lib9p: idl: Allow for const .cnt

1 files changed, 18 insertions, 6 deletions

diff --git a/lib9p/protogen/c_validate.py b/lib9p/protogen/c_validate.py
index e315b60..7d0c69e 100644
--- a/lib9p/protogen/c_validate.py
+++ b/lib9p/protogen/c_validate.py
@@ -132,21 +132,33 @@ def gen_c_validate(versions: set[str], typs: list[idl.UserType]) -> str:
         if should_save_offset(parent, child):
             ret += f"{'\t'*indent_lvl()}uint32_t offsetof{''.join('_'+m.membname for m in path.elems)} = net_offset + {incr_buf};\n"
         if child.cnt:
-            assert child.cnt.typ.static_size
-            cnt_path = path.parent().add(child.cnt)
-            incr_flush()
+            if isinstance(child.cnt, int):
+                cnt_str = str(child.cnt)
+                cnt_typ = "size_t"
+            else:
+                assert child.cnt.typ.static_size
+                incr_flush()
+                cnt_str = f"LAST_U{child.cnt.typ.static_size*8}LE()"
+                cnt_typ = c9util.typename(child.cnt.typ)
             if child.membname == "utf8":  # SPECIAL (string)
+                assert child.typ.static_size == 1
                 # Yes, this is content-validation and "belongs" in
                 # gen_validate_content(), not here.  But it's just
                 # easier this way.
-                ret += f"{'\t'*indent_lvl()}VALIDATE_NET_UTF8(LAST_U{child.cnt.typ.static_size*8}LE());\n"
+                incr_flush()
+                ret += f"{'\t'*indent_lvl()}VALIDATE_NET_UTF8({cnt_str});\n"
                 return
             if child.typ.static_size == 1:  # SPECIAL (zerocopy)
-                ret += f"{'\t'*indent_lvl()}VALIDATE_NET_BYTES(LAST_U{child.cnt.typ.static_size*8}LE());\n"
+                if isinstance(child.cnt, int):
+                    incr_buf += child.cnt
+                    return
+                incr_flush()
+                ret += f"{'\t'*indent_lvl()}VALIDATE_NET_BYTES({cnt_str});\n"
                 return
             loopdepth = sum(1 for elem in path.elems if elem.cnt)
             loopvar = chr(ord("i") + loopdepth - 1)
-            ret += f"{'\t'*indent_lvl()}for ({c9util.typename(child.cnt.typ)} {loopvar} = 0, cnt = LAST_U{child.cnt.typ.static_size*8}LE(); {loopvar} < cnt; {loopvar}++) {{\n"
+            incr_flush()
+            ret += f"{'\t'*indent_lvl()}for ({cnt_typ} {loopvar} = 0, cnt = {cnt_str}; {loopvar} < cnt; {loopvar}++) {{\n"
             indent_stack.append(IndentLevel(ifdef=False))
             ret += f"{'\t'*indent_lvl()}RESERVE_HOST_BYTES(sizeof({c9util.typename(child.typ)}));\n"
         if not isinstance(child.typ, idl.Struct):