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