summaryrefslogtreecommitdiffstats
path: root/gnu/usr.bin/bc/load.c
diff options
context:
space:
mode:
Diffstat (limited to 'gnu/usr.bin/bc/load.c')
-rw-r--r--gnu/usr.bin/bc/load.c333
1 files changed, 333 insertions, 0 deletions
diff --git a/gnu/usr.bin/bc/load.c b/gnu/usr.bin/bc/load.c
new file mode 100644
index 0000000..be4ab3a
--- /dev/null
+++ b/gnu/usr.bin/bc/load.c
@@ -0,0 +1,333 @@
+/* load.c: This code "loads" code into the code segments. */
+
+/* This file is part of bc written for MINIX.
+ Copyright (C) 1991, 1992 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 2 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, write to
+ the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA.
+
+ You may contact the author by:
+ e-mail: phil@cs.wwu.edu
+ us-mail: Philip A. Nelson
+ Computer Science Department, 9062
+ Western Washington University
+ Bellingham, WA 98226-9062
+
+*************************************************************************/
+
+#include "bcdefs.h"
+#include "global.h"
+#include "proto.h"
+
+/* Load variables. */
+
+program_counter load_adr;
+char load_str;
+char load_const;
+
+/* Initialize the load sequence. */
+void
+init_load ()
+{
+ 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 (byte)
+ char byte;
+{
+ int seg, offset, func;
+
+ /* If there was an error, don't continue. */
+ if (had_error) return;
+
+ /* Calculate the segment and offset. */
+ seg = load_adr.pc_addr >> BC_SEG_LOG;
+ offset = load_adr.pc_addr++ % BC_SEG_SIZE;
+ func = load_adr.pc_func;
+
+ if (seg >= BC_MAX_SEGS)
+ {
+ yyerror ("Function too big.");
+ return;
+ }
+
+ if (functions[func].f_body[seg] == NULL)
+ functions[func].f_body[seg] = (char *) bc_malloc (BC_SEG_SIZE);
+
+ /* Store the byte. */
+ functions[func].f_body[seg][offset] = byte;
+ functions[func].f_code_size++;
+}
+
+
+/* Define a label LAB to be the current program counter. */
+
+void
+def_label (lab)
+ long lab;
+{
+ bc_label_group *temp;
+ int 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_label_group *) 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_label_group *) 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 (str)
+ char **str;
+{ int val = 0;
+ char neg = FALSE;
+
+ if (**str == '-')
+ {
+ neg = TRUE;
+ (*str)++;
+ }
+ while (isdigit(**str))
+ val = val*10 + *(*str)++ - '0';
+
+ if (neg)
+ return -val;
+ else
+ return val;
+}
+
+
+/* load_code loads the CODE into the machine. */
+
+void
+load_code (code)
+ char *code;
+{
+ char *str;
+ long ap_name; /* auto or parameter name. */
+ long label_no;
+ long vaf_name; /* variable, array or function number. */
+ long func;
+ 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 >= '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");
+ 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;
+ }
+ 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);
+ }
+
+ /* 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);
+ }
+ 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++;
+ }
+ }
+}
OpenPOWER on IntegriCloud