[LLVMdev] GCC_4.2.0 problem

Nick Lewycky nicholas at mxc.ca
Thu Sep 28 10:51:41 PDT 2006

Chris Lattner wrote:
>>Why does llvm-gcc build its own libgcc_s.so? Would we have the same
>>problem if we tried to build FSF GCC 4.01, or is this problem LLVM-specific?
> libgcc is part of the GCC distro.  My (possibly flawed) understanding of 
> the issue is that GCC generates code that contains calls into libgcc. 
> This means that any code compiled with llvm-gcc should used llvm-gcc's 
> libgcc.  It's quite possible that the GCC build is getting confused and 
> building cc1 with the system gcc but trying to use llvm-gcc's libgcc or 
> opposite.

The problem is that the system standard libstdc++.so.6 has extern
symbols that it expects to be resolved by linking against libgcc_s. In
an FSF build, xgcc doesn't link to libstdc++.

(As an aside, most programs compiled with g++ link to libstdc++ but not
libgcc_s. I'm not clear on how that works for other programs, but not xgcc?)


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