1 //===--- FormatToken.h - Format C++ code ------------------------*- C++ -*-===//
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 contains the declaration of the FormatToken, a wrapper
11 /// around Token with additional information related to formatting.
12 ///
13 //===----------------------------------------------------------------------===//
14 
15 #ifndef LLVM_CLANG_LIB_FORMAT_FORMATTOKEN_H
16 #define LLVM_CLANG_LIB_FORMAT_FORMATTOKEN_H
17 
18 #include "clang/Basic/IdentifierTable.h"
19 #include "clang/Basic/OperatorPrecedence.h"
20 #include "clang/Format/Format.h"
21 #include "clang/Lex/Lexer.h"
22 #include <memory>
23 #include <unordered_set>
24 
25 namespace clang {
26 namespace format {
27 
28 #define LIST_TOKEN_TYPES                                                       \
29   TYPE(ArrayInitializerLSquare)                                                \
30   TYPE(ArraySubscriptLSquare)                                                  \
31   TYPE(AttributeColon)                                                         \
32   TYPE(AttributeParen)                                                         \
33   TYPE(AttributeSquare)                                                        \
34   TYPE(BinaryOperator)                                                         \
35   TYPE(BitFieldColon)                                                          \
36   TYPE(BlockComment)                                                           \
37   TYPE(CastRParen)                                                             \
38   TYPE(ConditionalExpr)                                                        \
39   TYPE(ConflictAlternative)                                                    \
40   TYPE(ConflictEnd)                                                            \
41   TYPE(ConflictStart)                                                          \
42   TYPE(CtorInitializerColon)                                                   \
43   TYPE(CtorInitializerComma)                                                   \
44   TYPE(DesignatedInitializerLSquare)                                           \
45   TYPE(DesignatedInitializerPeriod)                                            \
46   TYPE(DictLiteral)                                                            \
47   TYPE(ForEachMacro)                                                           \
48   TYPE(FunctionAnnotationRParen)                                               \
49   TYPE(FunctionDeclarationName)                                                \
50   TYPE(FunctionLBrace)                                                         \
51   TYPE(FunctionTypeLParen)                                                     \
52   TYPE(ImplicitStringLiteral)                                                  \
53   TYPE(InheritanceColon)                                                       \
54   TYPE(InheritanceComma)                                                       \
55   TYPE(InlineASMBrace)                                                         \
56   TYPE(InlineASMColon)                                                         \
57   TYPE(JavaAnnotation)                                                         \
58   TYPE(JsComputedPropertyName)                                                 \
59   TYPE(JsExponentiation)                                                       \
60   TYPE(JsExponentiationEqual)                                                  \
61   TYPE(JsFatArrow)                                                             \
62   TYPE(JsNonNullAssertion)                                                     \
63   TYPE(JsPrivateIdentifier)                                                    \
64   TYPE(JsTypeColon)                                                            \
65   TYPE(JsTypeOperator)                                                         \
66   TYPE(JsTypeOptionalQuestion)                                                 \
67   TYPE(LambdaArrow)                                                            \
68   TYPE(LambdaLBrace)                                                           \
69   TYPE(LambdaLSquare)                                                          \
70   TYPE(LeadingJavaAnnotation)                                                  \
71   TYPE(LineComment)                                                            \
72   TYPE(MacroBlockBegin)                                                        \
73   TYPE(MacroBlockEnd)                                                          \
74   TYPE(ObjCBlockLBrace)                                                        \
75   TYPE(ObjCBlockLParen)                                                        \
76   TYPE(ObjCDecl)                                                               \
77   TYPE(ObjCForIn)                                                              \
78   TYPE(ObjCMethodExpr)                                                         \
79   TYPE(ObjCMethodSpecifier)                                                    \
80   TYPE(ObjCProperty)                                                           \
81   TYPE(ObjCStringLiteral)                                                      \
82   TYPE(OverloadedOperator)                                                     \
83   TYPE(OverloadedOperatorLParen)                                               \
84   TYPE(PointerOrReference)                                                     \
85   TYPE(PureVirtualSpecifier)                                                   \
86   TYPE(RangeBasedForLoopColon)                                                 \
87   TYPE(RegexLiteral)                                                           \
88   TYPE(SelectorName)                                                           \
89   TYPE(StartOfName)                                                            \
90   TYPE(StatementMacro)                                                         \
91   TYPE(StructuredBindingLSquare)                                               \
92   TYPE(TemplateCloser)                                                         \
93   TYPE(TemplateOpener)                                                         \
94   TYPE(TemplateString)                                                         \
95   TYPE(ProtoExtensionLSquare)                                                  \
96   TYPE(TrailingAnnotation)                                                     \
97   TYPE(TrailingReturnArrow)                                                    \
98   TYPE(TrailingUnaryOperator)                                                  \
99   TYPE(UnaryOperator)                                                          \
100   TYPE(CSharpStringLiteral)                                                    \
101   TYPE(CSharpNullCoalescing)                                                   \
102   TYPE(Unknown)
103 
104 enum TokenType {
105 #define TYPE(X) TT_##X,
106   LIST_TOKEN_TYPES
107 #undef TYPE
108       NUM_TOKEN_TYPES
109 };
110 
111 /// Determines the name of a token type.
112 const char *getTokenTypeName(TokenType Type);
113 
114 // Represents what type of block a set of braces open.
115 enum BraceBlockKind { BK_Unknown, BK_Block, BK_BracedInit };
116 
117 // The packing kind of a function's parameters.
118 enum ParameterPackingKind { PPK_BinPacked, PPK_OnePerLine, PPK_Inconclusive };
119 
120 enum FormatDecision { FD_Unformatted, FD_Continue, FD_Break };
121 
122 class TokenRole;
123 class AnnotatedLine;
124 
125 /// A wrapper around a \c Token storing information about the
126 /// whitespace characters preceding it.
127 struct FormatToken {
128   FormatToken() {}
129 
130   /// The \c Token.
131   Token Tok;
132 
133   /// The number of newlines immediately before the \c Token.
134   ///
135   /// This can be used to determine what the user wrote in the original code
136   /// and thereby e.g. leave an empty line between two function definitions.
137   unsigned NewlinesBefore = 0;
138 
139   /// Whether there is at least one unescaped newline before the \c
140   /// Token.
141   bool HasUnescapedNewline = false;
142 
143   /// The range of the whitespace immediately preceding the \c Token.
144   SourceRange WhitespaceRange;
145 
146   /// The offset just past the last '\n' in this token's leading
147   /// whitespace (relative to \c WhiteSpaceStart). 0 if there is no '\n'.
148   unsigned LastNewlineOffset = 0;
149 
150   /// The width of the non-whitespace parts of the token (or its first
151   /// line for multi-line tokens) in columns.
152   /// We need this to correctly measure number of columns a token spans.
153   unsigned ColumnWidth = 0;
154 
155   /// Contains the width in columns of the last line of a multi-line
156   /// token.
157   unsigned LastLineColumnWidth = 0;
158 
159   /// Whether the token text contains newlines (escaped or not).
160   bool IsMultiline = false;
161 
162   /// Indicates that this is the first token of the file.
163   bool IsFirst = false;
164 
165   /// Whether there must be a line break before this token.
166   ///
167   /// This happens for example when a preprocessor directive ended directly
168   /// before the token.
169   bool MustBreakBefore = false;
170 
171   /// The raw text of the token.
172   ///
173   /// Contains the raw token text without leading whitespace and without leading
174   /// escaped newlines.
175   StringRef TokenText;
176 
177   /// Set to \c true if this token is an unterminated literal.
178   bool IsUnterminatedLiteral = 0;
179 
180   /// Contains the kind of block if this token is a brace.
181   BraceBlockKind BlockKind = BK_Unknown;
182 
183   TokenType Type = TT_Unknown;
184 
185   /// The number of spaces that should be inserted before this token.
186   unsigned SpacesRequiredBefore = 0;
187 
188   /// \c true if it is allowed to break before this token.
189   bool CanBreakBefore = false;
190 
191   /// \c true if this is the ">" of "template<..>".
192   bool ClosesTemplateDeclaration = false;
193 
194   /// Number of parameters, if this is "(", "[" or "<".
195   unsigned ParameterCount = 0;
196 
197   /// Number of parameters that are nested blocks,
198   /// if this is "(", "[" or "<".
199   unsigned BlockParameterCount = 0;
200 
201   /// If this is a bracket ("<", "(", "[" or "{"), contains the kind of
202   /// the surrounding bracket.
203   tok::TokenKind ParentBracket = tok::unknown;
204 
205   /// A token can have a special role that can carry extra information
206   /// about the token's formatting.
207   std::unique_ptr<TokenRole> Role;
208 
209   /// If this is an opening parenthesis, how are the parameters packed?
210   ParameterPackingKind PackingKind = PPK_Inconclusive;
211 
212   /// The total length of the unwrapped line up to and including this
213   /// token.
214   unsigned TotalLength = 0;
215 
216   /// The original 0-based column of this token, including expanded tabs.
217   /// The configured TabWidth is used as tab width.
218   unsigned OriginalColumn = 0;
219 
220   /// The length of following tokens until the next natural split point,
221   /// or the next token that can be broken.
222   unsigned UnbreakableTailLength = 0;
223 
224   // FIXME: Come up with a 'cleaner' concept.
225   /// The binding strength of a token. This is a combined value of
226   /// operator precedence, parenthesis nesting, etc.
227   unsigned BindingStrength = 0;
228 
229   /// The nesting level of this token, i.e. the number of surrounding (),
230   /// [], {} or <>.
231   unsigned NestingLevel = 0;
232 
233   /// The indent level of this token. Copied from the surrounding line.
234   unsigned IndentLevel = 0;
235 
236   /// Penalty for inserting a line break before this token.
237   unsigned SplitPenalty = 0;
238 
239   /// If this is the first ObjC selector name in an ObjC method
240   /// definition or call, this contains the length of the longest name.
241   ///
242   /// This being set to 0 means that the selectors should not be colon-aligned,
243   /// e.g. because several of them are block-type.
244   unsigned LongestObjCSelectorName = 0;
245 
246   /// If this is the first ObjC selector name in an ObjC method
247   /// definition or call, this contains the number of parts that the whole
248   /// selector consist of.
249   unsigned ObjCSelectorNameParts = 0;
250 
251   /// The 0-based index of the parameter/argument. For ObjC it is set
252   /// for the selector name token.
253   /// For now calculated only for ObjC.
254   unsigned ParameterIndex = 0;
255 
256   /// Stores the number of required fake parentheses and the
257   /// corresponding operator precedence.
258   ///
259   /// If multiple fake parentheses start at a token, this vector stores them in
260   /// reverse order, i.e. inner fake parenthesis first.
261   SmallVector<prec::Level, 4> FakeLParens;
262   /// Insert this many fake ) after this token for correct indentation.
263   unsigned FakeRParens = 0;
264 
265   /// \c true if this token starts a binary expression, i.e. has at least
266   /// one fake l_paren with a precedence greater than prec::Unknown.
267   bool StartsBinaryExpression = false;
268   /// \c true if this token ends a binary expression.
269   bool EndsBinaryExpression = false;
270 
271   /// If this is an operator (or "."/"->") in a sequence of operators
272   /// with the same precedence, contains the 0-based operator index.
273   unsigned OperatorIndex = 0;
274 
275   /// If this is an operator (or "."/"->") in a sequence of operators
276   /// with the same precedence, points to the next operator.
277   FormatToken *NextOperator = nullptr;
278 
279   /// Is this token part of a \c DeclStmt defining multiple variables?
280   ///
281   /// Only set if \c Type == \c TT_StartOfName.
282   bool PartOfMultiVariableDeclStmt = false;
283 
284   /// Does this line comment continue a line comment section?
285   ///
286   /// Only set to true if \c Type == \c TT_LineComment.
287   bool ContinuesLineCommentSection = false;
288 
289   /// If this is a bracket, this points to the matching one.
290   FormatToken *MatchingParen = nullptr;
291 
292   /// The previous token in the unwrapped line.
293   FormatToken *Previous = nullptr;
294 
295   /// The next token in the unwrapped line.
296   FormatToken *Next = nullptr;
297 
298   /// If this token starts a block, this contains all the unwrapped lines
299   /// in it.
300   SmallVector<AnnotatedLine *, 1> Children;
301 
302   /// Stores the formatting decision for the token once it was made.
303   FormatDecision Decision = FD_Unformatted;
304 
305   /// If \c true, this token has been fully formatted (indented and
306   /// potentially re-formatted inside), and we do not allow further formatting
307   /// changes.
308   bool Finalized = false;
309 
310   bool is(tok::TokenKind Kind) const { return Tok.is(Kind); }
311   bool is(TokenType TT) const { return Type == TT; }
312   bool is(const IdentifierInfo *II) const {
313     return II && II == Tok.getIdentifierInfo();
314   }
315   bool is(tok::PPKeywordKind Kind) const {
316     return Tok.getIdentifierInfo() &&
317            Tok.getIdentifierInfo()->getPPKeywordID() == Kind;
318   }
319   template <typename A, typename B> bool isOneOf(A K1, B K2) const {
320     return is(K1) || is(K2);
321   }
322   template <typename A, typename B, typename... Ts>
323   bool isOneOf(A K1, B K2, Ts... Ks) const {
324     return is(K1) || isOneOf(K2, Ks...);
325   }
326   template <typename T> bool isNot(T Kind) const { return !is(Kind); }
327 
328   bool closesScopeAfterBlock() const {
329     if (BlockKind == BK_Block)
330       return true;
331     if (closesScope())
332       return Previous->closesScopeAfterBlock();
333     return false;
334   }
335 
336   /// \c true if this token starts a sequence with the given tokens in order,
337   /// following the ``Next`` pointers, ignoring comments.
338   template <typename A, typename... Ts>
339   bool startsSequence(A K1, Ts... Tokens) const {
340     return startsSequenceInternal(K1, Tokens...);
341   }
342 
343   /// \c true if this token ends a sequence with the given tokens in order,
344   /// following the ``Previous`` pointers, ignoring comments.
345   template <typename A, typename... Ts>
346   bool endsSequence(A K1, Ts... Tokens) const {
347     return endsSequenceInternal(K1, Tokens...);
348   }
349 
350   bool isStringLiteral() const { return tok::isStringLiteral(Tok.getKind()); }
351 
352   bool isObjCAtKeyword(tok::ObjCKeywordKind Kind) const {
353     return Tok.isObjCAtKeyword(Kind);
354   }
355 
356   bool isAccessSpecifier(bool ColonRequired = true) const {
357     return isOneOf(tok::kw_public, tok::kw_protected, tok::kw_private) &&
358            (!ColonRequired || (Next && Next->is(tok::colon)));
359   }
360 
361   /// Determine whether the token is a simple-type-specifier.
362   bool isSimpleTypeSpecifier() const;
363 
364   bool isObjCAccessSpecifier() const {
365     return is(tok::at) && Next &&
366            (Next->isObjCAtKeyword(tok::objc_public) ||
367             Next->isObjCAtKeyword(tok::objc_protected) ||
368             Next->isObjCAtKeyword(tok::objc_package) ||
369             Next->isObjCAtKeyword(tok::objc_private));
370   }
371 
372   /// Returns whether \p Tok is ([{ or an opening < of a template or in
373   /// protos.
374   bool opensScope() const {
375     if (is(TT_TemplateString) && TokenText.endswith("${"))
376       return true;
377     if (is(TT_DictLiteral) && is(tok::less))
378       return true;
379     return isOneOf(tok::l_paren, tok::l_brace, tok::l_square,
380                    TT_TemplateOpener);
381   }
382   /// Returns whether \p Tok is )]} or a closing > of a template or in
383   /// protos.
384   bool closesScope() const {
385     if (is(TT_TemplateString) && TokenText.startswith("}"))
386       return true;
387     if (is(TT_DictLiteral) && is(tok::greater))
388       return true;
389     return isOneOf(tok::r_paren, tok::r_brace, tok::r_square,
390                    TT_TemplateCloser);
391   }
392 
393   /// Returns \c true if this is a "." or "->" accessing a member.
394   bool isMemberAccess() const {
395     return isOneOf(tok::arrow, tok::period, tok::arrowstar) &&
396            !isOneOf(TT_DesignatedInitializerPeriod, TT_TrailingReturnArrow,
397                     TT_LambdaArrow);
398   }
399 
400   bool isUnaryOperator() const {
401     switch (Tok.getKind()) {
402     case tok::plus:
403     case tok::plusplus:
404     case tok::minus:
405     case tok::minusminus:
406     case tok::exclaim:
407     case tok::tilde:
408     case tok::kw_sizeof:
409     case tok::kw_alignof:
410       return true;
411     default:
412       return false;
413     }
414   }
415 
416   bool isBinaryOperator() const {
417     // Comma is a binary operator, but does not behave as such wrt. formatting.
418     return getPrecedence() > prec::Comma;
419   }
420 
421   bool isTrailingComment() const {
422     return is(tok::comment) &&
423            (is(TT_LineComment) || !Next || Next->NewlinesBefore > 0);
424   }
425 
426   /// Returns \c true if this is a keyword that can be used
427   /// like a function call (e.g. sizeof, typeid, ...).
428   bool isFunctionLikeKeyword() const {
429     switch (Tok.getKind()) {
430     case tok::kw_throw:
431     case tok::kw_typeid:
432     case tok::kw_return:
433     case tok::kw_sizeof:
434     case tok::kw_alignof:
435     case tok::kw_alignas:
436     case tok::kw_decltype:
437     case tok::kw_noexcept:
438     case tok::kw_static_assert:
439     case tok::kw___attribute:
440       return true;
441     default:
442       return false;
443     }
444   }
445 
446   /// Returns \c true if this is a string literal that's like a label,
447   /// e.g. ends with "=" or ":".
448   bool isLabelString() const {
449     if (!is(tok::string_literal))
450       return false;
451     StringRef Content = TokenText;
452     if (Content.startswith("\"") || Content.startswith("'"))
453       Content = Content.drop_front(1);
454     if (Content.endswith("\"") || Content.endswith("'"))
455       Content = Content.drop_back(1);
456     Content = Content.trim();
457     return Content.size() > 1 &&
458            (Content.back() == ':' || Content.back() == '=');
459   }
460 
461   /// Returns actual token start location without leading escaped
462   /// newlines and whitespace.
463   ///
464   /// This can be different to Tok.getLocation(), which includes leading escaped
465   /// newlines.
466   SourceLocation getStartOfNonWhitespace() const {
467     return WhitespaceRange.getEnd();
468   }
469 
470   prec::Level getPrecedence() const {
471     return getBinOpPrecedence(Tok.getKind(), /*GreaterThanIsOperator=*/true,
472                               /*CPlusPlus11=*/true);
473   }
474 
475   /// Returns the previous token ignoring comments.
476   FormatToken *getPreviousNonComment() const {
477     FormatToken *Tok = Previous;
478     while (Tok && Tok->is(tok::comment))
479       Tok = Tok->Previous;
480     return Tok;
481   }
482 
483   /// Returns the next token ignoring comments.
484   const FormatToken *getNextNonComment() const {
485     const FormatToken *Tok = Next;
486     while (Tok && Tok->is(tok::comment))
487       Tok = Tok->Next;
488     return Tok;
489   }
490 
491   /// Returns \c true if this tokens starts a block-type list, i.e. a
492   /// list that should be indented with a block indent.
493   bool opensBlockOrBlockTypeList(const FormatStyle &Style) const {
494     if (is(TT_TemplateString) && opensScope())
495       return true;
496     return is(TT_ArrayInitializerLSquare) || is(TT_ProtoExtensionLSquare) ||
497            (is(tok::l_brace) &&
498             (BlockKind == BK_Block || is(TT_DictLiteral) ||
499              (!Style.Cpp11BracedListStyle && NestingLevel == 0))) ||
500            (is(tok::less) && (Style.Language == FormatStyle::LK_Proto ||
501                               Style.Language == FormatStyle::LK_TextProto));
502   }
503 
504   /// Returns whether the token is the left square bracket of a C++
505   /// structured binding declaration.
506   bool isCppStructuredBinding(const FormatStyle &Style) const {
507     if (!Style.isCpp() || isNot(tok::l_square))
508       return false;
509     const FormatToken *T = this;
510     do {
511       T = T->getPreviousNonComment();
512     } while (T && T->isOneOf(tok::kw_const, tok::kw_volatile, tok::amp,
513                              tok::ampamp));
514     return T && T->is(tok::kw_auto);
515   }
516 
517   /// Same as opensBlockOrBlockTypeList, but for the closing token.
518   bool closesBlockOrBlockTypeList(const FormatStyle &Style) const {
519     if (is(TT_TemplateString) && closesScope())
520       return true;
521     return MatchingParen && MatchingParen->opensBlockOrBlockTypeList(Style);
522   }
523 
524   /// Return the actual namespace token, if this token starts a namespace
525   /// block.
526   const FormatToken *getNamespaceToken() const {
527     const FormatToken *NamespaceTok = this;
528     if (is(tok::comment))
529       NamespaceTok = NamespaceTok->getNextNonComment();
530     // Detect "(inline|export)? namespace" in the beginning of a line.
531     if (NamespaceTok && NamespaceTok->isOneOf(tok::kw_inline, tok::kw_export))
532       NamespaceTok = NamespaceTok->getNextNonComment();
533     return NamespaceTok && NamespaceTok->is(tok::kw_namespace) ? NamespaceTok
534                                                                : nullptr;
535   }
536 
537 private:
538   // Disallow copying.
539   FormatToken(const FormatToken &) = delete;
540   void operator=(const FormatToken &) = delete;
541 
542   template <typename A, typename... Ts>
543   bool startsSequenceInternal(A K1, Ts... Tokens) const {
544     if (is(tok::comment) && Next)
545       return Next->startsSequenceInternal(K1, Tokens...);
546     return is(K1) && Next && Next->startsSequenceInternal(Tokens...);
547   }
548 
549   template <typename A> bool startsSequenceInternal(A K1) const {
550     if (is(tok::comment) && Next)
551       return Next->startsSequenceInternal(K1);
552     return is(K1);
553   }
554 
555   template <typename A, typename... Ts> bool endsSequenceInternal(A K1) const {
556     if (is(tok::comment) && Previous)
557       return Previous->endsSequenceInternal(K1);
558     return is(K1);
559   }
560 
561   template <typename A, typename... Ts>
562   bool endsSequenceInternal(A K1, Ts... Tokens) const {
563     if (is(tok::comment) && Previous)
564       return Previous->endsSequenceInternal(K1, Tokens...);
565     return is(K1) && Previous && Previous->endsSequenceInternal(Tokens...);
566   }
567 };
568 
569 class ContinuationIndenter;
570 struct LineState;
571 
572 class TokenRole {
573 public:
574   TokenRole(const FormatStyle &Style) : Style(Style) {}
575   virtual ~TokenRole();
576 
577   /// After the \c TokenAnnotator has finished annotating all the tokens,
578   /// this function precomputes required information for formatting.
579   virtual void precomputeFormattingInfos(const FormatToken *Token);
580 
581   /// Apply the special formatting that the given role demands.
582   ///
583   /// Assumes that the token having this role is already formatted.
584   ///
585   /// Continues formatting from \p State leaving indentation to \p Indenter and
586   /// returns the total penalty that this formatting incurs.
587   virtual unsigned formatFromToken(LineState &State,
588                                    ContinuationIndenter *Indenter,
589                                    bool DryRun) {
590     return 0;
591   }
592 
593   /// Same as \c formatFromToken, but assumes that the first token has
594   /// already been set thereby deciding on the first line break.
595   virtual unsigned formatAfterToken(LineState &State,
596                                     ContinuationIndenter *Indenter,
597                                     bool DryRun) {
598     return 0;
599   }
600 
601   /// Notifies the \c Role that a comma was found.
602   virtual void CommaFound(const FormatToken *Token) {}
603 
604   virtual const FormatToken *lastComma() { return nullptr; }
605 
606 protected:
607   const FormatStyle &Style;
608 };
609 
610 class CommaSeparatedList : public TokenRole {
611 public:
612   CommaSeparatedList(const FormatStyle &Style)
613       : TokenRole(Style), HasNestedBracedList(false) {}
614 
615   void precomputeFormattingInfos(const FormatToken *Token) override;
616 
617   unsigned formatAfterToken(LineState &State, ContinuationIndenter *Indenter,
618                             bool DryRun) override;
619 
620   unsigned formatFromToken(LineState &State, ContinuationIndenter *Indenter,
621                            bool DryRun) override;
622 
623   /// Adds \p Token as the next comma to the \c CommaSeparated list.
624   void CommaFound(const FormatToken *Token) override {
625     Commas.push_back(Token);
626   }
627 
628   const FormatToken *lastComma() override {
629     if (Commas.empty())
630       return nullptr;
631     return Commas.back();
632   }
633 
634 private:
635   /// A struct that holds information on how to format a given list with
636   /// a specific number of columns.
637   struct ColumnFormat {
638     /// The number of columns to use.
639     unsigned Columns;
640 
641     /// The total width in characters.
642     unsigned TotalWidth;
643 
644     /// The number of lines required for this format.
645     unsigned LineCount;
646 
647     /// The size of each column in characters.
648     SmallVector<unsigned, 8> ColumnSizes;
649   };
650 
651   /// Calculate which \c ColumnFormat fits best into
652   /// \p RemainingCharacters.
653   const ColumnFormat *getColumnFormat(unsigned RemainingCharacters) const;
654 
655   /// The ordered \c FormatTokens making up the commas of this list.
656   SmallVector<const FormatToken *, 8> Commas;
657 
658   /// The length of each of the list's items in characters including the
659   /// trailing comma.
660   SmallVector<unsigned, 8> ItemLengths;
661 
662   /// Precomputed formats that can be used for this list.
663   SmallVector<ColumnFormat, 4> Formats;
664 
665   bool HasNestedBracedList;
666 };
667 
668 /// Encapsulates keywords that are context sensitive or for languages not
669 /// properly supported by Clang's lexer.
670 struct AdditionalKeywords {
671   AdditionalKeywords(IdentifierTable &IdentTable) {
672     kw_final = &IdentTable.get("final");
673     kw_override = &IdentTable.get("override");
674     kw_in = &IdentTable.get("in");
675     kw_of = &IdentTable.get("of");
676     kw_CF_ENUM = &IdentTable.get("CF_ENUM");
677     kw_CF_OPTIONS = &IdentTable.get("CF_OPTIONS");
678     kw_NS_ENUM = &IdentTable.get("NS_ENUM");
679     kw_NS_OPTIONS = &IdentTable.get("NS_OPTIONS");
680 
681     kw_as = &IdentTable.get("as");
682     kw_async = &IdentTable.get("async");
683     kw_await = &IdentTable.get("await");
684     kw_declare = &IdentTable.get("declare");
685     kw_finally = &IdentTable.get("finally");
686     kw_from = &IdentTable.get("from");
687     kw_function = &IdentTable.get("function");
688     kw_get = &IdentTable.get("get");
689     kw_import = &IdentTable.get("import");
690     kw_infer = &IdentTable.get("infer");
691     kw_is = &IdentTable.get("is");
692     kw_let = &IdentTable.get("let");
693     kw_module = &IdentTable.get("module");
694     kw_readonly = &IdentTable.get("readonly");
695     kw_set = &IdentTable.get("set");
696     kw_type = &IdentTable.get("type");
697     kw_typeof = &IdentTable.get("typeof");
698     kw_var = &IdentTable.get("var");
699     kw_yield = &IdentTable.get("yield");
700 
701     kw_abstract = &IdentTable.get("abstract");
702     kw_assert = &IdentTable.get("assert");
703     kw_extends = &IdentTable.get("extends");
704     kw_implements = &IdentTable.get("implements");
705     kw_instanceof = &IdentTable.get("instanceof");
706     kw_interface = &IdentTable.get("interface");
707     kw_native = &IdentTable.get("native");
708     kw_package = &IdentTable.get("package");
709     kw_synchronized = &IdentTable.get("synchronized");
710     kw_throws = &IdentTable.get("throws");
711     kw___except = &IdentTable.get("__except");
712     kw___has_include = &IdentTable.get("__has_include");
713     kw___has_include_next = &IdentTable.get("__has_include_next");
714 
715     kw_mark = &IdentTable.get("mark");
716 
717     kw_extend = &IdentTable.get("extend");
718     kw_option = &IdentTable.get("option");
719     kw_optional = &IdentTable.get("optional");
720     kw_repeated = &IdentTable.get("repeated");
721     kw_required = &IdentTable.get("required");
722     kw_returns = &IdentTable.get("returns");
723 
724     kw_signals = &IdentTable.get("signals");
725     kw_qsignals = &IdentTable.get("Q_SIGNALS");
726     kw_slots = &IdentTable.get("slots");
727     kw_qslots = &IdentTable.get("Q_SLOTS");
728 
729     // C# keywords
730     kw_dollar = &IdentTable.get("dollar");
731     kw_base = &IdentTable.get("base");
732     kw_byte = &IdentTable.get("byte");
733     kw_checked = &IdentTable.get("checked");
734     kw_decimal = &IdentTable.get("decimal");
735     kw_delegate = &IdentTable.get("delegate");
736     kw_event = &IdentTable.get("event");
737     kw_fixed = &IdentTable.get("fixed");
738     kw_foreach = &IdentTable.get("foreach");
739     kw_implicit = &IdentTable.get("implicit");
740     kw_internal = &IdentTable.get("internal");
741     kw_lock = &IdentTable.get("lock");
742     kw_null = &IdentTable.get("null");
743     kw_object = &IdentTable.get("object");
744     kw_out = &IdentTable.get("out");
745     kw_params = &IdentTable.get("params");
746     kw_ref = &IdentTable.get("ref");
747     kw_string = &IdentTable.get("string");
748     kw_stackalloc = &IdentTable.get("stackalloc");
749     kw_sbyte = &IdentTable.get("sbyte");
750     kw_sealed = &IdentTable.get("sealed");
751     kw_uint = &IdentTable.get("uint");
752     kw_ulong = &IdentTable.get("ulong");
753     kw_unchecked = &IdentTable.get("unchecked");
754     kw_unsafe = &IdentTable.get("unsafe");
755     kw_ushort = &IdentTable.get("ushort");
756 
757     // Keep this at the end of the constructor to make sure everything here
758     // is
759     // already initialized.
760     JsExtraKeywords = std::unordered_set<IdentifierInfo *>(
761         {kw_as, kw_async, kw_await, kw_declare, kw_finally, kw_from,
762          kw_function, kw_get, kw_import, kw_is, kw_let, kw_module, kw_readonly,
763          kw_set, kw_type, kw_typeof, kw_var, kw_yield,
764          // Keywords from the Java section.
765          kw_abstract, kw_extends, kw_implements, kw_instanceof, kw_interface});
766 
767     CSharpExtraKeywords = std::unordered_set<IdentifierInfo *>(
768         {kw_base, kw_byte, kw_checked, kw_decimal, kw_delegate, kw_event,
769          kw_fixed, kw_foreach, kw_implicit, kw_in, kw_interface, kw_internal,
770          kw_is, kw_lock, kw_null, kw_object, kw_out, kw_override, kw_params,
771          kw_readonly, kw_ref, kw_string, kw_stackalloc, kw_sbyte, kw_sealed,
772          kw_uint, kw_ulong, kw_unchecked, kw_unsafe, kw_ushort,
773          // Keywords from the JavaScript section.
774          kw_as, kw_async, kw_await, kw_declare, kw_finally, kw_from,
775          kw_function, kw_get, kw_import, kw_is, kw_let, kw_module, kw_readonly,
776          kw_set, kw_type, kw_typeof, kw_var, kw_yield,
777          // Keywords from the Java section.
778          kw_abstract, kw_extends, kw_implements, kw_instanceof, kw_interface});
779   }
780 
781   // Context sensitive keywords.
782   IdentifierInfo *kw_final;
783   IdentifierInfo *kw_override;
784   IdentifierInfo *kw_in;
785   IdentifierInfo *kw_of;
786   IdentifierInfo *kw_CF_ENUM;
787   IdentifierInfo *kw_CF_OPTIONS;
788   IdentifierInfo *kw_NS_ENUM;
789   IdentifierInfo *kw_NS_OPTIONS;
790   IdentifierInfo *kw___except;
791   IdentifierInfo *kw___has_include;
792   IdentifierInfo *kw___has_include_next;
793 
794   // JavaScript keywords.
795   IdentifierInfo *kw_as;
796   IdentifierInfo *kw_async;
797   IdentifierInfo *kw_await;
798   IdentifierInfo *kw_declare;
799   IdentifierInfo *kw_finally;
800   IdentifierInfo *kw_from;
801   IdentifierInfo *kw_function;
802   IdentifierInfo *kw_get;
803   IdentifierInfo *kw_import;
804   IdentifierInfo *kw_infer;
805   IdentifierInfo *kw_is;
806   IdentifierInfo *kw_let;
807   IdentifierInfo *kw_module;
808   IdentifierInfo *kw_readonly;
809   IdentifierInfo *kw_set;
810   IdentifierInfo *kw_type;
811   IdentifierInfo *kw_typeof;
812   IdentifierInfo *kw_var;
813   IdentifierInfo *kw_yield;
814 
815   // Java keywords.
816   IdentifierInfo *kw_abstract;
817   IdentifierInfo *kw_assert;
818   IdentifierInfo *kw_extends;
819   IdentifierInfo *kw_implements;
820   IdentifierInfo *kw_instanceof;
821   IdentifierInfo *kw_interface;
822   IdentifierInfo *kw_native;
823   IdentifierInfo *kw_package;
824   IdentifierInfo *kw_synchronized;
825   IdentifierInfo *kw_throws;
826 
827   // Pragma keywords.
828   IdentifierInfo *kw_mark;
829 
830   // Proto keywords.
831   IdentifierInfo *kw_extend;
832   IdentifierInfo *kw_option;
833   IdentifierInfo *kw_optional;
834   IdentifierInfo *kw_repeated;
835   IdentifierInfo *kw_required;
836   IdentifierInfo *kw_returns;
837 
838   // QT keywords.
839   IdentifierInfo *kw_signals;
840   IdentifierInfo *kw_qsignals;
841   IdentifierInfo *kw_slots;
842   IdentifierInfo *kw_qslots;
843 
844   // C# keywords
845   IdentifierInfo *kw_dollar;
846   IdentifierInfo *kw_base;
847   IdentifierInfo *kw_byte;
848   IdentifierInfo *kw_checked;
849   IdentifierInfo *kw_decimal;
850   IdentifierInfo *kw_delegate;
851   IdentifierInfo *kw_event;
852   IdentifierInfo *kw_fixed;
853   IdentifierInfo *kw_foreach;
854   IdentifierInfo *kw_implicit;
855   IdentifierInfo *kw_internal;
856 
857   IdentifierInfo *kw_lock;
858   IdentifierInfo *kw_null;
859   IdentifierInfo *kw_object;
860   IdentifierInfo *kw_out;
861 
862   IdentifierInfo *kw_params;
863 
864   IdentifierInfo *kw_ref;
865   IdentifierInfo *kw_string;
866   IdentifierInfo *kw_stackalloc;
867   IdentifierInfo *kw_sbyte;
868   IdentifierInfo *kw_sealed;
869   IdentifierInfo *kw_uint;
870   IdentifierInfo *kw_ulong;
871   IdentifierInfo *kw_unchecked;
872   IdentifierInfo *kw_unsafe;
873   IdentifierInfo *kw_ushort;
874 
875   /// Returns \c true if \p Tok is a true JavaScript identifier, returns
876   /// \c false if it is a keyword or a pseudo keyword.
877   bool IsJavaScriptIdentifier(const FormatToken &Tok) const {
878     return Tok.is(tok::identifier) &&
879            JsExtraKeywords.find(Tok.Tok.getIdentifierInfo()) ==
880                JsExtraKeywords.end();
881   }
882 
883   /// Returns \c true if \p Tok is a C# keyword, returns
884   /// \c false if it is a anything else.
885   bool isCSharpKeyword(const FormatToken &Tok) const {
886     switch (Tok.Tok.getKind()) {
887     case tok::kw_bool:
888     case tok::kw_break:
889     case tok::kw_case:
890     case tok::kw_catch:
891     case tok::kw_char:
892     case tok::kw_class:
893     case tok::kw_const:
894     case tok::kw_continue:
895     case tok::kw_default:
896     case tok::kw_do:
897     case tok::kw_double:
898     case tok::kw_else:
899     case tok::kw_enum:
900     case tok::kw_explicit:
901     case tok::kw_extern:
902     case tok::kw_false:
903     case tok::kw_float:
904     case tok::kw_for:
905     case tok::kw_goto:
906     case tok::kw_if:
907     case tok::kw_int:
908     case tok::kw_long:
909     case tok::kw_namespace:
910     case tok::kw_new:
911     case tok::kw_operator:
912     case tok::kw_private:
913     case tok::kw_protected:
914     case tok::kw_public:
915     case tok::kw_return:
916     case tok::kw_short:
917     case tok::kw_sizeof:
918     case tok::kw_static:
919     case tok::kw_struct:
920     case tok::kw_switch:
921     case tok::kw_this:
922     case tok::kw_throw:
923     case tok::kw_true:
924     case tok::kw_try:
925     case tok::kw_typeof:
926     case tok::kw_using:
927     case tok::kw_virtual:
928     case tok::kw_void:
929     case tok::kw_volatile:
930     case tok::kw_while:
931       return true;
932     default:
933       return Tok.is(tok::identifier) &&
934              CSharpExtraKeywords.find(Tok.Tok.getIdentifierInfo()) ==
935                  CSharpExtraKeywords.end();
936     }
937   }
938 
939 private:
940   /// The JavaScript keywords beyond the C++ keyword set.
941   std::unordered_set<IdentifierInfo *> JsExtraKeywords;
942 
943   /// The C# keywords beyond the C++ keyword set
944   std::unordered_set<IdentifierInfo *> CSharpExtraKeywords;
945 };
946 
947 } // namespace format
948 } // namespace clang
949 
950 #endif
951