/*      $NetBSD: gsp_gram.y,v 1.4 2025/11/24 08:04:28 nia Exp $ */
/*
 * Yacc syntax for GSP assembler
 *
 * Copyright (c) 1993 Paul Mackerras.
 * All rights reserved.
 *
 * 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.
 * 3. The name of the author may not be used to endorse or promote products
 *    derived from this software without specific prior written permission
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``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 AUTHOR 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.
 */

/* declarations */

%{
#include <sys/cdefs.h>
#ifndef lint
__RCSID("$NetBSD: gsp_gram.y,v 1.4 2025/11/24 08:04:28 nia Exp $");
#endif

#include <stdio.h>
#include "gsp_ass.h"
%}

%union {
        long            y_int;
        char            *y_id;
        expr            y_expr;
        operand         y_opnd;
}

%token LEFT_SHIFT, RIGHT_SHIFT

%term <y_id>    ID, STRING
%term <y_int>   NUMBER, REGISTER
%term UMINUS

/* operator precedences - lowest to highest */
%nonassoc ':'           /* concatenate y:x */
%left LEFT_SHIFT, RIGHT_SHIFT
%left '^'               /* EXCLUSIVE OR operator */
%left '|'               /* OR operator */
%left '&'               /* AND operator */
%left '+', '-'
%left '*', '/'
%nonassoc '~', UMINUS   /* NOT operator */

%start line

/* types of non-terminals */
%type <y_expr>          expr
%type <y_opnd>          operand, operands, ea

%%
/* rules */

line            : label ID operands     { statement($2, $3); }
                | ID operands           { statement($1, $2); }
                | label
                | ID '=' expr           { do_asg($1, $3, 0); }
                | /* empty */
                | error
                ;

label           : ID ':'                { set_label($1); }
                | NUMBER ':'            { set_numeric_label($1); }
                ;

operands        : /* empty */           { $$ = NULL; }
                | operand               { $$ = $1; }
                | operands ',' operand  { $$ = add_operand($1, $3); }
                ;

operand         : REGISTER              { $$ = reg_op($1); }
                | ea                    { $$ = $1; }
                | expr                  { $$ = expr_op($1); }
                | STRING                { $$ = string_op($1); }
                ;

ea              : '@' expr              { $$ = abs_adr($2); }
                | '*' REGISTER          { $$ = reg_ind($2, M_IND); }
                | '*' REGISTER ID       { $$ = reg_indxy($2, $3); }
                | '*' REGISTER '+'      { $$ = reg_ind($2, M_POSTINC); }
                | '*' '-' REGISTER      { $$ = reg_ind($3, M_PREDEC); }
                | '-' '*' REGISTER      { $$ = reg_ind($3, M_PREDEC); }
                | '*' REGISTER '(' expr ')'
                                        { $$ = reg_index($2, $4); }
                ;

expr            : ID                    { $$ = id_expr($1); }
                | NUMBER                { $$ = num_expr($1); }
                | '.'                   { $$ = here_expr(); }
                | '(' expr ')'          { $$ = $2; }
                | '~' expr              { $$ = bexpr('~', $2, NULL); }
                | '-' expr                      %prec UMINUS
                                        { $$ = bexpr(NEG, $2, NULL); }
                | expr '*' expr         { $$ = bexpr('*', $1, $3); }
                | expr '/' expr         { $$ = bexpr('/', $1, $3); }
                | expr '+' expr         { $$ = bexpr('+', $1, $3); }
                | expr '-' expr         { $$ = bexpr('-', $1, $3); }
                | expr '&' expr         { $$ = bexpr('&', $1, $3); }
                | expr '|' expr         { $$ = bexpr('|', $1, $3); }
                | expr '^' expr         { $$ = bexpr('^', $1, $3); }
                | expr ':' expr         { $$ = bexpr(':', $1, $3); }
                | expr LEFT_SHIFT expr  { $$ = bexpr(LEFT_SHIFT, $1, $3); }
                | expr RIGHT_SHIFT expr { $$ = bexpr(RIGHT_SHIFT, $1, $3); }
                ;