"relocation R_X86_64_PC32 against undefined symbol ..."

[zmodem]

Bugzilla Link	8713
Resolution	FIXED
Resolved on	Dec 09, 2010 21:00
Version	trunk
OS	Linux
CC	@asl,@nico,@rjmccall

Extended Description

Trying to compile and link the following into a shared library fails:

#include

extern std::ostream& get_ostream();

void f() {
get_ostream() << "foo";
}

$ clang++ -fno-exceptions -fvisibility=hidden -fPIC -fno-rtti -fno-threadsafe-statics -fvisibility-inlines-hidden -c a.cc -o fail.o
$ clang++ -shared -o fail.so fail.o
/usr/bin/ld: fail.o: relocation R_X86_64_PC32 against undefined symbol `_ZStlsISt11char_traitsIcEERSt13basic_ostreamIcT_ES5_PKc@@GLIBCXX_3.4' can not be used when making a shared object; recompile with -fPIC
/usr/bin/ld: final link failed: Bad value
clang: error: linker command failed with exit code 1 (use -v to see invocation)

If g++ is used in the first step, the link step succeeds.

$ clang++ -v
clang version 2.9 (trunk 120563)
Target: x86_64-unknown-linux-gnu
Thread model: posix

gcc version 4.4.3 (Ubuntu 4.4.3-4ubuntu5)

[lattner]

Does this work with -no-integrated-as?

[zmodem]

Does this work with -no-integrated-as?

No. Doesn't seem to be related to integrated as.

[nico]

Can you bisect to find when this regressed?

[zmodem]

Can you bisect to find when this regressed?

Tracked it down to r117781.

Looking at the LLVM IR, it looks like @​_ZStlsISt11char_traitsIcEERSt13basic_ostreamIcT_ES5_PKc comes out declared hidden after this revision.

[rjmccall]

I think I'm going to need preprocessed source, sorry; I'm not seeing this on ToT on my machine, so either there's been a significant change to visibility calculations (I don't think so! dgregor's changes didn't significantly affect semantics) or our headers are significantly different.

[zmodem]

Pre-processed source
Thanks for looking at this! Attaching pre-processed source.

[rjmccall]

Reduced test case:

namespace std attribute ((visibility ("default"))) {
template struct char_traits {};
template class basic_ostream {};
template inline void foo() {}
extern template void foo<std::basic_ostream<std::char_traits > >();
}

void f() {
std::foo<std::basic_ostream<std::char_traits > >();
}

Looking into it.

[rjmccall]

Fixed in r121459.