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 token can be used as an identifier in
30 /// an Objective-C \c \@selector, \c false otherwise.
31 ///
32 /// Because getFormattingLangOpts() always lexes source code as
33 /// Objective-C++, C++ keywords like \c new and \c delete are
34 /// lexed as tok::kw_*, not tok::identifier, even for Objective-C.
35 ///
36 /// For Objective-C and Objective-C++, both identifiers and keywords
37 /// are valid inside @selector(...) (or a macro which
38 /// invokes @selector(...)). So, we allow treat any identifier or
39 /// keyword as a potential Objective-C selector component.
40 static bool canBeObjCSelectorComponent(const FormatToken &Tok) {
41   return Tok.Tok.getIdentifierInfo() != nullptr;
42 }
43 
44 /// With `Left` being '(', check if we're at either `[...](` or
45 /// `[...]<...>(`, where the [ opens a lambda capture list.
46 static bool isLambdaParameterList(const FormatToken *Left) {
47   // Skip <...> if present.
48   if (Left->Previous && Left->Previous->is(tok::greater) &&
49       Left->Previous->MatchingParen &&
50       Left->Previous->MatchingParen->is(TT_TemplateOpener))
51     Left = Left->Previous->MatchingParen;
52 
53   // Check for `[...]`.
54   return Left->Previous && Left->Previous->is(tok::r_square) &&
55          Left->Previous->MatchingParen &&
56          Left->Previous->MatchingParen->is(TT_LambdaLSquare);
57 }
58 
59 /// Returns \c true if the token is followed by a boolean condition, \c false
60 /// otherwise.
61 static bool isKeywordWithCondition(const FormatToken &Tok) {
62   return Tok.isOneOf(tok::kw_if, tok::kw_for, tok::kw_while, tok::kw_switch,
63                      tok::kw_constexpr, tok::kw_catch);
64 }
65 
66 /// A parser that gathers additional information about tokens.
67 ///
68 /// The \c TokenAnnotator tries to match parenthesis and square brakets and
69 /// store a parenthesis levels. It also tries to resolve matching "<" and ">"
70 /// into template parameter lists.
71 class AnnotatingParser {
72 public:
73   AnnotatingParser(const FormatStyle &Style, AnnotatedLine &Line,
74                    const AdditionalKeywords &Keywords)
75       : Style(Style), Line(Line), CurrentToken(Line.First), AutoFound(false),
76         Keywords(Keywords) {
77     Contexts.push_back(Context(tok::unknown, 1, /*IsExpression=*/false));
78     resetTokenMetadata(CurrentToken);
79   }
80 
81 private:
82   bool parseAngle() {
83     if (!CurrentToken || !CurrentToken->Previous)
84       return false;
85     if (NonTemplateLess.count(CurrentToken->Previous))
86       return false;
87 
88     const FormatToken &Previous = *CurrentToken->Previous; // The '<'.
89     if (Previous.Previous) {
90       if (Previous.Previous->Tok.isLiteral())
91         return false;
92       if (Previous.Previous->is(tok::r_paren) && Contexts.size() > 1 &&
93           (!Previous.Previous->MatchingParen ||
94            !Previous.Previous->MatchingParen->is(TT_OverloadedOperatorLParen)))
95         return false;
96     }
97 
98     FormatToken *Left = CurrentToken->Previous;
99     Left->ParentBracket = Contexts.back().ContextKind;
100     ScopedContextCreator ContextCreator(*this, tok::less, 12);
101 
102     // If this angle is in the context of an expression, we need to be more
103     // hesitant to detect it as opening template parameters.
104     bool InExprContext = Contexts.back().IsExpression;
105 
106     Contexts.back().IsExpression = false;
107     // If there's a template keyword before the opening angle bracket, this is a
108     // template parameter, not an argument.
109     Contexts.back().InTemplateArgument =
110         Left->Previous && Left->Previous->Tok.isNot(tok::kw_template);
111 
112     if (Style.Language == FormatStyle::LK_Java &&
113         CurrentToken->is(tok::question))
114       next();
115 
116     while (CurrentToken) {
117       if (CurrentToken->is(tok::greater)) {
118         // Try to do a better job at looking for ">>" within the condition of
119         // a statement. Conservatively insert spaces between consecutive ">"
120         // tokens to prevent splitting right bitshift operators and potentially
121         // altering program semantics. This check is overly conservative and
122         // will prevent spaces from being inserted in select nested template
123         // parameter cases, but should not alter program semantics.
124         if (CurrentToken->Next && CurrentToken->Next->is(tok::greater) &&
125             Left->ParentBracket != tok::less &&
126             (isKeywordWithCondition(*Line.First) ||
127              CurrentToken->getStartOfNonWhitespace() ==
128                  CurrentToken->Next->getStartOfNonWhitespace().getLocWithOffset(
129                      -1)))
130           return false;
131         Left->MatchingParen = CurrentToken;
132         CurrentToken->MatchingParen = Left;
133         // In TT_Proto, we must distignuish between:
134         //   map<key, value>
135         //   msg < item: data >
136         //   msg: < item: data >
137         // In TT_TextProto, map<key, value> does not occur.
138         if (Style.Language == FormatStyle::LK_TextProto ||
139             (Style.Language == FormatStyle::LK_Proto && Left->Previous &&
140              Left->Previous->isOneOf(TT_SelectorName, TT_DictLiteral)))
141           CurrentToken->setType(TT_DictLiteral);
142         else
143           CurrentToken->setType(TT_TemplateCloser);
144         next();
145         return true;
146       }
147       if (CurrentToken->is(tok::question) &&
148           Style.Language == FormatStyle::LK_Java) {
149         next();
150         continue;
151       }
152       if (CurrentToken->isOneOf(tok::r_paren, tok::r_square, tok::r_brace) ||
153           (CurrentToken->isOneOf(tok::colon, tok::question) && InExprContext &&
154            !Style.isCSharp() && Style.Language != FormatStyle::LK_Proto &&
155            Style.Language != FormatStyle::LK_TextProto))
156         return false;
157       // If a && or || is found and interpreted as a binary operator, this set
158       // of angles is likely part of something like "a < b && c > d". If the
159       // angles are inside an expression, the ||/&& might also be a binary
160       // operator that was misinterpreted because we are parsing template
161       // parameters.
162       // FIXME: This is getting out of hand, write a decent parser.
163       if (CurrentToken->Previous->isOneOf(tok::pipepipe, tok::ampamp) &&
164           CurrentToken->Previous->is(TT_BinaryOperator) &&
165           Contexts[Contexts.size() - 2].IsExpression &&
166           !Line.startsWith(tok::kw_template))
167         return false;
168       updateParameterCount(Left, CurrentToken);
169       if (Style.Language == FormatStyle::LK_Proto) {
170         if (FormatToken *Previous = CurrentToken->getPreviousNonComment()) {
171           if (CurrentToken->is(tok::colon) ||
172               (CurrentToken->isOneOf(tok::l_brace, tok::less) &&
173                Previous->isNot(tok::colon)))
174             Previous->setType(TT_SelectorName);
175         }
176       }
177       if (!consumeToken())
178         return false;
179     }
180     return false;
181   }
182 
183   bool parseUntouchableParens() {
184     while (CurrentToken) {
185       CurrentToken->Finalized = true;
186       switch (CurrentToken->Tok.getKind()) {
187       case tok::l_paren:
188         next();
189         if (!parseUntouchableParens())
190           return false;
191         continue;
192       case tok::r_paren:
193         next();
194         return true;
195       default:
196         // no-op
197         break;
198       }
199       next();
200     }
201     return false;
202   }
203 
204   bool parseParens(bool LookForDecls = false) {
205     if (!CurrentToken)
206       return false;
207     FormatToken *Left = CurrentToken->Previous;
208     assert(Left && "Unknown previous token");
209     FormatToken *PrevNonComment = Left->getPreviousNonComment();
210     Left->ParentBracket = Contexts.back().ContextKind;
211     ScopedContextCreator ContextCreator(*this, tok::l_paren, 1);
212 
213     // FIXME: This is a bit of a hack. Do better.
214     Contexts.back().ColonIsForRangeExpr =
215         Contexts.size() == 2 && Contexts[0].ColonIsForRangeExpr;
216 
217     if (Left->Previous && Left->Previous->is(TT_UntouchableMacroFunc)) {
218       Left->Finalized = true;
219       return parseUntouchableParens();
220     }
221 
222     bool StartsObjCMethodExpr = false;
223     if (FormatToken *MaybeSel = Left->Previous) {
224       // @selector( starts a selector.
225       if (MaybeSel->isObjCAtKeyword(tok::objc_selector) && MaybeSel->Previous &&
226           MaybeSel->Previous->is(tok::at)) {
227         StartsObjCMethodExpr = true;
228       }
229     }
230 
231     if (Left->is(TT_OverloadedOperatorLParen)) {
232       // Find the previous kw_operator token.
233       FormatToken *Prev = Left;
234       while (!Prev->is(tok::kw_operator)) {
235         Prev = Prev->Previous;
236         assert(Prev && "Expect a kw_operator prior to the OperatorLParen!");
237       }
238 
239       // If faced with "a.operator*(argument)" or "a->operator*(argument)",
240       // i.e. the operator is called as a member function,
241       // then the argument must be an expression.
242       bool OperatorCalledAsMemberFunction =
243           Prev->Previous && Prev->Previous->isOneOf(tok::period, tok::arrow);
244       Contexts.back().IsExpression = OperatorCalledAsMemberFunction;
245     } else if (Style.Language == FormatStyle::LK_JavaScript &&
246                (Line.startsWith(Keywords.kw_type, tok::identifier) ||
247                 Line.startsWith(tok::kw_export, Keywords.kw_type,
248                                 tok::identifier))) {
249       // type X = (...);
250       // export type X = (...);
251       Contexts.back().IsExpression = false;
252     } else if (Left->Previous &&
253                (Left->Previous->isOneOf(tok::kw_static_assert, tok::kw_while,
254                                         tok::l_paren, tok::comma) ||
255                 Left->Previous->isIf() ||
256                 Left->Previous->is(TT_BinaryOperator))) {
257       // static_assert, if and while usually contain expressions.
258       Contexts.back().IsExpression = true;
259     } else if (Style.Language == FormatStyle::LK_JavaScript && Left->Previous &&
260                (Left->Previous->is(Keywords.kw_function) ||
261                 (Left->Previous->endsSequence(tok::identifier,
262                                               Keywords.kw_function)))) {
263       // function(...) or function f(...)
264       Contexts.back().IsExpression = false;
265     } else if (Style.Language == FormatStyle::LK_JavaScript && Left->Previous &&
266                Left->Previous->is(TT_JsTypeColon)) {
267       // let x: (SomeType);
268       Contexts.back().IsExpression = false;
269     } else if (isLambdaParameterList(Left)) {
270       // This is a parameter list of a lambda expression.
271       Contexts.back().IsExpression = false;
272     } else if (Line.InPPDirective &&
273                (!Left->Previous || !Left->Previous->is(tok::identifier))) {
274       Contexts.back().IsExpression = true;
275     } else if (Contexts[Contexts.size() - 2].CaretFound) {
276       // This is the parameter list of an ObjC block.
277       Contexts.back().IsExpression = false;
278     } else if (Left->Previous && Left->Previous->is(TT_ForEachMacro)) {
279       // The first argument to a foreach macro is a declaration.
280       Contexts.back().IsForEachMacro = true;
281       Contexts.back().IsExpression = false;
282     } else if (Left->Previous && Left->Previous->MatchingParen &&
283                Left->Previous->MatchingParen->is(TT_ObjCBlockLParen)) {
284       Contexts.back().IsExpression = false;
285     } else if (!Line.MustBeDeclaration && !Line.InPPDirective) {
286       bool IsForOrCatch =
287           Left->Previous && Left->Previous->isOneOf(tok::kw_for, tok::kw_catch);
288       Contexts.back().IsExpression = !IsForOrCatch;
289     }
290 
291     // Infer the role of the l_paren based on the previous token if we haven't
292     // detected one one yet.
293     if (PrevNonComment && Left->is(TT_Unknown)) {
294       if (PrevNonComment->is(tok::kw___attribute)) {
295         Left->setType(TT_AttributeParen);
296       } else if (PrevNonComment->isOneOf(TT_TypenameMacro, tok::kw_decltype,
297                                          tok::kw_typeof, tok::kw__Atomic,
298                                          tok::kw___underlying_type)) {
299         Left->setType(TT_TypeDeclarationParen);
300         // decltype() and typeof() usually contain expressions.
301         if (PrevNonComment->isOneOf(tok::kw_decltype, tok::kw_typeof))
302           Contexts.back().IsExpression = true;
303       }
304     }
305 
306     if (StartsObjCMethodExpr) {
307       Contexts.back().ColonIsObjCMethodExpr = true;
308       Left->setType(TT_ObjCMethodExpr);
309     }
310 
311     // MightBeFunctionType and ProbablyFunctionType are used for
312     // function pointer and reference types as well as Objective-C
313     // block types:
314     //
315     // void (*FunctionPointer)(void);
316     // void (&FunctionReference)(void);
317     // void (^ObjCBlock)(void);
318     bool MightBeFunctionType = !Contexts[Contexts.size() - 2].IsExpression;
319     bool ProbablyFunctionType =
320         CurrentToken->isOneOf(tok::star, tok::amp, tok::caret);
321     bool HasMultipleLines = false;
322     bool HasMultipleParametersOnALine = false;
323     bool MightBeObjCForRangeLoop =
324         Left->Previous && Left->Previous->is(tok::kw_for);
325     FormatToken *PossibleObjCForInToken = nullptr;
326     while (CurrentToken) {
327       // LookForDecls is set when "if (" has been seen. Check for
328       // 'identifier' '*' 'identifier' followed by not '=' -- this
329       // '*' has to be a binary operator but determineStarAmpUsage() will
330       // categorize it as an unary operator, so set the right type here.
331       if (LookForDecls && CurrentToken->Next) {
332         FormatToken *Prev = CurrentToken->getPreviousNonComment();
333         if (Prev) {
334           FormatToken *PrevPrev = Prev->getPreviousNonComment();
335           FormatToken *Next = CurrentToken->Next;
336           if (PrevPrev && PrevPrev->is(tok::identifier) &&
337               Prev->isOneOf(tok::star, tok::amp, tok::ampamp) &&
338               CurrentToken->is(tok::identifier) && Next->isNot(tok::equal)) {
339             Prev->setType(TT_BinaryOperator);
340             LookForDecls = false;
341           }
342         }
343       }
344 
345       if (CurrentToken->Previous->is(TT_PointerOrReference) &&
346           CurrentToken->Previous->Previous->isOneOf(tok::l_paren,
347                                                     tok::coloncolon))
348         ProbablyFunctionType = true;
349       if (CurrentToken->is(tok::comma))
350         MightBeFunctionType = false;
351       if (CurrentToken->Previous->is(TT_BinaryOperator))
352         Contexts.back().IsExpression = true;
353       if (CurrentToken->is(tok::r_paren)) {
354         if (MightBeFunctionType && ProbablyFunctionType && CurrentToken->Next &&
355             (CurrentToken->Next->is(tok::l_paren) ||
356              (CurrentToken->Next->is(tok::l_square) && Line.MustBeDeclaration)))
357           Left->setType(Left->Next->is(tok::caret) ? TT_ObjCBlockLParen
358                                                    : TT_FunctionTypeLParen);
359         Left->MatchingParen = CurrentToken;
360         CurrentToken->MatchingParen = Left;
361 
362         if (CurrentToken->Next && CurrentToken->Next->is(tok::l_brace) &&
363             Left->Previous && Left->Previous->is(tok::l_paren)) {
364           // Detect the case where macros are used to generate lambdas or
365           // function bodies, e.g.:
366           //   auto my_lambda = MARCO((Type *type, int i) { .. body .. });
367           for (FormatToken *Tok = Left; Tok != CurrentToken; Tok = Tok->Next) {
368             if (Tok->is(TT_BinaryOperator) &&
369                 Tok->isOneOf(tok::star, tok::amp, tok::ampamp))
370               Tok->setType(TT_PointerOrReference);
371           }
372         }
373 
374         if (StartsObjCMethodExpr) {
375           CurrentToken->setType(TT_ObjCMethodExpr);
376           if (Contexts.back().FirstObjCSelectorName) {
377             Contexts.back().FirstObjCSelectorName->LongestObjCSelectorName =
378                 Contexts.back().LongestObjCSelectorName;
379           }
380         }
381 
382         if (Left->is(TT_AttributeParen))
383           CurrentToken->setType(TT_AttributeParen);
384         if (Left->is(TT_TypeDeclarationParen))
385           CurrentToken->setType(TT_TypeDeclarationParen);
386         if (Left->Previous && Left->Previous->is(TT_JavaAnnotation))
387           CurrentToken->setType(TT_JavaAnnotation);
388         if (Left->Previous && Left->Previous->is(TT_LeadingJavaAnnotation))
389           CurrentToken->setType(TT_LeadingJavaAnnotation);
390         if (Left->Previous && Left->Previous->is(TT_AttributeSquare))
391           CurrentToken->setType(TT_AttributeSquare);
392 
393         if (!HasMultipleLines)
394           Left->setPackingKind(PPK_Inconclusive);
395         else if (HasMultipleParametersOnALine)
396           Left->setPackingKind(PPK_BinPacked);
397         else
398           Left->setPackingKind(PPK_OnePerLine);
399 
400         next();
401         return true;
402       }
403       if (CurrentToken->isOneOf(tok::r_square, tok::r_brace))
404         return false;
405 
406       if (CurrentToken->is(tok::l_brace))
407         Left->setType(TT_Unknown); // Not TT_ObjCBlockLParen
408       if (CurrentToken->is(tok::comma) && CurrentToken->Next &&
409           !CurrentToken->Next->HasUnescapedNewline &&
410           !CurrentToken->Next->isTrailingComment())
411         HasMultipleParametersOnALine = true;
412       bool ProbablyFunctionTypeLParen =
413           (CurrentToken->is(tok::l_paren) && CurrentToken->Next &&
414            CurrentToken->Next->isOneOf(tok::star, tok::amp, tok::caret));
415       if ((CurrentToken->Previous->isOneOf(tok::kw_const, tok::kw_auto) ||
416            CurrentToken->Previous->isSimpleTypeSpecifier()) &&
417           !(CurrentToken->is(tok::l_brace) ||
418             (CurrentToken->is(tok::l_paren) && !ProbablyFunctionTypeLParen)))
419         Contexts.back().IsExpression = false;
420       if (CurrentToken->isOneOf(tok::semi, tok::colon)) {
421         MightBeObjCForRangeLoop = false;
422         if (PossibleObjCForInToken) {
423           PossibleObjCForInToken->setType(TT_Unknown);
424           PossibleObjCForInToken = nullptr;
425         }
426       }
427       if (MightBeObjCForRangeLoop && CurrentToken->is(Keywords.kw_in)) {
428         PossibleObjCForInToken = CurrentToken;
429         PossibleObjCForInToken->setType(TT_ObjCForIn);
430       }
431       // When we discover a 'new', we set CanBeExpression to 'false' in order to
432       // parse the type correctly. Reset that after a comma.
433       if (CurrentToken->is(tok::comma))
434         Contexts.back().CanBeExpression = true;
435 
436       FormatToken *Tok = CurrentToken;
437       if (!consumeToken())
438         return false;
439       updateParameterCount(Left, Tok);
440       if (CurrentToken && CurrentToken->HasUnescapedNewline)
441         HasMultipleLines = true;
442     }
443     return false;
444   }
445 
446   bool isCSharpAttributeSpecifier(const FormatToken &Tok) {
447     if (!Style.isCSharp())
448       return false;
449 
450     // `identifier[i]` is not an attribute.
451     if (Tok.Previous && Tok.Previous->is(tok::identifier))
452       return false;
453 
454     // Chains of [] in `identifier[i][j][k]` are not attributes.
455     if (Tok.Previous && Tok.Previous->is(tok::r_square)) {
456       auto *MatchingParen = Tok.Previous->MatchingParen;
457       if (!MatchingParen || MatchingParen->is(TT_ArraySubscriptLSquare))
458         return false;
459     }
460 
461     const FormatToken *AttrTok = Tok.Next;
462     if (!AttrTok)
463       return false;
464 
465     // Just an empty declaration e.g. string [].
466     if (AttrTok->is(tok::r_square))
467       return false;
468 
469     // Move along the tokens inbetween the '[' and ']' e.g. [STAThread].
470     while (AttrTok && AttrTok->isNot(tok::r_square)) {
471       AttrTok = AttrTok->Next;
472     }
473 
474     if (!AttrTok)
475       return false;
476 
477     // Allow an attribute to be the only content of a file.
478     AttrTok = AttrTok->Next;
479     if (!AttrTok)
480       return true;
481 
482     // Limit this to being an access modifier that follows.
483     if (AttrTok->isOneOf(tok::kw_public, tok::kw_private, tok::kw_protected,
484                          tok::comment, tok::kw_class, tok::kw_static,
485                          tok::l_square, Keywords.kw_internal)) {
486       return true;
487     }
488 
489     // incase its a [XXX] retval func(....
490     if (AttrTok->Next &&
491         AttrTok->Next->startsSequence(tok::identifier, tok::l_paren))
492       return true;
493 
494     return false;
495   }
496 
497   bool isCpp11AttributeSpecifier(const FormatToken &Tok) {
498     if (!Style.isCpp() || !Tok.startsSequence(tok::l_square, tok::l_square))
499       return false;
500     // The first square bracket is part of an ObjC array literal
501     if (Tok.Previous && Tok.Previous->is(tok::at)) {
502       return false;
503     }
504     const FormatToken *AttrTok = Tok.Next->Next;
505     if (!AttrTok)
506       return false;
507     // C++17 '[[using ns: foo, bar(baz, blech)]]'
508     // We assume nobody will name an ObjC variable 'using'.
509     if (AttrTok->startsSequence(tok::kw_using, tok::identifier, tok::colon))
510       return true;
511     if (AttrTok->isNot(tok::identifier))
512       return false;
513     while (AttrTok && !AttrTok->startsSequence(tok::r_square, tok::r_square)) {
514       // ObjC message send. We assume nobody will use : in a C++11 attribute
515       // specifier parameter, although this is technically valid:
516       // [[foo(:)]].
517       if (AttrTok->is(tok::colon) ||
518           AttrTok->startsSequence(tok::identifier, tok::identifier) ||
519           AttrTok->startsSequence(tok::r_paren, tok::identifier))
520         return false;
521       if (AttrTok->is(tok::ellipsis))
522         return true;
523       AttrTok = AttrTok->Next;
524     }
525     return AttrTok && AttrTok->startsSequence(tok::r_square, tok::r_square);
526   }
527 
528   bool parseSquare() {
529     if (!CurrentToken)
530       return false;
531 
532     // A '[' could be an index subscript (after an identifier or after
533     // ')' or ']'), it could be the start of an Objective-C method
534     // expression, it could the start of an Objective-C array literal,
535     // or it could be a C++ attribute specifier [[foo::bar]].
536     FormatToken *Left = CurrentToken->Previous;
537     Left->ParentBracket = Contexts.back().ContextKind;
538     FormatToken *Parent = Left->getPreviousNonComment();
539 
540     // Cases where '>' is followed by '['.
541     // In C++, this can happen either in array of templates (foo<int>[10])
542     // or when array is a nested template type (unique_ptr<type1<type2>[]>).
543     bool CppArrayTemplates =
544         Style.isCpp() && Parent && Parent->is(TT_TemplateCloser) &&
545         (Contexts.back().CanBeExpression || Contexts.back().IsExpression ||
546          Contexts.back().InTemplateArgument);
547 
548     bool IsCpp11AttributeSpecifier = isCpp11AttributeSpecifier(*Left) ||
549                                      Contexts.back().InCpp11AttributeSpecifier;
550 
551     // Treat C# Attributes [STAThread] much like C++ attributes [[...]].
552     bool IsCSharpAttributeSpecifier =
553         isCSharpAttributeSpecifier(*Left) ||
554         Contexts.back().InCSharpAttributeSpecifier;
555 
556     bool InsideInlineASM = Line.startsWith(tok::kw_asm);
557     bool IsCppStructuredBinding = Left->isCppStructuredBinding(Style);
558     bool StartsObjCMethodExpr =
559         !IsCppStructuredBinding && !InsideInlineASM && !CppArrayTemplates &&
560         Style.isCpp() && !IsCpp11AttributeSpecifier &&
561         !IsCSharpAttributeSpecifier && Contexts.back().CanBeExpression &&
562         Left->isNot(TT_LambdaLSquare) &&
563         !CurrentToken->isOneOf(tok::l_brace, tok::r_square) &&
564         (!Parent ||
565          Parent->isOneOf(tok::colon, tok::l_square, tok::l_paren,
566                          tok::kw_return, tok::kw_throw) ||
567          Parent->isUnaryOperator() ||
568          // FIXME(bug 36976): ObjC return types shouldn't use TT_CastRParen.
569          Parent->isOneOf(TT_ObjCForIn, TT_CastRParen) ||
570          (getBinOpPrecedence(Parent->Tok.getKind(), true, true) >
571           prec::Unknown));
572     bool ColonFound = false;
573 
574     unsigned BindingIncrease = 1;
575     if (IsCppStructuredBinding) {
576       Left->setType(TT_StructuredBindingLSquare);
577     } else if (Left->is(TT_Unknown)) {
578       if (StartsObjCMethodExpr) {
579         Left->setType(TT_ObjCMethodExpr);
580       } else if (InsideInlineASM) {
581         Left->setType(TT_InlineASMSymbolicNameLSquare);
582       } else if (IsCpp11AttributeSpecifier) {
583         Left->setType(TT_AttributeSquare);
584       } else if (Style.Language == FormatStyle::LK_JavaScript && Parent &&
585                  Contexts.back().ContextKind == tok::l_brace &&
586                  Parent->isOneOf(tok::l_brace, tok::comma)) {
587         Left->setType(TT_JsComputedPropertyName);
588       } else if (Style.isCpp() && Contexts.back().ContextKind == tok::l_brace &&
589                  Parent && Parent->isOneOf(tok::l_brace, tok::comma)) {
590         Left->setType(TT_DesignatedInitializerLSquare);
591       } else if (IsCSharpAttributeSpecifier) {
592         Left->setType(TT_AttributeSquare);
593       } else if (CurrentToken->is(tok::r_square) && Parent &&
594                  Parent->is(TT_TemplateCloser)) {
595         Left->setType(TT_ArraySubscriptLSquare);
596       } else if (Style.Language == FormatStyle::LK_Proto ||
597                  Style.Language == FormatStyle::LK_TextProto) {
598         // Square braces in LK_Proto can either be message field attributes:
599         //
600         // optional Aaa aaa = 1 [
601         //   (aaa) = aaa
602         // ];
603         //
604         // extensions 123 [
605         //   (aaa) = aaa
606         // ];
607         //
608         // or text proto extensions (in options):
609         //
610         // option (Aaa.options) = {
611         //   [type.type/type] {
612         //     key: value
613         //   }
614         // }
615         //
616         // or repeated fields (in options):
617         //
618         // option (Aaa.options) = {
619         //   keys: [ 1, 2, 3 ]
620         // }
621         //
622         // In the first and the third case we want to spread the contents inside
623         // the square braces; in the second we want to keep them inline.
624         Left->setType(TT_ArrayInitializerLSquare);
625         if (!Left->endsSequence(tok::l_square, tok::numeric_constant,
626                                 tok::equal) &&
627             !Left->endsSequence(tok::l_square, tok::numeric_constant,
628                                 tok::identifier) &&
629             !Left->endsSequence(tok::l_square, tok::colon, TT_SelectorName)) {
630           Left->setType(TT_ProtoExtensionLSquare);
631           BindingIncrease = 10;
632         }
633       } else if (!CppArrayTemplates && Parent &&
634                  Parent->isOneOf(TT_BinaryOperator, TT_TemplateCloser, tok::at,
635                                  tok::comma, tok::l_paren, tok::l_square,
636                                  tok::question, tok::colon, tok::kw_return,
637                                  // Should only be relevant to JavaScript:
638                                  tok::kw_default)) {
639         Left->setType(TT_ArrayInitializerLSquare);
640       } else {
641         BindingIncrease = 10;
642         Left->setType(TT_ArraySubscriptLSquare);
643       }
644     }
645 
646     ScopedContextCreator ContextCreator(*this, tok::l_square, BindingIncrease);
647     Contexts.back().IsExpression = true;
648     if (Style.Language == FormatStyle::LK_JavaScript && Parent &&
649         Parent->is(TT_JsTypeColon))
650       Contexts.back().IsExpression = false;
651 
652     Contexts.back().ColonIsObjCMethodExpr = StartsObjCMethodExpr;
653     Contexts.back().InCpp11AttributeSpecifier = IsCpp11AttributeSpecifier;
654     Contexts.back().InCSharpAttributeSpecifier = IsCSharpAttributeSpecifier;
655 
656     while (CurrentToken) {
657       if (CurrentToken->is(tok::r_square)) {
658         if (IsCpp11AttributeSpecifier)
659           CurrentToken->setType(TT_AttributeSquare);
660         if (IsCSharpAttributeSpecifier)
661           CurrentToken->setType(TT_AttributeSquare);
662         else if (((CurrentToken->Next &&
663                    CurrentToken->Next->is(tok::l_paren)) ||
664                   (CurrentToken->Previous &&
665                    CurrentToken->Previous->Previous == Left)) &&
666                  Left->is(TT_ObjCMethodExpr)) {
667           // An ObjC method call is rarely followed by an open parenthesis. It
668           // also can't be composed of just one token, unless it's a macro that
669           // will be expanded to more tokens.
670           // FIXME: Do we incorrectly label ":" with this?
671           StartsObjCMethodExpr = false;
672           Left->setType(TT_Unknown);
673         }
674         if (StartsObjCMethodExpr && CurrentToken->Previous != Left) {
675           CurrentToken->setType(TT_ObjCMethodExpr);
676           // If we haven't seen a colon yet, make sure the last identifier
677           // before the r_square is tagged as a selector name component.
678           if (!ColonFound && CurrentToken->Previous &&
679               CurrentToken->Previous->is(TT_Unknown) &&
680               canBeObjCSelectorComponent(*CurrentToken->Previous))
681             CurrentToken->Previous->setType(TT_SelectorName);
682           // determineStarAmpUsage() thinks that '*' '[' is allocating an
683           // array of pointers, but if '[' starts a selector then '*' is a
684           // binary operator.
685           if (Parent && Parent->is(TT_PointerOrReference))
686             Parent->setType(TT_BinaryOperator);
687         }
688         // An arrow after an ObjC method expression is not a lambda arrow.
689         if (CurrentToken->getType() == TT_ObjCMethodExpr &&
690             CurrentToken->Next && CurrentToken->Next->is(TT_LambdaArrow))
691           CurrentToken->Next->setType(TT_Unknown);
692         Left->MatchingParen = CurrentToken;
693         CurrentToken->MatchingParen = Left;
694         // FirstObjCSelectorName is set when a colon is found. This does
695         // not work, however, when the method has no parameters.
696         // Here, we set FirstObjCSelectorName when the end of the method call is
697         // reached, in case it was not set already.
698         if (!Contexts.back().FirstObjCSelectorName) {
699           FormatToken *Previous = CurrentToken->getPreviousNonComment();
700           if (Previous && Previous->is(TT_SelectorName)) {
701             Previous->ObjCSelectorNameParts = 1;
702             Contexts.back().FirstObjCSelectorName = Previous;
703           }
704         } else {
705           Left->ParameterCount =
706               Contexts.back().FirstObjCSelectorName->ObjCSelectorNameParts;
707         }
708         if (Contexts.back().FirstObjCSelectorName) {
709           Contexts.back().FirstObjCSelectorName->LongestObjCSelectorName =
710               Contexts.back().LongestObjCSelectorName;
711           if (Left->BlockParameterCount > 1)
712             Contexts.back().FirstObjCSelectorName->LongestObjCSelectorName = 0;
713         }
714         next();
715         return true;
716       }
717       if (CurrentToken->isOneOf(tok::r_paren, tok::r_brace))
718         return false;
719       if (CurrentToken->is(tok::colon)) {
720         if (IsCpp11AttributeSpecifier &&
721             CurrentToken->endsSequence(tok::colon, tok::identifier,
722                                        tok::kw_using)) {
723           // Remember that this is a [[using ns: foo]] C++ attribute, so we
724           // don't add a space before the colon (unlike other colons).
725           CurrentToken->setType(TT_AttributeColon);
726         } else if (Left->isOneOf(TT_ArraySubscriptLSquare,
727                                  TT_DesignatedInitializerLSquare)) {
728           Left->setType(TT_ObjCMethodExpr);
729           StartsObjCMethodExpr = true;
730           Contexts.back().ColonIsObjCMethodExpr = true;
731           if (Parent && Parent->is(tok::r_paren))
732             // FIXME(bug 36976): ObjC return types shouldn't use TT_CastRParen.
733             Parent->setType(TT_CastRParen);
734         }
735         ColonFound = true;
736       }
737       if (CurrentToken->is(tok::comma) && Left->is(TT_ObjCMethodExpr) &&
738           !ColonFound)
739         Left->setType(TT_ArrayInitializerLSquare);
740       FormatToken *Tok = CurrentToken;
741       if (!consumeToken())
742         return false;
743       updateParameterCount(Left, Tok);
744     }
745     return false;
746   }
747 
748   bool couldBeInStructArrayInitializer() const {
749     if (Contexts.size() < 2)
750       return false;
751     // We want to back up no more then 2 context levels i.e.
752     // . { { <-
753     const auto End = std::next(Contexts.rbegin(), 2);
754     auto Last = Contexts.rbegin();
755     unsigned Depth = 0;
756     for (; Last != End; ++Last) {
757       if (Last->ContextKind == tok::l_brace)
758         ++Depth;
759     }
760     return Depth == 2 && Last->ContextKind != tok::l_brace;
761   }
762 
763   bool parseBrace() {
764     if (CurrentToken) {
765       FormatToken *Left = CurrentToken->Previous;
766       Left->ParentBracket = Contexts.back().ContextKind;
767 
768       if (Contexts.back().CaretFound)
769         Left->setType(TT_ObjCBlockLBrace);
770       Contexts.back().CaretFound = false;
771 
772       ScopedContextCreator ContextCreator(*this, tok::l_brace, 1);
773       Contexts.back().ColonIsDictLiteral = true;
774       if (Left->is(BK_BracedInit))
775         Contexts.back().IsExpression = true;
776       if (Style.Language == FormatStyle::LK_JavaScript && Left->Previous &&
777           Left->Previous->is(TT_JsTypeColon))
778         Contexts.back().IsExpression = false;
779 
780       unsigned CommaCount = 0;
781       while (CurrentToken) {
782         if (CurrentToken->is(tok::r_brace)) {
783           Left->MatchingParen = CurrentToken;
784           CurrentToken->MatchingParen = Left;
785           if (Style.AlignArrayOfStructures != FormatStyle::AIAS_None) {
786             if (Left->ParentBracket == tok::l_brace &&
787                 couldBeInStructArrayInitializer() && CommaCount > 0) {
788               Contexts.back().InStructArrayInitializer = true;
789             }
790           }
791           next();
792           return true;
793         }
794         if (CurrentToken->isOneOf(tok::r_paren, tok::r_square))
795           return false;
796         updateParameterCount(Left, CurrentToken);
797         if (CurrentToken->isOneOf(tok::colon, tok::l_brace, tok::less)) {
798           FormatToken *Previous = CurrentToken->getPreviousNonComment();
799           if (Previous->is(TT_JsTypeOptionalQuestion))
800             Previous = Previous->getPreviousNonComment();
801           if ((CurrentToken->is(tok::colon) &&
802                (!Contexts.back().ColonIsDictLiteral || !Style.isCpp())) ||
803               Style.Language == FormatStyle::LK_Proto ||
804               Style.Language == FormatStyle::LK_TextProto) {
805             Left->setType(TT_DictLiteral);
806             if (Previous->Tok.getIdentifierInfo() ||
807                 Previous->is(tok::string_literal))
808               Previous->setType(TT_SelectorName);
809           }
810           if (CurrentToken->is(tok::colon) ||
811               Style.Language == FormatStyle::LK_JavaScript)
812             Left->setType(TT_DictLiteral);
813         }
814         if (CurrentToken->is(tok::comma)) {
815           if (Style.Language == FormatStyle::LK_JavaScript)
816             Left->setType(TT_DictLiteral);
817           ++CommaCount;
818         }
819         if (!consumeToken())
820           return false;
821       }
822     }
823     return true;
824   }
825 
826   void updateParameterCount(FormatToken *Left, FormatToken *Current) {
827     // For ObjC methods, the number of parameters is calculated differently as
828     // method declarations have a different structure (the parameters are not
829     // inside a bracket scope).
830     if (Current->is(tok::l_brace) && Current->is(BK_Block))
831       ++Left->BlockParameterCount;
832     if (Current->is(tok::comma)) {
833       ++Left->ParameterCount;
834       if (!Left->Role)
835         Left->Role.reset(new CommaSeparatedList(Style));
836       Left->Role->CommaFound(Current);
837     } else if (Left->ParameterCount == 0 && Current->isNot(tok::comment)) {
838       Left->ParameterCount = 1;
839     }
840   }
841 
842   bool parseConditional() {
843     while (CurrentToken) {
844       if (CurrentToken->is(tok::colon)) {
845         CurrentToken->setType(TT_ConditionalExpr);
846         next();
847         return true;
848       }
849       if (!consumeToken())
850         return false;
851     }
852     return false;
853   }
854 
855   bool parseTemplateDeclaration() {
856     if (CurrentToken && CurrentToken->is(tok::less)) {
857       CurrentToken->setType(TT_TemplateOpener);
858       next();
859       if (!parseAngle())
860         return false;
861       if (CurrentToken)
862         CurrentToken->Previous->ClosesTemplateDeclaration = true;
863       return true;
864     }
865     return false;
866   }
867 
868   bool consumeToken() {
869     FormatToken *Tok = CurrentToken;
870     next();
871     switch (Tok->Tok.getKind()) {
872     case tok::plus:
873     case tok::minus:
874       if (!Tok->Previous && Line.MustBeDeclaration)
875         Tok->setType(TT_ObjCMethodSpecifier);
876       break;
877     case tok::colon:
878       if (!Tok->Previous)
879         return false;
880       // Colons from ?: are handled in parseConditional().
881       if (Style.Language == FormatStyle::LK_JavaScript) {
882         if (Contexts.back().ColonIsForRangeExpr || // colon in for loop
883             (Contexts.size() == 1 &&               // switch/case labels
884              !Line.First->isOneOf(tok::kw_enum, tok::kw_case)) ||
885             Contexts.back().ContextKind == tok::l_paren ||  // function params
886             Contexts.back().ContextKind == tok::l_square || // array type
887             (!Contexts.back().IsExpression &&
888              Contexts.back().ContextKind == tok::l_brace) || // object type
889             (Contexts.size() == 1 &&
890              Line.MustBeDeclaration)) { // method/property declaration
891           Contexts.back().IsExpression = false;
892           Tok->setType(TT_JsTypeColon);
893           break;
894         }
895       } else if (Style.isCSharp()) {
896         if (Contexts.back().InCSharpAttributeSpecifier) {
897           Tok->setType(TT_AttributeColon);
898           break;
899         }
900         if (Contexts.back().ContextKind == tok::l_paren) {
901           Tok->setType(TT_CSharpNamedArgumentColon);
902           break;
903         }
904       }
905       if (Contexts.back().ColonIsDictLiteral ||
906           Style.Language == FormatStyle::LK_Proto ||
907           Style.Language == FormatStyle::LK_TextProto) {
908         Tok->setType(TT_DictLiteral);
909         if (Style.Language == FormatStyle::LK_TextProto) {
910           if (FormatToken *Previous = Tok->getPreviousNonComment())
911             Previous->setType(TT_SelectorName);
912         }
913       } else if (Contexts.back().ColonIsObjCMethodExpr ||
914                  Line.startsWith(TT_ObjCMethodSpecifier)) {
915         Tok->setType(TT_ObjCMethodExpr);
916         const FormatToken *BeforePrevious = Tok->Previous->Previous;
917         // Ensure we tag all identifiers in method declarations as
918         // TT_SelectorName.
919         bool UnknownIdentifierInMethodDeclaration =
920             Line.startsWith(TT_ObjCMethodSpecifier) &&
921             Tok->Previous->is(tok::identifier) && Tok->Previous->is(TT_Unknown);
922         if (!BeforePrevious ||
923             // FIXME(bug 36976): ObjC return types shouldn't use TT_CastRParen.
924             !(BeforePrevious->is(TT_CastRParen) ||
925               (BeforePrevious->is(TT_ObjCMethodExpr) &&
926                BeforePrevious->is(tok::colon))) ||
927             BeforePrevious->is(tok::r_square) ||
928             Contexts.back().LongestObjCSelectorName == 0 ||
929             UnknownIdentifierInMethodDeclaration) {
930           Tok->Previous->setType(TT_SelectorName);
931           if (!Contexts.back().FirstObjCSelectorName)
932             Contexts.back().FirstObjCSelectorName = Tok->Previous;
933           else if (Tok->Previous->ColumnWidth >
934                    Contexts.back().LongestObjCSelectorName)
935             Contexts.back().LongestObjCSelectorName =
936                 Tok->Previous->ColumnWidth;
937           Tok->Previous->ParameterIndex =
938               Contexts.back().FirstObjCSelectorName->ObjCSelectorNameParts;
939           ++Contexts.back().FirstObjCSelectorName->ObjCSelectorNameParts;
940         }
941       } else if (Contexts.back().ColonIsForRangeExpr) {
942         Tok->setType(TT_RangeBasedForLoopColon);
943       } else if (CurrentToken && CurrentToken->is(tok::numeric_constant)) {
944         Tok->setType(TT_BitFieldColon);
945       } else if (Contexts.size() == 1 &&
946                  !Line.First->isOneOf(tok::kw_enum, tok::kw_case,
947                                       tok::kw_default)) {
948         FormatToken *Prev = Tok->getPreviousNonComment();
949         if (Prev->isOneOf(tok::r_paren, tok::kw_noexcept))
950           Tok->setType(TT_CtorInitializerColon);
951         else if (Prev->is(tok::kw_try)) {
952           // Member initializer list within function try block.
953           FormatToken *PrevPrev = Prev->getPreviousNonComment();
954           if (PrevPrev && PrevPrev->isOneOf(tok::r_paren, tok::kw_noexcept))
955             Tok->setType(TT_CtorInitializerColon);
956         } else
957           Tok->setType(TT_InheritanceColon);
958       } else if (canBeObjCSelectorComponent(*Tok->Previous) && Tok->Next &&
959                  (Tok->Next->isOneOf(tok::r_paren, tok::comma) ||
960                   (canBeObjCSelectorComponent(*Tok->Next) && Tok->Next->Next &&
961                    Tok->Next->Next->is(tok::colon)))) {
962         // This handles a special macro in ObjC code where selectors including
963         // the colon are passed as macro arguments.
964         Tok->setType(TT_ObjCMethodExpr);
965       } else if (Contexts.back().ContextKind == tok::l_paren) {
966         Tok->setType(TT_InlineASMColon);
967       }
968       break;
969     case tok::pipe:
970     case tok::amp:
971       // | and & in declarations/type expressions represent union and
972       // intersection types, respectively.
973       if (Style.Language == FormatStyle::LK_JavaScript &&
974           !Contexts.back().IsExpression)
975         Tok->setType(TT_JsTypeOperator);
976       break;
977     case tok::kw_if:
978     case tok::kw_while:
979       if (Tok->is(tok::kw_if) && CurrentToken &&
980           CurrentToken->isOneOf(tok::kw_constexpr, tok::identifier))
981         next();
982       if (CurrentToken && CurrentToken->is(tok::l_paren)) {
983         next();
984         if (!parseParens(/*LookForDecls=*/true))
985           return false;
986       }
987       break;
988     case tok::kw_for:
989       if (Style.Language == FormatStyle::LK_JavaScript) {
990         // x.for and {for: ...}
991         if ((Tok->Previous && Tok->Previous->is(tok::period)) ||
992             (Tok->Next && Tok->Next->is(tok::colon)))
993           break;
994         // JS' for await ( ...
995         if (CurrentToken && CurrentToken->is(Keywords.kw_await))
996           next();
997       }
998       Contexts.back().ColonIsForRangeExpr = true;
999       next();
1000       if (!parseParens())
1001         return false;
1002       break;
1003     case tok::l_paren:
1004       // When faced with 'operator()()', the kw_operator handler incorrectly
1005       // marks the first l_paren as a OverloadedOperatorLParen. Here, we make
1006       // the first two parens OverloadedOperators and the second l_paren an
1007       // OverloadedOperatorLParen.
1008       if (Tok->Previous && Tok->Previous->is(tok::r_paren) &&
1009           Tok->Previous->MatchingParen &&
1010           Tok->Previous->MatchingParen->is(TT_OverloadedOperatorLParen)) {
1011         Tok->Previous->setType(TT_OverloadedOperator);
1012         Tok->Previous->MatchingParen->setType(TT_OverloadedOperator);
1013         Tok->setType(TT_OverloadedOperatorLParen);
1014       }
1015 
1016       if (!parseParens())
1017         return false;
1018       if (Line.MustBeDeclaration && Contexts.size() == 1 &&
1019           !Contexts.back().IsExpression && !Line.startsWith(TT_ObjCProperty) &&
1020           !Tok->is(TT_TypeDeclarationParen) &&
1021           (!Tok->Previous || !Tok->Previous->isOneOf(tok::kw___attribute,
1022                                                      TT_LeadingJavaAnnotation)))
1023         Line.MightBeFunctionDecl = true;
1024       break;
1025     case tok::l_square:
1026       if (!parseSquare())
1027         return false;
1028       break;
1029     case tok::l_brace:
1030       if (Style.Language == FormatStyle::LK_TextProto) {
1031         FormatToken *Previous = Tok->getPreviousNonComment();
1032         if (Previous && Previous->getType() != TT_DictLiteral)
1033           Previous->setType(TT_SelectorName);
1034       }
1035       if (!parseBrace())
1036         return false;
1037       break;
1038     case tok::less:
1039       if (parseAngle()) {
1040         Tok->setType(TT_TemplateOpener);
1041         // In TT_Proto, we must distignuish between:
1042         //   map<key, value>
1043         //   msg < item: data >
1044         //   msg: < item: data >
1045         // In TT_TextProto, map<key, value> does not occur.
1046         if (Style.Language == FormatStyle::LK_TextProto ||
1047             (Style.Language == FormatStyle::LK_Proto && Tok->Previous &&
1048              Tok->Previous->isOneOf(TT_SelectorName, TT_DictLiteral))) {
1049           Tok->setType(TT_DictLiteral);
1050           FormatToken *Previous = Tok->getPreviousNonComment();
1051           if (Previous && Previous->getType() != TT_DictLiteral)
1052             Previous->setType(TT_SelectorName);
1053         }
1054       } else {
1055         Tok->setType(TT_BinaryOperator);
1056         NonTemplateLess.insert(Tok);
1057         CurrentToken = Tok;
1058         next();
1059       }
1060       break;
1061     case tok::r_paren:
1062     case tok::r_square:
1063       return false;
1064     case tok::r_brace:
1065       // Lines can start with '}'.
1066       if (Tok->Previous)
1067         return false;
1068       break;
1069     case tok::greater:
1070       if (Style.Language != FormatStyle::LK_TextProto)
1071         Tok->setType(TT_BinaryOperator);
1072       if (Tok->Previous && Tok->Previous->is(TT_TemplateCloser))
1073         Tok->SpacesRequiredBefore = 1;
1074       break;
1075     case tok::kw_operator:
1076       if (Style.Language == FormatStyle::LK_TextProto ||
1077           Style.Language == FormatStyle::LK_Proto)
1078         break;
1079       while (CurrentToken &&
1080              !CurrentToken->isOneOf(tok::l_paren, tok::semi, tok::r_paren)) {
1081         if (CurrentToken->isOneOf(tok::star, tok::amp))
1082           CurrentToken->setType(TT_PointerOrReference);
1083         consumeToken();
1084         if (CurrentToken && CurrentToken->is(tok::comma) &&
1085             CurrentToken->Previous->isNot(tok::kw_operator))
1086           break;
1087         if (CurrentToken && CurrentToken->Previous->isOneOf(
1088                                 TT_BinaryOperator, TT_UnaryOperator, tok::comma,
1089                                 tok::star, tok::arrow, tok::amp, tok::ampamp))
1090           CurrentToken->Previous->setType(TT_OverloadedOperator);
1091       }
1092       if (CurrentToken && CurrentToken->is(tok::l_paren))
1093         CurrentToken->setType(TT_OverloadedOperatorLParen);
1094       if (CurrentToken && CurrentToken->Previous->is(TT_BinaryOperator))
1095         CurrentToken->Previous->setType(TT_OverloadedOperator);
1096       break;
1097     case tok::question:
1098       if (Style.Language == FormatStyle::LK_JavaScript && Tok->Next &&
1099           Tok->Next->isOneOf(tok::semi, tok::comma, tok::colon, tok::r_paren,
1100                              tok::r_brace)) {
1101         // Question marks before semicolons, colons, etc. indicate optional
1102         // types (fields, parameters), e.g.
1103         //   function(x?: string, y?) {...}
1104         //   class X { y?; }
1105         Tok->setType(TT_JsTypeOptionalQuestion);
1106         break;
1107       }
1108       // Declarations cannot be conditional expressions, this can only be part
1109       // of a type declaration.
1110       if (Line.MustBeDeclaration && !Contexts.back().IsExpression &&
1111           Style.Language == FormatStyle::LK_JavaScript)
1112         break;
1113       if (Style.isCSharp()) {
1114         // `Type?)`, `Type?>`, `Type? name;` and `Type? name =` can only be
1115         // nullable types.
1116         // Line.MustBeDeclaration will be true for `Type? name;`.
1117         if ((!Contexts.back().IsExpression && Line.MustBeDeclaration) ||
1118             (Tok->Next && Tok->Next->isOneOf(tok::r_paren, tok::greater)) ||
1119             (Tok->Next && Tok->Next->is(tok::identifier) && Tok->Next->Next &&
1120              Tok->Next->Next->is(tok::equal))) {
1121           Tok->setType(TT_CSharpNullable);
1122           break;
1123         }
1124       }
1125       parseConditional();
1126       break;
1127     case tok::kw_template:
1128       parseTemplateDeclaration();
1129       break;
1130     case tok::comma:
1131       if (Contexts.back().InCtorInitializer)
1132         Tok->setType(TT_CtorInitializerComma);
1133       else if (Contexts.back().InInheritanceList)
1134         Tok->setType(TT_InheritanceComma);
1135       else if (Contexts.back().FirstStartOfName &&
1136                (Contexts.size() == 1 || Line.startsWith(tok::kw_for))) {
1137         Contexts.back().FirstStartOfName->PartOfMultiVariableDeclStmt = true;
1138         Line.IsMultiVariableDeclStmt = true;
1139       }
1140       if (Contexts.back().IsForEachMacro)
1141         Contexts.back().IsExpression = true;
1142       break;
1143     case tok::identifier:
1144       if (Tok->isOneOf(Keywords.kw___has_include,
1145                        Keywords.kw___has_include_next)) {
1146         parseHasInclude();
1147       }
1148       if (Style.isCSharp() && Tok->is(Keywords.kw_where) && Tok->Next &&
1149           Tok->Next->isNot(tok::l_paren)) {
1150         Tok->setType(TT_CSharpGenericTypeConstraint);
1151         parseCSharpGenericTypeConstraint();
1152       }
1153       break;
1154     default:
1155       break;
1156     }
1157     return true;
1158   }
1159 
1160   void parseCSharpGenericTypeConstraint() {
1161     int OpenAngleBracketsCount = 0;
1162     while (CurrentToken) {
1163       if (CurrentToken->is(tok::less)) {
1164         // parseAngle is too greedy and will consume the whole line.
1165         CurrentToken->setType(TT_TemplateOpener);
1166         ++OpenAngleBracketsCount;
1167         next();
1168       } else if (CurrentToken->is(tok::greater)) {
1169         CurrentToken->setType(TT_TemplateCloser);
1170         --OpenAngleBracketsCount;
1171         next();
1172       } else if (CurrentToken->is(tok::comma) && OpenAngleBracketsCount == 0) {
1173         // We allow line breaks after GenericTypeConstraintComma's
1174         // so do not flag commas in Generics as GenericTypeConstraintComma's.
1175         CurrentToken->setType(TT_CSharpGenericTypeConstraintComma);
1176         next();
1177       } else if (CurrentToken->is(Keywords.kw_where)) {
1178         CurrentToken->setType(TT_CSharpGenericTypeConstraint);
1179         next();
1180       } else if (CurrentToken->is(tok::colon)) {
1181         CurrentToken->setType(TT_CSharpGenericTypeConstraintColon);
1182         next();
1183       } else {
1184         next();
1185       }
1186     }
1187   }
1188 
1189   void parseIncludeDirective() {
1190     if (CurrentToken && CurrentToken->is(tok::less)) {
1191       next();
1192       while (CurrentToken) {
1193         // Mark tokens up to the trailing line comments as implicit string
1194         // literals.
1195         if (CurrentToken->isNot(tok::comment) &&
1196             !CurrentToken->TokenText.startswith("//"))
1197           CurrentToken->setType(TT_ImplicitStringLiteral);
1198         next();
1199       }
1200     }
1201   }
1202 
1203   void parseWarningOrError() {
1204     next();
1205     // We still want to format the whitespace left of the first token of the
1206     // warning or error.
1207     next();
1208     while (CurrentToken) {
1209       CurrentToken->setType(TT_ImplicitStringLiteral);
1210       next();
1211     }
1212   }
1213 
1214   void parsePragma() {
1215     next(); // Consume "pragma".
1216     if (CurrentToken &&
1217         CurrentToken->isOneOf(Keywords.kw_mark, Keywords.kw_option)) {
1218       bool IsMark = CurrentToken->is(Keywords.kw_mark);
1219       next(); // Consume "mark".
1220       next(); // Consume first token (so we fix leading whitespace).
1221       while (CurrentToken) {
1222         if (IsMark || CurrentToken->Previous->is(TT_BinaryOperator))
1223           CurrentToken->setType(TT_ImplicitStringLiteral);
1224         next();
1225       }
1226     }
1227   }
1228 
1229   void parseHasInclude() {
1230     if (!CurrentToken || !CurrentToken->is(tok::l_paren))
1231       return;
1232     next(); // '('
1233     parseIncludeDirective();
1234     next(); // ')'
1235   }
1236 
1237   LineType parsePreprocessorDirective() {
1238     bool IsFirstToken = CurrentToken->IsFirst;
1239     LineType Type = LT_PreprocessorDirective;
1240     next();
1241     if (!CurrentToken)
1242       return Type;
1243 
1244     if (Style.Language == FormatStyle::LK_JavaScript && IsFirstToken) {
1245       // JavaScript files can contain shebang lines of the form:
1246       // #!/usr/bin/env node
1247       // Treat these like C++ #include directives.
1248       while (CurrentToken) {
1249         // Tokens cannot be comments here.
1250         CurrentToken->setType(TT_ImplicitStringLiteral);
1251         next();
1252       }
1253       return LT_ImportStatement;
1254     }
1255 
1256     if (CurrentToken->Tok.is(tok::numeric_constant)) {
1257       CurrentToken->SpacesRequiredBefore = 1;
1258       return Type;
1259     }
1260     // Hashes in the middle of a line can lead to any strange token
1261     // sequence.
1262     if (!CurrentToken->Tok.getIdentifierInfo())
1263       return Type;
1264     switch (CurrentToken->Tok.getIdentifierInfo()->getPPKeywordID()) {
1265     case tok::pp_include:
1266     case tok::pp_include_next:
1267     case tok::pp_import:
1268       next();
1269       parseIncludeDirective();
1270       Type = LT_ImportStatement;
1271       break;
1272     case tok::pp_error:
1273     case tok::pp_warning:
1274       parseWarningOrError();
1275       break;
1276     case tok::pp_pragma:
1277       parsePragma();
1278       break;
1279     case tok::pp_if:
1280     case tok::pp_elif:
1281       Contexts.back().IsExpression = true;
1282       next();
1283       parseLine();
1284       break;
1285     default:
1286       break;
1287     }
1288     while (CurrentToken) {
1289       FormatToken *Tok = CurrentToken;
1290       next();
1291       if (Tok->is(tok::l_paren))
1292         parseParens();
1293       else if (Tok->isOneOf(Keywords.kw___has_include,
1294                             Keywords.kw___has_include_next))
1295         parseHasInclude();
1296     }
1297     return Type;
1298   }
1299 
1300 public:
1301   LineType parseLine() {
1302     if (!CurrentToken)
1303       return LT_Invalid;
1304     NonTemplateLess.clear();
1305     if (CurrentToken->is(tok::hash))
1306       return parsePreprocessorDirective();
1307 
1308     // Directly allow to 'import <string-literal>' to support protocol buffer
1309     // definitions (github.com/google/protobuf) or missing "#" (either way we
1310     // should not break the line).
1311     IdentifierInfo *Info = CurrentToken->Tok.getIdentifierInfo();
1312     if ((Style.Language == FormatStyle::LK_Java &&
1313          CurrentToken->is(Keywords.kw_package)) ||
1314         (Info && Info->getPPKeywordID() == tok::pp_import &&
1315          CurrentToken->Next &&
1316          CurrentToken->Next->isOneOf(tok::string_literal, tok::identifier,
1317                                      tok::kw_static))) {
1318       next();
1319       parseIncludeDirective();
1320       return LT_ImportStatement;
1321     }
1322 
1323     // If this line starts and ends in '<' and '>', respectively, it is likely
1324     // part of "#define <a/b.h>".
1325     if (CurrentToken->is(tok::less) && Line.Last->is(tok::greater)) {
1326       parseIncludeDirective();
1327       return LT_ImportStatement;
1328     }
1329 
1330     // In .proto files, top-level options and package statements are very
1331     // similar to import statements and should not be line-wrapped.
1332     if (Style.Language == FormatStyle::LK_Proto && Line.Level == 0 &&
1333         CurrentToken->isOneOf(Keywords.kw_option, Keywords.kw_package)) {
1334       next();
1335       if (CurrentToken && CurrentToken->is(tok::identifier)) {
1336         while (CurrentToken)
1337           next();
1338         return LT_ImportStatement;
1339       }
1340     }
1341 
1342     bool KeywordVirtualFound = false;
1343     bool ImportStatement = false;
1344 
1345     // import {...} from '...';
1346     if (Style.Language == FormatStyle::LK_JavaScript &&
1347         CurrentToken->is(Keywords.kw_import))
1348       ImportStatement = true;
1349 
1350     while (CurrentToken) {
1351       if (CurrentToken->is(tok::kw_virtual))
1352         KeywordVirtualFound = true;
1353       if (Style.Language == FormatStyle::LK_JavaScript) {
1354         // export {...} from '...';
1355         // An export followed by "from 'some string';" is a re-export from
1356         // another module identified by a URI and is treated as a
1357         // LT_ImportStatement (i.e. prevent wraps on it for long URIs).
1358         // Just "export {...};" or "export class ..." should not be treated as
1359         // an import in this sense.
1360         if (Line.First->is(tok::kw_export) &&
1361             CurrentToken->is(Keywords.kw_from) && CurrentToken->Next &&
1362             CurrentToken->Next->isStringLiteral())
1363           ImportStatement = true;
1364         if (isClosureImportStatement(*CurrentToken))
1365           ImportStatement = true;
1366       }
1367       if (!consumeToken())
1368         return LT_Invalid;
1369     }
1370     if (KeywordVirtualFound)
1371       return LT_VirtualFunctionDecl;
1372     if (ImportStatement)
1373       return LT_ImportStatement;
1374 
1375     if (Line.startsWith(TT_ObjCMethodSpecifier)) {
1376       if (Contexts.back().FirstObjCSelectorName)
1377         Contexts.back().FirstObjCSelectorName->LongestObjCSelectorName =
1378             Contexts.back().LongestObjCSelectorName;
1379       return LT_ObjCMethodDecl;
1380     }
1381 
1382     for (const auto &ctx : Contexts) {
1383       if (ctx.InStructArrayInitializer) {
1384         return LT_ArrayOfStructInitializer;
1385       }
1386     }
1387 
1388     return LT_Other;
1389   }
1390 
1391 private:
1392   bool isClosureImportStatement(const FormatToken &Tok) {
1393     // FIXME: Closure-library specific stuff should not be hard-coded but be
1394     // configurable.
1395     return Tok.TokenText == "goog" && Tok.Next && Tok.Next->is(tok::period) &&
1396            Tok.Next->Next &&
1397            (Tok.Next->Next->TokenText == "module" ||
1398             Tok.Next->Next->TokenText == "provide" ||
1399             Tok.Next->Next->TokenText == "require" ||
1400             Tok.Next->Next->TokenText == "requireType" ||
1401             Tok.Next->Next->TokenText == "forwardDeclare") &&
1402            Tok.Next->Next->Next && Tok.Next->Next->Next->is(tok::l_paren);
1403   }
1404 
1405   void resetTokenMetadata(FormatToken *Token) {
1406     if (!Token)
1407       return;
1408 
1409     // Reset token type in case we have already looked at it and then
1410     // recovered from an error (e.g. failure to find the matching >).
1411     if (!CurrentToken->isOneOf(
1412             TT_LambdaLSquare, TT_LambdaLBrace, TT_AttributeMacro, TT_IfMacro,
1413             TT_ForEachMacro, TT_TypenameMacro, TT_FunctionLBrace,
1414             TT_ImplicitStringLiteral, TT_InlineASMBrace, TT_FatArrow,
1415             TT_LambdaArrow, TT_NamespaceMacro, TT_OverloadedOperator,
1416             TT_RegexLiteral, TT_TemplateString, TT_ObjCStringLiteral,
1417             TT_UntouchableMacroFunc, TT_ConstraintJunctions,
1418             TT_StatementAttributeLikeMacro))
1419       CurrentToken->setType(TT_Unknown);
1420     CurrentToken->Role.reset();
1421     CurrentToken->MatchingParen = nullptr;
1422     CurrentToken->FakeLParens.clear();
1423     CurrentToken->FakeRParens = 0;
1424   }
1425 
1426   void next() {
1427     if (CurrentToken) {
1428       CurrentToken->NestingLevel = Contexts.size() - 1;
1429       CurrentToken->BindingStrength = Contexts.back().BindingStrength;
1430       modifyContext(*CurrentToken);
1431       determineTokenType(*CurrentToken);
1432       CurrentToken = CurrentToken->Next;
1433     }
1434 
1435     resetTokenMetadata(CurrentToken);
1436   }
1437 
1438   /// A struct to hold information valid in a specific context, e.g.
1439   /// a pair of parenthesis.
1440   struct Context {
1441     Context(tok::TokenKind ContextKind, unsigned BindingStrength,
1442             bool IsExpression)
1443         : ContextKind(ContextKind), BindingStrength(BindingStrength),
1444           IsExpression(IsExpression) {}
1445 
1446     tok::TokenKind ContextKind;
1447     unsigned BindingStrength;
1448     bool IsExpression;
1449     unsigned LongestObjCSelectorName = 0;
1450     bool ColonIsForRangeExpr = false;
1451     bool ColonIsDictLiteral = false;
1452     bool ColonIsObjCMethodExpr = false;
1453     FormatToken *FirstObjCSelectorName = nullptr;
1454     FormatToken *FirstStartOfName = nullptr;
1455     bool CanBeExpression = true;
1456     bool InTemplateArgument = false;
1457     bool InCtorInitializer = false;
1458     bool InInheritanceList = false;
1459     bool CaretFound = false;
1460     bool IsForEachMacro = false;
1461     bool InCpp11AttributeSpecifier = false;
1462     bool InCSharpAttributeSpecifier = false;
1463     bool InStructArrayInitializer = false;
1464   };
1465 
1466   /// Puts a new \c Context onto the stack \c Contexts for the lifetime
1467   /// of each instance.
1468   struct ScopedContextCreator {
1469     AnnotatingParser &P;
1470 
1471     ScopedContextCreator(AnnotatingParser &P, tok::TokenKind ContextKind,
1472                          unsigned Increase)
1473         : P(P) {
1474       P.Contexts.push_back(Context(ContextKind,
1475                                    P.Contexts.back().BindingStrength + Increase,
1476                                    P.Contexts.back().IsExpression));
1477     }
1478 
1479     ~ScopedContextCreator() {
1480       if (P.Style.AlignArrayOfStructures != FormatStyle::AIAS_None) {
1481         if (P.Contexts.back().InStructArrayInitializer) {
1482           P.Contexts.pop_back();
1483           P.Contexts.back().InStructArrayInitializer = true;
1484           return;
1485         }
1486       }
1487       P.Contexts.pop_back();
1488     }
1489   };
1490 
1491   void modifyContext(const FormatToken &Current) {
1492     if (Current.getPrecedence() == prec::Assignment &&
1493         !Line.First->isOneOf(tok::kw_template, tok::kw_using, tok::kw_return) &&
1494         // Type aliases use `type X = ...;` in TypeScript and can be exported
1495         // using `export type ...`.
1496         !(Style.Language == FormatStyle::LK_JavaScript &&
1497           (Line.startsWith(Keywords.kw_type, tok::identifier) ||
1498            Line.startsWith(tok::kw_export, Keywords.kw_type,
1499                            tok::identifier))) &&
1500         (!Current.Previous || Current.Previous->isNot(tok::kw_operator))) {
1501       Contexts.back().IsExpression = true;
1502       if (!Line.startsWith(TT_UnaryOperator)) {
1503         for (FormatToken *Previous = Current.Previous;
1504              Previous && Previous->Previous &&
1505              !Previous->Previous->isOneOf(tok::comma, tok::semi);
1506              Previous = Previous->Previous) {
1507           if (Previous->isOneOf(tok::r_square, tok::r_paren)) {
1508             Previous = Previous->MatchingParen;
1509             if (!Previous)
1510               break;
1511           }
1512           if (Previous->opensScope())
1513             break;
1514           if (Previous->isOneOf(TT_BinaryOperator, TT_UnaryOperator) &&
1515               Previous->isOneOf(tok::star, tok::amp, tok::ampamp) &&
1516               Previous->Previous && Previous->Previous->isNot(tok::equal))
1517             Previous->setType(TT_PointerOrReference);
1518         }
1519       }
1520     } else if (Current.is(tok::lessless) &&
1521                (!Current.Previous || !Current.Previous->is(tok::kw_operator))) {
1522       Contexts.back().IsExpression = true;
1523     } else if (Current.isOneOf(tok::kw_return, tok::kw_throw)) {
1524       Contexts.back().IsExpression = true;
1525     } else if (Current.is(TT_TrailingReturnArrow)) {
1526       Contexts.back().IsExpression = false;
1527     } else if (Current.is(TT_LambdaArrow) || Current.is(Keywords.kw_assert)) {
1528       Contexts.back().IsExpression = Style.Language == FormatStyle::LK_Java;
1529     } else if (Current.Previous &&
1530                Current.Previous->is(TT_CtorInitializerColon)) {
1531       Contexts.back().IsExpression = true;
1532       Contexts.back().InCtorInitializer = true;
1533     } else if (Current.Previous && Current.Previous->is(TT_InheritanceColon)) {
1534       Contexts.back().InInheritanceList = true;
1535     } else if (Current.isOneOf(tok::r_paren, tok::greater, tok::comma)) {
1536       for (FormatToken *Previous = Current.Previous;
1537            Previous && Previous->isOneOf(tok::star, tok::amp);
1538            Previous = Previous->Previous)
1539         Previous->setType(TT_PointerOrReference);
1540       if (Line.MustBeDeclaration && !Contexts.front().InCtorInitializer)
1541         Contexts.back().IsExpression = false;
1542     } else if (Current.is(tok::kw_new)) {
1543       Contexts.back().CanBeExpression = false;
1544     } else if (Current.is(tok::semi) ||
1545                (Current.is(tok::exclaim) && Current.Previous &&
1546                 !Current.Previous->is(tok::kw_operator))) {
1547       // This should be the condition or increment in a for-loop.
1548       // But not operator !() (can't use TT_OverloadedOperator here as its not
1549       // been annotated yet).
1550       Contexts.back().IsExpression = true;
1551     }
1552   }
1553 
1554   static FormatToken *untilMatchingParen(FormatToken *Current) {
1555     // Used when `MatchingParen` is not yet established.
1556     int ParenLevel = 0;
1557     while (Current) {
1558       if (Current->is(tok::l_paren))
1559         ParenLevel++;
1560       if (Current->is(tok::r_paren))
1561         ParenLevel--;
1562       if (ParenLevel < 1)
1563         break;
1564       Current = Current->Next;
1565     }
1566     return Current;
1567   }
1568 
1569   static bool isDeductionGuide(FormatToken &Current) {
1570     // Look for a deduction guide template<T> A(...) -> A<...>;
1571     if (Current.Previous && Current.Previous->is(tok::r_paren) &&
1572         Current.startsSequence(tok::arrow, tok::identifier, tok::less)) {
1573       // Find the TemplateCloser.
1574       FormatToken *TemplateCloser = Current.Next->Next;
1575       int NestingLevel = 0;
1576       while (TemplateCloser) {
1577         // Skip over an expressions in parens  A<(3 < 2)>;
1578         if (TemplateCloser->is(tok::l_paren)) {
1579           // No Matching Paren yet so skip to matching paren
1580           TemplateCloser = untilMatchingParen(TemplateCloser);
1581         }
1582         if (TemplateCloser->is(tok::less))
1583           NestingLevel++;
1584         if (TemplateCloser->is(tok::greater))
1585           NestingLevel--;
1586         if (NestingLevel < 1)
1587           break;
1588         TemplateCloser = TemplateCloser->Next;
1589       }
1590       // Assuming we have found the end of the template ensure its followed
1591       // with a semi-colon.
1592       if (TemplateCloser && TemplateCloser->Next &&
1593           TemplateCloser->Next->is(tok::semi) &&
1594           Current.Previous->MatchingParen) {
1595         // Determine if the identifier `A` prior to the A<..>; is the same as
1596         // prior to the A(..)
1597         FormatToken *LeadingIdentifier =
1598             Current.Previous->MatchingParen->Previous;
1599 
1600         // Differentiate a deduction guide by seeing the
1601         // > of the template prior to the leading identifier.
1602         if (LeadingIdentifier) {
1603           FormatToken *PriorLeadingIdentifier = LeadingIdentifier->Previous;
1604           // Skip back past explicit decoration
1605           if (PriorLeadingIdentifier &&
1606               PriorLeadingIdentifier->is(tok::kw_explicit))
1607             PriorLeadingIdentifier = PriorLeadingIdentifier->Previous;
1608 
1609           return (PriorLeadingIdentifier &&
1610                   PriorLeadingIdentifier->is(TT_TemplateCloser) &&
1611                   LeadingIdentifier->TokenText == Current.Next->TokenText);
1612         }
1613       }
1614     }
1615     return false;
1616   }
1617 
1618   void determineTokenType(FormatToken &Current) {
1619     if (!Current.is(TT_Unknown))
1620       // The token type is already known.
1621       return;
1622 
1623     if ((Style.Language == FormatStyle::LK_JavaScript || Style.isCSharp()) &&
1624         Current.is(tok::exclaim)) {
1625       if (Current.Previous) {
1626         bool IsIdentifier =
1627             Style.Language == FormatStyle::LK_JavaScript
1628                 ? Keywords.IsJavaScriptIdentifier(
1629                       *Current.Previous, /* AcceptIdentifierName= */ true)
1630                 : Current.Previous->is(tok::identifier);
1631         if (IsIdentifier ||
1632             Current.Previous->isOneOf(
1633                 tok::kw_namespace, tok::r_paren, tok::r_square, tok::r_brace,
1634                 tok::kw_false, tok::kw_true, Keywords.kw_type, Keywords.kw_get,
1635                 Keywords.kw_set) ||
1636             Current.Previous->Tok.isLiteral()) {
1637           Current.setType(TT_NonNullAssertion);
1638           return;
1639         }
1640       }
1641       if (Current.Next &&
1642           Current.Next->isOneOf(TT_BinaryOperator, Keywords.kw_as)) {
1643         Current.setType(TT_NonNullAssertion);
1644         return;
1645       }
1646     }
1647 
1648     // Line.MightBeFunctionDecl can only be true after the parentheses of a
1649     // function declaration have been found. In this case, 'Current' is a
1650     // trailing token of this declaration and thus cannot be a name.
1651     if (Current.is(Keywords.kw_instanceof)) {
1652       Current.setType(TT_BinaryOperator);
1653     } else if (isStartOfName(Current) &&
1654                (!Line.MightBeFunctionDecl || Current.NestingLevel != 0)) {
1655       Contexts.back().FirstStartOfName = &Current;
1656       Current.setType(TT_StartOfName);
1657     } else if (Current.is(tok::semi)) {
1658       // Reset FirstStartOfName after finding a semicolon so that a for loop
1659       // with multiple increment statements is not confused with a for loop
1660       // having multiple variable declarations.
1661       Contexts.back().FirstStartOfName = nullptr;
1662     } else if (Current.isOneOf(tok::kw_auto, tok::kw___auto_type)) {
1663       AutoFound = true;
1664     } else if (Current.is(tok::arrow) &&
1665                Style.Language == FormatStyle::LK_Java) {
1666       Current.setType(TT_LambdaArrow);
1667     } else if (Current.is(tok::arrow) && AutoFound && Line.MustBeDeclaration &&
1668                Current.NestingLevel == 0 &&
1669                !Current.Previous->is(tok::kw_operator)) {
1670       // not auto operator->() -> xxx;
1671       Current.setType(TT_TrailingReturnArrow);
1672     } else if (Current.is(tok::arrow) && Current.Previous &&
1673                Current.Previous->is(tok::r_brace)) {
1674       // Concept implicit conversion contraint needs to be treated like
1675       // a trailing return type  ... } -> <type>.
1676       Current.setType(TT_TrailingReturnArrow);
1677     } else if (isDeductionGuide(Current)) {
1678       // Deduction guides trailing arrow " A(...) -> A<T>;".
1679       Current.setType(TT_TrailingReturnArrow);
1680     } else if (Current.isOneOf(tok::star, tok::amp, tok::ampamp)) {
1681       Current.setType(determineStarAmpUsage(
1682           Current,
1683           Contexts.back().CanBeExpression && Contexts.back().IsExpression,
1684           Contexts.back().InTemplateArgument));
1685     } else if (Current.isOneOf(tok::minus, tok::plus, tok::caret)) {
1686       Current.setType(determinePlusMinusCaretUsage(Current));
1687       if (Current.is(TT_UnaryOperator) && Current.is(tok::caret))
1688         Contexts.back().CaretFound = true;
1689     } else if (Current.isOneOf(tok::minusminus, tok::plusplus)) {
1690       Current.setType(determineIncrementUsage(Current));
1691     } else if (Current.isOneOf(tok::exclaim, tok::tilde)) {
1692       Current.setType(TT_UnaryOperator);
1693     } else if (Current.is(tok::question)) {
1694       if (Style.Language == FormatStyle::LK_JavaScript &&
1695           Line.MustBeDeclaration && !Contexts.back().IsExpression) {
1696         // In JavaScript, `interface X { foo?(): bar; }` is an optional method
1697         // on the interface, not a ternary expression.
1698         Current.setType(TT_JsTypeOptionalQuestion);
1699       } else {
1700         Current.setType(TT_ConditionalExpr);
1701       }
1702     } else if (Current.isBinaryOperator() &&
1703                (!Current.Previous || Current.Previous->isNot(tok::l_square)) &&
1704                (!Current.is(tok::greater) &&
1705                 Style.Language != FormatStyle::LK_TextProto)) {
1706       Current.setType(TT_BinaryOperator);
1707     } else if (Current.is(tok::comment)) {
1708       if (Current.TokenText.startswith("/*")) {
1709         if (Current.TokenText.endswith("*/"))
1710           Current.setType(TT_BlockComment);
1711         else
1712           // The lexer has for some reason determined a comment here. But we
1713           // cannot really handle it, if it isn't properly terminated.
1714           Current.Tok.setKind(tok::unknown);
1715       } else {
1716         Current.setType(TT_LineComment);
1717       }
1718     } else if (Current.is(tok::r_paren)) {
1719       if (rParenEndsCast(Current))
1720         Current.setType(TT_CastRParen);
1721       if (Current.MatchingParen && Current.Next &&
1722           !Current.Next->isBinaryOperator() &&
1723           !Current.Next->isOneOf(tok::semi, tok::colon, tok::l_brace,
1724                                  tok::comma, tok::period, tok::arrow,
1725                                  tok::coloncolon))
1726         if (FormatToken *AfterParen = Current.MatchingParen->Next) {
1727           // Make sure this isn't the return type of an Obj-C block declaration
1728           if (AfterParen->Tok.isNot(tok::caret)) {
1729             if (FormatToken *BeforeParen = Current.MatchingParen->Previous)
1730               if (BeforeParen->is(tok::identifier) &&
1731                   !BeforeParen->is(TT_TypenameMacro) &&
1732                   BeforeParen->TokenText == BeforeParen->TokenText.upper() &&
1733                   (!BeforeParen->Previous ||
1734                    BeforeParen->Previous->ClosesTemplateDeclaration))
1735                 Current.setType(TT_FunctionAnnotationRParen);
1736           }
1737         }
1738     } else if (Current.is(tok::at) && Current.Next &&
1739                Style.Language != FormatStyle::LK_JavaScript &&
1740                Style.Language != FormatStyle::LK_Java) {
1741       // In Java & JavaScript, "@..." is a decorator or annotation. In ObjC, it
1742       // marks declarations and properties that need special formatting.
1743       switch (Current.Next->Tok.getObjCKeywordID()) {
1744       case tok::objc_interface:
1745       case tok::objc_implementation:
1746       case tok::objc_protocol:
1747         Current.setType(TT_ObjCDecl);
1748         break;
1749       case tok::objc_property:
1750         Current.setType(TT_ObjCProperty);
1751         break;
1752       default:
1753         break;
1754       }
1755     } else if (Current.is(tok::period)) {
1756       FormatToken *PreviousNoComment = Current.getPreviousNonComment();
1757       if (PreviousNoComment &&
1758           PreviousNoComment->isOneOf(tok::comma, tok::l_brace))
1759         Current.setType(TT_DesignatedInitializerPeriod);
1760       else if (Style.Language == FormatStyle::LK_Java && Current.Previous &&
1761                Current.Previous->isOneOf(TT_JavaAnnotation,
1762                                          TT_LeadingJavaAnnotation)) {
1763         Current.setType(Current.Previous->getType());
1764       }
1765     } else if (canBeObjCSelectorComponent(Current) &&
1766                // FIXME(bug 36976): ObjC return types shouldn't use
1767                // TT_CastRParen.
1768                Current.Previous && Current.Previous->is(TT_CastRParen) &&
1769                Current.Previous->MatchingParen &&
1770                Current.Previous->MatchingParen->Previous &&
1771                Current.Previous->MatchingParen->Previous->is(
1772                    TT_ObjCMethodSpecifier)) {
1773       // This is the first part of an Objective-C selector name. (If there's no
1774       // colon after this, this is the only place which annotates the identifier
1775       // as a selector.)
1776       Current.setType(TT_SelectorName);
1777     } else if (Current.isOneOf(tok::identifier, tok::kw_const, tok::kw_noexcept,
1778                                tok::kw_requires) &&
1779                Current.Previous &&
1780                !Current.Previous->isOneOf(tok::equal, tok::at) &&
1781                Line.MightBeFunctionDecl && Contexts.size() == 1) {
1782       // Line.MightBeFunctionDecl can only be true after the parentheses of a
1783       // function declaration have been found.
1784       Current.setType(TT_TrailingAnnotation);
1785     } else if ((Style.Language == FormatStyle::LK_Java ||
1786                 Style.Language == FormatStyle::LK_JavaScript) &&
1787                Current.Previous) {
1788       if (Current.Previous->is(tok::at) &&
1789           Current.isNot(Keywords.kw_interface)) {
1790         const FormatToken &AtToken = *Current.Previous;
1791         const FormatToken *Previous = AtToken.getPreviousNonComment();
1792         if (!Previous || Previous->is(TT_LeadingJavaAnnotation))
1793           Current.setType(TT_LeadingJavaAnnotation);
1794         else
1795           Current.setType(TT_JavaAnnotation);
1796       } else if (Current.Previous->is(tok::period) &&
1797                  Current.Previous->isOneOf(TT_JavaAnnotation,
1798                                            TT_LeadingJavaAnnotation)) {
1799         Current.setType(Current.Previous->getType());
1800       }
1801     }
1802   }
1803 
1804   /// Take a guess at whether \p Tok starts a name of a function or
1805   /// variable declaration.
1806   ///
1807   /// This is a heuristic based on whether \p Tok is an identifier following
1808   /// something that is likely a type.
1809   bool isStartOfName(const FormatToken &Tok) {
1810     if (Tok.isNot(tok::identifier) || !Tok.Previous)
1811       return false;
1812 
1813     if (Tok.Previous->isOneOf(TT_LeadingJavaAnnotation, Keywords.kw_instanceof,
1814                               Keywords.kw_as))
1815       return false;
1816     if (Style.Language == FormatStyle::LK_JavaScript &&
1817         Tok.Previous->is(Keywords.kw_in))
1818       return false;
1819 
1820     // Skip "const" as it does not have an influence on whether this is a name.
1821     FormatToken *PreviousNotConst = Tok.getPreviousNonComment();
1822     while (PreviousNotConst && PreviousNotConst->is(tok::kw_const))
1823       PreviousNotConst = PreviousNotConst->getPreviousNonComment();
1824 
1825     if (!PreviousNotConst)
1826       return false;
1827 
1828     bool IsPPKeyword = PreviousNotConst->is(tok::identifier) &&
1829                        PreviousNotConst->Previous &&
1830                        PreviousNotConst->Previous->is(tok::hash);
1831 
1832     if (PreviousNotConst->is(TT_TemplateCloser))
1833       return PreviousNotConst && PreviousNotConst->MatchingParen &&
1834              PreviousNotConst->MatchingParen->Previous &&
1835              PreviousNotConst->MatchingParen->Previous->isNot(tok::period) &&
1836              PreviousNotConst->MatchingParen->Previous->isNot(tok::kw_template);
1837 
1838     if (PreviousNotConst->is(tok::r_paren) &&
1839         PreviousNotConst->is(TT_TypeDeclarationParen))
1840       return true;
1841 
1842     return (!IsPPKeyword &&
1843             PreviousNotConst->isOneOf(tok::identifier, tok::kw_auto)) ||
1844            PreviousNotConst->is(TT_PointerOrReference) ||
1845            PreviousNotConst->isSimpleTypeSpecifier();
1846   }
1847 
1848   /// Determine whether ')' is ending a cast.
1849   bool rParenEndsCast(const FormatToken &Tok) {
1850     // C-style casts are only used in C++, C# and Java.
1851     if (!Style.isCSharp() && !Style.isCpp() &&
1852         Style.Language != FormatStyle::LK_Java)
1853       return false;
1854 
1855     // Empty parens aren't casts and there are no casts at the end of the line.
1856     if (Tok.Previous == Tok.MatchingParen || !Tok.Next || !Tok.MatchingParen)
1857       return false;
1858 
1859     FormatToken *LeftOfParens = Tok.MatchingParen->getPreviousNonComment();
1860     if (LeftOfParens) {
1861       // If there is a closing parenthesis left of the current parentheses,
1862       // look past it as these might be chained casts.
1863       if (LeftOfParens->is(tok::r_paren)) {
1864         if (!LeftOfParens->MatchingParen ||
1865             !LeftOfParens->MatchingParen->Previous)
1866           return false;
1867         LeftOfParens = LeftOfParens->MatchingParen->Previous;
1868       }
1869 
1870       // If there is an identifier (or with a few exceptions a keyword) right
1871       // before the parentheses, this is unlikely to be a cast.
1872       if (LeftOfParens->Tok.getIdentifierInfo() &&
1873           !LeftOfParens->isOneOf(Keywords.kw_in, tok::kw_return, tok::kw_case,
1874                                  tok::kw_delete))
1875         return false;
1876 
1877       // Certain other tokens right before the parentheses are also signals that
1878       // this cannot be a cast.
1879       if (LeftOfParens->isOneOf(tok::at, tok::r_square, TT_OverloadedOperator,
1880                                 TT_TemplateCloser, tok::ellipsis))
1881         return false;
1882     }
1883 
1884     if (Tok.Next->is(tok::question))
1885       return false;
1886 
1887     // `foreach((A a, B b) in someList)` should not be seen as a cast.
1888     if (Tok.Next->is(Keywords.kw_in) && Style.isCSharp())
1889       return false;
1890 
1891     // Functions which end with decorations like volatile, noexcept are unlikely
1892     // to be casts.
1893     if (Tok.Next->isOneOf(tok::kw_noexcept, tok::kw_volatile, tok::kw_const,
1894                           tok::kw_requires, tok::kw_throw, tok::arrow,
1895                           Keywords.kw_override, Keywords.kw_final) ||
1896         isCpp11AttributeSpecifier(*Tok.Next))
1897       return false;
1898 
1899     // As Java has no function types, a "(" after the ")" likely means that this
1900     // is a cast.
1901     if (Style.Language == FormatStyle::LK_Java && Tok.Next->is(tok::l_paren))
1902       return true;
1903 
1904     // If a (non-string) literal follows, this is likely a cast.
1905     if (Tok.Next->isNot(tok::string_literal) &&
1906         (Tok.Next->Tok.isLiteral() ||
1907          Tok.Next->isOneOf(tok::kw_sizeof, tok::kw_alignof)))
1908       return true;
1909 
1910     // Heuristically try to determine whether the parentheses contain a type.
1911     auto IsQualifiedPointerOrReference = [](FormatToken *T) {
1912       // This is used to handle cases such as x = (foo *const)&y;
1913       assert(!T->isSimpleTypeSpecifier() && "Should have already been checked");
1914       // Strip trailing qualifiers such as const or volatile when checking
1915       // whether the parens could be a cast to a pointer/reference type.
1916       while (T) {
1917         if (T->is(TT_AttributeParen)) {
1918           // Handle `x = (foo *__attribute__((foo)))&v;`:
1919           if (T->MatchingParen && T->MatchingParen->Previous &&
1920               T->MatchingParen->Previous->is(tok::kw___attribute)) {
1921             T = T->MatchingParen->Previous->Previous;
1922             continue;
1923           }
1924         } else if (T->is(TT_AttributeSquare)) {
1925           // Handle `x = (foo *[[clang::foo]])&v;`:
1926           if (T->MatchingParen && T->MatchingParen->Previous) {
1927             T = T->MatchingParen->Previous;
1928             continue;
1929           }
1930         } else if (T->canBePointerOrReferenceQualifier()) {
1931           T = T->Previous;
1932           continue;
1933         }
1934         break;
1935       }
1936       return T && T->is(TT_PointerOrReference);
1937     };
1938     bool ParensAreType =
1939         !Tok.Previous ||
1940         Tok.Previous->isOneOf(TT_TemplateCloser, TT_TypeDeclarationParen) ||
1941         Tok.Previous->isSimpleTypeSpecifier() ||
1942         IsQualifiedPointerOrReference(Tok.Previous);
1943     bool ParensCouldEndDecl =
1944         Tok.Next->isOneOf(tok::equal, tok::semi, tok::l_brace, tok::greater);
1945     if (ParensAreType && !ParensCouldEndDecl)
1946       return true;
1947 
1948     // At this point, we heuristically assume that there are no casts at the
1949     // start of the line. We assume that we have found most cases where there
1950     // are by the logic above, e.g. "(void)x;".
1951     if (!LeftOfParens)
1952       return false;
1953 
1954     // Certain token types inside the parentheses mean that this can't be a
1955     // cast.
1956     for (const FormatToken *Token = Tok.MatchingParen->Next; Token != &Tok;
1957          Token = Token->Next)
1958       if (Token->is(TT_BinaryOperator))
1959         return false;
1960 
1961     // If the following token is an identifier or 'this', this is a cast. All
1962     // cases where this can be something else are handled above.
1963     if (Tok.Next->isOneOf(tok::identifier, tok::kw_this))
1964       return true;
1965 
1966     // Look for a cast `( x ) (`.
1967     if (Tok.Next->is(tok::l_paren) && Tok.Previous && Tok.Previous->Previous) {
1968       if (Tok.Previous->is(tok::identifier) &&
1969           Tok.Previous->Previous->is(tok::l_paren))
1970         return true;
1971     }
1972 
1973     if (!Tok.Next->Next)
1974       return false;
1975 
1976     // If the next token after the parenthesis is a unary operator, assume
1977     // that this is cast, unless there are unexpected tokens inside the
1978     // parenthesis.
1979     bool NextIsUnary =
1980         Tok.Next->isUnaryOperator() || Tok.Next->isOneOf(tok::amp, tok::star);
1981     if (!NextIsUnary || Tok.Next->is(tok::plus) ||
1982         !Tok.Next->Next->isOneOf(tok::identifier, tok::numeric_constant))
1983       return false;
1984     // Search for unexpected tokens.
1985     for (FormatToken *Prev = Tok.Previous; Prev != Tok.MatchingParen;
1986          Prev = Prev->Previous) {
1987       if (!Prev->isOneOf(tok::kw_const, tok::identifier, tok::coloncolon))
1988         return false;
1989     }
1990     return true;
1991   }
1992 
1993   /// Return the type of the given token assuming it is * or &.
1994   TokenType determineStarAmpUsage(const FormatToken &Tok, bool IsExpression,
1995                                   bool InTemplateArgument) {
1996     if (Style.Language == FormatStyle::LK_JavaScript)
1997       return TT_BinaryOperator;
1998 
1999     // && in C# must be a binary operator.
2000     if (Style.isCSharp() && Tok.is(tok::ampamp))
2001       return TT_BinaryOperator;
2002 
2003     const FormatToken *PrevToken = Tok.getPreviousNonComment();
2004     if (!PrevToken)
2005       return TT_UnaryOperator;
2006 
2007     const FormatToken *NextToken = Tok.getNextNonComment();
2008     if (!NextToken ||
2009         NextToken->isOneOf(tok::arrow, tok::equal, tok::kw_noexcept) ||
2010         NextToken->canBePointerOrReferenceQualifier() ||
2011         (NextToken->is(tok::l_brace) && !NextToken->getNextNonComment()))
2012       return TT_PointerOrReference;
2013 
2014     if (PrevToken->is(tok::coloncolon))
2015       return TT_PointerOrReference;
2016 
2017     if (PrevToken->is(tok::r_paren) && PrevToken->is(TT_TypeDeclarationParen))
2018       return TT_PointerOrReference;
2019 
2020     if (PrevToken->isOneOf(tok::l_paren, tok::l_square, tok::l_brace,
2021                            tok::comma, tok::semi, tok::kw_return, tok::colon,
2022                            tok::kw_co_return, tok::kw_co_await,
2023                            tok::kw_co_yield, tok::equal, tok::kw_delete,
2024                            tok::kw_sizeof, tok::kw_throw) ||
2025         PrevToken->isOneOf(TT_BinaryOperator, TT_ConditionalExpr,
2026                            TT_UnaryOperator, TT_CastRParen))
2027       return TT_UnaryOperator;
2028 
2029     if (NextToken->is(tok::l_square) && NextToken->isNot(TT_LambdaLSquare))
2030       return TT_PointerOrReference;
2031     if (NextToken->is(tok::kw_operator) && !IsExpression)
2032       return TT_PointerOrReference;
2033     if (NextToken->isOneOf(tok::comma, tok::semi))
2034       return TT_PointerOrReference;
2035 
2036     if (PrevToken->Tok.isLiteral() ||
2037         PrevToken->isOneOf(tok::r_paren, tok::r_square, tok::kw_true,
2038                            tok::kw_false, tok::r_brace) ||
2039         NextToken->Tok.isLiteral() ||
2040         NextToken->isOneOf(tok::kw_true, tok::kw_false) ||
2041         NextToken->isUnaryOperator() ||
2042         // If we know we're in a template argument, there are no named
2043         // declarations. Thus, having an identifier on the right-hand side
2044         // indicates a binary operator.
2045         (InTemplateArgument && NextToken->Tok.isAnyIdentifier()))
2046       return TT_BinaryOperator;
2047 
2048     // "&&(" is quite unlikely to be two successive unary "&".
2049     if (Tok.is(tok::ampamp) && NextToken->is(tok::l_paren))
2050       return TT_BinaryOperator;
2051 
2052     // This catches some cases where evaluation order is used as control flow:
2053     //   aaa && aaa->f();
2054     if (NextToken->Tok.isAnyIdentifier()) {
2055       const FormatToken *NextNextToken = NextToken->getNextNonComment();
2056       if (NextNextToken && NextNextToken->is(tok::arrow))
2057         return TT_BinaryOperator;
2058     }
2059 
2060     // It is very unlikely that we are going to find a pointer or reference type
2061     // definition on the RHS of an assignment.
2062     if (IsExpression && !Contexts.back().CaretFound)
2063       return TT_BinaryOperator;
2064 
2065     return TT_PointerOrReference;
2066   }
2067 
2068   TokenType determinePlusMinusCaretUsage(const FormatToken &Tok) {
2069     const FormatToken *PrevToken = Tok.getPreviousNonComment();
2070     if (!PrevToken)
2071       return TT_UnaryOperator;
2072 
2073     if (PrevToken->isOneOf(TT_CastRParen, TT_UnaryOperator))
2074       // This must be a sequence of leading unary operators.
2075       return TT_UnaryOperator;
2076 
2077     // Use heuristics to recognize unary operators.
2078     if (PrevToken->isOneOf(tok::equal, tok::l_paren, tok::comma, tok::l_square,
2079                            tok::question, tok::colon, tok::kw_return,
2080                            tok::kw_case, tok::at, tok::l_brace, tok::kw_throw,
2081                            tok::kw_co_return, tok::kw_co_yield))
2082       return TT_UnaryOperator;
2083 
2084     // There can't be two consecutive binary operators.
2085     if (PrevToken->is(TT_BinaryOperator))
2086       return TT_UnaryOperator;
2087 
2088     // Fall back to marking the token as binary operator.
2089     return TT_BinaryOperator;
2090   }
2091 
2092   /// Determine whether ++/-- are pre- or post-increments/-decrements.
2093   TokenType determineIncrementUsage(const FormatToken &Tok) {
2094     const FormatToken *PrevToken = Tok.getPreviousNonComment();
2095     if (!PrevToken || PrevToken->is(TT_CastRParen))
2096       return TT_UnaryOperator;
2097     if (PrevToken->isOneOf(tok::r_paren, tok::r_square, tok::identifier))
2098       return TT_TrailingUnaryOperator;
2099 
2100     return TT_UnaryOperator;
2101   }
2102 
2103   SmallVector<Context, 8> Contexts;
2104 
2105   const FormatStyle &Style;
2106   AnnotatedLine &Line;
2107   FormatToken *CurrentToken;
2108   bool AutoFound;
2109   const AdditionalKeywords &Keywords;
2110 
2111   // Set of "<" tokens that do not open a template parameter list. If parseAngle
2112   // determines that a specific token can't be a template opener, it will make
2113   // same decision irrespective of the decisions for tokens leading up to it.
2114   // Store this information to prevent this from causing exponential runtime.
2115   llvm::SmallPtrSet<FormatToken *, 16> NonTemplateLess;
2116 };
2117 
2118 static const int PrecedenceUnaryOperator = prec::PointerToMember + 1;
2119 static const int PrecedenceArrowAndPeriod = prec::PointerToMember + 2;
2120 
2121 /// Parses binary expressions by inserting fake parenthesis based on
2122 /// operator precedence.
2123 class ExpressionParser {
2124 public:
2125   ExpressionParser(const FormatStyle &Style, const AdditionalKeywords &Keywords,
2126                    AnnotatedLine &Line)
2127       : Style(Style), Keywords(Keywords), Current(Line.First) {}
2128 
2129   /// Parse expressions with the given operator precedence.
2130   void parse(int Precedence = 0) {
2131     // Skip 'return' and ObjC selector colons as they are not part of a binary
2132     // expression.
2133     while (Current && (Current->is(tok::kw_return) ||
2134                        (Current->is(tok::colon) &&
2135                         Current->isOneOf(TT_ObjCMethodExpr, TT_DictLiteral))))
2136       next();
2137 
2138     if (!Current || Precedence > PrecedenceArrowAndPeriod)
2139       return;
2140 
2141     // Conditional expressions need to be parsed separately for proper nesting.
2142     if (Precedence == prec::Conditional) {
2143       parseConditionalExpr();
2144       return;
2145     }
2146 
2147     // Parse unary operators, which all have a higher precedence than binary
2148     // operators.
2149     if (Precedence == PrecedenceUnaryOperator) {
2150       parseUnaryOperator();
2151       return;
2152     }
2153 
2154     FormatToken *Start = Current;
2155     FormatToken *LatestOperator = nullptr;
2156     unsigned OperatorIndex = 0;
2157 
2158     while (Current) {
2159       // Consume operators with higher precedence.
2160       parse(Precedence + 1);
2161 
2162       int CurrentPrecedence = getCurrentPrecedence();
2163 
2164       if (Current && Current->is(TT_SelectorName) &&
2165           Precedence == CurrentPrecedence) {
2166         if (LatestOperator)
2167           addFakeParenthesis(Start, prec::Level(Precedence));
2168         Start = Current;
2169       }
2170 
2171       // At the end of the line or when an operator with higher precedence is
2172       // found, insert fake parenthesis and return.
2173       if (!Current ||
2174           (Current->closesScope() &&
2175            (Current->MatchingParen || Current->is(TT_TemplateString))) ||
2176           (CurrentPrecedence != -1 && CurrentPrecedence < Precedence) ||
2177           (CurrentPrecedence == prec::Conditional &&
2178            Precedence == prec::Assignment && Current->is(tok::colon))) {
2179         break;
2180       }
2181 
2182       // Consume scopes: (), [], <> and {}
2183       if (Current->opensScope()) {
2184         // In fragment of a JavaScript template string can look like '}..${' and
2185         // thus close a scope and open a new one at the same time.
2186         while (Current && (!Current->closesScope() || Current->opensScope())) {
2187           next();
2188           parse();
2189         }
2190         next();
2191       } else {
2192         // Operator found.
2193         if (CurrentPrecedence == Precedence) {
2194           if (LatestOperator)
2195             LatestOperator->NextOperator = Current;
2196           LatestOperator = Current;
2197           Current->OperatorIndex = OperatorIndex;
2198           ++OperatorIndex;
2199         }
2200         next(/*SkipPastLeadingComments=*/Precedence > 0);
2201       }
2202     }
2203 
2204     if (LatestOperator && (Current || Precedence > 0)) {
2205       // LatestOperator->LastOperator = true;
2206       if (Precedence == PrecedenceArrowAndPeriod) {
2207         // Call expressions don't have a binary operator precedence.
2208         addFakeParenthesis(Start, prec::Unknown);
2209       } else {
2210         addFakeParenthesis(Start, prec::Level(Precedence));
2211       }
2212     }
2213   }
2214 
2215 private:
2216   /// Gets the precedence (+1) of the given token for binary operators
2217   /// and other tokens that we treat like binary operators.
2218   int getCurrentPrecedence() {
2219     if (Current) {
2220       const FormatToken *NextNonComment = Current->getNextNonComment();
2221       if (Current->is(TT_ConditionalExpr))
2222         return prec::Conditional;
2223       if (NextNonComment && Current->is(TT_SelectorName) &&
2224           (NextNonComment->isOneOf(TT_DictLiteral, TT_JsTypeColon) ||
2225            ((Style.Language == FormatStyle::LK_Proto ||
2226              Style.Language == FormatStyle::LK_TextProto) &&
2227             NextNonComment->is(tok::less))))
2228         return prec::Assignment;
2229       if (Current->is(TT_JsComputedPropertyName))
2230         return prec::Assignment;
2231       if (Current->is(TT_LambdaArrow))
2232         return prec::Comma;
2233       if (Current->is(TT_FatArrow))
2234         return prec::Assignment;
2235       if (Current->isOneOf(tok::semi, TT_InlineASMColon, TT_SelectorName) ||
2236           (Current->is(tok::comment) && NextNonComment &&
2237            NextNonComment->is(TT_SelectorName)))
2238         return 0;
2239       if (Current->is(TT_RangeBasedForLoopColon))
2240         return prec::Comma;
2241       if ((Style.Language == FormatStyle::LK_Java ||
2242            Style.Language == FormatStyle::LK_JavaScript) &&
2243           Current->is(Keywords.kw_instanceof))
2244         return prec::Relational;
2245       if (Style.Language == FormatStyle::LK_JavaScript &&
2246           Current->isOneOf(Keywords.kw_in, Keywords.kw_as))
2247         return prec::Relational;
2248       if (Current->is(TT_BinaryOperator) || Current->is(tok::comma))
2249         return Current->getPrecedence();
2250       if (Current->isOneOf(tok::period, tok::arrow))
2251         return PrecedenceArrowAndPeriod;
2252       if ((Style.Language == FormatStyle::LK_Java ||
2253            Style.Language == FormatStyle::LK_JavaScript) &&
2254           Current->isOneOf(Keywords.kw_extends, Keywords.kw_implements,
2255                            Keywords.kw_throws))
2256         return 0;
2257     }
2258     return -1;
2259   }
2260 
2261   void addFakeParenthesis(FormatToken *Start, prec::Level Precedence) {
2262     Start->FakeLParens.push_back(Precedence);
2263     if (Precedence > prec::Unknown)
2264       Start->StartsBinaryExpression = true;
2265     if (Current) {
2266       FormatToken *Previous = Current->Previous;
2267       while (Previous->is(tok::comment) && Previous->Previous)
2268         Previous = Previous->Previous;
2269       ++Previous->FakeRParens;
2270       if (Precedence > prec::Unknown)
2271         Previous->EndsBinaryExpression = true;
2272     }
2273   }
2274 
2275   /// Parse unary operator expressions and surround them with fake
2276   /// parentheses if appropriate.
2277   void parseUnaryOperator() {
2278     llvm::SmallVector<FormatToken *, 2> Tokens;
2279     while (Current && Current->is(TT_UnaryOperator)) {
2280       Tokens.push_back(Current);
2281       next();
2282     }
2283     parse(PrecedenceArrowAndPeriod);
2284     for (FormatToken *Token : llvm::reverse(Tokens))
2285       // The actual precedence doesn't matter.
2286       addFakeParenthesis(Token, prec::Unknown);
2287   }
2288 
2289   void parseConditionalExpr() {
2290     while (Current && Current->isTrailingComment()) {
2291       next();
2292     }
2293     FormatToken *Start = Current;
2294     parse(prec::LogicalOr);
2295     if (!Current || !Current->is(tok::question))
2296       return;
2297     next();
2298     parse(prec::Assignment);
2299     if (!Current || Current->isNot(TT_ConditionalExpr))
2300       return;
2301     next();
2302     parse(prec::Assignment);
2303     addFakeParenthesis(Start, prec::Conditional);
2304   }
2305 
2306   void next(bool SkipPastLeadingComments = true) {
2307     if (Current)
2308       Current = Current->Next;
2309     while (Current &&
2310            (Current->NewlinesBefore == 0 || SkipPastLeadingComments) &&
2311            Current->isTrailingComment())
2312       Current = Current->Next;
2313   }
2314 
2315   const FormatStyle &Style;
2316   const AdditionalKeywords &Keywords;
2317   FormatToken *Current;
2318 };
2319 
2320 } // end anonymous namespace
2321 
2322 void TokenAnnotator::setCommentLineLevels(
2323     SmallVectorImpl<AnnotatedLine *> &Lines) {
2324   const AnnotatedLine *NextNonCommentLine = nullptr;
2325   for (SmallVectorImpl<AnnotatedLine *>::reverse_iterator I = Lines.rbegin(),
2326                                                           E = Lines.rend();
2327        I != E; ++I) {
2328     bool CommentLine = true;
2329     for (const FormatToken *Tok = (*I)->First; Tok; Tok = Tok->Next) {
2330       if (!Tok->is(tok::comment)) {
2331         CommentLine = false;
2332         break;
2333       }
2334     }
2335 
2336     // If the comment is currently aligned with the line immediately following
2337     // it, that's probably intentional and we should keep it.
2338     if (NextNonCommentLine && CommentLine &&
2339         NextNonCommentLine->First->NewlinesBefore <= 1 &&
2340         NextNonCommentLine->First->OriginalColumn ==
2341             (*I)->First->OriginalColumn) {
2342       // Align comments for preprocessor lines with the # in column 0 if
2343       // preprocessor lines are not indented. Otherwise, align with the next
2344       // line.
2345       (*I)->Level =
2346           (Style.IndentPPDirectives != FormatStyle::PPDIS_BeforeHash &&
2347            (NextNonCommentLine->Type == LT_PreprocessorDirective ||
2348             NextNonCommentLine->Type == LT_ImportStatement))
2349               ? 0
2350               : NextNonCommentLine->Level;
2351     } else {
2352       NextNonCommentLine = (*I)->First->isNot(tok::r_brace) ? (*I) : nullptr;
2353     }
2354 
2355     setCommentLineLevels((*I)->Children);
2356   }
2357 }
2358 
2359 static unsigned maxNestingDepth(const AnnotatedLine &Line) {
2360   unsigned Result = 0;
2361   for (const auto *Tok = Line.First; Tok != nullptr; Tok = Tok->Next)
2362     Result = std::max(Result, Tok->NestingLevel);
2363   return Result;
2364 }
2365 
2366 void TokenAnnotator::annotate(AnnotatedLine &Line) {
2367   for (SmallVectorImpl<AnnotatedLine *>::iterator I = Line.Children.begin(),
2368                                                   E = Line.Children.end();
2369        I != E; ++I) {
2370     annotate(**I);
2371   }
2372   AnnotatingParser Parser(Style, Line, Keywords);
2373   Line.Type = Parser.parseLine();
2374 
2375   // With very deep nesting, ExpressionParser uses lots of stack and the
2376   // formatting algorithm is very slow. We're not going to do a good job here
2377   // anyway - it's probably generated code being formatted by mistake.
2378   // Just skip the whole line.
2379   if (maxNestingDepth(Line) > 50)
2380     Line.Type = LT_Invalid;
2381 
2382   if (Line.Type == LT_Invalid)
2383     return;
2384 
2385   ExpressionParser ExprParser(Style, Keywords, Line);
2386   ExprParser.parse();
2387 
2388   if (Line.startsWith(TT_ObjCMethodSpecifier))
2389     Line.Type = LT_ObjCMethodDecl;
2390   else if (Line.startsWith(TT_ObjCDecl))
2391     Line.Type = LT_ObjCDecl;
2392   else if (Line.startsWith(TT_ObjCProperty))
2393     Line.Type = LT_ObjCProperty;
2394 
2395   Line.First->SpacesRequiredBefore = 1;
2396   Line.First->CanBreakBefore = Line.First->MustBreakBefore;
2397 }
2398 
2399 // This function heuristically determines whether 'Current' starts the name of a
2400 // function declaration.
2401 static bool isFunctionDeclarationName(const FormatToken &Current,
2402                                       const AnnotatedLine &Line) {
2403   auto skipOperatorName = [](const FormatToken *Next) -> const FormatToken * {
2404     for (; Next; Next = Next->Next) {
2405       if (Next->is(TT_OverloadedOperatorLParen))
2406         return Next;
2407       if (Next->is(TT_OverloadedOperator))
2408         continue;
2409       if (Next->isOneOf(tok::kw_new, tok::kw_delete)) {
2410         // For 'new[]' and 'delete[]'.
2411         if (Next->Next &&
2412             Next->Next->startsSequence(tok::l_square, tok::r_square))
2413           Next = Next->Next->Next;
2414         continue;
2415       }
2416       if (Next->startsSequence(tok::l_square, tok::r_square)) {
2417         // For operator[]().
2418         Next = Next->Next;
2419         continue;
2420       }
2421       if ((Next->isSimpleTypeSpecifier() || Next->is(tok::identifier)) &&
2422           Next->Next && Next->Next->isOneOf(tok::star, tok::amp, tok::ampamp)) {
2423         // For operator void*(), operator char*(), operator Foo*().
2424         Next = Next->Next;
2425         continue;
2426       }
2427       if (Next->is(TT_TemplateOpener) && Next->MatchingParen) {
2428         Next = Next->MatchingParen;
2429         continue;
2430       }
2431 
2432       break;
2433     }
2434     return nullptr;
2435   };
2436 
2437   // Find parentheses of parameter list.
2438   const FormatToken *Next = Current.Next;
2439   if (Current.is(tok::kw_operator)) {
2440     if (Current.Previous && Current.Previous->is(tok::coloncolon))
2441       return false;
2442     Next = skipOperatorName(Next);
2443   } else {
2444     if (!Current.is(TT_StartOfName) || Current.NestingLevel != 0)
2445       return false;
2446     for (; Next; Next = Next->Next) {
2447       if (Next->is(TT_TemplateOpener)) {
2448         Next = Next->MatchingParen;
2449       } else if (Next->is(tok::coloncolon)) {
2450         Next = Next->Next;
2451         if (!Next)
2452           return false;
2453         if (Next->is(tok::kw_operator)) {
2454           Next = skipOperatorName(Next->Next);
2455           break;
2456         }
2457         if (!Next->is(tok::identifier))
2458           return false;
2459       } else if (Next->is(tok::l_paren)) {
2460         break;
2461       } else {
2462         return false;
2463       }
2464     }
2465   }
2466 
2467   // Check whether parameter list can belong to a function declaration.
2468   if (!Next || !Next->is(tok::l_paren) || !Next->MatchingParen)
2469     return false;
2470   // If the lines ends with "{", this is likely an function definition.
2471   if (Line.Last->is(tok::l_brace))
2472     return true;
2473   if (Next->Next == Next->MatchingParen)
2474     return true; // Empty parentheses.
2475   // If there is an &/&& after the r_paren, this is likely a function.
2476   if (Next->MatchingParen->Next &&
2477       Next->MatchingParen->Next->is(TT_PointerOrReference))
2478     return true;
2479   for (const FormatToken *Tok = Next->Next; Tok && Tok != Next->MatchingParen;
2480        Tok = Tok->Next) {
2481     if (Tok->is(TT_TypeDeclarationParen))
2482       return true;
2483     if (Tok->isOneOf(tok::l_paren, TT_TemplateOpener) && Tok->MatchingParen) {
2484       Tok = Tok->MatchingParen;
2485       continue;
2486     }
2487     if (Tok->is(tok::kw_const) || Tok->isSimpleTypeSpecifier() ||
2488         Tok->isOneOf(TT_PointerOrReference, TT_StartOfName, tok::ellipsis))
2489       return true;
2490     if (Tok->isOneOf(tok::l_brace, tok::string_literal, TT_ObjCMethodExpr) ||
2491         Tok->Tok.isLiteral())
2492       return false;
2493   }
2494   return false;
2495 }
2496 
2497 bool TokenAnnotator::mustBreakForReturnType(const AnnotatedLine &Line) const {
2498   assert(Line.MightBeFunctionDecl);
2499 
2500   if ((Style.AlwaysBreakAfterReturnType == FormatStyle::RTBS_TopLevel ||
2501        Style.AlwaysBreakAfterReturnType ==
2502            FormatStyle::RTBS_TopLevelDefinitions) &&
2503       Line.Level > 0)
2504     return false;
2505 
2506   switch (Style.AlwaysBreakAfterReturnType) {
2507   case FormatStyle::RTBS_None:
2508     return false;
2509   case FormatStyle::RTBS_All:
2510   case FormatStyle::RTBS_TopLevel:
2511     return true;
2512   case FormatStyle::RTBS_AllDefinitions:
2513   case FormatStyle::RTBS_TopLevelDefinitions:
2514     return Line.mightBeFunctionDefinition();
2515   }
2516 
2517   return false;
2518 }
2519 
2520 void TokenAnnotator::calculateFormattingInformation(AnnotatedLine &Line) {
2521   for (SmallVectorImpl<AnnotatedLine *>::iterator I = Line.Children.begin(),
2522                                                   E = Line.Children.end();
2523        I != E; ++I) {
2524     calculateFormattingInformation(**I);
2525   }
2526 
2527   Line.First->TotalLength =
2528       Line.First->IsMultiline ? Style.ColumnLimit
2529                               : Line.FirstStartColumn + Line.First->ColumnWidth;
2530   FormatToken *Current = Line.First->Next;
2531   bool InFunctionDecl = Line.MightBeFunctionDecl;
2532   bool AlignArrayOfStructures =
2533       (Style.AlignArrayOfStructures != FormatStyle::AIAS_None &&
2534        Line.Type == LT_ArrayOfStructInitializer);
2535   if (AlignArrayOfStructures)
2536     calculateArrayInitializerColumnList(Line);
2537 
2538   while (Current) {
2539     if (isFunctionDeclarationName(*Current, Line))
2540       Current->setType(TT_FunctionDeclarationName);
2541     if (Current->is(TT_LineComment)) {
2542       if (Current->Previous->is(BK_BracedInit) &&
2543           Current->Previous->opensScope())
2544         Current->SpacesRequiredBefore =
2545             (Style.Cpp11BracedListStyle && !Style.SpacesInParentheses) ? 0 : 1;
2546       else
2547         Current->SpacesRequiredBefore = Style.SpacesBeforeTrailingComments;
2548 
2549       // If we find a trailing comment, iterate backwards to determine whether
2550       // it seems to relate to a specific parameter. If so, break before that
2551       // parameter to avoid changing the comment's meaning. E.g. don't move 'b'
2552       // to the previous line in:
2553       //   SomeFunction(a,
2554       //                b, // comment
2555       //                c);
2556       if (!Current->HasUnescapedNewline) {
2557         for (FormatToken *Parameter = Current->Previous; Parameter;
2558              Parameter = Parameter->Previous) {
2559           if (Parameter->isOneOf(tok::comment, tok::r_brace))
2560             break;
2561           if (Parameter->Previous && Parameter->Previous->is(tok::comma)) {
2562             if (!Parameter->Previous->is(TT_CtorInitializerComma) &&
2563                 Parameter->HasUnescapedNewline)
2564               Parameter->MustBreakBefore = true;
2565             break;
2566           }
2567         }
2568       }
2569     } else if (Current->SpacesRequiredBefore == 0 &&
2570                spaceRequiredBefore(Line, *Current)) {
2571       Current->SpacesRequiredBefore = 1;
2572     }
2573 
2574     Current->MustBreakBefore =
2575         Current->MustBreakBefore || mustBreakBefore(Line, *Current);
2576 
2577     if (!Current->MustBreakBefore && InFunctionDecl &&
2578         Current->is(TT_FunctionDeclarationName))
2579       Current->MustBreakBefore = mustBreakForReturnType(Line);
2580 
2581     Current->CanBreakBefore =
2582         Current->MustBreakBefore || canBreakBefore(Line, *Current);
2583     unsigned ChildSize = 0;
2584     if (Current->Previous->Children.size() == 1) {
2585       FormatToken &LastOfChild = *Current->Previous->Children[0]->Last;
2586       ChildSize = LastOfChild.isTrailingComment() ? Style.ColumnLimit
2587                                                   : LastOfChild.TotalLength + 1;
2588     }
2589     const FormatToken *Prev = Current->Previous;
2590     if (Current->MustBreakBefore || Prev->Children.size() > 1 ||
2591         (Prev->Children.size() == 1 &&
2592          Prev->Children[0]->First->MustBreakBefore) ||
2593         Current->IsMultiline)
2594       Current->TotalLength = Prev->TotalLength + Style.ColumnLimit;
2595     else
2596       Current->TotalLength = Prev->TotalLength + Current->ColumnWidth +
2597                              ChildSize + Current->SpacesRequiredBefore;
2598 
2599     if (Current->is(TT_CtorInitializerColon))
2600       InFunctionDecl = false;
2601 
2602     // FIXME: Only calculate this if CanBreakBefore is true once static
2603     // initializers etc. are sorted out.
2604     // FIXME: Move magic numbers to a better place.
2605 
2606     // Reduce penalty for aligning ObjC method arguments using the colon
2607     // alignment as this is the canonical way (still prefer fitting everything
2608     // into one line if possible). Trying to fit a whole expression into one
2609     // line should not force other line breaks (e.g. when ObjC method
2610     // expression is a part of other expression).
2611     Current->SplitPenalty = splitPenalty(Line, *Current, InFunctionDecl);
2612     if (Style.Language == FormatStyle::LK_ObjC &&
2613         Current->is(TT_SelectorName) && Current->ParameterIndex > 0) {
2614       if (Current->ParameterIndex == 1)
2615         Current->SplitPenalty += 5 * Current->BindingStrength;
2616     } else {
2617       Current->SplitPenalty += 20 * Current->BindingStrength;
2618     }
2619 
2620     Current = Current->Next;
2621   }
2622 
2623   calculateUnbreakableTailLengths(Line);
2624   unsigned IndentLevel = Line.Level;
2625   for (Current = Line.First; Current != nullptr; Current = Current->Next) {
2626     if (Current->Role)
2627       Current->Role->precomputeFormattingInfos(Current);
2628     if (Current->MatchingParen &&
2629         Current->MatchingParen->opensBlockOrBlockTypeList(Style)) {
2630       assert(IndentLevel > 0);
2631       --IndentLevel;
2632     }
2633     Current->IndentLevel = IndentLevel;
2634     if (Current->opensBlockOrBlockTypeList(Style))
2635       ++IndentLevel;
2636   }
2637 
2638   LLVM_DEBUG({ printDebugInfo(Line); });
2639 }
2640 
2641 void TokenAnnotator::calculateUnbreakableTailLengths(AnnotatedLine &Line) {
2642   unsigned UnbreakableTailLength = 0;
2643   FormatToken *Current = Line.Last;
2644   while (Current) {
2645     Current->UnbreakableTailLength = UnbreakableTailLength;
2646     if (Current->CanBreakBefore ||
2647         Current->isOneOf(tok::comment, tok::string_literal)) {
2648       UnbreakableTailLength = 0;
2649     } else {
2650       UnbreakableTailLength +=
2651           Current->ColumnWidth + Current->SpacesRequiredBefore;
2652     }
2653     Current = Current->Previous;
2654   }
2655 }
2656 
2657 void TokenAnnotator::calculateArrayInitializerColumnList(AnnotatedLine &Line) {
2658   if (Line.First == Line.Last) {
2659     return;
2660   }
2661   auto *CurrentToken = Line.First;
2662   CurrentToken->ArrayInitializerLineStart = true;
2663   unsigned Depth = 0;
2664   while (CurrentToken != nullptr && CurrentToken != Line.Last) {
2665     if (CurrentToken->is(tok::l_brace)) {
2666       CurrentToken->IsArrayInitializer = true;
2667       if (CurrentToken->Next != nullptr)
2668         CurrentToken->Next->MustBreakBefore = true;
2669       CurrentToken =
2670           calculateInitializerColumnList(Line, CurrentToken->Next, Depth + 1);
2671     } else {
2672       CurrentToken = CurrentToken->Next;
2673     }
2674   }
2675 }
2676 
2677 FormatToken *TokenAnnotator::calculateInitializerColumnList(
2678     AnnotatedLine &Line, FormatToken *CurrentToken, unsigned Depth) {
2679   while (CurrentToken != nullptr && CurrentToken != Line.Last) {
2680     if (CurrentToken->is(tok::l_brace))
2681       ++Depth;
2682     else if (CurrentToken->is(tok::r_brace))
2683       --Depth;
2684     if (Depth == 2 && CurrentToken->isOneOf(tok::l_brace, tok::comma)) {
2685       CurrentToken = CurrentToken->Next;
2686       if (CurrentToken == nullptr)
2687         break;
2688       CurrentToken->StartsColumn = true;
2689       CurrentToken = CurrentToken->Previous;
2690     }
2691     CurrentToken = CurrentToken->Next;
2692   }
2693   return CurrentToken;
2694 }
2695 
2696 unsigned TokenAnnotator::splitPenalty(const AnnotatedLine &Line,
2697                                       const FormatToken &Tok,
2698                                       bool InFunctionDecl) {
2699   const FormatToken &Left = *Tok.Previous;
2700   const FormatToken &Right = Tok;
2701 
2702   if (Left.is(tok::semi))
2703     return 0;
2704 
2705   if (Style.Language == FormatStyle::LK_Java) {
2706     if (Right.isOneOf(Keywords.kw_extends, Keywords.kw_throws))
2707       return 1;
2708     if (Right.is(Keywords.kw_implements))
2709       return 2;
2710     if (Left.is(tok::comma) && Left.NestingLevel == 0)
2711       return 3;
2712   } else if (Style.Language == FormatStyle::LK_JavaScript) {
2713     if (Right.is(Keywords.kw_function) && Left.isNot(tok::comma))
2714       return 100;
2715     if (Left.is(TT_JsTypeColon))
2716       return 35;
2717     if ((Left.is(TT_TemplateString) && Left.TokenText.endswith("${")) ||
2718         (Right.is(TT_TemplateString) && Right.TokenText.startswith("}")))
2719       return 100;
2720     // Prefer breaking call chains (".foo") over empty "{}", "[]" or "()".
2721     if (Left.opensScope() && Right.closesScope())
2722       return 200;
2723   }
2724 
2725   if (Right.is(tok::identifier) && Right.Next && Right.Next->is(TT_DictLiteral))
2726     return 1;
2727   if (Right.is(tok::l_square)) {
2728     if (Style.Language == FormatStyle::LK_Proto)
2729       return 1;
2730     if (Left.is(tok::r_square))
2731       return 200;
2732     // Slightly prefer formatting local lambda definitions like functions.
2733     if (Right.is(TT_LambdaLSquare) && Left.is(tok::equal))
2734       return 35;
2735     if (!Right.isOneOf(TT_ObjCMethodExpr, TT_LambdaLSquare,
2736                        TT_ArrayInitializerLSquare,
2737                        TT_DesignatedInitializerLSquare, TT_AttributeSquare))
2738       return 500;
2739   }
2740 
2741   if (Left.is(tok::coloncolon) ||
2742       (Right.is(tok::period) && Style.Language == FormatStyle::LK_Proto))
2743     return 500;
2744   if (Right.isOneOf(TT_StartOfName, TT_FunctionDeclarationName) ||
2745       Right.is(tok::kw_operator)) {
2746     if (Line.startsWith(tok::kw_for) && Right.PartOfMultiVariableDeclStmt)
2747       return 3;
2748     if (Left.is(TT_StartOfName))
2749       return 110;
2750     if (InFunctionDecl && Right.NestingLevel == 0)
2751       return Style.PenaltyReturnTypeOnItsOwnLine;
2752     return 200;
2753   }
2754   if (Right.is(TT_PointerOrReference))
2755     return 190;
2756   if (Right.is(TT_LambdaArrow))
2757     return 110;
2758   if (Left.is(tok::equal) && Right.is(tok::l_brace))
2759     return 160;
2760   if (Left.is(TT_CastRParen))
2761     return 100;
2762   if (Left.isOneOf(tok::kw_class, tok::kw_struct))
2763     return 5000;
2764   if (Left.is(tok::comment))
2765     return 1000;
2766 
2767   if (Left.isOneOf(TT_RangeBasedForLoopColon, TT_InheritanceColon,
2768                    TT_CtorInitializerColon))
2769     return 2;
2770 
2771   if (Right.isMemberAccess()) {
2772     // Breaking before the "./->" of a chained call/member access is reasonably
2773     // cheap, as formatting those with one call per line is generally
2774     // desirable. In particular, it should be cheaper to break before the call
2775     // than it is to break inside a call's parameters, which could lead to weird
2776     // "hanging" indents. The exception is the very last "./->" to support this
2777     // frequent pattern:
2778     //
2779     //   aaaaaaaa.aaaaaaaa.bbbbbbb().ccccccccccccccccccccc(
2780     //       dddddddd);
2781     //
2782     // which might otherwise be blown up onto many lines. Here, clang-format
2783     // won't produce "hanging" indents anyway as there is no other trailing
2784     // call.
2785     //
2786     // Also apply higher penalty is not a call as that might lead to a wrapping
2787     // like:
2788     //
2789     //   aaaaaaa
2790     //       .aaaaaaaaa.bbbbbbbb(cccccccc);
2791     return !Right.NextOperator || !Right.NextOperator->Previous->closesScope()
2792                ? 150
2793                : 35;
2794   }
2795 
2796   if (Right.is(TT_TrailingAnnotation) &&
2797       (!Right.Next || Right.Next->isNot(tok::l_paren))) {
2798     // Moving trailing annotations to the next line is fine for ObjC method
2799     // declarations.
2800     if (Line.startsWith(TT_ObjCMethodSpecifier))
2801       return 10;
2802     // Generally, breaking before a trailing annotation is bad unless it is
2803     // function-like. It seems to be especially preferable to keep standard
2804     // annotations (i.e. "const", "final" and "override") on the same line.
2805     // Use a slightly higher penalty after ")" so that annotations like
2806     // "const override" are kept together.
2807     bool is_short_annotation = Right.TokenText.size() < 10;
2808     return (Left.is(tok::r_paren) ? 100 : 120) + (is_short_annotation ? 50 : 0);
2809   }
2810 
2811   // In for-loops, prefer breaking at ',' and ';'.
2812   if (Line.startsWith(tok::kw_for) && Left.is(tok::equal))
2813     return 4;
2814 
2815   // In Objective-C method expressions, prefer breaking before "param:" over
2816   // breaking after it.
2817   if (Right.is(TT_SelectorName))
2818     return 0;
2819   if (Left.is(tok::colon) && Left.is(TT_ObjCMethodExpr))
2820     return Line.MightBeFunctionDecl ? 50 : 500;
2821 
2822   // In Objective-C type declarations, avoid breaking after the category's
2823   // open paren (we'll prefer breaking after the protocol list's opening
2824   // angle bracket, if present).
2825   if (Line.Type == LT_ObjCDecl && Left.is(tok::l_paren) && Left.Previous &&
2826       Left.Previous->isOneOf(tok::identifier, tok::greater))
2827     return 500;
2828 
2829   if (Left.is(tok::l_paren) && InFunctionDecl &&
2830       Style.AlignAfterOpenBracket != FormatStyle::BAS_DontAlign)
2831     return 100;
2832   if (Left.is(tok::l_paren) && Left.Previous &&
2833       (Left.Previous->is(tok::kw_for) || Left.Previous->isIf()))
2834     return 1000;
2835   if (Left.is(tok::equal) && InFunctionDecl)
2836     return 110;
2837   if (Right.is(tok::r_brace))
2838     return 1;
2839   if (Left.is(TT_TemplateOpener))
2840     return 100;
2841   if (Left.opensScope()) {
2842     // If we aren't aligning after opening parens/braces we can always break
2843     // here unless the style does not want us to place all arguments on the
2844     // next line.
2845     if (Style.AlignAfterOpenBracket == FormatStyle::BAS_DontAlign &&
2846         (Left.ParameterCount <= 1 || Style.AllowAllArgumentsOnNextLine))
2847       return 0;
2848     if (Left.is(tok::l_brace) && !Style.Cpp11BracedListStyle)
2849       return 19;
2850     return Left.ParameterCount > 1 ? Style.PenaltyBreakBeforeFirstCallParameter
2851                                    : 19;
2852   }
2853   if (Left.is(TT_JavaAnnotation))
2854     return 50;
2855 
2856   if (Left.is(TT_UnaryOperator))
2857     return 60;
2858   if (Left.isOneOf(tok::plus, tok::comma) && Left.Previous &&
2859       Left.Previous->isLabelString() &&
2860       (Left.NextOperator || Left.OperatorIndex != 0))
2861     return 50;
2862   if (Right.is(tok::plus) && Left.isLabelString() &&
2863       (Right.NextOperator || Right.OperatorIndex != 0))
2864     return 25;
2865   if (Left.is(tok::comma))
2866     return 1;
2867   if (Right.is(tok::lessless) && Left.isLabelString() &&
2868       (Right.NextOperator || Right.OperatorIndex != 1))
2869     return 25;
2870   if (Right.is(tok::lessless)) {
2871     // Breaking at a << is really cheap.
2872     if (!Left.is(tok::r_paren) || Right.OperatorIndex > 0)
2873       // Slightly prefer to break before the first one in log-like statements.
2874       return 2;
2875     return 1;
2876   }
2877   if (Left.ClosesTemplateDeclaration)
2878     return Style.PenaltyBreakTemplateDeclaration;
2879   if (Left.is(TT_ConditionalExpr))
2880     return prec::Conditional;
2881   prec::Level Level = Left.getPrecedence();
2882   if (Level == prec::Unknown)
2883     Level = Right.getPrecedence();
2884   if (Level == prec::Assignment)
2885     return Style.PenaltyBreakAssignment;
2886   if (Level != prec::Unknown)
2887     return Level;
2888 
2889   return 3;
2890 }
2891 
2892 bool TokenAnnotator::spaceRequiredBeforeParens(const FormatToken &Right) const {
2893   return Style.SpaceBeforeParens == FormatStyle::SBPO_Always ||
2894          (Style.SpaceBeforeParens == FormatStyle::SBPO_NonEmptyParentheses &&
2895           Right.ParameterCount > 0);
2896 }
2897 
2898 bool TokenAnnotator::spaceRequiredBetween(const AnnotatedLine &Line,
2899                                           const FormatToken &Left,
2900                                           const FormatToken &Right) {
2901   if (Left.is(tok::kw_return) && Right.isNot(tok::semi))
2902     return true;
2903   if (Left.is(Keywords.kw_assert) && Style.Language == FormatStyle::LK_Java)
2904     return true;
2905   if (Style.ObjCSpaceAfterProperty && Line.Type == LT_ObjCProperty &&
2906       Left.Tok.getObjCKeywordID() == tok::objc_property)
2907     return true;
2908   if (Right.is(tok::hashhash))
2909     return Left.is(tok::hash);
2910   if (Left.isOneOf(tok::hashhash, tok::hash))
2911     return Right.is(tok::hash);
2912   if ((Left.is(tok::l_paren) && Right.is(tok::r_paren)) ||
2913       (Left.is(tok::l_brace) && Left.isNot(BK_Block) &&
2914        Right.is(tok::r_brace) && Right.isNot(BK_Block)))
2915     return Style.SpaceInEmptyParentheses;
2916   if (Style.SpacesInConditionalStatement) {
2917     if (Left.is(tok::l_paren) && Left.Previous &&
2918         isKeywordWithCondition(*Left.Previous))
2919       return true;
2920     if (Right.is(tok::r_paren) && Right.MatchingParen &&
2921         Right.MatchingParen->Previous &&
2922         isKeywordWithCondition(*Right.MatchingParen->Previous))
2923       return true;
2924   }
2925 
2926   // requires ( or requires(
2927   if (Right.is(tok::l_paren) && Left.is(tok::kw_requires))
2928     return spaceRequiredBeforeParens(Right);
2929   // requires clause Concept1<T> && Concept2<T>
2930   if (Left.is(TT_ConstraintJunctions) && Right.is(tok::identifier))
2931     return true;
2932 
2933   if (Left.is(tok::l_paren) || Right.is(tok::r_paren))
2934     return (Right.is(TT_CastRParen) ||
2935             (Left.MatchingParen && Left.MatchingParen->is(TT_CastRParen)))
2936                ? Style.SpacesInCStyleCastParentheses
2937                : Style.SpacesInParentheses;
2938   if (Right.isOneOf(tok::semi, tok::comma))
2939     return false;
2940   if (Right.is(tok::less) && Line.Type == LT_ObjCDecl) {
2941     bool IsLightweightGeneric = Right.MatchingParen &&
2942                                 Right.MatchingParen->Next &&
2943                                 Right.MatchingParen->Next->is(tok::colon);
2944     return !IsLightweightGeneric && Style.ObjCSpaceBeforeProtocolList;
2945   }
2946   if (Right.is(tok::less) && Left.is(tok::kw_template))
2947     return Style.SpaceAfterTemplateKeyword;
2948   if (Left.isOneOf(tok::exclaim, tok::tilde))
2949     return false;
2950   if (Left.is(tok::at) &&
2951       Right.isOneOf(tok::identifier, tok::string_literal, tok::char_constant,
2952                     tok::numeric_constant, tok::l_paren, tok::l_brace,
2953                     tok::kw_true, tok::kw_false))
2954     return false;
2955   if (Left.is(tok::colon))
2956     return !Left.is(TT_ObjCMethodExpr);
2957   if (Left.is(tok::coloncolon))
2958     return false;
2959   if (Left.is(tok::less) || Right.isOneOf(tok::greater, tok::less)) {
2960     if (Style.Language == FormatStyle::LK_TextProto ||
2961         (Style.Language == FormatStyle::LK_Proto &&
2962          (Left.is(TT_DictLiteral) || Right.is(TT_DictLiteral)))) {
2963       // Format empty list as `<>`.
2964       if (Left.is(tok::less) && Right.is(tok::greater))
2965         return false;
2966       return !Style.Cpp11BracedListStyle;
2967     }
2968     return false;
2969   }
2970   if (Right.is(tok::ellipsis))
2971     return Left.Tok.isLiteral() || (Left.is(tok::identifier) && Left.Previous &&
2972                                     Left.Previous->is(tok::kw_case));
2973   if (Left.is(tok::l_square) && Right.is(tok::amp))
2974     return Style.SpacesInSquareBrackets;
2975   if (Right.is(TT_PointerOrReference)) {
2976     if (Left.is(tok::r_paren) && Line.MightBeFunctionDecl) {
2977       if (!Left.MatchingParen)
2978         return true;
2979       FormatToken *TokenBeforeMatchingParen =
2980           Left.MatchingParen->getPreviousNonComment();
2981       if (!TokenBeforeMatchingParen || !Left.is(TT_TypeDeclarationParen))
2982         return true;
2983     }
2984     // Add a space if the previous token is a pointer qualifer or the closing
2985     // parenthesis of __attribute__(()) expression and the style requires spaces
2986     // after pointer qualifiers.
2987     if ((Style.SpaceAroundPointerQualifiers == FormatStyle::SAPQ_After ||
2988          Style.SpaceAroundPointerQualifiers == FormatStyle::SAPQ_Both) &&
2989         (Left.is(TT_AttributeParen) || Left.canBePointerOrReferenceQualifier()))
2990       return true;
2991     return (
2992         Left.Tok.isLiteral() ||
2993         (!Left.isOneOf(TT_PointerOrReference, tok::l_paren) &&
2994          (getTokenPointerOrReferenceAlignment(Right) != FormatStyle::PAS_Left ||
2995           (Line.IsMultiVariableDeclStmt &&
2996            (Left.NestingLevel == 0 ||
2997             (Left.NestingLevel == 1 && Line.First->is(tok::kw_for)))))));
2998   }
2999   if (Right.is(TT_FunctionTypeLParen) && Left.isNot(tok::l_paren) &&
3000       (!Left.is(TT_PointerOrReference) ||
3001        (getTokenPointerOrReferenceAlignment(Left) != FormatStyle::PAS_Right &&
3002         !Line.IsMultiVariableDeclStmt)))
3003     return true;
3004   if (Left.is(TT_PointerOrReference)) {
3005     // Add a space if the next token is a pointer qualifer and the style
3006     // requires spaces before pointer qualifiers.
3007     if ((Style.SpaceAroundPointerQualifiers == FormatStyle::SAPQ_Before ||
3008          Style.SpaceAroundPointerQualifiers == FormatStyle::SAPQ_Both) &&
3009         Right.canBePointerOrReferenceQualifier())
3010       return true;
3011     return Right.Tok.isLiteral() || Right.is(TT_BlockComment) ||
3012            (Right.isOneOf(Keywords.kw_override, Keywords.kw_final) &&
3013             !Right.is(TT_StartOfName)) ||
3014            (Right.is(tok::l_brace) && Right.is(BK_Block)) ||
3015            (!Right.isOneOf(TT_PointerOrReference, TT_ArraySubscriptLSquare,
3016                            tok::l_paren) &&
3017             (getTokenPointerOrReferenceAlignment(Left) !=
3018                  FormatStyle::PAS_Right &&
3019              !Line.IsMultiVariableDeclStmt) &&
3020             Left.Previous &&
3021             !Left.Previous->isOneOf(tok::l_paren, tok::coloncolon,
3022                                     tok::l_square));
3023   }
3024   // Ensure right pointer alignement with ellipsis e.g. int *...P
3025   if (Left.is(tok::ellipsis) && Left.Previous &&
3026       Left.Previous->isOneOf(tok::star, tok::amp, tok::ampamp))
3027     return Style.PointerAlignment != FormatStyle::PAS_Right;
3028 
3029   if (Right.is(tok::star) && Left.is(tok::l_paren))
3030     return false;
3031   if (Left.is(tok::star) && Right.isOneOf(tok::star, tok::amp, tok::ampamp))
3032     return false;
3033   if (Right.isOneOf(tok::star, tok::amp, tok::ampamp)) {
3034     const FormatToken *Previous = &Left;
3035     while (Previous && !Previous->is(tok::kw_operator)) {
3036       if (Previous->is(tok::identifier) || Previous->isSimpleTypeSpecifier()) {
3037         Previous = Previous->getPreviousNonComment();
3038         continue;
3039       }
3040       if (Previous->is(TT_TemplateCloser) && Previous->MatchingParen) {
3041         Previous = Previous->MatchingParen->getPreviousNonComment();
3042         continue;
3043       }
3044       if (Previous->is(tok::coloncolon)) {
3045         Previous = Previous->getPreviousNonComment();
3046         continue;
3047       }
3048       break;
3049     }
3050     // Space between the type and the * in:
3051     //   operator void*()
3052     //   operator char*()
3053     //   operator void const*()
3054     //   operator void volatile*()
3055     //   operator /*comment*/ const char*()
3056     //   operator volatile /*comment*/ char*()
3057     //   operator Foo*()
3058     //   operator C<T>*()
3059     //   operator std::Foo*()
3060     //   operator C<T>::D<U>*()
3061     // dependent on PointerAlignment style.
3062     if (Previous) {
3063       if (Previous->endsSequence(tok::kw_operator))
3064         return (Style.PointerAlignment != FormatStyle::PAS_Left);
3065       if (Previous->is(tok::kw_const) || Previous->is(tok::kw_volatile))
3066         return (Style.PointerAlignment != FormatStyle::PAS_Left) ||
3067                (Style.SpaceAroundPointerQualifiers ==
3068                 FormatStyle::SAPQ_After) ||
3069                (Style.SpaceAroundPointerQualifiers == FormatStyle::SAPQ_Both);
3070     }
3071   }
3072   const auto SpaceRequiredForArrayInitializerLSquare =
3073       [](const FormatToken &LSquareTok, const FormatStyle &Style) {
3074         return Style.SpacesInContainerLiterals ||
3075                ((Style.Language == FormatStyle::LK_Proto ||
3076                  Style.Language == FormatStyle::LK_TextProto) &&
3077                 !Style.Cpp11BracedListStyle &&
3078                 LSquareTok.endsSequence(tok::l_square, tok::colon,
3079                                         TT_SelectorName));
3080       };
3081   if (Left.is(tok::l_square))
3082     return (Left.is(TT_ArrayInitializerLSquare) && Right.isNot(tok::r_square) &&
3083             SpaceRequiredForArrayInitializerLSquare(Left, Style)) ||
3084            (Left.isOneOf(TT_ArraySubscriptLSquare, TT_StructuredBindingLSquare,
3085                          TT_LambdaLSquare) &&
3086             Style.SpacesInSquareBrackets && Right.isNot(tok::r_square));
3087   if (Right.is(tok::r_square))
3088     return Right.MatchingParen &&
3089            ((Right.MatchingParen->is(TT_ArrayInitializerLSquare) &&
3090              SpaceRequiredForArrayInitializerLSquare(*Right.MatchingParen,
3091                                                      Style)) ||
3092             (Style.SpacesInSquareBrackets &&
3093              Right.MatchingParen->isOneOf(TT_ArraySubscriptLSquare,
3094                                           TT_StructuredBindingLSquare,
3095                                           TT_LambdaLSquare)) ||
3096             Right.MatchingParen->is(TT_AttributeParen));
3097   if (Right.is(tok::l_square) &&
3098       !Right.isOneOf(TT_ObjCMethodExpr, TT_LambdaLSquare,
3099                      TT_DesignatedInitializerLSquare,
3100                      TT_StructuredBindingLSquare, TT_AttributeSquare) &&
3101       !Left.isOneOf(tok::numeric_constant, TT_DictLiteral) &&
3102       !(!Left.is(tok::r_square) && Style.SpaceBeforeSquareBrackets &&
3103         Right.is(TT_ArraySubscriptLSquare)))
3104     return false;
3105   if (Left.is(tok::l_brace) && Right.is(tok::r_brace))
3106     return !Left.Children.empty(); // No spaces in "{}".
3107   if ((Left.is(tok::l_brace) && Left.isNot(BK_Block)) ||
3108       (Right.is(tok::r_brace) && Right.MatchingParen &&
3109        Right.MatchingParen->isNot(BK_Block)))
3110     return Style.Cpp11BracedListStyle ? Style.SpacesInParentheses : true;
3111   if (Left.is(TT_BlockComment))
3112     // No whitespace in x(/*foo=*/1), except for JavaScript.
3113     return Style.Language == FormatStyle::LK_JavaScript ||
3114            !Left.TokenText.endswith("=*/");
3115 
3116   // Space between template and attribute.
3117   // e.g. template <typename T> [[nodiscard]] ...
3118   if (Left.is(TT_TemplateCloser) && Right.is(TT_AttributeSquare))
3119     return true;
3120   if (Right.is(tok::l_paren)) {
3121     if ((Left.is(tok::r_paren) && Left.is(TT_AttributeParen)) ||
3122         (Left.is(tok::r_square) && Left.is(TT_AttributeSquare)))
3123       return true;
3124     if (Style.SpaceBeforeParens ==
3125             FormatStyle::SBPO_ControlStatementsExceptControlMacros &&
3126         Left.is(TT_ForEachMacro))
3127       return false;
3128     if (Style.SpaceBeforeParens ==
3129             FormatStyle::SBPO_ControlStatementsExceptControlMacros &&
3130         Left.is(TT_IfMacro))
3131       return false;
3132     return Line.Type == LT_ObjCDecl || Left.is(tok::semi) ||
3133            (Style.SpaceBeforeParens != FormatStyle::SBPO_Never &&
3134             (Left.isOneOf(tok::pp_elif, tok::kw_for, tok::kw_while,
3135                           tok::kw_switch, tok::kw_case, TT_ForEachMacro,
3136                           TT_ObjCForIn) ||
3137              Left.isIf(Line.Type != LT_PreprocessorDirective) ||
3138              (Left.isOneOf(tok::kw_try, Keywords.kw___except, tok::kw_catch,
3139                            tok::kw_new, tok::kw_delete) &&
3140               (!Left.Previous || Left.Previous->isNot(tok::period))))) ||
3141            (spaceRequiredBeforeParens(Right) &&
3142             (Left.is(tok::identifier) || Left.isFunctionLikeKeyword() ||
3143              Left.is(tok::r_paren) || Left.isSimpleTypeSpecifier() ||
3144              (Left.is(tok::r_square) && Left.MatchingParen &&
3145               Left.MatchingParen->is(TT_LambdaLSquare))) &&
3146             Line.Type != LT_PreprocessorDirective);
3147   }
3148   if (Left.is(tok::at) && Right.Tok.getObjCKeywordID() != tok::objc_not_keyword)
3149     return false;
3150   if (Right.is(TT_UnaryOperator))
3151     return !Left.isOneOf(tok::l_paren, tok::l_square, tok::at) &&
3152            (Left.isNot(tok::colon) || Left.isNot(TT_ObjCMethodExpr));
3153   if ((Left.isOneOf(tok::identifier, tok::greater, tok::r_square,
3154                     tok::r_paren) ||
3155        Left.isSimpleTypeSpecifier()) &&
3156       Right.is(tok::l_brace) && Right.getNextNonComment() &&
3157       Right.isNot(BK_Block))
3158     return false;
3159   if (Left.is(tok::period) || Right.is(tok::period))
3160     return false;
3161   if (Right.is(tok::hash) && Left.is(tok::identifier) && Left.TokenText == "L")
3162     return false;
3163   if (Left.is(TT_TemplateCloser) && Left.MatchingParen &&
3164       Left.MatchingParen->Previous &&
3165       (Left.MatchingParen->Previous->is(tok::period) ||
3166        Left.MatchingParen->Previous->is(tok::coloncolon)))
3167     // Java call to generic function with explicit type:
3168     // A.<B<C<...>>>DoSomething();
3169     // A::<B<C<...>>>DoSomething();  // With a Java 8 method reference.
3170     return false;
3171   if (Left.is(TT_TemplateCloser) && Right.is(tok::l_square))
3172     return false;
3173   if (Left.is(tok::l_brace) && Left.endsSequence(TT_DictLiteral, tok::at))
3174     // Objective-C dictionary literal -> no space after opening brace.
3175     return false;
3176   if (Right.is(tok::r_brace) && Right.MatchingParen &&
3177       Right.MatchingParen->endsSequence(TT_DictLiteral, tok::at))
3178     // Objective-C dictionary literal -> no space before closing brace.
3179     return false;
3180   if (Right.getType() == TT_TrailingAnnotation &&
3181       Right.isOneOf(tok::amp, tok::ampamp) &&
3182       Left.isOneOf(tok::kw_const, tok::kw_volatile) &&
3183       (!Right.Next || Right.Next->is(tok::semi)))
3184     // Match const and volatile ref-qualifiers without any additional
3185     // qualifiers such as
3186     // void Fn() const &;
3187     return getTokenReferenceAlignment(Right) != FormatStyle::PAS_Left;
3188   return true;
3189 }
3190 
3191 bool TokenAnnotator::spaceRequiredBefore(const AnnotatedLine &Line,
3192                                          const FormatToken &Right) {
3193   const FormatToken &Left = *Right.Previous;
3194   auto HasExistingWhitespace = [&Right]() {
3195     return Right.WhitespaceRange.getBegin() != Right.WhitespaceRange.getEnd();
3196   };
3197   if (Right.Tok.getIdentifierInfo() && Left.Tok.getIdentifierInfo())
3198     return true; // Never ever merge two identifiers.
3199   if (Style.isCpp()) {
3200     if (Left.is(tok::kw_operator))
3201       return Right.is(tok::coloncolon);
3202     if (Right.is(tok::l_brace) && Right.is(BK_BracedInit) &&
3203         !Left.opensScope() && Style.SpaceBeforeCpp11BracedList)
3204       return true;
3205   } else if (Style.Language == FormatStyle::LK_Proto ||
3206              Style.Language == FormatStyle::LK_TextProto) {
3207     if (Right.is(tok::period) &&
3208         Left.isOneOf(Keywords.kw_optional, Keywords.kw_required,
3209                      Keywords.kw_repeated, Keywords.kw_extend))
3210       return true;
3211     if (Right.is(tok::l_paren) &&
3212         Left.isOneOf(Keywords.kw_returns, Keywords.kw_option))
3213       return true;
3214     if (Right.isOneOf(tok::l_brace, tok::less) && Left.is(TT_SelectorName))
3215       return true;
3216     // Slashes occur in text protocol extension syntax: [type/type] { ... }.
3217     if (Left.is(tok::slash) || Right.is(tok::slash))
3218       return false;
3219     if (Left.MatchingParen &&
3220         Left.MatchingParen->is(TT_ProtoExtensionLSquare) &&
3221         Right.isOneOf(tok::l_brace, tok::less))
3222       return !Style.Cpp11BracedListStyle;
3223     // A percent is probably part of a formatting specification, such as %lld.
3224     if (Left.is(tok::percent))
3225       return false;
3226     // Preserve the existence of a space before a percent for cases like 0x%04x
3227     // and "%d %d"
3228     if (Left.is(tok::numeric_constant) && Right.is(tok::percent))
3229       return HasExistingWhitespace();
3230   } else if (Style.isCSharp()) {
3231     // Require spaces around '{' and  before '}' unless they appear in
3232     // interpolated strings. Interpolated strings are merged into a single token
3233     // so cannot have spaces inserted by this function.
3234 
3235     // No space between 'this' and '['
3236     if (Left.is(tok::kw_this) && Right.is(tok::l_square))
3237       return false;
3238 
3239     // No space between 'new' and '('
3240     if (Left.is(tok::kw_new) && Right.is(tok::l_paren))
3241       return false;
3242 
3243     // Space before { (including space within '{ {').
3244     if (Right.is(tok::l_brace))
3245       return true;
3246 
3247     // Spaces inside braces.
3248     if (Left.is(tok::l_brace) && Right.isNot(tok::r_brace))
3249       return true;
3250 
3251     if (Left.isNot(tok::l_brace) && Right.is(tok::r_brace))
3252       return true;
3253 
3254     // Spaces around '=>'.
3255     if (Left.is(TT_FatArrow) || Right.is(TT_FatArrow))
3256       return true;
3257 
3258     // No spaces around attribute target colons
3259     if (Left.is(TT_AttributeColon) || Right.is(TT_AttributeColon))
3260       return false;
3261 
3262     // space between type and variable e.g. Dictionary<string,string> foo;
3263     if (Left.is(TT_TemplateCloser) && Right.is(TT_StartOfName))
3264       return true;
3265 
3266     // spaces inside square brackets.
3267     if (Left.is(tok::l_square) || Right.is(tok::r_square))
3268       return Style.SpacesInSquareBrackets;
3269 
3270     // No space before ? in nullable types.
3271     if (Right.is(TT_CSharpNullable))
3272       return false;
3273 
3274     // No space before null forgiving '!'.
3275     if (Right.is(TT_NonNullAssertion))
3276       return false;
3277 
3278     // No space between consecutive commas '[,,]'.
3279     if (Left.is(tok::comma) && Right.is(tok::comma))
3280       return false;
3281 
3282     // space after var in `var (key, value)`
3283     if (Left.is(Keywords.kw_var) && Right.is(tok::l_paren))
3284       return true;
3285 
3286     // space between keywords and paren e.g. "using ("
3287     if (Right.is(tok::l_paren))
3288       if (Left.isOneOf(tok::kw_using, Keywords.kw_async, Keywords.kw_when,
3289                        Keywords.kw_lock))
3290         return Style.SpaceBeforeParens == FormatStyle::SBPO_ControlStatements ||
3291                spaceRequiredBeforeParens(Right);
3292 
3293     // space between method modifier and opening parenthesis of a tuple return
3294     // type
3295     if (Left.isOneOf(tok::kw_public, tok::kw_private, tok::kw_protected,
3296                      tok::kw_virtual, tok::kw_extern, tok::kw_static,
3297                      Keywords.kw_internal, Keywords.kw_abstract,
3298                      Keywords.kw_sealed, Keywords.kw_override,
3299                      Keywords.kw_async, Keywords.kw_unsafe) &&
3300         Right.is(tok::l_paren))
3301       return true;
3302   } else if (Style.Language == FormatStyle::LK_JavaScript) {
3303     if (Left.is(TT_FatArrow))
3304       return true;
3305     // for await ( ...
3306     if (Right.is(tok::l_paren) && Left.is(Keywords.kw_await) && Left.Previous &&
3307         Left.Previous->is(tok::kw_for))
3308       return true;
3309     if (Left.is(Keywords.kw_async) && Right.is(tok::l_paren) &&
3310         Right.MatchingParen) {
3311       const FormatToken *Next = Right.MatchingParen->getNextNonComment();
3312       // An async arrow function, for example: `x = async () => foo();`,
3313       // as opposed to calling a function called async: `x = async();`
3314       if (Next && Next->is(TT_FatArrow))
3315         return true;
3316     }
3317     if ((Left.is(TT_TemplateString) && Left.TokenText.endswith("${")) ||
3318         (Right.is(TT_TemplateString) && Right.TokenText.startswith("}")))
3319       return false;
3320     // In tagged template literals ("html`bar baz`"), there is no space between
3321     // the tag identifier and the template string.
3322     if (Keywords.IsJavaScriptIdentifier(Left,
3323                                         /* AcceptIdentifierName= */ false) &&
3324         Right.is(TT_TemplateString))
3325       return false;
3326     if (Right.is(tok::star) &&
3327         Left.isOneOf(Keywords.kw_function, Keywords.kw_yield))
3328       return false;
3329     if (Right.isOneOf(tok::l_brace, tok::l_square) &&
3330         Left.isOneOf(Keywords.kw_function, Keywords.kw_yield,
3331                      Keywords.kw_extends, Keywords.kw_implements))
3332       return true;
3333     if (Right.is(tok::l_paren)) {
3334       // JS methods can use some keywords as names (e.g. `delete()`).
3335       if (Line.MustBeDeclaration && Left.Tok.getIdentifierInfo())
3336         return false;
3337       // Valid JS method names can include keywords, e.g. `foo.delete()` or
3338       // `bar.instanceof()`. Recognize call positions by preceding period.
3339       if (Left.Previous && Left.Previous->is(tok::period) &&
3340           Left.Tok.getIdentifierInfo())
3341         return false;
3342       // Additional unary JavaScript operators that need a space after.
3343       if (Left.isOneOf(tok::kw_throw, Keywords.kw_await, Keywords.kw_typeof,
3344                        tok::kw_void))
3345         return true;
3346     }
3347     // `foo as const;` casts into a const type.
3348     if (Left.endsSequence(tok::kw_const, Keywords.kw_as)) {
3349       return false;
3350     }
3351     if ((Left.isOneOf(Keywords.kw_let, Keywords.kw_var, Keywords.kw_in,
3352                       tok::kw_const) ||
3353          // "of" is only a keyword if it appears after another identifier
3354          // (e.g. as "const x of y" in a for loop), or after a destructuring
3355          // operation (const [x, y] of z, const {a, b} of c).
3356          (Left.is(Keywords.kw_of) && Left.Previous &&
3357           (Left.Previous->Tok.is(tok::identifier) ||
3358            Left.Previous->isOneOf(tok::r_square, tok::r_brace)))) &&
3359         (!Left.Previous || !Left.Previous->is(tok::period)))
3360       return true;
3361     if (Left.isOneOf(tok::kw_for, Keywords.kw_as) && Left.Previous &&
3362         Left.Previous->is(tok::period) && Right.is(tok::l_paren))
3363       return false;
3364     if (Left.is(Keywords.kw_as) &&
3365         Right.isOneOf(tok::l_square, tok::l_brace, tok::l_paren))
3366       return true;
3367     if (Left.is(tok::kw_default) && Left.Previous &&
3368         Left.Previous->is(tok::kw_export))
3369       return true;
3370     if (Left.is(Keywords.kw_is) && Right.is(tok::l_brace))
3371       return true;
3372     if (Right.isOneOf(TT_JsTypeColon, TT_JsTypeOptionalQuestion))
3373       return false;
3374     if (Left.is(TT_JsTypeOperator) || Right.is(TT_JsTypeOperator))
3375       return false;
3376     if ((Left.is(tok::l_brace) || Right.is(tok::r_brace)) &&
3377         Line.First->isOneOf(Keywords.kw_import, tok::kw_export))
3378       return false;
3379     if (Left.is(tok::ellipsis))
3380       return false;
3381     if (Left.is(TT_TemplateCloser) &&
3382         !Right.isOneOf(tok::equal, tok::l_brace, tok::comma, tok::l_square,
3383                        Keywords.kw_implements, Keywords.kw_extends))
3384       // Type assertions ('<type>expr') are not followed by whitespace. Other
3385       // locations that should have whitespace following are identified by the
3386       // above set of follower tokens.
3387       return false;
3388     if (Right.is(TT_NonNullAssertion))
3389       return false;
3390     if (Left.is(TT_NonNullAssertion) &&
3391         Right.isOneOf(Keywords.kw_as, Keywords.kw_in))
3392       return true; // "x! as string", "x! in y"
3393   } else if (Style.Language == FormatStyle::LK_Java) {
3394     if (Left.is(tok::r_square) && Right.is(tok::l_brace))
3395       return true;
3396     if (Left.is(Keywords.kw_synchronized) && Right.is(tok::l_paren))
3397       return Style.SpaceBeforeParens != FormatStyle::SBPO_Never;
3398     if ((Left.isOneOf(tok::kw_static, tok::kw_public, tok::kw_private,
3399                       tok::kw_protected) ||
3400          Left.isOneOf(Keywords.kw_final, Keywords.kw_abstract,
3401                       Keywords.kw_native)) &&
3402         Right.is(TT_TemplateOpener))
3403       return true;
3404   }
3405   if (Left.is(TT_ImplicitStringLiteral))
3406     return HasExistingWhitespace();
3407   if (Line.Type == LT_ObjCMethodDecl) {
3408     if (Left.is(TT_ObjCMethodSpecifier))
3409       return true;
3410     if (Left.is(tok::r_paren) && canBeObjCSelectorComponent(Right))
3411       // Don't space between ')' and <id> or ')' and 'new'. 'new' is not a
3412       // keyword in Objective-C, and '+ (instancetype)new;' is a standard class
3413       // method declaration.
3414       return false;
3415   }
3416   if (Line.Type == LT_ObjCProperty &&
3417       (Right.is(tok::equal) || Left.is(tok::equal)))
3418     return false;
3419 
3420   if (Right.isOneOf(TT_TrailingReturnArrow, TT_LambdaArrow) ||
3421       Left.isOneOf(TT_TrailingReturnArrow, TT_LambdaArrow))
3422     return true;
3423   if (Right.is(TT_OverloadedOperatorLParen))
3424     return spaceRequiredBeforeParens(Right);
3425   if (Left.is(tok::comma))
3426     return true;
3427   if (Right.is(tok::comma))
3428     return false;
3429   if (Right.is(TT_ObjCBlockLParen))
3430     return true;
3431   if (Right.is(TT_CtorInitializerColon))
3432     return Style.SpaceBeforeCtorInitializerColon;
3433   if (Right.is(TT_InheritanceColon) && !Style.SpaceBeforeInheritanceColon)
3434     return false;
3435   if (Right.is(TT_RangeBasedForLoopColon) &&
3436       !Style.SpaceBeforeRangeBasedForLoopColon)
3437     return false;
3438   if (Left.is(TT_BitFieldColon))
3439     return Style.BitFieldColonSpacing == FormatStyle::BFCS_Both ||
3440            Style.BitFieldColonSpacing == FormatStyle::BFCS_After;
3441   if (Right.is(tok::colon)) {
3442     if (Line.First->isOneOf(tok::kw_default, tok::kw_case))
3443       return Style.SpaceBeforeCaseColon;
3444     if (!Right.getNextNonComment() || Right.getNextNonComment()->is(tok::semi))
3445       return false;
3446     if (Right.is(TT_ObjCMethodExpr))
3447       return false;
3448     if (Left.is(tok::question))
3449       return false;
3450     if (Right.is(TT_InlineASMColon) && Left.is(tok::coloncolon))
3451       return false;
3452     if (Right.is(TT_DictLiteral))
3453       return Style.SpacesInContainerLiterals;
3454     if (Right.is(TT_AttributeColon))
3455       return false;
3456     if (Right.is(TT_CSharpNamedArgumentColon))
3457       return false;
3458     if (Right.is(TT_BitFieldColon))
3459       return Style.BitFieldColonSpacing == FormatStyle::BFCS_Both ||
3460              Style.BitFieldColonSpacing == FormatStyle::BFCS_Before;
3461     return true;
3462   }
3463   // Do not merge "- -" into "--".
3464   if ((Left.isOneOf(tok::minus, tok::minusminus) &&
3465        Right.isOneOf(tok::minus, tok::minusminus)) ||
3466       (Left.isOneOf(tok::plus, tok::plusplus) &&
3467        Right.isOneOf(tok::plus, tok::plusplus)))
3468     return true;
3469   if (Left.is(TT_UnaryOperator)) {
3470     if (!Right.is(tok::l_paren)) {
3471       // The alternative operators for ~ and ! are "compl" and "not".
3472       // If they are used instead, we do not want to combine them with
3473       // the token to the right, unless that is a left paren.
3474       if (Left.is(tok::exclaim) && Left.TokenText == "not")
3475         return true;
3476       if (Left.is(tok::tilde) && Left.TokenText == "compl")
3477         return true;
3478       // Lambda captures allow for a lone &, so "&]" needs to be properly
3479       // handled.
3480       if (Left.is(tok::amp) && Right.is(tok::r_square))
3481         return Style.SpacesInSquareBrackets;
3482     }
3483     return (Style.SpaceAfterLogicalNot && Left.is(tok::exclaim)) ||
3484            Right.is(TT_BinaryOperator);
3485   }
3486 
3487   // If the next token is a binary operator or a selector name, we have
3488   // incorrectly classified the parenthesis as a cast. FIXME: Detect correctly.
3489   if (Left.is(TT_CastRParen))
3490     return Style.SpaceAfterCStyleCast ||
3491            Right.isOneOf(TT_BinaryOperator, TT_SelectorName);
3492 
3493   auto ShouldAddSpacesInAngles = [this, &HasExistingWhitespace]() {
3494     if (this->Style.SpacesInAngles == FormatStyle::SIAS_Always)
3495       return true;
3496     if (this->Style.SpacesInAngles == FormatStyle::SIAS_Leave)
3497       return HasExistingWhitespace();
3498     return false;
3499   };
3500 
3501   if (Left.is(tok::greater) && Right.is(tok::greater)) {
3502     if (Style.Language == FormatStyle::LK_TextProto ||
3503         (Style.Language == FormatStyle::LK_Proto && Left.is(TT_DictLiteral)))
3504       return !Style.Cpp11BracedListStyle;
3505     return Right.is(TT_TemplateCloser) && Left.is(TT_TemplateCloser) &&
3506            ((Style.Standard < FormatStyle::LS_Cpp11) ||
3507             ShouldAddSpacesInAngles());
3508   }
3509   if (Right.isOneOf(tok::arrow, tok::arrowstar, tok::periodstar) ||
3510       Left.isOneOf(tok::arrow, tok::period, tok::arrowstar, tok::periodstar) ||
3511       (Right.is(tok::period) && Right.isNot(TT_DesignatedInitializerPeriod)))
3512     return false;
3513   if (!Style.SpaceBeforeAssignmentOperators && Left.isNot(TT_TemplateCloser) &&
3514       Right.getPrecedence() == prec::Assignment)
3515     return false;
3516   if (Style.Language == FormatStyle::LK_Java && Right.is(tok::coloncolon) &&
3517       (Left.is(tok::identifier) || Left.is(tok::kw_this)))
3518     return false;
3519   if (Right.is(tok::coloncolon) && Left.is(tok::identifier))
3520     // Generally don't remove existing spaces between an identifier and "::".
3521     // The identifier might actually be a macro name such as ALWAYS_INLINE. If
3522     // this turns out to be too lenient, add analysis of the identifier itself.
3523     return HasExistingWhitespace();
3524   if (Right.is(tok::coloncolon) &&
3525       !Left.isOneOf(tok::l_brace, tok::comment, tok::l_paren))
3526     // Put a space between < and :: in vector< ::std::string >
3527     return (Left.is(TT_TemplateOpener) &&
3528             ((Style.Standard < FormatStyle::LS_Cpp11) ||
3529              ShouldAddSpacesInAngles())) ||
3530            !(Left.isOneOf(tok::l_paren, tok::r_paren, tok::l_square,
3531                           tok::kw___super, TT_TemplateOpener,
3532                           TT_TemplateCloser)) ||
3533            (Left.is(tok::l_paren) && Style.SpacesInParentheses);
3534   if ((Left.is(TT_TemplateOpener)) != (Right.is(TT_TemplateCloser)))
3535     return ShouldAddSpacesInAngles();
3536   // Space before TT_StructuredBindingLSquare.
3537   if (Right.is(TT_StructuredBindingLSquare))
3538     return !Left.isOneOf(tok::amp, tok::ampamp) ||
3539            getTokenReferenceAlignment(Left) != FormatStyle::PAS_Right;
3540   // Space before & or && following a TT_StructuredBindingLSquare.
3541   if (Right.Next && Right.Next->is(TT_StructuredBindingLSquare) &&
3542       Right.isOneOf(tok::amp, tok::ampamp))
3543     return getTokenReferenceAlignment(Right) != FormatStyle::PAS_Left;
3544   if ((Right.is(TT_BinaryOperator) && !Left.is(tok::l_paren)) ||
3545       (Left.isOneOf(TT_BinaryOperator, TT_ConditionalExpr) &&
3546        !Right.is(tok::r_paren)))
3547     return true;
3548   if (Left.is(TT_TemplateCloser) && Right.is(tok::l_paren) &&
3549       Right.isNot(TT_FunctionTypeLParen))
3550     return spaceRequiredBeforeParens(Right);
3551   if (Right.is(TT_TemplateOpener) && Left.is(tok::r_paren) &&
3552       Left.MatchingParen && Left.MatchingParen->is(TT_OverloadedOperatorLParen))
3553     return false;
3554   if (Right.is(tok::less) && Left.isNot(tok::l_paren) &&
3555       Line.startsWith(tok::hash))
3556     return true;
3557   if (Right.is(TT_TrailingUnaryOperator))
3558     return false;
3559   if (Left.is(TT_RegexLiteral))
3560     return false;
3561   return spaceRequiredBetween(Line, Left, Right);
3562 }
3563 
3564 // Returns 'true' if 'Tok' is a brace we'd want to break before in Allman style.
3565 static bool isAllmanBrace(const FormatToken &Tok) {
3566   return Tok.is(tok::l_brace) && Tok.is(BK_Block) &&
3567          !Tok.isOneOf(TT_ObjCBlockLBrace, TT_LambdaLBrace, TT_DictLiteral);
3568 }
3569 
3570 // Returns 'true' if 'Tok' is an function argument.
3571 static bool IsFunctionArgument(const FormatToken &Tok) {
3572   return Tok.MatchingParen && Tok.MatchingParen->Next &&
3573          Tok.MatchingParen->Next->isOneOf(tok::comma, tok::r_paren);
3574 }
3575 
3576 static bool
3577 isItAnEmptyLambdaAllowed(const FormatToken &Tok,
3578                          FormatStyle::ShortLambdaStyle ShortLambdaOption) {
3579   return Tok.Children.empty() && ShortLambdaOption != FormatStyle::SLS_None;
3580 }
3581 
3582 static bool
3583 isItAInlineLambdaAllowed(const FormatToken &Tok,
3584                          FormatStyle::ShortLambdaStyle ShortLambdaOption) {
3585   return (ShortLambdaOption == FormatStyle::SLS_Inline &&
3586           IsFunctionArgument(Tok)) ||
3587          (ShortLambdaOption == FormatStyle::SLS_All);
3588 }
3589 
3590 static bool isOneChildWithoutMustBreakBefore(const FormatToken &Tok) {
3591   if (Tok.Children.size() != 1)
3592     return false;
3593   FormatToken *curElt = Tok.Children[0]->First;
3594   while (curElt) {
3595     if (curElt->MustBreakBefore)
3596       return false;
3597     curElt = curElt->Next;
3598   }
3599   return true;
3600 }
3601 static bool isAllmanLambdaBrace(const FormatToken &Tok) {
3602   return (Tok.is(tok::l_brace) && Tok.is(BK_Block) &&
3603           !Tok.isOneOf(TT_ObjCBlockLBrace, TT_DictLiteral));
3604 }
3605 
3606 static bool isAllmanBraceIncludedBreakableLambda(
3607     const FormatToken &Tok, FormatStyle::ShortLambdaStyle ShortLambdaOption) {
3608   if (!isAllmanLambdaBrace(Tok))
3609     return false;
3610 
3611   if (isItAnEmptyLambdaAllowed(Tok, ShortLambdaOption))
3612     return false;
3613 
3614   return !isItAInlineLambdaAllowed(Tok, ShortLambdaOption) ||
3615          !isOneChildWithoutMustBreakBefore(Tok);
3616 }
3617 
3618 bool TokenAnnotator::mustBreakBefore(const AnnotatedLine &Line,
3619                                      const FormatToken &Right) {
3620   const FormatToken &Left = *Right.Previous;
3621   if (Right.NewlinesBefore > 1 && Style.MaxEmptyLinesToKeep > 0)
3622     return true;
3623 
3624   if (Style.isCSharp()) {
3625     if (Right.is(TT_CSharpNamedArgumentColon) ||
3626         Left.is(TT_CSharpNamedArgumentColon))
3627       return false;
3628     if (Right.is(TT_CSharpGenericTypeConstraint))
3629       return true;
3630 
3631     // Break after C# [...] and before public/protected/private/internal.
3632     if (Left.is(TT_AttributeSquare) && Left.is(tok::r_square) &&
3633         (Right.isAccessSpecifier(/*ColonRequired=*/false) ||
3634          Right.is(Keywords.kw_internal)))
3635       return true;
3636     // Break between ] and [ but only when there are really 2 attributes.
3637     if (Left.is(TT_AttributeSquare) && Right.is(TT_AttributeSquare) &&
3638         Left.is(tok::r_square) && Right.is(tok::l_square))
3639       return true;
3640 
3641   } else if (Style.Language == FormatStyle::LK_JavaScript) {
3642     // FIXME: This might apply to other languages and token kinds.
3643     if (Right.is(tok::string_literal) && Left.is(tok::plus) && Left.Previous &&
3644         Left.Previous->is(tok::string_literal))
3645       return true;
3646     if (Left.is(TT_DictLiteral) && Left.is(tok::l_brace) && Line.Level == 0 &&
3647         Left.Previous && Left.Previous->is(tok::equal) &&
3648         Line.First->isOneOf(tok::identifier, Keywords.kw_import, tok::kw_export,
3649                             tok::kw_const) &&
3650         // kw_var/kw_let are pseudo-tokens that are tok::identifier, so match
3651         // above.
3652         !Line.First->isOneOf(Keywords.kw_var, Keywords.kw_let))
3653       // Object literals on the top level of a file are treated as "enum-style".
3654       // Each key/value pair is put on a separate line, instead of bin-packing.
3655       return true;
3656     if (Left.is(tok::l_brace) && Line.Level == 0 &&
3657         (Line.startsWith(tok::kw_enum) ||
3658          Line.startsWith(tok::kw_const, tok::kw_enum) ||
3659          Line.startsWith(tok::kw_export, tok::kw_enum) ||
3660          Line.startsWith(tok::kw_export, tok::kw_const, tok::kw_enum)))
3661       // JavaScript top-level enum key/value pairs are put on separate lines
3662       // instead of bin-packing.
3663       return true;
3664     if (Right.is(tok::r_brace) && Left.is(tok::l_brace) && Left.Previous &&
3665         Left.Previous->is(TT_FatArrow)) {
3666       // JS arrow function (=> {...}).
3667       switch (Style.AllowShortLambdasOnASingleLine) {
3668       case FormatStyle::SLS_All:
3669         return false;
3670       case FormatStyle::SLS_None:
3671         return true;
3672       case FormatStyle::SLS_Empty:
3673         return !Left.Children.empty();
3674       case FormatStyle::SLS_Inline:
3675         // allow one-lining inline (e.g. in function call args) and empty arrow
3676         // functions.
3677         return (Left.NestingLevel == 0 && Line.Level == 0) &&
3678                !Left.Children.empty();
3679       }
3680       llvm_unreachable("Unknown FormatStyle::ShortLambdaStyle enum");
3681     }
3682 
3683     if (Right.is(tok::r_brace) && Left.is(tok::l_brace) &&
3684         !Left.Children.empty())
3685       // Support AllowShortFunctionsOnASingleLine for JavaScript.
3686       return Style.AllowShortFunctionsOnASingleLine == FormatStyle::SFS_None ||
3687              Style.AllowShortFunctionsOnASingleLine == FormatStyle::SFS_Empty ||
3688              (Left.NestingLevel == 0 && Line.Level == 0 &&
3689               Style.AllowShortFunctionsOnASingleLine &
3690                   FormatStyle::SFS_InlineOnly);
3691   } else if (Style.Language == FormatStyle::LK_Java) {
3692     if (Right.is(tok::plus) && Left.is(tok::string_literal) && Right.Next &&
3693         Right.Next->is(tok::string_literal))
3694       return true;
3695   } else if (Style.Language == FormatStyle::LK_Cpp ||
3696              Style.Language == FormatStyle::LK_ObjC ||
3697              Style.Language == FormatStyle::LK_Proto ||
3698              Style.Language == FormatStyle::LK_TableGen ||
3699              Style.Language == FormatStyle::LK_TextProto) {
3700     if (Left.isStringLiteral() && Right.isStringLiteral())
3701       return true;
3702   }
3703 
3704   // If the last token before a '}', ']', or ')' is a comma or a trailing
3705   // comment, the intention is to insert a line break after it in order to make
3706   // shuffling around entries easier. Import statements, especially in
3707   // JavaScript, can be an exception to this rule.
3708   if (Style.JavaScriptWrapImports || Line.Type != LT_ImportStatement) {
3709     const FormatToken *BeforeClosingBrace = nullptr;
3710     if ((Left.isOneOf(tok::l_brace, TT_ArrayInitializerLSquare) ||
3711          (Style.Language == FormatStyle::LK_JavaScript &&
3712           Left.is(tok::l_paren))) &&
3713         Left.isNot(BK_Block) && Left.MatchingParen)
3714       BeforeClosingBrace = Left.MatchingParen->Previous;
3715     else if (Right.MatchingParen &&
3716              (Right.MatchingParen->isOneOf(tok::l_brace,
3717                                            TT_ArrayInitializerLSquare) ||
3718               (Style.Language == FormatStyle::LK_JavaScript &&
3719                Right.MatchingParen->is(tok::l_paren))))
3720       BeforeClosingBrace = &Left;
3721     if (BeforeClosingBrace && (BeforeClosingBrace->is(tok::comma) ||
3722                                BeforeClosingBrace->isTrailingComment()))
3723       return true;
3724   }
3725 
3726   if (Right.is(tok::comment))
3727     return Left.isNot(BK_BracedInit) && Left.isNot(TT_CtorInitializerColon) &&
3728            (Right.NewlinesBefore > 0 && Right.HasUnescapedNewline);
3729   if (Left.isTrailingComment())
3730     return true;
3731   if (Right.Previous->IsUnterminatedLiteral)
3732     return true;
3733   if (Right.is(tok::lessless) && Right.Next &&
3734       Right.Previous->is(tok::string_literal) &&
3735       Right.Next->is(tok::string_literal))
3736     return true;
3737   // Can break after template<> declaration
3738   if (Right.Previous->ClosesTemplateDeclaration &&
3739       Right.Previous->MatchingParen &&
3740       Right.Previous->MatchingParen->NestingLevel == 0) {
3741     // Put concepts on the next line e.g.
3742     // template<typename T>
3743     // concept ...
3744     if (Right.is(tok::kw_concept))
3745       return Style.BreakBeforeConceptDeclarations;
3746     return (Style.AlwaysBreakTemplateDeclarations == FormatStyle::BTDS_Yes);
3747   }
3748   if (Right.is(TT_CtorInitializerComma) &&
3749       Style.BreakConstructorInitializers == FormatStyle::BCIS_BeforeComma &&
3750       !Style.ConstructorInitializerAllOnOneLineOrOnePerLine)
3751     return true;
3752   if (Right.is(TT_CtorInitializerColon) &&
3753       Style.BreakConstructorInitializers == FormatStyle::BCIS_BeforeComma &&
3754       !Style.ConstructorInitializerAllOnOneLineOrOnePerLine)
3755     return true;
3756   // Break only if we have multiple inheritance.
3757   if (Style.BreakInheritanceList == FormatStyle::BILS_BeforeComma &&
3758       Right.is(TT_InheritanceComma))
3759     return true;
3760   if (Style.BreakInheritanceList == FormatStyle::BILS_AfterComma &&
3761       Left.is(TT_InheritanceComma))
3762     return true;
3763   if (Right.is(tok::string_literal) && Right.TokenText.startswith("R\""))
3764     // Multiline raw string literals are special wrt. line breaks. The author
3765     // has made a deliberate choice and might have aligned the contents of the
3766     // string literal accordingly. Thus, we try keep existing line breaks.
3767     return Right.IsMultiline && Right.NewlinesBefore > 0;
3768   if ((Right.Previous->is(tok::l_brace) ||
3769        (Right.Previous->is(tok::less) && Right.Previous->Previous &&
3770         Right.Previous->Previous->is(tok::equal))) &&
3771       Right.NestingLevel == 1 && Style.Language == FormatStyle::LK_Proto) {
3772     // Don't put enums or option definitions onto single lines in protocol
3773     // buffers.
3774     return true;
3775   }
3776   if (Right.is(TT_InlineASMBrace))
3777     return Right.HasUnescapedNewline;
3778 
3779   auto ShortLambdaOption = Style.AllowShortLambdasOnASingleLine;
3780   if (Style.BraceWrapping.BeforeLambdaBody &&
3781       (isAllmanBraceIncludedBreakableLambda(Left, ShortLambdaOption) ||
3782        isAllmanBraceIncludedBreakableLambda(Right, ShortLambdaOption))) {
3783     return true;
3784   }
3785 
3786   if (isAllmanBrace(Left) || isAllmanBrace(Right))
3787     return (Line.startsWith(tok::kw_enum) && Style.BraceWrapping.AfterEnum) ||
3788            (Line.startsWith(tok::kw_typedef, tok::kw_enum) &&
3789             Style.BraceWrapping.AfterEnum) ||
3790            (Line.startsWith(tok::kw_class) && Style.BraceWrapping.AfterClass) ||
3791            (Line.startsWith(tok::kw_struct) && Style.BraceWrapping.AfterStruct);
3792   if (Left.is(TT_ObjCBlockLBrace) &&
3793       Style.AllowShortBlocksOnASingleLine == FormatStyle::SBS_Never)
3794     return true;
3795 
3796   if (Left.is(TT_LambdaLBrace)) {
3797     if (IsFunctionArgument(Left) &&
3798         Style.AllowShortLambdasOnASingleLine == FormatStyle::SLS_Inline)
3799       return false;
3800 
3801     if (Style.AllowShortLambdasOnASingleLine == FormatStyle::SLS_None ||
3802         Style.AllowShortLambdasOnASingleLine == FormatStyle::SLS_Inline ||
3803         (!Left.Children.empty() &&
3804          Style.AllowShortLambdasOnASingleLine == FormatStyle::SLS_Empty))
3805       return true;
3806   }
3807 
3808   // Put multiple Java annotation on a new line.
3809   if ((Style.Language == FormatStyle::LK_Java ||
3810        Style.Language == FormatStyle::LK_JavaScript) &&
3811       Left.is(TT_LeadingJavaAnnotation) &&
3812       Right.isNot(TT_LeadingJavaAnnotation) && Right.isNot(tok::l_paren) &&
3813       (Line.Last->is(tok::l_brace) || Style.BreakAfterJavaFieldAnnotations))
3814     return true;
3815 
3816   if (Right.is(TT_ProtoExtensionLSquare))
3817     return true;
3818 
3819   // In text proto instances if a submessage contains at least 2 entries and at
3820   // least one of them is a submessage, like A { ... B { ... } ... },
3821   // put all of the entries of A on separate lines by forcing the selector of
3822   // the submessage B to be put on a newline.
3823   //
3824   // Example: these can stay on one line:
3825   // a { scalar_1: 1 scalar_2: 2 }
3826   // a { b { key: value } }
3827   //
3828   // and these entries need to be on a new line even if putting them all in one
3829   // line is under the column limit:
3830   // a {
3831   //   scalar: 1
3832   //   b { key: value }
3833   // }
3834   //
3835   // We enforce this by breaking before a submessage field that has previous
3836   // siblings, *and* breaking before a field that follows a submessage field.
3837   //
3838   // Be careful to exclude the case  [proto.ext] { ... } since the `]` is
3839   // the TT_SelectorName there, but we don't want to break inside the brackets.
3840   //
3841   // Another edge case is @submessage { key: value }, which is a common
3842   // substitution placeholder. In this case we want to keep `@` and `submessage`
3843   // together.
3844   //
3845   // We ensure elsewhere that extensions are always on their own line.
3846   if ((Style.Language == FormatStyle::LK_Proto ||
3847        Style.Language == FormatStyle::LK_TextProto) &&
3848       Right.is(TT_SelectorName) && !Right.is(tok::r_square) && Right.Next) {
3849     // Keep `@submessage` together in:
3850     // @submessage { key: value }
3851     if (Right.Previous && Right.Previous->is(tok::at))
3852       return false;
3853     // Look for the scope opener after selector in cases like:
3854     // selector { ...
3855     // selector: { ...
3856     // selector: @base { ...
3857     FormatToken *LBrace = Right.Next;
3858     if (LBrace && LBrace->is(tok::colon)) {
3859       LBrace = LBrace->Next;
3860       if (LBrace && LBrace->is(tok::at)) {
3861         LBrace = LBrace->Next;
3862         if (LBrace)
3863           LBrace = LBrace->Next;
3864       }
3865     }
3866     if (LBrace &&
3867         // The scope opener is one of {, [, <:
3868         // selector { ... }
3869         // selector [ ... ]
3870         // selector < ... >
3871         //
3872         // In case of selector { ... }, the l_brace is TT_DictLiteral.
3873         // In case of an empty selector {}, the l_brace is not TT_DictLiteral,
3874         // so we check for immediately following r_brace.
3875         ((LBrace->is(tok::l_brace) &&
3876           (LBrace->is(TT_DictLiteral) ||
3877            (LBrace->Next && LBrace->Next->is(tok::r_brace)))) ||
3878          LBrace->is(TT_ArrayInitializerLSquare) || LBrace->is(tok::less))) {
3879       // If Left.ParameterCount is 0, then this submessage entry is not the
3880       // first in its parent submessage, and we want to break before this entry.
3881       // If Left.ParameterCount is greater than 0, then its parent submessage
3882       // might contain 1 or more entries and we want to break before this entry
3883       // if it contains at least 2 entries. We deal with this case later by
3884       // detecting and breaking before the next entry in the parent submessage.
3885       if (Left.ParameterCount == 0)
3886         return true;
3887       // However, if this submessage is the first entry in its parent
3888       // submessage, Left.ParameterCount might be 1 in some cases.
3889       // We deal with this case later by detecting an entry
3890       // following a closing paren of this submessage.
3891     }
3892 
3893     // If this is an entry immediately following a submessage, it will be
3894     // preceded by a closing paren of that submessage, like in:
3895     //     left---.  .---right
3896     //            v  v
3897     // sub: { ... } key: value
3898     // If there was a comment between `}` an `key` above, then `key` would be
3899     // put on a new line anyways.
3900     if (Left.isOneOf(tok::r_brace, tok::greater, tok::r_square))
3901       return true;
3902   }
3903 
3904   // Deal with lambda arguments in C++ - we want consistent line breaks whether
3905   // they happen to be at arg0, arg1 or argN. The selection is a bit nuanced
3906   // as aggressive line breaks are placed when the lambda is not the last arg.
3907   if ((Style.Language == FormatStyle::LK_Cpp ||
3908        Style.Language == FormatStyle::LK_ObjC) &&
3909       Left.is(tok::l_paren) && Left.BlockParameterCount > 0 &&
3910       !Right.isOneOf(tok::l_paren, TT_LambdaLSquare)) {
3911     // Multiple lambdas in the same function call force line breaks.
3912     if (Left.BlockParameterCount > 1)
3913       return true;
3914 
3915     // A lambda followed by another arg forces a line break.
3916     if (!Left.Role)
3917       return false;
3918     auto Comma = Left.Role->lastComma();
3919     if (!Comma)
3920       return false;
3921     auto Next = Comma->getNextNonComment();
3922     if (!Next)
3923       return false;
3924     if (!Next->isOneOf(TT_LambdaLSquare, tok::l_brace, tok::caret))
3925       return true;
3926   }
3927 
3928   return false;
3929 }
3930 
3931 bool TokenAnnotator::canBreakBefore(const AnnotatedLine &Line,
3932                                     const FormatToken &Right) {
3933   const FormatToken &Left = *Right.Previous;
3934   // Language-specific stuff.
3935   if (Style.isCSharp()) {
3936     if (Left.isOneOf(TT_CSharpNamedArgumentColon, TT_AttributeColon) ||
3937         Right.isOneOf(TT_CSharpNamedArgumentColon, TT_AttributeColon))
3938       return false;
3939     // Only break after commas for generic type constraints.
3940     if (Line.First->is(TT_CSharpGenericTypeConstraint))
3941       return Left.is(TT_CSharpGenericTypeConstraintComma);
3942     // Keep nullable operators attached to their identifiers.
3943     if (Right.is(TT_CSharpNullable)) {
3944       return false;
3945     }
3946   } else if (Style.Language == FormatStyle::LK_Java) {
3947     if (Left.isOneOf(Keywords.kw_throws, Keywords.kw_extends,
3948                      Keywords.kw_implements))
3949       return false;
3950     if (Right.isOneOf(Keywords.kw_throws, Keywords.kw_extends,
3951                       Keywords.kw_implements))
3952       return true;
3953   } else if (Style.Language == FormatStyle::LK_JavaScript) {
3954     const FormatToken *NonComment = Right.getPreviousNonComment();
3955     if (NonComment &&
3956         NonComment->isOneOf(
3957             tok::kw_return, Keywords.kw_yield, tok::kw_continue, tok::kw_break,
3958             tok::kw_throw, Keywords.kw_interface, Keywords.kw_type,
3959             tok::kw_static, tok::kw_public, tok::kw_private, tok::kw_protected,
3960             Keywords.kw_readonly, Keywords.kw_abstract, Keywords.kw_get,
3961             Keywords.kw_set, Keywords.kw_async, Keywords.kw_await))
3962       return false; // Otherwise automatic semicolon insertion would trigger.
3963     if (Right.NestingLevel == 0 &&
3964         (Left.Tok.getIdentifierInfo() ||
3965          Left.isOneOf(tok::r_square, tok::r_paren)) &&
3966         Right.isOneOf(tok::l_square, tok::l_paren))
3967       return false; // Otherwise automatic semicolon insertion would trigger.
3968     if (NonComment && NonComment->is(tok::identifier) &&
3969         NonComment->TokenText == "asserts")
3970       return false;
3971     if (Left.is(TT_FatArrow) && Right.is(tok::l_brace))
3972       return false;
3973     if (Left.is(TT_JsTypeColon))
3974       return true;
3975     // Don't wrap between ":" and "!" of a strict prop init ("field!: type;").
3976     if (Left.is(tok::exclaim) && Right.is(tok::colon))
3977       return false;
3978     // Look for is type annotations like:
3979     // function f(): a is B { ... }
3980     // Do not break before is in these cases.
3981     if (Right.is(Keywords.kw_is)) {
3982       const FormatToken *Next = Right.getNextNonComment();
3983       // If `is` is followed by a colon, it's likely that it's a dict key, so
3984       // ignore it for this check.
3985       // For example this is common in Polymer:
3986       // Polymer({
3987       //   is: 'name',
3988       //   ...
3989       // });
3990       if (!Next || !Next->is(tok::colon))
3991         return false;
3992     }
3993     if (Left.is(Keywords.kw_in))
3994       return Style.BreakBeforeBinaryOperators == FormatStyle::BOS_None;
3995     if (Right.is(Keywords.kw_in))
3996       return Style.BreakBeforeBinaryOperators != FormatStyle::BOS_None;
3997     if (Right.is(Keywords.kw_as))
3998       return false; // must not break before as in 'x as type' casts
3999     if (Right.isOneOf(Keywords.kw_extends, Keywords.kw_infer)) {
4000       // extends and infer can appear as keywords in conditional types:
4001       //   https://www.typescriptlang.org/docs/handbook/release-notes/typescript-2-8.html#conditional-types
4002       // do not break before them, as the expressions are subject to ASI.
4003       return false;
4004     }
4005     if (Left.is(Keywords.kw_as))
4006       return true;
4007     if (Left.is(TT_NonNullAssertion))
4008       return true;
4009     if (Left.is(Keywords.kw_declare) &&
4010         Right.isOneOf(Keywords.kw_module, tok::kw_namespace,
4011                       Keywords.kw_function, tok::kw_class, tok::kw_enum,
4012                       Keywords.kw_interface, Keywords.kw_type, Keywords.kw_var,
4013                       Keywords.kw_let, tok::kw_const))
4014       // See grammar for 'declare' statements at:
4015       // https://github.com/Microsoft/TypeScript/blob/master/doc/spec.md#A.10
4016       return false;
4017     if (Left.isOneOf(Keywords.kw_module, tok::kw_namespace) &&
4018         Right.isOneOf(tok::identifier, tok::string_literal))
4019       return false; // must not break in "module foo { ...}"
4020     if (Right.is(TT_TemplateString) && Right.closesScope())
4021       return false;
4022     // Don't split tagged template literal so there is a break between the tag
4023     // identifier and template string.
4024     if (Left.is(tok::identifier) && Right.is(TT_TemplateString)) {
4025       return false;
4026     }
4027     if (Left.is(TT_TemplateString) && Left.opensScope())
4028       return true;
4029   }
4030 
4031   if (Left.is(tok::at))
4032     return false;
4033   if (Left.Tok.getObjCKeywordID() == tok::objc_interface)
4034     return false;
4035   if (Left.isOneOf(TT_JavaAnnotation, TT_LeadingJavaAnnotation))
4036     return !Right.is(tok::l_paren);
4037   if (Right.is(TT_PointerOrReference))
4038     return Line.IsMultiVariableDeclStmt ||
4039            (getTokenPointerOrReferenceAlignment(Right) ==
4040                 FormatStyle::PAS_Right &&
4041             (!Right.Next || Right.Next->isNot(TT_FunctionDeclarationName)));
4042   if (Right.isOneOf(TT_StartOfName, TT_FunctionDeclarationName) ||
4043       Right.is(tok::kw_operator))
4044     return true;
4045   if (Left.is(TT_PointerOrReference))
4046     return false;
4047   if (Right.isTrailingComment())
4048     // We rely on MustBreakBefore being set correctly here as we should not
4049     // change the "binding" behavior of a comment.
4050     // The first comment in a braced lists is always interpreted as belonging to
4051     // the first list element. Otherwise, it should be placed outside of the
4052     // list.
4053     return Left.is(BK_BracedInit) ||
4054            (Left.is(TT_CtorInitializerColon) &&
4055             Style.BreakConstructorInitializers == FormatStyle::BCIS_AfterColon);
4056   if (Left.is(tok::question) && Right.is(tok::colon))
4057     return false;
4058   if (Right.is(TT_ConditionalExpr) || Right.is(tok::question))
4059     return Style.BreakBeforeTernaryOperators;
4060   if (Left.is(TT_ConditionalExpr) || Left.is(tok::question))
4061     return !Style.BreakBeforeTernaryOperators;
4062   if (Left.is(TT_InheritanceColon))
4063     return Style.BreakInheritanceList == FormatStyle::BILS_AfterColon;
4064   if (Right.is(TT_InheritanceColon))
4065     return Style.BreakInheritanceList != FormatStyle::BILS_AfterColon;
4066   if (Right.is(TT_ObjCMethodExpr) && !Right.is(tok::r_square) &&
4067       Left.isNot(TT_SelectorName))
4068     return true;
4069 
4070   if (Right.is(tok::colon) &&
4071       !Right.isOneOf(TT_CtorInitializerColon, TT_InlineASMColon))
4072     return false;
4073   if (Left.is(tok::colon) && Left.isOneOf(TT_DictLiteral, TT_ObjCMethodExpr)) {
4074     if (Style.Language == FormatStyle::LK_Proto ||
4075         Style.Language == FormatStyle::LK_TextProto) {
4076       if (!Style.AlwaysBreakBeforeMultilineStrings && Right.isStringLiteral())
4077         return false;
4078       // Prevent cases like:
4079       //
4080       // submessage:
4081       //     { key: valueeeeeeeeeeee }
4082       //
4083       // when the snippet does not fit into one line.
4084       // Prefer:
4085       //
4086       // submessage: {
4087       //   key: valueeeeeeeeeeee
4088       // }
4089       //
4090       // instead, even if it is longer by one line.
4091       //
4092       // Note that this allows allows the "{" to go over the column limit
4093       // when the column limit is just between ":" and "{", but that does
4094       // not happen too often and alternative formattings in this case are
4095       // not much better.
4096       //
4097       // The code covers the cases:
4098       //
4099       // submessage: { ... }
4100       // submessage: < ... >
4101       // repeated: [ ... ]
4102       if (((Right.is(tok::l_brace) || Right.is(tok::less)) &&
4103            Right.is(TT_DictLiteral)) ||
4104           Right.is(TT_ArrayInitializerLSquare))
4105         return false;
4106     }
4107     return true;
4108   }
4109   if (Right.is(tok::r_square) && Right.MatchingParen &&
4110       Right.MatchingParen->is(TT_ProtoExtensionLSquare))
4111     return false;
4112   if (Right.is(TT_SelectorName) || (Right.is(tok::identifier) && Right.Next &&
4113                                     Right.Next->is(TT_ObjCMethodExpr)))
4114     return Left.isNot(tok::period); // FIXME: Properly parse ObjC calls.
4115   if (Left.is(tok::r_paren) && Line.Type == LT_ObjCProperty)
4116     return true;
4117   if (Left.ClosesTemplateDeclaration || Left.is(TT_FunctionAnnotationRParen))
4118     return true;
4119   if (Right.isOneOf(TT_RangeBasedForLoopColon, TT_OverloadedOperatorLParen,
4120                     TT_OverloadedOperator))
4121     return false;
4122   if (Left.is(TT_RangeBasedForLoopColon))
4123     return true;
4124   if (Right.is(TT_RangeBasedForLoopColon))
4125     return false;
4126   if (Left.is(TT_TemplateCloser) && Right.is(TT_TemplateOpener))
4127     return true;
4128   if (Left.isOneOf(TT_TemplateCloser, TT_UnaryOperator) ||
4129       Left.is(tok::kw_operator))
4130     return false;
4131   if (Left.is(tok::equal) && !Right.isOneOf(tok::kw_default, tok::kw_delete) &&
4132       Line.Type == LT_VirtualFunctionDecl && Left.NestingLevel == 0)
4133     return false;
4134   if (Left.is(tok::equal) && Right.is(tok::l_brace) &&
4135       !Style.Cpp11BracedListStyle)
4136     return false;
4137   if (Left.is(tok::l_paren) &&
4138       Left.isOneOf(TT_AttributeParen, TT_TypeDeclarationParen))
4139     return false;
4140   if (Left.is(tok::l_paren) && Left.Previous &&
4141       (Left.Previous->isOneOf(TT_BinaryOperator, TT_CastRParen)))
4142     return false;
4143   if (Right.is(TT_ImplicitStringLiteral))
4144     return false;
4145 
4146   if (Right.is(tok::r_paren) || Right.is(TT_TemplateCloser))
4147     return false;
4148   if (Right.is(tok::r_square) && Right.MatchingParen &&
4149       Right.MatchingParen->is(TT_LambdaLSquare))
4150     return false;
4151 
4152   // We only break before r_brace if there was a corresponding break before
4153   // the l_brace, which is tracked by BreakBeforeClosingBrace.
4154   if (Right.is(tok::r_brace))
4155     return Right.MatchingParen && Right.MatchingParen->is(BK_Block);
4156 
4157   // Allow breaking after a trailing annotation, e.g. after a method
4158   // declaration.
4159   if (Left.is(TT_TrailingAnnotation))
4160     return !Right.isOneOf(tok::l_brace, tok::semi, tok::equal, tok::l_paren,
4161                           tok::less, tok::coloncolon);
4162 
4163   if (Right.is(tok::kw___attribute) ||
4164       (Right.is(tok::l_square) && Right.is(TT_AttributeSquare)))
4165     return !Left.is(TT_AttributeSquare);
4166 
4167   if (Left.is(tok::identifier) && Right.is(tok::string_literal))
4168     return true;
4169 
4170   if (Right.is(tok::identifier) && Right.Next && Right.Next->is(TT_DictLiteral))
4171     return true;
4172 
4173   if (Left.is(TT_CtorInitializerColon))
4174     return Style.BreakConstructorInitializers == FormatStyle::BCIS_AfterColon;
4175   if (Right.is(TT_CtorInitializerColon))
4176     return Style.BreakConstructorInitializers != FormatStyle::BCIS_AfterColon;
4177   if (Left.is(TT_CtorInitializerComma) &&
4178       Style.BreakConstructorInitializers == FormatStyle::BCIS_BeforeComma)
4179     return false;
4180   if (Right.is(TT_CtorInitializerComma) &&
4181       Style.BreakConstructorInitializers == FormatStyle::BCIS_BeforeComma)
4182     return true;
4183   if (Left.is(TT_InheritanceComma) &&
4184       Style.BreakInheritanceList == FormatStyle::BILS_BeforeComma)
4185     return false;
4186   if (Right.is(TT_InheritanceComma) &&
4187       Style.BreakInheritanceList == FormatStyle::BILS_BeforeComma)
4188     return true;
4189   if ((Left.is(tok::greater) && Right.is(tok::greater)) ||
4190       (Left.is(tok::less) && Right.is(tok::less)))
4191     return false;
4192   if (Right.is(TT_BinaryOperator) &&
4193       Style.BreakBeforeBinaryOperators != FormatStyle::BOS_None &&
4194       (Style.BreakBeforeBinaryOperators == FormatStyle::BOS_All ||
4195        Right.getPrecedence() != prec::Assignment))
4196     return true;
4197   if (Left.is(TT_ArrayInitializerLSquare))
4198     return true;
4199   if (Right.is(tok::kw_typename) && Left.isNot(tok::kw_const))
4200     return true;
4201   if ((Left.isBinaryOperator() || Left.is(TT_BinaryOperator)) &&
4202       !Left.isOneOf(tok::arrowstar, tok::lessless) &&
4203       Style.BreakBeforeBinaryOperators != FormatStyle::BOS_All &&
4204       (Style.BreakBeforeBinaryOperators == FormatStyle::BOS_None ||
4205        Left.getPrecedence() == prec::Assignment))
4206     return true;
4207   if ((Left.is(TT_AttributeSquare) && Right.is(tok::l_square)) ||
4208       (Left.is(tok::r_square) && Right.is(TT_AttributeSquare)))
4209     return false;
4210 
4211   auto ShortLambdaOption = Style.AllowShortLambdasOnASingleLine;
4212   if (Style.BraceWrapping.BeforeLambdaBody) {
4213     if (isAllmanLambdaBrace(Left))
4214       return !isItAnEmptyLambdaAllowed(Left, ShortLambdaOption);
4215     if (isAllmanLambdaBrace(Right))
4216       return !isItAnEmptyLambdaAllowed(Right, ShortLambdaOption);
4217   }
4218 
4219   return Left.isOneOf(tok::comma, tok::coloncolon, tok::semi, tok::l_brace,
4220                       tok::kw_class, tok::kw_struct, tok::comment) ||
4221          Right.isMemberAccess() ||
4222          Right.isOneOf(TT_TrailingReturnArrow, TT_LambdaArrow, tok::lessless,
4223                        tok::colon, tok::l_square, tok::at) ||
4224          (Style.BraceWrapping.BeforeLambdaBody && Right.is(TT_LambdaLBrace)) ||
4225          (Left.is(tok::r_paren) &&
4226           Right.isOneOf(tok::identifier, tok::kw_const)) ||
4227          (Left.is(tok::l_paren) && !Right.is(tok::r_paren)) ||
4228          (Left.is(TT_TemplateOpener) && !Right.is(TT_TemplateCloser));
4229 }
4230 
4231 void TokenAnnotator::printDebugInfo(const AnnotatedLine &Line) {
4232   llvm::errs() << "AnnotatedTokens(L=" << Line.Level << "):\n";
4233   const FormatToken *Tok = Line.First;
4234   while (Tok) {
4235     llvm::errs() << " M=" << Tok->MustBreakBefore
4236                  << " C=" << Tok->CanBreakBefore
4237                  << " T=" << getTokenTypeName(Tok->getType())
4238                  << " S=" << Tok->SpacesRequiredBefore
4239                  << " F=" << Tok->Finalized << " B=" << Tok->BlockParameterCount
4240                  << " BK=" << Tok->getBlockKind() << " P=" << Tok->SplitPenalty
4241                  << " Name=" << Tok->Tok.getName() << " L=" << Tok->TotalLength
4242                  << " PPK=" << Tok->getPackingKind() << " FakeLParens=";
4243     for (unsigned i = 0, e = Tok->FakeLParens.size(); i != e; ++i)
4244       llvm::errs() << Tok->FakeLParens[i] << "/";
4245     llvm::errs() << " FakeRParens=" << Tok->FakeRParens;
4246     llvm::errs() << " II=" << Tok->Tok.getIdentifierInfo();
4247     llvm::errs() << " Text='" << Tok->TokenText << "'\n";
4248     if (!Tok->Next)
4249       assert(Tok == Line.Last);
4250     Tok = Tok->Next;
4251   }
4252   llvm::errs() << "----\n";
4253 }
4254 
4255 FormatStyle::PointerAlignmentStyle
4256 TokenAnnotator::getTokenReferenceAlignment(const FormatToken &Reference) {
4257   assert(Reference.isOneOf(tok::amp, tok::ampamp));
4258   switch (Style.ReferenceAlignment) {
4259   case FormatStyle::RAS_Pointer:
4260     return Style.PointerAlignment;
4261   case FormatStyle::RAS_Left:
4262     return FormatStyle::PAS_Left;
4263   case FormatStyle::RAS_Right:
4264     return FormatStyle::PAS_Right;
4265   case FormatStyle::RAS_Middle:
4266     return FormatStyle::PAS_Middle;
4267   }
4268   assert(0); //"Unhandled value of ReferenceAlignment"
4269   return Style.PointerAlignment;
4270 }
4271 
4272 FormatStyle::PointerAlignmentStyle
4273 TokenAnnotator::getTokenPointerOrReferenceAlignment(
4274     const FormatToken &PointerOrReference) {
4275   if (PointerOrReference.isOneOf(tok::amp, tok::ampamp)) {
4276     switch (Style.ReferenceAlignment) {
4277     case FormatStyle::RAS_Pointer:
4278       return Style.PointerAlignment;
4279     case FormatStyle::RAS_Left:
4280       return FormatStyle::PAS_Left;
4281     case FormatStyle::RAS_Right:
4282       return FormatStyle::PAS_Right;
4283     case FormatStyle::RAS_Middle:
4284       return FormatStyle::PAS_Middle;
4285     }
4286   }
4287   assert(PointerOrReference.is(tok::star));
4288   return Style.PointerAlignment;
4289 }
4290 
4291 } // namespace format
4292 } // namespace clang
4293