Files
python-uncompyle6/uncompyle6/parsers/reducecheck/or_check.py
rocky badfe5456f Track "or" grammar changes...
Remove re deprecation warning
2020-04-16 15:25:42 -04:00

41 lines
1.7 KiB
Python

# Copyright (c) 2020 Rocky Bernstein
ASSERT_OPS = frozenset(["LOAD_ASSERT", "RAISE_VARARGS_1"])
def or_check(self, lhs, n, rule, ast, tokens, first, last):
if rule == ("or", ("expr_jt", "expr")):
if tokens[last] in ASSERT_OPS or tokens[last-1] in ASSERT_OPS:
return True
# The following test is be the most accurate. It prevents "or" from being
# mistake for part of an "assert".
# There one might conceivably be "expr or AssertionError" code, but the
# likelihood of that is vanishingly small.
# The below then is useful until we get better control-flow analysis.
# Note it is too hard in the scanner right nowto turn the LOAD_GLOBAL into
# int LOAD_ASSERT, however in 3.9ish code generation does this by default.
load_global = tokens[last - 1]
if load_global == "LOAD_GLOBAL" and load_global.attr == "AssertionError":
return True
first_offset = tokens[first].off2int()
jmp_true_target = ast[0][1][0].attr
jmp_true_target < first_offset
if jmp_true_target < first_offset:
return False
jmp_false = tokens[last]
# If the jmp is backwards
if jmp_false == "POP_JUMP_IF_FALSE":
jmp_false_offset = jmp_false.off2int()
if jmp_false.attr < jmp_false_offset:
# For a backwards loop, well compare to the instruction *after*
# then POP_JUMP...
jmp_false = tokens[last + 1]
return not (
(jmp_false_offset <= jmp_true_target <= jmp_false_offset + 2)
or jmp_true_target < tokens[first].off2int()
)
return False