nmigen/test/utils.py

   1 import os
   2 import re
   3 import shutil
   4 import subprocess
   5 import textwrap
   6 import traceback
   7 import unittest
   8 import warnings
   9 from contextlib import contextmanager
  10
  11 from ..hdl.ast import *
  12 from ..hdl.ir import *
  13 from ..back import rtlil
  14 from .._toolchain import require_tool
  15
  16
  17 __all__ = ["FHDLTestCase"]
  18
  19
  20 class FHDLTestCase(unittest.TestCase):
  21     def assertRepr(self, obj, repr_str):
  22         if isinstance(obj, list):
  23             obj = Statement.cast(obj)
  24         def prepare_repr(repr_str):
  25             repr_str = re.sub(r"\s+",   " ",  repr_str)
  26             repr_str = re.sub(r"\( (?=\()", "(", repr_str)
  27             repr_str = re.sub(r"\) (?=\))", ")", repr_str)
  28             return repr_str.strip()
  29         self.assertEqual(prepare_repr(repr(obj)), prepare_repr(repr_str))
  30
  31     def assertFormal(self, spec, mode="bmc", depth=1):
  32         caller, *_ = traceback.extract_stack(limit=2)
  33         spec_root, _ = os.path.splitext(caller.filename)
  34         spec_dir = os.path.dirname(spec_root)
  35         spec_name = "{}_{}".format(
  36             os.path.basename(spec_root).replace("test_", "spec_"),
  37             caller.name.replace("test_", "")
  38         )
  39
  40         # The sby -f switch seems not fully functional when sby is reading from stdin.
  41         if os.path.exists(os.path.join(spec_dir, spec_name)):
  42             shutil.rmtree(os.path.join(spec_dir, spec_name))
  43
  44         if mode == "hybrid":
  45             # A mix of BMC and k-induction, as per personal communication with Clifford Wolf.
  46             script = "setattr -unset init w:* a:nmigen.sample_reg %d"
  47             mode   = "bmc"
  48         else:
  49             script = ""
  50
  51         config = textwrap.dedent("""\
  52         [options]
  53         mode {mode}
  54         depth {depth}
  55         wait on
  56
  57         [engines]
  58         smtbmc
  59
  60         [script]
  61         read_ilang top.il
  62         prep
  63         {script}
  64
  65         [file top.il]
  66         {rtlil}
  67         """).format(
  68             mode=mode,
  69             depth=depth,
  70             script=script,
  71             rtlil=rtlil.convert(Fragment.get(spec, platform="formal"))
  72         )
  73         with subprocess.Popen([require_tool("sby"), "-f", "-d", spec_name], cwd=spec_dir,
  74                               universal_newlines=True,
  75                               stdin=subprocess.PIPE, stdout=subprocess.PIPE) as proc:
  76             stdout, stderr = proc.communicate(config)
  77             if proc.returncode != 0:
  78                 self.fail("Formal verification failed:\n" + stdout)