[kernel] Add automatic verification to syscalls

Since we have a DSL for specifying syscalls, we can create a verificaton
method for each syscall that can cover most argument (and eventually
capability) verification instead of doing it piecemeal in each syscall
implementation, which can be more error-prone.

Now a new _syscall_verify_* function exists for every syscall, which
calls the real implementation. The syscall table for the syscall handler
now maps to these verify functions.

Other changes:

- Updated the definition grammar to allow options to have a "key:value"
  style, to eventually support capabilities.
- Added an "optional" option for parameters that says a syscall will
  accept a null value.
- Some bonnibel fixes, as definition file changes weren't always
  properly causing updates in the build dep graph.
- The syscall implementation function signatures are no longer exposed
  in syscall.h. Also, the unused syscall enum has been removed.

scripts/definitions/context.py

@@ -34,6 +34,7 @@ class Context:
         pending = set()
         pending.add(filename)
 
+        from .parser import LarkError
         from .parser import Lark_StandAlone as Parser
         from .transformer import DefTransformer
 
@@ -47,7 +48,16 @@ class Context:
             path = self.find(name)
 
             parser = Parser(transformer=DefTransformer(name))
-            imps, objs, ints = parser.parse(open(path, "r").read())
+
+            try:
+                imps, objs, ints = parser.parse(open(path, "r").read())
+            except LarkError as e:
+                import sys
+                import textwrap
+                print(f"\nError parsing {name}:", file=sys.stderr)
+                print(textwrap.indent(str(e), "    "), file=sys.stderr)
+                sys.exit(1)
+
             objects.update(objs)
             interfaces.update(ints)
 

scripts/definitions/types/__init__.py

@@ -5,10 +5,15 @@ def _indent(x):
 class Description(str): pass
 class Import(str): pass
 
-class Options(set):
+class Options(dict):
+    def __init__(self, opts = tuple()):
+        for opt in opts:
+            parts = opt.split(":", 1)
+            self[parts[0]] = "".join(parts[1:])
+
     def __str__(self):
         if not self: return ""
-        return "[{}]".format(" ".join(self))
+        return "[{}]".format(" ".join(self.keys()))
 
 class UID(int):
     def __str__(self):

scripts/definitions/types/function.py

@@ -47,3 +47,15 @@ class Param:
         return "param {} {} {}  {}".format(
                 self.name, repr(self.type), self.options, self.desc or "")
 
+    @property
+    def outparam(self):
+        return "out" in self.options or "inout" in self.options
+
+    @property
+    def refparam(self):
+        return self.type.reference or self.outparam
+
+    @property
+    def optional(self):
+        return "optional" in self.options
+

scripts/definitions/types/primitive.py

@@ -8,9 +8,9 @@ class Primitive(Type):
     def __repr__(self):
         return f'Primitive({self.name})'
 
-    def c_names(self, options=None):
+    def c_names(self, options=dict()):
         one = self.c_type
-        if options and "out" in options or "inout" in options:
+        if "out" in options or "inout" in options:
             one += " *"
 
         return ((one, ""),)
@@ -23,11 +23,13 @@ class PrimitiveRef(Primitive):
         super().__init__(name, c_type)
         self.__counted = counted
 
-    def c_names(self, options=None):
+    reference = property(lambda self: True)
+
+    def c_names(self, options=dict()):
         one = f"{self.c_type} *"
         two = "size_t"
 
-        if options and "out" in options or "inout" in options:
+        if "out" in options or "inout" in options:
             two += " *"
         else:
             one = "const " + one

scripts/definitions/types/type.py

@@ -3,6 +3,7 @@ class Type:
         self.__name = name
 
     name = property(lambda self: self.__name)
+    reference = property(lambda self: False)
 
     def c_names(self, options):
         raise NotImplemented("Call to base Type.c_names")