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|
from miasm2.ir.translators.translator import Translator
from miasm2.expression.modint import size2mask
from miasm2.expression.expression import ExprInt, ExprCond, ExprCompose, \
TOK_EQUAL
def int_size_to_bn(value, size):
if size < 32:
int_str = "%.8x" % value
size_nibble = 8
else:
# size must be multiple of 4
size = ((size + 31) / 32) * 32
size_nibble = size / 4
fmt_str = "%%.%dx" % size_nibble
int_str = fmt_str % value
assert len(int_str) == size_nibble
return int_str, size_nibble
class TranslatorC(Translator):
"Translate a Miasm expression to an equivalent C code"
# Implemented language
__LANG__ = "C"
# Operations translation
dct_shift = {'a>>': "right_arith",
'>>': "right_logic",
'<<': "left_logic",
}
dct_rot = {'<<<': 'rot_left',
'>>>': 'rot_right',
}
NATIVE_INT_MAX_SIZE = 64
def __init__(self, loc_db=None, **kwargs):
"""Instance a C translator
@loc_db: LocationDB instance
"""
super(TranslatorC, self).__init__(**kwargs)
# symbol pool
self.loc_db = loc_db
def _size2mask(self, size):
"""Return a C string corresponding to the size2mask operation, with support for
@size <= 64"""
assert size <= 64
mask = size2mask(size)
return "0x%x" % mask
def from_ExprId(self, expr):
return str(expr)
def from_ExprInt(self, expr):
if expr.size <= self.NATIVE_INT_MAX_SIZE:
assert expr.size <= 64
out = "0x%x" % int(expr)
if expr.size == 64:
out += "ULL"
return out
value, int_size = int_size_to_bn(int(expr), expr.size)
return 'bignum_from_string("%s", %d)' % (value, int_size)
def from_ExprLoc(self, expr):
loc_key = expr.loc_key
if self.loc_db is None:
return str(loc_key)
offset = self.loc_db.get_location_offset(loc_key)
if offset is None:
return str(loc_key)
if expr.size <= self.NATIVE_INT_MAX_SIZE:
return "0x%x" % offset
value, int_size = int_size_to_bn(offset, 64)
return 'bignum_from_string("%s", %d)' % (value, int_size)
def from_ExprAssign(self, expr):
new_dst = self.from_expr(expr.dst)
new_src = self.from_expr(expr.src)
return "%s = %s" % (new_dst, new_src)
def from_ExprCond(self, expr):
cond = self.from_expr(expr.cond)
src1 = self.from_expr(expr.src1)
src2 = self.from_expr(expr.src2)
if not expr.cond.size <= self.NATIVE_INT_MAX_SIZE:
cond = "(!bignum_is_zero(%s))" % cond
out = "(%s?%s:%s)" % (cond, src1, src2)
return out
def from_ExprMem(self, expr):
ptr = expr.ptr
if ptr.size <= self.NATIVE_INT_MAX_SIZE:
new_ptr = self.from_expr(ptr)
if expr.size <= self.NATIVE_INT_MAX_SIZE:
# Native ptr, Native Mem
return "MEM_LOOKUP_%.2d(jitcpu, %s)" % (expr.size, new_ptr)
else:
# Native ptr, BN mem
return "MEM_LOOKUP_INT_BN(jitcpu, %d, %s)" % (expr.size, new_ptr)
# BN ptr
new_ptr = self.from_expr(ptr)
if expr.size <= self.NATIVE_INT_MAX_SIZE:
# BN ptr, Native Mem
return "MEM_LOOKUP_BN_INT(jitcpu, %d, %s)" % (expr.size, new_ptr)
else:
# BN ptr, BN mem
return "MEM_LOOKUP_BN_BN(jitcpu, %d, %s)" % (expr.size, new_ptr)
def from_ExprOp(self, expr):
if len(expr.args) == 1:
if expr.op == 'parity':
arg = expr.args[0]
out = self.from_expr(arg)
if arg.size <= self.NATIVE_INT_MAX_SIZE:
out = "(%s&%s)" % (out, self._size2mask(arg.size))
else:
out = 'bignum_mask(%s, 8)' % (out, 8)
out = 'bignum_to_uint64(%s)' % out
out = 'parity(%s)' % out
return out
elif expr.op.startswith("zeroExt_"):
arg = expr.args[0]
if expr.size == arg.size:
return arg
return self.from_expr(ExprCompose(arg, ExprInt(0, expr.size - arg.size)))
elif expr.op.startswith("signExt_"):
arg = expr.args[0]
if expr.size == arg.size:
return arg
add_size = expr.size - arg.size
new_expr = ExprCompose(
arg,
ExprCond(
arg.msb(),
ExprInt(size2mask(add_size), add_size),
ExprInt(0, add_size)
)
)
return self.from_expr(new_expr)
elif expr.op in ['cntleadzeros', 'cnttrailzeros']:
arg = expr.args[0]
out = self.from_expr(arg)
if arg.size <= self.NATIVE_INT_MAX_SIZE:
out = "%s(0x%x, %s)" % (expr.op, expr.args[0].size, out)
else:
out = "bignum_%s(%s, %d)" % (expr.op, out, arg.size)
return out
elif expr.op == '!':
arg = expr.args[0]
out = self.from_expr(arg)
if expr.size <= self.NATIVE_INT_MAX_SIZE:
out = "(~ %s)&%s" % (out, self._size2mask(arg.size))
else:
out = "bignum_not(%s)" % out
out = "bignum_mask(%s, expr.size)" % out
return out
elif expr.op in [
"ftan", "frndint", "f2xm1", "fsin", "fsqrt", "fabs", "fcos",
"fchs",
]:
return "fpu_%s%d(%s)" % (
expr.op,
expr.size,
self.from_expr(expr.args[0]),
)
elif (expr.op.startswith("access_") or
expr.op.startswith("load_") or
expr.op.startswith("fxam_c")):
arg = expr.args[0]
out = self.from_expr(arg)
out = "%s(%s)" % (expr.op, out)
return out
elif expr.op == "-":
arg = expr.args[0]
out = self.from_expr(arg)
if arg.size <= self.NATIVE_INT_MAX_SIZE:
out = "(%s(%s))" % (expr.op, out)
out = "(%s&%s)" % (out, self._size2mask(arg.size))
else:
out = "bignum_sub(bignum_from_uint64(0), %s)" % out
out = "bignum_mask(%s, %d)"% (out, expr.size)
return out
elif expr.op.startswith("fpround_"):
return "%s_fp%d(%s)" % (
expr.op,
expr.size,
self.from_expr(expr.args[0]),
)
elif expr.op == "sint_to_fp":
size = expr.size
arg = expr.args[0]
if size not in [32, 64]:
raise RuntimeError(
"Unsupported size for sint_to_fp: %r" % size
)
return "%s_%d(%s)" % (expr.op, size, self.from_expr(arg))
elif expr.op.startswith("fp_to_sint"):
dest_size = expr.size
arg_size = expr.args[0].size
if (arg_size, dest_size) in [
(32, 32), (64, 64), (64, 32),
]:
func = "fp%d_to_sint%d" % (arg_size, dest_size)
else:
raise RuntimeError(
"Unsupported size for fp_to_sint: %r to %r" % (
arg_size,
dest_size
))
return "%s(%s)" % (func, self.from_expr(expr.args[0]))
elif expr.op.startswith("fpconvert_fp"):
dest_size = expr.size
arg_size = expr.args[0].size
if (arg_size, dest_size) in [
(32, 64), (64, 32)
]:
func = "fp%d_to_fp%d" % (arg_size, dest_size)
else:
raise RuntimeError(
"Unsupported size for fpconvert: %r to %r" % (arg_size,
dest_size)
)
return "%s(%s)" % (func, self.from_expr(expr.args[0]))
else:
raise NotImplementedError('Unknown op: %r' % expr.op)
elif len(expr.args) == 2:
if expr.op == TOK_EQUAL:
return '(((%s&%s) == (%s&%s))?1:0)' % (
self.from_expr(expr.args[0]),
self._size2mask(expr.args[0].size),
self.from_expr(expr.args[1]),
self._size2mask(expr.args[1].size),
)
elif expr.op in self.dct_shift:
arg0 = self.from_expr(expr.args[0])
arg1 = self.from_expr(expr.args[1])
if expr.size <= self.NATIVE_INT_MAX_SIZE:
out = 'SHIFT_%s(%d, %s, %s)' % (
self.dct_shift[expr.op].upper(),
expr.args[0].size,
arg0,
arg1
)
else:
op = {
"<<": "lshift",
">>": "rshift",
"a>>": "a_rshift"
}
out = "bignum_%s(%s, bignum_to_uint64(%s))" % (
op[expr.op], arg0, arg1
)
out = "bignum_mask(%s, %d)"% (out, expr.size)
return out
elif expr.is_associative():
args = [self.from_expr(arg)
for arg in expr.args]
if expr.size <= self.NATIVE_INT_MAX_SIZE:
out = (" %s " % expr.op).join(args)
out = "((%s)&%s)" % (out, self._size2mask(expr.size))
else:
op_to_bn_func = {
"+": "add",
"*": "mul",
"|": "or",
"^": "xor",
"&": "and",
}
args = list(expr.args)
out = self.from_expr(args.pop())
while args:
out = 'bignum_mask(bignum_%s(%s, %s), %d)' % (
op_to_bn_func[expr.op],
out,
self.from_expr(args.pop()),
expr.size
)
return out
elif expr.op in ['-']:
return '(((%s&%s) %s (%s&%s))&%s)' % (
self.from_expr(expr.args[0]),
self._size2mask(expr.args[0].size),
str(expr.op),
self.from_expr(expr.args[1]),
self._size2mask(expr.args[1].size),
self._size2mask(expr.args[0].size)
)
elif expr.op in self.dct_rot:
arg0 = self.from_expr(expr.args[0])
arg1 = self.from_expr(expr.args[1])
if expr.size <= self.NATIVE_INT_MAX_SIZE:
out = '(%s(%s, %s, %s) &%s)' % (
self.dct_rot[expr.op],
expr.args[0].size,
arg0,
arg1,
self._size2mask(expr.args[0].size),
)
else:
op = {
">>>": "ror",
"<<<": "rol"
}
out = "bignum_%s(%s, %d, bignum_to_uint64(%s))" % (
op[expr.op], arg0, expr.size, arg1
)
out = "bignum_mask(%s, %d)"% (out, expr.size)
return out
elif expr.op == 'x86_cpuid':
return "%s(%s, %s)" % (expr.op,
self.from_expr(expr.args[0]),
self.from_expr(expr.args[1]))
elif expr.op.startswith("fcom"):
arg0 = self.from_expr(expr.args[0])
arg1 = self.from_expr(expr.args[1])
if not expr.args[0].size <= self.NATIVE_INT_MAX_SIZE:
raise ValueError("Bad semantic: fpu do operations do not support such size")
out = "fpu_%s(%s, %s)" % (expr.op, arg0, arg1)
return out
elif expr.op in ["fadd", "fsub", "fdiv", 'fmul', "fscale",
"fprem", "fyl2x", "fpatan"]:
arg0 = self.from_expr(expr.args[0])
arg1 = self.from_expr(expr.args[1])
if not expr.args[0].size <= self.NATIVE_INT_MAX_SIZE:
raise ValueError("Bad semantic: fpu do operations do not support such size")
out = "fpu_%s%d(%s, %s)" % (expr.op, expr.size, arg0, arg1)
return out
elif expr.op == "segm":
return "segm2addr(jitcpu, %s, %s)" % (
self.from_expr(expr.args[0]),
self.from_expr(expr.args[1])
)
elif expr.op in ['udiv', 'umod']:
arg0 = self.from_expr(expr.args[0])
arg1 = self.from_expr(expr.args[1])
if expr.size <= self.NATIVE_INT_MAX_SIZE:
out = '%s%d(%s, %s)' % (
expr.op,
expr.args[0].size,
arg0,
arg1
)
else:
out = "bignum_%s(%s, %s)" % (
expr.op,
arg0,
arg1
)
out = "bignum_mask(%s, %d)"% (out, expr.size)
return out
elif expr.op in ['idiv', 'imod']:
arg0 = self.from_expr(expr.args[0])
arg1 = self.from_expr(expr.args[1])
if expr.size <= self.NATIVE_INT_MAX_SIZE:
out = '%s%d(%s, %s)' % (
expr.op,
expr.args[0].size,
arg0,
arg1
)
else:
out = "bignum_%s(%s, %s, %d)" % (
expr.op,
arg0,
arg1,
expr.size
)
out = "bignum_mask(%s, %d)"% (out, expr.size)
return out
elif expr.op in ["bcdadd", "bcdadd_cf"]:
return "%s_%d(%s, %s)" % (
expr.op, expr.args[0].size,
self.from_expr(expr.args[0]),
self.from_expr(expr.args[1])
)
else:
raise NotImplementedError('Unknown op: %r' % expr.op)
elif len(expr.args) >= 3 and expr.is_associative(): # ?????
oper = ['(%s&%s)' % (
self.from_expr(arg),
self._size2mask(arg.size),
)
for arg in expr.args]
oper = str(expr.op).join(oper)
return "((%s)&%s)" % (
oper,
self._size2mask(expr.args[0].size)
)
else:
raise NotImplementedError('Unknown op: %s' % expr.op)
def from_ExprSlice(self, expr):
out = self.from_expr(expr.arg)
if expr.arg.size <= self.NATIVE_INT_MAX_SIZE:
# XXX check mask for 64 bit & 32 bit compat
out = "((%s>>%d) &%s)" % (
out, expr.start,
self._size2mask(expr.stop - expr.start)
)
else:
out = "bignum_rshift(%s, %d)" % (out, expr.start)
out = "bignum_mask(%s, %d)" % (out, expr.stop - expr.start)
if expr.size <= self.NATIVE_INT_MAX_SIZE:
# Convert bignum to int
out = "bignum_to_uint64(%s)" % out
return out
def from_ExprCompose(self, expr):
if expr.size <= self.NATIVE_INT_MAX_SIZE:
out = []
# XXX check mask for 64 bit & 32 bit compat
if expr.size in [8, 16, 32, 64, 128]:
size = expr.size
else:
# Uncommon expression size, use at least uint8
size = max(expr.size, 8)
next_power = 1
while next_power <= size:
next_power <<= 1
size = next_power
dst_cast = "uint%d_t" % size
for index, arg in expr.iter_args():
out.append("(((%s)(%s & %s)) << %d)" % (
dst_cast,
self.from_expr(arg),
self._size2mask(arg.size),
index)
)
out = ' | '.join(out)
return '(' + out + ')'
else:
# Convert all parts to bignum
args = []
for index, arg in expr.iter_args():
arg_str = self.from_expr(arg)
if arg.size <= self.NATIVE_INT_MAX_SIZE:
arg_str = '((%s) & %s)' % (arg_str, self._size2mask(arg.size))
arg_str = 'bignum_from_uint64(%s)' % arg_str
else:
arg_str = 'bignum_mask(%s, %d)' % (arg_str, arg.size)
arg_str = 'bignum_lshift(%s, %d)' % (arg_str, index)
args.append(arg_str)
out = args.pop()
while args:
arg = args.pop()
out = "bignum_or(%s, %s)" % (out, arg)
return out
# Register the class
Translator.register(TranslatorC)
|