Small note: if you are using a recent version of OSX, then gdb is essentially useless, but you can use llvm, which is nicer in many respects, anyway.
Gabor On Fri, Jan 17, 2014 at 3:43 AM, Gabriel Becker <gmbec...@ucdavis.edu>wrote: > Saisai, > > I haven't watched the specific video Sandip posted, but from the title it > looks to be correct. Running R with/in gdb is the correct way to debug C > code in R packages. > > One thing to watch out for: The default compiler flags for C/C++ code in R > packages call for substantial optimization (I believe it's '-O2'). This > mess with the execution order of some instructions, making step by step > debugging annoying. Also, it will optimize out values that may be important > to your debugging. To fix this you'll need to look into how Makevars files > work, and specifically how to set/override compiler flags in them. > > There were some deeper issues with what you asked, though. Sourcing an R > file will have no effect on a package in the namespace at all unless you > are using something like ESS's developer mode which sources the file into > the package namespace. Furthermore, C code included in R packages is only > compiled at installation from source or binary build time. > > Even if you are using a developer mode, sourcing an R file will have no > effect on a) the shared object library (DLL/so/dylib) available in the R > session, nor which shared objects are associated with the package. There > are ways to unload shared libraries within an R session, but personally I > tend to avoid them. The best way of being absolutely sure that the right > shared library is getting used is to reinstall the package, then close the > R session and restart. > > I would encourage you to look into how R compiles and interacts with native > code in and out of packages before trying to tackle something like this > directly. It's all in the Writing R extensions manual here: > http://cran.r-project.org/doc/manuals/R-exts.html > > Hope that helps, > ~G > > > On Thu, Jan 16, 2014 at 8:04 PM, Sandip Nandi <sanna...@umail.iu.edu> > wrote: > > > Hi , > > > > The video may help you > > > > http://vimeo.com/11937905 > > > > Thanks, > > Sandip > > > > > > On Thu, Jan 16, 2014 at 4:17 PM, Ma, Saisai - maysy020 < > > saisai...@mymail.unisa.edu.au> wrote: > > > > > Hi all, > > > > > > Sorry to bother you. > > > > > > I am a beginner in R programming. I have encountered some problems > when I > > > modified a R package with C code. > > > I would like to modified the C code within the R package, and want to > > > debug the C program. But I have no idea how to debug this kind of R > > package. > > > > > > In the package, a R file named aaa.R use the interface .call(bbb.c, > ...) > > > to call the C code named bbb.c. > > > And what I did is that I resourced aaa.R and ran it in R Stdio again, > > > after modifying bbb.c. But there is nothing happened. > > > I am very sure that the all the path of R file and C file is correct. > And > > > I am using Windows operating system. > > > > > > Could anyone give me a few pointers on how to debug R packages (or > > > extensions with C++/C code)? If possible, Could you please give me an > > > simple example or some command lines? > > > > > > > > > Regards, > > > Saisai > > > > > > > > > [[alternative HTML version deleted]] > > > > > > ______________________________________________ > > > R-devel@r-project.org mailing list > > > https://stat.ethz.ch/mailman/listinfo/r-devel > > > > > > > [[alternative HTML version deleted]] > > > > ______________________________________________ > > R-devel@r-project.org mailing list > > https://stat.ethz.ch/mailman/listinfo/r-devel > > > > > > -- > Gabriel Becker > Graduate Student > Statistics Department > University of California, Davis > > [[alternative HTML version deleted]] > > ______________________________________________ > R-devel@r-project.org mailing list > https://stat.ethz.ch/mailman/listinfo/r-devel > [[alternative HTML version deleted]] ______________________________________________ R-devel@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-devel
