[lustre-discuss] Compile a C++ app. using the Lustre API
François Tessier
ftessier at anl.gov
Thu Mar 16 05:44:55 PDT 2017
On 03/15/2017 05:50 PM, Dilger, Andreas wrote:
> On Mar 15, 2017, at 15:22, François Tessier <ftessier at anl.gov> wrote:
>> I get the same errors with g++ (v. 6.3). I can't find what kind of compiler flag I can use to be able to compile this. It clearly comes from how C++ deals with enum. The solutions I've found consist in "static_casting" the int values... Modifying my local version of lustre_user.h is probably not the best idea :-)
> Have you tried adding the standard wrappers at the start and end of the lustre_user.h header:
>
> #ifdef __cplusplus
> extern "C" {
> #endif
> :
> <rest of header>
> #ifdef __cplusplus
> }
> #endif
>
> I thought we had added those long ago, but I don't see them in the header today. If that fixes your problem, please file an LU ticket at https://jira.hpdd.intel.com/ (and ideally a patch at https://review.whamcloud.com/ too) and we can get this added to the header.
>
> In the meantime, you could also wrap your "#include <lustre/lustre_user.h>" similarly.
It doesn't fix the problem. I tried a more recent version of g++ or
several compiler options to force the use of C++11 [1] but with no success.
> Cheers, Andreas
Cheers,
François
[1] http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2007/n2347.pdf
>> On 03/15/2017 02:14 PM, Patrick Farrell wrote:
>>> It looks like your compiler is being fussier than the C compiler.
>>>
>>> Specifically, the problem appears to be with the enum type. The C compiler is happy to let pass using a short (cr_flags) where an enum is called for (argument to changelog_rec_offset). In C, I think an enum is an int (so passing in a short like this is always fine). I guess in C++ either enum is not an int, or it's just fussier.
>>>
>>> There might be a compiler flag to make it not error on this? I am not familiar with icpc, so I can't help with specifics.
>>>
>>> You might also try a different C++ compiler, to see if it has a different attitude towards that error.
>>>
>>> One further thought, though:
>>> This is a C header. Presumably, it is not intended to be included directly in a C++ project?
>>>
>>> - Patrick
>>> From: lustre-discuss <lustre-discuss-bounces at lists.lustre.org> on behalf of François Tessier <ftessier at anl.gov>
>>> Sent: Wednesday, March 15, 2017 2:00:31 PM
>>> To: lustre-discuss at lists.lustre.org
>>> Subject: [lustre-discuss] Compile a C++ app. using the Lustre API
>>>
>>> Hi All,
>>>
>>> I'm working on a piece of code using the Lustre API. To do so, I include
>>> lustreapi.h. When I compile my code with a C compiler (icc), everything
>>> is fine. However, when I compile it with a C++ compiler (icpc), I get
>>> these errors:
>>>
>>> ---------------------------------
>>>
>>> In file included from /usr/include/lustre/lustreapi.h(47),
>>> from topo.c(5):
>>> /usr/include/lustre/lustre_user.h(914): error: argument of type "__u16={unsigned short}" is incompatible with parameter of type "changelog_rec_flags"
>>> return changelog_rec_offset(rec->cr_flags);
>>> ^
>>>
>>> In file included from /usr/include/lustre/lustreapi.h(47),
>>> from topo.c(5):
>>> /usr/include/lustre/lustre_user.h(925): error: a value of type "int" cannot be used to initialize an entity of type "changelog_rec_flags"
>>> enum changelog_rec_flags crf = rec->cr_flags & CLF_VERSION;
>>> ^
>>>
>>> In file included from /usr/include/lustre/lustreapi.h(47),
>>> from topo.c(5):
>>> /usr/include/lustre/lustre_user.h(935): error: a value of type "int" cannot be used to initialize an entity of type "changelog_rec_flags"
>>> enum changelog_rec_flags crf = rec->cr_flags &
>>> ^
>>>
>>> In file included from /usr/include/lustre/lustreapi.h(47),
>>> from topo.c(5):
>>> /usr/include/lustre/lustre_user.h(945): error: argument of type "int" is incompatible with parameter of type "changelog_rec_flags"
>>> return (char *)rec + changelog_rec_offset(rec->cr_flags &
>>> ^
>>>
>>> In file included from /usr/include/lustre/lustreapi.h(47),
>>> from topo.c(5):
>>> /usr/include/lustre/lustre_user.h(986): error: this operation on an enumerated type requires an applicable user-defined operator function
>>> crf_wanted &= CLF_SUPPORTED;
>>> ^
>>>
>>> In file included from /usr/include/lustre/lustreapi.h(47),
>>> from topo.c(5):
>>> /usr/include/lustre/lustre_user.h(997): error: argument of type "int" is incompatible with parameter of type "changelog_rec_flags"
>>> changelog_rec_offset(crf_wanted & ~CLF_JOBID);
>>> ^
>>>
>>> In file included from /usr/include/lustre/lustreapi.h(47),
>>> from topo.c(5):
>>> /usr/include/lustre/lustre_user.h(999): error: argument of type "int" is incompatible with parameter of type "changelog_rec_flags"
>>> changelog_rec_offset(crf_wanted & ~(CLF_JOBID | CLF_RENAME));
>>> ^
>>>
>>> Makefile:10: recipe for target 'topo' failed
>>> make: *** [topo] Error 2
>>>
>>> ---------------------------------
>>>
>>> It's probably more a compiler issue than a Lustre one but a solution
>>> could help other users or Lustre developers.
>>>
>>> Any idea?
>>>
>>> Thanks,
>>>
>>> François
>>>
>>>
>>> --
>>> --
>>> François TESSIER, Ph.D.
>>> Postdoctoral Appointee
>>> Argonne National Laboratory
>>> LCF Division - Bldg 240, 4E 19
>>> Tel : +1 (630)-252-5068
>>> http://www.francoistessier.info
>>>
>>> _______________________________________________
>>> lustre-discuss mailing list
>>> lustre-discuss at lists.lustre.org
>>> http://lists.lustre.org/listinfo.cgi/lustre-discuss-lustre.org
>> _______________________________________________
>> lustre-discuss mailing list
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>> http://lists.lustre.org/listinfo.cgi/lustre-discuss-lustre.org
> Cheers, Andreas
> --
> Andreas Dilger
> Lustre Principal Architect
> Intel Corporation
>
>
>
>
>
>
>
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