On Fri, 18 Dec 2015, Paul Smith wrote:
Hi all. I normally build my code with -static-libgcc and -static -libstdc++, so I don't need to worry about compiler and stdc++ library versions when I copy programs around. I don't link with any other (non -locally-built) C++ code so it works for me. I'm using GNU/Linux with a version of GCC 5.3.0 / binutils 2.25.1 that I built myself locally, and it works in all other respects. However today I decided to try to add -fsanitize=undefined to my compile and link lines, and this caused my link to fail with errors such as: /tools/cc/generic/bin/../lib/gcc/x86_64-generic-linux -gnu/5.3.0/../../../../x86_64-generic-linux -gnu/lib/../lib64/libubsan.a(ubsan_type_hash.o): In function `findBaseAtOffset(__cxxabiv1::__class_type_info const*, long)': (.text+0x3c): undefined reference to `__dynamic_cast' If I remove the -static-libstdc++ flag then it links fine. I have used other sanitizers like ASAN for a long time, with static libstdc++, with no problems. Is it just the case that UBSAN cannot work with static libstdc++? Or is my local installation of GCC 5.3 deficient somehow? Or is this a bug that I should report?
I guess you could call it a bug that -lubsan ends up after -lstdc++ in the linker command. Please add -v to your command line and include what it prints in your bug report (assuming there isn't already one, I didn't look).
-- Marc Glisse
