clang  15.0.0git
Lexer.h
Go to the documentation of this file.
1 //===- Lexer.h - C Language Family Lexer ------------------------*- 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 // This file defines the Lexer interface.
10 //
11 //===----------------------------------------------------------------------===//
12 
13 #ifndef LLVM_CLANG_LEX_LEXER_H
14 #define LLVM_CLANG_LEX_LEXER_H
15 
18 #include "clang/Basic/TokenKinds.h"
21 #include "clang/Lex/Token.h"
22 #include "llvm/ADT/Optional.h"
23 #include "llvm/ADT/SmallVector.h"
24 #include "llvm/ADT/StringRef.h"
25 #include <cassert>
26 #include <cstdint>
27 #include <string>
28 
29 namespace llvm {
30 
31 class MemoryBufferRef;
32 
33 } // namespace llvm
34 
35 namespace clang {
36 
37 class DiagnosticBuilder;
38 class Preprocessor;
39 class SourceManager;
40 class LangOptions;
41 
42 /// ConflictMarkerKind - Kinds of conflict marker which the lexer might be
43 /// recovering from.
45  /// Not within a conflict marker.
47 
48  /// A normal or diff3 conflict marker, initiated by at least 7 "<"s,
49  /// separated by at least 7 "="s or "|"s, and terminated by at least 7 ">"s.
51 
52  /// A Perforce-style conflict marker, initiated by 4 ">"s,
53  /// separated by 4 "="s, and terminated by 4 "<"s.
55 };
56 
57 /// Describes the bounds (start, size) of the preamble and a flag required by
58 /// PreprocessorOptions::PrecompiledPreambleBytes.
59 /// The preamble includes the BOM, if any.
61  /// Size of the preamble in bytes.
62  unsigned Size;
63 
64  /// Whether the preamble ends at the start of a new line.
65  ///
66  /// Used to inform the lexer as to whether it's starting at the beginning of
67  /// a line after skipping the preamble.
69 
72 };
73 
74 /// Lexer - This provides a simple interface that turns a text buffer into a
75 /// stream of tokens. This provides no support for file reading or buffering,
76 /// or buffering/seeking of tokens, only forward lexing is supported. It relies
77 /// on the specified Preprocessor object to handle preprocessor directives, etc.
78 class Lexer : public PreprocessorLexer {
79  friend class Preprocessor;
80 
81  void anchor() override;
82 
83  //===--------------------------------------------------------------------===//
84  // Constant configuration values for this lexer.
85 
86  // Start of the buffer.
87  const char *BufferStart;
88 
89  // End of the buffer.
90  const char *BufferEnd;
91 
92  // Location for start of file.
93  SourceLocation FileLoc;
94 
95  // LangOpts enabled by this language.
96  // Storing LangOptions as reference here is important from performance point
97  // of view. Lack of reference means that LangOptions copy constructor would be
98  // called by Lexer(..., const LangOptions &LangOpts,...). Given that local
99  // Lexer objects are created thousands times (in Lexer::getRawToken,
100  // Preprocessor::EnterSourceFile and other places) during single module
101  // processing in frontend it would make std::vector<std::string> copy
102  // constructors surprisingly hot.
103  const LangOptions &LangOpts;
104 
105  // True if '//' line comments are enabled.
106  bool LineComment;
107 
108  // True if lexer for _Pragma handling.
109  bool Is_PragmaLexer;
110 
111  //===--------------------------------------------------------------------===//
112  // Context-specific lexing flags set by the preprocessor.
113  //
114 
115  /// ExtendedTokenMode - The lexer can optionally keep comments and whitespace
116  /// and return them as tokens. This is used for -C and -CC modes, and
117  /// whitespace preservation can be useful for some clients that want to lex
118  /// the file in raw mode and get every character from the file.
119  ///
120  /// When this is set to 2 it returns comments and whitespace. When set to 1
121  /// it returns comments, when it is set to 0 it returns normal tokens only.
122  unsigned char ExtendedTokenMode;
123 
124  //===--------------------------------------------------------------------===//
125  // Context that changes as the file is lexed.
126  // NOTE: any state that mutates when in raw mode must have save/restore code
127  // in Lexer::isNextPPTokenLParen.
128 
129  // BufferPtr - Current pointer into the buffer. This is the next character
130  // to be lexed.
131  const char *BufferPtr;
132 
133  // IsAtStartOfLine - True if the next lexed token should get the "start of
134  // line" flag set on it.
135  bool IsAtStartOfLine;
136 
137  bool IsAtPhysicalStartOfLine;
138 
139  bool HasLeadingSpace;
140 
141  bool HasLeadingEmptyMacro;
142 
143  /// True if this is the first time we're lexing the input file.
144  bool IsFirstTimeLexingFile;
145 
146  // NewLinePtr - A pointer to new line character '\n' being lexed. For '\r\n',
147  // it also points to '\n.'
148  const char *NewLinePtr;
149 
150  // CurrentConflictMarkerState - The kind of conflict marker we are handling.
151  ConflictMarkerKind CurrentConflictMarkerState;
152 
153  /// Non-empty if this \p Lexer is \p isDependencyDirectivesLexer().
155 
156  /// If this \p Lexer is \p isDependencyDirectivesLexer(), it represents the
157  /// next token to use from the current dependency directive.
158  unsigned NextDepDirectiveTokenIndex = 0;
159 
160  void InitLexer(const char *BufStart, const char *BufPtr, const char *BufEnd);
161 
162 public:
163  /// Lexer constructor - Create a new lexer object for the specified buffer
164  /// with the specified preprocessor managing the lexing process. This lexer
165  /// assumes that the associated file buffer and Preprocessor objects will
166  /// outlive it, so it doesn't take ownership of either of them.
167  Lexer(FileID FID, const llvm::MemoryBufferRef &InputFile, Preprocessor &PP,
168  bool IsFirstIncludeOfFile = true);
169 
170  /// Lexer constructor - Create a new raw lexer object. This object is only
171  /// suitable for calls to 'LexFromRawLexer'. This lexer assumes that the
172  /// text range will outlive it, so it doesn't take ownership of it.
173  Lexer(SourceLocation FileLoc, const LangOptions &LangOpts,
174  const char *BufStart, const char *BufPtr, const char *BufEnd,
175  bool IsFirstIncludeOfFile = true);
176 
177  /// Lexer constructor - Create a new raw lexer object. This object is only
178  /// suitable for calls to 'LexFromRawLexer'. This lexer assumes that the
179  /// text range will outlive it, so it doesn't take ownership of it.
180  Lexer(FileID FID, const llvm::MemoryBufferRef &FromFile,
181  const SourceManager &SM, const LangOptions &LangOpts,
182  bool IsFirstIncludeOfFile = true);
183 
184  Lexer(const Lexer &) = delete;
185  Lexer &operator=(const Lexer &) = delete;
186 
187  /// Create_PragmaLexer: Lexer constructor - Create a new lexer object for
188  /// _Pragma expansion. This has a variety of magic semantics that this method
189  /// sets up. It returns a new'd Lexer that must be delete'd when done.
190  static Lexer *Create_PragmaLexer(SourceLocation SpellingLoc,
191  SourceLocation ExpansionLocStart,
192  SourceLocation ExpansionLocEnd,
193  unsigned TokLen, Preprocessor &PP);
194 
195  /// getFileLoc - Return the File Location for the file we are lexing out of.
196  /// The physical location encodes the location where the characters come from,
197  /// the virtual location encodes where we should *claim* the characters came
198  /// from. Currently this is only used by _Pragma handling.
199  SourceLocation getFileLoc() const { return FileLoc; }
200 
201 private:
202  /// Lex - Return the next token in the file. If this is the end of file, it
203  /// return the tok::eof token. This implicitly involves the preprocessor.
204  bool Lex(Token &Result);
205 
206  /// Called when the preprocessor is in 'dependency scanning lexing mode'.
207  bool LexDependencyDirectiveToken(Token &Result);
208 
209  /// Called when the preprocessor is in 'dependency scanning lexing mode' and
210  /// is skipping a conditional block.
211  bool LexDependencyDirectiveTokenWhileSkipping(Token &Result);
212 
213  /// True when the preprocessor is in 'dependency scanning lexing mode' and
214  /// created this \p Lexer for lexing a set of dependency directive tokens.
215  bool isDependencyDirectivesLexer() const { return !DepDirectives.empty(); }
216 
217  /// Initializes \p Result with data from \p DDTok and advances \p BufferPtr to
218  /// the position just after the token.
219  /// \returns the buffer pointer at the beginning of the token.
220  const char *convertDependencyDirectiveToken(
221  const dependency_directives_scan::Token &DDTok, Token &Result);
222 
223 public:
224  /// isPragmaLexer - Returns true if this Lexer is being used to lex a pragma.
225  bool isPragmaLexer() const { return Is_PragmaLexer; }
226 
227 private:
228  /// IndirectLex - An indirect call to 'Lex' that can be invoked via
229  /// the PreprocessorLexer interface.
230  void IndirectLex(Token &Result) override { Lex(Result); }
231 
232 public:
233  /// LexFromRawLexer - Lex a token from a designated raw lexer (one with no
234  /// associated preprocessor object. Return true if the 'next character to
235  /// read' pointer points at the end of the lexer buffer, false otherwise.
236  bool LexFromRawLexer(Token &Result) {
237  assert(LexingRawMode && "Not already in raw mode!");
238  Lex(Result);
239  // Note that lexing to the end of the buffer doesn't implicitly delete the
240  // lexer when in raw mode.
241  return BufferPtr == BufferEnd;
242  }
243 
244  /// isKeepWhitespaceMode - Return true if the lexer should return tokens for
245  /// every character in the file, including whitespace and comments. This
246  /// should only be used in raw mode, as the preprocessor is not prepared to
247  /// deal with the excess tokens.
248  bool isKeepWhitespaceMode() const {
249  return ExtendedTokenMode > 1;
250  }
251 
252  /// SetKeepWhitespaceMode - This method lets clients enable or disable
253  /// whitespace retention mode.
254  void SetKeepWhitespaceMode(bool Val) {
255  assert((!Val || LexingRawMode || LangOpts.TraditionalCPP) &&
256  "Can only retain whitespace in raw mode or -traditional-cpp");
257  ExtendedTokenMode = Val ? 2 : 0;
258  }
259 
260  /// inKeepCommentMode - Return true if the lexer should return comments as
261  /// tokens.
262  bool inKeepCommentMode() const {
263  return ExtendedTokenMode > 0;
264  }
265 
266  /// SetCommentRetentionMode - Change the comment retention mode of the lexer
267  /// to the specified mode. This is really only useful when lexing in raw
268  /// mode, because otherwise the lexer needs to manage this.
269  void SetCommentRetentionState(bool Mode) {
270  assert(!isKeepWhitespaceMode() &&
271  "Can't play with comment retention state when retaining whitespace");
272  ExtendedTokenMode = Mode ? 1 : 0;
273  }
274 
275  /// Sets the extended token mode back to its initial value, according to the
276  /// language options and preprocessor. This controls whether the lexer
277  /// produces comment and whitespace tokens.
278  ///
279  /// This requires the lexer to have an associated preprocessor. A standalone
280  /// lexer has nothing to reset to.
281  void resetExtendedTokenMode();
282 
283  /// Gets source code buffer.
284  StringRef getBuffer() const {
285  return StringRef(BufferStart, BufferEnd - BufferStart);
286  }
287 
288  /// ReadToEndOfLine - Read the rest of the current preprocessor line as an
289  /// uninterpreted string. This switches the lexer out of directive mode.
290  void ReadToEndOfLine(SmallVectorImpl<char> *Result = nullptr);
291 
292 
293  /// Diag - Forwarding function for diagnostics. This translate a source
294  /// position in the current buffer into a SourceLocation object for rendering.
295  DiagnosticBuilder Diag(const char *Loc, unsigned DiagID) const;
296 
297  /// getSourceLocation - Return a source location identifier for the specified
298  /// offset in the current file.
299  SourceLocation getSourceLocation(const char *Loc, unsigned TokLen = 1) const;
300 
301  /// getSourceLocation - Return a source location for the next character in
302  /// the current file.
304  return getSourceLocation(BufferPtr);
305  }
306 
307  /// Return the current location in the buffer.
308  const char *getBufferLocation() const { return BufferPtr; }
309 
310  /// Returns the current lexing offset.
312  assert(BufferPtr >= BufferStart && "Invalid buffer state");
313  return BufferPtr - BufferStart;
314  }
315 
316  /// Set the lexer's buffer pointer to \p Offset.
317  void seek(unsigned Offset, bool IsAtStartOfLine);
318 
319  /// Stringify - Convert the specified string into a C string by i) escaping
320  /// '\\' and " characters and ii) replacing newline character(s) with "\\n".
321  /// If Charify is true, this escapes the ' character instead of ".
322  static std::string Stringify(StringRef Str, bool Charify = false);
323 
324  /// Stringify - Convert the specified string into a C string by i) escaping
325  /// '\\' and " characters and ii) replacing newline character(s) with "\\n".
326  static void Stringify(SmallVectorImpl<char> &Str);
327 
328  /// getSpelling - This method is used to get the spelling of a token into a
329  /// preallocated buffer, instead of as an std::string. The caller is required
330  /// to allocate enough space for the token, which is guaranteed to be at least
331  /// Tok.getLength() bytes long. The length of the actual result is returned.
332  ///
333  /// Note that this method may do two possible things: it may either fill in
334  /// the buffer specified with characters, or it may *change the input pointer*
335  /// to point to a constant buffer with the data already in it (avoiding a
336  /// copy). The caller is not allowed to modify the returned buffer pointer
337  /// if an internal buffer is returned.
338  static unsigned getSpelling(const Token &Tok, const char *&Buffer,
339  const SourceManager &SourceMgr,
340  const LangOptions &LangOpts,
341  bool *Invalid = nullptr);
342 
343  /// getSpelling() - Return the 'spelling' of the Tok token. The spelling of a
344  /// token is the characters used to represent the token in the source file
345  /// after trigraph expansion and escaped-newline folding. In particular, this
346  /// wants to get the true, uncanonicalized, spelling of things like digraphs
347  /// UCNs, etc.
348  static std::string getSpelling(const Token &Tok,
349  const SourceManager &SourceMgr,
350  const LangOptions &LangOpts,
351  bool *Invalid = nullptr);
352 
353  /// getSpelling - This method is used to get the spelling of the
354  /// token at the given source location. If, as is usually true, it
355  /// is not necessary to copy any data, then the returned string may
356  /// not point into the provided buffer.
357  ///
358  /// This method lexes at the expansion depth of the given
359  /// location and does not jump to the expansion or spelling
360  /// location.
361  static StringRef getSpelling(SourceLocation loc,
362  SmallVectorImpl<char> &buffer,
363  const SourceManager &SM,
364  const LangOptions &options,
365  bool *invalid = nullptr);
366 
367  /// MeasureTokenLength - Relex the token at the specified location and return
368  /// its length in bytes in the input file. If the token needs cleaning (e.g.
369  /// includes a trigraph or an escaped newline) then this count includes bytes
370  /// that are part of that.
371  static unsigned MeasureTokenLength(SourceLocation Loc,
372  const SourceManager &SM,
373  const LangOptions &LangOpts);
374 
375  /// Relex the token at the specified location.
376  /// \returns true if there was a failure, false on success.
377  static bool getRawToken(SourceLocation Loc, Token &Result,
378  const SourceManager &SM,
379  const LangOptions &LangOpts,
380  bool IgnoreWhiteSpace = false);
381 
382  /// Given a location any where in a source buffer, find the location
383  /// that corresponds to the beginning of the token in which the original
384  /// source location lands.
386  const SourceManager &SM,
387  const LangOptions &LangOpts);
388 
389  /// Get the physical length (including trigraphs and escaped newlines) of the
390  /// first \p Characters characters of the token starting at TokStart.
391  static unsigned getTokenPrefixLength(SourceLocation TokStart,
392  unsigned CharNo,
393  const SourceManager &SM,
394  const LangOptions &LangOpts);
395 
396  /// AdvanceToTokenCharacter - If the current SourceLocation specifies a
397  /// location at the start of a token, return a new location that specifies a
398  /// character within the token. This handles trigraphs and escaped newlines.
400  unsigned Characters,
401  const SourceManager &SM,
402  const LangOptions &LangOpts) {
403  return TokStart.getLocWithOffset(
404  getTokenPrefixLength(TokStart, Characters, SM, LangOpts));
405  }
406 
407  /// Computes the source location just past the end of the
408  /// token at this source location.
409  ///
410  /// This routine can be used to produce a source location that
411  /// points just past the end of the token referenced by \p Loc, and
412  /// is generally used when a diagnostic needs to point just after a
413  /// token where it expected something different that it received. If
414  /// the returned source location would not be meaningful (e.g., if
415  /// it points into a macro), this routine returns an invalid
416  /// source location.
417  ///
418  /// \param Offset an offset from the end of the token, where the source
419  /// location should refer to. The default offset (0) produces a source
420  /// location pointing just past the end of the token; an offset of 1 produces
421  /// a source location pointing to the last character in the token, etc.
423  const SourceManager &SM,
424  const LangOptions &LangOpts);
425 
426  /// Given a token range, produce a corresponding CharSourceRange that
427  /// is not a token range. This allows the source range to be used by
428  /// components that don't have access to the lexer and thus can't find the
429  /// end of the range for themselves.
431  const SourceManager &SM,
432  const LangOptions &LangOpts) {
433  SourceLocation End = getLocForEndOfToken(Range.getEnd(), 0, SM, LangOpts);
434  return End.isInvalid() ? CharSourceRange()
436  Range.getBegin(), End);
437  }
439  const SourceManager &SM,
440  const LangOptions &LangOpts) {
441  return Range.isTokenRange()
442  ? getAsCharRange(Range.getAsRange(), SM, LangOpts)
443  : Range;
444  }
445 
446  /// Returns true if the given MacroID location points at the first
447  /// token of the macro expansion.
448  ///
449  /// \param MacroBegin If non-null and function returns true, it is set to
450  /// begin location of the macro.
452  const SourceManager &SM,
453  const LangOptions &LangOpts,
454  SourceLocation *MacroBegin = nullptr);
455 
456  /// Returns true if the given MacroID location points at the last
457  /// token of the macro expansion.
458  ///
459  /// \param MacroEnd If non-null and function returns true, it is set to
460  /// end location of the macro.
461  static bool isAtEndOfMacroExpansion(SourceLocation loc,
462  const SourceManager &SM,
463  const LangOptions &LangOpts,
464  SourceLocation *MacroEnd = nullptr);
465 
466  /// Accepts a range and returns a character range with file locations.
467  ///
468  /// Returns a null range if a part of the range resides inside a macro
469  /// expansion or the range does not reside on the same FileID.
470  ///
471  /// This function is trying to deal with macros and return a range based on
472  /// file locations. The cases where it can successfully handle macros are:
473  ///
474  /// -begin or end range lies at the start or end of a macro expansion, in
475  /// which case the location will be set to the expansion point, e.g:
476  /// \#define M 1 2
477  /// a M
478  /// If you have a range [a, 2] (where 2 came from the macro), the function
479  /// will return a range for "a M"
480  /// if you have range [a, 1], the function will fail because the range
481  /// overlaps with only a part of the macro
482  ///
483  /// -The macro is a function macro and the range can be mapped to the macro
484  /// arguments, e.g:
485  /// \#define M 1 2
486  /// \#define FM(x) x
487  /// FM(a b M)
488  /// if you have range [b, 2], the function will return the file range "b M"
489  /// inside the macro arguments.
490  /// if you have range [a, 2], the function will return the file range
491  /// "FM(a b M)" since the range includes all of the macro expansion.
493  const SourceManager &SM,
494  const LangOptions &LangOpts);
495 
496  /// Returns a string for the source that the range encompasses.
497  static StringRef getSourceText(CharSourceRange Range,
498  const SourceManager &SM,
499  const LangOptions &LangOpts,
500  bool *Invalid = nullptr);
501 
502  /// Retrieve the name of the immediate macro expansion.
503  ///
504  /// This routine starts from a source location, and finds the name of the macro
505  /// responsible for its immediate expansion. It looks through any intervening
506  /// macro argument expansions to compute this. It returns a StringRef which
507  /// refers to the SourceManager-owned buffer of the source where that macro
508  /// name is spelled. Thus, the result shouldn't out-live that SourceManager.
509  static StringRef getImmediateMacroName(SourceLocation Loc,
510  const SourceManager &SM,
511  const LangOptions &LangOpts);
512 
513  /// Retrieve the name of the immediate macro expansion.
514  ///
515  /// This routine starts from a source location, and finds the name of the
516  /// macro responsible for its immediate expansion. It looks through any
517  /// intervening macro argument expansions to compute this. It returns a
518  /// StringRef which refers to the SourceManager-owned buffer of the source
519  /// where that macro name is spelled. Thus, the result shouldn't out-live
520  /// that SourceManager.
521  ///
522  /// This differs from Lexer::getImmediateMacroName in that any macro argument
523  /// location will result in the topmost function macro that accepted it.
524  /// e.g.
525  /// \code
526  /// MAC1( MAC2(foo) )
527  /// \endcode
528  /// for location of 'foo' token, this function will return "MAC1" while
529  /// Lexer::getImmediateMacroName will return "MAC2".
530  static StringRef getImmediateMacroNameForDiagnostics(
531  SourceLocation Loc, const SourceManager &SM, const LangOptions &LangOpts);
532 
533  /// Compute the preamble of the given file.
534  ///
535  /// The preamble of a file contains the initial comments, include directives,
536  /// and other preprocessor directives that occur before the code in this
537  /// particular file actually begins. The preamble of the main source file is
538  /// a potential prefix header.
539  ///
540  /// \param Buffer The memory buffer containing the file's contents.
541  ///
542  /// \param MaxLines If non-zero, restrict the length of the preamble
543  /// to fewer than this number of lines.
544  ///
545  /// \returns The offset into the file where the preamble ends and the rest
546  /// of the file begins along with a boolean value indicating whether
547  /// the preamble ends at the beginning of a new line.
548  static PreambleBounds ComputePreamble(StringRef Buffer,
549  const LangOptions &LangOpts,
550  unsigned MaxLines = 0);
551 
552  /// Finds the token that comes right after the given location.
553  ///
554  /// Returns the next token, or none if the location is inside a macro.
556  const SourceManager &SM,
557  const LangOptions &LangOpts);
558 
559  /// Checks that the given token is the first token that occurs after
560  /// the given location (this excludes comments and whitespace). Returns the
561  /// location immediately after the specified token. If the token is not found
562  /// or the location is inside a macro, the returned source location will be
563  /// invalid.
565  tok::TokenKind TKind,
566  const SourceManager &SM,
567  const LangOptions &LangOpts,
568  bool SkipTrailingWhitespaceAndNewLine);
569 
570  /// Returns true if the given character could appear in an identifier.
571  static bool isAsciiIdentifierContinueChar(char c,
572  const LangOptions &LangOpts);
573 
574  /// Checks whether new line pointed by Str is preceded by escape
575  /// sequence.
576  static bool isNewLineEscaped(const char *BufferStart, const char *Str);
577 
578  /// getCharAndSizeNoWarn - Like the getCharAndSize method, but does not ever
579  /// emit a warning.
580  static inline char getCharAndSizeNoWarn(const char *Ptr, unsigned &Size,
581  const LangOptions &LangOpts) {
582  // If this is not a trigraph and not a UCN or escaped newline, return
583  // quickly.
584  if (isObviouslySimpleCharacter(Ptr[0])) {
585  Size = 1;
586  return *Ptr;
587  }
588 
589  Size = 0;
590  return getCharAndSizeSlowNoWarn(Ptr, Size, LangOpts);
591  }
592 
593  /// Returns the leading whitespace for line that corresponds to the given
594  /// location \p Loc.
595  static StringRef getIndentationForLine(SourceLocation Loc,
596  const SourceManager &SM);
597 
598  /// Check if this is the first time we're lexing the input file.
599  bool isFirstTimeLexingFile() const { return IsFirstTimeLexingFile; }
600 
601 private:
602  //===--------------------------------------------------------------------===//
603  // Internal implementation interfaces.
604 
605  /// LexTokenInternal - Internal interface to lex a preprocessing token. Called
606  /// by Lex.
607  ///
608  bool LexTokenInternal(Token &Result, bool TokAtPhysicalStartOfLine);
609 
610  bool CheckUnicodeWhitespace(Token &Result, uint32_t C, const char *CurPtr);
611 
612  bool LexUnicodeIdentifierStart(Token &Result, uint32_t C, const char *CurPtr);
613 
614  /// FormTokenWithChars - When we lex a token, we have identified a span
615  /// starting at BufferPtr, going to TokEnd that forms the token. This method
616  /// takes that range and assigns it to the token as its location and size. In
617  /// addition, since tokens cannot overlap, this also updates BufferPtr to be
618  /// TokEnd.
619  void FormTokenWithChars(Token &Result, const char *TokEnd,
621  unsigned TokLen = TokEnd-BufferPtr;
622  Result.setLength(TokLen);
623  Result.setLocation(getSourceLocation(BufferPtr, TokLen));
624  Result.setKind(Kind);
625  BufferPtr = TokEnd;
626  }
627 
628  /// isNextPPTokenLParen - Return 1 if the next unexpanded token will return a
629  /// tok::l_paren token, 0 if it is something else and 2 if there are no more
630  /// tokens in the buffer controlled by this lexer.
631  unsigned isNextPPTokenLParen();
632 
633  //===--------------------------------------------------------------------===//
634  // Lexer character reading interfaces.
635 
636  // This lexer is built on two interfaces for reading characters, both of which
637  // automatically provide phase 1/2 translation. getAndAdvanceChar is used
638  // when we know that we will be reading a character from the input buffer and
639  // that this character will be part of the result token. This occurs in (f.e.)
640  // string processing, because we know we need to read until we find the
641  // closing '"' character.
642  //
643  // The second interface is the combination of getCharAndSize with
644  // ConsumeChar. getCharAndSize reads a phase 1/2 translated character,
645  // returning it and its size. If the lexer decides that this character is
646  // part of the current token, it calls ConsumeChar on it. This two stage
647  // approach allows us to emit diagnostics for characters (e.g. warnings about
648  // trigraphs), knowing that they only are emitted if the character is
649  // consumed.
650 
651  /// isObviouslySimpleCharacter - Return true if the specified character is
652  /// obviously the same in translation phase 1 and translation phase 3. This
653  /// can return false for characters that end up being the same, but it will
654  /// never return true for something that needs to be mapped.
655  static bool isObviouslySimpleCharacter(char C) {
656  return C != '?' && C != '\\';
657  }
658 
659  /// getAndAdvanceChar - Read a single 'character' from the specified buffer,
660  /// advance over it, and return it. This is tricky in several cases. Here we
661  /// just handle the trivial case and fall-back to the non-inlined
662  /// getCharAndSizeSlow method to handle the hard case.
663  inline char getAndAdvanceChar(const char *&Ptr, Token &Tok) {
664  // If this is not a trigraph and not a UCN or escaped newline, return
665  // quickly.
666  if (isObviouslySimpleCharacter(Ptr[0])) return *Ptr++;
667 
668  unsigned Size = 0;
669  char C = getCharAndSizeSlow(Ptr, Size, &Tok);
670  Ptr += Size;
671  return C;
672  }
673 
674  /// ConsumeChar - When a character (identified by getCharAndSize) is consumed
675  /// and added to a given token, check to see if there are diagnostics that
676  /// need to be emitted or flags that need to be set on the token. If so, do
677  /// it.
678  const char *ConsumeChar(const char *Ptr, unsigned Size, Token &Tok) {
679  // Normal case, we consumed exactly one token. Just return it.
680  if (Size == 1)
681  return Ptr+Size;
682 
683  // Otherwise, re-lex the character with a current token, allowing
684  // diagnostics to be emitted and flags to be set.
685  Size = 0;
686  getCharAndSizeSlow(Ptr, Size, &Tok);
687  return Ptr+Size;
688  }
689 
690  /// getCharAndSize - Peek a single 'character' from the specified buffer,
691  /// get its size, and return it. This is tricky in several cases. Here we
692  /// just handle the trivial case and fall-back to the non-inlined
693  /// getCharAndSizeSlow method to handle the hard case.
694  inline char getCharAndSize(const char *Ptr, unsigned &Size) {
695  // If this is not a trigraph and not a UCN or escaped newline, return
696  // quickly.
697  if (isObviouslySimpleCharacter(Ptr[0])) {
698  Size = 1;
699  return *Ptr;
700  }
701 
702  Size = 0;
703  return getCharAndSizeSlow(Ptr, Size);
704  }
705 
706  /// getCharAndSizeSlow - Handle the slow/uncommon case of the getCharAndSize
707  /// method.
708  char getCharAndSizeSlow(const char *Ptr, unsigned &Size,
709  Token *Tok = nullptr);
710 
711  /// getEscapedNewLineSize - Return the size of the specified escaped newline,
712  /// or 0 if it is not an escaped newline. P[-1] is known to be a "\" on entry
713  /// to this function.
714  static unsigned getEscapedNewLineSize(const char *P);
715 
716  /// SkipEscapedNewLines - If P points to an escaped newline (or a series of
717  /// them), skip over them and return the first non-escaped-newline found,
718  /// otherwise return P.
719  static const char *SkipEscapedNewLines(const char *P);
720 
721  /// getCharAndSizeSlowNoWarn - Same as getCharAndSizeSlow, but never emits a
722  /// diagnostic.
723  static char getCharAndSizeSlowNoWarn(const char *Ptr, unsigned &Size,
724  const LangOptions &LangOpts);
725 
726  //===--------------------------------------------------------------------===//
727  // Other lexer functions.
728 
729  void SetByteOffset(unsigned Offset, bool StartOfLine);
730 
731  void PropagateLineStartLeadingSpaceInfo(Token &Result);
732 
733  const char *LexUDSuffix(Token &Result, const char *CurPtr,
734  bool IsStringLiteral);
735 
736  // Helper functions to lex the remainder of a token of the specific type.
737 
738  // This function handles both ASCII and Unicode identifiers after
739  // the first codepoint of the identifyier has been parsed.
740  bool LexIdentifierContinue(Token &Result, const char *CurPtr);
741 
742  bool LexNumericConstant (Token &Result, const char *CurPtr);
743  bool LexStringLiteral (Token &Result, const char *CurPtr,
745  bool LexRawStringLiteral (Token &Result, const char *CurPtr,
747  bool LexAngledStringLiteral(Token &Result, const char *CurPtr);
748  bool LexCharConstant (Token &Result, const char *CurPtr,
750  bool LexEndOfFile (Token &Result, const char *CurPtr);
751  bool SkipWhitespace (Token &Result, const char *CurPtr,
752  bool &TokAtPhysicalStartOfLine);
753  bool SkipLineComment (Token &Result, const char *CurPtr,
754  bool &TokAtPhysicalStartOfLine);
755  bool SkipBlockComment (Token &Result, const char *CurPtr,
756  bool &TokAtPhysicalStartOfLine);
757  bool SaveLineComment (Token &Result, const char *CurPtr);
758 
759  bool IsStartOfConflictMarker(const char *CurPtr);
760  bool HandleEndOfConflictMarker(const char *CurPtr);
761 
762  bool lexEditorPlaceholder(Token &Result, const char *CurPtr);
763 
764  bool isCodeCompletionPoint(const char *CurPtr) const;
765  void cutOffLexing() { BufferPtr = BufferEnd; }
766 
767  bool isHexaLiteral(const char *Start, const LangOptions &LangOpts);
768 
769  void codeCompleteIncludedFile(const char *PathStart,
770  const char *CompletionPoint, bool IsAngled);
771 
772  /// Read a universal character name.
773  ///
774  /// \param StartPtr The position in the source buffer after the initial '\'.
775  /// If the UCN is syntactically well-formed (but not
776  /// necessarily valid), this parameter will be updated to
777  /// point to the character after the UCN.
778  /// \param SlashLoc The position in the source buffer of the '\'.
779  /// \param Result The token being formed. Pass \c nullptr to suppress
780  /// diagnostics and handle token formation in the caller.
781  ///
782  /// \return The Unicode codepoint specified by the UCN, or 0 if the UCN is
783  /// invalid.
784  uint32_t tryReadUCN(const char *&StartPtr, const char *SlashLoc, Token *Result);
785 
786  /// Try to consume a UCN as part of an identifier at the current
787  /// location.
788  /// \param CurPtr Initially points to the range of characters in the source
789  /// buffer containing the '\'. Updated to point past the end of
790  /// the UCN on success.
791  /// \param Size The number of characters occupied by the '\' (including
792  /// trigraphs and escaped newlines).
793  /// \param Result The token being produced. Marked as containing a UCN on
794  /// success.
795  /// \return \c true if a UCN was lexed and it produced an acceptable
796  /// identifier character, \c false otherwise.
797  bool tryConsumeIdentifierUCN(const char *&CurPtr, unsigned Size,
798  Token &Result);
799 
800  /// Try to consume an identifier character encoded in UTF-8.
801  /// \param CurPtr Points to the start of the (potential) UTF-8 code unit
802  /// sequence. On success, updated to point past the end of it.
803  /// \return \c true if a UTF-8 sequence mapping to an acceptable identifier
804  /// character was lexed, \c false otherwise.
805  bool tryConsumeIdentifierUTF8Char(const char *&CurPtr);
806 };
807 
808 } // namespace clang
809 
810 #endif // LLVM_CLANG_LEX_LEXER_H
clang::Lexer::isAtEndOfMacroExpansion
static bool isAtEndOfMacroExpansion(SourceLocation loc, const SourceManager &SM, const LangOptions &LangOpts, SourceLocation *MacroEnd=nullptr)
Returns true if the given MacroID location points at the last token of the macro expansion.
Definition: Lexer.cpp:830
clang::Lexer::makeFileCharRange
static CharSourceRange makeFileCharRange(CharSourceRange Range, const SourceManager &SM, const LangOptions &LangOpts)
Accepts a range and returns a character range with file locations.
Definition: Lexer.cpp:891
PreprocessorLexer.h
llvm
YAML serialization mapping.
Definition: Dominators.h:30
clang::Lexer::SetCommentRetentionState
void SetCommentRetentionState(bool Mode)
SetCommentRetentionMode - Change the comment retention mode of the lexer to the specified mode.
Definition: Lexer.h:269
clang::DiagnosticBuilder
A little helper class used to produce diagnostics.
Definition: Diagnostic.h:1265
clang::CMK_Perforce
@ CMK_Perforce
A Perforce-style conflict marker, initiated by 4 ">"s, separated by 4 "="s, and terminated by 4 "<"s.
Definition: Lexer.h:54
clang::SourceRange
A trivial tuple used to represent a source range.
Definition: SourceLocation.h:210
string
string(SUBSTRING ${CMAKE_CURRENT_BINARY_DIR} 0 ${PATH_LIB_START} PATH_HEAD) string(SUBSTRING $
Definition: CMakeLists.txt:22
clang::Lexer::getRawToken
static bool getRawToken(SourceLocation Loc, Token &Result, const SourceManager &SM, const LangOptions &LangOpts, bool IgnoreWhiteSpace=false)
Relex the token at the specified location.
Definition: Lexer.cpp:461
clang::Lexer::seek
void seek(unsigned Offset, bool IsAtStartOfLine)
Set the lexer's buffer pointer to Offset.
Definition: Lexer.cpp:229
clang::Lexer::isAsciiIdentifierContinueChar
static bool isAsciiIdentifierContinueChar(char c, const LangOptions &LangOpts)
Returns true if the given character could appear in an identifier.
Definition: Lexer.cpp:1068
clang::ConflictMarkerKind
ConflictMarkerKind
ConflictMarkerKind - Kinds of conflict marker which the lexer might be recovering from.
Definition: Lexer.h:44
clang::Lexer::getSpelling
static unsigned getSpelling(const Token &Tok, const char *&Buffer, const SourceManager &SourceMgr, const LangOptions &LangOpts, bool *Invalid=nullptr)
getSpelling - This method is used to get the spelling of a token into a preallocated buffer,...
Definition: Lexer.cpp:403
clang::SourceLocation
Encodes a location in the source.
Definition: SourceLocation.h:86
clang::SourceLocation::getLocWithOffset
SourceLocation getLocWithOffset(IntTy Offset) const
Return a source location with the specified offset from this SourceLocation.
Definition: SourceLocation.h:134
clang::Lexer::getFileLoc
SourceLocation getFileLoc() const
getFileLoc - Return the File Location for the file we are lexing out of.
Definition: Lexer.h:199
clang::Lexer::inKeepCommentMode
bool inKeepCommentMode() const
inKeepCommentMode - Return true if the lexer should return comments as tokens.
Definition: Lexer.h:262
clang::PreprocessorLexer
Definition: PreprocessorLexer.h:30
clang::Lexer::Create_PragmaLexer
static Lexer * Create_PragmaLexer(SourceLocation SpellingLoc, SourceLocation ExpansionLocStart, SourceLocation ExpansionLocEnd, unsigned TokLen, Preprocessor &PP)
Create_PragmaLexer: Lexer constructor - Create a new lexer object for _Pragma expansion.
Definition: Lexer.cpp:194
AttributeLangSupport::C
@ C
Definition: SemaDeclAttr.cpp:55
llvm::Optional
Definition: LLVM.h:40
clang::Lexer::getSourceText
static StringRef getSourceText(CharSourceRange Range, const SourceManager &SM, const LangOptions &LangOpts, bool *Invalid=nullptr)
Returns a string for the source that the range encompasses.
Definition: Lexer.cpp:960
clang::PreprocessorLexer::LexingRawMode
bool LexingRawMode
True if in raw mode.
Definition: PreprocessorLexer.h:68
clang::Lexer::isKeepWhitespaceMode
bool isKeepWhitespaceMode() const
isKeepWhitespaceMode - Return true if the lexer should return tokens for every character in the file,...
Definition: Lexer.h:248
clang::Lexer::MeasureTokenLength
static unsigned MeasureTokenLength(SourceLocation Loc, const SourceManager &SM, const LangOptions &LangOpts)
MeasureTokenLength - Relex the token at the specified location and return its length in bytes in the ...
Definition: Lexer.cpp:450
clang::Lexer::LexFromRawLexer
bool LexFromRawLexer(Token &Result)
LexFromRawLexer - Lex a token from a designated raw lexer (one with no associated preprocessor object...
Definition: Lexer.h:236
clang::Token
Token - This structure provides full information about a lexed token.
Definition: Token.h:34
End
SourceLocation End
Definition: USRLocFinder.cpp:167
clang::SourceManager
This class handles loading and caching of source files into memory.
Definition: SourceManager.h:627
clang::Lexer::Stringify
static std::string Stringify(StringRef Str, bool Charify=false)
Stringify - Convert the specified string into a C string by i) escaping '\' and " characters and ii) ...
Definition: Lexer.cpp:261
clang::Lexer
Lexer - This provides a simple interface that turns a text buffer into a stream of tokens.
Definition: Lexer.h:78
Offset
unsigned Offset
Definition: Format.cpp:2574
TokenKinds.h
clang::CharSourceRange::getCharRange
static CharSourceRange getCharRange(SourceRange R)
Definition: SourceLocation.h:265
clang::CMK_Normal
@ CMK_Normal
A normal or diff3 conflict marker, initiated by at least 7 "<"s, separated by at least 7 "="s or "|"s...
Definition: Lexer.h:50
clang::Lexer::Diag
DiagnosticBuilder Diag(const char *Loc, unsigned DiagID) const
Diag - Forwarding function for diagnostics.
Definition: Lexer.cpp:1166
LangOptions.h
clang::Lexer::isNewLineEscaped
static bool isNewLineEscaped(const char *BufferStart, const char *Str)
Checks whether new line pointed by Str is preceded by escape sequence.
Definition: Lexer.cpp:1072
clang::Lexer::Lexer
Lexer(FileID FID, const llvm::MemoryBufferRef &InputFile, Preprocessor &PP, bool IsFirstIncludeOfFile=true)
Lexer constructor - Create a new lexer object for the specified buffer with the specified preprocesso...
Definition: Lexer.cpp:135
clang::Lexer::getTokenPrefixLength
static unsigned getTokenPrefixLength(SourceLocation TokStart, unsigned CharNo, const SourceManager &SM, const LangOptions &LangOpts)
Get the physical length (including trigraphs and escaped newlines) of the first Characters characters...
Definition: Lexer.cpp:726
clang::Lexer::getIndentationForLine
static StringRef getIndentationForLine(SourceLocation Loc, const SourceManager &SM)
Returns the leading whitespace for line that corresponds to the given location Loc.
Definition: Lexer.cpp:1092
clang::PreambleBounds
Describes the bounds (start, size) of the preamble and a flag required by PreprocessorOptions::Precom...
Definition: Lexer.h:60
clang::PreprocessorLexer::FID
const FileID FID
The SourceManager FileID corresponding to the file being lexed.
Definition: PreprocessorLexer.h:40
clang::PreambleBounds::Size
unsigned Size
Size of the preamble in bytes.
Definition: Lexer.h:62
DependencyDirectivesScanner.h
clang::Lexer::ReadToEndOfLine
void ReadToEndOfLine(SmallVectorImpl< char > *Result=nullptr)
ReadToEndOfLine - Read the rest of the current preprocessor line as an uninterpreted string.
Definition: Lexer.cpp:2802
clang::PreprocessorLexer::PP
Preprocessor * PP
Definition: PreprocessorLexer.h:37
clang::Lexer::findNextToken
static Optional< Token > findNextToken(SourceLocation Loc, const SourceManager &SM, const LangOptions &LangOpts)
Finds the token that comes right after the given location.
Definition: Lexer.cpp:1258
clang::Lexer::getImmediateMacroName
static StringRef getImmediateMacroName(SourceLocation Loc, const SourceManager &SM, const LangOptions &LangOpts)
Retrieve the name of the immediate macro expansion.
Definition: Lexer.cpp:996
clang::Lexer::isFirstTimeLexingFile
bool isFirstTimeLexingFile() const
Check if this is the first time we're lexing the input file.
Definition: Lexer.h:599
SourceLocation.h
clang::tok::TokenKind
TokenKind
Provides a simple uniform namespace for tokens from all C languages.
Definition: TokenKinds.h:25
P
StringRef P
Definition: ASTMatchersInternal.cpp:563
clang::Lexer::getBufferLocation
const char * getBufferLocation() const
Return the current location in the buffer.
Definition: Lexer.h:308
clang::syntax::NodeRole::Size
@ Size
clang::PreambleBounds::PreambleBounds
PreambleBounds(unsigned Size, bool PreambleEndsAtStartOfLine)
Definition: Lexer.h:70
clang::Lexer::operator=
Lexer & operator=(const Lexer &)=delete
clang::Lexer::getCurrentBufferOffset
unsigned getCurrentBufferOffset()
Returns the current lexing offset.
Definition: Lexer.h:311
llvm::ArrayRef
Definition: LLVM.h:34
clang::CharSourceRange
Represents a character-granular source range.
Definition: SourceLocation.h:253
clang::LangOptions
Keeps track of the various options that can be enabled, which controls the dialect of C or C++ that i...
Definition: LangOptions.h:78
clang::Lexer::SetKeepWhitespaceMode
void SetKeepWhitespaceMode(bool Val)
SetKeepWhitespaceMode - This method lets clients enable or disable whitespace retention mode.
Definition: Lexer.h:254
clang::ObjCPropertyAttribute::Kind
Kind
Definition: DeclObjCCommon.h:22
clang::Lexer::getImmediateMacroNameForDiagnostics
static StringRef getImmediateMacroNameForDiagnostics(SourceLocation Loc, const SourceManager &SM, const LangOptions &LangOpts)
Retrieve the name of the immediate macro expansion.
Definition: Lexer.cpp:1043
clang::Lexer::getBuffer
StringRef getBuffer() const
Gets source code buffer.
Definition: Lexer.h:284
clang
Definition: CalledOnceCheck.h:17
clang::Lexer::isAtStartOfMacroExpansion
static bool isAtStartOfMacroExpansion(SourceLocation loc, const SourceManager &SM, const LangOptions &LangOpts, SourceLocation *MacroBegin=nullptr)
Returns true if the given MacroID location points at the first token of the macro expansion.
Definition: Lexer.cpp:808
clang::PreambleBounds::PreambleEndsAtStartOfLine
bool PreambleEndsAtStartOfLine
Whether the preamble ends at the start of a new line.
Definition: Lexer.h:68
clang::Lexer::GetBeginningOfToken
static SourceLocation GetBeginningOfToken(SourceLocation Loc, const SourceManager &SM, const LangOptions &LangOpts)
Given a location any where in a source buffer, find the location that corresponds to the beginning of...
Definition: Lexer.cpp:560
clang::Lexer::isPragmaLexer
bool isPragmaLexer() const
isPragmaLexer - Returns true if this Lexer is being used to lex a pragma.
Definition: Lexer.h:225
clang::FileID
An opaque identifier used by SourceManager which refers to a source file (MemoryBuffer) along with it...
Definition: SourceLocation.h:38
clang::Lexer::resetExtendedTokenMode
void resetExtendedTokenMode()
Sets the extended token mode back to its initial value, according to the language options and preproc...
Definition: Lexer.cpp:171
c
__device__ __2f16 float c
Definition: __clang_hip_libdevice_declares.h:315
clang::Lexer::AdvanceToTokenCharacter
static SourceLocation AdvanceToTokenCharacter(SourceLocation TokStart, unsigned Characters, const SourceManager &SM, const LangOptions &LangOpts)
AdvanceToTokenCharacter - If the current SourceLocation specifies a location at the start of a token,...
Definition: Lexer.h:399
clang::Lexer::getLocForEndOfToken
static SourceLocation getLocForEndOfToken(SourceLocation Loc, unsigned Offset, const SourceManager &SM, const LangOptions &LangOpts)
Computes the source location just past the end of the token at this source location.
Definition: Lexer.cpp:786
clang::Lexer::ComputePreamble
static PreambleBounds ComputePreamble(StringRef Buffer, const LangOptions &LangOpts, unsigned MaxLines=0)
Compute the preamble of the given file.
Definition: Lexer.cpp:588
llvm::SmallVectorImpl< char >
clang::Lexer::findLocationAfterToken
static SourceLocation findLocationAfterToken(SourceLocation loc, tok::TokenKind TKind, const SourceManager &SM, const LangOptions &LangOpts, bool SkipTrailingWhitespaceAndNewLine)
Checks that the given token is the first token that occurs after the given location (this excludes co...
Definition: Lexer.cpp:1291
clang::Lexer::getCharAndSizeNoWarn
static char getCharAndSizeNoWarn(const char *Ptr, unsigned &Size, const LangOptions &LangOpts)
getCharAndSizeNoWarn - Like the getCharAndSize method, but does not ever emit a warning.
Definition: Lexer.h:580
clang::Preprocessor
Engages in a tight little dance with the lexer to efficiently preprocess tokens.
Definition: Preprocessor.h:130
clang::LineComment
@ LineComment
Definition: LangStandard.h:48
SM
#define SM(sm)
Definition: Cuda.cpp:81
clang::Lexer::getSourceLocation
SourceLocation getSourceLocation() override
getSourceLocation - Return a source location for the next character in the current file.
Definition: Lexer.h:303
clang::Lexer::getAsCharRange
static CharSourceRange getAsCharRange(CharSourceRange Range, const SourceManager &SM, const LangOptions &LangOpts)
Definition: Lexer.h:438
Token.h
clang::RISCV::Invalid
@ Invalid
Definition: RISCVVIntrinsicUtils.h:148
clang::CMK_None
@ CMK_None
Not within a conflict marker.
Definition: Lexer.h:46
clang::Lexer::getAsCharRange
static CharSourceRange getAsCharRange(SourceRange Range, const SourceManager &SM, const LangOptions &LangOpts)
Given a token range, produce a corresponding CharSourceRange that is not a token range.
Definition: Lexer.h:430