"unrecognized reloc 22" error linking libclang_rt.asan-x86_64.so with lld

[emaste]

Bugzilla Link	26878
Resolution	FIXED
Resolved on	Mar 11, 2016 12:35
Version	unspecified
OS	FreeBSD
Blocks	#23588

Extended Description

Attempting to build the asan runtime with lld as the linker on FreeBSD fails with:

[3/4] Linking CXX shared library lib/c...lib/freebsd/libclang_rt.asan-x86_64.so
FAILED: : && /usr/bin/CC -fPIC -fPIC -fvisibility-inlines-hidden -Wall -W -Wno-unused-parameter -Wwrite-strings -Wcast-qual -Wmissing-field-initializers -pedantic -Wno-long-long -Wcovered-switch-default -Wdelete-non-virtual-dtor -std=c++11 -fcolor-diagnostics -fdata-sections -Wall -std=c++11 -fuse-ld=lld -Wl,-z,origin -m64 -fPIC -fno-builtin -fno-exceptions -fomit-frame-pointer -funwind-tables -fno-stack-protector -fvisibility=hidden -fvisibility-inlines-hidden -fno-lto -O3 -gline-tables-only -Wno-gnu -Wno-variadic-macros -Wno-c99-extensions -Wno-non-virtual-dtor -fno-rtti -ftls-model=initial-exec -Wl,--version-script,/tank/emaste/src/llvm/build-lld-selfhost2/projects/compiler-rt/lib/asan/clang_rt.asan-dynamic-x86_64.vers -shared -Wl,-soname,libclang_rt.asan-x86_64.so -o lib/clang/3.9.0/lib/freebsd/libclang_rt.asan-x86_64.so projects/compiler-rt/lib/interception/CMakeFiles/RTInterception.x86_64.dir/interception_linux.cc.o [...] projects/compiler-rt/lib/ubsan/CMakeFiles/RTUbsan_cxx.x86_64.dir/ubsan_type_hash_win.cc.o -L/usr/local/lib -lc -lrt -lm -lpthread -lstdc++ -Wl,-rpath,"$ORIGIN/../lib" && :
unrecognized reloc 22

[llvmbot]

This reduces to

---

bar:
movq %fs:0, %rax
addq foo@GOTTPOFF(%rip), %rax
retq

.section	.tbss,"awT",@nobits

foo:
.long 0

being linked into a shared library.

[llvmbot]

It turns out one can just use symbol 0 as bfd ld does.

Given

    addq    foo@GOTTPOFF(%rip), %rax
    addq    bar@GOTTPOFF(%rip), %rax


    .section        .tbss,"awT",@nobits

foo:
.long 0
bar:
.long 0

it produces

Relocation section '.rela.dyn' at offset 0x1c8 contains 2 entries:
Offset Info Type Sym. Value Sym. Name + Addend
0000002002f8 000000000012 R_X86_64_TPOFF64 4
000000200300 000000000012 R_X86_64_TPOFF64 0

I will implement that.

[llvmbot]

Fixed in r26878.