1//===--- PTHLexer.h - Lexer based on Pre-tokenized input --------*- C++ -*-===//
2//
3//                     The LLVM Compiler Infrastructure
4//
5// This file is distributed under the University of Illinois Open Source
6// License. See LICENSE.TXT for details.
7//
8//===----------------------------------------------------------------------===//
9//
10// This file defines the PTHLexer interface.
11//
12//===----------------------------------------------------------------------===//
13
14#ifndef LLVM_CLANG_LEX_PTHLEXER_H
15#define LLVM_CLANG_LEX_PTHLEXER_H
16
17#include "clang/Lex/PreprocessorLexer.h"
18
19namespace clang {
20
21class PTHManager;
22class PTHSpellingSearch;
23
24class PTHLexer : public PreprocessorLexer {
25  SourceLocation FileStartLoc;
26
27  /// TokBuf - Buffer from PTH file containing raw token data.
28  const unsigned char* TokBuf;
29
30  /// CurPtr - Pointer into current offset of the token buffer where
31  ///  the next token will be read.
32  const unsigned char* CurPtr;
33
34  /// LastHashTokPtr - Pointer into TokBuf of the last processed '#'
35  ///  token that appears at the start of a line.
36  const unsigned char* LastHashTokPtr;
37
38  /// PPCond - Pointer to a side table in the PTH file that provides a
39  ///  a consise summary of the preproccessor conditional block structure.
40  ///  This is used to perform quick skipping of conditional blocks.
41  const unsigned char* PPCond;
42
43  /// CurPPCondPtr - Pointer inside PPCond that refers to the next entry
44  ///  to process when doing quick skipping of preprocessor blocks.
45  const unsigned char* CurPPCondPtr;
46
47  PTHLexer(const PTHLexer &) = delete;
48  void operator=(const PTHLexer &) = delete;
49
50  /// ReadToken - Used by PTHLexer to read tokens TokBuf.
51  void ReadToken(Token& T);
52
53  bool LexEndOfFile(Token &Result);
54
55  /// PTHMgr - The PTHManager object that created this PTHLexer.
56  PTHManager& PTHMgr;
57
58  Token EofToken;
59
60protected:
61  friend class PTHManager;
62
63  /// Create a PTHLexer for the specified token stream.
64  PTHLexer(Preprocessor& pp, FileID FID, const unsigned char *D,
65           const unsigned char* ppcond, PTHManager &PM);
66public:
67  ~PTHLexer() override {}
68
69  /// Lex - Return the next token.
70  bool Lex(Token &Tok);
71
72  void getEOF(Token &Tok);
73
74  /// DiscardToEndOfLine - Read the rest of the current preprocessor line as an
75  /// uninterpreted string.  This switches the lexer out of directive mode.
76  void DiscardToEndOfLine();
77
78  /// isNextPPTokenLParen - Return 1 if the next unexpanded token will return a
79  /// tok::l_paren token, 0 if it is something else and 2 if there are no more
80  /// tokens controlled by this lexer.
81  unsigned isNextPPTokenLParen() {
82    // isNextPPTokenLParen is not on the hot path, and all we care about is
83    // whether or not we are at a token with kind tok::eof or tok::l_paren.
84    // Just read the first byte from the current token pointer to determine
85    // its kind.
86    tok::TokenKind x = (tok::TokenKind)*CurPtr;
87    return x == tok::eof ? 2 : x == tok::l_paren;
88  }
89
90  /// IndirectLex - An indirect call to 'Lex' that can be invoked via
91  ///  the PreprocessorLexer interface.
92  void IndirectLex(Token &Result) override { Lex(Result); }
93
94  /// getSourceLocation - Return a source location for the token in
95  /// the current file.
96  SourceLocation getSourceLocation() override;
97
98  /// SkipBlock - Used by Preprocessor to skip the current conditional block.
99  bool SkipBlock();
100};
101
102}  // end namespace clang
103
104#endif
105