mirror of
https://github.com/servalproject/serval-dna.git
synced 2024-12-21 14:07:53 +00:00
67 lines
2.8 KiB
C
67 lines
2.8 KiB
C
|
/*
|
||
|
|
Serval DNA features
|
||
|
|
Copyright (C) 2016 Flinders University
|
||
|
|
|
||
|
|
This program is free software; you can redistribute it and/or
|
||
|
|
modify it under the terms of the GNU General Public License
|
||
|
|
as published by the Free Software Foundation; either version 2
|
||
|
|
of the License, or (at your option) any later version.
|
||
|
|
|
||
|
|
This program is distributed in the hope that it will be useful,
|
||
|
|
but WITHOUT ANY WARRANTY; without even the implied warranty of
|
||
|
|
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
|
||
|
|
GNU General Public License for more details.
|
||
|
|
|
||
|
|
You should have received a copy of the GNU General Public License
|
||
|
|
along with this program; if not, write to the Free Software
|
||
|
|
Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
|
||
|
|
*/
|
||
|
|
|
||
|
|
#ifndef __SERVAL_DNA__FEATURE_H
|
||
|
|
#define __SERVAL_DNA__FEATURE_H
|
||
|
|
|
||
|
|
/* These are macros for assembling an executable out of an explicitly-listed
|
||
|
|
* subset of "features". A feature is an object file (.o file) that contains
|
||
|
|
* the entire implementation of the feature, and is optional, ie, can be
|
||
|
|
* omitted from an executable without breaking the build.
|
||
|
|
*
|
||
|
|
* In Serval DNA, features are joined up with their infrastructure using
|
||
|
|
* linkage sections; see "sections.h" for more details.
|
||
|
|
*
|
||
|
|
* For example, a source file can add its own static function to the list of
|
||
|
|
* all URL path-to-function mappings for the HTTPD server using
|
||
|
|
* DECLARE_HANDLER() macro defined in "httpd.h". There is no
|
||
|
|
* explicitly-initialised array that lists all the URL paths; the array is
|
||
|
|
* constructed implicitly by the linker when it assembles the "httpd" section.
|
||
|
|
* Simply including the relevant object files in the link brings their
|
||
|
|
* functions into the array.
|
||
|
|
*
|
||
|
|
* Features are also used to add commands to the CLI interface and to add
|
||
|
|
* port-number handlers to the MDP interface.
|
||
|
|
*
|
||
|
|
* In order to build an executable from libservald.a, the executable needs a
|
||
|
|
* way to specify which optional features it wishes to link in, otherwise they
|
||
|
|
* will be omitted from the build, and as a result it will offer few or no CLI
|
||
|
|
* commands, no MDP services, and no HTTP services.
|
||
|
|
*
|
||
|
|
* Each source file that implements a feature must contain a DEFINE_FEATURE()
|
||
|
|
* macro, with the name of the feature as its argument.
|
||
|
|
*
|
||
|
|
* Every executable that links against libservald.a must contain a source file
|
||
|
|
* that invokes the USE_FEATURE() macro once for every defined feature it
|
||
|
|
* wishes to link in. This is typically done inside the main() function, but
|
||
|
|
* may be done within any function that is guaranteed to be included in the
|
||
|
|
* link.
|
||
|
|
*/
|
||
|
|
|
||
|
|
#define DEFINE_FEATURE(name) \
|
||
|
|
void _serval_feature__ ## name () {} \
|
||
|
|
|
||
|
|
#define USE_FEATURE(name) \
|
||
|
|
do { \
|
||
|
|
extern void _serval_feature__ ## name (); \
|
||
|
|
_serval_feature__ ## name (); \
|
||
|
|
} while (0)
|
||
|
|
|
||
|
|
#endif // __SERVAL_DNA__FEATURE_H
|