/* load.c: This code "loads" code into the code segments. */ /* This file is part of GNU bc. Copyright (C) 1991-1994, 1997, 2000 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, Inc. 59 Temple Place, Suite 330 Boston, MA 02111 USA 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 *************************************************************************/ #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 pc; bc_function *f; char *new_body; /* If there was an error, don't continue. */ if (had_error) return; /* Calculate the segment and offset. */ pc = load_adr.pc_addr++; f = &functions[load_adr.pc_func]; if (pc >= f->f_body_size) { f->f_body_size *= 2; new_body = (char *) 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 byte. */ f->f_body[pc] = byte; f->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((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 (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; 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 >= '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; } 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++; } } }