Re: undefined functions and lazy dlopen()

[Manuel Bouyer <bouyer%antioche.eu.org@localhost>]

On Thu, Jan 23, 2014 at 04:10:01PM +0100, Manuel Bouyer wrote:
> Looks similar to:
> http://sourceware-org.1504.n7.nabble.com/MIPS-R-MIPS-GOT-DISP-interferes-with-lazy-binding-td230667.html
> 
> which triggered:
> http://gcc.gnu.org/bugzilla/show_bug.cgi?id=57260
> 
> I will try to apply the patch here (or find the commit in the sources)
> and see how it goes

I've built a (netbsd-6, as HEAD has issues) release and running it on
loongson, including kernel, with the attached patch. I didn't notice
side effects yet, and X can now load its modules (doens't work yet, but
now I can look at how to access registers :)

Any objection before I commit ?

-- 
Manuel Bouyer <bouyer%antioche.eu.org@localhost>
     NetBSD: 26 ans d'experience feront toujours la difference
--

Index: gcc/config/mips/mips.c
===================================================================
RCS file: /cvsroot/src/external/gpl3/gcc/dist/gcc/config/mips/mips.c,v
retrieving revision 1.1.1.1
diff -u -p -u -r1.1.1.1 mips.c
--- gcc/config/mips/mips.c      21 Jun 2011 01:22:34 -0000      1.1.1.1
+++ gcc/config/mips/mips.c      23 Jan 2014 16:47:01 -0000
@@ -6522,6 +6522,15 @@ mips_function_ok_for_sibcall (tree decl,
       && const_call_insn_operand (XEXP (DECL_RTL (decl), 0), VOIDmode))
     return false;
 
+   /* Sibling calls should not prevent lazy binding.  Lazy-binding stubs
+      require $gp to be valid on entry, so sibcalls can only use stubs
+      if $gp is call-clobbered.  */
+   if (decl
+       && TARGET_CALL_SAVED_GP
+       && !TARGET_ABICALLS_PIC0
+       && !targetm.binds_local_p (decl))
+     return false;
+
   /* Otherwise OK.  */
   return true;
 }