155 lines
3.6 KiB
C
155 lines
3.6 KiB
C
# define YYFLAG -1000
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# define YYERROR goto yyerrlab
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# define YYACCEPT return(0)
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# define YYABORT return(1)
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#ifdef YYDEBUG /* RRR - 10/9/85 */
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#define yyprintf(a, b, c) printf(a, b, c)
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#else
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#define yyprintf(a, b, c)
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#endif
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/* parser for yacc output */
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YYSTYPE yyv[YYMAXDEPTH]; /* where the values are stored */
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int yychar = -1; /* current input token number */
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int yynerrs = 0; /* number of errors */
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short yyerrflag = 0; /* error recovery flag */
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int NEAR yyparse(void)
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{
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short yys[YYMAXDEPTH];
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short yyj, yym;
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register YYSTYPE *yypvt;
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register short yystate, *yyps, yyn;
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register YYSTYPE *yypv;
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register short *yyxi;
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yystate = 0;
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yychar = -1;
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yynerrs = 0;
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yyerrflag = 0;
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yyps= &yys[-1];
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yypv= &yyv[-1];
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yystack: /* put a state and value onto the stack */
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yyprintf( "state %d, char 0%o\n", yystate, yychar );
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if( ++yyps> &yys[YYMAXDEPTH] )
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{
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yyerror( "yacc stack overflow" );
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return(1);
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}
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*yyps = yystate;
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++yypv;
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*yypv = yyval;
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yynewstate:
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yyn = yypact[yystate];
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if( yyn<= YYFLAG ) goto yydefault; /* simple state */
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if( yychar<0 ) if( (yychar=yylex())<0 ) yychar=0;
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if( (yyn += (short)yychar)<0 || yyn >= YYLAST ) goto yydefault;
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if( yychk[ yyn=yyact[ yyn ] ] == yychar )
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{
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/* valid shift */
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yychar = -1;
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yyval = yylval;
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yystate = yyn;
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if( yyerrflag > 0 ) --yyerrflag;
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goto yystack;
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}
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yydefault:
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/* default state action */
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if( (yyn=yydef[yystate]) == -2 )
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{
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if( yychar<0 ) if( (yychar=yylex())<0 ) yychar = 0;
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/* look through exception table */
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for( yyxi=yyexca; (*yyxi!= (-1)) || (yyxi[1]!=yystate) ; yyxi += 2 ) ; /* VOID */
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for(yyxi+=2; *yyxi >= 0; yyxi+=2)
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{
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if( *yyxi == yychar ) break;
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}
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if( (yyn = yyxi[1]) < 0 ) return(0); /* accept */
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}
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if( yyn == 0 )
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{
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/* error */
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/* error ... attempt to resume parsing */
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switch( yyerrflag )
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{
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case 0: /* brand new error */
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yyerror( "syntax error" );
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++yynerrs;
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case 1:
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case 2: /* incompletely recovered error ... try again */
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yyerrflag = 3;
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/* find a state where "error" is a legal shift action */
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while ( yyps >= yys )
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{
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yyn = yypact[*yyps] + YYERRCODE;
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if( yyn>= 0 && yyn < YYLAST && yychk[yyact[yyn]] == YYERRCODE )
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{
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yystate = yyact[yyn]; /* simulate a shift of "error" */
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goto yystack;
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}
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yyn = yypact[*yyps];
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/* the current yyps has no shift onn "error", pop stack */
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yyprintf( "error recovery pops state %d, uncovers %d\n", *yyps, yyps[-1] );
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--yyps;
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--yypv;
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}
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/* there is no state on the stack with an error shift ... abort */
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yyabort:
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return(1);
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case 3: /* no shift yet; clobber input char */
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yyprintf( "error recovery discards char %d\n", yychar, 0 );
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if( yychar == 0 ) goto yyabort; /* don't discard EOF, quit */
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yychar = -1;
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goto yynewstate; /* try again in the same state */
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}
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}
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/* reduction by production yyn */
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yyprintf("reduce %d\n",yyn, 0);
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yyps -= yyr2[yyn];
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yypvt = yypv;
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yypv -= yyr2[yyn];
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yyval = yypv[1];
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yym=yyn;
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/* consult goto table to find next state */
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yyn = yyr1[yyn];
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yyj = yypgo[yyn] + *yyps + 1;
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if( yyj>=YYLAST || yychk[ yystate = yyact[yyj] ] != -yyn ) yystate = yyact[yypgo[yyn]];
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switch(yym)
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{
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$A
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}
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goto yystack; /* stack new state and value */
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}
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