def run(state: programState.ProgramState) -> Tuple[programState.ProgramState, Union[programState.RunError, None]]:
a, err = state.getReg(arg2)
if isinstance(arg3, str):
if err is None:
b, err = state.getReg(arg3)
else:
b, _ = state.getReg(arg3)
if b > 32:
return state, programState.RunError(f"Shift value is out of range: value must be below 33 but is {b}", programState.RunError.ErrorType.Error)
else:
b = arg3
out = a >> b
out32 = out & 0xFFFF_FFFF
if ((a >> 31) & 1) == 1: # sign-extend
out32 |= (0xFFFF_FFFF << (32 - b)) & 0xFFFF_FFFF
if b == 0:
c = state.status.C # The C flag is unaffected if the shift value is 0 - ARM docs
else:
c = bool((a >> (b-1)) & 1) # Get last bit shifted out
n = bool((out32 >> 31) & 1)
z = out32 == 0
state.setReg(arg1, out32)
state.setALUState(programState.StatusRegister(n, z, c, False))
return state, err
def run(state: programState.ProgramState) -> Tuple[programState.ProgramState, Union[programState.RunError, None]]:
a = state.getReg(arg2)
if isinstance(arg3, str):
b = state.getReg(arg3)
else:
b = arg3
# subtract one more if carry is set
if state.status.C:
b += 1
minusB = ((~b)+1) & 0xFFFFFFFF
out = a + minusB
out32 = out & 0xFFFFFFFF
bit31 = (out32 >> 31) & 1
signA = (a >> 31) & 1
signB = (minusB >> 31) & 1
v = signA == signB and signB != bit31
c = bool((out >> 32) & 1)
n = bool((out >> 31) & 1)
z = out32 == 0
state.setReg(arg1, out32)
state.setALUState(programState.StatusRegister(n, z, c, v))
return state, None
def run(state: programState.ProgramState) -> Tuple[programState.ProgramState, Union[programState.RunError, None]]:
a, err = state.getReg(arg2)
if isinstance(arg3, str):
if err is None:
b, err = state.getReg(arg3)
else:
b, _ = state.getReg(arg3)
else:
b = arg3 & 0XFFFFFFFF
minusB = ((~b)+1) & 0xFFFFFFFF
out = a + minusB
out32 = out & 0xFFFFFFFF
bit31 = (out32 >> 31) & 1
signA = (a >> 31) & 1
signB = (minusB >> 31) & 1
v = signA == signB and signB != bit31
c = bool((out >> 32) & 1)
n = bool((out >> 31) & 1)
z = out32 == 0
state.setReg(arg1, out32)
state.setALUState(programState.StatusRegister(n, z, c, v))
return state, err
def executeInstruction(
node: nodes.InstructionNode, state: programState.ProgramState,
fileName: str,
lines: List[str]) -> Tuple[programState.ProgramState, bool]:
if isinstance(node, nodes.InstructionNode):
# Execute the instruction
state, err = node.function(state)
# Exception handling
if err is not None:
if isinstance(err, programState.RunError):
if err.errorType == programState.RunError.ErrorType.Error:
print(generateStacktrace(state, err, fileName, lines))
return state, False
elif err.errorType == programState.RunError.ErrorType.Warning:
if node not in warningNodes:
print(generateStacktrace(state, err, fileName, lines))
warningNodes.append(node)
elif isinstance(err, programState.StopProgram):
return state, False
# Set a flag in the ProgramState when a subroutine returned. This way the stacktrace generator knows to not print a stacktrace element for the link register
pc, _ = state.getReg("PC")
if pc == state.getReg("LR")[0]:
state.hasReturned = True
# increment the program counter
state.setReg("PC", pc + 4)
return state, True
else:
if isinstance(node, programState.RunError):
print(generateStacktrace(state, node, fileName, lines))
return state, False
def movReg(
state: programState.ProgramState
) -> Tuple[programState.ProgramState, Union[programState.RunError,
None]]:
value, err = state.getReg(src.contents)
if halfWord:
if signed:
if (value & 0b1000_0000_0000_0000
) == 0b1000_0000_0000_0000:
value |= 0xFFFF_0000 # Set upper half-word when sign bit is set
else:
value &= 0xFFFF
else:
value &= 0xFFFF
else:
if signed:
if (value & 0b1000_0000) == 0b1000_0000:
value |= 0xFFFF_FF00 # Set upper three bytes when sign bit is set
else:
value &= 0xFF
else:
value &= 0xFF
state.setReg(dest.contents, value)
return state, err
def run(state: programState.ProgramState) -> Tuple[programState.ProgramState, Union[programState.RunError, None]]:
a, err = state.getReg(arg2)
if isinstance(arg3, str):
if err is None:
b, err = state.getReg(arg3)
else:
b, _ = state.getReg(arg3)
else:
b = arg3 & 0XFFFFFFFF
# subtract one more if carry is set
if state.status.C:
b += 1
out = a + b
out32 = out & 0xFFFFFFFF
bit31 = (out32 >> 31) & 1
signA = (a >> 31) & 1
signB = (b >> 31) & 1
v = signA == signB and signB != bit31
c = bool((out >> 32) & 1)
n = bool((out >> 31) & 1)
z = out32 == 0
state.setReg(arg1, out32)
state.setALUState(programState.StatusRegister(n, z, c, v))
return state, err
def run(state: programState.ProgramState) -> Tuple[programState.ProgramState, Union[programState.RunError, None]]:
a, err = state.getReg(arg2)
if isinstance(arg3, str):
if err is None:
b, err = state.getReg(arg3)
else:
b, _ = state.getReg(arg3)
else:
b = arg3 & 0XFFFFFFFF
bMod32 = b & 31
out = (a >> bMod32) | (a << (32 - bMod32))
out32 = out & 0xFFFF_FFFF
if b == 0:
c = state.status.C # The C flag is unaffected if the shift value is 0 - ARM docs
else:
c = bool((a >> (bMod32-1)) & 1) # Get last bit shifted out
n = bool((out32 >> 31) & 1)
z = out32 == 0
state.setReg(arg1, out32)
state.setALUState(programState.StatusRegister(n, z, c, False))
return state, err
def subroutine_print_int(state: programState.ProgramState) -> Tuple[programState.ProgramState, Union[programState.RunError, None]]:
# print char
r0 = state.getReg("R0")
print(int(r0), end='\n')
# mov PC, LR
lr = state.getReg("LR")
state.setReg("PC", lr)
return state, None
def movReg(
state: programState.ProgramState
) -> Tuple[programState.ProgramState, Union[programState.RunError,
None]]:
value, err = state.getReg(src.contents)
if invert:
value = value ^ 0xFFFF_FFFF
state.setReg(dest.contents, value)
return state, err
def movImmed(
state: programState.ProgramState
) -> Tuple[programState.ProgramState, Union[programState.RunError,
None]]:
if invert:
value = src.value ^ 0xFFFF_FFFF
else:
value = src.value
state.setReg(dest.contents, value)
return state, None
def ldrLabel(
state: programState.ProgramState
) -> Tuple[programState.ProgramState, Union[programState.RunError,
None]]:
val: Union[int, programState.RunError] = state.getLabelAddress(
label.label)
if isinstance(val, programState.RunError):
return state, val
else:
state.setReg(dest.contents, val)
return state, None
def subroutine_print_int(
state: programState.ProgramState
) -> Tuple[programState.ProgramState, Union[programState.RunError, None]]:
# print char
r0, err = state.getReg("R0")
print(int(r0), end='\n')
# mov PC, LR
lr, _ = state.getReg("LR")
state.setReg("PC", lr)
state.lowRegDirtyFlags = [True, True, True, True]
return state, err
def branchToLabel(state: programState.ProgramState, label: str) -> Tuple[programState.ProgramState, Union[programState.RunError, None]]:
# Save return address in LR
state.setReg("LR", state.getReg("PC"))
address: Union[int, programState.RunError] = state.getLabelAddress(label)
if isinstance(address, programState.RunError):
return state, programState.RunError(f"Unknown startup label: {label}", programState.RunError.ErrorType.Error)
else:
# Subtract 4 because we will add 4 to the address later in the run loop and we need to start at address and not address+4
state.setReg("PC", address - 4)
state.hasReturned = False
return state, None
def branchTo(
state: programState.ProgramState
) -> Tuple[programState.ProgramState, Union[programState.RunError,
None]]:
if link:
# Save return address in LR
state.setReg("LR", state.getReg("PC")[0])
address, err = state.getReg(label.contents)
# Subtract 4 because we will add 4 to the address later in the run loop and we need to start at address and not address+4
state.setReg("PC", address - 4)
state.hasReturned = False
return state, err
def run(state: programState.ProgramState) -> Tuple[programState.ProgramState, Union[programState.RunError, None]]:
a = state.getReg(arg2)
b = state.getReg(arg3)
out32 = (a * b) & 0xFFFFFFFF
n = bool((out32 >> 31) & 1)
z = out32 == 0
state.setReg(arg1, out32)
state.setALUState(programState.StatusRegister(n, z, state.status.C, state.status.V))
return state, None
def branchTo(
state: programState.ProgramState
) -> Tuple[programState.ProgramState, Union[programState.RunError,
None]]:
if condition(state.status):
address: Union[int,
programState.RunError] = state.getLabelAddress(
label.contents)
if isinstance(address, programState.RunError):
return state, address
else:
# Subtract 4 because we will add 4 to the address later in the run loop and we need to start at address and not address+4
state.setReg("PC", address - 4)
return state, None
def run(state: programState.ProgramState) -> Tuple[programState.ProgramState, Union[programState.RunError, None]]:
a = state.getReg(arg2)
if isinstance(arg3, str):
b = state.getReg(arg3)
else:
b = arg3 & 0XFFFFFFFF
out = a & (b ^ 0xFFFF_FFFF) # out = a & ! b
n = bool((out >> 31) & 1)
z = out == 0
state.setReg(arg1, out)
state.setALUState(programState.StatusRegister(n, z, False, False))
return state, None
def pop(state: programState.ProgramState) -> Tuple[programState.ProgramState, Union[programState.RunError, None]]:
if len(regs) == 0:
return state, None
# head, *tail = registers
address = state.getReg("SP")
# check address is in 0...stacksize
if address > (state.getLabelAddress("__STACKSIZE")) or address < 0:
return state, programState.RunError("All stack entries have been pop'ed already", programState.RunError.ErrorType.Error)
for reg in regs:
err = state.loadRegister(address, 32, False, reg)
address += 4
if err is not None:
return state, err
state.setReg("SP", address)
return state, None
def push(state: programState.ProgramState) -> Tuple[programState.ProgramState, Union[programState.RunError, None]]:
if len(regs) == 0:
return state, None
# head, *tail = registers
address = state.getReg("SP")
# check address is in 0...stacksize
if address > (state.getLabelAddress("__STACKSIZE")) or address < 0:
return state, programState.RunError("Stack overflow", programState.RunError.ErrorType.Error)
for reg in regs:
address -= 4
err = state.storeRegister(address, reg, 32)
if err is not None:
return state, err
state.setReg("SP", address)
return state, None
def branchTo(
state: programState.ProgramState
) -> Tuple[programState.ProgramState, Union[programState.RunError,
None]]:
# Save return address in LR
pc, _ = state.getReg("PC")
state.setReg("LR", pc)
address: Union[int, programState.RunError] = state.getLabelAddress(
label.contents)
if isinstance(address, programState.RunError):
return state, address
else:
# Subtract 4 because we will add 4 to the address later in the run loop and we need to start at address and not address+4
state.setReg("PC", address - 4)
state.hasReturned = False
return state, None
def run(state: programState.ProgramState) -> Tuple[programState.ProgramState, Union[programState.RunError, None]]:
a = state.getReg(arg2)
if isinstance(arg3, str):
b = state.getReg(arg3)
if b > 31:
return state, programState.RunError(f"Shift value is out of range: value must be below 32 but is {b}", programState.RunError.ErrorType.Error)
else:
b = arg3
out = a << b
out32 = out & 0xFFFF_FFFF
if b == 0:
c = state.status.C # The C flag is unaffected if the shift value is 0 - ARM docs
else:
c = bool((out >> 32) & 1) # Get the last bit shifted out
n = bool((out32 >> 31) & 1)
z = out32 == 0
state.setReg(arg1, out32)
state.setALUState(programState.StatusRegister(n, z, c, False))
return state, None
def ldrImmed(
state: programState.ProgramState
) -> Tuple[programState.ProgramState, Union[programState.RunError,
None]]:
state.setReg(dest.contents, value)
return state, None