test/test_dwarf_expr.py

   1 #-------------------------------------------------------------------------------
   2 # elftools tests
   3 #
   4 # Eli Bendersky (eliben@gmail.com)
   5 # This code is in the public domain
   6 #-------------------------------------------------------------------------------
   7 import unittest
   8
   9 from elftools.dwarf.descriptions import ExprDumper, set_global_machine_arch
  10 from elftools.dwarf.dwarf_expr import DWARFExprParser, DWARFExprOp
  11 from elftools.dwarf.structs import DWARFStructs
  12
  13
  14 class TestExprDumper(unittest.TestCase):
  15     structs32 = DWARFStructs(
  16             little_endian=True,
  17             dwarf_format=32,
  18             address_size=4)
  19
  20     def setUp(self):
  21         self.visitor = ExprDumper(self.structs32)
  22         set_global_machine_arch('x64')
  23
  24     def test_basic_single(self):
  25         self.assertEqual(self.visitor.dump_expr([0x1b]),
  26             'DW_OP_div')
  27
  28         self.assertEqual(self.visitor.dump_expr([0x74, 0x82, 0x01]),
  29             'DW_OP_breg4 (rsi): 130')
  30
  31         self.assertEqual(self.visitor.dump_expr([0x91, 0x82, 0x01]),
  32             'DW_OP_fbreg: 130')
  33
  34         self.assertEqual(self.visitor.dump_expr([0x51]),
  35             'DW_OP_reg1 (rdx)')
  36
  37         self.assertEqual(self.visitor.dump_expr([0x90, 16]),
  38             'DW_OP_regx: 16 (rip)')
  39
  40         self.assertEqual(self.visitor.dump_expr([0x9d, 0x8f, 0x0A, 0x90, 0x01]),
  41             'DW_OP_bit_piece: 1295 144')
  42
  43         self.assertEqual(self.visitor.dump_expr([0x0e, 0xff, 0x00, 0xff, 0x00, 0xff, 0x00, 0xff, 0x00]),
  44             'DW_OP_const8u: 71777214294589695')
  45
  46     def test_basic_sequence(self):
  47         self.assertEqual(self.visitor.dump_expr([0x03, 0x01, 0x02, 0, 0, 0x06, 0x06]),
  48             'DW_OP_addr: 201; DW_OP_deref; DW_OP_deref')
  49
  50         self.assertEqual(self.visitor.dump_expr([0x15, 0xFF, 0x0b, 0xf1, 0xff]),
  51             'DW_OP_pick: 255; DW_OP_const2s: -15')
  52
  53         self.assertEqual(self.visitor.dump_expr([0x1d, 0x1e, 0x1d, 0x1e, 0x1d, 0x1e]),
  54             'DW_OP_mod; DW_OP_mul; DW_OP_mod; DW_OP_mul; DW_OP_mod; DW_OP_mul')
  55
  56         # 0xe0 maps to both DW_OP_GNU_push_tls_address and DW_OP_lo_user, so
  57         # check for both to prevent non-determinism.
  58         self.assertIn(self.visitor.dump_expr([0x08, 0x0f, 0xe0]),
  59                       ('DW_OP_const1u: 15; DW_OP_GNU_push_tls_address',
  60                        'DW_OP_const1u: 15; DW_OP_lo_user'))
  61
  62
  63 class TestParseExpr(unittest.TestCase):
  64     structs32 = DWARFStructs(
  65             little_endian=True,
  66             dwarf_format=32,
  67             address_size=4)
  68
  69     def setUp(self):
  70         set_global_machine_arch('x64')
  71
  72     def test_single(self):
  73         p = DWARFExprParser(self.structs32)
  74         lst = p.parse_expr([0x1b])
  75         self.assertEqual(lst, [DWARFExprOp(op=0x1B, op_name='DW_OP_div', args=[], offset=0)])
  76
  77         lst = p.parse_expr([0x90, 16])
  78         self.assertEqual(lst, [DWARFExprOp(op=0x90, op_name='DW_OP_regx', args=[16], offset=0)])
  79
  80         lst = p.parse_expr([0xe0])
  81         self.assertEqual(len(lst), 1)
  82         # 0xe0 maps to both DW_OP_GNU_push_tls_address and DW_OP_lo_user, so
  83         # check for both to prevent non-determinism.
  84         self.assertIn(lst[0], [
  85             DWARFExprOp(op=0xe0, op_name='DW_OP_GNU_push_tls_address', args=[], offset=0),
  86             DWARFExprOp(op=0xe0, op_name='DW_OP_lo_user', args=[], offset=0)])
  87
  88         # Real life example:
  89         # push_object_address
  90         # deref
  91         # dup
  92         # bra 4
  93         # lit0
  94         # skip 3
  95         # lit4
  96         # minus
  97         # deref
  98         lst = p.parse_expr([0x97,0x6,0x12,0x28,0x4,0x0,0x30,0x2F,0x3,0x0,0x34,0x1C,0x6])
  99         self.assertEqual(len(lst), 9)
 100         self.assertEqual(lst, [
 101             DWARFExprOp(op=0x97, op_name='DW_OP_push_object_address', args=[], offset=0),
 102             DWARFExprOp(op=0x6,  op_name='DW_OP_deref', args=[], offset=1),
 103             DWARFExprOp(op=0x12, op_name='DW_OP_dup', args=[], offset=2),
 104             DWARFExprOp(op=0x28, op_name='DW_OP_bra', args=[4], offset=3),
 105             DWARFExprOp(op=0x30, op_name='DW_OP_lit0', args=[], offset=6),
 106             DWARFExprOp(op=0x2f, op_name='DW_OP_skip', args=[3], offset=7),
 107             DWARFExprOp(op=0x34, op_name='DW_OP_lit4', args=[], offset=10),
 108             DWARFExprOp(op=0x1c, op_name='DW_OP_minus', args=[], offset=11),
 109             DWARFExprOp(op=0x6,  op_name='DW_OP_deref', args=[], offset=12)])
 110
 111
 112 if __name__ == '__main__':
 113     unittest.main()