Clean up protocol code generators

xC-gen-proto.awk

@@ -22,7 +22,7 @@
 # unless this role is already filled by, e.g., WebSocket.
 #
 # Usage: env LC_ALL=C awk -f xC-gen-proto.awk -f xC-gen-proto-{c,go,js}.awk \
-#  xC-proto > xC-proto.{c,go,js} | {clang-format,gofmt,...}
+#  -v PrefixCamel=Relay xC-proto > xC-proto.{c,go,js} | {clang-format,gofmt,...}
 
 # --- Utilities ----------------------------------------------------------------
 
@@ -289,12 +289,14 @@ function deftype() {
 	return 0
 }
 
-BEGIN {
-	PrefixLower = "relay_"
-	PrefixUpper = "RELAY_"
-	PrefixCamel = "Relay"
+{
+	if (PrefixCamel) {
+		PrefixLower = tolower(cameltosnake(PrefixCamel)) "_"
+		PrefixUpper = toupper(cameltosnake(PrefixCamel)) "_"
+	}
 
-	print "// Generated by xC-gen-proto.awk. DO NOT MODIFY."
+	# This is not in a BEGIN clause (even though it consumes all input),
+	# so that the code generator can insert the first FILENAME.
 	codegen_begin()
 
 	nexttoken()