1//===--- TokenAnnotator.cpp - Format C++ code -----------------------------===//
2//
3//                     The LLVM Compiler Infrastructure
4//
5// This file is distributed under the University of Illinois Open Source
6// License. See LICENSE.TXT for details.
7//
8//===----------------------------------------------------------------------===//
9///
10/// \file
11/// \brief This file implements a token annotator, i.e. creates
12/// \c AnnotatedTokens out of \c FormatTokens with required extra information.
13///
14//===----------------------------------------------------------------------===//
15
16#include "TokenAnnotator.h"
17#include "clang/Basic/SourceManager.h"
18#include "llvm/Support/Debug.h"
19
20#define DEBUG_TYPE "format-token-annotator"
21
22namespace clang {
23namespace format {
24
25namespace {
26
27/// \brief A parser that gathers additional information about tokens.
28///
29/// The \c TokenAnnotator tries to match parenthesis and square brakets and
30/// store a parenthesis levels. It also tries to resolve matching "<" and ">"
31/// into template parameter lists.
32class AnnotatingParser {
33public:
34  AnnotatingParser(const FormatStyle &Style, AnnotatedLine &Line,
35                   IdentifierInfo &Ident_in)
36      : Style(Style), Line(Line), CurrentToken(Line.First),
37        KeywordVirtualFound(false), AutoFound(false), Ident_in(Ident_in) {
38    Contexts.push_back(Context(tok::unknown, 1, /*IsExpression=*/false));
39    resetTokenMetadata(CurrentToken);
40  }
41
42private:
43  bool parseAngle() {
44    if (!CurrentToken)
45      return false;
46    ScopedContextCreator ContextCreator(*this, tok::less, 10);
47    FormatToken *Left = CurrentToken->Previous;
48    Contexts.back().IsExpression = false;
49    // If there's a template keyword before the opening angle bracket, this is a
50    // template parameter, not an argument.
51    Contexts.back().InTemplateArgument =
52        Left->Previous && Left->Previous->Tok.isNot(tok::kw_template);
53
54    while (CurrentToken) {
55      if (CurrentToken->is(tok::greater)) {
56        Left->MatchingParen = CurrentToken;
57        CurrentToken->MatchingParen = Left;
58        CurrentToken->Type = TT_TemplateCloser;
59        next();
60        return true;
61      }
62      if (CurrentToken->isOneOf(tok::r_paren, tok::r_square, tok::r_brace,
63                                tok::question, tok::colon))
64        return false;
65      // If a && or || is found and interpreted as a binary operator, this set
66      // of angles is likely part of something like "a < b && c > d". If the
67      // angles are inside an expression, the ||/&& might also be a binary
68      // operator that was misinterpreted because we are parsing template
69      // parameters.
70      // FIXME: This is getting out of hand, write a decent parser.
71      if (CurrentToken->Previous->isOneOf(tok::pipepipe, tok::ampamp) &&
72          ((CurrentToken->Previous->Type == TT_BinaryOperator &&
73            // Toplevel bool expressions do not make lots of sense;
74            // If we're on the top level, it contains only the base context and
75            // the context for the current opening angle bracket.
76            Contexts.size() > 2) ||
77           Contexts[Contexts.size() - 2].IsExpression) &&
78          Line.First->isNot(tok::kw_template))
79        return false;
80      updateParameterCount(Left, CurrentToken);
81      if (!consumeToken())
82        return false;
83    }
84    return false;
85  }
86
87  bool parseParens(bool LookForDecls = false) {
88    if (!CurrentToken)
89      return false;
90    ScopedContextCreator ContextCreator(*this, tok::l_paren, 1);
91
92    // FIXME: This is a bit of a hack. Do better.
93    Contexts.back().ColonIsForRangeExpr =
94        Contexts.size() == 2 && Contexts[0].ColonIsForRangeExpr;
95
96    bool StartsObjCMethodExpr = false;
97    FormatToken *Left = CurrentToken->Previous;
98    if (CurrentToken->is(tok::caret)) {
99      // (^ can start a block type.
100      Left->Type = TT_ObjCBlockLParen;
101    } else if (FormatToken *MaybeSel = Left->Previous) {
102      // @selector( starts a selector.
103      if (MaybeSel->isObjCAtKeyword(tok::objc_selector) && MaybeSel->Previous &&
104          MaybeSel->Previous->is(tok::at)) {
105        StartsObjCMethodExpr = true;
106      }
107    }
108
109    if (Left->Previous &&
110        (Left->Previous->isOneOf(tok::kw_static_assert, tok::kw_if,
111                                 tok::kw_while, tok::l_paren, tok::comma) ||
112         Left->Previous->Type == TT_BinaryOperator)) {
113      // static_assert, if and while usually contain expressions.
114      Contexts.back().IsExpression = true;
115    } else if (Line.InPPDirective &&
116               (!Left->Previous ||
117                (Left->Previous->isNot(tok::identifier) &&
118                 Left->Previous->Type != TT_OverloadedOperator))) {
119      Contexts.back().IsExpression = true;
120    } else if (Left->Previous && Left->Previous->is(tok::r_square) &&
121               Left->Previous->MatchingParen &&
122               Left->Previous->MatchingParen->Type == TT_LambdaLSquare) {
123      // This is a parameter list of a lambda expression.
124      Contexts.back().IsExpression = false;
125    } else if (Contexts[Contexts.size() - 2].CaretFound) {
126      // This is the parameter list of an ObjC block.
127      Contexts.back().IsExpression = false;
128    } else if (Left->Previous && Left->Previous->is(tok::kw___attribute)) {
129      Left->Type = TT_AttributeParen;
130    } else if (Left->Previous && Left->Previous->IsForEachMacro) {
131      // The first argument to a foreach macro is a declaration.
132      Contexts.back().IsForEachMacro = true;
133      Contexts.back().IsExpression = false;
134    }
135
136    if (StartsObjCMethodExpr) {
137      Contexts.back().ColonIsObjCMethodExpr = true;
138      Left->Type = TT_ObjCMethodExpr;
139    }
140
141    bool MightBeFunctionType = CurrentToken->is(tok::star);
142    bool HasMultipleLines = false;
143    bool HasMultipleParametersOnALine = false;
144    while (CurrentToken) {
145      // LookForDecls is set when "if (" has been seen. Check for
146      // 'identifier' '*' 'identifier' followed by not '=' -- this
147      // '*' has to be a binary operator but determineStarAmpUsage() will
148      // categorize it as an unary operator, so set the right type here.
149      if (LookForDecls && CurrentToken->Next) {
150        FormatToken *Prev = CurrentToken->getPreviousNonComment();
151        if (Prev) {
152          FormatToken *PrevPrev = Prev->getPreviousNonComment();
153          FormatToken *Next = CurrentToken->Next;
154          if (PrevPrev && PrevPrev->is(tok::identifier) &&
155              Prev->isOneOf(tok::star, tok::amp, tok::ampamp) &&
156              CurrentToken->is(tok::identifier) && Next->isNot(tok::equal)) {
157            Prev->Type = TT_BinaryOperator;
158            LookForDecls = false;
159          }
160        }
161      }
162
163      if (CurrentToken->Previous->Type == TT_PointerOrReference &&
164          CurrentToken->Previous->Previous->isOneOf(tok::l_paren,
165                                                    tok::coloncolon))
166        MightBeFunctionType = true;
167      if (CurrentToken->Previous->Type == TT_BinaryOperator)
168        Contexts.back().IsExpression = true;
169      if (CurrentToken->is(tok::r_paren)) {
170        if (MightBeFunctionType && CurrentToken->Next &&
171            (CurrentToken->Next->is(tok::l_paren) ||
172             (CurrentToken->Next->is(tok::l_square) &&
173              !Contexts.back().IsExpression)))
174          Left->Type = TT_FunctionTypeLParen;
175        Left->MatchingParen = CurrentToken;
176        CurrentToken->MatchingParen = Left;
177
178        if (StartsObjCMethodExpr) {
179          CurrentToken->Type = TT_ObjCMethodExpr;
180          if (Contexts.back().FirstObjCSelectorName) {
181            Contexts.back().FirstObjCSelectorName->LongestObjCSelectorName =
182                Contexts.back().LongestObjCSelectorName;
183          }
184        }
185
186        if (Left->Type == TT_AttributeParen)
187          CurrentToken->Type = TT_AttributeParen;
188
189        if (!HasMultipleLines)
190          Left->PackingKind = PPK_Inconclusive;
191        else if (HasMultipleParametersOnALine)
192          Left->PackingKind = PPK_BinPacked;
193        else
194          Left->PackingKind = PPK_OnePerLine;
195
196        next();
197        return true;
198      }
199      if (CurrentToken->isOneOf(tok::r_square, tok::r_brace))
200        return false;
201      else if (CurrentToken->is(tok::l_brace))
202        Left->Type = TT_Unknown; // Not TT_ObjCBlockLParen
203      if (CurrentToken->is(tok::comma) && CurrentToken->Next &&
204          !CurrentToken->Next->HasUnescapedNewline &&
205          !CurrentToken->Next->isTrailingComment())
206        HasMultipleParametersOnALine = true;
207      if (CurrentToken->isOneOf(tok::kw_const, tok::kw_auto) ||
208          CurrentToken->isSimpleTypeSpecifier())
209        Contexts.back().IsExpression = false;
210      FormatToken *Tok = CurrentToken;
211      if (!consumeToken())
212        return false;
213      updateParameterCount(Left, Tok);
214      if (CurrentToken && CurrentToken->HasUnescapedNewline)
215        HasMultipleLines = true;
216    }
217    return false;
218  }
219
220  bool parseSquare() {
221    if (!CurrentToken)
222      return false;
223
224    // A '[' could be an index subscript (after an identifier or after
225    // ')' or ']'), it could be the start of an Objective-C method
226    // expression, or it could the the start of an Objective-C array literal.
227    FormatToken *Left = CurrentToken->Previous;
228    FormatToken *Parent = Left->getPreviousNonComment();
229    bool StartsObjCMethodExpr =
230        Contexts.back().CanBeExpression && Left->Type != TT_LambdaLSquare &&
231        CurrentToken->isNot(tok::l_brace) &&
232        (!Parent || Parent->isOneOf(tok::colon, tok::l_square, tok::l_paren,
233                                    tok::kw_return, tok::kw_throw) ||
234         Parent->isUnaryOperator() || Parent->Type == TT_ObjCForIn ||
235         Parent->Type == TT_CastRParen ||
236         getBinOpPrecedence(Parent->Tok.getKind(), true, true) > prec::Unknown);
237    ScopedContextCreator ContextCreator(*this, tok::l_square, 10);
238    Contexts.back().IsExpression = true;
239    bool ColonFound = false;
240
241    if (StartsObjCMethodExpr) {
242      Contexts.back().ColonIsObjCMethodExpr = true;
243      Left->Type = TT_ObjCMethodExpr;
244    } else if (Parent && Parent->is(tok::at)) {
245      Left->Type = TT_ArrayInitializerLSquare;
246    } else if (Left->Type == TT_Unknown) {
247      Left->Type = TT_ArraySubscriptLSquare;
248    }
249
250    while (CurrentToken) {
251      if (CurrentToken->is(tok::r_square)) {
252        if (CurrentToken->Next && CurrentToken->Next->is(tok::l_paren) &&
253            Left->Type == TT_ObjCMethodExpr) {
254          // An ObjC method call is rarely followed by an open parenthesis.
255          // FIXME: Do we incorrectly label ":" with this?
256          StartsObjCMethodExpr = false;
257          Left->Type = TT_Unknown;
258        }
259        if (StartsObjCMethodExpr && CurrentToken->Previous != Left) {
260          CurrentToken->Type = TT_ObjCMethodExpr;
261          // determineStarAmpUsage() thinks that '*' '[' is allocating an
262          // array of pointers, but if '[' starts a selector then '*' is a
263          // binary operator.
264          if (Parent && Parent->Type == TT_PointerOrReference)
265            Parent->Type = TT_BinaryOperator;
266        }
267        Left->MatchingParen = CurrentToken;
268        CurrentToken->MatchingParen = Left;
269        if (Contexts.back().FirstObjCSelectorName) {
270          Contexts.back().FirstObjCSelectorName->LongestObjCSelectorName =
271              Contexts.back().LongestObjCSelectorName;
272          if (Left->BlockParameterCount > 1)
273            Contexts.back().FirstObjCSelectorName->LongestObjCSelectorName = 0;
274        }
275        next();
276        return true;
277      }
278      if (CurrentToken->isOneOf(tok::r_paren, tok::r_brace))
279        return false;
280      if (CurrentToken->is(tok::colon))
281        ColonFound = true;
282      if (CurrentToken->is(tok::comma) &&
283          Style.Language != FormatStyle::LK_Proto &&
284          (Left->Type == TT_ArraySubscriptLSquare ||
285           (Left->Type == TT_ObjCMethodExpr && !ColonFound)))
286        Left->Type = TT_ArrayInitializerLSquare;
287      FormatToken* Tok = CurrentToken;
288      if (!consumeToken())
289        return false;
290      updateParameterCount(Left, Tok);
291    }
292    return false;
293  }
294
295  bool parseBrace() {
296    if (CurrentToken) {
297      FormatToken *Left = CurrentToken->Previous;
298
299      if (Contexts.back().CaretFound)
300        Left->Type = TT_ObjCBlockLBrace;
301      Contexts.back().CaretFound = false;
302
303      ScopedContextCreator ContextCreator(*this, tok::l_brace, 1);
304      Contexts.back().ColonIsDictLiteral = true;
305      if (Left->BlockKind == BK_BracedInit)
306        Contexts.back().IsExpression = true;
307
308      while (CurrentToken) {
309        if (CurrentToken->is(tok::r_brace)) {
310          Left->MatchingParen = CurrentToken;
311          CurrentToken->MatchingParen = Left;
312          next();
313          return true;
314        }
315        if (CurrentToken->isOneOf(tok::r_paren, tok::r_square))
316          return false;
317        updateParameterCount(Left, CurrentToken);
318        if (CurrentToken->is(tok::colon) &&
319            Style.Language != FormatStyle::LK_Proto) {
320          if (CurrentToken->getPreviousNonComment()->is(tok::identifier))
321            CurrentToken->getPreviousNonComment()->Type = TT_SelectorName;
322          Left->Type = TT_DictLiteral;
323        }
324        if (!consumeToken())
325          return false;
326      }
327    }
328    return true;
329  }
330
331  void updateParameterCount(FormatToken *Left, FormatToken *Current) {
332    if (Current->Type == TT_LambdaLSquare ||
333        (Current->is(tok::caret) && Current->Type == TT_UnaryOperator) ||
334        (Style.Language == FormatStyle::LK_JavaScript &&
335         Current->TokenText == "function")) {
336      ++Left->BlockParameterCount;
337    }
338    if (Current->is(tok::comma)) {
339      ++Left->ParameterCount;
340      if (!Left->Role)
341        Left->Role.reset(new CommaSeparatedList(Style));
342      Left->Role->CommaFound(Current);
343    } else if (Left->ParameterCount == 0 && Current->isNot(tok::comment)) {
344      Left->ParameterCount = 1;
345    }
346  }
347
348  bool parseConditional() {
349    while (CurrentToken) {
350      if (CurrentToken->is(tok::colon)) {
351        CurrentToken->Type = TT_ConditionalExpr;
352        next();
353        return true;
354      }
355      if (!consumeToken())
356        return false;
357    }
358    return false;
359  }
360
361  bool parseTemplateDeclaration() {
362    if (CurrentToken && CurrentToken->is(tok::less)) {
363      CurrentToken->Type = TT_TemplateOpener;
364      next();
365      if (!parseAngle())
366        return false;
367      if (CurrentToken)
368        CurrentToken->Previous->ClosesTemplateDeclaration = true;
369      return true;
370    }
371    return false;
372  }
373
374  bool consumeToken() {
375    FormatToken *Tok = CurrentToken;
376    next();
377    switch (Tok->Tok.getKind()) {
378    case tok::plus:
379    case tok::minus:
380      if (!Tok->Previous && Line.MustBeDeclaration)
381        Tok->Type = TT_ObjCMethodSpecifier;
382      break;
383    case tok::colon:
384      if (!Tok->Previous)
385        return false;
386      // Colons from ?: are handled in parseConditional().
387      if (Tok->Previous->is(tok::r_paren) && Contexts.size() == 1 &&
388          Line.First->isNot(tok::kw_case)) {
389        Tok->Type = TT_CtorInitializerColon;
390      } else if (Contexts.back().ColonIsDictLiteral) {
391        Tok->Type = TT_DictLiteral;
392      } else if (Contexts.back().ColonIsObjCMethodExpr ||
393                 Line.First->Type == TT_ObjCMethodSpecifier) {
394        Tok->Type = TT_ObjCMethodExpr;
395        Tok->Previous->Type = TT_SelectorName;
396        if (Tok->Previous->ColumnWidth >
397            Contexts.back().LongestObjCSelectorName) {
398          Contexts.back().LongestObjCSelectorName = Tok->Previous->ColumnWidth;
399        }
400        if (!Contexts.back().FirstObjCSelectorName)
401          Contexts.back().FirstObjCSelectorName = Tok->Previous;
402      } else if (Contexts.back().ColonIsForRangeExpr) {
403        Tok->Type = TT_RangeBasedForLoopColon;
404      } else if (CurrentToken && CurrentToken->is(tok::numeric_constant)) {
405        Tok->Type = TT_BitFieldColon;
406      } else if (Contexts.size() == 1 &&
407                 !Line.First->isOneOf(tok::kw_enum, tok::kw_case)) {
408        Tok->Type = TT_InheritanceColon;
409      } else if (Contexts.back().ContextKind == tok::l_paren) {
410        Tok->Type = TT_InlineASMColon;
411      }
412      break;
413    case tok::kw_if:
414    case tok::kw_while:
415      if (CurrentToken && CurrentToken->is(tok::l_paren)) {
416        next();
417        if (!parseParens(/*LookForDecls=*/true))
418          return false;
419      }
420      break;
421    case tok::kw_for:
422      Contexts.back().ColonIsForRangeExpr = true;
423      next();
424      if (!parseParens())
425        return false;
426      break;
427    case tok::l_paren:
428      if (!parseParens())
429        return false;
430      if (Line.MustBeDeclaration && Contexts.size() == 1 &&
431          !Contexts.back().IsExpression &&
432          Line.First->Type != TT_ObjCProperty &&
433          (!Tok->Previous || Tok->Previous->isNot(tok::kw_decltype)))
434        Line.MightBeFunctionDecl = true;
435      break;
436    case tok::l_square:
437      if (!parseSquare())
438        return false;
439      break;
440    case tok::l_brace:
441      if (!parseBrace())
442        return false;
443      break;
444    case tok::less:
445      if (Tok->Previous && !Tok->Previous->Tok.isLiteral() && parseAngle())
446        Tok->Type = TT_TemplateOpener;
447      else {
448        Tok->Type = TT_BinaryOperator;
449        CurrentToken = Tok;
450        next();
451      }
452      break;
453    case tok::r_paren:
454    case tok::r_square:
455      return false;
456    case tok::r_brace:
457      // Lines can start with '}'.
458      if (Tok->Previous)
459        return false;
460      break;
461    case tok::greater:
462      Tok->Type = TT_BinaryOperator;
463      break;
464    case tok::kw_operator:
465      while (CurrentToken &&
466             !CurrentToken->isOneOf(tok::l_paren, tok::semi, tok::r_paren)) {
467        if (CurrentToken->isOneOf(tok::star, tok::amp))
468          CurrentToken->Type = TT_PointerOrReference;
469        consumeToken();
470        if (CurrentToken && CurrentToken->Previous->Type == TT_BinaryOperator)
471          CurrentToken->Previous->Type = TT_OverloadedOperator;
472      }
473      if (CurrentToken) {
474        CurrentToken->Type = TT_OverloadedOperatorLParen;
475        if (CurrentToken->Previous->Type == TT_BinaryOperator)
476          CurrentToken->Previous->Type = TT_OverloadedOperator;
477      }
478      break;
479    case tok::question:
480      parseConditional();
481      break;
482    case tok::kw_template:
483      parseTemplateDeclaration();
484      break;
485    case tok::identifier:
486      if (Line.First->is(tok::kw_for) &&
487          Tok->Tok.getIdentifierInfo() == &Ident_in)
488        Tok->Type = TT_ObjCForIn;
489      break;
490    case tok::comma:
491      if (Contexts.back().FirstStartOfName)
492        Contexts.back().FirstStartOfName->PartOfMultiVariableDeclStmt = true;
493      if (Contexts.back().InCtorInitializer)
494        Tok->Type = TT_CtorInitializerComma;
495      if (Contexts.back().IsForEachMacro)
496        Contexts.back().IsExpression = true;
497      break;
498    default:
499      break;
500    }
501    return true;
502  }
503
504  void parseIncludeDirective() {
505    next();
506    if (CurrentToken && CurrentToken->is(tok::less)) {
507      next();
508      while (CurrentToken) {
509        if (CurrentToken->isNot(tok::comment) || CurrentToken->Next)
510          CurrentToken->Type = TT_ImplicitStringLiteral;
511        next();
512      }
513    } else {
514      while (CurrentToken) {
515        if (CurrentToken->is(tok::string_literal))
516          // Mark these string literals as "implicit" literals, too, so that
517          // they are not split or line-wrapped.
518          CurrentToken->Type = TT_ImplicitStringLiteral;
519        next();
520      }
521    }
522  }
523
524  void parseWarningOrError() {
525    next();
526    // We still want to format the whitespace left of the first token of the
527    // warning or error.
528    next();
529    while (CurrentToken) {
530      CurrentToken->Type = TT_ImplicitStringLiteral;
531      next();
532    }
533  }
534
535  void parsePragma() {
536    next(); // Consume "pragma".
537    if (CurrentToken && CurrentToken->TokenText == "mark") {
538      next(); // Consume "mark".
539      next(); // Consume first token (so we fix leading whitespace).
540      while (CurrentToken) {
541        CurrentToken->Type = TT_ImplicitStringLiteral;
542        next();
543      }
544    }
545  }
546
547  void parsePreprocessorDirective() {
548    next();
549    if (!CurrentToken)
550      return;
551    if (CurrentToken->Tok.is(tok::numeric_constant)) {
552      CurrentToken->SpacesRequiredBefore = 1;
553      return;
554    }
555    // Hashes in the middle of a line can lead to any strange token
556    // sequence.
557    if (!CurrentToken->Tok.getIdentifierInfo())
558      return;
559    switch (CurrentToken->Tok.getIdentifierInfo()->getPPKeywordID()) {
560    case tok::pp_include:
561    case tok::pp_import:
562      parseIncludeDirective();
563      break;
564    case tok::pp_error:
565    case tok::pp_warning:
566      parseWarningOrError();
567      break;
568    case tok::pp_pragma:
569      parsePragma();
570      break;
571    case tok::pp_if:
572    case tok::pp_elif:
573      Contexts.back().IsExpression = true;
574      parseLine();
575      break;
576    default:
577      break;
578    }
579    while (CurrentToken)
580      next();
581  }
582
583public:
584  LineType parseLine() {
585    if (CurrentToken->is(tok::hash)) {
586      parsePreprocessorDirective();
587      return LT_PreprocessorDirective;
588    }
589
590    // Directly allow to 'import <string-literal>' to support protocol buffer
591    // definitions (code.google.com/p/protobuf) or missing "#" (either way we
592    // should not break the line).
593    IdentifierInfo *Info = CurrentToken->Tok.getIdentifierInfo();
594    if (Info && Info->getPPKeywordID() == tok::pp_import &&
595        CurrentToken->Next && CurrentToken->Next->is(tok::string_literal))
596      parseIncludeDirective();
597
598    while (CurrentToken) {
599      if (CurrentToken->is(tok::kw_virtual))
600        KeywordVirtualFound = true;
601      if (!consumeToken())
602        return LT_Invalid;
603    }
604    if (KeywordVirtualFound)
605      return LT_VirtualFunctionDecl;
606
607    if (Line.First->Type == TT_ObjCMethodSpecifier) {
608      if (Contexts.back().FirstObjCSelectorName)
609        Contexts.back().FirstObjCSelectorName->LongestObjCSelectorName =
610            Contexts.back().LongestObjCSelectorName;
611      return LT_ObjCMethodDecl;
612    }
613
614    return LT_Other;
615  }
616
617private:
618  void resetTokenMetadata(FormatToken *Token) {
619    if (!Token)
620      return;
621
622    // Reset token type in case we have already looked at it and then
623    // recovered from an error (e.g. failure to find the matching >).
624    if (CurrentToken->Type != TT_LambdaLSquare &&
625        CurrentToken->Type != TT_FunctionLBrace &&
626        CurrentToken->Type != TT_ImplicitStringLiteral &&
627        CurrentToken->Type != TT_RegexLiteral &&
628        CurrentToken->Type != TT_TrailingReturnArrow)
629      CurrentToken->Type = TT_Unknown;
630    if (CurrentToken->Role)
631      CurrentToken->Role.reset(nullptr);
632    CurrentToken->FakeLParens.clear();
633    CurrentToken->FakeRParens = 0;
634  }
635
636  void next() {
637    if (CurrentToken) {
638      determineTokenType(*CurrentToken);
639      CurrentToken->BindingStrength = Contexts.back().BindingStrength;
640      CurrentToken->NestingLevel = Contexts.size() - 1;
641      CurrentToken = CurrentToken->Next;
642    }
643
644    resetTokenMetadata(CurrentToken);
645  }
646
647  /// \brief A struct to hold information valid in a specific context, e.g.
648  /// a pair of parenthesis.
649  struct Context {
650    Context(tok::TokenKind ContextKind, unsigned BindingStrength,
651            bool IsExpression)
652        : ContextKind(ContextKind), BindingStrength(BindingStrength),
653          LongestObjCSelectorName(0), ColonIsForRangeExpr(false),
654          ColonIsDictLiteral(false), ColonIsObjCMethodExpr(false),
655          FirstObjCSelectorName(nullptr), FirstStartOfName(nullptr),
656          IsExpression(IsExpression), CanBeExpression(true),
657          InTemplateArgument(false), InCtorInitializer(false),
658          CaretFound(false), IsForEachMacro(false) {}
659
660    tok::TokenKind ContextKind;
661    unsigned BindingStrength;
662    unsigned LongestObjCSelectorName;
663    bool ColonIsForRangeExpr;
664    bool ColonIsDictLiteral;
665    bool ColonIsObjCMethodExpr;
666    FormatToken *FirstObjCSelectorName;
667    FormatToken *FirstStartOfName;
668    bool IsExpression;
669    bool CanBeExpression;
670    bool InTemplateArgument;
671    bool InCtorInitializer;
672    bool CaretFound;
673    bool IsForEachMacro;
674  };
675
676  /// \brief Puts a new \c Context onto the stack \c Contexts for the lifetime
677  /// of each instance.
678  struct ScopedContextCreator {
679    AnnotatingParser &P;
680
681    ScopedContextCreator(AnnotatingParser &P, tok::TokenKind ContextKind,
682                         unsigned Increase)
683        : P(P) {
684      P.Contexts.push_back(Context(ContextKind,
685                                   P.Contexts.back().BindingStrength + Increase,
686                                   P.Contexts.back().IsExpression));
687    }
688
689    ~ScopedContextCreator() { P.Contexts.pop_back(); }
690  };
691
692  void determineTokenType(FormatToken &Current) {
693    if (Current.getPrecedence() == prec::Assignment &&
694        !Line.First->isOneOf(tok::kw_template, tok::kw_using) &&
695        (!Current.Previous || Current.Previous->isNot(tok::kw_operator))) {
696      Contexts.back().IsExpression = true;
697      for (FormatToken *Previous = Current.Previous;
698           Previous && !Previous->isOneOf(tok::comma, tok::semi);
699           Previous = Previous->Previous) {
700        if (Previous->isOneOf(tok::r_square, tok::r_paren))
701          Previous = Previous->MatchingParen;
702        if (Previous->Type == TT_BinaryOperator &&
703            Previous->isOneOf(tok::star, tok::amp)) {
704          Previous->Type = TT_PointerOrReference;
705        }
706      }
707    } else if (Current.isOneOf(tok::kw_return, tok::kw_throw)) {
708      Contexts.back().IsExpression = true;
709    } else if (Current.is(tok::l_paren) && !Line.MustBeDeclaration &&
710               !Line.InPPDirective &&
711               (!Current.Previous ||
712                Current.Previous->isNot(tok::kw_decltype))) {
713      bool ParametersOfFunctionType =
714          Current.Previous && Current.Previous->is(tok::r_paren) &&
715          Current.Previous->MatchingParen &&
716          Current.Previous->MatchingParen->Type == TT_FunctionTypeLParen;
717      bool IsForOrCatch = Current.Previous &&
718                          Current.Previous->isOneOf(tok::kw_for, tok::kw_catch);
719      Contexts.back().IsExpression = !ParametersOfFunctionType && !IsForOrCatch;
720    } else if (Current.isOneOf(tok::r_paren, tok::greater, tok::comma)) {
721      for (FormatToken *Previous = Current.Previous;
722           Previous && Previous->isOneOf(tok::star, tok::amp);
723           Previous = Previous->Previous)
724        Previous->Type = TT_PointerOrReference;
725    } else if (Current.Previous &&
726               Current.Previous->Type == TT_CtorInitializerColon) {
727      Contexts.back().IsExpression = true;
728      Contexts.back().InCtorInitializer = true;
729    } else if (Current.is(tok::kw_new)) {
730      Contexts.back().CanBeExpression = false;
731    } else if (Current.is(tok::semi) || Current.is(tok::exclaim)) {
732      // This should be the condition or increment in a for-loop.
733      Contexts.back().IsExpression = true;
734    }
735
736    if (Current.Type == TT_Unknown) {
737      // Line.MightBeFunctionDecl can only be true after the parentheses of a
738      // function declaration have been found. In this case, 'Current' is a
739      // trailing token of this declaration and thus cannot be a name.
740      if (isStartOfName(Current) && !Line.MightBeFunctionDecl) {
741        Contexts.back().FirstStartOfName = &Current;
742        Current.Type = TT_StartOfName;
743      } else if (Current.is(tok::kw_auto)) {
744        AutoFound = true;
745      } else if (Current.is(tok::arrow) && AutoFound &&
746                 Line.MustBeDeclaration) {
747        Current.Type = TT_TrailingReturnArrow;
748      } else if (Current.isOneOf(tok::star, tok::amp, tok::ampamp)) {
749        Current.Type =
750            determineStarAmpUsage(Current, Contexts.back().CanBeExpression &&
751                                               Contexts.back().IsExpression,
752                                  Contexts.back().InTemplateArgument);
753      } else if (Current.isOneOf(tok::minus, tok::plus, tok::caret)) {
754        Current.Type = determinePlusMinusCaretUsage(Current);
755        if (Current.Type == TT_UnaryOperator && Current.is(tok::caret))
756          Contexts.back().CaretFound = true;
757      } else if (Current.isOneOf(tok::minusminus, tok::plusplus)) {
758        Current.Type = determineIncrementUsage(Current);
759      } else if (Current.is(tok::exclaim)) {
760        Current.Type = TT_UnaryOperator;
761      } else if (Current.is(tok::question)) {
762        Current.Type = TT_ConditionalExpr;
763      } else if (Current.isBinaryOperator() &&
764                 (!Current.Previous ||
765                  Current.Previous->isNot(tok::l_square))) {
766        Current.Type = TT_BinaryOperator;
767      } else if (Current.is(tok::comment)) {
768        if (Current.TokenText.startswith("//"))
769          Current.Type = TT_LineComment;
770        else
771          Current.Type = TT_BlockComment;
772      } else if (Current.is(tok::r_paren)) {
773        if (rParenEndsCast(Current))
774          Current.Type = TT_CastRParen;
775      } else if (Current.is(tok::at) && Current.Next) {
776        switch (Current.Next->Tok.getObjCKeywordID()) {
777        case tok::objc_interface:
778        case tok::objc_implementation:
779        case tok::objc_protocol:
780          Current.Type = TT_ObjCDecl;
781          break;
782        case tok::objc_property:
783          Current.Type = TT_ObjCProperty;
784          break;
785        default:
786          break;
787        }
788      } else if (Current.is(tok::period)) {
789        FormatToken *PreviousNoComment = Current.getPreviousNonComment();
790        if (PreviousNoComment &&
791            PreviousNoComment->isOneOf(tok::comma, tok::l_brace))
792          Current.Type = TT_DesignatedInitializerPeriod;
793      } else if (Current.isOneOf(tok::identifier, tok::kw_const) &&
794                 Current.Previous && Current.Previous->isNot(tok::equal) &&
795                 Line.MightBeFunctionDecl && Contexts.size() == 1) {
796        // Line.MightBeFunctionDecl can only be true after the parentheses of a
797        // function declaration have been found.
798        Current.Type = TT_TrailingAnnotation;
799      }
800    }
801  }
802
803  /// \brief Take a guess at whether \p Tok starts a name of a function or
804  /// variable declaration.
805  ///
806  /// This is a heuristic based on whether \p Tok is an identifier following
807  /// something that is likely a type.
808  bool isStartOfName(const FormatToken &Tok) {
809    if (Tok.isNot(tok::identifier) || !Tok.Previous)
810      return false;
811
812    // Skip "const" as it does not have an influence on whether this is a name.
813    FormatToken *PreviousNotConst = Tok.Previous;
814    while (PreviousNotConst && PreviousNotConst->is(tok::kw_const))
815      PreviousNotConst = PreviousNotConst->Previous;
816
817    if (!PreviousNotConst)
818      return false;
819
820    bool IsPPKeyword = PreviousNotConst->is(tok::identifier) &&
821                       PreviousNotConst->Previous &&
822                       PreviousNotConst->Previous->is(tok::hash);
823
824    if (PreviousNotConst->Type == TT_TemplateCloser)
825      return PreviousNotConst && PreviousNotConst->MatchingParen &&
826             PreviousNotConst->MatchingParen->Previous &&
827             PreviousNotConst->MatchingParen->Previous->isNot(tok::kw_template);
828
829    if (PreviousNotConst->is(tok::r_paren) && PreviousNotConst->MatchingParen &&
830        PreviousNotConst->MatchingParen->Previous &&
831        PreviousNotConst->MatchingParen->Previous->is(tok::kw_decltype))
832      return true;
833
834    return (!IsPPKeyword && PreviousNotConst->is(tok::identifier)) ||
835           PreviousNotConst->Type == TT_PointerOrReference ||
836           PreviousNotConst->isSimpleTypeSpecifier();
837  }
838
839  /// \brief Determine whether ')' is ending a cast.
840  bool rParenEndsCast(const FormatToken &Tok) {
841    FormatToken *LeftOfParens = nullptr;
842    if (Tok.MatchingParen)
843      LeftOfParens = Tok.MatchingParen->getPreviousNonComment();
844    bool IsCast = false;
845    bool ParensAreEmpty = Tok.Previous == Tok.MatchingParen;
846    bool ParensAreType = !Tok.Previous ||
847                         Tok.Previous->Type == TT_PointerOrReference ||
848                         Tok.Previous->Type == TT_TemplateCloser ||
849                         Tok.Previous->isSimpleTypeSpecifier();
850    bool ParensCouldEndDecl =
851        Tok.Next && Tok.Next->isOneOf(tok::equal, tok::semi, tok::l_brace);
852    bool IsSizeOfOrAlignOf =
853        LeftOfParens && LeftOfParens->isOneOf(tok::kw_sizeof, tok::kw_alignof);
854    if (ParensAreType && !ParensCouldEndDecl && !IsSizeOfOrAlignOf &&
855        ((Contexts.size() > 1 && Contexts[Contexts.size() - 2].IsExpression) ||
856         (Tok.Next && Tok.Next->isBinaryOperator())))
857      IsCast = true;
858    else if (Tok.Next && Tok.Next->isNot(tok::string_literal) &&
859             (Tok.Next->Tok.isLiteral() ||
860              Tok.Next->isOneOf(tok::kw_sizeof, tok::kw_alignof)))
861      IsCast = true;
862    // If there is an identifier after the (), it is likely a cast, unless
863    // there is also an identifier before the ().
864    else if (LeftOfParens &&
865             (LeftOfParens->Tok.getIdentifierInfo() == nullptr ||
866              LeftOfParens->is(tok::kw_return)) &&
867             LeftOfParens->Type != TT_OverloadedOperator &&
868             LeftOfParens->isNot(tok::at) &&
869             LeftOfParens->Type != TT_TemplateCloser && Tok.Next) {
870      if (Tok.Next->isOneOf(tok::identifier, tok::numeric_constant)) {
871        IsCast = true;
872      } else {
873        // Use heuristics to recognize c style casting.
874        FormatToken *Prev = Tok.Previous;
875        if (Prev && Prev->isOneOf(tok::amp, tok::star))
876          Prev = Prev->Previous;
877
878        if (Prev && Tok.Next && Tok.Next->Next) {
879          bool NextIsUnary = Tok.Next->isUnaryOperator() ||
880                             Tok.Next->isOneOf(tok::amp, tok::star);
881          IsCast = NextIsUnary && Tok.Next->Next->isOneOf(
882                                      tok::identifier, tok::numeric_constant);
883        }
884
885        for (; Prev != Tok.MatchingParen; Prev = Prev->Previous) {
886          if (!Prev || !Prev->isOneOf(tok::kw_const, tok::identifier)) {
887            IsCast = false;
888            break;
889          }
890        }
891      }
892    }
893    return IsCast && !ParensAreEmpty;
894  }
895
896  /// \brief Return the type of the given token assuming it is * or &.
897  TokenType determineStarAmpUsage(const FormatToken &Tok, bool IsExpression,
898                                  bool InTemplateArgument) {
899    const FormatToken *PrevToken = Tok.getPreviousNonComment();
900    if (!PrevToken)
901      return TT_UnaryOperator;
902
903    const FormatToken *NextToken = Tok.getNextNonComment();
904    if (!NextToken || NextToken->is(tok::l_brace))
905      return TT_Unknown;
906
907    if (PrevToken->is(tok::coloncolon) ||
908        (PrevToken->is(tok::l_paren) && !IsExpression))
909      return TT_PointerOrReference;
910
911    if (PrevToken->isOneOf(tok::l_paren, tok::l_square, tok::l_brace,
912                           tok::comma, tok::semi, tok::kw_return, tok::colon,
913                           tok::equal, tok::kw_delete, tok::kw_sizeof) ||
914        PrevToken->Type == TT_BinaryOperator ||
915        PrevToken->Type == TT_ConditionalExpr ||
916        PrevToken->Type == TT_UnaryOperator || PrevToken->Type == TT_CastRParen)
917      return TT_UnaryOperator;
918
919    if (NextToken->is(tok::l_square) && NextToken->Type != TT_LambdaLSquare)
920      return TT_PointerOrReference;
921    if (NextToken->is(tok::kw_operator))
922      return TT_PointerOrReference;
923
924    if (PrevToken->is(tok::r_paren) && PrevToken->MatchingParen &&
925        PrevToken->MatchingParen->Previous &&
926        PrevToken->MatchingParen->Previous->isOneOf(tok::kw_typeof,
927                                                    tok::kw_decltype))
928      return TT_PointerOrReference;
929
930    if (PrevToken->Tok.isLiteral() ||
931        PrevToken->isOneOf(tok::r_paren, tok::r_square, tok::kw_true,
932                           tok::kw_false) ||
933        NextToken->Tok.isLiteral() ||
934        NextToken->isOneOf(tok::kw_true, tok::kw_false) ||
935        NextToken->isUnaryOperator() ||
936        // If we know we're in a template argument, there are no named
937        // declarations. Thus, having an identifier on the right-hand side
938        // indicates a binary operator.
939        (InTemplateArgument && NextToken->Tok.isAnyIdentifier()))
940      return TT_BinaryOperator;
941
942    // This catches some cases where evaluation order is used as control flow:
943    //   aaa && aaa->f();
944    const FormatToken *NextNextToken = NextToken->getNextNonComment();
945    if (NextNextToken && NextNextToken->is(tok::arrow))
946      return TT_BinaryOperator;
947
948    // It is very unlikely that we are going to find a pointer or reference type
949    // definition on the RHS of an assignment.
950    if (IsExpression)
951      return TT_BinaryOperator;
952
953    return TT_PointerOrReference;
954  }
955
956  TokenType determinePlusMinusCaretUsage(const FormatToken &Tok) {
957    const FormatToken *PrevToken = Tok.getPreviousNonComment();
958    if (!PrevToken || PrevToken->Type == TT_CastRParen)
959      return TT_UnaryOperator;
960
961    // Use heuristics to recognize unary operators.
962    if (PrevToken->isOneOf(tok::equal, tok::l_paren, tok::comma, tok::l_square,
963                           tok::question, tok::colon, tok::kw_return,
964                           tok::kw_case, tok::at, tok::l_brace))
965      return TT_UnaryOperator;
966
967    // There can't be two consecutive binary operators.
968    if (PrevToken->Type == TT_BinaryOperator)
969      return TT_UnaryOperator;
970
971    // Fall back to marking the token as binary operator.
972    return TT_BinaryOperator;
973  }
974
975  /// \brief Determine whether ++/-- are pre- or post-increments/-decrements.
976  TokenType determineIncrementUsage(const FormatToken &Tok) {
977    const FormatToken *PrevToken = Tok.getPreviousNonComment();
978    if (!PrevToken || PrevToken->Type == TT_CastRParen)
979      return TT_UnaryOperator;
980    if (PrevToken->isOneOf(tok::r_paren, tok::r_square, tok::identifier))
981      return TT_TrailingUnaryOperator;
982
983    return TT_UnaryOperator;
984  }
985
986  SmallVector<Context, 8> Contexts;
987
988  const FormatStyle &Style;
989  AnnotatedLine &Line;
990  FormatToken *CurrentToken;
991  bool KeywordVirtualFound;
992  bool AutoFound;
993  IdentifierInfo &Ident_in;
994};
995
996static int PrecedenceUnaryOperator = prec::PointerToMember + 1;
997static int PrecedenceArrowAndPeriod = prec::PointerToMember + 2;
998
999/// \brief Parses binary expressions by inserting fake parenthesis based on
1000/// operator precedence.
1001class ExpressionParser {
1002public:
1003  ExpressionParser(AnnotatedLine &Line) : Current(Line.First) {
1004    // Skip leading "}", e.g. in "} else if (...) {".
1005    if (Current->is(tok::r_brace))
1006      next();
1007  }
1008
1009  /// \brief Parse expressions with the given operatore precedence.
1010  void parse(int Precedence = 0) {
1011    // Skip 'return' and ObjC selector colons as they are not part of a binary
1012    // expression.
1013    while (Current &&
1014           (Current->is(tok::kw_return) ||
1015            (Current->is(tok::colon) && (Current->Type == TT_ObjCMethodExpr ||
1016                                         Current->Type == TT_DictLiteral))))
1017      next();
1018
1019    if (!Current || Precedence > PrecedenceArrowAndPeriod)
1020      return;
1021
1022    // Conditional expressions need to be parsed separately for proper nesting.
1023    if (Precedence == prec::Conditional) {
1024      parseConditionalExpr();
1025      return;
1026    }
1027
1028    // Parse unary operators, which all have a higher precedence than binary
1029    // operators.
1030    if (Precedence == PrecedenceUnaryOperator) {
1031      parseUnaryOperator();
1032      return;
1033    }
1034
1035    FormatToken *Start = Current;
1036    FormatToken *LatestOperator = nullptr;
1037    unsigned OperatorIndex = 0;
1038
1039    while (Current) {
1040      // Consume operators with higher precedence.
1041      parse(Precedence + 1);
1042
1043      int CurrentPrecedence = getCurrentPrecedence();
1044
1045      if (Current && Current->Type == TT_SelectorName &&
1046          Precedence == CurrentPrecedence) {
1047        if (LatestOperator)
1048          addFakeParenthesis(Start, prec::Level(Precedence));
1049        Start = Current;
1050      }
1051
1052      // At the end of the line or when an operator with higher precedence is
1053      // found, insert fake parenthesis and return.
1054      if (!Current || Current->closesScope() ||
1055          (CurrentPrecedence != -1 && CurrentPrecedence < Precedence)) {
1056        if (LatestOperator) {
1057          LatestOperator->LastOperator = true;
1058          if (Precedence == PrecedenceArrowAndPeriod) {
1059            // Call expressions don't have a binary operator precedence.
1060            addFakeParenthesis(Start, prec::Unknown);
1061          } else {
1062            addFakeParenthesis(Start, prec::Level(Precedence));
1063          }
1064        }
1065        return;
1066      }
1067
1068      // Consume scopes: (), [], <> and {}
1069      if (Current->opensScope()) {
1070        while (Current && !Current->closesScope()) {
1071          next();
1072          parse();
1073        }
1074        next();
1075      } else {
1076        // Operator found.
1077        if (CurrentPrecedence == Precedence) {
1078          LatestOperator = Current;
1079          Current->OperatorIndex = OperatorIndex;
1080          ++OperatorIndex;
1081        }
1082
1083        next();
1084      }
1085    }
1086  }
1087
1088private:
1089  /// \brief Gets the precedence (+1) of the given token for binary operators
1090  /// and other tokens that we treat like binary operators.
1091  int getCurrentPrecedence() {
1092    if (Current) {
1093      if (Current->Type == TT_ConditionalExpr)
1094        return prec::Conditional;
1095      else if (Current->is(tok::semi) || Current->Type == TT_InlineASMColon ||
1096               Current->Type == TT_SelectorName)
1097        return 0;
1098      else if (Current->Type == TT_RangeBasedForLoopColon)
1099        return prec::Comma;
1100      else if (Current->Type == TT_BinaryOperator || Current->is(tok::comma))
1101        return Current->getPrecedence();
1102      else if (Current->isOneOf(tok::period, tok::arrow))
1103        return PrecedenceArrowAndPeriod;
1104    }
1105    return -1;
1106  }
1107
1108  void addFakeParenthesis(FormatToken *Start, prec::Level Precedence) {
1109    Start->FakeLParens.push_back(Precedence);
1110    if (Precedence > prec::Unknown)
1111      Start->StartsBinaryExpression = true;
1112    if (Current) {
1113      ++Current->Previous->FakeRParens;
1114      if (Precedence > prec::Unknown)
1115        Current->Previous->EndsBinaryExpression = true;
1116    }
1117  }
1118
1119  /// \brief Parse unary operator expressions and surround them with fake
1120  /// parentheses if appropriate.
1121  void parseUnaryOperator() {
1122    if (!Current || Current->Type != TT_UnaryOperator) {
1123      parse(PrecedenceArrowAndPeriod);
1124      return;
1125    }
1126
1127    FormatToken *Start = Current;
1128    next();
1129    parseUnaryOperator();
1130
1131    // The actual precedence doesn't matter.
1132    addFakeParenthesis(Start, prec::Unknown);
1133  }
1134
1135  void parseConditionalExpr() {
1136    FormatToken *Start = Current;
1137    parse(prec::LogicalOr);
1138    if (!Current || !Current->is(tok::question))
1139      return;
1140    next();
1141    parse(prec::LogicalOr);
1142    if (!Current || Current->Type != TT_ConditionalExpr)
1143      return;
1144    next();
1145    parseConditionalExpr();
1146    addFakeParenthesis(Start, prec::Conditional);
1147  }
1148
1149  void next() {
1150    if (Current)
1151      Current = Current->Next;
1152    while (Current && Current->isTrailingComment())
1153      Current = Current->Next;
1154  }
1155
1156  FormatToken *Current;
1157};
1158
1159} // end anonymous namespace
1160
1161void
1162TokenAnnotator::setCommentLineLevels(SmallVectorImpl<AnnotatedLine *> &Lines) {
1163  const AnnotatedLine *NextNonCommentLine = nullptr;
1164  for (SmallVectorImpl<AnnotatedLine *>::reverse_iterator I = Lines.rbegin(),
1165                                                          E = Lines.rend();
1166       I != E; ++I) {
1167    if (NextNonCommentLine && (*I)->First->is(tok::comment) &&
1168        (*I)->First->Next == nullptr)
1169      (*I)->Level = NextNonCommentLine->Level;
1170    else
1171      NextNonCommentLine = (*I)->First->isNot(tok::r_brace) ? (*I) : nullptr;
1172
1173    setCommentLineLevels((*I)->Children);
1174  }
1175}
1176
1177void TokenAnnotator::annotate(AnnotatedLine &Line) {
1178  for (SmallVectorImpl<AnnotatedLine *>::iterator I = Line.Children.begin(),
1179                                                  E = Line.Children.end();
1180       I != E; ++I) {
1181    annotate(**I);
1182  }
1183  AnnotatingParser Parser(Style, Line, Ident_in);
1184  Line.Type = Parser.parseLine();
1185  if (Line.Type == LT_Invalid)
1186    return;
1187
1188  ExpressionParser ExprParser(Line);
1189  ExprParser.parse();
1190
1191  if (Line.First->Type == TT_ObjCMethodSpecifier)
1192    Line.Type = LT_ObjCMethodDecl;
1193  else if (Line.First->Type == TT_ObjCDecl)
1194    Line.Type = LT_ObjCDecl;
1195  else if (Line.First->Type == TT_ObjCProperty)
1196    Line.Type = LT_ObjCProperty;
1197
1198  Line.First->SpacesRequiredBefore = 1;
1199  Line.First->CanBreakBefore = Line.First->MustBreakBefore;
1200}
1201
1202// This function heuristically determines whether 'Current' starts the name of a
1203// function declaration.
1204static bool isFunctionDeclarationName(const FormatToken &Current) {
1205  if (Current.Type != TT_StartOfName ||
1206      Current.NestingLevel != 0 ||
1207      Current.Previous->Type == TT_StartOfName)
1208    return false;
1209  const FormatToken *Next = Current.Next;
1210  for (; Next; Next = Next->Next) {
1211    if (Next->Type == TT_TemplateOpener) {
1212      Next = Next->MatchingParen;
1213    } else if (Next->is(tok::coloncolon)) {
1214      Next = Next->Next;
1215      if (!Next || !Next->is(tok::identifier))
1216        return false;
1217    } else if (Next->is(tok::l_paren)) {
1218      break;
1219    } else {
1220      return false;
1221    }
1222  }
1223  if (!Next)
1224    return false;
1225  assert(Next->is(tok::l_paren));
1226  if (Next->Next == Next->MatchingParen)
1227    return true;
1228  for (const FormatToken *Tok = Next->Next; Tok != Next->MatchingParen;
1229       Tok = Tok->Next) {
1230    if (Tok->is(tok::kw_const) || Tok->isSimpleTypeSpecifier() ||
1231        Tok->Type == TT_PointerOrReference || Tok->Type == TT_StartOfName)
1232      return true;
1233    if (Tok->isOneOf(tok::l_brace, tok::string_literal) || Tok->Tok.isLiteral())
1234      return false;
1235  }
1236  return false;
1237}
1238
1239void TokenAnnotator::calculateFormattingInformation(AnnotatedLine &Line) {
1240  for (SmallVectorImpl<AnnotatedLine *>::iterator I = Line.Children.begin(),
1241                                                  E = Line.Children.end();
1242       I != E; ++I) {
1243    calculateFormattingInformation(**I);
1244  }
1245
1246  Line.First->TotalLength =
1247      Line.First->IsMultiline ? Style.ColumnLimit : Line.First->ColumnWidth;
1248  if (!Line.First->Next)
1249    return;
1250  FormatToken *Current = Line.First->Next;
1251  bool InFunctionDecl = Line.MightBeFunctionDecl;
1252  while (Current) {
1253    if (isFunctionDeclarationName(*Current))
1254      Current->Type = TT_FunctionDeclarationName;
1255    if (Current->Type == TT_LineComment) {
1256      if (Current->Previous->BlockKind == BK_BracedInit &&
1257          Current->Previous->opensScope())
1258        Current->SpacesRequiredBefore = Style.Cpp11BracedListStyle ? 0 : 1;
1259      else
1260        Current->SpacesRequiredBefore = Style.SpacesBeforeTrailingComments;
1261
1262      // If we find a trailing comment, iterate backwards to determine whether
1263      // it seems to relate to a specific parameter. If so, break before that
1264      // parameter to avoid changing the comment's meaning. E.g. don't move 'b'
1265      // to the previous line in:
1266      //   SomeFunction(a,
1267      //                b, // comment
1268      //                c);
1269      if (!Current->HasUnescapedNewline) {
1270        for (FormatToken *Parameter = Current->Previous; Parameter;
1271             Parameter = Parameter->Previous) {
1272          if (Parameter->isOneOf(tok::comment, tok::r_brace))
1273            break;
1274          if (Parameter->Previous && Parameter->Previous->is(tok::comma)) {
1275            if (Parameter->Previous->Type != TT_CtorInitializerComma &&
1276                Parameter->HasUnescapedNewline)
1277              Parameter->MustBreakBefore = true;
1278            break;
1279          }
1280        }
1281      }
1282    } else if (Current->SpacesRequiredBefore == 0 &&
1283               spaceRequiredBefore(Line, *Current)) {
1284      Current->SpacesRequiredBefore = 1;
1285    }
1286
1287    Current->MustBreakBefore =
1288        Current->MustBreakBefore || mustBreakBefore(Line, *Current);
1289
1290    Current->CanBreakBefore =
1291        Current->MustBreakBefore || canBreakBefore(Line, *Current);
1292    unsigned ChildSize = 0;
1293    if (Current->Previous->Children.size() == 1) {
1294      FormatToken &LastOfChild = *Current->Previous->Children[0]->Last;
1295      ChildSize = LastOfChild.isTrailingComment() ? Style.ColumnLimit
1296                                                  : LastOfChild.TotalLength + 1;
1297    }
1298    if (Current->MustBreakBefore || Current->Previous->Children.size() > 1 ||
1299        Current->IsMultiline)
1300      Current->TotalLength = Current->Previous->TotalLength + Style.ColumnLimit;
1301    else
1302      Current->TotalLength = Current->Previous->TotalLength +
1303                             Current->ColumnWidth + ChildSize +
1304                             Current->SpacesRequiredBefore;
1305
1306    if (Current->Type == TT_CtorInitializerColon)
1307      InFunctionDecl = false;
1308
1309    // FIXME: Only calculate this if CanBreakBefore is true once static
1310    // initializers etc. are sorted out.
1311    // FIXME: Move magic numbers to a better place.
1312    Current->SplitPenalty = 20 * Current->BindingStrength +
1313                            splitPenalty(Line, *Current, InFunctionDecl);
1314
1315    Current = Current->Next;
1316  }
1317
1318  calculateUnbreakableTailLengths(Line);
1319  for (Current = Line.First; Current != nullptr; Current = Current->Next) {
1320    if (Current->Role)
1321      Current->Role->precomputeFormattingInfos(Current);
1322  }
1323
1324  DEBUG({ printDebugInfo(Line); });
1325}
1326
1327void TokenAnnotator::calculateUnbreakableTailLengths(AnnotatedLine &Line) {
1328  unsigned UnbreakableTailLength = 0;
1329  FormatToken *Current = Line.Last;
1330  while (Current) {
1331    Current->UnbreakableTailLength = UnbreakableTailLength;
1332    if (Current->CanBreakBefore ||
1333        Current->isOneOf(tok::comment, tok::string_literal)) {
1334      UnbreakableTailLength = 0;
1335    } else {
1336      UnbreakableTailLength +=
1337          Current->ColumnWidth + Current->SpacesRequiredBefore;
1338    }
1339    Current = Current->Previous;
1340  }
1341}
1342
1343unsigned TokenAnnotator::splitPenalty(const AnnotatedLine &Line,
1344                                      const FormatToken &Tok,
1345                                      bool InFunctionDecl) {
1346  const FormatToken &Left = *Tok.Previous;
1347  const FormatToken &Right = Tok;
1348
1349  if (Left.is(tok::semi))
1350    return 0;
1351  if (Left.is(tok::comma) || (Right.is(tok::identifier) && Right.Next &&
1352                              Right.Next->Type == TT_DictLiteral))
1353    return 1;
1354  if (Right.is(tok::l_square)) {
1355    if (Style.Language == FormatStyle::LK_Proto)
1356      return 1;
1357    if (Right.Type != TT_ObjCMethodExpr && Right.Type != TT_LambdaLSquare)
1358      return 500;
1359  }
1360  if (Right.Type == TT_StartOfName ||
1361      Right.Type == TT_FunctionDeclarationName || Right.is(tok::kw_operator)) {
1362    if (Line.First->is(tok::kw_for) && Right.PartOfMultiVariableDeclStmt)
1363      return 3;
1364    if (Left.Type == TT_StartOfName)
1365      return 20;
1366    if (InFunctionDecl && Right.NestingLevel == 0)
1367      return Style.PenaltyReturnTypeOnItsOwnLine;
1368    return 200;
1369  }
1370  if (Left.is(tok::equal) && Right.is(tok::l_brace))
1371    return 150;
1372  if (Left.Type == TT_CastRParen)
1373    return 100;
1374  if (Left.is(tok::coloncolon) ||
1375      (Right.is(tok::period) && Style.Language == FormatStyle::LK_Proto))
1376    return 500;
1377  if (Left.isOneOf(tok::kw_class, tok::kw_struct))
1378    return 5000;
1379
1380  if (Left.Type == TT_RangeBasedForLoopColon ||
1381      Left.Type == TT_InheritanceColon)
1382    return 2;
1383
1384  if (Right.isMemberAccess()) {
1385    if (Left.is(tok::r_paren) && Left.MatchingParen &&
1386        Left.MatchingParen->ParameterCount > 0)
1387      return 20; // Should be smaller than breaking at a nested comma.
1388    return 150;
1389  }
1390
1391  if (Right.Type == TT_TrailingAnnotation &&
1392      (!Right.Next || Right.Next->isNot(tok::l_paren))) {
1393    // Generally, breaking before a trailing annotation is bad unless it is
1394    // function-like. It seems to be especially preferable to keep standard
1395    // annotations (i.e. "const", "final" and "override") on the same line.
1396    // Use a slightly higher penalty after ")" so that annotations like
1397    // "const override" are kept together.
1398    bool is_short_annotation = Right.TokenText.size() < 10;
1399    return (Left.is(tok::r_paren) ? 100 : 120) + (is_short_annotation ? 50 : 0);
1400  }
1401
1402  // In for-loops, prefer breaking at ',' and ';'.
1403  if (Line.First->is(tok::kw_for) && Left.is(tok::equal))
1404    return 4;
1405
1406  // In Objective-C method expressions, prefer breaking before "param:" over
1407  // breaking after it.
1408  if (Right.Type == TT_SelectorName)
1409    return 0;
1410  if (Left.is(tok::colon) && Left.Type == TT_ObjCMethodExpr)
1411    return Line.MightBeFunctionDecl ? 50 : 500;
1412
1413  if (Left.is(tok::l_paren) && InFunctionDecl)
1414    return 100;
1415  if (Left.is(tok::equal) && InFunctionDecl)
1416    return 110;
1417  if (Left.opensScope())
1418    return Left.ParameterCount > 1 ? Style.PenaltyBreakBeforeFirstCallParameter
1419                                   : 19;
1420
1421  if (Right.is(tok::lessless)) {
1422    if (Left.is(tok::string_literal)) {
1423      StringRef Content = Left.TokenText;
1424      if (Content.startswith("\""))
1425        Content = Content.drop_front(1);
1426      if (Content.endswith("\""))
1427        Content = Content.drop_back(1);
1428      Content = Content.trim();
1429      if (Content.size() > 1 &&
1430          (Content.back() == ':' || Content.back() == '='))
1431        return 25;
1432    }
1433    return 1; // Breaking at a << is really cheap.
1434  }
1435  if (Left.Type == TT_ConditionalExpr)
1436    return prec::Conditional;
1437  prec::Level Level = Left.getPrecedence();
1438
1439  if (Level != prec::Unknown)
1440    return Level;
1441
1442  return 3;
1443}
1444
1445bool TokenAnnotator::spaceRequiredBetween(const AnnotatedLine &Line,
1446                                          const FormatToken &Left,
1447                                          const FormatToken &Right) {
1448  if (Style.Language == FormatStyle::LK_Proto) {
1449    if (Right.is(tok::period) &&
1450        (Left.TokenText == "optional" || Left.TokenText == "required" ||
1451         Left.TokenText == "repeated"))
1452      return true;
1453    if (Right.is(tok::l_paren) &&
1454        (Left.TokenText == "returns" || Left.TokenText == "option"))
1455      return true;
1456  } else if (Style.Language == FormatStyle::LK_JavaScript) {
1457    if (Left.TokenText == "var")
1458      return true;
1459  }
1460  if (Left.is(tok::kw_return) && Right.isNot(tok::semi))
1461    return true;
1462  if (Style.ObjCSpaceAfterProperty && Line.Type == LT_ObjCProperty &&
1463      Left.Tok.getObjCKeywordID() == tok::objc_property)
1464    return true;
1465  if (Right.is(tok::hashhash))
1466    return Left.is(tok::hash);
1467  if (Left.isOneOf(tok::hashhash, tok::hash))
1468    return Right.is(tok::hash);
1469  if (Left.is(tok::l_paren) && Right.is(tok::r_paren))
1470    return Style.SpaceInEmptyParentheses;
1471  if (Left.is(tok::l_paren) || Right.is(tok::r_paren))
1472    return (Right.Type == TT_CastRParen ||
1473            (Left.MatchingParen && Left.MatchingParen->Type == TT_CastRParen))
1474               ? Style.SpacesInCStyleCastParentheses
1475               : Style.SpacesInParentheses;
1476  if (Style.SpacesInAngles &&
1477      ((Left.Type == TT_TemplateOpener) != (Right.Type == TT_TemplateCloser)))
1478    return true;
1479  if (Right.isOneOf(tok::semi, tok::comma))
1480    return false;
1481  if (Right.is(tok::less) &&
1482      (Left.is(tok::kw_template) ||
1483       (Line.Type == LT_ObjCDecl && Style.ObjCSpaceBeforeProtocolList)))
1484    return true;
1485  if (Left.is(tok::arrow) || Right.is(tok::arrow))
1486    return false;
1487  if (Left.isOneOf(tok::exclaim, tok::tilde))
1488    return false;
1489  if (Left.is(tok::at) &&
1490      Right.isOneOf(tok::identifier, tok::string_literal, tok::char_constant,
1491                    tok::numeric_constant, tok::l_paren, tok::l_brace,
1492                    tok::kw_true, tok::kw_false))
1493    return false;
1494  if (Left.is(tok::coloncolon))
1495    return false;
1496  if (Right.is(tok::coloncolon) && Left.isNot(tok::l_brace))
1497    return (Left.is(tok::less) && Style.Standard == FormatStyle::LS_Cpp03) ||
1498           !Left.isOneOf(tok::identifier, tok::greater, tok::l_paren,
1499                         tok::r_paren, tok::less);
1500  if (Left.is(tok::less) || Right.isOneOf(tok::greater, tok::less))
1501    return false;
1502  if (Right.is(tok::ellipsis))
1503    return Left.Tok.isLiteral();
1504  if (Left.is(tok::l_square) && Right.is(tok::amp))
1505    return false;
1506  if (Right.Type == TT_PointerOrReference)
1507    return Left.Tok.isLiteral() ||
1508           ((Left.Type != TT_PointerOrReference) && Left.isNot(tok::l_paren) &&
1509            Style.PointerAlignment != FormatStyle::PAS_Left);
1510  if (Right.Type == TT_FunctionTypeLParen && Left.isNot(tok::l_paren) &&
1511      (Left.Type != TT_PointerOrReference || Style.PointerAlignment != FormatStyle::PAS_Right))
1512    return true;
1513  if (Left.Type == TT_PointerOrReference)
1514    return Right.Tok.isLiteral() || Right.Type == TT_BlockComment ||
1515           ((Right.Type != TT_PointerOrReference) &&
1516            Right.isNot(tok::l_paren) && Style.PointerAlignment != FormatStyle::PAS_Right &&
1517            Left.Previous &&
1518            !Left.Previous->isOneOf(tok::l_paren, tok::coloncolon));
1519  if (Right.is(tok::star) && Left.is(tok::l_paren))
1520    return false;
1521  if (Left.is(tok::l_square))
1522    return Left.Type == TT_ArrayInitializerLSquare &&
1523           Style.SpacesInContainerLiterals && Right.isNot(tok::r_square);
1524  if (Right.is(tok::r_square))
1525    return Right.MatchingParen && Style.SpacesInContainerLiterals &&
1526           Right.MatchingParen->Type == TT_ArrayInitializerLSquare;
1527  if (Right.is(tok::l_square) && Right.Type != TT_ObjCMethodExpr &&
1528      Right.Type != TT_LambdaLSquare && Left.isNot(tok::numeric_constant) &&
1529      Left.Type != TT_DictLiteral)
1530    return false;
1531  if (Left.is(tok::colon))
1532    return Left.Type != TT_ObjCMethodExpr;
1533  if (Left.Type == TT_BlockComment)
1534    return !Left.TokenText.endswith("=*/");
1535  if (Right.is(tok::l_paren)) {
1536    if (Left.is(tok::r_paren) && Left.Type == TT_AttributeParen)
1537      return true;
1538    return Line.Type == LT_ObjCDecl ||
1539           Left.isOneOf(tok::kw_new, tok::kw_delete, tok::semi) ||
1540           (Style.SpaceBeforeParens != FormatStyle::SBPO_Never &&
1541            (Left.isOneOf(tok::kw_if, tok::kw_for, tok::kw_while,
1542                          tok::kw_switch, tok::kw_catch, tok::kw_case) ||
1543             Left.IsForEachMacro)) ||
1544           (Style.SpaceBeforeParens == FormatStyle::SBPO_Always &&
1545            Left.isOneOf(tok::identifier, tok::kw___attribute) &&
1546            Line.Type != LT_PreprocessorDirective);
1547  }
1548  if (Left.is(tok::at) && Right.Tok.getObjCKeywordID() != tok::objc_not_keyword)
1549    return false;
1550  if (Left.is(tok::l_brace) && Right.is(tok::r_brace))
1551    return !Left.Children.empty(); // No spaces in "{}".
1552  if ((Left.is(tok::l_brace) && Left.BlockKind != BK_Block) ||
1553      (Right.is(tok::r_brace) && Right.MatchingParen &&
1554       Right.MatchingParen->BlockKind != BK_Block))
1555    return !Style.Cpp11BracedListStyle;
1556  if (Right.Type == TT_UnaryOperator)
1557    return !Left.isOneOf(tok::l_paren, tok::l_square, tok::at) &&
1558           (Left.isNot(tok::colon) || Left.Type != TT_ObjCMethodExpr);
1559  if ((Left.isOneOf(tok::identifier, tok::greater, tok::r_square,
1560                    tok::r_paren) ||
1561       Left.isSimpleTypeSpecifier()) &&
1562      Right.is(tok::l_brace) && Right.getNextNonComment() &&
1563      Right.BlockKind != BK_Block)
1564    return false;
1565  if (Left.is(tok::period) || Right.is(tok::period))
1566    return false;
1567  if (Right.is(tok::hash) && Left.is(tok::identifier) && Left.TokenText == "L")
1568    return false;
1569  return true;
1570}
1571
1572bool TokenAnnotator::spaceRequiredBefore(const AnnotatedLine &Line,
1573                                         const FormatToken &Tok) {
1574  if (Tok.Tok.getIdentifierInfo() && Tok.Previous->Tok.getIdentifierInfo())
1575    return true; // Never ever merge two identifiers.
1576  if (Tok.Previous->Type == TT_ImplicitStringLiteral)
1577    return Tok.WhitespaceRange.getBegin() != Tok.WhitespaceRange.getEnd();
1578  if (Line.Type == LT_ObjCMethodDecl) {
1579    if (Tok.Previous->Type == TT_ObjCMethodSpecifier)
1580      return true;
1581    if (Tok.Previous->is(tok::r_paren) && Tok.is(tok::identifier))
1582      // Don't space between ')' and <id>
1583      return false;
1584  }
1585  if (Line.Type == LT_ObjCProperty &&
1586      (Tok.is(tok::equal) || Tok.Previous->is(tok::equal)))
1587    return false;
1588
1589  if (Tok.Type == TT_TrailingReturnArrow ||
1590      Tok.Previous->Type == TT_TrailingReturnArrow)
1591    return true;
1592  if (Tok.Previous->is(tok::comma))
1593    return true;
1594  if (Tok.is(tok::comma))
1595    return false;
1596  if (Tok.Type == TT_CtorInitializerColon || Tok.Type == TT_ObjCBlockLParen)
1597    return true;
1598  if (Tok.Previous->Tok.is(tok::kw_operator))
1599    return Tok.is(tok::coloncolon);
1600  if (Tok.Type == TT_OverloadedOperatorLParen)
1601    return false;
1602  if (Tok.is(tok::colon))
1603    return !Line.First->isOneOf(tok::kw_case, tok::kw_default) &&
1604           Tok.getNextNonComment() && Tok.Type != TT_ObjCMethodExpr &&
1605           !Tok.Previous->is(tok::question) &&
1606           (Tok.Type != TT_DictLiteral || Style.SpacesInContainerLiterals);
1607  if (Tok.Previous->Type == TT_UnaryOperator ||
1608      Tok.Previous->Type == TT_CastRParen)
1609    return Tok.Type == TT_BinaryOperator;
1610  if (Tok.Previous->is(tok::greater) && Tok.is(tok::greater)) {
1611    return Tok.Type == TT_TemplateCloser &&
1612           Tok.Previous->Type == TT_TemplateCloser &&
1613           (Style.Standard != FormatStyle::LS_Cpp11 || Style.SpacesInAngles);
1614  }
1615  if (Tok.isOneOf(tok::arrowstar, tok::periodstar) ||
1616      Tok.Previous->isOneOf(tok::arrowstar, tok::periodstar))
1617    return false;
1618  if (!Style.SpaceBeforeAssignmentOperators &&
1619      Tok.getPrecedence() == prec::Assignment)
1620    return false;
1621  if ((Tok.Type == TT_BinaryOperator && !Tok.Previous->is(tok::l_paren)) ||
1622      Tok.Previous->Type == TT_BinaryOperator ||
1623      Tok.Previous->Type == TT_ConditionalExpr)
1624    return true;
1625  if (Tok.Previous->Type == TT_TemplateCloser && Tok.is(tok::l_paren))
1626    return false;
1627  if (Tok.is(tok::less) && Tok.Previous->isNot(tok::l_paren) &&
1628      Line.First->is(tok::hash))
1629    return true;
1630  if (Tok.Type == TT_TrailingUnaryOperator)
1631    return false;
1632  if (Tok.Previous->Type == TT_RegexLiteral)
1633    return false;
1634  return spaceRequiredBetween(Line, *Tok.Previous, Tok);
1635}
1636
1637// Returns 'true' if 'Tok' is a brace we'd want to break before in Allman style.
1638static bool isAllmanBrace(const FormatToken &Tok) {
1639  return Tok.is(tok::l_brace) && Tok.BlockKind == BK_Block &&
1640         Tok.Type != TT_ObjCBlockLBrace && Tok.Type != TT_DictLiteral;
1641}
1642
1643bool TokenAnnotator::mustBreakBefore(const AnnotatedLine &Line,
1644                                     const FormatToken &Right) {
1645  const FormatToken &Left = *Right.Previous;
1646  if (Right.NewlinesBefore > 1)
1647    return true;
1648  if (Right.is(tok::comment)) {
1649    return Right.Previous->BlockKind != BK_BracedInit &&
1650           Right.Previous->Type != TT_CtorInitializerColon &&
1651           (Right.NewlinesBefore > 0 && Right.HasUnescapedNewline);
1652  } else if (Right.Previous->isTrailingComment() ||
1653             (Right.isStringLiteral() && Right.Previous->isStringLiteral())) {
1654    return true;
1655  } else if (Right.Previous->IsUnterminatedLiteral) {
1656    return true;
1657  } else if (Right.is(tok::lessless) && Right.Next &&
1658             Right.Previous->is(tok::string_literal) &&
1659             Right.Next->is(tok::string_literal)) {
1660    return true;
1661  } else if (Right.Previous->ClosesTemplateDeclaration &&
1662             Right.Previous->MatchingParen &&
1663             Right.Previous->MatchingParen->NestingLevel == 0 &&
1664             Style.AlwaysBreakTemplateDeclarations) {
1665    return true;
1666  } else if ((Right.Type == TT_CtorInitializerComma ||
1667              Right.Type == TT_CtorInitializerColon) &&
1668             Style.BreakConstructorInitializersBeforeComma &&
1669             !Style.ConstructorInitializerAllOnOneLineOrOnePerLine) {
1670    return true;
1671  } else if (Right.is(tok::string_literal) &&
1672             Right.TokenText.startswith("R\"")) {
1673    // Raw string literals are special wrt. line breaks. The author has made a
1674    // deliberate choice and might have aligned the contents of the string
1675    // literal accordingly. Thus, we try keep existing line breaks.
1676    return Right.NewlinesBefore > 0;
1677  } else if (Right.Previous->is(tok::l_brace) && Right.NestingLevel == 1 &&
1678             Style.Language == FormatStyle::LK_Proto) {
1679    // Don't enums onto single lines in protocol buffers.
1680    return true;
1681  } else if (isAllmanBrace(Left) || isAllmanBrace(Right)) {
1682    return Style.BreakBeforeBraces == FormatStyle::BS_Allman ||
1683           Style.BreakBeforeBraces == FormatStyle::BS_GNU;
1684  }
1685
1686  // If the last token before a '}' is a comma or a comment, the intention is to
1687  // insert a line break after it in order to make shuffling around entries
1688  // easier.
1689  const FormatToken *BeforeClosingBrace = nullptr;
1690  if (Left.is(tok::l_brace) && Left.MatchingParen)
1691    BeforeClosingBrace = Left.MatchingParen->Previous;
1692  else if (Right.is(tok::r_brace))
1693    BeforeClosingBrace = Right.Previous;
1694  if (BeforeClosingBrace &&
1695      BeforeClosingBrace->isOneOf(tok::comma, tok::comment))
1696    return true;
1697
1698  if (Style.Language == FormatStyle::LK_JavaScript) {
1699    // FIXME: This might apply to other languages and token kinds.
1700    if (Right.is(tok::char_constant) && Left.is(tok::plus) && Left.Previous &&
1701        Left.Previous->is(tok::char_constant))
1702      return true;
1703  }
1704
1705  return false;
1706}
1707
1708bool TokenAnnotator::canBreakBefore(const AnnotatedLine &Line,
1709                                    const FormatToken &Right) {
1710  const FormatToken &Left = *Right.Previous;
1711  if (Left.is(tok::at))
1712    return false;
1713  if (Left.Tok.getObjCKeywordID() == tok::objc_interface)
1714    return false;
1715  if (Right.Type == TT_StartOfName ||
1716      Right.Type == TT_FunctionDeclarationName || Right.is(tok::kw_operator))
1717    return true;
1718  if (Right.isTrailingComment())
1719    // We rely on MustBreakBefore being set correctly here as we should not
1720    // change the "binding" behavior of a comment.
1721    // The first comment in a braced lists is always interpreted as belonging to
1722    // the first list element. Otherwise, it should be placed outside of the
1723    // list.
1724    return Left.BlockKind == BK_BracedInit;
1725  if (Left.is(tok::question) && Right.is(tok::colon))
1726    return false;
1727  if (Right.Type == TT_ConditionalExpr || Right.is(tok::question))
1728    return Style.BreakBeforeTernaryOperators;
1729  if (Left.Type == TT_ConditionalExpr || Left.is(tok::question))
1730    return !Style.BreakBeforeTernaryOperators;
1731  if (Right.Type == TT_InheritanceColon)
1732    return true;
1733  if (Right.is(tok::colon) && (Right.Type != TT_CtorInitializerColon &&
1734                               Right.Type != TT_InlineASMColon))
1735    return false;
1736  if (Left.is(tok::colon) &&
1737      (Left.Type == TT_DictLiteral || Left.Type == TT_ObjCMethodExpr))
1738    return true;
1739  if (Right.Type == TT_SelectorName)
1740    return true;
1741  if (Left.is(tok::r_paren) && Line.Type == LT_ObjCProperty)
1742    return true;
1743  if (Left.ClosesTemplateDeclaration)
1744    return true;
1745  if (Right.Type == TT_RangeBasedForLoopColon ||
1746      Right.Type == TT_OverloadedOperatorLParen ||
1747      Right.Type == TT_OverloadedOperator)
1748    return false;
1749  if (Left.Type == TT_RangeBasedForLoopColon)
1750    return true;
1751  if (Right.Type == TT_RangeBasedForLoopColon)
1752    return false;
1753  if (Left.Type == TT_PointerOrReference || Left.Type == TT_TemplateCloser ||
1754      Left.Type == TT_UnaryOperator || Left.is(tok::kw_operator))
1755    return false;
1756  if (Left.is(tok::equal) && Line.Type == LT_VirtualFunctionDecl)
1757    return false;
1758  if (Left.is(tok::l_paren) && Left.Type == TT_AttributeParen)
1759    return false;
1760  if (Left.is(tok::l_paren) && Left.Previous &&
1761      (Left.Previous->Type == TT_BinaryOperator ||
1762       Left.Previous->Type == TT_CastRParen || Left.Previous->is(tok::kw_if)))
1763    return false;
1764  if (Right.Type == TT_ImplicitStringLiteral)
1765    return false;
1766
1767  if (Right.is(tok::r_paren) || Right.Type == TT_TemplateCloser)
1768    return false;
1769
1770  // We only break before r_brace if there was a corresponding break before
1771  // the l_brace, which is tracked by BreakBeforeClosingBrace.
1772  if (Right.is(tok::r_brace))
1773    return Right.MatchingParen && Right.MatchingParen->BlockKind == BK_Block;
1774
1775  // Allow breaking after a trailing annotation, e.g. after a method
1776  // declaration.
1777  if (Left.Type == TT_TrailingAnnotation)
1778    return !Right.isOneOf(tok::l_brace, tok::semi, tok::equal, tok::l_paren,
1779                          tok::less, tok::coloncolon);
1780
1781  if (Right.is(tok::kw___attribute))
1782    return true;
1783
1784  if (Left.is(tok::identifier) && Right.is(tok::string_literal))
1785    return true;
1786
1787  if (Right.is(tok::identifier) && Right.Next &&
1788      Right.Next->Type == TT_DictLiteral)
1789    return true;
1790
1791  if (Left.Type == TT_CtorInitializerComma &&
1792      Style.BreakConstructorInitializersBeforeComma)
1793    return false;
1794  if (Right.Type == TT_CtorInitializerComma &&
1795      Style.BreakConstructorInitializersBeforeComma)
1796    return true;
1797  if (Left.is(tok::greater) && Right.is(tok::greater) &&
1798      Left.Type != TT_TemplateCloser)
1799    return false;
1800  if (Right.Type == TT_BinaryOperator && Style.BreakBeforeBinaryOperators)
1801    return true;
1802  if (Left.Type == TT_ArrayInitializerLSquare)
1803    return true;
1804  return (Left.isBinaryOperator() &&
1805          !Left.isOneOf(tok::arrowstar, tok::lessless) &&
1806          !Style.BreakBeforeBinaryOperators) ||
1807         Left.isOneOf(tok::comma, tok::coloncolon, tok::semi, tok::l_brace,
1808                      tok::kw_class, tok::kw_struct) ||
1809         Right.isMemberAccess() ||
1810         Right.isOneOf(tok::lessless, tok::colon, tok::l_square, tok::at) ||
1811         (Left.is(tok::r_paren) &&
1812          Right.isOneOf(tok::identifier, tok::kw_const)) ||
1813         (Left.is(tok::l_paren) && !Right.is(tok::r_paren));
1814}
1815
1816void TokenAnnotator::printDebugInfo(const AnnotatedLine &Line) {
1817  llvm::errs() << "AnnotatedTokens:\n";
1818  const FormatToken *Tok = Line.First;
1819  while (Tok) {
1820    llvm::errs() << " M=" << Tok->MustBreakBefore
1821                 << " C=" << Tok->CanBreakBefore << " T=" << Tok->Type
1822                 << " S=" << Tok->SpacesRequiredBefore
1823                 << " B=" << Tok->BlockParameterCount
1824                 << " P=" << Tok->SplitPenalty << " Name=" << Tok->Tok.getName()
1825                 << " L=" << Tok->TotalLength << " PPK=" << Tok->PackingKind
1826                 << " FakeLParens=";
1827    for (unsigned i = 0, e = Tok->FakeLParens.size(); i != e; ++i)
1828      llvm::errs() << Tok->FakeLParens[i] << "/";
1829    llvm::errs() << " FakeRParens=" << Tok->FakeRParens << "\n";
1830    if (!Tok->Next)
1831      assert(Tok == Line.Last);
1832    Tok = Tok->Next;
1833  }
1834  llvm::errs() << "----\n";
1835}
1836
1837} // namespace format
1838} // namespace clang
1839