def main(debug, b_reg):
"""
in: bool debug, bool b register
out: void
"""
ML = []
st = SymbolTable()
if len(sys.argv) < 2:
no_file_arg()
input_file = sys.argv[1]
name = os.path.splitext(input_file)[0]
parsed = Parser(input_file, debug, b_reg)
rom_address = 0
ram_address = 16
"""
First pass
"""
while parsed.has_more_cmds():
if parsed.command_type() == "C_COMMAND" or parsed.command_type() == "A_COMMAND":
rom_address += 1
elif parsed.command_type() == "L_COMMAND":
st.add_entry(parsed.symbol(), rom_address)
parsed.advance()
parsed.reset()
"""
Second pass
"""
i = 0
while parsed.has_more_cmds():
cc = parsed.b_cc() # account for b reg
command_type = parsed.command_type()
if command_type == "A_COMMAND":
"""
Handle A commands.
"""
if st.contains(cc[1:]):
ML.append(parsed.a_int_to_binary(st.get_address(cc[1:])))
elif parsed.cc_is_int():
ML.append(parsed.a_int_to_binary(cc))
elif not st.contains(cc[1:]):
st.add_entry(cc[1:], ram_address)
ML.append(parsed.a_int_to_binary(str(st.get_address(cc[1:]))))
ram_address += 1
else:
ML.append(parsed.c_to_binary(cc, command_type, st))
parsed.advance()
i += 1
create_file(ML, name)
class Main(object):
def __init__(self, f):
self.asm_file = f
self.table = SymbolTable()
self.data = self.read_file()
self.parser = Parser(self.data)
self.commands = self.parser.commands
self.translator = Translator()
self.filename = self.asm_file.split(".")[0]
def read_file(self):
with open(self.asm_file) as f:
data = f.readlines()
return data
def write_file(self, output_lines):
with open('%sassembled.hack' % self.filename, 'w') as output_file:
for line in output_lines:
output_file.write(line + '\n')
def assemble(self):
self.first_pass()
output_lines = self.second_pass()
self.write_file(output_lines)
def first_pass(self):
program_line = 0
for line in self.commands:
# if we have encountered a label pseudocommand
# check if it is in the table, if not assign it to value of next program line
# don't increment program counter because this shouldn't count as a program line
if line[0] == '(':
if not self.table.contains(line[1:-1]):
self.table.add_entry(line[1:-1], program_line)
continue
# if none of these conditions are hit, keep incrementing program line
program_line += 1
def second_pass(self):
translated_commands = []
next_available_RAM = 16
for line in self.commands:
if line[0] == '@':
symbol = line[1:]
try:
# translate directly if @ is referencing a specific value
translated_commands.append('{0:016b}'.format(int(symbol)))
continue
except ValueError:
pass
# check if symbol is already in the symbol table and convert value to binary
if self.table.contains(symbol):
translated_commands.append('{0:016b}'.format(
self.table.get_address(symbol)))
# add symbol to symbol table, increment available RAM count, and translate to binary
else:
self.table.add_entry(symbol, next_available_RAM)
next_available_RAM += 1
translated_commands.append('{0:016b}'.format(
self.table.get_address(symbol)))
elif line[0] == '(':
continue
else:
translated_commands.append(
self.translator.handle_C_instruction(line))
return translated_commands
class Assembler():
'''
Takes a single .asm file as input and outputs a .hack file with the same name.
The assembling takes three passes.
- Preprocess: Remove whitespace and comments
- First Pass: Generate symbol table and remove symbolic labels
- Second Pass: Translates the .asm file into a .hack file, line by line.
'''
def __init__(self, filename):
self._input = self.preprocess(filename)
self._name = filename.split('/')[-1]
self._name = self._name.split('.')[0]
self._table = SymbolTable()
self.first_pass()
self._parser = Parser(self._input)
self._output = []
self._code = Code()
self.second_pass()
self.write_output()
def preprocess(self, filename):
with open(filename, 'r') as temp:
assembly = temp.readlines()
temp = []
for line in assembly:
# remove comments and white space
line = line.split('//')[0].strip().replace(' ', '')
if line:
# if nonempty, then it should contain valid asm
temp += [line]
return temp
def first_pass(self):
rom_addr = 0
temp = []
for line in self._input:
if '(' in line:
symbol = line[1:-1]
self._table.add_entry(symbol, rom_addr)
else:
temp += [line]
rom_addr += 1
self._input = temp
def second_pass(self):
while self._parser.has_more_commands():
self._parser.advance()
if self._parser.command_type() == 'A':
# A type command
value = self._parser.symbol()
if set(value) <= set('0123456789'):
# symbol is a number
value = int(value)
elif self._table.contains(value):
# symbol is a label
value = self._table.get_address(value)
else:
# symbol is a variable
self._table.add_entry(value)
value = self._table.get_address(value)
self._output += ['0' + "{0:015b}".format(value) + '\n']
elif self._parser.command_type() == 'C':
# C type command
self._output += [
'111' + self._code.comp(self._parser.comp()) +
self._code.dest(self._parser.dest()) +
self._code.jump(self._parser.jump()) + '\n'
]
def write_output(self):
with open('hack/' + self._name + '.hack', 'w') as temp:
temp.writelines(self._output)
print(self._name + '.asm', 'translated to',
'hack/' + self._name + '.hack')