compile and get errors as undefined reference to `_Ux86_64_getcontext'

[liudong1983]

1. download the seastar latest version

2. we compile to get a libseastar.a file
   ./configure.py --with libseastar.a --mode release
   ninja-build
   then, we can get a libseastar.a file

3. call seastar api ,then compile and link, we get errors
   build64_release/thirdparty/seastar/libseastar.a(reactor.o): In function backtrace<current_backtrace()::<lambda(uintptr_t)> >': /data/ckv_plus_proj/trunk/thirdparty/seastar/./util/backtrace.hh:33: undefined reference to _Ux86_64_getcontext'
   /data/ckv_plus_proj/trunk/thirdparty/seastar/./util/backtrace.hh:38: undefined reference to _ULx86_64_init_local' /data/ckv_plus_proj/trunk/thirdparty/seastar/./util/backtrace.hh:42: undefined reference to _ULx86_64_step'
   /data/ckv_plus_proj/trunk/thirdparty/seastar/./util/backtrace.hh:44: undefined reference to `_ULx86_64_get_reg'

what's the problem?don't libunwind pack to libseastar.a?

[gleb-cloudius]

On Wed, Apr 12, 2017 at 05:08:15AM -0700, 刘栋 wrote: 1. download the seastar latest version 2. we compile to get a libseastar.a file ./configure.py --with libseastar.a --mode release ninja-build then, we can get a libseastar.a file 3. call seastar api ,then compile and link, we get errors build64_release/thirdparty/seastar/libseastar.a(reactor.o): In function `backtrace<current_backtrace()::<lambda(uintptr_t)> >': /data/ckv_plus_proj/trunk/thirdparty/seastar/./util/backtrace.hh:33: undefined reference to `_Ux86_64_getcontext' /data/ckv_plus_proj/trunk/thirdparty/seastar/./util/backtrace.hh:38: undefined reference to `_ULx86_64_init_local' /data/ckv_plus_proj/trunk/thirdparty/seastar/./util/backtrace.hh:42: undefined reference to `_ULx86_64_step' /data/ckv_plus_proj/trunk/thirdparty/seastar/./util/backtrace.hh:44: undefined reference to `_ULx86_64_get_reg' what's the problem?

Do you have libunwind-devel installed?

…

-- Gleb.

[liudong1983]

@gleb-cloudius

1. libunwind library file is installed in /usr/local/lib directory

root@fea23:/data/ckv_plus_proj/trunk/thirdparty/seastar# ls -al /usr/local/lib/unwind
-rw-r--r-- 1 root root 235618 Apr 13 02:28 /usr/local/lib/libunwind-coredump.a
-rwxr-xr-x 1 root root 997 Apr 13 02:28 /usr/local/lib/libunwind-coredump.la
lrwxrwxrwx 1 root root 27 Apr 13 02:28 /usr/local/lib/libunwind-coredump.so -> libunwind-coredump.so.0.0.0
lrwxrwxrwx 1 root root 27 Apr 13 02:28 /usr/local/lib/libunwind-coredump.so.0 -> libunwind-coredump.so.0.0.0
-rwxr-xr-x 1 root root 103088 Apr 13 02:28 /usr/local/lib/libunwind-coredump.so.0.0.0
lrwxrwxrwx 1 root root 18 Apr 13 02:28 /usr/local/lib/libunwind-generic.a -> libunwind-x86_64.a
lrwxrwxrwx 1 root root 19 Apr 13 02:28 /usr/local/lib/libunwind-generic.so -> libunwind-x86_64.so
-rw-r--r-- 1 root root 191344 Apr 13 02:28 /usr/local/lib/libunwind-ptrace.a
-rwxr-xr-x 1 root root 983 Apr 13 02:28 /usr/local/lib/libunwind-ptrace.la
lrwxrwxrwx 1 root root 25 Apr 13 02:28 /usr/local/lib/libunwind-ptrace.so -> libunwind-ptrace.so.0.0.0
lrwxrwxrwx 1 root root 25 Apr 13 02:28 /usr/local/lib/libunwind-ptrace.so.0 -> libunwind-ptrace.so.0.0.0
-rwxr-xr-x 1 root root 80728 Apr 13 02:28 /usr/local/lib/libunwind-ptrace.so.0.0.0
-rw-r--r-- 1 root root 35316 Apr 13 02:28 /usr/local/lib/libunwind-setjmp.a
-rwxr-xr-x 1 root root 1058 Apr 13 02:28 /usr/local/lib/libunwind-setjmp.la
lrwxrwxrwx 1 root root 25 Apr 13 02:28 /usr/local/lib/libunwind-setjmp.so -> libunwind-setjmp.so.0.0.0
lrwxrwxrwx 1 root root 25 Apr 13 02:28 /usr/local/lib/libunwind-setjmp.so.0 -> libunwind-setjmp.so.0.0.0
-rwxr-xr-x 1 root root 21704 Apr 13 02:28 /usr/local/lib/libunwind-setjmp.so.0.0.0
-rw-r--r-- 1 root root 1099604 Apr 13 02:28 /usr/local/lib/libunwind-x86_64.a
-rwxr-xr-x 1 root root 1023 Apr 13 02:28 /usr/local/lib/libunwind-x86_64.la
lrwxrwxrwx 1 root root 25 Apr 13 02:28 /usr/local/lib/libunwind-x86_64.so -> libunwind-x86_64.so.8.0.1
lrwxrwxrwx 1 root root 25 Apr 13 02:28 /usr/local/lib/libunwind-x86_64.so.8 -> libunwind-x86_64.so.8.0.1
-rwxr-xr-x 1 root root 571328 Apr 13 02:28 /usr/local/lib/libunwind-x86_64.so.8.0.1
-rw-r--r-- 1 root root 829428 Apr 13 02:28 /usr/local/lib/libunwind.a
-rwxr-xr-x 1 root root 946 Apr 13 02:28 /usr/local/lib/libunwind.la
lrwxrwxrwx 1 root root 18 Apr 13 02:28 /usr/local/lib/libunwind.so -> libunwind.so.8.0.1
lrwxrwxrwx 1 root root 18 Apr 13 02:28 /usr/local/lib/libunwind.so.8 -> libunwind.so.8.0.1
-rwxr-xr-x 1 root root 374112 Apr 13 02:28 /usr/local/lib/libunwind.so.8.0.1

root@fea23:/data/ckv_plus_proj/trunk/thirdparty/seastar# nm /usr/local/lib/libunwind.a|grep _Ux86_64_getcontext
66: U _Ux86_64_getcontext
67: U _Ux86_64_getcontext_trace
266:0000000000000000 T _Ux86_64_getcontext
267:0000000000000071 T _Ux86_64_getcontext_trace

2. i check the build.ninja file

configure_args = --mode release --with libseastar.a --ldflags '-L /usr/local/lib -lunwind'
builddir = build
cxx = g++

cxxflags = -std=gnu++1y -g -Wall -Werror -Wno-error=deprecated-declarations -fvisibility=hidden -pthread -I. -U_FORTIFY_SOURCE -Ifmt -DBOOST_TEST_DYN_LINK -Wno-overloaded-virtual -DFMT_HEADER_ONLY -DHAVE_XEN -DHAVE_HWLOC -DHAVE_NUMA -DHAVE_LZ4_COMPRESS_DEFAULT
ldflags = -g -Wl,--no-as-needed -fvisibility=hidden -pthread -L /usr/local/lib -lunwind
libs = -laio -lboost_program_options -lboost_system -lboost_filesystem -lstdc++ -lm -lboost_thread -lcryptopp -lrt -lgnutls -lgnutlsxx -llz4 -lprotobuf -ldl -lgcc_s -lunwind -lxenstore -lhwloc -lnuma -lpciaccess -lxml2 -lz -lcares-seastar

reactor.o should include the unwind library

3. what's the difference with the libunwind and libunwind-devel? i install libunwind by download libunwind source code, then configure && make && make install
   the company's develop machine can't connect to internet and github, so it's difficult to find all the dependency.

[gleb-cloudius]

what's the difference with the libunwind and libunwind-devel?

libunwind-devel install things you need for development: headers, manuals, static and unversioned dynamic libraries (.so as opposite to .so.VERSION).

…

-- Gleb.

[liudong1983]

i have solved the problem.
add -L/usr/local/lib -lunwind to ldflags