import unittest

from src.statement import Statement as S
from src.dataflow import BasicBlock as B, find_leaders, find_basic_blocks, \
        generate_flow_graph


class TestDataflow(unittest.TestCase):

    def setUp(self):
        add = S('command', 'add', '$1', '$2', '$3')
        self.statements = [add, S('command', 'j', 'foo'), add, add, \
                S('label', 'foo')]

    def tearDown(self):
        del self.statements

    def test_find_leaders(self):
        self.assertEqual(find_leaders(self.statements), [0, 2, 4])

    def test_find_basic_blocks(self):
        s = self.statements
        self.assertEqual(
                map(lambda b: b.statements, find_basic_blocks(s)[:-1]),
                [B(s[:2]).statements, B(s[2:4]).statements,
                    B(s[4:]).statements]
        )

    def test_generate_flow_graph_simple(self):
        b1 = B([S('command', 'foo'), S('command', 'j', 'b2')])
        b2 = B([S('label', 'b2'), S('command', 'bar')])
        generate_flow_graph([b1, b2])

        self.assertEqual(b1.edges_to, [b2])
        self.assertEqual(b2.edges_from, [b1])

    def test_generate_flow_graph_branch(self):
        b1 = B([S('command', 'foo'), S('command', 'beq', '$1', '$2', 'b3')])
        b2 = B([S('command', 'bar')])
        b3 = B([S('label', 'b3'), S('command', 'baz')])
        generate_flow_graph([b1, b2, b3])

        self.assertIn(b2, b1.edges_to)
        self.assertIn(b3, b1.edges_to)
        self.assertEqual(b2.edges_from, [b1])
        self.assertEqual(b2.edges_to, [b3])
        self.assertIn(b1, b3.edges_from)
        self.assertIn(b2, b3.edges_from)