Bug#995827: llvm-toolchain-13: FTBFS on armel, mipsel, mips64el: undefined references to __atomic_foo symbols

[Simon McVittie]

Source: llvm-toolchain-13
Version: 1:13.0.0-2
Severity: important
X-Debbugs-Cc: mesa at packages.debian.org, debian-mips at lists.debian.org, debian-arm at lists.debian.org

llvm-toolchain-13 has always failed to build on armel, mipsel, mips64el.
This makes mesa BD-Uninstallable on those release architectures since
its move to llvm-toolchain-13.

On armel:
> FAILED: bin/llvm-profdata 
> : && /<<PKGBUILDDIR>>/build-llvm/./bin/clang++ -fPIC -Wno-unused-command-line-argument -Wno-unknown-warning-option -fPIC -fno-semantic-interposition -fvisibility-inlines-hidden -Werror=date-time -Werror=unguarded-availability-new -Wall -Wextra -Wno-unused-parameter -Wwrite-strings -Wcast-qual -Wmissing-field-initializers -pedantic -Wno-long-long -Wc++98-compat-extra-semi -Wimplicit-fallthrough -Wcovered-switch-default -Wno-class-memaccess -Wno-noexcept-type -Wnon-virtual-dtor -Wdelete-non-virtual-dtor -Wsuggest-override -Wstring-conversion -Wmisleading-indentation -fdiagnostics-color -ffunction-sections -fdata-sections -O2 -DNDEBUG -g1 -marm -Wl,-z,relro    -Wl,-rpath-link,/<<PKGBUILDDIR>>/build-llvm/tools/clang/stage2-bins/./lib  -Wl,-O3 -Wl,--gc-sections tools/llvm-profdata/CMakeFiles/llvm-profdata.dir/llvm-profdata.cpp.o -o bin/llvm-profdata  -Wl,-rpath,"\$ORIGIN/../lib"  lib/libLLVM-13.so.1  -lpthread && :
> /usr/bin/arm-linux-gnueabi-ld: tools/llvm-profdata/CMakeFiles/llvm-profdata.dir/llvm-profdata.cpp.o: undefined reference to symbol '__atomic_fetch_add_4@@LIBATOMIC_1.0'
> /usr/bin/arm-linux-gnueabi-ld: /usr/lib/arm-linux-gnueabi/libatomic.so.1: error adding symbols: DSO missing from command line

On mips*el, the failure is in a different place, but might have the same
root cause (or not, clone this bug if necessary):
> FAILED: lib/clang/13.0.0/lib/linux/libclang_rt.scudo_standalone-mipsel.so 
> : && /usr/bin/g++-10 -fPIC -fPIC -Wno-unused-command-line-argument -Wno-unknown-warning-option -fPIC -fno-semantic-interposition -fno-shrink-wrap -fvisibility-inlines-hidden -Werror=date-time -Wall -Wextra -Wno-unused-parameter -Wwrite-strings -Wcast-qual -Wno-missing-field-initializers -pedantic -Wno-long-long -Wimplicit-fallthrough -Wno-maybe-uninitialized -Wno-class-memaccess -Wno-redundant-move -Wno-pessimizing-move -Wno-noexcept-type -Wdelete-non-virtual-dtor -Wsuggest-override -Wno-comment -Wmisleading-indentation -fdiagnostics-color -ffunction-sections -fdata-sections -Wall -std=c++14 -Wno-unused-parameter -O2 -DNDEBUG -g1  -fPIC -Wno-unused-command-line-argument -Wno-unknown-warning-option -Wl,--build-id -Wl,-z,defs -Wl,-z,nodelete   -mips32r2 -mabi=32 -D_LARGEFILE_SOURCE -D_FILE_OFFSET_BITS=64 -Wl,-z,defs,-z,now,-z,relro -ffunction-sections -fdata-sections -Wl,--gc-sections -pthread -Wl,-rpath-link,/<<PKGBUILDDIR>>/build-llvm/./lib -shared -Wl,-soname,libclang_rt.scudo_standalone-mipsel.so -o lib/clang/13.0.0/lib/linux/libclang_rt.scudo_standalone-mipsel.so projects/compiler-rt/lib/scudo/standalone/CMakeFiles/clang_rt.scudo_standalone-dynamic-mipsel.dir/checksum.cpp.o projects/compiler-rt/lib/scudo/standalone/CMakeFiles/clang_rt.scudo_standalone-dynamic-mipsel.dir/common.cpp.o projects/compiler-rt/lib/scudo/standalone/CMakeFiles/clang_rt.scudo_standalone-dynamic-mipsel.dir/crc32_hw.cpp.o projects/compiler-rt/lib/scudo/standalone/CMakeFiles/clang_rt.scudo_standalone-dynamic-mipsel.dir/flags_parser.cpp.o projects/compiler-rt/lib/scudo/standalone/CMakeFiles/clang_rt.scudo_standalone-dynamic-mipsel.dir/flags.cpp.o projects/compiler-rt/lib/scudo/standalone/CMakeFiles/clang_rt.scudo_standalone-dynamic-mipsel.dir/fuchsia.cpp.o projects/compiler-rt/lib/scudo/standalone/CMakeFiles/clang_rt.scudo_standalone-dynamic-mipsel.dir/linux.cpp.o projects/compiler-rt/lib/scudo/standalone/CMakeFiles/clang_rt.scudo_standalone-dynamic-mipsel.dir/release.cpp.o projects/compiler-rt/lib/scudo/standalone/CMakeFiles/clang_rt.scudo_standalone-dynamic-mipsel.dir/report.cpp.o projects/compiler-rt/lib/scudo/standalone/CMakeFiles/clang_rt.scudo_standalone-dynamic-mipsel.dir/string_utils.cpp.o projects/compiler-rt/lib/scudo/standalone/CMakeFiles/clang_rt.scudo_standalone-dynamic-mipsel.dir/wrappers_c.cpp.o projects/compiler-rt/lib/scudo/standalone/CMakeFiles/clang_rt.scudo_standalone-dynamic-mipsel.dir/wrappers_cpp.cpp.o  -Wl,-rpath,"\$ORIGIN/../lib" && :
> /usr/bin/ld: projects/compiler-rt/lib/scudo/standalone/CMakeFiles/clang_rt.scudo_standalone-dynamic-mipsel.dir/wrappers_c.cpp.o: in function `scudo::atomic_u64::Type scudo::atomic_load<scudo::atomic_u64>(scudo::atomic_u64 const volatile*, scudo::memory_order)':
> /<<PKGBUILDDIR>>/compiler-rt/lib/scudo/standalone/atomic_helpers.h:66: undefined reference to `__atomic_load_8'
> /usr/bin/ld: /<<PKGBUILDDIR>>/compiler-rt/lib/scudo/standalone/atomic_helpers.h:66: undefined reference to `__atomic_load_8'

    smcv