add1.y.c

yacc和lex的一个例子代码,完全原创

extern int yylex();
extern void yyerror(const char * s);
#ifdef __cplusplus
#  include <stdio.h>
#  include <yacc.h>
#endif	/* __cplusplus */ 
# define INTEGER 257
#define yyclearin yychar = -1
#define yyerrok yyerrflag = 0
extern int yychar;
#ifndef YYMAXDEPTH
#define YYMAXDEPTH 150
#endif

/* __YYSCLASS defines the scoping/storage class for global objects
 * that are NOT renamed by the -p option.  By default these names
 * are going to be 'static' so that multi-definition errors
 * will not occur with multiple parsers.
 * If you want (unsupported) access to internal names you need
 * to define this to be null so it implies 'extern' scope.
 * This should not be used in conjunction with -p.
 */
#ifndef __YYSCLASS
# define __YYSCLASS static
#endif
#ifndef YYSTYPE
#define YYSTYPE int
#endif
YYSTYPE yylval;
__YYSCLASS YYSTYPE yyval;
typedef int yytabelem;
# define YYERRCODE 256


void yyerror(const char * s)
{
	fprintf(stderr, "%s\n", s);
}

int main(void)
{
	yyparse();
	return 0;
}

#include "add1.c"
__YYSCLASS yytabelem yyexca[] ={
-1, 1,
	0, -1,
	-2, 0,
	};
# define YYNPROD 8
# define YYLAST 39
__YYSCLASS yytabelem yyact[]={

    10,     9,     3,     6,     5,     4,     2,     1,     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,     7,     0,     8 };
__YYSCLASS yytabelem yypact[]={

 -3400,  -255,    -7, -3400,  -256,  -257, -3400, -3400, -3400, -3400,
 -3400 };
__YYSCLASS yytabelem yypgo[]={

     0,     7,     6,     5,     4 };
__YYSCLASS yytabelem yyr1[]={

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

     0,     7,     0,     5,     5,     3,     5,     5 };
__YYSCLASS yytabelem yychk[]={

 -3400,    -1,    -2,   257,    -3,    -4,    10,    43,    45,   257,
   257 };
__YYSCLASS yytabelem yydef[]={

     2,    -2,     0,     5,     0,     0,     1,     3,     4,     6,
     7 };
typedef struct { char *t_name; int t_val; } yytoktype;
#ifndef YYDEBUG
#	define YYDEBUG	1	/* allow debugging */
#endif

#if YYDEBUG

__YYSCLASS yytoktype yytoks[] =
{
	"INTEGER",	257,
	"-unknown-",	-1	/* ends search */
};

__YYSCLASS char * yyreds[] =
{
	"-no such reduction-",
	"program : program expr '\n'",
	"program : /* empty */",
	"expradd : expr '+'",
	"exprminus : expr '-'",
	"expr : INTEGER",
	"expr : expradd INTEGER",
	"expr : exprminus INTEGER",
};
#endif /* YYDEBUG */
#define YYFLAG  (-3400)
/* @(#) $Revision: 70.7 $ */    

/*
** Skeleton parser driver for yacc output
*/

#if defined(NLS) && !defined(NL_SETN)
#include <msgbuf.h>
#endif

#ifndef nl_msg
#define nl_msg(i,s) (s)
#endif

/*
** yacc user known macros and defines
*/
#define YYERROR		goto yyerrlab

#ifndef __RUNTIME_YYMAXDEPTH
#define YYACCEPT	return(0)
#define YYABORT		return(1)
#else
#define YYACCEPT	{free_stacks(); return(0);}
#define YYABORT		{free_stacks(); return(1);}
#endif

#define YYBACKUP( newtoken, newvalue )\
{\
	if ( yychar >= 0 || ( yyr2[ yytmp ] >> 1 ) != 1 )\
	{\
		yyerror( (nl_msg(30001,"syntax error - cannot backup")) );\
		goto yyerrlab;\
	}\
	yychar = newtoken;\
	yystate = *yyps;\
	yylval = newvalue;\
	goto yynewstate;\
}
#define YYRECOVERING()	(!!yyerrflag)
#ifndef YYDEBUG
#	define YYDEBUG	1	/* make debugging available */
#endif

/*
** user known globals
*/

#ifdef YYREENTRANT
__thread int yydebug;		/* set to 1 to get debugging */
#else
int yydebug;			/* set to 1 to get debugging */
#endif

/*
** driver internal defines
*/
/* define for YYFLAG now generated by yacc program. */
/*#define YYFLAG		(FLAGVAL)*/

/*
** global variables used by the parser
*/
# ifndef __RUNTIME_YYMAXDEPTH

#   ifdef YYREENTRANT
__thread __YYSCLASS YYSTYPE yyv[ YYMAXDEPTH ];  /* value stack */
__thread __YYSCLASS int yys[ YYMAXDEPTH ];      /* state stack */
#   else
__YYSCLASS YYSTYPE yyv[ YYMAXDEPTH ];           /* value stack */
__YYSCLASS int yys[ YYMAXDEPTH ];               /* state stack */
#   endif

# else

#  ifdef YYREENTRANT
__thread __YYSCLASS YYSTYPE *yyv;               /* pointer to malloc'ed stack st
value stack */
__thread __YYSCLASS int *yys;                   /* pointer to malloc'ed stack st
ack */
#  else
__YYSCLASS YYSTYPE *yyv;                        /* pointer to malloc'ed value st
ack */
__YYSCLASS int *yys;                            /* pointer to malloc'ed stack stack */
#  endif

#if defined(__STDC__) || defined (__cplusplus)
#include <stdlib.h>
#else
	extern char *malloc();
	extern char *realloc();
	extern void free();
#endif /* __STDC__ or __cplusplus */


static int allocate_stacks(); 
static void free_stacks();
# ifndef YYINCREMENT
# define YYINCREMENT (YYMAXDEPTH/2) + 10
# endif
# endif	/* __RUNTIME_YYMAXDEPTH */
long  yymaxdepth = YYMAXDEPTH;


#ifdef YYREENTRANT

__thread __YYSCLASS YYSTYPE *yypv;      /* top of value stack */
__thread __YYSCLASS int *yyps;          /* top of state stack */

__thread __YYSCLASS int yystate;        /* current state */
__thread __YYSCLASS int yytmp;          /* extra var (lasts between blocks) */

__thread int yynerrs;                   /* number of errors */
__thread __YYSCLASS int yyerrflag;      /* error recovery flag */
__thread int yychar;                    /* current input token number */

__thread extern int yyinit_key;           /* init TLS data once */
extern int TLS_INIT; 

#else

__YYSCLASS YYSTYPE *yypv;               /* top of value stack */
__YYSCLASS int *yyps;                   /* top of state stack */

__YYSCLASS int yystate;                 /* current state */
__YYSCLASS int yytmp;                   /* extra var (lasts between blocks) */

int yynerrs;                            /* number of errors */
__YYSCLASS int yyerrflag;               /* error recovery flag */
int yychar;
#endif


/*
** yyparse - return 0 if worked, 1 if syntax error not recovered from
l*/
int
yyparse()
{
	register YYSTYPE *yypvt;	/* top of value stack for $vars */


        /*
        ** Initialize externals - yyparse may be called more than once
        */

#ifdef YYREENTRANT
        if (yyinit_key != TLS_INIT)
        {
            yyinit_key = TLS_INIT; 
            yyinit_tls();
        }
#endif

	/*
	** Initialize externals - yyparse may be called more than once
	*/
# ifdef __RUNTIME_YYMAXDEPTH
	if (allocate_stacks()) YYABORT;
# endif
	yypv = &yyv[-1];
	yyps = &yys[-1];
	yystate = 0;
	yytmp = 0;
	yynerrs = 0;
	yyerrflag = 0;
	yychar = -1;

	goto yystack;
	{
		register YYSTYPE *yy_pv;	/* top of value stack */
		register int *yy_ps;		/* top of state stack */
		register int yy_state;		/* current state */
		register int  yy_n;		/* internal state number info */

		/*
		** get globals into registers.
		** branch to here only if YYBACKUP was called.
		*/
	yynewstate:
		yy_pv = yypv;
		yy_ps = yyps;
		yy_state = yystate;
		goto yy_newstate;

		/*
		** get globals into registers.
		** either we just started, or we just finished a reduction
		*/
	yystack:
		yy_pv = yypv;
		yy_ps = yyps;
		yy_state = yystate;

		/*
		** top of for (;;) loop while no reductions done
		*/
	yy_stack:
		/*
		** put a state and value onto the stacks
		*/
#if YYDEBUG
		/*
		** if debugging, look up token value in list of value vs.
		** name pairs.  0 and negative (-1) are special values.
		** Note: linear search is used since time is not a real
		** consideration while debugging.
		*/
		if ( yydebug )
		{
			register int yy_i;

			printf( "State %d, token ", yy_state );
			if ( yychar == 0 )
				printf( "end-of-file\n" );
			else if ( yychar < 0 )
				printf( "-none-\n" );
			else
			{
				for ( yy_i = 0; yytoks[yy_i].t_val >= 0;
					yy_i++ )
				{
					if ( yytoks[yy_i].t_val == yychar )
						break;
				}
				printf( "%s\n", yytoks[yy_i].t_name );
			}