Ok. Thanks. I don't really understand ALL technical details in a found link. Could you explain this briefly (or refer me to other sources). Thank you, Alexey -----Original Message----- From: Andrew Haley [mailto:aph@xxxxxxxxxx] Sent: Wednesday, December 16, 2009 4:58 PM To: Alexey Skidanov Cc: gcc-help@xxxxxxxxxxx Subject: Re: Position Independent Code usage on x86-64 Alexey Skidanov wrote: > We ported our code to 64 bit (CentOS 5.2 64 bit). We have some static > library that linked with some shared library. In 32 bit version, the > shared library was successfully created. Trying to create it in with 64 > bit version compiler, we get the error: > > /usr/bin/ld: .//libstatic.a(static.o): relocation R_X86_64_32 against > `__gxx_personality_v0' can not be used when making a shared object; > recompile with -fPIC > .//libstatic.a: could not read symbols: Bad value > collect2: ld returned 1 exit status > > We also found that if static library is linked with shared library then > it should be compiled with -fPIC option. But if the static library is > linked with ELF executable it shouldn't. It can be, but it's not absolutely nmecessary. > The questions are: > 1. Does it make sense that we need to know about static library exact > usage? > 2. Is there an option of gcc that "generate" backward compatible (with > 32 bit version) compilation/linking process? No. You best option is always to link with the -fPIC option all code that may go into shared libraries. It won't hurt 32-bit libraries, and it may save memory. > We found some explanation here > http://www.technovelty.org/code/c/amd64-pic.html That seems right. What more do you need? Andrew.
