Hi AJ. Exception support can still be turned on in C code when it's supposed to interoperate with C++ code. An example is the 64 bit division routine in libgcc - it could potentially throw a division by zero exception when called from C++ code even though the function is written in C.
-- Michael On Tue, Apr 19, 2011 at 10:38 AM, AJ ONeal <coola...@gmail.com> wrote: > What is an "exception" in C? > There is no CPP (.cpp or .cxx) code in any of these libraries. > > Interesting thing though: > cmem has a userspace and kernelspace component. > TI does really nasty stuff, like pull in .h files from the kernel and > whatnot. > I just tried again against the 2.6.38 kernel (was 2.6.36 this morning) and > there is no error. > http://lxr.free-electrons.com/ident?i=__aeabi_unwind_cpp_pr0 > Perhaps it's just something in my .config that turns that on or off in the > kernel. > AJ ONeal > > > On Mon, Apr 18, 2011 at 3:06 PM, Michael Hope <michael.h...@linaro.org> > wrote: >> >> On Tue, Apr 19, 2011 at 5:39 AM, AJ ONeal <coola...@gmail.com> wrote: >> > >> > I'm compiling an application built with TI's DVSDK 3 *[0]. >> > >> > >> > >> > >> > /home/user/ti/dvsdk/dvsdk_3_01_00_10/linuxutils_2_25_02_08/packages/ti/sdo/linuxutils/cmem/lib/cmem.a470MV(cmem.o470MV):(.ARM.exidx+0x0): >> > undefined reference to `__aeabi_unwind_cpp_pr0' >> > >> > >> > >> > arm-linux-gnueabi-gcc --version >> > arm-linux-gnueabi-gcc (Ubuntu/Linaro 4.5.2-5ubuntu2~ppa1) 4.5.2 >> > arm-linux-gnueabi-ld --version >> > GNU ld (GNU Binutils for Ubuntu) 2.21.0.20110302 >> > >> > More full output is here (but it isn't particularly helpful due to TI's >> > RTSC >> > make system's black-magic) >> > https://gist.github.com/925674 >> > FYI: the MV in cmem.a470MV stands for MontaVista. >> > This name is hard-coded somewhere even though it's not being linked >> > against >> > a MontaVista system. >> > I believe the 470 means that it should work with ARMv4 through ARMv7, >> > but >> > I'm not positive. >> > >> > My googling suggest that this is a toolchain bug and that the best way >> > around the issue is to create a file which defines the function as a >> > void >> > dummy and include it. >> > http://www.codesourcery.com/archives/arm-gnu/msg03604.html >> > http://comments.gmane.org/gmane.comp.boot-loaders.u-boot/78649 >> > >> > http://www.cs.fsu.edu/~baker/devices/lxr/http/ident?i=__aeabi_unwind_cpp_pr0 >> > >> > I have a script that I'll post shortly with instructions as to how to >> > setup >> > TI's DVSDK with Linaro >> > AJ ONeal >> > >> > [0] I'm not using the latest DVSDK version 4 because the paths and such >> > are >> > so hard-coded for the 2009q3 version of codesourcery on ubuntu 10.04 LTS >> > that I don't know where to start fixing it. >> >> Hi AJ. __aeabi_unwind_cpp_pr0 is part of the standard ARM exception >> handling code and helps in unwinding the stack frame when an exception >> occurs. This suggests that the binary cmem.a470MV can throw >> exceptions and therefore needs exception handling. >> >> I don't think this is a toolchain bug as this function is included in >> libgcc_eh.a and is normally pulled in automatically. Could you add >> '-v' to your linker flags and send through the result? >> >> -- Michael > > _______________________________________________ linaro-toolchain mailing list linaro-toolchain@lists.linaro.org http://lists.linaro.org/mailman/listinfo/linaro-toolchain
