On Sat, 7 Feb 2009, Thomas Petzoldt wrote:
Prof Brian Ripley schrieb:
We've added a column at
http://cran.r-project.org/web/checks/check_summary.html
of test results using the Sun Studio compiler: it is intended that these
will be updated weekly.
The Sun Studio compiler is that used on Solaris: these runs were on the
Linux version. All the other platforms are using gcc 4, so this provides
an opportunity for checking for use of gcc-specific features and also
standards conformance (the Sun compilers have a long-time reputation for
close conformance to the language standards).
There are known problems where packages use C++ or JNI interfaces (e.g.
rgdal and EBImage) as the libraries and JVM were compiled under gcc's
conventions (even though a Sun JVMi is used). About half the packages
using rJava segfault, which seems to a JNI issue.
Some packages use gcc-specific compiler flags:
LogConcDEAD Matching amap geometry memisc taskPR
but the vast majority of the errors reported are C++ errors. One class
that may not be immediately obvious is the use of C headers in C++: you are
supposed to write e.g.
#includd <cmath>
NOT
#include <math.h>
Symptoms of this can be seen for packages
BayesTree EMCC MCMCfglmm MarkedPointProcess Matching Matrix
RQuantlib RandomFields Rcpp SoPhy compHclust dpmix igraph minet
mixer modeest monomvm multic pcaPP rgenoud robfilter segclust
simecol subselect
The reason can also be including <R.h> (as done in simecol) that includes
<math.h>
As I said (R.h is a C header).
Do I understand it correctly that this means that including <R.h> is
wrong in C++? I read "Writing R extensions" several times, but was
not aware that this was a mistake. If I replace <R.h> by <cmath>
then it works on my systems, but I want to be certain that there are
no other side effects.
Hmm, I think you missed
Most @R{} header files can be included within C++ programs, and they
should @strong{not} be included within an @code{extern "C"} block
(as they include C++ system headers). It may not be possible to include
some @R{} headers as they in turn include C header files that may
cause conflicts---if this happens, define @samp{NO_C_HEADERS} before
including the @R{} headers, and include the appropriate headers
yourself.
Allowing R heeaders to be used in C++ was an afterthought: had it been
preplanned I expect R.h would have included far fewer C headers. The
issues have got worse as C++ has evolved (and diverged from C), and
until recently g++ has been well behind (g++ 4.3.x was a large step
forward towards C++ standards conformance).
Including unneeded headers often comes back to bite you (another area
is where the contents are controlled by macros such as __GNU_SOURCE__
and so order matters).
We did at one time experiment with R.h using cmath not math.h if
included into C++, but that too was not 100% portable.
--
Brian D. Ripley, rip...@stats.ox.ac.uk
Professor of Applied Statistics, http://www.stats.ox.ac.uk/~ripley/
University of Oxford, Tel: +44 1865 272861 (self)
1 South Parks Road, +44 1865 272866 (PA)
Oxford OX1 3TG, UK Fax: +44 1865 272595
______________________________________________
R-devel@r-project.org mailing list
https://stat.ethz.ch/mailman/listinfo/r-devel
