def op_range(self, start, end):
"""
Iterate through positions of opcodes, skipping
arguments.
"""
while start < end:
yield start
start += op_size(self.code[start], self.opc)
def build_prev_op(self):
"""
Compose 'list-map' which allows to jump to previous
op, given offset of current op as index.
"""
code = self.code
codelen = len(code)
# 2.x uses prev 3.x uses prev_op. Sigh
# Until we get this sorted out.
self.prev = self.prev_op = [0]
for offset in self.op_range(0, codelen):
op = code[offset]
for _ in range(op_size(op, self.opc)):
self.prev_op.append(offset)
def detect_control_flow(self, offset, targets):
"""
Detect structures and their boundaries to fix optimized jumps
Python 3.0 is more like Python 2.6 than it is Python 3.x.
So we have a special routine here.
"""
code = self.code
op = code[offset]
# Detect parent structure
parent = self.structs[0]
start = parent['start']
end = parent['end']
# Pick inner-most parent for our offset
for struct in self.structs:
current_start = struct['start']
current_end = struct['end']
if ((current_start <= offset < current_end)
and (current_start >= start and current_end <= end)):
start = current_start
end = current_end
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.
# It could be a return instruction.
start = offset + 3
target = self.get_target(offset)
end = self.restrict_to_parent(target, parent)
self.setup_loop_targets[offset] = target
self.setup_loops[target] = offset
if target != end:
self.fixed_jumps[offset] = end
(line_no, next_line_byte) = self.lines[offset]
jump_back = self.last_instr(start, end, self.opc.JUMP_ABSOLUTE,
next_line_byte, False)
if jump_back:
jump_forward_offset = jump_back + 3
else:
jump_forward_offset = None
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
jump_back = self.last_instr(start, end, self.opc.RETURN_VALUE)
if not jump_back:
return
jump_back += 2
if_offset = None
if code[self.prev_op[next_line_byte]] not in JUMP_TF:
if_offset = self.prev[next_line_byte]
if if_offset:
loop_type = 'while'
self.ignore_if.add(if_offset)
else:
loop_type = 'for'
target = next_line_byte
end = jump_back + 3
else:
if self.get_target(jump_back) >= next_line_byte:
jump_back = self.last_instr(start, end,
self.opc.JUMP_ABSOLUTE, start,
False)
if end > jump_back + 4 and self.is_jump_forward(end):
if self.is_jump_forward(jump_back + 4):
if self.get_target(jump_back +
4) == self.get_target(end):
self.fixed_jumps[offset] = jump_back + 4
end = jump_back + 4
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):
loop_type = 'for'
else:
loop_type = 'while'
test = self.prev_op[next_line_byte]
if test == offset:
loop_type = 'while 1'
elif self.code[test] in opc.hasjabs + opc.hasjrel:
self.ignore_if.add(test)
test_target = self.get_target(test)
if test_target > (jump_back + 3):
jump_back = test_target
self.not_continue.add(jump_back)
self.loops.append(target)
self.structs.append({
'type': loop_type + '-loop',
'start': target,
'end': jump_back
})
if jump_back + 3 != end:
self.structs.append({
'type': loop_type + '-else',
'start': jump_back + 3,
'end': end
})
elif op in JUMP_TF:
start = offset + op_size(op, self.opc)
target = self.get_target(offset)
rtarget = self.restrict_to_parent(target, parent)
prev_op = self.prev_op
# Do not let jump to go out of parent struct bounds
if target != rtarget and parent['type'] == 'and/or':
self.fixed_jumps[offset] = rtarget
return
# Does this jump to right after another conditional jump that is
# not myself? If so, it's part of a larger conditional.
# rocky: if we have a conditional jump to the next instruction, then
# possibly I am "skipping over" a "pass" or null statement.
if ((code[prev_op[target]] in self.pop_jump_if_pop)
and (target > offset) and prev_op[target] != offset):
self.fixed_jumps[offset] = prev_op[target]
self.structs.append({
'type': 'and/or',
'start': start,
'end': prev_op[target]
})
return
# The op offset just before the target jump offset is important
# in making a determination of what we have. Save that.
pre_rtarget = prev_op[rtarget]
# Is it an "and" inside an "if" or "while" block
if op == opc.JUMP_IF_FALSE:
# Search for another JUMP_IF_FALSE targetting the same op,
# in current statement, starting from current offset, and filter
# everything inside inner 'or' jumps and midline ifs
match = self.rem_or(start, self.next_stmt[offset],
opc.JUMP_IF_FALSE, target)
# If we still have any offsets in set, start working on it
if match:
is_jump_forward = self.is_jump_forward(pre_rtarget)
if (is_jump_forward and pre_rtarget not in self.stmts
and self.restrict_to_parent(
self.get_target(pre_rtarget),
parent) == rtarget):
if (code[prev_op[pre_rtarget]]
== self.opc.JUMP_ABSOLUTE
and self.remove_mid_line_ifs([offset])
and target == self.get_target(
prev_op[pre_rtarget]) and
(prev_op[pre_rtarget] not in self.stmts
or self.get_target(prev_op[pre_rtarget]) >
prev_op[pre_rtarget]) and 1 == len(
self.remove_mid_line_ifs(
self.rem_or(start, prev_op[pre_rtarget],
JUMP_TF, target)))):
pass
elif (code[prev_op[pre_rtarget]]
== self.opc.RETURN_VALUE
and self.remove_mid_line_ifs([offset])
and 1 == (len(
set(
self.remove_mid_line_ifs(
self.rem_or(start,
prev_op[pre_rtarget],
JUMP_TF, target)))
| set(
self.remove_mid_line_ifs(
self.rem_or(
start, prev_op[pre_rtarget],
(opc.JUMP_IF_FALSE,
opc.JUMP_IF_TRUE,
opc.JUMP_ABSOLUTE
), pre_rtarget, True)))))):
pass
else:
fix = None
jump_ifs = self.all_instr(start,
self.next_stmt[offset],
opc.JUMP_IF_FALSE)
last_jump_good = True
for j in jump_ifs:
if target == self.get_target(j):
if self.lines[
j].next == j + 3 and last_jump_good:
fix = j
break
else:
last_jump_good = False
self.fixed_jumps[offset] = fix or match[-1]
return
else:
self.fixed_jumps[offset] = match[-1]
return
# op == JUMP_IF_TRUE
else:
next = self.next_stmt[offset]
if prev_op[next] == offset:
pass
elif self.is_jump_forward(next) and target == self.get_target(
next):
if code[prev_op[next]] == opc.JUMP_IF_FALSE:
if (code[next] == self.opc.JUMP_FORWARD
or target != rtarget
or code[prev_op[pre_rtarget]]
not in (self.opc.JUMP_ABSOLUTE,
self.opc.RETURN_VALUE)):
self.fixed_jumps[offset] = prev_op[next]
return
elif (code[next] == self.opc.JUMP_ABSOLUTE
and self.is_jump_forward(target)
and self.get_target(target) == self.get_target(next)):
self.fixed_jumps[offset] = prev_op[next]
return
# Don't add a struct for a while test, it's already taken care of
if offset in self.ignore_if:
return
if (code[pre_rtarget] == self.opc.JUMP_ABSOLUTE
and pre_rtarget in self.stmts and pre_rtarget != offset
and prev_op[pre_rtarget] != offset
and not (code[rtarget] == self.opc.JUMP_ABSOLUTE
and code[rtarget + 3] == self.opc.POP_BLOCK
and code[prev_op[pre_rtarget]] !=
self.opc.JUMP_ABSOLUTE)):
rtarget = pre_rtarget
# Does the "jump if" jump beyond a jump op?
# That is, we have something like:
# JUMP_IF_FALSE HERE
# ...
# JUMP_FORWARD
# HERE:
#
# If so, this can be block inside an "if" statement
# or a conditional assignment like:
# x = 1 if x else 2
#
# 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(pre_rtarget):
if_end = self.get_target(pre_rtarget)
# If the jump target is back, we are looping
if (if_end < pre_rtarget
and (code[prev_op[if_end]] == self.opc.SETUP_LOOP)):
if (if_end > start):
return
end = self.restrict_to_parent(if_end, parent)
self.structs.append({
'type': 'if-then',
'start': start,
'end': pre_rtarget
})
self.not_continue.add(pre_rtarget)
# if rtarget < end and (
# code[rtarget] not in (self.opc.END_FINALLY,
# self.opc.JUMP_ABSOLUTE) and
# code[prev_op[pre_rtarget]] not in (self.opc.POP_EXCEPT,
# self.opc.END_FINALLY)):
# self.structs.append({'type': 'else',
# 'start': rtarget,
# 'end': end})
# self.else_start[rtarget] = end
elif self.is_jump_back(pre_rtarget):
if_end = rtarget
self.structs.append({
'type': 'if-then',
'start': start,
'end': pre_rtarget
})
self.not_continue.add(pre_rtarget)
elif code[pre_rtarget] in (self.opc.RETURN_VALUE,
self.opc.BREAK_LOOP):
self.structs.append({
'type': 'if-then',
'start': start,
'end': rtarget
})
# It is important to distingish if this return is inside some sort
# except block return
jump_prev = prev_op[offset]
if self.is_pypy and code[jump_prev] == self.opc.COMPARE_OP:
if self.opc.cmp_op[code[jump_prev +
1]] == 'exception match':
return
if self.version >= 3.5:
# Python 3.5 may remove as dead code a JUMP
# instruction after a RETURN_VALUE. So we check
# based on seeing SETUP_EXCEPT various places.
if code[rtarget] == self.opc.SETUP_EXCEPT:
return
# Check that next instruction after pops and jump is
# not from SETUP_EXCEPT
next_op = rtarget
if code[next_op] == self.opc.POP_BLOCK:
next_op += op_size(self.code[next_op], self.opc)
if code[next_op] == self.opc.JUMP_ABSOLUTE:
next_op += op_size(self.code[next_op], self.opc)
if next_op in targets:
for try_op in targets[next_op]:
come_from_op = code[try_op]
if come_from_op == self.opc.SETUP_EXCEPT:
return
pass
pass
if code[pre_rtarget] == self.opc.RETURN_VALUE:
self.return_end_ifs.add(pre_rtarget)
else:
self.fixed_jumps[offset] = rtarget
self.not_continue.add(pre_rtarget)
elif op == self.opc.SETUP_EXCEPT:
target = self.get_target(offset)
end = self.restrict_to_parent(target, parent)
self.fixed_jumps[offset] = end
elif op == self.opc.SETUP_FINALLY:
target = self.get_target(offset)
end = self.restrict_to_parent(target, parent)
self.fixed_jumps[offset] = end
elif op in self.jump_if_pop:
target = self.get_target(offset)
if target > offset:
unop_target = self.last_instr(offset, target,
self.opc.JUMP_FORWARD, target)
if unop_target and code[unop_target + 3] != self.opc.ROT_TWO:
self.fixed_jumps[offset] = unop_target
else:
self.fixed_jumps[offset] = self.restrict_to_parent(
target, parent)
pass
pass
elif self.version >= 3.5:
# 3.5+ has Jump optimization which too often causes RETURN_VALUE to get
# misclassified as RETURN_END_IF. Handle that here.
# In RETURN_VALUE, JUMP_ABSOLUTE, RETURN_VALUE is never RETURN_END_IF
if op == self.opc.RETURN_VALUE:
if (offset + 1 < len(code)
and code[offset + 1] == self.opc.JUMP_ABSOLUTE
and offset in self.return_end_ifs):
self.return_end_ifs.remove(offset)
pass
pass
elif op == self.opc.JUMP_FORWARD:
# If we have:
# JUMP_FORWARD x, [non-jump, insns], RETURN_VALUE, x:
# then RETURN_VALUE is not RETURN_END_IF
rtarget = self.get_target(offset)
rtarget_prev = self.prev[rtarget]
if (code[rtarget_prev] == self.opc.RETURN_VALUE
and rtarget_prev in self.return_end_ifs):
i = rtarget_prev
while i != offset:
if code[i] in [opc.JUMP_FORWARD, opc.JUMP_ABSOLUTE]:
return
i = self.prev[i]
self.return_end_ifs.remove(rtarget_prev)
pass
return
def detect_control_flow(self, offset, op):
"""
Detect type of block structures and their boundaries to fix optimized jumps
in python2.3+
"""
code = self.code
# Detect parent structure
parent = self.structs[0]
start = parent['start']
end = parent['end']
# Pick inner-most parent for our offset
for struct in self.structs:
current_start = struct['start']
current_end = struct['end']
if ((current_start <= offset < current_end)
and (current_start >= start and current_end <= end)):
start = current_start
end = current_end
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.
# It could be a return instruction.
start = offset + 3
target = self.get_target(offset, op)
end = self.restrict_to_parent(target, parent)
self.setup_loop_targets[offset] = target
self.setup_loops[target] = offset
if target != end:
self.fixed_jumps[offset] = end
(line_no, next_line_byte) = self.lines[offset]
jump_back = self.last_instr(start, end, self.opc.JUMP_ABSOLUTE,
next_line_byte, False)
if jump_back:
# Account for the fact that < 2.7 has an explicit
# POP_TOP instruction in the equivalate POP_JUMP_IF
# construct
if self.version < 2.7:
jump_forward_offset = jump_back + 4
return_val_offset1 = self.prev[self.prev[self.prev[end]]]
# Is jump back really "back"?
jump_target = self.get_target(jump_back, code[jump_back])
if (jump_target > jump_back or code[jump_back + 3] in [
self.opc.JUMP_FORWARD, self.opc.JUMP_ABSOLUTE
]):
jump_back = None
pass
else:
jump_forward_offset = jump_back + 3
return_val_offset1 = self.prev[self.prev[end]]
if (jump_back and jump_back != self.prev[end]
and code[jump_forward_offset] in self.jump_forward):
if (code[self.prev[end]] == self.opc.RETURN_VALUE or
(code[self.prev[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
# scanner26 of wbiti had:
# jump_back = self.last_instr(start, end, self.opc.JUMP_ABSOLUTE, start, False)
jump_back = self.last_instr(start, end, self.opc.RETURN_VALUE)
if not jump_back:
return
jump_back += 1
if_offset = None
if self.version < 2.7:
# Look for JUMP_IF POP_TOP ...
if (code[self.prev[next_line_byte]] == self.opc.POP_TOP
and (code[self.prev[self.prev[next_line_byte]]]
in self.pop_jump_if)):
if_offset = self.prev[self.prev[next_line_byte]]
elif code[self.prev[next_line_byte]] in self.pop_jump_if:
# Look for POP_JUMP_IF ...
if_offset = self.prev[next_line_byte]
if if_offset:
loop_type = 'while'
self.ignore_if.add(if_offset)
if self.version < 2.7 and (code[self.prev[jump_back]]
== self.opc.RETURN_VALUE):
self.ignore_if.add(self.prev[jump_back])
pass
pass
else:
loop_type = 'for'
target = next_line_byte
end = jump_back + 3
else:
if self.get_target(jump_back) >= next_line_byte:
jump_back = self.last_instr(start, end,
self.opc.JUMP_ABSOLUTE, start,
False)
if end > jump_back + 4 and code[end] in self.jump_forward:
if code[jump_back + 4] in self.jump_forward:
if self.get_target(jump_back +
4) == self.get_target(end):
self.fixed_jumps[offset] = jump_back + 4
end = jump_back + 4
elif target < offset:
self.fixed_jumps[offset] = jump_back + 4
end = jump_back + 4
target = self.get_target(jump_back, self.opc.JUMP_ABSOLUTE)
if (self.version > 2.1 and code[target]
in (self.opc.FOR_ITER, self.opc.GET_ITER)):
loop_type = 'for'
else:
loop_type = 'while'
if (self.version < 2.7
and self.code[self.prev[next_line_byte]]
== self.opc.POP_TOP):
test = self.prev[self.prev[next_line_byte]]
else:
test = self.prev[next_line_byte]
if test == offset:
loop_type = 'while 1'
elif self.code[test] in self.opc.JUMP_OPs:
self.ignore_if.add(test)
test_target = self.get_target(test)
if test_target > (jump_back + 3):
jump_back = test_target
self.not_continue.add(jump_back)
self.loops.append(target)
self.structs.append({
'type': loop_type + '-loop',
'start': target,
'end': jump_back
})
if jump_back + 3 != end:
self.structs.append({
'type': loop_type + '-else',
'start': jump_back + 3,
'end': end
})
elif op == self.opc.SETUP_EXCEPT:
start = offset + op_size(op, self.opc)
target = self.get_target(offset, op)
end = self.restrict_to_parent(target, parent)
if target != end:
self.fixed_jumps[offset] = end
# print target, end, parent
# Add the try block
self.structs.append({
'type': 'try',
'start': start - 3,
'end': end - 4
})
# Now isolate the except and else blocks
end_else = start_else = self.get_target(self.prev[end])
end_finally_offset = end
setup_except_nest = 0
while end_finally_offset < len(self.code):
if self.code[end_finally_offset] == self.opc.END_FINALLY:
if setup_except_nest == 0:
break
else:
setup_except_nest -= 1
elif self.code[end_finally_offset] == self.opc.SETUP_EXCEPT:
setup_except_nest += 1
end_finally_offset += op_size(code[end_finally_offset],
self.opc)
pass
# Add the except blocks
i = end
while i < len(self.code) and i < end_finally_offset:
jmp = self.next_except_jump(i)
if jmp is None: # check
i = self.next_stmt[i]
continue
if self.code[jmp] == self.opc.RETURN_VALUE:
self.structs.append({
'type': 'except',
'start': i,
'end': jmp + 1
})
i = jmp + 1
else:
target = self.get_target(jmp)
if target != start_else:
end_else = self.get_target(jmp)
if self.code[jmp] == self.opc.JUMP_FORWARD:
if self.version <= 2.6:
self.fixed_jumps[jmp] = target
else:
self.fixed_jumps[jmp] = -1
self.structs.append({
'type': 'except',
'start': i,
'end': jmp
})
i = jmp + 3
# Add the try-else block
if end_else != start_else:
r_end_else = self.restrict_to_parent(end_else, parent)
# May be able to drop the 2.7 test.
if self.version == 2.7:
self.structs.append({
'type': 'try-else',
'start': i + 1,
'end': r_end_else
})
self.fixed_jumps[i] = r_end_else
else:
self.fixed_jumps[i] = i + 1
elif op in self.pop_jump_if:
target = self.get_target(offset, op)
rtarget = self.restrict_to_parent(target, parent)
# Do not let jump to go out of parent struct bounds
if target != rtarget and parent['type'] == 'and/or':
self.fixed_jumps[offset] = rtarget
return
jump_if_offset = offset
start = offset + 3
pre = self.prev
# Does this jump to right after another conditional jump that is
# not myself? If so, it's part of a larger conditional.
# rocky: if we have a conditional jump to the next instruction, then
# possibly I am "skipping over" a "pass" or null statement.
if self.version < 2.7:
op_testset = set([
self.opc.POP_TOP, self.opc.JUMP_IF_TRUE,
self.opc.JUMP_IF_FALSE
])
else:
op_testset = self.pop_jump_if_or_pop | self.pop_jump_if
if (code[pre[target]] in op_testset and (target > offset)):
self.fixed_jumps[offset] = pre[target]
self.structs.append({
'type': 'and/or',
'start': start,
'end': pre[target]
})
return
# The op offset just before the target jump offset is important
# in making a determination of what we have. Save that.
pre_rtarget = pre[rtarget]
# Is it an "and" inside an "if" or "while" block
if op == self.opc.PJIF:
# Search for other POP_JUMP_IF_FALSE targetting the same op,
# in current statement, starting from current offset, and filter
# everything inside inner 'or' jumps and midline ifs
match = self.rem_or(start, self.next_stmt[offset],
self.opc.PJIF, target)
# If we still have any offsets in set, start working on it
if match:
if code[pre_rtarget] in self.jump_forward \
and pre_rtarget not in self.stmts \
and self.restrict_to_parent(self.get_target(pre_rtarget), parent) == rtarget:
if code[pre[pre_rtarget]] == self.opc.JUMP_ABSOLUTE \
and self.remove_mid_line_ifs([offset]) \
and target == self.get_target(pre[pre_rtarget]) \
and (pre[pre_rtarget] not in self.stmts or self.get_target(pre[pre_rtarget]) > pre[pre_rtarget])\
and 1 == len(self.remove_mid_line_ifs(self.rem_or(start, pre[pre_rtarget], self.pop_jump_if, target))):
pass
elif code[pre[pre_rtarget]] == self.opc.RETURN_VALUE \
and self.remove_mid_line_ifs([offset]) \
and 1 == (len(set(self.remove_mid_line_ifs(self.rem_or(start,
pre[pre_rtarget],
self.pop_jump_if, target)))
| set(self.remove_mid_line_ifs(self.rem_or(start, pre[pre_rtarget],
(self.opc.PJIF, self.opc.PJIT, self.opc.JUMP_ABSOLUTE), pre_rtarget, True))))):
pass
else:
fix = None
jump_ifs = self.all_instr(start,
self.next_stmt[offset],
self.opc.PJIF)
last_jump_good = True
for j in jump_ifs:
if target == self.get_target(j):
if self.lines[
j].next == j + 3 and last_jump_good:
fix = j
break
else:
last_jump_good = False
self.fixed_jumps[offset] = fix or match[-1]
return
else:
if (self.version < 2.7 and parent['type']
in ('root', 'for-loop', 'if-then', 'else',
'try')):
self.fixed_jumps[offset] = rtarget
else:
# note test for < 2.7 might be superflous although informative
# for 2.7 a different branch is taken and the below code is handled
# under: elif op in self.pop_jump_if_or_pop
# below
self.fixed_jumps[offset] = match[-1]
return
else: # op != self.opc.PJIT
if self.version < 2.7 and code[offset + 3] == self.opc.POP_TOP:
assert_offset = offset + 4
else:
assert_offset = offset + 3
if (assert_offset) in self.load_asserts:
if code[pre_rtarget] == self.opc.RAISE_VARARGS:
return
self.load_asserts.remove(assert_offset)
next = self.next_stmt[offset]
if pre[next] == offset:
pass
elif code[
next] in self.jump_forward and target == self.get_target(
next):
if code[pre[next]] == self.opc.PJIF:
if code[next] == self.opc.JUMP_FORWARD or target != rtarget or code[
pre[pre_rtarget]] not in (
self.opc.JUMP_ABSOLUTE,
self.opc.RETURN_VALUE):
self.fixed_jumps[offset] = pre[next]
return
elif code[next] == self.opc.JUMP_ABSOLUTE and code[
target] in self.jump_forward:
next_target = self.get_target(next)
if self.get_target(target) == next_target:
self.fixed_jumps[offset] = pre[next]
return
elif code[
next_target] in self.jump_forward and self.get_target(
next_target) == self.get_target(target):
self.fixed_jumps[offset] = pre[next]
return
# don't add a struct for a while test, it's already taken care of
if offset in self.ignore_if:
return
if self.version == 2.7:
if code[pre_rtarget] == self.opc.JUMP_ABSOLUTE and pre_rtarget in self.stmts \
and pre_rtarget != offset and pre[pre_rtarget] != offset:
if code[rtarget] == self.opc.JUMP_ABSOLUTE and code[
rtarget + 3] == self.opc.POP_BLOCK:
if code[pre[pre_rtarget]] != self.opc.JUMP_ABSOLUTE:
pass
elif self.get_target(pre[pre_rtarget]) != target:
pass
else:
rtarget = pre_rtarget
else:
rtarget = pre_rtarget
# Does the "jump if" jump beyond a jump op?
# That is, we have something like:
# POP_JUMP_IF_FALSE HERE
# ...
# JUMP_FORWARD
# HERE:
#
# If so, this can be block inside an "if" statement
# or a conditional assignment like:
# x = 1 if x else 2
#
# 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
code_pre_rtarget = code[pre_rtarget]
if code_pre_rtarget in self.jump_forward:
if_end = self.get_target(pre_rtarget)
# Is this a loop and not an "if" statment?
if (if_end < pre_rtarget) and (pre[if_end]
in self.setup_loop_targets):
if (if_end > start):
return
else:
# We still have the case in 2.7 that the next instruction
# is a jump to a SETUP_LOOP target.
next_offset = target + op_size(self.code[target],
self.opc)
next_op = self.code[next_offset]
if self.op_name(next_op) == 'JUMP_FORWARD':
jump_target = self.get_target(next_offset, next_op)
if jump_target in self.setup_loops:
self.structs.append({
'type': 'while-loop',
'start': jump_if_offset,
'end': jump_target
})
self.fixed_jumps[jump_if_offset] = jump_target
return
end = self.restrict_to_parent(if_end, parent)
if_then_maybe = None
if 2.2 <= self.version <= 2.6:
# Take the JUMP_IF target. In an "if/then", it will be
# a POP_TOP instruction and the instruction before it
# will be a JUMP_FORWARD to just after the POP_TOP.
# For example:
# Good:
# 3 JUMP_IF_FALSE 33 'to 39'
# ..
# 36 JUMP_FORWARD 1 'to 40'
# 39 POP_TOP
# 40 ...
# example:
# BAD (is an "and"):
# 28 JUMP_IF_FALSE 4 'to 35'
# ...
# 32 JUMP_ABSOLUTE 40 'to 40' # should be 36 or there should
# # be a COME_FROM at the pop top
# # before 40 to 35
# 35 POP_TOP
# 36 ...
# 39 POP_TOP
# 39_0 COME_FROM 3
# 40 ...
if self.opname_for_offset(jump_if_offset).startswith(
'JUMP_IF'):
jump_if_target = code[jump_if_offset + 1]
if self.opname_for_offset(jump_if_target +
jump_if_offset +
3) == 'POP_TOP':
jump_inst = jump_if_target + jump_if_offset
jump_offset = code[jump_inst + 1]
jump_op = self.opname_for_offset(jump_inst)
if (jump_op == 'JUMP_FORWARD'
and jump_offset == 1):
self.structs.append({
'type': 'if-then',
'start': start - 3,
'end': pre_rtarget
})
self.thens[start] = end
elif jump_op == 'JUMP_ABSOLUTE':
if_then_maybe = {
'type': 'if-then',
'start': start - 3,
'end': pre_rtarget
}
elif self.version == 2.7:
self.structs.append({
'type': 'if-then',
'start': start - 3,
'end': pre_rtarget
})
# FIXME: this is yet another case were we need dominators.
if pre_rtarget not in self.linestartoffsets or self.version < 2.7:
self.not_continue.add(pre_rtarget)
if rtarget < end:
# We have an "else" block of some kind.
# Is it associated with "if_then_maybe" seen above?
# These will be linked in this funny way:
# 198 JUMP_IF_FALSE 18 'to 219'
# 201 POP_TOP
# ...
# 216 JUMP_ABSOLUTE 256 'to 256'
# 219 POP_TOP
# ...
# 252 JUMP_FORWARD 1 'to 256'
# 255 POP_TOP
# 256
if if_then_maybe and jump_op == 'JUMP_ABSOLUTE':
jump_target = self.get_target(jump_inst,
code[jump_inst])
if self.opname_for_offset(end) == 'JUMP_FORWARD':
end_target = self.get_target(end, code[end])
if jump_target == end_target:
self.structs.append(if_then_maybe)
self.thens[start] = end
self.structs.append({
'type': 'else',
'start': rtarget,
'end': end
})
elif code_pre_rtarget == self.opc.RETURN_VALUE:
if self.version == 2.7 or pre_rtarget not in self.ignore_if:
self.structs.append({
'type': 'if-then',
'start': start,
'end': rtarget
})
self.thens[start] = rtarget
if self.version == 2.7 or code[pre_rtarget +
1] != self.opc.JUMP_FORWARD:
self.fixed_jumps[offset] = rtarget
self.return_end_ifs.add(pre_rtarget)
elif op in self.pop_jump_if_or_pop:
target = self.get_target(offset, op)
self.fixed_jumps[offset] = self.restrict_to_parent(target, parent)
def build_statement_indices(self):
code = self.code
start = 0
end = len(code)
stmt_opcode_seqs = frozenset([(self.opc.PJIF, self.opc.JUMP_FORWARD),
(self.opc.PJIF, self.opc.JUMP_ABSOLUTE),
(self.opc.PJIT, self.opc.JUMP_FORWARD),
(self.opc.PJIT, self.opc.JUMP_ABSOLUTE)])
prelim = self.all_instr(start, end, self.stmt_opcodes)
stmts = self.stmts = set(prelim)
pass_stmts = set()
for seq in stmt_opcode_seqs:
for i in self.op_range(start, end - (len(seq) + 1)):
match = True
for elem in seq:
if elem != code[i]:
match = False
break
i += op_size(code[i], self.opc)
if match:
i = self.prev[i]
stmts.add(i)
pass_stmts.add(i)
if pass_stmts:
stmt_list = list(stmts)
stmt_list.sort()
else:
stmt_list = prelim
last_stmt = -1
self.next_stmt = []
slist = self.next_stmt = []
i = 0
for s in stmt_list:
if code[s] == self.opc.JUMP_ABSOLUTE and s not in pass_stmts:
target = self.get_target(s)
if target > s or self.lines[last_stmt].l_no == self.lines[
s].l_no:
stmts.remove(s)
continue
j = self.prev[s]
while code[j] == self.opc.JUMP_ABSOLUTE:
j = self.prev[j]
if (self.version >= 2.3 and self.opname_for_offset(j)
== 'LIST_APPEND'): # list comprehension
stmts.remove(s)
continue
elif code[s] == self.opc.POP_TOP:
# The POP_TOP in:
# ROT_TWO, POP_TOP,
# RETURN_xxx, POP_TOP (in 2.6-), or
# JUMP_IF_{FALSE,TRUE}, POP_TOP (in 2.6-)
# is part of the previous instruction and not the
# beginning of a new statement
prev = code[self.prev[s]]
if (prev == self.opc.ROT_TWO or self.version < 2.7 and prev
in (self.opc.JUMP_IF_FALSE, self.opc.JUMP_IF_TRUE,
self.opc.RETURN_VALUE)):
stmts.remove(s)
continue
elif code[s] in self.designator_ops:
j = self.prev[s]
while code[j] in self.designator_ops:
j = self.prev[j]
if self.version > 2.1 and code[j] == self.opc.FOR_ITER:
stmts.remove(s)
continue
last_stmt = s
slist += [s] * (s - i)
i = s
slist += [end] * (end - len(slist))
def build_statement_indices(self):
code = self.code
start = 0
end = codelen = len(code)
# Compose preliminary list of indices with statements,
# using plain statement opcodes
prelim = self.all_instr(start, end, self.statement_opcodes)
# Initialize final container with statements with
# preliminary data
stmts = self.stmts = set(prelim)
# Same for opcode sequences
pass_stmts = set()
for sequence in self.statement_opcode_sequences:
for i in self.op_range(start, end-(len(sequence)+1)):
match = True
for elem in sequence:
if elem != code[i]:
match = False
break
i += op_size(code[i], self.opc)
if match is True:
i = self.prev_op[i]
stmts.add(i)
pass_stmts.add(i)
# Initialize statement list with the full data we've gathered so far
if pass_stmts:
stmt_offset_list = list(stmts)
stmt_offset_list.sort()
else:
stmt_offset_list = prelim
# 'List-map' which contains offset of start of
# next statement, when op offset is passed as index
self.next_stmt = slist = []
last_stmt_offset = -1
i = 0
# Go through all statement offsets
for stmt_offset in stmt_offset_list:
# Process absolute jumps, but do not remove 'pass' statements
# from the set
if (code[stmt_offset] == self.opc.JUMP_ABSOLUTE
and stmt_offset not in pass_stmts):
# If absolute jump occurs in forward direction or it takes off from the
# same line as previous statement, this is not a statement
target = self.get_target(stmt_offset)
if target > stmt_offset or self.lines[last_stmt_offset].l_no == self.lines[stmt_offset].l_no:
stmts.remove(stmt_offset)
continue
# Rewing ops till we encounter non-JUMP_ABSOLUTE one
j = self.prev_op[stmt_offset]
while code[j] == self.opc.JUMP_ABSOLUTE:
j = self.prev_op[j]
# If we got here, then it's list comprehension which
# is not a statement too
if code[j] == self.opc.LIST_APPEND:
stmts.remove(stmt_offset)
continue
# Exclude ROT_TWO + POP_TOP
elif (code[stmt_offset] == self.opc.POP_TOP
and code[self.prev_op[stmt_offset]] == self.opc.ROT_TWO):
stmts.remove(stmt_offset)
continue
# Exclude FOR_ITER + designators
elif code[stmt_offset] in self.designator_ops:
j = self.prev_op[stmt_offset]
while code[j] in self.designator_ops:
j = self.prev_op[j]
if code[j] == self.opc.FOR_ITER:
stmts.remove(stmt_offset)
continue
# Add to list another list with offset of current statement,
# equal to length of previous statement
slist += [stmt_offset] * (stmt_offset-i)
last_stmt_offset = stmt_offset
i = stmt_offset
# Finish filling the list for last statement
slist += [codelen] * (codelen-len(slist))