PATCH] PR target/65612: Multiversioning doesn't work with DSO nor PIE

[Szabolcs Nagy]

On 11/05/15 14:05, Jakub Jelinek wrote:
> On Mon, May 11, 2015 at 01:39:17PM +0100, Szabolcs Nagy wrote:
>> fyi, musl loader loads libstdc++ just fine because it has no
> 
> But will it load any shared library that uses any of the 26 (if I count well
> on x86_64) @ symbols from libstdc++.so.6?

i looked, but all of those symbols have @@ variant too
so at least the libraries would load with musl.

>> musl may end up supporting @version but that's an independent
>> quest.
> 
> It is not independent.  If musl claims to support symbol versioning, it
> should support it properly, if not, then supposedly gcc configured for musl
> can't be compatible with gcc configured for other linux C libraries, and
> should force symbol versioning off.

ok, but the current solution does not make that easy:
configuring gcc with

  --disable-gnu-indirect-function --disable-symvers

has no effect on libgcc_s.so.1 on linux.

(i can try to create a patch that removes the new
-DUSE_ELF_SYMVER from the libgcc cflags for musl, but that
seems a worse solution than the weak alias one).

(note that previously a simple spec file was enough to use an
existing gcc on linux to build things against musl...
this didnt work for c++ code that used libstdc++ headers, but
now it also fails for any build using -lgcc_s).