[lustre-discuss] Compile a C++ app. using the Lustre API
Peter Jones
pjones at whamcloud.com
Fri Jul 5 18:05:05 PDT 2019
Rob
I can't see anything in flight from François in gerrit
Peter
On 2019-07-05, 3:31 PM, "lustre-discuss on behalf of Latham, Robert J." <lustre-discuss-bounces at lists.lustre.org on behalf of robl at mcs.anl.gov> wrote:
On Wed, 2017-03-22 at 12:12 +0000, Dilger, Andreas wrote:
> On Mar 21, 2017, at 15:53, François Tessier <ftessier at anl.gov> wrote:
> >
> > Hi Andreas,
> >
> > I removed the "static_cast" and casted the __u16 to an enum
> > changelog_rec_flags as suggested. It seems to work (see patch
> > attached).
> > Do you have a test to run to try this out?
>
> Hi François,
> thanks for the patch.
>
> Could you please submit it directly to Gerrit? Instructions for this
> are at:
> https://wiki.hpdd.intel.com/display/PUB/Using+Gerrit
> https://wiki.hpdd.intel.com/display/PUB/Commit+Comments
I ran into this problem today (buiding lustre_user.h with a c++
compiler). Do you know if François submitted this before he changed
jobs?
If he has not submitted it, I can do it, but if it's already in the
system I din't want to add more noise.
==rob
> Please feel free to ask here if you have any questions. Note that
> you need to add a
> Signed-off-by: line for contributions to Lustre and other open source
> projects.
>
> Once the patch is submitted to Gerrit, it will automatically be built
> on a variety of
> distros and kernels, and if that passes it will be tested with
> several configs as well.
>
> Since this is just a patch that affects the building of the code and
> not any functionality,
> please add the following line to your commit comment, just before the
> Signed-off-by: line:
>
> Test-Parameters: trivial
>
> so that it will only do minimal testing.
>
> Cheers, Andreas
>
> > On 03/19/2017 12:35 PM, Dilger, Andreas wrote:
> > > Unfortunately, that is not something we could include into the C
> > > header, since it would break compilation.
> > >
> > > What about just casting the __u16 to an enum changelog_rec_flags
> > > as needed, and declaring the local variables as the enum instead
> > > of an int?
> > >
> > > Failing that, if you don't need the ChangeLog support, we could
> > > #ifdef out that section of the header when compiling with
> > > __cplusplus so that at least the rest of the header is usable.
> > >
> > > Cheers, Andreas
> > >
> > > > On Mar 16, 2017, at 09:17, François Tessier <ftessier at anl.gov>
> > > > wrote:
> > > >
> > > > Here is the workaround I found (based on static_cast<>()):
> > > >
> > > > - make a local copy of lustre_user.h and lustreapi.h
> > > > - apply the attached patch on lustre_user.h
> > > > - add an include parameter in your CXXFLAGS pointing to these
> > > > files
> > > > - compile with CC
> > > >
> > > > It's clearly not the best solution but it's a working temporary
> > > > band-aid...
> > > >
> > > > ++
> > > >
> > > > François
> > > >
> > > >
> > > > > On 03/16/2017 07:44 AM, François Tessier wrote:
> > > > > > 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
> > > > > > > lustre-discuss at lists.lustre.org
> > > > > > >
http://lists.lustre.org/listinfo.cgi/lustre-discuss-lustre.org
> > > > > >
> > > > > > Cheers, Andreas
> > > > > > --
> > > > > > Andreas Dilger
> > > > > > Lustre Principal Architect
> > > > > > Intel Corporation
> > > > > >
> > > > > >
> > > > > >
> > > > > >
> > > > > >
> > > > > >
> > > > > >
> > > > >
> > > > > _______________________________________________
> > > > > lustre-discuss mailing list
> > > > > lustre-discuss at lists.lustre.org
> > > > >
http://lists.lustre.org/listinfo.cgi/lustre-discuss-lustre.org
> > > >
> > > > <lustre_user_cxx.patch>
> > > > _______________________________________________
> > > > lustre-discuss mailing list
> > > > lustre-discuss at lists.lustre.org
> > > > http://lists.lustre.org/listinfo.cgi/lustre-discuss-lustre.org
> >
> > <lustre_user_cxx.patch>
>
> Cheers, Andreas
> --
> Andreas Dilger
> Lustre Principal Architect
> Intel Corporation
>
>
>
>
>
>
>
> _______________________________________________
> lustre-discuss mailing list
> lustre-discuss at lists.lustre.org
> http://lists.lustre.org/listinfo.cgi/lustre-discuss-lustre.org
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