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 110
