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(InlineASMSymbolicNameLSquare)                                           \
58   TYPE(JavaAnnotation)                                                         \
59   TYPE(JsComputedPropertyName)                                                 \
60   TYPE(JsExponentiation)                                                       \
61   TYPE(JsExponentiationEqual)                                                  \
62   TYPE(JsFatArrow)                                                             \
63   TYPE(JsNonNullAssertion)                                                     \
64   TYPE(JsNullishCoalescingOperator)                                            \
65   TYPE(JsNullPropagatingOperator)                                              \
66   TYPE(JsPrivateIdentifier)                                                    \
67   TYPE(JsTypeColon)                                                            \
68   TYPE(JsTypeOperator)                                                         \
69   TYPE(JsTypeOptionalQuestion)                                                 \
70   TYPE(LambdaArrow)                                                            \
71   TYPE(LambdaLBrace)                                                           \
72   TYPE(LambdaLSquare)                                                          \
73   TYPE(LeadingJavaAnnotation)                                                  \
74   TYPE(LineComment)                                                            \
75   TYPE(MacroBlockBegin)                                                        \
76   TYPE(MacroBlockEnd)                                                          \
77   TYPE(NamespaceMacro)                                                         \
78   TYPE(ObjCBlockLBrace)                                                        \
79   TYPE(ObjCBlockLParen)                                                        \
80   TYPE(ObjCDecl)                                                               \
81   TYPE(ObjCForIn)                                                              \
82   TYPE(ObjCMethodExpr)                                                         \
83   TYPE(ObjCMethodSpecifier)                                                    \
84   TYPE(ObjCProperty)                                                           \
85   TYPE(ObjCStringLiteral)                                                      \
86   TYPE(OverloadedOperator)                                                     \
87   TYPE(OverloadedOperatorLParen)                                               \
88   TYPE(PointerOrReference)                                                     \
89   TYPE(PureVirtualSpecifier)                                                   \
90   TYPE(RangeBasedForLoopColon)                                                 \
91   TYPE(RegexLiteral)                                                           \
92   TYPE(SelectorName)                                                           \
93   TYPE(StartOfName)                                                            \
94   TYPE(StatementMacro)                                                         \
95   TYPE(StructuredBindingLSquare)                                               \
96   TYPE(TemplateCloser)                                                         \
97   TYPE(TemplateOpener)                                                         \
98   TYPE(TemplateString)                                                         \
99   TYPE(ProtoExtensionLSquare)                                                  \
100   TYPE(TrailingAnnotation)                                                     \
101   TYPE(TrailingReturnArrow)                                                    \
102   TYPE(TrailingUnaryOperator)                                                  \
103   TYPE(TypenameMacro)                                                          \
104   TYPE(UnaryOperator)                                                          \
105   TYPE(CSharpStringLiteral)                                                    \
106   TYPE(CSharpNamedArgumentColon)                                               \
107   TYPE(CSharpNullable)                                                         \
108   TYPE(CSharpNullCoalescing)                                                   \
109   TYPE(CSharpNullConditional)                                                  \
110   TYPE(CSharpNullConditionalLSquare)                                           \
111   TYPE(CSharpGenericTypeConstraint)                                            \
112   TYPE(CSharpGenericTypeConstraintColon)                                       \
113   TYPE(CSharpGenericTypeConstraintComma)                                       \
114   TYPE(Unknown)
115 
116 enum TokenType {
117 #define TYPE(X) TT_##X,
118   LIST_TOKEN_TYPES
119 #undef TYPE
120       NUM_TOKEN_TYPES
121 };
122 
123 /// Determines the name of a token type.
124 const char *getTokenTypeName(TokenType Type);
125 
126 // Represents what type of block a set of braces open.
127 enum BraceBlockKind { BK_Unknown, BK_Block, BK_BracedInit };
128 
129 // The packing kind of a function's parameters.
130 enum ParameterPackingKind { PPK_BinPacked, PPK_OnePerLine, PPK_Inconclusive };
131 
132 enum FormatDecision { FD_Unformatted, FD_Continue, FD_Break };
133 
134 class TokenRole;
135 class AnnotatedLine;
136 
137 /// A wrapper around a \c Token storing information about the
138 /// whitespace characters preceding it.
139 struct FormatToken {
140   FormatToken() {}
141 
142   /// The \c Token.
143   Token Tok;
144 
145   /// The number of newlines immediately before the \c Token.
146   ///
147   /// This can be used to determine what the user wrote in the original code
148   /// and thereby e.g. leave an empty line between two function definitions.
149   unsigned NewlinesBefore = 0;
150 
151   /// Whether there is at least one unescaped newline before the \c
152   /// Token.
153   bool HasUnescapedNewline = false;
154 
155   /// The range of the whitespace immediately preceding the \c Token.
156   SourceRange WhitespaceRange;
157 
158   /// The offset just past the last '\n' in this token's leading
159   /// whitespace (relative to \c WhiteSpaceStart). 0 if there is no '\n'.
160   unsigned LastNewlineOffset = 0;
161 
162   /// The width of the non-whitespace parts of the token (or its first
163   /// line for multi-line tokens) in columns.
164   /// We need this to correctly measure number of columns a token spans.
165   unsigned ColumnWidth = 0;
166 
167   /// Contains the width in columns of the last line of a multi-line
168   /// token.
169   unsigned LastLineColumnWidth = 0;
170 
171   /// Whether the token text contains newlines (escaped or not).
172   bool IsMultiline = false;
173 
174   /// Indicates that this is the first token of the file.
175   bool IsFirst = false;
176 
177   /// Whether there must be a line break before this token.
178   ///
179   /// This happens for example when a preprocessor directive ended directly
180   /// before the token.
181   bool MustBreakBefore = false;
182 
183   /// The raw text of the token.
184   ///
185   /// Contains the raw token text without leading whitespace and without leading
186   /// escaped newlines.
187   StringRef TokenText;
188 
189   /// Set to \c true if this token is an unterminated literal.
190   bool IsUnterminatedLiteral = 0;
191 
192   /// Contains the kind of block if this token is a brace.
193   BraceBlockKind BlockKind = BK_Unknown;
194 
195   TokenType Type = TT_Unknown;
196 
197   /// The number of spaces that should be inserted before this token.
198   unsigned SpacesRequiredBefore = 0;
199 
200   /// \c true if it is allowed to break before this token.
201   bool CanBreakBefore = false;
202 
203   /// \c true if this is the ">" of "template<..>".
204   bool ClosesTemplateDeclaration = false;
205 
206   /// Number of parameters, if this is "(", "[" or "<".
207   unsigned ParameterCount = 0;
208 
209   /// Number of parameters that are nested blocks,
210   /// if this is "(", "[" or "<".
211   unsigned BlockParameterCount = 0;
212 
213   /// If this is a bracket ("<", "(", "[" or "{"), contains the kind of
214   /// the surrounding bracket.
215   tok::TokenKind ParentBracket = tok::unknown;
216 
217   /// A token can have a special role that can carry extra information
218   /// about the token's formatting.
219   std::unique_ptr<TokenRole> Role;
220 
221   /// If this is an opening parenthesis, how are the parameters packed?
222   ParameterPackingKind PackingKind = PPK_Inconclusive;
223 
224   /// The total length of the unwrapped line up to and including this
225   /// token.
226   unsigned TotalLength = 0;
227 
228   /// The original 0-based column of this token, including expanded tabs.
229   /// The configured TabWidth is used as tab width.
230   unsigned OriginalColumn = 0;
231 
232   /// The length of following tokens until the next natural split point,
233   /// or the next token that can be broken.
234   unsigned UnbreakableTailLength = 0;
235 
236   // FIXME: Come up with a 'cleaner' concept.
237   /// The binding strength of a token. This is a combined value of
238   /// operator precedence, parenthesis nesting, etc.
239   unsigned BindingStrength = 0;
240 
241   /// The nesting level of this token, i.e. the number of surrounding (),
242   /// [], {} or <>.
243   unsigned NestingLevel = 0;
244 
245   /// The indent level of this token. Copied from the surrounding line.
246   unsigned IndentLevel = 0;
247 
248   /// Penalty for inserting a line break before this token.
249   unsigned SplitPenalty = 0;
250 
251   /// If this is the first ObjC selector name in an ObjC method
252   /// definition or call, this contains the length of the longest name.
253   ///
254   /// This being set to 0 means that the selectors should not be colon-aligned,
255   /// e.g. because several of them are block-type.
256   unsigned LongestObjCSelectorName = 0;
257 
258   /// If this is the first ObjC selector name in an ObjC method
259   /// definition or call, this contains the number of parts that the whole
260   /// selector consist of.
261   unsigned ObjCSelectorNameParts = 0;
262 
263   /// The 0-based index of the parameter/argument. For ObjC it is set
264   /// for the selector name token.
265   /// For now calculated only for ObjC.
266   unsigned ParameterIndex = 0;
267 
268   /// Stores the number of required fake parentheses and the
269   /// corresponding operator precedence.
270   ///
271   /// If multiple fake parentheses start at a token, this vector stores them in
272   /// reverse order, i.e. inner fake parenthesis first.
273   SmallVector<prec::Level, 4> FakeLParens;
274   /// Insert this many fake ) after this token for correct indentation.
275   unsigned FakeRParens = 0;
276 
277   /// \c true if this token starts a binary expression, i.e. has at least
278   /// one fake l_paren with a precedence greater than prec::Unknown.
279   bool StartsBinaryExpression = false;
280   /// \c true if this token ends a binary expression.
281   bool EndsBinaryExpression = false;
282 
283   /// If this is an operator (or "."/"->") in a sequence of operators
284   /// with the same precedence, contains the 0-based operator index.
285   unsigned OperatorIndex = 0;
286 
287   /// If this is an operator (or "."/"->") in a sequence of operators
288   /// with the same precedence, points to the next operator.
289   FormatToken *NextOperator = nullptr;
290 
291   /// Is this token part of a \c DeclStmt defining multiple variables?
292   ///
293   /// Only set if \c Type == \c TT_StartOfName.
294   bool PartOfMultiVariableDeclStmt = false;
295 
296   /// Does this line comment continue a line comment section?
297   ///
298   /// Only set to true if \c Type == \c TT_LineComment.
299   bool ContinuesLineCommentSection = false;
300 
301   /// If this is a bracket, this points to the matching one.
302   FormatToken *MatchingParen = nullptr;
303 
304   /// The previous token in the unwrapped line.
305   FormatToken *Previous = nullptr;
306 
307   /// The next token in the unwrapped line.
308   FormatToken *Next = nullptr;
309 
310   /// If this token starts a block, this contains all the unwrapped lines
311   /// in it.
312   SmallVector<AnnotatedLine *, 1> Children;
313 
314   /// Stores the formatting decision for the token once it was made.
315   FormatDecision Decision = FD_Unformatted;
316 
317   /// If \c true, this token has been fully formatted (indented and
318   /// potentially re-formatted inside), and we do not allow further formatting
319   /// changes.
320   bool Finalized = false;
321 
322   bool is(tok::TokenKind Kind) const { return Tok.is(Kind); }
323   bool is(TokenType TT) const { return Type == TT; }
324   bool is(const IdentifierInfo *II) const {
325     return II && II == Tok.getIdentifierInfo();
326   }
327   bool is(tok::PPKeywordKind Kind) const {
328     return Tok.getIdentifierInfo() &&
329            Tok.getIdentifierInfo()->getPPKeywordID() == Kind;
330   }
331   template <typename A, typename B> bool isOneOf(A K1, B K2) const {
332     return is(K1) || is(K2);
333   }
334   template <typename A, typename B, typename... Ts>
335   bool isOneOf(A K1, B K2, Ts... Ks) const {
336     return is(K1) || isOneOf(K2, Ks...);
337   }
338   template <typename T> bool isNot(T Kind) const { return !is(Kind); }
339 
340   bool isIf(bool AllowConstexprMacro = true) const {
341     return is(tok::kw_if) || endsSequence(tok::kw_constexpr, tok::kw_if) ||
342            (endsSequence(tok::identifier, tok::kw_if) && AllowConstexprMacro);
343   }
344 
345   bool closesScopeAfterBlock() const {
346     if (BlockKind == BK_Block)
347       return true;
348     if (closesScope())
349       return Previous->closesScopeAfterBlock();
350     return false;
351   }
352 
353   /// \c true if this token starts a sequence with the given tokens in order,
354   /// following the ``Next`` pointers, ignoring comments.
355   template <typename A, typename... Ts>
356   bool startsSequence(A K1, Ts... Tokens) const {
357     return startsSequenceInternal(K1, Tokens...);
358   }
359 
360   /// \c true if this token ends a sequence with the given tokens in order,
361   /// following the ``Previous`` pointers, ignoring comments.
362   /// For example, given tokens [T1, T2, T3], the function returns true if
363   /// 3 tokens ending at this (ignoring comments) are [T3, T2, T1]. In other
364   /// words, the tokens passed to this function need to the reverse of the
365   /// order the tokens appear in code.
366   template <typename A, typename... Ts>
367   bool endsSequence(A K1, Ts... Tokens) const {
368     return endsSequenceInternal(K1, Tokens...);
369   }
370 
371   bool isStringLiteral() const { return tok::isStringLiteral(Tok.getKind()); }
372 
373   bool isObjCAtKeyword(tok::ObjCKeywordKind Kind) const {
374     return Tok.isObjCAtKeyword(Kind);
375   }
376 
377   bool isAccessSpecifier(bool ColonRequired = true) const {
378     return isOneOf(tok::kw_public, tok::kw_protected, tok::kw_private) &&
379            (!ColonRequired || (Next && Next->is(tok::colon)));
380   }
381 
382   /// Determine whether the token is a simple-type-specifier.
383   bool isSimpleTypeSpecifier() const;
384 
385   bool isObjCAccessSpecifier() const {
386     return is(tok::at) && Next &&
387            (Next->isObjCAtKeyword(tok::objc_public) ||
388             Next->isObjCAtKeyword(tok::objc_protected) ||
389             Next->isObjCAtKeyword(tok::objc_package) ||
390             Next->isObjCAtKeyword(tok::objc_private));
391   }
392 
393   /// Returns whether \p Tok is ([{ or an opening < of a template or in
394   /// protos.
395   bool opensScope() const {
396     if (is(TT_TemplateString) && TokenText.endswith("${"))
397       return true;
398     if (is(TT_DictLiteral) && is(tok::less))
399       return true;
400     return isOneOf(tok::l_paren, tok::l_brace, tok::l_square,
401                    TT_TemplateOpener);
402   }
403   /// Returns whether \p Tok is )]} or a closing > of a template or in
404   /// protos.
405   bool closesScope() const {
406     if (is(TT_TemplateString) && TokenText.startswith("}"))
407       return true;
408     if (is(TT_DictLiteral) && is(tok::greater))
409       return true;
410     return isOneOf(tok::r_paren, tok::r_brace, tok::r_square,
411                    TT_TemplateCloser);
412   }
413 
414   /// Returns \c true if this is a "." or "->" accessing a member.
415   bool isMemberAccess() const {
416     return isOneOf(tok::arrow, tok::period, tok::arrowstar) &&
417            !isOneOf(TT_DesignatedInitializerPeriod, TT_TrailingReturnArrow,
418                     TT_LambdaArrow, TT_LeadingJavaAnnotation);
419   }
420 
421   bool isUnaryOperator() const {
422     switch (Tok.getKind()) {
423     case tok::plus:
424     case tok::plusplus:
425     case tok::minus:
426     case tok::minusminus:
427     case tok::exclaim:
428     case tok::tilde:
429     case tok::kw_sizeof:
430     case tok::kw_alignof:
431       return true;
432     default:
433       return false;
434     }
435   }
436 
437   bool isBinaryOperator() const {
438     // Comma is a binary operator, but does not behave as such wrt. formatting.
439     return getPrecedence() > prec::Comma;
440   }
441 
442   bool isTrailingComment() const {
443     return is(tok::comment) &&
444            (is(TT_LineComment) || !Next || Next->NewlinesBefore > 0);
445   }
446 
447   /// Returns \c true if this is a keyword that can be used
448   /// like a function call (e.g. sizeof, typeid, ...).
449   bool isFunctionLikeKeyword() const {
450     switch (Tok.getKind()) {
451     case tok::kw_throw:
452     case tok::kw_typeid:
453     case tok::kw_return:
454     case tok::kw_sizeof:
455     case tok::kw_alignof:
456     case tok::kw_alignas:
457     case tok::kw_decltype:
458     case tok::kw_noexcept:
459     case tok::kw_static_assert:
460     case tok::kw___attribute:
461       return true;
462     default:
463       return false;
464     }
465   }
466 
467   /// Returns \c true if this is a string literal that's like a label,
468   /// e.g. ends with "=" or ":".
469   bool isLabelString() const {
470     if (!is(tok::string_literal))
471       return false;
472     StringRef Content = TokenText;
473     if (Content.startswith("\"") || Content.startswith("'"))
474       Content = Content.drop_front(1);
475     if (Content.endswith("\"") || Content.endswith("'"))
476       Content = Content.drop_back(1);
477     Content = Content.trim();
478     return Content.size() > 1 &&
479            (Content.back() == ':' || Content.back() == '=');
480   }
481 
482   /// Returns actual token start location without leading escaped
483   /// newlines and whitespace.
484   ///
485   /// This can be different to Tok.getLocation(), which includes leading escaped
486   /// newlines.
487   SourceLocation getStartOfNonWhitespace() const {
488     return WhitespaceRange.getEnd();
489   }
490 
491   prec::Level getPrecedence() const {
492     return getBinOpPrecedence(Tok.getKind(), /*GreaterThanIsOperator=*/true,
493                               /*CPlusPlus11=*/true);
494   }
495 
496   /// Returns the previous token ignoring comments.
497   FormatToken *getPreviousNonComment() const {
498     FormatToken *Tok = Previous;
499     while (Tok && Tok->is(tok::comment))
500       Tok = Tok->Previous;
501     return Tok;
502   }
503 
504   /// Returns the next token ignoring comments.
505   const FormatToken *getNextNonComment() const {
506     const FormatToken *Tok = Next;
507     while (Tok && Tok->is(tok::comment))
508       Tok = Tok->Next;
509     return Tok;
510   }
511 
512   /// Returns \c true if this tokens starts a block-type list, i.e. a
513   /// list that should be indented with a block indent.
514   bool opensBlockOrBlockTypeList(const FormatStyle &Style) const {
515     // C# Does not indent object initialisers as continuations.
516     if (is(tok::l_brace) && BlockKind == BK_BracedInit && Style.isCSharp())
517       return true;
518     if (is(TT_TemplateString) && opensScope())
519       return true;
520     return is(TT_ArrayInitializerLSquare) || is(TT_ProtoExtensionLSquare) ||
521            (is(tok::l_brace) &&
522             (BlockKind == BK_Block || is(TT_DictLiteral) ||
523              (!Style.Cpp11BracedListStyle && NestingLevel == 0))) ||
524            (is(tok::less) && (Style.Language == FormatStyle::LK_Proto ||
525                               Style.Language == FormatStyle::LK_TextProto));
526   }
527 
528   /// Returns whether the token is the left square bracket of a C++
529   /// structured binding declaration.
530   bool isCppStructuredBinding(const FormatStyle &Style) const {
531     if (!Style.isCpp() || isNot(tok::l_square))
532       return false;
533     const FormatToken *T = this;
534     do {
535       T = T->getPreviousNonComment();
536     } while (T && T->isOneOf(tok::kw_const, tok::kw_volatile, tok::amp,
537                              tok::ampamp));
538     return T && T->is(tok::kw_auto);
539   }
540 
541   /// Same as opensBlockOrBlockTypeList, but for the closing token.
542   bool closesBlockOrBlockTypeList(const FormatStyle &Style) const {
543     if (is(TT_TemplateString) && closesScope())
544       return true;
545     return MatchingParen && MatchingParen->opensBlockOrBlockTypeList(Style);
546   }
547 
548   /// Return the actual namespace token, if this token starts a namespace
549   /// block.
550   const FormatToken *getNamespaceToken() const {
551     const FormatToken *NamespaceTok = this;
552     if (is(tok::comment))
553       NamespaceTok = NamespaceTok->getNextNonComment();
554     // Detect "(inline|export)? namespace" in the beginning of a line.
555     if (NamespaceTok && NamespaceTok->isOneOf(tok::kw_inline, tok::kw_export))
556       NamespaceTok = NamespaceTok->getNextNonComment();
557     return NamespaceTok &&
558                    NamespaceTok->isOneOf(tok::kw_namespace, TT_NamespaceMacro)
559                ? NamespaceTok
560                : nullptr;
561   }
562 
563 private:
564   // Disallow copying.
565   FormatToken(const FormatToken &) = delete;
566   void operator=(const FormatToken &) = delete;
567 
568   template <typename A, typename... Ts>
569   bool startsSequenceInternal(A K1, Ts... Tokens) const {
570     if (is(tok::comment) && Next)
571       return Next->startsSequenceInternal(K1, Tokens...);
572     return is(K1) && Next && Next->startsSequenceInternal(Tokens...);
573   }
574 
575   template <typename A> bool startsSequenceInternal(A K1) const {
576     if (is(tok::comment) && Next)
577       return Next->startsSequenceInternal(K1);
578     return is(K1);
579   }
580 
581   template <typename A, typename... Ts> bool endsSequenceInternal(A K1) const {
582     if (is(tok::comment) && Previous)
583       return Previous->endsSequenceInternal(K1);
584     return is(K1);
585   }
586 
587   template <typename A, typename... Ts>
588   bool endsSequenceInternal(A K1, Ts... Tokens) const {
589     if (is(tok::comment) && Previous)
590       return Previous->endsSequenceInternal(K1, Tokens...);
591     return is(K1) && Previous && Previous->endsSequenceInternal(Tokens...);
592   }
593 };
594 
595 class ContinuationIndenter;
596 struct LineState;
597 
598 class TokenRole {
599 public:
600   TokenRole(const FormatStyle &Style) : Style(Style) {}
601   virtual ~TokenRole();
602 
603   /// After the \c TokenAnnotator has finished annotating all the tokens,
604   /// this function precomputes required information for formatting.
605   virtual void precomputeFormattingInfos(const FormatToken *Token);
606 
607   /// Apply the special formatting that the given role demands.
608   ///
609   /// Assumes that the token having this role is already formatted.
610   ///
611   /// Continues formatting from \p State leaving indentation to \p Indenter and
612   /// returns the total penalty that this formatting incurs.
613   virtual unsigned formatFromToken(LineState &State,
614                                    ContinuationIndenter *Indenter,
615                                    bool DryRun) {
616     return 0;
617   }
618 
619   /// Same as \c formatFromToken, but assumes that the first token has
620   /// already been set thereby deciding on the first line break.
621   virtual unsigned formatAfterToken(LineState &State,
622                                     ContinuationIndenter *Indenter,
623                                     bool DryRun) {
624     return 0;
625   }
626 
627   /// Notifies the \c Role that a comma was found.
628   virtual void CommaFound(const FormatToken *Token) {}
629 
630   virtual const FormatToken *lastComma() { return nullptr; }
631 
632 protected:
633   const FormatStyle &Style;
634 };
635 
636 class CommaSeparatedList : public TokenRole {
637 public:
638   CommaSeparatedList(const FormatStyle &Style)
639       : TokenRole(Style), HasNestedBracedList(false) {}
640 
641   void precomputeFormattingInfos(const FormatToken *Token) override;
642 
643   unsigned formatAfterToken(LineState &State, ContinuationIndenter *Indenter,
644                             bool DryRun) override;
645 
646   unsigned formatFromToken(LineState &State, ContinuationIndenter *Indenter,
647                            bool DryRun) override;
648 
649   /// Adds \p Token as the next comma to the \c CommaSeparated list.
650   void CommaFound(const FormatToken *Token) override {
651     Commas.push_back(Token);
652   }
653 
654   const FormatToken *lastComma() override {
655     if (Commas.empty())
656       return nullptr;
657     return Commas.back();
658   }
659 
660 private:
661   /// A struct that holds information on how to format a given list with
662   /// a specific number of columns.
663   struct ColumnFormat {
664     /// The number of columns to use.
665     unsigned Columns;
666 
667     /// The total width in characters.
668     unsigned TotalWidth;
669 
670     /// The number of lines required for this format.
671     unsigned LineCount;
672 
673     /// The size of each column in characters.
674     SmallVector<unsigned, 8> ColumnSizes;
675   };
676 
677   /// Calculate which \c ColumnFormat fits best into
678   /// \p RemainingCharacters.
679   const ColumnFormat *getColumnFormat(unsigned RemainingCharacters) const;
680 
681   /// The ordered \c FormatTokens making up the commas of this list.
682   SmallVector<const FormatToken *, 8> Commas;
683 
684   /// The length of each of the list's items in characters including the
685   /// trailing comma.
686   SmallVector<unsigned, 8> ItemLengths;
687 
688   /// Precomputed formats that can be used for this list.
689   SmallVector<ColumnFormat, 4> Formats;
690 
691   bool HasNestedBracedList;
692 };
693 
694 /// Encapsulates keywords that are context sensitive or for languages not
695 /// properly supported by Clang's lexer.
696 struct AdditionalKeywords {
697   AdditionalKeywords(IdentifierTable &IdentTable) {
698     kw_final = &IdentTable.get("final");
699     kw_override = &IdentTable.get("override");
700     kw_in = &IdentTable.get("in");
701     kw_of = &IdentTable.get("of");
702     kw_CF_CLOSED_ENUM = &IdentTable.get("CF_CLOSED_ENUM");
703     kw_CF_ENUM = &IdentTable.get("CF_ENUM");
704     kw_CF_OPTIONS = &IdentTable.get("CF_OPTIONS");
705     kw_NS_CLOSED_ENUM = &IdentTable.get("NS_CLOSED_ENUM");
706     kw_NS_ENUM = &IdentTable.get("NS_ENUM");
707     kw_NS_OPTIONS = &IdentTable.get("NS_OPTIONS");
708 
709     kw_as = &IdentTable.get("as");
710     kw_async = &IdentTable.get("async");
711     kw_await = &IdentTable.get("await");
712     kw_declare = &IdentTable.get("declare");
713     kw_finally = &IdentTable.get("finally");
714     kw_from = &IdentTable.get("from");
715     kw_function = &IdentTable.get("function");
716     kw_get = &IdentTable.get("get");
717     kw_import = &IdentTable.get("import");
718     kw_infer = &IdentTable.get("infer");
719     kw_is = &IdentTable.get("is");
720     kw_let = &IdentTable.get("let");
721     kw_module = &IdentTable.get("module");
722     kw_readonly = &IdentTable.get("readonly");
723     kw_set = &IdentTable.get("set");
724     kw_type = &IdentTable.get("type");
725     kw_typeof = &IdentTable.get("typeof");
726     kw_var = &IdentTable.get("var");
727     kw_yield = &IdentTable.get("yield");
728 
729     kw_abstract = &IdentTable.get("abstract");
730     kw_assert = &IdentTable.get("assert");
731     kw_extends = &IdentTable.get("extends");
732     kw_implements = &IdentTable.get("implements");
733     kw_instanceof = &IdentTable.get("instanceof");
734     kw_interface = &IdentTable.get("interface");
735     kw_native = &IdentTable.get("native");
736     kw_package = &IdentTable.get("package");
737     kw_synchronized = &IdentTable.get("synchronized");
738     kw_throws = &IdentTable.get("throws");
739     kw___except = &IdentTable.get("__except");
740     kw___has_include = &IdentTable.get("__has_include");
741     kw___has_include_next = &IdentTable.get("__has_include_next");
742 
743     kw_mark = &IdentTable.get("mark");
744 
745     kw_extend = &IdentTable.get("extend");
746     kw_option = &IdentTable.get("option");
747     kw_optional = &IdentTable.get("optional");
748     kw_repeated = &IdentTable.get("repeated");
749     kw_required = &IdentTable.get("required");
750     kw_returns = &IdentTable.get("returns");
751 
752     kw_signals = &IdentTable.get("signals");
753     kw_qsignals = &IdentTable.get("Q_SIGNALS");
754     kw_slots = &IdentTable.get("slots");
755     kw_qslots = &IdentTable.get("Q_SLOTS");
756 
757     // C# keywords
758     kw_dollar = &IdentTable.get("dollar");
759     kw_base = &IdentTable.get("base");
760     kw_byte = &IdentTable.get("byte");
761     kw_checked = &IdentTable.get("checked");
762     kw_decimal = &IdentTable.get("decimal");
763     kw_delegate = &IdentTable.get("delegate");
764     kw_event = &IdentTable.get("event");
765     kw_fixed = &IdentTable.get("fixed");
766     kw_foreach = &IdentTable.get("foreach");
767     kw_implicit = &IdentTable.get("implicit");
768     kw_internal = &IdentTable.get("internal");
769     kw_lock = &IdentTable.get("lock");
770     kw_null = &IdentTable.get("null");
771     kw_object = &IdentTable.get("object");
772     kw_out = &IdentTable.get("out");
773     kw_params = &IdentTable.get("params");
774     kw_ref = &IdentTable.get("ref");
775     kw_string = &IdentTable.get("string");
776     kw_stackalloc = &IdentTable.get("stackalloc");
777     kw_sbyte = &IdentTable.get("sbyte");
778     kw_sealed = &IdentTable.get("sealed");
779     kw_uint = &IdentTable.get("uint");
780     kw_ulong = &IdentTable.get("ulong");
781     kw_unchecked = &IdentTable.get("unchecked");
782     kw_unsafe = &IdentTable.get("unsafe");
783     kw_ushort = &IdentTable.get("ushort");
784     kw_when = &IdentTable.get("when");
785     kw_where = &IdentTable.get("where");
786 
787     // Keep this at the end of the constructor to make sure everything here
788     // is
789     // already initialized.
790     JsExtraKeywords = std::unordered_set<IdentifierInfo *>(
791         {kw_as, kw_async, kw_await, kw_declare, kw_finally, kw_from,
792          kw_function, kw_get, kw_import, kw_is, kw_let, kw_module, kw_readonly,
793          kw_set, kw_type, kw_typeof, kw_var, kw_yield,
794          // Keywords from the Java section.
795          kw_abstract, kw_extends, kw_implements, kw_instanceof, kw_interface});
796 
797     CSharpExtraKeywords = std::unordered_set<IdentifierInfo *>(
798         {kw_base, kw_byte, kw_checked, kw_decimal, kw_delegate, kw_event,
799          kw_fixed, kw_foreach, kw_implicit, kw_in, kw_interface, kw_internal,
800          kw_is, kw_lock, kw_null, kw_object, kw_out, kw_override, kw_params,
801          kw_readonly, kw_ref, kw_string, kw_stackalloc, kw_sbyte, kw_sealed,
802          kw_uint, kw_ulong, kw_unchecked, kw_unsafe, kw_ushort, kw_when,
803          kw_where,
804          // Keywords from the JavaScript section.
805          kw_as, kw_async, kw_await, kw_declare, kw_finally, kw_from,
806          kw_function, kw_get, kw_import, kw_is, kw_let, kw_module, kw_readonly,
807          kw_set, kw_type, kw_typeof, kw_var, kw_yield,
808          // Keywords from the Java section.
809          kw_abstract, kw_extends, kw_implements, kw_instanceof, kw_interface});
810   }
811 
812   // Context sensitive keywords.
813   IdentifierInfo *kw_final;
814   IdentifierInfo *kw_override;
815   IdentifierInfo *kw_in;
816   IdentifierInfo *kw_of;
817   IdentifierInfo *kw_CF_CLOSED_ENUM;
818   IdentifierInfo *kw_CF_ENUM;
819   IdentifierInfo *kw_CF_OPTIONS;
820   IdentifierInfo *kw_NS_CLOSED_ENUM;
821   IdentifierInfo *kw_NS_ENUM;
822   IdentifierInfo *kw_NS_OPTIONS;
823   IdentifierInfo *kw___except;
824   IdentifierInfo *kw___has_include;
825   IdentifierInfo *kw___has_include_next;
826 
827   // JavaScript keywords.
828   IdentifierInfo *kw_as;
829   IdentifierInfo *kw_async;
830   IdentifierInfo *kw_await;
831   IdentifierInfo *kw_declare;
832   IdentifierInfo *kw_finally;
833   IdentifierInfo *kw_from;
834   IdentifierInfo *kw_function;
835   IdentifierInfo *kw_get;
836   IdentifierInfo *kw_import;
837   IdentifierInfo *kw_infer;
838   IdentifierInfo *kw_is;
839   IdentifierInfo *kw_let;
840   IdentifierInfo *kw_module;
841   IdentifierInfo *kw_readonly;
842   IdentifierInfo *kw_set;
843   IdentifierInfo *kw_type;
844   IdentifierInfo *kw_typeof;
845   IdentifierInfo *kw_var;
846   IdentifierInfo *kw_yield;
847 
848   // Java keywords.
849   IdentifierInfo *kw_abstract;
850   IdentifierInfo *kw_assert;
851   IdentifierInfo *kw_extends;
852   IdentifierInfo *kw_implements;
853   IdentifierInfo *kw_instanceof;
854   IdentifierInfo *kw_interface;
855   IdentifierInfo *kw_native;
856   IdentifierInfo *kw_package;
857   IdentifierInfo *kw_synchronized;
858   IdentifierInfo *kw_throws;
859 
860   // Pragma keywords.
861   IdentifierInfo *kw_mark;
862 
863   // Proto keywords.
864   IdentifierInfo *kw_extend;
865   IdentifierInfo *kw_option;
866   IdentifierInfo *kw_optional;
867   IdentifierInfo *kw_repeated;
868   IdentifierInfo *kw_required;
869   IdentifierInfo *kw_returns;
870 
871   // QT keywords.
872   IdentifierInfo *kw_signals;
873   IdentifierInfo *kw_qsignals;
874   IdentifierInfo *kw_slots;
875   IdentifierInfo *kw_qslots;
876 
877   // C# keywords
878   IdentifierInfo *kw_dollar;
879   IdentifierInfo *kw_base;
880   IdentifierInfo *kw_byte;
881   IdentifierInfo *kw_checked;
882   IdentifierInfo *kw_decimal;
883   IdentifierInfo *kw_delegate;
884   IdentifierInfo *kw_event;
885   IdentifierInfo *kw_fixed;
886   IdentifierInfo *kw_foreach;
887   IdentifierInfo *kw_implicit;
888   IdentifierInfo *kw_internal;
889 
890   IdentifierInfo *kw_lock;
891   IdentifierInfo *kw_null;
892   IdentifierInfo *kw_object;
893   IdentifierInfo *kw_out;
894 
895   IdentifierInfo *kw_params;
896 
897   IdentifierInfo *kw_ref;
898   IdentifierInfo *kw_string;
899   IdentifierInfo *kw_stackalloc;
900   IdentifierInfo *kw_sbyte;
901   IdentifierInfo *kw_sealed;
902   IdentifierInfo *kw_uint;
903   IdentifierInfo *kw_ulong;
904   IdentifierInfo *kw_unchecked;
905   IdentifierInfo *kw_unsafe;
906   IdentifierInfo *kw_ushort;
907   IdentifierInfo *kw_when;
908   IdentifierInfo *kw_where;
909 
910   /// Returns \c true if \p Tok is a true JavaScript identifier, returns
911   /// \c false if it is a keyword or a pseudo keyword.
912   /// If \c AcceptIdentifierName is true, returns true not only for keywords,
913   // but also for IdentifierName tokens (aka pseudo-keywords), such as
914   // ``yield``.
915   bool IsJavaScriptIdentifier(const FormatToken &Tok,
916                               bool AcceptIdentifierName = true) const {
917     // Based on the list of JavaScript & TypeScript keywords here:
918     // https://github.com/microsoft/TypeScript/blob/master/src/compiler/scanner.ts#L74
919     switch (Tok.Tok.getKind()) {
920     case tok::kw_break:
921     case tok::kw_case:
922     case tok::kw_catch:
923     case tok::kw_class:
924     case tok::kw_continue:
925     case tok::kw_const:
926     case tok::kw_default:
927     case tok::kw_delete:
928     case tok::kw_do:
929     case tok::kw_else:
930     case tok::kw_enum:
931     case tok::kw_export:
932     case tok::kw_false:
933     case tok::kw_for:
934     case tok::kw_if:
935     case tok::kw_import:
936     case tok::kw_module:
937     case tok::kw_new:
938     case tok::kw_private:
939     case tok::kw_protected:
940     case tok::kw_public:
941     case tok::kw_return:
942     case tok::kw_static:
943     case tok::kw_switch:
944     case tok::kw_this:
945     case tok::kw_throw:
946     case tok::kw_true:
947     case tok::kw_try:
948     case tok::kw_typeof:
949     case tok::kw_void:
950     case tok::kw_while:
951       // These are JS keywords that are lexed by LLVM/clang as keywords.
952       return false;
953     case tok::identifier: {
954       // For identifiers, make sure they are true identifiers, excluding the
955       // JavaScript pseudo-keywords (not lexed by LLVM/clang as keywords).
956       bool IsPseudoKeyword =
957           JsExtraKeywords.find(Tok.Tok.getIdentifierInfo()) !=
958           JsExtraKeywords.end();
959       return AcceptIdentifierName || !IsPseudoKeyword;
960     }
961     default:
962       // Other keywords are handled in the switch below, to avoid problems due
963       // to duplicate case labels when using the #include trick.
964       break;
965     }
966 
967     switch (Tok.Tok.getKind()) {
968       // Handle C++ keywords not included above: these are all JS identifiers.
969 #define KEYWORD(X, Y) case tok::kw_##X:
970 #include "clang/Basic/TokenKinds.def"
971       // #undef KEYWORD is not needed -- it's #undef-ed at the end of
972       // TokenKinds.def
973       return true;
974     default:
975       // All other tokens (punctuation etc) are not JS identifiers.
976       return false;
977     }
978   }
979 
980   /// Returns \c true if \p Tok is a C# keyword, returns
981   /// \c false if it is a anything else.
982   bool isCSharpKeyword(const FormatToken &Tok) const {
983     switch (Tok.Tok.getKind()) {
984     case tok::kw_bool:
985     case tok::kw_break:
986     case tok::kw_case:
987     case tok::kw_catch:
988     case tok::kw_char:
989     case tok::kw_class:
990     case tok::kw_const:
991     case tok::kw_continue:
992     case tok::kw_default:
993     case tok::kw_do:
994     case tok::kw_double:
995     case tok::kw_else:
996     case tok::kw_enum:
997     case tok::kw_explicit:
998     case tok::kw_extern:
999     case tok::kw_false:
1000     case tok::kw_float:
1001     case tok::kw_for:
1002     case tok::kw_goto:
1003     case tok::kw_if:
1004     case tok::kw_int:
1005     case tok::kw_long:
1006     case tok::kw_namespace:
1007     case tok::kw_new:
1008     case tok::kw_operator:
1009     case tok::kw_private:
1010     case tok::kw_protected:
1011     case tok::kw_public:
1012     case tok::kw_return:
1013     case tok::kw_short:
1014     case tok::kw_sizeof:
1015     case tok::kw_static:
1016     case tok::kw_struct:
1017     case tok::kw_switch:
1018     case tok::kw_this:
1019     case tok::kw_throw:
1020     case tok::kw_true:
1021     case tok::kw_try:
1022     case tok::kw_typeof:
1023     case tok::kw_using:
1024     case tok::kw_virtual:
1025     case tok::kw_void:
1026     case tok::kw_volatile:
1027     case tok::kw_while:
1028       return true;
1029     default:
1030       return Tok.is(tok::identifier) &&
1031              CSharpExtraKeywords.find(Tok.Tok.getIdentifierInfo()) ==
1032                  CSharpExtraKeywords.end();
1033     }
1034   }
1035 
1036 private:
1037   /// The JavaScript keywords beyond the C++ keyword set.
1038   std::unordered_set<IdentifierInfo *> JsExtraKeywords;
1039 
1040   /// The C# keywords beyond the C++ keyword set
1041   std::unordered_set<IdentifierInfo *> CSharpExtraKeywords;
1042 };
1043 
1044 } // namespace format
1045 } // namespace clang
1046 
1047 #endif
1048