Re: backend functions declaration

[Howard Chu <hyc@symas.com>]

Hallvard B Furuseth wrote:

> Pierangelo Masarati writes:
>  
>
> > As a consequence of looking at ITS#3387, I note that many backends declare
> > the function handlers (usually in a dedicated external.h header).  This is
> > not required, since all the frontend needs to know (for statically
> > compiled backends) is the <backend>_initialize() function; runtime loaded
> > backends don't even need it.  An exception are those backends that have
> > cross-dependencies (e.g. back-ldap and back-meta, back-bdb and back-hdb).
> >
> > I'd like to remove all of this, to avoid confusion and maintenance overhead.
> >    
>
> Sounds good.  Just make sure that the .h file(s) which declare the
> *_initialize() which backend.c uses, are also read by the backend .c
> files that define the *_initialize() functions.
>  
I must have misunderstood the first message. If we're just talking about 
eliminating "external.h" because the frontend doesn't need it and the 
backend declares its functions in a separate file already (such as 
proto-bdb.h) then yes, I agree.

> BTW, this is the kind of thing that I like to code as follows
> (untested), though I don't know how others feel about such hacks:
>  
I like them when they're harmless and save typing. In this case, I don't 
see much savings.

> /* backend.h - expand SLAPD_BACKEND(name, initializer) for static backends */
>
> /* Default SLAPD_BACKEND: Declare the initializer */
> #ifndef SLAPD_BACKEND
> #define SLAPD_BACKEND(name, initializer) extern BI_init name;
> #endif
>
> #if SLAPD_BDB == SLAPD_MOD_STATIC
> 	SLAPD_BACKEND("bdb",    bdb_initialize)
> #endif
> ...
> 	/* for any private backend */
> #if SLAPD_PRIVATE == SLAPD_MOD_STATIC
> 	SLAPD_BACKEND("private",private_back_initialize)
> #endif
>
> #undef SLAPD_BACKEND
>
> /* backend.c */
> ...
> #include "backend.h"
>
> static BackendInfo binfo[] = {
> #	define  SLAPD_BACKEND(name, initializer) {name, initializer},
> #	include "backend.h"
> 	{NULL}
> };
> ...
>
> (Nitpick: I don't know what kind of macros should be named SLAPD_* and
> what kind should be named SLAP_*.)
--
 -- Howard Chu
 Chief Architect, Symas Corp.       Director, Highland Sun
 http://www.symas.com               http://highlandsun.com/hyc
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