From bff4079f97e04cfc9d1c67f6226dda0fde81bef0 Mon Sep 17 00:00:00 2001 From: Andre Noll Date: Wed, 11 Sep 2019 22:52:52 +0200 Subject: [PATCH] send.h: Document cpp magic. These macros are not completely trivial, so give the interested reader an idea about how the macros help to avoid code duplication. --- send.h | 21 ++++++++++++++++++++- 1 file changed, 20 insertions(+), 1 deletion(-) diff --git a/send.h b/send.h index 67b47e48..8f7005cd 100644 --- a/send.h +++ b/send.h @@ -2,6 +2,10 @@ /** \file send.h Sender-related defines and structures. */ +/** + * A little preprocessor fu helps to create the sender_subcommand enumeration + * below and the list of sender name strings without duplicating the commands. + */ #define SENDER_SUBCOMMANDS \ SENDER_SUBCOMMAND(add) /**< Add a target (udp only). */ \ SENDER_SUBCOMMAND(delete) /**< Delete a target (udp only). */ \ @@ -10,12 +14,27 @@ SENDER_SUBCOMMAND(on) /**< Activate the sender. */ \ SENDER_SUBCOMMAND(off) /**< Deactivate the sender. */ \ +/** Concatenate "SENDER_" and the given arg and append a comma. */ #define SENDER_SUBCOMMAND(_name) SENDER_ ## _name, + +/** + * Each sender subcommand gets an SENDER_xxx identifier. The identifier is + * passed from the sender command handler to the server process via shared + * memory. + */ enum sender_subcommand { - SENDER_SUBCOMMANDS + SENDER_SUBCOMMANDS /**< List of SENDER_xxx identifiers. */ NUM_SENDER_CMDS /**< Used as array size in struct \ref sender. */ }; + #undef SENDER_SUBCOMMAND + +/** + * Redefine it to expand to the stringified name of the sender so that + * SENDER_SUBCOMMANDS above now expands to the comma-separated list of sender + * name strings. This is used in command.c to define and initialize an array of + * char pointers. + */ #define SENDER_SUBCOMMAND(_name) #_name, /** -- 2.39.2