[project] Generate syscalls from new interface DSL

This change adds a new interface DSL for specifying objects (with
methods) and interfaces (that expose objects, and optionally have their
own methods).

Significant changes:

- Add the new scripts/definitions Python module to parse the DSL
- Add the new definitions directory containing DSL definition files
- Use cog to generate syscall-related code in kernel and libj6
- Unify ordering of pointer + length pairs in interfaces

scripts/definitions/types/__init__.py

@@ -0,0 +1,23 @@
+def _indent(x):
+    from textwrap import indent
+    return indent(str(x), '    ')
+
+class Description(str): pass
+class Import(str): pass
+
+class Options(set):
+    def __str__(self):
+        if not self: return ""
+        return "[{}]".format(" ".join(self))
+
+class UID(int):
+    def __str__(self):
+        return f"{self:016x}"
+
+from .object import Object
+from .interface import Interface, Expose
+from .function import Function, Method, Param
+
+from .type import Type
+from .primitive import get_primitive
+from .objref import ObjectRef

scripts/definitions/types/function.py

@@ -0,0 +1,49 @@
+from . import _indent
+from . import Options
+
+def _hasopt(opt):
+    def test(self):
+        return opt in self.options
+    return test
+
+class Function:
+    typename = "function"
+
+    def __init__(self, name, opts=Options(), desc="", children=tuple()):
+        self.name = name
+        self.options = opts
+        self.desc = desc
+        self.params = [c for c in children if isinstance(c, Param)]
+        self.id = -1
+
+    def __str__(self):
+        parts = ["{} {}".format(self.typename, self.name)]
+        if self.desc:
+            parts.append(_indent(self.desc))
+        if self.options:
+            parts.append(f"    Options: {self.options}")
+        parts.extend(map(_indent, self.params))
+        return "\n".join(parts)
+
+    static = property(lambda x: True)
+    constructor = property(lambda x: False)
+
+
+class Method(Function):
+    typename = "method"
+
+    static = property(_hasopt("static"))
+    constructor = property(_hasopt("constructor"))
+
+
+class Param:
+    def __init__(self, name, typename, opts=Options(), desc=""):
+        self.name = name
+        self.type = typename
+        self.options = opts
+        self.desc = desc
+
+    def __str__(self):
+        return "param {} {} {}  {}".format(
+                self.name, repr(self.type), self.options, self.desc or "")
+

scripts/definitions/types/interface.py

@@ -0,0 +1,43 @@
+from . import _indent
+from . import Options
+
+class Expose(object):
+    def __init__(self, type):
+        self.type = type
+
+    def __repr__(self):
+        return f'expose {repr(self.type)}'
+
+class Interface:
+    def __init__(self, name, uid, opts=Options(), desc="", children=tuple()):
+        from .function import Function
+
+        self.name = name
+        self.uid = uid
+        self.options = opts
+        self.desc = desc
+
+        self.functions = [c for c in children if isinstance(c, Function)]
+        self.exposes = [e.type for e in children if isinstance(e, Expose)]
+
+    def __str__(self):
+        parts = [f"interface {self.name}: {self.uid}"]
+        if self.desc:
+            parts.append(_indent(self.desc))
+        if self.options:
+            parts.append(f"    Options: {self.options}")
+        parts.extend(map(_indent, self.exposes))
+        parts.extend(map(_indent, self.functions))
+        return "\n".join(parts)
+
+    def __methods(self):
+        mm = [(i, None, self.functions[i]) for i in range(len(self.functions))]
+
+        base = len(mm)
+        for o in [e.object for e in self.exposes]:
+            mm.extend([(base + i, o, o.methods[i]) for i in range(len(o.methods))])
+            base += len(o.methods)
+
+        return mm
+
+    methods = property(__methods)

scripts/definitions/types/object.py

@@ -0,0 +1,25 @@
+from . import _indent
+from . import Options
+
+class Object:
+    def __init__(self, name, uid, typename=None, opts=Options(), desc="", children=tuple()):
+        self.name = name
+        self.uid = uid
+        self.options = opts
+        self.desc = desc
+        self.super = typename
+        self.methods = children
+
+        from . import ObjectRef
+        self.__ref = ObjectRef(name)
+
+    def __str__(self):
+        parts = [f"object {self.name}: {self.uid}"]
+        if self.desc:
+            parts.append(_indent(self.desc))
+        if self.options:
+            parts.append(f"    Options: {self.options}")
+        parts.extend(map(_indent, self.methods))
+        return "\n".join(parts)
+
+    reftype = property(lambda self: self.__ref)

scripts/definitions/types/objref.py

@@ -0,0 +1,44 @@
+from .type import Type
+
+class ObjectRef(Type):
+    all_refs = {}
+
+    def __init__(self, name, filename=None):
+        super().__init__(name)
+        self.__c_type = "j6_handle_t"
+        self.__object = None
+        ObjectRef.all_refs[self] = filename
+
+    def __repr__(self):
+        return f'ObjectRef({self.name})'
+
+    object = property(lambda self: self.__object)
+
+    def c_names(self, options):
+        one = self.__c_type
+        out = bool({"out", "inout"}.intersection(options))
+
+        if "list" in options:
+            two = "size_t"
+            if out:
+                one = f"const {one} *"
+                two += " *"
+            else:
+                one = f"{one} *"
+            return ((one, ""), (two, "_count"))
+
+        else:
+            if out:
+                one += " *"
+            return ((one, ""),)
+
+    def cxx_names(self, options):
+        return self.c_names(options)
+
+    @classmethod
+    def connect(cls, objects):
+        for ref, filename in cls.all_refs.items():
+            ref.__object = objects.get(ref.name)
+            if ref.__object is None:
+                from ..errors import UnknownTypeError
+                raise UnknownTypeError(ref.name, filename)

scripts/definitions/types/primitive.py

@@ -0,0 +1,70 @@
+from .type import Type
+
+class Primitive(Type):
+    def __init__(self, name, c_type):
+        super().__init__(name)
+        self.c_type = c_type
+
+    def __repr__(self):
+        return f'Primitive({self.name})'
+
+    def c_names(self, options=None):
+        one = self.c_type
+        if options and "out" in options or "inout" in options:
+            one += " *"
+
+        return ((one, ""),)
+
+    def cxx_names(self, options):
+        return self.c_names(options)
+
+class PrimitiveRef(Primitive):
+    def __init__(self, name, c_type, counted=False):
+        super().__init__(name, c_type)
+        self.__counted = counted
+
+    def c_names(self, options=None):
+        one = f"{self.c_type} *"
+        two = "size_t"
+
+        if options and "out" in options or "inout" in options:
+            two += " *"
+        else:
+            one = "const " + one
+
+        if self.__counted:
+            return ((one, ""), (two, "_len"))
+        else:
+            return ((one, ""),)
+
+    def cxx_names(self, options):
+        return self.c_names(options)
+
+_primitives = {
+    "string": PrimitiveRef("string", "char"),
+    "buffer": PrimitiveRef("buffer", "void", counted=True),
+
+    "int": Primitive("int", "int"),
+    "uint": Primitive("uint", "unsigned"),
+    "size": Primitive("size", "size_t"),
+    "address": Primitive("address", "uintptr_t"),
+
+    "int8": Primitive("int8", "int8_t"),
+    "uint8": Primitive("uint8", "uint8_t"),
+
+    "int16": Primitive("int16", "int16_t"),
+    "uint16": Primitive("uint16", "uint16_t"),
+
+    "int32": Primitive("int32", "int32_t"),
+    "uint32": Primitive("uint32", "uint32_t"),
+
+    "int64": Primitive("int64", "int64_t"),
+    "uint64": Primitive("uint64", "uint64_t"),
+}
+
+def get_primitive(name):
+    p = _primitives.get(name)
+    if not p:
+        from ..errors import InvalidType
+        raise InvalidType(name)
+    return p

scripts/definitions/types/type.py

@@ -0,0 +1,12 @@
+class Type:
+    def __init__(self, name):
+        self.__name = name
+
+    name = property(lambda self: self.__name)
+
+    def c_names(self, options):
+        raise NotImplemented("Call to base Type.c_names")
+
+    def cxx_names(self, options):
+        raise NotImplemented("Call to base Type.c_names")
+