nmigen/_utils.py

   1 import contextlib
   2 import functools
   3 import warnings
   4 import linecache
   5 import re
   6 from collections import OrderedDict
   7 from collections.abc import Iterable
   8 from contextlib import contextmanager
   9
  10 from .utils import *
  11
  12
  13 __all__ = ["flatten", "union" , "log2_int", "bits_for", "memoize", "final", "deprecated",
  14            "get_linter_options", "get_linter_option"]
  15
  16
  17 def flatten(i):
  18     for e in i:
  19         if isinstance(e, Iterable):
  20             yield from flatten(e)
  21         else:
  22             yield e
  23
  24
  25 def union(i, start=None):
  26     r = start
  27     for e in i:
  28         if r is None:
  29             r = e
  30         else:
  31             r |= e
  32     return r
  33
  34
  35 def memoize(f):
  36     memo = OrderedDict()
  37     @functools.wraps(f)
  38     def g(*args):
  39         if args not in memo:
  40             memo[args] = f(*args)
  41         return memo[args]
  42     return g
  43
  44
  45 def final(cls):
  46     def init_subclass():
  47         raise TypeError("Subclassing {}.{} is not supported"
  48                         .format(cls.__module__, cls.__name__))
  49     cls.__init_subclass__ = init_subclass
  50     return cls
  51
  52
  53 def deprecated(message, stacklevel=2):
  54     def decorator(f):
  55         @functools.wraps(f)
  56         def wrapper(*args, **kwargs):
  57             warnings.warn(message, DeprecationWarning, stacklevel=stacklevel)
  58             return f(*args, **kwargs)
  59         return wrapper
  60     return decorator
  61
  62
  63 def _ignore_deprecated(f=None):
  64     if f is None:
  65         @contextlib.contextmanager
  66         def context_like():
  67             with warnings.catch_warnings():
  68                 warnings.filterwarnings(action="ignore", category=DeprecationWarning)
  69                 yield
  70         return context_like()
  71     else:
  72         @functools.wraps(f)
  73         def decorator_like(*args, **kwargs):
  74             with warnings.catch_warnings():
  75                 warnings.filterwarnings(action="ignore", category=DeprecationWarning)
  76                 f(*args, **kwargs)
  77         return decorator_like
  78
  79
  80 def extend(cls):
  81     def decorator(f):
  82         if isinstance(f, property):
  83             name = f.fget.__name__
  84         else:
  85             name = f.__name__
  86         setattr(cls, name, f)
  87     return decorator
  88
  89
  90 def get_linter_options(filename):
  91     first_line = linecache.getline(filename, 1)
  92     if first_line:
  93         match = re.match(r"^#\s*nmigen:\s*((?:\w+=\w+\s*)(?:,\s*\w+=\w+\s*)*)\n$", first_line)
  94         if match:
  95             return dict(map(lambda s: s.strip().split("=", 2), match.group(1).split(",")))
  96     return dict()
  97
  98
  99 def get_linter_option(filename, name, type, default):
 100     options = get_linter_options(filename)
 101     if name not in options:
 102         return default
 103
 104     option = options[name]
 105     if type is bool:
 106         if option in ("1", "yes", "enable"):
 107             return True
 108         if option in ("0", "no", "disable"):
 109             return False
 110         return default
 111     if type is int:
 112         try:
 113             return int(option, 0)
 114         except ValueError:
 115             return default
 116     assert False