diff --git a/meta-oe/recipes-connectivity/libtorrent/libtorrent/0001-checks.m4-Keep-the-atomic-test-program-from-being-opt.patch b/meta-oe/recipes-connectivity/libtorrent/libtorrent/0001-checks.m4-Keep-the-atomic-test-program-from-being-opt.patch new file mode 100644 index 0000000000..704ec754dc --- /dev/null +++ b/meta-oe/recipes-connectivity/libtorrent/libtorrent/0001-checks.m4-Keep-the-atomic-test-program-from-being-opt.patch @@ -0,0 +1,57 @@ +From: Khem Raj +Date: Wed, 21 Oct 2026 13:00:00 -0700 +Subject: [PATCH] checks.m4: Keep the atomic test program from being optimized + away + +TORRENT_CHECK_ATOMIC decides whether -latomic is needed by linking a +program that loads from a local std::atomic. The atomic never +escapes, so with -O2 in CXXFLAGS clang folds the load to a constant and +no __atomic_* call is emitted. The check then reports that -latomic is +not required even on targets that need it for 64-bit atomics, such as +riscv32, and linking fails later: + + ld.lld: error: undefined symbol: __atomic_load_8 + +Make the atomic global and modify it with fetch_add() so the atomic +operations are emitted at any optimization level. + +Upstream-Status: Submitted [https://github.com/rakshasa/libtorrent/pull/1020] +Signed-off-by: Khem Raj +--- + scripts/checks.m4 | 13 +++++++++---- + 1 file changed, 9 insertions(+), 4 deletions(-) + +--- a/scripts/checks.m4 ++++ b/scripts/checks.m4 +@@ -99,13 +99,17 @@ + ]) + + ++# The atomic is global and modified with a read-modify-write operation, ++# otherwise the compiler can optimize the operations away and the program ++# links without libatomic even on targets that need it. + AC_DEFUN([TORRENT_CHECK_ATOMIC], [ + AC_MSG_CHECKING([whether 64-bit atomic operations require -latomic]) + AC_LANG_PUSH(C++) + + AC_LINK_IFELSE([AC_LANG_PROGRAM([[#include +- #include ]], +- [[std::atomic x(0); ++ #include ++ std::atomic x(0);]], ++ [[x.fetch_add(1); + return x.load();]])], + [ + AC_MSG_RESULT([no]) +@@ -116,8 +120,9 @@ + LIBS="$LIBS -latomic" + + AC_LINK_IFELSE([AC_LANG_PROGRAM([[#include +- #include ]], +- [[std::atomic x(0); ++ #include ++ std::atomic x(0);]], ++ [[x.fetch_add(1); + return x.load();]])], + [ + AC_MSG_RESULT([yes]) diff --git a/meta-oe/recipes-connectivity/libtorrent/libtorrent_0.16.25.bb b/meta-oe/recipes-connectivity/libtorrent/libtorrent_0.16.25.bb index 5b7133e645..a60d66730e 100644 --- a/meta-oe/recipes-connectivity/libtorrent/libtorrent_0.16.25.bb +++ b/meta-oe/recipes-connectivity/libtorrent/libtorrent_0.16.25.bb @@ -6,7 +6,9 @@ LIC_FILES_CHKSUM = "file://COPYING;md5=393a5ca445f6965873eca0259a17f833" DEPENDS = "zlib curl libsigc++-2.0 openssl cppunit" -SRC_URI = "git://github.com/rakshasa/libtorrent;branch=master;protocol=https;tag=v${PV}" +SRC_URI = "git://github.com/rakshasa/libtorrent;branch=master;protocol=https;tag=v${PV} \ + file://0001-checks.m4-Keep-the-atomic-test-program-from-being-opt.patch \ + " SRCREV = "6ad3fecf3e7e7aa86855445587b532a91256f344" UPSTREAM_CHECK_GITTAGREGEX = "v(?P\d+(\.\d+)+)"