[Bug target/19520] protected function pointer doesn't work right

[hjl.tools at gmail dot com]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=19520

--- Comment #29 from H.J. Lu <hjl.tools at gmail dot com> 2012-01-19 18:29:39 UTC ---
(In reply to comment #28)
> Final conclusion:  We need to resolve to the executables PLT consistently,
> even from inside the shared object where the function binds locally.  This
> is because of references to the function from the executables .rodata section
> which we can't relocate (and thus have to point to the executables PLT entry).
> 
> Thus, this is a GCC target bug.
> 
> __attribute__((visibility("protected"))) void * foo () { return foo; }
> 
> needs to return the address of foo via a load from the GOT.  HJs patch
> isn't correct as this is really a target ABI choice (another ABI may
> choose to resolve all references to the functions start address with

It only applies when we take an address of a protected function.
Branch to a protected function doesn't need to go through PLT.