RE: [Vxl-maintainers] RE: [Cmake] command to build dynamic lib ch anged causing my VXL build to break

[Brad K. <bra...@ki...>]

Fred,

I just installed gcc 3.0.2 (second from most recent version) on a Sun at
Kitware.  The example below cannot duplicate your problem.  I suggest you
try installing gcc 3.0.3 in your home directory and do the build with
that.  Make sure that your LD_LIBRARY_PATH is set correctly to find the
gcc-3.0.3 version of the standard C++ library when you run the executable.

-Brad

> ############################################################################
> 
> cd /tmp
> 
> # LIBRARY FILE 1
> 
> cat<<EOF >| file1.cxx
> // dropping this include fixes the problem
> #include <iostream>
> EOF
> 
> c++ -fPIC -c file1.cxx -o file1.o
> 
> # LIBRARY FILE 2
> 
> cat<<EOF >| file2.cxx
> #include <vector.h>
> // dropping this expression fixes the problem
> namespace {
>   void tic(int nargs) {
>     vector<bool> done_once(nargs, false);
>   }
> }
> EOF
> 
> # dropping -O2 here fixes problem
> c++ -O2 -fPIC -c file2.cxx -o file2.o
> 
> # MAIN
> 
> cat<<EOF >| foo.cxx
> int main() { return 0; }
> EOF
> 
> c++ -c foo.cxx -o foo.o
> 
> # BUILD LIBRARY
> 
> # with this option there is no bus error
> OPT="-Wl,-G"
> # with this option there is no bus error
> OPT="-shared"
> # with this option the exec will produce a bus error
> OPT="-shared -nostdlib"
> 
> # build library with only two objects
> # dropping either object fixes the problem
> c++ $OPT -O2 -fPIC -o /tmp/libbar.so file1.o file2.o
> 
> # LINK
> 
> c++ foo.o -L/tmp -lbar -Wl,-R,/tmp: -o foo
> 
> # RUN
> 
> # bus error will occur here if "-shared -nostdlib" was used
> ./foo
> 
> ############################################################################