[Rcpp-devel] Rcpp bug (was: [Rd] Notes on building a gcc toolchain for Rtools (but not multilib))

Thu Mar 12 21:51:46 CET 2015

This is a minimum case to reproduce the crash (no Rcpp involved
*however* a C++ destructor being executed seems to be what triggers
the crash):

#include <R.h>
#include <Rinternals.h>

#include <string>

extern "C" SEXP foo(SEXP bar) {

  std::string str;

  Rf_error("foobar");
  return bar;
}

If I remove the "std::string str" line then it doesn't crash.

So it's something related to the interaction between longjmp and C++
destructors...

On Thu, Mar 12, 2015 at 4:39 PM, JJ Allaire <jj.allaire at gmail.com> wrote:
> Just noticed that Rcpp::stop also causes a hang on 64-bit R so the
> longjmp in the wrapper macro is having the same effect (good to be
> clear that the destructors being bypassed wasn't the source of the
> hang/crash)
>
>
> On Thu, Mar 12, 2015 at 4:25 PM, Avraham Adler <avraham.adler at gmail.com> wrote:
>> I believe the new toolchain uses SJLJ and not SEH specifically for backwards
>> compatibility.
>>
>> Avi
>>
>> On Thu, Mar 12, 2015 at 4:24 PM, JJ Allaire <jj.allaire at gmail.com> wrote:
>>>
>>> Just a note that Rf_error is actually not technically allowed in Rcpp
>>> (it's a longjmp which bypasses all C++ destructors on the stack). We
>>> do it as follows:
>>>
>>> Rcpp::stop("error message")
>>>
>>> Which throws an exception which is ultimately caught by our wrapper
>>> macro (which then calls Rf_error in a context where there are no more
>>> destructors).
>>>
>>>
>>>
>>> On Thu, Mar 12, 2015 at 4:16 PM, Dirk Eddelbuettel <edd at debian.org> wrote:
>>> >
>>> > Duncan,
>>> >
>>> > The preferred and widely-documented address for Rcpp issues is
>>> > rcpp-devel
>>> > where I am forwarding this, I would appreciate keeping follow-up there.
>>> >
>>> > On 12 March 2015 at 15:11, Duncan Murdoch wrote:
>>> > | Jack (and Dirk):
>>> > |
>>> > | I see this as well when I recompile Rcpp.
>>> > |
>>> > | Dirk:  We're seeing the Rgui console on Windows lock up in 64 bit
>>> > | Windows with a program calling Rf_error from Rcpp, but not from a
>>> > simple
>>> > | C program (attached) that looks equivalent.   This is using the new
>>> > | toolchain, both to compile Rcpp and Jack's cppFunction() call below.
>>> > |
>>> > | I'd be happy to help with debugging this, but not for a few days: I'll
>>> > | be out of the office until Wednesday next week, and I don't have 64
>>> > bit
>>> > | Windows when I'm on the road.
>>> >
>>> > Sure.  We can pick this up when you are back.  The change vector appears
>>> > to
>>> > be on your side of the fence so we need access from your end. Few of us
>>> > (on
>>> > the Rcpp core group) use Windows all that much.
>>> >
>>> > I think I saw a blog post mentioned where someone said that with g++
>>> > 4.9.2
>>> > (though possibly a different build/configuration/...) some
>>> > exception-related
>>> > behaviour was improved.  I am sure that something is different now, and
>>> > we
>>> > will try to accomodate it.
>>> >
>>> > Safe travels.
>>> >
>>> > Dirk
>>> >
>>> > |
>>> > | Duncan Murdoch
>>> > |
>>> > | On 12/03/2015 2:54 PM, Duncan Murdoch wrote:
>>> > | > On 12/03/2015 1:31 PM, Jack Wasey wrote:
>>> > | > > Dear Duncan,
>>> > | > >
>>> > | > > I hope you don't mind me emailing you directly, rather than
>>> > through
>>> > | > > r-devel, since it seemed a very specific problem. I had just sent
>>> > an
>>> > | > > email to the list when it crossed with yours saying you had
>>> > released a
>>> > | > > new Rtools, so I pulled my r-devel email. I have a probable R,
>>> > | > > possible Rcpp bug causing a hang with Rf_error("stop") after
>>> > showing
>>> > | > > the error message, but only with 64 bit Rtools 3.3 (downloaded a
>>> > few
>>> > | > > hours ago).
>>> > | > >
>>> > | > > I'm afraid my reproducible example uses Rcpp, but only for
>>> > | > > compilation. I'm not adept enough to eliminate the Rcpp step
>>> > quickly,
>>> > | > > but I hope it will be of use anyway.
>>> > | > >
>>> > | > > Rcpp::cppFunction("void doError() { Rf_error(\"stopping\"); }")
>>> > | > > doError()
>>> > | > >
>>> > | > > This causes a hang after showing the error message. Winbuilder
>>> > checked
>>> > | > > my package "icd9" without problems in 32 bit R-devel, and both 32
>>> > and
>>> > | > > 64 bit R current.
>>> > | > >
>>> > | > > Not being sure whether this is an Rcpp or R bug (see also
>>> > | > > https://github.com/RcppCore/Rcpp/issues/276), I hesitated to
>>> > report
>>> > | > > this as a bug against R itself, but perhaps people more skilled
>>> > than
>>> > | > > me can do this if indeed it is so.
>>> > | >
>>> > | > I see the same problem.  I've just tried the equivalent as a simple
>>> > C
>>> > | > program, and it was fine.  I will try compiling Rcpp and see if that
>>> > | > fixes it; I wouldn't be surprised if the binary on CRAN was built
>>> > with
>>> > | > the old compiler.
>>> > | >
>>> > | > Duncan Murdoch
>>> > | > >
>>> > | > > Best wishes,
>>> > | > > Jack
>>> > | > >
>>> > | > > On Thu, Mar 12, 2015 at 1:17 PM, Duncan Murdoch
>>> > | > > <murdoch.duncan at gmail.com> wrote:
>>> > | > > > I've just uploaded a minor update (3.3.0.1957) to Rtools33,
>>> > adding the
>>> > | > > > cygpath.exe utility.  That utility converts between Windows
>>> > style paths like
>>> > | > > > D:/Rtools and Cygwin style paths like /cygdrive/d/Rtools.   It
>>> > may be useful
>>> > | > > > in configuration files if your external library expects to find
>>> > gcc on the
>>> > | > > > path, since Rtools no longer puts it there.  Assuming you want
>>> > to use the
>>> > | > > > Rtools toolchain, you can construct the path to the gcc
>>> > directory in your
>>> > | > > > Makevars.win file as
>>> > | > > >
>>> > | > > > $(cygpath $(RTOOLS))gcc492_$(WIN)/bin
>>> > | > > >
>>> > | > > > (where RTOOLS and WIN are macros from RHOME/etc/*/Makeconf that
>>> > should
>>> > | > > > already have been read.)
>>> > | > > >
>>> > | > > > Thanks to JJ Allaire for the prompting on this.
>>> > | > > >
>>> > | > > > Duncan Murdoch
>>> > | > > >
>>> > | > > > ______________________________________________
>>> > | > > > R-devel at r-project.org mailing list
>>> > | > > > https://stat.ethz.ch/mailman/listinfo/r-devel
>>> > | >
>>> > |
>>> > | [DELETED ATTACHMENT test.c, plain text]
>>> >
>>> > --
>>> > http://dirk.eddelbuettel.com | @eddelbuettel | edd at debian.org
>>> > _______________________________________________
>>> > Rcpp-devel mailing list
>>> > Rcpp-devel at lists.r-forge.r-project.org
>>> > https://lists.r-forge.r-project.org/cgi-bin/mailman/listinfo/rcpp-devel
>>> _______________________________________________
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>>
>>