[libcxx-commits] [PATCH] D95875: [SystemZ][ZOS] Prefer -nostdlib++ as opposed to -nodefaultlibs when building c++ libraries

[Harald van Dijk via Phabricator via libcxx-commits]

hvdijk added a comment.

In D95875#2565670 <https://reviews.llvm.org/D95875#2565670>, @ldionne wrote:

> I think this is good for libunwind too

It's not, depending on how clang is configured this can cause the libunwind build to fail because clang now tries to link libunwind against itself. `-nodefaultlibs` prevents that, `-nostdlib++` does not.

  /usr/bin/clang  -m64 -fPIC -O2 --target=x86_64-unknown-linux-gnu -DNDEBUG --target=x86_64-unknown-linux-gnu -rtlib=compiler-rt -nostdlib++ -Wl,-O1 -Wl,--as-needed -s -shared -Wl,-soname,libunwind.so.1 -o ../lib/x86_64-linux-gnu/libunwind.so.1.0 CMakeFiles/unwind_shared.dir/libunwind.cpp.o CMakeFiles/unwind_shared.dir/Unwind-EHABI.cpp.o CMakeFiles/unwind_shared.dir/Unwind-seh.cpp.o CMakeFiles/unwind_shared.dir/UnwindLevel1.c.o CMakeFiles/unwind_shared.dir/UnwindLevel1-gcc-ext.c.o CMakeFiles/unwind_shared.dir/Unwind-sjlj.c.o CMakeFiles/unwind_shared.dir/UnwindRegistersRestore.S.o CMakeFiles/unwind_shared.dir/UnwindRegistersSave.S.o  -lc /usr/lib/clang/13.0.0/lib/linux/libclang_rt.builtins-x86_64.a -ldl -lpthread 
  ld.lld: error: unable to find library -l:libunwind.so
  ld.lld: error: unable to find library -l:libunwind.so
  clang: error: linker command failed with exit code 1 (use -v to see invocation)

Would there be any objections to reverting this change for libunwind, or do you prefer to fix this some other way?


Repository:
  rG LLVM Github Monorepo

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  https://reviews.llvm.org/D95875/new/

https://reviews.llvm.org/D95875