| Message ID | CAGWvnym5=2BAUnzQSJtapmiERp8SyW+CXknuBYe5RCUTpvq2PA@mail.gmail.com |
|---|---|
| State | New |
| Headers | show |
Index: libtool.m4 =================================================================== --- libtool.m4 (revision 190521) +++ libtool.m4 (working copy) @@ -3580,6 +3580,7 @@ # AIX 5 now supports IA64 processor _LT_TAGVAR(lt_prog_compiler_static, $1)='-Bstatic' fi + _LT_TAGVAR(lt_prog_compiler_pic, $1)='-fPIC' ;; amigaos*) @@ -3891,6 +3892,7 @@ # AIX 5 now supports IA64 processor _LT_TAGVAR(lt_prog_compiler_static, $1)='-Bstatic' fi + _LT_TAGVAR(lt_prog_compiler_pic, $1)='-fPIC' ;; amigaos*)
The GCC -fpic/-fPIC option has evolved to mean code generation for a shared library and changes the optimization behavior of the compiler. Code for AIX PowerPC always is PIC, but the optimization behavior is affecting AIX. libtool exports all global symbols on AIX while GCC binds_local_p() determines that some function calls are local, causing GCC to emit the local (non-external) form of function calls, which generates AIX linker warnings. The IBM XL compiler defaults to the equivalent of -fpic. GCC could try to match that, but it requires working around other GCC bootstrap problems and continually chasing compatibility. The other option is to assume that developers using GCC to build shared libraries either are using libtool or copying FOSS Makefiles designed for GNU/Linux or expecting GNU/Linux compatibility. The following patch starts to implement the latter by adding "-fPIC" to the compiler command line options when building objects for a shared library. Because this places control in the hands of the user with a command line option and matches GNU/Linux, this seems better than playing with defaults and fighting GCC semantics for building shared libraries. I also will post this patch upstream to Libtool. Comments? Thanks, David * libtool.m4 (_LT_COMPILER_PIC): Add -fPIC to GCC and GXX for AIX. * configure: Regenerate.