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 
19 namespace clang {
20 
21 class PTHManager;
22 class PTHSpellingSearch;
23 
24 class 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 
60 protected:
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);
66 public:
~PTHLexer()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.
isNextPPTokenLParen()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.
IndirectLex(Token & Result)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