symbolTable.c

/*
 ====================================================================================
 Name		: 	symbolTable.c
 Description: 	This file holds methods relevant to working with the symbol table
 ====================================================================================
 */

#include "structs.h"
#include "functions.h"

/* SymbolTable head and tail */
symbol_node_ptr p_symbol_head = NULL;
symbol_node_ptr p_symbol_tail = NULL;

/* Description: Updates symbol's address after first transition ends */
void update_symbol_address(int ic_length) {
	symbol_node_ptr p_current = p_symbol_head;

	while (p_current != NULL) {
		/* The symbol isn't external */
		if (!p_current->current_symbol.is_external) {
			/* The symbol is an instruction (.data or .string) */
			if (p_current->current_symbol.is_instruction) {
				p_current->current_symbol.address += ic_length + ADDRESS_START;
			} else {
				p_current->current_symbol.address += ADDRESS_START;
			}
		}

		p_current = p_current->next;
	}
}/*end of update_symbol_address method*/

/* Description: Search input symbol in symbol table */
symbol_node_ptr search_symbol(char* symbol_name) {
	symbol_node_ptr p_current = p_symbol_head;

	/* Scan symbol table */
	while ((p_current != NULL) && (strcmp(p_current->current_symbol.name, symbol_name) != 0)) {
		p_current = p_current->next;
	}

	return p_current;
}/*end of search_symbol method*/

/* Description: Creates a new symbol node */
symbol_node_ptr create_symbol(char* name, unsigned int address, bool is_extern, bool is_instruction) {
	symbol_node_ptr p_node = (symbol_node_ptr)allocate_memory(sizeof(symbol_node));

	/* Copy data into node */
	if (p_node != NULL) {
		p_node->current_symbol.name = name;
		p_node->current_symbol.is_external = is_extern;
		p_node->current_symbol.is_instruction = is_instruction;
		p_node->current_symbol.address = address;
		p_node->next = NULL;
	}

	return p_node;
}/*end of create_symbol method*/

/* Description: Adds a new symbol to the list */
void add_symbol_to_list(symbol_node_ptr p_new_symbol) {
	/* List is empty */
	if (p_symbol_head == NULL) {
		p_symbol_head = p_new_symbol;
		p_symbol_tail = p_new_symbol;
	} else {
		p_symbol_tail->next = p_new_symbol;
		p_symbol_tail = p_new_symbol;
	}
}/*end of add_symbol_to_list method*/

/* Description: Free symbol list from memory */
void free_symbol_list() {
	symbol_node_ptr p_cleaner_data = p_symbol_head;

	/* Clean nodes until no more nodes */
	while (p_symbol_head) {
		p_cleaner_data = p_symbol_head;
		p_symbol_head = p_symbol_head->next;
		free (p_cleaner_data);
	}
	return;
}/*end of free_symbol_list method*/