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freebsd-skq/bin/expr/expr.y
Warner Losh 7669d0fc4f o __P has been reoved 
o Old-style K&R declarations have been converted to new C89 style
o register has been removed
o prototype for main() has been removed (gcc3 makes it an error)
o int main(int argc, char *argv[]) is the preferred main definition.
o Attempt to not break style(9) conformance for declarations more than
  they already are.
o gc some #ifdef sun ... #endif code

Approved by: arch@, new style(9)
2002-02-02 06:36:49 +00:00

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%{
/* Written by Pace Willisson (pace@blitz.com)
* and placed in the public domain.
*
* Largely rewritten by J.T. Conklin (jtc@wimsey.com)
*
* $FreeBSD$
*/
#include <sys/types.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <locale.h>
#include <ctype.h>
#include <err.h>
#include <errno.h>
#include <regex.h>
#include <limits.h>
enum valtype {
integer, numeric_string, string
} ;
struct val {
enum valtype type;
union {
char *s;
quad_t i;
} u;
} ;
struct val *result;
int chk_div(quad_t, quad_t);
int chk_minus(quad_t, quad_t, quad_t);
int chk_plus(quad_t, quad_t, quad_t);
int chk_times(quad_t, quad_t, quad_t);
void free_value(struct val *);
int is_zero_or_null(struct val *);
int isstring(struct val *);
struct val *make_integer(quad_t);
struct val *make_str(const char *);
struct val *op_and(struct val *, struct val *);
struct val *op_colon(struct val *, struct val *);
struct val *op_div(struct val *, struct val *);
struct val *op_eq(struct val *, struct val *);
struct val *op_ge(struct val *, struct val *);
struct val *op_gt(struct val *, struct val *);
struct val *op_le(struct val *, struct val *);
struct val *op_lt(struct val *, struct val *);
struct val *op_minus(struct val *, struct val *);
struct val *op_ne(struct val *, struct val *);
struct val *op_or(struct val *, struct val *);
struct val *op_plus(struct val *, struct val *);
struct val *op_rem(struct val *, struct val *);
struct val *op_times(struct val *, struct val *);
quad_t to_integer(struct val *);
void to_string(struct val *);
int yyerror(const char *);
int yylex(void);
int yyparse(void);
char **av;
%}
%union
{
struct val *val;
}
%left <val> '|'
%left <val> '&'
%left <val> '=' '>' '<' GE LE NE
%left <val> '+' '-'
%left <val> '*' '/' '%'
%left <val> ':'
%token <val> TOKEN
%type <val> start expr
%%
start: expr { result = $$; }
expr: TOKEN
| '(' expr ')' { $$ = $2; }
| expr '|' expr { $$ = op_or ($1, $3); }
| expr '&' expr { $$ = op_and ($1, $3); }
| expr '=' expr { $$ = op_eq ($1, $3); }
| expr '>' expr { $$ = op_gt ($1, $3); }
| expr '<' expr { $$ = op_lt ($1, $3); }
| expr GE expr { $$ = op_ge ($1, $3); }
| expr LE expr { $$ = op_le ($1, $3); }
| expr NE expr { $$ = op_ne ($1, $3); }
| expr '+' expr { $$ = op_plus ($1, $3); }
| expr '-' expr { $$ = op_minus ($1, $3); }
| expr '*' expr { $$ = op_times ($1, $3); }
| expr '/' expr { $$ = op_div ($1, $3); }
| expr '%' expr { $$ = op_rem ($1, $3); }
| expr ':' expr { $$ = op_colon ($1, $3); }
;
%%
struct val *
make_integer(quad_t i)
{
struct val *vp;
vp = (struct val *) malloc (sizeof (*vp));
if (vp == NULL) {
errx (2, "malloc() failed");
}
vp->type = integer;
vp->u.i = i;
return vp;
}
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)) {
errx (2, "malloc() failed");
}
for(i = 1, isint = isdigit(s[0]) || s[0] == '-';
isint && i < strlen(s);
i++)
{
if(!isdigit(s[i]))
isint = 0;
}
if (isint)
vp->type = numeric_string;
else
vp->type = string;
return vp;
}
void
free_value(struct val *vp)
{
if (vp->type == string || vp->type == numeric_string)
free (vp->u.s);
}
quad_t
to_integer(struct val *vp)
{
quad_t i;
if (vp->type == integer)
return 1;
if (vp->type == string)
return 0;
/* vp->type == numeric_string, make it numeric */
errno = 0;
i = strtoq(vp->u.s, (char**)NULL, 10);
if (errno != 0) {
errx (2, "overflow");
}
free (vp->u.s);
vp->u.i = i;
vp->type = integer;
return 1;
}
void
to_string(struct val *vp)
{
char *tmp;
if (vp->type == string || vp->type == numeric_string)
return;
tmp = malloc ((size_t)25);
if (tmp == NULL) {
errx (2, "malloc() failed");
}
sprintf (tmp, "%lld", (long long)vp->u.i);
vp->type = string;
vp->u.s = tmp;
}
int
isstring(struct val *vp)
{
/* only TRUE if this string is not a valid integer */
return (vp->type == string);
}
int
yylex(void)
{
char *p;
if (*av == NULL)
return (0);
p = *av++;
if (strlen (p) == 1) {
if (strchr ("|&=<>+-*/%:()", *p))
return (*p);
} else if (strlen (p) == 2 && p[1] == '=') {
switch (*p) {
case '>': return (GE);
case '<': return (LE);
case '!': return (NE);
}
}
yylval.val = make_str (p);
return (TOKEN);
}
int
is_zero_or_null(struct val *vp)
{
if (vp->type == integer) {
return (vp->u.i == 0);
} else {
return (*vp->u.s == 0 || (to_integer (vp) && vp->u.i == 0));
}
/* NOTREACHED */
}
int
main(int argc __unused, char *argv[])
{
setlocale (LC_ALL, "");
av = argv + 1;
yyparse ();
if (result->type == integer)
printf ("%lld\n", (long long)result->u.i);
else
printf ("%s\n", result->u.s);
return (is_zero_or_null (result));
}
int
yyerror(const char *s __unused)
{
errx (2, "syntax error");
}
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);
}
}
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);
}
}
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 {
(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;
}
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;
}
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;
}
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;
}
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;
}
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;
}
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;
}
struct val *
op_plus(struct val *a, struct val *b)
{
struct val *r;
if (!to_integer (a) || !to_integer (b)) {
errx (2, "non-numeric argument");
}
r = make_integer (/*(quad_t)*/(a->u.i + b->u.i));
if (chk_plus (a->u.i, b->u.i, r->u.i)) {
errx (2, "overflow");
}
free_value (a);
free_value (b);
return r;
}
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);
}
struct val *
op_minus(struct val *a, struct val *b)
{
struct val *r;
if (!to_integer (a) || !to_integer (b)) {
errx (2, "non-numeric argument");
}
r = make_integer (/*(quad_t)*/(a->u.i - b->u.i));
if (chk_minus (a->u.i, b->u.i, r->u.i)) {
errx (2, "overflow");
}
free_value (a);
free_value (b);
return r;
}
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;
}
struct val *
op_times(struct val *a, struct val *b)
{
struct val *r;
if (!to_integer (a) || !to_integer (b)) {
errx (2, "non-numeric argument");
}
r = make_integer (/*(quad_t)*/(a->u.i * b->u.i));
if (chk_times (a->u.i, b->u.i, r->u.i)) {
errx (2, "overflow");
}
free_value (a);
free_value (b);
return (r);
}
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;
}
struct val *
op_div(struct val *a, struct val *b)
{
struct val *r;
if (!to_integer (a) || !to_integer (b)) {
errx (2, "non-numeric argument");
}
if (b->u.i == 0) {
errx (2, "division by zero");
}
r = make_integer (/*(quad_t)*/(a->u.i / b->u.i));
if (chk_div (a->u.i, b->u.i)) {
errx (2, "overflow");
}
free_value (a);
free_value (b);
return r;
}
struct val *
op_rem(struct val *a, struct val *b)
{
struct val *r;
if (!to_integer (a) || !to_integer (b)) {
errx (2, "non-numeric argument");
}
if (b->u.i == 0) {
errx (2, "division by zero");
}
r = make_integer (/*(quad_t)*/(a->u.i % b->u.i));
/* chk_rem necessary ??? */
free_value (a);
free_value (b);
return r;
}
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);
/* compile regular expression */
if ((eval = regcomp (&rp, b->u.s, 0)) != 0) {
regerror (eval, &rp, errbuf, sizeof(errbuf));
errx (2, "%s", errbuf);
}
/* 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;
}
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