[Bug lto/53282] New: lto and visibility-inlines-hidden makes "wrongly" hidden symbols and in a way that depends on the order of the input compilation units

["vincenzo.innocente at cern dot ch" <gcc-bugzilla at gcc dot gnu dot org>]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=53282

             Bug #: 53282
           Summary: lto and visibility-inlines-hidden makes "wrongly"
                    hidden symbols and in a way that depends on the order
                    of the input compilation units
    Classification: Unclassified
           Product: gcc
           Version: 4.7.1
            Status: UNCONFIRMED
          Severity: blocker
          Priority: P3
         Component: lto
        AssignedTo: unassigned@gcc.gnu.org
        ReportedBy: vincenzo.innocente@cern.ch
            Target: x86_64-unknown-linux-gnu
             Build: gcc-4_7-branch revision 187276


Created attachment 27345
  --> http://gcc.gnu.org/bugzilla/attachment.cgi?id=27345
directory containing three (very similar) real-life file after pre-compiler
step

in the following example (not much reduced from a real-life code)
a symbol, very similar to others, is made hidden for no good reason.
Apparently it also depends on the order of the input filesâ


bzip2 -d ltobug3.tar.bz2 
tar -xf ltobug3.tar 
cd ltobug3/
c++ -fvisibility-inlines-hidden -O2 -flto -shared -fPIC -o bha.so d1.cc d2.cc
d3.cc ; nm -C bha.so | grep "makeKey" | grep -v "type"
0000000000004290 t
_ZN3edm10eventsetup15heterocontainer7makeKeyI11DummyRecordNS0_19EventSetupRecordKeyEEET0_v.local.77.4195
0000000000004750 W edm::eventsetup::EventSetupRecordKey
edm::eventsetup::heterocontainer::makeKey<Dummy2Record,
edm::eventsetup::EventSetupRecordKey>()
00000000000048a0 W edm::eventsetup::EventSetupRecordKey
edm::eventsetup::heterocontainer::makeKey<DepRecord,
edm::eventsetup::EventSetupRecordKey>()

c++ -fvisibility-inlines-hidden -O2 -flto -shared -fPIC -o bha.so d2.cc d1.cc
d3.cc ; nm -C bha.so | grep "makeKey" | grep -v "type"
00000000000048a0 W edm::eventsetup::EventSetupRecordKey
edm::eventsetup::heterocontainer::makeKey<DummyRecord,
edm::eventsetup::EventSetupRecordKey>()
0000000000004750 W edm::eventsetup::EventSetupRecordKey
edm::eventsetup::heterocontainer::makeKey<Dummy2Record,
edm::eventsetup::EventSetupRecordKey>()
00000000000049f0 W edm::eventsetup::EventSetupRecordKey
edm::eventsetup::heterocontainer::makeKey<DepRecord,
edm::eventsetup::EventSetupRecordKey>()