Initial commit of files related to NED architecture.

[ned1] / nedasm / nedasm_structures.c

/*
* © 2018 Aaron Taylor <ataylor at subgeniuskitty dot com>
* See LICENSE.txt file for copyright and license details.
*/

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

#include "nedasm_structures.h"

struct instruction *
seek_instruction_list_start(struct instruction * instructions)
{
   if (instructions == NULL) return NULL;
   while (instructions->prev != NULL) instructions = instructions->prev;
   return instructions;
}

struct instruction *
seek_instruction_list_end(struct instruction * instructions)
{
   if (instructions == NULL) return NULL;
   while (instructions->next != NULL) instructions = instructions->next;
   return instructions;
}

void
insert_instruction_struct_before(struct instruction * list, struct instruction * new_node)
{
   new_node->next = list;
   new_node->prev = list->prev;
   list->prev = new_node;
   if (new_node->prev != NULL) (new_node->prev)->next = new_node;
}

void
insert_instruction_struct_after(struct instruction * list, struct instruction * new_node)
{
   new_node->prev = list;
   new_node->next = list->next;
   list->next = new_node;
   if (new_node->next != NULL) (new_node->next)->prev = new_node;
}

struct instruction *
remove_instruction_struct(struct instruction * instructions)
{
   //struct instruction * delete_me = instructions;
   struct instruction * return_me = NULL;

   if (instructions->prev != NULL) {
       instructions->prev->next = instructions->next;
       return_me = instructions->prev;
   }
   if (instructions->next != NULL) {
       instructions->next->prev = instructions->prev;
       if (return_me != NULL) return_me = instructions->next;
   }

   // TODO: Given the one-pass & die-early nature of this task, skip memory management entirely?
   //if (delete_me->label != NULL) free(delete_me->label);
   //if (delete_me->target != NULL) free(delete_me->target);
   //free(delete_me);

   return return_me;
}

struct instruction *
create_instruction_struct(void)
{
   struct instruction * new_struct = malloc(sizeof(struct instruction));
   new_struct->prev = NULL;
   new_struct->next = NULL;
   new_struct->linenum = 0;
   new_struct->syllable = 0;
   new_struct->data = 0;
   new_struct->target = NULL;
   new_struct->label = NULL;
   new_struct->address = 0;
   return new_struct;
}

void
insert_NOP_structs_after(struct instruction * list, uint8_t count)
{
   while (count != 0) {
       struct instruction * new_struct = create_instruction_struct();
       new_struct->syllable = NOP;
       insert_instruction_struct_after(list, new_struct);
       count--;
   }
}

void
insert_NOP_structs_before(struct instruction * list, uint8_t count)
{
   while (count != 0) {
       struct instruction * new_struct = create_instruction_struct();
       new_struct->syllable = NOP;
       insert_instruction_struct_before(list, new_struct);
       count--;
   }
}