summaryrefslogtreecommitdiffstats
path: root/Lib/test/support/bytecode_helper.py
blob: 190fe8723b1fb571f92dd99ce025899f0053d71c (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
"""bytecode_helper - support tools for testing correct bytecode generation"""

import unittest
import dis
import io
from _testinternalcapi import compiler_codegen, optimize_cfg

_UNSPECIFIED = object()

class BytecodeTestCase(unittest.TestCase):
    """Custom assertion methods for inspecting bytecode."""

    def get_disassembly_as_string(self, co):
        s = io.StringIO()
        dis.dis(co, file=s)
        return s.getvalue()

    def assertInBytecode(self, x, opname, argval=_UNSPECIFIED):
        """Returns instr if opname is found, otherwise throws AssertionError"""
        self.assertIn(opname, dis.opmap)
        for instr in dis.get_instructions(x):
            if instr.opname == opname:
                if argval is _UNSPECIFIED or instr.argval == argval:
                    return instr
        disassembly = self.get_disassembly_as_string(x)
        if argval is _UNSPECIFIED:
            msg = '%s not found in bytecode:\n%s' % (opname, disassembly)
        else:
            msg = '(%s,%r) not found in bytecode:\n%s'
            msg = msg % (opname, argval, disassembly)
        self.fail(msg)

    def assertNotInBytecode(self, x, opname, argval=_UNSPECIFIED):
        """Throws AssertionError if opname is found"""
        self.assertIn(opname, dis.opmap)
        for instr in dis.get_instructions(x):
            if instr.opname == opname:
                disassembly = self.get_disassembly_as_string(x)
                if argval is _UNSPECIFIED:
                    msg = '%s occurs in bytecode:\n%s' % (opname, disassembly)
                    self.fail(msg)
                elif instr.argval == argval:
                    msg = '(%s,%r) occurs in bytecode:\n%s'
                    msg = msg % (opname, argval, disassembly)
                    self.fail(msg)

class CompilationStepTestCase(unittest.TestCase):

    HAS_ARG = set(dis.hasarg)
    HAS_TARGET = set(dis.hasjrel + dis.hasjabs + dis.hasexc)
    HAS_ARG_OR_TARGET = HAS_ARG.union(HAS_TARGET)

    class Label:
        pass

    def assertInstructionsMatch(self, actual_, expected_):
        # get two lists where each entry is a label or
        # an instruction tuple. Normalize the labels to the
        # instruction count of the target, and compare the lists.

        self.assertIsInstance(actual_, list)
        self.assertIsInstance(expected_, list)

        actual = self.normalize_insts(actual_)
        expected = self.normalize_insts(expected_)
        self.assertEqual(len(actual), len(expected))

        # compare instructions
        for act, exp in zip(actual, expected):
            if isinstance(act, int):
                self.assertEqual(exp, act)
                continue
            self.assertIsInstance(exp, tuple)
            self.assertIsInstance(act, tuple)
            # crop comparison to the provided expected values
            if len(act) > len(exp):
                act = act[:len(exp)]
            self.assertEqual(exp, act)

    def resolveAndRemoveLabels(self, insts):
        idx = 0
        res = []
        for item in insts:
            assert isinstance(item, (self.Label, tuple))
            if isinstance(item, self.Label):
                item.value = idx
            else:
                idx += 1
                res.append(item)

        return res

    def normalize_insts(self, insts):
        """ Map labels to instruction index.
            Map opcodes to opnames.
        """
        insts = self.resolveAndRemoveLabels(insts)
        res = []
        for item in insts:
            assert isinstance(item, tuple)
            opcode, oparg, *loc = item
            opcode = dis.opmap.get(opcode, opcode)
            if isinstance(oparg, self.Label):
                arg = oparg.value
            else:
                arg = oparg if opcode in self.HAS_ARG else None
            opcode = dis.opname[opcode]
            res.append((opcode, arg, *loc))
        return res


class CodegenTestCase(CompilationStepTestCase):

    def generate_code(self, ast):
        insts = compiler_codegen(ast, "my_file.py", 0)
        return insts


class CfgOptimizationTestCase(CompilationStepTestCase):

    def complete_insts_info(self, insts):
        # fill in omitted fields in location, and oparg 0 for ops with no arg.
        res = []
        for item in insts:
            assert isinstance(item, tuple)
            inst = list(reversed(item))
            opcode = dis.opmap[inst.pop()]
            oparg = inst.pop() if opcode in self.HAS_ARG_OR_TARGET else 0
            loc = inst + [-1] * (4 - len(inst))
            res.append((opcode, oparg, *loc))
        return res

    def get_optimized(self, insts, consts):
        insts = self.normalize_insts(insts)
        insts = self.complete_insts_info(insts)
        insts = optimize_cfg(insts, consts)
        return insts, consts