symtable.c

/**
* School project to subject IFJ (Formal Languages and Compilers)
* Compiler implementation of imperative language IFJ18
*
* Module for hash table used as symbol table
*
* Author: Julius Marko
* Login:  xmarko17
*/

#include "symtable.h"
#include "error.h"
#include <stdio.h>

int hash_code(t_key key) {
    int retval = 1;
    size_t idlen = strlen(key);
    for (size_t i = 0; i < idlen; i++)
        retval += key[i];
    return (retval % SYMTABLE_SIZE);
}

void st_init(st *st_ptr) {
    for (int i = 0; i < SYMTABLE_SIZE; i++) {
        (*st_ptr)[i] = NULL;
    }
}

st_elem *st_search(st *st_ptr, t_key key) {
    if (st_ptr == NULL || key == NULL)
        return NULL;
    int index = hash_code(key);
    st_elem *tmp = (*st_ptr)[index];
    while (tmp) {
        if (strcmp(tmp->key, key) == 0) {
            return tmp;
        }
        tmp = tmp->ptrnext;
    }
    return NULL;
}

int st_insert(st *st_ptr, t_key key, st_elem_types elem_type, elem_data *data) {
    if (st_ptr == NULL || key == NULL) {
        return ERR_INTERNAL;
    }
    st_elem *tmp = st_search(st_ptr, key);
    if (tmp) {
        if (tmp->data != NULL) st_clear_elem_data(tmp);
        tmp->data = data;
    } else { // item with id doesnt exist
        tmp = malloc(sizeof(struct st_elem));
        if (tmp == NULL) {
            return ERR_INTERNAL;
        }
        tmp->key = malloc(sizeof(char) * (strlen(key) + 1));
        if (tmp->key == NULL) {
            return ERR_INTERNAL;
        }
        strcpy(tmp->key, key);
        tmp->elem_type = elem_type;
        tmp->data = data;
        tmp->ptrnext = NULL;
        int index = hash_code(key);
        if ((*st_ptr)[index]) { // insert before first item
            tmp->ptrnext = (*st_ptr)[index];
        }
        (*st_ptr)[index] = tmp;
    }
    return 0;
}

void st_clear_elem_data(st_elem *elem) {
    free(elem->data->id);
    if (elem->elem_type == FUNCTION && !elem->data->is_builtin) {
        for (size_t j = 0; j < elem->data->params_count; j++) {
            free(elem->data->params[j]);
        }
        free(elem->data->params);
    }
}

void st_clear_all(st *st_ptr) {
    if (st_ptr == NULL) {
        return;
    }
    st_elem *tmp, *next;
    for (size_t i = 0; i < SYMTABLE_SIZE; ++i) {
        next = (*st_ptr)[i];
        while (next) {
            tmp = next;
            next = tmp->ptrnext;
            free(tmp->key);
            st_clear_elem_data(tmp);
            free(tmp->data);
            free(tmp);
        }
        (*st_ptr)[i] = NULL;
    }
}