[getdns-users] [PATCH] remove GETDNS_COMPILATION_COMMENT

[Willem Toorop]

Thanks Robert,

I think I prefer this.  If everybody here agrees I can put version
functions and defines in getdns_extra.h.  We can always move them to
getdns.h if the API list likes it this way too.

-- Willem


Op 08-07-15 om 21:57 schreef Robert Edmonds:
> Daniel Kahn Gillmor wrote:
>> We could also add a version info function without breaking backward API
>> compatibility, if the concern is that the cost of making a context and
>> parsing the response is too expensive.
> 
> I recently added version info capabilities to a C library that I
> maintain.  I based it on how libevent2 does it, which is to export
> library functions that return the version number as a string or encoded
> into a 32-bit integer.  libevent2 also exposes the same values as
> library headers.
> 
> [...]
>     /**
>        Get the Libevent version.
> 
>        Note that this will give you the version of the library that you're
>        currently linked against, not the version of the headers that you've
>        compiled against.
> 
>        @return a string containing the version number of Libevent
>     */
>     const char *event_get_version(void);
> 
>     /**
>        Return a numeric representation of Libevent's version.
> 
>        Note that this will give you the version of the library that you're
>        currently linked against, not the version of the headers you've used to
>        compile.
> 
>        The format uses one byte each for the major, minor, and patchlevel parts of
>        the version number.  The low-order byte is unused.  For example, version
>        2.0.1-alpha has a numeric representation of 0x02000100
>     */
>     ev_uint32_t event_get_version_number(void);
> 
>     /** As event_get_version, but gives the version of Libevent's headers. */
>     #define LIBEVENT_VERSION _EVENT_VERSION
>     /** As event_get_version_number, but gives the version number of Libevent's
>      * headers. */
>     #define LIBEVENT_VERSION_NUMBER _EVENT_NUMERIC_VERSION
> [...]
>     /* Version number of package */
>     #define _EVENT_VERSION "2.0.21-stable"
> [...]
>     /* Numeric representation of the version */
>     #define _EVENT_NUMERIC_VERSION 0x02001500
> [...]
> 
> So you get the version number in two different forms (string/numeric),
> and for both the headers that were used at compile time as well as the
> runtime library.
> 
> I'm not saying it's a good idea to rely on these for anything, but this
> seems to cover the use cases commonly requested by library users, at
> least IME.
> 
> +1 to reproducible builds.
>