power_fields: restore class-oriented traversal
[openpower-isa.git] / src / openpower / decoder / power_fields.py
index 16e7fdff6d5fcc5f503d061595639b9b6072e92a..07dfe70b7df20aabdf6316a73211ffb80a7c4e43 100644 (file)
-from collections import OrderedDict, namedtuple
-from openpower.decoder.power_enums import find_wiki_file
+from collections import namedtuple
 
+import operator as _operator
+import functools as _functools
 
-class BitRange(OrderedDict):
-    """BitRange: remaps from straight indices (0,1,2..) to bit numbers
-    """
+from openpower.decoder.power_enums import find_wiki_file as _find_wiki_file
+from openpower.decoder.selectable_int import (
+    SelectableInt as _SelectableInt,
+    BitRange as _BitRange,
+    selectconcat as _selectconcat,
+    selectltu as _selectltu,
+)
 
-    def __getitem__(self, subscript):
-        if isinstance(subscript, slice):
-            return list(self.values())[subscript]
+
+class RemapError(ValueError):
+    pass
+
+
+class Descriptor:
+    def __init__(self, cls):
+        self.__cls = cls
+        return super().__init__()
+
+    def __get__(self, instance, owner):
+        if instance is None:
+            return self.__cls
+        return self.__cls(storage=instance.storage)
+
+    def __set__(self, instance, value):
+        if instance is None:
+            raise AttributeError("read-only attribute")
+        self.__cls(storage=instance.storage).assign(value)
+
+
+@_functools.total_ordering
+class Reference:
+    def __init__(self, storage, *args, **kwargs):
+        if not isinstance(storage, _SelectableInt):
+            raise ValueError(storage)
+
+        self.storage = storage
+
+        super().__init__()
+        self.__post_init__()
+
+    def __post_init__(self, *args, **kwargs):
+        _ = (args, kwargs)
+
+    def __binary_operator(self, op, other):
+        span = dict.fromkeys(self.__class__.span).keys()
+        lhs = _selectconcat(*(self.storage[bit] for bit in span))
+
+        if isinstance(other, Reference):
+            span = dict.fromkeys(other.__class__.span).keys()
+            rhs = _selectconcat(*(other.storage[bit] for bit in span))
+        elif isinstance(other, int):
+            bits = len(self.__class__)
+            if other.bit_length() > bits:
+                raise OverflowError(other)
+            rhs = _SelectableInt(value=other, bits=bits)
+        elif isinstance(other, _SelectableInt):
+            rhs = other
         else:
-            return OrderedDict.__getitem__(self, subscript)
+            raise ValueError(other)
+
+        return op(lhs, rhs)
+
+    def __lt__(self, other):
+        return self.__binary_operator(_selectltu, other)
+
+    def __eq__(self, other):
+        return self.__binary_operator(_operator.eq, other)
+
+    def __bool__(self):
+        return bool(int(self))
+
+    def __int__(self):
+        span = dict.fromkeys(self.__class__.span).keys()
+        return int(_selectconcat(*(self.storage[bit] for bit in span)))
+
+    def __index__(self):
+        return int(self).__index__()
+
+    @property
+    def storage(self):
+        return self.__storage
+
+    @storage.setter
+    def storage(self, storage):
+        if not isinstance(storage, _SelectableInt):
+            raise ValueError(storage)
+
+        self.__storage = storage
+
+    def assign(self, value):
+        if isinstance(value, int):
+            bits = len(self.__class__)
+            value = _SelectableInt(value=value, bits=bits)
+        if not isinstance(value, _SelectableInt):
+            raise ValueError(value)
+
+        span = frozenset(self.__class__.span)
+        for (src_bit, dst_bit) in enumerate(span):
+            self.storage[dst_bit] = value[src_bit]
+
+
+class FieldMeta(type):
+    def __new__(metacls, clsname, bases, ns, items=()):
+        assert "__members__" not in ns
+
+        members = []
+        for item in items:
+            if not isinstance(item, int):
+                raise ValueError(item)
+            if item < 0:
+                raise ValueError(item)
+            members.append(item)
+
+        ns["__members__"] = tuple(members)
+
+        return super().__new__(metacls, clsname, bases, ns)
+
+    def __repr__(cls):
+        if not cls.__members__:
+            return cls.__name__
+        return f"{cls.__name__}{cls.__members__!r}"
+
+    def __iter__(cls):
+        yield from cls.__members__
+
+    def __len__(cls):
+        return len(cls.__members__)
+
+    def __getitem__(cls, selector):
+        if isinstance(selector, int):
+            selector = (selector,)
+
+        items = []
+        for idx in selector:
+            if not isinstance(idx, int):
+                raise ValueError(selector)
+            item = cls.__members__[idx]
+            items.append(item)
+
+        return cls.__class__(cls.__name__, (Field,), {}, items=items)
+
+    def remap(cls, scheme):
+        if isinstance(scheme, type) and issubclass(scheme, Mapping):
+            scheme = range(len(scheme))
+        scheme = cls.__class__(cls.__name__, (cls,), {}, items=scheme)
+
+        if len(cls) == 0:
+            return scheme
+        elif len(cls) > len(scheme):
+            llen = f"len(scheme)"
+            rlen = f"len({cls.__name__})"
+            raise RemapError(f"{llen} != {rlen}")
+
+        ns = {}
+        ns["__doc__"] = cls.__doc__
+        items = map(lambda item: scheme.__members__[item], cls)
+
+        return cls.__class__(cls.__name__, (cls,), ns, items=items)
+
+    @property
+    def span(cls):
+        return cls.__members__
+
+
+class Field(Reference, metaclass=FieldMeta):
+    def __repr__(self):
+        return f"[{len(self.__class__)}]0x{int(self):x}"
+
+    def __iter__(self):
+        for bit in self.__class__:
+            yield self.storage[bit]
+
+    def __getitem__(self, key):
+        if isinstance(key, int):
+            bit = self.storage[self.__class__.__members__[key]]
+            return _SelectableInt(value=bit, bits=1)
+        if isinstance(key, slice):
+            assert key.step is None or key.step == 1
+            key = range(key.start, key.stop)
+
+        return _selectconcat(*(self[bit] for bit in tuple(key)))
+
+    @classmethod
+    def traverse(cls, path):
+        yield (path, cls.__members__)
+
+
+class MappingMeta(type):
+    def __new__(metacls, clsname, bases, ns):
+        members = {}
+
+        for cls in bases:
+            if isinstance(cls, metacls):
+                members.update(cls.__members__)
+
+        for (name, cls) in ns.get("__annotations__", {}).items():
+            if not (isinstance(cls, type) and
+                    issubclass(cls, (Mapping, Field))):
+                raise ValueError(f"{clsname}.{name}: {cls!r}")
+
+            if name in ns:
+                try:
+                    members[name] = cls.remap(ns[name])
+                except RemapError as error:
+                    raise RemapError(f"{name}: {error}")
+            else:
+                if cls is Field:
+                    raise ValueError(f"{clsname}.{name}: missing initializer")
+                members[name] = cls
+
+        ns["__members__"] = members
+        for (name, cls) in members.items():
+            ns[name] = Descriptor(cls)
+
+        return super().__new__(metacls, clsname, bases, ns)
+
+    def __repr__(cls):
+        return f"{cls.__name__}({cls.__members__!r})"
+
+    def __iter__(cls):
+        yield from cls.__members__.items()
+
+    def __len__(cls):
+        length = 0
+        for field in cls.__members__.values():
+            length = max(length, len(field))
+        return length
+
+    def __getitem__(cls, selector):
+        return cls.__members__["_"][selector]
+
+    def remap(cls, scheme):
+        ns = {}
+        annotations = {}
+
+        for (name, field) in cls:
+            annotations[name] = field.remap(scheme)
+        ns["__annotations__"] = annotations
+        ns["__doc__"] = cls.__doc__
+
+        return cls.__class__(cls.__name__, (cls,), ns)
+
+    @property
+    def span(cls):
+        for field in cls.__members__.values():
+            yield from field.span
+
+
+class Mapping(Reference, metaclass=MappingMeta):
+    def __init__(self, storage, **kwargs):
+        members = {}
+        for (name, cls) in self.__class__:
+            members[name] = cls(storage)
+
+        self.__members = members
+
+        return super().__init__(storage, **kwargs)
+
+    def __repr__(self):
+        items = tuple(f"{name}={field!r}" for (name, field) in self)
+        return f"{{{', '.join(items)}}}"
+
+    def __iter__(self):
+        yield from self.__members.items()
+
+    def __getitem__(self, key):
+        if isinstance(key, (int, slice, list, tuple, range)):
+            return self["_"][key]
+
+        return self.__members[key]
+
+    @classmethod
+    def traverse(cls, path):
+        for (name, member) in cls.__members__.items():
+            if name == "_":
+                yield from member.traverse(path=path)
+            elif path == "":
+                yield from member.traverse(path=name)
+            else:
+                yield from member.traverse(path=f"{path}.{name}")
 
 
 def decode_instructions(form):
@@ -108,7 +380,7 @@ def decode_form(form):
 
 class DecodeFields:
 
-    def __init__(self, bitkls=BitRange, bitargs=(), fname=None,
+    def __init__(self, bitkls=_BitRange, bitargs=(), fname=None,
                  name_on_wiki=None):
         self.bitkls = bitkls
         self.bitargs = bitargs
@@ -116,7 +388,7 @@ class DecodeFields:
             assert name_on_wiki is None
             fname = "fields.txt"
             name_on_wiki = "fields.text"
-        self.fname = find_wiki_file(name_on_wiki)
+        self.fname = _find_wiki_file(name_on_wiki)
 
     @property
     def form_names(self):
@@ -141,11 +413,12 @@ class DecodeFields:
             "FRT": self.FormX.FRT,
             "FRA": self.FormX.FRA,
             "FRB": self.FormX.FRB,
-            "FRC": self.FormX.FRB,
+            "FRC": self.FormA.FRC,
             "RS": self.FormX.RS,
             "RT": self.FormX.RT,
             "RA": self.FormX.RA,
             "RB": self.FormX.RB,
+            "RC": self.FormVA.RC,
             "SI": self.FormD.SI,
             "UI": self.FormD.UI,
             "L": self.FormD.L,