[lustre-discuss] Compile a C++ app. using the Lustre API

[François Tessier]

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 :-)



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
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