637 lines
12 KiB
Plaintext
637 lines
12 KiB
Plaintext
%{
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/* Written by Pace Willisson (pace@blitz.com)
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* and placed in the public domain.
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*
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* Largely rewritten by J.T. Conklin (jtc@wimsey.com)
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*
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* $FreeBSD$
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*/
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#include <sys/types.h>
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#include <ctype.h>
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#include <err.h>
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#include <errno.h>
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#include <inttypes.h>
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#include <limits.h>
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#include <locale.h>
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#include <stdio.h>
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#include <stdlib.h>
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#include <string.h>
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#include <regex.h>
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#include <unistd.h>
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/*
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* POSIX specifies a specific error code for syntax errors. We exit
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* with this code for all errors.
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*/
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#define ERR_EXIT 2
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enum valtype {
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integer, numeric_string, string
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} ;
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struct val {
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enum valtype type;
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union {
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char *s;
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intmax_t i;
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} u;
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} ;
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struct val *result;
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int chk_div(intmax_t, intmax_t);
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int chk_minus(intmax_t, intmax_t, intmax_t);
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int chk_plus(intmax_t, intmax_t, intmax_t);
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int chk_times(intmax_t, intmax_t, intmax_t);
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void free_value(struct val *);
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int is_zero_or_null(struct val *);
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int isstring(struct val *);
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struct val *make_integer(intmax_t);
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struct val *make_str(const char *);
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struct val *op_and(struct val *, struct val *);
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struct val *op_colon(struct val *, struct val *);
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struct val *op_div(struct val *, struct val *);
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struct val *op_eq(struct val *, struct val *);
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struct val *op_ge(struct val *, struct val *);
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struct val *op_gt(struct val *, struct val *);
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struct val *op_le(struct val *, struct val *);
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struct val *op_lt(struct val *, struct val *);
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struct val *op_minus(struct val *, struct val *);
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struct val *op_ne(struct val *, struct val *);
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struct val *op_or(struct val *, struct val *);
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struct val *op_plus(struct val *, struct val *);
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struct val *op_rem(struct val *, struct val *);
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struct val *op_times(struct val *, struct val *);
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intmax_t to_integer(struct val *);
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void to_string(struct val *);
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int yyerror(const char *);
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int yylex(void);
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int yyparse(void);
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char **av;
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%}
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%union
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{
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struct val *val;
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}
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%left <val> '|'
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%left <val> '&'
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%left <val> '=' '>' '<' GE LE NE
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%left <val> '+' '-'
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%left <val> '*' '/' '%'
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%left <val> ':'
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%token <val> TOKEN
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%type <val> start expr
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%%
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start: expr { result = $$; }
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expr: TOKEN
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| '(' expr ')' { $$ = $2; }
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| expr '|' expr { $$ = op_or ($1, $3); }
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| expr '&' expr { $$ = op_and ($1, $3); }
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| expr '=' expr { $$ = op_eq ($1, $3); }
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| expr '>' expr { $$ = op_gt ($1, $3); }
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| expr '<' expr { $$ = op_lt ($1, $3); }
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| expr GE expr { $$ = op_ge ($1, $3); }
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| expr LE expr { $$ = op_le ($1, $3); }
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| expr NE expr { $$ = op_ne ($1, $3); }
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| expr '+' expr { $$ = op_plus ($1, $3); }
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| expr '-' expr { $$ = op_minus ($1, $3); }
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| expr '*' expr { $$ = op_times ($1, $3); }
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| expr '/' expr { $$ = op_div ($1, $3); }
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| expr '%' expr { $$ = op_rem ($1, $3); }
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| expr ':' expr { $$ = op_colon ($1, $3); }
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;
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%%
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struct val *
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make_integer(intmax_t i)
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{
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struct val *vp;
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vp = (struct val *) malloc (sizeof (*vp));
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if (vp == NULL) {
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errx(ERR_EXIT, "malloc() failed");
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}
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vp->type = integer;
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vp->u.i = i;
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return vp;
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}
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struct val *
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make_str(const char *s)
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{
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struct val *vp;
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char *ep;
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vp = (struct val *) malloc (sizeof (*vp));
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if (vp == NULL || ((vp->u.s = strdup (s)) == NULL)) {
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errx(ERR_EXIT, "malloc() failed");
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}
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/*
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* Previously we tried to scan the string to see if it ``looked like''
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* an integer (erroneously, as it happened). Let strtoimax() do the
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* dirty work. We could cache the value, except that we are using
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* a union and need to preserve the original string form until we
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* are certain that it is not needed.
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*
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* IEEE Std.1003.1-2001 says:
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* /integer/ An argument consisting only of an (optional) unary minus
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* followed by digits.
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*
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* This means that arguments which consist of digits followed by
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* non-digits MUST NOT be considered integers. strtoimax() will
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* figure this out for us.
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*/
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(void)strtoimax(s, &ep, 10);
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if (*ep != '\0')
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vp->type = string;
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else
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vp->type = numeric_string;
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return vp;
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}
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void
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free_value(struct val *vp)
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{
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if (vp->type == string || vp->type == numeric_string)
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free (vp->u.s);
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}
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intmax_t
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to_integer(struct val *vp)
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{
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intmax_t i;
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if (vp->type == integer)
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return 1;
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if (vp->type == string)
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return 0;
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/* vp->type == numeric_string, make it numeric */
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errno = 0;
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i = strtoimax(vp->u.s, (char **)NULL, 10);
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if (errno == ERANGE)
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err(ERR_EXIT, NULL);
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free (vp->u.s);
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vp->u.i = i;
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vp->type = integer;
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return 1;
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}
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void
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to_string(struct val *vp)
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{
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char *tmp;
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if (vp->type == string || vp->type == numeric_string)
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return;
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/*
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* log_10(x) ~= 0.3 * log_2(x). Rounding up gives the number
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* of digits; add one each for the sign and terminating null
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* character, respectively.
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*/
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#define NDIGITS(x) (3 * (sizeof(x) * CHAR_BIT) / 10 + 1 + 1 + 1)
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tmp = malloc(NDIGITS(vp->u.i));
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if (tmp == NULL)
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errx(ERR_EXIT, "malloc() failed");
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sprintf(tmp, "%jd", vp->u.i);
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vp->type = string;
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vp->u.s = tmp;
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}
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int
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isstring(struct val *vp)
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{
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/* only TRUE if this string is not a valid integer */
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return (vp->type == string);
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}
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int
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yylex(void)
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{
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char *p;
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if (*av == NULL)
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return (0);
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p = *av++;
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if (strlen (p) == 1) {
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if (strchr ("|&=<>+-*/%:()", *p))
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return (*p);
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} else if (strlen (p) == 2 && p[1] == '=') {
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switch (*p) {
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case '>': return (GE);
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case '<': return (LE);
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case '!': return (NE);
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}
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}
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yylval.val = make_str (p);
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return (TOKEN);
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}
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int
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is_zero_or_null(struct val *vp)
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{
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if (vp->type == integer) {
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return (vp->u.i == 0);
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} else {
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return (*vp->u.s == 0 || (to_integer (vp) && vp->u.i == 0));
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}
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/* NOTREACHED */
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}
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int
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main(int argc, char *argv[])
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{
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int c;
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setlocale (LC_ALL, "");
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if (getenv("EXPR_COMPAT") != NULL) {
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av = argv + 1;
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} else {
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while ((c = getopt(argc, argv, "")) != -1)
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switch (c) {
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default:
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fprintf(stderr,"usage: expr [--] expression\n");
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exit(ERR_EXIT);
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}
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av = argv + optind;
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}
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yyparse();
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if (result->type == integer)
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printf("%jd\n", result->u.i);
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else
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printf("%s\n", result->u.s);
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return (is_zero_or_null(result));
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}
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int
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yyerror(const char *s __unused)
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{
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errx(ERR_EXIT, "syntax error");
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}
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struct val *
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op_or(struct val *a, struct val *b)
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{
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if (is_zero_or_null (a)) {
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free_value (a);
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return (b);
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} else {
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free_value (b);
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return (a);
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}
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}
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struct val *
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op_and(struct val *a, struct val *b)
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{
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if (is_zero_or_null (a) || is_zero_or_null (b)) {
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free_value (a);
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free_value (b);
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return (make_integer ((intmax_t)0));
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} else {
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free_value (b);
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return (a);
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}
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}
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struct val *
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op_eq(struct val *a, struct val *b)
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{
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struct val *r;
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if (isstring (a) || isstring (b)) {
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to_string (a);
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to_string (b);
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r = make_integer ((intmax_t)(strcoll (a->u.s, b->u.s) == 0));
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} else {
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(void)to_integer(a);
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(void)to_integer(b);
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r = make_integer ((intmax_t)(a->u.i == b->u.i));
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}
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free_value (a);
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free_value (b);
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return r;
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}
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struct val *
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op_gt(struct val *a, struct val *b)
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{
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struct val *r;
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if (isstring (a) || isstring (b)) {
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to_string (a);
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to_string (b);
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r = make_integer ((intmax_t)(strcoll (a->u.s, b->u.s) > 0));
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} else {
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(void)to_integer(a);
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(void)to_integer(b);
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r = make_integer ((intmax_t)(a->u.i > b->u.i));
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}
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free_value (a);
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free_value (b);
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return r;
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}
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struct val *
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op_lt(struct val *a, struct val *b)
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{
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struct val *r;
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if (isstring (a) || isstring (b)) {
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to_string (a);
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to_string (b);
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r = make_integer ((intmax_t)(strcoll (a->u.s, b->u.s) < 0));
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} else {
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(void)to_integer(a);
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(void)to_integer(b);
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r = make_integer ((intmax_t)(a->u.i < b->u.i));
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}
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free_value (a);
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free_value (b);
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return r;
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}
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struct val *
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op_ge(struct val *a, struct val *b)
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{
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struct val *r;
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if (isstring (a) || isstring (b)) {
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to_string (a);
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to_string (b);
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r = make_integer ((intmax_t)(strcoll (a->u.s, b->u.s) >= 0));
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} else {
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(void)to_integer(a);
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(void)to_integer(b);
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r = make_integer ((intmax_t)(a->u.i >= b->u.i));
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}
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free_value (a);
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free_value (b);
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return r;
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}
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struct val *
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op_le(struct val *a, struct val *b)
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{
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struct val *r;
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if (isstring (a) || isstring (b)) {
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to_string (a);
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to_string (b);
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r = make_integer ((intmax_t)(strcoll (a->u.s, b->u.s) <= 0));
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} else {
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(void)to_integer(a);
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(void)to_integer(b);
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r = make_integer ((intmax_t)(a->u.i <= b->u.i));
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}
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free_value (a);
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free_value (b);
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return r;
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}
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struct val *
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op_ne(struct val *a, struct val *b)
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{
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struct val *r;
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if (isstring (a) || isstring (b)) {
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to_string (a);
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to_string (b);
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r = make_integer ((intmax_t)(strcoll (a->u.s, b->u.s) != 0));
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} else {
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(void)to_integer(a);
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(void)to_integer(b);
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r = make_integer ((intmax_t)(a->u.i != b->u.i));
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}
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free_value (a);
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free_value (b);
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return r;
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}
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int
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chk_plus(intmax_t a, intmax_t b, intmax_t r)
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{
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/* sum of two positive numbers must be positive */
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if (a > 0 && b > 0 && r <= 0)
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return 1;
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/* sum of two negative numbers must be negative */
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if (a < 0 && b < 0 && r >= 0)
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return 1;
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/* all other cases are OK */
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return 0;
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}
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struct val *
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op_plus(struct val *a, struct val *b)
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{
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struct val *r;
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if (!to_integer (a) || !to_integer (b)) {
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errx(ERR_EXIT, "non-numeric argument");
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}
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r = make_integer (/*(intmax_t)*/(a->u.i + b->u.i));
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if (chk_plus (a->u.i, b->u.i, r->u.i)) {
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errx(ERR_EXIT, "overflow");
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}
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free_value (a);
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free_value (b);
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return r;
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}
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int
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chk_minus(intmax_t a, intmax_t b, intmax_t r)
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{
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/* special case subtraction of INTMAX_MIN */
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if (b == INTMAX_MIN) {
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if (a >= 0)
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return 1;
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else
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return 0;
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}
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/* this is allowed for b != INTMAX_MIN */
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return chk_plus (a, -b, r);
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}
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struct val *
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op_minus(struct val *a, struct val *b)
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{
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struct val *r;
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if (!to_integer (a) || !to_integer (b)) {
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errx(ERR_EXIT, "non-numeric argument");
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}
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r = make_integer (/*(intmax_t)*/(a->u.i - b->u.i));
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if (chk_minus (a->u.i, b->u.i, r->u.i)) {
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errx(ERR_EXIT, "overflow");
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}
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free_value (a);
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free_value (b);
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return r;
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}
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int
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chk_times(intmax_t a, intmax_t b, intmax_t r)
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{
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/* special case: first operand is 0, no overflow possible */
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if (a == 0)
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return 0;
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/* cerify that result of division matches second operand */
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if (r / a != b)
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return 1;
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return 0;
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}
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struct val *
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op_times(struct val *a, struct val *b)
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{
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struct val *r;
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if (!to_integer (a) || !to_integer (b)) {
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errx(ERR_EXIT, "non-numeric argument");
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}
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r = make_integer (/*(intmax_t)*/(a->u.i * b->u.i));
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if (chk_times (a->u.i, b->u.i, r->u.i)) {
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errx(ERR_EXIT, "overflow");
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}
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free_value (a);
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free_value (b);
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return (r);
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}
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int
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chk_div(intmax_t a, intmax_t b)
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{
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/* div by zero has been taken care of before */
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/* only INTMAX_MIN / -1 causes overflow */
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if (a == INTMAX_MIN && b == -1)
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return 1;
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/* everything else is OK */
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return 0;
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}
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struct val *
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op_div(struct val *a, struct val *b)
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{
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struct val *r;
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if (!to_integer (a) || !to_integer (b)) {
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errx(ERR_EXIT, "non-numeric argument");
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}
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if (b->u.i == 0) {
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errx(ERR_EXIT, "division by zero");
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}
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r = make_integer (/*(intmax_t)*/(a->u.i / b->u.i));
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if (chk_div (a->u.i, b->u.i)) {
|
|
errx(ERR_EXIT, "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(ERR_EXIT, "non-numeric argument");
|
|
}
|
|
|
|
if (b->u.i == 0) {
|
|
errx(ERR_EXIT, "division by zero");
|
|
}
|
|
|
|
r = make_integer (/*(intmax_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(ERR_EXIT, "%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 ((intmax_t)(rm[0].rm_eo - rm[0].rm_so));
|
|
}
|
|
} else {
|
|
if (rp.re_nsub == 0) {
|
|
v = make_integer ((intmax_t)0);
|
|
} else {
|
|
v = make_str ("");
|
|
}
|
|
}
|
|
|
|
/* free arguments and pattern buffer */
|
|
free_value (a);
|
|
free_value (b);
|
|
regfree (&rp);
|
|
|
|
return v;
|
|
}
|