Linking problem with lld

Sun Mar 3 14:22:01 UTC 2019

On 3-3-2019 14:45, Willem Jan Withagen wrote:
> On 3-3-2019 13:34, Tĳl Coosemans wrote:
>> On Sun, 3 Mar 2019 12:50:03 +0100 Willem Jan Withagen <wjw at digiware.nl>
>> wrote:
>>> On 2-3-2019 18:35, Tĳl Coosemans wrote:
>>>> On Sat, 2 Mar 2019 17:49:25 +0100 Willem Jan Withagen 
>>>> <wjw at digiware.nl>
>>>> wrote:
>>>>> On 2-3-2019 16:21, Tĳl Coosemans wrote:
>>>>>> On Sat, 2 Mar 2019 14:21:57 +0100 Willem Jan Withagen 
>>>>>> <wjw at digiware.nl>
>>>>>> wrote:
>>>>>>> Now if I look in librados.so for rados_create that gives:
>>>>>>> ====
>>>>>>>     > objdump -t librados.so.2.0.0 | grep rados_create
>>>>>> You want to look at dynamic symbols so "objdump -T".
>>>>> Right, that list is empty.
>>>>>
>>>>> So I'm wondering what I can do to get them in that list.
>>>> Try the command that creates librados.so.2.0.0 without the
>>>> --version-script argument.
>>> Right, When I see the output, I know I tried that before. But then the
>>> versioning goes
>>> wrong, I think...
>>> Might need to rewrite the map-file?
>>>
>>> --WjW
>>>
>>> [ 43%] Linking CXX shared library ../../lib/librados.so
>>> cd /home/jenkins/workspace/ceph-master/build/src/librados &&
>>> /usr/local/bin/cmake -E cmake_link_script
>>> CMakeFiles/librados.dir/link.txt --verbose=1
>>> ccache /usr/bin/c++ -fPIC  -Wall -Wtype-limits -Wignored-qualifiers
>>> -Winit-self -Wpointer-arith -Werror=format-security 
>>> -fno-strict-aliasing
>>> -fsigned-char -Wno-unknown-pragmas -Wno-unused-function
>>> -Wno-unused-local-typedef -Wno-varargs -Wno-gnu-designator
>>> -Wno-missing-braces -Wno-parentheses -Wno-deprecated-register
>>> -ftemplate-depth-1024 -Wnon-virtual-dtor -Wno-unknown-pragmas
>>> -Wno-ignored-qualifiers -Wno-inconsistent-missing-override
>>> -Wno-mismatched-tags -Wno-unused-private-field
>>> -Wno-address-of-packed-member -DCEPH_DEBUG_MUTEX
>>> -fdiagnostics-color=auto -fno-builtin-malloc -fno-builtin-calloc
>>> -fno-builtin-realloc -fno-builtin-free  -O0 -g -fvisibility=default
>>> -Wl,--exclude-libs,ALL -shared -Wl,-soname,librados.so.2 -o
>>> ../../lib/librados.so.2.0.0 CMakeFiles/librados.dir/librados_c.cc.o
>>> CMakeFiles/librados.dir/librados_cxx.cc.o
>>> ../common/CMakeFiles/common_buffer_obj.dir/buffer.cc.o -L/usr/local/lib
>>> -Wl,-rpath,/usr/local/lib:/home/jenkins/workspace/ceph-master/build/lib:/usr/local/lib/nss: 
>>>
>>> ../../lib/liblibrados_impl.a ../../lib/libosdc.a
>>> ../../lib/libceph-common.so.0 ../../lib/libcls_lock_client.a
>>> /usr/local/lib/nss/libssl3.so /usr/local/lib/nss/libsmime3.so
>>> /usr/local/lib/nss/libnss3.so /usr/local/lib/nss/libnssutil3.so
>>> /usr/local/lib/libplds4.so /usr/local/lib/libplc4.so
>>> /usr/local/lib/libnspr4.so /usr/local/lib/libcrypto.so -lrt
>>> ../../lib/libjson_spirit.a ../../lib/libcommon_utf8.a
>>> ../../lib/liberasure_code.a ../../lib/libcrc32.a ../../lib/libarch.a
>>> /usr/local/lib/libboost_thread.so /usr/local/lib/libboost_chrono.so
>>> /usr/local/lib/libboost_atomic.so /usr/local/lib/libboost_random.so
>>> /usr/local/lib/libboost_system.so
>>> /usr/local/lib/libboost_program_options.so
>>> /usr/local/lib/libboost_date_time.so
>>> /usr/local/lib/libboost_iostreams.so /usr/local/lib/libboost_regex.so
>>> /usr/lib/libexecinfo.so /usr/local/lib/nss/libssl3.so
>>> /usr/local/lib/nss/libsmime3.so /usr/local/lib/nss/libnss3.so
>>> /usr/local/lib/nss/libnssutil3.so /usr/local/lib/libplds4.so
>>> /usr/local/lib/libplc4.so /usr/local/lib/libnspr4.so -lpthread
>>> ld: error: CMakeFiles/librados.dir/librados_c.cc.o: symbol
>>> rados_aio_append@@ has undefined version
>>> ld: error: CMakeFiles/librados.dir/librados_c.cc.o: symbol
>>> rados_aio_cancel@@ has undefined version
>>> ld: error: CMakeFiles/librados.dir/librados_c.cc.o: symbol
>>> rados_aio_cmpext@@ has undefined version
>>> ld: error: CMakeFiles/librados.dir/librados_c.cc.o: symbol
>>> rados_aio_create_completion@@ has undefined version
>>> ld: error: CMakeFiles/librados.dir/librados_c.cc.o: symbol
>>> rados_aio_exec@@ has undefined version
>>> ld: error: CMakeFiles/librados.dir/librados_c.cc.o: symbol
>>> rados_aio_flush@@ has undefined version
>>> ld: error: CMakeFiles/librados.dir/librados_c.cc.o: symbol
>>> rados_aio_flush_async@@ has undefined version
>>> ld: error: CMakeFiles/librados.dir/librados_c.cc.o: symbol
>>> rados_aio_get_return_value@@ has undefined version
>>> ld: error: CMakeFiles/librados.dir/librados_c.cc.o: symbol
>>> rados_aio_get_version@@ has undefined version
>>> ld: error: CMakeFiles/librados.dir/librados_c.cc.o: symbol
>>> rados_aio_getxattr@@ has undefined version
>>> ld: error: CMakeFiles/librados.dir/librados_c.cc.o: symbol
>>> rados_aio_getxattrs@@ has undefined version
>>> ld: error: CMakeFiles/librados.dir/librados_c.cc.o: symbol
>>> rados_aio_ioctx_selfmanaged_snap_create@@ has undefined version
>>> ld: error: CMakeFiles/librados.dir/librados_c.cc.o: symbol
>>> rados_aio_ioctx_selfmanaged_snap_remove@@ has undefined version
>>> ld: error: CMakeFiles/librados.dir/librados_c.cc.o: symbol
>>> rados_aio_is_complete@@ has undefined version
>>> ld: error: CMakeFiles/librados.dir/librados_c.cc.o: symbol
>>> rados_aio_is_complete_and_cb@@ has undefined version
>>> ld: error: CMakeFiles/librados.dir/librados_c.cc.o: symbol
>>> rados_aio_is_safe@@ has undefined version
>>> ld: error: CMakeFiles/librados.dir/librados_c.cc.o: symbol
>>> rados_aio_is_safe_and_cb@@ has undefined version
>>> ld: error: CMakeFiles/librados.dir/librados_c.cc.o: symbol
>>> rados_aio_notify@@ has undefined version
>>> ld: error: CMakeFiles/librados.dir/librados_c.cc.o: symbol
>>> rados_aio_read@@ has undefined version
>>> ld: error: CMakeFiles/librados.dir/librados_c.cc.o: symbol
>>> rados_aio_read_op_operate@@ has undefined version
>>> ld: error: too many errors emitted, stopping now (use -error-limit=0 to
>>> see all errors)
>>> c++: error: linker command failed with exit code 1 (use -v to see
>>> invocation)
>> You could start with a simple version map:
>>
>> LIBRADOS_14.2.0 {
>>           global: *;
>> };
>>
>> If symbols are visible in objdump -T output with this, you can then
>> expand the map bit by bit and see at what point it goes wrong.
>>
>> My guess is the "local: *" in the beginning is matching everything so
>> nothing remains visible.
> I agree with that, but up till now all attempts I made failed....
> So more trial and error ;-)
>> See also https://bugs.llvm.org/show_bug.cgi?id=40176
> I also "used"
>   https://sourceware.org/binutils/docs/ld/VERSION.html
> which in itself explains some things, but the actual detailed 
> functioning has to be infered

First success.
I used this map, but also needed to fix a .symver:
====
  #define LIBRADOS_C_API_BASE_DEFAULT(fn)       \
-  asm(".symver _" #fn ", " #fn "@@")
+  asm(".symver _" #fn ", " #fn "@")
====
That last was more or less guessed from the binutils/docs/ld page.

--WjW