Hi Waldemar,
I see a number of buildroot build issues with the post-unification uclibc-ng versions (1.0.18 and 1.0.19) related to dl_iterate_phdr used in static builds. E.g.:
xtensa | autossh-1.4e | http://autobuild.buildroot.net/results/96807eda8a4b5a25225a82d7dd2b352b84fc3ddf xtensa | berkeleydb-5.3.28 | http://autobuild.buildroot.net/results/886aecbbd664d11383c11c6cd9434a52f9c82b46 xtensa | dvblast-3.0 | http://autobuild.buildroot.net/results/29ad877562d27896e3d68c06b8c1e3970750b51a
In fact the toolchain cannot produce static executable image unless extra -lc is given to the linker.
The failure looks like this:
xtensa-buildroot-linux-uclibc-gcc -D_LARGEFILE_SOURCE -D_LARGEFILE64_SOURCE -D_FILE_OFFSET_BITS=64 -o autossh autossh.o -lnsl xtensa-buildroot-linux-uclibc/5.4.0/libgcc.a(unwind-dw2-fde-dip.o): In function `__gthread_mutex_lock': xtensa-buildroot-linux-uclibc/libgcc/./gthr-default.h:748: undefined reference to `dl_iterate_phdr'
and is caused by the reference to dl_iterate_phdr from the DWARF unwinder in the libgcc. The linker command line parameters are the following (irrelevant paths stripped):
-o autossh crt1.o crti.o crtbegin.o autossh.o -lnsl -lgcc -lc -lgcc crtend.o crtn.o
The chain of dependencies is the following:
usr/xtensa-buildroot-linux-uclibc/sysroot/usr/lib/libc.a(init.os) is requested by usr/xtensa-buildroot-linux-uclibc/sysroot/usr/lib/libc.a(__uClibc_main.os) (__pthread_initialize_minimal)
usr/xtensa-buildroot-linux-uclibc/sysroot/usr/lib/libc.a(unwind.os) is requested by usr/xtensa-buildroot-linux-uclibc/sysroot/usr/lib/libc.a(init.os) (__GI___pthread_unwind)
usr/lib/gcc/xtensa-buildroot-linux-uclibc/5.4.0/libgcc.a(unwind-dw2-xtensa.o) is requested by usr/xtensa-buildroot-linux-uclibc/sysroot/usr/lib/libc.a(unwind.os) (_Unwind_GetCFA)
usr/lib/gcc/xtensa-buildroot-linux-uclibc/5.4.0/libgcc.a(unwind-dw2-fde-dip.o) is requested by usr/lib/gcc/xtensa-buildroot-linux-uclibc/5.4.0/libgcc.a(unwind-dw2-xtensa.o) (_Unwind_Find_FDE)
the following line only appears if extra -lc is given to the linker (so that its parameters become -o autossh crt1.o crti.o crtbegin.o autossh.o -lnsl -lgcc -lc -lgcc crtend.o crtn.o):
usr/xtensa-buildroot-linux-uclibc/sysroot/usr/lib/libc.a(dl-iterate-phdr.os) is requested by usr/lib/gcc/xtensa-buildroot-linux-uclibc/5.4.0/libgcc.a(unwind-dw2-fde-dip.o) (dl_iterate_phdr)
Prior to uclibc-1.0.18 release it used to work because a call to __pthread_initialize_minimal was being resolved to function defined in libpthread/nptl/sysdeps/generic/libc-tls.c which does not reference pthread_unwind.
Any idea how to fix this?