/
Assembler.py
77 lines (62 loc) · 1.63 KB
/
Assembler.py
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from Parser import *
from Code import *
from SymbolTable import *
class Assembler:
def __init__(self, filename):
i = filename.find('.')
if i != -1:
self.filename = filename[:i]
else:
self.filename = filename
self.p = Parser(filename)
self.buff = []
self.ops = []
self.table = SymbolTable()
def assemble(self):
self.__firstpass()
self.p.reset()
self.__secondpass()
def __firstpass(self):
addrcnt = 0
while self.p.hasMoreCmds():
if self.p.cmdType() == self.p.L_CMD:
label = self.p.sym()
if self.table.contains(label) == False:
self.table.addEntry(label, addrcnt)
else:
addrcnt += 1
self.p.advance()
def __secondpass(self):
varcnt = 0x10
while self.p.hasMoreCmds():
raw = ""
if self.p.cmdType() == self.p.A_CMD:
self.ops.append(self.p.getCurrent())
label = self.p.sym()
raw += "0"
val = 0
if label.isdigit() == False:
if self.table.contains(label) == False:
self.table.addEntry(label, varcnt)
varcnt += 1
val = self.table.getAddress(label)
else:
val = int(label)
s = bin(val)[2:]
raw += -len(s) % 15 * '0' + s
self.buff.append(raw)
elif self.p.cmdType() == self.p.C_CMD:
self.ops.append(self.p.getCurrent())
raw = "111" + Code.comp(self.p.comp()) + Code.dest(self.p.dest()) + Code.jump(self.p.jump())
self.buff.append(raw)
self.p.advance()
def output(self):
i = 0
print "Raw Machine Code..."
for inst in self.buff:
print '%0*X:'%(4, i), inst, '|', self.ops[i]
i += 1
def writetofile(self):
f = open(str(self.filename + ".hack"), 'w')
for item in self.buff:
f.write("%s\n"%item)