def last_instr(self,
start: int,
end: int,
instr,
target=None,
exact=True) -> Optional[int]:
"""
Find the last <instr> in the block from start to end.
<instr> is any python bytecode instruction or a list of opcodes
If <instr> is an opcode with a target (like a jump), a target
destination can be specified which must match precisely if exact
is True, or if exact is False, the instruction which has a target
closest to <target> will be returned.
Return index to it or None if not found.
"""
code = self.code
# Make sure requested positions do not go out of
# code bounds
if not (start >= 0 and end <= len(code)):
return None
if not isinstance(instr, list):
instr = [instr]
result_offset = None
current_distance = self.insts[-1].offset - self.insts[0].offset
extended_arg = 0
# FIXME: use self.insts rather than code[]
for offset in self.op_range(start, end):
op = code[offset]
if op == self.opc.EXTENDED_ARG:
arg = code2num(code, offset + 1) | extended_arg
extended_arg = extended_arg_val(self.opc, arg)
continue
if op in instr:
if target is None:
result_offset = offset
else:
dest = self.get_target(offset, extended_arg)
if dest == target:
current_distance = 0
result_offset = offset
elif not exact:
new_distance = abs(target - dest)
if new_distance <= current_distance:
current_distance = new_distance
result_offset = offset
pass
pass
pass
pass
extended_arg = 0
pass
return result_offset
def all_instr(self,
start,
end,
instr,
target=None,
include_beyond_target=False):
"""
Find all `instr` in the block from start to end.
`instr` is any Python opcode or a list of opcodes
If `instr` is an opcode with a target (like a jump), a target
destination can be specified which must match precisely.
Return a list with indexes to them or [] if none found.
"""
code = self.code
assert start >= 0 and end <= len(code)
try:
None in instr
except:
instr = [instr]
result = []
extended_arg = 0
for offset in self.op_range(start, end):
op = code[offset]
if op == self.opc.EXTENDED_ARG:
arg = code2num(code, offset + 1) | extended_arg
extended_arg = extended_arg_val(self.opc, arg)
continue
if op in instr:
if target is None:
result.append(offset)
else:
t = self.get_target(offset, extended_arg)
if include_beyond_target and t >= target:
result.append(offset)
elif t == target:
result.append(offset)
pass
pass
pass
extended_arg = 0
pass
return result
def parse_byte_and_args(self, byte_code, replay=False):
""" Parse 1 - 3 bytes of bytecode into
an instruction and optionally arguments.
Argument replay is used to handle breakpoints.
"""
f = self.frame
f_code = f.f_code
co_code = f_code.co_code
extended_arg = 0
# Note: There is never more than one argument.
# The list size is used to indicate whether an argument
# exists or not.
# FIMXE: remove and use int_arg as a indicator of whether
# the argument exists.
arguments = []
int_arg = None
while True:
if f.fallthrough:
if not replay:
f.f_lasti = next_offset(byte_code, self.opc, f.f_lasti)
else:
# Jump instructions must set this False.
f.fallthrough = True
offset = f.f_lasti
line_number = self.frame.linestarts.get(offset, None)
if line_number is not None:
f.f_lineno = line_number
if not replay:
byte_code = byteint(co_code[offset])
byte_name = self.opc.opname[byte_code]
arg_offset = offset + 1
arg = None
if op_has_argument(byte_code, self.opc):
if self.version >= 3.6:
int_arg = code2num(co_code, arg_offset) | extended_arg
# Note: Python 3.6.0a1 is 2, for 3.6.a3 and beyond we have 1
arg_offset += 1
if byte_code == self.opc.EXTENDED_ARG:
extended_arg = int_arg << 8
continue
else:
extended_arg = 0
else:
int_arg = (code2num(co_code, arg_offset) +
code2num(co_code, arg_offset + 1) * 256 +
extended_arg)
arg_offset += 2
if byte_code == self.opc.EXTENDED_ARG:
extended_arg = int_arg * 65536
continue
else:
extended_arg = 0
if byte_code in self.opc.CONST_OPS:
arg = f_code.co_consts[int_arg]
elif byte_code in self.opc.FREE_OPS:
if int_arg < len(f_code.co_cellvars):
arg = f_code.co_cellvars[int_arg]
else:
var_idx = int_arg - len(f.f_code.co_cellvars)
arg = f_code.co_freevars[var_idx]
elif byte_code in self.opc.NAME_OPS:
arg = f_code.co_names[int_arg]
elif byte_code in self.opc.JREL_OPS:
# Many relative jumps are conditional,
# so setting f.fallthrough is wrong.
arg = arg_offset + int_arg
elif byte_code in self.opc.JABS_OPS:
# We probably could set fallthough, since many (all?)
# of these are unconditional, but we'll make the jump do
# the work of setting.
arg = int_arg
elif byte_code in self.opc.LOCAL_OPS:
arg = f_code.co_varnames[int_arg]
else:
arg = int_arg
arguments = [arg]
break
return byte_name, byte_code, int_arg, arguments, offset, line_number
