xref: /freebsd/contrib/llvm-project/clang/lib/Format/FormatToken.h (revision 77013d11e6483b970af25e13c9b892075742f7e5)
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(AttributeMacro)                                                         \
33   TYPE(AttributeParen)                                                         \
34   TYPE(AttributeSquare)                                                        \
35   TYPE(BinaryOperator)                                                         \
36   TYPE(BitFieldColon)                                                          \
37   TYPE(BlockComment)                                                           \
38   TYPE(CastRParen)                                                             \
39   TYPE(ConditionalExpr)                                                        \
40   TYPE(ConflictAlternative)                                                    \
41   TYPE(ConflictEnd)                                                            \
42   TYPE(ConflictStart)                                                          \
43   TYPE(ConstraintJunctions)                                                    \
44   TYPE(CtorInitializerColon)                                                   \
45   TYPE(CtorInitializerComma)                                                   \
46   TYPE(DesignatedInitializerLSquare)                                           \
47   TYPE(DesignatedInitializerPeriod)                                            \
48   TYPE(DictLiteral)                                                            \
49   TYPE(ForEachMacro)                                                           \
50   TYPE(FunctionAnnotationRParen)                                               \
51   TYPE(FunctionDeclarationName)                                                \
52   TYPE(FunctionLBrace)                                                         \
53   TYPE(FunctionTypeLParen)                                                     \
54   TYPE(ImplicitStringLiteral)                                                  \
55   TYPE(InheritanceColon)                                                       \
56   TYPE(InheritanceComma)                                                       \
57   TYPE(InlineASMBrace)                                                         \
58   TYPE(InlineASMColon)                                                         \
59   TYPE(InlineASMSymbolicNameLSquare)                                           \
60   TYPE(JavaAnnotation)                                                         \
61   TYPE(JsComputedPropertyName)                                                 \
62   TYPE(JsExponentiation)                                                       \
63   TYPE(JsExponentiationEqual)                                                  \
64   TYPE(JsFatArrow)                                                             \
65   TYPE(JsNonNullAssertion)                                                     \
66   TYPE(JsNullishCoalescingOperator)                                            \
67   TYPE(JsNullPropagatingOperator)                                              \
68   TYPE(JsPrivateIdentifier)                                                    \
69   TYPE(JsTypeColon)                                                            \
70   TYPE(JsTypeOperator)                                                         \
71   TYPE(JsTypeOptionalQuestion)                                                 \
72   TYPE(JsAndAndEqual)                                                          \
73   TYPE(JsPipePipeEqual)                                                        \
74   TYPE(JsNullishCoalescingEqual)                                               \
75   TYPE(LambdaArrow)                                                            \
76   TYPE(LambdaLBrace)                                                           \
77   TYPE(LambdaLSquare)                                                          \
78   TYPE(LeadingJavaAnnotation)                                                  \
79   TYPE(LineComment)                                                            \
80   TYPE(MacroBlockBegin)                                                        \
81   TYPE(MacroBlockEnd)                                                          \
82   TYPE(NamespaceMacro)                                                         \
83   TYPE(ObjCBlockLBrace)                                                        \
84   TYPE(ObjCBlockLParen)                                                        \
85   TYPE(ObjCDecl)                                                               \
86   TYPE(ObjCForIn)                                                              \
87   TYPE(ObjCMethodExpr)                                                         \
88   TYPE(ObjCMethodSpecifier)                                                    \
89   TYPE(ObjCProperty)                                                           \
90   TYPE(ObjCStringLiteral)                                                      \
91   TYPE(OverloadedOperator)                                                     \
92   TYPE(OverloadedOperatorLParen)                                               \
93   TYPE(PointerOrReference)                                                     \
94   TYPE(PureVirtualSpecifier)                                                   \
95   TYPE(RangeBasedForLoopColon)                                                 \
96   TYPE(RegexLiteral)                                                           \
97   TYPE(SelectorName)                                                           \
98   TYPE(StartOfName)                                                            \
99   TYPE(StatementAttributeLikeMacro)                                            \
100   TYPE(StatementMacro)                                                         \
101   TYPE(StructuredBindingLSquare)                                               \
102   TYPE(TemplateCloser)                                                         \
103   TYPE(TemplateOpener)                                                         \
104   TYPE(TemplateString)                                                         \
105   TYPE(ProtoExtensionLSquare)                                                  \
106   TYPE(TrailingAnnotation)                                                     \
107   TYPE(TrailingReturnArrow)                                                    \
108   TYPE(TrailingUnaryOperator)                                                  \
109   TYPE(TypeDeclarationParen)                                                   \
110   TYPE(TypenameMacro)                                                          \
111   TYPE(UnaryOperator)                                                          \
112   TYPE(UntouchableMacroFunc)                                                   \
113   TYPE(CSharpStringLiteral)                                                    \
114   TYPE(CSharpNamedArgumentColon)                                               \
115   TYPE(CSharpNullable)                                                         \
116   TYPE(CSharpNullCoalescing)                                                   \
117   TYPE(CSharpNullConditional)                                                  \
118   TYPE(CSharpNullConditionalLSquare)                                           \
119   TYPE(CSharpGenericTypeConstraint)                                            \
120   TYPE(CSharpGenericTypeConstraintColon)                                       \
121   TYPE(CSharpGenericTypeConstraintComma)                                       \
122   TYPE(Unknown)
123 
124 /// Determines the semantic type of a syntactic token, e.g. whether "<" is a
125 /// template opener or binary operator.
126 enum TokenType : uint8_t {
127 #define TYPE(X) TT_##X,
128   LIST_TOKEN_TYPES
129 #undef TYPE
130       NUM_TOKEN_TYPES
131 };
132 
133 /// Determines the name of a token type.
134 const char *getTokenTypeName(TokenType Type);
135 
136 // Represents what type of block a set of braces open.
137 enum BraceBlockKind { BK_Unknown, BK_Block, BK_BracedInit };
138 
139 // The packing kind of a function's parameters.
140 enum ParameterPackingKind { PPK_BinPacked, PPK_OnePerLine, PPK_Inconclusive };
141 
142 enum FormatDecision { FD_Unformatted, FD_Continue, FD_Break };
143 
144 /// Roles a token can take in a configured macro expansion.
145 enum MacroRole {
146   /// The token was expanded from a macro argument when formatting the expanded
147   /// token sequence.
148   MR_ExpandedArg,
149   /// The token is part of a macro argument that was previously formatted as
150   /// expansion when formatting the unexpanded macro call.
151   MR_UnexpandedArg,
152   /// The token was expanded from a macro definition, and is not visible as part
153   /// of the macro call.
154   MR_Hidden,
155 };
156 
157 struct FormatToken;
158 
159 /// Contains information on the token's role in a macro expansion.
160 ///
161 /// Given the following definitions:
162 /// A(X) = [ X ]
163 /// B(X) = < X >
164 /// C(X) = X
165 ///
166 /// Consider the macro call:
167 /// A({B(C(C(x)))}) -> [{<x>}]
168 ///
169 /// In this case, the tokens of the unexpanded macro call will have the
170 /// following relevant entries in their macro context (note that formatting
171 /// the unexpanded macro call happens *after* formatting the expanded macro
172 /// call):
173 ///                   A( { B( C( C(x) ) ) } )
174 /// Role:             NN U NN NN NNUN N N U N  (N=None, U=UnexpandedArg)
175 ///
176 ///                   [  { <       x    > } ]
177 /// Role:             H  E H       E    H E H  (H=Hidden, E=ExpandedArg)
178 /// ExpandedFrom[0]:  A  A A       A    A A A
179 /// ExpandedFrom[1]:       B       B    B
180 /// ExpandedFrom[2]:               C
181 /// ExpandedFrom[3]:               C
182 /// StartOfExpansion: 1  0 1       2    0 0 0
183 /// EndOfExpansion:   0  0 0       2    1 0 1
184 struct MacroExpansion {
185   MacroExpansion(MacroRole Role) : Role(Role) {}
186 
187   /// The token's role in the macro expansion.
188   /// When formatting an expanded macro, all tokens that are part of macro
189   /// arguments will be MR_ExpandedArg, while all tokens that are not visible in
190   /// the macro call will be MR_Hidden.
191   /// When formatting an unexpanded macro call, all tokens that are part of
192   /// macro arguments will be MR_UnexpandedArg.
193   MacroRole Role;
194 
195   /// The stack of macro call identifier tokens this token was expanded from.
196   llvm::SmallVector<FormatToken *, 1> ExpandedFrom;
197 
198   /// The number of expansions of which this macro is the first entry.
199   unsigned StartOfExpansion = 0;
200 
201   /// The number of currently open expansions in \c ExpandedFrom this macro is
202   /// the last token in.
203   unsigned EndOfExpansion = 0;
204 };
205 
206 class TokenRole;
207 class AnnotatedLine;
208 
209 /// A wrapper around a \c Token storing information about the
210 /// whitespace characters preceding it.
211 struct FormatToken {
212   FormatToken()
213       : HasUnescapedNewline(false), IsMultiline(false), IsFirst(false),
214         MustBreakBefore(false), IsUnterminatedLiteral(false),
215         CanBreakBefore(false), ClosesTemplateDeclaration(false),
216         StartsBinaryExpression(false), EndsBinaryExpression(false),
217         PartOfMultiVariableDeclStmt(false), ContinuesLineCommentSection(false),
218         Finalized(false), BlockKind(BK_Unknown), Decision(FD_Unformatted),
219         PackingKind(PPK_Inconclusive), Type(TT_Unknown) {}
220 
221   /// The \c Token.
222   Token Tok;
223 
224   /// The raw text of the token.
225   ///
226   /// Contains the raw token text without leading whitespace and without leading
227   /// escaped newlines.
228   StringRef TokenText;
229 
230   /// A token can have a special role that can carry extra information
231   /// about the token's formatting.
232   /// FIXME: Make FormatToken for parsing and AnnotatedToken two different
233   /// classes and make this a unique_ptr in the AnnotatedToken class.
234   std::shared_ptr<TokenRole> Role;
235 
236   /// The range of the whitespace immediately preceding the \c Token.
237   SourceRange WhitespaceRange;
238 
239   /// Whether there is at least one unescaped newline before the \c
240   /// Token.
241   unsigned HasUnescapedNewline : 1;
242 
243   /// Whether the token text contains newlines (escaped or not).
244   unsigned IsMultiline : 1;
245 
246   /// Indicates that this is the first token of the file.
247   unsigned IsFirst : 1;
248 
249   /// Whether there must be a line break before this token.
250   ///
251   /// This happens for example when a preprocessor directive ended directly
252   /// before the token.
253   unsigned MustBreakBefore : 1;
254 
255   /// Set to \c true if this token is an unterminated literal.
256   unsigned IsUnterminatedLiteral : 1;
257 
258   /// \c true if it is allowed to break before this token.
259   unsigned CanBreakBefore : 1;
260 
261   /// \c true if this is the ">" of "template<..>".
262   unsigned ClosesTemplateDeclaration : 1;
263 
264   /// \c true if this token starts a binary expression, i.e. has at least
265   /// one fake l_paren with a precedence greater than prec::Unknown.
266   unsigned StartsBinaryExpression : 1;
267   /// \c true if this token ends a binary expression.
268   unsigned EndsBinaryExpression : 1;
269 
270   /// Is this token part of a \c DeclStmt defining multiple variables?
271   ///
272   /// Only set if \c Type == \c TT_StartOfName.
273   unsigned PartOfMultiVariableDeclStmt : 1;
274 
275   /// Does this line comment continue a line comment section?
276   ///
277   /// Only set to true if \c Type == \c TT_LineComment.
278   unsigned ContinuesLineCommentSection : 1;
279 
280   /// If \c true, this token has been fully formatted (indented and
281   /// potentially re-formatted inside), and we do not allow further formatting
282   /// changes.
283   unsigned Finalized : 1;
284 
285 private:
286   /// Contains the kind of block if this token is a brace.
287   unsigned BlockKind : 2;
288 
289 public:
290   BraceBlockKind getBlockKind() const {
291     return static_cast<BraceBlockKind>(BlockKind);
292   }
293   void setBlockKind(BraceBlockKind BBK) {
294     BlockKind = BBK;
295     assert(getBlockKind() == BBK && "BraceBlockKind overflow!");
296   }
297 
298 private:
299   /// Stores the formatting decision for the token once it was made.
300   unsigned Decision : 2;
301 
302 public:
303   FormatDecision getDecision() const {
304     return static_cast<FormatDecision>(Decision);
305   }
306   void setDecision(FormatDecision D) {
307     Decision = D;
308     assert(getDecision() == D && "FormatDecision overflow!");
309   }
310 
311 private:
312   /// If this is an opening parenthesis, how are the parameters packed?
313   unsigned PackingKind : 2;
314 
315 public:
316   ParameterPackingKind getPackingKind() const {
317     return static_cast<ParameterPackingKind>(PackingKind);
318   }
319   void setPackingKind(ParameterPackingKind K) {
320     PackingKind = K;
321     assert(getPackingKind() == K && "ParameterPackingKind overflow!");
322   }
323 
324 private:
325   TokenType Type;
326 
327 public:
328   /// Returns the token's type, e.g. whether "<" is a template opener or
329   /// binary operator.
330   TokenType getType() const { return Type; }
331   void setType(TokenType T) { Type = T; }
332 
333   /// The number of newlines immediately before the \c Token.
334   ///
335   /// This can be used to determine what the user wrote in the original code
336   /// and thereby e.g. leave an empty line between two function definitions.
337   unsigned NewlinesBefore = 0;
338 
339   /// The offset just past the last '\n' in this token's leading
340   /// whitespace (relative to \c WhiteSpaceStart). 0 if there is no '\n'.
341   unsigned LastNewlineOffset = 0;
342 
343   /// The width of the non-whitespace parts of the token (or its first
344   /// line for multi-line tokens) in columns.
345   /// We need this to correctly measure number of columns a token spans.
346   unsigned ColumnWidth = 0;
347 
348   /// Contains the width in columns of the last line of a multi-line
349   /// token.
350   unsigned LastLineColumnWidth = 0;
351 
352   /// The number of spaces that should be inserted before this token.
353   unsigned SpacesRequiredBefore = 0;
354 
355   /// Number of parameters, if this is "(", "[" or "<".
356   unsigned ParameterCount = 0;
357 
358   /// Number of parameters that are nested blocks,
359   /// if this is "(", "[" or "<".
360   unsigned BlockParameterCount = 0;
361 
362   /// If this is a bracket ("<", "(", "[" or "{"), contains the kind of
363   /// the surrounding bracket.
364   tok::TokenKind ParentBracket = tok::unknown;
365 
366   /// The total length of the unwrapped line up to and including this
367   /// token.
368   unsigned TotalLength = 0;
369 
370   /// The original 0-based column of this token, including expanded tabs.
371   /// The configured TabWidth is used as tab width.
372   unsigned OriginalColumn = 0;
373 
374   /// The length of following tokens until the next natural split point,
375   /// or the next token that can be broken.
376   unsigned UnbreakableTailLength = 0;
377 
378   // FIXME: Come up with a 'cleaner' concept.
379   /// The binding strength of a token. This is a combined value of
380   /// operator precedence, parenthesis nesting, etc.
381   unsigned BindingStrength = 0;
382 
383   /// The nesting level of this token, i.e. the number of surrounding (),
384   /// [], {} or <>.
385   unsigned NestingLevel = 0;
386 
387   /// The indent level of this token. Copied from the surrounding line.
388   unsigned IndentLevel = 0;
389 
390   /// Penalty for inserting a line break before this token.
391   unsigned SplitPenalty = 0;
392 
393   /// If this is the first ObjC selector name in an ObjC method
394   /// definition or call, this contains the length of the longest name.
395   ///
396   /// This being set to 0 means that the selectors should not be colon-aligned,
397   /// e.g. because several of them are block-type.
398   unsigned LongestObjCSelectorName = 0;
399 
400   /// If this is the first ObjC selector name in an ObjC method
401   /// definition or call, this contains the number of parts that the whole
402   /// selector consist of.
403   unsigned ObjCSelectorNameParts = 0;
404 
405   /// The 0-based index of the parameter/argument. For ObjC it is set
406   /// for the selector name token.
407   /// For now calculated only for ObjC.
408   unsigned ParameterIndex = 0;
409 
410   /// Stores the number of required fake parentheses and the
411   /// corresponding operator precedence.
412   ///
413   /// If multiple fake parentheses start at a token, this vector stores them in
414   /// reverse order, i.e. inner fake parenthesis first.
415   SmallVector<prec::Level, 4> FakeLParens;
416   /// Insert this many fake ) after this token for correct indentation.
417   unsigned FakeRParens = 0;
418 
419   /// If this is an operator (or "."/"->") in a sequence of operators
420   /// with the same precedence, contains the 0-based operator index.
421   unsigned OperatorIndex = 0;
422 
423   /// If this is an operator (or "."/"->") in a sequence of operators
424   /// with the same precedence, points to the next operator.
425   FormatToken *NextOperator = nullptr;
426 
427   /// If this is a bracket, this points to the matching one.
428   FormatToken *MatchingParen = nullptr;
429 
430   /// The previous token in the unwrapped line.
431   FormatToken *Previous = nullptr;
432 
433   /// The next token in the unwrapped line.
434   FormatToken *Next = nullptr;
435 
436   /// If this token starts a block, this contains all the unwrapped lines
437   /// in it.
438   SmallVector<AnnotatedLine *, 1> Children;
439 
440   // Contains all attributes related to how this token takes part
441   // in a configured macro expansion.
442   llvm::Optional<MacroExpansion> MacroCtx;
443 
444   bool is(tok::TokenKind Kind) const { return Tok.is(Kind); }
445   bool is(TokenType TT) const { return getType() == TT; }
446   bool is(const IdentifierInfo *II) const {
447     return II && II == Tok.getIdentifierInfo();
448   }
449   bool is(tok::PPKeywordKind Kind) const {
450     return Tok.getIdentifierInfo() &&
451            Tok.getIdentifierInfo()->getPPKeywordID() == Kind;
452   }
453   bool is(BraceBlockKind BBK) const { return getBlockKind() == BBK; }
454   bool is(ParameterPackingKind PPK) const { return getPackingKind() == PPK; }
455 
456   template <typename A, typename B> bool isOneOf(A K1, B K2) const {
457     return is(K1) || is(K2);
458   }
459   template <typename A, typename B, typename... Ts>
460   bool isOneOf(A K1, B K2, Ts... Ks) const {
461     return is(K1) || isOneOf(K2, Ks...);
462   }
463   template <typename T> bool isNot(T Kind) const { return !is(Kind); }
464 
465   bool isIf(bool AllowConstexprMacro = true) const {
466     return is(tok::kw_if) || endsSequence(tok::kw_constexpr, tok::kw_if) ||
467            (endsSequence(tok::identifier, tok::kw_if) && AllowConstexprMacro);
468   }
469 
470   bool closesScopeAfterBlock() const {
471     if (getBlockKind() == BK_Block)
472       return true;
473     if (closesScope())
474       return Previous->closesScopeAfterBlock();
475     return false;
476   }
477 
478   /// \c true if this token starts a sequence with the given tokens in order,
479   /// following the ``Next`` pointers, ignoring comments.
480   template <typename A, typename... Ts>
481   bool startsSequence(A K1, Ts... Tokens) const {
482     return startsSequenceInternal(K1, Tokens...);
483   }
484 
485   /// \c true if this token ends a sequence with the given tokens in order,
486   /// following the ``Previous`` pointers, ignoring comments.
487   /// For example, given tokens [T1, T2, T3], the function returns true if
488   /// 3 tokens ending at this (ignoring comments) are [T3, T2, T1]. In other
489   /// words, the tokens passed to this function need to the reverse of the
490   /// order the tokens appear in code.
491   template <typename A, typename... Ts>
492   bool endsSequence(A K1, Ts... Tokens) const {
493     return endsSequenceInternal(K1, Tokens...);
494   }
495 
496   bool isStringLiteral() const { return tok::isStringLiteral(Tok.getKind()); }
497 
498   bool isObjCAtKeyword(tok::ObjCKeywordKind Kind) const {
499     return Tok.isObjCAtKeyword(Kind);
500   }
501 
502   bool isAccessSpecifier(bool ColonRequired = true) const {
503     return isOneOf(tok::kw_public, tok::kw_protected, tok::kw_private) &&
504            (!ColonRequired || (Next && Next->is(tok::colon)));
505   }
506 
507   bool canBePointerOrReferenceQualifier() const {
508     return isOneOf(tok::kw_const, tok::kw_restrict, tok::kw_volatile,
509                    tok::kw___attribute, tok::kw__Nonnull, tok::kw__Nullable,
510                    tok::kw__Null_unspecified, tok::kw___ptr32, tok::kw___ptr64,
511                    TT_AttributeMacro);
512   }
513 
514   /// Determine whether the token is a simple-type-specifier.
515   bool isSimpleTypeSpecifier() const;
516 
517   bool isObjCAccessSpecifier() const {
518     return is(tok::at) && Next &&
519            (Next->isObjCAtKeyword(tok::objc_public) ||
520             Next->isObjCAtKeyword(tok::objc_protected) ||
521             Next->isObjCAtKeyword(tok::objc_package) ||
522             Next->isObjCAtKeyword(tok::objc_private));
523   }
524 
525   /// Returns whether \p Tok is ([{ or an opening < of a template or in
526   /// protos.
527   bool opensScope() const {
528     if (is(TT_TemplateString) && TokenText.endswith("${"))
529       return true;
530     if (is(TT_DictLiteral) && is(tok::less))
531       return true;
532     return isOneOf(tok::l_paren, tok::l_brace, tok::l_square,
533                    TT_TemplateOpener);
534   }
535   /// Returns whether \p Tok is )]} or a closing > of a template or in
536   /// protos.
537   bool closesScope() const {
538     if (is(TT_TemplateString) && TokenText.startswith("}"))
539       return true;
540     if (is(TT_DictLiteral) && is(tok::greater))
541       return true;
542     return isOneOf(tok::r_paren, tok::r_brace, tok::r_square,
543                    TT_TemplateCloser);
544   }
545 
546   /// Returns \c true if this is a "." or "->" accessing a member.
547   bool isMemberAccess() const {
548     return isOneOf(tok::arrow, tok::period, tok::arrowstar) &&
549            !isOneOf(TT_DesignatedInitializerPeriod, TT_TrailingReturnArrow,
550                     TT_LambdaArrow, TT_LeadingJavaAnnotation);
551   }
552 
553   bool isUnaryOperator() const {
554     switch (Tok.getKind()) {
555     case tok::plus:
556     case tok::plusplus:
557     case tok::minus:
558     case tok::minusminus:
559     case tok::exclaim:
560     case tok::tilde:
561     case tok::kw_sizeof:
562     case tok::kw_alignof:
563       return true;
564     default:
565       return false;
566     }
567   }
568 
569   bool isBinaryOperator() const {
570     // Comma is a binary operator, but does not behave as such wrt. formatting.
571     return getPrecedence() > prec::Comma;
572   }
573 
574   bool isTrailingComment() const {
575     return is(tok::comment) &&
576            (is(TT_LineComment) || !Next || Next->NewlinesBefore > 0);
577   }
578 
579   /// Returns \c true if this is a keyword that can be used
580   /// like a function call (e.g. sizeof, typeid, ...).
581   bool isFunctionLikeKeyword() const {
582     switch (Tok.getKind()) {
583     case tok::kw_throw:
584     case tok::kw_typeid:
585     case tok::kw_return:
586     case tok::kw_sizeof:
587     case tok::kw_alignof:
588     case tok::kw_alignas:
589     case tok::kw_decltype:
590     case tok::kw_noexcept:
591     case tok::kw_static_assert:
592     case tok::kw__Atomic:
593     case tok::kw___attribute:
594     case tok::kw___underlying_type:
595     case tok::kw_requires:
596       return true;
597     default:
598       return false;
599     }
600   }
601 
602   /// Returns \c true if this is a string literal that's like a label,
603   /// e.g. ends with "=" or ":".
604   bool isLabelString() const {
605     if (!is(tok::string_literal))
606       return false;
607     StringRef Content = TokenText;
608     if (Content.startswith("\"") || Content.startswith("'"))
609       Content = Content.drop_front(1);
610     if (Content.endswith("\"") || Content.endswith("'"))
611       Content = Content.drop_back(1);
612     Content = Content.trim();
613     return Content.size() > 1 &&
614            (Content.back() == ':' || Content.back() == '=');
615   }
616 
617   /// Returns actual token start location without leading escaped
618   /// newlines and whitespace.
619   ///
620   /// This can be different to Tok.getLocation(), which includes leading escaped
621   /// newlines.
622   SourceLocation getStartOfNonWhitespace() const {
623     return WhitespaceRange.getEnd();
624   }
625 
626   prec::Level getPrecedence() const {
627     return getBinOpPrecedence(Tok.getKind(), /*GreaterThanIsOperator=*/true,
628                               /*CPlusPlus11=*/true);
629   }
630 
631   /// Returns the previous token ignoring comments.
632   FormatToken *getPreviousNonComment() const {
633     FormatToken *Tok = Previous;
634     while (Tok && Tok->is(tok::comment))
635       Tok = Tok->Previous;
636     return Tok;
637   }
638 
639   /// Returns the next token ignoring comments.
640   const FormatToken *getNextNonComment() const {
641     const FormatToken *Tok = Next;
642     while (Tok && Tok->is(tok::comment))
643       Tok = Tok->Next;
644     return Tok;
645   }
646 
647   /// Returns \c true if this tokens starts a block-type list, i.e. a
648   /// list that should be indented with a block indent.
649   bool opensBlockOrBlockTypeList(const FormatStyle &Style) const {
650     // C# Does not indent object initialisers as continuations.
651     if (is(tok::l_brace) && getBlockKind() == BK_BracedInit && Style.isCSharp())
652       return true;
653     if (is(TT_TemplateString) && opensScope())
654       return true;
655     return is(TT_ArrayInitializerLSquare) || is(TT_ProtoExtensionLSquare) ||
656            (is(tok::l_brace) &&
657             (getBlockKind() == BK_Block || is(TT_DictLiteral) ||
658              (!Style.Cpp11BracedListStyle && NestingLevel == 0))) ||
659            (is(tok::less) && (Style.Language == FormatStyle::LK_Proto ||
660                               Style.Language == FormatStyle::LK_TextProto));
661   }
662 
663   /// Returns whether the token is the left square bracket of a C++
664   /// structured binding declaration.
665   bool isCppStructuredBinding(const FormatStyle &Style) const {
666     if (!Style.isCpp() || isNot(tok::l_square))
667       return false;
668     const FormatToken *T = this;
669     do {
670       T = T->getPreviousNonComment();
671     } while (T && T->isOneOf(tok::kw_const, tok::kw_volatile, tok::amp,
672                              tok::ampamp));
673     return T && T->is(tok::kw_auto);
674   }
675 
676   /// Same as opensBlockOrBlockTypeList, but for the closing token.
677   bool closesBlockOrBlockTypeList(const FormatStyle &Style) const {
678     if (is(TT_TemplateString) && closesScope())
679       return true;
680     return MatchingParen && MatchingParen->opensBlockOrBlockTypeList(Style);
681   }
682 
683   /// Return the actual namespace token, if this token starts a namespace
684   /// block.
685   const FormatToken *getNamespaceToken() const {
686     const FormatToken *NamespaceTok = this;
687     if (is(tok::comment))
688       NamespaceTok = NamespaceTok->getNextNonComment();
689     // Detect "(inline|export)? namespace" in the beginning of a line.
690     if (NamespaceTok && NamespaceTok->isOneOf(tok::kw_inline, tok::kw_export))
691       NamespaceTok = NamespaceTok->getNextNonComment();
692     return NamespaceTok &&
693                    NamespaceTok->isOneOf(tok::kw_namespace, TT_NamespaceMacro)
694                ? NamespaceTok
695                : nullptr;
696   }
697 
698   void copyFrom(const FormatToken &Tok) { *this = Tok; }
699 
700 private:
701   // Only allow copying via the explicit copyFrom method.
702   FormatToken(const FormatToken &) = delete;
703   FormatToken &operator=(const FormatToken &) = default;
704 
705   template <typename A, typename... Ts>
706   bool startsSequenceInternal(A K1, Ts... Tokens) const {
707     if (is(tok::comment) && Next)
708       return Next->startsSequenceInternal(K1, Tokens...);
709     return is(K1) && Next && Next->startsSequenceInternal(Tokens...);
710   }
711 
712   template <typename A> bool startsSequenceInternal(A K1) const {
713     if (is(tok::comment) && Next)
714       return Next->startsSequenceInternal(K1);
715     return is(K1);
716   }
717 
718   template <typename A, typename... Ts> bool endsSequenceInternal(A K1) const {
719     if (is(tok::comment) && Previous)
720       return Previous->endsSequenceInternal(K1);
721     return is(K1);
722   }
723 
724   template <typename A, typename... Ts>
725   bool endsSequenceInternal(A K1, Ts... Tokens) const {
726     if (is(tok::comment) && Previous)
727       return Previous->endsSequenceInternal(K1, Tokens...);
728     return is(K1) && Previous && Previous->endsSequenceInternal(Tokens...);
729   }
730 };
731 
732 class ContinuationIndenter;
733 struct LineState;
734 
735 class TokenRole {
736 public:
737   TokenRole(const FormatStyle &Style) : Style(Style) {}
738   virtual ~TokenRole();
739 
740   /// After the \c TokenAnnotator has finished annotating all the tokens,
741   /// this function precomputes required information for formatting.
742   virtual void precomputeFormattingInfos(const FormatToken *Token);
743 
744   /// Apply the special formatting that the given role demands.
745   ///
746   /// Assumes that the token having this role is already formatted.
747   ///
748   /// Continues formatting from \p State leaving indentation to \p Indenter and
749   /// returns the total penalty that this formatting incurs.
750   virtual unsigned formatFromToken(LineState &State,
751                                    ContinuationIndenter *Indenter,
752                                    bool DryRun) {
753     return 0;
754   }
755 
756   /// Same as \c formatFromToken, but assumes that the first token has
757   /// already been set thereby deciding on the first line break.
758   virtual unsigned formatAfterToken(LineState &State,
759                                     ContinuationIndenter *Indenter,
760                                     bool DryRun) {
761     return 0;
762   }
763 
764   /// Notifies the \c Role that a comma was found.
765   virtual void CommaFound(const FormatToken *Token) {}
766 
767   virtual const FormatToken *lastComma() { return nullptr; }
768 
769 protected:
770   const FormatStyle &Style;
771 };
772 
773 class CommaSeparatedList : public TokenRole {
774 public:
775   CommaSeparatedList(const FormatStyle &Style)
776       : TokenRole(Style), HasNestedBracedList(false) {}
777 
778   void precomputeFormattingInfos(const FormatToken *Token) override;
779 
780   unsigned formatAfterToken(LineState &State, ContinuationIndenter *Indenter,
781                             bool DryRun) override;
782 
783   unsigned formatFromToken(LineState &State, ContinuationIndenter *Indenter,
784                            bool DryRun) override;
785 
786   /// Adds \p Token as the next comma to the \c CommaSeparated list.
787   void CommaFound(const FormatToken *Token) override {
788     Commas.push_back(Token);
789   }
790 
791   const FormatToken *lastComma() override {
792     if (Commas.empty())
793       return nullptr;
794     return Commas.back();
795   }
796 
797 private:
798   /// A struct that holds information on how to format a given list with
799   /// a specific number of columns.
800   struct ColumnFormat {
801     /// The number of columns to use.
802     unsigned Columns;
803 
804     /// The total width in characters.
805     unsigned TotalWidth;
806 
807     /// The number of lines required for this format.
808     unsigned LineCount;
809 
810     /// The size of each column in characters.
811     SmallVector<unsigned, 8> ColumnSizes;
812   };
813 
814   /// Calculate which \c ColumnFormat fits best into
815   /// \p RemainingCharacters.
816   const ColumnFormat *getColumnFormat(unsigned RemainingCharacters) const;
817 
818   /// The ordered \c FormatTokens making up the commas of this list.
819   SmallVector<const FormatToken *, 8> Commas;
820 
821   /// The length of each of the list's items in characters including the
822   /// trailing comma.
823   SmallVector<unsigned, 8> ItemLengths;
824 
825   /// Precomputed formats that can be used for this list.
826   SmallVector<ColumnFormat, 4> Formats;
827 
828   bool HasNestedBracedList;
829 };
830 
831 /// Encapsulates keywords that are context sensitive or for languages not
832 /// properly supported by Clang's lexer.
833 struct AdditionalKeywords {
834   AdditionalKeywords(IdentifierTable &IdentTable) {
835     kw_final = &IdentTable.get("final");
836     kw_override = &IdentTable.get("override");
837     kw_in = &IdentTable.get("in");
838     kw_of = &IdentTable.get("of");
839     kw_CF_CLOSED_ENUM = &IdentTable.get("CF_CLOSED_ENUM");
840     kw_CF_ENUM = &IdentTable.get("CF_ENUM");
841     kw_CF_OPTIONS = &IdentTable.get("CF_OPTIONS");
842     kw_NS_CLOSED_ENUM = &IdentTable.get("NS_CLOSED_ENUM");
843     kw_NS_ENUM = &IdentTable.get("NS_ENUM");
844     kw_NS_OPTIONS = &IdentTable.get("NS_OPTIONS");
845 
846     kw_as = &IdentTable.get("as");
847     kw_async = &IdentTable.get("async");
848     kw_await = &IdentTable.get("await");
849     kw_declare = &IdentTable.get("declare");
850     kw_finally = &IdentTable.get("finally");
851     kw_from = &IdentTable.get("from");
852     kw_function = &IdentTable.get("function");
853     kw_get = &IdentTable.get("get");
854     kw_import = &IdentTable.get("import");
855     kw_infer = &IdentTable.get("infer");
856     kw_is = &IdentTable.get("is");
857     kw_let = &IdentTable.get("let");
858     kw_module = &IdentTable.get("module");
859     kw_readonly = &IdentTable.get("readonly");
860     kw_set = &IdentTable.get("set");
861     kw_type = &IdentTable.get("type");
862     kw_typeof = &IdentTable.get("typeof");
863     kw_var = &IdentTable.get("var");
864     kw_yield = &IdentTable.get("yield");
865 
866     kw_abstract = &IdentTable.get("abstract");
867     kw_assert = &IdentTable.get("assert");
868     kw_extends = &IdentTable.get("extends");
869     kw_implements = &IdentTable.get("implements");
870     kw_instanceof = &IdentTable.get("instanceof");
871     kw_interface = &IdentTable.get("interface");
872     kw_native = &IdentTable.get("native");
873     kw_package = &IdentTable.get("package");
874     kw_synchronized = &IdentTable.get("synchronized");
875     kw_throws = &IdentTable.get("throws");
876     kw___except = &IdentTable.get("__except");
877     kw___has_include = &IdentTable.get("__has_include");
878     kw___has_include_next = &IdentTable.get("__has_include_next");
879 
880     kw_mark = &IdentTable.get("mark");
881 
882     kw_extend = &IdentTable.get("extend");
883     kw_option = &IdentTable.get("option");
884     kw_optional = &IdentTable.get("optional");
885     kw_repeated = &IdentTable.get("repeated");
886     kw_required = &IdentTable.get("required");
887     kw_returns = &IdentTable.get("returns");
888 
889     kw_signals = &IdentTable.get("signals");
890     kw_qsignals = &IdentTable.get("Q_SIGNALS");
891     kw_slots = &IdentTable.get("slots");
892     kw_qslots = &IdentTable.get("Q_SLOTS");
893 
894     // C# keywords
895     kw_dollar = &IdentTable.get("dollar");
896     kw_base = &IdentTable.get("base");
897     kw_byte = &IdentTable.get("byte");
898     kw_checked = &IdentTable.get("checked");
899     kw_decimal = &IdentTable.get("decimal");
900     kw_delegate = &IdentTable.get("delegate");
901     kw_event = &IdentTable.get("event");
902     kw_fixed = &IdentTable.get("fixed");
903     kw_foreach = &IdentTable.get("foreach");
904     kw_implicit = &IdentTable.get("implicit");
905     kw_internal = &IdentTable.get("internal");
906     kw_lock = &IdentTable.get("lock");
907     kw_null = &IdentTable.get("null");
908     kw_object = &IdentTable.get("object");
909     kw_out = &IdentTable.get("out");
910     kw_params = &IdentTable.get("params");
911     kw_ref = &IdentTable.get("ref");
912     kw_string = &IdentTable.get("string");
913     kw_stackalloc = &IdentTable.get("stackalloc");
914     kw_sbyte = &IdentTable.get("sbyte");
915     kw_sealed = &IdentTable.get("sealed");
916     kw_uint = &IdentTable.get("uint");
917     kw_ulong = &IdentTable.get("ulong");
918     kw_unchecked = &IdentTable.get("unchecked");
919     kw_unsafe = &IdentTable.get("unsafe");
920     kw_ushort = &IdentTable.get("ushort");
921     kw_when = &IdentTable.get("when");
922     kw_where = &IdentTable.get("where");
923 
924     // Keep this at the end of the constructor to make sure everything here
925     // is
926     // already initialized.
927     JsExtraKeywords = std::unordered_set<IdentifierInfo *>(
928         {kw_as, kw_async, kw_await, kw_declare, kw_finally, kw_from,
929          kw_function, kw_get, kw_import, kw_is, kw_let, kw_module, kw_readonly,
930          kw_set, kw_type, kw_typeof, kw_var, kw_yield,
931          // Keywords from the Java section.
932          kw_abstract, kw_extends, kw_implements, kw_instanceof, kw_interface});
933 
934     CSharpExtraKeywords = std::unordered_set<IdentifierInfo *>(
935         {kw_base, kw_byte, kw_checked, kw_decimal, kw_delegate, kw_event,
936          kw_fixed, kw_foreach, kw_implicit, kw_in, kw_interface, kw_internal,
937          kw_is, kw_lock, kw_null, kw_object, kw_out, kw_override, kw_params,
938          kw_readonly, kw_ref, kw_string, kw_stackalloc, kw_sbyte, kw_sealed,
939          kw_uint, kw_ulong, kw_unchecked, kw_unsafe, kw_ushort, kw_when,
940          kw_where,
941          // Keywords from the JavaScript section.
942          kw_as, kw_async, kw_await, kw_declare, kw_finally, kw_from,
943          kw_function, kw_get, kw_import, kw_is, kw_let, kw_module, kw_readonly,
944          kw_set, kw_type, kw_typeof, kw_var, kw_yield,
945          // Keywords from the Java section.
946          kw_abstract, kw_extends, kw_implements, kw_instanceof, kw_interface});
947   }
948 
949   // Context sensitive keywords.
950   IdentifierInfo *kw_final;
951   IdentifierInfo *kw_override;
952   IdentifierInfo *kw_in;
953   IdentifierInfo *kw_of;
954   IdentifierInfo *kw_CF_CLOSED_ENUM;
955   IdentifierInfo *kw_CF_ENUM;
956   IdentifierInfo *kw_CF_OPTIONS;
957   IdentifierInfo *kw_NS_CLOSED_ENUM;
958   IdentifierInfo *kw_NS_ENUM;
959   IdentifierInfo *kw_NS_OPTIONS;
960   IdentifierInfo *kw___except;
961   IdentifierInfo *kw___has_include;
962   IdentifierInfo *kw___has_include_next;
963 
964   // JavaScript keywords.
965   IdentifierInfo *kw_as;
966   IdentifierInfo *kw_async;
967   IdentifierInfo *kw_await;
968   IdentifierInfo *kw_declare;
969   IdentifierInfo *kw_finally;
970   IdentifierInfo *kw_from;
971   IdentifierInfo *kw_function;
972   IdentifierInfo *kw_get;
973   IdentifierInfo *kw_import;
974   IdentifierInfo *kw_infer;
975   IdentifierInfo *kw_is;
976   IdentifierInfo *kw_let;
977   IdentifierInfo *kw_module;
978   IdentifierInfo *kw_readonly;
979   IdentifierInfo *kw_set;
980   IdentifierInfo *kw_type;
981   IdentifierInfo *kw_typeof;
982   IdentifierInfo *kw_var;
983   IdentifierInfo *kw_yield;
984 
985   // Java keywords.
986   IdentifierInfo *kw_abstract;
987   IdentifierInfo *kw_assert;
988   IdentifierInfo *kw_extends;
989   IdentifierInfo *kw_implements;
990   IdentifierInfo *kw_instanceof;
991   IdentifierInfo *kw_interface;
992   IdentifierInfo *kw_native;
993   IdentifierInfo *kw_package;
994   IdentifierInfo *kw_synchronized;
995   IdentifierInfo *kw_throws;
996 
997   // Pragma keywords.
998   IdentifierInfo *kw_mark;
999 
1000   // Proto keywords.
1001   IdentifierInfo *kw_extend;
1002   IdentifierInfo *kw_option;
1003   IdentifierInfo *kw_optional;
1004   IdentifierInfo *kw_repeated;
1005   IdentifierInfo *kw_required;
1006   IdentifierInfo *kw_returns;
1007 
1008   // QT keywords.
1009   IdentifierInfo *kw_signals;
1010   IdentifierInfo *kw_qsignals;
1011   IdentifierInfo *kw_slots;
1012   IdentifierInfo *kw_qslots;
1013 
1014   // C# keywords
1015   IdentifierInfo *kw_dollar;
1016   IdentifierInfo *kw_base;
1017   IdentifierInfo *kw_byte;
1018   IdentifierInfo *kw_checked;
1019   IdentifierInfo *kw_decimal;
1020   IdentifierInfo *kw_delegate;
1021   IdentifierInfo *kw_event;
1022   IdentifierInfo *kw_fixed;
1023   IdentifierInfo *kw_foreach;
1024   IdentifierInfo *kw_implicit;
1025   IdentifierInfo *kw_internal;
1026 
1027   IdentifierInfo *kw_lock;
1028   IdentifierInfo *kw_null;
1029   IdentifierInfo *kw_object;
1030   IdentifierInfo *kw_out;
1031 
1032   IdentifierInfo *kw_params;
1033 
1034   IdentifierInfo *kw_ref;
1035   IdentifierInfo *kw_string;
1036   IdentifierInfo *kw_stackalloc;
1037   IdentifierInfo *kw_sbyte;
1038   IdentifierInfo *kw_sealed;
1039   IdentifierInfo *kw_uint;
1040   IdentifierInfo *kw_ulong;
1041   IdentifierInfo *kw_unchecked;
1042   IdentifierInfo *kw_unsafe;
1043   IdentifierInfo *kw_ushort;
1044   IdentifierInfo *kw_when;
1045   IdentifierInfo *kw_where;
1046 
1047   /// Returns \c true if \p Tok is a true JavaScript identifier, returns
1048   /// \c false if it is a keyword or a pseudo keyword.
1049   /// If \c AcceptIdentifierName is true, returns true not only for keywords,
1050   // but also for IdentifierName tokens (aka pseudo-keywords), such as
1051   // ``yield``.
1052   bool IsJavaScriptIdentifier(const FormatToken &Tok,
1053                               bool AcceptIdentifierName = true) const {
1054     // Based on the list of JavaScript & TypeScript keywords here:
1055     // https://github.com/microsoft/TypeScript/blob/master/src/compiler/scanner.ts#L74
1056     switch (Tok.Tok.getKind()) {
1057     case tok::kw_break:
1058     case tok::kw_case:
1059     case tok::kw_catch:
1060     case tok::kw_class:
1061     case tok::kw_continue:
1062     case tok::kw_const:
1063     case tok::kw_default:
1064     case tok::kw_delete:
1065     case tok::kw_do:
1066     case tok::kw_else:
1067     case tok::kw_enum:
1068     case tok::kw_export:
1069     case tok::kw_false:
1070     case tok::kw_for:
1071     case tok::kw_if:
1072     case tok::kw_import:
1073     case tok::kw_module:
1074     case tok::kw_new:
1075     case tok::kw_private:
1076     case tok::kw_protected:
1077     case tok::kw_public:
1078     case tok::kw_return:
1079     case tok::kw_static:
1080     case tok::kw_switch:
1081     case tok::kw_this:
1082     case tok::kw_throw:
1083     case tok::kw_true:
1084     case tok::kw_try:
1085     case tok::kw_typeof:
1086     case tok::kw_void:
1087     case tok::kw_while:
1088       // These are JS keywords that are lexed by LLVM/clang as keywords.
1089       return false;
1090     case tok::identifier: {
1091       // For identifiers, make sure they are true identifiers, excluding the
1092       // JavaScript pseudo-keywords (not lexed by LLVM/clang as keywords).
1093       bool IsPseudoKeyword =
1094           JsExtraKeywords.find(Tok.Tok.getIdentifierInfo()) !=
1095           JsExtraKeywords.end();
1096       return AcceptIdentifierName || !IsPseudoKeyword;
1097     }
1098     default:
1099       // Other keywords are handled in the switch below, to avoid problems due
1100       // to duplicate case labels when using the #include trick.
1101       break;
1102     }
1103 
1104     switch (Tok.Tok.getKind()) {
1105       // Handle C++ keywords not included above: these are all JS identifiers.
1106 #define KEYWORD(X, Y) case tok::kw_##X:
1107 #include "clang/Basic/TokenKinds.def"
1108       // #undef KEYWORD is not needed -- it's #undef-ed at the end of
1109       // TokenKinds.def
1110       return true;
1111     default:
1112       // All other tokens (punctuation etc) are not JS identifiers.
1113       return false;
1114     }
1115   }
1116 
1117   /// Returns \c true if \p Tok is a C# keyword, returns
1118   /// \c false if it is a anything else.
1119   bool isCSharpKeyword(const FormatToken &Tok) const {
1120     switch (Tok.Tok.getKind()) {
1121     case tok::kw_bool:
1122     case tok::kw_break:
1123     case tok::kw_case:
1124     case tok::kw_catch:
1125     case tok::kw_char:
1126     case tok::kw_class:
1127     case tok::kw_const:
1128     case tok::kw_continue:
1129     case tok::kw_default:
1130     case tok::kw_do:
1131     case tok::kw_double:
1132     case tok::kw_else:
1133     case tok::kw_enum:
1134     case tok::kw_explicit:
1135     case tok::kw_extern:
1136     case tok::kw_false:
1137     case tok::kw_float:
1138     case tok::kw_for:
1139     case tok::kw_goto:
1140     case tok::kw_if:
1141     case tok::kw_int:
1142     case tok::kw_long:
1143     case tok::kw_namespace:
1144     case tok::kw_new:
1145     case tok::kw_operator:
1146     case tok::kw_private:
1147     case tok::kw_protected:
1148     case tok::kw_public:
1149     case tok::kw_return:
1150     case tok::kw_short:
1151     case tok::kw_sizeof:
1152     case tok::kw_static:
1153     case tok::kw_struct:
1154     case tok::kw_switch:
1155     case tok::kw_this:
1156     case tok::kw_throw:
1157     case tok::kw_true:
1158     case tok::kw_try:
1159     case tok::kw_typeof:
1160     case tok::kw_using:
1161     case tok::kw_virtual:
1162     case tok::kw_void:
1163     case tok::kw_volatile:
1164     case tok::kw_while:
1165       return true;
1166     default:
1167       return Tok.is(tok::identifier) &&
1168              CSharpExtraKeywords.find(Tok.Tok.getIdentifierInfo()) ==
1169                  CSharpExtraKeywords.end();
1170     }
1171   }
1172 
1173 private:
1174   /// The JavaScript keywords beyond the C++ keyword set.
1175   std::unordered_set<IdentifierInfo *> JsExtraKeywords;
1176 
1177   /// The C# keywords beyond the C++ keyword set
1178   std::unordered_set<IdentifierInfo *> CSharpExtraKeywords;
1179 };
1180 
1181 } // namespace format
1182 } // namespace clang
1183 
1184 #endif
1185