/*******************************************************
 *
 *  a56 - a DSP56001 assembler
 *
 *  Written by Quinn C. Jensen
 *  July 1990
 *  jensenq@npd.novell.com (or jensenq@qcj.icon.com)
 *
 *******************************************************\

/*
 * Copyright (C) 1990-1992 Quinn C. Jensen
 *
 * Permission to use, copy, modify, distribute, and sell this software
 * and its documentation for any purpose is hereby granted without fee,
 * provided that the above copyright notice appear in all copies and
 * that both that copyright notice and this permission notice appear
 * in supporting documentation.  The author makes no representations
 * about the suitability of this software for any purpose.  It is
 * provided "as is" without express or implied warranty.
 *
 */
static char *Copyright = "Copyright (C) 1990-1992 Quinn C. Jensen";

/*
 *  subs.c - Some subroutines for the assembler.
 *
 */

#include "a56.h"

#define MAX 1024

char *alloc();

FILE *open_read(file)
char *file;
{
    FILE *fp;

    if(strcmp(file, "-") == 0)
	fp = stdin;
    else if ((fp = fopen(file, "r")) == NULL) {
        perror(file);
        exit(1);
    }    
    return(fp);
}

FILE *open_write(file)
char *file;
{
    FILE *fp;
    if ((fp = fopen(file, "w")) == NULL) {
        perror(file);
        exit(1);
    }    
    return(fp);
}

FILE *open_append(file)
char *file;
{
    FILE *fp;
    if ((fp = fopen(file, "a")) == NULL) {
        perror(file);
        exit(1);
    }    
    return(fp);
}

fatal(c, a1, a2, a3, a4, a5, a6, a7, a8)
char *c, *a1, *a2, *a3, *a4, *a5, *a6, *a7, *a8;
{
    fprintf(stderr, c, a1, a2, a3, a4, a5, a6, a7, a8);
    exit(1);
}

#define TABS 8
#define MAX_BUF 256

char tabbuf[MAX_BUF], *untabn();
char *untab(s)    /* expand tabs in s */
register char *s;
{
    return(untabn(s, TABS));
}

char *untabn(s, stops)    /* expand tabs in s */
register char *s;
register int stops;
{
    char *o = s;

    /* copy input string into buffer to scan while input string is modified */

    register char *b = tabbuf;
    
    strncpy(b, s, MAX_BUF);

    /* iterate until the copy of the input string is depleted */

    while(*b) {
        if(*b == '\t') {
	    do
                *s = ' ';
	    while ((++s - o) % stops);
        } else {
            *s = *b; s++;
        }
        b++;
    }

    /* null terminate the resultant string */

    *s = '\0';

    return(o);
}

char *alloc(size)
int size;
{
    char *p = (char *)malloc(size);
    if(NOT p)
	fatal("alloc:  insufficient virtual memory to allocate %d bytes\n", 
	    size);
    return(p);
}

#define ascii2n(c)  \
    ((c) >= 'a' ? (c) - 'a' + 10 : ((c) >= 'A' ? (c) - 'A' + 10 : (c) - '0'))

#define valid(c) ((c) >= '0' && (c) <= '9' || \
    (c) >= 'A' && (c) <= 'Z' || \
    (c) >= 'a' && (c) <= 'z')

strtol(s, p, base)
register char *s, **p;
register int base;
{
    register long result = 0;
    register int sign = 0;

    while(*s == ' ' || *s == '\t')
	s++;

    if(*s == '-') {
	s++;
	sign++;
    }

    while(valid(*s)) {
	register int dig = ascii2n(*s);
	if(dig >= base)
	    break;
	result *= base;
	result += dig;
 	s++;
    }

    if(p)
	*p = s;

    return (sign ? -result : result);
}