Added Junk value, for which all operations are

defined to produce junk.
Any comparison involving junk triggers the i status register.
Any conditional jump triggered when the i register is true,
triggers a python level exception.

Emulator.py

@@ -1,24 +1,33 @@
 
 import re
 
+import Junk
 from opcodes import OPCODES
 
 REGISTERS=["%rax", "%rbx", "%rcx", "%rdx", "%rsp", "%rbp", "%rsi", "%rdi",
 			"%r8", "%r9", "%r10", "%r11", "%r12", "%r13", "%r14", "%r15"]
+JUNK_VALUE = Junk.Junk()
+
+class CodeParseException (BaseException):
+
+	def __init__ (self, line_nr, string):
+		self.line_nr = line_nr
+		self.string = string
 
 class Emulator:
 
 	def __init__ (self, source_text, max_stack_size=1000):
+		self.source = source_text
 		self.registers = {}
 		for reg_name in REGISTERS:
-			self.registers[reg_name] = "Junk"
+			self.registers[reg_name] = JUNK_VALUE
 		self.stack = {}
 		for i in range(max_stack_size):
-			self.stack[i] = 0
+			self.stack[i] = JUNK_VALUE
 		self.code = []
 		self.labels = {}
 		self.changes = {}
-		self.status = {}
+		self.status = {'i':True}
 		self.last_sp = 0
 		self.max_stack_size = 0
 		index = 0
@@ -48,14 +57,18 @@ class Emulator:
 		elif val_text[0] == "%":
 			return self.registers[val_text]
 		else:
-			raise "NOT A VALUE! UGHGUIHGUE!"
+			raise ValueError('{} is not an usable value name'.format(val_text))
 
 	def compareVal (self, valT1, valT2):
 		val1 = self.getVal(valT2)
 		val2 = self.getVal(valT1)
+		if isinstance(val1,Junk.Junk) or isinstance(val2,Junk.Junk):
+			self.status["i"] = (True,)
+			return
 		self.status["g"] = val1>val2
 		self.status["l"] = val1<val2
 		self.status["e"] = val1==val2
+		self.status["i"] = False
 
 	def changedRegisters (self, *args):
 		for reg, val in args:
@@ -63,7 +76,7 @@ class Emulator:
 
 	def processSourceLine(self, line_text, index):
 		tokens = re.findall(r'[^\s,]+', line_text)
-		if len(tokens) <= 0:
+		if len(tokens) <= 0 or tokens[0][0] == '#':
 			return index
 		if tokens[0][-1] == ':':
 			self.labels[tokens[0][:-1]] = index
@@ -96,6 +109,21 @@ class Emulator:
 		self.registers['%rsp'] += 1
 		return temp
 
+	def jump (self, label, cond_op="or", **conditions):
+		if len(conditions)>0 and self.status["i"]:
+			raise Junk.JunkComparisonException(*self.status['i'])
+		and_, or_ = True, False
+		for cnd_name, cnd_val in conditions.iteritems():
+			if self.status[cnd_name] == cnd_val:
+				or_ = True
+			else:
+				and_ = False
+		if or_ if cond_op=="or" else and_:
+			self.registers['%rip'] = self.labels[label]
+			return True
+		else:
+			return False
+
 	def iterate (self):
 		old_rip = self.registers['%rip']
 		self.last_sp = self.registers['%rsp']
@@ -123,3 +151,6 @@ class Emulator:
 			raise StopIteration()
 		else:
 			return output
+
+	def getUsedRegisters (self):
+		return [reg_name for reg_name, reg_val in self.registers.iteritems() if reg_val!=JUNK_VALUE]

Junk.py

@@ -0,0 +1,27 @@
+
+class JunkComparisonException (BaseException):
+
+	pass
+
+class Junk:
+
+	def __init__ (self):
+		pass
+
+	def __str__ (self):
+		return "[Junk]"
+
+	def __repr__ (self):
+		return "[Junk]"
+
+	def __add__ (self, other):
+		return self
+
+	def __radd__ (self, other):
+		return self
+
+	def __sub__ (self, other):
+		return self
+
+	def __rsub__ (self, other):
+		return self

infernal.py

@@ -2,8 +2,9 @@
 import sys
 import getopt
 
-from Emulator import Emulator
+from Emulator import Emulator, CodeParseException
 from TikzPainter import TikzPainter
+from Junk import Junk, JunkComparisonException
 
 if __name__ == "__main__":
 	pass

opcodes.py

@@ -45,33 +45,27 @@ def comp(emu, val1, val2):
 
 @add_opcode("jg")
 def jg(emu, label):
-	if emu.status["g"]:
+	emu.jump(label, g=True)
-		emu.registers['%rip'] = emu.labels[label]
 
 @add_opcode("jl")
 def jl(emu, label):
-	if emu.status["l"]:
+	emu.jump(label, l=True)
-		emu.registers['%rip'] = emu.labels[label]
 
 @add_opcode("je")
 def je(emu, label):
-	if emu.status["e"]:
+	emu.jump(label, e=True)
-		emu.registers['%rip'] = emu.labels[label]
 
 @add_opcode("jge")
 def jge(emu, label):
-	if emu.status["g"] or emu.status["e"]:
+	emu.jump(label, "or", g=True, e=True)
-		emu.registers['%rip'] = emu.labels[label]
 
 @add_opcode("jle")
 def jle(emu, label):
-	if emu.status["l"] or emu.status["e"]:
+	emu.jump(label, "or", l=True, e=True)
-		emu.registers['%rip'] = emu.labels[label]
 
 @add_opcode("jne")
 def jne(emu, label):
-	if not emu.status["e"]:
+	emu.jump(label, e=False)
-		emu.registers['%rip'] = emu.labels[label]
 
 # Unconditional Jumping
 

tests/tests.py

@@ -1,5 +1,7 @@
-import os,sys,inspect
+import os, sys, inspect
+import traceback
 sys.path.insert(1, os.path.join(sys.path[0], '..'))
+
 import infernal
 
 ################################################################################
@@ -9,16 +11,6 @@ tests = []
 def add_test(name, result, register, code):
 	tests.append((name, result, register, code))
 
-def execute_test (register, code):
-	emu = infernal.Emulator(code)
-	emu.setStack("junk...", "calling eip")
-	emu.setRegs( rip = 0, rbp = 'old bp')
-
-	for line_nr in emu:
-		pass
-
-	return emu.getVal(register)
-
 def printf (str, *args):
 	print(str.format(*args))
 
@@ -29,15 +21,32 @@ def execute_tests():
 	error_tests = 0
 	for name, result, register, code in tests:
 		total_tests += 1
+		line_nr = None
 		try:
-			output = execute_test(register, code)
+			emu = infernal.Emulator(code)
+			emu.setStack("junk...", "calling eip")
+			emu.setRegs( rip = 0, rbp = 'old bp')
+		except infernal.CodeParseException as e:
+			error_tests += 1
+			printf("Encountered error when parsing {}, at line {}: {}",
+					name, e.line_nr, e.str)
+		try:
+			for line_nr in emu:
+				pass
+			if isinstance(result, BaseException):
+				printf("Error should have happened in {}, but did not", name)
+				failed_tests += 1
+			output = emu.getVal(register)
 			if output != result:
 				failed_tests += 1
 				printf("Failed in {}. {} was {}, should be {}",
-					name, register, result, output)
+						name, register, result, output)
 		except BaseException as e:
-			error_tests += 1
+			if not isinstance(e, result):
-			printf("Encountered error in {}: {}",name,e)
+				error_tests += 1
+				printf("Encountered error in {}, at operation {}: {}",
+						name, emu.getVal('%rip'), e)
+				traceback.print_exc()
 	printf("Tests done! {}/{}.",
 		total_tests - failed_tests - error_tests, total_tests)
 	printf("{} failed, and {} encountered a python error",
@@ -60,6 +69,56 @@ movq $20, %rax
 addq %rax, %rsi
 """)
 
+################################################################################
+
+add_test("invalid comparison 1", infernal.JunkComparisonException, "None", """
+start:	movq $100, %rsp   # Set stack pointer to a random position.
+		popq %rsi		  # Move a Junk value into %rsi
+		cmpq $10, %rsi    # Do a Junk comparison, which triggers the `i` comp
+						  # virtual register.
+		jg start		  # Attempt to do a jump to the start, if (Junk-10)>0,
+						  # which makes no sense, and thus throws an error.
+""")
+
+add_test("invalid addition 1", infernal.JunkComparisonException, "None", """
+start:	movq $100, %rsp   # Set stack pointer to a random position.
+		popq %rsi		  # Move a Junk value into %rsi
+		addq %rsi, %rsp   # Adds Junk to 101, which produces Junk.
+		cmpq $10, %rsp    # Do a Junk comparison, which triggers the `i` comp
+						  # virtual register.
+		jg start		  # Attempt to do a jump to the start, if (Junk-10)>0,
+						  # which makes no sense, and thus throws an error.
+""")
+
+add_test("invalid addition 2", infernal.JunkComparisonException, "None", """
+start:	movq $100, %rsp   # Set stack pointer to a random position.
+		popq %rsi		  # Move a Junk value into %rsi
+		addq %rsp, %rsi   # Adds 101 to Junk, which produces Junk.
+		cmpq $10, %rsi    # Do a Junk comparison, which triggers the `i` comp
+						  # virtual register.
+		jg start		  # Attempt to do a jump to the start, if (Junk-10)>0,
+						  # which makes no sense, and thus throws an error.
+""")
+
+add_test("invalid subtraction 1", infernal.JunkComparisonException, "None", """
+start:	movq $100, %rsp   # Set stack pointer to a random position.
+		popq %rsi		  # Move a Junk value into %rsi
+		subq %rsi, %rsp   # Adds Junk to 101, which produces Junk.
+		cmpq $10, %rsp    # Do a Junk comparison, which triggers the `i` comp
+						  # virtual register.
+		jg start		  # Attempt to do a jump to the start, if (Junk-10)>0,
+						  # which makes no sense, and thus throws an error.
+""")
+
+add_test("invalid subtraction 2", infernal.JunkComparisonException, "None", """
+start:	movq $100, %rsp   # Set stack pointer to a random position.
+		popq %rsi		  # Move a Junk value into %rsi
+		subq %rsp, %rsi   # Adds 101 to Junk, which produces Junk.
+		cmpq $10, %rsi    # Do a Junk comparison, which triggers the `i` comp
+						  # virtual register.
+		jg start		  # Attempt to do a jump to the start, if (Junk-10)>0,
+						  # which makes no sense, and thus throws an error.
+""")
 
 ################################################################################