Send inn-workers mailing list submissions to
[email protected]
To subscribe or unsubscribe via the World Wide Web, visit
https://lists.isc.org/mailman/listinfo/inn-workers
or, via email, send a message with subject or body 'help' to
[email protected]
You can reach the person managing the list at
[email protected]
When replying, please edit your Subject line so it is more specific
than "Re: Contents of inn-workers digest..."
Today's Topics:
1. Re: Current gcc warnings on ia64, hppa and sparc (Russ Allbery)
2. Re: Current gcc warnings on ia64, hppa and sparc (Julien ?LIE)
----------------------------------------------------------------------
Message: 1
Date: Sat, 29 Jun 2013 15:08:17 -0700
From: Russ Allbery <[email protected]>
To: [email protected]
Subject: Re: Current gcc warnings on ia64, hppa and sparc
Message-ID: <[email protected]>
Content-Type: text/plain; charset=utf-8
Julien ?LIE <[email protected]> writes:
> network.c: In function 'network_sockaddr_sprint':
> network.c:648: warning: cast increases required alignment of target type
> network.c:662: warning: cast increases required alignment of target type
> network.c: In function 'network_sockaddr_equal':
> network.c:680: warning: cast increases required alignment of target type
> network.c:681: warning: cast increases required alignment of target type
> network.c:684: warning: cast increases required alignment of target type
> network.c:685: warning: cast increases required alignment of target type
> network.c:692: warning: cast increases required alignment of target type
> network.c:693: warning: cast increases required alignment of target type
> network.c: In function 'network_sockaddr_port':
> network.c:729: warning: cast increases required alignment of target type
> network.c:736: warning: cast increases required alignment of target type
These are all harmless. The complier just doesn't have enough information
to know that they're safe. They're all cases where the function takes a
generic struct sockaddr, checks sa_family, and based on the results, casts
the pointer to either struct sockaddr_in or struct sockaddr_in6. This is
guaranteed to be safe provided that the original structure was actually a
sockaddr_in or sockaddr_in6, matching its sa_family, and if that isn't
true, the caller has violated the socket API contract.
In the current rra-c-util, I've added (const void *) casts before the
final casts for all of those assignments to try to suppress the warnings,
as in:
sin6 = (const struct sockaddr_in6 *) (const void *) addr;
in network_sockaddr_sprint. However, I don't know if that actually worked
since I don't have a system that issues this warning on which I can easily
test.
(Unfortunately, it's not trivial to just resynchronize from rra-c-util for
this file because the INN version also has the innbind machinery. For
easier synchronization, that should be moved into another INN-specific
wrapper that calls into the generic code.)
> Test suite
> ----------
> ../lib/getaddrinfo.c: In function 'gai_addrinfo_new':
> ../lib/getaddrinfo.c:204: warning: cast increases required alignment of
> target type
> ../lib/getaddrinfo.c:205: warning: cast increases required alignment of
> target type
> ../lib/getaddrinfo.c:206: warning: cast increases required alignment of
> target type
> ../lib/getaddrinfo.c:207: warning: cast increases required alignment of
> target type
Same problem here, although the current rra-c-util hasn't tried to solve
it. However, this could be fixed through some restructuring of the code
so that it allocates the struct sockaddr_in separately and assigns
directly to it, and then stores the pointer in the ai->ai_addr struct
member instead of using casts. If I get a chance, I'll rewrite it that
way, since it makes the code somewhat more straightforward.
> lib/getaddrinfo-t.c: In function 'main':
> lib/getaddrinfo-t.c:74: warning: cast increases required alignment of target
> type
> lib/getaddrinfo-t.c:84: warning: cast increases required alignment of target
> type
> lib/getaddrinfo-t.c:97: warning: cast increases required alignment of target
> type
> lib/getaddrinfo-t.c:112: warning: cast increases required alignment of target
> type
> lib/getaddrinfo-t.c:138: warning: cast increases required alignment of target
> type
> lib/getaddrinfo-t.c:152: warning: cast increases required alignment of target
> type
> lib/getaddrinfo-t.c:165: warning: cast increases required alignment of target
> type
> lib/getaddrinfo-t.c:177: warning: cast increases required alignment of target
> type
> lib/getaddrinfo-t.c:193: warning: cast increases required alignment of target
> type
> lib/getaddrinfo-t.c:210: warning: cast increases required alignment of target
> type
> lib/getaddrinfo-t.c:220: warning: cast increases required alignment of target
> type
> lib/getaddrinfo-t.c:233: warning: cast increases required alignment of target
> type
> lib/getaddrinfo-t.c:256: warning: cast increases required alignment of target
> type
> lib/getaddrinfo-t.c:269: warning: cast increases required alignment of target
> type
These, on the other hand, are unavoidable and correct. Here too I don't
know if casting to void * first would suppress the warning.
> ../lib/getnameinfo.c: In function 'test_getnameinfo':
> ../lib/getnameinfo.c:151: warning: cast increases required alignment of
> target type
Same problem.
> lib/network-t.c: In function 'listener_any':
> lib/network-t.c:116: warning: cast increases required alignment of target type
Same problem.
> libtest.o(.text+0x408): In function `test_file_path':
> /home/iulius/autobuild/inn/inn2/inn-CURRENT-20130619/tests/libtest.c:563:
> warning: sprintf() is often misused, please use snprintf()
> runtests.o(.text+0x32c): In function `find_test':
> /home/iulius/autobuild/inn/inn2/inn-CURRENT-20130619/tests/runtests.c:929:
> warning: sprintf() is often misused, please use snprintf()
> lib/inet_ntoa.o(.text+0x3c): In function `test_inet_ntoa':
> ../lib/inet_ntoa.c:33: warning: sprintf() is often misused, please use
> snprintf()
> lib/messages-t.o(.text+0xdd4): In function `main':
> lib/messages-t.c:277: warning: sprintf() is often misused, please use
> snprintf()
> lib/snprintf-t.o(.text+0x5cc): In function `main':
> lib/snprintf-t.c:168: warning: sprintf() is often misused, please use
> snprintf()
These are all rather annoying since snprintf isn't fully portable or
guaranteed to be available, and all of this code is written to be
extremely portable (with the possible exception of lib/messages-t.c, which
could probably do without being this portable). lib/snprintf-t.c in
particular is comparing the results of the local snprintf against sprintf
to be sure that it works properly.
I'm not sure what I'm going to do when this error becomes widespread.
I'll probably consider just dropping support for any platform that doesn't
have a working snprintf in my code (which means, among other things,
Solaris 9, some versions of HP-UX 11, and some versions of IRIX 6.5). But
I kind of hate to do that. I suppose I could open-code a string
concatenation routine in runtests, but bleh.
All of the uses of sprintf above are, of course, safe.
--
Russ Allbery ([email protected]) <http://www.eyrie.org/~eagle/>
Please send questions to the list rather than mailing me directly.
<http://www.eyrie.org/~eagle/faqs/questions.html> explains why.
------------------------------
Message: 2
Date: Sun, 30 Jun 2013 13:16:22 +0200
From: Julien ?LIE <[email protected]>
To: [email protected]
Subject: Re: Current gcc warnings on ia64, hppa and sparc
Message-ID: <[email protected]>
Content-Type: text/plain; charset=UTF-8; format=flowed
Hi Russ,
> In the current rra-c-util, I've added (const void *) casts before the
> final casts for all of those assignments to try to suppress the warnings,
> as in:
>
> sin6 = (const struct sockaddr_in6 *) (const void *) addr;
>
> in network_sockaddr_sprint. However, I don't know if that actually worked
> since I don't have a system that issues this warning on which I can easily
> test.
I confirm it works. I have just tried the change on a system that
issues the warning; I confirm this warning is no longer returned.
Thanks, Russ.
>> lib/getaddrinfo-t.c: In function 'main':
>> lib/getaddrinfo-t.c:74: warning: cast increases required alignment of target
>> type
>
> These, on the other hand, are unavoidable and correct. Here too I don't
> know if casting to void * first would suppress the warning.
I also confirm that changing:
saddr = (struct sockaddr_in *) ai->ai_addr;
to:
saddr = (struct sockaddr_in *) (const void *) ai->ai_addr;
suppress the warning.
> All of the uses of sprintf above are, of course, safe.
OK, thanks for having had a look at them, and of course your answer.
Have a nice week,
--
Julien ?LIE
? Ne craignez pas d'?tre lent, craignez seulement d'?tre ?
l'arr?t. ?
------------------------------
_______________________________________________
inn-workers mailing list
[email protected]
https://lists.isc.org/mailman/listinfo/inn-workers
End of inn-workers Digest, Vol 52, Issue 10
*******************************************
