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More if/then detection in Python 3.x

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rocky
2016-12-29 03:56:39 -05:00
parent d002c667ae
commit ed9fb64e72
2 changed files with 46 additions and 19 deletions
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65
uncompyle6/scanners/scanner3.py
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@@ -148,7 +148,7 @@ class Scanner3(Scanner):
"""
show_asm = self.show_asm if not show_asm else show_asm
# show_asm = 'after'
# show_asm = 'both'
if show_asm in ('both', 'before'):
bytecode = Bytecode(co, self.opc)
for instr in bytecode.get_instructions(co):
@@ -600,7 +600,6 @@ class Scanner3(Scanner):
parent = struct
if op == self.opc.SETUP_LOOP:
# We categorize loop types: 'for', 'while', 'while 1' with
# possibly suffixes '-loop' and '-else'
# Try to find the jump_back instruction of the loop.
@@ -618,20 +617,30 @@ class Scanner3(Scanner):
jump_back = self.last_instr(start, end, self.opc.JUMP_ABSOLUTE,
next_line_byte, False)
if jump_back and jump_back != self.prev_op[end] and self.is_jump_forward(jump_back+3):
if (code[self.prev_op[end]] == self.opc.RETURN_VALUE
or (code[self.prev_op[end]] == self.opc.POP_BLOCK
and code[self.prev_op[self.prev_op[end]]] == self.opc.RETURN_VALUE)):
jump_forward_offset = jump_back+3
return_val_offset1 = self.prev[self.prev[end]]
if (jump_back and jump_back != self.prev_op[end]
and self.is_jump_forward(jump_forward_offset)):
if (code[self.prev_op[end]] == self.opc.RETURN_VALUE or
(code[self.prev_op[end]] == self.opc.POP_BLOCK
and code[return_val_offset1] == self.opc.RETURN_VALUE)):
jump_back = None
if not jump_back: # loop suite ends in return. wtf right?
if not jump_back:
# loop suite ends in return
jump_back = self.last_instr(start, end, self.opc.RETURN_VALUE) + 1
if not jump_back:
return
jump_back += 1
if_offset = None
if code[self.prev_op[next_line_byte]] not in POP_JUMP_TF:
loop_type = 'for'
else:
if_offset = self.prev[next_line_byte]
if if_offset:
loop_type = 'while'
self.ignore_if.add(self.prev_op[next_line_byte])
self.ignore_if.add(if_offset)
else:
loop_type = 'for'
target = next_line_byte
end = jump_back + 3
else:
@@ -645,6 +654,7 @@ class Scanner3(Scanner):
elif target < offset:
self.fixed_jumps[offset] = jump_back+4
end = jump_back+4
target = self.get_target(jump_back)
if code[target] in (self.opc.FOR_ITER, self.opc.GET_ITER):
@@ -652,6 +662,7 @@ class Scanner3(Scanner):
else:
loop_type = 'while'
test = self.prev_op[next_line_byte]
if test == offset:
loop_type = 'while 1'
elif self.code[test] in op3.hasjabs+op3.hasjrel:
@@ -764,14 +775,15 @@ class Scanner3(Scanner):
if offset in self.ignore_if:
return
if (code[prev_op[rtarget]] == self.opc.JUMP_ABSOLUTE and
prev_op[rtarget] in self.stmts and
prev_op[rtarget] != offset and
prev_op[prev_op[rtarget]] != offset and
rrtarget = prev_op[rtarget]
if (code[rrtarget] == self.opc.JUMP_ABSOLUTE and
rrtarget in self.stmts and
rrtarget != offset and
prev_op[rrtarget] != offset and
not (code[rtarget] == self.opc.JUMP_ABSOLUTE and
code[rtarget+3] == self.opc.POP_BLOCK and
code[prev_op[prev_op[rtarget]]] != self.opc.JUMP_ABSOLUTE)):
rtarget = prev_op[rtarget]
code[prev_op[rrtarget]] != self.opc.JUMP_ABSOLUTE)):
rtarget = rrtarget
# Does the "jump if" jump beyond a jump op?
# That is, we have something like:
@@ -787,8 +799,7 @@ class Scanner3(Scanner):
# There are other contexts we may need to consider
# like whether the target is "END_FINALLY"
# or if the condition jump is to a forward location
if self.is_jump_forward(prev_op[rtarget]):
rrtarget = prev_op[rtarget]
if self.is_jump_forward(rrtarget):
if_end = self.get_target(rrtarget)
# If the jump target is back, we are looping
@@ -813,7 +824,13 @@ class Scanner3(Scanner):
'start': rtarget,
'end': end})
self.else_start[rtarget] = end
elif code[prev_op[rtarget]] == self.opc.RETURN_VALUE:
elif self.is_jump_back(rrtarget):
if_end = rtarget
self.structs.append({'type': 'if-then',
'start': start,
'end': rrtarget})
self.not_continue.add(prev_op[rtarget])
elif code[rrtarget] == self.opc.RETURN_VALUE:
self.structs.append({'type': 'if-then',
'start': start,
'end': rtarget})
@@ -882,6 +899,16 @@ class Scanner3(Scanner):
pass
return
def is_jump_back(self, offset):
"""
Return True if the code at offset is some sort of jump back.
That is, it is ether "JUMP_FORWARD" or an absolute jump that
goes forward.
"""
if self.code[offset] != self.opc.JUMP_ABSOLUTE:
return False
return offset > self.get_target(offset)
def next_except_jump(self, start):
"""
Return the next jump that was generated by an except SomeException: