Coverage Report

Created: 2020-09-22 08:39

/Users/buildslave/jenkins/workspace/coverage/llvm-project/clang/include/clang/Lex/Lexer.h
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//===- Lexer.h - C Language Family Lexer ------------------------*- C++ -*-===//
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//
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// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
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// See https://llvm.org/LICENSE.txt for license information.
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// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
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//
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//===----------------------------------------------------------------------===//
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//
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//  This file defines the Lexer interface.
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//
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//===----------------------------------------------------------------------===//
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#ifndef LLVM_CLANG_LEX_LEXER_H
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#define LLVM_CLANG_LEX_LEXER_H
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#include "clang/Basic/LangOptions.h"
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#include "clang/Basic/SourceLocation.h"
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#include "clang/Basic/TokenKinds.h"
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#include "clang/Lex/PreprocessorLexer.h"
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#include "clang/Lex/Token.h"
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#include "llvm/ADT/Optional.h"
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#include "llvm/ADT/SmallVector.h"
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#include "llvm/ADT/StringRef.h"
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#include <cassert>
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#include <cstdint>
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#include <string>
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namespace llvm {
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class MemoryBuffer;
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} // namespace llvm
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namespace clang {
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class DiagnosticBuilder;
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class Preprocessor;
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class SourceManager;
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/// ConflictMarkerKind - Kinds of conflict marker which the lexer might be
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/// recovering from.
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enum ConflictMarkerKind {
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  /// Not within a conflict marker.
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  CMK_None,
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  /// A normal or diff3 conflict marker, initiated by at least 7 "<"s,
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  /// separated by at least 7 "="s or "|"s, and terminated by at least 7 ">"s.
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  CMK_Normal,
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  /// A Perforce-style conflict marker, initiated by 4 ">"s,
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  /// separated by 4 "="s, and terminated by 4 "<"s.
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  CMK_Perforce
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};
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/// Describes the bounds (start, size) of the preamble and a flag required by
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/// PreprocessorOptions::PrecompiledPreambleBytes.
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/// The preamble includes the BOM, if any.
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struct PreambleBounds {
59
  /// Size of the preamble in bytes.
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  unsigned Size;
61
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  /// Whether the preamble ends at the start of a new line.
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  ///
64
  /// Used to inform the lexer as to whether it's starting at the beginning of
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  /// a line after skipping the preamble.
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  bool PreambleEndsAtStartOfLine;
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68
  PreambleBounds(unsigned Size, bool PreambleEndsAtStartOfLine)
69
1.38k
      : Size(Size), PreambleEndsAtStartOfLine(PreambleEndsAtStartOfLine) {}
70
};
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/// Lexer - This provides a simple interface that turns a text buffer into a
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/// stream of tokens.  This provides no support for file reading or buffering,
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/// or buffering/seeking of tokens, only forward lexing is supported.  It relies
75
/// on the specified Preprocessor object to handle preprocessor directives, etc.
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class Lexer : public PreprocessorLexer {
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  friend class Preprocessor;
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  void anchor() override;
80
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  //===--------------------------------------------------------------------===//
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  // Constant configuration values for this lexer.
83
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  // Start of the buffer.
85
  const char *BufferStart;
86
87
  // End of the buffer.
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  const char *BufferEnd;
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  // Location for start of file.
91
  SourceLocation FileLoc;
92
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  // LangOpts enabled by this language (cache).
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  LangOptions LangOpts;
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  // True if lexer for _Pragma handling.
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  bool Is_PragmaLexer;
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  //===--------------------------------------------------------------------===//
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  // Context-specific lexing flags set by the preprocessor.
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  //
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  /// ExtendedTokenMode - The lexer can optionally keep comments and whitespace
104
  /// and return them as tokens.  This is used for -C and -CC modes, and
105
  /// whitespace preservation can be useful for some clients that want to lex
106
  /// the file in raw mode and get every character from the file.
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  ///
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  /// When this is set to 2 it returns comments and whitespace.  When set to 1
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  /// it returns comments, when it is set to 0 it returns normal tokens only.
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  unsigned char ExtendedTokenMode;
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  //===--------------------------------------------------------------------===//
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  // Context that changes as the file is lexed.
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  // NOTE: any state that mutates when in raw mode must have save/restore code
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  // in Lexer::isNextPPTokenLParen.
116
117
  // BufferPtr - Current pointer into the buffer.  This is the next character
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  // to be lexed.
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  const char *BufferPtr;
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  // IsAtStartOfLine - True if the next lexed token should get the "start of
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  // line" flag set on it.
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  bool IsAtStartOfLine;
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  bool IsAtPhysicalStartOfLine;
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  bool HasLeadingSpace;
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  bool HasLeadingEmptyMacro;
130
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  // NewLinePtr - A pointer to new line character '\n' being lexed. For '\r\n',
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  // it also points to '\n.'
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  const char *NewLinePtr;
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  // CurrentConflictMarkerState - The kind of conflict marker we are handling.
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  ConflictMarkerKind CurrentConflictMarkerState;
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  void InitLexer(const char *BufStart, const char *BufPtr, const char *BufEnd);
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public:
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  /// Lexer constructor - Create a new lexer object for the specified buffer
142
  /// with the specified preprocessor managing the lexing process.  This lexer
143
  /// assumes that the associated file buffer and Preprocessor objects will
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  /// outlive it, so it doesn't take ownership of either of them.
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  Lexer(FileID FID, const llvm::MemoryBuffer *InputFile, Preprocessor &PP);
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  /// Lexer constructor - Create a new raw lexer object.  This object is only
148
  /// suitable for calls to 'LexFromRawLexer'.  This lexer assumes that the
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  /// text range will outlive it, so it doesn't take ownership of it.
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  Lexer(SourceLocation FileLoc, const LangOptions &LangOpts,
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        const char *BufStart, const char *BufPtr, const char *BufEnd);
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  /// Lexer constructor - Create a new raw lexer object.  This object is only
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  /// suitable for calls to 'LexFromRawLexer'.  This lexer assumes that the
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  /// text range will outlive it, so it doesn't take ownership of it.
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  Lexer(FileID FID, const llvm::MemoryBuffer *FromFile,
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        const SourceManager &SM, const LangOptions &LangOpts);
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  Lexer(const Lexer &) = delete;
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  Lexer &operator=(const Lexer &) = delete;
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  /// Create_PragmaLexer: Lexer constructor - Create a new lexer object for
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  /// _Pragma expansion.  This has a variety of magic semantics that this method
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  /// sets up.  It returns a new'd Lexer that must be delete'd when done.
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  static Lexer *Create_PragmaLexer(SourceLocation SpellingLoc,
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                                   SourceLocation ExpansionLocStart,
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                                   SourceLocation ExpansionLocEnd,
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                                   unsigned TokLen, Preprocessor &PP);
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  /// getLangOpts - Return the language features currently enabled.
171
  /// NOTE: this lexer modifies features as a file is parsed!
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24.9M
  const LangOptions &getLangOpts() const { return LangOpts; }
173
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  /// getFileLoc - Return the File Location for the file we are lexing out of.
175
  /// The physical location encodes the location where the characters come from,
176
  /// the virtual location encodes where we should *claim* the characters came
177
  /// from.  Currently this is only used by _Pragma handling.
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2.15M
  SourceLocation getFileLoc() const { return FileLoc; }
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private:
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  /// Lex - Return the next token in the file.  If this is the end of file, it
182
  /// return the tok::eof token.  This implicitly involves the preprocessor.
183
  bool Lex(Token &Result);
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185
public:
186
  /// isPragmaLexer - Returns true if this Lexer is being used to lex a pragma.
187
4.33M
  bool isPragmaLexer() const { return Is_PragmaLexer; }
188
189
private:
190
  /// IndirectLex - An indirect call to 'Lex' that can be invoked via
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  ///  the PreprocessorLexer interface.
192
0
  void IndirectLex(Token &Result) override { Lex(Result); }
193
194
public:
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  /// LexFromRawLexer - Lex a token from a designated raw lexer (one with no
196
  /// associated preprocessor object.  Return true if the 'next character to
197
  /// read' pointer points at the end of the lexer buffer, false otherwise.
198
53.6M
  bool LexFromRawLexer(Token &Result) {
199
53.6M
    assert(LexingRawMode && "Not already in raw mode!");
200
53.6M
    Lex(Result);
201
    // Note that lexing to the end of the buffer doesn't implicitly delete the
202
    // lexer when in raw mode.
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53.6M
    return BufferPtr == BufferEnd;
204
53.6M
  }
205
206
  /// isKeepWhitespaceMode - Return true if the lexer should return tokens for
207
  /// every character in the file, including whitespace and comments.  This
208
  /// should only be used in raw mode, as the preprocessor is not prepared to
209
  /// deal with the excess tokens.
210
1.08G
  bool isKeepWhitespaceMode() const {
211
1.08G
    return ExtendedTokenMode > 1;
212
1.08G
  }
213
214
  /// SetKeepWhitespaceMode - This method lets clients enable or disable
215
  /// whitespace retention mode.
216
138M
  void SetKeepWhitespaceMode(bool Val) {
217
138M
    assert((!Val || LexingRawMode || LangOpts.TraditionalCPP) &&
218
138M
           "Can only retain whitespace in raw mode or -traditional-cpp");
219
138M
    ExtendedTokenMode = Val ? 
251.4k
: 0;
220
138M
  }
221
222
  /// inKeepCommentMode - Return true if the lexer should return comments as
223
  /// tokens.
224
93.0M
  bool inKeepCommentMode() const {
225
93.0M
    return ExtendedTokenMode > 0;
226
93.0M
  }
227
228
  /// SetCommentRetentionMode - Change the comment retention mode of the lexer
229
  /// to the specified mode.  This is really only useful when lexing in raw
230
  /// mode, because otherwise the lexer needs to manage this.
231
264M
  void SetCommentRetentionState(bool Mode) {
232
264M
    assert(!isKeepWhitespaceMode() &&
233
264M
           "Can't play with comment retention state when retaining whitespace");
234
224M
    ExtendedTokenMode = Mode ? 
140.7M
: 0;
235
264M
  }
236
237
  /// Sets the extended token mode back to its initial value, according to the
238
  /// language options and preprocessor. This controls whether the lexer
239
  /// produces comment and whitespace tokens.
240
  ///
241
  /// This requires the lexer to have an associated preprocessor. A standalone
242
  /// lexer has nothing to reset to.
243
  void resetExtendedTokenMode();
244
245
  /// Gets source code buffer.
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5.19k
  StringRef getBuffer() const {
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5.19k
    return StringRef(BufferStart, BufferEnd - BufferStart);
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5.19k
  }
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250
  /// ReadToEndOfLine - Read the rest of the current preprocessor line as an
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  /// uninterpreted string.  This switches the lexer out of directive mode.
252
  void ReadToEndOfLine(SmallVectorImpl<char> *Result = nullptr);
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254
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  /// Diag - Forwarding function for diagnostics.  This translate a source
256
  /// position in the current buffer into a SourceLocation object for rendering.
257
  DiagnosticBuilder Diag(const char *Loc, unsigned DiagID) const;
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259
  /// getSourceLocation - Return a source location identifier for the specified
260
  /// offset in the current file.
261
  SourceLocation getSourceLocation(const char *Loc, unsigned TokLen = 1) const;
262
263
  /// getSourceLocation - Return a source location for the next character in
264
  /// the current file.
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2.31M
  SourceLocation getSourceLocation() override {
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2.31M
    return getSourceLocation(BufferPtr);
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2.31M
  }
268
269
  /// Return the current location in the buffer.
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48.5k
  const char *getBufferLocation() const { return BufferPtr; }
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272
  /// Returns the current lexing offset.
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37.1k
  unsigned getCurrentBufferOffset() {
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37.1k
    assert(BufferPtr >= BufferStart && "Invalid buffer state");
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37.1k
    return BufferPtr - BufferStart;
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37.1k
  }
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  /// Skip over \p NumBytes bytes.
279
  ///
280
  /// If the skip is successful, the next token will be lexed from the new
281
  /// offset. The lexer also assumes that we skipped to the start of the line.
282
  ///
283
  /// \returns true if the skip failed (new offset would have been past the
284
  /// end of the buffer), false otherwise.
285
  bool skipOver(unsigned NumBytes);
286
287
  /// Stringify - Convert the specified string into a C string by i) escaping
288
  /// '\\' and " characters and ii) replacing newline character(s) with "\\n".
289
  /// If Charify is true, this escapes the ' character instead of ".
290
  static std::string Stringify(StringRef Str, bool Charify = false);
291
292
  /// Stringify - Convert the specified string into a C string by i) escaping
293
  /// '\\' and " characters and ii) replacing newline character(s) with "\\n".
294
  static void Stringify(SmallVectorImpl<char> &Str);
295
296
  /// getSpelling - This method is used to get the spelling of a token into a
297
  /// preallocated buffer, instead of as an std::string.  The caller is required
298
  /// to allocate enough space for the token, which is guaranteed to be at least
299
  /// Tok.getLength() bytes long.  The length of the actual result is returned.
300
  ///
301
  /// Note that this method may do two possible things: it may either fill in
302
  /// the buffer specified with characters, or it may *change the input pointer*
303
  /// to point to a constant buffer with the data already in it (avoiding a
304
  /// copy).  The caller is not allowed to modify the returned buffer pointer
305
  /// if an internal buffer is returned.
306
  static unsigned getSpelling(const Token &Tok, const char *&Buffer,
307
                              const SourceManager &SourceMgr,
308
                              const LangOptions &LangOpts,
309
                              bool *Invalid = nullptr);
310
311
  /// getSpelling() - Return the 'spelling' of the Tok token.  The spelling of a
312
  /// token is the characters used to represent the token in the source file
313
  /// after trigraph expansion and escaped-newline folding.  In particular, this
314
  /// wants to get the true, uncanonicalized, spelling of things like digraphs
315
  /// UCNs, etc.
316
  static std::string getSpelling(const Token &Tok,
317
                                 const SourceManager &SourceMgr,
318
                                 const LangOptions &LangOpts,
319
                                 bool *Invalid = nullptr);
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321
  /// getSpelling - This method is used to get the spelling of the
322
  /// token at the given source location.  If, as is usually true, it
323
  /// is not necessary to copy any data, then the returned string may
324
  /// not point into the provided buffer.
325
  ///
326
  /// This method lexes at the expansion depth of the given
327
  /// location and does not jump to the expansion or spelling
328
  /// location.
329
  static StringRef getSpelling(SourceLocation loc,
330
                               SmallVectorImpl<char> &buffer,
331
                               const SourceManager &SM,
332
                               const LangOptions &options,
333
                               bool *invalid = nullptr);
334
335
  /// MeasureTokenLength - Relex the token at the specified location and return
336
  /// its length in bytes in the input file.  If the token needs cleaning (e.g.
337
  /// includes a trigraph or an escaped newline) then this count includes bytes
338
  /// that are part of that.
339
  static unsigned MeasureTokenLength(SourceLocation Loc,
340
                                     const SourceManager &SM,
341
                                     const LangOptions &LangOpts);
342
343
  /// Relex the token at the specified location.
344
  /// \returns true if there was a failure, false on success.
345
  static bool getRawToken(SourceLocation Loc, Token &Result,
346
                          const SourceManager &SM,
347
                          const LangOptions &LangOpts,
348
                          bool IgnoreWhiteSpace = false);
349
350
  /// Given a location any where in a source buffer, find the location
351
  /// that corresponds to the beginning of the token in which the original
352
  /// source location lands.
353
  static SourceLocation GetBeginningOfToken(SourceLocation Loc,
354
                                            const SourceManager &SM,
355
                                            const LangOptions &LangOpts);
356
357
  /// Get the physical length (including trigraphs and escaped newlines) of the
358
  /// first \p Characters characters of the token starting at TokStart.
359
  static unsigned getTokenPrefixLength(SourceLocation TokStart,
360
                                       unsigned CharNo,
361
                                       const SourceManager &SM,
362
                                       const LangOptions &LangOpts);
363
364
  /// AdvanceToTokenCharacter - If the current SourceLocation specifies a
365
  /// location at the start of a token, return a new location that specifies a
366
  /// character within the token.  This handles trigraphs and escaped newlines.
367
  static SourceLocation AdvanceToTokenCharacter(SourceLocation TokStart,
368
                                                unsigned Characters,
369
                                                const SourceManager &SM,
370
57.1k
                                                const LangOptions &LangOpts) {
371
57.1k
    return TokStart.getLocWithOffset(
372
57.1k
        getTokenPrefixLength(TokStart, Characters, SM, LangOpts));
373
57.1k
  }
374
375
  /// Computes the source location just past the end of the
376
  /// token at this source location.
377
  ///
378
  /// This routine can be used to produce a source location that
379
  /// points just past the end of the token referenced by \p Loc, and
380
  /// is generally used when a diagnostic needs to point just after a
381
  /// token where it expected something different that it received. If
382
  /// the returned source location would not be meaningful (e.g., if
383
  /// it points into a macro), this routine returns an invalid
384
  /// source location.
385
  ///
386
  /// \param Offset an offset from the end of the token, where the source
387
  /// location should refer to. The default offset (0) produces a source
388
  /// location pointing just past the end of the token; an offset of 1 produces
389
  /// a source location pointing to the last character in the token, etc.
390
  static SourceLocation getLocForEndOfToken(SourceLocation Loc, unsigned Offset,
391
                                            const SourceManager &SM,
392
                                            const LangOptions &LangOpts);
393
394
  /// Given a token range, produce a corresponding CharSourceRange that
395
  /// is not a token range. This allows the source range to be used by
396
  /// components that don't have access to the lexer and thus can't find the
397
  /// end of the range for themselves.
398
  static CharSourceRange getAsCharRange(SourceRange Range,
399
                                        const SourceManager &SM,
400
6.34k
                                        const LangOptions &LangOpts) {
401
6.34k
    SourceLocation End = getLocForEndOfToken(Range.getEnd(), 0, SM, LangOpts);
402
1
    return End.isInvalid() ? CharSourceRange()
403
6.34k
                           : CharSourceRange::getCharRange(
404
6.34k
                                 Range.getBegin(), End);
405
6.34k
  }
406
  static CharSourceRange getAsCharRange(CharSourceRange Range,
407
                                        const SourceManager &SM,
408
1.99k
                                        const LangOptions &LangOpts) {
409
1.99k
    return Range.isTokenRange()
410
1.95k
               ? getAsCharRange(Range.getAsRange(), SM, LangOpts)
411
41
               : Range;
412
1.99k
  }
413
414
  /// Returns true if the given MacroID location points at the first
415
  /// token of the macro expansion.
416
  ///
417
  /// \param MacroBegin If non-null and function returns true, it is set to
418
  /// begin location of the macro.
419
  static bool isAtStartOfMacroExpansion(SourceLocation loc,
420
                                        const SourceManager &SM,
421
                                        const LangOptions &LangOpts,
422
                                        SourceLocation *MacroBegin = nullptr);
423
424
  /// Returns true if the given MacroID location points at the last
425
  /// token of the macro expansion.
426
  ///
427
  /// \param MacroEnd If non-null and function returns true, it is set to
428
  /// end location of the macro.
429
  static bool isAtEndOfMacroExpansion(SourceLocation loc,
430
                                      const SourceManager &SM,
431
                                      const LangOptions &LangOpts,
432
                                      SourceLocation *MacroEnd = nullptr);
433
434
  /// Accepts a range and returns a character range with file locations.
435
  ///
436
  /// Returns a null range if a part of the range resides inside a macro
437
  /// expansion or the range does not reside on the same FileID.
438
  ///
439
  /// This function is trying to deal with macros and return a range based on
440
  /// file locations. The cases where it can successfully handle macros are:
441
  ///
442
  /// -begin or end range lies at the start or end of a macro expansion, in
443
  ///  which case the location will be set to the expansion point, e.g:
444
  ///    \#define M 1 2
445
  ///    a M
446
  /// If you have a range [a, 2] (where 2 came from the macro), the function
447
  /// will return a range for "a M"
448
  /// if you have range [a, 1], the function will fail because the range
449
  /// overlaps with only a part of the macro
450
  ///
451
  /// -The macro is a function macro and the range can be mapped to the macro
452
  ///  arguments, e.g:
453
  ///    \#define M 1 2
454
  ///    \#define FM(x) x
455
  ///    FM(a b M)
456
  /// if you have range [b, 2], the function will return the file range "b M"
457
  /// inside the macro arguments.
458
  /// if you have range [a, 2], the function will return the file range
459
  /// "FM(a b M)" since the range includes all of the macro expansion.
460
  static CharSourceRange makeFileCharRange(CharSourceRange Range,
461
                                           const SourceManager &SM,
462
                                           const LangOptions &LangOpts);
463
464
  /// Returns a string for the source that the range encompasses.
465
  static StringRef getSourceText(CharSourceRange Range,
466
                                 const SourceManager &SM,
467
                                 const LangOptions &LangOpts,
468
                                 bool *Invalid = nullptr);
469
470
  /// Retrieve the name of the immediate macro expansion.
471
  ///
472
  /// This routine starts from a source location, and finds the name of the macro
473
  /// responsible for its immediate expansion. It looks through any intervening
474
  /// macro argument expansions to compute this. It returns a StringRef which
475
  /// refers to the SourceManager-owned buffer of the source where that macro
476
  /// name is spelled. Thus, the result shouldn't out-live that SourceManager.
477
  static StringRef getImmediateMacroName(SourceLocation Loc,
478
                                         const SourceManager &SM,
479
                                         const LangOptions &LangOpts);
480
481
  /// Retrieve the name of the immediate macro expansion.
482
  ///
483
  /// This routine starts from a source location, and finds the name of the
484
  /// macro responsible for its immediate expansion. It looks through any
485
  /// intervening macro argument expansions to compute this. It returns a
486
  /// StringRef which refers to the SourceManager-owned buffer of the source
487
  /// where that macro name is spelled. Thus, the result shouldn't out-live
488
  /// that SourceManager.
489
  ///
490
  /// This differs from Lexer::getImmediateMacroName in that any macro argument
491
  /// location will result in the topmost function macro that accepted it.
492
  /// e.g.
493
  /// \code
494
  ///   MAC1( MAC2(foo) )
495
  /// \endcode
496
  /// for location of 'foo' token, this function will return "MAC1" while
497
  /// Lexer::getImmediateMacroName will return "MAC2".
498
  static StringRef getImmediateMacroNameForDiagnostics(
499
      SourceLocation Loc, const SourceManager &SM, const LangOptions &LangOpts);
500
501
  /// Compute the preamble of the given file.
502
  ///
503
  /// The preamble of a file contains the initial comments, include directives,
504
  /// and other preprocessor directives that occur before the code in this
505
  /// particular file actually begins. The preamble of the main source file is
506
  /// a potential prefix header.
507
  ///
508
  /// \param Buffer The memory buffer containing the file's contents.
509
  ///
510
  /// \param MaxLines If non-zero, restrict the length of the preamble
511
  /// to fewer than this number of lines.
512
  ///
513
  /// \returns The offset into the file where the preamble ends and the rest
514
  /// of the file begins along with a boolean value indicating whether
515
  /// the preamble ends at the beginning of a new line.
516
  static PreambleBounds ComputePreamble(StringRef Buffer,
517
                                        const LangOptions &LangOpts,
518
                                        unsigned MaxLines = 0);
519
520
  /// Finds the token that comes right after the given location.
521
  ///
522
  /// Returns the next token, or none if the location is inside a macro.
523
  static Optional<Token> findNextToken(SourceLocation Loc,
524
                                       const SourceManager &SM,
525
                                       const LangOptions &LangOpts);
526
527
  /// Checks that the given token is the first token that occurs after
528
  /// the given location (this excludes comments and whitespace). Returns the
529
  /// location immediately after the specified token. If the token is not found
530
  /// or the location is inside a macro, the returned source location will be
531
  /// invalid.
532
  static SourceLocation findLocationAfterToken(SourceLocation loc,
533
                                         tok::TokenKind TKind,
534
                                         const SourceManager &SM,
535
                                         const LangOptions &LangOpts,
536
                                         bool SkipTrailingWhitespaceAndNewLine);
537
538
  /// Returns true if the given character could appear in an identifier.
539
  static bool isIdentifierBodyChar(char c, const LangOptions &LangOpts);
540
541
  /// Checks whether new line pointed by Str is preceded by escape
542
  /// sequence.
543
  static bool isNewLineEscaped(const char *BufferStart, const char *Str);
544
545
  /// getCharAndSizeNoWarn - Like the getCharAndSize method, but does not ever
546
  /// emit a warning.
547
  static inline char getCharAndSizeNoWarn(const char *Ptr, unsigned &Size,
548
258k
                                          const LangOptions &LangOpts) {
549
    // If this is not a trigraph and not a UCN or escaped newline, return
550
    // quickly.
551
258k
    if (isObviouslySimpleCharacter(Ptr[0])) {
552
246k
      Size = 1;
553
246k
      return *Ptr;
554
246k
    }
555
556
12.1k
    Size = 0;
557
12.1k
    return getCharAndSizeSlowNoWarn(Ptr, Size, LangOpts);
558
12.1k
  }
559
560
  /// Returns the leading whitespace for line that corresponds to the given
561
  /// location \p Loc.
562
  static StringRef getIndentationForLine(SourceLocation Loc,
563
                                         const SourceManager &SM);
564
565
private:
566
  //===--------------------------------------------------------------------===//
567
  // Internal implementation interfaces.
568
569
  /// LexTokenInternal - Internal interface to lex a preprocessing token. Called
570
  /// by Lex.
571
  ///
572
  bool LexTokenInternal(Token &Result, bool TokAtPhysicalStartOfLine);
573
574
  bool CheckUnicodeWhitespace(Token &Result, uint32_t C, const char *CurPtr);
575
576
  /// Given that a token begins with the Unicode character \p C, figure out
577
  /// what kind of token it is and dispatch to the appropriate lexing helper
578
  /// function.
579
  bool LexUnicode(Token &Result, uint32_t C, const char *CurPtr);
580
581
  /// FormTokenWithChars - When we lex a token, we have identified a span
582
  /// starting at BufferPtr, going to TokEnd that forms the token.  This method
583
  /// takes that range and assigns it to the token as its location and size.  In
584
  /// addition, since tokens cannot overlap, this also updates BufferPtr to be
585
  /// TokEnd.
586
  void FormTokenWithChars(Token &Result, const char *TokEnd,
587
1.96G
                          tok::TokenKind Kind) {
588
1.96G
    unsigned TokLen = TokEnd-BufferPtr;
589
1.96G
    Result.setLength(TokLen);
590
1.96G
    Result.setLocation(getSourceLocation(BufferPtr, TokLen));
591
1.96G
    Result.setKind(Kind);
592
1.96G
    BufferPtr = TokEnd;
593
1.96G
  }
594
595
  /// isNextPPTokenLParen - Return 1 if the next unexpanded token will return a
596
  /// tok::l_paren token, 0 if it is something else and 2 if there are no more
597
  /// tokens in the buffer controlled by this lexer.
598
  unsigned isNextPPTokenLParen();
599
600
  //===--------------------------------------------------------------------===//
601
  // Lexer character reading interfaces.
602
603
  // This lexer is built on two interfaces for reading characters, both of which
604
  // automatically provide phase 1/2 translation.  getAndAdvanceChar is used
605
  // when we know that we will be reading a character from the input buffer and
606
  // that this character will be part of the result token. This occurs in (f.e.)
607
  // string processing, because we know we need to read until we find the
608
  // closing '"' character.
609
  //
610
  // The second interface is the combination of getCharAndSize with
611
  // ConsumeChar.  getCharAndSize reads a phase 1/2 translated character,
612
  // returning it and its size.  If the lexer decides that this character is
613
  // part of the current token, it calls ConsumeChar on it.  This two stage
614
  // approach allows us to emit diagnostics for characters (e.g. warnings about
615
  // trigraphs), knowing that they only are emitted if the character is
616
  // consumed.
617
618
  /// isObviouslySimpleCharacter - Return true if the specified character is
619
  /// obviously the same in translation phase 1 and translation phase 3.  This
620
  /// can return false for characters that end up being the same, but it will
621
  /// never return true for something that needs to be mapped.
622
3.19G
  static bool isObviouslySimpleCharacter(char C) {
623
3.19G
    return C != '?' && 
C != '\\'3.19G
;
624
3.19G
  }
625
626
  /// getAndAdvanceChar - Read a single 'character' from the specified buffer,
627
  /// advance over it, and return it.  This is tricky in several cases.  Here we
628
  /// just handle the trivial case and fall-back to the non-inlined
629
  /// getCharAndSizeSlow method to handle the hard case.
630
2.48G
  inline char getAndAdvanceChar(const char *&Ptr, Token &Tok) {
631
    // If this is not a trigraph and not a UCN or escaped newline, return
632
    // quickly.
633
2.48G
    if (isObviouslySimpleCharacter(Ptr[0])) 
return *Ptr++2.47G
;
634
635
12.1M
    unsigned Size = 0;
636
12.1M
    char C = getCharAndSizeSlow(Ptr, Size, &Tok);
637
12.1M
    Ptr += Size;
638
12.1M
    return C;
639
12.1M
  }
640
641
  /// ConsumeChar - When a character (identified by getCharAndSize) is consumed
642
  /// and added to a given token, check to see if there are diagnostics that
643
  /// need to be emitted or flags that need to be set on the token.  If so, do
644
  /// it.
645
303M
  const char *ConsumeChar(const char *Ptr, unsigned Size, Token &Tok) {
646
    // Normal case, we consumed exactly one token.  Just return it.
647
303M
    if (Size == 1)
648
303M
      return Ptr+Size;
649
650
    // Otherwise, re-lex the character with a current token, allowing
651
    // diagnostics to be emitted and flags to be set.
652
73
    Size = 0;
653
73
    getCharAndSizeSlow(Ptr, Size, &Tok);
654
73
    return Ptr+Size;
655
73
  }
656
657
  /// getCharAndSize - Peek a single 'character' from the specified buffer,
658
  /// get its size, and return it.  This is tricky in several cases.  Here we
659
  /// just handle the trivial case and fall-back to the non-inlined
660
  /// getCharAndSizeSlow method to handle the hard case.
661
710M
  inline char getCharAndSize(const char *Ptr, unsigned &Size) {
662
    // If this is not a trigraph and not a UCN or escaped newline, return
663
    // quickly.
664
710M
    if (isObviouslySimpleCharacter(Ptr[0])) {
665
710M
      Size = 1;
666
710M
      return *Ptr;
667
710M
    }
668
669
4.59k
    Size = 0;
670
4.59k
    return getCharAndSizeSlow(Ptr, Size);
671
4.59k
  }
672
673
  /// getCharAndSizeSlow - Handle the slow/uncommon case of the getCharAndSize
674
  /// method.
675
  char getCharAndSizeSlow(const char *Ptr, unsigned &Size,
676
                          Token *Tok = nullptr);
677
678
  /// getEscapedNewLineSize - Return the size of the specified escaped newline,
679
  /// or 0 if it is not an escaped newline. P[-1] is known to be a "\" on entry
680
  /// to this function.
681
  static unsigned getEscapedNewLineSize(const char *P);
682
683
  /// SkipEscapedNewLines - If P points to an escaped newline (or a series of
684
  /// them), skip over them and return the first non-escaped-newline found,
685
  /// otherwise return P.
686
  static const char *SkipEscapedNewLines(const char *P);
687
688
  /// getCharAndSizeSlowNoWarn - Same as getCharAndSizeSlow, but never emits a
689
  /// diagnostic.
690
  static char getCharAndSizeSlowNoWarn(const char *Ptr, unsigned &Size,
691
                                       const LangOptions &LangOpts);
692
693
  //===--------------------------------------------------------------------===//
694
  // Other lexer functions.
695
696
  void SetByteOffset(unsigned Offset, bool StartOfLine);
697
698
  void PropagateLineStartLeadingSpaceInfo(Token &Result);
699
700
  const char *LexUDSuffix(Token &Result, const char *CurPtr,
701
                          bool IsStringLiteral);
702
703
  // Helper functions to lex the remainder of a token of the specific type.
704
  bool LexIdentifier         (Token &Result, const char *CurPtr);
705
  bool LexNumericConstant    (Token &Result, const char *CurPtr);
706
  bool LexStringLiteral      (Token &Result, const char *CurPtr,
707
                              tok::TokenKind Kind);
708
  bool LexRawStringLiteral   (Token &Result, const char *CurPtr,
709
                              tok::TokenKind Kind);
710
  bool LexAngledStringLiteral(Token &Result, const char *CurPtr);
711
  bool LexCharConstant       (Token &Result, const char *CurPtr,
712
                              tok::TokenKind Kind);
713
  bool LexEndOfFile          (Token &Result, const char *CurPtr);
714
  bool SkipWhitespace        (Token &Result, const char *CurPtr,
715
                              bool &TokAtPhysicalStartOfLine);
716
  bool SkipLineComment       (Token &Result, const char *CurPtr,
717
                              bool &TokAtPhysicalStartOfLine);
718
  bool SkipBlockComment      (Token &Result, const char *CurPtr,
719
                              bool &TokAtPhysicalStartOfLine);
720
  bool SaveLineComment       (Token &Result, const char *CurPtr);
721
722
  bool IsStartOfConflictMarker(const char *CurPtr);
723
  bool HandleEndOfConflictMarker(const char *CurPtr);
724
725
  bool lexEditorPlaceholder(Token &Result, const char *CurPtr);
726
727
  bool isCodeCompletionPoint(const char *CurPtr) const;
728
63
  void cutOffLexing() { BufferPtr = BufferEnd; }
729
730
  bool isHexaLiteral(const char *Start, const LangOptions &LangOpts);
731
732
  void codeCompleteIncludedFile(const char *PathStart,
733
                                const char *CompletionPoint, bool IsAngled);
734
735
  /// Read a universal character name.
736
  ///
737
  /// \param StartPtr The position in the source buffer after the initial '\'.
738
  ///                 If the UCN is syntactically well-formed (but not 
739
  ///                 necessarily valid), this parameter will be updated to
740
  ///                 point to the character after the UCN.
741
  /// \param SlashLoc The position in the source buffer of the '\'.
742
  /// \param Result   The token being formed. Pass \c nullptr to suppress
743
  ///                 diagnostics and handle token formation in the caller.
744
  ///
745
  /// \return The Unicode codepoint specified by the UCN, or 0 if the UCN is
746
  ///         invalid.
747
  uint32_t tryReadUCN(const char *&StartPtr, const char *SlashLoc, Token *Result);
748
749
  /// Try to consume a UCN as part of an identifier at the current
750
  /// location.
751
  /// \param CurPtr Initially points to the range of characters in the source
752
  ///               buffer containing the '\'. Updated to point past the end of
753
  ///               the UCN on success.
754
  /// \param Size The number of characters occupied by the '\' (including
755
  ///             trigraphs and escaped newlines).
756
  /// \param Result The token being produced. Marked as containing a UCN on
757
  ///               success.
758
  /// \return \c true if a UCN was lexed and it produced an acceptable
759
  ///         identifier character, \c false otherwise.
760
  bool tryConsumeIdentifierUCN(const char *&CurPtr, unsigned Size,
761
                               Token &Result);
762
763
  /// Try to consume an identifier character encoded in UTF-8.
764
  /// \param CurPtr Points to the start of the (potential) UTF-8 code unit
765
  ///        sequence. On success, updated to point past the end of it.
766
  /// \return \c true if a UTF-8 sequence mapping to an acceptable identifier
767
  ///         character was lexed, \c false otherwise.
768
  bool tryConsumeIdentifierUTF8Char(const char *&CurPtr);
769
};
770
771
} // namespace clang
772
773
#endif // LLVM_CLANG_LEX_LEXER_H