def simulate(self, max_time):
# TODO: here you can change the number of register you want to use
# Prepare the environment for the simulation
# 3 registers and 256 of memory
environment = Environment(self.MAX_REG, 256, self.root.labels)
start_time = time.time()
current_instruction = 0
current_line = self.root[current_instruction].line
try:
# Execute the simulation
while True:
# While the time has not been exceeded
elapsed_time = time.time() - start_time
if elapsed_time > max_time:
raise SimulationError("Maximum time allowed for the simulation exceeded!")
# Check if the simulation is over
if current_instruction >= len(self.root) - 1:
break
# Do the instruction logic
current_instruction = visit_parse_tree(self.root[current_instruction], SimulatorVisitor(environment))
current_line = self.root[current_instruction].line
# Add the line who crashed so it's easier to debug
except SimulationError as error:
message, = error.args
raise SimulationError(message + " occurred at line " + str(current_line))
# Print the finale results
environment.print()
def fetch_variable(self, variable, can_create_variable=False):
# Try to get the memory address
if not (variable[0].isalpha() and variable.isalnum()):
raise SimulationError("Variable «" + variable + "» is not a valid name.")
# Manage the variable creation if needed
if variable not in self.__variables:
if not can_create_variable:
raise SimulationError("The variable «" + variable + "» cannot be found!")
elif len(self.__variables) == self.__memory_size:
raise SimulationError("The maximum number of variables has been reached!")
self.__variables[variable] = len(self.__variables)
return self.__variables[variable]
def visit_instruction(self, node, children):
# The child of an instruction is a label and an operation
# The only result from childs are next operations
next_instruction = node.instruction + 1
if len(children) == 1:
next_instruction = children[-1]
elif len(children) > 1:
raise SimulationError("Unexpected number of children")
return next_instruction
def fetch_label_mapping(self, label):
if label not in self.__labels:
raise SimulationError("«" + label +
"» has not been found in the program")
return self.__labels[label]
def fetch_memory(self, address):
if address < 0 or address >= self.__memory_size:
raise SimulationError("«R" + str(address) + "» is out of bound")
return self.__memory[address]
def fetch_register(self, index):
if index < 0 or index >= self.__nb_registers:
raise SimulationError("«R" + str(index) + "» is out of bound")
return self.__registers[index]