gcc correctly devirtualizes in this case:

markus@x4 llvm_build % cat RuntimeDyld.ii
namespace std
{
inline namespace __cxx11
{
}
template <typename> struct char_traits;
template <typename> class allocator;
namespace __cxx11
{
template <typename _CharT, typename = char_traits<_CharT>,
          typename = allocator<_CharT> >
class basic_string
{
  struct _Alloc_hider
  {
    _Alloc_hider (int);
  } _M_dataplus;

public:
  basic_string (void *) : _M_dataplus (0) {}
};
}
}

namespace llvm
{
class RTDyldMemoryManager
{
public:
  void getSymbolAddressInProcess (const std::basic_string<char> &);
  virtual int
  getSymbolAddress (std::basic_string<int>)
  {
    getSymbolAddressInProcess (0);
  }
};
class A
{
  RTDyldMemoryManager *MemMgr;
  void resolveExternalSymbols ();
};
void
A::resolveExternalSymbols ()
{
  MemMgr->getSymbolAddress (0);
}
}

markus@x4 llvm_build % g++ -O2 -c -std=c++11 RuntimeDyld.ii
markus@x4 llvm_build % nm RuntimeDyld.o| grep _ZN4llvm19RTDyldMemoryManager25getSymbolAddressInProcessERKNSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEEE
                 U _ZN4llvm19RTDyldMemoryManager25getSymbolAddressInProcessERKNSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEEE

Also happens with gcc-4.9.

Hi Octoploid,

Thanks for tracking this down. I've tried to fix this dependency issue in r229343. Could you try that out and see if it fixes the issue?

Cheers,
Lang.

(In reply to comment #2)
> Thanks for tracking this down. I've tried to fix this dependency issue in
> r229343. Could you try that out and see if it fixes the issue?

Yes it does. Thanks.

same error compiling mesa with gcc 5 and llvm 3.6(rc):

/bin/sh ../../../../libtool  --tag=CXX   --mode=link g++-5  -O2  -Wall -fno-strict-aliasing -fno-builtin-memcmp  -shared -module -no-undefined -avoid-version -Wl,--gc-sections -Wl,--no-undefined -Wl,--version-script=../../../../src/gallium/targets/omx/omx.sym -L/usr/lib64  -O2  -o libomx_mesa.la -rpath /usr/lib64/bellagio libomx_mesa_la-target.lo ../../../../src/gallium/state_trackers/omx/libomxtracker.la ../../../../src/gallium/auxiliary/libgalliumvlwinsys.la ../../../../src/gallium/auxiliary/libgalliumvl.la ../../../../src/gallium/auxiliary/libgallium.la ../../../../src/util/libmesautil.la -lomxil-bellagio  -lX11-xcb -lX11 -lxcb-dri2 -lxcb  -ldrm  -lm  -lpthread -ldl ../../../../src/loader/libloader.la  ../../../../src/gallium/drivers/r600/libr600.la -ldrm_radeon  -ldrm   ../../../../src/gallium/winsys/radeon/drm/libradeonwinsys.la ../../../../src/gallium/drivers/radeon/libradeon.la  -lLLVMAsmParser -lLLVMR600CodeGen -lLLVMipo -lLLVMVectorize -lLLVMR600AsmParser -lLLVMR600Desc -lLLVMR600Info -lLLVMR600AsmPrinter -lLLVMBitWriter -lLLVMX86Disassembler -lLLVMX86AsmParser -lLLVMX86CodeGen -lLLVMSelectionDAG -lLLVMAsmPrinter -lLLVMCodeGen -lLLVMScalarOpts -lLLVMProfileData -lLLVMInstCombine -lLLVMTransformUtils -lLLVMipa -lLLVMAnalysis -lLLVMX86Desc -lLLVMMCDisassembler -lLLVMX86Info -lLLVMX86AsmPrinter -lLLVMX86Utils -lLLVMMCJIT -lLLVMTarget -lLLVMRuntimeDyld -lLLVMExecutionEngine -lLLVMObject -lLLVMMCParser -lLLVMBitReader -lLLVMMC -lLLVMCore -lLLVMSupport -lrt -ldl -ltinfo -latomic -lpthread -lz -lm 
libtool: link: g++-5  -fPIC -DPIC -shared -nostdlib /usr/lib64/gcc/x86_64-suse-linux/5/../../../../lib64/crti.o /usr/lib64/gcc/x86_64-suse-linux/5/crtbeginS.o  .libs/libomx_mesa_la-target.o  -Wl,--whole-archive ../../../../src/gallium/state_trackers/omx/.libs/libomxtracker.a ../../../../src/gallium/auxiliary/.libs/libgalliumvlwinsys.a ../../../../src/gallium/auxiliary/.libs/libgalliumvl.a ../../../../src/gallium/auxiliary/.libs/libgallium.a ../../../../src/util/.libs/libmesautil.a ../../../../src/loader/.libs/libloader.a ../../../../src/gallium/drivers/r600/.libs/libr600.a ../../../../src/gallium/winsys/radeon/drm/.libs/libradeonwinsys.a ../../../../src/gallium/drivers/radeon/.libs/libradeon.a -Wl,--no-whole-archive  -Wl,-rpath -Wl,/usr/lib64 -Wl,-rpath -Wl,/usr/lib64 -L/usr/lib64 -lnettle /usr/lib64/libomxil-bellagio.so -lX11-xcb -lX11 -lxcb-dri2 -lxcb -lexpat /usr/lib64/libdrm_radeon.so /usr/lib64/libdrm.so -lelf -lLLVMAsmParser -lLLVMR600CodeGen -lLLVMipo -lLLVMVectorize -lLLVMR600AsmParser -lLLVMR600Desc -lLLVMR600Info -lLLVMR600AsmPrinter -lLLVMBitWriter -lLLVMX86Disassembler -lLLVMX86AsmParser -lLLVMX86CodeGen -lLLVMSelectionDAG -lLLVMAsmPrinter -lLLVMCodeGen -lLLVMScalarOpts -lLLVMProfileData -lLLVMInstCombine -lLLVMTransformUtils -lLLVMipa -lLLVMAnalysis -lLLVMX86Desc -lLLVMMCDisassembler -lLLVMX86Info -lLLVMX86AsmPrinter -lLLVMX86Utils -lLLVMMCJIT -lLLVMTarget -lLLVMRuntimeDyld -lLLVMExecutionEngine -lLLVMObject -lLLVMMCParser -lLLVMBitReader -lLLVMMC -lLLVMCore -lLLVMSupport -lrt -ldl -ltinfo -latomic -lpthread -lz -L/usr/lib64/gcc/x86_64-suse-linux/5 -L/usr/lib64/gcc/x86_64-suse-linux/5/../../../../lib64 -L/lib/../lib64 -L/usr/lib/../lib64 -L/opt/intel/composer_xe_2015.0.090/compiler/lib/intel64 -L/opt/intel/composer_xe_2015.0.090/ipp/../compiler/lib/intel64 -L/opt/intel/composer_xe_2015.0.090/ipp/lib/intel64 -L/opt/intel/composer_xe_2015.0.090/mkl/lib/intel64 -L/opt/intel/composer_xe_2015.0.090/tbb/lib/intel64/gcc4.4 -L/usr/lib64/gcc/x86_64-suse-linux/5/../../../../x86_64-suse-linux/lib -L/usr/lib64/gcc/x86_64-suse-linux/5/../../.. -lstdc++ -lm -lc -lgcc_s /usr/lib64/gcc/x86_64-suse-linux/5/crtendS.o /usr/lib64/gcc/x86_64-suse-linux/5/../../../../lib64/crtn.o  -O2 -Wl,--gc-sections -Wl,--no-undefined -Wl,--version-script=../../../../src/gallium/targets/omx/omx.sym -O2   -Wl,-soname -Wl,libomx_mesa.so -o .libs/libomx_mesa.so
../../../../src/gallium/auxiliary/.libs/libgallium.a(lp_bld_misc.o):lp_bld_misc.cpp:function llvm::RTDyldMemoryManager::getSymbolAddress(std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > const&): error: undefined reference to 'llvm::RTDyldMemoryManager::getSymbolAddressInProcess(std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > const&)'
collect2: error: ld returned 1 exit status

CCing Hans Wennborg, who's managing the release.

Hans - Would it be possible to cherry-pick r229343 into the release branch?

I already tried this with no success. Maybe a mesa patch is needed instead? My lib shows getSymbolAddressInProcess is an unresolved symbol for some reason (getSymbolAddress is ok).

Hi Mark,

You might need to add RuntimeDyld to your list of dependencies a la r229351.

Cheers,
Lang.

(In reply to comment #5)
> CCing Hans Wennborg, who's managing the release.
> 
> Hans - Would it be possible to cherry-pick r229343 into the release branch?

Since we're doing an rc4 anyway, I've merged it (and r229351) in r229553.

Thanks Hans.

We are already linking agaist LLVMRuntimeDyld.so, but the problem is that the symbol is unresolvable:

# nm /usr/lib64/libLLVMRuntimeDyld.so  | grep InProc
U _ZN4llvm19RTDyldMemoryManager25getSymbolAddressInProcessERKSs

Somehow this works with gcc-4.9 but fails with gcc-5.

(In reply to comment #10)
> We are already linking agaist LLVMRuntimeDyld.so, but the problem is that
> the symbol is unresolvable:
> 
> # nm /usr/lib64/libLLVMRuntimeDyld.so  | grep InProc
> U _ZN4llvm19RTDyldMemoryManager25getSymbolAddressInProcessERKSs
> 
> Somehow this works with gcc-4.9 but fails with gcc-5.

gcc-5 uses a new C++ ABI. If you want to use LLVM libraries with gcc-5
you must build LLVM with gcc-5, too. Building LLVM with gcc-4.9 and 
then using gcc-5 to build e.g. mesa will fail. 
Another possibility is to use -D_GLIBCXX_USE_CXX11_ABI=0 with gcc-5 to 
switch back to the old ABI.
Both ABIs live in the same .so file.

ahh, you are right. Using -D_GLIBCXX_USE_CXX11_ABI=0 fixes the problem. Sorry for the noise.