variables_tab.c

#include "variables_tab.h"
#include "symbols_tab.h"

int vars_count=0;
int vars_capacity = 10;
int nextPos=0;

variable** vars_array;

// Utility function to initialize vars_array
void initVarTab()
{
    vars_array = malloc(vars_capacity*sizeof(variable*));
}

/*
  Function that simply returns the code of the variable given in the array of variables.
  If the variable does not exists, return NULL.
*/
variable* getVar(char* varName){
  int i;
  for (i = 0; i < vars_count; i++){
      // For each variable in the table, compare if it is the same as the input variable.
      if (strcmp(vars_array[i]->scalpavar, varName) == 0){
          return vars_array[i]; // Return the position of the variable in the table
      }
  }

  return NULL;
}

/*
  Function that returns the saved variables in a given char address.
*/
void vars_to_string(FILE *returns)
{

  if(vars_count == 0)
  {
    fprintf(stderr, "No variables found.\n\n");
  }

  int i;
  for (i = 0; i < vars_count; i++){
      // For each variable in the table, compare if it is the same as the input variable.
      variable* act_val = vars_array[i];
      fprintf(returns, "scalpavar: %s -- mipsvar: %d($sp)\n", act_val->scalpavar, act_val->p_memoire);
  }

}

/*
  Function that returns the result of the insertion in the vars_array.
*/
variable* insertVar(char* varName, int context, int type, int array_nbvars){
  // Report symbol to symbol table.
  insertSymbol(strdup(varName), type);

  // Retrieve the variable position in the table.
  variable* old_var = getVar(varName);

  // If the variable doesn't exist, create it.
  if(old_var != NULL)
  {
    // If the variable already exists in the current context, return false and do not insert it.
    if(old_var->context<=context)
    {
      return false;
    }
  }

  variable* new_var;

  new_var = newVar(varName, context, type, array_nbvars);

  // Variable successfully added. Return true then.
  return new_var;
}

/*
  Create a new variable object and return it.
*/
variable* newVar(char* varName, int context, int type, int array_nbvars)
{
  // If we add the variable in the table, update the variable_capacity
  if (vars_count >= vars_capacity) {
    vars_capacity*=2;
    vars_array = (variable**)realloc(vars_array, vars_capacity * sizeof(variable*));
  }

  variable* new_var = malloc(sizeof(variable));
  new_var->scalpavar = strdup(varName);
  new_var->context = context;
  new_var->type = type;
  new_var->init = false;
  new_var->p_memoire = nextPos;

  if(array_nbvars == 0)
  {
    nextPos +=4;
  }
  {
    nextPos +=4 * array_nbvars;
  }


  vars_array[vars_count] = new_var;
  vars_count++;

  return new_var;
}