Function exec_stmt_fori

src/pl/plpgsql/src/pl_exec.c:2639–2772

---------- * exec_stmt_fori Iterate an integer variable * from a lower to an upper value * incrementing or decrementing by the BY value * ---------- */

 * ----------
 */
static int
exec_stmt_fori(PLpgSQL_execstate *estate, PLpgSQL_stmt_fori *stmt)
{
	PLpgSQL_var *var;
	Datum		value;
	bool		isnull;
	Oid			valtype;
	int32		valtypmod;
	int32		loop_value;
	int32		end_value;
	int32		step_value;
	bool		found = false;
	int			rc = PLPGSQL_RC_OK;

	var = (PLpgSQL_var *) (estate->datums[stmt->var->dno]);

	/*
	 * Get the value of the lower bound
	 */
	value = exec_eval_expr(estate, stmt->lower,
						   &isnull, &valtype, &valtypmod);
	value = exec_cast_value(estate, value, &isnull,
							valtype, valtypmod,
							var->datatype->typoid,
							var->datatype->atttypmod);
	if (isnull)
		ereport(ERROR,
				(errcode(ERRCODE_NULL_VALUE_NOT_ALLOWED),
				 errmsg("lower bound of FOR loop cannot be null")));
	loop_value = DatumGetInt32(value);
	exec_eval_cleanup(estate);

	/*
	 * Get the value of the upper bound
	 */
	value = exec_eval_expr(estate, stmt->upper,
						   &isnull, &valtype, &valtypmod);
	value = exec_cast_value(estate, value, &isnull,
							valtype, valtypmod,
							var->datatype->typoid,
							var->datatype->atttypmod);
	if (isnull)
		ereport(ERROR,
				(errcode(ERRCODE_NULL_VALUE_NOT_ALLOWED),
				 errmsg("upper bound of FOR loop cannot be null")));
	end_value = DatumGetInt32(value);
	exec_eval_cleanup(estate);

	/*
	 * Get the step value
	 */
	if (stmt->step)
	{
		value = exec_eval_expr(estate, stmt->step,
							   &isnull, &valtype, &valtypmod);
		value = exec_cast_value(estate, value, &isnull,
								valtype, valtypmod,
								var->datatype->typoid,