460 lines
10 KiB
Plaintext
460 lines
10 KiB
Plaintext
/* $NetBSD: expr.y,v 1.38 2012/03/15 02:02:20 joerg Exp $ */
|
|
|
|
/*_
|
|
* Copyright (c) 2000 The NetBSD Foundation, Inc.
|
|
* All rights reserved.
|
|
*
|
|
* This code is derived from software contributed to The NetBSD Foundation
|
|
* by Jaromir Dolecek <jdolecek@NetBSD.org> and J.T. Conklin <jtc@NetBSD.org>.
|
|
*
|
|
* Redistribution and use in source and binary forms, with or without
|
|
* modification, are permitted provided that the following conditions
|
|
* are met:
|
|
* 1. Redistributions of source code must retain the above copyright
|
|
* notice, this list of conditions and the following disclaimer.
|
|
* 2. Redistributions in binary form must reproduce the above copyright
|
|
* notice, this list of conditions and the following disclaimer in the
|
|
* documentation and/or other materials provided with the distribution.
|
|
*
|
|
* THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
|
|
* ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
|
|
* TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
|
|
* PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
|
|
* BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
|
|
* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
|
|
* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
|
|
* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
|
|
* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
|
|
* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
|
|
* POSSIBILITY OF SUCH DAMAGE.
|
|
*/
|
|
|
|
%{
|
|
#include <sys/cdefs.h>
|
|
#ifndef lint
|
|
__RCSID("$NetBSD: expr.y,v 1.38 2012/03/15 02:02:20 joerg Exp $");
|
|
#endif /* not lint */
|
|
|
|
#include <sys/types.h>
|
|
|
|
#include <err.h>
|
|
#include <errno.h>
|
|
#include <limits.h>
|
|
#include <locale.h>
|
|
#include <regex.h>
|
|
#include <stdarg.h>
|
|
#include <stdio.h>
|
|
#include <stdlib.h>
|
|
#include <string.h>
|
|
|
|
static const char * const *av;
|
|
|
|
static void yyerror(const char *, ...) __dead;
|
|
static int yylex(void);
|
|
static int is_zero_or_null(const char *);
|
|
static int is_integer(const char *);
|
|
static int64_t perform_arith_op(const char *, const char *, const char *);
|
|
|
|
int main(int, const char * const *);
|
|
|
|
#define YYSTYPE const char *
|
|
|
|
%}
|
|
%token STRING
|
|
%left SPEC_OR
|
|
%left SPEC_AND
|
|
%left COMPARE
|
|
%left ADD_SUB_OPERATOR
|
|
%left MUL_DIV_MOD_OPERATOR
|
|
%left SPEC_REG
|
|
%left LENGTH
|
|
%left LEFT_PARENT RIGHT_PARENT
|
|
|
|
%%
|
|
|
|
exp: expr = {
|
|
(void) printf("%s\n", $1);
|
|
return (is_zero_or_null($1));
|
|
}
|
|
;
|
|
|
|
expr: item { $$ = $1; }
|
|
| expr SPEC_OR expr = {
|
|
/*
|
|
* Return evaluation of first expression if it is neither
|
|
* an empty string nor zero; otherwise, returns the evaluation
|
|
* of second expression.
|
|
*/
|
|
if (!is_zero_or_null($1))
|
|
$$ = $1;
|
|
else
|
|
$$ = $3;
|
|
}
|
|
| expr SPEC_AND expr = {
|
|
/*
|
|
* Returns the evaluation of first expr if neither expression
|
|
* evaluates to an empty string or zero; otherwise, returns
|
|
* zero.
|
|
*/
|
|
if (!is_zero_or_null($1) && !is_zero_or_null($3))
|
|
$$ = $1;
|
|
else
|
|
$$ = "0";
|
|
}
|
|
| expr SPEC_REG expr = {
|
|
/*
|
|
* The ``:'' operator matches first expr against the second,
|
|
* which must be a regular expression.
|
|
*/
|
|
regex_t rp;
|
|
regmatch_t rm[2];
|
|
int eval;
|
|
|
|
/* compile regular expression */
|
|
if ((eval = regcomp(&rp, $3, REG_BASIC)) != 0) {
|
|
char errbuf[256];
|
|
(void)regerror(eval, &rp, errbuf, sizeof(errbuf));
|
|
yyerror("%s", errbuf);
|
|
/* NOT REACHED */
|
|
}
|
|
|
|
/* compare string against pattern -- remember that patterns
|
|
are anchored to the beginning of the line */
|
|
if (regexec(&rp, $1, 2, rm, 0) == 0 && rm[0].rm_so == 0) {
|
|
char *val;
|
|
if (rm[1].rm_so >= 0) {
|
|
(void) asprintf(&val, "%.*s",
|
|
(int) (rm[1].rm_eo - rm[1].rm_so),
|
|
$1 + rm[1].rm_so);
|
|
} else {
|
|
(void) asprintf(&val, "%d",
|
|
(int)(rm[0].rm_eo - rm[0].rm_so));
|
|
}
|
|
if (val == NULL)
|
|
err(1, NULL);
|
|
$$ = val;
|
|
} else {
|
|
if (rp.re_nsub == 0) {
|
|
$$ = "0";
|
|
} else {
|
|
$$ = "";
|
|
}
|
|
}
|
|
|
|
}
|
|
| expr ADD_SUB_OPERATOR expr = {
|
|
/* Returns the results of addition, subtraction */
|
|
char *val;
|
|
int64_t res;
|
|
|
|
res = perform_arith_op($1, $2, $3);
|
|
(void) asprintf(&val, "%lld", (long long int) res);
|
|
if (val == NULL)
|
|
err(1, NULL);
|
|
$$ = val;
|
|
}
|
|
|
|
| expr MUL_DIV_MOD_OPERATOR expr = {
|
|
/*
|
|
* Returns the results of multiply, divide or remainder of
|
|
* numeric-valued arguments.
|
|
*/
|
|
char *val;
|
|
int64_t res;
|
|
|
|
res = perform_arith_op($1, $2, $3);
|
|
(void) asprintf(&val, "%lld", (long long int) res);
|
|
if (val == NULL)
|
|
err(1, NULL);
|
|
$$ = val;
|
|
|
|
}
|
|
| expr COMPARE expr = {
|
|
/*
|
|
* Returns the results of integer comparison if both arguments
|
|
* are integers; otherwise, returns the results of string
|
|
* comparison using the locale-specific collation sequence.
|
|
* The result of each comparison is 1 if the specified relation
|
|
* is true, or 0 if the relation is false.
|
|
*/
|
|
|
|
int64_t l, r;
|
|
int res;
|
|
|
|
res = 0;
|
|
|
|
/*
|
|
* Slight hack to avoid differences in the compare code
|
|
* between string and numeric compare.
|
|
*/
|
|
if (is_integer($1) && is_integer($3)) {
|
|
/* numeric comparison */
|
|
l = strtoll($1, NULL, 10);
|
|
r = strtoll($3, NULL, 10);
|
|
} else {
|
|
/* string comparison */
|
|
l = strcoll($1, $3);
|
|
r = 0;
|
|
}
|
|
|
|
switch($2[0]) {
|
|
case '=': /* equal */
|
|
res = (l == r);
|
|
break;
|
|
case '>': /* greater or greater-equal */
|
|
if ($2[1] == '=')
|
|
res = (l >= r);
|
|
else
|
|
res = (l > r);
|
|
break;
|
|
case '<': /* lower or lower-equal */
|
|
if ($2[1] == '=')
|
|
res = (l <= r);
|
|
else
|
|
res = (l < r);
|
|
break;
|
|
case '!': /* not equal */
|
|
/* the check if this is != was done in yylex() */
|
|
res = (l != r);
|
|
}
|
|
|
|
$$ = (res) ? "1" : "0";
|
|
|
|
}
|
|
| LEFT_PARENT expr RIGHT_PARENT { $$ = $2; }
|
|
| LENGTH expr {
|
|
/*
|
|
* Return length of 'expr' in bytes.
|
|
*/
|
|
char *ln;
|
|
|
|
asprintf(&ln, "%ld", (long) strlen($2));
|
|
if (ln == NULL)
|
|
err(1, NULL);
|
|
$$ = ln;
|
|
}
|
|
;
|
|
|
|
item: STRING
|
|
| ADD_SUB_OPERATOR
|
|
| MUL_DIV_MOD_OPERATOR
|
|
| COMPARE
|
|
| SPEC_OR
|
|
| SPEC_AND
|
|
| SPEC_REG
|
|
| LENGTH
|
|
;
|
|
%%
|
|
|
|
/*
|
|
* Returns 1 if the string is empty or contains only numeric zero.
|
|
*/
|
|
static int
|
|
is_zero_or_null(const char *str)
|
|
{
|
|
char *endptr;
|
|
|
|
return str[0] == '\0'
|
|
|| ( strtoll(str, &endptr, 10) == 0LL
|
|
&& endptr[0] == '\0');
|
|
}
|
|
|
|
/*
|
|
* Returns 1 if the string is an integer.
|
|
*/
|
|
static int
|
|
is_integer(const char *str)
|
|
{
|
|
char *endptr;
|
|
|
|
(void) strtoll(str, &endptr, 10);
|
|
/* note we treat empty string as valid number */
|
|
return (endptr[0] == '\0');
|
|
}
|
|
|
|
static int64_t
|
|
perform_arith_op(const char *left, const char *op, const char *right)
|
|
{
|
|
int64_t res, sign, l, r;
|
|
u_int64_t temp;
|
|
|
|
res = 0;
|
|
|
|
if (!is_integer(left)) {
|
|
yyerror("non-integer argument '%s'", left);
|
|
/* NOTREACHED */
|
|
}
|
|
if (!is_integer(right)) {
|
|
yyerror("non-integer argument '%s'", right);
|
|
/* NOTREACHED */
|
|
}
|
|
|
|
errno = 0;
|
|
l = strtoll(left, NULL, 10);
|
|
if (errno == ERANGE) {
|
|
yyerror("value '%s' is %s is %lld", left,
|
|
(l > 0) ? "too big, maximum" : "too small, minimum",
|
|
(l > 0) ? LLONG_MAX : LLONG_MIN);
|
|
/* NOTREACHED */
|
|
}
|
|
|
|
errno = 0;
|
|
r = strtoll(right, NULL, 10);
|
|
if (errno == ERANGE) {
|
|
yyerror("value '%s' is %s is %lld", right,
|
|
(l > 0) ? "too big, maximum" : "too small, minimum",
|
|
(l > 0) ? LLONG_MAX : LLONG_MIN);
|
|
/* NOTREACHED */
|
|
}
|
|
|
|
switch(op[0]) {
|
|
case '+':
|
|
/*
|
|
* Do the op into an unsigned to avoid overflow and then cast
|
|
* back to check the resulting signage.
|
|
*/
|
|
temp = l + r;
|
|
res = (int64_t) temp;
|
|
/* very simplistic check for over-& underflow */
|
|
if ((res < 0 && l > 0 && r > 0)
|
|
|| (res > 0 && l < 0 && r < 0))
|
|
yyerror("integer overflow or underflow occurred for "
|
|
"operation '%s %s %s'", left, op, right);
|
|
break;
|
|
case '-':
|
|
/*
|
|
* Do the op into an unsigned to avoid overflow and then cast
|
|
* back to check the resulting signage.
|
|
*/
|
|
temp = l - r;
|
|
res = (int64_t) temp;
|
|
/* very simplistic check for over-& underflow */
|
|
if ((res < 0 && l > 0 && l > r)
|
|
|| (res > 0 && l < 0 && l < r) )
|
|
yyerror("integer overflow or underflow occurred for "
|
|
"operation '%s %s %s'", left, op, right);
|
|
break;
|
|
case '/':
|
|
if (r == 0)
|
|
yyerror("second argument to '%s' must not be zero", op);
|
|
res = l / r;
|
|
|
|
break;
|
|
case '%':
|
|
if (r == 0)
|
|
yyerror("second argument to '%s' must not be zero", op);
|
|
res = l % r;
|
|
break;
|
|
case '*':
|
|
/* shortcut */
|
|
if ((l == 0) || (r == 0)) {
|
|
res = 0;
|
|
break;
|
|
}
|
|
|
|
sign = 1;
|
|
if (l < 0)
|
|
sign *= -1;
|
|
if (r < 0)
|
|
sign *= -1;
|
|
|
|
res = l * r;
|
|
/*
|
|
* XXX: not the most portable but works on anything with 2's
|
|
* complement arithmetic. If the signs don't match or the
|
|
* result was 0 on 2's complement this overflowed.
|
|
*/
|
|
if ((res < 0 && sign > 0) || (res > 0 && sign < 0) ||
|
|
(res == 0))
|
|
yyerror("integer overflow or underflow occurred for "
|
|
"operation '%s %s %s'", left, op, right);
|
|
/* NOTREACHED */
|
|
break;
|
|
}
|
|
return res;
|
|
}
|
|
|
|
static const char *x = "|&=<>+-*/%:()";
|
|
static const int x_token[] = {
|
|
SPEC_OR, SPEC_AND, COMPARE, COMPARE, COMPARE, ADD_SUB_OPERATOR,
|
|
ADD_SUB_OPERATOR, MUL_DIV_MOD_OPERATOR, MUL_DIV_MOD_OPERATOR,
|
|
MUL_DIV_MOD_OPERATOR, SPEC_REG, LEFT_PARENT, RIGHT_PARENT
|
|
};
|
|
|
|
static int handle_ddash = 1;
|
|
|
|
int
|
|
yylex(void)
|
|
{
|
|
const char *p = *av++;
|
|
int retval;
|
|
|
|
if (!p)
|
|
retval = 0;
|
|
else if (p[1] == '\0') {
|
|
const char *w = strchr(x, p[0]);
|
|
if (w) {
|
|
retval = x_token[w-x];
|
|
} else {
|
|
retval = STRING;
|
|
}
|
|
} else if (p[1] == '=' && p[2] == '\0'
|
|
&& (p[0] == '>' || p[0] == '<' || p[0] == '!'))
|
|
retval = COMPARE;
|
|
else if (handle_ddash && p[0] == '-' && p[1] == '-' && p[2] == '\0') {
|
|
/* ignore "--" if passed as first argument and isn't followed
|
|
* by another STRING */
|
|
retval = yylex();
|
|
if (retval != STRING && retval != LEFT_PARENT
|
|
&& retval != RIGHT_PARENT) {
|
|
/* is not followed by string or parenthesis, use as
|
|
* STRING */
|
|
retval = STRING;
|
|
av--; /* was increased in call to yylex() above */
|
|
p = "--";
|
|
} else {
|
|
/* "--" is to be ignored */
|
|
p = yylval;
|
|
}
|
|
} else if (strcmp(p, "length") == 0)
|
|
retval = LENGTH;
|
|
else
|
|
retval = STRING;
|
|
|
|
handle_ddash = 0;
|
|
yylval = p;
|
|
|
|
return retval;
|
|
}
|
|
|
|
/*
|
|
* Print error message and exit with error 2 (syntax error).
|
|
*/
|
|
static __printflike(1, 2) void
|
|
yyerror(const char *fmt, ...)
|
|
{
|
|
va_list arg;
|
|
|
|
va_start(arg, fmt);
|
|
verrx(2, fmt, arg);
|
|
va_end(arg);
|
|
}
|
|
|
|
int
|
|
main(int argc, const char * const *argv)
|
|
{
|
|
setprogname(argv[0]);
|
|
(void)setlocale(LC_ALL, "");
|
|
|
|
if (argc == 1) {
|
|
(void)fprintf(stderr, "usage: %s expression\n",
|
|
getprogname());
|
|
exit(2);
|
|
}
|
|
|
|
av = argv + 1;
|
|
|
|
exit(yyparse());
|
|
/* NOTREACHED */
|
|
}
|