There is also a similar problem when using clang's compiler-rt for builtins. In that case, the internal library is /usr/lib64/clang/5.0.0/lib/linux/libclang_rt.builtins-x86_64.a.
Mesa graphics library links some libraries with -nostdlib option and relies on libtool to supply the internal libraries on the command line. Since libtool didn't find the compiler-rt builtin libarry, linking fails :( clang++ -rtlib=compiler-rt main.cpp -v Linker command line: "/usr/bin/x86_64-pc-linux-gnu-ld" --build-id --eh-frame-hdr -m elf_x86_64 -dynamic-linker /lib64/ld-linux-x86-64.so.2 -o a.out /usr/bin/../lib64/gcc/x86_64-pc-linux-gnu/4.9.x/../../../../lib64/crt1.o /usr/bin/../lib64/gcc/x86_64-pc-linux-gnu/4.9.x/../../../../lib64/crti.o /usr/bin/../lib64/gcc/x86_64-pc-linux-gnu/4.9.x/crtbegin.o -L/usr/bin/../lib64/gcc/x86_64-pc-linux-gnu/4.9.x -L/usr/bin/../lib64/gcc/x86_64-pc-linux-gnu/4.9.x/../../../../lib64 -L/usr/bin/../lib64 -L/lib/../lib64 -L/usr/lib/../lib64 -L/usr/bin/../lib64/gcc/x86_64-pc-linux-gnu/4.9.x/../../../../x86_64-pc-linux-gnu/lib -L/usr/bin/../lib64/gcc/x86_64-pc-linux-gnu/4.9.x/../../.. -L/usr/bin/../lib -L/lib -L/usr/lib /tmp/dtoul-6b0bb5.o -lc++ -lm /usr/lib64/clang/5.0.0/lib/linux/libclang_rt.builtins-x86_64.a -lgcc_eh -lc /usr/lib64/clang/5.0.0/lib/linux/libclang_rt.builtins-x86_64.a -lgcc_eh /usr/bin/../lib64/gcc/x86_64-pc-linux-gnu/4.9.x/crtend.o /usr/bin/../lib64/gcc/x86_64-pc-linux-gnu/4.9.x/../../../../lib64/crtn.o Thanks, Manoj On Wed, Jul 26, 2017 at 7:41 PM, Manoj Gupta <manojgu...@chromium.org> wrote: > Hi, > > We are trying to use clang with address sanitizer in one of the projects. > However, there are build issues because libtool's internal compiler library > detection part does not work with static libraries. > > e.g. clang++ main.cpp -fsanitize=address -v shows the use of static > library /usr/lib64/clang/5.0.0/lib/linux/libclang_rt.asan-x86_64.a > > Looking at the source code at http://git.savannah.gnu. > org/cgit/libtool.git/tree/m4/libtool.m4#n7556 , libtool does not handle > use of static libraries. > > > dnl Parse the compiler output and extract the necessary > dnl objects, libraries and library flags. > if AC_TRY_EVAL(ac_compile); then > # Parse the compiler output and extract the necessary > # objects, libraries and library flags. > > # Sentinel used to keep track of whether or not we are before > # the conftest object file. > pre_test_object_deps_done=no > > for p in `eval "$output_verbose_link_cmd"`; do > case $prev$p in > > for p in `eval "$output_verbose_link_cmd"`; do > case $prev$p in > > -L* | -R* | -l*) // Adding *.a here should handle static library > > > Is it possible for libtool to handle this case? > > Linker command line (from the above clang invocation): > > /usr/bin/x86_64-pc-linux-gnu-ld" --build-id --eh-frame-hdr -m elf_x86_64 > -dynamic-linker /lib64/ld-linux-x86-64.so.2 -o a.out > /usr/bin/../lib64/gcc/x86_64-pc-linux-gnu/4.9.x/../../../../lib64/crt1.o > /usr/bin/../lib64/gcc/x86_64-pc-linux-gnu/4.9.x/../../../../lib64/crti.o > /usr/bin/../lib64/gcc/x86_64-pc-linux-gnu/4.9.x/crtbegin.o > -L/usr/bin/../lib64/gcc/x86_64-pc-linux-gnu/4.9.x > -L/usr/bin/../lib64/gcc/x86_64-pc-linux-gnu/4.9.x/../../../../lib64 > -L/usr/bin/../lib64 -L/lib/../lib64 -L/usr/lib/../lib64 > -L/usr/bin/../lib64/gcc/x86_64-pc-linux-gnu/4.9.x/../../../../x86_64-pc-linux-gnu/lib > -L/usr/bin/../lib64/gcc/x86_64-pc-linux-gnu/4.9.x/../../.. > -L/usr/bin/../lib -L/lib -L/usr/lib -whole-archive > /usr/lib64/clang/5.0.0/lib/linux/libclang_rt.asan-x86_64.a > -no-whole-archive > --dynamic-list=/usr/lib64/clang/5.0.0/lib/linux/libclang_rt.asan-x86_64.a.syms > -whole-archive /usr/lib64/clang/5.0.0/lib/linux/libclang_rt.asan_cxx-x86_64.a > -no-whole-archive --dynamic-list=/usr/lib64/clang/5.0.0/lib/linux/ > libclang_rt.asan_cxx-x86_64.a.syms /tmp/main-0d221f.o -lc++ -lm > --no-as-needed -lpthread -lrt -lm -ldl -lgcc_s -lgcc -lc -lgcc_s -lgcc > /usr/bin/../lib64/gcc/x86_64-pc-linux-gnu/4.9.x/crtend.o > /usr/bin/../lib64/gcc/x86_64-pc-linux-gnu/4.9.x/../../../../lib64/crtn.o > > Thanks, > Manoj > >
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