyIdentifier()))
1200       return TT_BinaryOperator;
1201 
1202     // "&&(" is quite unlikely to be two successive unary "&".
1203     if (Tok.is(tok::ampamp) && NextToken && NextToken->is(tok::l_paren))
1204       return TT_BinaryOperator;
1205 
1206     // This catches some cases where evaluation order is used as control flow:
1207     //   aaa && aaa->f();
1208     const FormatToken *NextNextToken = NextToken->getNextNonComment();
1209     if (NextNextToken && NextNextToken->is(tok::arrow))
1210       return TT_BinaryOperator;
1211 
1212     // It is very unlikely that we are going to find a pointer or reference type
1213     // definition on the RHS of an assignment.
1214     if (IsExpression && !Contexts.back().CaretFound)
1215       return TT_BinaryOperator;
1216 
1217     return TT_PointerOrReference;
1218   }
1219 
1220   TokenType determinePlusMinusCaretUsage(const FormatToken &Tok) {
1221     const FormatToken *PrevToken = Tok.getPreviousNonComment();
1222     if (!PrevToken || PrevToken->is(TT_CastRParen))
1223       return TT_UnaryOperator;
1224 
1225     // Use heuristics to recognize unary operators.
1226     if (PrevToken->isOneOf(tok::equal, tok::l_paren, tok::comma, tok::l_square,
1227                            tok::question, tok::colon, tok::kw_return,
1228                            tok::kw_case, tok::at, tok::l_brace))
1229       return TT_UnaryOperator;
1230 
1231     // There can't be two consecutive binary operators.
1232     if (PrevToken->is(TT_BinaryOperator))
1233       return TT_UnaryOperator;
1234 
1235     // Fall back to marking the token as binary operator.
1236     return TT_BinaryOperator;
1237   }
1238 
1239   /// \brief Determine whether ++/-- are pre- or post-increments/-decrements.
1240   TokenType determineIncrementUsage(const FormatToken &Tok) {
1241     const FormatToken *PrevToken = Tok.getPreviousNonComment();
1242     if (!PrevToken || PrevToken->is(TT_CastRParen))
1243       return TT_UnaryOperator;
1244     if (PrevToken->isOneOf(tok::r_paren, tok::r_square, tok::identifier))
1245       return TT_TrailingUnaryOperator;
1246 
1247     return TT_UnaryOperator;
1248   }
1249 
1250   SmallVector<Context, 8> Contexts;
1251 
1252   const FormatStyle &Style;
1253   AnnotatedLine &Line;
1254   FormatToken *CurrentToken;
1255   bool AutoFound;
1256   const AdditionalKeywords &Keywords;
1257 
1258   // Set of "<" tokens that do not open a template parameter list. If parseAngle
1259   // determines that a specific token can't be a template opener, it will make
1260   // same decision irrespective of the decisions for tokens leading up to it.
1261   // Store this information to prevent this from causing exponential runtime.
1262   llvm::SmallPtrSet<FormatToken *, 16> NonTemplateLess;
1263 };
1264 
1265 static const int PrecedenceUnaryOperator = prec::PointerToMember + 1;
1266 static const int PrecedenceArrowAndPeriod = prec::PointerToMember + 2;
1267 
1268 /// \brief Parses binary expressions by inserting fake parenthesis based on
1269 /// operator precedence.
1270 class ExpressionParser {
1271 public:
1272   ExpressionParser(const FormatStyle &Style, const AdditionalKeywords &Keywords,
1273                    AnnotatedLine &Line)
1274       : Style(Style), Keywords(Keywords), Current(Line.First) {}
1275 
1276   /// \brief Parse expressions with the given operatore precedence.
1277   void parse(int Precedence = 0) {
1278     // Skip 'return' and ObjC selector colons as they are not part of a binary
1279     // expression.
1280     while (Current && (Current->is(tok::kw_return) ||
1281                        (Current->is(tok::colon) &&
1282                         Current->isOneOf(TT_ObjCMethodExpr, TT_DictLiteral))))
1283       next();
1284 
1285     if (!Current || Precedence > PrecedenceArrowAndPeriod)
1286       return;
1287 
1288     // Conditional expressions need to be parsed separately for proper nesting.
1289     if (Precedence == prec::Conditional) {
1290       parseConditionalExpr();
1291       return;
1292     }
1293 
1294     // Parse unary operators, which all have a higher precedence than binary
1295     // operators.
1296     if (Precedence == PrecedenceUnaryOperator) {
1297       parseUnaryOperator();
1298       return;
1299     }
1300 
1301     FormatToken *Start = Current;
1302     FormatToken *LatestOperator = nullptr;
1303     unsigned OperatorIndex = 0;
1304 
1305     while (Current) {
1306       // Consume operators with higher precedence.
1307       parse(Precedence + 1);
1308 
1309       int CurrentPrecedence = getCurrentPrecedence();
1310 
1311       if (Current && Current->is(TT_SelectorName) &&
1312           Precedence == CurrentPrecedence) {
1313         if (LatestOperator)
1314           addFakeParenthesis(Start, prec::Level(Precedence));
1315         Start = Current;
1316       }
1317 
1318       // At the end of the line or when an operator with higher precedence is
1319       // found, insert fake parenthesis and return.
1320       if (!Current || (Current->closesScope() && Current->MatchingParen) ||
1321           (CurrentPrecedence != -1 && CurrentPrecedence < Precedence) ||
1322           (CurrentPrecedence == prec::Conditional &&
1323            Precedence == prec::Assignment && Current->is(tok::colon))) {
1324         break;
1325       }
1326 
1327       // Consume scopes: (), [], <> and {}
1328       if (Current->opensScope()) {
1329         while (Current && !Current->closesScope()) {
1330           next();
1331           parse();
1332         }
1333         next();
1334       } else {
1335         // Operator found.
1336         if (CurrentPrecedence == Precedence) {
1337           LatestOperator = Current;
1338           Current->OperatorIndex = OperatorIndex;
1339           ++OperatorIndex;
1340         }
1341         next(/*SkipPastLeadingComments=*/Precedence > 0);
1342       }
1343     }
1344 
1345     if (LatestOperator && (Current || Precedence > 0)) {
1346       LatestOperator->LastOperator = true;
1347       if (Precedence == PrecedenceArrowAndPeriod) {
1348         // Call expressions don't have a binary operator precedence.
1349         addFakeParenthesis(Start, prec::Unknown);
1350       } else {
1351         addFakeParenthesis(Start, prec::Level(Precedence));
1352       }
1353     }
1354   }
1355 
1356 private:
1357   /// \brief Gets the precedence (+1) of the given token for binary operators
1358   /// and other tokens that we treat like binary operators.
1359   int getCurrentPrecedence() {
1360     if (Current) {
1361       const FormatToken *NextNonComment = Current->getNextNonComment();
1362       if (Current->is(TT_ConditionalExpr))
1363         return prec::Conditional;
1364       if (NextNonComment && NextNonComment->is(tok::colon) &&
1365           NextNonComment->is(TT_DictLiteral))
1366         return prec::Comma;
1367       if (Current->is(TT_LambdaArrow))
1368         return prec::Comma;
1369       if (Current->is(TT_JsFatArrow))
1370         return prec::Assignment;
1371       if (Current->isOneOf(tok::semi, TT_InlineASMColon, TT_SelectorName,
1372                            TT_JsComputedPropertyName) ||
1373           (Current->is(tok::comment) && NextNonComment &&
1374            NextNonComment->is(TT_SelectorName)))
1375         return 0;
1376       if (Current->is(TT_RangeBasedForLoopColon))
1377         return prec::Comma;
1378       if ((Style.Language == FormatStyle::LK_Java ||
1379            Style.Language == FormatStyle::LK_JavaScript) &&
1380           Current->is(Keywords.kw_instanceof))
1381         return prec::Relational;
1382       if (Current->is(TT_BinaryOperator) || Current->is(tok::comma))
1383         return Current->getPrecedence();
1384       if (Current->isOneOf(tok::period, tok::arrow))
1385         return PrecedenceArrowAndPeriod;
1386       if (Style.Language == FormatStyle::LK_Java &&
1387           Current->isOneOf(Keywords.kw_extends, Keywords.kw_implements,
1388                            Keywords.kw_throws))
1389         return 0;
1390     }
1391     return -1;
1392   }
1393 
1394   void addFakeParenthesis(FormatToken *Start, prec::Level Precedence) {
1395     Start->FakeLParens.push_back(Precedence);
1396     if (Precedence > prec::Unknown)
1397       Start->StartsBinaryExpression = true;
1398     if (Current) {
1399       FormatToken *Previous = Current->Previous;
1400       while (Previous->is(tok::comment) && Previous->Previous)
1401         Previous = Previous->Previous;
1402       ++Previous->FakeRParens;
1403       if (Precedence > prec::Unknown)
1404         Previous->EndsBinaryExpression = true;
1405     }
1406   }
1407 
1408   /// \brief Parse unary operator expressions and surround them with fake
1409   /// parentheses if appropriate.
1410   void parseUnaryOperator() {
1411     if (!Current || Current->isNot(TT_UnaryOperator)) {
1412       parse(PrecedenceArrowAndPeriod);
1413       return;
1414     }
1415 
1416     FormatToken *Start = Current;
1417     next();
1418     parseUnaryOperator();
1419 
1420     // The actual precedence doesn't matter.
1421     addFakeParenthesis(Start, prec::Unknown);
1422   }
1423 
1424   void parseConditionalExpr() {
1425     while (Current && Current->isTrailingComment()) {
1426       next();
1427     }
1428     FormatToken *Start = Current;
1429     parse(prec::LogicalOr);
1430     if (!Current || !Current->is(tok::question))
1431       return;
1432     next();
1433     parse(prec::Assignment);
1434     if (!Current || Current->isNot(TT_ConditionalExpr))
1435       return;
1436     next();
1437     parse(prec::Assignment);
1438     addFakeParenthesis(Start, prec::Conditional);
1439   }
1440 
1441   void next(bool SkipPastLeadingComments = true) {
1442     if (Current)
1443       Current = Current->Next;
1444     while (Current &&
1445            (Current->NewlinesBefore == 0 || SkipPastLeadingComments) &&
1446            Current->isTrailingComment())
1447       Current = Current->Next;
1448   }
1449 
1450   const FormatStyle &Style;
1451   const AdditionalKeywords &Keywords;
1452   FormatToken *Current;
1453 };
1454 
1455 } // end anonymous namespace
1456 
1457 void TokenAnnotator::setCommentLineLevels(
1458     SmallVectorImpl<AnnotatedLine *> &Lines) {
1459   const AnnotatedLine *NextNonCommentLine = nullptr;
1460   for (SmallVectorImpl<AnnotatedLine *>::reverse_iterator I = Lines.rbegin(),
1461                                                           E = Lines.rend();
1462        I != E; ++I) {
1463     if (NextNonCommentLine && (*I)->First->is(tok::comment) &&
1464         (*I)->First->Next == nullptr)
1465       (*I)->Level = NextNonCommentLine->Level;
1466     else
1467       NextNonCommentLine = (*I)->First->isNot(tok::r_brace) ? (*I) : nullptr;
1468 
1469     setCommentLineLevels((*I)->Children);
1470   }
1471 }
1472 
1473 void TokenAnnotator::annotate(AnnotatedLine &Line) {
1474   for (SmallVectorImpl<AnnotatedLine *>::iterator I = Line.Children.begin(),
1475                                                   E = Line.Children.end();
1476        I != E; ++I) {
1477     annotate(**I);
1478   }
1479   AnnotatingParser Parser(Style, Line, Keywords);
1480   Line.Type = Parser.parseLine();
1481   if (Line.Type == LT_Invalid)
1482     return;
1483 
1484   ExpressionParser ExprParser(Style, Keywords, Line);
1485   ExprParser.parse();
1486 
1487   if (Line.startsWith(TT_ObjCMethodSpecifier))
1488     Line.Type = LT_ObjCMethodDecl;
1489   else if (Line.startsWith(TT_ObjCDecl))
1490     Line.Type = LT_ObjCDecl;
1491   else if (Line.startsWith(TT_ObjCProperty))
1492     Line.Type = LT_ObjCProperty;
1493 
1494   Line.First->SpacesRequiredBefore = 1;
1495   Line.First->CanBreakBefore = Line.First->MustBreakBefore;
1496 }
1497 
1498 // This function heuristically determines whether 'Current' starts the name of a
1499 // function declaration.
1500 static bool isFunctionDeclarationName(const FormatToken &Current) {
1501   auto skipOperatorName = [](const FormatToken* Next) -> const FormatToken* {
1502     for (; Next; Next = Next->Next) {
1503       if (Next->is(TT_OverloadedOperatorLParen))
1504         return Next;
1505       if (Next->is(TT_OverloadedOperator))
1506         continue;
1507       if (Next->isOneOf(tok::kw_new, tok::kw_delete)) {
1508         // For 'new[]' and 'delete[]'.
1509         if (Next->Next && Next->Next->is(tok::l_square) &&
1510             Next->Next->Next && Next->Next->Next->is(tok::r_square))
1511           Next = Next->Next->Next;
1512         continue;
1513       }
1514 
1515       break;
1516     }
1517     return nullptr;
1518   };
1519 
1520   const FormatToken *Next = Current.Next;
1521   if (Current.is(tok::kw_operator)) {
1522     if (Current.Previous && Current.Previous->is(tok::coloncolon))
1523       return false;
1524     Next = skipOperatorName(Next);
1525   } else {
1526     if (!Current.is(TT_StartOfName) || Current.NestingLevel != 0)
1527       return false;
1528     for (; Next; Next = Next->Next) {
1529       if (Next->is(TT_TemplateOpener)) {
1530         Next = Next->MatchingParen;
1531       } else if (Next->is(tok::coloncolon)) {
1532         Next = Next->Next;
1533         if (!Next)
1534           return false;
1535         if (Next->is(tok::kw_operator)) {
1536           Next = skipOperatorName(Next->Next);
1537           break;
1538         }
1539         if (!Next->is(tok::identifier))
1540           return false;
1541       } else if (Next->is(tok::l_paren)) {
1542         break;
1543       } else {
1544         return false;
1545       }
1546     }
1547   }
1548 
1549   if (!Next || !Next->is(tok::l_paren))
1550     return false;
1551   if (Next->Next == Next->MatchingParen)
1552     return true;
1553   for (const FormatToken *Tok = Next->Next; Tok && Tok != Next->MatchingParen;
1554        Tok = Tok->Next) {
1555     if (Tok->is(tok::kw_const) || Tok->isSimpleTypeSpecifier() ||
1556         Tok->isOneOf(TT_PointerOrReference, TT_StartOfName))
1557       return true;
1558     if (Tok->isOneOf(tok::l_brace, tok::string_literal, TT_ObjCMethodExpr) ||
1559         Tok->Tok.isLiteral())
1560       return false;
1561   }
1562   return false;
1563 }
1564 
1565 void TokenAnnotator::calculateFormattingInformation(AnnotatedLine &Line) {
1566   for (SmallVectorImpl<AnnotatedLine *>::iterator I = Line.Children.begin(),
1567                                                   E = Line.Children.end();
1568        I != E; ++I) {
1569     calculateFormattingInformation(**I);
1570   }
1571 
1572   Line.First->TotalLength =
1573       Line.First->IsMultiline ? Style.ColumnLimit : Line.First->ColumnWidth;
1574   if (!Line.First->Next)
1575     return;
1576   FormatToken *Current = Line.First->Next;
1577   bool InFunctionDecl = Line.MightBeFunctionDecl;
1578   while (Current) {
1579     if (isFunctionDeclarationName(*Current))
1580       Current->Type = TT_FunctionDeclarationName;
1581     if (Current->is(TT_LineComment)) {
1582       if (Current->Previous->BlockKind == BK_BracedInit &&
1583           Current->Previous->opensScope())
1584         Current->SpacesRequiredBefore = Style.Cpp11BracedListStyle ? 0 : 1;
1585       else
1586         Current->SpacesRequiredBefore = Style.SpacesBeforeTrailingComments;
1587 
1588       // If we find a trailing comment, iterate backwards to determine whether
1589       // it seems to relate to a specific parameter. If so, break before that
1590       // parameter to avoid changing the comment's meaning. E.g. don't move 'b'
1591       // to the previous line in:
1592       //   SomeFunction(a,
1593       //                b, // comment
1594       //                c);
1595       if (!Current->HasUnescapedNewline) {
1596         for (FormatToken *Parameter = Current->Previous; Parameter;
1597              Parameter = Parameter->Previous) {
1598           if (Parameter->isOneOf(tok::comment, tok::r_brace))
1599             break;
1600           if (Parameter->Previous && Parameter->Previous->is(tok::comma)) {
1601             if (!Parameter->Previous->is(TT_CtorInitializerComma) &&
1602                 Parameter->HasUnescapedNewline)
1603               Parameter->MustBreakBefore = true;
1604             break;
1605           }
1606         }
1607       }
1608     } else if (Current->SpacesRequiredBefore == 0 &&
1609                spaceRequiredBefore(Line, *Current)) {
1610       Current->SpacesRequiredBefore = 1;
1611     }
1612 
1613     Current->MustBreakBefore =
1614         Current->MustBreakBefore || mustBreakBefore(Line, *Current);
1615 
1616     if ((Style.AlwaysBreakAfterDefinitionReturnType == FormatStyle::DRTBS_All ||
1617          (Style.AlwaysBreakAfterDefinitionReturnType ==
1618               FormatStyle::DRTBS_TopLevel &&
1619           Line.Level == 0)) &&
1620         InFunctionDecl && Current->is(TT_FunctionDeclarationName) &&
1621         !Line.Last->isOneOf(tok::semi, tok::comment)) // Only for definitions.
1622       // FIXME: Line.Last points to other characters than tok::semi
1623       // and tok::lbrace.
1624       Current->MustBreakBefore = true;
1625 
1626     Current->CanBreakBefore =
1627         Current->MustBreakBefore || canBreakBefore(Line, *Current);
1628     unsigned ChildSize = 0;
1629     if (Current->Previous->Children.size() == 1) {
1630       FormatToken &LastOfChild = *Current->Previous->Children[0]->Last;
1631       ChildSize = LastOfChild.isTrailingComment() ? Style.ColumnLimit
1632                                                   : LastOfChild.TotalLength + 1;
1633     }
1634     const FormatToken *Prev = Current->Previous;
1635     if (Current->MustBreakBefore || Prev->Children.size() > 1 ||
1636         (Prev->Children.size() == 1 &&
1637          Prev->Children[0]->First->MustBreakBefore) ||
1638         Current->IsMultiline)
1639       Current->TotalLength = Prev->TotalLength + Style.ColumnLimit;
1640     else
1641       Current->TotalLength = Prev->TotalLength + Current->ColumnWidth +
1642                              ChildSize + Current->SpacesRequiredBefore;
1643 
1644     if (Current->is(TT_CtorInitializerColon))
1645       InFunctionDecl = false;
1646 
1647     // FIXME: Only calculate this if CanBreakBefore is true once static
1648     // initializers etc. are sorted out.
1649     // FIXME: Move magic numbers to a better place.
1650     Current->SplitPenalty = 20 * Current->BindingStrength +
1651                             splitPenalty(Line, *Current, InFunctionDecl);
1652 
1653     Current = Current->Next;
1654   }
1655 
1656   calculateUnbreakableTailLengths(Line);
1657   for (Current = Line.First; Current != nullptr; Current = Current->Next) {
1658     if (Current->Role)
1659       Current->Role->precomputeFormattingInfos(Current);
1660   }
1661 
1662   DEBUG({ printDebugInfo(Line); });
1663 }
1664 
1665 void TokenAnnotator::calculateUnbreakableTailLengths(AnnotatedLine &Line) {
1666   unsigned UnbreakableTailLength = 0;
1667   FormatToken *Current = Line.Last;
1668   while (Current) {
1669     Current->UnbreakableTailLength = UnbreakableTailLength;
1670     if (Current->CanBreakBefore ||
1671         Current->isOneOf(tok::comment, tok::string_literal)) {
1672       UnbreakableTailLength = 0;
1673     } else {
1674       UnbreakableTailLength +=
1675           Current->ColumnWidth + Current->SpacesRequiredBefore;
1676     }
1677     Current = Current->Previous;
1678   }
1679 }
1680 
1681 unsigned TokenAnnotator::splitPenalty(const AnnotatedLine &Line,
1682                                       const FormatToken &Tok,
1683                                       bool InFunctionDecl) {
1684   const FormatToken &Left = *Tok.Previous;
1685   const FormatToken &Right = Tok;
1686 
1687   if (Left.is(tok::semi))
1688     return 0;
1689 
1690   if (Style.Language == FormatStyle::LK_Java) {
1691     if (Right.isOneOf(Keywords.kw_extends, Keywords.kw_throws))
1692       return 1;
1693     if (Right.is(Keywords.kw_implements))
1694       return 2;
1695     if (Left.is(tok::comma) && Left.NestingLevel == 0)
1696       return 3;
1697   } else if (Style.Language == FormatStyle::LK_JavaScript) {
1698     if (Right.is(Keywords.kw_function) && Left.isNot(tok::comma))
1699       return 100;
1700     if (Left.is(TT_JsTypeColon))
1701       return 100;
1702   }
1703 
1704   if (Left.is(tok::comma) || (Right.is(tok::identifier) && Right.Next &&
1705                               Right.Next->is(TT_DictLiteral)))
1706     return 1;
1707   if (Right.is(tok::l_square)) {
1708     if (Style.Language == FormatStyle::LK_Proto)
1709       return 1;
1710     // Slightly prefer formatting local lambda definitions like functions.
1711     if (Right.is(TT_LambdaLSquare) && Left.is(tok::equal))
1712       return 50;
1713     if (!Right.isOneOf(TT_ObjCMethodExpr, TT_LambdaLSquare,
1714                        TT_ArrayInitializerLSquare))
1715       return 500;
1716   }
1717 
1718   if (Right.isOneOf(TT_StartOfName, TT_FunctionDeclarationName) ||
1719       Right.is(tok::kw_operator)) {
1720     if (Line.startsWith(tok::kw_for) && Right.PartOfMultiVariableDeclStmt)
1721       return 3;
1722     if (Left.is(TT_StartOfName))
1723       return 110;
1724     if (InFunctionDecl && Right.NestingLevel == 0)
1725       return Style.PenaltyReturnTypeOnItsOwnLine;
1726     return 200;
1727   }
1728   if (Right.is(TT_PointerOrReference))
1729     return 190;
1730   if (Right.is(TT_LambdaArrow))
1731     return 110;
1732   if (Left.is(tok::equal) && Right.is(tok::l_brace))
1733     return 150;
1734   if (Left.is(TT_CastRParen))
1735     return 100;
1736   if (Left.is(tok::coloncolon) ||
1737       (Right.is(tok::period) && Style.Language == FormatStyle::LK_Proto))
1738     return 500;
1739   if (Left.isOneOf(tok::kw_class, tok::kw_struct))
1740     return 5000;
1741 
1742   if (Left.isOneOf(TT_RangeBasedForLoopColon, TT_InheritanceColon))
1743     return 2;
1744 
1745   if (Right.isMemberAccess()) {
1746     // Breaking before the "./->" of a chained call/member access is reasonably
1747     // cheap, as formatting those with one call per line is generally
1748     // desirable. In particular, it should be cheaper to break before the call
1749     // than it is to break inside a call's parameters, which could lead to weird
1750     // "hanging" indents. The exception is the very last "./->" to support this
1751     // frequent pattern:
1752     //
1753     //   aaaaaaaa.aaaaaaaa.bbbbbbb().ccccccccccccccccccccc(
1754     //       dddddddd);
1755     //
1756     // which might otherwise be blown up onto many lines. Here, clang-format
1757     // won't produce "hanging" indents anyway as there is no other trailing
1758     // call.
1759     return Right.LastOperator ? 150 : 40;
1760   }
1761 
1762   if (Right.is(TT_TrailingAnnotation) &&
1763       (!Right.Next || Right.Next->isNot(tok::l_paren))) {
1764     // Moving trailing annotations to the next line is fine for ObjC method
1765     // declarations.
1766     if (Line.startsWith(TT_ObjCMethodSpecifier))
1767       return 10;
1768     // Generally, breaking before a trailing annotation is bad unless it is
1769     // function-like. It seems to be especially preferable to keep standard
1770     // annotations (i.e. "const", "final" and "override") on the same line.
1771     // Use a slightly higher penalty after ")" so that annotations like
1772     // "const override" are kept together.
1773     bool is_short_annotation = Right.TokenText.size() < 10;
1774     return (Left.is(tok::r_paren) ? 100 : 120) + (is_short_annotation ? 50 : 0);
1775   }
1776 
1777   // In for-loops, prefer breaking at ',' and ';'.
1778   if (Line.startsWith(tok::kw_for) && Left.is(tok::equal))
1779     return 4;
1780 
1781   // In Objective-C method expressions, prefer breaking before "param:" over
1782   // breaking after it.
1783   if (Right.is(TT_SelectorName))
1784     return 0;
1785   if (Left.is(tok::colon) && Left.is(TT_ObjCMethodExpr))
1786     return Line.MightBeFunctionDecl ? 50 : 500;
1787 
1788   if (Left.is(tok::l_paren) && InFunctionDecl &&
1789       Style.AlignAfterOpenBracket != FormatStyle::BAS_DontAlign)
1790     return 100;
1791   if (Left.is(tok::l_paren) && Left.Previous &&
1792       Left.Previous->isOneOf(tok::kw_if, tok::kw_for))
1793     return 1000;
1794   if (Left.is(tok::equal) && InFunctionDecl)
1795     return 110;
1796   if (Right.is(tok::r_brace))
1797     return 1;
1798   if (Left.is(TT_TemplateOpener))
1799     return 100;
1800   if (Left.opensScope()) {
1801     if (Style.AlignAfterOpenBracket == FormatStyle::BAS_DontAlign)
1802       return 0;
1803     return Left.ParameterCount > 1 ? Style.PenaltyBreakBeforeFirstCallParameter
1804                                    : 19;
1805   }
1806   if (Left.is(TT_JavaAnnotation))
1807     return 50;
1808 
1809   if (Right.is(tok::lessless)) {
1810     if (Left.is(tok::string_literal) &&
1811         (!Right.LastOperator || Right.OperatorIndex != 1)) {
1812       StringRef Content = Left.TokenText;
1813       if (Content.startswith("\""))
1814         Content = Content.drop_front(1);
1815       if (Content.endswith("\""))
1816         Content = Content.drop_back(1);
1817       Content = Content.trim();
1818       if (Content.size() > 1 &&
1819           (Content.back() == ':' || Content.back() == '='))
1820         return 25;
1821     }
1822     return 1; // Breaking at a << is really cheap.
1823   }
1824   if (Left.is(TT_ConditionalExpr))
1825     return prec::Conditional;
1826   prec::Level Level = Left.getPrecedence();
1827   if (Level != prec::Unknown)
1828     return Level;
1829   Level = Right.getPrecedence();
1830   if (Level != prec::Unknown)
1831     return Level;
1832 
1833   return 3;
1834 }
1835 
1836 bool TokenAnnotator::spaceRequiredBetween(const AnnotatedLine &Line,
1837                                           const FormatToken &Left,
1838                                           const FormatToken &Right) {
1839   if (Left.is(tok::kw_return) && Right.isNot(tok::semi))
1840     return true;
1841   if (Style.ObjCSpaceAfterProperty && Line.Type == LT_ObjCProperty &&
1842       Left.Tok.getObjCKeywordID() == tok::objc_property)
1843     return true;
1844   if (Right.is(tok::hashhash))
1845     return Left.is(tok::hash);
1846   if (Left.isOneOf(tok::hashhash, tok::hash))
1847     return Right.is(tok::hash);
1848   if (Left.is(tok::l_paren) && Right.is(tok::r_paren))
1849     return Style.SpaceInEmptyParentheses;
1850   if (Left.is(tok::l_paren) || Right.is(tok::r_paren))
1851     return (Right.is(TT_CastRParen) ||
1852             (Left.MatchingParen && Left.MatchingParen->is(TT_CastRParen)))
1853                ? Style.SpacesInCStyleCastParentheses
1854                : Style.SpacesInParentheses;
1855   if (Right.isOneOf(tok::semi, tok::comma))
1856     return false;
1857   if (Right.is(tok::less) &&
1858       (Left.is(tok::kw_template) ||
1859        (Line.Type == LT_ObjCDecl && Style.ObjCSpaceBeforeProtocolList)))
1860     return true;
1861   if (Left.isOneOf(tok::exclaim, tok::tilde))
1862     return false;
1863   if (Left.is(tok::at) &&
1864       Right.isOneOf(tok::identifier, tok::string_literal, tok::char_constant,
1865                     tok::numeric_constant, tok::l_paren, tok::l_brace,
1866                     tok::kw_true, tok::kw_false))
1867     return false;
1868   if (Left.is(tok::coloncolon))
1869     return false;
1870   if (Left.is(tok::less) || Right.isOneOf(tok::greater, tok::less))
1871     return false;
1872   if (Right.is(tok::ellipsis))
1873     return Left.Tok.isLiteral();
1874   if (Left.is(tok::l_square) && Right.is(tok::amp))
1875     return false;
1876   if (Right.is(TT_PointerOrReference))
1877     return (Left.is(tok::r_paren) && Left.MatchingParen &&
1878             (Left.MatchingParen->is(TT_OverloadedOperatorLParen) ||
1879              (Left.MatchingParen->Previous &&
1880               Left.MatchingParen->Previous->is(TT_FunctionDeclarationName)))) ||
1881            (Left.Tok.isLiteral() ||
1882             (!Left.isOneOf(TT_PointerOrReference, tok::l_paren) &&
1883              (Style.PointerAlignment != FormatStyle::PAS_Left ||
1884               Line.IsMultiVariableDeclStmt)));
1885   if (Right.is(TT_FunctionTypeLParen) && Left.isNot(tok::l_paren) &&
1886       (!Left.is(TT_PointerOrReference) ||
1887        (Style.PointerAlignment != FormatStyle::PAS_Right &&
1888         !Line.IsMultiVariableDeclStmt)))
1889     return true;
1890   if (Left.is(TT_PointerOrReference))
1891     return Right.Tok.isLiteral() ||
1892            Right.isOneOf(TT_BlockComment, Keywords.kw_final,
1893                          Keywords.kw_override) ||
1894            (Right.is(tok::l_brace) && Right.BlockKind == BK_Block) ||
1895            (!Right.isOneOf(TT_PointerOrReference, TT_ArraySubscriptLSquare,
1896                            tok::l_paren) &&
1897             (Style.PointerAlignment != FormatStyle::PAS_Right &&
1898              !Line.IsMultiVariableDeclStmt) &&
1899             Left.Previous &&
1900             !Left.Previous->isOneOf(tok::l_paren, tok::coloncolon));
1901   if (Right.is(tok::star) && Left.is(tok::l_paren))
1902     return false;
1903   if (Left.is(tok::l_square))
1904     return (Left.is(TT_ArrayInitializerLSquare) &&
1905             Style.SpacesInContainerLiterals && Right.isNot(tok::r_square)) ||
1906            (Left.is(TT_ArraySubscriptLSquare) && Style.SpacesInSquareBrackets &&
1907             Right.isNot(tok::r_square));
1908   if (Right.is(tok::r_square))
1909     return Right.MatchingParen &&
1910            ((Style.SpacesInContainerLiterals &&
1911              Right.MatchingParen->is(TT_ArrayInitializerLSquare)) ||
1912             (Style.SpacesInSquareBrackets &&
1913              Right.MatchingParen->is(TT_ArraySubscriptLSquare)));
1914   if (Right.is(tok::l_square) &&
1915       !Right.isOneOf(TT_ObjCMethodExpr, TT_LambdaLSquare) &&
1916       !Left.isOneOf(tok::numeric_constant, TT_DictLiteral))
1917     return false;
1918   if (Left.is(tok::colon))
1919     return !Left.is(TT_ObjCMethodExpr);
1920   if (Left.is(tok::l_brace) && Right.is(tok::r_brace))
1921     return !Left.Children.empty(); // No spaces in "{}".
1922   if ((Left.is(tok::l_brace) && Left.BlockKind != BK_Block) ||
1923       (Right.is(tok::r_brace) && Right.MatchingParen &&
1924        Right.MatchingParen->BlockKind != BK_Block))
1925     return !Style.Cpp11BracedListStyle;
1926   if (Left.is(TT_BlockComment))
1927     return !Left.TokenText.endswith("=*/");
1928   if (Right.is(tok::l_paren)) {
1929     if (Left.is(tok::r_paren) && Left.is(TT_AttributeParen))
1930       return true;
1931     return Line.Type == LT_ObjCDecl || Left.is(tok::semi) ||
1932            (Style.SpaceBeforeParens != FormatStyle::SBPO_Never &&
1933             (Left.isOneOf(tok::kw_if, tok::pp_elif, tok::kw_for, tok::kw_while,
1934                           tok::kw_switch, tok::kw_case, TT_ForEachMacro,
1935                           TT_ObjCForIn) ||
1936              (Left.isOneOf(tok::kw_try, Keywords.kw___except, tok::kw_catch,
1937                            tok::kw_new, tok::kw_delete) &&
1938               (!Left.Previous || Left.Previous->isNot(tok::period))))) ||
1939            (Style.SpaceBeforeParens == FormatStyle::SBPO_Always &&
1940             (Left.is(tok::identifier) || Left.isFunctionLikeKeyword() ||
1941              Left.is(tok::r_paren)) &&
1942             Line.Type != LT_PreprocessorDirective);
1943   }
1944   if (Left.is(tok::at) && Right.Tok.getObjCKeywordID() != tok::objc_not_keyword)
1945     return false;
1946   if (Right.is(TT_UnaryOperator))
1947     return !Left.isOneOf(tok::l_paren, tok::l_square, tok::at) &&
1948            (Left.isNot(tok::colon) || Left.isNot(TT_ObjCMethodExpr));
1949   if ((Left.isOneOf(tok::identifier, tok::greater, tok::r_square,
1950                     tok::r_paren) ||
1951        Left.isSimpleTypeSpecifier()) &&
1952       Right.is(tok::l_brace) && Right.getNextNonComment() &&
1953       Right.BlockKind != BK_Block)
1954     return false;
1955   if (Left.is(tok::period) || Right.is(tok::period))
1956     return false;
1957   if (Right.is(tok::hash) && Left.is(tok::identifier) && Left.TokenText == "L")
1958     return false;
1959   if (Left.is(TT_TemplateCloser) && Left.MatchingParen &&
1960       Left.MatchingParen->Previous &&
1961       Left.MatchingParen->Previous->is(tok::period))
1962     // A.<B>DoSomething();
1963     return false;
1964   if (Left.is(TT_TemplateCloser) && Right.is(tok::l_square))
1965     return false;
1966   return true;
1967 }
1968 
1969 bool TokenAnnotator::spaceRequiredBefore(const AnnotatedLine &Line,
1970                                          const FormatToken &Right) {
1971   const FormatToken &Left = *Right.Previous;
1972   if (Right.Tok.getIdentifierInfo() && Left.Tok.getIdentifierInfo())
1973     return true; // Never ever merge two identifiers.
1974   if (Style.Language == FormatStyle::LK_Cpp) {
1975     if (Left.is(tok::kw_operator))
1976       return Right.is(tok::coloncolon);
1977   } else if (Style.Language == FormatStyle::LK_Proto) {
1978     if (Right.is(tok::period) &&
1979         Left.isOneOf(Keywords.kw_optional, Keywords.kw_required,
1980                      Keywords.kw_repeated, Keywords.kw_extend))
1981       return true;
1982     if (Right.is(tok::l_paren) &&
1983         Left.isOneOf(Keywords.kw_returns, Keywords.kw_option))
1984       return true;
1985   } else if (Style.Language == FormatStyle::LK_JavaScript) {
1986     if (Left.isOneOf(Keywords.kw_let, Keywords.kw_var, TT_JsFatArrow,
1987                      Keywords.kw_in))
1988       return true;
1989     if (Right.isOneOf(TT_JsTypeColon, TT_JsTypeOptionalQuestion))
1990       return false;
1991     if ((Left.is(tok::l_brace) || Right.is(tok::r_brace)) &&
1992         Line.First->isOneOf(Keywords.kw_import, tok::kw_export))
1993       return false;
1994     if (Left.is(tok::ellipsis))
1995       return false;
1996     if (Left.is(TT_TemplateCloser) &&
1997         !Right.isOneOf(tok::equal, tok::l_brace, tok::comma, tok::l_square,
1998                        Keywords.kw_implements, Keywords.kw_extends))
1999       // Type assertions ('<type>expr') are not followed by whitespace. Other
2000       // locations that should have whitespace following are identified by the
2001       // above set of follower tokens.
2002       return false;
2003   } else if (Style.Language == FormatStyle::LK_Java) {
2004     if (Left.is(tok::r_square) && Right.is(tok::l_brace))
2005       return true;
2006     if (Left.is(Keywords.kw_synchronized) && Right.is(tok::l_paren))
2007       return Style.SpaceBeforeParens != FormatStyle::SBPO_Never;
2008     if ((Left.isOneOf(tok::kw_static, tok::kw_public, tok::kw_private,
2009                       tok::kw_protected) ||
2010          Left.isOneOf(Keywords.kw_final, Keywords.kw_abstract,
2011                       Keywords.kw_native)) &&
2012         Right.is(TT_TemplateOpener))
2013       return true;
2014   }
2015   if (Left.is(TT_ImplicitStringLiteral))
2016     return Right.WhitespaceRange.getBegin() != Right.WhitespaceRange.getEnd();
2017   if (Line.Type == LT_ObjCMethodDecl) {
2018     if (Left.is(TT_ObjCMethodSpecifier))
2019       return true;
2020     if (Left.is(tok::r_paren) && Right.is(tok::identifier))
2021       // Don't space between ')' and <id>
2022       return false;
2023   }
2024   if (Line.Type == LT_ObjCProperty &&
2025       (Right.is(tok::equal) || Left.is(tok::equal)))
2026     return false;
2027 
2028   if (Right.isOneOf(TT_TrailingReturnArrow, TT_LambdaArrow) ||
2029       Left.isOneOf(TT_TrailingReturnArrow, TT_LambdaArrow))
2030     return true;
2031   if (Left.is(tok::comma))
2032     return true;
2033   if (Right.is(tok::comma))
2034     return false;
2035   if (Right.isOneOf(TT_CtorInitializerColon, TT_ObjCBlockLParen))
2036     return true;
2037   if (Right.is(TT_OverloadedOperatorLParen))
2038     return Style.SpaceBeforeParens == FormatStyle::SBPO_Always;
2039   if (Right.is(tok::colon)) {
2040     if (Line.First->isOneOf(tok::kw_case, tok::kw_default) ||
2041         !Right.getNextNonComment() || Right.getNextNonComment()->is(tok::semi))
2042       return false;
2043     if (Right.is(TT_ObjCMethodExpr))
2044       return false;
2045     if (Left.is(tok::question))
2046       return false;
2047     if (Right.is(TT_InlineASMColon) && Left.is(tok::coloncolon))
2048       return false;
2049     if (Right.is(TT_DictLiteral))
2050       return Style.SpacesInContainerLiterals;
2051     return true;
2052   }
2053   if (Left.is(TT_UnaryOperator))
2054     return Right.is(TT_BinaryOperator);
2055 
2056   // If the next token is a binary operator or a selector name, we have
2057   // incorrectly classified the parenthesis as a cast. FIXME: Detect correctly.
2058   if (Left.is(TT_CastRParen))
2059     return Style.SpaceAfterCStyleCast ||
2060            Right.isOneOf(TT_BinaryOperator, TT_SelectorName);
2061 
2062   if (Left.is(tok::greater) && Right.is(tok::greater))
2063     return Right.is(TT_TemplateCloser) && Left.is(TT_TemplateCloser) &&
2064            (Style.Standard != FormatStyle::LS_Cpp11 || Style.SpacesInAngles);
2065   if (Right.isOneOf(tok::arrow, tok::period, tok::arrowstar, tok::periodstar) ||
2066       Left.isOneOf(tok::arrow, tok::period, tok::arrowstar, tok::periodstar))
2067     return false;
2068   if (!Style.SpaceBeforeAssignmentOperators &&
2069       Right.getPrecedence() == prec::Assignment)
2070     return false;
2071   if (Right.is(tok::coloncolon) && Left.isNot(tok::l_brace))
2072     return (Left.is(TT_TemplateOpener) &&
2073             Style.Standard == FormatStyle::LS_Cpp03) ||
2074            !(Left.isOneOf(tok::identifier, tok::l_paren, tok::r_paren) ||
2075              Left.isOneOf(TT_TemplateCloser, TT_TemplateOpener));
2076   if ((Left.is(TT_TemplateOpener)) != (Right.is(TT_TemplateCloser)))
2077     return Style.SpacesInAngles;
2078   if ((Right.is(TT_BinaryOperator) && !Left.is(tok::l_paren)) ||
2079       (Left.isOneOf(TT_BinaryOperator, TT_ConditionalExpr) &&
2080        !Right.is(tok::r_paren)))
2081     return true;
2082   if (Left.is(TT_TemplateCloser) && Right.is(tok::l_paren) &&
2083       Right.isNot(TT_FunctionTypeLParen))
2084     return Style.SpaceBeforeParens == FormatStyle::SBPO_Always;
2085   if (Right.is(TT_TemplateOpener) && Left.is(tok::r_paren) &&
2086       Left.MatchingParen && Left.MatchingParen->is(TT_OverloadedOperatorLParen))
2087     return false;
2088   if (Right.is(tok::less) && Left.isNot(tok::l_paren) &&
2089       Line.startsWith(tok::hash))
2090     return true;
2091   if (Right.is(TT_TrailingUnaryOperator))
2092     return false;
2093   if (Left.is(TT_RegexLiteral))
2094     return false;
2095   return spaceRequiredBetween(Line, Left, Right);
2096 }
2097 
2098 // Returns 'true' if 'Tok' is a brace we'd want to break before in Allman style.
2099 static bool isAllmanBrace(const FormatToken &Tok) {
2100   return Tok.is(tok::l_brace) && Tok.BlockKind == BK_Block &&
2101          !Tok.isOneOf(TT_ObjCBlockLBrace, TT_DictLiteral);
2102 }
2103 
2104 bool TokenAnnotator::mustBreakBefore(const AnnotatedLine &Line,
2105                                      const FormatToken &Right) {
2106   const FormatToken &Left = *Right.Previous;
2107   if (Right.NewlinesBefore > 1 && Style.MaxEmptyLinesToKeep > 0)
2108     return true;
2109 
2110   if (Style.Language == FormatStyle::LK_JavaScript) {
2111     // FIXME: This might apply to other languages and token kinds.
2112     if (Right.is(tok::char_constant) && Left.is(tok::plus) && Left.Previous &&
2113         Left.Previous->is(tok::char_constant))
2114       return true;
2115     if (Left.is(TT_DictLiteral) && Left.is(tok::l_brace) && Line.Level == 0 &&
2116         Left.Previous && Left.Previous->is(tok::equal) &&
2117         Line.First->isOneOf(tok::identifier, Keywords.kw_import, tok::kw_export,
2118                             tok::kw_const) &&
2119         // kw_var/kw_let are pseudo-tokens that are tok::identifier, so match
2120         // above.
2121         !Line.First->isOneOf(Keywords.kw_var, Keywords.kw_let))
2122       // Object literals on the top level of a file are treated as "enum-style".
2123       // Each key/value pair is put on a separate line, instead of bin-packing.
2124       return true;
2125     if (Left.is(tok::l_brace) && Line.Level == 0 &&
2126         (Line.startsWith(tok::kw_enum) ||
2127          Line.startsWith(tok::kw_export, tok::kw_enum)))
2128       // JavaScript top-level enum key/value pairs are put on separate lines
2129       // instead of bin-packing.
2130       return true;
2131     if (Right.is(tok::r_brace) && Left.is(tok::l_brace) &&
2132         !Left.Children.empty())
2133       // Support AllowShortFunctionsOnASingleLine for JavaScript.
2134       return Style.AllowShortFunctionsOnASingleLine == FormatStyle::SFS_None ||
2135              Style.AllowShortFunctionsOnASingleLine == FormatStyle::SFS_Empty ||
2136              (Left.NestingLevel == 0 && Line.Level == 0 &&
2137               Style.AllowShortFunctionsOnASingleLine ==
2138                   FormatStyle::SFS_Inline);
2139   } else if (Style.Language == FormatStyle::LK_Java) {
2140     if (Right.is(tok::plus) && Left.is(tok::string_literal) && Right.Next &&
2141         Right.Next->is(tok::string_literal))
2142       return true;
2143   }
2144 
2145   // If the last token before a '}' is a comma or a trailing comment, the
2146   // intention is to insert a line break after it in order to make shuffling
2147   // around entries easier.
2148   const FormatToken *BeforeClosingBrace = nullptr;
2149   if (Left.isOneOf(tok::l_brace, TT_ArrayInitializerLSquare) &&
2150       Left.BlockKind != BK_Block && Left.MatchingParen)
2151     BeforeClosingBrace = Left.MatchingParen->Previous;
2152   else if (Right.MatchingParen &&
2153            Right.MatchingParen->isOneOf(tok::l_brace,
2154                                         TT_ArrayInitializerLSquare))
2155     BeforeClosingBrace = &Left;
2156   if (BeforeClosingBrace && (BeforeClosingBrace->is(tok::comma) ||
2157                              BeforeClosingBrace->isTrailingComment()))
2158     return true;
2159 
2160   if (Right.is(tok::comment))
2161     return Left.BlockKind != BK_BracedInit &&
2162            Left.isNot(TT_CtorInitializerColon) &&
2163            (Right.NewlinesBefore > 0 && Right.HasUnescapedNewline);
2164   if (Left.isTrailingComment())
2165     return true;
2166   if (Left.isStringLiteral() &&
2167       (Right.isStringLiteral() || Right.is(TT_ObjCStringLiteral)))
2168     return true;
2169   if (Right.Previous->IsUnterminatedLiteral)
2170     return true;
2171   if (Right.is(tok::lessless) && Right.Next &&
2172       Right.Previous->is(tok::string_literal) &&
2173       Right.Next->is(tok::string_literal))
2174     return true;
2175   if (Right.Previous->ClosesTemplateDeclaration &&
2176       Right.Previous->MatchingParen &&
2177       Right.Previous->MatchingParen->NestingLevel == 0 &&
2178       Style.AlwaysBreakTemplateDeclarations)
2179     return true;
2180   if ((Right.isOneOf(TT_CtorInitializerComma, TT_CtorInitializerColon)) &&
2181       Style.BreakConstructorInitializersBeforeComma &&
2182       !Style.ConstructorInitializerAllOnOneLineOrOnePerLine)
2183     return true;
2184   if (Right.is(tok::string_literal) && Right.TokenText.startswith("R\""))
2185     // Raw string literals are special wrt. line breaks. The author has made a
2186     // deliberate choice and might have aligned the contents of the string
2187     // literal accordingly. Thus, we try keep existing line breaks.
2188     return Right.NewlinesBefore > 0;
2189   if (Right.Previous->is(tok::l_brace) && Right.NestingLevel == 1 &&
2190       Style.Language == FormatStyle::LK_Proto)
2191     // Don't put enums onto single lines in protocol buffers.
2192     return true;
2193   if (Right.is(TT_InlineASMBrace))
2194     return Right.HasUnescapedNewline;
2195   if (isAllmanBrace(Left) || isAllmanBrace(Right))
2196     return (Line.startsWith(tok::kw_enum) && Style.BraceWrapping.AfterEnum) ||
2197            (Line.startsWith(tok::kw_class) && Style.BraceWrapping.AfterClass) ||
2198            (Line.startsWith(tok::kw_struct) && Style.BraceWrapping.AfterStruct);
2199   if (Style.Language == FormatStyle::LK_Proto && Left.isNot(tok::l_brace) &&
2200       Right.is(TT_SelectorName))
2201     return true;
2202   if (Left.is(TT_ObjCBlockLBrace) && !Style.AllowShortBlocksOnASingleLine)
2203     return true;
2204 
2205   if ((Style.Language == FormatStyle::LK_Java ||
2206        Style.Language == FormatStyle::LK_JavaScript) &&
2207       Left.is(TT_LeadingJavaAnnotation) &&
2208       Right.isNot(TT_LeadingJavaAnnotation) && Right.isNot(tok::l_paren) &&
2209       (Line.Last->is(tok::l_brace) || Style.BreakAfterJavaFieldAnnotations))
2210     return true;
2211 
2212   return false;
2213 }
2214 
2215 bool TokenAnnotator::canBreakBefore(const AnnotatedLine &Line,
2216                                     const FormatToken &Right) {
2217   const FormatToken &Left = *Right.Previous;
2218 
2219   // Language-specific stuff.
2220   if (Style.Language == FormatStyle::LK_Java) {
2221     if (Left.isOneOf(Keywords.kw_throws, Keywords.kw_extends,
2222                      Keywords.kw_implements))
2223       return false;
2224     if (Right.isOneOf(Keywords.kw_throws, Keywords.kw_extends,
2225                       Keywords.kw_implements))
2226       return true;
2227   } else if (Style.Language == FormatStyle::LK_JavaScript) {
2228     if (Left.is(TT_JsFatArrow) && Right.is(tok::l_brace))
2229       return false;
2230     if (Left.is(TT_JsTypeColon))
2231       return true;
2232   }
2233 
2234   if (Left.is(tok::at))
2235     return false;
2236   if (Left.Tok.getObjCKeywordID() == tok::objc_interface)
2237     return false;
2238   if (Left.isOneOf(TT_JavaAnnotation, TT_LeadingJavaAnnotation))
2239     return !Right.is(tok::l_paren);
2240   if (Right.is(TT_PointerOrReference))
2241     return Line.IsMultiVariableDeclStmt ||
2242            (Style.PointerAlignment == FormatStyle::PAS_Right &&
2243             (!Right.Next || Right.Next->isNot(TT_FunctionDeclarationName)));
2244   if (Right.isOneOf(TT_StartOfName, TT_FunctionDeclarationName) ||
2245       Right.is(tok::kw_operator))
2246     return true;
2247   if (Left.is(TT_PointerOrReference))
2248     return false;
2249   if (Right.isTrailingComment())
2250     // We rely on MustBreakBefore being set correctly here as we should not
2251     // change the "binding" behavior of a comment.
2252     // The first comment in a braced lists is always interpreted as belonging to
2253     // the first list element. Otherwise, it should be placed outside of the
2254     // list.
2255     return Left.BlockKind == BK_BracedInit;
2256   if (Left.is(tok::question) && Right.is(tok::colon))
2257     return false;
2258   if (Right.is(TT_ConditionalExpr) || Right.is(tok::question))
2259     return Style.BreakBeforeTernaryOperators;
2260   if (Left.is(TT_ConditionalExpr) || Left.is(tok::question))
2261     return !Style.BreakBeforeTernaryOperators;
2262   if (Right.is(TT_InheritanceColon))
2263     return true;
2264   if (Right.is(tok::colon) &&
2265       !Right.isOneOf(TT_CtorInitializerColon, TT_InlineASMColon))
2266     return false;
2267   if (Left.is(tok::colon) && (Left.isOneOf(TT_DictLiteral, TT_ObjCMethodExpr)))
2268     return true;
2269   if (Right.is(TT_SelectorName) || (Right.is(tok::identifier) && Right.Next &&
2270                                     Right.Next->is(TT_ObjCMethodExpr)))
2271     return Left.isNot(tok::period); // FIXME: Properly parse ObjC calls.
2272   if (Left.is(tok::r_paren) && Line.Type == LT_ObjCProperty)
2273     return true;
2274   if (Left.ClosesTemplateDeclaration || Left.is(TT_FunctionAnnotationRParen))
2275     return true;
2276   if (Right.isOneOf(TT_RangeBasedForLoopColon, TT_OverloadedOperatorLParen,
2277                     TT_OverloadedOperator))
2278     return false;
2279   if (Left.is(TT_RangeBasedForLoopColon))
2280     return true;
2281   if (Right.is(TT_RangeBasedForLoopColon))
2282     return false;
2283   if (Left.isOneOf(TT_TemplateCloser, TT_UnaryOperator) ||
2284       Left.is(tok::kw_operator))
2285     return false;
2286   if (Left.is(tok::equal) && !Right.isOneOf(tok::kw_default, tok::kw_delete) &&
2287       Line.Type == LT_VirtualFunctionDecl && Left.NestingLevel == 0)
2288     return false;
2289   if (Left.is(tok::l_paren) && Left.is(TT_AttributeParen))
2290     return false;
2291   if (Left.is(tok::l_paren) && Left.Previous &&
2292       (Left.Previous->isOneOf(TT_BinaryOperator, TT_CastRParen)))
2293     return false;
2294   if (Right.is(TT_ImplicitStringLiteral))
2295     return false;
2296 
2297   if (Right.is(tok::r_paren) || Right.is(TT_TemplateCloser))
2298     return false;
2299   if (Right.is(tok::r_square) && Right.MatchingParen &&
2300       Right.MatchingParen->is(TT_LambdaLSquare))
2301     return false;
2302 
2303   // We only break before r_brace if there was a corresponding break before
2304   // the l_brace, which is tracked by BreakBeforeClosingBrace.
2305   if (Right.is(tok::r_brace))
2306     return Right.MatchingParen && Right.MatchingParen->BlockKind == BK_Block;
2307 
2308   // Allow breaking after a trailing annotation, e.g. after a method
2309   // declaration.
2310   if (Left.is(TT_TrailingAnnotation))
2311     return !Right.isOneOf(tok::l_brace, tok::semi, tok::equal, tok::l_paren,
2312                           tok::less, tok::coloncolon);
2313 
2314   if (Right.is(tok::kw___attribute))
2315     return true;
2316 
2317   if (Left.is(tok::identifier) && Right.is(tok::string_literal))
2318     return true;
2319 
2320   if (Right.is(tok::identifier) && Right.Next && Right.Next->is(TT_DictLiteral))
2321     return true;
2322 
2323   if (Left.is(TT_CtorInitializerComma) &&
2324       Style.BreakConstructorInitializersBeforeComma)
2325     return false;
2326   if (Right.is(TT_CtorInitializerComma) &&
2327       Style.BreakConstructorInitializersBeforeComma)
2328     return true;
2329   if ((Left.is(tok::greater) && Right.is(tok::greater)) ||
2330       (Left.is(tok::less) && Right.is(tok::less)))
2331     return false;
2332   if (Right.is(TT_BinaryOperator) &&
2333       Style.BreakBeforeBinaryOperators != FormatStyle::BOS_None &&
2334       (Style.BreakBeforeBinaryOperators == FormatStyle::BOS_All ||
2335        Right.getPrecedence() != prec::Assignment))
2336     return true;
2337   if (Left.is(TT_ArrayInitializerLSquare))
2338     return true;
2339   if (Right.is(tok::kw_typename) && Left.isNot(tok::kw_const))
2340     return true;
2341   if ((Left.isBinaryOperator() || Left.is(TT_BinaryOperator)) &&
2342       !Left.isOneOf(tok::arrowstar, tok::lessless) &&
2343       Style.BreakBeforeBinaryOperators != FormatStyle::BOS_All &&
2344       (Style.BreakBeforeBinaryOperators == FormatStyle::BOS_None ||
2345        Left.getPrecedence() == prec::Assignment))
2346     return true;
2347   return Left.isOneOf(tok::comma, tok::coloncolon, tok::semi, tok::l_brace,
2348                       tok::kw_class, tok::kw_struct) ||
2349          Right.isMemberAccess() ||
2350          Right.isOneOf(TT_TrailingReturnArrow, TT_LambdaArrow, tok::lessless,
2351                        tok::colon, tok::l_square, tok::at) ||
2352          (Left.is(tok::r_paren) &&
2353           Right.isOneOf(tok::identifier, tok::kw_const)) ||
2354          (Left.is(tok::l_paren) && !Right.is(tok::r_paren));
2355 }
2356 
2357 void TokenAnnotator::printDebugInfo(const AnnotatedLine &Line) {
2358   llvm::errs() << "AnnotatedTokens:\n";
2359   const FormatToken *Tok = Line.First;
2360   while (Tok) {
2361     llvm::errs() << " M=" << Tok->MustBreakBefore
2362                  << " C=" << Tok->CanBreakBefore
2363                  << " T=" << getTokenTypeName(Tok->Type)
2364                  << " S=" << Tok->SpacesRequiredBefore
2365                  << " B=" << Tok->BlockParameterCount
2366                  << " P=" << Tok->SplitPenalty << " Name=" << Tok->Tok.getName()
2367                  << " L=" << Tok->TotalLength << " PPK=" << Tok->PackingKind
2368                  << " FakeLParens=";
2369     for (unsigned i = 0, e = Tok->FakeLParens.size(); i != e; ++i)
2370       llvm::errs() << Tok->FakeLParens[i] << "/";
2371     llvm::errs() << " FakeRParens=" << Tok->FakeRParens << "\n";
2372     if (!Tok->Next)
2373       assert(Tok == Line.Last);
2374     Tok = Tok->Next;
2375   }
2376   llvm::errs() << "----\n";
2377 }
2378 
2379 } // namespace format
2380 } // namespace clang
2381