[Mageia-dev] rpmrc [5221] build with -fPIC on x86_64 too (pok, mdv)

Thu Jan 10 02:54:33 CET 2013

26.09.2012 22:57, Thierry Vignaud kirjoitti:
+> On 26 September 2012 20:30, Anssi Hannula <anssi at mageia.org> wrote:
+>>> Author
+>>>     tv
+>>
+>>>       Log Message
+>>>
+>>> build with -fPIC on x86_64 too (pok, mdv)
+>>
+>> Why?
+> 
+> "-fPIC should already be used on x86_64 or you'll get sooner or later in
+>  troubles (for instance when linking libs). I think that any sane build
+>  script should already default to -fPIC on x86_64 but some other weird
+>  build script may not." (rtp)
+
+I have to strongly disagree with this.
+
+- This hides problems in build scripts. Shared libraries should normally
+  be linked with -fPIC on *all* architectures. Not doing this causes
+  some issues, like the library to actually become unshareable across
+  different processes. Since these are allowed in iX86 but not on
+  x86_64, building all objects on x86_64 with -fPIC will hide any
+  "missing -fPIC from build script" issues.
+  Note that there can't be very many problematic failing packages, since
+  we and mdv have managed this far without it.
+
+- It is not needed except on shared libraries, and will cause a small
+  performance penalty (due to one less register being available when
+  using relative addressing). (AFAIU it is negligible, but still..)
+
+- Other major distros (not counting MDV) do not do this
+
+-- 
+Anssi Hannula
+