1 //===--- TokenAnnotator.cpp - Format C++ code -----------------------------===//
2 //
3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4 // See https://llvm.org/LICENSE.txt for license information.
5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6 //
7 //===----------------------------------------------------------------------===//
8 ///
9 /// \file
10 /// This file implements a token annotator, i.e. creates
11 /// \c AnnotatedTokens out of \c FormatTokens with required extra information.
12 ///
13 //===----------------------------------------------------------------------===//
14 
15 #include "TokenAnnotator.h"
16 #include "FormatToken.h"
17 #include "clang/Basic/SourceManager.h"
18 #include "clang/Basic/TokenKinds.h"
19 #include "llvm/ADT/SmallPtrSet.h"
20 #include "llvm/Support/Debug.h"
21 
22 #define DEBUG_TYPE "format-token-annotator"
23 
24 namespace clang {
25 namespace format {
26 
27 namespace {
28 
29 /// Returns \c true if the line starts with a token that can start a statement
30 /// with an initializer.
31 static bool startsWithInitStatement(const AnnotatedLine &Line) {
32   return Line.startsWith(tok::kw_for) || Line.startsWith(tok::kw_if) ||
33          Line.startsWith(tok::kw_switch);
34 }
35 
36 /// Returns \c true if the token can be used as an identifier in
37 /// an Objective-C \c \@selector, \c false otherwise.
38 ///
39 /// Because getFormattingLangOpts() always lexes source code as
40 /// Objective-C++, C++ keywords like \c new and \c delete are
41 /// lexed as tok::kw_*, not tok::identifier, even for Objective-C.
42 ///
43 /// For Objective-C and Objective-C++, both identifiers and keywords
44 /// are valid inside @selector(...) (or a macro which
45 /// invokes @selector(...)). So, we allow treat any identifier or
46 /// keyword as a potential Objective-C selector component.
47 static bool canBeObjCSelectorComponent(const FormatToken &Tok) {
48   return Tok.Tok.getIdentifierInfo() != nullptr;
49 }
50 
51 /// With `Left` being '(', check if we're at either `[...](` or
52 /// `[...]<...>(`, where the [ opens a lambda capture list.
53 static bool isLambdaParameterList(const FormatToken *Left) {
54   // Skip <...> if present.
55   if (Left->Previous && Left->Previous->is(tok::greater) &&
56       Left->Previous->MatchingParen &&
57       Left->Previous->MatchingParen->is(TT_TemplateOpener))
58     Left = Left->Previous->MatchingParen;
59 
60   // Check for `[...]`.
61   return Left->Previous && Left->Previous->is(tok::r_square) &&
62          Left->Previous->MatchingParen &&
63          Left->Previous->MatchingParen->is(TT_LambdaLSquare);
64 }
65 
66 /// Returns \c true if the token is followed by a boolean condition, \c false
67 /// otherwise.
68 static bool isKeywordWithCondition(const FormatToken &Tok) {
69   return Tok.isOneOf(tok::kw_if, tok::kw_for, tok::kw_while, tok::kw_switch,
70                      tok::kw_constexpr, tok::kw_catch);
71 }
72 
73 /// A parser that gathers additional information about tokens.
74 ///
75 /// The \c TokenAnnotator tries to match parenthesis and square brakets and
76 /// store a parenthesis levels. It also tries to resolve matching "<" and ">"
77 /// into template parameter lists.
78 class AnnotatingParser {
79 public:
80   AnnotatingParser(const FormatStyle &Style, AnnotatedLine &Line,
81                    const AdditionalKeywords &Keywords)
82       : Style(Style), Line(Line), CurrentToken(Line.First), AutoFound(false),
83         Keywords(Keywords) {
84     Contexts.push_back(Context(tok::unknown, 1, /*IsExpression=*/false));
85     resetTokenMetadata();
86   }
87 
88 private:
89   bool parseAngle() {
90     if (!CurrentToken || !CurrentToken->Previous)
91       return false;
92     if (NonTemplateLess.count(CurrentToken->Previous))
93       return false;
94 
95     const FormatToken &Previous = *CurrentToken->Previous; // The '<'.
96     if (Previous.Previous) {
97       if (Previous.Previous->Tok.isLiteral())
98         return false;
99       if (Previous.Previous->is(tok::r_paren) && Contexts.size() > 1 &&
100           (!Previous.Previous->MatchingParen ||
101            !Previous.Previous->MatchingParen->is(TT_OverloadedOperatorLParen)))
102         return false;
103     }
104 
105     FormatToken *Left = CurrentToken->Previous;
106     Left->ParentBracket = Contexts.back().ContextKind;
107     ScopedContextCreator ContextCreator(*this, tok::less, 12);
108 
109     // If this angle is in the context of an expression, we need to be more
110     // hesitant to detect it as opening template parameters.
111     bool InExprContext = Contexts.back().IsExpression;
112 
113     Contexts.back().IsExpression = false;
114     // If there's a template keyword before the opening angle bracket, this is a
115     // template parameter, not an argument.
116     Contexts.back().InTemplateArgument =
117         Left->Previous && Left->Previous->isNot(tok::kw_template);
118 
119     if (Style.Language == FormatStyle::LK_Java &&
120         CurrentToken->is(tok::question))
121       next();
122 
123     while (CurrentToken) {
124       if (CurrentToken->is(tok::greater)) {
125         // Try to do a better job at looking for ">>" within the condition of
126         // a statement. Conservatively insert spaces between consecutive ">"
127         // tokens to prevent splitting right bitshift operators and potentially
128         // altering program semantics. This check is overly conservative and
129         // will prevent spaces from being inserted in select nested template
130         // parameter cases, but should not alter program semantics.
131         if (CurrentToken->Next && CurrentToken->Next->is(tok::greater) &&
132             Left->ParentBracket != tok::less &&
133             (isKeywordWithCondition(*Line.First) ||
134              CurrentToken->getStartOfNonWhitespace() ==
135                  CurrentToken->Next->getStartOfNonWhitespace().getLocWithOffset(
136                      -1)))
137           return false;
138         Left->MatchingParen = CurrentToken;
139         CurrentToken->MatchingParen = Left;
140         // In TT_Proto, we must distignuish between:
141         //   map<key, value>
142         //   msg < item: data >
143         //   msg: < item: data >
144         // In TT_TextProto, map<key, value> does not occur.
145         if (Style.Language == FormatStyle::LK_TextProto ||
146             (Style.Language == FormatStyle::LK_Proto && Left->Previous &&
147              Left->Previous->isOneOf(TT_SelectorName, TT_DictLiteral)))
148           CurrentToken->setType(TT_DictLiteral);
149         else
150           CurrentToken->setType(TT_TemplateCloser);
151         next();
152         return true;
153       }
154       if (CurrentToken->is(tok::question) &&
155           Style.Language == FormatStyle::LK_Java) {
156         next();
157         continue;
158       }
159       if (CurrentToken->isOneOf(tok::r_paren, tok::r_square, tok::r_brace) ||
160           (CurrentToken->isOneOf(tok::colon, tok::question) && InExprContext &&
161            !Style.isCSharp() && Style.Language != FormatStyle::LK_Proto &&
162            Style.Language != FormatStyle::LK_TextProto))
163         return false;
164       // If a && or || is found and interpreted as a binary operator, this set
165       // of angles is likely part of something like "a < b && c > d". If the
166       // angles are inside an expression, the ||/&& might also be a binary
167       // operator that was misinterpreted because we are parsing template
168       // parameters.
169       // FIXME: This is getting out of hand, write a decent parser.
170       if (CurrentToken->Previous->isOneOf(tok::pipepipe, tok::ampamp) &&
171           CurrentToken->Previous->is(TT_BinaryOperator) &&
172           Contexts[Contexts.size() - 2].IsExpression &&
173           !Line.startsWith(tok::kw_template))
174         return false;
175       updateParameterCount(Left, CurrentToken);
176       if (Style.Language == FormatStyle::LK_Proto) {
177         if (FormatToken *Previous = CurrentToken->getPreviousNonComment()) {
178           if (CurrentToken->is(tok::colon) ||
179               (CurrentToken->isOneOf(tok::l_brace, tok::less) &&
180                Previous->isNot(tok::colon)))
181             Previous->setType(TT_SelectorName);
182         }
183       }
184       if (!consumeToken())
185         return false;
186     }
187     return false;
188   }
189 
190   bool parseUntouchableParens() {
191     while (CurrentToken) {
192       CurrentToken->Finalized = true;
193       switch (CurrentToken->Tok.getKind()) {
194       case tok::l_paren:
195         next();
196         if (!parseUntouchableParens())
197           return false;
198         continue;
199       case tok::r_paren:
200         next();
201         return true;
202       default:
203         // no-op
204         break;
205       }
206       next();
207     }
208     return false;
209   }
210 
211   bool parseParens(bool LookForDecls = false) {
212     if (!CurrentToken)
213       return false;
214     assert(CurrentToken->Previous && "Unknown previous token");
215     FormatToken &OpeningParen = *CurrentToken->Previous;
216     assert(OpeningParen.is(tok::l_paren));
217     FormatToken *PrevNonComment = OpeningParen.getPreviousNonComment();
218     OpeningParen.ParentBracket = Contexts.back().ContextKind;
219     ScopedContextCreator ContextCreator(*this, tok::l_paren, 1);
220 
221     // FIXME: This is a bit of a hack. Do better.
222     Contexts.back().ColonIsForRangeExpr =
223         Contexts.size() == 2 && Contexts[0].ColonIsForRangeExpr;
224 
225     if (OpeningParen.Previous &&
226         OpeningParen.Previous->is(TT_UntouchableMacroFunc)) {
227       OpeningParen.Finalized = true;
228       return parseUntouchableParens();
229     }
230 
231     bool StartsObjCMethodExpr = false;
232     if (FormatToken *MaybeSel = OpeningParen.Previous) {
233       // @selector( starts a selector.
234       if (MaybeSel->isObjCAtKeyword(tok::objc_selector) && MaybeSel->Previous &&
235           MaybeSel->Previous->is(tok::at))
236         StartsObjCMethodExpr = true;
237     }
238 
239     if (OpeningParen.is(TT_OverloadedOperatorLParen)) {
240       // Find the previous kw_operator token.
241       FormatToken *Prev = &OpeningParen;
242       while (!Prev->is(tok::kw_operator)) {
243         Prev = Prev->Previous;
244         assert(Prev && "Expect a kw_operator prior to the OperatorLParen!");
245       }
246 
247       // If faced with "a.operator*(argument)" or "a->operator*(argument)",
248       // i.e. the operator is called as a member function,
249       // then the argument must be an expression.
250       bool OperatorCalledAsMemberFunction =
251           Prev->Previous && Prev->Previous->isOneOf(tok::period, tok::arrow);
252       Contexts.back().IsExpression = OperatorCalledAsMemberFunction;
253     } else if (Style.isJavaScript() &&
254                (Line.startsWith(Keywords.kw_type, tok::identifier) ||
255                 Line.startsWith(tok::kw_export, Keywords.kw_type,
256                                 tok::identifier))) {
257       // type X = (...);
258       // export type X = (...);
259       Contexts.back().IsExpression = false;
260     } else if (OpeningParen.Previous &&
261                (OpeningParen.Previous->isOneOf(tok::kw_static_assert,
262                                                tok::kw_while, tok::l_paren,
263                                                tok::comma) ||
264                 OpeningParen.Previous->isIf() ||
265                 OpeningParen.Previous->is(TT_BinaryOperator))) {
266       // static_assert, if and while usually contain expressions.
267       Contexts.back().IsExpression = true;
268     } else if (Style.isJavaScript() && OpeningParen.Previous &&
269                (OpeningParen.Previous->is(Keywords.kw_function) ||
270                 (OpeningParen.Previous->endsSequence(tok::identifier,
271                                                      Keywords.kw_function)))) {
272       // function(...) or function f(...)
273       Contexts.back().IsExpression = false;
274     } else if (Style.isJavaScript() && OpeningParen.Previous &&
275                OpeningParen.Previous->is(TT_JsTypeColon)) {
276       // let x: (SomeType);
277       Contexts.back().IsExpression = false;
278     } else if (isLambdaParameterList(&OpeningParen)) {
279       // This is a parameter list of a lambda expression.
280       Contexts.back().IsExpression = false;
281     } else if (Line.InPPDirective &&
282                (!OpeningParen.Previous ||
283                 !OpeningParen.Previous->is(tok::identifier))) {
284       Contexts.back().IsExpression = true;
285     } else if (Contexts[Contexts.size() - 2].CaretFound) {
286       // This is the parameter list of an ObjC block.
287       Contexts.back().IsExpression = false;
288     } else if (OpeningParen.Previous &&
289                OpeningParen.Previous->is(TT_ForEachMacro)) {
290       // The first argument to a foreach macro is a declaration.
291       Contexts.back().IsForEachMacro = true;
292       Contexts.back().IsExpression = false;
293     } else if (OpeningParen.Previous && OpeningParen.Previous->MatchingParen &&
294                OpeningParen.Previous->MatchingParen->is(TT_ObjCBlockLParen)) {
295       Contexts.back().IsExpression = false;
296     } else if (!Line.MustBeDeclaration && !Line.InPPDirective) {
297       bool IsForOrCatch =
298           OpeningParen.Previous &&
299           OpeningParen.Previous->isOneOf(tok::kw_for, tok::kw_catch);
300       Contexts.back().IsExpression = !IsForOrCatch;
301     }
302 
303     // Infer the role of the l_paren based on the previous token if we haven't
304     // detected one one yet.
305     if (PrevNonComment && OpeningParen.is(TT_Unknown)) {
306       if (PrevNonComment->is(tok::kw___attribute)) {
307         OpeningParen.setType(TT_AttributeParen);
308       } else if (PrevNonComment->isOneOf(TT_TypenameMacro, tok::kw_decltype,
309                                          tok::kw_typeof, tok::kw__Atomic,
310                                          tok::kw___underlying_type)) {
311         OpeningParen.setType(TT_TypeDeclarationParen);
312         // decltype() and typeof() usually contain expressions.
313         if (PrevNonComment->isOneOf(tok::kw_decltype, tok::kw_typeof))
314           Contexts.back().IsExpression = true;
315       }
316     }
317 
318     if (StartsObjCMethodExpr) {
319       Contexts.back().ColonIsObjCMethodExpr = true;
320       OpeningParen.setType(TT_ObjCMethodExpr);
321     }
322 
323     // MightBeFunctionType and ProbablyFunctionType are used for
324     // function pointer and reference types as well as Objective-C
325     // block types:
326     //
327     // void (*FunctionPointer)(void);
328     // void (&FunctionReference)(void);
329     // void (&&FunctionReference)(void);
330     // void (^ObjCBlock)(void);
331     bool MightBeFunctionType = !Contexts[Contexts.size() - 2].IsExpression;
332     bool ProbablyFunctionType =
333         CurrentToken->isOneOf(tok::star, tok::amp, tok::ampamp, tok::caret);
334     bool HasMultipleLines = false;
335     bool HasMultipleParametersOnALine = false;
336     bool MightBeObjCForRangeLoop =
337         OpeningParen.Previous && OpeningParen.Previous->is(tok::kw_for);
338     FormatToken *PossibleObjCForInToken = nullptr;
339     while (CurrentToken) {
340       // LookForDecls is set when "if (" has been seen. Check for
341       // 'identifier' '*' 'identifier' followed by not '=' -- this
342       // '*' has to be a binary operator but determineStarAmpUsage() will
343       // categorize it as an unary operator, so set the right type here.
344       if (LookForDecls && CurrentToken->Next) {
345         FormatToken *Prev = CurrentToken->getPreviousNonComment();
346         if (Prev) {
347           FormatToken *PrevPrev = Prev->getPreviousNonComment();
348           FormatToken *Next = CurrentToken->Next;
349           if (PrevPrev && PrevPrev->is(tok::identifier) &&
350               Prev->isOneOf(tok::star, tok::amp, tok::ampamp) &&
351               CurrentToken->is(tok::identifier) && Next->isNot(tok::equal)) {
352             Prev->setType(TT_BinaryOperator);
353             LookForDecls = false;
354           }
355         }
356       }
357 
358       if (CurrentToken->Previous->is(TT_PointerOrReference) &&
359           CurrentToken->Previous->Previous->isOneOf(tok::l_paren,
360                                                     tok::coloncolon))
361         ProbablyFunctionType = true;
362       if (CurrentToken->is(tok::comma))
363         MightBeFunctionType = false;
364       if (CurrentToken->Previous->is(TT_BinaryOperator))
365         Contexts.back().IsExpression = true;
366       if (CurrentToken->is(tok::r_paren)) {
367         if (OpeningParen.isNot(TT_CppCastLParen) && MightBeFunctionType &&
368             ProbablyFunctionType && CurrentToken->Next &&
369             (CurrentToken->Next->is(tok::l_paren) ||
370              (CurrentToken->Next->is(tok::l_square) && Line.MustBeDeclaration)))
371           OpeningParen.setType(OpeningParen.Next->is(tok::caret)
372                                    ? TT_ObjCBlockLParen
373                                    : TT_FunctionTypeLParen);
374         OpeningParen.MatchingParen = CurrentToken;
375         CurrentToken->MatchingParen = &OpeningParen;
376 
377         if (CurrentToken->Next && CurrentToken->Next->is(tok::l_brace) &&
378             OpeningParen.Previous && OpeningParen.Previous->is(tok::l_paren)) {
379           // Detect the case where macros are used to generate lambdas or
380           // function bodies, e.g.:
381           //   auto my_lambda = MACRO((Type *type, int i) { .. body .. });
382           for (FormatToken *Tok = &OpeningParen; Tok != CurrentToken;
383                Tok = Tok->Next)
384             if (Tok->is(TT_BinaryOperator) &&
385                 Tok->isOneOf(tok::star, tok::amp, tok::ampamp))
386               Tok->setType(TT_PointerOrReference);
387         }
388 
389         if (StartsObjCMethodExpr) {
390           CurrentToken->setType(TT_ObjCMethodExpr);
391           if (Contexts.back().FirstObjCSelectorName) {
392             Contexts.back().FirstObjCSelectorName->LongestObjCSelectorName =
393                 Contexts.back().LongestObjCSelectorName;
394           }
395         }
396 
397         if (OpeningParen.is(TT_AttributeParen))
398           CurrentToken->setType(TT_AttributeParen);
399         if (OpeningParen.is(TT_TypeDeclarationParen))
400           CurrentToken->setType(TT_TypeDeclarationParen);
401         if (OpeningParen.Previous &&
402             OpeningParen.Previous->is(TT_JavaAnnotation))
403           CurrentToken->setType(TT_JavaAnnotation);
404         if (OpeningParen.Previous &&
405             OpeningParen.Previous->is(TT_LeadingJavaAnnotation))
406           CurrentToken->setType(TT_LeadingJavaAnnotation);
407         if (OpeningParen.Previous &&
408             OpeningParen.Previous->is(TT_AttributeSquare))
409           CurrentToken->setType(TT_AttributeSquare);
410 
411         if (!HasMultipleLines)
412           OpeningParen.setPackingKind(PPK_Inconclusive);
413         else if (HasMultipleParametersOnALine)
414           OpeningParen.setPackingKind(PPK_BinPacked);
415         else
416           OpeningParen.setPackingKind(PPK_OnePerLine);
417 
418         next();
419         return true;
420       }
421       if (CurrentToken->isOneOf(tok::r_square, tok::r_brace))
422         return false;
423 
424       if (CurrentToken->is(tok::l_brace) && OpeningParen.is(TT_ObjCBlockLParen))
425         OpeningParen.setType(TT_Unknown);
426       if (CurrentToken->is(tok::comma) && CurrentToken->Next &&
427           !CurrentToken->Next->HasUnescapedNewline &&
428           !CurrentToken->Next->isTrailingComment())
429         HasMultipleParametersOnALine = true;
430       bool ProbablyFunctionTypeLParen =
431           (CurrentToken->is(tok::l_paren) && CurrentToken->Next &&
432            CurrentToken->Next->isOneOf(tok::star, tok::amp, tok::caret));
433       if ((CurrentToken->Previous->isOneOf(tok::kw_const, tok::kw_auto) ||
434            CurrentToken->Previous->isSimpleTypeSpecifier()) &&
435           !(CurrentToken->is(tok::l_brace) ||
436             (CurrentToken->is(tok::l_paren) && !ProbablyFunctionTypeLParen)))
437         Contexts.back().IsExpression = false;
438       if (CurrentToken->isOneOf(tok::semi, tok::colon)) {
439         MightBeObjCForRangeLoop = false;
440         if (PossibleObjCForInToken) {
441           PossibleObjCForInToken->setType(TT_Unknown);
442           PossibleObjCForInToken = nullptr;
443         }
444       }
445       if (MightBeObjCForRangeLoop && CurrentToken->is(Keywords.kw_in)) {
446         PossibleObjCForInToken = CurrentToken;
447         PossibleObjCForInToken->setType(TT_ObjCForIn);
448       }
449       // When we discover a 'new', we set CanBeExpression to 'false' in order to
450       // parse the type correctly. Reset that after a comma.
451       if (CurrentToken->is(tok::comma))
452         Contexts.back().CanBeExpression = true;
453 
454       FormatToken *Tok = CurrentToken;
455       if (!consumeToken())
456         return false;
457       updateParameterCount(&OpeningParen, Tok);
458       if (CurrentToken && CurrentToken->HasUnescapedNewline)
459         HasMultipleLines = true;
460     }
461     return false;
462   }
463 
464   bool isCSharpAttributeSpecifier(const FormatToken &Tok) {
465     if (!Style.isCSharp())
466       return false;
467 
468     // `identifier[i]` is not an attribute.
469     if (Tok.Previous && Tok.Previous->is(tok::identifier))
470       return false;
471 
472     // Chains of [] in `identifier[i][j][k]` are not attributes.
473     if (Tok.Previous && Tok.Previous->is(tok::r_square)) {
474       auto *MatchingParen = Tok.Previous->MatchingParen;
475       if (!MatchingParen || MatchingParen->is(TT_ArraySubscriptLSquare))
476         return false;
477     }
478 
479     const FormatToken *AttrTok = Tok.Next;
480     if (!AttrTok)
481       return false;
482 
483     // Just an empty declaration e.g. string [].
484     if (AttrTok->is(tok::r_square))
485       return false;
486 
487     // Move along the tokens inbetween the '[' and ']' e.g. [STAThread].
488     while (AttrTok && AttrTok->isNot(tok::r_square))
489       AttrTok = AttrTok->Next;
490 
491     if (!AttrTok)
492       return false;
493 
494     // Allow an attribute to be the only content of a file.
495     AttrTok = AttrTok->Next;
496     if (!AttrTok)
497       return true;
498 
499     // Limit this to being an access modifier that follows.
500     if (AttrTok->isOneOf(tok::kw_public, tok::kw_private, tok::kw_protected,
501                          tok::comment, tok::kw_class, tok::kw_static,
502                          tok::l_square, Keywords.kw_internal))
503       return true;
504 
505     // incase its a [XXX] retval func(....
506     if (AttrTok->Next &&
507         AttrTok->Next->startsSequence(tok::identifier, tok::l_paren))
508       return true;
509 
510     return false;
511   }
512 
513   bool isCpp11AttributeSpecifier(const FormatToken &Tok) {
514     if (!Style.isCpp() || !Tok.startsSequence(tok::l_square, tok::l_square))
515       return false;
516     // The first square bracket is part of an ObjC array literal
517     if (Tok.Previous && Tok.Previous->is(tok::at))
518       return false;
519     const FormatToken *AttrTok = Tok.Next->Next;
520     if (!AttrTok)
521       return false;
522     // C++17 '[[using ns: foo, bar(baz, blech)]]'
523     // We assume nobody will name an ObjC variable 'using'.
524     if (AttrTok->startsSequence(tok::kw_using, tok::identifier, tok::colon))
525       return true;
526     if (AttrTok->isNot(tok::identifier))
527       return false;
528     while (AttrTok && !AttrTok->startsSequence(tok::r_square, tok::r_square)) {
529       // ObjC message send. We assume nobody will use : in a C++11 attribute
530       // specifier parameter, although this is technically valid:
531       // [[foo(:)]].
532       if (AttrTok->is(tok::colon) ||
533           AttrTok->startsSequence(tok::identifier, tok::identifier) ||
534           AttrTok->startsSequence(tok::r_paren, tok::identifier))
535         return false;
536       if (AttrTok->is(tok::ellipsis))
537         return true;
538       AttrTok = AttrTok->Next;
539     }
540     return AttrTok && AttrTok->startsSequence(tok::r_square, tok::r_square);
541   }
542 
543   bool parseSquare() {
544     if (!CurrentToken)
545       return false;
546 
547     // A '[' could be an index subscript (after an identifier or after
548     // ')' or ']'), it could be the start of an Objective-C method
549     // expression, it could the start of an Objective-C array literal,
550     // or it could be a C++ attribute specifier [[foo::bar]].
551     FormatToken *Left = CurrentToken->Previous;
552     Left->ParentBracket = Contexts.back().ContextKind;
553     FormatToken *Parent = Left->getPreviousNonComment();
554 
555     // Cases where '>' is followed by '['.
556     // In C++, this can happen either in array of templates (foo<int>[10])
557     // or when array is a nested template type (unique_ptr<type1<type2>[]>).
558     bool CppArrayTemplates =
559         Style.isCpp() && Parent && Parent->is(TT_TemplateCloser) &&
560         (Contexts.back().CanBeExpression || Contexts.back().IsExpression ||
561          Contexts.back().InTemplateArgument);
562 
563     bool IsCpp11AttributeSpecifier = isCpp11AttributeSpecifier(*Left) ||
564                                      Contexts.back().InCpp11AttributeSpecifier;
565 
566     // Treat C# Attributes [STAThread] much like C++ attributes [[...]].
567     bool IsCSharpAttributeSpecifier =
568         isCSharpAttributeSpecifier(*Left) ||
569         Contexts.back().InCSharpAttributeSpecifier;
570 
571     bool InsideInlineASM = Line.startsWith(tok::kw_asm);
572     bool IsCppStructuredBinding = Left->isCppStructuredBinding(Style);
573     bool StartsObjCMethodExpr =
574         !IsCppStructuredBinding && !InsideInlineASM && !CppArrayTemplates &&
575         Style.isCpp() && !IsCpp11AttributeSpecifier &&
576         !IsCSharpAttributeSpecifier && Contexts.back().CanBeExpression &&
577         Left->isNot(TT_LambdaLSquare) &&
578         !CurrentToken->isOneOf(tok::l_brace, tok::r_square) &&
579         (!Parent ||
580          Parent->isOneOf(tok::colon, tok::l_square, tok::l_paren,
581                          tok::kw_return, tok::kw_throw) ||
582          Parent->isUnaryOperator() ||
583          // FIXME(bug 36976): ObjC return types shouldn't use TT_CastRParen.
584          Parent->isOneOf(TT_ObjCForIn, TT_CastRParen) ||
585          (getBinOpPrecedence(Parent->Tok.getKind(), true, true) >
586           prec::Unknown));
587     bool ColonFound = false;
588 
589     unsigned BindingIncrease = 1;
590     if (IsCppStructuredBinding) {
591       Left->setType(TT_StructuredBindingLSquare);
592     } else if (Left->is(TT_Unknown)) {
593       if (StartsObjCMethodExpr) {
594         Left->setType(TT_ObjCMethodExpr);
595       } else if (InsideInlineASM) {
596         Left->setType(TT_InlineASMSymbolicNameLSquare);
597       } else if (IsCpp11AttributeSpecifier) {
598         Left->setType(TT_AttributeSquare);
599       } else if (Style.isJavaScript() && Parent &&
600                  Contexts.back().ContextKind == tok::l_brace &&
601                  Parent->isOneOf(tok::l_brace, tok::comma)) {
602         Left->setType(TT_JsComputedPropertyName);
603       } else if (Style.isCpp() && Contexts.back().ContextKind == tok::l_brace &&
604                  Parent && Parent->isOneOf(tok::l_brace, tok::comma)) {
605         Left->setType(TT_DesignatedInitializerLSquare);
606       } else if (IsCSharpAttributeSpecifier) {
607         Left->setType(TT_AttributeSquare);
608       } else if (CurrentToken->is(tok::r_square) && Parent &&
609                  Parent->is(TT_TemplateCloser)) {
610         Left->setType(TT_ArraySubscriptLSquare);
611       } else if (Style.Language == FormatStyle::LK_Proto ||
612                  Style.Language == FormatStyle::LK_TextProto) {
613         // Square braces in LK_Proto can either be message field attributes:
614         //
615         // optional Aaa aaa = 1 [
616         //   (aaa) = aaa
617         // ];
618         //
619         // extensions 123 [
620         //   (aaa) = aaa
621         // ];
622         //
623         // or text proto extensions (in options):
624         //
625         // option (Aaa.options) = {
626         //   [type.type/type] {
627         //     key: value
628         //   }
629         // }
630         //
631         // or repeated fields (in options):
632         //
633         // option (Aaa.options) = {
634         //   keys: [ 1, 2, 3 ]
635         // }
636         //
637         // In the first and the third case we want to spread the contents inside
638         // the square braces; in the second we want to keep them inline.
639         Left->setType(TT_ArrayInitializerLSquare);
640         if (!Left->endsSequence(tok::l_square, tok::numeric_constant,
641                                 tok::equal) &&
642             !Left->endsSequence(tok::l_square, tok::numeric_constant,
643                                 tok::identifier) &&
644             !Left->endsSequence(tok::l_square, tok::colon, TT_SelectorName)) {
645           Left->setType(TT_ProtoExtensionLSquare);
646           BindingIncrease = 10;
647         }
648       } else if (!CppArrayTemplates && Parent &&
649                  Parent->isOneOf(TT_BinaryOperator, TT_TemplateCloser, tok::at,
650                                  tok::comma, tok::l_paren, tok::l_square,
651                                  tok::question, tok::colon, tok::kw_return,
652                                  // Should only be relevant to JavaScript:
653                                  tok::kw_default)) {
654         Left->setType(TT_ArrayInitializerLSquare);
655       } else {
656         BindingIncrease = 10;
657         Left->setType(TT_ArraySubscriptLSquare);
658       }
659     }
660 
661     ScopedContextCreator ContextCreator(*this, tok::l_square, BindingIncrease);
662     Contexts.back().IsExpression = true;
663     if (Style.isJavaScript() && Parent && Parent->is(TT_JsTypeColon))
664       Contexts.back().IsExpression = false;
665 
666     Contexts.back().ColonIsObjCMethodExpr = StartsObjCMethodExpr;
667     Contexts.back().InCpp11AttributeSpecifier = IsCpp11AttributeSpecifier;
668     Contexts.back().InCSharpAttributeSpecifier = IsCSharpAttributeSpecifier;
669 
670     while (CurrentToken) {
671       if (CurrentToken->is(tok::r_square)) {
672         if (IsCpp11AttributeSpecifier)
673           CurrentToken->setType(TT_AttributeSquare);
674         if (IsCSharpAttributeSpecifier)
675           CurrentToken->setType(TT_AttributeSquare);
676         else if (((CurrentToken->Next &&
677                    CurrentToken->Next->is(tok::l_paren)) ||
678                   (CurrentToken->Previous &&
679                    CurrentToken->Previous->Previous == Left)) &&
680                  Left->is(TT_ObjCMethodExpr)) {
681           // An ObjC method call is rarely followed by an open parenthesis. It
682           // also can't be composed of just one token, unless it's a macro that
683           // will be expanded to more tokens.
684           // FIXME: Do we incorrectly label ":" with this?
685           StartsObjCMethodExpr = false;
686           Left->setType(TT_Unknown);
687         }
688         if (StartsObjCMethodExpr && CurrentToken->Previous != Left) {
689           CurrentToken->setType(TT_ObjCMethodExpr);
690           // If we haven't seen a colon yet, make sure the last identifier
691           // before the r_square is tagged as a selector name component.
692           if (!ColonFound && CurrentToken->Previous &&
693               CurrentToken->Previous->is(TT_Unknown) &&
694               canBeObjCSelectorComponent(*CurrentToken->Previous))
695             CurrentToken->Previous->setType(TT_SelectorName);
696           // determineStarAmpUsage() thinks that '*' '[' is allocating an
697           // array of pointers, but if '[' starts a selector then '*' is a
698           // binary operator.
699           if (Parent && Parent->is(TT_PointerOrReference))
700             Parent->overwriteFixedType(TT_BinaryOperator);
701         }
702         // An arrow after an ObjC method expression is not a lambda arrow.
703         if (CurrentToken->getType() == TT_ObjCMethodExpr &&
704             CurrentToken->Next && CurrentToken->Next->is(TT_LambdaArrow))
705           CurrentToken->Next->overwriteFixedType(TT_Unknown);
706         Left->MatchingParen = CurrentToken;
707         CurrentToken->MatchingParen = Left;
708         // FirstObjCSelectorName is set when a colon is found. This does
709         // not work, however, when the method has no parameters.
710         // Here, we set FirstObjCSelectorName when the end of the method call is
711         // reached, in case it was not set already.
712         if (!Contexts.back().FirstObjCSelectorName) {
713           FormatToken *Previous = CurrentToken->getPreviousNonComment();
714           if (Previous && Previous->is(TT_SelectorName)) {
715             Previous->ObjCSelectorNameParts = 1;
716             Contexts.back().FirstObjCSelectorName = Previous;
717           }
718         } else {
719           Left->ParameterCount =
720               Contexts.back().FirstObjCSelectorName->ObjCSelectorNameParts;
721         }
722         if (Contexts.back().FirstObjCSelectorName) {
723           Contexts.back().FirstObjCSelectorName->LongestObjCSelectorName =
724               Contexts.back().LongestObjCSelectorName;
725           if (Left->BlockParameterCount > 1)
726             Contexts.back().FirstObjCSelectorName->LongestObjCSelectorName = 0;
727         }
728         next();
729         return true;
730       }
731       if (CurrentToken->isOneOf(tok::r_paren, tok::r_brace))
732         return false;
733       if (CurrentToken->is(tok::colon)) {
734         if (IsCpp11AttributeSpecifier &&
735             CurrentToken->endsSequence(tok::colon, tok::identifier,
736                                        tok::kw_using)) {
737           // Remember that this is a [[using ns: foo]] C++ attribute, so we
738           // don't add a space before the colon (unlike other colons).
739           CurrentToken->setType(TT_AttributeColon);
740         } else if (Left->isOneOf(TT_ArraySubscriptLSquare,
741                                  TT_DesignatedInitializerLSquare)) {
742           Left->setType(TT_ObjCMethodExpr);
743           StartsObjCMethodExpr = true;
744           Contexts.back().ColonIsObjCMethodExpr = true;
745           if (Parent && Parent->is(tok::r_paren))
746             // FIXME(bug 36976): ObjC return types shouldn't use TT_CastRParen.
747             Parent->setType(TT_CastRParen);
748         }
749         ColonFound = true;
750       }
751       if (CurrentToken->is(tok::comma) && Left->is(TT_ObjCMethodExpr) &&
752           !ColonFound)
753         Left->setType(TT_ArrayInitializerLSquare);
754       FormatToken *Tok = CurrentToken;
755       if (!consumeToken())
756         return false;
757       updateParameterCount(Left, Tok);
758     }
759     return false;
760   }
761 
762   bool couldBeInStructArrayInitializer() const {
763     if (Contexts.size() < 2)
764       return false;
765     // We want to back up no more then 2 context levels i.e.
766     // . { { <-
767     const auto End = std::next(Contexts.rbegin(), 2);
768     auto Last = Contexts.rbegin();
769     unsigned Depth = 0;
770     for (; Last != End; ++Last)
771       if (Last->ContextKind == tok::l_brace)
772         ++Depth;
773     return Depth == 2 && Last->ContextKind != tok::l_brace;
774   }
775 
776   bool parseBrace() {
777     if (!CurrentToken)
778       return true;
779 
780     assert(CurrentToken->Previous);
781     FormatToken &OpeningBrace = *CurrentToken->Previous;
782     assert(OpeningBrace.is(tok::l_brace));
783     OpeningBrace.ParentBracket = Contexts.back().ContextKind;
784 
785     if (Contexts.back().CaretFound)
786       OpeningBrace.overwriteFixedType(TT_ObjCBlockLBrace);
787     Contexts.back().CaretFound = false;
788 
789     ScopedContextCreator ContextCreator(*this, tok::l_brace, 1);
790     Contexts.back().ColonIsDictLiteral = true;
791     if (OpeningBrace.is(BK_BracedInit))
792       Contexts.back().IsExpression = true;
793     if (Style.isJavaScript() && OpeningBrace.Previous &&
794         OpeningBrace.Previous->is(TT_JsTypeColon))
795       Contexts.back().IsExpression = false;
796 
797     unsigned CommaCount = 0;
798     while (CurrentToken) {
799       if (CurrentToken->is(tok::r_brace)) {
800         assert(OpeningBrace.Optional == CurrentToken->Optional);
801         OpeningBrace.MatchingParen = CurrentToken;
802         CurrentToken->MatchingParen = &OpeningBrace;
803         if (Style.AlignArrayOfStructures != FormatStyle::AIAS_None) {
804           if (OpeningBrace.ParentBracket == tok::l_brace &&
805               couldBeInStructArrayInitializer() && CommaCount > 0)
806             Contexts.back().InStructArrayInitializer = true;
807         }
808         next();
809         return true;
810       }
811       if (CurrentToken->isOneOf(tok::r_paren, tok::r_square))
812         return false;
813       updateParameterCount(&OpeningBrace, CurrentToken);
814       if (CurrentToken->isOneOf(tok::colon, tok::l_brace, tok::less)) {
815         FormatToken *Previous = CurrentToken->getPreviousNonComment();
816         if (Previous->is(TT_JsTypeOptionalQuestion))
817           Previous = Previous->getPreviousNonComment();
818         if ((CurrentToken->is(tok::colon) &&
819              (!Contexts.back().ColonIsDictLiteral || !Style.isCpp())) ||
820             Style.Language == FormatStyle::LK_Proto ||
821             Style.Language == FormatStyle::LK_TextProto) {
822           OpeningBrace.setType(TT_DictLiteral);
823           if (Previous->Tok.getIdentifierInfo() ||
824               Previous->is(tok::string_literal))
825             Previous->setType(TT_SelectorName);
826         }
827         if (CurrentToken->is(tok::colon) && OpeningBrace.is(TT_Unknown))
828           OpeningBrace.setType(TT_DictLiteral);
829         else if (Style.isJavaScript())
830           OpeningBrace.overwriteFixedType(TT_DictLiteral);
831       }
832       if (CurrentToken->is(tok::comma)) {
833         if (Style.isJavaScript())
834           OpeningBrace.overwriteFixedType(TT_DictLiteral);
835         ++CommaCount;
836       }
837       if (!consumeToken())
838         return false;
839     }
840     return true;
841   }
842 
843   void updateParameterCount(FormatToken *Left, FormatToken *Current) {
844     // For ObjC methods, the number of parameters is calculated differently as
845     // method declarations have a different structure (the parameters are not
846     // inside a bracket scope).
847     if (Current->is(tok::l_brace) && Current->is(BK_Block))
848       ++Left->BlockParameterCount;
849     if (Current->is(tok::comma)) {
850       ++Left->ParameterCount;
851       if (!Left->Role)
852         Left->Role.reset(new CommaSeparatedList(Style));
853       Left->Role->CommaFound(Current);
854     } else if (Left->ParameterCount == 0 && Current->isNot(tok::comment)) {
855       Left->ParameterCount = 1;
856     }
857   }
858 
859   bool parseConditional() {
860     while (CurrentToken) {
861       if (CurrentToken->is(tok::colon)) {
862         CurrentToken->setType(TT_ConditionalExpr);
863         next();
864         return true;
865       }
866       if (!consumeToken())
867         return false;
868     }
869     return false;
870   }
871 
872   bool parseTemplateDeclaration() {
873     if (CurrentToken && CurrentToken->is(tok::less)) {
874       CurrentToken->setType(TT_TemplateOpener);
875       next();
876       if (!parseAngle())
877         return false;
878       if (CurrentToken)
879         CurrentToken->Previous->ClosesTemplateDeclaration = true;
880       return true;
881     }
882     return false;
883   }
884 
885   bool consumeToken() {
886     FormatToken *Tok = CurrentToken;
887     next();
888     switch (Tok->Tok.getKind()) {
889     case tok::plus:
890     case tok::minus:
891       if (!Tok->Previous && Line.MustBeDeclaration)
892         Tok->setType(TT_ObjCMethodSpecifier);
893       break;
894     case tok::colon:
895       if (!Tok->Previous)
896         return false;
897       // Colons from ?: are handled in parseConditional().
898       if (Style.isJavaScript()) {
899         if (Contexts.back().ColonIsForRangeExpr || // colon in for loop
900             (Contexts.size() == 1 &&               // switch/case labels
901              !Line.First->isOneOf(tok::kw_enum, tok::kw_case)) ||
902             Contexts.back().ContextKind == tok::l_paren ||  // function params
903             Contexts.back().ContextKind == tok::l_square || // array type
904             (!Contexts.back().IsExpression &&
905              Contexts.back().ContextKind == tok::l_brace) || // object type
906             (Contexts.size() == 1 &&
907              Line.MustBeDeclaration)) { // method/property declaration
908           Contexts.back().IsExpression = false;
909           Tok->setType(TT_JsTypeColon);
910           break;
911         }
912       } else if (Style.isCSharp()) {
913         if (Contexts.back().InCSharpAttributeSpecifier) {
914           Tok->setType(TT_AttributeColon);
915           break;
916         }
917         if (Contexts.back().ContextKind == tok::l_paren) {
918           Tok->setType(TT_CSharpNamedArgumentColon);
919           break;
920         }
921       }
922       if (Line.First->isOneOf(Keywords.kw_module, Keywords.kw_import) ||
923           Line.First->startsSequence(tok::kw_export, Keywords.kw_module) ||
924           Line.First->startsSequence(tok::kw_export, Keywords.kw_import)) {
925         Tok->setType(TT_ModulePartitionColon);
926       } else if (Contexts.back().ColonIsDictLiteral ||
927                  Style.Language == FormatStyle::LK_Proto ||
928                  Style.Language == FormatStyle::LK_TextProto) {
929         Tok->setType(TT_DictLiteral);
930         if (Style.Language == FormatStyle::LK_TextProto) {
931           if (FormatToken *Previous = Tok->getPreviousNonComment())
932             Previous->setType(TT_SelectorName);
933         }
934       } else if (Contexts.back().ColonIsObjCMethodExpr ||
935                  Line.startsWith(TT_ObjCMethodSpecifier)) {
936         Tok->setType(TT_ObjCMethodExpr);
937         const FormatToken *BeforePrevious = Tok->Previous->Previous;
938         // Ensure we tag all identifiers in method declarations as
939         // TT_SelectorName.
940         bool UnknownIdentifierInMethodDeclaration =
941             Line.startsWith(TT_ObjCMethodSpecifier) &&
942             Tok->Previous->is(tok::identifier) && Tok->Previous->is(TT_Unknown);
943         if (!BeforePrevious ||
944             // FIXME(bug 36976): ObjC return types shouldn't use TT_CastRParen.
945             !(BeforePrevious->is(TT_CastRParen) ||
946               (BeforePrevious->is(TT_ObjCMethodExpr) &&
947                BeforePrevious->is(tok::colon))) ||
948             BeforePrevious->is(tok::r_square) ||
949             Contexts.back().LongestObjCSelectorName == 0 ||
950             UnknownIdentifierInMethodDeclaration) {
951           Tok->Previous->setType(TT_SelectorName);
952           if (!Contexts.back().FirstObjCSelectorName)
953             Contexts.back().FirstObjCSelectorName = Tok->Previous;
954           else if (Tok->Previous->ColumnWidth >
955                    Contexts.back().LongestObjCSelectorName)
956             Contexts.back().LongestObjCSelectorName =
957                 Tok->Previous->ColumnWidth;
958           Tok->Previous->ParameterIndex =
959               Contexts.back().FirstObjCSelectorName->ObjCSelectorNameParts;
960           ++Contexts.back().FirstObjCSelectorName->ObjCSelectorNameParts;
961         }
962       } else if (Contexts.back().ColonIsForRangeExpr) {
963         Tok->setType(TT_RangeBasedForLoopColon);
964       } else if (CurrentToken && CurrentToken->is(tok::numeric_constant)) {
965         Tok->setType(TT_BitFieldColon);
966       } else if (Contexts.size() == 1 &&
967                  !Line.First->isOneOf(tok::kw_enum, tok::kw_case,
968                                       tok::kw_default)) {
969         FormatToken *Prev = Tok->getPreviousNonComment();
970         if (!Prev)
971           break;
972         if (Prev->isOneOf(tok::r_paren, tok::kw_noexcept))
973           Tok->setType(TT_CtorInitializerColon);
974         else if (Prev->is(tok::kw_try)) {
975           // Member initializer list within function try block.
976           FormatToken *PrevPrev = Prev->getPreviousNonComment();
977           if (!PrevPrev)
978             break;
979           if (PrevPrev && PrevPrev->isOneOf(tok::r_paren, tok::kw_noexcept))
980             Tok->setType(TT_CtorInitializerColon);
981         } else
982           Tok->setType(TT_InheritanceColon);
983       } else if (canBeObjCSelectorComponent(*Tok->Previous) && Tok->Next &&
984                  (Tok->Next->isOneOf(tok::r_paren, tok::comma) ||
985                   (canBeObjCSelectorComponent(*Tok->Next) && Tok->Next->Next &&
986                    Tok->Next->Next->is(tok::colon)))) {
987         // This handles a special macro in ObjC code where selectors including
988         // the colon are passed as macro arguments.
989         Tok->setType(TT_ObjCMethodExpr);
990       } else if (Contexts.back().ContextKind == tok::l_paren) {
991         Tok->setType(TT_InlineASMColon);
992       }
993       break;
994     case tok::pipe:
995     case tok::amp:
996       // | and & in declarations/type expressions represent union and
997       // intersection types, respectively.
998       if (Style.isJavaScript() && !Contexts.back().IsExpression)
999         Tok->setType(TT_JsTypeOperator);
1000       break;
1001     case tok::kw_if:
1002       if (CurrentToken &&
1003           CurrentToken->isOneOf(tok::kw_constexpr, tok::identifier))
1004         next();
1005       LLVM_FALLTHROUGH;
1006     case tok::kw_while:
1007       if (CurrentToken && CurrentToken->is(tok::l_paren)) {
1008         next();
1009         if (!parseParens(/*LookForDecls=*/true))
1010           return false;
1011       }
1012       break;
1013     case tok::kw_for:
1014       if (Style.isJavaScript()) {
1015         // x.for and {for: ...}
1016         if ((Tok->Previous && Tok->Previous->is(tok::period)) ||
1017             (Tok->Next && Tok->Next->is(tok::colon)))
1018           break;
1019         // JS' for await ( ...
1020         if (CurrentToken && CurrentToken->is(Keywords.kw_await))
1021           next();
1022       }
1023       if (Style.isCpp() && CurrentToken && CurrentToken->is(tok::kw_co_await))
1024         next();
1025       Contexts.back().ColonIsForRangeExpr = true;
1026       if (!CurrentToken || CurrentToken->isNot(tok::l_paren))
1027         return false;
1028       next();
1029       if (!parseParens())
1030         return false;
1031       break;
1032     case tok::l_paren:
1033       // When faced with 'operator()()', the kw_operator handler incorrectly
1034       // marks the first l_paren as a OverloadedOperatorLParen. Here, we make
1035       // the first two parens OverloadedOperators and the second l_paren an
1036       // OverloadedOperatorLParen.
1037       if (Tok->Previous && Tok->Previous->is(tok::r_paren) &&
1038           Tok->Previous->MatchingParen &&
1039           Tok->Previous->MatchingParen->is(TT_OverloadedOperatorLParen)) {
1040         Tok->Previous->setType(TT_OverloadedOperator);
1041         Tok->Previous->MatchingParen->setType(TT_OverloadedOperator);
1042         Tok->setType(TT_OverloadedOperatorLParen);
1043       }
1044 
1045       if (!parseParens())
1046         return false;
1047       if (Line.MustBeDeclaration && Contexts.size() == 1 &&
1048           !Contexts.back().IsExpression && !Line.startsWith(TT_ObjCProperty) &&
1049           !Tok->isOneOf(TT_TypeDeclarationParen, TT_RequiresExpressionLParen) &&
1050           (!Tok->Previous || !Tok->Previous->isOneOf(tok::kw___attribute,
1051                                                      TT_LeadingJavaAnnotation)))
1052         Line.MightBeFunctionDecl = true;
1053       break;
1054     case tok::l_square:
1055       if (!parseSquare())
1056         return false;
1057       break;
1058     case tok::l_brace:
1059       if (Style.Language == FormatStyle::LK_TextProto) {
1060         FormatToken *Previous = Tok->getPreviousNonComment();
1061         if (Previous && Previous->getType() != TT_DictLiteral)
1062           Previous->setType(TT_SelectorName);
1063       }
1064       if (!parseBrace())
1065         return false;
1066       break;
1067     case tok::less:
1068       if (parseAngle()) {
1069         Tok->setType(TT_TemplateOpener);
1070         // In TT_Proto, we must distignuish between:
1071         //   map<key, value>
1072         //   msg < item: data >
1073         //   msg: < item: data >
1074         // In TT_TextProto, map<key, value> does not occur.
1075         if (Style.Language == FormatStyle::LK_TextProto ||
1076             (Style.Language == FormatStyle::LK_Proto && Tok->Previous &&
1077              Tok->Previous->isOneOf(TT_SelectorName, TT_DictLiteral))) {
1078           Tok->setType(TT_DictLiteral);
1079           FormatToken *Previous = Tok->getPreviousNonComment();
1080           if (Previous && Previous->getType() != TT_DictLiteral)
1081             Previous->setType(TT_SelectorName);
1082         }
1083       } else {
1084         Tok->setType(TT_BinaryOperator);
1085         NonTemplateLess.insert(Tok);
1086         CurrentToken = Tok;
1087         next();
1088       }
1089       break;
1090     case tok::r_paren:
1091     case tok::r_square:
1092       return false;
1093     case tok::r_brace:
1094       // Lines can start with '}'.
1095       if (Tok->Previous)
1096         return false;
1097       break;
1098     case tok::greater:
1099       if (Style.Language != FormatStyle::LK_TextProto)
1100         Tok->setType(TT_BinaryOperator);
1101       if (Tok->Previous && Tok->Previous->is(TT_TemplateCloser))
1102         Tok->SpacesRequiredBefore = 1;
1103       break;
1104     case tok::kw_operator:
1105       if (Style.Language == FormatStyle::LK_TextProto ||
1106           Style.Language == FormatStyle::LK_Proto)
1107         break;
1108       while (CurrentToken &&
1109              !CurrentToken->isOneOf(tok::l_paren, tok::semi, tok::r_paren)) {
1110         if (CurrentToken->isOneOf(tok::star, tok::amp))
1111           CurrentToken->setType(TT_PointerOrReference);
1112         consumeToken();
1113         if (CurrentToken && CurrentToken->is(tok::comma) &&
1114             CurrentToken->Previous->isNot(tok::kw_operator))
1115           break;
1116         if (CurrentToken && CurrentToken->Previous->isOneOf(
1117                                 TT_BinaryOperator, TT_UnaryOperator, tok::comma,
1118                                 tok::star, tok::arrow, tok::amp, tok::ampamp))
1119           CurrentToken->Previous->setType(TT_OverloadedOperator);
1120       }
1121       if (CurrentToken && CurrentToken->is(tok::l_paren))
1122         CurrentToken->setType(TT_OverloadedOperatorLParen);
1123       if (CurrentToken && CurrentToken->Previous->is(TT_BinaryOperator))
1124         CurrentToken->Previous->setType(TT_OverloadedOperator);
1125       break;
1126     case tok::question:
1127       if (Style.isJavaScript() && Tok->Next &&
1128           Tok->Next->isOneOf(tok::semi, tok::comma, tok::colon, tok::r_paren,
1129                              tok::r_brace)) {
1130         // Question marks before semicolons, colons, etc. indicate optional
1131         // types (fields, parameters), e.g.
1132         //   function(x?: string, y?) {...}
1133         //   class X { y?; }
1134         Tok->setType(TT_JsTypeOptionalQuestion);
1135         break;
1136       }
1137       // Declarations cannot be conditional expressions, this can only be part
1138       // of a type declaration.
1139       if (Line.MustBeDeclaration && !Contexts.back().IsExpression &&
1140           Style.isJavaScript())
1141         break;
1142       if (Style.isCSharp()) {
1143         // `Type?)`, `Type?>`, `Type? name;` and `Type? name =` can only be
1144         // nullable types.
1145         // Line.MustBeDeclaration will be true for `Type? name;`.
1146         if ((!Contexts.back().IsExpression && Line.MustBeDeclaration) ||
1147             (Tok->Next && Tok->Next->isOneOf(tok::r_paren, tok::greater)) ||
1148             (Tok->Next && Tok->Next->is(tok::identifier) && Tok->Next->Next &&
1149              Tok->Next->Next->is(tok::equal))) {
1150           Tok->setType(TT_CSharpNullable);
1151           break;
1152         }
1153       }
1154       parseConditional();
1155       break;
1156     case tok::kw_template:
1157       parseTemplateDeclaration();
1158       break;
1159     case tok::comma:
1160       if (Contexts.back().InCtorInitializer)
1161         Tok->setType(TT_CtorInitializerComma);
1162       else if (Contexts.back().InInheritanceList)
1163         Tok->setType(TT_InheritanceComma);
1164       else if (Contexts.back().FirstStartOfName &&
1165                (Contexts.size() == 1 || startsWithInitStatement(Line))) {
1166         Contexts.back().FirstStartOfName->PartOfMultiVariableDeclStmt = true;
1167         Line.IsMultiVariableDeclStmt = true;
1168       }
1169       if (Contexts.back().IsForEachMacro)
1170         Contexts.back().IsExpression = true;
1171       break;
1172     case tok::identifier:
1173       if (Tok->isOneOf(Keywords.kw___has_include,
1174                        Keywords.kw___has_include_next))
1175         parseHasInclude();
1176       if (Style.isCSharp() && Tok->is(Keywords.kw_where) && Tok->Next &&
1177           Tok->Next->isNot(tok::l_paren)) {
1178         Tok->setType(TT_CSharpGenericTypeConstraint);
1179         parseCSharpGenericTypeConstraint();
1180       }
1181       break;
1182     case tok::arrow:
1183       if (Tok->Previous && Tok->Previous->is(tok::kw_noexcept))
1184         Tok->setType(TT_TrailingReturnArrow);
1185       break;
1186     default:
1187       break;
1188     }
1189     return true;
1190   }
1191 
1192   void parseCSharpGenericTypeConstraint() {
1193     int OpenAngleBracketsCount = 0;
1194     while (CurrentToken) {
1195       if (CurrentToken->is(tok::less)) {
1196         // parseAngle is too greedy and will consume the whole line.
1197         CurrentToken->setType(TT_TemplateOpener);
1198         ++OpenAngleBracketsCount;
1199         next();
1200       } else if (CurrentToken->is(tok::greater)) {
1201         CurrentToken->setType(TT_TemplateCloser);
1202         --OpenAngleBracketsCount;
1203         next();
1204       } else if (CurrentToken->is(tok::comma) && OpenAngleBracketsCount == 0) {
1205         // We allow line breaks after GenericTypeConstraintComma's
1206         // so do not flag commas in Generics as GenericTypeConstraintComma's.
1207         CurrentToken->setType(TT_CSharpGenericTypeConstraintComma);
1208         next();
1209       } else if (CurrentToken->is(Keywords.kw_where)) {
1210         CurrentToken->setType(TT_CSharpGenericTypeConstraint);
1211         next();
1212       } else if (CurrentToken->is(tok::colon)) {
1213         CurrentToken->setType(TT_CSharpGenericTypeConstraintColon);
1214         next();
1215       } else {
1216         next();
1217       }
1218     }
1219   }
1220 
1221   void parseIncludeDirective() {
1222     if (CurrentToken && CurrentToken->is(tok::less)) {
1223       next();
1224       while (CurrentToken) {
1225         // Mark tokens up to the trailing line comments as implicit string
1226         // literals.
1227         if (CurrentToken->isNot(tok::comment) &&
1228             !CurrentToken->TokenText.startswith("//"))
1229           CurrentToken->setType(TT_ImplicitStringLiteral);
1230         next();
1231       }
1232     }
1233   }
1234 
1235   void parseWarningOrError() {
1236     next();
1237     // We still want to format the whitespace left of the first token of the
1238     // warning or error.
1239     next();
1240     while (CurrentToken) {
1241       CurrentToken->setType(TT_ImplicitStringLiteral);
1242       next();
1243     }
1244   }
1245 
1246   void parsePragma() {
1247     next(); // Consume "pragma".
1248     if (CurrentToken &&
1249         CurrentToken->isOneOf(Keywords.kw_mark, Keywords.kw_option)) {
1250       bool IsMark = CurrentToken->is(Keywords.kw_mark);
1251       next(); // Consume "mark".
1252       next(); // Consume first token (so we fix leading whitespace).
1253       while (CurrentToken) {
1254         if (IsMark || CurrentToken->Previous->is(TT_BinaryOperator))
1255           CurrentToken->setType(TT_ImplicitStringLiteral);
1256         next();
1257       }
1258     }
1259   }
1260 
1261   void parseHasInclude() {
1262     if (!CurrentToken || !CurrentToken->is(tok::l_paren))
1263       return;
1264     next(); // '('
1265     parseIncludeDirective();
1266     next(); // ')'
1267   }
1268 
1269   LineType parsePreprocessorDirective() {
1270     bool IsFirstToken = CurrentToken->IsFirst;
1271     LineType Type = LT_PreprocessorDirective;
1272     next();
1273     if (!CurrentToken)
1274       return Type;
1275 
1276     if (Style.isJavaScript() && IsFirstToken) {
1277       // JavaScript files can contain shebang lines of the form:
1278       // #!/usr/bin/env node
1279       // Treat these like C++ #include directives.
1280       while (CurrentToken) {
1281         // Tokens cannot be comments here.
1282         CurrentToken->setType(TT_ImplicitStringLiteral);
1283         next();
1284       }
1285       return LT_ImportStatement;
1286     }
1287 
1288     if (CurrentToken->is(tok::numeric_constant)) {
1289       CurrentToken->SpacesRequiredBefore = 1;
1290       return Type;
1291     }
1292     // Hashes in the middle of a line can lead to any strange token
1293     // sequence.
1294     if (!CurrentToken->Tok.getIdentifierInfo())
1295       return Type;
1296     switch (CurrentToken->Tok.getIdentifierInfo()->getPPKeywordID()) {
1297     case tok::pp_include:
1298     case tok::pp_include_next:
1299     case tok::pp_import:
1300       next();
1301       parseIncludeDirective();
1302       Type = LT_ImportStatement;
1303       break;
1304     case tok::pp_error:
1305     case tok::pp_warning:
1306       parseWarningOrError();
1307       break;
1308     case tok::pp_pragma:
1309       parsePragma();
1310       break;
1311     case tok::pp_if:
1312     case tok::pp_elif:
1313       Contexts.back().IsExpression = true;
1314       next();
1315       parseLine();
1316       break;
1317     default:
1318       break;
1319     }
1320     while (CurrentToken) {
1321       FormatToken *Tok = CurrentToken;
1322       next();
1323       if (Tok->is(tok::l_paren))
1324         parseParens();
1325       else if (Tok->isOneOf(Keywords.kw___has_include,
1326                             Keywords.kw___has_include_next))
1327         parseHasInclude();
1328     }
1329     return Type;
1330   }
1331 
1332 public:
1333   LineType parseLine() {
1334     if (!CurrentToken)
1335       return LT_Invalid;
1336     NonTemplateLess.clear();
1337     if (CurrentToken->is(tok::hash))
1338       return parsePreprocessorDirective();
1339 
1340     // Directly allow to 'import <string-literal>' to support protocol buffer
1341     // definitions (github.com/google/protobuf) or missing "#" (either way we
1342     // should not break the line).
1343     IdentifierInfo *Info = CurrentToken->Tok.getIdentifierInfo();
1344     if ((Style.Language == FormatStyle::LK_Java &&
1345          CurrentToken->is(Keywords.kw_package)) ||
1346         (Info && Info->getPPKeywordID() == tok::pp_import &&
1347          CurrentToken->Next &&
1348          CurrentToken->Next->isOneOf(tok::string_literal, tok::identifier,
1349                                      tok::kw_static))) {
1350       next();
1351       parseIncludeDirective();
1352       return LT_ImportStatement;
1353     }
1354 
1355     // If this line starts and ends in '<' and '>', respectively, it is likely
1356     // part of "#define <a/b.h>".
1357     if (CurrentToken->is(tok::less) && Line.Last->is(tok::greater)) {
1358       parseIncludeDirective();
1359       return LT_ImportStatement;
1360     }
1361 
1362     // In .proto files, top-level options and package statements are very
1363     // similar to import statements and should not be line-wrapped.
1364     if (Style.Language == FormatStyle::LK_Proto && Line.Level == 0 &&
1365         CurrentToken->isOneOf(Keywords.kw_option, Keywords.kw_package)) {
1366       next();
1367       if (CurrentToken && CurrentToken->is(tok::identifier)) {
1368         while (CurrentToken)
1369           next();
1370         return LT_ImportStatement;
1371       }
1372     }
1373 
1374     bool KeywordVirtualFound = false;
1375     bool ImportStatement = false;
1376 
1377     // import {...} from '...';
1378     if (Style.isJavaScript() && CurrentToken->is(Keywords.kw_import))
1379       ImportStatement = true;
1380 
1381     while (CurrentToken) {
1382       if (CurrentToken->is(tok::kw_virtual))
1383         KeywordVirtualFound = true;
1384       if (Style.isJavaScript()) {
1385         // export {...} from '...';
1386         // An export followed by "from 'some string';" is a re-export from
1387         // another module identified by a URI and is treated as a
1388         // LT_ImportStatement (i.e. prevent wraps on it for long URIs).
1389         // Just "export {...};" or "export class ..." should not be treated as
1390         // an import in this sense.
1391         if (Line.First->is(tok::kw_export) &&
1392             CurrentToken->is(Keywords.kw_from) && CurrentToken->Next &&
1393             CurrentToken->Next->isStringLiteral())
1394           ImportStatement = true;
1395         if (isClosureImportStatement(*CurrentToken))
1396           ImportStatement = true;
1397       }
1398       if (!consumeToken())
1399         return LT_Invalid;
1400     }
1401     if (KeywordVirtualFound)
1402       return LT_VirtualFunctionDecl;
1403     if (ImportStatement)
1404       return LT_ImportStatement;
1405 
1406     if (Line.startsWith(TT_ObjCMethodSpecifier)) {
1407       if (Contexts.back().FirstObjCSelectorName)
1408         Contexts.back().FirstObjCSelectorName->LongestObjCSelectorName =
1409             Contexts.back().LongestObjCSelectorName;
1410       return LT_ObjCMethodDecl;
1411     }
1412 
1413     for (const auto &ctx : Contexts)
1414       if (ctx.InStructArrayInitializer)
1415         return LT_ArrayOfStructInitializer;
1416 
1417     return LT_Other;
1418   }
1419 
1420 private:
1421   bool isClosureImportStatement(const FormatToken &Tok) {
1422     // FIXME: Closure-library specific stuff should not be hard-coded but be
1423     // configurable.
1424     return Tok.TokenText == "goog" && Tok.Next && Tok.Next->is(tok::period) &&
1425            Tok.Next->Next &&
1426            (Tok.Next->Next->TokenText == "module" ||
1427             Tok.Next->Next->TokenText == "provide" ||
1428             Tok.Next->Next->TokenText == "require" ||
1429             Tok.Next->Next->TokenText == "requireType" ||
1430             Tok.Next->Next->TokenText == "forwardDeclare") &&
1431            Tok.Next->Next->Next && Tok.Next->Next->Next->is(tok::l_paren);
1432   }
1433 
1434   void resetTokenMetadata() {
1435     if (!CurrentToken)
1436       return;
1437 
1438     // Reset token type in case we have already looked at it and then
1439     // recovered from an error (e.g. failure to find the matching >).
1440     if (!CurrentToken->isTypeFinalized() &&
1441         !CurrentToken->isOneOf(
1442             TT_LambdaLSquare, TT_LambdaLBrace, TT_AttributeMacro, TT_IfMacro,
1443             TT_ForEachMacro, TT_TypenameMacro, TT_FunctionLBrace,
1444             TT_ImplicitStringLiteral, TT_InlineASMBrace, TT_FatArrow,
1445             TT_LambdaArrow, TT_NamespaceMacro, TT_OverloadedOperator,
1446             TT_RegexLiteral, TT_TemplateString, TT_ObjCStringLiteral,
1447             TT_UntouchableMacroFunc, TT_StatementAttributeLikeMacro,
1448             TT_FunctionLikeOrFreestandingMacro, TT_ClassLBrace, TT_EnumLBrace,
1449             TT_RecordLBrace, TT_StructLBrace, TT_UnionLBrace, TT_RequiresClause,
1450             TT_RequiresClauseInARequiresExpression, TT_RequiresExpression,
1451             TT_RequiresExpressionLParen, TT_RequiresExpressionLBrace,
1452             TT_CompoundRequirementLBrace, TT_BracedListLBrace))
1453       CurrentToken->setType(TT_Unknown);
1454     CurrentToken->Role.reset();
1455     CurrentToken->MatchingParen = nullptr;
1456     CurrentToken->FakeLParens.clear();
1457     CurrentToken->FakeRParens = 0;
1458   }
1459 
1460   void next() {
1461     if (!CurrentToken)
1462       return;
1463 
1464     CurrentToken->NestingLevel = Contexts.size() - 1;
1465     CurrentToken->BindingStrength = Contexts.back().BindingStrength;
1466     modifyContext(*CurrentToken);
1467     determineTokenType(*CurrentToken);
1468     CurrentToken = CurrentToken->Next;
1469 
1470     resetTokenMetadata();
1471   }
1472 
1473   /// A struct to hold information valid in a specific context, e.g.
1474   /// a pair of parenthesis.
1475   struct Context {
1476     Context(tok::TokenKind ContextKind, unsigned BindingStrength,
1477             bool IsExpression)
1478         : ContextKind(ContextKind), BindingStrength(BindingStrength),
1479           IsExpression(IsExpression) {}
1480 
1481     tok::TokenKind ContextKind;
1482     unsigned BindingStrength;
1483     bool IsExpression;
1484     unsigned LongestObjCSelectorName = 0;
1485     bool ColonIsForRangeExpr = false;
1486     bool ColonIsDictLiteral = false;
1487     bool ColonIsObjCMethodExpr = false;
1488     FormatToken *FirstObjCSelectorName = nullptr;
1489     FormatToken *FirstStartOfName = nullptr;
1490     bool CanBeExpression = true;
1491     bool InTemplateArgument = false;
1492     bool InCtorInitializer = false;
1493     bool InInheritanceList = false;
1494     bool CaretFound = false;
1495     bool IsForEachMacro = false;
1496     bool InCpp11AttributeSpecifier = false;
1497     bool InCSharpAttributeSpecifier = false;
1498     bool InStructArrayInitializer = false;
1499   };
1500 
1501   /// Puts a new \c Context onto the stack \c Contexts for the lifetime
1502   /// of each instance.
1503   struct ScopedContextCreator {
1504     AnnotatingParser &P;
1505 
1506     ScopedContextCreator(AnnotatingParser &P, tok::TokenKind ContextKind,
1507                          unsigned Increase)
1508         : P(P) {
1509       P.Contexts.push_back(Context(ContextKind,
1510                                    P.Contexts.back().BindingStrength + Increase,
1511                                    P.Contexts.back().IsExpression));
1512     }
1513 
1514     ~ScopedContextCreator() {
1515       if (P.Style.AlignArrayOfStructures != FormatStyle::AIAS_None) {
1516         if (P.Contexts.back().InStructArrayInitializer) {
1517           P.Contexts.pop_back();
1518           P.Contexts.back().InStructArrayInitializer = true;
1519           return;
1520         }
1521       }
1522       P.Contexts.pop_back();
1523     }
1524   };
1525 
1526   void modifyContext(const FormatToken &Current) {
1527     auto AssignmentStartsExpression = [&]() {
1528       if (Current.getPrecedence() != prec::Assignment)
1529         return false;
1530 
1531       if (Line.First->isOneOf(tok::kw_using, tok::kw_return))
1532         return false;
1533       if (Line.First->is(tok::kw_template)) {
1534         assert(Current.Previous);
1535         if (Current.Previous->is(tok::kw_operator)) {
1536           // `template ... operator=` cannot be an expression.
1537           return false;
1538         }
1539 
1540         // `template` keyword can start a variable template.
1541         const FormatToken *Tok = Line.First->getNextNonComment();
1542         assert(Tok); // Current token is on the same line.
1543         if (Tok->isNot(TT_TemplateOpener)) {
1544           // Explicit template instantiations do not have `<>`.
1545           return false;
1546         }
1547 
1548         Tok = Tok->MatchingParen;
1549         if (!Tok)
1550           return false;
1551         Tok = Tok->getNextNonComment();
1552         if (!Tok)
1553           return false;
1554 
1555         if (Tok->isOneOf(tok::kw_class, tok::kw_enum, tok::kw_concept,
1556                          tok::kw_struct, tok::kw_using))
1557           return false;
1558 
1559         return true;
1560       }
1561 
1562       // Type aliases use `type X = ...;` in TypeScript and can be exported
1563       // using `export type ...`.
1564       if (Style.isJavaScript() &&
1565           (Line.startsWith(Keywords.kw_type, tok::identifier) ||
1566            Line.startsWith(tok::kw_export, Keywords.kw_type, tok::identifier)))
1567         return false;
1568 
1569       return !Current.Previous || Current.Previous->isNot(tok::kw_operator);
1570     };
1571 
1572     if (AssignmentStartsExpression()) {
1573       Contexts.back().IsExpression = true;
1574       if (!Line.startsWith(TT_UnaryOperator)) {
1575         for (FormatToken *Previous = Current.Previous;
1576              Previous && Previous->Previous &&
1577              !Previous->Previous->isOneOf(tok::comma, tok::semi);
1578              Previous = Previous->Previous) {
1579           if (Previous->isOneOf(tok::r_square, tok::r_paren)) {
1580             Previous = Previous->MatchingParen;
1581             if (!Previous)
1582               break;
1583           }
1584           if (Previous->opensScope())
1585             break;
1586           if (Previous->isOneOf(TT_BinaryOperator, TT_UnaryOperator) &&
1587               Previous->isOneOf(tok::star, tok::amp, tok::ampamp) &&
1588               Previous->Previous && Previous->Previous->isNot(tok::equal))
1589             Previous->setType(TT_PointerOrReference);
1590         }
1591       }
1592     } else if (Current.is(tok::lessless) &&
1593                (!Current.Previous || !Current.Previous->is(tok::kw_operator))) {
1594       Contexts.back().IsExpression = true;
1595     } else if (Current.isOneOf(tok::kw_return, tok::kw_throw)) {
1596       Contexts.back().IsExpression = true;
1597     } else if (Current.is(TT_TrailingReturnArrow)) {
1598       Contexts.back().IsExpression = false;
1599     } else if (Current.is(TT_LambdaArrow) || Current.is(Keywords.kw_assert)) {
1600       Contexts.back().IsExpression = Style.Language == FormatStyle::LK_Java;
1601     } else if (Current.Previous &&
1602                Current.Previous->is(TT_CtorInitializerColon)) {
1603       Contexts.back().IsExpression = true;
1604       Contexts.back().InCtorInitializer = true;
1605     } else if (Current.Previous && Current.Previous->is(TT_InheritanceColon)) {
1606       Contexts.back().InInheritanceList = true;
1607     } else if (Current.isOneOf(tok::r_paren, tok::greater, tok::comma)) {
1608       for (FormatToken *Previous = Current.Previous;
1609            Previous && Previous->isOneOf(tok::star, tok::amp);
1610            Previous = Previous->Previous)
1611         Previous->setType(TT_PointerOrReference);
1612       if (Line.MustBeDeclaration && !Contexts.front().InCtorInitializer)
1613         Contexts.back().IsExpression = false;
1614     } else if (Current.is(tok::kw_new)) {
1615       Contexts.back().CanBeExpression = false;
1616     } else if (Current.is(tok::semi) ||
1617                (Current.is(tok::exclaim) && Current.Previous &&
1618                 !Current.Previous->is(tok::kw_operator))) {
1619       // This should be the condition or increment in a for-loop.
1620       // But not operator !() (can't use TT_OverloadedOperator here as its not
1621       // been annotated yet).
1622       Contexts.back().IsExpression = true;
1623     }
1624   }
1625 
1626   static FormatToken *untilMatchingParen(FormatToken *Current) {
1627     // Used when `MatchingParen` is not yet established.
1628     int ParenLevel = 0;
1629     while (Current) {
1630       if (Current->is(tok::l_paren))
1631         ++ParenLevel;
1632       if (Current->is(tok::r_paren))
1633         --ParenLevel;
1634       if (ParenLevel < 1)
1635         break;
1636       Current = Current->Next;
1637     }
1638     return Current;
1639   }
1640 
1641   static bool isDeductionGuide(FormatToken &Current) {
1642     // Look for a deduction guide template<T> A(...) -> A<...>;
1643     if (Current.Previous && Current.Previous->is(tok::r_paren) &&
1644         Current.startsSequence(tok::arrow, tok::identifier, tok::less)) {
1645       // Find the TemplateCloser.
1646       FormatToken *TemplateCloser = Current.Next->Next;
1647       int NestingLevel = 0;
1648       while (TemplateCloser) {
1649         // Skip over an expressions in parens  A<(3 < 2)>;
1650         if (TemplateCloser->is(tok::l_paren)) {
1651           // No Matching Paren yet so skip to matching paren
1652           TemplateCloser = untilMatchingParen(TemplateCloser);
1653           if (!TemplateCloser)
1654             break;
1655         }
1656         if (TemplateCloser->is(tok::less))
1657           ++NestingLevel;
1658         if (TemplateCloser->is(tok::greater))
1659           --NestingLevel;
1660         if (NestingLevel < 1)
1661           break;
1662         TemplateCloser = TemplateCloser->Next;
1663       }
1664       // Assuming we have found the end of the template ensure its followed
1665       // with a semi-colon.
1666       if (TemplateCloser && TemplateCloser->Next &&
1667           TemplateCloser->Next->is(tok::semi) &&
1668           Current.Previous->MatchingParen) {
1669         // Determine if the identifier `A` prior to the A<..>; is the same as
1670         // prior to the A(..)
1671         FormatToken *LeadingIdentifier =
1672             Current.Previous->MatchingParen->Previous;
1673 
1674         // Differentiate a deduction guide by seeing the
1675         // > of the template prior to the leading identifier.
1676         if (LeadingIdentifier) {
1677           FormatToken *PriorLeadingIdentifier = LeadingIdentifier->Previous;
1678           // Skip back past explicit decoration
1679           if (PriorLeadingIdentifier &&
1680               PriorLeadingIdentifier->is(tok::kw_explicit))
1681             PriorLeadingIdentifier = PriorLeadingIdentifier->Previous;
1682 
1683           return PriorLeadingIdentifier &&
1684                  (PriorLeadingIdentifier->is(TT_TemplateCloser) ||
1685                   PriorLeadingIdentifier->ClosesRequiresClause) &&
1686                  LeadingIdentifier->TokenText == Current.Next->TokenText;
1687         }
1688       }
1689     }
1690     return false;
1691   }
1692 
1693   void determineTokenType(FormatToken &Current) {
1694     if (!Current.is(TT_Unknown))
1695       // The token type is already known.
1696       return;
1697 
1698     if ((Style.isJavaScript() || Style.isCSharp()) &&
1699         Current.is(tok::exclaim)) {
1700       if (Current.Previous) {
1701         bool IsIdentifier =
1702             Style.isJavaScript()
1703                 ? Keywords.IsJavaScriptIdentifier(
1704                       *Current.Previous, /* AcceptIdentifierName= */ true)
1705                 : Current.Previous->is(tok::identifier);
1706         if (IsIdentifier ||
1707             Current.Previous->isOneOf(
1708                 tok::kw_default, tok::kw_namespace, tok::r_paren, tok::r_square,
1709                 tok::r_brace, tok::kw_false, tok::kw_true, Keywords.kw_type,
1710                 Keywords.kw_get, Keywords.kw_init, Keywords.kw_set) ||
1711             Current.Previous->Tok.isLiteral()) {
1712           Current.setType(TT_NonNullAssertion);
1713           return;
1714         }
1715       }
1716       if (Current.Next &&
1717           Current.Next->isOneOf(TT_BinaryOperator, Keywords.kw_as)) {
1718         Current.setType(TT_NonNullAssertion);
1719         return;
1720       }
1721     }
1722 
1723     // Line.MightBeFunctionDecl can only be true after the parentheses of a
1724     // function declaration have been found. In this case, 'Current' is a
1725     // trailing token of this declaration and thus cannot be a name.
1726     if (Current.is(Keywords.kw_instanceof)) {
1727       Current.setType(TT_BinaryOperator);
1728     } else if (isStartOfName(Current) &&
1729                (!Line.MightBeFunctionDecl || Current.NestingLevel != 0)) {
1730       Contexts.back().FirstStartOfName = &Current;
1731       Current.setType(TT_StartOfName);
1732     } else if (Current.is(tok::semi)) {
1733       // Reset FirstStartOfName after finding a semicolon so that a for loop
1734       // with multiple increment statements is not confused with a for loop
1735       // having multiple variable declarations.
1736       Contexts.back().FirstStartOfName = nullptr;
1737     } else if (Current.isOneOf(tok::kw_auto, tok::kw___auto_type)) {
1738       AutoFound = true;
1739     } else if (Current.is(tok::arrow) &&
1740                Style.Language == FormatStyle::LK_Java) {
1741       Current.setType(TT_LambdaArrow);
1742     } else if (Current.is(tok::arrow) && AutoFound && Line.MustBeDeclaration &&
1743                Current.NestingLevel == 0 &&
1744                !Current.Previous->isOneOf(tok::kw_operator, tok::identifier)) {
1745       // not auto operator->() -> xxx;
1746       Current.setType(TT_TrailingReturnArrow);
1747     } else if (Current.is(tok::arrow) && Current.Previous &&
1748                Current.Previous->is(tok::r_brace)) {
1749       // Concept implicit conversion constraint needs to be treated like
1750       // a trailing return type  ... } -> <type>.
1751       Current.setType(TT_TrailingReturnArrow);
1752     } else if (isDeductionGuide(Current)) {
1753       // Deduction guides trailing arrow " A(...) -> A<T>;".
1754       Current.setType(TT_TrailingReturnArrow);
1755     } else if (Current.isOneOf(tok::star, tok::amp, tok::ampamp)) {
1756       Current.setType(determineStarAmpUsage(
1757           Current,
1758           Contexts.back().CanBeExpression && Contexts.back().IsExpression,
1759           Contexts.back().InTemplateArgument));
1760     } else if (Current.isOneOf(tok::minus, tok::plus, tok::caret)) {
1761       Current.setType(determinePlusMinusCaretUsage(Current));
1762       if (Current.is(TT_UnaryOperator) && Current.is(tok::caret))
1763         Contexts.back().CaretFound = true;
1764     } else if (Current.isOneOf(tok::minusminus, tok::plusplus)) {
1765       Current.setType(determineIncrementUsage(Current));
1766     } else if (Current.isOneOf(tok::exclaim, tok::tilde)) {
1767       Current.setType(TT_UnaryOperator);
1768     } else if (Current.is(tok::question)) {
1769       if (Style.isJavaScript() && Line.MustBeDeclaration &&
1770           !Contexts.back().IsExpression) {
1771         // In JavaScript, `interface X { foo?(): bar; }` is an optional method
1772         // on the interface, not a ternary expression.
1773         Current.setType(TT_JsTypeOptionalQuestion);
1774       } else {
1775         Current.setType(TT_ConditionalExpr);
1776       }
1777     } else if (Current.isBinaryOperator() &&
1778                (!Current.Previous || Current.Previous->isNot(tok::l_square)) &&
1779                (!Current.is(tok::greater) &&
1780                 Style.Language != FormatStyle::LK_TextProto)) {
1781       Current.setType(TT_BinaryOperator);
1782     } else if (Current.is(tok::comment)) {
1783       if (Current.TokenText.startswith("/*"))
1784         if (Current.TokenText.endswith("*/"))
1785           Current.setType(TT_BlockComment);
1786         else
1787           // The lexer has for some reason determined a comment here. But we
1788           // cannot really handle it, if it isn't properly terminated.
1789           Current.Tok.setKind(tok::unknown);
1790       else
1791         Current.setType(TT_LineComment);
1792     } else if (Current.is(tok::l_paren)) {
1793       if (lParenStartsCppCast(Current))
1794         Current.setType(TT_CppCastLParen);
1795     } else if (Current.is(tok::r_paren)) {
1796       if (rParenEndsCast(Current))
1797         Current.setType(TT_CastRParen);
1798       if (Current.MatchingParen && Current.Next &&
1799           !Current.Next->isBinaryOperator() &&
1800           !Current.Next->isOneOf(tok::semi, tok::colon, tok::l_brace,
1801                                  tok::comma, tok::period, tok::arrow,
1802                                  tok::coloncolon))
1803         if (FormatToken *AfterParen = Current.MatchingParen->Next) {
1804           // Make sure this isn't the return type of an Obj-C block declaration
1805           if (AfterParen->isNot(tok::caret)) {
1806             if (FormatToken *BeforeParen = Current.MatchingParen->Previous)
1807               if (BeforeParen->is(tok::identifier) &&
1808                   !BeforeParen->is(TT_TypenameMacro) &&
1809                   BeforeParen->TokenText == BeforeParen->TokenText.upper() &&
1810                   (!BeforeParen->Previous ||
1811                    BeforeParen->Previous->ClosesTemplateDeclaration))
1812                 Current.setType(TT_FunctionAnnotationRParen);
1813           }
1814         }
1815     } else if (Current.is(tok::at) && Current.Next && !Style.isJavaScript() &&
1816                Style.Language != FormatStyle::LK_Java) {
1817       // In Java & JavaScript, "@..." is a decorator or annotation. In ObjC, it
1818       // marks declarations and properties that need special formatting.
1819       switch (Current.Next->Tok.getObjCKeywordID()) {
1820       case tok::objc_interface:
1821       case tok::objc_implementation:
1822       case tok::objc_protocol:
1823         Current.setType(TT_ObjCDecl);
1824         break;
1825       case tok::objc_property:
1826         Current.setType(TT_ObjCProperty);
1827         break;
1828       default:
1829         break;
1830       }
1831     } else if (Current.is(tok::period)) {
1832       FormatToken *PreviousNoComment = Current.getPreviousNonComment();
1833       if (PreviousNoComment &&
1834           PreviousNoComment->isOneOf(tok::comma, tok::l_brace))
1835         Current.setType(TT_DesignatedInitializerPeriod);
1836       else if (Style.Language == FormatStyle::LK_Java && Current.Previous &&
1837                Current.Previous->isOneOf(TT_JavaAnnotation,
1838                                          TT_LeadingJavaAnnotation))
1839         Current.setType(Current.Previous->getType());
1840     } else if (canBeObjCSelectorComponent(Current) &&
1841                // FIXME(bug 36976): ObjC return types shouldn't use
1842                // TT_CastRParen.
1843                Current.Previous && Current.Previous->is(TT_CastRParen) &&
1844                Current.Previous->MatchingParen &&
1845                Current.Previous->MatchingParen->Previous &&
1846                Current.Previous->MatchingParen->Previous->is(
1847                    TT_ObjCMethodSpecifier)) {
1848       // This is the first part of an Objective-C selector name. (If there's no
1849       // colon after this, this is the only place which annotates the identifier
1850       // as a selector.)
1851       Current.setType(TT_SelectorName);
1852     } else if (Current.isOneOf(tok::identifier, tok::kw_const, tok::kw_noexcept,
1853                                tok::kw_requires) &&
1854                Current.Previous &&
1855                !Current.Previous->isOneOf(tok::equal, tok::at) &&
1856                Line.MightBeFunctionDecl && Contexts.size() == 1) {
1857       // Line.MightBeFunctionDecl can only be true after the parentheses of a
1858       // function declaration have been found.
1859       Current.setType(TT_TrailingAnnotation);
1860     } else if ((Style.Language == FormatStyle::LK_Java ||
1861                 Style.isJavaScript()) &&
1862                Current.Previous) {
1863       if (Current.Previous->is(tok::at) &&
1864           Current.isNot(Keywords.kw_interface)) {
1865         const FormatToken &AtToken = *Current.Previous;
1866         const FormatToken *Previous = AtToken.getPreviousNonComment();
1867         if (!Previous || Previous->is(TT_LeadingJavaAnnotation))
1868           Current.setType(TT_LeadingJavaAnnotation);
1869         else
1870           Current.setType(TT_JavaAnnotation);
1871       } else if (Current.Previous->is(tok::period) &&
1872                  Current.Previous->isOneOf(TT_JavaAnnotation,
1873                                            TT_LeadingJavaAnnotation)) {
1874         Current.setType(Current.Previous->getType());
1875       }
1876     }
1877   }
1878 
1879   /// Take a guess at whether \p Tok starts a name of a function or
1880   /// variable declaration.
1881   ///
1882   /// This is a heuristic based on whether \p Tok is an identifier following
1883   /// something that is likely a type.
1884   bool isStartOfName(const FormatToken &Tok) {
1885     if (Tok.isNot(tok::identifier) || !Tok.Previous)
1886       return false;
1887 
1888     if (Tok.Previous->isOneOf(TT_LeadingJavaAnnotation, Keywords.kw_instanceof,
1889                               Keywords.kw_as))
1890       return false;
1891     if (Style.isJavaScript() && Tok.Previous->is(Keywords.kw_in))
1892       return false;
1893 
1894     // Skip "const" as it does not have an influence on whether this is a name.
1895     FormatToken *PreviousNotConst = Tok.getPreviousNonComment();
1896 
1897     // For javascript const can be like "let" or "var"
1898     if (!Style.isJavaScript())
1899       while (PreviousNotConst && PreviousNotConst->is(tok::kw_const))
1900         PreviousNotConst = PreviousNotConst->getPreviousNonComment();
1901 
1902     if (!PreviousNotConst)
1903       return false;
1904 
1905     if (PreviousNotConst->ClosesRequiresClause)
1906       return false;
1907 
1908     bool IsPPKeyword = PreviousNotConst->is(tok::identifier) &&
1909                        PreviousNotConst->Previous &&
1910                        PreviousNotConst->Previous->is(tok::hash);
1911 
1912     if (PreviousNotConst->is(TT_TemplateCloser))
1913       return PreviousNotConst && PreviousNotConst->MatchingParen &&
1914              PreviousNotConst->MatchingParen->Previous &&
1915              PreviousNotConst->MatchingParen->Previous->isNot(tok::period) &&
1916              PreviousNotConst->MatchingParen->Previous->isNot(tok::kw_template);
1917 
1918     if (PreviousNotConst->is(tok::r_paren) &&
1919         PreviousNotConst->is(TT_TypeDeclarationParen))
1920       return true;
1921 
1922     // If is a preprocess keyword like #define.
1923     if (IsPPKeyword)
1924       return false;
1925 
1926     // int a or auto a.
1927     if (PreviousNotConst->isOneOf(tok::identifier, tok::kw_auto))
1928       return true;
1929 
1930     // *a or &a or &&a.
1931     if (PreviousNotConst->is(TT_PointerOrReference))
1932       return true;
1933 
1934     // MyClass a;
1935     if (PreviousNotConst->isSimpleTypeSpecifier())
1936       return true;
1937 
1938     // const a = in JavaScript.
1939     return Style.isJavaScript() && PreviousNotConst->is(tok::kw_const);
1940   }
1941 
1942   /// Determine whether '(' is starting a C++ cast.
1943   bool lParenStartsCppCast(const FormatToken &Tok) {
1944     // C-style casts are only used in C++.
1945     if (!Style.isCpp())
1946       return false;
1947 
1948     FormatToken *LeftOfParens = Tok.getPreviousNonComment();
1949     if (LeftOfParens && LeftOfParens->is(TT_TemplateCloser) &&
1950         LeftOfParens->MatchingParen) {
1951       auto *Prev = LeftOfParens->MatchingParen->getPreviousNonComment();
1952       if (Prev && Prev->isOneOf(tok::kw_const_cast, tok::kw_dynamic_cast,
1953                                 tok::kw_reinterpret_cast, tok::kw_static_cast))
1954         // FIXME: Maybe we should handle identifiers ending with "_cast",
1955         // e.g. any_cast?
1956         return true;
1957     }
1958     return false;
1959   }
1960 
1961   /// Determine whether ')' is ending a cast.
1962   bool rParenEndsCast(const FormatToken &Tok) {
1963     // C-style casts are only used in C++, C# and Java.
1964     if (!Style.isCSharp() && !Style.isCpp() &&
1965         Style.Language != FormatStyle::LK_Java)
1966       return false;
1967 
1968     // Empty parens aren't casts and there are no casts at the end of the line.
1969     if (Tok.Previous == Tok.MatchingParen || !Tok.Next || !Tok.MatchingParen)
1970       return false;
1971 
1972     FormatToken *LeftOfParens = Tok.MatchingParen->getPreviousNonComment();
1973     if (LeftOfParens) {
1974       // If there is a closing parenthesis left of the current
1975       // parentheses, look past it as these might be chained casts.
1976       if (LeftOfParens->is(tok::r_paren) &&
1977           LeftOfParens->isNot(TT_CastRParen)) {
1978         if (!LeftOfParens->MatchingParen ||
1979             !LeftOfParens->MatchingParen->Previous)
1980           return false;
1981         LeftOfParens = LeftOfParens->MatchingParen->Previous;
1982       }
1983 
1984       if (LeftOfParens->is(tok::r_square)) {
1985         //   delete[] (void *)ptr;
1986         auto MayBeArrayDelete = [](FormatToken *Tok) -> FormatToken * {
1987           if (Tok->isNot(tok::r_square))
1988             return nullptr;
1989 
1990           Tok = Tok->getPreviousNonComment();
1991           if (!Tok || Tok->isNot(tok::l_square))
1992             return nullptr;
1993 
1994           Tok = Tok->getPreviousNonComment();
1995           if (!Tok || Tok->isNot(tok::kw_delete))
1996             return nullptr;
1997           return Tok;
1998         };
1999         if (FormatToken *MaybeDelete = MayBeArrayDelete(LeftOfParens))
2000           LeftOfParens = MaybeDelete;
2001       }
2002 
2003       // The Condition directly below this one will see the operator arguments
2004       // as a (void *foo) cast.
2005       //   void operator delete(void *foo) ATTRIB;
2006       if (LeftOfParens->Tok.getIdentifierInfo() && LeftOfParens->Previous &&
2007           LeftOfParens->Previous->is(tok::kw_operator))
2008         return false;
2009 
2010       // If there is an identifier (or with a few exceptions a keyword) right
2011       // before the parentheses, this is unlikely to be a cast.
2012       if (LeftOfParens->Tok.getIdentifierInfo() &&
2013           !LeftOfParens->isOneOf(Keywords.kw_in, tok::kw_return, tok::kw_case,
2014                                  tok::kw_delete))
2015         return false;
2016 
2017       // Certain other tokens right before the parentheses are also signals that
2018       // this cannot be a cast.
2019       if (LeftOfParens->isOneOf(tok::at, tok::r_square, TT_OverloadedOperator,
2020                                 TT_TemplateCloser, tok::ellipsis))
2021         return false;
2022     }
2023 
2024     if (Tok.Next->is(tok::question))
2025       return false;
2026 
2027     // `foreach((A a, B b) in someList)` should not be seen as a cast.
2028     if (Tok.Next->is(Keywords.kw_in) && Style.isCSharp())
2029       return false;
2030 
2031     // Functions which end with decorations like volatile, noexcept are unlikely
2032     // to be casts.
2033     if (Tok.Next->isOneOf(tok::kw_noexcept, tok::kw_volatile, tok::kw_const,
2034                           tok::kw_requires, tok::kw_throw, tok::arrow,
2035                           Keywords.kw_override, Keywords.kw_final) ||
2036         isCpp11AttributeSpecifier(*Tok.Next))
2037       return false;
2038 
2039     // As Java has no function types, a "(" after the ")" likely means that this
2040     // is a cast.
2041     if (Style.Language == FormatStyle::LK_Java && Tok.Next->is(tok::l_paren))
2042       return true;
2043 
2044     // If a (non-string) literal follows, this is likely a cast.
2045     if (Tok.Next->isNot(tok::string_literal) &&
2046         (Tok.Next->Tok.isLiteral() ||
2047          Tok.Next->isOneOf(tok::kw_sizeof, tok::kw_alignof)))
2048       return true;
2049 
2050     // Heuristically try to determine whether the parentheses contain a type.
2051     auto IsQualifiedPointerOrReference = [](FormatToken *T) {
2052       // This is used to handle cases such as x = (foo *const)&y;
2053       assert(!T->isSimpleTypeSpecifier() && "Should have already been checked");
2054       // Strip trailing qualifiers such as const or volatile when checking
2055       // whether the parens could be a cast to a pointer/reference type.
2056       while (T) {
2057         if (T->is(TT_AttributeParen)) {
2058           // Handle `x = (foo *__attribute__((foo)))&v;`:
2059           if (T->MatchingParen && T->MatchingParen->Previous &&
2060               T->MatchingParen->Previous->is(tok::kw___attribute)) {
2061             T = T->MatchingParen->Previous->Previous;
2062             continue;
2063           }
2064         } else if (T->is(TT_AttributeSquare)) {
2065           // Handle `x = (foo *[[clang::foo]])&v;`:
2066           if (T->MatchingParen && T->MatchingParen->Previous) {
2067             T = T->MatchingParen->Previous;
2068             continue;
2069           }
2070         } else if (T->canBePointerOrReferenceQualifier()) {
2071           T = T->Previous;
2072           continue;
2073         }
2074         break;
2075       }
2076       return T && T->is(TT_PointerOrReference);
2077     };
2078     bool ParensAreType =
2079         !Tok.Previous ||
2080         Tok.Previous->isOneOf(TT_TemplateCloser, TT_TypeDeclarationParen) ||
2081         Tok.Previous->isSimpleTypeSpecifier() ||
2082         IsQualifiedPointerOrReference(Tok.Previous);
2083     bool ParensCouldEndDecl =
2084         Tok.Next->isOneOf(tok::equal, tok::semi, tok::l_brace, tok::greater);
2085     if (ParensAreType && !ParensCouldEndDecl)
2086       return true;
2087 
2088     // At this point, we heuristically assume that there are no casts at the
2089     // start of the line. We assume that we have found most cases where there
2090     // are by the logic above, e.g. "(void)x;".
2091     if (!LeftOfParens)
2092       return false;
2093 
2094     // Certain token types inside the parentheses mean that this can't be a
2095     // cast.
2096     for (const FormatToken *Token = Tok.MatchingParen->Next; Token != &Tok;
2097          Token = Token->Next)
2098       if (Token->is(TT_BinaryOperator))
2099         return false;
2100 
2101     // If the following token is an identifier or 'this', this is a cast. All
2102     // cases where this can be something else are handled above.
2103     if (Tok.Next->isOneOf(tok::identifier, tok::kw_this))
2104       return true;
2105 
2106     // Look for a cast `( x ) (`.
2107     if (Tok.Next->is(tok::l_paren) && Tok.Previous && Tok.Previous->Previous) {
2108       if (Tok.Previous->is(tok::identifier) &&
2109           Tok.Previous->Previous->is(tok::l_paren))
2110         return true;
2111     }
2112 
2113     if (!Tok.Next->Next)
2114       return false;
2115 
2116     // If the next token after the parenthesis is a unary operator, assume
2117     // that this is cast, unless there are unexpected tokens inside the
2118     // parenthesis.
2119     bool NextIsUnary =
2120         Tok.Next->isUnaryOperator() || Tok.Next->isOneOf(tok::amp, tok::star);
2121     if (!NextIsUnary || Tok.Next->is(tok::plus) ||
2122         !Tok.Next->Next->isOneOf(tok::identifier, tok::numeric_constant))
2123       return false;
2124     // Search for unexpected tokens.
2125     for (FormatToken *Prev = Tok.Previous; Prev != Tok.MatchingParen;
2126          Prev = Prev->Previous)
2127       if (!Prev->isOneOf(tok::kw_const, tok::identifier, tok::coloncolon))
2128         return false;
2129     return true;
2130   }
2131 
2132   /// Return the type of the given token assuming it is * or &.
2133   TokenType determineStarAmpUsage(const FormatToken &Tok, bool IsExpression,
2134                                   bool InTemplateArgument) {
2135     if (Style.isJavaScript())
2136       return TT_BinaryOperator;
2137 
2138     // && in C# must be a binary operator.
2139     if (Style.isCSharp() && Tok.is(tok::ampamp))
2140       return TT_BinaryOperator;
2141 
2142     const FormatToken *PrevToken = Tok.getPreviousNonComment();
2143     if (!PrevToken)
2144       return TT_UnaryOperator;
2145 
2146     const FormatToken *NextToken = Tok.getNextNonComment();
2147 
2148     if (InTemplateArgument && NextToken && NextToken->is(tok::kw_noexcept))
2149       return TT_BinaryOperator;
2150 
2151     if (!NextToken ||
2152         NextToken->isOneOf(tok::arrow, tok::equal, tok::kw_noexcept) ||
2153         NextToken->canBePointerOrReferenceQualifier() ||
2154         (NextToken->is(tok::l_brace) && !NextToken->getNextNonComment()))
2155       return TT_PointerOrReference;
2156 
2157     if (PrevToken->is(tok::coloncolon))
2158       return TT_PointerOrReference;
2159 
2160     if (PrevToken->is(tok::r_paren) && PrevToken->is(TT_TypeDeclarationParen))
2161       return TT_PointerOrReference;
2162 
2163     if (PrevToken->isOneOf(tok::l_paren, tok::l_square, tok::l_brace,
2164                            tok::comma, tok::semi, tok::kw_return, tok::colon,
2165                            tok::kw_co_return, tok::kw_co_await,
2166                            tok::kw_co_yield, tok::equal, tok::kw_delete,
2167                            tok::kw_sizeof, tok::kw_throw, TT_BinaryOperator,
2168                            TT_ConditionalExpr, TT_UnaryOperator, TT_CastRParen))
2169       return TT_UnaryOperator;
2170 
2171     if (NextToken->is(tok::l_square) && NextToken->isNot(TT_LambdaLSquare))
2172       return TT_PointerOrReference;
2173     if (NextToken->is(tok::kw_operator) && !IsExpression)
2174       return TT_PointerOrReference;
2175     if (NextToken->isOneOf(tok::comma, tok::semi))
2176       return TT_PointerOrReference;
2177 
2178     if (PrevToken->Tok.isLiteral() ||
2179         PrevToken->isOneOf(tok::r_paren, tok::r_square, tok::kw_true,
2180                            tok::kw_false, tok::r_brace))
2181       return TT_BinaryOperator;
2182 
2183     const FormatToken *NextNonParen = NextToken;
2184     while (NextNonParen && NextNonParen->is(tok::l_paren))
2185       NextNonParen = NextNonParen->getNextNonComment();
2186     if (NextNonParen && (NextNonParen->Tok.isLiteral() ||
2187                          NextNonParen->isOneOf(tok::kw_true, tok::kw_false) ||
2188                          NextNonParen->isUnaryOperator()))
2189       return TT_BinaryOperator;
2190 
2191     // If we know we're in a template argument, there are no named declarations.
2192     // Thus, having an identifier on the right-hand side indicates a binary
2193     // operator.
2194     if (InTemplateArgument && NextToken->Tok.isAnyIdentifier())
2195       return TT_BinaryOperator;
2196 
2197     // "&&(" is quite unlikely to be two successive unary "&".
2198     if (Tok.is(tok::ampamp) && NextToken->is(tok::l_paren))
2199       return TT_BinaryOperator;
2200 
2201     // This catches some cases where evaluation order is used as control flow:
2202     //   aaa && aaa->f();
2203     if (NextToken->Tok.isAnyIdentifier()) {
2204       const FormatToken *NextNextToken = NextToken->getNextNonComment();
2205       if (NextNextToken && NextNextToken->is(tok::arrow))
2206         return TT_BinaryOperator;
2207     }
2208 
2209     // It is very unlikely that we are going to find a pointer or reference type
2210     // definition on the RHS of an assignment.
2211     if (IsExpression && !Contexts.back().CaretFound)
2212       return TT_BinaryOperator;
2213 
2214     return TT_PointerOrReference;
2215   }
2216 
2217   TokenType determinePlusMinusCaretUsage(const FormatToken &Tok) {
2218     const FormatToken *PrevToken = Tok.getPreviousNonComment();
2219     if (!PrevToken)
2220       return TT_UnaryOperator;
2221 
2222     if (PrevToken->isOneOf(TT_CastRParen, TT_UnaryOperator))
2223       // This must be a sequence of leading unary operators.
2224       return TT_UnaryOperator;
2225 
2226     // Use heuristics to recognize unary operators.
2227     if (PrevToken->isOneOf(tok::equal, tok::l_paren, tok::comma, tok::l_square,
2228                            tok::question, tok::colon, tok::kw_return,
2229                            tok::kw_case, tok::at, tok::l_brace, tok::kw_throw,
2230                            tok::kw_co_return, tok::kw_co_yield))
2231       return TT_UnaryOperator;
2232 
2233     // There can't be two consecutive binary operators.
2234     if (PrevToken->is(TT_BinaryOperator))
2235       return TT_UnaryOperator;
2236 
2237     // Fall back to marking the token as binary operator.
2238     return TT_BinaryOperator;
2239   }
2240 
2241   /// Determine whether ++/-- are pre- or post-increments/-decrements.
2242   TokenType determineIncrementUsage(const FormatToken &Tok) {
2243     const FormatToken *PrevToken = Tok.getPreviousNonComment();
2244     if (!PrevToken || PrevToken->is(TT_CastRParen))
2245       return TT_UnaryOperator;
2246     if (PrevToken->isOneOf(tok::r_paren, tok::r_square, tok::identifier))
2247       return TT_TrailingUnaryOperator;
2248 
2249     return TT_UnaryOperator;
2250   }
2251 
2252   SmallVector<Context, 8> Contexts;
2253 
2254   const FormatStyle &Style;
2255   AnnotatedLine &Line;
2256   FormatToken *CurrentToken;
2257   bool AutoFound;
2258   const AdditionalKeywords &Keywords;
2259 
2260   // Set of "<" tokens that do not open a template parameter list. If parseAngle
2261   // determines that a specific token can't be a template opener, it will make
2262   // same decision irrespective of the decisions for tokens leading up to it.
2263   // Store this information to prevent this from causing exponential runtime.
2264   llvm::SmallPtrSet<FormatToken *, 16> NonTemplateLess;
2265 };
2266 
2267 static const int PrecedenceUnaryOperator = prec::PointerToMember + 1;
2268 static const int PrecedenceArrowAndPeriod = prec::PointerToMember + 2;
2269 
2270 /// Parses binary expressions by inserting fake parenthesis based on
2271 /// operator precedence.
2272 class ExpressionParser {
2273 public:
2274   ExpressionParser(const FormatStyle &Style, const AdditionalKeywords &Keywords,
2275                    AnnotatedLine &Line)
2276       : Style(Style), Keywords(Keywords), Line(Line), Current(Line.First) {}
2277 
2278   /// Parse expressions with the given operator precedence.
2279   void parse(int Precedence = 0) {
2280     // Skip 'return' and ObjC selector colons as they are not part of a binary
2281     // expression.
2282     while (Current && (Current->is(tok::kw_return) ||
2283                        (Current->is(tok::colon) &&
2284                         Current->isOneOf(TT_ObjCMethodExpr, TT_DictLiteral))))
2285       next();
2286 
2287     if (!Current || Precedence > PrecedenceArrowAndPeriod)
2288       return;
2289 
2290     // Conditional expressions need to be parsed separately for proper nesting.
2291     if (Precedence == prec::Conditional) {
2292       parseConditionalExpr();
2293       return;
2294     }
2295 
2296     // Parse unary operators, which all have a higher precedence than binary
2297     // operators.
2298     if (Precedence == PrecedenceUnaryOperator) {
2299       parseUnaryOperator();
2300       return;
2301     }
2302 
2303     FormatToken *Start = Current;
2304     FormatToken *LatestOperator = nullptr;
2305     unsigned OperatorIndex = 0;
2306 
2307     while (Current) {
2308       // Consume operators with higher precedence.
2309       parse(Precedence + 1);
2310 
2311       int CurrentPrecedence = getCurrentPrecedence();
2312 
2313       if (Precedence == CurrentPrecedence && Current &&
2314           Current->is(TT_SelectorName)) {
2315         if (LatestOperator)
2316           addFakeParenthesis(Start, prec::Level(Precedence));
2317         Start = Current;
2318       }
2319 
2320       // At the end of the line or when an operator with higher precedence is
2321       // found, insert fake parenthesis and return.
2322       if (!Current ||
2323           (Current->closesScope() &&
2324            (Current->MatchingParen || Current->is(TT_TemplateString))) ||
2325           (CurrentPrecedence != -1 && CurrentPrecedence < Precedence) ||
2326           (CurrentPrecedence == prec::Conditional &&
2327            Precedence == prec::Assignment && Current->is(tok::colon)))
2328         break;
2329 
2330       // Consume scopes: (), [], <> and {}
2331       // In addition to that we handle require clauses as scope, so that the
2332       // constraints in that are correctly indented.
2333       if (Current->opensScope() ||
2334           Current->isOneOf(TT_RequiresClause,
2335                            TT_RequiresClauseInARequiresExpression)) {
2336         // In fragment of a JavaScript template string can look like '}..${' and
2337         // thus close a scope and open a new one at the same time.
2338         while (Current && (!Current->closesScope() || Current->opensScope())) {
2339           next();
2340           parse();
2341         }
2342         next();
2343       } else {
2344         // Operator found.
2345         if (CurrentPrecedence == Precedence) {
2346           if (LatestOperator)
2347             LatestOperator->NextOperator = Current;
2348           LatestOperator = Current;
2349           Current->OperatorIndex = OperatorIndex;
2350           ++OperatorIndex;
2351         }
2352         next(/*SkipPastLeadingComments=*/Precedence > 0);
2353       }
2354     }
2355 
2356     if (LatestOperator && (Current || Precedence > 0)) {
2357       // The requires clauses do not neccessarily end in a semicolon or a brace,
2358       // but just go over to struct/class or a function declaration, we need to
2359       // intervene so that the fake right paren is inserted correctly.
2360       auto End =
2361           (Start->Previous &&
2362            Start->Previous->isOneOf(TT_RequiresClause,
2363                                     TT_RequiresClauseInARequiresExpression))
2364               ? [this](){
2365                   auto Ret = Current ? Current : Line.Last;
2366                   while (!Ret->ClosesRequiresClause && Ret->Previous)
2367                     Ret = Ret->Previous;
2368                   return Ret;
2369                 }()
2370               : nullptr;
2371 
2372       if (Precedence == PrecedenceArrowAndPeriod) {
2373         // Call expressions don't have a binary operator precedence.
2374         addFakeParenthesis(Start, prec::Unknown, End);
2375       } else {
2376         addFakeParenthesis(Start, prec::Level(Precedence), End);
2377       }
2378     }
2379   }
2380 
2381 private:
2382   /// Gets the precedence (+1) of the given token for binary operators
2383   /// and other tokens that we treat like binary operators.
2384   int getCurrentPrecedence() {
2385     if (Current) {
2386       const FormatToken *NextNonComment = Current->getNextNonComment();
2387       if (Current->is(TT_ConditionalExpr))
2388         return prec::Conditional;
2389       if (NextNonComment && Current->is(TT_SelectorName) &&
2390           (NextNonComment->isOneOf(TT_DictLiteral, TT_JsTypeColon) ||
2391            ((Style.Language == FormatStyle::LK_Proto ||
2392              Style.Language == FormatStyle::LK_TextProto) &&
2393             NextNonComment->is(tok::less))))
2394         return prec::Assignment;
2395       if (Current->is(TT_JsComputedPropertyName))
2396         return prec::Assignment;
2397       if (Current->is(TT_LambdaArrow))
2398         return prec::Comma;
2399       if (Current->is(TT_FatArrow))
2400         return prec::Assignment;
2401       if (Current->isOneOf(tok::semi, TT_InlineASMColon, TT_SelectorName) ||
2402           (Current->is(tok::comment) && NextNonComment &&
2403            NextNonComment->is(TT_SelectorName)))
2404         return 0;
2405       if (Current->is(TT_RangeBasedForLoopColon))
2406         return prec::Comma;
2407       if ((Style.Language == FormatStyle::LK_Java || Style.isJavaScript()) &&
2408           Current->is(Keywords.kw_instanceof))
2409         return prec::Relational;
2410       if (Style.isJavaScript() &&
2411           Current->isOneOf(Keywords.kw_in, Keywords.kw_as))
2412         return prec::Relational;
2413       if (Current->is(TT_BinaryOperator) || Current->is(tok::comma))
2414         return Current->getPrecedence();
2415       if (Current->isOneOf(tok::period, tok::arrow))
2416         return PrecedenceArrowAndPeriod;
2417       if ((Style.Language == FormatStyle::LK_Java || Style.isJavaScript()) &&
2418           Current->isOneOf(Keywords.kw_extends, Keywords.kw_implements,
2419                            Keywords.kw_throws))
2420         return 0;
2421     }
2422     return -1;
2423   }
2424 
2425   void addFakeParenthesis(FormatToken *Start, prec::Level Precedence,
2426                           FormatToken *End = nullptr) {
2427     Start->FakeLParens.push_back(Precedence);
2428     if (Precedence > prec::Unknown)
2429       Start->StartsBinaryExpression = true;
2430     if (!End && Current)
2431       End = Current->getPreviousNonComment();
2432     if (End) {
2433       ++End->FakeRParens;
2434       if (Precedence > prec::Unknown)
2435         End->EndsBinaryExpression = true;
2436     }
2437   }
2438 
2439   /// Parse unary operator expressions and surround them with fake
2440   /// parentheses if appropriate.
2441   void parseUnaryOperator() {
2442     llvm::SmallVector<FormatToken *, 2> Tokens;
2443     while (Current && Current->is(TT_UnaryOperator)) {
2444       Tokens.push_back(Current);
2445       next();
2446     }
2447     parse(PrecedenceArrowAndPeriod);
2448     for (FormatToken *Token : llvm::reverse(Tokens))
2449       // The actual precedence doesn't matter.
2450       addFakeParenthesis(Token, prec::Unknown);
2451   }
2452 
2453   void parseConditionalExpr() {
2454     while (Current && Current->isTrailingComment())
2455       next();
2456     FormatToken *Start = Current;
2457     parse(prec::LogicalOr);
2458     if (!Current || !Current->is(tok::question))
2459       return;
2460     next();
2461     parse(prec::Assignment);
2462     if (!Current || Current->isNot(TT_ConditionalExpr))
2463       return;
2464     next();
2465     parse(prec::Assignment);
2466     addFakeParenthesis(Start, prec::Conditional);
2467   }
2468 
2469   void next(bool SkipPastLeadingComments = true) {
2470     if (Current)
2471       Current = Current->Next;
2472     while (Current &&
2473            (Current->NewlinesBefore == 0 || SkipPastLeadingComments) &&
2474            Current->isTrailingComment())
2475       Current = Current->Next;
2476   }
2477 
2478   const FormatStyle &Style;
2479   const AdditionalKeywords &Keywords;
2480   const AnnotatedLine &Line;
2481   FormatToken *Current;
2482 };
2483 
2484 } // end anonymous namespace
2485 
2486 void TokenAnnotator::setCommentLineLevels(
2487     SmallVectorImpl<AnnotatedLine *> &Lines) {
2488   const AnnotatedLine *NextNonCommentLine = nullptr;
2489   for (AnnotatedLine *Line : llvm::reverse(Lines)) {
2490     assert(Line->First);
2491     bool CommentLine = true;
2492     for (const FormatToken *Tok = Line->First; Tok; Tok = Tok->Next) {
2493       if (!Tok->is(tok::comment)) {
2494         CommentLine = false;
2495         break;
2496       }
2497     }
2498 
2499     // If the comment is currently aligned with the line immediately following
2500     // it, that's probably intentional and we should keep it.
2501     if (NextNonCommentLine && CommentLine &&
2502         NextNonCommentLine->First->NewlinesBefore <= 1 &&
2503         NextNonCommentLine->First->OriginalColumn ==
2504             Line->First->OriginalColumn) {
2505       // Align comments for preprocessor lines with the # in column 0 if
2506       // preprocessor lines are not indented. Otherwise, align with the next
2507       // line.
2508       Line->Level =
2509           (Style.IndentPPDirectives != FormatStyle::PPDIS_BeforeHash &&
2510            (NextNonCommentLine->Type == LT_PreprocessorDirective ||
2511             NextNonCommentLine->Type == LT_ImportStatement))
2512               ? 0
2513               : NextNonCommentLine->Level;
2514     } else {
2515       NextNonCommentLine = Line->First->isNot(tok::r_brace) ? Line : nullptr;
2516     }
2517 
2518     setCommentLineLevels(Line->Children);
2519   }
2520 }
2521 
2522 static unsigned maxNestingDepth(const AnnotatedLine &Line) {
2523   unsigned Result = 0;
2524   for (const auto *Tok = Line.First; Tok != nullptr; Tok = Tok->Next)
2525     Result = std::max(Result, Tok->NestingLevel);
2526   return Result;
2527 }
2528 
2529 void TokenAnnotator::annotate(AnnotatedLine &Line) {
2530   for (auto &Child : Line.Children)
2531     annotate(*Child);
2532 
2533   AnnotatingParser Parser(Style, Line, Keywords);
2534   Line.Type = Parser.parseLine();
2535 
2536   // With very deep nesting, ExpressionParser uses lots of stack and the
2537   // formatting algorithm is very slow. We're not going to do a good job here
2538   // anyway - it's probably generated code being formatted by mistake.
2539   // Just skip the whole line.
2540   if (maxNestingDepth(Line) > 50)
2541     Line.Type = LT_Invalid;
2542 
2543   if (Line.Type == LT_Invalid)
2544     return;
2545 
2546   ExpressionParser ExprParser(Style, Keywords, Line);
2547   ExprParser.parse();
2548 
2549   if (Line.startsWith(TT_ObjCMethodSpecifier))
2550     Line.Type = LT_ObjCMethodDecl;
2551   else if (Line.startsWith(TT_ObjCDecl))
2552     Line.Type = LT_ObjCDecl;
2553   else if (Line.startsWith(TT_ObjCProperty))
2554     Line.Type = LT_ObjCProperty;
2555 
2556   Line.First->SpacesRequiredBefore = 1;
2557   Line.First->CanBreakBefore = Line.First->MustBreakBefore;
2558 }
2559 
2560 // This function heuristically determines whether 'Current' starts the name of a
2561 // function declaration.
2562 static bool isFunctionDeclarationName(bool IsCpp, const FormatToken &Current,
2563                                       const AnnotatedLine &Line) {
2564   auto skipOperatorName = [](const FormatToken *Next) -> const FormatToken * {
2565     for (; Next; Next = Next->Next) {
2566       if (Next->is(TT_OverloadedOperatorLParen))
2567         return Next;
2568       if (Next->is(TT_OverloadedOperator))
2569         continue;
2570       if (Next->isOneOf(tok::kw_new, tok::kw_delete)) {
2571         // For 'new[]' and 'delete[]'.
2572         if (Next->Next &&
2573             Next->Next->startsSequence(tok::l_square, tok::r_square))
2574           Next = Next->Next->Next;
2575         continue;
2576       }
2577       if (Next->startsSequence(tok::l_square, tok::r_square)) {
2578         // For operator[]().
2579         Next = Next->Next;
2580         continue;
2581       }
2582       if ((Next->isSimpleTypeSpecifier() || Next->is(tok::identifier)) &&
2583           Next->Next && Next->Next->isOneOf(tok::star, tok::amp, tok::ampamp)) {
2584         // For operator void*(), operator char*(), operator Foo*().
2585         Next = Next->Next;
2586         continue;
2587       }
2588       if (Next->is(TT_TemplateOpener) && Next->MatchingParen) {
2589         Next = Next->MatchingParen;
2590         continue;
2591       }
2592 
2593       break;
2594     }
2595     return nullptr;
2596   };
2597 
2598   // Find parentheses of parameter list.
2599   const FormatToken *Next = Current.Next;
2600   if (Current.is(tok::kw_operator)) {
2601     if (Current.Previous && Current.Previous->is(tok::coloncolon))
2602       return false;
2603     Next = skipOperatorName(Next);
2604   } else {
2605     if (!Current.is(TT_StartOfName) || Current.NestingLevel != 0)
2606       return false;
2607     for (; Next; Next = Next->Next) {
2608       if (Next->is(TT_TemplateOpener)) {
2609         Next = Next->MatchingParen;
2610       } else if (Next->is(tok::coloncolon)) {
2611         Next = Next->Next;
2612         if (!Next)
2613           return false;
2614         if (Next->is(tok::kw_operator)) {
2615           Next = skipOperatorName(Next->Next);
2616           break;
2617         }
2618         if (!Next->is(tok::identifier))
2619           return false;
2620       } else if (Next->is(tok::l_paren)) {
2621         break;
2622       } else {
2623         return false;
2624       }
2625     }
2626   }
2627 
2628   // Check whether parameter list can belong to a function declaration.
2629   if (!Next || !Next->is(tok::l_paren) || !Next->MatchingParen)
2630     return false;
2631   // If the lines ends with "{", this is likely a function definition.
2632   if (Line.Last->is(tok::l_brace))
2633     return true;
2634   if (Next->Next == Next->MatchingParen)
2635     return true; // Empty parentheses.
2636   // If there is an &/&& after the r_paren, this is likely a function.
2637   if (Next->MatchingParen->Next &&
2638       Next->MatchingParen->Next->is(TT_PointerOrReference))
2639     return true;
2640 
2641   // Check for K&R C function definitions (and C++ function definitions with
2642   // unnamed parameters), e.g.:
2643   //   int f(i)
2644   //   {
2645   //     return i + 1;
2646   //   }
2647   //   bool g(size_t = 0, bool b = false)
2648   //   {
2649   //     return !b;
2650   //   }
2651   if (IsCpp && Next->Next && Next->Next->is(tok::identifier) &&
2652       !Line.endsWith(tok::semi))
2653     return true;
2654 
2655   for (const FormatToken *Tok = Next->Next; Tok && Tok != Next->MatchingParen;
2656        Tok = Tok->Next) {
2657     if (Tok->is(TT_TypeDeclarationParen))
2658       return true;
2659     if (Tok->isOneOf(tok::l_paren, TT_TemplateOpener) && Tok->MatchingParen) {
2660       Tok = Tok->MatchingParen;
2661       continue;
2662     }
2663     if (Tok->is(tok::kw_const) || Tok->isSimpleTypeSpecifier() ||
2664         Tok->isOneOf(TT_PointerOrReference, TT_StartOfName, tok::ellipsis))
2665       return true;
2666     if (Tok->isOneOf(tok::l_brace, tok::string_literal, TT_ObjCMethodExpr) ||
2667         Tok->Tok.isLiteral())
2668       return false;
2669   }
2670   return false;
2671 }
2672 
2673 bool TokenAnnotator::mustBreakForReturnType(const AnnotatedLine &Line) const {
2674   assert(Line.MightBeFunctionDecl);
2675 
2676   if ((Style.AlwaysBreakAfterReturnType == FormatStyle::RTBS_TopLevel ||
2677        Style.AlwaysBreakAfterReturnType ==
2678            FormatStyle::RTBS_TopLevelDefinitions) &&
2679       Line.Level > 0)
2680     return false;
2681 
2682   switch (Style.AlwaysBreakAfterReturnType) {
2683   case FormatStyle::RTBS_None:
2684     return false;
2685   case FormatStyle::RTBS_All:
2686   case FormatStyle::RTBS_TopLevel:
2687     return true;
2688   case FormatStyle::RTBS_AllDefinitions:
2689   case FormatStyle::RTBS_TopLevelDefinitions:
2690     return Line.mightBeFunctionDefinition();
2691   }
2692 
2693   return false;
2694 }
2695 
2696 void TokenAnnotator::calculateFormattingInformation(AnnotatedLine &Line) {
2697   for (AnnotatedLine *ChildLine : Line.Children)
2698     calculateFormattingInformation(*ChildLine);
2699 
2700   Line.First->TotalLength =
2701       Line.First->IsMultiline ? Style.ColumnLimit
2702                               : Line.FirstStartColumn + Line.First->ColumnWidth;
2703   FormatToken *Current = Line.First->Next;
2704   bool InFunctionDecl = Line.MightBeFunctionDecl;
2705   bool AlignArrayOfStructures =
2706       (Style.AlignArrayOfStructures != FormatStyle::AIAS_None &&
2707        Line.Type == LT_ArrayOfStructInitializer);
2708   if (AlignArrayOfStructures)
2709     calculateArrayInitializerColumnList(Line);
2710 
2711   while (Current) {
2712     if (isFunctionDeclarationName(Style.isCpp(), *Current, Line))
2713       Current->setType(TT_FunctionDeclarationName);
2714     const FormatToken *Prev = Current->Previous;
2715     if (Current->is(TT_LineComment)) {
2716       if (Prev->is(BK_BracedInit) && Prev->opensScope())
2717         Current->SpacesRequiredBefore =
2718             (Style.Cpp11BracedListStyle && !Style.SpacesInParentheses) ? 0 : 1;
2719       else
2720         Current->SpacesRequiredBefore = Style.SpacesBeforeTrailingComments;
2721 
2722       // If we find a trailing comment, iterate backwards to determine whether
2723       // it seems to relate to a specific parameter. If so, break before that
2724       // parameter to avoid changing the comment's meaning. E.g. don't move 'b'
2725       // to the previous line in:
2726       //   SomeFunction(a,
2727       //                b, // comment
2728       //                c);
2729       if (!Current->HasUnescapedNewline) {
2730         for (FormatToken *Parameter = Current->Previous; Parameter;
2731              Parameter = Parameter->Previous) {
2732           if (Parameter->isOneOf(tok::comment, tok::r_brace))
2733             break;
2734           if (Parameter->Previous && Parameter->Previous->is(tok::comma)) {
2735             if (!Parameter->Previous->is(TT_CtorInitializerComma) &&
2736                 Parameter->HasUnescapedNewline)
2737               Parameter->MustBreakBefore = true;
2738             break;
2739           }
2740         }
2741       }
2742     } else if (Current->SpacesRequiredBefore == 0 &&
2743                spaceRequiredBefore(Line, *Current)) {
2744       Current->SpacesRequiredBefore = 1;
2745     }
2746 
2747     Current->MustBreakBefore =
2748         Current->MustBreakBefore || mustBreakBefore(Line, *Current);
2749 
2750     if (!Current->MustBreakBefore && InFunctionDecl &&
2751         Current->is(TT_FunctionDeclarationName))
2752       Current->MustBreakBefore = mustBreakForReturnType(Line);
2753 
2754     Current->CanBreakBefore =
2755         Current->MustBreakBefore || canBreakBefore(Line, *Current);
2756     unsigned ChildSize = 0;
2757     if (Prev->Children.size() == 1) {
2758       FormatToken &LastOfChild = *Prev->Children[0]->Last;
2759       ChildSize = LastOfChild.isTrailingComment() ? Style.ColumnLimit
2760                                                   : LastOfChild.TotalLength + 1;
2761     }
2762     if (Current->MustBreakBefore || Prev->Children.size() > 1 ||
2763         (Prev->Children.size() == 1 &&
2764          Prev->Children[0]->First->MustBreakBefore) ||
2765         Current->IsMultiline)
2766       Current->TotalLength = Prev->TotalLength + Style.ColumnLimit;
2767     else
2768       Current->TotalLength = Prev->TotalLength + Current->ColumnWidth +
2769                              ChildSize + Current->SpacesRequiredBefore;
2770 
2771     if (Current->is(TT_CtorInitializerColon))
2772       InFunctionDecl = false;
2773 
2774     // FIXME: Only calculate this if CanBreakBefore is true once static
2775     // initializers etc. are sorted out.
2776     // FIXME: Move magic numbers to a better place.
2777 
2778     // Reduce penalty for aligning ObjC method arguments using the colon
2779     // alignment as this is the canonical way (still prefer fitting everything
2780     // into one line if possible). Trying to fit a whole expression into one
2781     // line should not force other line breaks (e.g. when ObjC method
2782     // expression is a part of other expression).
2783     Current->SplitPenalty = splitPenalty(Line, *Current, InFunctionDecl);
2784     if (Style.Language == FormatStyle::LK_ObjC &&
2785         Current->is(TT_SelectorName) && Current->ParameterIndex > 0) {
2786       if (Current->ParameterIndex == 1)
2787         Current->SplitPenalty += 5 * Current->BindingStrength;
2788     } else {
2789       Current->SplitPenalty += 20 * Current->BindingStrength;
2790     }
2791 
2792     Current = Current->Next;
2793   }
2794 
2795   calculateUnbreakableTailLengths(Line);
2796   unsigned IndentLevel = Line.Level;
2797   for (Current = Line.First; Current != nullptr; Current = Current->Next) {
2798     if (Current->Role)
2799       Current->Role->precomputeFormattingInfos(Current);
2800     if (Current->MatchingParen &&
2801         Current->MatchingParen->opensBlockOrBlockTypeList(Style) &&
2802         IndentLevel > 0)
2803       --IndentLevel;
2804     Current->IndentLevel = IndentLevel;
2805     if (Current->opensBlockOrBlockTypeList(Style))
2806       ++IndentLevel;
2807   }
2808 
2809   LLVM_DEBUG({ printDebugInfo(Line); });
2810 }
2811 
2812 void TokenAnnotator::calculateUnbreakableTailLengths(AnnotatedLine &Line) {
2813   unsigned UnbreakableTailLength = 0;
2814   FormatToken *Current = Line.Last;
2815   while (Current) {
2816     Current->UnbreakableTailLength = UnbreakableTailLength;
2817     if (Current->CanBreakBefore ||
2818         Current->isOneOf(tok::comment, tok::string_literal)) {
2819       UnbreakableTailLength = 0;
2820     } else {
2821       UnbreakableTailLength +=
2822           Current->ColumnWidth + Current->SpacesRequiredBefore;
2823     }
2824     Current = Current->Previous;
2825   }
2826 }
2827 
2828 void TokenAnnotator::calculateArrayInitializerColumnList(AnnotatedLine &Line) {
2829   if (Line.First == Line.Last)
2830     return;
2831   auto *CurrentToken = Line.First;
2832   CurrentToken->ArrayInitializerLineStart = true;
2833   unsigned Depth = 0;
2834   while (CurrentToken != nullptr && CurrentToken != Line.Last) {
2835     if (CurrentToken->is(tok::l_brace)) {
2836       CurrentToken->IsArrayInitializer = true;
2837       if (CurrentToken->Next != nullptr)
2838         CurrentToken->Next->MustBreakBefore = true;
2839       CurrentToken =
2840           calculateInitializerColumnList(Line, CurrentToken->Next, Depth + 1);
2841     } else {
2842       CurrentToken = CurrentToken->Next;
2843     }
2844   }
2845 }
2846 
2847 FormatToken *TokenAnnotator::calculateInitializerColumnList(
2848     AnnotatedLine &Line, FormatToken *CurrentToken, unsigned Depth) {
2849   while (CurrentToken != nullptr && CurrentToken != Line.Last) {
2850     if (CurrentToken->is(tok::l_brace))
2851       ++Depth;
2852     else if (CurrentToken->is(tok::r_brace))
2853       --Depth;
2854     if (Depth == 2 && CurrentToken->isOneOf(tok::l_brace, tok::comma)) {
2855       CurrentToken = CurrentToken->Next;
2856       if (CurrentToken == nullptr)
2857         break;
2858       CurrentToken->StartsColumn = true;
2859       CurrentToken = CurrentToken->Previous;
2860     }
2861     CurrentToken = CurrentToken->Next;
2862   }
2863   return CurrentToken;
2864 }
2865 
2866 unsigned TokenAnnotator::splitPenalty(const AnnotatedLine &Line,
2867                                       const FormatToken &Tok,
2868                                       bool InFunctionDecl) {
2869   const FormatToken &Left = *Tok.Previous;
2870   const FormatToken &Right = Tok;
2871 
2872   if (Left.is(tok::semi))
2873     return 0;
2874 
2875   if (Style.Language == FormatStyle::LK_Java) {
2876     if (Right.isOneOf(Keywords.kw_extends, Keywords.kw_throws))
2877       return 1;
2878     if (Right.is(Keywords.kw_implements))
2879       return 2;
2880     if (Left.is(tok::comma) && Left.NestingLevel == 0)
2881       return 3;
2882   } else if (Style.isJavaScript()) {
2883     if (Right.is(Keywords.kw_function) && Left.isNot(tok::comma))
2884       return 100;
2885     if (Left.is(TT_JsTypeColon))
2886       return 35;
2887     if ((Left.is(TT_TemplateString) && Left.TokenText.endswith("${")) ||
2888         (Right.is(TT_TemplateString) && Right.TokenText.startswith("}")))
2889       return 100;
2890     // Prefer breaking call chains (".foo") over empty "{}", "[]" or "()".
2891     if (Left.opensScope() && Right.closesScope())
2892       return 200;
2893   }
2894 
2895   if (Right.is(tok::identifier) && Right.Next && Right.Next->is(TT_DictLiteral))
2896     return 1;
2897   if (Right.is(tok::l_square)) {
2898     if (Style.Language == FormatStyle::LK_Proto)
2899       return 1;
2900     if (Left.is(tok::r_square))
2901       return 200;
2902     // Slightly prefer formatting local lambda definitions like functions.
2903     if (Right.is(TT_LambdaLSquare) && Left.is(tok::equal))
2904       return 35;
2905     if (!Right.isOneOf(TT_ObjCMethodExpr, TT_LambdaLSquare,
2906                        TT_ArrayInitializerLSquare,
2907                        TT_DesignatedInitializerLSquare, TT_AttributeSquare))
2908       return 500;
2909   }
2910 
2911   if (Left.is(tok::coloncolon) ||
2912       (Right.is(tok::period) && Style.Language == FormatStyle::LK_Proto))
2913     return 500;
2914   if (Right.isOneOf(TT_StartOfName, TT_FunctionDeclarationName) ||
2915       Right.is(tok::kw_operator)) {
2916     if (Line.startsWith(tok::kw_for) && Right.PartOfMultiVariableDeclStmt)
2917       return 3;
2918     if (Left.is(TT_StartOfName))
2919       return 110;
2920     if (InFunctionDecl && Right.NestingLevel == 0)
2921       return Style.PenaltyReturnTypeOnItsOwnLine;
2922     return 200;
2923   }
2924   if (Right.is(TT_PointerOrReference))
2925     return 190;
2926   if (Right.is(TT_LambdaArrow))
2927     return 110;
2928   if (Left.is(tok::equal) && Right.is(tok::l_brace))
2929     return 160;
2930   if (Left.is(TT_CastRParen))
2931     return 100;
2932   if (Left.isOneOf(tok::kw_class, tok::kw_struct))
2933     return 5000;
2934   if (Left.is(tok::comment))
2935     return 1000;
2936 
2937   if (Left.isOneOf(TT_RangeBasedForLoopColon, TT_InheritanceColon,
2938                    TT_CtorInitializerColon))
2939     return 2;
2940 
2941   if (Right.isMemberAccess()) {
2942     // Breaking before the "./->" of a chained call/member access is reasonably
2943     // cheap, as formatting those with one call per line is generally
2944     // desirable. In particular, it should be cheaper to break before the call
2945     // than it is to break inside a call's parameters, which could lead to weird
2946     // "hanging" indents. The exception is the very last "./->" to support this
2947     // frequent pattern:
2948     //
2949     //   aaaaaaaa.aaaaaaaa.bbbbbbb().ccccccccccccccccccccc(
2950     //       dddddddd);
2951     //
2952     // which might otherwise be blown up onto many lines. Here, clang-format
2953     // won't produce "hanging" indents anyway as there is no other trailing
2954     // call.
2955     //
2956     // Also apply higher penalty is not a call as that might lead to a wrapping
2957     // like:
2958     //
2959     //   aaaaaaa
2960     //       .aaaaaaaaa.bbbbbbbb(cccccccc);
2961     return !Right.NextOperator || !Right.NextOperator->Previous->closesScope()
2962                ? 150
2963                : 35;
2964   }
2965 
2966   if (Right.is(TT_TrailingAnnotation) &&
2967       (!Right.Next || Right.Next->isNot(tok::l_paren))) {
2968     // Moving trailing annotations to the next line is fine for ObjC method
2969     // declarations.
2970     if (Line.startsWith(TT_ObjCMethodSpecifier))
2971       return 10;
2972     // Generally, breaking before a trailing annotation is bad unless it is
2973     // function-like. It seems to be especially preferable to keep standard
2974     // annotations (i.e. "const", "final" and "override") on the same line.
2975     // Use a slightly higher penalty after ")" so that annotations like
2976     // "const override" are kept together.
2977     bool is_short_annotation = Right.TokenText.size() < 10;
2978     return (Left.is(tok::r_paren) ? 100 : 120) + (is_short_annotation ? 50 : 0);
2979   }
2980 
2981   // In for-loops, prefer breaking at ',' and ';'.
2982   if (Line.startsWith(tok::kw_for) && Left.is(tok::equal))
2983     return 4;
2984 
2985   // In Objective-C method expressions, prefer breaking before "param:" over
2986   // breaking after it.
2987   if (Right.is(TT_SelectorName))
2988     return 0;
2989   if (Left.is(tok::colon) && Left.is(TT_ObjCMethodExpr))
2990     return Line.MightBeFunctionDecl ? 50 : 500;
2991 
2992   // In Objective-C type declarations, avoid breaking after the category's
2993   // open paren (we'll prefer breaking after the protocol list's opening
2994   // angle bracket, if present).
2995   if (Line.Type == LT_ObjCDecl && Left.is(tok::l_paren) && Left.Previous &&
2996       Left.Previous->isOneOf(tok::identifier, tok::greater))
2997     return 500;
2998 
2999   if (Left.is(tok::l_paren) && Style.PenaltyBreakOpenParenthesis != 0)
3000     return Style.PenaltyBreakOpenParenthesis;
3001   if (Left.is(tok::l_paren) && InFunctionDecl &&
3002       Style.AlignAfterOpenBracket != FormatStyle::BAS_DontAlign)
3003     return 100;
3004   if (Left.is(tok::l_paren) && Left.Previous &&
3005       (Left.Previous->is(tok::kw_for) || Left.Previous->isIf()))
3006     return 1000;
3007   if (Left.is(tok::equal) && InFunctionDecl)
3008     return 110;
3009   if (Right.is(tok::r_brace))
3010     return 1;
3011   if (Left.is(TT_TemplateOpener))
3012     return 100;
3013   if (Left.opensScope()) {
3014     // If we aren't aligning after opening parens/braces we can always break
3015     // here unless the style does not want us to place all arguments on the
3016     // next line.
3017     if (Style.AlignAfterOpenBracket == FormatStyle::BAS_DontAlign &&
3018         (Left.ParameterCount <= 1 || Style.AllowAllArgumentsOnNextLine))
3019       return 0;
3020     if (Left.is(tok::l_brace) && !Style.Cpp11BracedListStyle)
3021       return 19;
3022     return Left.ParameterCount > 1 ? Style.PenaltyBreakBeforeFirstCallParameter
3023                                    : 19;
3024   }
3025   if (Left.is(TT_JavaAnnotation))
3026     return 50;
3027 
3028   if (Left.is(TT_UnaryOperator))
3029     return 60;
3030   if (Left.isOneOf(tok::plus, tok::comma) && Left.Previous &&
3031       Left.Previous->isLabelString() &&
3032       (Left.NextOperator || Left.OperatorIndex != 0))
3033     return 50;
3034   if (Right.is(tok::plus) && Left.isLabelString() &&
3035       (Right.NextOperator || Right.OperatorIndex != 0))
3036     return 25;
3037   if (Left.is(tok::comma))
3038     return 1;
3039   if (Right.is(tok::lessless) && Left.isLabelString() &&
3040       (Right.NextOperator || Right.OperatorIndex != 1))
3041     return 25;
3042   if (Right.is(tok::lessless)) {
3043     // Breaking at a << is really cheap.
3044     if (!Left.is(tok::r_paren) || Right.OperatorIndex > 0)
3045       // Slightly prefer to break before the first one in log-like statements.
3046       return 2;
3047     return 1;
3048   }
3049   if (Left.ClosesTemplateDeclaration)
3050     return Style.PenaltyBreakTemplateDeclaration;
3051   if (Left.ClosesRequiresClause)
3052     return 0;
3053   if (Left.is(TT_ConditionalExpr))
3054     return prec::Conditional;
3055   prec::Level Level = Left.getPrecedence();
3056   if (Level == prec::Unknown)
3057     Level = Right.getPrecedence();
3058   if (Level == prec::Assignment)
3059     return Style.PenaltyBreakAssignment;
3060   if (Level != prec::Unknown)
3061     return Level;
3062 
3063   return 3;
3064 }
3065 
3066 bool TokenAnnotator::spaceRequiredBeforeParens(const FormatToken &Right) const {
3067   if (Style.SpaceBeforeParens == FormatStyle::SBPO_Always)
3068     return true;
3069   if (Right.is(TT_OverloadedOperatorLParen) &&
3070       Style.SpaceBeforeParensOptions.AfterOverloadedOperator)
3071     return true;
3072   if (Style.SpaceBeforeParensOptions.BeforeNonEmptyParentheses &&
3073       Right.ParameterCount > 0)
3074     return true;
3075   return false;
3076 }
3077 
3078 bool TokenAnnotator::spaceRequiredBetween(const AnnotatedLine &Line,
3079                                           const FormatToken &Left,
3080                                           const FormatToken &Right) {
3081   if (Left.is(tok::kw_return) &&
3082       !Right.isOneOf(tok::semi, tok::r_paren, tok::hashhash))
3083     return true;
3084   if (Style.isJson() && Left.is(tok::string_literal) && Right.is(tok::colon))
3085     return false;
3086   if (Left.is(Keywords.kw_assert) && Style.Language == FormatStyle::LK_Java)
3087     return true;
3088   if (Style.ObjCSpaceAfterProperty && Line.Type == LT_ObjCProperty &&
3089       Left.Tok.getObjCKeywordID() == tok::objc_property)
3090     return true;
3091   if (Right.is(tok::hashhash))
3092     return Left.is(tok::hash);
3093   if (Left.isOneOf(tok::hashhash, tok::hash))
3094     return Right.is(tok::hash);
3095   if ((Left.is(tok::l_paren) && Right.is(tok::r_paren)) ||
3096       (Left.is(tok::l_brace) && Left.isNot(BK_Block) &&
3097        Right.is(tok::r_brace) && Right.isNot(BK_Block)))
3098     return Style.SpaceInEmptyParentheses;
3099   if (Style.SpacesInConditionalStatement) {
3100     if (Left.is(tok::l_paren) && Left.Previous &&
3101         isKeywordWithCondition(*Left.Previous))
3102       return true;
3103     if (Right.is(tok::r_paren) && Right.MatchingParen &&
3104         Right.MatchingParen->Previous &&
3105         isKeywordWithCondition(*Right.MatchingParen->Previous))
3106       return true;
3107   }
3108 
3109   // auto{x} auto(x)
3110   if (Left.is(tok::kw_auto) && Right.isOneOf(tok::l_paren, tok::l_brace))
3111     return false;
3112 
3113   // operator co_await(x)
3114   if (Right.is(tok::l_paren) && Left.is(tok::kw_co_await) && Left.Previous &&
3115       Left.Previous->is(tok::kw_operator))
3116     return false;
3117   // co_await (x), co_yield (x), co_return (x)
3118   if (Left.isOneOf(tok::kw_co_await, tok::kw_co_yield, tok::kw_co_return) &&
3119       !Right.isOneOf(tok::semi, tok::r_paren))
3120     return true;
3121 
3122   if (Left.is(tok::l_paren) || Right.is(tok::r_paren))
3123     return (Right.is(TT_CastRParen) ||
3124             (Left.MatchingParen && Left.MatchingParen->is(TT_CastRParen)))
3125                ? Style.SpacesInCStyleCastParentheses
3126                : Style.SpacesInParentheses;
3127   if (Right.isOneOf(tok::semi, tok::comma))
3128     return false;
3129   if (Right.is(tok::less) && Line.Type == LT_ObjCDecl) {
3130     bool IsLightweightGeneric = Right.MatchingParen &&
3131                                 Right.MatchingParen->Next &&
3132                                 Right.MatchingParen->Next->is(tok::colon);
3133     return !IsLightweightGeneric && Style.ObjCSpaceBeforeProtocolList;
3134   }
3135   if (Right.is(tok::less) && Left.is(tok::kw_template))
3136     return Style.SpaceAfterTemplateKeyword;
3137   if (Left.isOneOf(tok::exclaim, tok::tilde))
3138     return false;
3139   if (Left.is(tok::at) &&
3140       Right.isOneOf(tok::identifier, tok::string_literal, tok::char_constant,
3141                     tok::numeric_constant, tok::l_paren, tok::l_brace,
3142                     tok::kw_true, tok::kw_false))
3143     return false;
3144   if (Left.is(tok::colon))
3145     return !Left.is(TT_ObjCMethodExpr);
3146   if (Left.is(tok::coloncolon))
3147     return false;
3148   if (Left.is(tok::less) || Right.isOneOf(tok::greater, tok::less)) {
3149     if (Style.Language == FormatStyle::LK_TextProto ||
3150         (Style.Language == FormatStyle::LK_Proto &&
3151          (Left.is(TT_DictLiteral) || Right.is(TT_DictLiteral)))) {
3152       // Format empty list as `<>`.
3153       if (Left.is(tok::less) && Right.is(tok::greater))
3154         return false;
3155       return !Style.Cpp11BracedListStyle;
3156     }
3157     return false;
3158   }
3159   if (Right.is(tok::ellipsis))
3160     return Left.Tok.isLiteral() || (Left.is(tok::identifier) && Left.Previous &&
3161                                     Left.Previous->is(tok::kw_case));
3162   if (Left.is(tok::l_square) && Right.is(tok::amp))
3163     return Style.SpacesInSquareBrackets;
3164   if (Right.is(TT_PointerOrReference)) {
3165     if (Left.is(tok::r_paren) && Line.MightBeFunctionDecl) {
3166       if (!Left.MatchingParen)
3167         return true;
3168       FormatToken *TokenBeforeMatchingParen =
3169           Left.MatchingParen->getPreviousNonComment();
3170       if (!TokenBeforeMatchingParen || !Left.is(TT_TypeDeclarationParen))
3171         return true;
3172     }
3173     // Add a space if the previous token is a pointer qualifier or the closing
3174     // parenthesis of __attribute__(()) expression and the style requires spaces
3175     // after pointer qualifiers.
3176     if ((Style.SpaceAroundPointerQualifiers == FormatStyle::SAPQ_After ||
3177          Style.SpaceAroundPointerQualifiers == FormatStyle::SAPQ_Both) &&
3178         (Left.is(TT_AttributeParen) || Left.canBePointerOrReferenceQualifier()))
3179       return true;
3180     if (Left.Tok.isLiteral())
3181       return true;
3182     // for (auto a = 0, b = 0; const auto & c : {1, 2, 3})
3183     if (Left.isTypeOrIdentifier() && Right.Next && Right.Next->Next &&
3184         Right.Next->Next->is(TT_RangeBasedForLoopColon))
3185       return getTokenPointerOrReferenceAlignment(Right) !=
3186              FormatStyle::PAS_Left;
3187     return !Left.isOneOf(TT_PointerOrReference, tok::l_paren) &&
3188            (getTokenPointerOrReferenceAlignment(Right) !=
3189                 FormatStyle::PAS_Left ||
3190             (Line.IsMultiVariableDeclStmt &&
3191              (Left.NestingLevel == 0 ||
3192               (Left.NestingLevel == 1 && startsWithInitStatement(Line)))));
3193   }
3194   if (Right.is(TT_FunctionTypeLParen) && Left.isNot(tok::l_paren) &&
3195       (!Left.is(TT_PointerOrReference) ||
3196        (getTokenPointerOrReferenceAlignment(Left) != FormatStyle::PAS_Right &&
3197         !Line.IsMultiVariableDeclStmt)))
3198     return true;
3199   if (Left.is(TT_PointerOrReference)) {
3200     // Add a space if the next token is a pointer qualifier and the style
3201     // requires spaces before pointer qualifiers.
3202     if ((Style.SpaceAroundPointerQualifiers == FormatStyle::SAPQ_Before ||
3203          Style.SpaceAroundPointerQualifiers == FormatStyle::SAPQ_Both) &&
3204         Right.canBePointerOrReferenceQualifier())
3205       return true;
3206     // & 1
3207     if (Right.Tok.isLiteral())
3208       return true;
3209     // & /* comment
3210     if (Right.is(TT_BlockComment))
3211       return true;
3212     // foo() -> const Bar * override/final
3213     if (Right.isOneOf(Keywords.kw_override, Keywords.kw_final) &&
3214         !Right.is(TT_StartOfName))
3215       return true;
3216     // & {
3217     if (Right.is(tok::l_brace) && Right.is(BK_Block))
3218       return true;
3219     // for (auto a = 0, b = 0; const auto& c : {1, 2, 3})
3220     if (Left.Previous && Left.Previous->isTypeOrIdentifier() && Right.Next &&
3221         Right.Next->is(TT_RangeBasedForLoopColon))
3222       return getTokenPointerOrReferenceAlignment(Left) !=
3223              FormatStyle::PAS_Right;
3224     if (Right.isOneOf(TT_PointerOrReference, TT_ArraySubscriptLSquare,
3225                       tok::l_paren))
3226       return false;
3227     if (getTokenPointerOrReferenceAlignment(Left) == FormatStyle::PAS_Right)
3228       return false;
3229     // FIXME: Setting IsMultiVariableDeclStmt for the whole line is error-prone,
3230     // because it does not take into account nested scopes like lambdas.
3231     // In multi-variable declaration statements, attach */& to the variable
3232     // independently of the style. However, avoid doing it if we are in a nested
3233     // scope, e.g. lambda. We still need to special-case statements with
3234     // initializers.
3235     if (Line.IsMultiVariableDeclStmt &&
3236         (Left.NestingLevel == Line.First->NestingLevel ||
3237          ((Left.NestingLevel == Line.First->NestingLevel + 1) &&
3238           startsWithInitStatement(Line))))
3239       return false;
3240     return Left.Previous && !Left.Previous->isOneOf(
3241                                 tok::l_paren, tok::coloncolon, tok::l_square);
3242   }
3243   // Ensure right pointer alignment with ellipsis e.g. int *...P
3244   if (Left.is(tok::ellipsis) && Left.Previous &&
3245       Left.Previous->isOneOf(tok::star, tok::amp, tok::ampamp))
3246     return Style.PointerAlignment != FormatStyle::PAS_Right;
3247 
3248   if (Right.is(tok::star) && Left.is(tok::l_paren))
3249     return false;
3250   if (Left.is(tok::star) && Right.isOneOf(tok::star, tok::amp, tok::ampamp))
3251     return false;
3252   if (Right.isOneOf(tok::star, tok::amp, tok::ampamp)) {
3253     const FormatToken *Previous = &Left;
3254     while (Previous && !Previous->is(tok::kw_operator)) {
3255       if (Previous->is(tok::identifier) || Previous->isSimpleTypeSpecifier()) {
3256         Previous = Previous->getPreviousNonComment();
3257         continue;
3258       }
3259       if (Previous->is(TT_TemplateCloser) && Previous->MatchingParen) {
3260         Previous = Previous->MatchingParen->getPreviousNonComment();
3261         continue;
3262       }
3263       if (Previous->is(tok::coloncolon)) {
3264         Previous = Previous->getPreviousNonComment();
3265         continue;
3266       }
3267       break;
3268     }
3269     // Space between the type and the * in:
3270     //   operator void*()
3271     //   operator char*()
3272     //   operator void const*()
3273     //   operator void volatile*()
3274     //   operator /*comment*/ const char*()
3275     //   operator volatile /*comment*/ char*()
3276     //   operator Foo*()
3277     //   operator C<T>*()
3278     //   operator std::Foo*()
3279     //   operator C<T>::D<U>*()
3280     // dependent on PointerAlignment style.
3281     if (Previous) {
3282       if (Previous->endsSequence(tok::kw_operator))
3283         return Style.PointerAlignment != FormatStyle::PAS_Left;
3284       if (Previous->is(tok::kw_const) || Previous->is(tok::kw_volatile))
3285         return (Style.PointerAlignment != FormatStyle::PAS_Left) ||
3286                (Style.SpaceAroundPointerQualifiers ==
3287                 FormatStyle::SAPQ_After) ||
3288                (Style.SpaceAroundPointerQualifiers == FormatStyle::SAPQ_Both);
3289     }
3290   }
3291   const auto SpaceRequiredForArrayInitializerLSquare =
3292       [](const FormatToken &LSquareTok, const FormatStyle &Style) {
3293         return Style.SpacesInContainerLiterals ||
3294                ((Style.Language == FormatStyle::LK_Proto ||
3295                  Style.Language == FormatStyle::LK_TextProto) &&
3296                 !Style.Cpp11BracedListStyle &&
3297                 LSquareTok.endsSequence(tok::l_square, tok::colon,
3298                                         TT_SelectorName));
3299       };
3300   if (Left.is(tok::l_square))
3301     return (Left.is(TT_ArrayInitializerLSquare) && Right.isNot(tok::r_square) &&
3302             SpaceRequiredForArrayInitializerLSquare(Left, Style)) ||
3303            (Left.isOneOf(TT_ArraySubscriptLSquare, TT_StructuredBindingLSquare,
3304                          TT_LambdaLSquare) &&
3305             Style.SpacesInSquareBrackets && Right.isNot(tok::r_square));
3306   if (Right.is(tok::r_square))
3307     return Right.MatchingParen &&
3308            ((Right.MatchingParen->is(TT_ArrayInitializerLSquare) &&
3309              SpaceRequiredForArrayInitializerLSquare(*Right.MatchingParen,
3310                                                      Style)) ||
3311             (Style.SpacesInSquareBrackets &&
3312              Right.MatchingParen->isOneOf(TT_ArraySubscriptLSquare,
3313                                           TT_StructuredBindingLSquare,
3314                                           TT_LambdaLSquare)) ||
3315             Right.MatchingParen->is(TT_AttributeParen));
3316   if (Right.is(tok::l_square) &&
3317       !Right.isOneOf(TT_ObjCMethodExpr, TT_LambdaLSquare,
3318                      TT_DesignatedInitializerLSquare,
3319                      TT_StructuredBindingLSquare, TT_AttributeSquare) &&
3320       !Left.isOneOf(tok::numeric_constant, TT_DictLiteral) &&
3321       !(!Left.is(tok::r_square) && Style.SpaceBeforeSquareBrackets &&
3322         Right.is(TT_ArraySubscriptLSquare)))
3323     return false;
3324   if (Left.is(tok::l_brace) && Right.is(tok::r_brace))
3325     return !Left.Children.empty(); // No spaces in "{}".
3326   if ((Left.is(tok::l_brace) && Left.isNot(BK_Block)) ||
3327       (Right.is(tok::r_brace) && Right.MatchingParen &&
3328        Right.MatchingParen->isNot(BK_Block)))
3329     return Style.Cpp11BracedListStyle ? Style.SpacesInParentheses : true;
3330   if (Left.is(TT_BlockComment))
3331     // No whitespace in x(/*foo=*/1), except for JavaScript.
3332     return Style.isJavaScript() || !Left.TokenText.endswith("=*/");
3333 
3334   // Space between template and attribute.
3335   // e.g. template <typename T> [[nodiscard]] ...
3336   if (Left.is(TT_TemplateCloser) && Right.is(TT_AttributeSquare))
3337     return true;
3338   // Space before parentheses common for all languages
3339   if (Right.is(tok::l_paren)) {
3340     if (Left.is(TT_TemplateCloser) && Right.isNot(TT_FunctionTypeLParen))
3341       return spaceRequiredBeforeParens(Right);
3342     if (Left.isOneOf(TT_RequiresClause, TT_RequiresClauseInARequiresExpression))
3343       return Style.SpaceBeforeParensOptions.AfterRequiresInClause ||
3344              spaceRequiredBeforeParens(Right);
3345     if (Left.is(TT_RequiresExpression))
3346       return Style.SpaceBeforeParensOptions.AfterRequiresInExpression ||
3347              spaceRequiredBeforeParens(Right);
3348     if ((Left.is(tok::r_paren) && Left.is(TT_AttributeParen)) ||
3349         (Left.is(tok::r_square) && Left.is(TT_AttributeSquare)))
3350       return true;
3351     if (Left.is(TT_ForEachMacro))
3352       return Style.SpaceBeforeParensOptions.AfterForeachMacros ||
3353              spaceRequiredBeforeParens(Right);
3354     if (Left.is(TT_IfMacro))
3355       return Style.SpaceBeforeParensOptions.AfterIfMacros ||
3356              spaceRequiredBeforeParens(Right);
3357     if (Line.Type == LT_ObjCDecl)
3358       return true;
3359     if (Left.is(tok::semi))
3360       return true;
3361     if (Left.isOneOf(tok::pp_elif, tok::kw_for, tok::kw_while, tok::kw_switch,
3362                      tok::kw_case, TT_ForEachMacro, TT_ObjCForIn))
3363       return Style.SpaceBeforeParensOptions.AfterControlStatements ||
3364              spaceRequiredBeforeParens(Right);
3365     if (Left.isIf(Line.Type != LT_PreprocessorDirective))
3366       return Style.SpaceBeforeParensOptions.AfterControlStatements ||
3367              spaceRequiredBeforeParens(Right);
3368 
3369     // TODO add Operator overloading specific Options to
3370     // SpaceBeforeParensOptions
3371     if (Right.is(TT_OverloadedOperatorLParen))
3372       return spaceRequiredBeforeParens(Right);
3373     // Function declaration or definition
3374     if (Line.MightBeFunctionDecl && (Left.is(TT_FunctionDeclarationName))) {
3375       if (Line.mightBeFunctionDefinition())
3376         return Style.SpaceBeforeParensOptions.AfterFunctionDefinitionName ||
3377                spaceRequiredBeforeParens(Right);
3378       else
3379         return Style.SpaceBeforeParensOptions.AfterFunctionDeclarationName ||
3380                spaceRequiredBeforeParens(Right);
3381     }
3382     // Lambda
3383     if (Line.Type != LT_PreprocessorDirective && Left.is(tok::r_square) &&
3384         Left.MatchingParen && Left.MatchingParen->is(TT_LambdaLSquare))
3385       return Style.SpaceBeforeParensOptions.AfterFunctionDefinitionName ||
3386              spaceRequiredBeforeParens(Right);
3387     if (!Left.Previous || Left.Previous->isNot(tok::period)) {
3388       if (Left.isOneOf(tok::kw_try, Keywords.kw___except, tok::kw_catch))
3389         return Style.SpaceBeforeParensOptions.AfterControlStatements ||
3390                spaceRequiredBeforeParens(Right);
3391       if (Left.isOneOf(tok::kw_new, tok::kw_delete))
3392         return ((!Line.MightBeFunctionDecl || !Left.Previous) &&
3393                 Style.SpaceBeforeParens != FormatStyle::SBPO_Never) ||
3394                spaceRequiredBeforeParens(Right);
3395 
3396       if (Left.is(tok::r_square) && Left.MatchingParen &&
3397           Left.MatchingParen->Previous &&
3398           Left.MatchingParen->Previous->is(tok::kw_delete))
3399         return (Style.SpaceBeforeParens != FormatStyle::SBPO_Never) ||
3400                spaceRequiredBeforeParens(Right);
3401     }
3402     if (Line.Type != LT_PreprocessorDirective &&
3403         (Left.is(tok::identifier) || Left.isFunctionLikeKeyword() ||
3404          Left.is(tok::r_paren) || Left.isSimpleTypeSpecifier()))
3405       return spaceRequiredBeforeParens(Right);
3406     return false;
3407   }
3408   if (Left.is(tok::at) && Right.Tok.getObjCKeywordID() != tok::objc_not_keyword)
3409     return false;
3410   if (Right.is(TT_UnaryOperator))
3411     return !Left.isOneOf(tok::l_paren, tok::l_square, tok::at) &&
3412            (Left.isNot(tok::colon) || Left.isNot(TT_ObjCMethodExpr));
3413   if ((Left.isOneOf(tok::identifier, tok::greater, tok::r_square,
3414                     tok::r_paren) ||
3415        Left.isSimpleTypeSpecifier()) &&
3416       Right.is(tok::l_brace) && Right.getNextNonComment() &&
3417       Right.isNot(BK_Block))
3418     return false;
3419   if (Left.is(tok::period) || Right.is(tok::period))
3420     return false;
3421   // u#str, U#str, L#str, u8#str
3422   // uR#str, UR#str, LR#str, u8R#str
3423   if (Right.is(tok::hash) && Left.is(tok::identifier) &&
3424       (Left.TokenText == "L" || Left.TokenText == "u" ||
3425        Left.TokenText == "U" || Left.TokenText == "u8" ||
3426        Left.TokenText == "LR" || Left.TokenText == "uR" ||
3427        Left.TokenText == "UR" || Left.TokenText == "u8R"))
3428     return false;
3429   if (Left.is(TT_TemplateCloser) && Left.MatchingParen &&
3430       Left.MatchingParen->Previous &&
3431       (Left.MatchingParen->Previous->is(tok::period) ||
3432        Left.MatchingParen->Previous->is(tok::coloncolon)))
3433     // Java call to generic function with explicit type:
3434     // A.<B<C<...>>>DoSomething();
3435     // A::<B<C<...>>>DoSomething();  // With a Java 8 method reference.
3436     return false;
3437   if (Left.is(TT_TemplateCloser) && Right.is(tok::l_square))
3438     return false;
3439   if (Left.is(tok::l_brace) && Left.endsSequence(TT_DictLiteral, tok::at))
3440     // Objective-C dictionary literal -> no space after opening brace.
3441     return false;
3442   if (Right.is(tok::r_brace) && Right.MatchingParen &&
3443       Right.MatchingParen->endsSequence(TT_DictLiteral, tok::at))
3444     // Objective-C dictionary literal -> no space before closing brace.
3445     return false;
3446   if (Right.getType() == TT_TrailingAnnotation &&
3447       Right.isOneOf(tok::amp, tok::ampamp) &&
3448       Left.isOneOf(tok::kw_const, tok::kw_volatile) &&
3449       (!Right.Next || Right.Next->is(tok::semi)))
3450     // Match const and volatile ref-qualifiers without any additional
3451     // qualifiers such as
3452     // void Fn() const &;
3453     return getTokenReferenceAlignment(Right) != FormatStyle::PAS_Left;
3454 
3455   return true;
3456 }
3457 
3458 bool TokenAnnotator::spaceRequiredBefore(const AnnotatedLine &Line,
3459                                          const FormatToken &Right) {
3460   const FormatToken &Left = *Right.Previous;
3461 
3462   // If the token is finalized don't touch it (as it could be in a
3463   // clang-format-off section).
3464   if (Left.Finalized)
3465     return Right.hasWhitespaceBefore();
3466 
3467   if (Right.Tok.getIdentifierInfo() && Left.Tok.getIdentifierInfo())
3468     return true; // Never ever merge two identifiers.
3469 
3470   // Leave a space between * and /* to avoid C4138 `comment end` found outside
3471   // of comment.
3472   if (Left.is(tok::star) && Right.is(tok::comment))
3473     return true;
3474 
3475   if (Style.isCpp()) {
3476     // Space between import <iostream>.
3477     // or import .....;
3478     if (Left.is(Keywords.kw_import) && Right.isOneOf(tok::less, tok::ellipsis))
3479       return true;
3480     // Space between `module :` and `import :`.
3481     if (Left.isOneOf(Keywords.kw_module, Keywords.kw_import) &&
3482         Right.is(TT_ModulePartitionColon))
3483       return true;
3484     // No space between import foo:bar but keep a space between import :bar;
3485     if (Left.is(tok::identifier) && Right.is(TT_ModulePartitionColon))
3486       return false;
3487     // No space between :bar;
3488     if (Left.is(TT_ModulePartitionColon) &&
3489         Right.isOneOf(tok::identifier, tok::kw_private))
3490       return false;
3491     if (Left.is(tok::ellipsis) && Right.is(tok::identifier) &&
3492         Line.First->is(Keywords.kw_import))
3493       return false;
3494     // Space in __attribute__((attr)) ::type.
3495     if (Left.is(TT_AttributeParen) && Right.is(tok::coloncolon))
3496       return true;
3497 
3498     if (Left.is(tok::kw_operator))
3499       return Right.is(tok::coloncolon);
3500     if (Right.is(tok::l_brace) && Right.is(BK_BracedInit) &&
3501         !Left.opensScope() && Style.SpaceBeforeCpp11BracedList)
3502       return true;
3503     if (Left.is(tok::less) && Left.is(TT_OverloadedOperator) &&
3504         Right.is(TT_TemplateOpener))
3505       return true;
3506   } else if (Style.Language == FormatStyle::LK_Proto ||
3507              Style.Language == FormatStyle::LK_TextProto) {
3508     if (Right.is(tok::period) &&
3509         Left.isOneOf(Keywords.kw_optional, Keywords.kw_required,
3510                      Keywords.kw_repeated, Keywords.kw_extend))
3511       return true;
3512     if (Right.is(tok::l_paren) &&
3513         Left.isOneOf(Keywords.kw_returns, Keywords.kw_option))
3514       return true;
3515     if (Right.isOneOf(tok::l_brace, tok::less) && Left.is(TT_SelectorName))
3516       return true;
3517     // Slashes occur in text protocol extension syntax: [type/type] { ... }.
3518     if (Left.is(tok::slash) || Right.is(tok::slash))
3519       return false;
3520     if (Left.MatchingParen &&
3521         Left.MatchingParen->is(TT_ProtoExtensionLSquare) &&
3522         Right.isOneOf(tok::l_brace, tok::less))
3523       return !Style.Cpp11BracedListStyle;
3524     // A percent is probably part of a formatting specification, such as %lld.
3525     if (Left.is(tok::percent))
3526       return false;
3527     // Preserve the existence of a space before a percent for cases like 0x%04x
3528     // and "%d %d"
3529     if (Left.is(tok::numeric_constant) && Right.is(tok::percent))
3530       return Right.hasWhitespaceBefore();
3531   } else if (Style.isJson()) {
3532     if (Right.is(tok::colon))
3533       return false;
3534   } else if (Style.isCSharp()) {
3535     // Require spaces around '{' and  before '}' unless they appear in
3536     // interpolated strings. Interpolated strings are merged into a single token
3537     // so cannot have spaces inserted by this function.
3538 
3539     // No space between 'this' and '['
3540     if (Left.is(tok::kw_this) && Right.is(tok::l_square))
3541       return false;
3542 
3543     // No space between 'new' and '('
3544     if (Left.is(tok::kw_new) && Right.is(tok::l_paren))
3545       return false;
3546 
3547     // Space before { (including space within '{ {').
3548     if (Right.is(tok::l_brace))
3549       return true;
3550 
3551     // Spaces inside braces.
3552     if (Left.is(tok::l_brace) && Right.isNot(tok::r_brace))
3553       return true;
3554 
3555     if (Left.isNot(tok::l_brace) && Right.is(tok::r_brace))
3556       return true;
3557 
3558     // Spaces around '=>'.
3559     if (Left.is(TT_FatArrow) || Right.is(TT_FatArrow))
3560       return true;
3561 
3562     // No spaces around attribute target colons
3563     if (Left.is(TT_AttributeColon) || Right.is(TT_AttributeColon))
3564       return false;
3565 
3566     // space between type and variable e.g. Dictionary<string,string> foo;
3567     if (Left.is(TT_TemplateCloser) && Right.is(TT_StartOfName))
3568       return true;
3569 
3570     // spaces inside square brackets.
3571     if (Left.is(tok::l_square) || Right.is(tok::r_square))
3572       return Style.SpacesInSquareBrackets;
3573 
3574     // No space before ? in nullable types.
3575     if (Right.is(TT_CSharpNullable))
3576       return false;
3577 
3578     // No space before null forgiving '!'.
3579     if (Right.is(TT_NonNullAssertion))
3580       return false;
3581 
3582     // No space between consecutive commas '[,,]'.
3583     if (Left.is(tok::comma) && Right.is(tok::comma))
3584       return false;
3585 
3586     // space after var in `var (key, value)`
3587     if (Left.is(Keywords.kw_var) && Right.is(tok::l_paren))
3588       return true;
3589 
3590     // space between keywords and paren e.g. "using ("
3591     if (Right.is(tok::l_paren))
3592       if (Left.isOneOf(tok::kw_using, Keywords.kw_async, Keywords.kw_when,
3593                        Keywords.kw_lock))
3594         return Style.SpaceBeforeParensOptions.AfterControlStatements ||
3595                spaceRequiredBeforeParens(Right);
3596 
3597     // space between method modifier and opening parenthesis of a tuple return
3598     // type
3599     if (Left.isOneOf(tok::kw_public, tok::kw_private, tok::kw_protected,
3600                      tok::kw_virtual, tok::kw_extern, tok::kw_static,
3601                      Keywords.kw_internal, Keywords.kw_abstract,
3602                      Keywords.kw_sealed, Keywords.kw_override,
3603                      Keywords.kw_async, Keywords.kw_unsafe) &&
3604         Right.is(tok::l_paren))
3605       return true;
3606   } else if (Style.isJavaScript()) {
3607     if (Left.is(TT_FatArrow))
3608       return true;
3609     // for await ( ...
3610     if (Right.is(tok::l_paren) && Left.is(Keywords.kw_await) && Left.Previous &&
3611         Left.Previous->is(tok::kw_for))
3612       return true;
3613     if (Left.is(Keywords.kw_async) && Right.is(tok::l_paren) &&
3614         Right.MatchingParen) {
3615       const FormatToken *Next = Right.MatchingParen->getNextNonComment();
3616       // An async arrow function, for example: `x = async () => foo();`,
3617       // as opposed to calling a function called async: `x = async();`
3618       if (Next && Next->is(TT_FatArrow))
3619         return true;
3620     }
3621     if ((Left.is(TT_TemplateString) && Left.TokenText.endswith("${")) ||
3622         (Right.is(TT_TemplateString) && Right.TokenText.startswith("}")))
3623       return false;
3624     // In tagged template literals ("html`bar baz`"), there is no space between
3625     // the tag identifier and the template string.
3626     if (Keywords.IsJavaScriptIdentifier(Left,
3627                                         /* AcceptIdentifierName= */ false) &&
3628         Right.is(TT_TemplateString))
3629       return false;
3630     if (Right.is(tok::star) &&
3631         Left.isOneOf(Keywords.kw_function, Keywords.kw_yield))
3632       return false;
3633     if (Right.isOneOf(tok::l_brace, tok::l_square) &&
3634         Left.isOneOf(Keywords.kw_function, Keywords.kw_yield,
3635                      Keywords.kw_extends, Keywords.kw_implements))
3636       return true;
3637     if (Right.is(tok::l_paren)) {
3638       // JS methods can use some keywords as names (e.g. `delete()`).
3639       if (Line.MustBeDeclaration && Left.Tok.getIdentifierInfo())
3640         return false;
3641       // Valid JS method names can include keywords, e.g. `foo.delete()` or
3642       // `bar.instanceof()`. Recognize call positions by preceding period.
3643       if (Left.Previous && Left.Previous->is(tok::period) &&
3644           Left.Tok.getIdentifierInfo())
3645         return false;
3646       // Additional unary JavaScript operators that need a space after.
3647       if (Left.isOneOf(tok::kw_throw, Keywords.kw_await, Keywords.kw_typeof,
3648                        tok::kw_void))
3649         return true;
3650     }
3651     // `foo as const;` casts into a const type.
3652     if (Left.endsSequence(tok::kw_const, Keywords.kw_as))
3653       return false;
3654     if ((Left.isOneOf(Keywords.kw_let, Keywords.kw_var, Keywords.kw_in,
3655                       tok::kw_const) ||
3656          // "of" is only a keyword if it appears after another identifier
3657          // (e.g. as "const x of y" in a for loop), or after a destructuring
3658          // operation (const [x, y] of z, const {a, b} of c).
3659          (Left.is(Keywords.kw_of) && Left.Previous &&
3660           (Left.Previous->is(tok::identifier) ||
3661            Left.Previous->isOneOf(tok::r_square, tok::r_brace)))) &&
3662         (!Left.Previous || !Left.Previous->is(tok::period)))
3663       return true;
3664     if (Left.isOneOf(tok::kw_for, Keywords.kw_as) && Left.Previous &&
3665         Left.Previous->is(tok::period) && Right.is(tok::l_paren))
3666       return false;
3667     if (Left.is(Keywords.kw_as) &&
3668         Right.isOneOf(tok::l_square, tok::l_brace, tok::l_paren))
3669       return true;
3670     if (Left.is(tok::kw_default) && Left.Previous &&
3671         Left.Previous->is(tok::kw_export))
3672       return true;
3673     if (Left.is(Keywords.kw_is) && Right.is(tok::l_brace))
3674       return true;
3675     if (Right.isOneOf(TT_JsTypeColon, TT_JsTypeOptionalQuestion))
3676       return false;
3677     if (Left.is(TT_JsTypeOperator) || Right.is(TT_JsTypeOperator))
3678       return false;
3679     if ((Left.is(tok::l_brace) || Right.is(tok::r_brace)) &&
3680         Line.First->isOneOf(Keywords.kw_import, tok::kw_export))
3681       return false;
3682     if (Left.is(tok::ellipsis))
3683       return false;
3684     if (Left.is(TT_TemplateCloser) &&
3685         !Right.isOneOf(tok::equal, tok::l_brace, tok::comma, tok::l_square,
3686                        Keywords.kw_implements, Keywords.kw_extends))
3687       // Type assertions ('<type>expr') are not followed by whitespace. Other
3688       // locations that should have whitespace following are identified by the
3689       // above set of follower tokens.
3690       return false;
3691     if (Right.is(TT_NonNullAssertion))
3692       return false;
3693     if (Left.is(TT_NonNullAssertion) &&
3694         Right.isOneOf(Keywords.kw_as, Keywords.kw_in))
3695       return true; // "x! as string", "x! in y"
3696   } else if (Style.Language == FormatStyle::LK_Java) {
3697     if (Left.is(tok::r_square) && Right.is(tok::l_brace))
3698       return true;
3699     if (Left.is(Keywords.kw_synchronized) && Right.is(tok::l_paren))
3700       return Style.SpaceBeforeParensOptions.AfterControlStatements ||
3701              spaceRequiredBeforeParens(Right);
3702     if ((Left.isOneOf(tok::kw_static, tok::kw_public, tok::kw_private,
3703                       tok::kw_protected) ||
3704          Left.isOneOf(Keywords.kw_final, Keywords.kw_abstract,
3705                       Keywords.kw_native)) &&
3706         Right.is(TT_TemplateOpener))
3707       return true;
3708   }
3709   if (Left.is(TT_ImplicitStringLiteral))
3710     return Right.hasWhitespaceBefore();
3711   if (Line.Type == LT_ObjCMethodDecl) {
3712     if (Left.is(TT_ObjCMethodSpecifier))
3713       return true;
3714     if (Left.is(tok::r_paren) && canBeObjCSelectorComponent(Right))
3715       // Don't space between ')' and <id> or ')' and 'new'. 'new' is not a
3716       // keyword in Objective-C, and '+ (instancetype)new;' is a standard class
3717       // method declaration.
3718       return false;
3719   }
3720   if (Line.Type == LT_ObjCProperty &&
3721       (Right.is(tok::equal) || Left.is(tok::equal)))
3722     return false;
3723 
3724   if (Right.isOneOf(TT_TrailingReturnArrow, TT_LambdaArrow) ||
3725       Left.isOneOf(TT_TrailingReturnArrow, TT_LambdaArrow))
3726     return true;
3727   if (Left.is(tok::comma) && !Right.is(TT_OverloadedOperatorLParen))
3728     return true;
3729   if (Right.is(tok::comma))
3730     return false;
3731   if (Right.is(TT_ObjCBlockLParen))
3732     return true;
3733   if (Right.is(TT_CtorInitializerColon))
3734     return Style.SpaceBeforeCtorInitializerColon;
3735   if (Right.is(TT_InheritanceColon) && !Style.SpaceBeforeInheritanceColon)
3736     return false;
3737   if (Right.is(TT_RangeBasedForLoopColon) &&
3738       !Style.SpaceBeforeRangeBasedForLoopColon)
3739     return false;
3740   if (Left.is(TT_BitFieldColon))
3741     return Style.BitFieldColonSpacing == FormatStyle::BFCS_Both ||
3742            Style.BitFieldColonSpacing == FormatStyle::BFCS_After;
3743   if (Right.is(tok::colon)) {
3744     if (Line.First->isOneOf(tok::kw_default, tok::kw_case))
3745       return Style.SpaceBeforeCaseColon;
3746     const FormatToken *Next = Right.getNextNonComment();
3747     if (!Next || Next->is(tok::semi))
3748       return false;
3749     if (Right.is(TT_ObjCMethodExpr))
3750       return false;
3751     if (Left.is(tok::question))
3752       return false;
3753     if (Right.is(TT_InlineASMColon) && Left.is(tok::coloncolon))
3754       return false;
3755     if (Right.is(TT_DictLiteral))
3756       return Style.SpacesInContainerLiterals;
3757     if (Right.is(TT_AttributeColon))
3758       return false;
3759     if (Right.is(TT_CSharpNamedArgumentColon))
3760       return false;
3761     if (Right.is(TT_BitFieldColon))
3762       return Style.BitFieldColonSpacing == FormatStyle::BFCS_Both ||
3763              Style.BitFieldColonSpacing == FormatStyle::BFCS_Before;
3764     return true;
3765   }
3766   // Do not merge "- -" into "--".
3767   if ((Left.isOneOf(tok::minus, tok::minusminus) &&
3768        Right.isOneOf(tok::minus, tok::minusminus)) ||
3769       (Left.isOneOf(tok::plus, tok::plusplus) &&
3770        Right.isOneOf(tok::plus, tok::plusplus)))
3771     return true;
3772   if (Left.is(TT_UnaryOperator)) {
3773     if (!Right.is(tok::l_paren)) {
3774       // The alternative operators for ~ and ! are "compl" and "not".
3775       // If they are used instead, we do not want to combine them with
3776       // the token to the right, unless that is a left paren.
3777       if (Left.is(tok::exclaim) && Left.TokenText == "not")
3778         return true;
3779       if (Left.is(tok::tilde) && Left.TokenText == "compl")
3780         return true;
3781       // Lambda captures allow for a lone &, so "&]" needs to be properly
3782       // handled.
3783       if (Left.is(tok::amp) && Right.is(tok::r_square))
3784         return Style.SpacesInSquareBrackets;
3785     }
3786     return (Style.SpaceAfterLogicalNot && Left.is(tok::exclaim)) ||
3787            Right.is(TT_BinaryOperator);
3788   }
3789 
3790   // If the next token is a binary operator or a selector name, we have
3791   // incorrectly classified the parenthesis as a cast. FIXME: Detect correctly.
3792   if (Left.is(TT_CastRParen))
3793     return Style.SpaceAfterCStyleCast ||
3794            Right.isOneOf(TT_BinaryOperator, TT_SelectorName);
3795 
3796   auto ShouldAddSpacesInAngles = [this, &Right]() {
3797     if (this->Style.SpacesInAngles == FormatStyle::SIAS_Always)
3798       return true;
3799     if (this->Style.SpacesInAngles == FormatStyle::SIAS_Leave)
3800       return Right.hasWhitespaceBefore();
3801     return false;
3802   };
3803 
3804   if (Left.is(tok::greater) && Right.is(tok::greater)) {
3805     if (Style.Language == FormatStyle::LK_TextProto ||
3806         (Style.Language == FormatStyle::LK_Proto && Left.is(TT_DictLiteral)))
3807       return !Style.Cpp11BracedListStyle;
3808     return Right.is(TT_TemplateCloser) && Left.is(TT_TemplateCloser) &&
3809            ((Style.Standard < FormatStyle::LS_Cpp11) ||
3810             ShouldAddSpacesInAngles());
3811   }
3812   if (Right.isOneOf(tok::arrow, tok::arrowstar, tok::periodstar) ||
3813       Left.isOneOf(tok::arrow, tok::period, tok::arrowstar, tok::periodstar) ||
3814       (Right.is(tok::period) && Right.isNot(TT_DesignatedInitializerPeriod)))
3815     return false;
3816   if (!Style.SpaceBeforeAssignmentOperators && Left.isNot(TT_TemplateCloser) &&
3817       Right.getPrecedence() == prec::Assignment)
3818     return false;
3819   if (Style.Language == FormatStyle::LK_Java && Right.is(tok::coloncolon) &&
3820       (Left.is(tok::identifier) || Left.is(tok::kw_this)))
3821     return false;
3822   if (Right.is(tok::coloncolon) && Left.is(tok::identifier))
3823     // Generally don't remove existing spaces between an identifier and "::".
3824     // The identifier might actually be a macro name such as ALWAYS_INLINE. If
3825     // this turns out to be too lenient, add analysis of the identifier itself.
3826     return Right.hasWhitespaceBefore();
3827   if (Right.is(tok::coloncolon) &&
3828       !Left.isOneOf(tok::l_brace, tok::comment, tok::l_paren))
3829     // Put a space between < and :: in vector< ::std::string >
3830     return (Left.is(TT_TemplateOpener) &&
3831             ((Style.Standard < FormatStyle::LS_Cpp11) ||
3832              ShouldAddSpacesInAngles())) ||
3833            !(Left.isOneOf(tok::l_paren, tok::r_paren, tok::l_square,
3834                           tok::kw___super, TT_TemplateOpener,
3835                           TT_TemplateCloser)) ||
3836            (Left.is(tok::l_paren) && Style.SpacesInParentheses);
3837   if ((Left.is(TT_TemplateOpener)) != (Right.is(TT_TemplateCloser)))
3838     return ShouldAddSpacesInAngles();
3839   // Space before TT_StructuredBindingLSquare.
3840   if (Right.is(TT_StructuredBindingLSquare))
3841     return !Left.isOneOf(tok::amp, tok::ampamp) ||
3842            getTokenReferenceAlignment(Left) != FormatStyle::PAS_Right;
3843   // Space before & or && following a TT_StructuredBindingLSquare.
3844   if (Right.Next && Right.Next->is(TT_StructuredBindingLSquare) &&
3845       Right.isOneOf(tok::amp, tok::ampamp))
3846     return getTokenReferenceAlignment(Right) != FormatStyle::PAS_Left;
3847   if ((Right.is(TT_BinaryOperator) && !Left.is(tok::l_paren)) ||
3848       (Left.isOneOf(TT_BinaryOperator, TT_ConditionalExpr) &&
3849        !Right.is(tok::r_paren)))
3850     return true;
3851   if (Right.is(TT_TemplateOpener) && Left.is(tok::r_paren) &&
3852       Left.MatchingParen && Left.MatchingParen->is(TT_OverloadedOperatorLParen))
3853     return false;
3854   if (Right.is(tok::less) && Left.isNot(tok::l_paren) &&
3855       Line.startsWith(tok::hash))
3856     return true;
3857   if (Right.is(TT_TrailingUnaryOperator))
3858     return false;
3859   if (Left.is(TT_RegexLiteral))
3860     return false;
3861   return spaceRequiredBetween(Line, Left, Right);
3862 }
3863 
3864 // Returns 'true' if 'Tok' is a brace we'd want to break before in Allman style.
3865 static bool isAllmanBrace(const FormatToken &Tok) {
3866   return Tok.is(tok::l_brace) && Tok.is(BK_Block) &&
3867          !Tok.isOneOf(TT_ObjCBlockLBrace, TT_LambdaLBrace, TT_DictLiteral);
3868 }
3869 
3870 // Returns 'true' if 'Tok' is a function argument.
3871 static bool IsFunctionArgument(const FormatToken &Tok) {
3872   return Tok.MatchingParen && Tok.MatchingParen->Next &&
3873          Tok.MatchingParen->Next->isOneOf(tok::comma, tok::r_paren);
3874 }
3875 
3876 static bool
3877 isItAnEmptyLambdaAllowed(const FormatToken &Tok,
3878                          FormatStyle::ShortLambdaStyle ShortLambdaOption) {
3879   return Tok.Children.empty() && ShortLambdaOption != FormatStyle::SLS_None;
3880 }
3881 
3882 static bool isAllmanLambdaBrace(const FormatToken &Tok) {
3883   return Tok.is(tok::l_brace) && Tok.is(BK_Block) &&
3884          !Tok.isOneOf(TT_ObjCBlockLBrace, TT_DictLiteral);
3885 }
3886 
3887 // Returns the first token on the line that is not a comment.
3888 static const FormatToken *getFirstNonComment(const AnnotatedLine &Line) {
3889   const FormatToken *Next = Line.First;
3890   if (!Next)
3891     return Next;
3892   if (Next->is(tok::comment))
3893     Next = Next->getNextNonComment();
3894   return Next;
3895 }
3896 
3897 bool TokenAnnotator::mustBreakBefore(const AnnotatedLine &Line,
3898                                      const FormatToken &Right) {
3899   const FormatToken &Left = *Right.Previous;
3900   if (Right.NewlinesBefore > 1 && Style.MaxEmptyLinesToKeep > 0)
3901     return true;
3902 
3903   if (Style.isCSharp()) {
3904     if (Left.is(TT_FatArrow) && Right.is(tok::l_brace) &&
3905         Style.BraceWrapping.AfterFunction)
3906       return true;
3907     if (Right.is(TT_CSharpNamedArgumentColon) ||
3908         Left.is(TT_CSharpNamedArgumentColon))
3909       return false;
3910     if (Right.is(TT_CSharpGenericTypeConstraint))
3911       return true;
3912     if (Right.Next && Right.Next->is(TT_FatArrow) &&
3913         (Right.is(tok::numeric_constant) ||
3914          (Right.is(tok::identifier) && Right.TokenText == "_")))
3915       return true;
3916 
3917     // Break after C# [...] and before public/protected/private/internal.
3918     if (Left.is(TT_AttributeSquare) && Left.is(tok::r_square) &&
3919         (Right.isAccessSpecifier(/*ColonRequired=*/false) ||
3920          Right.is(Keywords.kw_internal)))
3921       return true;
3922     // Break between ] and [ but only when there are really 2 attributes.
3923     if (Left.is(TT_AttributeSquare) && Right.is(TT_AttributeSquare) &&
3924         Left.is(tok::r_square) && Right.is(tok::l_square))
3925       return true;
3926 
3927   } else if (Style.isJavaScript()) {
3928     // FIXME: This might apply to other languages and token kinds.
3929     if (Right.is(tok::string_literal) && Left.is(tok::plus) && Left.Previous &&
3930         Left.Previous->is(tok::string_literal))
3931       return true;
3932     if (Left.is(TT_DictLiteral) && Left.is(tok::l_brace) && Line.Level == 0 &&
3933         Left.Previous && Left.Previous->is(tok::equal) &&
3934         Line.First->isOneOf(tok::identifier, Keywords.kw_import, tok::kw_export,
3935                             tok::kw_const) &&
3936         // kw_var/kw_let are pseudo-tokens that are tok::identifier, so match
3937         // above.
3938         !Line.First->isOneOf(Keywords.kw_var, Keywords.kw_let))
3939       // Object literals on the top level of a file are treated as "enum-style".
3940       // Each key/value pair is put on a separate line, instead of bin-packing.
3941       return true;
3942     if (Left.is(tok::l_brace) && Line.Level == 0 &&
3943         (Line.startsWith(tok::kw_enum) ||
3944          Line.startsWith(tok::kw_const, tok::kw_enum) ||
3945          Line.startsWith(tok::kw_export, tok::kw_enum) ||
3946          Line.startsWith(tok::kw_export, tok::kw_const, tok::kw_enum)))
3947       // JavaScript top-level enum key/value pairs are put on separate lines
3948       // instead of bin-packing.
3949       return true;
3950     if (Right.is(tok::r_brace) && Left.is(tok::l_brace) && Left.Previous &&
3951         Left.Previous->is(TT_FatArrow)) {
3952       // JS arrow function (=> {...}).
3953       switch (Style.AllowShortLambdasOnASingleLine) {
3954       case FormatStyle::SLS_All:
3955         return false;
3956       case FormatStyle::SLS_None:
3957         return true;
3958       case FormatStyle::SLS_Empty:
3959         return !Left.Children.empty();
3960       case FormatStyle::SLS_Inline:
3961         // allow one-lining inline (e.g. in function call args) and empty arrow
3962         // functions.
3963         return (Left.NestingLevel == 0 && Line.Level == 0) &&
3964                !Left.Children.empty();
3965       }
3966       llvm_unreachable("Unknown FormatStyle::ShortLambdaStyle enum");
3967     }
3968 
3969     if (Right.is(tok::r_brace) && Left.is(tok::l_brace) &&
3970         !Left.Children.empty())
3971       // Support AllowShortFunctionsOnASingleLine for JavaScript.
3972       return Style.AllowShortFunctionsOnASingleLine == FormatStyle::SFS_None ||
3973              Style.AllowShortFunctionsOnASingleLine == FormatStyle::SFS_Empty ||
3974              (Left.NestingLevel == 0 && Line.Level == 0 &&
3975               Style.AllowShortFunctionsOnASingleLine &
3976                   FormatStyle::SFS_InlineOnly);
3977   } else if (Style.Language == FormatStyle::LK_Java) {
3978     if (Right.is(tok::plus) && Left.is(tok::string_literal) && Right.Next &&
3979         Right.Next->is(tok::string_literal))
3980       return true;
3981   } else if (Style.Language == FormatStyle::LK_Cpp ||
3982              Style.Language == FormatStyle::LK_ObjC ||
3983              Style.Language == FormatStyle::LK_Proto ||
3984              Style.Language == FormatStyle::LK_TableGen ||
3985              Style.Language == FormatStyle::LK_TextProto) {
3986     if (Left.isStringLiteral() && Right.isStringLiteral())
3987       return true;
3988   }
3989 
3990   // Basic JSON newline processing.
3991   if (Style.isJson()) {
3992     // Always break after a JSON record opener.
3993     // {
3994     // }
3995     if (Left.is(TT_DictLiteral) && Left.is(tok::l_brace))
3996       return true;
3997     // Always break after a JSON array opener.
3998     // [
3999     // ]
4000     if (Left.is(TT_ArrayInitializerLSquare) && Left.is(tok::l_square) &&
4001         !Right.is(tok::r_square))
4002       return true;
4003     // Always break after successive entries.
4004     // 1,
4005     // 2
4006     if (Left.is(tok::comma))
4007       return true;
4008   }
4009 
4010   // If the last token before a '}', ']', or ')' is a comma or a trailing
4011   // comment, the intention is to insert a line break after it in order to make
4012   // shuffling around entries easier. Import statements, especially in
4013   // JavaScript, can be an exception to this rule.
4014   if (Style.JavaScriptWrapImports || Line.Type != LT_ImportStatement) {
4015     const FormatToken *BeforeClosingBrace = nullptr;
4016     if ((Left.isOneOf(tok::l_brace, TT_ArrayInitializerLSquare) ||
4017          (Style.isJavaScript() && Left.is(tok::l_paren))) &&
4018         Left.isNot(BK_Block) && Left.MatchingParen)
4019       BeforeClosingBrace = Left.MatchingParen->Previous;
4020     else if (Right.MatchingParen &&
4021              (Right.MatchingParen->isOneOf(tok::l_brace,
4022                                            TT_ArrayInitializerLSquare) ||
4023               (Style.isJavaScript() && Right.MatchingParen->is(tok::l_paren))))
4024       BeforeClosingBrace = &Left;
4025     if (BeforeClosingBrace && (BeforeClosingBrace->is(tok::comma) ||
4026                                BeforeClosingBrace->isTrailingComment()))
4027       return true;
4028   }
4029 
4030   if (Right.is(tok::comment))
4031     return Left.isNot(BK_BracedInit) && Left.isNot(TT_CtorInitializerColon) &&
4032            (Right.NewlinesBefore > 0 && Right.HasUnescapedNewline);
4033   if (Left.isTrailingComment())
4034     return true;
4035   if (Left.IsUnterminatedLiteral)
4036     return true;
4037   if (Right.is(tok::lessless) && Right.Next && Left.is(tok::string_literal) &&
4038       Right.Next->is(tok::string_literal))
4039     return true;
4040   if (Right.is(TT_RequiresClause)) {
4041     switch (Style.RequiresClausePosition) {
4042     case FormatStyle::RCPS_OwnLine:
4043     case FormatStyle::RCPS_WithFollowing:
4044       return true;
4045     default:
4046       break;
4047     }
4048   }
4049   // Can break after template<> declaration
4050   if (Left.ClosesTemplateDeclaration && Left.MatchingParen &&
4051       Left.MatchingParen->NestingLevel == 0) {
4052     // Put concepts on the next line e.g.
4053     // template<typename T>
4054     // concept ...
4055     if (Right.is(tok::kw_concept))
4056       return Style.BreakBeforeConceptDeclarations == FormatStyle::BBCDS_Always;
4057     return Style.AlwaysBreakTemplateDeclarations == FormatStyle::BTDS_Yes;
4058   }
4059   if (Left.ClosesRequiresClause && Right.isNot(tok::semi)) {
4060     switch (Style.RequiresClausePosition) {
4061     case FormatStyle::RCPS_OwnLine:
4062     case FormatStyle::RCPS_WithPreceding:
4063       return true;
4064     default:
4065       break;
4066     }
4067   }
4068   if (Style.PackConstructorInitializers == FormatStyle::PCIS_Never) {
4069     if (Style.BreakConstructorInitializers == FormatStyle::BCIS_BeforeColon &&
4070         (Left.is(TT_CtorInitializerComma) || Right.is(TT_CtorInitializerColon)))
4071       return true;
4072 
4073     if (Style.BreakConstructorInitializers == FormatStyle::BCIS_AfterColon &&
4074         Left.isOneOf(TT_CtorInitializerColon, TT_CtorInitializerComma))
4075       return true;
4076   }
4077   if (Style.PackConstructorInitializers < FormatStyle::PCIS_CurrentLine &&
4078       Style.BreakConstructorInitializers == FormatStyle::BCIS_BeforeComma &&
4079       Right.isOneOf(TT_CtorInitializerComma, TT_CtorInitializerColon))
4080     return true;
4081   // Break only if we have multiple inheritance.
4082   if (Style.BreakInheritanceList == FormatStyle::BILS_BeforeComma &&
4083       Right.is(TT_InheritanceComma))
4084     return true;
4085   if (Style.BreakInheritanceList == FormatStyle::BILS_AfterComma &&
4086       Left.is(TT_InheritanceComma))
4087     return true;
4088   if (Right.is(tok::string_literal) && Right.TokenText.startswith("R\""))
4089     // Multiline raw string literals are special wrt. line breaks. The author
4090     // has made a deliberate choice and might have aligned the contents of the
4091     // string literal accordingly. Thus, we try keep existing line breaks.
4092     return Right.IsMultiline && Right.NewlinesBefore > 0;
4093   if ((Left.is(tok::l_brace) || (Left.is(tok::less) && Left.Previous &&
4094                                  Left.Previous->is(tok::equal))) &&
4095       Right.NestingLevel == 1 && Style.Language == FormatStyle::LK_Proto) {
4096     // Don't put enums or option definitions onto single lines in protocol
4097     // buffers.
4098     return true;
4099   }
4100   if (Right.is(TT_InlineASMBrace))
4101     return Right.HasUnescapedNewline;
4102 
4103   if (isAllmanBrace(Left) || isAllmanBrace(Right)) {
4104     auto FirstNonComment = getFirstNonComment(Line);
4105     bool AccessSpecifier =
4106         FirstNonComment &&
4107         FirstNonComment->isOneOf(Keywords.kw_internal, tok::kw_public,
4108                                  tok::kw_private, tok::kw_protected);
4109 
4110     if (Style.BraceWrapping.AfterEnum) {
4111       if (Line.startsWith(tok::kw_enum) ||
4112           Line.startsWith(tok::kw_typedef, tok::kw_enum))
4113         return true;
4114       // Ensure BraceWrapping for `public enum A {`.
4115       if (AccessSpecifier && FirstNonComment->Next &&
4116           FirstNonComment->Next->is(tok::kw_enum))
4117         return true;
4118     }
4119 
4120     // Ensure BraceWrapping for `public interface A {`.
4121     if (Style.BraceWrapping.AfterClass &&
4122         ((AccessSpecifier && FirstNonComment->Next &&
4123           FirstNonComment->Next->is(Keywords.kw_interface)) ||
4124          Line.startsWith(Keywords.kw_interface)))
4125       return true;
4126 
4127     return (Line.startsWith(tok::kw_class) && Style.BraceWrapping.AfterClass) ||
4128            (Line.startsWith(tok::kw_struct) && Style.BraceWrapping.AfterStruct);
4129   }
4130 
4131   if (Left.is(TT_ObjCBlockLBrace) &&
4132       Style.AllowShortBlocksOnASingleLine == FormatStyle::SBS_Never)
4133     return true;
4134 
4135   // Ensure wrapping after __attribute__((XX)) and @interface etc.
4136   if (Left.is(TT_AttributeParen) && Right.is(TT_ObjCDecl))
4137     return true;
4138 
4139   if (Left.is(TT_LambdaLBrace)) {
4140     if (IsFunctionArgument(Left) &&
4141         Style.AllowShortLambdasOnASingleLine == FormatStyle::SLS_Inline)
4142       return false;
4143 
4144     if (Style.AllowShortLambdasOnASingleLine == FormatStyle::SLS_None ||
4145         Style.AllowShortLambdasOnASingleLine == FormatStyle::SLS_Inline ||
4146         (!Left.Children.empty() &&
4147          Style.AllowShortLambdasOnASingleLine == FormatStyle::SLS_Empty))
4148       return true;
4149   }
4150 
4151   if (Style.BraceWrapping.BeforeLambdaBody && Right.is(TT_LambdaLBrace) &&
4152       Left.isOneOf(tok::star, tok::amp, tok::ampamp, TT_TemplateCloser))
4153     return true;
4154 
4155   // Put multiple Java annotation on a new line.
4156   if ((Style.Language == FormatStyle::LK_Java || Style.isJavaScript()) &&
4157       Left.is(TT_LeadingJavaAnnotation) &&
4158       Right.isNot(TT_LeadingJavaAnnotation) && Right.isNot(tok::l_paren) &&
4159       (Line.Last->is(tok::l_brace) || Style.BreakAfterJavaFieldAnnotations))
4160     return true;
4161 
4162   if (Right.is(TT_ProtoExtensionLSquare))
4163     return true;
4164 
4165   // In text proto instances if a submessage contains at least 2 entries and at
4166   // least one of them is a submessage, like A { ... B { ... } ... },
4167   // put all of the entries of A on separate lines by forcing the selector of
4168   // the submessage B to be put on a newline.
4169   //
4170   // Example: these can stay on one line:
4171   // a { scalar_1: 1 scalar_2: 2 }
4172   // a { b { key: value } }
4173   //
4174   // and these entries need to be on a new line even if putting them all in one
4175   // line is under the column limit:
4176   // a {
4177   //   scalar: 1
4178   //   b { key: value }
4179   // }
4180   //
4181   // We enforce this by breaking before a submessage field that has previous
4182   // siblings, *and* breaking before a field that follows a submessage field.
4183   //
4184   // Be careful to exclude the case  [proto.ext] { ... } since the `]` is
4185   // the TT_SelectorName there, but we don't want to break inside the brackets.
4186   //
4187   // Another edge case is @submessage { key: value }, which is a common
4188   // substitution placeholder. In this case we want to keep `@` and `submessage`
4189   // together.
4190   //
4191   // We ensure elsewhere that extensions are always on their own line.
4192   if ((Style.Language == FormatStyle::LK_Proto ||
4193        Style.Language == FormatStyle::LK_TextProto) &&
4194       Right.is(TT_SelectorName) && !Right.is(tok::r_square) && Right.Next) {
4195     // Keep `@submessage` together in:
4196     // @submessage { key: value }
4197     if (Left.is(tok::at))
4198       return false;
4199     // Look for the scope opener after selector in cases like:
4200     // selector { ...
4201     // selector: { ...
4202     // selector: @base { ...
4203     FormatToken *LBrace = Right.Next;
4204     if (LBrace && LBrace->is(tok::colon)) {
4205       LBrace = LBrace->Next;
4206       if (LBrace && LBrace->is(tok::at)) {
4207         LBrace = LBrace->Next;
4208         if (LBrace)
4209           LBrace = LBrace->Next;
4210       }
4211     }
4212     if (LBrace &&
4213         // The scope opener is one of {, [, <:
4214         // selector { ... }
4215         // selector [ ... ]
4216         // selector < ... >
4217         //
4218         // In case of selector { ... }, the l_brace is TT_DictLiteral.
4219         // In case of an empty selector {}, the l_brace is not TT_DictLiteral,
4220         // so we check for immediately following r_brace.
4221         ((LBrace->is(tok::l_brace) &&
4222           (LBrace->is(TT_DictLiteral) ||
4223            (LBrace->Next && LBrace->Next->is(tok::r_brace)))) ||
4224          LBrace->is(TT_ArrayInitializerLSquare) || LBrace->is(tok::less))) {
4225       // If Left.ParameterCount is 0, then this submessage entry is not the
4226       // first in its parent submessage, and we want to break before this entry.
4227       // If Left.ParameterCount is greater than 0, then its parent submessage
4228       // might contain 1 or more entries and we want to break before this entry
4229       // if it contains at least 2 entries. We deal with this case later by
4230       // detecting and breaking before the next entry in the parent submessage.
4231       if (Left.ParameterCount == 0)
4232         return true;
4233       // However, if this submessage is the first entry in its parent
4234       // submessage, Left.ParameterCount might be 1 in some cases.
4235       // We deal with this case later by detecting an entry
4236       // following a closing paren of this submessage.
4237     }
4238 
4239     // If this is an entry immediately following a submessage, it will be
4240     // preceded by a closing paren of that submessage, like in:
4241     //     left---.  .---right
4242     //            v  v
4243     // sub: { ... } key: value
4244     // If there was a comment between `}` an `key` above, then `key` would be
4245     // put on a new line anyways.
4246     if (Left.isOneOf(tok::r_brace, tok::greater, tok::r_square))
4247       return true;
4248   }
4249 
4250   // Deal with lambda arguments in C++ - we want consistent line breaks whether
4251   // they happen to be at arg0, arg1 or argN. The selection is a bit nuanced
4252   // as aggressive line breaks are placed when the lambda is not the last arg.
4253   if ((Style.Language == FormatStyle::LK_Cpp ||
4254        Style.Language == FormatStyle::LK_ObjC) &&
4255       Left.is(tok::l_paren) && Left.BlockParameterCount > 0 &&
4256       !Right.isOneOf(tok::l_paren, TT_LambdaLSquare)) {
4257     // Multiple lambdas in the same function call force line breaks.
4258     if (Left.BlockParameterCount > 1)
4259       return true;
4260 
4261     // A lambda followed by another arg forces a line break.
4262     if (!Left.Role)
4263       return false;
4264     auto Comma = Left.Role->lastComma();
4265     if (!Comma)
4266       return false;
4267     auto Next = Comma->getNextNonComment();
4268     if (!Next)
4269       return false;
4270     if (!Next->isOneOf(TT_LambdaLSquare, tok::l_brace, tok::caret))
4271       return true;
4272   }
4273 
4274   return false;
4275 }
4276 
4277 bool TokenAnnotator::canBreakBefore(const AnnotatedLine &Line,
4278                                     const FormatToken &Right) {
4279   const FormatToken &Left = *Right.Previous;
4280   // Language-specific stuff.
4281   if (Style.isCSharp()) {
4282     if (Left.isOneOf(TT_CSharpNamedArgumentColon, TT_AttributeColon) ||
4283         Right.isOneOf(TT_CSharpNamedArgumentColon, TT_AttributeColon))
4284       return false;
4285     // Only break after commas for generic type constraints.
4286     if (Line.First->is(TT_CSharpGenericTypeConstraint))
4287       return Left.is(TT_CSharpGenericTypeConstraintComma);
4288     // Keep nullable operators attached to their identifiers.
4289     if (Right.is(TT_CSharpNullable))
4290       return false;
4291   } else if (Style.Language == FormatStyle::LK_Java) {
4292     if (Left.isOneOf(Keywords.kw_throws, Keywords.kw_extends,
4293                      Keywords.kw_implements))
4294       return false;
4295     if (Right.isOneOf(Keywords.kw_throws, Keywords.kw_extends,
4296                       Keywords.kw_implements))
4297       return true;
4298   } else if (Style.isJavaScript()) {
4299     const FormatToken *NonComment = Right.getPreviousNonComment();
4300     if (NonComment &&
4301         NonComment->isOneOf(
4302             tok::kw_return, Keywords.kw_yield, tok::kw_continue, tok::kw_break,
4303             tok::kw_throw, Keywords.kw_interface, Keywords.kw_type,
4304             tok::kw_static, tok::kw_public, tok::kw_private, tok::kw_protected,
4305             Keywords.kw_readonly, Keywords.kw_override, Keywords.kw_abstract,
4306             Keywords.kw_get, Keywords.kw_set, Keywords.kw_async,
4307             Keywords.kw_await))
4308       return false; // Otherwise automatic semicolon insertion would trigger.
4309     if (Right.NestingLevel == 0 &&
4310         (Left.Tok.getIdentifierInfo() ||
4311          Left.isOneOf(tok::r_square, tok::r_paren)) &&
4312         Right.isOneOf(tok::l_square, tok::l_paren))
4313       return false; // Otherwise automatic semicolon insertion would trigger.
4314     if (NonComment && NonComment->is(tok::identifier) &&
4315         NonComment->TokenText == "asserts")
4316       return false;
4317     if (Left.is(TT_FatArrow) && Right.is(tok::l_brace))
4318       return false;
4319     if (Left.is(TT_JsTypeColon))
4320       return true;
4321     // Don't wrap between ":" and "!" of a strict prop init ("field!: type;").
4322     if (Left.is(tok::exclaim) && Right.is(tok::colon))
4323       return false;
4324     // Look for is type annotations like:
4325     // function f(): a is B { ... }
4326     // Do not break before is in these cases.
4327     if (Right.is(Keywords.kw_is)) {
4328       const FormatToken *Next = Right.getNextNonComment();
4329       // If `is` is followed by a colon, it's likely that it's a dict key, so
4330       // ignore it for this check.
4331       // For example this is common in Polymer:
4332       // Polymer({
4333       //   is: 'name',
4334       //   ...
4335       // });
4336       if (!Next || !Next->is(tok::colon))
4337         return false;
4338     }
4339     if (Left.is(Keywords.kw_in))
4340       return Style.BreakBeforeBinaryOperators == FormatStyle::BOS_None;
4341     if (Right.is(Keywords.kw_in))
4342       return Style.BreakBeforeBinaryOperators != FormatStyle::BOS_None;
4343     if (Right.is(Keywords.kw_as))
4344       return false; // must not break before as in 'x as type' casts
4345     if (Right.isOneOf(Keywords.kw_extends, Keywords.kw_infer)) {
4346       // extends and infer can appear as keywords in conditional types:
4347       //   https://www.typescriptlang.org/docs/handbook/release-notes/typescript-2-8.html#conditional-types
4348       // do not break before them, as the expressions are subject to ASI.
4349       return false;
4350     }
4351     if (Left.is(Keywords.kw_as))
4352       return true;
4353     if (Left.is(TT_NonNullAssertion))
4354       return true;
4355     if (Left.is(Keywords.kw_declare) &&
4356         Right.isOneOf(Keywords.kw_module, tok::kw_namespace,
4357                       Keywords.kw_function, tok::kw_class, tok::kw_enum,
4358                       Keywords.kw_interface, Keywords.kw_type, Keywords.kw_var,
4359                       Keywords.kw_let, tok::kw_const))
4360       // See grammar for 'declare' statements at:
4361       // https://github.com/Microsoft/TypeScript/blob/main/doc/spec-ARCHIVED.md#A.10
4362       return false;
4363     if (Left.isOneOf(Keywords.kw_module, tok::kw_namespace) &&
4364         Right.isOneOf(tok::identifier, tok::string_literal))
4365       return false; // must not break in "module foo { ...}"
4366     if (Right.is(TT_TemplateString) && Right.closesScope())
4367       return false;
4368     // Don't split tagged template literal so there is a break between the tag
4369     // identifier and template string.
4370     if (Left.is(tok::identifier) && Right.is(TT_TemplateString))
4371       return false;
4372     if (Left.is(TT_TemplateString) && Left.opensScope())
4373       return true;
4374   }
4375 
4376   if (Left.is(tok::at))
4377     return false;
4378   if (Left.Tok.getObjCKeywordID() == tok::objc_interface)
4379     return false;
4380   if (Left.isOneOf(TT_JavaAnnotation, TT_LeadingJavaAnnotation))
4381     return !Right.is(tok::l_paren);
4382   if (Right.is(TT_PointerOrReference))
4383     return Line.IsMultiVariableDeclStmt ||
4384            (getTokenPointerOrReferenceAlignment(Right) ==
4385                 FormatStyle::PAS_Right &&
4386             (!Right.Next || Right.Next->isNot(TT_FunctionDeclarationName)));
4387   if (Right.isOneOf(TT_StartOfName, TT_FunctionDeclarationName) ||
4388       Right.is(tok::kw_operator))
4389     return true;
4390   if (Left.is(TT_PointerOrReference))
4391     return false;
4392   if (Right.isTrailingComment())
4393     // We rely on MustBreakBefore being set correctly here as we should not
4394     // change the "binding" behavior of a comment.
4395     // The first comment in a braced lists is always interpreted as belonging to
4396     // the first list element. Otherwise, it should be placed outside of the
4397     // list.
4398     return Left.is(BK_BracedInit) ||
4399            (Left.is(TT_CtorInitializerColon) &&
4400             Style.BreakConstructorInitializers == FormatStyle::BCIS_AfterColon);
4401   if (Left.is(tok::question) && Right.is(tok::colon))
4402     return false;
4403   if (Right.is(TT_ConditionalExpr) || Right.is(tok::question))
4404     return Style.BreakBeforeTernaryOperators;
4405   if (Left.is(TT_ConditionalExpr) || Left.is(tok::question))
4406     return !Style.BreakBeforeTernaryOperators;
4407   if (Left.is(TT_InheritanceColon))
4408     return Style.BreakInheritanceList == FormatStyle::BILS_AfterColon;
4409   if (Right.is(TT_InheritanceColon))
4410     return Style.BreakInheritanceList != FormatStyle::BILS_AfterColon;
4411   if (Right.is(TT_ObjCMethodExpr) && !Right.is(tok::r_square) &&
4412       Left.isNot(TT_SelectorName))
4413     return true;
4414 
4415   if (Right.is(tok::colon) &&
4416       !Right.isOneOf(TT_CtorInitializerColon, TT_InlineASMColon))
4417     return false;
4418   if (Left.is(tok::colon) && Left.isOneOf(TT_DictLiteral, TT_ObjCMethodExpr)) {
4419     if (Style.Language == FormatStyle::LK_Proto ||
4420         Style.Language == FormatStyle::LK_TextProto) {
4421       if (!Style.AlwaysBreakBeforeMultilineStrings && Right.isStringLiteral())
4422         return false;
4423       // Prevent cases like:
4424       //
4425       // submessage:
4426       //     { key: valueeeeeeeeeeee }
4427       //
4428       // when the snippet does not fit into one line.
4429       // Prefer:
4430       //
4431       // submessage: {
4432       //   key: valueeeeeeeeeeee
4433       // }
4434       //
4435       // instead, even if it is longer by one line.
4436       //
4437       // Note that this allows allows the "{" to go over the column limit
4438       // when the column limit is just between ":" and "{", but that does
4439       // not happen too often and alternative formattings in this case are
4440       // not much better.
4441       //
4442       // The code covers the cases:
4443       //
4444       // submessage: { ... }
4445       // submessage: < ... >
4446       // repeated: [ ... ]
4447       if (((Right.is(tok::l_brace) || Right.is(tok::less)) &&
4448            Right.is(TT_DictLiteral)) ||
4449           Right.is(TT_ArrayInitializerLSquare))
4450         return false;
4451     }
4452     return true;
4453   }
4454   if (Right.is(tok::r_square) && Right.MatchingParen &&
4455       Right.MatchingParen->is(TT_ProtoExtensionLSquare))
4456     return false;
4457   if (Right.is(TT_SelectorName) || (Right.is(tok::identifier) && Right.Next &&
4458                                     Right.Next->is(TT_ObjCMethodExpr)))
4459     return Left.isNot(tok::period); // FIXME: Properly parse ObjC calls.
4460   if (Left.is(tok::r_paren) && Line.Type == LT_ObjCProperty)
4461     return true;
4462   if (Right.is(tok::kw_concept))
4463     return Style.BreakBeforeConceptDeclarations != FormatStyle::BBCDS_Never;
4464   if (Right.is(TT_RequiresClause))
4465     return true;
4466   if (Left.ClosesTemplateDeclaration || Left.is(TT_FunctionAnnotationRParen))
4467     return true;
4468   if (Left.ClosesRequiresClause)
4469     return true;
4470   if (Right.isOneOf(TT_RangeBasedForLoopColon, TT_OverloadedOperatorLParen,
4471                     TT_OverloadedOperator))
4472     return false;
4473   if (Left.is(TT_RangeBasedForLoopColon))
4474     return true;
4475   if (Right.is(TT_RangeBasedForLoopColon))
4476     return false;
4477   if (Left.is(TT_TemplateCloser) && Right.is(TT_TemplateOpener))
4478     return true;
4479   if ((Left.is(tok::greater) && Right.is(tok::greater)) ||
4480       (Left.is(tok::less) && Right.is(tok::less)))
4481     return false;
4482   if (Right.is(TT_BinaryOperator) &&
4483       Style.BreakBeforeBinaryOperators != FormatStyle::BOS_None &&
4484       (Style.BreakBeforeBinaryOperators == FormatStyle::BOS_All ||
4485        Right.getPrecedence() != prec::Assignment))
4486     return true;
4487   if (Left.isOneOf(TT_TemplateCloser, TT_UnaryOperator) ||
4488       Left.is(tok::kw_operator))
4489     return false;
4490   if (Left.is(tok::equal) && !Right.isOneOf(tok::kw_default, tok::kw_delete) &&
4491       Line.Type == LT_VirtualFunctionDecl && Left.NestingLevel == 0)
4492     return false;
4493   if (Left.is(tok::equal) && Right.is(tok::l_brace) &&
4494       !Style.Cpp11BracedListStyle)
4495     return false;
4496   if (Left.is(tok::l_paren) &&
4497       Left.isOneOf(TT_AttributeParen, TT_TypeDeclarationParen))
4498     return false;
4499   if (Left.is(tok::l_paren) && Left.Previous &&
4500       (Left.Previous->isOneOf(TT_BinaryOperator, TT_CastRParen)))
4501     return false;
4502   if (Right.is(TT_ImplicitStringLiteral))
4503     return false;
4504 
4505   if (Right.is(TT_TemplateCloser))
4506     return false;
4507   if (Right.is(tok::r_square) && Right.MatchingParen &&
4508       Right.MatchingParen->is(TT_LambdaLSquare))
4509     return false;
4510 
4511   // We only break before r_brace if there was a corresponding break before
4512   // the l_brace, which is tracked by BreakBeforeClosingBrace.
4513   if (Right.is(tok::r_brace))
4514     return Right.MatchingParen && Right.MatchingParen->is(BK_Block);
4515 
4516   // We only break before r_paren if we're in a block indented context.
4517   if (Right.is(tok::r_paren)) {
4518     if (Style.AlignAfterOpenBracket == FormatStyle::BAS_BlockIndent)
4519       return Right.MatchingParen &&
4520              !(Right.MatchingParen->Previous &&
4521                (Right.MatchingParen->Previous->is(tok::kw_for) ||
4522                 Right.MatchingParen->Previous->isIf()));
4523 
4524     return false;
4525   }
4526 
4527   // Allow breaking after a trailing annotation, e.g. after a method
4528   // declaration.
4529   if (Left.is(TT_TrailingAnnotation))
4530     return !Right.isOneOf(tok::l_brace, tok::semi, tok::equal, tok::l_paren,
4531                           tok::less, tok::coloncolon);
4532 
4533   if (Right.is(tok::kw___attribute) ||
4534       (Right.is(tok::l_square) && Right.is(TT_AttributeSquare)))
4535     return !Left.is(TT_AttributeSquare);
4536 
4537   if (Left.is(tok::identifier) && Right.is(tok::string_literal))
4538     return true;
4539 
4540   if (Right.is(tok::identifier) && Right.Next && Right.Next->is(TT_DictLiteral))
4541     return true;
4542 
4543   if (Left.is(TT_CtorInitializerColon))
4544     return Style.BreakConstructorInitializers == FormatStyle::BCIS_AfterColon;
4545   if (Right.is(TT_CtorInitializerColon))
4546     return Style.BreakConstructorInitializers != FormatStyle::BCIS_AfterColon;
4547   if (Left.is(TT_CtorInitializerComma) &&
4548       Style.BreakConstructorInitializers == FormatStyle::BCIS_BeforeComma)
4549     return false;
4550   if (Right.is(TT_CtorInitializerComma) &&
4551       Style.BreakConstructorInitializers == FormatStyle::BCIS_BeforeComma)
4552     return true;
4553   if (Left.is(TT_InheritanceComma) &&
4554       Style.BreakInheritanceList == FormatStyle::BILS_BeforeComma)
4555     return false;
4556   if (Right.is(TT_InheritanceComma) &&
4557       Style.BreakInheritanceList == FormatStyle::BILS_BeforeComma)
4558     return true;
4559   if (Left.is(TT_ArrayInitializerLSquare))
4560     return true;
4561   if (Right.is(tok::kw_typename) && Left.isNot(tok::kw_const))
4562     return true;
4563   if ((Left.isBinaryOperator() || Left.is(TT_BinaryOperator)) &&
4564       !Left.isOneOf(tok::arrowstar, tok::lessless) &&
4565       Style.BreakBeforeBinaryOperators != FormatStyle::BOS_All &&
4566       (Style.BreakBeforeBinaryOperators == FormatStyle::BOS_None ||
4567        Left.getPrecedence() == prec::Assignment))
4568     return true;
4569   if ((Left.is(TT_AttributeSquare) && Right.is(tok::l_square)) ||
4570       (Left.is(tok::r_square) && Right.is(TT_AttributeSquare)))
4571     return false;
4572 
4573   auto ShortLambdaOption = Style.AllowShortLambdasOnASingleLine;
4574   if (Style.BraceWrapping.BeforeLambdaBody && Right.is(TT_LambdaLBrace)) {
4575     if (isAllmanLambdaBrace(Left))
4576       return !isItAnEmptyLambdaAllowed(Left, ShortLambdaOption);
4577     if (isAllmanLambdaBrace(Right))
4578       return !isItAnEmptyLambdaAllowed(Right, ShortLambdaOption);
4579   }
4580 
4581   return Left.isOneOf(tok::comma, tok::coloncolon, tok::semi, tok::l_brace,
4582                       tok::kw_class, tok::kw_struct, tok::comment) ||
4583          Right.isMemberAccess() ||
4584          Right.isOneOf(TT_TrailingReturnArrow, TT_LambdaArrow, tok::lessless,
4585                        tok::colon, tok::l_square, tok::at) ||
4586          (Left.is(tok::r_paren) &&
4587           Right.isOneOf(tok::identifier, tok::kw_const)) ||
4588          (Left.is(tok::l_paren) && !Right.is(tok::r_paren)) ||
4589          (Left.is(TT_TemplateOpener) && !Right.is(TT_TemplateCloser));
4590 }
4591 
4592 void TokenAnnotator::printDebugInfo(const AnnotatedLine &Line) {
4593   llvm::errs() << "AnnotatedTokens(L=" << Line.Level << "):\n";
4594   const FormatToken *Tok = Line.First;
4595   while (Tok) {
4596     llvm::errs() << " M=" << Tok->MustBreakBefore
4597                  << " C=" << Tok->CanBreakBefore
4598                  << " T=" << getTokenTypeName(Tok->getType())
4599                  << " S=" << Tok->SpacesRequiredBefore
4600                  << " F=" << Tok->Finalized << " B=" << Tok->BlockParameterCount
4601                  << " BK=" << Tok->getBlockKind() << " P=" << Tok->SplitPenalty
4602                  << " Name=" << Tok->Tok.getName() << " L=" << Tok->TotalLength
4603                  << " PPK=" << Tok->getPackingKind() << " FakeLParens=";
4604     for (prec::Level LParen : Tok->FakeLParens)
4605       llvm::errs() << LParen << "/";
4606     llvm::errs() << " FakeRParens=" << Tok->FakeRParens;
4607     llvm::errs() << " II=" << Tok->Tok.getIdentifierInfo();
4608     llvm::errs() << " Text='" << Tok->TokenText << "'\n";
4609     if (!Tok->Next)
4610       assert(Tok == Line.Last);
4611     Tok = Tok->Next;
4612   }
4613   llvm::errs() << "----\n";
4614 }
4615 
4616 FormatStyle::PointerAlignmentStyle
4617 TokenAnnotator::getTokenReferenceAlignment(const FormatToken &Reference) {
4618   assert(Reference.isOneOf(tok::amp, tok::ampamp));
4619   switch (Style.ReferenceAlignment) {
4620   case FormatStyle::RAS_Pointer:
4621     return Style.PointerAlignment;
4622   case FormatStyle::RAS_Left:
4623     return FormatStyle::PAS_Left;
4624   case FormatStyle::RAS_Right:
4625     return FormatStyle::PAS_Right;
4626   case FormatStyle::RAS_Middle:
4627     return FormatStyle::PAS_Middle;
4628   }
4629   assert(0); //"Unhandled value of ReferenceAlignment"
4630   return Style.PointerAlignment;
4631 }
4632 
4633 FormatStyle::PointerAlignmentStyle
4634 TokenAnnotator::getTokenPointerOrReferenceAlignment(
4635     const FormatToken &PointerOrReference) {
4636   if (PointerOrReference.isOneOf(tok::amp, tok::ampamp)) {
4637     switch (Style.ReferenceAlignment) {
4638     case FormatStyle::RAS_Pointer:
4639       return Style.PointerAlignment;
4640     case FormatStyle::RAS_Left:
4641       return FormatStyle::PAS_Left;
4642     case FormatStyle::RAS_Right:
4643       return FormatStyle::PAS_Right;
4644     case FormatStyle::RAS_Middle:
4645       return FormatStyle::PAS_Middle;
4646     }
4647   }
4648   assert(PointerOrReference.is(tok::star));
4649   return Style.PointerAlignment;
4650 }
4651 
4652 } // namespace format
4653 } // namespace clang
4654