def main():
argparser = add_args()
args = argparser.parse_args()
file_name = args.source
target_name = args.target
verbose = args.verbose
# build symbol table
if verbose:
print("Beginning symbol pass")
with open(file_name, "r") as source:
line = 0
for command in source:
command = clear_trash(command)
if parser.command_type(command) in ["A_COMMAND", "C_COMMAND"]:
line += 1
elif parser.command_type(command) is "L_COMMAND":
if verbose:
print("Pseudocommand found at line {0}: {1}".format(
line, command))
symbols[parser.symbol(clear_trash(command))] = str(line)
print("Symbol {0} installed at line: {1}".format(
parser.symbol(clear_trash(command)), line))
# assemble code
if verbose:
print("Beginning assembly pass")
with open(file_name, "r") as source, open(target_name, "w") as target:
for command in source:
command = clear_trash(command)
if len(command) is not 0:
target.write(get_code(command))
def pass2(file_name):
#first address for symbol memory
with open(file_name, 'r') as asm_file:
address = 16
command_list = []
for command in asm_file:
current_command = parser.clean(command)
#skip further processing if line made up of only spaces and/or comments
if current_command:
if parser.command_type(current_command) == 'C_Command':
dest = parser.dest(current_command)
comp = parser.comp(current_command)
jump = parser.jump(current_command)
binary_repr = code.binary_code(dest, comp, jump)
command_list.append(binary_repr)
elif parser.command_type(current_command) == 'A_Command':
symbol = parser.symbol(current_command)
#if symbol doesn't begin with a numeric value, check symbol table for
#correct value. Add new symbol if necessary
try:
int_symbol = int(symbol)
except ValueError:
if not sym_table.contains(symbol):
sym_table.add_entry(symbol, address)
address += 1
symbol = sym_table.get_address(symbol)
#convert decimal symbol to binary and add to command_list
binary_symbol = "{0:016b}".format(int(symbol))
command_list.append(binary_symbol)
return command_list
def get_code(command):
command = clear_trash(command)
output = ""
if parser.command_type(command) == "A_COMMAND":
output = "0" + address_of(parser.symbol(command)) + "\n"
elif parser.command_type(command) == "L_COMMAND":
pass
elif parser.command_type(command) == "C_COMMAND":
dest = code.dest(parser.dest(command))
jump = code.jump(parser.jump(command))
comp = code.comp(parser.comp(command))
output = "111" + comp + dest + jump + "\n"
else:
raise ValueError("Code not a valid command: {0}".format(command))
return output
def write_push_pop():
base = arg1()
if base == 'static':
f.write('@16' + '\n')
f.write('D=A' + '\n')
elif base == 'local':
f.write('@LCL' + '\n')
f.write('D=M' + '\n')
elif base == 'argument':
f.write('@ARG' + '\n')
f.write('D=M' + '\n')
elif base == 'this':
f.write('@THIS' + '\n')
f.write('D=M' + '\n')
elif base == 'that':
f.write('@THAT' + '\n')
f.write('D=M' + '\n')
elif base == 'constant':
f.write('@SP' + '\n')
f.write('D=A' + '\n')
elif base == 'temp':
f.write('@5' + '\n')
f.write('D=A' + '\n')
f.write('@R13' + '\n')
f.write('M=D' + '\n')
index = arg2()
f.write('@' + index + '\n')
f.write('D=A' + '\n')
f.write('@R13' + '\n')
f.write('M=M+D' + '\n')
command = command_type()
if command == 'C_PUSH':
f.write('D=M' + '\n')
if base != 'constant':
f.write('A=D' + '\n')
f.write('D=M' + '\n')
f.write('@SP' + '\n')
f.write('M=M+1' + '\n')
f.write('A=M-1' + '\n')
f.write('M=D' + '\n')
else: # (if command == 'C_POP')
f.write('@SP' + '\n')
f.write('M=M-1' + '\n')
f.write('A=M+1' + '\n')
f.write('D=M' + '\n')
f.write('@R13' + '\n')
f.write('A=M' + '\n')
f.write('M=D' + '\n')
def write_push_pop () :
base = arg1()
if base == 'static' :
f.write('@16' + '\n')
f.write('D=A' + '\n')
elif base == 'local' :
f.write('@LCL' + '\n')
f.write('D=M' + '\n')
elif base == 'argument' :
f.write('@ARG' + '\n')
f.write('D=M' + '\n')
elif base == 'this' :
f.write('@THIS' + '\n')
f.write('D=M' + '\n')
elif base == 'that' :
f.write('@THAT' + '\n')
f.write('D=M' + '\n')
elif base == 'constant' :
f.write('@SP' + '\n')
f.write('D=A' + '\n')
elif base == 'temp' :
f.write('@5' + '\n')
f.write('D=A' + '\n')
f.write('@R13' + '\n')
f.write('M=D' + '\n')
index = arg2()
f.write('@' + index + '\n')
f.write('D=A' + '\n')
f.write('@R13' + '\n')
f.write('M=M+D' + '\n')
command = command_type()
if command == 'C_PUSH' :
f.write('D=M' + '\n')
if base != 'constant' :
f.write('A=D' + '\n')
f.write('D=M' + '\n')
f.write('@SP' + '\n')
f.write('M=M+1' + '\n')
f.write('A=M-1' + '\n')
f.write('M=D' + '\n')
else : # (if command == 'C_POP')
f.write('@SP' + '\n')
f.write('M=M-1' + '\n')
f.write('A=M+1' + '\n')
f.write('D=M' + '\n')
f.write('@R13' + '\n')
f.write('A=M' + '\n')
f.write('M=D' + '\n')
def pass1(file_name, sym_table):
with open(file_name, 'r') as asm_file:
program_counter = 0
#Go through file once, find the loops and store them in the symbol table
for command in asm_file:
current_command = parser.clean(command)
#skip further processing if line made up of only spaces and/or comments
if current_command:
if parser.command_type(current_command) == 'L_Command':
loop_symbol = parser.symbol(current_command)
sym_table.add_entry(loop_symbol, program_counter)
else:
program_counter += 1
from code_writer import set_file_name, write_arithmetic, write_push_pop, close
from parser import command_type, arg1, arg2, advance
import sys
vm_fn = sys.argv[1]
vm_code = open(vm_fn, 'r').read().split('\n')
set_file_name(vm_fn)
complete = advance(vm_code)
while not complete:
C_type = command_type()
if C_type == 'C_ARITHMETIC':
write_arithmetic()
elif C_type == 'C_PUSH' or C_type == 'C_POP':
write_push_pop()
complete = advance(vm_code)
close()
from code_writer import set_file_name, write_arithmetic, write_push_pop, close
from parser import command_type, arg1, arg2, advance
import sys
vm_fn = sys.argv[1]
vm_code = open(vm_fn, 'r').read().split('\n')
set_file_name(vm_fn)
complete = advance(vm_code)
while not complete :
C_type = command_type()
if C_type == 'C_ARITHMETIC' :
write_arithmetic()
elif C_type == 'C_PUSH' or C_type == 'C_POP' :
write_push_pop()
complete = advance(vm_code)
close()
