1//===--- FormatTokenLexer.cpp - Lex FormatTokens -------------*- 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 implements FormatTokenLexer, which tokenizes a source file
12/// into a FormatToken stream suitable for ClangFormat.
13///
14//===----------------------------------------------------------------------===//
15
16#include "FormatTokenLexer.h"
17#include "FormatToken.h"
18#include "clang/Basic/SourceLocation.h"
19#include "clang/Basic/SourceManager.h"
20#include "clang/Format/Format.h"
21#include "llvm/Support/Regex.h"
22
23namespace clang {
24namespace format {
25
26FormatTokenLexer::FormatTokenLexer(const SourceManager &SourceMgr, FileID ID,
27                                   const FormatStyle &Style,
28                                   encoding::Encoding Encoding)
29    : FormatTok(nullptr), IsFirstToken(true), GreaterStashed(false),
30      LessStashed(false), Column(0), TrailingWhitespace(0),
31      SourceMgr(SourceMgr), ID(ID), Style(Style),
32      IdentTable(getFormattingLangOpts(Style)), Keywords(IdentTable),
33      Encoding(Encoding), FirstInLineIndex(0), FormattingDisabled(false),
34      MacroBlockBeginRegex(Style.MacroBlockBegin),
35      MacroBlockEndRegex(Style.MacroBlockEnd) {
36  Lex.reset(new Lexer(ID, SourceMgr.getBuffer(ID), SourceMgr,
37                      getFormattingLangOpts(Style)));
38  Lex->SetKeepWhitespaceMode(true);
39
40  for (const std::string &ForEachMacro : Style.ForEachMacros)
41    ForEachMacros.push_back(&IdentTable.get(ForEachMacro));
42  std::sort(ForEachMacros.begin(), ForEachMacros.end());
43}
44
45ArrayRef<FormatToken *> FormatTokenLexer::lex() {
46  assert(Tokens.empty());
47  assert(FirstInLineIndex == 0);
48  do {
49    Tokens.push_back(getNextToken());
50    if (Style.Language == FormatStyle::LK_JavaScript) {
51      tryParseJSRegexLiteral();
52      tryParseTemplateString();
53    }
54    tryMergePreviousTokens();
55    if (Tokens.back()->NewlinesBefore > 0 || Tokens.back()->IsMultiline)
56      FirstInLineIndex = Tokens.size() - 1;
57  } while (Tokens.back()->Tok.isNot(tok::eof));
58  return Tokens;
59}
60
61void FormatTokenLexer::tryMergePreviousTokens() {
62  if (tryMerge_TMacro())
63    return;
64  if (tryMergeConflictMarkers())
65    return;
66  if (tryMergeLessLess())
67    return;
68
69  if (Style.Language == FormatStyle::LK_JavaScript) {
70    static const tok::TokenKind JSIdentity[] = {tok::equalequal, tok::equal};
71    static const tok::TokenKind JSNotIdentity[] = {tok::exclaimequal,
72                                                   tok::equal};
73    static const tok::TokenKind JSShiftEqual[] = {tok::greater, tok::greater,
74                                                  tok::greaterequal};
75    static const tok::TokenKind JSRightArrow[] = {tok::equal, tok::greater};
76    // FIXME: Investigate what token type gives the correct operator priority.
77    if (tryMergeTokens(JSIdentity, TT_BinaryOperator))
78      return;
79    if (tryMergeTokens(JSNotIdentity, TT_BinaryOperator))
80      return;
81    if (tryMergeTokens(JSShiftEqual, TT_BinaryOperator))
82      return;
83    if (tryMergeTokens(JSRightArrow, TT_JsFatArrow))
84      return;
85  }
86}
87
88bool FormatTokenLexer::tryMergeLessLess() {
89  // Merge X,less,less,Y into X,lessless,Y unless X or Y is less.
90  if (Tokens.size() < 3)
91    return false;
92
93  bool FourthTokenIsLess = false;
94  if (Tokens.size() > 3)
95    FourthTokenIsLess = (Tokens.end() - 4)[0]->is(tok::less);
96
97  auto First = Tokens.end() - 3;
98  if (First[2]->is(tok::less) || First[1]->isNot(tok::less) ||
99      First[0]->isNot(tok::less) || FourthTokenIsLess)
100    return false;
101
102  // Only merge if there currently is no whitespace between the two "<".
103  if (First[1]->WhitespaceRange.getBegin() !=
104      First[1]->WhitespaceRange.getEnd())
105    return false;
106
107  First[0]->Tok.setKind(tok::lessless);
108  First[0]->TokenText = "<<";
109  First[0]->ColumnWidth += 1;
110  Tokens.erase(Tokens.end() - 2);
111  return true;
112}
113
114bool FormatTokenLexer::tryMergeTokens(ArrayRef<tok::TokenKind> Kinds,
115                                      TokenType NewType) {
116  if (Tokens.size() < Kinds.size())
117    return false;
118
119  SmallVectorImpl<FormatToken *>::const_iterator First =
120      Tokens.end() - Kinds.size();
121  if (!First[0]->is(Kinds[0]))
122    return false;
123  unsigned AddLength = 0;
124  for (unsigned i = 1; i < Kinds.size(); ++i) {
125    if (!First[i]->is(Kinds[i]) ||
126        First[i]->WhitespaceRange.getBegin() !=
127            First[i]->WhitespaceRange.getEnd())
128      return false;
129    AddLength += First[i]->TokenText.size();
130  }
131  Tokens.resize(Tokens.size() - Kinds.size() + 1);
132  First[0]->TokenText = StringRef(First[0]->TokenText.data(),
133                                  First[0]->TokenText.size() + AddLength);
134  First[0]->ColumnWidth += AddLength;
135  First[0]->Type = NewType;
136  return true;
137}
138
139// Returns \c true if \p Tok can only be followed by an operand in JavaScript.
140bool FormatTokenLexer::precedesOperand(FormatToken *Tok) {
141  // NB: This is not entirely correct, as an r_paren can introduce an operand
142  // location in e.g. `if (foo) /bar/.exec(...);`. That is a rare enough
143  // corner case to not matter in practice, though.
144  return Tok->isOneOf(tok::period, tok::l_paren, tok::comma, tok::l_brace,
145                      tok::r_brace, tok::l_square, tok::semi, tok::exclaim,
146                      tok::colon, tok::question, tok::tilde) ||
147         Tok->isOneOf(tok::kw_return, tok::kw_do, tok::kw_case, tok::kw_throw,
148                      tok::kw_else, tok::kw_new, tok::kw_delete, tok::kw_void,
149                      tok::kw_typeof, Keywords.kw_instanceof, Keywords.kw_in) ||
150         Tok->isBinaryOperator();
151}
152
153bool FormatTokenLexer::canPrecedeRegexLiteral(FormatToken *Prev) {
154  if (!Prev)
155    return true;
156
157  // Regex literals can only follow after prefix unary operators, not after
158  // postfix unary operators. If the '++' is followed by a non-operand
159  // introducing token, the slash here is the operand and not the start of a
160  // regex.
161  if (Prev->isOneOf(tok::plusplus, tok::minusminus))
162    return (Tokens.size() < 3 || precedesOperand(Tokens[Tokens.size() - 3]));
163
164  // The previous token must introduce an operand location where regex
165  // literals can occur.
166  if (!precedesOperand(Prev))
167    return false;
168
169  return true;
170}
171
172// Tries to parse a JavaScript Regex literal starting at the current token,
173// if that begins with a slash and is in a location where JavaScript allows
174// regex literals. Changes the current token to a regex literal and updates
175// its text if successful.
176void FormatTokenLexer::tryParseJSRegexLiteral() {
177  FormatToken *RegexToken = Tokens.back();
178  if (!RegexToken->isOneOf(tok::slash, tok::slashequal))
179    return;
180
181  FormatToken *Prev = nullptr;
182  for (auto I = Tokens.rbegin() + 1, E = Tokens.rend(); I != E; ++I) {
183    // NB: Because previous pointers are not initialized yet, this cannot use
184    // Token.getPreviousNonComment.
185    if ((*I)->isNot(tok::comment)) {
186      Prev = *I;
187      break;
188    }
189  }
190
191  if (!canPrecedeRegexLiteral(Prev))
192    return;
193
194  // 'Manually' lex ahead in the current file buffer.
195  const char *Offset = Lex->getBufferLocation();
196  const char *RegexBegin = Offset - RegexToken->TokenText.size();
197  StringRef Buffer = Lex->getBuffer();
198  bool InCharacterClass = false;
199  bool HaveClosingSlash = false;
200  for (; !HaveClosingSlash && Offset != Buffer.end(); ++Offset) {
201    // Regular expressions are terminated with a '/', which can only be
202    // escaped using '\' or a character class between '[' and ']'.
203    // See http://www.ecma-international.org/ecma-262/5.1/#sec-7.8.5.
204    switch (*Offset) {
205    case '\\':
206      // Skip the escaped character.
207      ++Offset;
208      break;
209    case '[':
210      InCharacterClass = true;
211      break;
212    case ']':
213      InCharacterClass = false;
214      break;
215    case '/':
216      if (!InCharacterClass)
217        HaveClosingSlash = true;
218      break;
219    }
220  }
221
222  RegexToken->Type = TT_RegexLiteral;
223  // Treat regex literals like other string_literals.
224  RegexToken->Tok.setKind(tok::string_literal);
225  RegexToken->TokenText = StringRef(RegexBegin, Offset - RegexBegin);
226  RegexToken->ColumnWidth = RegexToken->TokenText.size();
227
228  resetLexer(SourceMgr.getFileOffset(Lex->getSourceLocation(Offset)));
229}
230
231void FormatTokenLexer::tryParseTemplateString() {
232  FormatToken *BacktickToken = Tokens.back();
233  if (!BacktickToken->is(tok::unknown) || BacktickToken->TokenText != "`")
234    return;
235
236  // 'Manually' lex ahead in the current file buffer.
237  const char *Offset = Lex->getBufferLocation();
238  const char *TmplBegin = Offset - BacktickToken->TokenText.size(); // at "`"
239  for (; Offset != Lex->getBuffer().end() && *Offset != '`'; ++Offset) {
240    if (*Offset == '\\')
241      ++Offset; // Skip the escaped character.
242  }
243
244  StringRef LiteralText(TmplBegin, Offset - TmplBegin + 1);
245  BacktickToken->Type = TT_TemplateString;
246  BacktickToken->Tok.setKind(tok::string_literal);
247  BacktickToken->TokenText = LiteralText;
248
249  // Adjust width for potentially multiline string literals.
250  size_t FirstBreak = LiteralText.find('\n');
251  StringRef FirstLineText = FirstBreak == StringRef::npos
252                                ? LiteralText
253                                : LiteralText.substr(0, FirstBreak);
254  BacktickToken->ColumnWidth = encoding::columnWidthWithTabs(
255      FirstLineText, BacktickToken->OriginalColumn, Style.TabWidth, Encoding);
256  size_t LastBreak = LiteralText.rfind('\n');
257  if (LastBreak != StringRef::npos) {
258    BacktickToken->IsMultiline = true;
259    unsigned StartColumn = 0; // The template tail spans the entire line.
260    BacktickToken->LastLineColumnWidth = encoding::columnWidthWithTabs(
261        LiteralText.substr(LastBreak + 1, LiteralText.size()), StartColumn,
262        Style.TabWidth, Encoding);
263  }
264
265  resetLexer(SourceMgr.getFileOffset(Lex->getSourceLocation(Offset + 1)));
266}
267
268bool FormatTokenLexer::tryMerge_TMacro() {
269  if (Tokens.size() < 4)
270    return false;
271  FormatToken *Last = Tokens.back();
272  if (!Last->is(tok::r_paren))
273    return false;
274
275  FormatToken *String = Tokens[Tokens.size() - 2];
276  if (!String->is(tok::string_literal) || String->IsMultiline)
277    return false;
278
279  if (!Tokens[Tokens.size() - 3]->is(tok::l_paren))
280    return false;
281
282  FormatToken *Macro = Tokens[Tokens.size() - 4];
283  if (Macro->TokenText != "_T")
284    return false;
285
286  const char *Start = Macro->TokenText.data();
287  const char *End = Last->TokenText.data() + Last->TokenText.size();
288  String->TokenText = StringRef(Start, End - Start);
289  String->IsFirst = Macro->IsFirst;
290  String->LastNewlineOffset = Macro->LastNewlineOffset;
291  String->WhitespaceRange = Macro->WhitespaceRange;
292  String->OriginalColumn = Macro->OriginalColumn;
293  String->ColumnWidth = encoding::columnWidthWithTabs(
294      String->TokenText, String->OriginalColumn, Style.TabWidth, Encoding);
295  String->NewlinesBefore = Macro->NewlinesBefore;
296  String->HasUnescapedNewline = Macro->HasUnescapedNewline;
297
298  Tokens.pop_back();
299  Tokens.pop_back();
300  Tokens.pop_back();
301  Tokens.back() = String;
302  return true;
303}
304
305bool FormatTokenLexer::tryMergeConflictMarkers() {
306  if (Tokens.back()->NewlinesBefore == 0 && Tokens.back()->isNot(tok::eof))
307    return false;
308
309  // Conflict lines look like:
310  // <marker> <text from the vcs>
311  // For example:
312  // >>>>>>> /file/in/file/system at revision 1234
313  //
314  // We merge all tokens in a line that starts with a conflict marker
315  // into a single token with a special token type that the unwrapped line
316  // parser will use to correctly rebuild the underlying code.
317
318  FileID ID;
319  // Get the position of the first token in the line.
320  unsigned FirstInLineOffset;
321  std::tie(ID, FirstInLineOffset) = SourceMgr.getDecomposedLoc(
322      Tokens[FirstInLineIndex]->getStartOfNonWhitespace());
323  StringRef Buffer = SourceMgr.getBuffer(ID)->getBuffer();
324  // Calculate the offset of the start of the current line.
325  auto LineOffset = Buffer.rfind('\n', FirstInLineOffset);
326  if (LineOffset == StringRef::npos) {
327    LineOffset = 0;
328  } else {
329    ++LineOffset;
330  }
331
332  auto FirstSpace = Buffer.find_first_of(" \n", LineOffset);
333  StringRef LineStart;
334  if (FirstSpace == StringRef::npos) {
335    LineStart = Buffer.substr(LineOffset);
336  } else {
337    LineStart = Buffer.substr(LineOffset, FirstSpace - LineOffset);
338  }
339
340  TokenType Type = TT_Unknown;
341  if (LineStart == "<<<<<<<" || LineStart == ">>>>") {
342    Type = TT_ConflictStart;
343  } else if (LineStart == "|||||||" || LineStart == "=======" ||
344             LineStart == "====") {
345    Type = TT_ConflictAlternative;
346  } else if (LineStart == ">>>>>>>" || LineStart == "<<<<") {
347    Type = TT_ConflictEnd;
348  }
349
350  if (Type != TT_Unknown) {
351    FormatToken *Next = Tokens.back();
352
353    Tokens.resize(FirstInLineIndex + 1);
354    // We do not need to build a complete token here, as we will skip it
355    // during parsing anyway (as we must not touch whitespace around conflict
356    // markers).
357    Tokens.back()->Type = Type;
358    Tokens.back()->Tok.setKind(tok::kw___unknown_anytype);
359
360    Tokens.push_back(Next);
361    return true;
362  }
363
364  return false;
365}
366
367FormatToken *FormatTokenLexer::getStashedToken() {
368  // Create a synthesized second '>' or '<' token.
369  Token Tok = FormatTok->Tok;
370  StringRef TokenText = FormatTok->TokenText;
371
372  unsigned OriginalColumn = FormatTok->OriginalColumn;
373  FormatTok = new (Allocator.Allocate()) FormatToken;
374  FormatTok->Tok = Tok;
375  SourceLocation TokLocation =
376      FormatTok->Tok.getLocation().getLocWithOffset(Tok.getLength() - 1);
377  FormatTok->Tok.setLocation(TokLocation);
378  FormatTok->WhitespaceRange = SourceRange(TokLocation, TokLocation);
379  FormatTok->TokenText = TokenText;
380  FormatTok->ColumnWidth = 1;
381  FormatTok->OriginalColumn = OriginalColumn + 1;
382
383  return FormatTok;
384}
385
386FormatToken *FormatTokenLexer::getNextToken() {
387  if (GreaterStashed) {
388    GreaterStashed = false;
389    return getStashedToken();
390  }
391  if (LessStashed) {
392    LessStashed = false;
393    return getStashedToken();
394  }
395
396  FormatTok = new (Allocator.Allocate()) FormatToken;
397  readRawToken(*FormatTok);
398  SourceLocation WhitespaceStart =
399      FormatTok->Tok.getLocation().getLocWithOffset(-TrailingWhitespace);
400  FormatTok->IsFirst = IsFirstToken;
401  IsFirstToken = false;
402
403  // Consume and record whitespace until we find a significant token.
404  unsigned WhitespaceLength = TrailingWhitespace;
405  while (FormatTok->Tok.is(tok::unknown)) {
406    StringRef Text = FormatTok->TokenText;
407    auto EscapesNewline = [&](int pos) {
408      // A '\r' here is just part of '\r\n'. Skip it.
409      if (pos >= 0 && Text[pos] == '\r')
410        --pos;
411      // See whether there is an odd number of '\' before this.
412      unsigned count = 0;
413      for (; pos >= 0; --pos, ++count)
414        if (Text[pos] != '\\')
415          break;
416      return count & 1;
417    };
418    // FIXME: This miscounts tok:unknown tokens that are not just
419    // whitespace, e.g. a '`' character.
420    for (int i = 0, e = Text.size(); i != e; ++i) {
421      switch (Text[i]) {
422      case '\n':
423        ++FormatTok->NewlinesBefore;
424        FormatTok->HasUnescapedNewline = !EscapesNewline(i - 1);
425        FormatTok->LastNewlineOffset = WhitespaceLength + i + 1;
426        Column = 0;
427        break;
428      case '\r':
429        FormatTok->LastNewlineOffset = WhitespaceLength + i + 1;
430        Column = 0;
431        break;
432      case '\f':
433      case '\v':
434        Column = 0;
435        break;
436      case ' ':
437        ++Column;
438        break;
439      case '\t':
440        Column += Style.TabWidth - Column % Style.TabWidth;
441        break;
442      case '\\':
443        if (i + 1 == e || (Text[i + 1] != '\r' && Text[i + 1] != '\n'))
444          FormatTok->Type = TT_ImplicitStringLiteral;
445        break;
446      default:
447        FormatTok->Type = TT_ImplicitStringLiteral;
448        break;
449      }
450      if (FormatTok->Type == TT_ImplicitStringLiteral)
451        break;
452    }
453
454    if (FormatTok->is(TT_ImplicitStringLiteral))
455      break;
456    WhitespaceLength += FormatTok->Tok.getLength();
457
458    readRawToken(*FormatTok);
459  }
460
461  // In case the token starts with escaped newlines, we want to
462  // take them into account as whitespace - this pattern is quite frequent
463  // in macro definitions.
464  // FIXME: Add a more explicit test.
465  while (FormatTok->TokenText.size() > 1 && FormatTok->TokenText[0] == '\\' &&
466         FormatTok->TokenText[1] == '\n') {
467    ++FormatTok->NewlinesBefore;
468    WhitespaceLength += 2;
469    FormatTok->LastNewlineOffset = 2;
470    Column = 0;
471    FormatTok->TokenText = FormatTok->TokenText.substr(2);
472  }
473
474  FormatTok->WhitespaceRange = SourceRange(
475      WhitespaceStart, WhitespaceStart.getLocWithOffset(WhitespaceLength));
476
477  FormatTok->OriginalColumn = Column;
478
479  TrailingWhitespace = 0;
480  if (FormatTok->Tok.is(tok::comment)) {
481    // FIXME: Add the trimmed whitespace to Column.
482    StringRef UntrimmedText = FormatTok->TokenText;
483    FormatTok->TokenText = FormatTok->TokenText.rtrim(" \t\v\f");
484    TrailingWhitespace = UntrimmedText.size() - FormatTok->TokenText.size();
485  } else if (FormatTok->Tok.is(tok::raw_identifier)) {
486    IdentifierInfo &Info = IdentTable.get(FormatTok->TokenText);
487    FormatTok->Tok.setIdentifierInfo(&Info);
488    FormatTok->Tok.setKind(Info.getTokenID());
489    if (Style.Language == FormatStyle::LK_Java &&
490        FormatTok->isOneOf(tok::kw_struct, tok::kw_union, tok::kw_delete,
491                           tok::kw_operator)) {
492      FormatTok->Tok.setKind(tok::identifier);
493      FormatTok->Tok.setIdentifierInfo(nullptr);
494    } else if (Style.Language == FormatStyle::LK_JavaScript &&
495               FormatTok->isOneOf(tok::kw_struct, tok::kw_union,
496                                  tok::kw_operator)) {
497      FormatTok->Tok.setKind(tok::identifier);
498      FormatTok->Tok.setIdentifierInfo(nullptr);
499    }
500  } else if (FormatTok->Tok.is(tok::greatergreater)) {
501    FormatTok->Tok.setKind(tok::greater);
502    FormatTok->TokenText = FormatTok->TokenText.substr(0, 1);
503    GreaterStashed = true;
504  } else if (FormatTok->Tok.is(tok::lessless)) {
505    FormatTok->Tok.setKind(tok::less);
506    FormatTok->TokenText = FormatTok->TokenText.substr(0, 1);
507    LessStashed = true;
508  }
509
510  // Now FormatTok is the next non-whitespace token.
511
512  StringRef Text = FormatTok->TokenText;
513  size_t FirstNewlinePos = Text.find('\n');
514  if (FirstNewlinePos == StringRef::npos) {
515    // FIXME: ColumnWidth actually depends on the start column, we need to
516    // take this into account when the token is moved.
517    FormatTok->ColumnWidth =
518        encoding::columnWidthWithTabs(Text, Column, Style.TabWidth, Encoding);
519    Column += FormatTok->ColumnWidth;
520  } else {
521    FormatTok->IsMultiline = true;
522    // FIXME: ColumnWidth actually depends on the start column, we need to
523    // take this into account when the token is moved.
524    FormatTok->ColumnWidth = encoding::columnWidthWithTabs(
525        Text.substr(0, FirstNewlinePos), Column, Style.TabWidth, Encoding);
526
527    // The last line of the token always starts in column 0.
528    // Thus, the length can be precomputed even in the presence of tabs.
529    FormatTok->LastLineColumnWidth = encoding::columnWidthWithTabs(
530        Text.substr(Text.find_last_of('\n') + 1), 0, Style.TabWidth, Encoding);
531    Column = FormatTok->LastLineColumnWidth;
532  }
533
534  if (Style.Language == FormatStyle::LK_Cpp) {
535    if (!(Tokens.size() > 0 && Tokens.back()->Tok.getIdentifierInfo() &&
536          Tokens.back()->Tok.getIdentifierInfo()->getPPKeywordID() ==
537              tok::pp_define) &&
538        std::find(ForEachMacros.begin(), ForEachMacros.end(),
539                  FormatTok->Tok.getIdentifierInfo()) != ForEachMacros.end()) {
540      FormatTok->Type = TT_ForEachMacro;
541    } else if (FormatTok->is(tok::identifier)) {
542      if (MacroBlockBeginRegex.match(Text)) {
543        FormatTok->Type = TT_MacroBlockBegin;
544      } else if (MacroBlockEndRegex.match(Text)) {
545        FormatTok->Type = TT_MacroBlockEnd;
546      }
547    }
548  }
549
550  return FormatTok;
551}
552
553void FormatTokenLexer::readRawToken(FormatToken &Tok) {
554  Lex->LexFromRawLexer(Tok.Tok);
555  Tok.TokenText = StringRef(SourceMgr.getCharacterData(Tok.Tok.getLocation()),
556                            Tok.Tok.getLength());
557  // For formatting, treat unterminated string literals like normal string
558  // literals.
559  if (Tok.is(tok::unknown)) {
560    if (!Tok.TokenText.empty() && Tok.TokenText[0] == '"') {
561      Tok.Tok.setKind(tok::string_literal);
562      Tok.IsUnterminatedLiteral = true;
563    } else if (Style.Language == FormatStyle::LK_JavaScript &&
564               Tok.TokenText == "''") {
565      Tok.Tok.setKind(tok::string_literal);
566    }
567  }
568
569  if (Style.Language == FormatStyle::LK_JavaScript &&
570      Tok.is(tok::char_constant)) {
571    Tok.Tok.setKind(tok::string_literal);
572  }
573
574  if (Tok.is(tok::comment) && (Tok.TokenText == "// clang-format on" ||
575                               Tok.TokenText == "/* clang-format on */")) {
576    FormattingDisabled = false;
577  }
578
579  Tok.Finalized = FormattingDisabled;
580
581  if (Tok.is(tok::comment) && (Tok.TokenText == "// clang-format off" ||
582                               Tok.TokenText == "/* clang-format off */")) {
583    FormattingDisabled = true;
584  }
585}
586
587void FormatTokenLexer::resetLexer(unsigned Offset) {
588  StringRef Buffer = SourceMgr.getBufferData(ID);
589  Lex.reset(new Lexer(SourceMgr.getLocForStartOfFile(ID),
590                      getFormattingLangOpts(Style), Buffer.begin(),
591                      Buffer.begin() + Offset, Buffer.end()));
592  Lex->SetKeepWhitespaceMode(true);
593  TrailingWhitespace = 0;
594}
595
596} // namespace format
597} // namespace clang
598