Coverage for /pythoncovmergedfiles/medio/medio/usr/local/lib/python3.8/site-packages/pyvex/lifting/lifter.py: 96%

1from pyvex.block import IRSB 

2 

3# pylint:disable=attribute-defined-outside-init 

4 

5 

6class Lifter: 

7 __slots__ = ( 

8 "data", 

9 "bytes_offset", 

10 "opt_level", 

11 "traceflags", 

12 "allow_arch_optimizations", 

13 "strict_block_end", 

14 "collect_data_refs", 

15 "max_inst", 

16 "max_bytes", 

17 "skip_stmts", 

18 "irsb", 

19 "arch", 

20 "addr", 

21 "cross_insn_opt", 

22 "load_from_ro_regions", 

23 ) 

24 

25 """ 

26 A lifter is a class of methods for processing a block. 

27 

28 :ivar data: The bytes to lift as either a python string of bytes or a cffi buffer object. 

29 :ivar bytes_offset: The offset into `data` to start lifting at. 

30 :ivar max_bytes: The maximum number of bytes to lift. If set to None, no byte limit is used. 

31 :ivar max_inst: The maximum number of instructions to lift. If set to None, no instruction limit is used. 

32 :ivar opt_level: The level of optimization to apply to the IR, 0-2. Most likely will be ignored in any lifter 

33 other then LibVEX. 

34 :ivar traceflags: The libVEX traceflags, controlling VEX debug prints. Most likely will be ignored in any 

35 lifter other than LibVEX. 

36 :ivar allow_arch_optimizations: Should the LibVEX lifter be allowed to perform lift-time preprocessing 

37 optimizations (e.g., lookback ITSTATE optimization on THUMB) 

38 Most likely will be ignored in any lifter other than LibVEX. 

39 :ivar strict_block_end: Should the LibVEX arm-thumb split block at some instructions, for example CB{N}Z. 

40 :ivar skip_stmts: Should LibVEX ignore statements. 

41 """ 

42 REQUIRE_DATA_C = False 

43 REQUIRE_DATA_PY = False 

44 

45 def __init__(self, arch, addr): 

46 self.arch = arch 

47 self.addr = addr 

48 

49 def lift( 

50 self, 

51 data, 

52 bytes_offset=None, 

53 max_bytes=None, 

54 max_inst=None, 

55 opt_level=1, 

56 traceflags=None, 

57 allow_arch_optimizations=None, 

58 strict_block_end=None, 

59 skip_stmts=False, 

60 collect_data_refs=False, 

61 cross_insn_opt=True, 

62 load_from_ro_regions=False, 

63 ): 

64 """ 

65 Wrapper around the `_lift` method on Lifters. Should not be overridden in child classes. 

66 

67 :param data: The bytes to lift as either a python string of bytes or a cffi buffer object. 

68 :param bytes_offset: The offset into `data` to start lifting at. 

69 :param max_bytes: The maximum number of bytes to lift. If set to None, no byte limit is used. 

70 :param max_inst: The maximum number of instructions to lift. If set to None, no instruction limit is 

71 used. 

72 :param opt_level: The level of optimization to apply to the IR, 0-2. Most likely will be ignored in 

73 any lifter other then LibVEX. 

74 :param traceflags: The libVEX traceflags, controlling VEX debug prints. Most likely will be ignored in 

75 any lifter other than LibVEX. 

76 :param allow_arch_optimizations: Should the LibVEX lifter be allowed to perform lift-time preprocessing 

77 optimizations (e.g., lookback ITSTATE optimization on THUMB) Most likely will be 

78 ignored in any lifter other than LibVEX. 

79 :param strict_block_end: Should the LibVEX arm-thumb split block at some instructions, for example CB{N}Z. 

80 :param skip_stmts: Should the lifter skip transferring IRStmts from C to Python. 

81 :param collect_data_refs: Should the LibVEX lifter collect data references in C. 

82 :param cross_insn_opt: If cross-instruction-boundary optimizations are allowed or not. 

83 """ 

84 irsb = IRSB.empty_block(self.arch, self.addr) 

85 self.data = data 

86 self.bytes_offset = bytes_offset 

87 self.opt_level = opt_level 

88 self.traceflags = traceflags 

89 self.allow_arch_optimizations = allow_arch_optimizations 

90 self.strict_block_end = strict_block_end 

91 self.collect_data_refs = collect_data_refs 

92 self.max_inst = max_inst 

93 self.max_bytes = max_bytes 

94 self.skip_stmts = skip_stmts 

95 self.irsb = irsb 

96 self.cross_insn_opt = cross_insn_opt 

97 self.load_from_ro_regions = load_from_ro_regions 

98 self._lift() 

99 return self.irsb 

100 

101 def _lift(self): 

102 """ 

103 Lifts the data using the information passed into _lift. Should be overridden in child classes. 

104 

105 Should set the lifted IRSB to self.irsb. 

106 If a lifter raises a LiftingException on the data, this signals that the lifter cannot lift this data and arch 

107 and the lifter is skipped. 

108 If a lifter can lift any amount of data, it should lift it and return the lifted block with a jumpkind of 

109 Ijk_NoDecode, signalling to pyvex that other lifters should be used on the undecodable data. 

110 

111 """ 

112 raise NotImplementedError()