tests/utils.py

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