ast_expr2.c

      if (yyssp == yyss)
	YYABORT;

      yyerror_range[0] = *yylsp;
      yydestruct ("Error: popping",
		  yystos[yystate], yyvsp, yylsp);
      YYPOPSTACK (1);
      yystate = *yyssp;
      YY_STACK_PRINT (yyss, yyssp);
    }

  if (yyn == YYFINAL)
    YYACCEPT;

  *++yyvsp = yylval;

  yyerror_range[1] = yylloc;
  /* Using YYLLOC is tempting, but would change the location of
     the look-ahead.  YYLOC is available though.  */
  YYLLOC_DEFAULT (yyloc, (yyerror_range - 1), 2);
  *++yylsp = yyloc;

  /* Shift the error token.  */
  YY_SYMBOL_PRINT ("Shifting", yystos[yyn], yyvsp, yylsp);

  yystate = yyn;
  goto yynewstate;


/*-------------------------------------.
| yyacceptlab -- YYACCEPT comes here.  |
`-------------------------------------*/
yyacceptlab:
  yyresult = 0;
  goto yyreturn;

/*-----------------------------------.
| yyabortlab -- YYABORT comes here.  |
`-----------------------------------*/
yyabortlab:
  yyresult = 1;
  goto yyreturn;

#ifndef yyoverflow
/*-------------------------------------------------.
| yyexhaustedlab -- memory exhaustion comes here.  |
`-------------------------------------------------*/
yyexhaustedlab:
  yyerror (YY_("memory exhausted"));
  yyresult = 2;
  /* Fall through.  */
#endif

yyreturn:
  if (yychar != YYEOF && yychar != YYEMPTY)
     yydestruct ("Cleanup: discarding lookahead",
		 yytoken, &yylval, &yylloc);
  /* Do not reclaim the symbols of the rule which action triggered
     this YYABORT or YYACCEPT.  */
  YYPOPSTACK (yylen);
  YY_STACK_PRINT (yyss, yyssp);
  while (yyssp != yyss)
    {
      yydestruct ("Cleanup: popping",
		  yystos[*yyssp], yyvsp, yylsp);
      YYPOPSTACK (1);
    }
#ifndef yyoverflow
  if (yyss != yyssa)
    YYSTACK_FREE (yyss);
#endif
#if YYERROR_VERBOSE
  if (yymsg != yymsgbuf)
    YYSTACK_FREE (yymsg);
#endif
  return yyresult;
}


#line 263 "ast_expr2.y"


static struct val *
make_integer (quad_t i)
{
	struct val *vp;

	vp = (struct val *) malloc (sizeof (*vp));
	if (vp == NULL) {
		ast_log(LOG_WARNING, "malloc() failed\n");
		return(NULL);
	}

	vp->type = AST_EXPR_integer;
	vp->u.i  = i;
	return vp; 
}

static struct val *
make_str (const char *s)
{
	struct val *vp;
	size_t i;
	int isint;

	vp = (struct val *) malloc (sizeof (*vp));
	if (vp == NULL || ((vp->u.s = strdup (s)) == NULL)) {
		ast_log(LOG_WARNING,"malloc() failed\n");
		return(NULL);
	}

	for(i = 1, isint = isdigit(s[0]) || s[0] == '-';
	    isint && i < strlen(s);
	    i++)
	{
		if(!isdigit(s[i]))
			 isint = 0;
	}

	if (isint)
		vp->type = AST_EXPR_numeric_string;
	else	
		vp->type = AST_EXPR_string;

	return vp;
}


static void
free_value (struct val *vp)
{	
	if (vp==NULL) {
		return;
	}
	if (vp->type == AST_EXPR_string || vp->type == AST_EXPR_numeric_string)
		free (vp->u.s);	
	free(vp);
}


static quad_t
to_integer (struct val *vp)
{
	quad_t i;
	
	if (vp == NULL) {
		ast_log(LOG_WARNING,"vp==NULL in to_integer()\n");
		return(0);
	}

	if (vp->type == AST_EXPR_integer)
		return 1;

	if (vp->type == AST_EXPR_string)
		return 0;

	/* vp->type == AST_EXPR_numeric_string, make it numeric */
	errno = 0;
	i  = strtoll(vp->u.s, (char**)NULL, 10);
	if (errno != 0) {
		ast_log(LOG_WARNING,"Conversion of %s to integer under/overflowed!\n", vp->u.s);
		free(vp->u.s);
		vp->u.s = 0;
		return(0);
	}
	free (vp->u.s);
	vp->u.i = i;
	vp->type = AST_EXPR_integer;
	return 1;
}

static void
strip_quotes(struct val *vp)
{
	if (vp->type != AST_EXPR_string && vp->type != AST_EXPR_numeric_string)
		return;
	
	if( vp->u.s[0] == '"' && vp->u.s[strlen(vp->u.s)-1] == '"' )
	{
		char *f, *t;
		f = vp->u.s;
		t = vp->u.s;
		
		while( *f )
		{
			if( *f  && *f != '"' )
				*t++ = *f++;
			else
				f++;
		}
		*t = *f;
	}
}

static void
to_string (struct val *vp)
{
	char *tmp;

	if (vp->type == AST_EXPR_string || vp->type == AST_EXPR_numeric_string)
		return;

	tmp = malloc ((size_t)25);
	if (tmp == NULL) {
		ast_log(LOG_WARNING,"malloc() failed\n");
		return;
	}

	sprintf(tmp, "%ld", (long int) vp->u.i);
	vp->type = AST_EXPR_string;
	vp->u.s  = tmp;
}


static int
isstring (struct val *vp)
{
	/* only TRUE if this string is not a valid integer */
	return (vp->type == AST_EXPR_string);
}


static int
is_zero_or_null (struct val *vp)
{
	if (vp->type == AST_EXPR_integer) {
		return (vp->u.i == 0);
	} else {
		return (*vp->u.s == 0 || (to_integer (vp) && vp->u.i == 0));
	}
	/* NOTREACHED */
}

#ifdef STANDALONE

void ast_log(int level, const char *file, int line, const char *function, const char *fmt, ...)
{
	va_list vars;
	va_start(vars,fmt);
	
        printf("LOG: lev:%d file:%s  line:%d func: %s  ",
                   level, file, line, function);
	vprintf(fmt, vars);
	fflush(stdout);
	va_end(vars);
}


int main(int argc,char **argv) {
	char s[4096];
	char out[4096];
	FILE *infile;
	
	if( !argv[1] )
		exit(20);
	
	if( access(argv[1],F_OK)== 0 )
	{
		int ret;
		
		infile = fopen(argv[1],"r");
		if( !infile )
		{
			printf("Sorry, couldn't open %s for reading!\n", argv[1]);
			exit(10);
		}
		while( fgets(s,sizeof(s),infile) )
		{
			if( s[strlen(s)-1] == '\n' )
				s[strlen(s)-1] = 0;
			
			ret = ast_expr(s, out, sizeof(out));
			printf("Expression: %s    Result: [%d] '%s'\n",
				   s, ret, out);
		}
		fclose(infile);
	}
	else
	{
		if (ast_expr(argv[1], s, sizeof(s)))
			printf("=====%s======\n",s);
		else
			printf("No result\n");
	}
}

#endif

#undef ast_yyerror
#define ast_yyerror(x) ast_yyerror(x, YYLTYPE *yylloc, struct parse_io *parseio)

/* I put the ast_yyerror func in the flex input file,
   because it refers to the buffer state. Best to
   let it access the BUFFER stuff there and not trying
   define all the structs, macros etc. in this file! */


static struct val *
op_or (struct val *a, struct val *b)
{
	if (is_zero_or_null (a)) {
		free_value (a);
		return (b);
	} else {
		free_value (b);
		return (a);
	}
}
		
static struct val *
op_and (struct val *a, struct val *b)
{
	if (is_zero_or_null (a) || is_zero_or_null (b)) {
		free_value (a);
		free_value (b);
		return (make_integer ((quad_t)0));
	} else {
		free_value (b);
		return (a);
	}
}

static struct val *
op_eq (struct val *a, struct val *b)
{
	struct val *r; 

	if (isstring (a) || isstring (b)) {
		to_string (a);
		to_string (b);	
		r = make_integer ((quad_t)(strcoll (a->u.s, b->u.s) == 0));
	} else {
#ifdef DEBUG_FOR_CONVERSIONS
		char buffer[2000];
		sprintf(buffer,"Converting '%s' and '%s' ", a->u.s, b->u.s);
#endif
		(void)to_integer(a);
		(void)to_integer(b);
#ifdef DEBUG_FOR_CONVERSIONS
		ast_log(LOG_WARNING,"%s to '%lld' and '%lld'\n", buffer, a->u.i, b->u.i);
#endif
		r = make_integer ((quad_t)(a->u.i == b->u.i));
	}

	free_value (a);
	free_value (b);
	return r;
}

static struct val *
op_gt (struct val *a, struct val *b)
{
	struct val *r;

	if (isstring (a) || isstring (b)) {
		to_string (a);
		to_string (b);
		r = make_integer ((quad_t)(strcoll (a->u.s, b->u.s) > 0));
	} else {
		(void)to_integer(a);
		(void)to_integer(b);
		r = make_integer ((quad_t)(a->u.i > b->u.i));
	}

	free_value (a);
	free_value (b);
	return r;
}

static struct val *
op_lt (struct val *a, struct val *b)
{
	struct val *r;

	if (isstring (a) || isstring (b)) {
		to_string (a);
		to_string (b);
		r = make_integer ((quad_t)(strcoll (a->u.s, b->u.s) < 0));
	} else {
		(void)to_integer(a);
		(void)to_integer(b);
		r = make_integer ((quad_t)(a->u.i < b->u.i));
	}

	free_value (a);
	free_value (b);
	return r;
}

static struct val *
op_ge (struct val *a, struct val *b)
{
	struct val *r;

	if (isstring (a) || isstring (b)) {
		to_string (a);
		to_string (b);
		r = make_integer ((quad_t)(strcoll (a->u.s, b->u.s) >= 0));
	} else {
		(void)to_integer(a);
		(void)to_integer(b);
		r = make_integer ((quad_t)(a->u.i >= b->u.i));
	}

	free_value (a);
	free_value (b);
	return r;
}

static struct val *
op_le (struct val *a, struct val *b)
{
	struct val *r;

	if (isstring (a) || isstring (b)) {
		to_string (a);
		to_string (b);
		r = make_integer ((quad_t)(strcoll (a->u.s, b->u.s) <= 0));
	} else {
		(void)to_integer(a);
		(void)to_integer(b);
		r = make_integer ((quad_t)(a->u.i <= b->u.i));
	}

	free_value (a);
	free_value (b);
	return r;
}

static struct val *
op_cond (struct val *a, struct val *b, struct val *c)
{
	struct val *r;

	if( isstring(a) )
	{
		if( strlen(a->u.s) && strcmp(a->u.s, "\"\"") != 0 && strcmp(a->u.s,"0") != 0 )
		{
			free_value(a);
			free_value(c);
			r = b;
		}
		else
		{
			free_value(a);
			free_value(b);
			r = c;
		}
	}
	else
	{
		(void)to_integer(a);
		if( a->u.i )
		{
			free_value(a);
			free_value(c);
			r = b;
		}
		else
		{
			free_value(a);
			free_value(b);
			r = c;
		}
	}
	return r;
}

static struct val *
op_ne (struct val *a, struct val *b)
{
	struct val *r;

	if (isstring (a) || isstring (b)) {
		to_string (a);
		to_string (b);
		r = make_integer ((quad_t)(strcoll (a->u.s, b->u.s) != 0));
	} else {
		(void)to_integer(a);
		(void)to_integer(b);
		r = make_integer ((quad_t)(a->u.i != b->u.i));
	}

	free_value (a);
	free_value (b);
	return r;
}

static int
chk_plus (quad_t a, quad_t b, quad_t r)
{
	/* sum of two positive numbers must be positive */
	if (a > 0 && b > 0 && r <= 0)
		return 1;
	/* sum of two negative numbers must be negative */
	if (a < 0 && b < 0 && r >= 0)
		return 1;
	/* all other cases are OK */
	return 0;
}

static struct val *
op_plus (struct val *a, struct val *b)
{
	struct val *r;

	if (!to_integer (a)) {
		if( !extra_error_message_supplied )
			ast_log(LOG_WARNING,"non-numeric argument\n");
		if (!to_integer (b)) {
			free_value(a);
			free_value(b);
			return make_integer(0);
		} else {
			free_value(a);
			return (b);
		}
	} else if (!to_integer(b)) {
		free_value(b);
		return (a);
	}

	r = make_integer (/*(quad_t)*/(a->u.i + b->u.i));
	if (chk_plus (a->u.i, b->u.i, r->u.i)) {
		ast_log(LOG_WARNING,"overflow\n");
	}
	free_value (a);
	free_value (b);
	return r;
}

static int
chk_minus (quad_t a, quad_t b, quad_t r)
{
	/* special case subtraction of QUAD_MIN */
	if (b == QUAD_MIN) {
		if (a >= 0)
			return 1;
		else
			return 0;
	}
	/* this is allowed for b != QUAD_MIN */
	return chk_plus (a, -b, r);
}

static struct val *
op_minus (struct val *a, struct val *b)
{
	struct val *r;

	if (!to_integer (a)) {
		if( !extra_error_message_supplied )
			ast_log(LOG_WARNING, "non-numeric argument\n");
		if (!to_integer (b)) {
			free_value(a);
			free_value(b);
			return make_integer(0);
		} else {
			r = make_integer(0 - b->u.i);
			free_value(a);
			free_value(b);
			return (r);
		}
	} else if (!to_integer(b)) {
		if( !extra_error_message_supplied )
			ast_log(LOG_WARNING, "non-numeric argument\n");
		free_value(b);
		return (a);
	}

	r = make_integer (/*(quad_t)*/(a->u.i - b->u.i));
	if (chk_minus (a->u.i, b->u.i, r->u.i)) {
		ast_log(LOG_WARNING, "overflow\n");
	}
	free_value (a);
	free_value (b);
	return r;
}

static struct val *
op_negate (struct val *a)
{
	struct val *r;

	if (!to_integer (a) ) {
		free_value(a);
		if( !extra_error_message_supplied )
			ast_log(LOG_WARNING, "non-numeric argument\n");
		return make_integer(0);
	}

	r = make_integer (/*(quad_t)*/(- a->u.i));
	if (chk_minus (0, a->u.i, r->u.i)) {
		ast_log(LOG_WARNING, "overflow\n");
	}
	free_value (a);
	return r;
}

static struct val *
op_compl (struct val *a)
{
	int v1 = 1;
	struct val *r;
	
	if( !a )
	{
		v1 = 0;
	}
	else
	{
		switch( a->type )
		{
		case AST_EXPR_integer:
			if( a->u.i == 0 )
				v1 = 0;
			break;
			
		case AST_EXPR_string:
			if( a->u.s == 0 )
				v1 = 0;
			else
			{
				if( a->u.s[0] == 0 )
					v1 = 0;
				else if (strlen(a->u.s) == 1 && a->u.s[0] == '0' )
					v1 = 0;
			}
			break;
			
		case AST_EXPR_numeric_string:
			if( a->u.s == 0 )
				v1 = 0;
			else
			{
				if( a->u.s[0] == 0 )
					v1 = 0;
				else if (strlen(a->u.s) == 1 && a->u.s[0] == '0' )
					v1 = 0;
			}
			break;
		}
	}
	
	r = make_integer (!v1);
	free_value (a);
	return r;
}

static int
chk_times (quad_t a, quad_t b, quad_t r)
{
	/* special case: first operand is 0, no overflow possible */
	if (a == 0)
		return 0;
	/* cerify that result of division matches second operand */
	if (r / a != b)
		return 1;
	return 0;
}

static struct val *
op_times (struct val *a, struct val *b)
{
	struct val *r;

	if (!to_integer (a) || !to_integer (b)) {
		free_value(a);
		free_value(b);
		if( !extra_error_message_supplied )
			ast_log(LOG_WARNING, "non-numeric argument\n");
		return(make_integer(0));
	}

	r = make_integer (/*(quad_t)*/(a->u.i * b->u.i));
	if (chk_times (a->u.i, b->u.i, r->u.i)) {
		ast_log(LOG_WARNING, "overflow\n");
	}
	free_value (a);
	free_value (b);
	return (r);
}

static int
chk_div (quad_t a, quad_t b)
{
	/* div by zero has been taken care of before */
	/* only QUAD_MIN / -1 causes overflow */
	if (a == QUAD_MIN && b == -1)
		return 1;
	/* everything else is OK */
	return 0;
}

static struct val *
op_div (struct val *a, struct val *b)
{
	struct val *r;

	if (!to_integer (a)) {
		free_value(a);
		free_value(b);
		if( !extra_error_message_supplied )
			ast_log(LOG_WARNING, "non-numeric argument\n");
		return make_integer(0);
	} else if (!to_integer (b)) {
		free_value(a);
		free_value(b);
		if( !extra_error_message_supplied )
			ast_log(LOG_WARNING, "non-numeric argument\n");
		return make_integer(INT_MAX);
	}

	if (b->u.i == 0) {
		ast_log(LOG_WARNING, "division by zero\n");		
		free_value(a);
		free_value(b);
		return make_integer(INT_MAX);
	}

	r = make_integer (/*(quad_t)*/(a->u.i / b->u.i));
	if (chk_div (a->u.i, b->u.i)) {
		ast_log(LOG_WARNING, "overflow\n");
	}
	free_value (a);
	free_value (b);
	return r;
}
	
static struct val *
op_rem (struct val *a, struct val *b)
{
	struct val *r;

	if (!to_integer (a) || !to_integer (b)) {
		if( !extra_error_message_supplied )
			ast_log(LOG_WARNING, "non-numeric argument\n");
		free_value(a);
		free_value(b);
		return make_integer(0);
	}

	if (b->u.i == 0) {
		ast_log(LOG_WARNING, "div by zero\n");
		free_value(a);
		return(b);
	}

	r = make_integer (/*(quad_t)*/(a->u.i % b->u.i));
	/* chk_rem necessary ??? */
	free_value (a);
	free_value (b);
	return r;
}
	

static struct val *
op_colon (struct val *a, struct val *b)
{
	regex_t rp;
	regmatch_t rm[2];
	char errbuf[256];
	int eval;
	struct val *v;

	/* coerce to both arguments to strings */
	to_string(a);
	to_string(b);
	/* strip double quotes from both -- they'll screw up the pattern, and the search string starting at ^ */
	strip_quotes(a);
	strip_quotes(b);
	/* compile regular expression */
	if ((eval = regcomp (&rp, b->u.s, REG_EXTENDED)) != 0) {
		regerror (eval, &rp, errbuf, sizeof(errbuf));
		ast_log(LOG_WARNING,"regcomp() error : %s",errbuf);
		free_value(a);
		free_value(b);
		return make_str("");		
	}

	/* compare string against pattern */
	/* remember that patterns are anchored to the beginning of the line */
	if (regexec(&rp, a->u.s, (size_t)2, rm, 0) == 0 && rm[0].rm_so == 0) {
		if (rm[1].rm_so >= 0) {
			*(a->u.s + rm[1].rm_eo) = '\0';
			v = make_str (a->u.s + rm[1].rm_so);

		} else {
			v = make_integer ((quad_t)(rm[0].rm_eo - rm[0].rm_so));
		}
	} else {
		if (rp.re_nsub == 0) {
			v = make_integer ((quad_t)0);
		} else {
			v = make_str ("");
		}
	}

	/* free arguments and pattern buffer */
	free_value (a);
	free_value (b);
	regfree (&rp);

	return v;
}
	

static struct val *
op_eqtilde (struct val *a, struct val *b)
{
	regex_t rp;
	regmatch_t rm[2];
	char errbuf[256];
	int eval;
	struct val *v;

	/* coerce to both arguments to strings */
	to_string(a);
	to_string(b);
	/* strip double quotes from both -- they'll screw up the pattern, and the search string starting at ^ */
	strip_quotes(a);
	strip_quotes(b);
	/* compile regular expression */
	if ((eval = regcomp (&rp, b->u.s, REG_EXTENDED)) != 0) {
		regerror (eval, &rp, errbuf, sizeof(errbuf));
		ast_log(LOG_WARNING,"regcomp() error : %s",errbuf);
		free_value(a);
		free_value(b);
		return make_str("");		
	}

	/* compare string against pattern */
	/* remember that patterns are anchored to the beginning of the line */
	if (regexec(&rp, a->u.s, (size_t)2, rm, 0) == 0 ) {
		if (rm[1].rm_so >= 0) {
			*(a->u.s + rm[1].rm_eo) = '\0';
			v = make_str (a->u.s + rm[1].rm_so);

		} else {
			v = make_integer ((quad_t)(rm[0].rm_eo - rm[0].rm_so));
		}
	} else {
		if (rp.re_nsub == 0) {
			v = make_integer ((quad_t)0);
		} else {
			v = make_str ("");
		}
	}

	/* free arguments and pattern buffer */
	free_value (a);
	free_value (b);
	regfree (&rp);

	return v;
}