import sys, unittest
from cStringIO import StringIO

sys.path.extend(('..', '.'))
from elftools.dwarf.location_expr import LocationExpressionDumper
from elftools.dwarf.structs import DWARFStructs


class TestLocationExpressionDumper(unittest.TestCase):
    structs32 = DWARFStructs(
            little_endian=True,
            dwarf_format=32,
            address_size=4)

    def setUp(self):
        self.visitor = LocationExpressionDumper(self.structs32)

    def test_basic_single(self):
        self.visitor.process_expr([0x1b])
        self.assertEqual(self.visitor.get_str(),
            'DW_OP_div')
        
        self.setUp()
        self.visitor.process_expr([0x74, 0x82, 0x01])
        self.assertEqual(self.visitor.get_str(),
            'DW_OP_breg4: 130')
        
        self.setUp()
        self.visitor.process_expr([0x91, 0x82, 0x01])
        self.assertEqual(self.visitor.get_str(),
            'DW_OP_fbreg: 130')

        self.setUp()
        self.visitor.process_expr([0x9d, 0x8f, 0x0A, 0x90, 0x01])
        self.assertEqual(self.visitor.get_str(),
            'DW_OP_bit_piece: 1295 144')

    def test_basic_sequence(self):
        self.visitor.process_expr([0x03, 0x01, 0x02, 0, 0, 0x06, 0x06])
        self.assertEqual(self.visitor.get_str(),
            'DW_OP_addr: 201; DW_OP_deref; DW_OP_deref')

        self.setUp()
        self.visitor.process_expr([0x15, 0xFF, 0x0b, 0xf1, 0xff])
        self.assertEqual(self.visitor.get_str(),
            'DW_OP_pick: 255; DW_OP_const2s: -15')

        self.setUp()
        self.visitor.process_expr([0x1d, 0x1e, 0x1d, 0x1e, 0x1d, 0x1e])
        self.assertEqual(self.visitor.get_str(),
            'DW_OP_mod; DW_OP_mul; DW_OP_mod; DW_OP_mul; DW_OP_mod; DW_OP_mul')

    def test_stream_input(self):
        self.visitor.process_expr(StringIO('\x1b'))
        self.assertEqual(self.visitor.get_str(),
            'DW_OP_div')


if __name__ == '__main__':
    unittest.main()