build: Fix check whether -latomic needed

[hebasto]

Clang >=15 still might need linking against libatomic.

We use std::atomic<std::chrono::seconds>::compare_exchange_strong in net_processing.cpp.

Addresses the #29165 (comment).

[DrahtBot]

The following sections might be updated with supplementary metadata relevant to reviewers and maintainers.

Code Coverage

For detailed information about the code coverage, see the test coverage report.

Reviews

See the guideline for information on the review process.

Type	Reviewers
ACK	maflcko, fanquake

If your review is incorrectly listed, please react with 👎 to this comment and the bot will ignore it on the next update.

[maflcko]

Testing on a fresh install of Ubuntu 24.04 Noble: export DEBIAN_FRONTEND=noninteractive && apt update && apt install curl wget htop git vim ccache -y && git clone https://github.com/bitcoin/bitcoin.git --depth=1 && cd bitcoin && git fetch origin --depth=1 f8ca1357c8205ceff732dcfb0d2bad79b40b611b && git checkout f8ca1357c8205ceff732dcfb0d2bad79b40b611b && apt install build-essential libtool autotools-dev automake pkg-config bsdmainutils python3 make automake cmake curl clang-17 llvm-17 g++-multilib libtool binutils-gold bsdmainutils pkg-config python3 patch bison -y && ( cd depends && make DEBUG=1 HOST=i686-pc-linux-gnu NO_QT=1 NO_WALLET=1 NO_ZMQ=1 NO_UPNP=1 NO_NATPMP=1 -j $(nproc) ) && ./autogen.sh && CONFIG_SITE="$PWD/depends/i686-pc-linux-gnu/share/config.site" ./configure CC='clang-17 -m32' CXX='clang++-17 -m32' --enable-fuzz --with-sanitizers=fuzzer && make -j $(nproc)

On master:

  CXXLD    test/fuzz/fuzz
/usr/bin/ld: libbitcoin_node.a(libbitcoin_node_a-net_processing.o): in function `(anonymous namespace)::PeerManagerImpl::BlockConnected(ChainstateRole, std::shared_ptr<CBlock const> const&, CBlockIndex const*)':
net_processing.cpp:(.text._ZN12_GLOBAL__N_115PeerManagerImpl14BlockConnectedE14ChainstateRoleRKSt10shared_ptrIK6CBlockEPK11CBlockIndex[_ZN12_GLOBAL__N_115PeerManagerImpl14BlockConnectedE14ChainstateRoleRKSt10shared_ptrIK6CBlockEPK11CBlockIndex]+0x1ef): undefined reference to `__atomic_compare_exchange'
/usr/bin/ld: libbitcoin_node.a(libbitcoin_node_a-net_processing.o): in function `(anonymous namespace)::PeerManagerImpl::SendMessages(CNode*)':
net_processing.cpp:(.text._ZN12_GLOBAL__N_115PeerManagerImpl12SendMessagesEP5CNode[_ZN12_GLOBAL__N_115PeerManagerImpl12SendMessagesEP5CNode]+0x6755): undefined reference to `__atomic_compare_exchange'
clang++-17: error: linker command failed with exit code 1 (use -v to see invocation)

This pull:

(all good)

[maflcko]

lgtm ACK f8ca135

[DrahtBot]

Guix builds (on x86_64)

File	commit 737e588 (master)	commit 5ce5262 (master and this pull)
SHA256SUMS.part	a05449ccd1eedf9d...	fe8d60bbcf9ad8cd...
*-aarch64-linux-gnu-debug.tar.gz	566e2e720e510496...	a685f4cdcb3aee69...
*-aarch64-linux-gnu.tar.gz	ac229ee212444de0...	969f2526d0697eda...
*-arm-linux-gnueabihf-debug.tar.gz	102d6be068c3d6db...	89dc848df155e070...
*-arm-linux-gnueabihf.tar.gz	d9dbd398b7ac417a...	3b842464ec317e40...
*-arm64-apple-darwin-unsigned.tar.gz	0e35063d34b37755...	adcf46c22e631365...
*-arm64-apple-darwin-unsigned.zip	75cc4be9a95235df...	19ed760a0e0d3d5d...
*-arm64-apple-darwin.tar.gz	661ebadfcd81951b...	84ab633d7f83e5d0...
*-powerpc64-linux-gnu-debug.tar.gz	4e30d97f09a8ad90...	fc13019f93b13e8b...
*-powerpc64-linux-gnu.tar.gz	2fa917b453e3b98e...	51a5f86e8669d447...
*-powerpc64le-linux-gnu-debug.tar.gz	57964282dce22f4d...	aab298fdecb3a42c...
*-powerpc64le-linux-gnu.tar.gz	ceb6f7cf6acdff9f...	acf3ac47cfcd289f...
*-riscv64-linux-gnu-debug.tar.gz	436eb35b0015a18e...	3fbd1e7ee15b6d27...
*-riscv64-linux-gnu.tar.gz	d3022d5be39d5c59...	25637002066d8a8c...
*-x86_64-apple-darwin-unsigned.tar.gz	c5a222621368a649...	37e2a7aed74cb942...
*-x86_64-apple-darwin-unsigned.zip	3148c2407851a49f...	bcb046a76fdd21d9...
*-x86_64-apple-darwin.tar.gz	0bd0c25b23aa186d...	d25006a37829577a...
*-x86_64-linux-gnu-debug.tar.gz	bba534832b7dd68f...	cfa215a4e4fe9891...
*-x86_64-linux-gnu.tar.gz	e8b23d8149cb6e00...	6514d464b471868f...
*.tar.gz	3f2dc263df892f77...	12b1625180444fb1...
guix_build.log	5b6f96ccdf1553af...	b7b63b58106165ed...
guix_build.log.diff		55b083f7b7bcb07a...

[fanquake]

ACK f8ca135