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Start to remove crud in control-flow detection for 3.7+

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rocky
2019-12-09 18:28:57 -05:00
parent 6546bbdaf9
commit edbbefb57d
2 changed files with 7 additions and 163 deletions
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163
uncompyle6/scanners/scanner37base.py
View File

@@ -775,184 +775,27 @@ class Scanner37Base(Scanner):
}
)
elif op in self.pop_jump_tf:
start = offset + inst.inst_size
target = inst.argval
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.
# FIXME: hack upon hack, test_pysource.py fails with this
# Until the grammar is corrected we do this fiction...
pretarget = self.get_inst(prev_op[target])
if (
pretarget.opcode in self.pop_jump_if_pop
and (target > offset)
and pretarget.offset != offset
):
# FIXME: hack upon hack...
# In some cases the pretarget can be a jump to the next instruction
# and these aren't and/or's either. We limit to 3.5+ since we experienced there
# but it might be earlier versions, or might be a general principle.
if pretarget.argval != target:
# FIXME: this is not accurate The commented out below
# is what it should be. However grammar rules right now
# assume the incorrect offsets.
# self.fixed_jumps[offset] = target
self.fixed_jumps[offset] = pretarget.offset
self.structs.append(
{"type": "and/or", "start": start, "end": pretarget.offset}
)
return
# The opcode *two* instructions before the target jump offset is important
# in making a determination of what we have. Save that.
pre_rtarget = prev_op[rtarget]
if op == self.opc.POP_JUMP_IF_FALSE:
self.fixed_jumps[offset] = target
# op == POP_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]] == self.opc.POP_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
rtarget_is_ja = code[pre_rtarget] == self.opc.JUMP_ABSOLUTE
if (
rtarget_is_ja
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:
# 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
#
# For 3.5, for JUMP_FORWARD above we could have also
# JUMP_BACK or CONTINUE
#
# There are other situations we may need to consider, like
# if the condition jump is to a forward location.
# Also the existence of a jump to the instruction after "END_FINALLY"
# will distinguish "try/else" from "try".
rtarget_break = (self.opc.RETURN_VALUE, self.opc.BREAK_LOOP)
if self.is_jump_forward(pre_rtarget) or (rtarget_is_ja):
if_end = self.get_target(pre_rtarget)
# If the jump target is back, we are looping
if (
if_end < pre_rtarget
and self.version < 3.8
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}
)
# FIXME: add this
# self.fixed_jumps[offset] = 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, 0):
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 rtarget_break:
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
pass
# 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 += instruction_size(self.code[next_op], self.opc)
if code[next_op] == self.opc.JUMP_ABSOLUTE:
next_op += instruction_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 self.version < 3.8 and come_from_op == self.opc.SETUP_EXCEPT:
return
pass
self.fixed_jumps[offset] = rtarget
if code[pre_rtarget] == self.opc.RETURN_VALUE:
# 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)
else:
if target > offset:
self.fixed_jumps[offset] = target
pass
self.fixed_jumps[offset] = target
elif self.version < 3.8 and op == self.opc.SETUP_EXCEPT:
target = self.get_target(offset)

7
uncompyle6/semantics/customize38.py
View File

@@ -89,9 +89,10 @@ def customize_for_version38(self, version):
(1, "_ifstmts_jumpl") ),
'whilestmt38': ( '%|while %c:\n%+%c%-\n\n',
(1, 'testexpr'), (2, 'l_stmts') ),
(1, 'testexpr'),
2 ), # "l_stmts" or "pass"
'whileTruestmt38': ( '%|while True:\n%+%c%-\n\n',
(1, 'l_stmts') ),
1 ), # "l_stmts" or "pass"
'try_elsestmtl38': (
'%|try:\n%+%c%-%c%|else:\n%+%c%-',
(1, 'suite_stmts_opt'),
@@ -106,7 +107,7 @@ def customize_for_version38(self, version):
'tryfinally38': (
'%|try:\n%+%c%-%|finally:\n%+%c%-\n\n',
(3, 'returns'), 6 ),
"named_expr": ( # AKA "walrus operatotr"
"named_expr": ( # AKA "walrus operator"
"%c := %c", (2, "store"), (0, "expr")
)
})