/*      $NetBSD: gsp_lex.c,v 1.10 2025/11/24 08:04:28 nia Exp $ */
/*
 * Lexical analyser 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.
 */

#include <sys/cdefs.h>
#ifndef lint
__RCSID("$NetBSD: gsp_lex.c,v 1.10 2025/11/24 08:04:28 nia Exp $");
#endif

#include <stdio.h>
#include <ctype.h>
#include <stdlib.h>
#include <string.h>

#include "gsp_ass.h"
#include "gsp_gram.h"

char *lineptr;

char idents[MAXLINE];
char *idptr;

extern YYSTYPE yylval;

int str_match(const char *, const char **);

const char *regnames[] = {
        "A0",   "A1",   "A2",   "A3",   "A4",   "A5",   "A6",   "A7",
        "A8",   "A9",   "A10",  "A11",  "A12",  "A13",  "A14",  "SP",
        "B0",   "B1",   "B2",   "B3",   "B4",   "B5",   "B6",   "B7",
        "B8",   "B9",   "B10",  "B11",  "B12",  "B13",  "B14",  "B15",
        NULL
};

short regnumbers[] = {
        GSPA_A0+0,  GSPA_A0+1,  GSPA_A0+2,  GSPA_A0+3,
        GSPA_A0+4,  GSPA_A0+5,  GSPA_A0+6,  GSPA_A0+7,
        GSPA_A0+8,  GSPA_A0+9,  GSPA_A0+10, GSPA_A0+11,
        GSPA_A0+12, GSPA_A0+13, GSPA_A0+14, GSPA_SP,
        GSPA_B0+0,  GSPA_B0+1,  GSPA_B0+2,  GSPA_B0+3,
        GSPA_B0+4,  GSPA_B0+5,  GSPA_B0+6,  GSPA_B0+7,
        GSPA_B0+8,  GSPA_B0+9,  GSPA_B0+10, GSPA_B0+11,
        GSPA_B0+12, GSPA_B0+13, GSPA_B0+14, GSPA_B0+15,
};

void
lex_init(char *lline)
{
        lineptr = lline;
        idptr = idents;
}

int
yylex()
{
        int c, tok, x, len;
        char *lp, *ip;
        char *end;

        lp = lineptr;
        c = *lp;
        while( c == ' ' || c == '\t' )
                c = *++lp;
        if( isalpha(c) || c == '_' || c == '.' ){
                /* an identifier or register name */
                ip = lp;
                do {
                        c = *++lp;
                } while( isalnum(c) || c == '_' );
                len = lp - ip;
                if( len == 1 && *ip == '.' )
                        tok = '.';
                else {
                        strncpy(idptr, ip, len);
                        idptr[len] = 0;
                        ucasify(idptr);
                        x = str_match(idptr, regnames);
                        if( x == -1 ){
                                strncpy(idptr, ip, len);
                                yylval.y_id = idptr;
                                idptr += len + 1;
                                tok = ID;
                        } else {
                                yylval.y_int = regnumbers[x];
                                tok = REGISTER;
                        }
                }
        } else if( c == '$' ){
                /* a hex number */
                ++lp;
                yylval.y_int = strtoul(lp, &end, 16);
                if( end == lp )
                        perr("Bad number syntax");
                else
                        lp = end;
                tok = NUMBER;
        } else if( isdigit(c) ){
                yylval.y_int = strtoul(lp, &end, 0);
                ip = lp;
                lp = end;
                c = *lp;
                if( (c == 'f' || c == 'F' || c == 'b' || c == 'B')
                   && !(isalnum((unsigned char)lp[1]) || lp[1] == '_') ){
                        /* reference to numeric label */
                        c = toupper(c);
                        sprintf(idptr, "%ld%c", (long)yylval.y_int, c);
                        yylval.y_id = idptr;
                        idptr += strlen(idptr) + 1;
                        ++lp;
                        tok = ID;
                } else
                        tok = NUMBER;
        } else if( c == '\n' ){
                tok = 0;        /* eof */
        } else if( c == ';' ){
                /* comment - skip to end of line */
                while( *++lp != 0 )
                        ;
                tok = 0;
        } else if( c == '"' ){
                /* string */
                yylval.y_id = idptr;
                while( (c = *++lp) != '"' && c != '\n' && c != 0 )
                        *idptr++ = c;
                *idptr++ = 0;
                if( c != '"' )
                        perr("Unterminated string");
                else
                        ++lp;
                tok = STRING;
        } else if( c == '<' && lp[1] == '<' ){
                lp += 2;
                tok = LEFT_SHIFT;
        } else if( c == '>' && lp[1] == '>' ){
                lp += 2;
                tok = RIGHT_SHIFT;
        } else {
                if( c != 0 )
                        ++lp;
                tok = c;
        }
        lineptr = lp;
        return tok;
}

void
ucasify(char *p)
{
        int c;

        for( ; (c = *p) != 0; p++ )
                if( islower(c) )
                        *p = toupper(c);
}

int
str_match(const char *id, const char **names)
{
        const char **np;

        for( np = names; *np != NULL; ++np )
                if( strcmp(id, *np) == 0 )
                        return np - names;
        return -1;
}