openssl-3.0.0: -latomic missing from linux-x86-clang

[DirtYiCE]

Trying to build openssl-3.0.0 with ./Configure linux-x86-clang && make fails with undefined references:

${LDCMD:-clang} -pthread -m32 -Wa,--noexecstack -Qunused-arguments -Wall -O3 -fomit-frame-pointer -L.   \
        -o apps/openssl \
        apps/lib/openssl-bin-cmp_mock_srv.o \
        apps/openssl-bin-asn1parse.o apps/openssl-bin-ca.o \
        apps/openssl-bin-ciphers.o apps/openssl-bin-cmp.o \
        apps/openssl-bin-cms.o apps/openssl-bin-crl.o \
        apps/openssl-bin-crl2pkcs7.o apps/openssl-bin-dgst.o \
        apps/openssl-bin-dhparam.o apps/openssl-bin-dsa.o \
        apps/openssl-bin-dsaparam.o apps/openssl-bin-ec.o \
        apps/openssl-bin-ecparam.o apps/openssl-bin-enc.o \
        apps/openssl-bin-engine.o apps/openssl-bin-errstr.o \
        apps/openssl-bin-fipsinstall.o apps/openssl-bin-gendsa.o \
        apps/openssl-bin-genpkey.o apps/openssl-bin-genrsa.o \
        apps/openssl-bin-info.o apps/openssl-bin-kdf.o \
        apps/openssl-bin-list.o apps/openssl-bin-mac.o \
        apps/openssl-bin-nseq.o apps/openssl-bin-ocsp.o \
        apps/openssl-bin-openssl.o apps/openssl-bin-passwd.o \
        apps/openssl-bin-pkcs12.o apps/openssl-bin-pkcs7.o \
        apps/openssl-bin-pkcs8.o apps/openssl-bin-pkey.o \
        apps/openssl-bin-pkeyparam.o apps/openssl-bin-pkeyutl.o \
        apps/openssl-bin-prime.o apps/openssl-bin-progs.o \
        apps/openssl-bin-rand.o apps/openssl-bin-rehash.o \
        apps/openssl-bin-req.o apps/openssl-bin-rsa.o \
        apps/openssl-bin-rsautl.o apps/openssl-bin-s_client.o \
        apps/openssl-bin-s_server.o apps/openssl-bin-s_time.o \
        apps/openssl-bin-sess_id.o apps/openssl-bin-smime.o \
        apps/openssl-bin-speed.o apps/openssl-bin-spkac.o \
        apps/openssl-bin-srp.o apps/openssl-bin-storeutl.o \
        apps/openssl-bin-ts.o apps/openssl-bin-verify.o \
        apps/openssl-bin-version.o apps/openssl-bin-x509.o \
        apps/libapps.a -lssl -lcrypto -ldl -pthread 
/usr/bin/x86_64-pc-linux-gnu-ld: ./libcrypto.so: undefined reference to `__atomic_is_lock_free'
/usr/bin/x86_64-pc-linux-gnu-ld: ./libcrypto.so: undefined reference to `__atomic_fetch_or_8'
/usr/bin/x86_64-pc-linux-gnu-ld: ./libcrypto.so: undefined reference to `__atomic_load'
clang-12: error: linker command failed with exit code 1 (use -v to see invocation)

Interestingly, using ./Configure linux-x86, which uses gcc instead of clang works correctly. So does ./Configure linux-x86-clang -latomic, it looks like clang needs libatomic while gcc doesn't. I see that there were changes with the handling of -latomic, #15086, but partially reverted in #15640, the latter suggesting simply documenting the incomplete handling of this library, so I'm not sure what would be the correct action to fix this.

OS: Gentoo Linux
Clang: 12.0.0
Gcc: 9.3.0
perl configdata.pm --dump

[t8m]

The question is whether if we add it to the linux-x86-clang target it won't break on later clang versions. 12.0.0 is quite old. I can do a tentative PR.

[t8m]

Fix in #16578

[paulidale]

The compiler zoo is on merge not PR.

[xtkoba]

FWIW, Clang 13.0.0-rc2 (Gentoo) still emits atomic libcalls for i686-linux:

$ cat openssl-atomic-test.c

#include <stdint.h>

uint64_t foo(uint64_t *val, uint64_t op)
{
    return __atomic_or_fetch(val, op, __ATOMIC_ACQ_REL);
}

$ clang -m32 openssl-atomic-test.c -S -emit-llvm -o - 2>/dev/null | grep '@__atomic_'
  %11 = call i64 @__atomic_fetch_or_8(i8* %9, i64 %10, i32 4)
declare dso_local i64 @__atomic_fetch_or_8(i8*, i64, i32) #1

[t8m]

The compiler zoo is on merge not PR.

Good point, I can temporarily enable it.

[ngg]

Clang 12.0.0 was released 5 months ago, it's not that old. (The newest version is 12.0.1)

…

On Fri, Sep 10, 2021, 10:44 Tomáš Mráz ***@***.***> wrote: The question is whether if we add it to the linux-x86-clang target it won't break on later clang versions. 12.0.0 is quite old. I can do a tentative PR. — You are receiving this because you are subscribed to this thread. Reply to this email directly, view it on GitHub <#16572 (comment)>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/AAEGN7TINNIKZ6DVI6DCRXTUBHANTANCNFSM5DXNLLSQ> .