tools/generate-wire.py: add option to expose tlv_record_type

Next update adds TLV test vectors: without this, we get a warning
about them being unused.

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>

tools/gen/header_template

@@ -61,6 +61,12 @@ struct ${tlv.struct_name()} {
 
 % for tlv in tlvs.values():
 struct ${tlv.struct_name()} *${tlv.struct_name()}_new(const tal_t *ctx);
+
+% if tlv.name in options.expose_tlv_type:
+#define TLVS_${tlv.name.upper()}_ARRAY_SIZE ${len(tlv.messages)}
+extern const struct tlv_record_type tlvs_${tlv.name}[];
+
+% endif
 % endfor
 % if options.expose_subtypes and bool(subtypes):
 % for subtype in subtypes:
@@ -87,4 +93,5 @@ u8 *towire_${msg.name}(const tal_t *ctx${''.join([f.arg_desc_to() for f in msg.f
 bool fromwire_${msg.name}(${'const tal_t *ctx, ' if msg.needs_context() else ''}const void *p${''.join([f.arg_desc_from() for f in msg.fields.values()])});
 
 % endfor
+
 #endif /* LIGHTNING_${idem} */

tools/gen/impl_template

@@ -200,7 +200,9 @@ static void fromwire_${msg.struct_name()}(const u8 **cursor, size_t *plen, void
 }
     % endfor
 
-static const struct tlv_record_type tlvs_${tlv.name}[] = {
+<% static = '' if tlv.name in options.expose_tlv_type else 'static '
+%>\
+${static}const struct tlv_record_type tlvs_${tlv.name}[] = {
     % for msg in tlv.messages.values():
 	{ ${msg.number}, towire_${msg.struct_name()}, fromwire_${msg.struct_name()} },
     % endfor

tools/generate-wire.py

@@ -628,6 +628,7 @@ if __name__ == "__main__":
     parser.add_argument("-P", "--print_wire", help="generate wire printing source files",
                         action="store_true", default=False)
     parser.add_argument("--page", choices=['header', 'impl'], help="page to print")
+    parser.add_argument('--expose-tlv-type', action='append', default=[])
     parser.add_argument('header_filename', help='The filename of the header')
     parser.add_argument('enum_name', help='The name of the enum to produce')
     parser.add_argument("files", help='Files to read in (or stdin)', nargs=REMAINDER)