Hi, Some extra information on the problem that I described in my previous post, and which I suspect to be a bug in MinGW-w64 for 64-bit platform.
I attach a sample testcase, which I compile with: x86_64-w64-mingw32-gcc -g -O2 -fexceptions -Wall -shared -I~/MATLAB/extern/include mextest.c -o mextest.mexw64 -L~MATLAB/bin/win64 -lmex The libmex.dll contains both mexErrMsgTxt() and mexPrintf(). As such, the example makes MATLAB crash. But if I comment out the second function call (mexPrintf()), then the DLL behaves as expected: MATLAB catches the exception thrown by mexErrMsgTxt(), and displays the error message. It is very strangs since having or not the mexPrintf() should not change the result, since it is never reached. So it looks like a compiler bug, unless I’m missing something ? I’m not familiar with exception unwinding, so please forgive my ignorance. Any idea ? Best regards, On Wed, Sep 01, 2010 at 02:38:52PM +0200, Sébastien Villemot wrote: > Hi, > > I’m a developer of Dynare [1], an open-source GPL’d project which runs on top > of GNU Octave and alternatively on top of the commercial software MATLAB. > > I’ve been using mingw-w64 for compiling DLLs loaded from Octave/MATLAB (these > DLLs are called “MEX files” in the MATLAB terminology), and your work at > mingw-w64 helps me a lot, for both the 32-bit and 64-bit platforms (I can now > get rid of MS Visual C++). > > However, there is still an issue that I can’t solve by myself, hence this > e-mail : I keep getting crashes on the 64-bit platform (but not on 32-bit) > when > exceptions are thrown by the DLL and should be catched by MATLAB (note that > there is no 64-bit build of Octave as of today, so I can’t test the problem > with it). > > More precisely, I have a DLL (here called “mjdgges.mexw64”) which is called by > MATLAB. Under normal circumstances, this DLL works fine. But in some cases > where it is necessary to display an error message, my DLL calls a MATLAB > primitive (which resides in another DLL provided by MATLAB), to generate an > exception which should be catched by top-level MATLAB. > > So the calling graph is: MATLAB -> mjdgges.mexw64 -> libmex.dll. > > The exception is generated by libmex.dll, then propagated to mjdgges.mexw64 > and > then to MATLAB, which should catch it. > > Under 32-bit (i.e. a 32-bit Windows, a 32-bit MATLAB, and a Win32 targeted > mingw-w64), this works fine. But under 64-bit (i.e. a 64-bit Windows, a 64-bit > MATLAB, and a Win64 targeted mingw-w64), MATLAB crashes. Also note that if I > compile the DLL with MS Visual C++ for x64, the problem does not occur. > > Using GDB, it seems that MATLAB crashes because of an illegal instruction from > within ntdll!RtlRaiseStatus(). I don’t know if this is very reliable > information. > > Note that since the “mjdgges.mexw64” DLL is C code, I compile and link it with > “-fexceptions”. Also note that the problem occurs both with and without > “-static-libgcc”. I use automated builds of Mingw-w64 cross-compiler from > Linux > (I tried both the stable version [2] and the development version [3]). > > Any ideas of how to fix this ? Do you have any guidelines to help debug this ? > Thanks in advance. > > Best regards, > > [1] http://www.dynare.org > [2] mingw-w64-1.0-bin_x86_64-linux_20100823.tar.bz2 > [3] mingw-w64-bin_x86_64-linux_20100830.tar.bz2 > > -- > Sébastien Villemot > CEPREMAP — http://www.cepremap.ens.fr > Dynare project — http://www.dynare.org > Phone: +33 1 40 77 49 90 > PGP Key: 0xA6C029B9D06B2913D71C105EBE37E801FB6EFF8B (http://pgp.mit.edu/) > ------------------------------------------------------------------------------ > This SF.net Dev2Dev email is sponsored by: > > Show off your parallel programming skills. > Enter the Intel(R) Threading Challenge 2010. > http://p.sf.net/sfu/intel-thread-sfd > _______________________________________________ > Mingw-w64-public mailing list > [email protected] > https://lists.sourceforge.net/lists/listinfo/mingw-w64-public -- Sébastien Villemot CEPREMAP — http://www.cepremap.ens.fr Dynare project — http://www.dynare.org Phone: +33 1 40 77 49 90 PGP Key: 0xA6C029B9D06B2913D71C105EBE37E801FB6EFF8B (http://pgp.mit.edu/)
#include <mex.h>
void
mexFunction(int nlhs, mxArray *plhs[],
int nrhs, const mxArray *prhs[])
{
// The next statement throws an exception...
mexErrMsgTxt("error message");
// ...the next statement is therefore never reached
mexPrintf("information message");
}
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