[Bug lto/50687] New: Missing symbols with -flto -fvisibility=hidden on 4.6.x but not on 4.7.0

[giulio.eulisse at cern dot ch]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=50687

             Bug #: 50687
           Summary: Missing symbols with -flto -fvisibility=hidden on
                    4.6.x but not on 4.7.0
    Classification: Unclassified
           Product: gcc
           Version: 4.6.2
            Status: UNCONFIRMED
          Severity: blocker
          Priority: P3
         Component: lto
        AssignedTo: unassigned@gcc.gnu.org
        ReportedBy: giulio.eulisse@cern.ch


There seems to be a bug (or least a different behavior) when compiling: 

  cat >test.cc <<-EOF
  struct bar {
     static void * foo();
     virtual void * getFoo() const { return bar::foo();}
  };
  EOF

with:

  c++ -fPIC -shared -flto -fvisibility=hidden test.cc

using gcc 4.6.x (both 4.6.1 release and this week 4.6.2 snapshot) compared to
gcc
4.7.0 (20111001 snapshot).

In the case of gcc 4.6.x I get a missing symbol:

  % nm a.out | grep U
  U _ZN3bar3fooEv  

while with 4.7.x I don't get it anymore (which is what I would expect).

Dropping -flto fixes the behavior also for 4.6.x.