/* This file is part of GNU bc.
Copyright (C) 1991-1994, 1997, 2006, 2008, 2012-2017 Free Software Foundation, Inc.
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 3 of the License , or
(at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program; see the file COPYING. If not, see
<http://www.gnu.org/licenses>.
You may contact the author by:
e-mail: philnelson@acm.org
us-mail: Philip A. Nelson
Computer Science Department, 9062
Western Washington University
Bellingham, WA 98226-9062
*************************************************************************/
/* load.c: This code "loads" code into the code segments. */
#include "bcdefs.h"
#include "proto.h"
/* Load variables. */
program_counter load_adr;
char load_str;
char load_const;
/* Initialize the load sequence. */
void
init_load (void)
{
clear_func(0);
load_adr.pc_func = 0;
load_adr.pc_addr = 0;
load_str = FALSE;
load_const = FALSE;
}
/* addbyte adds one BYTE to the current code segment. */
void
addbyte (unsigned char thebyte)
{
unsigned long prog_addr;
bc_function *f;
char *new_body;
/* If there was an error, don't continue. */
if (had_error) return;
/* Calculate the segment and offset. */
prog_addr = load_adr.pc_addr++;
f = &functions[load_adr.pc_func];
if (prog_addr >= f->f_body_size)
{
f->f_body_size *= 2;
new_body = bc_malloc (f->f_body_size);
memcpy(new_body, f->f_body, f->f_body_size/2);
free (f->f_body);
f->f_body = new_body;
}
/* Store the thebyte. */
f->f_body[prog_addr] = (char) (thebyte & 0xff);
f->f_code_size++;
}
/* Define a label LAB to be the current program counter. */
void
def_label (unsigned long lab)
{
bc_label_group *temp;
unsigned long group, offset, func;
/* Get things ready. */
group = lab >> BC_LABEL_LOG;
offset = lab % BC_LABEL_GROUP;
func = load_adr.pc_func;
/* Make sure there is at least one label group. */
if (functions[func].f_label == NULL)
{
functions[func].f_label = bc_malloc (sizeof(bc_label_group));
functions[func].f_label->l_next = NULL;
}
/* Add the label group. */
temp = functions[func].f_label;
while (group > 0)
{
if (temp->l_next == NULL)
{
temp->l_next = bc_malloc (sizeof(bc_label_group));
temp->l_next->l_next = NULL;
}
temp = temp->l_next;
group --;
}
/* Define it! */
temp->l_adrs [offset] = load_adr.pc_addr;
}
/* Several instructions have integers in the code. They
are all known to be legal longs. So, no error code
is added. STR is the pointer to the load string and
must be moved to the last non-digit character. */
long
long_val (const char **str)
{ int val = 0;
char neg = FALSE;
if (**str == '-')
{
neg = TRUE;
(*str)++;
}
while (isdigit((int)(**str)))
val = val*10 + *(*str)++ - '0';
if (neg)
return -val;
else
return val;
}
/* load_code loads the CODE into the machine. */
void
load_code (const char *code)
{
const char *str;
unsigned long ap_name; /* auto or parameter name. */
unsigned long label_no;
unsigned long vaf_name; /* variable, array or function number. */
unsigned long func;
static program_counter save_adr;
/* Initialize. */
str = code;
/* Scan the code. */
while (*str != 0)
{
/* If there was an error, don't continue. */
if (had_error) return;
if (load_str)
{
if (*str == '"') load_str = FALSE;
addbyte (*str++);
}
else
if (load_const)
{
if (*str == '\n')
str++;
else
{
if (*str == ':')
{
load_const = FALSE;
addbyte (*str++);
}
else
if (*str == '.')
addbyte (*str++);
else
{
if (*str > 'F' && (warn_not_std || std_only))
{
if (std_only)
yyerror ("Error in numeric constant");
else
ct_warn ("Non-standard base in numeric constant");
}
if (*str >= 'A')
addbyte (*str++ + 10 - 'A');
else
addbyte (*str++ - '0');
}
}
}
else
{
switch (*str)
{
case '"': /* Starts a string. */
load_str = TRUE;
break;
case 'N': /* A label */
str++;
label_no = long_val (&str);
def_label (label_no);
break;
case 'B': /* Branch to label. */
case 'J': /* Jump to label. */
case 'Z': /* Branch Zero to label. */
addbyte(*str++);
label_no = long_val (&str);
if (label_no > 65535L)
{ /* Better message? */
fprintf (stderr,"Program too big.\n");
bc_exit(1);
}
addbyte ( (char) (label_no & 0xFF));
addbyte ( (char) (label_no >> 8));
break;
case 'F': /* A function, get the name and initialize it. */
str++;
func = long_val (&str);
clear_func (func);
#if DEBUG > 2
printf ("Loading function number %d\n", func);
#endif
/* get the parameters */
while (*str++ != '.')
{
if (*str == '.')
{
str++;
break;
}
if (*str == '*')
{
str++;
ap_name = long_val (&str);
#if DEBUG > 2
printf ("var parameter number %d\n", ap_name);
#endif
functions[(int)func].f_params =
nextarg (functions[(int)func].f_params, ap_name,
TRUE);
}
else
{
ap_name = long_val (&str);
#if DEBUG > 2
printf ("parameter number %d\n", ap_name);
#endif
functions[(int)func].f_params =
nextarg (functions[(int)func].f_params, ap_name,
FALSE);
}
}
/* get the auto vars */
while (*str != '[')
{
if (*str == ',') str++;
ap_name = long_val (&str);
#if DEBUG > 2
printf ("auto number %d\n", ap_name);
#endif
functions[(int)func].f_autos =
nextarg (functions[(int)func].f_autos, ap_name, FALSE);
}
save_adr = load_adr;
load_adr.pc_func = func;
load_adr.pc_addr = 0;
break;
case ']': /* A function end */
functions[load_adr.pc_func].f_defined = TRUE;
load_adr = save_adr;
break;
case 'C': /* Call a function. */
addbyte (*str++);
func = long_val (&str);
if (func < 128)
addbyte ( (char) func);
else
{
addbyte (((func >> 8) & 0xff) | 0x80);
addbyte (func & 0xff);
}
if (*str == ',') str++;
while (*str != ':')
addbyte (*str++);
addbyte (':');
break;
case 'c': /* Call a special function. */
addbyte (*str++);
addbyte (*str);
break;
case 'K': /* A constant.... may have an "F" in it. */
addbyte (*str);
load_const = TRUE;
break;
case 'd': /* Decrement. */
case 'i': /* Increment. */
case 'l': /* Load. */
case 's': /* Store. */
case 'A': /* Array Increment */
case 'M': /* Array Decrement */
case 'L': /* Array Load */
case 'S': /* Array Store */
addbyte (*str++);
vaf_name = long_val (&str);
if (vaf_name < 128)
addbyte (vaf_name);
else
{
addbyte (((vaf_name >> 8) & 0xff) | 0x80);
addbyte (vaf_name & 0xff);
}
break;
case '@': /* A command! */
switch (*(++str))
{
case 'i':
init_load ();
break;
case 'r':
execute ();
break;
}
break;
case '\n': /* Ignore the newlines */
break;
default: /* Anything else */
addbyte (*str);
}
str++;
}
}
}