[Bug lto/53572] Some public symbols don't get to serialized LTO

[rguenth at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=53572

Richard Guenther <rguenth at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|UNCONFIRMED                 |NEW
   Last reconfirmed|                            |2012-06-04
                 CC|                            |hjl at gcc dot gnu.org
            Version|unknown                     |4.7.1
     Ever Confirmed|0                           |1

--- Comment #1 from Richard Guenther <rguenth at gcc dot gnu.org> 2012-06-04 12:53:16 UTC ---
Confirmed.  I see the resolution file

1
main.o 6
252 65004255f21c98f6 PREVAILING_DEF main
263 65004255f21c98f6 RESOLVED_EXEC _ZdlPv
270 65004255f21c98f6 RESOLVED_EXEC _Z1fv
202 65004255f21c98f6 PREVAILING_DEF _ZTI1A
225 65004255f21c98f6 PREVAILING_DEF _ZTS1A
213 65004255f21c98f6 RESOLVED_EXEC _ZTVN10__cxxabiv117__class_type_infoE

But the error message

`_ZTI1A' referenced in section `.rodata._ZTV1A[_ZTV1A]' of lib.a(lib.o):
defined in discarded section `.gnu.linkonce.t._ZTI1A' of main.o (symbol from
plugin)
collect2: error: ld returned 1 exit status

suggests this is a linker bug?

Either LTO decides to drop _ZTI1A from main.o - which it can - then the linker
needs to re-scan the archives and resolve the symbol to the archive provided
one:

> nm lib.o 
0000000000000000 t _GLOBAL__sub_I_a
0000000000000000 T _Z1fv
0000000000000000 W _ZN1AD0Ev
0000000000000000 W _ZN1AD1Ev
0000000000000000 W _ZN1AD2Ev
0000000000000000 n _ZN1AD5Ev
0000000000000000 V _ZTI1A
0000000000000000 V _ZTS1A
0000000000000000 V _ZTV1A
                 U _ZTVN10__cxxabiv117__class_type_infoE
                 U _ZdlPv
                 U __cxa_atexit
                 U __dso_handle
0000000000000000 B a

Thus, can you file a binutils bug?