scanner.cpp

来自「开放源码的编译器open watcom 1.6.0版的源代码」· C++ 代码 · 共 475 行

/****************************************************************************
*
*                            Open Watcom Project
*
*    Portions Copyright (c) 1983-2002 Sybase, Inc. All Rights Reserved.
*
*  ========================================================================
*
*    This file contains Original Code and/or Modifications of Original
*    Code as defined in and that are subject to the Sybase Open Watcom
*    Public License version 1.0 (the 'License'). You may not use this file
*    except in compliance with the License. BY USING THIS FILE YOU AGREE TO
*    ALL TERMS AND CONDITIONS OF THE LICENSE. A copy of the License is
*    provided with the Original Code and Modifications, and is also
*    available at www.sybase.com/developer/opensource.
*
*    The Original Code and all software distributed under the License are
*    distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
*    EXPRESS OR IMPLIED, AND SYBASE AND ALL CONTRIBUTORS HEREBY DISCLAIM
*    ALL SUCH WARRANTIES, INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF
*    MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR
*    NON-INFRINGEMENT. Please see the License for the specific language
*    governing rights and limitations under the License.
*
*  ========================================================================
*
* Description:  WHEN YOU FIGURE OUT WHAT THIS FILE DOES, PLEASE
*               DESCRIBE IT HERE!
*
****************************************************************************/


#include <stdlib.h>
#include <string.h>
#include <iostream.h>
#include <unistd.h>
#include "scanner.h"
#include "parser.h"
#include "ytab.h"

#ifdef __WATCOM_CPLUSPLUS__
    #pragma warning 17 10
#endif

extern YYSTYPE yylval;

#define BSIZE   8192

#define YYCTYPE         uchar
#define YYCURSOR        cursor
#define YYLIMIT         lim
#define YYMARKER        ptr
#define YYFILL(n)       {cursor = fill(cursor);}

#define RETURN(i)       {cur = cursor; return i;}


Scanner::Scanner(int i) : in(i),
        bot(NULL), tok(NULL), ptr(NULL), cur(NULL), pos(NULL), lim(NULL),
        top(NULL), eof(NULL), tchar(0), tline(0), cline(1) {
    ;
}

uchar *Scanner::fill(uchar *cursor){
    if(!eof){
        uint cnt = tok - bot;
        if(cnt){
            memcpy(bot, tok, lim - tok);
            tok = bot;
            ptr -= cnt;
            cursor -= cnt;
            pos -= cnt;
            lim -= cnt;
        }
        if((top - lim) < BSIZE){
            uchar *buf = new uchar[(lim - bot) + BSIZE];
            memcpy(buf, tok, lim - tok);
            tok = buf;
            ptr = &buf[ptr - bot];
            cursor = &buf[cursor - bot];
            pos = &buf[pos - bot];
            lim = &buf[lim - bot];
            top = &lim[BSIZE];
            delete bot;
            bot = buf;
        }
        if((cnt = read(in, (char*) lim, BSIZE)) != BSIZE){
            eof = &lim[cnt]; *eof++ = '\n';
        }
        lim += cnt;
    }
    return cursor;
}



int Scanner::echo(ostream &out){
    uchar *cursor = cur;
    tok = cursor;
echo:
{
        YYCTYPE yych;
        unsigned int yyaccept;
        goto yy0;
yy1:    ++YYCURSOR;
yy0:
        if((YYLIMIT - YYCURSOR) < 7) YYFILL(7);
        yych = *YYCURSOR;
        if(yych == '\n')        goto yy4;
        if(yych != '/') goto yy6;
yy2:    yyaccept = 0;
        yych = *(YYMARKER = ++YYCURSOR);
        if(yych == '*') goto yy7;
yy3:
        { goto echo; }
yy4:    yych = *++YYCURSOR;
yy5:
        { if(cursor == eof) RETURN(0);
                                  out.write((char *)tok, cursor - tok);
                                  tok = pos = cursor; cline++;
                                  goto echo; }
yy6:    yych = *++YYCURSOR;
        goto yy3;
yy7:    yych = *++YYCURSOR;
        if(yych == '!') goto yy9;
yy8:    YYCURSOR = YYMARKER;
        switch(yyaccept){
        case 0: goto yy3;
        }
yy9:    yych = *++YYCURSOR;
        if(yych != 'r') goto yy8;
yy10:   yych = *++YYCURSOR;
        if(yych != 'e') goto yy8;
yy11:   yych = *++YYCURSOR;
        if(yych != '2') goto yy8;
yy12:   yych = *++YYCURSOR;
        if(yych != 'c') goto yy8;
yy13:   yych = *++YYCURSOR;
yy14:
        { out.write((char *)tok, &cursor[-7] - tok);
                                  tok = cursor;
                                  RETURN(1); }
}

}


int Scanner::scan(){
    uchar *cursor = cur;
    uint depth;

scan:
    tchar = cursor - pos;
    tline = cline;
    tok = cursor;
{
        YYCTYPE yych;
        unsigned int yyaccept;
        goto yy15;
yy16:   ++YYCURSOR;
yy15:
        if((YYLIMIT - YYCURSOR) < 2) YYFILL(2);
        yych = *YYCURSOR;
        if(yych <= ':'){
                if(yych <= '"'){
                        if(yych <= '\n'){
                                if(yych <= '\b')        goto yy35;
                                if(yych <= '\t')        goto yy31;
                                goto yy33;
                        } else {
                                if(yych == ' ') goto yy31;
                                if(yych <= '!') goto yy35;
                                goto yy23;
                        }
                } else {
                        if(yych <= '*'){
                                if(yych <= '\'')        goto yy35;
                                if(yych <= ')') goto yy27;
                                goto yy21;
                        } else {
                                if(yych <= '+') goto yy28;
                                if(yych == '/') goto yy19;
                                goto yy35;
                        }
                }
        } else {
                if(yych <= 'Z'){
                        if(yych <= '='){
                                if(yych == '<') goto yy35;
                                goto yy27;
                        } else {
                                if(yych == '?') goto yy28;
                                if(yych <= '@') goto yy35;
                                goto yy29;
                        }
                } else {
                        if(yych <= '`'){
                                if(yych <= '[') goto yy25;
                                if(yych <= '\\')        goto yy27;
                                goto yy35;
                        } else {
                                if(yych <= 'z') goto yy29;
                                if(yych <= '{') goto yy17;
                                if(yych <= '|') goto yy27;
                                goto yy35;
                        }
                }
        }
yy17:   yych = *++YYCURSOR;
yy18:
        { depth = 1;
                                  goto code;
                                }
yy19:   yych = *++YYCURSOR;
        if(yych == '*') goto yy54;
yy20:
        { RETURN(*tok); }
yy21:   yych = *++YYCURSOR;
        if(yych == '/') goto yy52;
yy22:
        { yylval.op = *tok;
                                  RETURN(CLOSE); }
yy23:   yyaccept = 0;
        yych = *(YYMARKER = ++YYCURSOR);
        if(yych != '\n')        goto yy48;
yy24:
        { fatal("bad string"); }
yy25:   yyaccept = 1;
        yych = *(YYMARKER = ++YYCURSOR);
        if(yych != '\n')        goto yy42;
yy26:
        { fatal("bad character constant"); }
yy27:   yych = *++YYCURSOR;
        goto yy20;
yy28:   yych = *++YYCURSOR;
        goto yy22;
yy29:   yych = *++YYCURSOR;
        goto yy40;
yy30:
        { cur = cursor;
                                  yylval.symbol = Symbol::find(token());
                                  return ID; }
yy31:   yych = *++YYCURSOR;
        goto yy38;
yy32:
        { goto scan; }
yy33:   yych = *++YYCURSOR;
yy34:
        { if(cursor == eof) RETURN(0);
                                  pos = cursor; cline++;
                                  goto scan;
                                }
yy35:   yych = *++YYCURSOR;
yy36:
        { cerr << "unexpected character: " << *tok << endl;
                                  goto scan;
                                }
yy37:   ++YYCURSOR;
        if(YYLIMIT == YYCURSOR) YYFILL(1);
        yych = *YYCURSOR;
yy38:   if(yych == '\t')        goto yy37;
        if(yych == ' ') goto yy37;
        goto yy32;
yy39:   ++YYCURSOR;
        if(YYLIMIT == YYCURSOR) YYFILL(1);
        yych = *YYCURSOR;
yy40:   if(yych <= '@'){
                if(yych <= '/') goto yy30;
                if(yych <= '9') goto yy39;
                goto yy30;
        } else {
                if(yych <= 'Z') goto yy39;
                if(yych <= '`') goto yy30;
                if(yych <= 'z') goto yy39;
                goto yy30;
        }
yy41:   ++YYCURSOR;
        if(YYLIMIT == YYCURSOR) YYFILL(1);
        yych = *YYCURSOR;
yy42:   if(yych <= '['){
                if(yych != '\n')        goto yy41;
        } else {
                if(yych <= '\\')        goto yy44;
                if(yych <= ']') goto yy45;
                goto yy41;
        }
yy43:   YYCURSOR = YYMARKER;
        switch(yyaccept){
        case 0: goto yy24;
        case 1: goto yy26;
        }
yy44:   ++YYCURSOR;
        if(YYLIMIT == YYCURSOR) YYFILL(1);
        yych = *YYCURSOR;
        if(yych == '\n')        goto yy43;
        goto yy41;
yy45:   yych = *++YYCURSOR;
yy46:
        { cur = cursor;
                                  yylval.regexp = ranToRE(token());
                                  return RANGE; }
yy47:   ++YYCURSOR;
        if(YYLIMIT == YYCURSOR) YYFILL(1);
        yych = *YYCURSOR;
yy48:   if(yych <= '!'){
                if(yych == '\n')        goto yy43;
                goto yy47;
        } else {
                if(yych <= '"') goto yy50;
                if(yych != '\\')        goto yy47;
        }
yy49:   ++YYCURSOR;
        if(YYLIMIT == YYCURSOR) YYFILL(1);
        yych = *YYCURSOR;
        if(yych == '\n')        goto yy43;
        goto yy47;
yy50:   yych = *++YYCURSOR;
yy51:
        { cur = cursor;
                                  yylval.regexp = strToRE(token());
                                  return STRING; }
yy52:   yych = *++YYCURSOR;
yy53:
        { tok = cursor;
                                  RETURN(0); }
yy54:   yych = *++YYCURSOR;
yy55:
        { depth = 1;
                                  goto comment; }
}


code:
{
        YYCTYPE yych;
        unsigned int yyaccept;
        goto yy56;
yy57:   ++YYCURSOR;
yy56:
        if((YYLIMIT - YYCURSOR) < 2) YYFILL(2);
        yych = *YYCURSOR;
        if(yych <= '&'){
                if(yych <= '\n'){
                        if(yych <= '\t')        goto yy64;
                        goto yy62;
                } else {
                        if(yych == '"') goto yy66;
                        goto yy64;
                }
        } else {
                if(yych <= '{'){
                        if(yych <= '\'')        goto yy67;
                        if(yych <= 'z') goto yy64;
                        goto yy60;
                } else {
                        if(yych != '}') goto yy64;
                }
        }
yy58:   yych = *++YYCURSOR;
yy59:
        { if(--depth == 0){
                                        cur = cursor;
                                        yylval.token = new Token(token(), tline);
                                        return CODE;
                                  }
                                  goto code; }
yy60:   yych = *++YYCURSOR;
yy61:
        { ++depth;
                                  goto code; }
yy62:   yych = *++YYCURSOR;
yy63:
        { if(cursor == eof) fatal("missing '}'");
                                  pos = cursor; cline++;
                                  goto code;
                                }
yy64:   yych = *++YYCURSOR;
yy65:
        { goto code; }
yy66:   yyaccept = 0;
        yych = *(YYMARKER = ++YYCURSOR);
        if(yych == '\n')        goto yy65;
        goto yy73;
yy67:   yyaccept = 0;
        yych = *(YYMARKER = ++YYCURSOR);
        if(yych == '\n')        goto yy65;
        goto yy69;
yy68:   ++YYCURSOR;
        if(YYLIMIT == YYCURSOR) YYFILL(1);
        yych = *YYCURSOR;
yy69:   if(yych <= '&'){
                if(yych != '\n')        goto yy68;
        } else {
                if(yych <= '\'')        goto yy64;
                if(yych == '\\')        goto yy71;
                goto yy68;
        }
yy70:   YYCURSOR = YYMARKER;
        switch(yyaccept){
        case 0: goto yy65;
        }
yy71:   ++YYCURSOR;
        if(YYLIMIT == YYCURSOR) YYFILL(1);
        yych = *YYCURSOR;
        if(yych == '\n')        goto yy70;
        goto yy68;
yy72:   ++YYCURSOR;
        if(YYLIMIT == YYCURSOR) YYFILL(1);
        yych = *YYCURSOR;
yy73:   if(yych <= '!'){
                if(yych == '\n')        goto yy70;
                goto yy72;
        } else {
                if(yych <= '"') goto yy64;
                if(yych != '\\')        goto yy72;
        }
yy74:   ++YYCURSOR;
        if(YYLIMIT == YYCURSOR) YYFILL(1);
        yych = *YYCURSOR;
        if(yych == '\n')        goto yy70;
        goto yy72;
}


comment:
{
        YYCTYPE yych;
        goto yy75;
yy76:   ++YYCURSOR;
yy75:
        if((YYLIMIT - YYCURSOR) < 2) YYFILL(2);
        yych = *YYCURSOR;
        if(yych <= ')'){
                if(yych == '\n')        goto yy80;
                goto yy82;
        } else {
                if(yych <= '*') goto yy77;
                if(yych == '/') goto yy79;
                goto yy82;
        }
yy77:   yych = *++YYCURSOR;
        if(yych == '/') goto yy85;
yy78:
        { goto comment; }
yy79:   yych = *++YYCURSOR;
        if(yych == '*') goto yy83;
        goto yy78;
yy80:   yych = *++YYCURSOR;
yy81:
        { if(cursor == eof) RETURN(0);
                                  tok = pos = cursor; cline++;
                                  goto comment;
                                }
yy82:   yych = *++YYCURSOR;
        goto yy78;
yy83:   yych = *++YYCURSOR;
yy84:
        { ++depth;
                                  goto comment; }
yy85:   yych = *++YYCURSOR;
yy86:
        { if(--depth == 0)
                                        goto scan;
                                    else
                                        goto comment; }
}

}

void Scanner::fatal(char *msg){
    cerr << "line " << tline << ", column " << (tchar + 1) << ": "
        << msg << endl;
    exit(1);
}