[Rcpp-devel] Module compilation warnings with clang++/llvm

[Rich FitzJohn]

Hi List,

To follow up on the message below, the warnings are fixed in SVN.  The warnings from compiling with -Wconversion can be eliminated by being precice about differences between size_t, int, etc, but this is lots of small changes and won't make it in for the next release.

Cheers,
Rich

On 22/03/2013, at 11:11 AM, Dirk Eddelbuettel <edd at debian.org> wrote:

> 
> Hi Rich,
> 
> On 22 March 2013 at 10:18, Rich FitzJohn wrote:
> | Dear list,
> | 
> | When I compile Rcpp modules with clang, I see a number of warnings that seem to come from Rcpp.  Below is a small file containing a fairly useless module (test.cpp).  
> 
> "Stuff happens" :)
> 
> | test.cpp:
> | 
> | ---8<-----
> | 
> | #include <Rcpp.h>
> | 
> | class Foo {
> | public:
> |   Foo(double a) : a(a) {}
> |   double run(double b) { return a+b; }
> | private:
> |   double a;
> | };
> | 
> | RCPP_MODULE(test) {
> |   Rcpp::class_<Foo>("Foo")
> |     .constructor<double>()
> |     .method("run", &Foo::run);
> | }
> | 
> | ----->8---
> | 
> | 
> | Compiling this with sourceRcpp (though obviously that won't finish because no attributes) or through R CMD SHLIB (with a local Makevars file following the Rcpp FAQ) generates warnings:
> | 
> | clang++ -I/Library/Frameworks/R.framework/Resources/include -I/Library/Frameworks/R.framework/Resources/include/x86_64 -DNDEBUG -I/Library/Frameworks/R.framework/Versions/2.15/Resources/library/Rcpp/include -Wall -ansi -pedantic -I/usr/local/include    -fPIC  -O2 -Wall -c test.cpp -o test.o
> | In file included from test.cpp:1:
> | In file included from /Library/Frameworks/R.framework/Versions/2.15/Resources/library/Rcpp/include/Rcpp.h:48:
> | /Library/Frameworks/R.framework/Versions/2.15/Resources/library/Rcpp/include/Rcpp/XPtr.h:39:5: warning: delete called on
> |       'Rcpp::CppProperty<Foo>' that has virtual functions but non-virtual destructor [-Wdelete-non-virtual-dtor]
> 
> I think that one was just fixed in SVN a few days ago.
> 
> |     delete obj ;   
> |     ^
> | /Library/Frameworks/R.framework/Versions/2.15/Resources/library/Rcpp/include/Rcpp/XPtr.h:50:44: note: in instantiation of function
> |       template specialization 'Rcpp::standard_delete_finalizer<Rcpp::CppProperty<Foo> >' requested here
> | template <typename T, void Finalizer(T*) = standard_delete_finalizer<T> >
> |                                            ^
> | /Library/Frameworks/R.framework/Versions/2.15/Resources/library/Rcpp/include/Rcpp/module/class.h:392:26: note: in instantiation of member
> |       function 'Rcpp::S4_field<Foo>::S4_field' requested here
> |                 out[i] = S4_field<Class>( it->second, class_xp ) ; 
> |                          ^
> | test.cpp:12:3: note: in instantiation of member function 'Rcpp::class_<Foo>::fields' requested here
> |   Rcpp::class_<Foo>("Foo")
> |   ^
> | 1 warning generated.
> | g++ -dynamiclib -Wl,-headerpad_max_install_names -undefined dynamic_lookup -single_module -multiply_defined suppress -L/usr/local/lib -o test.so test.o /Library/Frameworks/R.framework/Versions/2.15/Resources/library/Rcpp/lib/x86_64/libRcpp.a -F/Library/Frameworks/R.framework/.. -framework R -Wl,-framework -Wl,CoreFoundation
> | 
> | If I increase the warnings to the level that CRAN are apparently using (changing CXXFLAGS to -O2 -Wall -pedantic -Wconversion) I get pages and pages of warnings (not pasted here).  So far as I can see, these come from Rcpp, but if I'm doing anything wrong, I'd appreciate any pointers.
> 
> Well, patches are always welcome. I develop mostly with whatever g++ version
> is current in the current Ubuntu release, right now g++ 4.7.2.  I do use
> -Wall -pedantic and try to keep it 'clean'.  I simply don't use the compiler
> you use all that much. So in that sense ... patches welcome.
> 
> Also, can you try the most current tarball from R-Forge [ goes checking ]
> Grr, once again no tarball available.  Could you test from SVN?  Else I can
> make the most recent tarball available from my site.
> 
> Dirk
> 
> | Versions and flag information below.
> | 
> | Thanks,
> | Rich
> | 
> | 
> | Makevars contains:
> | CXX=clang++
> | CC=clang
> | CXXFLAGS=-O2 -Wall
> | 
> | Versions:
> | 
> | Apple clang version 4.0 (tags/Apple/clang-421.0.57) (based on LLVM 3.1svn)
> | Target: x86_64-apple-darwin12.2.1
> | Thread model: posix
> | 
> | Mac OS X 10.8 (Mountain Lion), Xcode 4.5.1
> | 
> | sessionInfo:
> | R version 2.15.3 (2013-03-01)
> | Platform: x86_64-apple-darwin9.8.0/x86_64 (64-bit)
> | 
> | locale:
> | [1] en_AU.UTF-8/en_AU.UTF-8/en_AU.UTF-8/C/en_AU.UTF-8/en_AU.UTF-8
> | 
> | attached base packages:
> | [1] stats     graphics  grDevices utils     datasets  methods   base     
> | 
> | other attached packages:
> | [1] Rcpp_0.10.2
> | 
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> 
> -- 
> Dirk Eddelbuettel | edd at debian.org | http://dirk.eddelbuettel.com