Tools/CCode/Source/Pccts/h/ATokenBuffer.h

   1 /* ANTLRTokenBuffer.h
   2  *
   3  * SOFTWARE RIGHTS
   4  *
   5  * We reserve no LEGAL rights to the Purdue Compiler Construction Tool
   6  * Set (PCCTS) -- PCCTS is in the public domain.  An individual or
   7  * company may do whatever they wish with source code distributed with
   8  * PCCTS or the code generated by PCCTS, including the incorporation of
   9  * PCCTS, or its output, into commerical software.
  10  *
  11  * We encourage users to develop software with PCCTS.  However, we do ask
  12  * that credit is given to us for developing PCCTS.  By "credit",
  13  * we mean that if you incorporate our source code into one of your
  14  * programs (commercial product, research project, or otherwise) that you
  15  * acknowledge this fact somewhere in the documentation, research report,
  16  * etc...  If you like PCCTS and have developed a nice tool with the
  17  * output, please mention that you developed it using PCCTS.  In
  18  * addition, we ask that this header remain intact in our source code.
  19  * As long as these guidelines are kept, we expect to continue enhancing
  20  * this system and expect to make other tools available as they are
  21  * completed.
  22  *
  23  * ANTLR 1.33
  24  * Terence Parr
  25  * Parr Research Corporation
  26  * with Purdue University and AHPCRC, University of Minnesota
  27  * 1989-2000
  28  */
  29
  30 #ifndef ATOKENBUFFER_H_GATE
  31 #define ATOKENBUFFER_H_GATE
  32
  33 #include "pcctscfg.h"
  34
  35 #include "pccts_stdlib.h"
  36
  37 PCCTS_NAMESPACE_STD
  38
  39 #include ATOKEN_H
  40 #include ATOKENSTREAM_H
  41
  42 /*
  43  * The parser is "attached" to an ANTLRTokenBuffer via interface
  44  * functions: getToken() and bufferedToken().  The object that actually
  45  * consumes characters and constructs tokens is connected to the
  46  * ANTLRTokenBuffer via interface function ANTLRTokenStream::getToken();
  47  * where ANTLRTokenStream is really just a behavior (class with no data).
  48  * C++ does not have this abstraction and hence we simply have come up
  49  * with a fancy name for "void *".  See the note in ANTLRTokenStream.h on
  50  * the "behavior" of ANTLRTokenStream.
  51  */
  52
  53 class ANTLRParser;                                      // MR1
  54
  55 class DllExportPCCTS ANTLRTokenBuffer {
  56 protected:
  57         ANTLRTokenStream *input;        // where do I get tokens
  58         int buffer_size;
  59         int chunk_size;
  60         int num_markers;
  61         int k;                          // Need at least this many tokens in buffer
  62         _ANTLRTokenPtr *buffer; // buffer used for arbitrary lookahead
  63         _ANTLRTokenPtr *tp;        // pts into buffer; current token ptr
  64         _ANTLRTokenPtr *last;      // pts to last valid token in buffer
  65         _ANTLRTokenPtr *next;      // place to put token from getANTLRToken()
  66         _ANTLRTokenPtr *end_of_buffer;
  67         /* when you try to write a token past this and there are no markers
  68            set, then move k-1 tokens back to the beginning of the buffer.
  69            We want to stay away from the end of the buffer because we have
  70            to extend it if a marker is set and we reach the end (we cannot
  71            move tokens to the beginning of the buffer in this case).
  72          */
  73         _ANTLRTokenPtr *threshold;
  74         unsigned char _deleteTokens;
  75
  76         // This function is filled in by the subclass; it initiates fetch of input
  77         virtual _ANTLRTokenPtr getANTLRToken() { return input->getToken(); }
  78         void makeRoom();
  79         void extendBuffer();
  80
  81 public:
  82         ANTLRTokenBuffer(ANTLRTokenStream *in, int k=1, int chksz=50);
  83         virtual ~ANTLRTokenBuffer();
  84         virtual _ANTLRTokenPtr getToken();
  85         virtual void rewind(int pos);
  86         virtual int mark();
  87         virtual _ANTLRTokenPtr bufferedToken(int i);
  88
  89         void noGarbageCollectTokens()   { _deleteTokens=0; }
  90         void garbageCollectTokens()             { _deleteTokens=1; }
  91
  92         virtual int bufferSize() { return buffer_size; }
  93         virtual int minTokens() { return k; }
  94         virtual void setMinTokens(int k_new) { k = k_new; }
  95
  96         virtual void panic(const char *msg); /* MR20 const */
  97
  98         virtual int printMessage(FILE* pFile, const char* pFormat, ...); // MR23
  99
 100 protected:                                              // MR1
 101         ANTLRParser     *parser;                        // MR1
 102 public:                                                 // MR1
 103         ANTLRParser     *setParser(ANTLRParser *p);     // MR1
 104         ANTLRParser     *getParser();                       // MR1
 105     ANTLRTokenStream *getLexer() const {    // MR12
 106       return input;}                        // MR12
 107 };
 108
 109 #endif