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Conditional jumps to extended-arg JUMP_BACK...

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this is a major reworking. But it leads the way forward to a
simpler grammar.
This commit is contained in:
rocky
2020-01-22 04:49:44 -05:00
parent c6069eb7f8
commit bc50825460
10 changed files with 211 additions and 45 deletions
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39
uncompyle6/scanners/scanner37base.py
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@@ -30,7 +30,7 @@ Finally we save token information.
"""
from xdis.code import iscode
from xdis.bytecode import instruction_size, _get_const_info
from xdis.bytecode import instruction_size, _get_const_info, Instruction
from uncompyle6.scanner import Token
import xdis
@@ -253,6 +253,39 @@ class Scanner37Base(Scanner):
pass
pass
# Operand values in Python wordcode are small. As a result,
# there are these EXTENDED_ARG instructions - way more than
# before 3.6. These parsing a lot of pain.
# To simplify things we want to untangle this. We also
# do this loop before we compute jump targets.
for i, inst in enumerate(self.insts):
# One artifact of the "too-small" operand problem, is that
# some backward jumps, are turned into forward jumps to another
# "extended arg" backward jump to the same location.
if inst.opname == "JUMP_FORWARD":
jump_inst = self.insts[self.offset2inst_index[inst.argval]]
if jump_inst.has_extended_arg:
# Create comination of the jump-to instruction and
# this one. Keep the position information of this instruction,
# but the operator and operand properties come from the other
# instruction
self.insts[i] = Instruction(
jump_inst.opname,
jump_inst.opcode,
jump_inst.optype,
jump_inst.inst_size,
jump_inst.arg,
jump_inst.argval,
jump_inst.argrepr,
jump_inst.has_arg,
inst.offset,
inst.starts_line,
inst.is_jump_target,
inst.has_extended_arg,
)
# Get jump targets
# Format: {target offset: [jump offsets]}
jump_targets = self.find_jump_targets(show_asm)
@@ -302,6 +335,7 @@ class Scanner37Base(Scanner):
offset="%s_%s" % (inst.offset, jump_idx),
has_arg=True,
opc=self.opc,
has_extended_arg=False,
),
)
jump_idx += 1
@@ -318,6 +352,7 @@ class Scanner37Base(Scanner):
offset="%s" % (inst.offset),
has_arg=True,
opc=self.opc,
has_extended_arg=inst.has_extended_arg,
),
)
@@ -382,6 +417,7 @@ class Scanner37Base(Scanner):
op=op,
has_arg=inst.has_arg,
opc=self.opc,
has_extended_arg=inst.has_extended_arg,
),
)
continue
@@ -475,6 +511,7 @@ class Scanner37Base(Scanner):
op=op,
has_arg=inst.has_arg,
opc=self.opc,
has_extended_arg=inst.has_extended_arg,
),
)
pass