When llvm-project is built with LLVM_ENABLE_ZSTD [1], clang -fuse-ld=lld -gz=zstd a.o produces zstd compressed debug sections (ch_type=ELFCOMPRESS_ZSTD). -d compileunits seems to parse DWARF and currently doesn't support decompressing zstd.
[1]:
# Build zstd with cmake
git clone https://github.com/facebook/zstd
cd zstd
cmake -GNinja -Hbuild/cmake -Bout/release -DCMAKE_BUILD_TYPE=Release -DCMAKE_INSTALL_PREFIX=/tmp/opt/zstd
make -j 8 install
# Build clang and lld. See https://llvm.org/docs/GettingStarted.html
cmake -GNinja -Sllvm -Bout/release -DCMAKE_BUILD_TYPE=Release -DLLVM_ENABLE_PROJECTS='clang;lld' -DLLVM_ENABLE_ZSTD=FORCE_ON -DCMAKE_PREFIX_PATH=/tmp/opt/zstd -DCLANG_ENABLE_ARCMT=off -DCLANG_ENABLE_STATIC_ANALYZER=off -DLLVM_TARGETS_TO_BUILD=host
ninja -C out/release llvm-objcopy clang lld
When llvm-project is built with
LLVM_ENABLE_ZSTD[1],clang -fuse-ld=lld -gz=zstd a.oproduces zstd compressed debug sections (ch_type=ELFCOMPRESS_ZSTD).-d compileunitsseems to parse DWARF and currently doesn't support decompressing zstd.[1]: