m4/common/m4y.y

%{
/*
 * CDDL HEADER START
 *
 * The contents of this file are subject to the terms of the
 * Common Development and Distribution License, Version 1.0 only
 * (the "License").  You may not use this file except in compliance
 * with the License.
 *
 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
 * or http://www.opensolaris.org/os/licensing.
 * See the License for the specific language governing permissions
 * and limitations under the License.
 *
 * When distributing Covered Code, include this CDDL HEADER in each
 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
 * If applicable, add the following below this CDDL HEADER, with the
 * fields enclosed by brackets "[]" replaced with your own identifying
 * information: Portions Copyright [yyyy] [name of copyright owner]
 *
 * CDDL HEADER END
 */
%}

/*
 * Copyright 2005 Sun Microsystems, Inc.  All rights reserved.
 * Use is subject to license terms.
 */

/*  Copyright (c) 1988 AT&T */
/*    All Rights Reserved   */

%{
#pragma ident   "%Z%%M% %I% %E% SMI"
extern long evalval;
#define YYSTYPE long
%}

%term DIGITS
%left OROR
%left ANDAND
%left '|' '^'
%left '&'
%right '!' '~'
%nonassoc GT GE LT LE NE EQ
%left '+' '-'
%left '*' '/' '%'
%right POWER
%right UMINUS
%%

s   : e = { evalval = $1; }
    |   = { evalval = 0; }
    ;

e   : e OROR e  = { $$ = ($1 != 0 || $3 != 0) ? 1 : 0; }
    | e ANDAND e    = { $$ = ($1 != 0 && $3 != 0) ? 1 : 0; }
    | '!' e     = { $$ = $2 == 0; }
    | '~' e     = { $$ = ~$2; }
    | e EQ e    = { $$ = $1 == $3; }
    | e NE e    = { $$ = $1 != $3; }
    | e GT e    = { $$ = $1 > $3; }
    | e GE e    = { $$ = $1 >= $3; }
    | e LT e    = { $$ = $1 < $3; }
    | e LE e    = { $$ = $1 <= $3; }
    | e '|' e   = { $$ = ($1 | $3); }
    | e '&' e   = { $$ = ($1 & $3); }
    | e '^' e   = { $$ = ($1 ^ $3); }
    | e '+' e   = { $$ = ($1 + $3); }
    | e '-' e   = { $$ = ($1 - $3); }
    | e '*' e   = { $$ = ($1 * $3); }
    | e '/' e   = { $$ = ($1 / $3); }
    | e '%' e   = { $$ = ($1 % $3); }
    | '(' e ')' = { $$ = ($2); }
    | e POWER e = { for ($$ = 1; $3-- > 0; $$ *= $1); }
    | '-' e %prec UMINUS    = { $$ = $2-1; $$ = -$2; }
    | '+' e %prec UMINUS    = { $$ = $2-1; $$ = $2; }
    | DIGITS    = { $$ = evalval; }
    ;

%%

#include "m4.h"
extern wchar_t *pe;
static int peek(int c, int r1, int r2);

int
yylex(void)
{
    while (*pe == ' ' || *pe == '\t' || *pe == '\n')
        pe++;
    switch (*pe) {
    case '\0':
    case '+':
    case '-':
    case '/':
    case '%':
    case '^':
    case '~':
    case '(':
    case ')':
        return (*pe++);
    case '*':
        return (peek('*', POWER, '*'));
    case '>':
        return (peek('=', GE, GT));
    case '<':
        return (peek('=', LE, LT));
    case '=':
        return (peek('=', EQ, EQ));
    case '|':
        return (peek('|', OROR, '|'));
    case '&':
        return (peek('&', ANDAND, '&'));
    case '!':
        return (peek('=', NE, '!'));
    default: {
        int base;

        evalval = 0;

        if (*pe == '0') {
            if (*++pe == 'x' || *pe == 'X') {
                base = 16;
                ++pe;
            } else
                base = 8;
        } else
            base = 10;

        for (;;) {
            int c, dig;

            c = *pe;

            if (is_digit(c))
                dig = c - '0';
            else if (c >= 'a' && c <= 'f')
                dig = c - 'a' + 10;
            else if (c >= 'A' && c <= 'F')
                dig = c - 'A' + 10;
            else
                break;

            evalval = evalval*base + dig;
            ++pe;
        }
        return (DIGITS);
    }
    }
}

static int
peek(int c, int r1, int r2)
{
    if (*++pe != c)
        return (r2);
    ++pe;
    return (r1);
}

/*ARGSUSED*/
static void
yyerror(YYCONST char *msg)
{
}