126 lines
3.2 KiB
Python
126 lines
3.2 KiB
Python
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import re
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from opcodes import OPCODES
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REGISTERS=["%rax", "%rbx", "%rcx", "%rdx", "%rsp", "%rbp", "%rsi", "%rdi",
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"%r8", "%r9", "%r10", "%r11", "%r12", "%r13", "%r14", "%r15"]
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class Emulator:
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def __init__ (self, source_text, max_stack_size=1000):
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self.registers = {}
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for reg_name in REGISTERS:
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self.registers[reg_name] = "Junk"
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self.stack = {}
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for i in range(max_stack_size):
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self.stack[i] = 0
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self.code = []
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self.labels = {}
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self.changes = {}
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self.status = {}
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self.last_sp = 0
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self.max_stack_size = 0
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index = 0
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for line in iter(source_text.splitlines()):
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index = self.processSourceLine(line, index)
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def setStack (self, *stack_list, **kwargs):
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"""
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Sets various stack elements, starting from 0 and going up.
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Automatically sets rsp. This can be disabled by passing set_rsp=False.
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"""
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i = len(self.stack)
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for element in stack_list:
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i -= 1
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self.stack[i] = element
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if (not 'set_rsp' in kwargs) or kwargs['set_rsp']:
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self.setRegs(rsp=i)
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self.last_sp = i-1
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def setRegs (self, **reg_dict):
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for reg_name, reg_val in reg_dict.iteritems():
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self.registers["%"+reg_name] = reg_val
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def getVal (self, val_text):
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if val_text[0] == "$":
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return int(val_text[1:])
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elif val_text[0] == "%":
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return self.registers[val_text]
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else:
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raise "NOT A VALUE! UGHGUIHGUE!"
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def compareVal (self, valT1, valT2):
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val1 = self.getVal(valT2)
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val2 = self.getVal(valT1)
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self.status["g"] = val1>val2
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self.status["l"] = val1<val2
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self.status["e"] = val1==val2
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def changedRegisters (self, *args):
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for reg, val in args:
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self.changes[reg] = val
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def processSourceLine(self, line_text, index):
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tokens = re.findall(r'[^\s,]+', line_text)
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if len(tokens) <= 0:
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return index
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if tokens[0][-1] == ':':
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self.labels[tokens[0][:-1]] = index
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tokens = tokens[1:]
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for i in range(len(tokens)):
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if tokens[i][0] == "#":
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tokens = tokens[:i]
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break
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self.code.append(tokens)
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return index + 1
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def regState (self, reg_name):
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if reg_name in self.changes:
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return self.changes[reg_name]
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else:
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return "none"
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def getLineSignature (self, line_nr):
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return [ "\\"+token if token[0]=="$" or token[0]=="%" else token for token in self.code[line_nr] ]
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def pushToStack (self, new_element):
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self.registers['%rsp'] -= 1
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self.stack[self.registers['%rsp']] = new_element
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self.changedRegisters(('%rsp',"change"), ("m"+str(self.registers['%rsp']),"insert"))
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self.max_stack_size = max(self.registers['%rsp'], self.max_stack_size)
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def popFromStack (self):
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temp = self.stack[self.registers['%rsp']]
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self.changedRegisters(('%rsp',"change"),("m"+str(self.registers['%rsp']),"remove"))
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self.registers['%rsp'] += 1
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return temp
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def iterate (self):
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old_rip = self.registers['%rip']
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self.last_sp = self.registers['%rsp']
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if self.registers['%rip'] >= len(self.code):
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return None
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instruct = self.code[self.registers['%rip']]
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opcode = instruct[0]
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self.changes = {}
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OPCODES[opcode](self, *instruct[1:])
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if self.registers['%rip'] == old_rip:
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self.registers['%rip'] += 1
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else:
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self.changedRegisters(('%rip',"jump"))
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return old_rip
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def __iter__(self):
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return self
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def next(self):
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output = self.iterate()
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if output is None:
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raise StopIteration()
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else:
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return output
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