1//===--- FormatToken.h - Format C++ code ------------------------*- C++ -*-===//
2//
3//                     The LLVM Compiler Infrastructure
4//
5// This file is distributed under the University of Illinois Open Source
6// License. See LICENSE.TXT for details.
7//
8//===----------------------------------------------------------------------===//
9///
10/// \file
11/// \brief This file contains the declaration of the FormatToken, a wrapper
12/// around Token with additional information related to formatting.
13///
14//===----------------------------------------------------------------------===//
15
16#ifndef LLVM_CLANG_FORMAT_FORMAT_TOKEN_H
17#define LLVM_CLANG_FORMAT_FORMAT_TOKEN_H
18
19#include "clang/Basic/OperatorPrecedence.h"
20#include "clang/Format/Format.h"
21#include "clang/Lex/Lexer.h"
22#include <memory>
23
24namespace clang {
25namespace format {
26
27enum TokenType {
28  TT_ArrayInitializerLSquare,
29  TT_ArraySubscriptLSquare,
30  TT_AttributeParen,
31  TT_BinaryOperator,
32  TT_BitFieldColon,
33  TT_BlockComment,
34  TT_CastRParen,
35  TT_ConditionalExpr,
36  TT_ConflictAlternative,
37  TT_ConflictEnd,
38  TT_ConflictStart,
39  TT_CtorInitializerColon,
40  TT_CtorInitializerComma,
41  TT_DesignatedInitializerPeriod,
42  TT_DictLiteral,
43  TT_FunctionDeclarationName,
44  TT_FunctionLBrace,
45  TT_FunctionTypeLParen,
46  TT_ImplicitStringLiteral,
47  TT_InheritanceColon,
48  TT_InlineASMColon,
49  TT_LambdaLSquare,
50  TT_LineComment,
51  TT_ObjCBlockLBrace,
52  TT_ObjCBlockLParen,
53  TT_ObjCDecl,
54  TT_ObjCForIn,
55  TT_ObjCMethodExpr,
56  TT_ObjCMethodSpecifier,
57  TT_ObjCProperty,
58  TT_OverloadedOperator,
59  TT_OverloadedOperatorLParen,
60  TT_PointerOrReference,
61  TT_PureVirtualSpecifier,
62  TT_RangeBasedForLoopColon,
63  TT_RegexLiteral,
64  TT_SelectorName,
65  TT_StartOfName,
66  TT_TemplateCloser,
67  TT_TemplateOpener,
68  TT_TrailingAnnotation,
69  TT_TrailingReturnArrow,
70  TT_TrailingUnaryOperator,
71  TT_UnaryOperator,
72  TT_Unknown
73};
74
75// Represents what type of block a set of braces open.
76enum BraceBlockKind {
77  BK_Unknown,
78  BK_Block,
79  BK_BracedInit
80};
81
82// The packing kind of a function's parameters.
83enum ParameterPackingKind {
84  PPK_BinPacked,
85  PPK_OnePerLine,
86  PPK_Inconclusive
87};
88
89enum FormatDecision {
90  FD_Unformatted,
91  FD_Continue,
92  FD_Break
93};
94
95class TokenRole;
96class AnnotatedLine;
97
98/// \brief A wrapper around a \c Token storing information about the
99/// whitespace characters preceding it.
100struct FormatToken {
101  FormatToken()
102      : NewlinesBefore(0), HasUnescapedNewline(false), LastNewlineOffset(0),
103        ColumnWidth(0), LastLineColumnWidth(0), IsMultiline(false),
104        IsFirst(false), MustBreakBefore(false), IsUnterminatedLiteral(false),
105        BlockKind(BK_Unknown), Type(TT_Unknown), SpacesRequiredBefore(0),
106        CanBreakBefore(false), ClosesTemplateDeclaration(false),
107        ParameterCount(0), BlockParameterCount(0),
108        PackingKind(PPK_Inconclusive), TotalLength(0), UnbreakableTailLength(0),
109        BindingStrength(0), NestingLevel(0), SplitPenalty(0),
110        LongestObjCSelectorName(0), FakeRParens(0),
111        StartsBinaryExpression(false), EndsBinaryExpression(false),
112        OperatorIndex(0), LastOperator(false),
113        PartOfMultiVariableDeclStmt(false), IsForEachMacro(false),
114        MatchingParen(nullptr), Previous(nullptr), Next(nullptr),
115        Decision(FD_Unformatted), Finalized(false) {}
116
117  /// \brief The \c Token.
118  Token Tok;
119
120  /// \brief The number of newlines immediately before the \c Token.
121  ///
122  /// This can be used to determine what the user wrote in the original code
123  /// and thereby e.g. leave an empty line between two function definitions.
124  unsigned NewlinesBefore;
125
126  /// \brief Whether there is at least one unescaped newline before the \c
127  /// Token.
128  bool HasUnescapedNewline;
129
130  /// \brief The range of the whitespace immediately preceding the \c Token.
131  SourceRange WhitespaceRange;
132
133  /// \brief The offset just past the last '\n' in this token's leading
134  /// whitespace (relative to \c WhiteSpaceStart). 0 if there is no '\n'.
135  unsigned LastNewlineOffset;
136
137  /// \brief The width of the non-whitespace parts of the token (or its first
138  /// line for multi-line tokens) in columns.
139  /// We need this to correctly measure number of columns a token spans.
140  unsigned ColumnWidth;
141
142  /// \brief Contains the width in columns of the last line of a multi-line
143  /// token.
144  unsigned LastLineColumnWidth;
145
146  /// \brief Whether the token text contains newlines (escaped or not).
147  bool IsMultiline;
148
149  /// \brief Indicates that this is the first token.
150  bool IsFirst;
151
152  /// \brief Whether there must be a line break before this token.
153  ///
154  /// This happens for example when a preprocessor directive ended directly
155  /// before the token.
156  bool MustBreakBefore;
157
158  /// \brief Returns actual token start location without leading escaped
159  /// newlines and whitespace.
160  ///
161  /// This can be different to Tok.getLocation(), which includes leading escaped
162  /// newlines.
163  SourceLocation getStartOfNonWhitespace() const {
164    return WhitespaceRange.getEnd();
165  }
166
167  /// \brief The raw text of the token.
168  ///
169  /// Contains the raw token text without leading whitespace and without leading
170  /// escaped newlines.
171  StringRef TokenText;
172
173  /// \brief Set to \c true if this token is an unterminated literal.
174  bool IsUnterminatedLiteral;
175
176  /// \brief Contains the kind of block if this token is a brace.
177  BraceBlockKind BlockKind;
178
179  TokenType Type;
180
181  /// \brief The number of spaces that should be inserted before this token.
182  unsigned SpacesRequiredBefore;
183
184  /// \brief \c true if it is allowed to break before this token.
185  bool CanBreakBefore;
186
187  bool ClosesTemplateDeclaration;
188
189  /// \brief Number of parameters, if this is "(", "[" or "<".
190  ///
191  /// This is initialized to 1 as we don't need to distinguish functions with
192  /// 0 parameters from functions with 1 parameter. Thus, we can simply count
193  /// the number of commas.
194  unsigned ParameterCount;
195
196  /// \brief Number of parameters that are nested blocks,
197  /// if this is "(", "[" or "<".
198  unsigned BlockParameterCount;
199
200  /// \brief A token can have a special role that can carry extra information
201  /// about the token's formatting.
202  std::unique_ptr<TokenRole> Role;
203
204  /// \brief If this is an opening parenthesis, how are the parameters packed?
205  ParameterPackingKind PackingKind;
206
207  /// \brief The total length of the unwrapped line up to and including this
208  /// token.
209  unsigned TotalLength;
210
211  /// \brief The original 0-based column of this token, including expanded tabs.
212  /// The configured TabWidth is used as tab width.
213  unsigned OriginalColumn;
214
215  /// \brief The length of following tokens until the next natural split point,
216  /// or the next token that can be broken.
217  unsigned UnbreakableTailLength;
218
219  // FIXME: Come up with a 'cleaner' concept.
220  /// \brief The binding strength of a token. This is a combined value of
221  /// operator precedence, parenthesis nesting, etc.
222  unsigned BindingStrength;
223
224  /// \brief The nesting level of this token, i.e. the number of surrounding (),
225  /// [], {} or <>.
226  unsigned NestingLevel;
227
228  /// \brief Penalty for inserting a line break before this token.
229  unsigned SplitPenalty;
230
231  /// \brief If this is the first ObjC selector name in an ObjC method
232  /// definition or call, this contains the length of the longest name.
233  ///
234  /// This being set to 0 means that the selectors should not be colon-aligned,
235  /// e.g. because several of them are block-type.
236  unsigned LongestObjCSelectorName;
237
238  /// \brief Stores the number of required fake parentheses and the
239  /// corresponding operator precedence.
240  ///
241  /// If multiple fake parentheses start at a token, this vector stores them in
242  /// reverse order, i.e. inner fake parenthesis first.
243  SmallVector<prec::Level, 4> FakeLParens;
244  /// \brief Insert this many fake ) after this token for correct indentation.
245  unsigned FakeRParens;
246
247  /// \brief \c true if this token starts a binary expression, i.e. has at least
248  /// one fake l_paren with a precedence greater than prec::Unknown.
249  bool StartsBinaryExpression;
250  /// \brief \c true if this token ends a binary expression.
251  bool EndsBinaryExpression;
252
253  /// \brief Is this is an operator (or "."/"->") in a sequence of operators
254  /// with the same precedence, contains the 0-based operator index.
255  unsigned OperatorIndex;
256
257  /// \brief Is this the last operator (or "."/"->") in a sequence of operators
258  /// with the same precedence?
259  bool LastOperator;
260
261  /// \brief Is this token part of a \c DeclStmt defining multiple variables?
262  ///
263  /// Only set if \c Type == \c TT_StartOfName.
264  bool PartOfMultiVariableDeclStmt;
265
266  /// \brief Is this a foreach macro?
267  bool IsForEachMacro;
268
269  bool is(tok::TokenKind Kind) const { return Tok.is(Kind); }
270
271  bool isOneOf(tok::TokenKind K1, tok::TokenKind K2) const {
272    return is(K1) || is(K2);
273  }
274
275  bool isOneOf(tok::TokenKind K1, tok::TokenKind K2, tok::TokenKind K3) const {
276    return is(K1) || is(K2) || is(K3);
277  }
278
279  bool isOneOf(tok::TokenKind K1, tok::TokenKind K2, tok::TokenKind K3,
280               tok::TokenKind K4, tok::TokenKind K5 = tok::NUM_TOKENS,
281               tok::TokenKind K6 = tok::NUM_TOKENS,
282               tok::TokenKind K7 = tok::NUM_TOKENS,
283               tok::TokenKind K8 = tok::NUM_TOKENS,
284               tok::TokenKind K9 = tok::NUM_TOKENS,
285               tok::TokenKind K10 = tok::NUM_TOKENS,
286               tok::TokenKind K11 = tok::NUM_TOKENS,
287               tok::TokenKind K12 = tok::NUM_TOKENS) const {
288    return is(K1) || is(K2) || is(K3) || is(K4) || is(K5) || is(K6) || is(K7) ||
289           is(K8) || is(K9) || is(K10) || is(K11) || is(K12);
290  }
291
292  bool isNot(tok::TokenKind Kind) const { return Tok.isNot(Kind); }
293  bool isStringLiteral() const { return tok::isStringLiteral(Tok.getKind()); }
294
295  bool isObjCAtKeyword(tok::ObjCKeywordKind Kind) const {
296    return Tok.isObjCAtKeyword(Kind);
297  }
298
299  bool isAccessSpecifier(bool ColonRequired = true) const {
300    return isOneOf(tok::kw_public, tok::kw_protected, tok::kw_private) &&
301           (!ColonRequired || (Next && Next->is(tok::colon)));
302  }
303
304  /// \brief Determine whether the token is a simple-type-specifier.
305  bool isSimpleTypeSpecifier() const;
306
307  bool isObjCAccessSpecifier() const {
308    return is(tok::at) && Next && (Next->isObjCAtKeyword(tok::objc_public) ||
309                                   Next->isObjCAtKeyword(tok::objc_protected) ||
310                                   Next->isObjCAtKeyword(tok::objc_package) ||
311                                   Next->isObjCAtKeyword(tok::objc_private));
312  }
313
314  /// \brief Returns whether \p Tok is ([{ or a template opening <.
315  bool opensScope() const {
316    return isOneOf(tok::l_paren, tok::l_brace, tok::l_square) ||
317           Type == TT_TemplateOpener;
318  }
319  /// \brief Returns whether \p Tok is )]} or a template closing >.
320  bool closesScope() const {
321    return isOneOf(tok::r_paren, tok::r_brace, tok::r_square) ||
322           Type == TT_TemplateCloser;
323  }
324
325  /// \brief Returns \c true if this is a "." or "->" accessing a member.
326  bool isMemberAccess() const {
327    return isOneOf(tok::arrow, tok::period, tok::arrowstar) &&
328           Type != TT_DesignatedInitializerPeriod;
329  }
330
331  bool isUnaryOperator() const {
332    switch (Tok.getKind()) {
333    case tok::plus:
334    case tok::plusplus:
335    case tok::minus:
336    case tok::minusminus:
337    case tok::exclaim:
338    case tok::tilde:
339    case tok::kw_sizeof:
340    case tok::kw_alignof:
341      return true;
342    default:
343      return false;
344    }
345  }
346
347  bool isBinaryOperator() const {
348    // Comma is a binary operator, but does not behave as such wrt. formatting.
349    return getPrecedence() > prec::Comma;
350  }
351
352  bool isTrailingComment() const {
353    return is(tok::comment) && (!Next || Next->NewlinesBefore > 0);
354  }
355
356  prec::Level getPrecedence() const {
357    return getBinOpPrecedence(Tok.getKind(), true, true);
358  }
359
360  /// \brief Returns the previous token ignoring comments.
361  FormatToken *getPreviousNonComment() const {
362    FormatToken *Tok = Previous;
363    while (Tok && Tok->is(tok::comment))
364      Tok = Tok->Previous;
365    return Tok;
366  }
367
368  /// \brief Returns the next token ignoring comments.
369  const FormatToken *getNextNonComment() const {
370    const FormatToken *Tok = Next;
371    while (Tok && Tok->is(tok::comment))
372      Tok = Tok->Next;
373    return Tok;
374  }
375
376  /// \brief Returns \c true if this tokens starts a block-type list, i.e. a
377  /// list that should be indented with a block indent.
378  bool opensBlockTypeList(const FormatStyle &Style) const {
379    return Type == TT_ArrayInitializerLSquare ||
380           (is(tok::l_brace) &&
381            (BlockKind == BK_Block || Type == TT_DictLiteral ||
382             !Style.Cpp11BracedListStyle));
383  }
384
385  /// \brief Same as opensBlockTypeList, but for the closing token.
386  bool closesBlockTypeList(const FormatStyle &Style) const {
387    return MatchingParen && MatchingParen->opensBlockTypeList(Style);
388  }
389
390  FormatToken *MatchingParen;
391
392  FormatToken *Previous;
393  FormatToken *Next;
394
395  SmallVector<AnnotatedLine *, 1> Children;
396
397  /// \brief Stores the formatting decision for the token once it was made.
398  FormatDecision Decision;
399
400  /// \brief If \c true, this token has been fully formatted (indented and
401  /// potentially re-formatted inside), and we do not allow further formatting
402  /// changes.
403  bool Finalized;
404
405private:
406  // Disallow copying.
407  FormatToken(const FormatToken &) LLVM_DELETED_FUNCTION;
408  void operator=(const FormatToken &) LLVM_DELETED_FUNCTION;
409};
410
411class ContinuationIndenter;
412struct LineState;
413
414class TokenRole {
415public:
416  TokenRole(const FormatStyle &Style) : Style(Style) {}
417  virtual ~TokenRole();
418
419  /// \brief After the \c TokenAnnotator has finished annotating all the tokens,
420  /// this function precomputes required information for formatting.
421  virtual void precomputeFormattingInfos(const FormatToken *Token);
422
423  /// \brief Apply the special formatting that the given role demands.
424  ///
425  /// Assumes that the token having this role is already formatted.
426  ///
427  /// Continues formatting from \p State leaving indentation to \p Indenter and
428  /// returns the total penalty that this formatting incurs.
429  virtual unsigned formatFromToken(LineState &State,
430                                   ContinuationIndenter *Indenter,
431                                   bool DryRun) {
432    return 0;
433  }
434
435  /// \brief Same as \c formatFromToken, but assumes that the first token has
436  /// already been set thereby deciding on the first line break.
437  virtual unsigned formatAfterToken(LineState &State,
438                                    ContinuationIndenter *Indenter,
439                                    bool DryRun) {
440    return 0;
441  }
442
443  /// \brief Notifies the \c Role that a comma was found.
444  virtual void CommaFound(const FormatToken *Token) {}
445
446protected:
447  const FormatStyle &Style;
448};
449
450class CommaSeparatedList : public TokenRole {
451public:
452  CommaSeparatedList(const FormatStyle &Style)
453      : TokenRole(Style), HasNestedBracedList(false) {}
454
455  void precomputeFormattingInfos(const FormatToken *Token) override;
456
457  unsigned formatAfterToken(LineState &State, ContinuationIndenter *Indenter,
458                            bool DryRun) override;
459
460  unsigned formatFromToken(LineState &State, ContinuationIndenter *Indenter,
461                           bool DryRun) override;
462
463  /// \brief Adds \p Token as the next comma to the \c CommaSeparated list.
464  void CommaFound(const FormatToken *Token) override {
465    Commas.push_back(Token);
466  }
467
468private:
469  /// \brief A struct that holds information on how to format a given list with
470  /// a specific number of columns.
471  struct ColumnFormat {
472    /// \brief The number of columns to use.
473    unsigned Columns;
474
475    /// \brief The total width in characters.
476    unsigned TotalWidth;
477
478    /// \brief The number of lines required for this format.
479    unsigned LineCount;
480
481    /// \brief The size of each column in characters.
482    SmallVector<unsigned, 8> ColumnSizes;
483  };
484
485  /// \brief Calculate which \c ColumnFormat fits best into
486  /// \p RemainingCharacters.
487  const ColumnFormat *getColumnFormat(unsigned RemainingCharacters) const;
488
489  /// \brief The ordered \c FormatTokens making up the commas of this list.
490  SmallVector<const FormatToken *, 8> Commas;
491
492  /// \brief The length of each of the list's items in characters including the
493  /// trailing comma.
494  SmallVector<unsigned, 8> ItemLengths;
495
496  /// \brief Precomputed formats that can be used for this list.
497  SmallVector<ColumnFormat, 4> Formats;
498
499  bool HasNestedBracedList;
500};
501
502} // namespace format
503} // namespace clang
504
505#endif // LLVM_CLANG_FORMAT_FORMAT_TOKEN_H
506