yacc.c

lcc,一个可变目标c语言编译器的源码

# define ID 257
# define CON 258
# define UNARYMINUS 259
#define yyclearin yychar = -1
#define yyerrok yyerrflag = 0
extern int yychar;
extern short yyerrflag;
#ifndef YYMAXDEPTH
#define YYMAXDEPTH 150
#endif
#ifndef YYSTYPE
#define YYSTYPE int
#endif
YYSTYPE yylval, yyval;
# define YYERRCODE 256



#include <stdio.h>

# define U(x) x
# define NLSTATE yyprevious=YYNEWLINE
# define BEGIN yybgin = yysvec + 1 +
# define INITIAL 0
# define YYLERR yysvec
# define YYSTATE (yyestate-yysvec-1)
# define YYOPTIM 1
# define YYLMAX 200
# define output(c) (void)putc(c,yyout)
# define input() (((yytchar=yysptr>yysbuf?U(*--yysptr):getc(yyin))==10?(yylineno++,yytchar):yytchar)==EOF?0:yytchar)
# define unput(c) {yytchar= (c);if(yytchar=='\n')yylineno--;*yysptr++=yytchar;}
# define yymore() (yymorfg=1)
# define ECHO fprintf(yyout, "%s",yytext)
# define REJECT { nstr = yyreject(); goto yyfussy;}
int yyleng; extern char yytext[];
int yymorfg;
extern char *yysptr, yysbuf[];
int yytchar;
FILE *yyin = NULL, *yyout = NULL;
extern int yylineno;
struct yysvf { 
	struct yywork *yystoff;
	struct yysvf *yyother;
	int *yystops;};
struct yysvf *yyestate;
extern struct yysvf yysvec[], *yybgin;
# define YYNEWLINE 10
yylex(){
int nstr; extern int yyprevious;
while((nstr = yylook()) >= 0)
yyfussy: switch(nstr){
case 0:
if(yywrap()) return(0); break;
case 1:
 return ID;
break;
case 2:
                 return CON;
break;
case 3:
                  ;
break;
case 4:
                   return yytext[0];
break;
case -1:
break;
default:
fprintf(yyout,"bad switch yylook %d",nstr);
} return(0); }
/* end of yylex */
int yyvstop[] ={
0,

4,
0,

3,
4,
0,

2,
4,
0,

1,
4,
0,

2,
0,

1,
0,
0};
# define YYTYPE char
struct yywork { YYTYPE verify, advance; } yycrank[] ={
0,0,	0,0,	1,3,	0,0,	
0,0,	0,0,	0,0,	0,0,	
0,0,	0,0,	1,4,	1,3,	
0,0,	0,0,	0,0,	0,0,	
0,0,	0,0,	0,0,	0,0,	
0,0,	0,0,	0,0,	0,0,	
0,0,	0,0,	0,0,	0,0,	
0,0,	0,0,	0,0,	0,0,	
0,0,	0,0,	0,0,	0,0,	
0,0,	0,0,	0,0,	0,0,	
0,0,	0,0,	0,0,	0,0,	
0,0,	0,0,	0,0,	0,0,	
0,0,	1,5,	5,7,	5,7,	
5,7,	5,7,	5,7,	5,7,	
5,7,	5,7,	5,7,	5,7,	
0,0,	0,0,	0,0,	0,0,	
0,0,	0,0,	1,6,	6,8,	
6,8,	6,8,	6,8,	6,8,	
6,8,	6,8,	6,8,	6,8,	
6,8,	0,0,	0,0,	0,0,	
0,0,	0,0,	0,0,	0,0,	
6,8,	6,8,	6,8,	6,8,	
6,8,	6,8,	6,8,	6,8,	
6,8,	6,8,	6,8,	6,8,	
6,8,	6,8,	6,8,	6,8,	
6,8,	6,8,	6,8,	6,8,	
6,8,	6,8,	6,8,	6,8,	
6,8,	6,8,	0,0,	0,0,	
0,0,	0,0,	6,8,	0,0,	
6,8,	6,8,	6,8,	6,8,	
6,8,	6,8,	6,8,	6,8,	
6,8,	6,8,	6,8,	6,8,	
6,8,	6,8,	6,8,	6,8,	
6,8,	6,8,	6,8,	6,8,	
6,8,	6,8,	6,8,	6,8,	
6,8,	6,8,	0,0,	0,0,	
0,0};
struct yysvf yysvec[] ={
0,	0,	0,
yycrank+-1,	0,		0,	
yycrank+0,	yysvec+1,	0,	
yycrank+0,	0,		yyvstop+1,
yycrank+0,	0,		yyvstop+3,
yycrank+2,	0,		yyvstop+6,
yycrank+19,	0,		yyvstop+9,
yycrank+0,	yysvec+5,	yyvstop+12,
yycrank+0,	yysvec+6,	yyvstop+14,
0,	0,	0};
struct yywork *yytop = yycrank+141;
struct yysvf *yybgin = yysvec+1;
char yymatch[] ={
00  ,01  ,01  ,01  ,01  ,01  ,01  ,01  ,
01  ,011 ,012 ,01  ,01  ,01  ,01  ,01  ,
01  ,01  ,01  ,01  ,01  ,01  ,01  ,01  ,
01  ,01  ,01  ,01  ,01  ,01  ,01  ,01  ,
011 ,01  ,01  ,01  ,01  ,01  ,01  ,01  ,
01  ,01  ,01  ,01  ,01  ,01  ,01  ,01  ,
'0' ,'0' ,'0' ,'0' ,'0' ,'0' ,'0' ,'0' ,
'0' ,'0' ,01  ,01  ,01  ,01  ,01  ,01  ,
01  ,'A' ,'A' ,'A' ,'A' ,'A' ,'A' ,'A' ,
'A' ,'A' ,'A' ,'A' ,'A' ,'A' ,'A' ,'A' ,
'A' ,'A' ,'A' ,'A' ,'A' ,'A' ,'A' ,'A' ,
'A' ,'A' ,'A' ,01  ,01  ,01  ,01  ,'A' ,
01  ,'A' ,'A' ,'A' ,'A' ,'A' ,'A' ,'A' ,
'A' ,'A' ,'A' ,'A' ,'A' ,'A' ,'A' ,'A' ,
'A' ,'A' ,'A' ,'A' ,'A' ,'A' ,'A' ,'A' ,
'A' ,'A' ,'A' ,01  ,01  ,01  ,01  ,01  ,
0};
char yyextra[] ={
0,0,0,0,0,0,0,0,
0};
/*	ncform	4.1	83/08/11	*/

int yylineno =1;
# define YYU(x) x
# define NLSTATE yyprevious=YYNEWLINE
char yytext[YYLMAX];
struct yysvf *yylstate [YYLMAX], **yylsp, **yyolsp;
char yysbuf[YYLMAX];
char *yysptr = yysbuf;
int *yyfnd;
extern struct yysvf *yyestate;
int yyprevious = YYNEWLINE;
yylook(){
	register struct yysvf *yystate, **lsp;
	register struct yywork *yyt;
	struct yysvf *yyz;
	int yych;
	struct yywork *yyr;
# ifdef LEXDEBUG
	int debug;
# endif
	char *yylastch;
	/* start off machines */
# ifdef LEXDEBUG
	debug = 0;
# endif
	if (!yymorfg)
		yylastch = yytext;
	else {
		yymorfg=0;
		yylastch = yytext+yyleng;
		}
	for(;;){
		lsp = yylstate;
		yyestate = yystate = yybgin;
		if (yyprevious==YYNEWLINE) yystate++;
		for (;;){
# ifdef LEXDEBUG
			if(debug)fprintf(yyout,"state %d\n",yystate-yysvec-1);
# endif
			yyt = yystate->yystoff;
			if(yyt == yycrank){		/* may not be any transitions */
				yyz = yystate->yyother;
				if(yyz == 0)break;
				if(yyz->yystoff == yycrank)break;
				}
			*yylastch++ = yych = input();
		tryagain:
# ifdef LEXDEBUG
			if(debug){
				fprintf(yyout,"char ");
				allprint(yych);
				putchar('\n');
				}
# endif
			yyr = yyt;
			if ( yyt > yycrank){
				yyt = yyr + yych;
				if (yyt <= yytop && yyt->verify+yysvec == yystate){
					if(yyt->advance+yysvec == YYLERR)	/* error transitions */
						{unput(*--yylastch);break;}
					*lsp++ = yystate = yyt->advance+yysvec;
					goto contin;
					}
				}
# ifdef YYOPTIM
			else if(yyt < yycrank) {		/* r < yycrank */
				yyt = yyr = yycrank+(yycrank-yyt);
# ifdef LEXDEBUG
				if(debug)fprintf(yyout,"compressed state\n");
# endif
				yyt = yyt + yych;
				if(yyt <= yytop && yyt->verify+yysvec == yystate){
					if(yyt->advance+yysvec == YYLERR)	/* error transitions */
						{unput(*--yylastch);break;}
					*lsp++ = yystate = yyt->advance+yysvec;
					goto contin;
					}
				yyt = yyr + YYU(yymatch[yych]);
# ifdef LEXDEBUG
				if(debug){
					fprintf(yyout,"try fall back character ");
					allprint(YYU(yymatch[yych]));
					putchar('\n');
					}
# endif
				if(yyt <= yytop && yyt->verify+yysvec == yystate){
					if(yyt->advance+yysvec == YYLERR)	/* error transition */
						{unput(*--yylastch);break;}
					*lsp++ = yystate = yyt->advance+yysvec;
					goto contin;
					}
				}
			if ((yystate = yystate->yyother) && (yyt= yystate->yystoff) != yycrank){
# ifdef LEXDEBUG
				if(debug)fprintf(yyout,"fall back to state %d\n",yystate-yysvec-1);
# endif
				goto tryagain;
				}
# endif
			else
				{unput(*--yylastch);break;}
		contin:
# ifdef LEXDEBUG
			if(debug){
				fprintf(yyout,"state %d char ",yystate-yysvec-1);
				allprint(yych);
				putchar('\n');
				}
# endif
			;
			}
# ifdef LEXDEBUG
		if(debug){
			fprintf(yyout,"stopped at %d with ",*(lsp-1)-yysvec-1);
			allprint(yych);
			putchar('\n');
			}
# endif
		while (lsp-- > yylstate){
			*yylastch-- = 0;
			if (*lsp != 0 && (yyfnd= (*lsp)->yystops) && *yyfnd > 0){
				yyolsp = lsp;
				if(yyextra[*yyfnd]){		/* must backup */
					while(yyback((*lsp)->yystops,-*yyfnd) != 1 && lsp > yylstate){
						lsp--;
						unput(*yylastch--);
						}
					}
				yyprevious = YYU(*yylastch);
				yylsp = lsp;
				yyleng = yylastch-yytext+1;
				yytext[yyleng] = 0;
# ifdef LEXDEBUG
				if(debug){
					fprintf(yyout,"\nmatch ");
					sprint(yytext);
					fprintf(yyout," action %d\n",*yyfnd);
					}
# endif
				return(*yyfnd++);
				}
			unput(*yylastch);
			}
		if (yytext[0] == 0  /* && feof(yyin) */)
			{
			yysptr=yysbuf;
			return(0);
			}
		yyprevious = yytext[0] = input();
		if (yyprevious>0)
			output(yyprevious);
		yylastch=yytext;
# ifdef LEXDEBUG
		if(debug)putchar('\n');
# endif
		}
	}
yyback(p, m)
	int *p;
{
if (p==0) return(0);
while (*p)
	{
	if (*p++ == m)
		return(1);
	}
return(0);
}
	/* the following are only used in the lex library */
yyinput(){
	return(input());
	}
yyoutput(c)
  int c; {
	output(c);
	}
yyunput(c)
   int c; {
	unput(c);
	}

main() {
	yyin = stdin; yyout = stdout;
	yyparse();
	return 0;
}

/* yyerror - issue error message */
yyerror(s) char *s; {
        printf("%s\n", s);
}
short yyexca[] ={
-1, 1,
	0, -1,
	-2, 0,
	};
# define YYNPROD 15
# define YYLAST 249
short yyact[]={

  12,   2,   9,   8,  17,  11,  25,  17,  15,  18,
  16,  10,  18,  17,  15,   7,  16,  13,  18,   5,
   3,   1,   0,  19,  20,   0,   0,  21,  22,  23,
  24,   0,   0,   0,   0,   0,   0,   0,   0,   0,
   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,
   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,
   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,
   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,
   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,
   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,
   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,
   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,
   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,
   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,
   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,
   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,
   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,
   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,
   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,
   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,
   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,
   0,   0,   0,   0,   0,   0,   0,   6,  14,   0,
   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,
   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,
   0,   0,   0,   0,   0,   0,   0,   4,   6 };
short yypact[]={

-1000,  -9,-1000,   5,  -7, -59,-1000,-1000,-1000, -40,
 -29, -40, -40,-1000,-1000, -40, -40, -40, -40, -38,
 -35, -38, -38,-1000,-1000,-1000 };
short yypgo[]={

   0,  21,  20,  17,  11 };
short yyr1[]={

   0,   1,   1,   1,   1,   2,   4,   4,   4,   4,
   4,   4,   4,   4,   3 };
short yyr2[]={

   0,   0,   2,   3,   3,   3,   3,   3,   3,   3,
   2,   3,   1,   1,   1 };
short yychk[]={

-1000,  -1,  10,  -2, 256,  -3, 257,  10,  10,  61,
  -4,  45,  40,  -3, 258,  43,  45,  42,  47,  -4,
  -4,  -4,  -4,  -4,  -4,  41 };
short yydef[]={

   1,  -2,   2,   0,   0,   0,  14,   3,   4,   0,
   5,   0,   0,  12,  13,   0,   0,   0,   0,  10,
   0,   6,   7,   8,   9,  11 };
#ifndef lint
#endif

# define YYFLAG -1000
# define YYERROR goto yyerrlab
# define YYACCEPT return(0)
# define YYABORT return(1)

/*	parser for yacc output	*/

#ifdef YYDEBUG
int yydebug = 0; /* 1 for debugging */
#endif
YYSTYPE yyv[YYMAXDEPTH]; /* where the values are stored */
int yychar = -1; /* current input token number */
int yynerrs = 0;  /* number of errors */
short yyerrflag = 0;  /* error recovery flag */

yyparse() {

	short yys[YYMAXDEPTH];
	short yyj, yym;
	register YYSTYPE *yypvt;
	register short yystate, *yyps, yyn;
	register YYSTYPE *yypv;
	register short *yyxi;

	yystate = 0;
	yychar = -1;
	yynerrs = 0;
	yyerrflag = 0;
	yyps= &yys[-1];
	yypv= &yyv[-1];

 yystack:    /* put a state and value onto the stack */

#ifdef YYDEBUG
	if( yydebug  ) printf( "state %d, char 0%o\n", yystate, yychar );
#endif
		if( ++yyps> &yys[YYMAXDEPTH-1] ) { yyerror( "yacc stack overflow" ); return(1); }
		*yyps = yystate;
		++yypv;
		*yypv = yyval;

 yynewstate:

	yyn = yypact[yystate];

	if( yyn<= YYFLAG ) goto yydefault; /* simple state */

	if( yychar<0 ) if( (yychar=yylex())<0 ) yychar=0;
	if( (yyn += yychar)<0 || yyn >= YYLAST ) goto yydefault;

	if( yychk[ yyn=yyact[ yyn ] ] == yychar ){ /* valid shift */
		yychar = -1;
		yyval = yylval;
		yystate = yyn;
		if( yyerrflag > 0 ) --yyerrflag;
		goto yystack;
		}

 yydefault:
	/* default state action */

	if( (yyn=yydef[yystate]) == -2 ) {
		if( yychar<0 ) if( (yychar=yylex())<0 ) yychar = 0;
		/* look through exception table */

		for( yyxi=yyexca; (*yyxi!= (-1)) || (yyxi[1]!=yystate) ; yyxi += 2 ) ; /* VOID */

		while( *(yyxi+=2) >= 0 ){
			if( *yyxi == yychar ) break;
			}
		if( (yyn = yyxi[1]) < 0 ) return(0);   /* accept */
		}

	if( yyn == 0 ){ /* error */
		/* error ... attempt to resume parsing */

		switch( yyerrflag ){

		case 0:   /* brand new error */

			yyerror( "syntax error" );
		yyerrlab:
			++yynerrs;

		case 1:
		case 2: /* incompletely recovered error ... try again */

			yyerrflag = 3;

			/* find a state where "error" is a legal shift action */

			while ( yyps >= yys ) {
			   yyn = yypact[*yyps] + YYERRCODE;
			   if( yyn>= 0 && yyn < YYLAST && yychk[yyact[yyn]] == YYERRCODE ){
			      yystate = yyact[yyn];  /* simulate a shift of "error" */
			      goto yystack;
			      }
			   yyn = yypact[*yyps];

			   /* the current yyps has no shift onn "error", pop stack */

#ifdef YYDEBUG
			   if( yydebug ) printf( "error recovery pops state %d, uncovers %d\n", *yyps, yyps[-1] );
#endif
			   --yyps;
			   --yypv;
			   }

			/* there is no state on the stack with an error shift ... abort */

	yyabort:
			return(1);


		case 3:  /* no shift yet; clobber input char */

#ifdef YYDEBUG
			if( yydebug ) printf( "error recovery discards char %d\n", yychar );
#endif

			if( yychar == 0 ) goto yyabort; /* don't discard EOF, quit */
			yychar = -1;
			goto yynewstate;   /* try again in the same state */

			}

		}

	/* reduction by production yyn */

#ifdef YYDEBUG
		if( yydebug ) printf("reduce %d\n",yyn);
#endif
		yyps -= yyr2[yyn];
		yypvt = yypv;
		yypv -= yyr2[yyn];
		yyval = yypv[1];
		yym=yyn;
			/* consult goto table to find next state */
		yyn = yyr1[yyn];
		yyj = yypgo[yyn] + *yyps + 1;
		if( yyj>=YYLAST || yychk[ yystate = yyact[yyj] ] != -yyn ) yystate = yyact[yypgo[yyn]];
		switch(yym){
			
case 4:
{ yyerrok; } break;
case 5:
{ printf("store\n"); } break;
case 6:
{ printf("add\n"); } break;
case 7:
{ printf("negate\nadd\n"); } break;
case 8:
{ printf("multiply\n"); } break;
case 9:
{ printf("divide\n"); } break;
case 10:
{ printf("negate\n"); } break;
case 12:
{ printf("load\n"); } break;
case 13:
{ printf("push %s\n", yytext); } break;
case 14:
{ printf("%s\n", yytext); } break;
		}
		goto yystack;  /* stack new state and value */

	}
int yywrap() { return 1; }