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"""
Example of "constant expression" propagation.
A "constant expression" is an expression based on constants or init regs.
"""
from argparse import ArgumentParser
from miasm2.arch.x86.disasm import dis_x86_32 as dis_engine
from miasm2.analysis.machine import Machine
from miasm2.analysis.binary import Container
from miasm2.analysis.cst_propag import propagate_cst_expr
from miasm2.analysis.data_flow import dead_simp
from miasm2.expression.simplifications import expr_simp
parser = ArgumentParser("Constant expression propagation")
parser.add_argument('filename', help="File to analyze")
parser.add_argument('address', help="Starting address for disassembly engine")
parser.add_argument('-s', "--simplify", action="store_true",
help="Apply simplifications rules (liveness, graph simplification, ...)")
args = parser.parse_args()
machine = Machine("x86_32")
cont = Container.from_stream(open(args.filename))
ira, dis_engine = machine.ira, machine.dis_engine
mdis = dis_engine(cont.bin_stream)
ir_arch = ira(mdis.loc_db)
addr = int(args.address, 0)
asmcfg = mdis.dis_multiblock(addr)
ircfg = ir_arch.new_ircfg_from_asmcfg(asmcfg)
init_infos = ir_arch.arch.regs.regs_init
cst_propag_link = propagate_cst_expr(ir_arch, ircfg, addr, init_infos)
if args.simplify:
ircfg.simplify(expr_simp)
modified = True
while modified:
modified = False
modified |= dead_simp(ir_arch, ircfg)
modified |= ircfg.remove_empty_assignblks()
modified |= ircfg.remove_jmp_blocks()
modified |= ircfg.merge_blocks()
open("%s.propag.dot" % args.filename, 'w').write(ircfg.dot())
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