"relocation R_X86_64_32S against " linking Error

Question

I'm Trying to Link a static Library to a shared library , I'm Getting the Following error

/usr/bin/ld: ../../../libraries/log4cplus/liblog4cplus.a(fileappender.o): relocation R_X86_64_32S against `a local symbol' can not be used when making a shared object; recompile with -fPIC
../../../libraries/log4cplus/liblog4cplus.a: could not read symbols: Bad value
collect2: ld returned 1 exit status

But this worked on a 32bit machine without any such error. I tried adding The -fPIC flags manually to the Makefile that too didn't solve the problem

I tried the -whole-archive flag as suggested here but with no success.

 
/usr/bin/ld: ../../../libraries/log4cplus/liblog4cplus.a(appenderattachableimpl.o): relocation R_X86_64_32S against `vtable for log4cplus::spi::AppenderAttachable' can not be used when making a shared object; recompile with -fPIC
../../../libraries/log4cplus/liblog4cplus.a(appenderattachableimpl.o): could not read symbols: Bad value
collect2: ld returned 1 exit status

Creation of liblog4cplus.a:

1. unzip log4cplus-1.1.0.zip
2. ./configure --enable-static=yes --enable-threads=yes
3. vi Makefile and added -fPIC to CXXFLAGS and CFLAGS
4. make

Then for Compiling my shared library:

1. g++ -frtti -w -c -fPIC -I"Include_Directory" myfile.cpp
2. g++ -shared -fPIC -frtti -I"Include_Directory" -o mysofile.so myfile.o -Wl,--whole-archive "../../../libraries/log4cplus/liblog4cplus.a" -Wl,--no-whole-archive -ldl

Answer 1

Assuming you are generating a shared library, most probably what happens is that the variant of liblog4cplus.a you are using wasn't compiled with -fPIC. In linux, you can confirm this by extracting the object files from the static library and checking their relocations:

ar -x liblog4cplus.a  
readelf --relocs fileappender.o | egrep '(GOT|PLT|JU?MP_SLOT)'

If the output is empty, then the static library is not position-independent and cannot be used to generate a shared object.

Since the static library contains object code which was already compiled, providing the -fPIC flag won't help.

You need to get ahold of a version of liblog4cplus.a compiled with -fPIC and use that one instead.

Answer 2

Add -fPIC at the end of CMAKE_CXX_FLAGS and CMAKE_C_FLAG

Example:

set( CMAKE_CXX_FLAGS  "${CMAKE_CXX_FLAGS} -Wall --std=c++11 -O3 -fPIC" )
set( CMAKE_C_FLAGS  "${CMAKE_C_FLAGS} -Wall -O3 -fPIC" )

This solved my issue.

Answer 3

Relocation R_X86_64_PC32 against undefined symbol , usually happens when LDFLAGS are set with hardening and CFLAGS not .
Maybe just user error:
If you are using -specs=/usr/lib/rpm/redhat/redhat-hardened-ld at link time, you also need to use -specs=/usr/lib/rpm/redhat/redhat-hardened-cc1 at compile time, and as you are compiling and linking at the same time, you need either both, or drop the -specs=/usr/lib/rpm/redhat/redhat-hardened-ld . Common fixes :
https://bugzilla.redhat.com/show_bug.cgi?id=1304277#c3
https://github.com/rpmfusion/lxdream/blob/master/lxdream-0.9.1-implicit.patch