def test_simplify_dead_assign_1():
# if a register is used ever, it should not be simplified away
arch = archinfo.arch_from_id('AMD64')
block = ailment.Block(0x1337, 10)
n = count(start=1)
important = 0x999
block.statements.extend([
ailment.Assignment(
next(n),
ailment.Register(next(n), None, arch.registers['rdi'][0], 64),
ailment.Const(next(n), None, 0x13371337, 64),
ins_addr=0x1337,
), # rdi = 0x13371337
ailment.Stmt.Call(
important,
ailment.Const(next(n), None, 0x400080, 64),
ins_addr=0x1338,
), # Call(0x400080), which uses rdi but also overwrites rdi (since it is a caller-saved argument)
])
b = block_simplify(block)
nose.tools.assert_equal(len(b.statements), 2)
nose.tools.assert_equal(b.statements[0].idx, 1)
nose.tools.assert_equal(b.statements[1].idx, important)
def test_simplify_dead_assign_0():
block = ailment.Block(0x1337, 10)
n = count()
important = 0x999
block.statements.extend(
[
ailment.Assignment(
next(n),
ailment.Register(next(n), None, 1, 64),
ailment.Const(next(n), None, 100, 64),
ins_addr=0x1337,
),
ailment.Assignment(
important,
ailment.Register(next(n), None, 1, 64),
ailment.Const(next(n), None, 101, 64),
ins_addr=0x1338,
),
ailment.Stmt.Jump(
next(n),
ailment.Expr.Const(None, None, 0x3333, 64),
ins_addr=0x1338
),
]
)
b = block_simplify(block)
nose.tools.assert_equal(len(b.statements), 2)
nose.tools.assert_equal(b.statements[0].idx, important)