[petsc-dev] Hijacked MPI calls...

[Satish Balay]

Ok I used your notation - and (void) only for the stuff inside while/for loops.

https://bitbucket.org/petsc/petsc/pull-requests/561/balay-clang-wcomma/diff


Satish

On Tue, 13 Sep 2016, Barry Smith wrote:

> 
>    I just had a bad experience with (void) so feel it is only a half-answer.
> 
> 
> > On Sep 13, 2016, at 10:45 AM, Satish Balay <balay at mcs.anl.gov> wrote:
> > 
> > On Tue, 13 Sep 2016, Barry Smith wrote:
> > 
> >> 
> >>> On Sep 13, 2016, at 10:13 AM, Satish Balay <balay at mcs.anl.gov> wrote:
> >>> 
> >>> There is stuff like:
> >>> 
> >>> src/mat/order/fn1wd.c
> >>> 
> >>> -    kstop = (i__2 = xadj[node + 1], (PetscInt)PetscAbsInt(i__2)) - 1;
> >>> +    kstop = (PetscInt)PetscAbsInt(xadj[node + 1]) - 1;
> >>> 
> >>> Perhaps PetscAbsInt() type stuff should be switched over to static inline?
> >>> Or use a different notation?
> >>> 
> >>> i__2  = xadj[node + 1];
> >>> kstop = (PetscInt)PetscAbsInt(i__2) - 1;
> >> 
> >>   This is the way any normal person would write it :-)
> > 
> > I think the first one is what is more intutive. The second one is
> > clearly encoding an optimization - as the code is aware PetscAbsInt()
> > is a macro - not a proper function. Hence the thought about 'static inline'
> > 
> > The first change compiles fine [with clang - both c, complex - but
> > don't know if there are problem compilers]
> > 
> > I'm now inclined to just preserve the current usage with void:
> > 
> >    kstop = ((void)(i__2 = xadj[node + 1]), (PetscInt)PetscAbsInt(i__2)) - 1;
> > 
> >> 
> >>> 
> >>> And for the following - use 'void' as compiler suggests?
> >>> 
> >>> a/src/mat/utils/pheap.c
> >>> -  while (par = Parent(loc), Value(h,par) > val) {
> >>> +  while ((void)(par = Parent(loc)), Value(h,par) > val) {
> >>> 
> >>> a/src/dm/impls/plex/plexdistribute.c
> >>> -      for (q = 0; q < numAdj || (adj[numAdj++] = support[s],0); ++q) {
> >>> +      for (q = 0; q < numAdj || ((void)(adj[numAdj++] = support[s]),0); ++q) {
> >> 
> >>   Does the (void) work to eliminate the warning?
> > 
> > yes.
> > 
> > Satish
> > 
> >> 
> >>  Barry
> >> 
> >>> 
> >>> 
> >>> And this one is perhaps for Matt..
> >>> 
> >>>>>>>>>>>>>>>>>>>>>> 
> >>>         CC arch-clang-cmplx/obj/src/dm/impls/composite/pack.o
> >>> /home/balay/petsc/src/dm/impls/composite/pack.c:657:17: warning: passing an object that undergoes default argument promotion to 'va_start' has undefined behavior [-Wvarargs]
> >>> va_start(Argp,imode);
> >>>               ^
> >>> /home/balay/petsc/src/dm/impls/composite/pack.c:641:61: note: parameter of type 'InsertMode' is declared here
> >>> PetscErrorCode  DMCompositeGather(DM dm,Vec gvec,InsertMode imode,...)
> >>>                                                           ^
> >>> 1 warning generated.
> >>> <<<<<<<<<<<<<<<<<
> >>> 
> >>> 
> >>> 
> >>> Satish
> >>> 
> >>> On Mon, 12 Sep 2016, Barry Smith wrote:
> >>> 
> >>>> 
> >>>> Satish,
> >>>> 
> >>>>  Interesting. We can probably get rid of most of the other warnings easily; it looks like mostly frivolous use of the , notation.
> >>>> 
> >>>>  Barry
> >>>> 
> >>>>> On Sep 12, 2016, at 11:19 PM, Satish Balay <balay at mcs.anl.gov> wrote:
> >>>>> 
> >>>>> The attached patch gets rid of most of the warnings [esp MPI usage
> >>>>> from PETSc code - with the logging wrappers].
> >>>>> 
> >>>>> [also added to balay/clang-Wcomma]
> >>>>> 
> >>>>> Satish
> >>>>> 
> >>>>> On Mon, 12 Sep 2016, Satish Balay wrote:
> >>>>> 
> >>>>>> ok - so you are using CFLAGS=-Wcomma on your build..
> >>>>>> 
> >>>>>> I see warnings now. Attaching make.log
> >>>>>> 
> >>>>>> Satish
> >>>>>> 
> >>>>>> On Mon, 12 Sep 2016, Eric Chamberland wrote:
> >>>>>> 
> >>>>>>> 
> >>>>>>> 
> >>>>>>> Le 2016-09-12 à 17:32, Satish Balay a écrit :
> >>>>>>>> Do you get these warnings with PETSc library build aswell?
> >>>>>>> I can't tell since I didn't tried to build PETSc with clang...
> >>>>>>>> 
> >>>>>>>> The logging code tries to log all messages in library and in
> >>>>>>>> application - and prints a summary with -info.
> >>>>>>>> 
> >>>>>>>> You can disable logging in your build with configure option: --with-log=0
> >>>>>>>> 
> >>>>>>>> Or you can define the PETSC_HAVE_BROKEN_RECURSIVE_MACRO in your
> >>>>>>>> code/compile - and the wrappers will be skipped..
> >>>>>>> ok, so these may be good workaround for me to keep -Wcomma activated on our
> >>>>>>> "push server" that filters incoming commits...
> >>>>>>> 
> >>>>>>> Thanks!!!
> >>>>>>> 
> >>>>>>> Eric
> >>>>>>> 
> >>>>>>> 
> >>>>>>> 
> >>>>>> 
> >>>>> <clang-Wcomma.patch><make.log>
> 
>