diff mbox

Add comment to gethnamaddr.c to warn that the file is unmaintained

Message ID 20140701140726.GB20796@spoyarek.pnq.redhat.com
State Committed
Headers show

Commit Message

Siddhesh Poyarekar July 1, 2014, 2:07 p.m. UTC
On Mon, Jun 30, 2014 at 11:34:14AM -0400, Carlos O'Donell wrote:
> On 06/30/2014 01:59 AM, Siddhesh Poyarekar wrote:
> > On Fri, Jun 27, 2014 at 09:34:19PM -0700, Roland McGrath wrote:
> >> I guess for now the inconsistency just makes me want to have the other code
> >> forks around as documentation.  I suppose comments would do it just as
> >> well.  Still my inclination is to make these something like:
> >>
> >> /* Insert long new comment about the weirdness and referring to the other
> >>    file where the opposite fork is used in equivalent code.  */
> >> #if 0 /* was MULTI_PTRS_ARE_ALIASES */
> > 
> > After reading further, I don't think there is any inconsistency in
> > functionality.  The gethostbyaddr function also uses the dns-host.c
> > bits and gethnamaddr.c is currently not used at all.  The only
> > reference it has is in resolv/README:
> > 
> >     The files gethnamaddr.c, mapv4v6addr.h and mapv4v6hostent.h are
> >     leftovers from BIND 4.9.7.
> > 
> > Given this newly discovered fact, how about the following patch
> > instead?  I don't modify gethnamaddr.c because it's not even used.  I
> > wonder - given that we have decided to own the resolver bits now - if
> > we should just get rid of gethnamaddr.c and other unused files.  I
> > could add a note in the README mentioning this.
> > 
> > Siddhesh
> > 
> > 	* resolv/nss_dns/dns-host.c (getanswer_r)
> > 	[MULTI_PTRS_ARE_ALIASES]: Remove code.
> 
> I'm OK with this v2, but if you're up for it I'd like to remove
> gethnameaddr.c and update README. If we don't use the code it
> should be immediately removed to prevent future confusion.

Looks like it can't be removed.  The file is linked into libresolv.so
and it exports some _gethst* and res_gethost* functions, that are not
documented so I'm assuming we don't knowingly support them.  All
changes to the file seem to be general bulk changes.  How about just
adding this comment to the file instead?

Siddhesh

	* resolv/gethnamaddr.c: Add comment warning that the file is
	not maintained.

Comments

Andreas Schwab July 1, 2014, 2:23 p.m. UTC | #1
Siddhesh Poyarekar <siddhesh@redhat.com> writes:

> Looks like it can't be removed.  The file is linked into libresolv.so
> and it exports some _gethst* and res_gethost* functions, that are not
> documented so I'm assuming we don't knowingly support them.

I think we should deprecate these interfaces then.

Andreas.
Carlos O'Donell July 1, 2014, 6:39 p.m. UTC | #2
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Hash: SHA1

On 07/01/2014 10:07 AM, Siddhesh Poyarekar wrote:
> On Mon, Jun 30, 2014 at 11:34:14AM -0400, Carlos O'Donell wrote:
>> On 06/30/2014 01:59 AM, Siddhesh Poyarekar wrote:
>>> On Fri, Jun 27, 2014 at 09:34:19PM -0700, Roland McGrath wrote:
>>>> I guess for now the inconsistency just makes me want to have the other code
>>>> forks around as documentation.  I suppose comments would do it just as
>>>> well.  Still my inclination is to make these something like:
>>>>
>>>> /* Insert long new comment about the weirdness and referring to the other
>>>>    file where the opposite fork is used in equivalent code.  */
>>>> #if 0 /* was MULTI_PTRS_ARE_ALIASES */
>>>
>>> After reading further, I don't think there is any inconsistency in
>>> functionality.  The gethostbyaddr function also uses the dns-host.c
>>> bits and gethnamaddr.c is currently not used at all.  The only
>>> reference it has is in resolv/README:
>>>
>>>     The files gethnamaddr.c, mapv4v6addr.h and mapv4v6hostent.h are
>>>     leftovers from BIND 4.9.7.
>>>
>>> Given this newly discovered fact, how about the following patch
>>> instead?  I don't modify gethnamaddr.c because it's not even used.  I
>>> wonder - given that we have decided to own the resolver bits now - if
>>> we should just get rid of gethnamaddr.c and other unused files.  I
>>> could add a note in the README mentioning this.
>>>
>>> Siddhesh
>>>
>>> 	* resolv/nss_dns/dns-host.c (getanswer_r)
>>> 	[MULTI_PTRS_ARE_ALIASES]: Remove code.
>>
>> I'm OK with this v2, but if you're up for it I'd like to remove
>> gethnameaddr.c and update README. If we don't use the code it
>> should be immediately removed to prevent future confusion.
> 
> Looks like it can't be removed.  The file is linked into libresolv.so
> and it exports some _gethst* and res_gethost* functions, that are not
> documented so I'm assuming we don't knowingly support them.  All
> changes to the file seem to be general bulk changes.  How about just
> adding this comment to the file instead?

OK, in which case if the interface is exported we must continue to
export the interface for libresolv.so.

> Siddhesh
> 
> 	* resolv/gethnamaddr.c: Add comment warning that the file is
> 	not maintained.
> 
> diff --git a/resolv/gethnamaddr.c b/resolv/gethnamaddr.c
> index c73a0dc..49cdc72 100644
> --- a/resolv/gethnamaddr.c
> +++ b/resolv/gethnamaddr.c
> @@ -49,6 +49,11 @@
>   * --Copyright--
>   */
>  
> +/* XXX This file is not used by any of the resolver functions implemented by
> +   glibc (i.e. get*info and gethostby*).  It cannot be removed however because
> +   it exports symbols in the libresolv ABI.  The file is not maintained any
> +   more, nor are these functions.  */
> +

OK by me.

>  #if defined(LIBC_SCCS) && !defined(lint)
>  static char sccsid[] = "@(#)gethostnamadr.c	8.1 (Berkeley) 6/4/93";
>  #endif /* LIBC_SCCS and not lint */
> 

Cheers,
Carlos.
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Carlos O'Donell July 1, 2014, 6:42 p.m. UTC | #3
On 07/01/2014 10:23 AM, Andreas Schwab wrote:
> Siddhesh Poyarekar <siddhesh@redhat.com> writes:
> 
>> Looks like it can't be removed.  The file is linked into libresolv.so
>> and it exports some _gethst* and res_gethost* functions, that are not
>> documented so I'm assuming we don't knowingly support them.
> 
> I think we should deprecate these interfaces then.

I'm not opposed to that, however, someone needs to think deeply about
this and the applications the might use these interfaces. Seems like
a bad thing to do just before a freeze.

Cheers,
Carlos.
Andreas Schwab July 2, 2014, 10:19 a.m. UTC | #4
"Carlos O'Donell" <carlos@redhat.com> writes:

> On 07/01/2014 10:23 AM, Andreas Schwab wrote:
>> Siddhesh Poyarekar <siddhesh@redhat.com> writes:
>> 
>>> Looks like it can't be removed.  The file is linked into libresolv.so
>>> and it exports some _gethst* and res_gethost* functions, that are not
>>> documented so I'm assuming we don't knowingly support them.
>> 
>> I think we should deprecate these interfaces then.
>
> I'm not opposed to that, however, someone needs to think deeply about
> this and the applications the might use these interfaces.

Of the 68 packages (out of 22462) in openSUSE:Factory that depend on
libresolv.so.2 none of them reference any of the symbols exported from
that file.

> Seems like a bad thing to do just before a freeze.

Sure, that's 2.21 material.

Andreas.
diff mbox

Patch

diff --git a/resolv/gethnamaddr.c b/resolv/gethnamaddr.c
index c73a0dc..49cdc72 100644
--- a/resolv/gethnamaddr.c
+++ b/resolv/gethnamaddr.c
@@ -49,6 +49,11 @@ 
  * --Copyright--
  */
 
+/* XXX This file is not used by any of the resolver functions implemented by
+   glibc (i.e. get*info and gethostby*).  It cannot be removed however because
+   it exports symbols in the libresolv ABI.  The file is not maintained any
+   more, nor are these functions.  */
+
 #if defined(LIBC_SCCS) && !defined(lint)
 static char sccsid[] = "@(#)gethostnamadr.c	8.1 (Berkeley) 6/4/93";
 #endif /* LIBC_SCCS and not lint */