[tools] Allow struct types in definitions

Allow struct type names in definitions, which result in struct buffer
pointers in generated code.

assets/grammars/definitions.g

@@ -24,10 +24,12 @@ method: description? "method" name options? ("{" param* "}")?
 
 param: "param" name type options? description?
 
-?type: PRIMITIVE | object_name
+?type: PRIMITIVE | object_name | struct_name
 
 object_name: "ref" name
 
+struct_name: "struct" name
+
 id: NUMBER
 name: IDENTIFIER
 options: "[" ( OPTION | IDENTIFIER )+ "]"

scripts/definitions/transformer.py

@@ -126,6 +126,11 @@ class DefTransformer(Transformer):
         from .types import ObjectRef
         return ObjectRef(n, self.filename)
 
+    @v_args(inline=True)
+    def struct_name(self, n):
+        from .types import Struct
+        return Struct(n)
+
     def PRIMITIVE(self, s):
         from .types import get_primitive
         return get_primitive(s)

scripts/definitions/types/__init__.py

@@ -24,3 +24,4 @@ from .function import Function, Method, Param
 from .type import Type
 from .primitive import get_primitive
 from .objref import ObjectRef
+from .struct import Struct

scripts/definitions/types/struct.py

@@ -0,0 +1,17 @@
+from .type import Type
+
+class Struct(Type):
+    def __repr__(self):
+        return f'Struct({self.name})'
+
+    def c_names(self, options):
+        one = f"struct j6_{self.name} *"
+        two = "size_t"
+
+        out = bool({"out", "inout"}.intersection(options))
+        if out:
+            two += " *"
+        return ((one, ""), (two, "_size"))
+
+    def cxx_names(self, options):
+        return self.c_names(options)

scripts/generate_parser.sh

@@ -0,0 +1,4 @@
+#!/usr/bin/env bash
+
+python3 -m lark.tools.standalone assets/grammars/definitions.g > scripts/definitions/parser.py
+python3 scripts/test_parse_definitions.py

scripts/test_parse_definitions.py

@@ -0,0 +1,10 @@
+import sys
+from pathlib import Path
+from definitions.context import Context
+
+root = Path(sys.argv[0]).parent.parent
+defs_path = (root / "definitions").resolve()
+print(f"Definitions: {defs_path}")
+ctx = Context(str(defs_path))
+ctx.parse("syscalls.def")
+