Better Python 3 ENDIF detection

If we have

COMPARE_OP exception-match
POP_JUMP_IF...
....
RETURN_VALUE

Then RETURN_VALUE can't be RETURN_END_IF
This commit is contained in:
rocky
2017-11-08 23:05:01 -05:00
parent 0bb793239b
commit e9b60ddbf0
2 changed files with 29 additions and 26 deletions

View File

@@ -359,7 +359,7 @@ class Scanner3(Scanner):
# rule for that.
pattr = argval
# FIXME: 0 isn't always correct
target = self.get_target(inst.offset, 0)
target = self.get_target(inst.offset)
if target <= inst.offset:
next_opname = self.opname[self.code[inst.offset+3]]
if (inst.offset in self.stmts and
@@ -499,7 +499,7 @@ class Scanner3(Scanner):
# Determine structures and fix jumps in Python versions
# since 2.3
self.detect_control_flow(offset, targets, 0)
self.detect_control_flow(offset, targets, i)
if inst.has_arg:
label = self.fixed_jumps.get(offset)
@@ -579,7 +579,7 @@ class Scanner3(Scanner):
# If absolute jump occurs in forward direction or it takes off from the
# same line as previous statement, this is not a statement
# FIXME: 0 isn't always correct
target = self.get_target(stmt_offset, 0)
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
@@ -613,7 +613,7 @@ class Scanner3(Scanner):
# Finish filling the list for last statement
slist += [codelen] * (codelen-len(slist))
def get_target(self, offset, extended_arg):
def get_target(self, offset, extended_arg=0):
"""
Get target offset for op located at given <offset>.
"""
@@ -634,7 +634,7 @@ class Scanner3(Scanner):
return target
def detect_control_flow(self, offset, targets, extended_arg):
def detect_control_flow(self, offset, targets, inst_index):
"""
Detect structures and their boundaries to fix optimized jumps
in python2.3+
@@ -667,7 +667,7 @@ class Scanner3(Scanner):
# It could be a return instruction.
start += instruction_size(op, self.opc)
target = self.get_target(offset, extended_arg)
target = self.get_target(offset, 0)
end = self.restrict_to_parent(target, parent)
self.setup_loops[target] = offset
@@ -712,7 +712,7 @@ class Scanner3(Scanner):
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, extended_arg) == self.get_target(end, extended_arg):
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:
@@ -721,7 +721,7 @@ class Scanner3(Scanner):
# I think 0 right because jump_back has been adjusted for any EXTENDED_ARG
# it encounters
target = self.get_target(jump_back, 0)
target = self.get_target(jump_back)
if code[target] in (self.opc.FOR_ITER, self.opc.GET_ITER):
loop_type = 'for'
@@ -733,7 +733,7 @@ class Scanner3(Scanner):
loop_type = 'while 1'
elif self.code[test] in self.opc.JUMP_OPs:
self.ignore_if.add(test)
test_target = self.get_target(test, extended_arg)
test_target = self.get_target(test)
if test_target > (jump_back+3):
jump_back = test_target
self.not_continue.add(jump_back)
@@ -748,7 +748,7 @@ class Scanner3(Scanner):
'end': end})
elif op in self.pop_jump_tf:
start = offset + instruction_size(op, self.opc)
target = self.get_target(offset, extended_arg)
target = self.get_target(offset)
rtarget = self.restrict_to_parent(target, parent)
prev_op = self.prev_op
@@ -791,12 +791,12 @@ class Scanner3(Scanner):
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, extended_arg), parent) == rtarget):
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], extended_arg) 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], extended_arg) > prev_op[pre_rtarget]) and
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], self.pop_jump_tf, target)))):
pass
elif (code[prev_op[pre_rtarget]] == self.opc.RETURN_VALUE
@@ -815,7 +815,7 @@ class Scanner3(Scanner):
self.opc.POP_JUMP_IF_FALSE)
last_jump_good = True
for j in jump_ifs:
if target == self.get_target(j, extended_arg):
if target == self.get_target(j):
if self.lines[j].next == j + 3 and last_jump_good:
fix = j
break
@@ -831,7 +831,7 @@ class Scanner3(Scanner):
next = self.next_stmt[offset]
if prev_op[next] == offset:
pass
elif self.is_jump_forward(next) and target == self.get_target(next, extended_arg):
elif self.is_jump_forward(next) and target == self.get_target(next):
if code[prev_op[next]] == self.opc.POP_JUMP_IF_FALSE:
if (code[next] == self.opc.JUMP_FORWARD
or target != rtarget
@@ -840,7 +840,7 @@ class Scanner3(Scanner):
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, extended_arg) == self.get_target(next, extended_arg)):
self.get_target(target) == self.get_target(next)):
self.fixed_jumps[offset] = prev_op[next]
return
@@ -937,7 +937,10 @@ class Scanner3(Scanner):
pass
pass
if code[pre_rtarget] == self.opc.RETURN_VALUE:
self.return_end_ifs.add(pre_rtarget)
# If we are at some sort of POP_JUMP_IF and the instruction before was
# COMPARE_OP exception-match, then pre_rtarget is not an end_if
if not (inst_index > 0 and self.insts[inst_index-1].argval == 'exception-match'):
self.return_end_ifs.add(pre_rtarget)
else:
self.fixed_jumps[offset] = rtarget
self.not_continue.add(pre_rtarget)
@@ -955,12 +958,12 @@ class Scanner3(Scanner):
self.fixed_jumps[offset] = rtarget
elif op == self.opc.SETUP_EXCEPT:
target = self.get_target(offset, extended_arg)
target = self.get_target(offset)
end = self.restrict_to_parent(target, parent)
self.fixed_jumps[offset] = end
elif op == self.opc.POP_EXCEPT:
next_offset = xdis.next_offset(op, self.opc, offset)
target = self.get_target(next_offset, extended_arg)
target = self.get_target(next_offset)
if target > next_offset:
next_op = code[next_offset]
if (self.opc.JUMP_ABSOLUTE == next_op and
@@ -969,11 +972,11 @@ class Scanner3(Scanner):
self.except_targets[target] = next_offset
elif op == self.opc.SETUP_FINALLY:
target = self.get_target(offset, extended_arg)
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, extended_arg)
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:
@@ -997,7 +1000,7 @@ class Scanner3(Scanner):
# 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, extended_arg)
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):

View File

@@ -23,7 +23,7 @@ class Scanner30(Scanner3):
return
pass
def detect_control_flow(self, offset, targets, extended_arg):
def detect_control_flow(self, offset, targets, inst_index):
"""
Detect structures and their boundaries to fix optimized jumps
Python 3.0 is more like Python 2.6 than it is Python 3.x.
@@ -55,7 +55,7 @@ class Scanner30(Scanner3):
# It could be a return instruction.
start += instruction_size(op, self.opc)
target = self.get_target(offset, extended_arg)
target = self.get_target(offset)
end = self.restrict_to_parent(target, parent)
self.setup_loop_targets[offset] = target
self.setup_loops[target] = offset
@@ -136,7 +136,7 @@ class Scanner30(Scanner3):
'end': end})
elif op in self.pop_jump_tf:
start = offset + instruction_size(op, self.opc)
target = self.get_target(offset, extended_arg)
target = self.get_target(offset)
rtarget = self.restrict_to_parent(target, parent)
prev_op = self.prev_op
@@ -329,7 +329,7 @@ class Scanner30(Scanner3):
end = self.restrict_to_parent(target, parent)
self.fixed_jumps[offset] = end
elif op == self.opc.SETUP_FINALLY:
target = self.get_target(offset, extended_arg)
target = self.get_target(offset)
end = self.restrict_to_parent(target, parent)
self.fixed_jumps[offset] = end
elif op in self.jump_if_pop: